Patent ID: 6119335
Filing Date: 2000-09-19
Classification: H05K,Y10T

Abstract:
A method for manufacturing a build-up type multi-layer printed circuit board, with a insulating layer being stacked upon a copper clad laminate CCL with a circuit pattern formed thereonthe method comprising the steps of:stacking a resin-clad copper foil (RCC) on said CCL after forming a first printed circuit layer having a first circuit pattern, and heating and pressing this structure;forming a via hole in said RCC thus heated and pressed, for forming inter-layer connections;carrying out a plating on said board with a via hole formed therein, to form an electrically conducting layer for inter-layer electrical connections;forming a second printed circuit layer having a second circuit pattern on said board thus plated; andforming a protecting layer on said board after forming said second printed circuit layer,wherein said via hole for connecting said first circuit pattern of said first printed circuit layer to said second circuit pattern of said second printed circuit layer is formed by irradiating beams of an Nd-YAG laser at a predetermined position to remove all copper foil of said RCC, and then, irradiating beams of a CO.sub.2 laser to a copper-foil-removed position to remove all residual resin of said RCC.