• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.245-250
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• 2000

고습도 또는 결로시 내수성을 지니는 저항형 습도센서를 제조하기 위하여 vinylbenzyl tributyl phosphonium chloride를 포함하는 4원 공중합체를 합성하여 저습도와 고습도 범위에서 측정이 가능한 습도센서용 감습막을 제작하였다. 1,5-dibrompentane과 4차 염화 가교 반응을 통하여 최종 저항형 습도센서를 제작하였다. 감습막은 알루미나 기판에 한 쌍의 금 paste가 인쇄된 전극을 사용하였으며, 감습막은 다양한 비율의 vinylbenzyl tributyl phosphonium chloride, 2-(dimethlamino)ethyl methacrylate, 2-ethylhexyl acrylate, 그리고 [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride 등을 이용하여 제조하였다. 감습막은 micro-syringe를 이용하여 도포하였으며 건조 oven에서 50℃에서 6시간 동안 가교반응을 진행하였다. 습도센서의 임피던스 특성은 2-(dimethylamino)ethyl methacrylate 또는 [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride의 함량이 증가할수록 감소하였다. vinylbenzyl tributyl phosphonium chloride / 2-(dimethylamino)ethyl methacrylate / 2-ethylhexyl acrylate / [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride의 조성비가 4/4/1/1인 공중합체의 경우 30-90%RH 범위에서 2.64 ㏁ - 3.11 ㏀의 임피던스 특성을 보였으며 우수한 직선성과 낮은 히스테리시스 나타내었다.

• Korean Journal of Materials Research
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• v.5 no.6
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• pp.715-722
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• 1995

Vinylbenzyl triphenyl phosphonium chloride (VTPC) was prepared for the humid membrane. The humidity sensitive memo)lane was composed of copolymers, which have differnet content of VTPC and styrene (VTPC : ST=1 : 0.7 : 3, 5 : 5, 3 : 7). The changes in electrical properties of copolymers with relative humidity were measured. It was found that the impedance decreased with an increase of the content of VTPC in the humid membrane, and the Impedance also decreased with an increase of thickness of humid membrane. The copolymer derived from same equip of VTPC and ST showed 12M$\Omega$-100M$\Omega$ at 70%RH-90%RH, which was required for the current humidity sensor operating at high humidity or dew point. The temperature dependence coefficient at a temperature range 15$^{\circ}C$∼35$^{\circ}C$ was found to be -0.5%RH/$^{\circ}C$ and the hysterisis fabled within the range ${\pm}$2%RH. The response time was found to be 40seconds for varing relative humidity from 75% RH to 95%RH and vice versa.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1898-1899
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• 2005

반도체 집적회로 공정에서 사용되는 폴리이미드 포토레지스트(P12723, Dupont)를 감습막으로 사용하는 마이크로 습도센서 소자를 제작하였다. 마이크로 습도센서는 실리콘 웨이퍼 기판 위에 $SiO_2$ 박막을 건식열산화 공정으로 제작하고, Al 박막을 포토리소그라피 공정으로 패터닝 한 IDT (Interdigital Transducer)를 전극 위에 폴리이미드 포토레지스트를 공정변수를 다양하게 조절하면서 감습막으로 제작하였다. 폴리이미드 감습막은 스핀코팅법으로 제작하였으며, 회전수를 조절하여 두께를 변화시켰다. 완성된 마이크로 습도센서 소자의 상대습도 변화$(10{\sim}90% RH)$에 따른 정전용량 값 변화를 항온항습조 내에서 다양한 온도에서 HP4192A Impedance Analyzer를 사용하여 조사함으로써, 폴리이미드 포토레지스트를 사용하는 마이크로 정전용량형 습도센서의 제작 가능성을 검토하였다. 폴리이미드 정전용량형 마이크로 습도센서는 다양한 인가 전원 주파수에서 기준 센서로 사용된 상용 Vaisala Hygrometer와 유사한 감습특성 및 응답특성을 보였다.

• Industry Promotion Research
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• v.9 no.1
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• pp.31-38
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• 2024

In this study, evaluated the properties of layered silicate-based nanocomposite sensitive film. For the fabrication of nanocomposite materials, we selected organically modified layered silicate materials, specifically Cloisite^® and Bentone^®, which were treated with quaternary ammonium salts. The impedance of the humidity sensors containing organically modified montmorillonite/hectorite clay decreased with increasing relative humidity(RH%). In the case of the Cloisite^® humidity sensor exhibited slightly better impedance linearity and hysteresis compared to the Bentone^® 38 humidity sensor. Additionally the impedance of the sensor with Bentone^® 38 addition was the lowest when compared to the Cloisite^®-modified sensor. Comparing the Cloisite^®-modified sensors individually, we observed different moisture absorption characteristics based on the hydrophilic properties of the organic-treated materials. The response speed of Cloisite^® 93A tended to be slower due to differences in moisture evaporation rates influenced by the hydrophilic organic components. Based on these results, moisture barriers utilizing organically modified layered silicate materials may exhibit slightly lower moisture absorption properties compared to conventional polymer-based moisture barriers. However, their excellent stability, simple processing, and cost-effectiveness make them suitable for humidity sensor applications.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.1
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• pp.49-57
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• 2004

The modified polyionene polyelectrolyte inks were newly prepared and applied to the humidity-sensitive membrane of humidity sensor. The films were fabricated on the alumina substrate with comb-type gold electrode using a ink-jet printing technique. The copolymers of methyl methacrylate, acrylic acid, 2-hydroxyethyl methacrylate and [(2-methacryloyloxy)ethyl]trimethylammonium chloride were also prepared for the humidity-sensing material. which was fabricated by dip-coating method. Electrical measurements under various relative humidity were performed. The humidity-sensitive characteristics of sensors obtained by ink-jet printing technique were compared with that of dip-coating method. Humidity sensors showed a decrease in resistance as an increase of relative humidity and their resistance characteristics are in a close agreement each other.

• Polymer(Korea)
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• v.30 no.3
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• pp.207-209
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• 2006

We fabricated a capacitive-type humidity sensor using poly (p-phenylene ether sulfone: PES) as a humidity sensitive layer. The PES was dissolved in m-cresol $(CH_3C_6H_4OH)$ and spin-coated on ITO-coated glass substrate. Gold was deposited by sputtering as a water-permeable upper electrode. The capacitance of the sensor was inversely proportional to sensing film thicknesses and showed an excellent linearity of less than 1% in the humidity range of 20 to 90%. The sensor haying a $1.4{\mu}m$ sensing layer showed a hysteresis of 1.3% and a good sensitivity of 1.14 at 20 kHz.

• Korean Journal of Materials Research
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• v.10 no.12
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• pp.825-830
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• 2000

The copolymers with various composition of vinylbenzyl chloride (VBC), methyl methacrylate (MMA), and 2-hydroxyethyl methacrylate(HEMA) were synthesized as a humidity sensitive material and quaternized with N, N, N', N'-tetraethylene diamine.. Resistance versus relative humidity decreased with increase in the content of MMA in the copolymer. The introduction of HPMA increased the resistance of the humidity sensor as well as enhanced the adherence to the alumina substrate. In the case of VBC/MMA/HEMA=80/10/10, the hysteresis and temperature dependency coefficient were $\pm$2%RH and -0.46~0.42%RH/$^{\circ}C$. The average resistance at 30%RH, 60%RH and 90%RH were 3.0M$\Omega$ ,200k$\Omega$ and 9k$\Omega$, respectively.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.554-560
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• 1998

Vinylbenzyl triphenyl phosphonium chloride(VTPC)/styrenes=3.7 copolymer was prepared for the moisture-absorptive polyelectrolyte dew sensor containing phosphonium salts. The humid membrane was fabricated on the gold/alumina electrode by dipping. The impedances were $11M{\Omega}$, $980k{\Omega}$, $50k{\Omega}$, and $11k{\Omega}$ at 70%RH, 80%RH, 90%RH and 95%RH, respectively, at $25^{\circ}C$ and the humidity-sensitive charactristic was suitable for the dew sensor. The temperature-dependent coefficient between $15^{\circ}C$ and $35^{\circ}C$ was found to be $-0.25%RH/^{\circ}C$ and the hysteresis falled in the ${\pm}2%RH$ range. The response time was found to be 45 sec for the relative humidity ranging from 70%RH to 98%RH at $25^{\circ}C$. The reliabilities such as temperature cycle, humidity cycle, high temperature and humidity resistance, electrical load stability, stability of long-term storage and water durability were measured and evaluated for the application as a dew sensor.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.598-605
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• 1993

Methacryloxyethyl dimethyl alkyl($C_{1}\sim C_{12}$, benzyl and 2, 2-diethoxy ethyl) ammonium bromide monomers were prepared to investigate the relative humidity characteristics for polymer electrolytes with different chemical structures. They were coated on the alumna substrate printed comblike gold electrode by photopolymerization after micro-syringe injection. As the thickness of rhe humid membrane increased, the impendance decreased, whereas the impedance ~ncreased as the carbon cham of alkyl substituent in the monomer increased. The impendance of the polymeric electrolytes with $C_6\sim C_8$ substituents were varied from 19M$\Omega$ to 5K$\Omega$ for the range of 30-90% Mi. The temperature depedence coefficient in the range of 15-$35^{\circ}C$ was found to be -0.45% $RH/^{\circ}C$and the hysteresis falled within the range of $\pm$2% RH. The response time was 35 second for varying humldity from 33% to 85% RH.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.461-466
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• 1999

The humidity sensor containing ammonium salt was prepared from the copolymer of 2-methacryloxyethyl dimethyl 2-hydroxyethyl ammonium bromide (MDHAB)/MMA/DAEMA = 6/3/1. The humid membrane was fabricated on the gold/alumina electrode by dipping. The impedances were $298k{\Omega},\;11k{\Omega}$, and $2.3k{\Omega}$ at 40%RH, 70%RH and 90%RH, respectively, at $5^{\circ}C$ and the humidity-sensitive characteristics were suitable for low temperature humidity sensor. The temperature-dependent coefficient between $5^{\circ}C$ and $20^{\circ}C$ was found to be $-0.80%RH/^{\circ}C$ and the hysteresis falled in the ${\pm}2%RH$ range. The response time was found to be 38 sec for the relative humidity ranging from 34%RH to 88%RH at $20^{\circ}C$. The reliabilities such as temperature cycle, humidity cycle, high temperature and humidity resistance, electrical load stability, stability of long-term storage and water durability were measured and evaluated for the application as a humidity sensor.