Air-cooled Compact Power System

Abstract

An apparatus comprising a busbar, a heat pipe, and a device, the device having a metal structure, a metal element, and a transistor. The metal structure may have flat, opposing first and second surfaces. The metal element may have flat, opposing first and second surfaces. The transistor may have a first terminal and a second terminal, and current is transmitted between the first and second terminals when the transistor is operating. The first and second terminals may have substantially flat, opposing first and second surfaces, respectively. The first and second surfaces of the first and second terminals may be sintered to the first and second surfaces of the metal structure and the metal element, respectively. The heat pipe is thermally connected to the busbar. The second surface of the metal structure is electrically and thermally connected to the busbar.

Description

[Background technology]

[0001] Power systems use power semiconductors, including power transistors and power diodes. A power converter is an example of a power system. A power converter converts power. An "inverter" is a type of power converter. An inverter converts direct current (DC) power to alternating current (AC) power. A "rectifier" is another type of power converter. A rectifier converts AC power to DC power. A DC-DC converter (e.g., a buck, boost, or buck-boost converter) converts DC power at one voltage level to DC power at another voltage level. An AC-AC converter (e.g., a variable frequency drive, matrix converter, etc.) converts AC power in one form to AC power in another form. Some AC-AC converters include a DC link electrically connected between the rectifier and the inverter, converting AC power at one frequency to AC power at another frequency.

[0002] The present technology may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. [Brief explanation of the drawings]

[0003] [Figure 1A] FIG. 2 illustrates relevant components of an example three-phase inverter. [Figure 1B] FIG. 4 is a timing diagram illustrating an example of a gate control signal. [Figure 1C] FIG. 1 illustrates relevant components of an example three-phase rectifier. [Figure 2A-1] FIG. 1 illustrates a top view of an example packaged switch. [Figure 2A-2] FIG. 1 illustrates a bottom view of an example packaged switch. [Figure 2A-3] FIG. 1 is a side view of an example packaged switch. [Figure 2B-1] FIG. 1 illustrates a top view of an example packaged switch. [Figure 2B-2]FIG. 1 illustrates a bottom view of an example packaged switch. [Figure 2B-3] FIG. 1 is a side view of an example packaged switch. [Figure 2C-1] FIG. 1 illustrates a top view of an example packaged switch. [Figure 2C-2] FIG. 1 illustrates a bottom view of an example packaged switch. [Figure 2C-3] FIG. 1 is a side view of an example packaged switch. [Figure 2D-1] FIG. 1 illustrates a top view of an example packaged switch. [Figure 2D-2] FIG. 1 illustrates a bottom view of an example packaged switch. [Figure 2D-3] FIG. 1 is a side view of an example packaged switch. [Figure 2E-1] FIG. 1 is a top view of an example packaged diode. [Figure 2E-2] FIG. 1 is a bottom view of an example packaged diode. [Figure 2E-3] FIG. 1 is a side view of an example of a packaged diode. [Figure 2F] FIG. 1 is a top view illustrating a portion of an example of a transistor. [Figure 2G] FIG. 1 is a side view illustrating a portion of an example of a transistor. [Figure 2H] FIG. 2 is a side view showing a portion of an example of a laminate sheet. [Figure 3A] FIG. 1 illustrates an example of a packaged switch. [Figure 3B] FIG. 1 illustrates an example of a packaged switch. [Figure 3C] FIG. 1 illustrates an example of a packaged switch. [Figure 3D] FIG. 1 illustrates an example of a packaged switch. [Figure 3E] FIG. 1 illustrates an example of a packaged switch. [Figure 3F] FIG. 1 illustrates an example of a packaged switch. [Figure 3G]FIG. 1 illustrates an example of a packaged switch. [Figure 3H] FIG. 1 illustrates an example of a packaged switch. [Figure 3I] FIG. 1 illustrates an example of a packaged switch. [Figure 3J] FIG. 1 illustrates an example of a packaged switch. [Figure 3K] FIG. 1 illustrates an example of a packaged switch. [Figure 3L] FIG. 1 illustrates an example of a packaged switch. [Figure 3M] FIG. 1 illustrates an example of a packaged diode. [Figure 3N] FIG. 1 illustrates an example of a packaged diode. [Figure 3O] FIG. 1 illustrates an example of a packaged switch. [Figure 3P] FIG. 1 illustrates an example of a packaged switch. [Figure 4A-1] 1A and 1B are top and side views of an example die substrate. [Figure 4A-2] 1A and 1B are top and side views of an example die substrate with an example transistor. [Figure 4A-3] 1A and 1B are top and side views of an example die substrate with an example transistor and a pedestal. [Figure 4A-4] 1A and 1B are top and side views of an example die clip. [Figure 4A-5] 1A and 1B are top and side views of an example switch module. [Figure 4A-6] 1A and 1B are top and side views of an example die substrate with an example transistor and a pedestal. [Figure 4A-7] 1A and 1B are top and side views of an example switch module. [Figure 4A-8] 1A and 1B are top and side views of an example die substrate with an example transistor and a pedestal. [Figure 4A-9] 1A and 1B are top and side views of an example switch module. [Figure 4B-1] 1A and 1B are top and side views of an example die substrate with an example transistor. [Figure 4B-2] 1A and 1B are top and side views of an example die substrate with an example transistor and a pedestal. [Figure 4B-3] 1A and 1B are top and side views of an example switch module. [Figure 4B-4] 1A and 1B are top and side views of an example die substrate with an example transistor and a pedestal. [Figure 4B-5] 1A and 1B are top and side views of an example switch module. [Figure 4C-1] 1A and 1B are top and side views of an example die clip with an example transistor. [Figure 4C-2] 1A and 1B are top and side views of an example switch module. [Figure 4D-1] 1A and 1B are top and side views of an example die clip with an example transistor and pedestal. [Figure 4D-2] 1A and 1B are top and side views of an example paddle. [Figure 4D-3] 1A and 1B are top and side views of an example switch module. [Figure 4E-1] 1A and 1B are top and side views of an example die substrate with an example transistor. [Figure 4E-2] 1A and 1B are top and side views of an example die clip with an example transistor and pedestal. [Figure 4E-3] 1A and 1B are top and side views of an example switch module. [Figure 4F-1] 1A and 1B are top and side views of an example die substrate with an example transistor. [Figure 4F-2] 1A and 1B are top and side views of an example die substrate with an example transistor and a pedestal. [Figure 4F-3] 1A and 1B are top and side views of an example switch module. [Figure 4G-1] 1A and 1B are a top view and a side view of an example of a transistor. [Figure 4G-2]1A and 1B are top and side views of an example transistor with an example signal frame. [Figure 4G-3] 1A and 1B are top and side views of an example transistor with an example signal frame and pedestal. [Figure 4G-4] FIG. 4G-3 is a side view of the structure shown in FIG. [Figure 4G-5] FIG. 4G-3 is a cross-sectional view of the structure shown in FIG. [Figure 4G-6] 1A and 1B are top and side views of an example die substrate with an example transistor. [Figure 4G-7] 1A and 1B are top and side views of an example switch module. [Figure 4G-8] FIG. 1 is a top view of an example transistor with an example signal frame and pedestal. [Figure 4G-9] FIG. 1 is a top view of an example die substrate with an example transistor. [Figure 4G-10] FIG. 1 is a side view of an example die substrate with an example transistor. [Figure 4G-11] FIG. 2 is a side view of an example of a switch module. [Figure 4G-12] FIG. 2 is a top view of an example of a switch module. [Figure 4H] 1A and 1B are top and side views of an example of a diode module. [Figure 5A-1] FIG. 2 is a bottom view of an example of a converter. [Figure 5A-2] FIG. 2 is a side view of an example of a converter. [Figure 5A-3] FIG. 1 is a diagram illustrating an example of a heat pipe. [Figure 5A-4] FIG. 2 is a bottom view of an example of a converter. [Figure 5A-5] FIG. 2 is a side view of an example of a converter. [Figure 5A-6] FIG. 2 is a side view of an example of a converter. [Figure 5A-7] FIG. 4 is a diagram illustrating an example of a heat fin. [Figure 5A-8] FIG. 2 is a bottom view of an example of a converter. [Figure 5A-9] FIG. 2 is a side view of an example of a converter. [Figure 5A-10] FIG. 4 is a diagram illustrating an example of a heat fin. [Figure 5B-1] FIG. 2 is a bottom view of an example of a converter. [Figure 5B-2] FIG. 2 is a side view of an example of a converter. [Figure 5C-1] FIG. 2 is a bottom view of an example of a converter. [Figure 5C-2] FIG. 2 is a side view of an example of a converter. [Figure 5C-3] FIG. 2 is a side view of an example of a converter. [Figure 5D-1] FIG. 2 is a bottom view of an example of a converter. [Figure 5D-2] FIG. 2 is a side view of an example of a converter. [Figure 5D-3] FIG. 2 is a side view of an example of a converter. [Figure 5E] FIG. 2 is a bottom view of an example of a converter. [Figure 5F-1] FIG. 1 is an end view of an example converter. [Figure 5F-2] FIG. 2 is a front view of an example converter. [Figure 5F-3] FIG. 2 is a rear view of an example of a converter. [Figure 5G] FIG. 2 is a bottom view of an example of an integrated converter. [Figure 5H] FIG. 2 is a bottom view of an example of an integrated converter. [Figure 5I-1] FIG. 1 is a bottom view of an example solid-state circuit breaker. [Figure 5I-2] 2 is a side view of an example of a solid-state circuit breaker. [Figure 5J-1] FIG. 2 is a front view of an example converter. [Figure 5J-2] FIG. 2 is a side view of an example of a converter. [Figure 5J-3] FIG. 1 is a side view of an example of an air-cooled bus bar and coupling. [Figure 5J-4] FIG. 1 is an end view of an example air-cooled busbar and coupling. [Figure 5J-5] FIG. 2 is a side view of an example of an air-cooled bus bar. [Figure 5J-6]FIG. 1 is an end view of an example air-cooled bus bar. [Figure 5K] FIG. 2 is a bottom view of an example of an integrated converter. DETAILED DESCRIPTION OF THE INVENTION

[0004] The use of the same reference numeral in different figures indicates the same item. In the text, a reference numeral without a letter and / or number following it may refer to the element having that reference numeral. For example, the reference numeral "204" may refer to 204, 204L, 204H, 204L-1, etc., and the reference numeral "204L" may refer to 204L, 204L-1, etc.

[0005] Power systems include power converters, solid-state circuit breakers (SSCBs), etc. Power converters include inverters, rectifiers, DC / DC converters, variable frequency drives, etc. SSCBs are devices that can switch an electrical circuit on or off. For example, SSCBs may be used in the electrical path between a voltage source, such as a battery, and a power converter, such as an inverter. While this disclosure is primarily described with respect to inverters, rectifiers, and SSCBs, this disclosure is applicable to other power systems.

[0006] The inverters and rectifiers of the present disclosure may be bidirectional. A bidirectional inverter can convert DC power to AC power during forward operation and AC power to DC power during reverse operation. A bidirectional rectifier can convert AC power to DC power during forward operation and DC power to AC power during reverse operation.

[0007] Inverters and rectifiers may vary in design. For example, inverters and rectifiers may have one or more phases. Each phase may include one or more legs or half-bridges. Each leg or half-bridge may include a "high-side switch" electrically connected to a "low-side switch." When a switch is turned on (i.e., activated), it conducts current between its current terminals.

[0008] FIG. 1A shows relevant components of a three-phase inverter 100 for converting DC power from a battery into three-phase AC power for an electric motor. Each phase includes a high-side switch connected to a low-side switch. Each high-side switch includes a high-side transistor THx connected in parallel with a high-side diode DHx, and each low-side switch includes a low-side transistor TLx connected in parallel with a low-side diode DLx. In FIG. 1A, each transistor T is an insulated gate bipolar transistor (IGBT).

[0009] The high-side transistors TH1 to TH3 are connected in series to the low-side transistors TL1 to TL3 via nodes N1 to N3, respectively, which are connected to the terminals of the inductive elements Wa to Wc. For illustrative purposes, the inductive elements Wa to Wc are configured as stator windings of a synchronous or asynchronous motor of an electric vehicle (EV).

[0010] The collector terminals of TH1 to TH3 and the cathode terminals of DH1 to DH3 are connected to each other and to the V+ input terminal. Meanwhile, the emitter terminals of TL1 to TL3 and the anode terminals of diodes DL1 to DL3 are connected to each other and to the V- input terminal. A DC voltage Vdc is supplied between the V+ input terminal and the V- input terminal by a battery or other DC power source.

[0011] High-side transistors TH1-TH3 and low-side transistors TL1-TL3 are controlled by microcontroller 110 via gate drivers H101-H103 and L101-L103, respectively. A driver is a device that receives low-power input signals from a device (e.g., a microcontroller) and generates corresponding high-power output signals required to operate the transistors.

[0012] Control of transistor T is relatively simple. High-side gate drivers H101-H103 and low-side gate drivers L101-L103 receive driver control signals (e.g., pulse-width modulation signals PWM-H1-PWM-H3 and PWM-L1-PWM-L3) from microcontroller 110. When the high-side gate drivers H101-H103 receive the PWM-H1-PWM-H3 signals, they apply high-power gate control signals VgH1-VgH3 to operate high-side transistors TH1-TH3, respectively. When the low-side gate drivers L101-L103 receive the PWM-L1-PWM-L3 signals, they apply high-power gate control signals VgL1-VgL3 to operate low-side transistors TL1-TL3, respectively. Each of the transistors TH1-TH3 and TL1-TL3 supplies or draws current to or from the stator winding W to which it is connected when in operation.

[0013] By operating transistors TH1-TH3 and TL1-TL3 in a coordinated manner, the direction of current flow in the stator windings can be controlled, allowing current to flow in or out of the windings. FIG. 1B shows an example timing diagram of gate control signals VgH1-VgH3 and VgL1-VgL3. This timing diagram is provided solely to facilitate a basic understanding of inverter control. In practice, more complex timing patterns are typically used to control the inverter.

[0014] Microcontroller 110 controls high-side transistors TH1-TH3 and low-side transistors TL1-TL3 via PWM-H1-PWM-H3 and PWM-L1-PWM-L3 signals, respectively. Microcontrollers such as microcontroller 110 and other similar data processing devices may include a central processing unit (CPU), memory for storing CPU-executable instructions, and peripherals such as timers and input / output (I / O) ports. Microcontroller 110 generates the PWM-H1-PWM-H3 and PWM-L1-PWM-L3 signals based on the CPU-executable instructions stored in the memory. Gate drivers H101-H103 generate VgH1-VgH3 signals based on the PWM-H1-PWM-H3 signals, and gate drivers L101-L103 generate VgL1-VgL3 signals based on the PWM-L1-PWM-L3 signals. The microcontroller 110 can adjust the duty cycle and / or period of the pulse width modulated (PWM) signal according to instructions stored in memory.

[0015] FIG. 1C illustrates the relevant components of a three-phase rectifier 150 that can be used to convert three-phase AC power from a power grid to DC power for charging an EV battery. The inverter 100 and the rectifier 150 are similar. Like the inverter 100, each phase of the rectifier 150 includes a high-side switch connected to a low-side switch. Each high-side switch includes a transistor THx connected in parallel with a diode DHx, and each low-side switch includes a transistor TLx connected in parallel with a diode DLx. High-side transistors TH1-TH3 are connected in series with low-side transistors TL1-TL3, respectively, via nodes N1-N3, which are connected to respective terminals of inductive elements La-Lc. For illustrative purposes, the inductive elements La-Lc are configured as inductors of an LCL filter 162, which is connected to a three-phase AC power source 164.

[0016] The collector terminals of TH1 to TH3 and the cathode terminals of DH1 to DH3 are connected to each other and also to the V+ output terminal, while the emitter terminals of TL1 to TL3 and the anode terminals of diodes DL1 to DL3 are connected to each other and also to the V- output terminal.

[0017] The high-side transistors TH1-TH3 and the low-side transistors TL1-TL3 are controlled by a rectifier controller 160 via gate drivers H101-H103 and L101-L103, respectively. Through coordinated operation of the high-side and low-side IGBTs, the rectifier 150 supplies a rectified DC voltage Vrdc to output terminals V+ and V−, which may be connected to another device, such as an isolated DC / DC converter, that can employ one or more aspects of the present disclosure. Although not shown, a filter may be connected between the output terminals V+ and V− to smooth Vrdc before supplying it to another device, such as an isolated DC / DC converter.

[0018] While inverter 100 and rectifier 150 are similar, there is at least one difference. Rectifier 150 includes a controller 160, which may include a phase-locked loop (PLL) or other components for synchronizing control of high-side transistors TH1-TH3 and low-side transistors TL1-TL3 to the frequency (e.g., 60 Hz) of three-phase AC input power provided by power supply 164. Controller 160 may also include a CPU and memory for storing CPU-executable instructions, although these CPU-executable instructions may differ from the CPU-executable instructions stored in the memory of microcontroller 110 of inverter 100. Like microcontroller 110, controller 160 generates PWM-H1-H3 and PWM-L1-L3 signals. The gate drivers H101 to H103 generate the VgH1 to VgH3 signals based on the PWM-H1 to PWM-H3 signals, and the gate drivers L101 to L103 generate the VgL1 to VgL3 signals based on the PWM-L1 to PWM-L3 signals. The controller 160 can adjust the duty cycle and / or period of the PWM signals.

[0019] EVs, DC fast chargers, industrial machinery (e.g., industrial pumps, fans, compressors, etc.), and electric vertical take-off and landing (eVTOL) vehicles use large and heavy power converters. There is a demand for smaller, lighter power converters with higher power density (i.e., power / volume). For example, the October 2017 "Electrical and Electronics Engineering Team (EETT) Roadmap," published in part by the U.S. Department of Energy, sets a 2025 power density target of 100 kW / L for EV inverters. The 2017 EETT Roadmap states, "Achieving the 2025 EETT R&D goals requires a power density increase of more than 800% compared to the 2015 EETT R&D technology goals and more than 450% compared to current commercial technologies."

[0020] A "power module" is disclosed. The power module may comprise a "switch module" and a "diode module." A "packaged power module" is disclosed. The packaged power module may comprise a packaged switch module and a packaged diode module. Power converters and SSBCs are disclosed, which may use packaged switches and / or packaged diodes.

[0021] The switch module may include a "power stack." The power stack includes a "switch" that is electrically and thermally connected (e.g., sintered, soldered, etc.) to and sandwiched between a "die substrate" and a "die clip." The switch may be bidirectional or capable of controlling forward and reverse current. The switch may include one, two, or more power transistors (hereinafter "transistors"). The transistors in a switch may be connected in parallel, anti-parallel, or back-to-back. The switch may also include one or more power diodes (hereinafter "diodes") connected in parallel or anti-parallel with one or more transistors. Depending on the configuration, the switch may carry 10, 20, 50, 100, 200, 400 amperes (A), or more of current during operation or upon power input. The switch module may include one or more additional components, such as a transistor control terminal driver (hereinafter "driver," e.g., a gate driver or base driver), resistors, capacitors, current sensors, temperature sensors, voltage sensors, voltage regulators, etc.

[0022] The diode module may include a power stack. The power stack includes one or more diodes that are electrically and thermally connected (e.g., sintered, soldered, etc.) and sandwiched between the die substrate and the die clip. Multiple diodes may be connected in parallel. The diode module may also include one or more additional components, such as resistors, capacitors, current sensors, temperature sensors, voltage sensors, etc.

[0023] The die substrate and die clip are electrically and thermally conductive elements. The die substrate and die clip may have die substrate terminals and die clip terminals, respectively. Current may be transmitted along a substantially straight path between the die substrate terminal containing the active switch or diode and the die clip terminal. Heat generated in the switch or diode and current conducted by the switch or diode may simultaneously be transmitted through the die substrate terminal and / or die clip terminal. The die substrate terminal and die clip terminal may be thermally and electrically connected to a bus bar, a heat sink, or a bus bar that also functions as a heat sink.

[0024] A packaged switch module (hereinafter also referred to as a packaged switch) may include one or more switch modules. Packaged switch modules may be used in converters, SSCBs, etc. A packaged switch module having only one switch module is called a "packaged switch." A packaged switch module having two switch modules is called a "packaged half-bridge." The switches may or may not be electrically connected within the packaged half-bridge.

[0025] A packaged diode module (hereinafter also referred to as a packaged diode) may include one or more diode modules. The packaged diode module may be used in a converter or other power system.

[0026] The transistors and diodes in the converter and SSCB can operate at very high temperatures. Without cooling, the transistors and diodes can operate inefficiently or even fail. Cooling systems often include expensive electromechanical pumps that circulate coolant between the converter and a radiator, where heat exchange occurs. Unfortunately, electromechanical pumps can fail. Additionally, electromechanical pumps consume power from the battery of vehicles such as EVs and eVTOLs, thereby reducing their overall range. Liquid cooling systems also require tubing to fluidly connect the electromechanical pump, converter, and radiator. These tubing can clog or leak, causing excessive coolant leakage from the system or obstructing the flow of liquid, which can lead to converter shutdown. Furthermore, electromechanical pumps and tubing add weight, volume, cost, and complexity to the systems in which they are used, such as EVs, eVTOLs, and DC fast charging stations.

[0027] An "air-cooled" converter and an air-cooled SSCB are disclosed. While this disclosure is primarily described with respect to an air-cooled inverter (hereinafter also referred to as an inverter) and an air-cooled rectifier (hereinafter also referred to as a rectifier), it should be understood that this disclosure is also applicable to other types of air-cooled converters, such as air-cooled DC / DC converters or air-cooled AC / AC converters. Air-cooled converters may use packaged switches and / or packaged diodes. Air-cooled converters may use metal heat fins to cool the packaged switches and / or packaged diodes. Air-cooled converters may use metal heat fins and heat pipes to cool the packaged switches and / or packaged diodes. The power density of the disclosed air-cooled inverters can meet or exceed the 100 kW / L target set forth in the 2017 EETT roadmap, without the need for expensive liquid cooling systems. Current density can also be an important advantage of the disclosed power converters. For example, an inverter of the present disclosure may be able to carry the same amount of continuous current with fewer transistors than a prior art inverter having a larger volume.

[0028] Although the present disclosure will be described primarily with respect to inverters and rectifiers, it should be understood that one or more aspects of the present disclosure may also be applicable to other power converters, such as DC / DC converters, matrix converters, AC / AC converters, and other power systems, such as SSCBs.

[0029] Packaged Switches and Packaged Diodes Packaged switches and packaged diodes may have a cube shape with six sides: top, bottom, front, back, left side, and right side. Some packaged switches may conform to industry standard packaging aspects, such as the TO-247 package.

[0030] FIGS. 2A-1, 2A-2, and 2A-3 are top, bottom, and side views, respectively, of an exemplary packaged switch 247p. FIGS. 2B-1, 2B-2, and 2B-3 are top, bottom, and side views, respectively, of an exemplary packaged switch 247q. FIGS. 2C-1, 2C-2, and 2C-3 are top, bottom, and side views, respectively, of an exemplary packaged switch 247s. FIGS. 2D-1, 2D-2, and 2D-3 are top, bottom, and side views, respectively, of an exemplary packaged switch 247d. Packaged switches 247s and 247d are examples that conform to one or more aspects of the TO-247 packaging standard. FIGS. 2E-1, 2E-2, and 2E-3 are top, bottom, and side views, respectively, of an exemplary packaged diode 245.

[0031] case The packaged switch and packaged diode may have a case. FIGS. 2A-1 through 2A-3 show an example case 248p. FIGS. 2B-1 through 2B-3 show an example case 248q. FIGS. 2C-1 through 2C-3 show an example case 248s. FIGS. 2D-1 through 2D-3 show an example case 248d. FIGS. 2E-1 through 2E-3 show an example case 249.

[0032] The case may insulate, protect, and / or support switch module or diode module components, such as a power stack. The case may be composed of glass, plastic, ceramic, etc. For purposes of illustration, the case will be composed of a plastic, such as a molding compound like an epoxy resin. Modern molding compounds have evolved into complex formulations containing up to 20 different raw materials. Fillers such as alumina can be added to increase the thermal conductivity of the molding compound, which may aid in cooling the switch module and diode module components, including the transistors and diodes. The case may be formed around the switch module and diode module using any of a variety of packaging techniques, such as transfer molding.

[0033] The packaged switches and packaged diodes may be small. For example, the length lp, width wp, and height hp of the packaged diode 245, packaged switch 247q, packaged switch 247s, and / or packaged switch 247d, excluding connector leads 288, may be approximately 21 mm, 16 mm, and 5 mm, respectively. However, the size (e.g., 21 mm × 16 mm × 5 mm) and shape (e.g., cubic) of these packaged switches and packaged diodes are not limited to the disclosed subject matter and may vary. The length lp, width wp, and height hp of the packaged switch 247p, excluding connector leads 288, may be approximately 21 mm, 16 mm, and 12 mm, respectively. However, the size (e.g., 21 mm × 16 mm × 12 mm) and shape (e.g., cubic) of the packaged switch 247p are not limited to the disclosed subject matter and may vary. For example, the exemplary length, width, and / or height of the packaged switches 247p, 247q, 247s, or 247d described above may be doubled depending on the nature of the internal components, such as the power stack contained therein.

[0034] The size and shape of the packaged switch may depend on one or more factors, such as the number and / or type of transistors in the packaged switch. For example, a packaged switch 247d with six metal-oxide semiconductor field-effect transistors (MOSFETs) connected in parallel may be longer and / or wider than a packaged switch 247d with four MOSFETs connected in parallel. Or, a packaged switch 247q with two MOSFETs connected in parallel may be thinner than a packaged switch 247q with two MOSFETs connected back-to-back. Some transistors, such as IGBTs, may be wider and / or longer than other transistors, such as MOSFETs. A packaged switch 247d with four IGBTs connected in parallel may be longer and / or wider than a packaged switch 247d with four MOSFETs connected in parallel.

[0035] The exterior surface of the case may be substantially flat. "Substantially" is used to describe a feature such as flatness. The term "substantially" means that the feature has a variation within an acceptable tolerance. For example, a substantially flat surface refers to a surface whose flatness varies within an acceptable tolerance, such as 10.0 μm.

[0036] Switch Modules and Diode Modules Connection elements Switch modules and diode modules may include metal traces, bond wires, straps, leads, tabs, signal frames, etc., or other metal connection elements used to form an electrical path between two or more devices. Electrical connection elements may be used to transmit signals, including voltage signals and current signals.

[0037] Traces have flat surfaces and can be formed on rigid printed circuit boards (PCBs), flexible PCBs, direct bond copper (DBC) substrates, etc. Bond wires are small in diameter (e.g., 10 μm or less, up to several hundred micrometers). Straps, leads, tabs, and signal frames can be thicker than traces and bond wires and rated to carry significantly more current.

[0038] Straps, leads, bond wires, signal frames, etc. may be attached, bonded, connected, or adhered together or to traces, die clips, die substrates, paddles, control terminal pads, etc. Components may be attached, bonded, connected, or adhered via electrically conductive attaching, bonding, connecting, or adhesive materials such as solder or silver sinter paste. Components may be attached, bonded, connected, or adhered via dielectric or electrically insulating attaching, bonding, connecting, or adhesive materials. When a strap, lead, or other connecting element is attached, bonded, connected, or adhered to a device (e.g., die substrate) via a dielectric material, the device is electrically isolated from the strap, lead, or other connecting element.

[0039] The leads may be cylindrical "pins" and may have a square or rectangular cross section. For purposes of discussion, the straps, signal frames, tabs, and leads will be considered to have a square or rectangular cross section. The straps, tabs, signal frames, and leads may be formed (e.g., by cutting, sawing, dicing, stamping, etc.) from a sheet of electrically conductive material such as metal.

[0040] A switch module or diode module may include a DBC substrate. For example, the DBC substrate may be thermally attached (e.g., soldered) to the flat surface of a die substrate or die clip. A DBC substrate is a ceramic tile (typically alumina) with copper sheets bonded to both sides using a high-temperature oxidation process. (The copper and substrate are heated to a precisely controlled temperature in a nitrogen atmosphere containing approximately 30 ppm oxygen; under these conditions, a copper-oxygen eutectic mixture forms, successfully bonding both the copper and the oxide used as the substrate.) The upper copper layer is pre-formed before firing or chemically etched using PCB technology to form traces. Meanwhile, the lower copper layer is typically left bare when thermally attached to the flat surface of a die substrate or die clip. When used in a switch module or diode module, DBC substrates may have thermal advantages over rigid PCBs. For example, much of the heat generated by a device (e.g., a gate driver) can be dissipated through the DBC substrate on which the device is mounted.

[0041] The switch module or diode module may include a PCB. For example, the PCB may be attached to a flat surface of a die substrate or die clip. The PCB has flat conductor traces etched from one or more thin metal sheet layers laminated on and / or between non-conductive substrate sheet layers. Metal vias through the non-conductive substrate layers may electrically connect different levels of wiring. Exemplary packaged diode 245, packaged switch 247p, packaged switch 247q, packaged switch 247s, and packaged switch 247d do not include a PCB or DBC substrate.

[0042] Connection elements (e.g., traces, bond wires, signal frames, etc.) may transmit signals (e.g., gate control signals, temperature sensor output signals, current terminal voltage levels, etc.) between leads and components (e.g., transistors, temperature sensors, etc.) within the packaged switches and packaged diodes. Connection elements may transmit signals between components within the packaged switches and packaged diodes. Bond wires may transmit signals between transistor control terminals within the packaged switches and packaged diodes and straps or DCB substrates. Traces on the PCB or DCB substrate may transmit signals (e.g., PWM signals, gate control signals, temperature sensor signals, etc.), voltages (e.g., DC supply voltages), etc. Traces on the PCB or DCB substrate may transmit signals in an electrical path between components within the switch module or diode module (e.g., temperature sensors) and components external to the switch or diode module (e.g., microcontrollers). Flexible PCB traces may be used in converters to facilitate communication between data processing devices such as MCUs and other components such as drivers, voltage sensors, current sensors, etc., as described in more detail below.

[0043] A packaged diode or packaged switch may include one or more "connector leads." Ends of some connector leads may be electrically connected to a die substrate, paddle, die clip, etc. These may further be electrically connected to current terminals of a transistor or diode. Ends of some connector leads may be electrically connected to wires, straps, signal frames, etc. These may further be electrically connected to transistor control terminals. A packaged switch may include connector leads having ends electrically connected to straps via bond wires, and the straps may be connected to the die clip, paddle, or die substrate via material that electrically insulates the straps from the die clip, paddle, or die substrate.

[0044] Connector leads may extend laterally from the case. The connector leads of the packaged switch or packaged diode may mate with a "connector" external to the packaged switch or packaged diode. The connector may be attached to an external PCB (e.g., a driver PCB or control PCB, described in more detail below) on which a microcontroller, driver, voltage regulator, and / or other components may be mounted. The connector leads may transmit signals between components of the switch module or diode module and components on the external PCB.

[0045] 2A-1 to 2A-3 show connector leads 288g1, 288g2, 288c, 288dc, and 288ds. 2B-1 to 2B-3 show connector leads 288g1, 288g2, 288dc, and 288ds. 2C-1 to 2C-3 and 2D-1 to 2D-3 show connector leads 288g, 288dc, and 288ds. 2E-1 to 2E-3 show connector leads 288ds and 288dc.

[0046] Although not shown in FIGS. 2A-1 and 2B-1, connector lead 288g1 may be electrically connected to one or more first control terminals (e.g., gate terminals) of one or more first transistors within packaged switch 247p or 247q. Also, connector lead 288g2 may be electrically connected to one or more second control terminals (e.g., gate terminals) of one or more second transistors within packaged switch 247p or 247q. In some cases, connector leads 288g1 and 288g2 may be connected to respective control terminals of a transistor (e.g., a bidirectional bipolar junction transistor) within packaged switch 247q. Although not shown in FIGS. 2C-1 and 2D-1, connector lead 288g may be electrically connected to one or more control terminals (e.g., gate terminals) of one or more transistors within packaged switches 247s and 247d. Connector leads 228ds and 228dc may be electrically connected to the die substrate and the die clip, respectively. The connector lead 288c can be electrically connected to a paddle, which will be described below.

[0047] Power Stack The power stack may include a switch or diode that is electrically and thermally connected and disposed between the die substrate and the die clip, which may be formed from an electrically and thermally conductive material (e.g., a metal), as described below.

[0048] The die substrate and die clip may include die substrate terminals and die clip terminals, respectively. The packaged switch and packaged diode of Figures 2A-1 through 2E-3 show exemplary die substrate terminals 230 and die clip terminals 344.

[0049] The die substrate terminal 230 may have a width wds of approximately 13.5 mm and a length lds of approximately 16.5 mm. The die clip terminal 344 may have a width wdc of approximately 13.0 mm and a length ldc of approximately 16.0 mm. The length and width of the die substrate terminal 230 and the die clip terminal 344 may depend on the number and / or type of transistors in the switch disposed therebetween. For example, a packaged switch 247q having six metal-oxide semiconductor field-effect transistors (MOSFETs) connected in parallel may have die substrate terminals 230 and die clips 344, respectively, that are wider and / or longer than the die clip terminals 230 and 344, respectively, of a packaged switch 247q having only four MOSFETs connected in parallel. The packaged switch 247d having two IGBTs connected in parallel may have die clip terminals 230 and 344, respectively, which are wider and / or longer than the die clip terminals 230 and 344, respectively, of the packaged switch 247d having only two MOSFETs connected in parallel.

[0050] The length and width of the die substrate terminal 230 and die clip terminal 344 of the diode package 245 may depend on the number and / or type of diodes therebetween. A packaged diode 245 with four diodes connected in parallel may have die clip terminals 230 and 344, respectively, that are wider and / or longer than the die clip terminals 230 and 344, respectively, of a packaged diode 245 with only two diodes connected in parallel.

[0051] 2A-1 through 2E-3 can be electrically connected to the die substrate terminal 230 and the die clip terminal 344, respectively. The connector leads 288ds and 288dc can carry a large amount of current (e.g., 1, 5, 10, 25, 50, 100 amperes (A) or more). Although the connector leads 288 in FIGS. 2A-3, 2B-3, 2C-3, 2D-3, and 2E-3 are shown as being disposed in a common plane for purposes of illustration, the connector leads 288 need not be disposed in a common plane.

[0052] The switch module may include power stacks. Each power stack may include a switch thermally and electrically connected and disposed between a die substrate and a die clip. The die substrate may be directly connected (e.g., sintered) to the switch or indirectly connected to the switch through one or more electrically and thermally conductive components, such as a pedestal (described below). Similarly, the die clip may be directly connected (e.g., sintered) to the switch or indirectly connected to the switch through one or more electrically and thermally conductive components, such as a pedestal.

[0053] Two articles can be directly or indirectly connected, attached, bonded, or coupled. Two articles (e.g., a transistor and a die substrate, or a bus bar and a die substrate terminal) that are thermally and electrically connected, attached, bonded, or coupled can simultaneously conduct large amounts of current (e.g., 1, 5, 10, 50, 100, 200, 400 A or more) and large amounts of heat (e.g., 1, 2, 5, 10, 20, 40, 80, 100, 200, 400, 800, 1200, 1600 Watts or more) between them, directly or indirectly. Two articles that are thermally and electrically connected, attached, bonded, or coupled can simultaneously conduct large amounts of current and large amounts of heat between them via a direct connection, attachment, bond, or bond (e.g., a silver sintered connection, attachment, bond, or bond). Two items that are indirectly thermally and electrically connected, attached, joined, or coupled can simultaneously conduct large amounts of current and heat between them through one or more intervening items, such as a base. The surface areas of two items can be directly connected, attached, joined, or coupled by pressing the surface areas together using mechanical structures, such as clamps, screws, etc.

[0054] The thermal and / or electrical connection may be more than a simple point-to-point connection. Two items that are thermally and / or electrically connected, joined, attached, or coupled may be separated by a distance greater than or equal to the surface area of ​​each other (e.g., 1, 5, 10, 20, 50, 100, 200, 400 mm 2 (or more) may be directly connected, attached, bonded, or joined through a layer of connecting, attaching, bonding, or joining material, i.e., a flat surface-to-flat surface connection. A thermal and / or electrical connection, attachment, bonding, or joint that directly connects, attaches, bonds, or joins two items may directly fill substantially the entire space between the respective surface areas of the two opposing items.

[0055] The diode module may include power stacks. Each power stack may include at least one diode electrically and thermally connected and disposed between a die substrate and a die clip. The diode may be directly connected (e.g., sintered) to the die substrate or indirectly connected to the die substrate via one or more electrically and thermally conductive components, such as a pedestal. The diode may be directly connected (e.g., sintered) to the die clip or indirectly connected to the die clip via one or more electrically and thermally conductive components, such as a pedestal.

[0056] Sintering can be a process of forming connections, bonds, connections, or attachments by applying heat and / or pressure without melting the sintering material to its liquidus point. Prior to sintering a pair of articles, such as a die substrate and a transistor, a thin layer of sintering material (e.g., silver, a silver alloy, etc.) may be applied to one or both surfaces of the articles to be sintered. During the sintering process, atoms in the sintering material diffuse across the boundaries of the articles to be sintered, fusing them together and effectively forming a single solid article. The sintering temperature need not reach the melting point of the sintering material, nor does the sintering process need to reach the melting point of the articles (e.g., the die substrate and the transistor) being sintered together. Unlike soldering, sintering should not create bubbles or other voids that adversely affect thermal and electrical conductivity between the articles. While other methods of attaching articles can be used, sintering may be preferred because it can form a mechanically strong bond, especially compared to soldering. A strong bond is particularly important when subjected to extreme environmental stresses (e.g., thermal and / or mechanical stresses). For example, the joints may be subjected to severe mechanical stresses due to road vibrations while the electric vehicle is in motion. The joints may also be subjected to severe thermal stresses due to temperature cycling. Furthermore, the melting point of the sintered material is higher than the temperatures used in soldering, brazing, epoxy bonding, sintering, or other processes used in the manufacture of packaged switches, diodes, or converters, so these processes do not disturb the sintered connection.

[0057] The die clips and die substrates of the power stack may be substantially identical or may vary significantly in size, shape, and / or composition. The die substrate may vary in size, shape, and composition for different versions of the power stack. Similarly, the die clips may vary in size, shape, and / or composition for different versions of the power stack.

[0058] The switch may comprise one or more semi-controlled and / or fully controlled transistors (e.g., insulated gate bipolar transistors (IGBTs), reverse-blocking IGBTs (RB-IGBTs), non-punch-through IGBTs (NPT-IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), silicon-controlled rectifiers (SCRs), thyristors, symmetric-gate turn-off thyristors (GTO thyristors), bidirectional thyristors (BTs), bidirectional triode thyristors or TRIACs, bidirectionally controlled thyristors (BCTs), bipolar junction transistors (BJTs), bidirectional BJTs (BBJTs (also known as BTrans)), etc.). The switch may also comprise one or more diodes (e.g., normal diodes, Zener diodes, etc.) connected in parallel or anti-parallel with the one or more transistors. The transistors and / or diodes may be composed of any of a variety of semiconductor materials, such as Si, SiC, GaN, GaO, cubic boron arsenide, etc.

[0059] A transistor has two current terminals (e.g., collector and emitter terminals of an IGBT or BJT, source and drain terminals of a MOSFET, cathode and anode terminals of a thyristor, collector / emitter terminals of a BBJT, cathode / anode terminals of a BT, etc.) through which current can flow when the transistor is in an active or on-state. A diode may have two current terminals (e.g., a cathode and an anode). The current terminals may include one or more pads, each having a substantially flat surface that allows electrical and thermal connection. A first current terminal (e.g., drain terminal, collector, cathode, etc.) of the switch may be electrically and thermally connected through the body of the die substrate to a die substrate terminal, such as die substrate terminal 230 shown in FIGS. 2A-1 to 2E-1. A second current terminal (e.g., source, emitter, anode, etc.) may be electrically and thermally connected through the body of the die clip to a die clip terminal, such as die clip terminal 344 shown in FIGS. 2A-2 through 2E-2.

[0060] A transistor has a control terminal (e.g., a gate terminal of a MOSFET or IGBT, a base terminal of a BJT or BBJT, etc.). The transistor is controlled (operated or deactivated) by a signal received at its control terminal. Some transistors may be purely unidirectional, or capable of controllably allowing current to flow from a first terminal to a second current terminal when activated, and blocking current in the reverse direction (i.e., from the second current terminal to the first current terminal) when deactivated. Some transistors (e.g., MOSFETs) may be quasi-unidirectional, or capable of controllably allowing current to flow from a first terminal to a second current terminal when activated, but not capable of controlling current flow in the reverse direction when deactivated. A transistor may be bidirectional, or capable of controllably allowing current to flow in both directions between a first and second current terminal when activated, and blocking current flow in both directions between the first and second current terminals when deactivated. A BBJT is an example of a bidirectional transistor.

[0061] As described above, the current terminal may comprise one or more pads, each of which may have a substantially flat surface. A low-resistance path may exist between the current terminal pad of the power stack and the die substrate terminal 230. A low-resistance path may also exist between the current terminal pad of the power stack and the die clip terminal 344. The low-resistance path between the current terminal pad and the die substrate terminal 230 or the die clip terminal 344 may have a thermal resistance of 0.3, 0.2, 0.1, 0.05, 0.03, or 0.02°C / W or less and an electrical resistance of 16, 12, 10, 8, 6, 5, 4, or 3 ohms or less. The low-resistance path between the current terminal pad and the die substrate terminal 230 or the die clip terminal 344 should be free of dielectrics. The low-resistance path may comprise one or more connections, attachments, bonds, or joints (e.g., one or more sintered connections, attachments, bonds, or joints) between the current terminal pad and the die substrate or die clip. The low resistance path may further include a pedestal or other metal component between the current terminal pad and the die substrate or die clip. A low resistance path may mean that the cross-sectional area of ​​the path parallel to the surface of the current terminal pad does not substantially decrease from the current terminal pad to the die substrate terminal 230 or the die clip terminal 344. The cross-sectional area of ​​some low resistance paths parallel to the surface of the current terminal pad may increase from the current terminal pad to the die substrate terminal 230 or the die clip terminal 344, thereby improving heat spreading from the current terminal pad to the die substrate terminal 230 or the die clip terminal 344. A large amount of heat (e.g., 1, 2, 5, 10, 20, 50, 100, 200, 300, 750, 1500 watts or more) and current (e.g., 1, 5, 10, 50, 100, 200, 400 amps or more) can simultaneously flow from the current terminal pad to the die substrate terminal 230 or the die clip terminal 344 via the low resistance path. Ideally, the cross-sectional area of ​​the low resistance path between the current terminal pad and the die substrate terminal 230 or die clip terminal 344 should decrease as current and heat are conducted from the current terminal pad to the die substrate terminal 230 or die clip terminal 344.Ideally, the low resistance path between the current terminal pad and the die substrate terminal 230 or die clip terminal 344 should have a cross-sectional area equal to or greater than the surface area of ​​the current terminal pad.

[0062] The transistors in a switch may be connected in parallel (i.e., first current terminals are electrically connected and second current terminals are electrically connected). The transistors in a switch may be connected back-to-back (e.g., two transistors are connected in series, but their first current terminals or second current terminals are connected). The transistors in a switch may be connected in anti-parallel (e.g., two transistors are connected in parallel, but the first and second current terminals of the first transistor are connected to the second and first current terminals of the second transistor, respectively). A switch may be bidirectional or capable of controlling current flow in both directions. A switch may be bidirectional if it includes quasi-unidirectional transistors such as MOSFETs connected back-to-back. A switch may be bidirectional if it includes pure unidirectional transistors such as BJTs or IGBTs, including NPT-IGBTs or RB-IGBTs, connected anti-parallel. A switch may be bidirectional if it includes only one bidirectional transistor such as a BBJT or multiple bidirectional transistors connected in parallel.

[0063] The switches may be hybrids or mixtures of different types of transistors connected in parallel, back-to-back, or anti-parallel. For example, a hybrid switch may include one or more MOSFETs and one or more IGBTs connected in parallel (i.e., the drains and collectors are electrically connected and the sources and emitters are electrically connected). Other hybrid switches are also contemplated.

[0064] Different types of drivers may be required to control different types of transistors. Some gate drivers can activate or deactivate IGBTs but not MOSFETs, or vice versa. However, other drivers can control different types of transistors simultaneously. For example, some gate drivers can independently generate separate signals to control the gates of the MOSFETs and IGBTs in a switch. The independently controlled signals can be turned on at different times. For example, the independently controlled signals for each transistor can be asserted at different times.

[0065] Multiple transistors in a switch may be connected in parallel and controlled by a common signal received at their control terminals. Parallel-connected transistors in a switch may be controlled by respective independent control signals received at their control terminals. Groups of parallel-connected transistors in a switch may be controlled by respective independent control signals. All or some (e.g., one, two, or more, but less than all) parallel-connected transistors in a switch may be simultaneously in an operating state when controlled by respective independent control signals.

[0066] A pair of transistors in a switch may be connected in anti-parallel, or two groups of parallel-connected transistors in a switch may be connected in anti-parallel. Each pair of anti-parallel transistors may be controlled by its own independent signal, or two groups of parallel-connected anti-parallel transistors may be controlled by its own independent control signal. Only one pair of anti-parallel-connected transistors must be active at a time, and only one group of parallel-connected anti-parallel-connected transistors must be active at a time.

[0067] A pair of transistors in a switch may be connected back-to-back, or two groups of parallel-connected transistors in a switch may be connected back-to-back. A pair of back-to-back connected transistors may be controlled by independent signals, or two groups of parallel-connected back-to-back connected transistors may be controlled by independent control signals. Only one pair of back-to-back connected transistors in a switch must be active at a time, and only one group of parallel-connected back-to-back connected transistors must be active at a time.

[0068] The transistor or diode may be a vertically structured semiconductor device or die. A vertically structured transistor may have a trench-like structure with a first current terminal (e.g., drain terminal, collector terminal, collector / emitter terminal, etc.) on or near a first surface (e.g., bottom surface) of the die and a second current terminal (e.g., source terminal, emitter terminal, collector / emitter terminal, etc.) on or near an opposite second surface (e.g., top surface) of the die. A vertically structured transistor may have a control terminal (e.g., base terminal or gate terminal) on or near the top surface of the die. Some transistors, such as BBJTs or BCTs, may have a second control terminal on or near the bottom surface of the die. The cathode and anode terminals of a vertically structured diode may be on or near the opposite top and bottom surfaces, respectively.

[0069] The current terminals may comprise one or more electrically and thermally conductive (e.g., metallic) contact pads (hereinafter, pads), each of which may be in electrical or ohmic contact with an underlying doped semiconductor region (e.g., source, drain, emitter, collector, emitter / collector, anode, cathode, etc.). The control terminals may also comprise one or more pads. The control terminal pads may or may not be in ohmic contact with the underlying doped semiconductor region (e.g., gate, base, etc.). In an IGBT or MOSFET, a dielectric layer may electrically insulate the gate terminal pad from the underlying gate. The base terminal pad of a BJT or BBJT may be in electrical or ohmic contact with the underlying base.

[0070] The current terminal pad and the control terminal pad may be formed on the same side or surface of the transistor. The current terminal pad in the transistor may have a larger flat surface area than the control terminal pad of the transistor. The current terminal pad may have a flat surface that may be exposed to and configured for direct connection (e.g., sintered connection) with a corresponding flat surface of the die clip, die substrate, paddle, pedestal, etc. The current terminal pad may have a surface area sized to allow heat transfer to the thermally and electrically connected (e.g., sintered) die clip, paddle, pedestal, etc., with the larger surface area allowing for more heat transfer. The first current terminal pad surface (e.g., the drain and collector terminal pad surfaces of the MOSFET and IGBT (or BJT), respectively) may be 1, 2, 3, 4, 5, 6, 8, 10, 16, or 20 mm 2 The second current terminal pad surfaces (e.g., source and emitter terminal pad surfaces of a MOSFET and an IGBT (or BJT), respectively) may have a flat surface area of ​​1, 2, 3, 4, 6, 8, 10, 16 mm 2 The planar surfaces of the current terminal pads exposed on one side of the transistor may be contained within a common plane.

[0071] The exposed planar surfaces of the control terminal pads in a transistor (e.g., a BBJT, as described below) may be contained within a common plane. The control terminal pads may also have planar surfaces that are connected (e.g., by wire bonding, soldering, sintering, etc.) to bond wires, signal frames, etc.

[0072] The flat surfaces of the control terminal pads and the current terminal pads in the transistor may be in the same plane. The surfaces of the current terminal pads in the transistor may be contained in a plane that is higher than and parallel to a plane containing the surfaces of the control terminal pads. The current terminal pads in the transistor may be fabricated with a height higher than the control terminal pads, allowing the flat surface of the die substrate or die clip to be directly connected (e.g., sintered) to the flat surface of the current terminal pads while avoiding contact with the control terminal pads. An etched layer of photoresist may be formed on the wafer to cover the control terminal (gate terminal) pads while exposing the current terminal (e.g., source terminal) pads. Metal may then be deposited to increase the height of the current terminal pads. The photoresist layer may then be removed, leaving the exposed surfaces of the current terminal pads in a common plane that is higher than the common plane containing the surfaces of the control terminal pads. The additional height imparted to the current terminal pads may be considered a "pedestal."

[0073] The flat surfaces of the upper and lower terminal pads of a transistor or diode may face in opposite directions. In general, the outward normal vector to the average height of a first surface of a pair of opposing surfaces may point in the opposite direction to the outward normal vector to the average height of a second surface of the pair of opposing surfaces.

[0074] FIG. 2F shows a partial top or overhead view of an exemplary vertical structure BBJT 250. FIG. 2G shows a partial cross-sectional side view of the BBJT 250 taken along line 1-1 in FIG. 2F. Exemplary current and control terminal pads are shown in FIGS. 2G and 2F. With reference to FIG. 2G, the BBJT includes a first (e.g., upper) generally planar surface 252 and an oppositely facing second (e.g., lower) generally planar surface 254.

[0075] FIG. 2G shows collector / emitter regions 256 on one side, which may form a junction with a drift or bulk substrate 258, and collector / emitter terminal pads 262 electrically connected to each collector / emitter region 256. Collector / emitter terminal pads 262 define exposed planar surfaces 280. FIG. 2G shows base regions 260 disposed between collector / emitter regions 256 and base terminal pads 264 electrically connected to base region 260. Base terminal pads 264 define planar surfaces 282. Surfaces 280 and 282 are contained within a common plane, although it will be understood that surface 280 may be contained within a plane higher or lower than the plane containing surface 282. FIG. 2G shows collector / emitter regions 270 on the opposite side, which may form junctions with the bulk substrate 258, and collector / emitter terminal pads 272 electrically connected to each collector / emitter region 270. Collector / emitter terminal pads 272 define a planar surface 284. FIG. 2G shows base regions 276 and base terminal pads 278 electrically connected to base region 276. Base terminal pads 278 define a planar surface 286. Surfaces 284 and 286 are contained within a common plane, although it will be understood that surface 284 may be contained within a plane higher or lower than the plane containing surface 286. Although not shown in FIG. 2G, a BBJT may include multiple collector / emitter regions and multiple base regions on both sides. 2G shows only two collector / emitter terminal pads and one base terminal pad on each side, more than one collector / emitter terminal pad may be implemented on each side of the BBJT, and more than one base terminal pad may be implemented on each side of the BBJT. The terminal pads may be formed by depositing a metal material through a window in an insulating material (not shown) covering one side of a transistor such as a BBJT.

[0076] The exemplary BBJT 250 is of NPN construction, meaning that the collector / emitter regions 256 and 270 are N-type, the base regions 260 and 276 are P-type, and the bulk substrate 258 is P-type. Note that PNP-type BBJTs are also contemplated, but are not specifically shown to avoid unnecessarily lengthening this description.

[0077] 2F, collector / emitter region 256 defines a plurality of undoped interior regions 290. Within each exemplary interior region 290 is defined a base region 260.

[0078] The switch can transmit high levels of current (e.g., 1, 5, 10, 50, 100, 200, 400 amperes, or more) between the die clip and die substrate without failure, depending on the size (e.g., width and length of the current terminals), type (e.g., MOSFET), semiconductor material (e.g., GaN), and number of transistors connected in parallel and in operation. The transistors can transmit high levels of current (e.g., 1, 5, 10, 50, 100, 200, 400 amperes, or more) at high switching speeds (e.g., 100 kHz or more for Si IGBTs, 500 kHz or more for SiC MOSFETs, 1.0 GHz or more for GaN MOSFETs, etc.) between their current terminals. When thermally connected to and cooled by a heat sink or a bus bar that also functions as a heat sink, the transistors can transmit greater currents at higher switching speeds without breaking, delaminating, or degrading. Similarly, if the diodes are thermally connected to and cooled by a heat sink or a bus bar that also acts as a heat sink, they can carry more current without breaking, delaminating, or degrading.

[0079] The switch may be electrically and thermally connected to and sandwiched between the die substrate and the die clip. The first current terminal (e.g., collector terminal, drain terminal, etc.) pad and the second current terminal (e.g., emitter terminal, source terminal, etc.) pad of the transistor in the switch may be directly or indirectly connected to the die substrate and the die clip, respectively, or vice versa. The flat surfaces of the first current terminal pad and the flat surfaces of the second current terminal pad of the transistor in the switch may be indirectly connected to the flat surfaces of the die substrate and the die clip, respectively, or vice versa. The flat surfaces of the first current terminal pad of the transistor may be directly connected to the flat surface of the die substrate, and the flat surfaces of the second current terminal pad may be indirectly connected to the flat surface of the die clip, or vice versa. The flat surfaces of the first current terminal pad of the transistor may be directly connected to the flat surface of the die clip, and the flat surfaces of the second current terminal pad of the transistor may be directly connected to the flat surface of the die substrate, or vice versa. A direct connection involves only sintering or other types of bonding material between the current terminal pad surface and the surface of the die substrate or die clip. The current terminal pad may be indirectly connected to the die clip or die substrate via an electrically and thermally conductive pedestal having a flat end face sintered to the flat surface of the current terminal pad.

[0080] The switch may include multiple transistors, each electrically and thermally connected to and sandwiched between a die clip and a die substrate. The flat surfaces of the first and second current terminal pads of the parallel-connected transistors in the switch may be directly or indirectly connected to the flat surfaces of the die substrate and die clip, respectively, or vice versa. The flat surfaces of the first and second current terminal (e.g., collector) pads of a first transistor (e.g., a first RB-IGBT) in the switch and the flat surfaces of the second current terminal (e.g., emitter) pads of a second transistor (e.g., a second RB-IGBT) in the switch may be directly or indirectly connected to the flat surfaces of the die substrate, and the flat surfaces of the second and second current terminal (e.g., emitter) pads of the first and second transistors may be directly or indirectly connected to the flat surfaces of the die clip, or vice versa. The planar surfaces of the first current terminal (e.g., drain) pads of the first and second transistors in the switch may be directly or indirectly connected to the planar surfaces of the die substrate and the die clip, respectively, and the second current terminal (e.g., source) pads of the first and second transistors may be indirectly connected to each other.

[0081] The control terminal (e.g., gate terminal, base terminal, etc.) pads of one or more transistors in the switch may be controlled by a voltage or current signal from a driver, and the control terminals of each transistor or each group of transistors in the switch may be controlled by a respective voltage or current signal from a respective driver. Effective control of different types of transistors may require different types of drivers. The drivers may be configured to control the different types of transistors separately. The control terminals of the BBJTs may be controlled by separate signals from the drivers or by separate control signals from their respective drivers.

[0082] The control terminal pads may be located on only one side of some transistors (e.g., MOSFETs and IGBTs), while on opposing sides of other transistors (e.g., BBJTs). The control terminal pads may be located adjacent to current terminal (e.g., source or emitter) pads of some transistors (e.g., MOSFETs or IGBTs), while they may be interspersed between current terminal (e.g., collector / emitter) pads of other transistors (e.g., BBJTs).

[0083] The transistor control signals may be transmitted from the drivers to the control terminal pads in electrical paths that include leads, wires, straps, bond wires, signal frames, etc., or a series combination of two or more thereof. In some switch modules, bond wires may be wire-bonded to the control terminal pads. In some switch modules, signal frames may be soldered to one or more control terminal pads.

[0084] One or more pedestals in a power stack may be electrically and thermally connected and positioned between the transistor and the die clip, paddle, bridge, or die substrate. The pedestals may be configured to provide space for bond wires below the die clip, paddle, or die substrate. In some power stacks, one or more pedestals are electrically and thermally connected and positioned between the transistor and the die clip, and one or more pedestals are electrically and thermally connected between the transistor and the paddle or die substrate. The pedestals may be configured to allow liquid molding compound (e.g., liquid resin) to flow around them during transfer molding packaging of the switch module or diode module, thereby forming a package in which the molding compound (e.g., resin) electrically insulates the exposed surfaces of the facing die clip and die substrate. The molding compound may also cover exposed bond wires, straps, signal frames, current terminal pads, and / or control terminal pads.

[0085] One or more diodes may be electrically and thermally connected to and sandwiched between the die substrate and the die clip. The flat surfaces of the first current terminal (e.g., anode terminal) pad and the flat surfaces of the second current terminal (e.g., cathode terminal) pad of the diode may be directly or indirectly connected to the die substrate and the die clip, respectively, or vice versa. Similar to a switch, the current terminal pad of the diode may be indirectly connected to the die substrate or the die clip via a pedestal sintered to the pad, or a direct connection may include sintering or other types of bonding material between the current terminal pad and the die substrate or the die clip. Because the diode does not have a control terminal, it does not need to accommodate bond wires. The first current terminal pad and the second current terminal pad of the diode may be directly connected (e.g., sintered) to the flat surfaces of the die clip and the die substrate, respectively.

[0086] The die clip can pass a large amount of current into or out of the packaged switch or packaged diode through its die clip terminals while simultaneously dissipating a large amount of heat from the packaged switch or packaged diode through its die clip terminals. The die substrate can pass a large amount of current into or out of the packaged switch or packaged diode through its die substrate terminals while simultaneously dissipating a large amount of heat from the packaged switch or packaged diode through its die substrate terminals.

[0087] The pedestal can allow a large amount of current to flow into or out of a current terminal pad electrically and thermally attached (e.g., sintered) to the pedestal, while simultaneously dissipating a large amount of heat from the current terminal pad electrically and thermally attached to the pedestal. The flat end surface of the pedestal may be directly connected (e.g., sintered) to the flat surface of only one current terminal pad, or the flat end surface of the pedestal may be directly connected (e.g., sintered) to the surfaces of multiple current terminal pads in a transistor or diode. The pedestals in a switch module or diode module may be structurally identical. Some switch modules may not use a pedestal, and opposing current terminal pad surfaces of a transistor or diode may be directly connected (e.g., sintered) to the respective surfaces of the die clip and die substrate. Similarly, some packaged diodes may not use a pedestal, and opposing current terminal pad surfaces may be directly connected (e.g., sintered) to the respective surfaces of the die clip and die substrate.

[0088] The power stack may include additional electrically and thermally conductive components, such as bridges and paddles, as described below. Pedestals and other components (e.g., bridges) may provide low-resistance electrical and thermal paths between the current terminal pads and the die clip or die substrate. The flat end faces of the pedestal may be directly attached (e.g., sintered) to the flat surfaces of the current terminal pads, and the opposing flat end faces of the pedestal may be directly attached (e.g., sintered) to the flat surfaces of the die clip, paddle, or die substrate. Alternatively, the opposing flat end faces of the pedestal may be indirectly attached to the flat surfaces of the die substrate, paddle, or die clip via one or more intermediate components, such as bridges, as described below. In other versions, the opposing end faces of the pedestal may be directly attached to the current terminal (e.g., source) pads of a pair of back-to-back connected transistors.

[0089] The die substrate, die clip, pedestal, paddle, and bridge may be formed using different methods. The die substrate, die clip, pedestal, paddle, and bridge may be formed by 3D printing. The die substrate, die clip, paddle, pedestal, and bridge may be formed by extrusion molding. The die substrate, die clip, paddle, pedestal, and bridge may be formed by a sintering process in which pressure and heat are applied to sintered powder in a mold to form a solid mass without melting it to the liquidus point. The die substrate, die clip, pedestal, paddle, and bridge may be formed from a thin sheet of highly conductive material. Before or after forming the die substrate, die clip, paddle, pedestal, or bridge, a layer of sintering-facilitating material (e.g., silver or a silver alloy) may be formed on the surface of the die substrate, die clip, paddle, pedestal, or bridge (e.g., by electrolytic plating). Barrel plating may be used to form a thin layer of sintered material on the surface of the die substrate, die clip, paddle, pedestal, etc. The barrel plating process involves placing an article (e.g., a pedestal) in a barrel-shaped cage made of non-conductive material. The cage is then submerged in a tank filled with the appropriate chemical solution and slowly rotated to initiate the plating process. The die substrate, pedestal, die clip, bridge, paddle, etc. must not contain any dielectric elements.

[0090] Die clips, die substrates, paddles, pedestals, bridges, etc. may be formed (e.g., by machining, cutting, punching, sawing, dicing, etc.) from thin (e.g., 0.1 mm to 3.0 mm) sheets of one or more metal layers. The term metal includes pure metals (e.g., copper, iron, aluminum, gold, silver, molybdenum, etc.) or metal composites. Metal composites are made by combining two or more different materials, at least one of which is a pure metal.

[0091] Thin (e.g., 3.0, 2.0, 1.0, 0.5, 0.3, 0.2, 0.1 mm or less) sheets from which die substrates, die clips, paddles, pedestals, or bridges are formed (e.g., by machining, cutting, punching, sawing, dicing, etc.) may be stacked. Two or more layers of the stacked sheets may be substantially uniform in thickness. Each layer of the stacked sheets may be metal, or each layer of the stacked sheets may be a metal composite. One or more layers of the stacked sheets may be metal, or one or more layers of the stacked sheets may be a metal composite.

[0092] For purposes of explanation, this disclosure will refer to die substrates, die clips, paddles, pedestals, and bridges formed from sheets of highly conductive material. For purposes of explanation, die substrates, die clips, paddles, pedestals, and bridges that are directly connected (e.g., sintered) to the current terminal pad surfaces of transistors or diodes will refer to die substrates, die clips, paddles, pedestals, and bridges that are directly connected (e.g., sintered) to the current terminal pad surfaces of transistors or diodes as being formed from laminated sheets unless otherwise specified.

[0093] FIG. 2H shows a side view of a portion of an exemplary laminate sheet 265 from which a pedestal, paddle, bridge, die clip, die substrate, or other component can be formed. The laminate sheet 265 may be 0.5 to 1.16 mm between opposing first and second flat surfaces 275 and 277. Section 271 may be comprised of a central layer 266 of metal (e.g., molybdenum, which may be suitable for attaching a die substrate or pedestal to a low CTE (e.g., SiC)-based device such as a MOSFET or diode) or metal composite (copper / diamond, copper / molybdenum, copper / tungsten, etc.) between layers 267 of metal (e.g., copper) or metal composite. Note that layers 266 may be made of materials other than molybdenum. Section 271 may be sandwiched between layers 268 of metal (e.g., nickel) or metal composite, as shown. The nickel layer 268 may prevent copper from migrating to the silver layer 269. Layer 268 may be formed (e.g., by electroplating) on ​​layer 267. Section 273 may be sandwiched between layer 269 of a sintering-facilitating material (e.g., silver) as shown. Layer 269 may be formed (e.g., by electroplating) on ​​layer 268. For purposes of illustration, layers 268 and 269 are formed before the pedestal, paddle, bridge, die clip, die substrate, or other component is formed from the sheet. In other versions, one or both of layers 268 and 269 may be added to the pedestal, paddle, bridge, die clip, die substrate, or other component after the pedestal, paddle, bridge, die clip, die substrate, or other component is formed from a sheet consisting only of layers 266 and 267.

[0094] Layer 266 may have a thickness tc that is approximately equal to thickness t1 of layer 267. For example, tc and t1 may both be 0.30 to 0.35 mm. Layer 266 may have a thickness that is greater than or less than thickness t1 of layer 267. For example, layer 266 may be twice or four times as thick as layer 267, or layer 266 may be half or less thick than layer 267. Layers 268 and 269 may have approximately the same thickness. For example, each of t2 and t3 may be 0.005 to 0.015 mm.

[0095] The properties, such as thicknesses tc and t1, and composition of planar layers 266 and 267 can be varied. Layer 267 may have a higher thermal conductivity compared to layer 266, providing more efficient heat spreading properties. Center layer 266 may have a lower coefficient of thermal expansion (CTE) than layer 267. As discussed below, CTE can be a factor that affects the mechanical integrity of connections between bridges, pedestal edges, die substrates, paddles, die clip surfaces, etc., and transistors or diodes.

[0096] The flat surfaces of the current terminal pads may be electrically and thermally connected (e.g., sintered) directly to flat surfaces (i.e., 275 or 277) of the bridge, pedestal edge, die substrate, paddle, die clip surface, etc. formed from sheet 265. The sintered connection may be formed, for example, using silver or copper sinter paste, film, or preform. Components with different CTEs may expand and contract at different rates with temperature changes. The composition and / or thickness of layers 266 and 277 may be selected so that the CTE of the die substrate, die clip, pedestal, paddle, bridge, etc. is close to or substantially equal to the CTE of the transistor or diode to which the die substrate, die clip, pedestal, paddle, bridge, etc. is connected (e.g., sintered). Similar CTEs can reduce the likelihood of, for example, the drain terminal pad of a MOSFET peeling or delaminating from the die substrate surface due to mechanical stress or strain caused by differences in expansion or contraction rates between the die substrate and the MOSFET as the MOSFET is cycled between high and low temperatures. The composition and / or thickness of layers 266 and 267, such as the bridge, pedestal edge, die substrate, paddle, and die clip surface, may be selected based on one or more factors, such as the type of transistor or diode to which it is attached. For example, providing a molybdenum or molybdenum / copper layer 266 between copper layers 267 of the die substrate results in a CTE that is close to or approximately equal to the CTE of a Si CMOSFET to which the die substrate is attached by silver sintering.

[0097] The die substrate, die clip, bridge, or paddle may be formed with an integral pedestal. A bridge with an integral pedestal (hereinafter "integral bridge") may be formed (by machining, cutting, stamping, sawing, dicing, etc.) from a sheet of metal or metal composite, or a laminated sheet as shown in Figure 2H.

[0098] The die substrate may have only one terminal exposed through the case of the packaged switch or packaged diode, through which heat and current are transmitted. The die substrate terminal may have a flat surface for mechanically, electrically, and thermally mating with a flat surface of, for example, a bus bar. The surface of the die substrate terminal may be completely flat.

[0099] The die clip may have only one terminal exposed through the case of the packaged switch or packaged diode, through which heat and current are transmitted. The die clip terminal may have a flat surface for mechanically, electrically, and thermally mating with a flat surface of, for example, a bus bar. The surface of the die clip terminal may be completely flat.

[0100] The die substrate terminals or die clip terminals may have completely flat surfaces that are substantially flush with or coplanar with the case surface of the packaged switch or packaged diode in which they are housed. In other versions, the surfaces of the die substrate terminals or die clip terminals may be completely flat and substantially parallel to and recessed from the case surface, or parallel to and protruding from the case surface. Some die clip terminals may not be exposed through the case of the packaged switch (e.g., packaged switch 247s).

[0101] 2A-1 through 2E-2 illustrate exemplary die substrate terminals 230 and exemplary die clip terminals 344. FIGS. 2C-1 through 2C-3 illustrate an example packaged switch 247s in which the die clip terminals are not exposed through the case 248s. While FIGS. 2A-1 through 2E-2 show that the die substrate terminals 230 and die clip terminals 344 are rectangular, have perfectly flat surfaces, and are parallel and slightly above, parallel and slightly below, or nearly flush with the flat case surface of the packaged switch 247 and packaged diode 245, the terminals 230 and 344 may appear to be flush with the case surface.

[0102] The size and shape of the die substrate terminals or die clip terminals should not be limited to those shown in the drawings. In other words, the die substrate terminals and die clip terminals may have different forms, shapes, and sizes. The die clip terminals or die substrate terminals may have one or more recesses that can mate with similarly shaped protrusions on an external device (e.g., a phase bus bar, a V+ bus bar, a V- bus bar, etc., as described below), thereby facilitating electrical, thermal, and / or mechanical connection therebetween. Alternatively, the die clip terminals or die substrate terminals may have one or more protrusions that can mate with similarly shaped recesses on an external device (e.g., a phase bus bar, a V+ bus bar, a V- bus bar, etc.), thereby facilitating electrical, thermal, and / or mechanical connection therebetween.

[0103] Current can flow into the packaged switch or packaged diode through the die substrate terminal and then out through the die clip terminal. Or, current can flow in the reverse direction through the packaged switch or packaged diode. For example, current can flow into the packaged switch 247d through the die substrate terminal 230 of the die substrate, through the die substrate, the switch, the die clip, and then out through the die clip terminal 344 of the packaged switch 247d. Or, current (e.g., freewheeling diode current) can flow in the reverse direction. Current can flow into the packaged diode 245 through the die substrate terminal 230 of the die substrate, through the die substrate, the diode, the die clip, and then out through the packaged diode 245 through the die clip terminal 344. Or, current (e.g., reverse recovery current) can flow in the reverse direction.

[0104] The die substrate and die clip can transmit a large amount of current to or from the respective connected switches or diodes while simultaneously dissipating a large amount of heat from the respective connected switches or diodes. The die substrate terminals and die clip terminals can transmit a large amount of current into or out of the packaged switches or diodes while simultaneously dissipating a large amount of heat from the packaged switches or diodes. For example, the die substrate terminals 230 in FIG. 2A-1, 2B-1, 2C-1, 2D-1, or 2E-1 can be flat, have a width wds of about 14.5 mm and a length lds of about 17.5 mm, and can be electrically connected to the flat surface of a bus bar. The die substrate can transmit 50, 100, 200, 400 A, or more of current between the connected switches or diodes and the bus bar through the die substrate terminals 230. The die clip terminal 344 of Figures 2A-2, 2B-2, 2D-2, or 2E-2 may have a width wdc of approximately 14.0 mm and a length ldc of approximately 17.0 mm and may be thermally and electrically connected to a flat surface of a bus bar. The die clip may transmit currents of 50, 100, 200, 400 A, or more between the connected switch or diode and the bus bar through the die clip terminal 344. The connector leads 288ds or 288dc of Figures 2A-1 through 2E-3 may transmit currents of 10, 40, 80, 100, 200 A, or more, to or from the packaged switch or packaged diode.

[0105] Transistors in switches can become hot due to conduction and switching losses, especially when carrying high currents at high switching speeds. Diodes can also become hot when carrying current. Depending on their dimensions, the die substrate can conduct a large amount of heat generated by the transistor or diode to the exterior of the packaged switch or diode through the die substrate terminals. For example, the die substrate terminals 230 in FIG. 2A-1, 2B-1, 2C-1, 2D-1, or 2E-1 may be approximately 14.5 mm wide and approximately 17.5 mm long. The flat surfaces of the die substrate terminals 230 may be electrically and thermally connected to a heat sink or to the flat surfaces of a bus bar that also functions as a heat sink. The die substrate terminals 230 can dissipate 0 to 750 watts or more of heat from the packaged switch 247p, 247q, 247s, or 247d or packaged diode 245. In other words, the die substrate terminals 230 can conduct 10, 20, 50, 100, 200, 300, 750 watts or more of heat. The die substrate may have a thickness (e.g., 0.5, 0.8, 1.0, 2.0, 4.0, 8.0 mm or more when measured between opposing surfaces), the greater the thickness, the greater the heat capacity, which may be important in absorbing sudden heat gains from an attached switch or diode.

[0106] Like the die substrate, the die clip can conduct a large amount of heat generated by the transistor or diode to the exterior of the packaged switch or packaged diode through the die clip terminals. For example, the die clip terminals 344 of FIG. 2A-2, 2B-2, 2D-2, or 2E-2 may be approximately 14.0 mm wide and approximately 17.0 mm long and may be electrically and thermally connected to a heat sink or a flat surface of a bus bar that also functions as a heat sink. The die clip terminals 344 can dissipate heat from 0 to 750 watts or more from the packaged switch 247p, 247q, 247d, or packaged diode 245. In other words, the die clip terminals 344 can conduct 10, 20, 50, 100, 200, 300, 750 watts, or more. The die clip may have a thickness (e.g., 0.5, 0.8, 1.0, 2.0, 4.0, 8.0 mm or more when measured between opposing surfaces), the greater the thickness, the greater the thermal capacity, which may be important in absorbing sudden heat gains from the attached switch or diode.

[0107] Although not shown in FIGS. 2A-1 through 2E-3, the packaged switches 247p, 247q, 247d, and 247s or the packaged diode 245 may include one or more pedestals. The pedestals may have different sizes, shapes, and compositions. For illustrative purposes, each pedestal or integrated bridge is formed from a laminated sheet as shown in FIG. 2H, and layer 266 may be a metal other than molybdenum if the pedestal or integrated bridge is directly attached (e.g., sintered) to a non-SiC-based device (e.g., a transistor) (e.g., a GaN-based MOSFET). Each pedestal may have opposing first and second substantially flat (e.g., within a 0.01 mm tolerance) end faces. The first and second end faces may be completely flat. Multiple pedestals in a power stack may be substantially identical in size, shape, and composition. Groups of one or more pedestals in a power stack may be substantially different in size, shape, and composition.

[0108] The pedestal may have a uniform cross-section between the first and second opposing flat end faces. Alternatively, the pedestal may have a non-uniform cross-section between the first and second opposing flat end faces. For example, the cross-sectional width near the first flat end face that is directly connected (e.g., sintered) to the flat surface of the current terminal pad may be smaller than the cross-sectional width near the second flat end face.

[0109] A first flat end surface of the pedestal may be directly thermally and electrically connected (e.g., sintered) to a flat surface of a current terminal pad of each of the transistors in the power stack, and a second flat end surface of the pedestal may be directly thermally and electrically connected (e.g., sintered) to a flat surface of the die substrate or die clip opposite the side having the die substrate terminals 230 or die clip terminals 344. Alternatively, the second flat end surface of the pedestal may be directly thermally and electrically connected (e.g., sintered) to a flat surface of a bridge, the bridge comprising an opposing flat surface that is directly thermally and electrically connected (e.g., sintered) to a flat surface of the die substrate or die clip opposite the side having the die clip terminals 344 or die substrate terminals 230.

[0110] A first flat end face of the single pedestal may be directly thermally and electrically connected (e.g., sintered) to a flat surface of a current terminal pad of a transistor in the power stack, and a second flat end face of the pedestal may be directly thermally and electrically connected (e.g., sintered) to a flat surface of the die substrate or die clip opposite the side having the die substrate terminal 230 or die clip terminal 344. Alternatively, the second flat end face of the single pedestal may be directly thermally and electrically connected (e.g., sintered) to a flat surface of a bridge, the bridge comprising an opposing flat surface that is directly thermally and electrically connected (e.g., sintered) to a flat surface of the die substrate or die clip opposite the side having the die clip terminal 344 or die substrate terminal 230.

[0111] The one or more first transistors may be electrically connected back-to-back to one or more second transistors in the power stack. The first flat end surface of the pedestal may be electrically and thermally connected (e.g., sintered) to a respective flat current terminal (e.g., source) pad of the first transistor, and the second flat end surface of the pedestal may be electrically and thermally directly connected (e.g., sintered) to a respective flat current terminal (e.g., source) pad of the second transistor in the power stack. Alternatively, the first flat end surface of the pedestal may be electrically and thermally directly connected (e.g., sintered) to a respective pair of flat current terminal (e.g., source) pads of the first transistor, and the second flat end surface of the pedestal may be electrically and thermally directly connected (e.g., sintered) to a respective pair of flat current terminal (e.g., source) pads of the second transistor in the power stack.

[0112] The pedestal may be integrally formed from and extend from a surface of the die substrate or die clip opposite the side having the die substrate terminals 230 or die clip terminals 344, respectively. Alternatively, the pedestal may be integrally formed from and extend from a flat surface of the bridge opposite the side that is connected (e.g., sintered) to the die substrate or die clip. In this alternative version, a first flat end face of the pedestal may be directly electrically and thermally connected (e.g., sintered) to a respective flat surface or respective pair of current terminal pads of one or more transistors in the power stack.

[0113] The first flat end face of the pedestal may have a shape substantially equal to the shape of the flat surface of the connected current terminal pad. The first end of the pedestal may have a flat surface area configured to connect to the flat surface of a pair of adjacent current terminal pads in the transistor. The flat surface of the current terminal pad may be connected to the first flat surface of the pedestal, paddle, die clip, die substrate, etc. using any of a variety of attachment techniques (e.g., sintering, soldering, transient liquid phase bonding, conductive adhesive processes, etc.). The second opposing flat end face of the pedestal may be connected to the flat surface of the paddle, die clip, die substrate, etc. using any of a variety of attachment techniques (e.g., sintering, soldering, transient liquid phase bonding, conductive adhesive processes, etc.).

[0114] In the past, bond wires have been used to transmit large currents (1 A or greater) in power converters. The connections from N1 to TL1, N2 to TL2, and N3 to TL3, and from V+ to TH1, TH2, and TH3 in FIGS. 1A and 1C, may consist of one or more bond wires (not shown) wire-bonded to the current terminal pads of the IGBTs. These bond wires are prone to failure during temperature cycling. For example, the bond wires or bond wire connections often crack or break during temperature cycling. Lift-off of the bond wires can also occur. This failure may be due to relatively high current densities and low heat capacity in the bond wires themselves or in the connections between the bond wires and the current terminal pads. In contrast, the pedestal has a large cross-sectional area, resulting in a lower current density and a higher heat capacity compared to the bond wires. Additionally, the connection (e.g., a sintered connection) between the flat surface of the current terminal pad and the flat surface of the connected pedestal may experience low current densities. Such bond wire-related failures are less likely to occur when the end face of the pedestal is connected (e.g., sintered) to the current terminal pad surface. Pedestals have additional advantages over bond wires, such as low parasitic parameters (e.g., inductance, resistance, and capacitance). The parasitic inductance in the electrical path between the die substrate terminal and the die clip terminal in the packaged switch, including the pedestal, may be 0.15 nH or less. Low parasitic inductance may improve the operational behavior of the packaged switch.

[0115] A pair of components may be directly or indirectly connected, attached, bonded, or coupled. A pair of components may be directly connected, attached, bonded, or coupled by soldering, sintering, brazing, adhesive bonding, etc. Materials used to solder, sinter, braze, adhesively, etc. a pair of components may be electrically and / or thermally conductive. A pair of components may be directly connected, attached, bonded, or coupled by pressing (i.e., "press-fit") the surfaces of the components together using mechanical structures such as clamps and bolts. Thus, a pair of components may be directly connected, attached, bonded, or coupled without an intervening material (e.g., solder, sintered material, conductive adhesive, thermal interface material (TIM), electrically insulating adhesive, etc.) between them. A pair of components may be indirectly connected, attached, bonded, or coupled through one or more additional components (e.g., die substrate, die clip, pedestal, transistor, wire, ribbon, lead, wiring, etc.).

[0116] Packaging Switch 247 Example With continued reference to Figures 2A-1-2A-3, 2B-1-2B-3, and 2D-1-2D-3, Figures 3A-3L, 3O, and 3P illustrate example packaged switches 247p, 247q, or 247d from a side view. In Figures 3A-3L, 3O, and 3P, the case (e.g., case 248) is shown as transparent to facilitate a better understanding of the packaged switch components, their interactions, and relative positions. Additionally, connector leads 288ds and 288dc are not shown for ease of understanding.

[0117] The example packaged switch 247 shown in Figures 3A-3L, 3O, and 3P includes switch modules 376A-376L, 376O, and 376P, respectively, each including a power stack with a switch 304 electrically and thermally connected between a die substrate 360 ​​and a die clip 372, both shown symbolically. Die substrate terminals 230 and die clip terminals 344 are also shown symbolically. Figure 3K also includes a paddle 361, shown symbolically. Although not shown in Figure 3K, paddle 361 may include opposing flat surfaces to which the flat ends of the respective pedestals are directly connected (e.g., sintered).

[0118] The surfaces of die substrate terminals 230 and die clip terminals 344 may be completely flat and flush with the respective surfaces of case 248. Alternatively, the surfaces of die substrate terminals 230 and die clip terminals 344 may be completely flat and recessed or protruding from the surface of case 248. The switch module components, including die substrate 360 ​​and die clip 372, may vary in size, shape, composition, etc., between packaged switches 247 of Figures 3A-3L, 3O, and 3P.

[0119] 3A-3L, 3O, and 3P, each power stack may include one or more pedestals, each of which may have completely flat opposing first and second end faces. The first flat end face of the pedestal may be directly connected (e.g., by sintering, soldering, transient liquid phase bonding, a conductive adhesive process, etc.) to one or more current terminal pads of the transistors of switch 304, and the second flat end face of the pedestal may be directly connected (e.g., by sintering, soldering, transient liquid phase bonding, a conductive adhesive process, etc.) to a flat surface of die substrate 360 ​​or die clip 372 opposite the side having die substrate terminal 230 or die clip terminal 344. Alternatively, the second flat end face of the pedestal may be directly connected to a flat surface of the bridge, with the bridge having an opposing flat surface that is directly connected (e.g., by sintering, soldering, transient liquid phase bonding, conductive adhesive process, etc.) to the flat surface of the die substrate 360 ​​or die clip 372 opposite the side having the die clip terminal 344 or die substrate terminal 230. Alternatively, the second flat end face of the pedestal may be directly connected to one or more current terminals of another transistor. The pedestal may be integrally formed and extend from the flat surface of the bridge, with the bridge having an opposing flat surface that is directly connected to the flat surface of the die substrate 360 ​​or die clip 372 opposite the side having the die clip terminal 344 or die substrate terminal 230.

[0120] 3A-3P illustrate the relative positioning of the components. The die substrate 360, switch 304, and die clip 372 may be stacked as shown. In one sense, stacking the first and second components means that the first and second components are disposed in first and second planes, respectively, that are separated but parallel to each other. The first component in the first plane may be disposed directly above the second component in the second plane, or the first component may be laterally offset within the first plane, such that the second component is not directly below the first component. Current may be transmitted between the die clip terminal 344 and the die substrate terminal 230 through the actuated switch 304.

[0121] The switch module 376 may include connector leads 288g, 288ds, 288c, and 288dc, although connector leads 288dc and 288ds are not shown in FIGS. 3A-3P for ease of illustration. Connector lead 288g may be electrically connected to the control terminal pads of each transistor of the switch 304 of FIGS. 3A-3D and 3O. Connector lead 288g1 may be electrically connected to the control terminal pads of one or more first transistors of the switch 304 of FIGS. 3E-3L and 3P. Connector lead 288g2 may be electrically connected to the control terminal pads of one or more second transistors of the switch 304 of FIGS. 3E-3L and 3P. In FIGS. 3G and 3L, the one or more first transistors are identical to the one or more second transistors.

[0122] Die substrate 360 ​​and die clip 372 can direct large currents (e.g., 1, 5, 10, 50, 100, 200, 400 A, or more) to and from packaged switches 247q, 247d, and 247p via die substrate terminals 230 and die clip terminals 344, respectively. Switch 304 can become hot. Die substrate 360 ​​and die clip 372 can dissipate large amounts of switch heat from packaged switch 247 via die substrate terminals 230 and die clip terminals 344, respectively, while die substrate terminals 230 and die clip terminals 344 can carry large currents.

[0123] FIG. 3A shows an example of a packaged switch 247dA. In FIG. 3A, switch 304dA includes an IGBT electrically connected in parallel with a diode D. Each collector terminal of the IGBT and each cathode terminal of the diode may have one or more conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of the die substrate, for example. For purposes of explanation, each collector terminal of the IGBT and each cathode terminal of the diode will have only one conductive pad unless otherwise noted. Each emitter terminal of the IGBT may have multiple conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of a respective pedestal or to a flat surface of a single pedestal. Each anode terminal of the diode may have a pad with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of the pedestal. In other versions, the flat surfaces of the emitter and anode terminal pads may be directly connected (e.g., sintered) to a flat surface of the die clip.

[0124] 3A may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surfaces of the emitter and anode terminal pads may be directly connected (e.g., sintered) to the first flat end face of the pedestal. A second flat surface at the opposite end of the pedestal (i.e., the second flat end face) may be directly connected (e.g., sintered) to the flat surface of the die clip 372. The pad surface connections (e.g., sintered connections) enable thermal and electrical transmission.

[0125] The connector lead 288g may be electrically connected to the gate terminal g of the IGBT. Although not shown in FIG. 3A , the switch module 376A may include a strap attached to the same surface of the die substrate 360 ​​to which the collector terminal c and cathode terminal pads are connected. The strap may be electrically insulated from the die substrate 360. One or more bond wires may electrically connect the strap to the gate terminal g pad. For purposes of explanation, each IGBT in this disclosure has only one gate terminal pad unless otherwise noted. The connector lead 288g may be electrically connected to the strap. The end of the connector lead 288g may be directly connected (e.g., soldered) to the strap. Alternatively, one or more bond wires may electrically connect the strap to the end of the connector lead 288g.

[0126] FIG. 3B is an example of a packaged switch 247dB. In FIG. 3B, switch 304dB includes four n-channel MOSFETs connected in parallel. Each drain terminal of the MOSFETs may have one or more conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of the die substrate, for example. For purposes of explanation, each drain terminal in this disclosure will have only one conductive pad unless otherwise specified. Each source terminal of the MOSFETs may have multiple conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of each pedestal or to a flat surface of one pedestal, for example. In another version, the flat surface of the source terminal pads may be directly connected (e.g., sintered) to a flat surface of the die clip.

[0127] In FIG. 3B, the flat surfaces of the pads for the drain terminals d1-d4 may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surfaces of the pads for the source terminals s1-s4 may be directly connected (e.g., sintered) to the first flat end faces of the respective pedestals. The second flat surfaces (i.e., the second flat end faces) at the opposite ends of the pedestals may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. A connector lead 288g may be electrically connected to the gate terminal of each MOSFET. For purposes of explanation, each MOSFET in this disclosure has only one gate terminal pad unless otherwise noted. Although not shown in FIG. 3B, the switch module 376B may include a strap attached to the same surface of the die substrate 360 ​​to which the pads for the drain terminals d1-d4 are connected. The strap may be electrically insulated from the die substrate 360. One or more bond wires may electrically connect the straps to the pads of the gate terminals of each MOSFET. Connector leads 288g may be electrically connected to the straps. The ends of the connector leads 288g may be directly connected (e.g., soldered) to the straps. Alternatively, one or more bond wires may electrically connect the straps to the ends of the connector leads 288g.

[0128] In FIG. 3C, switch 304dC comprises a symmetric GTO thyristor. The cathode terminal of the symmetric GTO thyristor may have one or more conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to the flat surface of the die substrate, for example. For purposes of explanation, the cathode terminal of a symmetric GTO thyristor in this disclosure will have only one conductive pad unless otherwise noted. The anode terminal of the symmetric GTO thyristor may have one or more conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to the flat surface of a single pedestal. In other versions, the flat surface of the anode terminal pad may be directly connected (e.g., sintered) to the flat surface of the die clip.

[0129] 3C may be directly connected (e.g., sintered) to a flat surface of the die substrate 360, and the flat surface of the anode termination pad may be directly connected (e.g., sintered) to a first flat end face of the pedestal. A second flat surface at the opposite end of the pedestal may be directly electrically and thermally connected (e.g., sintered) to a flat surface of the die clip 372.

[0130] For purposes of explanation, each symmetric GTO thyristor in this disclosure has only one gate terminal pad unless otherwise noted. Connector lead 288g may be electrically connected to the gate terminal of the GTO thyristor. Although not shown in FIG. 3C , switch module 376C may include a strap attached to the same surface of die substrate 360 ​​to which the cathode terminal pad is connected. The strap may be electrically insulated from die substrate 360. One or more bond wires may electrically connect the strap to the gate terminal pad of the symmetric GTO thyristor. Connector lead 288g may be electrically connected to the strap. The end of connector lead 288g may be directly connected (e.g., soldered) to the strap. Alternatively, one or more bond wires may electrically connect the strap to the end of connector lead 288g.

[0131] In FIG. 3D , switch 304dD includes a TRIAC. The first current terminal Anode-1 of the TRIAC may have one or more conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of, for example, a die substrate. For purposes of explanation, each first current terminal Anode-1 in this disclosure has only one conductive pad unless otherwise noted. The second current terminal Anode-2 of the TRIAC may have one or more conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of a single pedestal. In one version, the flat surface of the Anode-2 pad may be electrically and thermally directly connected (e.g., sintered) to a flat surface of a die clip.

[0132] 3D may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surface of the anode-2 may be directly connected (e.g., sintered) to the first flat end face of the pedestal. The flat surface at the opposite end of the pedestal may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372.

[0133] For purposes of illustration, each TRIAC in this disclosure has only one gate terminal pad unless otherwise noted. Connector lead 288g may be electrically connected to the gate terminal pad of the TRIAC. Although not shown in FIG. 3D , switch module 376D may include a strap attached to the same surface of die substrate 360 ​​to which the anode-1 pad is connected. The strap may be electrically insulated from die substrate 360. One or more bond wires may electrically connect the strap to the gate terminal pad of the TRIAC. Connector lead 288g may be electrically connected to the strap. The end of connector lead 288g may be directly connected (e.g., soldered) to the strap. Alternatively, one or more bond wires may electrically connect the strap to the end of connector lead 288g.

[0134] FIG. 3E illustrates an example of a packaged switch 247qE. The switch 304qE includes four n-channel MOSFETs connected in parallel. The flat surfaces of the pads for the drain terminals d1-d4 may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surfaces of the pads for the source terminals s1-s4 may be directly connected (e.g., sintered) to the first flat end surface of the pedestal. The flat surface at the opposite end of the pedestal (i.e., the second flat end surface) may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. The connector lead 288g1 may be electrically connected to the gate terminals of the first pair of MOSFETs as shown, and the connector lead 288g2 may be electrically connected to the gate terminals of the other pair of MOSFETs. Although not shown in FIG. 3E, the switch module 376E may include first and second separate straps attached to the same surface of the die substrate 360 ​​to which the pads for the drain terminals d1-d4 are connected. The straps may be electrically insulated from the die substrate 360. One or more bond wires may electrically connect a first strap to the pads of the gate terminals of the first pair of MOSFETs shown, and one or more bond wires may electrically connect a second strap to the pads of the gate terminals of the other pair of MOSFETs. Connector lead 288g1 may be electrically connected to the first strap, and connector lead 288g2 may be electrically connected to the second strap. An end of connector lead 288g1 may be directly connected (e.g., soldered) to the first strap, and an end of connector lead 288g2 may be directly connected (e.g., soldered) to the second strap. Alternatively, one or more bond wires may electrically connect the first strap to the end of connector lead 288g1, and one or more bond wires may electrically connect the second strap to the end of connector lead 288g2.

[0135] FIG. 3F shows an example of a packaged switch 247qF. The switch 304qF includes three MOSFETs connected in parallel with an IGBT. The flat surfaces of the pads for the collector terminal c and the drain terminal d may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surfaces of the pads for the emitter terminal e and the source terminal s may be directly connected (e.g., sintered) to the first flat end surface of the pedestal. The flat surface at the opposite end of the pedestal (i.e., the second flat end surface) may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. The connector lead 288g1 may be electrically connected to the gate terminal g of the MOSFET, and the connector lead 288g2 may be electrically connected to the gate terminal g of the IGBT. Although not shown in FIG. 3F, the switch module 376F may include first and second separate straps attached to the same surface of the die substrate 360 ​​to which the pads for the drain terminal d and the collector terminal c are connected. The straps may be electrically insulated from the die substrate 360. One or more bond wires may electrically connect the first strap to the pad of the gate terminal of the IGBT as shown, and one or more bond wires may electrically connect the second strap to the pad of the gate terminal g of the MOSFET. A connector lead 288g1 may be electrically connected to the first strap, and a connector lead 288g2 may be electrically connected to the second strap. An end of the connector lead 288g1 may be directly connected (e.g., soldered) to the first strap, and an end of the connector lead 288g2 may be directly connected (e.g., soldered) to the second strap. Alternatively, one or more bond wires may electrically connect the first strap to an end of the connector lead 288g1, and one or more bond wires may electrically connect the second strap to an end of the connector lead 288g2.

[0136] FIG. 3G shows an example of a packaged switch 247qG including a BBJT. Each current terminal c / e of the BBJT may have multiple conductive pads with completely flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to the flat surface of the respective pedestal. The flat surface of the pad of the first current terminal c / e1 may be directly connected (e.g., sintered) to the first flat surface of each of the first pedestals, and the second flat surface on the opposite side of the first pedestal may be electrically and thermally directly connected (e.g., sintered) to the flat surface of the die substrate 360. The flat surface of the pad of the second current terminal c / e2 may be directly connected (e.g., sintered) to the first flat end face of each of the second pedestals. The flat surface on the opposite end of the second pedestal may be electrically and thermally directly connected (e.g., sintered) to the flat surface of the die clip 372.

[0137] Connector lead 288g1 may be electrically connected to base terminal b1 of the BBJT, and connector lead 288g2 may be electrically connected to base terminal b2. For purposes of illustration, each base terminal b of the BBJT of the present disclosure is assumed to have multiple base terminal pads unless otherwise noted. The base terminal pads on the BBJT are arranged in groups, and each group may have multiple linearly arranged base terminal pads, each with an exposed flat surface. For purposes of illustration, no dielectric or other material is present between the base terminal pads within a group of linearly arranged base terminal pads. Although not shown in FIG. 3G , switch module 376G may include a first signal frame having a surface electrically connected (e.g., soldered) to the surface of the pad of base terminal b1 and a second signal frame having a flat surface electrically connected (e.g., soldered) to the surface of the pad of base terminal b2. The signal frames may be electrically isolated from each other. Connector lead 288g1 may be electrically connected to a first signal frame, and connector lead 288g2 may be electrically connected to a second signal frame. An end of connector lead 288g1 may be directly connected (e.g., soldered) to the first signal frame, and an end of connector lead 288g2 may be directly connected (e.g., soldered) to the second signal frame. Alternatively, one or more bond wires may electrically connect the first signal frame to an end of connector lead 288g1, and one or more bond wires may electrically connect the second signal frame to an end of connector lead 288g2.

[0138] 3H shows an example of packaged switch 247ph. Switch 304ph includes a MOSFET connected in parallel with a BBJT. In alternatives to packaged switch 247ph, two or more MOSFETs may be electrically connected in parallel with the BBJT, and these combinations may be connected between die substrate 360 ​​and die clip 372.

[0139] 3H may be directly connected (e.g., sintered) to a first flat surface of the respective first pedestal, and a second flat surface opposite the first pedestal may be directly electrically and thermally connected (e.g., sintered) to a flat surface of the die substrate 360. The flat surface of the pad of the second current terminal c / e2 may be directly connected (e.g., sintered) to a first flat end face of the respective second pedestal. A flat surface at the opposite end of the second pedestal may be directly electrically and thermally connected (e.g., sintered) to a flat surface of the die clip 372. The connector lead 288g1 may be electrically connected to the base terminal b1 of the BBJT, and the connector lead 288g2 may be electrically connected to the base terminal b2. Although not shown in FIG. 3H , the switch module 376H may include a first signal frame having a surface electrically connected (e.g., soldered) to the surface of the pad of the base terminal b1 and a second signal frame having a flat surface electrically connected (e.g., soldered) to the surface of the pad of the base terminal b2. The signal frames may be electrically insulated from each other. The connector lead 288g1 may be electrically connected to the first signal frame, and the connector lead 288g2 may be electrically connected to the second signal frame. An end of the connector lead 288g1 may be directly connected (e.g., soldered) to the first signal frame, and an end of the connector lead 288g2 may be directly connected (e.g., soldered) to the second signal frame. Alternatively, one or more bond wires may electrically connect the first signal frame to the end of connector lead 288g1, and one or more bond wires may electrically connect the second signal frame to the end of connector lead 288g2.

[0140] In FIG. 3H , the flat surface of the pad for the drain terminal d may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surface of the pad for the source terminal s may be directly connected (e.g., sintered) to the first flat end face of the pedestal. The flat surface at the opposite end of the pedestal (i.e., the second flat end face) may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. A connector lead 288c may be electrically connected to the gate terminal pad of the MOSFET. Although not shown in FIG. 3H , the switch module 376H may include a strap attached to the same surface of the die substrate 360 ​​to which the pad for the drain terminal d is connected. The strap may be electrically insulated from the die substrate 360. One or more bond wires may electrically connect the strap to the pad for the gate terminal. The connector lead 288c may be electrically connected to the strap. An end of the connector lead 288c may be directly connected (e.g., soldered) to the strap. Alternatively, one or more bond wires may electrically connect the strap to the end of connector lead 288c.

[0141] FIG. 3I shows an example of a packaged switch 247qI that may be bidirectional. The switch 304qI includes first and second groups of RB-IGBTs connected in anti-parallel. Each group of RB-IGBTs includes two RB-IGBTs connected in parallel. In alternative versions, the RB-IGBTs may be replaced with NPT-IGBTs or BJTs. Each collector terminal c1 of the first group of RB-IGBTs and each collector terminal c2 of the second group of RB-IGBTs may have one conductive pad with a completely flat surface. Each emitter terminal e1 of the first group of RB-IGBTs and each emitter terminal e2 of the second group of RB-IGBTs may have a conductive pad with a completely flat surface. The flat surfaces of the pads of collector terminals c1-1 and c1-2 may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the surfaces of the pads of collector terminals c2-1 and c2-2 may be directly connected (e.g., sintered) to the flat surface of the die clip 372. The flat surfaces of the pads of each emitter terminal e may be directly connected (e.g., sintered) to a first flat end face of the pedestal. The flat surfaces of the opposite ends of the pedestals connected to the pads of emitter terminals e2-1 and e2-2 may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surfaces of the opposite ends of the pedestals connected to the pads of emitter terminals e1-1 and e1-2 may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. Connector lead 288g1 may be electrically connected to gate terminal g2, and connector lead 288g2 may be electrically connected to gate terminal g1. Although not shown in FIG. 3I, switch module 376I may include a first strap attached to the same surface of die substrate 360 ​​to which pads for collector terminal c1 and emitter terminal e2 are connected, and a second strap attached to the same surface of die clip 372 to which pads for collector terminal c2 and emitter terminal e1 are connected. The first and second straps may be electrically insulated from die substrate 360 ​​and die clip 372, respectively.One or more bond wires may electrically connect the first strap to the pad of the gate terminal g2, and one or more bond wires may electrically connect the second strap to the pad of the gate terminal g1. A connector lead 288g1 may be electrically connected to the first strap, and a connector lead 288g2 may be electrically connected to the second strap. An end of the connector lead 288g1 may be directly connected (e.g., soldered) to the first strap, and an end of the connector lead 288g2 may be directly connected (e.g., soldered) to the second strap. Alternatively, one or more bond wires may electrically connect the first strap to an end of the connector lead 288g1, and one or more bond wires may electrically connect the second strap to an end of the connector lead 288g2.

[0142] FIG. 3J shows an example of a packaged switch 247qJ that can be bidirectional. In FIG. 3J, switch 304qJ includes first and second groups of MOSFETs connected back-to-back. Each group includes four MOSFETs. Each source terminal s of the MOSFETs may have a completely flat conductive pad. Each drain terminal d of the MOSFETs may have a completely flat conductive pad. The flat surfaces of the pads of drain terminals d1 and d2 may be directly connected (e.g., sintered) to the flat surfaces of the die substrate 360 ​​and die clip 372, respectively. The flat surfaces of the pads of source terminal s1 may be directly connected (e.g., sintered) to the first flat end surface of the respective pedestal. The flat surfaces at the opposite end of the pedestal may be directly electrically and thermally connected (e.g., sintered) to the flat surfaces of the pads of the respective source terminal s2. Connector lead 288g1 may be electrically connected to gate terminal g1, and connector lead 288g2 may be electrically connected to gate terminal g2. Although not shown in FIG. 3J , the switch module 376J may include first and second separate straps attached to the die substrate 360 ​​and the die clip 372, respectively. The first strap may be attached to the same surface of the die substrate 360 ​​to which the pad for the drain terminal d1 is connected, and the second strap may be attached to the same surface of the die clip 372 to which the pad for the drain terminal d2 is connected. The first and second straps may be electrically isolated from each other and from the die substrate 360 ​​and the die clip 372. One or more bond wires may electrically connect the first strap to the pad for the gate terminal g1, and one or more bond wires may electrically connect the second strap to the pad for the second gate terminal g2. A connector lead 288g1 may be electrically connected to the first strap, and a connector lead 288g2 may be electrically connected to the second strap. The end of connector lead 288g1 may be directly connected (eg, soldered) to a first strap, and the end of connector lead 288g2 may be directly connected (eg, soldered) to a second strap.Alternatively, one or more bond wires may electrically connect the first strap to the end of connector lead 288g1, and one or more bond wires may electrically connect the second strap to the end of connector lead 288g2.

[0143] FIG. 3K shows an example of a packaged switch 247pK that may be bidirectional. In addition to the components of the packaged switch 247qJ of FIG. 3J, the packaged switch 247pK of FIG. 3K includes a paddle 361 and a connector lead 288c. The paddle 361 is shown symbolically. Although not shown, the paddle 361 has first and second flat surfaces that face each other. In FIG. 3K, the switch 304pK includes first and second groups of MOSFETs connected back-to-back. Each group includes four MOSFETs connected in parallel. Each source terminal s of the MOSFETs may have a completely flat conductive pad. Each drain terminal d of the MOSFETs may have a completely flat conductive pad. The flat surfaces of the pads of the drain terminals d1 and d2 may be directly connected (e.g., sintered) to the flat surfaces of the die substrate 360 ​​and the die clip 372, respectively. The flat surface of the pad of the source terminal s1 may be directly connected (e.g., sintered) to the first flat end face of the respective first pedestal. The flat surface at the opposite end of the first pedestal may be electrically and thermally directly connected (e.g., sintered) to the first flat surface of the paddle 361. The flat surface of the pad of the source terminal s2 may be directly connected (e.g., sintered) to the first flat end face of the respective second pedestal. The flat surface at the opposite end of the second pedestal may be electrically and thermally directly connected (e.g., sintered) to the second flat surface of the paddle 361. The connector lead 288g1 may be electrically connected to the gate terminal g1, and the connector lead 288g2 may be electrically connected to the gate terminal g2. Although not shown in FIG. 3K, the switch module 376K may include first and second separate straps attached to the die substrate 360 ​​and the die clip 372, respectively. The first strap may be attached to the same surface of the die substrate 360 ​​to which the pad of the drain terminal d1 is connected, and the second strap may be attached to the same surface of the die clip 372 to which the pad of the drain terminal d2 is connected. The first and second straps may be electrically isolated from each other and from the die substrate 360 ​​and the die clip 372 .One or more bond wires may electrically connect the first strap to the pad of the gate terminal g1, and one or more bond wires may electrically connect the second strap to the pad of the second gate terminal g2. Connector lead 288g1 may be electrically connected to the first strap, and connector lead 288g2 may be electrically connected to the second strap. An end of connector lead 288g1 may be directly connected (e.g., welded) to the first strap, and an end of connector lead 288g2 may be directly connected (e.g., welded) to the second strap. Alternatively, one or more bond wires may electrically connect the first strap to the end of connector lead 288g1, and one or more bond wires may electrically connect the second strap to the end of connector lead 288g2. Connector lead 288c is electrically connected to paddle 361.

[0144] Figure 3L shows a packaged switch 247ql that can be bidirectional. Figure 3L shows a switch 304ql having four BBJTs connected in parallel. The flat surface of the pad of the first current terminal c / e1 of each BBJT may be directly connected (e.g., sintered) to the first flat surface of the respective first pedestal, and the opposite second flat surface of each BBJT's first pedestal may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die substrate 360. The flat surface of the pad of the second current terminal c / e2 may be directly connected (e.g., sintered) to the first flat end face of the respective second pedestal. The flat surface of the opposite end of the second pedestal may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372.

[0145] Connector lead 288g1 may be electrically connected to the base terminal b1 of each BBJT, and connector lead 288g2 may be electrically connected to the base terminal b2 of each BBJT. Although not shown in FIG. 3L, switch module 376L may include a first signal frame having a surface electrically connected (e.g., welded) to the surface of a pad of base terminal b1 of each BBJT, and a second signal frame having a flat surface electrically connected (e.g., welded) to the surface of a pad of base terminal b2 of each BBJT. The signal frames may be electrically insulated from each other. Connector lead 288g1 may be electrically connected to the first signal frame, and connector lead 288g2 may be electrically connected to the second signal frame. An end of connector lead 288g1 may be directly connected (e.g., welded) to the first signal frame, and an end of connector lead 288g2 may be directly connected (e.g., welded) to the second signal frame. Alternatively, one or more bond wires may electrically connect the first signal frame to the end of connector lead 288g1, and one or more bond wires may electrically connect the second signal frame to the end of connector lead 288g2.

[0146] FIG. 3O is an example of a packaged switch 247dO. In FIG. 3O, switch 304dO includes four IGBTs connected in parallel. Each collector terminal of the IGBT may have one or more conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of the die substrate, for example. For purposes of explanation, each collector terminal in this disclosure has only one conductive pad unless otherwise noted. Each emitter terminal of the IGBT may have multiple conductive pads with perfectly flat surfaces that can be electrically and thermally directly connected (e.g., sintered) to a flat surface of a respective pedestal or to a flat surface of a single pedestal, for example. In another version, the flat surfaces of the emitter terminal pads may be directly connected (e.g., sintered) to a flat surface of the die clip.

[0147] In FIG. 3O, the flat surfaces of the pads for the collector terminals c1-c4 may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surfaces of the pads for the emitter terminals e1-e4 may be directly connected (e.g., sintered) to the first flat end surface of the pedestal. The second flat end surface at the opposite end of the pedestal (i.e., the second flat end surface) may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. A connector lead 288g may be electrically connected to the gate terminal of each IGBT. For purposes of explanation, each IGBT in this disclosure has only one gate terminal pad unless otherwise noted. Although not shown in FIG. 3O, the switch module 376O may include a strap attached to the same surface of the die substrate 360 ​​to which the pads for the collector terminals c1-c4 are connected. The strap may be electrically insulated from the die substrate 360. One or more bond wires may electrically connect the straps to the pads of the gate terminals of each IGBT. Connector leads 288g may be electrically connected to the straps. The ends of the connector leads 288g may be directly connected (e.g., welded) to the straps. Alternatively, one or more bond wires may electrically connect the straps to the ends of the connector leads 288g.

[0148] FIG. 3P illustrates an example of a packaged switch 247qP. The switch 304qP includes two MOSFETs connected in parallel with two IGBTs. The flat surfaces of the pads for the collector terminal c and the drain terminal d may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surfaces of the pads for the emitter terminal e and the source terminal s may be directly connected (e.g., sintered) to the first flat end surface of the pedestal. The flat surface at the opposite end of the pedestal (i.e., the second flat end surface) may be directly electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. The connector lead 288g1 may be electrically connected to the gate terminal g of the IGBT, and the connector lead 288g2 may be electrically connected to the gate terminal g of the MOSFET. Although not shown in FIG. 3P, the switch module 376P may include first and second separate straps attached to the same surface of the die substrate 360 ​​to which the pads for the drain terminal d and the collector terminal c are connected. The straps may be electrically insulated from the die substrate 360. One or more bond wires may electrically connect the first strap to the pad of the gate terminal of the illustrated IGBT, and one or more bond wires may electrically connect the second strap to the pad of the gate terminal g of the MOSFET. Connector lead 288g1 may be electrically connected to the first strap, and connector lead 288g2 may be electrically connected to the second strap. An end of connector lead 288g1 may be directly connected (e.g., welded) to the first strap, and an end of connector lead 288g2 may be directly connected (e.g., welded) to the second strap. Alternatively, one or more bond wires may electrically connect the first strap to the end of connector lead 288g1, and one or more bond wires may electrically connect the second strap to the end of connector lead 288g2. The packaged switch 304qP should not be limited to two MOSFETs connected in parallel with two IGBTs.In alternative versions, three or four MOSFETs may be connected in parallel with two IGBTs, three or four IGBTs may be connected in parallel with two MOSFETs, three MOSFETs may be connected in parallel with three IGBTs, and four MOSFETs may be connected in parallel with four IGBTs. To accommodate these alternative versions of packaged switch 304qP, the size (i.e., length and width) of die substrate 360 ​​and die clip 372 must be increased.

[0149] Example of a packaged diode 245 2E-1 through 2E-3, Figures 3M and 3N show an example of a packaged diode 245 from a side view. The case (e.g., case 249) is shown transparent in Figures 3M and 3N to allow a better understanding of the packaged diode's components, their interactions, and their relative positions.

[0150] The example packaged diode 245 shown in Figures 3M and 3N includes diode modules 378M and 378N, respectively. Each diode module includes a power stack, which includes one or more diodes D disposed in electrical and thermal connection between a die substrate 360 ​​and a die clip 372, all of which are symbolically shown. Die substrate terminals 230 and die clip terminals 344 are also symbolically shown. The surfaces of the die substrate terminals 230 and die clip terminals 344 are completely flat and may be located below, above, or flush with the respective surfaces of the case 249. The diode module components, including the die substrate 360 ​​and die clip 372, may vary in size, shape, composition, etc. between the packaged diodes 245 of Figures 3M and 3N.

[0151] Although not shown in Figures 3M and 3N, each power stack may include one or more pedestals, each of which may have completely flat, opposing first and second end faces. The first flat end face of each of the one or more pedestals may be electrically and thermally connected (e.g., sintered) to a flat surface of a current terminal pad of a respective diode D. The second flat end face of each of the one or more pedestals may be electrically and thermally connected (e.g., sintered) to a flat surface of the die substrate 360 ​​or die clip 372 opposite the side having the die substrate terminal 230 or die clip terminal 344. In an alternative version, the power stacks of Figures 3M and 3N do not use pedestals, and the current terminals are directly connected (e.g., sintered) to the flat surfaces of the die clip 372 and die substrate 360, respectively.

[0152] Figures 3M and 3N show the relative positions of the components. The die substrate 360, one or more diodes D, and die clip 372 may be stacked as shown. Current can be transmitted between the die clip terminal 344 and the die substrate terminal 230 through the one or more diodes D. Diode modules 376M and 376N may include connector leads 288ds and 288dc, although for simplicity, neither are shown in Figures 3M and 3N. In many packaged diode versions, connector leads 288ds and 288dc are unnecessary and are omitted.

[0153] Die substrate 360 ​​and die clip 372 can conduct large currents (e.g., 1, 5, 10, 50, 200, 400 amperes, or more) to and from packaged diode 245 via die substrate terminals 230 and die clip terminals 344, respectively. Diodes generate heat. Die substrate 360 ​​and die clip 372 can conduct large amounts of heat generated by one or more diodes D to the exterior of packaged diode 245 via die substrate terminals 230 and die clip terminals 344, respectively.

[0154] 3M and 3N show examples of packaged diodes 245 that can be cooled via the die substrate terminal and the die clip terminal, respectively. In FIGS. 3M and 3N, each cathode terminal of one or more diodes D may have one or more completely flat conductive pads. Each anode terminal of one or more diodes D may have one or more completely flat conductive pads. The flat surface of the pad of the cathode terminal may be directly connected (e.g., sintered) to the flat surface of the die substrate 360, and the flat surface of the pad of the anode terminal may be directly connected (e.g., sintered) to the first flat end face of the respective pedestal. The flat surface of the opposite end of the pedestal (i.e., the second flat end face) may be electrically and thermally connected (e.g., sintered) to the flat surface of the die clip 372. Alternatively, the flat surface of the pad of the anode terminal may be directly connected (e.g., sintered) to the flat surface of the die clip 372.

[0155] Power Stack Terminal Example A power stack is formed by electrically and thermally connecting transistors and / or diodes between the die clip and the die substrate. The first current terminal (e.g., collector terminal, drain terminal, cathode terminal, etc.) pad of each transistor and / or diode may be sintered to the die substrate (or die clip) using a layer of highly conductive sintered material including silver, copper, etc. No dielectric exists between the transistor and / or diode and the die substrate terminal of the connected die substrate (or the die clip terminal of the connected die clip). The second current terminal (e.g., emitter terminal, source terminal, anode terminal, etc.) pad of each transistor and / or diode may be sintered to the die clip (or die substrate) via a layer of highly conductive sintered material including silver, copper, etc. No dielectric exists between the transistor and / or diode and the die clip terminal of the connected die clip (or the die substrate terminal of the die substrate). Therefore, no dielectric should exist between the die substrate terminal and the die clip terminal in a power stack.

[0156] The die substrate terminals and die clip terminals may have rectangular flat surfaces exposed through the case, for example, for connection to a bus bar. The dimensions (e.g., width and length) of the exposed terminals are configured to transmit a large amount of current and heat. The die substrate terminals may be parallel to and opposite (i.e., 180 degrees from) at least one flat surface of the die substrate to which a first current terminal (e.g., collector terminal, drain terminal, etc.) pad is sintered. The die clip terminals may be parallel to and opposite (i.e., 180 degrees from) at least one flat surface of the die clip to which a second current terminal (e.g., collector terminal, drain terminal, etc.) pad is sintered.

[0157] 2A-1 through 2E-3 may be electrically connected to one or more first current terminals (e.g., drains) and one or more second current terminals (e.g., sources) of one or more transistors in packaged switches 247p, 247q, 247s, and 247d, respectively. Alternatively, die substrate terminal 230 and die clip terminal 344 may be electrically connected to one or more first current terminals (e.g., cathodes) and one or more second current terminals (e.g., anodes) of diodes in packaged diode 245, respectively.

[0158] The die substrate terminals and die clip terminals may be configured for direct electrical and / or thermal connection to a device. The die substrate terminals 230 or die clip terminals 344 may be electrically and / or thermally connected to a heat sink, a bus bar, or the surface of a bus bar that also functions as a heat sink. For example, the die substrate terminals 230 or die clip terminals 344 may have a V+ terminal and be electrically and / or thermally connected to the flat surface of a “V+ bus bar” that is electrically connectable to the V+ terminal of a battery, fuel cell, DC / DC converter, etc. The die substrate terminals 230 or die clip terminals 344 may have a V− terminal and be electrically and / or thermally connected to a “V− bus bar” that is electrically connectable to the V− terminal of a battery, fuel cell, DC / DC converter, etc. The die substrate terminals 230 or die clip terminals 344 may have AC terminals and be electrically and / or thermally connected to an AC bus bar, also known as a “phase bus bar,” that is electrically connectable to the stator winding W of a motor, the inductor L of a filter, or the terminals of other devices. The heat sink or bus bar may have a flat surface that can be press-fit, welded, sintered, or otherwise connected to a flat surface of the die substrate terminal 230 or the die clip terminal 344, thereby forming an electrical and thermal connection between the two. A press-fit or soldered connection can reduce or eliminate problems due to differences in thermal expansion coefficients, as described below.

[0159] Busbars can have a variety of configurations depending on the design of the power converter in which they are used. Busbars may be assembled from several components. Typically, busbars are metallic elements that distribute high currents (e.g., 10, 20, 50, 100, 200, 400, 800 amperes, or more). The material composition (e.g., copper, aluminum, etc.) and cross-sectional area of ​​the busbar or its elements determine the maximum allowable current and parasitic parameters. Busbars with larger cross-sectional areas have smaller parasitic parameters, such as parasitic inductance, which affect voltage overshoots (also known as voltage spikes). The inductance of the disclosed busbars may be 1.0, 0.8, 0.6, 0.4 nH, or less, between the busbar terminals (e.g., V+, V-, or phase busbar terminals) and the die substrate terminals or die clip terminals of the packaged switch to which the busbar is directly connected.

[0160] The heat sink or bus bar may have one or more channels. The channels may be open at both ends of the heat sink or bus bar. Cooling air may enter the bus bar or heat sink through a first open end of the channel and exit the heat sink or bus bar through a second open end of the channel. The channels may be open at only one end of the heat sink or bus bar. A channel open at one or both ends may house a heat pipe. A typical heat pipe may have a phase change material and a wick inside a sealed tube made of metal such as copper or aluminum. The sealed tube may have a cross section that is circular, oval, square, rectangular, or the like. One or more layers of a thermally conductive dielectric such as aluminum nitride or beryllium oxide may be formed on all or part of the inner and / or outer surfaces of the heat pipe. The dielectric layer on the outer surface may electrically insulate the heat pipe from the heat sink or bus bar in which it is housed, or from the metal heat fin to which it is attached. In another example, there may be no dielectric between the heat pipe and the heat sink or bus bar it is housed in. In this alternative version, the outer surface of the metal heat pipe may be electrically and thermally connected to the heat sink or bus bar it is housed in and the metal heat fins to which it is attached.

[0161] In general, heat sinks or bus bars may be formed (e.g., extruded, 3D printed, cast, etc.) in whole or in part from a conductive metal such as copper or aluminum, and may have a variety of shapes, sizes, and dimensions (e.g., length, width, height, etc.) to suit different design purposes. Heat sinks or bus bars that also function as heat sinks may be formed by casting aluminum, copper, or other materials around heat pipes. Casting is a process in which liquid metal is poured into a mold that has a negative impression (i.e., a three-dimensional negative image) of the intended shape. A bare heat pipe or a heat pipe fully or partially coated with a thin layer of dielectric material may be placed in the mold before the liquid metal is poured. In other words, the bus bar may be cast around the heat pipe. Heat sinks or bus bars that also function as heat sinks may be formed by sandwiching a bare, fully, or partially dielectric-coated heat pipe between two metal halves, positioning them in aligned grooves, and then joining (e.g., soldering, sintering, brazing, etc.) the two metal halves. The two halves may be formed by extrusion, 3D printing, casting, etc. Before joining the halves, a thin layer of thermal paste (also known as thermal compound, thermal grease, thermal interface material (TIM), thermal gel, heat paste, heat sink compound, heat sink paste, or CPU grease) may be applied to the outer surface of the heat pipe to eliminate voids or spaces at the interface between the heat pipe and the heat sink or bus bar that also functions as the heat sink, and form a better thermal bond. In yet another version, the heat sink or bus bar containing the bare, fully, or partially coated heat pipe may be heated to reflow the metal of the heat sink or bus bar, eliminating voids or spaces at the interface between the heat pipe and the heat sink or bus bar, and forming a better thermal bond.

[0162] The busbar may not include heat pipes. The metal busbar may include channels that are open at both ends of the busbar. Cooling air may enter the busbar through a first open end of the channel and exit the busbar through a second open end. A busbar with open air channels (hereinafter referred to as an air-cooled busbar) may be extruded from a metal such as copper or aluminum and have a square or rectangular cross-sectional shape with four sidewalls connected at right angles to each other. Metal heat fins having opposing flat surfaces may be integrally connected to and extend between the inner flat surfaces of the opposing sidewalls. The heat fins may extend between opposing first and second ends of the extruded air-cooled busbar. The heat fins may define channels through which air flows through the extruded air-cooled busbar. The airflow may cool the heat fins. The channels at the first and second open ends may be in fluid communication with respective first and second air manifolds. The die substrate terminals 230 or die clip terminals 344 of the packaged switch 247 or packaged diode 245 may be directly electrically and thermally connected (e.g., soldered, sintered, press-fit, etc.) to the outer flat surface of the wall or to opposing outer flat surfaces of multiple walls.

[0163] Examples of switch modules and diode modules 3A-3P, FIGS. 4A-1-4H illustrate an example switch module 376, an example diode module 378, and their components. Each example switch module 376 and diode module 378 includes a switch or diode sandwiched between a die substrate and a die clip.

[0164] FIG. 4A-1 shows top and side views of an example die substrate 360, connector leads 288ds, and connector leads 288g. The die substrate is formed (e.g., by stamping, cutting, sawing, dicing, etc.) from a thin (e.g., 0.7 mm to 1.5 mm) metal sheet, which may or may not be electroplated with silver. Alternatively, the die substrate can be formed (e.g., by stamping, cutting, sawing, dicing, etc.) from a thin (e.g., 0.7 mm to 1.5 mm) laminate sheet, as shown in FIG. 2H. An example die substrate 360 ​​and collector leads 288ds can be formed from a thin (e.g., 0.7 mm to 1.5 mm) laminate sheet, as shown in FIG. 2H. The connector leads 288ds can be integrally connected to the die substrate 360 ​​as shown. In another version, the connector leads 288ds can be formed separately and then attached (e.g., welded) to the die substrate 360. In yet another version, connector leads 288ds may not be connected to die substrate 360.

[0165] Die substrate 360 ​​comprises opposing, completely flat, and substantially equal-area surfaces, one of which is designated as 362, the other of which defines an example of die substrate terminal 230. Die substrate terminal 230 may be configured to be thermally and electrically connected to a planar surface of a device, such as a bus bar, as described below.

[0166] Die substrate 360 ​​may have a width wds of about 13.5 mm and a length lds of about 16.5 mm. Connector leads 288ds may have a width of about 1.2 mm and a length of about 20 mm. Connector leads 288g may have a width of about 1.2 mm and a length of about 18 mm. Bond area 367 provides a surface onto which bond wires can be wirebonded.

[0167] The current terminal (e.g., drain terminal, collector terminal, cathode terminal, etc.) pad surface of the transistor and / or diode may be electrically and thermally directly attached to surface 362 of die substrate 360. For example, the flat first current terminal (e.g., drain terminal, collector terminal, cathode terminal, anode 2 terminal, etc.) pad surface of switch 304 or diode D shown in Figures 3A-3F, 3H-3K, and 3M-3P may be electrically and thermally directly attached (e.g., sintered) to surface 362.

[0168] The size of the die substrate 360 ​​(i.e., widths wds and lengths lds) may depend on the number and / or type of transistors in the switch 304 connected to it. For example, assuming IGBT dies are larger in size than MOSFET dies, the area of ​​the surface 362 required to accommodate four BBJTs or four IGBTs connected in parallel may be larger than the area of ​​the surface 362 required to accommodate four MOSFETs connected in parallel, or the area required to accommodate four MOSFETs connected in parallel may be smaller than the area of ​​the surface 362 required to accommodate two MOSFETs and two IGBTs connected in parallel. For ease of explanation and illustration, the size (length and width) of the transistor die will be assumed to be equal regardless of transistor type, unless otherwise indicated.

[0169] FIG. 4A-2 shows the die substrate 360 ​​of FIG. 4A-1 after four transistors T1-T4 have been electrically and thermally attached to the surface 362. More specifically, the flat surfaces of the first current terminal (e.g., drain terminal, collector terminal, etc., not shown) pads of transistors T1-T4 may be sintered to the surface 362. A low-resistance path may exist between the die substrate terminal 230 and each first current terminal pad. Each die-substrate bond (e.g., a sintered bond, not shown) of FIG. 4A-2 connecting the first current terminal pad surface to the surface 362 may conduct 1, 2, 5, 10, 20, 50, 100, 200, 300, 750, 1500 watts or more of heat while simultaneously conducting 1, 5, 10, 50, 100, 200, 400 amperes or more of current. Each die-substrate bond may have a length and width approximately equal to the length and width of the respective first current terminal pad surface.

[0170] T1 through T4 may be the same type of transistor, or T1 through T4 may be a mixture of different types of transistors. For example, T1 through T4 may be MOSFETs, and the flat surfaces of the drain terminal pads of T1 through T4 may be sintered to surface 362. T1 through T4 may be IGBTs, and the flat surfaces of the collector terminal pads of T1 through T4 may be sintered to surface 362. In another example, T1 and T2 may be MOSFETs, and T3 and T4 may be IGBTs. In this version, the flat surfaces of the drain terminal pads of T1 and T2 may be sintered to surface 362, and the flat surfaces of the collector terminal pads of T3 and T4 may be sintered to surface 362. In another version, one of the transistors (e.g., T1) may be replaced with a diode, and the other three transistors (e.g., T2 through T4) may be IGBTs. In this version, the flat surfaces of the collector terminal pads of the three IGBTs and the flat surfaces of the cathode terminal pads of the diodes may be sintered to surface 362. In yet another version, transistors T1 and T2 may be replaced with diodes, and T3 and T4 may be IGBTs. In this version, the flat surfaces of the collector terminal pads of the IGBTs and diodes may be sintered to surface 362.

[0171] Each of transistors T1-T4 may include a pair of second current terminal (e.g., source terminal, emitter terminal, etc.) pads, although it is understood that a transistor may have fewer or more than one pair of second current terminal pads. Each second current terminal pad may have a flat surface. An example of a flat surface 395 of a second current terminal pad is shown. Each of transistors T1-T4 includes a control terminal (e.g., gate terminal) pad having a flat surface. An example of a surface 384 of a control terminal pad is shown. Pads are not shown in the side view of FIG. 4A-2.

[0172] FIG. 4A-2 also shows examples of gate strap 364, bond wire 365, and bond wire 366. Gate strap 364 may be formed of a conductive metal such as copper and attached to surface 362 via an electrically insulating material (not shown), thereby electrically isolating gate strap 364 from die substrate 360. Connector lead 288g may be electrically connected to gate strap 364 via bond wire 365. Multiple bond wires 366 of approximately equal length may electrically connect gate strap 364 to respective surfaces 384 of the control terminal pads. Each bond wire 366 may be wire-bonded to strap 364 at a location on strap 364 approximately equidistant from the point on strap 364 to which bond wire 365 is wire-bonded. Those skilled in the art will understand that bond wires 366-3 and 366-4 would be unnecessary if transistors T3 and T4 were replaced with diodes. In an alternative version, the ends of the extended length connector leads 288g may be attached (e.g., welded) to straps 364. In yet another alternative version, the ends of the extended length connector leads 288g may be attached to surface 362 via an electrically insulating layer, thereby electrically isolating the extended length connector leads 288g from the die substrate 360. Multiple bond wires of approximately equal length may electrically connect the extended length connector leads 288g to respective surfaces 384 of the control terminal pads.

[0173] 4A-3 shows the structure of FIG. 4A-2 after an exemplary pedestal 1104 has been electrically and thermally attached (e.g., sintered) directly to the surface 395 of each of the second current terminal pads of transistors T1-T4. The pedestal, including pedestal 1104, may be formed from a thin (e.g., 1.0 mm to 1.2 mm) laminate sheet as shown in FIG. 2H. Pedestal 1104 may be approximately 1.65 mm wide and approximately 2.8 mm long.

[0174] The pedestal may have first and second flat end faces that face each other. Only the flat first end face 1101 is shown in FIG. 4A-3. The flat end faces of the pedestal, such as pedestal 1104, may have the same size and shape. The second flat end face of pedestal 1104 may be directly electrically and thermally attached (e.g., sintered) to the flat surface 395 of each second current terminal pad. The second flat end faces of pedestal 1104 may have substantially the same shape and size as, but slightly smaller than, the flat surface 395 of each second current terminal pad to which they are electrically and thermally attached (e.g., approximately rectangular) and size (e.g., approximately 2.8 mm × 1.65 mm). This may ensure that pedestal 1104 does not contact transistors T1-T4 outside the area occupied by the second current terminal (e.g., source terminal) pad. The second flat end faces of the pedestal may distribute mechanical stress more evenly. A pedestal, such as pedestal 1104, may reduce the current flux through source terminal pad surface 395 compared to the current flux (i.e., current density) through a small area on the source terminal pad surface connected to a bond wire. Each second joint (e.g., a sintered joint) connecting second current terminal pad surface 395 to the second flat end surface of pedestal 1104, and each pedestal 1104, may conduct 1, 2, 5, 10, 20, 50, 100, 200, 350, 800 watts or more of heat while simultaneously conducting 1, 5, 10, 20, 50, 100, 200, 400 amperes or more of current. Each of these second joints may have a length and width approximately equal to the length and width of the respective second flat end surface of pedestal 1104. The first flat end surfaces of the pedestals, such as surface 1101 in FIG. 4A-3, may be positioned in a common plane for attachment to the flat surface of, for example, a die clip. Pedestals such as pedestal 1104 in the power stack may have different thicknesses between their flat end faces to accommodate transistors having current terminal pad surfaces with different heights measured relative to surface 362, and the first end faces of the pedestals may be arranged in a common plane so as to be electrically and thermally attached to the flat surface of, for example, a die clip.

[0175] The transistors and / or diodes can be electrically and thermally connected to the die clip. Figures 4A-4 show top and side views of an example die clip 372 and an example connector lead 288dc. The die clip 372 can be formed (e.g., by stamping, cutting, sawing, dicing, etc.) from a thin (e.g., 0.7 mm to 1.5 mm) metal or metal composite sheet. Alternatively, the die clip 372 can be formed (e.g., by stamping, cutting, sawing, dicing, etc.) from a thin (e.g., 0.7 mm to 1.5 mm) laminate sheet as shown in Figure 2H. Unless otherwise noted, the die clip 372 is formed from a thin copper sheet. The die clip 372 can include an outer layer of an electroplated sintering-facilitating material (e.g., silver) to facilitate attachment to a pedestal, for example. The connector lead 288dc can be integrally connected to the die clip 372 as shown. In another version, the connector lead 288dc may be formed separately and then attached (e.g., welded) to the die clip 372. In yet another version, the connector lead 288dc may not be connected to the die clip 372.

[0176] Die clip 372 includes opposing, substantially equal-area, substantially flat surfaces 344 and 375. Surfaces 344 and 375 may be completely flat. Surface 344 defines an example die clip terminal 344 and may be configured to be thermally and electrically connected to a flat surface of a device, such as a bus bar, as described below. Surface 375 may be electrically and thermally attached (e.g., sintered) directly to a pedestal, current terminal pad, or the like.

[0177] In one version, the die clip 372 may have a width wdc of approximately 13.0 mm and a length ldc of approximately 16.0 mm. The connector leads 288dc may have a width of approximately 1.2 mm and a length of approximately 20 mm. As with the die substrate, the size of the die clip 372 may need to be adjusted depending on the number and / or type of transistors in the switch 304 connected to it. For example, the area of ​​the surface 375 required to accommodate a switch having four IGBTs connected in parallel or four BBJTs connected in parallel may be larger or smaller than the area of ​​the surface 375 required to accommodate a switch having four MOSFETs connected in parallel. Also, the area required to accommodate a switch having four MOSFETs connected in parallel may be smaller than the area 375 required to accommodate a switch having two MOSFETs and two IGBTs connected in parallel, assuming the IGBT die is larger than the MOSFET die. The area of ​​surface 375 required to accommodate a switch with two IGBTs and two diodes connected in parallel may be larger or smaller than the area of ​​surface 375 required to accommodate a switch with three MOSFETs and one IGBT connected in parallel.

[0178] A surface of a component, such as a pedestal including pedestal 1104, can be electrically and thermally directly attached to a flat surface of the die clip. For example, a first flat end surface of the pedestal, such as surface 1101, can be electrically and thermally directly connected (e.g., sintered) to surface 375. In some versions, flat surfaces of current terminal pads of transistors and / or diodes can be electrically and thermally directly connected (e.g., sintered) to surface 375. For example, the flat pad surface of the drain terminal d2 shown in FIG. 3J or 3K can be sintered to surface 375 of a die clip 372 formed from a thin (e.g., 0.7 mm to 1.5 mm) laminate sheet as shown in FIG. 2H. The width wdc and / or length ldc dimensions can be increased or decreased depending on the number of transistors connected in parallel or anti-parallel to the die clip 372.

[0179] 4A-5 shows top and side views of the structure of FIG. 4A-3 after the flat surface 375 of the die clip 372 has been electrically and thermally attached (e.g., sintered) directly to the flat surface 1101 of the pedestal 1104. Each die clip joint (e.g., sintered joint) connecting a first flat surface of the pedestal, such as surface 1101, to surface 375 can conduct 1, 2, 5, 10, 20, 50, 100, 300, 800 watts or more of heat while simultaneously conducting 1, 5, 10, 20, 50, 100, 200, 400 amperes or more of current. Each die clip joint can have a length and width approximately equal to the length and width of a respective first flat end face of the pedestal, such as surface 1101. A low-resistance path can exist between the die clip terminal 344 and each second current terminal pad, such as pad 395.

[0180] If T1-T4 take the form of MOSFETs, the structure shown in FIG. 4A-5 can be a version of switch module 376B shown in FIG. 3B. If T1-T4 take the form of IGBTs, the structure shown in FIG. 4A-5 can be a version of switch module 376O shown in FIG. 3O. After die clip 372 is electrically and thermally attached to base 1104, a case can be formed around the switch module of FIG. 4A-5, for example, using transfer molding, to produce the example packaged switch 247s shown in FIGS. 2C-1-2C-3. Alternatively, a case can be formed around the switch module of FIG. 4A-5, for example, using transfer molding, to produce the example packaged switch 247dB or 247dO shown in FIGS. 3B and 3O, respectively, which are examples of packaged switch 247d shown in FIGS. 2D-1-2D-3. Prior to case formation, some or all of the connector leads 288 can be bent to place the case exterior ends of the connector leads 288 in a common plane, as shown in Figures 2C-3 and 2D-3. In alternative versions, connector leads 288ds and / or 288dc can be omitted to create alternative versions of packaged switch 247d.

[0181] In FIG. 4A-3, the pedestals 1104 are electrically and thermally directly connected (e.g., sintered) to each second current terminal pad. The pedestals can be connected to adjacent second current terminal pads in the transistor. FIG. 4A-6 shows the structure of FIG. 4A-2, with exemplary pedestals 1108 electrically and thermally directly attached (e.g., sintered) to each pair of second terminals. The pedestals 1108 are longer than the pedestals 1104 and may be formed from a thin (e.g., 1.0 mm to 1.2 mm) laminate sheet as shown in FIG. 2H, although it is understood that the pedestals 1108 should not be limited thereto. The pedestals 1108 may be approximately 2.8 mm wide and approximately 3.3 mm long.

[0182] Like pedestal 1104, pedestal 1108 may have first and second flat end faces that face each other. Only first flat end face 1107 is shown in FIGS. 4A-6 . Each second flat end face is directly electrically and thermally attached (e.g., sintered) to the flat surface 395 of an adjacent second current terminal pad in a respective transistor. The flat second end face (not shown) of each pedestal 1108 may have a shape (e.g., substantially rectangular) and size (e.g., approximately 2.8 mm × 3.3 mm) that is generally the same as the shape and size of the surface 395 of an adjacent second current terminal pad in a transistor and the area that separates the adjacent second current terminal pads. Each second joint (e.g., a sintered joint) connecting a pair of adjacent second current terminal pad surfaces 395 to the flat second end face of the pedestal 1108, and each pedestal 1108, may conduct 10, 20, 50, 100, 300, 800, 1000 watts or more of heat while simultaneously conducting 10, 20, 50, 100, 200, 400 amps or more of current. Each second joint may have a length and width approximately equal to the length and width of the flat second end face of the pedestal 1108.

[0183] FIG. 4A-7 shows top and side views of the structure of FIG. 4A-6 after the flat surface 375 of the die clip 372 of FIG. 4A-4 has been electrically and thermally attached (e.g., sintered) directly to the flat surface 1107 of the base 1108. A low-resistance path can exist between the die clip terminal 344 and each second current terminal pad 395. Each die clip joint (e.g., a sintered joint) connecting surface 1107 to surface 375 can conduct 10, 20, 50, 100, 300, 800, 1000 watts or more of heat while simultaneously conducting 10, 20, 50, 100, 200, 400 amps or more of current. Each die clip joint (not shown) in FIG. 4A-7 can have a length and width approximately equal to the length and width of the respective first flat end surface 1107.

[0184] If T1-T4 take the form of MOSFETs, the structure shown in FIG. 4A-7 can be a version of switch module 376B shown in FIG. 3B. If T1-T4 take the form of IGBTs, the structure shown in FIG. 4A-7 can be a version of switch module 376O shown in FIG. 3O. After die clip 372 is attached, a case may be formed around the switch module of FIG. 4A-7, for example, using transfer molding, to produce an example of packaged switch 247s shown in FIGS. 2C-1-2C-3. Alternatively, a case may be formed around the switch module of FIG. 4A-7, for example, using transfer molding, to produce an example of packaged switch 247dB or 247dO shown in FIGS. 3B and 3O, respectively, which is an example of packaged switch 247d shown in FIGS. 2D-1-2D-3. Prior to case formation, some or all of the connector leads 288 can be bent to place the case exterior ends of the connector leads 288 in a common plane, as shown in Figures 2C-3 and 2D-3. In an alternative version, connector leads 288ds and / or 288dc are not included, thereby creating an alternative version of packaged switch 247d.

[0185] In yet another version of the switch module 376B, the pedestal may be integrally formed with the bridge (i.e., an integral bridge). Figure 4A-8 illustrates the structure of Figure 4A-2, where each of the exemplary integral bridges 371 is directly electrically and thermally attached (e.g., sintered) to the second current terminal of the respective adjacent transistor. The integral bridges 371 may have a generally flat surface 383 that is approximately 10.8 mm long and 2.8 mm wide.

[0186] The integral bridge 371 may be formed (e.g., cut) from a thin (e.g., 0.7 mm to 1.5 mm) laminate sheet as shown in FIG. 2H. The integral pedestals 1110 may be created by cutting grooves into the laminate sheet. The flat end surface of each integral pedestal 1110 may have the same size and shape as the flat end surface 1107 of the pedestal 1108. Each flat end surface may be directly electrically and thermally attached (e.g., sintered) to the surface 395 of an adjacent current terminal pad in the respective transistor. Each second joint (e.g., sintered joint) connecting a pair of adjacent second current terminal pad surfaces 395 to the flat second end surface of the integral pedestal 1110, and each pedestal 1110, may conduct 10, 20, 50, 100, 300, 700 watts or more of heat while simultaneously conducting 10, 20, 50, 100, 200, 400 amperes or more of current. Each of these second joints may have a length and width approximately equal to the length and width of the flat second end face of the base 1110. Each bridge 371 may have a flat surface 383 that can be sintered to the flat surface of the die clip 372.

[0187] The grooves of the integral bridge 371 may extend across its entire width and span between pairs of adjacent transistors. For example, the groove of the integral bridge 371-1 may span between transistors T1 and T2, and the groove of the integral bridge 371-2 may span between transistors T3 and T4. The grooves may be formed by cutting into the laminated sheet using, for example, a rotary burr (also called a die grinder bit) of a rotary tool. The grooves may be deep enough to allow liquid molding compound to flow freely between the pedestals 1110 when the flat end faces of the pedestals 1110 are electrically and thermally attached (e.g., sintered) directly to the second current terminal (e.g., source terminal) pad surfaces 395 of the respective transistors. The grooves may be rectangular with three sides (i.e., rectangular grooves) as shown in side views in FIGS. 4A-8, or they may be inverted V-shaped with two sides (i.e., V-grooves). In a V-groove, the cross-sectional width of the pedestals 1110 widens toward the bridge side to which they are integrally connected. V-grooves may provide better heat dissipation compared to rectangular grooves, but rectangular grooves may allow liquid mold compound to flow better between the pedestals 1110 during transfer molding.

[0188] FIG. 4A-9 shows a top view and a side view of the structure of FIG. 4A-8 after the die clip 372 of FIG. 4A-4 has been added. Specifically, FIG. 4A-9 shows the structure after the flat surface 375 of the die clip 372 has been electrically and thermally attached (e.g., sintered) directly to the flat surface 383 of the integral bridge 371. A low-resistance path can exist between the die clip terminal 344 and each second current terminal pad 395. Each die clip joint (e.g., a sintered joint) connecting surface 383 to surface 375 can conduct 10, 20, 50, 100, 300, 700, 1400 watts or more of heat while simultaneously conducting 10, 20, 50, 100, 200, 400, 800 amperes or more of current. Each die clip joint (not shown) in FIG. 4A-9 can have a length and width approximately equal to the length and width of the respective surface 383.

[0189] If T1-T4 are MOSFETs, the structure shown in FIG. 4A-9 can be a version of switch module 376B shown in FIG. 3B. If T1-T4 are IGBTs, the structure shown in FIG. 4A-9 can be a version of switch module 376O shown in FIG. 3O. After die clip 372 is electrically and thermally attached to integral bridge 371, a case can be formed around the switch module of FIG. 4A-9, for example, using transfer molding, to produce an example of packaged switch 247s shown in FIGS. 2C-1-2C-3. Alternatively, a case can be formed around the switch module of FIG. 4A-9, for example, using transfer molding, to produce a version of packaged switch 247dB or 247dO shown in FIGS. 3B and 3O, respectively, which is an example of packaged switch 247d shown in FIGS. 2D-1-2D-3. Prior to case formation, some or all of the connector leads 288 can be bent to place the case exterior ends of the connector leads 288 in a common plane, as shown in Figures 2C-3 and 2D-3. In an alternative version, connector leads 288ds and / or 288dc are not included, thereby creating an alternative version of packaged switch 247d.

[0190] Returning to FIG. 4A-2, all control terminals of transistors T1-T4 are electrically connected to gate strap 364. In an alternative version, the control terminals of the transistors in the switch may be electrically connected to individual gate straps. FIG. 4B-1 shows the structure of FIG. 4A-2 in which gate strap 364 is replaced with a pair of gate straps 359-1 and 359-2, which are attached to the surface 362 of the die substrate 360 ​​via an electrically insulating material (not shown). Gate straps 359-1 and 359-2 may be narrower than gate strap 364. Otherwise, gate straps 359-1 and 359-2 are substantially identical to gate strap 364. FIG. 4B-1 also shows that connector lead 288g of FIG. 4A-2 has been replaced with a pair of connector leads 288g-1 and 288g-2. Connector lead 288g is substantially identical to connector leads 288g-1 and 288g-2.

[0191] Bond wires 366-1 and 366-2 of approximately the same length may electrically connect gate strap 359-1 (or extended length connector lead 288g-1) to the surface 384 of the control terminal (e.g., gate terminal) pad of transistors T1 and T2, respectively. Bond wires 366-3 and 366-4 of approximately the same length may electrically connect gate strap 359-2 (or extended length connector lead 288g-2) to the surface 384 of the control terminal pad of transistors T3 and T4, respectively. Connector leads 288g-1 and 288g-2 are electrically connected to gate straps 359-1 and 359-2, respectively, by bond wires 365-1 and 365-2, respectively. In an alternative version, the ends of extended length connector leads 288g-1 and 288g-2 may be connected (e.g., welded) to gate straps 359-1 and 359-2, respectively. In yet another version, the ends of extensions 288g-1 and 288g-2 may be attached to surface 362 via an electrically insulating material. In this alternative version, bond wires 366-1 and 366-2 of approximately the same length may electrically connect extended connector lead 288g-1 to surface 384 of the control terminal pads of transistors T1 and T2, and bond wires 366-3 and 366-4 of approximately the same length may electrically connect extended connector lead 288g-2 to surface 384 of the control terminal pads of transistors T3 and T4.

[0192] Transistors T1-T4 in FIG. 4B-1 may be the same type, or transistors T1-T4 may be a mix of different types. For example, T1-T4 may all be MOSFETs or IGBTs. T1 and T2 may be MOSFETs and T3 and T4 may be IGBTs, or T1 and T3 may be MOSFETs and T2 and T4 may be IGBTs. In a mixed-transistor version, the flat surfaces of the first current terminal (e.g., drain and collector) pads of T1-T4 may be electrically and thermally attached (e.g., sintered) directly to surface 362. In yet another version, one of the transistors (e.g., T1) may be replaced with a diode, and transistors T2-T4 may take the form of IGBTs. In yet another version, transistors T1 and T3 may be replaced with diodes, and transistors T2 and T4 may be IGBTs. In a mixed IGBT / diode version, the flat collector terminal pad of the IGBT and the flat cathode terminal pad of the diode may be electrically and thermally attached (e.g., sintered) directly to surface 362. Of course, the diode does not require bond wires 366. There may be a low resistance path between the die substrate terminal 230 and the drain or collector terminal pad of each transistor T or diode.

[0193] FIG. 4B-2 shows the structure of FIG. 4B-1 after the pedestal 1108 has been electrically and thermally directly attached (e.g., sintered) to the adjacent surface 395 within each transistor. FIG. 4B-3 shows top and side views of the structure of FIG. 4B-2 after the die clip 372 of FIG. 4A-4 has been added. Specifically, in FIG. 4B-3, the flat surface 375 of the die clip 372 is electrically and thermally directly attached (e.g., sintered) to the flat surface 1107 of the pedestal 1108. A low-resistance path may exist between the die clip terminal 344 and each second current terminal pad 395. Transistors T1 and T2 may be controlled by a first control terminal signal received via connector lead 288g-1, and transistors T3 and T4 may be independently controlled by a separate second control terminal signal received via connector lead 288g-2.

[0194] If transistors T1-T4 are MOSFETs, the structure shown in FIG. 4B-3 can be a version of switch module 376E in FIG. 3E. If transistors T1 and T2 are IGBTs and T3 and T4 are MOSFETs, the structure shown in FIG. 4B-3 can be a version of switch module 376P in FIG. 3P. In another version, transistors T1-T4 may each be an IGBT. After die clip 372 is attached to base 1108, a case may be formed around the switch module shown in FIG. 4B-3, using, for example, transfer molding, to produce a version of packaged switch 247qE or 247qP shown in FIGS. 3E and 3P, respectively, which is an example of packaged switch 247q shown in FIGS. 2B-1-2B-3. Prior to case formation, some or all of connector leads 288 may be bent to position the case exterior ends of connector leads 288 in a common plane, as shown in FIG. 2B-3. In an alternative version, connector leads 288ds and / or 288dc are not included, creating an alternative version of packaged switch 247q.

[0195] FIG. 4B-4 illustrates the structure of FIG. 4B-2, with bond wires 366-1 through 366-3 electrically connecting gate strap 359-1 to control terminal pad surface 384 of transistors T1 through T3, and bond wire 366-4 electrically connecting gate strap 359-2 to control terminal pad surface 384 of transistor T4. Transistors T1 through T4 in FIG. 4B-4 may be the same type, or transistors T1 through T4 may be a mix of different types. Transistors T1 through T3 may be controlled by a control terminal signal received via connector lead 288g-1, and transistor T4 may be independently controlled by a separate control terminal signal received via connector lead 288g-2. FIG. 4B-5 illustrates top and side views of the structure of FIG. 4B-4 after the die clip 372 of FIG. 4A-4 has been added. Specifically, FIG. 4B-5 shows the structure after the flat surface 375 of the die clip 372 has been electrically and thermally attached (e.g., sintered) directly to the flat surface 1107 of the base 1108. If transistors T1-T3 are MOSFETs and transistor T4 is an IGBT, the structure shown in FIG. 4B-5 can be a version of the switch module 376F of FIG. 3F. After the die clip 372 is electrically and thermally attached to the base 1108, a case can be formed around the switch module shown in FIG. 4B-5, using, for example, transfer molding, to produce an example of the packaged switch 247qF shown in FIG. 3F, which is an example of the packaged switch 247q shown in FIGS. 2B-1-2B-3. Prior to case formation, some or all of the connector leads 288 can be bent to position the case exterior ends of the connector leads 288 in a common plane, as shown in FIG. 2B-3. In an alternative version, connector leads 288ds and / or 288dc are not included, creating an alternative version of packaged switch 247q.

[0196] The surfaces of the transistor current terminal pads may be electrically and thermally attached to the die clip. FIG. 4C-1 shows the die clip 372 after the surfaces of the first current terminal (e.g., drain, collector, etc.) pads of transistors T5-T8 have been electrically and thermally attached (e.g., sintered) directly to surface 375. A low-resistance path may exist between the die clip terminal 344 and each first current terminal pad of transistors T5-T8. Each joint (e.g., a sintered joint) connecting the first current terminal pad surface to surface 375 in FIG. 4C-1 may conduct 10, 20, 50, 100, 200, 300, 750 watts or more of heat while simultaneously carrying 50, 100, 200, 400 amps or more of current. Each of these joints (not shown in FIG. 4C-1) may have a length and width approximately equal to the length and width of the respective first current terminal pad surface. In FIG. 4C-1, die clip 372 may be formed from a thin (e.g., 0.7 mm to 1.5 mm) laminate sheet, as shown in FIG. 2H. T5-T8 may be the same type of transistor, or T5-T8 may be a mix of different types of transistors. For example, T5 and T6 may be MOSFETs, and T7 and T8 may be IGBTs. In this version, the flat surfaces of the drain terminal pads of T5 and T6 and the flat surfaces of the collector terminal pads of T7 and T8 may be sintered to surface 375. In another version, one of the transistors (e.g., T5) may be replaced with a diode, and transistors T6-T8 may take the form of IGBTs. In this version, the flat collector terminal pads of the three IGBTs and the flat cathode terminal pads of the diodes may be electrically and thermally attached (e.g., sintered) directly to surface 375.

[0197] Each of transistors T5-T8 may include a pair of second current terminal (e.g., source terminal, emitter terminal, etc.) pads. Each second current terminal pad may have a flat surface 395. Each of transistors T5-T8 includes a control terminal (e.g., gate terminal) pad having a flat surface 384. The pads are not shown in the side view of FIG. 4C-1.

[0198] FIG. 4C-1 also shows an example of a gate strap 364-2, bond wires 365-2, and bond wires 366. The gate strap 364-2 may be formed of a conductive metal such as copper and may be attached to the surface 375 via an electrically insulating layer (not shown), thereby electrically insulating the gate strap 364-2 from the die clip 372. A connector lead 288g-2 may be electrically connected to the gate strap 364-2 via the bond wires 365-2. Multiple bond wires 366 of approximately equal length may electrically connect the gate strap 364-2 to the surface 384 of each of the control terminal pads. Each bond wire 366 may be wire bonded to the strap 364-2 at a location on the strap 364-2 approximately equidistant from the point on the strap 364-2 to which the bond wire 365-2 is wire bonded. In an alternative version, the end of the extended length connector lead 288g-2 may be attached (e.g., welded) to the strap 364-2. In yet another alternative version, the ends of the extended length connector leads 288g-2 may be attached to the surface 375 via an electrically insulating layer, thereby electrically insulating the extended length connector leads 288g-2 from the die clip 372. Multiple bond wires of approximately equal length may electrically connect the extended length connector leads 288g-2 to respective surfaces 384 of the control terminal pads.

[0199] 4A-6, FIG. 4C-2 shows the structure of FIG. 4C-1 after the second current terminals of transistors T5-T8 have been thermally and electrically attached (e.g., sintered) directly to respective end surfaces 1107 of pedestal 1108, pedestal 1108 has been thermally and electrically attached (e.g., sintered) directly to respective second terminals of transistors T1-T4, and transistors T1-T4 have been electrically connected back-to-back with transistors T5-T8, respectively. For illustrative purposes, gate strap 364, bond wire 365, and surface region 367 of FIG. 4A-6 have been relabeled gate strap 364-1, bond wire 365-1, and surface region 367-1 in FIG. 4C-2. Transistors T1-T4 may be controlled by a first control terminal signal received via connector lead 288g-1, and transistors T5-T8 may be independently controlled by a separate second control terminal signal received via connector lead 288g-2.

[0200] If T1-T8 are MOSFETs, the structure shown in FIG. 4C-2 can be a version of switch module 376J in FIG. 3J. In this case, the source terminals of MOSFETs T1-T4 are electrically connected to the source terminals of MOSFETs T5-T8, respectively. After die clip 372 is attached to base 1108, a case may be formed around the switch module shown in FIG. 4C-2, for example, using transfer molding, to produce an example of packaged switch 247qJ shown in FIG. 3J, which is an example of packaged switch 247q shown in FIGS. 2B-1-2B-3. Prior to case formation, some or all of connector leads 288 can be bent to position the case exterior ends of connector leads 288 in a common plane, as shown in FIG. 2B-3. In an alternative version, connector leads 288ds and / or 288dc are not included, thereby producing an alternative version of packaged switch 247q.

[0201] FIG. 4D-1 shows the structure of FIG. 4C-1 after the second flat end surface of the pedestal 1108 has been electrically and thermally attached to the adjacent second current terminal (e.g., source terminal, emitter terminal, anode terminal, etc.) pad surface 395 of each transistor T5-T8.

[0202] The switch module may include a paddle disposed between the die substrate and the die clip. The paddle may be formed (e.g., by stamping, cutting, sawing, dicing, etc.) from a thin (e.g., 0.7 mm to 1.5 mm) metal or composite sheet. Alternatively, the paddle may be formed (e.g., by stamping, cutting, sawing, dicing, etc.) from a thin (e.g., 0.7 mm to 1.5 mm) laminate sheet as shown in FIG. 2H. FIG. 4D-2 shows top and side views of an example paddle 361 and an example connector lead 288c. The paddle 361 may be formed from a thin (e.g., 0.7 mm to 1.5 mm) copper sheet. The paddle 361 may have the same size, shape, and composition as the die clip 372 shown in FIG. 4A-4, except that a connector lead (e.g., connector lead 288c) is positioned intermediate the paddle 361 as shown. The connector lead 288c may be integrally connected to the paddle 361 as shown. In another version, the connector lead 288c may be electrically and thermally attached (eg, welded) to the paddle.

[0203] Paddle 361 has substantially flat surfaces 332 and 334 facing each other, although these surfaces may be completely flat. These surfaces may be electrically and thermally connected to the current terminal pad surfaces of the transistors. For example, flat surface 332 may be directly electrically and thermally attached (e.g., sintered) to a first flat end surface of a first pedestal, and a second flat end surface of the first pedestal may be directly electrically and thermally attached (e.g., sintered) to the second current terminals of each of the first group of transistors. Meanwhile, flat surface 344 may be directly electrically and thermally attached (e.g., sintered) to a first flat end surface of a second pedestal, and a second flat end surface of the second pedestal may be directly electrically and thermally attached (e.g., sintered) to the second current terminals of each of the second group of transistors. This electrically connects the second current terminals of the first group of transistors to each other and to the second current terminals of the second group of transistors, connecting the first group and the second group back-to-back.

[0204] Figure 4D-3 shows the paddle 361 of Figure 4D-2 after the paddle 361 has been thermally and electrically attached to the structure shown in Figures 4A-6 and 4D-1. Specifically, Figure 4D-3 shows the structure of Figures 4A-6 and 4D-1 after the end face 1107 of the pedestal 1108 of Figure 4A-6 has been electrically and thermally attached (e.g., sintered) directly to the flat surface 334 of the paddle 361, and after the end face 1107 of the pedestal 1108 of Figure 4D-1 has been electrically and thermally attached (e.g., sintered) directly to the flat surface 332 of the paddle 361. For illustrative purposes, the gate strap 364, bond wire 365, and surface region 367 of Figure 4A-6 have been relabeled as gate strap 364-1, bond wire 365-1, and surface region 367-1 in Figure 4D-3.

[0205] Transistors T1-T4 may be controlled by a first control terminal signal received via connector lead 288g-1, and transistors T5-T8 may be independently controlled by a separate second control terminal signal received via connector lead 288g-2.

[0206] If T1-T8 take the form of MOSFETs, the structure shown in FIG. 4D-3 can be a version of switch module 376K of FIG. 3K. After 361 is attached, a case may be formed around the switch module shown in FIG. 4D-3, using, for example, transfer molding, to produce an example of packaged switch 247p shown in FIGS. 2A-1-2A-3. Prior to case formation, some or all of connector leads 288 may be bent to position the case exterior ends of connector leads 288 in a common plane, as shown in FIG. 2A-3.

[0207] The switch may include transistors connected in anti-parallel. Figure 4E-1 shows the structure of Figure 4B-2 without strap 359-2, connector lead 288g-2, transistor T3, transistor T4, and bond wires 365-2, 366-3, and 366-4. Figure 4E-2 shows the structure of Figure 4D-1 without transistor T5, transistor T6, and bond wires 366-6 and 366-5. Figure 4E-3 shows the structures shown in Figures 4E-1 and 4E-2 after they have been thermally and electrically attached to one another (e.g., sintered). 4E-1 and 4E-2 after the end face 1107 of the pedestal 1108 of FIG. 4E-1 has been directly electrically and thermally attached (e.g., sintered) to the flat surface 375 of the die clip 372, and after the end face 1107 of the pedestal 1108 of FIG. 4E-2 has been directly electrically and thermally attached (e.g., sintered) to the flat surface 362 of the die substrate 360. Transistors T1 and T2 may be controlled by a first control terminal signal received via connector lead 288g-1, and transistors T7 and T8 may be independently controlled by a separate second control terminal signal received via connector lead 288g-2.

[0208] Transistors T1, T2, T7, and T8 of FIGS. 4E-1 through 4E-3 may block large reverse voltages (e.g., 5, 10, 50, 100, 200, 400, 800, 1600 V, or more) when off without breakdown. Each of transistors T1, T2, T7, and T8 of FIGS. 4E-1 through 4E-3 may be an RB-IGBT, an NPT-IGBT, a GTO thyristor, a BJT, or the like. For example, each of transistors T1, T2, T7, and T8 of FIGS. 4E-1 through 4E-3 may be an RB-IGBT, a GTO thyristor, an NPT-IGBT, or a BJT in which the flat collector terminal pad surfaces of T1 and T2 are sintered to flat surface 362 and the flat collector terminal pad surfaces of T7 and T8 are sintered to flat surface 375. 4E-1-4E-3 may be a mix of transistors. For example, transistors T1 and T2 may each be an RB-IGBT with a flat collector terminal pad surface sintered to planar surface 362, and transistors T7 and T8 may each be an NPT-IGBT with a flat collector terminal pad surface sintered to planar surface 375.

[0209] If each of transistors T1, T2, T7, and T8 in FIGS. 4E-1 through 4E-3 is an RB-IGBT, the structure shown in FIG. 4E-3 can be a version of switch module 376I shown in FIG. 3I. Alternatively, transistors T1, T2, T7, and T8 can be NPT-IGBTs or BJTs. Using, for example, transfer molding, a case can be formed around the structure shown in FIG. 4E-3 to produce an example of packaged switch 247qI shown in FIG. 3I, which is an example of packaged switch 247q shown in FIGS. 2B-1 through 2B-3. Prior to case formation, some or all of connector leads 288 can be bent to position the case exterior ends of connector leads 288 in a common plane, as shown in FIG. 2B-3. In an alternative version, connector leads 288ds and / or 288dc are not included, thereby producing an alternative version of packaged switch 247q.

[0210] The switch module may include other devices such as sensors and drivers. The switch module may include a PCB or DBC on which devices such as drivers and sensors are mounted. FIG. 4F-1 shows the structure of FIG. 4A-2, but replaces the strap 364 with a PCB 340, which includes traces 342. In an alternative version, the PCB 340 may be replaced with a DCB, which may allow for more heat conduction from the mounted device (e.g., driver) to the underlying die substrate 360. A temperature sensor (e.g., a thermistor) 348 is mounted on the PCB 340 and electrically connected to traces 342-1 and 342-3. A thermistor is a semiconductor resistor whose resistance is linearly dependent on temperature. The temperature sensor 348 can affect the voltage between traces 342-1 and 342-3, which depends on the temperature between transistors T2 and T4. Trace 342-2 is electrically connected to a metal pad 346. Bond wires 366 may be wire bonded to pads 346. One end of PCB 340 may be attached (e.g., glued) to surface 362 of die substrate 360. The other end of PCB 340 extends from die substrate 360. The ends of traces 342 may be electrically connected to conductors of a connector (not shown), which may be attached to a driver PCB or control PCB (not shown) that includes a microcontroller, drivers, voltage regulators, and / or other components.

[0211] FIG. 4F-2 shows the structure of FIG. 4F-1 after the surface of the pedestal 1108 has been electrically and thermally directly attached (e.g., sintered) to the surface 395 of the second current terminal (e.g., source terminal, emitter terminal, anode terminal, etc.) pad of the transistors T1-T4. The flat first surface 1107 of FIG. 4F-2 may be substantially disposed in a common plane to accommodate attachment of the die clip to the flat surface. FIG. 4F-3 shows a top view and a side view of the structure of FIG. 4F-2 after the die clip 372 of FIG. 4A-4 has been added. Specifically, FIG. 4F-3 shows the structure after the flat surface 375 of the die clip 372 has been electrically and thermally directly attached (e.g., sintered) to the flat surface 1107 of the pedestal 1108. After the die clip 372 is attached to the pedestal 1108, a case may be formed around the switch module of FIG. 4F-3, for example, using transfer molding. The resulting packaged switch can replace one, more, or all of the packaged switches 247d used in one, more, or all of the converters described below, with alternative versions not including connector leads 288ds and / or 288dc creating alternative versions of the packaged switch.

[0212] The example bidirectional packaged switch shown in Figures 3G and 3L includes a BBJT electrically and thermally connected (e.g., sintered) between the die substrate and the die clip. The bidirectional packaged switch shown in Figure 3G includes one BBJT. Referring to Figures 2F and 2G, Figure 4G-1 shows top and side views of an example BBJT 250, which includes example collector / emitter (c / e) terminal pads 262 and 264 on its top side and example collector / emitter (c / e) terminal pads 272 and 278 on its bottom side. The c / e pads 262 and 264 may have substantially flat surfaces 280 and 282, respectively, and the c / e pads 272 and 278 may have substantially flat surfaces 284 and 286, respectively. Surfaces 280 and 282 may be disposed in a common plane, and surfaces 284 and 286 may be disposed in another common plane. Planar surface 280 may be electrically and thermally directly connected (e.g., welded) to a planar surface of the respective pedestal, and planar surface 282 may be connected (e.g., welded) to a planar surface of a first signal frame. Similarly, planar surface 284 may be electrically and thermally directly connected (e.g., welded) to a planar surface of the respective pedestal, and planar surface 286 may be connected (e.g., welded) to a planar surface of a second signal frame.

[0213] The signal frame may be connected to the flat surface of the base terminal pad. FIG. 4G-2 shows top and side views of BBJT 250 with signal frames 377-1 and 377-2 connected to base terminal pad surfaces 282 and 286, respectively. Specifically, the flat surface of signal frame 377-1 is connected to flat surface 282 of base terminal pad 264 on the top side of BBJT 250, and the flat surface of signal frame 377-2 is connected to flat surface 286 of base terminal pad 278 on the bottom side of BBJT 250. Signal frame 377 may be formed (e.g., by cutting, stamping, dicing, etc.) from a thin (e.g., 1.0 mm to 2.0 mm) metal sheet such as copper. The signal frame can transmit a base control signal to the base terminal pad.

[0214] The pedestal may be connected to the flat surfaces of the c / e terminal pads. FIG. 4G-3 shows a top view of the structure shown in FIG. 4G-2 after the pedestal 1112 has been electrically and thermally attached (e.g., sintered) directly to the surfaces 280 and 284 of the c / e terminal pads on either side of the BBJT 250. FIG. 4G-4 shows a side view of the structure of FIG. 4G-3. FIG. 4G-5 shows a cross-sectional view of the structure of FIG. 4G-3 along line 3-3. The pedestal 1112 in FIG. 4G-3 is similar to the pedestal 1104 or 1108 shown in the previous figures, but the pedestal 1112 in FIG. 4G-3 is substantially longer. The pedestal 1112 may have opposing flat first and second surfaces. Only the first flat surface 1113 is shown in FIG. 4G-3. The second planar surface is electrically and thermally attached (e.g., sintered) directly to the planar surface 280 or 284 of the respective c / e terminal pad 262 or 272. The flat second end faces of the pedestal 1112 may have a shape (e.g., generally rectangular) and size that is generally similar to, but slightly smaller than, the shape and size of the generally planar surface 280 or 284 of the respective second current terminal pad 262 or 272 to which they are electrically and thermally attached. The flat first surface 1113 of FIG. 4G-3 may be disposed substantially in a common plane to accommodate attachment of a bridge or die clip to the planar surface.

[0215] The die clip and die substrate may be electrically and thermally attached (e.g., sintered) directly to the pedestal 1112 of the structure shown in FIG. 4G-3. FIG. 4G-6 shows a top view and a side view of the structure shown in FIG. 4G-3 after the die substrate 360 ​​of FIG. 4A-1 has been electrically and thermally attached (e.g., sintered) directly to the pedestal 1112 on the underside of the BBJT 250 as shown. More specifically, a first flat surface of the pedestal 1112 may be sintered to the surface 362 of the die substrate 360. FIG. 4G-6 also shows connector leads 288g-1 and 288g-2, which are electrically connected to signal frames 377-1 and 377-2, respectively, by bond wires 365-1 and 365-2, respectively. FIG. 4G-7 shows a top view and a side view of the structure shown in FIG. 4G-6 after the die clip 372 of FIG. 4A-4 has been electrically and thermally attached (e.g., sintered) directly to the pedestal 1112 on the top side of the BBJT 250 as shown. More specifically, a first flat surface of the pedestal 1112 may be sintered to the surface 375 of the die clip 372. In this version, the die substrate 360 ​​and the die clip 372 may be formed from a thin copper sheet.

[0216] The structure shown in FIG. 4G-7 is an example of the switch module 376G shown in FIG. 3G. Using, for example, transfer molding, a case may be formed around the structure shown in FIG. 4G-7 to produce an example of the packaged switch 247qG shown in FIG. 3G, which is an example of the packaged switch 247q of FIGS. 2B-1-2B-3. Prior to case formation, some or all of the connector leads 288 may be bent to position the case exterior ends of the connector leads 288 in a common plane, as shown in FIG. 2B-3. In an alternative version, the connector leads 288ds and / or 288dc are not connected to the die substrate 360 ​​and die clip 372, respectively.

[0217] The bidirectional packaged switch shown in FIG. 3L includes four BBJTs electrically and thermally connected (e.g., sintered) between die substrate 360 ​​and die clip 372. FIG. 4G-8 shows a top view of the four BBJTs 250. Signal frames 377e-1 and 377e-2 may be connected to the base terminal pad surfaces on the upper and lower sides of BBJTs 250-1 through 250-4, respectively. Specifically, the flat surface of signal frame 377e-1 is connected to the flat surface of the base terminal pads on the upper side of BBJTs 250-1 through 250-4, and the flat surface of signal frame 377e-2 is connected to the flat surface of the base terminal pads on the lower side of BBJTs 250-1 through 250-4. Signal frame 377e may be formed (e.g., by cutting, stamping, dicing, etc.) from a thin (e.g., 1.0 mm to 2.0 mm) metal sheet such as copper. The signal frame can carry a base control signal to the base terminal pad.

[0218] The pedestal may be connected to the flat surfaces of the c / e terminal pads on both sides of the BBJTs 250-1 to 250-4. In FIG. 4G-8, the flat second end surface of the pedestal 1112 may be directly electrically and thermally attached (e.g., sintered) to the surfaces of the respective c / e terminal pads on both sides of the BBJTs 250-1 to 250-4. The die clip and die substrate may be directly electrically and thermally attached (e.g., sintered) to the pedestal 1112 of the structure shown in FIG. 4G-8. FIGS. 4G-9 and 4G-10 show top and side views of the structure shown in FIG. 4G-8 after the die substrate 360 ​​of FIG. 4A-1 has been directly electrically and thermally attached (e.g., sintered) to the pedestal 1112 on the underside of the BBJTs 250-1 to 250-4. More specifically, first flat end surfaces 1113 of the pedestals 1112 on the undersides of the BBJTs 250-1 through 250-4 may be sintered to the surface 362 of the die substrate 360. FIG. 4G-9 also shows connector leads 288g-1 and 288g-2, which are electrically connected to signal frames 377e-1 and 377e-2, respectively, by bond wires 365-1 and 365-2, respectively. FIGS. 4G-11 and 4G-12 show side and top views of the structure shown in FIG. 4G-10 after the die clip 372 of FIG. 4A-4 has been electrically and thermally attached (e.g., sintered) directly to the pedestals 1112 on the top sides of the BBJTs 250-1 through 250-4. More specifically, first flat end surfaces 1113 of the pedestals 1112 on the upper surfaces of the BBJTs 250-1 to 250-4 may be sintered to the surface 375 of the die clip 372. In this version, the die substrate 360 ​​and the die clip 372 may be formed from thin copper sheets.

[0219] The structure shown in FIGS. 4G-11 and 4G-12 is an example of switch module 376L shown in FIG. 3L. Using, for example, transfer molding, a case may be formed around the structure shown in FIG. 4G-11 to produce an example of packaged switch 247ql shown in FIG. 3L, which is an example of packaged switch 247q shown in FIGS. 2B-1-2B-3. Prior to case formation, some or all of connector leads 288 may be bent to position the case exterior ends of connector leads 288 in a common plane, as shown in FIG. 2B-3. An alternative version of packaged switch 247q is produced by not including connector leads 288ds and / or 288dc.

[0220] 4H shows a top and side view of the example diode module 378N of FIG. 3N, which includes a pair of diodes D1 and D2 sandwiched between die clip 372 and die substrate 360. D1 and D2 can be the same type of diode, or D1 and D2 can be a mix of different types of diodes.

[0221] 4H shows diodes D1 and D2 after the flat surfaces of their first current terminal (e.g., cathode terminal, not shown) pads have been electrically and thermally attached (e.g., sintered) directly to surface 362. A low-resistance path can exist between die substrate terminal 230 and each first current terminal pad. In FIG. 4H, each die-substrate bond (e.g., sintered bond, not shown) connecting the first current terminal pad surface to surface 362 can conduct 10, 20, 50, 100, 200, 300, 750 watts or more of heat while simultaneously carrying 50, 100, 200, 400 amps or more of current. Each die-substrate bond can have a length and width approximately equal to the length and width of the respective first current terminal pad surface.

[0222] Each diode D1 and D2 may include a second current terminal (e.g., anode terminal, not shown) pad. Each second current terminal pad may have a flat surface. FIG. 4H shows a pedestal 1117, which may be generally similar to pedestal 1108 described above. Each pedestal 1117 may have opposing first and second flat end faces. The second flat end faces of pedestal 1117 may be electrically and thermally directly attached (e.g., sintered) to the respective flat surfaces of the second current terminal pads of diodes D1 and D2. The flat second end faces of pedestal 1117 may have a shape and size that is generally identical to, but slightly smaller than, the shape and size of the flat surfaces of the respective second current terminal pads to which they are electrically and thermally attached. Each second joint (e.g., a sintered joint) connecting the second current terminal pad surface to the second flat end face of the pedestal 1117, and each pedestal 1117, may conduct 10, 20, 50, 100, 200, 300, 600 watts or more of heat while simultaneously carrying 10, 20, 50, 100, 200, 400 amps or more of current. Each of these second joints may have a length and width approximately equal to the length and width of the respective second flat end face of the pedestal 1117.

[0223] 4H shows the flat surface 375 of the die clip 372 electrically and thermally attached (e.g., sintered) directly to the first flat end face of the pedestal 1117. Each die clip joint (e.g., sintered joint) connecting the first flat end face of the pedestal 1117 to the surface 375 may conduct 10, 20, 50, 100, 300 watts or more of heat while simultaneously carrying 10, 20, 50, 100, 200 amps or more of current. Each die clip joint may have a length and width approximately equal to the length and width of the respective first flat end face of the pedestal 1117. A low resistance path may exist between the die clip terminal 344 and each second current terminal pad of the diodes D1 and D2.

[0224] For example, a case may be formed around the example diode module 378 of FIG. 4H using transfer molding to produce the example packaged diode 245 shown in FIGS. 2E-1-2E-3. Prior to case formation, connector leads 288 may be positioned with their case exterior ends in a common plane, as shown in FIG. 2E-3. In an alternative version, a "connector leadless" version of packaged diode 245 is produced in which connector leads 288ds and 288dc are not connected to die substrate 360 ​​and die clip 372.

[0225] Power Converter Example Inverter 460iT The power converter (hereinafter also referred to as converter) of the present disclosure includes an inverter and a rectifier and has high power density. For example, the inverter or rectifier of the present disclosure can supply peak power of 200 kW or more in a very small volume.

[0226] 5A-1 and 5A-2 show the relevant components of an exemplary inverter 460iT from below and from the end, respectively. Some components shown in FIG. 5A-1 (e.g., packaged DC link capacitors 403 and 433-1) are not shown or are not fully shown in FIG. 5A-2 but are described below. Some components shown in FIG. 5A-2 (e.g., driver PCB 461i and control PCB 462i) are not shown or are not fully shown in FIG. 5A-1 but are described below.

[0227] Converters and other power systems of the present disclosure may use the packaged switches 247 and / or packaged diodes 245 described above. While the exemplary inverter 460iT is shown with packaged switch 247d, it is understood that in alternative versions, packaged switch 247d may be replaced with packaged switch 247p or packaged switch 247q. All packaged switches 247d of inverter 460iT may be identical. Packaged switches 247d of inverter 460iT may be packaged switches 247dA, 247dB, or 247dD of FIGS. 3A, 3B, and 3D, respectively.

[0228] A converter or other power system may use one or more bus bars to distribute current to the switch 304. The inverter 460iT includes exemplary V+ bus bar 417T, V- bus bar 412T, and phase bus bar 418T. Bus bars, such as the V+ bus bar 417T, V- bus bar 412T, and phase bus bar 418T, may also function as heat sinks to cool the switch 304, as described below. The case surface of the packaged switch 247, such as the packaged half switch 247d in FIG. 5A-1, may be thermally connected to the flat surfaces of the bus bars, such as the V+ bus bar 417T, V- bus bar 412T, and phase bus bar 418T.

[0229] A converter may have one or more phases. Inverter 460iT has three phases, a through c. Each phase in FIG. 5A-1 includes two packaged switches 247dH and 247dL electrically and thermally connected to a phase bus bar 418T, both of which are sandwiched between a V+ bus bar 417T and a V- bus bar 412T. Packaged switches 247dH and 247dL are also electrically and thermally connected to the V+ bus bar 417T and the V- bus bar 412T, respectively.

[0230] Volume in converters and other power systems may be saved by stacking packaged switches and bus bars. Figures 5A-1 and 5A-2 show packaged switch 247d, V+ bus bar 417T, phase bus bar 418T, and V- bus bar 412T arranged in line with each other.

[0231] 5A-1 may have die substrate terminals 230 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface or each flat surface of the V+ bus bar 417T and die clip terminals 344 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface of each phase bus bar 418Ta-418Tc, which may be electrically connected to the windings Wa-Wc, respectively. The packaged switch 247dL in FIG. 5A-1 may have die substrate terminals 230 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface of each phase bus bar 418Ta-418Tc and die clip terminals 344 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface of the V- bus bar 412T. The die substrate terminals 230 and die clip terminals 344 are located at the center of the surface of the bus bar and may be located near the edge of the bus bar (e.g., 4.0, 3.0, 2.0, 1.0 mm or less) proximate to the end of the evaporator end of the heat pipe described below.

[0232] Busbars, such as the V+ busbar 417T, V- busbar 412T, and phase busbar 418T in FIGS. 5A-1 and 5A-2, may have rectangular cross-sections. An example phase busbar 418T may have a height hTpb, width wTpb, and length of approximately 12 mm, 25 mm, and 20 mm, respectively. An example V+ busbar 417T and V- busbar 412T may have a height hT, width wT, and length of approximately 8 mm, 25 mm, and 70 mm, respectively. The busbars may have different shapes and dimensions to accommodate different converter designs.

[0233] Different materials expand at different rates when heated. For example, materials such as solder or silver sinter paste can be used to attach the die substrate terminals or die clip terminals to the busbar, but the attachment materials may crack when heated or cooled due to mismatched coefficients of thermal expansion (CTE). Mechanical structures (e.g., clamps) can press-fit the die substrate terminals 230 and die clip terminals 344 onto the respective flat surfaces of the busbar. The press-fit can reduce or eliminate problems associated with CTE mismatch. Ideally, the surfaces of the components being crimped together should be smooth to optimize electrical and thermal conduction between them. The addition of grease or a similar material can improve electrical and thermal conduction between the press-fit components.

[0234] Although not shown, the die substrate terminals 230 or die clip terminals 344 may be electrically and thermally connected to the flat surface of their respective busbar pedestals. The busbar pedestals are electrically and thermally connected to and extend from the busbar, or busbars that also function as heat sinks. The surface of the busbar pedestal may be slightly smaller than the surface of the terminals 230 or 344 to which they are connected. The terminals 230 or 344 may be flush with or slightly below the case surface of the packaged switch 247 or packaged diode 245 to which they are housed. Heat and / or current may be transferred between the terminals 230 or 344 and the connected busbar pedestal. While not required, applying a thin layer of thermally and / or electrically conductive grease or other material between the terminals 230 or 344 and the surface of the connected busbar pedestal may improve thermal and / or electrical conductivity during crimping.

[0235] The busbar or heat sink may include one or more channels through which cooling air can flow. Alternatively, the channels may house heat pipes. The channels may be rectangular, oval, square, etc. in cross section, and the heat pipes housed in the channels should have a similar cross-sectional shape. The busbar channels are assumed to be circular (i.e., round) in cross section, and the heat pipes they hold are also assumed to be circular in cross section, although it will be understood that the present disclosure is not limited in this regard. The heat pipes may have an outer diameter approximately equal to the diameter of the channel in which they are housed.

[0236] Each busbar within the converter may have one or multiple rows of channels. The V+ busbar 417T and the V- busbar 412T have a single row of channels 40, and the phase busbar 418T has two rows of channels 40. In alternative versions, the V+ busbar 417T and the V- busbar 412T may have multiple rows of channels 40. In alternative versions, the phase busbar 418T may have less than two rows or more than two rows of channels 40. All channels within the converter may be the same size (e.g., diameter). In alternative versions, channel dimensions may vary within a busbar or between busbars within the converter.

[0237] To improve heat transfer, the channels may be located adjacent to the surface of the busbar that is connected (e.g., sintered) to the die clip terminal or die substrate terminal, and the channels extend perpendicular to the long axis of the busbar.

[0238] Heat pipe example The heat pipes may be thermally connected to the bus bar or heat sink in which they are housed. The heat pipes may also be electrically connected to the bus bar or heat sink in which they are housed. If housed, the outer cylindrical surface of the heat pipe may be thermally connected to the cylindrical surface of the channel in the bus bar or heat sink. In some versions, a thermally conductive material (e.g., thermally conductive grease) may be used to improve thermal conduction between the heat pipe and the cylindrical surface of the channel in the bus bar or heat sink.

[0239] The heat pipe may include a "wick" and a "working" liquid within a sealed tube. A vacuum pump may be used to remove air from the tube before sealing. The tube may be made of a material compatible with the working liquid, such as copper for a water heat pipe or aluminum for an ammonia heat pipe. The amount of working liquid may be selected so that the heat pipe contains both vapor and liquid over the operating temperature range.

[0240] FIG. 5A-3 shows an exemplary heat pipe 522. The heat pipe 522a includes a wick 552 and a liquid, the combination of which is contained within a vacuum-sealed tube 550a made of a metal such as copper or aluminum. In FIG. 5A-3, a portion of the heat pipe 522a is cut away to reveal the exemplary wick 552 and working liquid. The wick may be attached directly to the inner wall of the heat pipe. FIG. 5A-3 also shows exemplary heat pipes 522b and 522c shown in cross section. The heat pipe 522b includes an exemplary grooved wick, and the heat pipe 522c includes an exemplary metal mesh wick structure.

[0241] Each heat pipe extends between an evaporator end and a condenser end. The evaporator end may be embedded within a channel of a busbar, such as the V+ busbar 417T, V- busbar 412T, or phase busbar 418Tc in FIG. 5A-1. The condenser end may be thermally attached to a heat sink, such as a metal heat fin, as described below.

[0242] The evaporator ends of the heat pipes may be thermally connected to a bus bar. The switch 304 is thermally and electrically connected to the bus bar. The evaporator ends of the heat pipes may extract heat generated by the switch 304 through the bus bar. The heat pipes may also be electrically connected to the bus bar.

[0243] The condenser end of the heat pipe may be thermally connected to heat fins made of metal or another highly thermally conductive material, such as sintered beryllium oxide. For illustrative purposes, the heat fins are made of metal. These heat fins can extract heat from the condenser end of the heat pipe. The heat pipe may also be electrically connected to the metal heat fins in some versions.

[0244] 5A-4 through 5A-7 show bottom, end, and top views of the inverter 460iT shown in FIGS. 5A-1 and 5A-2, with the heat pipes 522 housed within the channels 40. These figures show exemplary metal heat fins 520 and fans. Metal heat fins 520, such as heat fin 520T, have flat surfaces that face each other. A fan, such as fan 530, can force cooling air across the flat surfaces of the heat fins 520.

[0245] The evaporator ends of the heat pipes 522 may be thermally connected but electrically insulated from the bus bar channels 40 in which the heat pipes 522 are housed, and the condenser ends may be electrically and thermally connected (e.g., soldered) directly to the metal heat fins 520T. Electrical insulation of the evaporator ends may be provided by a thin dielectric layer formed on the outer cylindrical surface of the heat pipes.

[0246] All, a portion, or all of the outer surface of a heat pipe may be covered with a thin layer of dielectric material. The evaporator end of a heat pipe, such as heat pipe 522 of inverter 406iT, may be covered with a thin dielectric layer 536 (see, e.g., FIGS. 5A-3 and / or 5A-4) to electrically insulate the heat pipe from the bus bar in which it is housed, while the remainder of the heat pipe is largely bare. To improve heat transfer, a thin metallization layer, thermal grease, or thermal paste may be applied to the dielectric layer between the dielectric layer and the bus bar in which the heat pipe is embedded.

[0247] In another version, the evaporator end may be thermally and electrically connected directly (e.g., soldered) to a bus bar, such as bus bar 417T, 412T, or 418T, and the condenser end is thermally connected to, but electrically isolated from, heat fins 520, such as metal heat fins 520T. In this other version, electrical isolation is provided by a thin dielectric layer formed on the outer surface of the condenser end that connects to heat fins 520T, with the remainder of the heat pipe below the heat fins being bare.

[0248] In operation, the heat pipe utilizes a phase change. More specifically, heat generated by the switch 304 or another device, such as a diode, can be conducted to a liquid in the heat pipe at the evaporator end. This heat causes the liquid to evaporate, and the vapor can travel along the lumen of the heat pipe to the condenser end. At the condenser end, heat from the vapor is exchanged with a heat sink, such as the heat fins 520T, and the vapor can condense back into a liquid, which can then be absorbed by the wick. The condensed liquid travels back through the wick to the evaporator end, and the cycle continues.

[0249] The most commonly used fluids in heat pipes include water, ammonia, acetone, and methanol. In the moderate temperature range, water may be an ideal working fluid due to its high latent heat and boiling point. For low-temperature applications, ammonia, acetone, and methanol may be more suitable.

[0250] The performance of a heat pipe is primarily determined by the wick, which has multiple functions. First, it allows for the reverse flow of liquid from the condenser end to the evaporator end. Second, it allows for heat transfer to the liquid. Third, it provides space for the liquid / vapor phase change. Heat pipes are fabricated with various types of wick structures, such as sintered wicks, grooved wicks, and screen mesh wicks. Sintered wicks allow for high heat transfer and a wide operating angle. Figure 5A-3 shows a cross-sectional view of an exemplary heat pipe 522b with an exemplary grooved wick. The exemplary wick is "flower" shaped, with a ring of small cylindrical subchannels, which have approximately the same cross-section and are in fluid communication with a centrally located cylindrical subchannel, which may be larger in cross-section compared to the cylindrical subchannels within the ring. "Spoke" subchannels allow fluid communication between the cylindrical subchannels within the ring and the centrally located cylindrical subchannel. Each spoke subchannel may have any of a variety of cross-sectional shapes. In the illustrated version, each spoke subchannel has a generally rectangular cross-section, although square or circular cross-sections are also contemplated. Grooved wicks are lightweight and low-cost, but have limited operating angles and are often gravity-dependent. The example screen mesh wick shown in Figure 5A-3 combines features of both sintered and grooved wicks and may be preferable for some applications. The most common screen mesh may be constructed of woven copper mesh. Screen mesh wicks are made by wrapping metal cloth or mesh around a forming mandrel and then inserting it into a tube. Once in place, the mandrel is carefully removed, leaving the wrapped mesh. The mesh attempts to unwind, but tension against the inner wall of the tube holds the wick in place.

[0251] In FIGS. 5A-4 through 5A-7, the evaporator ends of the heat pipes 522 are housed within their respective channels 40 and thermally connected to the phase bus bar 418T, V- bus bar 412T, and V+ bus bar 417T. FIG. 5A-4 shows that each heat pipe 522 is electrically insulated from the phase bus bar 418T, V- bus bar 412T, or V+ bus bar 417T by a thin (e.g., 1.0, 0.5, 0.2, 0.1 mm, or less) dielectric material layer 536 (e.g., aluminum oxide, aluminum nitride, silicon nitride, beryllium oxide, etc.). In some versions, the dielectric layer should cover only the portion of the heat pipe 522 that is within the bus bar. A metal layer may be formed on the dielectric layer 536 to provide better electrical and / or thermal connection to the surface of the bus bar channel in which the heat pipe is housed. This allows for processes for connecting (e.g., soldering, sintering, brazing, welding, etc.) the heat pipes to the walls of the busbar channel in which they are housed. These connection processes can improve thermal and / or electrical conductivity between the heat pipes and the busbar.

[0252] The outer surface of the evaporator end of the heat pipe 522 may be connected to the surfaces of the channels 40 of the phase busbar 418T, V- busbar 412T, and V+ busbar 417T. Dielectric layer 536 may be the only dielectric in the thermal path between the switch 304 and the heat pipe. The bare outer surface of the condenser end of the heat pipe 522 may be directly thermally and electrically connected (e.g., soldered) to metal heat fins, such as heat fins 520T in FIGS. 5A-4 through 5A-7, which may be cooled by a fan, such as fan 530. While the figures show sets of three flat metal heat fins 520, it is understood that each set may have fewer or more metal heat fins. The metal heat fins 520 are not necessarily flat and may have shapes other than those shown. FIG. 5A-7 shows a view of the top heat fin 520T. In one version, the outer surface of heat pipe 522 is soldered directly to the cylindrical wall of a respective opening formed in a metal heat fin, such as heat fin 520T.

[0253] The dielectric layer should have a high dielectric strength (e.g., 1, 5, 10, 25, 50, 100 kV, or more). The dielectric layer 536 can be thin (e.g., 500.0, 300.0, 200.0, 100.0, 50.0, 20.0, 5.0, 3.0, 1.0 μm, or less). The thickness of the dielectric layer 536 affects the heat transfer to the heat pipe. The table below contains calculated heat transfer W for dielectric layer 536 of different materials and thicknesses. W is proportional to k·A·(T1-T2) / d, where k is the thermal conductivity, A is the area, ΔT=70 is the temperature difference across the dielectric layer, and d is the thickness (μm). For the calculated heat transfer W, assume a voltage of 4 kV is applied to the dielectric. [Table 1]

[0254] The dielectric layer 536 may be formed by spraying (e.g., plasma spraying or flame spraying) a dielectric material onto all or selected portions of the outer cylindrical surface of the heat pipe. The dielectric layer 536 may be formed by rolling all or selected portions of the heat pipe with a dielectric material (e.g., TIM). The dielectric layer 536 may be formed by CVD, PVD, coating (pad printing, brushing, dipping, electrodeposition (in the case of porcelain enamel or electrostatic painting), etc., and heating) onto all or selected portions of the outer cylindrical surface of the heat pipe. The dielectric layer 536 may be formed by wrapping a thin (e.g., 3.0, 5.0, 10.0, 50.0, 100.0, 200.0, 250.0 μm or more) dielectric film onto all or selected portions of the outer surface of the heat pipe.

[0255] In another version, the dielectric layer 536 can be grown on the entire or selected portion of the outer cylindrical surface of the heat pipe. For example, the dielectric layer 536 can be grown on the outer cylindrical surface of the aluminum heat pipe 522 using plasma electrolytic oxidation (PEO) or type II or III hard anodization. The heat pipe can have multiple dielectric layers. For example, after the outer surface of the heat pipe is anodized, a thin (e.g., 3.0, 5.0, 10.0, 50.0, 100.0 μm or more) layer of dielectric material (e.g., aluminum nitride) can be formed on the outer cylindrical surface of the metal heat pipe. Other formation processes for the dielectric layer or layers are also contemplated.

[0256] Anodizing is an electrolytic passivation process for creating or thickening a native oxide layer on the surface of a metal part. Anodizing produces oxides roughly half on the surface of the metal part and half in the metal itself. The resulting oxide layer is electrically insulating. The oxide layer can be grown by passing a direct current through an electrolyte, typically sulfuric acid or chromic acid, in which the metal part (e.g., a heat pipe) is fully or partially suspended. The metal part serves as the anode (positive electrode of the electrolytic cell). The current in the electrolyte generates hydrogen at the cathode (negative electrode) and oxygen at the surface of the metal part, promoting oxide formation. The required voltage can range from 1 to 300 V DC. Thicker oxide films formed with sulfuric acid and organic acids typically require higher voltages. The anodizing current varies depending on the total area of ​​the metal part being anodized and is typically 30 to 300 A / m. 2 The oxide layer thickness ranges from 0.01 to 0.01 mm. Controlling conditions such as electrolyte concentration, acidity, solution temperature, and current allows for the formation of a uniform oxide layer. Harder and thicker oxide layers tend to be produced with more concentrated solutions, lower temperatures, higher voltages, and higher currents.

[0257] The anodization process can be used to grow a dielectric layer of oxide on the outer cylindrical surface of an aluminum heat pipe. The heat pipe serves as the anode for the process. An electric current is passed through an electrolytic bath solution in which the heat pipe is partially or completely suspended, generating hydrogen at the cathode (negative electrode) and oxygen on the exterior and / or surface of the heat pipe, promoting oxide formation. The anodization process can be used to grow a dielectric layer, such as dielectric layer 536, only on the exterior surface of aluminum heat pipes, such as heat pipes 522i-522l used in rectifiers or inverters.

[0258] Plasma electrolytic oxidation (PEO) is another electrochemical surface treatment process for growing insulating layers on metal heat pipes. It is similar to anodization, but typically uses a higher electrical potential, generating an electrical discharge and the resulting plasma, which alters the structure of the oxide layer. This process can be used to grow thick (5, 10, 50, 100, 200, 250, 300 μm, or even more), primarily crystalline oxide films on metal heat pipes, such as aluminum, magnesium, and titanium. The film is a chemical conversion of the metal to an oxide, growing both inward and outward from the original metal surface. Plasma electrolytic oxidation of aluminum requires the application of at least 200 V, which locally exceeds the breakdown potential of the growing oxide film, generating electrical discharges. These electrical discharges trigger local plasma reactions, transforming the growing oxide under conditions of high temperature and pressure. The process can include melting, melt flow, resolidification, sintering, and densification of the growing oxide. One of the most important effects is the partial conversion of the oxide from amorphous alumina to a harder crystalline form such as corundum (α-Al2O3). Plasma electrolytic oxidation involves partially or completely immersing a heat pipe in an electrolytic bath, usually consisting of a dilute alkaline solution such as KOH. The heat pipe is electrically connected to one electrode of an electrochemical cell, while the other electrode is typically made of an inert material such as stainless steel, and often consists of the wall of the bath itself. A potential of over 200 V can be applied between these two electrodes. Higher voltages can be used to form thicker oxide layers.

[0259] Anodizing or plasma electrolytic oxidation may offer several advantages over other methods of forming a dielectric layer such as dielectric layer 536 (e.g., spray-applying a dielectric to the outer cylindrical surface of a heat pipe, which may require smoothing to ensure a better thermally conductive interface with the bus bar channel surface in which the heat pipe is housed). For example, anodizing may provide a more mechanically robust dielectric layer. The outer surface of an anodized dielectric layer may be smoother compared to other methods, which may improve heat transfer between a heat sink or bus bar on one side of the dielectric and a heat pipe on the other side.

[0260] Regardless of how the dielectric layer is formed, it electrically insulates the heat pipes from bus bars, heat sinks, or other devices while still allowing heat to be transferred therebetween. In some versions, there is no dielectric between the heat pipes and the switch 304. FIGS. 5A-8 through 5A-10 are bottom, side, and top views, respectively, of an alternative inverter 460iA, which is similar to inverter 460iT, but in which the heat pipes 522 are bare (i.e., lack the dielectric layer 536). FIG. 5A-10 shows the upper electrically insulating heat fins 520 for inverter 460iA.

[0261] 5A-9 and 5A-10, the compact inverter system 460iA includes electrically insulated metal fins 520a-520c, 520-, and 520+. The heat fins 520a-520c are electrically and thermally connected (e.g., soldered) directly to heat pipes 522 whose evaporator ends are electrically and thermally connected (e.g., soldered) directly to the surfaces of the channels 40 of the phase bus bars 418Ta-418Tc, respectively. The heat fin 520+ is electrically and thermally connected (e.g., soldered) directly to the heat pipes 522 whose evaporator ends are electrically and thermally connected (e.g., soldered) directly to the surfaces of the channels 40 of the V+ bus bar 417T. The heat fins 520 are electrically and thermally connected (e.g., soldered) directly to heat pipes 522 whose evaporator ends are electrically and thermally connected (e.g., soldered) directly to the surface of the channel 40 of the V-busbar 412T. As shown in FIG. 5A-10, all of the heat fins are electrically insulated from each other by air gaps. Alternatively, a dielectric material (not shown) may be inserted between all of the heat fins in FIG. 5A-10.

[0262] In general, the diameters of the heat pipes within a busbar or heat sink need not be equal. The number, location, and / or diameter of the heat pipes, including the dielectric layer, may depend on one or more variables. For example, the number, location, and / or diameter of the heat pipes may depend on the desired thermal capacity of the busbar or heat sink in which the heat pipes are housed. Or, the number, location, and / or diameter of the heat pipes may depend on the desired thermal resistance between the switch 304 and the fluid within the heat pipes. Or, the number, location, and / or diameter may depend on optimizing the thermal capacity based on the desired thermal resistance, or vice versa.

[0263] Converters and other power systems may include one or more capacitors (hereinafter referred to as "DC link capacitors") electrically connected between the DC busbars (i.e., the V+ and V- busbars). The DC link capacitors may take the form of film capacitors (e.g., polypropylene film capacitors). The DC link capacitors may take the form of ceramic capacitors (e.g., Class 1 or Class 2 multilayer ceramic capacitors). Other types of DC link capacitors, such as electrolytic capacitors, may also be used. Converters may include a mix of DC link capacitor types. For example, a converter may include one or more thin film DC link capacitors and one or more ceramic DC link capacitors, all electrically connected in parallel between the V+ and V- busbars.

[0264] DC link capacitors can become hot. They may be thermally connected to the V+ and / or V- busbars. One or more DC link capacitors of converters and other power systems may be cooled by thermal connection to the DC busbars to which they are electrically attached.

[0265] The DC link capacitors may be housed in a rectangular parallelepiped-shaped package made of a dielectric material such as plastic. Unless otherwise specified, each DC link capacitor is housed in a rectangular parallelepiped-shaped package having substantially flat dielectric side walls. The DC link capacitors in the package may be referred to as packaged DC link capacitors.

[0266] A "bulk" packaged DC link capacitor (bulk capacitor) may have first and second metal capacitor leads extending from the sidewall. The first and second metal capacitor leads may be electrically and thermally connected to the first and second electrodes of the film capacitor, respectively. The flat surfaces of the first and second metal capacitor leads at the other ends may be electrically and thermally connected to the flat surfaces of the V+ and V- busbars, respectively. The surfaces of the bulk capacitor's flat dielectric sidewalls may be thermally connected to the flat surfaces of the V+ and / or V- busbars, which also function as heat sinks. The opposing surfaces of the bulk capacitor's flat dielectric sidewalls may be thermally connected to the flat surfaces of the V+ and V- busbars, respectively. The thermal connections of the sidewalls and / or capacitor leads enable heat extraction from the bulk capacitor by the DC busbars.

[0267] The packaged ceramic DC link capacitor may have first and second metal terminals at opposite ends of the package. The first and second metal terminals may be electrically and thermally connected to the first and second electrodes of the multilayer ceramic capacitor, respectively. The first and second metal terminals may be electrically connected to the V+ and V- busbars, respectively. Each of the first and second metal terminals may have a flat end face and a flat sidewall surface. The flat end faces of the first and second metal terminals may face opposite directions. The flat surfaces of the first and second metal terminals may be electrically and thermally connected to the flat surfaces of the V+ and V- busbars, respectively. The flat sidewall surfaces of the first and second metal terminals may be electrically and thermally connected to the flat sidewall surfaces of the V+ and V- busbars, respectively. Alternatively, the first and second metal terminals may be electrically connected to first and second wires, respectively, of the PCB, and the first and second wires may be electrically connected to V+ and V- bus bars, respectively.

[0268] The inverters 460iT and 460iA include an exemplary bulk capacitor 403T. The bulk capacitor 403T has four dielectric sidewalls. The bulk capacitor 403T has first and second metal capacitor leads 405Ta and 405Tb, respectively, extending from the front dielectric sidewall of the capacitor. Capacitor leads, including the capacitor lead 405T, may be rectangular in cross section. An example capacitor lead 405T has a height hbc, a length lbc, and a width wbc of approximately 6 mm, 30 mm, and 17 mm, respectively. Capacitor leads, including the capacitor lead 405T, may have opposing substantially flat rectangular top and bottom surfaces. The area of ​​the top and bottom surfaces is approximately 510 mm. 2A majority of the flat surface area of ​​the capacitor leads (e.g., 10, 20, 50, 75, 90%, or more) may be electrically and thermally directly connected (e.g., soldered, press-fit using fasteners such as screws, etc.) to the flat surfaces of the V+ or V- busbars. For example, a majority of the flat bottom area of ​​capacitor lead 405Ta may be electrically and thermally directly connected to the flat surface of the V+ busbar 417T, and a majority of the flat top area of ​​capacitor lead 405Tb may be electrically and thermally directly connected to the flat surface of the V- busbar 412T. The V+ busbar 417 and the V- busbar 412 can extract significant amounts of heat (e.g., 1, 2, 5, 10, 20, 40, 80, 100, 200, 300, 500 watts, or more) from the bulk DC link capacitor 403T via the flat surfaces of capacitor leads 405Ta and / or 405Tb, respectively. The surface of the condenser lead 405 may be connected to the surface of the bus bar near the edge of the bus bar (eg, within 4.0, 3.0, 2.0, 1.0 mm or less) proximate to the end of the evaporator end of the heat pipe.

[0269] Inverter 460iT or inverter 460iA may include a string of packaged ceramic DC link capacitors 433 electrically connected in parallel. For simplicity of illustration, only one packaged ceramic DC link capacitor 433-1 of the string is shown. Each packaged ceramic DC link capacitor 433 may have first and second metal terminals 437-1 and 437-2, respectively, that may be electrically connected to the V+ and V- bus bars, respectively.

[0270] An exemplary packaged ceramic DC link capacitor 433 is mounted on a PCB 435 and electrically connected in parallel. First and second metal terminals 437-1 and 437-2 may each be electrically connected to first and second metal traces 511-1 and 511-2, respectively, on the side of the PCB 435 opposite the packaged ceramic capacitor 433. Metal vias may electrically connect the traces 511-1 and 511-2 to their respective terminals 437-1 and 437-2. Ends of the first and second traces 511-1 and 511-2 may be widened to increase the surface area that can be directly electrically and thermally connected to the respective sidewall surfaces of the V+ and V− bus bars 418T and 412T, respectively.

[0271] Referring back to FIG. 5A-1, 5A-4, or 5A-8, current symbols are shown representing the current flow within inverter system 460iT or 460iA at a given instant. More specifically, FIG. 5A-1, 5A-4, or 5A-8 shows the current flow when high-side switch 304dH of phase b is active and low-side switches 304dL of phases a and c are active and transmitting current to the V- terminal via V- busbar 412T. All other switches in the diagram are inactive. Each current symbol in the inverters herein is drawn with approximately the same length. Each current symbol in the inverters herein is drawn with different widths. Wider current symbols represent larger current values.

[0272] A converter, such as inverter 460iT or 460iA, may include a control PCB, such as control PCB 462iT. A converter, such as inverter 460iT or 460iA, may include a driver PCB, such as driver PCB 461i. The power PCB and the control PCB may be in data communication with each other. A driver PCB, such as driver PCB 461iT, may be electrically connected to switch 304 via a respective connector lead 288 or a respective set of connector leads 288g1 and 288g2. Only connector leads 288gH and 288gL of phase c are shown in FIGS. 5A-5 and 5A-6.

[0273] The driver PCB and the control PCB may have opposing sides. Components (e.g., drivers (e.g., base drivers, gate drivers, etc.), current sensors, voltage sensors, PMICs, MCUs, etc.) may be mounted on one or both sides of the power PCB and the control PCB, such as PCB 461iT or 462iT. Terminals of the components may be electrically connected to traces on the driver PCB and the control PCB. Metal vias may connect the traces on the opposing sides of the driver PCB and the control PCB, such as PCB 461iT or 462iT. The traces on the driver PCB may be electrically connected to respective connector leads 288.

[0274] The driver PCB may include a driver in data communication with each packaged switch 247 via a respective connector lead 288g or a respective set of connector leads 288g1 and 288g2. The drivers on the driver PCB may provide voltage or current control signals to each transistor control terminal or each group of transistor control terminals. The driver PCB may include a PMIC that provides a supply voltage to each driver.

[0275] The driver PCB may include a voltage sensor in data communication with each packaged switch 247 or packaged diode 245 via a respective set of connector leads 288dc and 288ds. The voltage sensor may detect a voltage across the current terminals of switch 304 in packaged switch 247 or diode D in packaged diode 245 via connector leads 288dc and 288ds.

[0276] The driver PCB may include openings through which the respective phase bus bar leads can extend. FIGS. 5A-5 and 5A-6 show examples of phase bus bar leads 465c and 465a, respectively. The phase bus bar leads extend between first and second ends. The first ends may be electrically connected to the phase bus bars.

[0277] The driver PCB may include current sensors connected to wiring on the driver PCB and configured to measure current through each phase busbar lead. Each current sensor may take the form of a current transformer (CT) sensor, and the sensor may have an opening through which the respective phase busbar lead extends. If the current sensor has an opening to accommodate the busbar lead, the current sensor may be aligned with the respective opening in the driver PCB through which the respective phase busbar lead extends. Current sensors without openings may be positioned on the driver PCB near (e.g., within 5 mm, 3 mm, 1 mm, or less) the respective phase busbar lead.

[0278] The driver PCB 461iT of FIGS. 5A-5 and 5A-6 includes a driver 306 in data communication with each packaged switch 247d of phases c and a via a respective connector lead 288g. The driver 306 may be located on the PCB 461iT in close proximity (e.g., within 8 mm, 3 mm, 1 mm, or less) to each connector lead 288g to reduce stray inductance, capacitance, and resistance therebetween. For example, the wiring connection between the driver 306 terminal and each connector lead 288g may be 5, 3, 1 mm, or less. A PMIC provides supply voltage to each driver 306 and may be located as close as possible to the opposite side of the driver PCB 461iT as shown. The driver PCB 461iT of FIGS. 5A-5 and 5A-6 includes a voltage sensor V_Sense in data communication with each packaged switch 247d. The phase busbar leads 465a and 465c extend laterally between first and second ends. The first end of the phase busbar lead 465c is electrically connected to the phase busbar 418Tc, and the second end is electrically connected to the winding Wc. The first end of the phase busbar lead 465a is electrically connected to the phase busbar 418Ta, and the second end is electrically connected to the winding Wa. The phase busbar lead 465c extends through an opening in the PCB 461iT. The phase busbar lead 465a extends through an opening in the PCB 461iT. The current sensor I_Sense-c measures the current flowing through the phase busbar lead 465c. The current sensor I_Sense-a measures the current flowing through the phase busbar lead 465a. The I_Sense-c may have an opening through which the phase busbar connector 465c extends. I_Sense-a may include an opening through which phase bus bar connector 465a extends. Figures 5A-5 and 5A-6 show the drivers 306, voltage sensor V_Sense, PMIC, current sensor I_Sense, and phase bus bar leads 465 for phases a and c.A similar group of drivers 306, voltage sensors V_Sense, PMICs, current sensors I_Sense, and phase bus bar leads 465 are mounted on or extend through PCB 461i for phase b.

[0279] The drivers, voltage sensors, current sensors, etc. implemented on the driver PCB may communicate data with a data processing unit, such as an MCU, implemented on the control PCB. The data processing unit may be located on the control PCB at a position furthest from the phase bus bar leads to reduce the adverse effects of electromagnetic interference (EMI). The data communication may be via a data connection comprising pin and socket connectors, also known as "headers," implemented on the driver PCB and control PCB, respectively. The data connection may comprise a flexible data bus, such as a flexible circuit or flexible PCB. The ends of the flexible circuit or flexible PCB may be electrically connected to the pin and socket headers.

[0280] The resistors (also called "bleed resistors") may be electrically connected between DC bus bars, such as V+ bus bar 417T and V- bus bar 412T, and may conduct a low level of current (e.g., 5.0, 3.0, 2.0, 1.0, 0.5 mA or less) to slowly discharge DC link capacitors, such as package capacitors 405T and 433, after a power converter, such as inverter 460iT, is turned off. For example, the bleed resistors may be mounted on a PCB, such as driver PCB 461 or PCB 435, and electrically connected between bus bars 417T and 412T via traces on the PCB. The bleed resistor may be mounted on the driver PCB 461T, with each terminal of the bleed resistor electrically connected by PCB wiring to the connector lead 288ds (not shown) of the package switch 247dHc of phase c in FIG. 5A-4 and the connector lead 288dc (not shown) of the package switch 247dLc, which are electrically connected to the V+ bus bar 417T and the V- bus bar 412T, respectively.

[0281] FIGS. 5A-5 and 5A-6 show an MCU mounted on a control PCB 462iT. The MCU may communicate data with each driver 306, V_Sense, and I_Sense mounted on the driver PCB 461iT via a data connection 484, which may include a pin and socket connector (not shown) electrically connected to traces on the driver PCB 461iT and control PCB 462iT, respectively. The pins of the pin connector may be directly received in the respective sockets of the socket connector. The driver PCB and control PCB may be parallel to each other. The driver PCB 461iT and control PCB 462iT in FIGS. 5A-5 and 5A-6 are parallel to each other. Alternatively, the control PCB 462iT may be positioned above and parallel to the flat surface of the V+ bus bar 417T. Other configurations are also contemplated.

[0282] rectifier 460rT The packaged switch 247 may also be used in a rectifier. FIGS. 5B-1 and 5B-2 show relevant components of an exemplary rectifier 460rT from the bottom and side, respectively. The rectifier 460rT may be connected to inductive elements, such as inductive elements La through Lc of the LCL filter 162 of FIG. 1C, which in turn is connected to a three-phase AC power source 164, also shown in FIG. 1C. For simplicity, the LCL filter 162 is not shown in the rectifier diagrams of this disclosure. The AC power sources φa through φc are shown connected directly to the phase bus bars of the rectifier, including phase bars 418Ta through 418Tc, respectively, in FIG. 5B-1.

[0283] The rectifier 460rT and the inverter 460iT are generally equivalent, but differences may exist. The microcontroller implemented on the control PCB 462rT of the rectifier system 460rT may be different from the microcontroller implemented on the control PCB 462iT of the inverter system 460iT, and the CPU-executable instructions stored in the memory of the microcontroller implemented on the control PCB 462rT of the rectifier system 460rT may be different from the CPU-executable instructions stored in the memory of the microcontroller implemented on the control PCB 462iT of the inverter system 460iT. The control PCB 462rT may also include a phase-locked loop (PLL) or other components for synchronizing control of the switch 304 to the frequency (e.g., 60 Hertz) of the three-phase AC input voltage provided by the AC power sources φa-φc.

[0284] Inverter 460fb 5C-1-5C-3 show relevant components of an exemplary full-bridge inverter 460fb as viewed from the bottom, left edge, and right edge, respectively. Some components shown in FIGS. 5C-2 and 5C-3 (e.g., driver PCB 461fb and control PCB 462fb) are not shown or are not fully shown in FIG. 5C-1 but are described below. Some components shown in FIG. 5C-1 (e.g., packaged capacitors 403T and 4331) are not shown or are not fully shown in FIG. 5C-2 and 5C-3 but are described below.

[0285] Inverter 460fb includes packaged switch 247d, although it will be appreciated that in alternative versions packaged switch 247d may be replaced with packaged switch 247p or packaged switch 247q.

[0286] All packaged switches 247d of inverter 460fb are identical and may be packaged switches 247dA, 247dB, or 247dD of Figures 3A, 3B, and 3D, respectively.

[0287] Inverter 460fb includes a V+ busbar 417fb, a V- busbar 412fb, and a phase busbar 418fb. Inverter 460fb has two legs, a and b. Each leg includes packaged switches 247dH and 247dL electrically and thermally connected to a phase busbar 418fb, both of which are sandwiched between a V+ busbar 417fb and a V- busbar 412fb. Packaged switches 247dH and 247dL are also electrically and thermally connected to a V+ busbar 417fb and a V- busbar 412fb, respectively.

[0288] 5C-1 shows packaged switch 247dH, V+ bus bar 417fb, phase bus bar 418fb, and V- bus bar 412fb arranged in a line with one another. Packaged switch 247dH in FIG. 5C-1 may have die substrate terminals 230 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the or each flat surface of V+ bus bar 417fb, and die clip terminals 344 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surfaces of each phase bus bar 418fba and 418fbb. These phase bus bars have terminals that are electrically connected to terminals of the load. The packaged switch 247dL in FIG. 5C-1 may have die substrate terminals 230 that are electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surfaces of the respective phase bus bars 418fba and 418fbb, and die clip terminals 344 that are electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface or each flat surface of the V-bus bar 412fb.

[0289] Busbars, such as the V+ busbar 417fb, V- busbar 412fb, and phase busbar 418fb in Figures 5C-1-5C-3, may have a rectangular cross-section. An exemplary phase busbar 418fb may have a height, width, and length of approximately 12 mm, 25 mm, and 20 mm, respectively. An exemplary V+ busbar 417fb and V- busbar 412fb may have a height, width, and length of approximately 8 mm, 25 mm, and 45 mm, respectively.

[0290] 5C-1 to 5C-3 show inverter 460fb with heat pipes 522 housed in the bus bar channels (not shown) of V+ bus bar 417fb, V- bus bar 412fb, and phase bus bar 418fb. All of heat pipes 522 in FIGS. 5C-1 to 5C-3 may have approximately the same length.

[0291] Inverter 460fb may include a packaged DC link capacitor 403T2. First and second metal capacitor leads 405T2a and 405T2b extend from a portion of the capacitor's dielectric wall. The flat bottom surface of capacitor lead 405T2a may be electrically and thermally connected directly (e.g., by soldering, press-fitting with screws or other fasteners, etc.) to a flat surface of a busbar, such as V+ busbar 417fb. Additionally, the flat top surface region of capacitor lead 405Tb2 may be electrically and thermally connected to a flat surface of V- busbar 412fb.

[0292] The inverter 460fb may include a string of packaged ceramic DC link capacitors 433 electrically connected in parallel. For ease of illustration, only one packaged ceramic DC link capacitor 433-1 of the string is shown. The exemplary packaged ceramic DC link capacitor 433 is mounted on a PCB 435. First and second metal terminals 437-1 and 437-2 may be electrically connected to first and second metal traces 511-1 and 511-2, respectively, on the side of the PCB 435 opposite the side on which the capacitors 433 are mounted. Metal vias may electrically connect the traces 511-1 and 511-2 to their respective terminals 437-1 and 437-2. Ends of the first and second traces 511-1 and 511-2 may be widened to increase the surface area that can be directly electrically and thermally connected to the sidewall surfaces of the V+ busbar 417fb and V- busbar 412fb, respectively.

[0293] Figure 5C-1 includes current symbols representing the current flowing through inverter 460fb at a given moment. More specifically, Figure 5C-1 illustrates the current flow when high-side switch 304dH of leg a is activated and low-side switch 304dL of leg b is activated and transmitting current to the V- terminal via V- busbar 412fb. All other switches 304 in the figure are in an inactive state.

[0294] The inverter 460fb may include a control PCB 462fb and a driver PCB 461fb. The drivers 306 on the driver PCB 461fb may control the switches 304 via respective connector leads 288. A PMIC provides a supply voltage to each driver 306 and may be located as close as possible to the driver on the opposite side of the driver PCB 461fb as shown. The driver PCB 461fb includes a voltage sensor V_Sense in data communication with each packaged switch 247d via a respective set of connector leads 288ds and 288dc (not shown).

[0295] FIG. 5C-2 illustrates an example phase bus bar lead 465b extending laterally between a first end and a second end. The first end of the phase bus bar lead 465b is electrically connected to the phase bus bar 418fbb, and the second end is electrically connected to a first terminal of a load (e.g., the primary side of a transformer). The phase bus bar lead 465b extends through an opening in the PCB 460fb. The current sensor I_Sense-b measures the current flowing through the phase bus bar connector 465a. I_Sense-b may include an opening through which the phase bus bar connector 465a extends.

[0296] FIG. 5C-3 illustrates an example phase bus bar lead 465a extending laterally between a first end and a second end. The first end of the phase bus bar lead 465a is electrically connected to the phase bus bar 418fba, and the second end is electrically connected to a second terminal of the load. The phase bus bar lead 465a extends through an opening in the PCB 460fb. The current sensor I_Sense-a measures the current flowing through the phase bus bar connector 465a. The I_Sense-a may include an opening through which the phase bus bar connector 465a extends.

[0297] 5C-2 and 5C-3 show the MCU implemented on the control PCB 462fb. The MCU may communicate data with each driver 306, V_Sense, and I_Sense implemented on the driver PCB 461fb via data connection 484.

[0298] Inverter 460id 5D-1-5D-3 show examples of bottom and side views of relevant components of an example inverter 460id. Some components shown in FIGS. 5D-2 and 5D-3 (e.g., driver PCB 461id and control PCB 462id) are not shown or are not fully shown in FIG. 5D-1 but are described below. Some components (e.g., DC link capacitors) are not fully shown in the figures.

[0299] Inverter 460id has three phases, a to c. Each phase includes four packaged switches 247 and a phase bus bar 418d, which are sandwiched between a V+ bus bar 417d and a V- bus bar 412d. The diagram shows the linear arrangement of packaged switches 247, V+ bus bar 417d, phase bus bar 418d, and V- bus bar 412d relative to one another. Phase bus bars 418da to 418dc are electrically connected to stator windings Wa to Wc, respectively.

[0300] All packaged switches 247 of inverter 460id may be a version of packaged switches 247d, 247p, or 247q. In Figures 5D-1-5D-3, each phase of inverter 460id includes a mix of packaged switch versions. As shown, each phase includes a pair of packaged switches 247d and a pair of packaged switches 247q. Each packaged switch 247d may be packaged switch 247dA, 247dB, 247dC, 247dD, or 247dO of Figure 3A, 3B, 3C, 3D, or 3O, respectively, and each packaged switch 247q may be packaged switch 247qE, 247qF, 247qG, 247qI, 247qJ, 247ql, or 247qP of Figure 3E, 3F, 3G, 3I, 3J, 3L, and 3P, respectively. For example, each packaged switch 247d may be packaged switch 247dO shown in Figure 3O or packaged switch 247dB shown in Figure 3B, and each packaged switch 247q may be packaged switch 247qP shown in Figure 3P or packaged switch 247qF shown in Figure 3F. In another version, each packaged switch 247q of Figure 5C can be replaced with packaged switch 247dB, and each packaged switch 247d can be packaged switch 247dA or 247dO. The packaged switch 247 of inverter 460id can take the form of a packaged switch without connector leads 288ds and / or 288dc. All switches 304 of inverter 460id can be independently controllable by an MCU or other data processing device.

[0301] Each phase packaged switch 247dH and 247qH may have a die substrate terminal 230 electrically and thermally directly connected (e.g., by sintering, press-fitting, etc.) to the flat surface or each flat surface of the V+ bus bar 417d and a die clip terminal 344 electrically and thermally directly connected (e.g., by sintering, press-fitting, etc.) to the flat surface or each flat surface of the corresponding phase bus bar 418d. The phase bus bar 418d has terminals electrically connected to the windings Wa-Wc, respectively. Each phase packaged switch 247dL and 247qL may have a die substrate terminal 230 electrically and thermally directly connected (e.g., by sintering, press-fitting, etc.) to the flat surface or each flat surface of the corresponding phase bus bar 418d and a die clip terminal 344 electrically and thermally directly connected (e.g., by sintering, press-fitting, etc.) to the flat surface or each flat surface of the V- bus bar 412d.

[0302] The V+ busbar 417d, the V- busbar 412d, and the phase busbars 418d may have rectangular cross-sections. An exemplary phase busbar 418d may be approximately 12 mm high, approximately 25 mm wide, and approximately 45 mm long. An exemplary V+ busbar 417d and V- busbar 412d may be approximately 8 mm high, approximately 25 mm wide, and approximately 145 mm long.

[0303] 5D-2 and 5D-3 show inverter 460id with dielectric heat pipes 522 housed in respective channels (not shown) of the bus bar. All heat pipes 522 in FIGS. 5D-1 through 5D-3 may be substantially the same length.

[0304] The inverter 460id may include packaged bulk and ceramic DC-link capacitors similar to those shown in FIG. 5A-1. FIGS. 5D-1 through 5D-3 show only the capacitor leads 405T of two DC-link capacitors 403. In FIG. 5D-2, the flat bottom surface of capacitor lead 405T2a may be electrically and thermally directly connected (e.g., soldered, press-fit with screws or other fasteners, etc.) to a flat surface of a busbar, such as the V+ busbar 417d. The flat top surface region of capacitor lead 405T2b may be electrically and thermally connected to a flat surface of the V- busbar 412d. In FIG. 5D-3, the flat bottom surface of capacitor lead 405T1a may be electrically and thermally directly connected (e.g., soldered, press-fit with screws or other fasteners, etc.) to a flat surface of a busbar, such as the V+ busbar 417d. Additionally, the flat top region of capacitor lead 405T1b may be electrically and thermally connected to the flat surface of V-busbar 412d. Although not shown, inverter 460id may also include a packaged multilayer ceramic DC link capacitor with first and second metal terminals directly electrically and thermally connected to busbars 417d and 412d, respectively.

[0305] FIG. 5D-1 includes current symbols representing the current flowing through inverter system 460i at a given instant. More specifically, FIG. 5D-1 illustrates the current flow when switches 304 of packaged switches 247dH and 247qH of phase a are activated and switches 304 of packaged switches 247dL and 247qL of phases b and c are activated to transmit current to the V− terminal through V− busbar 412d. All other switches in the figure are in an inactive state.

[0306] Inverter 460id may include control PCB 462id and driver PCB 461id. Drivers 306 on driver PCB 461id may control switch 304d via respective connector leads 288. A different set of drivers 306 may control switch 304q via respective sets of connector leads 288g1 and 288g2. A PMIC provides supply voltages to corresponding drivers 306. Driver PCB 461d includes a voltage sensor V_Sense in data communication with respective packaged switch 247d or 247q via respective sets of connector leads 288ds and 288dc (not shown).

[0307] FIG. 5D-2 illustrates an exemplary phase bus bar lead 465c extending laterally between a first end and a second end. The first end of the phase bus bar lead 465c is electrically connected to the phase bus bar 418dc, and the second end is electrically connected to the winding Wc. The phase bus bar lead 465c extends through an opening in the PCB 461id. The current sensor I_Sense-c measures the current flowing through the phase bus bar connector 465c. The I_Sense-c may include an opening through which the phase bus bar connector 465b extends.

[0308] FIG. 5D-3 illustrates an example phase bus bar lead 465a extending laterally between a first end and a second end. The first end of the phase bus bar lead 465a is electrically connected to the phase bus bar 418da, and the second end is electrically connected to the winding Wa. The phase bus bar lead 465a extends through an opening in the PCB 460di. The current sensor I_Sense-a measures the current flowing through the phase bus bar connector 465a. I_Sense-a may include an opening through which the phase bus bar connector 465a passes.

[0309] 5D-2 and 5D-3 show the drivers 306, voltage sensor V_Sense, PMIC, current sensor I_Sense, and phase bus bar leads 465 for phases a and c. A similar group of drivers 306, voltage sensor V_Sense, PMIC, current sensor I_Sense, and phase bus bar leads 465 is mounted on or extends through PCB 461id for phase b.

[0310] 5D-2 and 5D-3 show an MCU implemented on the control PCB 462 id. The MCU may communicate data with each driver 306, V_Sense, and I_Sense implemented on the driver PCB 460 id via data connection 484.

[0311] Passive Rectifier Rectifier 460rT is an example of an "active" rectifier because it uses a packaged switch 247. Passive rectifiers are also contemplated. Passive rectifiers do not use a packaged switch 247. Instead, passive rectifiers use a diode. Compact rectifier 460rT shown in FIGS. 5B-1 and 5B-2 can be converted to a passive rectifier by replacing packaged switch 247d with packaged diode 245M or 245N shown in FIGS. 3M and 3N, respectively.

[0312] FIG. 5E shows an exemplary passive rectifier 460pr in which the packaged switch 247d of FIG. 5B-1 is replaced with a packaged diode 245M. The packaged diode 245M may not have connector leads. The V+ busbar 417T, V- busbar 412T, and phase busbar 418T of FIG. 5B-1 are renamed 417pr, 412pr, and 418pr, respectively, in FIG. 5H. The passive rectifier 460pr may not have a control PCB and a driver PCB.

[0313] The die substrate terminal 230 of the packaged diode 245MH is electrically and thermally attached (e.g., sintered, press-fit, etc.) directly to the or each flat surface of the V+ bus bar 417pr. The die substrate terminal 230 of the packaged diode 245ML is electrically and thermally attached (e.g., sintered, press-fit, etc.) to the flat surface of the corresponding phase bus bar 418pr.

[0314] The die substrate terminals 230 of the packaged diodes 245ML are directly electrically and thermally connected (e.g., sintered, press-fit, etc.) to the flat surfaces of the corresponding phase bus bars 418pr. The die clip terminals 344 of the packaged diodes 245ML are directly electrically and thermally connected (e.g., sintered, press-fit, etc.) to the or each flat surface of the V-bus bar 404pr.

[0315] Vienna Rectifier 400VR1 Figures 5F-1 through 5F-3 show end, front, and back views of relevant components of an exemplary rectifier 400vr1. The rectifier 400vr1 is an example of a three-phase "Wien" rectifier. The rectifier system 400vr1 is not capable of bidirectional operation. The driver PCB 421 and heat fins 520v1 are shown in Figure 5F-1 but not in Figures 5F-2 and 5F-3.

[0316] Referring to FIGS. 5F-2 and 5F-3, the rectifier 400vr1 has three phases, a through c. Each phase may include a bidirectional packaged switch 247q. Phases a through c include packaged switches 247qa through 247qc, respectively. Each of packaged switches 247qa through 247qc may be packaged switches 247qG, 247qI, 247qJ, or 247ql of FIGS. 3G, 3I, 3J, and 3L, respectively. In an alternative version, each phase may include packaged switch 247pK shown in FIG. 3K. All of the switches 304 of the rectifier 400vr1 may be controllable by an MCU or other data processing device.

[0317] The rectifier 400vr1 may include a rectangular V+ busbar 417v1, a V- busbar 412v1, a phase busbar 418v1, and a common busbar 404v1, each of which may also function as a heat sink to cool the switch 304 or the diode D.

[0318] Each of the phase bus bars 418v1 may have a height, width wvpb, and length lvpb of approximately 12 mm, 55 mm, and 20 mm, respectively. The cases of the packaged switches 247qa-247qc may be thermally connected to the phase bus bars 418v1a-418v1c, respectively. The packaged switches 247qa-247qc may have die substrate terminals 230 that are electrically and thermally connected directly (e.g., by sintering, press-fitting, etc.) to the surfaces of the phase bus bars 418v1a-418v1c, respectively. The phase bus bars 418v1a-418v1c are electrically connected to the AC power sources φa-φc, respectively.

[0319] All figures show a common bus bar 404v1, which may have a height, width wvc, and length lvc of approximately 8 mm, 25 mm, and 70 mm, respectively. The case of the packaged switch 247q may be thermally connected to the surface of the bus bar 404v1 and each phase bus bar 418v1.

[0320] 5F-2 and 5F-3 are front and rear views of the rectifier 400vr1 of FIG. 5F-1. As shown in these figures, the V- busbar 412v1 and the V+ busbar 417v1 have a rectangular cross-sectional shape. The busbars 417v1 and 412v1 may have heights, widths wv, and lengths lv of approximately 8 mm, 25 mm, and 70 mm, respectively. In another version, the busbars 412v1 and 417v1 may have different dimensions. The V- busbar 412v1 and the V+ busbar 417v1 have terminals for supplying DC power to devices such as isolated DC / DC converters. Like the busbar 404v1 and the phase busbar 418v1, the busbars 412v1 and 417v1 have channels for holding heat pipes 522.

[0321] 5F-2 and 5F-3 show the linear arrangement of packaged switch 247q, phase bar 418v1, V- bus bar 412v1, V+ bus bar 417v1, and bus bar 404v1 relative to each other in phases a and c.

[0322] Each phase of rectifier 400vr1 may include a pair of packaged diodes 245-1 and 245-2, each including diodes D1 and D2. For illustrative purposes, packaged diodes 245-1 and 245-2 take the form of packaged diode 245m shown in FIG. 3M. The die substrate terminal 230 of packaged diode 245-2 of each phase and the die clip terminal 344 of packaged diode 245-1 are electrically and thermally directly attached (e.g., sintered, press-fit, etc.) to the flat surface or respective flat surfaces of V+ busbar 417v1 and V− busbar 412v1, respectively. The die substrate terminal 230 of packaged diode 245-1 of each phase and the die clip terminal 344 of packaged diode 245-2 are electrically and thermally directly attached (e.g., sintered, press-fit, etc.) to the flat surface or respective flat surfaces of corresponding phase busbar 418v1.

[0323] Die substrate terminals 230 of packaged switches 247qa-247qc are electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surfaces of phase bus bars 418v1a-418v1c, respectively. Die clip terminals 344 of packaged switches 247qa-247qc are electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface or respective flat surfaces of common bus bar 404v1.

[0324] Capacitors C- and C+ may be polarized capacitors as shown and are electrically connected to bus bar 404v1. Capacitors C- and C+ may also be thermally connected to bus bar 404v1. First terminal or lead surfaces of capacitors C- and C+ may be directly connected to the flat surfaces of bus bar 404v1 by sintering, soldering, press-fitting, or other means. Capacitors C- and C+ are electrically connected to bus bars 412v1 and 417v1, respectively. Capacitors C- and C+ may also be thermally connected to bus bars 412v1 and 417v1, respectively. Second terminal or lead surfaces of capacitors C- and C+ may be directly connected to the flat surfaces of V- bus 412v1 and V+ bus bar 417v1, respectively, by sintering, soldering, press-fitting, or other means.

[0325] 5F-1-5F-3 show rectifier 400vr1 with dielectric heat pipes 522 housed in their respective bus bar channels (not shown). Unlike the heat pipes 522 housed in V- bus bar 412v1, V+ bus bar 417v1, and common bus bar 404v1, heat pipes 522 do not extend completely through phase bus bar 418v1. The portion of heat pipe 522 housed in phase bus bar 418v1c is shown with hidden lines in FIG. 5F-1 to illustrate this feature.

[0326] Rectifier 400vr1 may include a driver PCB 421 having drivers 306 electrically connected to and controlling the respective switches 304 via respective sets of connector leads 288g1 and 288g2. Only connector leads 288g1 and 288g2 for phase c are shown in FIG. 5F-1.

[0327] The driver PCB 421 includes a voltage sensor V_Sense, which is in data communication with each packaged switch 247q via a respective set of connector leads 288ds and 288dc (not shown). The exemplary phase bus bar lead 465c in FIG. 5F-1 extends laterally between a first end and a second end. The first end of the phase bus bar lead 465c is electrically connected to the phase bus bar 418v1c, and the second end is electrically connected to the AC power source φc. The phase bus bar lead 465c extends through an opening in the PCB 421. The current sensor I_Sense measures the current flowing through the phase bus bar connector 465c. The I_Sense may include an opening through which the phase bus bar connector 465c extends. FIG. 5F-1 illustrates the voltage sensor V_Sense, PMIC, driver 306, current sensor I_Sense, and phase bus bar lead 465 for phase c. Similar voltage sensors V_Sense, PMICs, drivers 306, current sensors I_Sense, and groups of phase bus bar leads 465 are mounted on or extend through PCB 421 for phases a and b.

[0328] The rectifier 400vr1 may include a control PCB having an MCU in data communication with the driver 306, current sensor I_Sense, voltage sensor V_Sense, and other components mounted on a driver PCB 421. A connector (e.g., a flexible PCB, not shown) may facilitate data communication.

[0329] Solid State Circuit Breaker 500 5I-1 and 5I-2 show bottom and side views, respectively, of relevant components of an exemplary solid-state circuit breaker (SSCB) 500. An SSCB such as SSCB 500 may be electrically connected between the voltage terminals of a battery or other DC voltage source and a system such as an inverter and / or an on-board EV battery charger of the present disclosure.

[0330] SSCB 500 includes packaged switch 247q, although it is understood that packaged switch 247q may be replaced with packaged switch 247pK or 247dD in alternative versions. SSCB 500 includes bus bars 501 and 502, which may have a rectangular cross section. Exemplary bus bars 501 and 502 may be approximately 8 mm high, approximately 25 mm wide, and approximately 45 mm long.

[0331] One or more voltage suppressors may be electrically connected between the bus bars 501 and 502. For example, one or more snubber circuits or snubber capacitors may be electrically connected in parallel between the bus bars 501 and 502. FIG. 5I-2 shows a row of optional packaged ceramic capacitors 433 connected in parallel on the PCB 435cb. Only one capacitor 433-1 is shown. Other types of capacitors are also contemplated. Each packaged ceramic capacitor 433 may include first and second metal terminals 437-1 and 437-2, respectively, electrically connected to the bus bars 501 and 502, respectively. The first and second metal terminals 437-1 and 437-2 may be electrically connected to first and second metal traces 511-1 and 511-2, respectively, on the side of the PCB 435cb opposite the side on which the capacitors 433 are mounted. Metal vias may electrically connect 511-1 and 511-2 to respective terminals 437-1 and 437-2. The ends of first and second traces 511-1 and 511-2 may be widened to increase the surface area that may be electrically and thermally connected to the respective sidewall surfaces of bus bars 501 and 502, respectively.

[0332] All of the packaged switches 247q of the SSCB 500 may be identical. Each packaged switch 247q of the SSCB 500 may be packaged switch 247qG, 247qI, 247qJ, or 247ql of Figures 3G, 3I, 3J, and 3L, respectively.

[0333] 5I-1 illustrates the linear arrangement of packaged switch 247q and bus bars 501 and 502 relative to one another. Packaged switch 247q in FIG. 5I-1 has die substrate terminals 230 that are electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the or each flat surface of bus bar 501, and die clip terminals 344 that are electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the or each flat surface of bus bar 502.

[0334] 5I-1 and 5I-2 show an SSCB 500 with each bus bar channel (not shown) housing a heat pipe 522. All of the heat pipes 522 may have approximately equal lengths.

[0335] SSCB 500 can operate in forward or reverse mode. When operating in forward mode, SSCB 500 can transmit a current I through one or both of switches 304q. FIG. 5I-2 shows SSCB 500 operating in forward mode. When operating in reverse mode, SSCB 500 can transmit a current I through one or both of switches 304q. When SSCB 500 is off, all transistors in switch 304q are inactive, and no current flows through switch 304q, except perhaps leakage current.

[0336] In the forward mode, one or more transistors in switch 304q controlled via respective connector lead 288g1 may be active, and all transistors in switch 304q controlled via connector lead 288g2 may be inactive. In the reverse mode, all transistors in switch 304q controlled via connector lead 288g1 may be inactive, and one or more transistors in switch 304q controlled via respective connector lead 288g2 may be active. If the SSCB 500 uses a packaged switch 247qG or 247ql (e.g., a switch including a BBJT), the SSCB 500 may operate in a forward mode when one or both connector leads 288g1 in the packaged switches 247q1 and 247q2 are driven with a transistor activation current (e.g., a base current to activate a BBJT) and none of the connector leads 288g2 in the packaged switches 247q1 and 247q2 are driven with a transistor activation current, and the SSCB 500 may operate in a reverse mode when none of the connector leads 288g1 in the packaged switches 247q1 and 247q2 are driven with a transistor activation current and one or both connector leads 288g2 in the packaged switches 247q1 and 247q2 are driven with a transistor activation current.

[0337] The SSCB 500 may include a PCB 461cb. The drivers on the PCB 461cb1 may be electrically connected to the respective switches 304q via respective sets of connector leads 288g1 and 288g2. FIG. 5I-2 shows only the drivers 306 and connector leads 288g1 and 288g2 for the switch 247q1. The PMICs provide supply voltages to the respective drivers 306 and may be located as close as possible to the drivers 306. The PCB 461cb in FIG. 5I-2 includes only one voltage sensor, V_Sense, in data communication with the packaged switch 247q1 via connector leads 288ds and 288dc (not shown). FIG. 5I-2 shows the drivers 306 and PMIC for the packaged switch 247q1. A similar group of drivers 306 and PMICs is implemented on the PCB 461cb for the packaged switch 247q2. 5I-2 shows the MCU mounted on PCB 461cb. The MCU may communicate with the driver 306 and V_Sense.

[0338] Variable Frequency Drive 460vfd Power converters may be integrated via a common bus bar to form an integrated power converter. The structure shown in FIG. 5G may be formed by integrating an inverter 460iT and a rectifier 460rT. An AC / AC converter (e.g., a variable frequency drive (VFD)) may be created by integrating an inverter and a rectifier via one or more common bus bars. FIG. 5G shows a bottom view of the relevant components of an exemplary VFD 460vfd.

[0339] FIG. 5G shows the inverter and rectifier sections of VFD 460vfd, respectively, integrated via common V+ busbar 417vfd and V- busbar 412vfd. Some components (i.e., DC link capacitor 403) are not shown in their entirety. VFD 460vfd has three phases, a, b, c.

[0340] 5G shows a VFD 460vfd with heat pipes 522 housed in respective bus bar channels (not shown). All of the heat pipes 522 may be substantially the same length.

[0341] VFD460vfd uses packaged switches 247d, each of which may be packaged switches 247dA, 247dB, or 247dD of FIGS. 3A, 3B, and 3D, respectively. Alternatively, all of the packaged switches in VFD460vfd may be a version of packaged switches 247p or 247q. As shown in FIG. 5G, each phase of the inverter and rectifier sections includes packaged switches 247dH and 247dL. All of the switches 304 in packaged switches 247d of VFD460vfd are independently controllable by the MCU.

[0342] VFD 460vfd includes a V+ busbar 417vfd, a V- busbar 412vfd, an inverter phase busbar 418Ti, and a rectifier phase busbar 418Tr. FIGS. 5G-1 through 5G-3 illustrate the linear and horizontal arrangement of packaged switch 247d, V+ busbar 417vfd, V- busbar 412vfd, inverter phase busbar 418Ti, and rectifier phase busbar 418Tr relative to one another. Inverter phase busbars 418Tia through 418Tic are electrically connected to windings WA through WC, respectively. Rectifier phase busbars 418Tra through 418Trc are electrically connected to AC power sources φa through φc, respectively.

[0343] The V+ busbar 417vfd, the V- busbar 412vfd, the inverter phase busbar 418Ti, and the rectifier phase busbar 418Tr may have rectangular cross-sections. Each of the exemplary inverter and rectifier phase busbars 418Ti and 418Tr may be approximately 12 mm high, 25 mm wide, and 20 mm long, respectively. The exemplary V+ busbar 417vfd and the V- busbar 412vfd may be approximately 8 mm high, 25 mm wide, and 145 mm long, respectively.

[0344] The packaged switches 247diH and 247drH of each phase may have die substrate terminals 230 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface or respective flat surfaces of the V+ bus bar 417vfd. The packaged switches 247diH of each phase of the inverter section may have die clip terminals 344 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface of the respective inverter phase bus bar 418Ti. The packaged switches 247drH of each phase of the rectifier section may have die clip terminals 344 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface of the respective rectifier phase bus bar 418Tr. The packaged switches 247diL and 247drL of each phase may have die clip terminals 344 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the flat surface or respective flat surfaces of the V- bus bar 412vfd. The packaged switch 247diL for each phase of the inverter section may have a die substrate terminal 230 that is electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to a flat surface of the respective inverter phase bus bar 418Ti. The packaged switch 247drL for each phase of the rectifier section may have a die substrate terminal 230 that is electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to a flat surface of the respective rectifier phase bus bar 418Tr.

[0345] Although not fully illustrated, the VFD 460vfd may include a packaged DC link capacitor 403. First and second metal capacitor leads 405T1a and 405T1b may extend from a portion of the packaged capacitor 403. First and second metal capacitor leads 405T2a and 405T2b may extend from a second portion of the packaged capacitor 403. Exemplary capacitor leads 405T may each be approximately 6 mm high, approximately 20 mm long, and approximately 30 mm wide. A majority of the flat bottom area of ​​each of capacitor leads 405T1a and 405T2a may be electrically and thermally directly connected (e.g., soldered, press-fit with screws or other fasteners, etc.) to a flat surface of the V+ bus bar 417vdr. A majority of the flat top area of ​​each of capacitor leads 405T1b and 405T2b may be electrically and thermally directly connected (eg, soldered, press-fit with screws or other fasteners, etc.) to a flat surface of V-bus bar 412vdr.

[0346] The VFD460vfd comprises one or more packaged ceramic DC link capacitors (e.g., multilayer ceramic capacitors) having first and second metal terminals that are electrically and thermally connected directly or indirectly to the flat surfaces of the V+ busbar 417vdr and V- busbar 412vdr, respectively.

[0347] An integrated converter such as that shown in FIG. 5G may be used in an EV. The DC busbars of the integrated converter, such as V+ busbar 417vfd and V- busbar 412vfd in FIG. 5G, may be connected directly or indirectly (e.g., via a DC / DC converter) to respective terminals of the EV's battery. The phase busbars of the inverter section of the integrated converter, such as phase busbar 418Ti in FIG. 5G, may be connected to respective windings W of the EV motor. The phase busbars of the rectifier section of the integrated converter, such as busbar 418Tr in FIG. 5G, may be connected to receive three-phase AC power from a generator in the EV. The generator may be part of the EV's regenerative braking system. When the EV accelerates, the inverter section converts DC power from the battery to three-phase AC power to drive the windings Wa-Wc, and when the EV decelerates (e.g., braking), the rectifier section converts the three-phase AC power from the generator to DC power to charge the EV battery. An MCU mounted on a control PCB (not shown in FIG. 5G) may control the rectifier unit when the EV is decelerating and the inverter unit when the EV is accelerating.

[0348] Other power converters of the present disclosure may also be integrated via a common busbar. Figure 5H illustrates an example in which a rectifier 460rT and an inverter 460fb are integrated via a common V+ busbar and a common V- busbar 417wh and 412wh, respectively, to form a power converter 460wh electrically connected to, for example, winding W of an isolation transformer. Figure 5K illustrates an integrated converter 460c similar to integrated converter 460vfd. Integrated converter 460c includes a rectifier section, an inverter section, and a DC / DC section, with packaged switches 247dHc and 247dLc connected to a V+ busbar 417gc as shown. More specifically, the die clip terminals 344 of the packaged switch 247dHc are electrically and thermally directly connected (e.g., sintered) to the surface of the V+ busbar 417gc, and the die substrate terminals 230 of the packaged switch 247dLc are electrically and thermally directly connected (e.g., sintered) to the surface of the V+ busbar 417gc. The V+ busbar 417gc is an extended version of the phase busbar 418Tic and has more heat pipes. The common busbar 416gc is an extended version of the V+ busbar 417vfd shown in FIG. 5G. The common V- busbar 412gc is an extended version of the V- busbar 412vfd but has fewer heat pipes. The surface of the common V- busbar 412gc is electrically and thermally directly connected (e.g., sintered) to the die clip terminals 344 of each of the low-side packaged switches 247dLc, 247diL, and 247drL. The surface of the common bus bar 416gc is directly electrically and thermally connected (e.g., sintered) to the die substrate terminals 230 of each of the high-side packaged switches 247dHc, 247diH, and 247drH. In addition to independently controlling the switches 304dH and 304dL of the packaged switches in the rectifier and inverter sections, the MCU (not shown) may also independently control the switches 304dH and 304dL of the packaged switches 247dHc and 247dLc in the DC / DC section.In an alternative version, the packaged switch 247dHc of the DC / DC section may be inverted, with the die substrate terminal 230 electrically and thermally directly connected (e.g., sintered) to the surface of the V+ busbar 417gc, and the die clip terminal 344 electrically and thermally connected (e.g., sintered) to the surface of the common busbar 416gc. Although not shown, the V+ busbar 417gc may be electrically connected to the terminals of an inductor. This inductor may be connected in series between the EV battery and the V+ busbar 417gc. The V- busbar 412gc may be electrically connected to the V- battery terminal. The packaged switch 247d of the DC / DC section, together with an inductor (not shown) connected to the V+ busbar 417gc, may be a key element of a DC / DC converter.

[0349] Inverter 460air The converters and solid-state circuit breakers described above use bus bars with embedded heat pipes. These embedded heat pipes can be replaced with air-cooled bus bars. Figures 5J-1 and 5J-2 show the relevant components of an exemplary inverter 460air from front and side views. Some components shown in Figure 5J-2 (e.g., packaged DC link capacitors 403 and 433-1) are not shown or are not fully shown in Figure 5J-1 but are described below. Some components shown in Figure 5J-2 (e.g., driver PCB 461iT and control PCB 462iT) are not shown or are not fully shown in Figure 5J-1 but are described below.

[0350] Inverter 460air is substantially similar to inverter 460iT, except that bus bars 412T, 417T, and 418T are replaced with exemplary air-cooled bus bars 412air, 417air, and 418air, respectively. Like inverter 460iT, inverter 460air is shown with packaged switch 247d, but it is understood that in alternative versions, packaged switch 247d can be replaced with packaged switch 247p or packaged switch 247q. All packaged switches 247 in inverter 460air may be identical. Packaged switch 247d in inverter 460air may be packaged switch 247dA, 247dB, 247dD, or 247O of FIGS. 3A, 3B, 3D, and 3O, respectively. The case surface of packaged switch 247d in FIG. 5J-1 may be thermally connected to a flat surface of V+ busbar 417air, V- busbar 412air, or phase busbar 418air.

[0351] Inverter 460air has three phases, a through c. Each phase, as shown in FIG. 5J-1, includes two packaged switches 247dh and 247dL electrically and thermally connected to a phase bus bar 418air, which are sandwiched together between a V+ bus bar 417air and a V- bus bar 412air. Packaged switches 247dH and 247dL are also electrically and thermally connected to a V+ bus bar 417air and a V- bus bar 412air, respectively. Phase bus bars 418air-c and 418air-b are fluidly connected to each other via a dielectric air coupling 532cb, and phase bus bars 418air-b and 418air-a are fluidly connected to each other via a dielectric air coupling 532ba. The phase bus bars 418air are thermally connected to each other and electrically isolated from each other by air couplings 532. 5J-1 and 5J-2 illustrate the linear arrangement of the packaged switch 247d, the V+ bus bar 417air, the phase bus bar 418air, and the V- bus bar 412air relative to one another.

[0352] The packaged switch 247dH in FIG. 5J-1 may have die substrate terminals 230 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the or each flat surface of the V+ bus bar 417air and die clip terminals 344 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the or each flat surface of the phase bus bars 418air-a through 418air-c, which may be electrically connected to the windings Wa through Wc, respectively. The packaged switch 247dL in FIG. 5J-1 may have die substrate terminals 230 electrically and thermally directly connected (e.g., sintered, press-fit, etc.) to the or each flat surface of the V- bus bar 412air.

[0353] Air-cooled busbars, such as the V+ busbar 417air, the V- busbar 412air, and the phase busbar 418air in FIGS. 5J-1 and 5J-2, may be rectangular. FIG. 5J-1 illustrates the height and length of the air-cooled busbars, and FIG. 5J-2 illustrates the height and width. An exemplary phase busbar 418air may have a height, width, and length of approximately 40 mm, 25 mm, and 20 mm, respectively. An exemplary V+ busbar 417air and a V- busbar 412air may have a height, width, and length of approximately 30 mm, 25 mm, and 70 mm, respectively. The dielectric air coupling 532 may have a rectangular shape and a height, width, and length of approximately 40 mm, 25 mm, and 5 mm, respectively. The air-cooled busbars and dielectric couplings may have different shapes and dimensions to accommodate different converter designs.

[0354] FIG. 5J-3 shows a side view of a dielectric coupling 532ba that provides fluid communication between the phase busbar 418air-a and the phase busbar 418air-b. FIG. 5J-4 shows an end view of the structure of FIG. 5J-3. FIG. 5J-5 and FIG. 5J-6 show side and end views of the V-busbar 412air. The V+ busbar 417air is substantially similar to the V-busbar 412air.

[0355] Air-cooled bus bars, such as phase bus bars 412air, 417air, and 418air, may be extruded from metal such as aluminum or copper. Phase bus bar 418air has four thin (e.g., 25.0, 15.0, 10.0, 5.0, 3.0, 2.0, 1.0 mm, or less) side walls 542-548 connected to each other at right angles. Each of side walls 542-548 has a substantially flat surface facing each other. Heat fins 540 extend between side walls 546 and 548. Heat fins 540 are thermally and electrically connected to side walls 546 and 548. Heat fins 540 have a substantially flat surface facing each other. Heat fins 540 may have a width whf of 10.0, 6.0, 4.0, 2.0, 1.0, 0.5 mm, or less. The length and height of the heat fins 540 are approximately equal to the length and height of the phase bus bar 418. The heat fins 540 may be evenly spaced within the bus bar 418. FIG. 5J-4 shows a phase bus bar 418 with three heat fins 540. In alternative versions, an air-cooled bus bar, such as the phase bus bar 418, may have fewer or more than three heat fins 540. The heat fins 540 and sidewalls define channels 560 through which air can flow within the bus bar 418. The heat fins can extract substantial heat (e.g., 1.0, 5.0, 10.0, 20.0, 50.0, 100.0, 200.0, 300.0, 500.0 W or more) from one or more electrically and thermally connected switches 304 or diodes.

[0356] The dielectric air coupling 532 may be connected (e.g., glued) between the air-cooled phase busbars 418air. The coupling 532 allows air flow between adjacent air-cooled phase busbars. Like the exemplary phase busbar 418air, the exemplary dielectric air coupling 532 has four generally flat sidewalls connected at right angles to each other. The exemplary air coupling 532ba may have dimensions slightly larger than those of the phase busbars 418air-b and 418air-a. The inner flat surfaces of the sidewalls of the coupling 532ba may be connected (e.g., glued) to the outer flat surfaces of the sidewalls of each of the phase busbars 418air-b and 418air-a. The dielectric coupling 532 does not include heat fins as shown in FIG. 5J-4.

[0357] The V-busbar 412air includes four thin (e.g., 25.0, 15.0, 10.0, 5.0, 3.0, 2.0, 1.0 mm, or less) sidewalls 562-568 connected to each other at right angles. Each of the sidewalls 562-568 has a substantially flat surface facing each other. Heat fins 543 extend between the sidewalls 566 and 568. The heat fins 543 are thermally and electrically connected to the sidewalls 566 and 568. The heat fins 543 have substantially flat surfaces facing each other. The width whf of the heat fins 543 may be 10.0, 6.0, 4.0, 2.0, 1.0, 0.5 mm, or less. The length and height of the heat fins 543 are substantially equal to the length and height of the V-busbar 412. The heat fins 543 may be equally spaced within the busbar 412air. 5J-6 shows a V-busbar 412air with three heat fins 543. Alternative versions may use fewer or more than three heat fins 543. The heat fins 543 and sidewalls define channels 570 through which air can flow within the busbar 412air. The heat fins can extract substantial heat (e.g., 1.0, 5.0, 10.0, 20.0, 50.0, 100.0, 200.0, 300.0, 500.0 W or more) from one or more electrically and thermally connected switches 304 or diodes.

[0358] The inverter 460air includes an exemplary bulk DC link capacitor 403air, each having first and second metal capacitor leads 405air-a and 405air-b. The exemplary capacitor leads 405air have a height, length, and width of approximately 6 mm, 30 mm, and 17 mm, respectively. The capacitor leads 405air may have substantially flat, rectangular, opposing upper and lower surfaces. The exemplary upper and lower surface areas are approximately 510 mm2. 2 A majority of the flat surface area of ​​the capacitor leads (e.g., 10, 20, 50, 75, 90%, or more) may be electrically and thermally directly connected (e.g., soldered, press-fit with screws or other fasteners, etc.) to the flat surface of the air-cooled V+ or V- busbar. For example, a majority of the flat bottom area of ​​capacitor lead 405air-a may be electrically and thermally directly connected to the flat surface of the V+ busbar 417air, and a majority of the flat top area of ​​capacitor lead 405air-b may be electrically and thermally directly connected to the flat surface of the V- busbar 412air. The V+ busbar 417air and the V- busbar 412air can extract substantial heat (e.g., 1, 2, 5, 10, 20, 40, 80, 100, 200, 300 watts, or more) from the bulk DC link capacitor 403air via the flat surfaces of capacitor leads 405air-a and / or 405air-b, respectively.

[0359] The inverter 460air may include a string of packaged ceramic DC link capacitors 433 electrically connected in parallel. For simplicity of illustration, only one packaged ceramic DC link capacitor 433-1 of the string is shown. Each packaged ceramic DC link capacitor 433 may include first and second metal terminals 437-1 and 437-2, respectively, that are electrically connected to the air-cooled V+ and V- busbars, respectively.

[0360] An exemplary packaged ceramic DC link capacitor 433 is mounted on a PCB 435air and electrically connected in parallel. First and second metal terminals 437-1 and 437-2 may be electrically connected to first and second metal traces 511-1 and 511-2, respectively, on a side of the PCB 435air opposite the side having the capacitor 433. Metal vias may electrically connect the traces 511-1 and 511-2 to their respective terminals 437-1 and 437-2. The ends of the first and second traces 511-1 and 511-2 may be widened to increase the surface area that can be directly electrically and thermally connected to the sidewall surfaces of the V+ and V− busbars 418air and 412air, respectively.

[0361] Returning to Figure 5J-1, current symbols are shown representing the current flowing through inverter system 460air at a given moment in time. More specifically, Figure 5J-1 illustrates the current flow when high-side switch 304dH of phase a is active and low-side switches 304dL of phases b and c are active, transmitting current to the V- terminal via V-busbar 412air.

[0362] The inverter 460air may include a control PCB 462iT. The inverter 460air may include a driver PCB 461iT. The power PCB and the control PCB are in data communication with each other. The driver PCB 461iT may be electrically connected to the switch 304 via a respective set of connector leads 288. Only connector leads 288gH and 288gL of phase c are shown in FIG. 5J-2.

[0363] The driver PCB 461iT of FIG. 5J-2 includes a driver 306 in data communication with each packaged switch 247d of phase c via a respective connector lead 288g. A PMIC provides a supply voltage to each driver 306 and may be located as close as possible to the driver PCB 461iT on the opposite side of the driver PCB 461iT as shown. The driver PCB 461iT of FIG. 5J-2 includes a voltage sensor V_Sense in data communication with each packaged switch 247d. An exemplary phase bus bar lead 465c extends laterally between a first end and a second end. The first end of the phase bus bar lead 465c is electrically connected to the phase bus bar 418air, and the second end is electrically connected to the winding Wc. The phase bus bar lead 465c extends through an opening in the PCB 461iT. A current sensor I_Sense measures the current flowing through the phase bus bar lead 465c. I_Sense-c may include an opening through which phase bus bar connector 465c extends. FIG. 5J-2 shows the driver 306, voltage sensor V_Sense, PMIC, current sensor I_Sense, and phase bus bar leads 465 for phase c. Similar groups of driver 306, voltage sensor V_Sense, PMIC, current sensor I_Sense, and phase bus bar leads 465 are mounted on or extend through PCB 461i for phases a and b.

[0364] 5J-2 shows an MCU implemented on the control PCB 462iT, which can communicate data with each driver 306, V_Sense, and I_Sense implemented on the driver PCB 461iT via data connections 484.

[0365] Although the present disclosure has been described in connection with several versions, it is not intended that the present disclosure be limited to the versions set forth herein.

Claims

1. 1. An apparatus comprising: a first busbar having a first channel; a first heat pipe housed within the first channel and thermally connected to the first bus bar; a first dielectric that electrically insulates the first heat pipe from the first bus bar; a second bus bar; and a second heat pipe thermally connected to the second bus bar; a first device, a first metal structure having a first surface and a second surface, the first surface and the second surface of the first metal structure being electrically connected, substantially planar, and facing each other; a first metal element having a first surface and a second surface, the first surface and the second surface of the first metal element being electrically connected, substantially planar, and facing each other; a first transistor having a first terminal and a second terminal, wherein the first transistor transmits a current of at least one ampere between the first terminal and the second terminal when in operation, the first terminal and the second terminal having a first surface and a second surface, respectively, the first surface and the second surface of the first terminal and the second terminal being substantially planar and facing each other; a first device having Equipped with the first and second surfaces of the first and second terminals are electrically and thermally connected to the first and second surfaces of the first metal structure and the first metal element, respectively; the first and second surfaces of the first metal element and the first metal structure are electrically and thermally connected to the second bus bar and the first bus bar, respectively.

2. The apparatus of claim 1 , wherein the first metallic element comprises a first seat having an end surface, and the second surface of the first metallic element comprises the end surface.

3. 2. The apparatus of claim 1, wherein the first device comprises a first case having a first opening through which the second side of the first metal structure is electrically and thermally connected to the first bus bar, and the first case having a second opening through which the first side of the second metal element is electrically and thermally connected to the second bus bar.

4. a third bus bar; and a third heat pipe thermally connected to the third bus bar; a second device, a second metal structure having a first surface and a second surface, the first surface and the second surface of the second metal structure being electrically connected, substantially planar, and facing each other; a second metal element having a first surface and a second surface, the first surface and the second surface of the second metal element being electrically connected, substantially planar, and facing each other; a second transistor having a third terminal and a fourth terminal, wherein the second transistor transmits a current of at least 1 ampere between the third terminal and the fourth terminal when in operation, the third terminal and the fourth terminal having a third surface and a fourth surface, respectively, the third surface and the fourth surface being substantially flat and facing each other; and a second device having Further provided with the third and fourth surfaces are sintered to the first and second surfaces of the second metal structure and the second metal element, respectively; the second surface of the second metal structure is electrically and thermally connected to a flat surface of the second bus bar; The apparatus of claim 1 , wherein the first surface of the second metallic element is thermally and electrically connected to the third bus bar.

5. The apparatus of claim 4 , wherein the second metallic element comprises a second seat having an end face, and the second surface of the second metallic element comprises the end face of the second seat.

6. a fourth bus bar; and a fourth heat pipe thermally connected to the fourth bus bar; a third device, a third metal structure having a first surface and a second surface, the first surface and the second surface of the third metal structure being electrically connected, substantially planar, and facing each other; a third metal element having a first surface and a second surface, the first surface and the second surface of the third metal element being electrically connected, substantially planar, and facing each other; a third transistor having a fifth terminal and a sixth terminal, wherein the third transistor transmits a current of 1 ampere or more between the fifth terminal and the sixth terminal when in operation, the fifth terminal and the sixth terminal having a fifth surface and a sixth surface, respectively, the fifth surface and the sixth surface being substantially flat and facing each other; and a third device having Further provided with the fifth and sixth surfaces are sintered to the first and second surfaces of the third metal structure and the third metal element, respectively; the second surface of the third metal structure is directly electrically and thermally connected to a flat surface of the first bus bar; the first surface of the third metal element is directly electrically and thermally connected to the fourth bus bar; The apparatus of claim 4 , wherein the second bus bar is electrically isolated from the fourth bus bar.

7. a fourth device, a fourth metal structure having a first surface and a second surface, the first surface and the second surface of the fourth metal structure being electrically connected, substantially planar, and facing each other; a fourth metal element having a first surface and a second surface, the first surface and the second surface of the fourth metal element being electrically connected, substantially planar, and facing each other; a fourth transistor having a seventh terminal and an eighth terminal, wherein the fourth transistor transmits a current of 1 ampere or more between the seventh terminal and the eighth terminal when in operation, the seventh terminal and the eighth terminal having a seventh surface and an eighth surface, respectively, the seventh surface and the eighth surface being substantially flat and facing each other; and a fourth device having: the seventh and eighth surfaces are directly sintered to the first and second surfaces of the fourth metal structure and the fourth metal element, respectively; the second surface of the fourth metal structure is electrically and thermally connected to the fourth bus bar; The apparatus of claim 6 , wherein the first surface of the fourth metallic element is electrically and thermally connected to a planar surface of the third bus bar.

8. a fifth bus bar; and a fifth heat pipe thermally connected to the fifth bus bar; a fifth device, a fifth metal structure having a first surface and a second surface, the first surface and the second surface of the fifth metal structure being electrically connected, substantially planar, and facing each other; a fifth metal element having a first surface and a second surface, the first surface and the second surface of the fifth metal element being electrically connected, substantially planar, and facing each other; a fifth transistor having a ninth terminal and a tenth terminal, wherein the fifth transistor transmits a current of 1 ampere or more between the ninth terminal and the tenth terminal when the fifth transistor is in operation, the ninth terminal and the tenth terminal having a ninth surface and a tenth surface, respectively, the ninth surface and the tenth surface being substantially flat and facing each other; a fifth device having Further provided with the ninth and tenth surfaces are sintered to the first and second surfaces of the fifth metal structure and the fifth metal element, respectively; the second surface of the fifth metal structure is electrically and thermally connected to the first bus bar; the first surface of the fifth metal element is electrically and thermally connected to the fifth bus bar; The apparatus of claim 7 , wherein the fifth bus bar is electrically isolated from the second and fourth bus bars.

9. a sixth device, a sixth metal structure having a first surface and a second surface, the first surface and the second surface of the sixth metal structure being electrically connected, substantially planar, and facing each other; a sixth metal element having a first surface and a second surface, the first surface and the second surface of the sixth metal element being electrically connected, substantially planar, and facing each other; a sixth transistor having an eleventh terminal and a twelfth terminal, wherein a current of 1 ampere or more is transmitted between the eleventh terminal and the twelfth terminal when the sixth transistor is in operation, the eleventh terminal and the twelfth terminal having an eleventh surface and a twelfth surface, respectively, the eleventh surface and the twelfth surface being substantially flat and facing each other; and a sixth device having: the eleventh and twelfth surfaces are sintered to the first and second surfaces of the sixth metal structure and the sixth metal element, respectively; the second surface of the sixth metal structure is electrically and thermally connected to the fifth bus bar; The apparatus of claim 8 , wherein the first surface of the sixth metallic element is electrically and thermally connected to the third bus bar.

10. The apparatus of claim 1 , further comprising a second dielectric element electrically insulating the second bus bar from the second heat pipe.

11. The apparatus of claim 10 , further comprising metal heat fins electrically and thermally connected to the first and second heat pipes.

12. The apparatus of claim 1 , wherein the second heat pipe is electrically connected to the second bus bar.

13. a first heat fin thermally and electrically connected to the first heat pipe; a second heat fin thermally and electrically connected to the second heat pipe; Further provided with The apparatus of claim 12 , wherein the first heat fin and the second heat fin are electrically isolated from each other.

14. a capacitor having a first electrode and a second electrode; The apparatus of claim 4 , wherein the first electrode and the second electrode are thermally and electrically connected to the first bus bar and the third bus bar.

15. 1. A method comprising: a first channel of the first bus bar receiving a first heat pipe; sintering a first surface of a first terminal of a first transistor to a first surface of a first metal structure; sintering a second surface of a second terminal of the first transistor to a second surface of a first metal pedestal; thermally and electrically connecting a second surface of the first metal pedestal to a second surface of a first metal element; thermally and electrically connecting the second surface of the first metal structure to the first bus bar; Including, the first metal structure has a second surface, the first surface and the second surface of the first metal structure being electrically connected, substantially planar, and facing each other; the first metal element has a second surface, the first surface and the second surface of the first metal element being electrically connected, substantially planar, and facing each other; the first and second surfaces of the first metal base are electrically connected, substantially flat, and opposed to each other; wherein the first transistor is capable of conducting a current of at least one ampere between the first terminal and the second terminal when in operation, and the first and second surfaces of the first and second terminals, respectively, are substantially planar and face each other.

16. 16. The method of claim 15, further comprising forming a first case having a first opening exposing the second surface of the first metal structure for electrical and thermal connection to the first bus bar.

17. 17. The method of claim 16, wherein the first case has a second opening exposing the first surface of the first metal element.

18. 18. The method of claim 17, further comprising thermally and electrically attaching the first surface of the first metallic element to a surface of a second bus bar.

19. The method of claim 17 , further comprising thermally attaching a second heat pipe to the second bus bar.

20. 20. The method of claim 19, further comprising forming a dielectric on a surface of the second heat pipe before the second heat pipe is thermally attached to the second bus bar.

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