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US 5,064,480 AGranted
Water washable soldering paste
AssigneeQuantum Materials, Inc.
InventorsStephen M. Dershem, Richard R. Weaver
Life of this patent
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Abstract
Improved soldering paste for surface mounting of electronic components comprises a novel fluxing agent selected from formylated polyhydric compounds. The paste enables circuit boards to be washed with water to remove flux residues.
Claims11
A soldering paste comprising:
- 80to 95 weight percent solder alloy melting at or below 250.degree. C.;
- and
- 5 to 20 weight percent soldering flux comprising 0 to 95 weight percent organic solvent and 5 to 100 weight percent of a metal oxide removing substance selected from the group consisting of formylated polyhydric compounds and mixtures thereof, said polyhydric compounds selected from polyhydroxy aliphatic compounds and polyhydroxy resins.
A soldering paste comprising:
- 80 to 95 weight percent solder alloy melting at or below 250.degree. C.;
- 5 to 20 weight percent soldering flux comprising:
- 0 to 95 weight percent 2,2,4-trimethyl-1,3-propanediol monoisobutyrate;
- 5 to 100 weight percent formylated tris(hydroxymethyl)aminomethane;
- up to 40 weight percent N,N,N',N'-tetrakis(2-hydroxypropyl(ethylenediamine;
- up to 10 weight percent hydroxypropyl cellulose;
- and
- up to 10 weight percent hydrogenated castor oil.
5 more elements
Dependencies are inferred from the claim text.