Common faults and solutions for film in PCB copy board

In the PCB process, some film failures commonly encountered in PCB dry film technology are used. The article describes the common faults and solutions of the film.

1. Dry film is not stuck on copper foil

 (1) The surface of the copper foil is not clean and has an oil or oxide layer. Re-clean the board surface and wear gloves.

 (2) The solvent in the dry film solvent volatilizes and deteriorates. Store at low temperatures and do not use expired dry film.

 (3) The transfer speed is fast and the film temperature is low. Change film speed and film temperature.

 (4) The ambient humidity is too low. Maintain a relative humidity of 50% in the production environment.

2. Bubbles appear between the dry film and the surface of the copper foil

 (1) The surface of the copper foil is uneven, with pits and scratches. Increase the film pressure, and gently transfer the plate.

 (2) The surface of the hot press roller is not flat, and there are pits and film to smear. Take care to protect the surface of the hot press roller.

 (3) The film temperature is too high, and the film temperature is lowered.

3. Dry film wrinkling

 (1) The dry film is too sticky, and the plate is carefully placed.

 (2) The front plate of the film is too hot, and the preheating temperature of the board should not be too high.

4. Plastic

 (1) The dry film quality is poor, and the dry film is replaced.

 (2) The exposure time is too long to shorten the exposure time.

 (3) The developer fails and the developer is changed.