Non-transparent printed circuit base - coated with organic absorption agent in acrylic resin

摘要

The base is coated with an org. absorption agent, pref. dispersed in acrylic resin, which absorbs the radiation used to photoetch the circuit pattern in the photosensitive layer. The latter is applied over the absorption agent layer and then photoetched via a mask to form the required circuit pattern. Non-irradiated parts of the photosensitive layer and acrylic resin and absorption agent in exposed areas are removed with the same solvent, e.g. 1,1,1-trichloroethane, before metal deposition to form the circuit. Both sides of the base can be printed without the irradiation of one side affecting the pattern on the other side.