PCBA Tech - About the causes and solutions of SMT material loss

The factors of SMT material loss, we can first make a detailed analysis through the man-machine material method as follows:

1. Human factors

1. When the material is loaded, the tearing tape is too long and the material is too much to lose and lose the material;

Solution: Train the operator to reserve two or three vacancies when loading the material, press the material to the material window to see the material OK, so that you can check the FEEDER gear position and the tape tension.

2. After FEEDER is installed, there are sundries on the TABLE which cause it to be out of place and shake and fail to fetch materials;

Solution: Train the operator to check the machine TABLE and FEEDER base for debris when installing FEEDER, and clean the machine TABLE when turning it.

3. The material tray is not installed on the FEEDER causing the chuck and FEEDER TAPE to float and throw materials;

Solution: It is strictly required that the operator must install the material tray on the FEEDER when changing the material.

4. Failure to remove the coiled material in time causes tension changes, non-coiling, poor feeding, and FEEDER TAPE floats and throws;

Solution: Strictly require the operator to clean the tape when changing the material

5. Loss caused by reversing the board, jumping the wrong board, wiping the board, etc.;

Solution: Strictly require the operator to operate according to the work instruction, and mark the position of the board, the direction of the board and the matters needing attention on the instruction book.

6. Wrong material location and P/N cause wrong material;

Solution: Train the operator to check the material P/N, the machine alarm display, and the position of the discharge table.

7. The quantity of materials is wrong, the PCBA is excessive, and the material tray is lost by mistake;

Solution: Require material staff to enter and exit all materials on the production line, PCBA must count the quantity and register on-duty to check the production quantity and the stock quantity.

8. The packaging parameters in the edited program are set incorrectly, and the number of feeding times used does not match the packaging PITCH, resulting in throwing;

Solution: Modify the PACKED DATA according to the material packaging.

9. Wrong placement and station setting in the edited program cause wrong material;

Solution: Check the BOM and drawings when doing the program, and re-check the BOM and drawings after posting the first inspection board.

10. During the production process, FEEDER, NOZZLE, and material throwing technicians failed to follow up the throwing material in time, and the data caused a large amount of throwing material;

Solution: It is required that the follow-up technicians must monitor the operating conditions of the machine in real time. When the machine alarms, it must be handled and observed on site. The hourly dumping report must be signed by the technician to confirm and write improvement measures. If the report has not been processed for two hours, the reason must be analyzed and reported to the assistant engineer for processing.

11. The feeder cover is not fastened, and the feeder is loaded without checking the feeder

Solution: require the operator to work according to WI requirements and check FEEDER before and after installation. Technician and management check and confirm.

12. FEEDER is randomly stacked to cause deformation, FEEDER STOPPER is randomly disassembled and placed in disorder;

Solution: The operator is required to place all FEEDER on the FEEDER car. It is strictly forbidden to stack or place it randomly, and it is strictly forbidden to dismantle FEEDER accessories randomly when following the line.

13. The bad FEEDER failed to be repaired and reused in time, resulting in throwing materials;

Solution: The operator is required to clearly identify all bad FEEDER and send it to the FEEDER repair station for repair and correction.

Second, the machine factor

1. The suction nozzle is deformed, blocked, damaged, insufficient vacuum pressure, and air leakage, causing the material to be sucked, incorrectly reclaimed, and the recognition fails and the material is thrown.

Solution: require technicians to check the equipment every day, test the NOZZLE center, clean the suction nozzle, and maintain the equipment regularly as planned.

2. Insufficient spring tension, uncoordinated suction nozzle and HOLD up and down, resulting in poor picking;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts.

3. Deformation of HOLD/SHAFT or PISTON, bending of the suction nozzle, and shortening of suction nozzle abrasion, resulting in poor material picking;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts.

4. The reclaiming material is not in the center of the material, and the reclaiming height is not correct (generally press 0.05MM after touching the part), resulting in deviation, incorrect reclaiming, offset, and identification inconsistent with the corresponding data parameters And the recognition system is discarded as invalid material;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts, and correct the origin of the machine.

5. The vacuum valve, the vacuum filter element is dirty, the vacuum tube is blocked by foreign matter, and the vacuum is not enough at the moment of suction, and the operating speed of the equipment causes poor feeding;

Solution: require technicians to clean the suction nozzle every day and maintain the equipment regularly as planned.

6. The positioning of the machine is not horizontal and the vibration is large, and the resonance of the machine and the FEEDER causes poor reclaiming;

Solution: Regularly maintain the equipment as planned, and check the level of the equipment to fix the support nuts.

7. The screw and bearing are worn and loosened, causing vibration and stroke changes during operation, resulting in poor material picking;

Solution: It is strictly forbidden to blow the inside of the machine with an air gun to prevent dust, debris, and components from sticking to the screw. Regularly maintain the equipment as planned, check and replace vulnerable parts.

8. Motor bearing wear, barcode reader and amplifier aging cause the machine origin to change, operating data is inaccurate and poor material retrieval;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts, and correct the origin of the machine.

9. The vision, laser lens, and suction nozzle reflective paper are not clean, and there are debris that interferes with the camera's recognition and causes poor processing;

Solution: require technicians to check the equipment every day, test the NOZZLE center, clean the suction nozzle, and maintain the equipment regularly as planned.

10. Identifies the improper selection of light source, aging of the luminous intensity of the lamp, and insufficient gray scale, resulting in poor processing;

Solution: Regularly maintain the equipment as planned, test the brightness of the camera and the brightness of the lamp, check and replace vulnerable parts.

11. Poor handling caused by aging of the reflective prisms, carbon deposits, abrasion and scratches;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts.

12. Insufficient air pressure, leakage of vacuum caused insufficient air pressure and the material could not be retrieved, or it fell off on the way after picking it up;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts.

13. The feeder gland is deformed and the spring tension is not enough, causing the material tape to not be stuck on the ratchet wheel of the feeder, and the tape is not thrown away;

Solution: The operator is required to clearly identify all bad FEEDER and send it to the FEEDER repair station for repair, correction, inspection and replacement of vulnerable parts.

14. Camera loosening and aging cause poor recognition and throwing materials;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts.

15. Feeder ratchet gears, driving claws, positioning claws are worn, electrical failures, and feeding motors are poor, causing the feeder to feed poorly, or poorly, and throwing materials;

Solution: require the operator to clearly identify all bad FEEDER and send it to the FEEDER repair station for repair, correction, inspection and replacement of vulnerable parts

16. The wear of the machine's feeding platform causes FEEDER to become loose after installation and poor feeding;

Solution: Regularly maintain the equipment as planned, check and replace vulnerable parts.

3. Material reasons

1. Unqualified products such as dirty, damaged, irregular incoming materials, and lead oxidation cause poor identification.

Solution: feedback IQC to communicate with suppliers to replace materials.

2. The components are magnetized, the components are packaged too tightly, and the material frame has too much friction on the components, which makes it impossible to absorb them.

Solution: feedback IQC to communicate with suppliers to replace materials.

3. The component size or package size, spacing, and direction are not uniform to cause poor picking and poor recognition.

Solution: feedback that IQC communicates with the supplier to replace the material, and the packaging and body shape of the same P/N material must be checked when the material is received.

4. The components are magnetized and the material tape is too viscous, and the material adheres to the material tape when the tape is wound.

Solution: feedback IQC to communicate with suppliers to replace materials.

5. The suction surface of the PCBA component is too small, resulting in poor material picking.

Solution: Feed back IQC to communicate with suppliers to replace materials and reduce machine operation speed.