共查询到20条相似文献,搜索用时 109 毫秒
1.
从β-锡单晶晶体结构各向异性着手,研究总结了其变形行为:①拉伸性能及温度的影响;②蠕变性能与蠕变机制;③在一定载荷下,β-锡单晶的位错运动和滑移系开动情况。与和体心、面心立方金属相比,具有体心四方结构的β-锡单晶基本性能的研究还不完善;对于β-锡单晶的研究不仅有助于对β-锡多晶力学行为的机理性认识、细观尺度的力学模拟,而且对工业界新系列无铅焊料的开发有一定指导意义。 相似文献
2.
随着人们环保意识的提高,无铅焊料替代传统的锡铅焊料成为电子行业的必然趋势。Sn-Zn系无铅焊料因为熔点接近传统锡铅焊料,且具有优良的力学性能而被广泛关注,有望替代传统焊料。目前Sn-Zn系无铅焊料在润湿性、抗氧化性、抗腐蚀性等方面存在一定的问题。其中,焊料的抗腐蚀性对电子产品的寿命和安全起着决定性作用,因此,具有良好的抗腐蚀性能是开发无铅焊料的关键之一。就当下研究比较成熟的Sn-Zn系焊料的抗腐蚀性能进行研究。指出了元素合金化对Sn-Zn焊料的影响,并对抗腐蚀机理进行阐述。 相似文献
3.
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
4.
5.
6.
前言:多年来,锡铅焊料在电子元器件的焊接中起到了重要的作用,然而,近十几年来,由于人们对其赖以生存的环境越来越重视,所以,对锡铅焊料的使用加以限制乃至完全取缔。因此,国际上各有关生产厂家研制出各种不同的锡铅焊料替代产品,即:无铅焊料。在实际的生产应用中这些替代产品还不能够完全与锡铅焊料蓖关,在兼容性和可靠性等方面还需进一步完善。本文主要对实施无铅焊接前应考虑到可能出现的问题,并针对无铅焊料在生产中出现的问题做一些简要的分析,以防止类似缺陷的产生或少出现这样的问题。[编者按] 相似文献
7.
8.
Marji Baumann Phill Celaya 《今日电子》2006,(10):46-46
随着欧洲的RoHS和WEEE指令已于2006年7月1日开始执行,许多元件供应商面临着使其产品符合无铅环境的挑战。两个指令都要解决将铅从元件中去除的问题。半导体公司必须选择高性价比、与含铅焊料逆向兼容,并与无铅焊料前向兼容的无铅镀层策略。逆向兼容表示无铅元件能够用锡铅(SnPb)焊料回流工艺安放在PCB上。前向兼容表示目前的锡铅工艺能够在面板组装中,与无铅焊料一起使用。 相似文献
9.
10.
11.
The Bi-43%Sn eutectic solder alloy is a candidate for lead-free replacement of the widely used Pb-Sn solders. The alloy exhibits
a microstructural instability at elevated service temperatures causing extensive coarsening and nonuniformity in microstructure
and severe creep deformation. The addition of insoluble dispersoid particles using a novel magnetic distribution technique
has been found to significantly reduce the coarsening and the onset of tertiary creep. With improved microstuctural stability,
the useful service range of the Bi-Sn eutectic solder can be raised to a higher homologous temperature. 相似文献
12.
The characteristics of vibration fracture of Pb-Sn and lead-free Sn-Zn eutectic solders 总被引:1,自引:0,他引:1
This work investigated the fatigue fracture characteristics of Sn-7∼11wt.%Zn and Sn-30∼50wt.%PPb solder alloys under resonant
vibration. For the alloys containing proeutectic Sn-rich grains, the results show stratum appearance on the deformation of
coarse proeutectic grains. This stratum-type deformation will reduce the vibration resistance of Pb-Sn solder by inducing
cracks. For the Sn-Zn system, fine eutectic structure will cause cracks to form and coalesce easily in the regions concentrated
with small fibrous deformation grains, whereas hypereutectic structure shows coarse proeutectic Zn-rich particles as the crack
initiation sites. Sn-t-Zn solders have better damping capacity than Pb-Sn solders. With hypoeutectic composition to induce
stratum-type deformation and under lower vibration strain, these lead-free solders tend to exhibit superior crack propagation
resistance, and, in that respect, are possible to replace Pb-Sn solders. 相似文献
13.
14.
Wetting Kinetics of Eutectic Lead and Lead-Free Solders: Spreading over the Cu Surface 总被引:1,自引:0,他引:1
Hui Zhao Dinesh Reddy Nalagatla Dusan P. Sekulic 《Journal of Electronic Materials》2009,38(2):284-291
Wetting kinetics of Sn, eutectic Sn-Ag, eutectic Sn-Cu, and eutectic Pb-Sn was studied using real-time in situ monitoring of the triple-line movement, facilitated by a hot-stage microscopy system under a controlled atmosphere. Significantly
different kinetics of lead versus lead-free solders is documented. In case of the eutectic lead solder, four characteristic
spreading stages were identified. Spreading of lead-free solders features two stages with a sharp change of the spreading
rate at the early stages of rather insignificant spreading. Scanning electron microscopy and energy-dispersive x-ray spectroscopy
analysis of the resolidified solder surface within a halo region is discussed. 相似文献
15.
J. C. Foley A. Gickler F. H. Leprevost D. Brown 《Journal of Electronic Materials》2000,29(10):1258-1263
The drive to replace the use of toxic lead metal and its alloys has spurred the development of many new lead-free solder alloys.
Moreover, current leaded solders lack shear strength, resistance to creep and to thermal-mechanical fatigue. Solder that exhibits
enhancements of these properties and retains solderability is crucial in applications where the solder joints are subjected
to thermal cycling, severe vibrations, and temperatures of up to 125°C. Modified ring and plug joints were made with 18 selected
lead-free solders and three well characterized lead-containing solders. Analysis of the results provides a guide for the design
of additional testing. 相似文献
16.
17.
Sn-Ag-Cu lead-free solders are regarded as a potential substitute for Pb-Sn solder alloys. In the current study, the non-reacting, non-coarsening ZnO nano-particles (ZnO NPs) were successfully incorporated into Sn–3.0Ag–0.5Cu (SAC305) lead-free solder by mechanical mixing of ZnO powders and melting at 900 °C for 2 h. Tensile creep testing was performed for plain SAC305 solder and SAC305-0.7 wt% ZnO NPs composite solders and a Garofalo hyperbolic sine power-law relationship was created from the experimental data to predict the creep mechanism as a function of tensile stress and temperature. Based on the tensile creep results, the creep resistance of SAC305 solder alloy was improved considerably with ZnO NPs addition, although the creep lifetime was increased. From microstructure observation, reinforcing ZnO NPs into SAC305 solder substantially suppressed the enlargement of Ag3Sn and Cu6Sn5 intermetallic compound (IMC) particles and decreased the spacing of the inter-particles between them, reduced the grain size of β-Sn and increased the eutectic area in the alloy matrix. The modification of microstructure, which leaded to a strong adsorption effect and high surface-free energy of ZnO NPs, could result in hindering the dislocation slipping, and thus provides standard dispersion strengthening mechanism. Moreover, the average activation energy (Q) for SAC305 and SAC305-0.7ZnO alloys were 50.5 and 53.1 kJ/mol, respectively, close to that of pipe diffusion mechanism in matrix Sn. 相似文献
18.
Investigation of Gold Nanoparticle Inks for Low-Temperature Lead-Free Packaging Technology 总被引:1,自引:0,他引:1
Gold nanoparticle inks were investigated as a potential candidate for lead-free packaging applications. Inks consisted of
surfactant-passivated nanoparticles dissolved in a solvent. Optimized gold inks are able to sinter at temperatures as low
as 120°C and achieve conductivities of up to 70% of bulk. Once sintered, the metallic structure reverts to bulk-like properties
and approaches bulk reliability and performance. Thus nanoparticle-based solders would operate at much lower homologous temperatures
as compared with alloy-based solders. Nanoparticle inks under investigation were sintered at 180°C. The resulting material
exhibited a resistivity of 5 μΩ cm, which is significantly lower than those of Pb-Sn and Sn-Ag-Cu. Electromigration studies were carried out and time to
failure was investigated as a function of temperature. Electromigration activation energy was calculated through Black’s equation
to be 0.52 eV, which is consistent with surface/grain boundary diffusion. These studies suggest that nanoparticle-ink-based
films show excellent robustness, due to their irreversible conversion to bulk-like materials. Nanoparticle inks are thus promising
candidates for next-generation lead-free solders. 相似文献
19.
从专利角度探讨Sn-Zn无铅焊料研究现状 总被引:1,自引:1,他引:0
无铅焊料的研发及专利权的保护是我国电子行业亟待解决的问题。文中结合中国专利权的特点,描述了世界各国在无铅焊料专利上的竞争以及Sn-Zn无铅焊料的专利申请状况,并据此分析了Sn- Zn无铅焊料的研发及应用状况、专利Sn-Zn无铅焊料的特点以及应用障碍,以期对我国自主知识产权的Sn-Zn无铅焊料的研发及无铅专利保护有所帮助。 相似文献
20.
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