Flux, flux-cored solder using flux, flux-coated solder using flux and soldering method

Patent metadata

Field	Value
Publication number	US-11858072-B2
Application number	US-202117623668-A
Country	US
Kind code	B2
Filing date	Feb 1, 2021
Priority date	Mar 30, 2020
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A flux according to the present invention contains a rosin methyl ester in which the flux is a solid or solid-like flux at 25° C., and is used for an inside of a flux-cored solder or an exterior of a flux-coated solder.

First claim

The invention claimed is:

1. A flux comprising:
a rosin methyl ester,
an unesterified rosin and,
an activator which includes an organic halogen compound activator,
wherein a content of the rosin methyl ester is 0.5% to 20% by mass with respect to a total mass of the flux,
wherein a content of the unesterified rosin is 73% to 98.9% by mass with respect to the total mass of the flux,
wherein the flux is solid at 25° C. or is solid-like having a viscosity η 1 at 25° C. of 3,200 Pa·s or more when the viscosity is measured by the steps comprising:
sandwiching the flux between parallel flat plates of a rheometer and deforming by narrowing a space between the parallel flat plates while heating at 100° C.
thereby forming a thin sample of the flux having a thickness of 0.5 mm,
cooling the thin sample to 25° C.,
rotating the parallel flat plates of the rheometer at 6 Hz;
measuring the viscosity η 1 at 25° C. 5 minutes after rotating parallel flat plates; and

wherein the flux is used for an inside of a flux-cored solder or an exterior of a flux-coated solder.

2. The flux according to claim 1 ,
wherein the rosin methyl ester is one or more methyl ester products selected from a group consisting of a natural rosin, a hydrogenated rosin, a polymerized rosin, a disproportionated rosin, an acid-modified rosin, a hydrogenated polymerized rosin, and a hydrogenated acid-modified rosin.

3. The flux according to claim 1 ,
wherein the flux has a softening point of 28° C. to 100° C. in accordance with JIS K 5902-1969.

4. The flux according to claim 1 ,
wherein the rosin methyl ester is a liquid at 25° C.

5. The flux according to claim 1 , further comprising a solvent, wherein a content of the solvent is 13% by mass or less with respect to a total mass of the flux.

6. The flux according to claim 1 , is not a paste.

7. A method for using the flux according to claim 1 , comprising manufacturing a flux-cored solder or a flux-coated solder by including the flux.

8. The flux according to claim 1 ,
wherein the organic halogen compound activator includes trans-2,3-dibromo-2-butene-1,4-diol, 2,3-dibromo-1,4-butanediol, 2,3-dibromo-1-propanol, 2,3-dichloro-1-propanol, 1,1,2,2-tetrabromoethane, 2,2,2-tribromoethanol, pentabromoethane, carbon tetrabromide, 2,2-bis(bromomethyl)-1,3-propanediol, meso-2,3-Dibromo-succinic, chloroalkane, a chlorinated fatty acid ester, n-hexadecyltrimethylammonium bromide, triallyl isocyanurate hexabromide, 2,2-bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]propane, bis[3,5-dibromo-4-(2,3-dibromopropoxy)phenyl]sulfone, ethylenebispentabromobenzene, 2-chloromethyloxirane, HET acid, HET anhydride, or brominated bisphenol A epoxy resin.

9. The flux according to claim 1 , wherein the flux does not include any solvent.

10. The flux according to claim 1 , wherein the flux is solid at 25° C.

11. A flux-cored solder comprising,
a solder alloy, and
the flux according to claim 1 , filled into the solder alloy.

12. The flux-cored solder according to claim 11 , wherein the flux does not include any solvent.

13. A flux-coated solder comprising
a solder alloy having a predetermined shape, and
the flux according to claim 1 coated on an outer surface of the solder alloy.

14. The flux-coated solder according to claim 13 , wherein the flux does not include any solvent.

15. A soldering method comprising performing soldering with the flux according to claim 1 .

Assignees

• Senju Metal Industry Co

Inventors

• Kurasawa Yoko
• Iseki Hiroaki
• Nakajima Kenta

Classifications

• B23K35/3613 Primary

  Polymers, e.g. resins · CPC title

• B23K35/362 Primary

  Selection of compositions of fluxes (B23K35/365, B23K35/368 take precedence) · CPC title

• B23K35/365

  Selection of non-metallic compositions of coating materials either alone or conjoint with selection of soldering or welding materials · CPC title

• B23K35/368

  Selection of non-metallic compositions of core materials either alone or conjoint with selection of soldering or welding materials · CPC title

• B23K35/3612 Primary

  with organic compounds as principal constituents · CPC title