CN114613800A

CN114613800A - Display device

Info

Publication number: CN114613800A
Application number: CN202210348227.XA
Authority: CN
Inventors: 林圣凯; 刘仲展
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2021-11-16
Filing date: 2022-04-01
Publication date: 2022-06-10
Also published as: TWI798938B; TW202322381A

Abstract

A display device comprises a circuit substrate and a plurality of light-emitting elements. The circuit substrate is provided with a first surface and a second surface which are opposite. The plurality of light emitting elements are located on the first surface of the circuit substrate and electrically connected to the circuit substrate, wherein a first distance is formed between a first light emitting element of the plurality of light emitting elements and the second surface, a second distance is formed between a second light emitting element of the plurality of light emitting elements and the second surface, and the first distance is not equal to the second distance.

Description

Display device

Technical Field

The present invention relates to a display device.

Background

The Micro light emitting diode (Micro-LED) display device has the advantages of electricity saving, high efficiency, high brightness, quick response time and the like. Because of the extremely small size of the micro light emitting diode, the current method for manufacturing the micro light emitting diode display device adopts a Mass Transfer (Mass Transfer) technology, that is, a micro electro mechanical array technology is used for taking and placing the micro light emitting diode crystal grains, so that a large number of micro light emitting diode crystal grains are transported to a circuit substrate at one time. However, the bulk transfer technique often causes the die to be misaligned, tilted or missing, resulting in abnormal color development and poor yield of the display device.

Disclosure of Invention

The invention provides a display device with improved yield.

One embodiment of the present invention provides a display device including: the circuit substrate is provided with a first surface and a second surface which are opposite; and a plurality of light emitting elements located on the first surface of the circuit substrate and electrically connected to the circuit substrate, wherein a first distance is formed between a first light emitting element of the plurality of light emitting elements and the second surface, a second distance is formed between a second light emitting element of the plurality of light emitting elements and the second surface, and the first distance is not equal to the second distance.

In an embodiment of the invention, the first pitch is larger than the second pitch.

In an embodiment of the invention, the first surface has a plurality of grooves.

In an embodiment of the invention, the second light emitting element is located in the groove.

In an embodiment of the invention, the electrode of the second light emitting element is located in the groove.

In an embodiment of the invention, the electrode of the second light emitting element is located outside the groove, and the electrode of the second light emitting element is electrically connected to the circuit substrate through the conductive adhesive.

In an embodiment of the invention, the shape of the groove is square, circular, cross or triangular.

In an embodiment of the invention, the display device further includes a positioning layer covering the first light emitting element.

In an embodiment of the invention, the positioning layer has an opening, and an orthogonal projection of the second light emitting element on the circuit substrate is within an orthogonal projection of the opening on the circuit substrate.

In an embodiment of the invention, the material of the positioning layer is Propylene glycol monomethyl ether acetate (Propylene glycol monomethyl ether acetate), Olefin resin (Olefin resin), Epoxy resin (Epoxy resin), diazonaphthoquinone ester (Naphthoquinone diazide ester), Phenol Compound (Phenol Compound), Acid adduct of Bisphenol fluorene Epoxy acrylate (Acid adduct of Bisphenol fluoro Epoxy acrylate), or Bisphenol a epichlorohydrin resin (Bisphenol Epoxy resin).

Another embodiment of the present invention provides a display device including: a circuit substrate; a plurality of light emitting elements located on the circuit substrate and electrically connected to the circuit substrate; and a positioning layer covering a first light emitting element of the plurality of light emitting elements.

In an embodiment of the invention, the positioning layer has an opening, and an orthogonal projection of a second light emitting element of the plurality of light emitting elements on the circuit substrate is within an orthogonal projection of the opening on the circuit substrate.

In an embodiment of the invention, the second light emitting element is electrically connected to the circuit substrate through a conductive adhesive.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1A is a partial top view of a display device 10 according to an embodiment of the invention.

FIG. 1B is a schematic cross-sectional view taken along section line A-A' of FIG. 1A.

FIG. 1C is a schematic cross-sectional view taken along section line B-B' of FIG. 1A.

Fig. 2A is a partial top view of a display device 20 according to an embodiment of the invention.

FIG. 2B is a schematic cross-sectional view taken along section line C-C' of FIG. 2A.

Fig. 3A is a partial top view of a display device 30 according to an embodiment of the invention.

FIG. 3B is a schematic cross-sectional view taken along section line D-D' of FIG. 3A.

Fig. 4 is a partial top view of a display device 40 according to an embodiment of the invention.

Fig. 5A is a partial top view of a display device 50 according to an embodiment of the invention.

FIG. 5B is a schematic cross-sectional view taken along section line E-E' of FIG. 5A.

Description of reference numerals:

10. 20, 30, 40, 50: display device

A-A ', B-B ', C-C ', D-D ', E-E ': section line

101. 201, 301, 501: first surface

102. 202, 302, 502: second surface

110. 210, 310, 410, 510: circuit board

112. 212, 312, 512: base plate

114. 214, 216, 218, 314, 316, 318, 514: drive circuit layer

120. 121, 122A, 123: light emitting element

220. 221, 222A, 223: light-emitting element

320. 321, 322A, 323: light emitting element

420. 421, 422, 423: light emitting element

520. 521, 522A, 523: light emitting element

530: positioning layer

BP: stop dog

CM: common electrode

D11, D21, D31, D51: first interval

D12, D22, D32, D52: second pitch

E11, E21, E2a1, E2a2, E31: electrode for electrochemical cell

Ga. Gb, Gc, Gd1, Gd2, Gd 3: groove

OP: opening of the container

PD, PD1, PD2, PD3, PD4, PD5, PD6, PD 7: connecting pad

PX, X1a, X1b, X2a, X2 b: pixel unit

X3a, X3b, X5a, X5 b: pixel unit

RU: repeating unit

S3, S5: conductive material

SL1, SL2, SL 3: signal line

Detailed Description

Fig. 1A is a partial top view of a display device 10 according to an embodiment of the invention. FIG. 1B is a schematic cross-sectional view taken along section line A-A' of FIG. 1A. FIG. 1C is a schematic cross-sectional view taken along section line B-B' of FIG. 1A.

Referring to fig. 1A to fig. 1C, the display device 10 includes: a circuit substrate 110 having a first surface 101 and a second surface 102 opposite to each other; and a plurality of light emitting elements 120 located on the first surface 101 of the circuit substrate 110 and electrically connected to the circuit substrate 110, wherein a first distance D11 exists between the

light emitting elements

121, 122, 123 of the plurality of light emitting elements 120 and the second surface 102, a second distance D12 exists between the light emitting element 122A of the plurality of light emitting elements 120 and the second surface 102, and the first distance D11 is not equal to the second distance D12.

Hereinafter, embodiments of the elements of the display device 10 will be described with reference to fig. 1A to 1C, but the present invention is not limited thereto.

In this embodiment, the circuit substrate 110 of the display device 10 may include a bottom substrate 112 and a driving circuit layer 114, wherein the driving circuit layer 114 may be located between the bottom substrate 112 and the light emitting element 120, and the light emitting element 120 may be electrically connected to the driving circuit layer 114.

In detail, the bottom plate 112 may be transparent or opaque, and the material thereof may be glass, but is not limited thereto. In some embodiments, the material of the substrate 112 may be quartz, organic polymer, or opaque/reflective material (e.g., wafer, ceramic, etc.), or other suitable material. Examples of the organic polymer include, but are not limited to, Polyimide (PI), Polycarbonate (PC), Polyester (PET), Cyclic Olefin Copolymer (COC), metal-chromium matrix-cyclic olefin copolymer (mCOC), or other suitable materials.

The driving circuit layer 114 may include elements or lines required for the display device 10, such as driving elements, switching elements, storage capacitors, power supply lines, driving signal lines, timing signal lines, current compensation lines, detection signal lines, and the like. For example, in the embodiment, the display device 10 may include a plurality of pixel units PX, and each pixel unit PX may include signal lines SL1, SL2, SL3 located in the driving circuit layer 114 and pads PD1, PD2, PD3, PD4, PD5, PD6, PD7 located on the driving circuit layer 114, wherein the pads PD1, PD4 may be electrically connected to the signal line SL1, the pads PD2, PD5 may be electrically connected to the signal line SL2, the pads PD3, PD6 may be electrically connected to the signal line SL3, and the pad PD7 may be electrically connected to other signal lines, such as a power line.

In the embodiment, the light emitting device 120 may include the

light emitting devices

121, 122, and 123, and the

light emitting devices

121, 122, and 123 may be located on the same side of the pad PD7, but not limited thereto. The light emitting element 121 is, for example, a red light emitting diode, the light emitting element 122 is, for example, a blue light emitting diode, and the light emitting element 123 is, for example, a green light emitting diode. In this way, the

light emitting elements

121, 122, and 123 may respectively constitute one sub-pixel of the display device 10, and the

light emitting elements

121, 122, and 123 may collectively constitute the pixel unit X1a in the plurality of pixel units PX of the display device 10.

For example, the

light emitting elements

121, 122, and 123 are fabricated on a growth substrate, transferred onto the circuit substrate 110 by a bulk transfer process, and electrically connected to the signal lines SL1, SL2, and SL3, respectively. For example, the signal line SL1 may be electrically connected to the pad PD1 and the pad PD4, the signal line SL2 may be electrically connected to the pad PD2 and the pad PD5, and the signal line SL3 may be electrically connected to the pad PD3 and the pad PD 6. The electrode E11 of the light emitting device 121 may be electrically connected to the pad PD1 or the pad PD4, the electrode E21 of the light emitting device 122 may be electrically connected to the pad PD2 or the pad PD5, the electrode E31 of the light emitting device 123 may be electrically connected to the pad PD3 or the pad PD6, and the other electrodes of the

light emitting devices

121, 122, and 123 may all be electrically connected to the pad PD 7. In the embodiment, the electrode E11 of the light emitting device 121 is electrically connected to the pad PD1, the electrode E21 of the light emitting device 122 is electrically connected to the pad PD2, and the electrode E31 of the light emitting device 123 is electrically connected to the pad PD 3. In some embodiments, the electrodes E11, E21, E31 and other electrodes of the

light emitting elements

121, 122, 123 and the pads PD1, PD2, PD3, PD4, PD5, PD6, PD7 may further include other conductive materials, such as solder or conductive paste (e.g., silver paste).

In this embodiment, the light emitting element 120 may further include a light emitting element 122A, and the light emitting element 122A may have the same light color as the light emitting element 122. In this way, the light-emitting element 122A may constitute one sub-pixel of the display device 10, and the light-emitting

elements

121, 122A, and 123 may together constitute the pixel unit X1b among the plurality of pixel units PX of the display device 10.

The first surface 101 of the circuit substrate 110 may be formed with a plurality of grooves Ga, and the plurality of grooves Ga may be disposed corresponding to the

light emitting elements

121, 122, 123, respectively. When a misalignment, a tilt, or a omission occurs in the process of transferring the

light emitting elements

121, 122, 123, spare light emitting elements of the

light emitting elements

121, 122, 123 may be disposed again in the corresponding grooves Ga through a repair process to repair the sub-pixels that cannot normally operate. In other words, in the present embodiment, each of the grooves Ga may serve as a spare area for repairing the

light emitting elements

121, 122, 123, and the number of the grooves Ga may be equal to the total number of the

light emitting elements

121, 122, 123, but is not limited thereto.

For example, in the embodiment, the plurality of grooves Ga may be respectively disposed corresponding to or adjacent to the

light emitting elements

121, 122, 123, and the orthographic projections of the pads PD4, PD5, PD6 on the circuit substrate 110 may respectively fall into the orthographic projection of each groove Ga on the circuit substrate 110. If the light emitting device 122 in the pixel unit X1a needs to be repaired due to misalignment, inclination, or missing, the light emitting device 122A can be disposed in the groove Ga adjacent to the light emitting device 122 to form a pixel unit like the pixel unit X1 b. Since the light emitting element 122A is disposed in the groove Ga, a first spacing D11 between the electrode E11 of the light emitting element 121, the electrode E21 of the light emitting element 122, or the electrode E31 of the light emitting element 123 and the second surface 102 may be greater than a second spacing D12 between the electrode E2A1 of the light emitting element 122A and the second surface 102.

In the embodiment, the light emitting elements 122 in the pixel unit X1b that are dislocated, tilted or missed in the bulk transfer process can be removed, and the pad PD2 is left, but not limited thereto. In some embodiments, the pad PD2 may be further removed. In other embodiments, the light emitting elements 122 and the pads PD2 may be left misaligned or tilted without affecting the display effect of the display device 10.

Referring to fig. 1C, after the light emitting device 122A is fabricated on the growth substrate, for example, the light emitting device is transferred in the groove Ga by the laser transfer technique, the electrode E2A1 of the light emitting device 122A can be electrically connected to the pad PD5, and the other electrode E2A2 of the light emitting device 122A can be electrically connected to the pad PD 7. In some embodiments, a stopper BP may be further disposed in the groove Ga, and the stopper BP may be located between the pad PD5 and the pad PD7 to prevent the electrode E2A1 and the electrode E2A2 of the light emitting element 122A from being shorted in the process of being electrically connected to the pads PD5 and PD7, respectively. Similarly, the stoppers BP may also be located between the pad PD4 and the pad PD7 and between the pad PD6 and the pad PD7, so as to avoid unnecessary electrical connection during the process of disposing the spare light emitting elements of the

light emitting elements

121 and 123 in the corresponding grooves Ga.

In the display device 10 of the embodiment, the grooves Ga can assist in alignment during the process of disposing the light emitting elements 122A, which is helpful for performing the light emitting element repairing process more accurately and effectively, thereby improving the production yield of the display device 10.

Hereinafter, other embodiments of the present invention will be described with reference to fig. 2A to 5B, and the reference numbers and related contents of the elements of the embodiment of fig. 1A to 1C are used, wherein the same or similar reference numbers are used to indicate the same or similar elements, and the description of the same technical contents is omitted. For the description of the omitted portions, reference may be made to the embodiments of fig. 1A to 1C, which will not be repeated in the following description.

Fig. 2A is a partial top view of a display device 20 according to an embodiment of the invention. FIG. 2B is a schematic cross-sectional view taken along section line C-C' of FIG. 2A. Referring to fig. 2A to 2B, the display device 20 includes: a circuit substrate 210 having a first surface 201 and a second surface 202 opposite to each other; and a plurality of light emitting elements 220 disposed on the first surface 201 of the circuit substrate 210 and electrically connected to the circuit substrate 210, wherein a first distance D21 exists between the

light emitting elements

221, 222, 223 of the plurality of light emitting elements 220 and the second surface 202, a second distance D22 exists between the light emitting element 222A of the plurality of light emitting elements 220 and the second surface 202, and the first distance D21 is not equal to the second distance D22. In addition, the display device 20 may include a plurality of pixel units PX, and the plurality of pixel units PX may include a pixel unit X2a and a pixel unit X2 b.

The display device 20 shown in fig. 2A to 2B is different from the display device 10 shown in fig. 1A to 1C in that: the

light emitting elements

221, 222, 223 of the display device 20 are located on different sides of the pad PD7, and the circuit substrate 210 of the display device 20 has a plurality of pairs of circular grooves Gb.

For example, in the embodiment, the

light emitting elements

221 and 223 of the display device 20 may be located on the upper side of the pad PD7, and the light emitting element 222 may be located on the lower side of the pad PD7, but not limited thereto. Thus, the light-emitting field pattern and the viewing angle of the light-emitting

elements

221, 222, 223 can be further adjusted.

In the present embodiment, the circuit substrate 210 of the display device 20 may include a bottom substrate 212 and driving

circuit layers

214, 216, and 218, wherein the driving

circuit layers

214, 216, and 218 may be located between the bottom substrate 212 and the light emitting element 220, and the light emitting element 220 may be electrically connected to the driving

circuit layers

214, 216, and 218. Specifically, the signal lines SL1, SL2, SL3 may be disposed in the driving

circuit layers

214, 216, 218, the pads PD1, PD3, PD5 may be disposed on the driving circuit layer 218, and the pads PD2, PD4, PD6 may be disposed in the driving circuit layer 216 on the driving circuit layer 214. The driving circuit layer 218 may have a plurality of pairs of corresponding grooves Gb, and an orthographic projection of one of each pair of grooves Gb on the circuit substrate 210 may overlap an orthographic projection of the pad PD2, the pad PD4, or the pad PD6 on the circuit substrate 210, so that a portion of the pads PD2, PD4, and PD6 may be exposed by the grooves Gb. In addition, the orthographic projection of the other of each pair of grooves Gb on the circuit substrate 210 may overlap different areas of the pad PD 7. As such, each pair of grooves Gb can be electrically connected to different electrodes of the repaired light emitting element, and can serve as a spare area for repairing the

light emitting element

221, 222, or 223.

For example, in the embodiment, if the light emitting element 222 in the pixel unit X2A needs to be repaired due to misalignment, inclination, or missing, the light emitting element 222A may be disposed in the pair of grooves Gb corresponding to the light emitting element 222 to form a pixel unit like the pixel unit X2b, and the electrode E2A1 of the light emitting element 222A may be located in the groove Gb to be electrically connected to the pad PD2, so that the first distance D21 between the electrode E11 of the light emitting element 221 or the electrode E31 of the light emitting element 223 and the second surface 202 may be greater than the second distance D22 between the electrode E2A1 of the light emitting element 222A and the second surface 202. In the display device 20 of the embodiment, the grooves Gb can be used as alignment marks in the process of disposing the light emitting elements 222A, which is helpful for more accurately and effectively repairing the light emitting elements, thereby improving the production yield of the display device 20.

Fig. 3A is a partial top view of a display device 30 according to an embodiment of the invention. FIG. 3B is a schematic cross-sectional view taken along section line D-D' of FIG. 3A. Referring to fig. 3A to 3B, the display device 30 includes: a circuit substrate 310 having a first surface 301 and a second surface 302 opposite to each other; and a plurality of light emitting elements 320 disposed on the first surface 301 of the circuit substrate 310 and electrically connected to the circuit substrate 310, wherein a first distance D31 exists between the

light emitting elements

321, 322, 323 of the plurality of light emitting elements 320 and the second surface 302, a second distance D32 exists between the light emitting element 322A of the plurality of light emitting elements 320 and the second surface 302, and the first distance D31 is not equal to the second distance D32. In addition, the display device 30 may include a plurality of pixel units PX, and the plurality of pixel units PX may include a pixel unit X3a and a pixel unit X3 b.

In addition, in the embodiment, the circuit substrate 310 of the display device 30 may include a bottom plate 312 and driving

circuit layers

314, 316, 318, wherein the driving

circuit layers

314, 316, 318 may be located between the bottom plate 312 and the light emitting element 320, and the light emitting element 320 may be electrically connected to the driving

circuit layers

314, 316, 318.

The display device 30 shown in fig. 3A to 3B is different from the display device 20 shown in fig. 2A to 2B in that: the pairs of grooves Gc of the display device 30 have a cross shape.

Specifically, in the embodiment, the signal lines SL1, SL2, and SL3 may be disposed in the driving

circuit layers

314, 316, and 318, the pads PD1, PD3, and PD5 may be disposed on the driving circuit layer 318, and the pads PD2, PD4, and PD6 may be disposed in the driving circuit layer 316 on the driving circuit layer 314. The driving circuit layer 318 may have a plurality of pairs of cross-shaped grooves Gc, and an orthogonal projection of one of each pair of grooves Gc on the circuit substrate 310 may overlap the pad PD2, the pad PD4, or the pad PD6, so that a portion of the pads PD2, PD4, and PD6 may be exposed by the grooves Gc. In addition, the orthographic projection of the other of each pair of the grooves Gc on the circuit substrate 310 may overlap different areas of the pad PD 7. As such, each pair of grooves Gc can be electrically connected to different electrodes of the repaired light emitting element, and can serve as a spare area for repairing the

light emitting element

321, 322 or 323.

In this embodiment, if the light emitting element 322 in the pixel unit X3a needs to be repaired due to misalignment, inclination, or omission, the light emitting element 322A may be disposed in the pair of grooves Gc corresponding to the light emitting element 322 to form a pixel unit such as the pixel unit X3b, and the electrode E2A1 of the light emitting element 322A may be located outside the groove Gc, for example, the lateral width of the electrode E2A1 may be greater than the lateral width of the groove Gc, but the electrode E2A1 may be electrically connected to the pad PD2 of the circuit substrate 310 through the conductive material S3 (e.g., conductive adhesive) in the groove Gc, so that the first distance D31 between the electrode E11 of the light emitting element 321 or the electrode E31 of the light emitting element 323 and the second surface 302 may be greater than the second distance D32 between the electrode E2A1 of the light emitting element 322A and the second surface 302. In the display device 30 of the embodiment, the groove Gc can be used as an alignment mark in the process of disposing the light emitting element 322A, which is helpful for repairing the light emitting element more accurately and effectively, thereby improving the production yield of the display device 30.

Fig. 4 is a partial top view of a display device 40 according to an embodiment of the invention. The display device 40 shown in fig. 4 is different from the display device 20 shown in fig. 2A to 2B in that: the display device 40 may include a circuit substrate 410 and a plurality of light emitting elements 420 disposed on the circuit substrate 410, wherein the circuit substrate 410 may include a plurality of common electrodes CM and a plurality of pads PD arranged in parallel, the plurality of light emitting elements 420 may include light emitting

elements

421, 422, 423, one electrode of each of the

light emitting elements

421, 422, 423 may be electrically connected to the pads PD, and the other electrode of each of the

light emitting elements

421, 422, 423 may be electrically connected to the common electrode CM in common.

In addition, a plurality of pairs of triangular grooves Gd1, a plurality of pairs of circular grooves Gd2, and a plurality of pairs of cross-shaped grooves Gd3 may be formed on the surface of the circuit substrate 410 where the

light emitting elements

421, 422, 423 are not disposed, and an orthogonal projection of one of each pair of grooves Gd1, Gd2, Gd3 on the circuit substrate 410 may overlap the pads PD, and an orthogonal projection of the other of each pair of grooves Gd1, Gd2, Gd3 on the circuit substrate 410 may overlap different regions of the common electrode CM. As such, each pair of grooves Gd1, Gd2, Gd3 may be electrically connected to different electrodes of a repaired light-emitting element, and can serve as a spare area for repairing the light-emitting

element

421, 422 or 423.

In this embodiment, the display device 40 may include a plurality of repeating units RU, and the number of the

light emitting elements

421, 422, 423 and the number of pairs of the grooves Gd1, Gd2, Gd3 (i.e. the number of the spare areas) included in each repeating unit RU may be the same or different depending on the arrangement of the

light emitting elements

421, 422, 423 and the grooves Gd1, Gd2, Gd3 on the circuit substrate 410.

For example, in the present embodiment, the repeating unit RU may include four light emitting elements 421, four light emitting elements 422, four light emitting elements 423, two pairs of grooves Gd1, two pairs of grooves Gd2, and two pairs of grooves Gd3, wherein the first to three light emitting elements 421, the first to three light emitting elements 422, and the first to three light emitting elements 423 are arranged in an upper row of the repeating unit RU in a fixed order, the fourth light emitting element 421, the fourth light emitting element 422, and the fourth light emitting element 423 are arranged in a lower row of the repeating unit RU at a fixed pitch, and two groups of grooves Gd1, Gd2, and Gd3 are respectively disposed between two adjacent ones of the fourth light emitting element 421, the fourth light emitting element 422, and the fourth light emitting element 423. That is, the repeating unit RU may include 12 light emitting elements and 6 pairs of grooves (6 spare areas), and the number of spare areas in the repeating unit RU may be smaller than the number of light emitting elements, so that it is possible to avoid providing too many redundant spare areas, thereby improving the utilization rate of the grooves Gd1, Gd2, Gd 3.

Fig. 5A is a partial top view of a display device 50 according to an embodiment of the invention. FIG. 5B is a schematic cross-sectional view taken along section line E-E' of FIG. 5A. Referring to fig. 5A to 5B, the display device 50 includes: a circuit substrate 510 having a first surface 501 and a second surface 502 opposite to each other; a plurality of light emitting elements 520 located on the first surface 501 of the circuit substrate 510 and electrically connected to the circuit substrate 510; and a positioning layer 530 covering the

light emitting elements

521, 522, and 523 of the plurality of light emitting elements 520.

In this embodiment, the circuit substrate 510 of the display device 50 may include a bottom plate 512 and a driving circuit layer 514, wherein the driving circuit layer 514 may be located between the bottom plate 512 and the light emitting element 520, and the light emitting element 520 may be electrically connected to the driving circuit layer 514.

The driving circuit layer 514 may include elements or lines required for the display device 50. For example, in the embodiment, the display device 50 may include a plurality of pixel units PX, and each pixel unit PX may include signal lines SL1, SL2, SL3 in the driving circuit layer 514 and pads PD1, PD2, PD3, PD7 on the driving circuit layer 114, wherein the pad PD1 may be electrically connected to the signal line SL1, the pad PD2 may be electrically connected to the signal line SL2, the pad PD3 may be electrically connected to the signal line SL3, and the pad PD7 may be electrically connected to other signal lines, such as power lines. In the embodiment, the pads PD1, PD2, and PD3 may be located on the same side of the pad PD7, but not limited thereto.

In the present embodiment, the light emitting element 521 of the light emitting elements 520 is, for example, a red light emitting diode, the light emitting element 522 is, for example, a blue light emitting diode, and the light emitting element 523 is, for example, a green light emitting diode. In this way, the

light emitting elements

521, 522 and 523 can together form a pixel unit X5a in the plurality of pixel units PX of the display device 50, wherein the electrode E11 of the light emitting element 521 can be electrically connected to the pad PD1, the electrode E21 of the light emitting element 522 can be electrically connected to the pad PD2, the electrode E31 of the light emitting element 523 can be electrically connected to the pad PD3, and the other electrodes of the

light emitting elements

521, 522 and 523 can be all electrically connected to the pad PD 7.

In this embodiment, the light emitting element 520 may further include a light emitting element 522A, and the light emitting element 522A may have the same light color as the light emitting element 522. In this way, the light-emitting

elements

521, 522A, and 523 can together constitute the pixel cell X5b among the plurality of pixel cells PX of the display device 50.

In this embodiment, the positioning layer 530 may have at least one opening OP. When a transfer failure occurs during the transfer of the

light emitting elements

521, 522, 523, for example, a certain light emitting element 522 is dislocated, tilted, or omitted, the positioning layer 530 may cover the successfully transferred

light emitting elements

521, 522, 523 and form an opening OP at the light emitting element 522 with the transfer failure. The material of the positioning layer 530 may include an optical material, such as a photoresist, so that the positioning layer 530 may also help to adjust the light extraction efficiency of the

light emitting elements

521, 522, 523. In some embodiments, the material of the positioning layer 530 may be Propylene glycol monomethyl ether acetate (Propylene glycol monomethyl ether acetate), Olefin-based resin (Olefin resin), Epoxy resin (Epoxy resin), Naphthoquinone diazide ester (Naphthoquinone diazide ester), Phenol Compound (Phenol Compound), Acid adduct of Bisphenol fluorene Epoxy acrylate (Acid adduct of Bisphenol fluoride Epoxy acrylate), Bisphenol a epichlorohydrin resin (Bisphenol a epichlorohydrin resin), or other suitable materials.

In the present embodiment, the light emitting element 522 with the transfer failure may be removed before the positioning layer 530 is formed, during the formation of the opening OP, or after the formation of the opening OP. Thereafter, the spare light-emitting elements 522A of the light-emitting elements 522 can be disposed in the corresponding openings OP through a repair process, and the orthographic projection of the light-emitting elements 522A on the circuit substrate 510 is within the orthographic projection of the openings OP on the circuit substrate 510, so as to form a pixel unit, such as the pixel unit X1 b. In other words, in the display device 50 of the present embodiment, the light emitting elements 522 with failed transfer can be repaired in situ without reserving a spare area for repair. In some embodiments, the opening OP of the positioning layer 530 may not overlap the

light emitting elements

521, 522, 523, that is, the light emitting element 522A may be ex-situ repaired.

In the embodiment, the electrode E2A1 of the light emitting element 522A may be electrically connected to the pad PD2 of the circuit substrate 510 through a conductive material S5 (e.g., a conductive adhesive), so that the second distance D52 between the electrode E2A1 of the light emitting element 522A and the second surface 502 may be greater than the first distance D51 between the electrode E11 of the light emitting element 521, the electrode E21 of the light emitting element 522, or the electrode E31 of the light emitting element 523 and the second surface 502.

In the embodiment, the pad PD2 electrically connected to the light emitting device 522 with the transfer failure can be left, but is not limited thereto. For example, in some embodiments, the pad PD2 may be further removed in the process of removing the light emitting element 522 with the transfer failure, and the electrode E2A1 of the light emitting element 522A may be electrically connected to the signal line SL2 of the circuit substrate 510 through the conductive material S5.

In the display device 50 of the present embodiment, the opening OP can assist in aligning in the process of repairing the light emitting element 522A, which is helpful for more accurately and effectively repairing the light emitting element, thereby improving the production yield of the display device 50.

In summary, the display device of the present invention assists in aligning or positioning the light emitting device during the repair process by providing the recess on the circuit substrate or providing the opening in the positioning layer, so that the repair of the light emitting device can be performed more accurately and effectively, thereby improving the production yield of the display device.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A display device, comprising:

the circuit substrate is provided with a first surface and a second surface which are opposite; and

a plurality of light emitting elements disposed on the first surface of the circuit substrate and electrically connected to the circuit substrate,

wherein a first pitch exists between a first light emitting element of the plurality of light emitting elements and the second surface, a second pitch exists between a second light emitting element of the plurality of light emitting elements and the second surface, and the first pitch is not equal to the second pitch.

2. The display device of claim 1, wherein the first pitch is greater than the second pitch.

3. The display device of claim 1, wherein the first surface has a plurality of grooves.

4. The display device of claim 3, wherein the second light emitting element is located in the recess.

5. The display device according to claim 3, wherein an electrode of the second light-emitting element is located in the groove.

6. The display device according to claim 3, wherein an electrode of the second light-emitting element is located outside the groove, and the electrode of the second light-emitting element is electrically connected to the circuit substrate through a conductive paste.

7. A display device as claimed in claim 3, wherein the recess is square, circular, cross-shaped or triangular in shape.

8. The display device according to claim 1, further comprising a positioning layer covering the first light emitting element.

9. The display device according to claim 8, wherein the positioning layer has an opening, and an orthographic projection of the second light-emitting element on the circuit substrate is within an orthographic projection of the opening on the circuit substrate.

10. The display device according to claim 8, wherein a material of the positioning layer is propylene glycol monomethyl ether acetate, an olefin-based resin, an epoxy resin, diazonaphthoquinone ester, a phenol compound, an acid adduct of bisphenol fluorene epoxy acrylate, or bisphenol a epichlorohydrin resin.

11. A display device, comprising:

a circuit substrate;

a plurality of light emitting elements located on the circuit substrate and electrically connected to the circuit substrate; and

a positioning layer covering a first light emitting element of the plurality of light emitting elements.

12. The display device according to claim 11, wherein the positioning layer has an opening, and an orthogonal projection of a second light-emitting element of the plurality of light-emitting elements on the circuit substrate is within an orthogonal projection of the opening on the circuit substrate.

13. The display device according to claim 12, wherein the second light-emitting element is electrically connected to the circuit substrate through a conductive paste.

14. The display device according to claim 11, wherein a material of the positioning layer is propylene glycol monomethyl ether acetate, an olefin-based resin, an epoxy resin, diazonaphthoquinone ester, a phenol compound, an acid adduct of bisphenol fluorene epoxy acrylate, or bisphenol a epichlorohydrin resin.