Conveyance Method of Thin Plate by Using Multiple-phase Air Flow

Abstract

This paper deals with a transfer method for a thin plate by levitating with multiphase air flow. Non-contact transfer methods are required for glass plates and semiconductor wafers in order to keep them clean. In the proposed method, a thin plate was slightly levitated with a small inclination by blowing and sucking air from orifice restrictors, and airflow was blown against the lower side of the plate so that the driving force was generated. The plate was continuously carried by shifting the air flow pattern in accordance with the plate position. 48 air flow slots were arranged with intervals of 15 mm. The velocity of a plate with dimensions of 90 mm × 100 mm × 2 mm and a weight of 139 g was almost linearly increased at an acceleration of 15 mm/s² and reached 50 mm/s after driving for 3 s. The levitated height was 0.13 and 0.28 mm at the lower and higher sides at air pressures of the positive and negative restrictors of +7.0 and less than -3.0 kPa, respectively. In the case of an initial velocity of 60 mm/s, the plate was turned in reverse after moving for 100 mm. The plate can move reciprocally by reversing the air flow pattern.