通过关键词查论文: Pb-Free Solder

文章题目页数

作者: Jong Woong Kim, Sun Kyu Park, Seung Boo Jung
摘要: Ball shear test was investigated in terms of effects of important test parameters, i.e. shear height and shear speed, with an experimental and non-linear finite element analysis for evaluating the solder joint integrity of area array packages. A Pb-free solder composition was examined in this work: Sn-3Ag-6Bi-2In. The substrate was a common SMD (Solder Mask Defined) type with solder bond pad openings of 460㎛ in diameter. It could be observed that increasing shear height, at fixed shear speed, has the effect of decreasing shear force, while the shear force increased with increasing shear speed at fixed shear height. Too high shear height could cause some bad effects on the test results such as unexpected high standard deviation values or shear tip sliding from the solder ball surface. The low shear height conditions were favorable for screening the type of brittle interfacial failures or the degraded layers in the interfaces.
851
作者: Jong Woong Kim, Hyun Suk Chun, Sang Su Ha, Jong Hyuck Chae, Jin Ho Joo, Young Eui Shin, Seung Boo Jung
摘要: Board-level reliability of conventional Sn-37Pb and Pb-free Sn-3.0Ag-0.5Cu solder joints was evaluated using thermal shock testing. In the microstructural investigation of the solder joints, the formation of Cu6Sn5 intermetallic compound (IMC) layer was observed between both solders and Cu lead frame, but any crack or newly introduced defect cannot be found even after 2000 cycles of thermal shocks. Shear test of the multi layer ceramic capacitor (MLCC) joints were also conducted to investigate the effect of microstructural variations on the bonding strength of the solder joints. Shear forces of the both solder joints decreased with increasing thermal shock cycles. The reason to the decrease in shear force was discussed with fracture surfaces of the shear tested solder joints.
633
作者: Rungsinee Canyook, Kittichai Fakpan
摘要: In present study, Sn–9Zn, Sn–9Zn–xCu and Sn–9Zn–xNi solders (x = 1.0, 2.0 and 3.0 wt%) were prepared via melting process. Effects of Cu and Ni addition on microstructure, thermal behavior, wettability and corrosion resistance of Sn–9Zn solders were investigated. The experimental result showed that microstructure of the Sn–9Zn was composed of β–Sn and Zn–rich phases. Addition of Cu to the Sn–9Zn solders, Cu6Sn5 and Cu5Zn8 IMCs were observed. While addition of Ni to the Sn–9Zn solders, Ni3Sn4 and Ni5Zn21 IMCs were observed. It was also found that, amount of those IMCs obviously increased with increasing of Cu and Ni contents. The results obtained from thermal analysis showed that melting temperature of the Sn–9Zn solder was 199.6°C. While melting temperatures of the Sn–9Zn–1.0Cu and Sn–9Zn–1.0Ni solders were 199.9°C and 204.2°C, respectively. The Cu and Ni contents had little effect on both spread rate and wetting angle of the Sn–9Zn–xCu and Sn–9Zn–xNi solders. However, increasing of Cu and Ni contents significantly increased the corrosion potentials of the Sn–9Zn–xCu and Sn–9Zn–xNi solders.
9
作者: Hiroshi Nishikawa, Tadashi Takemoto, Takashi Uetani, Norihisa Sekimori
摘要: Recently the soldering iron tip has been severely damaged by molten Pb-free solders during operation due to the high reaction rate of metals in molten lead-free solder. The tip is usually protected by plated iron to prevent the direct contact of copper with molten solders. However, the plated iron tip is heavily dissolved into molten Pb-free solders and the life time of the iron tip is reduced. In this study the simple reaction test between Sn-3.0Ag-0.5Cu (mass%) solder and plated iron was carried out to estimate the dissolution of plated iron in molten Pb-free solder and the effect of the grain size of plated surface on the reaction between Pb-free solder and plated iron. An iron-plated copper was used as the test piece. The Pb-free solder was placed on the test piece and it was put into an oven held at 673, 703 and 733K for 3.6, 10.8 and 32.4ks. After heating, the dissolution thickness of plated iron was measured and the intermetallic compound between Pb-free solder and plated iron was analyzed by XRD. As a result, it has been made clear that the dissolution thickness of plated iron decreases with the decrease of the grain size and then the dissolution of plated iron in molten Pb-free solder is attributable to the grain size of plated iron.
405
作者: Jong Woong Kim, Seung Boo Jung
摘要: The effects of void formation on the joint strength and failure mode of the solder joints were examined. A computational modeling technique, i.e., finite element modeling, was employed to investigate the effects. The effects of location, size and number of void were also investigated and compared with the case that has no void in the solder ball. When there was 1 or more voids in the solder ball, the joint strength decreased regardless of the location, size, and number of voids. Especially, the shear force of the joints decreased about 50% when 3 voids were formed in the solder ball. From the stress analyses, the possibility of preliminary brittle interfacial failure should be lower when voids were formed in the solder ball.
546
作者: Noriyuki Kuwano, Sadanori Horikami, Marina Linus
摘要: The changes of microstructure in pure-Sn after deformation were investigated by electron microscopy. Two types of specimens were prepared: Sample-1; pure-Sn/Fe-42Ni, Sample-2; single crystalline pure-Sn. The growth of curling whiskers on Sample-1 was observed in-situ in a scanning electron microscope (SEM). A thin foil specimen of the curling whisker was made with a focused ion beam (FIB) mill. Transmission electron microscope (TEM) analysis confirmed that the curling whisker was of a single crystal regardless of its external shape. New models for growth process of a bent single-crystalline whisker were proposed. The models are composed of epitaxial growth and recrystallization. Electron back scatter diffraction (EBSD) analysis was performed for Sample-2. The results of EBSD strongly suggested that recrystallization proceeds even at room temperature. These experimental results are very important to understand the behavior of dynamical deformation and recrystallization of Sn metal, and useful in consideration the mitigation of whiskers.
341
作者: Xin Fu Tan, Mohd Arif Anuar Mohd Salleh, Stuart D. McDonald, Kazuhiro Nogita
摘要: This paper investigated the effect of trace addition of Al and Mg on the grain refinements of Cu6Sn5 in Sn-3wt%Ag-5wt%Cu high temperature solder alloys. Furthermore, the effect of Al and Mg addition on the Sn/Ag3Sn eutectic were also investigated. It was found that the addition of both Al and Mg successfully refined the Cu6Sn5 in Sn-3wt%Ag-5wt%Cu solder alloy. In addition, Al suppresses the formation of Ag3Sn in the Sn/Ag3Sn eutectic; while Mg promotes the formation of fine Sn/Ag3Sn eutectic microstructure. The refinement of Cu6Sn5 is believed to be due to heterogeneous nucleation by Al and Mg rich intermetallic particles respectively. Effect of Al and Mg addition on the undercooling of the Sn/Ag3Sn eutectic was found to be similar, both reducing undercooling effectively at a low addition rate of 0.025wt%. The addition of Al and Mg have mixed effect on the nucleation temperature of Cu6Sn5. It is found that the nucleation temperature of Cu6Sn5 is increased with 0.025wt% Al and 0.1wt% Mg addition to the unmodified alloy, while the nucleation temperature slowly decreases again as the trace element addition rate increases.
20
作者: Dae Gon Kim, Hyung Sun Jang, Young Jig Kim, Seung Boo Jung
摘要: In the present work, the growth kinetics of intermetallic compound layer formed in Sn-3.5Ag flip chip solder joints by solid-state isothermal aging was examined at temperatures between 80 and 150 °C for 0 to 60 days. The bumping for the flip chip devices was performed using an electroless under bump metallization. The quantitative analyses were performed on the intermetallic compound layer thickness as a function of aging time and aging temperature. The layer growth of the Ni3Sn4 intermetallic compound followed a parabolic law within a given temperature range. As a whole, because the value of the time exponent (n) is approximately equal to 0.5, the layer growth of the intermetallic compound was mainly controlled by diffusion mechanism in the temperature range studied. The apparent activation energy of the Ni3Sn4 intermetallic was 49.63 kJ/mol.
273
作者: Zhi Hao Chen, Wei Zheng, Fang Qiu Zu, Xie Bing Zhu, Yu Feng Sun
摘要: Currently, Pb-free is the primary trend of development for solder alloys, and the existing Pb-free solder alloys are still difficult to replace the traditional tin-lead solder alloys. How to further improve the welding properties of Pb-free solder alloys is the issue we currently faced. In this paper, through melt overheating treatment, the influence of liquid-liquid structure change (LLSC) on the structure and properties of SnZn8Bi3 Pb-free solder alloy has been studied. Experimental results show that the LLSC has obvious effects on the solidification process and solidified microstructure of SnZn8Bi3 alloy: bigger solidification undercooling degree in the solidification process, finer and more dispersed solidification structure, and more importantly, the mechanical and welding properties of the solder alloy have also been obviously improved.
489
作者: Dae Gon Kim, Sang Su Ha, Seung Boo Jung
摘要: The interfacial reaction and joint strength of the Pb-free flip chip solder joints were investigated. Microstructural investigations were conducted using scanning electron microscopy (SEM), and phase analysis of the intermetallic compound (IMC) was carried out using energy dispersive spectrometer (EDS). Cu6Sn5 IMC layer was formed at the as-reflowed state, and Cu3Sn was additionally settled at the interface between the Cu6Sn5 and Cu under bump metallurgy (UBM). Growth of the IMC layers followed the parabolic law, while the IMC layer growth was not highly affecting the mechanical properties of the solder joints. The shear force of the solder joints decreased because of the microstructural coarsening within the solder region.
550
显示20个文章标题中的1到10个