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This paper reviews technologies used for the prevention of electromagnetic interference in current portable electronic products. It studies the need for future advanced products and some of the technologies likely to be available. The focus is on housing technologies and the products available for giving greatest electromagnetic compatibility with the latest European and other emission and susceptibility standards. It is concluded that new or improved approaches which are better able to ensure long‐term reliability will be essential for the 100 MHz clock speed equipment likely to be in production within the coming five years.

The purpose of this paper is to optimize the performance of direct methanol fuel cells for portable applications by combining a non‐linear, fully coupled circuit model and a stochastic optimization procedure.

A novel non‐linear equivalent circuit that accounts for electrochemical reactions and charge generation inside catalyst layers, electronic and protonic conduction, methanol crossover through the membrane, mass transport of reactants inside diffusion layers is presented. The discharge dynamic of the fuel cell, depending on the initial methanol concentration and on the load profile, is modelled by using the mass conservation equation. The equivalent circuit is interfaced to a stochastic optimization procedure in order to maximize the battery duration while minimizing fuel crossover.

In the proposed circuit scheme, unlike semi‐empirical models, lumped circuit parameters are derived directly from mass transport and electric equations in order to fully describe the dynamic performance of the fuel cell. Physical and geometrical parameters are optimized in order to improve the system runtime. It is shown that a combined use of fuel cells and lithium batteries can improve the runtime of portable electronic devices compared to traditional supply systems based on lithium batteries only.

The one‐dimensional model of the micro fuel cell does not take into account possible transverse mass and electric charge flows in the fuel cell layers; most of the geometric and physics model parameters cannot be estimated from direct in situ or ex situ measurements.

Direct methanol fuel cells are nowadays a promising technology for replacing or complementing lithium batteries due to their high energy density. Most limiting features of direct methanol fuel cells are the fuel crossover and its slow oxidation kinetics. By using the proposed approach, fuel cell parameters can be optimized in order to enhance the discharge runtime and to reduce the methanol crossover.

The equivalent circuit model with optimized lumped non‐linear parameters can be used when designing power management units for portable electronic devices.

This paper aims to present an adaptation of digital image correlation (DIC) to the electronics industry for reliability assessment of electronic packages. Two case studies are presented: one for warpage measurement of a micro-electro-mechanical system (MEMS) package under different temperature conditions and the other for the measurement of transient displacements on the surface of a printed circuit board (PCB) assembly under free-fall drop conditions, which is for explaining the typical camera setup requirement and comparing among different boundary conditions by fastening methods of PCB.

DIC warpage measurements on a small device, such as a MEMS package, require a special speckle pattern. A new method for the creation of speckle patterns was developed using carbon coating and aluminum evaporative deposition. To measure the transient response on the surface of a PCB during a free-fall impact event, three-dimensional (3D) DIC was integrated with synchronized stereo-high speed cameras. This approach enables the measurement of full-field displacement on the PCB surface during a free-fall impact event, contrary to the localized information that is obtained by the conventional strain gage and accelerometer method.

The authors suggest the proposed patterning method to the small-sized microelectronics packages for DIC measurements. More generally, the idea is to have a thin layer of the dark or bright color of the background and then apply the white or black colored pattern, respectively, so that the surface has high contrast. Also, to achieve a proper size of speckles, this paper does not want to expose the measuring objects to high temperatures or pressures during the sample preparation stage. Of course, it seems a complicated process to use aluminum evaporator, carbon coater and electroformed mesh. However, the authors intend to share one of the solutions to achieve a proper pattern on such small-sized electronic packages.

3D DIC technique can be successfully implemented for the measurement of micro-scale deformations in small packages (such as MEMS) and for the analysis of dynamic deformation of complex PCB.

The purpose of this paper is to simulate passive proton exchange membrane fuel cells (PEMFCs) for portable electronic devices by means of a non‐linear lumped circuit based on electrical, mass transfer and electro‐kinetic equations.

Electrical, mass transfer and electro‐kinetic equations are combined in order to derive a non‐linear lumped circuit. The dynamic circuit model is tested in realistic operating conditions.

An original equivalent circuit model for simulating the transient behavior of passive PEMFCs is proposed. The PEMFC is represented as a non‐linear equivalent circuit with controlled lumped parameters depending on pressure, temperature, hydration, and system capacity.

Lumped parameters are synthesized assuming a one‐dimensional fuel cell model since layer thicknesses are much smaller than other dimensions. Heat generation and transfer are not modeled even though lumped parameters depend on temperature.

The proposed circuit model can be implemented directly in circuit simulators for designing power management units needed to interface small‐passive PEMFCs and portable electronics such as PDAs, laptops, or mobile phones.

The fuel cell is represented as a non‐linear controlled generator whose parameters are derived directly from multiphysics equations rather than empirical relationships. The dynamic behaviour of PEMFCs can be simulated on completely different times scales, i.e. during transients or during the discharge phase.

An innovative embedded chip MCM technology is being developed to address the packaging needs of the high volume, non‐military electronics industries. This development has evolved out of the GE High Density Interconnect (HDI) embedded chip MCM technology that was aimed at very high performance electronics in harsh military environments. In the HDI process, multiple bare chips are placed into cavities formed in a ceramic substrate and interconnected using an overlay polymer film, thin film metallisation and laser formed vias. Multiple levels of fine line (20 to 40 microns) interconnections and reference planes are used to form the circuit. In this new process, a plastic encapsulated substrate is formed by moulding a polymer resin around the bare die after placement on to a flat polymer film pre‐coated with an adhesive layer. After curing of the resin, the circuit is formed by patterning via holes through the polymer film to the components, metallising the polymer film and patterning the metal into the desired interconnect pattern. Feature sizes are readily scaled to the complexity needed by the circuit, permitting the use of lower cost and higher yield board photopatterning processes and equipment. This paper will cover the development of this low cost technology and will describe the process. It will also describe the thermal, mechanical and electrical features of this process and show actual working prototype modules.

Information and communication technologies (ICTs) have featured strongly in all the recent national foresight studies. This paper documents some of the common trends that emerge from a comparison of these different studies and attempts to draw some strategic conclusions. The first section charts their relative importance. The main trends identified in the national foresight studies are then discussed by main technological areas in turn: software, components and peripherals, advanced telecommunications and telematics applications. Finally, the third part of the paper, strong interactions that ICTs have with other technological disciplines is considered, especially in relation to new materials, nanostructures and bioinformatics.

At the beginning of 1990 I was given the honour of writing the editorial for the January issue of Circuit World as we started the countdown on the final decade leading up to the year 2000. The article was heavily laced with poetic phrases about the significance of the figure 2 in our lives and then went on to look at the development of electronics and the growing acceleration of the silicon industry.

Current technology uses large windmills that operate in remote regions and have complex generating mechanisms such as towers, blades gears, speed controls, magnets, and coils. In a city, wind energy that would otherwise be wasted can be claimed and stored for later use. The purpose of this paper is to introduce a small‐scale windmill that can work in urban areas.

The device uses a piezo‐composite generating element (PCGE) to generate the electric power. The PCGE is composed of layers of carbon/epoxy, lead zirconate titanate (PZT) ceramic, and glass/epoxy cured at an elevated temperature. Previous work by the authors had proved that the PCGE can produce high performance energy harvesting.

In the prototype, the PCGE performed as a secondary beam element. One end of the PCGE is attached to the frame of the device. Additionally, the fan blade rotates in the direction of the wind and hits the other end of the PCGE. When the PCGE is excited, the effects of the beam's deformation enable it to generate electric power. The power generation and battery charging capabilities of the proposed device were tested, and the results show that the prototype can harvest energy in urban regions using minor wind movement.

The paper presents a prototype that uses a PCGE for harvesting wind energy in urban areas. The PCGE has the potential of being used as a generator for harvesting energy from sources such as machine vibration, body motion, wind, and ocean waves. The PCGE design is flexible: the ply orientation and the size of the prepreg layers can be changed. Generating elements with a specific stacking sequence can be used for scavenging energy in a wide range of applications such as network sensors, portable electronics, and microelectromechanical systems.