Apparatus for inspecting light emitting elements and method of inspecting light emitting elements using the apparatus

Abstract

An apparatus for inspecting light-emitting elements and a method for inspecting light-emitting elements using the apparatus are provided. The apparatus includes: a flow path unit extending in one direction and including a flow path, wherein a solution containing light-emitting elements moves along the flow path; at least one alignment unit, the flow path extending from at least a portion of the flow path unit to the at least one alignment unit; a stacking unit at an end of the flow path unit and wherein the light-emitting elements are stacked; and a plurality of alignment electrodes on the outer surface of the alignment unit.

Description

Technical Field

[0001] Implementations of this disclosure relate to an apparatus for inspecting light-emitting elements and a method for inspecting light-emitting elements using said apparatus. Background Technology

[0002] With the development of multimedia, display devices are becoming increasingly important. Therefore, various types (or categories) of display devices are being used, such as organic light-emitting diode (OLED) displays and liquid crystal displays (LCDs).

[0003] A display device is a means for displaying images and includes a display panel, such as an organic light-emitting display panel or a liquid crystal display panel. As a light-emitting display panel, the display panel may include light-emitting elements, such as light-emitting diodes (LEDs). For example, an LED may be an organic light-emitting diode (OLED) that uses organic materials as fluorescent materials, or it may be an inorganic LED that uses inorganic materials as fluorescent materials.

[0004] The light-emitting elements described above can be placed in a solution mixed with a solvent and then transferred or printed onto a substrate. However, defects in the light-emitting elements themselves cause a decrease in the brightness of the pixels in the display device. Summary of the Invention

[0005] One aspect of the embodiments of this disclosure provides an apparatus for inspecting defects in light-emitting elements.

[0006] An aspect of the embodiments of this disclosure also provides a method for manufacturing a display device with reduced defects by eliminating defective light-emitting elements (or by reducing the number of defective light-emitting elements).

[0007] However, the embodiments of this disclosure are not limited to those set forth herein. These and other aspects of the embodiments of this disclosure will become more apparent to those skilled in the art upon which this disclosure pertains by referring to the following detailed description of this disclosure.

[0008] According to an embodiment of the present disclosure, an apparatus for inspecting light-emitting elements is provided, the apparatus comprising: a flow path unit extending in one direction and including a flow path, wherein a solution containing light-emitting elements moves along the flow path; at least one alignment unit, the flow path extending from at least a portion of the flow path unit to the at least one alignment unit; a packing unit at an end of the flow path unit and wherein the light-emitting elements are stacked therein; and a plurality of alignment electrodes on the outer surface of the alignment unit.

[0009] In one embodiment, the flow path unit includes an inlet at the upper end of the flow path unit and an outlet at the lower end of the flow path unit, and each of the inlet and the outlet has a rectangular planar shape.

[0010] In an implementation, the planar shape of the flow path is the same as (e.g., substantially the same) the planar shape of the inlet or the outlet.

[0011] In one embodiment, the alignment unit includes a first alignment region and a second alignment region, and the first alignment region and the second alignment region are spaced apart from each other in one direction.

[0012] In one implementation, the diameter of the first alignment region or the second alignment region is greater than the length of the major axis of each of the light-emitting elements.

[0013] In one embodiment, the stacking unit includes: a storage component extending from the flow path unit, a plurality of inspection electrodes on two sides within the storage component, filter baffles at the upper and lower ends of the storage component, respectively, and an electrode moving component outside the flow path unit that moves the inspection electrodes.

[0014] In one embodiment, the inspection electrode is spaced apart from the alignment electrode.

[0015] In one embodiment, the filter baffle includes a first filter baffle at the upper end of the storage component and a second filter baffle at the lower end of the storage component, and the first filter baffle and the second filter baffle open or close the upper end and the lower end of the storage component, respectively.

[0016] According to embodiments of this disclosure, a method is provided for inspecting light-emitting elements using an apparatus for inspecting light-emitting elements, the apparatus comprising: a flow path unit extending in one direction and including a flow path; at least one alignment unit, the flow path extending from at least a portion of the flow path unit to the at least one alignment unit; a stacking unit at an end of the flow path unit and wherein light-emitting elements are stacked; and a plurality of alignment electrodes on the outer surface of the alignment unit, and the method comprising: preparing a solution in which the light-emitting elements are mixed with a solvent; sorting the light-emitting elements by length; injecting the solution into the inspection apparatus and aligning the light-emitting elements using the alignment unit; aligning the aligned light-emitting elements using the stacking unit; and determining whether the light-emitting elements are defective by inspecting the resistance and brightness of the light-emitting elements.

[0017] In the implementation scheme, surface acoustic wave technology is used to sort light-emitting elements with a set length, and the length of each of the light-emitting elements is 3.8 μm to 4.2 μm.

[0018] In the implementation scheme, the surface acoustic wave has a frequency band of 165MHz to 175MHz.

[0019] In one embodiment, the alignment unit rotates and aligns the light-emitting element by applying an electrical signal to the alignment electrode to generate an electric field.

[0020] In one embodiment, the stacking unit includes: a plurality of inspection electrodes and an electrode moving component for horizontally moving the inspection electrodes, and the electrode moving component causes the inspection electrodes to contact two sides of each light-emitting element aligned in the stacking unit to measure the resistance and brightness of the light-emitting element.

[0021] In one implementation, when the light-emitting element is determined to be defect-free in terms of resistance and brightness, the light-emitting element is obtained; when the light-emitting element is determined to be defective in terms of resistance or brightness, the light-emitting element is re-injected into the solution, and the re-injected light-emitting element is mixed again using the surface acoustic wave technology.

[0022] In the implementation, the solution in which the re-injected light-emitting elements are mixed is repeatedly sorted by length of the light-emitting elements, the solution is injected into the inspection device and aligned using the alignment unit, aligned using the stacking unit, and the light-emitting elements are aligned to determine whether the light-emitting elements are defective by checking the resistance and brightness of the light-emitting elements. Attached Figure Description

[0023] These and / or other aspects of the implementation scheme will become apparent and more readily understood from the following description of the implementation scheme in conjunction with the accompanying drawings, in which:

[0024] Figure 1 This is a schematic plan view of the display device according to the implementation scheme;

[0025] Figure 2 This is a plan view of the pixels of the display device according to the implementation scheme;

[0026] Figure 3 It is along Figure 2 Cross-sectional views taken from lines Q1-Q1', Q2-Q2', and Q3-Q3';

[0027] Figure 4 It is a schematic perspective view of the light-emitting element according to the implementation scheme;

[0028] Figure 5 This is a schematic diagram of the light-emitting element according to the implementation plan;

[0029] Figure 6 It is a schematic perspective view of a device for inspecting light-emitting elements according to the implementation plan;

[0030] Figure 7 This is a schematic perspective view of the alignment unit of a device for inspecting light-emitting elements according to the implementation scheme;

[0031] Figure 8 This is a schematic perspective view of the stacked units of a device for inspecting light-emitting elements according to the implementation scheme;

[0032] Figure 9 This is a schematic perspective view illustrating the opening and closing operations of the filter baffle of the stacking unit according to the embodiment;

[0033] Figure 10 and Figure 11 This is a schematic perspective view illustrating the operation of the inspection electrode of the stacking unit according to the embodiment;

[0034] Figure 12 This is a flowchart illustrating a method for inspecting light-emitting elements;

[0035] Figure 13 This is a schematic diagram illustrating a method for sorting the dimensions of light-emitting elements;

[0036] Figure 14 This is a schematic diagram illustrating a method for using hybrid light-emitting elements;

[0037] Figure 15 This is a schematic diagram of acoustic flow;

[0038] Figure 16 This is a flowchart illustrating a method for manufacturing a display device according to an embodiment;

[0039] Figure 17 This is a cross-sectional view illustrating a portion of the process for manufacturing a display device according to an embodiment;

[0040] Figure 18 This is a plan view of a sub-pixel at a stage in the process of manufacturing a display device according to the implementation scheme;

[0041] Figure 19 This is a cross-sectional view illustrating a portion of the process for manufacturing a display device according to an embodiment;

[0042] Figure 20 This is a plan view of a sub-pixel at a stage in the process of manufacturing a display device according to the implementation scheme;

[0043] Figure 21 This is a cross-sectional view illustrating a portion of the process for manufacturing a display device according to an embodiment; and

[0044] Figure 22 This is a plan view of a subpixel at one stage of the process of manufacturing a display device according to the implementation scheme. Detailed Implementation

[0045] Embodiments of this disclosure will now be described more fully below with reference to the accompanying drawings, in which exemplary embodiments of this disclosure are illustrated. However, the subject matter of this disclosure may be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0046] It should also be understood that when a layer is referred to as being "on" another layer or substrate, it can be directly on that other layer or substrate, or there can be an intermediate layer. The same reference numerals refer to the same components throughout the specification.

[0047] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the spirit and scope of this disclosure, the first element discussed below may be referred to as the second element. Similarly, the second element may also be referred to as the first element.

[0048] Each feature of the various embodiments of this disclosure can be combined with each other, either partially or entirely, and various interlocking and drive configurations are technically possible. Each embodiment can be implemented independently of each other, or can be implemented together in association.

[0049] Some embodiments will be described below with reference to the accompanying drawings.

[0050] Figure 1 It is a schematic plan view of the display device according to the implementation scheme.

[0051] refer to Figure 1The display device 10 displays moving or still images. The display device 10 can refer to any suitable electronic device that provides or has a display screen. Examples of display devices 10 may include televisions, laptop computers, monitors, billboards, Internet of Things (IoT) products, mobile phones, smartphones, tablet PCs, electronic watches, smartwatches, watch phones, head-mounted displays, mobile communication terminals, electronic notebooks, e-books, portable multimedia players (PMPs), navigation devices, game consoles, digital cameras and / or camcorders, all of which provide or have a display screen.

[0052] Display device 10 includes a display panel that provides a display screen. Examples of display panels include inorganic light-emitting diode (LED) display panels, organic light-emitting diode (OLED) display panels, quantum dot (QD) light-emitting diode (OLED) display panels, plasma display panels, and field emission display panels. Examples of the use of an inorganic LED display panel as the display panel will be described below, but this disclosure is not limited to this, and other display panels may be used provided the same technical intent applies.

[0053] The shape of the display device 10 can be modified in various ways. For example, the display device 10 can have various suitable shapes, such as a horizontal rectangle, a vertical rectangle, a square, a quadrilateral with rounded corners (vertices), other polygons, or a circle. The shape of the display area DPA of the display device 10 can also be similar to (e.g., corresponding to) the overall shape of the display device 10. Figure 1 In this configuration, each of the display device 10 and the display area DPA is shaped like a horizontal elongated rectangle.

[0054] Display device 10 may include a display area DPA and a non-display area NDA. The display area DPA may be an area in which a screen (or image) can be displayed, and the non-display area NDA may be an area in which a screen (or image) is not displayed (e.g., the non-display area NDA may be an area not designed to display an image). The display area DPA may also be referred to as an active area, and the non-display area NDA may also be referred to as a non-active area. The display area DPA may typically occupy the center of the display device 10.

[0055] The display area DPA may include a plurality of pixels PX. The pixels PX may be arranged in a matrix direction. Each of the pixels PX may be rectangular or square in a planar view. However, this disclosure is not limited thereto, and each of the pixels PX may also have a rhomboid planar shape, said rhomboid planar shape having each side inclined relative to a one direction. The pixels PX may be arranged alternately in a stripe pattern or pattern( (This is a registered trademark of Samsung Display Co., Ltd.) Furthermore, each of the pixels (PX) may include one or more light-emitting elements that emit light of a set or specific wavelength band to display a set or specific color.

[0056] A non-display area NDA may surround (e.g., at least partially surround) the display area DPA. The non-display area NDA may completely or partially surround the display area DPA. The display area DPA may be rectangular, and the non-display area NDA may be adjacent to all four sides of the display area DPA. The non-display area NDA may form a baffle of the display device 10. In each non-display area NDA, wiring or circuit drivers included in the display device 10 may be provided, or external devices may be mounted.

[0057] Figure 2 This is a plan view of the pixels PX of the display device 10 according to the implementation scheme.

[0058] refer to Figure 2 Each of the plurality of pixels PX can include a plurality of sub-pixels PXn (where n is an integer from 1 to 3). For example, a pixel PX can include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. The first sub-pixel PX1 can emit light of a first color, the second sub-pixel PX2 can emit light of a second color, and the third sub-pixel PX3 can emit light of a third color. For example, the first color can be blue, the second color can be green, and the third color can be red. However, this disclosure is not limited thereto, and the sub-pixels PXn can also emit light of the same (e.g., substantially the same) color. Furthermore, although in Figure 2 A pixel PX comprises three sub-pixels PXn, but this disclosure is not limited thereto, and a pixel PX may also include additional sub-pixels PXn.

[0059] Each sub-pixel PXn of the display device 10 may include an emitting region EMA and a non-emitting region. The emitting region EMA may be a region in which a light-emitting element 30 is provided to output light of a set or specific wavelength band, and the non-emitting region may be a region in which the light-emitting element 30 is not provided and no light is output from it because the light emitted from the light-emitting element 30 does not reach the region (or substantially does not reach the region). The emitting region EMA may include a region in which a light-emitting element 30 is provided and in which the light emitted from the light-emitting element 30 is output to a region adjacent to the light-emitting element 30.

[0060] However, this disclosure is not limited thereto, and the emission region EMA may also include an area from which light emitted from the light-emitting element 30 is output after being reflected or refracted by other components of the display device. Multiple light-emitting elements 30 may be present in each sub-pixel PXn, and the area providing the light-emitting element 30 and the area adjacent to that area may form the emission region EMA.

[0061] In the emitting region EMA, contact electrodes CNE1 and CNE2 can be configured to overlap with electrodes 21 and 22 respectively and contact (e.g., physically contact) one side and the other side of each light-emitting element 30. Contact electrodes CNE1 and CNE2 can be connected to electrodes 21 and 22 respectively through openings OP. The structure of electrodes 21 and 22 and contact electrodes CNE1 and CNE2 will be further described below.

[0062] Furthermore, each sub-pixel PXn may include a cut-out region CBA in a non-emitting region. The cut-out region CBA may be on the side of the emitting region EMA in the second direction D2. The cut-out regions CBA may be between the emitting regions EMA of adjacent sub-pixels PXn in the second direction D2. Multiple emitting regions EMA and multiple cut-out regions CBA may be arranged in the display area DPA of the display device 10. For example, the emitting regions EMA and cut-out regions CBA may be arranged repeatedly in the first direction D1 and alternately in the second direction D2. Furthermore, the gap between the cut-out regions CBA in the first direction D1 may be smaller than the gap between the emitting regions EMA in the first direction D1. A second block BNL2 may be located between the cut-out regions CBA and the emitting regions EMA, and the gap between the cut-out regions CBA and the emitting regions EMA may vary depending on the width of the second block BNL2. Light may not be output from the cut-out regions CBA (or may not be output substantially from the cut-out regions CBA) because the light-emitting element 30 is not in the cut-out regions CBA, but a portion of each of the electrodes 21 and 22 in each sub-pixel PXn may be in the cut-out regions CBA. Electrodes 21 and 22 in each sub-pixel PXn can be separated from each other (e.g., spaced apart) in the cut region CBA.

[0063] Figure 3 It is along Figure 2 Cross-sectional views taken from lines Q1-Q1', Q2-Q2', and Q3-Q3'. Figure 3 Examples of cross Figure 2 The cross-section of the two ends of the light-emitting element 30 in the first sub-pixel PX1.

[0064] Combination Figure 2 refer to Figure 3The display device 10 may include a substrate 11, and a semiconductor layer, a plurality of conductive layers, and a plurality of insulating layers on the first substrate 11. The semiconductor layer, conductive layers, and insulating layers may constitute the circuit layer and the light-emitting element layer of the display device 10.

[0065] For example, substrate 11 may be an insulating substrate (e.g., an electrically insulating substrate). Substrate 11 may be made of an insulating material such as glass, quartz, and / or polymer resin. Furthermore, substrate 11 may be a rigid substrate, but it may also be a flexible substrate that can be bent, folded, and / or rolled up.

[0066] A light-blocking layer BML may be present on the substrate 11. The light-blocking layer BML overlaps with the active layer ACT1 of the first transistor T1 of the display device 10. The light-blocking layer BML may contain a light-blocking material to prevent or reduce light penetration to the active layer ACT1 of the first transistor T1. For example, the light-blocking layer BML may be made of an opaque metallic material that blocks or reduces light transmission. However, this disclosure is not limited thereto. In some cases, the light-blocking layer BML may be omitted.

[0067] The buffer layer 12 may be entirely on the substrate 11 having the light-blocking layer BML. The buffer layer 12 may be formed on the substrate 11 to protect the first transistor T1 of the pixel PX from moisture introduced through the substrate 11 (which is susceptible to moisture penetration). The buffer layer 12 may also perform a surface planarization function. The buffer layer 12 may be composed of multiple inorganic layers stacked alternately. For example, the buffer layer 12 may be a multilayer comprising alternating stacks of inorganic layers selected from silicon oxide, silicon nitride, and silicon oxide nitride.

[0068] A semiconductor layer is located on buffer layer 12. The semiconductor layer may include the active layer ACT1 of the first transistor T1. The active layer ACT1 may partially overlap with the gate electrode G1 of the first gate conductive layer, as will be further described below.

[0069] Although only the first transistor T1 is illustrated in the accompanying drawings, which is included in each sub-pixel PXn of the display device 10, the present disclosure is not limited thereto. The display device 10 may also include additional transistors. For example, by including one or more transistors in addition to the first transistor T1, the display device 10 may include two, three, or more than three transistors in each sub-pixel PXn.

[0070] The semiconductor layer can comprise polycrystalline silicon, monocrystalline silicon, oxide semiconductors, etc. When the semiconductor layer comprises an oxide semiconductor, each active layer ACT1 can include multiple conductive regions (ACT_a and ACT_b) and a channel region ACT_c between them. The oxide semiconductor can include indium (In)-containing oxide semiconductors. For example, the oxide semiconductor can include indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), indium zinc tin oxide (IZTO), indium gallium tin oxide (IGTO), and / or indium gallium zinc tin oxide (IGZTO).

[0071] In this implementation, the semiconductor layer may comprise polycrystalline silicon. Polycrystalline silicon can be formed by crystallizing amorphous silicon. In this case, each of the conductive regions ACT_a and ACT_b of the active layer ACT1 may be a doped region doped with impurities.

[0072] The first gate insulating layer 13 is on the semiconductor layer and the buffer layer 12. The first gate insulating layer 13 may be on the buffer layer 12 having the semiconductor layer. The first gate insulating layer 13 may serve as the gate insulating layer for each transistor. The first gate insulating layer 13 may be an inorganic layer containing inorganic materials (e.g., silicon oxide, silicon nitride, and / or silicon nitride), or may have a structure in which the above materials are stacked.

[0073] A first gate conductive layer is located on a first gate insulating layer 13. The first gate conductive layer may include a gate electrode G1 of a first transistor T1 and a first capacitor electrode CSE1 of a storage capacitor. The gate electrode G1 may overlap with the channel region ACT_c of the active layer ACT1 in the thickness direction. The first capacitor electrode CSE1 may overlap with a second capacitor electrode CSE2, which will be further described herein, in the thickness direction. In an embodiment, the first capacitor electrode CSE1 may be integratedly coupled to the gate electrode G1. The first capacitor electrode CSE1 may overlap with the second capacitor electrode CSE2 in the thickness direction, and a storage capacitor may be formed between the first capacitor electrode CSE1 and the second capacitor electrode CSE2.

[0074] The first gate conductive layer may be, but is not limited to, a single layer or multiple layers made of any one or more of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and their alloys.

[0075] The first interlayer insulating layer 15 is located on the first gate conductive layer. The first interlayer insulating layer 15 can function as an insulating layer (e.g., an electrically insulating layer) between the first gate conductive layer and other layers on the first gate conductive layer. Furthermore, the first interlayer insulating layer 15 can cover and protect the first gate conductive layer. The first interlayer insulating layer 15 can be an inorganic layer comprising inorganic materials (e.g., silicon oxide, silicon nitride, and / or silicon nitride), or can have a structure in which the above materials are stacked.

[0076] The first data conduction layer is on the first interlayer insulating layer 15. The first data conduction layer may include the first source electrode SE1 and the first drain electrode DE1 of the first transistor T1, the data line DTL, and the second capacitor electrode CSE2.

[0077] The first source electrode SE1 and the first drain electrode DE1 of the first transistor T1 can contact the conductive regions ACT_a and ACT_b of the active layer ACT1 through contact holes penetrating the first interlayer insulating layer 15 and the first gate insulating layer 13, respectively. Furthermore, the first source electrode SE1 of the first transistor T1 can be electrically connected to the light-blocking layer BML through another contact hole.

[0078] In some implementations, the data line DTL can transmit data signals to other transistors included in the display device 10. For example, the data line DTL can be connected to the source / drain electrode of other transistors to transmit received signals to the source / drain electrode.

[0079] The second capacitor electrode CSE2 overlaps with the first capacitor electrode CSE1 in the thickness direction. In an embodiment, the second capacitor electrode CSE2 can be integratedly connected to the first source electrode SE1.

[0080] The first data conduction layer may be, but is not limited to, a single layer or multiple layers made of any one or more of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and their alloys.

[0081] The second interlayer insulating layer 17 is located on the first data conductive layer. The second interlayer insulating layer 17 can function as an insulating layer (e.g., an electrical insulating layer) between the first data conductive layer and other layers on the first data conductive layer. Furthermore, the second interlayer insulating layer 17 can cover and protect the first data conductive layer. The second interlayer insulating layer 17 can be an inorganic layer containing inorganic materials (e.g., silicon oxide, silicon nitride, and / or silicon nitride), or it can have a structure in which the above materials are stacked.

[0082] The second data conduction layer is located on the second interlayer insulating layer 17. The second data conduction layer may include a first voltage wiring VL1, a second voltage wiring VL2, and a first conductive pattern CDP. A high potential voltage (or a first power supply voltage) supplied to the first transistor T1 can be applied to the first voltage wiring VL1, and a low potential voltage (or a second power supply voltage) supplied to the second electrode 22 can be applied to the second voltage wiring VL2. Furthermore, during the manufacturing process of the display device 10, alignment signals for aligning the light-emitting element 30 or for aligning the light-emitting element 30 can be transmitted to the second voltage wiring VL2.

[0083] The first conductive pattern CDP can be connected to the second capacitor electrode CSE2 through contact holes formed in the second interlayer insulating layer 17. The second capacitor electrode CSE2 can be integrated with the first source electrode SE1 of the first transistor T1, and the first conductive pattern CDP can be electrically connected to the first source electrode SE1. The first conductive pattern CDP can also contact (e.g., physically contact) the first electrode 21, which will be further described herein, and the first transistor T1 can transmit a first power supply voltage received from the first voltage wiring VL1 to the first electrode 21 through the first conductive pattern CDP. Although the second data transmission layer includes a second voltage wiring VL2 and a first voltage wiring VL1 in the figures, this disclosure is not limited thereto. The second data transmission layer may also include additional first voltage wiring VL1 and additional second voltage wiring VL2.

[0084] The second data conduction layer may be, but is not limited to, a single layer or multiple layers made of any one or more of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and their alloys.

[0085] The first planarization layer 19 is on the second data transmission layer. The first planarization layer 19 may contain an organic insulating material, such as an organic material like polyimide (PI), and may perform a surface planarization function.

[0086] Multiple first blocks BNL1, multiple electrodes 21 and 22, a light-emitting element 30, multiple contact electrodes CNE1 and CNE2, and a second block BNL2 are on the first planarization layer 19. In addition, multiple insulating layers PAS1 to PAS3 may be on the first planarization layer 19.

[0087] The first block BNL1 can be directly on the first planarization layer 19. The first block BNL1 can extend in each sub-pixel PXn along the second direction D2, but can be within the emission region EMA, without extending to other adjacent sub-pixels PXn along the second direction D2. Furthermore, the first blocks BNL1 can be spaced apart from each other along the first direction D1, and the light-emitting elements 30 can be positioned between them. The first blocks BNL1 can form a linear pattern in each sub-pixel PXn within the display region DPA of the display device 10. Although two first blocks BNL1 are illustrated in the figures, this disclosure is not limited thereto. For example, additional first blocks BNL1 may be included, depending on the number of electrodes 21 and 22.

[0088] At least a portion of each of the first blocks BNL1 may protrude from the upper surface of the first planarization layer 19. The protruding portion of each of the first blocks BNL1 may have a sloping side surface, and light emitted from the light-emitting element 30 may be reflected by electrodes 21 and 22 on the first block BNL1 to travel upwards toward the first planarization layer 19. The first block BNL1 may provide an area including the light-emitting element 30 while acting as a reflective barrier to reflect light emitted from the light-emitting element 30 in an upward direction. The side surfaces of the first block BNL1 may be sloping in a linear shape (e.g., the side surfaces may be linear surfaces). However, this disclosure is not limited thereto, and the first block BNL1 may also have a semi-circular or semi-elliptical outer surface. The first block BNL1 may contain an organic insulating material such as polyimide (PI), but this disclosure is not limited thereto.

[0089] Electrodes 21 and 22 are located on the first block BNL1 and the first planarization layer 19. Electrodes 21 and 22 may include a first electrode 21 and a second electrode 22. The first electrode 21 and the second electrode 22 may extend in a second direction D2 and may be spaced apart from each other in a first direction D1.

[0090] The first electrode 21 and the second electrode 22 may extend in each sub-pixel PXn along the second direction D2 and may be separated from other electrodes 21 and 22 in the cut region CBA (e.g., spaced apart). For example, the cut region CBA may be between the emission regions EMA of adjacent sub-pixels PXn in the second direction D2, and the first electrode 21 and the second electrode 22 may be separated in the cut region CBA from another first electrode 21 and another second electrode 22 in adjacent sub-pixels PXn in the second direction D2 (e.g., spaced apart in the cut region CBA). However, this disclosure is not limited thereto, and some electrodes 21 and 22 may not be separated in each sub-pixel PXn, but may extend beyond adjacent sub-pixels PXn in the second direction D2 (e.g., any one of the first electrode 21 and the second electrode 22 may extend from one sub-pixel PXn to another), or any one of the first electrode 21 and the second electrode 22 may be separated (e.g., spaced apart).

[0091] The first electrode 21 can be electrically connected to the first transistor T1 through the first contact hole CT1, and the second electrode 22 can be electrically connected to the second voltage wiring VL2 through the second contact hole CT2. For example, in the portion of the second block BNL2 extending in the first direction D1, the first electrode 21 can contact (e.g., physically contact) the first conductive pattern CDP through the first contact hole CT1 penetrating the first planarization layer 19. In the portion of the second block BNL2 extending in the first direction D1, the second electrode 22 can also contact (e.g., physically contact) the second voltage wiring VL2 through the second contact hole CT2 penetrating the first planarization layer 19. However, this disclosure is not limited thereto. In an embodiment, the first contact hole CT1 and the second contact hole CT2 can be in the emitter region EMA surrounded by the second block BNL2 so as not to overlap with the second block BNL2.

[0092] Although a first electrode 21 and a second electrode 22 are shown in the accompanying drawings for each sub-pixel PXn, this disclosure is not limited thereto, and more first electrodes 21 and second electrodes 22 may exist in each sub-pixel PXn. Furthermore, the first electrodes 21 and second electrodes 22 in each sub-pixel PXn do not necessarily extend in one direction, but can be in various suitable structures. For example, the first electrodes 21 and second electrodes 22 may be partially bent or folded, or either electrode may surround the other electrode.

[0093] The first electrode 21 and the second electrode 22 can be directly on the first block BNL1, respectively. The first electrode 21 and the second electrode 22 can each be formed to have a width greater than that of the first block BNL1. For example, the first electrode 21 and the second electrode 22 can each cover the outer surface of the first block BNL1. The first electrode 21 and the second electrode 22 can each be on the side surface of the first block BNL1, and the gap between the first electrode 21 and the second electrode 22 can be smaller than the gap between the first blocks BNL1. Furthermore, at least a portion of each of the first electrode 21 and the second electrode 22 can be directly on the first planarization layer 19, and therefore this portion can be located in the same (e.g., substantially the same) plane. However, this disclosure is not limited thereto. In some cases, the width of electrodes 21 and 22 can be smaller than the width of the first block BNL1. However, each of electrodes 21 and 22 can cover at least one side surface of the first block BNL1 to reflect light emitted from the light-emitting element 30.

[0094] Each electrode 21 or 22 may contain a conductive material with high reflectivity (e.g., a conductive material). For example, each electrode 21 or 22 may contain a metal such as silver (Ag), copper (Cu), and / or aluminum (Al) as a material with high reflectivity, or it may be an alloy containing aluminum (Al), nickel (Ni), and / or lanthanum (La). Each electrode 21 or 22 may reflect light that has traveled from the light-emitting element 30 toward the side surface of the first block BNL1 toward above each sub-pixel PXn.

[0095] However, this disclosure is not limited thereto, and each electrode 21 or 22 may further comprise a transparent conductive material. For example, each electrode 21 or 22 may comprise materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and / or indium tin zinc oxide (ITZO). In some embodiments, each electrode 21 or 22 may have a structure in which the transparent conductive material and the metallic material having high reflectivity are each stacked in one or more layers, or may be formed as a single layer comprising a transparent conductive material and a metallic material. For example, each electrode 21 or 22 may have a stacked structure of ITO / Ag / ITO, ITO / Ag / IZO, or ITO / Ag / ITZO / IZO.

[0096] Electrodes 21 and 22 can be electrically connected to the light-emitting element 30, and a set or predetermined voltage can be applied to electrodes 21 and 22, so that the light-emitting element 30 can emit light. Electrodes 21 and 22 can be electrically connected to the light-emitting element 30 through contact electrodes CNE1 and CNE2, and the electrical signals transmitted to electrodes 21 and 22 can be transmitted to the light-emitting element 30 through contact electrodes CNE1 and CNE2.

[0097] Either the first electrode 21 or the second electrode 22 may be electrically connected to the anode of the light-emitting element 30, and the other may be electrically connected to the cathode of the light-emitting element 30. However, this disclosure is not limited to this, and the opposite may also be true.

[0098] Furthermore, electrodes 21 and 22 can be used to form an electric field in each sub-pixel PXn to align the light-emitting element 30. The light-emitting element 30 can be placed between the first electrode 21 and the second electrode 22 by means of an electric field formed on the first electrode 21 and the second electrode 22 (e.g., an electric field formed by the first electrode 21 and the second electrode 22 such that the electric field extends between and around the first electrode 21 and the second electrode 22). The light-emitting element 30 of the display device 10 can be sprayed onto the electrodes 21 and 22 by an inkjet printing process. When ink containing the light-emitting element 30 is sprayed onto the electrodes 21 and 22, an alignment signal is transmitted to the electrodes 21 and 22 to generate an electric field. The light-emitting element 30 dispersed in the ink can be aligned on the electrodes 21 and 22 by dielectric force due to the electric field generated on (or by) the electrodes 21 and 22.

[0099] The first insulating layer PAS1 is on the first planarization layer 19. The first insulating layer PAS1 can cover the first block BNL1 and the first electrode 21 and the second electrode 22. The first insulating layer PAS1 can protect the first electrode 21 and the second electrode 22, while insulating the first electrode 21 and the second electrode 22 from each other (e.g., electrically). In addition, the first insulating layer PAS1 can prevent or reduce direct contact between the light-emitting element 30 on the first insulating layer PAS1 and other components, thereby preventing or reducing damage to the light-emitting element 30.

[0100] In one embodiment, the first insulating layer PAS1 may include an opening OP that partially exposes the first electrode 21 and the second electrode 22. Each opening OP may partially expose a portion of the electrodes 21 and 22 on the upper surface of the first block BNL1. A portion of each of the contact electrodes CNE1 and CNE2 may contact (e.g., physically contact) the electrode 21 or 22 exposed through the opening OP.

[0101] The first insulating layer PAS1 may be stepped, such that a portion of the upper surface of the first insulating layer PAS1 is recessed between the first electrode 21 and the second electrode 22. For example, because the first insulating layer PAS1 covers the first electrode 21 and the second electrode 22, the upper surface of the first insulating layer PAS1 may be stepped according to the shape of the electrodes 21 and 22 below the first insulating layer PAS1. However, this disclosure is not limited thereto.

[0102] The second block BNL2 may be on the first insulating layer PAS1. The second block BNL2 may include portions extending in the first direction D1 and the second direction D2 to form a grid pattern over the entire display area DPA in a plan view. The second block BNL2 may be at the boundary of each sub-pixel PXn to separate adjacent sub-pixels PXn.

[0103] Furthermore, the second block BNL2 may surround the emission region EMA and the cut region CBA in each sub-pixel PXn to separate the sub-pixels PXn from each other (e.g., physically separate them). The first electrode 21 and the second electrode 22 may extend in the second direction D2 across the portion of the second block BNL2 that extends in the first direction D1. In the portion of the second block BNL2 that extends in the second direction D2, the segments between the emission regions EMA may have a larger width than the segments between the cut regions CBA. Therefore, the gap between the cut regions CBA may be smaller than the gap between the emission regions EMA.

[0104] The second block BNL2 can be formed to have a greater height than the first block BNL1. During the inkjet printing process in the manufacturing process of the display device 10, the second block BNL2 can prevent or reduce ink spillage to adjacent sub-pixels PXn. Therefore, the second block BNL2 can separate the ink in which different light-emitting elements 30 are dispersed for different sub-pixels PXn, so that the ink does not mix with each other. Like the first block BNL1, the second block BNL2 can contain polyimide (PI), but this disclosure is not limited thereto.

[0105] The light-emitting element 30 may be on the first insulating layer PAS1. The light-emitting elements 30 may be spaced apart from each other along a second direction D2 in which each electrode 21 or 22 extends, and may be aligned substantially parallel to each other. The light-emitting element 30 may extend in one direction, and the direction in which each electrode 21 or 22 extends and the direction in which the light-emitting element 30 extends may be substantially perpendicular to each other. However, this disclosure is not limited thereto, and the light-emitting element 30 may also extend in a direction that is not perpendicular to the direction in which each electrode 21 or 22 extends, but rather at an angle.

[0106] The light-emitting elements 30 in different sub-pixels PXn may include light-emitting layers 36 containing different materials (see...). Figure 4 The first, second, and third colors of light can be emitted by the first sub-pixel PX1, the second sub-pixel PX2, and the third sub-pixel PX3, respectively. However, this disclosure is not limited thereto, and the sub-pixel PXn may also include light-emitting elements 30 of the same type (or kind) to emit light of substantially the same color.

[0107] The two ends of each light-emitting element 30 between the first blocks BNL1 can be on electrodes 21 and 22, respectively. The length of each light-emitting element 30 can be greater than the gap between the first electrode 21 and the second electrode 22, and the two ends of each light-emitting element 30 can be on the first electrode 21 and the second electrode 22, respectively. For example, the first end of each light-emitting element 30 can be on the first electrode 21, and the second end can be on the second electrode 22.

[0108] Each light-emitting element 30 may include multiple layers in a direction parallel to the upper surface of the substrate 11 or the first planarization layer 19. The direction in which each light-emitting element 30 extends may be parallel to the upper surface of the first planarization layer 19, and the multiple semiconductor layers included in each light-emitting element 30 may be arranged sequentially in a direction parallel (e.g., substantially parallel) to the upper surface of the first planarization layer 19. However, this disclosure is not limited thereto. When each light-emitting element 30 has a different structure, the semiconductor layers may be in a direction perpendicular (e.g., substantially perpendicular) to the upper surface of the first planarization layer 19.

[0109] Each light-emitting element 30 can have its two ends in contact (e.g., physical contact) with contact electrodes CNE1 and CNE2, respectively. For example, insulating layer 38 (see Figure 4 The semiconductor layer may not be formed on the end surface of each light-emitting element 30 in the direction in which each light-emitting element 30 extends, thereby partially exposing the semiconductor layer. The exposed semiconductor layer may contact (e.g., physically contact) contact electrodes CNE1 and CNE2. However, this disclosure is not limited thereto, and at least a portion of the insulating layer 38 of each light-emitting element 30 may also be removed to partially expose the side surfaces of both ends of the semiconductor layer. The exposed side surfaces of the semiconductor layer may directly contact (e.g., physically contact) contact electrodes CNE1 and CNE2.

[0110] The second insulating layer PAS2 may be partially on the light-emitting element 30. For example, the second insulating layer PAS2 on each light-emitting element 30 may have a width smaller than the length of the light-emitting element 30, so as to cover the light-emitting element 30 while exposing both ends of the light-emitting element 30. During the manufacturing process of the display device 10, the second insulating layer PAS2 may cover the light-emitting element 30, electrodes 21 and 22, and the first insulating layer PAS1 and then be removed to expose both ends of each light-emitting element 30. The second insulating layer PAS2 may extend on the first insulating layer PAS1 in a second direction D2 in a plan view to form a linear or island pattern in each sub-pixel PXn. During the manufacturing process of the display device 10, the second insulating layer PAS2 may protect the light-emitting element 30 while fixing the light-emitting element 30.

[0111] Contact electrodes CNE1 and CNE2, as well as the third insulating layer PAS3, can be on the second insulating layer PAS2.

[0112] Contact electrodes CNE1 and CNE2 may extend in one direction and may be located on electrodes 21 and 22, respectively. Contact electrodes CNE1 and CNE2 may comprise a first contact electrode CNE1 on the first electrode 21 and a second contact electrode CNE2 on the second electrode 22. Contact electrodes CNE1 and CNE2 may be spaced apart from each other and may face each other. For example, the first contact electrode CNE1 and the second contact electrode CNE2 may be located on the first electrode 21 and the second electrode 22, respectively, and may be spaced apart from each other in a first direction D1. Each contact electrode CNE1 or CNE2 may form a strip pattern in the emission region EMA of each sub-pixel PXn.

[0113] Each of contact electrodes CNE1 and CNE2 can contact (e.g., physically contact) the light-emitting element 30. The first contact electrode CNE1 can contact (e.g., physically contact) a first end of the light-emitting element 30, and the second contact electrode CNE2 can contact (e.g., physically contact) a second end of the light-emitting element 30. A semiconductor layer can be exposed on the two end surfaces of each light-emitting element 30 in the direction in which each light-emitting element 30 extends, and contact electrodes CNE1 and CNE2 can directly contact (e.g., physically contact) and are therefore electrically connected to the exposed semiconductor layer of each light-emitting element 30, respectively. The respective sides of contact electrodes CNE1 and CNE2 that contact (e.g., physically contact) the two ends of the light-emitting element 30 can be on the second insulating layer PAS2. Furthermore, the first contact electrode CNE1 can contact (e.g., physically contact) the first electrode 21 through an opening OP exposing a portion of the upper surface of the first electrode 21, and the second contact electrode CNE2 can contact (e.g., physically contact) the second electrode 22 through an opening OP exposing a portion of the upper surface of the second electrode 22.

[0114] The width of each contact electrode CNE1 or CNE2, measured in one direction, may be smaller than the width of each electrode 21 or 22, measured in that direction. Contact electrodes CNE1 and CNE2 may contact (e.g., physically contact) the first and second ends of each light-emitting element 30, while partially covering the upper surfaces of the first electrode 21 and the second electrode 22. However, this disclosure is not limited thereto, and contact electrodes CNE1 and CNE2 may also be formed wider than electrodes 21 and 22 to cover both sides of electrodes 21 and 22.

[0115] Contact electrodes CNE1 and CNE2 may contain a transparent conductive material. For example, contact electrodes CNE1 and CNE2 may contain ITO, IZO, ITZO, and / or aluminum (Al). Light emitted from the light-emitting element 30 can pass through contact electrodes CNE1 and CNE2 and travel toward electrodes 21 and 22, but this disclosure is not limited thereto.

[0116] Although the two contact electrodes CNE1 and CNE2 are shown in the accompanying drawings within a single sub-pixel PXn, this disclosure is not limited thereto. The number of contact electrodes CNE1 and CNE2 can vary depending on the number of electrodes 21 and 22 in each sub-pixel PXn.

[0117] A third insulating layer PAS3 covers the first contact electrode CNE1. The third insulating layer PAS3 may cover not only the first contact electrode CNE1, but also the side of the first contact electrode CNE1 positioned on top of the second insulating layer PAS2. For example, the third insulating layer PAS3 may cover both the first contact electrode CNE1 and the first insulating layer PAS1 on the first electrode 21. This arrangement can be achieved by placing the insulating material layer forming the third insulating layer PAS3 throughout the entire emitter region EMA, and then partially removing the insulating material layer to form the second contact electrode CNE2. In this process, the insulating material layer forming the third insulating layer PAS3 may be removed together with the insulating material layer forming the second insulating layer PAS2, and the side of the third insulating layer PAS3 may be aligned with the side of the second insulating layer PAS2. The side of the second contact electrode CNE2 may be on the third insulating layer PAS3 and may be insulated (e.g., electrically insulated) from the first contact electrode CNE1 by the third insulating layer PAS3 inserted between them.

[0118] The fourth insulating layer PAS4 can be applied to the entire display area DPA of the substrate 11. The fourth insulating layer PAS4 can protect the components on the substrate 11 from the external environment (e.g., from external moisture and / or air). However, the fourth insulating layer PAS4 can also be omitted.

[0119] Each of the first insulating layer PAS1, the second insulating layer PAS2, the third insulating layer PAS3, and the fourth insulating layer PAS4 described above may comprise inorganic and / or organic insulating materials. For example, each of the first insulating layer PAS1, the second insulating layer PAS2, the third insulating layer PAS3, and the fourth insulating layer PAS4 may comprise inorganic insulating materials, such as silicon oxide, silicon nitride, silicon nitride oxide, aluminum oxide (Al2O3), and / or aluminum nitride (AlN). In some embodiments, each of the first insulating layer PAS1, the second insulating layer PAS2, the third insulating layer PAS3, and the fourth insulating layer PAS4 may comprise organic insulating materials, such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, benzocyclobutene resin, cardo resin, siloxane resin, silsesquioxane resin, polymethyl methacrylate, polycarbonate, and / or polymethyl methacrylate-polycarbonate synthetic resin. However, this disclosure is not limited to this.

[0120] Figure 4 This is a schematic perspective view of the light-emitting element 30 according to the implementation scheme.

[0121] refer to Figure 4 The light-emitting element 30 can be a light-emitting diode. For example, the light-emitting element 30 can be an inorganic light-emitting diode with micrometer or nanometer dimensions and made of inorganic materials. When the two electrodes 21 and 22 face each other (see...) Figure 3 When an electric field is formed between or in a specific direction between the electrodes, an inorganic light-emitting diode can form two electrodes 21 and 22 of polarity (e.g., where opposite polarities are formed respectively) (see [reference]). Figure 3 Alignment between electrodes 21 and 22. The light-emitting element 30 can be aligned between electrodes 21 and 22 by forming an electric field on the two electrodes 21 and 22.

[0122] The light-emitting element 30 according to the embodiment can extend in one direction. The light-emitting element 30 can be formed as a cylinder, rod, wire, tube, etc. However, the shape of the light-emitting element 30 is not limited to this, and the light-emitting element 30 can also have various suitable shapes, including polygonal prisms (e.g., cubes, rectangular parallelepipeds, or hexagonal prisms) and shapes that extend in one direction and have a partially inclined outer surface. Multiple semiconductor layers included in the light-emitting element 30 can be arranged sequentially or stacked along one direction.

[0123] The light-emitting element 30 may include a semiconductor layer doped with impurities of any conductivity type (e.g., p-type or n-type). The semiconductor layer may receive electrical signals from an external power source and emit light of a set or specific wavelength band.

[0124] like Figure 4 As illustrated, the light-emitting element 30 may include a first semiconductor layer 31, a second semiconductor layer 32, a light-emitting layer 36, an electrode layer 37, and an insulating layer 38.

[0125] The first semiconductor layer 31 may be an n-type semiconductor layer. When the light-emitting element 30 emits light in the blue wavelength band, the first semiconductor layer 31 may contain Al x Ga y In (1-x-y) Semiconductor materials with a composition ratio of N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the semiconductor material contained in the first semiconductor layer 31 can be any one or more selected from n-type doped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The first semiconductor layer 31 can be doped with an n-type dopant, and the n-type dopant can be Si, Ge, Sn, etc. For example, the first semiconductor layer 31 can be n-GaN doped with n-type Si. The length of the first semiconductor layer 31 can be, but is not limited to, 1.5 μm to 5 μm.

[0126] The second semiconductor layer 32 is located on the light-emitting layer 36, which is further described herein. The second semiconductor layer 32 may be a p-type semiconductor layer. When the light-emitting element 30 emits light in the blue or green wavelength band, the second semiconductor layer 32 may contain Al x Ga y In (1-x-y) Semiconductor materials with a composition ratio of N (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the semiconductor material contained in the second semiconductor layer 32 can be any one or more selected from p-type doped AlGaInN, GaN, AlGaN, InGaN, AlN, and InN. The second semiconductor layer 32 can be doped with a p-type dopant, and the p-type dopant can be Mg, Zn, Ca, Se, Ba, etc. For example, the second semiconductor layer 32 can be p-GaN doped with p-type Mg. The length of the second semiconductor layer 32 can be, but is not limited to, 0.05 μm to 0.10 μm.

[0127] Although each of the first semiconductor layer 31 and the second semiconductor layer 32 is represented as a single layer in the accompanying drawings, this disclosure is not limited thereto. Each of the first semiconductor layer 31 and the second semiconductor layer 32 may also include additional layers. For example, each of the first semiconductor layer 31 and the second semiconductor layer 32 may further include a cladding layer or a tensile strain barrier reduction (TSBR) layer, depending on the material of the light-emitting layer 36.

[0128] The light-emitting layer 36 is located between the first semiconductor layer 31 and the second semiconductor layer 32. The light-emitting layer 36 may contain a material having a single quantum well structure or a multiple quantum well structure. When the light-emitting layer 36 contains a material having a multiple quantum well structure, it may have a structure in which multiple quantum layers and multiple well layers are alternately stacked. Based on the electrical signals received through the first semiconductor layer 31 and the second semiconductor layer 32, the light-emitting layer 36 may emit light through the recombination of electron-hole pairs. When the light-emitting layer 36 emits light in the blue wavelength band, it may contain materials such as AlGaN and / or AlGaInN. In some embodiments, when the light-emitting layer 36 has a multiple quantum well structure in which quantum layers and well layers are alternately stacked, the quantum layers may contain materials such as AlGaN and / or AlGaInN, and the well layers may contain materials such as GaN and / or AlInN. For example, the light-emitting layer 36 may contain AlGaInN as a quantum layer and AlInN as a well layer to emit blue light with a center wavelength band of 450 nm to 495 nm.

[0129] However, this disclosure is not limited to this, and the light-emitting layer 36 may also have a structure in which semiconductor materials with large band gap energies and semiconductor materials with small band gap energies are stacked alternately, or may contain different group 3 to group 5 semiconductor materials depending on the wavelength band of the emitted light. The light emitted from the light-emitting layer 36 is not limited to light in the blue wavelength band. In some cases, the light-emitting layer 36 may emit light in the red or green wavelength band. The length of the light-emitting layer 36 may be, but is not limited to, 0.05 μm to 0.10 μm.

[0130] The light emitted from the light-emitting layer 36 can radiate not only through the longitudinal outer surface of the light-emitting element 30, but also through the two end surfaces of the light-emitting element 30. The direction of the light emitted from the light-emitting layer 36 is not limited to one direction.

[0131] Figure 5 This is a schematic diagram of the light-emitting element 30' according to the implementation scheme.

[0132] refer to Figure 5 According to the embodiment, the light-emitting element 30' may further include a third semiconductor layer 33' between the first semiconductor layer 31' and the light-emitting layer 36', and a fourth semiconductor layer 34' and a fifth semiconductor layer 35' between the light-emitting layer 36' and the second semiconductor layer 32'. Figure 5 The light-emitting element 30' and Figure 4 The implementation differs in that it further includes multiple semiconductor layers 33' to 35' and multiple electrode layers 37a' and 37b', and the light-emitting layer 36' contains different elements. In the following text, no redundant descriptions will be repeated, and the main focus will be on the differences.

[0133] exist Figure 4 In the light-emitting element 30, the light-emitting layer 36 may contain nitrogen (N) to emit blue or green light. On the other hand, Figure 5 The light-emitting element 30' may be a semiconductor in which each of the light-emitting layer 36' and other semiconductor layers contains at least phosphorus (P). According to the embodiment, the light-emitting element 30' can emit red light with a center wavelength band of 620 nm to 750 nm. However, the center wavelength band of red light is not limited to the above range and can be understood to include all wavelengths that can be considered red within the field to which this disclosure pertains.

[0134] In some embodiments, the first semiconductor layer 31' may be an n-type semiconductor layer and may contain In x Al y Ga (1-x-y) The semiconductor material has a composition ratio of P (0≤x≤1, 0≤y≤1, 0≤x+y≤1). The first semiconductor layer 31' can be any one or more of n-type doped InAlGaP, GaP, AlGaP, InGaP, AlIP, and InP. For example, the first semiconductor layer 31' can be n-AlGaInP doped with n-type Si.

[0135] The second semiconductor layer 32' may be a p-type semiconductor layer, and may contain In... x Al y Ga (1-x-y) The semiconductor material has a composition ratio of P (0≤x≤1, 0≤y≤1, 0≤x+y≤1). The second semiconductor layer 32' can be any one or more of p-type doped InAlGaP, GaP, AlGaNP, InGaP, AIP, and InP. For example, the second semiconductor layer 32' can be p-GaP doped with p-type Mg.

[0136] The light-emitting layer 36' can be located between the first semiconductor layer 31' and the second semiconductor layer 32'. The light-emitting layer 36' can emit light of a set or specific wavelength band by comprising a material having a single quantum well structure or a multiple quantum well structure. When the light-emitting layer 36' has a multiple quantum well structure in which quantum layers and well layers are stacked alternately, the quantum layers can comprise materials such as AlGaP and / or AlInGaP, and the well layers can comprise materials such as GaP and / or AlInP. For example, the light-emitting layer 36' can comprise AlGaInP as a quantum layer and AlInP as a well layer to emit blue light with a center wavelength band of 620 nm to 750 nm.

[0137] Figure 5The light-emitting element 30' may include a cladding layer adjacent to the light-emitting layer 36'. As illustrated in the figures, the third semiconductor layer 33' and the fourth semiconductor layer 34' below and above the light-emitting layer 36' and between the first semiconductor layer 31' and the second semiconductor layer 32' may be cladding layers.

[0138] The third semiconductor layer 33' may be located between the first semiconductor layer 31' and the light-emitting layer 36'. The third semiconductor layer 33' may be an n-type semiconductor layer like the first semiconductor layer 31', and may contain In... x Al y Ga (1-x-y) Semiconductor materials with a composition ratio of P (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the first semiconductor layer 31' may be n-AlGaInP, and the third semiconductor layer 33' may be n-AlInP. However, this disclosure is not limited thereto.

[0139] The fourth semiconductor layer 34' may be located between the light-emitting layer 36' and the second semiconductor layer 32'. The fourth semiconductor layer 34' may be a p-type semiconductor layer, similar to the second semiconductor layer 32', and may contain elements with In... x Al y Ga (1-x-y) Semiconductor materials with a composition ratio of P (0≤x≤1, 0≤y≤1, 0≤x+y≤1). For example, the second semiconductor layer 32' can be p-GaP, and the fourth semiconductor layer 34' can be p-AlInP.

[0140] The fifth semiconductor layer 35' may be located between the fourth semiconductor layer 34' and the second semiconductor layer 32'. The fifth semiconductor layer 35' may be a p-type doped semiconductor layer, just like the second semiconductor layer 32' and the fourth semiconductor layer 34'. In some embodiments, the fifth semiconductor layer 35' may reduce the difference in lattice constant between the fourth semiconductor layer 34' and the second semiconductor layer 32'. The fifth semiconductor layer 35' may be a TSBR layer. For example, the fifth semiconductor layer 35' may contain, but is not limited to, p-GaInP, p-AlInP, and / or p-AlGaInP. Furthermore, the lengths of the third semiconductor layer 33', the fourth semiconductor layer 34', and the fifth semiconductor layer 35' may be, but are not limited to, 0.08 μm to 0.25 μm.

[0141] The first electrode layer 37a' and the second electrode layer 37b' may be located on the first semiconductor layer 31' and the second semiconductor layer 32', respectively. The first electrode layer 37a' may be located on the lower surface of the first semiconductor layer 31', and the second electrode layer 37b' may be located on the upper surface of the second semiconductor layer 32'. However, this disclosure is not limited thereto, and at least one of the first electrode layer 37a' and the second electrode layer 37b' may be omitted. For example, the first electrode layer 37a' may not be located on the lower surface of the first semiconductor layer 31', and only one second electrode layer 37b' may be located on the upper surface of the second semiconductor layer 32'.

[0142] See again Figure 4 Electrode layer 37 can be an ohmic contact electrode. However, this disclosure is not limited thereto, and electrode layer 37 can also be a Schottky contact electrode (e.g., an electrode having a junction formed of a semiconductor and a metal). The light-emitting element 30 may include at least one electrode layer 37. Although in Figure 4 The light-emitting element 30 includes an electrode layer 37, but this disclosure is not limited thereto. In some cases, the light-emitting element 30 may include additional electrode layers 37, or the electrode layer 37 may be omitted. Even if the light-emitting element 30 includes different numbers of electrode layers 37 or further includes other structures, the following description of the light-emitting element 30 can be applied in the same way.

[0143] When the light-emitting element 30 is electrically connected to an electrode or contact electrode in the display device 10 according to the embodiment, the electrode layer 37 can reduce the resistance between the light-emitting element 30 and the electrode and / or contact electrode. The electrode layer 37 may contain a conductive metal (e.g., a conductive metal). For example, the electrode layer 37 may contain at least one selected from aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). Furthermore, the electrode layer 37 may contain an n-type or p-type doped semiconductor material. The electrode layer 37 may contain the same material or different materials, but this disclosure is not limited thereto.

[0144] An insulating layer 38 surrounds the outer surfaces of the plurality of semiconductor layers and the plurality of electrode layers described above. For example, the insulating layer 38 may surround at least the outer surface of the light-emitting layer 36 and extend in the direction in which the light-emitting element 30 extends. The insulating layer 38 may protect the above-described components. For example, the insulating layer 38 may surround the side surfaces of the above-described components and may expose the two ends of the light-emitting element 30 in the longitudinal direction.

[0145] In the accompanying drawings, the insulating layer 38 extends in the longitudinal direction of the light-emitting element 30 to cover the side surface from the first semiconductor layer 31 to the side surface of the electrode layer 37. However, this disclosure is not limited to this, and the insulating layer 38 may also cover only some of the semiconductor layers and the outer surface of the light-emitting layer 36, or it may cover only a portion of the outer surface of the electrode layer 37 to partially expose the outer surface of the electrode layer 37. Furthermore, the upper surface of the insulating layer 38 may have a circular cross-section in the region adjacent to at least one end of the light-emitting element 30.

[0146] The thickness of the insulating layer 38 can be, but is not limited to, 10 nm to 1.0 μm. The thickness of the insulating layer 38 can be, for example, about 40 nm.

[0147] The insulating layer 38 may comprise a material with insulating properties (e.g., electrical insulating properties), such as silicon oxide, silicon nitride, silicon nitride oxide, aluminum nitride (AlN), and / or aluminum oxide (Al2O3). Therefore, it can prevent or reduce the likelihood or extent of electrical short circuits that may occur when the light-emitting layer 36 directly contacts the electrodes transmitting electrical signals to the light-emitting element 30. Furthermore, because the insulating layer 38 protects the outer surface of the light-emitting element 30, including the light-emitting layer 36, it can prevent or reduce a decrease in luminous efficiency.

[0148] Furthermore, the outer surface of the insulating layer 38 can be treated. The light-emitting elements 30, dispersed in a set or predetermined ink, can be sprayed onto the electrodes and then aligned. Here, the surface of the insulating layer 38 can be treated hydrophobically or hydrophilically (e.g., treated to make the surface of the insulating layer 38 hydrophobic or hydrophilic) so that the light-emitting elements 30 remain separated from each other in the ink and do not agglomerate with other adjacent light-emitting elements 30. For example, the outer surface of the insulating layer 38 can be treated with materials such as stearic acid and / or 2,3-naphthalenedicarboxylic acid.

[0149] The length h of the light-emitting element 30 can be from 1 μm to 10 μm or from 2 μm to 6 μm, and can be, for example, from 3 μm to 5 μm. Furthermore, the diameter of the light-emitting element 30 can be from 30 nm to 700 nm, and the aspect ratio of the light-emitting element 30 can be from 1.2 to 100. However, this disclosure is not limited thereto, and the plurality of light-emitting elements 30 included in the display device 10 can also have different diameters depending on the composition of the light-emitting layer 36. The diameter of the light-emitting element 30 can be, for example, about 500 nm.

[0150] The shape and material of the light-emitting element 30 are not limited to Figure 4 and Figure 5 Those. In some embodiments, the light-emitting element 30 may include additional layers or may have different shapes.

[0151] The apparatus for inspecting defects in light-emitting elements to manufacture the display device 10 according to the above-described embodiment will now be further described.

[0152] Figure 6 This is a schematic perspective view of a device 200 for inspecting light-emitting elements according to an implementation plan. Figure 7 This is a schematic perspective view of the alignment unit 220 of the device 200 for inspecting light-emitting elements according to the implementation scheme. Figure 8 This is a schematic perspective view of the stacking unit 240 of the device 200 for inspecting light-emitting elements according to the implementation scheme. Figure 9 This is a schematic perspective view illustrating the opening and closing operations of the filter baffles 245 and 246 of the stacking unit 240 according to the embodiment. Figure 10 and Figure 11 This is a schematic perspective view illustrating the operation of the inspection electrodes 242 and 243 of the stacking unit 240 according to the embodiment.

[0153] In the accompanying drawings, a first direction D1, a second direction D2, and a third direction D3 are defined. The first direction D1 and the second direction D2 are positioned in a plane and are orthogonal to each other (e.g., substantially orthogonal), and the third direction D3 is perpendicular to each of the first direction D1 and the second direction D2 (e.g., substantially perpendicular).

[0154] Figure 6 This illustration shows the configuration of a device 200 for inspecting light-emitting elements according to an embodiment. The structure and arrangement of the device 200 for inspecting light-emitting elements are not limited to... Figure 6 Those. The device 200 for inspecting light-emitting elements may also include additional components and have the same... Figure 6 The structures are different.

[0155] refer to Figure 6 The apparatus 200 for inspecting light-emitting elements may include a flow path unit 210, an alignment unit 220 to which the flow path extends from at least a portion of the flow path unit 210, a stacking unit 240 at the end of the flow path unit 210, and a plurality of alignment electrodes 251 and 252 on the outer surface of the flow path unit 210. The apparatus 200 for inspecting light-emitting elements can align and inspect defects in the light-emitting element 30.

[0156] The flow path unit 210 can be shaped like a tube extending in the third direction D3 and can include a flow path 211 along which the solution SOL containing the light-emitting element 30 can move, but this disclosure is not limited thereto. In an embodiment, the width of the flow path 211 in the first direction D1 can be greater than the length of the minor axis of each light-emitting element 30 and less than the length of the major axis of each light-emitting element 30. The width of the flow path 211 in the second direction D2 can be greater than the lengths of the major and minor axes of each light-emitting element 30. For example, the width of the flow path 211 in each of the first direction D1 and the second direction D2 can be large enough to allow the solution SOL containing the light-emitting element 30 to move. Therefore, the light-emitting element 30 can move along the flow path 211 with its longitudinal direction arranged in the second direction D2.

[0157] In one embodiment, the upper end of the flow path unit 210 may have a rectangular plane in which two sides extending in the second direction D2 are longer than the two sides extending in the first direction D1. Furthermore, the flow path unit 210 may be shaped like a rectangular parallelepiped extending in the third direction D3.

[0158] The flow path unit 210 may be made of an insulating material (e.g., an electrically insulating material). The flow path unit 210 may be made of an insulating material in order to apply an electric field to the flow path unit 210 by means of the alignment electrodes 251 and 252, which are further described herein. The flow path unit 210 may be made of, for example, ceramics and / or polymers.

[0159] The flow path unit 210 may include an inlet 212 at an upper end and an outlet 213 at a lower end. The inlet 212 may be an inlet through which solution SOL is injected into the flow path 211, and the outlet 213 may be an outlet through which solution SOL passing through the flow path 211 is discharged to the outside. Each of the inlet 212 and outlet 213 may have a rectangular shape, such that the longitudinal direction of the light-emitting element 30 mixed in the solution SOL can be arranged in the second direction D2. Similarly, the flow path 211 may have a rectangular planar shape, such that the longitudinal direction of the light-emitting element 30 mixed in the solution SOL can be arranged in the second direction D2.

[0160] Alignment unit 220 may be an area reached by flow path 211 extending from at least a portion of flow path unit 210. Alignment unit 220 may serve as a space in which light-emitting element 30 is rotated and realigned. Alignment unit 220 may include a first alignment region 220a and a second alignment region 220b. The first alignment region 220a and the second alignment region 220b may be spaced apart from each other in a third direction D3.

[0161] Each of the first alignment region 220a and the second alignment region 220b may include a semi-cylindrical shape protruding from the flow path unit 210 in the first direction D1 and a semi-cylindrical shape protruding from the flow path unit 210 in the direction opposite to the first direction D1. Therefore, each of the first alignment region 220a and the second alignment region 220b may have a cylindrical shape as a whole.

[0162] The width W1 of each of the first alignment region 220a and the second alignment region 220b in the second direction D2 can be substantially equal to the width W2 of the flow path unit 210 in the second direction D2. Conversely, the width W3 of each of the first alignment region 220a and the second alignment region 220b in the first direction D1 can be greater than the width W4 of the flow path unit 210 in the first direction D1. The width W3 of each of the first alignment region 220a and the second alignment region 220b in the first direction D1 can be greater than the major axis of each light-emitting element 30. In an embodiment, the diameter of each of the first alignment region 220a and the second alignment region 220b in the first direction D1 or the second direction D2 can be greater than the major axis of each light-emitting element 30. As further described herein, in each of the first alignment region 220a and the second alignment region 220b of the alignment unit 220, the light-emitting element 30 can be rotated by an electric field. Therefore, each of the first alignment region 220a and the second alignment region 220b can provide space in which the light-emitting element 30 can rotate.

[0163] In this embodiment, the first alignment region 220a can be used as the region for primary alignment of the light-emitting element 30, and the second alignment region 220b can be used as the region for secondary alignment of the light-emitting element 30. For example, a light-emitting element 30 that is not aligned in the first alignment region 220a can be aligned in the second alignment region 220b. In the current embodiment, the alignment unit 220 includes two alignment regions, such as the first alignment region 220a and the second alignment region 220b, but this disclosure is not limited thereto, and the alignment unit 220 may also include three or more alignment regions.

[0164] Alignment electrodes 251 and 252 may be located on two sides of the outer surface of the flow path unit 210, respectively. Alignment electrodes 251 and 252 may include a first alignment electrode 251 and a second alignment electrode 252. The first alignment electrode 251 may be located on one side of the outer surface of the flow path unit 210, and the second alignment electrode 252 may be located on the other side of the outer surface of the flow path unit 210. The first alignment electrode 251 and the second alignment electrode 252 may be positioned side-by-side facing each other. For example, the first alignment electrode 251 may be parallel (e.g., substantially parallel) to a first direction D1 of the flow path unit 210 and may contact (e.g., physically contact) a surface of the flow path unit 210 extending in a third direction D3, and the second alignment electrode 252 may be parallel (e.g., substantially parallel) to the first direction D1 of the flow path unit 210 and may contact (e.g., physically contact) another surface of the flow path unit 210 extending in a third direction D3.

[0165] The alignment unit 220 described above can align the light-emitting element 30. The operation of aligning the light-emitting element 30 in the first alignment region 220a will be further described below as a representative example, and the above description will be used as a further example. Figure 4 The light-emitting element 30 shown in the figure is an example of the structure of each light-emitting element 30.

[0166] refer to Figure 7 The light-emitting element 30 can be moved to the first alignment region 220a via the flow path unit 210. Because the first alignment region 220a provides space larger than the major and minor axes of the light-emitting element 30, the light-emitting element 30 can be easily rotated. The first alignment electrode 251 and the second alignment electrode 252 can be located outside the two sides of the first alignment region 220a.

[0167] The light-emitting elements 30 can be moved to the first alignment region 220a in a state in which they are mixed in the solution SOL. Electrical signals can be transmitted to each of the first alignment electrode 251 and the second alignment electrode 252.

[0168] For example, when an electrical signal (i.e., current) is transmitted to the first alignment electrode 251 and the second alignment electrode 252, an electric field can be generated between the first alignment electrode 251 and the second alignment electrode 252. In the current embodiment, a direct current (DC) signal can be transmitted to the first alignment electrode 251 and the second alignment electrode 252. When the DC signal is transmitted to the first alignment electrode 251 and the second alignment electrode 252, the light-emitting element 30 dispersed in the solution SOL can generate a dipole moment in response to the electric field. The light-emitting element 30 having a dipole moment can generate a torque T in response to the generated electric field. DEPTherefore, the light-emitting element 30 can rotate. Furthermore, the light-emitting element 30 can withstand the dielectric force F through an electric field. DEP . Exposed to dielectrophoretic force F DEP The light-emitting element 30 can be moved toward a position where the electric field intensity is relatively large. Therefore, the two ends of each light-emitting element 30 can be rotated toward the first alignment electrode 251 and the second alignment electrode 252, respectively.

[0169] Because the device 200 for inspecting light-emitting elements according to the embodiment includes multiple alignment regions 220a and 220b, the light-emitting elements 30 passing through the alignment regions 220a and 220b can all be aligned in one direction. For example, as Figure 7 As illustrated, the light-emitting layer 36 of each light-emitting element 30 may be adjacent to the first alignment electrode 251. In some embodiments, the light-emitting layer 36 of each light-emitting element 30 may be adjacent to the second alignment electrode 252.

[0170] Stacking unit 240 can extend from flow path unit 210 and is located at the end of flow path unit 210.

[0171] refer to Figures 8 to 11 The stacking unit 240 may include a storage component 241 for temporarily storing the light-emitting element 30, a plurality of inspection electrodes 242 and 243 on two sides of the storage component 241, filter baffles 245 and 246 at the upper and lower ends of the storage component 241, and an electrode moving component 247 for moving the inspection electrodes 242 and 243.

[0172] The storage component 241 can be formed by extending the flow path unit 210. The storage component 241 can be a space in which the light-emitting element 30 is temporarily stored. The shape of the storage component 241 can be substantially the same as the shape of the flow path 211 of the flow path unit 210.

[0173] The inspection electrodes 242 and 243 may be located on two sides within the storage component 241, respectively. The inspection electrodes 242 and 243 may include a first inspection electrode 242 and a second inspection electrode 243. The first inspection electrode 242 may be located on one side of the storage component 241, and the second inspection electrode 243 may be located on another side of the storage component 241. The first inspection electrode 242 and the second inspection electrode 243 may be positioned side-by-side facing each other. For example, the first inspection electrode 242 may be adjacent to one side of the storage component 241 that is parallel (e.g., substantially parallel) to a first direction D1 of the storage component 241, and the second inspection electrode 243 may be adjacent to another side of the storage component 241 that is parallel (e.g., substantially parallel) to the first direction D1 of the storage component 241 and faces the aforementioned side. The first inspection electrode 242 and the second inspection electrode 243 may be spaced apart from the first alignment electrode 251 and the second alignment electrode 252 described above, respectively.

[0174] Filters 245 and 246 may be located at the upper and lower ends of the storage component 241, respectively. Filters 245 and 246 can filter out the light-emitting element 30 from a solution SOL in which the light-emitting element 30 is mixed, while allowing the solvent to flow, thus storing the light-emitting element 30 in the storage component 241. Filters 245 and 246 may each include a plurality of openings to allow solvent to pass through. Each of the openings may be smaller than each of the light-emitting elements 30. For example, filters 245 and 246 may have a mesh shape that allows solvent to pass through filters 245 and 246 and filter out the light-emitting element 30. However, the shape of each of filters 245 and 246 is not limited to the above examples, and filters 245 and 246 may have any suitable structure, as long as they can filter out the light-emitting element 30.

[0175] refer to Figure 8 and Figure 9 The filter baffles 245 and 246 may include a first filter baffle 245 and a second filter baffle 246. The first filter baffle 245 may be on the upper side of the storage component 241, and the second filter baffle 246 may be on the lower side of the storage component 241. When it is necessary to store the light-emitting element 30, the filter baffles 245 and 246 may be opened and closed to filter out the light-emitting element 30. For example, when a solution SOL in which the light-emitting element 30 is mixed flows through the flow path unit 210 to the stacking unit 240, if the second filter baffle 246 blocks the lower side of the storage component 241, the light-emitting element 30 is filtered out and stacked on the second filter baffle 246, and the solution passes through the second filter baffle 246. Furthermore, if the first filter baffle 245 blocks the upper side of the storage component 241 after a set or predetermined time interval, the light-emitting element 30 may be prevented from entering the storage component 241.

[0176] exist Figure 8 and Figure 9 In the present invention, an example has been described of an opening / closing operation in which each of the filter baffles 245 or 246 has a side fixed to the storage component 241 and opens downward. However, the present disclosure is not limited thereto, and the filter baffles 245 and 246 may also be inserted from outside the storage component 241.

[0177] Electrode moving component 247 may be external to storage component 241 and adjacent to first inspection electrode 242 and second inspection electrode 243, respectively. Electrode moving component 247 may horizontally move the first inspection electrode 242 and second inspection electrode 243. Furthermore, electrode moving component 247 may be electrically connected to the first inspection electrode 242 and second inspection electrode 243, respectively, to apply current to them. Electrode moving component 247 may use, for example, a hydraulic cylinder to horizontally move inspection electrodes 242 and 243, but this disclosure is not limited thereto.

[0178] refer to Figure 10 and Figure 11 The stacking unit 240 described above can check the resistance and brightness of each light-emitting element 30 temporarily stored in the storage component 241. For example, when the light-emitting elements 30 are aligned in the storage component 241, the first inspection electrode 242 and the second inspection electrode 243 can be moved horizontally by the electrode moving component 247. The horizontally moving first inspection electrode 242 can contact (e.g., physically contact) one side of each light-emitting element 30, and the horizontally moving second inspection electrode 243 can contact (e.g., physically contact) the other side of each light-emitting element 30.

[0179] The first inspection electrode 242 and the second inspection electrode 243, which are in contact with two sides of each light-emitting element 30, can inspect the resistance and brightness of the light-emitting element 30. The light-emitting elements 30 can be inspected in units of multiple light-emitting elements 30 included in the storage component 241 of the stacking unit 240. For example, thirteen light-emitting elements 30 in the storage component 241 can form a unit, and the resistance and brightness of the light-emitting elements 30 in a unit can be measured. Using a reference resistance and brightness corresponding to a unit, light-emitting elements 30 whose resistance and brightness are equal to or greater than the reference resistance and brightness can be determined to be defect-free and thus usable in subsequent processes, while light-emitting elements 30 whose resistance and brightness are less than the reference resistance and brightness can be determined to be defective and thus discarded or reused.

[0180] A method for inspecting defects in the light-emitting element 30 by using the apparatus 200 for inspecting light-emitting elements described above will now be described.

[0181] Figure 12This is a flowchart illustrating a method for inspecting light-emitting elements. Figure 13 This is a schematic diagram illustrating a method for sorting the dimensions of light-emitting elements. Figure 14 This is a schematic diagram illustrating a method for using hybrid light-emitting elements. Figure 15 This is a schematic diagram of acoustic flow. See also: Figures 7 to 11 The following description is provided.

[0182] refer to Figure 12 The method for inspecting light-emitting elements according to the embodiment may include: preparing a solution in which light-emitting elements and solvents are mixed (operation S100), sorting the size (e.g., length) of light-emitting elements (operation S200), aligning and stacking light-emitting elements (operation S300), checking the resistance of light-emitting elements (operation S400), checking the brightness of light-emitting elements (operation S500), mixing defective light-emitting elements with the solution (operation S600), and obtaining defect-free light-emitting elements (operation S700).

[0183] According to the implementation scheme of the method, firstly, a solution SOL in which a light-emitting element and a solvent are mixed is prepared. This can be done as described above. Figure 4 or Figure 5 The diagram illustrates the construction of a light-emitting element. The light-emitting element can have various suitable lengths. The solution SOL is primarily composed of a solvent and can contain the light-emitting element in a set or predetermined amount (e.g., quantity).

[0184] Then, refer to Figure 12 and Figure 13 The size (e.g., length) of the light-emitting elements can be sorted (operation S200). As described above, the light-emitting elements mixed in the solution SOL can have various suitable sizes (e.g., lengths). The current operation is the process of sorting out light-emitting elements having sizes (e.g., lengths) suitable for use in a display device. In the embodiment, light-emitting elements 341 to 343 can have large and small sizes (e.g., lengths).

[0185] In an embodiment, the device may be configured to include two oscillators 310 and 320 and a first flow tube 330 between them, and surface acoustic wave technology may be used to sort the size (e.g., length) of light-emitting elements 341 to 343.

[0186] In surface acoustic wave (SAW) technology, two metal plates are alternately placed on a piezoelectric substrate, and an electrical signal is transmitted from one direction to generate surface acoustic waves on the piezoelectric substrate. The SAW waves can have a set or predetermined frequency and are sorted by the size (e.g., length) of the light-emitting element based on the principle that when a set or specific frequency is applied to an object, the object experiences a force according to its size (e.g., length or particle size). In SAW technology, SAW waves with a frequency greater than 1, K, can be emitted onto an object. Here, the wave number K can be given by:

[0187]

[0188] Where λ is the wavelength, f is the frequency, and d is the particle size.

[0189] The two oscillators 310 and 320 may include a first oscillator 310 and a second oscillator 320. The first oscillator 310 may be located on a first side of the first flow tube 330, and two first oscillating plates 312 and 314 may be alternately positioned to oscillate surface acoustic waves at a set or predetermined frequency. The second oscillator 320 may be located on a second side of the first flow tube 330, and two second oscillating plates 322 and 324 may be alternately positioned to oscillate surface acoustic waves at a set or predetermined frequency. The first oscillator 310 and the second oscillator 320 may be spaced apart from each other in the longitudinal direction of the first flow tube 330. For example, the first oscillator 310 may be located on the upper side of the first flow tube 330, and the second oscillator 320 may be located on the lower side of the first flow tube 330.

[0190] In some embodiments, to sort the lengths of light-emitting elements 341 to 343, a solution of SOL containing light-emitting elements 341 to 343 is injected into the first flow tube 330. By sending an electrical signal to the second oscillator 320, surface acoustic waves of a set or specific frequency are emitted into the first flow tube 330 to sort the first light-emitting elements 341 with a set or predetermined length. For example, when surface acoustic waves with a frequency of 135 MHz oscillate at a power of 0.85 W, the first light-emitting element 341 with a length of 5 μm in the first flow tube 330 is subjected to force and thus moves to the first side of the first flow tube 330.

[0191] Then, by sending an electrical signal to the first oscillator 310, surface acoustic waves of a set or specific frequency are emitted into the first flow tube 330 to sort out the second light-emitting elements 342 with a set or predetermined length. For example, when a surface acoustic wave with a frequency of 170 MHz oscillates with a power of 0.85 W, the second light-emitting element 342 with a length of 4 μm in the first flow tube 330 is subjected to force and thus moves to the second side of the first flow tube 330. Furthermore, the third light-emitting element 343, which is not affected by the surface acoustic waves of the set or predetermined frequency of each of the first oscillator 310 and the second oscillator 320, still moves along the first flow tube 330 (e.g., it is not moved or is substantially not moved by the surface acoustic waves).

[0192] The first discharge pipe 332 and the second discharge pipe 334 can branch from the end of the first flow pipe 330 and are located at the end of the first flow pipe 330. The first discharge pipe 332 can cover from the center of the first flow pipe 330 to the first side, and the second discharge pipe 334 can cover the second side of the first flow pipe 330.

[0193] In one implementation, to sort out light-emitting elements with a length of 3.8 μm to 4.2 μm, an oscillator can oscillate surface acoustic waves with a frequency of 165 MHz to 175 MHz. Here, the frequency can have an energy of 50 W to 100 W.

[0194] The first light-emitting element 341 and the third light-emitting element 343, which move along the first side and center of the first flow tube 330, can move to the first discharge tube 332, and the second light-emitting element 342, which moves along the second side of the first flow tube 330, can move to the second discharge tube 334. Finally, the second light-emitting element 342 can be sorted out. The first light-emitting element 341 and the third light-emitting element 343 that have moved to the first discharge tube 332 can be discarded, and the second light-emitting element 342 that has moved to the second discharge tube 334 can be collected, mixed with solvent, and used in subsequent processes.

[0195] Although the implementation has described the use of two oscillators 310 and 320 to sort the second light-emitting element 342, this disclosure is not limited thereto. Light-emitting elements having a set or predetermined size (e.g., length) can also be sorted using a single oscillator.

[0196] Then, refer to Figure 6 , Figure 7 and Figure 12 It can align and stack light-emitting elements (operation S300).

[0197] The previously sorted light-emitting elements can be mixed with a solvent and prepared again as a solution (SOL). This SOL solution is then injected into... Figure 6In the inspection device 200 illustrated in the diagram, the solution SOL injected into the flow path unit 210 flows downward through the flow path 211 of the flow path unit 210.

[0198] The solution SOL flowing along flow path 211 can be aligned in alignment unit 220. For example, when an electrical signal (i.e., current) is transmitted to the first alignment electrode 251 and the second alignment electrode 252 in the first alignment region 220a, an electric field can be generated between the first alignment electrode 251 and the second alignment electrode 252. In the current embodiment, a DC signal can be transmitted to the first alignment electrode 251 and the second alignment electrode 252. When the DC signal is transmitted to the first alignment electrode 251 and the second alignment electrode 252, the light-emitting element 30 dispersed in the solution SOL can generate a dipole moment in response to the electric field. The light-emitting element 30 with a dipole moment can generate a torque T in response to the generated electric field. DEP Therefore, the light-emitting element 30 can rotate. Furthermore, the light-emitting element 30 can withstand the dielectric force F through an electric field. DEP . Exposed to dielectrophoretic force F DEP The light-emitting element 30 can be moved toward a position where the electric field intensity is relatively large. Therefore, the two ends of each light-emitting element 30 can rotate toward the first alignment electrode 251 and the second alignment electrode 252.

[0199] The solution SOL passing through the first alignment region 220a can flow continuously (e.g., substantially continuously) along the flow path 211 and can then be rotated and aligned again in the second alignment region 220b. In the second alignment region 220b, light-emitting elements that were not rotated and aligned in the first alignment region 220a can be rotated and aligned. For example, as... Figure 7 As illustrated, the light-emitting layer 36 of each light-emitting element 30 may be adjacent to the first alignment electrode 251.

[0200] Then, refer to Figures 8 to 12 It can check the resistance and brightness of the light-emitting element (operation S400 and operation S500).

[0201] The light-emitting element 30, aligned by rotation via the alignment unit 220, can move along the flow path unit 210 and then be stacked and stored in the stacking unit 240 at the end of the inspection device. When the solution SOL in which the light-emitting element 30 is mixed flows through the flow path unit 210 to the stacking unit 240, if the second filter baffle 246 blocks the lower side of the storage component 241, the light-emitting element 30 is filtered out and stacked on the second filter baffle 246, and the solution passes through the second filter baffle 246. Furthermore, if the first filter baffle 245 blocks the upper side of the storage component 241 after a set or predetermined time interval, the light-emitting element 30 can be prevented from entering the storage component 241.

[0202] Then, when the light-emitting elements 30 are stacked and aligned in the storage component 241 of the stacking unit 240, the first inspection electrode 242 and the second inspection electrode 243 can be moved horizontally by the electrode moving component 247. The horizontally moving first inspection electrode 242 can contact (e.g., physically contact) one side of each light-emitting element 30, and the horizontally moving second inspection electrode 243 can contact (e.g., physically contact) the other side of each light-emitting element 30. The first inspection electrode 242 and the second inspection electrode 243, which are in contact (e.g., physically contact) with both sides of each light-emitting element 30, can inspect the resistance and brightness of the light-emitting element 30. The light-emitting elements 30 can be inspected in units of multiple light-emitting elements 30 included in the storage component 241 of the stacking unit 240. Using a reference resistance and brightness corresponding to a unit, the light-emitting element 30 whose resistance and brightness are equal to or greater than the reference resistance and brightness can be determined to be defect-free. Therefore, defect-free light-emitting elements can be obtained (operation S700).

[0203] Furthermore, light-emitting elements 30 whose resistance and brightness are less than those of reference resistance and brightness can be identified as defective and collected, and then the next operation can be performed.

[0204] refer to Figure 12 , Figure 14 and Figure 15 The first solution 422 containing the defective light-emitting element 430 can be mixed with the second solution 424 containing the new light-emitting element 435. Because defect-free light-emitting elements can be mixed in the first solution 422 containing the defective light-emitting element 430, they can be reused.

[0205] In an embodiment, the device may be configured to include a third oscillator 410 and a second flow tube 420, and surface acoustic wave (SAW) technology may be used to mix a first solution 422 and a second solution 424. The third oscillator 410 may consist of a third oscillating plate 412 and a third oscillating plate 414 alternately positioned on a piezoelectric substrate. In SAW technology, when surface acoustic waves with a frequency less than 1 are emitted into a liquid, an acoustic flow is generated in the liquid. Figure 15 As illustrated, acoustic flow is the flow of a liquid rotating in a plane. For example, a third oscillator 410 emits surface acoustic waves with a frequency of less than 1 into a second flow tube 420, thereby generating acoustic flow in the second flow tube 420. Therefore, defective light-emitting elements 430 of the first solution 422 and new light-emitting elements 435 of the second solution 424 can be mixed. The resulting mixed solution 450 can then be moved to the initial process, i.e., the operation of sorting the size (e.g., length) of the light-emitting elements (operation S200), and then used.

[0206] As described above, in the method for inspecting light-emitting elements according to the embodiment, light-emitting elements with a desired length can be obtained by sorting them by size (e.g., length). Furthermore, in the method for inspecting light-emitting elements according to the embodiment, since defect-free light-emitting elements can be obtained, defects in the display device can be prevented (or the likelihood or extent of such defects can be reduced).

[0207] A method for manufacturing a display device using defect-free light-emitting elements obtained by inspecting the light-emitting elements will now be further described.

[0208] Figure 16 This is a flowchart illustrating a method for manufacturing a display device according to an embodiment. Figure 17 This is a cross-sectional view illustrating a portion of the process of manufacturing a display device according to an embodiment. Figure 18 This is a plan view of a subpixel during a stage of the manufacturing process of a display device according to the implementation scheme. Figure 19 This is a cross-sectional view illustrating a portion of the process of manufacturing a display device according to an embodiment. Figure 20 This is a plan view of a subpixel during a stage of the manufacturing process of a display device according to the implementation scheme. Figure 21 This is a cross-sectional view illustrating a portion of the process of manufacturing a display device according to an embodiment. Figure 22 This is a plan view of a subpixel during a stage of the manufacturing process of a display device according to the implementation scheme.

[0209] refer to Figure 16 The method for manufacturing a display device according to the embodiment may include: inspecting the light-emitting element and preparing ink (operation S1000), coating the ink on a target substrate including a plurality of electrodes (operation S1100), aligning the light-emitting element (operation S1200), and forming a plurality of contact electrodes (operation S1300).

[0210] refer to Figure 12 and Figure 16 The light-emitting elements are inspected, and ink is prepared as a solution containing the determined defect-free light-emitting elements (operation S1000). (Referring to the above...) Figures 12 to 15 The operation has already been described, so its repetitive description will not be repeated here.

[0211] Then, refer to Figures 16 to 18Ink is coated onto a target substrate SUB comprising multiple electrodes (operation S1100). First, the target substrate SUB is prepared. In some embodiments, the target substrate SUB may include multiple sub-pixels, which include circuit elements composed of multiple conductive layers and multiple insulating layers. For ease of description, the target substrate SUB will be illustrated and described below as including the above elements.

[0212] Then, a plurality of first blocks BNL1 spaced apart from each other are formed on the target substrate SUB. The first blocks BNL1 can protrude from the upper surface of the target substrate SUB. The arrangement of the first blocks BNL1 is the same as described above. In addition, first contact holes CT1 and second contact holes CT2 are formed on the target substrate SUB, exposing the circuit elements formed in the target substrate SUB.

[0213] Then, a first electrode layer 21' and a second electrode layer 22' are formed on the first block BNL1. The first electrode layer 21' and the second electrode layer 22' extend in the second direction D2. During the manufacturing process of the display device 10, the first electrode layer 21' and the second electrode layer 22' may extend in the second direction D2 to other sub-pixels. After the light-emitting element 30 is placed in a subsequent process, the first electrode layer 21' and the second electrode layer 22' may be cut in the cutting region CBA of each sub-pixel PXn to form the first electrode 21 and the second electrode 22.

[0214] Then, refer to Figure 19 and Figure 20 A first insulating material layer 51' is formed to cover the first electrode layer 21' and the second electrode layer 22', and a second block BNL2 is formed on the first insulating material layer 51' to surround the emitter region EMA and cut region CBA of each sub-pixel PXn. The first insulating material layer 51' may be entirely on the target substrate SUB and may cover the electrode layers 21' and 22'. The first insulating material layer 51' may be partially removed in a subsequent process to expose the upper surfaces of the electrode layers 21' and 22', thereby forming the first insulating layer PAS1. The second block BNL2 may be positioned to surround each sub-pixel PXn to separate them from each other, while also separating the emitter region EMA and cut region CBA.

[0215] Then, refer to Figure 16 , Figure 21 and Figure 22Align the light-emitting elements (operation S1200). For example, place multiple light-emitting elements 30 between first blocks BNL1. The light-emitting elements 30 can be placed on a first insulating material layer 51' such that the two ends of each light-emitting element 30 are located on a first electrode layer 21' and a second electrode layer 22', respectively. The light-emitting elements 30 can be sprayed onto a target substrate SUB in a state where the light-emitting elements 30 are dispersed in ink IN. In an exemplary embodiment, the light-emitting elements 30 can be dispersed in ink IN containing solvent and can be sprayed onto the target substrate SUB during the printing process using the inkjet printing apparatus described above. The ink IN sprayed by the inkjet printing apparatus can be deposited in the area surrounded by a second block BNL2. The second block BNL2 can prevent or reduce ink IN overflow to other sub-pixels PXn.

[0216] Then, when ink IN containing the light-emitting element 30 is sprayed, an electrical signal is transmitted to each electrode layer 21' or 22', thereby placing the light-emitting element 30 on the first insulating material layer 51'.

[0217] For example, when an electrical signal (i.e., current) is transmitted to electrode layers 21' and 22', an electric field can be generated on electrode layers 21' and 22'. When a DC signal is transmitted to either electrode layer 21' or 22', the light-emitting element 30 dispersed in the ink IN generates a dipole moment. The light-emitting element 30 with a dipole moment generates a torque T in response to the generated electric field. DEP Therefore, the light-emitting element 30 is aligned. Furthermore, the light-emitting element 30 can withstand the dielectric force F through an electric field. DEP . Exposed to dielectrophoretic force F DEP The light-emitting element 30 can be moved toward a position where the electric field intensity is high. Therefore, the two ends of each light-emitting element 30 can be located on the electrode layers 21' and 22'.

[0218] like Figure 21 and Figure 22 As illustrated, light-emitting elements 30 dispersed in ink IN are positioned such that one end of each light-emitting element 30 is located on the first electrode layer 21' and the other end is located on the second electrode 22'. Then, the solvent is removed from the ink IN sprayed onto the target substrate SUB. Therefore, the position of the light-emitting elements 30 can be fixed.

[0219] Then, refer to Figure 2 , Figure 3 and Figure 16Multiple contact electrodes are formed (operation S1300). For example, a first insulating layer PAS1 is formed by partially removing the first insulating material layer 51' to expose the upper surfaces of the first electrode layer 21' and the second electrode layer 22'. The first insulating layer PAS1 may include openings OP that partially expose the electrode layers 21' and 22', respectively. The upper surfaces of the electrode layers 21' and 22' exposed through the openings OP can contact the contact electrodes CNE1 and CNE2 described above and below herein.

[0220] Then, the first electrode layer 21' and the second electrode layer 22' are cut in the cutting region CBA to form the first electrode 21 and the second electrode 22. Then, a first contact electrode CNE1 and a second contact electrode CNE2, respectively contacting (e.g., physically contacting) the two ends of each light-emitting element 30, can be formed on the target substrate SUB. Then, a third insulating layer PAS3 and a fourth insulating layer PAS4 can be formed on the first contact electrode CNE1 and the second contact electrode CNE2, thereby manufacturing the display device 10.

[0221] In the apparatus for inspecting light-emitting elements, the method for inspecting light-emitting elements using the apparatus, and the method for manufacturing a display device using the apparatus according to the embodiments, light-emitting elements with suitable or desired lengths can be obtained by sorting the light-emitting elements by length.

[0222] Furthermore, in the method for inspecting the light-emitting element and the method for manufacturing the display device according to the implementation scheme, since a defect-free light-emitting element can be obtained, defects in the display device can be prevented (or the possibility or degree of such defects can be reduced).

[0223] However, the effects of the embodiments are not limited to those described herein. The above and other effects of the embodiments will become more apparent to those skilled in the art upon reference to the claims.

[0224] In summarizing the detailed description, those skilled in the art will understand that many variations and modifications can be made to the disclosed embodiments without substantially departing from the principles of this disclosure. Therefore, the disclosed embodiments are used in a general and descriptive sense only and not for limiting purposes.

Claims

1. An apparatus for inspecting light-emitting elements, the apparatus comprising: A flow path unit extending in one direction and including a flow path, wherein a solution containing light-emitting elements moves along the flow path; At least one alignment unit, wherein the flow path extends from at least a portion of the flow path unit to the at least one alignment unit; At the end of the flow path unit and in which the light-emitting element is stacked; as well as Multiple alignment electrodes on the outer surface of the alignment unit, The stacking unit includes a storage component extending from the flow path unit, a plurality of inspection electrodes on two sides within the storage component, filter baffles at the upper and lower ends of the storage component, and an electrode moving component outside the flow path unit that moves the inspection electrodes.

2. The device of claim 1, wherein the flow path unit includes an inlet at an upper end of the flow path unit and an outlet at a lower end of the flow path unit, and each of the inlet and the outlet has a rectangular planar shape.

3. The device of claim 2, wherein the planar shape of the flow path is the same as the planar shape of the inlet or the outlet.

4. The device of claim 1, wherein the alignment unit includes a first alignment region and a second alignment region, and the first alignment region and the second alignment region are spaced apart from each other in the one direction.

5. The device of claim 4, wherein the diameter of the first alignment region or the second alignment region is greater than the length of the major axis of each of the light-emitting elements.

6. The device of claim 1, wherein the inspection electrode is spaced apart from the alignment electrode.

7. The device of claim 1, wherein the filter baffle includes a first filter baffle at the upper end of the storage member and a second filter baffle at the lower end of the storage member, and the first filter baffle and the second filter baffle respectively open or close the upper end and the lower end of the storage member.

8. A method for inspecting a light-emitting element using an apparatus for inspecting light-emitting elements, the apparatus comprising a flow path unit extending in one direction and including a flow path; At least one alignment unit, the flow path extending from at least a portion of the flow path unit to the at least one alignment unit; and a stacking unit at the end of the flow path unit where the light-emitting elements are stacked. The method includes: a storage component extending from the flow path unit; a plurality of inspection electrodes on two sides within the storage component; filter baffles at the upper and lower ends of the storage component; and an electrode moving component outside the flow path unit that moves the inspection electrodes. Prepare a solution in which the light-emitting element is mixed with a solvent; The light-emitting elements are sorted by length; The solution is injected into the device, and the alignment unit is used to align the light-emitting element. The stacking unit is used to align the aligned light-emitting element; and The resistance and brightness of the light-emitting element are checked by moving the inspection electrode of the stacking unit to determine whether the light-emitting element is defective.

9. The method of claim 8, wherein surface acoustic wave technology is used to sort light-emitting elements having a predetermined length, and The length of each of the light-emitting elements is 3.8 μm to 4.2 μm.

10. The method of claim 9, wherein the surface acoustic wave has a frequency band of 165 MHz to 175 MHz.

11. The method of claim 8, wherein the alignment unit rotates and aligns the light-emitting element by applying an electrical signal to the alignment electrode to generate an electric field.

12. The method of claim 11, wherein the stacking unit includes an electrode moving component for horizontally moving the inspection electrode, and the electrode moving component causes the inspection electrode to contact two sides of each light-emitting element aligned in the stacking unit to measure the resistance and brightness of the light-emitting element.

13. The method of claim 8, wherein the light-emitting element is obtained when it is determined to be defect-free in terms of resistance and brightness. When the light-emitting element is determined to be defective in terms of resistance or brightness, the light-emitting element is re-injected into the solution. The light-emitting element, which is re-injected into the solution, is mixed again using surface acoustic wave technology.

14. The method of claim 13, wherein the solution in which the re-injected light-emitting element is mixed is repeatedly sorted by length of the light-emitting element, the injection of the solution into the device and the alignment of the light-emitting element using the alignment unit, the alignment of the aligned light-emitting element using the stacking unit, and the determination of whether the light-emitting element is defective by checking the resistance and brightness of the light-emitting element.

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