| 摘要 |
PURPOSE:To form a wiring board having excellent reliability on connection and high wiring density by forming structure in which the connection area of a through-hole and a circuit conductor is increased, boring a hole as the through-hole after the completion of the machining of the circuit conductor and shaping a conductor continued to the inwall of the through-hole and the periphery of the hole as the through-hole. CONSTITUTION:A protective film 5 is formed onto the whole surface of an insulating substrate 1 having circuit conductors 3, a hole 2a and a hole 2b are bored, and the protective films 5 in the peripheries of the hole 2a and the hole 2b are removed within desired ranges. Circuit conductors 4a and 4b are shaped to the whole surfaces of the inwalls of the hole 2a and the hole 2b and sections from which the protective films 5 are removed. Consequently, the connection areas of the through-holes and the circuit conductors 4a, 4b are increased, and the wirings of the circuit conductors 4a, 4b are designed easily. The holes are bored, all the circuit conductors 4a, 4b are shaped and the through-holes are formed, thus simplifying a process, then forming a wiring board having excellent reliability on connection and high density. |
