A mass flow controller, based on an integrated flow sensor and a thermally actuated solid state regulator, is presented. The sensor is a miniaturized differential calorimeter obtained by postprocessing a silicon chip fabricated by a standard microelectronic process. The regulator consists in a microchannel etched into the surface of a silicon substrate and sealed with a glass plate, joined to the silicon die using anodic bonding. Flow regulation is achieved by varying the channel temperature by means of a chromium resistor. The two devices are connected in closed-loop through a low noise—low offset electronic circuit. Experimental data, demonstrating the effectiveness of the flow controller, are presented. Limitations of the proposed approach and possible improvements are discussed.
A Closed-Loop Mass Flow Controller Based on Static Solid-State Devices
BRUSCHI, PAOLO;PIOTTO, MASSIMO
2006-01-01
Abstract
A mass flow controller, based on an integrated flow sensor and a thermally actuated solid state regulator, is presented. The sensor is a miniaturized differential calorimeter obtained by postprocessing a silicon chip fabricated by a standard microelectronic process. The regulator consists in a microchannel etched into the surface of a silicon substrate and sealed with a glass plate, joined to the silicon die using anodic bonding. Flow regulation is achieved by varying the channel temperature by means of a chromium resistor. The two devices are connected in closed-loop through a low noise—low offset electronic circuit. Experimental data, demonstrating the effectiveness of the flow controller, are presented. Limitations of the proposed approach and possible improvements are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
