| 摘要 |
PURPOSE:To improve adhesive properties of a solder resist by forming a solder- plated film by electroless plating in a uniform thickness on a conductive circuit. CONSTITUTION:The wall face of a through hole 3 and the surface of an adhesive layer 2 are made chemically hydrophilic, chromium ions are neutralized and made nontoxic. Then, after it is washed with water, the surface of the layer 2 and the wall face of the hole 3 are catalyzed. Then, after it is washed with water, it is dipped in an electroless copper plating solution, thereby forming an electroless copper plated film 4. Thereafter, a first plating resist 5 is screen printed in a reverse printing block state, and thermally dried. Then, an electric copper plated film 6 is precipitated. Subsequently, it is dipped in electroless solder plating solution, thereby precipitating an electroless solder plated film 7, a second plating resist 8 is screen printed on a whole face except the edge of the through hole on the surface of a substrate 20, and an electric solder plated film 9 is precipitated at the edge of the hole 3 on the wall face of the hole 3 and the surface of the substrate 20. Then, the resists 5, 8 of the surface of the substrate 20 are removed, and solder resist 10 is screen printed on the whole surface except the edge of the hole of the substrate 20. |
