Transparent display device and repair method thereof

Abstract

Provided are a transparent display device and a repair method of a transparent display device. The transparent display device includes: a lower substrate; a dam structure formed along an edge part of the lower substrate and including a silicon-based optical transparent resin; a circuit wire arranged on the lower substrate; an insulating layer formed on the lower substrate to cover the circuit wire; light emitting elements mounted on the insulating layer and connected to the circuit wire; a protective layer formed on the insulating layer to cover the light emitting elements and including a silicon-based optical transparent resin; and an upper substrate attached to the dam structure and the protective layer.

Description

Transparent display device and repair method thereof

[0001] The present invention relates to a transparent display device and a method for repairing the same. More specifically, it relates to a transparent display device comprising a transparent substrate and light-emitting elements and a method for repairing the same.

[0002]

[0003] For example, it is applied to Light Emitting Diode (LED) display panels and is widely utilized in the fields of advertising videos and media art. As an eco-friendly component, LEDs provide high response speed and high-brightness color reproduction. Furthermore, brightness and color temperature can be controlled by adjusting the light output of red, green, and blue LEDs, and display devices can be manufactured in a compact size by assembling multiple LEDs into a single module or panel.

[0004] A transparent display device may include a transparent substrate and a plurality of LED elements arranged on the transparent substrate. If a defect occurs in one or some of the LED elements among the plurality of LED elements, a repair process may be required to separate the transparent substrate and separate the LED elements fixed within the insulating layer / point adhesive layer.

[0005] However, the repair process may not be substantially implemented due to the adhesion of the insulating layer / point adhesive layer. In this case, the inefficiency of replacing the entire transparent display device may occur.

[0006]

[0007] One objective of the present invention is to provide a transparent display device having improved operational reliability and process efficiency.

[0008] One objective of the present invention is to provide a repair method for a transparent display device having improved operational reliability and process efficiency.

[0009]

[0010] 1. A transparent display device comprising: a lower substrate; a dam structure formed along the outer edge of the lower substrate and comprising a silicon-based optically transparent resin; circuit wiring arranged on the lower substrate; an insulating layer formed on the lower substrate and covering the circuit wiring; light-emitting elements mounted on the insulating layer and connected to the circuit wiring; a protective layer formed on the insulating layer and covering the light-emitting elements and comprising a silicon-based optically transparent resin; and an upper substrate attached to the dam structure and the protective layer.

[0011] 2. A transparent display device according to 1, wherein the Shore A hardness of the protective layer is 40 to 65.

[0012] 3. A transparent display device according to 2, wherein the Shore A hardness of the protective layer is 50 to 65.

[0013] 4. A transparent display device according to 1 above, wherein the penetration hardness of the protective layer measured by indentation at 25°C according to the ASTM D1321 standard is 5 dmm to 15 dmm.

[0014] 5. A transparent display device according to 4, wherein the penetration hardness of the protective layer is 8 dmm to 12 dmm.

[0015] 6. A transparent display device according to 4, wherein the measured value of the penetration hardness of the dam structure is greater than the measured value of the penetration hardness of the protective layer.

[0016] 7. A transparent display device according to 6, wherein the penetration hardness of the dam structure is 16 dmm to 25 dmm.

[0017] 8. A transparent display device according to 1, wherein the protective layer comprises a first protective layer formed on the insulating layer to cover the light-emitting element and a second protective layer formed on the first protective layer.

[0018] 9. A transparent display device according to 8, wherein each of the first protective layer and the second protective layer has a Shore A hardness in the range of 40 to 65.

[0019] 10. A transparent display device according to 8, wherein each of the first protective layer and the second protective layer is measured by indentation at 25°C according to ASTM D1321 standard and has a penetration hardness in the range of 5 dmm to 15 dmm.

[0020] 11. A transparent display device according to 8, wherein the Shore A hardness of the first protective layer is 40 to 65, and the penetration hardness of the second protective layer, measured by indentation at 25°C according to ASTM D1321 standard, is 5 dmm to 15 dmm.

[0021] 12. A transparent display device according to 8, wherein the penetration hardness of the first protective layer measured by indentation at 25°C according to the ASTM D1321 standard is 5 dmm to 15 dmm, and the Shore A hardness of the second protective layer is 40 to 65.

[0022] 13. A transparent display device according to 8, wherein the thickness of the first protective layer is greater than the thickness of the second protective layer.

[0023] 14. The transparent display device according to 1, wherein the transparent display device comprises a plurality of light-emitting element unit sheets each including the lower substrate, the circuit wiring, the insulating layer, the light-emitting element, and the protective layer, and the dam structure covers the boundary portions of adjacent light-emitting element unit sheets.

[0024] 15. A transparent display device according to 14, wherein a plurality of light-emitting elements are arranged in a column direction to define a column of light-emitting elements, each of the light-emitting element unit sheets includes the columns of light-emitting elements arranged repeatedly in a row direction, and the dam structure covers at least partially the light-emitting elements included in the columns of light-emitting elements belonging to different light-emitting element unit sheets adjacent in the row direction.

[0025] 16. A repair method for a transparent display device comprising: a step of detecting a defective light-emitting element among the light-emitting elements of the transparent display device described above; a step of peeling the upper substrate from the dam structure and the protective layer; a step of removing the defective light-emitting element from the protective layer; a step of mounting a normal light-emitting element in the space where the defective light-emitting element was removed; and a step of reattaching the upper substrate.

[0026] 17. A method for repairing a transparent display device according to 16, further comprising the step of surface treating the protective layer after the step of mounting the normal light-emitting element.

[0027] 18. A method for repairing a transparent display device according to 16, further comprising the step of adding a silicon-based optically transparent resin on the protective layer after the step of mounting the normal light-emitting element.

[0028]

[0029] In a transparent display device according to embodiments of the present invention, an encapsulation layer covering wiring layers and light-emitting elements can be formed using a silicone-based pressure-sensitive adhesive resin. The silicone-based pressure-sensitive adhesive resin may have low hardness and high release properties. Accordingly, the upper substrate can be easily separated from the encapsulation layer. Therefore, a repair process including replacing defective light-emitting elements, refilling the encapsulation layer, and reattaching the upper substrate can be easily performed.

[0030] In some embodiments, the encapsulation layer may include a multilayer structure formed of a silicone-based pressure-sensitive adhesive resin. The hardness of the upper encapsulation layer of the multilayer structure may be relatively increased to further enhance stability against external impact and the efficiency of the repair process.

[0031] In some embodiments, a dam structure including a silicone-based pressure-sensitive adhesive resin can be formed on the outer edge of the lower substrate. Accordingly, the detachment of the upper substrate can be implemented more easily, and the sealing stability of the transparent display device can be secured.

[0032]

[0033] FIGS. 1 and FIGS. 2 are a schematic plan view and a cross-sectional view, respectively, showing a transparent display device according to exemplary embodiments.

[0034] FIG. 3 is a schematic cross-sectional view showing a transparent display device according to some exemplary embodiments.

[0035] FIG. 4 is a schematic plan view showing a transparent display device according to exemplary embodiments.

[0036] FIG. 5 is a schematic partial enlarged plan view showing a transparent display device according to some exemplary embodiments.

[0037] FIGS. 6 to 11 are schematic plan and cross-sectional views illustrating a repair method for a transparent display device according to exemplary embodiments.

[0038]

[0039] Embodiments of the present invention provide a transparent display device comprising a light-emitting element and a pressure-adhesive encapsulation layer. Embodiments of the present invention provide a method for repairing the transparent display device.

[0040] Embodiments of the present invention will be described in more detail below with reference to the drawings. However, the following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the aforementioned description; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0041] The terms used in this application, such as "first," "second," "upper," "lower," "upper surface," and "lower surface," do not specify absolute positions but are used to distinguish different configurations or to differentiate relative positions between configurations.

[0042] The sizes of the configurations / structures depicted in the attached drawings may be exaggerated for convenience of explanation and are not limited to the sizes depicted in the drawings.

[0043] In the drawings below, the first direction and the second direction may refer to two directions that are parallel to the upper surface of the substrate (100, 170) and perpendicular to each other. For example, the first direction and the second direction may be the width direction and the length direction of the transparent display device, respectively. The third direction may refer to a direction that is perpendicular to the upper surface of the substrate (100, 170) and perpendicular to the first direction and the second direction. The third direction may be the thickness direction of the transparent display device.

[0044] FIGS. 1 and FIGS. 2 are a schematic plan view and a cross-sectional view, respectively, illustrating a transparent display device according to exemplary embodiments. For example, FIG. 2 is a cross-sectional view cut along the line II' of FIG. 1 in the thickness direction.

[0045] Referring to FIG. 1, a transparent display device may include a plurality of light-emitting element rows (LC) disposed on a lower substrate (100). Each light-emitting element row (LC) extends in the second direction, and a plurality of light-emitting element rows (LC) may be repeatedly arranged along the first direction.

[0046] The light-emitting element column (LC) may include a circuit wiring (120) and a plurality of light-emitting elements (140) connected to the circuit wiring (120).

[0047] The circuit wiring (120) may include a driving wiring and data wiring (126) including a first driving wiring (122) and a second driving wiring (124). Either of the first driving wiring (122) and the second driving wiring (124) may be provided as a driving voltage supply wiring, and the other may be provided as a ground voltage supply wiring.

[0048] For example, the first drive wiring (122) and the second drive wiring (124) may each be provided as a drive voltage supply wiring and a ground voltage supply wiring.

[0049] The first driving wire (122) and the second driving wire (124) extend parallel to each other, and when observed in a planar direction, a plurality of light-emitting elements (140) can be arranged along the second direction between the first driving wire (122) and the second driving wire (124).

[0050] The light-emitting element (140) includes terminals connected to each of the first driving wire (122) and the second driving wire (124), and the terminals may be connected to a connecting wire (125) extending from the first driving wire (122) and the second driving wire (124).

[0051] The data wiring (126) extends in the second direction, and a plurality of light-emitting elements (140) can be connected in series through the data wiring (126). For example, the light-emitting element (140) includes an input terminal and an output terminal into which a driving signal is input from the data wiring (126), and the data wiring (126) can be extended from the output terminal to be connected to the input terminal of an adjacent light-emitting element (140).

[0052] According to exemplary embodiments, a dam structure (160) may be disposed on the outer or peripheral portion of the lower substrate (100). In some embodiments, the dam structure (160) may extend continuously along the outer perimeter of the lower substrate (100).

[0053] In FIG. 1, the ends of the rows of light-emitting elements (LC) are shown separated from each other by being covered by a dam structure (160), but wiring can be further extended from the ends to be connected to a power source or an integrated circuit chip.

[0054] Referring to FIG. 2, the circuit wiring (120) can be attached to the upper surface of the lower substrate (100) through the adhesive layer (110).

[0055] The lower substrate (100) comprises a polyester resin such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polyethylene ether phthalate, polyethylene phthalate, polybutylene phthalate, polybutylene terephthalate; a cellulose resin such as diacetylcellulose, triacetylcellulose; a polycarbonate resin; an acrylic resin such as polyacrylate, polymethyl acrylate, polymethyl methacrylate, polyethyl acrylate, polyethyl methacrylate; a styrene resin such as polystyrene, acrylonitrile-styrene copolymer; a polyolefin resin such as polyethylene, polypropylene, cycloolefin, a polyolefin having a cyclo- or norbornene structure, or an ethylene-propylene copolymer; a vinyl chloride resin such as polyvinyl chloride, polyvinylidene chloride; and an amide resin such as nylon, aromatic polyamide. A transparent resin substrate may be included, comprising imide-based resins such as polyimide and polyetherimide; polysulfone-based resins, polyethersulfone-based resins; sulfone-based resins; polyetheretherketone-based resins; polyphenylene sulfide-based resins; vinyl alcohol-based resins; vinylidene chloride-based resins; vinyl butyral-based resins; allylate-based resins; polyoxymethylene-based resins; epoxy-based resins; urethane-based or acrylicurethane-based resins; silicone-based resins, etc.

[0056] The lower substrate (100) may include a glass substrate.

[0057] For example, a metal foil or a metal sheet can be attached to a lower substrate (100) through a point adhesive layer (110). Subsequently, the metal foil or metal sheet can be patterned through an etching process to form circuit wiring (120).

[0058] The circuit wiring (120) may comprise silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), tin (Sn), molybdenum (Mo), calcium (Ca), or an alloy containing at least one of these. For example, the circuit wiring (120) may comprise Cu.

[0059] The insulating layer (130) can cover circuit wiring (120) on the lower substrate (100) or the adhesive layer (110). According to exemplary embodiments, the insulating layer (130) may include an organic resin material. For example, the insulating layer (130) may include an acrylic resin, a urethane resin, an epoxy resin, etc.

[0060] In some embodiments, the insulating layer (130) may be formed using a solder resist composition or a dry film capable of photoetching. For example, the solder resist composition may include a binder resin, a photopolymerizable compound, a photopolymerization initiator, and a solvent. The binder resin may include the organic resin material described above. In one embodiment, the binder resin may include an acrylic resin.

[0061] The insulating layer (130) can be partially removed to expose pads (125a, 125b) corresponding to the ends of the connecting wire (125). The pads may include a first pad (125a) and a second pad (125b) connected to the first driving wire (122) and the second driving wire (124), respectively.

[0062] For example, the solder resist composition can be coated to cover circuit wiring (120) on a lower substrate (100) or a point adhesive layer (110) and then cured. The cured film can be partially removed through a photolithography process to expose pads (125a, 125b).

[0063] The light-emitting element (140) can be electrically connected to the pads (125a, 125b) using a conductive intermediary structure (128) through the terminals described above. The conductive intermediary structure (128) may include solder bumps containing tin (Sn), lead (Pb), etc.

[0064] For example, as described above, the insulating layer (130) can be partially removed to form a hole that exposes the pads (125a, 125b). Solder paste can be filled into the hole, and a light-emitting element (140) can be laminated on the solder paste. Subsequently, a conductive intermediate structure (128) can be formed through a heat pressing process, and the light-emitting element (140) can be electrically connected to the pads (125a, 125b).

[0065] The light-emitting element (140) may include a light-emitting diode (RGB) and an integrated circuit chip (IC). The light-emitting diode (RGB) may include a red (R) pixel or red light-emitting diode (LED), a green (G) pixel or green light-emitting diode (LED), and a blue (B) pixel or blue light-emitting diode (LED).

[0066] In some embodiments, as shown in FIG. 2, the light-emitting diode (RGB) and the integrated circuit chip (IC) may be integrated into a single package or module. For example, the light-emitting element (140) may be provided in the form of an LED package.

[0067] In contrast, light-emitting diodes (RGB) and integrated circuit chips (ICs) can be provided as separate units or individual chips.

[0068] A protective layer (150) may be formed on an insulating layer (130) to cover light-emitting elements (140). The protective layer (150) and the insulating layer (130) may be enclosed by the inner wall of the dam structure (160). The protective layer (150) and the insulating layer (130) may be in contact with the inner wall of the dam structure (160).

[0069] An upper substrate (170) may be disposed on the dam structure (160) and the protective layer (150). The upper substrate (170) may be provided as a window substrate or an outermost substrate of the transparent display device. The upper substrate (170) may include a transparent resin film or glass substrate that is substantially the same or similar as the lower substrate (100).

[0070] The protective layer (150) may be provided as an encapsulation layer of the transparent display device or light-emitting elements (140). According to exemplary embodiments, the protective layer (150) may comprise a silicon-based optically transparent resin. Accordingly, the protective layer (150) may have relatively high peeling or release properties with respect to the upper substrate (170). Thus, the repair process described below can be easily performed.

[0071] In some embodiments, the dam structure (160) may also include a silicone-based optically transparent resin. Accordingly, the reliability of the repair process can be further enhanced.

[0072] The above silicon-based optically transparent resin comprises a network of silicon (Si) atoms, and, for example, the resin structure may be formed by repeating siloxane bonds (-O-Si-O-). In one embodiment, the silicon-based optically transparent resin may not include acrylate units or acrylate-derived units.

[0073] Si-O bonds have higher bonding energy than CC bonds and can possess high thermal, optical, and / or chemical stability. Additionally, they exhibit high hydrophobicity and can provide moisture barrier properties. Furthermore, silicone-based optical transparent resins have low brittleness and can possess higher shock absorption properties compared to acrylic-based optical transparent resins.

[0074] Accordingly, an encapsulation structure for light-emitting elements (140) having enhanced external moisture and shock absorption characteristics by the protective layer (150) and the dam structure (160) can be implemented.

[0075] In some embodiments, the silicone-based optically transparent resin may include repeating units represented by Chemical Formula 1.

[0076] <Chemical Formula 1>

[0077]

[0078] In Formula 1, R1, R2, R3, and R4 may each independently be hydrogen, a C1-C10 alkyl group, a C2-C10 alkenyl group, a C3-C10 alkynyl group, or a C1-C10 alkoxy group. In one embodiment, at least one of R1, R2, R3, and R4 may include a C1-C10 alkyl group, a C2-C10 alkenyl group, a C3-C10 alkynyl group, or a C1-C10 alkoxy group. In one embodiment, at least one of R1, R2, R3, and R4 may be a C1-C10 alkyl group.

[0079] The terminal of the above silicone-based optical transparent resin may be hydrogen, a C1-C10 alkyl group, a C1-C10 alkoxy group, or a hydroxyl group. For example, the terminal of the above silicone-based optical transparent resin may be a hydroxyl group.

[0080] According to exemplary embodiments, the Shore A hardness of the protective layer (150) may be smaller than the Shore A hardness of the insulating layer (130). Accordingly, the circuit wiring (120) can be stably fixed and protected through the insulating layer (130) having sufficient rigidity. In addition, as described above, the protective layer (150) can provide external shock / moisture absorption / blocking characteristics while ensuring release properties for the repair process.

[0081] According to exemplary embodiments, the Shore A hardness of the protective layer (150) may be 40 to 65. In one embodiment, the Shore A hardness of the protective layer (150) may be 45 to 65, 45 to 60, 50 to 65, or 55 to 60.

[0082] Within the hardness range described above, repair characteristics and bag reliability through the protective layer (150) can be more effectively secured.

[0083] The Shore A hardness of the protective layer (150) can be controlled through the content of the optically transparent resin in the composition containing the optically transparent resin described above, the number of repeating units in the optically transparent resin, and / or the curing time or amount of light irradiation after application of the composition, the drying temperature, etc.

[0084] Shore A hardness can be measured according to test standards ISO 7619-1 and ASTM D 2240.

[0085] According to exemplary embodiments, the penetration hardness of the protective layer (150) may be 5 dmm to 15 dmm. In one embodiment, the penetration hardness of the protective layer (150) may be 6 dmm to 14 dmm, 8 dmm to 12 dmm, or 9 dmm to 11 dmm.

[0086] Penetration hardness can be measured by indentation at 25°C according to ASTM D1321 standard.

[0087] In exemplary embodiments, the penetration hardness measurement of the protective layer (150) may be smaller than the penetration hardness measurement of the dam structure (160). In this case, the repair process described later can be performed more easily while ensuring sufficient adhesion of the dam structure (160).

[0088] In some embodiments, the penetration hardness of the dam structure (160) may be 16 dmm to 25 dmm, 16 dmm to 20 dmm, or 16 dmm to 18 dmm.

[0089] The thickness of the protective layer (150) sufficiently protects the light-emitting elements (140) and can be adjusted in consideration of the hardness range described above and the repair process described below. According to exemplary embodiments, the thickness of the protective layer (150) may be formed to be 1.5 to 4 times, or 1.5 to 3 times, the thickness of the light-emitting element (140). For example, the thickness of the protective layer (150) may be 1.3 mm to 4 mm. In some embodiments, the thickness of the protective layer (150) may be 1.5 mm to 3.5 mm.

[0090] The thickness of the insulating layer (130) can be adjusted considering the coverage of the circuit wiring (120) and the flexibility of the transparent display device. In some embodiments, for example, the thickness of the insulating layer (130) may be 50 µm to 1 mm, 80 µm to 1 mm, or 100 µm to 1 mm.

[0091] FIG. 3 is a schematic cross-sectional view illustrating a transparent display device according to some exemplary embodiments. Detailed descriptions of configurations, structures, and / or materials that are substantially the same or similar as those described with reference to FIG. 1 and FIG. 2 are omitted.

[0092] Referring to FIG. 3, the protective layer (150) may have a multilayer structure. According to exemplary embodiments, the protective layer (150) may include a first protective layer (150a) and a second protective layer (150b) sequentially stacked from the insulating layer (130).

[0093] A first protective layer (150a) may be formed on the upper surface of an insulating layer (130) to cover light-emitting elements (140). The first protective layer (150a) may be provided as an internal encapsulation layer. A second protective layer (150b) may be formed on the upper surface of the first protective layer (150a). An upper substrate (170) may be laminated on the second protective layer (150b).

[0094] In some embodiments, the first protective layer (150a) is in contact with the upper surface of the insulating layer (130), and the second protective layer (150b) may be in contact with the upper surface of the first protective layer (150a).

[0095] As described above, the first protective layer (150a) and the second protective layer (150b) may each comprise a silicone-based optically transparent resin. In some embodiments, the Shore A hardness or penetration hardness of the first protective layer (150a) and the second protective layer (150b) may be adjusted within the range of the protective layer (150) described above.

[0096] In some embodiments, the first protective layer (150a) and the second protective layer (150b) may each have a Shore A hardness in the range described above. In this case, the first protective layer (150a) and the second protective layer (150b) may each have a Shore A hardness of 40 to 65. In one embodiment, the Shore A hardness of the first protective layer (150a) and the second protective layer (150b) may be 45 to 65, 45 to 60, 50 to 65, or 55 to 60.

[0097] In some embodiments, the first protective layer (150a) and the second protective layer (150b) may each have a penetration hardness in the range described above. In this case, it may be 5 dmm to 15 dmm, 6 dmm to 14 dmm, 8 dmm to 12 dmm, or 9 dmm to 11 dmm.

[0098] In some embodiments, the first protective layer (150a) has a Shore A hardness in the range described above, and the second protective layer (150b) may have a penetration hardness in the range described above. In this case, the Shore A hardness of the first protective layer (150a) may be 40 to 65, 45 to 65, 45 to 60, 50 to 65, or 55 to 60. The penetration hardness of the second protective layer (150b) may be 5 dmm to 15 dmm, 6 dmm to 14 dmm, 8 dmm to 12 dmm, or 9 dmm to 11 dmm.

[0099] In some embodiments, the first protective layer (150a) has a penetration hardness in the range described above, and the second protective layer (150b) may have a Shore A hardness in the range described above. The penetration hardness of the first protective layer (150a) may be 5 dmm to 15 dmm, 6 dmm to 14 dmm, 8 dmm to 12 dmm, or 9 dmm to 11 dmm. The Shore A hardness of the second protective layer (150b) may be 40 to 65, 45 to 65, 45 to 60, 50 to 65, or 55 to 60.

[0100] According to the design of the first protective layer (150a) and the second protective layer (150b) described above, sufficient adhesion to the light-emitting element (140) can be secured while maintaining release / repair characteristics.

[0101] According to exemplary embodiments, the measured value of the penetration hardness of the first protective layer (150a) or the second protective layer (150b) may be smaller than the measured value of the penetration hardness of the dam structure (160). Accordingly, sufficient adhesion between the insulating layer (130) and the protective layer (150) and the dam structure (160) can be maintained during the repair process.

[0102] In some embodiments, the thickness of the second protective layer (150b) may be smaller than the thickness of the first protective layer (150a). Accordingly, the removal or partial removal of the second protective layer (150b) can be easily performed in the repair process described later.

[0103] For example, the thickness of the second protective layer (150b) may be 0.1 mm to 1.5 mm, 0.2 mm to 1 mm, or 0.3 mm to 1 mm. The thickness of the first protective layer (150a) may be 1 mm to 3 mm, or 1 mm to 2.5 mm. In one embodiment, the sum of the thicknesses of the first and second protective layers (150a, 150b) may be adjusted to the thickness range of the protective layer (150) described with reference to FIG. 1.

[0104] FIG. 4 is a schematic plan view showing a transparent display device according to exemplary embodiments.

[0105] Referring to FIG. 4, the structure described with reference to FIG. 1 can be provided as a single light-emitting element unit sheet (LDS). A plurality of light-emitting element unit sheets (LDS) can be repeatedly arranged along the first direction and the second direction to define a transparent display device (200).

[0106] The dam structure (160) can extend along the outer perimeter of the transparent display device (200). Additionally, the dam structure (160) can extend along the boundary of adjacent light-emitting element unit sheets (LDS) and cover the ends of adjacent light-emitting element unit sheets (LDS) together.

[0107] According to exemplary embodiments, the dam structure (160) may include a first portion (160a) extending along the outer perimeter of a transparent display device (200) and a second portion (160b) extending along the boundary of adjacent light-emitting element unit sheets (LDS). The first portion (160a) and the second portion (160b) may be formed substantially as a single member.

[0108] In one embodiment, the dam structure (160) may not cover the light-emitting element (140) at the boundary. For example, the second part (160b) may not cover the light-emitting element (140).

[0109] In one embodiment, the spacing between the opposing rows of light-emitting elements (LC) included in each of the adjacent light-emitting element unit sheets (LDS) may be 5 mm to 15 mm, or 6 mm to 10 mm. The width of the dam structure (160) may be 1 mm to 5 mm, 1 mm to 3 mm, or 1 mm to 2 mm. Thus, the upper substrate (170) can be stably supported without covering the light-emitting element (140).

[0110] In one embodiment, the upper substrate (170) may be provided as a common substrate for a plurality of light-emitting element unit sheets (LDS).

[0111] FIG. 5 is a schematic partial enlarged plan view showing a transparent display device according to some exemplary embodiments.

[0112] Referring to FIG. 5, the first light-emitting element unit sheet (LDS1) and the second light-emitting element unit sheet (LDS2) may be arranged adjacent to each other. The first light-emitting element row (LC1) arranged at the outer end of the first light-emitting element unit sheet (LDS1) and the second light-emitting element row (LC2) arranged at the outer end of the second light-emitting element unit sheet (LDS2) may be adjacent to each other, for example, facing each other in the first direction.

[0113] When the gap between the first light-emitting element row (LC1) and the second light-emitting element row (LC2) is small (e.g., 5 mm or less, 4 mm or less, or 3 mm or less), the second part (160b) of the dam structure (160) can cover the light-emitting elements (140) included in the first light-emitting element row (LC1) and the second light-emitting element row (LC2) in a planar direction.

[0114] In one embodiment, as shown in FIG. 5, a second part (160b) of the dam structure (160) can cover the light-emitting elements (140) included in the first light-emitting element row (LC1) and the second light-emitting element row (LC2) entirely.

[0115] In one embodiment, the light-emitting elements (140) included in either the first light-emitting element row (LC1) and the second light-emitting element row (LC2) may be covered entirely, and the light-emitting elements (140) included in the other may be partially covered.

[0116] In this case, the transmittance of the dam structure (160) may be 99% or higher. Accordingly, the light-emitting elements (140) at the outer end may be protected without impairing the visibility characteristics of the light or image generated from the light-emitting elements (140).

[0117] As described above, the dam structure (160) can be formed by applying a dam composition containing a silicone-based optically transparent resin along the outer perimeter of light-emitting element unit sheets and then curing or drying it. The dam composition includes a solvent and may further include additives such as a curing agent, a crosslinking agent, etc.

[0118] In some embodiments, the viscosity of the dam composition is 25 o C can be 30,000 cps to 100,000 cps. Within the above range, the light-emitting element unit sheets can be stably fixed, and the transparent display device (200) can be stably protected from external shocks.

[0119] In one embodiment, the viscosity of the dam composition is 25 o C can be 50,000 cps to 100,000 cps, 50,000 cps to 90,000 cps, or 60,000 cps to 80,000 cps.

[0120] FIGS. 6 through 11 are schematic plan and cross-sectional views illustrating a repair method for a transparent display device according to exemplary embodiments. For convenience of illustration, in FIG. 6, a defective light-emitting element (145) is depicted as being positioned in the upper left corner.

[0121] Referring to FIG. 6, a transparent display device can be manufactured as described above. For example, circuit wiring (120) can be formed on a lower substrate (100), and a dam structure (160) can be formed by applying and curing the dam composition described above along the perimeter of the lower substrate (100). An insulating layer (130) covering the circuit wiring (120) in the space partitioned by the dam structure (160) can be formed using a composition containing the organic resin material described above, a dry film, etc. A light-emitting element (140) connected to the circuit wiring (120) can be placed on the insulating layer (130).

[0122] A composition containing the aforementioned silicone-based optically transparent resin can be filled into the space partitioned by the dam structure (160) and then cured to form a protective layer (150). Subsequently, an upper substrate (170) can be attached to the dam structure (160) and the protective layer (150).

[0123] A defective light-emitting element (145) can be detected through the operation or testing of the light-emitting elements (140) of the transparent display device manufactured as described above.

[0124] Afterwards, the defective light-emitting element (145) can be replaced through a repair process described with reference to FIGS. 7 to 11.

[0125] Referring to FIG. 7, the upper substrate (170) can be peeled off from the dam structure (160) and the protective layer (150). According to exemplary embodiments, a cutting tool, such as a knife or a steel wire, can be inserted into the interface between the upper substrate (170) and the dam structure (160), and then the cutting tool can be moved horizontally to detach the upper substrate (170) from the transparent display device.

[0126] As described above, the dam structure (160) and the protective layer (150) may include a silicone-based optically transparent resin having relatively low hardness and improved release properties. Thus, the upper substrate (170) can be easily separated without damaging the cutting tool, the upper substrate (170), and the dam structure (160).

[0127] Referring to FIG. 8, the defective light-emitting element (145) can be removed by at least partially removing the portion of the protective layer (150) around the defective light-emitting element (145). Afterward, a normal light-emitting element (140) can be attached to the space where the defective light-emitting element (145) was removed. Accordingly, the repair process of the defective light-emitting element (145) can be substantially implemented.

[0128] As described above, the protective layer (150) may include a silicone-based optically transparent resin having relatively reduced adhesive strength. Therefore, only the portion of the protective layer (150) around the defective light-emitting element (145) can be selectively and easily removed without causing damage to the structure around the normal light-emitting element (140).

[0129] Referring to FIG. 9, surface treatment can be performed on the upper surface of the protective layer (150).

[0130] In some embodiments, impurities, process residues, etc. from the repair process described above may remain on the upper surface of the protective layer (150), and said impurities or residues can be removed through a cleaning process using a cleaning solution.

[0131] In some embodiments, unevenness such as irregularities may be caused on the surface of the protective layer (150) by the repair process, and deburring may be performed by contacting / moving horizontally on the upper surface of the protective layer (150) with a surface treatment tool such as a knife or steel wire.

[0132] Through the above surface treatment, the surface roughness and surface characteristics of the protective layer (150) can be restored.

[0133] Referring to FIG. 10, the above-described silicon-based optical transparent resin can be supplemented. Accordingly, the resin material is filled into the space where the protective layer (150) around the repaired light-emitting element (140) has been removed, so that the protective layer (150) can be restored to sufficiently cover all light-emitting elements (140) again.

[0134] Referring to FIG. 11, the upper substrate (170) can be reattached to the dam structure (160) and the regenerated protective layer (150). Accordingly, a repaired transparent display device can be obtained.

[0135] Hereinafter, examples are presented to aid in understanding the present invention; however, these examples are merely illustrative of the invention and do not limit the appended claims. It is obvious to those skilled in the art that various changes and modifications to the examples are possible within the scope and spirit of the invention, and that such variations and modifications fall within the scope of the appended claims.

[0136] Experimental Example 1: Evaluation of Upper Substrate Separation

[0137] A glass substrate of 1.8 mm was prepared. An adhesive layer composition (DOWSIL® 96-083 Silicone Adhesive Kit, DOW; containing 70% solid content) was applied to one side of a copper layer with a thickness of 50 μm by a Gravure Coating method, and then cured at 150°C for 2 minutes to produce a metal thin film with a silicone-based adhesive layer having a thickness of 10 μm.

[0138] A metal thin film was bonded to one side of the glass substrate through the adhesive layer, and a copper layer was patterned to form circuit wiring. A light-emitting diode (LED) chip with a thickness of 0.7 mm was mounted on the circuit wiring through a soldering process.

[0139] Subsequently, a protective layer covering the LED chip was formed according to the optically transparent resin and thickness conditions of the examples and comparative examples in Table 1 below, and a cover glass (upper substrate) was attached on the protective layer.

[0140] Specifically, a composition containing the optically transparent resin was applied using a jetting dispenser from Mycronic. A metal halide lamp was used at a wavelength of 365 nm and an energy of 4000 mJ / cm². 2 The above composition was cured through light irradiation under certain conditions to form a protective layer.

[0141] An upper substrate was detached from a transparent display device of the embodiments and comparative examples including a protective layer formed under the conditions listed in Table 1. Specifically, a steel wire was inserted between the upper substrate and the protective layer, and then the upper substrate was separated by moving the steel wire at a predetermined speed.

[0142] During the above separation process, whether the upper substrate was separated without bending or breaking of the steel wire was observed and evaluated as follows.

[0143] OK: Only the upper substrate is cleanly separated without steel wire deformation

[0144] NG: Deformation such as steel wire bending or breaking occurs before the upper substrate is separated

[0145] The evaluation results are listed together in Table 1 below.

[0146] Protective Layer Resin Protective Layer Thickness Substrate Separation Evaluation Example 1 Silicon-based OCR_A 1.5 mm OK Example 2 Silicon-based OCR_A 3.0 mm OK Example 3 Silicon-based OCR_B 1.5 mm OK Example 4 Silicon-based OCR_B 3.0 mm OK Example 5 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 1.0 mm Top layer: 0.3 mm Total thickness: 1.3 mm OK Example 6 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 1.2 mm Top layer: 0.3 mm Total thickness: 1.5 mm OK Example 7 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 1.5 mm Top layer: 0.3 mm Total thickness: 1.8 mm OK Example 8 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 2.0mm Top layer: 0.3mm Total thickness: 2.3mm OK Example 9 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 2.0mm Top layer: 0.5mm Total thickness: 2.5mm OK Example 10 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 2.5mm Top layer: 0.3mm Total thickness: 2.8mm OK Example 11 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 2.5mm Top layer: 0.5mm Total thickness: 3.0mm OK Example 12 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 2.0mm Top layer: 0.8mm Total thickness: 2.8mm OK Example 13 Bottom layer: Silicon-based OCR_B Top layer: Silicon-based OCR_A Bottom layer: 2.0mm Top layer: 1.0mm Total thickness: 3.0mm OK Example 14 Bottom layer: Silicone-based OCR_A Top layer: Silicone-based OCR_A Bottom layer: 1.0mm Top layer: 0.5mm Total thickness: 1.5mm OK Example 15 Bottom layer: Silicone-based OCR_A Top layer: Silicone-based OCR_A Bottom layer: 2.0mm Top layer: 1.0mm Total thickness: 3.0mm OK Example 16 Bottom layer: Silicone-based OCR_B Top layer: Silicone-based OCR_B Bottom layer: 1.0mm Top layer: 1.0mm Total thickness: 2.0mm OK Example 17 Bottom layer: Silicone-based OCR_B Top layer: Silicone-based OCR_B Bottom layer: 2.0mm Top layer: 1.0mm Total thickness: 3.0mm OK Comparative Example 1 Acrylic-based OCR_A 1.5mm NG Comparative Example 2Acrylic OCR_A3.0 mmNG Comparative Example 3 Acrylic-based OCR_B 1.5 mmNG Comparative Example 4 Acrylic-based OCR_B 3.0 mmNG.

[0147] The resins used to form the protective layer listed in Table 1 are specifically as follows.

[0148] 1) Silicone-based OCR_A: A silicone-based optically transparent resin represented by Chemical Formula 1-1 below, having a Shore A hardness in the range of 55 to 60 after curing.

[0149] [Chemical Formula 1-1]

[0150]

[0151] 2) Silicon-based OCR_B: Represented by the above chemical formula 1-1, and 25 o Silicone-based optically transparent resin with a penetration hardness in the range of 9 to 10 after curing at C

[0152] 3) Acrylic OCR_A: LOCTITE / Product Name: AA 3311

[0153] 4) Acrylic OCR_B: BestRoom / Product Name: BR OCR 400

[0154] The Shore A hardness of silicon-based OCR_A was measured according to ISO 7619-1 and ASTM D 2240 standards using a digital durometer hardness tester and a Zwick 3130 indenter.

[0155] The penetration hardness of silicon-based OCR_B was measured by indentation at 25°C using the indenter according to the D1321 standard.

[0156] Referring to Table 1, in the examples where a protective layer covering the LED chip was formed using a silicon-based optically transparent resin, the upper substrate was substantially detached for the repair process. In the comparative examples where a protective layer was formed using an acrylic-based optically transparent resin, the upper substrate was not substantially detached due to the high adhesion and hardness of the protective layer.

Claims

1. Lower substrate; A dam structure formed along the outer edge of the lower substrate and comprising a silicon-based optically transparent resin; Circuit wiring arranged on the lower substrate above; An insulating layer formed on the lower substrate and covering the circuit wiring; Light-emitting elements mounted on the insulating layer and connected to the circuit wiring; A protective layer formed on the insulating layer above, covering the light-emitting elements and comprising a silicon-based optically transparent resin; and A transparent display device comprising the above dam structure and an upper substrate attached to the above protective layer.

2. A transparent display device according to claim 1, wherein the Shore A hardness of the protective layer is 40 to 65.

3. A transparent display device according to claim 2, wherein the Shore A hardness of the protective layer is 50 to 65.

4. A transparent display device according to claim 1, wherein the penetration hardness of the protective layer, measured by indentation at 25°C according to the ASTM D1321 standard, is 5 dmm to 15 dmm.

5. A transparent display device according to claim 4, wherein the penetration hardness of the protective layer is 8 dmm to 12 dmm.

6. A transparent display device according to claim 4, wherein the measured value of the penetration hardness of the dam structure is greater than the measured value of the penetration hardness of the protective layer.

7. A transparent display device according to claim 6, wherein the penetration hardness of the dam structure is 16 dmm to 25 dmm.

8. A transparent display device according to claim 1, wherein the protective layer comprises a first protective layer formed on the insulating layer to cover the light-emitting element and a second protective layer formed on the first protective layer.

9. A transparent display device according to claim 8, wherein each of the first protective layer and the second protective layer has a Shore A hardness in the range of 40 to 65.

10. A transparent display device according to claim 8, wherein each of the first protective layer and the second protective layer is measured by indentation at 25°C according to ASTM D1321 standard and has a penetration hardness in the range of 5 dmm to 15 dmm.

11. A transparent display device according to claim 8, wherein the Shore A hardness of the first protective layer is 40 to 65, and the penetration hardness of the second protective layer, measured by indentation at 25°C according to ASTM D1321 standard, is 5 dmm to 15 dmm.

12. A transparent display device according to claim 8, wherein the penetration hardness of the first protective layer measured by indentation at 25°C according to ASTM D1321 standard is 5 dmm to 15 dmm, and the Shore A hardness of the second protective layer is 40 to 65.

13. A transparent display device according to claim 8, wherein the thickness of the first protective layer is greater than the thickness of the second protective layer.

14. In claim 1, the transparent display device comprises a plurality of light-emitting element unit sheets, each comprising the lower substrate, the circuit wiring, the insulating layer, the light-emitting element, and the protective layer, respectively. A transparent display device in which the above dam structure covers the boundary of adjacent light-emitting element unit sheets.

15. In claim 14, a plurality of light-emitting elements are arranged in a column direction to define a column of light-emitting elements, and each of the light-emitting element unit sheets includes the columns of light-emitting elements that are repeatedly arranged in a row direction. A transparent display device in which the above dam structure at least partially covers the light-emitting elements included in rows of light-emitting elements belonging to different light-emitting element unit sheets adjacent in the above row direction.

16. A step of detecting a defective light-emitting element among the light-emitting elements of the transparent display device according to claim 1; A step of peeling the upper substrate from the dam structure and the protective layer; A step of removing the defective light-emitting element from the protective layer; A step of mounting a normal light-emitting element in the space from which the defective light-emitting element was removed; and A repair method for a transparent display device comprising the step of reattaching the upper substrate.

17. A repair method for a transparent display device according to claim 16, further comprising the step of surface treating the protective layer after mounting the normal light-emitting element.

18. A method for repairing a transparent display device according to claim 16, further comprising the step of supplementing a silicon-based optically transparent resin on the protective layer after the step of mounting the normal light-emitting element.

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