Grain-boundary character and grain growth in bulk tin and bulk lead-free solder alloys
Grain-boundary character and grain growth in bulk tin and bulk lead-free solder alloys
复制标题
DOI：
10.1007/s11664-004-0081-2
复制
发表时间：
2004-12
影响因子：
2.1
通讯作者：
A. Telang;T. Bieler;J. P. Lucas;K. N. Subramanian;L. Lehman;Y. Xing;E. Cotts
中科院分区：
文献类型：
--
作者：
A. Telang;T. Bieler;J. P. Lucas;K. N. Subramanian;L. Lehman;Y. Xing;E. Cotts
晶界变形是焊点的主要破坏形式。了解合金成分变化和冷却速率对显微组织稳定性和变形过程的影响将有助于改进接头的开发。研究了这些变量对纯锡锭和回流试样晶界特性的影响；Sn-3.5wt锭%Ag和Sn-3.8wt.%Ag-0.7wt.%Cu；焊锡球1.63-wt。%或3-wt %Ag。利用取向成像显微镜（OIM）对其微观结构进行了表征。时效（150℃时效200 h）后，两种纯锡试样的细晶多晶组织均显著增长，在晶界处显示出择优取向和边缘形成。合金锭的时效表现为由析出相钉住引起的轻微晶粒长大。焊料球也表现出类似的现象。讨论了合金元素、冷却速率和锡的热膨胀系数各向异性对焊点组织演变、晶界特征和性能的影响。
Grain-boundary deformation is the primary failure mode observed in solder joints. Understanding the effects of alloy composition variations and cooling rates on microstructural stability and deformation processes will allow development of improved joints. The effects of these variables on grain-boundary character were investigated in a pure-tin ingot and a reflowed sample; ingots of Sn-3.5wt.%Ag and Sn-3.8wt.%Ag-0.7wt.%Cu; and solder balls with 1.63-wt.% or 3-wt.%Ag. The microstructure was characterized using orientation imaging microscopy (OIM). After aging (150°C for 200 h), the fine-grained polycrystalline microstructure in both pure-tin specimens grew considerably, revealing preferred misorientations and ledge formation at grain boundaries. Aging of the alloy ingots showed only slight grain growth caused by precipitate pinning. The solder balls showed similar phenomena. The role of alloying elements, cooling rate, and the anisotropy of the coefficient of thermal expansion (CTE) in tin on microstructural evolution, grain-boundary character, and properties of solder joints are discussed.