Patent ID: 6867856

Claim:
An apparatus for reading a mark on a wafer, comprising: a support structure and comprising: a back support having an upper side, a lower side, a first vertical support side, and a mark reading area, wherein the mark reading area has at least one gradation; a vertical support having first, second, and third sides, the first side coupled to the first vertical support side of the back support; and a wafer support having a first side coupled to the upper side of the back support and a second side coupled to the second side of the vertical support, the wafer support having first and second major surfaces and at least one slot extending into the wafer support from the first major surface, the at least one slot for receiving said wafer such that a portion of said wafer having the mark extends through the at least one slot; means for illuminating the mark on said wafer; and means for reflecting light from said wafer to the at least one gradation of the mark, reading area, wherein said means for reflecting light is coupled to the support structure.