An analytical model is developed to estimate the heat transfer performance of printed circuit board (PCBs). The PCB under study is the substrate for a ball-grid-array (BGA) package. Under the BGA, the PCB has a belt of densely populated through-vias that penetrate the laminate of horizontal copper and resin; outside the BGA-covered area the board is a copper/resin laminate and its surfaces are exposed to cooling air. Calculations are performed on a sample board having the dimensions 11×11 cm2 (footprint)×1.26 mm (thickness). The model of the board has two internal layers of continuous copper (0.03 mm thick) and through-vias under a 4.4×4.4 cm2 BGA package. The impacts of board design parameters on the temperature and the heat flow are presented; the parameters are the width of the insulation gap around the via, the area of copper coverage at the via bottom, and the population of vias.

Issue Section:
Thermal Issues in Emerging Technologies Theory and Applications, THETA
Keywords:
ball grid arrays, copper, heat conduction, integrated circuit design, integrated circuit packaging, laminates, printed circuits, resins, thermal management (packaging), printed circuit board, heat conduction, analytical modeling, through-vias, copper/rein laminate
Topics:
Copper, Flow (Dynamics), Heat, Heat conduction, Insulation, Laminates, Modeling, Printed circuit boards, Resins, Temperature, Thermal resistance, Plating, Dimensions, Design, Heat transfer
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