METHOD OF MANUFACTURING MULTILAYER PRINTED BOARD

摘要

PROBLEM TO BE SOLVED: To suppress disconnections and short circuits caused by the depression of resin-bonded copper foil due to resin pieces or foreign matters produced in a process and left on the copper foil or steps produced by removed copper foil sections in a laser beam machining process. SOLUTION: Resin pieces and foreign matters left on the resin-bonded copper foil are prevented from sticking to the foil or being transferred and causing the depression of the foil by taking the resin pieces and foreign matters in a thermoplastic resin sheet by laying the sheet on the foil and pressing the sheet against the foil. In addition, the area of the copper foil which is removed for making via wiring holes is reduced to a size that will not exert influence on wiring formation by using the thermoplastic resin sheet as the etching resist of the copper foil after holes are made through the sheet with a laser beam.