Doug, We use an SMT crystal, which survives our reflow, but has problems with hand soldering. The solder holding the crystal in the package reflows when the iron is held on the package instead of the PWB pad for an extended length of time. The crystal can also be damaged electrically by too much input power. You will need to do a failure analysis to determine how the crystals are failing. Jim Carlson Rockwell collins reliability Engineer "McCall,Doug" <Doug.McCall@BOCE To: [log in to unmask] DWARDS.COM> cc: Sent by: TechNet Subject: [TN] HC49 SMT Crystals and Reflow Soldering <TechNet@listserv .ipc.org> 07/16/2003 10:10 AM Please respond to "TechNet E-Mail Forum."; Please respond to "McCall,Doug" Hi All Does anyone have any experience of HC49 crystals failing test following Reflow Soldering with a standard 183 Deg-C Eutectic solder paste (Sn62 Pb36 Ag2). - The max temp found at crystal is 225 Deg-C; - Over 200 Deg-C is approx. 53 Seconds; - The crystal is over 200 Deg-C for 22 Secs longer than the component datasheet; - Pre-heat is ramping up at 1.8 Deg-C per second; - Time to 140 Deg-C is to long by 47 Seconds; The profile may have to be changed slightly, but any experience of failing SMT crystals and failure modes would be appreciated as the crystal spec apears to be very close to our profile parameters. Thanks. Regards, Douglas I McCall, PCB Manufacturing Engineer - Eastbourne, BOC EDWARDS, Marshall Road, Eastbourne, East Sussex, BN22 9BA UK Tel: +44 (0) 1323 501 147 Fax: +44 (0) 1323 509 824 mailto:[log in to unmask] Regards, Douglas I McCall, PCB Manufacturing Engineer - Eastbourne, BOC EDWARDS, Marshall Road, Eastbourne, East Sussex, BN22 9BA UK Tel: +44 (0) 1323 501 147 Fax: +44 (0) 1323 509 824 mailto:[log in to unmask] BOC Edwards is a part of BOC Limited Registered Office: Chertsey Road, Windlesham, Surrey GU20 6HJ Number 337663-English Register Ultimate holding company: The BOC Group plc _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------