抄録
Thermal cycle fatigue tests are carried out using Cu/Si_3N_4 ceramic substrates under four types of thermal cycle conditions including high temperature region and subsequently the residual strength of the ceramic substrates subjected to the thermal cycle is measured by four-point bending tests in order to investigate effects of thermal cycle conditions on thermal cycle fatigue strength properties of Cu/Si_3N_4 ceramic substrates. About 20 percent reduction in the residual strength of the ceramic substrates is seen in thermal cycle conditions of 0 to 125℃, -40 to 125℃ and -40 to 250℃ for 1000 cycles. Whereas in the case of -40 to 400℃ for 1000 cycles including high temperature region, the residual strength drastically decreases compared with those in other thermal cycle conditions, and the more than 80 percent reduction in the residual strength is observed.
