Patent · US Expired

Aqueous immersion plating bath and method for plating

US6063172A · kind A · utility

30Cited by
10References
34Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 13, 1998
Grant dateMay 16, 2000
Priority date
Expiry dateOct 13, 2018

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/12535
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

It has now been found that one or more metals selected from the group consisting of tin, lead, bismuth, indium, gallium and germanium may be deposited onto a metal surface utilizing an aqueous electroless plating bath which comprises PA1 (A) at least one bath-soluble metal salt selected from the group consisting of stannous salts, lead salts, bismuth salts, indium salts, gallium salts, and germanium salts; PA1 (B) at least one complexing agent selected from the group consisting of thiourea compounds and imidazole thiones, and PA1 (C) at least one amidine. Preferably, the aqueous plating baths also contain at least one acid, and the baths optionally may contain one or more surfactants. The incorporation of the amidine into the plating baths results in a solution exhibiting desirable plating characteristics and increased copper holding power.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.