Field emission type backlight unit and method of manufacturing upper panel thereof

Abstract

A method of manufacturing an upper panel of a field emission type backlight unit. The method includes: sequentially forming an anode electrode and a phosphor layer on a substrate; forming a metal reflection film on the phosphor layer; and annealing a surface of the metal reflection film. The method can increase brightness of an image, can prevent occurrence of an electric arc when a high driving voltage is applied to the backlight unit, and allows removal of residues produced when manufacturing the backlight unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

FIG. 1 is a cross-sectional view of a contemporary field emission type backlight unit;

FIGS. 2A through 2D are cross-sectional views showing a method for manufacturing an upper panel of a backlight unit as an embodiment of the principles of the present invention;

FIGS. 3A and 3B are cross-sectional views illustrating a backlight unit constructed as an embodiment of the principles of the present invention;

FIG. 4 is a graph showing a brightness characteristic varying according to the thickness of a metal reflection film of the upper panel of a backlight unit manufactured according to the method of FIGS. 2A and 2B;

FIGS. 5A and 5B are photographs showing a morphology of the metal reflection film when a surface annealing process of FIG. 2C is omitted while manufacturing an upper panel of a backlight unit as an embodiment of the present invention; and

FIGS. 6A and 6B are photographs showing morphologies of the metal reflection film of an upper panel of a backlight unit manufactured using the method illustrated by FIGS. 2A through 2C.

Claims

1. A method of manufacturing an upper panel of a field emission type backlight unit, the method comprising: sequentially forming an anode electrode and a phosphor layer on a substrate;forming a metal reflection film on the phosphor layer; andannealing the metal reflection film.

2. The method of claim 1, comprised of annealing the metal reflection film at a temperature lower than a softening point of a material for forming the metal reflection film.

3. The method of claim 2, with the metal reflection film made from Al, comprised of annealing the Al reflection film while maintaining the temperature of the Al reflection film within a range between approximately 500° C. to 600° C.

4. The method of claim 1, comprised of annealing the surface of the metal reflection film with one of a laser irradiation method and a rapid thermal annealing (RTA) method.

5. The method of claim 4, with the laser comprising a continuous wave laser.

6. The method of claim 1, further comprised of, between sequential formation of the anode electrode and the phosphor layer on the substrate and formation of the metal reflection film on the phosphor layer, forming a decomposable film that creates an air gap between the phosphor layer and the metal reflection film and that planarizes the metal reflection film.

7. The method of claim 6, further comprising, between sequential formation of the anode electrode and the phosphor layer on the substrate and formation of the metal reflection film on the phosphor layer, forming a prewet solution that further planarizes the metal reflection film before forming the decomposable film.

8. The method of claim 1, further comprising, between formation of the metal reflection film on the phosphor layer and annealing of the surface of the metal reflection film, thermally decomposing the decomposable film by increasing the temperature of the film, creating air gaps in the metal reflection film, and exhausting a gas resulting from thermally decomposition of the decomposable film through the air gaps.

9. A field emission type backlight unit, comprising: an upper substrate and a lower substrate facing each other and spaced apart from each other;an anode electrode formed on a lower surface of the upper substrate;a phosphor layer formed on a lower surface of the anode electrode;a metal reflection film formed on a lower surface of the phosphor layer and planarized by annealing;a plurality of cathode electrodes and gate electrodes alternately formed on an upper surface of the lower substrate; andan emitter formed at least on the cathode electrode of the cathode electrode and the gate electrode.

10. The field emission type backlight unit of claim 9, further comprising a decomposable film disposed between the phosphor layer and the metal reflection film, that creates air gaps between the phosphor layer and the metal reflection film and planarizes the metal reflection film.

11. The field emission type backlight unit of claim 10, further comprising a prewet solution disposed between the phosphor layer and the decomposable film, that further planarizes the metal reflection film.

12. The field emission type backlight unit of claim 9, with the metal reflection film being comprised of Al.

13. The field emission type backlight unit of claim 9, with the emitter being formed from carbon nanotubes.

14. A field emission type backlight unit, comprising: an upper substrate and a lower substrate facing each other and spaced apart from each other;an anode electrode formed on a lower surface of the upper substrate;a phosphor layer formed on a lower surface of the anode electrode;a metal reflection film formed on a lower surface of the phosphor layer and planarized by annealing;a cathode electrode formed on an upper surface of the lower substrate;an insulating layer that is formed on the upper surface of the lower substrate and has a cavity that exposes the cathode electrode;a gate electrode that is formed on the insulating layer and has a gate hole corresponding to the cavity in the insulating layer; andan emitter formed on the cathode electrode.

15. The field emission type backlight unit of claim 14, further comprising a decomposable film disposed between the phosphor layer and the metal reflection film, that creates air gaps between the phosphor layer and the metal reflection film and planarizes the metal reflection film.

16. The field emission type backlight unit of claim 15, further comprising a prewet solution disposed between the phosphor layer and the decomposable film, that further planarizes the metal reflection film.

17. The field emission type backlight unit of claim 14, with the metal reflection film being comprised of Al.

18. The field emission type backlight unit of claim 14, with the emitter being formed from carbon nanotubes.

19. The method of claim 1, with the substrate comprising a glass substrate.

20. The method of claim 1, with the anode electrode comprising indium tin oxide (ITO).

21. The method of claim 6, with the decomposable film being formed by mixing at least two materials selected from a group consisting essentially of butyl methacrylate (BMA), acryloide, toluene, methyl isobutyl ketone (M.I.B.K), methyl ethyl ketone (M.E.K), ethyl acetate, iso-amyl acetate, dibutyl phthalate and nitro cellulose.

22. The method of claim 7, with the prewet solution being formed of at least one material selected from a group consisting essentially of polyvinyl alcohol (PVA), colloidal silica, triton and acetic acid.

23. The field emission type backlight unit of claim 9, comprising said emitter being formed on a side of the cathode.

24. The field emission type backlight unit of claim 9, comprising said emitter being formed on a top of the cathode.

25. The field emission type backlight unit of claim 9, comprising said emitter being formed on a side of the cathode and on a side of the gate electrode.

26. The field emission type backlight unit of claim 9, comprising said emitter being formed on a top of the cathode and on a top of the gate electrode.