Search results
1 – 10 of 21Jiacheng Zhou, Jinglin Shi, Dongfan Yin, Lei Xu, Fuwen Zhang, Zhigang Wang, Qiang Hu and Huijun He
This study aims to investigate the impact of indium (In) content on the thermal properties, microstructure and mechanical properties of Sn-3Ag-3Sb-xIn (x = 0, 1, 2, 3, 4, 5 Wt.%…
Abstract
Purpose
This study aims to investigate the impact of indium (In) content on the thermal properties, microstructure and mechanical properties of Sn-3Ag-3Sb-xIn (x = 0, 1, 2, 3, 4, 5 Wt.%) solders to enhance the performance of tin-based solder under demanding conditions and to meet the urgent need for high-reliability microelectronic interconnection materials in emerging sectors such as automotive intelligent technology, 5G communication technology and high-performance computing.
Design/methodology/approach
In this study, Sn-3Ag-3Sb-xIn solder alloys were prepared. The thermal properties of the solder alloys were characterised by differential scanning calorimetry. Subsequently, optical microscopy, scanning electron microscopy, X-ray diffraction and an electron probe X-ray microanalyser were used to analyse the influence of the In content on the microstructure of the solder. The mechanical properties of solder alloys were determined through tensile testing.
Findings
As the In content increased, the melting temperature of the Sn-3Ag-3Sb-xIn solder decreased, accompanied by less nucleation undercooling and an expanded melting range. The incorporation of In led to an enhancement in the yield and tensile strengths of the Sn-3Ag-3Sb-xIn solder alloys, but with a concomitant decrease in plasticity. In comparison to commercial Sn-3.0Ag-0.5Cu solder alloys, the yield strength and tensile strength of the Sn-3Ag-3Sb-3In alloy increased by 8.64 and 21.69 MPa, respectively, while the elongation decreased by 11.48%.
Originality/value
Sn-3Ag-3Sb-3In solder alloy was the most appropriate and expected comprehensive properties. The enhancements will provide substantial assistance and precise data references for the interconnection requirements in high-strength interconnection fields, such as automotive intelligent technology, 5G communication technology and high-performance computing.
Details
Keywords
Jiacheng Zhou, Jinglin Shi, Lei Xu, Fuwen Zhang, Zhigang Wang, Qiang Hu and Huijun He
The reliability of solder joints is closely related to the growth of an intermetallic compound (IMC) layer between the lead-free solder and substrate interface. This paper aims to…
Abstract
Purpose
The reliability of solder joints is closely related to the growth of an intermetallic compound (IMC) layer between the lead-free solder and substrate interface. This paper aims to investigate the growth behavior of the interfacial IMC layer during isothermal aging at 125°C for Sn-3Ag-3Sb-xIn/Cu (x = 0, 1, 2, 3, 4, 5 Wt.%) solder joints with different In contents and commercial Sn-3Ag-0.5Cu/Cu solder joints.
Design/methodology/approach
In this paper, Sn-3Ag-3Sb-xIn/Cu (x = 0, 1, 2, 3, 4, 5 Wt.%) and commercial Sn-3Ag-0.5Cu/Cu solder were prepared for bonding Cu substrate. Then these samples were subjected to isothermal aging for 0, 2, 8, 14, 25 and 45 days. Scanning electron microscopy and transmission electron microscopy were used to analyze the soldering interface reaction and the difference in IMC growth behavior during the isothermal aging process.
Findings
When the concentration of In in the Sn-3Ag-3Sb-xIn/Cu solder joints exceeded 2 Wt.%, a substantial amount of InSb particles were produced. These particles acted as a diffusion barrier, impeding the growth of the IMC layer at the interface. The growth of the Cu3Sn layer during the aging process was strongly correlated with the presence of In. The growth rate of the Cu3Sn layer was significantly reduced when the In concentration exceeded 3 Wt.%.
Originality/value
The addition of In promotes the formation of InSb particles in Sn-3Ag-3Sb-xIn/Cu solder joints. These particles limit the growth of the total IMC layer, while a higher In content also slows the growth of the Cu3Sn layer. This study is significant for designing alloy compositions for new high-reliability solders.
Details
Keywords
Bijuan Yan, Huijun Liang, Minjie Jin, Zhanlong Li and Yong Song
In the vibration reduction field, constrained stand-off layer damping cylindrical shell plays an important role. However, due to the lack of accurate analysis of its damping…
Abstract
Purpose
In the vibration reduction field, constrained stand-off layer damping cylindrical shell plays an important role. However, due to the lack of accurate analysis of its damping characteristics, this hinders its further research and application. Therefore, the purpose of this paper is concerned with an accurate solution for the vibration-damping characteristics of a constrained stand-off-layer damping cylindrical shell (CSDCS) under various classical boundary conditions and conducts a further analysis.
Design/methodology/approach
Based on the Rayleigh–Ritz method and the Hamilton principle, a dynamic model of CSDCS is established. Then the loss factor and the frequency of CSDCS are obtained. The correctness and convergence behavior of the present model are verified by comparing the calculation results with the literature. By using for various classical boundary conditions without any special modifications in the solution procedure, the characteristics of CSDCS with S-S, C-C, C-S, C-F and S-F boundaries are discussed.
Findings
The Rayleigh–Ritz method is effective in handling the problem of CSDCS with different boundaries and an accurate solution is obtained. The boundary conditions have an important influence on the vibration and damping behavior of the CSDCS.
Originality/value
Based on the Rayleigh–Ritz method and Hamilton principle, a dynamic model of CSDCS is established for the first time, and then the loss factor and frequency of CSDCS are obtained. In addition, the effectiveness of adding the stand-off layer between the base shell and the viscoelastic layer is confirmed by discussing the characteristics of CSDCS with S-S, C-C, C-S, C-F and S-F boundaries.
Details
Keywords
Chen Wang, Lincoln C. Wood and Huijun Liang
Various demands and requirements of foreign home-buyers from different background are yet unclear to most of the residential developers. The aim of this study is to blueprint a…
Abstract
Various demands and requirements of foreign home-buyers from different background are yet unclear to most of the residential developers. The aim of this study is to blueprint a fuzzy mapping of psychological phenomena reflected in consumer behavior, and to develop a Fuzzy Analytic Hierarchy Process (Fuzzy-AHP) decision making model to assist residential developers in dealing with potential foreign customers. Through a questionnaire survey in the form of pair wise comparison matrix among 126 expatriates, this study introduces a new approach to assist residential developers dealing with expatriates' preference on house purchase in Malaysia in a simple and efficient way. With this fuzzy mapping, residential developers could utilize psychological phenomena to manipulate expatriates' preference on housing purchase rather than to merely comply passively.
Details
Keywords
Solder joint inspection plays a critical role in various industries, with a focus on integrated chip (IC) solder joints and metal surface welds. However, the detection of tubular…
Abstract
Purpose
Solder joint inspection plays a critical role in various industries, with a focus on integrated chip (IC) solder joints and metal surface welds. However, the detection of tubular solder joints has received relatively less attention. This paper aims to address the challenges of detecting small targets and complex environments by proposing a robust visual detection method for pipeline solder joints. The method is characterized by its simplicity, cost-effectiveness and ease of implementation.
Design/methodology/approach
A robust visual detection method based on the characteristics of pipeline solder joints is proposed. With the improved hue, saturation and value (HSV) color space, the method uses a multi-level template matching approach to first segment the pipeline from the background, and then match the endpoint of the pipeline to accurately locate the solder joint. The proposed method leverages the distinctive characteristics of pipeline solder joints and employs an enhanced HSV color space. A multi-level template matching approach is utilized to segment the pipeline from the background and accurately locate the solder joint by matching the pipeline endpoint.
Findings
The experimental results demonstrate the effectiveness of the proposed solder joint detection method in practical detection tasks. The average precision of pipeline weld joint localization exceeds 95%, while the average recall is greater than 90%. These findings highlight the applicability of the method to pipeline solder joint detection tasks, specifically in the context of production lines for refrigeration equipment.
Research limitations/implications
The precision of the method is influenced by the placement angle and lighting conditions of the test specimen, which may pose challenges and impact the algorithm's performance. Potential avenues for improvement include exploring deep learning methods, incorporating additional features and contextual information for localization, and utilizing advanced image enhancement techniques to improve image quality.
Originality/value
The proposed pipeline solder joint detection method offers a novel and practical approach. The simplicity, cost-effectiveness and ease of implementation make it an attractive choice for detecting pipeline solder joints in different industrial applications.
Details
Keywords
Bayi Cheng, Xinyan Shi, Junwei Gao and Huijun Zhu
The purpose of this paper is to study the profit optimization of manufacturers who provide personalized products to customers, thus avoiding additional operational costs and…
Abstract
Purpose
The purpose of this paper is to study the profit optimization of manufacturers who provide personalized products to customers, thus avoiding additional operational costs and response times in the production process of personalized product design.
Design/methodology/approach
First, the authors present an integrated model for optimizing profit where the design and production of personalized products are both considered. The authors propose the concept of personalization level and four cases of personalization level are considered including top, high, medium and low levels. Polynomial-time optimal rules are provided for each level by analyzing 17 subcases where all possible personalized products are considered. Then, the authors compare the obtained profit of personalized products with the optimal profit of standardized products.
Findings
At low and high levels of personalization, personalized manufacturing is more profitable for specific products with specific characteristics. At the top and middle level of individuation, assuming that the product has certain characteristics, whether the best choice to produce personalized products depends on the level of individuation chosen by customers.
Originality/value
An important decision issue for manufacturers is whether to produce personalized or standardized products. In this study, the authors consider this decision problem and analyze the operational functions of personalized products. The authors hope to provide theoretical support in the operational management of manufacturers offering personalized products.
Details
Keywords
Huijun Gan, Dongsheng Yu, Dongkun Li and He Cheng
The purpose of this paper is to construct a flux-controlled memcapacitor (MC) emulator without grounded restriction with the binary operation ability. The active first-order…
Abstract
Purpose
The purpose of this paper is to construct a flux-controlled memcapacitor (MC) emulator without grounded restriction with the binary operation ability. The active first-order low-pass filter (LPF) and high-pass filter (HPF) circuits are constructed by replacing the capacitor with MC.
Design/methodology/approach
The output saturation of the active device is innovatively adopted to realize the binary operation of MC with two memcapacitance values. By applying the direct current control voltage together with the input signal, the memcapacitance can be controlled, and hence, cut-off frequency of the filters can be adjusted without changing the circuit structure.
Findings
Experiments and simulation results show that the new filter has good frequency selectivity. Both LPF and HPF can change the cut-off frequency by changing the positive and negative control voltage. The experimental and simulation results are in good agreement with the theoretical analysis, which proves the feasibility and validity of the emulator and the filters.
Originality/value
These MC emulators are simple and easy to physically fabricate, which have been increasingly used for experiment. It also provide an effective reference for device miniaturization and low power consumption.
Details
Keywords
The purpose of this paper is to study the effects of the requirement on product quality and refund (return service charge).
Abstract
Purpose
The purpose of this paper is to study the effects of the requirement on product quality and refund (return service charge).
Design/methodology/approach
The authors set a minimum product quality level for platform to study the effects of the minimum product quality level on product quality and refund for risk-neutral sellers and risk-averse sellers, respectively.
Findings
For the risk-neutral sellers whose optimal product quality level is lower than the minimum level will improve the product quality to the minimum required level. However, under a certain condition with the requirement the sellers will increase refund. Similar results are found when uncertainty is incorporated into demand and return quantity. In addition, how the sellers’ optimal refund is affected by market parameters and market volatile factors is discussed. Specially, the correlation between the uncertainty of the demand and the return quantity affects sellers’ optimal decision of return service charge in many ways.
Originality/value
The obtained results can provide operational managers in reality with valuable suggestions in quality management for platform.
Details
Keywords
Outdoor signage, a key aspect of store atmospherics which influence consumer perceptions and behaviour, is largely overlooked in research on restaurants. Studies show that food…
Abstract
Purpose
Outdoor signage, a key aspect of store atmospherics which influence consumer perceptions and behaviour, is largely overlooked in research on restaurants. Studies show that food perceptions relate positively to restaurant choice, but how outdoor signage influences these perceptions is unclear. Hence, the study aims to investigate the effect of signage colour and restaurant name on consumers' attitudes and purchase intentions.
Design/methodology/approach
This study uses a two (signage colour: blue-white vs. red-yellow) by two (restaurant name: typical vs. atypical) experimental design to investigate the impact of two key elements of corporate visual identity – logo colour and corporate name – on consumers’ attitudes (perceptions of food tastiness and healthiness) and purchase intentions. Two-way analysis of covariance, confirmatory factor analysis and PROCESS are used for data analysis.
Findings
There is a main effect of signage colour on consumers’ perceptions of food healthiness and purchase intentions, and restaurant name significantly affects consumers’ purchase intentions. In addition, there is an interaction effect of signage colour and restaurant name on food healthiness and purchase intentions, and food tastiness and healthiness are associated with purchase intentions.
Practical implications
A key managerial insight emerging from this study is that restaurants’ outdoor signage may be manipulated by restaurateurs to enhance consumers’ perceptions of food healthiness and tastiness, as well purchase intentions.
Originality/value
This study adopts a new angle on corporate visual identity and links existing theories with research on restaurant atmospherics, to explore how brands employing national identity symbols leverages consumers’ prior knowledge to enhance the influence of outdoor signage on their food perceptions and purchase intentions.
Details
Keywords
Huijun Tu and Shitao Jin
Due to the complexity and diversity of megaprojects, the architectural programming process often involves multiple stakeholders, making decision-making difficult and susceptible…
Abstract
Purpose
Due to the complexity and diversity of megaprojects, the architectural programming process often involves multiple stakeholders, making decision-making difficult and susceptible to subjective factors. This study aims to propose an architectural programming methodology system (APMS) for megaprojects based on group decision-making model to enhance the accuracy and transparency of decision-making, and to facilitate participation and integration among stakeholders. This method allows multiple interest groups to participate in decision-making, gathers various perspectives and opinions, thereby improving the quality and efficiency of architectural programming and promoting the smooth implementation of projects.
Design/methodology/approach
This study first clarifies the decision-making subjects, decision objects, and decision methods of APMS based on group decision-making theory and value-based architectural programming methods. Furthermore, the entropy weight method and fuzzy TOPSIS method are employed as calculation methods to comprehensively evaluate decision alternatives and derive optimal decision conclusions. The workflow of APMS consists of four stages: preparation, information, decision, and evaluation, ensuring the scientific and systematic of the decision-making process.
Findings
This study conducted field research and empirical analysis on a practical megaproject of a comprehensive transport hub to verify the effectiveness of APMS. The results show that, in terms of both short-distance and long-distance transportation modes, the decision-making results of APMS are largely consistent with the preliminary programming outcomes of the project. However, regarding transfer modes, the APMS decision-making results revealed certain discrepancies between the project's current status and the preliminary programming.
Originality/value
APMS addresses the shortcomings in decision accuracy and stakeholder participation and integration in the current field of architectural programming. It not only enhances stakeholder participation and interaction but also considers various opinions and interests comprehensively. Additionally, APMS has significant potential in optimizing project performance, accelerating project processes, and reducing resource waste.
Details