Mr. Tegehall, What vendor dye penetrant was used? victor, -----Original Message----- From: Tegehall Per-Erik [mailto:[log in to unmask]] Sent: Wednesday, September 25, 2002 2:07 AM To: [log in to unmask] Subject: Re: [TN] CGAs Edwin, I performed a study for European Space Agency last year of the reliability of ceramic BGAs and CGAs (625 I/Os) for space applications. The components were mounted on two different typas of PCB laminate: polyimide/glass and Thermount (polyimide/aramid). For the BGAs mounted on polyimide/glass, the first failures occured after about 500 cycles (-55 C to +100 C). No failure had occurred for the CGAs after 1000 cycles although the columns were rather deformed and the corner columns had quite large cracks. Both the BGAs and the CGAs mounted on Thermount survived 1000 cycles. Whereas the corner balls on the BGAs had cracks that covered about 50% of the pad area on the CGA (evaluated using a dye penetrant) after 1000 cycles, no cracks could be found in the columns to the CGAs nor any deformation of the columns. Thus, the CGAs do survive considerably higher numbers of thermal cycles than BGAs do. Unfortunatelly, the budget and time frame for the project did not allow me to continue the test after 1000 cycles so I cannot give you a figure for the improvement but I estimate that it is at least a factor of four. Per-Erik Tegehall IVF, Sweden -----Ursprungligt meddelande----- Från: Louis, Edwin @ CSE [mailto:[log in to unmask]] Skickat: den 24 september 2002 15:39 Till: [log in to unmask] Ämne: [TN] CGAs Can anyone please give me their experiences with Column Grid Arrays? How do you use them,do they survive thermal cycling and how can one calculate the size solder pillar required for a given CTE difference? ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------