ABSTRACT
The amount and density of electronic components in VLSI chips sharply increases on modern integrated circuits. The heat generated in these chip results in high-operating temperature if not removed, which will degrade the speed and the stability of the electronic devices(Suma&De 2005). Furthermore, the thermal stresses inherent within a chip during operation typically result in failure caused fatigue of the mechanical devices or connections (Pandraud,& Martine 2006). Cotter first introduced the concept of micro heat pipe for the dissipation and removal of heat. Then micro heat pipe is used in many fields because it has the merit of high efficiency, no noise, and without power(Jiao, and Ma 2007, Suman&Hoda. 2005). Recently many micro heat pipes use fibers as wick structure to increase the characteristic, and fiber wick becomes one of the significant researches (Peterson and Ma 1996, Suh, Greif and Grigoropoulos.2001))
Precious mathematical models are mostly designed for micro grooved heat pipe, so developing a new mathematical model to predict the characteristic of the micro heat pipe with fiber wick is necessary (Suh, Greif, and Grigoropoulos. 2001). A three-dimensional mathematical model is developed by finite element method in this paper. The effects of phase changing, the contact angle, gravity, and heat conducting between the fibers are accounted in the model. The governing equations are formulated by conservation of mass, momentum and energy in three dimensions. The model is calculated by iteration and the results can be used to predict the thermal
resistance of the micro heat pipe under different input powers. The theoretical results are analyzed and compared with experimental testing data.
