Impact vibration control of a wire bonder through damping treatments

A procedure for solving the vibration problems in a wire bonder is establis hed through experimentation and modeling. During the bonding operation, the impact of the capillary of the bonder on the workpiece generates undesirab le dynamic forces that ultimately reduce the bond yield and bond quality. E xperiments simulating the bonding process show that the force exerted by th e capillary on the workpiece overshoots the desired value with subsequent o scillations. Mode shape measurements indicate that an operating arm actuall y rocks about its pivot and exhibits severe bending near its capillary. Thi s vibration mode leads to the development of a simple model for predicting the arm response and two feasible ways for improving the bonder's performan ce. Numerical results from the model show that force overshoots can be redu ced by adding a damper to the arm and choosing softer materials for the cap illary. For a critically damped wire bonder, there is a threshold for the s triking speed below which force overshoots are close to the minimum value.