| Microelectronic packaging is the key technology which affects the efficiency and performance of the device in the manufacture of the microelectron. Thermosonic wire bonding is the most important method and technology of the chip Packaging. 90 percents of chips are bonded with thermosonic bonding. The system of the ultrasonic transducer is the key structure of the thermosonic wire bonding equipment, and its performance determines the quality of the chip bonding. The ultrasonic transducer system of wire bonding is designed and the effection of prestress for the transducer back slab and mounting style is found out, the diffusion of the ultrasonic energy in osculant interface is reduced effectively. The main research content is as follows:Firstly, the equivalent circuit is used to piezoelectricity driver of the ultrasonic transducer system, and the analysis method is used to the ultrasonic horn of the ultrasonic transducer system. The physical dimension is gained and the mathematical model of the ultrasonic transducer system is constructed. The finite element analysis is used to certificate the correct of the model, the final structure of the system is determined.Secondly, based on the ANSYS finite element analysis software, the simulation model of the system is established and the modal of the transducer is analyzed. By researching the inherent modal characteristic of the ultrasonic transducer system, the working modal and the fundamental mode of the ultrasonic transducer system are achieved. The influence rule of the vibration modal is gained when the restraint way and the installation site of the mounting style are changedThirdly, the impedance analysis apparatus is used to measure the frequency and resistance, The Doppler vibration measurer is used to measure the vibrational displacement and vibrational velocity. The working performance is researched by changing the prestress of the back slab and mounting style. The optimal prestress of the transducer back slab and mounting style are finded out. Finally, the ultrasonic transducer system is installed in the TS2100 golden bonding equipment, the intensity and surface topography of the wiped joint are checked. After checking, the surface topography is normal, the sheared intensity of first wiped joint is 113.9 gramme and the second is 36.5 gramme. It is proved that the design of the ultrasonic transducer system is successful.All above research contexts, methods and conclusions will be helpful to understand, analyze and design the ultrasonic transducer in IC bonding, and help to improve the semiconductor manufacture in our country. |
