A detection device and method for circuit board soldering

Abstract

The application relates to the technical field of circuit board welding detection, and specifically discloses a detection device and a detection method for circuit board welding, which comprises a mounting frame, a welding station is arranged on the mounting frame, a soldering gun is arranged on one side of the welding station, a film unwinding roller and a film winding roller are further arranged on the two sides of the welding station, a stress change sensing film is wound on the film unwinding roller, a fitting mechanism is arranged above and below the welding station, a light source and a high-definition camera are arranged directly above the welding station, the fitting mechanism in the application can tightly fit the stress change sensing film on the circuit board, if the stress inside the circuit board changes, the color of the stress change sensing film will change when the fixed point is observed, the high-definition camera is used to take photos of the circuit board before and after the stress change sensing film is tightly covered, the color change of the stress change sensing film on the two photos is compared, and the change amount of the stress can be quickly and intuitively judged.

Description

Technical Field

[0001] This application relates to the field of circuit board soldering inspection technology, and in particular to an inspection device and inspection method for circuit board soldering. Background Technology

[0002] Automotive circuit boards are core components of automotive electronic control systems, widely used in critical areas such as engine management systems, body control modules, airbag systems, in-vehicle entertainment systems, and advanced driver assistance systems. Their functional stability directly affects vehicle safety and performance. Automotive circuit board soldering refers to the process of electrically and mechanically connecting electronic components to the circuit board substrate using soldering technology. Soldering quality must meet standards for conductivity, mechanical strength, and environmental resistance. For example, solder joints should be free of defects such as incomplete soldering, cold soldering, and bridging, and must pass visual inspection and reliability testing.

[0003] In current technologies, the inspection of welding quality on automotive circuit boards primarily employs automated optical inspection (AOI) equipment or X-ray inspection systems. AOI devices typically consist of a high-resolution camera, a multi-angle ring light source, an image processing unit, and a mechanical transmission platform. They identify surface defects by capturing images of the solder joints and comparing them with a preset template. X-ray inspection systems utilize X-rays penetrating the circuit board, receiving attenuated signals through sensors, and reconstructing images of the internal structure to detect hidden defects such as voids and cracks within the solder joints. Some high-end equipment also integrates infrared thermal imaging capabilities, indirectly assessing welding quality by analyzing the temperature distribution curves of the solder joints during the welding process.

[0004] Regarding the aforementioned technologies, during the soldering process, the temperature of liquid tin is typically as high as 220°C to 250°C. The high temperature may cause thermal expansion or local carbonization and depression of the circuit board substrate around the electronic components, thereby changing the internal stress distribution. Stress changes are basically undetectable by visual observation alone. Subsequently, the circuit board may undergo slight deformation due to stress release, leading to poor solder joint contact or cracking, ultimately causing the electronic module to fail. Therefore, improvements are needed. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a testing device and method for circuit board soldering.

[0006] This application provides a testing device for circuit board soldering, which adopts the following technical solution:

[0007] A testing device for circuit board soldering includes a mounting frame with multiple sets of first conveyor rollers and multiple sets of second conveyor rollers rotatably mounted on it. A soldering station is positioned between the first and second conveyor rollers. A robotic arm is mounted on one side of the soldering station, and a soldering gun for soldering electronic components on the circuit board is mounted on the robotic arm. Thin film unwinding rollers and thin film rewinding rollers are also mounted on both sides of the soldering station. The thin film unwinding rollers rewind stress change sensing films that have been pre-drilled at the locations on the circuit board that require soldering. The width of the stress change sensing films is greater than the length of the circuit board. Adhesion mechanisms for tightly adhering the stress change sensing films to the circuit board are positioned above and below the soldering station. A light source and a high-definition camera are positioned directly above the soldering station.

[0008] By adopting the above technical solution, the first conveyor roller transports the circuit board to the soldering station. The bonding mechanism in this application can tightly bond the stress change sensing film onto the circuit board. At a fixed point, if the stress inside the circuit board changes, the reflection angle of the light shining on the stress change sensing film at the fixed point will change. Therefore, when observed at the fixed point, the color of the stress change sensing film will change. The light source at the fixed point is turned on, and a high-definition camera at the fixed point takes a picture of the circuit board that has been tightly covered with the stress change sensing film. Finally, the circuit board is soldered using a soldering gun. After soldering, the soldered circuit board is photographed at the same fixed points using a high-definition camera. If the soldering changes the stress level within the circuit board, the color change of the stress change sensing film in the two photos can be compared to quickly and intuitively determine the amount of stress change. If the change is too large, slight deformation may occur due to stress release, leading to poor solder joint contact or cracking, ultimately causing the electronic module to malfunction. In addition, the stress change sensing film can also protect the non-soldering areas of the circuit board, preventing contamination of these areas during the soldering process and affecting the normal use of the circuit board.

[0009] Optionally, the bonding mechanism includes a movable frame, an upper support plate, a lower support plate, a translation cylinder, a lifting cylinder, an air extraction assembly, and a cutting assembly. The movable frame is horizontally movable on the mounting frame, the upper support plate is lifted and lowered on the movable frame, the lower support plate is lifted and lowered on the mounting frame, the upper support plate is positioned above the lower support plate, and the welding station is located between the upper support plate and the lower support plate.

[0010] A first abutment post is provided on the side of the upper support plate near the lower support plate, corresponding to the opening position of the stress change sensing film. A clearance groove is provided on the first abutment post corresponding to the position of the electronic component on the circuit board. The diameter of the clearance groove is the same as the diameter of the opening of the stress change sensing film. A second abutment post is provided on the side of the lower support plate near the upper support plate, corresponding to the bolt hole of the circuit board. An air extraction channel is provided in the second abutment post.

[0011] The translation cylinder is fixedly mounted on the mounting frame, and its telescopic end is connected to the movable frame. Two sets of lifting cylinders are provided, each fixedly mounted on the movable frame and the mounting frame, with their telescopic ends connected to the opposite sides of the upper and lower support plates. The air extraction assembly is located on the side of the lower support plate away from the upper support plate, and is used to extract air between the stress change sensing film and the circuit board through the bolt holes on the circuit board and the air extraction channel in the second abutment column, ensuring a tight fit between the circuit board and the stress change sensing film. The cutting assembly is located on the movable frame and is used to cut the stress change sensing film after the circuit board has been laminated.

[0012] By adopting the above technical solution, the translation cylinder is activated to move the movable frame to the welding station. Then, the lifting cylinder is activated to bring the upper and lower support plates closer together to clamp the circuit board and the stress change sensing film. The first abutment post on the upper support plate is tightly abutted against the circuit board, and the second abutment post is tightly abutted against the bolt holes of the circuit board. Since the second abutment post has an air extraction channel, the air extraction component in this application can extract the air between the circuit board and the stress change sensing film through the air extraction channel, making the circuit board and the stress change sensing film fit more tightly, thereby better displaying the stress change of the circuit board after welding. The cutting component in this application can cut the stress change sensing film after the circuit board and the stress change sensing film are tightly fitted, thereby realizing the detection method of a single circuit board corresponding to a single stress change sensing film. Compared with multiple circuit boards corresponding to a single stress change sensing film, it can avoid the situation where the stress change sensing film is contaminated by impurities on the circuit board and the stress change sensing film itself changes due to repeated use of the stress change sensing film.

[0013] Optionally, the air extraction assembly includes an air extraction pump and an air extraction pipe. Multiple sets of the second abutment columns are provided. An air extraction chamber is opened in the lower support plate. The air extraction channels opened in the multiple sets of the second abutment columns are all connected to the air extraction chamber. The air extraction pump is fixedly installed on the side of the lower support plate away from the upper support plate, and the air extraction end is connected to the air extraction chamber through the air extraction pipe.

[0014] By adopting the above technical solution, when the air pump is started, the upper and lower support plates abut against each other to seal and clamp the circuit board and the stress change sensing film as a whole. The first abutting post abuts tightly against the opening position of the stress change sensing film, and the second abutting post abuts tightly against the bolt holes on the circuit board. Therefore, the air pump can extract the air between the circuit board and the stress change sensing film through the air extraction pipe, air extraction channel, and the bolt holes on the circuit board. This makes the stress change sensing film adhere more tightly to the circuit board and improves the sensing accuracy of changes in the internal environment of the circuit board.

[0015] Optionally, the cutting assembly includes a horizontal cutting blade and a vertical cutting blade, both of which are fixedly mounted on the side wall of the upper support plate and are perpendicular to each other. Two sets of both horizontal and vertical cutting blades are provided. The two sets of horizontal cutting blades are used to cut the two horizontal edges of the stress change sensing film covering the circuit board, and the two sets of vertical cutting blades are used to cut the two vertical edges of the stress change sensing film covering the circuit board.

[0016] By adopting the above technical solution, when the lifting air rod drives the upper support plate to descend, the horizontal and vertical cutting blades fixedly installed on the four side walls of the upper support plate can simultaneously cut the two horizontal and two vertical edges of the stress change sensing film covering the circuit board. This enables the detection method of a single circuit board corresponding to a single stress change sensing film, avoiding the situation where the stress change sensing film is contaminated by impurities on the circuit board and the tension of the stress change sensing film itself changes due to repeated use of the stress change sensing film.

[0017] Optionally, the length of the stress change sensing film covering the circuit board is greater than the length of the circuit board. A negative pressure cylinder is provided on the mounting bracket, and a negative pressure roller is provided on the telescopic end of the negative pressure cylinder. The negative pressure roller is hollow in the middle and has a negative pressure hole. A negative pressure air pump is fixedly provided on the mounting bracket, and a negative pressure pipe is provided on the suction end of the negative pressure air pump. The end of the negative pressure pipe away from the negative pressure air pump is connected to the inside of the negative pressure roller.

[0018] By adopting the above technical solution, the negative pressure air pump is started, and the negative pressure air pump forms negative pressure at the negative pressure hole of the negative pressure roller through the negative pressure pipe. Then, the negative pressure cylinder moves the negative pressure pipe to a suitable height. Since the length of the stress change sensing film covering the circuit board is greater than the length of the circuit board, the negative pressure hole can adsorb the end of the stress change sensing film protruding from the circuit board. When the first conveying roller and the second conveying roller continue to move the circuit board, the stress change sensing film can be automatically peeled off the circuit board.

[0019] Optionally, a first electric telescopic rod is fixedly disposed above the unwinding roller, and a first adjusting roller is disposed on the telescopic end of the first electric telescopic rod. A second electric telescopic rod is fixedly disposed above the winding roller, and a second adjusting roller is disposed on the telescopic end of the second electric telescopic rod. The first adjusting roller and the second adjusting roller are used to adjust the height of the stress change sensing film output by the unwinding roller.

[0020] By adopting the above technical solution, the first electric telescopic rod and the second electric telescopic rod can adjust the height of the first adjusting roller and the second adjusting roller respectively, thereby realizing the height adjustment of the stress change sensing film output by the film unwinding roller, so as to paste the stress change sensing film onto the circuit board.

[0021] Optionally, a clamping cylinder is fixedly installed on the movable frame, and a clamping frame is provided on the telescopic end of the clamping cylinder. When both the clamping frame and the second abutting post abut against the circuit board, the circuit board is clamped and fixed.

[0022] By adopting the above technical solution, after the stress change sensing film is pasted on the circuit board and the upper support plate is removed, the clamping cylinder is activated. The clamping cylinder drives the clamping frame to descend, so that the clamping frame abuts against the circuit board on which the stress change sensing film has been pasted. This, together with the second abutment post, clamps and fixes the circuit board, avoiding disturbance to the circuit board during soldering, which would affect the subsequent comparison of two photographs and improve the accuracy of judging the internal stress change response of the circuit board.

[0023] This application also includes a method for inspecting circuit board soldering, comprising the following steps:

[0024] S1: The circuit board is conveyed to the welding station by the first and second conveyor rollers. The film unwinding roller and film take-up roller are started to convey the stress change sensing film to the top of the welding station. Then the first and second electric telescopic rods are started to adjust the height of the stress change sensing film and initially attach the stress change sensing film to the circuit board.

[0025] S2: Start the translation cylinder to move the upper support plate to directly above the lower support plate, then start the lifting cylinder to bring the upper and lower support plates into contact, start the air pump, the air pump extracts the air between the circuit board and the stress change sensing film through the air extraction pipe and air extraction channel, so that the stress change sensing film and the circuit board are tightly attached, and then start the horizontal cutting cylinder and the vertical cutting cylinder to drive the horizontal cutting blade and the vertical cutting blade to cut the stress change sensing film.

[0026] S3: After cutting, move the upper support plate away from the lower support plate, start the clamping cylinder, and clamp and fix the circuit board by abutting the clamping column and the second abutting column. After clamping and fixing, turn on the light source and high-definition camera to take pictures of the circuit board before soldering.

[0027] S4: Start the soldering gun to solder the circuit board. After the soldering is completed, take another picture of the circuit board with a high-definition camera. By comparing the color change of the stress change sensing film in the two pictures, you can know the stress change of the circuit board.

[0028] S5: When the stress change of the circuit board is not obvious, it indicates that the circuit board is successfully soldered. At this time, separate the clamping post and the second abutment post from the circuit board, start the first electric telescopic rod to adjust the negative pressure roller to a suitable height, and move the circuit board to the negative pressure roller through the first and second conveyor rollers. Then start the negative pressure air pump to make the end of the stress change sensing film covering the circuit board adhere to the negative pressure roller. As the circuit board that has been soldered continues to move, the stress change sensing film covering the circuit board can be peeled off.

[0029] In summary, this application includes at least one of the following beneficial technical effects:

[0030] 1. The bonding mechanism in this application can tightly bond the stress change sensing film to the circuit board. At a fixed point, if the stress inside the circuit board changes, the reflection angle of the light shining on the stress change sensing film at the fixed point will change, so the color of the stress change sensing film will change when observed at the fixed point. Turn on the light source at the fixed point, take a picture of the circuit board that has been tightly covered with the stress change sensing film through a high-definition camera at the fixed point, and finally solder the circuit board with a soldering gun. After soldering, take another picture of the soldered circuit board at the same fixed point through the high-definition camera. If the soldering changes the stress in the circuit board, the color change of the stress change sensing film in the two pictures can be compared to quickly and intuitively judge the amount of stress change. If the change is too large, it may cause slight deformation due to stress release, resulting in poor solder joint contact or cracking, and ultimately causing the electronic module to fail. In addition, the stress change sensing film can also protect the non-soldering area of ​​the circuit board to prevent the non-soldering area from being contaminated during the soldering process, which would affect the normal use of the circuit board.

[0031] 2. The cutting component can cut the stress change sensing film after it is tightly bonded between the circuit board and the stress change sensing film, thereby realizing the detection method of one stress change sensing film for one circuit board. Compared with the method of one stress change sensing film for multiple circuit boards, it can avoid the situation that the stress change sensing film is contaminated by impurities on the circuit board and the stress change sensing film itself changes due to repeated use of the stress change sensing film.

[0032] 3. Start the negative pressure air pump. The negative pressure air pump creates negative pressure at the negative pressure hole of the negative pressure roller through the negative pressure pipe. Then, the negative pressure cylinder moves the negative pressure pipe to a suitable height. Since the length of the stress change sensing film covering the circuit board is greater than the length of the circuit board, the negative pressure hole can adsorb the end of the stress change sensing film protruding from the circuit board. When the first and second conveyor rollers continue to move the circuit board, the stress change sensing film can be automatically peeled off the circuit board. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;

[0035] Figure 2 yes Figure 1 Partial structural diagram;

[0036] Figure 3 yes Figure 2 A schematic diagram of the cross-sectional structure;

[0037] Figure 4 yes Figure 3 Enlarged schematic diagram of section A.

[0038] Reference numerals: 1. Mounting frame; 11. First conveyor roller; 12. Second conveyor roller; 13. Robotic arm; 14. Film unwinding roller; 15. Film rewinding roller; 2. Laminating mechanism; 21. Movable frame; 22. Upper support plate; 221. First abutment post; 23. Lower support plate; 231. Second abutment post; 24. Translation cylinder; 25. Lifting cylinder; 26. Air extraction assembly; 261. Air extraction pump; 262. Air extraction pipe; 27. Cutting assembly; 271. Transverse cutting blade; 3. Light source; 4. High-definition camera; 5. Negative pressure cylinder; 51. Negative pressure roller; 52. Negative pressure pump; 53. Negative pressure pipe; 6. First electric telescopic rod; 61. First adjusting roller; 7. Second electric telescopic rod; 71. Second adjusting roller; 8. Clamping cylinder; 81. Clamping frame. Detailed Implementation

[0039] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0040] This application discloses a testing device and method for circuit board soldering, referring to... Figure 1 and Figure 2 A testing device for circuit board soldering includes a mounting frame 1. Multiple sets of first conveyor rollers 11 and multiple sets of second conveyor rollers 12 are rotatably mounted on the mounting frame 1. A soldering station is provided between the first conveyor rollers 11 and the second conveyor rollers 12. A robotic arm 13 is mounted on one side of the soldering station. A soldering gun for soldering electronic components on the circuit board is provided on the robotic arm 13. A film unwinding roller 14 and a film winding roller 15 are rotatably mounted on both sides of the soldering station. A stress change sensing film with holes already made corresponding to the soldering positions on the circuit board is wound on the film unwinding roller 14. The width of the stress change sensing film is set to be greater than the length of the circuit board. A bonding mechanism 2 is provided above and below the soldering station. A light source 3 and a high-definition camera 4 are fixedly mounted directly above the soldering station.

[0041] The first conveyor roller 11 transports the circuit board to the soldering station. In this embodiment, the bonding mechanism 2 can tightly bond the stress change sensing film to the circuit board. At a fixed point, if the stress inside the circuit board changes, the reflection angle of the light shining on the stress change sensing film at the fixed point will change, thus changing the color of the stress change sensing film when observed at the fixed point. The light source 3 at the fixed point is turned on, and the circuit board tightly covered with the stress change sensing film is photographed by the high-definition camera 4 at the fixed point. Finally, the circuit board is soldered using a soldering gun. After completion, a high-definition camera 4 takes photos of the same fixed points on the soldered circuit board. If the soldering changes the stress level within the circuit board, the color change of the stress change sensing film in the two photos can be compared to quickly and intuitively determine the amount of stress change. If the change is too large, slight deformation may occur due to stress release, leading to poor solder joint contact or cracking, ultimately causing the electronic module to malfunction. In addition, the stress change sensing film can also protect the non-soldering areas of the circuit board, preventing contamination of the non-soldering areas during the soldering process and affecting the normal use of the circuit board.

[0042] Reference Figure 3 and Figure 4 In order to achieve tight bonding of the stress change sensing film to the circuit board, the high-end bonding mechanism 2 in this embodiment includes a movable frame 21, an upper support plate 22, a lower support plate 23, a translation cylinder 24, a lifting cylinder 25, an air extraction component 26, and a cutting component 27. The movable frame 21 is horizontally moved and installed on the mounting frame 1. The upper support plate 22 is lifted and installed on the movable frame 21. The lower support plate 23 is lifted and installed on the mounting frame 1. The upper support plate 22 is installed above the lower support plate 23, and the welding station is located between the upper support plate 22 and the lower support plate 23.

[0043] A first abutment post 221 is welded and installed on the side of the upper support plate 22 near the lower support plate 23, corresponding to the opening position of the stress change sensing film. A clearance groove is provided on the first abutment post 221 corresponding to the position of the electronic component on the circuit board. The diameter of the clearance groove is the same as the diameter of the opening of the stress change sensing film. A second abutment post 231 is welded and installed on the side of the lower support plate 23 near the upper support plate 22, corresponding to the bolt hole of the circuit board. An air extraction channel is provided in the second abutment post 231.

[0044] The translation cylinder 24 is bolted to the mounting frame 1, and its telescopic end is welded to the movable frame 21. Two sets of lifting cylinders 25 are installed. The two sets of lifting cylinders 25 are respectively bolted to the movable frame 21 and the mounting frame 1, and their telescopic ends are respectively welded to the opposite sides of the upper support plate 22 and the lower support plate 23. The air extraction assembly 26 is installed on the side of the lower support plate 23 away from the upper support plate 22. The cutting assembly 27 is installed on the movable frame 21.

[0045] The translation cylinder 24 is activated to move the movable frame 21 to the welding station. Then, the lifting cylinder 25 is activated to bring the upper support plate 22 and the lower support plate 23 closer together, clamping the circuit board and the stress change sensing film. This ensures that the first abutment post 221 on the upper support plate 22 is in close contact with the circuit board, and the second abutment post 231 is in close contact with the bolt holes on the circuit board. Since the second abutment post 231 has an air extraction channel, the air extraction assembly 26 in this embodiment can extract the air between the circuit board and the stress change sensing film through the air extraction channel, thus ensuring the circuit board and... The stress change sensing films are more tightly bonded, thus better displaying the stress changes of the circuit board after soldering. In this embodiment, the cutting component 27 can cut the stress change sensing film after the circuit board and the stress change sensing film are tightly bonded, thereby realizing the detection method of one stress change sensing film for one circuit board. Compared with multiple circuit boards corresponding to one stress change sensing film, it can avoid the situation where the stress change sensing film is contaminated by impurities on the circuit board and the tension of the stress change sensing film itself changes due to repeated use of the stress change sensing film.

[0046] Reference Figure 2 Air between the circuit board and the stress change sensing film can cause the stress change sensing film to react abnormally to stress changes in the circuit board. Therefore, the air extraction assembly 26 in this embodiment includes an air extraction pump 261 and an air extraction pipe 262. Multiple sets of second abutment posts 231 are welded and installed. An air extraction chamber is opened in the lower support plate 23. The air extraction channels opened in the multiple sets of second abutment posts 231 are all connected to the air extraction chamber. The air extraction pump 261 is bolted and fixedly installed on the side of the lower support plate 23 away from the upper support plate 22, and the air extraction end is connected to the air extraction chamber through the air extraction pipe 262.

[0047] When the air pump 261 is started, the upper support plate 22 and the lower support plate 23 abut against each other to form a sealed clamp for the circuit board and the stress change sensing film. The first abutting post 221 abuts tightly against the opening position of the stress change sensing film, and the second abutting post 231 abuts tightly against the bolt hole on the circuit board. Therefore, the air pump 261 can extract the air between the circuit board and the stress change sensing film through the air extraction pipe 262, the air extraction channel and the bolt hole on the circuit board. This makes the stress change sensing film adhere more tightly to the circuit board and improves the sensing accuracy of changes in the circuit board.

[0048] Reference Figure 3In order to cut the stress change sensing film, the cutting component 27 in this embodiment includes a transverse cutting blade 271 and a longitudinal cutting blade. Both the transverse cutting blade 271 and the longitudinal cutting blade are fixedly welded to the side wall of the upper support plate 22, and the transverse cutting blade 271 and the longitudinal cutting blade are perpendicular to each other. Both the transverse cutting blade 271 and the longitudinal cutting blade are provided in two sets. The two sets of transverse cutting blades 271 are used to cut the two transverse edges of the stress change sensing film covering the circuit board, and the two sets of longitudinal cutting blades are used to cut the two longitudinal edges of the stress change sensing film covering the circuit board.

[0049] When the lifting air rod drives the upper support plate 22 to descend, the horizontal cutting blade 271 and the vertical cutting blade fixedly installed on the four side walls of the upper support plate 22 can simultaneously cut the two horizontal and two vertical edges of the stress change sensing film covering the circuit board. This enables the detection method of a single circuit board corresponding to a single stress change sensing film, avoiding the situation where the stress change sensing film is contaminated by impurities on the circuit board and the tension of the stress change sensing film itself changes due to repeated use of the stress change sensing film.

[0050] Reference Figure 1 and Figure 2 Manually removing the stress change sensing film covering the circuit board is quite troublesome. Therefore, in order to achieve fully automatic removal of the stress change sensing film covering the circuit board and facilitate subsequent circuit board processing, the length of the stress change sensing film covering the circuit board in this embodiment is set to be greater than the length of the circuit board. A negative pressure cylinder 5 is bolted to the mounting frame 1. A negative pressure roller 51 is welded to the telescopic end of the negative pressure cylinder 5. The negative pressure roller 51 is hollow in the middle and has a negative pressure hole. A negative pressure air pump 52 is bolted to the mounting frame 1. A negative pressure pipe 53 is installed on the suction end of the negative pressure air pump 52. The end of the negative pressure pipe 53 away from the negative pressure air pump 52 is connected to the inside of the negative pressure roller 51.

[0051] The negative pressure air pump 52 is started, and the negative pressure air pump 52 forms negative pressure at the negative pressure hole of the negative pressure roller 51 through the negative pressure pipe 53. Then, the negative pressure cylinder 5 moves the negative pressure pipe 53 to a suitable height. Since the length of the stress change sensing film covering the circuit board is greater than the length of the circuit board, the negative pressure hole can adsorb the end of the stress change sensing film protruding from the circuit board. When the first conveying roller 11 and the second conveying roller 12 continue to move the circuit board, the stress change sensing film can be automatically peeled off the circuit board.

[0052] Reference Figure 1 and Figure 2To meet the requirements for mechanical performance coating of circuit boards of different thicknesses, in this embodiment, a first electric telescopic rod 6 is bolted to the top of the film unwinding roller 14, and a first adjusting roller 61 is rotatably mounted on the telescopic end of the first electric telescopic rod 6. A second electric telescopic rod 7 is bolted to the top of the film take-up roller 15, and a second adjusting roller 71 is rotatably mounted on the telescopic end of the second electric telescopic rod 7. The first electric telescopic rod 6 and the second electric telescopic rod 7 can adjust the height of the first adjusting roller 61 and the second adjusting roller 71 respectively, thereby realizing the height adjustment of the stress change sensing film output by the film unwinding roller 14, so as to adhere the stress change sensing film to the circuit board.

[0053] Reference Figure 1 and Figure 3 During soldering, disturbance to the circuit board may cause displacement. Therefore, in this embodiment, a clamping cylinder 8 is bolted to the movable frame 21, and a clamping frame 81 is welded to the telescopic end of the clamping cylinder 8. After the stress change sensing film is pasted onto the circuit board and the upper support plate 22 is removed, the clamping cylinder 8 is activated. The clamping cylinder 8 drives the clamping frame 81 to descend, so that the clamping frame 81 abuts against the circuit board with the stress change sensing film pasted on it. This, in conjunction with the second abutment post 231, clamps and fixes the circuit board, avoiding disturbance to the circuit board during soldering, which would affect the subsequent comparison of two photographs and improve the accuracy of judging the internal stress change response of the circuit board.

[0054] The implementation principle of the inspection device for circuit board soldering in this application embodiment is as follows:

[0055] When it is necessary to tightly adhere the stress change sensing film to the circuit board, the circuit board is conveyed to the soldering station by the first conveyor roller 11 and the second conveyor roller 12. The film unwinding roller 14 and the film take-up roller 15 are activated to convey the stress change sensing film above the soldering station. Then, the first electric telescopic rod 6 and the second electric telescopic rod 7 are activated to adjust the height of the stress change sensing film, so that the stress change sensing film is initially adhered to the circuit board. The translation cylinder 24 is activated to move the upper support plate 22 directly above the lower support plate 23. Then, the lifting cylinder 25 is activated to bring the upper support plate 22 and the lower support plate 23 into contact. The air pump 261 is activated, and the air pump 261 extracts the air between the circuit board and the stress change sensing film through the air extraction pipe 262 and the air extraction channel, so that the stress change sensing film and the circuit board are tightly adhered.

[0056] When it is necessary to detect the internal stress change of the circuit board before and after welding, the clamping cylinder 8 is activated, and the circuit board is clamped and fixed by the clamping column and the second abutment column 231. After clamping and fixing, the light source 3 and the high-definition camera 4 are turned on to take pictures of the circuit board before welding. The soldering gun is started to weld the circuit board. After welding, the circuit board is photographed again by the high-definition camera 4. By comparing the color change of the stress change sensing film in the two pictures, the stress change of the circuit board can be known. When the stress change of the circuit board is not obvious, it means that the welding of the circuit board is qualified.

[0057] This application also discloses a method for inspecting circuit board soldering:

[0058] S1: The circuit board is conveyed to the welding station by the first conveyor roller 11 and the second conveyor roller 12. The film unwinding roller 14 and the film take-up roller 15 are started to convey the stress change sensing film above the welding station. Then the first electric telescopic rod 6 and the second electric telescopic rod 7 are started to adjust the height of the stress change sensing film and initially attach the stress change sensing film to the circuit board.

[0059] S2: Start the translation cylinder 24 to move the upper support plate 22 directly above the lower support plate 23, then start the lifting cylinder 25 to bring the upper support plate 22 and the lower support plate 23 into contact, start the vacuum pump 261, the vacuum pump 261 extracts the air between the circuit board and the stress change sensing film through the vacuum pipe 262 and the vacuum channel, so that the stress change sensing film and the circuit board are tightly attached, and then start the horizontal cutting cylinder and the vertical cutting cylinder to drive the horizontal cutting blade 271 and the vertical cutting blade to cut the stress change sensing film.

[0060] S3: After cutting, move the upper support plate 22 away from the lower support plate 23, start the clamping cylinder 8, and clamp and fix the circuit board by abutting the clamping column and the second abutting column 231. After clamping and fixing, turn on the light source 3 and the high-definition camera 4 to take pictures of the circuit board before soldering.

[0061] S4: Start the solder gun to solder the circuit board. After the soldering is completed, take another picture of the circuit board through the high-definition camera 4. By comparing the color change of the stress change sensing film in the two pictures, you can know the stress change of the circuit board.

[0062] S5: When the stress change of the circuit board is not obvious, it indicates that the soldering of the circuit board is qualified. At this time, the clamping post and the second abutment post 231 are separated from the circuit board. The first electric telescopic rod 6 is started to adjust the negative pressure roller 51 to a suitable height. The circuit board is moved to the negative pressure roller 51 through the first conveyor roller 11 and the second conveyor roller 12. Then the negative pressure air pump 52 is started to make the end of the stress change sensing film covering the circuit board adhere to the negative pressure roller 51. As the circuit board that has been soldered is moved, the stress change sensing film covering the circuit board can be peeled off.

[0063] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar words used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "a" or "an," and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," and similar words mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0064] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A detection device for soldering of circuit boards, comprising a mounting frame (1), characterised in that: The mounting frame (1) is provided with a plurality of groups of first conveying rollers (11) and a plurality of groups of second conveying rollers (12) which are rotatably arranged on the mounting frame (1), a welding station is arranged between the first conveying rollers (11) and the second conveying rollers (12), a mechanical arm (13) is arranged on one side of the welding station, a soldering gun for welding electronic components of a circuit board is arranged on the mechanical arm (13), film unwinding rollers (14) and film winding rollers (15) are further arranged on both sides of the welding station, a stress change sensing film which has been punched according to positions on the circuit board which need to be welded is wound on the film unwinding rollers (14), the width of the stress change sensing film is greater than the length of the circuit board, a lamination mechanism (2) for tightly lapping the stress change sensing film on the circuit board is arranged above and below the welding station, a light source (3) and a high-definition camera (4) are arranged directly above the welding station, the high-definition camera (4) takes a picture of the circuit board before welding, and takes another picture of the circuit board after welding, and the color change of the stress change sensing film in the two pictures can be compared to know the stress change of the circuit board.

2. The inspection apparatus for soldering of a circuit board according to claim 1, characterized by: The lamination mechanism (2) comprises a movable frame (21), an upper support plate (22), a lower support plate (23), a translation air cylinder (24), a lifting air cylinder (25), an air extraction assembly (26) and a cutting assembly (27), the movable frame (21) is horizontally movably arranged on the mounting frame (1), the upper support plate (22) is vertically movably arranged on the movable frame (21), the lower support plate (23) is vertically movably arranged on the mounting frame (1), and the upper support plate (22) is arranged above the lower support plate (23), and the welding station is located between the upper support plate (22) and the lower support plate (23); A first abutting column (221) is arranged on one side of the upper support plate (22) close to the lower support plate (23) and corresponding to the hole punching position of the stress change sensing film, an avoiding groove is formed in the first abutting column (221) and corresponding to the position of the electronic component on the circuit board, and the diameter of the avoiding groove is the same as the diameter of the hole punching of the stress change sensing film, a second abutting column (231) is arranged on one side of the lower support plate (23) close to the upper support plate (22) and corresponding to the bolt hole of the circuit board, and an air extraction channel is formed in the second abutting column (231). The translation cylinder (24) is fixedly arranged on the mounting frame (1), and the telescopic end is connected with the movable frame (21), the lifting cylinder (25) is provided with two groups, two groups of the lifting cylinder (25) are respectively fixedly arranged on the movable frame (21) and the mounting frame (1), and the telescopic end is respectively connected with the side of the upper support plate (22) and the lower support plate (23) away from each other, the air extraction assembly (26) is arranged on the side of the lower support plate (23) away from the upper support plate (22), for extracting the air between the stress change sensing film and the circuit board through the bolt hole on the circuit board and the air extraction channel in the second abutting column (231), so that the circuit board and the stress change sensing film are tightly attached, the cutting assembly (27) is arranged on the movable frame (21), for cutting the stress change sensing film after the circuit board is coated.

3. A detection device for soldering of circuit boards according to claim 2, characterized in that: The air extraction assembly (26) includes an air extraction pump (261) and an air extraction pipe (262), the second abutting column (231) is provided with a plurality of groups, the lower support plate (23) is provided with an air extraction chamber, the air extraction channels in the plurality of second abutting columns (231) are communicated with the air extraction chamber, and the air extraction pump (261) is fixedly arranged on the side of the lower support plate (23) away from the upper support plate (22), and the air extraction end is communicated with the air extraction chamber through the air extraction pipe (262).

4. The inspection apparatus for soldering of a circuit board according to claim 2, characterized by: The cutting assembly (27) includes a transverse cutting blade (271) and a longitudinal cutting blade, the transverse cutting blade (271) and the longitudinal cutting blade are fixedly arranged on the side wall of the upper support plate (22), and the transverse cutting blade (271) and the longitudinal cutting blade are perpendicular to each other, the transverse cutting blade (271) and the longitudinal cutting blade are provided with two groups, two groups of the transverse cutting blade (271) are used for cutting two transverse edges of the stress change sensing film covered on the circuit board, and two groups of the longitudinal cutting blade are used for cutting two longitudinal edges of the stress change sensing film covered on the circuit board.

5. The inspection apparatus for soldering of a circuit board according to claim 1, characterized by: The length of the stress change sensing film covered on the circuit board is greater than the length of the circuit board, the mounting frame (1) is provided with a negative pressure cylinder (5), the telescopic end of the negative pressure cylinder (5) is provided with a negative pressure roller (51), the middle of the negative pressure roller (51) is hollow, and the negative pressure roller (51) is provided with a negative pressure hole, the mounting frame (1) is fixedly provided with a negative pressure air pump (52), the air extraction end of the negative pressure air pump (52) is provided with a negative pressure pipe (53), and one end of the negative pressure pipe (53) away from the negative pressure air pump (52) is communicated with the inside of the negative pressure roller (51).

6. The inspection apparatus for soldering of a circuit board according to claim 1, characterized by: The first electric telescopic rod (6) is fixedly arranged above the film unwinding roller (14), a first adjusting roller (61) is arranged on the telescopic end of the first electric telescopic rod (6), the second electric telescopic rod (7) is fixedly arranged above the film winding roller (15), a second adjusting roller (71) is arranged on the telescopic end of the second electric telescopic rod (7), and the first adjusting roller (61) and the second adjusting roller (71) are used for height adjustment of the stress change sensing film output by the film unwinding roller (14).

7. The inspection apparatus for soldering of a circuit board according to claim 2, characterized by: The clamping cylinder (8) is fixedly arranged on the movable frame (21), and a clamping frame (81) is arranged on the telescopic end of the clamping cylinder (8); when the clamping frame (81) and the second abutting column (231) abut against the circuit board, the clamping and fixing of the circuit board are realized.

8. A method for inspecting a soldered circuit board, according to the apparatus for inspecting a soldered circuit board according to claim 7, characterized by: The method comprises the following steps: S1: the circuit board is conveyed to the welding station by the first conveying roller (11) and the second conveying roller (12), the film unwinding roller (14) and the film winding roller (15) are started to convey the stress change sensing film to above the welding station, the first electric telescopic rod (6) and the second electric telescopic rod (7) are started to adjust the height of the stress change sensing film, and the stress change sensing film is preliminarily attached to the circuit board; S2: the translation cylinder (24) is started to move the upper support plate (22) to be directly above the lower support plate (23), the lifting cylinder (25) is started to abut against the upper support plate (22) and the lower support plate (23), the air pump (261) is started, the air pump (261) extracts the air between the circuit board and the stress change sensing film through the air extraction pipe (262) and the air extraction channel, the stress change sensing film is tightly attached to the circuit board, then the transverse cutting cylinder and the longitudinal cutting cylinder are started to drive the transverse cutting blade (271) and the longitudinal cutting blade to cut the stress change sensing film; S3: after the cutting is completed, the upper support plate (22) is moved away from above the lower support plate (23), the clamping cylinder (8) is started, the clamping and fixing of the circuit board are realized by abutting the clamping column and the second abutting column (231) against the circuit board, the light source (3) and the high-definition camera (4) are turned on to take a photo of the circuit board before welding; S4: the soldering gun is started to weld the circuit board, the high-definition camera (4) is started again to take a photo of the circuit board after the welding is completed, the color change of the stress change sensing film in the two photos is compared, and the stress change of the circuit board can be known; S5: when the stress change of the circuit board is not obvious, it indicates that the welding of the circuit board is qualified, at this time, the clamping column and the second abutting column (231) are separated from the circuit board, the first electric telescopic rod (6) is started to adjust the negative pressure roller (51) to a proper height, the circuit board is moved to the negative pressure roller (51) by the first conveying roller (11) and the second conveying roller (12), the negative pressure air pump (52) is started to make the end part of the stress change sensing film covering the circuit board be adsorbed on the negative pressure roller (51), and the stress change sensing film covering the circuit board can be torn off along with the continuous movement of the circuit board that has been welded.

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