Cooling Electronics by Direct Contact With Liquids

Abstract Electronic components have reached such miniature sizes that numerous of these components can be mounted in a single module (less than 1 × 1 cm). Failure of these modules while in operation is attributed to thermal stresses caused by high heat fluxes. The objective is to find alternate higher efficiency method for cooling these electronics. There is an abundance of research and applications based on air cooling by natural and/or forced convection. Cooling by indirect contact with liquids such as the use of cold plates, microchannel cooling, and heat pipes has been used for many applications. In addition, thermoelectric cooling has been utilized. Also, research has been reported on phase change materials cooling, spray cooling, jet impingement cooling, and droplet electrowetting. But not much work reported on cooling by using liquids in direct contact with electronics during their operation. Consequently, the objective of this article is to design and construct an apparatus to test electronic cooling via direct contact with liquids. Properties of liquids researched, as well as the rational for choosing the electronics we tested are given in this article. Description of the testing apparatus with circuitry completely immersed in liquid while operating is discussed. In addition, short- and long-term tests were performed. Details of the tests and the results are discussed in this article.