The main reason for short circuit of PCB is that the film line is scratched or there is garbage on the coated screen, and the coated anti-plating layer is fixed with exposed copper, resulting in a short circuit.
Improve Methods:
- The film negative should not have problems such as trachoma, scratches, etc. When placing the film, the surface of the film should be facing up, and it should not be rubbed with other objects. When copying the film, the film should be operated on the surface of the film, and the appropriate film should be loaded in time after use. Store in a film bag.
- When aligning the film, the film should face the board surface. When taking the film, use both hands to pick it up diagonally. Do not touch other objects to avoid scratches on the film surface. Check or replace, and store in a suitable film bag after use.
- Operators should not wear any decorations such as rings, bracelets, etc. on their hands. Nails should be trimmed and kept smooth. No sundries should be placed on the surface of the alignment table, and the table should be kept clean and smooth.
- Strictly check the screen before production to ensure that the screen is free of problems. When applying wet film, it is often necessary to conduct random inspections to check whether there is garbage blocking the screen. When there is no printing for a period of time, the screen should be empty and printed several times before printing, so that the diluent in the ink can fully dissolve the solidified ink and ensure the smooth oil leakage of the screen.
