引线键合系统键合工具振动特性研究

研究微电子封装超声引线键合系统键合工具的动态特性和摩擦行为,运用有限单元法建立了键合工具的动态接触模型,初步掌握微电子超声键合系统键合机理。通过对键合工具施加不同的加载频率和正压力的计算结果进行对比,定性地给出了键合过程中加载频率和正压力的变化对键合工具动态响应和摩擦应力的影响.研究结果表明:键合工具的加载频率偏离固有频率,键合工具针尖部分的幅值响应将迅速减小,同时摩擦应力的均值也相对减小;正压力增大,响应幅值将会相应减小;正压力增大到一定值时,幅值响应将会波动比较大,如果要得到适合的键合点尺寸的要求,同时保证键合质量,就必须选择合适的加载频率和正压力。

STUDY ON VIBRATION CHARACTERISTICS OF CAPILLARY IN AN ULTRASONIC WIRE BONDING SYSTEM

Dynamic characteristics of the capillary in an ultrasonic wire bonding system are studied to have a better understanding of the bonding mechanism and further predict the bond quality during the bonding process.With finite element method,a dynamic contact model of the capillary is built,and then various loading frequencies and bonding forces are applied to the model to calculate and simulate the vibration responses and contact friction properties.The result shows that the loading frequency and bonding force have a significant effect on the vibration response and the contact friction stress,and thus on the bond quality.Two conclusions are obtained.Firstly,in order to achieve a good bond quality,appropriate loading frequency and bonding force must be selected.Secondly,the vibration response changes of the capillary can be used as an indicator to evaluate and predict the bond quality.These results can be used as references for the bonding process control and the study on bonding quality detection techniques.