• 한국안전학회지
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• 제19권4호
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• pp.80-85
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• 2004

Electromagnetic interference(EMI) shielding characteristics of composite filled with Cu flake and carbon brush powder as hybrid conductive filler and EAF slag have been studied. The coaxial transmission line method of ASTM D4935-99 was used to measure the EMI Shielding effectiveness of composites as formulation in frequency rage $100\~1,000MHz$ The SE also increases with the increase in flier loading. The hybrid filler filled composites show higher SE compared to that of only Cu flake. The correlation between SE and conductivity of the various composites is also discussed. The results indicate that the composites having higher filler loading$({\geq}40wt.\%)$ can be used for the purpose of safety materials to protect hazardous electromagnetic interference.

• 한국분말재료학회지
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• 제21권2호
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• pp.124-130
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• 2014

The automotive industry is moving from the internal combustion engine to electric drive motors. Electric motors uses a high voltage system requiring the development of resources and components to shield the system. Therefore, in this study, we analyze electromagnetic interference (EMI) shielding effectiveness (SE) characteristics of an auto crash pad according to the ratio of electrically conductive materials and propylene. In order to combine good mechanical characteristics and electromagnetic shielding of the automotive crash pad, metal-coated glass fiber (MGF) manufacturing methods are introduced and compared with powder-type methods. Through this study, among MGF methods, we suggest that the chopping method is the most effective shielding method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1121-1124
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• 2002

Currently, the regulation system on controlling EMI has been strengthened throughout the world and this system has emerged as another invisible barrier from the advanced countries. Such a regulation is likely to expand in many various ways depending on the objective and type, and there has to be a fundamental EMI measure to respond this movement. This study is aimed at learning the EMI technology of communication system through the shielding material. It introduces the selection of appropriate shielding material and method of use, and it introduces the cases that resolved the actual EMI problem of the system that is manufactured by the company.

• 전자통신동향분석
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• 제35권4호
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• pp.11-20
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• 2020

With the widespread use of high-performance electronics and mobile communications, electromagnetic interference (EMI) shielding has become crucial for protection against malfunctioning of electronic equipment and harmful effects to human health. In addition, smart sensor technologies will be rapidly developed in untact (non-contact) environments and personal healthcare fields. Herein, we introduce our recently developed technologies for flexible multifunctional EMI shielding, and highly sensitive wearable pressure-strain and humidity sensors realized using low-dimensional nanomaterials.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.33-36
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• 2003

AC and DC conductivity of the MWNT(Multi walled nanotubes)/polyurethane composites were investigated with respect to the various oxidative conditions, where these means acid concentration, treatment temperature, and treatment time. We suppose that the conditions of oxidation of the MWNTS have a certain influence on the degree of functionalization, damages, and dispersion of the MWNT themselves. Futhermore, the electrical properties of the resulting composites strongly depend on the oxidative conditions of MWNTS. The conductivity of the composites produced by using the optimal condition was measured as a function of frequency with volume content of MWNTS. These experimental results were analyzed using percolation theory Electromagnetic interference shielding effectiveness (SE) of the mixtures of polyurethane (PU), optimized MWNTs, and silver (Ag) is measured in the frequency range from 10 MHz to 6 ㎓ by using ASTM D4935-89. The measured SEs of the mixtures could be controlled from about 55 dB to 85 dB with the compositions of Ag/MWNT and compounding methods(C1, C2).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.833-836
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• 1997

Magnesium alloys are one of light weight material. Strength and stiffness of Magnesium alloys are enough to use for commercial product. Demand for strong, lightweight parts several computer and electronics have driven much of Magnesium injection molding's growth so far. And it is eighth most abundant resource on earth. In electronic device, electromagnetic interface and electrostatic discharge can affect performance. Magnesium injection molding is similar to normal plastic injection molding process. But some process condition is different. Especially injection speed and process temperature are so differs from other injection molding system. It just start for make something. But Magnesium injection molding is one of best alternate process for producing metal alloy part.

• 한국염색가공학회지
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• 제10권2호
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• pp.8-17
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• 1998

In this study we have examined electroless chemical plating on the plasma grafted poly [ethylene terephathalate］(PET) fabric in order to improve the interfacial adhesion between metal and fiber. The vapour phase of acrylic acid introduced on the PET surface and the graft polymerization was carried out by using cold plasma, resulting in the grafting yield of 0.8-1.3 wt％. The carboxyl group of the plasma grafted was identified by FT-IR-ATR spectra. The Interfacial adhesion was related to the carboxyl group. After electroless chemical plating of nickel, it showed that the more the carboxyl, the better the interfacial adhesion. Comparing to the untreated, the plasma grafted fabric showed fairly good interfacial adhesion(5B grade, ASTM D3359) . The shielding effect of electromagnetic wave showed 95dB. The shielding effect depends on the fabric structure, the surface structure, and the cross sectional shape of fibers. The dense fabric structure, the etched surface like a microcrater, and the trigonal cross sectional shape were prefered.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1591-1593
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• 1996

The experimental study was carried out to investigate the effects of metallic particulate filler on the mechanical properties and the thermal properties of epoxy resin system filled with Cu powder. As Cu contents increased, the tensile strength, surface hardness and $T_d$ decreased. $T_g$ increased and decreased at 300 phr. $E_d$ decreased and increased at 200 phr, because the thermal conducting path of filler was formed and dissipated thermal stress.

• 한국표면공학회지
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• 제38권6호
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• pp.212-215
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• 2005

Novel continuous electroforming process equipped with a rotating patterned mandrel, soluble/insoluble anode and multiple stage of rolling wheels was proposed to produce precision nickel mesh, which is known as a very efficient electromagnetic interference (EMI) shielding material. Continuously electroformed nickel deposits showed a tendency to form small-sized particles as the plating solution temperature increased and mandrel rotation speeded up and the applied current density decreased. Along the honeycomb patterns of mandrel, nickel was accurately electrodeposited on the surface of rotating mandrel, but quite different visual/structural characteristics were measured on both sides.

• 한국표면공학회지
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• 제48권4호
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• pp.149-157
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• 2015

We investigated the effects of the fabric structure or the kinds of plated metals on the electromagnetic interference shielding effectiveness (EMI SE) by means of electroless plating on polyester fabric. We found that the weight of deposited metal, EMI SE, and flexibility of the conductive fabric for EMI shield is affected by morphology of fabric and structure of fiber. The EMI SE of conductive fabric plated Ni/Cu/Ni by electroless plating method on draw textured yarn (DTY) polyester was in the practically useful range of above 70 dB over a wide frequency range of 10 MHz to 1.0 GHz at the surface resistivity of $0.05{\Omega}/{\square}$. Au or Ag plated conductive fabric by immersion plating method is not able to provide for a good EMI SE.