Sorry, I forgot to answer part of the question.
A small amount of antimony like the 0.25 mass% which we tested, does not change the melting point to a substantial extent. It stays 217 deg.C like the SnAgCu pure eutectic alloy.
Regards, Erik
----------------------------------------------------------------------------------------------------------------------------------
Erik E. de Kluizenaar
Philips CFT - Electronic Packaging & Joining (EP&J)
Building SAQ-p, p/o box 218, 5600 MD Eindhoven - The Netherlands
Tel/Fax: (+31 40 27) 36679/36815; E:mail [log in to unmask]
PHILIPS worldwide homepage: http://www.philips.com
Internal PHILIPS only: http://pww.cft.philips.com/cfteurope/electronics/elpajo/index.htm
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---------------------- Forwarded by E.E. de Kluizenaar/EHV/CFT/PHILIPS on 2000/10/04 02:16 PM ---------------------------
E.E. de Kluizenaar
2000/10/04 09:54 AM
To: [log in to unmask]@SMTP
[log in to unmask]@SMTP
cc:
Subject: Re: [LF] Alloy question
Classification: Unclassified
Dear Kirk, dear all,
In the BRITE/EURAM project IDEALS we have tested SnAg3.8Cu0.7Sb0.25 as a wave soldering alloy. Unfortunately, the resources and time schedule did not allow us to cross check this alloy against SnAg3.8Cu0.7. You have to realise that each alloy requires
about 800 kg of solder and the solder pot should be rinsed in between (with e.g. pure tin) to temove unwanted residues from previously applied alloys. Further, the extended reliability testing would double, which requires large climate chamber, a lot of
microsectioning etceteras. Simply to much to grasp. This was very unfortunate, of course, but we had to make an "educated guess" because of that.
Why then antimony addition? Well, Mo Biglari, our partner from Alpha-Fry Technology, found out that it improved the wetting characteristics slightly. Further, it gave some grain refining, which probably improves the fatigue life of the soldered joints.
That's why!
For further information, I refer to our extended articles and lectures in the conferences, both on September 12th, in Berlin (Electronics Goes Green; proceedings p.73-83; I presented the lecture) and Miami (IPCWorks 2000; Mo presented the lecture);
authors M. Biglari et. al. in both cases.
With best regards,
Erik
----------------------------------------------------------------------------------------------------------------------------------
Erik E. de Kluizenaar
Philips CFT - Electronic Packaging & Joining (EP&J)
Building SAQ-p, p/o box 218, 5600 MD Eindhoven - The Netherlands
Tel/Fax: (+31 40 27) 36679/36815; E:mail [log in to unmask]
PHILIPS worldwide homepage: http://www.philips.com
Internal PHILIPS only: http://pww.cft.philips.com/cfteurope/electronics/elpajo/index.htm
-----------------------------------------------------------------------------------------------------------------------------------
[log in to unmask]@[log in to unmask] on 2000/10/04 12:04:02 AM
Please respond to [log in to unmask]@SMTP
Sent by: [log in to unmask]
To: [log in to unmask]@SMTP
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Subject: [LF] Alloy question
Classification:
What does anyone know about the Sn/Ag/Cu/Sb alloy? From what I read,
compared to Sn/Ag/Cu, it has a lower melting point, lower cost, and yet
very similar physical properties. I know there is a toxicity concern,
but, once again, according to what I read, a level of .5% is allowable.
Perhaps it will be phased out eventually much like lead is now. Any
experiences or thoughts on this?
Thanks in advance for your help,
Kirk
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