Electronic Equipment Thermal Management

The purpose of this paper is to describe the importance of thermal management in electronic equip ment design and illustrate how Computer Aided Design (CAD) technology may be used to improve thermal management programs for electronic equipment. The Aeronautical Systems Division is establishing a program called the Electronic Equipment Thermal Management (EETM) Program which is a portion of the recently introduced aircraft system level Thermal Management Control (TMC) Program. The system level TMC program establishes the process by which we thermally integrate the airframe Environmental Control System (ECS) and the electronic equipment in such a manner as to optimize system reliability by minimizing system Life Cycle Cost (LCC). Minimizing LCC is accomplished by allocating available cooling capacity to individual equipments based on the benefits that will be derived. TMC was introduced to take advantage of existing technologies being applied through the latest CAD techniques and the known relationship between electronic part operating temperatures and the resulting part reliabilities. When this relationship is fully utilized, the thermal design and packaging of the equipment can be optimized for improved equipment reliability at lower operating temperatures. In addition, reliability improvement techniques such as selective derating, part selection, etc., can be concentrated on those parts that have been identified by the thermal analysis to be drivers in equipment unreliability. Concentration of effort is placed at the part level. After all, "systems do not fail, parts do!"