High Efficiency Low Profile Heat Sink for Air Cooling of Microelectronics

Abstract

Cooling of electronics has received considerable attention recently. Simplicity and easy maintenance make direct air cooling a most attractive approach in cooling of electronics. Various heat sinks are often mounted to the microelectronic components in order to enhance thermal performance so that the components can be maintained below the respective temperature limits. The high thermal efficiency low profile cell-fins heat sink is developed to meet the need of high power electronics in the limited space between printed circuit boards often occurred in any microelectronic equipment. For the purpose of comparison, convectional heat sinks, including extrusion fins and plain fins are included in the evaluation. A CFD analysis is performed to characterize the performance of the individual heat sinks. A copper heat sink is mounted to a component on the printed circuit board (PCB) which is cooled by the air with the velocities at 1.5, 2.5, 3.5, and 5.5 m/sec, respectively. In order to simulate the real board condition, the flow by-pass which is an important phenomenon to the performance of the heat sink is included in the analysis. The purpose of this study is to evaluate the thermal performance of the individual heat sinks, with special interests in this newly developed cell fin heat sink at various flow velocities. In addition, the effects of the flow by-pass as well as heat sink flow leakage on the heat sink performance will also be examined in details.