Methods And Compositions For Depositing Silver Onto A Metal Surface
The current method and composition relate to depositing silver onto a metal surface using an acid selected from the group consisting of salicylic acid and salicylic acid derivatives; a source of silver ions; and an additive selected from the group consisting of polyethylene glycol, a block copolymer of polyethylene glycol and polypropylene glycol, polypropylene glycol, block copolymers based on ethylenediamine as a core derivatives of any of the foregoing and mixtures of any of the foregoing.
1 . A silver deposit solution comprising:
an acid selected from the group consisting of salicylic acid and salicylic acid derivatives;
a source of silver ions; and
an additive selected from the group consisting of polyethylene glycol, a block copolymer of polyethylene glycol and polypropylene glycol, polypropylene glycol, block copolymers based on ethylenediamine as a core derivatives of any of the foregoing and mixtures of any of the foregoing.
2 . The silver deposit solution of claim 1 further comprising a mineral acid.
3 . The silver deposit solution of claim 2 wherein said mineral acid is nitric acid.
4 . The silver deposit solution of claim 3 further comprising a chelator.
5 . The silver deposit solution of claim 4 wherein the chelator is selected from the group consisting of N-(2-hydroxyethyl)ethylenediaminetriacetic acid and its salts.
6 . The silver deposit solution of claim 1 wherein said acid is 3,5-dinitro salicylic acid.
7 . The silver deposit solution of claim 1 wherein said additive is a block copolymer of polyethylene glycol and polypropylene glycol.
8 . The silver deposit solution of claim 1 wherein the source of silver ions is a silver salt.
9 . The silver deposit solution of claim 1 wherein the silver deposit solution is non-foaming.
10 . The silver deposit solution of claim 1 wherein the silver deposit solution is low foaming.
11 . The silver deposit solution of claim 1 further comprising a surfactant.
12 . The silver deposit solution of claim 11 wherein said surfactant is a phosphate ester surfactant.
13 . The silver deposit solution of claim 11 wherein said surfactant is a phosphate ester of tridecyl alcohol ethoxylate.
14 . A process of depositing silver onto a metal surface, comprising:
providing a metal surface; and
applying a silver deposit solution to the metal surface, the silver deposit solution comprising;
an acid selected from the group consisting of salicylic acid and salicylic acid derivatives;
a source of silver ions; and
an additive selected from the group consisting of polyethylene glycol, a block copolymer of polyethylene glycol and polypropylene glycol, polypropylene glycol, block copolymers based on ethylenediamine as a core, derivatives of any of the foregoing and mixtures of any of the foregoing.
15 . The process of depositing silver onto a metal surface of claim 14 wherein the metal surface is copper.
16 . The process of depositing silver onto a metal surface of claim 14 wherein the metal surface is on a printed wiring board.
17 . The process of depositing silver onto a metal surface of claim 14 wherein the metal surface is positioned vertically.
18 . The process of depositing silver onto a metal surface of claim 14 wherein the silver deposit solution is sprayed on the metal surface.
19 . The process of depositing silver onto a metal surface of claim 14 wherein the silver deposit solution is non-foaming.
20 . The process of depositing silver onto a metal surface of claim 14 wherein the silver deposit solution is low foaming
21 . A silver deposit solution comprising:
an acid selected from the group consisting of salicylic acid and salicylic acid derivatives;
a source of silver ions; and
a phosphate ester surfactant.
22 . The silver deposit solution of claim 21 further comprising a mineral acid.
23 . The silver deposit solution of claim 22 wherein said mineral acid is nitric acid.
24 . The silver deposit solution of claim 23 further comprising a chelator.
25 . The silver deposit solution of claim 24 wherein the chelator is selected from the group consisting of N-(2-hydroxyethyl)ethylenediaminetriacetic acid and its salts.
26 . The silver deposit solution of claim 21 wherein said acid is 3,5-dinitro salicylic acid.
27 . The silver deposit solution of claim 21 wherein said phosphate ester surfactant is a phosphate ester of tridecyl alcohol ethoxylate.
28 . The silver deposit solution of claim 21 wherein the source of silver ions is a silver salt.
29 . The silver deposit solution of claim 21 wherein the silver deposit solution is non-foaming.
30 . The silver deposit solution of claim 21 wherein the silver deposit solution is low foaming.
31 . A process of depositing silver onto a metal surface, comprising:
providing a metal surface; and
applying a silver deposit solution to the metal surface, the silver deposit solution comprising;
an acid selected from the group consisting of salicylic acid and salicylic acid derivatives;
a source of silver ions; and
a phosphate ester surfactant.
32 . The process of depositing silver onto a metal surface of claim 31 wherein the metal surface is copper.
33 . The process of depositing silver onto a metal surface of claim 31 wherein the metal surface is on a printed wiring board.
34 . The process of depositing silver onto a metal surface of claim 31 wherein the metal surface is positioned vertically.
35 . The process of depositing silver onto a metal surface of claim 31 wherein the silver deposit solution is sprayed on the metal surface.
36 . The process of depositing silver onto a metal surface of claim 31 wherein the silver deposit solution is non-foaming.
37 . The process of depositing silver onto a metal surface of claim 31 wherein the silver deposit solution is low foaming
38 . An aqueous silver deposit solution comprising
an acid;
a source of silver ions; and
an additional component
wherein said aqueous silver deposit solution forms less than 20 mL of foam when added to water in a graduated cylinder and agitated.