| 摘要 |
A printed wiring board and method for producing the same, in which an upper-surface pattern is readily formed, and a lower-surface metal foil is hardly damaged when a blind via hole is made by a laser beam. A lower- surface metal foil (220) is provided over the lower surface of an insulating sheet (5), and an upper-surface metal foil (210) thinner than the lower-surface metal foil (220) is provided over its upper surface. An open hole (213) is made in the upper-surface metal foil in a position corresponding to the area (35) where a blind via hole is formed. A laser beam (8) is projected onto the area (35) through the open hole (213) to make a blind via hole (3) the bottom of which is the lower-surface metal foil. A metal plating film (23) is formed on the inner wall of the blind via hole (3). Upper- and lower-surface patterns (21, 22) are formed by etching. |
