A METHOD FOR TRIMMING PRINTED RESISTOR

Publishing Venue

Motorola

Related People

Abstract

Resistor elements deposited in substrates such as printed wiring board laminate can be trimmed by inexpensive means. The cost of laser or air-entrained abrasive trimming can be avoided.

Mm-LA Tachnlcal Development8 Volume 2 January 1982

A METHOD FOR TRIMMING PRINTED RESISTOR By Ted Lester

Resistor elements deposited in substrates such as printed wiring board laminate can be trimmed by inexpensive means. The cost of laser or air-entrained abrasive trimming can be avoided.

   The use of polymer thick films as resistance elements on organic substrates permits substituting discrete resistor with resistive paths printed directly on a printed wiring board. Trimming can be ac- complished by maklng a saw cut through both the printed resistor and its supporting substrate. To ac- complish this, the trimmable resistors are placed at the board edge where they can be accessed by a saw. A slot is cut from the board edge into the resistor detail to the depth required to trim the resistor to its desired value.

TR I MMABLE RESISTOR

R TERMINATIONS

PRINTED WIRING BOARD BOARD EDGE

0 Motorola. inc. 1982 20