| 摘要 |
PURPOSE:To obtain a support which is so prescribed in thermal conductivity, resistivity, bending strength, and fracture toughness to be higher than certain values in physical properties and formed taking advantage of a SiC matrix, by a method wherein material is so compounded as to enable Si to be left unreacted in a Si/C reactive sintering process, and the unreacted Si is treated in an atmosphere of nitrogen to grow whiskers of Si3N4. CONSTITUTION:Metal Si powder 0.5mum or below in grain diameter and C powder 0.7mum or below in grain diameter are made in the weight ratio 1:0.3 and mixed together, and 5% by weight of W powder 1.0mum or below in grain diameter is added to the mixed powder of Si and C and mixed together. Then, the mixture is heated in an atmosphere of Ar up to a temperature of 1600 deg.C at a tempertaure rate of 5 deg.C/min to obtain a SiC sintered body. The SiC sintered body is cooled down to a temperature of 1100 deg.C, Ar gas is replaced with N2, and then the sintered body is kept at a temperature of 1390 deg.C for one hour to enable unreacted Si to react with N2, whereby whiskers of Si3N4 are generated in the voids of the sintered body. By this setup, a semiconductor chip support larger than 140W/m deg.C in thermal conductivity, 10<8>OMEGA.m in resistivity, 500MPa in bending strength, and 7MPa.m<1/2> in fracture toughness can be obtained. |
