| 摘要 |
PURPOSE:To manufacture a multilayer wiring board having six or more conductor layers at high productivity at low cost by a method wherein internal layer sheets and prepregs are positioned and fastened one another by the specified method and copper clad external layer sheets are put on both sides of said fastened internal layer sheets and prepregs and finally formed by heating and pressing under vacuum. CONSTITUTION:After indexing holes are respectively bored at the predetermined positions of a plurality of internal layer sheets, on both face and back of which wiring patterns are respectively formed, and of prepregs, metal rivets, at the tip of a round- bar-like solid part of each of which a hollow part is formed axially for caulking, or eyelet rivets are inserted in the indexing holes so as to position and fasten the sheets and prepregs by caulking these hollow parts. Next, copper clad external layer sheets are put on both sides of said fastened internal layer sheets and prepregs and formed by heating and applying the pressure of 5-35kg/cm<2> under the vacuum of 60 Torr or less in order to obtain a multilayer wiring board. Thus, the change of the board thickness during forming is small, neither bending nor deformation of the eyelet occurs and no misregistration between internal layer conductor layers develops, resulting in enabling manufacture of highly accurate multilayer wiring board. |
