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:
Aug. 05, 1986
Filed:
May. 20, 1985
William O Rogers, Tempe, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
Nickel layers used in electronic devices are frequently plated in solutions containing phosphorus. Residual phosphorus trapped in the plated nickel layer reduces solderability with respect to Pb-Sn solders. Voids are frequently found in the soldered joints. Solderability of such phosphorus containing nickel layers is enhanced and the number of voids is much reduced by heating the nickel surface first in an oxidizing atmosphere and then in a reducing atmosphere prior to soldering. The oxidation temperature should exceed 347.degree. C. in order to oxidize the residual phosphorus and drive off the volatile phosphorus oxides. Hydrocarbons and volatile sulfides are also removed. The reducing step removes the non-volatile nickel oxides, leaving a clean surface for soldering which is substantially free of nickel oxide, phosphorus and phosphorus oxides, sulfides, and organics.