The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Jian Ku Shang - One of the best experts on this subject based on the ideXlab platform.
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Highly Solderability of FeP film in contact with SnAgCu solder
Journal of Alloys and Compounds, 2020Co-Authors: Haifei Zhou, Jian Ku Shang, Xiaoning SongAbstract:Abstract New under bump metallization (UBM) is required for future microelectronics to minimize reliability concerns with solder interconnects. In this study, electroless FeP film was prepared as UBM. Solderability of electroless NiP, electrodeposite Fe and electroless FeP films with eutectic SnAgCu solder was investigated by static wetting tests and wetting balance measurements. Results revealed that the Solderability of NiP film has almost no change with thermal aged for the film in air atmosphere increasing. The contact angles for FeP and Fe films with SnAgCu solder increased and the maximum wetting force decreased with heating time increasing from 0 h, 48 h, 89 h–160 h at 180 °C. But the Solderability of FeP film was found to be better than those of NiP and Fe whether the films in base or thermal aged at 180 °C for 89 h. Even after thermal aged in air atmosphere at 180 °C for 160 h, the FeP also performed the smallest contace angle compared with the NiP and the Fe. Oxide layer on the surface of FeP was much easier to be removed by rosin mildly activated flux during reflow process because loose structure. It was proved to be the key for the highly Solderability of electroless FeP.
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degradation of Solderability of electroless nickel by phosphide particles
Surface & Coatings Technology, 2007Co-Authors: Aiping Xian, Jian Ku ShangAbstract:Wetting of electroless nickel by the eutectic SnAgCu solder alloy was investigated in the as-deposited and annealed conditions. In the as-deposited state, P content in the nickel had a minimal effect on the Solderability of the electroless nickel. Upon annealing, numerous nickel phosphide particles precipitated out of the electroless nickel with a high-P content. The presence of these phosphide precipitates reduced the Solderability of the electroless nickel both in terms of the wetting force and wetting kinetics. While weakening in the wetting force is related to the inferior contact condition, the slower wetting kinetics is explained in terms of the reduction in the dissolution rate of the electroless nickel from non-soluble phosphide particles. (c) 2007 Elsevier B.V. All rights reserved.
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Solderability of electrodeposited fe ni alloys with eutectic snagcu solder
Journal of Materials Science & Technology, 2007Co-Authors: Lei Zhang, Aiping Xian, Jian Ku ShangAbstract:Solderabilities of electrodeposited Fe-Ni alloys with SnAgCu solder were examined by wetting balance measurements and compared to those of pure Ni and pure Fe platings. Excellent Solderability was found on the Ni-52Fe plating as both the wetting force and kinetics approached or exceeded those on the pure Ni. However, upon further increase in Fe content to 75 at. pct, the Solderability of the alloy was severely degraded even though it was still better than that of the pure Fe plating. X-ray photoelectron spectroscopy showed that such a strong dependence of Solderability on Fe content is related to the much thinner, incomplete oxide coverage of Ni-rich plating surface.
Xin-ping Zhang - One of the best experts on this subject based on the ideXlab platform.
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Effects of flux activators and processing parameters on Solderability and stability of the aluminum solder paste used for automated assembly of LED lighting components
2016 17th International Conference on Electronic Packaging Technology (ICEPT), 2016Co-Authors: Lang Zhang, Min-bo Zhou, Fu-shun Qiu, Xin-ping ZhangAbstract:In recent years there has been an increasing demand of aluminum solder pastes used for automated assembly of LED lighting components, such as heat sinks and supporting frames of LED modules. However, it is well-known that soldering of aluminum and its alloys at low soldering temperatures has long been difficult. In this study, the effects of flux activators (i.e., zinc salt A and B, and tin salt A) and processing parameters, such as the peak temperature of heating the flux and soldering heating rate, on the Solderability and stability of solder pastes for 6061 aluminum alloy were investigated. The results show that the wettability of solder pastes changes with varying the contents of inorganic salts and the peak temperature used for heating the flux, and the Solderability of solder pastes depends strongly on the heating rate used in the reflow soldering. At a low soldering heating rate of 2°C/s, the content of zinc salt A is a key factor in increasing the spreading ability of solder pastes on 6061Al, while the addition of tin salt A decreases the spreading ability. When a relatively high soldering heating rate of 20°C/s was applied, three kinds of inorganic salts show similar effects on the spreading ability, meanwhile, tin salt A is found to be beneficial for improving the Solderability of aluminum solder pastes.
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influence of metal oxide salt content in the aluminum soldering flux on Solderability and corrosion resistance of sn 0 7cu 6061al joints
International Conference on Electronic Packaging Technology, 2015Co-Authors: Min-bo Zhou, Li-bing Zhou, Lang Zhang, Xin-ping ZhangAbstract:A water-soluble soldering flux, aiming at making the flux-cored Sn-0.7Cu solder wire for soldering aluminum and its alloys, has been developed in this study, whose active matrix contains different amounts of zinc and tin metal oxides or salts. The Solderability of Sn-0.7Cu solder on 6061 aluminum alloy (6061Al) substrate and corrosion resistance of Sn-0.7Cu/6061Al joints using the developed flux are evaluated systematically. Results show that an increase in content of both zinc-oxide and zinc-salt in the flux can significantly improve the Solderability of Sn-0.7Cu solder and chemical corrosion resistance of Sn-0.7Cu/6061Al joints, in particular the increase of zinc-salt content shows a more effective role in increasing the corrosion resistance of the joints. There are a large number of micro-sized Zn-containing particles and network-like Zn-containing phase on the surface of 6061Al arisen from the reaction between the substrate and flux containing zinc-oxide or zinc-salt. During the soldering process, the complex reactions among the flux, Sn-0.7Cu solder and 6061Al result in formation of a combined system of Sn-0.7Cu/Zn/Al, in which Zn plays a key role in forming Zn metallization on the surface of 6061 aluminum. Meanwhile, an increase in content of tin-salt in the flux can also improve the Solderability of Sn-0.7Cu solder but reduce the chemical corrosion resistance of Sn-0.7Cu/6061Al joints. There is a flat Sn metallization layer formed on the surface of 6061Al. The result indicates that the role of Sn metallization is only for improving the Solderability of Sn-0.7Cu solder rather than effectively enhancing the corrosion resistance of Sn-0.7Cu/6061Al joints.
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Influence of metal-oxide/salt content in the aluminum soldering flux on Solderability and corrosion resistance of Sn-0.7Cu/6061Al joints
2015 16th International Conference on Electronic Packaging Technology (ICEPT), 2015Co-Authors: Min-bo Zhou, Li-bing Zhou, Lang Zhang, Fu-shun Qiu, Xin-ping ZhangAbstract:A water-soluble soldering flux, aiming at making the flux-cored Sn-0.7Cu solder wire for soldering aluminum and its alloys, has been developed in this study, whose active matrix contains different amounts of zinc and tin metal oxides or salts. The Solderability of Sn-0.7Cu solder on 6061 aluminum alloy (6061Al) substrate and corrosion resistance of Sn-0.7Cu/6061Al joints using the developed flux are evaluated systematically. Results show that an increase in content of both zinc-oxide and zinc-salt in the flux can significantly improve the Solderability of Sn-0.7Cu solder and chemical corrosion resistance of Sn-0.7Cu/6061Al joints, in particular the increase of zinc-salt content shows a more effective role in increasing the corrosion resistance of the joints. There are a large number of micro-sized Zn-containing particles and network-like Zn-containing phase on the surface of 6061Al arisen from the reaction between the substrate and flux containing zinc-oxide or zinc-salt. During the soldering process, the complex reactions among the flux, Sn-0.7Cu solder and 6061Al result in formation of a combined system of Sn-0.7Cu/Zn/Al, in which Zn plays a key role in forming Zn metallization on the surface of 6061 aluminum. Meanwhile, an increase in content of tin-salt in the flux can also improve the Solderability of Sn-0.7Cu solder but reduce the chemical corrosion resistance of Sn-0.7Cu/6061Al joints. There is a flat Sn metallization layer formed on the surface of 6061Al. The result indicates that the role of Sn metallization is only for improving the Solderability of Sn-0.7Cu solder rather than effectively enhancing the corrosion resistance of Sn-0.7Cu/6061Al joints.
Bjoern Zeysing - One of the best experts on this subject based on the ideXlab platform.
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An Organic Metal/Silver Nanoparticle Finish on Copper for Efficient Passivation and Solderability Preservation
Nanoscale Research Letters, 2007Co-Authors: Bernhard Wessling, Marco Thun, Carmen Arribas-sanchez, Sussane Gleeson, Joerg Posdorfer, Melanie Rischka, Bjoern ZeysingAbstract:For the first time, a complex formed by polyaniline (in its organic metal form) and silver has been deposited on copper in nanoparticulate form. When depositing on Cu pads of printed circuit boards it efficiently protects against oxidation and preserves its Solderability. The deposited layer has a thickness of only nominally 50 nm, containing the Organic Metal (conductive polymer), polyaniline, and silver. With >90% (by volume), polyaniline (PAni) is the major component of the deposited layer, Ag is present equivalent to a 4 nm thickness. The Pani–Ag complex is deposited on Cu in form of about 100 nm small particles. Morphology, electrochemical characteristics, anti-oxidation and Solderability results are reported.
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an organic metal silver nanoparticle finish on copper for efficient passivation and Solderability preservation
Nanoscale Research Letters, 2007Co-Authors: Bernhard Wessling, Marco Thun, Sussane Gleeson, Joerg Posdorfer, Melanie Rischka, Carmen Arribassanchez, Bjoern ZeysingAbstract:For the first time, a complex formed by polyaniline (in its organic metal form) and silver has been deposited on copper in nanoparticulate form. When depositing on Cu pads of printed circuit boards it efficiently protects against oxidation and preserves its Solderability. The deposited layer has a thickness of only nominally 50 nm, containing the Organic Metal (conductive polymer), polyaniline, and silver. With >90% (by volume), polyaniline (PAni) is the major component of the deposited layer, Ag is present equivalent to a 4 nm thickness. The Pani–Ag complex is deposited on Cu in form of about 100 nm small particles. Morphology, electrochemical characteristics, anti-oxidation and Solderability results are reported.
F Macedo - One of the best experts on this subject based on the ideXlab platform.
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Effect of the Soldering Atmosphere on the Wettability Between Sn4.0Ag0.5Cu (in wt.%) Lead-Free Solder Paste and Various Substrates
Journal of Materials Engineering and Performance, 2018Co-Authors: D. Soares, S. Teixeira, C. S. Lau, J. C. Teixeira, Leonor Ribas, R. Alves, M F Cerqueira, Henrique Leitao, F MacedoAbstract:The “degree of wetting,” which is related to the contact angle (θ) between the molten solder and the substrate, is a useful parameter on the Solderability process control. The contact angle, however, is strongly dependent on the type of substrate surface finish and used atmosphere (inert or non-inert). Furthermore, the surface tension, being an important parameter on the Solderability process and performance, can also be achieved if the contact angle is known. In this study, the SAC405 [Sn4.0Ag0.5Cu (in wt.%)] solder paste contact angle was measured, by the “sessile drop” method, as a function of the temperature, surface pad finish and used atmosphere. The results are discussed, and the contact angles obtained for the different conditions are compared and discussed. Then, the surface tension (experimental) was obtained from the measured contact angle and compared with the obtained by using computation models (theoretical). The experiments performed in high vacuum conditions, i.e., low oxygen content, over a temperature range, allowed the evaluation and understanding of the surface oxides layers role on the solder wettability. The present study shows that in the soldering process, even in an inert atmosphere, usually used in industry, occurs the formation of superficial oxides, over the liquid solder and/or at the pad surfaces, that strongly affects the solder paste wettability, specially with Sn and OSP (organic Solderability preservative) finishing. Differences in contact angle of ≥ 10° were determined between the two types of used atmospheres. The experimental surface tension and theoretical surface tension obtained, for the NiAu substrate type, present good correlation. The lower contact angle values were obtained for the NiAu and OSP finish types, independently of the atmosphere type.
Frantisek Steiner - One of the best experts on this subject based on the ideXlab platform.
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The area of spread Solderability test use for roughness influence assessment
33rd International Spring Seminar on Electronics Technology ISSE 2010, 2010Co-Authors: Tomas Novak, Frantisek SteinerAbstract:The article deals with the influence of surface roughness on Solderability. The area of spread test was used as a method for Solderability measurement. For this measurement, test samples made from substrates for printed circuit boards, small solder balls, and two soldering technologies - vapor-phase and reflow soldering - were used. These technologies have been used because of similarity with the industrial process of soldering. The subjects of examination and comparison were wetting angle and expanse of melted solder on the surface. The paper presents results and conclusions from Solderability testing of printed circuit boards with various surface roughnesses. Other conclusion is comparison of several types of fluxes and their impact on solder wetting on roughened surface.
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Surface roughness influence on Solderability
2009 32nd International Spring Seminar on Electronics Technology, 2009Co-Authors: Tomas Novak, Frantisek SteinerAbstract:The article deals with results of Solderability testing of printed circuit boards. The wetting balance test was used for Solderability testing. This test makes wetting force measurement possible as a function of time. Measured values are recorded automatically. Surface roughness is one of parameters, which influence surface wetting. The article will present the results and comparison of tested printed circuit boards with different surface roughness. This comparison will be made for several surface finish types. Test specimens of printed circuit boards with surface finishes SnG (galvanic tin), SnC (immersion tin), Cu (pure copper), OSP (organic Solderability preservative) and ENIG (electroless nickel immersion gold) were tested. The test specimens were purposely roughened by different abrasive paper before Solderability testing. Roughness created on surface finishes were oriented vertically and horizontally.
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Double-sided preheating influence on Solderability
2008 31st International Spring Seminar on Electronics Technology, 2008Co-Authors: Petr Harant, Frantisek SteinerAbstract:Paper deals with results of Solderability testing of Printed Circuit Boards (PCBs). For measurement was used one of the Solderability evaluation methods known as the wetting balance test. The wetting balance test measures the wetting forces imposed by the molten solder on the test surface as it is dipped into and held in the solder bath as a function of time. Paper will present the comparison of results of printed circuit board Solderability test with preheating in agreement with IPC/EIA J-STD-003A, with IEC 60068-2-54 and with hot air double-sided preheating. This comparison will be also made for several lead-free surface finish types. It was tested printed circuit board coupons with surface finishing of galvanic tin, immersion tin, ENIG (electroless nickel immersion gold), OSP (organic Solderability preservative) and pure copper.
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Influence of special cleaning compounds on PCBs Solderability
2008 2nd Electronics System-Integration Technology Conference, 2008Co-Authors: Petr Harant, Frantisek Steiner, Jiri Stary, Petr StejskalAbstract:Paper deals with results of Solderability testing of printed circuit boards (PCBs). The target of Solderability testing was an assessment of cleaning substance influence on Solderability. Several types of cleaning substances were used for PCB cleaning. Isopropylalcohol and special cleaning liquids were applied on PCBs before Solderability testing. These cleaning liquids shall clean up the surface of PCB from impurities. Most often used lead-free surface finishes were tested (coupons of printed circuit boards with surface finishes galvanic tin, immersion tin, ENIG (electro less nickel immersion gold), OSP (organic Solderability preservative) and pure copper).
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Solderability of lead-free surface finished PCB
2007 30th International Spring Seminar on Electronics Technology (ISSE), 2007Co-Authors: Petr Harant, Frantisek SteinerAbstract:This paper deals with results of Solderability testing. The wetting balance test is used for the evaluation of wetting performance. Dissolving and removing of oxides and contaminations from the surface of a metal or alloy are the primary purposes of flux. Activated metal surface is easily wetted by the molten solder. However flux is corrosive. Other way of cleaning is the special cleaning liquid, e.g. Decotron F10. The paper presents the comparison of printed circuit board Solderability test results measured before and after cleaning. This comparison will be made for several surface finish types. Coupons of printed circuit boards with surface finishes galvanic tin, immersion tin, pure copper, OSP (organic Solderability preservative) and ENIG (electro less nickel immersion gold) were tested. The environment of storage can affect the Solderability of surface. That is why the Solderability was measured before and after ageing also.
