Display device and method for manufacturing same

Abstract

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

Description

Case Analysis

[0001] This application is a divisional application of the invention patent application filed on February 1, 2021, with application number 202180052722.X and title "Display Device and Method for Manufacturing the Display Device". Technical Field

[0002] This disclosure relates to a display device and a method of manufacturing the same. More specifically, this disclosure relates to a display device and a method of manufacturing the same, the display device being configured to reduce the boundary visibility and external light reflectivity of adjacent display modules and to prevent moires from becoming visible on the screen. Background Technology

[0003] In addition to the continued demand for higher brightness, higher resolution and larger size in display devices, the demand for high efficiency and low power consumption is also increasing recently due to the trend of environmentally friendly electronic products.

[0004] Therefore, organic light-emitting diode (OLED) panels have attracted much attention as a new type of display device to replace liquid crystal display (LCD) panels, but problems such as high cost due to low yield, large size and reliability issues still need to be solved.

[0005] As a new product to replace or supplement the above-mentioned products, there is increasing interest in the technology of directly mounting miniature LEDs that emit red, green and blue light onto a substrate to create a panel.

[0006] Display devices can be configured to display images without backlighting by using self-emissive display devices and to represent various colors by operating on a pixel or subpixel basis. Individual pixels or subpixels can be configured for operation controlled by thin-film transistors (TFTs). Summary of the Invention

[0007] [Technical Issues]

[0008] A display device and a method of manufacturing the same are provided, the display device being configured to reduce the boundary visibility and external light reflectivity of adjacent display modules and to prevent ripples from becoming visible from the side surfaces of the display device.

[0009] [Technical Solution]

[0010] According to an embodiment, a display device includes: a substrate having a plurality of self-emissive devices disposed on a front surface of the substrate; a molding layer configured to cover both the front surface of the substrate and the plurality of self-emissive devices, and having an uneven portion formed on the front surface; and a polarizing member spaced apart from the front surface of the molding layer so as not to optically adhere to the molding layer.

[0011] Uneven parts can include multiple irregularly arranged uneven areas.

[0012] An air layer can be disposed between the molding layer and the polarizing member, and the uneven portion can be integrally formed with the molding layer at the surface of the molding layer that contacts the air layer.

[0013] The uneven portion can be a thin-film anti-glare (AG) film or a thin-film optical film with multiple small uneven areas.

[0014] The display device may also include a filler layer configured to fill between a plurality of self-emissive devices, and the filler layer having a black-based color and configured to cover the side surfaces of the plurality of microLEDs. In this case, the filler layer may be configured to cover the front surface of the substrate in addition to the light-emitting surfaces of the plurality of microLEDs.

[0015] Multiple micro-LEDs can be electrically coupled to and physically coupled to the substrate electrode pads of the substrate via an adhesive layer formed of an anisotropic conductive film (ACF) or conductive ink with fine conductive particles.

[0016] Multiple micro-LEDs can be physically coupled to the substrate electrode pads of the substrate through an adhesive layer formed by a non-conductive film (NCF).

[0017] The polarizing component may include a glass substrate and a circularly polarizing layer disposed on the glass substrate.

[0018] According to an embodiment, a method of manufacturing a display device includes: transferring a plurality of microLEDs to a front surface of a substrate; stacking a molding layer on the front surface of the substrate to cover the light-emitting surfaces of the plurality of microLEDs; forming an uneven portion on the molding layer; and configuring a polarizing member to be spaced apart from the front surface of the molding layer so as not to adhere optically to the molding layer.

[0019] Uneven parts can be formed such that multiple uneven areas are irregularly arranged on the molding layer.

[0020] Uneven areas can be integrally formed on the surface of the molding layer using an embossing process.

[0021] Uneven areas can be formed by attaching a thin-film anti-glare (AG) film to the surface of the molding layer, or by attaching a thin-film optical film with multiple small uneven areas.

[0022] The molding layer can be configured such that the transparent resin is formed by a UV-curing molding method.

[0023] An air layer can be formed by separating the molding layer and the polarizing element.

[0024] The manufacturing method may also include stacking a fill layer with a black-based color onto a substrate before forming the molding layer, so as to expose the light-emitting surface of multiple micro-LEDs. Attached Figure Description

[0025] Figure 1 This is a schematic illustration of a front view of a display device according to an embodiment;

[0026] Figure 2 This is a schematic perspective view showing an example of a display portion connected to a plurality of display modules and an external light reflection prevention member disposed on its front side, according to an embodiment;

[0027] Figure 3 It is shown that, according to an embodiment Figure 1 A cross-sectional view of part III shown;

[0028] Figure 4 This shows a front view of a display module according to an embodiment;

[0029] Figure 5 This is a flowchart of a method for manufacturing a display device according to an embodiment;

[0030] Figure 6 This is a cross-sectional view showing an example of a thin-film transistor (TFT) substrate with an insulating layer formed on its front surface according to an embodiment;

[0031] Figure 7 This is a cross-sectional view showing an example of laminating an adhesive layer onto a TFT substrate according to an embodiment;

[0032] Figure 8 This is a cross-sectional view illustrating an example of transferring multiple miniature light-emitting diodes (LEDs) onto a TFT substrate according to an embodiment;

[0033] Figure 9 This is a cross-sectional view showing an example of a filling layer stacked on the front surface of a TFT substrate, in addition to the light-emitting surfaces of a plurality of microLEDs, according to an embodiment;

[0034] Figure 10 This is a cross-sectional view showing an example of a stacked molding layer covering a fill layer and the light-emitting surface of a plurality of microLEDs according to an embodiment;

[0035] Figure 11 This is a cross-sectional view showing an example of forming an uneven portion at the surface of the molded layer according to an embodiment;

[0036] Figure 12 This is a front view showing a display portion coupled with multiple display modules to form a large-screen display according to an embodiment;

[0037] Figure 13 This is a cross-sectional view showing an example of an air layer formed between a display portion and an external light reduction member by providing a polarizing member at a predetermined distance on the front surface of the display portion according to an embodiment;

[0038] Figure 14 This is a flowchart of a method for manufacturing a display device according to another embodiment; and

[0039] Figure 15 This is a cross-sectional view showing a portion of the display module of a display device according to another embodiment. Detailed Implementation

[0040] Various embodiments will now be described in more detail with reference to the accompanying drawings. Various modifications can be made to the embodiments described herein. Specific embodiments are shown in the accompanying drawings and described in detail in the specification. However, the specific embodiments described in the accompanying drawings are merely to aid in understanding the various embodiments. Therefore, the various embodiments disclosed in the accompanying drawings are not intended to limit the scope of this disclosure to the specific embodiments, but should be understood to include all modifications or substitutions encompassed by the technical spirit and scope of the embodiments.

[0041] Various elements may be described using terms including ordinal numbers such as first, second, etc., but these elements are not limited to the terms mentioned above. The terms mentioned above may be used only to distinguish one element from another.

[0042] In this disclosure, it should be understood that terms such as “comprising” or “including” 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 “coupled to” / “coupled to” or “connected to” another element, it should be understood that the particular element may be directly coupled to or connected to that other element, but other elements may be present between them. On the other hand, when a particular element is indicated as “directly coupled to” / “directly coupled to” or “directly connected to” another element, it should be understood that no other elements are present between them.

[0043] In this disclosure, the expression "same" can mean not only a perfect match, but also includes taking into account the degree of difference in the range of processing errors.

[0044] In addition, in describing this disclosure, detailed descriptions of relevant known techniques will be omitted or reduced where it is determined that such detailed descriptions may unnecessarily obscure the spirit of the disclosure.

[0045] The display module can be a display panel equipped with miniature 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 of 100 micrometers or less and can provide better contrast, response time and energy efficiency than liquid crystal display (LCD) panels that require backlighting.

[0046] Both OLEDs and micro-LEDs, as inorganic LEDs, offer excellent energy efficiency, but micro-LEDs boast superior brightness, luminous efficiency, and lifespan compared to OLEDs. Micro-LEDs can be self-emissive semiconductor chips capable of emitting light when powered. They can exhibit 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 higher "brightness per watt" compared to LCD or OLED displays of related technologies. Therefore, compared to LEDs (e.g., exceeding 100 μm in width, length, and height) or OLEDs, micro-LEDs can be configured to achieve the same brightness with approximately half the energy. In addition to the above, micro-LEDs can provide high resolution, excellent color, shadow, and brightness, accurately representing a wide range of colors, and delivering clear images even in bright sunlight. Furthermore, because micro-LEDs are highly resistant to burn-in and do not deform due to minimal heat generation, they can guarantee a long lifespan. Micro LEDs can have a flip-chip structure in which an anode electrode and a cathode electrode are formed on the same first surface, and a light-emitting surface is formed on a second surface located on the opposite side of the first surface on which the electrodes are formed.

[0047] In this disclosure, the substrate may have a TFT layer on its front surface in which thin-film transistor (TFT) circuitry is formed, and a power supply circuit configured to supply power to the TFT circuitry, a data driver, a gate driver, and a timing controller configured to control each driver are disposed on the rear surface. Multiple pixels arranged on the TFT layer can be driven by the TFT circuitry.

[0048] In this disclosure, glass substrates, synthetic resin-based substrates with flexible materials (e.g., polyimide (PI), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), etc.), or ceramic substrates can be used as substrates.

[0049] The TFT layer with TFT circuitry can be disposed on the front surface of the substrate, while the rear surface of the substrate may not have any circuitry. The TFT layer can be integrally formed on the substrate or bonded to a surface of a glass substrate manufactured as a separate film.

[0050] The front surface of the substrate can be divided into an active region and a dummy region. The active region corresponds to the area on the front surface of the substrate occupied by the TFT layer, and the dummy region can be the area on the front surface of the substrate other than the area occupied by the TFT layer.

[0051] The edge region of the substrate can be the outermost region of the glass substrate. Alternatively, the edge region of the substrate can be any region other than the area where the circuitry of the substrate forms. Furthermore, the edge region of the substrate can include portions of the front surface of the substrate adjacent to the side surfaces of the substrate, and portions of the rear surface of the substrate adjacent to the side surfaces of the substrate. The substrate can be formed as a quadrilateral. Specifically, the substrate can be formed as a rectangle or a square. The edge region of the substrate can include at least one of the four sides of the glass substrate.

[0052] The TFT including the TFT layer (or backplane) is not limited to a specific structure or type. For example, in addition to low-temperature polycrystalline silicon TFTs (LTPS TFTs), the TFTs mentioned in this invention can also be implemented using oxide TFTs and Si TFTs (polycrystalline silicon, a-silicon), organic TFTs, graphene TFTs, etc., and can be applied by fabricating only P-type (or N-type) metal-oxide-semiconductor field-effect transistors (MOSFETs) in a Si wafer complementary metal-oxide-semiconductor (CMOS) process.

[0053] The pixel driving method of the display module can be an active matrix (AM) driving method or a passive matrix (PM) driving method. The display module can be configured to form a wiring pattern to which each micro-LED is electrically connected, according to the AM or PM driving method.

[0054] A pixel area can be equipped with multiple Pulse Amplitude Modulation (PAM) control circuits. In this case, each sub-pixel located within a pixel area can be controlled by its corresponding PAM control circuit. Alternatively, a pixel area can be equipped with multiple Pulse Width Modulation (PWM) control circuits. In this case, each sub-pixel located within a pixel area can be controlled by its corresponding PWM control circuit.

[0055] A pixel area can be equipped with both PAM control circuits and PWM control circuits. In this case, some sub-pixels within a pixel area can be controlled by the PAM control circuit, while the remaining sub-pixels can be controlled by the PWM control circuit. Alternatively, each sub-pixel can be controlled by both PAM and PWM control circuits.

[0056] The display module may include multiple side surface wirings of thin film thickness arranged at a certain distance along the side surface of the TFT substrate.

[0057] The display module may include multiple through-wire members that are not exposed to the side surface facing the TFT substrate, in place of side surface wiring exposed to the side surface facing the TFT substrate. Therefore, by minimizing the dummy area and maximizing the active area at the front surface of the TFT substrate, the bezel can be made borderless, and the mounting density of micro-LEDs relative to the display module can be increased.

[0058] By providing multiple display modules in a borderless form through coupling, a large-size multi-display device that maximizes the active area can be provided when coupling multiple display devices. In this case, each display module can be shaped to maintain the spacing between adjacent pixels of the display module in the same way as the spacing between pixels in a single display module, based on minimizing the dummy area. Therefore, this can be a method to make the seams invisible at the coupling portions between the display modules.

[0059] A large-screen display can be formed by connecting multiple display modules, and polarizing members can be disposed on the front side of the display to reduce boundary visibility, which makes the seams visible at the boundaries of the individual display modules, and to reduce external light reflectivity. The polarizing members may include, for example, transparent glass and a circularly polarizing layer stacked on the front surface of the transparent glass. In this case, the polarizing members can be spaced apart on the front side of the display to form an air layer of predetermined thickness between the display and the polarizing members.

[0060] The driving circuit can be implemented by a micro-integrated circuit (IC) configured to control the driving of at least 2n pixels located in the pixel area. Based on applying the micro-IC to the display module instead of the TFT, only a channel layer connecting the micro-IC to the individual micro-LEDs can be formed at the TFT layer (or backplane).

[0061] Display modules 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. They can also be used as multiple components in a matrix type in display devices, such as, but not limited to, monitors for personal computers, high-resolution televisions (TVs) and signage (or digital signage), electronic displays, etc.

[0062] The display module according to an embodiment will now be described with reference to the accompanying drawings.

[0063] Figure 1 This is a schematic illustration of a front view of a display device according to an embodiment. Figure 2 This is a schematic perspective view showing an example of a display section in which multiple display modules are connected and a polarizing member disposed on its front side. Figure 3 It shows Figure 1 The cross-sectional view of part III shown.

[0064] 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-size screen, and polarizing members 90 disposed at predetermined distances on the front side of the display portion 100.

[0065] The display portion 100 can be formed by using a plurality of display modules 10 having a certain size and being continuously coupled in the row and column directions. In this case, the display modules adjacent to each other can be physically coupled and electrically coupled.

[0066] Depending on the arrangement of multiple display modules 10, the display portion 100 can be formed as a square with the same width and length ratio or as a rectangle with different width and length ratios. The width and length dimensions of the polarizing member 90 can correspond to the width and length dimensions of the corresponding display portion 100.

[0067] The polarizing member 90 can be disposed on the front side of the display section to reduce the boundary visibility that makes the seam visible at the boundary of each display module and to reduce the external light reflectivity.

[0068] Reference Figure 3 The polarizing member 90 can be generally formed in the shape of a plate and can include a transparent glass substrate 91 and a circularly polarizing layer 93 stacked on one surface of the glass substrate 91.

[0069] Based on its black-based color, the circular polarization layer 93 can reduce the boundary visibility that makes the seam visible at the boundaries of each display module, and reduce reflectivity by absorbing external light.

[0070] The polarizing members 90 can be positioned at a predetermined distance on the front side of the display portion 100. Therefore, an air layer 80 of predetermined thickness can be formed between the polarizing members 90 and the display portion 100.

[0071] The polarizing member 90 can be supported by the frame member 7 surrounding the exterior of the display portion 100. Therefore, the polarizing member 90 can be configured to be spaced apart from the display portion 100 by a predetermined distance.

[0072] Although not shown in the accompanying drawings, the bezel member 7 can be omitted from the display device 1. In this case, the polarizing member 90 can be positioned spaced apart from the display portion 100 by various support structures. For example, to position the polarizing member 90 spaced apart from the display portion 100, multiple spacers can be provided between the polarizing member 90 and the display portion 100. In this case, the spacers preferably have a transparency that does not reduce the luminous intensity of the micro-LEDs and are positioned at points that have no or minimal impact on luminous intensity.

[0073] As described above, by forming an air layer 80 between the polarizing member 90 and the display portion 100, problems related to the reflectivity and thickness of the display module 10 that may occur can be solved.

[0074] For example, by stacking a layer on the front surface of the display module 10 with multiple uneven regions (i.e., an uneven layer) to address the ripples visible from the side surface of the display device 10, the reduction in visibility may be significant due to the increased reflectivity of the uneven regions. Furthermore, stacking the layers in such a manner that they contact the front surface of the display module 10 may increase the thickness of the display module 10, potentially increasing light loss at the ends of the display module 10, and causing color seams at the ends of the display module 10 to not exhibit the desired color.

[0075] Based on the thickness of the air layer 80 that separates the polarizing 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 polarizing member 90, and the aforementioned related problems can be fundamentally solved.

[0076] Figure 4 This shows a front view of a display module.

[0077] 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.

[0078] The TFT substrate 20 may include a glass substrate and a TFT layer on the front surface of the glass substrate that includes TFT circuitry. Additionally, the TFT substrate 20 may be disposed on the rear surface of the glass substrate and include multiple side surface wirings 15 electrically coupled to the TFT circuitry and circuitry configured to supply power to the TFT circuitry and electrically coupled to a separate control substrate.

[0079] The TFT substrate 20 may include an active region 20a for displaying images and a dummy region 20b for not displaying images on its front surface.

[0080] The active region 20a can be divided into multiple pixel regions, each containing multiple pixels. These multiple pixel regions can be divided in various ways, and for example, they can be divided as follows: Figure 4 The matrix form in the image. Each pixel region may include a subpixel region in which multiple subpixels are installed and a pixel circuit region in which pixel circuits for driving each subpixel are provided.

[0081] Multiple microLEDs 51, 52, and 53 can be light-emitting devices for displaying images. Multiple microLEDs 51, 52, and 53 can be transferred to the pixel circuit region of the TFT layer, and the electrode pads of each microLED can be electrically coupled to the substrate electrode pads 21, 22, and 23 formed in the sub-pixel region of the TFT layer, respectively. Figure 3 Considering the arrangement of at least three microLEDs 51, 52, and 53 located in each pixel region, a common electrode pad can be formed in a straight line. Multiple microLEDs can be subpixels forming a single pixel. In this disclosure, a microLED can refer to a subpixel, and the related terms are used interchangeably.

[0082] Three red, green, and blue micro-LEDs 51, 52, and 53 are described as forming a pixel, but the embodiments are not limited to this, and any number of micro-LEDs can form a pixel.

[0083] The pixel driving method of the display module 10 according to the embodiment can be an active matrix (AM) driving method or a passive matrix (PM) driving method. The display module 10 can be configured to form a wiring pattern to which each microLED is electrically coupled according to the AM driving method or the PM driving method.

[0084] The dummy region 20b may be included in the edge region of the glass substrate. For example, the edge region of this disclosure may be a region in which multiple side surface wirings 15 are formed, and may include the portion of the front surface of the TFT substrate 20 adjacent to the side surface 20c of the TFT substrate 20, and the portion of the rear surface of the TFT substrate 20 adjacent to the side surface 20c of the TFT substrate 20.

[0085] Reference Figure 3 The display module 10 may have multiple substrate electrode pads 21, 22, and 23 formed on the front surface of the TFT substrate 20. The multiple substrate electrode pads 21, 22, and 23 may be electrically connected to multiple micro-LEDs 51, 52, and 53. Therefore, the multiple micro-LEDs 51, 52, and 53 may be coupled to the TFT circuit of the TFT layer through the multiple substrate electrode pads 21, 22, and 23.

[0086] The display module 10 has been described as including a TFT substrate 20, but is not limited thereto, and a substrate without a TFT layer including TFT circuitry can be used. In this case, the driving circuitry disposed on the rear surface of the TFT substrate 20 can be implemented by a micro-integrated circuit (IC) that controls the driving of at least 2n pixels disposed in the pixel area. Based on the application of the micro-IC to the display module 10 as described above, a channel layer connecting the micro-IC to each micro-LED can be formed on the TFT layer instead of the TFT.

[0087] The display module 10 can be configured such that the insulating layer 30, the adhesive layer 40, the filler layer 60, and the molding layer 70 are sequentially stacked on the front surface of the TFT substrate 20. (Refer to the following...) Figure 3 Describe the individual layers stacked on the front surface of the TFT substrate 20.

[0088] The insulating layer 30 can be stacked on the front surface of the TFT substrate 20 to protect the TFT circuitry 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 can be formed by applying, for example, photoimageable solder resist (PSR) ink.

[0089] The adhesive layer 40 can be stacked on the front surface of the TFT substrate 20 to secure multiple microLEDs 51, 52, and 53 to the TFT substrate 20. In this case, for ease of handling, the adhesive layer 40 can be stacked on the front surface of the TFT substrate 20 to cover the entire front surface of the TFT substrate 20.

[0090] The adhesive layer 40 can be an anisotropic conductive film (ACF) or a non-conductive film (NCF).

[0091] When using ACF as the adhesive layer 40, to avoid increasing the overall manufacturing cost of the display device due to the high material cost of ACF, conductive ink comprising multiple 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 and the area surrounding the substrate electrode pads 21, 22, and 23 in the entire front surface region of the TFT substrate 20.

[0092] Each micro LED can have a flip-chip structure, wherein the anode electrode and the cathode electrode are formed on the same first surface S1, and the light-emitting surface is formed on the second surface S2, which is located on the opposite side of the first surface S1 on which the electrodes are formed.

[0093] After being transferred to the TFT substrate 20, multiple micro-LEDs 51, 52 and 53 can be electrically coupled to the corresponding substrate electrode pads 21, 22 and 23 by a thermo-pressing process, and can be stably fixed to the TFT substrate 20 by an adhesive layer 40.

[0094] The filler layer 60 can be stacked on the front surface of the TFT substrate 20 and can cover the entire front surface of the TFT substrate 20 except for the light-emitting surfaces S2 of the multiple micro-LEDs 51, 52 and 53.

[0095] The filler layer 60 can be formed of an insulating material and can absorb light emitted from the side and back surfaces S1 of the multiple micro-LEDs 51, 52, and 53 based on its black color, and prevent crosstalk between adjacent micro-LEDs. Therefore, since the filler layer 60 can act as a black matrix, the display module 10 does not need to form a separate black matrix.

[0096] The molding layer 70 can cover the filler layer 60 and the light-emitting surfaces S2 of the multiple micro-LEDs 51, 52 and 53. The molding layer 70 can be a transparent resin and can be formed by an ultraviolet (UV) curing molding method.

[0097] The molding layer 70 may have uneven portions 71 formed over its entire surface. When the screen of the display device 1 is viewed at an angle from the side surface, the uneven portions 71 can prevent ripples from becoming visible.

[0098] The uneven portion 71 may include a plurality of uneven portions irregularly arranged by embossing the surface of the molding layer 70. Therefore, since the uneven portion 71 is integrally formed with the molding layer 70, rather than being stacked as a separate layer onto the molding layer 70, an increase in the thickness of the display module 10 can be prevented. Thus, color seams can be prevented from becoming visible at the ends of the display module 10 due to an increase in the thickness of the display module 10.

[0099] Because the polarizing members 90 are positioned at a predetermined distance on the front side of the display portion 100, the thickness of the display module 10 does not increase due to the polarizing members 90. Therefore, in this disclosure, when the anti-glare (AG) film of the thin film is stacked on the molding layer 70 to replace 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. Alternatively, an optical film with fine uneven portions can be formed by laminating the molding layer 70 with a pressure-sensitive adhesive (PSA) to replace the uneven portion 71.

[0100] The following will refer to Figures 5 to 13 The manufacturing process of the display device 1 according to an embodiment of the present disclosure is described.

[0101] Figure 5 This is a flowchart illustrating the process of manufacturing a display device according to an embodiment, and Figure 6 This is a cross-sectional view of a TFT substrate with an insulating layer formed on its front surface.

[0102] Reference Figure 6 The insulating layer 30 can be formed on the glass substrate, and the TFT substrate 20 on which the TFT layer is formed is formed on the glass substrate.

[0103] Multiple substrate electrode pads 21, 22 and 23, to which the micro-LEDs 51, 52 and 53 transferred to the TFT substrate are respectively connected, can be arranged on the front surface of the TFT substrate 20.

[0104] The insulating layer 30 can cover the entire front surface area of ​​the TFT substrate 20, except for the area where multiple substrate electrode pads 21, 22 and 23 are provided.

[0105] An insulating layer 30 can be formed on the front surface of the TFT substrate 20 by sequentially performing an exposure and curing process after applying an insulating material (e.g., photoimageable solder resist (PSR) ink).

[0106] Figure 7 This is a cross-sectional view showing an example of laminating an adhesive layer onto a TFT substrate.

[0107] Reference Figure 7 The adhesive layer 40 can be attached to the front surface of the TFT substrate 20 by lamination. Anisotropic conductive film (ACF) or non-conductive film (NCF) can be used as the adhesive layer 40.

[0108] The adhesive layer 40 can be selectively stacked only on the desired area, rather than attached to the entire front surface area of ​​the TFT substrate 20. In this case, the adhesive layer 40 can be formed by using a conductive ink comprising multiple nano-conductive particles.

[0109] As described above, when the adhesive layer 40 is formed with conductive ink, the adhesive layer 40 can be stacked by selectively spraying 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 area surrounding the substrate electrode pads 21, 22 and 23.

[0110] Figure 8 This is a cross-sectional view showing an example of transferring multiple micro-LEDs onto a TFT substrate.

[0111] Reference Figure 8 Multiple micro-LEDs 51, 52 and 53 can be transferred to the TFT substrate 20 (S11).

[0112] Multiple microLEDs grown from an epitaxial substrate (not shown) can be separated from the epitaxial substrate by laser lift-off (LLO) and arranged on a relay substrate (not shown). The microLEDs arranged adjacent to each other on the relay substrate can maintain a first chip spacing in the X-axis direction (or row direction) and a second chip spacing in the Y-axis direction (or column direction).

[0113] Multiple microLEDs 51, 52 and 53 transferred to the relay substrate can be transferred to the TFT substrate 20 by transfer processes (e.g. laser transfer, roll-up transfer, and pick-and-place transfer).

[0114] When transferred to the TFT substrate 20, multiple microLEDs 51, 52 and 53 can be transferred to the TFT substrate 20 with chip pitches different from the corresponding first chip pitch and second chip pitch on the relay substrate.

[0115] Multiple microLEDs 51, 52, and 53 transferred to the TFT substrate 20 can be respectively disposed at corresponding substrate electrode pads 21, 22, and 23. In this state, the multiple microLEDs 51, 52, and 53 can be hot-pressed toward the TFT substrate 20 using a pressing member (not shown). In this case, the die supporting the TFT substrate 20 (not shown) and the pressing member can each be equipped with a heater (e.g., a sheath heater, etc.).

[0116] Based on the fact that a portion of the adhesive layer 40 (e.g., the portion located between the plurality of microLEDs and the substrate electrode pads) melts under the heat generated during hot pressing, the plurality of microLEDs 51, 52, and 53 can be stably and physically fixed to the respective substrate electrode pads 21, 22, and 23 of the TFT substrate 20. In this case, the plurality of microLEDs 51, 52, and 53 can contact and be electrically coupled to the electrode pads 21, 22, and 23 by the pressing force of the pressing member.

[0117] Figure 9 This is a cross-sectional view showing an example of a filling layer stacked on the front surface of a TFT substrate, in addition to the light-emitting surfaces of multiple micro-LEDs.

[0118] Reference Figure 9 A filler layer can be formed by coating an insulating material capable of absorbing light onto the front surface of the TFT substrate 20 to which multiple micro-LEDs 51, 52 and 53 are transferred (S12).

[0119] The filler layer 60 can be formed in a black-based color, making light absorption possible. The filler layer 60 can be applied to cover the entire front surface of the TFT substrate 20 except for the light-emitting surfaces S2 of the multiple micro-LEDs 51, 52 and 53.

[0120] The thickness of the filler layer 60 may be approximately corresponding to the thickness of the light-emitting surfaces S2 of the multiple microLEDs 51, 52 and 53 from the surface of the adhesive layer 40 (e.g., the boundary between the adhesive layer 40 and the filler layer 60).

[0121] In this configuration, based on the side surfaces of the plurality of microLEDs 51, 52, and 53 formed in all directions, the filling layer 60 can absorb light emitted from the back surface S1 of the plurality of microLEDs 51, 52, and 53 and prevent crosstalk between adjacent microLEDs. As described above, the filling layer 60 can function as a black matrix.

[0122] Figure 10 This is a cross-sectional view showing an example of a stacked molded layer covering a filler layer and the light-emitting surface of multiple microLEDs. Figure 11 This is a cross-sectional view showing an example of an uneven portion formed on the surface of the molded layer.

[0123] Reference Figure 10 The molding layer 70 can be stacked over the entire front surface area of ​​the TFT substrate 20 (S13).

[0124] The molding layer 70 can be formed by UV curing molding, wherein a resin covering the filler layer 60 and the light-emitting surfaces of the micro-LEDs 51, 52 and 53 with a degree of transparency such that the light emitted from the light-emitting surfaces of the multiple micro-LEDs 51, 52 and 53 meets the required light amount.

[0125] Reference Figure 11 The surface of the molding layer 70 can be embossed, and an uneven portion 71 (S14) including a plurality of uneven portions irregularly arranged over the entire surface of the molding layer 70 can be formed.

[0126] Since the uneven portion 71 is formed by processing the surface of the molding layer 70, the thickness of the display module 10 can be maintained without increasing it. The uneven portion 71 can be formed relative to the entire surface area of ​​the molding layer 70.

[0127] Based on the uneven portion 71 formed on the surface of the molding layer 70 as described above, when a viewer tilts the screen of the display device 1 from the side surface of the display device 1 in an oblique direction, the ripples can be prevented from becoming visible.

[0128] By replacing the uneven portion 71 with an anti-glare (AG) film (not shown) stacked on the molding layer 70, the thickness increase of the display module 10 can be minimized, and the ripples can be prevented from becoming visible. Alternatively, an optical film with fine uneven portions can be formed by laminating the molding layer 70 with a pressure-sensitive adhesive (PSA) to replace the uneven portion 71.

[0129] Figure 12 This is a front view showing a section where multiple display modules are connected to achieve a large-screen display. Figure 13This is a cross-sectional view showing an example of an air layer formed between the display portion and the polarizing member by setting a polarizing member at a predetermined distance on the front surface of the display portion.

[0130] Reference Figure 12 The display module 10 formed by the above sequential process can be used to form a display section 100 by continuously coupling multiple modules in the row and column directions.

[0131] Reference Figure 13 The front of the display portion 100 may be provided with polarizing members 90 spaced apart at a preset distance (S15).

[0132] The polarization member 90 can prevent the boundary between the display modules 10 coupled to each other from becoming visible and reduce the external light reflectivity by using a circularly polarized layer 93 with a black-based color.

[0133] The polarizing member 90 can be provided by the frame member 7 (see reference) disposed outside the display portion 100. Figure 1 To maintain the spacing distance, an air layer 80 can be formed between the polarizing member 90 and the display portion 100. Therefore, the molding layer 70 and the polarizing member 90 of each display module 10 can be optically separated from each other.

[0134] The light emitted from the multiple micro-LEDs arranged in the various display modules 10 of the display section 100 can pass through the air layer 80 without refraction and can be completely irradiated to the outside of the display device 1 by the polarizing member 90.

[0135] As described above, since the polarizing members 90 are spaced apart to create air gaps relative to each display portion 100, the thickness of the display module 10 can be maintained without increasing it. Therefore, the aforementioned problem of increasing the thickness of the display module 10 can be fundamentally prevented.

[0136] The display device 1 can be configured such that the bezel member 7 is omitted, and in this case, the polarizing member 90 can be spaced apart from the display portion 100 by various support structures not shown in the figures.

[0137] For example, a transparent spacer (not shown) may be disposed between the polarizing member 90 and the display portion 100. In this case, the spacer is preferably formed of a material with transparency that does not reduce the luminous output of the micro-LEDs and minimizes light loss or reflection. Furthermore, the spacer is preferably disposed at points that do not affect or minimize the luminous output of the micro-LEDs.

[0138] Figure 14 This is a cross-sectional view showing a portion of the display module of a display device according to another embodiment, and Figure 15This is a flowchart illustrating the process of manufacturing a display device according to another embodiment.

[0139] Display device 1a according to another embodiment of this disclosure may be largely similar in structure to display device 1 described above, and the same reference numerals may be applied to the same elements. Display device 1a may be described as follows, but the description of elements that are the same as those in display device 1 described above may be omitted.

[0140] Reference Figure 14 The adhesive layer 40 of the display device 1 can be omitted from the display device 1 (see reference). Figure 3 In this case, the display device 1a may include a welding member 41 that can replace the adhesive layer 40. The welding member 41 may be a solder ball or a micro bump.

[0141] The welding component 41 can be patterned on the substrate electrode pads 21, 22, and 23 via a reflow process. Multiple micro-LEDs 51, 52, and 53 can be electrically and physically coupled to the substrate electrode pads 21, 22, and 23 via the welding component 41 through a thermocompression process after the transfer process.

[0142] Unlike the display device 1 described above, the display device 1a may omit the filler layer 60 (see reference). Figure 3 In this case, the molding layer 70 can be filled between multiple micro-LEDs 51, 52 and 53.

[0143] Reference Figure 15 According to another embodiment, the display device 1a can be manufactured using a slightly different process than the display device 1 described above.

[0144] First, an insulating layer 30 can be formed in the remaining areas of the entire front surface region of the TFT substrate 20, except for the areas where multiple substrate electrode pads 21, 22 and 23 are provided.

[0145] The welding component 41 can be applied to the various substrate electrode pads 21, 22 and 23 by a reflow process.

[0146] Then, in operation S21, a plurality of microLEDs 51, 52, and 53 can be transferred to the TFT substrate 20. The plurality of microLEDs 51, 52, and 53 can be hot-pressed toward the TFT substrate 20 in this state using a pressing member. Therefore, due to the melting of the welding member 41 by the heat generated during the hot pressing, the plurality of microLEDs 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.

[0147] Then, a molding layer 70 can be stacked over 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 can be formed over the entire surface of the molding layer (S23).

[0148] In this case, the lamination process of the AG film of the thin film can be performed at the molding layer 70 to replace the uneven portion 71.

[0149] After multiple display modules 10 formed by the above process are coupled continuously in the row and column directions, polarization members 90 can be provided at a preset distance interval on the front side of the display portion 100 (S24).

[0150] The display device 1a according to another embodiment described above can, like the display device 1 described above, not only reduce the boundary visibility and external light reflectivity of adjacent display modules 10, but also prevent ripples from becoming visible from the side surface of the display device 1a.

[0151] Various embodiments of this disclosure have been described above separately and individually, but each embodiment is not necessarily implemented alone, and the configuration and operation of each embodiment can be implemented in combination with at least one other embodiment.

[0152] Although this 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 and not restrictive. Those skilled in the art will understand that various changes in form and detail may be made therein without departing from the true spirit and full scope of this disclosure (including the appended claims and their equivalents).

[0153] [Industrial Applicability]

[0154] This disclosure relates to a display device and a method for manufacturing the same.

Claims

1. A display device, comprising: Substrate; Multiple self-emissive devices are disposed on the front surface of the substrate; A molding layer is configured to cover at least a portion of the front surface of the substrate and to contact the light-emitting surface of at least one of the plurality of self-emissive devices, the molding layer including at least one uneven portion; as well as An optical layer is spaced apart from the front surface of the molding layer so as not to adhere optically to the molding layer.

2. The display device according to claim 1, wherein, The optical layer includes polarizing components.

3. The display device according to claim 2, wherein, The at least one uneven portion includes multiple uneven areas arranged irregularly.

4. The display device according to claim 2, further comprising an air layer disposed between the molding layer and the polarizing member, and in, The at least one uneven portion is integrally formed with the molding layer at the surface of the molding layer that contacts the air layer.

5. The display device according to claim 2, wherein, The at least one uneven portion includes a thin-film anti-glare AG film.

6. The display device according to claim 2, wherein, The at least one uneven portion includes a thin-film optical film having multiple small uneven regions formed thereon.

7. The display device according to claim 2, further comprising a filling layer disposed between the plurality of self-emissive devices, in, The filling layer comprises a black-based color and is configured to cover the side surfaces of the plurality of self-emissive devices.

8. The display device according to claim 7, wherein, The filling layer is configured to cover the front surface of the substrate, excluding at least one light-emitting surface of the plurality of self-emissive devices.

9. The display device according to claim 7, wherein, The plurality of self-emissive devices are electrically coupled to and physically coupled to the substrate electrode pads of the substrate via an adhesive layer, wherein the adhesive layer comprises an anisotropic conductive film (ACF) or conductive ink containing fine conductive particles.

10. The display device according to claim 7, wherein, The plurality of self-emissive devices are physically coupled to the substrate electrode pads of the substrate via an adhesive layer, the adhesive layer comprising a non-conductive film NCF.

11. The display device according to claim 2, wherein, The polarization component includes: Glass substrate; and A circular polarizing layer is disposed on the glass substrate.

12. The display device according to claim 11, wherein, The circular polarization layer is based on a color based on black.

13. The display device according to claim 1, further comprising: Multiple substrate electrode pads are disposed on the front surface of the substrate; as well as The welding component is located on the front surface of the plurality of substrate electrode pads. Each of the plurality of self-emissive devices is electrically connected to and physically connected to the plurality of substrate electrode pads via the welding component.

14. The display device according to claim 13, wherein, The welding components include welding balls or micro bumps.

15. The display device according to claim 1, wherein, The molding layer is filled between the plurality of self-emissive devices.

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