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Johan Liu - One of the best experts on this subject based on the ideXlab platform.
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study of interfacial reactions in sn 3 5ag 3 0bi and sn 8 0zn 3 0bi sandwich structure solder joint with ni p cu Metallization on cu substrate
Journal of Alloys and Compounds, 2007Co-Authors: Peng Sun, Cristina Andersson, Xicheng Wei, Zhaonian Cheng, Dongkai Shangguan, Johan LiuAbstract:Abstract In this paper, the coupling effect in Sn–3.5Ag–3.0Bi and Sn–8.0Zn–3.0Bi solder joint with sandwich structure by long time reflow soldering was studied. It was found that the interfacial compound at the Cu substrate was binary Cu–Sn compound in Sn–Ag–Bi solder joint and Cu5Zn8 phase in Sn–Zn–Bi solder joint. The thickness of the Cu–Zn compound layer formed at the Cu substrate was greater than or equal to that of Cu–Sn compound layer, although the reflow soldering temperature of Sn–Zn–Bi (240 °C) was lower than that of Sn–Ag–Bi (250 °C). The stable Cu–Zn compound was the absolute preferential phase in the interfacial layer between Sn–Zn–Bi and the Cu substrate. The ternary (Cu, Ni)6Sn5 compound was formed at the Sn–Ag–Bi/Ni(P)–Cu Metallization interface, and a complex alloy Sn–Ni–Cu–Zn was formed at the Sn–Zn–Bi/Ni(P)–Cu Metallization interface. It was noted that Cu atoms could diffuse from the Cu substrate through the solder matrix to the Ni(P)–Cu Metallization within 1 min reflow soldering time for both solder systems, indicating that just 30 s was long enough for Cu to go through 250 μm diffusion length in the Sn–Ag–Bi solder joint at 250 °C. The coupling effect between Ni(P)/Cu Metallization and Cu substrate was confirmed as the type of IMCs at Ni(P) layer had been changed from Ni–Sn system to Cu–Sn system apparently by the diffusion effect of Cu atoms. The (Cu, Ni)6Sn5 layer at the Ni(P)/Cu Metallization grew significantly and its thickness was even greater than that of the Cu–Sn compound on the opposite side, however the growth of the complex alloy including Sn, Ni, Cu and Zn on the Ni(P)/Cu Metallization was suppressed.
Peng Sun - One of the best experts on this subject based on the ideXlab platform.
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study of interfacial reactions in sn 3 5ag 3 0bi and sn 8 0zn 3 0bi sandwich structure solder joint with ni p cu Metallization on cu substrate
Journal of Alloys and Compounds, 2007Co-Authors: Peng Sun, Cristina Andersson, Xicheng Wei, Zhaonian Cheng, Dongkai Shangguan, Johan LiuAbstract:Abstract In this paper, the coupling effect in Sn–3.5Ag–3.0Bi and Sn–8.0Zn–3.0Bi solder joint with sandwich structure by long time reflow soldering was studied. It was found that the interfacial compound at the Cu substrate was binary Cu–Sn compound in Sn–Ag–Bi solder joint and Cu5Zn8 phase in Sn–Zn–Bi solder joint. The thickness of the Cu–Zn compound layer formed at the Cu substrate was greater than or equal to that of Cu–Sn compound layer, although the reflow soldering temperature of Sn–Zn–Bi (240 °C) was lower than that of Sn–Ag–Bi (250 °C). The stable Cu–Zn compound was the absolute preferential phase in the interfacial layer between Sn–Zn–Bi and the Cu substrate. The ternary (Cu, Ni)6Sn5 compound was formed at the Sn–Ag–Bi/Ni(P)–Cu Metallization interface, and a complex alloy Sn–Ni–Cu–Zn was formed at the Sn–Zn–Bi/Ni(P)–Cu Metallization interface. It was noted that Cu atoms could diffuse from the Cu substrate through the solder matrix to the Ni(P)–Cu Metallization within 1 min reflow soldering time for both solder systems, indicating that just 30 s was long enough for Cu to go through 250 μm diffusion length in the Sn–Ag–Bi solder joint at 250 °C. The coupling effect between Ni(P)/Cu Metallization and Cu substrate was confirmed as the type of IMCs at Ni(P) layer had been changed from Ni–Sn system to Cu–Sn system apparently by the diffusion effect of Cu atoms. The (Cu, Ni)6Sn5 layer at the Ni(P)/Cu Metallization grew significantly and its thickness was even greater than that of the Cu–Sn compound on the opposite side, however the growth of the complex alloy including Sn, Ni, Cu and Zn on the Ni(P)/Cu Metallization was suppressed.
Heung Soo Kim - One of the best experts on this subject based on the ideXlab platform.
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Study of the Fracture Mechanisms of Electroplated Metallization Systems Using In Situ Microtension Test
Electronic Materials Letters, 2018Co-Authors: Sabeur Msolli, Heung Soo KimAbstract:This framework assesses the mechanical behavior of some potential thin/thick Metallization systems in use as either ohmic contacts for diamond semi-conductors or for Metallization on copper double bounded ceramic substrates present in the next-generation power electronics packaging. The interesting and unique characteristic of this packaging is the use of diamond as a semi-conductor material instead of silicon to increase the lifetime of embedded power converters for use in aeronautical applications. Theoretically, such packaging is able to withstand temperatures of up to 300 °C without breaking the semi-conductor, provided that the constitutive materials of the packaging are compatible. Metallization is very important to protect the chips and substrates. Therefore, we address this issue in the present work. The tested Metallization systems are Ni/Au, Ni/Cr/Au and Ni/Cr. These specific systems were studied since they can be used in conjunction with existing bonding technologies, including AuGe soldering, Ag–In Transient liquid Phase Bonding and silver nanoparticle sintering. The Metallization is achieved via electrodeposition, and a mechanical test, consisting of a microtension technique, is carried out at room temperature inside a scanning electron microscopy chamber. The technique permits observations the cracks initiation and growth in the Metallization to locate the deformation zones and identify the fracture mechanisms. Different failure mechanisms were shown to occur depending on the metallic layers deposited on top of the copper substrate. The density of these cracks depends on the imposed load and the involved Metallization. These observations will help choose the Metallization that is compatible with the particular bonding material, and manage mechanical stress due to thermal cycling so that they can be used as a constitutive component for high-temperature power electronics packaging.Graphical Abstract
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Mechanical behavior and adhesion of the Ti/Cr/Au Metallization scheme on diamond substrate
Advanced Engineering Materials, 2017Co-Authors: Sabeur Msolli, Joël Alexis, Heung Soo KimAbstract:The mechanical properties of a Ti/Cr/Au Metallization system deposited on a heavily doped diamond substrate are evaluated, first using nano-indentation tests. Various kinds of conditions are adopted, such as small and high force loadings. These tests are completed by in situ scanning electron microscopy observations of the surface. The adhesion of such multilayer on the diamond substrate is assessed using nano-scratching tests. The profiles of the obtained scratches are analyzed to detect any singularities or defects. Finally, a cross-section topography is performed, in order to obtain the cross profile of the scratch, and to determine the scratch hardness parameter of the Metallization system. The Ti/Cr/Au Metallization system is a potential candidate to play the role of ohmic contact on diamond. Therefore, its adhesion to diamond is important, since the whole power electronic assembly is mainly subjected to thermal cycling during service. The Metallization system must adhere well to diamond, so as to resist temperature gradients and thermal strains that are widely observed in extreme thermal conditions. Otherwise, debonding phenomena may occur, and the whole electronic packaging fail.
Sabeur Msolli - One of the best experts on this subject based on the ideXlab platform.
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Study of the Fracture Mechanisms of Electroplated Metallization Systems Using In Situ Microtension Test
Electronic Materials Letters, 2018Co-Authors: Sabeur Msolli, Heung Soo KimAbstract:This framework assesses the mechanical behavior of some potential thin/thick Metallization systems in use as either ohmic contacts for diamond semi-conductors or for Metallization on copper double bounded ceramic substrates present in the next-generation power electronics packaging. The interesting and unique characteristic of this packaging is the use of diamond as a semi-conductor material instead of silicon to increase the lifetime of embedded power converters for use in aeronautical applications. Theoretically, such packaging is able to withstand temperatures of up to 300 °C without breaking the semi-conductor, provided that the constitutive materials of the packaging are compatible. Metallization is very important to protect the chips and substrates. Therefore, we address this issue in the present work. The tested Metallization systems are Ni/Au, Ni/Cr/Au and Ni/Cr. These specific systems were studied since they can be used in conjunction with existing bonding technologies, including AuGe soldering, Ag–In Transient liquid Phase Bonding and silver nanoparticle sintering. The Metallization is achieved via electrodeposition, and a mechanical test, consisting of a microtension technique, is carried out at room temperature inside a scanning electron microscopy chamber. The technique permits observations the cracks initiation and growth in the Metallization to locate the deformation zones and identify the fracture mechanisms. Different failure mechanisms were shown to occur depending on the metallic layers deposited on top of the copper substrate. The density of these cracks depends on the imposed load and the involved Metallization. These observations will help choose the Metallization that is compatible with the particular bonding material, and manage mechanical stress due to thermal cycling so that they can be used as a constitutive component for high-temperature power electronics packaging.Graphical Abstract
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Mechanical behavior and adhesion of the Ti/Cr/Au Metallization scheme on diamond substrate
Advanced Engineering Materials, 2017Co-Authors: Sabeur Msolli, Joël Alexis, Heung Soo KimAbstract:The mechanical properties of a Ti/Cr/Au Metallization system deposited on a heavily doped diamond substrate are evaluated, first using nano-indentation tests. Various kinds of conditions are adopted, such as small and high force loadings. These tests are completed by in situ scanning electron microscopy observations of the surface. The adhesion of such multilayer on the diamond substrate is assessed using nano-scratching tests. The profiles of the obtained scratches are analyzed to detect any singularities or defects. Finally, a cross-section topography is performed, in order to obtain the cross profile of the scratch, and to determine the scratch hardness parameter of the Metallization system. The Ti/Cr/Au Metallization system is a potential candidate to play the role of ohmic contact on diamond. Therefore, its adhesion to diamond is important, since the whole power electronic assembly is mainly subjected to thermal cycling during service. The Metallization system must adhere well to diamond, so as to resist temperature gradients and thermal strains that are widely observed in extreme thermal conditions. Otherwise, debonding phenomena may occur, and the whole electronic packaging fail.
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Assessment of candidate Metallization systems deposited on diamond using nano-indentation and nano-scratching tests
Thin Solid Films, 2016Co-Authors: Sabeur Msolli, Joël Alexis, Olivier Dalverny, Moussa KaramaAbstract:Mechanical suitability of ohmic contacts among the select Metallization systems, deposited on a p-type heavily boron-doped homoepitaxial diamond layer, was evaluated via mechanical tests on the nanoscale. Two candidate Metallization systems were considered: Si/Al and Ti/Pt/Au. Metallizations were performed using two different techniques: plasma-enhanced chemical vapour deposition and “lift-off”. Effectiveness of the techniques was assessed via mechanical tests on the microscale and the nanoscale. Nano-indentation experiments were performed to determine the mechanical properties of the layers. Nano-scratching experiments were used to evaluate the mechanical adhesion on the diamond substrate. Scanning electron microscopy was applied for observation of the morphology of the surface and the indent and for detecting defects.
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An assessment of contact Metallization for high power and high temperature diamond Schottky devices
Diamond and Related Materials, 2012Co-Authors: Sodjan Koné, Sabeur Msolli, Henri Schneider, Karine Isoird, Fabien Thion, Jocelyn Achard, Riadh Issaoui, Joël AlexisAbstract:Different metals W, Al, Ni and Cr were evaluated as Schottky contacts on the same p-type lightly boron doped homoepitaxial diamond layer. The current-voltage (I-V) characteristics, the series resistance and the thermal stability are discussed in the range of RT to 625 K for all Schottky devices. High current densities close to 3.2 kA/cm2 are displayed and as the series resistance decreases with increasing temperature, proving the potential of diamond for high power and high temperature devices. The thermal stability of metal/diamond interface investigated with regards to the Schottky barrier height (SBH) and ideality factor n fluctuations indicated that Ni and W are thermally stable in the range of RT to 625 K. Current-voltage measurements at reverse bias indicated a maximum breakdown voltage of 70 V corresponding to an electric field of 3.75 MV/cm. Finally, these electrical measurements have been completed with mechanical adhesion tests of contact Metallizations on diamond by nano-scratching technique. These studies clearly reveal Ni as a promising contact Metallization for high power, high temperature and good mechanical strength diamond Schottky barrier diode applications.
Zhong Chen - One of the best experts on this subject based on the ideXlab platform.
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interface reaction between an electroless ni co p Metallization and sn 3 5ag lead free solder with improved joint reliability
Acta Materialia, 2014Co-Authors: Ying Yang, J N Balaraju, Yizhong Huang, Zhong ChenAbstract:Abstract To address the reliability challenges brought about by the accelerated reaction with the implementation of lead-free solders, an electrolessly plated Ni–Co–P alloy (3–4 wt.% P and 9–12 wt.% Co) was developed as the solder Metallization in this study. Three compounds layers, (Ni,Co) 3 Sn 4 , (Ni,Co) 3 P and (Ni,Co) 12 P 5 , are formed at the reaction interface. Nano-sized voids are visible in the (Ni,Co) 3 P layer under transmission electron microscopy, but no large voids are found under scanning electron microscopy. This is an indication of effective diffusion barrier performance by the Ni–Co–P Metallization compared with the binary Ni–P Metallization. The influence of interfacial reaction on the solder joint reliability was reported through the evaluation of the tensile strength of solder micro-joints. Upon aging at 180 °C for 600 h, the tensile strength of Ni–Co–P/Sn–3.5Ag solder joint remains high, and the failure is caused by the bulk solder necking and collapse. As a comparison, the tensile strength of the Ni–P/Sn–3.5Ag solder joint drops significantly after aging for 400 h at 180 °C, and the fracture mode has shifted from ductile failure in the bulk solder to brittle failure at the solder joint interface. The Ni–Co–P Metallization, having a much slower consumption rate and improved resistance to joint strength degradation during long-term aging treatment, is a potential candidate for future microelectronic solder Metallization materials.
