A highly intensive Mini LED soldering joint inspection device and method

Abstract

The present invention provides a highly dense Mini LED soldering joint inspection device, belonging to the technical field of Mini LED soldering joint inspection; the technical problem to be solved is: to provide an improvement in the hardware structure of a highly dense Mini LED soldering joint inspection device; the technical solution adopted to solve the above technical problem is: including a rolling device, a vibration device, and a lighting test device. The rolling device, the vibration device, and the lighting test device are all arranged on the same detection platform, and the rolling device, the vibration device, and the lighting test device are connected by a conveyor belt and conveyor rollers; the rolling device includes rollers, two transmission shafts, a chain, and a positioning device. The positioning device is placed below the rollers. The two ends of the rollers and the two ends of the two transmission shafts are respectively connected to the same connecting plate. Among them, the rollers are arranged below the two transmission shafts, and the two ends of the two transmission shafts are respectively connected to the chains on the two side supports. Fixed screws are respectively arranged at both ends above the supports; the present invention is applied to Mini LED soldering joint inspection.

Description

Technical Field

[0001] The present invention provides a highly dense Mini LED soldering inspection device and method, belonging to the technical field of highly dense Mini LED soldering inspection. Background Art

[0002] Currently, the traditional methods for inspecting component soldering are mainly as follows: 1. Visual inspection, or inspection with the aid of devices such as magnifying glasses and microscopes to check problems such as insufficient solder, cracks, and non-wetting of solder at the solder joints; 2. Using a dedicated on-line inspection device - a bed of needles for inspection. The bed of needles, also called an ICT inspection fixture, is a non-standard test auxiliary fixture that tests on-line components through electrical performance to check manufacturing defects and component defects, and can also be used to test soldering problems; 3. X-Ray equipment, which checks soldering problems through X-ray images.

[0003] Among them, visual inspection or inspection with the aid of devices such as magnifying glasses and microscopes involves checking each component one by one, and the recognition of vertical soldering is not sufficient; while using a dedicated on-line inspection device mainly detects complex circuits involving different types of components through electrical performance, and the detection accuracy can only reach the millimeter level; the X-Ray inspection device can check various soldering problems with relatively high accuracy, but the equipment cost is very high. For display modules, the density of MiniLED is very high, and the above three methods cannot quickly and efficiently detect micron-level Mini LED soldering. Summary of the Invention

[0004] In order to overcome the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an improvement in the hardware structure of a highly dense Mini LED soldering inspection device.

[0005] To solve the above technical problem, the technical solution adopted by the present invention is: a highly dense Mini LED soldering inspection device, including a rolling device, a vibration device, and a lighting test device. The rolling device, the vibration device, and the lighting test device are all arranged on the same detection platform, and the rolling device, the vibration device, and the lighting test device are connected by a conveyor belt and conveyor rollers;

[0006] The rolling device includes rollers, two drive shafts, a chain, and a positioning device. The positioning device is placed below the rollers. The two ends of the rollers and the two ends of the two drive shafts are respectively connected to the same connecting plate. Among them, the rollers are arranged below the two drive shafts, and the two ends of the two drive shafts are respectively connected to the chains on the two side supports. Fixing screws are respectively arranged at the two ends above the supports;

[0007] The vibration device includes a vibration table disposed on the detection platform, and the lighting test device includes a lighting test table disposed on the detection platform.

[0008] A platform for placing a carrier is disposed on the conveyor belt on one side in front of the rolling device. The carrier conveys the PCB board placed on the carrier to the rolling device through the conveyor belt for rolling test. After the rolling test is completed, the PCB board is conveyed to the vibration device through the conveying roller for vibration test. After the vibration test is completed, the PCB board is conveyed to the lighting test device through the conveying roller for LED lighting test.

[0009] A guiding inlet is disposed on the platform for placing the carrier.

[0010] The roller includes an inner core and a rotating bearing. Both ends of the rotating bearing pass through the inner core of the round shaft and extend out.

[0011] The inner core is an aluminum alloy round shaft. The concentricity between the aluminum alloy round shaft and the rotating bearing is <0.01 mm. The outer ring of the aluminum alloy round shaft is wrapped with silica gel with a Shore hardness of 10 degrees, and the thickness of the silica gel is 0.5 - 2 mm.

[0012] The fixing screws are fixing screws with springs. The height of the roller and the rolling flatness are adjusted by adjusting the depth of each fixing screw.

[0013] The positioning device includes a positioning platform. Two transmission wheels are disposed on the positioning platform. Positioning claws are disposed on the four sides of the positioning platform. Four corner columns are disposed at the four corners of the bottom of the positioning platform. One end of the four corner columns is fixed to the bottom of the positioning platform, and the other end of the four corner columns passes through the detection platform. Electric push rods are disposed at the bottoms of the four corner columns.

[0014] A limiting strip is further disposed on the rolling device, and the limiting strip is disposed inside the support frame below the roller.

[0015] A highly dense Mini LED open circuit detection method includes the following steps:

[0016] S1: Place a PCB empty board without mounted Mini LED chips on the carrier, and convey it to the positioning device below the roller through the conveyor belt. After the positioning device accurately positions the carrier and the PCB and jacks them up to the limiting strips on both sides of the roller, adjust the distance between the roller and the PCB empty board to 1 / 3 of the chip height through the fixing screws with springs on both sides of the support frame. Find 3 - 5 points and use a feeler gauge to test the rolling flatness of the roller and perform calibration.

[0017] S2: After calibration, the positioning device is lowered by program control, and the carrier and the PCB empty board are taken out.

[0018] S3: Place the PCB with Mini LED chips mounted and passed through reflow soldering on the carrier;

[0019] S4: Place the carrier and the entire PCB on the conveyor belt on the front side in front of the rolling device according to the guiding inlet;

[0020] S5: The conveyor belt transports the PCB with the carrier to the positioning device, and the protruding driving wheels of the positioning device move the PCB directly above the positioning platform. The program controls the four corner columns to lift the positioning platform to the limiting platforms on both sides of the rollers, and at the same time, the positioning claws position the PCB;

[0021] S6: The program controls the rollers to move from the rear end to roll to the front end, and then roll from the front end to the rear end;

[0022] S7: After one round trip of rolling, some of the poorly soldered chips will completely break away from the PCB pads and be taken away by the silicone on the rollers;

[0023] S8: The program controls the positioning device to lower, and the conveyor rollers send the PCB to the vibrating table, and vibrate the PCB for 2 minutes according to the set vibration amplitude and frequency;

[0024] S9: Transport the PCB to the lighting test device for lighting test.

[0025] It also includes S10: The detection device records the positions of all the unlit chips and sends them to the repair equipment.

[0026] The flatness of the carrier is 0.05 - 0.2 mm, and the flatness of the rolling device is 0.05 - 0.2 mm.

[0027] The beneficial effects of the present invention compared with the prior art are as follows: Through the detection device and method of the present invention, regarding the problem of poor soldering of Mini LED chips in the COB - packaged small - pitch display module, it gets rid of the traditional visual inspection methods using the naked eye or magnifying glasses and microscopes, as well as the high - precision radiography detection method of X - ray detection equipment. Instead, it applies a certain external force to the chips with a high - precision rolling device made of special materials, and through vibration, the poorly soldered chips are completely separated from the pads. Then, the lighting test device records the positions of the unlit chips (poorly soldered chips) and shares them with the repair equipment. This method can quickly and efficiently detect and screen the problem of poor soldering of the highly dense Mini LED chips on the COB - packaged small - pitch display module. Brief Description of the Drawings

[0028] The following further describes the present invention with reference to the drawings:

[0029] Figure 1 It is the overall structural schematic diagram of the detection device of the present invention;

[0030] Figure 2 Schematic structural diagram of the rolling device of the present invention;

[0031] Figure 3 Schematic structural diagram of the roller of the present invention;

[0032] Figure 4 Schematic structural diagram of the height of the roller of the present invention;

[0033] Figure 5 Schematic diagram of adjusting the height and rolling flatness of the roller with the PCB hole plate of the present invention;

[0034] Figure 6 Schematic diagram of positioning the PCB with the positioning device of the present invention;

[0035] Figure 7 、 Figure 8 Schematic diagram of the roller of the present invention rolling the chips on the PCB from back to front and from front to back respectively;

[0036] Figure 9 Schematic exploded sectional view of the rolling device and the positioning device of the present invention;

[0037] Figure 10 Schematic diagram of the desoldered chips being adhered and carried away by the silicone roller after rolling of the present invention;

[0038] In the figure: 1 is the rolling device, 2 is the vibration device, 3 is the lighting test device, 4 is the carrier, 5 is the empty PCB board, 6 is the positioning device, 7 is the LED chip, 8 is the conveyor belt, 9 is the conveyor roller, 101 is the transmission shaft, 102 is the chain, 103 is the fixing screw, 104 is the roller, 105 is the support frame, 106 is the limiting strip, 201 is the inner core, 202 is the silicone, 203 is the rotary bearing, 601 is the PCB with the carrier, 602 is the driving wheel, 603 is the positioning platform, 604 is the four-corner column, 605 is the positioning claw. Detailed implementation manners

[0039] As Figures 1-10 shown, a highly dense Mini LED virtual soldering detection device of the present invention includes a rolling device 1, a vibration device 2, and a lighting test device 3. The rolling device 1, the vibration device 2, and the lighting test device 3 are all arranged on the same detection platform. The rolling device 1, the vibration device 2, and the lighting test device 3 are connected by a conveyor belt 8 and a conveyor roller 9;

[0040] The rolling device 1 includes a roller 104, two transmission shafts 101, a chain 102, and a positioning device 6. The positioning device 6 is placed below the roller 104. The two ends of the roller 104 and the two ends of the two transmission shafts 101 are respectively connected to the same connecting plate. Among them, the roller 104 is arranged below the two transmission shafts 101. The two ends of the two transmission shafts 101 are respectively connected to the chains 102 on both sides of the support frame 105. Fixed screws 103 are respectively arranged at both ends above the support frame 105;

[0041] The vibration device 2 includes a vibration table arranged on the detection platform, and the lighting test device 3 includes a lighting test table arranged on the detection platform.

[0042] A platform for placing the carrier 4 is arranged on the conveyor belt 8 on one side in front of the rolling device 1. The carrier 4 conveys the PCB board placed on the carrier to the rolling device 1 through the conveyor belt 8 for rolling test. After the rolling test is completed, the PCB board is conveyed to the vibration device 2 through the conveying roller 9 for vibration test. After the vibration test is completed, the PCB board is conveyed to the lighting test device 3 through the conveying roller 9 for LED lighting test.

[0043] A guiding inlet is arranged on the platform for placing the carrier 4.

[0044] The roller 104 includes an inner core 201 and a rotary bearing 203. The two ends of the rotary bearing 203 pass through the circular shaft inner core 201 and extend out;

[0045] The inner core 201 is an aluminum alloy circular shaft. The concentricity between the aluminum alloy circular shaft and the rotary bearing 203 is <0.01 mm. The outer ring of the aluminum alloy circular shaft is wrapped with silica gel 203 with a Shore hardness of 10 degrees, and the thickness of the silica gel is 0.5 - 2 mm.

[0046] The fixed screw 103 uses a fixed screw with a spring. The height of the roller 104 and the rolling flatness are adjusted by adjusting the depth of each fixed screw 103.

[0047] The positioning device 6 includes a positioning platform 603. Two transmission wheels 602 are arranged on the positioning platform 603. Positioning claws 605 are arranged on the four sides of the positioning platform 603. Four-corner columns 604 are arranged at the four corners of the bottom of the positioning platform 603. One end of the four-corner column 604 is fixed to the bottom of the positioning platform 603, and the other end of the four-corner column 604 passes through the detection platform. An electric push rod is arranged at the bottom of the four-corner column 604.

[0048] A limit bar 601 is further arranged on the rolling device 1, and the limit bar 601 is arranged inside the support frame 105 below the roller 104.

[0049] The device of the present invention mainly performs external force intervention and detection screening on the virtual soldering problem of Mini LED chips in the COB packaged small-pitch display module after reflow soldering. It is different from the traditional vision detection method. It mainly consists of a rolling device 1, a vibration device 2, and a lighting test device 3. The main component of the rolling device 1 is a special roller 104. The inner core 201 of the roller 104 is an aluminum alloy round shaft. The concentricity between the roller 104 and the rotary bearing 203 is <0.01 mm. The outer ring of the aluminum alloy round shaft is wrapped with silica gel 202 with a Shore hardness of 10 degrees. The thickness of the silica gel 202 is 0.5 - 2 mm. In this embodiment, the thickness of the silica gel is 1 mm. The circumference of the silica gel 202 is slightly larger than the length of the module in the rolling direction. The roller 104 is connected to the two upper drive shafts 101. Driven by the chain 102, the drive shafts 101 drive the roller 104 to move and rotate to roll the Mini LED chips on the PCB. Above the two support frames 105 on both sides of the drive shaft 101, there are four fixing screws 103 with springs each. The height and rolling flatness of the roller 104 can be adjusted by adjusting the depth of each fixing screw 103, so that the part of the chip embedded in the silica gel 202 accounts for about 2 / 3 of the total height of the chip as Figure 4 shown. After the roller 104 rolls back and forth, the chip will be subjected to the extrusion thrust of the silica gel of the roller in the front and back directions. The soft silica gel surface itself also has a slight adhesive force. Some virtual soldered chips will break away from the solder pad and be carried away by the adhesion of the silica gel of the roller 104 after being stressed. Another part of the virtual soldered chips will become loose after being stressed and will break away from the solder pad after vibration and will also be screened out after lighting test.

[0050] The specific detection method of the present invention is as follows:

[0051] 1. Place a PCB empty board 5 without mounted Mini LED chips on the carrier 4. The flatness of the carrier 4 is between 0.05 - 0.2 mm. In this embodiment, the flatness of the carrier 4 is 0.1 mm. It is conveyed by the conveyor belt 8 to the positioning device 6 under the roller 104. After the positioning device 6 accurately positions the carrier 4 and the PCB, it jacks them up to the limit strips 106 on both sides of the roller 104. Adjust the distance between the roller 104 and the PCB empty board 5 to about 1 / 3 of the chip height through the fixing screws 103 with springs on both sides of the support frame 105. Find 3 - 5 points and use a feeler gauge to test the rolling flatness of the roller and adjust it so that the flatness is between 0.05 - 0.2 mm (this flatness is based on 1 / 3 of the chip height);

[0052] 2. After the adjustment is completed, the positioning device 6 is lowered by program control, and the carrier 4 and the PCB empty board 5 are taken out;

[0053] 3. Place the PCB with mounted Mini LED chips and after reflow soldering on the carrier 4;

[0054] 4. Place the vehicle 4 and the entire PCB on the conveyor belt 8 in front of the rolling device 1 according to the guiding inlet;

[0055] 5. The conveyor belt 8 conveys the PCB 601 with the vehicle to the positioning device 6, and the protruding driving wheel 602 of the positioning device 6 moves the PCB to directly above the positioning platform 603 (at this time, the positioning platform 603 and the positioning claws 605 are in the lowered state). The program controls the four-corner columns 604 to lift the positioning platform 603 to the limit strips 106 on both sides of the rollers 104, and at the same time, the positioning claws 605 position the PCB;

[0056] 6. The program controls the rollers 104 to move from the rear end to roll to the front end as Figure 7 , and then roll from the front end to the rear end as Figure 8 . The sectional decomposition diagram of the rolling device 1 and the positioning device 6 is as Figure 9 shown;

[0057] 7. After one round-trip rolling, some of the poorly soldered chips will completely break away from the PCB pads and be taken away by the silica gel on the rollers as Figure 10 , and the remaining poorly soldered chips will also become loose after being rolled by the rollers;

[0058] 8. The program controls the positioning device 6 to lower, and the conveyor rollers 9 send the PCB to the vibrating table, and vibrate the PCB for 2 minutes according to the set vibration amplitude and frequency. At this time, the chips loosened by rolling will fully break away from the pads;

[0059] 9. Send the PCB to the lighting test device for lighting test;

[0060] 10. The test device will record the positions of all non-lighting chips and share them with the maintenance equipment.

[0061] A control box is provided below the rolling device 1 of the present invention. There is a controller inside the control box. The controller controls the control ends of the motor connected to the conveyor rollers, the motor of the gear connected by the chain, and the electric push rod of the four-corner columns, controls the movement of the conveyor rollers to drive the conveyor belt to rotate, realizes the sequential movement of the PCB on the rolling device 1, the vibrating device 2, and the lighting test device 3, controls the rotation of the gear to drive the movement of the chain, drives the movement of the transmission shaft on the chain, and finally makes the rollers move back and forth, controls the up and down movement of the electric push rod to drive the up and down movement of the four-corner columns, so as to lift or lower the positioning platform.

[0062] A vibrating motor is provided below the vibrating device 2 of the present invention, and the control end of the vibrating motor is also connected to the controller. A lighting test circuit board is provided below the lighting test device 3. During the test, the lighting test circuit board is connected to the PCB board of the LED to be detected, and the lighting test is carried out row by row or column by column.

[0063] Regarding the specific structure of the present invention, it should be noted that the connection relationships between the various component modules adopted by the present invention are determined and achievable. Except for the special descriptions in the embodiments, the specific connection relationships can bring corresponding technical effects and, on the premise of not relying on the execution of corresponding software programs, solve the technical problems proposed by the present invention. The models and connection methods of the components, modules, and specific components in the present invention, except for the specific descriptions, all belong to the prior art such as publicly available patents, publicly available journal papers, or common general knowledge that those skilled in the art can obtain before the filing date, and need not be elaborated. This makes the technical solution provided in this case clear, complete, and achievable, and can reproduce or obtain the corresponding physical product based on this technical means.

[0064] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly dense Mini LED soldering joint inspection device, characterized in that: It includes a rolling device, a vibration device, and a lighting test device. The rolling device, vibration device, and lighting test device are all arranged on the same detection platform, and the rolling device, vibration device, and lighting test device are connected by a conveyor belt and conveyor rollers; The rolling device includes rollers, two transmission shafts, a chain, and a positioning device. The positioning device is placed under the rollers. The two ends of the rollers and the two ends of the two transmission shafts are respectively connected to the same connecting plate. Among them, the rollers are arranged under the two transmission shafts, and the two ends of the two transmission shafts are respectively connected to the chains on the two side supports. Fixed screws are respectively arranged at the two ends above the supports; The vibration device includes a vibration table arranged on the detection platform, and the lighting test device includes a lighting test table arranged on the detection platform; The rollers include an inner core and a rotary bearing. The two ends of the rotary bearing pass through the circular shaft inner core and extend out; the outer ring of the inner core is wrapped with silica gel.

2. The highly dense Mini LED soldering defect detection device according to claim 1, characterized in that: A platform for placing the carrier is arranged on the conveyor belt on one side in front of the rolling device. The carrier conveys the PCB board placed on the carrier to the rolling device through the conveyor belt for rolling test. After the rolling test is completed, the PCB board is conveyed to the vibration device through the conveyor rollers for vibration test. After the vibration test is completed, the PCB board is conveyed to the lighting test device through the conveyor rollers for LED lighting test.

3. The highly dense Mini LED soldering joint inspection device according to claim 2, wherein: A guiding entrance is arranged on the platform for placing the carrier.

4. A highly dense Mini LED soldering defect detection device according to claim 1, characterized in that: The inner core is an aluminum alloy circular shaft. The concentricity between the aluminum alloy circular shaft and the rotary bearing is <0.01 mm. The outer ring of the aluminum alloy circular shaft is wrapped with silica gel with a Shore hardness of 10 degrees, and the thickness of the silica gel is 0.5 - 2 mm.

5. A highly dense Mini LED soldering joint inspection device according to claim 1, characterized in that: The fixed screws adopt fixed screws with springs, and the height of the rollers and the rolling flatness are adjusted by adjusting the depth of each fixed screw.

6. A highly dense Mini LED soldering joint inspection device according to claim 1, characterized in that: The positioning device includes a positioning platform. There are two driving wheels arranged on the positioning platform. There are positioning claws arranged on the four sides of the positioning platform. Four corner columns are arranged at the four corners of the bottom of the positioning platform. One end of the four corner columns is fixed to the bottom of the positioning platform, and the other end of the four corner columns passes through the detection platform. An electric push rod is arranged at the bottom of the four corner columns.

7. A highly dense Mini LED soldering defect detection device according to claim 1, characterized in that: A limiting strip is also arranged on the rolling device, and the limiting strip is arranged on the inner side of the support under the rollers.

8. A highly dense Mini LED solder joint inspection method, which uses the highly dense Mini LED solder joint inspection device described in any one of claims 1-7, and is characterized in that: It includes the following steps: S1: Place a PCB empty board without mounted Mini LED chips on the carrier, and convey it to the positioning device under the rollers by the conveyor belt. After the positioning device accurately positions the carrier and the PCB and jacks it up to the limiting strips on both sides of the rollers, adjust the distance between the rollers and the PCB empty board to 1 / 3 of the chip height by the fixed screws with springs on both sides of the support. Find 3 - 5 points and use a feeler gauge to test the rolling flatness of the rollers and perform calibration; S2: After the calibration is completed, the positioning device is lowered by program control, and the carrier and the PCB empty board are taken out; S3: Place the PCB with mounted Mini LED chips and passed through reflow soldering on the carrier; S4: Place the carrier and the PCB as a whole into the conveyor belt on one side in front of the rolling device according to the guiding entrance; S5: The conveyor belt transports the PCB with the carrier to the positioning device, and the protruding driving wheels of the positioning device are used to move the PCB directly above the positioning platform. The program controls the four corner columns to lift the positioning platform to the limiting platforms on both sides of the rollers, and at the same time, the positioning claws position the PCB. S6: The program controls the rollers to move from the rear end to roll press to the front end, and then roll press from the front end to the rear end. S7: After the round-trip rolling, some of the poorly soldered chips will completely break away from the PCB pads and be taken away by the silica gel on the rollers. S8: The program controls the positioning device to lower, and the conveyor rollers send the PCB to the vibrating table, and the PCB is vibrated for 2 minutes at the set vibration amplitude and frequency. S9: The PCB is transported to the lighting test device for lighting test.

9. A highly dense Mini LED soldering joint inspection method according to claim 8, characterized in that: It further includes S10: The detection device records the positions of all non-lighting chips and sends them to the repair equipment.

10. A highly dense Mini LED soldering joint inspection method according to claim 8, characterized in that: The flatness of the carrier is 0.05 - 0.2 mm, and the flatness of the rolling device is 0.05 - 0.2 mm.

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