I was referring primarily to Pb-free solders, but from what I know and from what we've done, the same applies to Pb-Sn- based ones. Regards Vladimir Sent from my BlackBerry 10 smartphone on the Rogers network. Original Message From: Mike Fenner Sent: Tuesday, August 11, 2015 10:05 To: [log in to unmask] Reply To: [log in to unmask] Subject: Re: [TN] immersion silver Hmm Wouldn't it be as well to remember those discussions were about Sn/Pb systems not Pb free? This was in the days when "solder" was assumed to mean Sn/Pb. The effects of silver in high tin lead free alloys is rather different I was never quite sure the observations fitted well with Sn62 which at one time was around 50% of Sn/Pb pastes with not a lot of evidence for either Sn62 or Sn63 alloy. Or rather there was a lot of evidence for one alloy or the other depending on what the reporter's company was actually using. I assumed the Ag "contamination" problems reported from the Ag finish were due to non uniform dispersal into the Solder in the specific case being investigated. I never met these problems more generally. Mike -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev Sent: Tuesday, August 11, 2015 2:15 PM To: [log in to unmask] Subject: Re: [TN] immersion silver Thank you Dave :-). I also had a long discussion with Warner about that case he always referred to but had never seen any specifics. Do you have anything to shear just to feed my curiosity? Thank you Vladimir Sent from my BlackBerry 10 smartphone on the Rogers network. From: David Hillman Sent: Tuesday, August 11, 2015 08:28 To: TechNet E-Mail Forum; Vladimir Igoshev Subject: Re: [TN] immersion silver Hi team - well, as usual the truth actually lies in the middle of the technical discussion. Supporting Vlad's point, solder is fairly robust to silver in terms of degrading integrity influences so in most of our soldering situations its not an issue. Supporting Werner's point, he did have a specific case where silver embrittlement of the solder joint was the root cause of a series of solder joint failures. Werner and I had long discussions on that case as it was very interesting despite being somewhat of an odd case. So the final answer is silver can be an issue but it takes some specific metallurgical conditions. The immersion silver surface finished used today on printed circuit boards will not contribute to the degradation of solder joint integrity. Dave On Tue, Aug 11, 2015 at 7:02 AM, Vladimir Igoshev <[log in to unmask]> wrote: Hi Guy, With all due respect to Warner memory, silver IS NOT like gold and DOES NOT cause embrittlement. Therefore, from the reliability point of view it wouldn't matter what thickness of IAg was on a board, as long as we ONLY talking about the amount of Ag which would and up in the joints after re-flow. Regards, Vladimir Sent from my BlackBerry 10 smartphone on the Rogers network. Original Message From: Guy Ramsey Sent: Tuesday, August 11, 2015 07:37 To: [log in to unmask] Reply To: [log in to unmask] Subject: Re: [TN] immersion silver If Werner were alive he would be reminding us that silver, like gold, is a contaminate in tin solder. Early finishes, prior to 2005 or so, weren't good for multiple reflows. Some presumed it was too thin. I believe the problem was the durability of the organic additives that retard oxidation of the silver. Not perfect, but it is my preferred surface finish, but not too thick. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Kelly Sent: Monday, August 10, 2015 3:47 PM To: [log in to unmask] Subject: [TN] immersion silver Hi All, Why would someone choose thick immersion silver over thin? Are these different chemistries? Regards Steve Kelly Phone(O) (416) 750-8433 Phone (C) (416) 577-8433 If the recipient to whom this e-mail is sent has an NDA with PFC Flexible Circuits Limited this e-mail is considered confidential and is subject to any NDA agreements between the respective parties. See PFC on "How its' Made" in Canada on July 7th at 8 p.m. on the Discovery Channel ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. 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