Method for regeneration of electroless nickel plating solution

Patent · Tue Dec 31 23:00:00 EST 1996

OSTI ID:870856

Eisenmann, Erhard T ^[1]

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1. 5423 Vista Sandia, NE., Albuquerque, NM 87111

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 hypophosphorous 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.

• Research Organization: AT & T CORP
• DOE Contract Number: AC04-76DP00789
• Assignee: Eisenmann, Erhard T. (5423 Vista Sandia, NE., Albuquerque, NM 87111)
• Patent Number(s): US 5609767
• OSTI ID: 870856
• Country of Publication: United States
• Language: English

Related Subjects

/210/106/
acetate
acetic
acetic acid
acid
added
addition
adjusted
avoiding
bath
bath solution
buffer
capable
cations
chelating
combined
concentrated
concentration
ease
electroless
electroless nickel
eluate
elution
employing
employs
evaporation
exchange
form
generation process
hazardous
hazardous waste
hypophosphite
hypophosphorous
method
nickel
nickel plating
nickel salt
operation
perpetual
phosphites
plating
plating bath
plating solution
precipitation
process
process employs
production
provided
reduced
regeneration
regeneration process
remove
removed
replenishing
replenishment
result
resulting
resulting solution
salt
solution
spent
stabilizer
starter
treated
volume
waste