Both dry film and wet films are used as raw materials for wiring. The dry film is a high molecular compound which, after being irradiated by ultraviolet rays, can be produced by a polymerization reaction to form a stable substance attached to the surface of the board, thereby achieving the function of blocking plating and etching. A wet film is a kind of photosensitive ink, which is an ink that is sensitive to the purple line and can be cured by ultraviolet rays.
PCB dry film and wet film mainly have the following differences:
1. The functions of the dry film and the wet film are basically similar, but if the surface of the substrate is not flat and does not need to be too thick or too thick, the wet film can be considered. Dry film is more suitable for perforated circuit boards, or when the working environment is not easy to keep clean, it is also recommended to use a dry film that is easy to control.
2. Dry film is easy to operate, the unit price is slightly higher than the wet film. However, the dry film is easy to keep clean and does not have to be baked, so it is convenient to use. However, if a thin film thickness is required, especially a thickness of 15μm or less, dry film is not recommended.
3. The wet film has a good filling ability, but the curing requires a higher ultraviolet exposure energy.
In summary, although the wet film material is relatively inexpensive, it cannot be used anywhere. When choosing wet film or dry film, it is still necessary to take the manufacturer's own operating environment requirements into account.
Dry film thickness gauge can be used to test the thickness of the dry film. The dry film thickness gauge LS220 can switch between iron-based, nonferrous-based freely. It is very convenient to use. If need to measure the thickness of the wet film, it’s recommended to use a non-contact thickness gauge, also called ultrasonic thickness gauge.