Article
Crystallography
Yang Li, Di Wu, Yabin Zhang, Liujue Wang, Songbai Xue
Summary: The Au-20Sn solder is widely used in high-end electronic products packaging. The oxygen content in the solder significantly affects wettability, spreading performance, mechanical properties, and gas tightness of the solder joints. An oxygen content lower than 27 ppm is required for reliable fluxless packaging.
Article
Materials Science, Multidisciplinary
Roman Kolenak, Igor Kostolny, Jaromir Drapala, Paulina Babincova, Martin Sahul
Summary: The research aimed to characterize the Zn-Al-Cu soldering alloy and study fluxless ultrasonic soldering of Al7075 aluminum alloy with copper substrate. The Zn-Al-Cu solder has a close-to-eutectic type microstructure and two phase transformations. The shear strength of Zn5Al3Cu solder with copper addition depends on the copper content and reaches 167 to 187 MPa for Al7075 joint and 136.5 MPa for Cu joint.
Article
Engineering, Manufacturing
Xiong Yi, Ruhua Zhang, Xiaowu Hu
Summary: The study investigated the effects of Cu-foam sheets and ultrasound-assisted soldering time on the microstructure and mechanical properties of solder joints. Results showed that the grain refinement caused by ultrasonic cavitation significantly improved the shear strength of the solder joints, and changed the fracture behavior of solder joints.
JOURNAL OF MANUFACTURING PROCESSES
(2021)
Article
Crystallography
Jiachen Xu, Yucan Fu, Xiaoxiao Zhou, Junqian Zhang, Songbai Xue
Summary: This study investigated the effects of high-temperature aging on the microstructure and mechanical properties of SnPbSb/Cu solder joints. It was found that high-temperature aging led to coarsening of the Sn-rich phase and Pb-rich phase in the solder, as well as changes in the structure of the interfacial intermetallic compound layer. High-temperature aging also significantly deteriorated the mechanical properties of the solder joints.
Article
Materials Science, Multidisciplinary
Min-Seong Jeong, Dong-Hwan Lee, Hyeon-Tae Kim, Jeong-Won Yoon
Summary: In this study, the authors compared and evaluated the reliability of laser soldering and conventional reflow soldering in flexible wearable devices. The results showed that, under certain conditions, laser soldering can provide better long-term reliability.
MATERIALS CHARACTERIZATION
(2022)
Article
Engineering, Electrical & Electronic
Ehsan H. Sabbar, Hazim A. Al-Zubaidi, Amer K. Aljumaili, Mustafa H. Al-Jumaili, Ahmed I. Al-Jumaili, Hussein Alsheakh
Summary: This paper investigates the influence of silver (Ag) content on the microstructure and intermetallic compound (IMC) in Sn-Ag-Cu solder joints, and the effects of Ag addition on the mechanical properties of SAC solder joints. The results show that increasing the Ag content leads to an increase in the number of Ag3Sn precipitates and eutectic area, significantly enhancing the mechanical properties of SAC samples.
MICROELECTRONICS RELIABILITY
(2023)
Article
Metallurgy & Metallurgical Engineering
Ming Wu, Shan-lin Wang, Li-meng Yin, Yu-hua Chen, Min Hong, Wen-jun Sun, Zong-xiang Yao, Jia-ming Ni, Peng Lu, Ti-ming Zhang, Ji-lin Xie
Summary: The oxidation behavior and kinetics of intermetallic compound (IMC) growth in SAC305/Cu solder joints were investigated using an electromagnetic induction heating device. The results show that rapid thermal shock leads to oxidation of the solder joint, exacerbated by the presence of internal Cu6Sn5 IMC. The growth of Cu6Sn5 layer is controlled by grain boundary diffusion, while Cu3Sn layer growth is controlled by bulk diffusion.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2023)
Article
Materials Science, Multidisciplinary
Peng Xue, Xu Fang, Yongfeng Zhang, Peng He, Songbai Xue, Liujue Wang
Summary: In this paper, the oxidation thermodynamics and oxidation kinetics of Au-20Sn solder at various temperatures were analyzed. The critical oxygen partial pressure to form SnO and SnO2 in Au-20Sn solder at 298 K was determined. The reliability test results indicated a decrease in hermeticity of the package device with increasing oxygen content in Au-20Sn solder. Additionally, the measured leakage rate of the packaging device could be lowered below a certain threshold when the oxygen content in Au-20Sn solder is less than 28 ppm after high temperature aging.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Review
Engineering, Electrical & Electronic
Chen Chen, Liang Zhang, Xi Wang, Xiao Lu, Li-li Gao, Meng Zhao, Su-juan Zhong
Summary: This paper focuses on the application of Sn-based lead-free solder in electronic packaging and introduces the method of obtaining composite solders by mixing additional elements. The ultrasonic-assisted connection technology can optimize the structure and performance of joints and has been gradually introduced into soldering. The paper summarizes the application of ultrasonic-assisted soldering in Sn-based solder joints and analyzes the impact of ultrasound on the performance of solder joints.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
Xudong Zhang, Wei Fu, Xiaoguo Song, Zhuolin Li, Weimin Long, Danyang Lin, Yanyu Song, Sujuan Zhong
Summary: This study investigates the bonding of W90 tungsten heavy alloy and AZ31B magnesium alloy using ultrasonic-assisted soldering in atmospheric environment. The wetting behavior of Sn on W90 is improved with the application of ultrasound, but prolonged ultrasonication reduces the joint strength. A semi-coherent interface is formed at the Sn/W interface upon ultrasound.
Article
Materials Science, Multidisciplinary
Hyeon-Tae Kim, Jeong-Won Yoon
Summary: The effects of temperature and ultrasonic-assisted time on the microstructures and mechanical properties of the ENIG/Sn-3.5Ag/ENIG sandwich structure in ultrasonic chip bonding were studied. The bonding was successful under all conditions. The formation of different intermetallic compounds and changes in joint thickness were observed at different temperatures and bonding times.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Zezong Zhang, Xiaowu Hu, Wenjing Chen, Sifan Tan, Bin Chen, Jue Wang, Lan Jiang, Yifan Huang, Guangyu Zhu, Yinshui He, Xiongxin Jiang, Qinglin Li
Summary: This study investigates the influence of thermal gradient (TG) on the microstructure, grain orientations, and shear properties of Cu/SAC305/Cu solder joints. The magnitude of TG is controlled by the thickness of the solder layer. The results show that the introduction of TG leads to asymmetric growth of intermetallic compounds (IMCs) and promotes rapid generation of IMCs at the cold end. The shear properties of TG-treated joints are lower than those of isothermally bonded joints, indicating reduced reliability.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Yan Liu, Wei Cui, Xiulin Ji
Summary: Active element soldering technology can achieve effective bonding between ceramics and metals, but the addition of active elements often results in an increase in the melting point of the solder alloys. In this study, a micro-alloyed reactive solder and ultrasound assistance were used to successfully achieve effective interfacial reaction in soldering ZrO2 ceramics and 304 stainless steel.
Article
Materials Science, Multidisciplinary
Siliang He, Yu -An Shen, Bifu Xiong, Fupeng Huo, Jiahui Li, Jinguo Ge, Zhiliang Pan, Wangyun Li, Chuan Hu, Hiroshi Nishikawa
Summary: This study demonstrates the fluxless soldering behavior of SAC solder/Cu under FA atmosphere. It is found that solid-state Sn steaming promotes the formation of Sn-Cu intermetallic compounds and leads to larger spreading area of solder under FA soldering compared to soldering with flux. The wettability of SAC solder under FA atmosphere can be improved with continuous heating.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Electrical & Electronic
Xinmeng Zhai, Yue Chen, Yuefeng Li, Jun Zou, Mingming Shi, Bobo Yang, Yang Li, Chunfeng Guo, Rongrong Hu, Qijun Bao
Summary: This study investigates the influence of different soldering temperatures on the microstructure and shear behavior of flip-chip LED chips, indicating that solder joints exhibit high shear resistance at 270 degrees Celsius. As aging progresses, the shear strength initially increases and then decreases, with cracks and voids appearing as a result.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Tao Wang, Yufeng Huang, Lun Yang, Yunzhu Ma, Lei Wu, Huanyuan Yan, Yang Liu, Wensheng Liu
Article
Engineering, Electrical & Electronic
Ping Lin, Wensheng Liu, Yunzhu Ma, Yufeng Huang, Siwei Tang
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2020)
Article
Materials Science, Multidisciplinary
Lei Wu, Zhaoji Yu, Chao Liu, Yunzhu Ma, Yufeng Huang, Tao Wang, Lun Yang, Huanyuan Yan, Wensheng Liu
Summary: This study introduces a novel low-pressure sintering process that can densify pre-alloyed aluminum powders effectively, achieving a good balance between plasticity and strength.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Materials Science, Multidisciplinary
Xinyun Duan, Yufeng Huang, Wenyang Liu, Qingshan Cai, Wensheng Liu, Yunzhu Ma
Summary: In this study, W-xTa alloys with different Ta contents were fabricated using the arc-melting method, and the effects of Ta on the microstructure and mechanical properties of the alloys were investigated. The results showed that the addition of Ta could refine the grain size of W alloys and improve their hardness and strength, achieving the best comprehensive mechanical properties.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Lei Zhang, Yufeng Huang, Hua Shu, Baishan Chen, Xun Chen, Yunzhu Ma, Wensheng Liu
Summary: This paper investigates shock-induced spallation in a 90W-Ni-Fe alloy at an ultrahigh tensile strain rate using a superintense ultrafast laser facility. The study reveals a new mode of transcrystalline fracture of tungsten particles due to the formation of nanograins inside the particles during laser shock loading. The results also show that most voids are nucleated inside the tungsten particles rather than at the W/g-(Ni, Fe) matrix-phase interface, contradicting the fracture theory under quasi-static loading.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Mechanical
Xun Chen, Yufeng Huang, Lei Zhang, Hua Shu, Baishan Chen, Yunzhu Ma, Wensheng Liu
Summary: In this study, laser-induced shock technology was used to investigate the shock loading behavior of polycrystalline tungsten at an ultrahigh strain rate. It was found that the fracture behavior of tungsten changed from an intergranular mode under quasistatic conditions to a transgranular-intergranular mixed mode at high strain rates, with an increased proportion of transgranular cleavage. The spall strength of tungsten was positively correlated with the strain rate, reaching 5.86 GPa at a tensile strain rate of 106 s-1. The increased mobility of screw dislocations at high strain rates improved the spall strength and accelerated the expansion of crack nucleation positions, resulting in numerous transgranular fractures.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Lei Zhang, Baishan Chen, Xun Chen, Jingxuan Sun, Yufeng Huang, Wensheng Liu, Yunzhu Ma
Summary: This study investigates the mechanical behavior and microstructural evolution mechanisms of a dual-phase 90W-7Ni-3Fe alloy under quasi-static and dynamic loading. The results show that the yield strength of the alloy is sensitive to strain rate, with a weakening strain hardening effect at higher strain rates due to the adiabatic environment during dynamic loadings. Quasi-static loading leads to the increase of dislocation structure in W particles and deformation twinning in the gamma-(Ni, Fe) phase, resulting in significant strain hardening. On the other hand, thermal softening dominates during plastic flow under dynamic loading.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Yao Wang, Yufeng Huang, Wensheng Liu, Yong Zhang, Jiayi Liu, Wenyang Liu, Yunzhu Ma
Summary: The addition of tantalum to tungsten-nickel-iron alloys can improve their performance, but the diffusion-reaction between nickel and tantalum during high-temperature sintering leads to the formation of various intermetallic compounds that negatively affect the structure and properties of the tungsten alloy. The diffusion of tantalum-nickel is stronger than that of tungsten-nickel at the same temperature. The formation of an effective bond between nickel and tantalum is difficult at temperatures below 1200℃, resulting in the generation of layered NiTa2, NiTa, Ni2Ta, and Ni3Ta phases. At 1400℃, a violent liquid phase diffusion occurs between nickel and tantalum, producing a large amount of NiTa and Ni2Ta phases. The appearance of the NiTa phase in the tungsten alloy significantly reduces its toughness and increases the risk of brittle fracture.
Article
Nanoscience & Nanotechnology
Jingxuan Sun, Lei Zhang, Yufeng Huang, Baishan Chen, Peiyuan Fan, Wensheng Liu, Yunzhu Ma
Summary: This study investigates the use of rotary swaging (RS) as a pretreatment method to improve the penetrating performance of tungsten heavy alloys (WHAs) used in kinetic penetrators. The results show that RS significantly enhances the dynamic penetration strength and adiabatic shear band (ASB) sensitivity of the alloys. It is found that microstructure softening plays a critical role in the initiation of ASB, which is consistent with the rotational dynamic recrystallization (RDR) mechanism.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Jiayi Liu, Yufeng Huang, Wensheng Liu, Yao Wang, Yong Zhang, Yunzhu Ma
Summary: Novel homogeneous and compact W-Ta-Re alloys were fabricated and studied for their microstructure and mechanical properties. The addition of Ta refined the grains and improved the strength and ductility of the alloys. Furthermore, increasing the Ta concentration resulted in smaller grain size, higher yield strength, and higher compressive strength and strain rate.
Article
Chemistry, Physical
Yufeng Huang, Wensheng Liu, Yunzhu Ma, Siwei Tang, Feng Xue, BaiShan Chen, Juan Wang
JOURNAL OF ALLOYS AND COMPOUNDS
(2020)