Patent ID: 11923222
Assignee: TOKYO ELECTRON LIMITED
Field: Handling (Mechanical engineering)
Classification: CPC B  H | IPC B  H

Claim 6:
7. A method of determining a gripping of a substrate in a substrate transfer device,
wherein the substrate transfer device includes: a support part configured to support a substrate to be transferred and provided with a plurality of engagement portions which are engaged with an edge of the substrate on a first side of the substrate; a gripping part configured to move toward or away from the plurality of engagement portions and provided with a plurality of contact portions which come into contact with the edge of the substrate on a second side of the substrate when moving toward the plurality of engagement portions; at least one of a plurality of detection parts provided in each of the plurality of contact portions, respectively, the plurality of detection parts being configured to detect distortion amounts of the plurality of contact portions,
the method comprising:
determining a state of the gripping of the substrate based on a degree of the distortion amounts obtained by the plurality of detection parts when the substrate is gripped by the plurality of engagement portions and the plurality of contact portions,
wherein the determining the state of the gripping of the substrate includes, when the distortion amount detected by one of the plurality of detection parts is equal to or greater than a first threshold and a difference in the distortion amounts detected by the plurality of detection parts is equal to or greater than a second threshold, determining that a defective gripping has occurred.