| 摘要 |
PURPOSE:To eliminate front and rear displacements in theory and to largely improve yield by forming through holes at common clearance sections to a power source ground layer. CONSTITUTION:A double-sided copper-clad laminate 2 is prepared using a copper foil 1 of a predetermined thickness, and drilled to make through holes which form common clearance sections 3. Then, noncommon clearance sections 4 are formed by a photoetching method to obtain an inner layer substrate 5 which becomes a power source ground layer. After the substrate 5 obtained in this manner is thermally laminated with an outer conductor layer 7 through prepreg 6, a multilayer printed wiring board 8 is obtained by opening, through hole plating, etching. Thus, the load of drilling at the time of opening is reduced to suppress its wear. |
