Sheet for printed wiring board, method of forming via, resin sheet having filledvia, printed wiring board and method of manufacturing the same

摘要

The present invention provides a printed wiring board-forming sheet comprising a resin sheet having a through hole in the thickness direction and a metal chip inserted in the through hole, and a process for producing the sheet. The sheet is produced by placing a resin sheet and a conductive metal sheet in this order on a die base having a die hole, performing punching from the conductive metal sheet side to form a punched hole in the conductive metal sheet and to form a punched hole also in the resin sheet, and inserting the punched conductive metal chip in the through hole of the resin sheet. By the insertion of the conductive metal chip in the through hole, the front and back surfaces of the sheet can be electrically connected to each other. If the conductive metal chip is so inserted that its tip protrudes from the surface of the sheet and if a large number of such substrates are laminated, electrical connection in the thickness direction can be readily made by virtue of the protruded conductive metal chips, and a multi-layer board can be readily produced.