Reflow soldering positioning tool for vertical adapter pins of aluminum-based circuit board

Abstract

A reflow soldering positioning tool for vertical adapter pins of an aluminum-based circuit board, comprising a base, a guide plate and a limiting plate, the limiting plate being located between the base and the guide plate, the reverse side of the base being capable of being placed on a reflow soldering device, the front side of the base being provided with an aluminum substrate mounting groove, the front side of the limiting plate being slidably attached to the reverse side of the guide plate, the guide plate and the limiting plate being prevented from separating by a connecting screw, the two being capable of sliding relative to each other by adjusting the screw, and the guide plate being detachably connected to the base by a plurality of connecting blocks, a plurality of pin step holes being provided on the guide plate, and a plurality of pin through holes being provided on the limiting plate. The present application can simultaneously vertically position a plurality of adapter pins on an aluminum-based circuit board, facilitating batch automatic welding by a reflow soldering device, being simple to operate, low in implementation cost, capable of realizing automation in the production process, and having high verticality and high production efficiency in the welding of the vertical adapter pins of the aluminum-based circuit board.

Description

Technical Field

[0001] This invention relates to the field of reflow soldering of adapter pins on aluminum-based circuit boards, and more particularly to a reflow soldering positioning fixture for vertical adapter pins on aluminum-based circuit boards. Background Technology

[0002] With the rapid development of electronic technology, the power density of power modules in fields such as communications, automobiles, and military is constantly increasing, and traditional printed circuit boards (PCBs) can hardly meet the heat dissipation requirements. Aluminum-based PCBs have fast heat diffusion and good heat dissipation, so they are widely used in high-power-density applications. Due to structural limitations, aluminum-based PCBs are usually only suitable for surface mount STM processes. Because aluminum-based PCBs lack pin holes, vertical adapter pins are difficult to fix due to their small contact area, making it impossible to perform soldering processes with surface mount components. Generally, surface mount components are first reflow soldered, and then adapter pins are fixed using tooling. Each adapter pin on the same aluminum-based PCB is then manually soldered. This soldering method has low production efficiency, high cost, and requires high soldering skills from workers. However, there is a lack of tooling that can simultaneously and vertically position multiple adapter pins on an aluminum-based PCB, making it difficult to automate batch soldering using reflow soldering equipment. Summary of the Invention

[0003] The purpose of this invention is to provide a reflow soldering positioning fixture for vertical adapter pins on aluminum-based circuit boards, which can simultaneously and vertically position multiple adapter pins on the aluminum-based circuit board, facilitating batch automated soldering using reflow soldering equipment.

[0004] The technical solution adopted by this invention to solve the above-mentioned technical problems is: a reflow soldering positioning fixture for vertical adapter pins of an aluminum-based circuit board, used to position multiple adapter pins on the soldering surface of an aluminum substrate. The adapter pins are stepped cylinders, with the larger diameter end of the adapter pin used to place on the soldering surface of the aluminum substrate for soldering, ensuring that the length direction of the adapter pin is perpendicular to the soldering surface. The positioning fixture includes a base, a guide plate, and a limiting plate. The length directions of the base, guide plate, and limiting plate are parallel to each other. The limiting plate is located between the base and the guide plate. The back of the base can be placed on a reflow soldering device. The front of the base has an aluminum substrate mounting groove, allowing the aluminum substrate to be placed horizontally in the mounting groove with the soldering surface of the aluminum substrate facing the back of the limiting plate. The front of the limiting plate is aligned with the guide plate. The guide plate has multiple connecting blocks and multiple threaded holes on its reverse side. The limiting plate has multiple connecting block slots and multiple connecting screw slots. The connecting blocks pass through the multiple connecting block slots. The connecting blocks are detachably connected to the front of the base. Connecting screws are screwed into the multiple threaded holes. The connecting screws pass through the multiple connecting screw slots. The screw heads of the connecting screws contact the reverse side of the limiting plate, thereby restricting the separation of the front of the limiting plate from the reverse side of the guide plate. An adjusting screw passes through the side of the limiting plate. One end of the adjusting screw rests on the side of the guide plate. The length directions of the connecting block slots and the connecting screw slots are parallel to the length direction of the adjusting screw, so that the adjusting screw can push the guide plate to move relative to the limiting plate.

[0005] The guide plate has multiple stepped pin holes, and the limiting plate has multiple through pin holes. When multiple connecting blocks cooperate to support the guide plate and the limiting plate on the front of the base, the stepped pin holes and through pin holes are perpendicular to the welding surface of the aluminum substrate. The small-diameter opening of the stepped pin hole is located on the front of the guide plate, and the large-diameter opening of the stepped pin hole is located on the back of the guide plate. The small-diameter diameter of the stepped pin hole matches the small-diameter diameter of the adapter pin, and the large-diameter diameter of both the stepped pin hole and the through pin hole matches the large-diameter diameter of the adapter pin. When the guide plate and the limiting plate are aligned, the large diameter ends of multiple pin through holes and multiple pin stepped holes can be aligned one by one, so that the adapter pin can pass through the pin through holes and enter the pin stepped holes. When the small diameter end of the adapter pin passes through the small diameter end of the pin stepped hole, and the stepped part of the pin stepped hole is in contact with the stepped shoulder of the adapter pin, the large diameter end of the adapter pin is completely inside the large diameter end of the pin stepped hole. When the guide plate and the limiting plate are staggered, the front of the limiting plate can simultaneously block the large diameter ends of multiple pin stepped holes.

[0006] Preferably, both the guide plate and the limiting plate are rectangular plates. The limiting plate has bent plates on both sides along the width direction for screwing in the adjusting screws. The length direction of the connecting block groove and the connecting screw groove are parallel to the width direction of the limiting plate.

[0007] Preferably, the reverse side of the guide plate is provided with four cylindrical connecting blocks, which are located near the four corners of the guide plate.

[0008] Preferably, the ends of two connecting blocks located at one diagonal position are provided with connecting block positioning protrusions, and the ends of two connecting blocks located at another diagonal position are provided with connecting block positioning recesses. The front of the base is provided with connecting block positioning through holes that match the two connecting block positioning protrusions respectively, and the front of the base is also provided with connecting block positioning bosses that match the two connecting block positioning recesses respectively.

[0009] Preferably, the guide plate has two threaded holes on its reverse side, with the two threaded holes located near two opposite corners of the guide plate.

[0010] According to the above technical solution, the beneficial effects of the present invention are:

[0011] In this invention, the guide plate and limiting plate are prevented from separating by connecting screws, and can slide relative to each other by adjusting the screws. The guide plate is detachably connected to the base via multiple connecting blocks. Before welding, the guide plate and limiting plate are removed from the base. The aluminum substrate is placed into the aluminum substrate mounting slot, and then the guide plate and limiting plate are aligned, with the front of the guide plate facing down and the back of the limiting plate facing up. At this point, the large-diameter ends of the pin through holes and pin stepped holes are aligned. Multiple adapter pins are inserted into the multiple pin stepped holes from the multiple pin through holes. The small-diameter ends of the adapter pins fall into the small-diameter ends of the pin stepped holes until the stepped portion of the pin stepped hole contacts the stepped shoulder of the adapter pin. At this point, the large-diameter end of the adapter pin is completely inside the large-diameter end of the pin stepped hole. Then, the guide plate and limiting plate are adjusted to an interleaved state, and the front of the limiting plate will block the large-diameter end of the pin stepped hole. With the guide plate facing upwards and the limiting plate facing downwards, the adapter pins will fall due to gravity, with the larger diameter end of the adapter pin landing on the front of the limiting plate. The guide plate and limiting plate are then mounted onto the base via multiple connecting blocks. After readjusting the guide plate and limiting plate to their aligned positions, the adapter pins will continue to fall due to gravity, with the larger diameter end passing through the pin through-hole and landing on the soldering surface of the aluminum substrate. This ensures that the adapter pins are perpendicular to the soldering surface of the aluminum substrate. The back of the base is then placed on a reflow soldering machine, and the entire positioning fixture can be directly fed into the reflow soldering process. Therefore, this invention can simultaneously and vertically position multiple adapter pins on an aluminum-based circuit board, facilitating automated batch soldering via reflow soldering equipment. It is simple to operate, has low implementation costs, and can automate the production process. The verticality of the adapter pins on the aluminum-based circuit board is high, resulting in high production efficiency. Attached Figure Description

[0012] Figure 1This is a schematic diagram showing the adapter pins in the extended position on the positioning fixture.

[0013] Figure 2 This is a schematic diagram showing the adapter pin in its falling position on the positioning fixture;

[0014] Figure 3 This is a schematic diagram of the base;

[0015] Figure 4 This is a front view of the guide plate;

[0016] Figure 5 This is a schematic diagram of the reverse side of the guide plate;

[0017] Figure 6 This is a front view of the limiting plate;

[0018] Figure 7 A frontal view of the guide plate and the limiting plate in the aligned state;

[0019] Figure 8 for Figure 7 The AA cross-sectional view has been modified and an adapter pin has been added;

[0020] Figure 9 A frontal view of the guide plate and the limiting plate in an interlaced state;

[0021] Figure 10 for Figure 9 The BB cross-sectional view was added and an adapter pin was added.

[0022] The markings in the diagram are: 1. Base, 2. Aluminum substrate, 3. Guide plate, 4. Limiting plate, 5. Adjusting screw, 6. Adapter pin, 7. Aluminum substrate mounting groove, 8. Connecting block positioning through hole, 9. Connecting block positioning boss, 10. Pin stepped hole, 11. Connecting block, 12. Connecting block positioning protrusion, 13. Connecting block positioning recess, 14. Connecting threaded hole, 15. Pin through hole, 16. Connecting block groove, 17. Connecting screw groove. Detailed Implementation

[0023] Referring to the attached diagram, the specific implementation method is as follows:

[0024] A reflow soldering positioning fixture for vertical adapter pins on an aluminum-based circuit board is used to position multiple adapter pins 6 on the soldering surface of an aluminum substrate 2. The adapter pins 6 applicable to this invention are stepped cylinders. The large-diameter end of the adapter pin 6 is used to be placed on the soldering surface of the aluminum substrate 2 for soldering, and the length direction of the adapter pin 6 is perpendicular to the soldering surface.

[0025] like Figure 1 , 2As shown, the positioning fixture includes a base 1, a guide plate 3, and a limiting plate 4. The base 1, guide plate 3, and limiting plate 4 are parallel to each other in their length directions. The limiting plate 4 is located between the base 1 and the guide plate 3. The back of the base 1 can be placed on a reflow soldering device. The front of the base 1 has an aluminum substrate mounting groove 7. The aluminum substrate 2 can be placed horizontally in the aluminum substrate mounting groove 7, with the welding surface of the aluminum substrate 2 facing the back of the limiting plate 4.

[0026] The front of the limiting plate 4 slides against the back of the guide plate 3. The back of the guide plate 3 has multiple connecting blocks 11 and multiple threaded holes 14. The limiting plate 4 has multiple connecting block slots 16 and multiple connecting screw slots 17. The connecting blocks 11 pass through the connecting block slots 16, and are detachably connected to the front of the base 1. Connecting screws are screwed into the threaded holes 14 and pass through the connecting screw slots 17. The screw heads contact the back of the limiting plate 4, thus preventing the front of the limiting plate 4 from separating from the back of the guide plate 3. An adjusting screw 5 passes through the side of the limiting plate 4. One end of the adjusting screw 5 rests against the side of the guide plate 3. The length directions of the connecting block slots 16 and the connecting screw slots 17 are parallel to the length direction of the adjusting screw 5, allowing the adjusting screw 5 to push the guide plate 3 relative to the limiting plate 4.

[0027] The guide plate 3 has multiple pin stepped holes 10, and the limiting plate 4 has multiple pin through holes 15. When multiple connecting blocks 11 cooperate to support the guide plate 3 and the limiting plate 4 on the front side of the base 1, the pin stepped holes 10 and the pin through holes 15 are both perpendicular to the welding surface of the aluminum substrate 2. The small diameter end opening of the pin stepped hole 10 is located on the front side of the guide plate 3, and the large diameter end opening of the pin stepped hole 10 is located on the back side of the guide plate 3. The small diameter end diameter of the pin stepped hole 10 matches the small diameter end diameter of the adapter pin 6. The large diameter end diameter of the pin stepped hole 10 and the diameter of the pin through hole 15 both match the large diameter end diameter of the adapter pin 6.

[0028] When the guide plate 3 and the limiting plate 4 are aligned, the large diameter ends of the multiple pin through holes 15 and the multiple pin stepped holes 10 can be aligned one by one, so that the adapter pin 6 can pass through the pin through hole 15 and enter the pin stepped hole 10. When the small diameter end of the adapter pin 6 passes through the small diameter end of the pin stepped hole 10, and the stepped part of the pin stepped hole 10 contacts the stepped shoulder of the adapter pin 6, the large diameter end of the adapter pin 6 is completely located inside the large diameter end of the pin stepped hole 10. When the guide plate 3 and the limiting plate 4 are staggered, the front of the limiting plate 4 can simultaneously block the large diameter ends of the multiple pin stepped holes 10.

[0029] In this embodiment, both the guide plate 3 and the limiting plate 4 are rectangular plates. The limiting plate 4 has bent plates on both sides along its width for screwing in the adjusting screws 5. The length directions of the connecting block groove 16 and the connecting screw groove 17 are parallel to the width direction of the limiting plate 4. The reverse side of the guide plate 3 has four cylindrical connecting blocks 11, located near the four corners of the guide plate 3. The ends of two connecting blocks 11 at one set of diagonal positions have connecting block positioning protrusions 12, and the ends of the other two connecting blocks 11 at the other set of diagonal positions have connecting block positioning recesses 13. The front side of the base 1 has connecting block positioning through holes 8 that match the two connecting block positioning protrusions 12, and the front side of the base 1 also has connecting block positioning bosses 9 that match the two connecting block positioning recesses 13. The reverse side of the guide plate 3 has two connecting threaded holes 14, located near two opposite corners of the guide plate 3.

[0030] Working process: Before welding, remove the guide plate 3 and the limiting plate 4 from the base 1. Place the aluminum substrate 2 into the aluminum substrate mounting slot 7. Then, adjust the guide plate 3 and the limiting plate 4 to be aligned, with the front of the guide plate 3 facing down and the back of the limiting plate 4 facing up. At this time, the large diameter ends of the pin through holes 15 and the pin stepped holes 10 are aligned. Insert multiple adapter pins 6 into the multiple pin stepped holes 10 through the multiple pin through holes 15. The small diameter end of the adapter pin 6 will fall into the small diameter end of the pin stepped hole 10 until the stepped part of the pin stepped hole 10 contacts the stepped shoulder of the adapter pin 6. At this time, the large diameter end of the adapter pin 6 is completely inside the large diameter end of the pin stepped hole 10. The state of the adapter pin 6 in the pin stepped hole 10 is as follows. Figure 8 As shown.

[0031] Then, adjust the guide plate 3 and the limiting plate 4 to an interleaved state. The front of the limiting plate 4 will block the large-diameter end of the pin stepped hole 10. Then, with the front of the guide plate 3 facing upwards and the back of the limiting plate 4 facing downwards, the adapter pin 6 will fall due to gravity, and the large-diameter end of the adapter pin 6 will fall onto the front of the limiting plate 4. At this time, the state of the adapter pin 6 within the pin stepped hole 10 is as follows. Figure 10 As shown.

[0032] Then, guide plate 3 and limit plate 4 are installed on base 1 through multiple connecting blocks 11. Guide plate 3 and limit plate 4 are readjusted to the alignment state. Due to gravity, the adapter pin 6 will continue to fall. The large diameter end of the adapter pin 6 will pass through the pin through hole 15 and fall onto the welding surface of aluminum substrate 2. It can be ensured that the adapter pin 6 and the welding surface of aluminum substrate 2 are perpendicular to each other. At this time, the reverse side of base 1 is placed on the reflow soldering equipment. The entire positioning fixture can be directly fed into the reflow soldering equipment, and batch automated soldering can be performed through the reflow soldering equipment.

Claims

1. A reflow soldering positioning fixture for vertical adapter pins on an aluminum-based circuit board, used to position multiple adapter pins (6) on the soldering surface of an aluminum substrate (2), wherein the adapter pins (6) are stepped cylinders, the large-diameter end of the adapter pins (6) is used to be placed on the soldering surface of the aluminum substrate (2) for soldering, and ensuring that the length direction of the adapter pins (6) is perpendicular to the soldering surface, characterized in that: The positioning fixture includes a base (1), a guide plate (3), and a limiting plate (4). The base (1), guide plate (3), and limiting plate (4) are parallel in length. The limiting plate (4) is located between the base (1) and the guide plate (3). The back of the base (1) can be placed on a reflow soldering device. The front of the base (1) has an aluminum substrate mounting groove (7). The aluminum substrate (2) can be placed horizontally in the aluminum substrate mounting groove (7) with the welding surface of the aluminum substrate (2) facing the back of the limiting plate (4). The front of the limiting plate (4) slides against the back of the guide plate (3). The back of the guide plate (3) has multiple connecting blocks (11) and multiple connecting threaded holes (14). The limiting plate (4) has multiple connecting block slots (16) and multiple connecting screw slots (17). Multiple connecting blocks (11) pass through multiple connecting block slots (16) respectively. The connecting blocks (11) are detachably connected to the front of the base (1). Multiple connecting threaded holes (14) are screwed with connecting screws respectively. Multiple connecting screws are inserted into multiple connecting screw slots (17). The screw head of the connecting screw contacts the back of the limiting plate (4), thereby restricting the separation of the front of the limiting plate (4) from the back of the guide plate (3). An adjusting screw (5) is inserted through the side of the limiting plate (4). One end of the adjusting screw (5) is abutted against the side of the guide plate (3). The length directions of the connecting block slots (16) and the connecting screw slots (17) are parallel to the length direction of the adjusting screw (5), so that the adjusting screw (5) can push the guide plate (3) to move relative to the limiting plate (4). Multiple pin stepped holes (10) are provided on the guide plate (3), and multiple pin through holes (15) are provided on the limiting plate (4). When multiple connecting blocks (11) cooperate to support the guide plate (3) and the limiting plate (4) on the front side of the base (1), the pin stepped holes (10) and pin through holes (15) are perpendicular to the welding surface of the aluminum substrate (2). The small diameter end opening of the pin stepped hole (10) is located on the front side of the guide plate (3), and the large diameter end opening of the pin stepped hole (10) is located on the back side of the guide plate (3). The small diameter end diameter of the pin stepped hole (10) matches the small diameter end diameter of the adapter pin (6). The large diameter end diameter of the pin stepped hole (10) and the diameter of the pin through hole (15) are both matched with the large diameter end diameter of the adapter pin (6). When the diameters match, the large diameter ends of multiple pin through holes (15) and multiple pin stepped holes (10) can be aligned one by one when the guide plate (3) and the limiting plate (4) are aligned, so that the adapter pin (6) can pass through the pin through hole (15) and enter the pin stepped hole (10). When the small diameter end of the adapter pin (6) passes through the small diameter end of the pin stepped hole (10) and the stepped part of the pin stepped hole (10) contacts the stepped shoulder of the adapter pin (6), the large diameter end of the adapter pin (6) is completely located inside the large diameter end of the pin stepped hole (10). When the guide plate (3) and the limiting plate (4) are staggered, the front of the limiting plate (4) can simultaneously block the large diameter ends of multiple pin stepped holes (10).

2. The reflow soldering positioning fixture for vertical adapter pins of an aluminum-based circuit board according to claim 1, characterized in that: The guide plate (3) and the limiting plate (4) are both rectangular plates. The limiting plate (4) has bent plates on both sides along the width direction for screwing in the adjusting screw (5). The length direction of the connecting block groove (16) and the connecting screw groove (17) are parallel to the width direction of the limiting plate (4).

3. The reflow soldering positioning fixture for vertical adapter pins of an aluminum-based circuit board according to claim 2, characterized in that: The guide plate (3) has four cylindrical connecting blocks (11) on its reverse side, and the four connecting blocks (11) are located close to the four corners of the guide plate (3).

4. The reflow soldering positioning fixture for vertical adapter pins of an aluminum-based circuit board according to claim 3, characterized in that: The ends of two connecting blocks (11) located at a diagonal position are provided with connecting block positioning protrusions (12), and the ends of two connecting blocks (11) located at another diagonal position are provided with connecting block positioning recesses (13). The front of the base (1) is provided with connecting block positioning through holes (8) that match the two connecting block positioning protrusions (12) respectively. The front of the base (1) is also provided with connecting block positioning bosses (9) that match the two connecting block positioning recesses (13) respectively.

5. The reflow soldering positioning fixture for vertical adapter pins of an aluminum-based circuit board according to claim 2, characterized in that: Two threaded holes (14) are provided on the reverse side of the guide plate (3), and the two threaded holes (14) are located near the two diagonal positions of the guide plate (3).

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