MANUFACTURE OF MULTILAYER PRINTED CIRCUIT BOARD

PROBLEM TO BE SOLVED: To upgrade a positioning accuracy between adjacent circuit layers by aligning the adjacent circuit layers with a standard mark provided at a position not superposed with the circuit layer as a reference. SOLUTION: Reference marks M1a, M1b are formed at a position where the marks M1a, M1b are superposed on first circuit layers 1a, 1b (circuit board A). Then, second circuit layers 2a, 2b (circuit board B) are manufactured. The second layer is aligned at the marks M1a, M1b as reference positions. Reference marks M2a, M2b are formed at positions to be superposed with the marks M1a, M1b on the layers 2a, 2b, and reference marks N2a, N2b are formed at positions where the both are not superposed and not superposed with any of the marks M1a, M2a, M2a, M2b. Then, copper foils 4a, 4b are respectively laminated on the circuits 2a, 2b. Positions for forming through holes 6a, 6b of only insulating layers.