Antenna stack and display device

Abstract

The present invention provides an antenna stack and a display device. The antenna stack according to an embodiment may include: a display panel including an electrode structure; a dielectric layer disposed on the display panel; an antenna conductive layer disposed on the dielectric layer; and a lower ground layer disposed on a lower side portion of the display panel and having a lower resistance than the display panel.

Description

Technical Field

[0001] The present invention relates to an antenna stack and a display device. Background Art

[0002] Recently, with the development of the information society, wireless communication technologies such as Wi-Fi and Bluetooth are implemented in the form of smart phones, for example, by being combined with display devices. In this case, an antenna can be coupled to the display device to perform a communication function.

[0003] Recently, as mobile communication technologies have become more and more advanced, it has been necessary to couple an antenna for performing communication in the ultra-high frequency band to a display device. In addition, since thin, highly transparent, and high-resolution display devices such as transparent displays and flexible displays have been developed recently, it has been necessary to develop an antenna with improved transparency and flexibility.

[0004] As the screen of the display device increases, there is a tendency that the space or area for a bezel portion or a light-shielding portion is decreasing. In this case, the space or area in which the antenna can be embedded is also limited, whereby a radiator included in the antenna for transmitting and receiving signals may overlap with the display area of the display device. Therefore, the image of the display device may be blocked by the radiator of the antenna, or the radiator may be seen by the user, resulting in a decrease in image quality.

[0005] Therefore, there is a need for an antenna design that prevents the user from seeing the radiator and enables high-frequency communication with a desired antenna gain in a limited space. Summary of the Invention

[0006] An object of the present invention is to provide an antenna stack and a display device including the antenna stack.

[0007] To achieve the above object, the present invention adopts the following technical solutions.

[0008] 1. An antenna stack, comprising: a display panel including an electrode structure; a dielectric layer provided on the display panel; an antenna conductive layer provided on the dielectric layer; and a lower ground layer provided on a lower side portion of the display panel and having a lower resistance than the display panel.

[0009] 2. The antenna stack according to 1 above, further comprising: a lower dielectric layer provided between the display panel and the lower ground layer.

[0010] 3. The antenna stack according to 2 above, wherein the thickness of the lower dielectric layer is 50 μm to 800 μm.

[0011] 4. The antenna stack according to 1 above, wherein the distance between the electrode structure and the lower ground layer is 50 μm to 800 μm.

[0012] 5. According to the antenna stack of item 1 above, the resistance of the display panel is 10 Ω / sq or less.

[0013] 6. According to the antenna stack of item 1 above, the resistance of the lower ground layer is 0.5 Ω / sq or less.

[0014] 7. According to the antenna stack of item 1 above, it further includes: a first adhesive layer disposed between the antenna conductive layer and the dielectric layer; and a second adhesive layer disposed between the dielectric layer and the display panel.

[0015] 8. According to the antenna stack of item 1 above, the antenna conductive layer includes a radiator and a transmission line connected to the radiator, and the lower ground layer at least partially overlaps with the radiator.

[0016] 9. A display device, which includes the antenna stack of the above embodiment.

[0017] 10. According to the display device of item 9 above, the lower ground layer is provided as one of the SUS board, heat sink, digital converter, electromagnetic shielding layer, pressure sensor, and fingerprint sensor of the display device.

[0018] In the antenna stack according to an embodiment, a dielectric layer can be formed on the display panel, an antenna conductive layer can be formed on the dielectric layer, and a lower ground layer can be formed on the lower side of the display panel. The display panel and the lower ground layer can form a ground composite structure to improve the signal characteristics of the antenna.

[0019] The lower ground layer can be provided as a functional layer for implementing the intelligent function of the display device. Therefore, the space utilization rate can be improved and the requirement for reducing the antenna thickness can be achieved.

[0020] The lower ground layer can include a metal having a lower resistance than the display panel. Thus, the lower ground layer can supplement and improve the performance of the display panel as a ground layer of the display panel. Therefore, the signal characteristics of the antenna can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features, and other advantages of the present invention will be more clearly understood through the following detailed description in conjunction with the drawings, in which:

[0022] Figure 1 is a schematic cross-sectional view showing an antenna stack according to an embodiment;

[0023] Figure 2 is a schematic cross-sectional view showing a display panel according to an embodiment;

[0024] Figure 3 is a schematic plan view showing an antenna conductive layer according to an embodiment;

[0025] Figure 4 is a schematic cross-sectional view showing an antenna stack according to another embodiment;

[0026] Figure 5 is a schematic cross-sectional view showing an antenna stack according to another embodiment; and

[0027] Figure 6 is a schematic plan view showing a display device according to one embodiment. Detailed Embodiments

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, since the views attached to the present invention are shown only to easily understand the technical spirit of the present invention having the above-described summary of the invention and show one of the various preferred embodiments of the present invention, it should not be construed as being limited to the description shown in the views.

[0029] The antenna stack described herein includes a patch antenna or a microstrip antenna manufactured in the form of a transparent thin film, and can be applied to communication devices such as high-frequency or ultra-high-frequency (e.g., 3G, 4G, 5G or higher) mobile communication, Wi-Fi, Bluetooth, near field communication (NFC), global positioning system (GPS), etc.

[0030] Figure 1 is a schematic cross-sectional view showing an antenna stack according to one embodiment.

[0031] Referring to Figure 1 According to one embodiment, the antenna stack 100 may include a display panel 110, a dielectric layer 120, an antenna conductive layer 130, and a lower ground layer 140.

[0032] The display panel 110 includes a metal, a metal alloy, or a metal oxide having a predetermined conductivity, and may be coupled to the antenna conductive layer 130 with a dielectric layer 120 interposed therebetween to form a capacitance or an inductance. Thus, vertical radiation characteristics can be achieved in the antenna stack 100.

[0033] According to one embodiment, the display panel 110 may include a liquid crystal display (LCD) panel, a light emitting diode (LED) panel, an organic light emitting diode (OLED) panel, a quantum dot light emitting diode (QLED) panel, etc.

[0034] According to one embodiment, the display panel 110 (more specifically, Figure 2The electrode structure 210) can at least partially overlap with the antenna conductive layer 130 in the thickness direction of the antenna stack 100. Accordingly, the display panel 110 can be set as a ground portion of the antenna conductive layer 130. For example, the antenna conductive layer 130 and the display panel 110 can be coupled to each other to transmit and receive antenna signals.

[0035] According to one embodiment, the display panel 110 (more specifically, Figure 2 the electrode structure 210) can completely overlap with the antenna conductive layer 130. In this case, the coupling area between the display panel 110 and the antenna conductive layer 130 can be increased, so that the gain and efficiency of the antenna can be increased.

[0036] According to one embodiment, the display panel 110 (more specifically, Figure 2 the electrode structure 210) can have a resistance of 10 Ω / sq or less. The display panel 110 can be formed by laminating a plurality of conductive layers in a plurality of layers in order to supplement physical properties (such as adhesiveness, etc.).

[0037] The dielectric layer 120 can be provided on the display panel 110. For example, the dielectric layer 120 can be in contact with the display panel 110, or another member can be inserted between the dielectric layer 120 and the display panel 110.

[0038] The dielectric layer 120 can include an insulating material having a predetermined dielectric constant. According to one embodiment, the dielectric layer 120 can include an inorganic insulating material such as glass, silicon oxide, silicon nitride, or metal oxide, or an organic insulating material such as epoxy resin, acrylic resin, or imide resin. The dielectric layer 120 can be used as a thin film substrate on which the antenna conductive layer 130 is formed.

[0039] According to one embodiment, the transparent film may be provided as the dielectric layer 120. In this case, the transparent film may include: polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, etc.; cellulose resins such as diacetyl cellulose, triacetyl cellulose, etc.; polycarbonate resins; acrylic resins such as poly(methyl)methacrylate, poly(methyl)acrylate, etc.; styrene resins such as polystyrene, acrylonitrile-styrene copolymer, etc.; polyolefin resins such as polyethylene, polypropylene, cyclic polyolefin or polyolefin having a norbornene structure, ethylene-propylene copolymer, etc.; vinyl chloride resins; amide resins such as nylon, aromatic polyamide; imide resins; polyether sulfonic acid resins; sulfonic acid resins; polyether ether ketone resins; polyphenylene sulfide resins; vinyl alcohol resins; vinylidene chloride resins; vinyl butyral resins; allylated resins; polyoxymethylene resins; thermoplastic resins such as epoxy resins, etc. These compounds may be used alone or in combination of two or more. In addition, a transparent film made of a thermosetting resin such as (meth)acrylate, urethane, acrylic urethane, epoxy resin, silicone, etc. or an ultraviolet curable resin may be used as the dielectric layer 120.

[0040] According to one embodiment, an adhesive film such as an optically clear adhesive (OCA) or an optically clear resin (OCR) may also be included in the dielectric layer 120.

[0041] According to one embodiment, the dielectric layer 120 may be formed as a substantially single layer, or may be formed as a multi-layer structure of two or more layers.

[0042] A capacitance or an inductance may be formed between the antenna conductive layer 130 and / or the display panel 110 through the dielectric layer 120, thereby adjusting the frequency band that can be driven or induced by the antenna stack 100. When the dielectric constant of the dielectric layer 120 exceeds about 12, the driving frequency is excessively reduced, so that the antenna driving at a desired high frequency band may not be achieved. Therefore, according to one embodiment, the dielectric constant of the dielectric layer 120 may be adjusted to a range of about 1.5 to 12, preferably 2 to 12.

[0043] According to one embodiment, the encapsulation layer 220 of the display panel 110, which will be described below with reference to Figure 2 may be provided as the dielectric layer 120.

[0044] According to one embodiment, the thickness of the dielectric layer 120 may be from 100 μm to 250 μm. When the thickness of the dielectric layer 120 is less than 100 μm, the distance between the antenna conductive layer 130 and the display panel 110 may be too close. In this case, the gain and efficiency of the antenna may be reduced. Additionally, when the thickness of the dielectric layer 120 exceeds 250 μm, the flexibility characteristics may deteriorate due to the increased thickness of the antenna stack 100. Preferably, the thickness of the dielectric layer 120 is from 150 μm to 250 μm, and in this case, the gain and efficiency of the antenna can be increased to more than 5 dB and more than 60%, respectively.

[0045] The antenna conductive layer 130 may be disposed on the dielectric layer 120. For example, the antenna conductive layer 130 may be in contact with the dielectric layer 120, or another member may be inserted between the antenna conductive layer 130 and the dielectric layer 120.

[0046] The antenna conductive layer 130 may include a low-resistance metal, such as 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 thereof. They may be used alone or in combination of two or more. For example, the antenna conductive layer 130 may include silver (Ag) or a silver alloy (e.g., silver-palladium-copper (APC) alloy) to achieve low resistance. As another example, considering low resistance and a fine linewidth pattern, the antenna conductive layer 130 may include copper (Cu) or a copper alloy (e.g., copper-calcium (CuCa) alloy).

[0047] According to one embodiment, the antenna conductive layer 130 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), zinc oxide (ZnOx), or copper oxide (CuO).

[0048] According to one embodiment, the antenna conductive layer 130 may include a stacked structure of a transparent conductive oxide layer and a metal layer. For example, it may have a bilayer structure of a transparent conductive oxide layer - metal layer or a trilayer structure of a transparent conductive oxide layer - metal layer - transparent conductive oxide layer. In this case, the resistance can be reduced by the metal layer to increase the signal transmission speed and improve flexibility at the same time, and the corrosion resistance and transparency can be improved by the transparent conductive oxide layer.

[0049] The lower ground layer 140 may be disposed on the lower side portion of the display panel 110. The lower ground layer 140 may form a ground composite structure with the display panel 110. This ground composite structure may be used as a single ground layer to improve the performance (grounding performance) of the ground layer.

[0050] For example, when the grounding performance of the display panel 110 is insufficient, specifically when the radiation efficiency is insufficient due to the electrical loss caused by the high resistance of the display panel 110, the lower ground layer 140 may supplement and increase the radiation efficiency to improve the grounding performance of the entire ground composite structure. Thereby, the gain and efficiency of the antenna can be improved.

[0051] The lower ground layer 140 may include a metal, a metal alloy, or a metal oxide having a lower resistance than the display panel 110. Therefore, when forming a ground composite structure with the display panel 110, the grounding performance of the display panel 110 can be effectively improved.

[0052] According to one embodiment, the lower ground layer 140 may at least partially overlap with the antenna conductive layer 130 (more specifically, Figure 3 the radiator 310) in the thickness direction of the antenna stack 100. Therefore, the lower ground layer 140 may be provided as a grounding portion of the antenna conductive layer 130. For example, the antenna conductive layer 130 and the lower ground layer 140 may be coupled to each other to transmit and receive antenna signals. Due to this overlapping structure, the grounding performance generated by the lower ground layer 140 can be improved.

[0053] According to one embodiment, the lower ground layer 140 may completely overlap with the antenna conductive layer 130 (more specifically, Figure 3 the radiator 310). In this case, the coupling area between the lower ground layer 140 and the antenna conductive layer 130 can be increased, thereby increasing the gain and efficiency of the antenna.

[0054] According to one embodiment, the resistance of the lower ground layer 140 may be 0.5 Ω / sq or less. When the grounding performance of the display panel 110 is insufficient, in order to help improve the antenna performance (such as the antenna gain characteristic) through the lower ground layer 140 as a ground composite structure, the lower ground layer 140 should have a resistance that satisfies at least 0.5 Ω / sq or less.

[0055] According to one embodiment, the lower ground layer 140 may be provided as a functional layer of a display device on which the antenna stack 100 is mounted. In other words, the functional layer of the display device may serve as the lower ground layer 140. Here, the functional layer is adapted to implement intelligent functions and may include, according to the functions, a transparent electrode, a full metal, a patterned metal, etc. The functional layer may be, for example, a stainless steel (SUS) plate, a heat sink, a digital converter, an electromagnetic shielding layer, a pressure sensor, a fingerprint sensor, etc., and is preferably a heat sink. The heat sink is a heat dissipation device provided in the form of a sheet for dissipating heat generated by the display device to the outside, and may be formed of a heat-conductive metal plate or the like.

[0056] Figure 2 is a schematic cross-sectional view showing a display panel according to one embodiment.

[0057] Referring to Figure 2 , the display panel 110 may include an electrode structure 210 and a packaging layer 220.

[0058] The electrode structure 210 may include a gate electrode, a source electrode, and a drain electrode included in a thin film transistor (TFT) array of the display panel. In addition, the electrode structure 210 may include a pixel electrode of the display panel.

[0059] For example, the gate electrode, the source electrode, the drain electrode, and the pixel electrode may include a low-resistance metal such as 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 thereof. They may be used alone or in combination of two or more.

[0060] According to one embodiment, the electrode structure 210 may include a transparent conductive oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), zinc oxide (ZnOx), or copper oxide (CuO).

[0061] According to one embodiment, the electrode structure 210 may include a stacked structure of a transparent conductive oxide layer and a metal layer. For example, it may have a bilayer structure of a transparent conductive oxide layer - metal layer or a trilayer structure of a transparent conductive oxide layer - metal layer - transparent conductive oxide layer. In this case, the resistance can be reduced by the metal layer to increase the signal transmission speed and at the same time improve flexibility, and the corrosion resistance and transparency can be improved by the transparent conductive oxide layer.

[0062] The encapsulation layer 220 may include an inorganic insulating material, an organic insulating material, or an organic-inorganic hybrid film. The encapsulation layer 220 may be provided as a sealing layer for protecting thin film transistors (TFTs), electrodes, and a display layer included in the display panel. According to one embodiment, the encapsulation layer 220 may be manufactured together as a component or member included in the display panel.

[0063] According to one embodiment, the electrode structure 210 may be provided to form a ground layer of a ground composite structure together with the lower ground layer 140.

[0064] According to one embodiment, the encapsulation layer 220 may be provided as the dielectric layer 120. In this case, the antenna conductive layer 130 may be provided on the encapsulation layer 220 without separately forming a separate dielectric layer. Additionally, by forming a separate dielectric layer and providing the antenna conductive layer 130 on the separate dielectric layer, the separate dielectric layer and the encapsulation layer 220 may be used as one dielectric layer 120.

[0065] Figure 3 is a schematic plan view showing an antenna conductive layer according to one embodiment.

[0066] Referring to Figure 3 , the antenna conductive layer 130 may include a radiator 310, a transmission line 320, and a pad electrode 330.

[0067] The radiator 310 may be formed in a mesh structure. For example, the radiator 310 may be formed in a mesh structure having an opening ratio or light transmittance of 70% or more. Thereby, the light transmittance of the radiator 310 may be increased, and the flexibility of the antenna stack 100 may be improved. Accordingly, the antenna stack 100 may be effectively applied to a flexible display device.

[0068] According to one embodiment, as Figure 3 shown, the radiator 310 may be implemented in a rectangular shape. However, this is merely an example, and there is no particular limitation on the shape of the radiator 310. That is, the radiator 310 may be implemented in various shapes such as a rhombus, a circle, etc.

[0069] The radiator 310 may be electrically connected to the transmission line 320 to be powered through the transmission line 320.

[0070] The transmission line 320 may be provided between the radiator 310 and the signal pad 331 of the pad electrode 330 to electrically connect the radiator 310 and the signal pad 331.

[0071] The transmission line 320 may branch from a central portion of the radiator 310 to connect to the signal pad 331.

[0072] According to one embodiment, the transmission line 320 may include a conductive material substantially the same as that of the radiator 310. In addition, the transmission line 320 may be provided as a substantially single member by being integrally connected to the radiator 310, or may be provided as a member separate from the radiator 310.

[0073] The transmission line 320 may be formed as a mesh structure having a shape substantially the same as or similar to that of the radiator 310.

[0074] The pad electrode 330 may include a signal pad 331 and a ground pad 332.

[0075] The signal pad 331 may be connected to an end of the transmission line 320 to be electrically connected to the radiator 310 through the transmission line 320. Thus, the signal pad 331 may electrically connect the driving circuit unit (such as an IC chip, etc.) to the radiator 310. For example, a printed circuit board such as a flexible printed circuit board (FPCB) may be adhered to the signal pad 331, and the driving circuit unit may be mounted on the flexible printed circuit board. Therefore, the radiator 310 and the driving circuit may be electrically connected to each other.

[0076] The ground pad 332 may be disposed around the signal pad 331 so as to be electrically and physically separated from the signal pad 331. For example, a pair of ground pads 332 may be arranged to face each other with the signal pad 331 interposed therebetween.

[0077] According to one embodiment, the signal pad 331 and the ground pad 332 may be formed of a solid structure including the above-mentioned low-resistance metal or its alloy to reduce the signal resistance. In this case, the signal pad 331 and the ground pad 332 may be formed as a multilayer structure including the above-mentioned low-resistance metal or its alloy layer and a transparent conductive oxide layer.

[0078] According to one embodiment, the antenna conductive layer 130 may further include a dummy pattern 340.

[0079] The dummy pattern 340 may be disposed around the radiator 310 and the transmission line 320.

[0080] The dummy pattern 340 is formed as a mesh structure having a shape substantially the same as or similar to that of the radiator 310 and / or the transmission line 320, and may include the same metal as the radiator 310 and / or the transmission line 320. According to one embodiment, the dummy pattern 340 may be formed as a segmented mesh structure.

[0081] The dummy pattern 340 may be set to be electrically and physically separated from the radiator 310 and the transmission line 320. For example, a separation region 341 may be formed along the side lines or edges of the radiator 310 and the transmission line 320 to separate the dummy pattern 340 from the radiator 310 and the transmission line 320.

[0082] As described above, by disposing a dummy pattern 340 having a mesh structure substantially the same as or similar to the radiator 310 and / or the transmission line 320 around the radiator 310 and the transmission line 320, the radiator 310 and the transmission line 320 can be prevented from being seen by a user of the display device on which the antenna stack is mounted.

[0083] In addition, for ease of description, only one antenna conductor (radiator 310 and transmission line 320) is shown in Figure 3 , but a plurality of antenna conductors may be disposed in an array on the dielectric layer 120.

[0084] Figure 4 is a schematic cross-sectional view showing an antenna stack according to another embodiment.

[0085] Referring to Figure 4 , an antenna stack 400 according to another embodiment may include a display panel 110, a dielectric layer 120, an antenna conductive layer 130, a lower ground layer 140, and a lower dielectric layer 410. Here, the display panel 110, the dielectric layer 120, the antenna conductive layer 130, and the lower ground layer 140 are the same as the antenna stack described above with reference to Figures 1 to 3 and thus will not be described in detail.

[0086] The lower dielectric layer 410 may be disposed between the display panel 110 and the lower ground layer 140. For example, the lower dielectric layer 410 may be in contact with the display panel 110 and the lower ground layer 140, and another member may be inserted between the lower dielectric layer 410 and the display panel 110 and / or between the lower dielectric layer 410 and the lower ground layer 140.

[0087] The lower dielectric layer 410 may include an insulating material having a predetermined dielectric constant. According to one embodiment, the lower dielectric layer 410 may include an inorganic insulating material such as glass, silicon oxide, silicon nitride, or metal oxide, or an organic insulating material such as epoxy resin, acrylic resin, or imide resin.

[0088] According to one embodiment, the transparent film may be provided as the lower dielectric layer 410. In this case, the transparent film may include: polyester resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, etc.; cellulose resins such as diacetyl cellulose, triacetyl cellulose, etc.; polycarbonate resins; acrylic resins such as poly(methyl)methacrylate, poly(methyl)ethyl acrylate, etc.; styrene resins such as polystyrene, acrylonitrile-styrene copolymer, etc.; polyolefin resins such as polyethylene, polypropylene, cyclic polyolefin or polyolefin having a norbornene structure, ethylene-propylene copolymer, etc.; vinyl chloride resins; amide resins such as nylon, aromatic polyamide; imide resins; polyether sulfonic acid resins; sulfonic acid resins; polyether ether ketone resins; polyphenylene sulfide resins; vinyl alcohol resins; vinylidene chloride resins; vinyl butyral resins; allylated resins; polyoxymethylene resins; thermoplastic resins such as epoxy resins, etc. These compounds may be used alone or in combination of two or more. In addition, a transparent film made of a thermosetting resin such as (meth)acrylate, urethane, acrylic urethane, epoxy resin, silicone, etc. or an ultraviolet curable resin may be used as the lower dielectric layer 410.

[0089] According to one embodiment, an adhesive film such as an optically clear adhesive (OCA) or an optically clear resin (OCR) may also be included in the lower dielectric layer 410.

[0090] According to one embodiment, the lower dielectric layer 410 may be formed as a substantially single layer, or may be formed as a multilayer structure of two or more layers.

[0091] A capacitance or an inductance may be formed between the display panel 110 and / or the lower ground layer 140 through the lower dielectric layer 410, thereby forming a ground composite structure that can be formed. The frequency band that can be driven or induced by the antenna stack 400 may be adjusted through the lower dielectric layer 410. When the dielectric constant of the lower dielectric layer 410 exceeds about 12, the driving frequency is excessively reduced, so that the antenna driving in the desired high frequency band may not be achieved. Therefore, according to one embodiment, the dielectric constant of the lower dielectric layer 410 may be adjusted to a range of about 1.5 to 12, preferably about 2 to 7.

[0092] According to one embodiment, the thickness of the lower dielectric layer 410 may be determined such that the distance between the electrode structure 210 of the display panel 110 and the lower ground layer 140 is 50 μm to 800 μm. When the distance between the electrode structure 210 and the lower ground layer 140 exceeds 800 μm, even when the resistance of the lower ground layer 140 is low, the effect of improving the grounding performance due to the formation of the above-described ground composite structure may be substantially unachievable. Preferably, the distance between the electrode structure 210 and the lower ground layer 140 is 50 μm to 500 μm, and more preferably 50 μm to 300 μm. For example, the thickness of the lower dielectric layer 410 may be 50 μm to 800 μm, preferably 50 μm to 500 μm, and more preferably 50 μm to 300 μm.

[0093] Figure 5 FIG. is a schematic cross-sectional view showing an antenna stack according to another embodiment.

[0094] Referring to Figure 5 , the antenna stack 500 according to another embodiment may include a display panel 110, a dielectric layer 120, an antenna conductive layer 130, a lower ground layer 140, a lower dielectric layer 410, a first adhesive layer 510, and a second adhesive layer 520. Here, the display panel 110, the dielectric layer 120, the antenna conductive layer 130, and the lower ground layer 140 are the same as those of the antenna stack described above with reference to Figures 1 to 3 and the lower dielectric layer 410 is the same as that of the antenna stack described above with reference to Figure 4 , and thus will not be described in detail.

[0095] The first adhesive layer 510 may be disposed between the antenna conductive layer 130 and the dielectric layer 120, and the second adhesive layer 520 may be disposed between the dielectric layer 120 and the display panel 110.

[0096] The first adhesive layer 510 and the second adhesive layer 520 may include an adhesive film such as an optically clear adhesive (OCA), an optically clear resin (OCR), or the like.

[0097] According to one embodiment, the antenna conductive layer 130 and the display panel 110 may be electrically and physically separated from each other through the dielectric layer 120. In addition, the display panel 110 and the lower ground layer 140 may be connected to each other through vias or contacts penetrating the dielectric layer 120.

[0098] According to one embodiment, the display panel 110 and the lower ground layer 140 may be electrically and physically separated from each other through the lower dielectric layer 410. In addition, the display panel 110 and the lower ground layer 140 may be connected to each other through vias or contacts penetrating the lower dielectric layer 410.

[0099] Figure 6 is a schematic plan view showing a display device according to an embodiment. More specifically, Figure 6 is a view showing an external shape of the display device including a window.

[0100] Referring to Figure 6 , the display device 600 may include a display area 610 and a peripheral area 620. The display area 610 may represent an area where visual information is displayed, and the peripheral area 620 may represent an opaque area provided on two sides and / or two ends of the display area 610. For example, the peripheral area 620 may correspond to a light-shielding portion or a border portion of the display device 600.

[0101] According to an embodiment, the above-described antenna stacks 100, 400, and 500 may be mounted on the display device 600. For example, the radiators 310 and transmission lines 320 of the antenna stacks 100, 400, and 500 are provided to at least partially correspond to the display area 610 of the display device 600, and the pad electrodes 330 may be provided to correspond to the peripheral area 620 of the display device 600. In this case, a part of the transmission line 320 may be provided to correspond to the peripheral area 620 of the display device 600.

[0102] A driving circuit such as an IC chip of the display device 600 and / or the antenna stacks 100, 400, and 500 may be provided in the peripheral area 620.

[0103] By providing the pad electrodes 330 of the antenna stacks 100, 400, and 500 close to the driving circuit, signal loss can be suppressed by shortening the path for transmitting and receiving signals.

[0104] When the antenna stacks 100, 400, and 500 include dummy patterns 340, the dummy patterns 340 may be provided to at least partially correspond to the display area 610 of the display device 600.

[0105] The antenna stacks 100, 400, and 500 include radiators 310, transmission lines 320, and / or dummy patterns 340 formed in a mesh structure, so that the pattern can be significantly reduced or prevented from being seen while increasing the light transmittance. Therefore, the image quality in the display area 610 can be improved while maintaining or improving the desired communication reliability.

[0106] According to one embodiment, the lower ground layer 140 of the antenna stacks 100, 400, and 500 can be set as a functional layer for implementing intelligent functions, such as a stainless steel (SUS) plate, a heat sink, a digital converter, an electromagnetic shielding layer, a pressure sensor, a fingerprint sensor, etc. of the display device 600. In other words, the functional layer of the display device 600 can be used as the lower ground layer 140 of the antenna stacks 100, 400, and 500. Therefore, the functional layer of the display device 600 can be used as the lower ground layer 140 of the antenna stacks 100, 400, and 500 without forming a separate lower ground layer, thereby facilitating the mechanical design of the display device 600 or the antenna stacks 100, 400, and 500.

[0107] The present invention has been described with reference to the preferred embodiments, and those skilled in the art will understand that various modifications can be made without departing from the basic features of the present invention. Therefore, it should be understood that the scope of the present invention is not limited to the above embodiments, and various other embodiments within the scope equivalent to the content described in the claims are also included in the present invention.

[0108] Examples 1 to 11

[0109] A 1×4 patch array antenna conductive layer with a mesh pattern made of a copper-calcium (CuCa) alloy is formed on the upper surface of the cycloolefin polymer dielectric layer, and an OLED panel is adhered to the lower surface of the dielectric layer. In this case, the OLED panel includes an electrode structure with a resistance of 10 Ω / sq, which is formed on a polyimide substrate film with a thickness of 50 μm.

[0110] A copper sheet with a resistance of 0.5 Ω / sq is adhered to the lower surface of the OLED panel as the lower ground layer.

[0111] In Example 1, an antenna stack with a lower ground layer directly formed on the polyimide substrate film of the OLED panel is prepared as an example, and in Examples 2 to 11, an antenna stack with a lower dielectric layer (thin film or adhesive) added between the electrode structure of the OLED panel and the lower ground layer to adjust the distance between the electrode structure of the OLED panel and the lower ground layer is prepared as an example.

[0112] Comparative Example

[0113] A 1×4 patch array antenna conductive layer with a mesh pattern made of a copper-calcium (CuCa) alloy is formed on the upper surface of the cycloolefin polymer dielectric layer, and an OLED panel is adhered to the lower surface of the dielectric layer.

[0114] Test Example - Evaluation of Antenna Characteristics According to the Distance between the Electrode Structure of the OLED Panel and the Lower Ground Layer

[0115] As a result of measuring the antenna gain of the antenna laminates prepared in Examples 1-11 and Comparative Examples at the target frequency of 28.0 GHz, the results listed in Table 1 below were obtained.

[0116] [Table 1]

[0117]

[0118] Referring to Table 1, as a result of measuring the antenna gain at the target frequency of 28.0 GHz, it was confirmed that, unlike the antenna laminates prepared in the Comparative Examples that do not include a lower ground layer on the lower side of the electrode structure of the OLED panel, the antenna laminates prepared in Examples 1-11, which include a lower ground layer having a low resistance, exhibited excellent antenna gain characteristics. In particular, it was confirmed that the antenna laminates prepared in Examples 1-10, having a thickness of 800 μm or less, exhibited an antenna gain satisfying 6 dBi or more.

Claims

1. An antenna stack, characterized in that, It includes: A display panel including an electrode structure; A dielectric layer disposed on the display panel; An antenna conductive layer disposed on the dielectric layer; And A lower ground layer disposed on the lower side portion of the display panel and having a lower resistance than the display panel, wherein the distance between the electrode structure and the lower ground layer is 50 μm to 800 μm, and the lower ground layer is one of a SUS board, a heat sink, a digital converter, an electromagnetic shielding layer, and a fingerprint sensor of a display device on which the antenna stack is mounted.

2. The antenna stack according to claim 1, wherein It further includes: A lower dielectric layer disposed between the display panel and the lower ground layer.

3. The antenna stack according to claim 2, wherein The thickness of the lower dielectric layer is 50 μm to 800 μm.

4. The antenna stack according to claim 1, wherein The resistance of the display panel is 10 Ω / sq or less.

5. The antenna stack according to claim 1, characterized in that, The resistance of the lower ground layer is 0.5 Ω / sq or less.

6. The antenna stack according to claim 1, wherein It further includes: A first adhesive layer disposed between the antenna conductive layer and the dielectric layer; and A second adhesive layer disposed between the dielectric layer and the display panel.

7. The antenna stack according to claim 1, wherein The antenna conductive layer includes a radiator and a transmission line connected to the radiator, and the lower ground layer overlaps at least partially with the radiator.

8. A display device, characterized in that, It includes the antenna stack according to claim 1.

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