Power modules for high-power applications

Abstract

We provide packages that can scale up or down to meet power handling needs without losing performance advantages. [Solution] A power module 10 comprising a substrate 14, a plurality of first vertical power devices Q1 and a plurality of second vertical power devices Q2, a first terminal assembly 18 and a second terminal assembly 20, wherein the substrate 14 has an upper surface having first traces and second traces. The plurality of first vertical power devices and the plurality of second vertical power devices are electrically coupled to form part of a power circuit. The first plurality of vertical power devices are directly electrically and mechanically coupled between the first traces and the bottom of the first elongated bar 18B of the first terminal assembly, and the second plurality of vertical power devices are directly electrically and mechanically coupled between the second traces and the bottom of the second elongated bar 20B of the second terminal assembly.

Description

Technical Field

[0001]

[0001] This disclosure relates to a power module for high-power applications.

Background Art

[0002]

[0002] In high-power applications, multiple components of all or part of a circuit are often packaged in an electronic module. These modules are generally referred to as power modules housed in a molded housing such as a thermoplastic resin or an epoxy resin that encapsulates the components and the circuit board or substrate to which the components are attached. The input / output connections of the power module are provided by a terminal assembly that extends outside the housing to facilitate integration and connection to other systems. Such systems may include electric vehicles, power conversion, and control.

Summary of the Invention

Problems to be Solved by the Invention

[0003]

[0003] The present disclosure relates to a power module comprising a substrate, a first and second plurality of vertical power devices, and first and second terminal assemblies. The substrate has a top surface having a first trace and a second trace. The first plurality of vertical power devices and the second plurality of vertical power devices are electrically coupled to form part of a power circuit. The first terminal assembly has a first elongated bar, at least two first terminal contacts, and at least two first terminal legs, each extending between the first elongated bar and at least two first terminal contacts at different points. The second terminal assembly has a second elongated bar, at least two second terminal contacts, and at least two second terminal legs, each extending between the second elongated bar and at least two second terminal contacts at different points. The first plurality of vertical power devices are electrically and mechanically directly coupled between the first trace and the bottom of the first elongated bar of the first terminal assembly. The second set of vertical power devices are directly coupled thermally, electrically, and mechanically between the second trace and the bottom of the second elongated bar of the second terminal assembly.

[0004]

[0004] The power module may also have a third terminal assembly and a fourth terminal assembly. The third and fourth terminal assemblies may be thermally, electrically, and mechanically coupled to the first trace adjacent to the opposing sides of the substrate.

[0005]

[0005] In one embodiment, the substrate has four sides, a third terminal assembly is on the first side, a fourth terminal assembly is adjacent to the second side opposite the first side, a first terminal assembly is adjacent to the third side between the first and second sides, and a second terminal assembly is between the first and second sides and is adjacent to the fourth side opposite the third side.

[0006]

[0006] In one embodiment, the housing encapsulates at least a portion of the first and second terminal assemblies. Each of at least two first terminal legs extends outward from the side of the housing, and at least two first terminal contacts fold over so that they extend parallel to the upper end of the housing. Similarly, each of at least two second terminal legs extends outward from the side of the housing, and at least two second terminal contacts fold over so that they extend parallel to the upper end of the housing.

[0007]

[0007] In one embodiment, the third terminal assembly and the fourth terminal assembly are electrically and mechanically coupled to the first trace adjacent to the opposing side surface of the substrate, and the substrate is It has four sides, with the third terminal assembly located on the first side, the fourth terminal assembly adjacent to the second side opposite the first side, the first terminal assembly adjacent to the third side between the first and second sides, and the second terminal assembly located between the first and second sides and adjacent to the fourth side opposite the third side.

[0008]

[0008] The third terminal assembly may have a third terminal leg extending outward from the side of the housing and a third terminal contact extending above the upper end of the housing and parallel to the upper end of the housing. The fourth terminal assembly may have a fourth terminal leg extending outward from the side of the housing and a fourth terminal contact extending above the upper end of the housing and parallel to the upper end of the housing.

[0009]

[0009] The upper surface of the housing may have a plurality of grooves that function as creepage extenders, which effectively extend the surface distance between certain conductive elements of the power module.

[0010] In one embodiment, the first bar and at least two first terminal legs of the first terminal assembly form a U-shape, and the second bar and at least two second terminal legs of the second terminal assembly form a U-shape.

[0010]

[0011] In one embodiment, the power module includes a first pin bar and a first A first pin having at least one first pin leg extending from the pin bar The pin assembly also has a first pin bar, which may be positioned adjacent to the first bar and between at least two first terminal legs. The second pin assembly may have a second pin bar and at least one second pin leg extending from the second pin bar. The second pin bar may be positioned adjacent to the second bar and between at least two second terminal legs.

[0011]

[0012] At least one first pin leg may have two first pin legs, and at least one second pin leg may have two second pin legs. In such embodiments, the power module may also have third and fourth pin assemblies. The third pin assembly may have a third pin bar and at least one third pin leg extending from the third pin bar, the third pin bar being adjacent to the first pin bar and positioned between the two first pin legs. The fourth pin assembly may have a fourth pin bar and at least one fourth pin leg extending from the fourth pin bar, the fourth pin bar being adjacent to the second pin bar and positioned between the two second pin legs.

[0012]

[0013] In one embodiment, at least one third pin leg may have two third pin legs, and at least one fourth pin leg may have two fourth pin legs.

[0013]

[0014] In one embodiment, a first pin assembly may be electrically connected to a first contact of a first plurality of vertical power devices via a first bond wire. A second pin assembly may be electrically connected to a second contact of a second plurality of vertical power devices via a second bond wire. A third pin assembly may be electrically connected to a third contact of the first plurality of vertical power devices via a third bond wire. A fourth pin assembly may be electrically connected to a fourth contact of the second plurality of vertical power devices via a fourth bond wire.

[0014]

[0015] In one embodiment, the power module has a housing that encapsulates a first terminal assembly, a second terminal assembly, a first pin assembly, and at least a portion of the second pin assembly. At least one first pin leg and at least one second pin leg extend outward from the respective side portions of the housing, and then into the housing It curves upwards at an angle of 87 to 93 degrees towards the top of the 'g'.

[0015]

[0016] In one embodiment, the first plurality of vertical power devices and the second plurality of vertical power devices are field-effect transistors. Furthermore, the first pin assembly is electrically coupled to one of the gate contacts or source contacts of the first plurality of vertical power devices, and the second pin assembly is electrically coupled to one of the gate contacts or source contacts of the second plurality of vertical power devices.

[0016]

[0017] In one embodiment, a third pin assembly is electrically coupled to the other of the gate contacts or source contacts of a first plurality of vertical power devices. A fourth pin assembly is electrically coupled to the other of the gate contacts or source contacts of a second plurality of vertical power devices.

[0017]

[0018] In one embodiment, a first plurality of vertical power devices has at least three first vertical transistors electrically coupled in parallel with each other, and a second plurality of vertical power devices has at least three second vertical transistors electrically coupled in parallel with each other. In this embodiment, the at least three first vertical transistors and the at least three second vertical transistors may be silicon carbide transistors, and the substrate may be silicon carbide.

[0018]

[0019] In one embodiment, the first plurality of vertical power devices and the second plurality of vertical power devices comprise power field-effect transistors, and the power circuit is a half-H bridge circuit.

[0019]

[0020] In one embodiment, the first terminal assembly has a plurality of jumpers extending from a first elongated bar to a second trace, the plurality of jumpers being electrically and mechanically connected to the second trace.

[0020]

[0021] In one embodiment, the first terminal assembly and the second terminal assembly are components of a common lead frame.

[0022] In one embodiment, the power circuit has a power loop and at least one signal loop. The power loop passes through a first plurality of vertical power devices and a second plurality of vertical power devices. The power loop is independent of at least one signal loop. The at least one signal loop may provide at least one control signal to the first plurality of vertical power devices or the second plurality of vertical power devices. In one configuration, the power loop does not pass through bond wires to the power module.

[0021]

[0023] In one embodiment, both the first terminal assembly and the second terminal assembly have symmetry along at least one axis.

[0024] Based on the above, the present disclosure relates to a small, high-voltage, high-current, low-inductance half-bridge power module designed for next-generation silicon carbide (SiC) and other material system power devices and power electronics applications. The present disclosure utilizes a novel layout incorporating a power substrate with optimized size and cost, having a multifunctional copper layer that interconnects the upper pads of the devices and also functions as an external terminal.

[0022]

[0025] The features of this design are scalability and modularity. The layout can be widened or lengthened to (1) accommodate larger devices or (2) place more devices in parallel. Basically, the package concept can be scaled up or down to meet the power processing needs without losing the performance advantages provided by the package. These packages can be placed in parallel to increase the current of the converter and / or easily form topologies such as full bridges (commonly used in DC-DC power conversion) and three-phase (used in motor drives and inverters).

[0023]

[0026] Scalability and modularity are aspects of this product design, and a wide portfolio of offerings and configurations can be supported by the platform. As will be explained below, the present disclosure can be expanded or shrunk to best meet the needs of a particular application.

[0024]

[0027] Those skilled in the art will understand the scope of the present disclosure and its additional aspects after reading the following detailed description in connection with the accompanying drawings.

Means for Solving the Problems

[0025]

[0028] The accompanying drawings, which are incorporated herein and form a part thereof, illustrate some aspects of the present disclosure and serve to explain the principles of the present disclosure together with the description.

Brief Description of the Drawings

[0026] [Figure 1]

[0029] This is a schematic diagram of a typical half-H bridge circuit. [Figure 2]

[0030] Figure 1 illustrates an example of the actual implementation of the half-H bridge circuit. [Figure 3]

[0031] This is an isometric view of the external structure of a power module according to the first embodiment of this disclosure. [Figure 4]

[0032] This is an isometric view of the internal structure of the first embodiment of the present disclosure. [Figure 5]

[0033] This is a top view of the internal structure of the first embodiment of the present disclosure. [Figure 6]

[0034] This is an exploded view of the first embodiment of the present disclosure. [Figure 7]

[0035] This is a top view of the internal structure of an alternative embodiment of the present disclosure. [Figure 8]

[0036] This figure illustrates an exemplary power loop of the first embodiment of the present disclosure. [Figure 9A]

[0037] This figure illustrates a first embodiment of terminal connection to the lower layer of a low-inductance bus bar according to the present disclosure. [Figure 9B]

[0038] This figure illustrates a first embodiment of terminal connection to the upper layer of a low-inductance busbar according to the present disclosure. [Figure 9C]

[0039] This figure illustrates a second embodiment of terminal connection to the upper layer of a low-inductance busbar according to the present disclosure. [Figure 10]

[0040] Figure 10A illustrates a second embodiment of terminal connection to the lower layer of a low-inductance bus according to the present disclosure.

[0041] Figure 10B illustrates a third embodiment of terminal connection to the upper layer of a low-inductance bus according to the present disclosure. [Figure 11]

[0042] This figure illustrates an exemplary signal loop according to the first embodiment of the present disclosure. [Figure 12]

[0043] This figure illustrates direct coupling to a power board according to one embodiment of the present disclosure. [Figure 13]

[0044] This diagram illustrates the leveling of current paths between devices due to a mismatch in transconductance. [Figure 14A]

[0045] This is a front isometric view of the external housing of a power module according to one embodiment of the present disclosure. [Figure 14B] This is a rear isometric view of the external housing of a power module according to one embodiment of the present disclosure. [Figure 14C]

[0046] Figure 14A is a top view of the external housing of the power module. [Figure 14D] Figures 14A and 14B are cross-sectional views of the external housing of the power module. [Figure 15]

[0047] This figure illustrates the contour of a power module housing according to one embodiment of the present disclosure. [Figure 16]

[0048] Figure 16A illustrates various examples of signal pin assemblies according to the present disclosure. Figure 16B illustrates various examples of signal pin assemblies according to the present disclosure. Figure 16C illustrates various examples of signal pin assemblies according to the present disclosure. Figure 16D illustrates various examples of signal pin assemblies according to the present disclosure. [Figure 17]

[0049] Figure 17A illustrates an example of signal pin trimming according to the present disclosure. Figure 17B illustrates an example of signal pin trimming according to the present disclosure. [Figure 18]

[0050] This figure illustrates the features of a lead frame according to one embodiment of the present disclosure. [Figure 19]

[0051] Figure 19A is an isometric view of the lead frame portion according to this disclosure. Figure 19B is a plan view of the lead frame portion according to this disclosure. [Figure 20]

[0052] This figure illustrates one embodiment of the read frame array according to the present disclosure. [Figure 21]

[0053] This figure illustrates a more extensive variation of the power module described herein. [Figure 22]

[0054] Figure 22A illustrates a fully populated power module according to the present disclosure. Figure 22B illustrates a partially populated power module according to the present disclosure. [Figure 23]

[0055] This figure illustrates an example of a parallelized power module having a stacked bus wiring to form a higher-power half-bridge, according to one embodiment of the present disclosure. [Figure 24]

[0056] This figure illustrates a power module configured as a full-bridge topology according to one embodiment of the present disclosure. [Figure 25]

[0057] This figure illustrates a power module configured as a three-phase topology according to one embodiment of the present disclosure. [Figure 26]

[0058] This figure illustrates a power module arranged in a three-phase topology having two power modules in parallel for each leg, according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0027]

[0059] The embodiments described below provide the information necessary to enable those skilled in the art to carry out the embodiments and illustrate the best mode of carrying out the embodiments. By reading the following description in reference to the accompanying drawings, those skilled in the art will understand the concepts of this disclosure and recognize the uses of these concepts not specifically mentioned herein. It should be understood that these concepts and uses are within the scope of this disclosure and the accompanying claims.

[0028]

[0060] This specification uses terms such as "first," "second," etc., to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are simply used to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be called a second element, and similarly, a second element may be called a first element. The terms "and / or" as used herein include any and all combinations of one or more of the associated list items.

[0029]

[0061] When an element such as a layer, region, or substrate is described as being "on top of" or "extending above" another element, it is understood that it is directly on top of the other element, extends directly above it, or may have an intervening element. In contrast, when an element is described as being "directly on top of" or "extending directly above" another element, there is no intervening element. Similarly, when an element such as a layer, region, or substrate is described as being "above" or "extending above" another element, it is understood that it is directly above or can extend directly above the other element, or may also have an intervening element. In contrast, when an element is described as being "directly above" or "extending directly above" another element, there is no intervening element. When an element is described as being "connected" or "bonded" to another element, it is understood that it is the other It is understood that elements can be directly connected or joined, or that intermediary elements may exist. In contrast, when an element is said to be "directly connected" or "directly joined" to another element, no intermediary elements are present.

[0030]

[0062] Relative terms such as “downward,” “upward,” “upper side,” “lower side,” “horizontal,” or “vertical” may be used herein to describe the relationship between one element, layer, or region and another, as illustrated in the figures. It is understood that these terms and the terms discussed above are intended to encompass various orientations of the device, in addition to the orientation shown in the figures.

[0031]

[0063] The terms used herein are for the sole purpose of describing specific embodiments and are not intended to limit the disclosure. Where used herein, the singular forms “a,” “an,” and “the” are intended to include the plural form unless the context explicitly indicates otherwise. The terms “equipped,” “equipped,” “contain,” and / or “contain” are, where used herein, intended to describe the described features, wholes (integers), steps. It is understood that this specifies the existence of a p, behavior, element, and / or component, but does not exclude the existence or addition of one or more other features, completes, steps, behaviors, elements, components, and / or groups thereof.

[0032]

[0064] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those generally understood by those skilled in the art in which this disclosure pertains. Terms used herein should be construed to have meanings consistent with their meanings in the context of this specification and related art, and it should be further understood that they should not be construed in an idealized or overly formal sense unless expressly defined herein.

[0033]

[0065] This disclosure relates to power modules used in high-power applications. Power modules may include one or more power semiconductor devices arranged in various circuit topologies, such as metal oxide semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), and diodes. Typical circuit topologies include, but are not limited to, single-switch, half-H-bridge, full-H-bridge, and three-phase switching circuits, often referred to as 6-packs.

[0034]

[0066] In the following discussion, a half-bridge circuit will be used to facilitate understanding of the packaging concepts disclosed herein. A basic half-H-bridge circuit is a common power circuit used to switch between different voltages for loads such as motors, as illustrated in Figure 1. The main components of a half-H-bridge circuit are a high-side transistor Q1 and a low-side transistor Q2 coupled in series between the V+ and V- terminals. In this example, transistors Q1 and Q2 are Assume that the transistors are power MOSFETs with drain (D), gate (G1, G2), source (S), and source-Kelvin (K1, K2) connections. The drain (D) of transistor Q1 is coupled to the V+ terminal, and the source (S) of transistor Q2 is coupled to the V- terminal. The source of transistor Q1 and the drain of transistor Q2 are both coupled to the MID terminal, which is essentially an output node connected to a load (not shown).

[0035]

[0067] To increase the power handling capacity, multiple power devices can be coupled in parallel. In the illustrated embodiment, as shown in Figure 2, transistor Q1 is represented by three transistors Q1', Q1'', Q1''' coupled in parallel, and transistor Q2 is represented by three transistors Q2', Q2'', Q2'''' coupled in parallel. For brevity and readability, parallel transistors Q1', Q1'', Q 1''' is collectively referred to as transistor Q1, and transistors Q2', Q2'', and Q2''' are collectively referred to as transistor Q2. In this example, transistors Q1 and Q2 are vertical N-channel MOSFETs, with the drain contact located at the bottom of the device and the source, gate, and source-Kelvin contacts located at the top of the device. The half-H bridge circuit in Figure 2 is implemented in the embodiment of the power module described below, but is only one of many types of circuits that benefit from the concepts provided herein.

[0036]

[0068] An exemplary power module 10 according to the first embodiment is illustrated in Figures 3, 4, 5, and 6. Figure 3 is an isometric view of the power module 10 with a moldable housing 12. Figures 4 and 5 are isometric and plan views of the power module 10 without the encapsulated molded housing 12. Figure 6 is an exploded view of the power module 10. In the following description, Figures 3, 4, 5, and 6 will be referred to collectively.

[0037]

[0069] The core of the power module 10 contains a substrate 14 on which power devices 16 are mounted on its upper surface. In this embodiment, the power devices 16 are transistors Q1 (i.e., Q1', Q1'', Q1''') and transistors Q2 (i.e., Q2', Q2'', Q2''''). A first terminal assembly, referred to as the V-terminal assembly 18, is mounted above transistor Q2(16) near side A of the power module 10. The V-terminal assembly 18 is conductive and is mounted directly to the source contact on the upper side of transistor Q2 to form the V-node in Figure 2.

[0038]

[0070] Two opposing terminals, referred to as the V+ terminal assembly 22, are mounted on the first trace / pad 34 (Figure 6) on the upper surface of the substrate 14 near sides C and D. Transistor Q1 is mounted on the substrate 14 such that the drain of transistor Q1 is directly attached to the first trace / pad 34. Thus, the drain of transistor Q1 and the V+ terminal assembly 22 form the V+ node in Figure 2.

[0039]

[0071] Another terminal assembly, referred to as the MID-terminal assembly 20, is mounted above transistor Q1(16) near side B of the power module 10. The MID-terminal assembly 20 is conductive and mounts directly to the source contact on the upper side of transistor Q1. The MID-terminal assembly 20 extends to a second trace / pad 34, which is directly coupled to the drain contact of transistor Q2, and includes an integrated jumper 20J that is directly coupled. Thus, the drain contact of transistor Q2, the source contact of transistor Q1, and the MID-terminal assembly 20 form the MID node in Figure 2.

[0040]

[0072] The gate and source-Kelvin contacts (G1, K1) of transistor Q1 are electrically coupled to pin assemblies 24, 26, respectively, using bond wires 32. Similarly, the gate and source-Kelvin contacts (G2, K2) of transistor Q2 are electrically coupled to pin assemblies 28, 30, respectively, using bond wires 32. Pin assemblies 24, 26, 28, and 30 are mounted directly to the top surface of the substrate 14, and are electrically isolated not only from each other but also from the high-power V-nodes, V+ nodes, and MID-nodes. Further details regarding the design and geometry of pin assemblies 24, 26, 28, 30, V-terminal assembly 18, the opposing MID-terminal assembly 20, and V+ terminal assembly 22 are provided below. In particular, such designs may include additional pins or pin assemblies that provide input or output nodes to the electronic equipment provided by the power module 10. These additional pins and pin assemblies can be used for current sensing, temperature sensing, bias application, etc.

[0041]

[0073] Now, refer to the exploded view of the power module 10 in Figure 6. Starting from the bottom of the figure, the power device 16, including transistors Q1 and Q2, uses device mounting material 40. The device is then mounted to the first trace 34 and the second trace 36 at mounting position 38. The device mounting material 40 is solder, adhesive, sintered metal, etc., and provides mechanical structure, high current interconnection, and high thermal conductivity.

[0042]

[0074] The pin assemblies 24, 26, 28, 30, the V-terminal assembly 18, the MID-terminal assembly 20, and the V+ terminal assembly 22 are formed from a single lead frame 44. The power device 16 and the upper end portion of the substrate 14 are connected to the corresponding bottom portions of the V-terminal assembly 18, the MID-terminal assembly 20, and the V+ terminal assembly 22 using lead frame mounting material 42. The lead frame mounting material can be solder, adhesive, sintered metal, laser welding, ultrasonic welding, etc., and provides mechanical structure, high current interconnection, and high thermal conductivity. The lead frame 44 is typically a metal contact strip for high-current external and internal interconnections. The contacts are bonded together on a single sheet, often with multiple products per sheet, processed as an array before being formed and individualized.

[0043]

[0075] Bond wires 32 are typically used to connect the control contacts of the power device 16 to various pin assemblies 24, 26, 28, and 30. Bond wires 32 may be large-diameter wires bonded by ultrasound or thermal sound waves, which can support relatively high-current electrical interconnections. Alternatively, the pin assemblies 24, 26, 28, and 30 may be directly coupled to the power device 16, for example, to traces on the substrate 18.

[0044]

[0076] The housing 12 is formed using a transfer or injection molding process and may provide mechanical structure and high-voltage insulation. The housing 12 encapsulates the internal components of the power module 10. The molded compound used for the housing 12 may be a transfer or compression-molded epoxy molded compound (EMC) that can provide mechanical structure, high-voltage insulation, coefficient of thermal expansion (CTE) matching, and low humidity absorption.

[0045]

[0077] The V-terminal assembly 18 includes a first elongated bar 18B located between two terminal legs 18L. In the illustrated embodiment, the first elongated bar 18B and the two terminal legs 18L together form a U-shape. Other shapes, such as T-shapes, V-shapes, and C-shapes, are conceivable. Each of the terminal legs 18L has a shape that extends outward from the first bar 18B toward side A of the power module 10, passes through the side of the housing 12, curves upward toward the upper end of the housing 12, and then curves inward above a portion of the upper end of the housing 12, in order to provide the V-terminal contact 18C. Thus, the distal portion of each terminal leg 18L is folded back above its intermediate portion. As described above, the bottom portion of the first bar 18B of the V-terminal assembly 18 is directly attached to the source contact of the transistor Q2 (power device 16). The V-terminal contact 18C at the exposed distal end of the terminal leg 18L provides a terminal contact for the first terminal assembly 18.

[0046]

[0078] Similarly, the MID-terminal assembly 20 includes a second elongated bar 20B located between the two terminal legs 20L. The second bar 20B and the two terminal legs 20L together form a U-shape in the exemplary embodiment. Other shapes, such as T-shapes, V-shapes, and C-shapes, are conceivable. Each of the terminal legs 20L has a shape that extends outward from the end of the second bar 20B toward the side B of the power module, passes through the side of the housing 12, curves upward toward the upper end of the housing 12, and then curves inward above a portion of the upper end of the housing 12, in order to provide the MID-terminal contact 20C. Thus, the distal portion of each terminal leg 20L is folded back above its middle portion. The bottom portion of the second bar 20B of the MID-terminal assembly 20 is directly attached to the source contact of the transistor Q1 (power device 16). The exposed distal end of the second terminal leg 30 provides a terminal contact for the second terminal assembly 20.

[0047]

[0079] In this embodiment, the MID-terminal assembly 20 also includes a plurality (three) integrally formed jumpers 20J extending from the second bar 20B toward the first bar 18B of the first terminal assembly 18. The distal ends of the jumpers 20J are mounted directly to the first trace 34 on the upper surface of the substrate 14, as described above. The jumpers 20J may be replaced by a single bar. Furthermore, the number of jumpers 20J may vary depending on the embodiment. In certain embodiments, there is one jumper 20J for each power device 16 coupled to the MID-terminal assembly 20.

[0048]

[0080] The two opposing V+ terminal assemblies 22 each have a shape similar to the terminal legs 18L, 20L of the first terminal assembly 18 and the second terminal assembly 20. Other shapes are also possible. One end of each opposing terminal 22 is directly attached to the second trace 36 at the upper edge of the substrate 14. From the substrate 14, each opposing terminal 22 extends outward toward sides C and D of the power module 10, passes through each side of the housing 12, curves upward toward the upper edge of the housing 12, and then curves inward above a portion of the upper edge of the housing 12. In this way, the distal portion of each V+ terminal assembly 22 is folded back above its intermediate portion. The exposed distal end of the opposing terminal 22 provides the terminal contact 22C for the V+ terminal assembly 22. As illustrated, the V- terminal assembly 18 and the MID- terminal assembly 20 are located on opposing sides A and B of the power module 10. The two opposing V+ terminal assemblies 22 are located on the remaining opposing sides C and D of the power module 10. In particular, the V- terminal contact 18C, V+ terminal contact 22C, and MID- terminal contact 20C can be coplanar or nonplanar depending on the application. Nonplanar configurations, where the contacts are located on two, three, or more different planes, may provide additional options for connecting these contacts to an external busbar.

[0049]

[0081] Groups of nested signal pin assemblies 24, 26 and signal pin assemblies 28, 30 are provided between the terminal leg 18L of the V-terminal assembly 18 and the terminal leg 20L of the MID-terminal assembly 20. In the illustrated embodiment, the pin assemblies 24, 26, 28, 30 are U-shaped and include pin bars 24B, 26B, 28B, 30B and a pair of pin legs 24L, 26L, 28L, 30L extending from each pin bar 24B, 26B, 28B, 30B. The pin legs 24L, 26L, 28L, 30L extend outward through each side of the housing 12 and bend vertically upward. Bond wires 32 electrically connect the power device 16 to the pin bars 24B, 26B, 28B, 30 of the pin assemblies 24, 26, 28, 30.

[0050]

[0082] Generally, power modules have two categories of electrical loops: power loops and signal loops. The power loop is a high-voltage, high-current path through transistors Q1 and Q2 to supply power to a load via the drain (or collector) and source (or emitter) of the transistors Q1 and Q2, which are typically connected to the MID-terminal assembly 20. The signal loop is a low-voltage, low-current path through the gates G1 and G2 (or base) and source S (or emitter) of transistors Q1 and Q2. The gate-source (or base-emitter) signal path operates transistors Q1 and Q2, effectively turning them on or off. As detailed below, the signal loop may also involve source-Kelvin connections K1 and K2 of transistors Q1 and Q2.

[0051]

[0083] The power loop effectively extends between the V+ terminal assembly 22 and the V- terminal assembly 18. The V+ terminal assembly 22 and the V- terminal assembly 18 are typically connected to both sides of a DC power source, such as a battery in parallel with a large capacitance. An exemplary power loop of the illustrated power module 10 is illustrated in Figure 8.

[0052]

[0084] The opposing V+ terminal assemblies 22 are directly attached to the opposing ends of the second trace 36 on the substrate 14. Power flows into the power module 10 through the contacts 22C and legs 22C of the two V+ terminal assemblies 22. Thus, power flows through the terminal assemblies 22 to both ends of the second trace 36 on the substrate 14 and to the drain contact of transistor Q1. The drain contact of transistor Q1 is located at the bottom of transistor Q1 and is also directly attached to the second trace 36. Transistor Q1 is mounted on the second trace 36 between the points where the two V+ terminal assemblies 22 are attached to the second trace 36, and transistor Q1 is spaced equally apart from each other and from the mounting points of the two V+ terminal assemblies 22.

[0053]

[0085] Next, power flows upward through transistor Q1, from its drain to its source. The source of transistor Q1 is attached to the bottom side of the second bar 20B of the intermediate terminal assembly 20. The intermediate terminal jumper 20J of the intermediate terminal assembly 20 connects the second bar 20B of the intermediate terminal assembly 20 to the first trace 34 on the substrate 14. The drain of transistor Q2 is directly attached to the first trace 34, spaced equally apart from each other. From the drain of transistor Q2, power flows through transistor Q2 to its source. The source of transistor Q2 is directly connected to the bottom side of the first bar 18B of the V-terminal assembly 18. Thus, power flows along the first bar 18B through the opposing leg 18L to the contact 18C of the V-terminal assembly 18.

[0054]

[0086] By using symmetrical V+ terminal assembly 22 and symmetrical V- terminal assembly 18, current sharing between devices is leveled, allowing the use of smaller external contacts, which helps in panelizing the lead frame, and inductance is significantly reduced by shortening the overall current path of the power loop. As will be further described below, the contacts 18C, 20C, and 22C of the V- terminal assembly 18, MID- terminal assembly 20, and V+ terminal assembly 22 may be electrically coupled external interconnects using laser welding, soldering, ultrasonic welding, mechanical coupling (clamps, springs, etc.), conductive adhesive, or other conductive coupling.

[0055]

[0087] Current must flow through a closed circuit. Therefore, the stray inductance of the package itself is not the only factor contributing to the total loop inductance. The total loop inductance, including the power supply, external bus wiring and wiring, and the capacitance of the power supply and capacitors provided across the power module 10 itself, should be considered. Thus, the internal layout of the power module 10 must not only be low inductance, but the positions of the V- terminal assembly 18, MID- terminal assembly 20, and V+ terminal assembly 22 must also allow low-inductance multilayer bus wiring or similar interconnection methods to connect the power module 10 to a DC power supply.

[0056]

[0088] There are many effective approaches for connecting terminals to high-performance bus wiring. Figures 9A and 9B illustrate an approach using laminated buses, namely V-bus 48, MID-bus 50, and V+bus 52, to connect to the V-terminal assembly 18, MID-terminal assembly 20, and V+ terminal assembly 22, respectively. In this manner, the metal plane for bus wiring extends above the upper end of the power module 10. For clarity, only the metal components of V-bus 48, MID-bus 50, and V+bus 52 are shown, and the laminated film itself is not. The illustrated configuration provides a high-density, low-inductance solution that allows adjacent power modules 10 to be placed close to each other, such as for parallelization or the formation of a multi-module topology.

[0057]

[0089] Referring particularly to Figure 9A, the V-bus 48 has a body 48B from which two contacts 48C extend. Contacts 48C are physically and electrically connected to contact 18C of the V-terminal assembly 18. Similarly, the MID bus 50 has a body 50B from which two contacts 50C extend. Contacts 50C are physically and electrically connected to contact 20C of the MID terminal assembly 20. Referring to Figure 9B, the V+ bus 52 has a body 52B from which a single wide contact 52C extends. Contact 52C is physically and electrically connected to contact 22C of the opposing V+ terminal assembly 22. The opening in the V+ bus 52 provides access to contact 48C of the V-bus 48 and passage of pin assemblies 28, 30 for the gate G2 and source-Kelvin K2 signals. Figure 9B shows a bend in the V+ busbar 48 that can be avoided in some situations by raising the V+ terminal assembly 22 so that it is not coplanar with the V- terminal assembly 18.

[0058]

[0090] Figure 9C provides an alternative configuration for the V+ busbar 52. The V+ busbar 52 has an extension 52E extending from the main body 52B. The main body has two opposing legs 52F that descend from the extension 52E to the contact 22 of the V+ terminal assembly 22. The configuration in Figure 9C sacrifices some inductance (i.e., the inductance increases due to the smaller stacking area) in exchange for reduced strain and reduced rigidity compared to the configuration in Figure 9B.

[0059]

[0091] Figures 10A and 10B illustrate an alternative bus routing approach, where the bus routing extends longer along the sides or perimeter of the power module 10. This can be useful in situations where more access to the contact area or power module 10 is required, such as when a soldering or welding tool needs to directly touch the metal surfaces of various contacts.

[0060]

[0092] Referring particularly to Figure 10A, the V-bus 48' has a body 48B' from which two contacts 48C' extend. The V-bus 48' is offset outward around the power module 10, and the two contacts 48C' wrap around the opposing sides of the power module 10 before extending inward and downward to contact the contacts 18C of the V-terminal assembly 18. Similarly, the MID bus 50' has a body 50B' from which two contacts 50C' extend. The MID bus 50' is offset outward around the power module 10, and the two contacts 50C' wrap around the opposing sides of the power module 10 before extending inward and downward to contact the contacts 20C of the MID-terminal assembly 20.

[0061]

[0093] Referring to Figure 10B, the V+ bus 52' is offset outward around the power module 10 and above the V- bus 48'. The V+ bus 52' has two contacts 52C' that wrap around the opposing sides of the power module 10 before extending inward and downward to contact the respective contacts 22C of the V+ terminal assembly 22. Depending on the specific system configuration, many more bus wiring approaches and module variations can be envisioned. The ultimate goal is to provide a versatile and effective terminal arrangement that enables a variety of end-user solutions.

[0062]

[0094] The signal loops at each transistor (Q1, Q2), or the gate and source connections, also benefit from low impedance, minimizing the voltage stress on the gates of transistors Q1 and Q2 during switching. While adding resistors can buffer or reduce gate stress, this often results in more complex and costly packages and slower switching speeds. Most importantly, to achieve optimal switching performance, the power loop and signal loop must be completely isolated from each other, and switching losses must be kept low with fast, well-controlled dynamics.

[0063]

[0095] Drain-source (or collector-emitter) and gate-source (or gate-emitter) loops share the same connection at the device's source (or emitter). When a power path is coupled to a signal path, either positive or negative feedback introduces additional dynamics. Typically, negative feedback results in extra losses because the coupling of the power path competes with the control signal (i.e., when the control signal is trying to turn the device on, the coupling of the power path tries to turn the device off). Positive feedback is usually unstable because the coupling of the power path amplifies the control signal until the device is destroyed. Ultimately, coupling of power paths and signal paths results in reduced switching quality, slower switching speeds, increased losses, and the potential for destruction.

[0064]

[0096] Therefore, independent loops improve switching quality. In the illustrated embodiment, the power source connections have separate paths from the signal source (referred to as source Kelvin) so that one does not overlap or interfere with the other. The closer the individual connections are to the transistors, the better the switching performance.

[0065]

[0097] Figure 11 illustrates the internal signal loop of the exemplary embodiment. The signal loop of transistor Q1 flows through the G1 pin assembly 24, then through the bond wire 32 to the gate contact of transistor Q1, where the signal is supplied to transistor Q1. The signal loop flows from transistor Q1 through its source contact. From the source contact, the signal loop flows through another bond wire 32 and directly to the K1 pin assembly 26, passing through the K1 pin assembly 26.

[0066]

[0098] Similarly, the signal loop of transistor Q2 flows through the G2 pin assembly 28, then through the bond wire 32 to the gate contact of transistor Q2, where the signal is supplied to transistor Q2. The signal loop flows from transistor Q2 through its source contact. From the source contact, the signal loop flows through another bond wire 32 and directly to the K2 pin assembly 30, passing through the K2 pin assembly 30. As illustrated, this is a true source-Kelvin implementation where the power loop and signal loop are completely independent.

[0067]

[0099] The signal loop in Figure 11 is just one embodiment. As shown in Figure 12, other embodiments may include additional signal traces 54 at the top edge of the substrate 14. In such embodiments, one set of bond wires 32 first connects the gate and source contacts of the transistor to the additional signal traces 54, and a second set of bond wires 32 connects these additional signal traces 54 to appropriate pin assemblies 24-30 (G1, G2, K1, K2). The latter configuration simplifies the implementation of the signal pins, but it significantly increases the required substrate area and can lead to increased costs. Ultimately, the layout is flexible enough to be compatible with both, and each embodiment can be enhanced or optimized for different applications or specifications.

[0068]

[0100] Further problems arise in the mismatch of interconductance between parallel devices. This occurs. Transconductance is essentially the current gain of a device and corresponds to the relationship between the output current and the input voltage. During switching, the input voltage rises, and consequently, the output current also rises. This is common in silicon carbide power devices, but if there is a difference in transconductance between devices connected in parallel, each device will have slightly different on-characteristics. Because different currents flow through the devices, each device is supplied with a slightly different voltage. This voltage mismatch generates a "balancing current" that flows between the devices during switching.

[0069]

[0101] This leveled current is the smallest possible current that could pass through the signal loop instead of the power loop. It prefers an impedance-based path. Similar to interference issues between coupled power loops and signal loops, this leveling current can affect switching quality. Since signal loops are not designed to carry high currents, this uncontrolled high current flowing into the signal loop can lead to reliability problems.

[0070]

[0102] In one embodiment, a metal extending across the source pad on the upper side of the device Very low inductance is found across the sheet. These paths are shown in Figure 13. In comparison, the effective path length and cross-sectional area of ​​the source-coupled path have a relatively high impedance. In practice, the leveled current flows through the power contacts and does not interfere with the signal.

[0071]

[0103] Referring to Figures 14A to 14D, the package is transfer molded. The power module is encased in a protective plastic or epoxy housing 12 by compression molding, injection molding, or a similar process. Several notable features of the housing 12 are highlighted in Figures 14A–14D and discussed below. As shown in Figure 14B, the back metal of the power substrate 14 is exposed on the underside of the power module 10 and provides a thermal pad 56. The thermal pad 56 is used as a thermal contact surface for removing heat from the power module 10. The thermal pad 56 can be sintered, soldered, epoxidized, or similarly attached to a heat sink or cold plate (not shown) to further assist in removing waste heat from the power module 10.

[0072]

[0104] The characteristics of the housing may vary depending on the manufacturing method. (See Figures 14A to 14D) The embodiment represents the structural features of transfer molding. Four hold-down pin vestiges 57 are shown, but the overall size of the power module 10 is not shown. Depending on the circumstances, there may be more or less. Retaining pins (not shown) directly press down on the power substrate during the transfer molding process to limit the amount of plastic bleed or flash on the exposed portion of the thermal pad 56. This ensures that there is no debris on the hot surface and that heat is efficiently dissipated. There are also ejector marks 58 around the housing 12. Ejector marks 58 are small indentations made by ejector pins (not shown) used to remove the power module 10 from the mold (not shown) while it is still hot. The specific location and associated shape of these features will vary depending on the specific product size and implementation.

[0073]

[0105] Clearance and creepage can be important aspects for high-voltage products. The clearance between conductors at a potential is the shortest direct path through the air between the conductors. The creepage is the shortest direct path along the surface between the conductors. Meeting safety standards is difficult and often incompatible with the manufacturing method (tooling, epoxy flow, etc.) and product size (installation area and power density). Achieving proper leveling is difficult in small transfer-molded packages, especially thin, high-voltage SiC-based products.

[0074]

[0106] In certain embodiments, the clearance distance is appropriate and within standards. To increase the distance and, correspondingly, the maximum allowable voltage, creepage extensions 60 are used. Creepage extensions 60 are grooves, ripples, or other surface enhancements that extend the surface distance between conductors at different potentials. As illustrated, creepage extensions 60 are incorporated as part of the plastic or epoxy housing 14, providing special functionality without additional cost. Figures 14C and 14D show one implementation of these features on the housing 12 of the power module 10. Depending on the specific design implementation, other patterns are possible on the top and bottom surfaces.

[0075]

[0107] To minimize the length of the power loop, V-terminal assembly 18 and M Some or all of the edge power contacts for the ID terminal assembly 20 are compared to the signal contacts such as pin assemblies 24, 26, 28, 30, etc., as shown in Figure 15, in the housing 1 It can be inserted from the edge of 2. The signal contacts provided by pin assemblies 24, 26, 28, and 30 require more space to better accommodate the bond wires 32 from the device. Therefore, their housing portions extend outward from the edges of the entire housing 12. This contoured feature allows for optimization of the inductance of each of the independent power loops and signal loops.

[0076]

[0108] Pin assemblies 24, 26, 28, and 30 are used to house the devices in parallel. They extend along horizontal strips. Externally, there are several ways to form contact pins, which are attached to gate drivers, wires, etc., on printed circuit boards. Several variations are shown in Figures 16A to 16D. For simplicity and clarity, only pin assemblies 28 and 30 are discussed, but the same concepts apply to pin assemblies 24 and 26.

[0077]

[0109] The first approach is shown in Figure 16A, where pin assemblies 28 and 30 are As described above, they are U-shaped and concentric. In these embodiments, the legs of the pins emerge from each side of the housing and bend upward at an angle between 87 and 93 degrees toward the upper end of the housing.

[0078]

[0110] The first approach utilizes the symmetry of the product. Pin assemblies 28 and 30 are Depending on where it exits the housing 12, the hole 30H in the pin bar 30B of the outer pin assembly 30 provides tension relief. The second approach provided in Figure 16B does not include a hole for tension relief. Instead, the U-shaped bend of the pin assemblies 28, 30 is U-shaped, allowing a portion of the housing 12 to be present on the pin, so tension relief is specific to the pin bar 30B. In other approaches, three pins can be used, as shown in Figures 16C and 16D. In these approaches, the outer pin assembly 28 remains U-shaped with two legs 28L. However, the centrally positioned inner pin assembly 30 has only a single leg 30L. The bar 30B of the pin assembly 30 can take substantially any shape, such as the angular or triangular shape in Figure 16C, or the T-shape in Figure 16D.

[0079]

[0111] Depending on the specific needs of the end system and the format of its gate driver Therefore, there are even more variations of pin assemblies to consider. The exemplary embodiments are developed with modularity and flexibility in mind, allowing for a large number of potential product variations.

[0080]

[0112] Other pin deformations are illustrated in Figures 17A and 17B, by pin assembly This includes trimming a portion of the legs from pin assemblies 24, 26, 28, and 30. For example, one leg may be removed from pin assemblies 24, 26, 28, and 30 so that the gate and / or source-Kelvin drivers on the PCB can use only two contacts (in contrast to the four in the previous embodiment). The asymmetric approach helps to maximize the amount of metal area used by the external bus routing. In Figure 17A, the inner pin assemblies 26 and 30 each have both legs 26L and 30L respectively. The outer pin assemblies 24 and 28 have one leg that has been trimmed so that only one leg 24L and 28L remains for each pin assembly 24 and 28. In Figure 17B, both the inner pin assemblies 26 and 30 and the outer pin assemblies 24 and 28 have one leg that has been trimmed so that only one leg 24L, 26L, 28L, and 30L remains for each pin assembly 24, 26, 28, and 30.

[0081]

[0113] As described above, the terminals and pin assemblies 18-30 are connected to the lead frame 44 Formed from and combining functions, it provides high-current internal interconnects, bond wire positions, and external terminal contact surfaces. Part or component of the lead frame 44 is transistor Q1, The lead frame 44 is attached to both the upper side source pad of Q2 and the substrate 14. The lead frame 44 can be attached to various components by several methods, including soldering, sintering, conductive epoxy, laser welding, and ultrasonic welding. As illustrated in Figure 18, surface reinforcement features such as holes, slots, and feathered edges are referred to as "solder or epoxy catches" and can be used to enhance the strength of the bond.

[0082]

[0114] Strips on the lead frame 44 that are directly attached to the upper side source pads. It can have several distinctive features. Depending on the specific layout of the device being packaged, there are various solder catch implementations. Ripples (not shown) can also be included between the devices for stress relief due to thermal expansion and for enhanced molding flow. As a further means of stress relief, various bends of the lead frame 44 can be used.

[0083]

[0115] Outside the power module 10, terminals and pin assemblies 18-30 are connected to the busbar. These are attached to wires, printed circuit boards, etc. Vibrations within the system may cause the terminals and pin assemblies 18-30 to be pulled. It is desirable that these external forces not push or pull the power devices or bond wires. For this purpose, holes and / or other retaining features are provided in the lead frame 44 as needed, so that when pulled, the molded compound filling these holes, rather than the sensitive internal components, is subjected to strain.

[0084]

[0116] The holes 62 and / or other retaining functions of the lead frame 44 are transfer components. They are positioned to align with the location of the retaining pins used in the molding process. Ideally, these pins would directly press against the substrate. These holes 62 provide clearance so that the pins can achieve this. They also serve as tension relief after the assembly has been molded.

[0085]

[0117] To save costs, the lead frame 44 is etched or stamped. It is manufactured from sheet metal in one of the manufacturing processes. An example of this is shown in Figures 19A and 19B. Contact and internal functions are joined to the external frame by narrow tabs. To streamline processing in panels and magazines, much of the sheet metal is initially flat. Only the internal bends are formed. During the manufacturing of the product, due to the multiple heating processes required for assembly, thermal expansion slots are added to divide large copper areas. These limit the expansion and warping of the assembly.

[0086]

[0118] The lead frame 44 is attached to the power device and the substrate, and wire bond After being formed, it is separated from the outer frame at the location of the joining tab. The bends of the external contacts are often formed by bending through a procedural step and selective trimming.

[0087]

[0119] For automated mass-produced products, these lead frames 44 are often... The lead frames are patterned as shown. These arrays are handled by multiple machines and are often loaded from magazines or racks. Holes on the top and bottom edges are used for fixing, positioning, keying, and handling. An exemplary lead frame array 64 having four lead frames 44 is illustrated in Figure 20. Specific features of the lead frames 44 and lead frame array 64 vary depending on the product configuration, product size variations, and type of manufacturing equipment.

[0088]

[0120] The potential advantages of the illustrated embodiments include power dissipation in a wide range of systems and applications. To best meet rational and budgetary requirements, the main layout can be scaled up or down. Power module 10 can be scaled up or down by parametrically extending the relevant dimensions. This allows for various combinations of device width and length, and a variety of numbers of transistors. In particular, scaling the power module 10 in this way does not diminish or limit the core advantages of the basic packaging approach. Examples of scalability are shown in Figures 5 and 21, where Figure 5 illustrates a power module 10 having three transistors Q1(16) and three transistors Q2(16), and Figure 21 illustrates a laterally stretched power module 10 having six transistors Q1(16) and six transistors Q2(16).

[0089]

[0121] In a particular embodiment, a specific product tool required to manufacture the component To minimize the number of components, a shared set of materials is desirable. Therefore, an alternative form of scalability is to maintain the same substrate and leadframe layout and adjust the number or size of devices within a set footprint. For example, in some cases (high current), the width of the devices can be increased, and in other cases (low cost), the width can be decreased. Positions can also be removed to reduce the maximum power handling for a fully mounted power module 10. Examples are provided in Figures 22A and 22B. Both power modules 10 in Figures 22A and 22B are stretched laterally compared to the one provided in Figure 5 so that they have five positions for transistor Q1(16) and five positions for transistor Q2(16). Power module 10 in Figure 22A is fully mounted with five transistors Q1(16) and five transistors Q2(16). Power module 10 in Figure 22B is mounted with three transistors Q1(16) and three transistors Q2(16). Therefore, the two locations in Figure 22B (the unimplemented location 70) are intentionally left unimplemented, and assuming the same type of component is applied in both scenarios, this could correspond to a 40% reduction in power handling compared to the case in Figure 22A.

[0090]

[0122] Scalability features enable optimization within the package. It is also helpful to provide a design that can be expanded or optimized from the base. The half-bridge legs of the power module 10 can be arranged to form many topological variations. In most cases, each of the V- terminal assembly 18 and V+ terminal assembly 20 is connected to the same low-inductance bus. The intermediate terminal assembly 22 or AC output is either (1) connected to a parallel package for high current, (2) kept isolated for each individual bridge leg, or (3) has a combination of both.

[0091]

[0123] Figure 23 shows the V-terminal assembly of three power modules 10A, 10B, and 10C. The diagram illustrates an example of a parallel configuration using stacked bus wiring, where the V+ terminal assembly and the MID- terminal assembly are connected in parallel to the elongated V- bus (not shown), the elongated V+ bus 72, and the elongated MID bus 74, respectively. The number of parallel power modules 10X can be increased or decreased to appropriately or optimally match the power requirements of the system. This feature allows the same core product to be used in a cost-effective manner in many systems across all power levels.

[0092]

[0124] Figure 24 shows how to form a single full H-bridge circuit using appropriate bus wiring. An example of two half-H bridge power modules 10A and 10B connected in this manner is shown. As illustrated, the V-terminal assemblies (not shown) and V+ terminal assemblies 22 of the two power modules 10A and 10B are connected in parallel to elongated V-buses (not shown) and elongated V+ buses 72, respectively. The MID-terminal assembly 20 of power module 10A is provided with a first MID-bus 74A, and the MID-terminal assembly 20 of power module 10B is provided with a second MID-bus 74B.

[0093]

[0125] Figure 25 shows a three-phase topolo with three bridge legs, for applying multilayer bus wiring. The diagram illustrates the following. Three power modules 10A, 10B, and 10C are provided. The V-terminal assemblies (not shown) and V+ terminal assemblies 22 of power modules 10A, 10B, and 10C are connected in parallel to elongated V-buses (not shown) and elongated V+ buses 72, respectively. A first MID-bus 74A is provided for the MID-terminal assembly 20 of power module 10A, a second MID-bus 74B is provided for the MID-terminal assembly 20 of power module 10B, and a third MID-bus 74C is provided for the MID-terminal assembly 20 of power module 10C.

[0094]

[0126] The concepts presented in Figures 23 and 24 can be combined. Figure 26 is The diagram shows a configuration that applies stacked bus wiring to provide three bridge legs, each with two power modules 10 connected in parallel. Specifically, using three MID buses 74A, 74B, and 74C, power modules 10A and 10B are connected in parallel to the first leg, power modules 10C and 10D are connected in parallel to the second leg, and power modules 10E and 10F are connected in parallel to the third leg.

[0095]

[0127] Silicon carbide (SiC) power devices offer high voltage blocking, low on-resistance, and high current handling. It offers a high level of performance advantages, including high-speed switching, low switching losses, high junction temperature, and high thermal conductivity. Ultimately, these characteristics significantly increase the potential power density, which is the power processed per unit area or volume.

[0096]

[0128] However, achieving this possibility requires package and system level work. Significant challenges must be addressed. Higher voltages, currents, and switching speeds manifest as extremely high physical stresses applied to smaller, more confined areas. To fully utilize what SiC technology offers, one or more of the following challenges must be addressed. • Provides a common circuit topology both within the package (internal layout) and outside the package (interconnections). • Removes waste heat from the device due to conduction losses and switching losses. • Provides effective electrical insulation between high voltage potentials. • Provides low power loop inductance to minimize high-voltage overshoot during high-speed switching. • Achieve low signal loop inductance to minimize gate voltage overshoot and oscillation. • Optimize the internal layout for parallelization of power devices to achieve dynamic and steady-state current sharing. • Provides low power loop resistance to allow high current to flow without overheating. • Provides an external terminal arrangement suitable for parallel connection of modules, characterized by easy placement into circuit topologies. • Provides a leveled arrangement of power devices.

[0097]

[0129] The internal layout or physical placement of package components is a key factor in these requirements. Each of these factors has a significant impact. As the number of devices inside a package increases, achieving an optimal layout becomes increasingly difficult. Parallel connections are a common technique for SiC devices to improve the current capability of a package. Connecting more devices in parallel makes it increasingly difficult to level the trade-offs between thermal diffusion, power loop inductance, signal loop inductance, and package size. Forming a half-bridge topology further increases the layout challenges, as critical parameters such as power loop inductance and even heat transfer between switch locations become even more of a design challenge.

[0098]

[0130] In addition to performance, the cost is kept low to appeal to a wide range of markets and applications. It should be reduced. Some techniques that can help reduce costs include: • By providing multiple functionalities from the same component, the use of individual components is restricted. • Optimize the function and performance of each component through design. • Limit the requirements for secondary or termination actions. • Use conventional or established manufacturing methods known for high yields. • If possible, use batch or continuous processing with panels, strips, arrays, magazines, etc. • Optimize package size and shape based on the manufacturing method of subcomponents, such as determining the size of parts manufactured in strips or panels and making the most of their raw materials.

[0099]

[0131] Ultimately, the combination of internal scalability and external modularity is a wide range of possibilities. This results in a highly adaptable core layout that can be applied to system requirements.

[0132] This disclosure relates to, but is not limited to, the following: • Highly optimized half-bridge package design for next-generation SiC products. • A scalable layout that allows products to be implemented by lengthening or widening the package to enable more SiC areas (through larger devices or more parallelization). A modular approach to external terminal locations to facilitate parallel connection of multiple packages or placement in a common circuit topology. • Ultra-low inductance, leveled power loop layout. • Low inductance, leveled signal loop layout. • True Kelvin implementation of signal loops. • Compatibility of clockwise or counterclockwise signal pins. • Cost reduction by minimizing the number of proprietary parts used. • Cost reduction through minimizing the area of ​​the power board. • Cost reduction through read frame array processing. • High manufacturability using commonly employed lead frame array processing and transfer molding. • Voltage creepage extensions molded onto the top and bottom sides of the package. • Direct power connection to the top side of the device on the lead frame.

[0100]

[0133] The concepts provided above address one, some, or all of the above. This provides a unique and novel power module 10. Those skilled in the art will recognize improvements and modifications to this disclosure. All such improvements and modifications are considered to be within the scope of the concepts disclosed herein.

Claims

1. It is a power module, A substrate having an upper surface having a first trace and a second trace, A plurality of first vertical power devices and a plurality of second vertical power devices electrically coupled to form part of a power circuit, A first terminal assembly comprising a first elongated bar, at least two first terminal contacts, and at least two first terminal legs extending between different points of the first elongated bar and at least two of the first terminal contacts, The device comprises a second elongated bar, at least two second terminal contacts, and a second terminal assembly having at least two second terminal legs, each extending between different points of the second elongated bar and at least two of the second terminal contacts, The first plurality of vertical power devices are electrically and mechanically directly coupled between the first trace and the bottom of the first elongated bar of the first terminal assembly. The second plurality of vertical power devices are power modules, in which the second traces are directly electrically and mechanically coupled between the bottom of the second elongated bar of the second terminal assembly.

2. The power module according to claim 1, further comprising a third terminal assembly and a fourth terminal assembly electrically and mechanically coupled to the first trace adjacent to the opposing side surface of the substrate.

3. The power module according to claim 2, wherein the substrate has four sides, the third terminal assembly is on the first side, the fourth terminal assembly is adjacent to the second side facing the first side, the first terminal assembly is adjacent to the third side between the first side and the second side, and the second terminal assembly is between the first side and the second side and is adjacent to the fourth side facing the third side.

4. The power module according to claim 1, comprising a housing that encapsulates at least a portion of the first terminal assembly and the second terminal assembly.

5. Each of the at least two of the first terminal legs extends outward from the side of the housing, and at least two of the first terminal contacts extend above the upper end of the housing and overlap so as to be parallel to the upper end of the housing. The power module according to claim 4, wherein each of the at least two of the second terminal legs extends outward from the side of the housing, and at least two of the second terminal contacts extend above the upper end of the housing and overlap so as to be parallel to the upper end of the housing.

6. The power module according to claim 5, further comprising a third terminal assembly and a fourth terminal assembly electrically and mechanically coupled to the first trace adjacent to an opposing side surface of the substrate, wherein the substrate has four sides, the third terminal assembly is adjacent to the first side, the fourth terminal assembly is adjacent to the second side opposite to the first side, the first terminal assembly is adjacent to the third side between the first side and the second side, and the second terminal assembly is between the first side and the second side and is adjacent to the fourth side opposite to the third side.

7. The third terminal assembly comprises a third terminal leg extending outward from the side of the housing and a third terminal contact extending above the upper end of the housing and parallel to the upper end of the housing. The power module according to claim 6, wherein the fourth terminal assembly comprises a fourth terminal leg extending outward from the side of the housing and a fourth terminal contact extending above the upper end of the housing and parallel to the upper end of the housing.

8. The power module according to claim 5, wherein the upper surface of the housing is provided with a plurality of grooves that function as creepage extensions that effectively extend the surface distance between specific conductive elements of the power module.

9. The power module according to claim 1, wherein the first elongated bar and at least two of the first terminal legs of the first terminal assembly form a U-shape, and the second elongated bar and at least two of the second terminal legs of the second terminal assembly form a U-shape.

10. A first pin assembly comprising a first pin bar and at least one first pin leg extending from the first pin bar, wherein the first pin bar is positioned adjacent to the first elongated bar and between at least two of the first terminal legs, The power module according to claim 9, further comprising a second pin assembly comprising a second pin bar and at least one second pin leg extending from the second pin bar, wherein the second pin bar is positioned adjacent to the second elongated bar and between at least two of the second terminal legs.

11. At least one of the first pin legs comprises two first pin legs, and at least one of the second pin legs comprises two second pin legs, and the power module further comprises A third pin assembly comprising a third pin bar and at least one third pin leg extending from the third pin bar, wherein the third pin bar is adjacent to the first pin bar and positioned between two of the first pin legs, A power module according to claim 10, comprising a fourth pin assembly comprising a fourth pin bar and at least one fourth pin leg extending from the fourth pin bar, wherein the fourth pin bar is adjacent to the second pin bar and positioned between two of the second pin legs.

12. The power module according to claim 11, wherein at least one of the third pin legs comprises two third pin legs, and at least one of the fourth pin legs comprises two fourth pin legs.

13. The power module according to claim 11, wherein the first pin assembly is electrically connected to the first contacts of the first plurality of vertical power devices via a first bond wire, the second pin assembly is electrically connected to the second contacts of the second plurality of vertical power devices via a second bond wire, the third pin assembly is electrically connected to the third contacts of the first plurality of vertical power devices via a third bond wire, and the fourth pin assembly is electrically connected to the fourth contacts of the second plurality of vertical power devices via a fourth bond wire.

14. The system comprises a housing that encapsulates at least a portion of the first terminal assembly, the second terminal assembly, the first pin assembly, and the second pin assembly, wherein at least one of the first pin legs and at least one of the second pin legs extend outward from the respective side portions of the housing and then toward the upper end of the housing. The power module according to claim 11, which is bent upward at an angle of 87 to 93 degrees.

15. The first plurality of vertical power devices and the second plurality of vertical power devices are field-effect transistors, The first pin assembly is electrically coupled to one of the gate contacts or source contacts of the first plurality of vertical power devices. The power module according to claim 11, wherein the second pin assembly is electrically coupled to one of the gate contacts or source contacts of the second plurality of vertical power devices.

16. The third pin assembly is electrically coupled to the other of the gate contacts or source contacts of the first plurality of vertical power devices. The power module according to claim 15, wherein the fourth pin assembly is electrically coupled to the other of the gate contacts or source contacts of the second plurality of vertical power devices.

17. The power module according to claim 1, wherein the first plurality of vertical power devices comprises at least three first vertical transistors electrically coupled in parallel with each other, and the second plurality of vertical power devices comprises at least three second vertical transistors electrically coupled in parallel with each other.

18. The power module according to claim 17, wherein at least three of the first vertical transistors and at least three of the second vertical transistors are silicon carbide transistors, and the substrate comprises silicon carbide.

19. The power module according to claim 1, wherein the first plurality of vertical power devices and the second plurality of vertical power devices each comprise a power field-effect transistor, and the power circuit is a half-H bridge circuit.

20. The power module according to claim 1, wherein the first terminal assembly further comprises a plurality of jumpers extending from the first elongated bar to the second trace, the plurality of jumpers being electrically and mechanically connectable to the second trace.

21. The power module according to claim 1, wherein the first terminal assembly and the second terminal assembly are components of a common lead frame.

22. The power circuit comprises a power loop and at least one signal loop. The power module according to claim 1, wherein the power loop passes through the first plurality of vertical power devices and the second plurality of vertical power devices.

23. The power module according to claim 22, wherein the power loop is independent of at least one of the signal loops.

24. The power module according to claim 23, wherein at least one signal loop provides at least one control signal to the first plurality of vertical power devices or the second plurality of vertical power devices.

25. The power module according to claim 22, wherein the power loop does not pass through the bond wires of the power module.

26. Both the first terminal assembly and the second terminal assembly are at least one The power module according to claim 1, which is symmetrical along an axis.

27. The power module according to claim 1, wherein the substrate, the first plurality of vertical power devices, and the second plurality of vertical power devices are each made of silicon carbide.

28. It is a power module, A substrate having an upper surface having a first trace and a second trace, A plurality of first vertical power devices and a plurality of second vertical power devices electrically coupled to form part of a power circuit, A first terminal assembly comprising a first elongated bar, at least two first terminal contacts, and at least two first terminal legs extending between different points of the first elongated bar and at least two of the first terminal contacts, A second terminal assembly comprising a second elongated bar, at least two second terminal contacts, and at least two second terminal legs extending between different points of the second elongated bar and at least two of the second terminal contacts, A third terminal assembly and a fourth terminal assembly are electrically and mechanically coupled to the first trace located adjacent to the opposing side surface of the substrate, The substrate comprises a housing that encapsulates at least a portion of the first terminal assembly, the second terminal assembly, the third terminal assembly, and the fourth terminal assembly, the substrate having four sides, the third terminal assembly being on the first side, the fourth terminal assembly being adjacent to the second side facing the first side, the first terminal assembly being adjacent to the third side between the first and second sides, and the second terminal assembly being between the first and second sides and adjacent to the fourth side facing the third side. The first plurality of vertical power devices are electrically and mechanically directly coupled between the first trace and the bottom of the first elongated bar of the first terminal assembly. The second plurality of vertical power devices are power modules, in which the second traces are directly electrically and mechanically coupled between the bottom of the second elongated bar of the second terminal assembly.

29. Each of the at least two of the first terminal legs extends outward from the side of the housing, and at least two of the first terminal contacts extend above the upper end of the housing and overlap so as to be parallel to the upper end of the housing. The power module according to claim 28, wherein each of the at least two of the second terminal legs extends outward from the side of the housing, and at least two of the second terminal contacts overlap above the upper end of the housing, parallel to the upper end of the housing.

30. The third terminal assembly comprises a third terminal leg extending outward from the side of the housing and a third terminal contact extending above the upper end of the housing and parallel to the upper end of the housing. The power module according to claim 29, wherein the fourth terminal assembly comprises a fourth terminal leg extending outward from the side of the housing and a fourth terminal contact extending above the upper end of the housing and parallel to the upper end of the housing.

31. A first pin assembly comprising a first pin bar and at least one first pin leg extending from the first pin bar, wherein the first pin bar is positioned adjacent to the first elongated bar and between at least two of the first terminal legs, A second pin bar and at least one second pin rail extending from the second pin bar The power module according to claim 30, further comprising a second pin assembly comprising a second pin bar, wherein the second pin bar is positioned adjacent to the second elongated bar and between at least two of the second terminal legs.

32. At least one of the first pin legs comprises two first pin legs, and at least one of the second pin legs comprises two second pin legs, and the power module further comprises A third pin assembly comprising a third pin bar and at least one third pin leg extending from the third pin bar, wherein the third pin bar is adjacent to the first pin bar and positioned between two of the first pin legs, A power module according to claim 31, comprising a fourth pin assembly comprising a fourth pin bar and at least one fourth pin leg extending from the fourth pin bar, wherein the fourth pin bar is adjacent to the second pin bar and positioned between two of the second pin legs.

33. The power circuit comprises a power loop and at least one signal loop. The power loop passes through the first plurality of vertical power devices and the second plurality of vertical power devices, The power loop is independent of at least one of the signal loops, The power module according to claim 32, wherein at least one of the signal loops provides at least one control signal to the first plurality of vertical power devices or the second plurality of vertical power devices.

34. The power module according to claim 33, wherein the power loop does not pass through the bond wires of the power module.

35. The power module according to claim 28, wherein the substrate, the first plurality of vertical power devices, and the second plurality of vertical power devices are each made of silicon carbide.

36. It is a power module, A substrate having an upper surface having a first trace and a second trace, A plurality of first vertical power devices and a plurality of second vertical power devices electrically coupled to form part of a power circuit, A first terminal assembly comprising a first elongated bar and at least one first terminal contact coupled to the first elongated bar via at least one first terminal leg, A second terminal assembly comprising a second elongated bar and at least one second terminal contact coupled to the second elongated bar via at least one second terminal leg, The device comprises a housing that encapsulates at least a portion of the first terminal assembly and the second terminal assembly, At least one of the first terminal legs extends outward from the first side portion of the housing, and at least one of the first terminal contacts extends above the upper end of the housing and folds over so as to be parallel to the upper end of the housing. A power module wherein at least one of the second terminal legs extends outward from the second side portion of the housing, and at least one of the second terminal contacts extends above the upper end of the housing and folds over parallel to the upper end of the housing.

37. It is a power module, A substrate having an upper surface having a first trace and a second trace, A first set of multiple vertical power devices electrically coupled to form part of a power circuit and a second set of vertical power devices, A first terminal assembly comprising a first elongated bar, at least two first terminal contacts, and at least two first terminal legs extending between different points of the first elongated bar and at least two of the first terminal contacts, The device comprises a second elongated bar, at least two second terminal contacts, and a second terminal assembly having at least two second terminal legs, each extending between different points of the second elongated bar and at least two of the second terminal contacts, The first terminal assembly and the second terminal assembly are formed from a single lead frame, forming a power module.

38. It is a power module, A substrate having an upper surface having a first trace and a second trace, A plurality of first vertical power devices and a plurality of second vertical power devices electrically coupled to form part of a power circuit, The system comprises a first terminal assembly, a second terminal assembly, a third terminal assembly, and a fourth terminal assembly. The first plurality of vertical power devices are electrically coupled between the first trace and the first terminal assembly, and the second plurality of vertical power devices are electrically coupled between the second trace and the second terminal assembly. A power module having four sides on the substrate, wherein the third terminal assembly is on the first side, the fourth terminal assembly is adjacent to the second side opposite the first side, the first terminal assembly is adjacent to the third side between the first and second sides, and the second terminal assembly is between the first and second sides and is adjacent to the fourth side opposite the third side.

39. It is a power module, A substrate having an upper surface having a first trace and a second trace, A plurality of first vertical power devices and a plurality of second vertical power devices electrically coupled to form part of a power circuit, A first terminal assembly comprising a first elongated bar, at least two first terminal contacts, and at least two first terminal legs extending between different points of the first elongated bar and at least two of the first terminal contacts, A second terminal assembly comprising a second elongated bar, at least two second terminal contacts, and at least two second terminal legs extending between different points of the second elongated bar and at least two of the second terminal contacts, A first pin assembly comprising a first pin bar and at least one first pin leg extending from the first pin bar, The second pin assembly comprises a second pin bar and at least one second pin leg extending from the second pin bar, The first elongated bar and at least two of the first terminal legs of the first terminal assembly form a U-shape. The second elongated bar and at least two of the second terminal legs of the second terminal assembly form a U-shape. The first pin bar is positioned adjacent to the first elongated bar and between at least two of the first terminal legs. A power module wherein the second pin bar is positioned adjacent to the second elongated bar and between at least two of the second terminal legs.

40. At least one of the first pin legs comprises two first pin legs, and at least one of the second pin legs comprises two second pin legs, and the power module Furthermore, A third pin assembly comprising a third pin bar and at least one third pin leg extending from the third pin bar, wherein the third pin bar is adjacent to the first pin bar and positioned between two of the first pin legs, A power module according to claim 39, comprising a fourth pin assembly comprising a fourth pin bar and at least one fourth pin leg extending from the fourth pin bar, wherein the fourth pin bar is adjacent to the second pin bar and positioned between two of the second pin legs.

41. It is a power module, A substrate having an upper surface having a first trace and a second trace, A plurality of first vertical power devices and a plurality of second vertical power devices electrically coupled to form part of a power circuit, The system comprises a first terminal assembly, a second terminal assembly, a third terminal assembly, and a fourth terminal assembly. The first plurality of vertical power devices are electrically coupled between the first trace and the first terminal assembly, and the second plurality of vertical power devices are electrically coupled between the second trace and the second terminal assembly. The substrate has four sides, the third terminal assembly is on the first side, the fourth terminal assembly is close to the second side opposite the first side, the first terminal assembly is close to the third side between the first and second sides, the second terminal assembly is between the first and second sides and close to the fourth side opposite the third side, The first terminal assembly further comprises a plurality of jumpers extending from a first elongated bar to the second trace, the plurality of jumpers electrically connected to the second trace, and a power module located between the third terminal assembly and the fourth terminal assembly.

Images