Search results

The encapsulation of electronic assemblies within thermoplastic polymers is an attractive technology for the protection of circuitry used in harsh environments, such as those experienced in automotive applications. However, the relatively low‐thermal conductivity of the encapsulating polymer will introduce a thermally insulating barrier, which will impact on the dissipation of heat from the components and may result in the build‐up of stresses in the structure. This paper therefore seeks to present the results from computational models used to investigate the thermal and thermo‐mechanical issues arising during the operation of such electronic modules. In particular, a two‐shot overmoulded structure comprising an inner layer of water soluble and an outer layer of conventional engineering thermoplastics was investigated, due to this type of structure's potential to enable the easy separation of the electronics from the polymer at the end‐of‐life for recycling.

Representative finite element models of the overmoulded electronic structures were constructed and the effects of the polymer overmould were analysed through thermal and thermo‐mechanical simulations. Investigations were also carried out to explore the effect of materials properties on the overmoulded structure.

Models have shown that some power de‐rating of components is required to prevent temperatures exceeding those in unencapsulated circuits and have quantified the benefits of adding thermally conductive fillers to the polymer. Simulations have also clearly demonstrated the benefits of foamed polymers in reducing thermal stresses in the assemblies, despite their poorer thermal conductivity compared with solid polymers.

The paper illustrates the thermal issues affecting the overmoulded electronics and gives some guidelines for improving their performance.

Some of you may be surprised to learn of some of the inventions originating from Australian endeavours — the black box flight recorder, atomic absorption spectrophotometer, over‐the‐horizon radar, combine harvester and the all important ‘esky’ cooler, to name but a few. However, in the 1980s the Australian electronics industry found itself in somewhat of a knowledge vacuum when it came to surface mount technology. The introduction of this technology and its advancement were happening overseas and it was taking some time for the information to get down under for Australian designers and manufacturers to apply this new enabling technology.

The purpose of this paper is to the investigate the rock music, and in particular the genre known as heavy metal, subculture in Iran and identify its relationship to social responsibility.

The research was conducted qualitatively through in-depth interview with more than 100 rock music fans who identify themselves as belonging to the particular subculture under investigation. It also investigates the history of such music within the country to explain that it is marginalized and forbidden in a way which is not generally understood in Western countries.

The findings of the paper show that the fans of the music identify themselves as a particular subculture within the society and share not just an interest in the music but also in social concerns, politics and religion.

This paper shows that subcultures are interrelated with social responsibility and that this is dependent upon the nature of the society in which the subculture resides. This is important in understanding the dynamics of change within a country.

This is one of the very few papers which looks at the link between subcultures and social responsibility and, therefore, is important in showing that social responsibility can develop independently of any organization while not being bounded by the nature of the society which spawns it.

The purpose of this paper is to study the thermal warpage of a plastic ball grid array (PBGA) mounted on a printed circuit board (PCB) during the reflow process.

A thermal-mechanical coupling method that used finite-element method software (ANSYS 13.1) was performed. Meanwhile, a shadow moiré apparatus (TherMoiré PS200) combined with a heating platform was used for the experimental measurement of the warpage of PBGA according to the JEDEC Standard.

The authors found that the temperature profiles taken from the simulated results and experimental measurement are consistent with each other, only with a little and acceptable difference in the maximum temperatures. Furthermore, the maximum warpage measurements during the reflow process are 0.157 mm and 0.149 mm for simulation and experimental measurements, respectively, with a small 5.37 per cent difference. The experimental measurement and simulated results are well correlated. Based on the validated finite element model, two factors, namely, the thickness and dimension of PCB, are explored about their effect on the thermal warpage of PBGA mounted on PCB during the reflow process.

The paper provides a thorough parametrical study of the thermal warpage of PBGA mounted on PCB during the reflow process.

The findings in this paper illustrate methods of warpage study by combination of thermal-mechanical finite element simulation and experimental measurement, which can provide good guidelines of the PCB design in the perspective of thermal warpage during the reflow process.