Vacuum fluid charging and packaging technique for micro heat pipes

One of the most critical issues in electronic industry is the thermal management of electronic devices, such as high-power light-emitting diodes (LEDs), high density integrated circuit(IC). Currently, the major limitation for the development of such devices is due to the lack of an efficient technique to remove heat in a narrow space. Micro heat pipes (MHPs) using MEMS technique can solve this problem theoretically. However, the charge of working fluid in such a small volume is still unsolved. Unfortunately, the performance of MHPs largely depends on the accuracy of filling ratio. Double air pumping charge method is proposed in this paper. The first air pumping process made the working fluid flow into the chamber of MHPs, the second pumping ensure the final filling ratio and the vacuum degree. This method can reach high accuracy filling and high vacuum for MHP. Meanwhile, the charge and package system is simple and has the potential to mass production.