G.M. Wenger, D.A. Machusak and J.L. Parker
Organic solderability preservative (OSP) coatings are not new. They have been used successfully with aggressive water soluble flux for assembly of through‐hole only PWBs. However…
Abstract
Organic solderability preservative (OSP) coatings are not new. They have been used successfully with aggressive water soluble flux for assembly of through‐hole only PWBs. However, the multiple heating cycles required for mixed technology assembly and use of no‐clean low solids flux (LSF) for wave solder assembly have placed a greater demand on the solderability protection provided by OSPs. Wetting balance and float testing were used to evaluate numerous OSPs as well as the potential for these surface finishes to be used for ‘No‐Clean’ assembly. Although these laboratory evaluations revealed that OSPs are not as robust as SnPb, they did indicate the assembly processes and materials which could work with OSPs. Additional simulated assembly trials with test vehicles confirmed that thick OSP pre‐flux coatings interfere with soldering and that the solderability of surfaces with thin OSPs degrades when heated in an air environment. Since none of the OSPs evaluated outperformed the imidazole currently in use at AT&T, a no‐clean LSF assembly production trial with a mixed technology telecommunication circuit pack was conducted to compare imidazole with hot air solder levelled surfaces. The production trial and laboratory evaluations resulted in the development of an application model. The elements of the application model are not complicated: (1) use thin OSPs, (2) avoid baking, (3) use as aggressive a flux as possible, (4) apply as much flux as possible, (5) apply the flux where you want solder to wet, and (6) use nitrogen inerted processes whenever possible. Combination of these elements has led to the successful implementation of OSPs for no‐clean assembly. Funding for this effort was obtained through the National Center for Manufacturing Sciences (NCMS) Printed Wiring Board Interconnect Program.
This chapter addresses the outcomes of a six-year school–university partnership between a public liberal arts college and a large urban school district. It explores ways that…
Abstract
This chapter addresses the outcomes of a six-year school–university partnership between a public liberal arts college and a large urban school district. It explores ways that partnerships can support teachers and communities to confront assumptions and take ownership of learning. This paper traces the trajectory of teachers and professors engaged in a longitudinal ongoing professional development initiative focused on “Meeting the Needs of Urban Learners” to identify practices that supported the collaboration, and the outcomes of the school–university partnership.
I. Artaki, U. Ray, H.M. Gordon and R.L. Opila
The emergence of new interconnection technologies involving double‐sided surface mounted components has put stronger restrictions on the method of preserving the solderable finish…
Abstract
The emergence of new interconnection technologies involving double‐sided surface mounted components has put stronger restrictions on the method of preserving the solderable finish on printed circuit (PC) boards. The popular Sn/Pb coatings have come under strong scrutiny due to environmental hazards of lead and also because they do not provide flat, planar surfaces for SM assembly. Organic solderability preservative coatings (OSP) are emerging as strong contenders for replacing Sn/Pb surface finishes. Benzotriazole based organic coatings have been successfully used in the past by several electronics manufacturers. However, assembly technologies involving multiple thermal operations have necessitated a fundamental understanding of the thermal stabilities and the mechanism of corrosion protection provided by the OSPs. This paper reports the results of an investigation of the thermal stabilities of two organic corrosion protection coatings. Although both are organic azole based, they operate in two distinct regimes: one forming thin films (∼100 Å) and the other forming thick films (∼5000 Å). The mechanism of surface protection has been studied using direct surface analytical techniques such as X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), scanning transmission electron microscopy (SEM/TEM) and Fourier transform infrared spectroscopy (FT‐IR). The solderability of the copper was measured by wetting balance techniques and correlated to the amount of copper oxidation. The results indicate that, although the thin films provide excellent protection for storage and handling operations, they decompose under heat, thereby causing oxidation of the copper. The thick films appear to withstand multiple thermal cycling. However, the underlying copper substrate can still be oxidised by oxygen diffusion through pores or cracks, or the film may undergo chemical changes that render the copper unsolderable.
Ziqiang Han and William L. Waugh
This chapter provides the foundation for the book. The objective of this chapter is to outline the theme of the book and to provide the context for the chapters that follow…
Abstract
This chapter provides the foundation for the book. The objective of this chapter is to outline the theme of the book and to provide the context for the chapters that follow. Disaster recovery is a challenge for governments and for affected communities, families, and individuals. It is a challenge, because recovery from catastrophic disasters can be much more complicated and elusive than what can be addressed by national and international aid organizations given the time and other resources. The short literature review provides the research context, and the overview of the book describes each of the chapters briefly.
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G.M. Wenger, L.A. Guth and D.A. Dickinson
Non‐corrosive rosin fluxes have historically been used for telephone communications assemblies because they provide a measure of reliability even if the flux is not totally…
Abstract
Non‐corrosive rosin fluxes have historically been used for telephone communications assemblies because they provide a measure of reliability even if the flux is not totally removed from the assembly. While cleaning is not always necessary from a reliability standpoint, testing issues, product appearance, operating performance and customer requirements must also be considered when making the decision whether or not to clean. As the electronics industry packages more and more functionality on less and less real estate, soldering yields need to increase in order for the assembly process to remain profitable. This requires not only attention to the product's design for manufacturing but it may also require aggressive fluxes to be used in the assembly process. When aggressive fluxes are employed, the necessity for cleaning is greatly increased. The particular combination of flux and cleaning option depends on product design, process capabilities, end point requirements, and environmental considerations. Pending restrictions on the production and use of chlorofluorocarbons (CFCs), and the potential for tighter controls on chlorinated solvents and aqueous detergent effluents, are certain to add to the cost of standard processes. For these reasons alternative cleaning processes have been explored. The evaluation and subsequent use of water soluble flux with ‘water only’ cleaning, terpene cleaning of rosin flux residues, low solids flux ‘no‐clean’ wave soldering and ‘no‐clean’ assembly using reflowed rosin based solder pastes within AT&T are reviewed. A user's assessment of aqueous and semi‐aqueous cleaning is presented which indicates that there are acceptable alternatives to CFCs.
As a retired academic, I have written many academic papers over the years. This is not an academic paper; it is a personal account of my experiences in autumn 2007 of six days in…
Abstract
As a retired academic, I have written many academic papers over the years. This is not an academic paper; it is a personal account of my experiences in autumn 2007 of six days in an NHS hospital in Wales. My previous experience of hospitals in the UK consisted of having my tonsils out in 1947 and visiting my husband and parents who were patients in the same hospital over the course of the last years of their lives and of visiting friends in hospitals.
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The purpose of this paper is to address hierarchies in a large program of projects. It explores cultivation of communities of practice (CoP) within a hierarchical client…
Abstract
Purpose
The purpose of this paper is to address hierarchies in a large program of projects. It explores cultivation of communities of practice (CoP) within a hierarchical client organization that manages multi-billion-euro infrastructure programs and projects.
Design/methodology/approach
This paper is based on an exploratory longitudinal case study approach involving action research. In-depth semi-structured interviews, company records, industry reports and observation from a case study in the hierarchical bureaucracy were translated into the language of cognitive maps for software analysis and subsequent interpretation.
Findings
The findings highlight the importance of hierarchy constraints and program management practices in project-based firms. The involvement of senior management in CoP cultivation reinforced the community’s contribution to strategic value creation in the firm under scrutiny.
Research limitations/implications
This paper mobilizes the concepts of boundary spanning and loose coupling as a way of analyzing the role of CoPs in bureaucratic hierarchies to promote learning and knowledge transfer. The results of the study suggest that application of those concepts can contribute to sustainability of CoPs in hierarchical organizations by giving them social space to span horizontal and vertical boundaries.
Practical implications
The authors practically contribute to the field by demonstrating the process and the impact of CoP sponsors’ engagement in their cultivation. This was enabled through the research-oriented action research component. The paper also concludes that cognitive mapping may provide a useful addition to engaged research, potentially simulating and influencing change in practice.
Originality/value
The academic contribution concerns understanding the roles of hierarchies, program management and CoP cultivation in project-based firms. It offers clear guidelines for managers of hierarchical bureaucracies to cultivate CoPs to address hierarchical constraints and how CoPs differ in organizational form.
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Sport is an important economic activity, and understanding the role of teams and managers is necessary, yet managers – specifically their brand personas – have been the subject of…
Abstract
Purpose
Sport is an important economic activity, and understanding the role of teams and managers is necessary, yet managers – specifically their brand personas – have been the subject of limited research. The purpose of this research is to explore the brand persona of a football manager, using Arsène Wenger as a case.
Design/methodology/approach
Due to the exploratory nature of the study, qualitative methods were used to explore the brand-building activity. Media reports and images that centred on Arsène Wenger's words covering a three-year period were analysed. In total, 1364 articles and 23 images were analysed in NVivo, using both a priori and emergent codes.
Findings
The findings show the construction of the brand persona in three main dimensions pertinent to his role as a manager. The first is the performance in the managerial role in which Arsène Wenger is appointed, the second is associated with the person (including emotions and self-expression) and the third is the context (i.e. football) in which the manager operates.
Research limitations/implications
The research focused on one manager while he was managing a premier league club and is limited to England.
Practical implications
While proposing a theoretical model, this study proposes football clubs understand a manager's persona in relation to the club's brand and the interactive effect. The support of the club on the persona is also indicated.
Originality/value
Football managers have received some research attention, but there has been no analysis of their brand personas. This study expands the understanding of the contribution of the manager to the club brand.
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Thomas E. Drabek and David A. McEntire
Research on emergent behavior has been a significant topic within disaster studies. Through a detailed review of the literature we provide background information about this…
Abstract
Research on emergent behavior has been a significant topic within disaster studies. Through a detailed review of the literature we provide background information about this particular branch of disaster sociology. Following a brief discussion of the process by which literature was selected, important trends and areas of debate are discussed. These include the validation of previous findings, an expansion of the discussion on emergent phenomena and a critique of the bureaucratic approach. We conclude with implications for the theory and practice of emergency management.
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The purpose of this paper is to investigate to which extent the concept of communities of practice (CoPs) can be applied to online communities and to explore how organizations can…
Abstract
Purpose
The purpose of this paper is to investigate to which extent the concept of communities of practice (CoPs) can be applied to online communities and to explore how organizations can better utilize online social structures for their knowledge management practice.
Design/methodology/approach
A case study was used to examine an online community with the practice‐and‐identity framework that characterizes conventional CoPs. Qualitative data analysis was conducted primarily on 7,853 messages downloaded from the online community during a six week period.
Findings
The results showed how an online community could manifest the practice and identity characteristics of conventional CoPs as community members actively engaged in their shared practice and identity development while pursuing a joint enterprise. Research limitations/implications – The study was conducted in a single Chinese online community on traveling, which may limit the generalizability of the findings.
Practical implications
This study suggested how organizations can nurture online CoPs. In addition, a hierarchical model was proposed to help organizations identify the appropriate online social structure for their knowledge management purposes. Originality/value – This study empirically verified that CoPs can emerge from online communities and demonstrated that the concept of CoPs can be used to guide knowledge sharing and knowledge creation in online environments.