Patent ID: 6380000
Filing Date: 2002-04-30
Classification: H01L

Abstract:
A method for automatic recovery for a wafer table wafermap operation comprising the steps of:(a) moving said wafer table from a reference die in a first direction toward a first map die of current bin pick position of a wafer; (b) picking the first map die of current bin if said first map die is encountered; (c) if an alignment fail or no die is encountered, moving said wafer table back one die position along the reverse track of said first direction to the first map die; (d) finding the closest die coordinate from the map data of current bin in reverse direction to a forward die pick up direction toward said first map die and moving said wafer table to this closest coordinate; (e) if alignment fail or no die, repeating steps (c) and (d), otherwise finding the next die coordinate from map data of current bin in said reverse direction towards the first map die and moving said wafer table to this die coordinate position; (f) moving said wafer table to next map die of current bin in said forward direction if alignment fail or no die; and (g) picking this next map die of the current bin.