PURPOSE: To form a miniature via-hole with good accuracy and simply by a method wherein, after copper has been plated electrolessly on the whole surface of a substrate including a through hole, a photosensitive resist is coated electrically and the coated resist is patterned.
CONSTITUTION: After a through hole 2 has been made in a desired position of a glass epoxy copper-lined and laminated substrate 1, copper is plated 3 electrolessly on the whole surface of the substrate 1 including the inside of the through hole 2. Then, the substrate 1 is immersed in a tank (not shown in the figure) which is filled with a photosensitive resist material, and an anode is formed; a photosensitive resist 4 is formed by electrical precipitation. In succession, the resist 4 is exposed to light and developed; an etching mask is formed; the exposed copper is removed. Then, the mask is removed; after that, a solder resist 5 is formed; copper is plated chemically. By this setup, it is made possible to manufacture a high-density printed-circuit board having a miniature via-hole by a simple process and with good accuracy.
KONDO YOSHINORI
TSUTSUMI KATSUNORI
