Abstract
Abstract A monolithic design and fabrication process is proposed and realized for the thermal buckling micro valve and the built-in flow channel mass flow sensor modules in the thesis. The manufacturing procedure for the mass flow sensing and control devices design, fabrication, package, and testing is standardized through the concept of module design and the common testing platform. There are two types of built-in flow channel mass flow sensor fabricated in the thesis; one is silicon membrane type, the other is polyimide membrane type. The sensitivity of the silicon membrane type flow sensor is about 1sccm for nitrogen measurement biased by constant voltage for 0~300 sccm measurement range. The silicon membrane type flow sensor could also be applied for liquid flow measurement. The water flow measurement range is about 3g/min。An easy way to compare different sensor characteristics is proposed to show the better sensor structure design. The polyimide membrane type flow sensor exhibits superior characteristics than the silicon membrane type by this way. The measurement range and linearity of the polyimide membrane type flow sensor is significantly improved by the introduction of Silicon Channel Modulator. Three thermal buckling micro valves are fabricated in the thesis; membrane-type, bridge-type and cross-type. The flow control range of the membrane-type micro valve is about 16 sccm. The flow control range of the bridge-type micro valve is improved to 165 sccm. The response time of the bridge-type micro valve is measure: 349 ms to open, 572 ms to close.