INFRARED PHOTOELASTIC RESEARCH OF SINTERI NG STRESS IN SILICON THYRISTOR

By referring to the theories of thermoelasticity and thermal interlami nar stress of composite, the stress in silicon wafer and the interlami nar stress of structure Si/Al/Mo used for making thyristor after sinte ring were analyzed. It was found that the distribution of stress cause d by different properties of thermal expansion in the center portion i s different from that at the edge of silicon wafer. The expression for stress at the edge of silicon wafer was derived. The stress photoelas tic patterns were obtained by means of the infrared photoelastic syste m. The theory coincides well with the results of experiment.