High Elongation Electroless Copper Process

Abstract

An electroless copper deposition composition, comprising: (a) a source of copper ions; (b) a chelator; (c) a source of alkalinity; (d) a reducing agent; (e) nickel ions; (f) a bipyridine; (g) optionally, an additional stabilizer; and (h) optionally, a water soluble polymer. The electroless copper deposition composition can be used to deposit a ductile copper deposit on a substrate that exhibits high % elongation and high tensile strength.

Description

FIELD OF THE INVENTION[0001]The present invention relates generally to electroless copper plating solutions capable of producing ductile copper deposits and methods for producing ductile copper plating deposits by electroless copper plating.BACKGROUND OF THE INVENTION[0002]Electroless copper plating baths are widely used in metallization industries for depositing copper on various types of substrates. For example, in the manufacture of printed circuit boards, electroless copper baths are used to deposit copper on walls of through-holes and circuit paths as a base for subsequent electrolytic copper plating. Electroless copper plating is also used in the decorative plastics industry to deposit copper on non-conductive surfaces as a base for further plating of copper, nickel, gold, silver and other metals.[0003]Commercial electroless copper baths generally contain water-soluble divalent copper compounds, chelating agents or complexing agents, reducing agents, and various other additive...

AI Technical Summary

Benefits of technology

The present invention provides an electroless copper plating solution that can create a ductile copper deposit on an underlying substrate. This deposit has high elongation and strength.

Problems solved by technology

Therefore, stress is created in the copper which can cause cracking of the deposit, which can result in failure of the circuit board.

In practice, current electroless copper solutions have only been capable of achieving an elongation percentage of about 2-3%, and no electroless copper systems (MID) electroless copper systems currently on the market has been able to offer high elongation.

However, Dutkewych requires that the composition contain cyanide ions in order to achieve the desired result which is not desirable from an environmental standpoint.