Hi Roger, First, you indicate that the PWB design has passed short-term vibration testing without incident in the past. What exactly is that short-term vibration testing that the PWB passed? Has a qualification vibration test or an ESS vibration testing been done? If the answers to the above questions indicate that the design approach is structurally sound, then it tends to indicate that the problem is associated with workmanship. Secondly, does this CCA use ENIG as a final finish on the solder pads? And if so, have you considered that the presence of ENIG might be resulting in the "black-pad" contamination issue that is well known as the Black-line nickel (BLN) low level defect associated with ENIG that can occur unpredictably for even the best PWB manufacturers, that goes undetected and ultimately results in improperly formed solder joints creating failures due to fractures in the solder joints that cause electrical opens and/or intermittences during ESS vibration and temperature testing and/or actual field exposures to the same types of environments. Regards, faz -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Roger Stoops Sent: Thursday, January 06, 2005 1:19 PM To: [log in to unmask] Subject: [TN] Solder Joint Failures after Short-term Vibration Hello all, We are having an ongoing problem with solder joint failures on a 144-pin PQFP processor, after short-term vibration. The board layout and mechanical mounting apparatus were designed with vibration in mind, and have passed vibration testing in the past. The same processor is used on a dozen other assemblies, none of which have this problem. The solder joints appear to exhibit dewetting, although there is a toe and heel fillet. The heel fillet is unusually large, and the top of the PQFP lead has a grainy appearance instead of a matte or shiny appearance. Some leads can be pushed off the solder joint with very little pressure. Sn62Pb36Ag2 solder is being used, and our EMS provider continues to claim that boards meet IPC-A-610 class 2 requirements. Any ideas as to what may be causing solder joint failures? Also, any suggestions or recommendations (preferred) for a test house to provide x-ray, microsection and composition analysis? TIA & Best Regards, Roger M. Stoops, CID+ Trimble Navigation Ltd., Dayton, OH, USA Ph: +01 937.245.5288 Fax: +01 937.233.7511 Oh, and BTW, changing EMS providers is not an option... --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 ----------------------------------------------------- ****************************************** The information contained in, or attached to, this e-mail, may contain confidential information and is intended solely for the use of the individual or entity to whom they are addressed and may be subject to legal privilege. If you have received this e-mail in error you should notify the sender immediately by reply e-mail, delete the message from your system and notify your system manager. Please do not copy it for any purpose, or disclose its contents to any other person. The views or opinions presented in this e-mail are solely those of the author and do not necessarily represent those of the company. The recipient should check this e-mail and any attachments for the presence of viruses. The company accepts no liability for any damage caused, directly or indirectly, by any virus transmitted in this email. ****************************************** --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 -----------------------------------------------------