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Application of Micro fabricated valves based on the principles of thermo pneumatic actuation

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Greeshma S

1) The document discusses thermopneumatic microvalves and their applications. It describes the fabrication process and working of thermopneumatic microvalves. 2) Applications discussed include use as expansion valves in refrigeration systems and for gas distribution and control in semiconductor processing. 3) The advantages of microvalves include increased performance, higher integration levels, decreased size and increased reliability compared to traditional valves. Challenges include required power, response speed and effects of shrinking size.

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M. S. Ramaiah School of Advanced Studies 1 M. Sc. (Engg.) in Electronics System Design Engineering GREESHMA S CWB0913004 , FT-2013 4thModule Presentation Module code : ESE2513Module name : Low Voltage ElectronicsModule leader: Ms. Nireeksha/ Ms. Malathi Presentation on : 14/02/2014
M. S. Ramaiah School of Advanced Studies 2 Application of Micro fabricated valves based on the principles of thermo pneumatic actuation Presentation on
M. S. Ramaiah School of Advanced Studies 3 •ABSTRACT •INTRODUCTION •THERMOPNEUMATICMICROVALVETECHNOLOGY •REFRIGERATIONAPPLICATION •SEMICONDUCTORPROCESSAPPLICATION •MASSFLOWMEASUREMENTPRINCIPLE •ADVANTAGES •DISADVANTAGES •CONCLUSION •REFERENCES Overview
M. S. Ramaiah School of Advanced Studies 4 Abstract Intermsofcontrolanddistributionofliquidsandgases(microfluidics),MEMS- baseddevicesoffersopportunitiestoachieveincreasedperformanceandhigherlevelsoffunctionalintegration,atlowercost,withdecreasedsizeandincreasedreliability Microfluidicactuatorsincludedistributionmicrochannelsandorifices,microvalves, micropumps,andmicrocompressors Relatedmicrosensorsarerequiredtomeasuretemperature,flow,pressure, viscosity,anddensity Abriefcomparisontootheractuationtechniquesismade,scienceandtechnologyofsilicon-basedthermopneumaticmicrovalves Expansionvalvesforrefrigerationcontrol
M. S. Ramaiah School of Advanced Studies 5Introduction Actuatorssuchaspumps,compressors,andvalvesareusedtoalterthestateofthefluidpressure,temperature,orflow MicrofabricationtechniquescreatedforthesemiconductorintegratedcircuitindustryhavefoundnewapplicationsinMEMSresearch,developmentandmanufacture Microvalvesareaprimarycomponentofmicrofluidicsystems Actuatorsrelyonavarietyofactivationmechanism,suchaselectromagnetic, electrostatic,pneumatic,bimetallicalloys,shape-memoryalloys(SMA),electro- chemicalandthermopnematic Distributionchannels,suchasorificesandmicrochannels,carrythefluidfromoneportionofthesystemtoanother
M. S. Ramaiah School of Advanced Studies 6Thermopneumatic Microvalve TechnologyFigure1CrosssectionofaThermopneumaticallyActuatedMicrovalve Figure2DrillholesinPyrex Waferultrasonically Figure3MetalizePyrexwafer Figure4DefinemembraneLithographically(goldoxides, Photo-resistmasks) Figure5EtchmembranewaferinKOH;stripmaskingmaterialsFigure6Defineorificewaferlithographically Figure7Etchorificewaferin KOH Figure8Fabricationsequencefora normallyopen,thermopneumatic valves
M. S. Ramaiah School of Advanced Studies 7 Thermopneumatic Microvalve Technology Figure 9 Estimated flow based on loss coefficient flow measurements Figure 10 Relationship between the equilibrium membrane to inlet Figure 11 Predicted effect of scaling on microvalve responsetime
M. S. Ramaiah School of Advanced Studies 8Refrigeration Application Normally-open microvalves have been applied to the problem of controlling liquid flow Refrigerant liquids present unusual challenges for thermally activated microvalves The pressure versus flow versus valve power input for one such microvalve is shown Figure 12 Pressure vs. R-13a flow vs. pressure for a representative microvalve
M. S. Ramaiah School of Advanced Studies 9 Semiconductor process Applications The present and future requirements of the semiconductor industry for gas distribution and control The thermopnematic actuation principle is employedFigure 13 Cross section of thermo pneumaticallyactuated , normally closed, low leakage shut offvalve The silicon-ceramic interface is a eutectic bond The overall dimension are 8mm X 6mm X 2mm, and are roughly scale
M. S. Ramaiah School of Advanced Studies 10Mass flow Measurement principleFigure 14 Schematic of O-ring used in the vacuum ring rate shutoff valve Figure 15 Helium leak rate for vacuum leak-rate for Microvalves Figure 16 Schematic representation of the low- flow MFC Figure 17 Pressure Sensor Resolution Required to achieve a given flow resolution, as a Function of criticalorifice Hydraulic Diameter
M. S. Ramaiah School of Advanced Studies 11Mass flow Measurement principleFigure 18 Schematic representation of the compressible flow model for the series combination of normally-open proportional valve, and a critical orifice. Figure 19 Measured Flow Characteristics for a Low-FlowMFCFigure 20 Measured flow from a 10 sccm Mass- flow controller Figure 21 Measurement precision results from a 10 sccm mass-flow controller
M. S. Ramaiah School of Advanced Studies 12 Mass flow Measurement principleFigure 22 Measurement reproducibility results from a 10 sccm Mass-Flow controllerFigure 23 Flow model for the MFC Figure 24 Example Isometric View of a Pressureregulator, MFC, or shut-off valve. Figure 25 Isometric View of a 4-Channel Gas stick
M. S. Ramaiah School of Advanced Studies 13Mass flow Measurement principle Figure 26 Schematic of One Channel of an Integrated Gas Stick Figure 27 Size Comparison of Resent and Future Integrated Gas Sticks/panels
M. S. Ramaiah School of Advanced Studies 14Advantages Increasedperformance Higherlevelsoffunctionalintegration HigherResolution Decreasedsize IncreasedreliabilityDisadvantages Thepowerrequiredforactuation Responsespeed Theeffectofshrinkingsize Structuralparameters Choiceofthermopneumaticliquid
M. S. Ramaiah School of Advanced Studies 15Conclusion The science and technology required to design and fabricate flow distribution and control devices suitable for semiconductor processing industry Components such as pressure-based flow models, critical orifices, pressure temperature sensors normally-closed vacuum leak rate shut off valves, have developed These components are combined at higher level into integrated gas panels which has benefit of smaller size, lower cost, higher resolution , materials compatibility and lower defect generation which are among the attributes of the successful application of MEMS-based technology
M. S. Ramaiah School of Advanced Studies 16References Elisabeth verpoorte and nicof.de.rooij,fellow, (2003). Microfluidics Meets MEMS. 6th ed. Switzerland: University of Neuchâtel. 930-953 Albert K. Henning (1998).Microfluidic MEMS. CA: -. 471-486
M. S. Ramaiah School of Advanced Studies 17

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Application of Micro fabricated valves based on the principles of thermo pneumatic actuation

  • 1. M. S. Ramaiah School of Advanced Studies 1 M. Sc. (Engg.) in Electronics System Design Engineering GREESHMA S CWB0913004 , FT-2013 4thModule Presentation Module code : ESE2513Module name : Low Voltage ElectronicsModule leader: Ms. Nireeksha/ Ms. Malathi Presentation on : 14/02/2014
  • 2. M. S. Ramaiah School of Advanced Studies 2 Application of Micro fabricated valves based on the principles of thermo pneumatic actuation Presentation on
  • 3. M. S. Ramaiah School of Advanced Studies 3 •ABSTRACT •INTRODUCTION •THERMOPNEUMATICMICROVALVETECHNOLOGY •REFRIGERATIONAPPLICATION •SEMICONDUCTORPROCESSAPPLICATION •MASSFLOWMEASUREMENTPRINCIPLE •ADVANTAGES •DISADVANTAGES •CONCLUSION •REFERENCES Overview
  • 4. M. S. Ramaiah School of Advanced Studies 4 Abstract Intermsofcontrolanddistributionofliquidsandgases(microfluidics),MEMS- baseddevicesoffersopportunitiestoachieveincreasedperformanceandhigherlevelsoffunctionalintegration,atlowercost,withdecreasedsizeandincreasedreliability Microfluidicactuatorsincludedistributionmicrochannelsandorifices,microvalves, micropumps,andmicrocompressors Relatedmicrosensorsarerequiredtomeasuretemperature,flow,pressure, viscosity,anddensity Abriefcomparisontootheractuationtechniquesismade,scienceandtechnologyofsilicon-basedthermopneumaticmicrovalves Expansionvalvesforrefrigerationcontrol
  • 5. M. S. Ramaiah School of Advanced Studies 5Introduction Actuatorssuchaspumps,compressors,andvalvesareusedtoalterthestateofthefluidpressure,temperature,orflow MicrofabricationtechniquescreatedforthesemiconductorintegratedcircuitindustryhavefoundnewapplicationsinMEMSresearch,developmentandmanufacture Microvalvesareaprimarycomponentofmicrofluidicsystems Actuatorsrelyonavarietyofactivationmechanism,suchaselectromagnetic, electrostatic,pneumatic,bimetallicalloys,shape-memoryalloys(SMA),electro- chemicalandthermopnematic Distributionchannels,suchasorificesandmicrochannels,carrythefluidfromoneportionofthesystemtoanother
  • 6. M. S. Ramaiah School of Advanced Studies 6Thermopneumatic Microvalve TechnologyFigure1CrosssectionofaThermopneumaticallyActuatedMicrovalve Figure2DrillholesinPyrex Waferultrasonically Figure3MetalizePyrexwafer Figure4DefinemembraneLithographically(goldoxides, Photo-resistmasks) Figure5EtchmembranewaferinKOH;stripmaskingmaterialsFigure6Defineorificewaferlithographically Figure7Etchorificewaferin KOH Figure8Fabricationsequencefora normallyopen,thermopneumatic valves
  • 7. M. S. Ramaiah School of Advanced Studies 7 Thermopneumatic Microvalve Technology Figure 9 Estimated flow based on loss coefficient flow measurements Figure 10 Relationship between the equilibrium membrane to inlet Figure 11 Predicted effect of scaling on microvalve responsetime
  • 8. M. S. Ramaiah School of Advanced Studies 8Refrigeration Application Normally-open microvalves have been applied to the problem of controlling liquid flow Refrigerant liquids present unusual challenges for thermally activated microvalves The pressure versus flow versus valve power input for one such microvalve is shown Figure 12 Pressure vs. R-13a flow vs. pressure for a representative microvalve
  • 9. M. S. Ramaiah School of Advanced Studies 9 Semiconductor process Applications The present and future requirements of the semiconductor industry for gas distribution and control The thermopnematic actuation principle is employedFigure 13 Cross section of thermo pneumaticallyactuated , normally closed, low leakage shut offvalve The silicon-ceramic interface is a eutectic bond The overall dimension are 8mm X 6mm X 2mm, and are roughly scale
  • 10. M. S. Ramaiah School of Advanced Studies 10Mass flow Measurement principleFigure 14 Schematic of O-ring used in the vacuum ring rate shutoff valve Figure 15 Helium leak rate for vacuum leak-rate for Microvalves Figure 16 Schematic representation of the low- flow MFC Figure 17 Pressure Sensor Resolution Required to achieve a given flow resolution, as a Function of criticalorifice Hydraulic Diameter
  • 11. M. S. Ramaiah School of Advanced Studies 11Mass flow Measurement principleFigure 18 Schematic representation of the compressible flow model for the series combination of normally-open proportional valve, and a critical orifice. Figure 19 Measured Flow Characteristics for a Low-FlowMFCFigure 20 Measured flow from a 10 sccm Mass- flow controller Figure 21 Measurement precision results from a 10 sccm mass-flow controller
  • 12. M. S. Ramaiah School of Advanced Studies 12 Mass flow Measurement principleFigure 22 Measurement reproducibility results from a 10 sccm Mass-Flow controllerFigure 23 Flow model for the MFC Figure 24 Example Isometric View of a Pressureregulator, MFC, or shut-off valve. Figure 25 Isometric View of a 4-Channel Gas stick
  • 13. M. S. Ramaiah School of Advanced Studies 13Mass flow Measurement principle Figure 26 Schematic of One Channel of an Integrated Gas Stick Figure 27 Size Comparison of Resent and Future Integrated Gas Sticks/panels
  • 14. M. S. Ramaiah School of Advanced Studies 14Advantages Increasedperformance Higherlevelsoffunctionalintegration HigherResolution Decreasedsize IncreasedreliabilityDisadvantages Thepowerrequiredforactuation Responsespeed Theeffectofshrinkingsize Structuralparameters Choiceofthermopneumaticliquid
  • 15. M. S. Ramaiah School of Advanced Studies 15Conclusion The science and technology required to design and fabricate flow distribution and control devices suitable for semiconductor processing industry Components such as pressure-based flow models, critical orifices, pressure temperature sensors normally-closed vacuum leak rate shut off valves, have developed These components are combined at higher level into integrated gas panels which has benefit of smaller size, lower cost, higher resolution , materials compatibility and lower defect generation which are among the attributes of the successful application of MEMS-based technology
  • 16. M. S. Ramaiah School of Advanced Studies 16References Elisabeth verpoorte and nicof.de.rooij,fellow, (2003). Microfluidics Meets MEMS. 6th ed. Switzerland: University of Neuchâtel. 930-953 Albert K. Henning (1998).Microfluidic MEMS. CA: -. 471-486
  • 17. M. S. Ramaiah School of Advanced Studies 17