| 摘要 |
PURPOSE:To improve the resistance to humidty of a module, by a method wherein, after a printed wiring board is once subjected to hole-sealing process, and a semiconductor chip os mounted, the whole surface of the printed wiring board except a heat dissipation part and an electrode terminal part of the chip is molded with epoxy resin to constitute a double-sealing. CONSTITUTION:Before electrode terminals 5 are arranged, a printed wiring board 1 is once impregnated with hole-sealing agent, by masking a semiconductor chip mounting part 2 and electrodes 4, and the whole surface of the printed wiring boad containing through-holes and excepting the semiconductor chip mounting part 2 and the electrodes 4 is subjected to a hole-sealing process. After the electrode terminals 5 are arranged on the printed wiring board 1, and a semiconductor chip 3 is mounted, the chip is sealed by a metal cap 7 to prevent moisture from permeating into the chip mounting part 2. Then epoxy resin powder is deposited on the whole surface excepting the metal cap 7 and the electrode terminals 5, and the whole surface of the printed wiring board 1 is uniformly covered with an epoxy resin layer 9. Thereby, the resistance to humidity of the whole surface of a module can be improved.
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