Glass slide-out detection

Challenge:

Glass that has slid out from predetermined positions causes an impact between robot arm and glass. For secure handling, it is important that glass that has slid out of position in a cassette is detected. The detected edge position should be the same for all of the glass substrates in the cassette, from the bottom glass substrate to the top one. There is not enough space to place sensors under the cassette.

Solution:

Laser coaxial retro-reflective type sensors detect that each wafer is at the same position measured over the full length of the cassette without dispersion. Even reliable detection of transparent glass is achieved.

Benefit:

Fewer problems with secure handling and saving on space and wiring.