| 摘要 |
PURPOSE:To realize a through hole plating method for the inner layer board of double-sided wiring board or a multilayer wiring board employing a polyimide based material by repeating electrolytic copper plating step at least two times after drilling a board. CONSTITUTION:Holes are drilled through a board made of polyimide, maleimide, or modified material thereof, a board made of a combination or more than one material selected from aforementioned material, or a board made of a combination of one or more material selected from aforementioned materials and one or more material selected from other materials. Surface of insulator to be exposed is then subjected to pretreatment of electroless copper plating. Thickness of the electroless copper plating is set preferably in the range of 1-20mum so that the plating is not removed during next pretreatment of electroless plating. First time electroless copper plating is followed by second time pretreatment of electroless plating and electroless copper plating. |
