共查询到20条相似文献,搜索用时 218 毫秒
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作为一种新型低温无铅焊料,Sn-Bi基低温无铅焊料具有较低的熔化温度以及优良的焊接性能,在电子封装领域有着广泛的应用。随着电子元器件向微型化方向的发展,对低温无铅焊料的性能提出了更高的要求。添加微量的合金元素及纳米颗粒可以改善焊料的组织性能,满足电子元器件发展的需求。系统介绍了Sn-Bi基低温无铅焊料的组成、结构以及焊接性能,综述了合金元素和纳米颗粒对Sn-Bi基低温无铅焊料组织性能的影响及作用机理,分析了在研制Sn-Bi基低温无铅焊料过程中存在的不足之处,并提出了相应的改进方法。最后对Sn-Bi基低温无铅焊料在发展中需要关注的问题进行了总结与展望。 相似文献
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相对于传统的Sn-Pb焊料,无铅焊料更容易氧化,润湿性较差,从而影响波峰焊接质量.N2保护可以降低无铅焊料的氧化,提高无铅焊料的润湿性,从而提高波峰焊接质量.从润湿性的机理分析了N2保护提高无铅焊料润湿性的原因,并通过润湿性实验和波峰焊接试验证实了N2保护的优越性. 相似文献
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Dhafer Abdulameer Shnawah Mohd Faizul Mohd Sabri Irfan Anjum Badruddin 《Microelectronics Reliability》2012,52(1):90-99
Currently, the portable electronic products trend to high speed, light weight, miniaturization and multifunctionality. In that field, solder joint reliability in term of both drop impact and thermal cycling loading conditions is a great concern for portable electronic products. The transition to lead-free solder happened to coincide with a dramatic increase in portable electronic products. Sn–Ag–Cu (SAC) is now recognized as the standard lead free solder alloy for packaging interconnects in the electronics industry. The present study reviews the reliability of different Ag-content SAC solder joints in term of both thermal cycling and drop impact from the viewpoints of bulk alloy microstructure and tensile properties. The finding of the study indicates that the best SAC composition for drop impact performance is not necessarily the best composition for optimum thermal cycling reliability. The level of Ag-content in SAC solder alloy can be an advantage or a disadvantage depending on the application, package and reliability requirements. As a result, most component assemblers are using at least two (and in many cases even more) lead-free solder sphere alloys to meet various package requirements. 相似文献
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表面封装用无铅软钎料的接头强度及熔点范围的研究 总被引:6,自引:1,他引:5
研究了Bi的添加量,对电子表面封装(SMT)用Sn-Ag近共晶无铅软钎料钎焊接头抗拉强度和熔点及熔点范围的影响。随着Bi含量的增加,钎焊接头抗拉强度也随着增加,同时钎料的液固相线温度均降低。当Bi的含量达到5%时,抗拉强度增加快;Bi的添加量大于5%时,抗拉强度上升缓慢。在Bi的含量增加时,熔点温度范围也逐渐变宽,使得凝固时间变长,这对于表面组装中的电子元件与器件的焊接是非常不利的。故在Sn-Ag近共晶无铅软钎料中Bi的添加量,应加以适当的控制。 相似文献
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Comparative study of interfacial reactions of Sn-Ag-Cu and Sn-Ag solders on Cu pads during reflow soldering 总被引:1,自引:0,他引:1
The interfacial reaction in soldering is a crucial subject for the solder-joint integrity and reliability in electronic packaging
technology. However, electronic industries are moving toward lead-free alloys because of environmental concerns. This drive
has highlighted the fact that the industry has not yet arrived at a decision for lead-free solders. Among the lead-free alloys,
Sn-3.5Ag and Sn-3.5Ag-0.5Cu are the two potential candidates. Here, detailed microstructural studies were carried out to compare
the interfacial reaction of Sn-3.5Ag and Sn-3.5Ag-0.5Cu solder with a ball grid array (BGA) Cu substrate for different reflow
times. The Cu dissolution from the substrate was observed for different soldering temperatures ranging from 230°C to 250°C,
and the dissolution was found to increase with time and temperature. Dissolution of Cu in the Sn-3.5Ag solder is so fast that,
at 240°C, 12 μm of the Cu substrate is fully consumed within 5 min. Much less dissolution is observed for the Sn-3.5Ag-0.5Cu
solder. In respect to such high dissolution, there is no significant difference observed in the intermetallic compound (IMC)
thickness at the interface for both solder alloys. A simplistic theoretical approach is carried out to find out the amount
of Cu6Sn5 IMCs in the bulk of the solder by the measurement of the Cu consumption from the substrate and the thickness of the IMCs
that form on the interface. 相似文献
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Ken-Ichi Ohguchi Katsuhiko Sasaki Masahiro Ishibashi 《Journal of Electronic Materials》2006,35(1):132-139
A method to separate plasticity and creep is discussed for a quantitative evaluation of the plastic, transient creep, and
steady-state creep deformations of solder alloys. The method of separation employs an elasto-plastic-creep constitutive model
comprised of the sum of the plastic, transient creep, and steady-state creep deformations. The plastic deformation is expressed
by the Ramberg-Osgood law, the steady-state creep deformation by Garofalo’s creep law, and the transient creep deformation
by a model proposed here. A method to estimate the material constants in the elasto-plastic-creep constitutive model is also
proposed. The method of separation of the various deformations is applied to the deformation of the lead-free solder alloy
Sn/3Ag/0.5Cu and the lead-containing solder alloy Sn/37Pb to compare the differences in the plastic, transient creep, and
steady-state creep deformations. The method of separation provides a powerful tool to select the optimum lead-free solder
alloys for solder joints of electronic devices. 相似文献
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