| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the boring process of a fine hole and desmear treatment by forming a conduction part, which conductively connects front and rear wiring patterns in one circumferential edge part of a device hole and a circumferential edge part of a package outer circumferential hole enclosing a device hole. SOLUTION: A large number of device holes 11 and a package outer circumferential hole 12 enclosing each of the device holes 11 are punched out in a tape-like base film simultaneously. Copper plating is applied to the circumferential edge part of the device holes 11 and the package outer circumferential hole 12, and a photoresist coat is applied thereon. Then, it is subjected to exposure, development and etching and a wiring pattern are formed, and an inner circumferential conduction part 15 is formed in the circumferential edge part of the device hole 11, and an outer circumferential conduction part 16 is formed in the circumferential edge part of the package outer circumferential hole 12. Thereby, a boring process of a fine hole and desmear treatment can be dispensed with. |
