Steve, I am not going to put words in Vahid's or Ron's mouth, but I would expect that in answer to your first question it would either be really, really hard, if not impossible. And let's face it, it was a good marketing move, whether it was initially intentional or not. "...is lead-free solder the green "environmentally responsible" success that was purported and mandated to all of us?" The answer to that is of course NO. I think it is an unmitigated disaster where we have traded one environmental issue for several we know even less about - more energy use, more tin and silver mining, more silver potentially killing micro-organisms, tin whiskers, drop failures, premature aging of components because of manufacturing heat stress, more brittle board materials and the list can be lengthened by others. Some of these are straight out enviro in nature the others are indirectly because they lead to more scrap. Bev -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Saturday, July 23, 2011 10:37 PM To: [log in to unmask] Subject: Re: [TN] Lead Free solder has performed well... Ron, You know as well as I do, that the reason we were all told that we HAD to to convert to lead-free, was because it was going to be the "environmentally responsible" thing to do. It wasn't because we wouldn't be able manufacture iPhones and the like because of the higher density and tighter lead pitches. So I find the positive spin put out about lead-free solder after the "cows have been let out of the barn" so to speak, interesting. Don't you think that problems with solder shorts could be addressed by optimizing board and pad layout, stencil specifications, printing processes, and reflow parameters? Wouldn't have that been the answer rather than switching to another solder alloy that has questionable environmental benefits over tin/lead solder? So, the question still remains (and many are still asking); is lead-free solder the green "environmentally responsible" success that was purported and mandated to all of us? Steve -----Original Message----- From: Ron Lasky Sent: Saturday, July 23, 2011 12:15 PM To: [log in to unmask] Subject: Re: [TN] Lead Free solder has performed well... Folks, Pete is correct. I never said lead-free implementation was a grand success. These were Rob's words in his blog post (http://www.designnews.com/author.asp?section_id=1389&doc_id=231199&f_src=de signnews_gnews). I have said repeatedly that adequate lead-free reliability has been demonstrated for consumer products like mobile phones, PCs, portable electronics with service lives less than 5 years. This level of reliability has been demonstrated in numerous studies and more importantly with field data. Vahid Goudarzi, of Motorola, stated that field reliability of lead-free assembled mobile phones has been equal or better than leaded assembly units. His data go back to 2001 (not 2006, Motorola started early for reasons discussed below). The reason Motorola shipped early with lead-free products is due to the fact that lead-free solder does not spread as well. Because of this poorer spreading, Motorola was able to decrease lead spacings without getting shorts, thus increasing the amount of electrical function in a smaller space. Since increased function in a smaller space is the defining attribute of portable electronics, the importance of this lead-free advantage cannot be overstated. Admittedly, lead-free's poorer wetting is a challenge in other regards, especially hole fill in wave soldering, but the Motorola Droid X2 could not be assembled with leaded solder, there would be too many shorts. Since the packaging density of the iPhone and similar devices is on a par with the Droid X2, I suspect this statement is true for most mobile products. I have also repeatedly stated that lead-free reliability for long term service, mission critical devices has not been demonstrated. As a result, these types of devices should not consider lead-free solder at this date. I regularly discuss these topics in my blog (http://blogs.indium.com/blog/an-interview-with-the-professor). The most recent post shows a striking photo of leaded solders too good spreading for portable electronics. Cheers, Ron --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. 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