A test section was designed and constructed to model air-cooled printed circuit boards containing integrated circuit components as proposed for Naval standard package designs. Thermal performance data are presented for air flow rates to 3.38 CFM across fiberglass/epoxy and aluminum core circuit boards, each containing nine resistor elements to simulate IC components. Hot spot areas on the boards are shown using both liquid crystals and thermocouple data. Results show that in designing such standard packages, care must be taken to avoid obstructions in the air flow path. These obstructions can cause poorly circulating flow regions near the circuit boards, leading to hot spots and poor thermal performance of the IC components. The use of an aluminum core circuit board can significantly reduce this hot spot problem. (Author)
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