Hi Glenn! One metallography trick you may want to try is to "load" your mounting compound with ceramic filler. We do this about 50% of the time on our FC cross sections. Most of the metallography suppliers offer a ceramic filler as a standard consumable product. This methodology doesn't help on the brittle die issues but it does increase the overall "hardness" of the mount which decreases the tendency of the softer materials polishing faster than the harder materials. It also causes you to go through silica paper/diamond polish at a much faster rate. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] "Pelkey, Glenn" <[log in to unmask]>@IPC.ORG> on 04/23/2001 01:29:59 PM Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to "Pelkey, Glenn" <[log in to unmask]> Sent by: TechNet <[log in to unmask]> To: [log in to unmask] cc: Subject: [TN] Flip Chip Sample Preparation for Cross Section Hi all, What methods have any of you used for cross sectioning flip chip BGAs? We have a large flip chip die, attached to a thin interposer, and want to inspect the inside die bumps/joints. Our concern is with the brittle nature of the die and the lack of good support during the sectioning operation. The current option is to cut next to the die, mount sample in epoxy, and use 0.3 micron alumina for a very slow polish to the area of interest. Hopefully, somebody out there has dealt with this before and has a better idea. Thanks for all your help, Glenn --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------