• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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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 $530{\Omega}/sq$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.98-99
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• 2007

This study has successfully demonstrated the direct fabrication of polymer resistors using ink-jet printing technology as an alternative patterning to traditional photolithography. The polymer resistors were fabricated just by two layer processes using a ink-jet printer (DMP-2800, Fujifilm Dimatix). First, resistive materials was patterned by a ink-jet printing with the desired width and length. Next, resistor fabrication was completed by printing metal contact pads on the both sides of the polymer resistor. We used poly (3,4-ethylene dioxythiophene) poly(styrenesulfonate)(PEDOT:PSS) for the resistor material and a nano-sized silver colloid for the metal contact pads. We characterized the electrical properties of PEDOT:PSS by measuring sheet resistance and specific resistance on a glass substrate. From analysis of the measured resistances, the electrical resistances of the polymer resistors linearly increased as a function of printed width and length of resistors. The accuracy of the fabricated polymer resistor showed about $0.6{\sim}2.5%$ error for the same dimensions.

• 공업화학
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• 제21권4호
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• pp.411-416
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• 2010

본 연구에서는 알칼리 현상형 감광성 수지재료와 전도성 카본블랙을 이용하여 만들어진 감광성 폴리머 저항 페이스트를 이용하여 후막저항체의 허용편차(tolerance)를 개선하고자 하였다. 먼저 카본블랙과 감광성 수지의 선택이 폴리머 후막저항(polymer thick film resistor, PTFR)의 저항값의 범위와 허용편차의 수준에 미치는 영향을 조사하였다. 이후 테스트 기판상에 감광성 저항 페이스트를 도포하는 방법에 따른 저항값 허용편차의 차이를 평가하였다. 감광성 저항 페이스트를 스크린 인쇄를 이용하여 테스트 기판의 전면에 도포한 경우에는 테스트 기판상에서 균일한 두께의 후막을 형성하기 어렵기 때문에 위치에 따른 저항값의 허용편차가 크게 나타났다. 반면, 롤러를 이용하여 페이스트를 도포하였을 때, 전체 기판 면적에 균일한 두께의 저항체 후막을 형성할 수 있었으며, 저항값 평가 결과 ${\pm}10%$ 이내의 낮은 허용편차를 나타내었다. 포토공정을 이용한 정밀한 패터닝 공정과 롤러를 이용한 균일한 두께의 저항막 도포 공정을 결합함으로써 후막저항의 허용편차를 개선할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.757-758
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• 2007

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.311-312
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• 2005

Applying a designed test coupon pattern for fabricating resistors various resistors were formed using PTF(polymer thick film) pastes. Aspect ratio from 0.25 to 4 were selected for fabricating resistors. Formed resistors were cured at $170^{\circ}C$ and $240^{\circ}C$. Electrical properties of fabricated resistors were measured and their values analyzed in relation to cure temperature and formed geometry via printing. Also effects of substrates used for fabricating resistors were observed.

• 공업화학
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• 제20권6호
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• pp.622-627
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• 2009

알칼리 수용액에 현상이 가능한 감광성 수지재료와 전도성 카본블랙 필러를 이용하여 포토 패터닝이 가능한 폴리머 후막 저항 페이스트를 제조하고 평가하였다. 감광성 수지로는 인쇄회로기판의 보호층으로 주로 사용되는 photo solder resist(PSR)를 사용하여 자외선에 의한 노광 및 알칼리 수용액에의 현상이 가능하게 하였다. 감광성 폴리머 저항 페이스트를 제작한 후, PCB 테스트 보드를 이용하여 후막저항체의 전기적 특성을 평가하였다. 카본블랙의 첨가량에 따라 시트저항은 감소하였으나, 과량 첨가시에는 현상성에 한계를 나타내었다. 재경화에 따라서 시트저항이 감소하였으며, 카본블랙의 첨가량이 많을수록 그 변화율은 작게 나타났다. 포토공정을 적용하여, 미세 패터닝된 meander형 후막저항체를 제조할 수 있었고, 이 방법을 통하여 적은 면적에도 시트저항의 수십 배에 달하는 큰 저항값을 구현할 수 있었다.

• 대한기계학회논문집A
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• 제30권4호
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• pp.364-372
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• 2006

In this paper, we present a finger tip tactile sensor which can detect contact normal force as well as slip. The sensor is made up of two different materials, such as polyvinylidene fluoride (PVDF) known as piezoelectric polymer, and pressure variable resistor ink. In order to detect slip on the surface of the object, two PVDF strips are arranged along the normal direction in the robot finger tip and the thumb tip. The surface electrode of the PVDF strip is fabricated using silk-screening technique with silver paste. Also a thin flexible force sensor is fabricated in the form of a matrix using pressure variable resistor ink in order to sense the static force. The developed tactile sensor is physically flexible and it can be deformed three-dimensionally to any shape so that it can be placed on anywhere on the curved surface. In addition, a tactile sensing system is developed, which includes miniaturized charge amplifier to amplify the small signal from the sensor, and the fast signal processing unit. The sensor system is evaluated experimentally and its effectiveness is validated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.332-335
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• 2000

We fabricated organic electroluminescent (EL) devices with single layer of poly(3-dodeoylthiophene) (P3DoDT) hlended with different amounts of poly(N-vinylcarbazole) (PVK) as a emitting layer. The molar ratio between P3DoDT and PVK changed with 1:0, 2:1 and 1:1. To improve the external quantum efficiency of EL devices, we applied insulating layer, LiF layer, between polymer emitting layer and Al electrode. All of the devices emit orange-red light and it's can be explained that the energy transfer occurs from PVK to P3DoDT. In the voltage-current and voltage-brightness characteristics of devices applied LiF layer, current and brightness increased with increasing applied voltage. The brightness of the device have a molar ratio 1:1 with LiF layer was about 10 times larger than that of the device without PVK at 6V. Electrical impedance properties of ITO/emitting layer/LiF/Al devices were investigated. In the Cole-Cole plots of impedance data, one semicircle was observed. Therefore, the equivalent circuit for the devices can be designed as a single parallel resistor and capacitor network with series resistor.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.334-337
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• 2005

We have found that the hysteretic behavior of a polymer stabilized ferroelectric liquid crystal system coincides with Blinov et. al's model qualitatively. The hysteresis inversion frequency could be promoted up to 7000 Hz by connecting external capacitor and resistor in serial. In addition, the influence of temperature and the amplitude of the applied field on hysteresis-free switching of the cell could be minimized.