共查询到17条相似文献,搜索用时 187 毫秒
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无铅电子钎料合金蠕变性能研究 总被引:7,自引:0,他引:7
设计制作了一种简单可靠的弯折蠕变测量装置,比较了两种无铅电子钎料合金Sn-9Zn和Sn-3.5Cu-0.7Ag与传统电子钎料合金Sn-40Pb的常温蠕变性能,以及冷却条件对其蠕变强度的影响。结果表明:两种无铅钎料的抗蠕变性能大大优于传统锡铅钎料;Sn-3.5Ag-0.7Cu合金的抗蠕变性能优于Sn-9Zn合金;冷却速率对Sn-9Zn合金和Sn-3.5Ag-0.7Cu合金组织的影响类似,然而对蠕变强度的影响却相反:水冷使两种合金的组织相对于空冷都明显细化,Sn-9Zn合金的蠕变强度因之降低,而Sn-3.5Ag-0.7Cu合金的蠕变强度却因之提高。对可能产生的原因进行了讨论。 相似文献
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《电子元件与材料》2017,(11):60-67
通过扫描电镜(SEM)等手段研究了Sn-9Zn/Cu在不同浸焊时间与时效时间等条件下的界面反应及其金属间化合物(IMC)生长行为。结果表明:在浸焊后,Sn-9Zn/Cu钎焊接头界面形成了扇贝状的界面化合物Cu5Zn8,IMC层厚度随着浸焊时间与时效处理时间的增加而增加,未时效处理的焊点界面IMC与铜基板接触的一面较为平直,而与钎料接触的一侧呈现出锯齿状,随着时效时间的增加,界面变得越来越不平整;另外在IMC层与焊料之间产生裂缝现象,分析认为是由于钎料与IMC之间的热膨胀系数差异导致热应力形成裂缝。浸焊600 s后的试样在时效15 d后IMC层与Cu基板接触侧产生了与初始金属间化合物Cu5Zn8不同的三元化合物Cu6(Sn,Zn)5。 相似文献
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采用铺展面积法研究了Sn-3.0Ag-0.5Cu无铅钎料在不同温度下的润湿性能,同时探讨了150℃等温时效对Sn-3.0Ag-0.5Cu/Cu焊点界面组织及力学性能的影响。结果表明,随着钎焊温度的升高,Sn-3.0Ag-0.5Cu钎料的润湿性能明显增加。焊后钎料/Cu界面处对应的金属间化合物为Cu6Sn5相,经150℃时效,界面层的形貌由原来的齿状逐渐转化为层状,且厚度随着时效时间的增加而增加。发现界面层金属间化合物厚度与时效时间的二次方根成线性关系。对焊点在时效过程中的力学性能进行分析,发现Sn3.0Ag0.5Cu/Cu焊点的力学性能随着时效时间的增加逐渐降低,时效初期,焊点的力学性能下降较快,后期趋于平缓。 相似文献
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Ce对SnAgCu系无铅焊锡力学性能的影响 总被引:6,自引:0,他引:6
通过向Sn-3Ag-2.8Cu钎料合金中添加微量稀土Ce,利用扫描电子显微镜(SEM)研究了不同稀土含量对Sn-3Ag-2.8Cu合金的力学性能的影响,同时对显微组织进行了分析.实验结果表明,微量的Ce稀土可以显著提高Sn-3Ag-2.8Cu钎料的延伸率、延长其焊接接头在室温下的蠕变断裂寿命,尤其是当稀土的质量分数为0.1%时,其蠕变断裂寿命可以达到Sn-3Ag-2.8Cu钎料的9倍以上,当稀土的质量分数超过0.1%时,接头的蠕变断裂寿命呈下降趋势.综合考虑,最佳的稀土质量分数为0.05%~0.10%. 相似文献
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Sn-9Zn/Cu焊点的结合强度与抗蠕变性能 总被引:1,自引:0,他引:1
基于前期进行的锡锌合金无铅钎料新型助焊剂研究,实验考查了其中二氯化锡活化剂含量水平对Sn-9Zn/Cu焊点剪切强度和常温抗剪切蠕变性能的影响.结果表明:就上述焊点强度而言,二氯化锡含量的影响与它对润湿性的影响[5]不尽一致,存在一个最佳的质量分数5%,超过该含量后尽管润湿性还继续提高,上述强度值却均会下降.在二氯化锡质量分数为5%时制得的焊点在剪切实验中呈良好韧性断裂模式.实验还显示:焊剂中较高的松香浓度明显有益于焊点的抗剪切蠕变强度,而对瞬时剪切强度影响不大. 相似文献
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回流焊对SnAgCu焊点IMC及剪切强度的影响 总被引:1,自引:1,他引:0
研究了回流焊次数对Sn-0.3Ag-0.7Cu-xNi/Cu(x=0,0.05)焊点的界面反应及其剪切强度的影响。结果表明:随着回流焊次数的增加,界面金属间化合物(IMC)Cu6Sn5和(Cu1-xNix)6Sn5的厚度均增加。在钎料中添加w(Ni)为0.05%,可有效抑制IMC的生长,与回流焊次数无关。回流焊次数对Sn-0.3Ag-0.7Cu/Cu和Sn-0.3Ag-0.7Cu-0.05Ni/Cu的剪切强度影响都不大,五次回流焊后剪切强度略有下降,剪切强度分别为21MPa和25MPa。发现断裂面部分在钎料中,部分在钎料和IMC之间。 相似文献
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In general, formation and growth of intermetallic compounds (IMCs) play a major role in the reliability of the solder joint
in electronics packaging and assembly. The formation of Cu-Sn or Ni-Sn IMCs have been observed at the interface of Sn-rich
solders reacted with Cu or Ni substrates. In this study, a nanoindentation technique was employed to investigate nanohardness
and reduced elastic moduli of Cu6Sn5, Cu3Sn, and Ni3Sn4 IMCs in the solder joints. The Sn-3.5Ag and Sn-37Pb solder pastes were placed on a Cu/Ti/Si substrate and Ni foil then annealed
at 240°C to fabricate solder joints. In Sn-3.5Ag joints, the magnitude of the hardness of the IMCs was in the order Ni3Sn4>Cu6Sn5>Cu3Sn, and the elastic moduli of Cu6Sn5, Cu3Sn, and Ni3Sn4 were 125 GPa, 136 GPa, and 142 GPa, respectively. In addition, the elastic modulus of the Cu6Sn5 IMC in the Sn-37Pb joint was similar to that for the bulk Cu6Sn5 specimen but less than that in the Sn-3.5Ag joint. This might be attributed to the strengthening effect of the dissolved
Ag atoms in the Cu6Sn5 IMC to enhance the elastic modulus in the Sn-3.5Ag/Cu joint. 相似文献
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The lead-free SnAgCu (SAC) solder joint on copper pad with organic solderability preservative (Cu-OSP) and electroless nickel
and immersion gold (ENIG) subjected to thermal testing leads to intermetallic growth. It causes corresponding reliability
concerns at the interface. Nanoindentation characterization on SnAgCu solder alloy, intermetallic compounds (IMCs), and the
substrates subjected to thermal aging is reported. The modulus and hardness of thin IMC layers were measured by nanoindentation
continuous stiffness measurement (CSM) from planar IMC surface. When SAC/Ni(Au) solder joints were subject to thermal aging,
the Young’s modulus of the NiCuSn IMC at the SAC/ENIG specimen changed from 207 GPa to 146 GPa with different aging times
up to 500 h. The hardness decreased from 10.0 GPa to 7.3 GPa. For the SAC/Cu-OSP reaction couple, the Young’s modulus of Cu6Sn5 stayed constant at 97.0 GPa and hardness about 5.7 GPa. Electron-probe microanalysis (EPMA) was used to thermal aging. The
creep effect on the measured result was analyzed when measuring SnAgCu solder; it was found that the indentation penetration,
and thus the hardness, is loading rate dependent. With the proposed constant P/P experiment, a constant indentation strain
rate h/h and hardness could be achieved. The log-log plot of indentation strain rate versus hardness for the data from the
constant P/P experiments yields a slope of 7.52. With the optimized test method and CSM Technique, the Modulus of SAC387 solder
alloy and all the layers in a solder joint were investigated. 相似文献
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Mechanical properties of intermetallic compound (IMC) phases in Pb-free solder joints were obtained using nanoindentation
testing (NIT). The elastic modulus and hardness were determined for IMC phases associated with insitu FeSn particle reinforced
and mechanically added, Cu particle-reinforced, composite solder joints. The IMC layers that formed around Cu particle reinforcement
and at the Cu substrate/solder matrix interface were probed with NIT. Moduli and hardness values obtained by NIT revealed
were noticeably higher for Cu-rich Cu3Sn than those of Cu6Sn5. The Ag3Sn platelets that formed during reflow were also examined for eutectic Sn-Ag solder column joints. The indentation modulus
of Ag3Sn platelets was significantly lower than that of FeSn, SnCuNi, and CuSn IMCs. Indentation creep properties were assessed
in localized microstructure regions of the as-cast, eutectic Sn-Ag solder. The stress exponent, n, associated with secondary
creep differed widely depending on the microstructure feature probed by the indenter tip. 相似文献
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Effect of Cr additions on interfacial reaction between the Sn-Zn-Bi solder and Cu/electroplated Ni substrates 总被引:2,自引:0,他引:2
Intermetallic compounds (IMCs) growth on the Sn-8Zn-3Bi (-Cr) solder joints with Cu and electroplated Ni substrates was investigated after aging at 150 °C. It was found that the IMCs were the Cu5Zn8 and Ni5Zn21 at the solder/Cu and solder/Ni interface, respectively. The IMCs growth rate at the Sn-8Zn-3Bi-Cr/Cu and Ni interface was slower than that at Sn-8Zn-3Bi/Cu interface (about 1/2 times) and Sn-8Zn-3Bi/Ni interface (about 1/4 times) during aging. The reason may be that Cr reacts with Zn and forms the Sn-Zn-Cr phase which block the diffusion of Zn atom to the interface and slow down the IMCs growth rate. 相似文献
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Taehoon You Yunsung Kim Jina Kim Jaehong Lee Byungwook Jung Jungtak Moon Heeman Choe 《Journal of Electronic Materials》2009,38(3):410-414
Despite being expensive and time consuming, board-level drop testing has been widely used to assess the drop or impact resistance
of the solder joints in handheld microelectronic devices, such as cellphones and personal digital assistants (PDAs). In this
study, a new test method, which is much simpler and quicker, is proposed. The method involves evaluating the elastic strain
energy and relating it to the impact resistance of the solder joint by considering the Young’s modulus of the bulk solder
and the fracture stress of the solder joint during a ball pull test at high strain rates. The results show that solder joints
can be ranked in order of descending elastic strain energy as follows: Sn-37Pb, Sn-1Ag-0.5Cu, Sn-3Ag-0.5Cu, and Sn-4Ag-0.5Cu.
This order is consistent with the actual drop performances of the samples. 相似文献
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The effect of Ag content on the wetting behavior of Sn-9Zn-xAg on aluminum and copper substrates during soldering, as well as the mechanical properties and electrochemical corrosion
behavior of Al/Sn-9Zn-xAg/Cu solder joints, were investigated in the present work. Tiny Zn and coarsened dendritic AgZn3 regions were distributed in the Sn matrix in the bulk Sn-9Zn-xAg solders, and the amount of Zn decreased while that of AgZn3 increased with increasing Ag content. The wettability of Sn-9Zn-1.5Ag solder on Cu substrate was better than those of the
other Sn-9Zn-xAg solders but worse than that of Sn-9Zn solder. The wettability of Sn-9Zn-1.5Ag on the Al substrate was also better than
those of the other Sn-9Zn-xAg solders, and even better than that of Sn-9Zn solder. The Al/Sn-9Zn/Cu joint had the highest shear strength, and the shear
strength of the Al/Sn-9Zn-xAg/Cu (x = 0 wt.% to 3 wt.%) joints gradually decreased with increasing Ag content. The corrosion resistance of the Sn-9Zn-xAg solders in Al/Sn-9Zn-xAg/Cu joints in 5% NaCl solution was improved compared with that of Sn-9Zn. The corrosion potential of Sn-9Zn-xAg solders continuously increased with increasing Ag content from 0 wt.% to 2 wt.% but then decreased for Sn-9Zn-3Ag. The
addition of Ag resulted in the formation of the AgZn3 phase and in a reduction of the amount of the eutectic Zn phase in the solder matrix; therefore, the corrosion resistance
of the Al/Sn-9Zn-xAg/Cu joints was improved. 相似文献
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We developed a new lead-free solder alloy, an Sn-Ag-Cu base to which a small amount of Ni and Ge is added, to improve the
mechanical properties of solder alloys. We examined creep deformation in bulk and through-hole (TH)␣form for two lead-free
solder alloys, Sn-3.5Ag-0.5Cu-Ni-Ge and Sn-3.0Ag-0.5Cu, at elevated temperatures, finding that the creep rupture life of the
Sn-3.5Ag-0.5Cu-Ni-Ge solder alloy was over three times better than that of the Sn-3.0Ag-0.5Cu solder at 398 K. Adding Ni to
the solder appears to make microstructural development finer and more uniform. The Ni added to the solder readily combined
with Cu to form stable intermetallic compounds of (Cu, Ni)6Sn5 capable of improving the creep behavior of solder alloys. Moreover, microstructural characterization based on transmission
electron microscopy analyses observing creep behavior in detail showed that such particles in the Sn-3.5Ag-0.5Cu-Ni-Ge solder
alloy prevent dislocation and movement. 相似文献