Power module with injectable conductive component for direct cooling

Abstract

In automotive and industrial applications, an injectable conductive component (114) may be used to couple a high power semiconductor chip assembly (101) to a heat sink (106). The implantable conductive component (114) provides a low resistance interface material and also acts as a binder (105). A cavity (113) defined by the chip assembly (101) and the heat sink (106) may form a container for the injectable conductive component (114) that remains in a liquid phase during operation of the chip assembly (101). The container may be formed as a cavity (113) by removing a portion of the heat sink (106) or by introducing a spacer between the chip assembly (101) and the heat sink (106) using a sealing material. The injectable conductive component (114) may be introduced into the cavity (113) by being injected through a hole (116) formed in the backside of the heat spreader (106).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of U.S. Patent Application No. 18 / 295,217, filed on April 3, 2023, and entitled “Power Module Utilizing Injectable Conductive Component for Direct Cooling,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to assembling and packaging semiconductor device modules, semiconductor device assemblies, and semiconductor devices. More particularly, the present disclosure relates to efficient heat transfer from high power semiconductor device assemblies to heat sinks. Background Art

[0004] Semiconductor device assemblies (e.g., chip assemblies including power semiconductor devices) can be implemented using multiple semiconductor dies, substrates (e.g., directly bonded metal substrates, die attach pads (DAPs)), electrical interconnects, and molding compounds. 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 high-power semiconductor device modules may include, for example, bonding wires, conductive spacers, and conductive clips. Polymer molding compounds may be used as encapsulants to protect components of the device assembly. Such high-power chip assemblies encapsulated as semiconductor device modules can be used in various 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: an electronic power component; a heat sink having a substrate and a plurality of fins; a peripheral wall extending from a surface of the substrate and disposed between the electronic power component and the heat sink; an injectable conductive component disposed in a cavity defined by the electronic power component, the substrate, and the peripheral wall; and an encapsulant disposed around the electronic power component, at least a portion of the heat sink, and the peripheral wall to form a power module.

[0006] In some aspects, the technology described herein relates to a device wherein the perimeter wall is integrally formed within the heat sink.

[0007] In some aspects, the technology described herein relates to a device wherein the perimeter wall is an adhesive film comprising at least one of a silicone, epoxy, or acrylic material.

[0008] In some aspects, the technology described herein relates to a device wherein the peripheral wall is an elastomeric seal.

[0009] In some aspects, the technology described herein relates to an apparatus wherein the heat sink is made of copper.

[0010] In some aspects, the technology described herein relates to an apparatus wherein the electronic power assembly includes an electronic component and a single-sided direct bonded copper (DBC) structure.

[0011] In some aspects, the technology described herein relates to an apparatus in which the electronic power assembly includes an electronic component, a double-sided DBC structure, and a spacer.

[0012] In some aspects, the technology described herein relates to a device in which the injectable conductive component is in a liquid phase at the operating temperature of the electronic power component.

[0013] In some aspects, the technology described herein relates to a device wherein the encapsulant is an epoxy molding compound (EMC).

[0014] In some aspects, the technology described herein relates to an apparatus that also includes a cover plate over the electronic power assembly, wherein the cover plate is secured to the base plate.

[0015] In some aspects, the technology described herein relates to an apparatus that also includes a clip assembly over the electronic power assembly, wherein the clip assembly is secured to the substrate.

[0016] In some aspects, the technology described herein relates to a device comprising: a heat sink having a substrate and a plurality of heat sink structures; a first power submodule coupled to a top surface of the substrate; a second power submodule coupled to the top surface of the substrate; a first peripheral wall located between the first power submodule and a first heat sink structure of the plurality of heat sink structures, the first peripheral wall extending from the top surface of the substrate; a second peripheral wall located between the second power submodule and a second heat sink structure of the plurality of heat sink structures, the second peripheral wall extending from the top surface of the substrate; and an injectable conductive component disposed between the first power submodule and the substrate, the injectable conductive component being surrounded by the first peripheral wall.

[0017] In some aspects, the technology described herein relates to an apparatus that also includes a cover plate coupled to the first power sub-module and the second power sub-module, the cover plate being secured by a plurality of substrate fasteners.

[0018] In some aspects, the technology described herein relates to a device wherein the first perimeter wall and the second perimeter wall are elastomeric seals.

[0019] In some aspects, the technology described herein relates to a device that also includes an encapsulant formed around at least a portion of the cover plate, the first and second power sub-modules, the substrate, and the plurality of heat sink structures.

[0020] In some aspects, the technology described herein relates to a method comprising: forming a cavity, a first hole, and a second hole in a heat sink; coupling an electronic power component to the heat sink using an adhesive; injecting a conductive component into the cavity through the first hole; and sealing the first hole and the second hole.

[0021] In some aspects, the technology described herein relates to a method wherein sealing the first hole and the second hole includes installing a fastener.

[0022] In some aspects, the technology described herein relates to a method wherein sealing the first aperture and the second aperture includes clamping the heat sink to the electronic power component using a clip.

[0023] In some aspects, the technology described herein relates to a method wherein the second hole is a vent hole, and the method further comprises attaching a filter to the vent hole while injecting the conductive component.

[0024] In some aspects, the technology described herein relates to a method that also includes forming an encapsulant around the electronic power component and the heat sink. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figures 1 to 4 are cross-sectional views of injectable conductive compositions disposed in various power modules according to implementations of the present disclosure.

[0026] Figure 5A and Figure 5B is a cross-sectional view of a power module equipped with a clamp according to a specific implementation of the present disclosure.

[0027] Figure 6 is a cross-sectional view of a power module including a plurality of power components and a heat sink according to a specific implementation of the present disclosure.

[0028] Figure 7 is a flow chart illustrating a method of manufacturing a power module having an injectable conductive component disposed therein according to a specific implementation of the present disclosure.

[0029] Figures 8 to 12 The specific implementation according to the present disclosure is illustrated Figure 7 The steps in the method shown in .

[0030] 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 may be increased or reduced arbitrarily. In the accompanying drawings, the same reference symbol may 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

[0031] It is important to dissipate the heat generated in the power semiconductor device to limit the possible adverse effects of overheating, such as dimensional changes, variable operating characteristics and different thermal expansion. Ineffective cooling of semiconductor devices can impose restrictions on the design of power chip components by limiting the allowable power density, circuit density or system speed. When heat is dissipated from a source (e.g., a power module) to a heat sink (sink) (e.g., a heat sink) by conduction, heat transfer depends on the direct contact area between the source and the heat sink. Regardless of the smoothness of the adjacent surfaces of the source and the heat sink and the amount of pressure applied to bring the surfaces together, it is inevitable that there is an irregularity that produces an air gap between adjacent surfaces. The presence of these air gaps at the interface tends to increase the resistance to heat flowing from the source to the heat sink. The thermal resistance of the interface between the two surfaces can be reduced by providing an interface material that fills the air gaps and gaps in the surface.

[0032] Various structures have been used to facilitate heat transfer between two surfaces. Examples used in electronic packaging include adhesives that attach O-rings or heat sinks to chips, greases and gels that are placed between these surfaces, and deformable pads that are sandwiched between these surfaces. In each case, at least one of the objectives is to minimize the interfacial contact thermal resistance while maximizing the thermal conductivity of the transfer medium.

[0033] Current implementations of thermal interface materials (TIMs) for coupling power components to heat sinks may have certain disadvantages. When a TIM is inserted between a source and a heat sink, there is a tradeoff between the thermal conductivity provided by the TIM and the contact resistance of the intervening material. For example, common TIMs (such as thermal greases or gels) advantageously provide low contact resistance due to their low viscosity, but they have limited thermal conductivity, typically less than, for example, 7 W / mK. Other types of TIMs (solid films or sheets of metal foils, graphene, or graphite) have high thermal conductivities, up to, for example, about 30 W / mK. However, such materials tend to have low contact resistance due to their inconsistent surface morphology, which can leave air gaps at the interface surface.

[0034] The present disclosure relates to a specific implementation of a direct cooling method in which a power module can be directly joined to a heat sink using a soldering or sintering process without introducing an intermediate layer. Due to potential weaknesses at the solder / sintering joint, the use of such techniques to join large surface areas brings reliability risks, which are addressed by the structures and methods described herein. Specifically, the reliability of direct joining can be improved by using an injectable conductive component (e.g., a liquid solder material) that remains in a liquid phase under the operating conditions of the power module. The viscosity of the injectable conductive component (e.g., liquid solder) is less than, for example, 0.1 poise, compared to the viscosity of thermal grease greater than 500 poise. This low viscosity allows the injectable conductive component to provide excellent wettability, thereby forming a continuous contact between adjacent surfaces without being reduced by thermal and mechanical stresses. The elemental composition of the injectable conductive component may include gallium, indium, tin, zinc, each of which remains in a liquid phase at low temperatures (e.g., temperatures below, for example, 30°C, and as low as, for example, 7.6°C). Therefore, the temperature range of these liquids covers room temperature and most other operating conditions of power components. Injectable conductive compositions of these metals (eg, liquid solder alloys) provide high thermal conductivity between about 15 W / mK and about 30 W / mK.

[0035] Figure 1 1 is a cross-sectional view showing a high-power semiconductor device module or power module 100 according to some specific implementations of the present disclosure. In some specific implementations, the power module 100 includes a high-power semiconductor chip assembly or electronic power assembly 101. The electronic power assembly 101 includes a single-sided direct bond metal (DBM) structure 102 and at least one electronic component (e.g., a semiconductor die or chip 104 (two are shown)). The chip 104 can be attached to (e.g., mounted on or coupled to) the top surface of the DBM structure 102 by a bonding agent 105 (e.g., solder, silver (Ag) sintered material).

[0036] In some implementations, the chip 104 may include, for example, an iGBT (transistor) semiconductor die as shown on the left and an FRD (diode) semiconductor die as shown on the right. However, other types of semiconductor dies may be used as one or more chips in the chip 104 in the electronic power component 101. In some implementations, the term "chip 104" may refer to a single semiconductor die. The chip 104 may be manufactured on various types of semiconductor substrates (e.g., 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.). In some implementations, the chip 104 may be manufactured on different substrates. For example, the iGBT chip 104 may be manufactured on a silicon substrate of the semiconductor die 104a, while the FRD chip 104 may be manufactured on a silicon carbide substrate.

[0037] In some implementations, the DBM structure 102 may be a direct bonded copper (DBC) type structure, a direct plated copper (DPC) type structure, or a direct bonded aluminum (DBA) type structure. The DBM structure 102 may be referred to as a thermally conductive plate. In some implementations, the DBM structure 102 has a thickness in a range of about 0.5 mm to about 3.0 mm.

[0038] The electronic power component 101 is coupled to a heat sink 106 that provides single-sided direct cooling of the electronic power component 101. In some specific implementations, the heat sink 106 includes a substrate 108 and a plurality of fins 110. The substrate conducts heat away from the electronic power component 101 to be dissipated by the heat sink 110. In the example shown, the heat sink 110 has a rectangular shape, however, the heat sink 110 is not limited thereto. Alternative shapes of the heat sink 110 include cylinders with circular, elliptical, triangular or diamond cross-sections, wavy structures (e.g., serpentine structures), and the like. The heat sink 110 may have a uniform width, or some of the heat sinks 110 may be wider than other heat sinks. The heat sink 110 may be attached to (e.g., adjacent to) the substrate 108, or the heat sink 110 and the substrate 108 may be part of an integral heat sink 106. The heat sink 106 may include one or more highly conductive metals, such as copper (Cu).

[0039] exist Figure 1 In the illustrated implementation, the cavity 113 may be integrally formed in the substrate 108. The perimeter wall surrounding the cavity 113 forms a base 112 that extends outwardly from the surface of the substrate 108 of the heat sink 106. As viewed from the top, the base 112 forms a continuous wall around the perimeter of the cavity 113, while Figure 1In the cross-sectional view shown, the base appears to be two separate structures. Cavity 113 may be defined (e.g., defined) by DBM structure 102 at the top (e.g., on one side) and by base 112 on the side. Alternatively, base 112 may be attached around the periphery of substrate 108 to form the boundary of cavity 113, rather than cavity 113 being formed entirely in substrate 108. In the example shown, cavity 113 has a rectangular shape, however, the shape of cavity 113 is not limited thereto. Alternative shapes of cavity 113 include circular, elliptical, polygonal, and the like. In some embodiments, the height h of the peripheral wall (e.g., base 112) above the top surface of substrate 108 may be in the range of about 30 μm to about 200 μm. Subsequently, by loading the edge of DBM structure 102 onto base 112, electronic power component 101 may be coupled to heat sink 106.

[0040] In some implementations, the cavity 113 is filled (eg, at least partially filled or completely filled) with an injectable conductive composition (eg, liquid solder 114 ). Figures 1 to 6 The cavity 113 is shown after it has been filled. Fig.10 A cavity 113 is shown and described. Liquid solder 114 can be introduced into cavity 113 via a first opening (e.g., injection hole 116) formed near a first end of heat sink 106. When cavity 113 is completely filled with liquid solder 114 or another type of injectable conductive component, optimal heat conduction to heat sink 110 can be achieved. Injection hole 116 extends between a lower surface of heat sink 106 and cavity 113 formed therein. Injection hole 116 is open at both ends. In some implementations, injection hole 116 is formed in one of heat sinks 110 such that injection hole 116 extends through heat sink 110 and through substrate 108.

[0041] A second opening (e.g., vent hole 118) may be formed in the heat sink 106 to allow exhausted air to escape the cavity 113 while the cavity 113 is being filled with liquid solder 114. In some implementations, the vent hole 118 is formed near a second end of the heat sink opposite the first end, so that when liquid solder 114 is injected into the cavity 113 through the injection hole 116, and thereby displaces and compresses the air in the cavity 113. As more liquid solder 114 enters the cavity 113, the air is forced to pass laterally through the cavity 113 toward the second end of the heat sink 106 and exit through the vent hole 118. The vent hole 118 extends between the cavity 113 and the lower surface of the heat sink 106. The vent hole 118 is open at both ends. In some implementations, the vent hole 118 is formed in one of the heat sinks 110, so that the vent hole 118 extends through the entire heat sink 110 and through the substrate 108 to the cavity 113. In some implementations, the vent hole 118 can be equipped with a microfilter to prevent leakage of the liquid solder 114 while allowing trapped air to escape from the cavity 113. In some implementations, a plurality of vent holes 118 can be formed in the heat sink 106.

[0042] According to a specific implementation of the present disclosure, the injectable conductive component (e.g., liquid solder 114) has the properties of low viscosity and high thermal conductivity as described above, which are used to accelerate heat transfer from the electronic power component 101 to the heat sink 106. Therefore, the contained liquid solder 114 remains in a liquid phase under the operating conditions (e.g., operating temperature) of the electronic power component 101.

[0043] At least a portion of the chip 104, the DBM structure 102, and the heat sink 106 may be encapsulated by a molding compound 120 to complete the formation of the power module 100. In some implementations, the molding compound 120 (e.g., a polymer material) may be an epoxy molding compound (EMC) used to seal and protect the electronic power component 101 and various components of the substrate 108. In some implementations, the molding compound 120 may be used for encapsulation before the cavity 113 is filled with liquid solder 114. The encapsulation may be accomplished by, for example, an injection molding process or a transfer molding process.

[0044] Figure 2 is a cross-sectional view showing components of a power module 200 according to some implementations of the present disclosure. The power module 200 includes an electronic power component 201 attached to a heat sink 106 that provides single-sided direct cooling of the electronic power component 201 .

[0045] In some implementations, the electronic power assembly 201 is similar to the electronic power assembly 101, except that the electronic power assembly 201 is equipped with a dual DBM structure 202. In some implementations, the electronic power assembly 201 includes at least one electronic component, such as a chip 104, which is attached to (e.g., mounted on or coupled to) a top surface of the dual DBM structure 202 by a bonding agent 105 (e.g., epoxy, solder, silver (Ag) sintering material, and / or adhesive).

[0046] In some implementations, the dual direct bonded metal (DBM) structure 202 of the electronic power component 201 is designed as a three-layer structure, which includes an upper DBM structure and a lower DBM structure 102 separated by a dielectric 204. In some implementations, the dielectric 204 acts as a thermal mass disposed between two outer metal layers to absorb and absorb heat. The dielectric 204 also provides electrical insulation between the upper DBM structure and the lower DBM structure 102. In some implementations, the dielectric 204 can be made of a ceramic material (e.g., aluminum oxide (Al2O3)).

[0047] Similar to Figure 1 In the illustrated example, the heat sink 106 in the power module 200 has a cavity 113 integrally formed therein, which is bounded on the sides by the base 112. Once the cavity 113 is formed, the cavity can be filled with an injectable conductive component, such as liquid solder 114 as described above, by injection through an injection hole 116 in one of the heat sinks 110. Vent holes 118 formed in another of the heat sinks 110 allow exhausted air to escape the cavity 113 while it is being filled with liquid solder 114. In some implementations, the vent holes 118 can be equipped with a microfilter to prevent leakage of the liquid solder 114 while allowing trapped air to escape from the cavity 113. The contained liquid solder 114 is thus maintained in a si liquid phase under the operating conditions (e.g., operating temperature) of the electronic power assembly 201.

[0048] Figure 3 is a cross-sectional view showing components of a power module 300 according to some implementations of the present disclosure. The power module 300 is similar to the power module 200, except that the power module 300 includes an electronic power component 301 equipped with two dual DBM structures 202 and two heat sinks 106, which provide double-sided cooling for at least one electronic component (e.g., chip 104) of the electronic power component 301.

[0049] In some implementations, the electronic power assembly 301 also includes a spacer 302 inserted between each chip 104 and one of the dual DBM structures 202 to quickly dissipate the heat generated therein. In some implementations, the spacer 302 can be bonded to the chip 104 and to the upper DBM structure 102 by a bonding agent 105. The spacer 302 is designed to absorb the heat generated by the chip 104 and transfer the heat to the adjacent DBM structure 202. The spacer 302 may include a material with high thermal conductivity, such as, for example, copper or its alloy. One such copper alloy that can be used as the spacer 302 is a copper-molybdenum (CuMo) alloy. Whether to use pure copper or, for example, CuMo can be selected based on the heat dissipation requirements of the type of chip 104 coupled to the spacer 302. For example, an FRD chip may operate at a higher voltage or current than an IGBT chip, and therefore may generate more heat and may require more efficient heat dissipation such as provided by a spacer 302 made of pure copper. Cost may also be a factor. Pure copper can be less expensive than copper alloys (eg, CuMo) while providing faster heat dissipation. In some implementations, the thickness of the spacer 302 is in a range from about 0.2 mm to about 3.0 mm.

[0050] like Figure 1 and Figure 2 In the example shown, Figure 3 Each of the heat sinks 106 in the illustrated power module 300 also has a cavity 113 integrally formed therein, which is laterally bounded by the base 112. Once the cavities 113 are formed, each of these cavities can be filled with an injectable conductive component, such as liquid solder 114 as described above, by introduction through an injection hole 116 in one of the heat sinks 110 of the corresponding heat sink 106. Vent holes 118 formed in another of the heat sinks 110 allow exhausted air to escape the cavity 113 as it is being filled with liquid solder 114. In some implementations, the vent holes 118 can be equipped with a microfilter to prevent leakage of the liquid solder 114 while allowing trapped air to escape from the cavity 113. The contained liquid solder 114 is thus maintained in a liquid phase under the operating conditions (e.g., operating temperature) of the electronic power assembly 301.

[0051] Figure 44 is a cross-sectional view showing components of a power module 400 according to some specific implementations of the present disclosure. The power module 400 includes an encapsulated electronic power component 401 attached to the heat sink 106 by a sealing material 412. The encapsulated electronic power component 401 includes a DBM structure 102 and at least one electronic component (e.g., a chip 104). The sealing material 412 can be, for example, an elastic seal (such as an O-ring or a gasket) or an adhesive film including, for example, a silicone, epoxy, or acrylic material, or a combination thereof. If an adhesive is used as the sealing material 412, the thickness of the adhesive can be in the range of about 100 μm to about 200 μm. In addition to the power component being pre-encapsulated, the entire power module 400 (including a portion of the heat sink 106) can also be encapsulated using a molding compound.

[0052] In the power module 400, the heat sink 106 is modified to include a substrate cover 408 above the substrate 108. In some implementations, the substrate cover 408 extends laterally beyond the edge of the substrate 108. Instead of integrally forming the cavity 113 in the substrate cover 408, the power module 400 supports the cavity 113 between the encapsulated electronic power component 401 and the substrate cover 408. That is, the sealing material 412 forms a peripheral wall around the sides of the cavity defined by the substrate cover 408 on the bottom and the encapsulated electronic power component 401 on the top. Once the cavity 113 is formed, the cavity can be filled with an injectable conductive component, such as liquid solder 114 as described above, by injecting through an injection hole 116 in one of the heat sinks 110 of the heat sink 106. The exhaust hole 118 formed in the other heat sink 110 allows the exhausted air to escape the cavity 113 while it is being filled with liquid solder 114. In some implementations, the vent holes 118 can be equipped with microfilters to prevent leakage of the liquid solder 114 while allowing trapped air to escape from the cavity 113. The injection holes 116 and the vent holes 118 extend through the entire heat sink 110, through the substrate 108, and through the substrate cover 408 to the cavity 113. The contained liquid solder 114 is thus maintained in a liquid phase under the operating conditions (e.g., operating temperature) of the encapsulated electronic power component 401.

[0053] Figure 4Further illustrated are electrical connections (e.g., copper connectors) to the encapsulated electronic power component 401, including a lead frame 422, leads 424, a die attach pad (DAP) 425, wire bonds 426, and a clip 428. The chip 104 of the power component 401 can be attached to (e.g., mounted to) the die attach pad 425. In some implementations, the upper DBM structure 102 can be used as the die attach pad 425. The leads 424 provide a signal path from the encapsulated electronic power component 401 to external devices, power, and ground connections. The wire bonds 426 and clip 428 within the encapsulated electronic power component 401 can be used to couple the lead frame 422 to the semiconductor device on the chip 104.

[0054] Figure 4 The power module 400 is shown prior to final packaging, and therefore the molding compound 120 is not present. However, prior to attachment to the heat sink 106, the encapsulated electronic power components 401 are surrounded by an encapsulant 420 (e.g., epoxy molding compound). The molding compound 120 ( Figure 4 424 and a portion of the heat sink 106 before or after the liquid solder 114 is injected.

[0055] Figure 5A and Figure 5B Two specific implementations of a power module 500 according to the present disclosure are illustrated. The power module 500 is similar to the power module 400 in that the liquid solder 114 is disposed between the encapsulated electronic power component 401 on the top, the heat sink 106 on the bottom, and the sealing material 412 forming the peripheral wall on the side. However, the power module 500 also uses a clamp to fix the encapsulated electronic power component 401 to the heat sink 106. Figure 5A In the embodiment, the clamp is in the form of a cover plate 502 that is secured to a base plate cover 408 by base plate fasteners (e.g., screws 504). In some implementations, the screws 504 are driven through the base plate cover 408. Figure 5B In the embodiment of the present invention, the clamp is in the form of a clip assembly 506 that is secured to the substrate cover 408. In some implementations, the clip assembly 506 is wrapped around the substrate cover 408 and thereby applies tension to hold the encapsulated electronic power component 401 against the encapsulation material 412.

[0056] Once the fixture is positioned and secured, the cavity 113 may be filled with liquid solder 114 by injection through the injection hole 116 in one of the heat sinks 110 as described above. A vent hole 118 formed in another of the heat sinks 110 allows exhausted air to escape the cavity 113 as it is being filled with liquid solder 114. In some implementations, the vent hole 118 may be equipped with a microfilter to prevent leakage of the liquid solder 114 while allowing trapped air to escape from the cavity 113. An encapsulant (e.g., a molding compound 120 ( Figure 5A , 5B not shown)).

[0057] Figure 6 6 is a cross-sectional view showing components of a power module 600 according to some specific implementations of the present disclosure. The power module 600 provides a compact arrangement combining multiple power submodules, for example, multiple power modules 500, each power module including an encapsulated electronic power component 401. In some specific implementations of the power module 600, the multiple encapsulated power components 401 are attached to a single heat sink 606 by means of a common cover plate 602 through a sealing material 412. In the power module 600, the heat sink 606 includes a common substrate cover 608 and a plurality of heat sink structures 610, each heat sink structure 610 having a substrate 108 and a heat sink 110. In some specific implementations, substrate fasteners (e.g., screws 504) couple the common cover plate 602 to the top surface of the common substrate cover 608 between each power submodule in the power submodule. The pressure applied by the screws 504 is used to hold each encapsulated electronic power component 401 against the sealing material 412. In each of the plurality of power submodules within the power module 600, an injectable conductive component (e.g., liquid solder 114) is disposed between the encapsulated electronic power components 401, the perimeter wall formed by the sealing material 412 (e.g., an elastomeric seal), and the top surface of the common substrate cover 608. Using the common cover 602 and the common substrate 608 in the power module 600 saves space and provides additional mechanical stability.

[0058] As described above, liquid solder 114 may be introduced into each of the cavities 113 through injection holes 116 extending through the entire heat sink 110 , through the substrate 108 , and through the substrate cover 608 .

[0059] An encapsulant (eg, epoxy molding compound) may be formed around at least a portion of the common cover plate 602 , the plurality of power sub-modules, the common base plate, and the plurality of heat sink structures to complete the power module 600 .

[0060] Figure 7is a flowchart illustrating a method 700 for manufacturing a power module (eg, power module 400) according to some specific implementations of the present disclosure. Figures 8 to 12 In some implementations described, operations 702 to 210 of method 700 may be performed to form power module 400. The operations of method 700 may be performed in a different order or not performed at all, depending on the particular application. It should be noted that method 700 may not produce a complete power module 400. Therefore, it should be understood that additional processes may be provided before, during, or after method 700, and some of these additional processes may be briefly described herein.

[0061] At 702, according to Figure 8 In the illustrated implementation of the present disclosure, the method 700 includes forming the injection holes 116 and the exhaust holes 118 in the respective fins 110 of the heat sink 106 . Figure 8 A top view of the heat sink 106 is shown on the left, and a bottom view of the heat sink 106 rotated 45 degrees is shown on the right. A heat sink 110 arranged in a two-dimensional array (e.g., a matrix) protrudes from the bottom side of the heat sink 106. In some specific implementations, the heat sink 106 can be, for example, a heavy metal plate (e.g., a copper plate), and the heat sink 110 is a bulky metal extension that can efficiently dissipate heat. For example, holes 116 and 118 can be produced in the heat sink 106 by precision drilling. In some specific implementations, the holes 116 and 118 can be drilled into the selected heat sink. Alternatively, the holes 116 and 118 can replace the selected heat sink.

[0062] At 704, according to Fig. 9 In the illustrated implementation of the present disclosure, method 700 includes attaching a sealing material (e.g., adhesive film 900) to the underside of encapsulated electronic power component 401. The bottom surface of encapsulated electronic power component 401 is formed by encapsulant 420. The central region of encapsulated electronic power component 401 includes a die attach pad (DAP) 425 to which chip 104 is mounted. Fig. 9 A lead frame 422 is illustrated having leads 424 extending outwardly away from the DAP.

[0063] At 706, according to Fig.10 In the illustrated implementation of the present disclosure, method 700 includes coupling encapsulated electronic power component 401 to heat sink 106 . Fig.10 A power module 1000 is illustrated in which a cavity 1002 is formed when encapsulated electronic power components 401 and heat sink 106 are joined. Cavity 1002 is bounded by encapsulant 420 on top, substrate 108 of heat sink 106 on bottom, and adhesive film 900 on sides.

[0064] At 708, according to Fig.10 In the illustrated implementation of the present disclosure, method 700 includes curing adhesive film 900 to couple power component 401 to substrate 108 of heat sink 106. The curing operation may include applying heat to the adhesive film, for example, at a temperature ranging from about 20°C to a maximum of about 200°C to prevent internal solder from remelting.

[0065] At 710, according to Fig.11 In the illustrated implementation of the present disclosure, method 700 includes introducing liquid solder 114 into cavity 1002 through injection hole 116 . Fig.11 An injection device 1100 is illustrated in which the heat sink 106 is inverted to expose the heat sink 110, the injection hole 116, and the exhaust hole 118. An injection device (e.g., a syringe 1102) containing liquid solder 114 is inserted into the injection hole 116. The operation of the syringe 1102 pressurizes the liquid solder 114 and forces it through the heat sink 106 into the cavity 113. At the same time, a microfilter 1104 can be attached to the exhaust hole 118. In some specific implementations, the microfilter 1104 can be in the form of a porous cover that can capture particles larger than 0.2 μm in the air exhausted from the cavity 1002 when the cavity 1002 is filled with liquid solder 114.

[0066] At 712, according to Fig.12 In the illustrated implementation of the present disclosure, method 700 includes sealing the hole in heat sink 106 . Fig.12 The heat sink 106 is illustrated after the injection of the liquid solder 114 is completed. Fig.12 , the injection device 1100 has been removed. That is, the syringe 1102 has been removed from the injection hole 116, and the microfilter 1104 has been removed from the exhaust hole 118. Subsequently, both the injection hole 116 and the exhaust hole 118 can be sealed by installing a plug (e.g., a fixing screw 1200) to prevent the liquid solder 114 from leaking out of the cavity 113. Fig.12 It is further illustrated that certain fins 110 through which the injection holes 116 and the exhaust holes 118 extend may be larger (eg, wider) than other fins 110 in the heat sink 106 .

[0067] At 714, according to a specific implementation of the present disclosure, method 700 includes an encapsulation operation. In some specific implementations, the encapsulation operation surrounds the encapsulated electronic power component 401, the adhesive film 900, and at least a portion of the heat sink 106 with an encapsulant (e.g., epoxy molding compound) to complete the manufacture of the power module 400.

[0068] As described above, various implementations of the power module may utilize liquid solder 114 to directly couple the electronic power component 101 to the heat sink 106 to avoid adding thermal interface materials. Because the liquid solder 114 remains in a liquid phase during operation of the power module, the containment of the liquid solder 114 can be achieved by forming a cavity 113 between the opposing surface and the peripheral wall and then injecting the liquid solder 114 into the cavity 113 through a hole in the heat sink 106. The use of liquid solder 114 avoids the interface coupling problems encountered by current structures.

[0069] 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 exist. 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 coupled to ..., the element shown as directly on the element, directly connected or directly coupled 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.

[0070] As used in this specification, unless the context clearly indicates a particular case, the singular form may include the plural form. In addition to the orientation shown in the drawings, spatial 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. In some specific implementations, the relative terms above and below may include vertically above and vertically below, respectively. In some specific implementations, the term adjacent can include lateral adjacent or horizontal adjacent.

[0071] 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.

[0072] 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, 200, 300), comprising: Electronic power components (101, 201, 301); A heat sink (106) having a base plate (108) and a plurality of heat sinks (110); A peripheral wall (112) extending from a surface of the substrate (108) and disposed between the electronic power component (101) and the heat sink (106); an injectable conductive component (114) disposed in a cavity (113) defined by the electronic power component (101), the substrate (108) and the peripheral wall (112); and An encapsulant (120) is disposed around the electronic power component (101), at least a portion of the heat sink (106), and the peripheral wall (112) to form a power module (100).

2. The device of claim 1, wherein the peripheral wall (112) is integrally formed within the heat sink (106).

3. The device of claim 1, wherein the peripheral wall (112) is an adhesive film comprising at least one of silicone, epoxy, or acrylic materials.

4. The device according to claim 1, wherein the peripheral wall (112) is an elastic seal.

5. The device of claim 1, wherein the heat sink (106) is made of copper.

6. The apparatus of claim 1, wherein the electronic power assembly (101) comprises an electronic component (104) and a single-sided direct bonded copper (DBC) structure (102).

7. The apparatus of claim 1, wherein the electronic power assembly (301) comprises an electronic component (104), a double-sided direct bonded copper (DBC) structure (202), and a spacer (302).

8. The apparatus of claim 1, wherein the injectable conductive component (114) is in a liquid phase at an operating temperature of the electronic power component (101).

9. The device of claim 1, wherein the encapsulant (120) is an epoxy molding compound (EMC).

10. The apparatus of claim 1, further comprising a cover plate (502) over the electronic power assembly (101), wherein the cover plate (502) is fixed to a lid (408) on the base plate (108).

11. The apparatus of claim 1, further comprising a clip assembly (506) above the electronic power assembly (101), wherein the clip assembly (506) is secured to a cover (408) on the base plate (108).

12. The apparatus of claim 1, wherein the heat sink (106) includes an opening (116) having a plug (1200) disposed therein.

13. The apparatus of claim 12, wherein the opening (116) extends through the heat sink (110) and through the base plate (108).

14. An apparatus (600), comprising: A heat sink (106) having a base plate (108) and a plurality of heat sink structures (610); a first power submodule (500) coupled to a top surface of the substrate (108); a second power submodule (500) coupled to the top surface of the substrate (108); a first peripheral wall (412), the first peripheral wall being located between the first power submodule (500) and a first heat sink structure among the plurality of heat sink structures (610), the first peripheral wall (412) extending from a top surface of the substrate (108); a second peripheral wall (412), the second peripheral wall being located between the second power submodule (500) and a second heat sink structure among the plurality of heat sink structures (610), the second peripheral wall (412) extending from the top surface of the substrate (108); and An injectable conductive component (114) is disposed between the first power submodule (500) and the substrate (108), and the injectable conductive component (114) is surrounded by the first peripheral wall (412).

15. The device of claim 14, wherein the first peripheral wall (412) and the second peripheral wall (412) are elastic seals.

16. The apparatus of claim 14, further comprising a cover plate (602) coupled to the first power submodule (500) and the second power submodule (500), the cover plate being secured by a plurality of substrate fasteners (504).

17. The device of claim 16, further comprising an encapsulant (120) formed around at least a portion of the cover plate (602), the first power submodule (500) and the second power submodule (500), the substrate (108), and the plurality of heat sink structures (610).

18. A method (700), comprising: forming a cavity (113), a first hole (116), and a second hole (118) in a heat sink (106); coupling the electronic power component (101) to the heat sink (106) using an adhesive (112); injecting a conductive component (114) into the cavity (113) through the first hole (116); and The first hole (116) and the second hole (118) are sealed.

19. The method of claim 18, wherein sealing the first hole (116) and the second hole (118) comprises: A first plug (1200) is installed in the first hole (116) and a second plug (1200) is installed in the second hole (118).

20. The method of claim 18, wherein sealing the first hole (116) and the second hole (118) comprises: The heat sink (106) is clamped to the electronic power assembly (101) using a clip (428).

21. The method of claim 18, wherein the second aperture (118) is an exhaust port, and the method further comprises: A filter (1104) is attached to the exhaust port while injecting the conductive component (114).

22. The method according to claim 18, further comprising: An encapsulant (120) is formed around the electronic power component (101) and the heat sink (106).

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