| 摘要 |
PURPOSE:To prevent the drop of throwing power by etching the electrolytic panel copper plated layer under the second resist film, which is removed with electrolytic solder plated layer as a mask, and a surface layer copper foil. CONSTITUTION:A through hole 23 is formed a through a multilayer printed wiring board 5 provided with a surface layer copper foil 4, and an electrolytic panel copper plated layer 31 is made on the multilayer printed wiring board 5. Next, a first resist film 32, where the through hole land pattern formation area 41 of the through hole 23 is opened, is formed in the multilayer printed wiring board, and a first electrolytic pattern copper plated layer 33 is made in the through hole 23 and at the through hole land pattern formation area 41. And a second resist film 34, which is opened in the specified pattern, is made in the circuit pattern formation area, and a second electrolytic pattern copper plated layer 35 and an electrolytic solder plated layer 36 are formed in a multilayer structure, and the second resist film 34 is removed. Furthermore, the electrolytic copper plate layer 31 below the second resist film 34 and the surface layer copper foil 4 are removed by etching. Hereby, the drop of the throwing power is prevented. |
