共查询到18条相似文献,搜索用时 78 毫秒
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Sn-Ag系电子无铅软钎料的超电势研究 总被引:3,自引:0,他引:3
随着微电子表面组装技术(SMT)的迅速发展和公众环境意识的增强,无铅软钎料成为近年来研究的焦点。主要研究了Sn-Ag系合金钎料的超电势电化学性能,并且与传统的Sn-Pb近共晶合金进行了对比。试验证明在酸、碱两种不同的溶液环境中,无铅软钎料在Sn-Pb合金的超电势有明显的差异。并指出含铋的钎料的超电势随着铋的含量的增加而降低,从而提出了在无铅软钎料研究中应当考虑因超电势变化而引起的问题。 相似文献
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Ag对Sn-9Zn合金钎料组织及性能的影响 总被引:3,自引:0,他引:3
用莱卡显微镜、XRD研究添加元素Ag对Sn-9Zn钎料组织及性能的影响。结果表明:Ag与Zn形成AgZn3化合物,能抑制粗大针状富Zn相的形成,可使Sn-9Zn钎料合金的润湿性提高20%,并明显改善Sn-9Zn的耐蚀性。 相似文献
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研制开发熔点在260 ℃以上的高温无铅钎料来代替传统的高铅钎料运用于电子封装一直是钎焊领域的一大难题。熔点约为272 ℃的Bi-2.6 Ag-5 Sb钎料合金因润湿性和焊接可靠性不良在运用上受到限制。文中通过在Bi-2.6 Ag-5 Sb钎料合金中添加微量元素Cu来改善B-i2.6 Ag-5 Sb合金的润湿性及焊接可靠性。研究结果表明,Cu含量对BiAgSbCu系钎料合金熔点影响较小,当Cu含量为2 %时,润湿性及焊接可靠性最佳。 相似文献
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以Sn2.5Ag0.7Cu为基础,添加微量的稀土(RE)r(Ce︰La)为4︰1,研究了钎焊接头的显微组织与力学性能。结果表明:添加微量的RE后,钎料与Cu试样间的界面层厚度明显减小,且界面处的组织更加平滑,相应地其剪切强度随微量RE的添加而增大,并在RE含量(质量分数)为0.1%时达到最大值36MPa。 相似文献
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Formation and growth of intermetallics around metallic particles in eutectic Sn-Ag solder 总被引:2,自引:0,他引:2
Incorporation of metallic particulate reinforcements in eutectic Sn-Ag solder results in the formation of intermetallic compounds
(IMCs) along particulate/solder interfaces with different morphologies. For instance, “sunflower” and “blocky faceted” IMC
shapes have been observed around Ni particle reinforcements incorporated in the eutectic Sn-Ag solder matrix. The time and
temperature above solder liquidus during the heating stage of the reflow process has been found to play a significant role
in determining the IMC morphology in these Ni particulate-reinforced solders. Similar studies were carried out with Cu and
Ag particulate reinforcements using the same solder matrix. The amount of heat input caused no significant change in morphology
of the IMCs formed around Cu and Ag particulate reinforcements. Also, the IMC morphology around Ni particles was sensitive
to the Cu content in the solder, whether the Cu came from the substrate during reflow or it was already present within the
solder. 相似文献
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Hwa-Teng Lee Ming-Hung Chen Huei-Mei Jao Chin-Jui Hsu 《Journal of Electronic Materials》2004,33(9):1048-1054
This study investigates the influence of adding Sb on the microstructure and adhesive strength of the Sn3.5Ag solder. Both
solidus and liquidus temperatures increase as Sb additions increase. Adding 1.5wt.%Sb leads to the narrowest range (6.6°C)
between the solidus and liquidus temperature of the solder. Adding Sb decomposes the as-soldered ringlike microstructure of
Sn3.5Ag and causes solid-solution hardening. The as-soldered hardness increases with increasing Sb addition. For long-term
storage, adding Sb reduces the size of the rodlike Ag3Sn compounds. The hardness also increases with increasing Sb addition. Adding Sb depresses the growth rate of interfacial
intermetallic compounds (IMCs) layers, but the difference between 1% and 2% Sb is not distinct. For mechanical concern, adding
Sb improves both adhesive strength and thermal resistance of Sn3.5Ag, where 1.5% Sb has the best result. However, adding Sb
causes a variation in adhesive strength during thermal storage. The more Sb is added, the higher the variation reveals, and
the shorter the storage time requires. This strength variation helps the solder joints to resist thermal storage. 相似文献
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Addressing the potential for drop impact failure of Pb-free interconnects, the shear ductility after extensive aging of Sn-Ag-Cu
(SAC) solders has been improved radically by Co or Fe modifications. Several other SAC+X candidates (X=Mn, Ni, Ge, Ti, Si,
Cr, and Zn) now have been tested. Solder joint microstructures and shear strength results show that new SAC+X alloys also
suppress void formation and coalescence at the Cu (substrate)/Cu3Sn interface (and embrittlement) after aging at 150°C for up to 1,000 h. Microprobe measurements of 1,000 h aged samples suggest
that Cu substitution by X is usually accentuated in the intermetallic layers, consistent with X=Co and Fe results. 相似文献
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The effect of soldering process variables on the microstructure and mechanical properties of eutectic Sn-Ag/Cu solder joints 总被引:2,自引:0,他引:2
Wenge Yang Lawrence E. Felton Robert W. Messler 《Journal of Electronic Materials》1995,24(10):1465-1472
Fundamental understanding of the relationship among process, microstructure, and mechanical properties is essential to solder
alloy design, soldering process development, and joint reliability prediction and optimization. This research focused on the
process-structure-property relationship in eutectic Sn-Ag/Cu solder joints. As a Pb-free alternative, eutectic Sn-Ag solder
offers enhanced mechanical properties, good wettability on Cu and Cu alloys, and the potential for a broader range of application
compared to eutectic Sn-Pb solder. The relationship between soldering process parameters (soldering temperature, reflow time,
and cooling rate) and joint microstructure was studied systemati-cally. Microhardness, tensile shear strength, and shear creep
strength were measured and the relationship between the joint microstructures and mechani-cal properties was determined. Based
on these results, low soldering tempera-tures, fast cooling rates, and short reflow times are suggested for producing joints
with the best shear strength, ductility, and creep resistance. 相似文献
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The shear strength behavior and microstructural effects after aging for 100 h and 1,000 h at 150°C are reported for near-eutectic
Sn-Ag-Cu (SAC) solder joints (joining to Cu) made from Sn-3.5Ag (wt.%) and a set of SAC alloys (including Co- and Fe-modified
SAC alloys). All joints in the as-soldered and 100-h aged condition experienced shear failure in a ductile manner by either
uniform shear of the solder matrix (in the strongest solders) or by a more localized shear of the solder matrix adjacent to
the Cu6Sn5 interfacial layer, consistent with other observations. After 1,000 h of aging, a level of embrittlement of the Cu3Sn/Cu interface can be detected in some solder joints made with all of the SAC alloys and with Sn-3.5Ag, which can lead to
partial debonding during shear testing. However, only ductile failure was observed in all solder joints made from the Co-
and Fe-modified SAC alloys after aging for 1,000 h. Thus, the strategy of modifying a strong (high Cu content) SAC solder
alloy with a substitutional alloy addition for Cu seems to be effective for producing a solder joint that retains both strength
and ductility for extended isothermal aging at high temperatures. 相似文献
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S. Choi J. G. Lee K. N. Subramanian J. P. Lucas T. R. Bieler 《Journal of Electronic Materials》2002,31(4):292-297
Sn-Ag based solder joints of 100-μm thickness were thermomechanically fatigued between −15°C and +150°C with a ramp rate of
25°C/min for the heating segment and 7°C/min for the cooling segment. The hold times were 20 min at high temperature extreme
and 300 min at the low temperature extreme. Surface damage accumulation predominantly consisted of shear banding, surface
relief due to Sn-grain extrusion, grain boundary sliding, and grain decohesion usually near the solder/substrate interface.
Small alloy additions were found to affect the extent of this surface damage accumulation. 相似文献
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Copper substrate dissolution in eutectic Sn-Ag solder and its effect on microstructure 总被引:3,自引:0,他引:3
S. Chada R. A. Fournelle W. Laub D. Shangguan 《Journal of Electronic Materials》2000,29(10):1214-1221
The dissolution of Cu into molten Sn-3.8at.%Ag (Sn-3.5wt.%Ag) solder and its effect on microstructure were studied by light
microscopy, scanning microscopy, and x-ray microanalysis. X-ray microanalysis of the average Cu content of samples soldered
under various conditions showed that the amount of Cu dissolved during soldering increased with increasing soldering temperature
and time and that the rate of dissolution could be described by a Nernst-Brunner equation. Microstructurally it was found
that the volume fractions of primary β(Sn) dendrites and η-phase dendrites increase with increasing soldering temperature
and time. The microstructural changes can be explained using Sn-Ag-Cu phase equilibrium data. A numerical method was developed
for calculating the amount of Cu dissolved under non-isothermal conditions, which describes dissolution reasonably well. 相似文献