| 摘要 |
With a multi-layer printed circuit bare board (1) has 2n circuit layers, where n is a natural number exceeding a unity, electrical connections are established between the (2i-1)-th layer (3, 21) and the 2i-th layer (5, 19), where i=1, 2, ...., n, by holes (37) which are created through insulation material layers (35) in between and filled with copper plating (39). Electrical connections are also accomplished between the 4i-th layer (13, 19) and the (4i-3)-th layer (3, 29) by holes (41) created through insulation material layers (35) in between and filled with copper plating (39). Higher dimensional accuracy and fewer process steps are achieved. <IMAGE> |
