A low-cost imaging system capable of recognizing and counting semiconductor good dice is designed and is proven experimentally to be effective. The system utilizes a commercial scanner with the least modification of its inner optics by a beamsplitter-insertion method. Patterns on specular die surfaces therefore can be grabbed clearly, which results in the marks on defective dice being distinguishable. Aiso, a mask algorithm is developed to count the good dice on an adhesive tape, according to the gray-level histogram and the converted binary picture of the scanned image. The built-in software associated with the Scanner, which is reliable and user-friendly, can also be incorporated into the designated algorithm without paying an additional price for system development. #1998 Society of Photo-Opt/cai Instrumentation Engineers. S0091-3286(9B)01409-3 Subject terms: optical counting; scanner; semiconductor dice. Paper 17127 received Dec. 12, 1997; revised manuscript received Mar. 24, 1998; accepted for publication Mar. 24, 1998.
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