Power module terminal convenient for laser welding

Abstract

The utility model relates to a power module terminal convenient for laser welding, and the terminal comprises a connecting part which is provided with a welding point on the surface; a transition portion; the lower end of the shielding part is connected with at least one part of side edge of the connecting part, and one part of the upper end is connected with the transition part; wherein when the power module terminal is overlooked, the welding point position can be directly seen. According to the power module, the shielding part is arranged on at least one part of the side edge of the connecting part, and the shielding part shields molten pool metal splashing to the periphery in the laser welding process, so that the effect of protecting the substrate and the chip is achieved, and the quality of the power module is ensured. And meanwhile, the shielding part and the transition part cannot block a laser path, and implementation of laser welding is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a power module terminal facilitating laser welding. Background Art

[0002] For power module terminals, for example, in the invention patent application document with the document number CN119631579A and the title of "Method for Attaching a Terminal to a Metal Substrate Structure for a Semiconductor Power Module and a Semiconductor Power Module", the terminal includes a terminal body and terminal legs, and the terminal legs are coupled to the terminal body substantially perpendicularly in an L shape or a U shape. The terminal body is equivalent to a transition part, and the terminal legs are equivalent to connection parts.

[0003] The connection methods between the connection part and the substrate usually include reflow soldering, sintering, ultrasonic welding, pressure contact, and laser welding, etc. Among them, the laser welding process can achieve high-strength connection without filling additional materials or changing the original mechanical structure. Laser welding irradiates the surface of the connection part through laser, and the surface heat diffuses inward through heat conduction. By controlling parameters such as the width, energy, peak power, and repetition frequency of the laser pulse, the connection part is partially melted to form a specific molten pool, so that the connection part and the substrate are fused and connected.

[0004] However, due to the high thermal conductivity of copper material, low absorption rate of infrared wavelength light, and low viscosity in the molten state, splashing and voids are likely to occur. Since the terminal is integrally in an L shape or a U shape, the splashing of the molten pool metal on the terminal legs during the laser welding process easily falls onto the surface of the chip or the substrate through the unobstructed areas around, bringing risks such as short circuits.

[0005] It should be noted that the information disclosed in the above background art section is only used to strengthen the understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0006] Aiming at the deficiencies of the prior art, the embodiments of the utility model disclose a power module terminal facilitating laser welding to solve the problem that the splashing of the molten pool metal during terminal welding affects the quality of the power module.

[0007] The technical solution adopted by the utility model is as follows:

[0008] A power module terminal facilitating laser welding, the power module terminal includes: a connection part with welding points on the surface; a transition part; a shielding part, the lower end of which is connected to at least a part of the side of the connection part, and a part of the upper end of which is connected to the transition part; wherein, when looking down at the power module terminal, the welding points can be directly seen.

[0009] A further technical solution is that when the shielding portion extends to the upper end of the welding point, a first through hole is formed in the shielding portion corresponding to the welding point.

[0010] A further technical solution is that when the transition portion extends to the upper end of the welding point, a second through hole is formed in the transition portion corresponding to the welding point.

[0011] A further technical solution is that the connecting portion is a polygonal sheet body, and the shielding portion is connected to at least one side edge of the connecting portion.

[0012] A further technical solution is that when the shielding portion is connected to one side edge of the connecting portion, the shielding portion is vertically arranged, and the included angle between the connecting portion and the shielding portion is an obtuse angle.

[0013] A further technical solution is that the transition portion has several sheets, the transition portion has a first portion arranged overlapping and a second portion connecting the first portion, the second portion is arranged in a tree-like dispersion, and the connecting portion has several sheets arranged in parallel corresponding to the second portion, and the shielding portions are respectively connected between the corresponding connecting portion and the second portion.

[0014] A further technical solution is that the power module terminal includes a fixing member, the lower end of the fixing member presses on the connecting portion, and a third through hole is formed in the fixing member corresponding to the welding point.

[0015] A further technical solution is that the transition portion and the connecting portion are perpendicular to each other, the shielding portion and the connecting portion are perpendicular to each other, and the shielding portion encloses a fourth through hole to expose the welding point.

[0016] A further technical solution is that the shielding portion is a hollow cylinder, and the transition portion is inserted into the shielding portion.

[0017] A further technical solution is that a groove is formed at the welding point on the surface of the connecting portion.

[0018] The beneficial effects of the embodiments of the present invention are as follows:

[0019] (1) The power module terminal of the present invention includes a connecting portion, a transition portion and a shielding portion. By connecting at least a part of the side edges of the connecting portion at the lower end of the shielding portion, and connecting the upper end of the shielding portion to the transition portion, the shielding portion blocks the molten pool metal splashed during the laser welding process, plays a role in protecting the substrate and the chip, and ensures the quality of the power module. At the same time, the shielding portion and the transition portion do not block the laser path, which is convenient for the implementation of laser welding.

[0020] (2) Further, by designing the terminal into a structure of stacked multiple thin sheets, the thickness of each connecting part is reduced, the laser power can be controlled within a smaller range, avoiding spatter caused by a large amount of molten metal generated during welding. At the same time, the multiple connecting parts after bifurcation can be connected in parallel to multiple substrates, ensuring the quality of the power module while improving the installation efficiency of the power module.

[0021] (3) Further, by vertically arranging the shielding part and the connecting part, a fourth through hole is formed in the middle of the shielding part to expose the welding point. The shielding part or the shielding part together with the transition part functions to block the spatter of molten metal, which is applicable to the fish-eye terminal structure where the transition part and the connecting part are vertically arranged. Description of the Drawings

[0022] Figure 1 An isometric view of the power module terminal according to the first embodiment of the present utility model.

[0023] Figure 2 An isometric view of the power module terminal according to the first embodiment of the present utility model, where the shielding part is connected to multiple side edges of the connecting part.

[0024] Figure 3 An isometric view of the power module terminal according to the first embodiment of the present utility model, where the included angle between the connecting part and the shielding part is an obtuse angle.

[0025] Figure 4 A schematic structural view of the power module terminal according to the first embodiment of the present utility model, where the shielding part extends to the upper end of the welding point.

[0026] Figure 5 An isometric view of the power module terminal according to the first embodiment of the present utility model, where the transition part extends to the upper end of the welding point.

[0027] Figure 6 An isometric view of the power module terminal according to the first embodiment of the present utility model, where a groove is formed on the connecting part.

[0028] Figure 7 An isometric view of the power module terminal according to the second embodiment of the present utility model.

[0029] Figure 8 An isometric view of the power module terminal according to the second embodiment of the present utility model, where a fixing part is arranged.

[0030] Figure 9 An isometric view of the power module terminal according to the third embodiment of the present utility model.

[0031] Figure 10 An isometric view of the power module terminal according to the third embodiment of the present utility model, where the transition part is inserted and connected to the shielding part.

[0032] In the figure:

[0033] 1. Transition part; 11. Second through-hole; 12. First part; 13. Second part; 14. Fish-eye part; 2. Shielding part; 21. First through-hole; 22. Fourth through-hole; 3. Connecting part; 31. Groove; 4. Fixing part; 41. Cylinder; 42. Third through-hole. Specific embodiments

[0034] The following combines with the attached drawings to illustrate the specific embodiments of the present invention.

[0035] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further elaborates on the device proposed by the present invention in combination with the attached drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the attached drawings adopt a very simplified form and all use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the embodiments of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and understandable, please refer to the attached drawings. It should be known that the structures, scales, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed by the present invention.

[0036] First embodiment:

[0037] This embodiment discloses a power module terminal convenient for laser welding.

[0038] Figure 1 Is an axonometric view of the power module terminal of the first embodiment of the present invention. As Figure 1 shown, the power module terminal includes a connecting part 3, a transition part 1 and a shielding part 2. The surface of the connecting part 3 has welding points (not shown in the figure). The lower end of the shielding part 2 is connected to at least a part of the side of the connecting part 3, and a part of the upper end is connected to the transition part 1. Exemplarily, according to the requirements of the shear strength of the welding part, the welding points are in the form of dots or lines, and the welding points are preferably set at the center position of the welding surface. The connecting part 3 is a polygonal sheet body, and the shielding part 2 is connected to one side of the connecting part 3. Specifically, the transition part 1 and the connecting part 3 are horizontally arranged, and the shielding part 2 is vertically connected to the side of the connecting part 3. Figure 2 Is an axonometric view of the shielding part of the power module terminal of the first embodiment of the present invention connecting multiple sides of the connecting part. As Figure 2 shown, the shielding part 2 can be connected to all sides of the connecting part 3 to shield the periphery of the connecting part 3 and prevent the molten pool metal from splashing around.

[0039] Figure 3 Isometric view of the obtuse angle between the connecting part and the shielding part in the power module terminal of the first embodiment of the present invention. As Figure 3 shown, preferably, when the shielding part 2 is connected to a side of the connecting part 3, the shielding part 2 is vertically arranged, and the angle a between the connecting part 3 and the shielding part 2 is an obtuse angle. When the terminal is assembled with the substrate, the connecting part 3 is pressed to be horizontal to generate elastic deformation, and under the action of the elastic force, the connecting part 3 is in close contact with the welding surface. In other embodiments of the present invention, the connecting part 3 and the shielding part 2 can adopt an arc structure, as long as it can make the shielding part 2 block the molten pool metal splash, and the present invention will not be further limited thereto.

[0040] Among them, when looking down at the power module terminal, the welding point can be directly seen. Figure 4 Isometric view of the structure where the shielding part in the power module terminal of the first embodiment of the present invention extends to the upper end of the welding point. As Figure 4 shown, exemplarily, if the shielding part 2 extends to the upper end of the welding point, a first through hole 21 is opened on the shielding part 2 corresponding to the welding point. Figure 5 Isometric view of the structure where the transition part in the power module terminal of the first embodiment of the present invention extends to the upper end of the welding point. As Figure 5 shown, if the transition part 1 extends to the upper end of the welding point, a second through hole 11 is opened on the transition part 1 corresponding to the welding point. The shielding part 2 or the transition part 1 extending above the welding point can block the molten metal from splashing around, and at the same time opening the through hole will not affect the implementation of laser welding.

[0041] Figure 6 Isometric view of the groove opened on the connecting part in the power module terminal of the first embodiment of the present invention. As Figure 6 shown, further, a groove 31 is opened on the surface of the connecting part 3 at the welding point. Specifically, when the thickness of the connecting part 3 is relatively large, a higher power is required to melt the terminal material, there is more molten pool metal liquid, and the splash is larger. The preset groove 31 is equivalent to thinning the material at the welding point, and a smaller power can be used to melt the terminal material, with less molten pool metal liquid and less splash. The cross section of the groove 31 can be set in shapes such as Y-shaped, U-shaped or V-shaped, and multiple grooves 31 can also be distributed on the surface of the connecting part 3.

[0042] In this embodiment, by arranging the shielding part 2 on at least a part of the side of the connecting part 3, the upper end of the shielding part 2 is connected to the transition part 1, and the shielding part 2 blocks the molten pool metal splashing during the laser welding process, playing a role in protecting the substrate and the chip, and ensuring the quality of the power module. At the same time, the shielding part 2 and the transition part 1 do not block the laser path, facilitating the implementation of laser welding.

[0043] Second embodiment:

[0044] Based on the first embodiment, the second embodiment is further optimized and refined.

[0045] Figure 7 This is an axonometric view of the power module terminal of the second embodiment of the present utility model. As Figure 7 shown, the transition portion 1 has several sheets. The transition portion 1 has a first portion 12 arranged in an overlapping manner and a second portion 13 connecting the first portion 12. The second portion 13 is arranged in a tree-like dispersion. The connecting portion 3 has several sheets arranged in parallel corresponding to the second portion 13. The shielding portion 2 is respectively connected between the corresponding connecting portion 3 and the second portion 13. Exemplarily, the transition portion 1 and the connecting portion 3 are horizontally arranged, and the shielding portion 2 is vertically arranged and in the same vertical plane. By controlling the length of the shielding portion 2, all the connecting portions 3 are in the same horizontal plane. When looking down at the power module terminal, the connecting portions 3 do not overlap each other.

[0046] Figure 8 This is an axonometric view of the power module terminal of the second embodiment of the present utility model with a fixing member provided. As Figure 8 shown, further, the power module terminal includes a fixing member 4. The lower end of the fixing member 4 presses on the connecting portion 3, and the fixing member 4 is provided with a third through hole 42 corresponding to the welding point position. Exemplarily, a column 41 extends downward from the lower end of the fixing member 4 corresponding to the connecting portion 3, which is convenient for pressing on the connecting portion 3. The third through hole 42 can be a through square hole, a round hole, etc.

[0047] In this embodiment, by designing the terminal into a structure of multiple thin sheets stacked, the thickness of each connecting portion 3 is reduced, the laser power can be controlled within a smaller range, avoiding spatter caused by a large amount of molten metal generated during welding. At the same time, the multiple connecting portions 3 after branching can be connected in parallel to multiple substrates, ensuring the quality of the power module while improving the installation efficiency of the power module.

[0048] Third embodiment:

[0049] Based on the first embodiment, the third embodiment is further optimized and refined.

[0050] Figure 9 This is an axonometric view of the power module terminal of the third embodiment of the present utility model. As Figure 9 shown, the transition portion 1 and the connecting portion 3 are perpendicular to each other, the shielding portion 2 and the connecting portion 3 are perpendicular to each other, and the shielding portion 2 encloses a fourth through hole 22 to expose the welding point position. Exemplarily, the lower end of the transition portion 1 is connected to a side edge of the connecting portion 3, the lower end of the shielding portion 2 is connected to the remaining side edges of the connecting portion 3, and at the same time, the side edges of the shielding portion 2 are connected to both sides of the transition portion 1. The shielding portion 2 and the transition portion 1 both play a shielding role. The upper end of the transition portion 1 also has a fish-eye portion 14.

[0051] Figure 10An isometric view of the insertion connection between the transition part and the shielding part in the power module terminal of the third embodiment of the present utility model. As Figure 10 shown, in other embodiments of the present utility model, the shielding part 2 is a hollow column, the transition part 1 is inserted and connected with the shielding part 2, the lower end of the shielding part 2 is connected to the connecting part 3, and after laser welding, the transition part 1 is inserted into the fourth through hole 22 of the shielding part 2.

[0052] In this embodiment, by vertically arranging the shielding part 2 and the connecting part 3, a fourth through hole 22 is formed in the middle of the shielding part 2 to expose the welding point, and the shielding part 2 or the shielding part 2 and the transition part 1 together play a role in blocking the splash of molten metal, which is applicable to the fish-eye terminal structure in which the transition part 1 and the connecting part 3 are vertically arranged.

[0053] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0054] The above-described embodiments only represent several implementation manners of the present utility model, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the utility model patent shall be subject to the appended claims.

Claims

1. A power module terminal facilitating laser welding, characterized in that, The power module terminal includes: A connection part with welding points on its surface; A transition part; A shielding part, the lower end of which is connected to at least a part of the side of the connection part, and a part of the upper end of which is connected to the transition part; Wherein, when looking down at the power module terminal, the welding points can be directly seen.

2. The power module terminal facilitating laser welding according to claim 1, wherein: When the shielding part extends to the upper end of the welding point, a first through hole is opened on the shielding part corresponding to the welding point.

3. The power module terminal facilitating laser welding according to claim 1, wherein: When the transition part extends to the upper end of the welding point, a second through hole is opened on the transition part corresponding to the welding point.

4. The power module terminal facilitating laser welding according to any one of claims 1 to 3, characterized in that: The connection part is a polygonal sheet body, and the shielding part is connected to at least one side of the connection part.

5. The power module terminal facilitating laser welding according to claim 4, characterized in that: When the shielding part is connected to one side of the connection part, the shielding part is vertically arranged, and the included angle between the connection part and the shielding part is an obtuse angle.

6. The power module terminal facilitating laser welding according to claim 1, wherein: The transition part has several sheets. The transition part has a first part arranged in an overlapping manner and a second part connected to the first part. The second part is arranged in a tree-like dispersion manner. The connection part has several sheets arranged in parallel corresponding to the second part. The shielding parts are respectively connected between the corresponding connection part and the second part.

7. The power module terminal facilitating laser welding according to claim 6, wherein: The power module terminal includes a fixing part, the lower end of which presses the connection part, and a third through hole is opened on the fixing part corresponding to the welding point.

8. The power module terminal facilitating laser welding according to claim 1, wherein: The transition part and the connection part are perpendicular to each other, the shielding part and the connection part are perpendicular to each other, and the shielding part encloses a fourth through hole to expose the welding point.

9. The power module terminal facilitating laser welding according to claim 8, wherein: The shielding part is a hollow cylinder, and the transition part is inserted into the shielding part.

10. The power module terminal facilitating laser welding according to claim 1, wherein: A groove is opened at the position of the welding point on the surface of the connection part.

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