Hi Richard,
Yes I am referring to the intermettallics. Thanks for the clarification.
I found an excellent piece in the archives by Kieth Sweatman that answered
most of my concerns, but one.
http://listserv.ipc.org/scripts/wa.exe?A2=ind0211&L=leadfree&P=R13462&I=-3
Because this intermettallic is less dense than the LF solder it will sink,
it remains inside the pot consequently can influence the solder dynamics.
Previously this could be removed as part of the dross removal.
Is there a way to remove this assuming we failed to manage the Cu content
below saturation?
Rgds
Dennis.
-----Original Message-----
From: Richard Kraszewski [mailto:[log in to unmask]]
Sent: Wednesday, 6 July 2005 10:22 PM
To: TechNet E-Mail Forum; Dennis Bang
Subject: RE: [TN] LF Selective and Wave Soldering
Regarding the LF dross.
I suspect that you are referring to intermetallics rather than dross.
The source that told you otherwise is correct. Copper-tin intermetallics
will now sink rather than rise to the top. This is due to the lower
density of Pb-free alloys.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Dennis Bang
Sent: Tuesday, July 05, 2005 9:50 PM
To: [log in to unmask]
Subject: [TN] LF Selective and Wave Soldering
Hi all,
Just like to know whether anyone has done Lead Free Selective Soldering.
Did you have any issues or difficulties?
Secondly on LF dross. I read somewhere that the density of LF dross is
greater than SnPb and the LF alloy, it will sink instead of float.
However a
source who are using LF solders have told me otherwise.
Is this a big issue, if an issue? How would you handle this?
Regards
Dennis Bang
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