Method for aligning wafers within a semiconductor wafer cassette

DETAILED DESCRIPTION An object of this invention is to provide a method and apparatus for precisely aligning wafers within a cassette regardless of the condition or positional accuracy of the cassette itself.
In accordance with the preferred embodiments of the present invention, an improvement is presented which allows precise positioning of wafers within cassettes in preparation for removal of the wafers by automated equipment.
The improvement includes mounting two sawtooth jigs having V-shaped grooves on the cassette tray upon which the cassette is to be placed.
The sawtooth jigs extend up into the base of the cassette to lift and support the wafers within the cassettes.
Each wafer is supported at two points by opposing grooves of the sawtooth jigs.
The sawtooth jigs thus precisely align the wafers within the cassette, facilitating the removal of the wafers by automated equipment.
An advantage of this invention is that the wafers are precisely supported within opposing V-shaped grooves of the sawtooth jigs.
Since these jigs are not subject to deforming processes, such as hot dips, they tend to stay precisely aligned.
Furthermore, since the grooves of the jigs are V-shaped, the base portion of the wafers are substantially immobilized ensuring precise alignment with the vertical transport mechanism of the semiconductor processing equipment.
These and other object and advantages of the present invention will no doubt become apparent upon a reading of the following descriptions and a study of the various figures of the drawing.