LIGHT-EMITTING DIODE DISPLAY AND METHOD FOR MANUFACTURING THE SAME

• US 20090278142A1
• Filed: 04/29/2009
• Published: 11/12/2009
• Est. Priority Date: 05/12/2008
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Doi, Masato, Watanabe, Toshihiko, Muraguchi, Shoichi
• Granted Patent: US 7,795,629 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/68363 used in a transfer process involving transfer directly from an origin substrate to a target substrate without use of an intermediate handle substrate
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/24051 Conformal with the semiconductor or solid-state device
• CPC Class Codes: H01L 2224/24226 the HDI interconnect connecting to the same level of the item at which the semiconductor or solid-state body is mounted, e.g. the item being planar
• CPC Class Codes: H01L 2224/76155 Jetting means, e.g. ink jet
• CPC Class Codes: H01L 2224/82102 using jetting, e.g. ink jet
• CPC Class Codes: H01L 24/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 24/82 by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/01024 Chromium [Cr]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/0103 Zinc [Zn]
• CPC Class Codes: H01L 2924/01032 Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/0104 : Zirconium [Zr]
• CPC Class Codes: H01L 2924/01041 : Niobium [Nb]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01056 : Barium [Ba]
• CPC Class Codes: H01L 2924/01073 : Tantalum [Ta]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/10329 : Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/15788 : Glasses, e.g. amorphous oxides, nitrides or fluorides

Abstract

A method for manufacturing a light-emitting diode display is provided. The method includes pre-fixing first, second, and third light-emitting diodes on a light emitting unit production substrate to produce light-emitting units each including first, second, and third light-emitting diodes, first electrodes of the first, second, and third light-emitting diodes being connected to a sub-common electrode. The method also includes transferring and fixing the light-emitting units from the light-emitting unit production substrate to a display substrate to produce a light-emitting diode display including the light-emitting units which are arranged in a first direction and a second direction perpendicular to the first direction (i.e., arranged in a two-dimensional matrix).

Claims

1. A method for manufacturing a light-emitting diode display, the method comprising:

(A) providing a plurality of first light-emitting diodes which emit red light on a first light-emitting diode production substrate, the first light-emitting diodes each including (a-1) a first compound semiconductor layer having a first conductivity type, (a-2) an active layer, (a-3) a second compound semiconductor layer having a second conductivity type different from the first conductivity type, (a-4) a first electrode electrically connected to the first compound semiconductor layer, and (a-5) a second electrode electrically connected to the second compound semiconductor layer;

providing a plurality of second light-emitting diodes which emit green light on a second light-emitting diode production substrate, the second light-emitting diodes each including (b-1) a first compound semiconductor layer having a first conductivity type, (b-2) an active layer, (b-3) a second compound semiconductor layer having a second conductivity type different from the first conductivity type, (b-4) a first electrode electrically connected to the first compound semiconductor layer, and (b-5) a second electrode electrically connected to the second compound semiconductor layer; and

providing a plurality of third light-emitting diodes which emit blue light on a third light-emitting diode production substrate, the third light-emitting diodes each including (c-1) a first compound semiconductor layer having a first conductivity type, (c-2) an active layer, (c-3) a second compound semiconductor layer having a second conductivity type different from the first conductivity type, (c-4) a first electrode electrically connected to the first compound semiconductor layer, and (c-5) a second electrode electrically connected to the second compound semiconductor layer;

(B) pre-fixing the first light-emitting diodes, the second light-emitting diodes, and the third light-emitting diodes to a light-emitting unit production substrate to form a light-emitting unit which includes a desired number of the first light-emitting diodes, a desired number of the second light-emitting diodes, and a desired number of the third light-emitting diodes, the first electrodes of each first light-emitting diode, each second light-emitting diode, and each third light-emitting diodes being connected to a sub-common electrode; and

(C) transferring and fixing the light-emitting unit to a display substrate from the light-emitting unit production substrate to produce a light-emitting diode display including a plurality of light-emitting units arranged in a two-dimensional matrix.

2. The method for manufacturing a light-emitting diode display according to claim 1,

wherein an arrangement pitch of the first light-emitting diodes in the light-emitting diode display is an integral multiple of a manufacturing pitch of the first light-emitting diodes on the first light-emitting diode production substrate;

an arrangement pitch of the second light-emitting diodes in the light-emitting diode display is an integral multiple of the manufacturing pitch of the second light-emitting diodes on the second light-emitting diode production substrate; and

an arrangement pitch of the third light-emitting diodes in the light-emitting diode display is an integral multiple of the manufacturing pitch of the third light-emitting diodes on the third light-emitting diode production substrate.

3. The method for manufacturing a light-emitting diode display according to claim 1,

wherein a first transfer substrate having a fixed layer is prepared;

the step (B) includes;

(B-1) transferring the first light-emitting diodes on the first light-emitting diode production substrate to the fixed layer, transferring the second light-emitting diodes on the second light-emitting diode production substrate to the fixed layer, and transferring the third light-emitting diodes on the third light-emitting diode production substrate to the fixed layer;

(B-2) forming the sub-common electrode from the first electrodes of a light-emitting diode group to the fixed layer, the light-emitting diode group including a desired number of the first light-emitting diodes, a desired number of the second light-emitting diodes, and a desired number of the third light-emitting diodes which form each light-emitting unit;

(B-3) bonding and pre-fixing, through the fixed layer and the sub-common electrode, the light-emitting diode group which forms each light-emitting unit to the light-emitting diode unit production substrate and then removing the first transfer substrate;

(B-4) forming first contact holes, which are connected to the second electrodes of the first light-emitting diodes, in the fixed layer and forming first pad portions extending from the first contact holes to the fixed layer, forming second contact holes, which are connected to the second electrodes of the second light-emitting diodes, in the fixed layer and forming second pad portions extending from the second contact holes to the fixed layer, forming third contact holes, which are connected to the second electrodes of the third light-emitting diodes, in the fixed layer and forming third pad portions extending from the third contact holes to the fixed layer, and forming fourth contact holes, which are connected to the sub-common electrode, in the fixed layer and forming fourth pad portions extending from the fourth contact holes to the fixed layer to form light-emitting units; and

(B-5) separating the light-emitting units in the fixed layer;

a display substrate on which an insulating material layer and a first, second, and third common electrodes covered with the insulating material layer and extending in a first direction are formed is prepared; and

the step (C) includes;

(C-1) bonding the light-emitting units to a second transfer substrate and removing the light-emitting unit production substrate;

(C-2) arranging the light-emitting units on the display substrate so that the light-emitting units are surrounded by the insulating material layer and then removing the second transfer substrate; and

(C-3) forming first connection portions for electrically connecting the first pad portions to the first common electrode so that the first connection portions extend from the fixed layer to the insulating material layer;

forming second connection portions for electrically connecting the second pad portions to the second common electrode so that the second connection portions extend from the fixed layer to the insulating material layer;

forming third connection portions for electrically connecting the third pad portions to the third common electrode so that the third connection portions extend from the fixed layer to the insulating material layer;

forming a fourth common electrode on the insulating material layer; and

forming fourth connection portions for electrically connecting the fourth pad portions to the fourth common electrode so that the first connection portions extend from the fixed layer to the insulating material layer.

4. The method for manufacturing a light-emitting diode display according to claim 1,

wherein a first transfer substrate having a fixed layer is prepared;

the step (B) includes;

(B-1) transferring the first light-emitting diodes on the first light-emitting diode production substrate to the fixed layer, transferring the second light-emitting diodes on the second light-emitting diode production substrate to the fixed layer, and transferring the third light-emitting diodes on the third light-emitting diode production substrate to the fixed layer;

(B-2) forming the sub-common electrode from the first electrodes of a light-emitting diode group to the fixed layer, the light-emitting diode group including a desired number of the first light-emitting diodes, a desired number of the second light-emitting diodes, and a desired number of the third light-emitting diodes which form each light-emitting unit;

(B-3) bonding and pre-fixing the light-emitting diode group, which forms each light-emitting unit, to the light-emitting diode unit production substrate through the fixed layer and the sub-common electrode;

(B-4) forming first contact holes, which are connected to the second electrodes of the first light-emitting diodes, in the fixed layer and forming first pad portions extending from the first contact holes to the fixed layer, forming second contact holes, which are connected to the second electrodes of the second light-emitting diodes, in the fixed layer and forming second pad portions extending from the second contact holes to the fixed layer, forming third contact holes, which are connected to the second electrodes of the third light-emitting diodes, in the fixed layer and forming third pad portions extending from the third contact holes to the fixed layer, and forming fourth contact holes connected to the sub-common electrode in the fixed layer and forming fourth pad portions extending from the fourth contact holes on the fixed layer to form light-emitting units; and

(B-5) separating the light-emitting units in the fixed layer;

a display substrate on which first, second, and third common electrodes are formed to extend in a first direction is prepared; and

the step (C) includes;

(C-1) bonding the light-emitting units to a second transfer substrate and removing the light-emitting unit production substrate;

(C-2) arranging the light-emitting units on the display substrate and then removing the second transfer substrate;

(C-3) forming an insulating material layer to cover the first, second, and third common electrodes and surround the light-emitting units; and

(C-4) forming first connection portions for electrically connecting the first pad portions to the first common electrode so that the first connection portions extend from the fixed layer to the insulating material layer;

forming second connection portions for electrically connecting the second pad portions to the second common electrode so that the second connection portions extend from the fixed layer to the insulating material layer;

forming third connection portions for electrically connecting the third pad portions to the third common electrode so that the third connection portions extend from the fixed layer to the insulating material layer;

forming a fourth common electrode on the insulating material layer; and

forming fourth connection portions for electrically connecting the fourth pad portions to the fourth common electrode so that the first, connection portions extend from the fixed layer to the insulating material layer.

5. The method for manufacturing a light-emitting diode display according to claim 1,

wherein a first transfer substrate having a fixed layer is prepared;

the step (B) includes the steps of;

(B-1) transferring the first light-emitting diodes on the first light-emitting diode production substrate to the fixed layer, transferring the second light-emitting diodes on the second light-emitting diode production substrate to the fixed layer, and transferring the third light-emitting diodes on the third light-emitting diode production substrate to the fixed layer;

(B-2) forming the sub-common electrode from the first electrodes of a light-emitting diode group to the fixed layer, the light-emitting group including a desired number of the first light-emitting diodes, a desired number of the second light-emitting diodes, and a desired number of the third light-emitting diodes which form each light-emitting unit;

(B-3) bonding and pre-fixing the light-emitting diode group, which forms each light-emitting unit, to the light-emitting diode unit production substrate through the fixed layer and the sub-common electrodes to produce light-emitting units and then removing the first transfer substrate; and

(B-4) separating the light-emitting units in the fixed layer;

a display substrate on which an insulating material layer and a first, second, and third common electrodes covered with the insulating material layer and extending in a first direction are formed is prepared; and

the step (C) includes;

(C-1) bonding the light-emitting units to a second transfer substrate and removing the light-emitting unit production substrate;

(C-2) arranging the light-emitting units on the display substrate so that the light-emitting units are surrounded by the insulating material layer and then removing the second transfer substrate; and

(C-3) forming first contact holes in the fixed layer in order to electrically connect the second electrodes of the first light-emitting diodes to the first common electrode and forming first connection portions so that the first connection portions extend from the fixed layer to the insulating material layer;

forming second contact holes in the fixed layer in order to electrically connect the second electrodes of the second light-emitting diodes to the second common electrode and forming second connection portions so that the second connection portions extend from the fixed layer to the insulating material layer;

forming third contact holes in the fixed layer in order to electrically connect the second electrodes of the third light-emitting diodes to the third common electrode and forming third connection portions so that the third connection portions extend from the fixed layer to the insulating material layer;

forming a fourth common electrode on the insulating material layer; and

forming fourth contact holes in the fixed layer in order to electrically connect the sub-common electrode to the fourth common electrode and forming fourth connection portions so that the fourth connection portions extend from the fixed layer to the insulating material layer.

6. The method for manufacturing a light-emitting diode display according to claim 1,

wherein a first transfer substrate having a fixed layer is prepared;

step (B) includes;

(B-1) transferring the first light-emitting diodes on the first light-emitting diode production substrate to the fixed layer, transferring the second light-emitting diodes on the second light-emitting diode production substrate to the fixed layer, and transferring the third light-emitting diodes on the third light-emitting diode production substrate to the fixed layer;

(B-2) forming the sub-common electrode from the first electrodes of a light-emitting diode group to the fixed layer, the light-emitting diode group including a desired number of the first light-emitting diodes, a desired number of the second light-emitting diodes, and a desired number of the third light-emitting diodes which form each light-emitting unit;

(B-3) bonding and pre-fixing the light-emitting diode group, which forms each light-emitting unit, to the light-emitting diode unit production substrate through the fixed layer and the sub-common electrodes to produce light-emitting units and then removing the first transfer substrate; and

(B-4) separating the light-emitting units in the fixed layer;

a display substrate on which first, second, and third common electrodes are formed to extend in a first direction is prepared; and

the step (C) includes;

(C-1) bonding the light-emitting units to a second transfer substrate and removing the light-emitting unit production substrate;

(C-2) arranging the light-emitting units on the display substrate and then removing the second transfer substrate;

(C-3) forming an insulating material layer to cover the first, second, and third common electrodes and surround the light-emitting units; and

(C-4) forming first contact holes in the fixed layer in order to electrically connect the second electrodes of the first light-emitting diodes to the first common electrode and forming first connection portions so that the first connection portions extend from the fixed layer to the insulating material layer;

forming second contact holes in the fixed layer in order to electrically connect the second electrodes of the second light-emitting diodes to the second common electrode and forming second connection portions so that the second connection portions extend from the fixed layer to the insulating material layer;

forming third contact holes in the fixed layer in order to electrically connect the second electrodes of the third light-emitting diodes to the third common electrode and forming third connection portions so that the third connection portions extend from the fixed layer to the insulating material layer;

forming a fourth common electrode on the insulating material layer; and

forming fourth contact holes in the fixed layer in order to electrically connect the sub-common electrode to the fourth common electrode and forming fourth connection portions so that the fourth connection portions extend from the fixed layer to the insulating material layer.

7. The method for manufacturing a light-emitting diode display according to claim 3,

wherein the size of the first pad portions is larger than the size of the second electrodes of the first light-emitting diodes;

the size of the second pad portions is larger than the size of the second electrodes of the second light-emitting diodes; and

the size of the third pad portions is larger than the size of the second electrodes of the third light-emitting diodes.

8. The method for manufacturing a light-emitting diode display according to claim 4,

wherein the size of the first pad portions is larger than the size of the second electrodes of the first light-emitting diodes;

the size of the second pad portions is larger than the size of the second electrodes of the second light-emitting diodes; and

the size of the third pad portions is larger than the size of the second electrodes of the third light-emitting diodes.

9. The method for manufacturing a light-emitting diode display according to claim 1,

wherein light emitted from the first, second, and third light-emitting diodes is emitted from the first electrode side, and the sub-common electrode has a light-transmitting structure.

10. The method for manufacturing a light-emitting diode display according to claim 9, wherein the sub-common electrode includes a metal layer or alloy layer.

11. The method for manufacturing a light-emitting diode display according to claim 9,

wherein the sub-common electrode includes a light-transmitting electrode and a metal layer or alloy layer extending from the light-transmitting electrode;

the first electrodes of the first, second, and third light-emitting diodes are in contact with the light-transmitting electrode; and

the fourth contact holes are in contact with the metal layer or alloy layer.

12. The method for manufacturing a light-emitting diode display according to claim 1, wherein the following relationships are satisfied:

L_U-1/L_P-1≦

0.5

L_U-2/L_P-2≦

0.5

wherein L_P-1 and L_P-2 are lengths along the first direction and the second direction, respectively, of one pixel including the first, second, and third light-emitting diodes, and L_U-1 and L_U-2 are lengths along the first direction and the second direction, respectively, of one light-emitting unit.

13. The method for manufacturing a light-emitting diode display according to claim 12, wherein the following relationships are satisfied:

L_U-1/L_P-1≦

0.5

L_U-2/L_P-2≦

0.25.

14. The method for manufacturing a light-emitting diode display according to claim 1, wherein the following relationship is satisfied:

2.5×

10<sup>−

11</sup> m²≦

S_max≦

1×

10<sup>−

8</sup> m²,

wherein S_max is the area of the emission surface of the largest light-emitting diode among the first, second, and third light-emitting diodes.

15. A light-emitting diode display comprising:

a plurality of light-emitting units arranged in a first direction and a second direction perpendicular to the first direction, the light-emitting units each including;

a desired number of first light-emitting diodes which emit red light and each of which includes (a-1) a first compound semiconductor layer having a first conductivity type, (a-2) an active layer, (a-3) a second compound semiconductor layer having a second conductivity type different from the first conductivity type, (a-4) a first electrode electrically connected to the first compound semiconductor layer, and (a-5) a second electrode electrically connected to the second compound semiconductor layer;

a desired number of second light-emitting diodes which emit green light and each of which includes (h-1) a first compound semiconductor layer having a first conductivity type, (b-2) an active layer, (b-3) a second compound semiconductor layer having a second conductivity type different from the first conductivity type, (b-4) a first electrode electrically connected to the first compound semiconductor layer, and (b-5) a second electrode electrically connected to the second compound semiconductor layer; and

a desired number of third light-emitting diodes which emit blue light and each of which includes (c-1) a first compound semiconductor layer having a first conductivity type, (c-2) an active layer, (c-3) a second compound semiconductor layer having a second conductivity type different from the first conductivity type, (c-4) a first electrode electrically connected to the first compound semiconductor layer, and (c-5) a second electrode electrically connected to the second compound semiconductor layer;

wherein the first electrodes of the first, second, and third light-emitting diodes in each of the light-emitting units are connected to a sub-common electrode;

the second electrodes of the first, second, and third light-emitting diodes in each of the light-emitting units arranged in the first direction are connected to first, second, and third common electrodes, respectively, which extend in the first direction; and

the sub-common electrodes of the light-emitting units arranged in the second direction are connected to a fourth common electrode extending in the second direction.

16. The light-emitting diode display according to claim 15,

wherein the first, second, and third common electrodes are formed on a display substrate;

the sub-common electrodes are formed in a fixed layer fixed on the display substrate;

the first, second, and third light-emitting diodes in the light-emitting units are fixed in the fixed layer;

the fixed layer is surrounded by an insulating material layer which covers the first, second, and third common electrodes;

the first, second, and third light-emitting diodes in the light-emitting units are disposed on the sub-common electrode so that the first electrodes of the light-emitting diodes are connected to the sub-common electrode;

the second electrodes of the first light-emitting diodes are connected to the first common electrode through first contact holes formed in the fixed layer and first connection portions formed to extend from the fixed layer to the insulating material layer;

the second electrodes of the second light-emitting diodes are connected to the second common electrode through second contact holes formed in the fixed layer and second connection portions formed to extend from the fixed layer to the insulating material layer;

the second electrodes of the third light-emitting diodes are connected to the third common electrode through third contact holes formed in the fixed layer and third connection portions formed to extend from the fixed layer to the insulating material layer; and

the sub-common electrodes are connected to the fourth common electrode formed on the insulating material layer through fourth contact holes formed in the fixed layer and fourth connection portions formed to extend from the fixed layer to the insulating material layer.

17. The light-emitting diode display according to claim 16,

wherein first pad portions are provided in the fixed layer and disposed between the first contact holes and the first connection portions;

second pad portions are provided in the fixed layer and disposed between the second contact holes and the second connection portions;

third pad portions are provided in the fixed layer and disposed between the third contact holes and the third connection portions; and

fourth pad portions are provided in the fixed layer and disposed between the fourth contact holes and the fourth connection portions.

18. The light-emitting diode display according to claim 17,

wherein a size of the first pad portions is larger than a size of the second electrodes of the first light-emitting diodes;

a size of the second pad portions is larger than the size of a second electrodes of the second light-emitting diodes; and

a size of the third pad portions is larger than a size of the second electrodes of the third light-emitting diodes.

19. The light-emitting diode display according to claim 15,

wherein light emitted from the first, second, and third light-emitting diodes is emitted from the first electrode side, and the sub-common electrode has a light-transmitting structure.

20. The light-emitting diode display according to claim 19, the sub-common electrode includes a metal layer or alloy layer.

21. The light-emitting diode display according to claim 19,

wherein the sub-common electrode includes a light-transmitting electrode and a metal layer or alloy layer extending from the light-transmitting electrode;

the first electrodes of the first, second, and third light-emitting diodes are in contact with the light-transmitting electrode; and

the fourth contact holes are in contact with the metal layer or alloy layer.

22. The light-emitting diode display according to claim 15, wherein the following relationships are satisfied:

L_U-1/L_P-1≦

0.5

L_U-2/L_P-2≦

0.5

wherein L_P-1 and L_P-2 are lengths along the first direction and the second direction, respectively, of one pixel including the first, second, and third light-emitting diodes, and L_U-1 and L_U-2 are lengths along the first direction and the second direction, respectively, of one light-emitting unit.

23. The light-emitting diode display according to claim 22, wherein the following relationships are satisfied:

L_U-1/L_P-1≦

0.5

L_U-2/L_P-2≦

0.25.

24. The light-emitting diode display according to claim 15, wherein the following relationship is satisfied:

2.5×

10<sup>−

11</sup> m²≦

S_max≦

1×

10<sup>−

8</sup> m²,

wherein S_max is the area of the emission surface of the largest light-emitting diode among the first, second, and third light-emitting diodes.