LED Display Having EMI Shielding Function

Abstract

The present invention relates to an LED display panel having an EMI shielding function. More specifically, it relates to a technology that efficiently reduces electromagnetic interference generated by LED modules corresponding to components of the display panel, thereby satisfying electromagnetic compatibility standards and increasing the reliability of the modules. That is, the present invention relates to an LED display comprising an LED module having an LED element mounted thereon and a display case housing the LED module, wherein the LED display comprises a shielding member disposed on the rear surface of the LED module, the shielding member is configured to reduce electromagnetic waves generated from the LED module by including at least one shielding absorption layer formed of a carbon-based composite material and having a porous network structure.

Description

Technology Field

[0001] The present invention relates to an LED display panel having an EMI (Electro Magnetic Interference) shielding function. More specifically, it relates to a technology that efficiently reduces electromagnetic interference (EMI) generated from LED modules corresponding to components of the display panel, thereby satisfying electromagnetic compatibility standards and increasing the reliability of the modules. Background Technology

[0003] Generally, an LED display is an electronic device comprising multiple LED elements, a power supply, driver circuits, and control circuits to drive them. It is widely used in various fields, such as traffic guidance, advertising, and information display. Due to the trend toward higher brightness and larger sizes, the driving current and circuit integration density of these LED displays are increasing, and electromagnetic waves across various frequency bands are generated during operation.

[0004] In particular, electromagnetic radiation tends to concentrate in the rear area where the power supply and driver circuits of LED modules are located. This radiation is emitted outside the display panel, causing interference with surrounding electronic devices or making it difficult to meet Electromagnetic Compatibility (EMC) standards. In fact, it has been confirmed that the rear of LED modules exhibits relatively higher electromagnetic emission characteristics than the front, which is because the sources of electromagnetic radiation are primarily concentrated in the rear circuitry.

[0005] To address these issues, conventional electromagnetic shielding structures utilizing metal plates or metal coatings have been employed. However, these metal-based shielding methods increase the weight of the structure and raise manufacturing costs. Furthermore, due to their characteristic of reflecting rather than absorbing electromagnetic waves, they have limitations in that reflected waves cause re-interference. Additionally, metal shielding structures are difficult to apply to electronic display structures with complex shapes, which limits design flexibility.

[0006] Therefore, there is a need for a new type of EMI shielding technology that is lightweight, can effectively reduce electromagnetic waves, and minimize secondary interference caused by reflection. In particular, there is an urgent need to develop a shielding structure optimized for the rear area of ​​LED modules where electromagnetic waves are concentrated. Prior art literature

[0008] Registered Patent No. 10-0877294 (December 26, 2008) Registered Patent No. 10-1439494 (September 30, 2010) Registered Patent No. 10-0985828 (September 2, 2014) The problem to be solved

[0009] The present invention aims to solve the problem of concentrated electromagnetic wave emission in the rear area where the power supply and driver circuit of an LED module are placed, and to improve the problem of interference with surrounding electronic devices and non-compliance with electromagnetic compatibility standards caused by said electromagnetic waves. In particular, the purpose is to provide a new type of EMI shielding structure that can reduce secondary interference caused by internal re-reflection by inducing absorption and scattering of electromagnetic waves, moving away from conventional metal shielding methods that simply reflect electromagnetic waves.

[0010] In addition, the present invention aims to provide an EMI shielding structure using a carbon-based composite material that solves the problems of increased weight and manufacturing costs associated with metal-based shielding structures and ensures excellent shielding performance while being lightweight.

[0011] Furthermore, the purpose is to enhance the design freedom of LED display panels through a structure that can be selectively applied in response to the location of electromagnetic wave generation, and to improve the reliability of the entire system by ensuring stable satisfaction of electromagnetic compatibility standards. means of solving the problem

[0013] The present invention relates to an LED display board comprising an LED module having an LED element mounted thereon and a display board case accommodating the LED module, wherein the LED module includes a shielding member disposed on the rear surface of the LED module, the shielding member is formed of a carbon-based composite material and is configured to reduce electromagnetic waves generated from the LED module by including at least one shielding absorption layer having a porous network structure.

[0014] In addition, the carbon-based composite material of the shielding member is characterized by comprising a shielding absorption layer comprising one or more of carbon fibers, nanocarbon tubes, polypropylene (PP), polyethylene terephthalate (PET), and thermoplastic resins such as silicone resin, and an auxiliary shielding layer comprising one or more of metal particles such as iron (Fe) and copper (Cu).

[0015] In addition, the shielding member is characterized by being configured to form a porous structure in which carbon fibers are intertwined so that electromagnetic waves are multiplely scattered and absorbed inside.

[0016] In addition, the shielding member is characterized by being formed in a multilayer structure in which a shielding absorption layer containing a carbon component and an auxiliary shielding layer containing conductive metal particles are laminated.

[0017] Finally, the shielding member is positioned to correspond to an area adjacent to an electromagnetic wave source, such as a power supply unit, a data input unit, or a data output unit installed on the rear side of the LED module, and is configured to selectively shield an area where electromagnetic wave emission is concentrated by being positioned adjacent to or covering at least one of the power supply unit, the data input unit, or the data output unit. Effects of the invention

[0019] According to the present invention, electromagnetic waves generated from an LED module can be effectively reduced through a shielding member made of a carbon-based composite material disposed on the rear surface of the LED module. In particular, by combining the electromagnetic wave absorption function of the carbon component with the multiple scattering action of the porous network structure, shielding centered on absorption and attenuation is achieved rather than a method of simple reflection of electromagnetic waves, thereby ensuring stable EMI reduction performance across various frequency bands.

[0020] In addition, the shielding member is selectively positioned in areas adjacent to electromagnetic wave sources, such as power supply units, data input units, and data output units, thereby efficiently shielding areas where electromagnetic waves are concentrated. Accordingly, shielding efficiency can be maximized while preventing unnecessary shielding of the entire surface area, and the effects of reduced material usage and weight reduction can be achieved simultaneously.

[0021] Furthermore, the shielding member described above can simultaneously improve electromagnetic wave absorption and attenuation performance through a structure combining a carbon-based composite material and a metal component, and can achieve excellent shielding performance even with a relatively thin thickness, thus not hindering the utilization of internal space in the LED display. In addition, electromagnetic waves are repeatedly scattered and absorbed internally by the porous structure, thereby effectively suppressing the emission of electromagnetic waves to the outside.

[0022] Furthermore, the shielding member may be structured to be snap-fitted into a terminal formed on the rear surface of the LED module, allowing for easy installation and removal without the need for separate fastening means; consequently, the assembly process is simplified and workability is improved. Additionally, the ease of replacing or reinstalling the shielding member during maintenance enhances management convenience.

[0023] Consequently, the present invention is significant in that it provides an EMI shielding structure for LED display panels that simultaneously satisfies electromagnetic shielding performance, structural simplicity, lightweight design, and ease of maintenance. Brief explanation of the drawing

[0025] FIG. 1 is a schematic diagram showing the structure of an LED display board having an EMI shielding function according to the present invention. FIG. 2 is a drawing showing the combined structure of a shielding member applied to the present invention. FIG. 3 is a drawing showing an embodiment in which a shielding member according to the present invention is composed of a plurality of layers. Figure 4 is a scanning electron microscope (SEM) image showing the cross-sectional structure of a prototype of the present invention. FIG. 5 is a drawing showing another embodiment of a shielding member according to the present invention. Specific details for implementing the invention

[0026] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Furthermore, in describing the present invention, detailed descriptions of related known functions or configurations are omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the present invention.

[0027] The present invention relates to an LED display board comprising an LED module (100) having an LED element (110) mounted thereon and an LED display board case (200) accommodating the LED module (100), and is characterized by including a shielding member (300) disposed on the rear side of the LED module (100).

[0028] The installation size of the above-mentioned display case (200) and LED module (100) may vary depending on the specifications of the display. The LED module (100) has a plurality of LED elements (110) mounted on the front surface of a PCB board, and the rear surface of the PCB board includes a power supply unit that supplies power to each LED element (110), a data input unit that receives data and control signals from the outside, a data output unit that transmits the received signals to another module, and a driving circuit that is electrically connected to the above components to control the lighting state of the LED elements (110). Additionally, a communication interface or a control module may be provided as needed.

[0029] The shielding member (300) of the present invention is formed of a carbon-based composite material and is characterized by being configured to reduce electromagnetic waves generated from the LED module (100) by including at least one shielding absorption layer having a porous network structure.

[0030] The above carbon-based composite material may be composed of a shielding absorption layer (310) comprising one or more of carbon fibers, carbon nanotubes, polypropylene (PP), polyethylene terephthalate (PET), and thermoplastic resins such as silicone resin, and an auxiliary absorption layer (320) comprising one or more of metal particles such as iron (Fe) and copper (Cu), and each of the above components may be formed to be combined with each other to exhibit electromagnetic wave attenuation characteristics.

[0031] In addition, the shielding member (300) can be configured to form a porous network structure so that when electromagnetic waves enter the shielding member (300), multiple scattering occurs inside, and the energy of the electromagnetic waves is gradually attenuated during this process. In particular, the structure in which carbon fibers are intertwined plays a role in increasing absorption efficiency by complicating the propagation path of the electromagnetic waves.

[0032] In addition, the shielding member (300) may be formed as a single-layer structure, but as shown in FIG. 3, it may be formed as a multi-layer structure in which a plurality of functional layers are stacked. For example, the electromagnetic shielding performance can be further improved by stacking a shielding absorption layer (310) containing carbon components and an auxiliary shielding layer (320) containing conductive metal particles.

[0033] Meanwhile, the shielding member (300) is preferably positioned to correspond to an area adjacent to an electromagnetic wave source, such as a power supply unit, a data input unit, or a data output unit installed on the rear side of the LED module (100), and is configured to selectively shield an area where electromagnetic wave emission is concentrated by being positioned adjacent to or covering at least one of the power supply unit, the data input unit, or the data output unit.

[0034] By installing it partially only in the area where electromagnetic waves are concentrated, the use of unnecessary shielding members (300) can be minimized, thereby reducing the overall weight of the structure and achieving a reduction in manufacturing costs due to the reduced use of materials. In addition, since shielding is selectively performed in close proximity to the source of electromagnetic waves, the shielding efficiency can be improved relative to the same area, and there is an advantage of maintaining heat dissipation characteristics without excessively interfering with the heat generation structure inside the display panel. Furthermore, efficient placement is possible even within a limited space, allowing for flexible application to LED display panels of various sizes, and there is an effect that the replacement or relocation of the shielding members (300) is easy during maintenance.

[0035] When the shielding member (300) of the present invention is installed in an area adjacent to an electromagnetic wave source, such as the power supply unit, data input unit, and data output unit, the shape of the shielding member (300) is preferably formed in a generally rectangular plate shape so that it can be fitted and coupled to a terminal protruding from the rear surface of the LED module (100) as shown in FIG. 2. At this time, a through hole of a size corresponding to the outer shape and specifications of the terminal is formed in the central part of the shielding member (300), so that the shielding member (300) can be configured to be aligned in position as it passes through the terminal and is seated.

[0036] When configured in this way, the position fixation and connection of the shielding member (300) can be stably achieved simply by inserting it into the terminal using a snap-fit ​​method, without the need for additional separate fastening members or fixing structures. Accordingly, the assembly process is simplified and workability is improved, and structural effects can be expected such that disassembly and replacement are also easy, thereby increasing the convenience of maintenance.

[0038] [Example]

[0039] This embodiment relates to the composition and structure of a carbon-based composite EMI shielding material applied to a shielding member (300) for an LED display panel.

[0040] The shielding member (300) of the present embodiment is formed from a carbon-based composite material and is composed of a composition comprising 30 to 40 parts by weight of carbon (C), 25 to 35 parts by weight of silicon (Si), 1 to 5 parts by weight of iron (Fe), and 1 to 3 parts by weight of copper (Cu) relative to the total weight. Additionally, the composition may partially exist in the form of an oxide containing oxygen (O), which may be included in a state combined with silicon and metal components.

[0041] The reason for limiting the numerical range as described above is as follows. First, if the carbon (C) content is less than 30 parts by weight, the electromagnetic wave absorption performance is not sufficiently exhibited, and if it exceeds 40 parts by weight, problems such as reduced mechanical strength or decreased formability of the material may occur. Therefore, the range was limited as described above in order to simultaneously secure electromagnetic wave absorption performance and structural stability.

[0042] The silicon (Si) component acts as a matrix and binder. If the amount is less than 25 parts by weight, it is difficult to stably bond carbon and metal particles, which may lead to a decrease in structural integrity. If the amount exceeds 35 parts by weight, the relative proportion of the conductive component decreases, raising concerns that EMI shielding performance may be degraded. Accordingly, the above range was set.

[0043] Metallic components such as iron (Fe) and copper (Cu) play a role in improving electromagnetic wave attenuation and absorption performance by imparting conductivity. If the iron content is less than 1 weight part, the effect of improving conductivity is negligible, and if it exceeds 5 weight parts, absorption-based shielding performance may deteriorate due to increased material weight and cost, as well as unnecessary increased reflection. Additionally, in the case of copper, if it is less than 1 weight part, the effect of increasing electromagnetic wave loss is insufficient, and if it exceeds 3 weight parts, problems may arise where reflection characteristics increase and manufacturing costs rise due to excessive conductivity.

[0044] The carbon-based composite material configured in this manner implements a composite shielding mechanism that absorbs and scatters electromagnetic waves through the combined action of electromagnetic wave absorption by the carbon component, electromagnetic wave attenuation and loss increase by the metal component, and multiple scattering by the porous network structure formed by carbon fibers or carbon particles.

[0045] Accordingly, the shielding member (300) of the present embodiment can effectively reduce electromagnetic waves generated from the rear portion of the LED module (100), and in particular, can secure stable EMI shielding performance in various frequency bands. In addition, excellent shielding performance can be achieved even with a relatively thin thickness, thereby providing the effect of efficient electromagnetic wave reduction while maintaining the design freedom of the internal structure of the display panel.

[0046] FIG. 4 is a photograph showing the cross-sectional structure of a prototype of the present invention as described above, enlarged under a microscope. As a result of measuring the electromagnetic shielding performance of a prototype having the cross-sectional structure described above, the S21 parameter value was found to be at the level of -90dB, which indicates a very excellent shielding performance in which most of the electromagnetic waves are attenuated as they pass through the shielding member (300) and are not substantially transmitted.

[0047] In addition, it was confirmed that when the carbon-based shielding structure is applied to the rear portion of the LED module (100), the amount of electromagnetic waves emitted is significantly reduced compared to when the shielding member (300) is not applied. This means that the shielding member (300) of the present invention effectively acts in the area adjacent to the source of electromagnetic waves, thereby efficiently suppressing electromagnetic waves emitted to the outside.

[0048] FIG. 5 is a cross-sectional view showing another embodiment of a shielding member (300) according to the present invention. Referring to the above, an insulating adhesive layer (330) that adheres to a target substrate and includes a silicone component may be further formed on the lower part of the shielding member (300). At this time, the insulating adhesive layer (330) may include a carbon component to assist in electromagnetic wave absorption, but is characterized by including it in a relatively smaller weight ratio than the carbon component content included in the shielding absorption layer (310) in order to prevent an electrical short circuit with the substrate.

[0049] In addition, a plurality of protrusions (340) are integrally formed on the upper surface of the shielding member (300) to increase the contact area with air and facilitate heat dissipation. Furthermore, it is preferable that the upper surface of the shielding member (300) on which the protrusions (340) are formed be coated with a heat dissipation layer (350) as shown in the drawing.

[0050] The heat dissipation layer (350) may be formed by coating in a form in which an inorganic filler with excellent thermal conductivity is dispersed within a polymer binder. Specifically, the inorganic filler is composed of a ceramic material having both insulating and thermal conductive properties, such as boron nitride (BN), aluminum oxide (Al2O3), or aluminum nitride (AlN), thereby preventing short circuits with an external conductor and simultaneously performing the function of rapidly conducting heat transferred from the inside to the protrusion (340).

[0051] At this time, the protrusion (340) performs the function of a heat dissipation fin that physically expands the surface area of ​​the heat dissipation layer (350) to increase the heat exchange efficiency with air, and the binder component of the heat dissipation layer (350) is preferably composed of a resin composition with excellent interfacial bonding strength with the main shielding layer below, thereby providing structural stability that does not peel off even under repeated bending or thermal shock environments. As a result, the shielding member (300) according to the present invention forms a multifunctional laminated structure in which adhesion to the substrate through the bottom insulating adhesion layer (330), electromagnetic wave absorption through the shielding absorption layer (310), and high-efficiency heat discharge through the top heat dissipation layer (350) and the protrusion (340) are optimized and performed layer by layer.

[0052] Although the present invention has been described above with reference to the embodiments, it is understood that various modifications are possible within the scope of the technical spirit of the present invention. Explanation of the symbols

[0054] 100 : LED module 110 : LED element 200 : LED display case 300 : Shielding member 310: Shielding absorption layer 320: Auxiliary shielding layer 330: Insulating adhesion layer 340: Protrusion 350 : Heat dissipation layer

Claims

Claim 1 An LED display board comprising an LED module (100) having an LED element (110) mounted thereon and an LED display board case (200) housing the LED module (100), wherein the LED module (100) is configured to reduce electromagnetic waves generated from the LED module (100) by including at least one shielding absorption layer (310) formed of a carbon-based composite material and having a porous network structure, wherein the shielding member (300) has a plurality of protrusions (340) integrally formed protruding from the upper surface of the shielding absorption layer (310), and the upper surface of the protrusions (340) is coated as a heat dissipation layer (350) in a form in which an inorganic filler with excellent thermal conductivity is dispersed within a polymer binder, and the lower surface of the shielding absorption layer (310) is an insulating layer including a silicone component that adheres to a target substrate. An LED display board having an EMI shielding function characterized by the formation of an adhesive layer (330). Claim 2 An LED display having an EMI shielding function, characterized in that, in claim 1, the carbon-based composite material of the shielding member (300) comprises a shielding absorption layer (310) containing one or more of carbon fibers, carbon nanotubes, polypropylene (PP), polyethylene terephthalate (PET), and silicone resin, and an auxiliary absorption layer (320) containing one or more of metal particles. Claim 3 An LED display board having an EMI shielding function, characterized in that, in claim 1, the shielding member (300) is configured to form a porous structure in which carbon fibers are intertwined so that electromagnetic waves are multiplely scattered and absorbed inside. Claim 4 An LED display having an EMI shielding function, characterized in that, in claim 1, the shielding member (300) is formed in a multilayer structure in which a shielding absorption layer (310) containing a carbon component and an auxiliary shielding layer (320) containing conductive metal particles are laminated. Claim 5 delete Claim 6 An LED display having an EMI shielding function according to claim 1, wherein the shielding member (300) is positioned to correspond to an area adjacent to an electromagnetic wave source, such as a power supply unit, a data input unit, or a data output unit installed on the rear side of an LED module (100), and is configured to selectively shield an area where electromagnetic wave emission is concentrated by being positioned adjacent to or covering at least one of the power supply unit, the data input unit, or the data output unit.

Images