COMPOSITE MATERIAL HAVING HIGH THERMAL CONDUCTIVITY/LOW COEFFICIENT OF THERMAL EXPANSION

摘要

PROBLEM TO BE SOLVED: To provide a heat conductive composite material for a heat sink having a high thermal conductivity/a low coefficient of thermal expansion, and an electronic device including a heat sink formed of the same.SOLUTION: A heat conductive composite material 30 is composed of a first metal substrate 12 and a second metal substrate 14, with each having a low coefficient of thermal expansion, and a high temperature pyrolytic graphite layer 32 disposed between the two substrates. The high-temperature pyrolytic graphite layer 32 has a plurality of layered surfaces 34. By orienting the layered surface 34 in a direction perpendicular to the surfaces of the metal substrates 12, 14, the thermal conductive composite material has an in-plane thermal expansion coefficient of about 13 ppm/°C or less and a thickness direction thermal conductivity of about 200 W/m-K or more.SELECTED DRAWING: Figure 5