Steve Gregory said:

>We just got our solder analysis back (it's from a lab that everyone uses)
>for our wave solder pots, and we have one wave solder pot that's low in Tin...

(snipping for brevity)

>...Looking at the tin content on the other
>two pots, they're just barely above the limit which is 62.4%-63.6%...is my bar
>solder vendor starting to get tight with the Tin? Any light that anybody can
>shed on this would be 'preciated...

As the solder oxidizes to form dross, tin oxide forms more readily,
depleting the pot. In my experience, a solder pot which does not see much
production volume tends to lose tin. If you are putting in numerous new
bars daily, it will stay very near your new solder content, otherwise it
will tend to deplete Sn and show higher contamination. My guess is the "pot
2" machine is more lightly used than the other two.

I have also heard of tin being somewhat low in new bars, as it is much more
expensive. They probably stay on the low side of 63% in many cases.

There was an interesting thread on TechNet in December (but then the past
4-5 weeks have been a fog for me) relating to some metallurgists saying the
true eutectic for binary tin-lead is actually more like 61% - even though
most sources say 63% Sn.

I suggest you throw in a few pure tin bars if that's what your own
procedures stipulate for tin operating range, otherwise let it alone. Don't
lose any sleep over the metal alloy operation, though.


regards,


Jerry Cupples
Interphase Corporation
Dallas, TX USA
http://www.iphase.com


***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to:           *
* [log in to unmask] with <subject: unsubscribe> and no text.        *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************