| 摘要 |
PURPOSE:To provide a multilayered printed board in which hollowing is reduced by applying hydrazine treatment on an electroless plating through-hole board. CONSTITUTION:The copper foil surface of internal layer in which a printed wiring net is formed as an intermediate layer is oxidized chemically to form a brown or black copper oxide surface thereon, and after multilayered lamination formation is performed, throughhole making, desmear treatment, electroless plating, and electrolytic plating are applied in sequence to obtain an outer-layer printed wiring net. Through the production method of multilayered printed wiring board including the above processes, the treatment of hydrazine solution is further added between the processes of electroless plating and electrolytic plating in order to reduce hollowing in the multilayered printed board. |
