Heat transfer in evaporation in dielectric liquid films in different atmospheres using silicon testchips

A possible solution for cooling a large silicon detector system is discussed. The idea is to use evaporation cooling from liquid films deposited directly on the VLSI circuits. The intention is to feed liquid to each individual VLSI, using a combination of a liquid pipe line and a wick structure. The liquid which is deposited on the VLSI is then evaporated into an atmosphere consisting of vapor and possibly nitrogen. The heat transfer from liquid films deposited on silicon test chips is reported. Both pure vapor and a mixed vapor and nitrogen atmosphere have been used. The total pressure and thereby the liquid saturation temperature was varied during the different experiments. To increase the heat transfer coefficient at low heat fluxes, different modifications of the silicon surface were introduced in some of the experiments