Development of millimeter-wave transceiver MCM for reliability and productivity, using aluminum-nitride co-fired substrate

NEC has developed the millimeter-wave transceiver MCM (Multi Chip Module) based on the AIN (Aluminum-Nitride) multi-layer HTCC (High Temperature Go-Fired Ceramics) technology, The module is achieving both reliability and mass productivity with excellent millimeter-wave performances. In the size of 3.5cm x 3.5cm miniaturized multi layer co-fired ceramic substrate, the whole circuit functions (the oscillators, the frequency converters and the front-end amplifiers) of the 28/31GHz transceiver are realized. The estimated filed-life is more than ten years obtained by accelerated reliability test. AIN's thermal conductivity of 170W/mK make it possible for power consumption of 10W to be realized in 12cm(2) area single substrate package, keeping the channel temperature of millimeter-wave FET low enough for the reliability. There are several packaging technologies proposed to extend the field life, the de-stressing between the different CTE (Coefficient of Temperature Expansion) materials and hermetic sealing of the microscopic active devices.