Method of treating gold or gold alloy with a surface treatment solution comprising a disulfide compound

Patent metadata

Field	Value
Publication number	US-9790606-B2
Application number	US-201414556154-A
Country	US
Kind code	B2
Filing date	Nov 30, 2014
Priority date	Nov 29, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

To provide a surface treatment solution and treatment method for gold or gold alloy plating that effectively suppresses corrosion of underlying metal or substrate metal from pinholes that develop on the gold or gold alloy plating film.
[Solution] A surface treatment solution containing a disulfide compound is brought into contact with a gold or gold alloy plating film. A compound represented by the following formula (2) is preferred as the disulfide compound.

X 1 O 3 S—R 3 —S—S—R 4 —SO 3 X 2   (2)

in the formula, R 3 and R 4 independently represent a linear or branched alkylene group having from 1 to 10 carbon atoms, cyclic alkylene group having from 3 to 10 carbon atoms, or phenylene group, R 3 and R 4 independently may be substituted by one or more substituents selected from an alkyl group, halogen atom, hydroxyl group, or alkoxy group, and X 1 and X 2 represent monovalent cations.

First claim

What is claimed is:

1. A surface treatment method for gold or gold alloy plating film formed on nickel or nickel alloy underlayer, wherein the surface treatment method comprises a step for bringing the gold or gold alloy plating film formed on the nickel or nickel alloy underlayer into contact with a surface treatment solution consisting of water, at least one type of disulfide compound, wherein the disulfide compound is represented by the following formula (2):
X 1 O 3 S—R 3 —S—S—R 4 —SO 3 X 2   (2)

wherein R 3 and R 4 independently represent a linear or branched alkylene group having from 1 to 6 carbon atoms, or phenylene group, R 3 and R 4 independently may be substituted by one or more substituents selected from halogen atom, hydroxyl group, or alkoxy group, and X l and X 2 represent monovalent cations,
a nonionic surfactant and a pH adjuster chosen from hydrochloric acid, nitric acid, sulfuric acid, citric acid, potassium hydroxide, sodium hydroxide or carbonates, wherein a pH of the surface treatment solution is 3 or higher.

2. The surface treatment method of claim 1 , wherein the nonionic surfactant is chosen from polyethylene glycol, polyoxyalkylene monobutyl ether, polyoxypropylene glycol or ethylene glycol-propylene glycol block polymers.

Assignees

• Rohm & Haas Elect Mat
• Rohm And Haas Electronics Mat Llc

Inventors

• Yomogida Koichi

Classifications

• C23F11/10

  using organic inhibitors · CPC title

• C25D3/48 Primary

  of gold · CPC title

• C23C22/60

  using alkaline aqueous solutions with pH greater than 8 · CPC title

• C25D5/48

  After-treatment of electroplated surfaces · CPC title

• C23C22/05 Primary

  using aqueous solutions · CPC title