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Title: Method for regeneration of electroless nickel plating solution

An electroless nickel(EN)/hypophosphite plating bath is provided employing acetic acid/acetate as a buffer and which is, as a result, capable of perpetual regeneration while avoiding the production of hazardous waste. A regeneration process is provided to process the spent EN plating bath solution. A concentrated starter and replenishment solution is provided for ease of operation of the plating bath. The regeneration process employs a chelating ion exchange system to remove nickel cations from spent EN plating solution. Phosphites are then removed from the solution by precipitation. The nickel cations are removed from the ion exchange system by elution with hypophosphorus acid and the nickel concentration of the eluate adjusted by addition of nickel salt. The treated solution and adjusted eluate are combined, stabilizer added, and the volume of resulting solution reduced by evaporation to form the bath starter and replenishing solution. 1 fig.
Inventors:
Issue Date:
OSTI Identifier:
445702
Assignee:
SNL; SCA: 320305; 320302; PA: EDB-97:040791; SN: 97001749870
Patent Number(s):
US 5,609,767/A/
Application Number:
PAN: 8-241,234
Contract Number:
AC04-76DP00789
Resource Relation:
Other Information: PBD: 11 Mar 1997
Research Org:
AT&T Corporation
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; PROCESS SOLUTIONS; METAL INDUSTRY; REGENERATION; RECYCLING; NICKEL; PLATING; CHELATING AGENTS; ION EXCHANGE; PRECIPITATION