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This paper aims to present a new micro‐impact tester developed for characterizing the impact properties of solder joints and micro‐structures at high‐strain rates, for the microelectronic industry, and the results evaluated for different solder ball materials, pad finishes and thermal histories by using this new tester. Knowledge of impact force is essential for quantifying the strength of the interconnection and allows quantitative design against failure. It also allows one‐to‐one comparison with the failure force measured in a standard quasi‐static shear test.

An innovative micro‐impact head has been designed to precisely strike the specimen at high speed and the force and displacements are measured simultaneously and accurately during the impact, from which the failure energy may be calculated.

The paper demonstrates that, peak loads obtained from the impact tests are between 30 and 100 percent higher than those obtained from static shear tests for all combinations of solder alloy and pad finish. The SnPb solder alloy had the maximum energy to failure for all pad finishes. Of all the lead‐free solders, the SnAg solder alloy had the highest energy to failure. Static shearing induces only bulk solder failure for all combinations of solder alloy and pad finish. Impact testing tends to induce bulk solder failure for SnPb solder and a mixture of bulk and intermetallic failure in all the lead‐free solder alloys for all pad finishes. In general, the peak loads obtained for solder mask defined pads are significantly higher than those for non‐SMD (NSMD) pads. The results obtained so far have highlighted the vulnerability of NSMD pads to drop impact.

The work provides a new solution to the microelectronics industry for characterizing the impact properties of materials and micro‐structures and provides an easy‐to‐use tool for research or process quality control.

The new micro‐impact tester developed is able to perform solder ball shear testing at high speeds, of up to 1,000 mm/s, and to obtain fracture characteristics similar to those found in drop impact testing using the JEDEC board level testing method JESD22‐B111 – but without the complexity of preparing specialized boards. This is not achievable using standard low‐speed shear testers.

The purpose of this paper is to present a novel high speed impact testing method for evaluating the effects of low temperatures on eutectic and lead‐free solder joints. Interfacial cracking failure of Sn‐based and Pb‐free solders at subzero temperatures is of significant concern for electronic assemblies that operate in harsh environments.

This paper presents a newly designed low temperature control system coupled with an Instron micro‐impact testing machine, which offers a package level test for solder bumps, and that is used at subzero temperature ranges as low as −40°C. This study examined the failure characteristics of 63Sn‐37Pb (Sn37Pb) and 96.5Sn‐3Ag‐0.5Cu (SAC305) solder joints at temperatures ranging from room temperature (R.T.) to −40°C, and at impact speeds of 1 m/s.

Three types of failure mode were identified: M1 interfacial fracture with no residual solder remaining on the pad (interfacial cracking); M2 interfacial fracture with residual solder persisting on the pad (mixed mode failure); and M3 solder ball fracture (bulk solder cracking). The experimental results indicated that the energy to peak load for both types of solders decreased significantly, by approximately 35 percent to 38 percent when the test temperature was reduced from R.T. to −40°C. In addition, the peak load of the Sn37Pb solder joint increased noticeably with a decreasing test temperature. However, the peak load of the SAC305 specimen remained virtually unchanged with a reduction in the temperature. The Sn37Pb solder joints failed in an M3 failure mode under all the considered testing temperatures. The SAC305 solder joints displayed both M1 and M2 failure modes at R.T.; however, they failed almost exclusively in M1 mode at the lowest test temperature of −40°C.

This paper presents a novel technique for evaluating high‐speed impact strength and energy absorbance of Sn‐based and Pb‐free solders at the chip level within a low temperature control system. To overcome the drawbacks experienced in other studies, this study focused specifically on cryo‐impact testing systems and the performed experimental steps to improve the accuracy of post‐test analysis.

The end of the twentieth century was filled with an ironic mix of panic and fatalism; together with optimism and hope. ‘Digital armageddon’ in the form of the Y2K bug was reportedly on the horizon (Vulliamy, 2000), but as we know, never transpired. If, however, Y2K had materialised and affected technology as predicted, the consequences would have had profound macro and micro impacts – economically, politically, socially and spatially. Cities – with their super-concentration of technological infrastructure, hardware and software – would arguably have endured the brunt of this catastrophe. Had this disaster occurred, its reach would have been well beyond the city, spiralling out from the CBD to the suburbs, rural settlements, jumping national boundaries, and ultimately bringing economic, transport and communication systems to a near halt, rendering day-to-day living experiences unbearable, if not virtually impossible.

Based on the background of enterprise digital transformation, this paper aims to examine the impact of digitization on the cooperative behavior and environmental performance of green technology innovation.

By constructing a model of quantity competition between the two enterprises, this paper examines the impact of digitization on the cooperative behavior and environmental performance of green technology innovation from the micro level. It uses Shanghai and Shenzhen A-share-listed companies as research samples. An unbalanced panel data set from 2011 to 2018 was constructed to empirically test the effect of digital transformation on the environmental performance of enterprises.

The findings reveal the following. First, digital transformation can significantly improve the environmental performance of enterprises. Second, green technological innovation sharing plays an intermediary role between digital transformation and enterprise environmental performance. Third, when the level of digitization is high, the sharing effect of green technology innovation brought about by digital technology is stronger and enterprises tend to carry out cooperative green technology innovation. Lastly, the level of development of regional science and technology finance plays a positive regulatory role in digital transformation and enterprise environmental performance.

This paper first proposes that green technology innovation-sharing is an important mechanism that can significantly improve enterprises' environmental performance. The authors empirically examine the mechanism and analyze the heterogeneity of the impact of digitalization level on enterprises' environmental performance. The authors also discuss the moderating effect of regional technology and finance development levels on the relationship between digitalization and enterprises' environmental performance.

The political influence on the determinants of capital structure has been under-researched for a long time. Taking the turnover of secretary of municipal committee as a political factor in China, this paper studies the effect of local government officials' turnover on firm's capital structure.

Starting with all A-shares listed firms in the Shanghai and Shenzhen Stock Exchanges from 2001 to 2018, this paper implements the OLS estimation, staggered difference-in-difference approach to investigate the effects of political turnover on the choice of capital structure.

The results show that, driven by government officials' turnover, firms will significantly reduce their leverage. When comparing between formal finance (bank loans) and informal finance (payables), the reduction of capital structure is mainly driven by banks, not by suppliers. Furthermore, two possible channels have been investigated. First, the reduction effects are mainly driven by the SOEs when classifying the types of corporate ownership into SOEs and non-SOEs. Second, the reduction effects exist in areas with the more intense government intervention when considering the heterogeneity of the development of institutional environment in provinces.

This paper first contributes to the literature on the determinants of corporate choice on capital structure. Second, this paper enriches the studies on the economic consequences of local government officials' turnover.

Tax risks are common in China but often ignored by enterprises. Determining how to measure tax risks and effectively identify and control influencing factors is the key to the sustainable development of enterprises. This study aims to explore the key factors affecting corporate tax risks and analyze influencing factors from external and internal perspectives.

After selecting a data set comprising 11,503 firm-year observations of Chinese firms in the Shanghai and Shenzhen Stock Exchanges from 2008–2017, this study applied a panel regression model to identify the factors’ impact.

The results indicate that the more standardized the institutional environment and stronger the tax supervision, the lower the tax risks. Taking into account the internal factors of a firm, private companies with political connections have lower tax risks than those without.

This study enriches the literature on the factors affecting tax risks. The conclusion provides significant insights for enterprises to effectively control tax risks and maintain sustainability. The research findings also provide a new perspective for the government to guard against corporate risks and maintain the stable development of the economy.

The purpose of this paper is to study and compare the mechanical properties and machinability characteristics of additive manufactured titanium alloy Ti-6Al-4V with conventionally produced wrought titanium alloy,Ti-6Al-4V. The difference in mechanical properties such as yield strength, ultimate tensile strength, micro hardness, percentage of elongation and their effect on machinability characteristics like cutting forces and surface roughness are studied. It was found that higher strength and hardness of SLM Ti-6Al-4V compared to wrought Ti-6Al-4V owing to its peculiar acicular microstructure significantly affected the cutting forces and surface roughness. High cutting forces and low surface roughness were observed during machining of additive manufactured components compared to its wrought counterpart because of their difference in strength, hardness and ductility.

Mechanical properties like yield strength, ultimate tensile strength, hardness and percentage of elongation and machinability characteristics like cutting forces and surface roughness were studied for both wrought and additive manufactured Ti-6Al-4V.

Mechanical properties like yield strength, ultimate tensile strength and hardness were higher for additive manufactured components as compared to the wrought component. However additive manufactured components significantly lacked in ductility as compared to the wrought parts. Concerning machining, higher cutting forces and lower surface roughness were observed in additive manufactured Ti-6Al-4V compared to the wrought part as a result of differences in mechanical properties of these differently processed materials.

This paper, for the first time, discusses the machining capabilities of additive manufactured Ti-6Al-4V.

Carbon Efficient Practices (CEPs) are gaining momentum due to the serious consequences of climate change. While past studies have focused on the effects of either drivers or barriers to green practices especially in the context of developed countries, relatively little attention has been devoted to the simultaneous effects of drivers and barriers on product redesign, particularly in the context of China. The paper aims to discuss these issues.

Using a blend of the Contextual Interaction Theory and Newton’s second law of motion, this paper proposes a conceptual model that simultaneously examines the impact of CEP drivers and barriers on product redesign and performance.

Structural Equation Modeling (SEM) analysis on a sample of 239 Chinese manufacturing firms indicated that drivers had substantially higher effects on product redesign and performance compared to the influence of other barriers.

Use of Newton’s second law of motion as a theoretical framework for understanding the adoption of CEPs in the context of China is novel. Implications of this pattern of results on academic theory building and practice are offered.

Several frameworks have been developed to map and document scientific societal interaction and impact, each reflecting the specific forms of impact and interaction that characterize different academic fields. The ReAct taxonomy was developed to register data about “productive interactions” and provide an overview of research activities within the social sciences and humanities (SSH). The purpose of the present research is to examine whether the SSH-oriented taxonomy is relevant to the science, technology, engineering and mathematics (STEM) disciplines when clarifying societal interactions and impact, and whether the taxonomy adds value to the traditional STEM impact indicators such as citation scores and H-index.

The research question was investigated through qualitative interviews with nine STEM researchers. During the interviews, the ReAct taxonomy and visual research profiles based on the ReAct categories were used to encourage and ensure in-depth discussions. The visual research profiles were based on publicly available material on the research activities of the interviewees.

The study provided an insight into how STEM researchers assessed the importance of mapping societal interactions as a background for describing research impact, including which indicators are useful for expressing societal relevance and impact. With regard to the differences between STEM and SSH, the study identified a high degree of cohesion and uniformity in the importance of indicators. Differences were more closely related to the purpose of mapping and impact assessment than between scientific fields. The importance of amalgamation and synergy between academic and societal activities was also emphasised and clarified.

The findings highlight the importance of mapping societal activities and impact, and that societal indicators should be seen as inspiring guidelines depending on purpose and use. A significant contribution is the identification of both uniformity and diversity between the main fields of SSH and STEM, as well as the connection between the choice of indicators and the purpose of mapping, e.g. for impact measurement, profiling, or career development.

The work sheds light on STEM researchers' views on research mapping, visualisation and impact assessment, including similarities and differences between STEM and SSH research.