唐兴勇
,
王珺
,
谷博
,
俞宏坤
,
肖斐
金属学报
对Sn-3.5Ag-0.7Cu/Ni-P界面上的焊点进行了150℃固相老化和250℃液相回流老化实验. 两种条件下焊料体内和界面处金属间化合物的成分、长大速率及形貌均有较大差异. 在液相回流条件下金属间化合物长大更快, 对焊点的可靠性有较大的影响. 延长固相老化时间, 焊点内生成大尺寸的Ag3Sn相; 高温液相回流有Ni3P层生成, 降低焊点的焊接强度.
关键词:
Sn-Ag-Cu焊料
,
Lead-free solder
,
Ni-P
Ning Zhao
材料科学技术（英文）
The wetting property of (Sn-9Zn)-2Cu (wt pct) on Ni substrate and the evolution of interfacial microstructure in (Sn-9Zn)-2Cu/Ni joints during soldering as well as isothermal aging were studied. The wetting ability of eutectic Sn-9Zn solder on Ni substrate was markedly improved by adding 2 wt pct Cu into this solder alloy. Plate-like Cu5Zn8 intermetallic compounds (IMCs) were detected in (Sn-9Zn)-2Cu solder matrix. A continuous Ni5Zn21 IMC layer was formed at (Sn-9Zn)-2Cu/Ni interface after soldering. This IMC layer kept its type and integrality even after aging at 170°C for up to 1000 h. At the early aging stage (before 500 h), the IMC layer grew fast and its thickness followed a linear relationship with the square root of aging time. Thereafter, however, the thickness increased very slowly with longer aging time. When the joints were aged for 1000 h,
a new IMC phase, (Cu,Ni)5Zn8, was found in the matrix near the interface. The formation of (Cu,Ni)5Zn8 phase can be attributed to the di®usion of Ni atoms into the solder matrix from the substrate.
关键词:
Lead-free solder
,
null
,
null
,
null
Haitao MA
,
Haiping XIE
,
Lai WANG
,
null
,
null
材料科学技术（英文）
The microstructure and melting behavior of Sn-9Zn-2Cu (SZC) lead-free solder with 3 wt pct Bi and various amount of Ni additions were studied. The wetting properties and the interfacial reaction of Sn-Zn-Cu with Cu substrate were also examined. The results indicated that the addition of 3 wt pct Bi could decrease the melting point of the solder and Ni would refine the microstructure and the rod-shape Cu5Zn8 phase changed into square-shape (Cu, Ni)5Zn8 phase. The addition of Bi, Ni greatly improved the wettability of SZC solder. In addition, the interfacial phase of the solders/Cu joint was typical planar Cu5Zn8 in SZC-3Bi-1Ni alloy.
关键词:
Lead-free solder
,
null
,
null
,
null
,
null
A.A.El-Daly
材料科学技术（英文）
It is important, for electronic application, to decrease the melting point of Sn-5Sb solder alloy because it is relatively high as compared with the most popular eutectic Pb-Sn solder alloy. Adding Au or Ag can decrease the onset melting temperature (233℃) of this alloy to 203.5℃ and 216℃, respectively. The results indicate that the Sn-5Sb-1.5Au alloy has very good ultimate tensile strength (UTS), ductility, and fusion heat, which are better than both those of the Sn-5Sb-3.5Ag and Sn-5Sb alloys. The formation of intermetallic compounds (IMCs) AuSn4 and Ag3Sn enhanced the microstructure stability, while retained the formation of SbSn precipitates in the solidification microstructure, thus significantly improved the strength and ductility. For all alloys, both UTS and yield stress (σy) increase with increasing strain rate and decrease with increasing temperature in tensile tests, but changes of ductility are generally small with inconsistent trends.
关键词:
Sn-Sb solder
,
null
,
null
,
null
