| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compact dew preventing structure of a semiconductor package, by providing airtight covers in the regions where the temperatures of the module mounting surface and the rear surface of its multilayer printed circuit board become not higher than the dew point temperature of the ambient air, and by performing through the same air flow cooling of electronic parts mounted on the regions of its multilayer printed circuit board which are outside the airtight covers and heating the airtight covers. SOLUTION: After mounting on a multilayer printed ciruit board 1 a multi- chip module 2 for integrating LSIs thereinto and other electronic parts, airtight covers 7, 8 formed out of such a thermally conductive material as aluminum and copper are provided in the module mounting surface and the rear surface of the multilayer printed circuit board 1 to form hermetically sealed space 12, 13 by an O-ring 9, sealing members 10, and clamping bolts 11. Further, cooling of the electronic parts mounted on the regions of the multilayer printed circuit board 1 which are present outside the airtight covers 7, 8 and heating of the airtight covers 7, 8 are performed through the same air flow. Thereby, a compact dew-drop preventing structure is made possible. |
