• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.553-555
• /
• 2002

We were fabricated of rf power resisotor on AlN substrates by thick film process. The characteristics of capacitance and microwave are measured by digital LCR meter and Network analyzer(HP8532D). The results are shown that capacitances are slight greater and microwave characteristics are good values.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.1637-1639
• /
• 2000

Resister networks are used widely in many, high frequency applications for attenuators. In this paper we studied the frequency characteristics of attenuator using network analyzer and compared Ni-Cr thin film resistor with thick film resistor attenuator. Also from return loss, insertion loss and VSWR we obtained the maximum available frequency of these attenuators.

• Journal of the Korean Ceramic Society
• /
• v.34 no.3
• /
• pp.233-240
• /
• 1997

The Ru-based thick film resistor(TFR) for sintering at 90$0^{\circ}C$ was synthesized to prepare the LCR net-work. These compositions of pyrochlore could be prepared by decreasing the amount of PbO and increasing alumina and silica contents of glass frit. In this study, the sheet resistances of the TFTs. which sint-ered at 90$0^{\circ}C$ after printing on alumina substrate, the sheet resistances of the TFRs on inductor and capa-citor substrate and the interphase between TFR and substrate were observed. And the changes of the sheet resistance were obtained with the contents of RuO2. In case of the TFR sintered at 90$0^{\circ}C$, the sheet resis-tances on alumina substrates were in the range of 103~106$\Omega$/$\square$, but the sheet resistances of TFR on in-ductor and capacitor substrate were not obtained.

• Korean Journal of Materials Research
• /
• v.2 no.1
• /
• pp.58-64
• /
• 1992

TCR modifying oxides which have negative TCR were added to the $\textrm{RuO}_2$ thick film resistors and how they affect the TCR and resistivity of the systems were investigated. Two types of resistor systems whose ratio of $\textrm{RuO}_2$ to glass were 20/80 and 12/88 were used as standard resistors. It was observed that the modifiers did not always lower the TCR of the resistors and the direction of the TCR change were different from system to system. It was confirmed, however, that the feasibility of optimization of TCR of the resistors. When more than two TCR modifiers were added simultaneously there was no interaction between them. The resultant TCR of the resistor wart just sum of the effects from individual modifier. It was found to be desirable that the amount of addition of the TCR modifiers should be less than 2 to 3 percent.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.50-50
• /
• 2007

We report the effect of the film thickness on electrical properties of Ti(N) film resistors. The applications of titanium nitride thin film resistor in $\Pi$-type attenuators are also characterized. As film thickness decreases from 100 to 30 nm, temperature coefficient of resistance significantly decreases from -60 to -148 ppm/K, while sheet resistance increases from 37 to $270\;{\Omega}/{\square}$. The characterizations of 20dB-attenuators using thin film resistors are improved in comparison with those using thick film resistors. The $\Pi$-type attenuators using Ti(N) thin film resistors exhibit a attenuation of -19.94 dB and voltage standing wave ratio of 1.16 at a frequency of 2.7 GHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.311-312
• /
• 2008

$RuO_2$ 계열의 후막재료를 사용한 저항의 신뢰성시험을 실시하고 주요 고장 메커니즘을 확인하였다. 사용된 소자의 기판은 AlN 세라믹 기판이며, 후막재료로 $RuO_2$ paste를 프린팅하고 소결시킨 구조의 고주파용 저항(RF Termination)이다. 주요 고장 메커니즘은 후막(Thick Film)의 특성변화, 기판의 특성변화, 전극-후막 간의 접촉특성변화, Trimming 부위의 열화, 열팽창계수 차이에 의한 기계적 파손 등으로 알려져 있으며, 본 실험에서는 고장모드 분석을 위해 과부하시험, 고온동작시험 등을 포함한 신뢰성 환경시험과 수명시험을 실시하였다. 각 시험 결과 수명시험 후 전극-후막 간의 접합부 파괴가 관찰되었고, 열충격 시험 결과 후막의 crack이 관찰되었다.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.3
• /
• pp.79-86
• /
• 1992

The cause of excess current noise which appears some times in RuO$_2$ thick film chip resistors and the process to reduce such noise are investigated. We observed that too large thermal expansion coefficients of resistor paste and electrode metal paste can induce the mechanical stress and microcracks in the contact region of the two sintered materials. Such microcracks result in the reduction of conduction paths in the sintered electrode and this provokes the increase of the resistance value and the current noise. Such excessive current noise induced by microcracks could be reduced or even eliminated by using an enlarged overcoat patterns in the plating process or by adding an additional annealing process before plating.

• Journal of Sensor Science and Technology
• /
• v.16 no.6
• /
• pp.407-412
• /
• 2007

For $VO_{2}$ sensors applicable to temperature measurement by using the nature of semiconductor to metal transition, the crystallinity, microstructure, and temperature vs. resistance characteristics were investigated systematically as a function of the annealing condition. The starting materials, vanadium pentoxide ($V_{2}O_{5}$) powders, were mixed with vehicle to form paste. This paste was screen-printed on $Al_{2}O_{3}$ substrates and then $VO_{2}$ thick films were heat-treated at $450^{\circ}C$ to $600^{\circ}C$, respectively, for 1 hr in $N_{2}$ gas atmosphere for the reduction. As results of the temperature vs. resistance property measurements, the electrical resistance of the $V_{2}O_{5}$ sensor in phase transition range was decreased by $10^{3.9}$ order. The presented critical temperature sensor could be used in fire-protection and control systems.

• Proceedings of the KIEE Conference
• /
• 1990.07a
• /
• pp.215-220
• /
• 1990

A.C. impedance properties of $RuO_2$ based thick film resistors which having different resistivity value (DuPont 1721 : $100{\Omega}$/ sq., 1741 : $10K{\Omega}$/sq.) were investigated using by impedance analyzer. In case of lower resistivity 1721 system, the complex impedance was composed nearly R component for all speciman sintered at above $600^{\circ}C$, and the frequency dependancy on impedance was not affected very much up to 5MHz and again gradually increase with increasing the frequency. In case of higher resistivity 1741 resistor system, impedance properties were very depandant on sintering temperature. When sintering temperature was $600^{\circ}C$, the complex impedance plot shows a vertical line, which correspond to lone capacitance equivalant circuit, and the impedance linearly decreased with increasing frequency. In case of speciman sintered at $700-900^{\circ}C$, the complex impedance plot shows semi-circular are correspond to a lumped RC combination, and the impedance shows constant value to 5MHz, again decreased with increasing frequency. But the complex impedance behavior of speciman sintered at $1000^{\circ}C$ was shows the equivalent circuit correspont to parallel combined LCR component, and the impedance was not varied with frequency.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.190-190
• /
• 2003

여러원소 (Sb, F 등)를 도핑한 SnO$_2$ 투명전도막은 여러 가지 훌륭한 특성으로 Solar cell, heat mirrors, gas sensors, liquid crystal displays, thick film resistor 등과 같이 넓은 범위에서 응용되고 있다. 본 연구에서는 Sb 도핑된 Tin Oxide films이 Sol-gel dip coating법에 의해 준비되었다. SnO$_2$:Sb 용액은 SnC1$_2$ 와 SbC1$_3$ Power를 알코올에 용해하여 Ethylene glycol 와 Citric acid를 첨가하여 합성하였다. 막의 상형성은 XRD와 SEM(Scanning electron microscope)에 의해서 분석되었으며, 특성분석은 투과율(UV/VIS Spectrophotometer)과 표면전기저항(four point probe)으로 분석되었다. SiO$_2$ barrier이 SnO$_2$:Sb 막의 특성에 미치는 영향을 확인하기 위하여 XPS(X-ray photoelectron spectroscopy) 분석이 적용되었다.