PCB Tech - Causes of PCBA throwing materials and solutions

PCBA circuit board processing is an indispensable step in the design and production process of electronic equipment. PCBA circuit board carries the control system of electronic equipment. Its quality directly affects the operation of electronic equipment and product quality. A good product cannot do without High-quality PCBA circuit board support, and in the process of PCBA circuit board processing, some problems will inevitably be encountered. Today, let’s learn about one of the PCBA solutions: the cause of throwing and the solution to PCBA

Reason 1: The nozzle problem, such as the nozzle deformation, blockage, or damage caused by insufficient air pressure, air leakage, resulting in unacceptable suction, incorrect retrieving, identification failure and PCBA throwing.

Countermeasures:  clean and replace the suction nozzle;

Reason 2: The feeder problem, the feeder is set up incorrectly, the position is deformed, and the feeding mechanism is not good.

Countermeasures: reset the feeder, clean the equipment, calibrate or replace the feeder.

Reason 3: Recognition system problems, poor vision, unclean vision or laser lens, foreign objects interfering with recognition, improper selection of recognition light source or insufficient intensity or grayscale, or the recognition system is broken.

Countermeasures:  Clean and wipe the surface of the recognition system, keep it clean and free of foreign matter, oil pollution, etc., adjust the intensity and gray level of the light source, and replace the components of the recognition system;

Reason 4: Position problem, position deviation, the suction nozzle is not in the center of the material when picking up the material, the picking height is incorrect (usually the part is pressed down by 0.05mm after touching the part), which causes the deviation, the picking is not correct, there is Offset, the identification system does not match the corresponding data parameters and is discarded as invalid materials by the identification system.

Countermeasures:  Adjust the reclaiming position, height and other parameters;

Reason 5: Vacuum problem, insufficient air pressure, unsmooth vacuum pipe passage, foreign objects blocking the vacuum pipe, or vacuum leakage caused insufficient air pressure and the material cannot be retrieved, or it falls on the way after picking it up.

Countermeasures:  Adjust the air pressure steep slope to the required air pressure value of the equipment (generally 0.5~~0.6Mpa required by the placement machine), clean and dredge the air pressure pipeline, and repair the leaking air circuit;

Reason 6: There is a problem with the placement machine program. The component parameter settings in the edited program are incorrect, and the actual size, brightness and other parameters of the incoming material do not match, which causes the recognition to fail and is discarded.

Countermeasures: modify the component parameters, search for the best parameter value of the component;

Reason 7: incoming material problems, incoming materials are not standardized, or unqualified products such as oxidation of incoming pins.

Countermeasures:  IQC does a good job of inspecting incoming materials and contacting component suppliers;

Reason 8: Feeder problem, feeder deformation, feeder poor feeding (feeder ratchet gear is damaged, the material belt hole is not stuck on the ratchet gear of the feeder, there is foreign matter under the feeder, and the spring is aging, Insufficient power, or poor electrical), resulting in insufficient or poor reclaiming, PCBA throwing, and damage to the feeder.

Countermeasures: correct the feeder, clean the feeder platform, replace damaged parts or feeders;

According to relevant studies, static electricity is also a cause of PCBA throwing, so the placement machine must be grounded and the production site must be anti-static.

It is normal for the placement machine to have PCBA throwing away, but if the PCBA throwing rate is high, it will seriously affect the production efficiency and production cost, and it must be solved. When there is a serious PCBA throwing phenomenon, you can first ask the on-site personnel, through the description, and then based on the above seven reasons, observe and analyze directly to find the problem, so as to find out the cause more effectively, solve it, and improve production efficiency., But it takes up too much machine production time.