Holding Characteristics in the Vertical Direction of Porous Vacuum Chucks

In recent years, vacuum chucks have been applied to various devices to hold and carry manufactured products. Especially, the usage of vacuum chucks is very effective for handling a LCD glass panel and a silicon wafer for semiconductors in order to reduce the deformation of them and keep their flatness. It is said that a vacuum chuck utilizing porous material has an advantage that the flatness of an object held by this kind of chuck is superior to that by other types of vacuum chucks with vaccum holes and circumference vacuum grooves. However, there are few published papers that the detailed holiding characteristics of a porous vacuum chuck are clarified. In this paper, the holding characteristics of the porous vacuum chuck are investigated numerically and experimentally.