Correlation of Heat Transfer Data to Film Thickness Data of the Thin Film Found in Spray Cooling
As electronic circuit design and packaging technology progresses, the density and power levels of electronic components is increasing at a nearly exponential rate. The higher heat loads dissipated by these devices are nearing the limits of traditional cooling techniques. One method capable of removing heat fluxes as high as 100 W/cm2 is spray cooling. This process involves the impingement of liquid droplets onto a heated surface, forming a thin two-phase film. In order to create reliable models of the heat transfer during spray cooling, the behavior of the film must be understood. This paper presents an investigation into the behavior of the thin film found in spray cooling. A study was performed to relate experimental measurements of the heat transfer coefficients to experimental measurements of film thickness as they vary spatially over a die surface. Both a single nozzle and a multi-nozzle array were investigated. Measured heat transfer coefficients ranged from 0.2 to 1.2 W/m2K and film thicknesses ranged from 90 to 300 μm.