The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 03, 1992
Filed:
May. 29, 1990
Applicant:
Inventors:
Assignee:
Shimizu Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C25D / ; C25D / ;
U.S. Cl.
CPC ...
205254 ; 106-122 ; 106-125 ;
Abstract
The invention provides a bath for immersion plating a substance with a tin-lead alloy, which includes tin(II) ions, lead(II) ions, organic sulfo groups and thiourea or a mixture of thiourea and a thiourea derivative for a complexing agent. The organic sulfo groups allow insoluble thiourea complexes to be stably dissolved in the solution of the bath; thereby there is no need to retain the bath at a high temperature. Compared with conventional baths for immersion plating, the bath of the invention attains stable plating and a longer life of itself. Addition of the thiourea derivative prevents whiskers from being deposited and allows uniform and sufficiently smooth plating.