Nanowire-based gas sensors

Gas sensors fabricated with nanowires as the detecting elements are powerful due to their many improved characteristics such as high surface-to-volume ratios, ultrasensitivity, higher selectivity, low power consumption, and fast response. This paper gives an overview on the recent process of the development of nanotechnology and nanowire-based...

An introduction to system reliability for solid-state lighting

Solid-State Lighting (SSL) applications are slowly but gradually pervading into our daily life. An SSL system is composed of an light-emitting diode (LED) engine with a microelectronic driver(s) in a housing that also supplies the optic design. Knowledge of system-level reliability is crucial for the business success of future SSL systems, and...

Solid-state lighting technology in a nutshell

Solid-state lighting (SSL) is the most promising energy saving solution for future lighting applications. SSL is digital and multi-scaled in nature: SSL is based on the semiconductor-based LED and its packaging technology. The LED module can be obtained by cooperation of electronic devices. By integrating the hardware and software, the luminaire...

Degradation mechanisms in LED packages

Lumen depreciation is one of the major failure modes in light-emitting diode (LED) systems. It originated from the degradation of the different components within the package, being the LED device or chip, the driver, and the optical materials (including phosphorous layer). This chapter describes the state of the art of the degradation mechanism...

Molecular modeling of protonic acid doping of emeraldine base polyaniline for chemical sensors

We proposed a molecular modeling methodology to study the protonic acid doping of emeraldine base polyaniline which can used in gas detection. The commercial forcefield COMPASS was used for the polymer and protonic acid molecules. The molecular model, which is capable of representing the polyaniline doping with the aqueous hydrochloric acid, was...

Molecular modeling of the conductivity changes of the emeraldine base polyaniline due to protonic acid doping

We propose a molecular modeling strategy, which is capable of predicting the conductivity change of emeraldine base polyaniline polymer due to different degree of protonic acid doping. The method is comprised of two key steps: (1) generating the amorphous unit cells with given number of polymer molecules and different concentration of H + ions...

Characterization of intermetallic compounds in Cu-Al ball bonds: Mechanical properties, delamination strength and thermal conductivity

Evaluation and selection of sensing materials for carbon dioxide (CO 2) sensor by molecular modeling

We report a molecular modeling study to evaluate and select conducting polymers (CPs) as the sensing materials of carbon dioxide (CO2) sensor. The interaction between polymer and gas and the adsorption of the gas molecules in the polymer matrix are investigated. Polymers considered for this work include emeraldine base polyaniline (EB-PANI) and...

Validation of forcefields in predicting the physical and thermophysical properties of emeraldine base polyaniline

We report a molecular modelling study to validate the forcefields [condensed-phase optimised molecular potentials for atomistic simulation studies (COMPASS) and polymer-consistent forcefield (PCFF)] in predicting the physical and thermophysical properties of polymers. This work comprises of two key steps: (1) generating and validating the...

Overview on thermal and mechanical challenges of high power RF electronic packaging

High Power RF electronics is one of the essential parts for wireless communication, including the personal communication, broadcasting, microwave radar, etc. Moreover, high efficient high power electronics has entered the ISM market, such as the power generator of microwave oven. Power electronics requires a close co-development of digital...

FE modeling of Cu wire bond process and reliability

Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond pad structure is required. It also refers to...

Modelling aluminium wire bond reliability in high power OMP devices

In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is preferred and wedge-wedge wire bonding is widely used....

High power electronics package: From modeling to implementation

Power electronics, such as high power RF components and high power LEDs, requires the combination of robust and reliable package structures, materials, and processes to guarantee their functional performance and lifetime. We started with the thermal and thermal-mechanical modeling of such component performances. With robust validation....

LED system reliability

This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific exercise but it is also crucial for successful...

Thermo-mechanical model optimization of HB-LED packaging

Lighting is an advancing phenomenon both on the technology and on the market level due to the rapid development of the solid state lighting technology. The efforts in improving the efficacy of high brightness LED's (HB-LED) have concentrated on the packaging architecture. Packaging plays a significant role in reliability; not only on mechanical...

Forcefields based molecular modeling on the mechanical and physical properties of emeraldine base polyaniline

Molecular dynamics (MD) and molecular mechanical (MM) analysis are carried out to provide reliable and accurate model for emeraldine base polyaniline. This study validate the forcefields and model with the physical and mechanical properties of the polyaniline. The temperature effects on non-bond energy, potential energy and solubility parameter...