Precision PCB Fabrication, High Frequency PCB, High Speed PCB, Standard PCB, Multilayer PCB and PCB Assembly.
The most reliable PCB custom service factory.
PCBA Tech
Causes and Solutions of Material Loss in PCBA Manufacturing
PCBA Tech
Causes and Solutions of Material Loss in PCBA Manufacturing

Causes and Solutions of Material Loss in PCBA Manufacturing

2021-12-10
View:79
Author:pcb

The factors that exist in the material loss of SMT in PCBA factory can be comprehensively analyzed through people, machines, materials and rings as follows:

A, human factors

1. Material loss caused by too long tearing band and too much pressing when installing materials by relevant technical operators of SMT patch processing;

Solution: PCBA manufacturer carries out professional technical operation training for SMT technicians. When SMT technicians are loading, two or three spaces are reserved. The material OK is seen in the pressing window, so that FEEDER gear position and roll tension can be checked.

2. Impurities on TABLE after FEEDER installation cause inadequate positioning and cannot be taken out when shaking;

Solution: PCBA manufacturer carries out professional technical training for SMT technicians SMT technicians when installing FEEDER to check if there is any impurities in the machine TABLE and FEEDER base, and clean the machine TABLE when pulling.

3. The material tray of SMT equipment is not installed on FEEDER, which causes the disc and FEEDER TAPE to float and throw high;

Solution: PCBA manufacturers need to strictly require SMT technicians to load the material tray onto FEEDER when changing materials.

4. Failure to remove the coil belt in time causes tension change, no coiling, poor feeding, FEEDER TAPE floating high throwing;

Solution: PCBA manufacturers strictly require operators to clean the rollers when changing materials

5. Loss caused by putting back boards, jumping boards, wiper boards, etc.

Solution: The SMT patch processing factory strictly requires SMT technical operators to operate according to the operation instructions, which indicate the position of the puzzle, the direction of entering the board and the precautions.

6. Looking at the wrong material station or P/N causes errors;

Solution: PCBA processing plant needs to train SMT technical operators to check material P/N, machine alarm display, and discharging table location.

7. Incorrect quantity of materials, excessive PCBA, misused material pallets are lost;

Solution: Require the material crew to check the production quantity and the deposited quantity of all materials, PCBA and PCBA in production line.

8. Wrong packaging parameters are set in the program edited, and the number of feeds used does not match the packing PITCH, causing throwing;

Solution: Modify PACKED DATA according to material packaging.

9. Errors in mounting position and station setting in the program edited by SMT technical operator before SMT patch processing operation cause errors.

Solution: Check BOM and drawings while doing the program, and stick out the first checkboard to reconfirm the BOM and drawings.

10. FEEDER, NOZZLE and material reason throwing technicians did not follow up the throwing and data caused a lot of throwing during the PCBA processing and production process.

Solution: Require SMT patch processing and on-line technicians to monitor the running status of the machine in real time, and to process and observe on the spot when the machine alarms. The hourly throwing report must be signed by SMT technicians to confirm and write improvement measures. If there is a signature to confirm that the two-hour unprocessed report must be resolved and reported to the assistant engineer for processing.

11. Feeder lid is not fastened properly, feed is not checked

Solution: Smt film factory requires SMT technical operator to work according to WI requirements, check FEEDER before and after installation, technicians and management check and confirm.

12. FEEDER casually overlaps causing distortion, FEEDER STOPPER casually disassembles and puts in disorder;

Solution: SMT technicians must be required to place all FEEDERs in the FEEDER car. No overlapping, random placement and disassembly of FEEDER accessories are allowed in the following line.

13. Bad FEEDER is not sent for repair and reuse in time, causing throwing;

Solution: PCB Factory requires SMT technical operator to clearly identify all bad FEEDER and send it to FEEDER repair station for repair and correction.

PCBA

B. Machine Factors

1. The nozzle is distorted, clogged, damaged, low vacuum pressure, and leaks air, which causes material not to be sucked up, material not to be taken correctly, recognition fails and material is thrown out.

Solution: PCBA processing plant requires Shenzhen SMT technicians to check SMT equipment daily, test NOZZLE center, clean nozzle, and maintain SMT equipment regularly according to plan.

2. Insufficient spring tension and inconsistency between nozzle and HOLD result in bad feeding;

Solution: Maintain SMT devices regularly according to schedule, check and replace fragile accessories.

3. Deformation of HOLD/SHAFT or PISTON, bending of nozzle and shorter wear and tear of nozzle result in bad feeding;

Solution: SMT shop equipment of PCBA manufacturer regularly maintains the equipment as scheduled, checks and replaces the fragile accessories.

4. The material is not in the center of the material, and the height of the material is incorrect (generally 0.05MM is the lowest pressure after encountering the part), which causes offset, incorrect and offset. When identifying, it is discarded as invalid material by the identifying system because it does not match the corresponding data parameters.

Solution: PCBA manufacturers regularly maintain SMT devices as scheduled, check and replace fragile accessories, and correct machine origin.

5. Vacuum valves, dirty vacuum filter cartridges, foreign objects blocking the vacuum tracheal passage are not smooth, and the vacuum is not sufficient at the moment of suction to make the SMT device run at a speed that results in bad feeding;

Solution: PCBA manufacturer requires SMT technicians to clean nozzles every day and regularly maintain SMT equipment as scheduled.

6. Large vibration due to non-horizontal positioning of the machine and resonance between the machine and FEEDER result in bad feeding;

Solution: Smt shop regularly maintains the equipment as scheduled and checks the horizontal fixing support nuts of the equipment.

7. Loose wear and tear of the screw rod and bearing cause vibration during operation, change of travel and poor material extraction.

Solution: It is strictly forbidden to use the inside of the windgun blowing machine to prevent dust, impurities and components from sticking to the screw rod. Smt shop regularly maintains SMT equipment and inspects and replaces the fragile accessories according to the plan.

8. Wear of motor bearings, aging of reader and amplifier cause machine origin change, inaccurate operation data and poor material collection;

Solution: PCBA manufacturers regularly maintain SMT devices as scheduled, check and replace fragile accessories, and correct machine origin.

9. The vision, laser lens, nozzle reflective paper are not clean, and impurities interfere with the camera identification causing poor handling;

Solution: SMT technicians are required to check SMT equipment daily, test NOZZLE center, clean nozzle, and maintain SMT equipment regularly according to schedule.

10. The improper selection of light source, aging light intensity of lamp and insufficient gray level cause poor treatment.

Solution: Shenzhen Patch Processing PCBA manufacturer regularly maintains SMT equipment as scheduled, tests the brightness of camera and lamp, checks and replaces fragile accessories.

11. Reflective prism ageing coke deposit, wear and scratch cause poor treatment;

Solution: PCBA manufacturers regularly maintain SMT devices as scheduled, check and replace fragile accessories.

12. Insufficient air pressure, leakage of vacuum causes insufficient air pressure and cannot be picked up or dropped on the way to paste.

Solution: PCBA manufacturers regularly maintain SMT devices as scheduled, check and replace fragile accessories.

13. The deformation of the cover of the feeder and the insufficient spring tension cause the belt not to be stuck on the spindle gears of the feeder and not to be rolled and thrown.

Solution: SMT processing plant requires SMT technical operator to clearly identify all bad FEEDERs and send them to FEEDER repair station for repair, correction, inspection and replacement of fragile accessories.

14. Bad discerning throws caused by camera loosening and aging;

Solution: PCBA Shiyan Patch Factory regularly maintains SMT equipment as scheduled, checks and replaces fragile accessories.

15. The screw gears, driving claws, positioning claws of the feeder are worn out, the electricity is not good, and the feeding motor is not good, which causes the feeder to fail to get or throw away.

Solution: Shenzhen SMT patch processing factory requires SMT technicians to clearly identify all bad FEEDERs and send them to FEEDER repair station for repair, correction, inspection and replacement of fragile parts

16. Wear and tear of machine feeding platform of SMT technology equipment results in loose FEEDER after installation and poor feeding;

Solution: Maintain SMT devices regularly according to schedule, check and replace fragile accessories.


C. Material Reasons

1. Unqualified products such as dirty, damaged components, irregular incoming materials and pin oxidation cause poor recognition.

Solution: Feedback IQC to communicate with supplier to replace materials.

2. Component magnetization, component packaging is too tight, material frame has too much friction to absorb components.

Solution: Feedback IQC to communicate with supplier to replace materials.

3. Various dimensions, spacing and orientation of components or packages may result in poor material extraction and identification.

Solution: Feedback IQC communicates with supplier to replace materials. When incoming materials, the packaging and body shape of the same P/N material must be checked.

4. Component magnetization and tape stickiness are too strong. When winding tape, the material sticks to the tape.

Solution: Personnel in charge of related jobs in PCBA factories feedback IQC to communicate with suppliers to replace materials.

5. The element suction surface is too small to cause bad material extraction.

Solution: Feedback IQC to communicate with supplier to change materials, reduce machine speed.

6. The material aperture of the filling element is too large, and the size of the element does not match the packaging size, resulting in side-up, flip, incorrect position and bad feeding.

7. The error between the feed hole and the feed hole of the material belt is large, and the suction position changes after changing the material.

8. The tension of the coil tape varies from one to another, and it is too soft to stretch without coiling. It is too crisp and easy to pull away.

9. The incoming packing is not standard and the bulk cannot be mounted by the machine.

Solution: Shiyan Patch Factory feedback IQC to communicate with supplier to replace materials.


D. Methods of Operation

1. Wrong use of different packaging models FEEDER, tape grooves, tape flat grooves cause material not to be retrieved;

Solution: Train SMT technical operators to identify material packaging and FEEDER selection.

2. Use wrong FEEDER of different specifications, 0802 FEEDRE for 0603 materials, 0804FEEDER for 0402 materials, 1.3MM for 0603 materials, 1.0MM for 0402 materials, 1.0MM for 0805 materials, and 1.0MM for adjustment FEEDERPITCH to make materials not available;

Solution: PCBA manufacturer trains SMT technicians to identify the size, shape and FEEDER cap selection of materials.

3. Smt technical operators of PCBA factories do not work according to the standard of operation instructions.

Solution: The PAC board manufacturer strictly requires SMT technicians to work according to the standard operation instructions, periodically assess their operational skills, and manage supervision and evaluation.

4. Bad feeding, bending of tape, too tight tension of coil tape and hole in tape cause bad feeding for the upper gear;

Solution: PCB factory strictly requires SMT technicians to work according to the standard operation instructions, train and assess operation skills, and manage supervision and evaluation.

5. Insufficient tension on the coil tape, and not installing the coil tape according to the standard causes no coil tape;

Solution: SMt chip processing factory strictly requires SMT technical operators to work according to the standard operation instructions, train and assess operation skills, and manage supervision and evaluation.

6. There is a space after the installation of the materials, which causes the materials to be not retrieved.

Solution: The SMT film factory strictly requires SMT technicians to work according to the standard operation instructions, train examination and operation skills, and manage supervision and evaluation.


E. Production environment

1. High temperature and insufficient humidity in SMT workshop cause dust and static electricity in material drying.

Solution: PCBA real-time monitoring of temperature and humidity in the shop, increase air conditioning and humidifier.

2. Warehouses in workshops and SMT film factories have high humidity, and materials absorb water from the air, which causes poor material extraction.

Solution: PCBA real-time monitoring of temperature and humidity in the workshop and warehouse, increasing air conditioning and ventilation equipment.

3. The SMT workshop of PCB Factory has poor sealing, poor dust-proof facilities and too much dust, which makes the machine easily dirty and vacuum blocked.

Solution: It is strictly forbidden to use windgun blowing machine, electrical equipment and materials in SMT shop of patch processing factory. Carpet dust removal is added at the door of the shop.

4. Insufficient loading platform and FEEDER truck cause non-standard loading and damage and distortion of FEEDER.

Solution: In SMT workshop of PCBA manufacturer, add loading table and FEEDER car, and work strictly according to WI requirements.