Hi Per! I finally found the paper on the bent columns! I think this was part of an ECTC or IMAPs conference (sorry, I didn't record where I got it). The paper is titled "Robustness of Deformed Ceramic Column Grid Array Columns", authors Ellyn Ingalls and Janet Jozwiak of IBM Microelectronics in Hopewell Junction NY. I have Ingalls email listed as [log in to unmask] . I interpret their data slightly different than the authors (I believe they tried to put a more positive conclusion on the data) - I think the data shows that once a column gets bent, a severe drop in reliability occurs. Take a look at the paper and let me know what you think. Dave Tegehall Per-Erik <[log in to unmask]>@ipc.org> on 06/04/2002 02:26:34 AM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to Tegehall Per-Erik <[log in to unmask]> Sent by: TechNet <[log in to unmask]> To: [log in to unmask] cc: Subject: Re: [TN] Re column grid arrays Hi David, What do you mean with bent? The information I have got from IBM is that it is normal that columns ar tilted due to the fact that fillets will be assymetric caused by an allignment to the edge of the solder pads. This sholdn´t affect the reliability. But from your description I get the impression that there is a bend on the columns. Is that correct? Where has the IBM paper been published? Regards Per-Erik Tegehall IVF, Sweden -----Ursprungligt meddelande----- Från: Dave Hillman [mailto:[log in to unmask]] Skickat: den 31 maj 2002 22:06 Till: [log in to unmask] Ämne: [TN] Re column grid arrays Hi Earl! Hey, did you ever get an feedback on how the CCGA's performed in their use environment (and what was the use environment conditions)? We have successfully placed CCGA's in both the semi-automated and automated assembly modes but if the columns are bent - even slightly - we have seen a pretty hefty reduction in solder joint fatigue life (avionics use environment). I have an IBM paper which showed similar results. Dave Hillman Rockwell Collins [log in to unmask] Earl Moon <[log in to unmask]>@ipc.org> on 05/31/2002 12:34:20 PM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to Earl Moon <[log in to unmask]> Sent by: TechNet <[log in to unmask]> To: [log in to unmask] cc: Subject: Re: [TN] NTC - The Gregory's are a team now... Never experienced any problems with CCGA's either in production or replacement. I did hundreds of these things with the SRT because of an upgrade. It took almost six months for all the replacements at 24 per board with 1200 columns. Only minor problem was with sorting out GSM placement accuracy concerning the vision system. Really had to watch column alignment though as you say. Other than that, no problems. I guess, as I don't clearly remember, the force issue was resolved as a function of machine programming but the parts were so heavy anyway, I don't think it mad a difference as they just sunk into the paste and aligned very well. Interesting stuff, eh Gaby? Earl ---------------------------------------------------------------------------- ----- 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 e-mail to [log in to unmask]: SET Technet NOMAIL 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 1.8d 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 e-mail to [log in to unmask]: SET Technet NOMAIL 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 1.8d 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 e-mail to [log in to unmask]: SET Technet NOMAIL 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 -----------------------------------------------------