**Abstract**

Recent developments in the electronic equipment market have been very demanding on two important design parameters: the size of the equipment and the efficiency of the cooling system. Indeed, the race for more applications handling in reduced sizes in the case of smartphones requires the use of important amounts of energy in tiny volumes. Similar constraints are encountered in the design of the new generation of vehicles (electric cars, hybrid vehicles, high-speed trains, airplanes), which impose the use of highly integrated electronic structures, resulting in significant power densifications (up to several hundred Watts/cm<sup>2</sup> ). In some CPU boards, the power generated per unit chip area is in the order of 500 kW/m2 . Cooling of such boards requires low volume and lightweight heat exchangers to transfer tremendous amounts of heat. The same situation is encountered for most newly developed demotics' equipment. This chapter reviews available state-of-theart technologies for electronic equipment cooling, including *passive* and *active techniques*, as well as *one and two-phase heat exchange*. Directions for the design of the different heat exchangers will also be given.

**Keywords:** passive cooling, active cooling, spray cooling, refrigerated cooling, heat pipes, cold plates, vapor chambers, microchannel heat sinks, thermal resistance, carrying capacity, thermal program, effective thermal conductivity
