Power module for high power applications

Abstract

The present disclosure relates to a power module comprising a substrate, a first plurality of vertical power devices and a second plurality of vertical power devices, and a first terminal assembly and a second terminal assembly. The substrate has a top surface with 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 plurality of vertical power devices are electrically and mechanically directly coupled between the first trace and a bottom of a first elongated bar of the first terminal assembly. The second plurality of vertical power devices are electrically and mechanically directly coupled between the second trace and a bottom of a second elongated bar of the second terminal assembly.

Description

Technical Field

[0001] This disclosure relates to power modules for high-power applications. Background Technology

[0002] In high-power applications, multiple components of all or part of the circuitry are typically encapsulated within electronic modules. These modules generally refer to power modules housed in molded housings made of thermoplastic, epoxy, or other materials, which encapsulate the components and circuit boards or substrates on which the components are mounted. Terminal assemblies extending beyond the housing provide input / output connections to the power module, facilitating integration into and connection to other systems. Such systems may include electric vehicles, power conversion and control systems, etc. Summary of the Invention

[0003] This disclosure relates to a power module, comprising: a substrate, a first plurality of vertical power devices and a second plurality of vertical power devices, and a first terminal assembly and a second terminal assembly. The substrate has a top surface with 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 rod, at least two first terminal contacts, and at least two first terminal legs extending between different points of the first elongated rod and the at least two first terminal contacts. The second terminal assembly has a second elongated rod, at least two second terminal contacts, and at least two second terminal legs extending between different points of the second elongated rod and the at least two 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 rod of the first terminal assembly. The second plurality of vertical power devices are thermally, electrically, and mechanically directly coupled between the second trace and the bottom of the second elongated rod of the second terminal assembly.

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

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

[0006] In one embodiment, the housing encapsulates at least a portion of the first terminal assembly and the second terminal assembly. Each of the at least two first terminal legs may extend beyond the sides of the housing and be folded such that at least two first terminal contacts extend parallel to the top portion of the housing over the top portion. Similarly, each of the at least two second terminal legs may extend beyond the sides of the housing and be folded such that at least two second terminal contacts extend parallel to the top portion of the housing over the top portion.

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

[0008] The third terminal assembly may have a third terminal leg and a third terminal contact, the third terminal leg extending beyond the side of the housing, and the third terminal contact extending parallel to the top portion of the housing above it. The fourth terminal assembly may have a fourth terminal leg and a fourth terminal contact, the fourth terminal leg extending beyond the side of the housing, and the fourth terminal contact extending parallel to the top portion of the housing above it.

[0009] The top surface of the housing may have multiple grooves, which serve as creepage extenders to effectively extend the surface distance between specific conductive elements of the power module.

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

[0011] In one embodiment, the power module further comprises: a first pin assembly having a first pin and at least one first pin leg extending from the first pin. The first pin may be adjacent to the first pin and located between at least two first pin legs. A second pin assembly may have a second pin and at least one second pin leg extending from the second pin. The second pin may be adjacent to the second pin and located between at least two second pin legs.

[0012] The at least one first pin leg may have two first pin legs, and the at least one second pin leg may have two second pin legs. In this embodiment, the power module may also have a third pin assembly and a fourth pin assembly. The third pin assembly may have a third pin and at least one third pin leg extending from the third pin, wherein the third pin is adjacent to the first pin and located between the two first pin legs. The fourth pin assembly may have a fourth pin and at least one fourth pin leg extending from the fourth pin, wherein the fourth pin is adjacent to the second pin and located between the two second pin legs.

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

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

[0015] In one embodiment, the power module has: a housing that encapsulates at least a portion of a first terminal assembly, a second terminal assembly, a first pin assembly, and a second pin assembly. The at least one first pin leg and the at least one second pin leg extend beyond the respective sides of the housing and then fold upward toward the top of the housing at an angle between 87 and 93 degrees.

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

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

[0018] In one embodiment, a first plurality of vertical power devices have at least three first vertical transistors electrically coupled to each other in parallel, and a second plurality of vertical power devices have at least three second vertical transistors electrically coupled to each other in parallel. 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.

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

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

[0021] In one embodiment, the first terminal assembly and the second terminal assembly are components that share a 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 the at least one signal loop. The at least one signal loop can 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 any bonding wires of the power module.

[0023] In one embodiment, the first terminal assembly and the second terminal assembly are symmetrical along at least one axis.

[0024] Based on the above, this disclosure relates to a compact, 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. It utilizes a novel layout that integrates a size- and cost-optimized power substrate with a multifunctional copper layer that interconnects the top pads of the devices while also serving as external terminals.

[0025] The design is characterized by scalability and modularity. The layout can be widened and lengthened: to (1) accommodate larger devices; or (2) to place more devices in parallel. Essentially, the packaging concept can be scaled up or down to meet power handling requirements without sacrificing any performance benefits offered by the packaging. These packages are also arranged directly in parallel, thereby increasing the converter current and / or forming topologies such as full-bridge (commonly used in DC-DC power conversion) and three-phase (used in motor drives and inverters).

[0026] Scalability and modularity are distinct aspects of this product design, allowing the platform to support various combinations of provisioning and configuration. As shown below, this disclosure can be scaled up or down to best meet the needs of a specific application.

[0027] Those skilled in the art will recognize the scope of this disclosure and its additional aspects will become apparent upon reading the following detailed description in conjunction with the accompanying drawings. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate several aspects of this disclosure and, together with the description, serve to illustrate the principles of this disclosure.

[0029] Figure 1 A schematic diagram of a typical half-H-bridge circuit is shown.

[0030] Figure 2 It shows Figure 1 The specific implementation method of the half-H bridge circuit in the text.

[0031] Figure 3 This is an isometric view of the external structure of a power module according to a first embodiment of the present disclosure.

[0032] Figure 4 This is an isometric view of the internal structure of the first embodiment of this disclosure.

[0033] Figure 5 This is a top view of the internal structure of the first embodiment of this disclosure.

[0034] Figure 6 This is an exploded view of the first embodiment of this disclosure.

[0035] Figure 7 This is a top view of the internal structure of an alternative embodiment of this disclosure.

[0036] Figure 8 An exemplary power circuit of a first embodiment of this disclosure is shown.

[0037] Figure 9A A first embodiment of a terminal connection to a low-inductance busbar according to the present disclosure is shown.

[0038] Figure 9B A first embodiment of the terminal connection to the upper layer of the low-inductance bus according to the present disclosure is shown.

[0039] Figure 9C A second embodiment of the terminal connection to the upper layer of the low-inductance bus according to the present disclosure is shown.

[0040] Figure 10A A second embodiment of the terminal connection to the low-inductance busbar layer according to the present disclosure is shown.

[0041] Figure 10B A third embodiment of the terminal connection to the upper layer of the low-inductance busbar according to the present disclosure is shown.

[0042] Figure 11 An exemplary signal loop according to a first embodiment of the present disclosure is shown.

[0043] Figure 12Direct bonding of a power substrate according to one embodiment of the present disclosure is shown.

[0044] Figure 13 The diagram illustrates the current balancing path between devices due to transconductance mismatch.

[0045] Figure 14A and Figure 14B These are front isometric views and rear isometric views of the outer housing of a power module according to an embodiment of the present disclosure.

[0046] Figure 14C and Figure 14D yes Figure 14A and Figure 14B Top view and cross-sectional view of the external housing of the power module.

[0047] Figure 15 The outline of a power module housing according to one embodiment of the present disclosure is shown.

[0048] Figure 16A , Figure 16B , Figure 16C as well as Figure 16D Various examples of signal pin components according to this disclosure are shown.

[0049] Figure 17A and Figure 17B An example of signal pin trimming according to this disclosure is shown.

[0050] Figure 18 A lead frame feature according to an embodiment of the present disclosure is shown.

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

[0052] Figure 20 An embodiment of a leadframe array according to the present disclosure is shown.

[0053] Figure 21 A major variation of the power module according to this disclosure is shown.

[0054] Figure 22A and Figure 22B The full power distribution module and the partial power distribution module according to this disclosure are shown.

[0055] Figure 23 An example is shown of parallel power modules with a laminated bus forming a higher power half-bridge according to an embodiment of the present disclosure.

[0056] Figure 24 A power module arranged in a full-bridge topology according to one embodiment of the present disclosure is shown.

[0057] Figure 25 A power module arranged in a three-phase topology according to one embodiment of the present disclosure is shown.

[0058] Figure 26 A power module is shown in a three-phase topology arranged such that each leg has two power modules connected in parallel, according to an embodiment of the present disclosure. Detailed Implementation

[0059] The embodiments described below illustrate necessary information enabling those skilled in the art to implement the embodiments and demonstrate the best mode for implementing the embodiments. When reading the following description in conjunction with the accompanying drawings, those skilled in the art will understand the concepts of this disclosure and will recognize that the application of these concepts is not specifically addressed herein. It should be understood that these concepts and applications fall within the scope of this disclosure and the appended claims.

[0060] It should be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be defined as a second element, and likewise, a second element may be defined as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0061] It should be understood that when a component, such as a layer, region, or substrate, is referred to as being "on" or extending "on" another component, it can be directly on or directly extending to the other component, or intermediate components may be present. Conversely, when a component is referred to as being "directly on" or extending "directly on" another component, no intermediate components are present. Similarly, it should be understood that when a component, such as a layer, region, or substrate, is referred to as being "above" or extending "above" another component, it can be directly above or extending directly above the other component, or intermediate components may be present. Conversely, when a component is referred to as being "directly above" or extending "directly above" another component, no intermediate components are present. It should also be understood that when a component is referred to as being "connected" or "coupled" to another component, it can be directly connected or coupled to the other component, or intermediate components may be present. Conversely, when a component is referred to as being "directly connected" or "directly coupled" to another component, no intermediate components are present.

[0062] In this document, relative terms such as “below,” “above,” “over,” “below,” “horizontal,” or “vertical” may be used to describe the relationship between one element, layer, or region shown in the figure and another element, layer, or region. It should be understood that these terms, along with those discussed above, are intended to cover different orientations of the device other than those depicted in the figures.

[0063] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that, when used herein, the terms “comprises,” “comprising,” “includes,” and / or “including” specify the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0064] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be further understood that the terms used herein shall be interpreted as having the same meaning as they have in the context of this specification and in the relevant technical field, and shall not be interpreted in an idealized or excessive form unless expressly defined herein.

[0065] This disclosure relates to power modules used in high-power applications. A power module may contain 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), diodes, etc. 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 six-packs.

[0066] In the following discussion, the half-bridge circuit is used to facilitate understanding of the packaging concept disclosed herein. The basic half-H-bridge circuit is a common power circuit used to switch different voltages on a load, such as… Figure 1The motor is shown in the diagram. The key components of the half-H-bridge circuit are the high-side transistor Q1 and the low-side transistor Q2, which are coupled in series between the V+ and V- terminals. For example, assume that transistors Q1 and Q2 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 coupled together and represent the MID terminal, which is essentially the output node connected to the load (not shown).

[0067] To increase power carrying capacity, multiple power devices can be coupled in parallel with each other. In the illustrated embodiment, and as shown... Figure 2 The transistor Q1 is represented by three transistors Q1', Q1" and Q1"' coupled in parallel, and the transistor Q2 is represented by three transistors Q2', Q2" and Q2"' coupled in parallel. For simplicity and readability, the parallel transistors Q1', Q1" and Q1"' can be collectively referred to as transistor Q1, and the transistors Q2', Q2" and Q2"' can be collectively referred to as transistor Q2. In this example, transistors Q1 and Q2 are vertical N-channel MOSFETs, wherein the drain contact is located on the bottom of the device, and the source, gate, and source-Kelvin contact are located on the top of the device. This is implemented in the power module embodiment described below. Figure 2 The half-H-bridge circuit in the middle, however, Figure 2 The half-H-bridge circuit described here is just one type of circuit among many that benefit from the ideas presented in this paper.

[0068] According to the first embodiment, in Figure 3 , Figure 4 , Figure 5 ,as well as Figure 6 An exemplary power module 10 is shown in the figure. Figure 3 It is an isometric view of a power module 10 having a moldable housing 12. Figure 4 and Figure 5 This is an isometric view and plan view of the power module 10 without encapsulated molding housing 12. Figure 6 This is an exploded view of power module 10. The following descriptions are for reference only. Figure 3 , Figure 4 , Figure 5 ,as well as Figure 6 Each image in the series.

[0069] The substrate 14 is located at the core of the power module 10, and the power device 16 is mounted on the top surface of the substrate 14. In this embodiment, the power device 16 is transistors Q1 (i.e., Q1', Q1”, Q1”') and Q2 (i.e., Q2', Q2”, Q2”'). A first terminal assembly (referred to as V-terminal assembly 18) is mounted above transistor Q2 (16) located near the A side of the power module 10. The V-terminal assembly 18 is conductive and is directly attached to the source contact located on the top side of transistor Q2 to form Figure 2 V-nodes in the context of V-nodes.

[0070] Two opposing terminals (referred to as V+ terminal assembly 22) are mounted near the C and D sides to the first trace / pad 34 located on the top surface of the substrate 14. Figure 6 Transistor Q1 is mounted on substrate 14 such that its drain is directly attached to the first trace / pad 34. Therefore, the drain of transistor Q1 forms a junction with V+ terminal assembly 22. Figure 2 The V+ node in the middle.

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

[0072] The gate contact and source-Kelvin contact (G1, K1) of transistor Q1 are electrically coupled to pin assemblies 24 and 26, respectively, using bonding wire 32. Similarly, the gate contact and source-Kelvin contact (G2, K2) of transistor Q2 are electrically coupled to pin assemblies 28 and 30, respectively, using bonding wire 32. Pin assemblies 24, 26, 28, and 30 are directly mounted to the top surface of substrate 14 to electrically isolate the pin assemblies from each other and from the high-power V-, V+, and MID nodes. Details regarding the design and shape of pin assemblies 24, 26, 28, 30, V- terminal assembly 18, the corresponding MID- terminal assembly 20, and V+ terminal assembly 22 are further provided below. It should be noted that this design may include additional pins or pin assemblies providing input or output nodes for the electronics supplied to the power module 10. These additional pins and pin assemblies can be used for current sensing, temperature sensing, biasing, etc.

[0073] For reference Figure 6An exploded view of the power module 10. Starting from the bottom of the figure, power devices 16, including transistors Q1 and Q2, are attached to the first trace 34 and the second trace 36 at mounting position 38 using device attachment material 40. Device attachment material 40 may be solder, adhesive, sintered metal, etc., providing mechanical structure, high current interconnection, and high thermal conductivity.

[0074] Pin assemblies 24, 26, 28, 30, V-terminal assembly 18, MID-terminal assembly 20, and V+ terminal assembly 22 form a single leadframe 44. The top portion of the substrate 14 and the power device 16 are connected to the corresponding bottom portions of the V-terminal assembly 18, MID-terminal assembly 20, and V+ terminal assembly 22 using leadframe attachment material 42. The leadframe attachment material can be solder, adhesive, sintered metal, laser solder, ultrasonic solder, etc., providing mechanical structure, high current interconnection, and high thermal conductivity. The leadframe 44 is typically a metal contact strip for high-current external connections and internal interconnections. Any contacts are joined together on a single sheet, typically with multiple products per sheet, and are processed into an array before forming and separation.

[0075] The bonding wire 32 is typically used to connect the control contacts of the power device 16 to the various pin assemblies 24, 26, 28, 30. The bonding wire 32 can be a large-diameter wire capable of ultrasonic or thermoacoustic bonding for electrical interconnects that can support relatively high currents. Alternatively, the pin assemblies 24, 26, 28, 30 can be directly bonded to the power device 16, traces on the substrate 18, etc.

[0076] The housing 12 can be formed using transfer or injection molding processes to provide mechanical structure and high voltage isolation. The housing 12 encapsulates the internal components of the power module 10. The molding compound used for the housing 12 can be a transfer or compression molding epoxy molding compound (EMC) capable of providing mechanical structure, high voltage isolation, matching coefficient of thermal expansion (CTE), and low moisture absorption.

[0077] V-terminal assembly 18 includes an elongated first bar 18B situated between two terminal legs 18L. In the illustrated embodiment, the elongated first bar 18B forms a U-shape together with the two terminal legs 18L. Other shapes, such as T-shaped, V-shaped, and C-shaped, are conceivable. Each terminal leg 18L is shaped such that it extends outward from the first bar 18B toward the A side of the power module 10, passes through the side of the housing 12, folds upward toward the top of the housing 12, and then folds inward above the top portion of the housing 12 to provide a V-terminal contact 18C. Thus, the distal portion of each terminal leg 18L bends back above its middle portion. As described above, the bottom portion of the first bar 18B of V-terminal assembly 18 is directly attached to the source contact of 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.

[0078] Similarly, the MID-terminal assembly 20 includes an elongated second rod 20B situated between two terminal legs 20L. In the illustrated embodiment, the second rod 20B, together with the two terminal legs 20L, forms a U-shape. Other shapes are contemplated, such as T-shapes, V-shapes, and C-shapes. Each terminal leg 20L is shaped such that it extends outward from the end of the second rod 20B toward the B side of the power module, through the side of the housing 12, folds upward toward the top of the housing 12, and then folds inward above the top portion of the housing 12 to provide a MID-terminal contact 20C. Thus, the distal portion of each terminal leg 20L bends back above its middle portion. The bottom portion of the second rod 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.

[0079] In this embodiment, the MID terminal assembly 20 further includes a plurality of (3) integrally formed jumpers 20J extending from the second rod 20B toward the first rod 18B of the first terminal assembly 18. As described above, the distal end of the jumper 20J is directly attached to the first trace 34 located on the top surface of the substrate 14. The jumper 20J may be replaced by a single rod. Furthermore, the number of jumpers 20J may vary in different embodiments. In a particular embodiment, each power device 16 has one jumper 20J coupled to the MID terminal assembly 20.

[0080] Two opposing V+ terminal assemblies 22 are each shaped similarly to the terminal legs 18L, 20L of the first terminal assembly 18 and the second terminal assembly 20. Other shapes are contemplated. One end of each opposing terminal 22 is directly attached to a second trace 36 located on the top of the substrate 14. Each opposing terminal 22 extends outward from the substrate 14 toward the C and D sides of the power module 10, through the corresponding side of the housing 12, folds upward toward the top of the housing 12, and then folds inward toward the top portion of the housing 12. Thus, the distal portions of each V+ terminal assembly 22 bend back above its middle portion. The exposed distal ends of the opposing terminals 22 provide terminal contacts 22C for the V+ terminal assembly 22. As shown, the V- terminal assembly 18 and the MID- terminal assembly 20 are located on the opposing A and B sides of the power module 10. The two opposing V+ terminal assemblies 22 are located on the remaining opposing C and D sides of the power module 10. It should be noted that, depending on the application, the V-terminal contact 18C, the V+ terminal contact 22C, and the MID-terminal contact 20C can be coplanar or non-planar. A non-planar configuration placing the contacts on two, three, or more different planes can provide additional options for connecting these contacts to external busbars.

[0081] A set of nested signal pin assemblies 24, 26 and 28, 30 are arranged between the terminal legs 18L of the V-terminal assembly 18 and the terminal legs 20L of the MID-terminal assembly 20. In the illustrated embodiment, the pin assemblies 24, 26, 28, 30 are U-shaped and include pins 24B, 26B, 28B, 30B and a pair of pin legs 24L, 26L, 28L, 30L extending from each pin 24B, 26B, 28B, 30B. The pin legs 24L, 26L, 28L, 30L extend outward through the respective sides of the housing 12 and are folded vertically upward. A connection line 32 electrically connects the power device 16 to the pins 24B, 26B, 28B, 30B of the pin assemblies 24, 26, 28, 30.

[0082] In summary, there are two types of electrical circuits in the power module: power circuits and signal circuits. The power circuit is a high-voltage, high-current path through transistors Q1 and Q2, used to deliver power to the load via the drain (or collector) and source (or emitter) of transistors Q1 and Q2, where the load is typically connected to the MID-terminal assembly 20. The signal circuit is a low-voltage, low-current path through the gates G1 and G2 (or base) and the source S (or emitter) of transistors Q1 and Q2. The gate-source (or base-emitter) signal path actuates transistors Q1 and Q2 to effectively turn them on or off. As detailed below, the signal circuit may also involve the source-Kelvin connections K1 and K2 of transistors Q1 and Q2.

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

[0084] Opposite V+ terminal assemblies 22 are directly attached to opposite ends of the second trace 36 located 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. Therefore, power flows through the terminal assemblies 22 into the opposite ends of the second trace 36 located on the substrate 14 and to the drain contact of transistor Q1. The drain contact of transistor Q1 is located on the bottom of transistor Q1 and is also directly attached to the second trace 36. Transistor Q1 is attached to the second trace 36 at specific points, that is, the points where the two V+ terminal assemblies 22 are attached to the second trace 36 and where transistor Q1 is equidistant from each other are the attachment points of the two V+ terminal assemblies 22.

[0085] Then, power flows upward from the drain of transistor Q1 through transistor Q1 to the source of transistor Q1. The source of transistor Q1 is attached to the bottom side of the second link 20B of the MID terminal assembly 20. The MID terminal jumper 20J of the MID terminal assembly 20 connects the second link 20B of the MID terminal assembly 20 to the first trace 34 located on the substrate 14. The drain of transistor Q2 is directly attached to the first trace 34 and is equidistant from each other. Power flows upward from the drain of transistor Q2 through transistor Q2 to the source of transistor Q2. The source of transistor Q2 is directly connected to the bottom side of the first link 18B of the V-terminal assembly 18. Therefore, power flows along the first link 18B to the contact 18C of the V-terminal assembly 18 via the opposing legs 18L.

[0086] By using symmetrical V+ terminal assembly 22 and symmetrical V- terminal assembly 18, the current shared between devices is balanced, enabling the use of smaller external contacts. This facilitates leadframe panelization and significantly reduces inductance by shortening the overall current path of the power loop. As further described below, the contacts 18C of V- terminal assembly 18, the contacts 20C of MID- terminal assembly 20, and the contacts 22C of V+ terminal assembly 22 can be electrically connected to external interconnects using laser soldering, solder, ultrasonic soldering, mechanical bonding (clamps, springs, etc.), conductive adhesives, or any other conductive bonding agent.

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

[0088] There are many effective methods for connecting terminals to high-performance buses. Figure 9A and Figure 9B A scheme is depicted using laminated buses: V-bus 48, MID bus 50, and V+ bus 52, respectively connected to V-terminal assembly 18, MID-terminal assembly 20, and V+terminal assembly 22. Thus, the metal plane of the bus extends above the top of the power module 10. For clarity, only the metal components of V-bus 48, MID bus 50, and V+ bus 52 are shown, but the laminate itself is not shown. The illustrated configuration provides a high-density and low-inductance solution, where adjacent power modules 10 can be closely positioned relative to each other, for example, for paralleling or forming a multi-module topology.

[0089] For details, please refer to the following: Figure 9A The V-bus bar 48 has a body 48B, from which two contacts 48C extend. The contacts 48C are physically and electrically connected to contacts 18C of the V-terminal assembly 18. Similarly, the MID bus bar 50 has a body 50B, from which two contacts 50C extend. The contacts 50C are physically and electrically connected to contacts 20C of the MID terminal assembly 20. Figure 9B The V+ bus 52 has a body 52B, from which a single, wider contact 52C extends. The contact 52C is physically and electrically connected to the contact 22C of the opposing V+ terminal assembly 22. Openings in the V+ bus 52 provide access to the contact 48C of the V- bus 48 and to obtain the gate G2 signal and the source-Kelvin K2 signal via pin assemblies 28, 30. Figure 9B The bending in the V+ busbar 48 is shown. In some cases, this bending can be avoided by raising the V+ terminal assembly 22 so that it is not coplanar with the V- terminal assembly 18.

[0090] Figure 9C An alternative configuration for the V+ bus 52 is provided. The V+ bus 52 has an extension 52E extending from the body 52B. The body has two opposing legs 52F that pull downward from the extension 52E to the contact portion 22 of the V+ terminal assembly 22. Figure 9CThe configuration in this configuration slightly sacrifices some inductance (i.e., increases inductance due to the smaller laminated area) in exchange for relative... Figure 9B The configuration offers greater stress relief and lower stiffness.

[0091] exist Figure 10A and Figure 10B Another bus scheme is illustrated herein. In this paper, the bus extends further along the sides of the power module 10 or around its perimeter. This can be useful in situations where there are often more contact areas or where the power module 10 typically requires more access. For example, if soldering or welding tools need to directly touch the metal surfaces of the individual contacts.

[0092] For details, please refer to the following: Figure 10A The V-bus 48' has a body 48B', from which two contacts 48C' extend. The V-bus 48' is biased outside the perimeter of the power module 10, wherein the two contacts 48C' wrap around opposite 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 biased outside the perimeter of the power module 10, wherein the two contacts 50C' wrap around opposite sides of the power module 10 before extending inward and downward to contact the contacts 20C of the MID-terminal assembly 20.

[0093] Turn Figure 10B The V+ bus 52' is offset outside the perimeter of the power module 10 and above the V- bus 48'. The V+ bus 52' has two contacts 52C' that wrap around opposite sides of the power module 10 before extending inward and downward to contact the corresponding contacts 22C of the V+ terminal assembly 22. Many bus schemes and module variations are conceivable depending on the specific system configuration. Ultimately, the goal is to provide a versatile and efficient terminal arrangement to allow for a wide range of end-user solutions.

[0094] For the individual transistors (Q1, Q2), the signal loop or gate-source connection also benefits from low impedance to minimize voltage stress on the gates of transistors Q1 and Q2 during switching. While adding resistors can alleviate or reduce gate stress, this typically comes at the cost of higher package complexity, higher cost, and slower switching speeds. More importantly, for optimal switching performance, the power loop and signal loop should be completely independent of each other to enable lower switching losses through faster, more controllable dynamics.

[0095] The drain-source (or collector-emitter) loop and the gate-source (or gate-emitter) loop share the same connection at the source (or emitter) of the device. If the power path is coupled into the signal path, additional dynamics are introduced through positive or negative feedback. Typically, negative feedback introduces additional losses because the power path coupling is in conflict with the control signal (i.e., the power path coupling attempts to turn the device off when the control signal attempts to turn it on). Positive feedback typically causes instability because the power path coupling amplifies the control signal to the point of device damage. Finally, coupling the power path to the signal path results in degraded switching quality, slower switching speeds, increased losses, and potential damage.

[0096] Accordingly, independent loops improve switching quality. In the illustrated embodiment, the power connection and signal source (referred to as source-Kelvin) have separate paths so that they do not overlap or interfere with each other. The closer the separate connection is to the transistor, the better the switching performance.

[0097] Figure 11 The internal signal loop of the illustrated embodiment is shown. The signal loop of transistor Q1 flows to and through pin assembly 24 G1 and then through bonding line 32 to the gate contact of transistor Q1, where the signal is provided to transistor Q1. The signal loop flows from transistor Q1 through the source contact of transistor Q1. The signal loop flows directly from the source contact to and through pin assembly 26 K1 via another bonding line 32.

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

[0099] Figure 11 The signal loop described is only one example. For example... Figure 12 As shown, other embodiments may include additional signal traces 54 located on top of the substrate 14. In this embodiment, a set of bonding lines 32 first connects the gate and source contacts of the transistors to the additional signal traces 54, and a second set of bonding lines 32 connects these additional signal traces 54 to appropriate pin assemblies 24-30 (G1, G2, K1, K2). While the latter configuration does allow for a simpler signal pin implementation, it requires a significantly larger substrate area, which may increase costs. Finally, the layout is flexible to be compatible with both, and the various embodiments can be enhanced or optimized for different applications or specifications.

[0100] Transconductance mismatch between parallel devices creates further problems. Transconductance is essentially the current gain of a device and corresponds to the relationship between output current and input voltage. During switching, the input voltage rises, causing the output current to rise accordingly. If there is a transconductance difference between parallel devices (i.e., shared in silicon carbide power devices), each device has slightly different turn-on characteristics. Because the current flowing through the devices differs, slightly different voltages are supplied to each device. These voltage mismatches cause a 'balancing current' to flow between the devices during switching.

[0101] This balancing current prefers the path of lowest impedance, which can pass through the signal loop rather than the power loop. Similar to the problem of interference with coupled power and signal loops, this balancing current can affect switching quality. Since signal loops are not designed to carry high currents, introducing this high, uncontrolled current through the signal loop can also cause reliability issues.

[0102] In one embodiment, a slightly lower inductance is found through a metal strip extending across the source pads located on the top side of the device. Figure 13 These paths are described in the text. In contrast, the source junction path has a relatively higher impedance in terms of effective path length and cross-section. In practice, the balancing current flows through the power contact and does not interfere with the signal.

[0103] Now turning Figures 14A to 14D The package is encapsulated in a protective plastic or epoxy resin housing 12 by transfer molding, compression molding, injection molding, or similar processes. Figures 14A to 14D The high-brightness highlights are emphasized, and several significant features of the housing 12 are discussed below. For example... Figure 14B As shown, the back metal of the power substrate 14 is exposed on the bottom side of the power module 10 to provide thermal pads 56. The thermal pads 56 serve as thermal contact surfaces to remove heat from the power module 10. The thermal pads 56 may be sintered, soldered, epoxidized, or attached in a similar manner to a heat sink or cold plate (not shown) to further aid in the removal of waste heat from the power module 10.

[0104] The features within the housing can be altered based on the manufacturing method. Figures 14A to 14DThe embodiments shown represent structural features of transfer molding. Four clamping pin marks 57 are present; however, depending on the overall dimensions of the power module 10, more or fewer clamping pin marks may be present. The clamping pins (not shown) press directly against the power substrate during the transfer molding process to limit the amount of plastic seepage or smearing across the exposed portions of the thermal pads 56. This ensures that the hot surface is free of debris and can be used for efficient heat removal. Ejection marks 58 are also present around the perimeter of the housing 12. Ejection marks 58 are small notches created by ejector pins (not shown) used to remove the power module 10 from the mold (not shown) while it is still hot. The specific locations and associated geometries of these features vary depending on the specific product size and implementation.

[0105] Gap and creepage can be a significant aspect of high-voltage products. A gap is the shortest direct path in the air between conductors at different voltage potentials. Creepage is the shortest direct path along the surfaces between conductors. Meeting safety standards is challenging and often inconsistent with manufacturing methods (tooling, epoxy flow, etc.) and product dimensions (occupancy area and power density). A proper balance is particularly difficult to achieve for smaller transfer-molded packages, especially lower profile and higher voltage SiC-based products.

[0106] In certain embodiments, the gap distance is sufficient and within standard limits. To increase the creepage distance and correspondingly increase the maximum permissible voltage, a creepage extender 60 is used. The creepage extender 60 is a groove, ripple, or other surface reinforcement that extends the surface distance between conductors at different potentials. As shown, the creepage extender 60 is included as part of a plastic or epoxy housing 14, thereby providing additional functionality without increasing cost. Figure 14C and Figure 14D One implementation of these features on the housing 12 of the power module 10 is shown. Depending on the specific design implementation, other patterns are possible on the top and back sides.

[0107] like Figure 15 As shown, compared to signal contacts such as pin assemblies 24, 26, 28, 30, some or all of the edge power contacts, such as V-terminal assembly 18 and MID-terminal assembly 20, can be embedded from the edge of housing 12 to minimize the length of the power circuit. The signal contacts provided by pin assemblies 24, 26, 28, 30 require more space to better accommodate the bonding wires 32 from the device; therefore, their housing portions extend beyond the edges of the entire housing 12. This profile feature allows for inductance optimization for each individual power circuit and signal circuit.

[0108] Pin assemblies 24, 26, 28, and 30 extend along the horizontal strip to accommodate parallel devices. Externally, there are various methods for forming the pins' contacts, which can be attached to printed circuit board gate drivers, wiring, or similar components. Figures 16A to 16D Some variations are described below. For the sake of brevity and clarity, only pin components 28 and 30 are discussed; however, the same concept applies to pin components 24 and 26.

[0109] As mentioned above, in Figure 16A The first embodiment is shown, in which the pin assemblies 28 and 30 are U-shaped and coaxial. In these embodiments, the pin legs extend beyond the respective sides of the housing and then fold upward toward the top of the housing at an angle between 87 and 93 degrees.

[0110] The first design takes advantage of the product's symmetry. Accordingly, pin assemblies 28 and 30 extend out of housing 12, and the hole 30H in the pin 30B of the external pin assembly 30 provides stress relief. Figure 16B The second solution provided does not include a hole for stress relief. Instead, stress relief in the pin 30B is inherent due to its U-shape and the fact that a portion of the housing 12 is present in the U-shaped bend of the pin assemblies 28 and 30. Figure 16C and Figure 16D As shown, in other embodiments, three pins can be used. In these embodiments, the outer pin assembly 28 remains U-shaped with two legs 28L. However, the central inner pin assembly 30 has only a single leg 30L. The rod 30B for the pin assembly 30 can take almost any shape, such as... Figure 16C In the angle or triangle shape or Figure 16D The T-shape in the middle.

[0111] Depending on the specific requirements of the end system and the format of its gate driver, there are many possible variations of the pin assembly. The illustrated embodiment was developed with consideration for modularity and flexibility, enabling a variety of potential product variations.

[0112] like Figure 17A and Figure 17B Other pin variations shown include modifications to some legs of pin assemblies 24, 26, 28, and 30. For example, removing one leg from pin assemblies 24, 26, 28, and 30 allows the gate and / or source Kelvin drivers on the PCB to use only two contacts (compared to four contacts in the previous embodiment). Asymmetric schemes can be used to maximize the amount of metal area used by the external bus. Figure 17AIn the middle, the internal pin assemblies 26 and 30 each have legs 26L and 30L respectively. One leg of the external pin assemblies 24 and 28 is trimmed so that each pin assembly 24 and 28 retains only one leg 24L and 28L. Figure 17B In the middle, one leg of the internal pin assembly 26, 30 and the external pin assembly 24, 28 is modified so that each pin assembly 24, 26, 28, 30 retains only one leg 24L, 26L, 28L, 30L.

[0113] As described above, the terminal and pin assemblies 18-30 are formed from and combine functions from the leadframe 44 to provide high-current internal interconnects, bonding wire locations, and external terminal contact surfaces. A portion or a portion of the leadframe 44 attaches both to the top-side source pads of transistors Q1 and Q2 and to the substrate 14. The leadframe 44 can be attached to the various components in several ways, including soldering, sintering, conductive epoxy, laser soldering, ultrasonic soldering, etc. Figure 18 As shown, surface-reinforcing features such as holes, slits, and beveled edges are called 'solder or epoxy catch' and can be used to enhance the strength of the joint.

[0114] The strip on leadframe 44 that is directly attached to the top-side source pad can have a few different features. Depending on the specific layout of the packaged device, it can have various solder joint implementations. It can also include corrugations between devices (no image) for thermal expansion stress relief and enhanced die flow. Various bends in leadframe 44 can be used as further means of stress relief.

[0115] Externally, terminal and pin assemblies 18-30 are attached to busbars, wiring, printed circuit boards, etc. The system of terminal and pin assemblies 18-30 can be deformed. It is desirable to avoid applying these external forces to the power devices or connection lines. Therefore, if necessary, holes and / or other reserved features are placed in the lead frame 44 so that when pulled, the molding compound filling these holes bears the stress, rather than sensitive internal components.

[0116] The holes 62 and / or other retained features in the lead frame 44 are positioned to align with the positions of the clamping pins used in the transfer molding process. Ideally, these pins press directly onto the substrate. The holes 62 provide clearance to allow the pins to achieve this. They also serve as stress relief after the assembly is molded.

[0117] To save costs, the lead frame 44 is manufactured from a metal sheet during the etching or stamping process. Figure 19A and Figure 19BAn example is presented here. The contact area and internal features are engaged to the outer frame via narrow tabs. To streamline processing in the panel or housing (magazine), many metal sheets begin flat. Only internal bending is formed. Due to the multiple heating processes required for the component during manufacturing, thermal expansion slits are added to break down larger copper areas. This limits expansion and warping of the component.

[0118] After attaching the lead frame 44 to the power device and substrate, bonding wires, and then molding, trimming is performed from the outer frame at the location of the bonding tabs. Typically, the bending of the outer contact portion is folded and shaped using procedural steps and selective trimming.

[0119] For automated, high-volume production, these lead frames 44 are typically patterned into arrays. These arrays are processed across multiple machines, usually loaded from receiving boxes or racks. Holes located on the top and bottom edges are used for fixing, positioning, keying, and processing. Figure 20 An exemplary lead frame array 64 with four lead frames 44 is shown. The specific features of the lead frames 44 and the lead frame array 64 vary depending on the product configuration, product size variation, and manufacturing equipment type.

[0120] The potential benefit of the illustrated embodiment is the ability to scale up or down the main layout to optimally meet the power handling and budget requirements of a large number of systems and applications. The power module 10 can accommodate different combinations of device widths and lengths at different counts by parametrically extending the relevant dimensions. It should be noted that scaling the power module 10 in this manner does not diminish or limit the core benefits of the basic packaging scheme. Figure 5 and Figure 21 Examples of scalability are presented, in which, Figure 5 A power module 10 with three transistors Q1 (16) and three transistors Q2 (16) is shown, and Figure 21 A laterally extended power module 10 with six transistors Q1 (16) and six transistors Q2 (16) is shown.

[0121] In certain embodiments, a common set of materials is needed to minimize the number of unique manufacturing tools required to manufacture the components. Therefore, an alternative form of scalability is to maintain the same substrate and leadframe layout and adjust the number or size of devices within the defined footprint. For example, in some cases (higher current), the device can be widened, and in others (lower cost), the device can be narrowed. The footprint can also be reduced to decrease the maximum power handling capacity relative to a fully filled power module 10. Figure 22A and Figure 22B Examples are provided in the document. Figure 22A and Figure 22B The power module 10 in the middle is relative to Figure 5 The power module provided is stretched laterally so that transistor Q1(16) has five positions and transistor Q2(16) has five positions. Figure 22A The power module 10 is completely filled with five transistors Q1 (16) and five transistors Q2 (16). Figure 22B The power module 10 is filled with three transistors Q1 (16) and three transistors Q2 (16). Therefore, assuming the same type of components are used in both scenarios, Figure 22B Two positions (non-filled position 70) are intentionally kept non-filled and are consistent with... Figure 22A This is equivalent to a 40% reduction in power handling capacity.

[0122] The scalability feature allows for in-package optimization. It also helps to provide designs that can be enhanced or optimized from the outside. The half-bridge legs of power module 10 can be arranged to form a variety of topology variations. In most cases, the respective V- terminal assembly 18 and V+ terminal assembly 20 can be connected to the same low-inductance bus. The MID terminal assembly 22 or AC output can: (1) be connected to the package in parallel for higher current; (2) keep the individual bridge legs independent; or (3) have some combination of both.

[0123] Figure 23 An example of a parallel configuration with a laminated bus is shown, in which the V-terminal assembly, V+ terminal assembly, and MID-terminal assembly of three power modules 10A, 10B, and 10C are connected in parallel to a slim V-bus (not shown), a slim V+ bus 72, and a slim MID-bus 74, respectively. The number of power modules 10X connected in parallel can be increased or decreased to suitably or optimally match the power requirements of the system. This feature allows for the cost-effective use of the same core product in multiple systems across all power levels.

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

[0125] Figure 25A three-phase topology with three bridge legs and a laminated bus is shown. Three power modules 10A, 10B, and 10C are provided. The V-terminal assembly (not shown) and V+ terminal assembly 22 of power modules 10A, 10B, and 10C are connected in parallel to an elongated V-bus (not shown) and an elongated V+ bus 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.

[0126] Can be Figure 23 and Figure 24 The ideas provided are combined. Figure 26 This demonstrates an arrangement using a laminated bus to provide three bridge legs, with each bridge leg having two power modules 10 connected in parallel. Specifically, for the first leg, power modules 10A and 10B are connected in parallel using MID-bus 74A; for the second leg, power modules 10C and 10D are connected in parallel using MID-bus 74B; and for the third leg, power modules 10E and 10F are connected in parallel using MID-bus 74C.

[0127] Silicon carbide (SiC) power devices offer advanced performance benefits, including high-voltage shielding, low on-resistance, high current, fast switching, low switching losses, high junction temperature, and high thermal conductivity. Ultimately, these characteristics lead to a significant increase in potential power density, which is the power handled per area or volume.

[0128] However, realizing this potential requires addressing significant packaging and system-level challenges. Higher voltages, currents, and switching speeds mean significantly higher physical stresses are applied to smaller and more constrained regions. To fully leverage the advantages offered by SiC technology, one or more of the following challenges have been addressed:

[0129] • Provide a common circuit topology both inside the package (internal layout) and outside the package (interconnection);

[0130] • Remove waste heat from electrical conduction and switching losses from equipment;

[0131] • Provides effective electrical isolation between high voltage potentials;

[0132] • Provides low-power loop inductance for minimal high-voltage overshoot during high-speed switching;

[0133] • Achieve minimal gate voltage overshoot and low signal loop inductance for oscillation;

[0134] • Optimize the internal layout to allow power devices to be connected in parallel, enabling current sharing in both dynamic and steady states;

[0135] • Provides low power loop resistance for carrying high current without overheating;

[0136] • Provides an external terminal arrangement ideally suited for parallelizing modules and directly characterizing their arrangement into circuit topologies; and

[0137] • Provides a balanced arrangement of power devices.

[0138] The internal layout or physical arrangement of the package components has a significant impact on each of these factors. As the number of devices within the package increases, achieving optimal layout becomes increasingly difficult. Parallelization is a common technique used for SiC devices to improve the package's current capability. With multiple devices connected in parallel, balancing tradeoffs between heat dissipation, power loop inductance, signal loop inductance, and package size becomes increasingly challenging. Forming a half-bridge topology introduces additional layout challenges as critical parameters such as power loop inductance between switching positions and equivalent heat transfer become even greater design challenges.

[0139] In addition to performance, costs should be kept low to attract a wider range of markets and applications. Several technologies can help reduce costs, including:

[0140] • Limit the use of individual components by providing multiple functions beyond the same component;

[0141] • Optimize functionality and performance beyond individual components through design;

[0142] • Limit the need for secondary or complete operations;

[0143] • Use known conventional or well-established manufacturing methods to achieve high yields;

[0144] • If possible, use batch or continuous processing, employing panels, strips, arrays, magazines, etc.; and

[0145] • Sub-component-based manufacturing methods optimize package size and shape, such as sizing parts manufactured on strips or panels to maximize the use of the raw material.

[0146] Finally, the combination of internal scalability and external modularity results in a highly adaptable core layout that can accommodate a wide range of system requirements.

[0147] This disclosure relates to, but is not limited to, the following:

[0148] • Highly optimized half-bridge package design for next-generation SiC products;

[0149] • Scalable layout, in which products can be made by lengthening or widening the package to allow for a larger SiC area (by larger devices or more devices in parallel);

[0150] • A modular approach to external terminal locations facilitates the paralleling of multiple packages or their arrangement into a common circuit topology;

[0151] • Ultra-low inductance, balanced power circuit layout;

[0152] • Low-inductance, balanced signal loop layout;

[0153] • The actual Kelvin implementation of the signal loop;

[0154] • Left-hand or right-hand signal pin compatibility;

[0155] • Low cost achieved by minimizing the number of unique parts used;

[0156] • Low cost achieved by minimizing the area of ​​the power substrate;

[0157] • Low cost achieved through leadframe array processing;

[0158] • Utilizing the superior manufacturability of the well-designed leadframe array processing and transfer molding;

[0159] • Molded voltage creepage extenders located on the top and bottom sides of the package; and

[0160] • Direct power attachment of the device located on the top side of the lead frame.

[0161] The concepts provided above address one, some, or all of the aforementioned problems to provide a unique and novel power module 10. Those skilled in the art will recognize improvements and variations of this disclosure. All such improvements and variations are considered to be within the scope of the concepts disclosed herein.

Claims

1. A power module, comprising: The substrate has a top surface with a first trace and a second trace; A first plurality of vertical power devices and a second plurality of vertical power devices, wherein 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 includes a first elongated rod, at least two first terminal contacts, and at least two first terminal legs extending between different points on the first elongated rod and the at least two first terminal contacts. as well as The second terminal assembly includes a second elongated rod, at least two second terminal contacts, and at least two second terminal legs extending between different points of the second elongated rod and the at least two 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 rod of the first terminal assembly; and The second plurality of vertical power devices are electrically and mechanically directly coupled between the second trace and the bottom of the second elongated rod of the second terminal assembly.

2. The power module according to claim 1, further comprising: A third terminal assembly and a fourth terminal assembly, the third terminal assembly and the fourth terminal assembly being electrically and mechanically coupled to the first trace on opposite sides of the substrate.

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

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

5. The power module according to claim 4, wherein: Each of the at least two first terminal legs extends beyond the side of the housing and is folded such that the at least two first terminal contacts extend parallel to the top portion of the housing above the top portion of the housing. and Each of the at least two second terminal legs extends beyond the side of the housing and is folded such that the at least two second terminal contacts extend parallel to the top portion of the housing above the top portion of the housing.

6. The power module according to claim 5, further comprising: A third terminal assembly and a fourth terminal assembly, the third terminal assembly and the fourth terminal assembly being electrically and mechanically coupled to the first trace on opposite sides of the substrate, wherein the substrate has four sides, the third terminal assembly being near a first side, the fourth terminal assembly being near a second side opposite to the first side, the first terminal assembly being near a third side located between the first side and the second side, and the second terminal assembly being near a fourth side located between the first side and the second side and opposite to the third side.

7. The power module according to claim 6, wherein: The third terminal assembly includes a third terminal leg and a third terminal contact portion, the third terminal leg extending beyond the side portion of the housing, and the third terminal contact portion extending parallel to the top portion of the housing above the top portion of the housing; and The fourth terminal assembly includes a fourth terminal leg and a fourth terminal contact, the fourth terminal leg extending beyond the side of the housing, and the fourth terminal contact extending parallel to the top portion of the housing above the top portion of the housing.

8. The power module according to claim 5, wherein, The top surface of the housing includes a plurality of grooves that serve as creepage extenders to 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 rod of the first terminal assembly forms a U-shape with the at least two first terminal legs, and the second elongated rod of the second terminal assembly forms a U-shape with the at least two second terminal legs.

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

11. The power module according to claim 10, wherein, The at least one first pin support leg includes two first pin support legs and the at least one second pin support leg includes two second pin support legs, the power module further includes: A third pin assembly includes a third pin and at least one third pin leg extending from the third pin, wherein the third pin is adjacent to the first pin and located between the two first pin legs; and The fourth pin assembly includes a fourth pin and at least one fourth pin leg extending from the fourth pin, wherein the fourth pin is adjacent to the second pin and located between the two second pin legs.

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

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

14. The power module according to claim 11, comprising: The housing encapsulates at least a portion of the first terminal assembly, the second terminal assembly, the first pin assembly, and the second pin assembly, wherein the at least one first pin leg and the at least one second pin leg extend beyond the respective sides of the housing and then fold upward toward the top of the housing at an angle between 87 and 93 degrees.

15. The power module according to claim 11, wherein: 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 contact and source contact of the plurality of vertical power devices; and The second pin assembly is electrically coupled to one of the gate contact and source contact of the second plurality of vertical power devices.

16. The power module according to claim 15, wherein: The third pin assembly is electrically coupled to another contact among the gate contact and the source contact of the first plurality of vertical power devices; and The fourth pin assembly is electrically coupled to another contact of the gate contact and the source contact of the second plurality of vertical power devices.

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

18. The power module according to claim 17, wherein, The at least three first vertical transistors and the at least three 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 include power MOSFETs and the power circuit is a half-H-bridge circuit.

20. The power module according to claim 1, wherein, The first terminal assembly further includes a plurality of jumpers extending from the first elongated rod to the second trace, such that the plurality of jumpers are electrically and mechanically connected to the second trace.

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

22. The power module according to claim 1, wherein: The power circuit includes a power loop and at least one signal loop; and The power circuit 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 circuit is independent of the at least one signal circuit.

24. The power module according to claim 23, wherein, The 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 circuit does not pass through any of the connection lines of the power module.

26. The power module according to claim 1, wherein, The first terminal assembly and the second terminal assembly are symmetrical along at least one 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 comprise silicon carbide.

28. A power module, comprising: The substrate has a top surface with a first trace and a second trace; A first plurality of vertical power devices and a second plurality of vertical power devices are electrically coupled to form part of a power circuit. The first terminal assembly includes a first elongated rod, at least two first terminal contacts, and at least two first terminal legs extending between different points on the first elongated rod and the at least two first terminal contacts. The second terminal assembly includes a second elongated rod, at least two second terminal contacts, and at least two second terminal legs extending between different points of the second elongated rod and the at least two second terminal contacts. A third terminal assembly and a fourth terminal assembly are electrically and mechanically coupled to the first trace on opposite sides of the substrate. as well as A housing encapsulates at least a portion of the first terminal assembly, the second terminal assembly, the third terminal assembly, and the fourth terminal assembly, wherein the substrate has four sides, the third terminal assembly is located on a first side, and the fourth terminal assembly is located near a second side opposite to the first side, the first terminal assembly is located near a third side located between the first side and the second side, and the second terminal assembly is located near a fourth side located between the first side and the second side and opposite to 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 rod of the first terminal assembly; and The second plurality of vertical power devices are electrically and mechanically directly coupled between the second trace and the bottom of the second elongated rod of the second terminal assembly.

29. The power module according to claim 28, wherein: Each of the at least two first terminal legs extends beyond the side of the housing and is folded such that the at least two first terminal contacts extend parallel to the top portion of the housing above the top portion of the housing. and Each of the at least two second terminal legs extends beyond the side of the housing and is folded such that the at least two second terminal contacts extend parallel to the top portion of the housing above the top portion of the housing.

30. The power module according to claim 29, wherein: The third terminal assembly includes a third terminal leg and a third terminal contact portion, the third terminal leg extending beyond the side portion of the housing, and the third terminal contact portion extending parallel to the top portion of the housing above the top portion of the housing; and The fourth terminal assembly includes a fourth terminal leg and a fourth terminal contact, the fourth terminal leg extending beyond the side of the housing, and the fourth terminal contact extending parallel to the top portion of the housing above the top portion of the housing.

31. The power module according to claim 30, further comprising: A first pin assembly includes a first pin rod and at least one first pin leg extending from the first pin rod, wherein the first pin rod is adjacent to the first elongated rod and located between the at least two first pin legs; and The second pin assembly includes a second pin and at least one second pin leg extending from the second pin, wherein the second pin is adjacent to the second elongated rod and located between the at least two second terminal legs.

32. The power module according to claim 31, wherein, The at least one first pin support leg includes two first pin support legs, and the at least one second pin support leg includes two second pin support legs, the power module further comprising: A third pin assembly includes a third pin and at least one third pin leg extending from the third pin, wherein the third pin is adjacent to the first pin and located between the two first pin legs; and The fourth pin assembly includes a fourth pin and at least one fourth pin leg extending from the fourth pin, wherein the fourth pin is adjacent to the second pin and located between the two second pin legs.

33. The power module according to claim 32, wherein: The power circuit includes a power circuit and at least one signal circuit; The power circuit passes through the first plurality of vertical power devices and the second plurality of vertical power devices; The power circuit is independent of the at least one signal circuit; and The 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.

34. The power module according to claim 33, wherein, The power circuit does not pass through any of the connection lines 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 comprise silicon carbide.

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