Abstract: IC packaging device and other high-speed and high precision equipment require the mechanical structures of the high-speed actuator to minimize inertia under certain stiffness constraints. Optimization approach using equivalent static loads method is recently developed effective for optimal design of flexible multi-body dynamics. The optimization approach is modified according to the dynamic behavior characteristics of high-speed mechanism. The quasi-static analysis with kinetic degrees of freedom is used to solve equations of the discrete structure dynamiss with motion joints; The strain energy element sensitivity is changed by divided element kinetic energy, such that the changes of elements influent stiffness as well as inertial force of the structure; A non-dimensional measurement of elements is proposed to judge the important of an element at any situation The proposed method is used for optimal design of a die bonder of microelectronic packaging device, and three methods are compared, the results show that the quasi-static analysis with kinematic degrees of freedom is important for structures with motion joints. When the speed is very high, the inertia has greater impact of the vibration than the stiffness. Numerical results show that the optimal method of optimal structure design of high-speed mechanism to be effective.

Key words: Equivalent static loads method, Flexible multibody systems, High speed mechanism, Topological optimization