Abstract
The PCB in high density packaging environment often provides a critical heat conduction path from the package to the electrical connectors or the system enclosure that serves as a solid heat sink at the edge of the PCB. Two PCB samples are subject to heat conduction analysis; they are rectangular bar specimens cut out from the PCB, one measuring 6mm (L)×0.5mm (W)×1.27mm (H_<PCB>), and the other 12.35mm (L)×1.27mm (W)×1.27mm (H_<PCB>). Numerical solutions are obtained taking into account the full details of the via zone structures. Classical solutions are also obtained for a two-zone continuum model having different sets of orthotropic thermal conductivities for the via zone and the remaining zone. The thermal conductivities in the continuum model are varied to bring the key temperatures to those obtained by the numerical analysis.
