| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a low thermal expansion coefficient composite material having high thermal conductivity and a small thermal expansion coefficient to the same level as those of silicon or compound semiconductors, and having substantially no thermal expansion hysteresis. <P>SOLUTION: The composite material having the high thermal conductivity and the small thermal expansion coefficient is obtained by impregnating a porous graphitized extrudate with a metal; the metal is an aluminum alloy composed of 11 to 14 mass% silicon and the balance aluminum and inevitable impurities. The major diameter of the silicon (Si) rich phase precipitated in the metal structure is≤30μm and the ratio (area ratio in a microscopic photograph) of the acicular structure of≤30μm in major diameter and≥10 in an aspect ratio (major diameter x minor diameter); the composite material having such anisotropy that the thermal conductivity and the thermal expansion coefficient are 250 W/mK or more and less than 4 x 10<SP>-6</SP>/K, respectively, in an extrusion direction; and that the thermal conductivity and the thermal expansion coefficient are 150 W/mK or more and 10 x 10<SP>-6</SP>/K or less, respectively, in a direction perpendicular to the extrusion direction. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
