板厚建模对背钻控深精度提升的研究

Study on the improvement of depth control accuracy of back drilling by plate thickness modeling

高厚径比通孔内部经背钻后可构建出有效的信号传输层,但受制于钻孔的精度控制等问题,多余通孔镀铜层则会形成残桩(stub)。因此改善背钻工艺,尽量减小stub的长度成为该工艺的主要研究方向。文章通过对测试板进行大量的板厚测量后建模,根据该模型预测实际的板厚分布,对预设背钻深度进行补偿,最终将stub值控制在50μm~200μm。

An effective signal transmission layer can be constructed by back drilling in the through hole with high thickness diameter ratio,but subject to the accuracy control of drilling,the excess through hole copper plating layer will form a stub.Therefore,improving the back drilling process and minimizing the stub length have become the main research direction of the process.In this paper,plate thickness model is established by measuring plenty of thickness data.The actual plate thickness distribution is predicted through the model,the preset back drilling depth is compensated,and finally the stub value is controlled at 50μm~200μm.