Display device

Abstract

A display device is provided, comprising: a flexible substrate; a plurality of light emitting elements spaced apart from each other on the substrate; and a light blocking film filling spaces between the light emitting elements and covering a portion of each light emitting element to define light extraction surfaces, respectively, wherein the distances between the light extraction surfaces are the same.

Description

Technical Field

[0001] The present invention relates to a display device, and more particularly to a flexible display device. Background Art

[0002] Generally, a display device includes a display panel that displays an image using light and a backlight unit that provides light to the display panel. The display panel includes a plurality of pixel units including a switching element, a pixel electrode, a common electrode, and a color layer. A liquid crystal display panel is generally used as a display panel. The light provided by the backlight unit passes through the liquid crystal and the color layer and enables the display device to display a color image by variable color mixing of the light. At this time, the color layer for displaying the color image includes, for example, a red filter, a green filter, and a blue filter. Moreover, a plurality of colors are displayed by mixing the light passing through the filters. That is, in order to realize a plurality of colors of light for displaying an image, a filter is required.

[0003] Furthermore, since liquid crystals are used, polarization is required, and accordingly, a polarizing plate is used and various optical films are required, which makes the display device thicker and heavier. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a display device including a plurality of light emitting diodes, which can omit components such as liquid crystal, a backlight unit, a polarizer, and a color filter.

[0005] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art through the following description.

[0006] In order to solve the technical problem to be solved, a display device according to an embodiment of the present invention includes: a flexible substrate; a plurality of light-emitting elements separated from each other on the substrate; and a light-blocking film filling between the light-emitting elements and covering a portion of each of the light-emitting elements, while respectively defining light extraction surfaces, wherein the distances between the light extraction surfaces are the same as each other.

[0007] According to an embodiment, the light emitting elements may be spaced apart by a first distance along a first direction and may be spaced apart by a second distance along a second direction perpendicular to the first direction, and the first distance may be greater than or equal to the second distance.

[0008] According to an embodiment, the substrate may be curled along the first direction.

[0009] According to an embodiment, in a case where the first distance is greater than the second distance, a region of the light-blocking film covering the light-emitting element in the second direction may be larger than a region of the light-blocking film covering the light-emitting element in the first direction.

[0010] According to an embodiment, the display device may further include: a common circuit electrically connected to the light emitting elements, wherein the common circuit may have a grid structure on the substrate.

[0011] According to an embodiment, the display device may further include: a protective layer covering the light emitting element on the substrate and including a substance that transmits visible light.

[0012] According to an embodiment, hardness of the substrate may be smaller than hardness of each of the light emitting elements.

[0013] According to an embodiment, each of the light emitting elements may include a first light emitting portion, a second light emitting portion, and a third light emitting portion that are horizontally spaced apart from each other on the substrate.

[0014] According to an embodiment, each of the light emitting elements may include a first light emitting portion, a second light emitting portion, and a third light emitting portion vertically stacked on the substrate.

[0015] According to an embodiment, the third light emitting portion may have a smaller width than the second light emitting portion, and the second light emitting portion may have a smaller width than the first light emitting portion.

[0016] According to an embodiment, each of the light emitting elements may have a width that gradually narrows upward from one side of the substrate.

[0017] Details of other embodiments are included in the detailed description and drawings.

[0018] The display device according to the embodiment of the invention can extract light with high efficiency using less power by arranging a plurality of light emitting elements including a plurality of light emitting portions on a flexible substrate, and can be applied to various electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1a to Figure 1c is a plan view for explaining a display device according to an embodiment of the present invention.

[0020] Figure 2a FIG. 1 is a plan view for explaining a light emitting element according to an embodiment of the present invention.

[0021] Figure 2b Yes Figure 2a A cross-sectional view of the light-emitting element taken along line AA'.

[0022] Figure 2c Yes Figure 2a A cross-sectional view of the light-emitting element taken along line BB'.

[0023] Figure 3a as well as Figure 3bis a cross-sectional view for explaining a light emitting element according to another embodiment of the present invention.

[0024] Figure 4a as well as Figure 4b is a cross-sectional view for explaining a light emitting element according to another embodiment of the present invention.

[0025] Figure 5a is a plan view for explaining a light emitting element according to still another embodiment of the present invention.

[0026] Figure 5b Yes Figure 5a A cross-sectional view of the light-emitting element taken along line AA'.

[0027] Figure 6a It is a plan view for explaining a light emitting element according to still another embodiment of the present invention.

[0028] Figure 6b Yes Figure 6a A cross-sectional view of the light-emitting element taken along lines AA' and BB'.

[0029] Figures 7a to 12a It is a plan view for explaining a method for manufacturing a light emitting element according to an embodiment of the present invention.

[0030] Figures 7b to 12b Yes Figures 7a to 12a A cross-sectional view of the light-emitting element taken along line AA'.

[0031] Figures 7c to 12c Yes Figures 7a to 12a A cross-sectional view of the light-emitting element taken along line BB'.

[0032] Fig.13a as well as Fig.13b It is a cross-sectional view for explaining a method of mounting a light emitting element manufactured according to an embodiment of the present invention on a mounting substrate.

[0033] Fig.14 as well as Fig.15 An electronic device to which a display device according to an embodiment of the present invention is applied is illustrated. DETAILED DESCRIPTION

[0034] In order to fully understand the configuration and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be implemented in various forms and can be variously modified.

[0035] And, the terms used in the embodiments of the present invention may be construed as meanings generally known to a person having ordinary knowledge in the corresponding technical field unless otherwise defined.

[0036] Hereinafter, a display device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0037] Figure 1a to Figure 1c is a plan view for explaining a display device according to an embodiment of the present invention. Figure 2a is a plan view for explaining a light emitting element according to an embodiment of the present invention, Figure 2b Yes Figure 2a A cross-sectional view of the light emitting element taken along A-A', Figure 2c Yes Figure 2a A cross-sectional view of the light-emitting element taken along BB'. Figure 3a as well as Figure 3b is a cross-sectional view for explaining a light emitting element according to another embodiment of the present invention. Figure 4a as well as Figure 4b is a cross-sectional view for explaining a light emitting element according to still another embodiment of the present invention.

[0038] Reference Figure 1a , Figure 1b , Figure 1c , Figure 2a , Figure 2b , Figure 2c , Figure 3a , Figure 3b , Figure 4a as well as Figure 4b The display device may include a substrate SUB and a plurality of light emitting elements LED arranged on the substrate SUB. Figure 1a as well as Figure 1b is a plan view of a first surface of each of a plurality of light emitting elements LED in a display device, Figure 1c 1 is a plan view viewed from another surface facing the second surface of each light emitting element LED in the display device. The second surface of each light emitting element LED may be a surface facing the substrate SUB.

[0039] The substrate SUB may include a plastic substrate SUB having flexibility and visible light transmittance characteristics. The plastic substrate SUB may include at least one of a polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a polyacrylonitrile resin, a polyimide resin, a polymethyl methacrylate resin, a polycarbonate (PC) resin, a polyethersulfone (PES) resin, a polyamide resin, a cycloolefin resin, a polystyrene resin, a polyamide imide resin, a polyether imide resin, a polymethyl siloxane (PDMS) resin, a polyetheretherketone (PEEK) resin, and a polyvinylchloride resin. However, the plastic substrate (SUB) is not limited to the above-mentioned substances.

[0040] According to one embodiment, the substrate SUB may be rolled along the first direction DR1.

[0041] On the first surface of the substrate SUB, the plurality of light emitting elements LED may be arranged at a first distance DT1 along a first direction DR1, and may be arranged at a second distance DT2 along a second direction DR2 perpendicular to the first direction DR1. According to one embodiment, the first distance DT1 may be greater than the second distance DT2. In this case, the light emitting elements LED are more spaced apart along the first direction DR1, so that the substrate SUB may be easily curled along the first direction DR1. According to another embodiment, the first distance DT1 may be substantially the same as the second distance DT2.

[0042] The first distance DT1 and the second distance DT2 between the light emitting elements LED may be 8 to 15 times of the critical dimension CD of each light emitting element LED. The critical dimension CD of the light emitting element LED may be 50 to 80 μm.

[0043] According to an embodiment, the substrate SUB may have a first hardness, and each light emitting element LED may have a second hardness. The first hardness may be smaller than the second hardness. Since the light emitting elements LED having a very small critical size of 50 to 80 μm are sufficiently separated by the first distance DT1 and the second distance DT2, even if the light emitting elements LED are made of a harder material than the substrate SUB, when the substrate SUB is curled and bent, the light emitting elements LED can be prevented from being damaged, etc.

[0044] according to Figure 1a In one embodiment shown, the display device may further include a protective layer PRT filling between the light-emitting element LEDs and covering the light-emitting element LEDs on the substrate SUB. The protective layer PRT may include a material that allows visible light to pass through and is soft. The protective layer PRT may include a silicone resin, specifically, a silicone resin such as a siloxane resin or an epoxy resin. For example, the protective layer PRT may include PDMS. In this case, the light-emitting area LEA of each light-emitting element LED may be the same as the light extraction area LEX. The light-emitting area LEA indicates the area where the light-emitting element LED emits light, and the light extraction area LEX indicates the area where the light emitted from the light-emitting area LEA is extracted to the outside. The light-emitting area LEA and the light extraction area LEX are based on one side of the substrate. As an example, when the first distance DT1 and the second distance DT2 between the light-emitting element LEDs are the same, the distances between the light extraction areas LEX may be the same. As another example, when the first distance DT1 between the light-emitting element LEDs is greater than the second distance DT2, the distances between the light extraction areas LEX may be different from each other according to the distances between the light-emitting element LEDs.

[0045] according to Figure 1b In another embodiment shown, the display device may further include a light blocking film LS filling between the light emitting elements LED and covering a portion of each light emitting element LED on the substrate SUB. The light blocking film LS may include a substance having insulating properties and absorbing or blocking light. For example, the light blocking film LS may include a photoresist or a black matrix. The portion where the light blocking film LS is not formed may be protected by a protective layer PRT. In this case, due to the light blocking film LS, the light extraction area of ​​each light emitting element may be smaller than the light emitting area. Thus, the contrast of the light emitted from each light emitting element LED may be increased.

[0046] Continue to refer to Figure 1bIn the light emitting element LED, when the first distance DT1 is greater than the second distance DT2, the area of ​​the light blocking film LS covering the light emitting element LED along the second direction DR2 can be larger than the area of ​​the light emitting element LED covered along the first direction DR1. As an example, the light blocking film LS exposes the light emitting element along the first direction DR1, but covers a portion of the light emitting element LED along the second direction DR2 (i.e., the difference between the first distance DT1 and the second distance DT2), so that the light extraction areas LEX can be spaced at equal intervals according to the first distance DT1. In this way, if the light extraction areas LEX are spaced at equal intervals, the display device including the light emitting element LED can emit uniform light as a whole.

[0047] according to Figure 2a , Figure 2b , Figure 2c , Figure 3a as well as Figure 3b In one embodiment shown, each light emitting element LED may include a first light emitting portion LE1, a second light emitting portion LE2, and a third light emitting portion LE3 stacked vertically. According to one embodiment, the first light emitting portion LE1 may emit light with the shortest wavelength, the second light emitting portion LE2 may emit light with a wavelength longer than the wavelength of the light emitted from the first light emitting portion LE1 and shorter than the wavelength of the light emitted from the third light emitting portion LE3, and the third light emitting portion LE3 may emit light with the longest wavelength. As an example, the first light emitting portion LE1 may emit blue light, the second light emitting portion LE2 may emit green light, and the third light emitting portion LE3 may emit red light. However, the colors of the light emitted by the first to third light emitting portions LE1, LE2, and LE3 are not limited thereto and may be changed to multiple colors. For example, the first to third light emitting portions LE1, LE2, and LE3 may emit red light, blue light, and green light in sequence. Alternatively, the first to third light emitting portions LE1, LE2, and LE3 may emit different lights from each other, but a part of them may emit the same light.

[0048] The first light emitting portion LE1 may include a first n-type semiconductor layer 102, a first active layer 104, a first p-type semiconductor layer 106, and a first ohmic layer 108. The second light emitting portion LE2 may include a second n-type semiconductor layer 202, a second active layer 204, a second p-type semiconductor layer 206, and a second ohmic layer 208. The third light emitting portion LE3 may include a third n-type semiconductor layer 302, a third active layer 304, a third p-type semiconductor layer 306, and a third ohmic layer 308.

[0049] The first n-type semiconductor layer 102, the second n-type semiconductor layer 202, and the third n-type semiconductor layer 302 may be GaN-based semiconductor layers doped with Si, respectively. The first p-type semiconductor layer 106, the second p-type semiconductor layer 206, and the third p-type semiconductor layer 306 may be GaN-based semiconductor layers doped with Mg, respectively. The first active layer 104, the second active layer 204, and the third active layer may include a multi-quantum well structure (MQW: Multi Quantum Well), and their composition ratios may be determined to emit light of a desired peak wavelength. The first ohmic layer 108, the second ohmic layer 208 and the third ohmic layer 308 can be made of indium tin oxide (ITO), zinc-doped indium tin oxide (ZITO), indium zinc oxide (ZIO), gallium indium oxide (GIO), zinc tin oxide (ZTO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), In4Sn3O 12 and Zn (1-x) Mg xAt least one transparent oxide layer (TCO: Transparent Conductive Oxide) in O (zinc magnesium oxide, 0≤x≤1). The first n-type semiconductor layer 102, the first active layer 104, the first p-type semiconductor layer 106 and the first ohmic layer 108 in the first light-emitting portion LE1 can be stacked in sequence, the second ohmic layer 208, the second p-type semiconductor layer 206, the second active layer 204 and the second n-type semiconductor layer 202 in the second light-emitting portion LE2 can be stacked in sequence, and the third ohmic layer 308, the third p-type semiconductor layer 306, the third active layer 304 and the third n-type semiconductor layer 302 in the third light-emitting portion LE3 can be stacked in sequence. According to one embodiment, the second light-emitting portion LE2 can have a smaller planar area than the first light-emitting portion LE1, and the third light-emitting portion LE3 can have a smaller planar area than the second light-emitting portion LE2. As an example, the first light emitting portion LE1 may have a structure in which the first active layer 104, the first p-type semiconductor layer 106, and the first ohmic layer 108 are etched to expose a portion of the first n-type semiconductor layer 102. The second light emitting portion LE2 may have a smaller planar area than the first light emitting portion LE1 to expose the first ohmic layer 108 of the first light emitting portion LE1, and a structure in which the second p-type semiconductor layer 206, the second active layer 204, and the second n-type semiconductor layer 202 are etched to expose a portion of the second ohmic layer 208. The third light emitting portion LE3 may have a smaller planar area than the second light emitting portion LE2 to expose the second n-type semiconductor layer 202, and a structure in which the third p-type semiconductor layer 306, the third active layer 304, and the third n-type semiconductor layer 302 are etched to expose a portion of the third ohmic layer 308.

[0050] The light emitting element LED may further include: a first pad PD1 electrically connected to the first n-type semiconductor layer 102; a second pad PD2 electrically connected to the second n-type semiconductor layer 202; a third pad PD3 electrically connected to the third n-type semiconductor layer 302; and a common pad CPD electrically connected to the first ohmic layer 108, the second ohmic layer 208, and the third ohmic layer 308. Each of the first pad PD1, the second pad PD2, the third pad PD3, and the common pad CPD may include at least one selected from the group consisting of Au, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Hf, Cr, Ti, and Cu. In addition, alloys of the above metals may be included.

[0051] In this embodiment, an example is exemplified in which the first ohmic layer 108 , the second ohmic layer 208 , and the third ohmic layer 308 are electrically connected to the common pad CPD. However, the first n-type semiconductor layer 102 , the second n-type semiconductor layer 202 , and the third n-type semiconductor layer 302 may also be electrically connected to the common pad CPD.

[0052] The light emitting element LED may further include a first bonding portion AD1 between the first light emitting portion LE1 and the second light emitting portion LE2 for bonding the first light emitting portion LE1 and the second light emitting portion LE2, and a second bonding portion AD2 between the second light emitting portion LE2 and the third light emitting portion LE3 for bonding the second light emitting portion LE2 and the third light emitting portion LE3. The first bonding portion AD1 and the second bonding portion AD2 may each include a material having insulating properties and transmitting visible light and having bonding properties. The first bonding portion AD1 and the second bonding portion AD2 may each include glass, polymer, resist, or polyimide, etc. For example, each of the first bonding portion AD1 and the second bonding portion AD2 may include spin on glass (SOG: Spin On Glass), benzocyclobutene (BCB: benzocyclobutene), hydrogen silsesquioxane (HSQ: hydrogen silsesquioxane), or SU-8 photoresist.

[0053] Optionally, the light emitting element LED may further include a first color filter CF1 arranged between the first light emitting portion LE1 and the second light emitting portion LE2, and a second color filter CF2 arranged between the second light emitting portion LE2 and the third light emitting portion LE3. The first color filter CF1 may reflect light emitted from the first light emitting portion LE1 so that the light emitted from the first light emitting portion LE1 will not affect the second light emitting portion LE2 and the third light emitting portion LE3, and may allow light emitted from the second light emitting portion LE2 and the third light emitting portion LE3 to pass through. The second color filter CF2 may reflect light emitted from the first light emitting portion LE1 and the second light emitting portion LE2 so that the light emitted from the first light emitting portion LE1 and the second light emitting portion LE2 will not affect the third light emitting portion LE3, and may allow light emitted from the third light emitting portion LE3 to pass through. The first color filter CF1 and the second color filter CF2 may respectively include a distributed Bragg reflector (DBR: Distributed Bragg Reflector) having a structure in which TiO2 and SiO2 are alternately stacked. For example, the order and number of times that TiO 2 and SiO 2 of the second color filter CF2 are alternating may be different from the order and number of times that TiO 2 and SiO 2 of the first color filter CF1 are alternating.

[0054] The light emitting element LED may further include: a first contact pattern CT1 electrically contacting the first n-type semiconductor layer 102; a first extension pattern EL1 electrically contacting the first contact pattern CT1 and extending to the flat upper portion of the first n-type semiconductor layer 102; and a first through pattern VA1 electrically connecting the first extension pattern EL1 and the first pad PD1. The light emitting element LED may further include: a second contact pattern CT2 electrically contacting the second n-type semiconductor layer 202; a second extension pattern EL2 electrically contacting the second contact pattern CT2 and extending to the flat upper portion of the first n-type semiconductor layer 102; and a second through pattern VA2 electrically connecting the second extension pattern EL2 and the second pad PD2. The light emitting element LED may further include: a third contact pattern CT3 electrically contacting the third n-type semiconductor layer 302; a third extension pattern EL3 electrically contacting the third contact pattern CT3 and extending to the flat upper portion of the first n-type semiconductor layer 102; and a third through pattern VA3 electrically connecting the third extension pattern EL3 and the third pad PD3. It may also include: a first common contact pattern CCT1, electrically contacting the first ohmic layer 108 and the second ohmic layer 208; a second common contact pattern CCT2, electrically connected to the third ohmic layer 308; a common extension pattern CEL, electrically contacting the first common contact pattern CCT1 and the second common contact pattern CCT2, and extending to the flat upper portion of the first n-type semiconductor layer 102; and a common through pattern CVA, electrically connecting the common extension pattern CEL and the common pad CPD. In this case, the first pad PD1, the second pad PD2, the third pad PD3 and the common pad CPD may all be arranged between the third light emitting portion LE3 and the substrate SUB.

[0055] Reference Figure 2a , Figure 2b , Figure 2c , Figure 3a as well as Figure 3b, the first through pattern VA1, the second through pattern VA2, the third through pattern VA3 and the common through pattern CVA are arranged on the first extension pattern EL1, the second extension pattern EL2, the third extension pattern EL3 and the common extension pattern CEL extending to the flat first n-type semiconductor layer 102, so as to have the same height as each other. Therefore, the required current can be more stably provided to each of the first n-type semiconductor layer 102, the second n-type semiconductor layer 202, the third n-type semiconductor layer 302 and the first ohmic layer 108, the second ohmic layer 208 and the third ohmic layer 308 through each of the first through pattern VA1, the second through pattern VA2, the third through pattern VA3 and the common through pattern CVA. According to one embodiment, the first pad PD1, the second pad PD2, the third pad PD3 and the common pad CPD can extend to the passivation film PVT covering the light emitting element LED, respectively. Therefore, when the size of the light emitting element LED is small and the positions or sizes of the first pad PD1, the second pad PD2, the third pad PD3 and the common pad CPD are not suitable for the substrate SUB for mounting, the first pad PD1, the second pad PD2, the third pad PD3 and the common pad CPD can be extended on the passivation film PVT so that they can be easily mounted on the target substrate SUB.

[0056] Reference Figure 1a , Figure 1b , Figure 2a , Figure 2b , Figure 2c , Figure 3a as well as Figure 3b Each third light emitting portion LE3 may be arranged to face the substrate SUB, and one side of each first light emitting portion LE1 may include a light emitting area LEA. Figure 2a , Figure 2b as well as Figure 2c In the embodiment shown, the light emitting elements LED can be insulated from each other by the protective layer PRT. Figure 3a as well as Figure 3b In another embodiment shown, the display device may further include a light blocking film LS that fills between the light emitting elements LED and covers a portion of one side of the first light emitting portion LE1 of each light emitting element LED. The width of the first n-type semiconductor layer 102 of the first light emitting portion LE1 may be the light emitting area LEA. The light blocking film may cover a portion of the light emitting area LEA and may define a light extraction area LEX. In this case, the light extraction area LEX may be smaller than the light emitting area LEA. The light blocking film LS covers a portion of the first side of each light emitting element LED and reduces the area of ​​the side from which light is extracted, thereby increasing the brightness ratio of the light emitted from each light emitting element LED.

[0057] according to Figure 4a as well as Figure 4b In another embodiment shown, the light emitting element LED may further include a first contact pattern CT1 electrically contacting the first n-type semiconductor layer 102 and a first extension pattern EL1 electrically contacting the first contact pattern CT1 and extending from the third light emitting portion LE3 to the first light emitting portion LE1. A second contact pattern CT2 electrically contacting the second n-type semiconductor layer 202 and a second extension pattern EL2 electrically contacting the second contact pattern CT2 and extending from the third light emitting portion LE3 to the first light emitting portion LE1 may further be included. A third contact pattern CT3 electrically contacting the third n-type semiconductor layer 302 and a third extension pattern EL3 electrically contacting the third contact pattern CT3 and extending from the third light emitting portion LE3 of the light emitting element LED to the first light emitting portion LE1 may further be included. It may further include: a first common contact pattern CCT1 electrically contacting the first ohmic layer 108 and the second ohmic layer 208; a second common contact pattern CCT2 electrically contacting the third ohmic layer 308; and a common extension pattern CEL electrically contacting the first common contact pattern CCT1 and the second common contact pattern CCT2 and extending from the third light emitting portion LE3 of the light emitting element LED to the first light emitting portion LE1. In this case, the first light emitting portion LE1 faces the substrate SUB, and the other surface of the substrate SUB facing the first light emitting portion LE1 may include a light extraction surface.

[0058] Figure 4a as well as Figure 4b Each of the first extended pattern EL1, the second extended pattern EL2, the third extended pattern EL3 and the common extended pattern CEL shown may include at least one selected from the group consisting of Au, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Hf, Cr, Ti and CU. In addition, alloys of the above metals may be included. The first extended pattern EL1, the second extended pattern EL2, the third extended pattern EL3 and the common extended pattern CEL containing the metal extend from the third light-emitting portion LE3 of the light-emitting element LED to the first light-emitting portion LE1 and are arranged on the side of the light-emitting element LED, thereby functioning as a light-blocking film. In addition, the width may gradually decrease from the first light-emitting portion LE1 to the third light-emitting portion LE3. Therefore, the substrate SUB on which a plurality of light-emitting elements LED are arranged may be easily rolled.

[0059] The display device may further include a first substrate pad SPD1, a second substrate pad SPD2, a third substrate pad SPD3, and a common substrate pad SCPD, which are electrically connected to the first pad PD1, the second pad PD2, the third pad PD3, and the common pad CPD, respectively. The first substrate pad SPD1, the second substrate pad SPD2, the third substrate pad SPD3, and the common substrate pad SCPD are respectively arranged at positions corresponding to the first pad PD1, the second pad PD2, the third pad PD3, and the common pad CPD, and may be electrically bonded by conductive materials such as solder balls SD, respectively.

[0060] The display device may further include a common circuit CC electrically connected to the common substrate pad SCPD on one side of the substrate SUB facing the light emitting element LED (see Figure 1c ). The common circuit CC may have a mesh structure that electrically connects a plurality of common substrate pads SCPD. The common substrate pads SCPD may be electrically connected to each other via the common circuit CC. The common circuit CC may include a first extension portion ET1 and a second extension portion ET2 that are electrically connected to each common substrate pad SCPD. In this way, the common circuit CC that applies a predetermined voltage to the common substrate pad SCPD electrically connects the common pads CPD of the plurality of light-emitting elements LED in a mesh structure, so that a predetermined voltage can be applied to the common pad CPD even if a portion of the common circuit CC or the common substrate pad SCPD is damaged during the period when the substrate is curled.

[0061] The light emitting element of the display device can be modified in various ways. Hereinafter, the light emitting element according to various embodiments will be described in detail.

[0062] Figure 5a is a plan view for explaining a light emitting element according to another embodiment of the present invention, Figure 5b Yes Figure 5a A cross-sectional view of the light-emitting element taken along line AA'.

[0063] Reference Figure 5a as well as Figure 5b The light emitting element may include a first light emitting portion LE1, a second light emitting portion LE2, and a third light emitting portion LE3 that are horizontally spaced apart from each other on the same plane.

[0064] The first light emitting portion LE1 may include a first n-type semiconductor layer 102, a first active layer 104, a first p-type semiconductor layer 106, and a first ohmic layer 108, and the first active layer 104, the first p-type semiconductor layer 106, and the first ohmic layer 108 may have a mesa structure such that a portion of the first n-type semiconductor layer 102 is exposed. The second light emitting portion LE2 may include a second n-type semiconductor layer 202, a second active layer 204, a second p-type semiconductor layer 206, and a second ohmic layer 208, and the second active layer 204, the second p-type semiconductor layer 206, and the second ohmic layer 208 may have a mesa structure such that a portion of the second n-type semiconductor layer 202 is exposed. The third light emitting portion LE3 may include a third n-type semiconductor layer 302, a third active layer 304, a third p-type semiconductor layer 306, and a third ohmic layer 308, and the third active layer 304, the third p-type semiconductor layer 306, and the third ohmic layer 308 may have a mesa structure such that a portion of the third n-type semiconductor layer 302 is exposed.

[0065] The first pad PD1 may be electrically connected to the first ohmic layer 108 through the first contact pattern CT1, the second pad PD2 may be electrically connected to the second ohmic layer 208 through the second contact pattern CT2, and the third pad PD3 may be electrically connected to the third ohmic layer 308 through the third contact pattern CT3. Each of the first n-type semiconductor layer 102, the second n-type semiconductor layer 202, and the third n-type semiconductor layer 302 may be electrically connected by a common pad CPD connecting the first common contact pattern CCT1, the second common contact pattern CCT2, and the third common contact pattern CCT3.

[0066] In this embodiment, it is exemplarily described that the first n-type semiconductor layer 102 , the second n-type semiconductor layer 202 and the third n-type semiconductor layer 302 are electrically connected to the common pad CPD, but the first ohmic layer 108 , the second ohmic layer 208 and the third ohmic layer 308 may be electrically connected to the common pad CPD.

[0067] For Figure 5a as well as Figure 5b The light emitting element shown in the figure is omitted in detail. Figure 1a , Figure 1b , Figure 2a , Figure 2b , Figure 2c , Figure 3a , Figure 3b , Figure 4a as well as Figure 4b The light emitting elements shown are the same and thus omitted.

[0068] Figure 6a is a plan view for explaining a light emitting element according to another embodiment of the present invention, Figure 6b Yes Figure 6a A cross-sectional view of the light-emitting element taken along lines AA' and BB'.

[0069] Reference Figure 6a as well as Figure 6b The light emitting element may include a first light emitting portion LE1, a second light emitting portion LE2, and a third light emitting portion LE3 which are vertically stacked.

[0070] The first light emitting portion LE1 may include a first n-type semiconductor layer 102, a first active layer 104, a first p-type semiconductor layer 106, and a first ohmic layer 108, which are vertically stacked. The second light emitting portion LE2 may include a second n-type semiconductor layer 202, a second active layer 204, a second p-type semiconductor layer 206, and a second ohmic layer 208, which are vertically stacked. The third light emitting portion LE3 may include a third ohmic layer 308, a third p-type semiconductor layer 306, a third active layer 304, and a third n-type semiconductor layer 302, which are vertically stacked.

[0071] The first pad PD1 may be electrically connected to the first n-type semiconductor layer 102 through a first through pattern VA1 penetrating the first light emitting portion LE1, the second light emitting portion LE2, and the third light emitting portion LE3. The second pad PD2 may be electrically connected to the second n-type semiconductor layer 202 through a second through pattern VA2 penetrating the second light emitting portion LE2 and the third light emitting portion LE3. The third pad PD3 may be electrically connected to the third n-type semiconductor layer 302 through a third through pattern VA3. The common pad CPD may be electrically connected to the first ohmic layer 108, the second ohmic layer 208, and the third ohmic layer 308 through the following through patterns: a fourth through pattern VA4 penetrating the second light emitting portion LE2 and the third light emitting portion LE3 and electrically connected to the first ohmic layer 108; a fifth through pattern VA5 penetrating the third light emitting portion LE3 and electrically connected to the second ohmic layer 208; and a sixth through pattern VA6 electrically connected to the third ohmic layer 308.

[0072] The light emitting element may further include a first adhesive portion AD1, a second adhesive portion AD2, a first color filter CF1, and a second color filter CF2.

[0073] For Figure 6a as well as Figure 6b The light emitting element shown in the figure is omitted in detail. Figure 1a , Figure 1b , Figure 2a , Figure 2b , Figure 2c , Figure 3a , Figure 3b , Figure 4a as well as Figure 4b The light emitting elements shown are the same and thus omitted.

[0074] The following is an exemplary description of Figure 1a , Figure 2a , Figure 2b as well as Figure 2c A method for manufacturing a light-emitting element is shown.

[0075] Figures 7a to 12a is a plan view for explaining a method for manufacturing a light emitting element according to an embodiment of the present invention, Figures 7b to 12b Yes Figures 7a to 12a A cross-sectional view of the light-emitting element taken along line A-A', Figures 7c to 12c Yes Figures 7a to 12a A cross-sectional view of the light-emitting element taken along line BB'.

[0076] Reference Figure 7a , Figure 7b as well as Figure 7c , a first n-type semiconductor layer 102, a first active layer 104, a first p-type semiconductor layer 106, and a first ohmic layer 108 may be sequentially formed on the first substrate 100, thereby forming a first light-emitting portion LE1. A first color filter CF1 may also be formed on the first ohmic layer 108. However, the first color filter CF1 may be omitted. A second n-type semiconductor layer 202, a second active layer 204, a second p-type semiconductor layer 206, and a second ohmic layer 208 may be sequentially formed on a second substrate (not shown), thereby forming a second light-emitting portion LE2. A third n-type semiconductor layer 302, a third active layer 304, a third p-type semiconductor layer 306, and a third ohmic layer 308 may be sequentially formed on a third substrate (not shown), thereby forming a third light-emitting portion LE3. A second color filter CF2 may also be formed on the third ohmic layer 308. However, the second color filter CF2 may be omitted. A first bonding portion AD1 is formed on the first ohmic layer 108 and the second light emitting portion LE2 is bonded, so that the second ohmic layer 208 is bonded to the first bonding portion AD1, and the second substrate can be removed by laser lift-off (LLO: Laser Lift Off) or chemical lift-off (CLO: Chemical Lift Off). A second bonding portion AD2 is formed on the second n-type semiconductor layer 202 and the third light emitting portion LF3 is bonded, so that the third ohmic layer 308 is bonded to the second bonding portion AD2, and the third substrate can be removed by LLO or CLO.

[0077] Reference Figure 8a , 8bAnd 8c, using a first mask (not shown) to etch the third n-type semiconductor layer 302, the third active layer 304 and the third p-type semiconductor layer 306 to expose the third ohmic layer 308, and using a second mask (not shown) to etch the third ohmic layer 308 and the first bonding portion AD1 to expose the second n-type semiconductor layer, and using a third mask (not shown) to etch the second n-type semiconductor layer 202, the second active layer 204 and the second p-type semiconductor layer 206 to expose the second ohmic layer 208, and using a fourth mask (not shown) to etch the second ohmic layer 208 and the first bonding portion AD1 to expose the first ohmic layer 108, and using a fifth mask (not shown) to etch the first ohmic layer 108, the first p-type semiconductor layer 106 and the first active layer 104 to expose the first n-type semiconductor layer 102.

[0078] Reference Figure 9a , Figure 9b as well as Fig.9c , an insulating film IDL covering the etched light emitting element may be formed. The insulating film IDL may include SiO x 、SiN x 、Al x O y and SiO x N y The insulating film IDL may be etched to form an opening exposing the first n-type semiconductor layer 102 , the second n-type semiconductor layer 202 , the third n-type semiconductor layer 302 , the first ohmic layer 108 , the second ohmic layer 208 , and the third ohmic layer 308 .

[0079] Reference Fig.10a , Fig.10b as well as Fig.10c , it is possible to form: a first contact pattern CT1, which is electrically in contact with the first n-type semiconductor layer 102 exposed through the opening of the insulating film IDL; a second contact pattern CT2, which is electrically in contact with the second n-type semiconductor layer 202 exposed through the opening of the insulating film IDL; a third contact pattern CT3, which is electrically in contact with the third n-type semiconductor layer 302 exposed through the opening of the insulating film IDL; a first common contact pattern CCT1, which is electrically connected to the first ohmic layer 108 and the second ohmic layer 208 exposed by the opening of the insulating film IDL; and a second common contact pattern CCT2, which is electrically in contact with the third ohmic layer 308 exposed through the opening of the insulating film IDL.

[0080] Reference Fig.11a , Fig.11b as well as Fig.11c, the following extension patterns can be formed: a first extension pattern EL1, which is electrically in contact with the first contact pattern CT1 and extends along the side surfaces of the first light-emitting portion LE1, the second light-emitting portion LE2 and the third light-emitting portion LE3 to the insulating film IDL formed on the flat first n-type semiconductor layer 102; a second extension pattern EL2, which is electrically in contact with the second contact pattern CT2 and extends along the side surfaces of the first light-emitting portion LE1, the second light-emitting portion LE2 and the third light-emitting portion LE3 to the insulating film IDL formed on the flat first n-type semiconductor layer 102; a third extension pattern EL3, which is electrically in contact with the third contact pattern CT3 and extends along the side surfaces of the first light-emitting portion LE1, the second light-emitting portion LE2 and the third light-emitting portion LE3 to the insulating film IDL formed on the flat first n-type semiconductor layer 102; and a common extension pattern CEL, which is electrically in contact with the first common contact pattern CCT1 and the second common contact pattern CCT2 and extends along the side surfaces of the first light-emitting portion LE1, the second light-emitting portion LE2 and the third light-emitting portion LE3 to the insulating film IDL formed on the flat first n-type semiconductor layer 102.

[0081] Reference Fig.12a , Figure 12b as well as Fig.12c , a passivation film PVT covering the first light emitting portion LE1, the second light emitting portion LE2, the third light emitting portion LE3, the first extension pattern EL1, the second extension pattern EL2, the third extension pattern EL3 and the common extension pattern CEL can be formed. The passivation film PVT may include at least one inorganic substance or at least one organic substance. As the organic substance, it may include acryl, glass, polymer, resist, polyimide, polyamide (PA: Polyamide), spin on glass (SOG: Spin On Glass), benzocyclobutene (BCB: benzocyclobutene), hydrogen silsesquioxane (HSQ: hydrogen silsesquioxane) or SU-8 photoresist, etc., and as the inorganic substance, it may include SiO x 、SiN x 、Al x O y and SiO x N y The passivation film PVT may be formed to be colorless and transparent or may have a variety of colors. For example, the passivation film PVT may be provided to be transparent or may be formed to be black or white, etc.

[0082] The passivation film PVT is etched, so that through holes (not shown) exposing the first extension pattern EL1 , the second extension pattern EL2 , the third extension pattern EL3 , and the common extension pattern CEL can be formed.

[0083] The through holes are filled with a conductive material, so that a first through pattern VA1, a second through pattern VA2, a third through pattern VA3, and a common through pattern CVA can be formed respectively. Subsequently, a first pad PD1 electrically connected to the first through pattern VA1, a second pad PD2 electrically connected to the second through pattern VA2, a third pad PD3 electrically connected to the third through pattern VA3, and a common pad CPD electrically connected to the common through pattern CVA can be formed respectively. At this point, a plurality of light-emitting elements LED can be formed on the first substrate SUB.

[0084] Fig.13a as well as Fig.13b It is a cross-sectional view for explaining a method of mounting a light emitting element manufactured according to an embodiment of the present invention on a mounting substrate.

[0085] Reference Fig.13a And 13b, the first substrate 100 formed with the light emitting element LED is turned upside down so that it can face the target mounting substrate SUB. After the mask pattern MSK is formed on one side of the first substrate 100, a selective laser lift-off (selective LLO) is performed on the first substrate 100, and the light emitting element LED can be selectively separated from the substrate considering the distance.

[0086] A first substrate pad SPD1 , a second substrate pad SPD2 , a third substrate pad SPD3 , and a common substrate pad SCPD may be formed at positions corresponding to the first pad PD1 , the second pad PD2 , the third pad PD3 , and the common pad CPD of each separated light emitting element LED, respectively.

[0087] The first pad PD1, the second pad PD2, the third pad PD3 and the common pad CPD are respectively bonded to the first substrate pad SPD1, the second substrate pad SPD2, the third substrate pad SPD3 and the common substrate pad SCPD using adhesive and conductive materials such as solder balls SD, so that the light emitting element LED can be mounted on the substrate SUB.

[0088] Fig.14 as well as Fig.15 An electronic device to which a display device according to an embodiment of the present invention is applied is illustrated.

[0089] Reference Fig.14 The electronic device may be a watch. The electronic device may include: a housing HS; and a display portion DP that can be rolled in a manner of entering and exiting the inside and outside of the housing HS. The display portion DP may include Figure 1a , Figure 1b , Figure 2a , Figure 2b , Figure 2c , Figure 3a , Figure 3b , Figure 4a as well as Figure 4b The display device described in.

[0090] According to an embodiment, if the display portion DP is dragged by an electrostatic method and a piezoelectric method, the area of ​​the display portion DP can be adjusted. To implement this solution, a plurality of light emitting elements of the display portion DP can be electrically connected to an independent driving circuit.

[0091] Reference Fig.15 The electronic device may be a rollable screen. The electronic device may include: a housing HS; and a display portion DP that can be rolled in and out of the housing HS. The display portion DP may include Figure 1a , Figure 1b , Figure 2a , Figure 2b , Figure 2c , Figure 3a , Figure 3b , Figure 4a as well as Figure 4b The display device described in.

[0092] According to the present embodiment, a wristwatch and a rollable screen are exemplarily described as electronic devices, but the display device according to the present invention can be applied to various electronic devices.

[0093] Although the embodiments of the present invention are described above with reference to the accompanying drawings, it is understood by those with ordinary knowledge in the technical field to which the present invention belongs that the present invention can be implemented in other specific forms without changing its technical ideas or essential features. Therefore, it should be understood that the embodiments described above are illustrative in all aspects and are not restrictive.

Claims

1. A display device, characterized in that: include: Flexible substrates; a plurality of light emitting elements spaced apart from each other on the flexible substrate; a light blocking film covering a portion of each of the plurality of light emitting elements to define a light extraction surface, wherein the distances between the light extraction surfaces are the same as each other, The plurality of light emitting elements are spaced apart by a first distance along a first direction and spaced apart by a second distance along a second direction perpendicular to the first direction. When the first distance is greater than the second distance, the area of ​​the light-blocking film covering the light-emitting element along the second direction is larger than the area of ​​the light-blocking film covering the light-emitting element along the first direction.

2. The display device according to claim 1, wherein: The flexible substrate is curled along the first direction.

3. The display device according to claim 1, wherein: Also includes: a common circuit, electrically connected to the plurality of light emitting elements, Wherein, the common circuit has a grid structure on the flexible substrate.

4. The display device according to claim 1, wherein: Also includes: The protective layer covers the plurality of light emitting elements on the flexible substrate and includes a material that transmits visible light.

5. The display device according to claim 1, wherein: The flexible substrate has a lower hardness than that of each of the plurality of light emitting elements.

6. The display device according to claim 1, wherein: Each of the plurality of light emitting elements includes a first light emitting portion, a second light emitting portion, and a third light emitting portion that are horizontally spaced apart from each other on the flexible substrate.

7. The display device according to claim 1, wherein: Each of the plurality of light emitting elements includes a first light emitting portion, a second light emitting portion, and a third light emitting portion vertically stacked on the flexible substrate.

8. The display device according to claim 7, characterized in that: The third light emitting portion has a smaller width than the second light emitting portion, The second light emitting portion has a smaller width than the first light emitting portion.

9. The display device according to claim 1, wherein: Each of the plurality of light emitting elements has a width that gradually narrows upward from one surface of the flexible substrate.

10. The display device according to claim 1, wherein: The first distance and the second distance between the plurality of light emitting elements are 8 to 15 times a critical dimension of each of the plurality of light emitting elements.

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