US 12,286,306 B2
Overhead transport system
Chieh Hsu, Hsinchu (TW); Guancyun Li, Hsinchu (TW); Ching-Jung Chang, Hsinchu (TW); Chi-Feng Tung, Hsinchu (TW); and Hsiang-Yin Shen, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsinchu (TW)
Filed on Jul. 23, 2021, as Appl. No. 17/384,360.
Claims priority of provisional application 63/160,517, filed on Mar. 12, 2021.
Prior Publication US 2022/0289492 A1, Sep. 15, 2022
Int. Cl. B65G 43/02 (2006.01); B61B 3/00 (2006.01); G01B 21/22 (2006.01); G01C 9/06 (2006.01); G01H 1/00 (2006.01); H01L 21/677 (2006.01)
CPC B65G 43/02 (2013.01) [B61B 3/00 (2013.01); G01B 21/22 (2013.01); G01C 9/06 (2013.01); G01H 1/00 (2013.01); H01L 21/67703 (2013.01); H01L 21/6773 (2013.01); H01L 21/67733 (2013.01); B65G 2201/0297 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of leveling an overhead rail structure for transporting a wafer cassette, comprising:
determining a length for each of a plurality of hangers configured to support the overhead rail structure;
leveling the rail structure by adjusting the length of the hangers; and
determining an alignment of at least one pair of the hangers with a laser transmitter along a first hanger of the pair of hangers and a laser sensor along a second hanger of the pair of hangers, wherein the first hanger and the second hanger are facing each other.