Power module with overlapping terminals

Abstract

A power module (100) for use in electric vehicle and industrial applications is disclosed. The power module (100) routes high current through a set of metal power tabs (120, 122, 124), rather than delivering high current through a conductive layer of a directly bonded metal structure (102). By orienting the metal power tabs (120, 122) in a micro heart-shaped design, both stray inductance and resistance may be reduced, thereby improving performance while reducing the footprint of the high power module (100). In addition, wire bonds (112) between chip components (110) in a high power semiconductor device module (100) may be replaced by solid metal clips (212) that can better withstand high current and voltage. The SSDC package incorporates metal power tabs (510) and provides heat dissipation via a metal backplane that includes a heat spreader. The heat sink may be immersed in a cooling fluid to provide faster heat dissipation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit and priority of U.S. Patent Application No. 18 / 617,325, filed on March 26, 2024, and entitled “Power Module with Overlapping Terminals,” and U.S. Provisional Patent Application No. 63 / 455,822, filed on March 30, 2023, and entitled “Single Side Direct Cooling (SSDC) Device,” the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates to assembling and packaging semiconductor device modules, semiconductor device assemblies, and semiconductor devices. More particularly, the present invention relates to semiconductor device modules having excellent thermal performance. Background Art

[0004] A semiconductor device assembly (e.g., a chip assembly including a power semiconductor device) can be implemented using multiple semiconductor dies, a substrate (e.g., a die attach pad (DAP)), electrical interconnects, and a molding compound. Power transistors may include, for example, insulated gate bipolar transistors (IGBTs), power metal oxide semiconductor field effect transistors (MOSFETs), and the like. Fast recovery diodes (FRDs) may be used in conjunction with power transistors. Electrical interconnects within a high-power semiconductor device module may include, for example, bonding wires, conductive spacers, and conductive clips. Polymer molding compounds may be used as a sealant to protect components of the device assembly. Such high-power chip assemblies packaged as semiconductor device modules can be used in a variety of applications, including electric vehicles (EVs), hybrid electric vehicles (HEVs), and industrial applications. Summary of the invention

[0005] In some aspects, the technology described herein relates to a device comprising: a directly bonded metal substrate; a first power contact electrically coupled to the directly bonded metal substrate; a second power contact electrically coupled to the directly bonded metal substrate; a distal end of the first power contact, the distal end aligned with a first longitudinal axis; and a distal end of the second power contact, the distal end aligned with a second longitudinal axis that is not parallel to the first longitudinal axis, a proximal end of the first power contact overlapping with a proximal end of the second power contact, wherein the distal end of the first power contact does not overlap with the distal end of the second power contact.

[0006] In some aspects, the technology described herein relates to an apparatus that also includes a heat transfer mechanism coupled to the direct-bonded metal substrate.

[0007] In some aspects, the technology described herein relates to a device that also includes at least two semiconductor dies electrically coupled via wire bonds or a clip.

[0008] In some aspects, the technology described herein relates to an apparatus that also includes an output tab electrically coupled to the direct-bonded metal substrate.

[0009] In some aspects, the technology described herein relates to an apparatus wherein, in operation, current flows from a first power tab to an output tab and from the output tab to a second power tab without flowing through a directly bonded metal substrate.

[0010] In some aspects, the technology described herein relates to an apparatus that also includes a heat dissipation pin oriented perpendicular to a plane of the direct-bonded metal substrate and a plane of the first power tab and the second power tab.

[0011] In some aspects, the technology described herein relates to an apparatus wherein a thickness of the first power tab and the second power tab is approximately three times a thickness of a current path within a conductive layer of a direct-bonded metal substrate.

[0012] In some aspects, the technology described herein relates to a device that also includes a first opening in a distal end of a first power tab and a second opening in a distal end of a second power tab.

[0013] In some aspects, the technology described herein relates to an apparatus wherein perimeters of the first power tab and the second power tab form a heart shape.

[0014] In some aspects, the technology described herein relates to a device comprising: a direct-bonded metal substrate; a metal base plate attached to a bottom layer of the direct-bonded metal substrate; an array of heat dissipation pins attached to the metal base plate; a first metal tab and a second metal tab coupled to the direct-bonded metal substrate, the first metal tab being oriented in a lateral direction relative to the second metal tab; and a plastic housing surrounding a top layer of the direct-bonded metal substrate.

[0015] In some aspects, the technology described herein relates to a device in which a plastic housing is attached to a metal base plate without the use of screws.

[0016] In some aspects, the technology described herein relates to an apparatus that also includes a power tab extending over the direct-bonded metal substrate.

[0017] In some aspects, the technology described herein relates to a device wherein a first metal tab includes a negative terminal and a second metal tab includes a positive terminal, and the device further includes a third metal tab including an output terminal opposite the first metal tab and the second metal tab.

[0018] In some aspects, the technology described herein relates to a device configured to allow current to flow from a positive terminal to an output terminal and back to a negative terminal via a central region of a directly bonded metal substrate.

[0019] In some aspects, the technology described herein relates to an apparatus in which a first metal tab is oriented at a right angle relative to a second metal tab.

[0020] In some aspects, the technology described herein relates to a method comprising: overlapping a proximal end of a first power contact and a proximal end of a second power contact; coupling a clip of the first power contact to a central region of a substrate; coupling a clip of the second power contact to an edge region of the substrate; and coupling a clip of a third power contact to the central region of the substrate.

[0021] In some aspects, the technology described herein relates to a method in which a first power tab, a second power tab, and a third power tab are configured as an integral element of a plastic housing.

[0022] In some aspects, the technology described herein relates to a method wherein coupling a clip of a first power contact and a clip of a third power contact to a central region of a substrate includes stacking the clips over circuitry on the substrate by positioning a plastic housing relative to the substrate.

[0023] In some aspects, the technology described herein relates to a method wherein overlapping includes aligning a first hole in a first power tab with a second hole in a second power tab to produce aligned first and second holes.

[0024] In some aspects, the technology described herein relates to a method that also includes attaching a heat dissipation pin to the substrate, wherein the heat dissipation pin extends through the aligned first and second holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a pictorial perspective view of a power module according to an implementation of the present disclosure.

[0026] Figure 2A and Figure 2B Two different options for circuit layout on a direct bonded metal (DBM) structure are shown according to implementations of the present disclosure.

[0027] Figure 3A and Figure 3B A circuit model of a power module according to a specific implementation of the present disclosure is shown.

[0028] Figure 4 is an enlarged view of a DBM structure according to a specific implementation of the present disclosure.

[0029] Figure 5A is a top perspective view of a single-side direct cooled (SSDC) package according to an implementation of the present disclosure.

[0030] Figure 5B is a bottom perspective view of a single-side direct cooled (SSDC) package according to an implementation of the present disclosure.

[0031] Fig. 6A is an enlarged cross-sectional view of a clip assembly according to an implementation of the present disclosure.

[0032] Figure 6B Reappeared Figure 5B ,

[0033] Figure 7 is a top perspective view of a SSDC package housing three power modules including a wire-bonded version of the circuit layout on a DBM according to an implementation of the present disclosure.

[0034] Figure 8 is a top perspective view of a SSDC package housing three power modules including a clip version of the circuit layout on a DBM according to an implementation of the present disclosure.

[0035] Fig.9A Reappeared Figure 7 .

[0036] Fig. 9B is an enlarged view of a thermistor according to a specific implementation of the present disclosure.

[0037] Fig.10 A computer model of a fluid-cooled SSDC package housing three power modules is shown in accordance with an implementation of the present disclosure.

[0038] Fig.11 is a pictorial perspective view of a fluid-cooled SSDC package housing three power modules according to a specific implementation of the present disclosure.

[0039] Fig.12 is a flow chart of a method for constructing a power module according to a specific implementation of the present disclosure.

[0040] Fig.13 is an exploded view of a SSDC package for a high power electronic device module according to a specific implementation of the present disclosure.

[0041] When with Figure 1 When reading together, the various aspects of the present disclosure are best understood from the following detailed description. It should be noted that, according to the convention in the industry, various features are not necessarily drawn to scale. For the clarity of discussion, the sizes of various features can be increased or reduced arbitrarily. In the accompanying drawings, the same reference symbol can indicate the same and / or similar parts (elements, structures, etc.) in different views. The accompanying drawings generally illustrate various specific implementations discussed in the present disclosure by way of example and not limitation. The reference symbols shown in one accompanying drawing may not be repeated for the same and / or similar elements in the related views. The reference symbols repeated in multiple figures may not be specifically discussed with respect to each figure in these figures, but are provided for the context between the related views. In addition, not all similar elements in the accompanying drawings are specifically referenced with reference symbols when multiple instances of the element are shown. DETAILED DESCRIPTION

[0042] The area occupied by electronic devices is important for material cost and reliability. When electronic devices (e.g., high-power semiconductor device modules) are laid out in an inefficient manner, the wasted space on the substrate unnecessarily increases the material cost. In addition, the wiring between the spaced-apart devices may be inherently more susceptible to damage or breakage, and therefore may cause reliability failures. These considerations are particularly important for high-power modules that include expensive materials such as silicon carbide (SiC), high-tech ceramics made of silicon nitride (Si3N4), and direct bonded metal (DBM) structures (e.g., direct bonded copper (DBC) structures) used as substrates for high-power modules. When these high-power modules are manufactured in large quantities, even a slight reduction in cost per unit can save a lot of cost.

[0043] The present disclosure relates to a specific implementation of a single-sided direct cooling (SSDC) package for a high-power electronic device module. Instead of routing high currents through a DBM structure, the power module routes high currents through a set of metal power tabs. The metal power tabs are about three times thicker than the conductive layer that forms the current path through the DBM structure. By orienting the power tabs in a miniature heart-shaped design, both stray inductance and resistance can be reduced, thereby improving performance while reducing the footprint of the high-power module. In addition, the wire bonds between chip components in the high-power semiconductor device module can be replaced by solid metal clips that can better withstand high currents and voltages. The SSDC package incorporates metal power tabs and provides heat dissipation via a metal baseplate that includes a heat sink. The heat sink can be immersed in a cooling fluid to provide faster heat dissipation.

[0044] Figure 1is a pictorial perspective view of a power module 100 according to some implementations of the present disclosure. The power module 100 provides electrical connectivity for high power semiconductor devices mounted on a DBM 102. The power module 100 may also provide mechanical stability and protection for the high power semiconductor devices, as well as heat dissipation.

[0045] In some implementations, DBM 102 is a multilayer substrate with various electronic components mounted (e.g., attached). DBM 102 includes a die attach pad (DAP) 108 and one or more electronic components, such as a semiconductor die or chip assembly 110 in contact with DAP 108. Chip assembly 110 may include a high-power chip assembly that generates heat and may cause heat accumulation within DBM 102. Chip assemblies 110 are electrically coupled to each other through wire bonds 112. Some of the wire bonds 112 may extend through DAP 108 to form external connections to chip assembly 110. Wire bonds 112 may include copper wires and / or aluminum wires. DAP 108 may be integral with or attached to a first conductive layer of DBM 102. DBM 102 may also include a second conductive layer and a non-conductive layer (not shown).

[0046] In some implementations, DBM 102 may be a direct bond copper (DBC) type structure, a direct electroplated copper (DPC) type structure, or a direct bond aluminum (DBA) type structure. DBM 102 may be referred to as a heat sink that provides single-sided cooling of chip assembly 110. In some implementations, DBM 102 may have a total thickness in the range of about 0.5 mm to about 3.0 mm. In some implementations, DBM 102 is designed as a three-layer DBM structure that includes a non-conductive layer sandwiched between a first conductive layer and a second conductive layer. In some implementations, the non-conductive layer acts as a thermal mass disposed between two outer metal layers to absorb and absorb heat. The non-conductive layer may also provide electrical insulation between the first conductive layer and the second conductive layer of DBM 102.

[0047] In some implementations, the first and second conductive layers of DBM 102 may be or may include metal layers (e.g., copper layers, copper alloy layers) formed on (e.g., bonded to, sputtered to, diffused to, thermally formed on) the non-conductive layer. The first conductive layer may be coupled to a first side of the non-conductive layer, and the second conductive layer may be coupled to a second side of the non-conductive layer. The first conductive layer may be or may include a metal trace as a die attach pad (DAP) 108, on which the chip assembly 110 is mounted (or coupled). Depending on the orientation of the device, the first conductive layer or the second conductive layer may be referred to as an upper conductive layer or a lower conductive layer. In some implementations, the non-conductive layer of DBM 102 may include a ceramic material, such as silicon nitride (Si3N4) or aluminum oxide (Al2O3), Si3N4 being a significantly more expensive ceramic material than Al2O3.

[0048] In some implementations, the die attach pad 108 can be formed from a first conductive layer (eg, a top conductive layer) of the DBM 102. In some implementations, the non-conductive layer and / or the second conductive layer of the DBM 102 can have a larger footprint than the DAP 108.

[0049] The chip assembly 110 can be attached to (e.g., mounted on or coupled to) the top surface of the DAP 108 by a copper sputtering process or by a bonding agent (e.g., epoxy, solder, silver (Ag) sintering material, and / or adhesive). In some implementations including multiple chip assemblies 110, a first chip assembly and a second chip assembly 110 can be coupled to the DAP 108 by two different bonding agents. For example, in some implementations, the first chip assembly 110 can be attached to the DAP 108 by sintering, while the second chip assembly 110 is attached to the DAP 108 by a polyimide tape.

[0050] In some implementations including multiple chip assemblies, the chip assembly 110 may include, for example, a high-power semiconductor device (such as an insulated gate bipolar transistor (IGBT)) and a controller configured to control the IGBT. The controller may also act as a protection device for the IGBT. For example, the controller may provide temperature protection and / or overvoltage protection for the IGBT. The controller may also limit the amount of current delivered to the IGBT. In some implementations, the controller may be configured to monitor the IGBT. In some implementations, other types of semiconductor dies (e.g., MOSFETs, diodes, etc.) may be used as one or more of the chip assemblies 110. In some implementations, a fast recovery diode (FRD) may be used in conjunction with a power transistor.

[0051] The chip assembly 110 may be manufactured on various types of semiconductor substrates, such as semiconductor wafers, such as silicon (Si), silicon carbide (SiC), gallium (Ga), gallium nitride (GaN), aluminum gallium nitride (AlGaN), gallium arsenide (GaAs), aluminum gallium arsenide (AlGaAs), indium phosphide (InP), glass substrates, sapphire substrates, etc. Generally speaking, any type of semiconductor chip may be manufactured on any type of substrate.

[0052] In some implementations, different chip assemblies 110 can be fabricated on different substrates in a hybrid configuration. For example, an IGBT chip assembly 110 can be fabricated on a SiC substrate, while a controller chip assembly 110 can be fabricated on a silicon substrate. In some implementations as described herein, multiple chip assemblies 110 can be fabricated on the same substrate suitable for high power applications, for example, on a SiC substrate.

[0053] In some implementations, the power module 100 may include a first power tab 120, a second power tab 122, a third power tab 124, and heat dissipation pins 125 (five are shown). In some implementations, the power tabs 120, 122, and 124 may be made of a thick metal material of about 1.0 mm thick, capable of supporting a high voltage in a range of about 600 V to about 1700 V and carrying a high current of up to about 900 A. In some implementations, the first power tab 120 and the second power tab 122 are disposed on one end of the DBM 102, and the third power tab 124 is disposed on the other end of the DBM 102. In operation, the first power contact 120 can be coupled to a negative DC terminal (DC-), the second power contact 122 can be coupled to a positive DC terminal (DC+), and the third power contact 124 can be an output terminal, so that current flows from the second power contact 122 to the third power contact 124, and from the third power contact 124 to the first power contact 120. In the power module 100, current is primarily routed through the power contacts 120 and 124 rather than through the DBM 102. In some implementations, the resistance of the power contact can be about 58% less than the resistance in the DBM 102. In some implementations, one or more of the first power contact 120, the second power contact 122, and the third power contact 124 can have rounded ends. During operation of the power module 100, the rounded ends can reduce the concentration of charge. In some implementations, the power contacts 120, 122, and 124 can have square ends, tapered ends, or ends having another shape.

[0054] In some implementations, the proximal end of the first power tab 120 can be aligned with the first longitudinal axis 126, for example, can extend in the same direction as the first longitudinal axis; the proximal end of the second power tab 122 can be aligned with the second longitudinal axis 128; and the proximal end of the third power tab 124 can be aligned with the third longitudinal axis 130. The longitudinal axis represents the direction in which the length (e.g., the longest linear dimension) of the power tab extends. In some implementations, the third longitudinal axis 130 can be aligned with the length of the DBM 102, for example, in the y-direction, such as Figure 1 shown.

[0055] In some implementations, the first longitudinal axis 126 and the second longitudinal axis 128 can be rotated relative to the third longitudinal axis 130, for example, as shown in FIG. Figure 1 The first power contact 120 and the second power contact 122 are provided at an angle of about 45 degrees as shown, or at some other acute angle so that the longitudinal axes are not parallel. In some embodiments, the second longitudinal axis 128 may be oriented at an angle θ relative to the first longitudinal axis 126, wherein the angle θ is symmetrical about the third longitudinal axis 130 so that the third longitudinal axis 130 bisects the angle θ. In some embodiments, the angle θ is approximately 90 degrees so that the proximal ends of the first power contact 120 and the second power contact 122 extend from the DBM 102 in different directions orthogonal to each other. In some embodiments, as seen from a top view, the first power contact 120 overlaps with the second power contact 122 so that the periphery of the first power contact and the second power contact forms a heart shape in the xy plane. In some embodiments, and as shown in this embodiment, the bend 121 of the first power contact 120 is disposed on a portion of the second power contact 122 (when viewed from a top view). In some implementations (and not shown in this view), the bent portion of the second power tab 122 can be disposed on a portion of the first power tab 120 (when viewed from a top view).

[0056] In some implementations, the angle θ is less than 90 degrees or greater than 90 degrees, such that the proximal ends of the first power tab 120 and the second power tab 122 extend outward from the DBM 102 in different directions that are not orthogonal to each other. The angle θ determines the amount of overlap between the proximal ends of the first power tab 120 and the second power tab 122. When the angle θ approaches 0, the overlap area between the first power tab 120 and the second power tab 122 will approach 100%; when the angle θ approaches 180 degrees, the overlap area between the first power tab 120 and the second power tab 122 will approach zero. The overlap area can affect the size, form factor, packaging, and use of the power module 100. The overlap can also affect the current flowing through the power module 100.

[0057] It may be desirable to maximize the overlap area of ​​the first power tab 120 and the second power tab 122 to reduce (e.g., minimize) stray inductance and thermal resistance during high frequency operation of the power module 100. In some implementations, it may be desirable to reduce the stray inductance to less than (e.g.,) about 8 nH and reduce the junction-to-fluid thermal resistance Rthjf to less than about 0.1°C / Watt. Using the power module 100 can reduce the stray inductance by about 40% relative to other designs.

[0058] An opening 132 (e.g., a hole) may be formed in the proximal end of the first power tab 120; an opening 134 may be formed in the proximal end of the second power tab 122; and an opening 136 may be formed in the proximal end of the third power tab 124. The openings 132, 134, and 136 may accommodate fasteners, such as screws, for coupling the respective power tabs 120, 122, and 124 to power, such as high-voltage battery terminals. The openings 132, 134, and 136 may also help accelerate heat dissipation by increasing the surface area of ​​the first power tab 120, the second power tab 122, and the third power tab 124, respectively. For example, the openings 132, 134, and 136 are shown as round holes, but the openings may have any shape.

[0059] In some implementations, the distal end of the first power contact 120 may include a first set of clips 138 (three clips 138a, 138b, and 138c are shown); the distal end of the second power contact 122 may include a second set of clips 140 (three clips 140a, 140b, and 140c are shown); and the distal end of the third power contact 124 may include a third set of clips 142 (two clips, 142a and 142b are shown). The first set of clips 138 extend over the chip assembly 110 and the wire bonds 112 to a central region 144 of the DBM 102, wherein the first set of clips 138 couple the first power contact 120 to the DAP 108. Similarly, the third set of clips 142 may extend over the chip assembly 110 and the wire bonds 112 to a central region 144 of the DBM 102, wherein the third set of clips 142 couples the third power contact 124 to the DAP 108. The second set of clips 140 couples the second power tab 122 to an end region 146 of the DAP 108. Therefore, the second set of clips 140 can have a shorter length than the first set of clips 138 and the third set of clips 142. In some implementations, the width of the outer clips 138a and 138c can be narrower than the width of the inner clip 138b placed in the center of the DBM 102.

[0060] In some implementations, the clips 138 extend parallel to each other in the −y direction, as do the clips 140 disposed below the clips 138 .

[0061] The central region 144 and end regions 146 of the DBM 102 may include solder pads 147 that provide electrical connections to circuits that distribute the electrical power delivered by the clips 138, 140, and 142. In some implementations, the clips 138, 140, and 142 may be connected to the DAP 108, such as the top conductive layer of the DBM 102, by other methods such as ultrasonic welding. The placement of the clips 138 and 142 or the placement of the solder pads 147 may be staggered (e.g., interdigitated) within the central region 144 to efficiently utilize space on the DAP 108. In some implementations, the clip 142 is wider than the clip 138. Therefore, the size of the solder pads 147 may be different to match the footprint of the various clips.

[0062] In some implementations, the heat dissipation pins 125 can extend in a direction perpendicular to the plane of the DBM 102 (e.g., in the z-direction). Each of the heat dissipation pins 125 can be attached to the DAP 108 via the platform 148. The heat dissipation pins 125 can be metallic. In some implementations, one or more of the heat dissipation pins 125 can extend through an opening 150 in the first power tab 120. The opening 150 can also extend through an opening in the overlapping second power tab 122 that is aligned with the opening 150.

[0063] Figure 2A and Figure 2B Two different options for circuit layout on DBM 102 are shown according to some implementations of the present disclosure. Wire bond version 102a is Figure 2A (also Figure 1 ), and the clip version 102b in Figure 2B . The wire bond version 102a includes wire bonds 112 that provide connections between adjacent chip assemblies 110 and between DAP 108 and chip assemblies 110; the clip version 102b includes a clip 212 that provides connections between adjacent chip assemblies 110 and between DAP 108 and chip assemblies 110. The clip 212 can be made of a solid continuous conductive material (e.g., copper, aluminum, or other metal). The clip 212 can support currents and voltages that exceed the current and voltage ratings of the wire bonds 112. In both versions, the wire bond version 102a and / or the clip version 102b can be implemented as a single die having a die size (e.g., die area) of approximately 22 mm2, approximately 25 mm2, approximately 27 mm2, or approximately 32.4 mm2. In some implementations, the wire bond version 102a may be used for certain types of chip assemblies 110, while the clip version 102b may be used for other types of chip assemblies 110. The same type and placement of heat dissipation pins 125 may be used in both the wire bond version 102a and the clip version 102b of the DBM 102.

[0064] Figure 3A and Figure 3B A circuit model 300 of the power module 100 according to some implementations of the present disclosure is shown. Figure 3A The upper half of the DBM 102 is represented as a high-side switch 302 coupling the positive terminal at the second power tab 122 to the output at the third power tab 124 . Figure 3A The lower half of the DBM 102 is also represented as a low side switch 304 coupling the negative terminal at the first power tab 120 to the output at the third power tab 124 . Figure 3B It is shown that the high-side switch 302 may be modeled as a first MOSFET coupled between the positive terminal P and the output terminal. The first MOSFET includes a source terminal S1 , a drain terminal D1 , and a gate terminal G2 . Figure 3B It is also shown that the low side switch 304 can be modeled as a second MOSFET coupled between the negative terminal N and the output terminal. The second MOSFET includes a source terminal S2, a drain terminal D2, and a gate terminal G2.

[0065] Figure 4 is an enlarged view of a DBM 102 according to some implementations of the present disclosure. Figure 4 The enlarged view in FIG. 1 is an enlarged view of the wire bond version 102a, showing details of the DAP 108, the chip assembly 110, the wire bonds 112, and the center area 144. In some specific implementations, the layout of the chip assembly 110 and the wire bonds 112 is symmetrically replicated in the two halves of the DBM 102, with 8 chip assemblies 110 in each half. In some specific implementations, the DBM 102 mounted on the chip assembly 110 is in the form of a direct bonded copper (DBC) structure. The efficient layout of the components within the available surface area of ​​the DBC structure can reduce the cost (e.g., the cost of the copper material) by up to 33%. Efficient layout is promoted by not having to rely on the conductive layer of the DBC to transmit power. The spacing between the chip assemblies 110 can affect the thermal performance of the power module 100. In some implementations, the vertical spacing S1 in the y direction of the rows of the separation chip assemblies 110 may be in the range of about 2.0 mm to about 2.4 mm, and the horizontal spacing S2 in the x direction of the columns of the separation chip assemblies 110 may be in the range of about 2.6 mm to about 3.2 mm. In some implementations, the length L of the DBM 102 is in the range of about 38 mm to about 48 mm, and the width W of the DBM 102 is in the range of about 36 mm to about 44 mm.

[0066] Figure 5A and Figure 5B1 and 2 are top and bottom external views of a single-sided direct cooling (SSDC) package 500 according to some implementations of the present disclosure. In some implementations, three power modules 100 (e.g., a first power module 100a, a second power module 100b, and a third power module 100c) can be assembled into the SSDC package 500. In some implementations, different numbers of power modules 100 can be accommodated in the SSDC package 500.

[0067] refer to Figure 5A In some embodiments, the top side of the SSDC package 500 may include a plastic housing 501, fasteners 502 (8 are shown), and isolation walls 504 (3 are shown). The SSDC package 500 also includes a cover 506 forming a top surface of the plastic housing 501 and alignment pins 507 adjacent to (e.g., disposed on) a frame of the plastic housing 501 outside the periphery of the cover 506. The plastic housing 501 may be made of any polymer material that provides mechanical stability and electrical insulation between the power modules 100. The fasteners 502 (e.g., thumb screws) may be used to clamp the SSDC package 500 around the power modules 100 to secure the power modules 100 in place and to form a tight seal between the cover 506 and the rest of the plastic housing 501. The isolation walls 504 may be used to stabilize and secure the orientation of the first power tab 120 of each power module 100 relative to the second power tab 122 so that a desired angle θ between the longitudinal axes of the power tabs is maintained as shown in FIG. Figure 1 As shown. The isolation wall 504 can also provide electrical insulation between the first power contact 120 and the second power contact 122, which will be coupled to opposite polarities in operation. The use of the isolation wall 504 can reduce the possibility of arc discharge (e.g., electrical discharge) occurring between the first power contact 120 and the second power contact 122. The heat dissipation pins 125 of the DAP 108 attached to the DBM 102 within each power module 100 can extend upward through the holes of the cover 506. These holes can be sealed around the heat dissipation pins 125 to ensure that they are watertight. The heat dissipation pins 125 are an example of a heat transfer mechanism directly coupled to the DBM 102.

[0068] refer to Figure 5BIn some implementations, the bottom side of the SSDC package 500 also includes clips 508 (16 are shown) around the bottom perimeter of the plastic housing 501. The clips 508 couple the SSDC package 500 to a metal base plate 510, which is used as (e.g., acts as) a heat sink for the SSDC package 500. The metal base plate 510 is another example of a heat transfer mechanism coupled (e.g., mechanically coupled) to the DBM 102. The metal base plate 510 may include, for example, aluminum, copper, or alloys thereof (e.g., AlCu). The metal base plate 510 may include tabs 512 (8 are shown) having openings 514 to accommodate fasteners for mounting the SSDC package 500. In some implementations, the metal base plate 510 may include heat sinks (fins), such as an array of heat dissipation cylinders 516 positioned below each power module 100. Each of the arrays may include, for example, a grid of about 60 heat dissipation cylinders 516 or "pin-shaped heat sinks." The heat dissipation cylinder 516 is another example of a heat transfer mechanism coupled (eg, mechanically and thermally) to the DBM 102 .

[0069] Fig. 6A An enlarged cross-sectional view of a clip assembly according to some implementations of the present disclosure is shown. Figure 6B Reappeared Figure 5B . The clip assembly includes a clip 508 and an edge 518 formed in a recess 520 of the metal base plate 510. The clip 508 can be shaped to interlock with the edge 518 of the metal base plate 510. Once the clip 508 has grasped the edge 518, the clip 508 can be pushed downward in the -z direction to firmly hold the metal base plate 510 on the underside of the plastic housing 501, thereby ensuring that the power module 100 is safely held in the watertight enclosure. Mechanically locking the plastic housing 501 to the metal base plate 510 using the clip 508 can replace the use of screws to attach the plastic housing 501 to the metal base plate 510, thereby simplifying assembly. In some specific implementations, an adhesive (e.g., epoxy or other types of waterproof glue) can also be used to secure the plastic housing 501 to the metal base plate 510 before locking the clip 508 in place.

[0070] Figure 7 is a pictorial perspective view of the top side of the SSDC package 500 according to some specific implementations of the present disclosure. Figure 7 In the illustrated view, the cover 506 is removed to expose the first power module 100a, the second power module 100b, and the third power module 100c. Figure 7 Each of the illustrated power modules 100 is implemented with a wire-bonded version 102 a of the DBM 102 . Figure 7The interior of the SSDC package 500 (eg, of the plastic housing 501) is shown to further include a separation region 700. The separation region 700 of the plastic housing 501 provides spacing, such as physical and electrical isolation, between the power modules 100 within the SSDC package 500.

[0071] Figure 8 is a pictorial perspective view of the top side of the SSDC package 500 according to some specific implementations of the present disclosure. Figure 8 In the illustrated view, the cover 506 is removed to expose the first power module 100a, the second power module 100b, and the third power module 100c. Figure 8 Each of the power modules 100 shown is implemented using a clip version 102b of the DBM 102. Figure 7 , Figure 8 The interior of the SSDC package 500 is shown to further include a separation region 700. The separation region 700 of the SSDC package 500 provides spacing, such as physical and electrical isolation, between the power modules 100 within the SSDC package 500.

[0072] Fig.9A Reappeared Figure 7 , shows a SSDC package 500 implemented using a wire-bonded version 102a of the DBM 102. Fig. 9B An enlarged view of a device (e.g., a thermistor 900) according to some specific implementations of the present disclosure is shown. The thermistor 900 can be disposed in the partition region 700 of the SSDC package 500 implemented with the wire bond version 102a or the clip version 102b of the DBM 102. The thermistor 900 can be attached to a separate DAP 108 along with the heat dissipation pins 125 on either end of the thermistor 900. The thermistor 900 can be used to monitor the temperature of the power module 100 within the SSDC package 500.

[0073] Fig.10A model of a cooling unit 1000 according to some implementations of the present disclosure is shown. The cooling unit 1000 is a structure, such as a water jacket, that can be used to surround the lower portion of the SSDC package 500 to help dissipate heat from the metal base plate 510. When the cooling unit 1000 is used with the metal base plate 510, the heat dissipation cylinder 516 can be equipped with an O-ring (not shown) to prevent the cooling fluid from leaking into the SSDC package 500. The cooling unit 1000 is another example of a heat transfer mechanism coupled (e.g., mechanically and / or thermally coupled) to the DBM 102. In some implementations, the cooling unit 1000 may include a coolant inlet 1002 located at the right end of the cooling unit 1000 and a coolant outlet 1004 located at the left end of the cooling unit 1000. The coolant inlet 1002 can allow a flow of cooling fluid (not shown) to enter the cooling unit 1000. The coolant outlet 1004 can provide an outlet for the cooling fluid to leave the cooling unit 1000. The cooling fluid can be, for example, water, ethylene glycol (e.g., ethylene glycol-50), or another fluid having properties suitable for absorbing heat from the metal base plate 510. In some implementations, the cooling fluid can flow through the cooling unit 1000 at a flow rate of about 7 liters / minute to about 10 liters / minute. In some implementations, the cooling fluid can be supplied to the cooling unit 1000 at a temperature of about 45°C.

[0074] The cooling unit 1000 can be used to simulate potential cooling scenarios for a power module 100 housed in a SSDC package 500. The numerical model used for the simulation can be a three-dimensional (3D) model that uses steady-state thermal analysis to test different flow and heat transfer variables and calculate the junction-fluid thermal resistance (Rthjf). Both the maximum Rthjf per switch and the average Rthjf per switch can be determined. The maximum Rthjf per switch can be calculated as (Tj-Tf) / power dissipation per switch, where Tj is the maximum junction temperature and Tf is the fluid temperature of the cooling fluid. The average Rthjf per switch can be calculated as (Tj-Tf) / power dissipation per switch, where Tj is the average junction temperature and Tf is the fluid temperature of the cooling fluid. The 3D model can be run for both the wire bond version 102a and the clip version 102b of the DBM 102.

[0075] Fig.11 A pictorial view of a fluid-cooled SSDC package 1100 according to some embodiments of the present disclosure is shown. The fluid-cooled SSDC package 1100 includes a cooling unit 1101, which can be configured to Fig.10The model shown is constructed to form a water jacket around the SSDC package 500, thereby exposing the lower portion of the SSDC package 500 to the cooling fluid to remove heat from the metal base plate 510. A coolant inlet 1102 corresponding to the coolant inlet 1002 is shown at the right end of the cooling unit 1101. In some specific implementations, the cooling unit 1101 may be constructed of a thermally conductive material (e.g., metal) to provide additional heat dissipation. In some specific implementations, the SSDC package 500 attached to the metal base plate 510 may be set into a cutout in the top surface 1104 of the cooling unit 1101. The cooling unit 1101 may also include a corner cutout 1106 and a hole 1108. The cooling unit 1101 can be installed by inserting a fastener (e.g., a screw) through the hole 1108, rather than directly using the tab 512 to install the SSDC package 500.

[0076] Fig.12 is a flowchart illustrating a method 1200 for manufacturing and packaging a power module 100 according to some specific implementations of the present disclosure. According to some specific implementations described below, referring to the above Figure 1 , Figure 2A , Figure 2B , Figure 3A , Figure 3B , Figure 4 , Figure 5A , Figure 5B , Fig. 6A , Figure 6B , Figure 7 , Figure 8 , Fig.9A , Fig. 9B , Fig.10 and Fig.11 , and reference as follows Fig.13 , operations 1202 to 1210 of method 1200 may be performed to form power module 100 and SSDC package 500. The operations of method 1200 may be performed in a different order, or not performed at all, depending on the specific application. It should be noted that method 1200 may not produce a complete power module 100 or a complete SSDC package 500. Therefore, it should be understood that additional processes may be provided before, during, or after method 1200, and some of these additional processes may be briefly described herein.

[0077] At 1202, the method 1200 includes overlapping the proximal end of the first power contact 120 and the proximal end of the second power contact 122. This step can be performed in conjunction with the plastic housing 501 of the SSDC package 500, as described below. Overlapping the proximal ends of the first power contact 120 and the second power contact 122 can include aligning the first hole in the first power contact 120 with the second hole in the second power contact 122 to form an aligned opening 150. The first power contact 120, the second power contact 122, and the third power contact 124 can all be insert molded into the plastic housing 501. By incorporating the power contacts as an integral part of the plastic housing 501, the desired orientation of the power contacts relative to each other and the DBM 102 can be fixed. In addition, the desired positions of the clips 138, 140, and 142 will automatically align to connect with the pads 147 of the DBM 102, such as landing on the pads.

[0078] At 1204 , the method 1200 includes attaching (eg, coupling) the clip 138 at the distal end of the first power tab 120 to the central region 144 of the DBM 102 so as to overlay the clip 138 over circuitry on the underlying DBM 102 .

[0079] At 1206 , the method 1200 includes attaching (eg, coupling) the clip 140 of the second power tab 122 to the end region 146 of the DBM 102 .

[0080] At 1208 , the method 1200 includes attaching (eg, coupling) the clip 142 at the distal end of the third power tab 124 to the central region 144 of the DBM 102 .

[0081] Operations 1204, 1206, and 1208 may occur automatically when plastic housing 501 is lowered onto metal base plate 510, as described below.

[0082] At 1210, method 1200 includes attaching heat dissipation pins 125 to extend through aligned holes in the overlapping first power tab 120 and second power tab 122. The heat dissipation pins 125 may be attached to DBM 102 and may extend through aligned holes in plastic housing 501, such as Fig.13 as shown in .

[0083] Fig.13 is a exploded view of the SSDC package 500 according to some specific implementations of the present disclosure. Fig.13The assembly of the power module 100 into the SSDC package 500 is shown. The SSDC package 500 can be formed in three layers. In some implementations, the bottom layer 1300 can include a metal base plate 510, a preformed solder layer 1304, and a DBM 102 for each power module 100. The middle layer 1302 can include a plastic housing 501 and power tabs 120, 122, and 124. The cover 506 can serve as an upper layer.

[0084] Starting from the bottom layer 1300, a preformed solder layer 1304 can be deposited onto the metal base plate 510 and patterned to fit the size of the DBM 102. The DBM 102 can then be placed onto the preformed solder layer 1304 and heated (e.g., cured) to melt the preformed solder layer 1304 and the solder pads 147. When the solder is soft, the plastic housing 501 can be lowered onto the metal base plate 510 using the alignment pins 507 as a guide. Note that the plastic housing 501 includes power tabs 120, 122, and 124 as embedded components for each of the three power modules 100. When the plastic housing 501 is lowered onto the metal base plate 510, the power tabs 120, 122, and 124 will make electrical contact with the solder pads 147 in the center region 144 and end regions 146 of the DAP 108. The plastic housing 501 can then be secured to the metal base plate 510 using the clips 508. When cooled, DBM 102 will be secured to base plate 510 , and power tabs 120 , 122 , and 124 will be coupled to electronic devices on DBM 102 , such as chip assembly 110 , via solder pads 147 .

[0085] Finally, the cover 506 can be lowered onto the plastic housing 501 using the alignment pins 507 as guides. Fasteners 502 (e.g., thumb screws) can be used to secure the cover 506. The heat dissipation pins 125 extend through all of the layers including the cover 506, with machined holes formed that align with the locations of the heat dissipation pins 125.

[0086] As described above, various implementations of the power module 100 housed in the SSDC package 500 can improve the performance of the power module 100 while increasing the heat dissipation of the SSDC package 500. A micro-cardioid design that overlaps the positive and negative power tabs and routes high current through the clips of the power tabs can reduce stray inductance and thermal resistance relative to designs that rely on current paths within the conductive layer of the DBM 102. The power tabs can be incorporated into the SSDC package 500 and can be cooled by a heat sink in the base plate 510 of the SSDC package 500. A water jacket can be added to the base plate 510 to provide additional cooling.

[0087] It should be understood that in the foregoing description, when an element such as a layer, a region or a substrate is mentioned on another element, connected to another element, electrically connected to another element, coupled to another element, or electrically coupled to another element, the element may be directly on another element, connected or coupled to another element, or one or more intermediate elements may be present. On the contrary, when an element is mentioned directly on another element or layer, directly connected to another element or layer, or directly coupled to another element or layer, there is no intermediate element or layer. Although the term may not be used in the entire specific embodiment directly on ..., directly connected to ..., or directly connected to ..., the element shown as being directly located on the element, directly connected or directly connected can be mentioned in this manner. The claims of the present application may be revised to narrate the exemplary relationship described in the specification or shown in the drawings.

[0088] As used in this specification, the singular may include the plural unless the context clearly indicates a particular case. Spatially relative terms (e.g., above, above, above, below, below, below, below, at the top, at the bottom, etc.) are intended to cover different orientations of the device in use or operation, except for the orientation shown in the drawings. In some implementations, the relative terms above and below may include vertically above and vertically below, respectively. In some implementations, the term adjacent may include lateral adjacent or horizontal adjacent.

[0089] Some implementations may be implemented using various semiconductor processing and / or packaging technologies. Some implementations may be implemented using various types of semiconductor device processing technologies associated with semiconductor substrates, including but not limited to, for example, silicon (Si), silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), etc.

[0090] Although certain features of the described implementations have been described as described herein, many modifications, alternatives, variations, and equivalents will now occur to those skilled in the art. For example, features shown with respect to one implementation may also be included in other implementations where appropriate. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations that fall within the scope of the implementations. It should be understood that these modifications and variations are presented only by way of example and not limitation, and that various changes in form and detail may be made. In addition to mutually exclusive combinations, any portion of the apparatus and / or method described herein may be combined in any combination. The implementations described herein may include various combinations and / or sub-combinations of the functions, components, and / or features of the different implementations described.

Claims

1. A device (100), comprising: a directly bonded metal substrate (102); a first power contact (120) electrically coupled to the direct-bonded metal substrate; a second power contact (122) electrically coupled to the direct-bonded metal substrate; a distal end of the first power tab (120), the distal end aligned with the first longitudinal axis (126); and A distal end of a second power contact (122), the distal end being aligned with a second longitudinal axis (128) that is not parallel to the first longitudinal axis (126), and a proximal end of the first power contact (120) overlapping with a proximal end of the second power contact (122), wherein the distal end of the first power contact (120) does not overlap with the distal end of the second power contact (122).

2. The apparatus of claim 1, further comprising a heat transfer mechanism (125) coupled to the direct bonded metal substrate (102).

3. The device of claim 1, further comprising at least two semiconductor dies (110) electrically coupled via wire bonds (112) or a clip (212).

4. The apparatus of claim 1, further comprising an output tab (124) electrically coupled to the direct bonded metal substrate (102).

5. The device according to claim 4, wherein: In operation, current flows from the first power tab (120) to the output tab (124) and from the output tab (124) to the second power tab (122) without flowing through the directly bonded metal substrate (102).

6. The device of claim 1, further comprising a heat dissipation pin (125) oriented perpendicular to a plane of the direct-bonded metal substrate (102) and a plane of the first power tab (120) and the second power tab (122).

7. The device according to claim 1, wherein: The thickness of the first power contact (120) and the second power contact (122) is approximately three times the thickness of the current path within the conductive layer of the directly bonded metal substrate (102).

8. The apparatus of claim 1, further comprising a first opening (132) in the distal end of the first power tab (120) and a second opening (134) in the distal end of the second power tab (122).

9. The device according to claim 1, wherein: The peripheries of the first power contact (120) and the second power contact (122) form a heart shape.

10. A device (500), comprising: a directly bonded metal substrate (102); a metal base plate (510) attached to a bottom layer of the direct-bonded metal substrate (102); an array of heat dissipation pins attached to the metal base plate (510); A first metal tab (120) and a second metal tab (122), the first metal tab and the second metal tab being coupled to the directly bonded metal substrate (102), the first metal tab (120) being oriented in a lateral direction relative to the second metal tab (122); as well as A plastic housing (501) surrounds the top layer of the directly bonded metal substrate (102).

11. The device according to claim 10, wherein: The plastic housing (501) is attached to the metal base plate (510) without using screws.

12. The apparatus of claim 10, further comprising a power tab (120, 122, 124) extending over the direct bonded metal substrate (102).

13. The apparatus according to claim 10, wherein: The first metal tab (120) includes a negative terminal, the second metal tab (122) includes a positive terminal, and the device further includes a third metal tab (124) including an output terminal opposite the first metal tab and the second metal tab.

14. The device according to claim 13, wherein: The apparatus is configured to cause current to flow from the positive terminal to the output terminal and back to the negative terminal via a central region (144) of the direct-bonded metal substrate (102).

15. The apparatus according to claim 10, wherein: The first metal link (120) is oriented at a right angle to the second metal link (122).

16. A method (1200), comprising: Overlapping the proximal end of the first power contact (120) and the proximal end of the second power contact (122); coupling the clips (138a, 138b, 138c) of the first power contact (120) to a central region (144) of the substrate (102); coupling the clips (140a, 140b, 140c) of the second power contact (122) to an edge region (146) of the substrate (102); as well as Clips (142a, 142b) of a third power tab (124) are coupled to the central region (144) of the substrate (102).

17. The method according to claim 16, wherein: The first power contact (120), the second power contact (122), and the third power contact (124) are configured as an integral component of the plastic housing (501).

18. The method according to claim 17, wherein: Coupling the clips (142a, 142b) of the first power contact (120) and the clips (142a, 142b) of the third power contact (124) to a central region (144) of the substrate (102) includes stacking the clips (142a, 142b) over a circuit (112) on the substrate (102) by positioning the plastic housing (501) relative to the substrate (102).

19. The method according to claim 16, wherein: The overlapping includes aligning a first hole in the first power tab (120) with a second hole in the second power tab (122) to produce aligned first and second holes (150).

20. The method of claim 19, further comprising attaching heat dissipation pins (125) to the substrate (102), wherein: The heat dissipation pin (125) extends through the aligned first and second holes (150).

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