Numerical Simulation of Conjugate Heat Transfer From Multiple Electronic Module Packages Cooled by Air

This paper reports on the numerical simulation of conjugate heat transfer from multiple electronic module packages (45 × 45 × 2.4 mm) on a printed circuit board placed in a duct. The dimensions of the modules are the same as a single module package previously studied. In the series arrangement, two module packages are installed on the center of the printed circuit board along the airflow direction. In the parallel arrangement, two and/or four module packages are installed normal to the airflow direction. In the numerical simulations, the interval between the module packages was varied and three values were considered (45, 22.5 and 9 mm). The variation of the printed circuit board thermal conductivity was also considered and 0.3, 3 and 20 W/m/K were used with the mean velocity in the duct also at three different values (0.33, 0.67 and 1 m/s). In order to derive a non-dimensional correlation from the numerical results, the concept of the effective heat transfer area previously used for a single module package was used for the multiple module packages. For the series arrangement, the effects of the interval on the effective heat transfer area are relatively low, and the numerical results can be summarized with the same correlation obtained from the single module package. On the other hand, the effective heat transfer area for the parallel arrangement is strongly affected by the parallel interval and the thermal conductivity of printed circuit board. When the interval increases, the temperature of the module packages greatly reduces as the thermal conductivity of the printed circuit board increases.