Micro LED module having high optical density and high sensitivity characteristics, manufacturing method therefor, and micro display panel

Abstract

Disclosed are a micro LED module having high optical density and high sensitivity characteristics, a manufacturing method therefor, and a micro display panel. According to an aspect of the present embodiment, a micro LED module comprises: a substrate on which R, G, and B micro LEDs are disposed; an electrical circuit layer disposed on one surface of the substrate and electrically connected to the micro LEDs; a pixel defined layer disposed on the electrical circuit layer, defining a light-emitting area of each micro LED, and including a pattern formed at a predetermined interval for separating each micro LED from each other; and a protective layer formed in a form of covering the micro LEDs and the pixel defined layer, wherein the pixel defined layer includes a black light shielding agent of at least one of carbon black, CNT (carbon nanotube), black pigment, and black dye.

Description

Micro LED module having high optical density and high sensitivity characteristics and method of manufacturing the same, micro display panel

[0001] The present invention relates to a micro LED module having high optical density and high sensitivity characteristics and a method for manufacturing the same.

[0002] The content described in this section merely provides background information regarding the present embodiment and does not constitute prior art.

[0003] In the recent information society, the importance of displays as a medium for conveying visual information is being emphasized even more. In particular, LEDs, which are semiconductor light-emitting devices, have the advantage of emitting high-intensity light at low power consumption because they emit light themselves, unlike liquid crystal displays (LCDs) and CRTs. Due to this advantage, they are gaining popularity as displays for various electronic devices.

[0004] Micro LEDs are ultra-small light-emitting devices that emit light on their own without color filters. Because panels are made by joining light-emitting LED pieces together, they have the advantage of having no limitations on size, shape, or resolution. They possess superior characteristics compared to OLED devices in terms of high efficiencies, low power consumption, and long lifespan, making them a strong candidate for application as a light source for next-generation displays. They are also expected to enable the creation of lightweight and clear AR / VR devices, as well as wearables.

[0005] Micro LED is a display that uses inorganic materials to fabricate micro LED chips ranging in size from 5 to 100 µm and uses them as a light source. While its structure is similar to conventional LEDs, the ultra-small LEDs themselves can be utilized as pixels without a separate packaging process. As such, displays using micro LEDs overcome the structural limitations of LCDs and the vulnerability of OLEDs to oxygen, moisture, and heat, enabling high reliability, high brightness, and long lifespan, as well as the realization of displays in various form factors.

[0006] A display device including such a micro LED module is implemented by arranging numerous LED modules (10), each having a very small size in the micro range, in a tiled form.

[0007] FIG. 1 is a diagram illustrating the configuration of an LED module according to an embodiment of the prior art.

[0008] Referring to FIG. 1, a conventional LED module (10) may include a substrate (11), a thin film transistor (TFT) layer (12) formed on one side of the substrate (11), R, G, and B micro LEDs (13) formed on the TFT layer (12), a pixel define layer (PDL) (14) that separates into pixel units formed between each micro LED (13), a protective layer (15) formed to cover the micro LEDs (13) and the pixel define layer (14), and a polarizing layer (16) disposed on the protective layer (15). A red (R) micro LED, a green (G) micro LED, and a blue (B) micro LED may form a single pixel.

[0009] Here, the substrate (11) can be formed of a flexible material, and the pixel definition layer (14)) can be implemented of a transparent material. The polarization layer (16) may use a polarizing plate or polarizing film that is polarized in one direction to prevent external light reflection.

[0010] The TFT layer (12) is provided with a TFT electrode pad, and the micro LED (13) may be provided with an LED electrode pad that is electrically connected to each of the multiple TFT electrode pads. Accordingly, the TFT layer (12) performs the role of switching on / off a pixel composed of R, G, and B micro LEDs (13).

[0011] As shown in FIG. 2, conventional LED modules have no partitions, so color mixing occurs between RGB subpixels, resulting in reduced color purity of the display and limiting the implementation of a high color purity display. Additionally, the transparent pixel definition layer (14) uses an insulating material such as photosensitive polyimide (PSPI) and simply serves to separate the space between subpixels. As shown in FIG. 3, the LED module (10) has a problem in that external light is reflected from circuit elements such as metal electrodes, such as TFT electrode pads or LED electrode pads, provided inside the transparent pixel definition layer (14), and from the TFT layer (12), etc., which reduces display visibility.

[0012] In addition, conventionally, a polarizing layer (16) with a thickness of approximately 50 μm is used to prevent external light reflection, but due to the polarizing layer (16), the light extraction efficiency (approximately 50% brightness) is reduced, and the light emitted from the display is suppressed, resulting in a decrease in brightness.

[0013] A display device using such an LED module (10) may require brighter brightness to improve visibility, and when high brightness is achieved, heat is generated as the light output increases, which may lead to reduced reliability in the long term and increased energy consumption.

[0014] One objective of the present invention is to provide a micro LED module having high optical density and high sensitivity characteristics and a method for manufacturing the same, wherein a black pixel definition layer with a pattern formed to act as a barrier between subpixels of a micro LED module is applied to prevent light generated from subpixels from interfering with each other and to prevent light entering from the outside from hitting and reflecting off electrodes and driving circuits within the module.

[0015] According to one aspect of the present invention, a micro LED module comprises: a substrate on which R, G, and B micro LEDs are arranged; an electrical circuit layer disposed on one surface of the substrate and electrically connected to the micro LEDs; a pixel defined layer disposed on the electrical circuit layer and including a pattern formed at predetermined intervals to define a light-emitting region of each micro LED and to separate each micro LED from one another; and a protective layer formed to cover the micro LEDs and the pixel defined layer, wherein the pixel defined layer comprises at least one black light-shielding agent selected from carbon black, CNT (carbon nanotube), black pigment, and black dye.

[0016] According to one aspect of the present invention, the pixel definition layer is characterized by the photoinitiator and binder being mixed in the light-blocking agent at a predetermined ratio.

[0017] According to one aspect of the present invention, the pixel definition layer is characterized in that, when each micro LED is formed with a first height (h, h>0) or greater, a pattern is formed between each micro LED with a first line width (L) or less, and the first line width (L) is set to be greater than or equal to the first height and less than or equal to twice the first height.

[0018] According to one aspect of the present invention, the previously set interval is characterized as being a uniform interval.

[0019] According to one aspect of the present invention, a micro display panel is provided characterized by a plurality of micro LED modules of any one of claims 1 to 4 being combined in a tiling configuration.

[0020] According to one aspect of the present invention, the method comprises: a first step of forming a substrate on the R, G, and B micro LEDs such that the R, G, and B micro LEDs are arranged on an upper surface and are electrically insulated from each other; a second step of forming an electrical circuit layer formed on the substrate and electrically connected to each of the R, G, and B micro LEDs; a third step of forming a pixel defined layer disposed on the electrical circuit layer and including a pattern formed at a predetermined interval to define a light-emitting region of each micro LED and to separate each micro LED from each other; and a fourth step of forming a protective layer in a manner that covers the micro LEDs and the pixel defined layer, wherein the pixel defined layer comprises at least one black light-blocking agent selected from carbon black, CNT (carbon nanotube), black pigment, and black dye.

[0021] According to one aspect of the present invention, the pixel defining layer is characterized by being formed of a black photocurable resin by mixing a binder, a monomer having an organic-inorganic hybrid structure, a photoinitiator, a dispersant, and a solvent in a predetermined ratio with the light-blocking agent.

[0022] According to one aspect of the present invention, the photocurable resin is characterized by having photocurable substituents and thermocurable substituents introduced therein to possess photocurable properties.

[0023] According to one aspect of the present invention, the photocurable resin is 70 mJ / cm² 2 It is characterized by being formed to be photosensitive at the following energy.

[0024] According to one aspect of the present invention, the third step comprises: a process of forming a photoresist by coating a black photocurable resin on a substrate; a process of exposing and developing the photoresist; and a process of curing the developed photoresist to form a pixel definition layer.

[0025] According to one aspect of the present invention, the process of exposing and developing the photoresist is characterized by forming a pattern using a mask having a predetermined spacing.

[0026] According to one aspect of the present invention, the first line width (L) of the pattern is characterized by being set to be greater than or equal to the first height and less than or equal to twice the first height when each micro LED is formed at a first height (h, h>0).

[0027] According to one aspect of the present invention, the photoinitiator has ultraviolet absorption characteristics in a wavelength range of 365 nm or more.

[0028] According to one aspect of the present invention, a micro display panel is provided, characterized in that a plurality of micro LED modules manufactured according to the manufacturing method of any one of claims 7 to 13 are combined in a tiling form.

[0029] As described above, according to one aspect of the present invention, a black pixel definition layer is applied to a micro LED module using a black mill base having high optical density and high resistance characteristics, a high-sensitivity photoinitiator, a photocurable monomer, and a high-transmittance and high-heat-resistant organic-inorganic hybrid binder, and by forming a pattern on the black pixel definition layer that acts as a barrier to separate each micro LED from one another, the effect of suppressing RGB mixing between subpixels is achieved.

[0030] In addition, according to one aspect of the present invention, a black pixel definition layer can absorb external light to suppress external light reflection, and since there is no need to use a polarizing layer such as a separate polarizer or polarizing film, it is possible to achieve high brightness without increasing energy consumption.

[0031] FIG. 1 is a diagram illustrating the configuration of an LED module according to an embodiment of the prior art.

[0032] FIG. 2 is an example diagram for verifying the visibility of a display device to which an LED module according to an embodiment of the prior art is applied.

[0033] FIG. 3 is an example diagram illustrating the external light reflection phenomenon of a display device to which an LED module according to an embodiment of the prior art is applied.

[0034] FIG. 4 is a diagram illustrating the configuration of a micro display panel according to one embodiment of the present invention.

[0035] FIG. 5 is a diagram illustrating the configuration of a micro LED module according to one embodiment of the present invention.

[0036] FIG. 6 is a flowchart illustrating a method for manufacturing a micro LED module according to one embodiment of the present invention.

[0037] FIG. 7 is a diagram illustrating the mixing process of a pixel definition layer according to one embodiment of the present invention.

[0038] FIG. 8 is an illustrative diagram explaining the molecular structure of a photocurable resin according to one embodiment of the present invention.

[0039] FIG. 9 is an illustrative diagram for explaining the light absorption rate of a photoinitiator according to one embodiment of the present invention.

[0040] FIG. 10 is a diagram illustrating the process of forming a pixel definition layer according to one embodiment of the present invention.

[0041] FIG. 11 is a flowchart illustrating a surface modification process of carbon black according to one embodiment of the present invention.

[0042] FIG. 12 is an illustrative diagram explaining a surface modification process of carbon black according to one embodiment of the present invention.

[0043] FIG. 13 is a diagram illustrating the reflection phenomenon caused by external light in a micro display panel to which a micro LED module according to one embodiment of the present invention is applied.

[0044] FIG. 14 is a diagram showing the results of measuring the light intensity according to distance for a panel with a black pixel definition layer applied and a panel before application, respectively, according to an embodiment of the present invention.

[0045] The present invention is susceptible to various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Similar reference numerals have been used for similar components in the description of each drawing.

[0046] Terms such as first, second, A, B, etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and / or" includes a combination of a plurality of related described items or any of a plurality of related described items.

[0047] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0048] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" should be understood as not precluding the existence or addition of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification.

[0049] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains.

[0050] Terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0051] In addition, each component, process, procedure, or method included in each embodiment of the present invention may be shared within a scope that is not technically contradictory to one another.

[0052] FIG. 4 is a diagram illustrating the configuration of a micro display panel according to one embodiment of the present invention.

[0053] Referring to FIG. 4, a micro display panel (100) according to one embodiment of the present invention includes a substrate (110) and a plurality of micro LED modules (120) mounted on the substrate (110).

[0054] A substrate (110) has a thin-film transistor disposed on its upper surface and a circuit module provided on its lower surface, and three LEDs are mounted on each pixel of the substrate (110) to emit monochromatic light of R, G, and B, respectively. Accordingly, when a signal is applied from the outside, R, G, and B colored light is emitted from the LEDs for R, G, and B, so that an image can be displayed.

[0055] In this way, the display device (100) can be manufactured by connecting a plurality of single LEDs in a tile shape, but considering manufacturing convenience, the display device can be manufactured by manufacturing a plurality of LEDs into a single micro LED module (120) and then connecting each micro LED module.

[0056] FIG. 5 is a diagram illustrating the configuration of a micro LED module according to one embodiment of the present invention.

[0057] Referring to FIG. 5, a micro LED module (120) according to one embodiment of the present invention includes a substrate (210) on which R, G, and B micro LEDs (201a, 201b, 201c) are arranged, an electrical circuit layer (220), a pixel definition layer (230), and a protection layer (240).

[0058] The substrate (210) provides a space for the micro LED (201), electrical circuit layer (220), pixel definition layer (230), and protection layer (240) to be placed. The micro LED (201) is placed on the upper surface of the substrate (210) and emits light.

[0059] An electrical circuit layer (220) is disposed on one side of the substrate (210) and is electrically connected to the micro LED (201). This electrical circuit layer (220) supplies power to each micro LED (201) or electrically connects adjacent micro LED modules (120).

[0060] This electrical circuit layer (220) can be provided as a TFT (Thin Film Transistor) Backplane, and the substrate (210) can be provided as a flexible substrate of the TFT (Thin Film Transistor) Backplane.

[0061] The pixel definition layer (230) is disposed on the electrical circuit layer (220) and includes a pattern formed at predetermined intervals to define the light-emitting region of each micro LED (201) and to separate each micro LED (201) from one another. The pixel definition layer (230) includes at least one black light-shielding agent selected from carbon black, CNT (carbon nanotube), black pigment, and black dye.

[0062] The pixel definition layer (230) acts as a barrier to separate the light generated from R, G, and B micro LEDs (201a, 201b, 201c) so that they do not interfere with each other, and at the same time, it can perform the function of preventing light coming from the outside from touching the electrodes and driving circuits inside the module and being reflected. In this way, when a micro LED module (120) is manufactured using a black pixel definition layer (230) with a barrier-shaped pattern formed therein, it has the advantage of preventing interference between RGB colors, blocking and reflecting the emitted light to increase the brightness extracted into the light screen, and maximizing the light emission efficiency of the light emission area.

[0063] The black pixel definition layer (230) formed with a partition-shaped pattern can perform an external light reflection prevention function, so there is no need to use a polarization layer applied to the existing LED module to prevent external light reflection, and as a result, the overall thickness of the micro LED module (120) can be reduced by the thickness of the polarization layer.

[0064] The protective layer (240) is formed in a shape that covers the micro LED (201) and the pixel definition layer (230), and is electrically insulated from the micro LED (201) and the pixel definition layer (230), and can be made of a mixed material having suitable mechanical strength.

[0065] FIG. 6 is a flowchart illustrating a method for manufacturing a micro LED module according to one embodiment of the present invention.

[0066] Referring to FIG. 6, a method for manufacturing a micro LED module involves placing R, G, and B micro LEDs (201) on the upper surface of a substrate (210) so that the R, G, and B micro LEDs (201) are electrically insulated from each other (S10).

[0067] The above method forms an electrical circuit layer (220) electrically connected to each of the R, G, and B micro LEDs (201) on a substrate (210) (S20).

[0068] Additionally, the above method defines the light-emitting region of each micro LED (201) on the electrical circuit layer (220) and forms a pixel definition layer (230) including a pattern formed at a predetermined interval to separate each micro LED (201) from one another (S30). The pixel definition layer (230) is manufactured using a black light-shielding agent, wherein a photoinitiator and a binder are mixed in the light-shielding agent at a predetermined ratio.

[0069] The above method forms a protective layer (240) in the form of covering the micro LED (201) and the pixel definition layer (230) (S40).

[0070] FIG. 7 is a diagram illustrating the formulation process of a pixel definition layer according to one embodiment of the present invention, FIG. 8 is an illustrative diagram illustrating the molecular structure of a photocurable resin according to one embodiment of the present invention, FIG. 9 is an illustrative diagram illustrating the light absorption rate of a photoinitiator according to one embodiment of the present invention, and FIG. 10 is a diagram illustrating the formation process of a pixel definition layer according to one embodiment of the present invention.

[0071] As illustrated in FIG. 7, the manufacturing method can produce a black photocurable resin by mixing a binder, a monomer having an organic-inorganic hybrid structure, a photoinitiator, a black pigment, a dispersant, and a solvent in a predetermined ratio to produce a pixel defining layer (230) having high optical density and high sensitivity characteristics.

[0072] The black photocurable resin manufactured in this way has high heat resistance and high sensitivity characteristics through photocuring, with a photocurable substituent (R1) and a thermocurable substituent (R2) introduced as shown in FIG. 8. In addition, as shown in FIG. 9, the photoinitiator has ultraviolet absorbance in a long wavelength range of 365 nm or longer.

[0073] As illustrated in FIG. 10, the manufacturing method can form a black pixel defining layer (230) by coating a black photocurable resin on a substrate ((a)) to form a photoresist ((b)), exposing (c) and developing (d) the photoresist, and then curing (e) the developed photoresist. At this time, the black pixel defining layer (230) can have a pattern with uniform spacing formed by using a mask (1000) that determines the shape of the pattern in the exposure process, and the pattern formed in this way serves as a barrier.

[0074] When each micro LED (201) is formed with a first height (h, h > 0) or greater, a pattern of a first line width (L) or less is formed between each micro LED (201), and h ≤ L ≤ 2h can be set. Here, h can be 5 μm. Since the micro LED display panel has a very narrow pixel pitch spacing, the pattern of the black pixel definition layer (230) can be formed with a line width of 10 μm or less.

[0075] The deposition thickness of the OLED light source is 100 to 200 nm, and the height of the barrier to prevent color mixing between pixels is formed relatively low at 1 to 2 μm, but since the height of the pixels of the micro display panel is 5 μm or more, the black pixel definition layer (230) must be formed at a height greater than the pixel height, as the pattern acts as a barrier.

[0076] Black photocurable resins contain a black mill base, which is present in the range of 10 to 80 weight percent of the photocurable resin and acts as an important factor affecting the overall physical properties of the photocurable resin. This black mill base may include pigments, binders, dispersants, and dispersion aids.

[0077] To prevent color mixing between subpixels of a microdisplay panel, a black mill base with an optical density of 1.5㎛ or greater must be manufactured, and for uniform curing of the upper and lower parts of the pattern acting as a barrier of 5㎛ or greater, 70mJ / cm² 2 The photocurable resin must be able to photosensitize even at lower energies.

[0078] FIG. 11 is a flowchart illustrating a surface modification process of carbon black according to one embodiment of the present invention, and FIG. 12 is an illustrative diagram illustrating a surface modification process of carbon black according to one embodiment of the present invention.

[0079] Referring to FIG. 11, the surface modification process of carbon black involves mixing approximately 94g of ethylene glycol monoethyl ether acetate (PGMEA, Propylene Glycol Methyl Ether Acetate) and 2g of ammonia water (NH4OH), stirring the mixture at 70°C for 10 minutes, adding approximately 10g of carbon black, stirring at 70°C for 1 hour, and performing centrifugation and redispersion processes with PGMEA (S110~S150).

[0080] Subsequently, a mixture of carbon black / PGMEA and NH4OH can be stirred at 70°C for 10 minutes, then approximately 2g of silane is added and stirred at 70°C for 2 hours, and a centrifugation and redispersion process with PGMEA is performed to produce a black mill base (S160~S200).

[0081] As illustrated in FIG. 12, when the pixel definition layer (230) uses black carbon as a light shielding agent, a surface modification process is required to control black carbon nanoparticles and improve dispersion characteristics. Oxygen present on the surface of carbon black exists mainly in the form of -COOH (carboxylic acid) functional groups or -OH (alcohol) functional groups exhibiting weak acidity. The surface modification process of carbon black can convert carbon black into -OH-rich carbon black by chemical decomposition using an alcohol lysis reaction, and then convert the -OH-rich carbon black into surface-treated carbon black by silane treatment.

[0082] FIG. 13 is a diagram illustrating a reflection phenomenon caused by external light in a micro display panel to which a micro LED module according to one embodiment of the present invention is applied, and FIG. 14 is a diagram showing the results of measuring the light intensity according to distance for a panel to which a black pixel definition layer according to one embodiment of the present invention is applied and a panel before application.

[0083] As shown in FIG. 13, a panel with a conventional transparent pixel definition layer has reduced display visibility because external light is reflected from the driving circuit, such as a metal electrode, such as a TFT electrode pad or an LED electrode pad, and the TFT layer, etc., provided on the inside (a). However, a panel with a black pixel definition layer applied according to the present invention does not reflect external light from the electrode, driving circuit, electrical circuit layer, etc. on the inside, and can be seen to improve the problem of reduced visibility caused by external light.

[0084] In addition, FIG. 14 is a graph showing the light intensity when currents of 5mA, 7mA, and 10mA are applied, respectively, assuming that an LED with a conventional transparent pixel definition layer is used as the Ref light source and an LED module with a black pixel definition layer is used as the BM light source. As shown in FIG. 14, the conventional transparent pixel definition layer uses photosensitive polyimide (PSPI) with a low dielectric constant, but the black pixel definition layer applied in the present invention acts as a barrier separating the space between sub-pixels, and it can be seen that the optical density characteristics are improved by more than 50%, thereby improving color reproduction rate, resolution, brightness, and power efficiency.

[0085] A black pixel definition layer (230) with improved optical density can replace the role of a polarizer in a micro-display panel, drastically reduce external light reflectivity, and reduce the thickness by the same amount as a polarizer, thereby reducing the overall thickness of the micro-display panel and shortening the anti-reflection coating process.

[0086]

[0087] Although FIGS. 6 and FIGS. 11 describe each process as being executed sequentially, this is merely an illustrative explanation of the technical concept of one embodiment of the present invention. In other words, a person skilled in the art to which one embodiment of the present invention belongs can modify and adapt the process in various ways, such as changing the order described in each figure or executing one or more of the processes in parallel, without departing from the essential characteristics of one embodiment of the present invention; therefore, FIGS. 6 and FIGS. 11 are not limited to a chronological order.

[0088] Meanwhile, the processes illustrated in FIGS. 6 and FIGS. 11 can be implemented as computer-readable code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices in which data that can be read by a computer system is stored. That is, a computer-readable recording medium includes storage media such as magnetic storage media (e.g., ROM, floppy disk, hard disk, etc.) and optical reading media (e.g., CD-ROM, DVD, etc.). In addition, the computer-readable recording medium can be distributed across networked computer systems, allowing computer-readable code to be stored and executed in a distributed manner.

[0089] The above description is merely an illustrative explanation of the technical concept of the present embodiment, and a person skilled in the art to which the present embodiment belongs would be able to make various modifications and variations within the scope of the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain, not limit, the technical concept of the present embodiment, and the scope of the technical concept of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present embodiment.

[0090]

[0091] CROSS-REFERENCE TO RELATED APPLICATION

[0092] This patent is the result of research conducted with funding from the government of the Republic of Korea (Ministry of Trade, Industry and Energy) and supported by the Korea Institute of Industrial Technology Planning and Evaluation (Detailed Project No.: 20016195, Project Title: Development of Common Core Material Technology for Quantum Dot Displays).

[0093] This patent is the result of research conducted with funding from the government of the Republic of Korea (Ministry of SMEs and Startups) and support from the Korea Institute of Technology Information Promotion (KITEIPA) (Detailed Project No.: S3305098, Project Title: Development of Pure Black PDL (pixel definition layer) material and process technology for micro LED display panels).

[0094]

[0095] If this patent application claims priority under Section 119(a) of the U.S. Patent Act (35 USC § 119(a)) for Korean Patent Application No. 10-2024-0126923 filed on [Date] 19, 2024, all of the contents thereof shall be incorporated into this patent application by reference. Furthermore, if this patent application claims priority in countries other than the United States for the same reasons as above, all of the contents thereof shall be incorporated into this patent application by reference.

Claims

1. Regarding micro LED modules, A substrate on which R, G, and B micro LEDs are arranged; An electrical circuit layer disposed on one surface of the above substrate and electrically connected to the micro LED; A pixel defined layer disposed on the above electrical circuit layer and including a pattern formed at predetermined intervals to define the light-emitting region of each micro LED and to separate each micro LED from one another; and It includes a protective layer formed in a manner that covers the above-mentioned micro LED and the above-mentioned pixel definition layer, The above pixel definition layer is, A micro LED module characterized by comprising at least one black light-shielding agent among carbon black, CNT (carbon nanotube), black pigment, and black dye.

2. In Paragraph 1, The above pixel definition layer is, A micro LED module characterized by the above-mentioned light shielding agent having a photoinitiator and a binder mixed in a preset ratio.

3. In Paragraph 1, The above pixel definition layer is, When each micro LED is formed with a first height (h, h>0) or greater, a pattern is formed between each micro LED with a first line width (L) or less. A micro LED module characterized in that the first line width (L) is set to be greater than or equal to the first height and less than or equal to twice the first height.

4. In Paragraph 1, A micro LED module characterized in that the above-mentioned pre-set interval is a uniform interval.

5. A micro display panel characterized by the fact that a plurality of micro LED modules according to any one of claims 1 to 4 are combined and implemented in a tiling form.

6. A first step of forming a substrate on the R, G, and B micro LEDs such that R, G, and B micro LEDs are arranged on an upper surface and the R, G, and B micro LEDs are electrically insulated from each other; A second step of forming an electrical circuit layer formed on the substrate and electrically connected to each of the R, G, and B micro LEDs; and A third step of forming a pixel defined layer disposed on the above electrical circuit layer, comprising a pattern formed at predetermined intervals to define the light-emitting region of each micro LED and to separate each micro LED from one another; and A fourth step of forming a protective layer in a manner that covers the micro LED and the pixel definition layer, wherein The above pixel definition layer is, A method for manufacturing a micro LED module characterized by comprising at least one black light-shielding agent among carbon black, CNT (carbon nanotube), black pigment, and black dye.

7. In Paragraph 6, The above pixel definition layer is, A method for manufacturing a micro LED module characterized by forming a black photocurable resin by mixing a binder, a monomer having an organic-inorganic hybrid structure, a photoinitiator, a dispersant, and a solvent in a predetermined ratio with the above-mentioned light shielding agent.

8. In Paragraph 7, The above photocurable resin is, A method for manufacturing a micro LED module characterized by having photocurable substituents and thermocurable substituents introduced to provide photocurable properties.

9. In Paragraph 7, The above photocurable resin is, 70 mJ / cm² 2 A method for manufacturing a micro LED module characterized by being formed to be photosensitive at the following energy.

10. In Paragraph 7, The above third step is, A process of forming a photoresist by coating the above-mentioned black photocurable resin onto a substrate; A process of exposing and developing the above photoresist; and A method for manufacturing a micro LED module characterized by having a process of curing a developed photoresist to form a pixel definition layer.

11. In Paragraph 10, The process of exposing and developing the above-mentioned photoresist is, A method for manufacturing a micro LED module characterized by forming a pattern using a mask having a pre-set spacing.

12. In Paragraph 11, The first line width (L) of the above pattern is, A method for manufacturing a micro LED module characterized in that, when each micro LED is formed at a first height (h, h>0), the height is set to be greater than or equal to the first height and less than or equal to twice the first height.

13. In Paragraph 6, The above photoinitiator is, A method for manufacturing a micro LED module characterized by having ultraviolet absorption characteristics in a wavelength range of 365 nm or more.

14. A micro display panel characterized by being implemented by combining a plurality of micro LED modules manufactured according to the manufacturing method of any one of claims 7 to 13 in a tiled form.

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