• The Journal of the Acoustical Society of Korea
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• v.27 no.6
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• pp.263-270
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• 2008

The performance of an ultrasonic array sensor is determined by the properties of constituent materials and the effects of many structural parameters. In this study, with the finite element method, variation of the performances of an ultrasonic array sensor was analyzed in relation to its structural variables. Based on the analysis result, the structure of the ultrasonic array sensor was optimized to provide the highest sensitivity while satisfying such requirements as fractional bandwidth, center frequency and -20 dB pulse length. The optimization was carried out with the SQP-PD method for a target function composed of the ultrasonic array sensor performance. The optimized ultrasonic array sensor satisfied all the required specifications to be applicable to medical imaging diagnosis. The design technology in this paper can be utilized for other ultrasonic array sensors of a similar structure.

• Korean Journal of Optics and Photonics
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• v.30 no.2
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• pp.67-73
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• 2019

In this paper, we investigated the sensing ability of an extraordinary optical transmission sensor, which is based on the diverse configurations of highly ordered structures. The diverse nanostructures of subwavelength hole array were designed to have different periods and lattice configurations of the array. To verify the sensing ability of the sensor, we measured the transmittance spectra of samples (n = 1.333, 1.363) for diverse configurations of substrates. The measured transmittance spectra of diverse materials with different refractive indices show that the sensitivity increased as the period of the structures increased. Also, improved sensing performance of the sensor was achieved for the square array, compared to the hexagonal array.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.74-78
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• 2002

MEMS공정을 이용하여 폴리실리콘의 piezoresistivity를 이용한 스트레인 센서어레이를 제작하였고, 이 센서 어레이를 flexible substrate에 패키징하는 공정을 개발하였다. 실리콘 웨이퍼에 표면 가공(surface micromachining)된 센서는 폴리이미드 코팅, release-etch 방법을 통해 웨이퍼로부터 분리되어 폴리이미드를 기판으로 하는 flexible sensor array module을 완성할 수 있었다. 공정은 희생층과 절연층을 증착하고 폴리실리콘 0.5 $\mu\textrm{m}$을 증착, 도핑 및 패터닝하여 센서 어레이를 구성하였다. 이 센서어레이를 flexible substrate에 패키징 하기 위해서 폴리이미드를 코팅하여 15 $\mu\textrm{m}$의 막을 구성하였고, 100% $O_2$RIE를 이용한 선택적 식각 방법으로 via hole을 구성하였다. 이후 전기도금을 통해 회로를 구성하여 1단계 패키징(die to chip carrier)과 2단계 패키징(chip to substrate)을 웨이퍼 레벨에서 완성하였다. 희생층을 제거함으로서 웨이퍼로부터 센서어레이 모듈을 분리하였다. 제작되어진 센서 모듈은 임의의 곡면에 실장이 가능하도록 충분한 flexibility를 얻을 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.12
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• pp.17-23
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• 2003

A sensor array (3${\times}$5$\textrm{mm}^2$ in diaphragm dimension) of 12 sensing clements with different operating temperatures was optimized with respect to thermal operation. This sensor array with single heater on a glass diaphragm over back-etched silicon bulk realizes a novel concept of a sensor array: an array of sensor clements operated at different temperatures can yield more information than single measurement. The proposed micro sensor array could provide well-integrated array structure because it had only single heater at the center of the diaphragm and used the various sensing properties of two kinds of metal oxide layers with various operating temperatures.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.189-192
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• 1998

본 논문에서는 희소어레이 구조를 응용한 선형제약형 적응어레이 처리기를 제안하였다. 다경로 환경하에서 간섭신호의 제거에 효과적인 공간유화방법을 사용하여 제안된 어레이 처리기의 성능을 분석평가하였다. 선형어레이와 최적화된 센서간격으로 이루어진 선형어레이와 정상어레이 간의 성능을 비교하였다. 실험결과 최적화된 희소어레이를 이용한 선형제약형 적응어레이의 성능이 정상어레이의 성능에 버금가는 것으로 나타났다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.86-89
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• 2007

실리콘을 사용한 X선 감지 용 센서 어레이 제작에 대해 연구하였다. 단일 센서 소자에서는 필수적인 guard ring구조가 어레이에서는 적절히 설계되지 못할 경우 누설전류 증가를 초래하는 것으로 나타났다. 즉, 누설전류는 공??????층 두께와 능동영역 및 guard ring 구조 간 거리에 매우 민감한 것으로 조사되었다. 또한 다결정 실리콘과 n형 도핑 소스로 인을 활용하는 조합이 결함 gettering을 위한 효율적인 방법임이 입증되었으나 고온 공정과정에 보호되지 않은 채 노출되는 경우에는 효과적이지 못한 것으로 관측되었다. 본 연구에서는 이러한 결과들을 고려하여 어레이를 제작하였으며 우수한 특성을 관찰할 수 있었다.

• The Journal of the Acoustical Society of Korea
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• v.20 no.4
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• pp.12-16
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• 2001

To analyze the performance of array shape estimation techniques using auxiliary sensors, the appropriate number and the positions of auxiliary sensors are investigated. Also, a post-processing technique based on spline interpolation is proposed to improve the performance of array shape estimation. The simulation results showed that when auxiliary sensors are arranged uniformly, the performance of shape estimation is better than other arrangements of auxiliary sensors. Also, the proposed post-processing technique improved the performance of the existing shape estimation method, such as Kalman filter method.

• Journal of Sensor Science and Technology
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• v.10 no.2
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• pp.108-117
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• 2001

A sensor array with 10 discrete sensors integrated on a substrate w3s developed for discriminating the kinds and quantities of inflammable gases, like butane, propane, methane, LPG, carbon monoxide. The sensor array consisted of 10 metal oxide semiconductor gas sensors using the nano-sized $SnO_2$ as base material and had differentiated sensitivity patterns to specific gas. The sensor array was designed with uniform thermal distribution and had also high sensitivity and good reproductivity to low gas concentration through nano-sized sensing materials with different additives. By using the sensing patterns of the sensor array at $400^{\circ}C$, we could reliably discriminate the kinds and quantities of the tested inflammable gases under the lower explosion limit through the principal component analysis(PCA).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.11
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• pp.9-17
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• 2000

A sensor array with 10 discrete sensors integrated on a substrate was developed for discriminating the kinds and quantities of explosive gases. The sensor array consisted of 10 oxide semiconductor gas sensors with $SnO_2$ as base material and had broad sensitivity to specific gas. The sensor array was designed with uniform thermal distribution and had also high sensitivity and reproductivity to low gas concentration through nano-sized sensing materials with different additives. By using the sensitivity signal of the sensor array at $400^{\circ}C$, we could reliably discriminate the kinds and quantities of explosive gases like butane, propane and methane under the lower explosion limit through the principal component analysis (PCA) method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.1
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• pp.11-19
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• 2003

A micro sensor array with 4 discrete sensors integrated on a microhotplate was developed for identifying the kinds and quantities of explosive gases. The sensor array consisited of four tin oxide-based thin films with the high and broad sensitivity to the tested explosive gases and uniform thermal distribution on the plate. The microhotplate, using silicon substrate with N/O/N membrane, dangling in air by Al bonding wires, and controlling the thickness by chemical mechanical process (CMP), has been designed and fabricated. By employing the sensitivity signal of the sensor array at 40$0^{\circ}C$, we could reliably classily the kinds and quantities of the explosive gases like butan, propane, LPG, and carbon monoxide within the range of threshold limit values (TLVs), employing principal component analysis (PCA).