微孔背钻技术研究

摘要

Simple through hole can bring a negative effect to signal transmission during PCB design. Back drill process reduces excess copper of the through hole, reduces the stub length and capacitive effect, improve the signal transmission quality. With increasing demands on signal integrity, Traditional large diameter, low-precision Back drill process can no longer meet the requirements of Signal integrity, Micro hole back drilling process becoming a trend. Based on the research of micro Hole back drilling technology, control the first plating hole copper thickness, reduce the difficulty of Micro Hole back drilling, solve the key technical problems of hole-filling and low alignment accuracy.%在PCB设计中，看似简单的过孔给信号传输带来很大的负面效应，采用背钻工艺减少通孔中多余的孔壁铜，来减小过孔分支的长度和电容效应，提高信号的传输质量。随着对信号完整性要求越来越高，传统的大孔径和低精度的背钻已经不能满足信号完整性的要求，微孔背钻逐步成为背钻工艺的一个发展趋势。通过对微孔背钻关键工艺进行研究，通过控制一次电镀的孔铜厚度，减少背钻的切削难度，解决了微孔背钻的堵孔和背钻对准度偏差大的关键技术难题。