A method and apparatus for front to back substrate registration is described. Alignment characteristics of features on surfaces of substrates can be used to physically align substrates with a multiplicity of integrated alignment optics. Measurement of offsets of the integral alignment optics are used...http://www.google.de/patents/US20060042106?utm_source=gb-gplus-sharePatent US20060042106 - Method and apparatus for registration with integral alignment optics
