Abstract

The widespread use of GaAs MMICs in microwave systems require assembly technologies with high yields and high reliability, while preserving the intrinsic performance of the die. This is a difficult task, given the large lateral dimensions and reduced thickness of MMICs, complicated by the presence of via-holes. This paper will present some of the results obtained during assessment of various techniques used for die-attach. These results show that the major reliability concern is the behaviour of the die attach medium within the via-holes. We will present a new process designed to control this behaviour.