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Article
Publication date: 22 February 2011

Hannah Koo, Ka‐Yin Chau, Leung‐Chi Koo, Songbai Liu and Shu‐Chuen Tsui

This paper attempts to deploy a systematic and structural approach to examine Macau's strengths and weaknesses and to scan its external opportunities and threats. A fresh way to…

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Abstract

Purpose

This paper attempts to deploy a systematic and structural approach to examine Macau's strengths and weaknesses and to scan its external opportunities and threats. A fresh way to quantify the extent of perceived opportunities and threats is introduced here. This is adopted and modified from the quality management tool box, i.e. the failure mode and effects analysis (FMEA) and success mode and effects analysis (SMEA).

Design/methodology/approach

The internal factors, i.e. its strengths and weaknesses are systematically and structurally gauged using a Likert scale of 0 to 10 (i.e. 0 representing least important or least well performed … to 10 representing most important and best performed).

Findings

Following the matching of internal factors with the external factors in the strengths, weaknesses, opportunities, and threats (SWOT) analysis, a list of meaningful responses is identified as possible strategies for the Macau SAR Government. The SWOT analysis is simple to use yet powerful and flexible in responding to changes in the external environment and should be useful to organizations both in the commercial sector and government machinery.

Originality/value

This innovative and structured strategic formulation approach is useful to both business practitioners and management consultants.

Details

Journal of Strategy and Management, vol. 4 no. 1
Type: Research Article
ISSN: 1755-425X

Keywords

Article
Publication date: 12 June 2017

Dalian Yang, Yilun Liu, Songbai Li, Jie Tao, Chi Liu and Jiuhuo Yi

The aim of this paper is to solve the problem of low accuracy of traditional fatigue crack growth (FCG) prediction methods.

Abstract

Purpose

The aim of this paper is to solve the problem of low accuracy of traditional fatigue crack growth (FCG) prediction methods.

Design/methodology/approach

The GMSVR model was proposed by combining the grey modeling (GM) and the support vector regression (SVR). Meanwhile, the GMSVR model parameter optimal selection method based on the artificial bee colony (ABC) algorithm was presented. The FCG prediction of 7075 aluminum alloy under different conditions were taken as the study objects, and the performance of the genetic algorithm, the particle swarm optimization algorithm, the n-fold cross validation and the ABC algorithm were compared and analyzed.

Findings

The results show that the speed of the ABC algorithm is the fastest and the accuracy of the ABC algorithm is the highest too. The prediction performances of the GM (1, 1) model, the SVR model and the GMSVR model were compared, the results show that the GMSVR model has the best prediction ability, it can improve the FCG prediction accuracy of 7075 aluminum alloy greatly.

Originality/value

A new prediction model is proposed for FCG combined the non-equidistant grey model and the SVR model. Aiming at the problem of the model parameters are difficult to select, the GMSVR model parameter optimization method based on the ABC algorithm was presented. the results show that the GMSVR model has better prediction ability, which increase the FCG prediction accuracy of 7075 aluminum alloy greatly.

Details

Engineering Computations, vol. 34 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 14 September 2012

Peng Xue, Songbai Xue, Yifu Shen, Zhengxiang Xiao, Hong Zhu, Weimin Long and Xinquan Yu

The purpose of this paper is to improve the properties of Sn−9Zn solder, so as to meet the requirements of industrial applications.

Abstract

Purpose

The purpose of this paper is to improve the properties of Sn−9Zn solder, so as to meet the requirements of industrial applications.

Design/methodology/approach

The effects of Praseodymium on property and Sn whisker growth under aging treatment in Sn−9Zn lead‐free solder were investigated.

Findings

The results indicate that with the addition of rare earth Pr, the wettability and mechanical properties of Sn−9Zn solder were improved. The best wettability and comprehensive property of soldered joint is obtained when the content of Pr is 0.08 wt.%. After aging treatment at 150°C for 360 h, the mechanical properties of Sn−9Zn−0.08Pr decreased but are still obviously higher than that of Sn−9Zn. Moreover, when the content of Pr reached 0.1 wt.%, plenty of Sn−Pr compounds were found in the Sn−9Zn solder. The inevitable oxidation of Sn−Pr compounds would cause a high stress accumulated within PrSn3 phases, which would be served as driving force to induce the Sn whisker sprout and growth after aging treatment at 150°C for 120 h to 360 h. Compared with the results in Sn−9Zn−0.5Ga−0.7Pr solder that Sn whisker observed until the addition of Pr reached 0.7 wt.%, it could be inferred that the addition of Ga may react against the sprout of Sn whisker.

Originality/value

It is found that the addition of Pr can improve the properties of solder and avoid Sn whisker growth in the right range and proper conditions. The cost of the solder with added Pr is limited to RMB 2 yuan/kg so it can be widely used in industry.

Details

Soldering & Surface Mount Technology, vol. 24 no. 4
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 21 June 2013

Huan Ye, Songbai Xue, Cheng Chen and Yang Li

The purpose of this paper is to investigate the growth behavior and mechanism of Sn whisker induced by RE addition in Sn‐Zn‐Ga‐Pr solder at ambient condition.

Abstract

Purpose

The purpose of this paper is to investigate the growth behavior and mechanism of Sn whisker induced by RE addition in Sn‐Zn‐Ga‐Pr solder at ambient condition.

Design/methodology/approach

By means of aging treatment, FIB and SEM microstructure analysis, the whisker growth behavior was investigated.

Findings

It was found that the morphologies of tin whisker are changed during air exposure. After 60 days aging, the average length of the longest whiskers could reach up to 70 μm, some whiskers even can grow to a length of 100 μm. It was discussed that the oxidation of Pr‐Sn intermetallics provides driving force for whisker growth.

Originality/value

Tin whisker growth is a complex reliability issue for lead‐free solder. The current research can be helpful in re‐understanding the issue of tin whisker growth as well as an enriched understanding on the effects of REs on lead‐free solders.

Details

Soldering & Surface Mount Technology, vol. 25 no. 3
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 7 June 2022

Wan Yusmawati Wan Yusoff, Norliza Ismail, Nur Farisa Nadia Mohmad Lehan, Azuraida Amat, Ku Zarina Ku Ahmad, Azman Jalar and Irman Abdul Rahman

This paper aims to investigate the effect of different doses of gamma radiation on the micromechanical response (hardness properties and creep behaviour) of 96.5Sn-3.0Ag-0.5Cu…

Abstract

Purpose

This paper aims to investigate the effect of different doses of gamma radiation on the micromechanical response (hardness properties and creep behaviour) of 96.5Sn-3.0Ag-0.5Cu (SAC305) solder alloys.

Design/methodology/approach

SAC305 solder pastes deposited on printed circuit boards (PCBs) were subjected to a reflow soldering process to form soldered samples. The soldered samples were irradiated with a gamma source at different doses (5–50 Gy). Nanoindentation testing was used to determine the hardness properties and creep behaviour after gamma irradiation.

Findings

The results showed that the hardness of SAC305 solder alloys gradually increased up to 15 Gy and then gradually decreased to 50 Gy of gamma irradiation. The highest hardness value (0.37 GPa) was observed on SAC305 solder alloys exposed to 15 Gy irradiation. Hardening of SAC305 solder alloy was suggested to be due to the high defect density induced by the gamma irradiation. Meanwhile, exposure to 50 Gy irradiation resulted in the lowest hardness value, 0.13 GPa. The softening behaviour of SAC305 solder alloy was probably due to the evolution of defect size in the solder joint. In addition, the creep behaviour of the SAC305 solder alloys changed significantly with different gamma irradiation doses. The creep rates were higher at a dose of 10 Gy up to a dose of 50 Gy. Gamma irradiation caused the SAC305 solder alloy to become more ductile compared to the non-irradiated alloy. The stress exponent also showed different deformation mechanisms with varying gamma doses.

Originality/value

Research into the micromechanical properties of solder alloys subjected to gamma irradiation has rarely been reported, especially for Sn-Ag-Cu lead-free solder. Thus, this research provides a fundamental understanding of the micromechanical response (hardness and creep behaviour) of solder, especially lead-free solder alloy, to gamma irradiation.

Details

Soldering & Surface Mount Technology, vol. 35 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

Abstract

Purpose

This study aims to investigate simultaneous power and thermal loading.

Design/methodology/approach

Finite element method simulations coupled with experiments.

Findings

The effects of power cycling have been determined.

Originality/value

This paper aims to testify the combined effects of thermal and power cycling loads on the reliability of solder ball joints with barrel- and hourglass-type geometries in an electronic system. The finite element simulation outcomes showed that the maximum strain energy was accumulated at the edges of barrel-type solder, whereas the hourglass-type was vulnerable at the necking side. It was also found that the hourglass-type solder showed a reliable behavior when the sole thermal cycling was exerted to the electronic system, whereas the barrel-type solder was a better choice under simultaneous application of thermal and power loadings. The experimental results also confirmed the finite element simulation and indicated that the solder joint reliability strongly depends on the geometry of interconnection in different operating conditions. An extensive discussion was presented to shed light on the paramount importance of combined thermal/power cycling on the reliability of solder joints.

Details

Soldering & Surface Mount Technology, vol. 33 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

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