Development of an Apparatus to Diagnose Electronic Instruments from External Thermal Measurements

As electronic devices are miniaturized and their performances are accelerated rapidly, design of a cooling system becomes one of the most important issues. This paper presents development of an apparatus to diagnose a laptop PC from external thermal measurements. The PC is meshed using the finite element method, and the averaged thermal conductivity of each finite element is estimated from the measurement data. In order to obtain sufficient experimental sets, couples of thermal images are obtained while a hot plate is applying the constant various heat input from the bottom side of the PC. An estimation based on the least square method is presented. By minimizing the temperature differences between measured data and calculated ones, the thermal conductance for each finite element is estimated.