Electrostatic Coating of Photoresists

Electrostatic spray coating with liquid photoresists is described. The process takes place in a horizontal coating station especially developed for the printed circuit board. Thin layers as etching as well as thicker layers as solder mask can be applied onto rigid or flexible base materials and metallised glasses or ceramics. The holes are not coated during electrostatic spray coating. In contrast to a curtain or roller coater no reserve pumping or filtration of the primer is necessary. By using a paper conveyor belt the time taken for cleaning is very low when stopping the machine or changing the primer.