Packaged For The Road

Abstract

This article discusses use of metal matrix composite materials in electronic packaging. Composites can have higher thermal conductivity than traditional materials, low thermal stress, and tailorable coefficients of thermal expansion. They can reduce weight by as much as 80% and size by as much as 65%. They can also be used in low-cost, net-shape fabrication processes. The silicon carbide content can be adjusted to differing percentages to vary the composite's coefficient of thermal expansion. Traditional microelectronic packaging materials used to achieve low coefficients of thermal expansion include blends of copper and tungsten or of copper and molybdenum, and a nickel–cobalt–iron alloy called Kovar, a trademark owned by CRS Holdings Inc., a subsidiary of Carpenter Technology Corp. of Wyomissing, Pennsylvania. A key firm involved in promoting pyrolytic graphite in packaging is Advanced Ceramics Corp. of Cleveland. An expert predicts that, in the future, many of these materials will also be used in the optoelectronics industry. This will be a new market for the materials, but one with enormous potential.