Integrated mass flow controller0302101-73
A gas-flow control device integrating microvalves with flowmeters
fabricated by micromachining on a substrate.
An example is as follows. The microvalve consists of silicon and
glass substrates attached to each other. The silicon substrate is processed by silicon
micromachining to produce a port section opened and closed by a diaphragm, and the glass substrate
is processed to incorporate a gas inlet and outlet. The diaphragm is operated by a piezoelectric or
electrostatic actuator. Various types of valve structures, such as a three-way valve structure have
been developed. A thermal-type flow sensor that detects heater temperature drop caused by the
gas-flow is often used. Research and development is targeting the control of the gas flow at a
molecular level for semiconductor manufacturing devices requiring high-purity gas. A small-scale
gas-flow control device that integrates valves and flow sensors has been realized.