I concur with Denny Fritz. The IPC PCQR2 committee has designed a series of
"Test Vehicles " (TV)  that are 18" X 24" and comes in 6 MLB versions:
- 6 layer (.031" or .062" thick ),
- 12 layer ( .062"thick ),
- 18 layer ( .093" thick )
- 24 layer (.125" or .250" thick )

Each TV is compromised of 352 modules (1.0 inch square each). Each module is
designed to asses a specific quality attribute and process capability.
Data (electrical test data) is collected from a test batch of 30 TV boards
processed simultaneously. The data is evaluated thru a proprietary software
and the process capability is assessed. The information is then stored in a
data base for reference.

Best Regards
George Milad
Chairman IPC Plating Committee