The classical colour of a circuit board is green. The colour is achieved by applying so-called solder resistors which we also offer in white, red, blue and black in addition to green.
Solder resistors serve initially to protect the copper structures from oxidation and from damage to the surface.
The solder-resist coating is carried out by a photo-printing process whereby a special varnish polymerised by UV-light is applied to the circuit board surface (methods used are casting or screen printing) and, finally, exposed photo technically. The non-polymerised component parts exposed remain water soluble and, even in micro-meter zones, are developed with sharply defined contours. A final thermal curing follows to achieve the required electro-physical characteristics of the varnish.
MicroCirtec uses solder resistors based exclusively on epoxy resin as this further improves creep-resistance on the surface of the circuit board.