A High Complexity Tape Automated Bonding Application For Apace Hardware

Abstract

A highly complex Z-Technology module, intended for use in a surveillance satellite, has been greatly simplified by using Tape Automated Bonding (TAB) processes. The module design is based on multiple layers of thin-film substrates as interconnections between active devices mounted on three surfaces and as packaging protection for the custom LSIC devices involved. Most of the TAB processes make an excellent fit with processes already on-line in a thin-film fabrication and assembly operation. A need to attach the TAB leads to ceramic substrates at various levels above the level of the substrate to which the dice are attached complicated the application, and the solution to this problem is detailed. The process development steps needed to apply TAB technology to the product are described, along with evaluation tests which were performed to assure that the thin and fragile ceramics are not broken during pressures encountered in the processing. Automation of the TAB processes and the production steps are also discussed. A cost trade-off study shows the extent to which automation is cost effective. Product design, production equipment design, and process and test changes needed to apply TAB technology to the product are presented, and anticipated payoff in terms of cost reduction and reliability improvement are given. In spite of difficult requirements imposed by space-rated specifications, the TAB processes have been adapted to provide cost and risk reductions as well as reliability improvements while enabling MIL specifications to be met.