面向毫米波射频互联的超低弧金丝球焊工艺方法研究

Research on Ultra-Low Loop Gold Wire Ball Bonding Technology in Millimeter-Wave RF Interconnection

引线键合工艺是实现毫米波射频(RF)组件互联的关键手段之一。随着毫米波子系统的快速发展,毫米波组件的工作频段越来越高,对射频通道互联金丝的拱高提出了新的要求。过高的引线弧度会使得系统驻波变大,严重影响电路的微波特性。球焊工艺由于引线热影响区的存在,难以满足射频互联中短跨距、低弧高的需求。采用弯折式超低弧弧形工艺,通过对25μm金丝热超声球焊成弧过程中各关键参数的优化试验,将热影响区折叠键合在第一焊点上,在保证引线强度的前提下,实现了300μm短跨距、80μm超低弧高的金丝互联,为球焊工艺在毫米波射频组件互联中的应用提供了实现思路。

The wire bonding process is one of the key means to realize the interconnection of millimeter-wave radio frequency(RF)components.With the rapid development of millimeter-wave subsystems,the working frequency band of millimeter-wave components is getting higher and higher,which puts forward new requirements for the loop height of the interconnection gold wire in the RF channel.Excessive lead radian makes the standing wave of the system larger,which seriously affects the microwave characteristics of circuit.It is difficult to meet the requirements of short span and low loop height in RF interconnection due to the existence of lead heat-affected zone in ball welding process.Through the optimization test of key parameters in the process of thermal ultrasonic ball welding of 25μm gold wire into loop,the heat-affected zone is folded and bonded on the first welding spot.Under the premise of ensuring the strength of the lead wire,the gold wire interconnection with a short span of 300μm and an ultra-low loop height of 80μm is realized.It provides a realization idea for the application of ball welding technology in the interconnection of millimeter-wave RF components.