Display device and method of manufacturing the same

Abstract

A display device is provided. The display device includes: a plurality of anode pads disposed on a substrate and spaced apart from each other along a first direction; a cathode pad disposed on the substrate and spaced apart from the plurality of anode pads along a second direction intersecting the first direction; a plurality of repair anode pads disposed on the substrate, spaced apart from each other along the first direction, and spaced apart from the plurality of anode pads and cathode pads along the second direction; and a plurality of light-emitting diodes (LEDs) disposed on the substrate and spaced apart from each other along the first direction, each of the plurality of LEDs including an anode electrically connected to a corresponding anode pad among the plurality of anode pads and a cathode electrically connected to a cathode pad.

Description

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2019-0097309, filed on August 9, 2019, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a display device capable of displaying images using inorganic light-emitting diodes and a method for manufacturing the same. Background Technology

[0004] Display devices can be classified into self-emissive displays in which each pixel emits light, and non-self-emissive displays that require a separate light source.

[0005] The liquid crystal displays (LCDs) that are still widely used are typical non-emissive displays and require a backlight to provide light from the back of the display panel, a liquid crystal layer that acts as a switch to transmit / block light, and a color filter to change the provided light into the desired color. The large number of components results in a complex structure and limitations in achieving a small thickness.

[0006] On the other hand, in self-emissive displays, each pixel emits its own light and includes, for example, a light-emitting diode (LED). Self-emissive displays do not require backlighting, liquid crystal layers, or color filters. In this respect, the structure of self-emissive displays can have reduced complexity, and they offer a high degree of design freedom. Furthermore, self-emissive displays can achieve smaller thickness, better contrast, higher brightness, and better viewing angles.

[0007] Micro-LED display panels are examples of self-emissive displays and consist of multiple inorganic light-emitting diodes (inorganic LEDs) of 100 micrometers or smaller. Compared to liquid crystal display panels that require backlighting, micro-LED display panels offer better contrast, response time, and energy efficiency. Both organic light-emitting diodes (OLEDs) and inorganic micro-LEDs have good energy efficiency, but inorganic micro-LEDs offer higher brightness, better luminous efficiency, and longer lifespan compared to OLEDs. Summary of the Invention

[0008] A display device and a method for manufacturing the same are provided. The display device can reduce the pixel size and achieve high resolution by optimizing the arrangement between light-emitting diodes (LEDs) that form pixels and electrode pads electrically connected to the LEDs.

[0009] The embodiments of this disclosure overcome the above-described disadvantages and other disadvantages not described above. Furthermore, this disclosure does not need to overcome the above-described disadvantages, and the embodiments of this disclosure may not overcome any of the above-described problems. Additional aspects of this disclosure will be set forth in part in the description which follows, and will be apparent in part from the description, or may be learned by practicing this disclosure.

[0010] According to one aspect of this disclosure, a display device includes: a substrate; a plurality of anode pads disposed on the substrate and spaced apart from each other along a first direction; at least one cathode pad disposed on the substrate and spaced apart from the plurality of anode pads along a second direction intersecting the first direction; a plurality of repair anode pads disposed on the substrate, spaced apart from each other along the first direction, and spaced apart from the plurality of anode pads and at least one cathode pad along the second direction; and a plurality of light-emitting diodes (LEDs) disposed on the substrate and spaced apart from each other along the first direction, each of the plurality of LEDs including an anode electrically connected to a corresponding anode pad among the plurality of anode pads and a cathode electrically connected to at least one cathode pad.

[0011] At least one cathode pad may include a single cathode pad that is commonly connected to the cathode of each of the multiple LEDs.

[0012] At least one cathode pad may be located between multiple anode pads and multiple repair anode pads.

[0013] At least one cathode pad may include a shared cathode pad that is commonly connected to the cathodes of at least two of the plurality of LEDs.

[0014] The plurality of LEDs may include red LEDs, green LEDs and blue LEDs, and at least one cathode pad may include: a first cathode pad electrically connected to the cathodes of the green LEDs and the blue LEDs; and a second cathode pad electrically connected to the cathode of the red LEDs.

[0015] A first reference voltage can be provided to the first cathode pad, and a second reference voltage higher than the first reference voltage can be provided to the second cathode pad.

[0016] The display device may include an upper insulating layer disposed on a plurality of anode pads and a plurality of repair anode pads. Connecting holes may be formed through the upper insulating layer to expose the plurality of anode pads and the plurality of repair anode pads.

[0017] The anode of each of the multiple LEDs can be electrically connected to the corresponding anode pad exposed through the connection hole.

[0018] The display device may include a repair LED corresponding to the defective LED. The repair anode pads, among a plurality of repair anode pads, corresponding to the defective LED may be electrically connected to the repair LED and exposed through connection holes.

[0019] Each of the multiple LEDs can be configured to emit light backwards from the substrate.

[0020] One of the multiple anode pads can be electrically connected to one of the multiple repair anode pads.

[0021] According to one aspect of this disclosure, a display device includes: a substrate; a plurality of anode pads disposed on the substrate and spaced apart from each other along a first direction; at least one cathode pad disposed on the substrate and spaced apart from the plurality of anode pads along a second direction intersecting the first direction; at least one repair cathode pad disposed on the substrate and spaced apart from the plurality of anode pads and the at least one cathode pad along the second direction; and a plurality of light-emitting diodes (LEDs) disposed on the substrate and spaced apart from each other along the first direction, each of the plurality of LEDs including an anode electrically connected to a corresponding anode pad among the plurality of anode pads and a cathode electrically connected to the at least one cathode pad. The plurality of anode pads may be located between the at least one cathode pad and the at least one repair cathode pad.

[0022] The display device may include: a plurality of driving transistors disposed on the upper side of a substrate and corresponding to a plurality of LEDs respectively. Each of the plurality of anode pads may be electrically connected to the drain of the corresponding driving transistor among the plurality of driving transistors, and at least one cathode pad may be connected to a reference voltage.

[0023] The display device may include an upper insulating layer disposed on a plurality of anode pads, at least one cathode pad, and at least one repair cathode pad. Connecting holes may be formed through the upper insulating layer to expose the plurality of anode pads, at least one cathode pad, and at least one repair cathode pad.

[0024] The anode of each of the plurality of LEDs may be electrically connected to a plurality of anode pads exposed through a connection hole, and the cathode of each of the plurality of LEDs may be electrically connected to at least one cathode pad exposed through a connection hole.

[0025] The display device may include a repair LED corresponding to a defective LED. The cathode of the repair LED may be electrically connected to at least one repair cathode pad corresponding to the defective LED, the at least one repair cathode pad being exposed through a connection hole, and the anode of the repair LED may be electrically connected to a corresponding anode pad among a plurality of anode pads corresponding to the defective LED, the corresponding anode pad being exposed through a connection hole.

[0026] The display device may include a plurality of driving transistors disposed on the upper side of a substrate and corresponding to a plurality of LEDs respectively. At least one cathode pad may be electrically connected to the drain of each of the plurality of driving transistors, and the plurality of anode pads may be connected to a power supply voltage.

[0027] The power supply voltage may include a first power supply voltage and a second power supply voltage lower than the first power supply voltage. The multiple LEDs may include a red LED, a green LED, and a blue LED. The first power supply voltage may be provided to the anode of the green LED and the anode of the blue LED, while the second power supply voltage may be provided to the anode of the red LED.

[0028] One of at least one cathode pads may be electrically connected to one of at least one repair cathode pads.

[0029] According to one aspect of this disclosure, a method of manufacturing a display device includes: providing a plurality of anode pads on a substrate, the plurality of anode pads being spaced apart from each other along a first direction; providing at least one cathode pad on the substrate, the at least one cathode pad being spaced apart from the plurality of anode pads along a second direction intersecting the first direction; providing a plurality of repair anode pads on the substrate, the plurality of repair anode pads being spaced apart from each other along the first direction and spaced apart from the plurality of anode pads and at least one cathode pad along the second direction; forming an upper insulating layer on the plurality of anode pads, at least one cathode pad, and the plurality of repair anode pads; forming a connection hole through the upper insulating layer to expose the plurality of anode pads, at least one cathode pad, and the plurality of repair anode pads; and providing a plurality of light-emitting diodes (LEDs) on the substrate, the plurality of LEDs being spaced apart from each other along the first direction, each of the plurality of LEDs including an anode and a cathode.

[0030] The manufacturing method may include: electrically connecting the anode of each of a plurality of LEDs to a corresponding anode pad among a plurality of anode pads exposed through a connection hole; and electrically connecting the cathode of each of the plurality of LEDs to at least one cathode pad exposed through a connection hole.

[0031] Connecting the anode of each of a plurality of LEDs to a corresponding anode pad may include: forming an anisotropic conductive film on an upper insulating layer; compressing the anode of the LEDs in the plurality of LEDs at a position on the anisotropic conductive film corresponding to the corresponding anode pad; and heating the anisotropic conductive film.

[0032] One of the multiple anode pads can be electrically connected to one of the multiple repair anode pads.

[0033] According to one aspect of this disclosure, a display device includes: a first plurality of connection pads formed on a substrate, the first plurality of connection pads being spaced apart from each other along a first direction; a second plurality of connection pads formed on the substrate, the second plurality of connection pads being spaced apart from each other along the first direction and spaced apart from the first plurality of connection pads along a second direction intersecting the first direction, one of the first plurality of connection pads being electrically connected to one of the second plurality of connection pads; a third plurality of connection pads formed on the substrate, the third plurality of connection pads being spaced apart from each other along the first direction and spaced apart along the second direction between the first plurality of connection pads and the second plurality of connection pads; and a first light-emitting diode (LED) disposed on and electrically connected to the first and third plurality of connection pads, wherein the first LED is offset from the second plurality of connection pads along the first and second directions.

[0034] The display device may include: a second LED disposed on and electrically connected to another connection pad in a first plurality of connection pads; and a repair LED disposed on and electrically connected to another connection pad in a second plurality of connection pads and another connection pad in a third plurality of connection pads. The other connection pad in the first plurality of connection pads may be electrically isolated from the other connection pad in the second plurality of connection pads.

[0035] The second LED may be a defective LED.

[0036] The display device may include an insulating layer formed on a first plurality of connection pads, a second plurality of connection pads, and a third plurality of connection pads. One of the second plurality of connection pads may be exposed through the insulating layer. Attached Figure Description

[0037] The above and other aspects, features, and advantages of certain embodiments will become apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0038] Figure 1 This is a perspective view showing an example of a display device according to an embodiment;

[0039] Figure 2 This is a view showing an example of pixels forming a unit module of a display device according to an embodiment;

[0040] Figure 3This is a schematic diagram illustrating a thin-film transistor (TFT) driver circuit for individually driving each pixel of a display device according to an embodiment;

[0041] Figure 4 This is a side cross-sectional view of a sub-pixel of a display device according to an embodiment;

[0042] Figure 5 This is a plan view showing the anode pads and cathode pads of the display device according to an embodiment, viewed from above;

[0043] Figure 6 This is a view illustrating an example of a method for electrically connecting an anode pad and a cathode pad to an inorganic light-emitting diode (inorganic LED) in a display device according to an embodiment;

[0044] Figure 7 This is a schematic diagram illustrating an example of a method for electrically connecting an anode pad and a cathode pad to an inorganic LED in a display device according to an embodiment;

[0045] Figure 8 This is a view showing the pad structure of a single repair LED in a display device according to an embodiment, as viewed from above;

[0046] Figure 9 This is a side cross-sectional view showing the pad structure of a single repair LED in a display device according to an embodiment;

[0047] Figure 10 This is a side cross-sectional view showing the pad structure of a single repair LED in a display device according to an embodiment;

[0048] Figure 11 This is a side cross-sectional view showing the pad structure of a single repair LED in a display device according to an embodiment;

[0049] Figure 12 This is a circuit diagram showing a sub-pixel circuit connected to a repair LED in a display device according to an embodiment;

[0050] Figure 13 It is a planar diagram showing the structure of a single pixel, consisting of red, green, and blue sub-pixels, when viewed from above;

[0051] Figure 14 It is a planar diagram showing the structure of a single pixel, consisting of red, green, and blue sub-pixels, when viewed from above;

[0052] Figure 15 It is a planar diagram showing the structure of a single pixel, consisting of red, green, and blue sub-pixels, when viewed from above;

[0053] Figure 16 It is a planar diagram showing the structure of a single pixel, consisting of red, green, and blue sub-pixels, when viewed from above;

[0054] Figure 17 It is a planar diagram showing the structure of a single pixel, consisting of red, green, and blue sub-pixels, when viewed from above;

[0055] Figure 18 This is a side cross-sectional view showing the separation of the cathode pad connected to the main LED and the cathode pad for repairing the LED in a display device according to an embodiment;

[0056] Figure 19 This shows what it looks like when viewed from above. Figure 18 A plan view of the structure;

[0057] Figure 20 This is a side cross-sectional view showing the main LED and the repair LED sharing an anode pad in a display device according to an embodiment;

[0058] Figure 21 It shows Figure 20 Circuit diagram of the sub-pixel structure;

[0059] Figure 22 This shows what it looks like when viewed from above. Figure 20 A view of the structure;

[0060] Figure 23 It shows what it looks like when viewed from above. Figure 20 A view of the structure;

[0061] Figure 24 This is a circuit diagram illustrating a sub-pixel circuit in a display device according to an embodiment, in which an NMOS transistor is used as a driving transistor and the power supply voltage V... DD It is applied directly to the LED;

[0062] Figure 25 When the application Figure 24 A side cross-sectional view of the circuit structure;

[0063] Figure 26 This is a flowchart illustrating a method for manufacturing a backplate in a method for manufacturing a display device according to an embodiment;

[0064] Figure 27 This is a flowchart illustrating a method for transferring an LED to a backplane and testing the LED in a method for manufacturing a display device according to an embodiment;

[0065] Figure 28This is a flowchart illustrating another method for manufacturing a backplate in a method for manufacturing a display device according to an embodiment; and

[0066] Figure 29 This is a flowchart illustrating another method for transferring an LED to a backplane and testing the LED in a method for manufacturing a display device according to an embodiment. Detailed Implementation

[0067] Throughout the following description, similar reference numerals refer to similar elements. Well-known functions or constructions may not be described in detail, as they would obscure one or more embodiments with unnecessary detail. Terms such as “unit,” “module,” “component,” and “block” can be specifically implemented in hardware or software. According to embodiments, multiple “units,” “modules,” “components,” and “blocks” may be implemented as a single component, or a single “unit,” “module,” “component,” and “block” may include multiple components.

[0068] It will be understood that when one element is referred to as being “connected” to another element, it can be directly or indirectly connected to the other element, where indirect connection includes “connection via a wireless communication network” or “electrical connection via a wire”.

[0069] Furthermore, when a component “contains” or “includes” an element, the component may also include other elements without excluding them, unless otherwise specifically described to the contrary.

[0070] Throughout the specification, when one component is "on" another component, this includes not only the case where the component is in contact with the other component, but also the case where there is another component between the two components.

[0071] Throughout this specification, when one component transmits or transfers signals or data to another component, it should be noted that there is another component between that component and the other component, and that the signals or data are transmitted or transferred through that component, unless there is a specific description to the contrary.

[0072] It should be understood that while the terms “first” or “first” and “second” or “second” can be used to modify corresponding components, regardless of their importance or order, these terms are used to distinguish one component from another without limiting the components.

[0073] As used in this article, the singular forms “a,” “one,” and “the” also mean the plural forms, unless the context clearly indicates otherwise.

[0074] For ease of description, identifiers are used, but these identifiers are not intended to indicate the order of each operation. Unless the context explicitly indicates otherwise, each operation may be performed in a different order than that shown.

[0075] In the following, embodiments of the display device and its manufacturing method will be described in detail with reference to the accompanying drawings.

[0076] Figure 1 This is a perspective view showing an example of a display device according to an embodiment, and Figure 2 This is a view showing an example of pixels forming a unit module of a display device according to an embodiment.

[0077] The display device according to the embodiment is a self-emissive display device, wherein a light-emitting diode (LED) is provided for each pixel, so that each pixel emits light on its own. Therefore, unlike liquid crystal display (LCD) devices, since components such as backlight units, liquid crystal layers, and polarizers are not required, a smaller thickness can be achieved, and the design may differ due to the reduced structural complexity.

[0078] Furthermore, the display device according to the embodiment can employ inorganic light-emitting devices such as light-emitting diodes (LEDs) as the light-emitting devices disposed in each pixel. Inorganic light-emitting devices have a faster response speed than organic light-emitting devices such as organic light-emitting diodes (OLEDs) and can achieve high brightness with low power. In addition, compared with OLEDs, which require encapsulation processes, are susceptible to water and oxygen, and have poor durability, inorganic LEDs do not require encapsulation processes and have better durability.

[0079] The inorganic light-emitting device used in the display device according to the embodiment can be a micro-LED with a short side length of about 125 μm. As described above, by employing micro-unit LEDs, pixel size can be reduced and pixel density increased to achieve high resolution.

[0080] Display devices using micro-LEDs can be applied to various fields due to their ultra-small pixel size and thinness. For example, ... Figure 1 As shown, a large-area screen can be achieved by tiling multiple unit modules 10 and mounting the multiple unit modules 10 to the housing 21, wherein each unit module 10 includes multiple micro LEDs mounted on a substrate.

[0081] in addition, Figure 1The three-dimensional coordinate system shown in the diagram is based on display device 1. The plane in which the screen of display device 1 is located is the XZ plane, and the direction of the output image or the light emitted by the inorganic light-emitting device is the +Y direction. Because the coordinate system is based on display device 1, the same coordinate system can be applied to display device 1 regardless of its orientation.

[0082] refer to Figure 2 The unit module 10 may have a pixel structure of an M×N array (M and N are integers of 2 or greater), and the unit pixel P may consist of three sub-pixels such as red sub-pixel SP(R), green sub-pixel SP(G) and blue sub-pixel SP(B), which correspond to red R, green G and blue B.

[0083] However, Figure 1 and Figure 2 The structure described is merely an example that can be applied to the display device 1 according to the embodiment, and the embodiment is not limited to a display device manufactured by tiling multiple unit modules 10. Therefore, the display device 1 can be a display device having an M×N pixel array without employing a tiling process.

[0084] Furthermore, the embodiments are not limited to a unit pixel P consisting of a red sub-pixel SP(R) configured to emit red light, a green sub-pixel SP(G) configured to emit green light, and a blue sub-pixel SP(B) configured to emit blue light. Therefore, a unit pixel P may include a sub-pixel configured to emit yellow light and a sub-pixel configured to emit white light.

[0085] For convenience, in the embodiments described below, unit pixel P will be described as including a red sub-pixel SP(R) configured to emit red light, a green sub-pixel SP(G) configured to emit green light, and a blue sub-pixel configured to emit blue light.

[0086] Figure 3 This is a schematic diagram illustrating a thin-film transistor (TFT) driver circuit for individually driving each pixel of a display device according to an embodiment. Figure 4 This is a side cross-sectional view of a sub-pixel of a display device according to an embodiment, while Figure 5 This is a plan view showing the anode pads and cathode pads of the display device according to an embodiment, as viewed from above.

[0087] refer to Figure 3 Multiple data lines DL and power lines VL arranged in the column direction, and gate lines GL arranged in the row direction, can be configured as electrode patterns. The area divided by the data lines DL and gate lines GL corresponds to the sub-pixel SP.

[0088] The data line DL transmits the data signals used to realize the image to the sub-pixel SP, and the gate line GL transmits the scan signals used to turn the sub-pixel on / off to the sub-pixel SP. The power line VL provides the power supply voltage V to the sub-pixel within a time corresponding to a single frame. DD .

[0089] When the scan driver 130 applies a scan signal to the gate line GL, the sub-pixel SP connected to the gate line GL to which the scan signal is applied can be turned on, and when the data driver 140 applies voltage data VDATA corresponding to the image signal to the data line DL, the data voltage VDATA can be input to the turned-on sub-pixel connected to the data line DL.

[0090] Scan driver 130 and data driver 140 can be electrically connected to backplane 100 (reference). Figure 4 For example, the scan driver 130 and the data driver 140 can be mounted on the backplane 100 in the form of chips mounted on a tape-on-a-chip (TCP), flexible printed circuit (FPC), or thin film. Alternatively, the scan driver 130 and the data driver 140 can be mounted directly on the underside of the backplane 100.

[0091] A light-emitting diode (LED) 300 configured to provide light to the corresponding sub-pixel can be provided for each sub-pixel. The thin-film transistor (TFT) driver circuit configured to drive the LED 300 may include a switching transistor 200', a driving transistor 200, and a capacitor 201.

[0092] Both the switching transistor 200' and the driving transistor 200 can be implemented as PMOS transistors. However, embodiments of the display device are not limited to this, and one or both of the switching transistor 200' and the driving transistor 200 can be implemented as NMOS transistors.

[0093] The gate of the switching transistor 200' can be connected to the gate line GL, the source can be connected to the data line DL, and the drain can be connected to one end of the capacitor 201 and the gate of the driving transistor 200. The other end of the capacitor 201 can be connected to the power line VL.

[0094] Additionally, the source of the driving transistor 200 can be connected to the power supply line VL, while the drain can be connected to the anode 310 of the LED 300 (see reference). Figure 6 The cathode of LED 300 is 320 (reference). Figure 6 It can be connected to the reference voltage V. SS Reference voltage V SS It can be below the power supply voltage V DDThe voltage level, and the ground voltage can be used as a reference voltage V. SS .

[0095] The sub-pixel including the above structure can operate as follows. First, when a scan signal is applied to the gate line GL to turn on the switching transistor 200', the data voltage VDATA applied to the data line DL can be applied to one end of the capacitor 201 and the gate of the driving transistor 200. The voltage corresponding to the gate-source voltage VGS of the driving transistor 200 can be maintained for a predetermined time by the capacitor 201. The driving transistor 200 can make the LED 300 emit light by applying a driving current IGS corresponding to the gate-source voltage VGS to the anode 310 of the LED 300.

[0096] At this time, when a high data voltage VDATA is transmitted to the gate of the driving transistor 200, the gate-source voltage VGS of the driving transistor 200 may decrease, thus a small amount of drive current IGS may be applied to the anode 310 of the LED 300. Therefore, the LED 300 can display a low grayscale. On the other hand, when a low data voltage VDATA is transmitted, the gate-source voltage VGS of the driving transistor 200 may increase, thus a large amount of drive current IGS can be applied to the anode 310 of the LED 300. Therefore, the LED 300 can display a high grayscale.

[0097] refer to Figure 4 A buffer layer 103 may be formed on the substrate 101, and a driving transistor 200 may be disposed on the buffer layer 103. The upper side of the substrate 101 may indicate the +Y direction. The side section according to this embodiment and the embodiments described below may be located on the XY plane or the ZY plane.

[0098] The substrate 101 can be formed from various materials. For example, the substrate 101 can be formed from a transparent glass material containing SiO2 as the main component. Alternatively, the substrate 101 can be formed from a transparent plastic material, thus allowing the substrate 101 to be flexible. As another alternative, the substrate 101 can be formed from a metallic material.

[0099] The plastic material forming the substrate 101 can be an insulating organic material selected from the group consisting of: polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene terephthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallyl ester, polyimide, polycarbonate (PC), cellulose triacetate (TAC), and cellulose acetate propionate (CAP).

[0100] The metal forming the substrate 101 can be selected from the group consisting of iron, chromium, manganese, nickel, titanium, molybdenum, stainless steel (SUS), Invar alloy, Incol nickel alloy and Kovar alloy.

[0101] The buffer layer 103 may provide a flat surface on the upper side of the substrate 101 and may prevent foreign matter or moisture from penetrating the substrate 101. For example, the buffer layer 103 may be formed of inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, titanium oxide, or titanium nitride, or organic materials such as polyimide, polyester, or acrylic acid. Alternatively, the buffer layer 103 may comprise multiple layers of the above-described materials.

[0102] The driving transistor 200 disposed on the buffer layer 103 may include an active layer 210, a gate 220, a drain 230, and a source 240. The active layer 210 may be formed of a semiconductor material, and the active layer 210 may include a source region 210a, a drain region 210b, and a channel region 210c between the source region and the drain region.

[0103] The gate 220 may be formed on the upper side of the active layer 210 to correspond to the channel region 210c. The source 240 and drain 230 may be electrically connected to the source region 210a and drain region 210b of the active layer 210, respectively. According to an embodiment, the driving transistor 200 is implemented as a top-gate type, wherein the gate 220 is disposed on the upper side of the active layer 210. However, the embodiment is not limited to this, and the gate 220 may be disposed on the lower side of the active layer 210.

[0104] A first insulating layer 111, formed of an inorganic insulating material, can be disposed between the active layer 210 and the gate 220. A second insulating layer 112 can be disposed on the gate 220. The first insulating layer 111 can be a gate insulating layer, and the second insulating layer 112 can be an interlayer insulating layer. In this embodiment, one component being disposed on top of another component can not only represent a structure where all components are located above other components, but also a structure where one component surrounds or covers all or part of another component. Furthermore, the fact that one component covers another component can not only represent a structure where one component covers all other components, but also a structure where a hole is formed in one component and a portion of another component is exposed through the corresponding hole.

[0105] Therefore, a gate insulating layer 111 can be formed on the buffer layer 103 on which the active layer 210 is disposed to cover the active layer 210. An interlayer insulating layer 112 can be formed on the gate insulating layer 111 on which the gate 220 is disposed to cover the gate 220.

[0106] Source 240 and drain 230 can be disposed on interlayer insulating layer 112. Holes can be formed through interlayer insulating layer 112 and gate insulating layer 111 at locations corresponding to source 240 and drain 230. Source 240 and drain 230 can be electrically connected to source region 210a and drain region 210b of active layer 210, respectively, through these holes. In this embodiment, "electrical connection" can refer not only to the case of directly welding conductive materials through which current flows, but also to the case where conductive materials are disposed between layers through which current flows (e.g., anisotropic conductive film (ACF)) when the conductive materials are connected by separate wires. That is, there is no limitation on the specific connection method, as long as current flows between two components in contact with each other. Furthermore, in the embodiments described below, connections between certain components may include electrically connecting the components.

[0107] The third insulating layer 113 can be disposed on the interlayer insulating layer 112 on which the source electrode 240 and the drain electrode 230 are disposed. The third insulating layer 113 can be a planarization layer. The planarization layer 113 can be disposed on the interlayer insulating layer 112 and can cover the source electrode 240, the drain electrode 230 and the interlayer insulating layer 112.

[0108] Anode pad 410 connected to anode 310 of LED 300 (reference) Figure 6 ) and cathode pad 420 connected to cathode 320 of LED 300 (reference) Figure 6 The electrode pads 410 and 420 can be disposed on the planarization layer 113. In this embodiment, the anode pad 410 and cathode pad 420 can refer to electrode pads formed of a conductive material such as metal and exposed from the insulating layer for electrical connection with other electrodes. In the embodiments described below, the term pad is used only for the electrode pads on the backplane 100 side, while the electrode pads on the LED side are referred to as anode and cathode.

[0109] A hole can be formed in the interlayer insulating layer 113 at a position corresponding to the drain 230, and the anode pad 410 can be electrically connected to the drain 230 through this hole. The source 240 can be connected to a power line VL, to which a power supply voltage V is supplied. DD Furthermore, gate 220 can be connected to the line that supplies the data voltage VDATA to it.

[0110] Cathode pad 420 can be connected to reference voltage V SS This is to ground the LED 300 connected to the cathode pad 420.

[0111] The upper insulating layer 114 can be disposed on the interlayer insulating layer 113 on which the anode pad 410 and the cathode pad 420 are disposed. The upper insulating layer 114 can cover the interlayer insulating layer 113, the anode pad 410 and the cathode pad 420.

[0112] In this embodiment, the insulating layer disposed on the upper side of the substrate 101 can be formed of organic insulating material or inorganic insulating material, or can be formed by alternating organic insulating material and inorganic insulating material.

[0113] refer to Figure 4 and Figure 5 The connection hole 114H can be formed by the upper insulating layer 114 covering the anode pad 410 and the upper insulating layer 114 covering the cathode pad 420.

[0114] Anode pad 410 and cathode pad 420 can be exposed through connection hole 114H formed through upper insulating layer 114, and anode 310 and cathode 320 of LED 300 can be electrically connected to anode pad 410 and cathode pad 420 exposed through connection hole 114H.

[0115] The structure from the substrate 101 to the upper insulating layer 114 can be referred to as the back plate 100, and the unit module 10 of the display device 1 can be manufactured by transferring the LED 300 to the upper side of the back plate 100.

[0116] Figure 6 and Figure 7 This is a view illustrating an example of a method for electrically connecting an anode pad and a cathode pad to an inorganic light-emitting diode (inorganic LED) in a display device according to an embodiment.

[0117] refer to Figure 6 The LED 300 may include a pn diode, an anode 310, and a cathode 320. The anode 310 and cathode 320 may be formed of various conductive materials, such as metals, conductive oxides, and conductive polymers. The anode 310 may be electrically connected to the anode pad 410 of the backplane 100, and the cathode 320 may be electrically connected to the cathode pad 420 of the backplane 100.

[0118] A pn diode may include a p-doped portion 330 on the anode side 310, an n-doped portion 370 on the cathode side 320, and a quantum well between the p-doped portion 330 and the n-doped portion 370. Alternatively, an inorganic LED may be used, wherein the doped portion on the cathode side 320 is a p-doped portion, and the doped portion on the anode side 310 is an n-doped portion.

[0119] Furthermore, the display device 1 according to the embodiment is a front-emitting display device, wherein light is emitted in the opposite direction to the substrate 101. Therefore, a driving current can be applied to the anode 310 of the LED 300 through the anode pad 410, and when the current flows from the anode 310 to the cathode 320, the LED 300 can emit light in the opposite direction to the substrate 101 (i.e., the +Y direction).

[0120] As mentioned above, electrical connections between electrodes can be achieved using various bonding methods. For example, a bonding method using anisotropic conductive films (ACFs) can be applied.

[0121] refer to Figure 7 An anisotropic conductive film (ACF) 120 can be disposed on an upper insulating layer 114, wherein a connection hole 114H is formed through the upper insulating layer 114. ACF 120 can be manufactured by uniformly dispersing conductive particles in a viscous organic material with insulating properties and by fabricating ACF 120 in the form of a thin film. Specifically, ACF 120 is conductive in the thickness direction of the film and insulating in the surface direction.

[0122] When the ACF 120 is heated and the LED 300 is compressed onto the ACF 120, the ACF 120 can become conductive, allowing current to flow in the thickness direction of the pressure-bearing film. For example, because the LED applies pressure to the ACF 120 at locations corresponding to the holes 114H, the ACF 120 can become conductive at those locations. Therefore, the ACF 120 can electrically connect the anode 310 of the LED 300 to the anode pad 410, and can electrically connect the cathode 320 of the LED 300 to the cathode pad 420. If no pressure is applied to the portion of the ACF 120 between the holes 114H, that portion will not become conductive.

[0123] As described above, LED 300 can be implemented as a micro LED, and multiple LEDs can be picked up from the wafer by a transport mechanism and then transferred to substrate 101, particularly a backplane. Multiple LEDs can be transferred to the backplane simultaneously by compressing multiple LEDs at once on ACF 120.

[0124] However, the electrical connection between the LED 300 and the backplane 100 is not limited to the bonding method via ACF 120. Alternatively, the LED 300 can also be electrically connected to the anode pad 410 and the cathode pad 420 by soldering with metallic ink (e.g., silver (Ag), gold (Au), or copper (Cu)).

[0125] After the LED 300 is transferred to the backplate 100, testing can be performed to identify whether the LED 300 is defective. As a result of the testing, when a defect is found (e.g., the LED 300 transferred to the backplate does not emit light normally), a repair inorganic LED 300' corresponding to the defective LED 300 can be installed on the backplate 100.

[0126] The repair LED emits the same color as the defective LED 300. For example, if the defective LED 300 is a red inorganic LED, the repair LED will also be a red inorganic LED; if the defective LED 300 is a green inorganic LED, the repair LED will also be a green inorganic LED; and if the defective LED 300 is a blue inorganic LED, the repair LED will also be a blue inorganic LED.

[0127] In order to install a repair LED in response to the occurrence of a defective LED 300, an area for installing the repair LED 300 can be provided on the back plate 100. The structure related thereto will be described in detail below.

[0128] Figure 8 This is a view showing the pad structure of a single repair LED in a display device according to an embodiment, as viewed from above. Figures 9 to 11 This is a side cross-sectional view showing the pad structure of a single repair LED in a display device according to an embodiment, and Figure 12 This is a circuit diagram showing a sub-pixel circuit connected to a repair LED in a display device according to an embodiment.

[0129] In this embodiment, the case where the plane of LED 300 is implemented as a rectangular shape extending in a first direction and a second direction will be described as an example. For example, the first direction may correspond to the width W (i.e., the width direction) of the rectangular shape, and the second direction may correspond to the length L (i.e., the length direction) of the rectangular shape. The first and second directions may be parallel to the XZ plane. The first direction may correspond to either the X direction or the Z direction. The second direction may correspond to the other of the X direction or the Z direction. Width and length are parameters that are perpendicular to each other, and the longer parameter indicates the length L, while the shorter parameter indicates the width W. As shown, the anode 310 of LED 300 is disposed at one end of LED 300 in the length direction, while the cathode 320 of LED 300 is disposed at the other end of LED 300 in the length direction.

[0130] However, the embodiments are not limited thereto, and the LED 300 can have various planar shapes, such as hexagonal, octagonal or elliptical.

[0131] refer to Figure 8 The repair anode pad 430 corresponding to LED 300 can be disposed on the opposite side of anode pad 410 with respect to cathode pad 420. That is, cathode pad 420 can be located between anode pad 410 and repair anode pad 430. If LED 300 is determined to be defective, repair LED 300' can be placed on repair anode pad 430 and electrically connected to repair anode pad 430.

[0132] Figure 9It is along Figure 8 The backplate structure shown is a side cross-sectional view taken along line A-A'.

[0133] refer to Figure 9 As described above, the repair anode pad 430 can be disposed on the planarization layer 113, and the cathode pad 420 can be located between the anode pad 410 and the repair anode pad 430.

[0134] The upper insulating layer 114 can be disposed on the planarization layer 113, on which the anode pad 410, the cathode pad 420 and the repair anode pad 430 are disposed, and a connection hole 114H can be formed through the upper insulating layer 114 to expose the anode pad 410, the cathode pad 420 and the repair anode pad 430 respectively.

[0135] By using various bonding methods (e.g., bonding using ACF 120 and bonding using soldering), the anode 310 of the LED 300 can be electrically connected to the anode pad 410, and the cathode 320 of the LED 300 can be electrically connected to the cathode pad 420, such as... Figure 10 As shown in the image.

[0136] If LED 300 is found to be defect-free after testing, the display device 1 can be completed without connecting the repair LED 300'. If LED 300 is found to be defective, the repair LED 300' can be electrically connected to the back panel 100, such as... Figure 11 As shown in the diagram. The repair LED 300' can have the same structure as LED 300. Therefore, a detailed description of the structure of the repair LED 300' will be omitted.

[0137] In the embodiments described below, LED 300 will be referred to as main LED 300 to distinguish it from repair LED 300'.

[0138] The anode 310' of the repair LED 300' can be electrically connected to the repair anode pad 430, while the cathode 320' of the repair LED 300' can be electrically connected to the cathode pad 420. That is, in this example, the repair LED 300' and the main LED 300 can share the cathode pad 420. The associated sub-pixel circuit structure can be as follows: Figure 12 The circuit is shown.

[0139] Because the main LED 300 and the repair LED 300' share the cathode pad 430, the main LED 300 and the repair LED 300' can be connected to the same reference voltage V. SS .

[0140] Additionally, although a separate repair anode pad 430 is provided for connection to the repair LED 300', both the repair anode pad 430 and the anode pad 410 can receive drive current from the same drive transistor 200, such as... Figure 12 As shown in the image.

[0141] The defective main LED 300 can be removed, or the wire connected to the defective main LED 300 can be cut without removing it.

[0142] The structure of a single sub-pixel of the display device 1 according to the embodiment has been described above. Hereinafter, the structure of a single pixel composed of a red sub-pixel, a green sub-pixel, and a blue sub-pixel will be described.

[0143] Figures 13 to 17 It is a plan view showing the single pixel structure consisting of red sub-pixels, green sub-pixels and blue sub-pixels according to various embodiments when viewed from above.

[0144] refer to Figure 13 Multiple LEDs 300R, 300G, and 300B forming a single pixel P can be arranged along a first direction corresponding to the width W of LED 300. The multiple LEDs may include a red LED 300R, a green LED 300G, and a blue LED 300B.

[0145] Multiple anode pads 410R, 410G, and 410B electrically connected to the anodes 310R, 310G, and 310B of multiple LEDs can also be arranged along the first direction of LED 300.

[0146] For example, such as Figure 13 As shown, multiple LEDs 300R, 300G, and 300B share the same cathode pad 420. Multiple repair anode pads 430R, 430G, and 430B may be disposed on opposite sides of the cathode pad 420, and the multiple repair anode pads 430R, 430G, and 430B may be arranged along a first direction in the same manner as the multiple anode pads 410R, 410G, and 410B. In this respect, the cathode pad 420 may be located between the multiple anode pads 410R, 410G, and 410B and the multiple repair anode pads 430R, 430G, and 430B.

[0147] That is, according to Figure 13For example, multiple LEDs 300R, 300G, and 300B can be arranged along a first direction, and anode pads 410 and repair anode pads 430 for a single LED can be arranged along a second direction corresponding to the length L of the LED. Therefore, the repair LED 300' and the main LED 300 can be aligned along the second direction. For example, red anode pads 410R and red repair anode pads 430R are arranged along the second direction. Furthermore, green anode pads 410G and green repair anode pads 430G are arranged along the second direction, while blue anode pads 410B and blue repair anode pads 430B are arranged along the second direction.

[0148] Typically, the shape of a single pixel is implemented as an approximate square. Therefore, by arranging the components within a single pixel to have similar lengths in both the first and second directions, a smaller pixel size can be achieved.

[0149] Therefore, in the display device 1 according to the embodiment, the pads for repairing LED 300' are arranged along the second direction (length direction), and the plurality of LEDs 300R, 300G and 300B are arranged along the first direction. Thus, the arrangement of the components contained in a single pixel can be made as square as possible, and the size of a single pixel is minimized.

[0150] As described above, after transferring multiple LEDs 300R, 300G, and 300B to the backplane 100, testing can be performed to identify whether any of the LEDs is defective. For example, when only the blue LED 300B among the multiple LEDs is defective, the red repair LED 300R' and green repair LED 300G' can be omitted, and only the blue repair LED 300B' can be installed, as shown. Figure 14 As shown in the image.

[0151] According to an embodiment, multiple LEDs 300R, 300G, and 300B may not be connected to a common cathode pad 420, but may be connected to individual cathode pads 420R, 420G, and 420B respectively, as shown below. Figure 15 As shown in the image.

[0152] According to an embodiment, the green LED 300G and blue LED 300B can be connected to a common cathode pad 420GB (first cathode pad), while the red LED 300R can be connected to a separate cathode pad 420R (second cathode pad), as shown. Figure 16 As shown in the image.

[0153] Even when not sharing the cathode pad 420, multiple LEDs 300R, 300G, and 300B can be connected to a common reference voltage V. SSAlternatively, when not sharing the cathode pad 420, multiple LEDs 300R, 300G, and 300B can be connected to a separate reference voltage V. SS .

[0154] The operating voltage of an LED can be determined by the color it emits. Generally, red LEDs have the lowest operating voltage, yellow and green LEDs have slightly higher operating voltages than red LEDs, and blue LEDs have the highest operating voltage.

[0155] Therefore, when the individual reference voltage V SS When connected to the red LED 300R, as Figure 15 and Figure 16 As shown, this can be achieved by increasing the reference voltage V connected to the other LEDs 300G and 300B. SS High reference voltage V SS Connect to the red LED 300R to reduce power consumption.

[0156] Alternative locations, such as Figure 17 As shown in the example, the red LED 300R and the green LED 300G can share cathode pad 420RG (the second cathode pad), and the blue LED 300B can be connected to a separate cathode 420B (the first cathode pad). In this case, the blue LED 300B can be connected to a separate reference voltage V. SS Alternatively, it can be connected to a common reference voltage V with the red LED 300R and the green LED 300G. SS .

[0157] When the blue LED 300B is connected to a separate reference voltage V SS At that time, the reference voltage V connected to the blue LED 300B can be used. SS Low reference voltage V SS Connect to the red LED 300R and green LED 300G to reduce power consumption.

[0158] Figure 18 This is a side cross-sectional view showing the cathode pad connected to the main LED 300 in the display device, separated from the cathode pad used for repairing the LED 300', according to an embodiment. Figure 19 It shows what it looks like when viewed from above. Figure 18 A plan view of the structure.

[0159] refer to Figure 18For example, the cathode pad 420 connected to the main LED 300 can be separated from the repair cathode pad 440 provided for the repair LED 300'. Even in this case, a single pixel structure can be provided as follows: a red LED 300R, a green LED 300G, and a blue LED 300B are arranged in a first direction, and anode pads 410R, 410G, and 410B and cathode pads 420R, 420G, and 420B are all connected to opposite ends of the LEDs in a second direction, and repair anode pads 430R, 430G, and 430B are arranged on the opposite side of the anode pads 410R, 410G, and 410B with respect to the cathode pads 420R, 420G, and 420B.

[0160] like Figure 19 As shown, the repair cathode pads 440R, 440G, and 440B can be positioned between the repair anode pads 430R, 430G, and 430B and the cathode pads 420R, 420G, and 420B. However, the embodiments are not limited to this, and the positions of the repair cathode pads 440R, 440G, and 440B can be interchanged with the positions of the repair anode pads 430R, 430G, and 430B.

[0161] Figure 20 This is a side cross-sectional view showing the main LED 300 in a display device according to an embodiment sharing an anode pad for repairing LED 300'. Figure 21 It shows Figure 20 The circuit diagram of the sub-pixel structure, and Figure 22 and Figure 23 It shows what it looks like when viewed from above. Figure 20 A view of the structure.

[0162] As described above, the main LED 300 and the repair LED 300' can share the cathode pad 420. However, the embodiments are not limited to this. Figure 20 As shown, the repair LED 300' can share the anode pad 410 with the main LED 300. In this case, a separate repair cathode pad 440 can be provided for connection to the repair LED 300'. When the repair LED 300' is installed due to the presence of a defective main LED 300, the anode 310' of the repair LED 300' can be connected to the anode pad 410, while the cathode 320' of the repair LED 300' can be connected to the repair cathode pad 440.

[0163] exist Figure 21The circuit diagram corresponding to this embodiment is shown. Although the cathode 320 of the main LED 300 and the cathode 320' of the repair LED 300' are connected to separate cathode pads 420 and 440, respectively, the cathode pads 420 and 440 can be connected to a common reference voltage V. SS This allows the main LED 300 and the repair LED 300' to be grounded together.

[0164] Figure 22 The overall structure of a single pixel P as viewed from above is shown, where the main LED 300 and the repair LED 300' share an anode pad 410. In the same manner as described above, where the main LED 300 and the repair LED 300' share a cathode pad 420, multiple main LEDs 300R, 300G, and 300B can be arranged along a first direction. Anodes 310R, 310G, and 310B, located at one end of the LED in a second direction, can be connected to anode pads 410R, 410G, and 410B, respectively, and cathodes 320R, 320G, and 320B, located at the other end of the LED, can be connected to cathode pads 420R, 420G, and 420B, respectively.

[0165] Repair cathode pads 440R, 440G, and 440B provided for the cathodes of repaired LEDs 300R', 300G', and 300B' can be arranged on the opposite sides of cathode pads 420R, 420G, and 420B with respect to anode pads 410R, 410G, and 410B, and arranged along a first direction of the main LED 300. Multiple anode pads 410R, 410G, and 410B can be disposed between multiple cathode pads 420R, 420G, and 420B and multiple repair cathode pads 440R, 440G, and 440B.

[0166] For example, when a defect occurs in the green LED 300G, the anode 310' of the green repair LED 300G' can be electrically connected to the anode pad 410G, and the cathode 320' of the green repair LED 300G' can be electrically connected to the repair cathode pad 440G, thereby mounting the green repair LED 300G' on the backplane 100. The defective main green LED 300G can be removed, or the wiring can be cut without removing the defective main green LED 300G.

[0167] like Figure 22 As shown, when the red LED 300R, green LED 300G, and blue LED 300B are connected to separate cathode pads 420R, 420G, and 420B respectively, power consumption can also be reduced by connecting the high reference voltage only to the red LED 300R or the low reference voltage only to the blue LED 300B, as described above.

[0168] Alternatively, the green LED 300G and blue LED 300B can be connected to a common cathode pad, or the red LED 300R and green LED 300G can be connected to a common cathode pad.

[0169] like Figure 23 As shown, the red LED 300R, green LED 300G, and blue LED 300B can be connected together to a single cathode pad 420. Alternatively, a common cathode pad 440 can be provided for the red repair LED 300R', green repair LED 300G', and blue repair LED 300B'.

[0170] Figures 20 to 23 The reference voltage V is shown. SS Directly connected to LED 300 and supplied with power supply voltage V by using PMOS type as driving transistor 200. DD The embodiments are described herein. However, the embodiments are not limited thereto. In the following, the case in which an NMOS type is used as the driving transistor 200 will be described.

[0171] Figure 24 This is a circuit diagram illustrating a sub-pixel circuit in a display device according to an embodiment, in which an NMOS transistor is used as a driving transistor and the power supply voltage V DD It is applied directly to the LED, and Figure 25 When the application Figure 24 A side cross-sectional view of the circuit structure.

[0172] In the PMOS transistor used as the driving transistor 200 in the above example, current flows from the source to the drain. On the other hand, in the NMOS transistor, current flows from the drain to the source. Therefore, when an NMOS transistor is used as the driving transistor 200 in the sub-pixel circuit, the cathode 320 of the LED 300 can be connected to the drain 230 of the driving transistor 200, and the reference voltage V... SS It can be connected to the source 240 of the driving transistor 200, such as Figure 24 and Figure 25 As shown in the figure. The power supply voltage V can be... DD It is directly applied to the anode 310 of LED 300. For this purpose, a power supply voltage V can be applied. DD The power line VL is connected to the anode pad 410, which is connected to the anode 310 of LED 300.

[0173] Power consumption can be reduced by applying a power supply voltage lower than that applied to the green LED 300G or blue LED 300B to the red LED 300R, because the power supply voltage is applied directly to the anode 310 of the LED 300.

[0174] When a repair LED 300' is installed due to the presence of a defective main LED 300, the anode 310' of the repair LED 300' can be electrically connected to the anode pad 410 connected to the anode 310 of the main LED 300, and the cathode 320' of the repair LED 300' can be electrically connected to a separate repair cathode pad 440, as referenced above. Figures 20 to 23 As described above. Although the repair cathode pad 440 and cathode pad 420 are physically separated, the two cathode pads 440 and 420 can be electrically connected to the same drain 230 of the driving transistor 200 via wiring. The positional relationship between the anode pad 410, cathode pad 420, repair cathode pad 440 and LED 300 is as described above. Figure 22 and Figure 23 As stated above.

[0175] Hereinafter, a method for manufacturing the display device according to an embodiment will be described. For example, the above-mentioned reference device can be manufactured by the manufacturing method discussed below. Figures 1 to 25 The display device under discussion. Therefore, embodiments of the manufacturing method of the display device will be described with reference to the above-described drawings.

[0176] Figure 26 This is a flowchart illustrating a method for manufacturing a backplate in a method for manufacturing a display device according to an embodiment.

[0177] refer to Figure 26 A plurality of driving transistors 200 configured to drive each of a plurality of sub-pixels are formed along one direction on the upper side of the substrate 101 (S310).

[0178] Refer again Figure 3 and Figure 4 The sub-pixel driving circuit includes a driving transistor 200 configured to drive the LED 300. Additionally, it applies a data voltage VDATA and a power supply voltage V to the LED 300, the switching transistor 200', and the capacitor 201. DD Reference voltage V SS Various wiring configurations can be included in the sub-pixel driving circuit. However, in this embodiment, only the driving transistor 200 will be described.

[0179] Forming a plurality of driving transistors 200 on the upper side of the substrate 101 may include: forming a buffer layer 103 on the substrate 101, providing an active layer 210 on the buffer layer 103, forming a gate insulating layer 111 on the buffer layer 103 where the active layer 210 is provided, and providing a gate 220 on the gate insulating layer 111. Furthermore, forming a plurality of driving transistors 200 on the upper side of the substrate 101 may include: forming an interlayer insulating layer 112 on the gate insulating layer 111 where the gate 220 is provided, and forming vias on the interlayer insulating layer 112 and the gate insulating layer 111. Additionally, forming a plurality of driving transistors 200 on the upper side of the substrate 101 may include: providing a source 240 and a drain 230 on the interlayer insulating layer 112, and electrically connecting the source 240 and the drain 230 to the active layer 210 through vias formed on the interlayer insulating layer 112 and the gate insulating layer 111. Furthermore, forming a plurality of driving transistors 200 on the upper side of the substrate 101 may include forming a planarization layer 113 on an interlayer insulating layer 112 on which a source electrode 240 and a drain electrode 230 are disposed.

[0180] Multiple anode pads 410R, 410G, and 410B, at least one cathode pad 420, and multiple repair anode pads 430R, 430G, and 430B are disposed on the planarization layer 113. This will be described in detail below.

[0181] In operation S311, multiple anode pads can be arranged along one direction, and in operation S312, at least one cathode pad can be arranged along one direction, facing the multiple anode pads. Additionally, in operation S313, multiple repair anode pads can be positioned along one direction, located on opposite sides of the multiple anode pads with respect to at least one cathode pad. "One direction" can correspond to the width direction of the LED 300, and the width direction can be perpendicular to the length direction of the LED 300. (See reference) Figure 1 The width direction of LED 300 can correspond to either the X direction or the Z direction.

[0182] The order in which multiple anode pads, at least one cathode pad, and multiple repair anode pads are set is not limited to the order in the flowchart. Therefore, multiple anode pads, at least one cathode pad, and multiple repair anode pads can be set simultaneously or in an order different from that in the flowchart.

[0183] In operation S314, an upper insulating layer is formed on the planarization layer, on which a plurality of anode pads, at least one cathode pad, and a plurality of repair anode pads are disposed.

[0184] In operation S315, connection holes configured to expose the multiple anode pads, at least one cathode pad, and multiple repair anode pads are formed on the upper insulating layer on the multiple anode pads, at least one cathode pad, and multiple repair anode pads.

[0185] The above process can be used to manufacture, for example Figure 4 The backplate 100 is shown. However, the embodiments are not limited to this; in addition to the process of manufacturing the backplate 100 described above, other processes may be added, and besides... Figure 4 In addition to the structure shown, the back panel 100 may also include other layers or other components.

[0186] In addition, such as Figure 13 As shown, a common cathode pad 420 can be provided for multiple LEDs 300R, 300G, and 300B, and as... Figure 15 As shown, individual cathode pads 420R, 420G, and 420B can be provided to multiple LEDs 300R, 300G, and 300B respectively. Figure 16 and Figure 17 As shown, common cathode pads 420GB and 420RG can be provided for some LEDs, and separate cathode pads 420R and 420B can be provided for other LEDs.

[0187] Figure 27 This is a flowchart illustrating a method for transferring an LED to a backplane and testing the LED in a method for manufacturing a display device according to an embodiment.

[0188] refer to Figure 27 In operation S320, multiple LEDs are transferred according to... Figure 26 The backplane 100 is manufactured using the process described above. For example, multiple LEDs 300R, 300G, and 300B can be picked up from the wafer and transferred to the backplane 100. In this respect, multiple LEDs 300R, 300G, and 300B can be simultaneously mounted on the backplane 100. Transferring or mounting the LED 300 to the backplane 100 may include electrically connecting an anode 310 disposed at one end of the LED 300 to an anode pad 410, and electrically connecting a cathode 320 disposed at the other end of the LED 300 to a cathode pad 420. The anode 310 and cathode 320 may be arranged along a second direction (length direction) of the LED 300.

[0189] As mentioned above, such as Figure 5The ACF 120 shown can be used to connect the LED 300 to the backplane 100. In this case, the ACF 120 is formed on the upper insulating layer 114 of the backplane 100. Heating the ACF 120 positions the anode 310 of the LED 300 towards the anode pad 410 exposed through the connection hole 114H, and presses the LED 300 onto the ACF 120, while simultaneously positioning the cathode 320 of the LED 300 towards the cathode pad 420 exposed through the connection hole 114H.

[0190] Since the ACF 120, which heats and applies pressure to it, allows current to flow in the direction of the applied pressure, the anode 310 and cathode 320 of the LED 300 can be electrically connected to the anode pad 410 and cathode pad 420 of the backplate, respectively.

[0191] However, the embodiments are not limited thereto, and according to another embodiment, the manufacturing method of the display device does not require the use of anisotropic conductive films. Therefore, the LED 300 can be electrically connected to the backplane 100 by other bonding methods (e.g., soldering methods using metallic ink). In particular, when using other bonding methods, a bank and passivation layer can be formed around the LED 300 to fill the air gaps formed around the anode pads 410 and cathode pads 420. For example, the passivation layer can be formed from materials such as acrylic acid, polymethyl methacrylate (PMMA), benzocyclobutene (BCB), polyimide, acrylate, epoxy resin, and polyester.

[0192] The barrier is formed of a light-absorbing material, a light-reflecting material, or a light-scattering material. Therefore, the barrier can absorb or block light incident from the outside, thereby improving the contrast of the bright room of the display device 1. For example, the barrier can be formed of an organic insulating material, an inorganic insulating material, or an opaque material such as a black matrix material. Alternatively, the barrier can be a distributed Bragg reflector (DBR) with high reflectivity, or a specular reflector formed of metal.

[0193] When the manufacturing method of the display device includes bonding the LED 300 and the backplate 100 using an ACF 120, the LED 300 is pressed into and embedded in the ACF 120. Therefore, no air gap is formed around the anode pad 410 and the cathode pad 420, thus eliminating the need for structures such as spacers and passivation layers. However, by including spacers formed of light-absorbing, light-reflecting, or light-scattering materials, the bright-cell contrast of the display device 1 can also be improved. Therefore, according to an embodiment, the display device may include the ACF 120 and spacers formed of light-absorbing, light-reflecting, or light-scattering materials.

[0194] After transferring multiple LEDs to the backplane, in operation S321, a test can be performed to identify whether any one of the LEDs is defective. Various methods can be used to perform the test. For example, a method can be used to photograph multiple LEDs to identify whether they are emitting light normally.

[0195] In operation S322, it is determined whether a defective LED is found based on the test results. When a defective LED is found (yes in S322), in operation S323, a repair LED 300' corresponding to the defective LED is mounted on the backplate 100. Specifically, the anode 310' of the repair LED 300' can be connected to the repair anode pad 430, and the cathode 320' of the repair LED 300' can be connected to the cathode pad 420. When using ACF 120 to bond the LED 300 and the backplate 100, a portion of the ACF 120 at the position corresponding to the repair anode pad 430 and the cathode pad 420 can be cut off, for example, holes can be formed in the ACF 120 to expose the repair anode pad 430 and the cathode pad 420. The repair LED 300' can be connected to the backplate 100 again by using a soldering method utilizing metallic ink or ACF 120.

[0196] In operation S324, the wiring connected to the defective LED can be disconnected. Because the repair LED 300' is connected to the cathode pad 420, the wiring connected to the anode pad 410 can be disconnected (e.g., the wiring can be cut), or the electrical connection between the anode pad 410 and the LED 300 can be disconnected (e.g., the wiring can be cut). Alternatively, the defective LED 300 can be removed.

[0197] Figure 28 This is a flowchart illustrating a method for manufacturing a backplate in a method for manufacturing a display device according to an embodiment.

[0198] refer to Figure 28 A plurality of driving transistors 200, configured to drive each of a plurality of sub-pixels, are formed along one direction on the upper side of the substrate 101. The process of forming the plurality of driving transistors is described above (refer to the above description). Figure 26 As stated above.

[0199] In operation S331, multiple anode pads can be arranged along one direction, and in operation S332, at least one cathode pad can be arranged along one direction facing the multiple anode pads. In operation S333, at least one repair cathode pad can be positioned along one direction on the opposite side of the at least one cathode pad with respect to the multiple anode pads. "One direction" can correspond to the width direction of the LED 300, and the width direction can be perpendicular to the length direction of the LED 300. (See reference) Figure 1The width direction of LED 300 can correspond to either the X direction or the Z direction.

[0200] The order in which multiple anode pads, at least one cathode pad, and at least one repair cathode pad are arranged is not limited to the order in the flowchart, so multiple anode pads, at least one cathode pad, and at least one repair cathode pad can be arranged simultaneously or in an order different from that in the flowchart.

[0201] In operation S334, an upper insulating layer is formed on the planarization layer, on which a plurality of anode pads, at least one cathode pad, and at least one repair cathode pad are disposed.

[0202] In operation S335, a connection hole configured to expose the plurality of anode pads, at least one cathode pad, and at least one repair cathode pad is formed on the upper insulating layer on the plurality of anode pads, at least one cathode pad, and at least one repair cathode pad.

[0203] It can be manufactured according to the above process, such as Figure 22 The backplate 100 is shown. However, the embodiments are not limited to this; in addition to the process of manufacturing the backplate 100 described above, other processes may be added, and besides... Figure 22 In addition to the structure shown, the back panel 100 may also include other layers or other components.

[0204] Repair cathode pads 440R, 440G, and 440B, configured to connect to the cathodes of repair LEDs 300R', 300G', and 300B', can be arranged on the opposite sides of cathode pads 420R, 420G, and 420B with respect to anode pads 410R, 410G, and 410B, and the repair cathode pads 440R, 440G, and 440B can be further arranged along a first direction of the main LED 300. Multiple anode pads 410R, 410G, and 410B are disposed between multiple cathode pads 420R, 420G, and 420B and multiple repair cathode pads 440R, 440G, and 440B.

[0205] Additionally, the green LED 300G and blue LED 300B can be connected to a common cathode pad, or the red LED 300R and green LED 300G can be connected to a common cathode pad.

[0206] Alternative locations, such as Figure 23 As shown, the red LED 300R, green LED 300G, and blue LED 300B can be connected together to a single cathode pad 420. Additionally, a common cathode pad 440 can be provided for the repair LED 300'.

[0207] according to Figure 26In the above embodiment, the driving transistor 200 formed on the upper side of the substrate 101 is a PMOS type transistor, wherein current flows from the source 240 to the drain 230. According to Figure 28 In this embodiment, the driving transistor 200 formed on the upper side of the substrate 101 can be a PMOS transistor or an NMOS transistor. In the NMOS transistor, current flows from the drain 230 to the source 240. When the driving transistor 200 is implemented as an NMOS transistor, such as Figure 24 As shown, the power supply voltage V can be... DD It is applied directly to the LED. For this purpose, a power supply voltage V can be applied. DD The power line VL is connected to the anode pad 410, which is connected to the anode 310 of the LED 300.

[0208] Furthermore, the cathode pad 420 can be connected to the drain 230 of the driving transistor 200, and the reference voltage V SS It can be connected to the source 240 of the driving transistor 200.

[0209] Figure 29 This is a flowchart illustrating another method for transferring an LED to a backplane and testing the LED in a method for manufacturing a display device according to an embodiment.

[0210] refer to Figure 29 In operation S340, multiple LEDs are transferred according to... Figure 28 The backplane 100 is manufactured using the above process. Transferring the LED 300 to the backplane 100 may include electrically connecting the anode 310 at one end of the LED 300 to the anode pad 410, and electrically connecting the cathode 320 at the other end of the LED 300 to the cathode pad 420. When the driving transistor 200 of the backplane 100 is a PMOS transistor, the drain 230 of the driving transistor 200 is electrically connected to the anode pad 410, and the reference voltage V... SS Connected to cathode pad 420. When the driving transistor 200 of the backplane 100 is an NMOS transistor, the power supply voltage V... DD It is applied to the anode pad 410, and the drain 230 is connected to the cathode pad 420.

[0211] After transferring multiple LEDs to the backplane, in operation S341, a test configured to identify whether the LEDs are defective can be performed.

[0212] In operation S342, it is determined whether a defective LED is found based on the test results. When a defective LED is found (yes in S342), in operation S343, a repair LED 300' corresponding to the defective LED is mounted on the backplate 100. Specifically, the anode 310' of the repair LED 300' can be connected to the anode pad 410, and the cathode 320' of the repair LED 300' can be connected to the repair cathode pad 440. When using ACF 120 to bond the LED 300 and the backplate 100, a portion of the ACF 120 at the position corresponding to the repair cathode pad 440 and the anode pad 410 can be cut off, for example, holes can be formed in the ACF 120 to expose the repair cathode pad 440 and the anode pad 410. The repair LED 300' can be connected to the backplate 100 again by using a soldering method utilizing metallic ink or ACF 120.

[0213] In operation S344, the wiring connected to the defective LED can be disconnected, for example, by cutting the wiring. Alternatively, the defective LED 300 can be removed.

[0214] The above embodiments have been described based on a single pixel comprising multiple LEDs. Multiple single pixels can be formed in an M×N array to form a unit module 10, and multiple unit modules 10 can be mounted on a housing 21 to manufacture a large-area display device 1. Alternatively, a display device 1 can be manufactured in which single pixels are formed in an M×N array instead of module units.

[0215] Furthermore, after mounting the LED 300 or LED 300 and repair LED 300' on the backplate 100, a transparent layer configured to protect the LED 300 or LED 300 and repair LED 300' can be formed.

[0216] Because the LEDs forming a single pixel are arranged along the first direction (width direction) of the LED, and the repair anode pads or repair cathode pads for a single LED are arranged relative to the anode pads along the second direction (length direction), the arrangement of the components included in a single pixel can be optimized, thus minimizing the size of a single pixel and achieving high resolution.

[0217] It is evident from the above description that the display device and its manufacturing method can reduce the pixel size and achieve high resolution by optimizing the arrangement between the LEDs that form the pixels and the electrode pads electrically connected to the LEDs.

[0218] Furthermore, display modules can be installed as a single unit and applied to electronic products or devices that require a display, such as wearable devices, portable devices, and handheld devices. Additionally, multiple display modules can be assembled in a matrix and then applied to display devices such as personal computer monitors, high-definition televisions, and digital signage.

[0219] While some embodiments have been shown and described, those skilled in the art will understand that changes can be made to these embodiments without departing from the principles and spirit of this disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A display device, comprising: a back plate; and a plurality of light emitting diodes (LEDs) disposed on the back plate to form pixels and spaced apart from each other along a width direction of one of the plurality of LEDs, wherein the back plate is formed to include: a substrate; a plurality of anode pads disposed on the substrate and spaced apart from each other along the width direction; a plurality of cathode pads disposed on the substrate, spaced apart from each other along the width direction, and spaced apart from the plurality of anode pads along a length direction crossing the width direction; and a plurality of repair anode pads disposed on the substrate, spaced apart from each other along the width direction, and spaced apart from the plurality of anode pads and the plurality of cathode pads along the length direction, wherein the plurality of LEDs are mounted to the formed back plate after the back plate is formed, wherein each of the plurality of LEDs includes an anode electrically connected to a corresponding anode pad of the plurality of anode pads and a cathode electrically connected to a corresponding cathode pad of the plurality of cathode pads, wherein the anode is formed at one end of one of the plurality of LEDs and the cathode is formed at the other end of the LED along the length direction, wherein the plurality of cathode pads are interposed between the plurality of anode pads and the plurality of repair anode pads, wherein the plurality of LEDs include red LEDs, green LEDs, and blue LEDs, and wherein the plurality of cathode pads include: a first cathode pad electrically connected to cathodes of the green LEDs and the blue LEDs; and a second cathode pad electrically connected to a cathode of the red LEDs. 2.The display device of claim 1, wherein the first cathode pad is a shared cathode pad commonly connected to cathodes of the green LEDs and the blue LEDs of the plurality of LEDs. 3.The display device of claim 1, wherein a first reference voltage is provided to the first cathode pad, and a second reference voltage higher than the first reference voltage is provided to the second cathode pad. 4.The display device of claim 1, wherein the back plate further includes: an upper insulating layer disposed on the plurality of anode pads and the plurality of repair anode pads, wherein connection holes are formed through the upper insulating layer to expose the plurality of anode pads and the plurality of repair anode pads. 5.The display device of claim 4, wherein an anode of each of the plurality of LEDs is electrically connected to a corresponding anode pad exposed through the connection holes. 6.The display device of claim 4, further comprising: a repair LED corresponding to a defective LED, wherein a repair anode pad of the plurality of repair anode pads corresponding to the defective LED is electrically connected to the repair LED and exposed through the connection holes. 7.The display device of claim 1, wherein each of the plurality of LEDs is configured to emit light backward to the back plate. 8.A display device, comprising: a back plate; and a plurality of light emitting diodes (LEDs) disposed on the back plate to form pixels and spaced apart from each other along a width direction of one of the plurality of LEDs, wherein the back plate is formed to include: a substrate; a plurality of anode pads disposed on the substrate and spaced apart from each other along the width direction; a plurality of cathode pads disposed on the substrate, spaced apart from each other along the width direction, and spaced apart from the plurality of anode pads along a length direction crossing the width direction; and a plurality of repair anode pads disposed on the substrate, spaced apart from each other along the width direction, and spaced apart from the plurality of anode pads and the plurality of cathode pads along the length direction, wherein the plurality of LEDs are mounted to the formed back plate after the back plate is formed, wherein each of the plurality of LEDs includes an anode electrically connected to a corresponding anode pad of the plurality of anode pads and a cathode electrically connected to a corresponding cathode pad of the plurality of cathode pads, wherein the anode is formed at one end of one of the plurality of LEDs and the cathode is formed at the other end of the LED along the length direction, wherein the plurality of cathode pads are interposed between the plurality of anode pads and the plurality of repair anode pads, wherein the plurality of LEDs include red LEDs, green LEDs, and blue LEDs, and wherein the plurality of cathode pads include: a first cathode pad electrically connected to cathodes of the green LEDs and the blue LEDs; and a second cathode pad electrically connected to a cathode of the red LEDs. a plurality of light emitting diodes (LEDs) disposed on the backplane to form a pixel and spaced apart from each other along a width direction of one of the plurality of LEDs, wherein the backplane is formed to include: a substrate; a plurality of anode pads disposed on the substrate and spaced apart from each other along the width direction; a plurality of cathode pads disposed on the substrate, spaced apart from each other along the width direction, and spaced apart from the plurality of anode pads along a length direction crossing the width direction; and at least one repair cathode pad disposed on the substrate and spaced apart from the plurality of anode pads and the plurality of cathode pads along the length direction, wherein the plurality of LEDs are mounted to the formed backplane after the backplane is formed, wherein each of the plurality of LEDs includes an anode electrically connected to a corresponding anode pad of the plurality of anode pads and a cathode electrically connected to a corresponding cathode pad of the plurality of cathode pads, wherein, in the length direction, the anode is formed at one end of one of the plurality of LEDs and the cathode is formed at the other end of the LED of the plurality of LEDs, wherein the plurality of anode pads are interposed between the plurality of cathode pads and the at least one repair cathode pad, wherein the plurality of LEDs include a red LED, a green LED, and a blue LED, and wherein the plurality of cathode pads include: a first cathode pad electrically connected to cathodes of the green LED and the blue LED; and a second cathode pad electrically connected to a cathode of the red LED.

9. The display apparatus of claim 8, wherein the backplane further includes: a plurality of driving transistors disposed on an upper side of the substrate and respectively corresponding to the plurality of LEDs, wherein each of the plurality of anode pads is electrically connected to a drain of a corresponding driving transistor of the plurality of driving transistors, and wherein the plurality of cathode pads are connected to a reference voltage.

10. The display apparatus of claim 8, wherein the backplane further includes: an upper insulating layer disposed on the plurality of anode pads, the plurality of cathode pads, and the at least one repair cathode pad, wherein connection holes are formed through the upper insulating layer to expose the plurality of anode pads, the plurality of cathode pads, and the at least one repair cathode pad.

11. The display apparatus of claim 10, wherein an anode of each of the plurality of LEDs is electrically connected to a corresponding anode pad exposed through the connection holes, and wherein a cathode of each of the plurality of LEDs is electrically connected to a corresponding cathode pad of the plurality of cathode pads exposed through the connection holes.

12. A manufacturing method of a display apparatus in which a plurality of light emitting diodes (LEDs) form a pixel, the manufacturing method comprising: forming a backplane including: disposing a plurality of anode pads on a substrate, the plurality of anode pads being spaced apart from each other along a width direction of one of a plurality of LEDs; a plurality of cathode pads are provided on the substrate, the plurality of cathode pads are spaced apart from each other along the width direction and are spaced apart from the plurality of anode pads along a length direction intersecting the width direction; a plurality of repair anode pads are provided on the substrate, the plurality of repair anode pads are spaced apart from each other along the width direction and are spaced apart from the plurality of anode pads and the plurality of cathode pads along the length direction; an upper insulating layer is formed on the plurality of anode pads, the plurality of cathode pads, and the plurality of repair anode pads; and connection holes are formed through the upper insulating layer to expose the plurality of anode pads, the plurality of cathode pads, and the plurality of repair anode pads; and the plurality of LEDs are mounted to the formed backplane, the plurality of LEDs are spaced apart from each other along the width direction, each of the plurality of LEDs includes an anode and a cathode, wherein in the length direction, the anode is formed at one end of one of the plurality of LEDs and the cathode is formed at the other end of the LED of the plurality of LEDs, wherein the plurality of cathode pads are interposed between the plurality of anode pads and the plurality of repair anode pads, wherein the plurality of LEDs include a red LED, a green LED, and a blue LED, and wherein the providing the plurality of cathode pads on the substrate includes: providing a first cathode pad electrically connected to cathodes of the green LED and the blue LED; and providing a second cathode pad electrically connected to a cathode of the red LED.

13. The manufacturing method of claim 12, wherein, the mounting the plurality of LEDs to the formed backplane includes: electrically connecting the anode of each of the plurality of LEDs to a corresponding anode pad of the plurality of anode pads exposed through the connection holes; and electrically connecting the cathode of each of the plurality of LEDs to a corresponding cathode pad of the plurality of cathode pads exposed through the connection holes.

14. The manufacturing method of claim 13, wherein the electrically connecting the anode of each of the plurality of LEDs to the corresponding anode pad includes: forming an anisotropic conductive film on the upper insulating layer; compressing the anode of the LED of the plurality of LEDs at a position on the anisotropic conductive film corresponding to the corresponding anode pad; and heating the anisotropic conductive film. ​

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