Boric acid free flux

Patent metadata

Field	Value
Publication number	US-9700964-B2
Application number	US-201414211125-A
Country	US
Kind code	B2
Filing date	Mar 14, 2014
Priority date	Mar 15, 2013
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

The invention described herein pertains generally to boric acid free flux composition in which boric acid and/or borax is substituted with a molar equivalent amount of potassium tetraborate tetrahydrate. In some embodiments, a phthalocyanine pigment is used to effect a color change at activation temperature.

First claim

What is claimed is:

1. A boric acid free powder flux composition which comprises:

potassium tetraborate (K 2 B 4 O 7 •4H 2 O);

potassium fluorosilicate (K 2 SiF 6 ); and

potassium fluoroborate (KBF 4 ).

2. The boric acid free powder flux composition of claim 1 which further comprises:
boron.

3. The boric acid free powder flux composition of claim 2 which comprises approximately by weight percent, said composition added in an amount totaling 100%:

potassium tetraborate tetrahydrate (K 2 B 4 O 7 •4H 2 O)
44-54%;

potassium fluorosilicate (K 2 SiF 6 )
1-3%;

potassium fluoroborate (KBF 4 )
      44-54%; and

boron
0.1-2%.  

4. The boric acid free powder flux composition of claim 1 which further comprises:
a phthalocyanine pigment.

5. The boric acid free powder flux composition of claim 4 wherein
said phthalocyanine pigment changes from colored to colorless at a temperature of approximately 500-600° C.

6. The boric acid free powder flux composition of claim 4 which comprises approximately by weight percent, said composition added in an amount totaling 100%:

potassium tetraborate tetrahydrate (K 2 B 4 O 7 •4H 2 O)
44-54%;

potassium fluorosilicate (K 2 SiF 6 )
1-3%;

potassium fluoroborate (KBF 4 )
      44-54%; and

pigment (phthalocyanine)
0.1-2%.  

7. The boric acid free powder flux composition of claim 1 which further comprises:
boron; and
a phthalocyanine pigment.

8. The boric acid free powder flux composition of claim 7 which comprises approximately by weight percent, said composition added in an amount totaling 100%:

potassium tetraborate tetrahydrate (K 2 B 4 O 7 ·4H 2 O)
  44-54%;

potassium fluorosilicate (K 2 SiF 6 )
  1-3%;

potassium fluoroborate (KBF 4 )
  44-54%;

pigment (phthalocyanine)
0.1-2%;

and

boron
0.1-2%.

Assignees

• Lincoln Global Inc

Inventors

• Howard Robert A

Classifications

• B23K35/025

  Pastes, creams or slurries · CPC title

• B23K35/0244

  Powders, particles or spheres; Preforms made therefrom · CPC title

• B23K35/3613

  Polymers, e.g. resins · CPC title

• B23K35/362 Primary

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

• B23K35/00

  Rods, electrodes, materials, or media, for use in soldering, welding, or cutting · CPC title