마이크로 블라스터를 이용한 실리콘 웨이퍼의 2단계 표면 텍스쳐링

조찬섭,정상훈,Cho, Chan-Seob,Jung, Sang-Hoon 한국반도체디스플레이기술학회 2010 반도체디스플레이기술학회지 Vol.9 No.3

Recently, the important issues of solar cell are low cost and high efficiency. Making low cost and high efficiency solar cell, there are many effects to development of inexpensive wafer, simplify process and improve optical, electrical properties. In this the study, the 2 step texturing method using micro blaster was developed to decrease reflection of incident lights. Air bridge electrode structure is suggested to expand the effective surface area and decrease the series resistance of finger electrode. The effects of 1 step texturing and 2 step texturing by micro blaster are compared. Reflectance of 1 step and 2 step texturing are measured 28.7% and 25.5%, respectively. The reflectance of 2 step texturing sample is lower about 3.2% than 1 step textured sample.

HF 양극반응을 이용한 단결정 실리콘 미세구조의 제조

조찬섭,심준환,이석수,이종현,Cho, Chan-Seob,Sim, Jun-Hwan,Lee, Seok-Soo,Lee, Jong-Hyun 한국센서학회 1992 센서학회지 Vol.29 No.3

실리콘 기판을 HF용액 내에서 양극반응을 시켜 electropolishing법 또는 PSL 형성법으로 센서와 actuator에 유용한 다양한 모양의 실리콘 미세 기계구조를 제조하였다. 미세구조는 시편의 결정면에 관계없이 형성되었으며, 저농도 도핑된 단결정 실리콘이다. $n^{+}/n$ 실리콘 시편을 HF용액(20-48%)내에서 양극반응시켜 $n^{+}$ 영역에 선택적으로 PSL을 형성하였으며, HF농도, 반응전압 및 반응시간에 따른 PSL 형성의 특성을 조사였다. $n^{+}$ 영역에만 PSL이 형성되었으며 PSL의 다공도는 HF 농도 증가에 따라 감소하였으며, 반응전압에는 무관하였다. $n/n^{+}/n$형 구조를 이용하여 미세구조를 제조한 경우, 식각된 실리콘 표면이 균일하고 cusp가 제거되었으며, 미세구조의 두께는 전 영역을 통하여 n-epi.층의 두께로 일정하였다. HF용액(5 wt%)에서의 양극반응과 planar기술을 이용하여 가속도센서를 제조하여 기존의 IC 공정기술과 함께 사용이 가능함을 확인하였다. 또 모터의 회전자, 기어 등의 미세 기계구조를 PSL 형성법으로 제조하고 SEM 사진으로 조사하였다. Some silicon micromechanical structures useful in sensors and actuators have been fabricated by electropolishing or porous silicon formation technique by anodic reaction in HF solution. The microstructures were lightly doped single crystal silicon and the formation was isotropic independent of crystal directions. Porous silicon layer(PSL) was formed selectively in $n^{+}$ region of $n^{+}/n$ silicon structure by anodic reaction in concentrated HF(20-48%) solution. Characteristics of the formed PSL were investigated along with change of the reaction voltage, HF concentration and the reaction time. PSL was formed only in $n^{+}$ region. The porosity of the PSL was decreased with the increase of HF concentration and independent of reaction voltage. For the case of $n/n^{+}/n$ structures, the etched surface of silicon was fairly smooth and a cusp was not found. The thickness of the microstructures was the same as that of the epitaxial n-Si layer and good uniformity. We have fabricated acceleration sensors by anodic reaction in HF solution(5 wt%) and planar technology. The process was compatible with conventional It fabrication technique. Various micromechanical structures, such as rotors of motor, gears and linear actuator, were also fabricated by the technique and examined by SEM photographs.

무연솔더를 이용한 실리콘 압력센서의 플립칩 패키지

조찬섭(Chan-Seob Cho) 한국산업융합학회 2009 한국산업융합학회 논문집 Vol.12 No.4

A packaging technology based on flip-chip bonding and Pb-free solder for silicon pressure sensors on printed circuit board (PCB) is presented. First, the bump formation process was conducted by Pb-free solder. Ag-Sn-Cu solder and the pressed-screen printing method were used to fabricate solder bumps. The fabricated solder bumps had 189-223 ㎛ width, 120-160 ㎛ thickness, and 5.4-6.9 standard deviation. Also, shear tests was conducted to measure the bump shear strength by a Dage 2400 PC shear tester; the average shear strength was 74 g at 0.125 ㎜/s of test speed and 5 ㎛ shear height. Then, silicon pressure sensor packaging was implemented using the Pb-free solder and bump formation process. The characteristics of the pressure sensor were analogous to the results obtained when the pressure sensor dice are assembled and packaged using the standard wire-bonding technique.

MEMS 공정에 적용하기 위한 마이크로 블라스터 식각 특성

조찬섭 ( Chan Seob Cho ),배익순 ( Ig Soon Bae ),이종현 ( Jong Hyun Lee ) 한국센서학회 2011 센서학회지 Vol.20 No.3

Abrasive blaster is similar to sand blaster, and effectively removes hard and brittle materials. Exiting abrasive blaster has applied to rough working such as deburring and rough finishing. As the need for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro abrasive blaster was developed, and became the inevitable technique to micromachining. This paper describes the performance of the micro blaster in MEMS process of glass and succeed in domestically producing complete micro blaster. Diameter of hole and width of line in this etching is 100 ㎛~1000 ㎛. Experimental results showed good performance in micro channel and hole in glass wafer. Therefore, this micro blaster could be effectively applied to the micro machining of semiconductor, micro PCR chip.

열박막 풍속계의 제작 및 특성

김형표,조찬섭,Kim, Hyung-Pyo,Cho, Chan-Seob 한국센서학회 2000 센서학회지 Vol.9 No.3

본 논문에서는 실내의 공기 흐름을 간단하게 측정할 수 있는 정온도형 디지털 열박막 풍속계를 개발하였다. 센서의 출력전압은 풍속에 대해서 4제곱근에 비례하므로 마이크로프로세서와 A/D 컨버터를 사용하여 선형화 하였다. 제작한 풍속계의 출력 풍속값은 기준 풍속계와 비교한 결과 오차는 ${\pm}2%$이내였다. 제작한 풍속계를 풍속이 10m/sec이고 공기 온도가 $23^{\circ}C{\sim}60^{\circ}C$ 범위에서 온도 실험한 결과에서 온도에 대한 오차는 약 ${\pm}1%$ 이었다. The paper presents the constant temperature digital hot-film anemometer that measures easily a wind velocity at the indoor. The output is linearized using microprocessor and analog-to-digital converter, because the fourth root of the wind velocity is the output voltage of the sensor. The comparison result between fabricated and reference anemometer is less than ${\pm}2%$. In the range of air temperature of $23^{\circ}C{\sim}60^{\circ}C$, the error is about ${\pm}1%$ in wind velocity 10m/sec.

선택적인 다공질 실리콘 에칭법을 이용한 압저항형 실리콘가속도 센서의 제조

심준환,김동기,조찬섭,태흥식,함성호,이종현 ( Jun Hwan Sim,Dong Ki Kim,Chan Seob Cho,Heung Sik Tae,Sung Ho Hahm,Jong Hyun Lee ) 한국센서학회 1996 센서학회지 Vol.5 No.5

A piezoresistive silicon acceleration sensor with 8 beams, utilized by an unique silicon micromachining technique using porous silicon etching method which was fabricated on the selectively diffused (111)-oriented n/n/n silicon subtrates. The width, length, and thickness of the beam was 100 ㎛, 500 ㎛, and 7 ㎛, respectively, and the diameter of the mass paddle (the region suspended by the eight beams) was 1.4 mm. The seismic mass on the mass paddle was formed about 2 mg so as to measure accelerations of the range of 50g for automotive applications. For the formation of the mass, the solder mass was loaded on the mass paddle by dispensing Pb/Sn/Ag solder paste. After the solder paste is deposited, Heat treatment was carried out on the 3-zone reflow equipment. The decay time of the output signal to impulse excitation of the fabricated sensor was observed for approximately 30 ms. The sensitivity measured through summing circuit was 2.9 mV/g and the nonlinearity of the sensor was less than 2% of the full scale output. The output deviation of each bridge was ±4%. The cross-axis sensitivity was within 4% and the resonant frequency was found to be 2.15 kHz from the FEM simulation results.

열박막 품속계의 제작 및 특성

김형표(Hyung Pyo Kim),조찬섭(Chan Seob Cho) 한국센서학회 2000 센서학회지 Vol.9 No.3

N/A The paper presents the constant temperature digital hot-film anemometer that measures easily a wind velocity at the indoor. The output is linearized using microprocessor and analog-to-digital converter, because the fourth root of the wind velocity is the output voltage of the sensor. The comparison result between fabricated and reference anemometer is less than ±2%. In the range of air temperature of 23℃ ∼ 60℃, the error is about ±1% in wind velocity 10m/sec.

Force Sensing Resistor Sensor의 제작과 평가

이기학(Ki-Hak Lee),김봉환(Bonghwan Kim),조찬섭(Chan-Seob Cho),이병렬(Byeugleul Lee),이동인(Dong-In Lee) 대한전자공학회 2021 대한전자공학회 학술대회 Vol.2021 No.6

연요철(Anti-Glare) 구조의 표면 유리 기판을 가지는 고효율 태양전지 모듈

공대영,김동현,윤성호,배영호,류인식,조찬섭,이종현,Kong, Dae-Young,Kim, Dong-Hyun,Yun, Sung-Ho,Bae, Young-Ho,Yu, In-Sik,Cho, Chan-Seob,Lee, Jong-Hyun 한국진공학회 2011 Applied Science and Convergence Technology Vol.20 No.3

태양전지 모듈은 back sheet, 후면 충진재, 태양전지 cell, 전면 충진재, 전면 보호유리의 구성으로 되어 있다. Back sheet는 유리 또는 금속을 사용하는데 사용 재료에 따라 각각 유리봉입방식, 슈퍼스트레이트방식으로 구분된다. 태양전지를 보호하기 위한 충진재는 빛의 투과율 저하가 적은 poly vinyl butylo나 내습성이 뛰어난 ethylene vinyl acetate 등이 주로 이용된다. 유리봉입방식과 슈퍼스트레이트 방식의 공통점은 모듈 전면에 투과율과 내 충격 강도가 좋은 강화 유리를 사용하는 것이다. 하지만 현재 모듈의 전면 유리는 평탄한 표면 때문에 태양고도가 낮을 때 상대적으로 반사율이 높은 단점을 가지고 있다. 이러한 문제점을 해결하기 위한 방안으로 표면 유리에 요철(anti-glare) 구조를 형성하면 평면(bare) 구조의 표면에서 반사되는 태양광이 일부 태양전지 내부로 재입사가 일어나게 되어 표면 반사율이 낮아지게 되고, 이로 인하여 태양전지의 효율이 증가하게 된다. 특히 이러한 효과는 태양고도가 낮아졌을 때 요철(anti-glare) 구조에 의한 반사율의 감소가 증가하기 때문에 평면 구조보다 요철(anti-glare) 구조의 태양전지 모듈의 효율이 향상될 것이다. 본 논문에서는 요철(anti-glare) 구조의 유리와 평면 구조의 유리에서 태양고도의 고도 변화에 따른 반사와 투과 특성을 확인하기 위하여 입사광의 각도에 대한 반사율과 투과율을 측정하여 비교 분석하였다. 그리고 태양전지 cell 위에 요철(anti-glare) 구조의 유리와 평명 구조의 유리를 각각 위치 시킨 후 태양전지 cell의 효율 변화를 확인하였다. 태양전지 cell의 표면 구조에 따라 요철 구조의 유리 기판의 특성을 비교하기 위하여 태양전지 cell의 표면을 이방성 식각 용액을 이용하여 역피라미드 구조의 텍스쳐링 태양전지 cell과 평면 구조의 태양전지 cell을 각각 사용하여 비교하였다. Currently, solar module is using the two methods such as a glass-filled method or a super-straight method. The common point of these methods is to use glass structure on the front of solar module. However, the reflectance of the solar module is high depending on the height of the incident sunlight due to the flat surface of the module front glass. Purposed to solve these problems, AG (anti-glare) structures were formed on the glass surface. Next is fabrication methods of AG structure. First, uneven structure made by micro blaster equipment was dipped in Hydro-fluidic acid (HF) acid. HF acid process was carried out to remove particles and to make high transmittance. The reflectance and transmittance of the anti-glare glass was compared to those of the bare glass. The reflectance of anti-glare glass decreased approximately 1% compared with bare glass. The transmittance of anti-glare glass was similar to bare glass. According to the sample angle, the difference of the reflectance between bare glass and the anti-glare glass was about 19%. Isc and efficiency value of anti-glare glass on bare solar cell appeared about 3.01 mA and 0.228% difference compared with bare glass. Anti-glare glass on textured solar cell appeared about 9.46 mA and 0.741% difference compared with bare glass. As a result, the role of anti-glare in the substrate is to reduces the loss of sunlight reflected from the surface. In this study, therefore, AG structure on the solar cell was used to improve the efficiency of solar cell.

PTFE 코팅을 이용한 소금쟁이 로봇 제작

박기성(Ki Sung Park),이주현(Joo Hyun Lee),서종화(Jong Hwa Seo),조찬섭(Chan Seob Cho),김봉환(Bong Hwan Kim),이인수(In-Soo Lee) 한국정보기술학회 2014 Proceedings of KIIT Conference Vol.2014 No.5

본 논문에서는 소금쟁이로봇을 설계하고 제작하였다 특히 제작한 소금쟁이로봇의 발 부분에는 발수 특성을 가지는 물질인 PTFE (poly tetra fluoro ethylene) 코팅을 함으로써 발수물질을 부착하지 않은 경우에 비해서 이동 속도를 개선되었음을 알 수 있었다 개발한 소금쟁이로봇은 수상의 광범위한 감시활동 및 수질 오염감시 작업등에 활용할 수 있을 것이다. This paper presents a design and implementation of a water strider robot. Especially, PTFE (poly tetra fluoro ethylene) coating, commonly known as a hydrophobic material, was used to improve the moving speed of the proposed water strider robot. From the experimental results we know that the proposed robot system can successfully improve the moving speed.