• 한국전자파학회논문지
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• 제12권2호
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• pp.293-298
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• 2001

Polyaniline(EB)/NMP 용액에 carbonblack, grahpite Ag를 첨가하여 우수한 막질의 free standing film을 제조하였다. 1 mole HCI로 도핑된 polyaniline(ES) free standing film($\sigma$=5 S/cm, t=0.14 mm)을 제조하여 10 MHz~1 GHz의 주파수 영역에서 전자기파 차폐효과를 측정한 결과 23~25 dB의 차폐효율을 나타내었으며, carbonblack, grahpite, AG을 첨가하여 제조한 ES free standing film 과 camphorsulfonic acid(CSA)를 도핑한 polyaniline film의 전자기파 차폐효율 측정결과 각각 30~34dB, 36~42dB, 44~52dB, 34~43dB로 ES free standing film 보다 우수한 특성을 나타내었다.

• 폴리머
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• 제25권2호
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• pp.302-310
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• 2001

무전해도금법을 이용하여 구리/PET 필름 복합재료를 제조하였으며 에칭방법과 촉매액의 조성 및 acceleration 방법을 달리하여 PET 필름과 무전해도금된 구리 피막간의 접착력을 향상시키고자 하였다. HCl 용액으로 에칭된 PET 필름은 NaOH에 의한 것보다 더욱 세밀하게 에칭되어져 구리와 PET 필름간의 접착력은 향상되었으나 전자파 차폐효과는 유사한 경향을 보였다. 촉매액의 조성변화에 따른 영향을 살펴본 결과 PdCl$_2$:SnCl$_2$의 몰비가 1:4에서 1:16으로 증가할수록 PET 필름 위에 적층된 Pd/Sn 콜로이드 입자들의 크기가 감소하며 고르게 분포되는 경향을 보였다. 따라서 이들의 몰비가 증가할수록 구리도금이 균일하고 조밀하게 이루어져 접착력 및 차폐효과가 증가하였다. 또한 NaOH보다 HCl로 acceleration한 경우 촉매 입자의 크기가 작고 더 균일하게 분포되어 우수한 접착력과 도금물성을 나타내었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2011년도 춘계학술대회 및 Fine pattern PCB 표면 처리 기술 워크샵
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• pp.205-206
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• 2011

Cu thin films for electromagnetic wave shielding were prepared on PET film and Ni-coated PET film by using Dry and Wet coating method, such as evaporation method, DC sputtering method and copper sulfate($CuSO_4$). After that, Zn thin film and Ni thin film were prepared onto the Cu thin films by using evaporation dry process and Ni electro plating wet process as a finishing treatment, respectively. The result of conductivity test and corrosion resistance test revealed Cu thin films which were formed with bigger grain size and high Cu composition rate have superior properties. Zn thin film by dry evaporation process and Ni thin film by wet electro plating process on Cu thin films were largely contributed to corrosion resistance. However, Ni thin film by wet process made conductivity of all specimen worse, the other hand, Zn thin film by dry process made it better to improve condictivity of specimens just prepared by dry process.

• 한국의류학회지
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• 제27권7호
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• pp.843-850
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• 2003

Cu/PET film composites were prepared by electroless copper plating method. In order to improve adhesion between electroless plated Cu layer and polyester (PET) film, the effect of pretreatment conditions such as etching method, mixed catalyst composition were investigated. Chemical etching and plasma treatment increased surface roughness in decreasing order of Ar＞HCl＞O$_2$＞NH$_3$. However, adhesion of Cu layer on PET film increased in the following order: $O_2$＜Ar＜HCl＜NH$_3$. It indicated that appropriate surface roughness and introduction of affinitive functional group with Pd were key factors of improving adhesion of Cu layer. PET film was more finely etched by HCI tolution, resulting in an improvement in adhesion between Cu layer and PET film. Plasma treatment with NH$_3$produced nitrogen atoms on PET film, which enhances chemisorption of Pd$^{2+}$ on PET film, resulting in improved adhesion and shielding effectiveness of Cu layer deposited on the Pd catalyzed surface. Surface morphology of Cu plated PET film revealed that Pd/Sn colloidal particles became more evenly distributed in the smaller size by increasing the molar ratio of PdCl$_2$; SnCl$_2$from 1 : 4 to 1 : 16. With increasing the molar ratio of mixed catalyst, adhesion and shielding effectiveness of Cu plated PET film were increased.d.

• 전기전자학회논문지
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• 제23권3호
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• pp.756-761
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• 2019

본 논문에서는 기존 4H-SiC SJ UMOSFET 구조의 p-pillar을 기존 UMOSFET의 shielding 영역 아래로 배치시키는 SC-SJ(Shielding Connected-Super Junction) UMOSFET 구조를 제안한다. 제안한 SC-SJ UMOSFET의 경우 p-pillar와 shielding 영역이 공존하여 산화막에서 전계에 의한 항복이 발생하지 않도록 하며, 이는 pillar의 도핑 농도 상승을 가능하게 한다. 결과적으로 온저항을 낮춤으로서 소자의 정적 특성을 개선한다. Sentaurus TCAD 시뮬레이션을 통해 기존 구조와 제안한 구조의 정적 특성을 비교, 분석하였다. 제안한 SC-SJ UMOSFET은 기존 구조에 비해 항복전압의 변화 없이 50% 감소된 온저항을 얻을 수 있다.

• 마이크로전자및패키징학회지
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• 제28권1호
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• pp.21-29
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• 2021

Recently, semiconductor chips and electronic components are increasingly being used in IT devices such as wearable watches, autonomous vehicles, and smart phones. As a result, there is a growing concern about device malfunctions that may occur due to electromagnetic interference being entangled with each other. In particular, electromagnetic wave emissions from wearable or flexible smart devices have detrimental effects on human health. Therefore, flexible and transparent electromagnetic interference (EMI) shielding materials and films with high optical transmittance and outstanding shielding effectiveness have been gaining more attention. The EMI shielding films for flexible and transparent electronic devices must exhibit high shielding effectiveness, high optical transmittance, high flexibility, ultrathin and excellent durability. Meanwhile, in order to prepare this EMI shielding films, many materials have been developed, and results regarding excellent EMI shielding performance of a new materials such as carbon nano tube (CNT), graphene, Ag nano wire and MXene have recently been reported. Thus, in this paper, we review the latest research results to EMI shielding films for flexible and transparent device using the new materials.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.59-60
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• 2022

When a metal sprayed film of several hundred ㎛ on the concrete surface is possible to 80 dB of shielding effect electromagnetic waves (ElectroMagnetic Pulse, EMP). Therefore, in this study, as a way to secure EMP shielding performance by applying a metal spray coating showing excellent EMP shielding performance to a concrete structure, the metal spray welding efficiency and thin film adhesion performance according to the concrete spray direction and surface treatment method were evaluated. Metal sprayed efficieny according to the metal spraying direction and method was confirmed that the difference was insignificant by applying the roughening agent. However, the method of strengthening the concrete surface and applying the sealing agent show maximum adhesion strength of 3.98 MPa compared to other methods, and it is judged that this method can be utilized for the metal spraying method for concrete EMP shielding.

• 한국인터넷방송통신학회논문지
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• 제19권2호
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• pp.59-65
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• 2019

노이즈 소스의 근거리장에 저전도율 차폐막이 놓여있을 때 차폐막 두께에 따른 EMI 차폐효과를 분석하였다. 노이즈 소스로는 광대역 특성을 갖는 나선형 안테나를 이용하였으며, 저전도율 차폐 재료로는 그래파이트를 선정하였다. 나선형 안테나 두 개를 만들어 두 안테나 사이의 투과계수를 분석하였고, 송수신 안테나 사이의 거리는 5 cm와 10 cm인 두 경우에 대해 수행하였다. 차폐막의 두께는 1 um에서 200 um까지 변화시켰다. 주파수는 100 MHz에서 6 GHz까지 변화시켜 최대 70 dB의 SE(Shielding Effectiveness)를 얻었다. 본 시뮬레이션에서는 차폐막 재료인 그래파이트의 특성상 전기적 차폐(electronic shielding)를 이용하였다. 이 결과를 바탕으로 향후 자기 차폐를 구현하여 차폐 성능을 향상시킬 수 있는 방법을 연구할 예정이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.932-934
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• 2002

In this paper, we proposed a method to shield perpendicular magnetic fields in high Tc superconductor(HTS) tape of a shell-type HTS transformer with double pancake windings. A diamagnetism of characteristics of superconductor is used to shield magnetic field. For a shielding experiment, a proper shielding model is chosen, and several kinds of HTS are used such as a monofilament HTS tape, two kinds of multifilament HTS tapes and YBCO film disk. The effect of shielding for the perpendicular magnetic field is measured with HTSs for shielding and their utility for shielding is proved.

• 한국전기전자재료학회논문지
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• 제11권1호
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• pp.1-6
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• 1998

Polyaniline free standing films are prepared by various processing. The properties of these films such as electrical conductivity and electromagnetic shielding efficiency are investigated. The conductivities of films doped with a camphorsulfonic acid and a silver are found to be 170/cm and 190S/cm, respectively, indicating metallic behavior. The films added silver, which are casted from hydrochloric acid and dodecylbenzensulfonic acid, show that the electromagnetic shielding efficiency are obtained 42∼52dB and 46∼56dB in the frequency range of 10MHz∼1GHz, respectively. This suggests that the films added silver, which is casted from dodecylbenzensulfonic acid, can be used as electromagnetic shielding material.