Wafer Cassette Detection Under Water
Challenge
To sense the presence of a wafer cassette on a conveyor submerged in water
Solution
Silicon wafers are transported from one process to another in cassette on a conveyor that is totally submerged in de-ionized water. A DF-G1 sensor has teflon-encapsulated opposed-mode fibers that are located on either side of the conveyor. When the cassette is present, the opposed beam is broken.