Method and apparatus for handling wafers

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United States of America Patent

PATENT NO 5479108
SERIAL NO

07981801

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ATTORNEY / AGENT: (SPONSORED)

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Abstract

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A method and apparatus for handling wafers. A wafer pick moves along a horizontal x-axis to unload a wafer from a cassette and position the wafer over a chuck. The chuck moves upwardly along a z-axis perpendicular to the surface of the wafer and lifts the wafer off the pick. The pick retracts through a slot in the chuck and a test probe moves along the x-axis to position itself over the wafer and chuck with reference to a calculated wafer center. The chuck then moves upwardly to engage the surface of the wafer with the probe. Wafer characteristics are tested at several test points located on a circle on the surface of the wafer by repeatedly lowering the chuck, rotating the chuck by a small amount, and raising the chuck to engage the wafer with the probe. The probe is then positioned to test another circle of points.

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Patent Owner(s)

Patent OwnerAddress
CHENG DAVIDSUNNYVALE CA

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Cheng, David 711 Hibernia Ct., Sunnyvale, CA 94087 71 5423

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