共查询到19条相似文献,搜索用时 156 毫秒
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无铅焊料在清华大学的研究与发展 总被引:2,自引:0,他引:2
清华大学材料科学与工程系电子材料与封装技术研究室研制了6个系列的无铅焊料:Sn-3.5Ag添加Cu或Bi; Sn-3.5Ag-1.0Cu添加In或Bi; Sn-Ag-Cu-In添加Bi; Sn-Ag-Cu添加Ga; Sn-Zn添加Ga; Sn-Zn添加多种元素。重点介绍了Sn-Zn添加多种元素。对6个系列无铅焊料的研究取得了较好的实验结果,得到比较理想的低温焊料体系,有的合金熔点已非常接近铅锡共晶焊料熔点183℃。 相似文献
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稀土改性的Sn-58Bi低温无铅钎料 总被引:1,自引:0,他引:1
研究了微量稀土对Sn-58Bi低温钎料的改性作用.试验添加质量分数为0.1 ?组混合稀土的无铅材料,并对比Sn-58Bi和Sn-58Bi0.5Ag合金.观察了钎料显微组织的变化并做了定量分析,采用DSC测试了钎料的熔化温度,同时测量了钎料的润湿性能、接头强度与硬度.结果表明,微量稀土添加细化了Sn-58Bi钎料合金的显微组织,对钎料的熔化温度几乎没有影响,能显著改善Sn-58Bi钎料的润湿性能和接头剪切强度,而且改善的程度优于添加微量Ag对Sn-58Bi钎料的作用. 相似文献
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《中国无线电电子学文摘》2004,(3)
TN60 2004030494铜锢钊硫对Sn一Ag基无铅焊料性能的影响/林培豪,刘心宇,成钧(桂林电子工业学院)11电子元件与材料‘一2 003,22(10).一33-34研究了Cu、In、Bi、S元素对Sn一Ag基无铅焊料熔点和铺展性的影响.结果表明:Sn一A片Cu三元合金成分为9 5.5%Sn3.5%Agl%Cu时具有较低熔点(215℃)和好的铺展性;加入适量的In可降低Sn一Ag合金的熔点和改善铺展性能;随二(B劝的增加Sn-Ag一Bi三元合金熔点降低、铺展性变好;Sn一Ag合金熔点随、(S)的增加而升高,加入少量S能改善Sn一Ag合金的铺展性.图8参5(刚)影响,发现随着硫酸浓度增加,温度对隧道… 相似文献
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Sn-Sb-Cu(Bi)系无铅钎料的研究 总被引:1,自引:0,他引:1
本文研究了Sn-Sb-Cu(Bi)系无铅钎料的润湿性、显微组织以及熔化特性,对Sb、Cu、Bi等元素在Sn基钎料中的作用进行了阐述,发现了几种有应用潜力的合金,有望取代现有广泛使用的SnAg(Cu)系钎料. 相似文献
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Sn-Zn系无铅钎料最新进展 总被引:1,自引:0,他引:1
Sn-Zn系钎料熔点与传统Sn-37Pb钎料十分接近,成本低廉,被研究者所推崇。由于Zn的存在导致Sn-Zn钎料润湿性差及抗氧化性不足,阻碍了该钎料的发展。添加合金元素和纳米颗粒是改善Sn-Zn钎料组织和性能行之有效的方法之一,为国内外研究者所推崇。结合国内外Sn-Zn系无铅钎料最新研究成果,探讨添加微量的合金元素In、Ni、Cr、Ga、Bi、Cu、Al、Ag、稀土元素及纳米颗粒对钎料润湿性、抗氧化性、力学性能、显微组织和界面组织的影响,同时简述有关钎剂对Sn-Zn的影响,并对Sn-Zn系钎料的发展趋势进行分析与展望。 相似文献
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Sn—Ag—Cu无铅焊料性能研究 总被引:2,自引:0,他引:2
环保和微电子器件高度集成化的发展驱动了高性能无铅焊料的研究和开发,Sn—Ag-Cu系无铅焊料由于具有良好的焊接性能和使用性能,已逐渐成为一种通用电子无铅焊料。文章通过实验的方法,研究了8种不同配比的Sn—Ag—Cu焊料中银、铜含量对合金性能(包括熔点、润湿性和剪切强度)的影响,并对焊料的显微组织进行对比与分析,得出低银焊料的可靠性比高银焊料好,同时Sn-2.9Ag—1.2Cu的合金具有较低的熔点且铺展性好,为确定综合性能最佳的该系焊料合金提供了依据。 相似文献
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本文研究了热处理时间对不同组分的42Sn58Bi-96.5Sn3.5Ag焊料疲劳性能的影响,研究发现适当的热处理时间能提高焊点的机械强度,延长焊点的疲劳寿命。 相似文献
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A mechanical alloying (MA) process was used to produce lead-free solder pastes of Sn-3.5Ag and the Sn-3.5Ag-4Bi system. Because
of the high energy induced by repeated fracturing and welding, the grinding media played an important role during the MA process.
A ceramic container was used to provide stronger impact force, which could induce phase transformation better than a Teflon
container. In addition, it was found that 1-cm balls could fracture Bi particles and promote their dissolution into the Sn
matrix. On the contrary, the milling process tended to achieve homogeneous mixing when using 3-mm balls. The MA powders, after
milling with 3-mm balls, showed a small endothermic peak from the differential scanning calorimetry (DSC) profile at around
138°C, which was the eutectic temperature of Sn-Bi. The melting points of the MA powders in the ceramic container were measured
to be 221°C and 203°C, respectively, for Sn-3.5Ag and Sn-3.5Ag-4Bi from the DSC curves. The reduced melting point ensured
the complete melting during reflow with a peak temperature of 240°C. The formation of Ag3Sn was also observed from the x-ray diffraction peaks, indicating successful alloying by MA. The solder pastes could, thus,
be produced by adding flux into the MA powders. The wetting property of the solder joint was also evaluated. The as-prepared
solder pastes on electroless Ni-P/Cu/Si showed good metallurgical bonding with a contact angle less than 20°. 相似文献
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运用莱卡显微镜、扫描电镜和能谱分析等手段,研究了稀土元素La的添加量对Sn3.5Ag0.5Cu钎料及其与Cu基体焊接后微观组织及性能的影响。结果表明:添加不同含量的稀土La均能使钎料及其与Cu基体焊接后组织与性能得到改善,其中以w(La)达到0.05%时为最优,显微硬度及剪切强度分别提高14%和10.7%。键参数函数计算结果表明La具有"亲Sn"倾向,可细化钎料组织,降低IMC(界面金属间化合物)的长大驱动力。 相似文献
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The early interfacial reaction in the Sn-3.5Ag/Cu soldering system and the system’s premelting behavior were found and characterized
by differential scanning calorimetry incorporated into the reflow process. The results show that the early interfacial reaction
occurs by way of melting and wetting of the solder layer adjacent to the Cu substrate at a temperature nearly 4°C below the
actual melting point of Sn-3.5Ag solder due to solid-state diffusion of Cu atoms into the Sn-3.5Ag binary solder. Consequently,
the early interfacial reaction brings about formation of Cu-Sn intermetallic compounds (IMCs) at a temperature below the melting
point of Sn-3.5Ag, and a prolonged early interfacial reaction can lead to change of the Cu-Sn IMC morphology from planar-like
to scallop-like and promote excessive growth of IMCs at the interface. 相似文献
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Weimin Xiao Yaowu Shi Yongping Lei Zhidong Xia Fu Guo 《Journal of Electronic Materials》2006,35(5):1095-1103
Lead-free solders with excellent material properties and low cost are essential for the electronics industry. It has been
proved that mechanical properties of SnAgCu alloys can be remarkably improved with a minute addition of rare earth (RE) elements.
For comparison and optimization, three valuable solder candidates, Sn3.8Ag0.7Cu0.05RE, Sn3Ag0.5Cu0.05RE, and Sn2.9Ag1.2Cu0.05RE,
were chosen due to the excellent properties of their own SnAgCu basic alloys. Wetting properties, melting temperature, bulk
tensile properties, and joint tensile and shear properties were investigated. In addition, the microstructures of solder joints
were observed and the effects of microstructure on mechanical properties were analyzed. Experimental results indicated that
the tensile and shear strengths of solder joints were decreased from Sn3.8Ag0.7Cu0.05RE, Sn2.9Ag1.2Cu0.05RE, to Sn3Ag0.5Cu0.05RE,
in order. Such difference in mechanical properties could be attributed to the influence of slightly coarse or strong Cu6Sn5 scallops in the reaction layer as well as superior eutectic network and large volume percentage of large primary intermetallic
compounds (IMCs) inside the solder joints. It is also suggested that the size and volume percentage of large primary IMCs
inside the solder be controlled. In addition, serration morphology was observed at the edge of large primary and eutectic
IMCs in the three solder joints, which could be related to the content of Ag, Cu, and RE. The serration morphology was proved
to be beneficial to mechanical properties theoretically. Furthermore, the three alloys investigated possessed similar wetting
properties, melting temperatures, and bulk tensile properties. 相似文献
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Sattiraju S.V. Bing Dang Johnson R.W. Yali Li Smith J.S. Bozack M.J. 《Electronics Packaging Manufacturing, IEEE Transactions on》2002,25(3):168-184
For a successful transition to Pb-free manufacturing in electronics assembly, it is critical to understand the behavior of Pb-free solders (in bulk and paste form) and their interaction with the Pb-free printed wiring board (PWB) finishes. This paper presents the results obtained from solder paste spread tests and wetting balance experiments with several Pb-free solder alloys and Pb-free PWB finishes. The solder alloys studied were Sn3.4Ag4.8Bi, Sn4.0Ag0.5Cu, Sn3.5Ag and Sn0.7Cu. Eutectic Sn37Pb was used as a reference. The PWB surface finishes were Sn, NiAu, Ag and OSP. Wetting balance experiments were conducted in air while the spread tests were performed in air and nitrogen to understand the effect of reflow atmosphere on the spreading. Surface analysis techniques such as Nomarski phase contrast microscopy, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to characterize the as-received PWB finishes. Sequential electrochemical reduction analysis (SERA) was also performed on the as-received PWB test coupons and on the Sn test coupons after multiple reflow cycles. The effect of multiple reflow cycles on the wetting performance, spreading and the surface composition of the PWB finishes was studied. 相似文献