Thermal performance evaluation of different passive devices for electronics cooling

Abstract

The advent of modern electronic technology lead to miniaturization and high power density of electronic devices, then the existing electronic cooling tech-niques cannot be used, directly affecting the performance, cost, and reliability of electronic devices. Thus, the thermal management of electronic packaging has become a key technique in many products. Passive heat transfer devices can be a good alternative to the stabilization of electronic devices temperature. In this re-search, an experimental evaluation of the thermal performance of four different passive devices was accomplished. The considered devices were a rod, a ther-mosyphon, a heat pipe with a metal screen as the capillary structure, and a heat pipe with microgrooves. The heat pipe is a highly efficient device that carries large amounts of power with a small temperature difference. The heat pipe con-sists of the involucre, the working fluid, and the capillary structure. The ther-mosyphon is a kind of heat pipe assisted by gravity. In other words, it has no wick structure to return the working fluid. The devices were made of copper with a to-tal length of 200 mm and an outer diameter of 9.45 mm. The thermosyphon and the heat pipes used deionized water as working fluid with a filling ratio of 60% of the evaporator volume. The devices were tested in vertical and horizontal posi-tions under thermal loads between 5 W and 45 W. All the devices have operated satisfactorily when tested in accordance with the behavior of the thermal re-sistance. The heat pipes were the best among the tested devices and the best posi-tion was vertical.