| AVS 64th International Symposium & Exhibition | |
| Vacuum Technology Division | Tuesday Sessions |
| Session VT-TuP |
| Session: | Vacuum Technology Poster (and Student Poster Competition) |
| Presenter: | Yusuke Nishikawa, Advanced Technology R&D Center Mitsubishi Electric Corp., Japan |
| Authors: | Y. Nishikawa, Advanced Technology R&D Center Mitsubishi Electric Corp., Japan M. Kinugawa, Advanced Technology R&D Center Mitsubishi Electric Corp. |
| Correspondent: | Click to Email |
In the case of small package devices, it is possible to break it in a vacuum chamber and analyze the gas inside. However, when analyzing residual gas with a large package, it is very difficult to prepare a larger chamber and break the sample. Furthermore, if the surface area in the package is large, the influence of desorption of adsorbed molecules cannot be ignored. It is difficult to accurately measure the pressure of residual gas.
In this study, we present a new technique for analyzing gas in sealing devices that can be flexibly applied and can minimize the influence on the state of the residual gas composition even for various large samples.
The testing apparatus consists of a gas sampling chamber and an analysis chamber, with both connected to a vacuum valve and an exchangeable orifice. The analysis chamber has a quadrupole mass spectrometer and is exhausted continuously by a turbomolecular pump. The gas sampling chamber has a perforator, a vacuum gauge, and an additional pumping system. The volume of the gas sampling chamber is sufficiently small relative to the volume of the sample. The package sample is connected directly to the connection port of the gas sampling chamber. By using a small gas sampling chamber, an external connection of the sample, and a variable orifice, this technique can be flexibly applied to various large samples.
We measured the temperature of the internal pressure of a certain package sample. As a result, we found that the pressure increase was five times higher than when considering by the ideal gas law and ion intensity of water was increased. We estimated them as the adsorption and desorption levels of gas on the surface of the internal components.
To further advance this technique, we found that it is important to know the influence of gas adsorption and desorption inside the package. We will research the gas adsorption and desorption for the component parts affecting residual gas partial pressure.
[1] M. Kinugawa, et al.: Mitsubishi Denki giho Vol. 81 No. 3 231 (2007).