Paper Title
THE ESTIMATIONOF MULTIPLE HEAT SOURCES FOR CHIPS MOUNTEDONA PRINTED CIRCUIT BOARD SIMULTANEOUSLY

Abstract
Abstract - The unknown magnitude of the spatially dependent volumetric heat generation of multiple encapsulated chips mounted on a printed circuit board (PCB) is estimated in the present three-dimensional steady-state inverse heat conduction–convection conjugated problem (IHCCCP). The conjugate gradient method (CGM) is used as the optimization tool because it does not require a priori information regarding the functional form of the unknown quantities, many unknowns can be corrected and estimated in each iteration, and accurate estimates can always be obtained. The results of estimating the heat generation of multiple chips are verified using numerical experiments with various inlet air velocities and measurement errors.They revealed that using exact measurements always produces accurate heat generation for chips and that the regular air velocity does not affect the estimates. Finally, it is concluded that because the inverse problem is ill-posed, the estimated heat generation of chips becomes less accurate as the measurement error increases. Keywords - Inverse Problem, Conjugate Gradient Method, Heat Source Estimation