PRINTED CIRCUIT BOARD AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a printed circuit board having secure interlayer connection by conductive paste, a low electric resistance and highly reliable connection, and to provide a method of manufacturing the printed circuit board.SOLUTION: A masking film 24 is stuck to a surface of copper foil 13 on one side of an insulating layer 12, a face where the masking film 24 is laminated is irradiated with first laser light L1 and an opening 26 is formed in the masking film 24 and the copper foil 13. A via hole 16 is formed in the insulating layer 12 by second laser light L2 with a spot diameter D3 larger than a diameter D1 of a ridgeline of a bump part 26a formed at the peripheral edge of the opening 26 of the masking film 24. The via hole 16 is filled with the conductive paste 18 and respective circuit wirings 13a and 14a are electrically connected.