LIGHT-EMITTING DEVICE MANUFACTURING METHOD, LIGHT-EMITTING DEVICE, LIGHTING DEVICE, BACKLIGHT, LIQUID-CRYSTAL PANEL, DISPLAY DEVICE, DISPLAY DEVICE MANUFACTURING METHOD, DISPLAY DEVICE DRIVE METHOD AND LIQUID-CRYSTAL DISPLAY DEVICE

• US 20130027623A1
• Filed: 02/22/2011
• Published: 01/31/2013
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: Elux Inc.
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Negishi, Tetsu, Shibata, Akihide, Komiya, Kenji, Iwata, Hiroshi, Takahashi, Akira, Yoshioka, Fumiyoshi
• Granted Patent: US 9,329,433 B2
• Time in Patent Office: Days
• US Class Current: 349/42
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133612 Electrical details
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133628 with cooling means
• CPC Class Codes: H01L 2224/05099 Material
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13599 Material
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/29599 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/95085 being a liquid, e.g. for fluidic self-assembly
• CPC Class Codes: H01L 24/95 at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00013 : Fully indexed content
• 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 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12036 : PN diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/15788 : Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2933/0041 : relating to wavelength conversion elements
• CPC Class Codes: H01L 33/06 : within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/18 : within the light emitting region
• CPC Class Codes: H01L 33/20 : with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/38 : with a particular shape
• 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 metal line 731 is formed in a linear area S of an insulative substrate 720, and moreover a metal line 732 is formed generally parallel to the metal line 731 with a specified distance thereto. The metal line 731 is connected to an n-type semiconductor core 701 of bar-like structure light-emitting elements 710A to 710D, and the metal line 732 is connected to a p-type semiconductor layer 702. By dividing the insulative substrate 720 into a plurality of divisional substrates, a plurality of light-emitting devices in each of which a plurality of bar-like structure light-emitting elements 710 are placed on the divisional substrates are formed.

Claims

1. A light-emitting device manufacturing method comprising:

a placement step for placing a plurality of light-emitting elements on one substrate;

an interconnection step for collectively interconnecting part or entirety of the plurality of light-emitting elements placed on the substrate; and

a substrate dividing step for, after the placement step and the interconnection step, dividing the substrate into a plurality of divisional substrates to form a plurality of light-emitting devices in which a plurality of light-emitting elements are placed on the divisional substrates.

2. The light-emitting device manufacturing method as claimed in claim 1, wherein

in the placement step, the plurality of light-emitting elements are collectively placed on the one substrate.

3. The light-emitting device manufacturing method as claimed in claim 1, wherein

an interconnect pattern for interconnecting the plurality of light-emitting elements is formed on the substrate, and

the interconnect pattern is not formed in cutting areas of the substrate involved in the substrate dividing step.

4. The light-emitting device manufacturing method as claimed in claim 1, wherein

an interconnect pattern for interconnecting the plurality of light-emitting elements is formed on the substrate, and

the interconnect pattern that, even if cut off in the substrate dividing step, does not affect electrical connections is formed in cutting areas of the substrate.

5. The light-emitting device manufacturing method as claimed in claim 1, wherein

the light-emitting elements are not placed in cutting areas of the substrate involved in the substrate dividing step.

6. The light-emitting device manufacturing method as claimed in claim 1, wherein

out of the plurality of light-emitting elements, those light-emitting elements which, even if cut off in the substrate dividing step, have no influence on a desired light emission quantity are placed in cutting areas of the substrate.

7. The light-emitting device manufacturing method as claimed in claim 1, further comprising:

a phosphor application step for, after the placement step and the interconnection step and before the substrate dividing step, applying a phosphor onto the substrate; and

a protective-film application step for, after the phosphor application step, applying a protective film onto the substrate.

8. The light-emitting device manufacturing method as claimed in claim 7, wherein

in the phosphor application step, the phosphor is applied selectively to regions where the plurality of light-emitting elements are placed.

9. The light-emitting device manufacturing method as claimed in claim 1, whereinor more of the light-emitting elements are placed in each of the divisional substrates.

10. The light-emitting device manufacturing method as claimed in claim 1, wherein

in the substrate dividing step, the substrate is divided into at least two or more types of the divisional substrates of different shapes.

11. The light-emitting device manufacturing method as claimed in claim 1, wherein

the placement step for placing the plurality of light-emitting elements onto the substrate includes:

a substrate formation step for preparing the substrate having at least a first electrode and a second electrode on its mounting surface;

an application step for applying a solution containing the plurality of light-emitting elements onto the substrate; and

an array step for applying a voltage to at least the first electrode and the second electrode to make the plurality of light-emitting elements arrayed at positions defined by at least the first electrode and the second electrode.

12. The light-emitting device manufacturing method as claimed in claim 11, wherein

at least the first electrode and the second electrode are used as electrodes for driving the plurality of light-emitting elements.

13. The light-emitting device manufacturing method as claimed in claim 1, wherein

the plurality of light-emitting elements are bar-like shaped, and

the plurality of light-emitting elements are placed on the mounting surface of the substrate so that a longitudinal direction of the plurality of light-emitting elements becomes parallel to the mounting surface of the substrate.

14. The light-emitting device manufacturing method as claimed in claim 13, wherein

each of the bar-like light-emitting elements has a tubular-shaped light-emitting surface that concentrically surrounds a bar-like core.

15. The light-emitting device manufacturing method as claimed in claim 14, wherein

each of the bar-like light-emitting elements has a first-conductive-type bar-like semiconductor core, and a second-conductive-type tubular-shaped semiconductor layer covering an outer periphery of the semiconductor core, and

a one-end side of the semiconductor core of the bar-like light-emitting element is exposed.

16. The light-emitting device manufacturing method as claimed in claim 1, wherein

the plurality of light-emitting elements are a plurality of elements formed on an epitaxial substrate, and the individual elements are separated from on the epitaxial substrate.

17. A light-emitting device comprising:

divisional substrates resulting from dividing one substrate;

a plurality of light-emitting diodes placed on the divisional substrates; and

a first electrode and a second electrode which are formed on the divisional substrates with a specified distance therebetween and to which the plurality of light-emitting diodes are connected, wherein

the plurality of light-emitting diodes mixedly include light-emitting diodes having an anode connected to the first electrode and a cathode connected to the second electrode, and light-emitting diodes having a cathode connected to the first electrode and an anode connected to the second electrode, and

the plurality of light-emitting diodes are driven with an AC voltage applied to between the first electrode and the second electrode by an AC power supply.

18. The light-emitting device as claimed in claim 17, wherein

the divisional substrates are mounted on a heat sink plate.

19. A lighting device including the light-emitting device as claimed in claim 17.

20. A backlight including the light-emitting device as claimed in claim 17.

21. A liquid-crystal panel including the light-emitting device as claimed in claim 17.

22. A liquid-crystal panel comprising:

a transparent substrate;

a plurality of light-emitting elements placed on one surface of the transparent substrate and connected to interconnections formed on the one surface of the transparent substrate; and

a plurality of thin film transistors formed on the other surface of the transparent substrate.

23. A liquid-crystal panel comprising:

a transparent substrate;

a plurality of light-emitting elements placed on one surface of the transparent substrate and connected to interconnections formed on the one surface of the transparent substrate; and

a color filter formed on the other surface of the transparent substrate.

24. A light-emitting device manufacturing method comprising:

a substrate preparation step for preparing a first substrate having a first electrode and a second electrode;

an element feeding step for positioning onto the first substrate an element-containing liquid having a first liquid and a plurality of light-emitting elements positioned within the first liquid; and

an element array step for, with a voltage applied to the first electrode and the second electrode, arraying two or more of the light-emitting elements to predetermined positions determined based on an electric field generated by the voltage application.

25. The light-emitting device manufacturing method as claimed in claim 24, wherein

in the element array step, the element-containing liquid is moved relative to the first substrate.

26. The light-emitting device manufacturing method as claimed in claim 24, further comprising:

a second-substrate placement step for placing a second substrate generally parallel to the first substrate, wherein

in the element feeding step, the element-containing liquid is filled between the first substrate and the second substrate.

27. The light-emitting device manufacturing method as claimed in claim 26, wherein

the second substrate has a third electrode opposed to the first electrode and the second electrode, and

in at least one step of the element feeding step and the element array step, a voltage is applied to between the first electrode and the third electrode.

28. The light-emitting device manufacturing method as claimed in claim 26, wherein

in the element array step, the element-containing liquid is fluidized between the first substrate and the second substrate.

29. The light-emitting device manufacturing method as claimed in claim 24, wherein

a surface of the first electrode and a surface of the second electrode are overlaid with an insulating film.

30. The light-emitting device manufacturing method as claimed in claim 24, wherein

the surface of the first substrate is made from a material identical to a material of the surface of each of the light-emitting elements.

31. The light-emitting device manufacturing method as claimed in claim 24, wherein

the element-containing liquid contains a surface active agent.

32. The light-emitting device manufacturing method as claimed in claim 24, wherein

a maximum distance between different two points in each of the light-emitting elements is not more than 50 μ

m.

33. The light-emitting device manufacturing method as claimed in claim 24, wherein

each of the plurality of light-emitting elements has a bar-like shape.

34. The light-emitting device manufacturing method as claimed in claim 24, wherein

each of the light-emitting elements includes:

a cylindrical-shaped first-conductive-type first semiconductor layer;

a tubular-shaped quantum well layer placed so as to cover an outer peripheral surface of the first semiconductor layer; and

a tubular-shaped second-conductive-type second semiconductor layer placed so as to cover an outer peripheral surface of the quantum well layer.

35. The light-emitting device manufacturing method as claimed in claim 24, wherein

each of the plurality of light-emitting elements has a bar-like shape, and

a diameter of a cross section of each light-emitting element as taken along a direction vertical to an extending direction of the light-emitting element is larger than 500 nm.

36. The light-emitting device manufacturing method as claimed in claim 24, wherein

each of the light-emitting elements includes:

a cylindrical-shaped first-conductive-type first semiconductor layer;

a tubular-shaped quantum well layer placed so as to cover an outer peripheral surface of the first semiconductor layer; and

a tubular-shaped second-conductive-type second semiconductor layer placed so as to cover an outer peripheral surface of the quantum well layer, wherein

a diameter of a cross section of each light-emitting element as taken along a direction vertical to an extending direction of the light-emitting element is larger than 500 nm.

37. The light-emitting device manufacturing method as claimed in claim 24, further comprising

an element discharge step for discharging light-emitting elements that have not been arrayed at predetermined places out of the plurality of light-emitting elements.

38. The light-emitting device manufacturing method as claimed in claim 24, further comprising

an element fixing step for, after the element array step, with a voltage applied to between the first electrode and the second electrode, the voltage higher than the voltage applied to between the first electrode and the second electrode in the element array step, fixing the light-emitting elements, which have been arrayed at predetermined positions, to the predetermined positions.

39. The light-emitting device manufacturing method as claimed in claim 24, further comprising

a substrate drying step for, after the element array step, drying the surface of the first substrate.

40. The light-emitting device manufacturing method as claimed in claim 24, wherein

a surface tension of the element-containing liquid is not more than 50 mN/m.

41. The light-emitting device manufacturing method as claimed in claim 24, wherein

a surface tension of the element-containing liquid is not more than 30 mN/m.

42. The light-emitting device manufacturing method as claimed in claim 39, further comprising

a liquid replacement step for, after the element feeding step and before the substrate drying step, replacing the first liquid with a second liquid smaller in surface tension than the first liquid.

43. The light-emitting device manufacturing method as claimed in claim 24, wherein

each of the light-emitting elements has, on its surface, a first region and a second region and emits light with a voltage applied to the first region and the second region, the method further comprising

an element connecting step for connecting the first region and the first electrode to each other with an electrical conductor and moreover connecting the second region and the second electrode to each other with an electrical conductor.

44. The light-emitting device manufacturing method as claimed in claim 24, wherein

each of the light-emitting elements has, on its surface, a first region and a second region and emits light with a voltage applied to the first region and the second region, the method further comprising

an additional electrode formation step for forming a fourth electrode to be connected to two or more of the first regions of two or more of the light-emitting elements arrayed at predetermined positions, and a fifth electrode to be connected to two or more of the second regions of two or more of the light-emitting elements arrayed at predetermined positions.

45. The light-emitting device manufacturing method as claimed in claim 24, further comprising

a substrate dividing step for, after the element array step, dividing the first substrate.

46. The light-emitting device manufacturing method as claimed in claim 24, wherein

in the element array step, the light-emitting elements counting 1000 or more in number are arrayed on the first substrate.

47. A display device comprising:

a substrate;

a plurality of first interconnect lines formed so as to extend in one direction on the substrate;

a plurality of second interconnect lines formed so as to extend in another direction on the substrate; and

a plurality of light-emitting elements placed in a matrix array on the substrate, wherein

one end portion of each of the light-emitting elements is electrically connected directly to one of the plurality of first interconnect lines while the other end portion of the light-emitting element is electrically connected directly to one of the plurality of second interconnect lines, and

the or each light-emitting element has a length to width ratio of 5 to 400 and the length is 0.5 μ

m to 200 μ

m.

48. The display device as claimed in claim 47, wherein

each of the light-emitting elements includes:

a bar-like first-conductive-type semiconductor; and

a second-conductive-type semiconductor which coaxially covers part of the first-conductive-type semiconductor.

49. The display device as claimed in claim 47, wherein

the plurality of light-emitting elements include red light-emitting elements for emitting red light, green light-emitting elements for emitting green light, and blue light-emitting elements for emitting blue light.

50. The display device as claimed in claim 49, wherein

light-emission areas of the red light-emitting elements, the green light-emitting elements and the blue light-emitting elements are adjusted so that when a flow of an equal current is given to the red light-emitting elements, the green light-emitting elements and the blue light-emitting elements, mixing of red light by the red light-emitting elements, green light by the green light-emitting elements, and blue light by the blue light-emitting elements allows white light to be obtained.

51. The display device as claimed in claim 47, further comprising

a plurality of phosphors on which emitted light of the plurality of light-emitting elements goes incident, wherein

emitted light of the light-emitting elements is ultraviolet light, and

the plurality of phosphors include a red phosphor for emitting red light on incidence of the ultraviolet light, a green phosphor for emitting green light on incidence of the ultraviolet light, and a blue phosphor for emitting blue light on incidence of the ultraviolet light.

52. The display device as claimed in claim 51, wherein

respective light-emission areas of the plurality of light-emitting elements are adjusted so that when a flow of an equal current is given to the plurality of light-emitting elements, mixing of the red light by the red phosphor, the green light by the green phosphor, and the blue light by the blue phosphor allows white light to be obtained.

53. The display device as claimed in claim 47, wherein

the substrate is a flexible board.

57. A display device driving method for implementation of display by the display device as defined in claim 47, wherein

an AC voltage is applied to the first interconnect lines and the second interconnect lines so that the light-emitting elements emit light.

54. A display device manufacturing method comprising:

a first-interconnect-line formation step for forming a plurality of first interconnect lines extending in one direction on a substrate;

an insulating film formation step for forming an insulating film on the substrate so as to cover the plurality of first interconnect lines;

an exposure step for removing parts of the insulating film to form a plurality of openings so that parts of the first interconnect lines are exposed within the openings, respectively;

a second-interconnect-line formation step for forming a plurality of second interconnect lines extending in another direction on the insulating film having the plurality of openings formed therein and moreover putting parts of the second interconnect lines into the openings, respectively;

an application step for applying a liquid containing a plurality of light-emitting elements onto the first interconnect lines and the second interconnect lines; and

an array step for, with a voltage applied to the first interconnect lines and the second interconnect lines, arraying the plurality of light-emitting elements so that one end portions of the light-emitting elements are positioned on parts of the first interconnect lines within the openings while the other end portions of the light-emitting elements are positioned on parts of the second interconnect lines within the openings, respectively.

55. The display device manufacturing method as claimed in claim 54, wherein

the plurality of light-emitting elements include a plurality of red light-emitting elements for emitting red light, a plurality of green light-emitting elements for emitting green light, and a plurality of blue light-emitting elements for emitting blue light,

the plurality of openings include a plurality of red light-emitting element-use openings for placement of the red light-emitting elements, a plurality of green light-emitting element-use openings for placement of the green light-emitting elements, and a plurality of blue light-emitting element-use openings for placement of the blue light-emitting elements,

parts of the first interconnect lines are exposed in the red light-emitting element-use openings, in the green light-emitting element-use openings, and in the blue light-emitting element-use openings,

parts of the second interconnect lines are put into the red light-emitting element-use openings, into the green light-emitting element-use openings, and into the blue light-emitting element-use openings,

the application step includes:

a step for applying a liquid containing the plurality of red light-emitting elements onto the first interconnect lines and the second interconnect lines;

a step for applying a liquid containing the plurality of green light-emitting elements onto the first interconnect lines and the second interconnect lines; and

a step for applying a liquid containing the plurality of blue light-emitting elements onto the first interconnect lines and the second interconnect lines, and wherein

the array step includes;

a step for, with a voltage applied to the first interconnect lines and the second interconnect lines corresponding to the red light-emitting elements, arraying the plurality of red light-emitting elements so that one end portions of the red light-emitting elements are positioned onto parts of the first interconnect lines within the red light-emitting element-use openings while the other end portions of the red light-emitting elements are positioned onto parts of the second interconnect lines within the red light-emitting element-use openings;

a step for, with a voltage applied to the first interconnect lines and the second interconnect lines corresponding to the green light-emitting elements, arraying the plurality of green light-emitting elements so that one end portions of the green light-emitting elements are positioned onto parts of the first interconnect lines within the green light-emitting element-use openings while the other end portions of the green light-emitting elements are positioned onto parts of the second interconnect lines within the green light-emitting element-use openings; and

a step for, with a voltage applied to the first interconnect lines and the second interconnect lines corresponding to the blue light-emitting elements, arraying the plurality of blue light-emitting elements so that one end portions of the blue light-emitting elements are positioned onto parts of the first interconnect lines within the blue light-emitting element-use openings while the other end portions of the blue light-emitting elements are positioned onto parts of the second interconnect lines within the blue light-emitting element-use openings.

56. The display device manufacturing method as claimed in claim 54, wherein

emitted light of the light-emitting elements is ultraviolet light,

the plurality of openings include a plurality of red phosphor-use openings, a plurality of green phosphor-use openings, and a plurality of blue phosphor-use openings,

parts of the first interconnect lines are exposed in the red phosphor-use openings, in the green phosphor-use openings, and in the blue phosphor-use openings, and

parts of the second interconnect lines are put into the red phosphor-use openings, into the green phosphor-use openings, and into the blue phosphor-use openings, the display device manufacturing method further comprising

a phosphor formation step for forming in the red phosphor-use openings a red phosphor which emits red light upon reception of the ultraviolet light, forming in the green phosphor-use openings a green phosphor which emits green light upon reception of the ultraviolet light, and forming in the blue phosphor-use openings a blue phosphor which emits blue light upon reception of the ultraviolet light.

58. A liquid crystal display device comprising:

a light-pervious first substrate;

a light-pervious second substrate;

liquid crystals filled between the first substrate and the second substrate; and

light-emitting elements placed on one surface of the first substrate opposite to a liquid-crystal side surface.

59. The liquid crystal display device as claimed in claim 58, wherein

each of the light-emitting elements includes:

a bar-like first-conductive-type semiconductor core; and

a second-conductive-type semiconductor layer formed so as to cover the semiconductor core, wherein

the or each light-emitting element is placed on the first substrate so that an axis of the light-emitting element becomes generally parallel to the surface of the first substrate.

60. The liquid crystal display device as claimed in claim 58, wherein

light-passing regions through which light emitted from the light-emitting elements passes are provided in the first substrate or the second substrate, and

the light-emitting elements are placed at positions overlapping with the light-passing regions as viewed in directions orthogonal to the surface of the first substrate, and each of the light-emitting elements is smaller than each light-passing region.

61. The liquid crystal display device as claimed in claim 58, further comprising

a reflection film for reflecting light, which is emitted from the light-emitting elements, toward the first substrate side.

62. The liquid crystal display device as claimed in claim 61, wherein

the reflection film is stacked on a transparent protective film stacked on the light-emitting elements.

63. The liquid crystal display device as claimed in claim 58, wherein

thin film transistors as switching elements are provided on a liquid-crystal side surface of the first substrate.

64. The liquid crystal display device as claimed in claim 58, wherein

thin film transistors as switching elements are provided on a liquid-crystal side surface of the second substrate.