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The impact strength of solder joint under high strain rate was evaluated by board level test method. However, the impact shear test of single solder bump was more convenient and economical than the board level test method. With the miniaturization of solder joints, solder joints were more prone to failure under thermal shock and more attention has been paid to the impact reliability of solder joint. But Pb-free solder joints may be paid too much attention and Sn-Pb solder joints may be ignored.

In this study, thermal shock test between −55°C and 125°C was conducted on Sn-37Pb solder bumps in the BGA package to investigate microstructural evolution and growth mechanism of interfacial intermetallic compounds (IMCs) layer. The effects of thermal shock and ball diameter on the mechanical property and fracture behavior of Sn-37Pb solder bumps were discussed.

With the increase of ball size, the same change tendency of shear strength with thermal shock cycles. The shear strength of the solder bumps was the highest after reflow; with the increase of the number of thermal shocks, the shear strength of the solder bumps was decreased. But at the time of 2,000 cycles, the shear strength was increased to the initial strength. Minimum shear strength almost took place at 1,500 cycles in all solder bumps. The differences between maximum shear strength and minimum shear strength were 9.11 MPa and 16.83 MPa, 17.07 MPa and 15.59 MPa in φ0.3 mm and φ0.4 mm, φ0.5 mm and φ0.6 mm, respectively, differences were increased with increasing of ball size. With similar reflow profile, the thickness of IMC decreased as the diameter of the ball increased. The thickness of IMC was 2.42 µm and 2.17 µm, 1.63 µm and 1.77 µm with increasing of the ball size, respectively.

Pb-free solder was gradually used to replace traditional Sn-Pb solder and has been widely used in industry. Nevertheless, some products inevitably used a mixture of Sn-Pb and Pb-free solder to make the transition from Sn-Pb to Pb-free solder. Therefore, it was very important to understand the reliability of Sn-Pb solder joint and more further research works were also needed.

With continuous concerning on the toxic of element Pb, Pb-free solder was gradually used to replace traditional Sn-Pb solder. However, during the transition period from Sn-Pb to Pb-free solder, mixing of Sn-Pb and Pb-free is inevitable occurred in certain products, and in China where Sn-Pb solder was still used extensively in certain areas especially. Correspondingly, understanding reliability of Sn-Pb solder joints was very important, and further studies were needed.

Thermal shock test between −55°C and 125 °C was conducted on Sn-37Pb solder bumps in the BGA package to investigate the microstructure evolution and the growth mechanism of interfacial intermetallic compound (IMC) layer. The effects of thermal shock on the mechanical property and fracture behavior of Sn-37Pb solder bumps were discussed.

Pb-rich phase was coarsened and voids were increased at first; Pb-rich phase was refined and voids were decreased secondly with the increase of thermal shock cycles; the shear strength of solder bumps was slightly decreased after thermal shock, but was back up to 73.67MPa at 2,000 cycles; interfacial IMCs of solder bumps was from typical scallop-type into smooth, the composition of IMCs was from Cu₆Sn₅ into Cu₆Sn₅ and Cu₃S_n after thermal shock with 1,500 and 2,000 cycles; 20.0 per cent of solder bumps at 1,500 cycles and 9.5 per cent of solder bumps at 2,000 cycles were failure respectively.

Compared with the board level test method, the impact shear test for the single solder bump is more convenient and economical and is actively pursued by the industries. The shear strength of solder bumps was slightly decreased after thermal shock, but was back up to 73.67 MPa at 2,000 cycles; 20.0 per cent of solder bumps at 1,500 cycles and 9.5 per cent of solder bumps at 2,000 cycles were failure.

This paper aims to offer a convenient method to develop an oven recipe for a specific soldering profile in a reflow process. The method is devised to quickly achieve proper profile shape and heating factor Q_η, a measure of success for high reliability of the solder joints reflowed.

An in‐depth analysis of the heating mechanism and some experiments of the reflow soldering process are performed to research on how to realize a specific shape reflow profile were conducted.

Heating mechanism analysis and experiments demonstrate that the combinatorial parameters based method is feasible to do thermal profiling.

The mapping function among a particular configured PCBA, an oven used, a target reflow profile and an optimal range of the heating factor should be further established for fast and reliable production of reflow soldering.

Provides a methodology for designing an oven recipe for reflow soldering production.

An oven recipe can be quickly attained with the approach established in this paper, facilitating the formation of solder joints with high reliability during the reflow soldering process.

The purpose of this paper is to accomplish the low cost mass‐production of flexible radio frequency identification (RFID) tag inlays.

An anisotropic conductive paste (ACP) is prepared by mixing uniform micro‐sized spherical conductive particles, latent curing agent and other additives into a thermoset epoxy resin. RFID tag inlays are assembled with the paste through flip‐chip technology. The microstructural analysis of bonded joints, bond strength testing, and high‐temperature and humidity aging testing are employed to evaluate the performance of the inlays.

It was found that the chips are hard assembled on the antennae by the ACP. Flexible RFID tag inlays assembled using the presented method have good reliability when working under high frequency (13.56 MHz) conditions.

The method presented is a promising new way for packaging flexible RFID tag inlays with ACP. Through the use of flip‐chip technology, large‐scale production is possible with low manufacturing costs.

The paper details a simple way to prepare an anisotropic conductive paste and to assemble flexible RFID tag inlays. The technique uses flip‐chip technology with the paste as the electrical and mechanical interconnection material. It presents a simple and fast method of assembly for flexible RFID tag inlays on a large‐scale with low cost.

An increasing number of users join and become immersed in WeChat official accounts, but many users quit using these services as well. Nevertheless, most of the previous studies mainly focussed on the usage behavior. The purpose of this paper is to fill the gap by examining factors affecting users’ unfollow intentions for WeChat subscriptions in a Chinese context.

Structural equation modeling is used in our study. A field survey with 260 WeChat users is conducted to test the research model and hypotheses.

The results show the following interesting key findings: first, the effect of actual cost on users’ unfollow intentions is larger than the effect of opportunity cost; second, users’ unfollow intentions will decrease with the increase of users’ perceptions of information usefulness; third, the results of the control variables showed that only landing frequency has a negative effect on users’ unfollow intentions; and fourth, users’ demographic differences are also examined in regard to how they may affect users’ unfollow intentions.

First, this paper studies factors influencing users’ unfollow intentions for WeChat subscriptions from a social exchange theory perspective; the authors considered both extraneous factors and users’ internal perception factors potentially affecting users’ unfollow intentions, which has rarely been researched. Furthermore, the authors examined significant differences among users’ demographic characteristics in affecting users’ unfollow intentions. The results of the study provide a more comprehensive understanding of the influencing factors of users’ unfollow intentions.

This study aimed to examine the research hotspots and evolution paths in the field of health information behavior (HIB) in China and abroad, and conduct comparative analysis to better understand its development trajectory globally.

A keyword search of the relevant literature included in the China National Knowledge Infrastructure (CNKI) database and Web of Science (WoS) core collection database was conducted, using the visualized analysis tool CiteSpace V for bibliometric analyses.

The common research hotspots in China and abroad can be divided into related research on HIB, research on its influencing factors and health information research. Among these, health information-seeking behavior has been the focus of domestic and foreign scholars. From the subdivision perspective, the focus of Chinese and foreign research hotspots differs. In terms of evolutionary path, the initial stage of HIB research in China and abroad revolves around health information and health information-seeking behavior, followed by the influencing factors of HIB; however, the research breakthrough point is the reverse. Then, domestic and foreign research was conducted on different types of HIBs. Regarding the selection of research objects, Chinese and foreign research objects were increasingly diversified.

This study also has several limitations. First, the literature sample only selected the literature in the WoS and CNKI databases, and there may be many HIB-related works published in other databases. Therefore, future research should include other databases. Second, in terms of language, this study selected only Chinese and English literature, but in many countries, important research results on certain topics are usually published in native language, and future research should expand the language selection. Third, this study only conducted national and institutional collaboration network analysis, keyword co-occurrence analysis, cluster analysis and timeline chart analysis.

The implication of practice can be divided into the following three points. (1) Analyzing the domestic and foreign literature on HIB and identifying highly cooperative institutions and countries in the field of HIB can reveal the research situation of HIB and help researchers establish new research networks in the future. (2) Analyzing the research hotspots and evolutionary paths of HIB at home and abroad is helpful for quickly understanding the development context of this field and grasping the emerging research directions such as HIB of people in close contact with patients, health information exchange behavior, health information avoidance behavior and health information discontinuation behavior, which can help researchers to explore the future research direction in this field, so as to determine the topic and fill the research gap. (3) Combining the analysis of HIB-related research at home and abroad is helpful for professionals to understand the characteristics and rules of HIB of users, consumers and other groups to further optimize and improve health information services.

Comparing and summarizing the research status of HIB in China and globally, and presenting the findings visually, will help researchers better grasp the research overview and hotspot changes in this field, as well as provide a follow-up reference.

This study aims to examine the relationships among open innovation, organizational ambidexterity and firm performance. One important aspect of open innovation is that it enables a firm to develop its organizational ambidexterity capability and become more efficient in using this capability to improve its performance.

The authors introduce a moderated mediation theoretical framework to reveal the bridging role of organizational ambidexterity in the effect of open innovation on firm performance. The theoretical model is empirically validated using survey data from 215 high-tech firms.

The authors find that open innovation plays a moderating role in the relationship between organizational ambidexterity and firm performance. Furthermore, organizational ambidexterity plays a significant mediating role in the relationship between open innovation and firm performance, and open innovation has a nonlinear, inverse U-shaped moderation effect on the relationship between organizational ambidexterity and firm performance.

This is one of the first studies to undertake a moderated mediation analysis by highlighting the mediating role of organizational ambidexterity and the moderating role of open innovation in influencing firm performance. The authors make a theoretical contribution to the field of open innovation and organizational behavior, and the authors provide concrete and feasible decision-making suggestions to decision makers adopting open innovation.

The empirical results can help high-tech firm managers ascertain the organizational ambidexterity practices that can be employed and determine the level of open innovation to enhance firm performance.

This research provides new insights into whether and how firms can grasp the benefits of organizational ambidexterity to undertake open innovation activities. The findings not only contribute to advancing the mediating effect of organizational ambidexterity but also verify the inverse U-shaped moderation of open innovation in the relationship between organizational ambidexterity and firm performance.

This chapter aims to delineate the indigenous pattern of parental involvement in Taiwan by investigating the effects of specific practices in schools and in the family, such as school selection, school involvement, preparing a study place at home, and providing nutritious food.

We use two waves of data from the Taiwan Youth Project (2000, 2003) to examine how parental involvement varies between dual- and single-earner families, and we further demonstrate how sons and daughters have different access in terms of recognizing their parents’ effort, and how children’s subjective appraisals promote their academic performance with respect to test scores.

We find that dual-earner families have higher incomes, higher educational levels, and have fewer children than single-earner ones. Our multivariate analyses show that parental involvement does increase youngsters’ Basic Competence Test (BCT) score. However, we are unable to find any direct or indirect effects from parental employment status on BCT scores. Further analysis indicates that the relationship between parental school involvement and BCT score is only significant among dual-earner families, but not for the single-earner ones. In addition, our multiple group analysis reveals that sons’ BCT scores are affected more by parents’ school involvement, whereas daughters’ are affected more by special home provision. Our findings from adolescents’ subjective responses imply that sons may be more responsive to a non-familial context in contrast with daughters, who react more positively to familial provision.

The purpose of this paper is to examine the issue of the influential factors of buyer satisfaction and loyalty toward online auction web sites and online auction sellers. Customers' loyalty toward the online auction web site and seller is also explored.

An internet survey is conducted on 221 buyers of online auction.

Loyalty intention toward an online auction seller positively affects a buyer's loyalty intention toward the online auction web site, whereas his/her loyalty intention toward the online auction web site negatively affects his/her loyalty intention toward the online auction seller.

The first is in its cross‐sectional design. Second, this paper examines the antecedents of the online auction web site and the online auction seller in a single country. The findings may have limited generalizability to other countries.

The results of this paper provide less positive news for online auction sellers. Sellers on an online auction web site should be careful in making online auction web site change decisions. Although a seller can secure buyer loyalty intention by providing strong e‐service quality, overall satisfaction and the specific asset investment (SAI), buyers still may not be enthusiastic about moving with the seller to another auction web site.

This paper contributes to comparing the pulling force of the web sites and the sellers, and explains that SAI can affect the buyers through web sites and sellers. There are three parties involved in the model.