Dave, I had just gotten back from a run and it was hot and I just downed two Diet Pepsi's (unlike Doug I'm not a Dew-Man or a Diet Coke-Man like you) and couldn't resist poking a little fun. I sort of guessed you must have been talking about a military microwave product that used electrolytic silver and converted to immersion silver when it was available. However, the point you made as well as the others who responded to the immersion silver question certainly confirms immersion silver is a good choice. Regards, George George M. Wenger Andrew Corporation 40 Technology Drive, Warren, NJ 07059 (908) 546-4531 [log in to unmask] -----Original Message----- From: [log in to unmask] [mailto:[log in to unmask]] Sent: Thursday, August 28, 2003 3:44 PM To: [log in to unmask]; Wenger, George M. Cc: [log in to unmask] Subject: Re: [TN] Immersion Silver vs. White Tin Hi George! Ok, maybe I smudged the calendar a bit (I blame it on not enough Diet Coke for the day). We began producing the assembly in 1993 as an electrolytic silver finish (the assembly is an RF design) and switched to immersion silver in the 1994 timeframe - immersion silver was a very new creature in those days but we were pretty happy with its performance. The immersion silver finishes have gotten even better since the 1994-1997 timeframe when many of us were trying to understand them. I'll go get another Diet Coke - it will improve my math! Dave "Wenger, George M." To: [log in to unmask] <George.Wenger@AN cc: DREW.COM> Subject: Re: [TN] Immersion Silver vs. White Tin Sent by: TechNet <[log in to unmask]> 08/28/2003 02:33 PM Please respond to "TechNet E-Mail Forum."; Please respond to "Wenger, George M." Dave, Are you sure about the 10 years/ Could it be more like 6-7 years? The first knowlede I had about immersion silver wass from the SSTC Conbference at the NPL in Oct 1996. Anyway what's a couple of years, the result is the same immersion silver works. My old employer was in volume production of immersion silver assemblies since 1997 and immersion silver is the surface finish of choice in my new company. Regards, George George M. Wenger (908)-546-4531 Reliability Engineer RF Power Amplifier Group Andrew Corporation, 40 Technology Drive, Warren, NJ 07059 [log in to unmask] -----Original Message----- From: Dave Hillman [mailto:[log in to unmask]] Sent: Thursday, August 28, 2003 3:18 PM To: [log in to unmask] Subject: Re: [TN] Immersion Silver vs. White Tin Hi Jim! We have done a bunch of testing and have found that the immersion silver finish does not impact the solder joint reliability for a controlled soldering process. We published the BGA data at the IPC APEX 2000 meeting in Long Beach (the paper should be listed in the proceedings). We have also been producing an immersion silver assembly for 10 years for a military customer with no issues. Nothing solders like solder but immersion silver isn't too far behind. Dave Hillman Rockwell Collins [log in to unmask] "Marsico, James" <James.Marsico@DP To: [log in to unmask] .AIL.COM> cc: Sent by: TechNet Subject: Re: [TN] Immersion Silver vs. White Tin <[log in to unmask]> 08/28/2003 11:59 AM Please respond to "TechNet E-Mail Forum."; Please respond to "Marsico, James" Just out of curiosity, does the immersion silver effect long term reliability of tin-lead solder joints? Jim Marsico Senior Engineer Production Engineering EDO Electronics Systems Group [log in to unmask] <mailto:[log in to unmask]> 631-595-5879 -----Original Message----- From: Dave Chapman [SMTP:[log in to unmask]] Sent: Thursday, August 28, 2003 12:53 PM To: [log in to unmask] Subject: Re: [TN] Immersion Silver vs. White Tin Agreed, Immersion Silver was a drop in replacement both at reflow and wave. Silver was lower cost or same as HASL. Only caution, the joints do look different than HASL boards so education rather than rejection is the word of the day. As with all alternate finish boards handling is important, hands off the board, slip sheets needed on only the top and bottom boards since the finish is actually below the surface of the solder mask so no big risk of scratching) in vacuum sealed bags, remove from packaging just before processing, don't let sit on the shelf unless fully processed, don't wait 3-4 weeks to run through the wave after SMT because you may see tarnish, although solderability is still good, statistically the sooner processed the better. White Tin we had to go to higher temp profile and watch every step. Congratulations on going to Lead Free PCB's Dave Chapman -----Original Message----- From: Bill DeCray [mailto:[log in to unmask]] Sent: Thursday, August 28, 2003 11:34 AM To: [log in to unmask] Subject: Re: [TN] Immersion Silver vs. White Tin Immersion silver would be the best choice Highest Regards William W. DeCray III Sales Engineering Manager Waytec Electronics Corp. Phone: (434) 237-6391 Ext 115 Fax: (434) 237-1324 Cell: (434) 851-6115 E-mail [log in to unmask] Website www.waytec.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Thursday, August 28, 2003 11:31 AM To: [log in to unmask] Subject: [TN] Immersion Silver vs. White Tin Hi All! Got a customer that's calling out on the fab drawing, either Immersion Silver or White Tin for a board finish. Me, not having great deal of experience with either one (yet), am wondering if I had to choose, which one would I choose? Have any of you worked with both, and have a preference of one over the other? Why? As always, thanks in advance! -Steve Gregory- ------------------------------------------------------------------------------------------------ This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. 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