I believe you are looking at a barrel crack in the middle of a plated through via (PTV). This is a typical failure mode from "Z" axis expansion of the material due to thermal excursions. The thermal excursions of assembly/rework could induce this failure mode. Fabrication variables like copper thickness/quality or the type of material used in fabrication could be contributing factors. It is possible that a couple of those dark lines on the right side (middle and bottom) of the PTV in your picture are of material delamination. Paul Reid PWB Interconnect Solutions Inc. -----Original Message----- From: Al Onderick [mailto:[log in to unmask]] Sent: Thursday, November 04, 2004 5:55 PM To: [log in to unmask] Subject: [TN] Via hole failures (with pictures) I have a couple of boards that have failed at a customer site. After testing, a via was identified as open. The following link is a picture of the cross section. http://www.tier1gear.com/temp/via_crack.jpg The board was .062, the via .010 and the surface finish immersion white tin. I would appreciate any insight into what may cause a failure like this. Al Onderick National Instruments --------------------------------------------------- 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 -----------------------------------------------------