Two-dimensional heat flow in a GTO having a highly interdigitated emitter

Thermal analogs of thyristors having the form of transmission lines are used routinely for calculating thermal phenomena, but they cannot be used for a gate-turnoff (GTO) structure without the appropriate modifications. The authors show the generation of a thermal analog for a 77-mm GTO in which the interdigitated emitter contains 2000 individual islands, whereas the adjoining strain buffer is a full-area metal plate. The heat transfer from the island to the substrate, the angle of the heat flow, and the thermal resistance values of the interdigitated silicon and the substrate are calculated. The lateral heat flow between adjacent islands, a transient phenomenon that occurs before thermal equilibrium is reached, is also represented in the analog.<>