This would only be possible on BGA with adequate spacing between BGA rows near the center. It is a good idea if you can provide it. What size hole? .024" dia. ? It is not done here, we use a non-functional board for this setup. Tim Easterling Cadd Manager Commercial Engineering SCI Systems Inc. 8600 S. Memorial Parkway MS 200 Huntsville, Al. 35802 (256)882-4426 (ph) (256)882-4700 x4426 (voicemail) (256)882-4304 (fx) ------------------------------------------------------------------------------- ------------------------------------- Hi All, I'd like to know how many designers provide an unplated hole under each BGA component in a design, so that a thermocouple can be placed to monitor temperature. I'm thinking of doing this in all of my designs to help make it easy to create a temperature profile on a new design. Do you use more than one hole or is one sufficient? Regards, Bob Walker [log in to unmask]