Aluminium@ carbon@ fibre composite material - for electronic component mounting, has high strength and low density

摘要

A material for mounting an electronic component consists of an Al(alloy) matrix contg. 15-55 vol.% carbon fibres distributed in layers in a fixed direction and oriented randomly in directions perpendicular to the fixed direction. The carbon fibres pref. have a shape factor of 10-500, a diameter of 5-15 microns and an elasticity modulus of 3.5-9 GPa. The fibres may be PAN based fibres or tar based fibres. The matrix may be of pure Al or an Al-Cu, Al-Mn, Al-Si, Al-Mg, Al-Mg-Si or Al-Zn-Mg alloy. The material has a density of 2.4-2.6 g/cu.cm., and may contain silicon carbide or nitride whiskers or whiskers of alumina, graphite, potassium titanate, aluminium borate and/or zinc oxide. ADVANTAGE - The material has enhanced physical properties resulting in improved performance and reliability of electronic component assemblies, has a low density and a thermal expansion coefficient near that of Al (alloy), and is easily mfd. without faults such as detachment.