The thermal impedance Zth(jω) has been measured for the junction of a transistor mounted on a cooling fin. The setup was put inside a chimney in order to enhance the natural convection cooling. From the thermal impedance Zth(jω) the influence of the chimney on the reduction in thermal resistance Rth=Zth(jω=0) is clearly visible. A maximum improvement of almost 20% has been observed experimentally. Measuring the thermal impedance as a function of the angular frequency ω provides specific information about the thermal path being influenced by the chimney.

Issue Section:
Technical Briefs
Keywords:
cooling, natural convection, semiconductor device packaging, thermal conductivity, thermal management (packaging), thermal resistance, transistors
Topics:
Cooling, Natural convection, Thermal resistance, Transistors, Junctions
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