TIPPINST – Following on from a comment left by John McCormac who recommended that I look a the work done by Markus Kuhn into Tamper resistant smart card processors I came across an article that describes the process.
Hot Fuming Nitric acid
acetone in an ultrasonic bath
Hydrofluoric acid (Very dangerous)
confocal Microscope with a CCD camera
The article describes the process in detail as well as photo and resulting images.
Design Principles for Tamper-Resistant Smartcard Processors