• Title, Summary, Keyword: thick film resistor

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Effect of Screen Printing and Sintering Conditions on Properties of Thick Film Resistor on AlN Substrate (인쇄 및 소결조건이 AlN 기판용 후막저항체의 특성에 미치는 영향)

  • Koo, Bon Keup
    • Journal of the Korean Ceramic Society
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    • v.51 no.4
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    • pp.344-349
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    • 2014
  • $RuO_2$-based high frequency thick-film resistor paste was printed at the speed of 10, 100, 300 mm/sec on the AlN substrate, and then sintered at between 750 and $900^{\circ}C$. The sintered thick films were characterized in terms of printing and sintering conditions. With increasing printing speed, the thickness and roughness of sintered film increased. The resistance of the thick film resistor was reduced by increasing the printing speed from 10 to 100 mm/sec, but did not significantly change at 300 mm/sec speed. With increasing sintering temperature, the surface roughness and thickness of sintered resistor film decreased. The reduction rate was large in case of fast printed resistor. The resistance of the resistor increased up to $800^{\circ}C$ with sintering temperature, but again decreased at the higher sintering temperature.

On the Stannic Oxide Thick Film (산화 주석 후막에 대하여)

  • 박순자
    • Journal of the Korean Ceramic Society
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    • v.12 no.1
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    • pp.5-11
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    • 1975
  • Thick film resistor paste was made utilizing oxide materials such as SnO, SnO+Sb2O3, and SnO+Zn. The oxide materials were mixed respectively with Q-12 glass powder and finally suspended in ethyl cellulose dissolved in ethyl cellosolve. Thick film resistor was made by screen printing the paste on the alumina substrate and firing it at a suitable temperature. Among thick films made from the resistor paste, the thick film containing 85% SnO and fired at $600^{\circ}C$ demonstrated the finest electrical properties showing 10 K ohm in sheet resistance, 110 ppm/$^{\circ}C$ in TCR. In general, TCR of the thick films made from the oxide-mixture paste is good in linearity, therefore it is suggested the oxide-mixture paste is utilized as the negative thermistor.

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Thick Film Resistors with Low Tolerance Using Photosensitive Polymer Resistor Paste (감광성 폴리머 저항 페이스트를 이용한 Low Tolerance 후막 저항체)

  • Kim, Dong-Kook;Park, Seong-Dae;Lee, Kyu-Bok;Kyoung, Jin-Bum
    • Applied Chemistry for Engineering
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    • v.21 no.4
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    • pp.411-416
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    • 2010
  • In this research, we intended to improve the tolerance of thick film resistor using photosensitive polymer resistor paste which was fabricated with alkali-solution developable photosensitive resin and conductive carbon black. At first, we investigated the effect of the selection of carbon black and photosensitive resin on the resistance range and tolerance level of polymer thick film resistor (PTFR). And then, a difference in resistance tolerance was evaluated according to the coating methods of photosensitive resistor paste on test board. In case that the photosensitive resistor paste was coated on whole surface of test board using screen printing, large positional tolerance was obtained because the formation of the thick film with uniform thickness was difficult. On the other hand, when the paste was coated with roller, the resistive thick film with uniform thickness was formed on the whole board area and the result of resistance evaluation showed low tolerance in ${\pm}10%$ range. The tolerance of PTFR could be improved by combination of the precise patterning using photo-process and the coating process for the resistive thick film with uniform thickness.

Fabrication of polymer thick film resistor and study on resistance variation regarding curing temperature (폴리머 후막 저항체의 제작 및 경화 온도에 따른 저항 값 변화에 대한 연구)

  • Yoo, Myong-Jae;Lee, Sang-Myong;Park, Seong-Dae;Kang, Nam-Kee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.212-213
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    • 2006
  • Polymer thick film resistor paste was fabricated using various materials. Inorganic materials of carbon black and graphite were selected as fillers and epoxy resin was selected as organic material. Solvent with high boiling temperature was applied to adjust viscosity. A designed test coupon pattern was used to evaluate fabricated resistors. Aspect ratio of 1 was selected for evaluating resistor values. Electrical properties of fabricated resistors were measured and their values analyzed in relation to paste composition. PTF fabricated using carbon black as fillers achieved resistor value of $530{\Omega}/sq$.

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Thick Film Resistance Paste for Improving Reliability and TCR Properties of Embedded Resistor Board (내장형 저항 기판의 신뢰성과 TCR 개선을 위한 후막 저항 페이스트에 관한 연구)

  • Lee, S.M.;Yoo, M.J.;Park, S.D.;Kang, N.K.;Nam, S.
    • Journal of the Microelectronics and Packaging Society
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    • v.15 no.1
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    • pp.27-31
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    • 2008
  • Due to the increasing need for miniaturization of electronic device, embedded resistor technology using thick film resistance paste to embed resistors currently mounted on the board thus effectively reducing board size, is being extensively researched. In this research, thick film resistor paste having $0.35{\sim}4k{\Omega}/sq$ range of resistivity were fabricated using mixtures of carbon black and epoxy resin. In order to adjust the TCR (temperature coefficient resistivity), TCR modifiers such as Ni-Cr alloy, $SiO_2$ powder were added and were able to improve on TCR value with $100ppm/^{\circ}C$. Finally embedded resistor board using thick film resistance paste were fabricated. Stable resistivity value and reliability results were achieved.

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Analytical Quantification and Effect of Microstructure Development in Thick Film Resistor Processing

  • Lee, Byung Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.4
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    • pp.33-37
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    • 2012
  • Microstructure developments of $RuO_2$ based thick film resistors during firing as a function of glass viscosity were analytically quantified and its effect on the electrical property was investigated. The microstructure development was retarded as the viscosity of glass was increased. It was found that the viscosity range for each stage of microstructure development are as follows ; $7500-10^5Pa{\cdot}s$ for the glass sintering, $2000-7500Pa{\cdot}s$ for the glass island formation, $700-2000Pa{\cdot}s$ for the glass spreading, and $50-700Pa{\cdot}s$ for the infiltration. The sheet resistivity decreased as the viscosity of glass in the resistor film increased due to the higher chance of sintering for the conductive particles with the higher viscosity of the glass.

Thick-Film Strain-gage Ceramic-Pressure Sensor (세라믹 다이어프램을 이용한 후막 스트레인 게이지 압력센서)

  • 이성재;박하용;민남기
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.12
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    • pp.987-993
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    • 2001
  • In this paper, we presents the construction details and output characteristics of a thick film piezoresistive strain gage. The thick film was printed on the ceramic diaphragm back side by screen printing and cured at 850$^{\circ}C$. The strain distribution and deflection on ceramic diaphragm were performed with finite-element method(FEM tool ANSYS-5.3). Various thick film strain gage characteristics were analysed, including nonlinearity, hysteresis, stability and sensitivity of thick film strain gages.

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Fabrication of Photosensitive Polymer Resistor Paste and Formation of Finely-Patterned Thick Film Resistors (감광성 폴리머 저항 페이스트 제조와 미세패턴 후막저항의 형성)

  • Kim, Dong-Kook;Park, Seong-Dae;Yoo, Myong-Jae;Sim, Sung-Hoon;Kyoung, Jin-Bum
    • Applied Chemistry for Engineering
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    • v.20 no.6
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    • pp.622-627
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    • 2009
  • Using an alkali-solution developable photosensitive resin and a carbon black as a conductive filler, photo-patternable pastes for polymer thick film resistor were fabricated and evaluated. A photo solder resist (PSR), which is usually used as protecting layer of printed circuit board (PCB), was used as a photosensitive resin so that ultraviolet exposure and alkali-aqueous solution development of paste were possible. After fabricating the photosensitive polymer resistor paste, the electrical properties of thick film resistors were measured using PCB test boards. Sheet resistance was decreased with increasing amount of carbon black, but the developability was limited in excess loading of carbon black. The sheet resistance was also reduced by re-curing and the change rate was smaller in higher carbon black loading. Moreover, finely patterned meander-type thick film resistors were fabricated using photo-process and large resistance up to several tens of sheet resistance could be obtained in small area by this technique.

Effect of Binder Glass Crystallization on Electrical Properties in $RuO_2$-Thick Film Resistor

  • Sungmin Kwon;Kim, Cheol-Young
    • The Korean Journal of Ceramics
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    • v.2 no.1
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    • pp.33-38
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    • 1996
  • In thick film resistors, the characteristics of the frit and the reaction between glass frit and conductor material play an important role for their electrical properties. In this study, various glass frits in the system of $60RO{\cdot}20SiO_2$ $15B_2O_3{\cdot}5Al_2O_3$(RO=PbO, ZnO, CdO; mole%) were mixed with $RuO_2$ and coated on 96% alumina substrate. Only the glass frit containing PbO was reacted with $RuO_2$in$RuO_{2+}$-thick film resistor and produced the new crystalline phase of $Pb_2Ru_2O_{65}$. Their electrical resistivities strongly depend on the amount of $Pb_2Ru_2O_{65}$ crystalline phase obtained, which varied with firing temperature. The sheet resistivities of these resistors were varied from $10^3\; to\; 10^6\;{\Omega}/{\Box}$ depending on heat treatment, and the absolute value of TCR was decreased as the heat treatment temperature increaed. However, $RuO_2$ did not reacted with the glass frits containing ZnO nor CdO, and the resulting showed very high sheet resistivities.

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Study on the Compositions of Photosensitive Resistor Paste Using Epoxy Acrylate Oligomers and Conductive Carbonblack (에폭시 아크릴레이트 올리고머와 전도성 카본블랙을 이용한 감광성 저항 페이스트 조성 연구)

  • Park, Seong-Dae;Kang, Nam-Kee;Lim, Jin-Kyu;Kim, Dong-Kook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.421-421
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    • 2008
  • Generally, the polymer thick-film resistors for embedded organic or hybrid substrate are patterned by screen printing so that the accuracy of resistor pattern is not good and the tolerance of resistance is too high(${\pm}$20~30%). To reform these demerits, a method using Fodel$^{(R)}$ technology, which is the patterning method using a photosensitive resin to be developable by aqueous alkali-solution as a base polymer for thick-film pastes, was recently incorporated for the patterning of thermosetting thick-film resistor paste. Alkali-solution developable photosensitive resin system has a merit that the precise patterns can be obtained by UV exposure and aqueous development, so the essential point is to get the composition similar to PSR(photo solder resist) used for PCB process. In present research, we made the photopatternable resistor pastes using 8 kinds of epoxy acrylates and a conductive carbonblack (CDX-7055 Ultra), evaluated their developing performance, and then measured the resistance after final curing. To become developable by alkali-solution, epoxy acrylate oligomers with carboxyl group were prepared. Test coupons were fabricated by patterning copper foil on FR-4 CCL board, plating Ni/Au on the patterned copper electrode, applying the resistor paste on the board, exposing the applied paste to UV through Cr mask with resistor patterns, developing the exposed paste with aqueous alkali-solution (1wt% $Na_2CO_3$), drying the patterned paste at $80^{\circ}C$ oven, and then curing it at $200^{\circ}C$ during 1 hour. As a result, some test compositions couldn't be developed according to the kind of oligomer and, in the developed compositions, the measured resistance showed different results depending on the paste compositions though they had the same amount of carbonblack.

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