• 한국표면공학회지
• /
• 제50권5호
• /
• pp.373-379
• /
• 2017

Dry processes like evaporation and sputtering in vacuum chamber are difficult to make a uniform, large area and high quality film on thin PET substrate because of PET degradation and bad adhesion. On the other hand, wet processes like electro or electroless plating have complex processes and require high environmental cost. In this study, we successfully prepared $2{\mu}m$ Zn/Cu/Ni multilayers coated on $12{\mu}m$ polyethylene terephthalate (PET) substrate by using dry-wet mixing processes. Their surface electric resistances were evaluated around $0.2{\Omega}$ by using 4 probe measurements. Furthermore, their corrosion resistance also evaluated by natural potential test and compared with other wet, dry and mixing process samples.

• 마이크로전자및패키징학회지
• /
• 제14권2호
• /
• pp.49-57
• /
• 2007

본 연구에서는 Au 와 Sn을 rf-magnetron sputter를 이용하여 다층막(multilayer)과 동시증착(Co-sputter)방법으로 스퍼터링하여 기판위에 AuSn 솔더를 형성하였고, 솔더의 조성제어와 특성 분석을 통해 Sn rich AuSn 솔더의 형성 기술에 대하여 연구하였다. AuSn 솔더를 형성하기 앞서 Au와 Sn에 대하여 단일 금속 증착을 하였다. 이를 토대로 AuSn솔더를 증착하기 위한 실험 조건을 확보하였다. 증착변수로는 기판의 온도, rf 전력과 두께 비를 이용하였다. 다층막의 경우, 고온의 기판에서 솔더 합금의 표면거칠기와 조성이 보다 정확하게 제어되었다. 이에 비해 동시증착 솔더는 기판의 온도에 의한 조성의 변화가 거의 없었으나, rf전력에 의해서 조성이 보다 쉽게 제어할 수 있었다. 여기에 더해, 동시 증착 솔더 박막의 대부분은 증착동안에 금속간 화합물로 변화한 것을 알 수 있었다. 화합물의 종류는 XRD로 분석하였다. 형성된 솔더 박막을 플럭스를 이용하지 않고 리드프레임에 접합하여 접합강도를 측정하였다. 다층형의 경우 Au 10wt%의 조건에서 최대 $33(N/mm^2)$ 전단응력을 나타내었으며, 동시증착형은 Au 5wt%에서 $460(N/mm^2)$ 전단응력을 나타내었다.

• Bulletin of the Korean Chemical Society
• /
• 제35권6호
• /
• pp.1799-1805
• /
• 2014

In this article, we described about the preparation and electrochemical properties of a flexible energy storage system based on a plastic polyethylene terephthalate (PET) substrate. The PET treated with UV/ozone was fabricated with multilayer films composed of 30 polyaniline (PANi)/graphene oxide (GO) bilayers using layer-by-layer assembly of positively charged PANi and negatively charged GO. The conversion of GO to the reduced graphene oxide (RGO) in the multilayer film was achieved using hydroiodic acid vapor at $100^{\circ}C$, whereby PANi structure remained nearly unchanged except a little reduction of doping state. Cyclic voltammetry and charge/discharge curves of 30 PANi/RGO bilayers on PET substrate (shorten to PANi-$RGO_{30}$/PET) exhibited an excellent volumetric capacitance, good cycling stability, and rapid charge/discharge rates despite no use of any metal current collectors. The specific capacitance from charge/discharge curve of the PANi-$RGO_{30}$/PET electrode was found to be $529F/cm^3$ at a current density of $3A/cm^3$, which is one of the best values yet achieved among carbon-based materials including conducting polymers. Furthermore, the intrinsic electrical resistance of the PANi-$RGO_{30}$/PET electrodes varied within 20% range during 200 bending cycles at a fixed bend radius of 2.2 mm, indicating the increase in their flexibility by a factor of 225 compared with the ITO/PET electrode.

• ETRI Journal
• /
• 제33권3호
• /
• pp.335-343
• /
• 2011

The pad pitch of modern radio frequency integrated circuits is in the order of few tens of micrometers. Connecting a large number of high-speed I/Os to the outside world with good signal fidelity at low cost is an extremely challenging task. To cope with this requirement, we need reflection-free transmission lines from an on-chip pad to on-board SMA connectors. Such a transmission line is very hard to design due to the difference in on-chip and on-board feature size and the requirement for extremely large bandwidth. In this paper, we propose the use of narrow tracks close to chip and wide tracks away from the chip. This narrow-to-wide transition in width results in impedance discontinuity. A step change in substrate thickness is utilized to cancel the effect of the width discontinuity, thus achieving a reflection-free microstrip. To verify the concept, several microstrips were designed on multilayer FR4 PCB without any additional manufacturing steps. The TDR measurements reveal that the impedance variation is less than 3 ${\Omega}$ for a 50 ${\Omega}$ microstrip and S11 better than -9 dB for the frequency range 1 GHz to 6 GHz when the width changes from 165 ${\mu}m$ to 940 ${\mu}m$, and substrate thickness changes from 100 ${\mu}m$ to 500 ${\mu}m$.

• 한국진공학회지
• /
• 제2권4호
• /
• pp.439-454
• /
• 1993

The phase sequence of codeposited Co-Si alloy and Co/si multilayer thin film was investigated by differential scanning calormetry(DSC) and X-ray diffraction (XRD) analysis, The phase sequence in codeposition and codeposited amorphous Co-Si alloy thin film were CoSilongrightarrow Co2Si and those in Co/Si multilayer thin film were CoSilongrightarrowCo2Silongrightarrow and CoSilongrightarrowCo2Si longrightarrowCoSilongrightarrowCoSi2 with the atomic concentration ration of Co to Si layer being 2:1 and 1:2 respectively. The observed phase sequence was analyzed by the effectvie heat of formatin . The phase determining factor (PDF) considering structural facotr in addition to the effectvie heat of formation was used to explain the difference in the first crystalline phase between codeposition, codeposited amorphous Co-Si alloy thin film and Co/Si multilayer thin film. The crystallinity of Co-silicide deposited by multitarget bias cosputter deposition (MBCD) wasinvestigated as a funcion of deposition temperature and substrate bias voltage by transmission electron microscopy (TEM) and epitaxial CoSi2 layer was grown at $200^{\circ}C$ . Parameters, Ear, $\alpha$(As), were calculate dto quantitatively explain the low temperature epitaxial grpwth of CoSi2 layer. The phase sequence and crystallinity had a stronger dependence on the substrate bias voltage than on the deposition temperature due to the collisional daxcade mixing, in-situ cleannin g, and increase in the number of nucleation sites by ion bombardment of growing surface.

• 대한금속재료학회지
• /
• 제48권12호
• /
• pp.1116-1122
• /
• 2010

Metal interconnections of multilayer Al/Ni and TiW/seed-Ni/Ni were formed on glass, and the adhesion strength and nanoindentation response of the composite layers were evaluated. The Al/Ni multilayer was formed by an anodic bonding of glass to Al and subsequent electroless plating of Ni, while the TiW/Ni multilayer was fabricated by sputter deposition of TiW and seed-Ni onto glass and electroless plating of Ni. Because of the diffusion of aluminum into glass during the anodic bonding, anodically bonded glass/Al joint exhibited greater interfacial strength than the sputtered glass/TiW one. The Al/Ni on glass also showed excellent resistance against delamination by bending deformation compared to the TiW/seed-Ni/Ni on glass. From the nanoindentation experiment of each metal layer on glass, it was found that the aluminum layer had extremely low hardness and elastic modulus similar to the glass substrate and played a beneficial role in the delamination resistance by lessening stress intensification at the joint. The indentation data of the multilayers also supported superior joint reliability of the Al/Ni to glass compared to that of the TiW/seed-Ni/Ni to glass.

• 한국전기전자재료학회논문지
• /
• 제33권1호
• /
• pp.25-30
• /
• 2020

Oxide (SiO₂)/Metal(Ag)/Oxide(SiO₂, ITO, ZnO) multilayer films were fabricated using a magnetron sputtering technique at room temperature on Si (p-type, 100) and a glass substrate. The electrical and optical properties of the asymmetric multilayer films depended on the thickness of the mid-layer film and the type of oxide in the bottom layer. As the metal layer becomes thicker, the sheet resistance decreases. However, the transmittance decreases when the metal layer exceeds a threshold thickness of approximately 10~12 nm. In addition, the sheet resistance and transmittance change according to the type of oxide in the bottom layer. If the oxide has a large resistivity, the overall sheet resistance increases. In addition, the anti-reflection effect changes according to the refractive index of the oxide material. The optical and electrical properties of multilayer films were investigated using an ultraviolet visible (UV-Vis) spectrophotometer and a 4-point probe, respectively. The optimum structure is SiO₂ (30 nm)/Ag (10 nm)/ZnO (30 nm) multilayer, with the highest FOM value of 7.7×10^-3 Ω^-1.

• 한국전자파학회지:전자파기술
• /
• 제12권3호
• /
• pp.12-24
• /
• 2001

최근에 이동통신 시스템의 다기능/고기능화에 따 라 여러 선진업체에서 RF부품의 모듈화 개발이 추 진되고 있으며, 이에 대응하여 LTCC를 이용한 MCM (Multi-Chip Module)적층기술의 개발이 확대되고 있 다. 이 기술은 세라믹기판 내부에 L, C, R등의 수 동소자를 3차원적으로 구성, 일체화할 수 있기 때문 에 이들 수동소자 뿐 아니라 세라믹 개별 부품으로 이용되고 있는 대역통과 여파기 및 바이어스라인, 임피던스 매칭 회로, 스트립라인등을 하나의 구조물 에 집적화 시킴으로써 제품의 소형화 및 대량생산 이 가능해진다. 본 논문에서는 LTCC를 활용한 고 집적 복합모듈 기술과 동향에 대한 개요 및 개발사례로서 적층 VCO 모듈의 제작에 대해 소개하기로 한다.

• 한국자기학회지
• /
• 제6권5호
• /
• pp.329-333
• /
• 1996

Cu/(NiFe/Ni/NiFe) 금속다층막을 Si(100), Si(111), $4^{\circ}\;tilt-cut\;Si(111)$, slide glass등의 기판 위에 형성하여 자기저항 특성 및 자기이방성을 고찰하였다. $50\;{\AA}$의 Cu를 바닥층으로 사용한 경우 $4^{\circ}\;tilt-cut\;Si(111)$ 기판 위에서 면내 일축 자기이방성을 보였으며 다른 기판 위에서는 자기이방성을 보이지 않았다. 바닥층이 없는 경우나 NiFe, Ni등을 바닥층으로 사용한 경우 $4^{\circ}\;tilt-cut\;Si(111)$ 기판 위에서 자기이방성은 나타나지 않았으며, Cu 바닥층을 증착하기 전 NiFe를 $10\;{\AA}$ 증착하고 형성한 금속다층막의 경우도 면내 자기이방성이 나타나지 않았다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.215-219
• /
• 2007

In this work, the indium zinc oxide (IZO) films had been deposited on the glass substrate coated with the SiO film. Based on a comparative investigation of the IZO monolayer and IZO/SiO multilayer, it is shown that the thickness of SiO film has a great effect on the mechanical properties of the thin films. The AFM images of the IZO thin film included the SiO film were shown smoother surfaces than monolayer. Resistivity was in inverse proportion to Mobility. If it deposited the SiO film on the substrate, the layer of change was generated between two layer(SiO and substrate). The layer of change influenced resistance because of oxygen content was more than the IZO monolayer.