SIMULATION OF LASER TRIMMING OF FILM RESISTORS

Abstract

Laser trimming is an indispensable step of manufacturing of high precIsion thick film resistors. In order to assure long term stability and reliability of laser trimmed film resistors, designers must prepare special trimming path regarding the real effects of laser cutting, The computer program created by the author, presented in this paper, is useful for analyzing influence oftrimming an arbitrary film resistor with inhomogeneous conductivity by an arbitrary laser trim strategy, taking into consideration the effects of heat-affected zone (HAZ). Some real examples are presented to demonstrate the suggested use of this method, which helped the author to find such a complex cut line, which provides low current density, low noise, long term stability and reliability.