IMPEDANCE/ADMITTANCE MODEL OF ULTRASONIC TRANSDUCER SYSTEM IN THERMOSONIC BONDING

LONG Zhili  WU Yunxin  HAN Lei  DUAN Jian  ZHONG Jue

(College of Electromechanical Engineering, Central South University, Changsha 410083)

Abstract: An impedance and admittance model of transducer system, which includes system features such as material, size, loss factor, resonance frequency, exciting electrical signal and different loads, is established by equivalent circuit method. For two different loads with/without bonding tool, the impedance and admittance of transducer system are calculated based on above model. The numerical computations show that, there are four axial vibration modes of transducer system in 100 kHz. Comparing to no-tool condition, each resonance frequency and its impedance increase when with bonding tool. The result of sweeping measurement by impedance analyzer and FEM model are used to verify the impedance/admittance model.

Key words: Impedance/admittance  Equivalent circuit model  Ultrasonic transducer  Thermosonic bonding

CLC No: TN14

国家自然科学基金(50390064, 50605064)、国家重点基础研究发展计划(973计划,  20073CB716202)、教育部博士点基金(20060533068)和长江学者创新团队发展计划(IRT0549)资助项目. Received 20061206, received in revised form 20070721