1. Presentation Short Title
Engr 1182 Nano Pre-Lab
Chip Lid Molding
Rev: 20XXMMDD, Initials
Presentation Short Title

2. Presentation Short Title
Micro-fabrication
How can we produce devices on a very small scale ?
E.g Device dimensions 10 nm – 400 µm
Answer: Two ways
Top – Down
conventional manufacturing approaches at a reduced scale, such as CNC milling and photolithography
Bottom – Up
controlling molecular-level interactions to create substances with the required properties
Reference: Nick Ferrell
P. 2
Rev: 20XXMMDD, Initials
Presentation Short Title

3. Evolution of Top – Down Micro-fabrication
Originally developed by microelectronics silicon industry
Refined for nanoscale fabrication
Extended to polymer micro/nanofabrication
polymers are flexible and bio-compatible
Rev: 20XXMMDD, Initials
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4. Presentation Short Title
Photolithography
Photolithography is a common micro-fabrication technique used to transfer an image from a photomask to the surface of a substrate by using ultraviolet light.
The components needed for Photolithography are light source, photomask, lens and wafer.
Rev: 20XXMMDD, Initials
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5. Presentation Short Title
LOC fabrication
For this LOC project chips will be produced in a three step process.
First, each team creates a CAD file of their LOC design.
Second, acrylic wafers are milled with a CNC machine from the CAD design.
Third, we will mold plain lids (no pattern) to enclose the channels and wells of the acrylic wafer.
Rev: 20XXMMDD, Initials
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6. Presentation Short Title
Molding
LOC wells and channels will be sealed with a flexible lid.
In order to mold our LOC lids, we mix PDMS (silicone rubber) resin with its hardener(catalyst) in a disposable cup by stirring rigorously.
This mixing creates a lot of bubbles and we need to get rid of those bubbles since we do not want any optical defects in our molds.
Rev: 20XXMMDD, Initials
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7. Presentation Short Title
Degassing Liquids
We get rid of those bubbles by pulling a vacuum on solution.
Lower pressure expands bubbles by increasing the volume of the gas
Lower pressure reduces the solubility of air in the liquid thus causing bubbles to surface.
Cycling vacuum and atmospheric pressure creates a driving force to remove bubbles from the liquid phase and have a defect free mold.
Rev: 20XXMMDD, Initials
Presentation Short Title