US Patent 7576287 Lot traceable printed circuit board

A lot traceable printed circuit board (PCB) includes a substrate having thereon a patterned circuit layer and a working zone carrying production information related to the PCB itself. The working zone includes a plurality of code boxes, wherein each of the code boxes has a first probe region and second probe region. A single set of resistance test loop is disposed within the first probe region. Four sets of resistance test loops are disposed within the second probe region. A frying probe tester is used to probe the set of resistance test loops respectively for abstracting the production information recorded in the working zone.