A New High-Reliable Thick Film System for Automotive Use

This paper describes the development processes of a highly reliable thick film system for automotive use. There are mainly two thick film systems for automotive use: The Ag system using Ag as the conductor and the Cu system using Cu as the conductor. The resistor of the Ag system is inexpensive, however, the conductor is less leliable. On the contrary, the conductor of the Cu system has superior characteristics, however, the resistor is ecpensive. In ader to solve these contradictory problems of both systems, a composite system consisting of a esistor of the Ag system and the Cu conductor was ecently developed. However, the system still has two reliability problems concerning car electronics components which require high reliability, namely the reliability of the soldering joint strength of the conductor and the high voltage characteristics of the resistor. We explored the mechanism of these problems and solved them to successfully develop the new reliable thick film system for automotive use.