Display device and method for manufacturing the same

Abstract

A display device is disclosed. The disclosed display device includes: a substrate having a plurality of self-luminous elements mounted on its front surface; a mold layer having an uneven front surface and covering both the front surface of the substrate and the plurality of self-luminous elements; and a polarization member spaced apart from the front surface of the mold layer so as not to optically adhere to the mold layer.

Description

Technical Field

[0001] The present disclosure relates to a display device and a method for manufacturing the same. More particularly, the present disclosure relates to a display device configured to reduce boundary visibility and external light reflectivity of adjacent display modules and prevent moire from becoming visible on a screen and a method for manufacturing the same. Background Art

[0002] In addition to the continued demand for high brightness, high resolution and larger size of display devices, the demand for high efficiency and low power consumption has been increasing recently with the trend of environmentally friendly electronic products.

[0003] Therefore, organic light emitting diode (OLED) panels have attracted much attention as a new display device to replace liquid crystal display (LCD) panels, but problems such as high cost due to low yield, large size, and reliability issues remain to be solved.

[0004] As a new product to replace or supplement the above products, there is growing interest in technology that directly mounts micro-LEDs that emit red, green, and blue light onto a substrate to create a panel.

[0005] The display device can be configured to display images without backlight by applying a self-luminous display device and to express various colors by operating in units of pixels or sub-pixels. The corresponding pixels or sub-pixels can be configured so that their operation is controlled by thin film transistors (TFTs). Summary of the Invention

[0006] [Technical Issues]

[0007] A display device configured to reduce boundary visibility and external light reflectivity of display modules adjacent to each other and prevent moire from becoming visible from a side surface of the display device and a method of manufacturing the same are provided.

[0008] [Technical solution]

[0009] According to an embodiment, a display device includes: a substrate having a plurality of self-luminous devices provided at a front surface thereof; a molding layer configured to cover both the front surface of the substrate and the plurality of self-luminous devices and having an uneven portion formed at the front surface thereof; and a polarization member spaced apart from the front surface of the molding layer so as not to optically adhere to the molding layer.

[0010] The uneven portion may include a plurality of uneven areas arranged irregularly.

[0011] An air layer may be provided between the mold layer and the polarization member, and the uneven portion may be integrally formed with the mold layer at a surface of the mold layer contacting the air layer.

[0012] The uneven portion may be a thin film anti-glare (AG) film or a thin film optical film formed with a plurality of fine uneven regions.

[0013] The display device may further include a filling layer configured to fill between the plurality of self-luminous devices, the filling layer having a black-based color and configured to cover side surfaces of the plurality of micro-LEDs. In this case, the filling layer may be configured to cover the front surface of the substrate except for the light-emitting surfaces of the plurality of micro-LEDs.

[0014] The plurality of micro LEDs may be electrically and physically coupled to the substrate electrode pads of the substrate through an adhesive layer formed of an anisotropic conductive film (ACF) or a conductive ink formed with fine conductive particles.

[0015] The plurality of micro LEDs may be physically coupled to the substrate electrode pads of the substrate through an adhesive layer formed of a non-conductive film (NCF).

[0016] The polarization member may include a glass substrate and a circular polarization layer disposed on the glass substrate.

[0017] According to an embodiment, a method of manufacturing a display device includes: transferring a plurality of micro LEDs to a front surface of a substrate; stacking a mold layer at the front surface of the substrate to cover light-emitting surfaces of the plurality of micro LEDs; forming an uneven portion on the mold layer; and disposing a polarization member to be spaced apart from the front surface of the mold layer so as not to optically adhere to the mold layer.

[0018] The uneven portion may be formed such that a plurality of uneven regions are irregularly disposed on the mold layer.

[0019] The uneven portion may be integrally formed at the surface of the mold layer through an embossing process.

[0020] The uneven portion may be formed by attaching a thin film anti-glare (AG) film at the surface of the mold layer, or by attaching a thin film optical film formed with a plurality of fine uneven regions.

[0021] The molding layer may be configured such that the transparent resin is formed by a UV curing molding method.

[0022] The air layer may be formed by spacing the mold layer and the polarization member apart.

[0023] The manufacturing method may further include, before forming the mold layer, stacking a filling layer having a black-based color to the substrate so as to expose light emitting surfaces of the plurality of micro LEDs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1is a front view schematically showing a display device according to an embodiment;

[0025] Figure 2 is a schematic perspective view showing an example of a display portion in which a plurality of display modules are connected and an external light reflection preventing member provided on the front surface thereof according to an embodiment;

[0026] Figure 3 is a diagram showing a Figure 1 A cross-sectional view of portion III is shown;

[0027] Figure 4 is a front view showing a display module according to an embodiment;

[0028] Figure 5 is a flowchart of a method for manufacturing a display device according to an embodiment;

[0029] Figure 6 is a cross-sectional view illustrating an example of a thin film transistor (TFT) substrate having an insulating layer formed at a front surface according to an embodiment;

[0030] Figure 7 is a cross-sectional view showing an example of laminating an adhesive layer to a TFT substrate according to an embodiment;

[0031] Figure 8 is a cross-sectional view showing an example of transferring a plurality of micro light emitting diodes (LEDs) to a TFT substrate according to an embodiment;

[0032] Figure 9 is a cross-sectional view showing an example of a filling layer stacked at the front surface of a TFT substrate excluding light emitting surfaces of a plurality of micro LEDs according to an embodiment;

[0033] Figure 10 is a cross-sectional view showing an example of stacking mold layers to cover a filling layer and light emitting surfaces of a plurality of micro LEDs according to an embodiment;

[0034] Figure 11 is a cross-sectional view illustrating an example of forming an uneven portion at a surface of a mold layer according to an embodiment;

[0035] Figure 12 is a front view showing a display portion in which a plurality of display modules are coupled to form a large screen size according to an embodiment;

[0036] Figure 13 is a cross-sectional view illustrating an example of an air layer formed between a display portion and an external light reducing member by disposing a polarization member at a predetermined distance at a front surface of the display portion according to an embodiment;

[0037] Figure 14is a flowchart of a method for manufacturing a display device according to another embodiment; and

[0038] Figure 15 is a cross-sectional view illustrating a portion of a display module of a display device according to another embodiment. DETAILED DESCRIPTION

[0039] Various embodiments will be described in more detail below with reference to the accompanying drawings. Various modifications may be made to the embodiments described herein. Specific embodiments may be illustrated in the drawings and described in detail in the specification. However, the specific embodiments depicted in the drawings are intended only to facilitate understanding of the various embodiments. Therefore, the various embodiments disclosed in the drawings are not intended to limit the scope of this disclosure to the specific embodiments, but should be understood to encompass all modifications or alternatives encompassed by the technical spirit and scope of the embodiments.

[0040] Terms including ordinal numbers such as first, second, etc. may be used to describe various elements, but these elements are not limited to the above terms. The above terms may be used only to distinguish one element from another.

[0041] In the present disclosure, it should be understood that terms such as "comprising", "including" and the like are used herein to indicate the presence of features, quantities, steps, operations, elements, components or combinations thereof, without excluding the possibility of the presence or addition of one or more other features, quantities, steps, operations, elements, components or combinations thereof. When a particular element is indicated as being "coupled with (another element)" / "coupled to" or "connected to" another element, it should be understood that the particular element may be directly coupled to or connected to the other element, but other elements may exist between them. On the other hand, when a particular element is indicated as being "directly coupled with (another element)" / "directly coupled to" or "directly connected to" another element, it should be understood that no other elements exist between them.

[0042] In the present disclosure, the expression “identical” may mean not only a complete match but also a degree of difference taking into account a range of processing errors.

[0043] In addition, when describing the present disclosure, if it is determined that a detailed description of the related known technology may unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be deleted or omitted.

[0044] The display module can be a display panel equipped with microscopic light-emitting diodes (micro-LEDs or μLEDs) for displaying images. The display module can be a type of flat panel display panel, each of which is configured with multiple inorganic LEDs less than or equal to 100 microns and can provide better contrast, response time, and energy efficiency than liquid crystal display (LCD) panels that require a backlight.

[0045] Both OLEDs and micro-LEDs, which are inorganic LEDs, have excellent energy efficiency, but micro-LEDs offer better brightness, luminous efficiency, and lifespan than OLEDs. Micro-LEDs are semiconductor chips that can emit light when powered. They can offer fast response times, low power consumption, and high brightness. For example, compared to LCDs or OLEDs, micro-LEDs can be more efficient at converting electrical energy into photons. That is, they offer a higher "brightness per watt" compared to related-art LCD or OLED displays. Consequently, compared to LEDs (e.g., with widths, lengths, and heights exceeding 100μm each) or OLEDs, micro-LEDs can be configured to have the same brightness with approximately half the energy. In addition to these advantages, micro-LEDs can also offer high resolution, excellent color, shading, and brightness, accurately represent a wide range of colors, and provide clear images even outdoors on sunny days. Furthermore, because micro-LEDs are highly resistant to burn-in and don't deform due to minimal heat generation, they can guarantee a long lifespan. The micro LED may have a flip-chip structure in which an anode electrode and a cathode electrode are formed at the same first surface, and a light emitting surface is formed at a second surface located on an opposite side of the first surface where the electrodes are formed.

[0046] In the present disclosure, a substrate may be provided with a thin film transistor (TFT) layer having a TFT circuit formed therein on the front surface, and a power supply circuit configured to supply power to the TFT circuit, a data drive driver, a gate drive driver, and a timing controller configured to control each drive driver may be provided on the rear surface. A plurality of pixels arranged on the TFT layer may be driven by the TFT circuit.

[0047] In the present disclosure, a glass substrate, a synthetic resin base substrate having a flexible material (e.g., polyimide (PI), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), etc.), or a ceramic substrate can be used for the substrate.

[0048] The TFT layer formed with the TFT circuit may be provided on the front surface of the substrate, and no circuit may be provided on the rear surface of the substrate. The TFT layer may be formed integrally on the substrate or bonded to one surface of a glass substrate manufactured in the form of a separate film.

[0049] The front surface of the substrate may be divided into an active area and a dummy area. The active area may correspond to the area occupied by the TFT layer at the front surface of the substrate, and the dummy area may be the area of ​​the front surface of the substrate other than the area occupied by the TFT layer.

[0050] The edge region of the substrate may be the outermost region of the glass substrate. Alternatively, the edge region of the substrate may be the remaining region excluding the region where the circuitry of the substrate is formed. Furthermore, the edge region of the substrate may include a portion of the front surface of the substrate adjacent to the side surface of the substrate, and a portion of the rear surface of the substrate adjacent to the side surface of the substrate. The substrate may be formed in a quadrilateral shape. Specifically, the substrate may be formed in a rectangular or square shape. The edge region of the substrate may include at least one of the four side surfaces of the glass substrate.

[0051] The TFT including the TFT layer (or backplane) is not limited to a specific structure or type. For example, in addition to low-temperature polysilicon TFTs (LTPS TFTs), the TFTs mentioned in the present invention can also be implemented using oxide TFTs and Si TFTs (polysilicon, a-silicon), organic TFTs, graphene TFTs, etc., and can be applied by only manufacturing P-type (or N-type) metal oxide semiconductor field effect transistors (MOSFETs) in a Si wafer complementary metal oxide semiconductor (CMOS) process.

[0052] The pixel driving method of the display module may be an active matrix (AM) driving method or a passive matrix (PM) driving method. The display module may be configured to form a wiring pattern to which each micro LED is electrically connected according to the AM driving method or the PM driving method.

[0053] A pixel region may be provided with multiple pulse amplitude modulation (PAM) control circuits. In this case, each sub-pixel provided in the pixel region may be controlled by a corresponding PAM control circuit. Alternatively, a pixel region may be provided with multiple pulse width modulation (PWM) control circuits. In this case, each sub-pixel provided in the pixel region may be controlled by a corresponding PWM control circuit.

[0054] A pixel region may be provided with both multiple PAM control circuits and multiple PWM control circuits. In this case, some of the sub-pixels provided in a pixel region may be controlled by the PAM control circuits, and the remaining sub-pixels may be controlled by the PWM control circuits. In addition, individual sub-pixels may be controlled by both the PAM control circuit and the PWM control circuit.

[0055] The display module may include a plurality of side surface wirings having a thin film thickness disposed at a certain distance along the side surface of the TFT substrate.

[0056] The display module may include multiple through-wiring members that are not exposed toward the side surfaces of the TFT substrate, replacing the side surface wiring exposed toward the side surfaces of the TFT substrate. Therefore, by minimizing the dummy area and maximizing the active area on the front surface of the TFT substrate, a borderless frame can be achieved, and the mounting density of micro-LEDs relative to the display module can be increased.

[0057] By coupling multiple display modules to provide a borderless form factor, it is possible to create a large-scale multi-display device that maximizes active area when coupling multiple display devices. In this case, the individual display modules can be formed to minimize dummy areas, maintaining the same spacing between adjacent pixels as in a single display module. This can thus make the seams at the coupling portions between the display modules invisible.

[0058] A display portion with a large screen size can be formed by connecting multiple display modules, and a polarization member can be provided on the front of the display portion to reduce the visibility of the borders between the display modules, which can make seams visible at the boundaries between the display modules, and to reduce external light reflectivity. The polarization member may include, for example, transparent glass and a circular polarization layer stacked on the front surface of the transparent glass. In this case, the polarization member can be provided at intervals on the front of the display portion, forming an air layer of predetermined thickness between the display portion and the polarization member.

[0059] The driving circuit can be implemented by a micro-integrated circuit (IC) configured to control the driving of at least 2n pixels arranged at the pixel region. Based on the application of the micro-IC to the display module instead of the TFT, only a channel layer connecting the micro-IC to each micro-LED can be formed at the TFT layer (or backplane).

[0060] The display module can be installed as a single unit in wearable devices, portable devices, handheld devices and electronic products that require various displays or are applied to electric fields, and can be applied to display devices by multiple components as a matrix type, such as but not limited to monitors for personal computers, high-definition televisions (TVs) and signs (or digital signs), electronic displays, etc.

[0061] Hereinafter, a display module according to an embodiment will be described with reference to the accompanying drawings.

[0062] Figure 1 is a front view schematically showing a display device according to an embodiment, Figure 2 is a schematic perspective view showing an example of a display portion in which a plurality of display modules are connected and a polarization member provided on the front side thereof, and Figure 3 It shows Figure 1 A cross-sectional view of portion III is shown.

[0063] Reference Figure 1 and Figure 2 The display device 1 may include a display portion 100 configured to couple a plurality of display modules 10 to provide a large-sized screen, and polarization members 90 provided at a predetermined distance apart at the front surface of the display portion 100 .

[0064] The display portion 100 may be formed by using a plurality of display modules 10 having a certain size and continuously coupled in the row direction and the column direction. In this case, the display modules adjacent to each other may be physically coupled and electrically coupled.

[0065] The display portion 100 may be formed into a square with the same width and length ratio or a rectangle with different width and length ratios according to the arrangement of the plurality of display modules 10. The width and length dimensions of the polarization member 90 may correspond to those of the corresponding display portion 100.

[0066] The polarization member 90 may be disposed at the front surface of the display portion to reduce boundary visibility that makes seams visible at boundaries of respective display modules and to reduce external light reflectivity.

[0067] Reference Figure 3 The polarization member 90 may be formed approximately in a plate shape, and may include a transparent glass substrate 91 and a circular polarization layer 93 stacked at one surface of the glass substrate 91 .

[0068] The circular polarization layer 93 may reduce boundary visibility that makes seams visible at boundaries of respective display modules based on having a black-based color, and reduce reflectivity by absorbing external light.

[0069] The polarization member 90 may be disposed to be spaced apart by a predetermined distance at the front surface of the display portion 100. Therefore, an air layer 80 of a predetermined thickness may be formed between the polarization member 90 and the display portion 100.

[0070] The polarization member 90 may be supported by the bezel member 7 surrounding the outside of the display portion 100. Therefore, the polarization member 90 may be disposed to be spaced apart from the display portion 100 by a predetermined distance.

[0071] Although not shown in the drawings, the bezel member 7 may be omitted from the display device 1. In this case, the polarization member 90 may be spaced apart from the display portion 100 via various support structures. For example, to space the polarization member 90 apart from the display portion 100, a plurality of spacers may be provided between the polarization member 90 and the display portion 100. In this case, the spacers preferably have a degree of transparency that does not reduce the amount of light emitted by the micro-LEDs, and are provided at points where they have no or minimal effect on the light emission.

[0072] As described above, by forming the air layer 80 between the polarization member 90 and the display portion 100 , problems that may occur in relation to the reflectivity and thickness of the display module 10 may be solved.

[0073] For example, by stacking a layer having a plurality of uneven regions (i.e., an uneven layer) on the front surface of the display module 10 to address the moire visible from the side surface of the display device 1, a decrease in visibility may be noticeable due to the increased reflectivity of the uneven regions. Furthermore, by stacking the polarizing layer so that it contacts the front surface of the display module 10, the thickness of the display module 10 may be increased, and thus the amount of light loss at the end of the display module 10 may be increased, and a color seam may occur in the color displayed at the end of the display module 10, which may not present the desired color.

[0074] Based on the thickness of the air layer 80 spacing the polarization member 90 from the front surface of the display portion 100 , the thickness of the display module 10 can be prevented from increasing due to the polarization member 90 , and the above-mentioned related problems can be fundamentally solved.

[0075] Figure 4 is a front view showing a display module.

[0076] Reference Figure 4 , the display module 10 may include a TFT substrate 20 and a plurality of micro LEDs 51 , 52 and 53 arranged on the TFT substrate 20 .

[0077] The TFT substrate 20 may include a glass substrate and a TFT layer including a TFT circuit on the front surface of the glass substrate. Furthermore, the TFT substrate 20 may be provided on the rear surface of the glass substrate and include a plurality of side surface wirings 15 electrically coupling the TFT circuit and a circuit configured to supply power to the TFT circuit and electrically coupled to a separate control substrate.

[0078] The TFT substrate 20 may include, at a front surface, an active region 20 a that displays an image and a dummy region 20 b that cannot display an image.

[0079] The active area 20a may be divided into a plurality of pixel areas in which a plurality of pixels are respectively arranged. The plurality of pixel areas may be divided into various forms, and for example, may be divided into the following forms: Figure 4 Each pixel region may include a sub-pixel region in which a plurality of sub-pixels are mounted and a pixel circuit region in which a pixel circuit for driving each sub-pixel is provided.

[0080] The plurality of micro LEDs 51, 52, and 53 may be light emitting devices for displaying images. The plurality of micro LEDs 51, 52, and 53 may be transferred to the pixel circuit region of the TFT layer, and the electrode pads of the respective micro LEDs may be electrically coupled to the substrate electrode pads 21, 22, and 23 ( Figure 3 ). Considering the arrangement of at least three micro-LEDs 51, 52, and 53 located at each pixel area, the common electrode pad can be formed in a straight line. Multiple micro-LEDs can be sub-pixels forming a single pixel. In this disclosure, one micro-LED can refer to one sub-pixel, and the related terms can be used interchangeably.

[0081] Three red, green, and blue micro LEDs 51 , 52 , and 53 are described as forming one pixel, but the embodiment is not limited thereto, and any number of micro LEDs may form one pixel.

[0082] The pixel driving method of the display module 10 according to the embodiment may be an active matrix (AM) driving method or a passive matrix (PM) driving method. The display module 10 may be configured to form a wiring pattern to which each micro LED is electrically coupled according to the AM driving method or the PM driving method.

[0083] The dummy region 20b may be included in the edge region of the glass substrate. For example, the edge region of the present disclosure may be a region where a plurality of side surface wirings 15 are formed, and may include a portion of the front surface of the TFT substrate 20 adjacent to the side surface 20c of the TFT substrate 20, and a portion of the rear surface of the TFT substrate 20 adjacent to the side surface 20c of the TFT substrate 20.

[0084] Reference Figure 3 , the display module 10 may be formed with a plurality of substrate electrode pads 21, 22, and 23 on the front surface of the TFT substrate 20. The plurality of substrate electrode pads 21, 22, and 23 may be electrically connected to the plurality of micro LEDs 51, 52, and 53. Therefore, the plurality of micro LEDs 51, 52, and 53 may be coupled to the TFT circuit of the TFT layer through the plurality of substrate electrode pads 21, 22, and 23.

[0085] The display module 10 has been described as including a TFT substrate 20, but is not limited thereto. A substrate that does not include a TFT layer including TFT circuitry may also be used. In this case, the drive circuit provided to the rear surface of the TFT substrate 20 may be implemented using a micro-integrated circuit (IC) that controls the driving of at least 2n pixels provided at the pixel region. Based on the application of the micro-IC to the display module 10 as described above, a channel layer may be formed on the TFT layer to connect the micro-IC to the individual micro-LEDs, instead of the TFTs.

[0086] The display module 10 may be configured such that the insulating layer 30, the adhesive layer 40, the filling layer 60, and the mold layer 70 are sequentially stacked at the front surface of the TFT substrate 20. Figure 3 The respective layers stacked at the front surface of the TFT substrate 20 are described.

[0087] An insulating layer 30 may be stacked on the front surface of the TFT substrate 20 to protect the TFT circuit of the TFT substrate 20 and prevent short circuits between adjacent wirings. In this case, the substrate electrode pads 21, 22, and 23 that need to be electrically connected to the micro-LEDs 51, 52, and 53 may not be covered by the insulating layer 30. The insulating layer 30 may be formed by applying, for example, a photoimageable solder resist (PSR) ink.

[0088] The adhesive layer 40 may be stacked and formed at the front surface of the TFT substrate 20 to fix the plurality of micro LEDs 51, 52, and 53 to the TFT substrate 20. In this case, for ease of handling, the adhesive layer 40 may be stacked at the front surface of the TFT substrate 20 to cover the entire front surface of the TFT substrate 20.

[0089] The adhesive layer 40 may be an anisotropic conductive film (ACF) or a non-conductive film (NCF).

[0090] When ACF is used as the adhesive layer 40, in order to avoid an increase in the manufacturing cost of the entire display device due to the high material cost of the ACF, a conductive ink including a plurality of nano-conductive particles can be used to form the adhesive layer 40. In this case, the adhesive layer 40 can be selectively stacked only on the substrate electrode pads 21, 22, and 23 in the entire front surface area of ​​the TFT substrate 20 and the surrounding areas of the substrate electrode pads 21, 22, and 23.

[0091] Each micro LED may have a flip-chip structure in which an anode electrode and a cathode electrode are formed at the same first surface S1 , and a light emitting surface is formed at a second surface S2 located on an opposite side of the first surface S1 where the electrodes are formed.

[0092] The plurality of micro LEDs 51 , 52 , and 53 may be electrically coupled to the corresponding substrate electrode pads 21 , 22 , and 23 through a thermocompression process after being transferred to the TFT substrate 20 , and may be stably fixed to the TFT substrate 20 through the adhesive layer 40 .

[0093] The filling layer 60 may be stacked at the front surface of the TFT substrate 20 and may cover the entire front surface of the TFT substrate 20 except for the light emitting surface S2 of the plurality of micro LEDs 51 , 52 , and 53 .

[0094] The filling layer 60 may be formed of an insulating material and may have a black color to absorb light emitted from the side surfaces and back surface S1 of the plurality of micro-LEDs 51, 52, and 53 and prevent crosstalk between adjacent micro-LEDs. Therefore, since the filling layer 60 can function as a black matrix, the display module 10 may not need to form a separate black matrix.

[0095] The molding layer 70 may cover the filling layer 60 and the light emitting surfaces S2 of the plurality of micro LEDs 51, 52, and 53. The molding layer 70 may be a transparent resin and may be formed by an ultraviolet (UV) curing molding method.

[0096] The mold layer 70 may be formed at the entire surface with an uneven portion 71. The uneven portion 71 may prevent ripples from becoming visible when the screen of the display device 1 is viewed obliquely from a side surface.

[0097] The uneven portion 71 may include a plurality of irregularly arranged uneven portions formed by processing and embossing the surface of the mold layer 70. Therefore, since the uneven portion 71 is integrally formed with the mold layer 70 rather than being stacked as a separate layer on the mold layer 70, an increase in the thickness of the display module 10 can be prevented. Consequently, a color seam can be prevented from becoming visible at the ends of the display module 10 due to the increased thickness of the display module 10.

[0098] Since the polarization member 90 is provided at a predetermined distance from the front surface of the display portion 100, the thickness of the display module 10 is not increased by the polarization member 90. Therefore, in the present disclosure, when a thin anti-glare (AG) film is stacked on the mold layer 70 instead of the uneven portion 71, the increase in the thickness of the display module 10 can be minimized and the ripples can be prevented from becoming visible. In addition, an optical film having fine uneven portions formed thereon can be formed by laminating the mold layer 70 with a pressure-sensitive adhesive (PSA) instead of the uneven portion 71.

[0099] The following will refer to Figures 5 to 13 A manufacturing process of the display device 1 according to the embodiment of the present disclosure is described.

[0100] Figure 5 is a flowchart showing a process of manufacturing a display device according to an embodiment, and Figure 6 is a cross-sectional view showing a TFT substrate having an insulating layer formed at the front surface.

[0101] Reference Figure 6 , the insulating layer 30 may be formed on a glass substrate, and the TFT substrate 20 formed with a TFT layer is formed on the glass substrate.

[0102] A plurality of substrate electrode pads 21 , 22 , and 23 to which the micro LEDs 51 , 52 , and 53 transferred to the TFT substrate are respectively connected may be arranged at the front surface of the TFT substrate 20 .

[0103] The insulating layer 30 may cover the entire front surface area of ​​the TFT substrate 20 except for an area where the plurality of substrate electrode pads 21 , 22 , and 23 are provided.

[0104] The insulating layer 30 may be formed at the front surface of the TFT substrate 20 by sequentially performing exposure and curing processes after applying an insulating material (eg, photoimageable solder resist (PSR) ink).

[0105] Figure 7 is a cross-sectional view showing an example of laminating an adhesive layer to a TFT substrate.

[0106] Reference Figure 7 , the adhesive layer 40 may be attached to the front surface of the TFT substrate 20 by a lamination method. As the adhesive layer 40, an anisotropic conductive film (ACF) or a non-conductive film (NCF) may be used.

[0107] The adhesive layer 40 may be selectively stacked only to a desired area, rather than being attached to the entire front surface area of ​​the TFT substrate 20. In this case, the adhesive layer 40 may be formed by using a conductive ink including a plurality of nano-conductive particles.

[0108] As described above, when the adhesive layer 40 is formed using conductive ink, the adhesive layer 40 can be stacked by selectively spraying the conductive ink only on the substrate electrode pads 21, 22 and 23 in the entire front surface area of ​​the TFT substrate 20 and the surrounding areas of the substrate electrode pads 21, 22 and 23.

[0109] Figure 8 is a cross-sectional view showing an example of transferring a plurality of micro LEDs to a TFT substrate.

[0110] Reference Figure 8 , the plurality of micro LEDs 51 , 52 , and 53 may be transferred to the TFT substrate 20 ( S11 ).

[0111] A plurality of micro-LEDs grown from an epitaxial substrate (not shown) may be separated from the epitaxial substrate by a laser lift-off (LLO) method and arranged on a relay substrate (not shown). Adjacent micro-LEDs arranged on the relay substrate may maintain a first chip pitch in the X-axis direction (or row direction) and a second chip pitch in the Y-axis direction (or column direction).

[0112] The plurality of micro LEDs 51 , 52 , and 53 transferred to the relay substrate may be transferred to the TFT substrate 20 through a transfer process such as a laser transfer method, a roll-to-roll transfer method, and a pick-and-place transfer method.

[0113] When transferred to the TFT substrate 20 , the plurality of micro LEDs 51 , 52 , and 53 may be transferred to the TFT substrate 20 at a chip pitch different from the corresponding first chip pitch and second chip pitch on the relay substrate.

[0114] The plurality of micro LEDs 51, 52, and 53 transferred to the TFT substrate 20 can be respectively arranged at the corresponding substrate electrode pads 21, 22, and 23. In this state, the plurality of micro LEDs 51, 52, and 53 can be thermally pressed toward the TFT substrate 20 side by using a pressing member (not shown). In this case, the die (not shown) supporting the TFT substrate 20 and the pressing member can be respectively equipped with a heater (for example, a sheath heater, etc.).

[0115] Based on the fact that a portion of the adhesive layer 40 (for example, a portion located between the plurality of micro LEDs and the substrate electrode pad) is melted by the heat generated when the thermal pressing is performed, the plurality of micro LEDs 51, 52, and 53 can be stably physically fixed to the respective substrate electrode pads 21, 22, and 23 of the TFT substrate 20. In this case, the plurality of micro LEDs 51, 52, and 53 can contact the electrode pads 21, 22, and 23 by the pressing force of the pressing member and be electrically coupled.

[0116] Figure 9 is a cross-sectional view showing an example of a filling layer stacked at the front surface of a TFT substrate excluding light emitting surfaces of a plurality of micro LEDs.

[0117] Reference Figure 9 A filling layer may be formed by coating an insulating material capable of absorbing light at the front surface of the TFT substrate 20 to which the plurality of micro LEDs 51, 52, and 53 are transferred (S12).

[0118] The filling layer 60 may be formed in a black-based color so that light absorption is possible. The filling layer 60 may be applied to cover the entire front surface of the TFT substrate 20 except for the light emitting surface S2 of the plurality of micro LEDs 51 , 52 , and 53 .

[0119] Filling layer 60 may have a thickness substantially corresponding to a thickness from a surface of adhesive layer 40 (eg, a boundary of adhesive layer 40 and filling layer 60 ) to light emitting surfaces S2 of the plurality of micro LEDs 51 , 52 , and 53 .

[0120] In this case, the filling layer 60 can absorb light emitted from the back surface S1 of the plurality of micro LEDs 51, 52, and 53 based on the side surface formed to surround the plurality of micro LEDs 51, 52, and 53 in all directions, and prevent crosstalk between adjacent micro LEDs. As described above, the filling layer 60 can function as a black matrix.

[0121] Figure 10 is a cross-sectional view showing an example of stacking a mold layer to cover a filling layer and light emitting surfaces of a plurality of micro LEDs, and Figure 11 is a cross-sectional view illustrating an example in which an uneven portion is formed at a surface of a mold layer.

[0122] Reference Figure 10 , a mold layer 70 may be stacked on the entire front surface area of ​​the TFT substrate 20 ( S13 ).

[0123] The molding layer 70 may be formed by UV curing molding, wherein a resin having such a degree of transparency covers the filling layer 60 and the light emitting surfaces of the micro LEDs 51 , 52 , and 53 that light emitted therefrom satisfies a required light amount.

[0124] Reference Figure 11 , the surface of the mold layer 70 may be embossed, and an uneven portion 71 including a plurality of uneven portions irregularly arranged at the entire surface of the mold layer 70 may be formed ( S14 ).

[0125] Based on the formation of the uneven portion 71 by processing the surface of the mold layer 70, it is possible not to increase the thickness of the display module 10. The uneven portion 71 may be formed with respect to the entire surface area of ​​the mold layer 70.

[0126] Based on forming the uneven portion 71 at the surface of the mold layer 70 as described above, when a viewer views the screen of the display apparatus 1 obliquely from a side surface of the display apparatus 1 in an oblique direction, moire can be prevented from becoming visible.

[0127] By stacking an anti-glare (AG) film (not shown) of a thin film on the mold layer 70 instead of the uneven portion 71, the thickness increase of the display module 10 can be minimized and the ripples can be prevented from becoming visible. In addition, an optical film having fine uneven portions formed thereon can be formed by laminating the mold layer 70 with a pressure-sensitive adhesive (PSA) instead of the uneven portion 71.

[0128] Figure 12 is a front view showing a display portion in which a plurality of display modules are connected to achieve a large screen size, and Figure 13is a cross-sectional view showing an example of an air layer formed between a display section and a polarization member by disposing the polarization member at a predetermined distance at the front surface of the display section.

[0129] Reference Figure 12 The display module 10 formed through the above-described sequential processes may form the display portion 100 by continuously coupling a plurality of them in the row direction and the column direction.

[0130] Reference Figure 13 , the front surface of the display portion 100 may be provided with polarization members 90 spaced apart at a preset distance ( S15 ).

[0131] The polarization member 90 may prevent the boundary between the display modules 10 coupled to each other from becoming visible and reduce external light reflectivity through the circular polarization layer 93 having the black-based color.

[0132] The polarization member 90 can be provided by the frame member 7 (refer to Figure 1 ) to maintain the spacing distance. In this case, the air layer 80 may be formed between the polarization member 90 and the display portion 100. Therefore, the mold layer 70 and the polarization member 90 of each display module 10 may not optically adhere to each other.

[0133] Light emitted from the plurality of micro LEDs arranged at the respective display modules 10 of the display portion 100 may not be refracted when it passes through the air layer 80 and may be completely irradiated to the outside of the display apparatus 1 through the polarization member 90 .

[0134] As described above, since the polarization members 90 are spaced apart to provide air gaps with respect to the respective display portions 100, the thickness of the display module 10 may not be increased. Therefore, the above-mentioned problem of increasing the thickness of the display module 10 can be fundamentally prevented.

[0135] The display device 1 may be configured such that the bezel member 7 is omitted, and in this case, the polarization member 90 may be provided to be spaced apart from the display portion 100 by various supporting structures not shown in the drawings.

[0136] For example, a transparent spacer (not shown) may be provided between the polarization member 90 and the display portion 100. In this case, the spacer is preferably formed of a material having transparency that does not reduce the amount of light emitted by the micro-LEDs and minimizes light loss or light reflection. In addition, the spacer is preferably provided at a point that does not affect the amount of light emitted by the micro-LEDs or minimizes the amount of light emitted by the micro-LEDs.

[0137] Figure 14 is a cross-sectional view showing a portion of a display module of a display device according to another embodiment, and Figure 15is a flowchart illustrating a process of manufacturing a display device according to another embodiment.

[0138] A display device 1a according to another embodiment of the present disclosure may be similar in structure to the above display device 1, and the same reference numerals may be applied to the same elements. The display device 1a may be described below, but descriptions of the same elements as the above display device 1 may be omitted.

[0139] Reference Figure 14 The display device 1a can omit the adhesive layer 40 of the display device 1 (refer to Figure 3 In this case, the display device 1a may include a soldering member 41 that may replace the adhesive layer 40. The soldering member 41 may be a solder ball or a micro bump.

[0140] Soldering member 41 may be patterned on substrate electrode pads 21, 22, and 23 through a reflow process. Multiple micro LEDs 51, 52, and 53 may be electrically and physically coupled to substrate electrode pads 21, 22, and 23 through soldering member 41 through a thermal compression process after the transfer process.

[0141] Unlike the above-mentioned display device 1, the display device 1a can omit the filling layer 60 (see Figure 3 In this case, the mold layer 70 may be filled between the plurality of micro LEDs 51, 52, and 53.

[0142] Reference Figure 15 , a display device 1 a according to another embodiment may be manufactured using a process slightly different from that of the above-described display device 1 .

[0143] First, the insulating layer 30 may be formed at the remaining region except for the region where the plurality of substrate electrode pads 21 , 22 , and 23 are provided in the entire front surface region of the TFT substrate 20 .

[0144] The solder member 41 may be applied to the respective substrate electrode pads 21 , 22 , and 23 through a reflow process.

[0145] Then, in operation S21, the plurality of micro LEDs 51, 52, and 53 can be transferred to the TFT substrate 20. The plurality of micro LEDs 51, 52, and 53 can be thermally pressed toward the TFT substrate 20 side using a pressing member in this state. Therefore, since the welding member 41 is melted by the heat generated when the thermal pressing is performed, the plurality of micro LEDs 51, 52, and 53 can be physically and stably fixed and electrically coupled to the respective substrate electrode pads 21, 22, and 23 of the TFT substrate 20.

[0146] Then, a mold layer 70 may be stacked at the entire front surface area of ​​the TFT substrate 20 using a UV curing molding method ( S22 ), and an uneven portion 71 including a plurality of irregularly arranged uneven portions may be formed at the entire surface of the mold layer ( S23 ).

[0147] In this case, a lamination process of a thin film AG film may be performed at the mold layer 70 instead of the uneven portion 71 .

[0148] After the plurality of display modules 10 formed through the above process are continuously coupled multiple times in row and column directions, polarization members 90 may be disposed at a preset distance apart at the front surface of the display portion 100 ( S24 ).

[0149] The display device 1a according to another embodiment described above can, like the display device 1 described above, not only reduce boundary visibility and external light reflectivity of adjacent display modules 10 but also prevent moire from becoming visible from side surfaces of the display device 1a.

[0150] Above, various embodiments of the present disclosure have been described separately and individually, but each embodiment is not necessarily implemented alone, and the configurations and operations of each embodiment may be implemented in combination with at least one other embodiment.

[0151] While the present disclosure has been shown and described with reference to various exemplary embodiments thereof, it should be understood that the various exemplary embodiments are intended to be illustrative rather than restrictive. Those skilled in the art will appreciate that various changes in form and details may be made therein without departing from the true spirit and full scope of the present disclosure (including the appended claims and their equivalents).

[0152] [Industrial Applicability]

[0153] The present disclosure relates to a display device and a method for manufacturing the same.

Claims

1. A display device, comprising: substrate; A plurality of self-luminous devices are arranged on the front surface of the substrate; a mold layer configured to cover the front surface of the substrate and contact light-emitting surfaces of the plurality of self-luminous devices, and having at least one uneven portion formed at the front surface of the mold layer so that the at least one uneven portion can prevent ripples from becoming visible when the screen of the display device is viewed obliquely from a side surface; as well as a polarization member spaced apart from the front surface of the mold layer so as not to optically adhere to the mold layer, The uneven portion includes a plurality of irregularly arranged uneven areas.

2. The display device according to claim 1 , further comprising an air layer provided between the mold layer and the polarization member, and in, The uneven portion is integrally formed with the mold layer at a surface of the mold layer contacting the air layer.

3. The display device according to claim 1, wherein The uneven portion includes a thin film anti-glare AG film. The display device according to claim 1 , wherein: The uneven portion includes a thin film optical film formed with a plurality of fine uneven regions.

5. The display device according to claim 1, further comprising a filling layer disposed between the plurality of self-luminous devices, in, The filling layer includes a black-based color to absorb external light and is configured to cover side surfaces of the plurality of micro LEDs. The display device according to claim 5 , wherein: The filling layer is configured to cover a front surface of the substrate except for light emitting surfaces of the plurality of micro LEDs.

7. The display device according to claim 5, wherein The plurality of micro LEDs are electrically and physically coupled to the substrate electrode pads of the substrate through an adhesive layer including an anisotropic conductive film (ACF) or a conductive ink including fine conductive particles.

8. The display device according to claim 5, wherein The plurality of micro LEDs are physically coupled to the substrate electrode pads of the substrate through an adhesive layer including a non-conductive film NCF.

9. The display device according to claim 1, wherein The polarization member comprises: glass substrate; and The circular polarization layer is arranged on the glass substrate.

10. A method for manufacturing a display device, the method comprising: transferring a plurality of micro-LEDs to a front surface of a substrate; stacking a molding layer at the front surface of the substrate to cover light emitting surfaces of the plurality of micro LEDs; On the molding layer, contacting light-emitting surfaces of a plurality of self-luminous devices; forming at least one uneven portion on the mold layer so that when the screen of the display device is viewed obliquely from a side surface, the at least one uneven portion can prevent ripples from becoming visible; as well as disposing a polarization member to be spaced apart from a front surface of the mold layer so as not to optically adhere to the mold layer, The uneven portion includes a plurality of uneven areas disposed on the mold layer.

11. The method according to claim 10, wherein: Forming the uneven portion includes attaching a thin film optical film including a plurality of fine uneven areas to the mold layer.

12. The method according to claim 10, wherein: An air layer is formed by spacing the mold layer and the polarization member apart.

13. The method according to claim 10, further comprising: Before forming the mold layer, a filling layer having a black-based color is stacked to the substrate to absorb external light so as to expose light emitting surfaces of the plurality of micro LEDs.

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