On Thu, 02 Mar 2006 14:12:02 -0500, Leon Fisk
wrote:

On Thu, 2 Mar 2006 09:03:04 -0600, "Robert Swinney"
wrote:

It probably flows around 500 - 600 degrees. The "coolest" flowing
silver-bearing solder I am familiar with is 96% Tin, 4% Silver. It flows at
around 430 degrees F. Harris Stay Bright is one commercial version. Radio
shack has a silver-bearing solder coiled up in a tiny tube (at an outrageous
per-lb price), also of 96 - 4 formulation. Silver-bearing solders are best
fluxed with killed hydrochloric acid in paste or liquid form; such as Harris
Stay Clean. 96-4 has tensile strength of around 14,000 lbs, which should be
enough for a die filer. The low temps of 96 - 4 make it an attractive
choice when warping is a concern.

Bob Swinney

I don't want to get into a ****ing contest here, but I can't
find where this has a true tensile strength of around 14,000
lbs.

This Matweb link shows it as having 4640 psi (they don't
list the tensile for 96Sn/4Ag):

http://www.matweb.com/search/Specifi...bassnum=MLSS94

Other references I have show the various versions
(~95Sn/~5Ag) in the same area. Harris's web site has
"Tensile Strength (Cu to Cu) 14,000 psi" listed, but I read
this as meaning: soldering copper-to-copper. Grant won't be
soldering Cu-to-Cu in this application.

Here is an interesting chart I found a while back:

http://www.indium.com/products/alloy...loy_number.pdf

from this page:

http://www.indium.com/products/alloychart.php

I don't know, maybe I'm missing something here. That's why
I'm curious/asking the question...

There can be and usually is a difference between joint strength and
bulk properties of the solder itself. A good joint is usually
stronger than the solder with which it was made. This is because the
process of soldering involves some dissolution of the base metals
(like sugar melts in water) to form an intermediate alloy. The
matweb cite lists the properties of the solder itself, while Harris is
citing the strength of test joints.