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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 purpose of this paper is to describe the board level reliability test results of four IC packages with lead‐free balls/platings, soldered with lead‐free solder paste, during thermal cycling. The board level reliability test results of tin‐lead balled/plated packages soldered with lead‐free solder paste have also been included for comparison.

Four different packages, i.e. ball grid array (BGA), chip scale package (CSP), quad flat package (QFP) and thin small outline package (TSOP), were assembled on a test printed circuit board (PCB) as the test vehicle. Lead‐free and tin‐lead BGA/CSP packages were equipped with Sn‐3.0Ag‐0.5Cu and Sn‐37Pb solder balls, respectively. The lead‐frames of lead‐free QFP/TSOP leaded‐packages were plated with Sn‐58Bi and those of tin‐lead QFP/TSOP leaded‐packages, Sn‐37Pb. The lead‐free solder paste used in this study was Sn‐3.0Ag‐0.5Cu. Two kinds of surface finishes, immersion gold over electroless nickel (Au/Ni) and organic solderability preservative, were used on the PCBs. The test PCBs were thermal cycled 5,000 times within the temperature range of −40 to 125°C and electrically monitored during the thermal cycling.

It was found that the tin‐lead balled/plated BGAs, CSPs, QFPs and TSOPs soldered with lead‐free solder paste showed serious board level reliability risks as their abilities to withstand thermal cycling stresses are much weaker than those of entirely lead‐free assemblies. Neither package nor surface finish was found to have any effects on the board level reliability of test vehicles with lead‐free balled/plated BGAs, CSPs, QFPs and TSOPs. Metallographic examinations were conducted to investigate the effect of thermal cycling on the failure modes of solder joints.

The paper is of value by contributing to research in the use of lead‐free solder paste with lead‐containing packages in the industry. Currently, there is a deficiency of knowledge in this area.

This article aims to discuss the construction of a system for temperature cycling, where Peltier elements are used as heating or cooling elements. This article describes the results and experiences based on several years of practice in the area of thermo-mechanical reliability of soldered joints on printed boards with SMD components.

The authors discuss the characteristics of the design, the threshold temperatures, dynamic properties of the system and, most importantly, the reliability and the useful life of the Peltier elements. The advantages and disadvantages of the system are mentioned as well as examples of use.

The utilisation of Peltier elements for temperature cycling is possible, but it is important to keep in mind that the reliability of the elements is similar to the reliability of the system, and therefore, it is essential to replace the defective Peltier elements during the cycling.

The construction of system is very simply. It is necessary to ensure the Peltier elements with low dispersion parameters.

The system is very well suited for cycling of printed boards, especially one sided, multi-chip systems, COB systems, flip-chip embedded construction, etc. The system can be used in situations where it is possible to ensure an effective heat transfer and where extremely low temperatures are not required.

The effects of thermal fatigue and printed circuit board (PCB) surface finish on the pull strength, failure modes and reliability of chip scale package (CSP) solder joints were investigated.

Mechanical pull test, metallographic examination and electrical measurement were used. Tin lead (Sn‐Pb) and lead free (Sn‐Ag‐Cu) alloys were used with Au/Ni and organic solderability preservative (OSP) surface finishes.

The experimental results showed that the pull strength of the Sn‐Ag‐Cu/(Au/Ni) solder joint did not change noticeably with an increasing number of thermal cycles. However, the pull strength of the Sn‐Pb/(Au/Ni) solder joints drastically degraded and that of the Sn‐Ag‐Cu/OSP and Sn‐Pb/OSP solder joints slightly decreased during thermal cycling. For both Sn‐Ag‐Cu and Sn‐Pb alloys, the solder joint fracture of as‐soldered samples was the main failure mode when an Au/Ni surface finish was used. For the Sn‐Ag‐Cu/(Au/Ni) and Sn‐Ag‐Cu/OSP solder joints, the proportion of component trace tearing considerably decreased, whereas that of PCB trace tearing considerably increased, during thermal cycling. The Weibull lifetimes of the solder joints were increasingly longer in the order of Sn‐Pb/(Au/Ni), Sn‐Pb/OSP, Sn‐Ag‐Cu/OSP, and Sn‐Ag‐Cu/(Au/Ni).

This was not an exhaustive study and all of the findings are for lead free and tin lead CSP solder joints, which perhaps limits the usefulness of the results elsewhere.

A very useful source of information and impartial advice for engineers planning to conduct a switch from tin lead to lead free technology in their production lines.

This paper fulfils an identified information/resources need and offers practical help to an engineer starting out on an engineering development.

This paper aims to study a high-temperature (up to 200 °C) data acquisition and processing circuit for logging.

With the decrease in thermal resistance by system-in package technology and exquisite power consumption distribution design, the circuit worked well at high temperatures environment from both theoretical analysis and real experiments evaluation.

In thermal simulation, considering on board chips’ power consumption as additional heat source, the highest temperature point reached by all the chips in the circuit is only 211 °C at work temperature of 200 °C. In addition, the proposed circuit was validated by long time high-temperature experiments. The circuit showed good dynamic performance during a 4-h test in a 200-°C oven, and maintained a signal-to-noise ratio of 92.54 dB, a signal-to-noise and distortion ratio of 91.81 dB, a total harmonic distortion of −99.89 dB and a spurious free dynamic range of 100.28 dB.

The proposed circuit and methodology showed great potential for application in deep-well logging systems and other high-temperature situations.

Recently nanoparticles reinforced lead free solders are vastly developed in electronics packaging industry. Studies and investigations have been conducted to learn and investigate the types, properties, method, availability and importance of nanoparticles in this field.

Mechanical properties, melting temperature and microstructural conditions are taken into major considerations in any of the preparation on nanoparticles and being reviewed in this paper. Segregation of the types of nanoparticles being added together with their properties is summarized in this paper. High temperature reliability is crucial in providing a good viable solder and hence addition of nanoparticles have been seen to give a positive outcome in this particular property.

This paper reviews on the beneficial of the various nanoparticles addition in the solder. Briefed explanations and the factors are revealed in this review.

This paper reviews on the beneficial of the various nanoparticles addition in the solder.

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.

The purpose of this paper is to assess the effect of different temperature cycling profiles on the reliability of lead‐free 388 plastic ball grid array (PBGA) packages and to deeply understand crack initiation and propagation.

Temperature cycling of Sn‐3.8Ag‐0.7Cu PBGA packages was carried out at two temperature profiles, the first ranging between −55°C and 100°C (TC1) and the second between 0°C and 100°C (TC2). Crack initiation and propagation was analyzed periodically and totally 7,000 cycles were run for TC1 and 14,500 for TC2. Finite element modeling (FEM), for the analysis of strain and stress, was used to corroborate the experimental results.

The paper finds that TC1 had a characteristic life of 5,415 cycles and TC2 of 14,094 cycles, resulting in an acceleration factor of 2.6 between both profiles. Cracks were first visible for TC1, after 2,500 cycles, and only after 4,000 cycles for TC2. The crack propagation rate was faster for TC1 compared to TC2, and faster at the package side compared to the substrate side. The difference in crack propagation rate between the package side and substrate side was much larger for TC1 compared to TC2. Cracks developed first at the package side, and were also larger compared to the substrate side. The Cu tracks on the substrate side affected the crack propagation sites and behaved as SMD. All cracks propagated through the solder and crack propagation was mainly intergranular. Crack propagation was very random and did not follow the distance to neutral point (DNP) theory. FEM corroborated the experimental results, showing both the same critical location of highest creep strain and the independence of DNP.

Such extensive work on the reliability assessment of Pb‐free 388 PBGA packages has never been performed. This work also corroborates the results from other studies showing the difference in behavior between Pb‐free and Pb‐containing alloys.

The paper aims to deal with the benefits and challenges of 3D integration of electronics and mechanics as well as the special requirements in designing a system.

Three‐dimensional integration technology has been enabled by innovations in thermoplastic printed circuit board (PCB) materials and novel system integration. Furthermore, the integration of electronics and mechanics helps manage product creation, as design phases must be integrated and teamwork well organized. A multidisciplinary approach is another must in marketing technology, because any decision to incorporate an integrative technology in a product must be based on an understanding of the many forms of expertise involved in creating a product.

With a unique copper pattern for each 3D shape, inconvenient distortions can be controlled, as dedicated copper patterns enable designers to make efficient use of formable multilayer structures and advance an extra step in freedom of design. Findings are based on a working demonstrator.

Even if 3D multilayer design now lacks dedicated tools, software is likely to evolve to include all necessary functions.

Forming a multilayer PCB enables designers to free their imagination and to take advantage of numerous possibilities, including even futuristic shapes.

Three‐dimensional integration offers great potential for product design, although by definition and in terms of production technology 3D integration is an incremental change.

The purpose of this work is to study the effect of the reflow peak temperature and time above liquidus on both SnPb and SnAgCu solder joint shear strength.

Nine reflow profiles for Sn3.0Ag0.5Cu and nine reflow profiles for Sn37Pb have been developed with three levels of peak temperature (230°C, 240°C, and 250°C for Sn3.0Ag0.5Cu; and 195°C, 205°C, and 215°C for Sn37Pb) and three levels of time above solder liquidus temperature (30, 60, and 90 s). The shear force data of four different sizes of chip resistors (1206, 0805, 0603, and 0402) are compared across the different profiles. The shear forces for the resistors were measured after assembly. The fracture interfaces were inspected using scanning electron microscopy with energy dispersive spectroscopy in order to determine the failure mode and failure surface morphology.

The results show that the effects of the peak temperature and the time above solder liquidus temperature are not consistent between different component sizes and between Sn37Pb and Sn3.0Ag0.5Cu solder. The shear force of SnPb solder joints is higher than that of Sn3.0Ag0.5Cu solder joints because the wetting of SnPb is better than that of SnAgCu.

This study finds that fracture occurred partially in the termination metallization and partially in the bulk solder joint. To eliminate the effect of the termination metallization, future research is recommended to conduct the same study on solder joints without component attachment.

The shear strength of both SnPb and SnAgCu solder joints is equal to or higher than that of the termination metallization for the components tested.

Fracture was observed to occur partially in the termination metallization (Ag layer) and partially in the bulk solder joint. Therefore, it is essential to inspect the fracture interfaces when comparing solder joint shear strength.