Development and Evaluation of Down Trimming of Thick Film Printed Resistors for Space Applications

摘要

This paper presents a novel process of down trimming of thick film printed resistors used in Hybrid Micro Circuit (HMC)s for various subsystems of spacecrafts. The process is standardized and the theory of segregation/redistribution of composite material is presented in this paper. Down-trimmed resistors are tested and characterized for their stability, TCR, VCR, current crowding, noise etc. and are found to perform very well. The process enables flexibility in the HMC layout design and minimizes production wastage and the problem of non-uniform current crowding experienced in up-trimmed resistors. The process uses Birox~R resistor past and 1.064 μm laser. The development could be a major breakthrough in the field.