Power module capable of enhancing heat dissipation and power conversion equipment

Abstract

The utility model discloses a power module capable of enhancing heat dissipation and power conversion equipment. The power module comprises a bottom plate, a substrate, a chip and a radiator, the bottom plate comprises a first face and a second face which are arranged oppositely, the substrate is fixed to the first face, and the chip is electrically connected with the side, away from the bottom plate, of the substrate. The radiator is located on one side of the second face away from the first face. The surface area of the first face is smaller than that of the second face and smaller than that of the surface of the side, facing the bottom plate, of the radiator. By adopting the heat dissipation scheme of the power module, the heat transferred to the substrate by the chip can be quickly transferred to the second surface from the first surface of the bottom plate and then transferred to the radiator. As the contact area between the bottom plate and the radiator is large, the heat dissipation efficiency of the power module can be improved, possibility is provided for arranging more power devices in the power module, and the power density of the power module can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy, and in particular to a power module and power conversion equipment with enhanced heat dissipation. Background Art

[0002] A power module is a functional module that combines power electrical devices according to certain functions and then plastic-encapsulates or pots them into an integral whole. It is widely used in equipment such as servo motors, frequency converters or inverters.

[0003] Taking inverters as an example, with the continuous advancement of photovoltaic technology, the power carried by inverters is increasing, driving the evolution of power modules within inverters towards higher power density. However, with this increase in power density, the heat generated by the power modules also increases significantly. Excessively high module temperatures can affect operating efficiency and, in severe cases, even damage the modules. Therefore, achieving efficient heat dissipation from power modules has become a key constraint in increasing their power density. Utility Model Content

[0004] The utility model provides a power module and a power conversion device with enhanced heat dissipation, which are used to improve the heat dissipation efficiency of the power module, thereby facilitating the improvement of the power density of the power conversion device.

[0005] In a first aspect, the present invention provides a power module with enhanced heat dissipation, comprising a base plate, a substrate, a chip, and a heat sink. The base plate comprises a first surface and a second surface disposed opposite each other. The substrate is fixed to the first surface, and the chip is located on a side of the substrate facing away from the base plate, and the chip and the substrate are electrically connected. The heat sink is located on a side of the second surface facing away from the first surface. Furthermore, the surface area of the first surface of the base plate is smaller than the surface area of the second surface, and smaller than the surface area of the heat sink facing the base plate. Using the design of the power module provided by the present invention, heat generated by the chip can be transferred to the first surface of the base plate through the substrate. Because the surface area of the first surface of the base plate is smaller than the surface area of the second surface, and smaller than the surface area of the heat sink facing the base plate, the efficiency of heat transfer from the first surface to the second surface of the base plate is improved. Furthermore, because the contact area between the base plate and the heat sink is larger, the efficiency of heat transfer from the substrate to the heat sink is improved, thereby improving the heat dissipation efficiency of the power module, making it possible to install more power devices in the power module, and thus improving the power density of the power module.

[0006] In one possible implementation of the present invention, the second surface of the base plate includes a first meshing portion. The heat sink's surface facing the base plate includes a second meshing portion, which is plugged into the first meshing portion, with the surface of the second meshing portion abutting the surface of the first meshing portion. Because the base plate and heat sink include meshing portions that plug into and contact each other, the contact area between the base plate and heat sink is increased, thereby improving the heat dissipation efficiency of the power module.

[0007] In one possible implementation of the present invention, one of the first and second meshing portions is a protrusion, and the other is a groove. This facilitates the arrangement of the first and second meshing portions, thereby simplifying the processing of the power module.

[0008] When one of the first engaging portion and the second engaging portion is a protrusion, the protrusion may be arranged in various forms.

[0009] For example, the protrusions can be dot-shaped protrusions. This allows the second surface of the base plate to include multiple first engaging portions, the heat sink to include multiple second engaging portions, and the multiple first engaging portions and the multiple second engaging portions to be plugged in and arranged in a one-to-one correspondence. This can help increase the contact area between the base plate and the heat sink, thereby improving the heat transfer efficiency between the base plate and the heat sink.

[0010] In addition, the multiple first engaging portions of the base plate can be arranged in an array, and the multiple second engaging portions of the heat sink can also be arranged in an array. This is conducive to providing a larger number of first engaging portions and second engaging portions, thereby increasing the heat dissipation area between the base plate and the heat sink.

[0011] In the present invention, the above-mentioned point-shaped protrusions can be illustratively prism-shaped protrusions, pyramid-shaped protrusions, prismatic protrusions, frustum-shaped protrusions, conical protrusions, cylindrical protrusions or hemispherical protrusions, or can be point-shaped protrusions of other regular or irregular shapes.

[0012] In another possible implementation of the present invention, the protrusion may be a strip-shaped protrusion. In this implementation, the second surface of the base plate may include multiple first engaging portions, and the heat sink may include multiple second engaging portions. The multiple first engaging portions are then plugged into and arranged in a one-to-one correspondence with the multiple second engaging portions. This facilitates the arrangement of the first and second engaging portions, simplifying the processing of the power module.

[0013] In addition, multiple first meshing portions are arranged side by side, and multiple second meshing portions are arranged side by side, which is conducive to arranging more first meshing portions and second meshing portions, thereby facilitating the increase of the heat dissipation area between the bottom plate and the radiator.

[0014] In the present invention, the cross-sectional shape of the strip-shaped protrusions may be, for example, a trapezoid, a triangle, a rectangle or a semicircle, or may be other regular or irregular strip-shaped protrusions.

[0015] In one possible implementation of the present invention, the power module further includes a thermal interface material layer covering the second surface of the base plate, the surface of the first engaging portion, the surface of the heat sink facing the base plate, and the surface of the second engaging portion. This allows indirect contact between the base plate and the heat sink via the thermal interface material layer, thereby improving the reliability of heat conduction between the base plate and the heat sink.

[0016] In addition, in one implementation, the first engaging portion may include a first contact surface, and the angle between the first contact surface and the second surface includes an obtuse angle. At the same time, the second engaging portion includes a second contact surface, and the angle between the second contact surface and the surface of the heat sink facing the base plate includes an obtuse angle. Moreover, the first contact surface and the second contact surface are abutted by an interface thermal conductive material layer. In this way, the thermal conductivity of the interface thermal conductive material layer can be improved under the greater interface pressure generated by the abutment of the first contact surface and the second contact surface. At the same time, under the action of the above-mentioned interface pressure, the thickness of the interface thermal conductive material layer will also be squeezed very small, which can effectively reduce the thermal resistance between the base plate and the heat sink, thereby improving the heat dissipation effect of the power module.

[0017] In a possible implementation of the present invention, the power module may further include a package body, which wraps the substrate and the chip to achieve packaging protection for the substrate and the chip, thereby improving the structural reliability of the power module.

[0018] In a second aspect, the present invention further provides a power conversion device comprising a circuit board and a power module, wherein the power module is electrically connected to the circuit board. In this power conversion device, the power module has excellent heat dissipation performance, which helps to increase the power density of the power conversion device, thereby improving the power conversion performance of the power conversion device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a photovoltaic power generation system provided by an embodiment of the present utility model;

[0020] Figure 2 A schematic diagram of the structure of a power conversion device provided by an embodiment of the present utility model;

[0021] Figure 3 A schematic diagram of a conventional structure of a power module provided in an embodiment of the present utility model;

[0022] Figure 4 A schematic diagram of the structure of a power module provided by an embodiment of the present utility model;

[0023] Figure 5 for Figure 4 A magnified view of the local structure at A of the structure shown in FIG;

[0024] Figure 6a to Figure 6c Schematic diagrams of several possible structures of the base plate provided in the embodiments of the present utility model;

[0025] Figure 7a to Figure 7d Schematic diagrams of several other possible structures of the base plate provided in the embodiments of the present utility model;

[0026] Figures 8a to 8d Schematic diagrams of several other possible structures of the base plate provided in the embodiments of the present utility model;

[0027] Figure 9 Another structural schematic diagram of the power module provided in an embodiment of the utility model.

[0028] Reference numerals:

[0029] 1000-PV panels; 2000-inverter; 3000-transformer; 4000-grid; 5000-load;

[0030] 100 - power conversion device; 10 - housing; 20 - circuit board; 30 - power module; 31 - substrate; 311 - ceramic substrate; 312 - first metal layer;

[0031] 313 - second metal layer; 32 - chip; 33 - base plate; 331 - first surface; 332 - second surface; 333 - first engaging portion; 3331 - first contact surface;

[0032] 34 - housing; 35 - filling glue; 36 - pins; 37 - plastic packaging material; 38 - cover plate; 40 - heat sink; 41 - second engaging portion; 411 - second contact surface; 50 - interface thermal conductive material layer; 60 - bonding wire. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the embodiments of the present invention are all explained using the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the embodiments of the present invention are only used to illustrate the relative position relationship and do not represent the true proportions.

[0034] It should be noted that the following description sets forth specific details to facilitate understanding of the present invention. However, the embodiments of the present invention can be implemented in a variety of ways other than those described herein, and those skilled in the art may make similar generalizations without departing from the scope of the embodiments of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] Power conversion devices are widely used in scenarios such as photovoltaic power generation systems, energy storage systems, and the powertrain systems of new energy vehicles. They are used to convert current or voltage within the application system. Power conversion devices can include inverters and microinverters in photovoltaic power generation systems, converters in energy storage systems, and motor controllers in the powertrain systems of new energy vehicles.

[0036] Taking photovoltaic power generation system as an example, Figure 1 A schematic diagram of an application scenario of a photovoltaic power generation system provided by an embodiment of the present invention, wherein the photovoltaic power generation system includes a photovoltaic module 1000, an inverter 2000, and a transformer 3000. The photovoltaic module 1000 is a DC power supply composed of solar cells packaged in series or in parallel, and is used to convert sunlight energy into DC electrical energy. The inverter 2000 is a DC-AC power conversion device that can be used to convert the DC power output by the photovoltaic module 1000 into AC power and output it to the transformer 3000. The transformer 3000 is used to transform the AC power output by the inverter 2000 and then integrate it into the AC power grid 4000, thereby achieving grid connection of the photovoltaic power generation system. Alternatively, the AC power output by the inverter 2000 can be output to the load 5000 to power the load 5000.

[0037] Figure 2 A schematic diagram of the structure of a power conversion device provided by an embodiment of the present utility model. Figure 2 As shown, the power conversion device 100 may include a housing 10 and a circuit board 20 and a power module 30 housed in the housing 10, wherein the power module 30 is electrically connected to the circuit board 20. The circuit board 20 may be a printed circuit board (PCB), a flexible printed circuit (FPC), or a rigid-flexible circuit board. The power module 30 is a core component of the power conversion device 100 for realizing the power conversion function. The power module 30 may include multiple ports, such as input positive and negative ports, output positive and negative ports, power supply positive and negative ports, etc. These ports are electrically connected to the circuit board 20 through pins, thereby utilizing the circuit board 20 to provide current or voltage input and output, power supply, and other functions for the power module 30.

[0038] The power module 30 may include various electrical components such as chips, inductors, resistors or capacitors. These electrical components are connected according to a certain functional combination and then packaged into a whole through a packaging process. Common power module 30 packaging processes include housing packaging, molding packaging, etc. Among them, housing packaging is a packaging method that uses a plastic shell and a carrier substrate carrying the above-mentioned electrical components to form a receiving cavity, and injects silicone gel into the cavity to protect the electrical components. Molding packaging is a packaging method that places the carrier substrate carrying the electrical components into a special injection mold, uses a softened epoxy resin or other plastic packaging material as the packaging material, and under certain pressure and temperature conditions, encapsulates and wraps the electrical components to protect the internal components.

[0039] Taking the inverter as an example of power conversion equipment, the continuous development of photovoltaic technology has led to the increasing power requirements of inverters, which has prompted the development and evolution of power modules within inverters towards higher power density. This has placed higher requirements on heat dissipation during operation.

[0040] You can continue to refer to Figure 2 Currently, the power module 30 usually leads the port out from one side through pins, and uses the other side for heat dissipation. Figure 3 , Figure 3 A schematic diagram of a conventional structure of a power module provided in an embodiment of the present utility model. In conventional designs, the surfaces in contact between the base plate 33 of the power module 30 and the heat sink 40 are both planes, and the heat dissipation surface of the base plate 33 and the surface of the heat sink 40 are connected by an interface thermal conductive material layer 50. Typically, the interface thermal conductive material layer 50 may be thermal conductive silicone grease, which has a low thermal conductivity (only 1.2W / (m×K)) and a thicker thickness. This results in a high interface thermal resistance between the heat dissipation surface of the base plate 33 of the power module 30 and the surface of the heat sink 40, which seriously affects the heat dissipation efficiency of the power module 30, thereby becoming an important factor restricting the improvement of the power density of the power module 30.

[0041] In view of this, the power module provided by the embodiment of the present invention increases the contact area between the base plate and the heat sink to improve the heat conduction efficiency between the base plate and the heat sink, thereby improving the heat dissipation performance of the power module, providing the possibility of further improving the power density of the power module, and thus facilitating the improvement of the power density of the power conversion device. To facilitate understanding of the solution provided by the utility model, it is described in detail below with reference to specific embodiments.

[0042] Figure 4 A schematic diagram of the structure of the power module provided by the embodiment of the utility model. Figure 4As shown, the power module 30 may include a substrate 31, a chip 32, and a bottom plate 33. The present invention does not limit the number of chips 32 in the power module 30, and it may be one or more chips 32, which are mounted on one side surface of the substrate 31. The chip 32 may include an integrated circuit (IC) chip, an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or a power transistor.

[0043] In the present invention, the substrate 31 may include a ceramic substrate 311 and a metal layer, and the metal layer is fixed to the surface of the ceramic substrate 311. For example, Figure 5 As shown, Figure 5 for Figure 4 An enlarged view of the local structure at A of the structure shown in . The substrate 31 may include two metal layers, and the two metal layers are respectively fixed to the opposite side surfaces of the ceramic substrate 311. For ease of explanation, the two metal layers are respectively referred to as the first metal layer 312 and the second metal layer 313 in this embodiment. Among them, the first metal layer 312 can be used to mount the chip 32, and the chip 32 can be electrically connected to the first metal layer 312 through a bonding wire 60 such as aluminum, copper, silver and its alloys, or a clip welding process based on metals such as aluminum, copper, silver and its alloys can be used to achieve electrical connection with the first metal layer 312, or other possible methods can be used to achieve electrical connection between the chip 32 and the first metal layer 312, which are not listed here one by one.

[0044] In addition, the first metal layer 312 can also be used to install inductors, resistors or capacitors ( Figure 5 The chip 32 and these electrical devices may be fixed to the surface of the first metal layer 312 by processes such as reflow soldering, or the chip 32 and these devices may be formed into a pre-package using a ball grid array package (BGA), a quad flat non-leaded package (QFN), a small out-line package (SOP), a transistor outline package (TO) or any other packaging form and then fixed to the surface of the first metal layer 312.

[0045] In one embodiment, the ceramic substrate 311 can be made of relatively low-cost materials such as aluminum oxide or aluminum nitride to reduce the overall cost of the power module 30. The first metal layer 312 and the second metal layer 313 can be copper layers respectively, and the substrate 31 is a copper-clad ceramic substrate (direct bonding copper, DBC). In some other embodiments, the first metal layer 312 and the second metal layer 313 can also be aluminum layers respectively, and the substrate 31 is an aluminum-clad ceramic substrate (direct bonded aluminum, DBA). In some other possible embodiments of the present invention, the substrate 31 can also be an active metal brazing copper-clad substrate (active metal bonding, AMB), an insulated metal substrate (insulated metal substrate, IMS) or a printed circuit board (printed circuit board, PCB) and other forms of substrates, which are not limited here.

[0046] You can continue to refer to Figure 5 The first metal layer 312 of the substrate 31 is fixed to the side of the ceramic substrate 311 facing away from the bottom plate 33, and the chip 32 is located on the side of the substrate 31 facing away from the bottom plate 33. In addition, the second metal layer 313 is fixed to the side of the ceramic substrate 311 facing the bottom plate 33, and the second metal layer 313 is located between the ceramic substrate 311 and the bottom plate 33. The second metal layer 313 and the bottom plate 33 can be fixedly connected by welding, sintering, or bonding, thereby achieving thermal contact between the substrate 31 and the bottom plate 33.

[0047] It is worth mentioning that the power module 30 may include one substrate 31 or multiple substrates 31. When it includes multiple substrates 31, the multiple substrates 31 are arranged in a similar manner, so they are not described in detail.

[0048] In the embodiments of the present invention, reference is made to Figure 4 and Figure 5 The bottom plate 33 includes a first surface 331 and a second surface 332 disposed opposite to each other, wherein the substrate 31 is fixed to the first surface 331 of the bottom plate 33. The heat generated by the chip 32 during operation can be transferred through the substrate 31 to the first surface 331 of the bottom plate 33, and then transferred to the second surface 332 of the bottom plate 33. The heat is then dissipated to the outside through the bottom plate 33, thereby achieving heat dissipation for the chip 32.

[0049] You can continue to refer to Figure 4In the present invention, the projection of the substrate 31 on the surface of the bottom plate 33 is located within the contour of the bottom plate 33. Alternatively, the edge of the bottom plate 33 extends beyond the edge of the substrate 31. This helps increase the heat dissipation area of the substrate 31, thereby improving the heat dissipation performance of the power module 30. It is understood that the bottom plate 33 can be made of a metal material with good thermal conductivity. For example, the bottom plate 33 can be a copper substrate or an aluminum substrate.

[0050] In addition, if Figure 4 As shown, the heat sink 40 is located on the side of the second surface 332 of the base plate 33 away from the first surface 331, and the heat sink 40 is in contact with the base plate 33. The heat transferred from the substrate 31 to the base plate 33 can be further transferred to the heat sink 40 through the base plate 33, so that the heat sink 40 can dissipate heat for devices such as the chip 32 in the power module 30.

[0051] It is worth mentioning that in the present invention, the surface area of the first surface 331 of the bottom plate 33 is smaller than the surface area of the second surface 332, and smaller than the surface area of the surface of the heat sink 40 facing the bottom plate 33. This improves the efficiency of heat transfer from the first surface 331 to the second surface 332 of the bottom plate 33 and increases the contact area between the bottom plate 33 and the heat sink 40, thereby improving the efficiency of heat transfer from the substrate 31 from the bottom plate 33 to the heat sink 40, thereby improving the heat dissipation efficiency of the entire power module 30.

[0052] In the power module 30 provided in this embodiment of the present invention, the second surface 332 of the base plate 33 includes a first engaging portion 333, and the surface of the heat sink 40 facing the base plate 33 includes a second engaging portion 41. The first engaging portion 333 is plugged into the second engaging portion 41, and the surface of the first engaging portion 333 abuts against the surface of the second engaging portion 41.

[0053] The present invention does not limit the specific configuration of the first meshing portion 333 and the second meshing portion 41. For example, one of the first meshing portion 333 and the second meshing portion 41 can be a protrusion, and the other of the first meshing portion 333 and the second meshing portion 41 can be a groove. Figure 4 In the illustrated embodiment, the first engaging portion 333 is a protrusion, and the second engaging portion 41 is a groove. The protrusion is inserted into the groove, and the outer surface of the protrusion abuts against the inner surface of the groove.

[0054] The utility model does not limit the number of the first meshing portion 333 and the second meshing portion 41, and can continue to refer to Figure 4The second surface 332 of the bottom plate 33 may include one or more first engaging portions 333, and the heat sink 40 may include one or more second engaging portions 41. In one embodiment of the present invention, the number of first engaging portions 333 and the number of second engaging portions 41 may be the same. This allows the first engaging portions 333 and the second engaging portions 41 to be plugged into and arranged in a one-to-one correspondence, with the surfaces of the corresponding first engaging portions 333 abutting against the surfaces of the second engaging portions 41.

[0055] It can be understood that, compared with the solution in the prior art in which the base plate 33 and the radiator 40 are in contact through a plane, the design solution of the power module 30 provided by the present invention is to increase the contact area between the base plate 33 and the radiator 40 by setting a first engaging portion 333 and a second engaging portion 41 that are plugged in and abut against each other on the contact surface of the base plate 33 and the radiator 40, thereby helping to reduce the interface thermal resistance between the base plate 33 and the radiator 40, so as to improve the heat conduction efficiency from the base plate 33 to the radiator 40, and further help to improve the heat dissipation efficiency of the power module 30.

[0056] In practical applications, the first meshing portion 333 and the second meshing portion 41 may be arranged in various forms. Next, taking the first meshing portion 333 as a protrusion and the second meshing portion 41 as a groove as an example, some possible arrangements of the first meshing portion 333 and the second meshing portion 41 are described.

[0057] Figure 6a A schematic diagram of the structure of the bottom plate provided in the embodiment of the utility model. Figure 6a In the illustrated embodiment, the first engaging portion 333 is a dot-shaped protrusion, and the first engaging portion 333 is a prism-shaped protrusion. It is understood that the second engaging portion 41 is a groove that matches the shape of the first engaging portion 333, so that the first engaging portion 333 and the second engaging portion 41 can be mated and plugged together, and a sufficiently large contact area can be provided between the first engaging portion 333 and the second engaging portion 41.

[0058] like Figure 6a As shown, the second surface 332 of the base plate 33 includes a plurality of first meshing portions 333 arranged in an array. Similarly, the heat sink 40 may also include a plurality of second meshing portions 41, which may also be arranged in an array. This facilitates providing a greater number of first meshing portions 333 on the base plate 33 and a greater number of second meshing portions 41 on the heat sink 40, thereby increasing the contact area between the base plate 33 and the heat sink 40, thereby facilitating improved heat conduction efficiency between the power module 30 and the heat sink 40, thereby improving the heat dissipation efficiency of the power module 30.

[0059] Figure 6b Another structural diagram of the bottom plate provided in the embodiment of the utility model. Figure 6b In the embodiment shown, the first engaging portion 333 is configured as a pyramidal protrusion. Figure 6c In the embodiment shown, the first engaging portion 333 may also be configured as a prismatic protrusion, for example Figure 6c The quadrangular prism shown in FIG. 3 , and in other embodiments, the first engaging portion 333 may also be a triangular prism, a pentagonal prism, etc.

[0060] In addition, when the first engaging portion 333 is configured as a dot-shaped protrusion, it can also be Figure 7a The truncated cone-shaped protrusion shown in Figure 7b The conical protrusion shown in Figure 7c The cylindrical protrusion shown in Figure 7d The hemispherical protrusions shown in .

[0061] In the embodiment of the present invention, the first engaging portion 333 can be set as the above-mentioned dot-shaped protrusions, and can also be set as other possible forms. For example, it can also be set as a strip-shaped protrusion. Figure 8a , Figure 8a Another structural diagram of the bottom plate provided in the embodiment of the utility model. Figure 8a In the embodiment, the cross-section of the first engaging portion 333 is a trapezoid. Furthermore, the base plate 33 may include a plurality of first engaging portions 333 arranged side by side. This facilitates providing a greater number of first engaging portions 333 on the base plate 33, thereby increasing the contact area between the base plate 33 and the heat sink 40, thereby facilitating improved heat conduction efficiency between the power module 30 and the heat sink 40, and thereby improving the heat dissipation efficiency of the power module 30.

[0062] Figure 8b Another structural diagram of the bottom plate provided in the embodiment of the utility model. Figure 8b In the embodiment, the first engaging portion 333 is also a strip-shaped protrusion, but the cross-sectional shape of the first engaging portion 333 is a triangle. In other embodiments of the present invention, the cross-sectional shape of the first engaging portion 333 can also be set as follows Figure 8c the rectangle shown in , or Figure 8d The semicircle shown in the figure, or other regular or irregular shapes, which are not listed here one by one, but should be understood to fall within the scope of protection of the present utility model.

[0063] It can be understood that when the first meshing portion 333 is set as a strip-shaped protrusion, the second meshing portion 41 is a strip-shaped groove that matches the shape of the first meshing portion 333, so as to achieve matching insertion of the first meshing portion 333 and the second meshing portion 41, and to ensure a sufficiently large contact area between the first meshing portion 333 and the second meshing portion 41.

[0064] In addition, the above embodiments are merely illustrative of some possible configurations of the first meshing portion 333 and the second meshing portion 41. On this basis, the shape and quantity of the first meshing portion 333 and the second meshing portion 41 can also be designed according to specific usage requirements. They are not listed one by one here, but they should all be understood to fall within the scope of protection of the present utility model.

[0065] In the present invention, there is no limitation on the molding method of the first meshing portion 333 and the second meshing portion 41. In one possible embodiment, the first meshing portion 333 and the bottom plate 33 are integrally molded, and the molding method can be machining or stamping to simplify the molding process of the power module 30.

[0066] In addition, the second engaging portion 41 and the heat sink 40 may also be an integrally formed structure, and the forming method thereof may be, but is not limited to, machining or stamping, so as to simplify the forming process of the heat sink 40 .

[0067] In other possible embodiments of the present invention, the protruding engagement portion may be an independent structure. For example, if the first engagement portion 333 is a protrusion, the first engagement portion 333 may be connected to the second surface 332 of the base plate 33 to achieve assembly of the first engagement portion 333 and the base plate 33. The connection method may include, but is not limited to, welding methods such as reflow soldering, laser welding, or brazing, or bonding, snap-fitting, riveting, or threaded connection.

[0068] Of course, if the second engaging portion 41 is a protrusion, it can also be assembled with the radiator 40 by connecting with the surface of the radiator 40. The specific connection method can also be but not limited to welding methods such as reflow soldering, laser welding or brazing, or bonding, snap connection, riveting, threaded connection and the like.

[0069] Considering that the bottom plate 33 of the power module 30 is usually made of a metal plate with good thermal conductivity such as copper or aluminum, and the heat sink 40 is usually also made of a metal plate with good thermal conductivity such as copper or aluminum. In order to improve the reliability of heat conduction between the bottom plate 33 and the heat sink 40, in the present invention, the power module 30 also includes an interface thermal conductive material layer 50. Figure 4 The interface thermal conductive material layer 50 is located between the base plate 33 and the heat sink 40, and the interface thermal conductive material layer 50 covers the second surface 332 of the base plate 33, the surface of the first meshing portion 333, the surface of the second meshing portion 41 and the surface of the heat sink 40, so that the base plate 33 and the heat sink 40 are indirectly in contact through the interface thermal conductive material layer 50.

[0070] The present invention does not limit the specific type of the interface thermal conductive material layer 50, which can be exemplified by thermal conductive silica gel, thermal conductive pad, phase change thermal conductive film, etc.

[0071] In addition, the base plate 33 and the heat sink 40 can also be fixedly connected by welding, threaded connection or sintering, so that the base plate 33 and the heat sink 40 exert an extrusion force on the interface thermal conductive material layer 50, thereby improving the reliability of the contact between the base plate 33 and the heat sink 40 through the interface thermal conductive material layer 50.

[0072] It is understood that in the power module 30 provided by the present invention, the first engaging portion 333 and the second engaging portion 41 are provided between the base plate 33 of the power module 30 and the heat sink 40, which facilitates increasing the contact area between the base plate 33 and the heat sink 40. On this basis, a thinner interface thermal conductive material layer 50 is used to ensure reliable heat conduction between the base plate 33 and the heat sink 40. This effectively improves the thermal conductivity of the interface thermal conductive material layer 50, thereby facilitating a reduction in thermal resistance between the base plate 33 and the heat sink 40, thereby improving the heat dissipation effect of the power module 30 and further providing a possibility for increasing the power density of the power module 30.

[0073] It is worth mentioning that the contact surface of the first meshing portion 333 and the second meshing portion 41 may include an inclined surface. For example, the first meshing portion 333 adopts the above Figure 4 In the illustrated arrangement, the first engaging portion 333 includes a first contact surface 3331, the angle between the first contact surface 3331 and the second surface 332 of the base plate 33 comprising an obtuse angle; and the second engaging portion 41 includes a second contact surface 411, the angle between the second contact surface 411 and the surface of the heat sink 40 comprising an obtuse angle. Thus, when the base plate 33 is connected to the heat sink 40, the interface pressure generated by the abutment between the first contact surface 3331 and the second contact surface 411 is relatively high. This interface pressure can increase the thermal conductivity of the interface thermal conductive material layer 50 covering the inclined surface. Furthermore, this interface pressure can also reduce the thickness of the interface thermal conductive material layer 50, effectively reducing the thermal resistance between the base plate 33 and the heat sink 40, thereby improving the heat dissipation of the power module 30.

[0074] In the present invention, the radiator 40 can be a liquid-cooled radiator or an air-cooled radiator. A liquid-cooled radiator uses the flow of a liquid working medium to perform heat exchange, and thus has a higher heat dissipation efficiency. An air-cooled radiator uses the flow of air to perform heat exchange. It is understood that an air-cooled radiator typically includes a fan to increase the air flow rate, thereby improving the heat dissipation effect.

[0075] It is worth mentioning that the surface of the radiator 40 mentioned in the embodiment of the present invention should be understood as the surface of the heat dissipation substrate of the radiator, wherein the heat dissipation substrate can be used for heat exchange with a heat dissipation medium (such as a liquid medium or air).

[0076] In the above Figure 4 In the embodiment shown, the power module 30 is packaged using a housing package. In addition to the above structure, the power module 30 may further include a housing 34, a filling glue 35 (such as silicone gel or epoxy potting glue) and other packaging bodies and a plurality of pins 36, wherein the housing 34 is fixedly connected to the bottom plate 33, and the housing 34 can form a cavity with the side of the bottom plate 33 that carries the substrate 31, and the cavity is used to accommodate the substrate 31, the chip 32, the inductor, the resistor or the capacitor ( Figure 4 The filling glue 35 is filled in the cavity to wrap the substrate 31, the chip 32, the inductor, the resistor or the capacitor, etc. and at least a portion of each pin 36.

[0077] In this embodiment, one end of the plurality of pins 36 is fixedly connected to the surface of the substrate 31 on the side facing away from the bottom plate 33, for example, it can be fixedly connected to the first metal layer 312 of the substrate 31. In one implementation, the first metal layer 312 includes a plurality of solder pads, and one end of each pin 36 is respectively soldered to a corresponding solder pad using solder paste or other solder, or bonded using an adhesive such as nano silver glue, or sintered using a material such as silver or copper, so that each pin 36 is fixed to the first metal layer 312 and electrically connected to the first metal layer 312. The housing 34 includes a plurality of through holes that connect the interior of the cavity with the outside, and the other ends of the plurality of pins 36 are respectively exposed to the outside of the cavity through the plurality of through holes, so that each pin 36 can be electrically connected to an external device, thereby achieving electrical connection between the power module 30 and the external device. Here, the external device can be a circuit board of a power conversion device used by the power module 30.

[0078] For example, Figure 4 As shown, the aforementioned multiple through-holes can be respectively provided on a side wall of the housing 34 opposite the base plate 33. As will be readily understood, the outer surface of this side wall can be considered the top surface of the power module 30. Therefore, in this embodiment, each pin 36 is exposed on the top surface of the power module, enabling the power module 30 to interconnect externally on this top surface. Since the top surface area of the power module 30 is relatively large, sufficient layout space is provided for the pins 36, and it is also feasible to provide the power module 30 with more pins 36, thereby improving the flow capacity of the power module 30.

[0079] Of course, the aforementioned multiple through holes can also be provided on one or more side walls of the housing 34 for connection to the base plate 33. In this case, the pins 36 of the power module 30 can be led out from the side of the housing. Alternatively, in other embodiments, the multiple through holes can be partially provided on a side wall of the housing 34 opposite the base plate 33, while the other partially provided on one or more side walls of the housing 34 for connection to the base plate 33. In this case, the pins of the power module 30 can be connected to the outside by leading out from the top surface or from the side surface.

[0080] The present invention does not limit the specific configuration form of the pin 36 , which may be a pin, a busbar, or a screw terminal.

[0081] In the power module 30 provided in the embodiment of the present invention, the heat generated by the chip 32 and other devices in the power module 30 can be transferred to the bottom plate 33 through the substrate 31 and then transferred to the heat sink 40. Since the bottom plate 33 and the heat sink 40 include an interlocking and contacting engaging portion, the contact area between the bottom plate 33 and the heat sink 40 can be larger, which is beneficial to improving the thermal conductivity between the bottom plate 33 and the heat sink 40, and provides the possibility of setting more power devices in the power module 30, which is beneficial to improving the power density of the power module 30.

[0082] The design of the power module 30 provided by the present invention is not only applicable to the power module using the housing packaging method mentioned above, but also applicable to power modules of any other packaging form. Figure 9 As shown, Figure 9 Another structural schematic diagram of the power module provided in an embodiment of the present invention. In an embodiment of the present invention, the power module 30 is packaged by molding. The power module 30 may include a packaging body such as a plastic encapsulation material 37, wherein the plastic encapsulation material 37 may be used to wrap at least a portion of the substrate 31, the chip 32, the inductor, the resistor or the capacitor, and each pin 36. It is worth mentioning that the plastic encapsulation material 37 may also wrap at least a portion of the bottom plate 33 to improve the connection strength between the bottom plate 33 and the plastic encapsulation material 37, thereby improving the overall structural strength of the power module 30. In addition, the plastic encapsulation material 37 may expose the second surface 332 of the bottom plate 33 so that heat can be in thermal contact with the heat sink 40 through this side surface of the bottom plate 33.

[0083] Similarly, one end of the plurality of pins 36 is fixedly connected to the surface of the substrate 31 facing away from the bottom plate 33, and the other ends of the plurality of pins 36 are exposed outside the package body 37, so that each pin 36 can be electrically connected to an external device, thereby achieving electrical connection between the power module 30 and the external device. The connection method of each pin 36 to the substrate 31 and the lead-out method of each pin 36 can be referred to the description of the previous embodiment and will not be repeated here.

[0084] In some embodiments, reference may be made to Figure 9The power module 30 may further include a cover plate 38, which may be disposed on the side of the chip 32 and other electrical components facing away from the substrate 31. The surface of the cover plate 38 facing away from the substrate 31 is exposed to the outside of the molding compound 37. The cover plate 38 includes a plurality of openings. The ends of the plurality of pins 36, which are away from the substrate 31, extend through the openings to the side of the cover plate 38 facing away from the substrate 31. Each pin 36 is relatively fixed to the corresponding opening through an interference fit, so that the cover plate 38 limits the position of each pin 36, thereby improving the structural reliability of each pin 36.

[0085] From the above description of power modules 30 using different packaging formats and including a base plate 33, it can be understood that since the packaging of the power module 30 is generally implemented on the side thereof facing away from the base plate 33, and the surface of the base plate 33 facing the heat sink 40 is exposed outside the packaging structure, the heat dissipation solution provided by the present invention is applicable to power modules 30 of any packaging format and is relatively easy to implement.

[0086] In addition, although the heat dissipation solution of the power module 30 is introduced by taking the inverter as an example in the above embodiments of the present invention, it can be understood that the heat dissipation solution provided by the present invention is still applicable to other power conversion devices provided with a power module 30 including a base plate 33. Since its implementation method is similar to that in the above-mentioned inverter, it will not be described in detail here, but it should be understood that it falls within the scope of protection of the present invention.

[0087] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A power module with enhanced heat dissipation, characterized in that: The power module includes a base plate, a substrate, a chip and a heat sink, wherein: The bottom plate includes a first surface and a second surface disposed opposite to each other, the substrate is fixed to the first surface, the chip is located on a side of the substrate facing away from the bottom plate, and the chip is electrically connected to the substrate; The heat sink is located on the side of the second surface facing away from the first surface; the surface area of the first surface is smaller than the surface area of the second surface, and smaller than the surface area of the side of the heat sink facing the bottom plate.

2. The power module according to claim 1, wherein: The second surface includes a first engaging portion; the surface of the heat sink facing the bottom plate includes a second engaging portion; the second engaging portion is plugged into the first engaging portion, and a surface of the second engaging portion abuts against a surface of the first engaging portion.

3. The power module according to claim 2, wherein: One of the first engaging portion and the second engaging portion is a protrusion, and the other of the first engaging portion and the second engaging portion is a groove.

4. The power module according to claim 3, wherein: The protrusions are point-shaped protrusions, the second surface of the base plate includes a plurality of first engaging portions, the heat sink includes a plurality of second engaging portions, and the plurality of first engaging portions and the plurality of second engaging portions are plug-connected in a one-to-one correspondence.

5. The power module according to claim 4, wherein: A plurality of the first engaging portions are arranged in an array, and a plurality of the second engaging portions are arranged in an array.

6. The power module according to claim 4 or 5, characterized in that: The protrusions are prism-shaped protrusions, pyramid-shaped protrusions, prism-shaped protrusions, frustum-shaped protrusions, cone-shaped protrusions, cylindrical protrusions or hemispherical protrusions.

7. The power module according to claim 3, wherein: The protrusion is a strip-shaped protrusion, the second surface of the bottom plate includes a plurality of first engaging portions, the heat sink includes a plurality of second engaging portions, and the plurality of first engaging portions and the plurality of second engaging portions are plug-connected in a one-to-one correspondence.

8. The power module according to claim 7, wherein: A plurality of the first engaging portions are arranged side by side, and a plurality of the second engaging portions are arranged side by side.

9. The power module according to claim 7 or 8, wherein: The cross-sectional shape of the protrusion is trapezoidal, triangular, rectangular or semicircular.

10. The power module according to any one of claims 2 to 5, wherein: The power module further includes an interface thermal conductive material layer, which covers the second surface of the base plate, the surface of the first engaging portion, the surface of the heat sink facing the base plate, and the surface of the second engaging portion.

11. The power module according to claim 10, wherein: The first engaging portion includes a first contact surface, and the angle between the first contact surface and the second surface includes an obtuse angle; the second engaging portion includes a second contact surface, and the angle between the second contact surface and the surface of the heat sink facing the base plate includes an obtuse angle; the first contact surface and the second contact surface are abutted through the interface thermal conductive material layer.

12. The power module according to any one of claims 1 to 5, characterized in that: The power module further includes a package body, which encapsulates the substrate and the chip.

13. A power conversion device, characterized in that: The invention comprises a circuit board and the power module according to any one of claims 1 to 12, wherein the power module is electrically connected to the circuit board.

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