• 센서학회지
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• 제27권5호
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• pp.300-305
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• 2018

The uncooled microbolometer thermal sensor for low cost and mass volume was designed to target the new infrared market that includes smart device, automotive, energy management, and so on. The microbolometer sensor features 80x60 pixels low-resolution format and enables the use of wafer-level vacuum packaging (WLVP) technology. Read-out IC (ROIC) implements infrared signal detection and offset correction for fixed pattern noise (FPN) using an internal digital to analog convertor (DAC) value control function. A reliable WLVP thermal sensor was obtained with the design of lid wafer, the formation of Au80%wtSn20% eutectic solder, outgassing control and wafer to wafer bonding condition. The measurement of thermal conductance enables us to inspect the internal atmosphere condition of WLVP microbolometer sensor. The difference between the measurement value and design one is $3.6{\times}10-9$ [W/K] which indicates that thermal loss is mainly on account of floating legs. The mean time to failure (MTTF) of a WLVP thermal sensor is estimated to be about 10.2 years with a confidence level of 95 %. Reliability tests such as high temperature/low temperature, bump, vibration, etc. were also conducted. Devices were found to work properly after accelerated stress tests. A thermal camera with visible camera was developed. The thermal camera is available for non-contact temperature measurement providing an image that merged the thermal image and the visible image.

• 센서학회지
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• 제21권2호
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• pp.121-126
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• 2012

Piezoresistive type contact force sensor array is fabricated by (111) Silicon bulk micromachining for continuous blood pressure monitoring. Length and width of the unit sensor structure is $200{\mu}m$ and $190{\mu}m$, respectively. The gap between sensing elements is only $10{\mu}m$. To achieve wafer level packaging, the sensor structure is capped by PDMS soft cap using wafer molding and bonding process with $10{\mu}m$ alignment precision. The resistance change over contact force was measured to verify the feasibility of the proposed sensor scheme. The maximum measurement range and resolution is 900 mm Hg and 0.57 mm Hg, respectively.

• 마이크로전자및패키징학회지
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• 제23권4호
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• pp.49-55
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• 2016

Nowadays there are magnetic sensors in a wide variety of equipment such as computers, cars, airplanes, medical and industrial instruments. In many of these applications the magnetic sensors offer safe and non-invasive means of detection and are more reliable than other technologies. The electric current in a conductor generates a magnetic field detected by this type of sensor. This work aims to define a package dedicated to an electrical current sensor using a MTJ (Magnetic Tunnel Junction) as a sensing device. Four different proposals of packaging, three variations of the chip on board (CoB) package type and one variation of the thin small outline package (TSOP) were analyzed by COMSOL modeling software by simulating a brad range of current injection. The results obtained from the thermal and magnetic analysis has proven to be very important for package improvements, specially for heat dissipation performance.

• 마이크로전자및패키징학회지
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• 제24권4호
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• pp.9-17
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• 2017

In these days, MEMS (micro-electro-mechanical system) devices become the crucial sensor components in mobile devices, automobiles and several electronic consumer products. For MEMS devices, the packaging determines the performance, reliability, long-term stability and the total cost of the MEMS devices. Therefore, the packaging technology becomes a key issue for successful commercialization of MEMS devices. As the IoT and wearable devices are emerged as a future technology, the importance of the MEMS sensor keeps increasing. However, MEMS devices should meet several requirements such as ultra-miniaturization, low-power, low-cost as well as high performances and reliability. To meet those requirements, several innovative technologies are under development such as integration of MEMS and IC chip, TSV(through-silicon-via) technology and CMOS compatible MEMS fabrication. It is clear that MEMS packaging will be key technology in future MEMS. In this paper, we reviewed the recent development trends of the MEMS packaging. In particular, we discussed and reviewed the recent technology trends of the MEMS bonding technology, such as low temperature bonding, eutectic bonding and thermo-compression bonding.

• 비파괴검사학회지
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• 제30권3호
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• pp.236-243
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• 2010

Fiber Bragg grating(FBG) sensor arrays can be used to monitor the mechanical behavior of the large composite structures such as wind turbine rotor blades and aircrafts. However, brittle FBG sensors, especially multiplexed FBG sensors are easily damaged when they are installed in the flexible structures. As a protection of brittle FBG sensors, epoxy packaged FBG sensors have been presented in this paper. Finite element analysis and experiments were performed to evaluate the effects of adhesives, packaging materials and the bonding layer thickness on the strain transmission. Two types of epoxy were used for packaging FBG sensors and the sensor probes were attached with various bonding layer thickness. It was observed that thin bonding layer with high elastic modulus ratio of the adhesive to packaging provided good strain transmission. However, the strain transmission was significantly decreased when elastic modulus of the adhesive was much lower than the packaged FBG sensor probe's one.

• 한국포장학회지
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• 제14권1호
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• pp.15-22
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• 2008

The excitement over radio frequency identification (RFID) technology has gained momentum in the last five years, with a diversification in the range of applications. Besides academic research into radio frequency identification (RFID) has proliferated over the last few years, however there is much to be desired on Packaging industry. In this paper, we present a literature reviews of researches of RFID system on Packaging, especially focused on RFID system standardization into packaging. There is not any packaging standard or guidance about tag locations, classification with the materials and so on. Therefore it hampers reduction of the distribution costs on political and corporate sides, and lack consistency of applying RFID system. The main focus of this review paper is to establish a constituency about legislating RFID system standard on packaging. It is hoped that the review will be a good resource for future research in order to applly RFID system to Packaging industry effectively.

• 마이크로전자및패키징학회지
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• 제5권2호
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• pp.65-69
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• 1998

본 연구는 전하 결합 영양소자에서 감지회로의 특성을 향상시키기 위하여 N형 MOSFET과 Polysilcon 저항에 의한 전압 분배 회로를 가진 감지회로를 설계하였다. 감지회 로에 흐르는 전류는 전압분배회로를 N형 MOSFET으로 설계하였을때가 Polysilicon 저항으 로 설계한 경우보다 감도 특성도 좋은 것으로 나타났다. 이는 전압분배회로를 Polysilicon으 로 설계한 경우보다 N형 MOSFET으로 설계하였을 때 동작 주파수가 높을수록 전압이득 특성이 우수하기 때문이다. 감지회로에 흐르는 전류는 전압분배회로를 N형 MOSFET으로 설계하였을 때 2mA 정도를 나타내고 polysilcon으로 설계하였을 때 4mAwjd도로 나타났다.

• 마이크로전자및패키징학회지
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• 제26권1호
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• pp.17-21
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• 2019

본 논문에서는 공작기계 등에서 필요로 하는 진직도 측정시스템을 가시광의 레이저와 CMOS 이미지센서를 사용하여 저가로 구현하였다. CMOS 이미지센서를 이용하여 광이미지를 검출하고 영상처리를 통해 진직도 변화를 계산하였다. 레이저와 이미지센서의 거리를 3m로 하여 실험한 진직도 측정에서 오차가 0.9%로 우수함을 확인하였으며, 제작된 진직도 시스템은 3D 프린터 등 다른 응용분야에서도 사용 할 수 있을 것으로 생각된다.

• 마이크로전자및패키징학회지
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• 제24권1호
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• pp.51-56
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• 2017

최근 계측기의 소형화, 전자화에 따라 차압식 유량계의 경우 기존에 기계가공을 통해 개발하던 센서부를 전자식 MEMS 차압센서로 대체하려는 많은 노력이 있으나, MEMS 차압센서의 경우 고압이 인가시 실리콘 다이아프램의 파괴 및 센서의 접합부의 파괴가 발생하는 문제점이 있다. 따라서 본 논문에서는 proof pressure 이상의 압력에서 센서의 다이아프램이 파괴되지 않는 구조를 제안하였으며, 그에 따른 차압식 압력센서를 설계 및 제작하였다. 센서 동작압력(0-3 bar)의 3배 이상의 압력에서 센서의 동작특성을 평가하였다. 개발된 센서는 $3.0{\times}3.0mm$이며, 0~3 bar 사이의 압력에서 LCR meter (HP 4284a)로 측정한 결과 3.67 pF at 0bar, 5.13 pF at 3 bar를 나타내었으며, 센서의 동작압력(0-3 bar)에서 0.37%의 hysteresis를 나타내는 압력센서를 개발하였다.

• 마이크로전자및패키징학회지
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• 제10권3호
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• pp.57-65
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• 2003

본 연구에서는 웨이퍼 레벨 진공 패키징된 MEMS자이로스코프 소자의 신뢰성 시험 및 분석을 통하여 웨이퍼 레벨 진공 패키징의 파괴 메카니즘을 연구하였다. 진공 패키징의 주된 파괴 모드는 누설, 가스투과, 그리고 outgassing이다. 누설은 접합 계면이나 재질의 결함을 통하여 주로 발생되며, 접합폭을 증가시키거나 단결정 실리콘을 사용하면 누설이 감소한다. Outgassing은 실리콘 및 유리기판의 표면 및 내부에서 발생하며 주로 $H_2O$와, $CO_2$, $C_3H_5$ 및 유기 오염물질이었다. Epi-poly의 경우 SOI 웨이퍼보다 약 10배의 outgassing을 발생시킨다. 또한 유리기판을 샌드블라스트 공정을 사용하여 가공한 경우, 약 2.5배의 outgassing 양이 증가한다. Outgassing 제거를 위해서는 접합 전에 웨이퍼를 pre-baking하는 과정이 필수적이며, outgassing의 발생을 최대로 하기 위한 최적의 pre-baking조건은 실리콘과 유리 웨이퍼를 $400^{\circ}C$와 $500^{\circ}C$ 사이에서 pre-baking하는 것이다.