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This paper's purpose is to review the design of a flip chip thermal test vehicle.

Design requirements for different applications such as thermal characterization, assembly process optimization, and product burn‐in simulation are outlined and the design processes of different thermal test chip structures including the temperature sensor and passive heaters are described in detail. The design of fireball heater, a novel test chip structure used for evaluating the effectiveness of heat spreading of advanced thermal solutions, is also explained.

Describes the design considerations and processes of the package substrate and printed‐circuit board with special emphasis on the physical routing of the thermal test chip structures. These design processes are supported with thermal data from various finite‐element analyses carried out to evaluate the capability and limitations of thermal test vehicle design.

The validation and calibration procedures of a thermal test vehicle are presented in this paper.

This chapter proposes an approach toward the estimation of cross-sectional sample selection models, where the shocks on the units of observation feature some interdependence through spatial or network autocorrelation. In particular, this chapter improves on prior Bayesian work on this subject by proposing a modified approach toward sampling the multivariate-truncated, cross-sectionally dependent latent variable of the selection equation. This chapter outlines the model and implementation approach and provides simulation results documenting the better performance of the proposed approach relative to existing ones.

The purpose of this paper is to examine the use of phragmites australis ash (PAA) in cementitious systems to achieve sustainable construction.

In this paper, the properties of mortar containing PAA as partial cement replacement are determined. The PAA is produced through slow burning in a closed system to minimize the CO₂ emission. A total of four mortar mixes are prepared with PAA replacement levels ranging from 0% to 30% by weight. The water to binder and the proportions of binder to sand are 0.55 and 1:3 by weight, respectively. The properties tested are density, compressive strength, flexural strength, ultrasonic pulse velocity, water absorption by total immersion and capillary rise. Testing is conducted at 1, 7, 28 and 90 days.

While there is a decrease in strength as the amount of PAA increases, there is strong indication of pozzolanic reaction in the presence of PAA. This is in agreement with the results reported by Salvo et al. (2015), where they found noticeable pozzolanic activities in the presence of straw ash, which is rich in SiO₂ and relatively high K₂O content. At 90 days of curing, there is a decrease of 5% in compressive strength at 10% PAA replacement. However, at 20% and 30% replacement, the reduction in compressive strength is 23% and 32%, respectively. The trend in flexural strength and ultrasonic pulse velocity is similar to that in compressive strength. The water absorption by total immersion and capillary rise tends to increase with increasing amounts of PAA in the mix. There seems to be a linear relationship between water absorption and compressive strength at each curing age.

The Phragmites australis plant used in this investigation is obtained from one location and this present a limitation as the type of soil may change the properties. Also one method of slow burning is used. Different burning methods may alter the composition of the PAA.

This outcome of this research will contribute towards sustainable development as it will make use of the waste generated, reduce the amount of energy-intensive cement used in construction and help generate local employment in the area where the Phragmites australis plant grows.

To the best knowledge of the authors, the ash from the Phragmites australis plant has not been used in cementitious system and this research can be considered original as it examines the properties of mortar containing PAA. Also, the process of burning in a closed system using this material.

The introduction of high density surface mount technology may lead to a number of metallurgical problems. This paper considers two aspects which are currently being actively discussed. Firstly, incompatibility in expansion properties of the materials used and severe thermal cycling may induce creep and fatigue stresses on soldered joints, and the merits of different alloys are considered. Secondly, the necessary thermal treatments such as burn‐in and elevated service temperature can lead to intermetallic compound layer growth between the solder and the metallised layer on components which may be considered a potential source of joint strength reduction. Mention is also made of the different visual appearance of joints to chip components compared with conventional soldered joints.

RELIABILITY is one of the most important criteria in modern electronic systems, with pressure quite rightly towards continual improvement. Much mystery surrounds such innocent letters as MTTF (mean time to failure) and many people fall into the trap of assuming that this means the average life of the component. In fact when a time equal to the MTTF is reached only 37% of the components are still surviving.

Longwall mining is a special mining method with high productivity and smooth operation and the drum shearer is known as the most important component in longwall mines due to its direct role in the coal cutting and production process. Therefore, its reliability is important in keeping the mine production at a desired level. Hence, reliability analysis is essential in identifying and removing existing problems of this machine in order to achieve a better production condition. This paper seeks to learn about the reliability of the shearer machine in order to locate critical subsystems. The improvement of the reliability of the critical subsystems, to enhance the optimum operation of the shearer machine, is the main objective of this research.

A basic methodology was used in this paper for the reliability modeling of the shearer machine. First, failure and performance data from a two‐year period at the Tabas Coal Mine‐Iran was classified and sorted. The tests for validating the assumption of independent and identical distribution (iid) of TBF data are done and the best modeling method for each subsystem was selected among the renewal process, homogeneous Poisson process and non‐homogeneous Poisson process. Finally, the reliability of subsystems and the machine were assessed.

The study revealed that six important subsystems of the shearer machine are; water system, haulage, electrical system, hydraulic system, cutting arms, and cable system. Pareto analysis shows that the 30 percent of failures and stoppages of the shearer were related to the water system and this system is the most critical subsystem of the machine. The failure rate analysis shows that the failure rates of the hydraulic, haulage and electrical systems were decreasing, meanwhile, the failure rates of the water system, cutting arms and cable system were increasing. The reliability of drum shearer reaches the zero value after 100 hours.

This paper, for the first time, defines a practical set of subsystems for the coal shearer based on field data and machine design.

Electronic materials, particularly tin‐lead coated component leads, may degrade and acquire a poor solderability as a result of long‐term storage or prolonged periods at elevated temperatures (during burn‐in). This paper presents the results of studies on the surface chemistry and microstructure of such coatings together with a technique for stripping degraded coatings and replacing them with pristine finishes having excellent solderability.

Thick film screen printing technology is able to reach a pitch of 250 μm. In an attempt to achieve lower values, two approaches have been developed so far. Both are based on the combination of screen printing as a deposition technique and photolithography for the patterning. The first approach uses photoimageable conductor and dielectric pastes; the second is based on photoimageable dielectric and etching of the fired conductor. In order to obtain a full characterisation of both processes, a test module was designed and manufactured by using the first process and identical test modules were provided by the supplier using the second technology. The design of the test module is based on a two‐layer interconnection pattern including structures for testing cross‐overs, via interconnections with various resolutions (down to 50 μm via size), in order to investigate the limits of these technologies. This paper gives a comparison of these two approaches based on the results of electrical and mechanical measurements performed on both sets of the test modules. Electrical parameters and resolution data are discussed for both processes. The chip and wire assembly method is evaluated to prequalify the technology as an advanced MCM‐C technology for telecoms applications. Finally, the results of reliability tests (humidity ageing and burn‐in) are presented.

The Supreme Court's recent cross burning case – Virginia v. Black (2003) – saw dueling historical narratives. Justice O’Connor, writing for the majority, painted a history in which the Klan often burned crosses to intimidate, but also did so for other, “expressive” reasons. Justice Thomas, in dissent, related a history in which the burning cross never speaks. Interestingly, O’Connor and Thomas used many of the same historical sources. How did they reach such different results? While both O’Connor and Thomas interpreted (and stretched) the historical sources in different directions, their dispute ultimately turned on their diverging doctrinal views.