Method and device for controlling pressure and flow rate
US6131307A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 5, 1998 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Aug 5, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF26B21/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A pressure and flow rate of a gas flowing into or out of a processing chamber are controlled, so as to decrease or increase an atmosphere in the processing chamber higher or lower than a target pressure to obtain a target pressure. During a first period, an opening speed of an opening degree adjusting device provided in an inlet pipe communicating to the processing chamber is controlled to a first target value toward a first predetermined functional approximation line (for example a function of second degree) as ideal value. During the rest of periods other than the first period, the opening speed is controlled stepwise to two or more predetermined target values so that the processing chamber reaches the target pressure. During a period before the first period, the opening speed may be controlled to a second target value among the two or more target values, based on a control amount for the opening degree adjusting device. During another period after the first period, the opening speed may be controlled toward a second predetermined functional approximation line (e.g., linear) as ideal value, which has a larger change than the first functional approximation line, until the second t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.