Mini LED-PCB front bonding pad roller tin brushing system and method

Abstract

The invention relates to the technical field of semiconductor welding, in particular to a Mini LED-PCB front face bonding pad roller tin brushing system and method. The automatic tin pick-up machine comprises a tin pick-up pool assembly, a roller assembly, a solder paste scraper assembly and a PCB which are sequentially arranged from bottom to top. The roller assembly drives the roller with the spring tin pick-up needle and the protector attached to the surface to rotate, the spring tin pick-up needle dips tin paste, the tin paste scraper assembly scrapes redundant tin paste, the PCB transversely moves, and the solder paste is evenly coated on a bonding pad through the difference between the stretching amount of the spring tin pick-up needle and the height of the protector. By means of the roller type tin brushing mode, the tin brushing problem of the Mini LED lamp bead surface is focused, the tin brushing stability and efficiency are improved, the related problems of a steel mesh are avoided, tin dispensing stability is ensured, redundant tin paste is avoided, the tin brushing yield is finally achieved, the product performance stability is improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor soldering technology, specifically to a MiniLED-PCB front pad tinning system and method. Background Technology

[0002] With the continuous development of display technology, MiniLEDs have been widely used in many display products due to their advantages such as high brightness, high contrast, and low power consumption. In the MiniLED production process, solder bonding is a crucial step. Those skilled in the art have continuously explored this technology; for example, Chinese Patent Publication No. CN119816012A discloses an optical inspection and rework system and method for MiniLED chips after solder bonding. However, currently, this process generally uses squeegee stencil printing, which suffers from problems such as inaccurate printing position, surface impurities, stencil expansion / contraction, hole blockage, and short lifespan, seriously affecting product yield and performance. Existing solutions often fail to simultaneously meet the demands of efficient and high-quality production. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a MiniLED-PCB front pad soldering roller system and method. The roller assembly drives the roller with spring soldering needles and protectors attached to its surface to rotate, so that the spring soldering needles can pick up solder paste, and then the excess solder paste is scraped off by the solder paste scraper assembly. With the lateral movement of the PCB board, the solder paste is evenly coated on the pads by utilizing the extension and retraction of the spring soldering needles and the height difference of the protector.

[0004] The technical solution adopted in this invention is as follows: A MiniLED-PCB front pad soldering roller system includes the following components arranged from bottom to top: The solder bath assembly is a groove with an open top, which contains solder paste; The roller assembly is placed horizontally above the solder bath assembly. The surface of the roller is covered with spring solder needles and protectors spaced between the spring solder needles. The roller drives the spring solder needles to rotate, and solder paste is applied to the spring solder needles. The protectors are used for positioning the roller and protecting the solder needles. Solder paste scraper assembly is fixed to the side of roller assembly. Its scraper is in contact with spring soldering needle. The scraper is used to scrape off excess solder paste on the spring soldering needle and recycle it. The PCB board moves laterally above the roller assembly, and its lower surface is machined with pads that mate with solder paste; the solder paste is evenly coated on the pads by the extension and retraction of the spring-loaded soldering pins and the height difference of the protector.

[0005] This technical solution addresses the soldering issue of MiniLED LED chips by employing a roller-type soldering method. It improves soldering stability and efficiency, avoids stencil-related problems, ensures stable soldering with no excess solder paste, and ultimately enhances soldering yield, product performance stability, and reduces production costs. Specifically, the rotating roller assembly drives the spring-loaded soldering needles to pick up solder paste from the solder bath assembly. The solder paste scraper assembly removes excess solder paste, ensuring the spring-loaded needles have the appropriate amount of solder paste on them. The PCB board moves laterally above the roller assembly, and the spring-loaded needles, utilizing their extension and retraction relative to the height difference of the protector, evenly coat the solder pads with solder paste, achieving precise soldering.

[0006] In addition, the MiniLED-PCB front pad roller soldering system proposed above according to the present invention may also have the following additional technical features: According to one embodiment of the present invention, the middle part of the roller is mounted between the solder bath assembly and the PCB board via a roller shaft. The length of the roller is greater than the width of the PCB board, and the spring-loaded soldering pins on the roller completely cover the solder pad area of ​​the PCB board.

[0007] In this technical solution, when the roller rotates, the spring-loaded soldering needles, due to their own elasticity and adhesion to the solder paste, can evenly pick up the solder paste in the soldering pool assembly. When rotating above the PCB board, thanks to the advantage of complete coverage, it ensures that each pad area can contact the spring-loaded soldering needles, thereby achieving efficient and uniform transfer of solder paste from the roller to the pads and completing the soldering process.

[0008] According to one embodiment of the present invention, the spring-loaded soldering pin includes the following structure: Mounting slots are spaced apart on the surface of the roller; The spring is located inside the mounting slot; The ejector pin has one end spring-loaded and is positioned on the mounting slot, while the other end is coated with solder paste. The spring and the ejector pin form a convex roller structure. The spring applies a preload force to the ejector pin to ensure the amount of expansion and contraction of the ejector pin in contact with the solder pad and to prevent the stencil from clogging the holes.

[0009] In this technical solution, mounting slots are arranged at intervals on the surface of the roller to form a positioning frame. The internal springs apply a preload force to the ejector pins through elastic deformation, making the ejector pins form a retractable "convex roller" structure. When the ejector pins contact the solder pads, the spring compression controls the expansion and contraction, ensuring uniform adhesion of solder paste. At the same time, the expansion and contraction characteristics of the ejector pins can automatically adapt to the height difference of the solder pads, avoiding poor solder paste coating caused by hole blockage in traditional stencils, and achieving precise soldering.

[0010] According to one embodiment of the present invention, the scraper is fixed in the tangential direction of the spring soldering needle by an adjustable bracket. The installation position of the scraper depends on the rotation direction of the roller assembly: it is located on the left side when rotating clockwise and on the right side when rotating counterclockwise. The length of the scraper is greater than the length of the roller, and its blade is set towards the rotation direction of the roller assembly.

[0011] In this technical solution, the adjustable bracket provides flexibility in adjusting the position and angle of the scraper to adapt to different working conditions; the scraper installation position changes with the rotation direction of the roller, which is achieved by balancing the centrifugal force generated by the rotation with the force exerted by the scraper on the solder paste; the scraper length is greater than the roller length, which can fully cover the solder-coated area on the roller surface; the blade faces the rotation direction, which can use the kinetic energy of the roller rotation to make the scraper more effectively remove excess solder paste when it contacts the spring soldering needle, ensuring that the amount of solder paste on the spring soldering needle is moderate and uniform.

[0012] According to one embodiment of the present invention, the PCB board rotates synchronously relative to the rotating roller assembly via a clamping device, and the solder pads on the PCB board come into contact with the spring soldering pins on the roller in sequence.

[0013] In this technical solution, the relative rotation design allows the soldering process to proceed continuously, reducing manual operation and waiting time, and significantly improving soldering efficiency.

[0014] To achieve the above objectives, the present invention also provides a method for applying solder to the front pads of a MiniLED-PCB using a roller.

[0015] A method for applying solder to the front pads of a MiniLED-PCB using a roller includes the following steps: On the MiniLED production line, a soldering operation is required before die bonding; After the PCB board is in place, the roller assembly is positioned by the protector to ensure that the soldering pins correspond to the solder pads; The spring-loaded soldering needle completes the soldering action in the solder bath assembly, and the amount of solder paste is controlled by the solder bath assembly. After the solder paste is applied, the solder paste scraper assembly controls the amount of solder paste and recycles any excess solder paste. After the spring-loaded soldering pin controls the amount of solder through the solder paste scraper assembly, it comes to the bottom of the PCB board pads and uses the extension and retraction of the spring-loaded soldering pin and the height difference of the protector to evenly apply the solder paste to the PCB board pads. After the solder paste is applied, the roller assembly detaches from the PCB board, and the PCB board flows out to the next process. The roller assembly is repositioned and soldered again by the protector. The soldering process is repeated after the next PCB board arrives.

[0016] This technical solution incorporates a soldering operation before die bonding in the MiniLED production line. First, a protector positions the roller assembly next to the PCB board, ensuring precise alignment of the soldering needles with the pads. Next, the spring-loaded soldering needles complete the soldering process in the solder bath assembly, which initially controls the amount of solder paste. Then, a solder paste scraper assembly further controls the amount of solder and recovers excess paste. Following this, the extension and retraction of the spring-loaded soldering needles, combined with the height difference between the protector and the PCB board, evenly distributes the controlled amount of solder paste onto the pads. Finally, the soldered roller assembly detaches from the PCB board, which then flows into the next process. The roller assembly is repositioned by the protector for soldering, and the process repeats once the next PCB board arrives. This achieves an efficient, precise, and recyclable soldering operation.

[0017] Compared with the prior art, the present invention has the following advantages: (1) High soldering yield: The roller soldering method is adopted. The spring soldering needle completely covers the pad area. By utilizing its extension and contraction and the height difference of the protector, the solder paste can be evenly and accurately applied to the pad, which significantly improves the soldering yield. (2) Improved stability: The roller drives the spring-loaded soldering needle to rotate and brush solder, which is more efficient than the stencil brushing mode and can avoid the problems of poor soldering caused by stencil expansion and contraction and hole blockage, thus ensuring the stability of soldering and improving the stability of product performance. (3) Cost reduction: It effectively avoids component wear caused by stencil problems, improves the service life of machine printing parts, and reduces the production of defective products, thereby effectively reducing production costs. Attached Figure Description

[0018] Figure 1 This is a side view of the present invention.

[0019] Figure 2 This is a top view of the present invention.

[0020] Figure 3 This is a flowchart illustrating the principle of the present invention.

[0021] In the diagram: 1. Solder bath assembly; 2. Roller assembly; 21. Spring soldering pin; 22. Protector; 3. Solder paste scraper assembly; 4. PCB board. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 like Figures 1 to 2 As shown, this embodiment provides a MiniLED-PCB front pad soldering roller system, including the following components arranged sequentially from bottom to top: Soldering pool assembly 1 is a groove with an open top, which contains solder paste; The roller assembly 2 is placed horizontally above the solder bath assembly 1. The surface of the roller is attached with spring solder needles 21 and protectors 22 are spaced apart between the spring solder needles 21. The roller drives the spring solder needles 21 to rotate, and solder paste is attached to the spring solder needles 21. The protectors 22 are used for positioning the roller and protecting the solder needles. Solder paste scraper assembly 3 is fixed to the side of roller assembly 2. Its scraper is in contact with spring soldering needle 21. The scraper is used to scrape off excess solder paste on spring soldering needle 21 and recycle it. PCB board 4 moves laterally above roller assembly 2, and its lower surface is processed with pads that mate with solder paste; solder paste is evenly coated on the pads by the extension and retraction of spring soldering pin 21 and the height difference of protector 22.

[0024] like Figures 1 to 2 As shown, this technical solution addresses the soldering issue of MiniLED LED beads through a roller-type soldering method, improving soldering stability and efficiency, avoiding stencil-related problems, ensuring stable soldering without excess solder paste, and ultimately improving soldering yield, product performance stability, and reducing production costs. Specifically, the roller assembly 2 rotates, driving the spring-loaded soldering needle 21 to pick up solder paste from the soldering bath assembly 1; the solder paste scraper assembly 3 removes excess solder paste, ensuring an appropriate amount of solder paste on the spring-loaded soldering needle 21; the PCB board 4 moves laterally above the roller assembly 2, and the spring-loaded soldering needle 21, utilizing its extension and retraction and the height difference with the protector 22, evenly coats the solder paste onto the pads, achieving precise soldering.

[0025] In addition, the MiniLED-PCB front pad roller soldering system proposed above according to the present invention may also have the following additional technical features: According to one embodiment of the present invention, the middle part of the roller is mounted between the solder bath assembly 1 and the PCB board 4 via a roller shaft. The length of the roller is greater than the width of the PCB board 4, and the spring-loaded soldering pins 21 on the roller completely cover the solder pad area of ​​the PCB board 4.

[0026] In this technical solution, when the roller rotates, the spring-loaded soldering needle 21 can evenly pick up the solder paste in the soldering pool assembly 1 due to its own elasticity and adhesion to the solder paste. When it rotates above the PCB board 4, it can ensure that each pad area can contact the spring-loaded soldering needle 21 due to its complete coverage, thereby realizing the efficient and uniform transfer of solder paste from the roller to the pad and completing the soldering process.

[0027] According to one embodiment of the present invention, the spring-loaded soldering pin 21 includes the following structure: Mounting slots are spaced apart on the surface of the roller; The spring is located inside the mounting slot; The ejector pin has one end spring-loaded and is positioned on the mounting slot, while the other end is coated with solder paste. The spring and the ejector pin form a convex roller structure. The spring applies a preload force to the ejector pin to ensure the amount of expansion and contraction of the ejector pin in contact with the solder pad and to prevent the stencil from clogging the holes.

[0028] In this technical solution, mounting slots are arranged at intervals on the surface of the roller to form a positioning frame. The internal springs apply a preload force to the ejector pins through elastic deformation, making the ejector pins form a retractable "convex roller" structure. When the ejector pins contact the solder pads, the spring compression controls the expansion and contraction, ensuring uniform adhesion of solder paste. At the same time, the expansion and contraction characteristics of the ejector pins can automatically adapt to the height difference of the solder pads, avoiding poor solder paste coating caused by hole blockage in traditional stencils, and achieving precise soldering.

[0029] According to one embodiment of the present invention, the scraper is fixed in the tangential direction of the spring soldering pin 21 by an adjustable bracket. The installation position of the scraper depends on the rotation direction of the roller assembly 2: it is located on the left side when rotating clockwise and on the right side when rotating counterclockwise. The length of the scraper is greater than the length of the roller, and its blade is set towards the rotation direction of the roller assembly 2.

[0030] In this technical solution, the adjustable bracket provides flexibility in adjusting the position and angle of the scraper to adapt to different working conditions; the scraper installation position changes with the rotation direction of the roller, which is achieved by balancing the centrifugal force generated by the rotation with the force exerted by the scraper on the solder paste; the scraper length is greater than the roller length, which can fully cover the solder-coated area on the roller surface; the blade faces the rotation direction, which can use the kinetic energy of the roller rotation to make the scraper more effectively remove excess solder paste when it contacts the spring soldering pin 21, ensuring that the amount of solder paste on the spring soldering pin 21 is moderate and uniform.

[0031] According to one embodiment of the present invention, the PCB board 4 rotates synchronously relative to the rotating roller assembly 2 via a clamping device, and the solder pads on it come into contact with the spring soldering pins 21 on the roller in sequence.

[0032] In this technical solution, the relative rotation design allows the soldering process to proceed continuously, reducing manual operation and waiting time, and significantly improving soldering efficiency.

[0033] Example 2 Based on Example 1, such as Figure 3 As shown, this embodiment provides a method for applying solder to the front pads of a MiniLED-PCB using a roller, including the following steps: On the MiniLED production line, a soldering operation is required before die bonding; After the PCB board 4 is in place, the roller assembly 2 is positioned by the protector 22 to ensure that the soldering pins correspond to the solder pads; The spring-loaded soldering needle 21 completes the soldering action in the soldering bath assembly 1, and the amount of solder paste is controlled by the soldering bath assembly 1. After the solder paste is applied, the solder paste scraper assembly 3 controls the amount of solder paste and recovers any excess solder paste. After the spring-loaded soldering pin 21 controls the amount of solder through the solder paste scraper assembly 3, it comes to the bottom of the pads on the PCB board 4. The extension and retraction of the spring-loaded soldering pin 21 and the height difference between the protector 22 are used to evenly apply the solder paste to the pads on the PCB board 4. After the solder paste is applied, the roller assembly 2 separates from the PCB board 4, and the PCB board 4 flows out to the next process. The roller assembly 2 is repositioned and soldered again by the protector 22. After the next PCB board 4 arrives, the roller repeats the soldering process.

[0034] This technical solution incorporates a soldering operation before die bonding in the MiniLED production line. First, the protector 22 positions the roller assembly 2 next to the PCB board 4, ensuring the soldering needles precisely align with the pads. Next, the spring-loaded soldering needles 21 complete soldering in the solder bath assembly 1, with the amount of solder paste initially controlled by the assembly. Then, the solder paste scraper assembly 3 further controls the amount of solder and recovers excess solder paste. Afterward, the controlled amount of solder paste is evenly applied to the pads of the PCB board 4 by utilizing the extension and retraction of the spring-loaded soldering needles 21 and the height difference between the protector 22 and the roller assembly 2. Finally, the soldered roller assembly 2 detaches from the PCB board 4, and the PCB board 4 flows into the next process. The roller assembly 2 is repositioned by the protector 22 for soldering, and the process is repeated once the next PCB board 4 arrives. This achieves an efficient, precise, and recyclable soldering operation.

[0035] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A MiniLED-PCB front pad soldering roller system, characterized in that, The components are arranged from bottom to top as follows: The soldering pool assembly (1) is a groove with an open top, which contains solder paste; The roller assembly (2) is placed horizontally above the solder bath assembly (1). The surface of the roller is attached with spring solder needles (21) and protectors (22) spaced between the spring solder needles (21). The roller drives the spring solder needles (21) to rotate. Solder paste is attached to the spring solder needles (21). The protectors (22) are used for positioning the roller and protecting the solder needles. Solder paste scraper assembly (3) is fixed to the side of roller assembly (2). Its scraper is in contact with spring soldering needle (21). The scraper is used to scrape off excess solder paste on spring soldering needle (21) and recycle it. The PCB board (4) is moved laterally to the top of the roller assembly (2), and its lower surface is processed with pads that match the solder paste; the solder paste is evenly coated on the pads by the extension and retraction of the spring soldering pin (21) and the height difference of the protector (22).

2. The MiniLED-PCB front pad soldering roller system as described in claim 1, characterized in that, The middle part of the roller is mounted between the solder bath assembly (1) and the PCB board (4) via a roller frame.

3. The MiniLED-PCB front pad soldering roller system as described in claim 1, characterized in that, The length of the roller is greater than the width of the PCB board (4), and the spring-loaded soldering pins (21) on it completely cover the solder pad area of ​​the PCB board (4).

4. The MiniLED-PCB front pad soldering roller system as described in claim 1, characterized in that, The spring soldering needle (21) includes the following structure: Mounting slots are spaced apart on the surface of the roller; The spring is located inside the mounting slot; The ejector pin has one end spring-loaded and is positioned on the mounting slot, while the other end is coated with solder paste. The spring and the ejector pin form a convex roller structure. The spring applies a preload force to the ejector pin to ensure the amount of expansion and contraction of the ejector pin in contact with the solder pad and to prevent the stencil from clogging the holes.

5. The MiniLED-PCB front pad soldering roller tinning system as described in claim 1, characterized in that, The scraper is fixed in the tangential direction of the spring soldering needle (21) by an adjustable bracket.

6. The MiniLED-PCB front pad soldering roller system as described in claim 5, characterized in that, The installation position of the scraper depends on the rotation direction of the roller assembly (2): it is located on the left when rotating clockwise and on the right when rotating counterclockwise.

7. The MiniLED-PCB front pad soldering roller system as described in claim 6, characterized in that, The length of the scraper is greater than the length of the drum, and its blade is set in the direction of rotation of the drum assembly (2).

8. The MiniLED-PCB front pad soldering roller system as described in claim 1, characterized in that, The PCB board (4) rotates synchronously with the rotating roller assembly (2) through the clamping device, and the solder pads on it come into contact with the spring soldering pins (21) on the roller in sequence.

9. A method for applying solder to the front pads of a MiniLED-PCB using a roller, comprising the MiniLED-PCB front pad soldering system as described in any one of claims 1-8, characterized in that, Includes the following steps: On the MiniLED production line, a soldering operation is required before die bonding; After the PCB board (4) is in place, the roller assembly (2) is positioned by the protector (22) to ensure that the soldering pins correspond to the solder pads; The spring-loaded soldering needle (21) completes the soldering action in the soldering pool assembly (1), and the amount of solder paste is controlled by the soldering pool assembly (1); After the solder paste is applied, the solder paste scraper assembly (3) controls the amount of solder paste again and recycles the excess solder paste. After the spring-loaded soldering needle (21) controls the amount of solder through the solder paste scraper assembly (3), it comes to the pads of the PCB board (4) and uses the extension and retraction of the spring-loaded soldering needle (21) and the height difference of the protector (22) to evenly apply the solder paste to the pads of the PCB board (4). After the solder paste is applied, the roller assembly (2) separates from the PCB board (4), and the PCB board (4) flows out to the next process. The roller assembly (2) is repositioned and soldered by the protector (22). After the next PCB board (4) arrives, the roller repeats the soldering process.

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