摘要 |
A wafer-fetching sensing device for wafer storage apparatus uses a planar detection means to replace a conventional linear detection means to detect if a wafer is properly positioned at a desirable access level before being moved out of an access opening of the wafer storage apparatus by a robot. Wafer tilting and damage incident that might otherwise happen thus may be avoided. Only a correctly positioned wafer will be fetched. A warning signal will be generated when the wafer is not properly positioned so that preventive action may be taken to avoid wafer damage. Production yield thus may be increased.
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