Computer modeling of heat transfer of a MEMS based on micro-jet array air impinging cooling device

The cooling of localized, non-uniformly distributed hot spots on circuit boards remains a significant electronic packaging problem. If the heat removal requirements of these locations were utilized for setting global cooling characteristics, the cooling systems would be over-designed, leading to unacceptable cost, size, noise and vibration. This is especially true in air-cooled applications such as small computers, communication switching and transmission equipment. Therefore, the preferable design alternative is to provide the required high cooling rates only where they are needed.; Efficient use of air for heat removal in small electronic devices using forced convection requires investigations of miniature air impingement devices. Leland et al. (1999) built a micro jet array (MJA) impingement-cooling device for high power electronics that combines microscopic scale and impingement. The MJA was constructed from silicon wafers using a micro-electromechanical systems (MEMS) technique. Using the same fabrication processes and materials that are used to make microelectronic devices, micro-electromechanical systems (MEMS) technology conveys the advantages of miniaturization and integrated electromechanical systems.; To be able to utilize this micro jet cooler to its fullest capacity and in multiple applications, one has to fully understand the heat transfer process inside the very small and complex geometry of a micro jet array. However, in reality it is not yet possible to monitor and understand the temperature flux inside a MJA in experimental work. To find the optimum jet geometry, the designer is faced with the problem of changing many parameters. Therefore, a new approach is necessary to investigate the MJA. A numerical design approach is more efficient and economical than an experimental one. In this study computational fluid dynamics (CFD) is applied to understand the heat transfer phenomenon in a MJA designed Leland et al. (1999) and Kuldeep (2003). CFD is used to improve the heat transfer performance and find the optimum jet configuration. Computer modeling is performed using the incompressible and compressible Navier-Stokes (NS) equations. The Navier-Stokes equations are solved by a finite difference procedure in a rectangular grid system. The computed results are in reasonable agreement with the experimental results. The optimum model improves heat removal capacity by approximately 100% relative to the standard case.