| 摘要 |
PURPOSE:To prevent remaining of non-etchant part by providing through holes at four corners of an inner layer board, further providing copper foil patterns for printing pilots at the same positions as those of the holes on front and rear surfaces, and using a distance between the circumference of the hole and the outer periphery of the pattern as an index of aligning front and rear inner layer patterns on, the front and rear surfaces. CONSTITUTION:Through holes 5 are formed at four corners of an inner layer board 1 as printing pilots by drilling. Pilot patterns 6 or an inner layer pattern film in which a circuit pattern region 4 corresponding to the center of the board 1, a plurality of dot patterns 3 corresponding to peripheral edge regions 2 and the patterns 6 are arranged, are provided on the surface of the board 1 to match the holes 5. The film is so aligned that the holes 4 formed at the four corners fall within the inner circumference of the patterns 6 to align the front and rear surfaces. Thus, remaining of non-etchant part is eliminated to prevent a short-circuit between wirings. |
