| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the deviation of position of a substrate due to the release of attraction between the substrate and a substrate mounting means. <P>SOLUTION: Lift pins 81, 82 are descended with such a speed profile that attraction between a sucker 83 provided on the lift pin 81 and the substrate 12 can be maintained. In this case, the descending speed V of the lift pins 81, 82 is set so as to satisfy a formula: (1) P<G+S in which P is a pressure between the substrate 12 and a stage 14, G is the weight of the substrate 12 and S is an attraction force between the substrate 12 and the sucker 83. Further, the pressure P between the substrate 12 and the stage 14 is operated to satisfy another formula: (2) P=2∫<SB>0</SB><SP>L/2</SP>P<SB>n</SB>, (P<SB>n</SB>=P<SB>n-1</SB>+αμLV/h<SP>2</SP>) ähere, L is the length of a long side of the substrate 12; α is a proportional constant; μ is an air resistance; h is a distance between the substrate 12 and the stage 14}. <P>COPYRIGHT: (C)2008,JPO&INPIT |
