Electroless silver plating
AssigneeHoneywell International Inc.
InventorsAlexander S. Kozlov, Thirumalai Palanisamy, Dave Narasimhan
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Abstract
This invention relates to electroless plating of silver onto a substrate, an aqueous silver plating bath, a process for plating a uniform coating of silver onto various substrates using an electroless plating composition, and a silver plated article formed therefrom. The plating bath neither contains nor generates toxic or flammable substances or substances that may contaminate the silver coating. By avoiding strong complexing agents, virtually pure silver may be precipitated from the bath by simple boiling. Silver electroless autocatalytic plating bath consists of silver nitrate, ammonium hydroxide and hydrazine hydrate.
Claims28
An electroless plating composition comprising an aqueous solution comprising:
- a) a silver salt;
- b) ammonium hydroxide;
- c) ammonium carbonate and/or bicarbonate;
- and
- d) hydrazine hydrate.
A process for plating a substrate comprising:
- A) providing a plating composition comprising an aqueous solution comprising:
- i) a silver salt;
- ii) ammonium hydroxide;
- iii) ammonium carbonate and/or bicarbonate;
- and
- iv) hydrazine hydrate;
- and
- B) contacting a substrate with the plating composition for a sufficient time and under conditions sufficient to plate metallic silver onto the substrate.
A process for plating a substrate comprising:
- A) providing a plating composition comprising an aqueous solution comprising:
- i) a silver salt;
- ii) ammonium hydroxide;
- iii) ammonium carbonate and/or bicarbonate;
- and
- iv) hydrazine hydrate;
- B) immersing a substrate into the plating composition for a sufficient time and under conditions sufficient to plate metallic silver onto the substrate;
- and
- C) removing the substrate from the plating composition.
An article comprising a substrate immersed in a composition comprising an aqueous solution comprising:
- a) a silver salt;
- b) ammonium hydroxide;
- c) ammonium carbonate and/or bicarbonate;
- and
- d) hydrazine hydrate.
Dependencies are inferred from the claim text.