{"title":"A Cu-Cu Bonding Method Using Preoxidized Cu Microparticles under Formic Acid Atmosphere","authors":"Runhua Gao, Jiahui Li, Yu-An Shen, H. Nishikawa","doi":"10.23919/ICEP.2019.8733490","DOIUrl":null,"url":null,"abstract":"Many power semiconductor devices now require high tolerance of current density and reliability at high temperature, therefore Cu-Cu bonding using an insert material has raised the level of concerns for its great thermal stability and conductivity. In this study, a low-pressure bonding process was developed to achieve a Cu-Cu bonding using preoxidized Cu microparticles under formic acid atmosphere. The Cu microparticles were preoxidized to generate oxide films and Cu oxide nanostructures, which were then reduced and bonded at 300 °C under formic acid atmosphere to achieve a Cu-Cu bonding. Shear strength of the Cu-Cu bondings were tested to optimize the parameters of bonding process. Fracture surfaces of the Cu-Cu bonding, as well as cross-sectional microstructures, were observed by scanning electrical microscope (SEM) and components were identified by X-ray diffraction (XRD) to investigate the bonding mechanism. The findings reveal that the oxide films and the nanostructures play key roles in this reduction bonding process, which is a promising method to obtain a Cu-Cu bonding satisfying the requirements of power device packaging.","PeriodicalId":213025,"journal":{"name":"2019 International Conference on Electronics Packaging (ICEP)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2019 International Conference on Electronics Packaging (ICEP)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.23919/ICEP.2019.8733490","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 3
Abstract
Many power semiconductor devices now require high tolerance of current density and reliability at high temperature, therefore Cu-Cu bonding using an insert material has raised the level of concerns for its great thermal stability and conductivity. In this study, a low-pressure bonding process was developed to achieve a Cu-Cu bonding using preoxidized Cu microparticles under formic acid atmosphere. The Cu microparticles were preoxidized to generate oxide films and Cu oxide nanostructures, which were then reduced and bonded at 300 °C under formic acid atmosphere to achieve a Cu-Cu bonding. Shear strength of the Cu-Cu bondings were tested to optimize the parameters of bonding process. Fracture surfaces of the Cu-Cu bonding, as well as cross-sectional microstructures, were observed by scanning electrical microscope (SEM) and components were identified by X-ray diffraction (XRD) to investigate the bonding mechanism. The findings reveal that the oxide films and the nanostructures play key roles in this reduction bonding process, which is a promising method to obtain a Cu-Cu bonding satisfying the requirements of power device packaging.