DRILLING THROUGH MULTILAYER PRINTED WIRING BOARD AND FORMATION OF LAND PATTERN

摘要

PURPOSE:To provide a longer life to a drill which is used for drilling of a multilayer printed wiring board by a method wherein when forming land patterns on internal layer pattern-formed substrates which constitute the multilayer printed wiring board, only the land patterns that are connected to wiring patterns are formed, and drilling is performed after laminate-molding of substrates for internal layer use and substrates for external layer use with prepregs put between the substrates for internal layer use and external layer use. CONSTITUTION:On internal layer pattern-formed substrates 10 which constitute a multilayer printed wiring board 14 which is not yet subjected to drilling, only such land patterns 11 as are connected to wiring patterns 12 are formed at the places corresponding to the places where through holes 9 are formed. When drilling the multilayer printed wiring board 14 for the through holes, the holes are made with a drill 15, with the drill 15 passing through a copper foil.