Calculation of thermal resistance for air-cooling heat sink of power semiconductor parts

By an analysis of the operation of heat sink,a new method is proposed for the calculation of thermal resistance for air-cooling heat sink of power semiconductor parts.For the calculation,there are 2 steps: internal heat transmission and the surface heat diffusion.The basic formulae for each step are provided,and the results are verified by using the heat sink thermal resistance curve provided by the manufacturer.The calculation result shows that this method is easy and accurate.