Hi Werner, If class 1 is accepting 50% filling of through holes with solder and class 3 is accepting full PTH, I hope you agree that the solder joints strength are not the same? What I wanted to clarify, is that with lead free process, beside the known failures such whiskers, lifted pads etc., the DOA / short terms failures are mostly bad solder joints (SMT and through holes) happened because the small process window (PCB and components finish type / i.e short storage / shelf life and hi peak temperature). I have seen lot of reliability tests evaluation of Lead free including life cycles, talking about the difference between the alloys. I didn't see lot of tests evaluation dealing about the bad solder joints / low yield happened because the small process window. Best Regards Reuven ROKAH e mail: [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier Sent: Thursday, May 31, 2007 12:30 AM To: [log in to unmask] Subject: Re: [TN] RoHS compliant laptop with early failure Hi Reuven, Actually, it is not quality but inadequate or non-existant DfR [design for Reliability]. Solder joints are subject to the same creep-fatigue whether they are Class 1 or Class 3-the difference may be that the operational environment may-may- be more severe for Class 3 product. But I have seen Class 1, or more accurately Class 0 (Class minus 1?) [unsupported holes] in automotive under-the-hood environments. Werner ************************************** See what's free at http://www.aol.com. --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------