Power module packaging structure

Abstract

The embodiment of the utility model discloses a power module packaging structure which comprises a substrate and a power unit. Wherein the power unit comprises a first metal structure, a power device and a second metal structure which are sequentially overlapped, the second metal structure comprises a copper layer, the power unit is electrically connected with the substrate through the first metal structure, and the power unit is electrically connected with an external circuit board through the copper layer of the second metal structure. Therefore, the stray inductance of the power unit can be reduced, and the heat capacity of the power unit can be increased.

Description

Technical Field

[0001] This utility model relates to power module packaging technology, and more particularly to a power module packaging structure. Background Technology

[0002] Power modules are trending towards miniaturization and integration, and their merging with circuit boards is becoming a future trend. When designing power module packages, it is essential to minimize the stray inductance of the power units. Therefore, there is a pressing need to provide a power module package structure that reduces the stray inductance of the power units. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a power module packaging structure that reduces the noise of the power unit by setting a first metal structure and a second metal structure in conjunction with the substrate.

[0004] This utility model provides a power module packaging structure, which includes: a substrate; and a power unit. The power unit includes a first metal structure, a power device, and a second metal structure stacked sequentially. The second metal structure includes a copper layer. The power unit is electrically connected to the substrate through the first metal structure and to an external circuit board through the copper layer of the second metal structure.

[0005] In some embodiments, the thickness of the first metal structure is greater than or equal to 3 micrometers.

[0006] In some embodiments, the first metal structure includes a first metal layer electrically connected to the substrate.

[0007] In some embodiments, the first metal layer is a silver layer.

[0008] In some embodiments, the first metal layer is a gold-tin alloy layer.

[0009] In some embodiments, the first metal layer is a gold layer and a tin layer.

[0010] In some embodiments, the first metal layer is a multilayer structure, wherein the multilayer structure is an alternating structure of gold and tin layers.

[0011] In some embodiments, the thickness of the first metal layer is greater than or equal to 2 micrometers.

[0012] In some embodiments, the first metal structure further includes a first welding layer and a second metal layer, the first welding layer connecting the first metal layer and the second metal layer, and the second metal layer being electrically connected to the substrate.

[0013] In some embodiments, the first solder layer is a silver solder layer or a gold-tin solder layer.

[0014] In some embodiments, the second metal layer is a silver layer.

[0015] In some embodiments, the second metal structure includes a third metal layer that electrically connects the power device and the external circuit board.

[0016] In some embodiments, the third metal layer is the copper layer.

[0017] In some embodiments, the second metal structure sequentially includes a third metal layer, a second welding layer, and a fourth metal layer, wherein the second welding layer connects the fourth metal layer and the third metal layer, and one side of the fourth metal layer is connected to the power device.

[0018] In some embodiments, the third metal layer is the copper layer, and the fourth metal layer is the gold layer or the silver layer.

[0019] In some embodiments, the second welding layer is a silver welding layer or a copper welding layer.

[0020] In some embodiments, the side of the substrate facing the power unit is provided with a first positioning mark.

[0021] In some embodiments, the second metal structure of the power unit is provided with a second positioning mark.

[0022] In some embodiments, the side protrusions of the substrate are formed with clamping portions.

[0023] In some embodiments, the side recesses of the substrate are formed with clamping grooves.

[0024] In some embodiments, the substrate is provided with a receiving groove that accommodates the power unit, and there is a certain distance between the sidewall of the receiving groove and the power unit.

[0025] In some implementations, the power devices are IGBTs and FRDs.

[0026] In some implementations, the power device is one of a MOSFET, a SiC IGBT, or an RC-IGBT.

[0027] In some embodiments, the substrate is a copper substrate or a copper-clad substrate.

[0028] This utility model provides a power module packaging structure, including a substrate and a power unit. The power unit comprises a first metal structure, a power device, and a second metal structure stacked sequentially. The second metal structure includes a copper layer. The power unit is electrically connected to the substrate through the first metal structure and to an external circuit board through the copper layer of the second metal structure. This reduces the inductance of the power unit and increases its heat capacity. Attached Figure Description

[0029] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

[0030] Figure 1 This is a schematic diagram of the first power module packaging structure provided in this embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the second power module packaging structure provided in this embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the third power module packaging structure provided in this embodiment of the present utility model;

[0033] Figure 4 This is a schematic diagram of the positioning mark provided in an embodiment of the present utility model;

[0034] Figure 5 This is a schematic diagram of the clamping part provided in an embodiment of the present utility model;

[0035] Figure 6 This is a schematic diagram of a clamping groove provided in an embodiment of the present utility model;

[0036] Figure 7 This is a schematic diagram of another clamping groove provided in an embodiment of the present utility model.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1-Substrate; 11-Clamping part; 12a, 12b-Clamping groove; 13-Receiving groove; 2-Power unit; 21-First metal structure; 211-First metal layer; 212-First solder layer; 213-Second metal layer; 22-Power device; 23-Second metal structure; 231-Third metal layer; 232-Second solder layer; 233-Fourth metal layer; 5a-First positioning mark; 5b-Second positioning mark. Detailed Implementation

[0039] The present application is described below based on embodiments, but it is not limited to these embodiments. In the detailed description of the present application below, certain specific details are described in detail. Those skilled in the art can fully understand the present application without these details. To avoid obscuring the substance of the present application, well-known methods, processes, flows, elements, and circuits are not described in detail.

[0040] Furthermore, those skilled in the art should understand that the accompanying drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0041] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] For ease of explanation, spatially related terms such as “inside,” “outside,” “below,” “below,” “lower,” “above,” “upper,” etc., are used herein to describe the relationship between one element or feature illustrated in the figure and another. It will be understood that spatially related terms may be intended to encompass different orientations of the device in use or operation besides those depicted in the figure. For example, if the device in the figure is flipped, an element described as “below” or “below” another element or feature would then be positioned “above” that other element or feature. Thus, the exemplified term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially related descriptive terms used herein should be interpreted accordingly.

[0043] Unless the context explicitly requires it, words such as "including" or "contains" throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to".

[0044] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0045] Figure 1 This is a schematic diagram of the first power module packaging structure provided in this embodiment of the present invention, as shown below. Figure 1As shown, the power module packaging structure includes a substrate 1 and a power unit 2. It should be noted that the substrate 1 is a copper substrate or a copper-clad substrate. Further, the power unit 2 includes a first metal structure 21, a power device 22, and a second metal structure 23 stacked sequentially. The power unit 2 is electrically connected to the substrate 1 through the first metal structure 21, and the thickness of the first metal structure 21 is greater than or equal to 3 micrometers. It should also be noted that the second metal structure 23 includes a copper layer, and the power unit 2 is electrically connected to an external circuit board (not shown in the figure) through the copper layer of the second metal structure 23. Thus, the power unit 2 is electrically connected to the external circuit board through the substrate 1 and the second metal structure 23, reducing the inductance of the power unit 2 and increasing its heat capacity.

[0046] like Figure 1 As shown, in one embodiment, the first metal structure 21 includes a first metal layer 211. It should be noted that the first metal layer 211 is electrically connected to the substrate 1. Optionally, the first metal layer 211 is a silver layer. Optionally, the first metal layer 211 is a gold-tin alloy layer, which has a low melting point and is easy to solder. Optionally, the first metal layer 211 is a combination of a gold layer and a tin layer. Optionally, the first metal layer 211 has a multilayer structure with alternating gold and tin layers. This multilayer structure is easier to process than a gold-tin alloy layer, resulting in better connection performance between the power unit 2 and the substrate 1, improved power cycle reliability, and resistance to thermal shock. Furthermore, the thickness of the first metal layer 211 is greater than or equal to 2 micrometers, thereby increasing the solder thickness to enhance solder strength and prevent breakage during soldering.

[0047] Figure 2 This is a schematic diagram of the second power module packaging structure provided in this embodiment of the present invention, as shown below. Figure 2 As shown, in one embodiment, the first metal structure 21 includes a first metal layer 211, a first solder layer 212, and a second metal layer 213. Further, the first solder layer 212 connects the first metal layer 211 and the second metal layer 213, and the second metal layer 213 is electrically connected to the substrate 1. It should be noted that the first solder layer 212 is a silver solder layer or a gold-tin solder layer. It should also be noted that the second metal layer 213 is a silver layer.

[0048] Combination Figure 1 and Figure 2 As shown, in one embodiment, the second metal structure 23 includes a third metal layer 231, and the third metal layer 231 is electrically connected to the power device 22 and the external circuit board. Further, the third metal layer 231 is a copper layer.

[0049] Figure 3 This is a schematic diagram of the third power module packaging structure provided in this embodiment of the present invention, as shown below. Figure 3As shown, in one embodiment, the second metal structure 23 sequentially includes a third metal layer 231, a second solder layer 232, and a fourth metal layer 233. Specifically, the second solder layer 232 connects the fourth metal layer 233 and the third metal layer 231, while one side of the fourth metal layer 233 is connected to the power device 22. Optionally, the third metal layer 231 is a copper layer, and the fourth metal layer 233 is a gold or silver layer to reduce the stress on the second solder layer 232. Optionally, the second solder layer 232 is a silver solder layer or a copper solder layer.

[0050] Figure 4 This is a schematic diagram of the positioning mark provided in an embodiment of the present utility model, as shown below. Figure 4 As shown, in one embodiment, the side of the substrate 1 facing the power unit 2 is provided with a first positioning mark 5a. It should be noted that the first positioning mark 5a is used for precise positioning when the power module is electrically connected to an external circuit board.

[0051] like Figure 4 As shown, in one embodiment, the second metal structure 23 of the power unit 2 is provided with a second positioning mark 5b. It should be noted that the second positioning mark 5b is used to identify the orientation of the power unit 2, and is also used for precise positioning when the power module is electrically connected to an external circuit board.

[0052] Figure 5 This is a schematic diagram of the clamping part provided in an embodiment of the present invention, as shown below. Figure 6 As shown, in one embodiment, a clamping portion 11 is formed on the side protrusion of the substrate 1, and the cross-section of the clamping portion 11 can be formed as a semi-circle. It should be noted that in automated production, the gripper or hook of a robotic arm can clamp or place the power unit 2 through the clamping portion 11. Therefore, when using a robotic arm for clamping, contact with critical parts of the power unit 2 on the substrate 1 can be avoided, thus ensuring that the power unit 2 is not damaged during the production process, facilitating the subsequent automated production of the power module.

[0053] Figure 6 This is a schematic diagram of a clamping groove provided in an embodiment of the present invention, as shown below. Figure 6 As shown, in one embodiment, a clamping groove 12a is formed in the side recess of the substrate 1. The clamping groove 12a has a rectangular cross-section and is located in the middle of the substrate 1. It should be noted that in automated production, the gripper or hook of the robotic arm can clamp or place the power unit 2 through the clamping groove 12a. Therefore, when using a robotic arm for clamping, contact with critical parts of the power unit 2 on the substrate 1 can be avoided, thereby ensuring that the power unit 2 is not damaged during the production process, which facilitates the subsequent automated production of the power module.

[0054] Figure 7 This is a schematic diagram of another clamping groove provided in an embodiment of the present invention, as shown below. Figure 7 As shown, in one embodiment, a clamping groove 12b is formed in the side recess of the substrate 1. The clamping groove 12b is located at the bottom of the substrate 1 and has a chamfered structure. It should be noted that in automated production, the gripper or hook of the robotic arm can clamp or place the power unit 2 through the clamping groove 12b. Therefore, when using a robotic arm for clamping, contact with critical parts of the power unit 2 on the substrate 1 can be avoided, thereby ensuring that the power unit 2 is not damaged during the production process, which facilitates the subsequent automated production of the power module.

[0055] Combination Figures 5 to 7 As shown, in one embodiment, the substrate 1 is provided with a receiving groove 13. Specifically, the receiving groove 13 is used to receive the power unit 2, that is, the power unit 2 is disposed at the bottom of the receiving groove 13. Further, there is a certain distance between the sidewall of the receiving groove 13 and the power unit 2 to avoid damage to the power unit 2. It should be noted that the receiving groove 13 provided on the substrate 1 can prevent the power device 22 from being subjected to stress impact during subsequent processing, thereby forming a protection for the power device 22.

[0056] Combination Figures 1 to 4 As shown, in one embodiment, the substrate 1 can also be configured as a complete planar structure, while the power unit 2 is directly disposed on the surface of the substrate 1.

[0057] As an optional implementation, the power device 22 is an IGBT (Insulated-Gate Bipolar Transistor) and an FRD (Fast Recovery Diode). Alternatively, the power device 22 is one of a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), a SiC IGBT (Silicon Carbide IGBT), or an RC-IGBT (Reverse Conduction IGBT).

[0058] This utility model provides a power module packaging structure, including a substrate and a power unit. The power unit comprises a first metal structure, a power device, and a second metal structure stacked sequentially. The second metal structure includes a copper layer. The power unit is electrically connected to the substrate through the first metal structure and to an external circuit board through the copper layer of the second metal structure. This reduces the inductance of the power unit and increases its heat capacity.

[0059] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A power module package structure, characterized by, The power module packaging structure comprises: a substrate; and a power unit comprising a first metal structure, a power device and a second metal structure in sequence, the second metal structure comprising a copper layer, the power unit being electrically connected with the substrate through the first metal structure, and the power unit being electrically connected with an external circuit board through the copper layer of the second metal structure.

2. The power module package structure of claim 1, wherein, The first metal structure has a thickness greater than or equal to 3 microns.

3. The power module package structure of claim 1, wherein, The first metal structure comprises a first metal layer, and the first metal layer is electrically connected with the substrate.

4. The power module package structure of claim 3, wherein, The first metal layer is a silver layer.

5. The power module package structure of claim 3, wherein, The first metal layer is a gold-tin alloy layer.

6. The power module package structure of claim 3, wherein, The first metal layer is a gold layer and a tin layer.

7. The power module package structure of claim 3, wherein, The first metal layer is a multilayer structure, and the multilayer structure is an alternating structure of a gold layer and a tin layer.

8. The power module package structure according to any one of claims 3 to 7, characterized in that, The first metal layer has a thickness greater than or equal to 2 microns.

9. The power module package structure of claim 3, wherein, The first metal structure further comprises a first solder layer and a second metal layer, the first solder layer being connected between the first metal layer and the second metal layer, and the second metal layer being electrically connected with the substrate.

10. The power module package structure of claim 9, wherein, The first solder layer is a silver solder layer or a gold-tin solder layer.

11. The power module package structure of claim 9, wherein, The second metal layer is a silver layer.

12. The power module package structure of claim 1, wherein, The second metal structure comprises a third metal layer, and the third metal layer is electrically connected with the power device and the external circuit board.

13. The power module package structure of claim 12, wherein, The third metal layer is the copper layer.

14. The power module package structure of claim 1, wherein, The second metal structure comprises a third metal layer, a second solder layer and a fourth metal layer in sequence, the second solder layer being connected between the fourth metal layer and the third metal layer, and one side of the fourth metal layer being connected with the power device.

15. The power module package structure of claim 14, wherein, The third metal layer is the copper layer, and the fourth metal layer is a gold layer or a silver layer.

16. The power module package structure of claim 15, wherein, The second solder layer is a silver solder layer or a copper solder layer.

17. The power module package structure of claim 1, wherein, One side of the substrate facing the power unit is provided with a first positioning mark.

18. The power module package structure of claim 1, wherein, The second metal structure of the power unit is provided with a second positioning mark.

19. The power module package structure of claim 1, wherein, The side edge of the substrate is protruded to form a clamping portion.

20. The power module package structure of claim 1, wherein, The side edge of the substrate is recessed to form a clamping groove.

21. The power module package structure of claim 1, wherein, The substrate is provided with a receiving groove, the receiving groove accommodating the power unit, and a certain spacing being provided between the side wall of the receiving groove and the power unit.

22. The power module package structure of claim 1, wherein, The power device is an IGBT and an FRD.

23. The power module package structure of claim 1, wherein, The power device is one of a MOS tube, an SICIGBT or an RC-IGBT.

24. The power module package structure of claim 1, wherein, The substrate is a copper substrate or a copper-clad substrate.

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