| AVS 54th International Symposium | |
| Vacuum Technology | Thursday Sessions |
| Session VT-ThP |
| Session: | Vacuum Technology Poster Session (including Student Poster Competition with Cash Award) |
| Presenter: | M. Kinugawa, Mitsubishi Electric Corp., Japan |
| Authors: | M. Kinugawa, Mitsubishi Electric Corp., Japan H. Kurokawa, Mitsubishi Electric Corp., Japan S. Takagi, Mitsubishi Electric Corp., Japan H. Kawata, Wave Technology Inc., Japan |
| Correspondent: | Click to Email |
Hermetically sealed packages are widely applied to optical and high-frequency devices to maintain high reliability. The inert gasses, which are usually inserted in such packages, might contain such impurities as moisture that could damage the device. Therefore, it is crucial to know the variety and the amount of impurities in the filled gas. In this study, we show a new technique for analyzing gas in sealed packages. The advantage of our new technique is that analysis precision does not depend on package size. The testing apparatus consists of a sample chamber and an analysis chamber; they are both connected to a vacuum-tight valve and an exchangeable orifice. The analysis chamber has a quadrupole mass spectrometer and is exhausted continuously by a turbomolecular pump. The sample chamber has a rotating vacuum feedthrough that can mount several types of sample stages, a perforator, a viewport, and another pumping system. After setting sample packages on the sample stage, the sample chamber is pumped down by the pumping system. Then the pump is switched off, and the valve between the two chambers is opened, so the sample chamber will only be exhausted from the analysis chamber through the orifice. A pinhole is made on the sample package by the perforator. The gas in the sample package comes out and flows through the orifice from the sample chamber to the analysis chamber, and then the mass spectrometer in the analysis chamber detects the gas. We can get the gas composition from the integral ion intensity measured by the mass spectrometer and its ion sensitivity. The conductance of the orifice is determined by considering the sample size and the maximum vacuum pressure in the analysis chamber to keep the pressure a little lower than the working upper limit of the mass spectrometer. This technique allows accurate measurements of gas composition regardless of size package. We have already applied this technique to the development of new devices with higher reliability.