| 摘要 |
PURPOSE:To realize a high wiring density, make an electric continuity test of the surface and rear of a circuit board easy and improve an yield by a method wherein the printed wiring on the surface of an insulating board and the wiring in the through-hole of the insulating board are formed simultaneously by a vacuum suction method. CONSTITUTION:A through-hole 12 is formed in an insulating board 11. Then conductive paste is provided on the surface of the board 11 and a first printed wiring 13 is formed on the surface of the board 11 by a vacuum suction method. At the same time, a second printed wiring 14 which is the continuous extension of the first printed wiring 13 and reaches the rear of the board 11 is formed on the inner wall of the through-hole 12. Then a first printed wiring 15 is formed on the rear of the board 11 by a vacuum suction method in the same way so as to have its end part overlap the second printed wiring 14 extended to the rear of the board from the through-hole 12. As a result, a conductive through-hole 16 which connects the first printed wirings 13 and 15 on both the surfaces of the board 11 to each other is formed in the through-hole 12 and a printed wiring board is formed. |
