| 摘要 |
PROBLEM TO BE SOLVED: To achieve fine machining of, for example, a lead frame by forming a photoresist film on a plated film which is formed by covering an insoluble metal on a substrate for an etching liquid and forming a plated film pattern using a photoresist pattern. SOLUTION: Silver which is insoluble and can be plated to an etching liquid should be used for the plating operation of the substrate of a lead frame. Plating should be electrically deposited for a solution where a plating material is dissolved. After forming a plating film 32 on both upper and lower surfaces of a substrate 31 and forming a photoresist film 33 on it again, a mask is covered before exposure and development, thus forming a photoresist pattern. A plated film pattern using a photoresist pattern is formed by applying a current in opposite direction from plating, thus forming a plated film pattern 32A with the same pattern as a photoresist pattern 33A. |
