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The purpose of this paper is to investigate the end point of the plasma cleaning process, in order to save valuable production time and also to prevent the destruction of expensive devices through overheating.

Post plasma cleaning analysis using dynamic contact angle (DCA) analysis and video microscope observations have been conducted on plasma treated Entec coated copper, hot air solder levelled (HASL) and electroless nickel immersion gold (ENIG) surfaces in order to determine the effect of surface finish on plasma process times. Post plasma cleaning and lead-free wave soldering analysis of the three surface finishes have been evaluated.

The DCA results indicate that the end-point for plasma cleaning of Entec coated copper is achieved within one to three minutes (indicated by a low contact angle hysteresis). Further cleaning after three minutes may lead to surface degradation and poor solder wettability. This is consistent with the results of the video microscope observations which show well soldered component leads and pads with good solder coverage for copper surface finish treated at a short plasma process time (one minute) and poorly soldered component leads and pads for a surface treated at a long process time (ten minutes). Similar work conducted on HASL and ENIG finishes show better results (well soldered component leads and solder pads) for longer plasma process times of five to ten minutes.

This paper indicates that plasma process time determines the wettability and solderability of the treated samples. It shows that the plasma conditions including the process time must be optimised and characterised for every application in order to avoid damage to expensive devices. The findings also give the confidence to implement plasma cleaning of lead-free (99.3Sn/0.7Cu) solder PCBs for fluxless soldering.

A numerical study on the reliability of soldered interconnects of c-Si solar photovoltaic cells has been conducted.

A three-year data (2012–2014) from outdoor weathering of PV modules was used to generate temperature cycle profiles to serve as thermal loads and boundary conditions for the investigation of the thermo-mechanical response of the soldered interconnects when subjected to real outdoor conditions using finite element analysis (FEA) Software (Ansys. 18.2). Two types of soldered interconnections, namely, Sn60Pb40 and Sn3.8Ag0.7Cu (Pb-free), were modelled in this study.

Life prediction results from accumulated creep energy density damage show that the solder interconnects will achieve maximum life under the 2014 thermal cycle loading. In particular, the Sn60Pb40 solder interconnection is expected to achieve 14,153 cycles (25.85 years) whilst the Pb-free solder interconnection is expected to achieve 9,249 cycles (16.89 years). Additionally, under the test region average (TRA) thermal cycle, the Pb-free and Pb-Sn solder interconnections are expected to achieve 7,944 cycles (13.69 years) and 12,814 cycles (23.4 years), respectively. The study shows that Sn60Pb40 solder interconnections are likely to exhibit superior reliability over the Pb-free solder interconnections at the test site.

This study would be useful to electronics manufacturing industry in the search for a suitable alternative to SnPb solders and also the thermo-mechanical reliability research community and manufacturers in the design of robust PV modules.

The study has provided TRA data/results which could be used to represent the test region instead of a particular year. The study also indicates that more than six thermal cycles are required before any meaningful conclusions can be drawn. Finally, the life of the two types of solders (SnPb and Pb-free) as interconnecting materials for c-Si PV have been predicted for the test region (Kumasi in sub-Saharan Africa).

The purpose of this paper is to evaluate the effect of solder wettability on the thermal performance of a thermo‐electric cooler (TEC) of a 980 nm pump laser module.

In this paper, TEC thermal performance has been evaluated using a heat pump test. The results were compared with scanning acoustic microscopy (C‐SAM) results in order to have a better understanding of the thermal behaviour of the TEC. In the C‐SAM experiments, images were taken at the interfaces between the housing and TEC, as well as at the interfaces between the chip‐on‐carrier (CoC) and TEC.

The heat pump test results indicate a strong correlation with the C‐SAM test results. The C‐SAM observations show good solder joint at the interface between the TEC and housing in the case of the device that yielded a good heat pump test result (11.5°C) and poor solder joints (gross de‐lamination) at the interface between the TEC and housing in the case of the device that yielded a poor heat pump test result (24.4°C). The C‐SAM observations did not show much difference at the interface between the CoC and TEC. The results from this study were used to qualify the post‐vacuum soldered laser pump devices at JDS Uniphase, Plymouth, UK.

The findings presented in this paper indicate that the level of solder wettability at the interfaces between the piece parts impacts the thermal performance of the TEC.

This paper explores the implications of financial inclusion and financial development for the conduct of monetary policy in achieving price stability and economic growth in sub-Saharan Africa (SSA).

The paper employs the system-generalized methods of moment (GMM) estimation technique using panel data spanning 2004 to 2019 and sourced from Databases of (International Monetary Fund's) IMF's Financial Access Survey (FAS), IMF's International Financial Statistics (IFS), World Bank's Global Financial Development Database (GFDD) and World Bank's World Development Indicators (WDI).

The authors find that financial inclusion has a double-edge effect in SSA. That is, it increases economic growth and lowers inflation in SSA. Furthermore, the results show that a simultaneous increase in financial inclusion and financial development have restrictive effects on economic growth. On the evidence provided, the authors conclude that financial inclusion is an important predictor of economic growth and the conduct of monetary policy in the sub-region.

This paper expands and contributes to the frontier of knowledge how financial inclusion is important for the conduct of monetary policy by monetary authorities in achieving its intended objectives in SSA. The paper highlights the need for ongoing enhancement of financial inclusion of many governments in the sub-region to achieving high economic growth and price stability. Thus, there is the need for policy makers to ensure that a more stringent, effective and appropriate policies and measures are put in place to enhance financial inclusion while taking into consideration the extent of financial development in SSA.

The purpose of this paper is to evaluate the effect of nitrogen and air atmospheres on the solderability testing of plasma‐treated hot air solder level (HASL) finish printed circuit boards (PCBs).

In this paper, the soldering performance of plasma‐treated HASL finish PCBs in nitrogen and air atmospheres have been evaluated using the wetting balance technique. The results were compared with the performance of conventionally flux‐treated samples soldered in air and nitrogen atmospheres and non‐flux treated samples soldered in air. Auger chemical analysis results were also compared with the solderability test results in order to obtain a complete profile of the plasma‐treated and non‐treated surfaces.

The results of the auger chemical analysis show high organic (carbon) levels in the control samples and a significant drop in organic levels in the plasma‐treated samples. The significant drop in the level of carbon leads to a decrease in contact angle and an increase in both surface energy and solder wettability. The results indicate that plasma cleaning of PCBs prior to soldering is a viable alternative to the conventional use of flux.

The paper indicates that the soldering performance of plasma‐treated PCBs in air and nitrogen atmosphere are comparable. The findings give the motivation for the use of plasma‐assisted dry cleaning for fluxless soldering.

The purpose of this paper is to study the effect of intermetallic compound (IMC) layer thickness on the shear strength of surface-mount component 1206 chip resistor solder joints.

To evaluate the shear strength and IMC thickness of the 1206 chip resistor solder joints, the test vehicles were conventionally reflowed for 480 seconds at a peak temperature of 240°C at different isothermal ageing times of 100, 200 and 300 hours. A cross-sectional study was conducted on the reflowed and aged 1206 chip resistor solder joints. The shear strength of the solder joints aged at 100, 200 and 300 hours was measured using a shear tester (Dage-4000PXY bond tester).

It was found that the growth of IMC layer thickness increases as the ageing time increases at a constant temperature of 175°C, which resulted in a reduction of solder joint strength due to its brittle nature. It was also found that the shear strength of the reflowed 1206 chip resistor solder joint was higher than the aged joints. Moreover, it was revealed that the shear strength of the 1206 resistor solder joints aged at 100, 200 and 300 hours was influenced by the ageing reaction times. The results also indicate that an increase in ageing time and temperature does not have much influence on the formation and growth of Kirkendall voids.

A proper correlation between shear strength and fracture mode is required.

The IMC thickness can be used to predict the shear strength of the component/printed circuit board pad solder joint.

The shear strength of the 1206 chip resistor solder joint is a function of ageing time and temperature (°C). Therefore, it is vital to consider the shear strength of the surface-mount chip component in high-temperature electronics.

The chapter delves into the intricate relationship among poverty alleviation policies, cultural identities, and community-specific development in the context of sustainable development. Through various case studies, the chapter underscores the need for policies that empower communities and encourage active participation in decision-making processes. It argues that inclusive development should consider local knowledge, traditions, aspirations, and advocates for partnerships between stakeholders to ensure effective and culturally appropriate strategies. The chapter presents the view that recognizing and preserving cultural identities can not only help fight against poverty but also enhance social unity and well-being. In conclusion, the chapter advocates for a paradigm shift in poverty alleviation strategies: Appreciating and leveraging cultural diversity, empowering communities, and embracing a multifaceted approach to development. Through this approach, a holistic and community-specific stance can yield more effective, sustainable, and equitable outcomes in poverty reduction.

This article aims to investigate how institutional characteristics affect the level of financial development of economies collectively and compare between developed and undeveloped economies.

A dynamic panel with 131 countries, including developed and developing ones, was utilized; the estimators of the generalized method of moments system (GMM system) model were selected because they have econometric characteristics more suitable for analysis, providing superior statistical precision compared to traditional linear estimation methods.

The results from the full panel suggest that concrete and well-defined institutions are important for financial development, confirming previous research, with a more limited scope than the present work.

Limitations of this research include the availability of data for all countries worldwide, which would make the research broader and more complete.

A panel of countries was used, divided into developed and developing countries, to analyze the impact of institutional variables on the financial development of these countries, which is one of the differentiators of this work. Another differentiator of this research is the presentation of estimates in six different configurations, with emphasis on the GMM system model in one and two steps, allowing for comparison between results.

The purpose of this paper is to investigate the efficiencies of argon (Ar), oxygen (O₂) and O₂ followed by Ar (O₂→Ar) plasma treatments in terms of contaminant removal and wire bond interfacial adhesion improvement. The aim of this study is to resolve the “lifted ball bond” issue, which is one of the critical reliability checkpoints for light emitting diodes (LEDs) in automotive applications.

Ar, O₂ and O₂→Ar plasma treatments were applied to LED chip bond pad prior to wire bonding process with different treatment durations. Various surface characterization methods and contact angle measurement were then used to characterize the surface properties of these chip bond pads. To validate the improvements of Ar, O₂ and O₂→Ar plasma treatments to the wire bond interfacial adhesion, the chip bond pads were wire bonded and examined with a ball shear test. Moreover, the contact resistance of the wire bond interfaces was also measured by using four-point probe electrical measurements to complement the interfacial adhesion validation.

Surface characterization results show that O₂→Ar plasma treatment was able to remove the contaminant while maintaining relatively low oxygen impurity content on the bond pad surface after the treatment and was more effective as compared with the O₂ and Ar plasma treatments. However, O₂→Ar plasma treatment also simultaneously reduced high-polarity bonds on the chip bond pad, leading to a lower surface free energy than that with the O₂ plasma treatment. Ball shear test and contact resistance results showed that wire bond interfacial adhesion improvement after the O₂→Ar plasma treatment is lower than that with the O₂ plasma treatment, although it has the highest efficiency in surface contaminant removal.

To resolve “lifted ball bond” issue, optimization of plasma gas composition ratios and parameters for respective Ar and O₂ plasma treatments has been widely reported in many literatures; however, the O₂→Ar plasma treatment is still rarely focused. Moreover, the observation that wire bond interfacial adhesion improvement after O₂→Ar plasma treatment is lower than that with the O₂ plasma treatment although it has the highest efficiency in surface contaminant removal also has not been reported on similar studies elsewhere.

The construction industry presents a particularly notable and demanding setting where sexual harassment demands special consideration. With its largely male-dominated workforce, intense work settings and entrenched workplace norms, the construction sector provides a unique backdrop in which the complexities of sexual harassment manifest. The purpose of this study is to investigate the relationship between sexual harassment and employee performance in the construction industry, with a particular focus on examining the mediating roles of psychological distress and employee engagement.

A cross-sectional survey design was utilized to collect data from 188 construction industry professionals. Participants completed validated questionnaires assessing their experiences with sexual harassment, levels of psychological distress, employee engagement and self-reported performance indicators. Partial least square-structural equation modeling (PLS-SEM) was conducted to examine the direct and mediated effects of sexual harassment on employee performance through psychological distress and employee engagement.

The findings reveal a lack of statistical significance in the negative relationship between sexual harassment and employee performance within the construction sector. Furthermore, there was a significant negative relationship between sexual harassment and employee engagement. Employee engagement emerged as a full mediator, buffering the negative effects of harassment on performance and suggesting that engaged employees may be better equipped to cope with and mitigate the impact of harassment.

The study’s findings contribute to understanding workplace dynamics amidst sexual harassment in construction. Work engagement fully mediates the relationship, highlighting the need to prioritize initiatives aimed at enhancing employee engagement, such as promoting a supportive and fostering open communication channels between management and employees, can mitigate the occurrence and negative impacts of sexual harassment on employee performance. Continuous monitoring of engagement levels is crucial for sustaining positive work environments.

This study contributes to the existing literature by providing quantitative evidence of the relationship between sexual harassment and employee performance in the construction industry. By examining the mediating roles of psychological distress and employee engagement, the research offers a deeper understanding of the mechanisms underlying this relationship. The findings underscore the importance of addressing sexual harassment and promoting employee well-being to foster a safe and productive work environment in the construction industry.