Method and device for packaging a substrate
View Patent ↗A package structure and method of packaging for an interferometric modulator. A thin film material is deposited over an interferometric modulator and transparent substrate to encapsulate the interferometric modulator. A gap or cavity between the interferometric modulator and the thin film provides a space in which mechanical parts of the interferometric modulator may move. The gap is created by removal of a sacrificial layer that is deposited over the interferometric modulator.
1. A method of manufacturing a display, the method comprising:
providing an electro-mechanical device, wherein said electro-mechanical device comprises a first sacrificial layer;
depositing a second sacrificial layer over said electro-mechanical device, wherein said second sacrificial layer is exposed to a portion of said first sacrificial layer;
depositing a thin film backplane over and in contact with said second sacrificial layer, wherein the thin film backplane has an opening; and
after depositing the thin film backplane, removing said first and said second sacrificial layers,
wherein at least a part of said first sacrificial layer is removed concurrently with at least a part of said second sacrificial layer,
wherein removing said second sacrificial layer provides a gap above said electro-mechanical device and below said thin film backplane.
2. The method of claim 1 , wherein said electro-mechanical device comprises an interferometric modulator.
3. The method of claim 2 , wherein said first sacrificial layer is disposed in an optical cavity of said interferometric modulator.
4. The method of claim 1 , wherein said electro-mechanical device comprises an array of moveable mirrors configured to interferometrically modulate light.
5. The method of claim 1 , wherein all of said first and all of said second sacrificial layers are removed at the same time.
6. The method of claim 1 , wherein said thin film backplane comprises a hermetic material.
7. The method of claim 1 , wherein said first sacrificial layer or said second sacrificial layer is formed of molybdenum, silicon, tungsten, or titanium.
8. The method of claim 1 , wherein said first sacrificial layer or said second sacrificial layer is removed with xenon diflouride.
9. The method of claim 1 further comprising depositing an overcoat layer over said thin film backplane.
10. The method of claim 1 , wherein said electro-mechanical device comprises a microelectromechanical systems device.
11. A method of manufacturing a display comprising a plurality of electro-mechanical devices, the method comprising:
providing an electro-mechanical device, wherein said electro-mechanical device comprises:
a first sacrificial layer; and
a first opening into said electro-mechanical device exposing said sacrificial layer;
providing a thin film backplane over said electro-mechanical device, wherein the thin film backplane comprises a second opening;
providing a second sacrificial layer between said thin film backplane and said electro-mechanical device;
introducing a release material through said first and second openings to release the first sacrificial layer and second sacrificial layer, and
wherein at least a part of said first sacrificial layer is removed concurrently with at least a part of said second sacrificial layer.
12. The method of claim 11 , wherein all of said first sacrificial layer and all of said second sacrificial layer are removed at the same time.
13. The method of claim 11 , wherein said release material is xenon diflouride.
14. The method of claim 11 , wherein said electro-mechanical device comprises an interferometric modulator.
15. The method of claim 11 , wherein said electro-mechanical device comprises an array of moveable mirrors configured to interferometrically modulate light.
16. The method of claim 11 , wherein said electro-mechanical device comprises a microelectromechanical systems device.
17. A display device, comprising:
a transparent substrate;
an interferometric modulator disposed on the transparent substrate, said interferometric modulator comprising:
a first sacrificial layer; and
a first opening exposing said first sacrificial layer; and
a thin film backplane sealing said interferometric modulator within a package between said transparent substrate and said thin film backplane,
wherein a second sacrificial layer is positioned between said thin film backplane and said interferometric modulator and contacts said first sacrificial layer exposed at said first opening, and
wherein a second opening exists in said thin film backplane.
18. The method of claim 1 , wherein said second sacrificial layer is deposited to a thickness in the range of about 1000 Å to about 5000 Å.
19. The method of claim 1 , wherein said thin film is about 1 μm thick.
20. The method of claim 2 , wherein said interferometric modulator comprises a layer of indium tin oxide of about 500 Å thick.