Welding positioning tool for power module

Abstract

The application relates to the field of semiconductor packaging and discloses a welding positioning tool for a power module, wherein the silicon carbide welding positioning tool comprises a first positioning member, a first hole group is arranged through the first positioning member in a first direction, the first hole group comprises a first through hole and a second through hole, the first through hole is located on one side of the second through hole, the first through hole corresponds to a gate in a power device, the second through hole corresponds to a welding position in the power device, a second positioning member is arranged through the second positioning member in the first direction, the third through hole is arranged correspondingly with the second through hole, the second positioning member is provided with a covering member on one side of the first positioning member in the first direction, the covering member extends in the first direction, and covers the upper surface of the gate in the power device after passing through the first through hole, so that the gate in the power device and the welding position are isolated. The welding positioning tool for the power module can isolate the gate and the welding position during specific welding.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging, and in particular to welding positioning fixtures for power modules. Background Technology

[0002] Currently, in the packaging of domestic power modules, especially for silicon carbide modules, the bonding wires on the chip surface are generally made of thick aluminum wire. As power modules develop towards higher power density, more and more requirements are put forward for module packaging technology. At present, copper clip welding solution is generally used to replace thick aluminum wire for bonding.

[0003] However, during vacuum reflow of copper clip solder, the molten solder bubbles can cause solder ball splashing. The solder balls can then splash onto the gate of the power device. Moreover, due to the wettability of gold, the solder balls can quickly expand and occupy part of the gate area, directly leading to product scrap. Utility Model Content

[0004] This application primarily addresses the technical problem in existing technologies where solder balls fall onto the gate during soldering, leading to product scrap. It provides a soldering positioning fixture for power modules that isolates the gate from the soldering position during specific soldering operations.

[0005] To address the aforementioned technical problems, this application provides a welding positioning fixture for a power module, characterized in that the welding positioning fixture for the power module is used to achieve welding positioning of power devices in the power module, and the silicon carbide welding positioning fixture includes,

[0006] A first positioning element is disposed on one side of the power module along a first direction. The first positioning element is provided with a first hole group through the first direction. The first hole group includes a first through hole and a second through hole. The first through hole is located on one side of the second through hole. The first through hole corresponds to the gate in the power device, and the second through hole corresponds to the welding position in the power device.

[0007] A first limiting member is connected to a first positioning member, and a limiting cavity is formed between the first limiting member and the first positioning member. The power module is located in the limiting cavity to form a limiting relationship between the power module and the first limiting member along a second direction and a third direction.

[0008] The second positioning member is disposed on the side of the first positioning member along the first direction and away from the power module. The second positioning member is provided with a third through hole along the first direction, and the third through hole is provided corresponding to the second through hole. The second positioning member is provided with a cover member along the first direction and close to the first positioning member. The cover member extends along the first direction and covers the upper surface of the gate in the power device after passing through the first through hole, so as to achieve isolation between the gate and the soldering position in the power device.

[0009] The second limiting member is disposed between the first positioning member and the second positioning member to limit the movement of the first positioning member and the second positioning member along the second direction and the third direction.

[0010] In one possible implementation, the first hole group further includes,

[0011] A fourth through hole is located on one side of the second through hole. The fourth through hole corresponds to the Kelvin source electrode in the power device. The cover extends along the first direction and passes through the fourth through hole to cover the upper surface of the Kelvin source electrode in the power device, so as to achieve isolation between the Kelvin source electrode in the power device and the soldering position.

[0012] In one embodiment, the first through hole and the fourth through hole are provided with guide grooves on the side near the second positioning member, and the guide grooves are connected to the first through hole and the fourth through hole.

[0013] In one embodiment, the first positioning member is provided with a first receiving groove along the first direction and close to the power module side, and two or more power devices in the power module are spaced apart along the third direction to form a device module. The device module is located in the first receiving groove, and the first hole group is connected to the first receiving groove.

[0014] In one possible implementation, the first limiting member includes,

[0015] The first limiting block is located on both sides of the first positioning member along the second direction, and the first limiting block is connected to the first positioning member;

[0016] The second limiting block is located on both sides of the first positioning member along the third direction, and the second limiting block is connected to the first positioning member.

[0017] In one possible implementation, the second limiting member includes,

[0018] A limiting groove is provided along the first direction in one of the first positioning member and the second positioning member;

[0019] A limiting post is disposed along the first direction in the other of the first positioning member and the second positioning member, and the limiting post is located in the limiting groove.

[0020] In one embodiment, the limiting groove is disposed on the first positioning member, and the limiting post is disposed on the second positioning member.

[0021] In one possible implementation, the limiting groove includes,

[0022] A first limiting groove is provided along the second direction;

[0023] The second limiting groove is arranged along the third direction, and the number of the first limiting groove and the number of the second limiting groove are not equal.

[0024] In one possible implementation, the limiting post includes,

[0025] A first limiting post is provided along the second direction;

[0026] The second limiting post is arranged along the third direction, and the number of the first limiting post and the number of the second limiting post are not equal.

[0027] In one possible implementation, the welding positions of the cover and the power device, as well as the Kelvin source electrode, are all spaced apart.

[0028] Compared to existing technologies, during the welding process, the first and second positioning components are used to position the metal welding parts, while the cover is used to isolate the gate and the welding position to prevent solder balls from falling into the gate and thus avoid product scrap. Attached Figure Description

[0029] Appendix Figure 1 This is a partial schematic diagram of a power module;

[0030] Appendix Figure 2 This is a schematic diagram of a welding positioning fixture for the power module of this application.

[0031] Appendix Figure 3 This is a schematic diagram of one structure of the first positioning component of this application;

[0032] Appendix Figure 4 This is a schematic diagram of a structure of the second positioning component of this application.

[0033] Explanation of the labels in the diagram:

[0034] X, first direction; Y, second direction; Z, third direction;

[0035] 10. Power module;

[0036] 100. Substrate;

[0037] 200 Power device; 210 Gate; 220 Soldering position; 230 Kelvin source electrode;

[0038] 300. Metal connectors;

[0039] 400. Tin solder;

[0040] 20. Welding positioning fixtures for power devices;

[0041] 500, First positioning element; 510, First hole group; 511, First through hole; 512, Second through hole; 513, Fourth through hole; 520, First receiving groove;

[0042] 600, First limiting component; 610, First limiting block; 620, Second limiting block;

[0043] 700, Second positioning element; 710, Third through hole; 720, Cover element;

[0044] 800, Second limiting component; 810, Limiting groove; 820, Limiting post. Detailed Implementation

[0045] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] The existing technology has a technical problem where solder balls fall onto the gate during soldering with solder, causing the product to be scrapped.

[0047] Therefore, this application provides a welding positioning fixture for a power module, characterized in that the welding positioning fixture for the power module is used to realize the welding positioning of power devices in the power module, and the silicon carbide welding positioning fixture includes,

[0048] A first positioning element is disposed on one side of the power module along a first direction. The first positioning element is provided with a first hole group through the first direction. The first hole group includes a first through hole and a second through hole. The first through hole is located on one side of the second through hole. The first through hole corresponds to the gate in the power device, and the second through hole corresponds to the welding position in the power device.

[0049] A first limiting member is connected to a first positioning member, and a limiting cavity is formed between the first limiting member and the first positioning member. The power module is located in the limiting cavity to form a limiting relationship between the power module and the first limiting member along a second direction and a third direction.

[0050] The second positioning member is disposed on the side of the first positioning member along the first direction and away from the power module. The second positioning member is provided with a third through hole along the first direction, and the third through hole is provided corresponding to the second through hole. The second positioning member is provided with a cover member along the first direction and close to the first positioning member. The cover member extends along the first direction and covers the upper surface of the gate in the power device after passing through the first through hole, so as to achieve isolation between the gate and the soldering position in the power device.

[0051] The second limiting member is disposed between the first positioning member and the second positioning member to limit the movement of the first positioning member and the second positioning member along the second direction and the third direction.

[0052] Example 1:

[0053] In current technology, the packaging of power modules in China, especially for silicon carbide modules, generally uses thick aluminum wire bonding for the chip surface. As power modules develop towards higher power densities, more and more requirements are being placed on module packaging technology. Currently, copper clip soldering is generally used to replace thick aluminum wire bonding. However, during vacuum reflow of copper clip soldering, the molten solder bubbles can cause solder ball splattering. The solder balls can further splatter onto the gate of the power device, and due to the wettability of gold, the solder balls can quickly expand and occupy part of the gate area, directly leading to product scrap.

[0054] Please refer to the attached document. Figure 1 To be continued Figure 4 As shown, the first direction X of this application refers to the height direction of the welding positioning fixture 20, that is, the direction from top to bottom or from bottom to top. In this application, the first positioning member 500 is positioned lower than the second positioning member 700, and the second positioning member 700 is positioned higher than the first positioning member 500. The second direction Y of this application refers to the length direction of the welding positioning fixture 20, that is, the direction from left to right or from right to left. The third direction Z of this application refers to the width direction of the welding positioning fixture 20, that is, the direction from front to back or from back to front.

[0055] Appendix Figure 1This is a partial schematic diagram of power module 10. Please refer to the attached diagram. Figure 1 As shown, to more clearly illustrate the specific structure of the power device 200, this application uses a partial schematic diagram to show the specific structure of the power module 10. The power module 10 of this application is a silicon carbide module. The silicon carbide module is one specific embodiment of this application; other modules using soldering can also utilize the soldering positioning fixture 20 of this application. The soldering positioning fixture 20 of this application can not only be used for attached... Figure 1 The power module 10 described in this embodiment can also be used for power modules 10 with other structures. The power module 10 is described in this embodiment only to more clearly explain the welding positioning fixture 20. Furthermore, the scope of protection of this application does not include the power module 10.

[0056] The power module 10 includes a substrate 100, which supports other components within the power module 10. The power module 10 also includes power devices 200, which are disposed on the substrate 100. Two or more power devices 200 are spaced apart along a third direction (Z) to form a device module. The power module 10 contains multiple device modules. Each power device 200 has a gate 210, a soldering position 220, and a Kelvin source 230, with the soldering position 220 serving as the source. The power module 10 also includes solder 400 and a metal connector 300. The metal connector 300 is connected to the soldering position 220 via the solder 400 and is made of copper. Furthermore, the solder 400 is composed of solder paste or solder pads, and both solder paste and solder pads are made of tin.

[0057] Appendix Figure 2 This is a schematic diagram of a welding positioning fixture 20 for the power module 10 of this application. Please refer to the attached diagram. Figure 2As shown, the welding positioning fixture 20 of this application includes a first positioning member 500, which is used to position the metal connector 300 and the second positioning member 700. The first positioning member 500 is disposed on one side of the power module 10 along the first direction X. Further, the first positioning member 500 is disposed on the side of the power module 10 along the first direction X where the power device 200 is disposed. The first positioning member 500 is provided with a first hole group 510 through it along the first direction X. The first hole group 510 is provided to further display the gate 210, the Kelvin source 230 and the metal connector 300, so as to facilitate the subsequent covering of the cover member 720 on the second positioning member 700 and the limiting of the metal connector 300. Furthermore, the first hole group 510 includes a first through hole 511, a second through hole 512, and a fourth through hole 513. The first through hole 511 and the fourth through hole 513 are located on one side of the second through hole 512. The first through hole 511 corresponds to the gate 210 in the power device 200, the second through hole 512 corresponds to the welding position 220 in the power device 200, and the metal connector 300 passes through the second through hole 512 along the first direction X. The fourth through hole 513 corresponds to the Kelvin source 230 in the power device 200.

[0058] Furthermore, the first positioning member 500 is provided with a first receiving groove 520 along the first direction X and close to the side of the power module 10. There are two or more power devices 200 in the power module 10 along the third direction Z to form a device module. Multiple device modules can be provided. The number of first receiving grooves 520 corresponds to the number of device modules. The device modules are located in the first receiving grooves 520, and the first hole group 510 is connected to the first receiving groove 520.

[0059] In one embodiment, the first positioning member 500 is a plate-like structure.

[0060] In one embodiment, a guide groove is provided on the side of the first through hole 511 and the fourth through hole 513 near the second positioning member 700. The diameter range of the guide groove is larger than the diameter range of the first through hole 511 and the fourth through hole 513. In actual use, the cover member 720 passes through the guide groove and the first through hole 511 or the guide groove and the fourth through hole 513 in sequence. The guide groove provides a guiding function for the cover member 720 to enter the first through hole 511 and the fourth through hole 513.

[0061] Please refer to the attached document. Figure 2As shown, the welding positioning fixture 20 of this application also includes a first limiting member 600, which is connected to the first positioning member 500. A limiting cavity is formed between the first limiting member 600 and the first positioning member 500, and the limiting cavity has an opening on the side facing the power module 10. The power module 10 enters the limiting cavity through the opening to achieve limiting between the first positioning member 500 and the power module 10 along the second direction Y and the third direction Z. At the same time, the power module 10 abuts against the first positioning member 500 to achieve limiting between the first positioning member 500 and the second positioning member 700 along the first direction X.

[0062] Please refer to the attached document. Figure 2 As shown, the welding positioning fixture 20 of this application also includes a second positioning member 700. The second positioning member 700 is used to position the metal connector 300 and set the cover 720. The positioning member is split into a first positioning member 500 and a second positioning member 700. The first positioning member 500 and the second positioning member 700 are set separately, and the cover 720 is set on the second positioning member 700. This is to avoid the situation where the surface of the first positioning member 500 near the power module 10 and the surface of the cover 720 near the power module 10 are on the same surface when the cover 720 is directly set on the first positioning member 500. This would further lead to solder balls spreading directly from the first positioning member 500 to the cover 720. In this application, after setting the first positioning member 500 and the second positioning member 700 simultaneously and setting the cover 720 on the second positioning member 700, the cover 720 is spaced apart from the welding position 220 and the Kelvin source electrode 230 in the power device 200.

[0063] Furthermore, the second positioning member 700 is disposed on the side of the first positioning member 500 along the first direction X and away from the power module 10. The second positioning member 700 has a third through hole 710 extending along the first direction X. The third through hole 710 is correspondingly disposed with the second through hole 512 to facilitate the metal connector 300 to further enter the third through hole 710 through the second through hole 512. A certain gap exists between the metal connector 300 and both the second through hole 512 and the third through hole 710. A cover member 720 is disposed on the side of the second positioning member 700 along the first direction X and close to the first positioning member 500. The cover member 720 extends along the first direction X and, after passing through the first through hole 511, covers the upper surface of the gate 210 in the power device 200 to achieve isolation between the gate 210 and the soldering position 220 in the power device 200. Meanwhile, the cover 720 is also correspondingly provided with the fourth through hole 513. After passing through the fourth through hole 513, the cover 720 covers the upper surface of the Kelvin source 230 in the power device 200, so as to isolate the Kelvin source 230 in the power device 200 from the soldering position 220 and prevent the solder balls on the soldering position 220 from falling into the Kelvin source 230 and the gate 210.

[0064] In one embodiment, the second positioning member 700 is a plate-like structure.

[0065] Please refer to the attached document. Figure 2 As shown, the welding positioning fixture 20 of this application also includes a second limiting member 800, which is disposed between the first positioning member 500 and the second positioning member 700. Furthermore, the second limiting member 800 is provided on both the first positioning member 500 and the second positioning member 700, thereby limiting the positioning between the first positioning member 500 and the second positioning member 700 along the second direction Y and the third direction Z. In specific use, the second positioning member 700 abuts against the first positioning member in the first direction X to achieve the limiting of the positioning between the second positioning member 700 and the first positioning member in the first direction X.

[0066] Appendix Figure 3 This is a structural schematic diagram of the first positioning element 500 of this application. Figure 4 This is a structural schematic diagram of the second positioning element 700 of this application. Please refer to the attached diagram. Figure 3 The first limiting member 600 includes a first limiting block 610 and a second limiting block 620. The first limiting blocks 610 are located on both sides of the first positioning member 500 along the second direction Y, and multiple first limiting blocks 610 are spaced apart along the second direction Y. The first limiting blocks 610 are connected to the first positioning member 500. The second limiting blocks 620 are located on both sides of the first positioning member 500 along the third direction Z, and multiple second limiting blocks 620 are spaced apart along the third direction Z. The second limiting blocks 620 are connected to the first positioning member 500.

[0067] Please refer to the attached document. Figure 3 and appendix Figure 4 The second limiting member 800 includes a limiting groove 810 and a limiting post 820. The limiting groove 810 is disposed along the first direction X in one of the first positioning member 500 or the second positioning member 700, and the limiting groove 810 penetrates through the first positioning member 500 or the second positioning member 700. The limiting post 820 is disposed along the first direction X in the other of the first positioning member 500 and the second positioning member 700, and the limiting post 820 is located within the limiting groove 810 to form a limiting relationship between the first positioning member 500 and the second positioning member 700 along the second direction Y and the third direction Z.

[0068] In one embodiment, a limiting groove 810 is disposed on a first positioning member 500, and a limiting post 820 is disposed on a second positioning member 700.

[0069] In one embodiment, to prevent mistaken placement, the limiting groove 810 and the limiting post 820 are not symmetrical. Further, the limiting groove 810 includes a first limiting groove 810 and a second limiting groove 810. The first limiting groove 810 is disposed along a second direction Y, and the second limiting groove 810 is disposed along a third direction Z. The number of the first limiting groove 810 and the second limiting groove 810 is unequal. The limiting post 820 includes a first limiting post 820 and a second limiting post 820. The first limiting post 820 is disposed along a second direction Y, and the second limiting post 820 is disposed along a third direction Z. The number of the first limiting post 820 and the second limiting post 820 is unequal. This prevents the first positioning member 500 and the second positioning member 700 from being placed in the wrong position.

[0070] Please refer to the attached document. Figure 4 As shown, a cover 720 is also provided on the second positioning member 700. The cover 720 is provided to further isolate the welding position from the gate and Kelvin source, so as to further prevent solder balls from falling onto the gate and Kelvin source.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0073] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A welding positioning fixture for a power module, characterized in that, The welding positioning fixture for the power module is used to position the power devices in the power module during welding. The welding positioning fixture for the power module includes, A first positioning element is disposed on one side of the power module along a first direction. The first positioning element is provided with a first hole group through the first direction. The first hole group includes a first through hole and a second through hole. The first through hole is located on one side of the second through hole. The first through hole corresponds to the gate in the power device, and the second through hole corresponds to the welding position in the power device. A first limiting member is connected to a first positioning member, and a limiting cavity is formed between the first limiting member and the first positioning member. The power module is located in the limiting cavity to form a limiting relationship between the power module and the first limiting member along a second direction and a third direction. The second positioning member is disposed on the side of the first positioning member along the first direction and away from the power module. The second positioning member is provided with a third through hole along the first direction, and the third through hole is provided corresponding to the second through hole. The second positioning member is provided with a cover member along the first direction and close to the first positioning member. The cover member extends along the first direction and covers the upper surface of the gate in the power device after passing through the first through hole, so as to achieve isolation between the gate and the soldering position in the power device. The second limiting member is disposed between the first positioning member and the second positioning member to limit the movement of the first positioning member and the second positioning member along the second direction and the third direction.

2. The welding positioning fixture for the power module according to claim 1, characterized in that, The first hole group also includes, A fourth through hole is located on one side of the second through hole. The fourth through hole corresponds to the Kelvin source electrode in the power device. The cover extends along the first direction and passes through the fourth through hole to cover the upper surface of the Kelvin source electrode in the power device, so as to achieve isolation between the Kelvin source electrode in the power device and the soldering position.

3. The welding positioning fixture for the power module according to claim 2, characterized in that, The first through hole and the fourth through hole are provided with guide grooves on the side near the second positioning member, and the guide grooves are connected to the first through hole and the fourth through hole.

4. The welding positioning fixture for the power module according to claim 2, characterized in that, The first positioning member has a first receiving groove along the first direction and close to the power module. Two or more power devices in the power module are spaced apart along the third direction to form a device module. The device module is located in the first receiving groove, and the first hole group is connected to the first receiving groove.

5. The welding positioning fixture for the power module according to claim 1, characterized in that, The first limiting component includes, The first limiting block is located on both sides of the first positioning member along the second direction, and the first limiting block is connected to the first positioning member; The second limiting block is located on both sides of the first positioning member along the third direction, and the second limiting block is connected to the first positioning member.

6. The welding positioning fixture for the power module according to claim 1, characterized in that, The second limiting member includes, A limiting groove is provided along the first direction in one of the first positioning member and the second positioning member; A limiting post is disposed along the first direction in the other of the first positioning member and the second positioning member, and the limiting post is located in the limiting groove.

7. The welding positioning fixture for the power module according to claim 6, characterized in that, The limiting groove is disposed on the first positioning member, and the limiting post is disposed on the second positioning member.

8. The welding positioning fixture for the power module according to claim 6, characterized in that, The limiting groove includes... A first limiting groove is provided along the second direction; The second limiting groove is arranged along the third direction, and the number of the first limiting groove and the number of the second limiting groove are not equal.

9. The welding positioning fixture for the power module according to claim 8, characterized in that, The limiting post includes... A first limiting post is provided along the second direction; The second limiting post is arranged along the third direction, and the number of the first limiting post and the number of the second limiting post are not equal.

10. The welding positioning fixture for the power module according to claim 2, characterized in that, The welding positions of the cover and the power device, as well as the Kelvin source electrode, are all spaced apart.

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