Development of High Precision Linear Transfer Platform using Air Floating System for Flat Panel Display Production and Inspection Process

Abstract

Recently, there is an increasing requirement for high precision linear transfer platform using for flat panel display production and inspection process such as liquid crystal display, plasma display panel, and organic light-emitting diode. As next generation technology in the area of transfer platform, precision positioning and transfer flatness control under the 10m is required for inline process such as automatic optical inspection, surface treatment, and marking. As magnetic roller conveyer type is used as transfer platform for flat panel display, there are many problems such as contamination of panel by contact between roller and panel, deterioration of quality, and uncontrollable flatness. The requirements of the high precision linear transfer platform are high positioning accuracy and high transfer flatness. To satisfy these requirements, it has to be designed with the direct drive linear motion system and air floating system. In this work, linear transfer platform having air floating system is proposed, where moving system using linear motor is mounted at the inside of the air floating system, and air floating system is used for floating the flat panel display panel, control system are used for performance requirement. The developed high precision linear transfer platform is verified by performance test in the condition of 50mm step motion for 300mm stroke. From the performance test, positioning accuracy is measured as 4.6μm and repeatability is measured as 0.4μm. Velocity ripple is measured as 0.3% at transfer velocity of 100mm/sec. The transfer flatness is measured as 2.0μm, air gap is measured as 34.5μm in the condition of 1kg payload, and straightness is measured as 9.0μm. From the performance test, developed linear transfer platform is applicable for the flat panel display production and inspection process.