Pressing block assembly for preventing pseudo soldering of needle-shaped terminal
By optimizing the design of the limiting fixture and pressure block assembly, the problem of poor contact between the pin terminal and the DBC substrate was solved, uniform pressure and gas management were achieved, and the welding quality was significantly improved while reducing costs.
Patent Information
- Application Number
- CN202422400289.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-09-30
AI Technical Summary
In traditional soldering processes, the pin terminals and DBC substrates have poor contact, leading to cold solder joints. In addition, uneven pressure causes solder overflow or cold solder joints to occur frequently, affecting product qualification rates and increasing production costs.
A pressure block assembly including a limiting fixture, a pressure block and a partition is designed. Through precise limiting hole positioning, a stable nut fixing structure and a rectangular exhaust groove, it ensures that the needle terminal is in full contact with the DBC substrate, applies uniform pressure and prevents cold soldering.
The welding quality of pin terminals is improved, problems such as inaccurate positioning, uneven pressure and improper gas management are solved, and product quality is significantly improved while reducing production costs.
Smart Images
Figure CN223363126U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of power semiconductor technology, and in particular relates to a pressure block assembly for preventing cold soldering of needle-shaped terminals. Background Art
[0002] In the power semiconductor module industry, pin terminals are widely used for power and signal lead-out in medium-power products due to their flexibility. However, the traditional soldering process relies on the pin terminal's own weight to contact the DBC substrate with solder paste, and to maintain a stable position using a limiting fixture. This design has the problem of difficult to control the limiting gap - a gap that is too large will lead to inaccurate positioning, while a gap that is too small will cause friction during the soldering process, thereby affecting the sufficient contact between the pin terminal and the DBC substrate, and ultimately causing cold solder joints. In addition, when a pressure plate is used to apply pressure to multiple pin terminals, due to the inconsistent heights of the terminals, it will also cause solder overflow due to excessive pressure or cold solder joints due to insufficient pressure, which not only reduces the product qualification rate but also increases production costs. The root cause of the above problems lies in manufacturing tolerances and the deformation of the material during thermal cycles, which lead to friction and poor contact. Utility Model Content
[0003] The main purpose of this application is to provide a pressure block assembly for preventing cold solder joints of needle terminals. This application optimizes the needle terminal pressure block so that all needle terminals can fully contact the DBC substrate with solder paste during the welding process, thereby preventing cold solder joints.
[0004] To achieve the above objectives, this application provides the following technical solutions:
[0005] A pressure block assembly for preventing cold soldering of a needle terminal, the pressure block assembly comprising: a limiting jig, the upper end surface of the limiting jig being provided with a plurality of jacks, each of which being provided with a pressure block, the lower end surface of the limiting jig being provided with a plurality of limiting holes, the plurality of limiting holes corresponding one-to-one to the plurality of jacks; a needle terminal being provided in each of the limiting holes, the pressure block being arranged perpendicularly to the needle terminal based on the jacks and the limiting holes.
[0006] Optionally, the pressing block includes: a pressing block head, a pressing block neck and a pressing block base which are sequentially arranged in the thickness direction of the limiting fixture, and the pressing block head, the pressing block neck and the pressing block base are integrally formed.
[0007] Optionally, the pressure block assembly also includes: a first partition and a second partition with the same structure stacked on one side of the limiting fixture, a plurality of first through holes are provided on the first partition, and a plurality of second through holes are provided on the second partition, the first through holes and the second through holes have the same diameter and are both provided in one-to-one correspondence with the sockets.
[0008] Optionally, the diameters of the pressure block head and the pressure block base are the same and smaller than the diameters of the first through hole and the second through hole, and the diameter of the pressure block neck is larger than the diameters of the first through hole and the second through hole; the first partition and the second partition are stacked on the pressure block, wherein the first partition is arranged on the pressure block base, and the second partition is arranged on the pressure block head.
[0009] Optionally, the connection between the pressure block head and the pressure block neck is a first connection, the connection between the pressure block base and the pressure block neck is a second connection, and both the first connection and the second connection are step-shaped.
[0010] Optionally, nuts are provided at the four corner edges of the limiting fixture, and first screw holes and second screw holes of the same size are respectively provided at the four corner edges of the first partition plate and the second partition plate, and the first screw holes and the second screw holes match the nuts.
[0011] Optionally, the nut includes: a first internal thread, an external thread and a second internal thread, wherein the diameters of the first internal thread and the second internal thread are the same and smaller than the diameters of the first screw hole and the second screw hole, the diameter of the external thread is larger than the diameters of the first screw hole and the second screw hole, the first partition is threadedly connected to the first internal thread through the first screw hole, and the second partition is threadedly connected to the second internal thread through the second screw hole.
[0012] Optionally, the first internal thread and the second internal thread have the same thread length and are greater than the length of the neck of the pressing block.
[0013] Optionally, exhaust grooves are provided at corresponding positions of the first partition plate and the second partition plate.
[0014] Optionally, the exhaust groove is a rectangular exhaust groove.
[0015] Compared with the existing technology, this application can bring the following technical effects:
[0016] This application ensures that the needle terminal is in full contact with the DBC substrate during the welding process through an optimized pressure block design, precise limit hole positioning, a stable nut fixing structure, and an effective rectangular exhaust groove. It can solve common problems in traditional welding processes such as inaccurate positioning, uneven pressure, and improper gas management, thereby significantly improving the welding quality of the needle terminal. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a front view of a pressing block assembly for preventing cold welding of a pin-shaped terminal provided by one embodiment of the present application;
[0018] Figure 2 This is a disassembled schematic diagram of a pressing block assembly for preventing cold soldering of a pin-shaped terminal provided by another embodiment of the present application;
[0019] Figure 3 This is a bottom view of a pressing block assembly for preventing cold soldering of a pin-shaped terminal provided by another embodiment of the present application;
[0020] Figure 4 is a schematic structural diagram of a compression block provided by another embodiment of the present application;
[0021] Figure 5 This is a schematic diagram of the positions of a pressing block assembly and a pin-shaped terminal for preventing cold soldering of a pin-shaped terminal provided by another embodiment of the present application;
[0022] Figure 6 This is a cross-sectional view of a pressing block assembly for preventing cold soldering of a needle terminal, provided in another embodiment of the present application.
[0023] The following are the descriptions of the reference numerals:
[0024] 1. Limiting fixture; 2. First partition; 3. Second partition; 4. Press block; 4-1. Press block head; 4-2. Press block base; 4-3. Press block neck; 4-4. First connection; 4-5. Second connection; 5. Nut; 5-1. First internal thread; 5-2. External thread; 5-3. Second internal thread; 6-1. First screw hole; 6-2. Second screw hole; 7. Exhaust groove; 8-1. First through hole; 8-2. Second through hole; 9. Limiting hole; 10. Jack; 11. Pin terminal; 12. DBC substrate. DETAILED DESCRIPTION
[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.
[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0027] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.
[0028] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0029] Figure 1 This is a front view of a pressing block assembly for preventing cold welding of a pin-shaped terminal according to one embodiment of the present application. Figure 2 This is a disassembled schematic diagram of a pressing block assembly for preventing cold soldering of a needle terminal provided by another embodiment of the present application. Figure 3 1 is a bottom view of a pressing block assembly for preventing cold welding of a pin-shaped terminal provided by another embodiment of the present application, as shown in FIG. Figure 1 、 Figure 2 and Figure 3 As shown, the pressure block assembly includes: a limiting fixture 1, the upper end surface of the limiting fixture 1 is provided with a plurality of sockets 10, each socket 10 is provided with a pressure block 4, the lower end surface of the limiting fixture 1 is provided with a plurality of limiting holes 9, and the plurality of limiting holes 9 correspond one-to-one to the plurality of sockets 10; each of the limiting holes 9 is provided with a pin-shaped terminal 11, and the pressure block 4 is vertically arranged based on the socket 10 and the limiting hole 9 and the pin-shaped terminal 11.
[0030] In this embodiment, the limiting holes 9 correspond one-to-one with the pressing blocks 4 located on the upper end surface of the limiting fixture 1, which can ensure that each needle terminal 11 can be accurately placed in the predetermined position. This one-to-one matching relationship helps to maintain the consistency of all needle terminals 1, and can maintain high precision even in mass production. In addition, since each needle terminal 1 is independently fixed in a specific limiting hole 9, this can not only help the needle terminal 11 remain stable before welding, but also reduce the deviation of the needle terminal 11 caused by movement or vibration. Furthermore, when all needle terminals 11 are in the correct position, it can ensure that the needle terminal 11 is in uniform contact with the solder paste on the DBC substrate 12, thereby promoting good bonding between the metals. In this way, the occurrence of cold solder joints can be effectively avoided, thereby avoiding welding quality problems caused by inaccurate positioning of the needle terminal 11.
[0031] In another exemplary embodiment, the pressing block 4 includes: a pressing block head 4-1, a pressing block neck 4-3 and a pressing block base 4-2 arranged in sequence in the thickness direction of the limiting fixture 1, and the pressing block head 4-1, the pressing block neck 4-3 and the pressing block base 4-2 are integrally formed.
[0032] In this embodiment, the integrally formed pressure block 4 has superior mechanical strength, better able to withstand the pressure during welding, reduce deformation or damage caused by loose connections between components, and help ensure that the pressure block remains stable throughout the welding process. In addition, due to its integrated structure, pressure from the pressure block head 4-1 to the pressure block base 4-2 can be more evenly transmitted to the pin-shaped terminal 11, thereby ensuring that each pin-shaped terminal 11 is subjected to uniform pressure, thereby effectively preventing the occurrence of cold welds.
[0033] In another exemplary embodiment, the pressure block assembly also includes: a first partition plate 2 and a second partition plate 3 with the same structure stacked on one side of the limiting fixture 1, a plurality of first through holes 8-1 are provided on the first partition plate 2, and a second through hole 8-2 is provided on the second partition plate 3, and the diameters of the first through holes 8-1 and the second through holes 8-2 are the same and are both arranged one-to-one corresponding to the socket 10.
[0034] In this embodiment, the through holes (i.e., the first through hole 8-1 and the second through hole 8-2) on the first partition plate 2 and the second partition plate 3 are aligned with the socket 10 on the limiting fixture 1, which can ensure that each pressing block 4 and the needle terminal 11 can be accurately placed in the predetermined position, helping to maintain the consistency of all the needle terminals 11.
[0035] In another exemplary embodiment, the diameters of the pressure block head 4-1 and the pressure block base 4-2 are the same and smaller than the diameters of the first through hole 8-1 and the second through hole 8-2, and the diameter of the pressure block neck 4-3 is larger than the diameters of the first through hole 8-1 and the second through hole 8-2; wherein the first partition 2 is arranged on the pressure block base 4-2, and the second partition 3 is arranged on the pressure block head 4-1.
[0036] In this embodiment, the design of two layers of partitions allows the pressing block 4 to be stably clamped between the two layers of partitions. When the pressing block 4 applies downward pressure, the pressing block neck 4-3 is stuck between the first partition 2 and the second partition 3, ensuring that the pressure can be evenly transmitted to the pin-shaped terminal 11, thereby avoiding problems of cold solder joints or solder overflow caused by uneven pressure. The diameter of the pressing block neck 4-3 is set to be larger than the diameters of the first through hole 8-1 and the second through hole 8-2, ensuring that the pressing block 4 can be stably placed between the first partition 2 and the second partition 3 during the soldering process of the pin-shaped terminal 11, and applying sufficient pressure to the pin-shaped terminal 11, thereby ensuring that the pin-shaped terminal 11 is in full contact with the solder paste on the DBC substrate 12 (e.g., Figure 5 and Figure 6 (as shown), thereby preventing the occurrence of cold solder joints. Furthermore, the diameters of the pressure block head 4-1 and pressure block base 4-2 are smaller than those of the first through-hole 8-1 and the second through-hole 8-2, allowing the pressure block 4 to move freely in the vertical direction, facilitating adjustment of the pressure block 4 to the correct position. Simultaneously, the larger diameter of the pressure block neck 4-3 prevents horizontal displacement of the pressure block 4, thereby ensuring precise positioning of the pin-shaped terminal 11.
[0037] In addition, please refer to Figure 4 The connection between the pressure block head 4-1 and the pressure block neck 4-3 is a first connection 4-4, and the connection between the pressure block base 4-2 and the pressure block neck 4-3 is a second connection 4-5. Both the first connection 4-4 and the second connection 4-5 are stepped. The stepped design helps evenly distribute the pressure of the pressure block 4 on the pin-shaped terminal 11 during the welding process. When the pressure block 4 applies downward pressure, the stepped structure can effectively transfer the pressure to each pin-shaped terminal 11, ensuring that the pressure on each pin-shaped terminal 11 is consistent. This can avoid problems such as cold solder joints or solder overflow caused by uneven pressure on the pin-shaped terminal 11, thereby improving the welding quality of the pin-shaped terminal 11.
[0038] In summary, the pressure block 4 with the above-mentioned structural characteristics can not only solve the problem of difficult control of the limiting gap in the traditional process, but also improve the problem of uneven pressure distribution caused by the inconsistent heights of the needle terminals 11 during the welding process, ultimately achieving the purpose of improving product quality and reducing manufacturing costs.
[0039] In another exemplary embodiment, nuts 5 are provided at the four corner edges of the limiting fixture 1, and first screw holes 6-1 and second screw holes 6-2 of the same size are respectively provided at the four corner edges of the first partition 2 and the second partition 3, and the first screw holes 6-1 and the second screw holes 6-2 match the nuts 5.
[0040] In this embodiment, the nut 5 includes a first internal thread 5-1, an external thread 5-2, and a second internal thread 5-3. The diameters of the first internal thread 5-1 and the second internal thread 5-3 are the same and smaller than the diameters of the first screw hole 6-1 and the second screw hole 6-2. The diameter of the external thread 5-2 is larger than the diameters of the first screw hole 6-1 and the second screw hole 6-2. The first partition 2 is threadedly connected to the first internal thread 5-1 through the first screw hole 6-1, and the second partition 3 is threadedly connected to the second internal thread 5-3 through the second screw hole 6-2. In addition, the thread lengths of the first internal thread 5-1 and the second internal thread 5-3 are the same and greater than the length of the pressure block neck 4-3.
[0041] It should be noted that in actual production, the height of the pin terminals 11 may vary due to factors such as manufacturing tolerances and material thermal expansion. Therefore, by setting the thread lengths of the first internal threads 5-1 and the second internal threads 5-3 to be greater than the length of the pressure block neck 4-3, the distance between the first and second partitions 2 and 3 can be finely adjusted by rotating the nut 5, thereby better accommodating these subtle height differences. This ensures that even with pin terminals 11 of varying heights, they can be stably pressed against the DBC substrate 12 by the pressure block 4 during the welding process. For example, after all pin terminals 11 are placed, the position of the fine-tuning nut 5 can be adjusted to ensure that the pressure applied by the pressure block 4 to each pin terminal 11 is more uniform. If some pin terminals 11 are taller than others, tightening the nut at the corresponding position can reduce the gap between the first and second partitions 2 and 3 at that location, thereby moving the pressure block 4 downward a little further and increasing the pressure on that pin terminal; and vice versa. In summary, by adjusting the nut 5 to control the distance between the first partition 2 and the second partition 3, the problem of inconsistent height of the needle terminal 11 can be effectively addressed, thereby ensuring that the pressure of the needle terminal 11 is evenly distributed during welding, thereby significantly improving the welding quality.
[0042] Please continue to refer to Figures 1 to 3 In another exemplary embodiment, exhaust grooves 7 are provided at corresponding positions of the first partition plate 2 and the second partition plate 3 .
[0043] In this embodiment, during the welding process of the pin terminal 11 in the high-temperature furnace, reducing gases (such as formic acid) are released. These gases can help remove oxides from the weld surface. By providing exhaust slots 7 on the first and second separators 2 and 3, the reducing gas can more effectively reach the weld area, thereby more thoroughly removing the oxide layer on the pin terminal 1 and the DBC substrate 12. Furthermore, the exhaust slots 7 can help exhaust other impurities and volatile substances generated during the welding process, such as flux residue and other contaminants, thereby keeping the weld area clean, preventing impurities from affecting weld quality, and improving the mechanical strength and electrical performance of the welded joint. Furthermore, the exhaust slots 7 can provide additional channels for the reducing gas to flow freely within and outside the weld area, ensuring that a sufficient supply of reducing gas is available throughout the weld area, ensuring that all welds receive effective reduction treatment. Furthermore, it should be noted that the venting grooves 7 are rectangular. This design is due to their larger surface area, providing additional channels for the free flow of reducing gas within and outside the welding area. This ensures a sufficient supply of reducing gas throughout the welding area, ensuring that all welds receive effective reduction treatment. Furthermore, during the welding process, the pin terminal 11 undergoes a thermal cycle. The larger surface area provided by the rectangular venting grooves 7 reduces the heating and cooling time during welding, thereby improving the utilization efficiency of the high-temperature furnace.
[0044] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A pressure block assembly for preventing cold welding of pin-shaped terminals, characterized in that: The pressing block assembly comprises: A limiting jig (1), wherein the upper end surface of the limiting jig (1) is provided with a plurality of jacks (10), each jack (10) is provided with a pressure block (4), and the lower end surface of the limiting jig (1) is provided with a plurality of limiting holes (9), and the plurality of limiting holes (9) correspond one-to-one to the plurality of jacks (10); A needle-shaped terminal (11) is provided in each of the limiting holes (9), and the pressing block (4) is vertically arranged with respect to the needle-shaped terminal (11) based on the insertion hole (10) and the limiting hole (9).
2. The pressing block assembly according to claim 1, characterized in that The pressing block (4) comprises: A pressing block head (4-1), a pressing block neck (4-3) and a pressing block base (4-2) are sequentially arranged in the thickness direction of the limiting jig (1); the pressing block head (4-1), the pressing block neck (4-3) and the pressing block base (4-2) are integrally formed.
3. The pressing block assembly according to claim 2, characterized in that: The pressing block assembly further comprises: A first partition plate (2) and a second partition plate (3) having the same structure are stacked on one side of the limiting fixture (1); a plurality of first through holes (8-1) are provided on the first partition plate (2); a plurality of second through holes (8-2) are provided on the second partition plate (3); the first through holes (8-1) and the second through holes (8-2) have the same diameter and are arranged in one-to-one correspondence with the insertion holes (10).
4. The pressing block assembly according to claim 3, characterized in that The diameters of the pressing block head (4-1) and the pressing block base (4-2) are the same and smaller than the diameters of the first through hole (8-1) and the second through hole (8-2), and the diameter of the pressing block neck (4-3) is larger than the diameters of the first through hole (8-1) and the second through hole (8-2); The first partition (2) is arranged on the pressing block base (4-2), and the second partition (3) is arranged on the pressing block head (4-1).
5. The briquette assembly according to any one of claims 2 to 4, characterized in that: The connection between the pressing block head (4-1) and the pressing block neck (4-3) is a first connection (4-4), and the connection between the pressing block base (4-2) and the pressing block neck (4-3) is a second connection (4-5). Both the first connection (4-4) and the second connection (4-5) are step-shaped.
6. The pressing block assembly according to claim 3, characterized in that: Nuts (5) are provided at the four corner edges of the limiting fixture (1), and first screw holes (6-1) and second screw holes (6-2) of the same size are provided at the four corner edges of the first partition (2) and the second partition (3), respectively. The first screw holes (6-1) and the second screw holes (6-2) match the nuts (5).
7. The pressing block assembly according to claim 6, characterized in that The nut (5) comprises: A first internal thread (5-1), an external thread (5-2) and a second internal thread (5-3), wherein the diameters of the first internal thread (5-1) and the second internal thread (5-3) are the same and smaller than the diameters of the first screw hole (6-1) and the second screw hole (6-2), the diameter of the external thread (5-2) is larger than the diameters of the first screw hole (6-1) and the second screw hole (6-2), the first partition (2) is threadedly connected to the first internal thread (5-1) through the first screw hole (6-1), and the second partition (3) is threadedly connected to the second internal thread (5-3) through the second screw hole (6-2).
8. The pressing block assembly according to claim 7, characterized in that The thread lengths of the first internal thread (5-1) and the second internal thread (5-3) are the same and are greater than the length of the pressing block neck (4-3).
9. The pressing block assembly according to claim 3, characterized in that: Exhaust slots (7) are provided at corresponding positions of the first partition plate (2) and the second partition plate (3).
10. The pressing block assembly according to claim 9, characterized in that: The exhaust groove (7) is a rectangular exhaust groove.