Last thought on this topic: Over the past 18 months, CALCE has seen a significant increase in ceramic capacitor failures (thermal shock cracks, flex cracks, manufacturer flaws) among its customers. In terms of pure speculation, its possible that the huge demand for capacitors during the boom may have lead to some relaxation in process control. What this implies is that your process was borderline to begin with, and then the addition of caps with larger flaws or a lower fracture toughness simply lead to the introduction of failures where there were none before. Best Regards Craig -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Bartkowaik Christine Sent: Friday, August 17, 2001 6:56 AM To: [log in to unmask] Subject: Re: [TN] To wave or not to wave, that is the question... Kevin: We have no problem with 1uf caps (TANT). Thus I suspect: 1- thermal shock 2- too long a time in the wave >2 s I would not suspect moisture if the boards have already been thru a reflow oven and have not sat long. Chris -----Original Message----- From: Kevin Stokes [SMTP:[log in to unmask]] Sent: Thursday, August 16, 2001 4:26 PM To: [log in to unmask] Subject: [TN] To wave or not to wave, that is the question... Old problem: mounting ceramic capacitors to the bottom side of an assembly and your customer wants you to wave them on. We are having problems with 0805 0.22 uF and 0.1 uF caps going through wave and cracking during the process. We are following all of the standard protocols (preheat, etc.). My understanding is that 0805s are typically capable of handling this process. Anyone got any ideas short of moving the cap to the top or doing a double sided reflow? Kevin Kevin Stokes Reliability Manager Kimball Electronics Group (812) 634-4207 ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------