Rich, You should expect mechanical failure modes. Things like cracked vias are a possibility. I've seen via test points popped of the board. Best way to characterize specific failures would be to run a board test after or during exposure to stress, then root causing per failure data....again thoroughly inspect, under microscope, for physical mechanical damage. Barrie Fraley EMC Corporation Electrical DVT/HALT 508-249-4472 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Richard Kraszewski Sent: Tuesday, February 01, 2005 4:19 PM To: [log in to unmask] Subject: Re: [TN] Behavior of Via's in low temperature cycling What type of failure mechanism(s) would you expect? Rich Kraszewski Advanced Manufacturing Engineer - KEDS Phone: 260.925.8919 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jeffrey Bush Sent: Tuesday, February 01, 2005 3:40 PM To: [log in to unmask] Subject: Re: [TN] Behavior of Via's in low temperature cycling Thin copper plating, poor ductility of plating deposit, under cured resin system - to name a few. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: Richard Kraszewski [mailto:[log in to unmask]] Sent: Tuesday, February 01, 2005 3:05 PM To: [log in to unmask] Subject: [TN] Behavior of Via's in low temperature cycling I have a 6 layer board with a 10-mil standard through hole (not micro) via. Trying to understand what type of stresses 7 factors would drive failure of this via at cycling from -40degC to 125degC with normal FR4. Any thoughts or sources of references would be appreciated. Thanks. Rich K / KEDS --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------