Compliant microelectronic mounting device

Abstract

The present invention provides an interconnection scheme having complaint contacts arranged in an array to connect conductive surfaces on a microelectronic device and a supporting substrate, such as a printed circuit board. This invention accommodates for the difference in thermal coefficients of expansion between the device and the supporting substrate. Typically, an area array of conductive contact pads are connected into rows by conductive leads on a flexible, intermediate substrate. Each of the conductive leads bridges a bonding hole in the intermediate substrate which is situated between successive contact pads. Each of the conductive leads further has a frangible portion within or near each bonding hole. A stand-off between the intermediate substrate and the device is create by compliant dielectric pads, typically composed of an elastomer material, positioned under each contact pad. The frangible portions allow the leads to be cleanly broken, bent and secured into electrical contact with chip contacts on the device. Each of these connections may be supported by a compliant layer, typically an uncured elastomer which fills the area around the compliant dielectric pads and is then cured.