Patent ID: 9541920
Date: 2017-01-10
CPC Classifications: G05B,H01L

Claim:
1. A method for positioning a transfer unit including a plurality of support pins for supporting a bottom surface of a peripheral portion of an object to be processed, a plurality of intermediate pins disposed at an inner peripheral side of the support pins, and a pick having at a leading end thereof a detection unit configured to detect presence or absence of the object, the pick being approachable and separable from a rotatable and vertically movable mounting table, the method comprising: a height determining process of determining a height reference position of the pick by detecting an upper edge of one of the support pins by the detection unit; a first coordinate determining process of obtaining first coordinates which are coordinates of said one of the support pins having the rotation center of the pick as an origin; a second coordinate determining process of obtaining second coordinates which are coordinates of one of the intermediate pins having the rotation center of the pick as an origin; a third coordinate determining process of obtaining third coordinates which are coordinates of the rotation center of the mounting table based on the first and the second coordinates; and a final process of obtaining a forward moving angle, a forward movement starting point and a forward movement reference amount of the pick based on the first to the third coordinates, wherein the height determining process includes: making said one of the support pins directed toward a loading/unloading side of the object, positioning said one of the support pins and the pick such that said one of the support pins is detected by the detection unit; lowering said one of the support pins that has been detected and detecting the upper edge of said one of the support pins in response to non-detection of said one of the support pins; and determining the height reference position based on the height position where the upper edge is detected.