| 摘要 |
<p>PURPOSE:To prevent a fine dust from entering a main body through a part where sealing of packing is partially improper by increasing pressure within the main body which stores wafers to a higher value than the outside. CONSTITUTION:A lid 1 is used for loading and unloading wafers and the inside of a main body 9 and the external environment are isolated through a packing 2. When pressure within the main body 9 reaches a certain level or less, a valve 7 opens and a clean air within a cylinder 6 is filled into the main body 9 through a tube 8. Also, the valve 7 is closed when pressure within the main body 9 becomes higher than a constant pressure, thus preventing a clean air from flowing from the cylinder 6 into the main body 9. Thus, it becomes possible to increase pressure within the main body 9 as compared with that at the outside, thus preventing dust from entering from the outside.</p> |
