Power module and power conversion equipment

Abstract

The utility model provides a power module and power conversion equipment. The power module comprises a packaging shell, a packaging substrate and a plurality of chips. The packaging shell is provided with an opening. The packaging substrate comprises a ceramic substrate, a first metal layer and a second metal layer, the first metal layer is arranged on the surface of the side, facing the opening, of the ceramic substrate, the second metal layer is arranged on the surface of the side, deviating from the opening, of the ceramic substrate, and the chips are arranged on the second metal layer. A heat conduction film is arranged on the surface of the side, away from the ceramic substrate, of the first metal layer and used for being connected with a radiator. The heat conduction film can realize a connection function and a heat dissipation function at the same time, so that the packaging substrate and the radiator do not need to be connected by adopting a welding or sintering process, the high-temperature resistance requirement of the power module is reduced, and the problems of stress concentration and warping of the power module caused by the welding or sintering process and the like can be solved. In addition, large-area heat dissipation between the packaging substrate and the radiator can be achieved through the heat conduction film, so that the heat dissipation efficiency of the power module is improved.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to a power module and a power conversion device. Background Technology

[0002] When power conversion equipment is operating, the power modules typically generate a significant amount of heat. To prevent the power modules from overheating and malfunctioning, this heat must be dissipated promptly and effectively. Therefore, the heat dissipation design of the power modules is one of the key aspects of the structural design of power conversion equipment.

[0003] Existing power conversion devices include a power module and a heat sink. The heat sink contacts the power module and is used to dissipate heat from the power module. The power module includes a package and a double-sided copper-clad ceramic substrate located within the package. The double-sided copper-clad ceramic substrate includes a ceramic substrate and metal layers disposed on both sides of the ceramic substrate. An opening is provided on the side of the package facing the heat sink, thereby exposing one metal layer of the double-sided copper-clad ceramic substrate to the opening and allowing heat exchange with the heat sink.

[0004] Typically, the metal layer of a ceramic substrate is connected to the heat sink via brazing. However, due to the high temperature of brazing and the varying coefficients of thermal expansion among the components within the power module, the different layers of the double-sided copper-clad ceramic substrate, and the heat sink, significant stresses are generated within the power module, the heat sink, and between the power module and the heat sink as the power module's temperature changes. This can cause warping of the components. For example, at the interface between the metal layer and the heat sink, significant stress can lead to cracks that may propagate further, severely impacting the connection strength between the metal layer and the heat sink, as well as the heat dissipation efficiency of the heat sink for the power module. Utility Model Content

[0005] This application provides a power module and a power conversion device to improve the stress concentration and warping problems of power modules caused by processes such as welding or sintering.

[0006] In a first aspect, this application provides a power module. The power module includes a package shell, a package substrate, and multiple chips. Specifically, the package shell has an opening. The package substrate includes a ceramic substrate, a first metal layer, and a second metal layer. The first metal layer is disposed on the surface of the ceramic substrate facing the opening, and the second metal layer is disposed on the surface of the ceramic substrate facing away from the opening. The multiple chips are disposed on the second metal layer. A thermally conductive film is disposed on the surface of the first metal layer facing away from the ceramic substrate, and the thermally conductive film is used to connect to a heat sink.

[0007] In the power module of this application, the packaging substrate is a double-sided metal-coated ceramic substrate. One side of the metal layer is connected to the heat sink via a thermally conductive film, and heat exchange can occur between the film and the heat sink. Therefore, the thermally conductive film can simultaneously perform both connection and heat dissipation functions. This eliminates the need for welding or sintering processes between the packaging substrate and the heat sink, reducing the high-temperature resistance requirements of the power module and mitigating stress concentration and warping issues caused by welding or sintering processes. Furthermore, this structure reduces the risk of interface cracking and enables large-area heat dissipation between the packaging substrate and the heat sink, thereby improving the heat dissipation efficiency of the power module.

[0008] In one embodiment, the thermal conductivity of the thermal conductive film is greater than or equal to 10 W / (mK) to accelerate heat exchange between the packaging substrate and the heat sink.

[0009] In one embodiment, the power module may further include the aforementioned heat sink. The packaging substrate, the aforementioned plurality of chips, and the thermally conductive film may be located inside the packaging shell, while the heat sink is located outside the packaging shell. Furthermore, the packaging shell has an opening through which the thermally conductive film is exposed and connected to the heat sink. In this embodiment, the thermally conductive film may be co-packaged with the packaging substrate and the aforementioned plurality of chips before being connected to the heat sink. Therefore, the devices within the packaging shell are relatively independent of the heat sink; the power module may be connected to a separate heat sink, or the power module may share a heat sink with other devices or modules of the power conversion device.

[0010] In another embodiment, the power module may further include the aforementioned heat sink. The packaging substrate, the aforementioned plurality of chips, and the thermal conductive film may be located within the packaging shell, with a portion of the heat sink located within the packaging shell and connected to the thermal conductive film, and another portion of the heat sink extending out of the packaging shell through an opening. In this embodiment, the heat sink, thermal conductive film, packaging substrate, and the aforementioned plurality of chips can be packaged together; therefore, the power module can have its own built-in heat sink.

[0011] In one embodiment, the heat sink includes a heat sink plate and a plurality of heat dissipation fins. The plurality of heat dissipation fins are located on the surface of the heat sink plate opposite to the thermally conductive film, and extend in a direction away from the thermally conductive film. In this embodiment, the power module can employ air cooling, where airflow carries away the heat from the heat sink.

[0012] In another embodiment, the heat sink is a liquid cooling plate. In this embodiment, the power module can use liquid cooling to dissipate heat, by the flow of the cooling medium within the liquid cooling plate carrying away the heat from the thermally conductive film.

[0013] In one embodiment, the material of the thermally conductive film may include silicone-based thermally conductive adhesive or epoxy resin-based thermally conductive adhesive, thereby forming a thermally conductive film by directly applying the thermally conductive adhesive between the first metal layer and the heat sink. This method is simple to operate and does not require high-temperature conditions, thus avoiding large stress changes between the first metal layer and the heat sink. Alternatively, the thermally conductive film may be a sheet-like film placed between the first metal layer and the heat sink, and the film is bonded to the surfaces of the first metal layer and the heat sink respectively by applying a set temperature and pressure.

[0014] In one embodiment, the first metal layer and the second metal layer are copper layers, meaning the packaging substrate is a double-sided copper-clad ceramic substrate. Alternatively, in another embodiment, the first metal layer and the second metal layer are aluminum layers, meaning the packaging substrate is a double-sided aluminum-clad ceramic substrate.

[0015] Secondly, this application also provides a power conversion device. The power conversion device includes a circuit board and a power module as described in the first aspect, with the power module electrically connected to the circuit board. In the power conversion device of this application, the power module and the heat sink do not need to be connected using high-temperature processes such as welding or sintering, thereby improving the stress concentration and warping problems caused by welding or sintering processes on the power module. This improves the structural strength of the power conversion device while also achieving good heat dissipation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a power conversion device according to an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of a power module according to an embodiment of this application;

[0018] Figure 3 This is a schematic diagram of a power module according to another embodiment of this application;

[0019] Figure 4 This is a schematic diagram of a power module according to another embodiment of this application;

[0020] Figure 5 This is a schematic diagram of a power module according to another embodiment of this application.

[0021] Figure label:

[0022] 10-Power Conversion Equipment

[0023] 11-Circuit Board

[0024] 12-Power Module

[0025] 13-pin

[0026] 14-Radiator

[0027] 121-Package Case

[0028] 122-Packaging Substrate

[0029] 123-Chip

[0030] 124-thermal conductive film

[0031] 141-Heat Discharge Plate

[0032] 142-heat dissipation teeth

[0033] 143-Cooling flow channel

[0034] 1221-Ceramic Substrate

[0035] 1222 - First Metal Layer

[0036] 1223 - Second Metal Layer Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0038] To facilitate understanding of the power module and power conversion device provided in this application embodiment, their application scenarios are described below. The power module of this application is a semiconductor device that converts the voltage, current, and frequency of a power supply, and is a core device for power conversion. Power modules can be applied to power conversion devices in scenarios such as photovoltaic power generation equipment, electric vehicles, and energy storage equipment. Depending on the application field, power modules can be classified into automotive-grade power modules, industrial power modules, etc. In electric vehicles, power modules can be used for AC-DC conversion or DC conversion. For example, power modules can be applied to on-board chargers (OBCs) and motor control units (MCUs). In photovoltaic power generation equipment, power modules can be applied to power conversion devices. Power conversion devices can convert DC power generated by solar panels into AC power for output. In energy storage devices, power modules can be used to convert external AC power into DC power for storage in battery packs, or to convert DC power output from battery packs into AC power for output to AC loads.

[0039] Figure 1 This is a schematic diagram of a power conversion device according to an embodiment of this application. Figure 1As shown, the power conversion device 10 specifically includes a circuit board 11 and a power module 12. The power module 12 can be located on one side of the circuit board 11, and the power module 12 is electrically connected to the circuit board 11 via pins 13. The power module 12 includes a package shell 121 and a package substrate 122. The package substrate 122 is located inside the package shell 121 and has multiple semiconductor devices disposed thereon. In practical applications, the package substrate 122 can be a double-sided metal-ceramic substrate. The power conversion device 10 also includes a heat sink 14, which is located on the side of the package substrate 122 opposite to the circuit board 11.

[0040] In existing power conversion devices, the power module's package typically has an opening, with the heat sink located outside the package. The metal layer of the package substrate is exposed through the opening and is soldered or sintered with the heat sink. During soldering or sintering, solder or sintering materials (such as solder, silver sintering materials, or micro / nano metal sintering materials) form a metal bonding layer between the metal layer of the package substrate and the heat sink. However, because the chip, the various layers of the package substrate, and the heat sink are made of different materials, the coefficients of thermal expansion of the different components in the power module vary.

[0041] During the actual welding or sintering process, the power module will experience alternating cycles of temperature rise and fall. When the temperature of the power module changes, due to the different degrees of expansion of the various layers of the packaging substrate, power devices, metal interconnects, and heat sinks within the power module, large stresses are generated in the various layers of the packaging substrate, power devices, metal interconnects, and heat sinks, resulting in warping deformation.

[0042] For example, stress concentrated between the metal layer and the metal interconnect layer of the packaging substrate can cause cracks at the interconnect interface, and these cracks may propagate along the flat surface of the metal layer, leading to interface deterioration. This not only reduces the connection strength between the metal layer and the heat sink, but also reduces heat exchange between them, thus decreasing heat dissipation efficiency.

[0043] In view of this, this application provides a power module and a power conversion device to improve the stress concentration and warping problems of the power module caused by processes such as welding or sintering.

[0044] It should be noted that the terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.

[0045] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0046] In this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0047] Furthermore, in this article, directional terms such as "top," "bottom," "upper," and "lower" are defined relative to the orientation of the structure as shown in the attached drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the structure.

[0048] Figure 2 This is a schematic diagram of a power module according to one embodiment of this application. Figure 3 This is a schematic diagram of a power module according to another embodiment of this application. Figure 2 and Figure 3 As shown, the power module 12 also includes multiple chips 123. The packaging substrate 122 is a double-sided metal-coated ceramic substrate, specifically including a ceramic substrate 1221, a first metal layer 1222, and a second metal layer 1223. The packaging shell 121 has an opening. The first metal layer 1222 is disposed on the surface of the ceramic substrate 1221 facing the opening, and the second metal layer 1223 is disposed on the surface of the ceramic substrate 1221 away from the opening. The multiple chips 123 are disposed on the second metal layer 1223. A thermally conductive film 124 is disposed on the surface of the first metal layer 1222 away from the ceramic substrate 1221. The thermally conductive film 124 can be used to connect with the heat sink 14.

[0049] In the embodiments of this application, thermally conductive adhesive may be used to fill the space between the package shell 121 and the chip 123, and between the package shell 121 and the package substrate 122. This allows the heat from the device to be conducted to the package shell 121 and dissipated outwards, while also providing insulation protection and mechanical explosion-proof properties for the device. Alternatively, the package shell 121 and the chip 123 may be in direct contact, and the package shell 121 and the package substrate 122 may also be in direct contact. In other words, no other materials are used to fill the space between the package shell 121 and the chip 123, or between the package shell 121 and the package substrate 122. This simplifies the manufacturing process and material costs of the power module 12, and reduces the thermal resistance between the device and the package shell 121. Furthermore, the package shell 121 may directly encapsulate the device, providing mechanical support.

[0050] The aforementioned packaging substrate 122 can be a double-sided copper-clad ceramic substrate or a double-sided aluminum-clad ceramic substrate. In one embodiment, the first metal layer 1222 and the second metal layer 1223 are copper layers, that is, the packaging substrate 122 is a double-sided copper-clad ceramic substrate. In another embodiment, the first metal layer 1222 and the second metal layer 1223 are aluminum layers, that is, the packaging substrate 122 is a double-sided aluminum-clad ceramic substrate.

[0051] In the power module 12 of this application, the first metal layer 1222 can be connected to the heat sink 14 through the thermally conductive film 124, and heat exchange can also occur between the thermally conductive film 124 and the heat sink 14. Therefore, the thermally conductive film 124 can simultaneously perform both connection and heat dissipation functions, eliminating the need for welding or sintering processes to connect the package substrate 122 and the heat sink 14, thereby reducing the high-temperature resistance requirements of the power module 12. This further improves the stress concentration and warping problems caused by welding or sintering processes in the power module 12. Furthermore, the thermally conductive film 124 reduces the risk of cracking at the connection interface, thereby achieving large-area heat dissipation between the package substrate 122 and the heat sink 14, thus improving the heat dissipation efficiency of the power module 12.

[0052] To accelerate heat exchange between the packaging substrate 122 and the heat sink 14, the thermal conductivity of the thermal conductive film 124 is greater than or equal to 10 W / (mK).

[0053] In the above embodiments, the material of the thermally conductive film 124 may specifically include silicone-based thermally conductive adhesive or epoxy resin-based thermally conductive adhesive. In one embodiment, when manufacturing the power module 12, the thermally conductive film 124 can be formed by directly applying thermally conductive adhesive between the first metal layer 1222 and the heat sink 14. This operation is simple and does not require high-temperature conditions, thus avoiding large stress changes between the first metal layer 1222 and the heat sink 14. In another embodiment, the thermally conductive film 124 itself can be a sheet-like film. When manufacturing the power module 12, this sheet-like film is placed between the first metal layer 1222 and the heat sink 14. By applying a set temperature and pressure, the sheet-like film is connected to the surface of the first metal layer 1222 and the surface of the heat sink 14, respectively.

[0054] like Figure 2 As shown, in one embodiment, the power module 12 can employ air cooling, where airflow carries away the heat from the heat sink 14. Specifically, the heat sink 14 includes a heat sink 141 and a plurality of heat dissipation teeth 142. The aforementioned plurality of heat dissipation teeth 142 are located on the surface of the heat sink 141 facing away from the thermal conductive film 124, and the aforementioned plurality of heat dissipation teeth 142 extend in a direction away from the thermal conductive film 124.

[0055] like Figure 3 As shown, in another embodiment, the power module 12 can employ liquid cooling. The heat sink 14 is a liquid cooling plate, and a cooling channel 143 is provided inside the liquid cooling plate. The outer wall of the cooling channel 143 can be connected to the thermally conductive film 124, and the heat of the thermally conductive film 124 can be carried away by the flow of the cooling medium in the cooling channel 143.

[0056] The heat sink 14 is located at least partially within the package 121 of the power module 12.

[0057] like Figure 2 and Figure 3 As shown, in one embodiment, the heat sink 14 can be entirely located outside the package housing 121. The package substrate 122, the aforementioned plurality of chips 123, and the thermal conductive film 124 can be located inside the package housing 121, with the thermal conductive film 124 exposed at the opening of the package housing 121, and the portion of the thermal conductive film 124 exposed at the opening can be connected to the heat sink 14. In this embodiment, the thermal conductive film 124 can be co-packaged with the package substrate 122 and the aforementioned plurality of chips 123 before being connected to the heat sink 14. Therefore, the devices inside the package housing 121 are relatively independent of the heat sink 14, and the power module 12 can be connected to a separate heat sink 14, or the power module 12 can share a heat sink 14 with other devices or modules of the power conversion device.

[0058] Figure 4 This is a schematic diagram of a power module according to another embodiment of this application. Figure 5This is a schematic diagram of a power module according to another embodiment of this application. Figure 4 and Figure 5 As shown, in another embodiment, the heat sink 14 may be partially located within the package housing 121. The package substrate 122, the aforementioned plurality of chips 123, and the thermal conductive film 124 may be located within the package housing 121. A portion of the heat sink 14 may be located within the package housing 121, and the portion of the heat sink 14 located within the package housing 121 may be connected to the thermal conductive film 124. The other portion of the heat sink 14 extends out of the package housing 121 through an opening. In this embodiment, the heat sink 14, the thermal conductive film 124, the package substrate 122, and the aforementioned plurality of chips 123 may be packaged together; therefore, the power module 12 may have its own heat sink 14. Specifically, as... Figure 4 As shown, the heat sink 141 of the heat sink 14 is located inside the encapsulation shell 121, and multiple heat dissipation teeth 142 are located outside the encapsulation shell 121. Figure 5 As shown, in the liquid cooling plate, one sidewall of the cooling channel 143 may be located inside the encapsulation shell 121, while the cooling channel 143 and other sidewalls may be located outside the encapsulation shell 121.

[0059] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power module, characterized in that, It includes a package shell, a package substrate, and multiple chips, among which: The packaging shell has an opening; the packaging substrate includes a ceramic substrate, a first metal layer and a second metal layer, the first metal layer is disposed on the surface of the ceramic substrate facing the opening, the second metal layer is disposed on the surface of the ceramic substrate away from the opening, and the plurality of chips are disposed on the second metal layer. A thermally conductive film is provided on the surface of the first metal layer facing away from the ceramic substrate, and the thermally conductive film is used to connect with the heat sink.

2. The power module as described in claim 1, characterized in that, The thermal conductivity of the thermal conductive film is greater than or equal to 10 W / (mK).

3. The power module as described in claim 1 or 2, characterized in that, The power module also includes the heat sink. The packaging substrate, the plurality of chips and the thermal conductive film are located inside the packaging shell, and the heat sink is located outside the packaging shell. The packaging shell is provided with an opening, and the thermal conductive film is exposed through the opening and connected to the heat sink.

4. The power module as described in claim 3, characterized in that, The heat sink includes a heat sink plate and a plurality of heat dissipation teeth, which are located on the surface of the heat sink plate away from the thermal conductive film and extend in a direction away from the thermal conductive film.

5. The power module as described in claim 3, characterized in that, The radiator is a liquid cooling plate.

6. The power module as described in claim 1 or 2, characterized in that, The power module also includes the heat sink. The packaging substrate, the plurality of chips and the thermal conductive film are located inside the packaging shell. A portion of the heat sink is located inside the packaging shell and connected to the thermal conductive film. Another portion of the heat sink extends out of the packaging shell through the opening.

7. The power module as described in claim 6, characterized in that, The heat sink includes a heat sink plate and a plurality of heat dissipation teeth, which are located on the surface of the heat sink plate away from the thermal conductive film and extend in a direction away from the thermal conductive film.

8. The power module as described in claim 6, characterized in that, The radiator is a liquid cooling plate.

9. The power module as described in claim 1 or 2, characterized in that, The material of the thermal conductive film includes silicone-based thermal conductive adhesive or epoxy resin-based thermal conductive adhesive.

10. The power module as described in claim 1 or 2, characterized in that, The first metal layer and the second metal layer are copper layers; or, the first metal layer and the second metal layer are aluminum layers.

11. A power conversion device, characterized in that, It includes a circuit board and a power module as described in any one of claims 1 to 10, wherein the power module is electrically connected to the circuit board.

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