公开(公告)号：US20210088367A1

公开(公告)日：2021-03-25

申请号：US16578371

申请日：2019-09-22

Applicant: APPLIED MATERIALS, INC.

Inventor： Michael Kutney ,  Ashley M. Okada

IPC: G01F1/684 ,  G01F1/698 ,  G01F15/02 ,  G01F1/74

Abstract: Methods and apparatus for a flow ratio controller are provided herein. In some embodiments, a flow ratio controller includes an inlet; a plurality of channels extending from the inlet to a corresponding plurality of outlets; a bypass pipe extending from each channel of the plurality of channels that diverts a small portion of a flow from that channel and then returns the small portion of the flow back to that channel; and a thermal mass flow meter coupled to the bypass pipe having a first temperature sensor, a second temperature sensor, and a heating element disposed therebetween. A controller is configured to determine a flow rate through each of the plurality of channels based on a measured temperature difference between the first temperature sensor and the second temperature sensor.