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Thermosetting polymers are widely used in electronic packaging. For instance, epoxy molding compound is extensively used as an encapsulant for electronic packages to protect the IC chips from mechanical and chemical hazards. It is well known that molding compounds show not only strong temperature dependent but also time dependent behavior. The thermo-mechanical behavior of these polymer constituents...
Interfacial delamination is known as one of the root causes of failure in microelectronic industry. In order to explore the risk of interface damage, FE simulations for the fabrication steps as well as for the testing conditions are generally made in the design stage. In order to be able to judge the risk for interface fracture, the critical fracture properties of the interfaces being applied should...
Epoxy resin systems are used in high voltage transformers, cable terminations, bushings, power apparatus, or insulation for X-ray tubes. They could be used more widely, but low thermal conductivity limits their applications. Polymers used as insulating materials generally lack the ability to dissipate excess heat efficiently. The aim of this study is to investigate the influence of different types...
For the application of nanocomposite materials to solid insulator in electric power apparatus, we investigated the influence of the dispersibility of nanoparticles on dielectric property. Experiments were carried out in epoxy/alumina nanocomposites with the particle dispersion techniques using ultrasonic wave and centrifugal force. As the result, we verified the specific characteristics of dielectric...
Under DC voltage stress, a negative hetero-charge is generated near the positive electrode in cables insulated with cross-linked polyethylene (XLPE). The generation of negative hetero-charges in XLPE-insulated cable results from cross-linking byproducts, antioxidants, and moisture. Among these inclusions, moisture is known to originate from dehydration of a-methyl styrene, which is a byproduct produced...
To understand treeing phenomena in MgO/LDPE nanocomposite under ac voltage application, treeing breakdown properties and partial discharge inception voltage were investigated. Tree inception voltage increased with increasing filler content. Time to bridge counter electrode, time to breakdown and time-lag to breakdown also increased with addition of MgO nano-filler to LDPE. From these results, it becomes...
Water and chloroform extracts of various Chinese medicinal insects were added into the medium of Ganodermasinense to investigate the effects of the extracts on production of biomass, intracellular polysaccharides (IPS), and extracellular polysaccharides (EPS). The results showed that chloroform extract of E. sinensis (CES) at 55 mg/L lead to significant increase in both biomass and IPS concentration...
In this study, the dynamic behavior of the sandwich panels subjected to the impact load are investigated experimentally and numerically. For this purpose, the sandwich panels are manufactured using the honeycomb core material and laminated composite face sheets. The face sheet materials used in this study are manufactured using an aramid fabric and epoxy resin. The wet hand lay-up technique is used...
Microsphere particles have been introduced in a wide range of bio-medical applications, such as controlled drug delivery system and tissue repair materials. Microspheres can be produced in many ways including emulsion and stirring. These traditional methods have many restrictions such as large microspheres, production of air bubbles in the microspheres, uneven size and uneven morphology. All these...
In the present study, poly (D, L-lactic acid) (PDLLA) modified genipin-cross-linked chitosan/gelatin scaffolds loaded icariin were prepared. The scaffolds with genipin cross-linking were fabricated with lyophilization, and then were immersed into the 2.5%, 5.0%, and 7.5% PDLLA-dichloromethane solutions. Thus the PDLLA modified genipin-cross-linked scaffolds were obtained after evaporating the solvent...
The critical challenges of removal of post metal hard mask etch photo resist removal and post low-k etch residue removal are described. An overview of some new non-plasma based approaches is presented.
Photovoltaic (PV) modules operate in an extreme environment and are exposed to radiation, humidity, and hot and cold thermal extremes. This paper focuses on polymeric-material degradation during PV-module operation at high ambient temperatures, high solar irradiance and low wind speed. The 2004 version of the IEC 61730 specification requires all polymeric materials used in a photovoltaic module to...
CdSe nanoparticles combined with electron accepting materials, specifically methyl viologen (MV2+) and single walled carbon nanotubes (SWCNT), have been investigated. By using transient absorption spectroscopic measurements, ultrafast electron transfer has been shown to occur between the nanoparticles and the accepting materials. These composites were then mixed with poly(3-hexylthopene) to create...
Numerical modeling of organic bulk heterojunction (BHJ) solar cells has been undertaken using the AMPS computer code and material parameters representative of the P3HT/PCBM cell. These simulations show that the VOC and thus the efficiency of these BHJs is currently controlled by interface recombination. These results show VOC tracks with the HOMO (D) - LUMO (A) difference with a relationship of the...
For realizing an active smart RFID label monitoring mechanical shock and inclination during transport processes, a capacitive inertial sensor has been developed. Hermetic sealing of the microstructures has been done by a wafer level thin film encapsulation technology based on CF-polymer as sacrificial layer material and a stress-optimized dielectric layer stack as capping material. Long term stability...
We propose a heat flow sensing device with a heat source to discriminate a contact object. The device was a three-layered structure separated by 600 mum-thick PDMS (Polydimethylsiloxane) spacer, and consisted of a micro heater and three resistance-temperature detectors (RTD). We detected transient heat flow with pulse-heating method when 10 mm-cubic blocks of cork, acrylic and aluminum were on contact...
A key component of pulse power technology is the engineering of these complicated structures. The goal of this work is to develop a finite element model that captures the complex physical interactions of all components within the Z machine. A large driver of physical motion in this machine is not found at the target but rather upstream at the water switches. Where this high current passes through...
At sufficiently high DC electric field in polymer insulation breakdown will occur due to heating. The current that passes through the insulation depends on the electric field, the temperature, and the composition. The associated temperature rise depends on the thickness of the insulation layer and the thermal boundary conditions. A numerical model has been used to study the temperature and electric...
In this paper preliminary results regarding a vibrating tactile sensor are presented. More specifically, two IPMC strips are used, one as actuator and one as sensor, that work together for the differentiation of tissues. In fact, the characteristics of the resonant vibrating IPMC system change with the applied load. This allows for calculating the parameters of the mechanical load, by measuring the...
Thermoplastic composites are widely used in various areas. In several cases their applicability is determined by their mechanical properties that depend on the proper mixing of the component polymeric materials. In this paper two low complexity fuzzy models are presented that have been developed for the prediction of Charpy impact strength and yield strength as a function of the percent amount of...
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