Electroless plating process
OwnerRobert Duva, George Ondeckerinventors
Life of this patent
Estimating the term…
Abstract
Deposition of gold without the use of electric current is described. The system produces thick gold films without the use of strong reducing agents. Discontinuous land areas on high reliability printed wiring boards or ceramic circuits can be readily coated with gold to any desired thickness. Long lead glass-to-metal seals can be uniformly plated without distortion of the leads.
Claims21
An electroless plating process for plating gold on a substrate, the process comprising:
- immersing the substrate in an aqueous solution including:
- (a) potassium gold cyanide;
- (b) potassium hydroxide;
- (c) potassium cyanide;
- and
- (d) a weak stable organic acid or amino acid and a Ph stabilizer;
- maintaining said substrate immersed within said aqueous solution for a period of time sufficient to deposit a desired amount of gold on the substrate;
- and
- said solution being effectively free of strong reducing agents and said potassium cyanide being maintained in said solution in an amount providing an excess amount of free cyanide ions in said solution during said immersion of said substrate whereby said solution is effective to controllably deposit gold on said substrate.
An electroless plating process for plating gold on a substrate, the process comprising:
- immersing the substrate in an aqueous solution including:
- (a) potassium gold cyanide;
- (b) potassium hydroxide;
- (c) potassium cyanide;
- (d) a weak stable organic acid or amino acid;
- and
- (e) a pH stabilizer, said solution being capable of being operated at the boiling point of the solution without any deterioration or decomposition of system components;
- maintaining said substrate immersed within said aqueous solution for a period of time sufficient to deposit a desired amount of gold on the substrate;
- and
- said solution being free of strong reducing agents and said potassium cyanide being maintained in said solution in an amount providing an excess amount of free cyanide ions in said solution during said immersion of said substrate whereby said solution is effective to controllably deposit gold on said substrate.
An aqueous solution for the electroless plating of gold on a substrate, the aqueous solution comprising:
- potassium gold cyanide;
- potassium hydroxide;
- potassium cyanide;
- a weak stable organic acid or amino acid;
- a pH stabilizer;
- and
- said solution being effectively free of strong reducing agents and said potassium cyanide being maintained in said solution in an amount providing an excess amount of free cyanide ions in said solution during the immersion of a substrate in said solution whereby said solution is effective for controllably depositing gold on said substrate.
An electroless plating process for plating gold on a substrate, the process comprising:
- immersing the substrate in an aqueous solution including:
- (a) potassium gold cyanide;
- (b) potassium hydroxide;
- (c) potassium cyanide;
- and
- (d) a weak stable organic acid or amino acid and a pH stabilizer;
- maintaining said substrate immersed within said aqueous solution for a period of time sufficient to deposit a desired amount of gold on the substrate;
- and
- said solution being effectively free of strong reducing agents.
An electroless plating process for plating gold on a substrate, the process comprising:
- immersing the substrate in an aqueous solution including:
- (a) potassium gold cyanide;
- (b) potassium hydroxide;
- (c) potassium cyanide;
- (d) a weak stable organic acid or amino acid;
- and
- (e) a pH stabilizer, said solution being capable of being operated at the boiling point of the solution without any deterioration or decomposition of system components;
- maintaining said substrate immersed within said aqueous solution for a period of time sufficient to deposit a desired amount of gold on the substrate;
- and
- said solution being free of strong reducing agents.
An aqueous solution for the electroless plating of gold on a substrate, the aqueous solution comprising:
- potassium gold cyanide;
- potassium hydroxide;
- potassium cyanide;
- a weak stable organic acid or amino acid;
- a pH stabilizer;
- and
- said solution being effectively free of strong reducing agents.
Dependencies are inferred from the claim text.