The patent is one that I am one of the authors on. It was granted in
1999. In 2003 (I believe) a lawsuit between the company owning this
patent (which I do not work for any longer) and another company
resulted a shotgun attack on the patent portfolio of my previous
employer. This patent was not part of the actual lawsuit, which was
settled in 2005. Unfortunately, once a reexamination is started it
cannot be stopped short of a determination of the validity of the
patent by the USPTO.
I was asked by my former employer to help them respond to the second
office action by the PTO, which was looking to disallow about 1/2 of
the claims of the patent. It turns out that the actual definitions of
these terms may have a bearing the validity of the claims.
The patent is not a metallurgy patent in itself but uses the terms in
some sections. The patent is associated with electronics packaging
techniques.
Regards
The narrow definition of a bronze is an alloy of copper and tin with
or without small proportions of other elements such as zinc and
phosphorus. A broader definition (by function) also includes certain
copper-base alloys containing less tin than other alloying elements,
such as manganese bronze (copper-zinc plus manganese, tin and iron)
and leaded tin bronze (copper-lead plus tin and sometimes zinc). By
analogy, other copper base alloys without tin are also called
(adjective) bronzes such as aluminum bronze (copper-aluminum), and
silicon bronze (copper-silicon). Even broader definitions include
trade names.
A loose definition is that brazing is the joining of metals through
the use of heat and a filler metal - one whose melting temperature is
above 840°F (450°C) but below the melting point of the two base metals
being joined.
See:
http://www.lucas-milhaupt.com/htmdocs/brazing_support/everything_about_brazing/what_brazing_about.html
A more precise definition clarifies the distinction between brazing,
soldering, and welding:
http://www.lucas-milhaupt.com/htmdocs/brazing_support/faqs.html#Whatisthedifferencebetweensolderingbrazingandwelding ?
Brazing - The AWS defines brazing as a group of joining processes that
produce coalescence of materials by heating them to the brazing
temperature and by using a filler metal (solder) having a liquidus
above 840°F (450°C), and below the solidus of the base metals.
Soldering - Soldering has the same definition as brazing except for
the fact that the filler metal used has a liquidus below 840°F (450°C)
and below the solidus of the base metals.
Welding - In welding, fusion takes place with melting of both the base
metal(s) and usually a filler metal.
(The liquidus the lowest temperature at which a metal or alloy is
completely liquid. The solidus is the highest temperature at which a
metal or alloy is completely solid. In between it is mush.)
If you want good formal definitions, then go to your local public
library or engineering library and look in the ASM Handbook (Older
versions were called the Metals Handbook). Any good library should
have the single volume Metals Handbook Desk Edition which has a
section called Glossary of Metallurgical and Metalworking Terms.
Pittsburgh Pete
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