• 센서학회지
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• 제5권1호
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• pp.23-29
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• 1996

본 연구에서는 스크린 프린팅 기술을 이용한 병렬저항열원을 갖는 후막형 가연성 가스센서를 제조하고, 메탄 가스에 대한 감도특성을 조사하였다. 알루미나 기판의 양면 위에 제조된 병렬형 백금 후막발열체는 후막형백금 저항체의 온도 감지 특성과 표면 특성을 조사하여 백금페이스트 TR7905 제품을 선정하였다. 제조된 백금 후막 발열체는 평균저항같이 $1.8{\Omega}$이고, TCR값은 $3685\;ppm/^{\circ}C$이었다. 제조된 백금 발열체상에 Pt과 Pd이 첨가된 촉매 페이스트를 제조하고 감지부는 Pt과 Pd가 첨가된 촉매를 스크린 프린팅하여 후막을 형성하고 열처리하여 제조하였다. 제조된 후막형 센서는 메탄 가스에 대해 4.3mV/1000ppm의 감도를 보였으며, 소비전력은 2.12W이었다.

• E2M - 전기 전자와 첨단 소재
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• 제9권9호
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• pp.911-917
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• 1996

Platinum thin films were deposited on Si-wafer by DC rnagnetron sputtering for RTD (resistance thermometer devices). We investigated the physical and electrical characteristics of these films under various conditions, the input power, working vacuum, temperature of substrate and also after annealing these films. The deposition rate was increased with increasing the input power but decreased with increasing Ar gas pressure. The resistivity and sheet resistivity were decreased with increasing the temperature of substrate and the annealing time at 1000.deg. C. At substrate temperature of >$300^{\circ}C$, input power of 7 w/cm$^{2}$, working vacuum of 5 mtorr and annealing conditions of 1000.deg. C and 240 min, we obtained 10.65.mu..ohm..cm, resistivity of Pt thin films and 3800-3900 ppm/.deg. C, TCR(temperature coefficient of resistance). These values are close to the bulk value. These results indicate that the Pt thin films deposited by DC magnetron sputtering have potentiality for the development of Pt RTD temperature sensor.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.812-817
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• 2008

A catalytic combustible sensor for LPG/LNG detection was fabricated on $Al_2O_3$ substrate using planar technology. The catalysts of Pd and Pt were added to ${\alpha}$- and ${\gamma}-Al_2O_3$ powders. The mixture of Pt, Pd and $Al_2O_3$ were homogenized by using a three roll mixer. TCR characteristics of Pt heater were optimized with the heat treatment temperature. Sensing properties were investigated as a function of the microstructure of $Al_2O_3$, the gas concentration and the variation of input voltage. ${\alpha}-Al_2O_3$ sintered at 500 $^{\circ}C$ is more suitable as LPG/LNG sensor due to good grain shape and size distribution of about 300 nm than that of ${\gamma}-Al_2O_3$ which is in irregular shape and with a particle size of 5-30 ${\mu}m$. The sensor has shown maximum output voltage of 14 mV for 1000 ppm $C_4H_{10}$ and 3.8 mV for 1000 ppm $CH_4$ at 5.0 V input voltage.

• 전기전자학회논문지
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• 제23권1호
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• pp.159-163
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• 2019

최근 생활수준의 향상으로 외식문화가 발전하고 있고 온라인과 오프라인으로도 냉동식품의 택배수요가 날로 증가하고 있다. 현재 이러한 식품유통의 대부분은 냉동차량에 의해서 이루어지고 있다. 냉동차량에서 가장 중요한 요소 중에 하나는 정확히 온도를 측정하는 것이다. 기존의 상용 온도 기록 시스템은 일반적으로 온도 센서 모듈을 기록계에 직접 연결하는 형태이다. 이러한 기존의 방법은 전선을 사용하여 기록계에 온도 데이터를 전송하기 때문에 케이블의 길이에 따라 저항 오차를 보상해야한다. 본 논문은 케이블 내의 저항으로 인해 발생하는 오차를 극복하기 위해서 디지털 처리와 CAN (Controller Area Network) 통신을 사용하는 것을 제안한다. 또한 온도 측정의 정확도를 높이기 위해서 백금 센서인 PT-1000을 사용한다.

• 센서학회지
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• 제6권3호
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• pp.221-227
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• 1997

Pd/NiCr 게이트 MISFET 센서는 변압기 절연유중 용존수소를 감지하기 위해 제조되었다. 센서의 안정성과 고농도 감지성의 향상을 위해 Pd/NiCr 2중 촉매 금속 게이트가 사용되었다. 수소유입에 의한 게이트 전압의 드리프트를 줄이기 위해, 2개의 FET 게이트 절연층을 실리콘 산화막과 실리콘 질화막의 2중 구조로 하였다. Pd/NiCr 게이트 MISFET 센서의 수소 감응 감도는 Pd/Pt 게이트 MISFET 센서의 감도에 비해 약 0.5배이나, 안정성이 좋고, 1000 ppm까지의 고농도까지 측정할 수 있었다.

• 전기화학회지
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• 제17권1호
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• pp.18-25
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• 2014

A Pt nanoparticle-decorated multiwall carbon nanotube (Pt-MWNT) electrode was prepared on Nafion by a hot-pressing at relatively low temperature. This electrode exhibited an intricate entangled, nanoporous structure as a result of gathering highly anisotropic Pt-MWNTs. Individual Pt nanoparticles were confirmed to have a polycrystalline face-centered cubic structure with an average crystal size of around 3.5 nm. From the cyclic voltammograms for hydrogen redox reactions, the Pt-MWNT electrode was found to have a similar electrochemical behavior to polycrystalline Pt, and a specific electrochemical surface area of $2170cm^2mg^{-1}$. Upon exposure to hydrogen analyte, the Pt-MWNT/Nafion electrode demon-strated a very high sensitivity of $3.60{\mu}A\;ppm^{-1}$ and an excellent linear response over the concentration range of 100-1000 ppm. Moreover, this electrode was also evaluated in terms of response and recovery times, reproducibility, and long-term stability. Obtained results revealed good sensing performance in hydrogen detection.

• 한국표면공학회지
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• 제32권1호
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• pp.3-9
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• 1999

Pt thin film of about 7000$\AA$ thickness was deposited on the alumina substrate using DC Magnetron Sputter and the characteristics of the film for temperature sensor were investigated. When film of about 7000$\AA$ thickness was deposited at working gas pressure of $2.0{\times}10^{-3}$torr, sputtering power of 50W, substrate temperature of $350^{\circ}C$(Ts), sheet resistance(Rs), resistivity($\rho$) and temperature coefficient of resistivity(TCR) of the film were respectively 0.39$\Omega$/$\square$, 27.60$\mu\Omega$-cm and $3350 ppm/^{\circ}C$. When the film was annealed at $1000^{\circ}C$ for 240min in hydrogen ambient, Rs, $\rho$ and TCR were respectively 0.236$\Omega$/$\square$, 15.18$\mu\Omega$-cm and 3716 ppm/$3716 ppm/^{\circ}C$. When working gas of 15sccm oxygen and 100sccm Argon were used, Rs, $\rho$ and TCR were respectively 0.335$\Omega$/$\square$, 22.45$\mu\Omega$-cm and $3427 ppm/^{\circ}C$. When the film was annealed at $1000^{\circ}C$ for 240min, Rs, $\rho$and TCR were respectively 0.224/$\Omega$$\square$, 14$\mu\Omega$-cm and $3760 ppm/^{\circ}C$ and the characteristics of the film were much improved.

• 센서학회지
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• 제9권3호
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• pp.171-176
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• 2000

반응성 스퍼터링과 고주파 마그네트론 스퍼터링으로 각각 증착된 MgO 박막과 그 위에 증착된 백금박막의 열처리 온도 및 시간에 따른 물리적, 전기적 특성을 4침 탐침기, 주사전자현미경 및 X선 회절법을 이용하여 분석하였다. $1000^{\circ}C$, 2시간의 열처리 조건하에서 MgO 박막은 백금박막과 화학적 반응없이 백금박막의 열산화막에 대한 부착특성을 개선시켰으며, 그 위에 증착된 백금박막의 면저항 및 비저항은 각각 $0.1288\;{\Omega}/{\square}$, $12.88\;{\mu}{\Omega}{\cdot}cm$이었다. Lift-off 방법을 이용하여 $SiO_2$/Si기판상에 백금 저항체를 만들었으며, 백금 와이어, 백금 페이스트 그리고 SOG를 이용하여 마이크로 열 센서용 박막형 Pt-RTD를 제작하였다. $25{\sim}400^{\circ}C$의 온도범위에서 $1.0{\mu}m$의 두께를 갖는 제작된 Pt-RTD의 저항온도계수는 벌크 백금에 가까운 $3927ppm/^{\circ}C$로 측정되었다. 측정온도범위내에서 저항값은 선형적인 변화를 보였다.

• Journal of Korean Society for Atmospheric Environment
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• 제20권E2호
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• pp.69-75
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• 2004

In this study, thin film gas sensor based on tin oxide was fabricated to examine its characteristics. Target gas is acetonitrile ($CH_3$CN) which is a blood simulant for the chemical warfare agent. Sensing materials are SnO$_2$ SnO$_2$/Pt, and Sn/Pt with thickness from 1000 to 3000 $\AA$. The sensor consists of a sensing electrode with inter-digit (IDT) type in front side and a heater in rear side. Resistance changes of sensing materials are monitored on real time basis using a data acquisition board with a 12-bit analog to digital converter. Sensitivities are measured at different operating temperatures also with different gas concentrations and film thickness. The high sensitivity is obtained for Sn (3000 $\AA$)/Pt (30 $\AA$) at 30$0^{\circ}C$ for 3 ppm. Response and recovery times were about 40 and 160 s, respectively. Repetition measurements showed very good results with $\pm$3% in full scale range.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.616-623
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• 2007

A dual micro gas sensor array was fabricated using nano sized $SnO_2$ thin films which had good sensitivities to CO and combustible gases, or $H_2S$ gas for air quality sensors in automobile. The already existed air quality sensor detects oxidizing gases and reducing gases, the air quality sensor(AQS), located near the fresh air inlet detected the harmful gases, the fresh air inlet door/ventilation flap was closed to reduce the amount of pollution entering the vehicle cabin through HVAC(heating, ventilating, and air conditioning) system. In this study, to make $SnO_2$ thin film AQS sensor, thin tin metal layer between 1000 and $2000{\AA}$ thick was oxidized between 600 and $800^{\circ}C$ by thermal oxidation. The gas sensing layers such as $SnO_2$, $SnO_2$(pt) and $SnO_2$(+CuO) were patterned by metal shadow mask for simple fabrication process on the silicon substrate. The micro gas sensors with $SnO_2$(+Pt) and $SnO_2$(CuO) showed good selectivity to CO gas among reducing gases and good sensitivity to $H_2S$ that is main component of bad odor, separately.