LED display device

Abstract

In an LED display device according to an embodiment of the disclosure, the LED display device includes: a second pixel driving circuit on a substrate; an LED element attached to an area not overlapping the second pixel driving circuit, including a first LED element, a second LED element, and a growth substrate, and providing a dual emission spectrum; an element fixing layer surrounding the LED element; a first pixel driving circuit on the element fixing layer; and an element protection layer on the first pixel driving circuit. In addition, the first LED element is controlled by the first pixel driving circuit, and the second LED element is controlled by the second pixel driving circuit. Therefore, the LED display device provides a dual emission spectrum, high brightness and high precision can be achieved, and pixel defects can be prevented.

Description

Technical Field

[0001] This disclosure relates to light-emitting diode (LED) display devices, and more specifically, to LED display devices using LEDs that provide dual emission spectra. Background Technology

[0002] The applications of liquid crystal displays (LCDs), organic light-emitting diode displays (OLEDs), and quantum dot displays (QDs), which are already widely used, are gradually expanding.

[0003] In the aforementioned display device, multiple light-emitting elements are disposed on a substrate of the display device to realize an image, and a driving element for supplying driving signals or driving currents for controlling the individual emission of each light-emitting element is disposed on the substrate together with the light-emitting elements. Information is displayed on the substrate by interpreting (driving) the multiple light-emitting elements disposed on the substrate according to the arrangement of the information to be displayed.

[0004] Because liquid crystal displays (LCDs) are not self-emissive, a backlight unit is required on the back surface of the LCD to emit light. The backlight unit increases the thickness of the LCD, limits the display device's ability to achieve various designs such as flexible or circular designs, and reduces brightness and response time.

[0005] Meanwhile, display devices with self-emissive elements can be made thinner than display devices with a light source, and therefore can be flexible and foldable. Display devices with self-emissive elements can be organic light-emitting display devices that include organic materials as a light-emitting layer or LED display devices that use LEDs as light-emitting elements. Since organic light-emitting display devices and LED display devices do not require a separate light source, they can be used as thinner or various types of display devices.

[0006] However, in organic light-emitting display devices using organic materials, there is a need for various technical configurations to minimize oxygen and moisture penetration, as defective pixels may occur due to oxidation between the organic light-emitting layer and the electrodes caused by the penetration of moisture and oxygen.

[0007] To address the aforementioned issues, research and development of display devices using LEDs, which utilize inorganic materials as light-emitting elements, has been ongoing in recent years. LED display devices have garnered attention as the next generation of display devices due to their high image quality and high reliability. Summary of the Invention

[0008] Technical issues

[0009] An LED is a semiconductor light-emitting element that emits light when an electric current passes through it. LEDs are widely used in various display devices, such as lighting fixtures, TVs, signage displays, and tile displays. An LED element consists of an n-type electrode, a p-type electrode, and an active layer between them. Each of the n-type and p-type electrodes is formed of semiconductor material. When current flows through the n-type and p-type electrodes, electrons from the n-type electrode and holes from the p-type electrode combine in the active layer to emit light.

[0010] LED devices are composed of compound semiconductors such as GaN, and due to the nature of inorganic materials, high currents can be injected to achieve high brightness. LED devices also exhibit high reliability due to their low susceptibility to environmental influences such as heat, moisture, and oxygen.

[0011] In addition, since the internal quantum efficiency of LED elements is 90%, which is higher than that of organic light-emitting diodes, they can display high-brightness images and have the advantage of enabling display devices with low power consumption.

[0012] Furthermore, unlike organic light-emitting display devices, because inorganic materials are used, there is no need for a separate encapsulation film or substrate to minimize oxygen and moisture penetration to a level where their effects are insignificant. Therefore, an advantage is that the non-display area of ​​the display device can be minimized, which is a margin area that could be created by providing an encapsulation film or substrate.

[0013] LED elements can be categorized into horizontal LED elements, where n-type and p-type electrodes are formed on the same surface of the LED element, and vertical LED elements, where the n-type and p-type electrodes face each other. Compared to vertical LED elements, horizontal LED elements have a smaller light-emitting area and a higher current density, making it difficult to generate high brightness and potentially reducing efficiency. Furthermore, since the area of ​​a horizontal LED element is twice that of a vertical LED element with the same light-emitting area, it increases the material cost of the LED element.

[0014] Therefore, the inventors of this disclosure have recognized the problems mentioned above and have invented an LED display device that uses LED elements that provide a dual emission spectrum to achieve high brightness and high definition.

[0015] The objective of embodiments of this disclosure is to provide an LED display device capable of controlling two active layers using different driving circuits, the two active layers being included in LED elements providing dual emission spectra.

[0016] The objective of embodiments of this disclosure is to provide an LED display device that can provide an alternative LED element when defects occur, using an LED element that provides a dual emission spectrum.

[0017] The objective of embodiments of this disclosure is to provide a double-sided LED display device using LED elements that provide dual emission spectra.

[0018] The purpose of this disclosure is not limited to the purposes mentioned above, and other purposes not mentioned will be clearly understood by those skilled in the art from the following description.

[0019] Technical solution

[0020] In an LED display device according to an embodiment of the present disclosure, the LED display device includes: a second pixel driving circuit on a substrate; LED elements attached to a region not overlapping with the second pixel driving circuit and including a first LED element, a second LED element, and a growth substrate; an element fixing layer surrounding the LED elements; the first pixel driving circuit on the element fixing layer; and an element protective layer on the first pixel driving circuit, wherein the first LED element is controlled by the first pixel driving circuit, and the second LED element is controlled by the second pixel driving circuit. Therefore, the LED display device provides a dual emission spectrum, enabling high brightness and high definition, and preventing pixel defects.

[0021] In an LED display device according to an embodiment of the present disclosure, the LED display device includes: a substrate divided into a display area and a non-display area, wherein a unit pixel is disposed in the display area; a second pixel driving circuit on the substrate; a second connection electrode electrically connected to the second pixel driving circuit; a second LED element contacting the second connection electrode; a first LED element disposed on the second LED element; a first pixel driving circuit disposed on the first LED element; and a first connection electrode electrically connecting the first LED element and the first pixel driving circuit. Therefore, the LED display device provides a dual emission spectrum, achieving high brightness and high definition, and preventing pixel defects.

[0022] Details of other implementation methods are included in the detailed description and accompanying drawings.

[0023] Beneficial effects

[0024] According to embodiments of this disclosure, a subpixel includes two LED elements, and these two LED elements are controlled by different pixel driving circuits, enabling the LED display device to achieve high brightness and high definition, and to prevent pixel defects.

[0025] Furthermore, according to embodiments of this disclosure, the LED element includes a first LED element and a second LED element, which are attached to the same growth substrate, and a reflective layer is disposed on the same layer as the growth substrate. Therefore, a double-sided light-emitting LED display device can be realized.

[0026] Since the content of this disclosure, which describes the technical problem to be solved, the technical solution, and the effect, does not specify the essential features of the claims, the scope of the claims is not limited to the matters described in the content of this disclosure. Attached Figure Description

[0027] Figure 1 This is a plan view showing an LED display device according to an embodiment of the present disclosure.

[0028] Figure 2 It shows according to Figure 1 A pixel circuit diagram showing the sub-pixel configuration of an LED display device according to an embodiment.

[0029] Figure 3 This is a cross-sectional view of an LED display device according to an embodiment of the present disclosure, in which LED elements providing dual emission spectra are provided.

[0030] Figures 4 to 9 This is a cross-sectional view showing a method for manufacturing an LED element providing a dual emission spectrum according to an embodiment of the present disclosure.

[0031] Figures 10 to 15 This is a cross-sectional view showing an implantation method for providing a dual-emission spectrum LED element onto a panel according to an embodiment of the present disclosure.

[0032] Figure 16 This is a cross-sectional view showing an LED display device according to an embodiment of the present disclosure.

[0033] Figure 17 This is a cross-sectional view showing an LED display device according to an embodiment of the present disclosure.

[0034] Figure 18 This is a cross-sectional view showing an LED display device according to an embodiment of the present disclosure.

[0035] Figure 19 It shows that there are settings. Figure 2 A planar diagram of a sub-pixel in the pixel driving circuit.

[0036] Figure 20 It is along Figure 19 A cross-sectional view taken from line A-A'. Detailed Implementation

[0037] The advantages and features of the present invention, as well as the methods of implementing it, will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and these embodiments are only intended to allow the disclosure of the present invention to be complete. The present invention has been provided to fully convey its scope to those skilled in the art, and the invention is defined only by the scope of the claims.

[0038] The shapes, dimensions, proportions, angles, numbers, etc., disclosed in the accompanying drawings used to explain embodiments of the present invention are illustrative, and the present invention is not limited to what is shown. Throughout this disclosure, the same reference numerals refer to the same elements. Furthermore, in describing the present invention, detailed descriptions of related known technologies may be omitted if it is determined that such detailed descriptions unnecessarily obscure the subject matter of the present invention. When terms such as "comprising," "having," or "including" are used in this disclosure, other parts may be added unless "only" is used. When components are expressed in a singular form, the inclusion of the plural form is included unless a specific description is provided.

[0039] When interpreting a component, it is interpreted as including a margin range, even if there is no separate explicit description.

[0040] In the case of descriptions of positional relationships, for example, when the positional relationship between two parts is described as "on," "above," "below," "next to," etc., one or more other parts may be located between the two parts unless "exactly," "directly," or "adjacent" is described.

[0041] In the context of descriptions of temporal relationships, such as when the temporal relationship is described as "after", "following", "after", "before", etc., it includes discontinuous cases unless "immediately after" or "directly" is described.

[0042] Each feature of the various embodiments of this disclosure may be connected or combined with each other in part or in whole, and may be technically interlocked and driven. Each of the embodiments may be implemented independently of each other, or may be implemented together with related relationships.

[0043] In the following description, an LED display device according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0044] Figure 1 This is a plan view showing an LED display device according to an embodiment of the present disclosure, and Figure 2 It shows according to Figure 1A pixel circuit diagram showing the sub-pixel configuration of an LED display device according to an embodiment.

[0045] Reference Figure 1 and Figure 2 According to an embodiment of the present disclosure, an LED display device 100 includes a substrate 110, which is divided into a display area DA in which a plurality of unit pixels UP are present and a non-display area NDA.

[0046] The unit pixel UP may include a plurality of sub-pixels SP1, SP2, and SP3 present on the front surface 110a of the substrate 110. Typically, sub-pixels SP1, SP2, and SP3 emit red light, blue light, and green light, respectively, but are not limited thereto. The unit pixel UP may also include a unit pixel that emits white light.

[0047] The substrate 110 is an array substrate in which transistors are formed, and includes a plastic material or a glass material.

[0048] The substrate 110 in the embodiments may include an opaque material or a colored polyimide material. In this case, a backplate coupled to the rear surface of the substrate 110 may also be included to hold the substrate 110 in a planar state. The backplate according to the example may include a plastic material, such as polyethylene terephthalate. The substrate 110 according to the example may be a glass substrate. For example, the glass substrate 110 may be a thin glass substrate having a thickness of 100 μm or less and may have flexible properties.

[0049] In addition, the substrate 110 can be divided into a bonding of two or more substrates or two or more layers.

[0050] The non-display area NDA can be defined as the area on the substrate 110 other than the display area DA. Compared with the display area DA, it can have a relatively narrow width (or size) and can be defined as a border area.

[0051] Each of a plurality of unit pixels UP is disposed within a display area DA. In this case, each of the plurality of unit pixels UP has a predetermined first reference pixel spacing along the X-axis direction and a predetermined second reference pixel spacing along the Y-axis direction, and is disposed within the display area DA. The first reference pixel spacing and the second reference pixel spacing can be defined, respectively, as the distance between the center portions of adjacent unit pixels UP in the X-axis direction or the Y-axis direction.

[0052] In addition, the distance between the sub-pixels SP1, SP2 and SP3 that constitute the unit pixel UP can be defined as the first reference sub-pixel spacing and the second reference sub-pixel spacing, similar to the first reference pixel spacing and the second reference pixel spacing.

[0053] In the display device 100 including LED elements 200, the width of the non-display area NDA can be equal to or less than the pixel pitch or sub-pixel pitch. Since the non-display area NDA is equal to or less than the pixel pitch or sub-pixel pitch, a tiled display device with substantially no border area can be achieved by the display device 100 having a non-display area NDA with a width equal to or less than the pixel pitch or sub-pixel pitch.

[0054] To achieve a tiled display device or multi-screen display device in which the border area is substantially non-existent or minimized, the first reference pixel pitch, the second reference pixel pitch, the first reference sub-pixel pitch, and the second reference sub-pixel pitch can be constantly maintained within the display area DA of the display device 100. Alternatively, when the display area DA is defined as multiple areas and the lengths of the aforementioned pitches differ in each of these areas, the pixel pitch in the area adjacent to the non-display area NDA can be wider than in other areas, allowing the size of the border area to be relatively smaller than the pixel pitch. In this case, since display devices 100 with different pixel pitches may cause image distortion, image processing is performed by comparing and sampling with adjacent areas, taking into account the pixel pitch, to eliminate image distortion while reducing the border area.

[0055] Reference Figure 2 This describes a pixel driving circuit for one of the sub-pixels SP1, SP2, and SP3 constituting a unit pixel UP of a display device 100. Pixel driving lines are disposed on the front surface 110a of a substrate 110 to supply necessary signals to each of the plurality of sub-pixels SP1, SP2, and SP3. Pixel driving lines according to embodiments of this disclosure include: a horizontal axis 150 connected to pixels arranged along the X-axis to provide signals; and a vertical axis 140 connected to pixels arranged along the Y-axis to provide signals. The horizontal axis 150 may also be referred to as a gate line and may include a scan line providing a scan signal Scan and / or a light-emitting line providing a light-emitting signal. The vertical axis 140 may include a data line providing a data signal Vdata and a power line providing a power signal. In this case, the power signal may include a high-potential power supply voltage Vdd and a common power supply voltage Vcom. In some cases, the line providing the common power supply voltage Vcom may be included in the horizontal axis 150.

[0056] A horizontal axis 150 is disposed on the front surface 110a of the substrate 110. The horizontal axis 150 extends along the horizontal axis direction X of the substrate 110 and is spaced apart from each other at regular intervals along the vertical axis direction Y.

[0057] The vertical axis 140 intersects the horizontal axis 150 and is disposed on the front surface 110a of the substrate 110. The vertical axis 140 extends along the vertical axis direction Y of the substrate 110 and is spaced apart from each other at regular intervals along the horizontal axis direction X.

[0058] Each of subpixels SP1, SP2, and SP3 is set in a subpixel region defined by the horizontal axis 150 and the vertical axis 140. Furthermore, each of subpixels SP1, SP2, and SP3 can be defined as the region of the smallest unit that emits actual light.

[0059] Three adjacent sub-pixels SP1, SP2, and SP3 can constitute a unit pixel UP for color display. For example, a unit pixel UP includes red sub-pixels SP1, green sub-pixels SP2, and blue sub-pixels SP3 that are adjacent to each other along the horizontal axis X, and may also include a white sub-pixel to improve brightness. Alternatively, in the case of implementing an LED display device according to an embodiment of the present disclosure that includes LED elements providing a double-sided emission spectrum, two adjacent sub-pixels can constitute a unit pixel for color display. In this case, the two sub-pixels can be configured to emit red, green, and blue light. For example, one of the two sub-pixels can emit red light, and the other sub-pixel can emit green and blue light.

[0060] Each of the plurality of sub-pixels according to embodiments of the present disclosure includes a pixel driving circuit and an LED element 200.

[0061] A pixel driving circuit is disposed in a circuit region defined in each sub-pixel and connected to adjacent gate lines, adjacent data lines, and adjacent power lines. In response to a scan signal Scan provided via a scan line, the pixel driving circuit controls the current through the LED element 200 based on a high-potential power supply voltage Vdd provided via a high-potential power supply line and a data voltage Vdata provided via a data line. The pixel driving circuit according to an embodiment of this disclosure includes a first transistor T1, a second transistor T2, and a capacitor Cst. The first transistor T1 and the second transistor T2 may be configured as NMOS type thin-film transistors. However, embodiments of this disclosure are not limited thereto. For example, the first transistor T1 may be configured as an NMOS type thin-film transistor with good cutoff current characteristics, and the second transistor T2 may be configured as a PMOS type thin-film transistor with good response characteristics.

[0062] LED element 200 is mounted on each of the sub-pixels. LED element 200 is electrically connected to the pixel driving circuit and high-potential power line of the corresponding sub-pixel, such that light is emitted through the current supplied from the driving transistor, i.e., the second transistor T2, to the p-type electrode of the LED element 200. The LED element 200 according to embodiments of this disclosure is an LED element providing a dual emission spectrum and can be an optical element or light-emitting diode chip emitting one of red, green, blue, white, red and green, red and blue, or green and blue light. For example, when LED element 200 emits red light, it can emit red light of the same wavelength or red light of different wavelengths. In this case, the light-emitting diode chip can have a diameter of 1 to 100 μm. 2 The size of the LED chip can be smaller than that of the light-emitting area of ​​the sub-pixel region, excluding the circuit area occupied by the pixel driving circuit.

[0063] The second transistor T2 is a driving element that controls the current flowing through the LED element 200 based on the voltage between its gate electrode and source electrode. The second transistor T2 includes a gate electrode connected to the first node n1, a drain electrode connected to the second node n2, and a source electrode connected to the third node n3.

[0064] The first transistor T1 is connected between the first node n1 and the fourth node n4, and is switched according to the scan signal Scan. The gate electrode of the first transistor T1 is connected to the scan line to which the scan signal Scan is applied, and the fourth node n4 is connected to the data voltage line. When the first transistor T1 is turned on, the data voltage Vdata is transmitted to the gate electrode of the second transistor T2, and the second transistor T2 is turned on.

[0065] The capacitor Cst includes a first electrode and a second electrode, which are connected to a first node n1 and a third node n3, respectively. The capacitor Cst is formed in the overlapping region of the first and second electrodes. The second electrode of the capacitor Cst is connected to the third node n3 and fixed to a common power supply voltage Vcom, and the first electrode stores a data voltage Vdata received from the first transistor T1. The data voltage Vdata stored in the capacitor Cst enables the second transistor T2 to provide the same drive current to the LED element 200 within one frame.

[0066] The pixel driving circuit according to the embodiments of this disclosure is not limited to the above-described configuration of the first transistor T1, the second transistor T2, and the capacitor Cst, but may also include a transistor controlled by an additional scan signal, a transistor controlled by a light emission signal, and / or an auxiliary capacitor.

[0067] Figure 3This is a cross-sectional view of an LED display device according to an embodiment of the present disclosure, in which LED elements providing dual emission spectra are provided.

[0068] Reference Figure 3 Each sub-pixel of the display device 100 according to an embodiment of the present disclosure includes an LED element 200, a first pixel driving circuit 310 and a second pixel driving circuit 320 for providing driving current to the LED element 200, a third insulating layer 105 for protecting and fixing the LED element 200, and electrodes for connecting the LED element 200 and the pixel driving circuits 310 and 320. The third insulating layer 105 may be referred to as an element fixing layer or a planarization layer.

[0069] For reference Figure 2 Each of the pixel driving circuits 310 and 320 can be implemented by including a first transistor T1, a second transistor T2, and a capacitor Cst. Figure 3 In the diagram, pixel driving circuits 310 and 320 are shown as blocks.

[0070] As described above, substrate 110 is a substrate for supporting components of LED display device 100, and may be an insulating substrate. For example, substrate 110 may be made of glass or resin, and may include flexible polymers or plastics.

[0071] The second pixel driving circuit 320 is disposed on the substrate 110, and a first insulating layer 101 for protecting the second pixel driving circuit 320 and reducing the step difference on the substrate caused by the second pixel driving circuit 320 is disposed on the second pixel driving circuit 320.

[0072] A second n-connection electrode 122 and a second p-connection electrode 152a are disposed on the first insulating layer 101. The second n-connection electrode 122 and the second p-connection electrode 152a are electrically connected to the second n-electrode 262 and the second p-electrode 252 of the LED element 200, respectively. The second n-connection electrode 122 electrically connects the second n-electrode 262 of the LED element 200 and the second pixel driving circuit 320, and the second p-connection electrode 152a electrically connects the high-potential power line and the second p-electrode 252.

[0073] A second insulating layer 102 is provided on the second n-connection electrode 122 and the second p-connection electrode 152a. The second insulating layer 102 includes contact holes exposing the second n-connection electrode 122 and the second p-connection electrode 152a for connecting the second n-connection electrode 122 and the second p-connection electrode 152a to the second n-electrode 262 and the second p-electrode 252. A reflective layer 104 for improving the light extraction efficiency of the LED element 200 is provided on the second insulating layer 102. The reflective layer 104 overlaps with the LED element 200. The reflective layer 104 is formed to expose the second n-connection electrode 122 and the second p-connection electrode 152a. The LED element 200 is attached to the exposed second n-connection electrode 122 and the exposed second p-connection electrode 152a on the reflective layer 104. In some cases, the reflective layer 104 may be omitted.

[0074] LED element 200 includes two active layers 231 and 232 and provides a dual emission spectrum. LED element 200 includes a growth substrate 201, n-type layers 211 and 212, active layers 231 and 232, p-type layers 241 and 242, n-electrodes 261 and 262, and p-electrodes 251 and 252. LED element 200 includes a first LED element and a second LED element implemented in a horizontal structure. The first LED element and the second LED element are formed with the growth substrate 201 between them. The first LED element includes a first n-type layer 211, a first active layer 231, a first p-type layer 241, a first n-electrode 261, and a first p-electrode 251, and the second LED element includes a second n-type layer 212, a second active layer 232, a second p-type layer 242, a second n-electrode 262, and a second p-electrode 252. A detailed description of the stacked structure of the first LED element and the second LED element will be described later.

[0075] The second n-connection electrode 122 exposed through the reflective layer 104 is connected to the second n-electrode 262 of the second LED element through the second bonding portion 412, and the second p-connection electrode 152a is connected to the second p-electrode 252 of the second LED element through the first bonding portion 402.

[0076] A third insulating layer 105 is formed on the second pixel driving circuit 320 and the LED element 200, and in the area excluding the contact hole, to planarize the display area DA. The third insulating layer 105 may be referred to as a planarization layer or a fixing layer.

[0077] A first pixel driving circuit 310 is disposed on a third insulating layer 105. The first pixel driving circuit 310 is connected to a first n-connection electrode 121 of the first LED element, and a first p-connection electrode 151a is connected to a common power supply line. In addition, a fourth insulating layer 106 for protecting the LED element 200 and the first pixel driving circuit 310 is disposed on the LED element 200 and the first pixel driving circuit 310.

[0078] Figures 4 to 9 This is a cross-sectional view showing a method for manufacturing an LED element providing a dual emission spectrum according to an embodiment of the present disclosure.

[0079] Reference Figure 4 A growth substrate 201 is prepared to form the electrodes of the LED element 200. The growth substrate 201 may include sapphire, silicon (Si), indium phosphide (InP), gallium arsenide (GaAs), etc. Sapphire or silicon can be mainly used to realize LED elements capable of expressing green or blue light, while gallium arsenide and indium phosphide can be mainly used to realize LED elements capable of expressing red light. In this case, the transmittance of the LED display device can be improved by later transferring the growth substrate 201 formed of gallium arsenide to a sapphire substrate. Alternatively, a sapphire substrate can be used instead of the growth substrate 201 formed of gallium arsenide.

[0080] A first n-type layer 211 is formed on one side of the growth substrate 201 using a chemical growth method. In this case, the chemical growth method can be MOCVD (metal-organic chemical vapor deposition). The first n-type layer 211 is a semiconductor layer in which negatively charged free electrons move as charge carriers to generate current, and can be made of a GaN-based material doped with n-type impurities (n-GaN). The GaN-based material can be GaN, AlGaN, InGaN, or AlInGaN, while Si, Ge, Se, Te, or C can be used as impurities for doping the first n-type layer 211. In some cases, a buffer layer, such as an undoped GaN-based semiconductor layer, can be additionally formed between the growth substrate 201 and the first n-type layer 211.

[0081] For example, to realize a first LED element that expresses blue or green light, the first n-type layer 211 may include two layers: a layer formed of undoped gallium nitride (un-GaN) and a layer formed of doped gallium nitride (n-GaN) obtained by doping it with an n-type impurity. For example, the n-type impurity may be one of Si, Ge, Se, Te, and C.

[0082] Alternatively, the first n-type layer 211 may be indium aluminum phosphide (n-AlInP) doped with n-type impurities. For example, to realize a first LED device that expresses red light, the first n-type layer 211 may be formed of indium aluminum phosphide (n-AlInP) doped with n-type impurities.

[0083] A first active layer 231 is formed on the first n-type layer 211. The first active layer 231 is disposed on the first n-type layer 211 and may have a multiple quantum well (MQW) structure including a well layer and a barrier layer having a higher bandgap than the well layer. For example, the first active layer 231 may have a multiple quantum well structure, such as AlGaInP, GaInP, InGaN, or GaN.

[0084] A first p-type layer 241 is formed on the first active layer 231. The first p-type layer 241 is a semiconductor layer in which positively charged holes move as charge carriers to generate current, and can be made of a GaN-based material (p-GaN) doped with p-type impurities. The GaN-based material can be GaN, AlGaN, InGaN, or AlInGaN, while Mg, Zn, or Be can be used as impurities for doping the first p-type layer 241.

[0085] A first patterned layer 291 is formed on the first p-type layer 241. The first patterned layer 291 is formed of an insulating material to protect the first p-type layer 241 and can be used to pattern pad electrodes to be formed later on the first p-type layer 241.

[0086] Reference Figure 5 , formed on it when flipped Figure 4 After the epitaxial growth of first LED elements 211, 231, and 241 and the formation of a first patterned layer 291 by a deposition process on the growth substrate 201, second LED elements 212, 232, and 242 are formed on the other side of the growth substrate 201. Since each layer constituting the second LED elements 212, 232, and 242 is formed in the same order and with the same materials as each layer constituting the first LED elements 211, 231, and 241, further description will be omitted. The second n-type layer 212 corresponds to the first n-type layer 211, the second active layer 232 corresponds to the first active layer 231, and the second p-type layer 242 corresponds to the first p-type layer 241. However, the second active layer 232 may be formed of a material used to emit light of the same color as the first active layer 231 or a material used to emit light of a different color than the first active layer 231. For example, when the first active layer 231 and the second active layer 232 are formed to emit blue light and green light respectively, the indium content included in the first active layer 231 and the second active layer 232 may be different.

[0087] Alternatively, the thickness of the growth substrate 201 can be adjusted by polishing the growth substrate 201 before growing the second LED elements 212, 232 and 242.

[0088] Furthermore, a second patterned layer 292 is formed on the second p-type layer 242 of the second LED element. Like the first patterned layer 291, the second patterned layer 292 is also formed of an insulating material to protect the second p-type layer 242 and can be used to pattern the pad electrodes to be formed later on the second p-type layer 242. For example, the first patterned layer 291 and the second patterned layer 292 can be silicon oxide layers, silicon nitride layers, or silicon oxide nitride layers.

[0089] Reference Figure 6 and Figure 7 A process for exposing the n-type and p-type layers is performed on an LED element comprising a first LED element, a second LED element having a second patterned layer 292, and providing a dual emission spectrum. First, a first contact hole h1 for exposing the second p-type layer 242 is formed by removing the second patterned layer 292 of the second LED element. Simultaneously, a second contact hole h2 for exposing the second n-type layer 212 is formed by removing not only the second patterned layer 292 of the second LED element but also the second p-type layer 242 and the second active layer 232 of the second LED element.

[0090] Next, a third contact hole h3 for exposing the first p-type layer 241 is formed by removing the first patterned layer 291 of the first LED element. Simultaneously, a fourth contact hole h4 for exposing the first n-type layer 211 is formed by removing not only the first patterned layer 291 of the first LED element but also the first p-type layer 241 and the first active layer 231 of the first LED element. In this case, to form the second contact hole h2 and the fourth contact hole h4, a method such as mesa etching, which can even etch the epitaxial layer, can be used.

[0091] Reference Figure 8 Electrodes are formed in Figure 6 and Figure 7 The first contact hole h1 to the fourth contact hole h4 are formed in the first contact hole h1 and the third contact hole h3, respectively. The second p-electrode 252 and the first p-electrode 251 are formed in the first contact hole h1 and the third contact hole h3, respectively. The second p-electrode 252 and the first p-electrode 251 are formed to contact the second p-type layer 242 and the first p-type layer 241, respectively. Furthermore, the second n-electrode 262 and the first n-electrode 261 are formed in the second contact hole h2 and the fourth contact hole h4, respectively. The second n-electrode 262 and the first n-electrode 261 are formed to contact the second n-type layer 212 and the first n-type layer 211, respectively.

[0092] Therefore, by providing a negative load to the first n-electrode 261 and a positive load to the first p-electrode 251, electrons and holes from the first n-type layer 211 and the first p-type layer 241, respectively, accumulate and recombine in the first active layer 231, causing light to be emitted from the first active layer 231. Furthermore, by providing a negative load to the second n-electrode 262 and a positive load to the second p-electrode 252, electrons and holes from the second n-type layer 212 and the second p-type layer 242, respectively, accumulate and recombine in the second active layer 232, causing light to be emitted from the second active layer 232.

[0093] Reference Figure 9 The patterned layers 291 and 292 deposited to form p-electrodes 251 and 252 and n-electrodes 261 and 262 are removed to complete the LED element 200. Patterned layers 291 and 292 are formed for the p-electrodes 251 and 252 and the n-electrodes 261 and 262, but patterned layers 291 and 292 also serve to protect the p-type layers 241 and 242 during the LED device chip fabrication process. Patterned layers 291 and 292 can be removed using a wet etching method with an etchant used for silicon oxide layers. For example, the etchant can consist of H2O, HF, and NH4F.

[0094] Figures 10 to 15 This is a cross-sectional view showing an implantation method of an LED element 200 providing a dual emission spectrum onto a panel according to an embodiment of the present disclosure.

[0095] Reference Figure 10 A driving substrate is fabricated, wherein a second pixel driving circuit 320, a second n-connection electrode 122, and a second p-connection electrode 152a are formed on the substrate 110. Although the second insulating layer 102 formed on the second n-connection electrode 122 and the second p-connection electrode 152a is shown as a single layer, the second insulating layer 102 can be formed from multiple layers. Additionally, a reflective layer 104 is formed to expose the second n-connection electrode 122 and the second p-connection electrode 152a. The reflective layer 104 is formed to overlap with the LED element 200 to prevent light absorption into the driving substrate and to improve light extraction efficiency. For example, the reflective layer 104 can be implemented as a single layer of a distributed Bragg reflector (DBR), a single layer of a nanofilm, a silicon oxide layer or a titanium dioxide layer, or a multilayer of silicon oxide and titanium dioxide layers. Embodiments of this disclosure in which the reflective layer 104 is provided can be top-emitting LED display devices. If the display device 100 according to the embodiments of the present disclosure is a bottom-emitting type, the reflective layer 104 may be omitted, or the reflective layer 104 may be disposed on the LED element 200.

[0096] Reference Figure 11On the reflective layer 104, the LED element 200 is attached to the exposed second n-connection electrode 122 and the exposed second p-connection electrode 152a. Since the second LED element in the LED element 200 is connected to the second n-connection electrode 122 and the second p-connection electrode 152a, the light emission of the second LED element can be controlled by the second pixel driving circuit 320 included in the driving substrate.

[0097] The second n-electrode 262 and the second p-electrode 252 of the second LED element are configured to be attached to the second n-connecting electrode 122 and the second p-connecting electrode 152a, respectively. A second bonding portion 412 is formed on the exposed second n-connecting electrode 122, which is to be electrically connected to the second n-electrode 262 of the second LED element, on the reflective layer 104. A first bonding portion 402 is formed on the exposed second p-connecting electrode 152a, which is to be electrically connected to the second p-electrode 252 of the second LED element, on the reflective layer 104. The first bonding portion 402 and the second bonding portion 412 may be an alloy using at least one of Sn, Pb, Ag, Cu, and Au as the metallic material.

[0098] Reference Figure 12 A third insulating layer 105, used for planarizing the display area DA of the LED display device and fixing the LED element 200, is formed on the driving substrate to which the LED element 200 is attached. For example, since the third insulating layer 105 is advantageous in cases where the visible light transmittance is high, the third insulating layer 105 can be formed from photopolymer acrylic, silicon oxide, silicon nitride, etc. When the thickness of the LED element 200 is thick, the third insulating layer 105 can be formed by a coating method, or when the thickness of the LED element 200 is thin, the third insulating layer 105 can be formed by a deposition method. The reference thickness of the LED element 200 can vary depending on the thickness of the growth substrate 201.

[0099] Reference Figure 13 and Figure 14 A first pixel driving circuit 310 is formed on the third insulating layer 105. The third insulating layer 105 is etched to correspond to the first p electrode 251 and the first n electrode 261. A first p connecting electrode 151a and a first n connecting electrode 121 are formed on the etched area and the third insulating layer 105. The first n electrode 261 of the first LED element and the first pixel driving circuit 310 are electrically connected through the first n connecting electrode 121, and the first p electrode 251 and the common power line are electrically connected through the first p connecting electrode 151a. Since the first LED element in the LED element 200 is connected to the first connecting electrodes 151a and 121, the light emission of the first LED element can be controlled by the first pixel driving circuit 310 formed on the third insulating layer 105.

[0100] Reference Figure 15 A fourth insulating layer 106 is formed on the LED element 200, the third insulating layer 105, and the first pixel driving circuit 310 to protect the LED element 200 and the first pixel driving circuit 310. Similar to the third insulating layer 105, the fourth insulating layer 106 is advantageous when it has high visible light transmittance. The fourth insulating layer 106 can be formed of photopolymer acrylic, silicon oxide, silicon nitride, etc. The fourth insulating layer 106 can be referred to as an element protective layer.

[0101] The first LED element and the second LED element of the LED element 200, which provides dual emission spectra, can emit light of different colors or the same color.

[0102] When the first LED element and the second LED element emit light of different colors, the light-emitting area can be increased by arranging two sub-pixels in a unit pixel. In this case, for example, the first LED element and the second LED element included in one of the two sub-pixels are implemented to emit blue light and green light respectively, and the first LED element and the second LED element included in the other of the two sub-pixels are both implemented to emit red light.

[0103] Brightness can be increased when the first LED element and the second LED element emit light of the same color. When a defect is generated in one of the first LED element and the second LED element and / or one of the first pixel driving circuit 310 and the second pixel driving circuit 320, the other LED element and / or the other pixel driving circuit in the first pixel driving circuit 310 and the second pixel driving circuit 320 can replace the defective one.

[0104] Figure 16 This is a cross-sectional view showing an LED display device according to an embodiment of the present disclosure.

[0105] The materials of the active layers 231 and 232 included in the LED element 200 can be changed, causing the sub-pixels to emit red, green, or blue light respectively. Alternatively, when the LED elements 200 included in the sub-pixels have the same color, the LED display device can be made to emit red, green, and blue light from the sub-pixels by providing a color conversion layer 600 on the LED element 200. The LED display device according to the embodiment of this disclosure is an embodiment that uses the color conversion layer 600 and all LED elements 200 are set to emit blue light.

[0106] In the above Figure 15In the structure, both the first active layer 231 and the second active layer 232 included in the LED element 200 are formed of a material for emitting blue light. Then, a color conversion layer 600 is formed on the fourth insulating layer 106 and in the region overlapping with the LED element 200.

[0107] The color conversion layer 600 includes a color conversion material 601. In the case of a sub-pixel emitting blue light, an insulating layer excluding the color conversion material 601 can be used. In this case, the insulating layer can be formed from a material such as photopolymer acrylic, silicon oxide, or silicon nitride. In the case of a sub-pixel emitting green or red light, the color conversion material 601 can be a fluorescent material, a nano-organic material, quantum dots, etc. In this case, the color conversion material 601 can be mixed with a material such as photopolymer acrylic, silicon oxide, or silicon nitride, and a coating, printing, or dotting method can be performed to form the color conversion layer 600. For example, when the pixel size is large, ranging from tens to hundreds of micrometers, a fluorescent material can be used, and when the pixel size is small, ranging from several to tens of micrometers, nano-organic materials and quantum dots can be used.

[0108] A separate color conversion layer 600 can be formed for each sub-pixel. By forming a black matrix 500 between adjacent color conversion layers 600, sub-pixels can be divided, and color mixing within sub-pixels can be prevented. The black matrix 500 can be formed on the same layer as the color conversion layer 600.

[0109] A fifth insulating layer 108 is formed above the entire surface of the substrate 110, on the color conversion layer 600 and the black matrix 500. The fifth insulating layer 108 protects the color conversion layer 600 and the black matrix 500. The fifth insulating layer 108 may be formed of a material such as photopolymer acrylic, silicon oxide, or silicon nitride.

[0110] Figure 17 This is a cross-sectional view showing an LED display device according to an embodiment of the present disclosure. In the LED display device according to an embodiment of the present disclosure, the case where two sub-pixels are included in a unit pixel will be described. Details may be omitted or simplified. Figure 3 Those components that overlap.

[0111] A unit pixel includes a first sub-pixel and a second sub-pixel. The first sub-pixel can emit two of the following light sources: red, green, and blue. The second sub-pixel can emit the other of these three light sources. For example, the first sub-pixel can emit both green and blue light, and the second sub-pixel can emit red light. The first sub-pixel includes a first LED element L1 and a second LED element L2, which emit green and blue light, respectively. The second sub-pixel includes a third LED element L3 and a fourth LED element L4, both of which can emit red light. When a unit pixel includes two sub-pixels, the sharpness can be improved by 50% compared to when the unit pixel includes three sub-pixels.

[0112] Luminous efficiency can be improved by implementing the least efficient color among blue, green, and red in a single sub-pixel. To achieve the target brightness of an LED display device, a structure is shown as an example where high-visibility green light is emitted from the upper active layer 231 and relatively low-visibility blue light is emitted from the lower active layer 232, but this is not a limitation. In some cases, it is possible to achieve emission of colors with insufficient brightness from the upper active layer.

[0113] The first LED element L1 and the second LED element L2 can have the same characteristics as... Figure 3 The structure is the same as that of the previously described embodiments.

[0114] The third LED element L3 includes a third n-type layer 213, a third active layer 233, a third p-type layer 243, a third p-electrode 253, and a third n-electrode 263, and the fourth LED element L4 includes a fourth n-type layer 214, a fourth active layer 234, a fourth p-type layer 244, a fourth p-electrode 254, and a fourth n-electrode 264. Both the third LED element L3 and the fourth LED element L4 have a structure that emits red light, and the third active layer 233 and the fourth active layer 234 can be formed from the same material. Additionally, indium aluminum phosphide (n-AlInP) doped with n-type impurities can be used for the third n-type layer 213 and the fourth n-type layer 214.

[0115] When forming the third LED element L3 and the fourth LED element L4 that emit red light, a growth substrate 203 made of gallium arsenide (GaAs) can be used. After forming the third LED element L3 on the front surface and the fourth LED element L4 on the rear surface of the growth substrate 203, the LED elements L3 and L4 formed on the front and rear surfaces of the growth substrate 203, respectively, are separated and transferred to a sapphire substrate. Since the sapphire substrate has a higher transmittance than the gallium arsenide substrate, the transmittance of the sub-pixel can be improved.

[0116] The first LED element L1 and the third LED element L3 are controlled by a first pixel driving circuit 310 and a third pixel driving circuit 313 formed on a third insulating layer 105, respectively, and the second LED element L2 and the fourth LED element L4 are controlled by a second pixel driving circuit 320 and a fourth pixel driving circuit 324 included in a driving substrate, respectively. Although the third LED element L3 and the fourth LED element L4 emit light of the same color, they are controlled by different pixel driving circuits. Therefore, the third LED element L3 and the fourth LED element L4 can be used as redundancies for each other, thereby preventing pixel defects.

[0117] The third insulating layer 105 is used to protect and fix the LED elements L1, L2, L3, and L4, and a black matrix 510 is formed between the third insulating layers 105 formed in two sub-pixels to prevent color mixing between the sub-pixels.

[0118] Connection electrodes 121 and 123 connecting the pixel driving circuits 310 and 313 and the LED elements L1 and L3 are formed on the third insulating layer 105 and the black matrix 510, and a fourth insulating layer 106 is formed on the third insulating layer 105 and the black matrix 510 to cover the connection electrodes 121, 123, 151a, and 153a and the pixel driving circuits 310 and 313. The fourth insulating layer 106 protects the connection electrodes 121, 123, 151a, and 153a and the pixel driving circuits 310 and 313.

[0119] Since the LED display device according to an embodiment of the present disclosure is a top-emitting type, a reflective layer 104 is provided between the driving substrate and the LED device. Alternatively, in the case of a bottom-emitting type, the reflective layer 104 may be provided on the LED device. Alternatively, the reflective layer 104 may be omitted.

[0120] Figure 18 is a cross-sectional view showing an LED display device according to an embodiment of the present disclosure. The LED display device according to an embodiment of the present disclosure describes an LED display device capable of double-sided light emission. Components overlapping those of Figure 3 may be omitted or simplified.

[0121] Since the LED display device according to an embodiment of the present disclosure shows one sub-pixel and is a double-sided light-emitting type, the insulating layers and the substrate 110 stacked on the upper and lower portions of the LED element 200 are formed of a material having a high transmittance. In addition, in order to emit light to the front and rear surfaces of the LED display device, the above-described reflective layer 104 should be omitted.

[0122] The connecting electrodes 122 and 152a on the driving substrate are attached to the LED element 200 via bonding portions 402 and 412. The LED element 200 according to an embodiment of this disclosure includes an upper LED element TL and a lower LED element BL, and the lower LED element BL is connected to the driving substrate via bonding portions 402 and 412. Next, a lower insulating layer 105a is formed on the driving substrate and around the LED element 200. The lower insulating layer 105a is formed to completely surround the lower LED element BL between the growth substrate 201 and the bonding portions 402 and 412. In this case, a portion of the growth substrate 201 can be exposed to air. The lower insulating layer 105a can be formed of photopolymer acrylic, silicon oxide, or silicon nitride, as these are advantageous when there is high visible light transmittance. When the LED element 200 is thick, the lower insulating layer 105a can be formed by a coating method, or when the LED element 200 is thin, the lower insulating layer 105a can be formed by a deposition method. The first black matrix 521 is formed on the same layer as the lower insulating layer 105a. The first black matrix 521 can be formed at the boundary between adjacent sub-pixels to prevent color mixing between sub-pixels.

[0123] To emit light onto the front and rear surfaces of the LED display device according to an embodiment of the present disclosure, a reflective layer 700 for double-sided emission is formed on the lower insulating layer 105a and the first black matrix 521. The reflective layer 700 for double-sided emission is formed in contact with the growth substrate 201 such that light emitted from the lower LED element BL is directed toward the rear of the LED display device, and light emitted from the upper LED element TL is directed toward the front of the LED display device. That is, the reflective layer 700 for double-sided emission is located on the same plane as the growth substrate 201, parallel to the substrate 110. The reflective layer 700 for double-sided emission can be implemented as a single layer of a distributed Bragg reflector (DBR), a single layer of a nanofilm, a silicon oxide layer, or a titanium dioxide layer, or a multilayer of silicon oxide and titanium dioxide layers, but is not limited thereto. Other materials with high reflectivity can be used for the reflective layer 700 for double-sided emission.

[0124] An upper insulating layer 105b and a second black matrix 522 are formed on the reflective layer 700 for bifacial emission. The upper insulating layer 105b is made of the same material as the lower insulating layer 105a and completely covers the upper LED element TL. The second black matrix 522 is formed of the same material as the first black matrix 521 at the boundaries between adjacent sub-pixels.

[0125] The upper insulating layer 105b provides contact holes for forming the first connecting electrodes 121 and 151a. The first connecting electrodes 121 and 151a are formed in the contact holes formed in the upper insulating layer 105b and on the upper insulating layer 105b and the second black matrix 522. The first n-connecting electrode 121 is connected to the first pixel driving circuit 310, and the first p-connecting electrode 151a is connected to a common power line. Additionally, a fourth insulating layer 106 is formed on the first connecting electrodes 121 and 151a and the first pixel driving circuit 310.

[0126] An LED display device according to an embodiment of this disclosure includes an upper LED element TL and a lower LED element BL, and a reflective layer 700 for bi-directional emission is formed to contact the growth substrate 201 at the boundary between the upper LED element TL and the lower LED element BL. Therefore, the LED display device can emit light in both the front and rear directions. In this case, each of the bonding portions 402 and 412 can be formed of a transparent or translucent conductive material.

[0127] Figure 19 It shows that it is equipped with Figure 2 The diagram shows a plan view of a sub-pixel SP in the pixel driving circuit, and also shows the LED element attached to the driving substrate. Figure 20 It is along Figure 19 The diagram shows a cross-sectional view taken along line A-A', and illustrates both the first pixel driving circuit and the second pixel driving circuit. The following will describe... Figure 19 and Figure 20 And can be simplified or omitted with Figure 2 Those components that overlap.

[0128] A subpixel SP includes a data line 140a and a common power line 140b arranged along the vertical axis, and a high-potential power line 150a and a scan line 150b arranged along the horizontal axis.

[0129] Regarding the LED element 200, a second pixel driving circuit is disposed between the LED element 200 and the substrate 110, and a first pixel driving circuit is disposed between the LED element 200 and the fifth insulating layer 108. The LED element 200 is disposed in an area that does not overlap with the first and second pixel driving circuits, such that light emitted from the LED element 200 is not blocked by the pixel driving circuits. The first and second pixel driving circuits are implemented with the same structure. The first pixel driving circuit includes a first transistor T11 and a second transistor T21, and the second pixel driving circuit includes a first transistor T12 and a second transistor T22. A first insulating layer 101 for protecting the second pixel driving circuit covers the second pixel driving circuit and is shown as a single layer. However, it is not limited to this, and the first insulating layer 101 may be formed of multiple layers. Similarly, a fourth insulating layer 106 for protecting the first pixel driving circuit covers the first pixel driving circuit and is shown as a single layer. However, it is not limited to this, and the fourth insulating layer 106 may be formed of multiple layers.

[0130] The first transistors T11 and T12, included in the first pixel driving circuit and the second pixel driving circuit, respectively include gate electrodes 322G and 312G, semiconductor layers 322A and 312A, source electrodes 322S and 312S, and drain electrodes 322D and 312D. The second transistors T22 and T21 respectively include gate electrodes 321G and 311G, semiconductor layers 321A and 311A, source electrodes 321S and 311S, and drain electrodes 321D and 311D. In the first transistors T11 and T12 and the second transistors T22 and T21, gate insulating layers 322GI, 321GI, 312GI, and 311GI are located between the gate electrodes 322G, 321G, 312G, and 311G and the semiconductor layers 322A, 312A, 321A, and 311A. The gate insulating layers 322GI and 321GI included in the second pixel driving circuit can be formed as a single layer on the substrate 110, and the gate insulating layers 312GI and 311GI included in the first pixel driving circuit can be formed as a single layer on the third insulating layer 105.

[0131] Gate electrodes 322G, 312G, 321G, and 311G are formed on the same layer as scan line 150b on substrate 110 and are formed of the same material as scan line 150b on substrate 110. Gate electrodes 322G, 312G, 321G, and 311G may comprise semiconductors such as silicon (Si), conductive metals such as molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu), or alloys thereof, and may have multiple layers thereof.

[0132] The gate insulating layers 322GI, 321GI, 312GI and 311GI can be formed by multiple layers or a single layer made of inorganic materials, and can be made of silicon oxide (SiOx), silicon nitride (SiNx) and the like.

[0133] Semiconductor layers 322A, 321A, 312A, and 311A ​​are disposed on gate insulating layers 322GI, 321GI, 312GI, and 311GI in a predetermined pattern shape to overlap with gate electrodes 322G, 312G, 321G, and 311G. Semiconductor layers 322A, 321A, 312A, and 311A ​​may be made of a semiconductor material selected from amorphous silicon, polycrystalline silicon, oxide, and organic materials, but are not limited thereto.

[0134] The source electrodes 322S, 321S, 312S and 311S are configured to overlap one side of the semiconductor layers 322A, 321A, 312A and 311A, and are formed on the same layer as the data line 140a and the high-potential power line 150a and are made of the same material as the data line 140a and the high-potential power line 150a.

[0135] Drain electrodes 322D, 321D, 312D, and 311D are configured to overlap with the other side of semiconductor layers 322A, 321A, 312A, and 311A, and spaced apart from source electrodes 322S, 321S, 312S, and 311S. Drain electrodes 322D, 321D, 312D, and 311D are formed on the same layer as source electrodes 322S, 321S, 312S, and 311S and are made of the same material as source electrodes 322S, 321S, 312S, and 311S.

[0136] The source electrodes 322S, 321S, 312S and 311S and the drain electrodes 322D, 321D, 312D and 311D may comprise a semiconductor such as silicon (Si), a conductive metal such as molybdenum (Mo) or aluminum (Al), and may be any of chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu), or an alloy thereof, and may have multiple layers thereof.

[0137] The second p-connecting electrode 152a, branching from the high-potential power line 150a, is connected to the second p-type layer 242 of the LED element 200 and to the second p-electrode 252, which is in contact with the second p-type layer 242. The second p-connecting electrode 152a and the second p-electrode 252 are connected through a first bonding portion 402.

[0138] The second n-connection electrode 122, connected to the second transistor T22, is connected to the second n-type layer 212 of the LED element 200 and to the second n-electrode 262, which is in contact with the second n-type layer 212. The second n-connection electrode 122 and the second n-electrode 262 are connected via the second bonding portion 412. Additionally, the second transistor T22 is connected to the common power line 140b via the contact electrode 142b.

[0139] The gate electrode 321G of the second transistor T22 is connected to one electrode 130a of the capacitor, and the other electrode 130a of the capacitor is connected to and in contact with the drain electrode 322D of the first transistor T12. The other electrode 130b of the capacitor overlaps with one electrode 130a and is connected to the common power line 140b.

[0140] Scan line 150b is connected to the gate electrode 322G of the first transistor T12, and the source electrode 322S of the first transistor T12 is connected to the data line 140a through contact electrode 142a.

[0141] The connection between the LED element 200 and the first transistor T12 and the second transistor T22 formed on the substrate 110 can be applied to the first transistor T11 and the second transistor T21 formed on the third insulating layer 105.

[0142] In an LED display device according to an embodiment of the present disclosure, the LED display device includes: a second pixel driving circuit on a substrate; LED elements attached to a region not overlapping with the second pixel driving circuit and including a first LED element, a second LED element, and a growth substrate; an element fixing layer surrounding the LED elements; the first pixel driving circuit on the element fixing layer; and an element protective layer on the first pixel driving circuit, wherein the first LED element is controlled by the first pixel driving circuit, and the second LED element is controlled by the second pixel driving circuit. Therefore, the LED display device provides a dual emission spectrum, enabling high brightness and high definition, and preventing pixel defects.

[0143] According to another aspect of this disclosure, the second LED element can be electrically connected to the second pixel driving circuit via a bonding portion and a connecting electrode.

[0144] According to another aspect of this disclosure, the LED display device may further include a reflective layer between LED elements and a substrate, wherein the reflective layer may overlap with the LED elements. The reflective layer may contact the growth substrate. A second LED element may emit light toward the substrate, and a first LED element may emit light toward the element protective layer.

[0145] According to another aspect of this disclosure, the LED display device may further include a color conversion layer on a protective layer and a black matrix disposed on the same layer as the color conversion layer.

[0146] According to another aspect of this disclosure, the first LED element and the second LED element can emit light of different colors.

[0147] According to another aspect of this disclosure, the first pixel driving circuit and the second pixel driving circuit may have the same components, and the connection relationships between the same components may be the same.

[0148] According to another aspect of this disclosure, the LED display device may also include a black matrix disposed on the same layer as the element fixing layer.

[0149] In an LED display device according to an embodiment of the present disclosure, the LED display device includes: a substrate divided into a display area and a non-display area, wherein a unit pixel is disposed in the display area; a second pixel driving circuit on the substrate; a second connection electrode electrically connected to the second pixel driving circuit; a second LED element contacting the second connection electrode; a first LED element disposed on the second LED element; a first pixel driving circuit disposed on the first LED element; and a first connection electrode electrically connecting the first LED element and the first pixel driving circuit. Therefore, the LED display device provides a dual emission spectrum, achieving high brightness and high definition, and preventing pixel defects.

[0150] According to another aspect of this disclosure, a unit pixel may include a first sub-pixel and a second sub-pixel, each of which may include a first LED element and a second LED element. The first sub-pixel may emit green and blue light, and the second sub-pixel may emit red light. The LED display device may be top-emitting, with the first LED element included in the first sub-pixel emitting green light and the second LED element included in the first sub-pixel emitting blue light. Furthermore, the structure of each of the first and second LED elements included in the first sub-pixel may differ from the structure of each of the first and second LED elements included in the second sub-pixel.

[0151] According to another aspect of this disclosure, the first LED element and the second LED element may be attached to the same growth substrate.

[0152] According to another aspect of this disclosure, the LED display device may further include a junction portion connecting the second LED element and the second connecting electrode.

[0153] According to another aspect of this disclosure, a unit pixel may include a plurality of sub-pixels, a black matrix may be provided between adjacent sub-pixels in the plurality of sub-pixels, and the black matrix may be formed on the same layer as the first LED element and the second LED element.

[0154] Although embodiments of the invention have been described in more detail with reference to the accompanying drawings, the invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the invention. Therefore, the embodiments disclosed herein are not intended to limit the spirit of the invention, but rather to explain it, and the scope of the spirit of the invention is not limited by these embodiments. Thus, it should be understood that the above embodiments are illustrative in all respects and not restrictive. The scope of protection of this invention should be interpreted by the claims, and all technical concepts within their equivalents should be interpreted as being included within the scope of this invention.

Claims

1. An LED display device, comprising: The second pixel driving circuit on the substrate; The LED element is attached to an area that does not overlap with the second pixel driving circuit and includes a first LED element, a second LED element, and a growth substrate; A component fixing layer surrounding the LED element; The first pixel driving circuit on the component fixing layer; as well as Component protection layer on the first pixel driving circuit The first LED element is controlled by the first pixel driving circuit, and the second LED element is controlled by the second pixel driving circuit.

2. The LED display device according to claim 1, wherein, The second LED element is electrically connected to the second pixel driving circuit via a bonding portion and a connecting electrode.

3. The LED display device according to claim 1, further comprising: The reflective layer between the LED element and the substrate, The reflective layer overlaps with the LED element.

4. The LED display device according to claim 1, further comprising: A reflective layer located on the same plane as the growth substrate.

5. The LED display device according to claim 4, wherein, The second LED element emits light toward the substrate, and the first LED element emits light toward the element protective layer.

6. The LED display device according to claim 1, further comprising: A color conversion layer located on the protective layer of the component.

7. The LED display device according to claim 1, wherein, The first LED element and the second LED element emit light of different colors.

8. The LED display device according to claim 1, wherein, The first pixel driving circuit and the second pixel driving circuit have the same components, and the connection relationship between the same components is the same.

9. The LED display device according to claim 1, further comprising: A black matrix is ​​set on the same layer as the element fixing layer.

10. An LED display device, comprising: A substrate divided into a display area and a non-display area, wherein a unit pixel is provided in the display area; The second pixel driving circuit on the substrate; The second connection electrode is electrically connected to the second pixel driving circuit. The second LED element that contacts the second connecting electrode; A first LED element disposed on the second LED element; A first pixel driving circuit disposed on the first LED element; as well as The first connection electrode electrically connects the first LED element and the first pixel driving circuit. The first LED element and the second LED element are disposed between the first pixel driving circuit and the second pixel driving circuit.

11. The LED display device according to claim 10, wherein, The unit pixel includes a first sub-pixel and a second sub-pixel. Each of the first sub-pixel and the second sub-pixel includes the first LED element and the second LED element, and The first sub-pixel emits green and blue light, while the second sub-pixel emits red light.

12. The LED display device according to claim 11, wherein, The LED display device is a top-emitting type. The first LED element included in the first sub-pixel emits green light, and the second LED element included in the first sub-pixel emits blue light.

13. The LED display device according to claim 11, wherein, The structure of each of the first LED element and the second LED element included in the first sub-pixel is different from the structure of each of the first LED element and the second LED element included in the second sub-pixel.

14. The LED display device according to claim 10, wherein, The first LED element and the second LED element are attached to the same growth substrate.

15. The LED display device according to claim 10, further comprising: The junction portion connecting the second LED element and the second connecting electrode.

16. The LED display device according to claim 10, wherein, The unit pixel includes multiple sub-pixels. A black matrix is ​​provided between adjacent sub-pixels of the plurality of sub-pixels, and the black matrix is ​​formed on the same layer as the first LED element and the second LED element.

17. An LED display device, comprising: A substrate divided into a display area and a non-display area, wherein a unit pixel is provided in the display area; The second pixel driving circuit on the substrate; The second connection electrode is electrically connected to the second pixel driving circuit. The second LED element that contacts the second connecting electrode; A first LED element disposed on the second LED element; A first pixel driving circuit disposed on the first LED element; as well as The first connection electrode electrically connects the first LED element and the first pixel driving circuit. The unit pixel includes multiple sub-pixels. A black matrix is ​​provided between adjacent sub-pixels of the plurality of sub-pixels, and the black matrix is ​​formed on the same layer as the first LED element and the second LED element.

Images