Contact Properties Analysis And Design Of End Effector For Large-Size Wafer Transfer Robot

Integrated Circuit(IC) as core of electrical information industry is one of the new high technologies which promote the national economy and information-based social development. Wafer transmission system is an essential part of IC equipment. As an important part of IC equipment, wafer transfer robot must transfer wafers precisely, fast and steadily. As an important part of transmission, the end effector of transfer robot greatly affects the wafer high efficiency and reliable transmission.Aim at high friction force and small deformation requirements, according to the national 973 project "Research on the foundation of super large scale integrated circuit manufacturing equipment" (granted No.2009CB724206), this dissertation studies the contact properties of wafer and two kinds of end effector (friction transmission end effector and vacuum absorption end effector), then design and optimize the end effectors. Finally, the experiments of verifying end effector performance are studied.In the aspect of friction transmission end effector research, the dissertation firstly analyzes the wafer material parameters. The wafer deformation with different thickness under different contact way is analyzed. Aim at the minimal deformation, the friction transmission using convex contact is determined. According to the convex contact, based on the bionics, a new way of using gecko bristle micro-array contact convex is proposed for wafer transmission. The contact model between contact convex and the wafer is established. Combing with the contact theories, the dissertation comparatively analyzes the relationship of the friction force and parameters of different contact convexes, that is stainless convex, rubber convex and bristle convex. Finally, through the static and dynamic characteristics simulation analysis, the friction transmission end effector is designed.In the aspect of vacuum absorption end effector research, aim at the minimal deformation, the relationship among the location of absorption points, the number of absorption points and the wafer deformation is researched. Through the analysis, the distribution of vacuum absorption points with minimal wafer deformation is determined. The dissertation researches the relationship of the friction force and the parameters of vacuum absorption points. Then the friction expression is deduced. Finally, based on the theoretical analysis, through the static and dynamic characteristics analysis, the vacuum absorption end effector is designed.Finally, the experiment system of verifying the end effector performance is established. The performance of friction transmission end effector and vacuum absorption end effector is verified by experiments respectively. The experimental results demonstrate that the friction transmission end effector with micro-array contact convex greatly improves the acceleration of stable wafer transmission, which is better than other friction transmission end effectors. The vacuum absorption designed for large-size and ultra-thin wafer transmission greatly improves the acceleration of stable wafer transmission and reduces the deformation of wafers.