Abstract
An experimental investigation is made on natural air cooling of five vertical parallel IC boards with equal interval and the same sizes (285 hx237 w mm 2) of each board, where gap between the boards ranges 9.8 to 34.8mm and heat generated per each board from 3.5 to 16.0W. The temperature fields among boards are visualized be Mach-Zehnder Interferometer in the three different regions to show the effects of packages, gaps and heat fluxes. The surface temperatures of packages and boards are also measured by copper-constantan thermocouples. Discussions are made by comparing the local Nusselt numbers obtained with the previous correlation.
