航空微电路维修用均匀BAG焊球快速制备研究

为实现航空微电路维修中均匀BAG焊球的小批量快速制备，提出基于均匀微滴喷射技术的均匀焊球快速制备试验研究，重点研究了喷嘴直径、驱动信号脉宽、幅值以及喷射温度对焊球尺寸的影响规律，分析了所制备的均匀焊球的均匀度、球形度以及内部质量。结果表明：喷嘴直径为焊球直径尺寸的强相关参数，驱动信号幅值为显著影响参数、脉宽及喷射温度为无显著影响参数，可结合喷嘴直径与驱动信号幅值进行颗粒尺寸调节；不同直径喷嘴喷射得到的均匀微滴均匀度小于其直径的5%，且焊球球形度较高，金相照片显示焊料颗粒内部组织均匀且致密，满足BGA焊球快速制备的需求，为航空倒装芯片焊球凸点维修用小批量焊球快速制备提供了新方法。

Study on rapid preparation of uniform BAG solder balls for aviation microcircuits maintenance

The present paper studied rapid preparation of uniform BAG solder balls for aviation microcircuit maintenance by utilizing uniform droplet ejection technology. The effects of the nozzle diameter, the driving signal pulse width and amplitude, and the ejection temperature on the solder ball size were studied. The uniformity, sphericity, and internal quality of the prepared solder balls were also analyzed.The results illustrate that the pulse width and spray temperature are no significant influence parameters; The nozzle diameter is a strong correlation parameter of the ball size; The driving signal amplitude is also a significant influence parameter. The particle size can be adjusted according to the nozzle diameter and the driving signal amplitude. The uniformity of solder balls generated from different nozzle sizes is less than 5% of their average diameter, indicating a high spherical degree of the solder balls. Finally, metallographic photos of the solder balls reveal uniform and dense internal structures, This research provides a novel method for rapid preparing uniform solder balls of flip chips in aviation equipment maintenance.