• 품질경영학회지
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• 제41권4호
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• pp.659-672
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• 2013

Purpose: The purpose of this study was to estimate life time of halogen lamps and acceleration factors using accelerated life test. Methods: Voltage was selected as an accelerating variable through the technical review about failure mechanism. The test was performed at 14.5V, 15.5V and 16.5 for 4,471 hours. It was assumed that the lifetime of Halogen lamps follow Weibull distribution and the inverse power life-stress relationship models. Results: Mean lifetimes of pin and screw types were 19,477 hours and 6,056 hours, respectively. In addition, acceleration factor of two items are calculated as 4.8 and 2.2 based on 15.5V, respectively. Conclusion: The life-stress relationship, acceleration factor, and MTTF at design condition are estimated by analyzing the accelerated life test data. These results suggest that voltage was very important factor to accelerate life time in the case of halogen lamps and the life time of pin type is three times longer than screw type lamps.

• 마이크로전자및패키징학회지
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• 제11권2호
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• pp.53-58
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• 2004

63Sn-37Pb 공정솔더의 electromigration 현상을 용이하게 관찰하기 위해 63Sn-37Pb 공정솔 더를 증착하여 스트립 형태의 시편을 제작 후 electromigration 테스트를 실시하였다. $80{\sim}150^{\circ}C$의 온도 및 $1{\times}10^4{\sim}1{\times}10^5\;A/cm^2$의 전류밀도에서 electromigration 테스트시 스트립 형상의 63Sn-37Pb 솔더 합금에서 hillock과 void의 발생이 관찰되었으며, 온도와 전류밀도가 높아질수록 void의 형성이 빨라져서 평균파괴시간이 단축되었다. 평균파괴시간을 이용하여 Black의 식으로부터 구한 63Sn-37Pb 솔더 스트립의 electromigration에 대한 활성화 에너지는 $0.16{\sim}0.5\;eV$이었다.

• 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.