• Journal of Korean Society for Quality Management
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• v.41 no.4
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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.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.2 s.31
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• pp.53-58
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• 2004

To facilitate the observation of the electromigration of 63Sn-37Pb eutectic solder, strip-type samples were fabricated by solder evaporation. The electromigration test for the 63Sn-37Pb solder strip was conducted at temperatures of $80{\sim}150^{\circ}C$ and the current densities of $1{\times}10^4{\sim}1{\times}10^5\;A/cm^2$. With increasing temperature and the current density, mean-time-to-failure(MTTF) decreased due to the formation of hillock and void in the solder strip. The activation energy for the electromigration in the 63Sn-37Pb solder strip was analyzed as $0.16{\sim}0.5\;eV$ using Black's equation.

• Journal of Sensor Science and Technology
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• v.27 no.5
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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.