This 35ppm that DuPont gives is an average: 27ppm below Tg, 45 above. Therefore lower expansion than the FR4. Tony Steinke <[log in to unmask]> wrote: Frank, After reviewing my data sheets for the CB100 theTg of the cured silver epoxy is only 115C with a 35ppm TCE, I imagine that would explain what you experienced on your boards. The key word is "Conductive ViaPlug" not "Conductive ThruHole Plug" Tony Steinke AIT-Atlanta Inc. Tony Steinke ----- Original Message ----- From: "Franklin Asbell" To: Sent: Tuesday, March 23, 2004 1:08 PM Subject: Re: [TN] PWB delamination and silver epoxy fill > The reason I say they are probably large vias is we had seen that once in > the past. Customer spec'd a 28 mil via with silver epoxy fill. They placed a > heavy BGA component right over those filled 28 mil pads/vias...the larged, > silver-filled vias acted as a heat-sink drawing too much heat into them > causing delamination only around those vias. We reduced the hole size, the > problem went away. We also did another job for them where we could not > reduce the hole size, we used ceramic fill instead of epoxy, no problems at > all... Just one persons experience, hope this helps... > > Franklin > > --------------------------------------------------- > Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- Do you Yahoo!? --------------------------------------------------- Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- Yahoo! Finance Tax Center - File online. File on time.