Summary of common problems and solutions for PCB paste dry film
(1) Air bubbles appear between the dry film and the surface of the copper foil
Problem: Choosing flat copper foil is the key to ensuring no bubbles.
Solution: Increase the pressure of the PCB film, and handle the CCL lightly.
Problem: The surface of the heat press roller is not flat, there are pits and the film is dirty.
Solution: Regularly check and protect the flatness of the surface of the heat press roller.
Problem: The temperature of the PCB film is too high, causing some contact materials to produce wrinkles due to temperature differences.
Solution: Reduce the temperature of the PCB film.
(2) The dry film is not firmly attached to the copper foil
Problem: The surface of the copper foil is not properly cleaned, and the direct operation will leave oil stains or oxide layers.
Solution: Wear gloves to conduct PCB cleaning.
Problem: The quality of the dry film solvent is not up to standard or has expired.
Solution: The PCB manufacturer should choose high-quality dry film and check the shelf life of the dry film regularly.
Problem: transfer speed is fast, while the PCB film temperature is low.
Solution: Change the PCB filming speed and PCB filming temperature.
Problem: The humidity in the processing environment is too high, which leads to a prolonged dry film bonding time.
Solution: Keep the relative humidity of the production environment at 50%.
(3) Dry film wrinkles
Problem: The dry film is too sticky, so be careful when placing the board during the operation.
Solution: Once contact occurs, it should be dealt with in time.
Problem: The board is overheated before the PCB filming.
Solution: The preheating temperature of the board should not be too high.
(4) Glue remains
Problem: The quality of the dry film is poor.
Solution: Replace the dry film.
Problem: The exposure time is too long.
Solution: Have an understanding of the materials used and carry out a reasonable exposure time.
Problem: the developer is ineffective.
Solution: Change the developer.