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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

Article
Publication date: 21 December 2021

Ting Shang, Xin Hu, Kunhui Ye and Vivian W. Y. Tam

This study aims to map out contractors' thoughts on construction-related environmental recovery as an excuse for deliberately carrying on unsustainable construction.

Abstract

Purpose

This study aims to map out contractors' thoughts on construction-related environmental recovery as an excuse for deliberately carrying on unsustainable construction.

Design/methodology/approach

A typical highway construction project in China was investigated. Textual materials were collected through semistructured interviews. Content analysis was conducted to derive qualitative data from the textual materials.

Findings

The research findings reveal a trend of environmental recovery associated with construction activities. It is found that contractors utilize this trend to maintain unsustainable construction. Furthermore, the effects of environmental recovery equip local governments with a tolerance for environmental degradation, and the environmental tolerance allows contractors to continue unsustainable construction without being discovered.

Originality/value

This paper presents an environmental recovery-based perspective on unsustainable construction and sheds some light on the promotion of sustainable construction.

Details

Engineering, Construction and Architectural Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0969-9988

Keywords

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