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:
Feb. 11, 1992
Filed:
Nov. 05, 1990
Applicant:
Inventors:
Cynthia M Melton, Bolingbrook, IL (US);
Carl J Raleigh, Cary, IL (US);
Steven Scheifers, Hoffman Estates, IL (US);
William Beckenbaugh, Barrington, IL (US);
Assignee:
Motorola Inc., Schaumburg, IL (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
228208 ; 228 563 ; 428570 ; 428643 ; 428670 ;
Abstract
A body formed of a lead-tin solder alloy is pretreated to deposit palladium thereon prior to soldering to a metallic substrate. It is found that the palladium deposit enhances wetting of the substrate by the solder liquid during reflow and thereby, upon cooling, produces a strong metallurgical bond. In a preferred embodiment, lead-tin solder balls are pretreated by applying tin-palladium colloidal particles and dissociating the particles to form a discontinuous metallic palladium deposit.