To prevent a circuit and a post from being damaged by depositing a metallic resist in the remaining part of a copper film for post lower circuit within an upper and lower conductor layer, removing a part for forming a post only thereafter, and removing the copper by such chemicals that can remove only a copper after depositing a metallic resist layer for protecting a post.
An upper dry film resist 108 for post-plating is laminated on a metallic resist 107 and a dry film resist 103, and after it has been exposed, the metallic resist 107 in the unwanted part of an opening 109 for plating posts is removed by such chemicals that can melt a metallic resist but not a copper or a dry film. A post 110 is formed through electrolytic copper plating within the opening 109 and a metallic resist 111 such as tin, etc., thereon. Then an unwanted copper part in a conductor circuit 112 in the lower part of the post 110 is removed with such chemicals that is incapable of dissolving a metallic resist but can dissolve copper. Since the upper part of a circuit and a post is protected with a metallic resist, the circuit or post can be prevented from being damaged.
TAKAHASHI YOSHIRO
KARASUNO YUTAKA
NAKAKUKI MINORU
OKI ELECTRIC IND CO LTD
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