Fabrication And Investigation Of Heat Transfer Performance Of A New-style Miniature Flat Heat Pipe

With the progress of electronic technology, higher calculation frequency, speed and denseness has become the developmental direction of the electronic component, which result in the rapidly increasing of the heat flux in recent years. With the high thermal conductivity, perfect uniformity of temperature distribution and essential characteristics of compact structure, miniature flat heat pipe is considered to be one of the potential technologies that can solve the cooling problem of the electronics industry. In this thesis, A new style flat heat pipe with the characteristic of low price, light, flexibility and insulativity is introduced, which is expected to make the heat pipe used in more regions and provide a new means to solve the problem of heat dissipation. Main contents are as follows.Firstly, based on the basic theory of heat pipe, the new-style miniature flat heat pipe was designed. The capillary pressure balance and the heat transfer limit were analyzed, and the value of the heat transfer limit was calculated.Then in this paper, the material and the structural of the case, the internal working fluid, capillary wick and so on were designed.Secondly, the new-style miniature flat heat pipe was fabricated, and the process included the manufacture of the structure of pipe case and the wick. In the fabrication, photo lithography, electroplating, reactive ion etching, wet chemical etching and sintering technology were used. Then the components were assembled and sealed after cleaning.Finally, the heat transfer characteristics of the new-style miniature flat heat pipe in different working conditions are researched. By calculating the total thermal resistance of flat heat pipe, the author analyzes the influence of the heating power, tilt angle, filling ratio and working fluid on the heat transfer performance of heat pipe. The results show that optimum filling ratio of the heat pipe is 1.1 and the maximum heat transfer capability is 7.2W-10.2W.Then the effective thermal conductivity of the flat heat pipe was calculated. When tilt angle is zero, the maximum effective thermal conductivity of the flat heat pipe with water as working fluid is 736W/m·K.