US 6,280,907 B1 · Process for forming polymer thick film resistors and metal thin film resistors on a printed circuit substrate

Abstract

A process is disclosed for forming resistors on a printed circuit substrate. The method includes the step of applying a photoresist layer onto substrate, and forming openings in the photoresist layer to expose the preselected regions for resistors, such that polymer thick resist pastes as well as resistive metallic films can be applied onto the substrate through these openings with precise geometry. The process according to the invention has higher accuracy and greater processing flexibility than the prior art processes where the resistor pastes are directly applied onto the substrate by screen printing.

Claims10

Dependent claims

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.

4 more elements

Dependencies are inferred from the claim text.

Process for forming polymer thick film resistors and metal thin film resistors on a printed circuit substrate

Life of this patent

Process for forming polymer thick film resistors and metal thin film resistors on a printed circuit substrate

Life of this patent

Abstract

Claims10