A substrate, preferably constructed of a ductile material and a tool having the desired shape of the resulting device for contacting contact pads on a test device is brought into contact with the substrate. The tool is preferably constructed of a material that is harder than the substrate so that a depression...http://www.google.co.uk/patents/US20040093716?utm_source=gb-gplus-sharePatent US20040093716 - Membrane probing system
