Instrument for water vapor transmission rate of thin-film encapsulation in aging environment

Thin-film encapsulation is recognized as the most promising emerging packaging technology, and water vapor transmission rate (WVTR) is one of the most important parameters to evaluate the performance of thin film. In order to measure the WVTR of the thin-film encapsulation in any temperature and humidity environment (especially in aging environment), a new method of WVTR measurement system was designed and developed which is based on the method of calcium electrical test in this paper. Deposited by atomic layer deposition, the WVTR of the different layers Al₂O₃/Alucone thin film encapsulation were measured in 85 °C /85%RH. The results showed that this encapsulation structure had a water vapor barrier effect, prolonging the lifetime of the device and the multiple of accelerated test was obtained by comparison of the experimental results on the high-humidity and on the room temperature and humidity.