Pardon me, I should have said INCREASE in signal loss. When I think negative Db, I tend to use the wrong descriptor.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
Sent: Monday, January 28, 2013 3:34 PM
To: [log in to unmask]
Subject: Re: [TN] High speed signals and lead free solder
I have not heard of any decrease in signal loss above 1 Ghz due to the solder being 99% tin as opposed to SN63.
The difference in conductivity is so minute so as not to change the skin effect (Hall effect) by any significant amount, to my knowledge.
However, some folks have switched PWB finishes from Sn63 HASL to ENIG or IAg to make the PWB compliant, and use of ENIG has been proven to contribute to a much more lossy circuit due to the nickel plating, everything else being the same. IAg, on the other hand, will actually improve the performance of high-RF circuitry in most cases.
So, to summarize, the change in PWB finishes can cause degraded performance, but not solely the change from Sn63 to Sn99, so to speak.
At least not as far as I am aware. But someone may correct me otherwise.
The other aspect of this is that lead-free alloys are rougher due to the lack of lead, and this could cause some small amount of de-attenuation, but I doubt that it is very significant.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of John Burke
Sent: Monday, January 28, 2013 2:41 PM
To: [log in to unmask]
Subject: [TN] High speed signals and lead free solder
Anyone have any data to support degraded performance on high speed boards in changing from leaded to lead free solders??
John
John Burke
General Manager/COO
Zollner Electronics Inc
Plant Milpitas
575 Cottonwood Drive
Milpitas, CA 95035
Phone: + 1 408 434 5442
Fax: + 1 408 434 5401
Mobile: + 1 408 628 2433
E-mail: [log in to unmask]
Internet: www.zollner-electronics.com
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