Atotech Deutschland Gmbh

Christian Ohde

Heiko Brunner

Dirk Rohde

Lars Kohlmann

Sven Lamprecht

Kai-Jens Matejat

Olivier Mann

Andreas Kirbs

Bernd Roelfs

Stefanie Ackermann

Jan Sperling

Agnieszka Witczak

Timo Bangerter

Angelo Ferro

Andre Schmökel

A method of forming a solderable solder deposit on a contact pad, comprising the steps of providing an organic, non-conductive substrate which exposes said contact pad under an opening of a first non-conductive resist layer, depositing a conductive layer inside and outside the opening such that an activated surface results, thereby forming an activated opening, electrolytically depositing nickel or nickel alloy into the activated opening such that nickel/nickel alloy is deposited onto the activated surface, electrolytically depositing tin or tin alloy onto the nickel/nickel alloy, with the proviso that the electrolytic deposition of later steps results in an entirely filled activated opening, wherein the entirely filled activated opening is completely filled with said nickel/nickel alloy, or in the entirely filled activated opening the total volume of nickel/nickel alloy is higher than the total volume of tin and tin alloy, based on the total volume of the entirely filled activated opening.

Method of forming a solderable solder deposit on a contact pad

The present invention relates to aqueous acidic plating baths for copper and copper alloy deposition in the manufacture of printed circuit boards, IC substrates, semiconducting and glass devices for electronic applications. The plating bath according to the present invention comprises copper ions, at least one acid and an ureylene polymer comprising amino residues on both termini and which is free of organically bound halogen. The plating bath is particularly useful for filling recessed structures with copper and build-up of pillar bump structures.

Copper plating bath composition

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Berlin, Germany

Christian Ohde