Reflow soldering equipment for PCB (printed circuit board) processing

Abstract

The invention relates to the technical field of circuit board welding and printing equipment, and discloses reflow soldering equipment for PCB (printed circuit board) processing, which comprises a bracket, a positioning seat for positioning a circuit board body is fixedly arranged at the top of the bracket, a fixing plate is fixedly connected to the bottom of the positioning seat, and a fixing ring is fixedly connected to the top of the fixing plate in a sleeving manner. Solder paste on the side wall of the bottom end of the pin inserted into the electroplating through hole is scraped and reserved through the inner wall of the communicating hole in the fixing ring, and the solder paste which is communicated with the redundant pin and is difficult to flow back into the electroplating through hole subsequently is removed through the shearing mechanism, so that extra pollution of a reflow furnace caused by the solder paste of the part is avoided; the device has the advantages that the device is simple in structure and convenient to operate, sufficient solder paste in the electroplating through holes is guaranteed, subsequent secondary pin trimming is not needed, the elastic membrane is expanded to attach the scraped solder paste to the pins in cooperation with the adjusting mechanism and the shearing mechanism before shearing, the pins are fixed in cooperation, and stability of the trimming process and coating of sufficient solder paste on the pins are guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of circuit board soldering and printing equipment, and in particular to a reflow soldering equipment for PCB board processing. Background Art

[0002] Reflow soldering equipment utilizes surface mount technology (SMT) and through-hole reflow soldering to reliably connect through-hole and surface-mount components to PCBs (printed circuit boards). Existing reflow soldering equipment includes a solder paste coating mechanism, a placement mechanism, and a reflow oven. The coating mechanism applies solder paste around the electronic component placement locations and fills the PCB's through-holes. The placement mechanism then places the SMT components on the PCB and inserts the through-hole component pins into the corresponding through-holes. The PCB is then placed into the reflow oven's connection port using a transport mechanism. The PCB is heated by hot air in the reflow oven, melting the solder paste and volatilizing the additives. The solder paste around the through-hole component pins, including solder around the top surface and within the through-holes, flows back into the through-holes during heating, filling them and completing through-hole reflow soldering. After soldering, the PCB undergoes pin trimming to complete the PCB's soldering process.

[0003] However, when using traditional reflow soldering equipment, the insertion of the pins of through-hole components into the through-holes will carry the solder paste in the through-holes for too long a distance, and some of the solder paste in the through-holes will adhere to the sides and bottom of the pins to form a "match head" phenomenon, resulting in insufficient tin filling between the pins in the through-holes and the inner walls of the through-holes, which will increase the void rate of the through-holes during the reflow soldering process and cause cold soldering. In addition, the solder paste adhered to the bottom of the pins is easily melted by the hot air in the reflow oven and blown into the reflow oven, shortening the cleaning and maintenance cycle of the equipment during the through-hole reflow process, resulting in increased production costs. Summary of the Invention

[0004] The present application proposes a reflow soldering device for PCB board processing, which has the advantages of ensuring sufficient solder paste content in the through-hole and removing solder paste adhering to the pins, so as to solve the problem that the solder paste in the through-hole is easily carried out by the pins for a long distance, resulting in a shortage of solder in the through-hole and the solder paste is easily blown into the reflow oven by the airflow.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solution: a reflow soldering device for PCB board processing, comprising a bracket, a positioning seat for positioning the circuit board body is fixedly provided on the top of the bracket, a fixing plate is fixedly connected to the bottom of the positioning seat, a fixing ring is fixedly sleeved on the top of the fixing plate, and the number of the fixing rings is set to several, and the number and position of the fixing rings correspond to the number and position of the electroplated through holes.

[0006] A connecting hole is provided on the inner side of the fixing ring near the center, and the diameter of the connecting hole is adapted to the diameter of the pin. A shearing mechanism is provided on one side of the bracket, and the shearing mechanism is used to shear the pin after the corresponding through-hole component is mounted on the circuit board body.

[0007] Furthermore, an elastic diaphragm for guiding the pins to be inserted into the communicating holes is fixedly provided on the inner side of the fixing ring. The elastic diaphragm is an annular diaphragm and the cross section of the inner annular surface of the elastic diaphragm is arc-shaped.

[0008] During the process of inserting the pin into the connecting hole, the pin is guided by the arc-shaped annular surface of the elastic diaphragm, thereby ensuring the stability of the insertion process.

[0009] Furthermore, the inner curved surface of the elastic diaphragm is set as a solder paste coating, and the amount of solder paste coated on a single electroplated through hole is the remaining solder paste volume after removing the solder paste at the bottom of the pin to meet the requirements for filling the electroplated through hole in the subsequent welding process.

[0010] The amount of pre-coated solder paste is such that after removing the portion brought out by the bottom of the pin, it is sufficient to melt and fill the plated through-holes during the subsequent heating and soldering process.

[0011] Furthermore, the shearing mechanism includes a driving mechanism and a shearing head, and the driving mechanism is used to drive the shearing head to move.

[0012] Cooperate with the shearing mechanism to remove the solder paste at the bottom of the pin after separating the solder paste on the side wall of the pin, so as to prevent this part of the solder paste from participating in the subsequent welding process.

[0013] Furthermore, a support cavity is formed between the elastic diaphragm and the fixing ring, and an adjustment mechanism is provided on the inner side of the fixing ring. The adjustment mechanism can adjust the air pressure in the support cavity. After the pin is inserted into the connecting hole, the air pressure is increased to make the inner side of the elastic diaphragm close to the pin.

[0014] In conjunction with the shearing mechanism, the air pressure in the support chamber is increased before shearing to bring the elastic diaphragm close to the pin, so that the solder paste inside is attached to the pin at the electroplated through-hole position, ensuring the continuity of the solder paste and the solder paste in the electroplated through-hole, and the pressure between the elastic diaphragm and the pin ensures the stability of the pin in the subsequent shearing process.

[0015] Furthermore, the adjustment mechanism includes an adjustment ring, an annular adjustment cavity is opened in the fixed ring, the adjustment ring is slidably sleeved in the adjustment cavity, the adjustment ring is used to change the air pressure of the adjustment cavity located at the top cavity of the adjustment ring, and a connecting hole is opened on one side of the fixed ring, and the connecting hole is used to connect the support cavity and the adjustment cavity.

[0016] The air pressure in the regulating cavity is changed by moving the regulating ring, and the air pressure in the supporting cavity is adjusted in conjunction with the connecting hole.

[0017] Furthermore, a movable ring is fixedly connected to the bottom of the adjustment ring, a return spring is movably provided in the adjustment cavity, and one side of the shearing head is provided with a wear-resistant block. The movable ring can cooperate with the wear-resistant block to drive the movable ring to shrink into the adjustment cavity before shearing.

[0018] Through the cooperation of the wear-resistant block and the moving ring, when the shearing head moves to the corresponding pin to be sheared, the moving ring moves to change the air pressure in the regulating chamber, so that the air pressure in the supporting chamber increases to cooperate with the shearing action.

[0019] Furthermore, a reflow furnace is fixedly provided on one side of the bracket, and a collection box is fixedly provided on the bottom of the bracket.

[0020] The reflow oven is used to perform the reflow soldering process on the circuit board after the patch is completed, and the collection box collects the cut pins and the solder paste attached to the cut pins.

[0021] The beneficial effects of the present invention are as follows:

[0022] The present application provides a reflow soldering device for PCB board processing, which scrapes the solder paste adhered to the side wall of the pin relative to the pin to the bottom of the electroplated through-hole through the inner wall of the connecting hole in the fixing ring, and uses a shearing mechanism to remove the solder paste at the bottom of the pin together with the pin of excess length, thereby ensuring a stable and sufficient amount of solder paste in the electroplated through-hole, eliminating the need to trim the pins of excess length on the subsequent circuit board body, and reducing the additional contamination caused by excessive solder paste in the electroplated through-hole brought out by the pins in the reflow oven. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only embodiments of the present invention. Those skilled in the art can also derive other drawings based on the provided drawings without inventive work.

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a structural diagram of the positioning seat of the present invention;

[0026] Figure 3 This is a schematic cross-sectional view of the structure of the fixing plate of the present invention;

[0027] Figure 4 For the present invention Figure 3 A schematic diagram of the structure enlargement at point A;

[0028] Figure 5 It is a schematic cross-sectional view of the structure of the top block of the present invention.

[0029] In the figure: 1- bracket, 2- positioning seat, 3- circuit board body, 4- through-hole component, 5- pin, 6- fixed plate, 7- fixed ring, 8- elastic diaphragm, 9- support cavity, 10- adjustment cavity, 11- adjustment ring, 12- moving ring, 13- reset spring, 14- electroplated through hole, 15- connecting hole, 16- driving mechanism, 17- cutting head, 18- reflow oven, 19- collection box, 20- wear-resistant block, 21- communicating hole. DETAILED DESCRIPTION

[0030] 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] Example 1, as Figure 1-Figure 5 , a reflow soldering equipment for PCB board processing, including a bracket 1, a positioning seat 2 for positioning the circuit board body 3 is fixedly provided on the top of the bracket 1, and the conveying mechanism of the reflow soldering equipment moves the circuit board body 3 after the corresponding area is coated with solder paste to the positioning seat 2, so that the position of the circuit board body 3 relative to the corresponding positioning seat 2 is fixed, and the pins 5 corresponding to the through-hole components 4 are used to be inserted into the electroplated through-holes 14 on the circuit board body 3. The amount of solder paste coated at the electroplated through-holes 14 meets the requirement that the volume of the tin material between the inner wall of the electroplated through-hole 14 and the pins 5 and the volume of the tin material located on the top surface of the circuit board body 3 around the top of the electroplated through-hole 14 after the volatilization of the additive is sufficient to fill the area between the electroplated through-hole 14 and the pins 5. The solder paste coated on the top surface of the circuit board body 3 around the top of the electroplated through-hole 14 avoids the position of the through-hole components 4 during coating to avoid the appearance of tin beads in the subsequent reflow soldering process, which affects the welding quality.

[0032] The patch mechanism of the reflow soldering equipment arranges the surface-mount components and through-hole components 4 to corresponding positions on the top of the circuit board body 3, wherein when the through-hole components 4 are arranged on the top surface of the circuit board body 3, the pins 5 pass through the corresponding electroplated through-holes 14, and a reflow oven 18 is fixedly provided on one side of the bracket 1. The conveying mechanism sends the circuit board body 3 with the mounted electronic components to the docking position of the reflow oven 18, so that the circuit board body 3 is driven by the conveying mechanism of the reflow oven 18 through the reflow oven 18, and the reflow oven 18 melts the solder paste on the circuit board body 3 by hot air, and the PCB is moved to the cooling component of the reflow oven 18 for cooling, completing the through-hole reflow soldering process of the circuit board body 3, and then the welding process of the circuit board body 3 is completed after the pins 5 are sheared.

[0033] The bottom of the positioning seat 2 is fixedly connected to a fixing plate 6, and the top surface of the fixing plate 6 is fitted with the bottom surface of the circuit board body 3 of the corresponding specification. A fixing ring 7 is fixedly sleeved on the top of the fixing plate 6. The number of fixing rings 7 is set to be several, and the number and position of the fixing rings 7 correspond to the number and position of the plated through holes 14. A connecting hole 21 is opened at the center of the inner side of the fixing ring 7. The axis of the connecting hole 21 is collinear with the axis of the plated through hole 14. The diameter of the connecting hole 21 is adapted to the diameter of the pin 5. When the patch mechanism mounts the through-hole component 4 to the top surface of the circuit board body 3, the pin 5 passes through the plated through hole 14 and then passes through the corresponding connecting hole 21. The inner wall of the connecting hole 21 fits with the pin 5, thereby scraping the solder paste adhered to the side wall of the pin 5 relative to the pin 5, so that the scraped solder paste is always located near the bottom of the plated through hole 14, avoiding the solder paste between the plated through hole 14 and the pin 5 being carried away too far by the pin 5, affecting the subsequent solder paste reflow.

[0034] A shearing mechanism is provided on one side of the bracket 1, and the shearing mechanism includes a driving mechanism 16 and a shearing head 17. The shearing mechanism is used to shear the pin 5 after the corresponding through-hole component 4 is mounted on the circuit board body 3. The driving mechanism 16 can be set as a robotic arm. The driving mechanism 16 is used to drive the shearing head 17 to move, so that the shearing head 17 moves to the bottom of the pin 5 to be trimmed. The shearing head 17 cuts off the pin 5 and removes the solder paste adhered to the bottom of the pin 5. At the same time, there is no need to trim the pin 5 subsequently, ensuring that the circuit board body 3 is in the reflow oven 18. Under the action of hot air, the solder paste adhered to the bottom of the pin 5 is prevented from being blown into the furnace body, resulting in an increased degree of contamination in the reflow oven 18, thereby extending the cleaning and maintenance cycle of the reflow oven 18 during the through-hole reflow soldering process, while ensuring the welding quality of the electroplated through hole 14 and reducing production costs.

[0035] An elastic diaphragm 8 is fixedly provided on the inner side of the fixing ring 7 for guiding the pin 5 to be inserted into the connecting hole 21. The elastic diaphragm 8 is an annular diaphragm and the cross-section of the inner annular surface of the elastic diaphragm 8 is arc-shaped. After the pin 5 passes through the electroplated through-hole 14, the pin 5 is guided to the connecting hole 21 to ensure the stability of the pin 5 insertion process. A collection box 19 is fixedly provided at the bottom of the bracket 1. The collection box 19 collects the waste after the pin 5 is cut, which is convenient for subsequent recycling. After removing the solder paste at the bottom of the pin 5, the amount of solder paste corresponding to the electroplated through-hole 14 and the pin 5 and the volume of solder paste around the top and bottom surfaces of the electroplated through-hole 14 are sufficient to fill the electroplated through-hole 14 during the subsequent welding process. The surface of the inner arc surface of the elastic diaphragm 8 is set to a solder paste-repellent coating. The solder paste-repellent coating can be set to a diamond-like coating to prevent the elastic diaphragm 8 from adhering to the solder paste.

[0036] Example 2, as Figure 2-Figure 5On the basis of the first embodiment, an annular adjustment cavity 10 is opened in the fixed ring 7, and an adjustment ring 11 is slidably sleeved in the adjustment cavity 10. The adjustment ring 11 is used to change the air pressure of the adjustment cavity 10 located at the top of the adjustment ring 11. A support cavity 9 is formed between the elastic diaphragm 8 and the fixed ring 7. A connecting hole 15 is opened on one side of the fixed ring 7. The connecting hole 15 is used to connect the support cavity 9 and the adjustment cavity 10. When the pin 5 is inserted into the connecting hole 21, the adjustment ring 11 is located at the bottom of the adjustment cavity 10. The arc surface of the elastic diaphragm 8 is used to guide the insertion action of the pin 5. The bottom of the adjustment ring 11 is fixedly connected to the movable ring 12. A reset spring 13 is movably provided in the adjustment cavity 10. Figure 5 One side of the shearing head 17 is provided with a wear-resistant block 20 .

[0037] When the shearing mechanism trims the pin 5, the driving mechanism 16 drives the shearing head 17 to move to the bottom of the pin 5 to be sheared. At this time, the wear-resistant block 20 presses against the moving ring 12, causing the moving ring 12 to shrink into the adjusting cavity 10. The movement of the moving ring 12 drives the adjusting ring 11 to move. The adjusting ring 11 compresses the adjusting cavity 10 at the top. The cavity of the adjusting cavity 10 is connected with the supporting cavity 9 through the connecting hole 15, so that the air pressure in the supporting cavity 9 increases with the increase of the air pressure in the adjusting cavity 10. The air pressure in the supporting cavity 9 makes the elastic diaphragm 8 further approach the pin 5, and re-applies the scraped solder paste on the inside to the outer wall of the pin 5, ensuring that the scraped solder paste is effectively in contact with the pin 5 near the electroplated through-hole 14. At the same time, part of the elastic diaphragm 8 fits with the pin 5 in conjunction with the connecting hole 21 to further fix the pin 5, ensuring that the position of the pin 5 is fixed during the shearing process of the pin 5, thereby improving the stability of the reflow soldering equipment.

[0038] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A reflow soldering device for PCB board processing, comprising a bracket (1), wherein a positioning seat (2) for positioning a circuit board body (3) is fixedly provided on the top of the bracket (1), characterized in that: The bottom of the positioning seat (2) is fixedly connected to a fixing plate (6), the top of the fixing plate (6) is fixedly sleeved with a fixing ring (7), the number of the fixing rings (7) is set to be several, and the number and position of the fixing rings (7) correspond to the number and position of the electroplated through holes (14); A connecting hole (21) is provided on the inner side of the fixing ring (7) near the center, and the diameter of the connecting hole (21) is adapted to the diameter of the pin (5). A shearing mechanism is provided on one side of the bracket (1), and the shearing mechanism is used to shear the pin (5) after the corresponding through-hole component (4) is mounted on the circuit board body (3).

2. The reflow soldering equipment for PCB board processing according to claim 1, characterized in that: An elastic diaphragm (8) for guiding the pin (5) to be inserted into the connecting hole (21) is fixedly provided on the inner side of the fixing ring (7). The elastic diaphragm (8) is an annular diaphragm, and the cross section of the inner annular surface of the elastic diaphragm (8) is arc-shaped.

3. The reflow soldering equipment for PCB board processing according to claim 2, characterized in that: The inner curved surface of the elastic diaphragm (8) is provided with a tin-repellent coating, and the amount of tin paste applied to each of the electroplated through holes (14) is the amount of tin paste remaining after removing the tin paste at the bottom of the pin (5) to satisfy the requirement for filling the electroplated through hole (14) during subsequent soldering.

4. The reflow soldering equipment for PCB board processing according to claim 2, characterized in that: The shearing mechanism comprises a driving mechanism (16) and a shearing head (17), wherein the driving mechanism (16) is used to drive the shearing head (17) to move.

5. The reflow soldering equipment for PCB board processing according to claim 4, characterized in that: A support cavity (9) is formed between the elastic diaphragm (8) and the fixing ring (7). An adjustment mechanism is provided on the inner side of the fixing ring (7). The adjustment mechanism is capable of adjusting the air pressure in the support cavity (9). After the pin (5) is inserted into the connecting hole (21), the air pressure is increased so that the inner side of the elastic diaphragm (8) is close to the pin (5).

6. The reflow soldering equipment for PCB board processing according to claim 5, characterized in that: The regulating mechanism comprises an regulating ring (11), an annular regulating cavity (10) is provided in the fixing ring (7), the regulating ring (11) is slidably sleeved in the regulating cavity (10), the regulating ring (11) is used to change the air pressure of the regulating cavity (10) located at the top cavity of the regulating ring (11), and a connecting hole (15) is provided on one side of the fixing ring (7), and the connecting hole (15) is used to connect the supporting cavity (9) and the regulating cavity (10).

7. The reflow soldering equipment for PCB board processing according to claim 6, characterized in that: The bottom of the adjusting ring (11) is fixedly connected to a movable ring (12), a return spring (13) is movably provided in the adjusting cavity (10), a wear-resistant block (20) is provided on one side of the shearing head (17), and the movable ring (12) can cooperate with the wear-resistant block (20) to drive the movable ring (12) to retract into the adjusting cavity (10) before shearing.

8. The reflow soldering equipment for PCB board processing according to claim 1, characterized in that: A reflow furnace (18) is fixedly provided on one side of the bracket (1), and a collection box (19) is fixedly provided on the bottom of the bracket (1).

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