Hi Bob,
We use XRF for most plating thickness analysis (PCB and other plated parts).  We cross-section and verify either optically or with SEM/EDS when we can.  Most of the time, we're within about 5%.  We use several Fischer Technologies systems. 
http://www.fischer-technology.com

We've had positive experience with these tools in the NJ lab and have since implemented this tool as part of our global IQC.



-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Wettermann
Sent: Tuesday, October 18, 2016 8:29 AM
To: [log in to unmask]
Subject: [TN] Measuring Gold Thickness

Outside of x-sectional measurements for QA. can someone please share their favorite method/instrument for measuring gold thicknesses on PCBs?

Thanks

Bob/BEST