摘要 |
A printed wiring board with either a pin grid array, a ball grid array, a land grid array, etc. of electrical contacts is prepared with a heat sink attached in the usual manner. A passage is provided either in the printed wiring board or in the heat sink so that during the transfer molding process, fluid molding compound passes latitudinally under the heat sink into a cavity below the heat sink. The mold is provided with a biased plug that exerts pressure on the heat sink or printed wiring board to prevent molding compound from covering the heat sink. The biased plug also accommodates variations in the thickness of the printed wiring board.
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