电镀法制备超高密度Cu/Sn凸点和Cu/SnAg凸点及其微观形貌研究  

Fabrication and Microscopic Morphology Investigation of Ultra-high Density Cu/Sn and Cu/SnAg Bump Arrays via Electroplating Technique

作　　者：罗灿琳 林畅 曾煌杰 张永爱[1,2] 孙捷 严群 吴朝兴 郭太良[1,2] 周雄图 LUO Canlin;LIN Chang;ZENG Huangjie;ZHANG Yongai;SUN Jie;YAN Qun;WU Chaoxing;GUO Tailiang;ZHOU Xiongtu(College of Physical and Information Engineering,Fuzhou University,Fuzhou 350108,CHN;Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China,Fuzhou 350108,CHN)

机构地区：[1]福州大学物理与信息工程学院,福州350108 [2]中国福建光电信息科学与技术创新实验室,福州350108

出　　处：《光电子技术》2025年第1期10-17,共8页Optoelectronic Technology

基　　金：国家重点研发计划(2021YFB3600104);闽都创新实验室自主部署项目(2021ZZ130);福建省国家自然科学基金(2021J01577)。

摘　　要：以超高密度Cu/Sn微凸点和Cu/SnAg微凸点为研究对象,采用COMSOL软件建立仿真模型,研究了不同焊料凸点高度对键合可靠性的影响;采用电镀法制备Cu/Sn凸点阵列和Cu/SnAg凸点阵列,重点对界面处金属间化合物(Intermetallic compounds,IMC)进行研究。结果表明,Cu/SnAg凸点高度的增加有利于降低凸点键合界面应力,从而提高芯片键合可靠性。金属凸点尺寸越小,界面处金属间化合物生长越快,空洞数量越多。雾锡凸点的晶粒尺寸大于亮锡凸点,而且晶界数量较少,使得凸点界面上IMC的生长速度较慢。因此,雾锡凸点能够有效减少凸点界面空洞的形成,SnAg合金替代纯锡材料可以进一步减少凸点界面空洞的形成。通过优化工艺条件,成功制备出点间距为8μm,像素阵列为1920×1080的超高密度Cu/SnAg金属凸点。The present study investigatd the ultra-high density Cu/Sn micro-bumps and Cu/SnAg micro-bumps,wherein simulation models were established using COMSOL software to investigate the impact of different solder bump height on bonding reliability.Electroplating was used to prepare Cu/Sn bump arrays and Cu/SnAg bump arrays,and Intermetallic compounds(IMC)at the interface were studied.The results indicated that increasing the height of Cu/SnAg bumps could reduce bonding interface stress and improve chip bonding reliability.Smaller metal bump sizes could lead to faster growth of IMCs and more holes at the interface.Fog tin bumps had larger grain size but fewer grain boundaries than bright tin bumps,resulting in slower growth rate of IMCs at fog tin bumps interfaces.Therefore,fog tin bumps could effectively reduce the formation of interfacial voids,while replacing pure tin material with SnAg alloy could furtherly reduce such voids'formation.By optimizing process conditions,ultra-high density Cu/SnAg metal bumps with a pitch of 8μm and a pixel array of 1920×1080 were successfully prepared.

关 键 词：Cu/Sn凸点 Cu/SnAg凸点 金属间化合物 电镀 

分 类 号：TN405[电子电信—微电子学与固体电子学]