MULTI-LAYER COPPER-CLAD BOARD WITH GOOD LASER DIRECT BORING PROCESSABILITY

摘要

PROBLEM TO BE SOLVED: To obtain a low cost multi-layer copper-clad board having a reference mark for boring formed thereon and having good mass productivity and workability for forming a small diameter through hole and/or a blind via-hole by directly irradiating the multi-layer copper-clad board with a laser beam. SOLUTION: The multi-layer copper-clad board is manufactured by forming a reference mark at the end part of inner layer copper foil and forming a lamination so that the laminated material does not cover the reference mark. A small diameter through hole and/or a blind via-hole can be bored with good position accuracy by directly irradiating the multi-layer copper-clad board with a laser beam while reading the exposed reference mark without removing the copper foil and the insulating layer on the reference mark after forming the lamination. The hole can be formed with good mass productivity and workability at a low cost.