Design of Temperature-Controlled Substrates for Hybrid Microcircuits

This paper deals in depth with the criteria that govern the design of temperature-controlled substrates for hybrid microcircuits. Pertinent thermal parameters for the more important microcircuit-fabrication materials are presented in tabular form, along with several useful unit-conversion factors. Substrate heat losses due to conduction, convection, and radiation are then analyzed, and equations are developed for determining optimum substrate temperature, steady-state input power, and warm-up characteristics. Control-circuit design is discussed, and consideration is given to power dissipation by circuitry off as well as on the substrate. The effects of changes in ambient temperature on temperature-controlled-microcircuit performance are analyzed. Two applications of this technology are described.