• 한국정보통신학회논문지
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• 제12권10호
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• pp.1822-1829
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• 2008

항체가 정밀한 항법 정보를 얻기 위해서는 관성 센서의 초기 오차에 대한 보정이 매우 중요하다. 본 논문에서는 레이트 테이블과 고성능 센서를 기준 센서로 사용하여, 저급 MEMS 관성 센서 오차 보정에 따르는 비용과 효율성의 어려움을 극복하는 방법을 제안하였다. 초기 오차 보정 과정에서 기준 센서와 타겟 센서에 같은 동적 입력을 인가한 후 결과를 분석하였다. 실험 결과를 통해 제안된 초기 오차 보정 방법이 실제로 매우 효율적이며 유용함을 확인할 수 있었다.

• 마이크로전자및패키징학회지
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• 제15권2호
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• pp.29-36
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• 2008

본 연구에서는 MEMS 소자의 직접화 및 소형화에 필수적인 through-wafer via interconnect의 신뢰성 문제를 연구하였다. 이를 위하여 Au-Sn eutectic 접합 기술을 이용하여 밀봉(hermetic) 접합을 한 웨이퍼 레벨 MEMS 패키지 소자를 개발하였으며, 전기도금법을 이용하여 수직 through-hole via 내부를 구리로 충전함으로써 전기적 연결을 시도하였다. 제작된 MEMS 패키지의 크기는 $1mm{\times}1mm{\times}700{\mu}m$이었다. 제작된 MEMS패키지의 신뢰성 수행 결과 비아 홀(via hole)주변의 크랙 발생으로 패키지의 파손이 발생하였다. 구리 through-via의 기계적 신뢰성에 영향을 줄 수 있는 여러 인자들에 대해서 수치적 해석 및 실험적인 연구를 수행하였다. 분석 결과 via hole의 크랙을 발생시킬 수 있는 파괴 인자로서 열팽창 계수의 차이, 비아 홀의 형상, 구리 확산 현상 등이 있었다. 궁극적으로 구리 확산을 방지하고, 전기도금 공정의 접합력을 향상시킬 수 있는 새로운 공정 방식을 적용함으로써 비아 홀 크랙으로 인한 패키지의 파괴를 개선할 수 있었다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.104-108
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• 2000

In this paper, we characterized a novel MEMS package using high resistivity silicon for microwave and millimeter-wave devices. The manufactured MEMS package shows -20dB of S$\sub$11/ and -0.4dB of S$\sub$21/ up to 200GHz. The new package can be a low cost and high performance solution due to process compatibility with on-chip devices and very small and precise dimensions by semiconduotor technology.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권5호
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• pp.396-401
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• 1999

In this study, $Ar^+$ ion laser etching process of single/poly-crystalline Si with $CCl_2F_2$ gas is investigated for MEMS applications. In general, laser direct etching process is useful in microelectronic process, fabrication of micro sensors and actuators, rapid prototyping, and complementary processing because of the advantages of 3D micromachining, local etching/deposition process, and maskless process with high resolution. In this study, a pyrolytic method, in which $CCl_2F_2$ gasetches molten Si by the focused laser, was used. In order to analyze the temperature profile of Si by the focused laser, the 3D heat conduction equation was analytically solved. In order to investigate the process parameters dependence of etching characteristics, laser power, $CCl_2F_2$ gas pressure, and scanning speed were varied and the experimental results were observed by SEM. The aspect ratio was measured in multiple scanning and the simple 3D structure was fabricated. In addition, the etching characteristics of $6\mum$ thick poly-crystalline Si on the insulator was investigated to obtain flat bottom and vertical side wall for MEMS applications.

• 센서학회지
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• 제15권2호
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• pp.148-152
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• 2006

This paper describes the fabrication of SiCN microstructures for super-high temperature MEMS using photopolymerization of pre-ceramic polymer. In this work, polysilazane liquide as a precursor was deposited on Si wafers by spin coating, microstructured and solidificated by UV lithography, and removed from the substrate. The resulting solid polymer microstructures were cross-linked under HIP process and pyrolyzed to form a ceramic of withstanding over $1400^{\circ}C$. Finally, the fabricated SiCN microstructures were annealed at $1400^{\circ}C$ in a nitrogen atmosphere. Mechanical characteristics of the SiCN microstructure with different fabrication process conditions were evaluated. The elastic modules, hardness and tensile strength of the SiC microstructure implemented under optimum process condtions are 94.5 GPa, 10.5 GPa and 11.7 N/min, respectively. Consequently, the SiCN microstructure proposed in this work is very suitable for super-high temperature MEMS application due to very simple fabrication process and the potential possiblity of sophisticated mulitlayer or 3D microstructures as well as its good mechanical properties.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.187-188
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• 2005

In this paper, big free standing metal structures for electrostatic MEMS switches are easily fabricated using photoresist sacrificial layer. The entire process sequence, through the removal of the sacrificial layer, is kept below 150 $^{\circ}C$ to avoid curing problem of photoresist sacrificial layer. Metal structure is fabricated by thermal evaporator and a self test electrode is fabricated underlying metal suspended structure for testing by electrostatic force. The new wet release process is considered using methanol rinse, general wet release process cause stiction problem by capillary force during drying, and the yield is dramatically improved than previous wet release process using DI water rinse. The fabrication becomes much simpler and cheaper with use of a photoresist sacrificial layer.

• Transactions on Electrical and Electronic Materials
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• 제14권2호
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• pp.63-66
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• 2013

This paper describes the highly productive process technologies of microprobe arrays, which were used for a probe card to test a Dynamic Random Access Memory (DRAM) chip with fine pitch pads. Cantilever-type microprobe arrays were fabricated using conventional micro-electro-mechanical system (MEMS) process technologies. Bonding material, gold-tin (Au-Sn) paste, was used to bond the Ni-Co alloy microprobes to the ceramic space transformer. The electrical and mechanical characteristics of a probe card with fabricated microprobes were measured by a conventional probe card tester. A probe card assembled with the fabricated microprobes showed good x-y alignment and planarity errors within ${\pm}5{\mu}m$ and ${\pm}10{\mu}m$, respectively. In addition, the average leakage current and contact resistance were approximately 1.04 nA and 0.054 ohm, respectively. The proposed highly productive microprobes can be applied to a MEMS probe card, to test a DRAM chip with fine pitch pads.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.392-393
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• 2006

This paper describes the fabrication of SiCN microstructures for super-high temperature MEMS using photopolymerization of pre-ceramic polymer. In this work. polysilazane liquide as a precursor was deposited on Si wafers by spin coating. microstructured and solidificated by UV lithography. and removed from the substrate. The resulting solid polymer microstructures were cross-linked under HIP process and pyrolyzed to form a ceramic of withstanding over $1400^{\circ}C$. Finally, the fabricated SiCN microstructures were annealed at $1400^{\circ}C$ in a nitrogen atmosphere. Mechanical characteristics of the SiCN microstructure with different fabrication process conditions were evaluated. The elastic modules. hardness and tensile strength of the SiC microstructure implemented under optimum process conditions are 94.5 GPa, 10.5 GPa and 11.7 N/min, respectively. Consequently, the SiCN microstructure proposed in this work is very suitable for super-high temperature MEMS application due to very simple fabrication process and the potential possiblity of sophisticated multlayer or 3D microstructures as well as its good mechanical properties.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.169-174
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• 2001

This paper reports on the development of high aspect ratio structure and 3-D integrated process for MEMS-based micro gas turbines. To manufacture high aspect ratio structures, Deep Reactive Ion Etching (DRIE) process have been developed and optimized. Specially, in this study, structures with aspect ratios greater than 10 were fabricated. Also, wafer direct bonding and Infra-Red (IR) camera bonding inspection systems have been developed. Moreover, using glass/silicon wafer direct bonding, we optimized the 3-D integrated process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.152-152
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• 2008

Micro probe with Ni-Co tip was designed. Unit processes for fabricating the micro probe were developed. We are investigated the micro probe tip using by Ni-Co alloy. One-step and three-step needle was fabricated by plating process, CMP, and photolithography process. The plating thickness was varied by current density and time. Futher data will be extract by different process conditions.