Mobile terminal transparent antenna rear cover and manufacturing method thereof

Abstract

The invention discloses a mobile terminal transparent antenna rear cover and a manufacturing method thereof.The mobile terminal transparent antenna rear cover comprises a transparent cover plate, a transparent antenna film and a feed structure, the transparent antenna film is attached to the inner side face of the transparent cover plate, and the transparent antenna film comprises a transparent base material layer and an antenna circuit layer arranged on the transparent base material layer; the antenna circuit layer comprises an antenna pattern area and a coupling area which are connected; the feed structure is located on the side, away from the transparent cover plate, of the transparent antenna film, and the feed structure is used for conducting non-contact coupling feed on the coupling area. The whole surface of the transparent antenna film is attached to the inner side of the transparent cover plate, so that the antenna circuit layer and the transparent cover plate are integrated, the rear cover does not need to be windowed and punched, the integrity and consistency of the appearance of the rear cover are kept, meanwhile, the extra thickness brought by a traditional feed structure is avoided, and the antenna adapts to the light and thin development trend of the mobile terminal; and the whole structure is few in parts, mature in process and easy for large-scale mass production, and meets the requirements of high-frequency communication performance and lightness, thinness and attractiveness of the terminal.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a transparent antenna back cover for a mobile terminal and its manufacturing method. Background Technology

[0002] With the development of high-frequency communication such as 5G / 6G and Wi-Fi 7, the clearance space left for antennas inside mobile terminals such as mobile phones is getting smaller and smaller. Therefore, some existing mobile terminals choose to make antennas directly on the back cover. However, the methods currently used in the industry either greatly increase the thickness of the back cover, have a complex feed point structure design, or damage the integrity of the back cover's appearance. None of these are ideal solutions. Summary of the Invention

[0003] The technical problem solved by the present invention is to provide a transparent antenna back cover for a mobile terminal that is non-destructive in appearance, thin and simple in structure, as well as a method for manufacturing the transparent antenna back cover for the mobile terminal.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a transparent antenna back cover for a mobile terminal, comprising a transparent cover plate, a transparent antenna film, and a feeding structure. The transparent antenna film is attached to the inner side of the transparent cover plate. The transparent antenna film includes a transparent substrate layer and an antenna circuit layer disposed on the transparent substrate layer. The antenna circuit layer includes an antenna pattern area and a coupling area connected together. The feeding structure is located on the side of the transparent antenna film away from the transparent cover plate. The feeding structure is used to provide contactless coupling feeding to the coupling area.

[0005] To solve the above-mentioned technical problems, the second technical solution adopted by the present invention is: a method for manufacturing a transparent antenna back cover for a mobile terminal, used to manufacture the aforementioned transparent antenna back cover for a mobile terminal, comprising the following steps:

[0006] An antenna circuit layer is fabricated on a transparent substrate layer to obtain a transparent antenna film;

[0007] The entire transparent antenna film is adhered to the inner side of the transparent cover plate;

[0008] A power supply structure is configured to enable contactless power supply between the power supply structure and the coupling region.

[0009] The beneficial effects of this invention are as follows: by attaching the entire transparent antenna film to the inside of the transparent cover, the antenna circuit layer and the transparent cover are integrated, eliminating the need for opening windows, drilling holes, or adding spring pads on the back cover, thus maintaining the integrity and consistency of the back cover's appearance. At the same time, it avoids the extra thickness brought by traditional power supply structures, adapting to the development trend of thinner and lighter mobile terminals. The use of contactless coupling power supply eliminates physical connectors, simplifies the assembly process, reduces the risk of failure due to solder joint cracking or spring fatigue, and significantly improves the overall reliability of the device. The overall structure consists only of a transparent cover, a transparent antenna film, and a power supply structure, with fewer components, mature technology, and easy mass production, taking into account both high-frequency communication performance and the needs of thinner and more aesthetically pleasing terminals. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0011] Figure 1 This is a simplified schematic diagram of the structure of the transparent antenna back cover of the mobile terminal in Embodiment 1;

[0012] Figure 2 This is a rear view of the transparent antenna film in the transparent antenna back cover of the mobile terminal according to Embodiment 1.

[0013] Figure 3 This is a simplified schematic diagram of the feeding structure in the transparent antenna back cover of the mobile terminal in Embodiment 1.

[0014] Explanation of icon numbers:

[0015] 1. Transparent cover;

[0016] 2. Transparent antenna film; 21. Transparent substrate layer; 22. Antenna circuit layer;

[0017] 3. Power supply structure. Detailed Implementation

[0018] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indicators such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of the present invention involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0022] Furthermore, if the meaning of "and / or" in the entire text is to include three parallel solutions, taking "and A / or B" as an example, it includes solution A, solution B, and a solution that simultaneously satisfies both A and B. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] Example 1

[0025] Please refer to Figures 1 to 3An embodiment of the present invention is as follows: a transparent antenna back cover for a mobile terminal, comprising a transparent cover plate 1, a transparent antenna film 2, and a feeding structure 3. The transparent antenna film 2 is attached to the inner side of the transparent cover plate 1. The transparent antenna film 2 includes a transparent substrate layer 21 and an antenna circuit layer 22 disposed on the transparent substrate layer 21. The antenna circuit layer 22 includes an antenna pattern area and a coupling area connected together. The feeding structure 3 is located on the side of the transparent antenna film 2 away from the transparent cover plate 1. The feeding structure 3 is used to provide contactless coupling feeding to the coupling area.

[0026] The thickness of the transparent antenna film 2 is 1 to 100 μm, which ensures both conductivity and mechanical strength, while avoiding excessive thickness that would reduce light transmittance or increase the overall assembly space. This ensures that the antenna circuit layer 22 is "invisible" and does not impose any burden on the thinning of the mobile terminal.

[0027] The transparent antenna film 2 is bonded to the transparent cover plate 1 with optically clear adhesive (OCA). The use of optical adhesive for full-surface bonding allows for bubble-free bonding in one step, eliminating the need for mechanical fasteners. This simplifies assembly, provides good sealing, and further enhances the appearance integrity and waterproof reliability of the back cover.

[0028] The antenna circuit layer 22 is located on the side of the transparent substrate layer 21 that is close to the transparent cover plate 1.

[0029] The coupling distance between the feeding structure 3 and the coupling area is 0.01mm-0.50mm, balancing structural tolerances and electromagnetic coupling efficiency. This avoids short-circuit hazards caused by excessive proximity and feed attenuation caused by excessive distance, ensuring consistency in mass production. In actual products, the feeding structure 3 can be located on the side of the transparent substrate layer 21 away from the antenna circuit layer 22 to achieve physical connection with the transparent substrate layer 21. This allows the thickness of the transparent substrate layer 21 itself to form the coupling distance, thereby enabling the transparent antenna back cover of the mobile terminal to form an integral modular structure for easy manufacturing.

[0030] The antenna circuit layer 22 is an ITO film, silver nanowires, or a metal mesh. ITO film, silver nanowires, and metal mesh are all mature high-transmittance conductive materials that can achieve low sheet resistance without affecting visible light transmittance, thus balancing antenna efficiency and transparent appearance.

[0031] The power supply structure 3 can be a microstrip line, a coplanar waveguide, or a slot coupling structure. The microstrip line, coplanar waveguide, or slot coupling structure can be directly fabricated on the motherboard of the mobile terminal for electrical connection with the motherboard, simplifying board layout.

[0032] The transparent cover plate 1 can be made of glass, fiberglass board, plastic board, or transparent ceramic. The use of glass, fiberglass board, plastic board, and transparent ceramic can meet the different requirements of mobile terminals in terms of appearance, strength, and cost, making the same antenna solution applicable to various scenarios such as mobile phones, AR glasses, and automotive displays. The glass can be tempered glass, microcrystalline glass, etc.

[0033] The transparent substrate layer 21 is made of PET (polyethylene terephthalate) or COP (cyclic olefin polymer). PET or COP substrates are resistant to high temperature and bending and have excellent optical properties. They are compatible with the OCA hot-pressing process, ensuring that the substrate does not delaminate or yellow under high temperature and high humidity conditions, thus improving long-term reliability.

[0034] A method for manufacturing a transparent antenna back cover for a mobile terminal, comprising the following steps:

[0035] An antenna circuit layer 22 is fabricated on a transparent substrate layer 21 to obtain a transparent antenna film 2. Specifically, the antenna circuit layer 22 is fabricated by one or more of the following methods: laser etching, printing, nanoimprinting, photolithography, spraying, and spin coating.

[0036] The transparent antenna film 2 is adhered to the inner side of the transparent cover plate 1. In one or more embodiments, the transparent antenna film 2 is bonded to the transparent cover plate 1 by OCA.

[0037] A power supply structure 3 is provided so that the power supply structure 3 and the coupling area are coupled without contact, with a coupling distance of 0.01-0.5mm.

[0038] In one or more embodiments, the power supply structure 3 is welded or hot-pressed to the motherboard of the mobile terminal to complete the assembly of the mobile terminal.

[0039] Based on the content of this embodiment, the applicant produced a sample. In the sample, the transparent cover is made of 0.3mm fiberglass board, the transparent antenna film uses 25um PET as the transparent substrate layer, the antenna circuit layer is a metal mesh with a sheet resistance of 0.5Ω / sq and a thickness of 2um, and the antenna pattern is formed by photolithography. The operating frequency band covers 2.4-2.48GHz and 5.15-5.9GHz. The optical adhesive (OCA) is 25μm thick, and the refractive index is matched to 1.49 to ensure an overall light transmittance of ≥90%. The feeding structure uses a 50Ω microstrip line with a linewidth of 0.2mm, and the coupling distance between the line and the antenna circuit layer is d=0.1mm. It is electrically connected to the motherboard of the mobile terminal through thermoforming. Antenna efficiency tests were performed on the sample. The antenna efficiency of the comparison product without a transparent cover was 46.71%, while the antenna efficiency of the sample was 44.98%, indicating that the transparent antenna cover of this mobile terminal has little impact on antenna efficiency.

[0040] The above are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A transparent antenna back cover for a mobile terminal, characterized in that, include Transparent cover; A transparent antenna film is attached to the inner side of the transparent cover plate. The transparent antenna film includes a transparent substrate layer and an antenna circuit layer disposed on the transparent substrate layer. The antenna circuit layer includes an antenna pattern area and a coupling area connected together. A feeding structure is located on the side of the transparent antenna film away from the transparent cover plate, and the feeding structure is used to provide contactless coupling feeding to the coupling region.

2. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The thickness of the transparent antenna film is 1–100 μm.

3. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The transparent antenna film is bonded to the transparent cover plate with optical adhesive.

4. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The antenna circuit layer is located on the side of the transparent substrate layer closest to the transparent cover plate.

5. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The coupling distance between the power supply structure and the coupling region is 0.01mm-0.50mm.

6. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The antenna circuit layer is an ITO film, silver nanowires, or a metal mesh.

7. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The feeding structure is a microstrip line, a coplanar waveguide, or a slot coupling structure.

8. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The transparent cover is made of glass, fiberglass board, plastic board, or transparent ceramic.

9. The transparent antenna back cover for a mobile terminal according to claim 1, characterized in that, The transparent substrate layer is made of PET or COP.

10. A method for manufacturing a transparent antenna back cover for a mobile terminal, characterized in that, The method for manufacturing a transparent antenna back cover for a mobile terminal according to any one of claims 1-9 comprises the following steps: An antenna circuit layer is fabricated on a transparent substrate layer to obtain a transparent antenna film; The entire transparent antenna film is adhered to the inner side of the transparent cover plate; A power supply structure is configured to enable contactless power supply between the power supply structure and the coupling region.

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