正反向脉冲电镀在通信背板通孔互连中的应用

Application of periodic pulse reverse plating for through hole interconnection of communication backplane board

通信背板的层数随5G通信技术的不断升级快速增加,板厚也随之增加,导致孔的厚径比越来越高,实现通信背板微小通孔互连的难度越来越大。文章对比了直流电镀和正反向脉冲电镀技术在孔径200μm、厚径比18:1通孔金属化中的效果,设计了正交实验方法对脉冲电镀参数进行了优化,探究了正反向脉冲电镀的电流幅值比、正反向脉冲时间比等关键操作参数对小孔孔壁镀层均匀性的影响,并对镀层进行了可靠性测试。结果表明,正反向脉冲电镀下镀液均镀能力明显优于直流电镀,优化后的脉冲参数使镀液均镀能力达到75%以上,且镀层可靠性也能满足生产品质要求。

With the continuous updating of 5G communication technology,the layer number of communication backplane board has been increased rapidly,and the thickness of the boards has also been increased.However,the through hole(TH)diameter has been continuously reduced due to the improvement of the backplane integration,resulting in higher TH aspect ratio.In this paper,the DC plating and periodic pulse reverse(PPR)plating techniques were compared for the effects of TH metallization with a diameter of 200μm and an aspect ratio of 18:1.The Orthogonal experimental design method was employed to optimize the pulse electrodeposition parameters,and the influence of key operating parameters such as the current amplitude ratio of PPR plating and the forward and reverse pulse time ratio on the uniformity coating of the hole center was investigated.And the reliability of the coating was tested.In addition,the throwing power(TP)of the electrolyte with PPR plating is significantly better than that of DC electrodeposition.The TPs of PPR plating is higher than 75%with the optimized pulse parameters,and the reliability of the coating also meets the requirement of production quality.