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Article
Publication date: 19 December 2017

Maogong Jiang, Guicui Fu, Bo Wan, Peng Xue, Yao Qiu and Yanruoyue Li

The purpose of this paper is to present a failure analysis of the solder layer in a Darlington power transistor in a TO-3 package.

203

Abstract

Purpose

The purpose of this paper is to present a failure analysis of the solder layer in a Darlington power transistor in a TO-3 package.

Design/methodology/approach

A failed Darlington power transistor in a TO-3 package was examined by different kinds of failure analysis techniques. At first, internal gas analysis was conducted to measure the atmosphere. Then, scanning acoustic microscopy (SAM) was performed to check the quality of the solder layers in the failed device, and the failure location was determined in the solder layer between chip and substrate. Next, the failed device was decapped to observe the defects. After removing the chip from the substrate, energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were applied and the main elemental composition of the solder layer was identified.

Findings

Internal gas analysis indicated that the moisture and oxygen contents exceeded the allowed maximum value. Large areas of voids were found in the solder layer by SAM. The main elemental compositions of the solder layer were identified by scanning electron microscopy and EDS. Furthermore, the valences of the chemical components in the solder layer were identified by XPS. Except for the few simple substances of the initial solder material, the chemical formulae of oxidation products in the solder layer were deduced. In addition, the root causes are also discussed.

Originality/value

This paper focuses on the solder layer failure of a power transistor. Factors such as the presence of oxygen, voids and other factors, which can cause transistor damage, were comprehensively analyzed. The analysis process is worth learning from and the results can be used to improve the reliability of power devices in this kind of package.

Details

Soldering & Surface Mount Technology, vol. 30 no. 1
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 27 October 2021

Yanruoyue Li, Guicui Fu, Bo Wan, Zhaoxi Wu, Xiaojun Yan and Weifang Zhang

The purpose of this study is to investigate the effect of electrical and thermal stresses on the void formation of the Sn3.0Ag0.5Cu (SAC305) lead-free ball grid array (BGA) solder…

202

Abstract

Purpose

The purpose of this study is to investigate the effect of electrical and thermal stresses on the void formation of the Sn3.0Ag0.5Cu (SAC305) lead-free ball grid array (BGA) solder joints and to propose a modified mean-time-to-failure (MTTF) equation when joints are subjected to coupling stress.

Design/methodology/approach

The samples of the BGA package were subjected to a migration test at different currents and temperatures. Voltage variation was recorded for analysis. Scanning electron microscope and electron back-scattered diffraction were applied to achieve the micromorphological observations. Additionally, the experimental and simulation results were combined to fit the modified model parameters.

Findings

Voids appeared at the corner of the cathode. The resistance of the daisy chain increased. Two stages of resistance variation were confirmed. The crystal lattice orientation rotated and became consistent and ordered. Electrical and thermal stresses had an impact on the void formation. As the current density and temperature increased, the void increased. The lifetime of the solder joint decreased as the electrical and thermal stresses increased. A modified MTTF model was proposed and its parameters were confirmed by theoretical derivation and test data fitting.

Originality/value

This study focuses on the effects of coupling stress on the void formation of the SAC305 BGA solder joint. The microstructure and macroscopic performance were studied to identify the effects of different stresses with the use of a variety of analytical methods. The modified MTTF model was constructed for application to SAC305 BGA solder joints. It was found suitable for larger current densities and larger influences of Joule heating and for the welding ball structure with current crowding.

Details

Soldering & Surface Mount Technology, vol. 34 no. 3
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 June 2005

John Overby, Mike Rayburn, David C. Wyld and Kevin Hammond

Epidemiologists are concerned the next deadly global cognition will be a new kind of deadly flu which humans have no resistance. Since the 1960s, their alarm has been focused on a…

1140

Abstract

Epidemiologists are concerned the next deadly global cognition will be a new kind of deadly flu which humans have no resistance. Since the 1960s, their alarm has been focused on a bird (avian) virus (H5N1). This virus is generally harmless in its host species, but it is extremely deadly when contracted by humans. H5N1 mutates quickly and tends to pick up genes from flu viruses that affect other species. The flu is far more contagious and harder to contain than the SARS (severe acute respiratory syndrome) virus. It is projected that 30‐40 per cent of the population would be infected in a H5N1 flu pandemic, and as many as one‐third would die. The 1918 Spanish flu caused 20 to 50 million deaths world wide. One scientist observed that the 1918 Spanish flu pandemic could have caused civilisation to disappear within a few weeks. Currently, more than 50 million chickens have been slaughtered in eight Asian countries in efforts to curb the spread of avian influenza. This article examines the roots and dangers of the potential avian influenza pandemic, examining the business and social ramifications that could ensue if the worst case scenario occurs.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 17 no. 2
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 20 September 2021

Kazhal Gharibi and Sohrab Abdollahzadeh

To maximize the network total profit by calculating the difference between costs and revenue (first objective function). To maximize the positive impact on the environment by…

818

Abstract

Purpose

To maximize the network total profit by calculating the difference between costs and revenue (first objective function). To maximize the positive impact on the environment by integrating GSCM factors in RL (second objective function). To calculate the efficiency of disassembly centers by SDEA method, which are selected as suppliers and maximize the total efficiency (third objective function). To evaluate the resources and total efficiency of the proposed model to facilitate the allocation resource process, to increase resource efficiency and to improve the efficiency of disassembly centers by Inverse DEA.

Design/methodology/approach

The design of a closed-loop logistics network for after-sales service for mobile phones and digital cameras has been developed by the mixed-integer linear programming method (MILP). Development of MILP method has been performed by simultaneously considering three main objectives including: total network profit, green supply chain factors (environmental sustainability) and maximizing the efficiency of disassembly centers. The proposed model of study is a six-level, multi-objective, single-period and multi-product that focuses on electrical waste. The efficiency of product return centers is calculated by SDEA method and the most efficient centers are selected.

Findings

The results of using the model in a case mining showed that, due to the use of green factors in network design, environmental pollution and undesirable disposal of some electronic waste were reduced. Also, with the reduction of waste disposal, valuable materials entered the market cycle and the network profit increased.

Originality/value

(1) Design a closed-loop reverse logistics network for after-sales services; (2) Introduce a multi-objective multi-echelon mixed integer linear programming model; (3) Sensitivity analysis use Inverse-DEA method to increase the efficiency of inefficient units; (4) Use the GSC factors and DEA method in reverse logistics network.

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Article
Publication date: 1 June 2005

Li‐teh Sun

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American…

828

Abstract

Man has been seeking an ideal existence for a very long time. In this existence, justice, love, and peace are no longer words, but actual experiences. How ever, with the American preemptive invasion and occupation of Afghanistan and Iraq and the subsequent prisoner abuse, such an existence seems to be farther and farther away from reality. The purpose of this work is to stop this dangerous trend by promoting justice, love, and peace through a change of the paradigm that is inconsistent with justice, love, and peace. The strong paradigm that created the strong nation like the U.S. and the strong man like George W. Bush have been the culprit, rather than the contributor, of the above three universal ideals. Thus, rather than justice, love, and peace, the strong paradigm resulted in in justice, hatred, and violence. In order to remove these three and related evils, what the world needs in the beginning of the third millenium is the weak paradigm. Through the acceptance of the latter paradigm, the golden mean or middle paradigm can be formulated, which is a synergy of the weak and the strong paradigm. In order to understand properly the meaning of these paradigms, however, some digression appears necessary.

Details

International Journal of Sociology and Social Policy, vol. 25 no. 6/7
Type: Research Article
ISSN: 0144-333X

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Article
Publication date: 1 December 1999

Chu‐Mei Liu

Outlines the findings of a study into the secondary destination choices of tourists visiting the Philippines. Defines the tourist mega‐system. Looks at the framework and…

4900

Abstract

Outlines the findings of a study into the secondary destination choices of tourists visiting the Philippines. Defines the tourist mega‐system. Looks at the framework and methodology used and attempts to link these with the holistic approach of Jafari regarding tourism structure and stages which the tourists go through.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 11 no. 4
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 17 January 2022

Tingting Jiang, Buyun Yang, Bo Yang, Bo Wu and Guoguang Wan

The environment of international business (IB) and the capabilities of emerging market multinational enterprises (EMNEs) as well as their home countries have changed…

488

Abstract

Purpose

The environment of international business (IB) and the capabilities of emerging market multinational enterprises (EMNEs) as well as their home countries have changed significantly, leading to some new features of liability of origin (LOR). This paper aims to extend the LOR literature by particularly focusing on the LOR of Chinese multinational enterprises (MNEs) and by taking into account the heterogeneity among industries and across individual MNEs.

Design/methodology/approach

Based on the stereotype content model and organizational legitimacy perspective, this study explores how LOR influences Chinese MNEs’ cross-border acquisition completions. Several hypotheses were tested by using a binary logistic regression model with panel data techniques based on data of 780 Chinese MNEs’ acquisition deals between 2008 and 2018.

Findings

The results of this study show that when the competence dimension of China’s LOR is perceived as high in the host country, Chinese MNEs are less likely to complete cross-border acquisitions. Moreover, deals are less likely to be completed when the warmth dimension of China’s LOR is perceived to be low. Global experience and the foreign-listed status of individual Chinese MNEs can alter the relationship between the LOR and deal completions.

Originality/value

This study advances and enriches the LOR research. It shows that a high level of competence in the home country has led to LOR for Chinese MNEs rather than the low level of competence proposed by existing LOR studies; and the LOR for Chinese MNEs is also determined by the perceived low level of warmth in the home country resulting from the geopolitical conflicts between two countries. In addition, the LOR suffered by EMNEs could vary based on certain industry- and firm-level characteristics. The findings of this study provide important practical implications for emerging economy governments and for firms intending to go abroad.

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Article
Publication date: 1 April 2000

Yim‐Yu Wong, Thomas E. Maher, Joel D. Nicholson and Chi‐wen Chen

Assesses the effects of the Asian economic crisis on Taiwan and identifies some reasons why it has been less dramatically affected than other Asian countries. Discusses its actual…

415

Abstract

Assesses the effects of the Asian economic crisis on Taiwan and identifies some reasons why it has been less dramatically affected than other Asian countries. Discusses its actual and planned policies aimed at strengthening the economy further by maintaining currency stability, improving competitive strengths in both hi‐tech industries and manufacturing, entering new export markets, stimulating domestic demand and reforming financial institutions and regulations. Recognizes the political threats it faces but believes that increasing trade with and investment in China has reduced them.

Details

Managerial Finance, vol. 26 no. 4
Type: Research Article
ISSN: 0307-4358

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Article
Publication date: 1 June 1999

George K. Chacko

Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today. Considers the…

10002

Abstract

Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today. Considers the marketing strategies employed, together with the organizational structures used and looks at the universal concepts that can be applied to any product. Uses anecdotal evidence to formulate a number of theories which can be used to compare your company with the best in the world. Presents initial survival strategies and then looks at ways companies can broaden their boundaries through manipulation and choice. Covers a huge variety of case studies and examples together with a substantial question and answer section.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 11 no. 2/3
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 10 June 2022

Hong-Sen Yan, Zhong-Tian Bi, Bo Zhou, Xiao-Qin Wan, Jiao-Jun Zhang and Guo-Biao Wang

The present study is intended to develop an effective approach to the real-time modeling of general dynamic nonlinear systems based on the multidimensional Taylor network (MTN).

90

Abstract

Purpose

The present study is intended to develop an effective approach to the real-time modeling of general dynamic nonlinear systems based on the multidimensional Taylor network (MTN).

Design/methodology/approach

The authors present a detailed explanation for modeling the general discrete nonlinear dynamic system by the MTN. The weight coefficients of the network can be obtained by sampling data learning. Specifically, the least square (LS) method is adopted herein due to its desirable real-time performance and robustness.

Findings

Compared with the existing mainstream nonlinear time series analysis methods, the least square method-based multidimensional Taylor network (LSMTN) features its more desirable prediction accuracy and real-time performance. Model metric results confirm the satisfaction of modeling and identification for the generalized nonlinear system. In addition, the MTN is of simpler structure and lower computational complexity than neural networks.

Research limitations/implications

Once models of general nonlinear dynamical systems are formulated based on MTNs and their weight coefficients are identified using the data from the systems of ecosystems, society, organizations, businesses or human behavior, the forecasting, optimizing and controlling of the systems can be further studied by means of the MTN analytical models.

Practical implications

MTNs can be used as controllers, identifiers, filters, predictors, compensators and equation solvers (solving nonlinear differential equations or approximating nonlinear functions) of the systems of ecosystems, society, organizations, businesses or human behavior.

Social implications

The operating efficiency and benefits of social systems can be prominently enhanced, and their operating costs can be significantly reduced.

Originality/value

Nonlinear systems are typically impacted by a variety of factors, which makes it a challenge to build correct mathematical models for various tasks. As a result, existing modeling approaches necessitate a large number of limitations as preconditions, severely limiting their applicability. The proposed MTN methodology is believed to contribute much to the data-based modeling and identification of the general nonlinear dynamical system with no need for its prior knowledge.

Details

Kybernetes, vol. 52 no. 10
Type: Research Article
ISSN: 0368-492X

Keywords

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