Industrial Technology Research Institute

Embed Technology Co., Ltd.

Te-Yeu Su

Hsin-Herng Wang

Bin-Yuan Lin

Chia-Tin Chung

Wun-Ku Wang

Hui-min Huang

Li-Chung Ping

Ying-Ti Chu

Su-Jen Chang

Chin-Ming Chu

Wei-Chun Yang

The present invention teaches formulations, apparatus and a method of applying high thixotropic index polymer thick-film resistive pastes for making polymer thick-film resistors with improved tolerances by providing a squeegee with a blade tilted at an angle of 10&#xb0; to 85&#xb0; to the surface of the printed circuit board thus causing a fluid rotational motion within the bead of the polymer thick-film resistive paste as the squeegee blade moves relative to the printed circuit board. This rotational motion increases the shear strain rate experienced by the paste within the bead and results in a more effective filling of the resistor-shaped cavity without including air bubbles, experiencing elastic recovery of the paste and, without surface fractures of the paste.

Method of applying a polymer thick-film resistive paste for making polymer thick-film resistor having improved tolerances

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.

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

Polymer thick film resistor pastes with dimensionally stability and excellent processibility, such as coating, printing, and extruding, are disclosed. The resistor paste composition in accordance with the present invention comprises a low-k cycloaliphatic epoxy resin vehicle loaded with electrically conductive particles, a cationic photoinitiator, a thermal catalyst, and optionally a reactive diluent.

Polymer thick film resistor pastes

Growing community of inventors

Hualien, Taiwan

Te-Yeu Su