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This paper aims to describe and document the application of commonly utilized solder joint failure analysis techniques to lead‐free solder joints.

Traditional failure analysis techniques, including visual inspection, X‐ray radiography, mechanical strength testing, dye and pry, metallography, microscopy and photomicrography, are reviewed. These techniques are demonstrated as applied to lead‐free and tin lead solder joints. Common failure modes observed in lead‐free and tin lead solder joints are described and compared.

It is shown that the traditional failure analysis techniques previously utilized for tin lead solder joints are widely applicable to the analysis of lead‐free solder joints. The changes required to effectively apply these techniques to the analysis of lead‐free solder joints are described.

This paper will be instrumental to the process, quality, reliability and failure analysis engineering disciplines in furthering understanding of the application of failure analysis techniques of both tin lead and lead‐free solder joints.

0201 assembly plays a very important role in the continuing miniaturization of electronics products. After a systematic study using Sn‐Pb solder paste on pad design, machine evaluation, component qualification, and process optimisation, this study focused on the PCB assembly process for 0201 packages using Sn‐Ag‐Cu solder paste. The post‐reflow solder defects for a range of different spacings were examined for the different solder pastes.

Failure analyses of the lead‐free and SnPb solder joints of high‐density packages such as the plastic ball grid array and the ceramic column grid array soldered on SnCu hot‐air solder levelling electroless nickel‐immersion gold or NiAu, and organic solderability preservative Entek printed circuit boards are presented. Emphasis is placed on determining the failure locations, failure modes, and intermetallic compound composition for these high‐density packages' solder joints after they have been through 7,500 cycles of temperature cycling. The present results will be compared with those obtained from temperature cycling and finite element analysis.

The mechanical properties of Sn/Ag/Cu solder joints in combination with different component lead coating materials (Ni/Pd/Au, Sn/15 per cent Pb, Sn/2 per cent Bi, and Sn) are studied in this work using a lead pull test and free fall drop test. The results of this study show that the Sn/2 per cent Bi coated components provide the best performance under the drop impact loading followed by the Sn/15 per cent Pb, Sn and Ni/Pd/Au coated components. Failure modes and the structure of the coating surfaces were examined from cross‐sectioned samples using a scanning electron microscope. Furthermore, the wetting of the leads by the solder and thickness of the IMC layers were studied.

The lead‐free solder joint reliability of several printed circuit board mounted high‐density packages, when subjected to temperature cycling was investigated by finite element modelling. The packages were a 256‐pin plastic ball grid array (PBGA), a 388‐pin PBGA, and a 1657‐pin ceramic column grid array. Emphasis was placed on the determination of the creep responses (e.g. stress, strain, and strain energy density) of the lead‐free solder joints of these packages.

The mechanical integrity of solder joint interconnects in PWB assemblies with micro ‐ BGA, chip scale, and LGA packages are being questioned as the size and pitch decrease. Three‐point cyclic bend testing provides a useful tool for characterizing the expected mechanical cycling fatigue reliability of PWB assemblies. Cyclic bend testing is useful for characterizing bending issues in electronic assemblies such as repetitive keypad actuation in cell phone products. This paper presents the results of three‐point bend testing of PWB assemblies with fine pitch packages. The methodology of materials analyses of the metallurgy of solder interconnects following mechanical bending and thermal cycle testing is described.

The purpose of this study was to investigate the changes in solder joint stress when subjected to mechanical bending. The analytical theory pertaining to the stresses in the solder joint between the components (including the molding compound, the chip and the substrate) was described, and the printed circuit board (PCB) with a discontinuity function when the PCB assembly is subjected to mechanical bending was developed. Thus, the findings reported here may lead to a better understanding of the solder joint failure based on the Physics of Failure model.

This paper discusses the analytical model for calculating the stress in solder joints, as well as presents a simulation model that can be used for calculating the strain energy density of solder joint. First, the multilayer plate theory is used in discussing the composite material for the component, including the molding compound, the silicon chip and the substrate, or the PCB, including the copper layers, the fiber and the epoxy. Finally, the complete structure of the analytical model developed as a part of this current work is presented.

For the analytical model of multilayer structures in which the interconnection layer is discrete, mechanical bending has been modeled with respect to varying silicon chip length. The analytical model that describes the stress of the outermost solder joint experiences is chosen, as this is the typical solder joint failure. The analytical model can be applied to discrete solder joints, which are evaluated by calculating the matrix form. Owing to its use of the matrix equation, the analytical model can be highly combinatorial and thus more capable of calculating the solution.

The analytical solution based on a simple concept was presented and validated using the finite element model for the stress experienced by solder joints subjected to mechanical bending. To verify that the simulation represents a real PCB case, the authors use the finite element method (FEM) to compare their case with the multilayer plate theory. Owing to the good agreement between the theory and simulation results, the authors conclude that the multilayer plate theory can be correctly applied in multilayer PCB and be used in an analytical model for the PCB assembly subjected to mechanical bending.

Owing to the good agreement between the theory and simulation results, the authors conclude that the multilayer plate theory can be correctly applied in multilayer PCB and be used in an analytical model for the PCB assembly subjected to mechanical bending.

The analytical model is validated with the FEM model and provides the way to physically examine the solder joint failure mechanism. In this paper, the analytical model is developed as a means to assess the solder joint stress subjected to mechanical bending.

The analytical model treats the solder joint as discrete and has been successfully validated against the finite element model. The complete structure model (the second analytical model) is presented to discuss the effects of varying silicon chip length on the normal stress in solder joints. When the silicon chip length exceeds to 80 per cent of the total package length, the stress of the outermost solder joint increases rapidly. The design analysis findings have suggested that the failure of the outermost solder joint subjected to mechanical bending on the PCB assembly can be reduced by analyzing the analytical model.

This chapter reviews the existing empirical evidence on how social insurance affects health. Social insurance encompasses programs primarily designed to insure against health risks, such as health insurance, sick leave insurance, accident insurance, long-term care insurance, and disability insurance as well as other programs, such as unemployment insurance, pension insurance, and country-specific social insurance programs. These insurance systems exist in almost all developed countries around the world. This chapter discusses the state-of-the art evidence on each of these social insurance systems, briefly reviews the empirical methods for identifying causal effects, and examines possible limitations to these methods. The findings reveal robust and rich evidence on first-stage behavioral responses (“moral hazard”) to changes in insurance coverage. Surprisingly, evidence on how changes in coverage impact beneficiaries’ health is scant and inconclusive. This lack of identified causal health effects is directly related to limitations on how human health is typically measured, limitations on the empirical approaches, and a paucity of administrative panel data spanning long-time horizons. Future research must be conducted to fill these gaps. Of particular importance is evidence on how these social insurance systems interact and affect human health over the life cycle.

This book aimed to conceptualise a construction workforce management model suitable for effectively managing workers in construction organisations. To this end, this chapter presents the conceptualised model, which consists of seven workforce management practices with their respective measurement variables. Drawing from existing theories, models, and practices, the chapter concludes that a construction organisation that will attain its strategic objectives in the current fourth industrial revolution era must be willing to promote effective recruitment and selection, compensation and benefits, performance management and appraisal, employee involvement and empowerment, training and development, as well as improving workers emotional intelligence and handling external environment pressure. These practices can promote proactiveness, participation, and improved skills and can lead to effective commitment, better quality, and flexibility within the organisation.

The purpose of this paper is to answer the call for CSR communication research to develop and substantiate outcomes that may better explain CSR communication strategies and practices. The paper takes the research a step further, exploring the role of legitimacy in CSR communication research.

A literature collection methodology, combined with directed content analysis, was used to identify central themes in the literature.

The following categories of studies were identified: perception, impact and promotion studies; image and reputation studies; performance studies; and conceptual/rhetorical studies. Addressed from a legitimacy perspective, the study found that the most important types of legitimizing communicative practices articulated in the four types of studies were related to: seeking knowledge about stakeholders through perception, impact and promotion activities; monitoring and controlling the environment through image and reputation activities; creating stakeholder value through collaboration and engagement; and persuading and convincing stakeholders through rhetorics, CSR models and concepts. The study also found that practices and activities related to perceiving stakeholders’ expectations, needs and requirements are assumed to be most effective for corporations aiming at building or maintaining legitimacy.

The key contribution of the paper lies in exploring how corporate legitimacy is anticipated and extrapolated in the CSR communication literature, including which pinpointed CSR communication strategies and practices are assumed to be more effective than others in bridging stakeholders’ perceptions of corporations’ social and environmental actions. Until date, no reviews exist of the role of legitimacy in CSR communication research.