Practical Evaluation of a Cu Thick Film Multilayer System and Wire Bonding on Cu Conductors Available to Purchase

In this study a multilayer hybrid circuit for high frequency digital systems using Cu conductors was fabricated. The available Cu pastes were evaluated in terms of their applicability and a complex multilayer interconnection circuit was realised and optimised using both the DuPont and Heraeus Cu thick film systems. Also, AI‐1% Si wedge bonding on Cu thick film was investigated. The pull strengths were measured before and after ageing (high temperature storage). Results indicate that Al wire bonding on Cu is technologically feasible and gives no reliability problems.