Determination of temperature profiles in microcircuits

Circuit reliability and performance, particularly in microcircuits, are affected by temperature; therefore, a knowledge of the heat transfer paths and temperature gradients and hot spots are of prime importance to proper design specifications and to efficient performance of microcircuits. The method of thermal mapping described in this paper involves a direct and rapid infrared scanning technique. The "heart" of the system is a photo sensitive element of single crystal indium antimonide with a long wave length cut-off near six microns. The method has been found to be satisfactory in generating isothermal patterns in tantalum microcircuits from 50°C to >250°C. Hot spots 1.3 mil in diameter are readily detected.