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1 – 10 of 17
Article
Publication date: 21 September 2022

Yuchen Xiao, Huiyi Tang, Hehe Zhang, Xiaoling Yang, Ling Sun, Yong Xie, Baoan Wu, Baifeng Luan, Weidong Xie and Xinnan Cai

The purpose of this paper is to develop high-performance Au-coated Ag alloy wires (ACAA wires) and demonstrate the effect of Au coating layers on the bonding performance…

Abstract

Purpose

The purpose of this paper is to develop high-performance Au-coated Ag alloy wires (ACAA wires) and demonstrate the effect of Au coating layers on the bonding performance and oxidation resistance for stable and reliable electronic packaging applications.

Design/methodology/approach

ACAA wire with a diameter of approximately 25 µm and Au layer thickness of approximately 100 nm were prepared by the continuous casting, plating and wire drawing method. The bonding performance of the ACAA wires were studied through bonding on 3,535 chips. The oxidation resistance of ACAA wires and Ag alloy wires (AA wires) were comparatively studied by means of chemical oxidation tests, accelerated life tests and electrochemical tests systematically.

Findings

ACAA wires could form axi-symmetrical spherical free air balls with controllable diameter of 1.5∼2.5 times of the wire diameter after electric flame-off process. The ball shear strength of ACAA wire was higher than that of AA wires. Most importantly, because of the surface Au coating layer, the oxidation resistance of ACAA wires was much enhanced.

Research limitations/implications

ACAA wires with different lengths of heat affected zone were not developed in this study, which limited their application with different loop height requirements.

Practical implications

With higher bonding strength and oxidation resistance, ACAA wires would be a better choice than previous reported AA wire in chip packaging which require high stability and reliability.

Originality/value

This paper provides a kind of novel ACAA wire, which possess the merits of high bonding strength and reliability, and show great potential in electronic packaging applications.

Details

Microelectronics International, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1356-5362

Keywords

Content available
Article
Publication date: 28 June 2011

670

Abstract

Details

Soldering & Surface Mount Technology, vol. 23 no. 3
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 11 August 2022

Yanbo Feng, Xiande Wu, Weidong Chen, Yaen Xie, Taihang Yu and Yong Hao

On-orbit assembly technology is a promising research topic in spaceflight field. For purposes of studying the dynamic performance and reducing weight of an on-orbit…

Abstract

Purpose

On-orbit assembly technology is a promising research topic in spaceflight field. For purposes of studying the dynamic performance and reducing weight of an on-orbit assembly satellite structure frame, this paper aims to propose a structural optimization design method based on natural frequency.

Design/methodology/approach

The dynamic stability of the satellite under working condition depends on the mechanical properties of the structure matrix. A global structural optimization model is established, with the objective of mass minimization and the constraints of given natural frequencies and given structure requirements. The structural optimization and improvement design method is proposed using sequential quadratic programming calculation.

Findings

The optimal result of objective function is effectively obtained, and the best combination of structural geometric parameters is configurated. By analyzing the relationship between the structural variables and optimization parameters, the primary and secondary factors to the mass optimization process of the microsatellite satisfying the dynamic performance requirements are obtained, which improves the effectiveness and accuracy of the system optimization design.

Originality/value

This method can coordinate the relation between satellite vibration stability and weight reduction, which provides an effective way for the optimization design of on-orbit assembly microsatellite. It has reference significance for the similar spacecraft framework structure design.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 17 March 2021

Luosong Jin, Weidong Liu, Cheng Chen, Wei Wang and Houyin Long

With the advent of the information age, this paper aims to apply risk analysis theories to study the risk prevention mechanism of information disclosure, thus supporting…

Abstract

Purpose

With the advent of the information age, this paper aims to apply risk analysis theories to study the risk prevention mechanism of information disclosure, thus supporting the green electricity supply.

Design/methodology/approach

This paper conducts a comprehensive evaluation and analysis of the impact of power market transactions, power market operations and effective government supervision, so as to figure out the core risk content of power market information disclosure. Moreover, AHP-entropy method is adopted to weigh different indicators of information disclosure risks for the participants in the electricity market.

Findings

The potential reasons for information disclosure risk in the electricity market include insufficient information disclosure, high cost of obtaining information, inaccurate information disclosure, untimely information disclosure and unfairness of information disclosure.

Originality/value

Some suggestions and implications on risk prevention mechanism of information disclosure in the electricity market are provided, so as to ensure the green electricity supply and promote the electricity market reform in China.

Details

Journal of Enterprise Information Management, vol. 35 no. 2
Type: Research Article
ISSN: 1741-0398

Keywords

Article
Publication date: 7 March 2019

Biao Mei, Weidong Zhu, Yinglin Ke and Pengyu Zheng

Assembly variation analysis generally demands probability distributions of variation sources. However, due to small production volume in aircraft manufacturing, especially…

Abstract

Purpose

Assembly variation analysis generally demands probability distributions of variation sources. However, due to small production volume in aircraft manufacturing, especially prototype manufacturing, the probability distributions are hard to obtain, and only the small-sample data of variation sources can be consulted. Thus, this paper aims to propose a variation analysis method driven by small-sample data for compliant aero-structure assembly.

Design/methodology/approach

First, a hybrid assembly variation model, integrating rigid effects with flexibility, is constructed based on the homogeneous transformation and elasticity mechanics. Then, the bootstrap approach is introduced to estimate a variation source based on small-sample data. The influences of bootstrap parameters on the estimation accuracy are analyzed to select suitable parameters for acceptable estimation performance. Finally, the process of assembly variation analysis driven by small-sample data is demonstrated.

Findings

A variation analysis method driven by small-sample data, considering both rigid effects and flexibility, is proposed for aero-structure assembly. The method provides a good complement to traditional variation analysis methods based on probability distributions of variation sources.

Practical implications

With the proposed method, even if probability distribution information of variation sources cannot be obtained, accurate estimation of the assembly variation could be achieved. The method is well suited for aircraft assembly, especially in the stage of prototype manufacturing.

Originality/value

A variation analysis method driven by small-sample data is proposed for aero-structure assembly, which can be extended to deal with other similar applications.

Article
Publication date: 2 March 2015

Weidong Yang

This paper aims to review the state-owned enterprise (SOE) reform in China and analyzes the role of the Chinese Government in the progress of the SOE reform. It provides…

576

Abstract

Purpose

This paper aims to review the state-owned enterprise (SOE) reform in China and analyzes the role of the Chinese Government in the progress of the SOE reform. It provides suggestions to better guide the direction of further reforms of the SOEs in China.

Design/methodology/approach

This paper reviews the historical path of the SOE reform in China and analyzes the underline policy implication associated with the reform.

Findings

The success of the function-oriented SOE reform depends on the transformation of governmental functions. Only with the linkage of governmental functions reform can we change the existing pattern of economic development, build a solid foundation for the socialist market economy and achieve the final triumph.

Originality/value

This paper provides suggestions to better guide the direction of further reforms of the SOEs in China.

Details

Journal of Entrepreneurship in Emerging Economies, vol. 7 no. 1
Type: Research Article
ISSN: 2053-4604

Keywords

Article
Publication date: 3 June 2019

Hua Liu, Weidong Zhu, Huiyue Dong and Yinglin Ke

To gain accurate support for large aircraft structures by ball joints in aircraft digital assembly, this paper aims to propose a novel approach based on visual servoing…

292

Abstract

Purpose

To gain accurate support for large aircraft structures by ball joints in aircraft digital assembly, this paper aims to propose a novel approach based on visual servoing such that the positioner’s ball-socket can automatically and adaptively approach the ball-head fixed on the aircraft structures.

Design/methodology/approach

Image moments of circular marker labeled on the ball-head are selected as visual features to control the three translational degrees of freedom (DOFs) of the positioner, where the composite Jacobian matrix is full rank. Kalman–Bucy filter is adopted for its online estimation, which makes the control scheme more flexible without system calibration. A combination of proportional control with sliding mode control is proposed to improve the system stability and compensate uncertainties of the system.

Findings

The ball-socket can accurately and smoothly reach its desired position in a finite time (50 s). Positional deviations between the spherical centers of ball-head and ball-socket in the X-Y plane can be controlled within 0.05 mm which meets the design requirement.

Practical implications

The proposed approach has been integrated into the pose alignment system. It has shown great potential to be widely applied in the leading support for large aircraft structures in aircraft digital assembly.

Originality/value

An adaptive approach for accurate support of large aircraft structures is proposed, which possesses characteristics of high precision, high efficiency and excellent stability.

Details

Assembly Automation, vol. 39 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 31 December 2019

Wang Paopao and Jihong Chen

Developing waterway-waterway transfer is an important path for Shanghai's container logistics to innovate service models. Taicang Express Line, a typical case of service…

Abstract

Developing waterway-waterway transfer is an important path for Shanghai's container logistics to innovate service models. Taicang Express Line, a typical case of service model innovation, plays an important role in elevating the standing of Shanghai Port as a container hub port and in developing China (Shanghai) Pilot Free Trade Zone. From the three dominant transfer service models, the waterway-waterway transfer for container logistics of Taicang Express Line has the traits and experience in streamlining logistics processes, innovating logistics clearance models, saving logistics operating costs, offering port logistics cooperation experience for replications and promoting integration of regional port logistics resources. However, it also harbors issues in infrastructure construction, staffing, container resources allocation and transportation, transportation efficiency and policy innovation. In the future, efforts should be invested to strengthening the construction and staffing of port logistics infrastructure, optimizing the container resources allocation and transport of port logistics systems, improving the logistics transportation efficiency of Taicang Express Line, and pushing forward innovation of the synergistic policy mechanism for regional port logistics.

Details

Journal of International Logistics and Trade, vol. 17 no. 4
Type: Research Article
ISSN: 1738-2122

Keywords

Article
Publication date: 8 October 2018

Zeyu Li, Weidong Liu, Le Li, Zhi Liu and Feihu Zhang

Underwater shuttle is widely used in scenarios of deep sea transportation and observation. As messages are transmitted via the limited network, high transmission…

Abstract

Purpose

Underwater shuttle is widely used in scenarios of deep sea transportation and observation. As messages are transmitted via the limited network, high transmission time-delay often leads to information congestion, worse control performance and even system crash. Moreover, due to the nonlinear issues with respect to shuttle’s heading motion, the delayed transmission also brings extra challenges. Hence, this paper aims to propose a co-designed method, for the purpose of network scheduling and motion controlling.

Design/methodology/approach

First, the message transmission scheduling is modeled as an optimization problem via adaptive genetic algorithm. The initial transmission time and the genetic operators are jointly encoded and adjusted to balance the payload in network. Then, the heading dynamic model is compensated for the delayed transmission, in which the parameters are unknown. Therefore, the adaptive sliding mode controller is designed to online estimate the parameters, for enhancing control precision and anti-interference ability. Finally, the method is evaluated by simulation.

Findings

The messages in network are well scheduled and the time delay is thus reduced, which increases the quality of service in network. The unknown parameters are estimated online, and the quality of control is enhanced. The control performance of the shuttle control system is thus increased.

Originality/value

The paper is the first to apply co-design method of message scheduling and attitude controlling for the underwater unmanned vehicle, which enhaces the control performance of the network control system.

Details

Assembly Automation, vol. 38 no. 5
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 9 October 2017

Yulia Panova, Eugene Korovyakovsky, Anton Semerkin, Ville Henttu, Weidong Li and Olli-Pekka Hilmola

This research examines factors that determine the improvement of the Russian supply chain sustainability. The strategic business model incorporates ecological, social and…

Abstract

Purpose

This research examines factors that determine the improvement of the Russian supply chain sustainability. The strategic business model incorporates ecological, social and economic aspects.

Design/methodology/approach

Considering Trans-Siberian Railway as a typical case, the study selected several cases or the parts of the primary rail connection with the affiliation of important neighbouring countries. The study uses quantitative analyses of a variety of size parameters (e.g. volumes of traffic, logistics costs, delivery distance and air pollutants).

Findings

The empirical findings stress that supply chains should favour in the future railway (or intermodal) connections for piggyback and containerised cargo. Herein lays the reason for the examination of all traditional factors affecting the modal choice and their complementation by the parameters to measure sustainability throughout the supply chains. The inclusion of the green practices positively affected the environmental, social and economic performance of the new approach.

Research limitations/implications

This research focuses on the delivery of cargo in containers and semi-trailers within wagons through the overland corridors. Despite the restrictive empirical findings within the national transport system, some elements can be representative of the international supply chains, provided that intermodal services are the most appropriate for the transportation over long distances.

Practical implications

Clients, media and regulatory bodies stress the consideration of environmental aspects at all stages of a global supply chain. Therefore, their adoption into strategic imperatives of local supply chains becomes inevitable.

Originality/value

An assessment of supply chains for longer distance transportation in Russia has not taken sustainability into account within cost analyses.

Details

European Business Review, vol. 29 no. 6
Type: Research Article
ISSN: 0955-534X

Keywords

1 – 10 of 17