亚微米银焊膏的低温无压烧结性能研究  

Low-Temperature Pressureless Sintering Properties of Submicron Silver Pastes

作　　者：李欣[1] 汪智威 Li Xin;Wang Zhiwei(School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学材料科学与工程学院,天津300350

出　　处：《天津大学学报（自然科学与工程技术版）》2024年第9期974-981,共8页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(51401145).

摘　　要：烧结银焊膏具备高导热、高导电、低弹性模量和高可靠性等优异性能,可以最大程度地发挥出SiC和GaN器件的潜能,因此具有广阔的应用前景.为了降低银焊膏的制备成本,同时改善银焊膏的烧结性能,使用球形和片状两种亚微米银颗粒制备了3种烧结银焊膏,通过分析银焊膏在200~250℃低温无压烧结后的电阻率、剪切强度和微观形貌,研究了不同形貌亚微米银颗粒及混合颗粒的低温无压烧结性能.研究表明:球形银颗粒制备的银焊膏在250℃烧结后,具有52.4 MPa的高剪切强度,同时其电阻率仅为6.28×10^(-8)Ω·m;银片制备的银焊膏烧结后的剪切强度始终较低且电阻率始终较大,在250℃烧结后,剪切强度为21.5 MPa,电阻率为15.54×10^(-8)Ω·m,这归因于银片的径向尺寸较大、振实密度较低和银片层层堆叠的烧结结构;混合颗粒的银焊膏展现出了在更低温度下烧结的潜力,在200℃烧结后,剪切强度为28.2 MPa,电阻率为7.77×10^(-8)Ω·m,这得益于银片可促进所选有机组分更早地去除和混合颗粒具有更高的初始堆积密度.本文研究成果有助于亚微米银颗粒焊膏的成熟稳定制备,也为低温无压烧结的高性能银焊膏的研发提供了新的思路.Sintered silver pastes show excellent properties such as high thermal conductivity,high electrical conductivity,low elastic modulus,and high reliability,allowing them to maximize the potential of SiC and GaN devices;thus,these pastes have broad application prospects.To reduce the preparation cost and improve the sintering performance of the silver pastes,three types of sintered silver pastes were prepared using two types of submicron silver particles:spherical and flaky.The sintering properties of submicron silver particles with different morphologies and mixed particles were examined by analyzing the electrical resistivity,shear strength,and microscopic morphology of the silver pastes sintered at 200—250℃without pressure.The silver paste prepared from spherical silver particles showed a high shear strength of 52.4 MPa after sintering at 250℃,and its electrical resistivity was only 6.28×10^(-8)Ω·m.The silver paste prepared from silver flakes showed a low shear strength and high electrical resistivity after sintering.When the silver paste prepared from silver flakes was sintered at 250℃,the shear strength was 21.5MPa,and the electrical resistivity was 15.54×10^(-8)Ω·m,which was attributed to the large radial size of the silver flakes,low tap density,and sintering structure of the silver flakes stacked in layers.The silver paste with mixed particles showed potential for sintering at 200℃,with a shear strength of 28.2 MPa and electrical resistivity of 7.77×10^(-8)Ω·m,which was attributed to the silver flakes.The submicron silver flakes promoted faster evaporation of the selected organic components and a higher initial packing density of the mixed particles.These results contrib2024 uted to the mature and stable preparation of submicron silver pastes and provided a new approach for developing highperformance silver pastes with low-temperature pressure-less sintering properties.

关 键 词：低温无压烧结 亚微米银颗粒 银片 芯片连接 

分 类 号：TG425[金属学及工艺—焊接]