OK, I didn't get much response to my "informal poll" (thanks Dewey and Werner!), so I'll ask one more specific question before I start getting grouchy (grin) If you attend Lead Free Reliability presentations by people like Werner Englemaier or Gary Ferrari (highly respected in our industry) they recommend a material like IPC-4101/126 or /129 If you go to websites like Merix (also highly respected) http://www.merix.com/RoHS+_+Lead+Free.aspx?id=4 they recommend something different (so don't say, "ask your fabricator") Does anyone have knowledge that would help clarify the discrepancy? Is the /126 /129 just SUPER reliable over /99 and /124? (ok, that was more than one question) we are auomotive, but I know I am going to be asked to justify the added expense sooner or later... maybe I'm just looking for a group hug. sheep mentality. baaa.... and no, I'm not a materials expert, but I MUST call out SOMETHING. and SOON! (I'm trying to wade through the materials info in the new Printed Circuits Handbook, but its still confusing. But hey, maybe I WILL be a materials expert by next week, huh?) onward thru the fog, Jbro On 10/29/07, Whittaker, Dewey (EHCOE) <[log in to unmask]> wrote: > > Yes and a few additional requirements. > Yes and /129 also. > It depends (cha-ching). > Yes. > Yes. > 1.5 mil avg. with 1.2 mil minimum. > > Dewey > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Jack Olson > Sent: Monday, October 29, 2007 10:28 AM > To: [log in to unmask] > Subject: [TN] Bare-Board Materials for Lead-Free Soldering > > I'm hoping to get an informal poll of fabricators and people who specify > bare board materials. > > There's been a lot of literature and presentations lately that > recommend numbers for better material performance under the higher > soldering > temperatures. > > IPC-4101/126 > Tg=170 or higher > Td=340 or higher > maximum expansion 3% > etc. > > I'm not questioning the wisdom of the numbers, I'd just like to know > whether > everyone (who is doing lead free soldering) is really USING these > numbers? > Or this material? Is there no wiggle room anymore? (EVERY example I see > now, > lists /126 material) > > I've also been advised to use a thicker minimum hole wall thickness than > before. Is that common now? >1mil? > > thanks, > Jack > > --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------