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Article
Publication date: 12 September 2023

Yuzhu Han, Jieshi Chen, Shuye Zhang and Zhishui Yu

This paper aims to investigate the effect of solder composition and roughness on early wetting behavior and interfacial reaction under atmospheric conditions.

Abstract

Purpose

This paper aims to investigate the effect of solder composition and roughness on early wetting behavior and interfacial reaction under atmospheric conditions.

Design/methodology/approach

High-speed photography is used to observe the early wetting and spreading process of the solder on the substrate in real time. The morphology of intermetallic compounds (IMCs) was observed by scanning electron microscopy, and the composition of IMCs micro bumps was determined by energy dispersive spectroscopy.

Findings

With a roughness range of 0.320–0.539 µm, the solder is distributed in an elliptical trilinear pattern along the grinding direction. With a roughness range of 0.029–0.031 µm, the solder spreads in the direction of grinding and perpendicular, forming a perfect circle (except in the case of Sn63Pb37 solder). The effect of three types of solder on early wettability is Sn63Pb37 > Sn96.5Ag3Cu0.5 > Sn. The wetting behavior is consistent with the Rn∼t model. The rapid spreading stage (Stage I) is controlled by the interfacial reaction with n1 values between 2.4 and 4. The slow spreading stage (stage II) is controlled by diffusion with n2 values between 4 and 6.7. The size of Cu6Sn5 formed on a rough substrate is greater than that produced on a smooth substrate.

Originality/value

Investigating the effect of solder composition and roughness on early wettability. This will provide a powerful guide in the field of soft brazing.

Details

Soldering & Surface Mount Technology, vol. 35 no. 5
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 23 September 2021

Jianing Wang, Jieshi Chen, Zhiyuan Zhang, Peilei Zhang, Zhishui Yu and Shuye Zhang

The purpose of this article is the effect of doping minor Ni on the microstructure evolution of a Sn-xNi (x = 0, 0.05 and 0.1 wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as…

Abstract

Purpose

The purpose of this article is the effect of doping minor Ni on the microstructure evolution of a Sn-xNi (x = 0, 0.05 and 0.1 wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment. Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of interfacial layer was different due to the different mechanism of element diffusion of the two substrates. The PC Ni substrate mainly provided Ni atoms through grain boundary diffusion. The Ni3Sn4 phase of the Sn0.05Ni/PC Ni joint was finer, and the diffusion flux of Sn and Ni elements increased, so the Ni3Sn4 layer of this joint was the thickest. The SC Ni substrate mainly provided Ni atoms through the lattice diffusion. The Sn0.1Ni/SC Ni joint increases the number of Ni atoms at the interface due to the doping of 0.1Ni (wt.%) elements, so the joint had the thickest NiSn4 layer.

Design/methodology/approach

The effects of doping minor Ni on the microstructure evolution of an Sn-xNi (x = 0, 0.05 and 0.1 Wt.%)/Ni (Poly-crystal/Single-crystal abbreviated as PC Ni/SC Ni) solder joint during reflow and aging treatment was investigated in this study.

Findings

Results showed that the intermetallic compounds (IMCs) of the interfacial layer of Sn-xNi/PC Ni joints were Ni3Sn4 phase, while the IMCs of Sn-xNi/SC Ni joints were NiSn4 phase. After the reflow process and thermal aging of different joints, the growth behavior of the interfacial layer was different due to the different mechanisms of element diffusion of the two substrates.

Originality/value

In this study, the effect of doping Ni on the growth and formation mechanism of IMCs of the Sn-xNi/Ni (single-crystal) solder joints (x = 0, 0.05 and 0.1 Wt.%) was investigated.

Details

Soldering & Surface Mount Technology, vol. 34 no. 2
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 13 June 2016

Feifei Zhang, Jieshi Chen and Jun Chen

– The purpose of this paper is to analyze theoretically the influence of normal stress on the formability of aluminum alloy sheets in non-linear strain paths.

Abstract

Purpose

The purpose of this paper is to analyze theoretically the influence of normal stress on the formability of aluminum alloy sheets in non-linear strain paths.

Design/methodology/approach

Four loading modes of non-linear strain paths are investigated in detail to consider the effect of normal stress on formability of aluminum alloy sheets.

Findings

Results show that the influence of normal stress in the first stage can be ignored. However, the normal stress in the second stage enhances the formability of aluminum alloy sheets obviously. Besides, the normal stress in the second stage is found to have larger effect on forming limit stress than that in the first stage.

Research limitations/implications

Maybe more experiment data should be obtained to support the theoretical findings.

Originality/value

This current study provides a better understanding of normal stress effect on the formability of aluminum alloy sheets in non-linear strain paths. Since the reacting stage of normal stress play important roles in normal stress effect on the formability of aluminum alloy sheets, the insight obtained in this paper will help to judge the instability of aluminum alloy sheets in complex forming processes with normal stress reacting on the sheet or tube.

Details

Engineering Computations, vol. 33 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Open Access
Article
Publication date: 29 August 2022

Ninghua Sun and Lei Zeng

China's economic transition is essentially the process of China's institutional changes. During the changes, the appearance of institutional innovation is not regular; instead, it…

Abstract

Purpose

China's economic transition is essentially the process of China's institutional changes. During the changes, the appearance of institutional innovation is not regular; instead, it is intermittent and random. The purpose of this paper is to show that the fitful appearance of institutional innovation is the root of China's economic growth and fluctuations.

Design/methodology/approach

This paper constructs a real business cycle (RBC) model introducing the institutional factor expressed in the quantitative form under the dynamic stochastic general equilibrium (DSGE) framework by measuring China's institutional changes quantitatively.

Findings

By comparing the characteristics of the actual economic data with those of the simulated economic data, we find that this RBC model can explain 94.44%, 66.07%, 23.46%, 21.03% and 15.45% of the cyclical fluctuations in output, investment, labor, consumption and capital, respectively.

Originality/value

The impulse response analysis finds that the institutional shocks have a relatively long duration, lasting about 30 years, and decline slowly over time, while technological shocks decline relatively fast, lasting approximately ten years.

Details

China Political Economy, vol. 5 no. 2
Type: Research Article
ISSN: 2516-1652

Keywords

Open Access
Article
Publication date: 23 November 2023

Chi Zhang

This paper aims to establish a theoretical framework that can comprehensively explain the executive compensation in state-owned enterprises (SOEs) within the context of socialism…

Abstract

Purpose

This paper aims to establish a theoretical framework that can comprehensively explain the executive compensation in state-owned enterprises (SOEs) within the context of socialism with Chinese characteristics.

Design/methodology/approach

The author develops a theoretical framework for executive compensation in SOEs from the perspective of Marxist economics and points out that the executives in SOEs are engaged in management labor, and their compensation should adhere to the principle of distribution according to labor contribution.

Findings

Based on this theory, the author posits that the continuous upward trend of executive compensation in SOEs, is consistent with the trend of SOEs' ongoing expansion, which reflects a continuous improvement of SOE executives' management labor in both quality and quantity.

Originality/value

It is necessary to start with Marxist economic theory and scientifically study the issue of SOE executive compensation, adhere to the principle of distribution according to work in the context of a socialist market economy and implement the specific guideline of the Party Central Committee; only in this way can the long-term healthy development of SOEs be promoted continuously.

Article
Publication date: 17 August 2012

Rosa Enn

The purpose of this paper is to draw attention to an indigenous community that lives in the periphery of Taiwan. The Dao on Orchid Island have had to face serious abuse of their…

Abstract

Purpose

The purpose of this paper is to draw attention to an indigenous community that lives in the periphery of Taiwan. The Dao on Orchid Island have had to face serious abuse of their human rights in terms of ecological exploitation and environmental injustice. The article highlights the empowerment of the indigenous group through collective learning. In this process the importance of being represented at both local and international levels is emphasized. Despite the democratization and implemented mechanism to protect indigenous peoples' rights and dignity, the issue of self‐determination and dependency on financial compensation still remains unsolved.

Design/methodology/approach

Data are collected and elaborated primarily using recognized research methods that are common in social anthropology (Bernard). Field research was conducted in 2007, 2008, and 2011 in Taiwan. A variety of interviews and formal and informal conversations formed the basis of data collection. According to qualitative content analysis, concepts and procedures developed by Gläser and Laudel, Bernard, as well as Schmidt were applied.

Findings

The outcomes of the research highlight the need to investigate the dynamic between modern technologies and the fight of vulnerable minorities in multicultural and democratic countries. Collective learning, solidarity, and presence at national and international levels are essential to improve empowerment to gain justice and respect of human rights.

Research limitations/implications

The indigenous Dao were excluded from decision making processes regarding the government's appropriation of land on Orchid Island to be used to store nuclear waste. The Dao gained power due to educational technologies within a local and global network. Although Taiwan promotes its cultural diversity nowadays, social and environmental justice is still a goal to reach.

Originality/value

The paper provides valuable insights of an indigenous community in Taiwan and their struggles against environmental injustice and exploitation. Due to the fieldwork, a unique and authentic picture of the indigenous peoples' situation is offered.

Details

Multicultural Education & Technology Journal, vol. 6 no. 3
Type: Research Article
ISSN: 1750-497X

Keywords

Open Access
Article
Publication date: 29 July 2020

Lin Gui, Zhendong Yin and Huihua Nie

The stability maintenance system has played an essential role in maintaining social stability although it also has brought about social problems worthy of attention. Admittedly…

4295

Abstract

Purpose

The stability maintenance system has played an essential role in maintaining social stability although it also has brought about social problems worthy of attention. Admittedly compensation-based stability maintenance policy can address the appeals of citizens whose rights are infringed and the dissolving effect in the provision of compensation can save the cost of stability maintenance but such stability maintenance system lacks equilibrium.

Design/methodology/approach

The establishment of a strict assessment system for stability maintenance performance can encourage the stability maintenance authorities to eliminate the “fuse effect” as much as possible and ensure the effective implementation of the stability maintenance system. However, the rigorous stability maintenance performance assessment also provides the possibility for profit-driven petitions.

Findings

Due to the continuous accumulation of social dissatisfaction and the lack of stability maintenance equilibrium in the implementation of the compensation-based stability maintenance policy, public governance will fall into a stability maintenance paradox of “greater instability resulting from stability maintenance”.

Originality/value

The provision of sufficient means for the people to protect their interest by implementing measures such as strengthening the rule of law mechanisms is the key to achieve long-term social stability.

Details

China Political Economy, vol. 3 no. 1
Type: Research Article
ISSN: 2516-1652

Keywords

Article
Publication date: 11 May 2020

Kwun-fu Chan

This study aims to examine the problems encountered during the establishment of the Central Police Academy (CPA) under the Nationalist regime from 1936 to 1949. While the…

Abstract

Purpose

This study aims to examine the problems encountered during the establishment of the Central Police Academy (CPA) under the Nationalist regime from 1936 to 1949. While the authoritarian party-state unified the police academies by forceful means, this catalyzed the cleavage between the schools of police studies and resulted in power struggles over police education, intellectual thought, collectivity and even the national reform of police administration. More than narrating the progress of power consolidation, this study attempts to identify the problems underlying the factional strife and to reveal the interwoven pattern of these power struggles, exploring the confusion regarding what the police is, a question that troubled Chinese policemen from the mainland to Taiwan.

Design/methodology/approach

This paper explains the emergence of the factional strife from the beginning of the preliminary growth of the Police Academies in Nanking and Chekiang. It widely makes use of the official archives from Japan Center for Asian Historical Records and Historica Academia to show the dynamic situation in police education and administration. Rather, the official publications of the Police Academies and their affiliated associations reveal the hidden political agenda behind a unified framework as the party-state claimed. Moreover, official gazettes, memorials and newspapers are also used to strengthen the core argument of this study.

Findings

This paper examines the impact of the factional strife between the police leaders Dai Li and Li Shizhen on the CPA from 1936 to 1949. It illustrates that the establishment of the CPA ostensibly unified the nationwide police force but triggered power struggles over the control of the police administration. More importantly, it also shows how the factions strove for larger shares of power under the supreme doctrines that Chiang Kai-shek and the party-state imposed.

Originality/value

The failure of police education to become powerful was a special case among other more typical institutions. The governors coercively merged the police academies and created robust conditions for growth under the shelter of state authority. The police force did not follow the same path of national monopoly as what recent studies found but drifted apart with its vested interests and incompatible beliefs. Hence, the greater the demand for centralized control by the state, the greater the tension of the factional strife.

Details

Social Transformations in Chinese Societies, vol. 16 no. 1
Type: Research Article
ISSN: 1871-2673

Keywords

Open Access
Article
Publication date: 17 November 2022

Yudong Qi and Xi Chu

Currently, China’s economy is in the critical phase of transforming economic development patterns and replacing old growth drivers with new ones. Whether it can successfully…

3635

Abstract

Purpose

Currently, China’s economy is in the critical phase of transforming economic development patterns and replacing old growth drivers with new ones. Whether it can successfully overcome the “middle-income trap” has become a significant issue attracting wide attention.

Design/methodology/approach

Driven by underlying digital technologies such as artificial intelligence, blockchain, cloud computing and big data, the fourth industrial revolution featuring the booming digital economy has provided significant opportunities for China’s economy to “overtake” and overcome the “middle-income trap”. The transformation of economic development pattern, the optimization of industrial structure, and the change of growth drivers, brought by the deep integration of digital and real economies are the keys to leaping over the “middle-income trap”.

Findings

From the supply side, the digital economy can improve the quality and efficiency of the supply side and promote the supply-side structural reform and economic growth from the following three aspects: First, promote the quality, efficiency and diversification of the supply system; second, promote networking, opening-up and synergy in the innovation system and third, promote the socialization, modularization and flexibility of production pattern. From the demand side, the digital economy can boost the new drivers of the “troika” of economic growth consisting of consumption, exports and investment by changing the market investment direction, promoting consumption upgrade and fostering export strengths. However, once these two attributes interact with each other, especially when data is combined with capital, the most adhesive factor in the market economy, a series of new social relations will then be produced based on the technical attribute, resulting in significant adjustments in social relations, involving both positive and negative externalities.

Originality/value

To overcome the “middle-income trap”, it is necessary to adapt to the laws of economic evolution and promote a fundamental change in economic growth drivers; boost the high-quality development of the digital economy by strengthening the support role of data in the digital economy; and accelerate digital industrialization and industrial digitalization to realize the integration of digital and real economies.

Details

China Political Economy, vol. 5 no. 1
Type: Research Article
ISSN: 2516-1652

Keywords

Open Access
Article
Publication date: 14 October 2021

Fan Gao

Poverty alleviation has been a major theme of China's modernization process since the founding of New China. This paper points out that China's poverty alleviation process…

2980

Abstract

Purpose

Poverty alleviation has been a major theme of China's modernization process since the founding of New China. This paper points out that China's poverty alleviation process presents three stylized facts: “Miraculous” achievements of poverty alleviation have been made on a global scale; the poverty alleviation achievements mainly occurred in the high growth stage after reform and opening up; the poverty alleviation process is accompanied by the structural transformation of the urban–rural dual economy.

Design/methodology/approach

Therefore, a logically consistent analytical framework should form among the structural transformation of the dual economy, economic growth and the achievements in poverty alleviation. In logical deduction, the structural transformation of the dual economy affects rural poverty alleviation through the effects of labor reallocation, agricultural productivity improvement, demographic change and fiscal resource allocation.

Findings

The first two refer to economic growth, and the latter two are alleviation policies. The combination of economic growth and poverty alleviation policies is the main cause for poverty alleviation performance. China's empirical evidence can support the four effects by which the structural transformation of the dual economy affects poverty alleviation.

Originality/value

China's socialist system and its economic system transformation after reform and opening up provide an institutional basis for the effects to come into play. After 2020, China's poverty alleviation strategies will enter the “second-half” phase, namely, the phase of solving the problems of relative poverty in urban and rural areas by adopting conventional methods and establishing long-term mechanisms. This requires the facilitation of the reconnection between poverty alleviation strategies and the structural transformation of the dual economy in terms of development ideas and policy directions.

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