电偶腐蚀对先进封装铜蚀刻工艺的影响  

Influence of Galvanic Corrosion on Copper Etching Process for Advanced Packaging

作　　者：高晓义 陈益钢 GAO Xiaoyi;CHEN Yigang(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;PhiChem Corporation,Shanghai 201908,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]上海飞凯材料科技股份有限公司,上海201908

出　　处：《电子与封装》2023年第11期32-38,共7页Electronics & Packaging

摘　　要：在先进封装的铜种子层湿法蚀刻工艺中,电镀铜镀层的蚀刻存在各向异性的现象。研究结果表明,在磷酸、双氧水的蚀刻液体系中,因电偶腐蚀造成的凸点电镀铜蚀刻量约为铜种子层蚀刻量的4.9倍。通过分析凸点上锡、镍镀层的能谱数据及蚀刻效果,发现该凸点结构中的锡、镍镀层表面存在钝化层,导致锡、镍镀层的蚀刻量远低于铜镀层。在加入不同添加剂的蚀刻液中,通过络合铜或破坏锡、镍镀层表面钝化层的方法,均能达到抑制凸点上铜镀层发生电偶腐蚀的效果。其中,复合型添加剂可以使凸点上铜镀层的横向蚀刻量降低约82%,并且添加剂无残留风险。In the wet etching process of copper seed layer for advanced packaging,there is an anisotropic phenomenon in the etching of electroplated copper coating.The results of the study have been shown that in the etching liquid system of phosphoric acid and hydrogen peroxide,the amount of electroplated copper etching of bumps due to galvanic corrosion is about 4.9 times the amount of copper seed layer etching.By analyzing the energy spectrum data and etching effect of the tin and nickel coatings on the bump,it is found that there are passivation layers on the surface of the tin and nickel coatings in the bump structure,which results in the etching amount of the tin and nickel coatings being much lower than that of the copper coatings.In the etching solutions with different additives,the effect of inhibiting the galvanic corrosion of the copper coatings on the bumps can be achieved by complexing copper or destroying the passivation layers on the surface of the tin and nickel coatings.Among them,the composite additive reduces the amount of transverse etching of the copper coatings on the bumps by about 82%,and there is no risk of residual additives.

关 键 词：种子层 先进封装 铜蚀刻 电偶腐蚀 凸点 

分 类 号：TN305.94[电子电信—物理电子学]