深盲孔电镀铜填充的空洞机理研究  

The void mechanism of copper electroplating filling for high aspect ratio via

作　　者：陆敏菲 朱凯 钟荣军 王蒙蒙 LU Minfei;ZHU Kai;ZHONG Rongjun;WANG Mengmeng(Shennan Circuits Co.,Ltd.,Shenzhen 518117,Guangdong,China)

机构地区：[1]深南电路股份有限公司,广东深圳518117

出　　处：《印制电路信息》2024年第4期20-27,共8页Printed Circuit Information

摘　　要：电镀铜填孔技术被广泛用于高密度互连(HDI)板、封装基板和先进封装中,其中填孔的缺陷和效率问题是目前产业应用过程中最关注的两个方面。重点研究了孔径约110μm、孔深约180μm的深盲孔电镀填孔过程中的空洞问题。首先从理论上分析了填孔过程中镀层生长方式和空洞产生的原因;然后通过哈林槽电镀试验,结合加速剂局部预吸附技术,发现了盲孔底部加速剂和Cu^(2+)传质不足是深盲孔填孔产生空洞的关键原因。研究表明:加速剂局部预吸附技术不仅可以缩短深盲孔电镀填孔时间,而且可以有效地降低深盲孔产生填孔空洞的风险;此外,通过提高气流量、镀液温度或Cu^(2+)浓度来加强深盲孔孔底Cu^(2+)传质对深盲孔填孔是非常必要的。Copper electroplating for via filling is widely used in high density interconnection printed circuit board,IC substrate and advanced package.In the industrial application,defects and efficiency of via filling are the most concerned topics.In this paper,the filling void of via with about 110μm diameter and 180μm depth is investigated in two steps.Firstly,the growth behavior of copper deposition and the potential reasons of void are theoretically discussed.Then,copper electroplating in Harring cell and localized accelerator pre-adsorption process are employed to investigate the void mechanism during via filling.The results show that insufficient mass transfer of accelerator and Cu^(2+)to via bottom is the key factor of via filling void.The localized accelerator pre-adsorption process is beneficial to improving via filling efficiency and reducing void risk.Besides,improvement of Cu^(2+)transfer to via bottom by enhancing cathode air agitation,solution temperature and Cu^(2+)concentration is necessary to avoid via filling void.

关 键 词：电镀铜 盲孔 空洞 加速剂 局部预吸附 

分 类 号：TN41[电子电信—微电子学与固体电子学]