Patents by Inventor Yahong Yao
Yahong Yao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11927555Abstract: The design and structure of a fluidic concentration metering device with a full dynamic range utilizing micro-machined thermal time-of-flight sensing elements is exhibited in this disclosure. With an additional identical sensing chip but packaged at the different locations in the measurement fluidic chamber with a closed conduit, the device can simultaneously measure the fluidic concentration and the fluidic flowrate. With a temperature thermistor integrated on the same micro-machined thermal sensing chip, the disclosed device will be able to provide the key processing parameters for the fluidic applications.Type: GrantFiled: May 25, 2021Date of Patent: March 12, 2024Assignee: Siargo Ltd.Inventors: Liji Huang, Yahong Yao, Li Chen, Chih-Chang Chen
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Publication number: 20220381716Abstract: The design and structure of a fluidic concentration metering device with a full dynamic range utilizing micro-machined thermal time-of-flight sensing elements is exhibited in this disclosure. With an additional identical sensing chip but packaged at the different locations in the measurement fluidic chamber with a closed conduit, the device can simultaneously measure the fluidic concentration and the fluidic flowrate. With a temperature thermistor integrated on the same micro-machined thermal sensing chip, the disclosed device will be able to provide the key processing parameters for the fluidic applications.Type: ApplicationFiled: May 25, 2021Publication date: December 1, 2022Applicant: Siargo Ltd.Inventors: Liji Huang, Yahong Yao, Li Chen, Chih-Chang Chen
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Patent number: 10908006Abstract: The micromachined liquid flow sensor devices are enclosed with silicon nitride film as passivation layer to protect device from penetration of liquid into device and avoid the damages of erosion or short circuit etc. One thin layer of silicon dioxide is deposited underneath the silicon nitride layer to enhance the adhesion and reliability of the passivation layer for various applications. The incorporation of silicon dioxide film had successfully provided reliable passivation protection especially for microfluidic devices application. In order to avoid flow turbulence caused by wire bonding wires, the wire bonding wires are omitted by deploying through-substrate conductive vias whereas connected to the carrier printed circuit board of sensor chip. The present invention disclosed a novel micromachining process and designed structure to form hermit sealing between the sensor chip and the carrier printed circuit board.Type: GrantFiled: February 19, 2019Date of Patent: February 2, 2021Assignee: Siargo Ltd.Inventors: Chih-Chang Chen, Liji Huang, Yahong Yao
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Publication number: 20200264022Abstract: The micromachined liquid flow sensor devices are enclosed with silicon nitride film as passivation layer to protect device from penetration of liquid into device and avoid the damages of erosion or short circuit etc. One thin layer of silicon dioxide is deposited underneath the silicon nitride layer to enhance the adhesion and reliability of the passivation layer for various applications. The incorporation of silicon dioxide film had successfully provided reliable passivation protection especially for microfluidic devices application. In order to avoid flow turbulence caused by wire bonding wires, the wire bonding wires are omitted by deploying through-substrate conductive vias whereas connected to the carrier printed circuit board of sensor chip. The present invention disclosed a novel micromachining process and designed structure to form hermit sealing between the sensor chip and the carrier printed circuit board.Type: ApplicationFiled: February 19, 2019Publication date: August 20, 2020Applicant: Siargo Ltd.Inventors: Chih-Chang Chen, Liji Huang, Yahong Yao
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Patent number: 8794082Abstract: An apparatus comprising a micromachined (a.k.a. MEMS, Micro Electro Mechanical Systems) silicon flow sensor, a flow channel package, and a driving circuitry, which operates in a working principle of thermal time-of-flight (TOF) to measure gas or liquid flow speed, is disclosed in the present invention. The micromachining technique for fabricating this MEMS time-of-flight silicon thermal flow sensor can greatly reduce the sensor fabrication cost by batch production. This microfabrication process for silicon time-of-flight thermal flow sensors provides merits of small feature size, low power consumption, and high accuracy compared to conventional manufacturing methods. Thermal time-of-flight technology in principle can provide accurate flow speed measurements for gases regardless of its gas compositions. In addition, the present invention further discloses the package design and driving circuitry which is utilized by the correlated working principle.Type: GrantFiled: February 25, 2011Date of Patent: August 5, 2014Assignee: Siargo Ltd.Inventors: Liji Huang, Xiaozhong Wu, Yahong Yao, Chih-Chang Chen
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Publication number: 20120216629Abstract: An apparatus comprising a micromachined (a.k.a. MEMS, Micro Electro Mechanical Systems) silicon flow sensor, a flow channel package, and a driving circuitry, which operates in a working principle of thermal time-of-flight (TOF) to measure gas or liquid flow speed, is disclosed in the present invention. The micromachining technique for fabricating this MEMS time-of-flight silicon thermal flow sensor can greatly reduce the sensor fabrication cost by batch production. This microfabrication process for silicon time-of-flight thermal flow sensors provides merits of small feature size, low power consumption, and high accuracy compared to conventional manufacturing methods. Thermal time-of-flight technology in principle can provide accurate flow speed measurements for gases regardless of its gas compositions. In addition, the present invention further discloses the package design and driving circuitry which is utilized by the correlated working principle.Type: ApplicationFiled: February 25, 2011Publication date: August 30, 2012Applicant: Siargo Ltd.Inventors: Liji Huang, Chih-Chang Chen, Yahong Yao, Xiaozhong Wu
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Patent number: 8132455Abstract: A micromachined thermal mass flow sensor comprises a high mechanical strength polyimide film as a supporting layer of suspending membrane. The polyimide film provides superior thermal insulating properties to reduce the power consumption of device. Due to the tendency of humidity absorption, the polyimide suspending membrane is double side passivated on both top and bottom surfaces to sustain its long term stability from rush and humid working environment. A thin layer of silicon dioxide deposited by plasma enhanced chemical vapor deposition is overlaid between the silicon nitride and polyimide film to enhance the adhesion property of passivation layers to polyimide surface. With such embodiments, a sturdy and robust micromachined thermal mass flow sensor with high measurement accuracy could be formed.Type: GrantFiled: August 10, 2009Date of Patent: March 13, 2012Inventors: Chih-Chang Chen, Gaofeng Wang, Liji Huang, Yahong Yao
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Patent number: 7908096Abstract: An integrated mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or P-type silicon substrate with orientation <100>. This mass flow sensor comprises an upstream thin-film heater, an downstream thin-film heater, and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heaters and the sensors out of contact with the substrate base. This mass flow sensor is operated with three sets of circuits, a first circuit for measuring a flow rate in a first range of flow rates, a second circuit for measuring a flow rate in a second range of flow rates, and a third circuit in a differential configuration for measuring a flow rate in said first range of flow rates or said second range of flow rates, to significantly increase range of flow rate measurements and provide an optional for concentration measurement, while maintains a high degree of measurement accuracy.Type: GrantFiled: September 28, 2007Date of Patent: March 15, 2011Assignee: Siargo Ltd.Inventors: Gaofeng Wang, Chih-Chang Chen, Yahong Yao, Liji Huang
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Publication number: 20110030468Abstract: The present invention is generally related to a novel micromachining thermal mass flow sensor and, more particularly, to a device incorporated with high strength and robust characteristics, which therefore is capable of operating under harsh environments. The new disclosed sensor is made of essential material which can provide robust physical structure and superior thermal properties to support the flow measuring operation. The invented thermal mass flow sensor is featuring with the advantages of micro-fabricated devices in terms of compact size, low power consumption, high accuracy and repeatability, wide dynamic range and easiness for mass production, which could avoid the drawbacks of fragility and vulnerability.Type: ApplicationFiled: August 10, 2009Publication date: February 10, 2011Applicant: SIARGO, LTD.Inventors: Chih-Chang Chen, Gaofeng Wang, Liji Huang, Yahong Yao
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Patent number: 7878056Abstract: The current invention generally relates to Micro Electro Mechanical Systems (MEMS) thermal mass flow sensors for measuring the flow rate of a flowing fluid (gas/liquid) and the methods of manufacturing on single crystal silicon wafers. The said mass flow sensors have self-cleaning capability that is achieved via the modulation of the cavity of which the sensing elements locate on the top of the cavity that is made of a silicon nitride film; alternatively the sensing elements are fabricated on top of a binary silicon nitride/conductive polycrystalline silicon film under which is a porous silicon layer selective formed in a silicon substrate. Using polycrystalline silicon or the sensing elements as electrodes, an acoustic wave can be generated across the porous silicon layer which is also used for the thermal isolation of the sensing elements.Type: GrantFiled: December 19, 2007Date of Patent: February 1, 2011Assignee: Siargo Ltd.Inventors: Liji Huang, Chih-Chang Chen, Yahong Yao, Gaofeng Wang
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Patent number: 7780343Abstract: A device with micromachined (a.k.a. MEMS, Micro Electro Mechanical Systems) silicon sensor to measure gas or liquid concentration in a binary mixture formality is disclosed in the present invention. A process for fabricating the said MEMS silicon concentration sensor, which thereby can greatly reduce the sensor fabrication cost by a batch production, is revealed as well. This MEMS process can mass-produce the sensors on silicon substrate in the ways of small size, low power, and high reliability. In addition to the gas or liquid concentration measurement, the present invention further discloses that the said sensor can also readily measure gas or liquid mass flow rate while record the concentration data, which is not viable by other related working principle.Type: GrantFiled: July 9, 2007Date of Patent: August 24, 2010Assignee: Siargo Ltd.Inventors: Chih-Chang Chen, Yahong Yao, Gaofeng Wang, Liji Huang
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Patent number: 7765679Abstract: A mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or lightly doped P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range. For each sensor, the thermally isolated membrane is formed by a process that includes a step of first depositing dielectric thin-film layers over the substrate and then performing a backside etching process on a bulk silicon with TMAH or KOH or carrying out a dry plasma etch until the bottom dielectric thin-film layer is exposed.Type: GrantFiled: September 19, 2006Date of Patent: August 3, 2010Assignee: Siargo, Inc.Inventors: Yahong Yao, Chih-Chang Chen, Gafeng Wang, Liji Huang
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Patent number: 7752910Abstract: A mass flow sensor is supported on an N or P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range.Type: GrantFiled: April 3, 2008Date of Patent: July 13, 2010Assignee: Siargo, Inc.Inventors: Gaofeng Wang, Chih-Chang Chen, Yahong Yao, Liji Huang
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Publication number: 20090164163Abstract: An integrated mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or P-type silicon substrate with orientation <100>. This mass flow sensor comprises an upstream thin-film heater, an downstream thin-film heater, and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heaters and the sensors out of contact with the substrate base. This mass flow sensor is operated with three sets of circuits, a first circuit for measuring a flow rate in a first range of flow rates, a second circuit for measuring a flow rate in a second range of flow rates, and a third circuit in a differential configuration for measuring a flow rate in said first range of flow rates or said second range of flow rates, to significantly increase range of flow rate measurements and provide an optional for concentration measurement, while maintains a high degree of measurement accuracy.Type: ApplicationFiled: September 28, 2007Publication date: June 25, 2009Applicant: SIARGO LTD.Inventors: Gaofeng Wang, Chih-Chang Chen, Yahong Yao, Liji Huang
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Publication number: 20090158859Abstract: The current invention generally relates to Micro Electro Mechanical Systems (MEMS) thermal mass flow sensors for measuring the flow rate of a flowing fluid (gas/liquid) and the methods of manufacturing on single crystal silicon wafers. The said mass flow sensors have self-cleaning capability that is achieved via the modulation of the cavity of which the sensing elements locate on the top of the cavity that is made of a silicon nitride film; alternatively the sensing elements are fabricated on top of a binary silicon nitride/conductive polycrystalline silicon film under which is a porous silicon layer selective formed in a silicon substrate. Using polycrystalline silicon or the sensing elements as electrodes, an acoustic wave can be generated across the porous silicon layer which is also used for the thermal isolation of the sensing elements.Type: ApplicationFiled: December 19, 2007Publication date: June 25, 2009Applicant: SIARGO LTD.Inventors: Liji Huang, Chih-Chang Chen, Yahong Yao, Gaofeng Wang
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Patent number: 7536908Abstract: An integrated mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range. For each sensor, the thermally isolated membrane is formed by a process that includes a step of first depositing dielectric thin-film layers over the substrate and then performing a backside etching process on a bulk silicon with TMAH or KOH or carrying out a dry plasma etch until the bottom dielectric thin-film layer is exposed.Type: GrantFiled: June 21, 2005Date of Patent: May 26, 2009Assignee: Siargo, Ltd.Inventors: Gaofeng Wang, Chih-Chang Chen, Yahong Yao, Liji Huang
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Publication number: 20090016403Abstract: A device with micromachined (a.k.a. MEMS, Micro Electro Mechanical Systems) silicon sensor to measure gas or liquid concentration in a binary mixture formality is disclosed in the present invention. A process for fabricating the said MEMS silicon concentration sensor, which thereby can greatly reduce the sensor fabrication cost by a batch production, is revealed as well. This MEMS process can mass-produce the sensors on silicon substrate in the ways of small size, low power, and high reliability. In addition to the gas or liquid concentration measurement, the present invention further discloses that the said sensor can also readily measure gas or liquid mass flow rate while record the concentration data, which is not viable by other related working principle.Type: ApplicationFiled: July 9, 2007Publication date: January 15, 2009Inventors: Chih-Chang Chen, Yahong Yao, Gaofeng Wang, Liji Huang
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Publication number: 20080271525Abstract: A mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or lightly doped P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range. For each sensor, the thermally isolated membrane is formed by a process that includes a step of first depositing dielectric thin-film layers over the substrate and then performing a backside etching process on a bulk silicon with TMAH or KOH or carrying out a dry plasma etch until the bottom dielectric thin-film layer is exposed.Type: ApplicationFiled: April 3, 2008Publication date: November 6, 2008Inventors: Gaofeng Wang, Chih-Chang Chen, Yahong Yao, Liji Huang
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Publication number: 20070017285Abstract: An integrated mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range. For each sensor, the thermally isolated membrane is formed by a process that includes a step of first depositing dielectric thin-film layers over the substrate and then performing a backside etching process on a bulk silicon with TMAH or KOH or carrying out a dry plasma etch until the bottom dielectric thin-film layer is exposed.Type: ApplicationFiled: June 21, 2005Publication date: January 25, 2007Inventors: Gaofeng Wang, Chih-Chang Chen, Yahong Yao, Liji Huang
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Publication number: 20070011867Abstract: A mass flow sensor is manufactured by a process of carrying out a micro-machining process on an N or lightly doped P-type silicon substrate with orientation <100>. This mass flow sensor comprises a central thin-film heater and a pair of thin-film heat sensing elements, and a thermally isolated membrane for supporting the heater and the sensors out of contact with the substrate base. The mass flow sensor is arranged for integration on a same silicon substrate to form a one-dimensional or two-dimensional array in order to expand the dynamic measurement range. For each sensor, the thermally isolated membrane is formed by a process that includes a step of first depositing dielectric thin-film layers over the substrate and then performing a backside etching process on a bulk silicon with TMAH or KOH or carrying out a dry plasma etch until the bottom dielectric thin-film layer is exposed.Type: ApplicationFiled: September 19, 2006Publication date: January 18, 2007Inventors: Yahong Yao, Chih-Chang Chen, Gafeng Wang, Liji Huang