Patent ID: 6280907
Filing Date: 2001-08-28
Classification: H01C,H05K

Abstract:
A process for forming polymer thick film resistors on a printed circuit board, comprising the steps of:(a) forming on a substrate a circuit pattern including electrodes which are reserved for resistors;(b) forming a photoresist layer covering said substrate and said circuit pattern;(c) forming one or more openings in said photoresist layer to expose preselected regions for resistors;(d) filling said openings with polymer thick film resistor pastes having one or more resistivities by screen printing or dispensing, and removing the excess resistor pastes by use of a doctor blade, wherein said resistor pastes are of solventless formulation;(e) curing said resistor pastes by either heating or irradiating with ultraviolet rays, or a combination thereof; and(f) removing the remaining photoresist layer to leave one or more polymer thick film resistors on the substrate.