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:
May. 20, 1986
Filed:
Jun. 03, 1985
Applicant:
Inventors:
Vijay M Sajja, Fremont, CA (US);
Ranjan Mathew, San Jose, CA (US);
Jagdish Belane, Cupertino, CA (US);
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Primary Examiner:
Int. Cl.
CPC ...
C25D / ; C25D / ;
U.S. Cl.
CPC ...
204 15 ; 204 321 ;
Abstract
A method for solder plating metal leads in plastic semiconductor packages comprises cleaning the leads followed by electroplating tin or a tin/lead alloy onto the leads. The cleaning is effected with a non-corrosive solution which is either a carboxylic acid, a hydroxycarboxylic acid, or a combination of both. The electroplating solution is a sulfonic acid or citric acid based system, including suitable tin salts and/or lead salts. A sequestering agent may be used to inhibit the corrosive effect of the electroplating bath.