• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.990-995
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• 2005

This paper reports the fabrication and characterization of $5\;\times\;5$ thermal cantilever array for nano-scaled memory device application. The $5\;\times\;5$ thermal cantilever array with integrated tip heater has been fabricated with MEMS technology on SOI wafer using 7 photo masking steps. All single-level cantilevers have a diode in order to eliminate any electrical cross-talk between adjacent tips. Electrical measurements of fabricated thermal cantilever away show its own thermal heating mechanism. Thermal heating is demonstrated by the reflow of coated photoresist on the cantilever array surface.

• 비파괴검사학회지
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• 제32권2호
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• pp.185-191
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• 2012

일반적으로 위상배열 초음파검사 기법을 이용한 배관 용접부검사에서는 높은 검사 각도를 효과적으로 발생하기 위하여 ��지를 사용하게 된다. 그러나 용접부 또는 접근이 제한된 부위에 대한 검사는 위상 배열 초음파 탐촉자에 ��지를 부착하게 되면 ��지의 전단 길이로 인하여 검사체적을 포함하지 못하는 등의 문제점이 발생하게 된다. 따라서 ��지를 사용하지 않고 높은 검사 각도를 발생할 수 있는 횡파 위상배열 초음파 탐촉자를 적용해야 할 필요성이 있다. 본 연구에서는 굴절각도가 높은 횡파를 발생할 수 있는 위상배열 초음파 탐촉자를 설계하고 제작하여 다양한 깊이의 EDM 노치가 가공된 시험편에서 결함이 정확하게 검출되고 평가될 수 있는 지를 확인하였다. 결과적으로 본 연구에서 설계된 횡파 위상배열 초음파 탐촉자는 다양한 깊이의 결함을 검출하고 신뢰성 있는 정밀도를 나타내었으므로 향후 접근제한이 예상되는 발전설비 구조물의 검사에 적용된다면 효과적인 검사 결과를 보여줄 것으로 기대된다.

• 한국소음진동공학회논문집
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• 제15권2호
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• pp.184-191
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• 2005

The near-field scanning micro scope (NSOM) technique is in the spotlight as the next generation storage device. Many different types of read/write mechanism for NSOM have been introduced in the literature. In order for a near-field probe to be successfully implemented in the system, a suitable slider and suspension are needed to be properly designed. The optical slider is designed considering near-filed optics and probe array. The suspension generally supports slider performance, and tracking servo capacity in HDD. Moreover, the suspension for optical slider also should meet the optical characteristics, and is also required to satisfy shock performances for the mobility for the actuator. In this study, the optical slider and the suspension for near-field probe array are designed and analyzed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.393-398
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• 2004

The near-field scanning micro scope (NSOM) technique is in the spotlight as the next generation storage device. Many different types of read/write mechanism for NSOM have been introduced in the literature. In order for a near-field probe to be successfully implemented in the system, a suitable slider and suspension are needed to be properly designed. The optical slider is designed considering near-filed optics and probe array. The suspension generally supports slider performance, and tracking servo capacity in HDD. Moreover, the suspension for optical slider also should meet the optical characteristics, and is also required to satisfy shock performances for the mobility for the actuator. In this study, the optical slider and the suspension fer near-field probe array are designed and analyzed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1718-1723
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• 2007

The Probe Card is a test component which is to classify the good semiconductor chips before the packaging. The yield of semiconductor product can be better from analysis of probe test information. Recently the technology of the probe card needs narrow width and large amount of probe tip. In this research, the probe tip based on the MEMS(micro electro mechanical system) technology was designed and fabricated to improve the reliability of the test and to meet 2-dimensional Array of tip. The mechanical and electrical properties of proposed tip were evaluated and it has over 100,000 of repetition times in the condition of 5gf, $20{\mu}m$ Over Drive.

• 정보저장시스템학회논문집
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• 제1권1호
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• pp.73-77
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• 2005

In this paper, a new silicon nitride cantilever integrated with silicon heater and piezoelectric sensor has been firstly developed to improve the uniformity of the initial bending and the mechanical stability of the cantilever array for thermo-piezoelectric SPM(scanning probe microscopy) -based data storages. This nitride cantilever shows thickness uniformity less than $2\%$. Data bits of 40 nm in diameter were recorded on PMMA film. The sensitivity of the piezoelectric sensor was 0.615 fC/nm after poling the PZT layer. For high speed operation, 128${\times}$128 probe array was developed.

• 한국압력기기공학회 논문집
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• 제9권1호
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• pp.8-14
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• 2013

Steam turbine blades and discs of nuclear power plants are one of the most highly stressed areas of turbine rotor, and periodic inspection of the blade roots is essential for monitoring integrity and preventing turbine failure. Ultrasonic technique is applied for volumetric inspection of blade root. However, the complexity of blade root geometry imposes challenges to inspection of blades and discs. Recently, phased array ultrasonic inspection technology is being applied to numerous power generation inspection applications including turbine rotor. The phased array ultrasonic technique requires customized inspection wedges which are generally necessary to generate effectively higher incident angle. But the usage of this wedge can cause access limitation for the lower stage blades of turbine because of the wedge front length. Therefore, the shear wave phased array probe which can generate high inspection angle without wedge is essentially necessary. In this study, feasibility study is conducted for the shear wave phased array ultrasonic probe application to blade and disc inspection. As results, the experimental results show that the shear wave phased array probe can detect the flaw and measure its size with reliable accuracy. Therefore if this shear wave phased array probe is applied to field inspection of blade and disc, more reliable inspection is expected for turbine having access limitation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.650-653
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• 2002

In this paper, a methodology to assess machine tool errors quickly is suggested using a touch probe and a cube array artifact. Parameterized error models derived are expressed of model coefficient vectors and backlash errors to be determined. To determine the unknown model coefficient vectors, a cube array artifact is proposed. Considering CMM measurement data of cube vertex coordinates. error vectors for all axes ate obtained and used to complete the error model. Some simulation results show that the suggested error model can follow the true values within 10$\mu\textrm{m}$. To verify the error model, a circular part with two concentric circles is measured and simulated. The results show that the differences between CMM and OMM radius errors are smaller than 15$\mu\textrm{m}$.

• 비파괴검사학회지
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• 제30권4호
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• pp.330-337
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• 2010

본 논문은 원전 증기발생기(SG, steam generator) 세관의 정밀 진단을 위한 차세대 탐촉자인 배열형 와전류 탐촉자의 특성 해석에 대한 3차원 전자기 수치해석을 수행하였다. 다양한 결함 해석을 위해 ASME(American Society of Mechanical Engineers) 표준시험편과 X-probe combo 표준보정시험편(inline EXP/spiral groove combo standard)을 선정하여 탐상신호를 획득하고, 실제 실험 신호와 비교하여 결과의 타당성을 검증하였다. 표준 보정 시험편의 해석 결과를 바탕으로 원전 SG 세관에서 주로 발생하고 있는 pitting, SCC(stress corrosion cracking), multiple SCC, wear 결함에 대하여 탐상신호를 획득하였다. 해석 대상으로는 원자력발전소 SG 세관으로 사용하고 있는 Inconel 600 도체관을 사용하였고, 이때의 시험주파수는 300 kHz이다. 본 논문을 통하여 각각의 결함에 대한 신호 특성을 파악하여 배열형 와전류 탐촉자의 결함의 종류에 따른 신호 특성을 확인할 수 있었다. 본 논문의 결과는 배열형 와전류 탐촉자의 와전류 탐상 신호 평가시 도움이 될 것이다.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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• pp.54-58
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• 2009

In this paper, the ECT(eddy current testing) signal analysis of eddy current array probe for inspection of SG(steam generator) tube in NPP(nuclear power plant) using electromagnetic FEM(finite element method) was performed. To obtain the electromagnetic characteristics of probes, the governing equation was derived from Maxwell's equation, and the problem was solved by using the 3-dimensional FEM. The types of defects were FBH(flat bottomed hole) and OD groove, Spiral groove, natural defects(pitting, SCC, multiple SCC, wear). The depth of FBH defects were 20%, 40%, 60%, 80%, 100 of SG tube thickness, and it was assumed that the defects were located on the tube outside. And the operation frequency of 100kHz, 300kHz and 400kHz were used. Material of specimen was Inconel 600 which is usually used for SG tubes in NPP. The signal difference could be observed according to the variation of size and depth on FBH defects and operation frequencies. The results in this paper can be helpful when the ECT signals from EC array probe are evaluated and analyzed.