Packaging effect on the flow separation of CMOS thermoresistive micro calorimetric flow sensors

We systematically study the packaging effect on the performance of CMOS Thermoresistive Micro Calorimetric Flow (TMCF) sensors, including two types of sensor packaging designs: S-type and E-type. For S-type design, the experimental results indicate that not only the sensitivity of TMCF sensors was significantly changed by more than 30%, but also the flow range compared to the E-type design was dramatically reduced from 0 - 11 m/s to 0 - 4.5 m/s. Comprehensive CFD simulations and the concise heater transfer analysis were performed to understand the physics behind these two different designs. Accordingly, a flow regime map (the protrusion vs the reduced Reynolds number) was constructed, where the critical boundary curve for the flow separation of CMOS TMCF sensors was determined. This flow regime map is a useful guideline for designing a well packaged flow sensor system.