Method for electroless plating of tin and tin alloys

摘要

The invention relates to a method for electroless (immersion) plating of tin and tin alloys having a thickness of ‰¥ 1 µm as a final finish in the manufacture of printed circuit boards, IC substrates, semiconductor wafers and the like. The method utilizes an electroless plated sacrificial layer of copper between the copper contact pad and the electroless plated tin layer which is dissolved completely during tin plating. The method compensates the undesired loss of copper from a contact pad during electroless plating of thick tin layers.