A package structure of a power device module

Abstract

The utility model discloses a kind of packaging structure of power device module, comprising: power device module, the power device module is by power device body, elastic terminal and current-carrying heat conductor are encapsulated by plastic package body and integrated module, the upper portion of the plastic package body is provided with connecting column and the upper portion of connecting column is provided with support column, the surface of the support column is provided with PCB board and welding fixed between PCB board and elastic terminal, the bottom of the current-carrying heat conductor is external heat dissipation surface.The utility model is connected by reflow soldering mounting form with PCB, and its pre-pressure with external heat dissipation surface is borne by support column on plastic package piece passing through PCB, and pre-pressure stress of mounting terminal pin is separated from pre-pressure stress of encapsulated plastic column, both simplify process, so that power module and external heat dissipation surface can be separated in assembly process, and also ensure that power module can bear larger pre-pressure and external heat dissipation surface gap is reduced to minimum to ensure heat dissipation capacity.

Description

Technical Field

[0001] This utility model relates to the field of power device module packaging technology, and more specifically to a packaging structure for a power device module. Background Technology

[0002] A power module is a modular solution that integrates various power semiconductor devices (such as IGBTs, MOSFETs, diodes, etc.) and drive circuitry into a single unit, suitable for high-power electronic devices. These modules are specifically designed to handle high-voltage and high-current power control and conversion tasks, such as motor drives, inverters, power systems, electric vehicle drives, and industrial frequency converters. The core function of power modules is to simplify the design and integration process of high-power electronic systems while improving performance and reliability.

[0003] Current power module packaging structures suffer from complex manufacturing processes, the inseparability of the power module from the external heat dissipation surface during assembly, low structural stress resistance, and unreliable heat dissipation performance. Therefore, a new technical solution is needed to address these issues. Utility Model Content

[0004] The purpose of this utility model is to provide a packaging structure for a power device module, which solves the problems of complex process, inseparable power module and external heat dissipation surface during assembly, low pressure resistance and unreliable heat dissipation performance of existing power module packaging structures.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a packaging structure for a power device module, comprising: a power device module, wherein the power device module is an integral module consisting of a power device body, elastic terminals, and a current-carrying heat conductor encapsulated in a plastic encapsulation body; a connecting post is provided on the upper part of the plastic encapsulation body, and a support post is provided on the upper part of the connecting post; a PCB board is provided on the surface of the support post, and the PCB board is welded and fixed to the elastic terminals; the bottom of the current-carrying heat conductor is an external heat dissipation surface, and a base plate is provided on the lower part of the external heat dissipation surface.

[0006] In a preferred embodiment of this utility model, the diameter of the support column is smaller than that of the connecting column.

[0007] In a preferred embodiment of this utility model, the elastic terminal is arranged in a Z-shaped structure at the extended end of the encapsulation.

[0008] In a preferred embodiment of this utility model, the PCB board penetrates the support column and is in contact with the connecting column.

[0009] In a preferred embodiment of this utility model, the top of the power device module is integrally structured with the PCB by reflow soldering.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0011] This invention employs a terminal pin mounting method to connect to the PCB via reflow soldering. The pre-pressure between the power module and the external heat dissipation surface is borne by support pillars on the plastic encapsulation component that passes through the PCB. This separates the pre-pressure force on the mounted terminal pins from the pre-pressure force on the encapsulation plastic pillars, simplifying the process, allowing the power module to be separated from the external heat dissipation surface during assembly, and ensuring that the power module can withstand significant pre-pressure while minimizing the gap between the power module and the external heat dissipation surface to guarantee heat dissipation. The power device module consists of a power wafer, flexible terminals, and a current-carrying heat conductor encapsulated into a single module. The power device module is mounted to the PCB board on its top via flexible terminals. After the chips are welded together, the power device module operates. During operation, the heat generated by the wafer inside the module is conducted to the external heat dissipation surface through the bottom current-carrying heat conductor. When the power device module dissipates heat to the outside, the contact gap between it and the external heat dissipation surface is controlled by the pre-tightening pressure of the high-temperature resistant plastic in the molding compound. The welding alloy surface of the elastic terminal and the PCB board does not bear this pre-tightening pressure. When the PCB board and the power device module are assembled into a whole, during the assembly process of the heat dissipation surface, the elastic deformation of the elastic terminal itself reduces the stress influence of the pressure between the PCB board and its welding alloy surface on the internal terminal welding points of the module, ensuring that the internal terminal welding points of the module are stable and free of cracks. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0013] Figure 2 This is a schematic diagram of the encapsulation structure of this utility model;

[0014] Figure 3 This is a schematic diagram of the exploded structure of the encapsulated body of this utility model;

[0015] Figure 4 This is a side view of the structure of this utility model.

[0016] In the diagram: 1. Molded enclosure; 2. Flexible terminal; 3. External heat dissipation surface; 4. PCB board; 5. Support column; 6. Base plate; 7. Connecting column; 8. Current-carrying heat conductor; 9. Power device body. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Please see Figure 1-4 This utility model provides a technical solution: a packaging structure for a power device module, comprising: a power device module, wherein the power device module is an integral module consisting of a power device body 9, elastic terminals 2, and a current-carrying heat conductor 8 encapsulated in a plastic encapsulation body 1; a connecting post 7 is provided on the upper part of the plastic encapsulation body 1, and a support post 5 is provided on the upper part of the connecting post 7; a PCB board 4 is provided on the surface of the support post 5, and the PCB board 4 is welded and fixed to the elastic terminals 2; the bottom of the current-carrying heat conductor 8 is an external heat dissipation surface 3, and a base plate 6 is provided on the lower part of the external heat dissipation surface 3; the terminal pins are mounted to the PCB via reflow soldering; the pre-pressure of the terminal pins to the external heat dissipation surface 3 is borne by the support post 5 on the plastic encapsulation body passing through the PCB, thus separating the pre-pressure force of the mounted terminal pins from the pre-pressure force of the encapsulation plastic post, which simplifies the process, allows the power module to be separated from the external heat dissipation surface 3 during assembly, and ensures that the power module can withstand the pressure. The power device module is designed to minimize the gap between the power wafer, elastic terminal 2, and current-carrying heat conductor 8 by minimizing the pre-pressure, thus ensuring heat dissipation. The power device module is encapsulated as a single module by a plastic encapsulation body 1. The power device module is then integrated with the PCB board 4 by surface-mount welding of the elastic terminal 2 to the top of the module. The heat generated by the wafer inside the power device module during operation is conducted to the external heat dissipation body 3 through the bottom current-carrying heat conductor 8. When the power device module dissipates heat to the outside, the contact gap between it and the external heat dissipation body 3 is controlled by the pre-tightening pressure of the high-temperature resistant plastic in the plastic encapsulation body 1. The welding alloy surface of the elastic terminal 2 and the PCB board 4 does not bear this pre-tightening pressure. When the PCB board 4 and the power device module are assembled onto the heat dissipation surface, the elastic deformation of the elastic terminal 2 reduces the stress effect of the pressure between the PCB board 4 and its welding alloy surface on the internal terminal welding points of the module, ensuring that the internal terminal welding points of the module are stable and free of cracks.

[0019] Further improvements, such as Figure 2 As shown: the diameter of the support column 5 is smaller than that of the connecting column 7.

[0020] Further improvements, such as Figure 4 As shown: The elastic terminal 2 is arranged in a Z-shaped structure at the extension end of the encapsulation body 1. The elastic terminal 2 with the Z-shaped structure design can undergo elastic deformation when subjected to external force, effectively absorbing and relieving the stress generated during the assembly process, and avoiding the stress from being directly transmitted to the welding point, causing the welding point to crack or fail.

[0021] Further improvements, such as Figure 4As shown: The PCB board 4 passes through the support column 5 and is in contact with the connecting column 7. The PCB board 4 passes through the support column 5 and is in contact with the connecting column 7, which ensures a stable connection between the PCB board 4 and the power device module. At the same time, it is conducive to the rapid conduction of heat from the power device module to the PCB board 4, and then further dissipation through the PCB board 4.

[0022] Further improvements, such as Figure 1 As shown: The top of the power device module is integrally structured with the PCB by reflow soldering. The reflow soldering method achieves a high-precision and high-reliability connection between the power device module and the PCB board 4.

[0023] Working Principle: The power device module consists of a power device body 9, flexible terminals 2, and a current-carrying heat conductor 8, all encapsulated in a plastic package 1. The plastic package 1 not only protects the internal components from external environmental influences, but the flexible terminals 2 are also arranged in a Z-shape at the extension end of the plastic package 1 and are fixed to the PCB board 4 via reflow soldering. This connection method ensures the stability and reliability of the electrical connection, while the Z-shape structure helps absorb stress during assembly. The pre-pressure of the power module against the external heat dissipation surface 3 is borne by support pillars 5 that pass through the plastic package on the PCB. The design of the support pillars 5 separates the pre-pressure stress on the mounting terminal pins from that on the encapsulated plastic pillars, simplifying the process and ensuring the power module can withstand significant pre-pressure. By bearing the pre-pressure through the support pillars 5, the gap between the power module and the external heat dissipation surface 3 is reduced, improving heat dissipation capacity. Simultaneously, the separated pre-pressure design avoids the impact of stress on the solder joints. The heat generated by the wafer inside the power device module during operation is conducted to the external heat dissipation surface 3 through the bottom current-carrying heat conductor 8. The current-carrying heat conductor 8 possesses excellent thermal conductivity, enabling rapid heat transfer from internal components to the external heat dissipation surface 3. This efficient heat conduction mechanism ensures the power device module operates within its normal operating temperature range, improving product reliability and lifespan. During assembly, the PCB board 4 and the power device module are assembled onto the heat dissipation surface. The elastic deformation of the flexible terminal 2 reduces the impact of stress generated during assembly on the internal terminal solder joints of the module. This simplifies the assembly process and improves assembly efficiency. Simultaneously, the design of the flexible terminal 2 ensures the stability and reliability of the module during assembly and use.

[0024] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0025] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can refer to mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc., are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0026] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A packaging structure for a power device module, characterized in that: include: The power device module is a power device body (9), an elastic terminal (2) and a current-carrying heat conductor (8) encapsulated in a plastic encapsulation body (1) as an integrated module. The upper part of the plastic encapsulation body (1) is provided with a connecting post (7) and the upper part of the connecting post (7) is provided with a support post (5). The surface of the support post (5) is provided with a PCB board (4) and the PCB board (4) is welded and fixed to the elastic terminal (2). The bottom of the current-carrying heat conductor (8) is an external heat dissipation surface (3) and the lower part of the external heat dissipation surface (3) is provided with a base plate (6).

2. The packaging structure of a power device module according to claim 1, characterized in that: The diameter of the support column (5) is smaller than that of the connecting column (7).

3. The packaging structure of a power device module according to claim 1, characterized in that: The elastic terminal (2) is arranged in a Z-shaped structure at the extended end of the encapsulation body (1).

4. The packaging structure of a power device module according to claim 1, characterized in that: The PCB board (4) passes through the support column (5) and is in contact with the connecting column (7).

5. The packaging structure of a power device module according to claim 1, characterized in that: The top of the power device module is integrally structured with the PCB board (4) by reflow soldering.

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