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1 – 10 of over 2000Yan Pan, Shuye Zhang, Pengli Zhu and Kyung W. Paik
The study aims to ascertain the influence of solder conductive particle types and substrate widths on the current carrying capability of flex-on-board (FOB) assemblies. By…
Abstract
Purpose
The study aims to ascertain the influence of solder conductive particle types and substrate widths on the current carrying capability of flex-on-board (FOB) assemblies. By comparing Sn58Bi and SAC305 particles and varying substrate widths, the research sought to provide insights into the stability and performance of solder joints under different scenarios, particularly in high-power applications.
Design/methodology/approach
The study used a comprehensive design/methodology, encompassing the investigation of solder conductive particle types (Sn58Bi and SAC305) and substrate widths on the current carrying capability of FOB assembly. Stable solder joints were obtained by manipulating the curing speed of anisotropic conductive films for both particle types. Various tests were conducted, including current carrying capability assessments under differing conditions.
Findings
The study revealed that larger substrate widths yielded higher current carrying capability due to increased contact area and reduced contact resistance. Notably, solder joints remained stable beyond the solder melting temperature due to encapsulation by cured epoxy resin. SAC305 solder joints exhibited superior current carrying capability over Sn58Bi in continuous high-voltage conditions. The results emphasized the stability of SAC305 solder joints and their suitability for robust interconnections in high-power FOB assemblies.
Originality/value
This study contributes by offering a comprehensive assessment of the impact of solder particle types and substrate widths on solder joint performance in FOB assemblies. The finding that SAC305 joints outperform Sn58Bi under continuous high-voltage conditions adds significant value. Moreover, the observation of stable solder joints beyond solder melting temperature due to resin encapsulation introduces a novel aspect to solder joint reliability. These insights provide valuable guidance for designing robust and high-performance interconnections in demanding applications.
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Yan Pan, Taiyu Jin, Xiaohui Peng, Pengli Zhu and Kyung W. Paik
The purpose of this paper was to investigate how variations in the geometry of silicon chips and the presence of surface defects affect their static bending properties. By…
Abstract
Purpose
The purpose of this paper was to investigate how variations in the geometry of silicon chips and the presence of surface defects affect their static bending properties. By comparing the bending radius and strength across differently sized and treated chips, the study sought to understand the underlying mechanics that contribute to the flexibility of silicon-based electronic devices. This understanding is crucial for the development of advanced, robust and adaptable electronic systems that can withstand the rigors of manufacturing and everyday use.
Design/methodology/approach
This study explores the impact of silicon chip geometry and surface defects on flexibility through a multifaceted experimental approach. The methodology included preparing silicon chips of three distinct dimensions and subjecting them to thinning processes to achieve a uniform thickness verified via scanning electron microscopy (SEM). Finite element method (FEM) simulations and a series of four-point bending tests were used to analyze the bending flexibility theoretically and experimentally. The approach was comprehensive, examining both the intrinsic geometric factors and the extrinsic influence of surface defects induced by manufacturing processes.
Findings
The findings revealed a significant deviation between the theoretical predictions from FEM simulations and the experimental outcomes from the four-point bending tests. Rectangular-shaped chips demonstrated superior flexibility, with smaller dimensions leading to an increased bending strength. Surface defects, identified as critical factors affecting flexibility, were analyzed through SEM and atomic force microscopy, showing that etching processes could reduce defect density and enhance flexibility. Notably, the study concluded that surface defects have a more pronounced impact on silicon chip flexibility than geometric factors, challenging initial assumptions and highlighting the need for defect minimization in chip manufacturing.
Originality/value
This research contributes valuable insights into the design and fabrication of flexible electronic devices, emphasizing the significant role of surface defects over geometric considerations in determining silicon chip flexibility. The originality of the work lies in its holistic approach to dissecting the factors influencing silicon chip flexibility, combining theoretical simulations with practical bending tests and surface defect analysis. The findings underscore the importance of optimizing manufacturing processes to reduce surface defects, thereby paving the way for the creation of more durable and flexible electronic devices for future technologies.
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Lina Si, Yan Pan, Xiaoqing Zhang, Jie Wang, Jia Yao, Yanjie Wang, Fengbin Liu and Feng He
This paper aims to clarify the effects of metallic nanoparticles (NPs) additives and room temperature ionic liquids (ILs) on the tribological performance of electric contacts.
Abstract
Purpose
This paper aims to clarify the effects of metallic nanoparticles (NPs) additives and room temperature ionic liquids (ILs) on the tribological performance of electric contacts.
Design/methodology/approach
Tribological properties of copper (Cu) and silver (Ag) NPs as lubricant additives in different lubricants of ILs or polyalphaolefin (PAO) oils under applied electric currents were investigated. After tribological tests, morphologies of worn surfaces were observed; meanwhile, lubrication and anti-wear properties were analyzed.
Findings
The mixture solution of the IL and Cu NPs showed desirable lubrication and anti-wear properties due to the reduction of electrocorrosion and the enhancement of rolling effects of particles in the contact region. The anti-wear performance of Cu NPs is better than that of Ag NPs due to the difference in the particle size. The PAO oil with the Cu NPs additives showed poor lubrication properties due to the low solubility of the particles in the oil. When the direction of applied current was changed, the friction of the lubricant with better conductivity was more stable in the variation trend.
Originality/value
This paper begins with a study of tribological properties of Cu and Ag NPs as lubricant additives in different lubricants of IL or PAO oils under applied electric currents. The authors then propose several methods and possible solutions which could be implemented to improve the tribological performance of electric contacts.
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Yan Pan, Yufan Shang and Richards Malika
The authors explain the conditions under which positive personality traits and work environment factors either interact synergistically or yield diminishing-gains when creative…
Abstract
Purpose
The authors explain the conditions under which positive personality traits and work environment factors either interact synergistically or yield diminishing-gains when creative individuals are in a supportive working environment.
Design/methodology/approach
Data were obtained using a time-lagged design. The final sample includes 350 researchers from 64 scientific research teams.
Findings
The results indicate that the need for cognition is positively associated with individual creativity. Furthermore, this study suggests that perceived organizational support for creativity can complement an individual's need for cognition when it comes to individual creativity. This indicates a synergistic pattern. On the other hand, psychological safety can substitute for an individual's need for cognition when influencing individual creativity. Thus, a diminishing-gains pattern also exists.
Practical implications
The results suggest that when individuals are stuck in environments of low psychological safety, yet perceive higher levels of organizational support for creativity, their levels of creativity can be boosted.
Originality/value
This study is among one of the first to explore a supportive context's complementary or substitution effect on positive personality traits by demonstrating the complementary effect of perceived organizational support for creativity and the substitution effect of psychological safety. This study validates the positive effect of the need for cognition on creativity. This study also enriches the psychological safety literature by showing that psychological safety is not always necessary for individuals with a high need for cognition.
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Yufan Shang, Yan Pan and Malika Richards
Organizations use enterprise social media (ESM) platforms to operate, function, and develop. However, the effectiveness of the use of ESM is inconclusive. This study aims to…
Abstract
Purpose
Organizations use enterprise social media (ESM) platforms to operate, function, and develop. However, the effectiveness of the use of ESM is inconclusive. This study aims to explore the mechanism and boundary conditions of the relationship between employee ESM use and job performance.
Design/methodology/approach
This study uses a 2-wave survey design, with a final sample of 481 employees from a large automobile company.
Findings
The results indicate that ESM use is beneficial and detrimental to job performance. On the one hand, ESM use is positively related to work overload, decreasing job performance. On the other hand, ESM use is positively associated with informational support, increasing job performance. A mediation test revealed that both work overload and informational support mediate the relationship between ESM use and job performance. Furthermore, job autonomy weakens the positive relationship between ESM use and work overload, but strengthens the positive relationship between ESM use and informational support.
Originality/value
This study provides a more balanced view of how ESM use influences job performance by demonstrating the opposing mediating roles of work overload and informational support. Further, this study fills a research gap by considering job characteristics when examining the boundary conditions of ESM use. Third, this study validates the generalization of the job demands-resources model in social media research.
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The Method section of research articles offers an important space for researchers to describe their research processes and research objects they utilize. To understand the…
Abstract
Purpose
The Method section of research articles offers an important space for researchers to describe their research processes and research objects they utilize. To understand the relationship between these research materials and their representations in scientific publications, this paper offers a quantitative examination of the citation contexts of the most frequently cited references in the Method section of the paper sample, many of which belong to the category of research material objects.
Design/methodology/approach
In this research, the authors assessed the extent to which these references appear in the Method section, which is regarded as an indicator of the instrumentality of the reference. The authors also examined how this central measurement is connected to its other citation contexts, such as key linguistic attributes and verbs that are used in citation sentences.
Findings
The authors found that a series of key linguistic attributes can be used to predict the instrumentality of a reference. The use of self-mention phrases and the readability score of the citances are especially strong predictors, along with boosters and hedges, the two measurements that were not included in the final model.
Research limitations/implications
This research focuses on a single research domain, psychology, which limits the understanding of how research material objects are cited in different research domains or interdisciplinary research contexts. Moreover, this research is based on 200 frequently cited references, which are unable to represent all references cited in psychological publications.
Practical implications
With the identified relationship between instrumental citation contexts and other characteristics of citation sentences, this research opens the possibility of more accurately identifying research material objects from scientific references, the most accessible scholarly data.
Originality/value
This is the first large-scale, quantitative analysis of the linguistic features of citations to research material objects. This study offers important baseline results for future studies focusing on scientific instruments, an increasingly important type of object involved in scientific research.
Peer review
The peer review history for this article is available at: 10.1108/OIR-03-2021-0171
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Planning for underground spaces has become an effective way to use central areas in cities given the steady economic growth in China. The development of underground spaces in…
Abstract
Planning for underground spaces has become an effective way to use central areas in cities given the steady economic growth in China. The development of underground spaces in mountainous cities has satisfied the needs of the diversification of the city commercial areas and pedestrian movement. Safety issues exist because these underground spaces were originally used for civil air defense. This study was based on the underground commercial street in Chongqing, which is a typical mountainous city. Based on the results of combined fieldwork and survey, this paper summarized current safety issues, which include the not-fully-open exit, the imbalanced exit location, blocked evacuation routes, and the poor awareness of the potential safety issues. This paper proposed a framework of the safety factors for the underground space and synopsized prevention strategies that are specific to potential disasters in the underground environment. The framework comprises ensuring that the exits are fully open, the underground corridors are kept unblocked, the open space on the street is increased for disaster prevention, and equipment security is maintained and managed. At last, This paper summarized disaster prevention strategies, which include ensuring unimpeded exits, balancing the locations of the exits, avoiding blocks, increasing the disaster prevention square area in the underground space, maintaining and managing the security of the equipment.
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This paper delves into the mechanism of the contingency framework for foreign entry mode decisions and identifies two essential tasks that jointly determine the outcome of the…
Abstract
This paper delves into the mechanism of the contingency framework for foreign entry mode decisions and identifies two essential tasks that jointly determine the outcome of the entry mode decision. It then recognizes a critical weakness in previous research pertaining to the comparison of entry modes along a key decision criterion, the degree of control. Existing studies generally treat equity involvement as the only source of entrant control, while largely ignoring non‐equity sources of control (i.e., bargaining power and trust). Non‐equity sources of control, when underutilized, amount to missed opportunities, increased resource commitments, and heightened risk exposures in foreign markets. Drawing from a pluralism perspective in transaction and relationship governance, the author presents a more integrative method for the ranking of entry modes along the degree of control. The central message is that companies entering foreign markets should make an earnest effort to identify trust and bargaining power situations and fully utilize their control potential in making entry mode decisions.
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Lan Li, Tan Pan, Xinchang Zhang, Yitao Chen, Wenyuan Cui, Lei Yan and Frank Liou
During the powder bed fusion process, thermal distortion is one big problem owing to the thermal stress caused by the high cooling rate and temperature gradient. For the purpose…
Abstract
Purpose
During the powder bed fusion process, thermal distortion is one big problem owing to the thermal stress caused by the high cooling rate and temperature gradient. For the purpose of avoiding distortion caused by internal residual stresses, support structures are used in most selective laser melting (SLM) process especially for cantilever beams because they can assist the heat dissipation. Support structures can also help to hold the work piece in its place and reduce volume of the printing materials. The mitigation of high thermal gradients during the manufacturing process helps to reduce thermal distortion and thus alleviate cracking, curling, delamination and shrinkage. Therefore, this paper aims to study the displacement and residual stress evolution of SLMed parts.
Design/methodology/approach
The objective of this study was to examine and compare the distortion and residual stress properties of two cantilever structures, using both numerical and experimental methods. The part-scale finite element analysis modeling technique was applied to numerically analyze the overhang distortions, using the layer-by-layer model for predicting a part scale model. The validation experiments of these two samples were built in a SLM platform. Then average displacement of the four tip corners and residual stress on top surface of cantilever beams were tested to validate the model.
Findings
The validation experiments results of average displacement of the four tip corners and residual stress on top surface of cantilever beams were tested to validate the model. It was found that they matched well with each other. From displacement and residual stress standpoint, by introducing two different support structure, two samples with the same cantilever beam can be successfully printed. In terms of reducing wasted support materials, print time and high surface quality, sample with less support will need less post-processing and waste energy.
Originality/value
Numerical modeling in this work can be a very useful tool to parametrically study the feasibility of support structures of SLM parts in terms of residual stresses and deformations. It has the capability for fast prediction in the SLMed parts.
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Zhimin Pan, Yu Yan, Yizhou Huang, Wei Jiang, Gao Cheng Ye and Hong Jun Li
The purpose of this paper is to achieve optimal climbing control of the gas-insulated switchgear (GIS) robot, as the authors know that the GIS inspection robot is a kind of…
Abstract
Purpose
The purpose of this paper is to achieve optimal climbing control of the gas-insulated switchgear (GIS) robot, as the authors know that the GIS inspection robot is a kind of artificial intelligent mobile equipment which auxiliary or even substitute human labor drive on the inner wall of the gas-insulated metal enclosed switchgear. The GIS equipment fault inspection and maintenance can be realized through the robot manipulator on the mobile platform and the camera carried on the fuselage, and it is a kind of intelligent equipment for operation. To realize the inspection and operation of the GIS equipment pipeline without blind spots, the robot is required to be able to travel on any wall inside the pipeline, especially the top of the pipeline and both right and left sides of the pipeline, which requires the flexible climbing of the GIS inspection robot. The robot device has a certain adsorption function to ensure that the robot is fully attached to the wall surface. At the same time, the robot manipulator can be used for collision-free obstacle avoidance operation planning in the narrow operation space inside the GIS equipment.
Design/methodology/approach
The above two technologies are the key that the robot completes the GIS equipment inspections. Based on this, this paper focuses on modeling and analysis of the chassis adsorption characteristics for the GIS inspection robot. At the same time, the Denavit Hartenberg (D-H) coordinate model of the robot arm system has been established, and the kinematics forward and inverse solutions of the robot manipulator system have been derived.
Findings
The reachable working space point cloud diagram of the robot manipulator in MATLAB has been obtained based on the kinematics analysis, and the operation trajectory planning of the robot manipulator using the robot toolbox has been obtained. The simulation results show that the robot manipulator system can realize the movement without collision and obstacle avoidance. The space can cover the entire GIS pipeline so as to achieve no blind area operation.
Originality/value
Finally, the GIS inspection robot physical prototype system has been developed through system integration design, and the inspection, maintenance operation experiment has been carried out in the actual GIS equipment. The entire robot system can complete the GIS equipment inspection operation soundly and improve the operation efficiency. The research in this paper has important theoretical significance and practical application value for the optimization design and practical research of the GIS inspection robot system.
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