Abstract
Natural convective heat transfers on IC pachage type resistance elements were made clear by the experiments in silicone oil. Temperature distribution and flow pattern of natural convection around resistance elements on the vertical circuit board were made visiable with the liquid crystal particle suspension method.
Natural convection of resistance elements were shown by the relation between the heat transfer coefficient and temperature difference. The velocities of silicon oil around the elements were measured with the path lines of liquid crystal particles. The heat transfer characteristic of 30mm space of resistance elements and 6mm space were the same approximately and the mean velocities were not different in the two cases.
