1. The loss of the sensitive film in the development cannot make the plate. (1) Under exposure. (2) The dosage of photosensitizer is insufficient or invalid, and the sensitivity is reduced.
2. The whole image produces light gray. (1) The working place of coating and drying process of photographic solution is too bright. (2) Insufficient exposure time and development. (3) Part of the photosensitive coating and drying, over heating. (4) Exposure time is too long.
3. The fine parts of the image are not developed. (1) Exposure time is too long. (2) The positive surface is upside down, and the positive surface and the sensitive film are not well closed. (3) Insufficient wire mesh pretreatment. (4) The sensitive film is too thick and the type of sensitive adhesive is not properly selected or the sensitive adhesive fails.
4. There are a lot of bubbles in the coated screen. (1) The degreasing treatment of wire mesh is not sufficient. (2) Clean the screen before coating the photoresist. (3) In the coating process, the temperature difference between the screen drying and the photoresist is large. (4) The storage temperature of photoresist is too high. (5) Light sensitive adhesive and coating layer are too thin. (6) Coating speed is uneven.
5. Too many pinholes in the layout. (1) Dust is the main cause (2) the penetration is caused by the blistering of the photographic solution itself. (3) When using the coating scraper, the coating scraper moves too fast and easily blisters to produce pinholes. (4) Too much photosensitizer will also produce pinholes. (5) The coating surface is easy to fall dust, so it is necessary to keep the workplace clean, such as the glass surface, the soft side of positive image, and the coating surface of photosensitive solution. (6) A small amount of octanol can be added to the photosensitive solution as defoamer.
6. There are obvious pores after the development of screen printing plate. (1) Whether the film has been dried at high temperature. (2) Whether a photosensitizer with a long shelf life is used. (4) Whether there is dust falling into the photoreceptor. (5) Whether the photosensitizer and emulsion are fully stirred when mixing, and whether they are used after the bubble disappears. (6) Master whether the exposure time is appropriate.
7. The resolution of image and text is not high after printing. (1) Whether the development is sufficient, and whether water is used for pressure washing after development. (2) Whether the secondary screen has been cleaned before use. （3） Whether the screen is dry in horizontal position. (4) Whether a sensitive adhesive with high resolution is selected.