A direct write and laser delete system for making engineering changes in which top surface metal C4 pads each has a small satellite pad connected to it by a short connecting line that is deleted if an engineering change is to be made. Vias connect the satellite pads to a "personality" wiring layer in...http://www.google.de/patents/US5294754?utm_source=gb-gplus-sharePatent US5294754 - Direct write EC single metal layer
