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.

Date of Patent:
Nov. 12, 1991

Filed:

May. 17, 1990
Applicant:
Inventors:

James L Davis, Tamarac, FL (US);

Robert W Pennisi, Boca Raton, FL (US);

Fadia Nounou, Plantation, FL (US);

Bobby D Landreth, Davie, FL (US);

Assignee:

Motorola, Inc., Schaumburg, IL (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
148 23 ; 148 24 ; 148 25 ;
Abstract

Fluxing compositions are described containing as fluxing agents compounds of the formula: ##STR1## where R is an electron withdrawing group. In one embodiment, R is selected from the group consisting of fluorine, chlorine, bromine, iodine, sulfur, hydroxyl, nitrile, and benzyl. The compound cleans oxides from the printed circuit boards (PCBs) under assembly and then volatilize with little or no need for a cleaning step, or cleaning only with water or formic acid. Very little or no undesired residue remains. Such acid fluxing agents can be used mixed with typical solder formulations, such as lead/tin solder pastes, or applied topically to solders, such as solder balls; both techniques permit the assembly of PCBs more easily with high quality bonds, and with little or no residue. Malic acid is a preferred organic acid fluxing agent.


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