Display device and manufacturing method for display device

Abstract

A display device and a manufacturing method for the display device are provided. The manufacturing method for the display device includes the following steps: a step of preparing a substrate on which a first electrode and a second electrode are formed; a step of arranging a light-emitting element between the first electrode and the second electrode; a step of forming a sacrificial pattern on the light-emitting element, the sacrificial pattern exposing one end and the other end of the light-emitting element; a step of forming a contact electrode material layer on the sacrificial pattern and one end and the other end of the light-emitting element, the one end and the other end being exposed by the sacrificial pattern; and a step of forming a first contact electrode and a second contact electrode by removing the contact electrode material layer overlapping the sacrificial pattern.

Description

Technical Field

[0001] The present disclosure relates to a display device and a manufacturing method for the display device. Background Art

[0002] As multimedia technology develops, the importance of display devices has steadily increased. In response to this, various types of display devices such as organic light emitting displays, liquid crystal displays (LCDs), etc. have been used.

[0003] The display device is a device for displaying an image, and includes a display panel such as an organic light-emitting display panel or a liquid crystal display panel. The light-emitting display panel may include a light-emitting element such as a light-emitting diode (LED), and examples of the light-emitting diode include an organic light-emitting diode (OLED) using an organic material as a fluorescent material and an inorganic light-emitting diode using an inorganic material as a fluorescent material. Summary of the invention

[0004] Technical issues

[0005] An object of the present disclosure is to provide a display device in which a mask process is reduced to improve process efficiency.

[0006] Another object of the present disclosure is to provide a method for manufacturing a display device in which a mask process is reduced to improve process efficiency.

[0007] It should be noted that the disclosed aspects are not limited thereto, and other aspects not mentioned herein will be apparent to those of ordinary skill in the art through the following description.

[0008] Technical Solution

[0009] According to a disclosed embodiment, a manufacturing method for a display device is provided, the manufacturing method comprising the following steps: preparing a substrate on which a first electrode and a second electrode are formed; arranging a light-emitting element between the first electrode and the second electrode; forming a sacrificial pattern on the light-emitting element to expose one end and the other end of the light-emitting element; forming a contact electrode material layer on the sacrificial pattern and the one end and the other end of the light-emitting element exposed by the sacrificial pattern; and forming a first contact electrode and a second contact electrode by removing the contact electrode material layer overlapping the sacrificial pattern.

[0010] A cross-sectional shape of the sacrificial pattern may have a tapered shape.

[0011] The contact electrode material layer may include a first region, a second region, and a third region, the first region overlapping with the sacrificial pattern and having a first thickness, the second region overlapping with one end and the other end of the light-emitting element exposed by the sacrificial pattern and having a second thickness, the third region not overlapping with the light-emitting element and having a third thickness, and the first thickness may be less than the second thickness and the third thickness.

[0012] The step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer may be performed by positive etching using a first etchant.

[0013] The etch selectivity of the first etchant with respect to the sacrificial pattern may be greater than the etch selectivity of the first etchant with respect to the contact electrode material layer.

[0014] During the step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer, a first region having a first thickness on the sacrificial pattern may be etched to expose the sacrificial pattern, and the exposed sacrificial pattern may be etched by a first etchant.

[0015] The sacrificial pattern may include a self-assembled monolayer.

[0016] The step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer may include forming a glue layer on one surface of the contact electrode material layer and removing the glue layer.

[0017] The contact electrode material layer may include a first portion overlapping with the sacrificial pattern and the glue layer and a second portion not overlapping with the sacrificial pattern but overlapping with the glue layer, and in the step of removing the glue layer, the first portion of the contact electrode material layer may be removed by attaching the first portion of the contact electrode material layer to a surface of the glue layer to form a first contact electrode and a second contact electrode.

[0018] The manufacturing method may further include removing the sacrificial pattern after removing the glue layer.

[0019] According to another disclosed embodiment, a manufacturing method for a display device is provided, the manufacturing method comprising the following steps: preparing a substrate on which a first electrode and a second electrode are formed; arranging a light-emitting element between the first electrode and the second electrode; forming a first contact electrode on the first electrode and one end of the light-emitting element; forming a sacrificial pattern covering the first contact electrode on the first contact electrode; forming a second contact electrode material layer on the sacrificial pattern and the other end of the light-emitting element; and forming a second contact electrode by removing the second contact electrode material layer overlapping the sacrificial pattern.

[0020] The sacrificial pattern may include a self-assembled monolayer.

[0021] The step of forming the second contact electrode by removing the second contact electrode material layer may include forming a glue layer on one surface of the second contact electrode material layer and removing the glue layer.

[0022] The second contact electrode material layer may include a first portion overlapping the sacrificial pattern and a second portion not overlapping the sacrificial pattern, and in the step of removing the glue layer, the first portion of the second contact electrode material layer may be removed by attaching the first portion of the second contact electrode material layer to a surface of the glue layer to form a second contact electrode.

[0023] According to a disclosed embodiment, a display device includes: a substrate; a light-emitting element disposed on the substrate; a first contact electrode in contact with one end of the light-emitting element; and a second contact electrode in contact with the other end of the light-emitting element, wherein the first contact electrode and the second contact electrode are separated from each other to face each other, and an end of the second contact electrode facing the first contact electrode has a cross-sectional shape of an inverted cone shape.

[0024] One end portion of the first contact electrode facing the second contact electrode may have a cross-sectional shape of an inverted tapered shape.

[0025] One end of the second contact electrode may be disposed on the other end of the light emitting element, and the second contact electrode may include a first region overlapping the light emitting element and a second region not overlapping the light emitting element, and the first region may have a thickness smaller than that of the second region.

[0026] At least a partial area of ​​an upper surface of the second contact electrode may have surface roughness.

[0027] The second contact electrode may have surface roughness on the second contact electrode in a region overlapping the light emitting element, and the first contact electrode may have surface roughness on the first contact electrode in a region overlapping the light emitting element.

[0028] The display device may further include an insulating layer disposed on the first contact electrode and the second contact electrode, wherein the insulating layer may include a first portion disposed on the first contact electrode and the second contact electrode and a second portion disposed in a space in which the first contact electrode and the second contact electrode are separated from each other, and the first portion and the second portion may be integrated.

[0029] Details of other embodiments are included in the detailed description and accompanying drawings.

[0030] Technical Effects

[0031] According to one embodiment of the present disclosure, the first contact electrode and the second contact electrode are formed by the same process using a sacrificial pattern, so that the number of masks can be reduced, thereby improving the process efficiency of the display device.

[0032] The effects according to the embodiments are not limited to the above-exemplified contents, and more various effects are included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a plan view showing a display device according to an embodiment.

[0034] Figure 2 is a plan view showing one pixel of a display device according to an embodiment.

[0035] Figure 3 It is along Figure 2 A schematic cross-sectional view taken along line III-III'.

[0036] Figure 4 is a schematic diagram showing a light emitting element according to an embodiment.

[0037] Figure 5 It shows Figure 3 An enlarged cross-sectional view of an example of an enlarged area A.

[0038] Figure 6 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device.

[0039] Figure 7 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device.

[0040] Figure 8 It shows Figure 7 An enlarged cross-sectional view of area B1.

[0041] Fig. 9 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device.

[0042] Fig.10 It shows Fig. 9 An enlarged cross-sectional view of area B2.

[0043] Fig.11 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device.

[0044] Fig.12 It shows Fig.11 An enlarged cross-sectional view of area B3.

[0045] Fig.13 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device.

[0046] Fig.14 It shows Figure 3 An enlarged cross-sectional view of another example of an enlarged area A.

[0047] Fig.15 It shows that along Figure 2 A cross-sectional view of another example taken along line III-III'.

[0048] Fig.16 It shows Fig.15 An enlarged cross-sectional view of an example of an enlarged area C.

[0049] Figures 17 to 22 It shows Fig.15 A cross-sectional view of a manufacturing process of a display device.

[0050] Fig.23 It shows that along Figure 2 A cross-sectional view of yet another example taken along line III-III'.

[0051] Fig.24 It shows that along Figure 2 A cross-sectional view of yet another example taken along line III-III'.

[0052] Fig.25 It shows Fig.24 An enlarged cross-sectional view of an enlarged area E.

[0053] Fig.26 It shows Fig.24 A cross-sectional view of a portion of a manufacturing process of a display device.

[0054] Fig. 27 It shows Fig.26 An enlarged cross-sectional view of an enlarged area D.

[0055] Figure 28 to Figure 31 It shows Fig.24 A cross-sectional view of a portion of a manufacturing process of a display device.

[0056] Fig.32 It shows that along Figure 2 A cross-sectional view of yet another example taken along line III-III'. DETAILED DESCRIPTION

[0057] Hereinafter, the invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. However, the invention may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0058] It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Throughout the specification, the same reference numerals refer to the same components.

[0059] It will 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 only used to distinguish one element from another element. For example, without departing from the teachings of the invention, the first element discussed below may be named as the second element. Similarly, the second element may also be named as the first element.

[0060] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0061] Figure 1 is a plan view showing a display device according to an embodiment.

[0062] Reference Figure 1 , the display device 10 displays a moving image or a still image. The display device 10 may refer to all electronic devices that provide a display screen. For example, a television, a laptop computer, a monitor, a billboard, an IoT device, a mobile phone, a smart phone, a tablet personal computer (PC), an electronic watch, a smart watch, a watch phone, a head-mounted display, a mobile communication terminal, an electronic diary, an electronic book, a portable multimedia player (PMP), a navigator, a game console, a digital camera, a video camera, etc. that provide a display screen may be included in the display device 10.

[0063] The display device 10 includes a display panel for providing a display screen. Examples of the display panel include an inorganic light emitting diode display panel, an organic light emitting display panel, a quantum dot light emitting display panel, a plasma display panel, and a field emission display panel. In the following, an inorganic light emitting diode display panel is used as an example of a display panel, but is not limited thereto. When the same technical spirit is applicable to other display panels, other display panels may be used.

[0064] Hereinafter, in the drawings in which an embodiment of the display device 10 is described, a first direction DR1, a second direction DR2, and a third direction DR3 are defined. The first direction DR1 and the second direction DR2 may be directions perpendicular to each other in one plane. The third direction DR3 may be a direction perpendicular to the plane in which the first direction DR1 and the second direction DR2 are located. The third direction DR3 is perpendicular to each of the first direction DR1 and the second direction DR2. In the embodiment in which the display device 10 is described, the third direction DR3 refers to the thickness direction (display direction) of the display device 10.

[0065] The display device 10 may have a rectangular shape on a plane including a long side and a short side that are longer in the first direction DR1 than in the second direction DR2. The corner portion where the long side and the short side of the display device 10 intersect each other on a plane may be a right angle, but is not limited thereto, and the corner portion may have a rounded shape. The shape of the display device 10 may be variously modified without being limited to the example shown. For example, the display device 10 may have other shapes such as a square shape on a plane, a square shape with rounded corners (vertices), other polygonal shapes, and a circular shape.

[0066] The display surface of the display device 10 can be set at one side in the third direction DR3 as the thickness direction. In the embodiment in which the display device 10 is described, unless otherwise specified, "upper part" refers to the display direction at one side in the third direction DR3, and "upper surface" refers to the surface oriented toward one side in the third direction DR3. In addition, "lower part" refers to the opposite direction of the display direction at the other side in the third direction DR3, and "lower surface" refers to the surface oriented toward the other side in the third direction DR3. In addition, "left", "right", "upper" and "lower" refer to directions when the display device 10 is viewed on a plane. For example, "right side" refers to one side of the first direction DR1, "left side" refers to the other side of the first direction DR1, "upper side" refers to one side of the second direction DR2, and "lower side" refers to the other side of the second direction DR2.

[0067] The display device 10 may include a display area DPA and a non-display area NDA. The display area DPA is an area in which a picture may be displayed, and the non-display area NDA is an area in which no picture is displayed.

[0068] The display area DPA may have a shape following the shape of the display device 10. For example, the display area DPA may have a rectangular shape on a plane similar to the overall shape of the display device 10. The display area DPA may occupy substantially the center of the display device 10.

[0069] The display area DPA may include a plurality of pixels PX. The plurality of pixels PX may be arranged in a matrix. The shape of each pixel PX may be a rectangular shape or a square shape on a plane. In an exemplary embodiment, each pixel PX may include a plurality of light emitting elements made of inorganic particles.

[0070] The non-display area NDA may be disposed near the display area DPA. The non-display area NDA may completely or partially surround the display area DPA. The non-display area NDA may constitute a frame of the display device 10.

[0071] Figure 2 is a plan view showing one pixel of a display device according to an embodiment. Figure 3It is along Figure 2 A schematic cross-sectional view taken along line III-III'.

[0072] Reference Figure 2 , each pixel PX of the display device 10 may include a light emitting area EMA and a non-light emitting area (not shown). The light emitting area EMA may be an area in which light emitted from the light emitting element 30 is emitted, and the non-light emitting area may be defined as an area in which the light emitted from the light emitting element 30 does not reach it and thus does not emit light.

[0073] The light emitting area EMA may include an area in which the light emitting element 30 is disposed and an adjacent area thereof. In addition, the light emitting area may also include an area in which light emitted from the light emitting element 30 is emitted by being reflected or refracted by other members.

[0074] Each pixel PX may further include a cutting area CBA disposed in a non-light emitting area. The cutting area CBA may be disposed at an upper side (or one side in the second direction DR2) of the light emitting area EMA in one pixel PX. The cutting area CBA may be disposed between the light emitting areas EMA of the pixels PX disposed adjacent to each other along the second direction DR2.

[0075] The cutting area CBA may be an area in which the electrodes 21 and 22 included in the corresponding pixels PX adjacent to each other are separated from each other along the second direction DR2. The electrodes 21 and 22 disposed in each pixel PX may be separated from each other in the cutting area CBA, and a portion of the electrodes 21 and 22 disposed in each pixel PX may be disposed in the cutting area CBA. The light emitting element 30 may not be disposed in the cutting area CBA.

[0076] Reference Figure 2 and Figure 3 , the display device 10 may include a substrate SUB, a circuit element layer PAL disposed on the substrate SUB, and a light emitting element layer disposed on the circuit element layer PAL. The light emitting element layer may include a first bank 40, a first electrode 21 and a second electrode 22, a second bank 60, a light emitting element 30, a first contact electrode 71 and a second contact electrode 72, a first insulating layer 51, and a second insulating layer 52.

[0077] The substrate SUB may be an insulating substrate. The substrate SUB may be formed of an insulating material such as glass, quartz, or a polymer resin. The substrate SUB may be a rigid substrate, but may be a flexible substrate capable of being bent, folded, curled, etc.

[0078] The circuit element layer PAL may be disposed on the substrate SUB. The circuit element layer PAL may include at least one transistor to drive the light emitting element layer.

[0079] The first bank 40 may be disposed on the circuit element layer PAL. Although not shown in the drawings, the circuit element layer PAL may include a via layer, and the first bank 40 may be disposed on the via layer of the circuit element layer PAL.

[0080] The first bank 40 may include a shape extending in the second direction DR2 in each pixel PX on a plane. The first bank 40 may include a first sub-bank 41 and a second sub-bank 42 separated from each other. A gap space in which the first sub-bank 41 and the second sub-bank 42 are separated from each other may provide a region in which a plurality of light emitting elements 30 are disposed.

[0081] The first sub-bank 41 and the second sub-bank 42 may have a structure in which at least a portion of the first sub-bank 41 and the second sub-bank 42 protrudes from the upper surface of the substrate SUB. The protruding portions of the first sub-bank 41 and the second sub-bank 42 may have inclined side surfaces. Since the first sub-bank 41 and the second sub-bank 42 include the inclined side surfaces, the first sub-bank 41 and the second sub-bank 42 may be used to change the moving direction of light emitted from the light emitting element 30 and moving toward the side surfaces of the first sub-bank 41 and the second sub-bank 42 to an upward direction (e.g., a display direction).

[0082] The first electrode 21 and the second electrode 22 may be respectively disposed on the first sub-bank 41 and the second sub-bank 42. The first electrode 21 and the second electrode 22 may be spaced apart from each other.

[0083] The first electrode 21 may extend in the second direction DR2 on a plane so as to overlap a partial region of the second bank 60 extending in the first direction DR1. The first electrode 21 may be electrically connected to the circuit element layer PAL through the first contact hole CT1.

[0084] The second electrode 22 may extend in the second direction DR2 on a plane so as to overlap a partial region of the second bank 60 extending in the first direction DR1. The second electrode 22 may be electrically connected to the circuit element layer PAL through the second contact hole CT2.

[0085] The first electrode 21 and the second electrode 22 may be electrically connected to the light emitting element 30, respectively, and a predetermined voltage may be applied to the light emitting element 30 to emit light. For example, the plurality of electrodes 21 and 22 may be electrically connected to the light emitting element 30 disposed between the first electrode 21 and the second electrode 22 through contact electrodes 71 and 72 to be described later, and an electrical signal applied to the electrodes 21 and 22 may be transmitted to the light emitting element 30 through the contact electrodes 71 and 72.

[0086] The first insulating layer 51 may be disposed on the plurality of electrodes 21 and 22. The first insulating layer 51 may be disposed on the first electrode 21 and the second electrode 22 to expose at least a portion of the first electrode 21 and the second electrode 22. The first insulating layer 51 may protect the first electrode 21 and the second electrode 22 and simultaneously insulate the first electrode 21 and the second electrode 22 from each other. In addition, the light emitting element 30 disposed on the first insulating layer 51 may be prevented from being damaged due to direct contact with other members.

[0087] The second bank 60 may be disposed on the first insulating layer 51. The second bank 60 may include portions extending in the first direction DR1 and the second direction DR2 on a plane, and may be disposed in a lattice pattern. The second bank 60 may be formed to have a height greater than that of the first bank 40. The second bank 60 may perform a function of preventing ink from overflowing to adjacent pixels PX (not shown) during an inkjet printing process of a manufacturing process of the display device 10.

[0088] The light emitting element 30 may be disposed on the first insulating layer 51 between the electrodes 21 and 22. The light emitting element 30 may have a shape extending in one direction. In addition, the light emitting element 30 may have a shape extending in one direction, and the direction in which the electrodes 21 and 22 extend may be substantially perpendicular to the direction in which the light emitting element 30 extends.

[0089] The first contact electrode 71 and the second contact electrode 72 may be disposed on the first electrode 21 and the second electrode 22, respectively. The first contact electrode 71 and the second contact electrode 72 may be spaced apart from each other. The first contact electrode 71 may include one end spaced apart from the second contact electrode 72 to face the second contact electrode 72, and the second contact electrode 72 may include one end spaced apart from the first contact electrode 71 to face the first contact electrode 71. In the present disclosure, one end of each of the first contact electrode 71 and the second contact electrode 72 may refer to an end disposed at each of the side surfaces spaced apart from each other to face each other.

[0090] The first contact electrode 71 and the second contact electrode 72 may have a shape extending in one direction on a plane. Each of the first contact electrode 71 and the second contact electrode 72 may have a shape extending in the second direction DR2. The first contact electrode 71 and the second contact electrode 72 may be spaced apart from each other in the first direction DR1 to face each other.

[0091] The first contact electrode 71 may be in contact with the first electrode 21 and one end of the light emitting element 30. The first contact electrode 71 may be disposed on the first electrode 21 so that a partial region thereof may be in contact with one surface of the first electrode 21 exposed by the first insulating layer 51, and another partial region thereof may be in contact with one end of the light emitting element 30.

[0092] The second contact electrode 72 may be in contact with the second electrode 22 and the other end of the light emitting element 30. The second contact electrode 72 may be disposed on the second electrode 22 so that a partial region thereof may be in contact with one surface of the second electrode 22 exposed by the first insulating layer 51, and another partial region thereof may be in contact with the other end of the light emitting element 30.

[0093] The first contact electrode 71 and the second contact electrode 72 may be disposed in parallel on the light emitting element 30. The first contact electrode 71 and the second contact electrode 72 may be spaced apart from each other on the light emitting element 30 to face each other. The first contact electrode 71 and the second contact electrode 72 may be spaced apart from each other on the light emitting element 30 to expose a portion of the light emitting element 30. The light emitting element 30 exposed by the first contact electrode 71 and the second contact electrode 72 may contact the second insulating layer 52 to be described later in the exposed region. In the region adjacent to the light emitting element 30, the first contact electrode 71 and the second contact electrode 72 may have different thicknesses for each region. This will be described later with reference to Figure 5 Detailed description.

[0094] The second insulating layer 52 may be entirely disposed on the substrate SUB. The second insulating layer 52 may serve to protect members disposed on the substrate SUB from external environments.

[0095] Figure 4 is a schematic diagram showing a light emitting element according to an embodiment.

[0096] Reference Figure 4 The light emitting element 30 is a particle type element and may have a rod or cylindrical shape with a predetermined aspect ratio. The light emitting element 30 may have a length greater than its diameter and may have an aspect ratio of 3:1 to 10:1, but is not limited thereto.

[0097] The light emitting element 30 may have a size ranging from nanometers (1 nm or more and less than 1 μm) to micrometers (1 μm or more and less than 1 mm). In one embodiment, both the diameter and length of the light emitting element 30 may have a size ranging from nanometers, or may have a size ranging from micrometers. In some other embodiments, the diameter of the light emitting element 30 may have a size ranging from nanometers, while the length of the light emitting element 30 may have a size ranging from micrometers. In some embodiments, a portion of the light emitting element 30 may have a diameter and / or length ranging from nanometers, while another portion of the light emitting element 30 may have a diameter and / or length ranging from micrometers.

[0098] In one embodiment, the light emitting element 30 may be an inorganic light emitting diode. In detail, 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 an electrical signal applied from an external power source and may thus emit light of a specific wavelength range.

[0099] The light emitting element 30 according to one embodiment may include a first semiconductor layer 31, an active layer 33, a second semiconductor layer 32 and an electrode layer 37 sequentially stacked in a longitudinal direction. The light emitting element may further include an insulating layer 38 surrounding outer surfaces of the first semiconductor layer 31, the second semiconductor layer 32 and the active layer 33.

[0100] The first semiconductor layer 31 may be, for example, an n-type semiconductor having a first conductivity type. The first semiconductor layer 31 may be doped with a first conductivity type dopant, for example, the first conductive dopant may be Si, Ge, Sn, Se, etc. In an exemplary embodiment, the first semiconductor layer 31 may be n-GaN doped with n-type Si.

[0101] The second semiconductor layer 32 may be disposed to be separated from the first semiconductor layer 31. The second semiconductor layer 32 may be, for example, a p-type semiconductor having a second conductivity type. The second semiconductor layer 32 may be doped with a second conductive dopant, for example, the second conductive dopant may be Mg, Zn, Ca, Ba, etc. In an exemplary embodiment, the second semiconductor layer 32 may be p-GaN doped with p-type Mg.

[0102] The active layer 33 may be disposed between the first semiconductor layer 31 and the second semiconductor layer 32. The active layer 33 may include a material of a single quantum well structure or a multi-quantum well structure. The active layer 33 may emit light by combining electron-hole pairs according to an electrical signal applied through the first semiconductor layer 31 and the second semiconductor layer 32, but is not limited thereto. The active layer 33 may have a structure in which a semiconductor material having a large energy band gap and a semiconductor material having a small energy band gap are alternately stacked, and may include a group III or group V semiconductor material according to a wavelength band of emitted light.

[0103] The light emitted from the active layer 33 may be emitted not only in the longitudinal direction of the light emitting element 30 but also on both sides of the light emitting element 30. The directivity of the light emitted from the active layer 33 is not limited to one direction.

[0104] The electrode layer 37 may be disposed on the second semiconductor layer 32. The electrode layer 37 may be an ohmic connection electrode, but is not limited thereto. The electrode layer 37 may be a Schottky contact electrode.

[0105] When the light emitting element 30 is electrically connected to an electrode or a contact electrode in the display device 10, the electrode layer 37 can reduce the resistance between the light emitting element 30 and the electrode or the contact electrode. The electrode layer 37 may include a metal having conductivity. For example, the electrode layer 37 may include at least one of aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin zinc oxide (ITZO). In addition, the electrode layer 37 may include a semiconductor material doped with n-type or p-type.

[0106] The insulating layer 38 is provided to surround the outer surface of the plurality of semiconductor layers and the electrode layer. In an exemplary embodiment, the insulating layer 38 may be provided to surround the outer surface of at least the active layer 33, and may extend in a direction along which the light emitting element 30 extends. The insulating layer 38 may be used to protect the above components. For example, the insulating layer 38 may be formed to surround the side of the component and expose both ends of the light emitting element 30 in the longitudinal direction. The insulating layer 38 may include a material having an insulating property. Therefore, the insulating layer 38 may prevent an electrical short circuit that may occur in the active layer 33 when the light emitting element 30 is in direct contact with the electrode to which the electrical signal is transmitted. In addition, the insulating layer 38 may protect the outer surface of the light emitting element 30, thereby preventing the luminous efficiency from being deteriorated.

[0107] In addition, in some embodiments, the outer surface of the insulating layer 38 may be surface treated. When manufacturing the display device 10, the light emitting element 30 may be aligned by being sprayed onto the electrode in a state where it is dispersed in a predetermined ink. The surface of the insulating layer 38 may be hydrophobically treated or hydrophilically treated so that the light emitting element 30 may be kept dispersed in the ink without being condensed with other light emitting elements 30 adjacent thereto.

[0108] Figure 5 It shows Figure 3 An enlarged cross-sectional view of an example of an enlarged area A.

[0109] Reference Figure 5 , the first contact electrode 71 (or one end of the first contact electrode 71) disposed in the adjacent region of the light emitting element 30 may include a first region 71A disposed to overlap the light emitting element 30 in the third direction DR3 and a second region 71B disposed not to overlap the light emitting element 30 in the third direction DR3. The first region 71A of the first contact electrode 71 may be disposed on the light emitting element 30.

[0110] The first contact electrode 71 provided on the light emitting element 30 (i.e., the first region 71A of the first contact electrode 71) may include a first surface 71S1, a second surface 71S2, and a third surface 71S3 in cross section. The first surface 71S1 may be a surface on the light emitting element 30 that contacts the insulating layer 38 of the light emitting element 30, the second surface 71S2 may be a surface facing the first surface 71S1, and the third surface 71S3 may be a surface connecting the first surface 71S1 and the second surface 71S2. For example, the first surface 71S1 of the first contact electrode 71 may be a lower surface of the first region 71A of the first contact electrode 71, the second surface 71S2 of the first contact electrode 71 may be an upper surface of the first region 71A of the first contact electrode 71, and the third surface 71S3 of the first contact electrode 71 may be a side surface of the first region 71A of the first contact electrode 71. Hereinafter, the first surface 71S1 , the second surface 71S2 , and the third surface 71S3 of the first contact electrode 71 may be respectively referred to as a lower surface 71S1 , an upper surface 71S2 , and a side surface 71S3 of the first region 71A of the first contact electrode 71 disposed on the light emitting element 30 .

[0111] Likewise, in the adjacent region of the light emitting element 30, the second contact electrode 72 may include a first region 72A disposed to overlap the light emitting element 30 in the third direction DR3 and a second region 72B disposed not to overlap the light emitting element 30 in the third direction DR3. The first region 72A of the second contact electrode 72 may be disposed on the light emitting element 30.

[0112] The second contact electrode 72 (i.e., the first region 72A of the second contact electrode 72) disposed on the light emitting element 30 may include a first surface 72S1, a second surface 72S2, and a third surface 72S3 in cross section. For example, the first surface 72S1 of the second contact electrode 72 may be a lower surface of the first region 72A of the second contact electrode 72, the second surface 72S2 of the second contact electrode 72 may be an upper surface of the first region 72A of the second contact electrode 72, and the third surface 72S3 of the second contact electrode 72 may be a side surface of the first region 72A of the second contact electrode 72. Hereinafter, the first surface 72S1, the second surface 72S2, and the third surface 72S3 of the second contact electrode 72 may be referred to as a lower surface 72S1, an upper surface 72S2, and a side surface 72S3 of the first region 72A of the second contact electrode 72 disposed on the light emitting element 30, respectively.

[0113] The first contact electrode 71 and the second contact electrode 72 may be disposed to be spaced apart from each other in the first direction DR1 on the light emitting element 30 . A side surface 71S3 of the first contact electrode 71 and a side surface 72S3 of the second contact electrode 72 may face each other on the light emitting element 30 .

[0114] The cross-sectional shape of one end of the first contact electrode 71 spaced apart from and facing the second contact electrode 72 may have an inverted tapered shape. Likewise, the cross-sectional shape of one end of the second contact electrode 72 spaced apart from and facing the first contact electrode 71 may have an inverted tapered shape.

[0115] In detail, the cross-sectional shape of the first contact electrode 71 provided on the light emitting element 30 may have an inverted tapered shape. In the present disclosure, the inverted tapered shape may be defined as a shape in which the upper surface of the cross section protrudes much more than the lower surface to have an inclined side surface. That is, when the cross-sectional shape is an inverted tapered shape, the size of the angle formed by the lower surface and the side surface may be an obtuse angle. In addition, a positive tapered shape may be defined as a shape in which the lower surface of the cross section protrudes much more than the upper surface to have an inclined side surface. That is, when the cross-sectional shape is a positive tapered shape, the angle formed by the lower surface and the side surface may be an acute angle.

[0116] The cross-sectional shape of the first region 71A of the first contact electrode 71 may have an inverted tapered shape. Therefore, the angle formed by the lower surface 71S1 and the side surface 71S3 of the first region 71A of the first contact electrode 71 may be an obtuse angle. In an exemplary embodiment, the first taper angle θ1 formed by the lower surface 71S1 and the side surface 71S3 of the first region 71A of the first contact electrode 71 may be within a range of greater than 90° and less than or equal to 145°, but is not limited thereto. The cross-sectional shape of one end portion of the first contact electrode 71 may have a forward tapered shape.

[0117] The cross-sectional shape of the second contact electrode 72 disposed on the light emitting element 30 may have an inverted tapered shape. The cross-sectional shape of the first region 72A of the second contact electrode 72 may have an inverted tapered shape. Therefore, the angle formed by the lower surface 72S1 and the side surface 72S3 of the first region 72A of the second contact electrode 72 may be an obtuse angle. In an exemplary embodiment, the second cone angle θ2 formed by the lower surface 72S1 and the side surface 72S3 of the second contact electrode 72 may be within a range of greater than 90° and less than or equal to 145°, but is not limited thereto. The cross-sectional shape of one end of the second contact electrode 72 may have a forward tapered shape.

[0118] The first contact electrode 71 and the second contact electrode 72 disposed in a region adjacent to the light emitting element 30 may have different thicknesses for each region.

[0119] The first contact electrode 71 disposed in a region adjacent to the light emitting element 30 may have different thicknesses according to the relative arrangement relationship with the light emitting element 30. A first region 71A of the first contact electrode 71 disposed on the light emitting element 30 may have a first thickness t1, and a second region 72A of the first contact electrode 71 not disposed on the light emitting element 30 may have a second thickness t2 different from the first thickness t1. The second thickness t2 may be greater than the first thickness t1.

[0120] The thickness relationship between the first region 72A and the second region 72B of the second contact electrode 72 disposed in the region adjacent to the light emitting element 30 may be substantially the same as that of the first contact electrode 71. The description of the thickness of the first region 72A and the second region 72B of the second contact electrode 72 disposed in the region adjacent to the light emitting element 30 will be replaced with the description of the thickness of the first region 71A and the second region 71B of the first contact electrode 71.

[0121] The second insulating layer 52 may be disposed on the first contact electrode 71 and the second contact electrode 72. The second insulating layer 52 may be disposed on the first contact electrode 71 and the second contact electrode 72 to include a gap space between the first contact electrode 71 and the second contact electrode 72 formed on the light emitting element 30, thereby completely covering the first contact electrode 71 and the second contact electrode 72.

[0122] The second insulating layer 52 may include a first portion disposed on the first contact electrode 71 and the second contact electrode 72 and a second portion disposed in a gap space between the first contact electrode 71 and the second contact electrode 72 on the light emitting element 30. The first portion and the second portion of the second insulating layer 52 may be integrated to form a single layer without a separate boundary line.

[0123] In the following, the Figure 3 manufacturing process of display devices.

[0124] Figure 6 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device.

[0125] First, refer to Figure 6, prepare a substrate SUB and a circuit element layer PAL formed on the substrate SUB. Subsequently, a first bank 40 including a first sub-bank 41 and a second sub-bank 42 is formed on the substrate SUB. The first sub-bank 41 and the second sub-bank 42 can be formed by the same mask process. Subsequently, a first electrode 21 and a second electrode 22 are formed on the first sub-bank 41 and the second sub-bank 42, respectively. The first electrode 21 and the second electrode 22 can include the same material and can be formed by the same mask process. Next, a first insulating layer 51 is formed on the first electrode 21 and the second electrode 22, a second bank 60 is formed on the first insulating layer 51, and a light-emitting element 30 is arranged on the first insulating layer 51 between the first electrode 21 and the second electrode 22. The light-emitting element 30 can be arranged to be ejected onto the substrate SUB by a printing process in a state where it is dispersed in ink.

[0126] Figure 7 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device. Figure 8 It shows Figure 7 An enlarged cross-sectional view of area B1.

[0127] Reference Figure 7 and Figure 8 , a sacrificial pattern SP is formed on the light emitting element 30. In the present embodiment, the sacrificial pattern SP may be formed by a mask process. In detail, a material layer for a sacrificial layer is entirely deposited on the first electrode 21, the second electrode 22 and the first insulating layer 51. Then, after a photoresist layer is coated on the material layer for a sacrificial layer and a photoresist pattern is formed by exposure and development, the material layer for a sacrificial layer is etched using the photoresist pattern as an etching mask. Then, as shown in FIG. Figure 7 and Figure 8 As shown in , the photoresist pattern may be removed by a stripping or ashing process to form a sacrificial pattern SP.

[0128] The sacrificial pattern SP may include a lower surface SP_S1, an upper surface SP_S2, a first side surface SP_S3, and a second side surface SP_S4. The cross-sectional shape of the sacrificial pattern SP may include a positive tapered shape. The width W1 of the lower surface SP_S1 of the sacrificial pattern SP in the cross-section may be greater than the width W2 of the upper surface SP_S2 of the sacrificial pattern SP. The angle formed by the lower surface SP_S1 of the sacrificial pattern SP and the first side surface SP_S3 of the sacrificial pattern SP may be an acute angle. In an exemplary embodiment, the third cone angle θ3 formed by the lower surface SP_S1 of the sacrificial pattern SP and the first side surface SP_S3 of the sacrificial pattern SP may be in a range greater than or equal to 35° and less than 90°. Similarly, the angle formed by the lower surface SP_S1 of the sacrificial pattern SP and the second side surface SP_S4 of the sacrificial pattern SP may be an acute angle. In an exemplary embodiment, the fourth cone angle θ4 formed by the lower surface SP_S1 of the sacrificial pattern SP and the second side surface SP_S4 of the sacrificial pattern SP may be in a range greater than or equal to 35° and less than 90°, but is not limited thereto. The cross-sectional shape of the sacrificial pattern SP may have an inverse tapered shape.

[0129] The third taper angle θ3 of the sacrificial pattern SP may be a complementary angle to the first taper angle θ1 of the first contact electrode 71. In addition, the fourth taper angle θ4 of the sacrificial pattern SP may be a complementary angle to the second taper angle θ2 of the second contact electrode 72. The complementary angle may be defined as an angle relative to another angle when the sum of the two angles is 180°. Since the first taper angle θ1 of the first contact electrode 71 and the second taper angle θ2 of the second contact electrode 72 are complementary to the third taper angle θ3 of the sacrificial pattern SP and the fourth taper angle θ4 of the sacrificial pattern SP, respectively, the cross-sectional shape of the sacrificial pattern SP may have a positive tapered shape, so that the cross-sectional shapes of the first contact electrode 71 and the second contact electrode 72 formed to be deposited and etched on the sacrificial pattern SP may have a shape as shown in FIG. Figure 5 In addition, in order to make the contact electrode material layer 70 (see FIG. 1 ) entirely deposited on the sacrificial pattern SP Fig. 9 ) has a different thickness for each region, the third and fourth taper angles θ3 and θ4 of the sacrificial pattern SP may be within a range greater than or equal to 35° and less than 90°, but are not limited thereto.

[0130] A sacrificial pattern SP may be disposed on the first insulating layer 51 between the first electrode 21 and the second electrode 22. A partial region of the sacrificial pattern SP may be disposed on the light emitting element 30 between the first electrode 21 and the second electrode 22. The partial region of the sacrificial pattern SP disposed on the light emitting element 30 may expose at least a portion of both ends of the light emitting element 30. Therefore, a maximum width of the sacrificial pattern SP may be less than a length "h" of the light emitting element 30 in the extension direction. In an exemplary embodiment, a width W1 of a lower surface SP_S1 of the sacrificial pattern SP may be less than a length "h" of the light emitting element 30 in the extension direction. Since the maximum width of the sacrificial pattern SP is less than the length "h" of the light emitting element 30, the sacrificial pattern SP may expose both ends of the light emitting element 30 on the light emitting element 30.

[0131] The sacrificial pattern SP may include the same material as that included in the contact electrode material layer 70 (see Fig. 9 ) In detail, the sacrificial pattern SP may include a material having an etching selectivity different from the etching selectivity of the contact electrode material layer 70 with respect to an etchant used to etch the contact electrode material layer 70. This will be described in detail later.

[0132] Fig. 9 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device. Fig.10 It shows Fig. 9 An enlarged cross-sectional view of area B2.

[0133] Reference Fig. 9 and Fig.10 , a contact electrode material layer 70 is formed on the first and second electrodes 21 and 22, the first insulating layer 51, and the light emitting element 30 on which the sacrificial pattern SP is formed. The contact electrode material layer 70 may be disposed on both ends of the sacrificial pattern SP and the light emitting element 30 exposed by the sacrificial pattern SP. In addition, the contact electrode material layer 70 may extend outward to be disposed on the first and second electrodes 21 and 22 and the first insulating layer 51. That is, the contact electrode material layer 70 may be entirely deposited on the substrate SUB.

[0134] The contact electrode material layer 70 may be deposited to have different thicknesses for each region by the step difference of the member disposed thereunder. In detail, in the region adjacent to the light emitting element 30, the contact electrode material layer 70 may be deposited to have different thicknesses according to the relative arrangement relationship between the sacrificial pattern SP and the light emitting element 30. The contact electrode material layer 70 may include a first region, a second region, and a third region in the region adjacent to the light emitting element 30. The first region of the contact electrode material layer 70 may overlap with the sacrificial pattern SP and the light emitting element 30, and may have a first thickness d1. The second region of the contact electrode material layer 70 may be a region overlapping with the light emitting element 30 exposed by the sacrificial pattern SP and having a second thickness d2. The third region of the contact electrode material layer 70 may be a region not overlapping with the sacrificial pattern SP and the light emitting element 30 and having a third thickness d3. The first thickness d1 may be less than the second thickness d2 and the third thickness d3, and the second thickness d2 may be less than the third thickness d3.

[0135] The contact electrode material layer 70 may be deposited to have different thicknesses due to the step difference formed by the sacrificial pattern SP and the light emitting element 30 disposed below the contact electrode material layer 70. In addition, the sacrificial pattern SP is formed to have a third taper angle θ3 and a fourth taper angle θ4 in the range of greater than or equal to 35° and less than 90°, and the first thickness d1 of the first region of the contact electrode material layer 70 formed on the sacrificial pattern SP may be less than the thickness of other regions. The contact electrode material layer 70 may include ITO, IZO, ITZO, etc., but is not limited thereto.

[0136] Fig.11 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device. Fig.12 It shows Fig.11 An enlarged cross-sectional view of area B3. Fig.13 It shows Figure 3 A cross-sectional view of a portion of a manufacturing process of a display device.

[0137] Reference Figures 11 to 13 , the first contact electrode 71 and the second contact electrode 72 may be formed by removing the contact electrode material layer 70 overlapping the sacrificial pattern SP. The step of removing the contact electrode material layer 70 overlapping the sacrificial pattern SP may be formed by performing positive etching on the substrate SUB having the contact electrode material layer 70 formed thereon without a separate mask process. In detail, the first contact electrode 71 and the second contact electrode 72 may be formed by a process such as an etch-back process of the substrate SUB having the contact electrode material layer 70 formed thereon.

[0138] In detail, the positive etching may be performed using a first etchant. The etching selectivity of the first etchant with respect to the sacrificial pattern SP may be different from the etching selectivity of the first etchant with respect to the contact electrode material layer 70. In the present embodiment, the etching selectivity of the first etchant with respect to the sacrificial pattern SP may be greater than the etching selectivity of the first etchant with respect to the contact electrode material layer 70. In an exemplary embodiment, the etching selectivity of the first etchant with respect to the sacrificial pattern SP may have a value three times or more of the etching selectivity of the first etchant with respect to the contact electrode material layer 70. For example, in the case where the contact electrode material layer 70 includes ITO, the sacrificial pattern SP may include benzaldehyde, chlorobenzene, tetrachloroethylene, trichloroethylene, etc.

[0139] When the contact electrode material layer 70 is etched by the first etchant, the thickness of the contact electrode material layer 70 may be substantially thinned. Fig.12 As shown in , the thinnest contact electrode material layer 70 disposed on the sacrificial pattern SP may be removed first, so that the contact electrode material layer 70 may be divided into a first region 71' and a second region 72'. In addition, the contact electrode material layer 70 disposed on the sacrificial pattern SP may be removed first, so that the sacrificial pattern SP' disposed thereunder may be exposed. Therefore, the sacrificial pattern SP' may be exposed by the contact electrode material layer 70, and thus etched by the first etchant. Subsequently, as Fig.13 As shown in , the sacrificial pattern SP having a high etching selectivity for the first etchant can be removed, and the patterned first contact electrode 71 and the second contact electrode 72 provided on the light emitting element 30 can be formed. The structures of the first contact electrode 71 and the second contact electrode 72 have been described above, so the detailed description thereof will be omitted. Subsequently, the second insulating layer 52 can be formed on the first contact electrode 71 and the second contact electrode 72, so that the structure of the light emitting element 30 can be manufactured as shown in FIG. Figure 3 The display device shown in .

[0140] In the method for manufacturing a display device according to the present embodiment, the first contact electrode 71 and the second contact electrode 72 can be simultaneously formed using the sacrificial pattern SP without separate mask processes for forming the first contact electrode 71 and the second contact electrode 72, respectively. Therefore, the number of masks for forming the first contact electrode 71 and the second contact electrode 72 can be reduced, so that the manufacturing process efficiency of the display device can be improved. In addition, since the etching selectivity of the first etchant used in the etching process for forming the first contact electrode 71 and the second contact electrode 72 with respect to the sacrificial pattern SP is greater than the etching selectivity of the first etchant with respect to the contact electrode material layer 70, the sacrificial pattern SP can also be removed in the same process. Therefore, since a separate process for removing the sacrificial pattern SP is not required, the process efficiency can be improved.

[0141] Fig.14 It shows Figure 3 An enlarged cross-sectional view of another example of an enlarged area A.

[0142] Reference Fig.14 In the present embodiment, the first contact electrode 71_1 and the second contact electrode 72_1 may further include a region protruding from each other in a direction in which the first contact electrode 71_1 and the second contact electrode 72_1 face each other in a region in which the first contact electrode 71_1 and the second contact electrode 72_1 are separated from each other. That is, each of the first contact electrode 71_1 and the second contact electrode 72_1 may include a step space on the light emitting element 30. The second insulating layer 52 may be disposed in the step space of each of the first contact electrode 71_1 and the second contact electrode 72_1 on the light emitting element 30.

[0143] The sacrificial pattern residue SP" may remain in the space between the step region of the first contact electrode 71_1 disposed on the light emitting element 30 and the light emitting element 30. Similarly, the sacrificial pattern residue SP" may remain in the space between the step region of the second contact electrode 72_1 disposed on the light emitting element 30 and the light emitting element 30. Fig.11 and Fig.12 When the etching time during the etch-back process shown in FIG. 5 is insufficient, the first contact electrode 71_1 and the second contact electrode 72_1 according to the present embodiment may be formed because a portion of the contact electrode material layer 70 disposed on the sacrificial pattern SP and the sacrificial pattern residue SP″ remain.

[0144] The first contact electrode 71_1 and the second contact electrode 72_1 are illustrated such that a sacrificial pattern residue SP″ remains in the step space on the light emitting element 30, but is not limited thereto. In some embodiments, the sacrificial pattern SP is completely removed between the step region of each of the first contact electrode 71_1 and the second contact electrode 72_1 disposed on the light emitting element 30 and the light emitting element 30, so that the material included in the second insulating layer 52 can be filled therebetween.

[0145] Hereinafter, another embodiment will be described. In the following embodiment, redundant descriptions of the same elements as those of the previously described embodiment will be omitted or simplified, and the description will be based on differences from the previously described embodiment.

[0146] Fig.15 It shows that along Figure 2 A cross-sectional view of another example taken along line III-III'. Fig.16 It shows Fig.15 An enlarged cross-sectional view of an example of an enlarged area C.

[0147] Reference Fig.15 and Fig.16 According to the display device of this embodiment and Figure 3 and Figure 5 The display device of the embodiment is different in that the cross-sectional shape of one end of the first contact electrode 71_2 includes a forward tapered shape, the cross-sectional shape of one end of the second contact electrode 72_2 includes an inverted tapered shape, and the upper surface 72US of the second contact electrode 72_2 has a predetermined surface roughness.

[0148] In detail, the cross-sectional shape of the first contact electrode 71_2 disposed on the light emitting element 30 may have a forward tapered shape. Therefore, the lower surface 71S1_2 of the first contact electrode 71_2 disposed on the light emitting element 30 may protrude more than the upper surface 71S2_2 thereof, and the first taper angle θ1_2 formed by the lower surface 71S1_2 of the first contact electrode 71_2 and the side surface 71S3_2 may be an acute angle.

[0149] The cross-sectional shape of the second contact electrode 72_2 disposed on the light emitting element 30 may have an inverted tapered shape. Therefore, the upper surface 72S2_2 of the second contact electrode 72_2 disposed on the light emitting element 30 may protrude more than the lower surface 72S1_2 thereof, and the second taper angle θ2_2 formed by the lower surface 72S1_2 of the second contact electrode 72_2 and the side surface 72S3_2 may be an obtuse angle.

[0150] The upper surface 72US of the second contact electrode 72_2 may have a predetermined surface roughness. In the present disclosure, "surface roughness" may be defined as "a surface (or uneven surface) on which a fine uneven pattern is formed", and the "fine uneven pattern" may include both an uneven pattern having a specific pattern and a "random uneven pattern". That is, "a surface having surface roughness" may mean a "non-flat surface". The surface roughness formed on the upper surface 72US of the second contact electrode 72_2 may be formed entirely on the upper surface 72US of the second contact electrode 72_2, but is not limited thereto. A partial area of ​​the upper surface 72US of the second contact electrode 72_2 may have a flat surface, and another partial area of ​​the upper surface 72US of the second contact electrode 72_2 may have a surface roughness.

[0151] The surface roughness formed on the upper surface 72US of the second contact electrode 72_2 may be formed in a process for forming the second contact electrode 72_2 during a manufacturing process of a display device to be described later. The upper surface 72US of the second contact electrode 72_2 may be formed to have an increased surface roughness due to damage to a portion of the surface during the manufacturing process of the display device. Therefore, the surface roughness formed on the upper surface 72US of the second contact electrode 72_2 may be formed randomly without having a predetermined pattern on the entire surface of the upper surface 72US of the second contact electrode 72_2.

[0152] In the following, the Fig.15 manufacturing process of display devices.

[0153] Figures 17 to 22 It shows Fig.15 A cross-sectional view of a manufacturing process of a display device.

[0154] Reference Fig.17 , a patterned first contact electrode 71_2 is formed on the light emitting element 30. The patterned first contact electrode 71_2 may be formed by a mask process. In detail, a first contact electrode material layer is entirely deposited on the substrate SUB. Subsequently, a photoresist layer is coated on the first contact electrode material layer, and a photoresist pattern having a pattern shape of the first contact electrode 71_2 and to be retained is formed by exposure and development. Then, as Fig.17 As shown in , the first contact electrode material layer is etched using the photoresist pattern as an etching mask, so that the first contact electrode 71_2 is formed.

[0155] Reference Fig.18 , a sacrificial pattern is formed on the first contact electrode 71_2. In the present embodiment, the sacrificial pattern may include a self-assembled monolayer SAM. A self-assembled monolayer SAM may be formed on the first contact electrode 71_2 to completely cover the first contact electrode 71_2. The self-assembled monolayer SAM may be formed by a coating method, a printing method, a deposition method, etc.

[0156] The self-assembled monolayer SAM can be an organic component formed as an organic molecule, which exists in a solution or gas phase, adsorbs each other and can spontaneously align to form a crystal structure. The self-assembled monolayer SAM has a film thickness of several nanometers (nm), so a very thin and uniform film is formed. Therefore, the self-assembled monolayer SAM can be used to easily control the first contact electrode 71_2 and the second contact electrode 72_2, so that the first contact electrode 71_2 and the second contact electrode 72_2 are separated from each other on the light-emitting element 30 having a size of nanometer units to micrometer units. The self-assembled monolayer SAM may include octadecyltrichlorosilane, fluoroalkyltrichlorosilane, perfluoroalkyltriethoxysilane, etc.

[0157] Reference Fig.19 , a second contact electrode material layer 72″_2 is entirely deposited on the substrate SUB on which the self-assembled monolayer SAM is formed. Then, as Fig. 20 As shown in , a glue layer GLUE is formed on a substrate SUB. One surface of the glue layer GLUE facing (or contacting) the second contact electrode material layer 72″_2 may have adhesive force. The glue layer GLUE having adhesive force may be attached to the second contact electrode material layer 72″_2 to remove a partial area of ​​the second contact electrode material layer 72″_2.

[0158] For details, refer to Fig. 20 The second contact electrode material layer 72"_2 may include a first region 72"A disposed in a region overlapping with the self-assembled monolayer SAM along the third direction DR3 and a second region 72"B disposed in a region not overlapping with the self-assembled monolayer SAM along the third direction DR3.

[0159] Reference Fig. 20 and Fig.21 , the second contact electrode 72_2 may be formed by removing the glue layer GLUE through a lift-off process. The first region 72"A of the second contact electrode material layer 72"_2, which is disposed in the region overlapping the self-assembled monolayer SAM along the third direction DR3, may be removed by attaching it to the glue layer GLUE, and a portion of the second region 72"B of the second contact electrode material layer 72"_2 may remain on the substrate SUB. However, in the step of removing the glue layer GLUE, a portion of the upper surface of the second region 72"B of the second contact electrode material layer 72"_2 may be attached to one surface of the glue layer GLUE and thus remain as a residue 72"B_1. That is, as Fig.21 As shown in, in the process of forming the second contact electrode 72_2 by removing the glue layer GLUE through a stripping process, the first region 72"A of the second contact electrode material layer 72"_2 can be removed on the substrate SUB by attaching it to the glue layer GLUE, and the surface of the second region 72"B of the second contact electrode material layer 72"_2 can be partially torn by the adhesive force of the glue layer GLUE, so that a part of the surface of the second region 72"B can be removed by attaching it to the glue layer GLUE as a residue 72"B_1, and another part thereof can be retained on the substrate SUB to form a second contact electrode 72_2 having a predetermined surface roughness formed thereon.

[0160] Reference Fig. 22 , the self-assembled monolayer SAM can be removed. The self-assembled monolayer SAM can be removed by an etching process. Subsequently, a second insulating layer 52 can be formed on the entire surface of the substrate SUB, so that the following can be manufactured: Fig.15The display device shown in .

[0161] Fig.23 It shows that along Figure 2 A cross-sectional view of yet another example taken along line III-III'.

[0162] Reference Fig.23 According to the display device of this embodiment and Fig.15 The display device of the embodiment of FIG. 7 is different in that the self-assembled monolayer SAM is also provided on the first contact electrode 71_2.

[0163] In detail, the self-assembled monolayer SAM may be disposed on the first contact electrode 71_2. The self-assembled monolayer SAM may be disposed between the first contact electrode 71_2 and the second contact electrode 72_2 on the light emitting element 30. The second insulating layer 52 may be disposed on the self-assembled monolayer SAM. After performing the process of forming the second contact electrode 72_2, the display device according to the present embodiment may be manufactured by forming the second insulating layer 52 without the need for a separate process of removing the self-assembled monolayer SAM. In this case, since a separate process for removing the self-assembled monolayer SAM may be omitted, the efficiency of the manufacturing process of the display device may be increased.

[0164] Fig.24 It shows that along Figure 2 A cross-sectional view of yet another example taken along line III-III'. Fig.25 It shows Fig.24 An enlarged cross-sectional view of an enlarged area E.

[0165] Reference Fig.24 , this embodiment and Figure 3 The embodiment is different in that each of the first contact electrode 71_3 and the second contact electrode 72_3 has surface roughness formed on an upper surface thereof in a region adjacent to the light emitting element 30 .

[0166] In detail, the first contact electrode 71_3 may include a first region 71A_3 on which surface roughness is formed and a second region 71B_3 on which surface roughness is not formed (i.e., a second region 71B_3 having a flat surface). The first region 71A_3 may be positioned in a region adjacent to a region in which the light emitting element 30 is disposed, and the second region 71B_3 may be positioned between the first region 71A_3 and the second bank 60.

[0167] Likewise, the second contact electrode 72_3 may include a first region 72A_3 on which surface roughness is formed and a second region 72B_3 on which surface roughness is not formed (i.e., a second region 72B_3 having a flat surface). The first region 72A_3 may be positioned in a region adjacent to a region in which the light emitting element 30 is disposed, and the second region 72B_3 may be positioned between the first region 72A_3 and the second bank 60.

[0168] The first contact electrode 71_3 and the second contact electrode 72_3 may have a surface roughness formed on the upper surface of one end facing each other. That is, a predetermined surface roughness may be formed on the upper surface of the first contact electrode 71_3 and the second contact electrode 72_3 disposed in the region adjacent to the light emitting element 30. The surface roughness may be formed in a process for forming the first contact electrode 71_3 and the second contact electrode 72_3 during the manufacturing process of the display device. The surface roughness is shown as being formed only on the upper surface of the first contact electrode 71_3 and the second contact electrode 72_3 disposed in the region adjacent to the light emitting element 30, but is not limited thereto. For example, the surface roughness may be formed entirely on the upper surface of the first contact electrode 71_3 and the second contact electrode 72_3.

[0169] The cross-sectional shape of each of one end of the first contact electrode 71_3 and one end of the second contact electrode 72_3 of the present embodiment may have an inverted tapered shape. Fig.25 , the angle formed by the lower surface 71S1_3 of the first region 71A_3 of the first contact electrode 71_3 disposed on the light emitting element 30 and the side surface 71S3_3 may be an obtuse angle. In an exemplary embodiment, the first cone angle θ1_3 formed by the lower surface 71S1_3 of the first region 71A_3 of the first contact electrode 71_3 and the side surface 71S3_3 may be in a range greater than 90° and less than or equal to 145°, but is not limited thereto. The cross-sectional shape of one end of the first contact electrode 71_3 may have a forward tapered shape. Similarly, the angle formed by the lower surface 72S1_3 of the second contact electrode 72_3 disposed on the light emitting element 30 and the side surface 72S3_3 may be an obtuse angle. In an exemplary embodiment, the second cone angle θ2_3 formed by the lower surface 72S1_3 of the first region 72A_3 of the second contact electrode 72_3 and the side surface 72S3_3 may be in a range greater than 90° and less than or equal to 145°, but is not limited thereto. A cross-sectional shape of one end portion of the second contact electrode 72_3 may have a forward tapered shape.

[0170] In the following, the Fig.24 manufacturing process of display devices.

[0171] Fig.26 It shows Fig.24 A cross-sectional view of a portion of a manufacturing process of a display device. Fig. 27 It shows Fig.26 An enlarged cross-sectional view of area D.

[0172] Reference Fig.26 and Fig. 27 , a self-assembled monolayer SAM_1 is formed on the light emitting element 30. The self-assembled monolayer SAM_1 formed on the light emitting element 30 may be formed to expose both ends of the light emitting element 30. The cross-sectional shape of the self-assembled monolayer SAM_1 may be substantially the same as the cross-sectional shape of the above-mentioned sacrificial pattern SP. For example, the cross-sectional shape of the self-assembled monolayer SAM_1 may include a positive tapered shape. In addition, the third cone angle θ3_3 of the self-assembled monolayer SAM_1 may be a supplementary angle of the first cone angle θ1_3 of the first contact electrode 71_3. In addition, the fourth cone angle θ4_3 of the self-assembled monolayer SAM_1 may be a supplementary angle of the second cone angle θ2_3 of the second contact electrode 72_3.

[0173] Figure 28 to Figure 31 It shows Fig.24 A cross-sectional view of a portion of a manufacturing process of a display device.

[0174] Reference Fig.28 , a contact electrode material layer 70' is entirely deposited on the substrate SUB on which the self-assembled monolayer SAM_1 is formed. The contact electrode material layer 70' may be disposed on the self-assembled monolayer SAM_1 and both ends of the light emitting element 30 exposed by the self-assembled monolayer SAM_1. In addition, the contact electrode material layer 70' may extend outward to be disposed on the first electrode 21 and the second electrode 22 and the first insulating layer 51.

[0175] Reference Fig.29 A glue layer GLUE_1 is formed on the contact electrode material layer 70 ′ in a region between the first sub-bank 41 and the second sub-bank 42 . One surface of the glue layer GLUE_1 may contact the contact electrode material layer 70 ′ disposed between the first sub-bank 41 and the second sub-bank 42 .

[0176] According to the relative arrangement relationship with the self-assembled monolayer SAM_1 and the glue layer GLUE_1 , the contact electrode material layer 70 ′ may include a first region 70 ′A, a second region 70 ′B and a third region 70 ′C.

[0177] The first region 70'A of the contact electrode material layer 70' may be a region overlapping the self-assembled monolayer SAM_1 and the glue layer GLUE_1 in the third direction DR3. The second region 70'B of the contact electrode material layer 70' may be a region overlapping the glue layer GLUE_1 in the third direction DR3 but not overlapping the self-assembled monolayer SAM_1 in the third direction DR3. The third region 70'C of the contact electrode material layer 70' may be a region not overlapping the glue layer GLUE_1 and the self-assembled monolayer SAM_1 in the third direction DR3.

[0178] The glue layer GLUE_1 is shown to be formed only in a partial region on the contact electrode material layer 70 ′ in the region between the first sub-bank 41 and the second sub-bank 42 , but is not limited thereto. For example, the glue layer GLUE_1 may be entirely formed on the substrate SUB.

[0179] Reference Fig.30 , the first contact electrode 71_3 and the second contact electrode 72_3 may be formed by removing the glue layer GLUE_1 through a lift-off process.

[0180] When removing the glue layer GLUE_1, the first region 70'A of the contact electrode material layer 70' overlapping the self-assembled monolayer SAM_1 and the glue layer GLUE_1 in the third direction DR3 may be removed by attaching it to one surface of the glue layer GLUE_1.

[0181] The second region 70'B of the contact electrode material layer 70' may remain on the substrate SUB. However, in the step of removing the glue layer GLUE_1, a portion of the upper surface of the second region 70'B of the contact electrode material layer 70' may adhere to one surface of the glue layer GLUE_1 to remain as residues 71'A_3 and 72'A_3. Fig.30 As shown in the figure, the surface of the second region 70'B of the contact electrode material layer 70' can be partially torn by the adhesive force of the glue layer GLUE_1, so that a part of the surface of the second region 70'B can be removed by attaching it to the glue layer GLUE_1 as residues 71'A_3 and 72'A_3, and another part thereof can be retained on the substrate SUB to form a first region 71A_3 of the first contact electrode 71_3 and a first region 72A_3 of the second contact electrode 72_3, and a predetermined surface roughness is formed on the first region 71A_3 and the first region 72A_3.

[0182] The third region 70'C of the contact electrode material layer 70' may remain on the substrate SUB. The second region 71B_3 of the first contact electrode 71_3 and the second region 72B_3 of the second contact electrode 72_3 may have a flat upper surface, and the second region 71B_3 of the first contact electrode 71_3 and the second region 72B_3 of the second contact electrode 72_3 correspond to the third region 70'C of the contact electrode material layer 70' that is not overlapped with the glue layer GLUE_1 and the self-assembled monolayer SAM_1 in the third direction DR3.

[0183] Reference Fig.31 , the self-assembled monolayer SAM_1 can be removed. The self-assembled monolayer SAM_1 can be removed by an etching process. Subsequently, a second insulating layer 52 can be formed on the entire surface of the substrate SUB, so that the following can be manufactured: Fig.24 The display device shown in .

[0184] Fig.32 It shows that along Figure 2 A cross-sectional view of yet another example taken along line III-III'.

[0185] Reference Fig.32 , this embodiment and Fig.24 The embodiment of FIG. 1 is different in that the self-assembled monolayer SAM_1 is also disposed between the first contact electrode 71_3 and the second contact electrode 72_3 on the light emitting element 30 .

[0186] In detail, the self-assembled monolayer SAM_1 may be disposed between the first contact electrode 71_3 and the second contact electrode 72_3 on the light emitting element 30. The second insulating layer 52 may be disposed on the first contact electrode 71_3, the second contact electrode 72_3, and the self-assembled monolayer SAM_1. The self-assembled monolayer SAM_1 may be aligned in parallel with the upper surface of one end of each of the first contact electrode 71_3 and the second contact electrode 72_3.

[0187] In the present embodiment, after performing the process of forming the first contact electrode 71_3 and the second contact electrode 72_3, when the second insulating layer 52 is formed without a separate process of removing the self-assembled monolayer SAM_1, the following can be manufactured: Fig.32 The display device shown in .

[0188] At the end of the detailed description, it will be appreciated by those skilled in the art that many changes and modifications may be made to the preferred embodiment without departing substantially from the principles of the invention. Therefore, the preferred embodiments of the disclosed invention are used only in a general and descriptive sense and not for the purpose of limitation.

Claims

1. A method for manufacturing a display device, the method comprising the following steps: preparing a substrate on which a first electrode and a second electrode are formed; Disposing a light emitting element between the first electrode and the second electrode; forming a sacrificial pattern on the light emitting element to expose one end and the other end of the light emitting element; forming a contact electrode material layer on the sacrificial pattern and the one end and the other end of the light emitting element exposed by the sacrificial pattern; as well as forming a first contact electrode and a second contact electrode by removing the contact electrode material layer overlapping the sacrificial pattern, wherein the step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer is performed by positive etching using a first etchant, or The step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer includes forming a glue layer on one surface of the contact electrode material layer and removing the glue layer.

2. The manufacturing method according to claim 1, wherein: A cross-sectional shape of the sacrificial pattern has a tapered shape.

3. The manufacturing method according to claim 1, wherein: During the step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer is performed by positive etching using the first etchant, the contact electrode material layer includes a first region, a second region, and a third region, the first region overlaps the sacrificial pattern and has a first thickness, the second region overlaps the one end and the other end of the light emitting element exposed by the sacrificial pattern and has a second thickness, the third region does not overlap the light emitting element and has a third thickness, and The first thickness is smaller than the second thickness and the third thickness.

4. The manufacturing method according to claim 3, wherein: An etching selectivity of the first etchant with respect to the sacrificial pattern is greater than an etching selectivity of the first etchant with respect to the contact electrode material layer.

5. The manufacturing method according to claim 3, wherein: During the step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer, the first region having the first thickness on the sacrificial pattern is etched to expose the sacrificial pattern, and the exposed sacrificial pattern is etched by the first etchant.

6. The manufacturing method according to claim 1, wherein: During the step of forming the first contact electrode and the second contact electrode by removing the contact electrode material layer includes forming the glue layer on the one surface of the contact electrode material layer and removing the glue layer, the sacrificial pattern includes a self-assembled monolayer.

7. The manufacturing method according to claim 6, wherein: The contact electrode material layer includes a first portion overlapping the sacrificial pattern and the glue layer and a second portion not overlapping the sacrificial pattern but overlapping the glue layer, and in the step of removing the glue layer, the first portion of the contact electrode material layer is removed by attaching the first portion of the contact electrode material layer to a surface of the glue layer to form the first contact electrode and the second contact electrode. 8 . The manufacturing method according to claim 6 , further comprising removing the sacrificial pattern after removing the glue layer.

9. A method for manufacturing a display device, the method comprising the following steps: preparing a substrate on which a first electrode and a second electrode are formed; Disposing a light emitting element between the first electrode and the second electrode; forming a first contact electrode on the first electrode and one end of the light emitting element; forming a sacrificial pattern covering the first contact electrode on the first contact electrode; forming a second contact electrode material layer on the sacrificial pattern and the other end of the light emitting element; as well as forming a second contact electrode by removing the second contact electrode material layer overlapping the sacrificial pattern, The step of forming the second contact electrode by removing the second contact electrode material layer includes forming a glue layer on a surface of the second contact electrode material layer and removing the glue layer.

10. The manufacturing method according to claim 9, wherein: The sacrificial pattern includes a self-assembled monolayer.

11. The manufacturing method according to claim 10, wherein: The second contact electrode material layer includes a first portion overlapping the sacrificial pattern and a second portion not overlapping the sacrificial pattern, and in the step of removing the glue layer, the first portion of the second contact electrode material layer is removed by attaching the first portion of the second contact electrode material layer to a surface of the glue layer to form the second contact electrode.

12. A display device manufactured according to the manufacturing method according to claim 1 or 9, the display device comprising: substrate; A light emitting element is disposed on the substrate; A first contact electrode in contact with one end of the light emitting element; as well as a second contact electrode, contacting the other end of the light emitting element, The first contact electrode and the second contact electrode are spaced apart from each other to face each other, and one end portion of the second contact electrode facing the first contact electrode has a cross-sectional shape of an inverted tapered shape.

13. The display device according to claim 12, wherein: One end portion of the first contact electrode facing the second contact electrode has a cross-sectional shape of an inverted tapered shape.

14. The display device according to claim 12, wherein: One end of the second contact electrode is disposed on the other end of the light emitting element, and the second contact electrode includes a first region overlapping the light emitting element and a second region not overlapping the light emitting element, and The first region has a thickness that is less than a thickness of the second region.

15. The display device according to claim 12, wherein: At least a portion of an upper surface of the second contact electrode has surface roughness.

16. The display device according to claim 15, wherein: The second contact electrode has surface roughness on the second contact electrode in a region overlapping the light emitting element, and The first contact electrode has surface roughness on the first contact electrode in a region overlapping the light emitting element.

17. The display device according to claim 12, further comprising an insulating layer disposed on the first contact electrode and the second contact electrode, in, The insulating layer includes a first portion disposed on the first contact electrode and the second contact electrode and a second portion disposed in a space in which the first contact electrode and the second contact electrode are separated from each other, and the first portion and the second portion are integrated.

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