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Environmental concerns over hazardous materials being placed in landfills have caused many countries to enact legislation to limit and/or eliminate the use of lead in electronic devices. As a result, the electronics manufacturing industry has undertaken efforts to comply with the legislation. Solder paste is typically used as the joining material between boards and components. The standard solder paste alloy has traditionally been a tin/lead eutectic. Lead‐free should, in theory, have the same functionality as the standard pastes to be utilized as a drop‐in replacement. Typically, solder paste is deposited on to a land pattern site by a stencil printer. In the manufacturing environment, speed and accuracy are desirable characteristics of the stencil printing operation. The purpose of this paper is to determine how fast a selection of lead‐free pastes can be successfully printed.

A representative sample of four lead‐free solder pastes containing different alloys was selected. A series of experiments at an increasing print speed was used to deposit these solder pastes on to printed circuit boards and the printed solder volumes were measured. The maximum print speed for each paste was observed and noted for future use.

Of the four alloys selected for experimentation, one emerged to have the most superior performance in terms of high‐speed printability. The speeds for each paste were observed and noted for future use.

Experimentation was performed in an electronics service provider's environment using equipment and materials that were normally used in production.

The parameters obtained can be used on the manufacturing floor assembling lead‐free products.

The results offer a suggestion (in the form of the parameters that can be utilized) as to what parameters to use in the stencil printing of lead‐free solder paste at high speeds.

Effective teaching, while supplemented by best practice methods and assessments, is rooted in accurate, age-appropriate, and engaging content. As a foundation for history content, elementary educators rely strongly on textbooks and children’s literature, both fiction and non-fiction. While many researchers have examined the historical accuracy of textbook content, few have rigorously scrutinized the historical accuracy of children’s literature. Those projects that carried out such examination were more descriptive than comprehensive due to significantly smaller data pools. I investigate how children’s non-fiction and fiction books depict and historicize a meaningful and frequently taught history topic: Christopher Columbus’s accomplishments and misdeeds. Results from a comprehensive content analysis indicate that children’s books are engaging curricular supplements with age-appropriate readability yet frequently misrepresent history in eight consequential ways. Demonstrating a substantive disconnect between experts’ understandings of Columbus, these discouraging findings are due to the ways in which authors of children’s books recurrently omit relevant and contentious historical content in order to construct interesting, personalized narratives.

This chapter draws on 10 years of ethnographic fieldwork collected in gay bars from three American cities to explore the strategies LGBTQ subcultures deploy to recreate meaningful places within the vestiges of local queer nightlife. As gentrification and social acceptance accelerate the closures of LGBTQ-specific bars and nightclubs worldwide, venues that once served a specific LGBTQ subculture (i.e., leather bars) expand their offerings to incorporate displaced LGBTQ subcultures. Attending to how LGBTQ subcultures might appropriate designated spaces within a gay venue to support community (nightlife complexes), how management and LGBT subcultures temporally circumscribe subcultural practices and traditions to create fleeting, but recurring places (episodic places), and how patrons might disrupt an existing production of place by imposing practices associated with a discrepant LGBTQ subculture(place ruptures), this chapter challenges the notion of “the gay bar” as a singular place catering to a specific subculture. Instead, gay bars increasingly constitute a collection of places within the same space, which may shift depending on its use by patrons occupying the space at any given moment. Beyond the investigation of gay bars, this chapter contributes to the growing sociological literature exploring the multifaceted, unstable, and ephemeral nature of place and place-making in the postmodern city.

This study explored implementation of the middle school concept (MSC) in Illinois middle-level schools, examining relationships between MSC implementation and schools' relative wealth, racial/ethnic composition, and achievement levels.

This quantitative study utilized a sample of 137 Illinois middle-level schools, defined as containing any combination of grades 5–9, including at least two consecutive grade levels and grade 7. Principals completed an online survey, identifying levels of implementation of advisory, teaming with common planning time (CPT), and a composite of both advisory and teaming with CPT.

Schools with high advisory implementation had significantly higher rates of Latinx enrollments. Schools with lower operating expenditures per pupil were significantly less likely to implement advisory or advisory and teaming. Teaming had a significant relationship with composite PARCC test scores, but there was no significant effect for advisory and no significant interaction of advisory and teaming together.

MSC is more expensive to implement, and affluent districts may have the financial means to absorb these costs. Although teaming facilitated improved state test scores, advisory programming did not result in significantly improved scores.

Lack of access to MSC programming in less affluent communities presents an equity issue for low-income students and students of color.

This study contributes to research examining underlying issues of race and poverty and their effects on academic achievement and the effectiveness of the MSC.

The authors examine whether or not applicants and recipients of federal disability insurance (DI) inflate their self-assessed health (SAH) problems relative to others. To do this, the authors employ a technique which uses anchoring vignettes. This approach allows them to examine how various cohorts of the population interpret survey questions associated with subjective self-assessments of health. The results of the analysis suggest that DI participants do inflate the severity of a given health problem, but by a small but significant degree. This tendency to exaggerate the severity of disability problems is much more apparent among those with more education (especially those with a college degree). In contrast, racial minorities tend to underestimate severity ratings for a given disability vignette when compared to their white peers.

The idea of implementing supply chain management (SCM) principles for the construction industry was embraced by construction stakeholders to enhance the sector's performance. The analysis from the literature revealed that the implementation of SCM in the construction industry enhances the industry's value in terms of cost-saving, time savings, material management, risk management and others. The construction supply chain (CSC) can be managed using the pull or push system. This chapter also discusses the origin and proliferation of SCM into the construction industry. The chapter revealed that the concept of SCM has passed through five different eras: the creation era, the use of ERP, globalisation stage, specialisation stage and electronic stage. The findings from the literature revealed that we are presently in the fourth industrial revolution (4IR) era. At this stage, the SCM witnesses the adoption of technologies and principles driven by the 4IR. This chapter also revealed that the practice of SCM in the construction industry is centred around integration, collaboration, communication and the structure of the supply chain (SC). The forms and challenges hindering the adoption of these practices were also discussed extensively in this chapter.

This paper aims to discuss the key factors affecting the quality characteristics, such as the number of solder balls, the spread distance of residual underfill and the completion time of the underfilling.

The Taguchi method is applied to configure the orthogonal table and schedule and execute the experiment. In addition, principal components analysis is used to obtain the points. Then, based on gray relational analysis and the technique for order preference by similarity to ideal solution, the closeness between each quality characteristic and the ideal solution is adopted as the basis for evaluating the quality characteristics.

The optimal parameter combination is proposed, which includes 4 dispensing (11 mg/dispensing), a “half flow” interval state, 80°C preheating module PCB board and an L-shaped dispensing path and verification testing is performed.

For vehicles and handheld electronic products, solder joints that connect electronic components to printed circuit boards may be cracked due to collision, vibration or falling. Consequently, solder balls are closely surrounded and protected by the underfill to improve joint strength and resist external force factors, such as collision and vibration. This paper addresses the defects caused during the second reflow process of a vehicle electronic communication module after the underfilling process.

The standard method to estimate a stochastic frontier (SF) model is the maximum likelihood (ML) approach with the distribution assumptions of a symmetric two-sided stochastic error v and a one-sided inefficiency random component u. When v or u has a nonstandard distribution, such as v follows a generalized t distribution or u has a χ2 distribution, the likelihood function can be complicated or untractable. This chapter introduces using indirect inference to estimate the SF models, where only least squares estimation is used. There is no need to derive the density or likelihood function, thus it is easier to handle a model with complicated distributions in practice. The author examines the finite sample performance of the proposed estimator and also compare it with the standard ML estimator as well as the maximum simulated likelihood (MSL) estimator using Monte Carlo simulations. The author found that the indirect inference estimator performs quite well in finite samples.

This study aims to focus on the passive components of System in Package SiP modules and discusses the geometric pad designs for 01005-sized passive components, the front end design of the hole size and shape of the stencil and the parameters of the stencil sidewall coating, to determine the optimum parameter combination.

This study plans and conducts experiments, where a L8(27) inner orthogonal array is built to consider the control factors, including a L4(23) outer orthogonal array to consider the noise factor, and the experimental data are analyzed by using the technique for order preference by similarity to ideal solution multi-quality analysis method.

The results show that the optimum design parameter level combination is that the solder mask opening pad has no solder mask in the lower part of the component, the pad width is 1.1 times that of the component width, the pad length is 1.75 times that of the electrode tip length, the pad spacing is 5 mil, the stencil open area is 90% of the pad area, the stencil opening corner has a 3 mil chamfer angle, and the stencil sidewall is free of nano-coating.

The parameter design and multi-quality analysis method, as proposed in this study, can effectively develop the layout of passive components on a high-density SiP module substrate, to stabilize the process and increase the production yield.

With an ever-expanding focus on reading and mathematics, many elementary schools have chosen to reduce time previously reserved for social studies. Elementary teachers who understand both the relevance of social studies content and the effectiveness of interdisciplinary teaching regularly incorporate applicable history-based children’s tradebooks in their curricula. Locating developmentally appropriate books is simple. Teaching history using children’s literature can be effective. It can be counterproductive, however, if the selected book is replete with historical misrepresentations. Teaching historical thinking in elementary school is problematic no matter what the teaching tool, and there are few methodological roadmaps for elementary teachers. Here, I first suggest ways for teachers to nurture elementary students’ historical thinking using anecdotes from everyday activities and literature with themes germane to history and multiculturalism. Then, I suggest ways for elementary educators to locate and develop engaging, age-appropriate, and historically accurate curricular supplements. Using literature on Christopher Columbus as a reference point to facilitate young students’ historical thinking, I propose an interdisciplinary approach, discipline-specific historical literacy strategies, and history-themed authentic assessments.