Power module for a power electronic device, power electronic device and manufacturing method

Abstract

The invention relates to a power module for a power electronic device, said power module comprising at least: at least one power semiconductor component; a substrate on which the power semiconductor assembly is fixedly arranged; and the heat conduction structure is used as a packaging part to directly coat the power semiconductor assembly. The invention also relates to a corresponding power electronic device and to a corresponding production method for a power module. The heat-conducting property can be improved, so that the optimized working efficiency is realized. In addition, the power module has a reduced number of components and can be manufactured in a cost-effective manner.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductors, and in particular to a power module for power electronic equipment. The present invention also relates to a corresponding power electronic equipment and a corresponding manufacturing method for the power module. Background Art

[0002] At present, as power electronic equipment develops towards miniaturization, high performance and high integration, power modules used in power electronic equipment, as key components, package power semiconductor components into a whole according to certain functional combinations and provide electrical and mechanical connections to simplify system integration. Power modules have the advantages of small size and high power density, so they are widely used in vehicles, industrial equipment, household appliances and other fields.

[0003] In existing power modules, power semiconductor components are usually encapsulated in resin materials, and the substrate of the power module is welded or laminated to a heat sink, which is, for example, a metal plate immersed in a coolant. When the power module is running, part of the electrical energy supplied to the power semiconductor components will be converted into heat. If the heat cannot be discharged smoothly, it will accumulate rapidly and significantly increase the temperature of the power module, thereby reducing the working efficiency of the power electronic equipment, causing thermal failure and even fire and explosion. In response to this, in existing power modules, the heat of the power semiconductor components of the power module is transferred to the coolant through a heat sink, thereby achieving cooling of the power module. However, due to the thermal resistance of the heat sink itself and the solder paste or laminated material between the substrate and the heat sink, the heat conductivity of the heat sink is low and cannot effectively cool the power module in the operating mode. Summary of the invention

[0004] Therefore, the object of the present invention is to provide an improved power module for power electronic equipment, which has improved thermal conductivity and thus achieves optimized operating efficiency. In addition, the power module has a reduced number of components and can be manufactured cost-effectively. The object of the present invention is also to provide a power electronic equipment and a method for manufacturing a power module.

[0005] According to a first aspect of the present invention, a power module for a power electronic device is provided, wherein the power module at least comprises:

[0006] - at least one power semiconductor component;

[0007] - a substrate on which the power semiconductor components are fixedly arranged; and

[0008] - a heat-conducting structure, which serves as a packaging part and directly covers the power semiconductor component.

[0009] Compared with the prior art, in the power module according to the present invention, the heat-conducting structure directly covers the power semiconductor component as a packaging part, so that the power module can be completely immersed in the coolant and the heat generated by the power semiconductor component is directly discharged into the coolant through the heat-conducting structure, thereby shortening the heat conduction path and improving the heat conduction performance, thereby effectively cooling the power module in the operating mode and improving the working efficiency. In addition, the heat sink of the existing power module that is welded or laminated to the substrate can be eliminated, which can reduce the number of parts and process steps of the power module, thereby realizing cost-effective manufacturing of the power module.

[0010] Exemplarily, the power module is configured to be suitable for being directly immersed in a coolant for the power module, so that at least the heat conducting structure is in direct contact with the coolant.

[0011] Exemplarily, the thermally conductive structure is made of an insulating polymer composite material with enhanced thermal conductivity, the polymer composite material having an inorganic filler; and / or the thermal conductivity of the thermally conductive structure is greater than 10 W / (m·K), preferably greater than 20 W / (m·K).

[0012] Exemplarily, the weight percentage of the inorganic filler in the polymer composite is less than 50 wt.%; and / or, the polymer composite is composed of cellulose nanofibers and boron nitride nanotubes, wherein the weight percentage of the boron nitride nanotubes as the inorganic filler is 25 wt.%.

[0013] Exemplarily, the heat conducting structure is provided with heat conducting ribs, and the heat conducting ribs are configured to protrude on the outer surface of the heat conducting structure.

[0014] Exemplarily, the substrate is made of the same material as the heat-conducting structure; and / or the power semiconductor component is fixed to the substrate by welding or bonding; and / or a plurality of the power semiconductor components are integrated and arranged on the substrate at intervals from each other; and / or the substrate is exposed from the heat-conducting structure and / or is flush with the end face of the heat-conducting structure.

[0015] According to a second aspect of the present invention, there is provided a power electronic device, wherein the power electronic device at least comprises:

[0016] - a housing having a receiving chamber;

[0017] - at least one power module according to the invention, said power module being arranged in said receiving chamber; and

[0018] A coolant is filled in the receiving chamber, in which coolant the power module is at least partially immersed.

[0019] Exemplarily, the power module is completely immersed in the coolant; and / or the substrate of the power module is directly fixed on the housing; and / or the housing is made of metal material; and / or the power electronic device is constructed as an inverter or a rectifier.

[0020] According to a third aspect of the present invention, a method for manufacturing a power module according to the present invention is provided, wherein the manufacturing method comprises at least the following steps:

[0021] S1: providing at least one power semiconductor component and a substrate;

[0022] S2: fixing the power semiconductor component on the substrate;

[0023] S3: Injection-molding the power semiconductor component with an insulating polymer composite material having enhanced thermal conductivity, so that the encapsulation portion formed by the polymer composite material functions as a thermally conductive structure.

[0024] Exemplarily, the substrate is made of the polymer composite material; and / or, in step S2, the power semiconductor component is welded or bonded to the substrate; and / or, in step S3, the power semiconductor component and the substrate are encapsulated by injection molding the polymer composite material so that the substrate is exposed from the heat-conducting structure and / or is flush with the end surface of the heat-conducting structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0026] Figure 1 A schematic diagram of a power electronics device having a power module according to an exemplary embodiment of the present invention is shown;

[0027] Figure 2 A schematic flow chart of a method for manufacturing a power module according to an exemplary embodiment of the present invention is shown. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of protection of the present invention. Here, for the sake of brevity, elements with the same reference numerals are only marked once in the drawings.

[0029] In this specification, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate, or the internal communication of two elements. For ordinary technicians in this field, the meanings of the above terms in this disclosure can be understood according to the circumstances.

[0030] Figure 1 A schematic diagram of a power electronic device 100 having a power module 10 according to an exemplary embodiment of the present invention is shown. Here, the power electronic device 100 is configured, for example, as an inverter for converting direct current into alternating current. However, it is also conceivable that the power electronic device 100 is configured as other electrical devices that are considered appropriate by a person skilled in the art, such as a rectifier or a transformer.

[0031] like Figure 1 As shown, the power electronic device 100 includes at least one, in particular multiple power modules 10 and a shell 20, wherein the shell forms a receiving chamber 21, and the power module 10 is arranged in the receiving chamber, wherein the multiple power modules 10 are connected to each other in series and parallel to meet different current and voltage specifications.

[0032] like Figure 1 As shown, the power module 10 includes at least one, in particular a plurality of power semiconductor components 11, which are made of power semiconductor materials and are configured for power control and power conversion. Exemplarily, the power semiconductor components 11 may include semiconductor elements such as diodes, insulated gate bipolar transistors (IGBTs), MOSFETs (metal oxide semiconductor field effect transistors), and thyristors. Here, different combinations of power semiconductor components 11 may be selected according to actual needs to achieve the performance requirements of the power module 10.

[0033] like Figure 1 As shown, the power module 10 includes a substrate 12, on which a power semiconductor component 11 is fixedly arranged. In particular, a plurality of power semiconductor components 11 are spaced apart and integratedly arranged on the substrate 12, wherein at least a portion of the heat generated by the power semiconductor component 11 needs to be conducted through the substrate 12, and the power semiconductor component 11 is insulated from the external environment by the substrate 12 and avoids generating stray inductance, so that the material of the substrate 12 should have good thermal conductivity, insulation performance, low dielectric constant and certain mechanical strength. Typically, the substrate 12 is made of ceramic material, such as aluminum oxide. However, other materials that are considered meaningful by those skilled in the art, such as silicon nitride or aluminum nitride, can also be considered.

[0034] For example, Figure 1As shown, the power semiconductor component 11 is fixed on the substrate 12 in a soldering manner. For this purpose, a metal coating 13 is applied on the substrate 12, and the metal coating is, for example, a copper coating or an aluminum coating and is conducive to the fixed soldering of the power semiconductor component 11 on the substrate 12. Here, the bonding wire 14 of the power semiconductor component 11 is soldered on the metal coating 13. However, it is also conceivable that the power semiconductor component 11 is fixed on the substrate 12 in an adhesive manner, and an adhesive is provided between the power semiconductor component 11 and the substrate 12.

[0035] like Figure 1 As shown, the power module 10 also includes a heat-conducting structure 15, which directly covers the power semiconductor component 11 as a packaging part 16. Compared with the prior art, the packaging part 16 should have a thermal conductivity that meets the requirements in addition to good insulation performance, so as to function as a heat-conducting structure 15 at the same time. Here, the thermal conductivity of the heat-conducting structure 15 or the packaging part 16 is particularly greater than 10W / (m·K), preferably greater than 20W / (m·K), so as to achieve efficient heat dissipation of the power module 10. Of course, other thermal conductivities that are considered meaningful by those skilled in the art can also be considered. In this case, the metal plate that is fixedly connected to the substrate as a heat sink in the traditional power module can be eliminated and it can be ensured that the power module 10 meets the heat dissipation requirements, thereby achieving simple and cost-effective manufacturing of the power module 10.

[0036] Exemplarily, the heat-conducting structure 15 is made of an insulating polymer composite material with enhanced thermal conductivity, wherein the polymer composite material has an inorganic filler, and the thermal conductivity of the polymer composite material is significantly improved by the inorganic filler. In particular, the weight percentage of the inorganic filler in the polymer composite material is less than 50wt.%, so as to avoid a significant decrease in the mechanical properties of the polymer composite material.

[0037] Exemplarily, the polymer composite material of the thermally conductive structure 15 is composed of cellulose nanofibers (CNF) and boron nitride nanotubes (BNNT), wherein the cellulose nanofibers are the matrix material of the polymer composite material, and the weight percentage of the boron nitride nanotubes as the inorganic filler is 25wt.%. Here, both the cellulose nanofibers and the boron nitride nanotubes have high thermal conductivity, high thermal stability, high elastic modulus and insulation, and the strong intermolecular bonding force between the cellulose nanofibers and the boron nitride nanotubes weakens the interface thermal resistance, so that the thermal conductivity of the formed polymer composite material exceeds 20W / (m·K), thereby achieving the desired heat dissipation effect of the thermally conductive structure 15. Of course, other polymer composite materials that are considered meaningful by those skilled in the art can also be considered, such as composite materials composed of epoxy polymers and modified nanoparticles.

[0038] like Figure 1As shown, the power electronic device 100 further includes a coolant 30 filled in the receiving chamber 21 of the housing 20, and the power module is at least partially directly immersed in the coolant, so that the heat-conducting structure 15 can be directly in contact with the coolant 30. The heat energy generated by the power semiconductor component 11 of the power module 10 can be directly conducted to the coolant 30 through the heat-conducting structure 15 as the packaging part 16, thereby significantly shortening the heat conduction path and improving the heat dissipation effect of the power module. In particular, the power module 10 is completely immersed in the coolant 30, so that the heat-conducting structure 15 is in contact with the coolant 30 on the entire outer circumference.

[0039] For example, Figure 1 As shown, the heat conducting structure 15 is provided with a plurality of heat conducting ribs 17, which are protruding and evenly distributed on the outer surface of the heat conducting structure 15. The heat conducting ribs 17 can increase the contact area between the heat conducting structure 15 and the coolant 30, thereby further improving the thermal conductivity of the power module 10.

[0040] For example, Figure 1 As shown, the substrate 12 is exposed from the heat-conducting structure 15, so that the substrate 12 can be directly abutted and fixed on the housing 20, thereby facilitating the arrangement of the power module 10 in the receiving chamber 21. Here, the heat-conducting structure 15 can surround the substrate 12 in the circumferential direction, so that the substrate 12 is flush with the end face of the heat-conducting structure 15. However, it is also possible that the substrate 12 protrudes relative to the end face of the heat-conducting structure 15, so that the substrate 12 is also in contact with the coolant 30. Here, the housing 20 can be made of metal to discharge the heat conducted to the coolant 30 to the external environment as quickly as possible.

[0041] Figure 2 A schematic flow chart of a method for manufacturing a power module 10 according to an exemplary embodiment of the present invention is shown.

[0042] like Figure 2 As shown, the manufacturing method for the power module 10 according to the present invention comprises at least the following steps:

[0043] S1: providing at least one power semiconductor component 11 and a substrate 12;

[0044] S2: The power semiconductor component 11 is fixedly arranged on the substrate 12;

[0045] S3 : The power semiconductor component 11 is encapsulated by injection molding with an insulating polymer composite material having enhanced thermal conductivity, so that the encapsulation portion 16 formed by the polymer composite material functions as a thermal conductive structure 15 .

[0046] For example, in step S1 , the substrate 12 may be made of a ceramic material, but it is also conceivable that the substrate 12 is made of the same polymer composite material as the heat-conducting structure 15 by injection molding, thereby forming a substrate 12 with enhanced thermal conductivity and insulation.

[0047] For example, in step S2, the power semiconductor component 11 is soldered on the substrate 12, wherein the metal coating 13 is firstly applied on the substrate 12, and then the power semiconductor component 11 and / or the bonding wire 14 are soldered on the metal coating 13. It is also possible to fix the power semiconductor component 11 on the substrate 12 by bonding with an adhesive.

[0048] Exemplarily, in step S3, the power semiconductor component 11 and the substrate 12 are encapsulated by injection molding of the polymer composite material to form the heat-conducting structure 15, wherein the power semiconductor component 11 and the substrate 12 fixed to each other are first placed in the molding cavity of the molding mold and the polymer composite material is injected into the molding cavity, and the molding of the heat-conducting structure 15 is achieved by controlling parameters such as temperature and pressure, and then the power module 10 is manufactured after curing for a preset time. In particular, the substrate 12 is exposed from the heat-conducting structure 15 and is flush with the end surface of the heat-conducting structure 15 to simplify the installation of the power module 10 in the power electronic device 100.

[0049] The above explanation of the embodiments only describes the invention within the framework of the examples. Of course, the individual features of the embodiments can be freely combined with one another as long as it makes technical sense, without departing from the framework of the invention.

[0050] Other advantages and alternative embodiments of the present invention are obvious to those skilled in the art. Therefore, the present invention in its broader sense is not limited to the specific details, representative structures and exemplary embodiments shown and described. On the contrary, those skilled in the art can make various modifications and substitutions without departing from the basic spirit and scope of the present invention.

Claims

1. A power module (10) for a power electronic device (100), characterized in that: The power module (10) comprises at least: - at least one power semiconductor component (11); - a substrate (12), on which the power semiconductor component (11) is fixedly arranged; and - a heat-conducting structure (15), which directly covers the power semiconductor component (11) as a packaging part (16).

2. The power module (10) according to claim 1, characterized in that: The power module (10) is configured to be directly immersed in a coolant (30) for the power module (10), so that at least the heat-conducting structure (15) is in direct contact with the coolant (30).

3. The power module (10) according to claim 1 or 2, characterized in that: The thermally conductive structure (15) is made of an insulating polymer composite material with enhanced thermal conductivity, the polymer composite material having an inorganic filler; and / or The thermal conductivity of the heat-conducting structure (15) is greater than 10 W / (m·K), preferably greater than 20 W / (m·K).

4. The power module (10) according to claim 3, characterized in that: The weight percentage of the inorganic filler in the polymer composite material is less than 50 wt.%; and / or The polymer composite material consists of cellulose nanofibers and boron nitride nanotubes, wherein the weight percentage of the boron nitride nanotubes as the inorganic filler is 25 wt.%.

5. The power module (10) according to any one of the preceding claims, characterized in that The heat conducting structure (15) is provided with heat conducting ribs (17) which are designed to protrude on the outer surface of the heat conducting structure (15).

6. The power module (10) according to any one of the preceding claims, characterized in that The substrate (12) is made of the same material as the heat-conducting structure (15); and / or The power semiconductor component (11) is fixed on the substrate (12) by welding or bonding; and / or A plurality of the power semiconductor components (11) are arranged on the substrate (12) in an integrated manner and spaced apart from each other; and / or The substrate (12) is exposed from the heat-conducting structure (15) and / or is flush with an end surface of the heat-conducting structure (15).

7. A power electronic device (100), characterized in that: The power electronic device (100) comprises at least: - a housing (20) having a receiving chamber (21); - at least one power module (10) according to any one of claims 1 to 6, which is arranged in the receiving chamber (21); and A coolant (30) filled in the receiving chamber (21), the power module (10) being at least partially immersed in the coolant (30).

8. The power electronic device (100) according to claim 7, characterized in that: The power module (10) is completely immersed in the coolant (30); and / or The substrate (12) of the power module (10) is directly abutted and fixed on the housing (20); and / or The housing (20) is made of metal material; and / or The power electronics device (100) is designed as an inverter or a rectifier.

9. A method for manufacturing a power module (10) according to any one of claims 1 to 6, characterized in that: The manufacturing method comprises at least the following steps: S1: providing at least one power semiconductor component (11) and a substrate (12); S2: fixing the power semiconductor component (11) on the substrate (12); S3: Injection-molding the power semiconductor component (11) with an insulating polymer composite material having enhanced thermal conductivity, so that the encapsulation portion (15) formed by the polymer composite material functions as a thermally conductive structure (16).

10. The manufacturing method according to claim 9, characterized in that: The substrate (12) is made of the polymer composite material; and / or In step S2, the power semiconductor component (11) is welded or bonded to the substrate (12); and / or In step S3, the power semiconductor component (11) and the substrate (12) are encapsulated by injection molding of the polymer composite material, so that the substrate (12) is exposed from the heat conducting structure (15) and / or is flush with the end surface of the heat conducting structure (15).

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