Design and control of a novel linear wire bonding head

Abstract

Wire bonding has been one of the standard operations in plastic integrated circuit (IC) package assembly for a long time. With the development of IC assembly technology, the equipment of wire bonding should be improved for even higher performance. Thus, a novel linear wire bonding head driven by a permanent magnet linear motor (PMLM), instead of the rotary bonding structure, is designed to optimize the system structure and improve the performance of wire bonding. Based on two different wire bonding states, the switching control scheme corresponding to this linear structure is presented. In free motion, the position tracking control suppressing the vibration of flexible parts of the structure is performed at high speed and acceleration. In constrained motion, the active force control with direct contact force feedback is adopted for more precise bonding force compared with the indirect current feedback control in previous rotary structure. The experiment results show higher performance of wire bonding because of the combination of novel linear structure and control scheme.