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. 05, 1991
Filed:
Dec. 27, 1990
Thomas L Ellison, San Jose, CA (US);
David A Roberts, Carlsbad, CA (US);
John C Ivankovits, Northampton, PA (US);
John A Norman, Whitehall, PA (US);
Air Products and Chemicals, Inc., Allentown, PA (US);
Abstract
A residue-free fluxing process wherein the active fluxing agent comprises a .beta.-diketone or .beta.-ketoimine ligand. Such ligands react with surface metal oxides on workpieces to be soldered to form volatile metal-ligand complexes as reaction products which are sublimed from the surface leaving essentially no residue on the workpieces. The fluxing agents can be utilized in gas-phase processes wherein the workpieces are contacted with an effective amount of one or more ligands which are dispersed in a carrier gas or solvent or by incorporating the ligands into an alloy-vehicle mixture for use as conventional creams or pastes. The invention eliminates the need for post-reflow cleaning using solvents since no flux residue remains on the workpieces to be soldered following volitilization of the metal-ligand complex.