首页|Cu核微焊点液-固界面反应及剪切行为研究

Cu核微焊点液-固界面反应及剪切行为研究

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相较于传统Sn基焊点,Cu核焊点具备更好的导热性、 导电性及力学性能.为揭示尺寸效应对Cu核焊点界面反应及剪切强度的影响,制备了不同Sn镀层厚度的Cu核焊点(Cu@Ni-Sn/Cu).观察回流不同时间后Cu核微焊点横截面微观组织,研究了Cu核微焊点在尺寸效应下的液-固界面反应.之后对Cu核微焊点进行剪切测试,结合断口形貌,分析断裂机理.界面反应结果表明:Cu@Ni-Sn/Cu焊点在250℃回流时,Sn/Ni界面生成Ni含量较高的针状(Cu,Ni)6Sn5 IMC,Sn/Cu界面生成Ni含量较低的层状(Cu,Ni)6Sn5 IMC.剪切测试结果表明:随着Sn镀层厚度增加,Cu@Ni-Sn/Cu焊点的剪切强度先增大后减小.基于Sn镀层厚度对界面(Cu,Ni)6Sn5 IMC层体积的直接影响,Sn层厚度的增加提升了焊点剪切强度.然而Cu@Ni-Sn(60μm)/Cu焊点中Cu核位置的偏移,造成剪切强度略有降低.
Study on liquid-solid interfacial reaction and shear behavior of Cu-cored micro solder joints
In comparison to traditional Sn-based solder joints, Cu-cored solder joints exhibit superior thermal conductivity, electrical conductivity and mechanical properties. To elucidate the size effect on its interfacial reaction and shear strength, Cu-cored solder joints ( Cu@Ni-Sn/Cu) were prepared with different Sn coating thickness. The cross-sectional microstructure were observed after different reflow durations to study the liquid-solid interfacial reaction of the Cu-cored micro solder joints under size effect. Subsequently, shear tests were conducted on the Cu-cored micro solder joints, and the fracture mechanism was analyzed by considering the fracture morphology. The interfacial reaction results indicate that when the Cu@Ni-Sn/Cu solder joints are reflowed at 250 ℃, needle-like (Cu, Ni)6Sn5 IMC with higher Ni content is generated at the Sn/Ni interface, while layered ( Cu, Ni)6Sn5 IMC with lower Ni content is generated at the Sn/Cu interface. The shear test results demonstrate that with increasing Sn coating thickness, the shear strength of Cu@Ni-Sn/Cu joints increases initially and then decreases. Due to the direct influence of the Sn coating thickness on the volume of the ( Cu, Ni)6Sn5 IMC at the interface, thicker Sn layer enhances the shear strength of the solder joint. However, due to the offset of the Cu-core position in Cu@Ni-Sn( 60 μm)/Cu micro solder joints, the shear strength decreases slightly.

electronic packagingCu-cored solder ballliquid-solid interfacial reactionintermetallic compoundshear strength

钱帅丞、陈湜、乔媛媛、赵宁

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大连理工大学 材料科学与工程学院, 辽宁 大连 116024

电子封装 Cu核焊球 液-固界面反应 金属间化合物 剪切强度

国家自然科学基金山东省重点研发计划(重大科技创新工程)辽宁省应用基础研究计划

520750722022CXGC0204082023JH2/101300181

2024

电子元件与材料
中国电子学会 中国电子元件行业协会 国营第715厂(成都宏明电子股份有限公司)

电子元件与材料

CSTPCD北大核心
影响因子:0.491
ISSN:1001-2028
年,卷(期):2024.43(3)
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