Fabrication and test of a filling station for micro/miniature devices

Working fluid filling is one of the most difficult problems normally encountered in micro/miniature heat pipe manufacturing and processing. Three methods for proper heat pipe filling are introduced and evaluated in this paper. These methods are referred to as the screw-piston valve/vacuum bypass, screw-piston valve/sealed reservoir, and micro-syringe/T-junction methods, respectively. The screw-piston/vacuum bypass method proves to be feasible but less accurate. The screw-piston/sealed reservoir fails to yield any meaningful result at the present time. However, the method based on the micro-syringe/T-junction proves to be quite successful, which yields a high filling accuracy and high vacuum condition in the heat pipe.