Hi Ken - is there an end cap metallization such as nickel or copper between the solderable surface finish and the ceramic metallized layer? Dave Hillman Rockwell Collins [log in to unmask] Ken Bloomquist <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 04/28/2008 02:38 PM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to Ken Bloomquist <[log in to unmask]> To [log in to unmask] cc Subject [TN] Cracking Ceramic Cap Hi All, We are experiencing a high failure rate on a ceramic capacitor. I've asked Steve to post the pictures to help describe the problem, "Cracked Cap 1, 2 and 3". The capacitor that is cracking is used nineteen times on this assembly and none of the others ever crack. The assembly process is as follows: Paste, place SMD, reflow and wash secondary side. Paste, place SMD, reflow and wash secondary side. Hand place through-hole components, wave solder in selective pallet and wash. In-circuit test, capacitor fails about 5% of the time. Operator removes part and the metalized end cap falls off. I have looked at the handling of the assembly and don't see anything that could contribute to the problem. I've looked at ICT and nothing appears to be slamming into the part. The only thing I see different with this part from the others is the proximity to the stud from the D-sub connector. It takes a little pressure to put the connector stud into the hole but nothing excessive. I'm wondering if there could be anything happening due to thermal expansion of the large solder joint next to the cap. Picture "Cracked Cap 1" shows the proximity of the capacitor to the connector stud, http://stevezeva.homestead.com/files/cracked_cap_1.jpg Picture "Cracked Cap 2" shows a how the connector is installed and soldered, http://stevezeva.homestead.com/files/cracked_cap_2.jpg Picture "Cracked Cap 3" shows the unsoldered connector stud, http://stevezeva.homestead.com/files/cracked_cap_3.jpg Thanks for looking at this, KennyB --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 -----------------------------------------------------