MOUNTING OF SEMICONDUCTOR DEVICES

摘要

A semi-conductor chip (12) mounted on a substrate (13) is located in a well (14) surrounded by a layer (15) of glass ceramic material of approximately the same thickness as the chip. The connection between pads (17) on the chip 12 and on copper metallisation on the surface of the glass ceramic is made by wires (18). The substrate (13) is made of copper or other metal of similar high thermal conductivity and comprises a two dimensional array of closely spaced narrow pillars extending from a flat base. This construction enables heat to be conducted away rapidly by means of the pillars but as a result of the enormous reduction in the mechanical stiffness of the metal substrate in the plane of the surface avoids the undesirable stress and strains which would otherwise result from temperature changes.