Hi Larry!
Something I've seen done before, is to either have a silkscreened outline of the part put on the board, or more recently with a board we built here, have "placement cheverons" etched into the board at the 4-corners of the device. Go to:
http://www.stevezeva.homestead.com
and look at "Placement Chevrons". Of course these have to match the outline of the body of the part, but the operators can easily tell visually, if the part is placed accurately or not....pretty slick if you ask me. But you do have a battle getting the designers to incorporate something like that.
-Steve Gregory-
I'm wondering what you all use for placement verification of uBGA? Before running a new setup, we take a solder sample PCB and put double sided tape on it. Place the components on the PCB, when its finished the machine operator hauls the PCB over to the techs for them to Ersa and xray it to verify placement accuracy of the uBGA. I'm looking for something which would allow the machine operator to verify the placement themselves. Purchasing additional Ersa and xray equipment wouldn't be an option. Any suggestions?
Larry
-Steve Gregory-