公开(公告)号：US20210180599A1

公开(公告)日：2021-06-17

申请号：US17111958

申请日：2020-12-04

Applicant: CKD CORPORATION

Inventor： Yutaro HAYASE

IPC: F04C28/24 ,  G05D7/06

Abstract: A vacuum pressure control system that can easily calculate an optimum valve open degree of a vacuum control valve for making a pressure value of a vacuum chamber agree with a target value is provided. A controller approximates a relation between the pressure value in the vacuum chamber and a flow rate of process gas to linear functions, and the system includes a mapping program and a valve-open-degree calculation program stored in the controller to calculate the optimum valve open degree of the vacuum control valve for making the pressure value in the vacuum chamber agree with the target value based on the linear functions when the process gas at the predetermined flow rate is supplied. The valve open degree of the vacuum control valve is adjusted based on the optimum valve open degree so that the pressure value in the vacuum chamber is made agree with the target value.