MULTILAYERED COMPOSITE WIRING BOARD AND ITS MANUFACTURE

摘要

PURPOSE:To provide an inexpensive high-density multilayered composite wiring board by constituting the wiring board in such a way that part of a substrate housing multilayered wiring is branched at flexible wiring layers and the part of the substrate. CONSTITUTION:As shown in the figure, part of a substrate housing multilayered wiring is branched at flexible wiring layers and the part of the substrate. A base material composed of glass fabric and a thermosetting resin is used for the part of the substrate except the extended part of the flexible wiring layers. It is possible to form an interlayer connecting hole through the base material so as to electrically connect the wiring which is flush with the flexible wiring layer to wiring immediately below the wiring layer. Therefore, a multilayered wiring board can be constituted in such a way that the interlayer connecting hole for IVH connection useful for increasing the wiring density can be easily formed. In addition, the flexible wiring layer part can be easily connected to another wiring board or electric parts.