KR20210082647A - Display device - Google Patents

Abstract

In a display device according to the exemplary embodiment of the present specification, the display device includes a vertical LED element arranged on a substrate and including a first electrode, an active layer, and a second electrode, a first connection electrode connected to the first electrode, a second connection electrode connected to the second electrode; a pixel circuit that provides a drive current to the vertical LED device, and an adhesive member in contact with the second electrode. In addition, the second connection electrode and the adhesive member overlap the vertical LED element between the substrate and the vertical LED element. Accordingly, the LED element can be stably attached to the substrate, and a high-resolution trademark display device can be realized.

Description

display device {DISPLAY DEVICE}

This specification relates to a display device, and more particularly, to a display device using a vertical light emitting diode (LED).

Liquid Crystal Display Device (LCD), Organic Light Emitting Display Device (OLED), and Quantum Dot Display Device (QD), which have been widely used up to now, have gradually expanded their application range. is expanding

In the above-described display devices, a plurality of light emitting devices are disposed on a substrate of the display device to implement an image, and a driving device that supplies a driving signal or a driving current to control each light emitting device to individually emit light is provided with the light emitting device. Arranged together on a substrate, a plurality of light emitting devices arranged on the substrate are interpreted according to the arrangement of information to be displayed and displayed on the substrate.

Since the liquid crystal display is not a self-emission method, a backlight unit disposed to emit light on the rear surface of the liquid crystal display is required. The backlight unit increases the thickness of the liquid crystal display device, has limitations in implementing the display device in various designs such as flexible or circular shapes, and may reduce luminance and response speed.

Meanwhile, a display device having a self-luminous element may be implemented to be thinner than a display device having a built-in light source, and thus a flexible and foldable display device may be realized. A display device having a self-light emitting device may include an organic light emitting display device including an organic material as a light emitting layer and an LED display device using an LED as a light emitting device. Since a separate light source is not required, it can be used as a thinner or various types of display devices.

However, in the organic light emitting display device using an organic material, since bad pixels such as oxidation between the organic light emitting layer and the electrode due to the penetration of moisture and oxygen are likely to occur, various technical configurations are additionally required to minimize the penetration of oxygen and moisture.

In order to solve the above problems, recently, research and development of a display device using an inorganic LED as a light emitting element is being conducted, and the light emitting display device has been in the spotlight as a next-generation display device because of its high image quality and high reliability. have.

An LED device is a semiconductor light emitting device that emits light when a current is passed through a semiconductor, and is widely used in various display devices such as lighting, TV, signage display, and tiling display. The LED device consists of an n-type electrode, a p-type electrode, and an active layer between them. The n-type electrode and the p-type electrode are each formed of a semiconductor. When a current flows through the n-type electrode and the p-type electrode, electrons from the n-type electrode and holes from the p-type electrode combine in the active layer to emit light.

The LED device is composed of a compound semiconductor such as GaN, which can inject high current due to the nature of the inorganic material, thus realizing high luminance, and having low environmental impact such as heat, moisture, and oxygen, and thus has high reliability.

In addition, since the LED device has an internal quantum efficiency of 90%, which is higher than that of an organic light emitting diode display, a high-brightness image can be displayed and a display device with low power consumption can be realized.

In addition, unlike the organic light emitting display device, since the inorganic material is used, there is no need for a separate encapsulation film or encapsulation substrate for minimizing the penetration of oxygen and moisture to a level where the effects of oxygen and moisture are insignificant. Accordingly, there is an advantage in that the non-display area of the display device, which is a margin area that may be generated by disposing the encapsulation film or the encapsulation substrate, can be minimized.

However, a light emitting device, such as an LED device, may be formed using a separate semiconductor substrate, and then may require a procedure to be implanted in a panel on which a driving circuit is formed. In order to provide an LED display device having the above-described advantages, a lot of time and errors may occur in the process of implanting a light emitting device into a panel, so technologies that can minimize this are required, and many research activities are being conducted on this. .

The LED device may be classified into a horizontal LED device in which an n-type electrode and a p-type electrode are formed on the same surface of the LED device, and a vertical LED device in which an n-type electrode and a p-type electrode face each other.

When a horizontal LED device is implanted on a substrate, the area is up to twice that of a vertical LED device having the same light emitting area, so the material cost of the LED device increases, and as a high-resolution display device is required, the process of transferring the LED device Adhesion failure increases.

Accordingly, the inventors of the present specification have recognized the above-mentioned problems, and have invented a display device including an LED device capable of reducing the area occupied by the LED device and capable of large area and mass production.

An object to be solved according to an embodiment of the present specification is to provide a display device in which an LED element can be stably attached to a substrate.

The tasks of the present specification are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

In the display device according to the exemplary embodiment of the present specification, the display device includes a vertical LED device arranged on a substrate and including a first electrode, an active layer, and a second electrode, a first connection electrode connected to the first electrode, and a second electrode A second connection electrode connected to the electrode, a pixel circuit providing a driving current to the vertical LED element, and an adhesive member contacting the second electrode. In addition, the second connecting electrode and the adhesive member overlap the vertical LED element between the substrate and the vertical LED element. Accordingly, the LED element can be stably attached to the substrate and a high-resolution trademark display device can be realized.

The details of other embodiments are included in the detailed description and drawings.

According to the embodiments of the present specification, by forming the second connection electrode and the adhesive member between the substrate and the LED device and forming the second connection electrode in the groove provided in the adhesive member, the adhesive force between the LED device and the substrate can be improved. have.

And, according to the embodiments of the present specification, by providing an adhesive member between the substrate and the LED device and providing a second connection electrode and a step difference compensation layer on the upper and lower portions of the adhesive member, the adhesive force between the LED device and the substrate is improved can do it

And, according to the embodiments of the present specification, by providing a step compensation structure on the LED device, and attaching the LED device having the step compensation structure on the adhesive member on which the second connection electrode is formed, the adhesive force between the LED device and the substrate is increased. can be improved

And, according to the embodiments of the present specification, by forming an insulating layer on the protective layer covering the pixel circuit, it is possible to provide a flat surface and fix the position of the vertical LED device.

Since the contents of the specification described in the problems to be solved above, the means for solving the problems, and the effects do not specify the essential characteristics of the claims, the scope of the claims is not limited by the matters described in the contents of the specification.

1 is a plan view illustrating a display device according to an exemplary embodiment of the present specification.
FIG. 2 is a circuit diagram illustrating a configuration of a unit pixel according to the exemplary embodiment shown in FIG. 1 .
3 is a plan view illustrating a sub-pixel in which an LED device is disposed according to an exemplary embodiment of the present specification.
4 and 5 are cross-sectional views of subpixels on which LED devices are disposed according to an exemplary embodiment of the present specification, respectively, cut in different directions.
6 and 7 are cross-sectional views of an LED device according to an embodiment of the present specification, respectively.
8A to 8E are diagrams illustrating a step of implanting an LED device according to an embodiment of the present specification of FIG. 4 to a panel.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in a singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' One or more other parts may be placed between two parts unless , 'directly' and 'adjacent' are used.

In the case of a description of a temporal relationship, for example, when a temporal relationship is described as 'after', 'following', 'after', 'before', etc., 'immediately' or 'directly' Unless ' is used, cases that are not continuous may be included.

Each feature of the various embodiments of the present specification may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other or may be implemented together in a related relationship. may be

Hereinafter, a display device and a method of manufacturing the display device according to an exemplary embodiment of the present specification will be described with reference to the accompanying drawings.

1 is a plan view illustrating a display device according to an exemplary embodiment of the present specification, and FIG. 2 is a circuit diagram illustrating a configuration of a unit pixel according to the exemplary embodiment shown in FIG. 1 .

1 and 2 , the display device 100 according to an exemplary embodiment of the present specification includes a substrate 110 divided into a display area DA having a plurality of unit pixels UP and a non-display area NDA. ) is included.

The unit pixel UP may include a plurality of sub-pixels SP1 , SP2 , and SP3 on the front surface 110a of the substrate 110 , and typically includes red, blue, and green colors. It may include, but is not limited to, the sub-pixels SP1 , SP2 , and SP3 emitting light of , and may include sub-pixels emitting white light or the like.

The substrate 110 is an array substrate on which transistors are formed, and includes a plastic material or a glass material.

The substrate 110 according to an example may include an opaque or colored polyimide material. In this case, a back plate coupled to the rear surface of the substrate 110 may be further included to maintain the substrate 110 in a planar state. The back plate according to an example may include a plastic material, for example, a polyethylene terephthalate material. The substrate 110 according to an example may be a glass substrate. For example, the glass substrate 110 may have a flexible characteristic as a thin glass substrate having a thickness of 100 μm or less.

Also, the substrate 110 may be divided into two or more substrates or two or more layers.

The non-display area NDA may be defined as an area on the substrate 110 excluding the display area DA, may have a relatively narrow width (or size) compared to the display area DA, and may be defined as a bezel area. can be

Each of the plurality of unit pixels UP is disposed in the display area DA. In this case, each of the plurality of unit pixels UP has a predetermined first reference pixel pitch along the X-axis direction and the display area DA has a preset second reference pixel pitch along the Y-axis direction. ) is placed in Each of the first reference pixel pitch and the second reference pixel pitch may be defined as a distance between the central portions of each adjacent unit pixel UP in the X-axis direction or the Y-axis direction.

The distance between the sub-pixels SP1, SP2, and SP3 constituting the unit pixel UP is also defined as the first reference sub-pixel pitch and the second reference sub-pixel pitch similarly to the first reference pixel pitch and the second reference pixel pitch. can be

In the display device 100 including the LED element 160 , the width of the non-display area NDA may be smaller than the pixel pitch or the sub-pixel pitch, and the non-display area (NDA) having a length equal to or smaller than the pixel pitch or the sub-pixel pitch. NDA), for example, when a tiling display device is implemented, a tiling display device having substantially no bezel area is implemented because the non-display area NDA is smaller than a pixel pitch or a subpixel pitch. can

In order to implement a tiling display device or a multi-screen display device in which the bezel area is substantially absent or minimized, the display device 100 includes a first reference pixel pitch, a second reference pixel pitch, and a first reference sub-pixel in the display area DA. Although the pixel pitch and the second reference subpixel pitch may be kept constant, the display area DA is defined as a plurality of areas and the above-described pitch lengths are different in each area, but the non-display area NDA By making the pixel pitch of the region adjacent to the ? and the pixel pitch wider than the other regions, the size of the bezel region can be made smaller than the pixel pitch. In this case, since the display device 100 having different pixel pitches may cause image distortion, image processing is performed by comparing and sampling with an adjacent area in consideration of the set pixel pitch to eliminate image distortion. while reducing the bezel area.

A configuration and a driving circuit of the sub-pixels SP1 , SP2 , and SP3 constituting the unit pixel UP of the display device 100 will be described with reference to FIG. 2 . The pixel driving lines are provided on the front surface 110a of the substrate 110 to supply signals necessary for each of the plurality of sub-pixels SP1 , SP2 , and SP3 . The pixel driving lines according to the exemplary embodiment of the present specification include a gate line GL, a data line DL, and a power line. The gate line GL includes a first gate line GL1 , a second gate line GL2 , and an emission line EL, and the power line includes a driving power line DPL, a common power line CPL, Includes an initialization power line (IL).

The gate lines GL are provided on the front surface 110a of the substrate 110 , and are spaced apart at regular intervals along the vertical axis direction Y while extending long along the horizontal axis direction X of the substrate 110 . .

The data line DL is provided on the front surface 110a of the substrate 110 to intersect the gate line GL, and extends along the vertical axis direction Y of the substrate 110 in the horizontal axis direction X. are spaced at regular intervals along the

The driving power line DPL is provided on the substrate 110 to be parallel to the data line DL, and may be formed together with the data line DL. In addition, each of the driving power lines DPL supplies the pixel driving power provided from the outside to the adjacent sub-pixels SP1 , SP2 , and SP3 . For example, one driving power line DPL may be provided for each of the plurality of unit pixels UP. In this case, at least three sub-pixels SP1 , SP2 , and SP3 constituting the unit pixel UP share one driving power line DPL. Accordingly, the number of driving power lines DPL for driving each of the sub-pixels SP1, SP2, and SP3 can be reduced, and the aperture ratio of each unit pixel UP by the reduced number of driving power lines DPL. may be increased or the size of each unit pixel UP may be decreased.

The common power line CPL is provided on the substrate 110 to be parallel to the gate line GL, and may be formed together with the gate line GL. In addition, the common power line CPL supplies the common power provided from the outside to the adjacent sub-pixels SP1 , SP2 , and SP3 .

Each of the subpixels SP1 , SP2 , and SP3 is provided in a subpixel area defined by the gate line GL and the data line DL. In addition, each of the sub-pixels SP1 , SP2 , and SP3 may be defined as an area of a minimum unit in which light is actually emitted.

At least three sub-pixels SP1 , SP2 , and SP3 adjacent to each other may constitute one unit pixel UP for color display. For example, one unit pixel UP includes a red sub-pixel SP1, a green sub-pixel SP2, and a blue sub-pixel SP3 adjacent to each other along the horizontal axis direction X, and improves luminance. It may further include a white sub-pixel for the purpose. Although the arrangement structure of the sub-pixels shown in this specification is a stripe shape, it is not limited thereto.

Each of the plurality of sub-pixels SP1 , SP2 , and SP3 according to the exemplary embodiment of the present specification includes a pixel circuit 120 and an LED element 160 .

The pixel circuit 120 is provided in a circuit region defined in each of the subpixels SP1 , SP2 , and SP3 and is connected to the adjacent gate line GL, the data line DL, and the power supply line. The pixel circuit 120 is configured according to a data signal provided through the data line DL in response to a scan pulse provided through the gate line GL based on the pixel driving power provided through the driving power line DPL. The current flowing through the LED element 160 is controlled. The pixel circuit 120 according to an embodiment of the present specification includes a T1 transistor T1, a T2 transistor T2, a T3 transistor T3, a T4 transistor T4, a T5 transistor T5, a driving transistor DT, and a capacitor Cst. The T3 transistor T3 , the T4 transistor T4 , and the driving transistor DT are implemented as a PMOS type thin film transistor having good response characteristics, and the T1 transistor T1 , the T2 transistor T2 , and the T5 transistor T5 are It can be implemented as an NMOS type thin film transistor having good off-current characteristics. However, the technical spirit of the present invention is not limited thereto. For example, at least one of the T1 transistors T1 to T5 transistors T5 and the driving transistor DT is implemented as an NMOS type thin film transistor having good off-current characteristics, and the remaining transistors are PMOS type transistors having good response characteristics. It may be implemented as a thin film transistor. Alternatively, the T1 transistors T1 to T5 transistors T5 and the driving transistor DT may all be implemented as PMOS type thin film transistors.

The LED element 160 is mounted on each of the sub-pixels SP1 , SP2 , and SP3 . The LED element 160 is electrically connected to the pixel circuit 120 of the corresponding sub-pixel and the common power line CPL, so that the current flowing from the pixel circuit 120, that is, the driving transistor DT, to the common power line CPL. lighted by The LED device 160 according to an embodiment of the present specification may be an optical device or a light emitting diode chip emitting any one of red light, green light, blue light, and white light. Here, the light emitting diode chip may have a scale of 1 to 100 micrometers, but is not limited thereto, and may have a size smaller than the size of the remaining light emitting areas except for the circuit area occupied by the pixel circuit 120 among the subpixel areas.

The driving transistor DT is a driving device that controls a current flowing through the LED device 160 according to the gate-source voltage of the driving transistor DT. The driving transistor DT includes a gate electrode connected to the first node N1 , a source electrode connected to the driving power line DPL, and a drain electrode connected to the second node N2 .

The T1 transistor T1 is connected between the first node N1 and the second node N2 and is switched according to the first gate signal. The gate electrode of the T1 transistor T1 is connected to the first gate line GL1 to which the first gate signal is applied. The T1 transistor T1 is diode-connected by connecting the source electrode and the drain electrode of the driving transistor DT during turn-on. In this case, the T1 transistor T1 senses and compensates the threshold voltage factor of the driving transistor DT.

The T2 transistor T2 is connected between the data line DL and the third node N3 and is switched according to the first gate signal. The gate electrode of the T2 transistor T2 is connected to the first gate line GL1 . The T2 transistor T2 is turned on to apply a data signal to the third node N3 .

The T3 transistor T3 is connected between the second node N2 and the LED element 160 and is switched according to an emission signal provided through the emission line EL. The T3 transistor T3 is turned on to provide a current flowing through the driving transistor DT to the LED device 160 . The T3 transistor T3 controls the LED device 160 having a low emission threshold voltage not to emit light due to the initialization voltage.

The T4 transistor T4 is connected between the third node N3 and the initialization power line IL, and is switched according to the emission signal. The T4 transistor T4 is turned on and provides the initialization power provided through the initialization power line IL to the third node N3 to initialize the voltage of the third node N3 .

The T5 transistor T5 is connected between the second node N2 and the initialization power line IL, and is switched according to a second gate signal provided through the second gate line GL2 . The T5 transistor T5 is turned on to provide initialization power to the second node N2 to initialize the voltage of the second node N2 .

The capacitor Cst is provided in the overlapping region of the first node N1 and the third node N3 to store a voltage corresponding to the data signal supplied to the gate electrode of the driving transistor DT, and use the stored voltage to the driving transistor ( DT) is turned on.

Next, driving of the pixel circuit 120 will be described. The driving of the pixel circuit 120 of FIG. 2 may be divided into a first initialization period, a second initialization period, a compensation period, a sustain period, and an emission period. In the first initialization period, since the emission signal and the second gate signal are in a gate-on voltage state, the voltage of the third node N3 is initialized and the LED device 160 maintains a light-emitting state. In the second initialization period, the emission signal is converted to the gate-off voltage, the first gate signal is converted to the gate-on voltage, and the second gate signal maintains the gate-on voltage, so that the LED device 160 stops light emission, A data signal is applied to the third node N3 . In the compensation section, the second gate signal is converted to a gate-off voltage, and the T1 transistor T1 is turned on, so that the driving transistor DT is diode-connected to perform a threshold voltage compensation process. In the sustain period, since the first gate signal, the second gate signal, and the emission signal are all gate-off voltage states, the voltage applied in the previous period is maintained at each node. During the light-emitting period, the LED element 160 emits light by the driving current provided from the driving transistor DT while the emission signal is converted to the gate-on voltage. In this case, the initialization voltage may be lower than the driving power and greater than the common power. Since the above-described driving current of the pixel circuit 120 is not affected by the driving power, a uniform image quality may be realized in a high-resolution display device.

The pixel circuit 120 according to the exemplary embodiment of the present specification is not limited to the configuration of the above-described T1 transistors T1 to T5 transistors T5, the driving transistor DT, and the capacitor Cst, but a separate emission It may further include an auxiliary transistor and/or auxiliary capacitor controlled by a signal.

3 is a plan view illustrating a sub-pixel in which an LED element is disposed according to an embodiment of the present specification.

A plan view showing any one of the sub-pixels SP among the sub-pixels SP1, SP2, and SP3 constituting the unit pixel shown in FIG. 2, wherein the sub-pixel SP includes an LED element 160 and a pixel circuit ( 120).

The pixel circuit 120 is disposed in one area of the sub-pixel SP and the LED element 160 is disposed in another area. The pixel circuit 120 and the pixel electrode 150 connected to the LED element 160 are disposed to provide a driving current to the LED element 160 , and the pixel electrode 150 is connected through the second contact hole CH2 . It is in contact with the pixel connection electrode 125 of the pixel circuit 120 . In addition, the LED element 160 is connected to the common electrode 140 , and the common electrode 140 is connected to the common connection electrode 127 through the first contact hole CH1 .

4 and 5 are cross-sectional views of sub-pixels on which an LED device is disposed according to an exemplary embodiment of the present specification, respectively, cut in different directions.

FIG. 4 is a cross-sectional view taken along line A-A' of FIG. 3 and shows a connection relationship with the pixel circuit 120 . Referring to FIG. 4 , each sub-pixel SP1 , SP2 , and SP3 of the display device 100 according to an exemplary embodiment of the present specification includes a pixel circuit 120 , a protective layer 113 , an LED element 160 , and an insulating layer. layers 142 , 144 , a pixel electrode 150 , and a common electrode 140 .

As described with reference to FIG. 2 , the pixel circuit 120 may include first to fifth transistors T1 to T5 , a driving transistor DT, and a capacitor Cst. In FIG. 4 , the T3 transistor T3 and the LED device 160 connected to the LED device 160 are representatively shown and will be described.

The T3 transistor T3 includes a gate electrode GE, a semiconductor layer SCL, a source electrode SE, and a drain electrode DE.

The gate electrode GE is formed of the same material on the same layer as the gate line GL on the substrate 110 and is covered by the gate insulating layer 112 . The gate electrode GE is a semiconductor such as silicon (Si) or a conductive metal, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni). ), neodymium (Nd), and copper (Cu), or an alloy of two or more, or a multilayer thereof. The gate insulating layer 112 may be formed of a single layer or a plurality of layers made of an inorganic material, and may be made of silicon oxide (SiOx), silicon nitride (SiNx), or the like. The gate electrode of the T3 transistor T3 may branch or protrude from the emission line EL.

The semiconductor layer SCL is provided in a preset pattern shape on the gate insulating layer 112 to overlap the gate electrode GE. The semiconductor layer SCL may be formed of a semiconductor material made of any one of amorphous silicon, polycrystalline silicon, oxide, and an organic material, but is not limited thereto.

The source electrode SE may be disposed to overlap one side of the semiconductor layer SCL, and may be formed of the same material as that of the data line DL and the driving power line DPL.

The drain electrode DE is disposed to be spaced apart from the source electrode SE while overlapping the other side of the semiconductor layer SCL, and is formed together with the same material on the same layer as the source electrode SE.

The source electrode SE and the drain electrode DE may be formed of a semiconductor such as silicon (Si) or a conductive metal, for example, molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium ( Ti), nickel (Ni), neodymium (Nd), and copper (Cu) may be any one, an alloy of two or more, or a multilayer thereof.

The protective layer 113 is provided on the entire front surface of the substrate 110 to cover the pixel circuit 120 . The passivation layer 113 may provide a flat surface while protecting the pixel circuit 120 . The protective layer 113 according to an embodiment of the present specification may be made of an organic material such as benzocyclobutene or photo acryl. In some cases, the passivation layer 113 may separately include a passivation layer protecting the pixel circuit 120 and a planarization layer planarizing the step difference between the pixel circuit 120 .

The LED element 160 is electrically connected to the pixel circuit 120 and the common power line CPL to emit light by a current flowing from the pixel circuit 120 to the common power line CPL. The LED device 160 according to an embodiment of the present specification includes a first electrode 162 , an active layer 164 , and a second electrode 166 . The first electrode 162 of the LED device 160 according to an embodiment of the present specification is a p-type electrode and is an anode terminal, and the second electrode 166 is an n-type electrode and is a cathode terminal. The LED element 160 emits light by recombination of electrons and holes according to a current flowing between the first electrode 162 and the second electrode 166 .

The n-type semiconductor layer is a semiconductor layer in which free electrons having a negative charge move as carriers to generate a current, and may be made of an n-GaN-based material. The n-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, or the like, and Si, Ge, Se, Te, C, etc. may be used as impurities used for doping the n-type semiconductor layer.

The active layer 164 is disposed on the n-type semiconductor layer and may have a multi-quantum well (MQW) structure including a well layer and a barrier layer having a higher band gap than the well layer. For example, the active layer 164 may have a multi-quantum well structure such as InGaN/GaN.

The p-type semiconductor layer is a semiconductor layer in which positively charged holes move as carriers to generate a current, and may be made of a p-GaN-based material. The p-GaN-based material may be GaN, AlGaN, InGaN, AlInGaN, or the like, and Mg, Zn, Be, etc. may be used as impurities used for doping the p-type semiconductor layer.

An auxiliary electrode for forming an ohmic contact may be formed on the p-type semiconductor layer. Since the LED element 160 needs to be connected to the pixel electrode 150 while being implanted in the panel, the auxiliary electrode may contact the pixel electrode 150 to receive a driving current through the T3 transistor T3 . For example, in the case of a top emission type display device, the auxiliary electrode may be a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

The LED device 160 according to an embodiment of the present specification may be attached by forming the adhesive member 130 on the protective layer 113 .

The insulating layers 142 and 144 are formed on the protective layer 113 and the adhesive member 130 to cover the LED device 160 . The insulating layers 142 and 144 are formed on the protective layer 113 to have a thickness sufficient to cover the entire surface of the protective layer 113 , where the LED element 160 is disposed, and the remaining entire surface. The insulating layers 142 and 144 may be planarization layers having a multilayer structure including the first insulating layer 142 and the second insulating layer 144 . The insulating layers 142 and 144 provide a flat surface on the protective layer 113 and the adhesive member 130 , and serve to fix the position of the LED element 160 .

The pixel electrode 150 connects the first electrode 162 of the LED device 160 to the drain electrode DE of the T3 transistor T3. In some cases, the first electrode 162 of the LED element 160 may be connected to the source electrode SE of the T3 transistor T3. The pixel electrode 150 connected to the first electrode 162 of the LED element 160 may be defined as an anode electrode or a first connection electrode. The pixel electrode 150 is provided on the insulating layers 142 and 144 , and passes through the insulating layers 142 and 144 and the adhesive member 130 to contact the pixel connection electrode 125 connected to the drain electrode DE. . The pixel connection electrode 125 is formed on the passivation layer 113 and contacts the drain electrode DE of the T3 transistor T3 through a contact hole formed in the passivation layer 113 . The pixel electrode 150 may be formed of a transparent conductive material when the display device 100 is a top emission type, and may be formed of a light reflective conductive material when the display device 100 is a bottom emission type. The transparent conductive material may be indium tin oxide (ITO) or indium zinc oxide (IZO), but is not limited thereto. The light reflective conductive material may be, but is not limited to, Al, Ag, Au, Pt, or Cu. The pixel electrode 150 made of a light reflective conductive material may be formed of a single layer including a light reflective conductive material or a multi-layer in which single layers are stacked.

The common electrode 140 electrically connects the second electrode 166 of the LED element 160 and the common power line CPL, and may be defined as a cathode electrode or a second connection electrode, and is a pixel electrode 150 . It may be made of the same material as The common electrode 140 is provided on the adhesive member 130 to contact the lower surface of the second electrode 166 of the LED element 160 and is connected to the common power line CPL through the common connection electrode 127 . The common power line CPL is formed between the substrate 110 and the gate insulating layer 112 , and the common connection electrode 127 is on the protective layer 113 and is made of the same material as the pixel connection electrode 125 . is formed with The common connection electrode 127 is in contact with the common power line CPL through a contact hole formed in the protective layer 113 and the gate insulating layer 112 , and the common electrode 140 is a contact hole formed in the adhesive member 130 . through the common connection electrode 127 . In this case, the position of the common power line CPL is not limited to between the substrate 110 and the gate insulating layer 112 . The common power line CPL may be formed of the same material on the same layer as the gate electrode GE of the T3 transistor T3 or the source electrode SE and the drain electrode DE under the passivation layer 113 . Accordingly, the common power line CPL may be formed between the gate insulating layer 112 and the passivation layer 113 .

FIG. 5 is a cross-sectional view taken along line B-B' of FIG. 3 and shows a stacked structure between the LED element 160 and the pixel electrode 150 and the common electrode 140 . Referring to FIG. 5 , as described with reference to FIG. 4 , the gate insulating layer 112 and the protective layer 113 are formed on the substrate 110 , and the region where the LED device 160 is to be attached on the protective layer 113 . The adhesive member 130 is provided.

A common electrode 140 is provided on the adhesive member 130 , and the common electrode 140 is positioned in the groove AH formed on the upper surface of the adhesive member 130 . In addition, by forming the width CW of the common electrode 140 smaller than the length LL of the LED device 160 , the LED device 160 can be fixed to the adhesive member 130 , and It may be electrically connected to the second electrode 166 . The thickness of the adhesive member 130 is formed to be about 5 μm or less, and the common electrode 140 is equal to or smaller than the thickness of the adhesive member 130 .

The LED element 160 is attached to the adhesive member 130 provided with the common electrode 140 , and insulating layers 142 and 144 are formed on the LED element 160 . In addition, a contact hole is provided in the second insulating layer 144 so that the LED element 160 and the pixel electrode 150 can contact each other. In this case, the width PW of the pixel electrode 150 is similar to the width CW of the common electrode 140 . However, since the width CW of the common electrode 140 affects the adhesive force between the LED element 160 and the adhesive member 130 , the width CW of the common electrode 140 is the width (CW) of the pixel electrode 150 . PW) may be smaller than

6 and 7 are cross-sectional views of an LED device according to an embodiment of the present specification, respectively.

6 is a cross-sectional view taken along line B-B' of FIG. 3 and shows another embodiment. 6 may further include a step compensation layer 170 in the structure of FIG. 5 . The step compensation layer 170 is provided on the protective layer 113 to compensate for the step difference due to the common electrode 140 formed under the LED element 160 . The step compensation layer 170 is disposed on both sides (along the Y axis) of the common electrode 140 , and is the sum of the width SW of the two step compensation layers 170 and the width CW of the common electrode 140 . may be less than or equal to the length LL of the LED element 160 . When the sum of the width SW of the two step compensation layers 170 and the width CW of the common electrode 140 is greater than the length LL of the LED device 160 , the step compensation layer 170 and the common electrode 140 may be overlapped, and in this case, a step corresponding to the thickness of the step compensation layer 170 may be generated, which may interfere with the adhesive force between the LED element 160 and the adhesive member 130 . In this case, the common electrode 140 may be formed on the adhesive member 130 without providing a groove in the adhesive member 130 . In order to compensate for the step difference caused by the common electrode 140 , the thickness of the common electrode 140 and the thickness of the step difference compensation layer 170 are the same. Accordingly, without forming a groove in the adhesive member 130 , the common electrode 140 and the common electrode 140 under the adhesive member 130 are provided with a step difference compensation layer 170 having the same thickness as the common electrode 140 . By doing so, the adhesive force between the LED element 160 and the adhesive member 130 can be improved.

7 is a cross-sectional view taken along line B-B' of FIG. 3 and shows another embodiment. 7 may further include a step compensation structure 168 in the structure of FIG. 5 . The step compensation structure 168 is formed on the growth substrate before the LED device 160 is transferred to the substrate 110 . The step compensation structure 168 may be patterned on the second electrode 166 of the LED device 160 formed on the growth substrate. The step compensation structure 168 may be made of an inorganic material, for example, silicon oxide, and is formed to have the same thickness as that of the common electrode 140 .

The common electrode 140 is provided on the adhesive member 130 , and the LED device 160 provided with the step compensation structure 168 is transferred onto the adhesive member 130 and the common electrode 140 . In this case, the sum of the width CW of the common electrode 140 and the width TW of the two step compensation structures 168 may be smaller than the length LL of the LED device 160 . When the sum of the width CW of the common electrode 140 and the width TW of the two step compensation structures 168 is equal to the length LL of the LED device 160, the step compensation structure ( Since the common electrode 168 and the common electrode 140 may be overlapped and attached, the width of the common electrode 140 or the step compensation structure 168 may be adjusted with a process margin.

8A to 8E are diagrams illustrating a step of implanting an LED device according to an embodiment of the present specification of FIG. 4 to a panel.

As described above, since the area of the horizontal LED device is twice as large as that of the vertical LED device having the same light emitting area, the material cost of the LED device is increased, so it is difficult to apply to a high-resolution, large-screen display device. Accordingly, a method of manufacturing a display device including a vertical LED element formed at a relatively low cost will be described below.

8A is a process for transferring the LED element 160 to the panel. The pixel circuit 120 , the protective layer 113 covering the pixel circuit 120 , the pixel connection electrode 125 , and the common connection electrode 127 . An adhesive member 130 for transferring the LED element 160 is formed on the formed substrate 110 . The adhesive member 130 is coated on the entire front surface of the protective layer 113 to a predetermined thickness, and a portion of the adhesive member 130 coated on the front surface of the protective layer 113 where the contact holes CH1 and CH2 are to be provided. It is removed by a contact hole forming process. Alternatively, the adhesive member 130 may be applied on the protective layer 113 through a printing process such as inkjet, except for regions where the contact holes CH1 and CH2 are to be provided.

Referring to FIG. 8B , the common electrode 140 is formed on the common connection electrode 127 exposed by the first contact hole CH1 . The common electrode 140 is formed by occupying a portion of a region to which the LED device 160 is to be attached in order to contact the second electrode 166 of the LED device 160 . Since the common electrode 140 is an electrode for providing the common power applied through the common power line CPL to the second electrode 166 , the common electrode 140 covers the second contact hole CH2 formed on the pixel connection electrode 125 . A patterning process for removing the common electrode 140 is performed. Accordingly, the pixel connection electrode 125 formed in the second contact hole CH2 is exposed to the air, and the common electrode 140 comes into contact with the bottom surface of the second electrode 166 and the common connection electrode 127 . The second electrode 166 is electrically connected to the common power line CPL.

Referring to FIG. 8C , the LED element is attached to the adhesive member 130 and the second electrode 166 . In order to transfer the LED device 160 onto the adhesive member 130 , a substrate separation process of separating the LED device 160 from the growth substrate is performed. The substrate separation process may be laser lift-off (LLO), chemical lift-off (CLO), a method of applying pressure with a stamp, or the like.

The LED device 160 separated from the growth substrate and having the bottom surface of the second electrode 166 exposed is disposed on the adhesive member 130 to overlap the second electrode 166 . The adhesive member 130 may primarily fix the LED element 160 to the panel while in contact with a portion of the bottom surface of the LED element 160 .

Referring to FIG. 8D , the LED device 160 attached to the panel through the adhesive member 130 and the first insulating layer 142 on the front surface of the substrate 110 are patterned on the substrate 110 . The first insulating layer 142 is deposited on the entire surface of the LED device 160 , the common electrode 140 , and the substrate 110 and the first insulating layer 142 is formed on the second contact hole CH2 through a photolithography process. It is formed through a step of removing the insulating layer 142 . The first insulating layer 142 is formed to have a thickness lower than the height of the LED device 160 to expose the upper portion of the LED device 160 in a subsequent process. In this case, the first insulating layer 142 surrounds all of the second electrode 166 of the LED device 160 , surrounds a portion of the active layer 164 , and is formed to a thickness capable of exposing the first electrode 162 .

Then, the second insulating layer 144 is patterned on the substrate 110 . The second insulating layer 144 is deposited on the front surface of the LED device 160 and the substrate 110 and the second insulating layer 144 on the second contact hole CH2 and the first electrode 162 is removed. formed through steps. The second insulating layer 144 is formed to cover the LED device 160 with a thickness higher than that of the LED device 160 . In addition, the first electrode 162 on the LED device 160 and the second insulating layer 144 on the second contact hole CH2 are removed through a photolithography process.

Subsequently, referring to FIG. 8E , the pixel electrode 150 is an electrode for providing a voltage applied through the drain electrode DE of the T3 transistor T3 to the first electrode 162 , and the pixel electrode 150 is The second contact hole CH2 formed on the upper portion of the LED device 160 exposed by the second insulating layer 144 and on the pixel connection electrode 125 is formed on the substrate 110 . In this case, a patterning process may be performed on the pixel electrode 150 to remove a portion formed in a region other than the portion for electrically connecting the first electrode 162 and the pixel connection electrode 125 . Accordingly, the pixel electrode 150 insulated from the adjacent sub-pixels may be formed.

The display device and the method of manufacturing the display device according to the exemplary embodiment of the present specification may be described as follows.

In the display device according to the exemplary embodiment of the present specification, the display device includes a vertical LED device arranged on a substrate and including a first electrode, an active layer, and a second electrode, a first connection electrode connected to the first electrode, and a second electrode A second connection electrode connected to the electrode, a pixel circuit providing a driving current to the vertical LED element, and an adhesive member contacting the second electrode. In addition, the second connecting electrode and the adhesive member overlap the vertical LED element between the substrate and the vertical LED element. Accordingly, the LED element can be stably attached to the substrate and a high-resolution trademark display device can be realized.

According to another feature of the present specification, the second connection electrode may be in a groove formed in the adhesive member.

According to another feature of the present specification, a step compensation layer overlapping the vertical LED device may be further included between the substrate and the vertical LED device. In addition, the second connection electrode may be on the adhesive member, and the step difference compensating layer may be on the bottom of the adhesive member. In addition, the step compensation layer is disposed on both sides of the second connection electrode, and the sum of the width of the second connection electrode and the width of the step compensation layer disposed on both sides of the second connection electrode is equal to or smaller than the length of the vertical LED element. can

According to another feature of the present specification, the vertical LED device may further include a step compensation structure, and the step compensation structure may be disposed on the same layer as the second connection electrode. In addition, the step compensation structure is disposed on both sides of the second connection electrode, and the sum of the width of the second connection electrode and the width of the step compensation layer disposed on both sides of the second connection electrode may be smaller than the length of the vertical LED device. .

According to another feature of the present specification, a protective layer may be further included on the pixel circuit, and the second connection electrode may be connected to a common power line through a contact hole in the protective layer and the adhesive member.

According to another feature of the present specification, it may include a first insulating layer surrounding the vertical LED element on the adhesive member and a second insulating layer on the first insulating layer. In addition, the second insulating layer may not cover a part or all of the upper portion of the vertical LED device. In addition, the first connection electrode may be connected to the pixel circuit through a contact hole in the first insulating layer, the second insulating layer, and the adhesive member.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: display device
110: substrate
112: gate insulating layer
113: protective layer
130: adhesive member
142: first insulating layer
144: second insulating layer
160: LED element
162: first electrode
164: active layer
166: second electrode

Claims (11)

a vertical LED device arranged on a substrate and including a first electrode, an active layer, and a second electrode;
a first connection electrode connected to the first electrode;
a second connection electrode connected to the second electrode;
a pixel circuit providing a driving current to the vertical LED element; and
an adhesive member in contact with the second electrode;
The second connection electrode and the adhesive member overlap the vertical LED element between the substrate and the vertical LED element. According to claim 1,
and the second connection electrode is in a groove formed in the adhesive member. According to claim 1,
and a step compensation layer overlapping the vertical LED device between the substrate and the vertical LED device. 4. The method of claim 3,
The second connection electrode is on the adhesive member,
and the step difference compensating layer is under the adhesive member. 4. The method of claim 3,
The step difference compensation layer is disposed on both sides of the second connection electrode,
The sum of the width of the second connection electrode and the width of the step difference compensation layer disposed on both sides of the second connection electrode is equal to or smaller than the length of the vertical LED element. According to claim 1,
The vertical LED device further comprises a step compensation structure,
The step compensation structure is disposed on the same layer as the second connection electrode. 7. The method of claim 6,
The step compensation structure is disposed on both sides of the second connection electrode,
The sum of the width of the second connection electrode and the width of the step difference compensation layer disposed on both sides of the second connection electrode is smaller than the length of the vertical LED element. According to claim 1,
Further comprising a protective layer on the pixel circuit,
and the second connection electrode is connected to a common power line through a contact hole in the protective layer and the adhesive member. According to claim 1,
a first insulating layer surrounding the vertical LED element on the adhesive member; and
and a second insulating layer on the first insulating layer. 10. The method of claim 9,
The second insulating layer does not cover a part or all of an upper portion of the vertical LED element. 10. The method of claim 9,
and the first connection electrode is connected to the pixel circuit through a contact hole in the first insulating layer, the second insulating layer, and the adhesive member.

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