1 / 17

Hot Embossing Microfabrication

Hot Embossing Microfabrication. Hot Embossing is a technique of imprinting microstructures on a substrate (polymer) using a master mold (silicon tool). Cool the substrate and mold to just below T g. De-embossing of the mold and substrate. Master/Mold from Femto- Second Laser.

robertascott
Download Presentation

Hot Embossing Microfabrication

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Hot Embossing Microfabrication Hot Embossing is a technique of imprinting microstructures on a substrate (polymer) using a master mold (silicon tool).

  2. Cool the substrate and mold to just below Tg De-embossing of the mold and substrate Master/Mold from Femto- Second Laser Heat the substrate and mold to just above Tg of the substrate Apply embossing force on the substrate via the mold under vacuum Steps in Hot Embossing • Heating Silicon & Polymer above glass transition temperature (Tg). • Applying load by pressing the silicon tool on polymer at certain embossing pressure. • Cooling the silicon tool and polymer assembly below Tg and de-embossing the tool.

  3. Advantages of Hot Embossing System • Cost effective – Easy manufacturability. • Time efficient – Fast process. • Fabrication ofhigh aspect ratio features. • Bio-Compatible surfaces – Polymer substrates used. • Disposable – Low cost for volume production.

  4. Applications of Hot Embossing • BioMEMS/Bio-Sensors • Micro-Fluidic Devices • Micro-Optics • m-TAS (Micro Total Analysis Systems)

  5. Hot Embossing v/s Other MEMS Fabrication Processes

  6. Product Comparison

  7. Schematic Representation of Hot Embossing Setup

  8. Hot Embossing Conceptual Solid Models

  9. Parametric study to determine number of cartridges Parametric study to determine heating block thickness Heating Subsystem: Thermal Analysis • Heating block dimensions and number of cartridges found by a parametric study. • 53 heating cartridges (1 kW, Ø 1/2”, 10” long) on each heating block of 10” (L) x 10.5 (B) x 4” (H).

  10. Heating Subsystem: Thermal Analysis (Cont..) • Appropriate zone configuration of heating cartridges for • optimal heating time, • prevention of hot spots, and • uniform heating on mold and substrate surfaces. • 5 heating zones per heating block having different heating power/heat flux.

  11. Heating Subsystem: Thermal Analysis (Cont..) • Zone Configuration obtained using iterative transient FEM thermal analysis in ANSYS. • Transient behavior of heating cartridges also taken into account.

  12. Forcing Subsystem: Structural Analysis • Forcing System used to provide embossing force. • Forcing provided by a Dual Column Floor Mounted Frame material testing system by Instron Corporation model 5800. • Thermal solution incorporated for FEM structural analysis. • Material modeling incorporates Young’s modulus and Poisson’s ratio variation with temperature.

  13. Forcing Subsystem: Structural Analysis (Cont..) • 1/4th model used for finite element analysis due to symmetry. Displacement contour plot from structural analysis

  14. Cooling Subsystem • 15 Ton (52.76 kW) chiller and Temperature Controller used to cool the system within 2 minutes. • Cooling plates divided into 5 zones (5 inputs, 5 outputs) to obtain • uniform temperature distribution on the mold and substrate surfaces. • optimize cooling time. • Manifolds and flow-meters used to evenly distribute the cooling oil into the cooling plates.

  15. Mini-Vacuum Chamber • Mini vacuum chamber used to provide a clean and moisture free environment during embossing. • Mini vacuum chamber can accommodate an 8” substrate.

  16. Control Subsystem • Compact Fieldpoint system and LabVIEW by National Instruments used for data acquisition and control of the main system and individual sub-system.

  17. Control Subsystem (Cont..) • LabVIEW is used to: • Monitor • the chiller set-points, • the temperature across the master and the substrate, • the pressure in the vacuum chamber. • Control • the motion (displacement and velocity) of the embossing machine, • the flow of the cooling oil through the cooling block, • the current through the heater cartridges • relief valve of the vacuum chamber.

More Related