Common Problems and Solutions for PCB Film

In the PCB manufacturing process, some PCB film failures are generally encountered when using PCB dry film technology, the article introduces common faults and solutions for PCB film.

1. The dry film does not stick firmly on the copper foil.
(1) The surface of the copper foil is not clean, with oil stains or oxide layers. Re-clean the board surface and operate with gloves.
(2) The solvent in the dry film solvent evaporates and deteriorates. Store at low temperature and do not use expired dry film.
(3) Fast transfer speed and low PCB film temperature. Change the PCB filming speed and PCB filming temperature.
(4) The ambient humidity is too low. Keep the relative humidity of the production environment at 50%.

2. Air 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 pressure of the PCB film, and handle the board lightly.
(2) The surface of the hot pressing roller is uneven, with pits and film drilling dirt. Pay attention to protecting the flat surface of the heat press roller.
(3) PCB film temperature is too high, reducing the PCB film temperature.

3. Dry film wrinkles.

(1) The dry film is too sticky, place the board carefully.

(2) The board is too hot before the PCB film, and the board preheating temperature should not be too high.

4. Surplus glue.
(1) The quality of the dry film is poor, replace the dry film.
(2) The exposure time is too long, shorten the exposure time.
(3) The developer is invalid, change the developer.