To limit heat transfer to unnecessary parts by making a thermal conductivity to be equivalent to or higher than that of copper, etc., by orienting a carbon fiber in an aluminum alloy in a uniaxial direction, combining a sum of the carbon fiber and a binder for fixing it at a specific volume percentage, and setting a quantity of binder to a specific volume percentage.
A highly thermal conductive carbon fiber is bound and shaped by an aluminum alloy, and the carbon fiber oriented in a uniaxial direction and a binder for fixing the carbon fiber are combined at 40-90 vol.% in total. In the case of not more than 40%, a sufficient thermal conductivity cannot be obtained, and in the case of 90% or more, the carbon fiber cannot be bound and shaped sufficiently by the aluminum alloy. When taking into consideration its thermal characteristic, it is preferable to set to 60-85%. Further, the quantity of binder therein is set to 5-25 vol.%. Since the carbon fiber is oriented in a uniaxial direction, its shape can be controlled easily, and it is applicable for high-dense mounting device, etc., because of high anisotropy of thermal conductivity.
NINOMIYA JUNJI
HIDENO AKIRA
