Light active sheet and methods for making the same

• US 7,052,924 B2
• Filed: 08/17/2004
• Issued: 05/30/2006
• Est. Priority Date: 03/29/2004
• Status: Active Grant

• Current Assignee: Grote Industries LLC (Grote Industries Incorporated)
• Original Assignee: Articulated Technologies, LLC
• Inventors: Nelson, Gregory Victor, Daniels, John James
• Primary Examiner(s): Dang, Phuc T.
• Application Number:
  US10/919,830
• Publication Number:
  US 20050214962A1
• Time in Patent Office: 651 Days
• Field of Search: 438/22, 438/46, 438/455, 438/604
• US Class Current: 438/22
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• 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

A method for making a sheet of light active material. A first substrate is provided having a transparent first conductive layer. A pattern of light active semiconductor elements are formed. The pattern of light active semiconductor elements may be formed using an electrostatic attraction and transferring process. The light active semiconductor elements have an n-side and a p-side. Each light active semiconductor element has either of the n-side or the p-side in electrical communication with the transparent conductive layer. A second substrate having a second conductive layer is provided. The second substrate is secured to the first substrate so that the other of said n-side or said p-side of each said light active semiconductor element in electrical communication with the second conductive layer. Thus, a solid-state sheet of light active material is formed.

Claims

1. A method for forming a sheet of light active material, comprising the steps of:

Providing a first substrate having a transparent first conductive layer, the transparent first conductive layer comprising a transparent coating preformed on the first substrate;

Forming a pattern of light active semiconductor element, the light active semiconductor elements having an n-side and a p-side, each said light active semiconductor element having either of said n-side or said p-side in electrical communication with the transparent conductive layer;

Providing a second substrate having a second conductive layer;

Securing the second substrate to the first substrate, the other of said n-side or said p-side of each said light active semiconductor element in electrical communication with the second conductive layer to form a light active device.

2. A method of forming a sheet of light active material according to claim 1;

wherein the transparent coating is applied as at least one of a conductive ink, conductive pattern and conductive adhesive.

3. A method of forming a sheet of light active material according to claim 1;

wherein the step of forming the pattern of light active semiconductor elements comprises the steps of electrostatically attracting the light active semiconductor elements to a transfer member and then transferring the attracted light active semiconductor elements from the transfer member to the first substrate.

4. A method of forming a shoot of light active material according to claim 3;

wherein the transfer member includes an opto-electric coating effective for holding a patterned electrostatic charge, said patterned electrostatic charge being effective for electrostatically attracting the light active semiconductor elements and forming said pattern of light active semiconductor elements.

5. A method of forming a sheet of light active material according to claim 4;

further comprising the step of optically patterning the opto-electric coating using at least one of a scanned laser beam and an LED light source.

6. A method of forming a sheet of light active material according to claim 4;

wherein the transfer member comprises a drum.

7. A method of forming a sheet of light active material according to claim 1;

further comprising the step of forming an adhesive pattern on the first substrate for adhering the pattern of light active semiconductor elements to the first substrate.

8. A method of forming a sheet of light active material according to claim 1;

further comprising the step of forming an adhesive pattern on the first substrate for adhering the second substrate to the first substrate.

9. A method of forming a sheet of light active material according to claim 1;

wherein the step of forming a pattern of light active semiconductor elements comprises the steps of forming a first pattern of first light active semiconductor elements and forming a second pattern of second light active semiconductor elements.

10. A method of forming a sheet of light active material according to claim 9;

wherein the first light active semiconductor elements emit light having a first color and the second light active semiconductor elements emit light having a second color.

11. A method of forming a sheet of light active material according to claim 9;

wherein the first light active semiconductor elements emit light and the second light active semiconductor elements convert light to electrical energy.

12. A method of forming a sheet of light active material according to claim 1;

wherein said first conductive layer is formed as a grid of x-electrodes; and

said second conductive layer if formed as a grid of y-electrodes so that each respective light active semiconductor element is addressable for forming a sheet of light active material capable of functioning as a pixilated display component.

13. A method of forming a sheet of light active material according to claim 1;

wherein the step of forming a pattern of light active semiconductor elements comprises the steps of forming a first pattern of first color light emitting semiconductor elements, forming a second pattern of second color light emitting semiconductor elements and forming a third pattern of third color light emitting semiconductor element;

said first conductive layer is formed as a grid of x-electrodes; and

said second conductive layer if fanned as a grid of y-electrodes so that each respective light active semiconductor is addressable for forming a sheet of light active material capable of functioning as a full-color pixilated display component.

14. A method for forming a light-emitting device, comprising the steps of:

providing a first substrate;

forming a first conductive surface on the first substrate, the first conductive surface being formed as a conductive pattern comprised of at least one of a conductive coating, a conductive ink and a conductive adhesive;

forming a pattern of LED chips on the conductive pattern, each LED chip having an anode and a cathode side;

providing a second substrate;

forming a second conductive surface on the second substrate;

fixing the first substrate to the second substrate so that either of the anode and the cathode side of the LED chip is in electrical communication with the first conductive surface and the other of the anode and the cathode side of the LED chips is in electrical communication with the second conductive surface.

15. A method for forming a light-emitting device according to claim 14;

wherein at least one of the first and the second conductive surface is a transparent conductor.

16. A method for forming a light-emitting device according to claim 14;

wherein at least one of the first and the second conductive surface is preformed on the respective first and second substrate.

17. A method for forming a light-emitting device according to claim 14;

wherein the first conductive surface if formed using a printing method.

18. A method for forming a light-emitting device according to claim 14;

wherein the printing method comprises at least one of an inkjet printing method, a laser printing method, a silk-screen printing method, a gravure printing method and a doner transfer sheet printing method.

19. A method for forming a light-emitting device according to claim 14;

further comprising the step of forming an adhesive layer between the top substrate and the bottom substrate.

20. A method for forming a light-emitting device according to claim 19;

wherein the adhesive layer comprises at least one of a conductive adhesive, a semi-conductive adhesive, an insulative adhesive, a conductive polymer, a semi-conductive polymer, and an insulative polymer.

21. A method for forming a light-emitting device according to claim 14;

further comprising the step of forming a function-enhancing layer between the top substrate layer and the bottom substrate layer, wherein the function-enhancing layer includes at least one of a re-emitter, a light-scatterer, an adhesive, and a conductor.

22. A method of forming a light-emitting device according to claim 14;

wherein the step of forming the pattern of LED chips comprises the steps of electrostatically attracting the LED chips to a transfer member and then transferring the attracted LED chips from the transfer member to the first conductive surface.

23. A method of forming a light-emitting device according to claim 22;

wherein the transfer member includes an opto-electric coating effective for holding a patterned electrostatic charge, said patterned electrostatic charge being effective for electrostatically attracting the LED chips and forming said pattern of LED chips.

24. A method of forming a light-emitting device according to claim 23;

further comprising the step of optically patterning the opto-electric coating using at least one of a scanned laser beam and an LED light source.

25. A method of forming a light-emitting device according to claim 23;

wherein the transfer member comprises a drum.

26. A method for forming a light-to-energy device, comprising the steps of:

providing a first substrate;

forming a first conductive surface on the first substrate, the first conductive surface being formed as a conductive pattern comprised of at least one of a conductive coating, a conductive ink and a conductive adhesive;

forming a pattern of semiconductor elements on the conductive pattern, each semiconductor element comprising a charge donor layer side and a charge acceptor side;

providing a second substrate;

forming a second conductive surface on the second substrate;

fixing the first substrate to the second substrate so that either of the charge donor and the charge acceptor side of the semiconductor elements is in electrical communication with the first conductive surface and the other of the charge donor and the charge acceptor side of the semiconductor elements is in electrical communication with the second conductive surface.

27. A method for forming a light-to-energy device according to claim 26;

wherein at least one of the first and the second conductive surface is a transparent conductor.

28. A method for forming a light-to-energy device according to claim 26;

wherein at least one of the first and the second conductive surface is preformed on the respective first and second substrate.

29. A method for forming a light-to-energy device according to claim 26;

wherein the first conductive surface if formed using a printing method.

30. A method for forming a light-to-energy device according to claim 26;

wherein the printing method comprises at least one of an inkjet printing method, a laser printing method, a silk-screen printing method, a gravure printing method and a donor transfer sheet printing method.

31. A method for forming a light-to-energy device according to claim 26;

further comprising the step of forming an adhesive layer between the top substrate and the bottom substrate.

32. A method for forming a light-to-energy device according to claim 31;

wherein the adhesive layer comprises at least one of a conductive adhesive, a semi-conductive adhesive, an insulative adhesive, a conductive polymer, a semi-conductive polymer, and an insulative polymer.

33. A method for forming a light-to-energy device according to claim 26;

further comprising the step of forming a function-enhancing layer between the top substrate layer and the bottom substrate layer, wherein the function-enhancing layer includes at least one of a re-emitter, a light-scatterer, an adhesive, and a conductor.

34. A method of forming a sheet of light-to-energy device according to claim 26;

wherein the step of forming the pattern of LED chips comprises the steps of electrostatically attracting the LED chips to a transfer member and then transferring the attracted LED chips from the transfer member to the first conductive surface.

35. A method of forming a light-to-energy device according to claim 34;

wherein the transfer member includes an opto-electric coating effective for holding a patterned electrostatic charge, said patterned electrostatic charge being effective for electrostatically attracting the LED chips and forming said pattern of LED chips.

36. A method of forming a light-to-energy device according to claim 35;

further comprising the step of optically patterning the opto-electric coating using at least one of a scanned laser beam and an LED light source.

37. A method of fanning a light-to-energy device according to claim 35;

wherein the transfer member comprises a drum.