Patterned phosphors in through hole via (THV) glass

• US 9,627,437 B1
• Filed: 06/30/2016
• Issued: 04/18/2017
• Est. Priority Date: 06/30/2016
• Status: Active Grant

• Current Assignee: Elux Inc.
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ulmer, Kurt Michael, Schuele, Paul John
• Primary Examiner(s): Ho, Tu-Tu
• Application Number:
  US15/199,923
• Time in Patent Office: 292 Days
• Field of Search: 257 89
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

Embodiments are related generally to display fabrication, and more particularly to a fluidic assembly process for the placement of light emitting diodes on a transparent display substrate.

Claims

1. A direct-emission display panel comprising:

a substrate with a top surface and a bottom surface, wherein the substrate includes a plurality of through-hole vias (THVs) aligned in a plurality of parallel rows, wherein each THV exhibits a first diameter;

a color phosphor material filling a first subset of the plurality of THVs;

a film overlying the top surface of the substrate, wherein the film includes a plurality of wells, wherein each well of the plurality of wells is aligned in a row and exposes a corresponding one of the plurality of THVs, and wherein each well exhibits a second diameter that is greater than the first diameter; and

a plurality of light emitting diode (LED) disks, wherein a respective one of the plurality of LED disks is situated in each well of the plurality of wells, wherein each LED disk of the plurality of LED disks exhibits a disk diameter that is both greater than the first diameter and less than the second diameter.

2. The panel of claim 1, wherein each LED disk of the plurality of LED disks is configured to emit a common first color.

3. The panel of claim 2, wherein the panel is organized into pixel sections with each pixel section including (n) THVs;

wherein n is an integer;

wherein (n−

1) unique color phosphor materials fill corresponding THVs in each pixel section;

wherein each of the (n−

1) color phosphor materials is respectively configured to pass a different color; and

wherein the panel further comprises;

a first color filter formed on a surface of the substrate and configured to block the first color, wherein the first color filter overlies the (n−

1) THVs in each pixel section.

4. The panel of claim 3, wherein the (n−

1) color phosphor materials are each configured to pass a color different than the first color.

5. The panel of claim 1, wherein the substrate further comprises a plurality of bottom electrically conductive traces, with each bottom conductive trace associated with a corresponding row of THVs, and connected to a bottom contact of each LED disk in the row.

6. The panel of claim 5, wherein the film has a first thickness and the LED disks have about the same first thickness;

the panel further comprising;

a plurality of top electrically conductive traces, with each top electrically conductive trace associated with a corresponding column of THVs, and connected to a top contact of each LED disk in the column.

7. The panel of claim 1, wherein the THVs have tapered sidewalls with a diameter increasing in size from the substrate top surface to the substrate bottom surface.

8. The panel of claim 7, wherein the tapered sidewalls of the THVs are coated with a reflective material.

9. A method for forming a fluidic assembly direct-emission display panel, the method comprising:

providing a substrate with a top surface and a bottom surface;

forming through-hole vias (THVs) in the substrate aligned in a plurality of parallel rows, each THV having a first diameter;

forming a film overlying the substrate top surface;

forming a plurality of wells in the film, each well having a second diameter greater than the first diameter, and aligned in a row exposing a corresponding THV;

flowing an ink comprising a solvent and a plurality of light emitting diode (LED) disks overlying the film, where each LED disk has a disk diameter greater than the first diameter and less than the second diameter;

capturing the LED disks in the wells; and

,

filling a first plurality of the THVs with a color phosphor material.

10. The method of claim 9 wherein flowing the ink includes flowing the ink comprising LED disks capable of emitting a common first color.

11. The method of claim 10 wherein providing the substrate includes providing the substrate organized into pixel sections, where each pixel section includes a plurality of (n) THVs;

wherein filling with the color phosphor material includes filling corresponding THVs in each pixel section with (n−

1) unique color phosphors respectively capable of passing (n−

1) unique colors; and

,

the method further comprising;

forming a first color filter, capable of blocking the first color, overlying the (n−

1) THVs in each pixel section, on the substrate bottom surface.

12. The method of claim 11 wherein filling corresponding THVs with (n−

1) unique color phosphors includes filling with color phosphor materials each passing a unique color other than the first color.

13. The method of claim 9 wherein forming the THVs includes forming THVs having tapered sidewalls with a diameter increasing in size from the substrate top surface to the substrate bottom surface.

14. The method of claim 13 further comprising:

subsequent to forming the THVs, coating the THVs sidewalls with a reflective material.

15. A direct-emission display panel comprising:

a display backplane with a top surface;

a plurality of light emitting diode (LED) disks overlying the backplane top surface arranged in pixel sections each comprising a plurality of LED disks, where each LED disk is capable of emitting a common first color;

a first transparent substrate overlying the backplane top surface with a through-hole via (THV) overlying a first LED disk in each pixel section;

a color phosphor material formed in the THVs in the first transparent substrate, capable of passing a second color, different than the first color; and

,

a first color filter, capable of blocking the first color, overlying the THVs in the first transparent substrate.

16. The panel of claim 15 wherein each pixel section comprises (n) LED disks;

the panel further comprising;

(n−

2) transparent substrates stacked overlying the first transparent substrate, each of the (n−

2) transparent substrates with THVs overlying a unique LED disk in each pixel section; and

,

(n−

2) color phosphor materials respectively formed in the THVs of the (n−

2) transparent substrates, each of the (n−

2) color phosphor materials capable of passing a unique color different than the first color and the second color.

17. The panel of claim 15 wherein the THVs in the first transparent substrate have tapered sidewalls, with a diameter narrowing from a top surface of the first transparent substrate to a bottom surface of the first transparent substrate overlying the backplane top surface.

18. The panel of claim 17 further comprising:

a reflective material lining the THVs in the substrate.

19. A method for forming a direct-emission display panel comprising:

providing a display backplane with a top surface;

forming a plurality of light emitting diode (LED) disks overlying the backplane top surface arranged in pixel sections each comprising a plurality of LED disks, where each LED disk is capable of emitting a common first color;

forming a first transparent substrate;

forming through-hole vias (THVs) in the first transparent substrate, to overlie a first LED disk in each pixel section;

forming a color phosphor material in the THVs in the first transparent substrate, capable of passing a second color, different than the first color;

forming a first color filter, capable of blocking the first color, overlying the THVs in the first transparent substrate; and

,

stacking the first transparent substrate overlying the display backplane top surface.

20. The method panel of claim 19 wherein forming the LED disks overlying the backplane includes arranging each pixel section to comprise (n) LED disks;

the panel further comprising;

forming (n−

2) transparent substrates;

forming THVs in the (n−

2) transparent substrates to respectively overlie a unique LED disk in each pixel section;

forming (n−

2) unique color phosphor materials, respectively, in the THVs of the (n−

2) transparent substrates, capable of passing (n−

2) unique colors different than the first color and the second color;

forming a first color filter overlying the THVs in the (n−

2) transparent substrates; and

,

stacking the (n−

2) transparent substrates overlying the first transparent substrate.

21. The method of claim 19 wherein forming the THVs in the first transparent substrate includes forming tapered sidewalls in the THVs, with diameters narrowing from a top surface of the substrate to a bottom surface of the substrate overlying the backplane.

22. The method of claim 21 further comprising:

lining the THVs in the substrate with a reflective material.