Silver plating in electronics manufacture
AssigneeEnthone Inc.
InventorsYung-Herng Yau, Thomas B. Richardson, Joseph A. Abys, Karl F. Wengenroth, Anthony Fiore, Chen Xu, Chonglun Fan, John Fudala
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Abstract
Compositions and methods for silver plating onto metal surfaces such as PWBs in electronics manufacture to produce a silver plating which is greater than 80 atomic % silver, tarnish resistant, and has good solderability.
Claims20
A plating composition for Ag plating a metal surface, the composition comprising a source of Ag ions, water, and a modulating agent comprising an alkylene polyamine polyacetic acid compound, wherein the composition has a pH between 1 and about 3 and an ionic content such that the composition has a room temperature conductivity below about 25 mS/cm.
A composition for Ag plating a metal surface comprising:
- a) a source of Ag ions;
- b) an amino acid inhibitor of Ag deposition which functions at a pH between about 4 and about 5 to slow Ag deposition rate;
- c) water;
- and
- d) a hydantoin derivative, wherein the composition has a pH between about 4 and about 5 and an ionic content such that the composition has a room temperature conductivity below about 25 mS/cm.
A composition for Ag plating a metal surface comprising:
- a) a source of Ag ions;
- b) an amino acid inhibitor of Ag deposition which functions at a pH between about 4 and about 5 to slow Ag deposition rate;
- and
- c) water, wherein the composition has a pH between about 4 and about 5 and an ionic content such that the composition has a room temperature conductivity below about 25 mS/cm and wherein the concentration of the amino acid inhibitor of Ag deposition is between about 20 and about 40 g/L.
Dependencies are inferred from the claim text.