Welding machine with upper preheating function and lower preheating function and circuit board welding method

Abstract

The invention relates to the technical field of circuit board welding, in particular to a welding machine with an upper preheating function and a lower preheating function and a circuit board welding method. The welding machine with the vertical preheating function comprises a conveying device, a scaling powder spraying device, a welding device, a first preheating device and a second preheating device. The conveying device is used for conveying circuit boards; the soldering flux spraying device and the welding device are arranged on the first side of the conveying device; the first preheating device is arranged on the first side of the motion trail of the circuit board, and the first preheating device comprises a first protective cover and a first heating body arranged in the first protective cover; the second preheating device is arranged on the second side of the circuit board motion trail; the second preheating device comprises a second protective cover, a second heating body arranged in the second protective cover and a diathermanous plate arranged on the second protective cover. And after the soldering flux is sprayed, the circuit board is preheated by the first preheating device and the second preheating device, so that the circuit board is at the optimal welding temperature, and the welding quality is better guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board welding, in particular to a welding machine with upper and lower preheating and a circuit board welding method. Background Art

[0002] Some components on the circuit board are fixed to the circuit board by welding. When welding the circuit board, the flux is usually sprayed first, and then the components are welded to the circuit board. There are circuit board welding equipment on the market, but some welding equipment usually welds after spraying the flux. In this welding method, there may be inconsistency between the temperature of the flux and the temperature of the circuit board, and the welding temperature is difficult to guarantee, so there may be problems of cold welding.

[0003] For example, China's patent application number: CN202120189816.9 circuit board assembly welding equipment specifically discloses "horizontally conveying PCBA boards and FPC boards through PCBA board horizontal conveyor lines and FPC board horizontal conveyor lines. Grab and place PCBA boards and FPC boards through a board grabbing mechanism, and apply flux to PCBA boards through a flux spraying mechanism. Determine the position of the circuit board through a visual photography correction mechanism. Weld the PCBA board and FPC board through a rotating table and a welder". This type of equipment performs welding after spraying the flux. There may be inconsistency between the temperature and the temperature of the circuit board, and the welding temperature is difficult to guarantee. Therefore, there may be problems with cold soldering.

[0004] Another example is the Chinese patent application number: CN201410475940.6 Circuit board welding device is invalid - annual fee has not been paid. Similarly, welding is performed after spraying the flux. The temperature and the temperature of the circuit board may be inconsistent, and the welding temperature is difficult to guarantee, so there may be a problem of cold soldering. Summary of the invention

[0005] In view of this, the present invention aims at the deficiencies in the prior art, and its main purpose is to provide a welding machine with upper and lower preheating, which is preheated after spraying flux, and then welding is performed after preheating. The welding temperature is controlled and the welding quality is more guaranteed, thereby overcoming the shortcomings of the prior art.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: The present application provides a welding machine with upper and lower preheating, comprising a conveying device, a flux spraying device, a welding device, a first preheating device, and a second preheating device; the conveying device is used to convey a circuit board; the flux spraying device and the welding device are arranged on a first side of the conveying device; the first preheating device is arranged on a first side of a movement track of the circuit board, the first preheating device comprises a first protective cover, and a first heating element arranged in the first protective cover; the second preheating device is arranged on a second side of the movement track of the circuit board; the second preheating device comprises a second protective cover, a second heating element arranged in the second protective cover, and a heat-transmitting plate arranged on the second protective cover.

[0007] Preferably, the conveying device includes a sliding module, a lifting module, and a carrier tooling; the lifting module is arranged on the sliding module; the carrier tooling is arranged on the lifting module; wherein the carrier tooling includes a carrier bracket, a carrier, an adjustment plate, and an adjustment member; the carrier is slidably arranged on the carrier bracket; the adjustment plate is adjustably arranged on the carrier, and the adjustment member is adjustably arranged on the adjustment plate; the adjustment member clamps the circuit board.

[0008] Preferably, the adjustment plate and the carrier are provided with a first narrow and long adjustment hole, and the first fastener fixes the adjustment plate to the carrier; the adjustment plate is provided with a second narrow and long adjustment hole, and the second fastener fastens the adjustment member to the adjustment plate; wherein the adjustment member is L-shaped.

[0009] Preferably, the flux spraying device comprises a flux box, a nozzle bracket, and a nozzle; the nozzle bracket is arranged in the flux box, and the nozzle is adjustably arranged in the nozzle bracket.

[0010] Preferably, the welding device includes a tin furnace, a nitrogen hood covering the tin furnace, and a solder head connected to the tin furnace; the nitrogen hood is provided with a heat dissipation fan for cooling the tin furnace; the solder head is covered with a reflow sleeve, and a reflow channel connected to the tin furnace is formed between the solder head and the reflow sleeve, so that the solder can flow back into the tin furnace.

[0011] Preferably, the interior of the solder head is a hollow structure, and the solder can be squeezed out of the hollow structure; a plurality of air holes are provided on the annular seat of the nitrogen cover, and the solder head passes through the annular seat, and nitrogen can be discharged from the air holes.

[0012] Preferably, the first preheating device further comprises a first lampshade arranged in the first protective cover, a first thermocouple thermometer arranged in the first lampshade, and a first air pipe arranged on the outside of the first heating element; the first air pipe can blow air toward the circuit board.

[0013] Preferably, the second preheating device further comprises a second lampshade arranged in the second protective cover and a second thermocouple thermometer arranged outside the heat-transmitting plate; wherein the second lampshade has a plurality of reflecting grooves, and the second heating element is arranged in the reflecting grooves.

[0014] Preferably, the first heating element is a resistive heating element, and the second heating element is an infrared lamp tube; the structure of the reflective groove is an isosceles trapezoidal shape.

[0015] The present application provides a circuit board welding method, including S1, loading, placing the circuit board into a conveying device; S2, spraying flux, the conveying device conveys the circuit board to the flux spraying device, and the flux spraying device sprays flux on the circuit board; S3, preheating the circuit board; after the circuit board is sprayed with flux, the conveying device conveys the circuit board between a first preheating device and a second preheating device, and the first preheating device and the second preheating device preheat the circuit board at the same time; S4, welding the circuit board; after the circuit board is preheated, the conveying device conveys the circuit board to the welding device, and the welding device welds the circuit board.

[0016] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that the conveying device is used to convey the circuit board, the flux spraying device sprays the flux on the circuit board, and the welding device welds the circuit board. The circuit board is clamped between the first preheating device and the second preheating device. After the flux is sprayed, the first preheating device and the second preheating device preheat the circuit board, so that the circuit board is at the optimal welding temperature, and the quality of welding is more guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an overall schematic diagram of an embodiment of the present invention.

[0018] Figure 2 The embodiment of the present invention Figure 1 Schematic diagram of some structures.

[0019] Figure 3 It is a schematic diagram of a flux spraying device and a welding device according to an embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of a conveying device according to an embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram of the decomposition of the second preheating device of an embodiment of the present invention.

[0022] Figure 6 It is a schematic diagram of the decomposition of the first preheating device of an embodiment of the present invention.

[0023] Figure 7 It is a schematic diagram of the exploded view of the carrier tooling according to an embodiment of the present invention.

[0024] Description of the accompanying drawings: 10. Conveying device; 11. Sliding module; 12. Lifting module; 110. Carrier tooling; 111. Carrier bracket; 112. Carrier; 113. Adjustment plate; 114. Adjustment member; 115. First fastener; 116. Second fastener; 20. Flux spraying device; 21. Flux box; 22. Nozzle bracket; 23. Nozzle; 30. Welding device; 31. Tin furnace; 32. Nitrogen hood; 33. Ring seat; 34. Air hole; 35. Solder head; 36. Cooling fan; 37. Reflow sleeve; 40. First preheating device; 41. First protective cover; 42. First lampshade; 43. First heating element; 44. First thermocouple thermometer; 45. First air pipe; 50. Second preheating device; 51. Second protective cover; 52. Second heating element; 53. Heat-transmitting plate; 54. Second thermocouple thermometer; 55. Reflection tank; 60. Circuit board. DETAILED DESCRIPTION

[0025] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0026] Embodiment 1 Please refer to Figures 1 to 7 As shown, it shows the specific structure of a preferred embodiment of the present invention, which is a welding machine with upper and lower preheating.

[0027] After the circuit board is sprayed with solder, the first preheating device 40 and the second preheating device 50 preheat the circuit board so that both the upper and lower surfaces of the circuit board 60 are heated, the welding quality is more guaranteed, and there is no problem of cold soldering.

[0028] The present application provides a welding machine with upper and lower preheating, including a conveying device 10, a flux spraying device 20, a welding device 30, a first preheating device 40, and a second preheating device 50; the conveying device 10 is used to convey a circuit board 60; the flux spraying device 20 and the welding device 30 are arranged at the lower side of the conveying device 10; the first preheating device 40 is arranged at the first side of the movement track of the circuit board 60, and the first preheating device 40 includes a first protective cover 41 and a first heating element 43 arranged in the first protective cover 41; the second preheating device 50 is arranged at the second side of the movement track of the circuit board 60; the second preheating device 50 includes a second protective cover 51, a second heating element 52 arranged in the second protective cover 51, and a heat-transmitting plate 53 arranged on the second protective cover 51. The conveying device 10 is used to convey the circuit board 60, the flux spraying device 20 is used to spray flux on the circuit board 60, and the welding device 30 is used to weld the circuit board 60. The first preheating device 40 and the second preheating device 50 are used to preheat the circuit board 60. The first preheating device 40 and the second preheating device 50 are arranged at intervals. The first preheating device 40 preheats the top surface of the circuit board 60, and the second preheating device 50 preheats the bottom surface of the circuit board 60, so that the welding quality is more guaranteed. During production, 1. The circuit board 60 is fed into the conveying device 10. 2. The conveying device 10 conveys the circuit board 60 to the flux spraying device 20, and the flux spraying device 20 sprays flux on the circuit board 60. 3. After the circuit board 60 is sprayed with flux, the circuit board 60 continues to move between the first preheating device 40 and the second preheating device 50, and the first preheating device 40 and the second preheating device 50 preheat the circuit board 60. 4. After the circuit board 60 is preheated, the conveying device 10 conveys the circuit board 60 to the welding device 30, and the welding device 30 welds the circuit board 60. Since the circuit board 60 is preheated before welding after the flux is sprayed, the welding quality is more guaranteed.

[0029] The first protective cover 41 can concentrate the heat, and the heat will be directed toward the circuit board 60, the first heating element 43 will generate heat, and the top of the circuit board 60 will be preheated. The second protective cover 51 can concentrate the heat, and the heat will be directed toward the circuit board 60, the second heating element 52 will generate heat, and the bottom of the circuit board 60 will be preheated. The heat-transmitting plate 53 is preferably glass, which can prevent the flux from dripping on the second heating element 52. The first heating element 43 is preferably an electric heating rod or an electric heating wire. The second heating element 52 is preferably an infrared heating lamp.

[0030] Preferably, the conveying device 10 includes a sliding module 11, a lifting module 12, and a carrier tooling 110; the lifting module 12 is arranged on the sliding module 11; the carrier tooling 110 is arranged on the lifting module 12; wherein the carrier tooling 110 includes a carrier bracket 111, a carrier 112, an adjustment plate 113, and an adjustment member 114; the carrier 112 is slidably arranged on the carrier bracket 111; the adjustment plate 113 is adjustably arranged on the carrier 112, and the adjustment member 114 is adjustably arranged on the adjustment plate 113; the adjustment member 114 clamps the circuit board 60. The sliding module 11 is preferably a linear module driven by a first servo motor. The lifting module 12 is preferably a screw module, which is driven by a second servo motor to move up and down. The carrier 112 is driven by a third servo motor to move. Therefore, in the common matching straight line of the sliding module 11, the lifting module 12, and the carrier tooling 110, the circuit board 60 can move in the XYZ direction. The circuit board 60 can move accurately and flexibly to each mechanism to complete the corresponding process. In this embodiment, there are two adjustment plates 113, and two adjustment members 114 are arranged on each adjustment plate 113. By adjusting the position of the adjustment plate 113 on the carrier 112 and the position of the adjustment member 114 on the adjustment plate 113, circuit boards 60 of different sizes can be matched, thereby increasing the use range of the carrier tooling 110.

[0031] Preferably, the adjustment plate 113 and the carrier 112 are provided with a first narrow and long adjustment hole, and the first fastener 115 fixes the adjustment plate 113 to the carrier 112; the adjustment plate 113 is provided with a second narrow and long adjustment hole, and the second fastener 116 fastens the adjustment member 114 to the adjustment plate 113; wherein the adjustment member 114 is L-shaped. The first fastener 115 and the second fastener 116 are preferably screws or spring bolts. After loosening the first fastener 115, the position of the adjustment plate 113 on the carrier 112 can be adjusted; after loosening the second fastener 116, the position of the adjustment member 114 on the adjustment plate 113 can be adjusted, which is very convenient to operate.

[0032] Preferably, the flux spraying device 20 includes a flux box 21, a nozzle bracket 22, and a nozzle 23; the nozzle bracket 22 is arranged on the flux box 21, and the nozzle 23 is adjustably arranged on the nozzle bracket 22. The nozzle 23 is adjusted in the position of the nozzle bracket 22 by a screw. This design can adapt to different use environments and facilitate the adjustment of the distance between the spraying and the circuit board 60. The excess flux from the nozzle 23 will fall into the flux box 21 for reuse, saving flux.

[0033] Preferably, the welding device 30 includes a tin furnace 31, a nitrogen hood 32 covering the tin furnace 31, and a solder head 35 connected to the tin furnace 31; a heat dissipation fan 36 for cooling the tin furnace 31 is provided on the nitrogen hood 32; the solder head 35 is covered with a reflow sleeve 37, and a reflow channel connected to the tin furnace 31 is formed between the solder head 35 and the reflow sleeve 37, so that the solder can flow back into the tin furnace 31. The nitrogen hood 32 is filled with nitrogen. Nitrogen is used as a protective gas to further ensure the quality of welding and prevent air from affecting the quality of welding. The heat dissipation fan 36 can control the temperature of the tin furnace 31 so that the solder in the tin furnace 31 is at an optimal welding temperature. The welding in the tin furnace 31 is pressurized and then soldered on the circuit board 60 from the solder head 35, and the quality of this welding will be better.

[0034] Preferably, the interior of the solder head 35 is a hollow structure, and the hollow structure can extrude solder; a plurality of air holes 34 are provided on the annular seat 33 of the nitrogen cover 32, and the solder head 35 passes through the annular seat 33, and nitrogen can be discharged from the air holes 34. The molten solder is extruded from the hollow structure inside the solder head 35 to the circuit board 60, and the quality of such welding is more guaranteed. During welding, nitrogen can be ejected from the air holes 34 of the annular seat 33, which can form protection at the welding position and help to ensure the welding quality.

[0035] Preferably, the first preheating device 40 further includes a first lampshade 42 disposed in the first protective cover 41, a first thermocouple thermometer 44 disposed in the first lampshade 42, and a first air pipe 45 disposed on the outside of the first heating element 43; the air outlet of the first air pipe 45 can blow air toward the circuit board 60. The first lampshade 42 is used to prevent heat loss and control the direction of heat. The first thermocouple thermometer 44 is used to measure temperature. The first heating element 43 in this embodiment is an electric heating tube. Its heat will be transferred to the circuit board 60 through the air to preheat the circuit board 60. The first air pipe 45 is connected to an air pump, and the air outlet of the first air pipe 45 blows air toward the circuit board 60 to control the temperature of the circuit board 60. If the temperature is too high, air blowing is performed to cool it down. The first heating element 43 and the first air pipe 45 are staggered. This design helps to directly transfer heat to the circuit board and improve the heating efficiency.

[0036] Preferably, the second preheating device 50 also includes a second lampshade arranged in the second protective cover 51 and a second thermocouple thermometer 54 arranged on the outside of the heat-transmitting plate 53 (preferably glass); wherein the second lampshade has a plurality of reflection grooves 55, and the second heating element 52 is arranged in the reflection grooves 55. The first heating element 43 is a resistance heating element, and the second heating element 52 is an infrared lamp tube; the structure of the reflection groove 55 is in the shape of an isosceles trapezoid. The second lampshade is used to prevent heat loss and control the direction of heat. The second heating element 52 in this embodiment is an infrared heating tube. The second thermocouple thermometer 54 is used to measure the temperature to prevent the circuit board 60 from overheating. The structure of the reflection groove 55 is in the shape of an isosceles trapezoid, which allows the heat of the second heating element 52 to be more evenly transferred to the circuit board 60.

[0037] Embodiment 2 The present application provides a circuit board welding method, including S1, loading, placing a circuit board 60 into a conveying device 10. The adjusting member 114 clamps the circuit board 60, and then the conveying device 10 conveys the circuit board 60.

[0038] S2, spraying flux, the flux spraying device 20 is arranged at the lower side of the conveying device 10; the conveying device 10 conveys the circuit board 60 to the flux spraying device 20, and the flux spraying device 20 sprays flux on the circuit board 60. The circuit board 60 of this embodiment is soldered by wave soldering, and the pressure of the flux spraying is controlled at 0.2-0.3Mpa, which helps to ensure the spraying quality.

[0039] S3, preheating the circuit board 60; after the circuit board 60 is sprayed with solder flux, the conveying device 10 conveys the circuit board 60 between the first preheating device 40 and the second preheating device 50, and the first preheating device 40 and the second preheating device 50 simultaneously preheat the circuit board 60. The preheating temperature of the circuit board 60 in this embodiment is between 370-300 degrees Celsius, preferably 280 degrees Celsius. During preheating, ensure that the solder point temperature is 50 degrees Celsius higher than the melting point of the solder to achieve a reliable welding effect.

[0040] S4, welding of the circuit board 60: after the circuit board 60 is preheated, the conveying device 10 conveys the circuit board 60 to the welding device 30, and the welding device 30 welds the circuit board 60. After the circuit board 60 is preheated, the welding device 30 applies solder to the soldering point to complete the welding process.

[0041] S5, taking out the circuit board 60; taking out the circuit board 60 manually or by a robot.

[0042] In summary, the design focus of the present invention is that after the flux is sprayed, the first preheating device 40 and the second preheating device 50 preheat the circuit board 60 so that the circuit board 60 is at an optimal welding temperature and the welding quality is more guaranteed.

[0043] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A welding machine with upper and lower preheating, characterized in that: It includes a conveying device, a flux spraying device, a welding device, a first preheating device, and a second preheating device; The conveying device is used to convey the circuit board; the flux spraying device and the welding device are arranged beside the conveying device; The first preheating device is arranged on the first side of the circuit board movement track, and the first preheating device comprises a first protective cover and a first heating element arranged in the first protective cover; The second preheating device is arranged on the second side of the circuit board movement track; the second preheating device comprises a second protective cover, a second heating element arranged in the second protective cover, and a heat-transmitting plate arranged on the second protective cover.

2. A welding machine with upper and lower preheating according to claim 1, characterized in that: The conveying device includes a sliding module, a lifting module, and a carrier tooling; the lifting module is arranged on the sliding module; the carrier tooling is arranged on the lifting module; wherein the carrier tooling includes a carrier bracket, a carrier, an adjustment plate, and an adjustment member; the carrier is slidably arranged on the carrier bracket; the adjustment plate is adjustably arranged on the carrier, and the adjustment member is adjustably arranged on the adjustment plate; the adjustment member clamps the circuit board.

3. A welding machine with upper and lower preheating according to claim 2, characterized in that: The adjustment plate and the carrier are provided with a first narrow and long adjustment hole, and the adjustment plate is fixed to the carrier by a first fastener; the adjustment plate is provided with a second narrow and long adjustment hole, and the adjustment member is fastened to the adjustment plate by a second fastener; wherein the adjustment member is L-shaped.

4. A welding machine with upper and lower preheating according to claim 1, characterized in that: The soldering flux spraying device comprises a soldering flux box, a nozzle bracket and a nozzle; the nozzle bracket is arranged on the soldering flux box, and the nozzle is adjustably arranged on the nozzle bracket.

5. A welding machine with upper and lower preheating according to claim 1, characterized in that: The soldering device comprises a tin furnace, a nitrogen hood covering the tin furnace, and a solder head connected to the tin furnace; a heat dissipation fan for cooling the tin furnace is arranged on the nitrogen hood; the solder head is covered with a reflow sleeve, and a reflow channel connected to the tin furnace is formed between the solder head and the reflow sleeve, so that the solder can flow back into the tin furnace.

6. A welding machine with upper and lower preheating according to claim 5, characterized in that: The interior of the solder head is a hollow structure, and the solder can be squeezed out of the hollow structure; a plurality of air holes are arranged on the annular seat of the nitrogen cover, and the solder head passes through the annular seat, and nitrogen can be discharged from the air holes.

7. A welding machine with upper and lower preheating according to claim 1, characterized in that: The first preheating device also includes a first lampshade arranged in the first protective cover, a first thermocouple thermometer arranged in the first lampshade, and a first air pipe arranged outside the first heating element; the first air pipe can blow air toward the circuit board.

8. A welding machine with upper and lower preheating according to claim 7, characterized in that: The second preheating device also includes a second lampshade arranged in the second protective cover and a second thermocouple thermometer arranged outside the heat-transmitting plate; wherein the second lampshade has a plurality of reflecting grooves, and the second heating element is arranged in the reflecting grooves.

9. A welding machine with upper and lower preheating according to claim 7, characterized in that: The first heating element is a resistance heating element, and the second heating element is an infrared lamp tube; the structure of the reflection groove is an isosceles trapezoidal shape.

10. A circuit board welding method, characterized in that: The method includes S1, loading, placing the circuit board into the conveying device; S2, spraying flux, the conveying device conveys the circuit board to the flux spraying device, and the flux spraying device sprays flux on the circuit board; S3, preheating the circuit board; after the circuit board is sprayed with flux, the conveying device conveys the circuit board between the first preheating device and the second preheating device, and the first preheating device and the second preheating device preheat the circuit board at the same time; S4, welding the circuit board; after the circuit board is preheated, the conveying device conveys the circuit board to the welding device, and the welding device welds the circuit board.

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