| 摘要 |
PURPOSE:To obtain satisfactory and predetermined through-hole connecting reliability by forming an oxide film on a metal part exposed at least in a hole prior to plating. CONSTITUTION:Since various processing agents are absorbed or adhered to the surface of copper during pretreating in normal plating, a clean state is not always held. That is, it is known that a copper oxide is not plated by electroless plating but dissolved in plating solution. Then, copper oxide 6 is previously formed in a hole 5. Accordingly, the oxide 6 is dissolved at a moment in which it is dipped in electroless copper plating solution to form a clean copper surface, and an electroless copper plating 7 can be formed epitaxially on a board copper. Thus, a through-hole connecting reliability is improved, and at least connecting malfunction of peeling at least between the board copper and electroless copper is reduced. |
