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Eliminating lead in electronics is an environmentally considerate approach that is made prior to manufacture. Recently enacted legislation encourages increased recycling of electrical and electronic products. However, recycling is typically an end‐of‐use action occurring just before final disposal. From an environmentally‐considerate perspective, lead elimination or replacement is a better approach. Short of having a definitive study to follow, industry, regulators, and consumers are proceeding with the change. Various lead‐free alloys have been tested and used for electronic components and assemblies. There are many replacements for eutectic tin‐lead solder, and alloys containing tin, silver, copper, and bismuth have been used successfully. Assessing how the electronics industry is addressing the change to lead‐free materials and processes requires answers to various questions. These questions regard the effects of changes to electronic products and their processes. What drives lead‐free migration, how processes can develop, and when products will be available are issues which define the assessment.

As the electronics industry moves towards the 21st century, environmentally conscious manufacturing is becoming a very important issue for the industry. In recent years, advanced manufacturing technologies have been developed for automotive electronics packing that not only are environmentally friendly, but also reduce manufacturing complexity and cost, improve product quality, and meet the stringent reliability requirements for the automotive environment. In this paper, aspects of no‐clean soldering and lead‐free solderr development are reviewed, and some of the most critical factors for implementing no‐clean soldering and for developing lead‐free solders for automotive electronics are outlined.

This paper presents the analysis of information collected from numerous patent searches on lead‐free alloys. The significance of claim structure and content is discussed in view of the growing number of lead‐free patents. Patent analysis software was developed to effectively compare over 350 lead‐free alloy patents. A case study was conducted to assess Sn‐Ag‐Cu and special purpose lead‐free candidate alloy intellectual property. The results show that there are a number of patents and patent applications that may affect the use of “popular” Sn‐Ag‐Cu formulations.

The aim of this paper is to present a review of the tin whisker growth phenomena. The study focuses mainly on whisker growth in a corrosive climate when the main inducing factor of the whisker growth is oxidation. The tin whisker phenomenon is still a big challenge in lead-free reflow soldering technology. Modern lead-free alloys and surface finishes with high tin content are considered to be possible sources of whisker development, also the evolution of electronic devices towards further complexity and miniaturization points to an escalation of the reliability risks.

The present work was based on a worldwide literature review of the substantial previous works in the past decade, as well as on the results and experience of the authors in this field.

The effect of corrosion on tin whisker growth has been under-represented in reports of mainstream research; however, in the past five years, significant results were obtained in the field which raised the corrosion phenomena from being a side effect category into one of the main inducing factors. This paper summarizes the most important findings of this field.

This literature review provides engineers and researchers with a better understanding of the role of corrosion in tin whisker growth and the current challenges in tin whisker mitigation.

The unique challenges and future research directions about the tin whisker phenomenon were shown to highlight rarely discussed risks and problems in lead-free soldering reliability.

The purpose of the paper is to experimentally evaluate the impact of voids on thermal conductivity of a macro solder joint formed between a copper cylinder and a copper plate by using reflow soldering.

A model of a surface mount device (SMD) was developed in the shape of a cylinder. A copper plate works as a printed circuit board (PCB). The resistor was connected to a power supply and the plate was cooled by a heat sink and a powerful fan. A macro solder joint was formed between a copper cylinder and a copper plate using reflow soldering and a lead-free solder paste SAC305. The solder paste was printed on a plate through stencils of various apertures. It was expected that various apertures of stencils will moderate the various void contents in solder joints. K-type thermocouples mounted inside cylinders and at the bottom of a plate underneath the cylinders measured the temperature gradient on both sides of the solder joint. After finishing the temperature measurements, the cylinders were thinned by milling to thickness of about 2 mm and then X-ray images were taken to evaluate the void contents. Finally the tablets were cross-sectioned to enable scanning electron microscopy (SEM) observations.

There was no clear dependence between thermal conductivity of solder joints and void contents. The authors state that other factors such as intermetallic layers, microcracks, crystal grain morfologyof the interface between the solder and the substrate influence on thermal conductivity. To support this observation, further investigations using metallographic methods are required.

Results allow us to assume that the use of SAC305 alloy for soldering of components with high thermal loads is risky. The common method for thermal balance calculation is based on the sum of serial thermal resistances of mechanical compounds. For these calculations, solder joints are represented with bulk SAC305 thermal conductivity parameters. Thermal conductivity of solder joints for high density of thermal energy is much lower than expected. Solder joints’ structure is not fully comparable with bulk SAC305 alloy. In experiments, the average value of the solder joint conductivity was found to be 8.1 W/m·K, which is about 14 per cent of the nominal value of SAC305 thermal conductivity.