Evaluation of materials for high temperature IC packaging

Fast decrease of device dimensions, rapid growth of the number of elements per integrated circuit device (IC) and the increasing amount of interconnections between the chip and the substrate lead to a more complex design and production of the ICs and to higher demands towards packaging technology as well. This is especially true in the field of high temperature electronics with operating temperatures of up to 250degC. We present an evaluation of materials for both the adhesive and the encapsulant for packaging of high temperature ICs for this temperature range. Among the available materials only glass-based formulations could withstand extended periods of heat and substantial numbers of temperature cycles. In addition, samples of high temperature CMOS ICs (capacitive pressure sensors and EEPROMs) have been successfully assembled using these materials.