Air-cooling system for metal oxide semiconductor controlled thyristors employing miniature heat pipes

Abstract

Different cooling methods for metal oxide simeiconductor controlled thyristors (MCTs) are discussed, and an air-cooling system employing miniature heat pipes as thermal spreaders is proposed. Theoretical analyses show that the proposed air-cooling system outperforms many single-phase liquid-cooling systems. A cooling scheme involving installation of miniature heat pipes in the mounting surface of MCTs for single-phase liquid cooling is also described. For the fabrication of miniature heat pipes, an electricdischarge-machining (EDM) wire-cutting method is introduced, which can be used to directly fabricate miniature heat pipes into the heat sink as an integral part of the cooling system. A miniature heat pipe sample is fabricated employing the proposed EDM wire-cutting method and is tested under different working conditions. Experimental results show that the miniature heat pipe works well, with an effective thermal conductance more than 100 tunes that of copper. The EDM wire-cutting method developed in this article provides a new heat pipe fabrication method that can be used not only for MCT cooling, but for many other applications as well.