Title :
A constant-temperature gas flowmeter with a silicon micromachined package
Author :
Mastrangelo, C.H. ; Muller, R.S.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., California Univ., Berkeley, CA, USA
Abstract :
A micromachined flowmeter based on convective heat transfer from hot, heavily doped polycrystalline silicon bridges was designed, fabricated, packaged, and tested. The flowmeter consists of two basic sensing units: one is exposed to the flow while the other acts as a reference. A silicon cap with a micromachined laminar-flow channel is placed on top of the sensor chip to confine the flow. The polysilicon bridge resistors operate at a constant temperature under the control of external circuits. An output signal voltage of 35 mV is obtained for air flow in the range of 0-100 SCCM at an average device temperature of 250 degrees C. The applied heating power is 8 mW.<>
Keywords :
convection; electric sensing devices; elemental semiconductors; flowmeters; silicon; 250 degC; 35 mV; 8 mW; bridge resistors; convective heat transfer; gas flowmeter; micromachined laminar-flow channel; micromachined package; polycrystalline Si; reference; Bridge circuits; Heat transfer; Packaging; Resistors; Silicon; Temperature control; Temperature distribution; Temperature sensors; Testing; Voltage;
Conference_Titel :
Solid-State Sensor and Actuator Workshop, 1988. Technical Digest., IEEE
Conference_Location :
Hilton Head Island, SC, USA
DOI :
10.1109/SOLSEN.1988.26429
