• 제목/요약/키워드: Protective Film

검색결과 259건 처리시간 0.03초

교류형 PDP 보호막용 MgO-CaO 박막의 광학적 특성과 전기적 특성 (Optical and Electrical Properties of MgO-CaO thin films as a Protective Layer for AC PDPS)

  • 조진희;김락환;박종완
    • 한국재료학회지
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    • 제9권6호
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    • pp.547-550
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    • 1999
  • Optical and electrical properties of MgO-CaO films as a protective layer for AC plasma display panel were studied. When the [(CaO/(MgO+CaO)] ratio of evaporation starting materials was optimum composition, 0.1, firing voltage and memory margin of the film were 176V and 0.5, respectively. When [CaO/(CaO+MgO)] was 0, 0.1 and 0.2, memory margin was 0.39, 0.5 and 0.41, respectively, and surface roughness of films was $27.7\AA$, $21.1\AA$ and $40.3\AA$, respectively. It was thought that memory margin had a reverse-relation with surface roughness. The density of film was calculated by measuring the refractive index of film. The density of MgO film was 3.21g/㎤ and the density of film, when [CaO/(CaO+MgO)] was 0.1, was 3.632g/㎤. The mixture of MgO-CaO films showed a good transmittance property in the visual range.

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LTCC 보호층 형성에 따른 박막 전극패턴에 관한 연구 (Effect of Protective layer on LTCC Substrate for Thin Metal Film Patterns)

  • 김용석;유원희;장병규;박정환;유제광;오용수
    • 한국재료학회지
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    • 제19권7호
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    • pp.349-355
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    • 2009
  • Metal thin film patterns on a LTCC substrate, which was connected through inner via and metal paste for electrical signals, were formed by a screen printing process that used electric paste, such as silver and copper, in a conventional method. This method brought about many problems, such as non uniform thickness in printing, large line spaces, and non-clearance. As a result of these problems, it was very difficult to perform fine and high resolution for high frequency signals. In this study, the electric signal patterns were formed with the sputtered metal thin films (Ti, Cu) on an LTCC substrate that was coated with protective oxide layers, such as $TiO_2$ and $SiO_2$. These electric signal patterns' morphology, surface bonding strength, and effect on electro plating were also investigated. After putting a sold ball on the sputtered metal thin films, their adhesion strength on the LTCC substrate was also evaluated. The protective oxide layers were found to play important roles in creating a strong design for electric components and integrating circuit modules in high frequency ranges.

방식도막에 있어서 물의 침투에 대한 전해질 용액의 영향 (Effect of Electrolyte Concentration on Water Permeation in Protective Coatings)

  • 박진환
    • 한국안전학회지
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    • 제13권4호
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    • pp.206-212
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    • 1998
  • The water permeation in protective coatings, which may greatly influence the corrosion protective property of these coatings, was studied using the electrochemical impedance spectroscopy technique. During the absorption of water in protective coatings immersed in electrolyte solution, the change of coating capacitance with concentration of electrolyte was determined from impedance measurements. When water absorption or desorption of coatings occured by exposing the coatings to electrolyte solutions of different concentration, increase in impedance caused by desorption of water was found to be higher in the case of thicker film. The amount of water absorbed in coatings changed with concentration of electrolyte. The water taken up in coatings from the solution of lower electrolyte concentration was deserted by contact with the solution of higher concentration. The uptake of water in protective coatings varied depending on the type of coating ingredient especially binder.

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이중보호막 모델을 이용한 보호막의 형성과 표면파괴에 관한 연구 (A Study on Scuffing and the Formation of the Protective Layers Based on Dual Film Formation)

  • 이영제
    • Tribology and Lubricants
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    • 제8권2호
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    • pp.14-19
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    • 1992
  • rate of growth of "protective" films of oxides and compounds derived from the lubricant. The protection afforded by the films is strongly dependent on lubricant and steel composition, initial composite surface roughness and the load/speed sequence or history in the early stages of sliding. The protective films, formed by chemical and mechanical action between lubricant and mating surfaces, delayed the surface roughening and offered higher load capacity. Given the great number of variables involved it is not possible to follow more than a few of the chemical changes on surfaces at the end of experiments. Ellipsometry was therefore used to monitor the formation and loss of dual protective films in real time, and also to find the effect of protective films on scuffing and break-in depending on lubricant conditions.

연성 플라스틱 기판위에 스프레이 코팅방법으로 제조한 유·무기 보호막의 특성 (Properties of Organic-Inorganic Protective Films on Flexible Plastic Substrates by Spray Coating Method)

  • 이상희;장호정
    • 마이크로전자및패키징학회지
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    • 제24권4호
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    • pp.79-84
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    • 2017
  • 태양전지와 같은 광전소자의 특성 및 신뢰성 유지하기 위해서는 수분과 산소 등으로 부터 소자 내부가 보호되어야 한다. 본 연구는 여러 연성(flexible) 플라스틱 기판위에 유 무기 복합 보호막을 스프레이코팅 방법으로 형성하여 공정조건(노즐 위치, 박막 두께, 기판 구성)에 따른 소자의 보호특성을 연구하였다. 사용된 복합 보호막 재료로서 PVA (polyvinyl alcohol)와 SA(sodium alginate) 혼합 유기 물질(P.S)에 $Al_2O_3$($P.S+Al_2O_3$)과 $SiO_2$($P.S+SiO_2$) 나노 분말을 혼합하여 유 무기 복합 보호막 용액을 합성하였다. 플라스틱 기판 위에 코팅한 보호막의 두께가 $5{\mu}m$에서 91%의 투과율을 나타내었으며 $78{\mu}m$에서 $178{\mu}m$로 두께가 증가할 경우 광 투과율은 81.6%에서 73.6%으로 감소하였다. 또한 합성한 $P.S+Al_2O_3$ 복합재료를 사용하여 PEN(polyethylene naphthalate), PC(polycarbonate) 단일 플라스틱 기판과 Acrylate film과 PC 이중막(Acrylate film/PC double layer) 구조와 $Al_2O_3$ 무기박막과 PEN 이중막($Al_2O_3$ film/PEN double layer) 구조의 기판 위에 $P.S+Al_2O_3$ 용액을 사용하여 수분투과도(water vapor transmission rate, WVTR)와 표면형상 등을 측정하여 최적의 보호막 구조를 확인하였다. 즉, $Al_2O_3$ film/PEN 이중막 기판위에 형성한 보호막의 수분투과 값은 $0.004gm/m^2-day$로 가장 우수한 내 투습 특성을 나타내었다.

OBSERVATION OF THE MAGNETIC DOMAIN IN THIN-FILM HEADS BY ELECTRON MICROSCOPY

  • Kobayashi, Kazuo
    • 한국자기학회지
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    • 제5권5호
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    • pp.710-715
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    • 1995
  • Magnetic domains were observed using an image lock-in technique for backscattered electron contrast (Type II) with a 200 kV scanning electron microscope. Backscattered electrons indicate a difference in magnetic domain structures at the upper and lower parts of the upper pole in thin-film heads, changing the acceleration voltage. With this method, it is also possible to observe the domain structure of the thin-film head pole through a 10 to $20\;\mu\textrm{m}$ protective layer, and the upper shield of the MR head through the coil in the resist, alumina overcoat, and upper pole.

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마그네슘 합금 용탕 표면 산화 및 발화에 대한 $C_2Cl_6$의 영향 (The Effect of $C_2Cl_6$ Addition on Surface Ignition and Oxidation of Molten AM100A Mg alloy)

  • 최승화;김대환;김희경;심성용;임수근
    • 한국주조공학회지
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    • 제30권6호
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    • pp.231-234
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    • 2010
  • The effect of $C_2Cl_6$ for preventing to the surface oxidation and ignition of molten Mg alloy was studied with metallographic analysis, X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The alloy used for this study was AM100A Mg casting alloy with high strength. In order to investigate the surface protective characteristic of this molten alloy by $C_2Cl_6$ addition, we added them into molten AM100A alloy at $700^{\circ}C$ and then the melts were slowly cooled under a protective atmosphere of air containing Ar gas and $C_2Cl_6$ flux addition. The result found that the surface oxidation and ignition reaction of molten AM100A Mg alloy by adding $C_2Cl_6$ flux was more slowly occurred than that of the only a protective atmosphere of containing Ar gas with increasing time. This result was due to a dense protective film formed containing $MgCl_2$ on surface of molten Mg alloy during casting and solidification. The $MgCl_2$ was formed by a reaction of $C_2Cl_6$ with molten Mg.

Electrochemical Properties of Air-Formed Oxide Film-Covered AZ31 Mg Alloy in Aqueous Solutions Containing Various Anions

  • Fazal, Basit Raza;Moon, Sungmo
    • 한국표면공학회지
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    • 제50권3호
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    • pp.147-154
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    • 2017
  • This research was conducted to investigate the electrochemical properties of the thin air-formed oxide film-covered AZ31 Mg alloy. Native air-formed oxide films on AZ31 Mg alloy samples were prepared by knife-abrading method and the changes in the electrochemical properties of the air-formed oxide film were investigated in seven different electrolytes containing the following anions $Cl^-$, $F^-$, $SO{_4}^{2-}$, $NO_3{^-}$, $CH_3COO^-$, $CO{_3}^{2-}$, and $PO{_4}^{3-}$. It was observed from open circuit potential (OCP) transients that the potential initially decreased before gradually increasing again in the solutions containing only $CO{_3}^{2-}$ or $PO{_4}^{3-}$ ions, indicating the dissolution or transformation of the native air-formed oxide film into new more protective surface films. The Nyquist plots obtained from electrochemical impedance spectroscopy (EIS) showed that there was growth of new surface films with immersion time on the air-formed oxide film-covered specimens in all the electrolyte. The least resistive surface films were formed in fluoride and sulphate baths whereas the most protective film was formed in phosphate bath. The potentiodynamic polarization curves illustrated that passive behaviour of AZ31 Mg alloy under anodic polarization appears only in $CO{_3}^{2-}$, or $PO{_4}^{3-}$ ions containing solutions and at more than $-0.4V_{Ag/AgCl}$ in $F^-$ ion containing solution.

N2O 반응 가스를 주입한 RF Reactive Magnetron Sputtering에 의한 ZrO2 박막의 구조 및 부식특성 연구 (Structural and Corrosive Properties of ZrO2 Thin Films using N2O as a Reactive Gas by RF Reactive Magnetron Sputtering)

  • 지승현;이석희;백종혁;김준환;윤영수
    • 한국세라믹학회지
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    • 제48권1호
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    • pp.69-73
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    • 2011
  • A $ZrO_2$ thin film as a corrosion protective layer was deposited on Zircaloy-4 (Z-4) clad material using $N_2O$ as a reactive gas by RF reactive magnetron sputtering at room temperature. The Z-4 substrate was located in plasma or out of plasma during the $ZrO_2$ deposition process to investigate mechanical and corrosive properties for the plasma immersion. Tetragonal and monoclinic phases were existed in $ZrO_2$ thin film immersed in plasma. We observed that a grain size of the $ZrO_2$ thin film immersed in plasma state is larger than that of the $ZrO_2$ thin film out of plasma state. In addition, the corrosive property of the $ZrO_2$ thin films in the plasma was characterized using the weight gains of Z-4 after the corrosion test. Compared with the $ZrO_2$ thin film immersed out of plasma, the weight gains of $ZrO_2$ thin film immersed in plasma were larger. These results indicate that the $ZrO_2$ film with the tetragonal phase in the $ZrO_2$ can protect the Z-4 from corrosive phenomena.

A Novel Under-film Corrosion Tester Using Current Interrupter Technique

  • Tanabe, Hiroyuki;Taki, Tohru;Nagai, Masanori;Ogawa, Osamu
    • Corrosion Science and Technology
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    • 제3권6호
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    • pp.240-244
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    • 2004
  • Recently a variety of electrochemical techniques have been used for the measurement of under-film corrosion of coated steel. Each method has its own characteristic and is suitable to determine some kinds of anti-corrosive mechanisms of coating film. We developed a new under-film corrosion tester (UFCT) which adoped current interrupter technique in principle. Electrochemical parameters can be measured by UFCT. It is possible for the novel under-film corrosion tester to evaluate under-film corrosion of steel covered with high electric resistance coating film which has no defect and is not easy to evaluate it by other methods. Finally some experimental results of protective coating performance obtained by UFCT were discussed.