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在Sn-0.7Cu-0.1Ag低银焊料基础上进行微合金化,研究了Ag和Ni对钎料润湿性以及元素X对钎料润湿抗氧化性的影响,比较了超声波雾化法与气体雾化法制备焊锡粉的区别.结果表明:随着Ag含量增加,钎料合金的润湿力提高并且润湿时间减少.添加Ni元素,钎料润湿力并没有明显变化,润湿时间略有减小.高活性焊剂可以显著提高钎料润湿力,同时缩短润湿时间.在低银钎料中添加微量元素X,质量分数超过0.003%时,可以显著改善钎料抗氧化性能.采用超声波雾化法较气体雾化法制得的低银焊锡粉,异形粉比例明显下降. 相似文献
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为了提高Sn9Zn共晶钎料的钎焊性能,通过合金化的方法添加了少量元素In,制备了Sn9Zn-xIn钎料。从钎料合金的熔化特性、润湿特性、界面显微结构和母材粗糙度这四个方面评价了不同In含量对Sn9Zn钎料润湿性能的影响。试验结果表明:少量元素In的添加可以降低钎料的熔点;随着In含量的增加,钎料的润湿力增大,润湿时间缩短,润湿性有明显提高;In含量增加,润湿界面层中Cu5Zn8化合物层厚度增加;对母材表面进行毛化处理,通过改变母材表面的微观几何结构,增大钎料与母材的相对接触面积,从而改善钎料的润湿性能。 相似文献
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本文讨论汽相再流钎焊时针料的润湿和铺展。以润湿测力法和铺展面积法首次研究了“FC70—松香—6OSn/40Ph钎料—铜”润湿系统中钎料的润湿过程,FC70对钎料润湿速度、程度的影响,并直接研究了松香排开FC70润湿铜的过程。研究认为FC70在一定程度上妨碍钎剂和钎料的润湿铺展,并分析而由此造成的利弊。文中还以氧化膜颜色法和测量润湿力检查了FC70汽相气氛的不氧化特性。 相似文献
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合金元素对Sn-Zn基无铅钎料高温抗氧化性的影响 总被引:15,自引:12,他引:15
研究了不同微量合金元素对Sn-Zn基无铅钎料高温抗氧化性的影响。钎料在液态下的表面颜色变化以及热重分析表明,Al、Cr能明显改善Sn-Zn基钎料的抗氧化性能。通过俄歇能谱深度剖析和X射线衍射分析探讨了合金元素的抗氧化机理:Al和Cr在钎料表面或亚表面富集,形成阻挡层,抑制了钎料的氧化。比较了合金元素对Sn-Zn基钎料润湿性能的影响,结果表明Al的加入不利于钎料的铺展。通过实验得出结论:Cr是一种比Al更具有吸引力的Sn-Zn基钎料的高温抗氧化合金元素。 相似文献
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采用悬滴法测量了3种无铅钎料合金(Sn-3.0Ag-0.5Cu、Sn-0.7Cu与Sn-9.0Zn)在260℃时的表面张力,分别为525.5,534.8和595.4 mN/m;同时采用座滴法测量了其在260℃熔融状态下与Cu基板的接触角,分别为24.5°、28.0°和102.5°,并且与传统Sn-37.0Pb钎料进行了比较研究。结果表明,无铅钎料合金的表面张力与接触角均大于Sn-37.0Pb钎料。结合Young-Dupre公式讨论了钎料合金表面张力与其润湿性能的相关性,认为Sn基钎料合金在Cu基板上的润湿性能主要取决于其表面张力。 相似文献
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Jicun Lu Busch S.C. Baldwin D.F. 《Electronics Packaging Manufacturing, IEEE Transactions on》2001,24(3):154-159
Wafer-level flip chips provide an innovative solution in establishing flip chip as a standard surface mount process. In this paper, the wetting of solder bumps within confining underfill during the reflow of a wafer-level flip chip assembly is addressed. For real time monitoring of an assembly during the reflow process, a system using a high-speed camera is utilized. The collapse of solder bumps on the chip in the vertical direction is found to be a prerequisite of solder wetting. Underfill voids and outgassing are found to cause chip drift and tilt during the reflow process. In addition, symmetry of the underfill flow and fillet formation is identified as a critical factor in maintaining chip to substrate alignment. During solder wetting of the metallization pads on the substrate, the underfill needs to maintain a low viscosity. With the selection of a thermally stable underfill and corresponding process development, wafer-level flip chip assemblies with good solder interconnects are demonstrated 相似文献
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Bradley E. III Hranisavljevic J. 《Electronics Packaging Manufacturing, IEEE Transactions on》2001,24(4):255-260
There is tremendous interest at present with Pb-free solder assembly in the surface mount assembly industry in response to recent Japanese and European initiatives and proposed governmental restrictions regarding Pb usage and disposal. Many different solder alloys have been proposed as potential Pb-free solder replacements and the most promising of these fall into the general alloy families of tin-silver (Sn-Ag), tin-silver-copper (Sn-Ag-Cu) and tin-silver-bismuth (Sn-Ag-Bi). Published melting point data on some of these alloys indicates that they should be capable of reduced reflow temperatures relative to the commonly available Sn-3.5Ag alloy, which melts at 221°C. Differential scanning calorimetry (DSC) and reflow visualization was used to characterize the melting and wetting of the Pb-free alloys and generate the practical reflow temperature requirements. This was compared to the DSC data to gain insight on the meaning of the DSC melting data for surface mount applications. The results show that, in general, the wetting performance of the Sn-Ag-Bi alloys are more similar to Sn-Ag and Sn-Ag-Cu than would be predicted by the major onset melting temperature data as measured by the DSC 相似文献
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在表面贴装技术(SMT)大规模生产过程中,如果能够对焊接合格率进行预测,无疑对提高SMT产品的生产率、产品可靠性及成本控制具有重要意义.以球栅阵列(BGA)器件为例,研究SMT焊接合格率的预测方法.通过统计分析,结合焊点成形软件的方法,建立了BGA器件焊接合格率的预测模型,运用该模型可以找出影响焊接合格率的制约因素.结合仿真技术模拟焊点形态,发现引起焊接缺陷各参数之间的关系,并提出相应的解决方案. 相似文献
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To analyze the withdrawal force curve in the wetting balance curve, wetting balance tests using the 63Sn-37Pb and 96.5Sn-3.6Ag
eutectic solders were conducted by varying the immersion speed, sample perimeter, and solder temperature. The mechanism of
the withdrawal force curve was reviewed and a new method for calculating the surface tension of solders using the withdrawal
force curve was introduced. The results showed that the maximum point of the withdrawal force curve is generated when the
sliding solder meets the bottom corners of a sample and the contact angle is reduced to zero. The maximum withdrawal force
subtracted by end force can be expressed using force balance equation as F=pγ. Therefore, the surface tension of the solder
can be calculated by dividing the maximum withdrawal force by the sample parameter. 相似文献
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F. M. Hosking F. G. Yost E. A. Holm J. R. Michael 《Journal of Electronic Materials》1996,25(7):1099-1107
Various solderability tests have been developed over the years to quantify the wetting behavior of solder on metallic surfaces.
None offer an exact measure of capillary flow normally associated with conventional plated-through-hole and surface mount
soldering. With shrinking package designs, increasing reliability requirements, and the emergence of new soldering technologies,
there is a growing need to better understand and predict the flow of solder on printed wiring board (PWB) surfaces. Sandia
National Laboratories has developed a capillary flow solderability test, through a joint effort with the National Center for
Manufacturing Sciences, that considers this fundamental wetting issue for surface mount technology. The test geometry consists
of a metal strip (width, 8) connected to a circular metal pad (radius, rc). Solder flow from the pad onto the strip depends on the geometric relationship between 8 and rc. Test methodology, experimental results, and validation of a flow model are presented in this paper. 相似文献
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Soon-Min Hong Jae-Yong Park Jae-Pil Jung Choon-Sik Kang 《Journal of Electronic Materials》2001,30(8):937-944
The wetting balance test was performed in an attempt to estimate the fluxless wetting properties of under bump metallurgy
(UBM)-coated Si-wafer and top surface metallurgy (TSM)-coated glass substrate to SnPb solder. The wetting curves of the single-and
double-side-coated UBM had a similar shape and the parameters characterizing the curve shape showed a similar tendency as
a function of temperature. Wetting property estimation was possible with the new wettability indices from the wetting curves
of one side-coated specimens; Fmin, Fs, and ts. Au/Cu/Cr UBM was better than Au/Ni/Ti UBM from the point of wetting time. For TSM, it was more effective to use Cu as a
wetting layer with Au as a protection layer than to use Au as a wetting layer alone. The contact angle of one-side-coated
Si-plate to SnPb solder can be calculated from the force balance equation by measuring static state force and tilt angle.
The contact angles of Au/Cu/Cr and Au/Ni/Ti UBM of Si-wafer to SnPb solder were 59.9° and 63.9°, respectively. The contact
angles of Au/Cu/Cr and Au/Cr TSM of glass to SnPb were 78.9 and 76.1°, respectively. 相似文献
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利用二次曝光全息干涉技术对表面封装组件(SMA)在功率循环中的离面变形场进行了测试.为解决从器件边缘到印制电路板(PCB)间干涉条纹级次的不连续问题,实验中采用了"搭桥"技术来处理表面封装器件(SMD)和PCB的变形失配;此外,全息干涉技术还被用于一个实际产品(硬盘驱动器)的无损在线检测.结果表明:模塑J引线封装体(PLCC)和PCB由于中心热源及材料的热膨胀系数差而导致离面弯曲变形;沿器件边缘,引线和焊点经历了非共面的离面变形;通过正常硬盘驱动电路板和失效板的干涉条纹数量的对比,能快速简捷地检测板的质量.全息干涉测量法在微电子技术可靠性分析领域有广泛的应用前景. 相似文献
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利用二次曝光全息干涉技术对表面封装组件(SMA)在功率循环中的离面变形场进行了测试.为解决从器件边缘到印制电路板(PCB)间干涉条纹级次的不连续问题,实验中采用了"搭桥"技术来处理表面封装器件(SMD)和PCB的变形失配;此外,全息干涉技术还被用于一个实际产品(硬盘驱动器)的无损在线检测.结果表明:模塑J引线封装体(PLCC)和PCB由于中心热源及材料的热膨胀系数差而导致离面弯曲变形;沿器件边缘,引线和焊点经历了非共面的离面变形;通过正常硬盘驱动电路板和失效板的干涉条纹数量的对比,能快速简捷地检测板的质量.全息干涉测量法在微电子技术可靠性分析领域有广泛的应用前景. 相似文献