| 摘要 |
PROBLEM TO BE SOLVED: To provide a multi-layer printed wiring board wherein an accurate alignment mark part is formed. SOLUTION: A multi-layer printed wiring board 1 is provided wherein an outer-layer laminating plate 3 is laminated on the surface of an inner-layer laminating plate 2 where an inter-layer pattern is formed, a photo-resist 4 is coated on its surface after an outer-layer pattern is formed, and exposure and development are performed with a mask film 5 to form an alignment mark part 6. Here, at a part of the inner-layer laminating plate 2 corresponding to a surrounding part of the contour part of the alignment mark part which is to be formed, a dummy pattern 8 processed with a black-oxidation is provided, since the dummy pattern 8 absorbs light ray L at exposure, the irregular reflection especially from the internal material of the inner-layer laminating plate 2 which is affected much is eliminated, for forming an accurate alignment mark part. |
