thermal shock 10 times and electrical test as part of screening or burn-in. jk -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Bev Christian Sent: Friday, May 13, 2005 3:17 PM To: [log in to unmask] Subject: Re: [TN] NDT Question Werner, I used the hokey expression of "intermittent micro-cracks" to waylay people suggesting I use x-ray of one sort or another. And, yes, I was talking about a full crack across the entire SJ. The problem with this part is that it is so complex I am not sure that 100% functional testing is possible. Bev RIM _____ From: [log in to unmask] [mailto:[log in to unmask]] Sent: May 13, 2005 3:14 PM To: [log in to unmask]; Bev Christian Subject: Re: [TN] NDT Question Hi Bev, It sort of dependents. First there is no such thing as intermittent micro-cracks in SJs. If they are micro-cracks, they can be present starting about 40% into the life of the SJs, but they do not impact electrical signals, intermittent or otherwise. If you have a full solder joint fracture, electrical signal interruption will be intermittent, because the fracture surfaces are in at least some slight compression and make very good 'connector surfaces.' If you have fully fractures SJs, they will only show intermittent opens if they are disturbed by either temperature changes or mechanical shock/vibration. The best way to find them is to do functional tests during vibration loading. Regards, Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904 E-mail: [log in to unmask], Website: www.engelmaier.com --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------