Power module packaging structure

Abstract

The utility model provides a power module packaging structure. The power module packaging structure comprises a heat dissipation bottom plate; the direct copper-clad ceramic substrate is arranged on the heat dissipation bottom plate; the middle frame is fixedly connected with the heat dissipation bottom plate so that the direct copper-clad ceramic substrate can be connected in the middle frame in a sleeved mode, and the direct copper-clad ceramic substrate leads out a power terminal and a signal terminal to the side away from the heat dissipation bottom plate through the middle frame; and the cover plate is matched with the window area of the middle frame to seal the window area. Through fixed connection of the heat dissipation bottom plate and the middle frame, a packaging frame with a stable structure is provided for the power module, relative displacement of the middle frame and the bottom plate in the vibration process is avoided, and the risk of terminal breakage is reduced.

Description

Technical Field

[0001] The utility model relates to the application field of semiconductor devices, in particular to a power module packaging structure. Background Art

[0002] As the core device in power electronic converters, power modules have been widely used in new energy system inverters, battery management, electric drive systems, frequency converters, etc. Most power modules work under harsh conditions, so the reliability of power module packaging is extremely important.

[0003] When there is vibration in the power module application conditions, the vibration may be transmitted from the power terminal to the substrate inside the power module, causing fracture at the connection between the power terminal and the substrate, resulting in damage to the power module. Utility Model Content

[0004] In view of the above problems existing in the prior art, the utility model proposes a power module packaging structure, which mainly solves the problem that the existing power module has insufficient anti-vibration performance.

[0005] In order to achieve the above-mentioned purpose and other purposes, the technical solution adopted in this application is as follows.

[0006] The present application provides a power module packaging structure, comprising: a heat dissipation base plate; a direct copper-clad ceramic substrate, which is arranged on the heat dissipation base plate; a middle frame, which is fixedly connected to the heat dissipation base plate to sleeve the direct copper-clad ceramic substrate in the middle frame, wherein the direct copper-clad ceramic substrate respectively leads out power terminals and signal terminals to a side away from the heat dissipation base plate through the middle frame; and a cover plate, which cooperates with a window area of ​​the middle frame to close the window area.

[0007] In one embodiment of the present application, a plurality of connection terminals are disposed on the inner wall of the middle frame, and the connection terminals are welded to the direct copper-clad ceramic substrate to lead out the power terminals and the signal terminals.

[0008] In one embodiment of the present application, a plurality of clamping members are provided on the inner wall of the middle frame, and the cover plate is fixed by the clamping members.

[0009] In one embodiment of the present application, the clamping member includes a lower supporting member and an upper clamping member, and the vertical distance between the upper clamping member and the lower supporting member is greater than or equal to the thickness of the edge of the cover plate.

[0010] In one embodiment of the present application, the tops of the lower support members of each of the clamping members are located in the same plane.

[0011] In one embodiment of the present application, the top surface of the upper locking member is an inclined surface.

[0012] In an embodiment of the present application, the signal terminal is perpendicular to a plane of a side of the middle frame facing away from the heat dissipation base plate.

[0013] In one embodiment of the present application, the heat dissipation base plate and the middle frame are fixed by bolts.

[0014] In an embodiment of the present application, the power terminal is embedded in a plane on one side of the middle frame facing away from the heat dissipation base plate.

[0015] In an embodiment of the present application, a plurality of positioning holes are arranged around the middle frame, metal gaskets are arranged in the positioning holes, and the metal gaskets are in contact with the heat dissipation base plate.

[0016] As described above, a power module packaging structure proposed in the present application has the following beneficial effects.

[0017] By fixedly connecting the heat dissipation base plate and the middle frame, a structurally stable packaging frame is provided for the power module, avoiding relative displacement between the middle frame and the base plate during vibration and reducing the risk of terminal breakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is an exploded view of a power module packaging structure in one embodiment of the present application.

[0019] Figure 2 It is a three-dimensional schematic diagram of a power module packaging structure in one embodiment of the present application.

[0020] Figure 3 It is a schematic diagram of the structure after the heat dissipation base plate, the middle frame and the direct copper-clad ceramic substrate are assembled in one embodiment of the present application.

[0021] Description of Figure Numbers:

[0022] 01-heat dissipation base plate; 02-middle frame; 03-cover plate; 04-direct copper-clad ceramic substrate; 021-signal terminal; 022-power terminal; 023-metal gasket; 025-connecting terminal; 026-upper clamping piece; 027-lower support piece. DETAILED DESCRIPTION

[0023] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0024] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0025] See also Figure 1 and Figure 2 , Figure 1 It is an exploded view of a power module packaging structure in one embodiment of the present application. Figure 2 It is a three-dimensional schematic diagram of the power module packaging structure in an embodiment of the present application. The power module packaging structure provided in the embodiment of the present application includes: a cover plate 03, a middle frame 02, a direct copper-clad ceramic substrate 04 and a heat dissipation base plate 01. The direct copper-clad ceramic substrate 04 is arranged on the heat dissipation base plate 01, the middle frame 02 is fixedly connected to the heat dissipation base plate 01, and the direct copper-clad ceramic substrate 04 is sleeved in the middle frame 02, and the power terminal 022 and the signal terminal 021 of the direct copper-clad ceramic substrate 04 are led out to the side away from the heat dissipation base plate 01 through the middle frame 02. The middle frame 02 includes a window area, and the cover plate 03 cooperates with the window area, so that the heat dissipation base plate 01, the middle frame 02 and the cover plate 03 form a closed cavity, and the direct copper-clad ceramic substrate 04 is encapsulated in the closed cavity.

[0026] In one embodiment, the heat dissipation base plate 01 and the middle frame 02 can be locked by screws, and the specific number of screws can be set and adjusted according to actual application requirements, and is not limited here. The heat dissipation base plate 01 can be made of copper plate, and the specific thickness can also be adjusted according to device requirements, and is not limited here.

[0027] In one embodiment, a plurality of connection terminals 025 are provided on the inner wall of the middle frame 02, and the power terminals 022 and the signal terminals 021 are led out through the connection terminals 025 and the direct copper-clad ceramic substrate 04 through welding. According to the positions of the power terminals 022 and the signal terminals 021 on the direct copper-clad ceramic substrate 04, corresponding connection terminals 025 can be provided on the inner wall of the middle frame 02, and the connection terminals 025 penetrate the inner wall of the middle frame 02, and lead out the power terminals 022 and the signal terminals 021 to a side plane of the middle frame 02 away from the heat dissipation base plate 01.

[0028] In one embodiment, the signal terminal 021 may be a strip-shaped structure, and the model terminal portion of the strip-shaped structure extends out of the middle frame 02 and is perpendicular to the plane of the middle frame 02 away from the heat dissipation base plate 01 .

[0029] In one embodiment, the power terminal 022 may adopt a flat structure, and the power terminal 022 with a flat structure is embedded in a plane of a side of the middle frame 02 away from the heat dissipation base plate 01. The power terminal 022 is provided with a screw hole, which can be locked by a screw, so that when it is heated and collided, the stress is released through the screw locking structure to prevent the power terminal 022 from breaking.

[0030] See also Figure 3 , Figure 3 It is a schematic diagram of the structure after the heat dissipation base plate 01, the middle frame 02 and the direct copper-clad ceramic substrate 04 are assembled in one embodiment of the present application. In one embodiment, the inner wall of the middle frame 02 is also provided with a plurality of clamping members, and the cover plate 03 and the middle frame 02 are fixed by the cooperation of the plurality of clamping members. Specifically, the clamping member may include a lower support member 027 and an upper clamping member 026. The lower support member 027 may be a single one, and of course, it may also be provided as multiple as required. The lower support member 027 provides a support plane, which is the top surface of the lower support member 027. The support planes of different clamping members are coplanar, and the upper clamping member 026 cooperates with the lower support member 027 to clamp the cover plate 03. The vertical distance between the upper clamping member 026 and the lower support member 027 should be greater than or equal to the thickness of the edge of the cover plate 03. The height of the support surface should be higher than the height of the connecting terminal 025 to prevent the connecting terminal 025 from being exposed.

[0031] In one embodiment, the top surface of the upper retaining member 026 can be set as an inclined surface, so that the cover plate 03 can be embedded between the upper retaining member 026 and the lower support member 027 along the inclined surface.

[0032] In another embodiment, a step structure may be provided on the inner wall of the middle frame 02, and the cover plate 03 may be attached to the table of the step structure for sealing and fixing. The specific matching structure of the cover plate 03 and the middle frame 02 may also be set and adjusted according to the actual device requirements, and is not limited here.

[0033] In one embodiment, the window area of ​​the middle frame 02 can be set to a rectangular frame, a circular frame or a polygonal frame, which can be set and adjusted according to the shape of the power device body, and is not limited here. Taking a rectangle as an example, the four corners of the middle frame 02 corresponding to the rectangular window are all provided with positioning holes, and a metal gasket 023 is provided in the positioning hole. After the middle frame 02 is fixedly connected to the heat dissipation base plate 01, the metal gasket 023 can be used to contact the heat dissipation base plate 01 to improve the heat dissipation performance. The entire packaging structure can also be fixed to the corresponding device through the positioning hole.

[0034] In one embodiment, the middle layer of the direct copper-clad ceramic substrate 04 is a ceramic layer, which may be made of aluminum oxide or silicon nitride, and the upper and lower layers are copper layers.

[0035] In one embodiment, the middle frame 02 and the cover plate 03 may be made of the same material, exemplarily PBT+30% GF. The specific material may also be adaptively adjusted according to the device use environment, which is not limited here.

[0036] In one embodiment, during the process of making the packaging structure, the heat dissipation base plate 01, the direct copper-clad ceramic substrate and the chip can be welded together by solder paste reflow soldering, and the middle frame 02 and the heat dissipation base plate 01 can be locked by screws and coated with sealant. Since the heat dissipation base plate 01 can contact the radiator to improve the heat dissipation efficiency, in order to ensure good contact between the heat dissipation pad and the radiator, the screw holes on the heat dissipation points can be set to wedge shape. After sealing with sealant, the connection terminal 025 on the inner wall of the middle frame 02 can be welded to the direct copper-clad ceramic substrate by ultrasonic welding process to lead out the power terminal 022 and the signal terminal 021. Finally, the cover plate 03 is covered after injecting silicone gel.

[0037] Based on the above technical solution of the present application, the hot bottom plate and the middle frame 02 can be locked by screws to improve the vibration resistance of the packaging structure, reduce the relative displacement of the middle frame 02 and the bottom plate during vibration, and thus reduce the risk of terminal breakage. When the power module is in a high-temperature working condition, the power terminal 022 will expand due to the increase in temperature, and stress will be generated at the connection between the power terminal 022 and the direct copper-clad ceramic substrate. Compared with the solution of fastening the middle frame 02 and the bottom plate with rivets, the method of locking with screws is more conducive to the release of stress.

[0038] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A power module packaging structure, characterized in that: include: Heat dissipation base plate; A direct copper-clad ceramic substrate, which is arranged on the heat dissipation base plate; A middle frame, which is fixedly connected to the heat dissipation base plate so that the direct copper-clad ceramic substrate is sleeved in the middle frame, wherein the direct copper-clad ceramic substrate leads the power terminal and the signal terminal to a side away from the heat dissipation base plate through the middle frame; A cover plate cooperates with the window area of ​​the middle frame to close the window area.

2. The power module packaging structure according to claim 1, characterized in that: A plurality of connection terminals are arranged on the inner wall of the middle frame, and the connection terminals are welded to the direct copper-clad ceramic substrate to lead out the power terminals and the signal terminals.

3. The power module packaging structure according to claim 1, characterized in that: The inner wall of the middle frame is provided with a plurality of clamping members, and the cover plate is fixed by the clamping members.

4. The power module packaging structure according to claim 3, characterized in that: The clamping member includes a lower supporting member and an upper clamping member, and a vertical distance between the upper clamping member and the lower supporting member is greater than or equal to the thickness of the edge of the cover plate.

5. The power module packaging structure according to claim 4, characterized in that: The tops of the lower supporting members of each clamping member are located in the same plane.

6. The power module packaging structure according to claim 4, characterized in that: The top surface of the upper clamping piece is an inclined surface.

7. The power module packaging structure according to claim 1, characterized in that: The signal terminal is perpendicular to a plane of a side of the middle frame facing away from the heat dissipation base plate.

8. The power module packaging structure according to claim 1, characterized in that: The heat dissipation bottom plate and the middle frame are fixed by bolts.

9. The power module packaging structure according to claim 1, characterized in that: The power terminal is embedded in a plane of a side of the middle frame away from the heat dissipation base plate.

10. The power module packaging structure according to claim 1, characterized in that: A plurality of positioning holes are arranged around the middle frame, metal gaskets are arranged in the positioning holes, and the metal gaskets are in contact with the heat dissipation bottom plate.

Images