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SMT stencil cleaning has traditionally been thought of as a ‘maintenance’ procedure with little or no impact on production. Today, CFC and VOC cleaning processes are being replaced because of environmental concerns, and fine‐pitch and ultra fine‐pitch assemblies are commonplace. These changes in cleaning processes and product specifications have shed new light on the importance of properly cleaning SMT screens and stencils in order to prevent damage to the stencil and potential production‐related problems.This paper takes an unbiased look at the different stencil cleaning processes available through the eyes of an SMT stencil manufacturer. The paper outlines the advantages and disadvantages of using ‘jet spray’ washersvs ‘ultrasonic’ washers, aqueous and semi‐aqueous vssolvent cleaning agents, and the effects of hot wash solutions and hot drying air vsambient wash solutions and drying techniques.Specific criteria evaluated include: cleaning effectiveness of the process; potential adverse effects of the process on the integrity of the stencil; production down‐time and other potential production‐related problems; potential health hazards to users; environmental impact of the process, and waste stream management.Magnified photography is used to demonstrate the relative effectiveness of various cleaning technologies. Third party references of other industry experts, along with the author's own experiences, are cited to support the information provided.

Solder paste printing is the most common method for attaching surface mount devices to printed circuit boards (PCB), and it has been reported that a majority of all assembly defects occur during the stencil printing process. It is also recognized that the solder paste printing process is wholly responsible for the solder joint formation of leadless package technologies such as land grid array (LGA) and quad-flat no-lead (QFN) components and therefore is a determining factor in the long-term reliability of said devices. The aim of this experiment is to determine the acceptable lower limit for solder paste volume deposit tolerances during stencil printing process to ensure both good assembly yield and reliability expectations.

Stencils with modified aperture dimensions at particular locations for LGA and QFN package footprints were designed to vary the solder paste volume deposited during the stencil printing process. Solder paste volumes were measured using solder paste inspection system. Low volume solder paste deposits were generated using the modified stencil designs to evaluate assemble yield. Accelerated thermal cycling (ATC) was used to determine the reliability of the solder joints. Failure analysis was used to determine if the failure was attributed to the low paste volume locations.

Solder joints formed with nominal paste volume survived longer in ATC compared to intentionally low volume joints. Transfer efficiency numbers for both good assembly yield and good reliability are reported for LGA and QFN devices. A lower volume limit is reported for leadless devices that should not significantly affect yield and reliability in thermal cycling.

Very little literature is available on solder paste volume tolerance limits in terms of assembly yield and reliability. Manufacturers often use ±50 or ±30 per cent of stencil aperture volume with no evidence of its effectiveness in determining yield and reliability of the solder joints.

To achieve integration of chip scale package (CSP) devices into main stream surface mount technology (SMT) assembly, various experiments have been required. In process development, experiences learned from flip chip attach and ball grid array (BGA) assembly were utilized. Key process parameters for CSP assembly were defined and some of those key factors were optimized. They will be presented in this paper. Some observations during prototype build have been documented for correlation with reliability results in the future. The requirements for further CSP assembly studies will also be addressed in this paper.

Taking as reference a sample of around a hundred biographical materials on entrepreneurs in Mexico and Colombia, the purpose of this chapter is dual. Both to show the relevance and varied modalities that the biographical approach has enjoyed in business history research since the 1990s, and to display the intrinsic potential this modality of scholarship entails for entrepreneurship endeavors. In particular, it discusses the prospects to incorporate this body of empirical works into the large Latin American audience attending undergraduate, graduate and executive education programs in business, economic history and related fields. The chapter is organized into three sections. The first two are devoted to illustrate relevant patterns in the entrepreneurial trajectory of individuals and entrepreneurial families studied in each of the two countries under consideration. The last section identifies some conceptual issues that may impact current debates on Latin American business development as exemplified in recent business and economic history journal venues and scholarly conferences.

In this chapter, we explore the intricate relationships between young disabled children, their families, institutional settings, and disability services in Canada, with an emphasis on the challenges stemming from unstable custodial dynamics and governmental interference. Drawing on data from a 9-year longitudinal Institutional Ethnography across three provinces and one territory, we analyze the experiences of 41 families who have interacted with the child welfare system, foster care, adoption processes, family courts, or other custodial procedures – many of them are Indigenous or live with low income. The historic and ongoing state control and institutionalization of disabled children in Canada are interrogated through the lens of settler-colonialism (Awj, 2017; Disability Rights International, 2021). This chapter scrutinizes constructs framed by colonial narratives, including disabled childhoods, notions of disability, the “best interest of the child,” the archetype of the “good parent,” and the designation of custodial “status.” We present Institutional Ethnography as a method of de-constructing these systems and identifying care principles in the changing context of family.

Organisational culture is increasingly being recognised as a critical determinant of the success or failure of organisational change efforts. A power utility company in Africa was undergoing planned change driven by its ambitious vision of becoming one of the top five performing utilities in the world. The purpose of this paper is to explore how the organisation’s culture was impacting on the change initiatives of one of the organisation’s operating units. The study also sought to investigate the robustness of the change model employed to inform the change process.

The study employed qualitative research methods for data collection, sampling and analysis. Ten semi-structured, in-depth interviews were conducted with managers, supervisory and non-supervisory staff in the operating unit. Data analysis was by means of thematic analysis.

Organisational culture was found to be impacting the operating unit’s change efforts. According to the participants, cultural analysis to determine organisational readiness for change was not adequately undertaken. The cultural factors of, among others, communication, feedback, involvement, and consultations negatively impacted the change efforts. The participants’ perceptions were that leadership failed to connect employees to the vision.

The paper provides insight into the importance of leadership’s understanding and consideration of organisational culture in change initiatives. Cultural analyses before embarking on change assists leaders in identifying and then strengthening or changing cultural tenets implicated by the change initiatives.

Recognizing construction workers' activities is critical for on-site performance and safety management. Thus, this study presents the potential of automatically recognizing construction workers' actions from activations of the erector spinae muscles.

A lab study was conducted wherein the participants (n = 10) performed rebar task, which involved placing and tying subtasks, with and without a wearable robot (exoskeleton). Trunk muscle activations for both conditions were trained with nine well-established supervised machine learning algorithms. Hold-out validation was carried out, and the performance of the models was evaluated using accuracy, precision, recall and F1 score.

Results indicate that classification models performed well for both experimental conditions with support vector machine, achieving the highest accuracy of 83.8% for the “exoskeleton” condition and 74.1% for the “without exoskeleton” condition.

The study paves the way for the development of smart wearable robotic technology which can augment itself based on the tasks performed by the construction workers.

This study contributes to the research on construction workers' action recognition using trunk muscle activity. Most of the human actions are largely performed with hands, and the advancements in ergonomic research have provided evidence for relationship between trunk muscles and the movements of hands. This relationship has not been explored for action recognition of construction workers, which is a gap in literature that this study attempts to address.

The purpose of this paper is to present an analysis of research on lean focusing on barriers in its implementation through a systematic literature survey.

A literature survey of peer-reviewed journal articles, survey reports, master theses, doctoral theses and paradigmatic books with managerial impact is used as the research methodology.

The findings derived from the evaluation of the publications analyzed have led to the identification of 24 lean barriers. The success of lean implementation will not be entirely based on application of appropriate tools and techniques alone but also on the top managements' involvement and leadership, workers' attitude, resources and the organizational culture.

This literature survey is primarily focused on lean implementation in the manufacturing sector.

This paper explores barriers for successful lean implementation and provides a concise description of the barriers that will be helpful for further studies in the domain of lean manufacturing.

Government of many countries around the world is encouraging and helping small- and medium-scale industries to understand and implement lean systems by preparing accessible database of lean consultants, providing financial assistance for training by professionals and establishing professional associations. However, many industries experienced failure in lean implementation. This research work provides a launching pad to develop a strategy to tackle barriers for successful lean implementation.

This paper puts forward the key barriers that should be tackled for successful lean implementation. It might represent new opportunities for rigorous and relevant research that would contribute to more translucent knowledge of lean being gained.