A Study on Five-Bar Manipulators for Semiconductor Packaging Applications

In semiconductor packaging applications, e.g., wire bonding, high speed and high precision are two core requirements. Five-bar linkages are good candidates for 2-DoF (degree of freedom) semiconductor manipulation because of its parallel topology and therefore its potential for high speed and high precision. In order to find the best five-bar structure, the workspace volume index (WVI), the ratio of workspace volume to machine envelop size, is proposed as a measure for kinematic performance. Optimal design problems are formulated by regarding WVI as the objective function and other requirements on dexterity and singularitylessness as the constraints. Based on the design formulation, two candidate manipulators, the 5-R and PRRRP manipulators are compared with respect to WVI, kinematic accuracy, stiffness and velocity transmission, etc.