The si is etched from the back surface of the wafer

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Unformatted text preview: he valve seating ring. D ETECTOR ELEMENT A thin metal resistor is deposited and etched over SiO2. The Si is etched from the back surface of the wafer to remove thermally conductive Si. The sensor detects variations in the thermal conductivity of the gas stream by measuring the resistance of the metal resistor which is subjected to an external constant current source. Joule-Thomson Minirefrigeration System Hillary Lok Lee Yap *Employs the advantageous characteristics of anodic bonding *Refrigeration system based on silicon anisotropic etching and anodic bonding Minirefrigeration System *For a refrigeration system: * Cooling capacities in the 1-100mW range at 77K * Cool down rates in the order of seconds * Operating times of 100’s of hours *Require: * Total channel length of about 25cm * 100μm in diameter Minirefrigeration System *Single-Crystal Silicon can be designed to work well *Advantages: * High strength * Nature of bonding process presupposes an excellent match in thermal coefficients of expansion of the two materials *Disadvantages: * Silicon has very high thermal conductivity *Extr...
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This note was uploaded on 02/03/2014 for the course ME 119 taught by Professor Lwlin during the Spring '08 term at University of California, Berkeley.

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