共查询到18条相似文献,搜索用时 140 毫秒
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Sn基焊料/Cu界面IMC形成机理的研究进展 总被引:1,自引:1,他引:0
锡基无铅焊料和Cu基材界面间容易形成Cu<,6>Sn<,5>、Cu<,3>Sn及其他金属间化合物(IMC),而IMC将剧烈地影响焊接接头的性能,故对其的研究有助于了解IMC形成的本质,从而控制其形成和长大,以改善接头性能.综述了近期的研究结果,指出Cu<,6>Sn<,5>易形成扇贝状,而Cu<,3>Sn常常为薄层状;其... 相似文献
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添加Sn—Ag对Sn—Bi焊接特性的改善 总被引:1,自引:1,他引:0
研究了x42Sn58Bi-(1-x)96。.5Sn3.5Ag系中不同组成的焊料,表明在42Sn58Bi(简称SB)焊料中添加适量的96.5Sn3.5Ag,能改善焊妆温度。通过对焊向拉力的测试分析,发现一的SA能提高焊点的强度并在高低温分别为+125℃和-40℃下进行热冲击1000次后,其强度减不程度远小于纯的SB焊料焊点。其焊点的机械及疲劳性能得到了提高。通过透射X射线及扫描电子显微镜(SEM)分 相似文献
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采用锡铅焊膏粘接的Sn—Ag—Cu BGA元件的焊点可靠性 总被引:1,自引:0,他引:1
《现代表面贴装资讯》2003,(1):20-28
在转向无铅电子产品过程中,元件供应商可能需要支持无铅和合铅元件的双线生产。而这可能合在生产制造中引起广泛的后勤问题。全部使用无铅元件是这个问题的一个解决方法。因此,用锡铅共晶焊膏粘接的Sn-Ag—Cu BGA元件的焊点可靠性需加讨论。在这篇论文中介绍了对两种无铅封装:超细间距BGA(VFBGA)和层叠式CSP(SCSP)的焊点可靠性评估结果,它们是应用锡铅共晶焊膏贴在PCB板上。而这些封装都是采用不同的回流曲线在标准的锡铅组装条件下组装的。采用合保温区或斜升区的热度曲线。回流峰值温度为208℃和222℃。组装后PCB(称为板级)进行温度循环(-40℃—125℃,每个循环30分钟)和落体实验。下面将会详细叙述失效分析。 相似文献
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微量Ni对Sn-3.0Ag-0.5Cu钎料及焊点界面的影响 总被引:2,自引:2,他引:0
研究了Ni的含量对无铅钎料Sn-3.0Ag-0.5Cu润湿性、熔点、重熔及老化条件下界面化合物(IMC)的影响。结果表明:微量Ni的加入使SnAgCu润湿力增加6%;使合金熔点略升高约3℃;重熔时在界面形成了(Cu,Ni)6Sn5IMC层,且IMC厚度远高于SnAgCu/Cu的Cu6Sn5IMC厚度。在150℃老化过程中,SnAgCuNi/Cu重熔焊点IMC随着时间的增加,其增幅小于SnAgCu/Cu的增幅,此时Ni对IMC的增长有一定抑制作用。 相似文献
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微合金化对Sn-9Zn基无铅钎料润湿性能的影响 总被引:9,自引:2,他引:7
熔炼制备了纯的以及含微量Al、Mg、Ti、Bi、重稀土Y、混合轻稀土RE和一种富P非金属活性组元NM的Sn-9Zn基合金,通过测量这些合金以及商用Sn-37Pb焊料在铜基板上的铺展面积比较了它们对铜的润湿性能。结果表明Al、Ti和 Mg不利于提高合金在铜上的润湿性或附着力;Y的改善作用不大;而Bi、RE和NM则能明显改善Sn-9Zn合金对铜的润湿性。在此基础上进一步研究了RE和NM含量对Sn-9Zn润湿性能的影响。以铺展面积衡量,本研究所达到的最佳改善效果使Sn-9Zn合金对铜的润湿性由Sn-37Pb焊料润湿性水平的45.4%提高到了70.3%。 相似文献
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In the current research, trace rare earth (RE) element Y was incorporated into a promising lead-free solder, Sn3.8Ag0.7Cu,
in an effort to improve the comprehensive properties of Sn3.8Ag0.7Cu solder. The range of Y content in Sn3.8Ag0.7Cu solder
alloys varied from 0 wt.% to 1.0 wt.%. As an illustration of the advantage of Y doping, the melting temperature, wettability,
mechanical properties, and microstructures of Sn3.8Ag0.7CuY solder were studied. Trace Y additions had little influence on
the melting behavior, but the solder showed better wettability and mechanical properties, as well as finer microstructures,
than found in Y-free Sn3.8Ag0.7Cu solder. The Sn3.8Ag0.7Cu0.15Y solder alloy exhibited the best comprehensive properties compared
to other solders with different Y content. Furthermore, interfacial and microstructural studies were conducted on Sn3.8Ag0.7Cu0.15Y
solder alloys, and notable changes in microstructure were found compared to the Y-free alloy. The thickness of an intermetallic
compound layer (IML) was decreased during soldering, and the growth of the IML was suppressed during aging. At the same time,
the growth of intermetallic compounds (IMCs) inside the solder was reduced. In particular, some bigger IMC plates were replaced
by fine, granular IMCs. 相似文献
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In this study, the effect of Zn (Zn = 1 wt.%, 3 wt.%, and 7 wt.%) additions to Sn-4Ag solder reacting with Ag substrates was
investigated under solid-state and liquid-state conditions. The composition and microstructure of the intermetallic compounds
(IMCs) significantly changed due to the introduction of different Zn contents. In the case of Sn-4Ag solder with 1 wt.% Zn,
a continuous Ag-Sn IMC layer formed on the Ag substrates; discontinuous Ag-Zn layers and Sn-rich regions formed on the Ag
substrates under liquid-state conditions when the Sn-4Ag solders contained 3 wt.% and 7 wt.% Zn. If 3 wt.% Zn was added to
Sn-4Ag solder, the Ag-Sn IMC would be transformed into a Ag-Zn IMC with increasing aging time. Rough interfaces between the
IMCs and the Ag substrates were observed in Sn-4Ag-7Zn/Ag joints after reflowing at 260°C for 15 min; however, the interfaces
between the IMCs and the Ag substrates became smooth for Sn-4Ag-1Zn/Ag and Sn-4Ag-3Zn/Ag joints. The nonparabolic growth mechanism
of IMCs was probed in the Sn-4Ag-3Zn/Ag joints during liquid-state reaction, and can be attributed to the detachment of IMCs.
On the other hand, the effect of gravity was also taken into account to explain the formation of IMCs at the three different
interfaces (bottom, top, and vertical) during the reflow procedure. 相似文献
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Joule Heating Enhanced Phase Coarsening in Sn37Pb and Sn3.5Ag0.5Cu Solder Joints during Current Stressing 总被引:1,自引:0,他引:1
This paper investigated the effect of Joule heating on the phase coarsening in Sn37Pb and Sn3.5Ag0.5Cu ball grid array (BGA)
solder joints stressed at −5°C and 125°C with a 6.0 × 102 A/cm2 electric current. The phase growth under current stressing was also compared with those under aging at 125°C. It was found
that the current stressing produced a substantial Joule heating in the solder joints and conductive traces. Hence, the solder
joints underwent a considerable temperature rise by 30–35°C when stressed at −5°C and 125°C in this study. Coarsening of Pb-rich
and Ag-rich phases was confirmed to be accelerated by the current stressing as a result of enhanced diffusion at elevated
temperature and atomic stimulation due to numerous collisions between electrons and atoms. Different controlling kinetics
were suggested for the cases stressed or aged at different temperatures. 相似文献
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Yun-Hwan Jo Joo Won Lee Sun-Kyoung Seo Hyuck Mo Lee Hun Han Dong Chun Lee 《Journal of Electronic Materials》2008,37(1):110-117
A combination solder of Sn-3.0Ag-0.5Cu (numbers are all in weight percent unless specified otherwise) wrapped by Sn-57Bi-1Ag
was tested for application to three-dimensional (3-D) multistack packaging. The experimental variables controlled were the
reflow peak temperatures (170, 185, 200, and 230°C), the reflow cycles (up to four times), and the mask which controls the
amount of Sn-57Bi-1Ag solder paste (two sizes). We demonstrate and evaluate the combination solder structure, focusing on
microstructural changes and the shear strength. The degree of mixing in the combination solder, which is enhanced by an increase
in the reflow peak temperature, is independent of the number of reflow cycles. The ball shear strength and the lab shear strength
both increased with increases in the reflow peak temperatures. This behavior is explained by the amount of the brittle Bi
phase that constitutes the eutectic Sn-Bi phase. 相似文献