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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.

Understanding crack growth in solder joints is important for predicting the fatigue life of solder interconnects. In this paper, crack propagation in solder joints made of two solder alloys, 62Sn/36Pb/2Ag (by weight), a commonly used solder paste for SMT reflow applications, and 96.5Sn/3.5Ag (by weight), a lead‐free solder alloy, was examined during thermal cycling. Based on these observations, the rate of crack propagation was estimated. Microstructural changes in the solder during thermal cycling were also studied.

Detailed studies to characterise the coarsening behaviour of eutectic Sn‐Ag and near‐eutectic Sn‐Pb‐Ag solder joints were carried out on samples reflow soldered and solidified at various cooling rates. Light and scanning electron microscopy as well as EDS were used to study the microstructural evolution, while microhardness measurements were used to monitor the change in the mechanical properties. Samples consisting of copper substrates and solder paste were reflow soldered about 30 °C above their melting points and then solidified at cooling rates ranging from furnace cooling to rates associated with water quenching. Analysis of some of these samples showed that increasing the cooling rate increased the quantity (volume fraction) of primary Sn‐dendrites, decreased the (EQ) intermetallic phase in the bulk solder, and resulted in finer microstructures with higher hardness. The microstructural evaluation involved characterisation of bulk intermetallica and dendrite/eutectic ratios. Subsequent isothermal annealing of these reflow soldered joints at 125 °C for times between 0.25 h and 8 days resulted in an initially fairly rapid decrease in hardness to a given level for each alloy and each cooling rate.

More and more diversity is present in our classrooms. As teachers, we must be able to respond to the different levels of learning presented by our students. Therefore, it is necessary to use the new emerging technologies as elements of response. Thus, the purpose of this paper is to develop a systematic and thematic review of the application of augmented reality (AR) in the learning of autistic students in the educational setting during the period 1996–2020 using the Web of Science and Scopus databases.

For this purpose, one of the bibliometric techniques called systematic and thematic review has been used. This technique is supported by the preferred reporting items for systematic reviews methodology, and it uses a quantitative and qualitative approach. The thematic analysis will be carried out on 28 documents based on a series of indicators, including sample size, hardware devices, way of storing the information and findings obtained in the research.

The results of the work indicate that the average size of the sample is three participants, and that the most worked area has been social skills using tablets. In addition, bookmarks are often used as an element of information storage in AR.

The main contribution of this work focuses on the establishment of a series of thematic variables that will serve for the later development of an action protocol for the creation of AR activities for autistic students.

Lead‐free soldering is becoming a common practice in the electronics industry because of the growing general opposition to lead‐containing solders. The reliability of lead‐free solders has been studied a lot recently, but knowledge of it is still incomplete and many issues related to them are under heavy debate. This paper presents results from a study of the formation of voids with regard to the number of reflow cycles in three different kinds of solder joints: first the ones prepared with lead‐free solder paste and lead‐free plastic ball grid array (PBGA) components, next the ones prepared with lead‐free solder paste and tin‐lead‐silver PBGA components, and last the ones prepared with tin‐lead solder paste and tin‐lead‐silver PBGA components.

The goal of this work is to evaluate the feasibility of soldering tin‐silver‐copper balled BGAs using tin‐lead‐based solder and to investigate the influence of different production parameters on the microstructure of the solder joint.

The soldering of the BGAs was done with various temperature profiles and two conveyor speeds under a nitrogen atmosphere in a full convection oven. One specimen from each temperature/time combination was cross‐sectioned. The cross sections were analysed with optical microscopy, scanning electron microscopy with energy dispersive X‐ray spectroscopy (SEM/EDS) at 30 kV and focused ion beam microscopy (FIB).

The cross sections show a metallurgical bond between the solder and the tin‐silver‐copper balls of the BGA, even at a peak reflow temperature of 210°C. However, the balls alloy only partially with the solder, as the liquidus of tin‐silver‐copper balls is 217°C. As soon as the peak temperature exceeds the liquidus of the ball, the solder is totally dissolved in the material of the ball. A reflow profile with a peak temperature of about 230°C on the BGA gives a homogenous reaction of the solder with the ball with a minimum formation of voids.

The dependence of varying reflow parameters on reliability requires detailed study. Especially the effect of a partially melted ball on the degradation of the solder joint needs to be investigated.

From the findings, it can be said that soldering lead‐free balls with tin‐lead solder is possible. This is useful during the transitional period that the industry is in at the moment. More and more component manufacturers are changing their components to lead‐free, often without notice to the customer. If a production line is still running a tin‐lead process it is essential to know how to process these components with tin‐lead solder.

To study the behaviour of voids in PBGA solder joints and their influence on the lifetime of lead‐free solder joints.

The behaviour of voids was studied using micro via and land pad PWBs, PBGA components, and by measuring voids in the solder joints. The lifetimes of solder joints were tested using accelerated temperature tests.

Number of factors affecting the solder joint lifetimes were found. The voids were discovered to have a significantly large influence on the solder joints.

The findings can be used to achieve better soldering results, methods, and designs.

In this paper, the effect and the behaviour of voids were studied profoundly. The findings can be valuable to researchers and process personnel.

The effects of Pb contamination on the microstructure and shear strength of lead‐free solder joints with non‐lead containing finishes on both the PCB and terminals of 1,206 chip capacitors at different temperatures were investigated. Two kinds of lead‐free solders (Sn96.5Ag3.5 and Sn95Sb5) were selected, and different amounts of eutectic Sn‐Pb were added to these lead‐free solders according to the potential Pb contamination in a 1,206 chip capacitor solder joint. It was found that there was no difference in shear strength of solder joint at room temperature for those with or without Pb contamination, but the shear strength at 1258C for the solder joint without Pb contamination was about 15 percent higher than for those with Pb contamination.

The existing literature on linking growers directly with the market mostly overlooks the case of smallholders. They grow commercial–perishable crops and have to rely on the efficacy of the marketing system. The present paper intends to fill this void.

The paper studies the performance of two local markets among 216 pineapple producers and 50 traders using the structure–conduct–performance framework. Following which the authors attempt to unravel the determinants of growers' direct participation in the market and the impact of such involvement on the farm income using the Heckman two-stage treatment effect model.

The study analysis shows that the likelihood of growers’ direct participation in markets, found oligopolistic, increases with education, price information and family labor unit, while decreases with the growers' age, distance from market and the footfall of intermediaries at the farm gate. The second stage of the model has established a positive impact of participation on farm income.

The small sample size could restrict generalization. The authors used only operating efficiency as an indicator of the performance of the marketing system due to the unavailability of district-level time series data on pineapple pricing.

This study shows that local food markets are oligopolistic. Growers fetch very less share in consumers' price and become vulnerable to food insecurity. The study highlights the determinants of growers' direct participation in the local market and the impact of such involvement on farm income.

In an attempt to improve service life of lead‐free Sn‐based electronic solder joints, compatible reinforcements were introduced by in‐situ and mechanical mixing methods. The reinforcements affect the steady‐state creep rate and the strain for the onset of tertiary creep of the solder joints. However, neither of these parameters, when considered alone, can be used for evaluating the reliability of solder joints. The Larson‐Miller parameter, and a new parameter proposed in the paper, can incorporate test parameters to arrive at a reliability prediction methodology. The role of these reinforcements in homogenising creep strain within the joint is analysed. The observed creep behaviour of these composite solders is discussed on the basis of interfacial bonding strength between the reinforcement and the solder matrix.