A nano-twin copper patch antenna and a preparation method thereof

Abstract

The application discloses a nano-twin copper patch antenna and a preparation method thereof, relates to the field of micro electro mechanical devices, and comprises a nano-twin copper antenna, a dielectric substrate and a protective layer covering the nano-twin copper antenna, wherein the thickness of the nano-twin copper antenna is 0.1-200 mu m, and the organizational structure of the nano-twin copper antenna comprises a nano-twin structure. The nano-twin copper patch antenna with the nano-twin structure is prepared, and the conductivity, radio frequency performance and mechanical performance of the nano-twin copper patch antenna are improved.

Description

Technical Field

[0001] This application relates to the field of microelectromechanical devices (MEMS) technology, and in particular to a nanotwinned copper patch antenna and its fabrication method. Background Technology

[0002] The world today is one of rapid information technology development, with the booming development of technologies such as 5G and the Internet of Things (IoT). Mobile communication devices are increasingly evolving towards wearable and portable designs, placing higher demands on flexible, ultra-thin, and highly integrated wireless communication components. Fields such as life and health monitoring and portable RFID tags already have an extremely strong demand for flexible, ultra-thin wireless communication components. How to manufacture wireless communication components that meet the requirements of flexibility and ultra-thinness while ensuring good radiation performance is a problem with extremely broad research prospects. The field of microstrip patch antennas has already seen in-depth research. Traditional high-performance microstrip patch antennas are designed based on traditional high-conductivity metals (such as copper, silver, gold, and aluminum) and have been widely used in fields such as satellite communication, remote sensing, and mobile devices.

[0003] Microstrip patch antennas with high shape complexity are often manufactured using printing methods due to their intricate structure, resulting in complex processing steps, a large number of equipment, and high manufacturing costs. However, for integrated microstrip RF devices or conformal microstrip antennas with high shape complexity, the application of metallic materials is severely limited by their low flexibility and complex manufacturing processes. To address this issue, current research mainly focuses on modifying the metal morphology to improve mechanical properties, primarily using metal mesh, liquid metal, and metallic ink. However, liquid metal has low conductivity due to its surface oxides, and the additives in metallic ink also result in less than ideal conductivity, reducing the performance of patch antennas manufactured for use. Summary of the Invention

[0004] In view of the shortcomings of the aforementioned related technologies, this application provides a nanotwinned copper patch antenna and its fabrication method. This application improves the conductivity, radio frequency performance, and mechanical properties of the copper patch antenna by fabricating a copper antenna with a nanotwinned structure.

[0005] Firstly, the nanotwinned copper patch antenna provided in this application adopts the following technical solution:

[0006] A nanotwinned copper patch antenna includes a nanotwinned copper antenna, a dielectric substrate, and a protective layer covering the nanotwinned copper antenna. The thickness of the nanotwinned copper antenna is 0.1-200 μm, and the microstructure of the nanotwinned copper antenna includes a nanotwinned structure.

[0007] Preferably, the twin spacing of the nanotwin structure is 10-500 nm.

[0008] Preferably, the dielectric substrate has a dielectric constant of 2-6 and a thickness of 0.5-2 mm.

[0009] Preferably, the dielectric substrate comprises one or more of polyethylene terephthalate, polydimethylsiloxane, and epoxy glass fiber composite material.

[0010] Preferably, considering economic efficiency, practicality, and thermal stability at high frequencies, a 0.5mm thick polytetrafluoroethylene plate (dielectric constant of 2) is used as the dielectric substrate.

[0011] Secondly, the fabrication method of the nanotwinned copper patch antenna provided in this application adopts the following technical solution:

[0012] A method for fabricating a nanotwinned copper patch antenna includes the following steps: placing a nanotwinned copper anode and a cathode plate in an electroplating solution containing sulfuric acid nanotwinned copper; constructing an electrolyte channel between the cathode plate and the anode; applying a pulsed current through the anode and cathode plate and causing the anode to move relative to the cathode plate to perform electrodeposition on the cathode plate to obtain a nanotwinned copper antenna.

[0013] After removing the nanotwinned copper antenna from the cathode plate, cleaning it, and fixing it onto the dielectric substrate, a protective layer covering the antenna is then fixed onto the dielectric substrate to obtain the nanotwinned copper patch antenna.

[0014] Preferably, the electroplating solution comprises copper sulfate, polyethylene glycol, emulsifier, and sodium chloride, wherein the concentration of copper sulfate is 0.1-1M, the concentration of polyethylene glycol is 0.05-0.1g / L, the concentration of emulsifier is 0.05-0.1g / L, and the concentration of sodium chloride is 0-100mg / L.

[0015] Preferably, the electroplating solution further includes a brightener, a leveling agent, and a dispersant, wherein the concentration of the brightener is 0.01-0.1 g / L, the concentration of the leveling agent is 0.01-0.1 g / L, and the concentration of the dispersant is 0.01-0.1 g / L.

[0016] Preferably, the electrolyte further includes an oxidant, which is 27.5-35 wt% hydrogen peroxide, added at an amount of 1-10 mL / L.

[0017] Preferably, the pH of the electroplating solution is not greater than 1.

[0018] Preferably, the voltage of the pulse current is 10-50V, and the current density is 30-200mA / cm². 2 The conduction time is 10-50ms, and the disconnection time is 100-300ms.

[0019] In summary, this application includes at least one of the following beneficial technical effects:

[0020] 1. This application improves the conductivity and mechanical properties of nanotwinned copper patch antennas by fabricating a nanotwinned copper antenna with a nanotwinned structure.

[0021] 2. The nanotwinned copper patch antenna prepared by this application has good frequency response in the 5.25GHz band, signal transmission loss of less than 10dB, and strong anti-interference ability, thus improving the radio frequency performance of the nanotwinned copper patch antenna.

[0022] 3. This application prepares a nanotwinned copper antenna by pulse electrodeposition and fabricates it into a nanotwinned copper patch antenna. This improves the controllability of the nanotwinned copper antenna's microstructure and the microstructure of the nanotwins within the antenna, thereby enhancing the conductivity and mechanical properties of the nanotwinned copper patch antenna. Attached Figure Description

[0023] Figure 1 This is a physical image of the copper antenna of Embodiment 1 of this application;

[0024] Figure 2 This is a physical diagram of the copper antenna of Embodiment 2 of this application;

[0025] Figure 3 This is a transmission electron microscope (TEM) image of the copper antenna of Embodiment 1 of this application;

[0026] Figure 4 The S of the copper patch antenna in Embodiment 2 of this application 11 Performance graph;

[0027] Figure 5 This is a comparison chart of the hardness of the copper antennas in Comparative Example 1 and Example 1 of this application. Detailed Implementation

[0028] The present application will be further described in detail below with reference to the embodiments. The following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified, specific conditions in the following embodiments were performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the methods used are conventional methods known in the art, and the consumables and reagents used are commercially available. Unless otherwise stated, the technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be applied to the present invention.

[0029] The raw materials used in the examples and comparative examples are all commercially available.

[0030] Example 1

[0031] Example 1 of this application provides a nano-twinned copper patch antenna, the preparation method of which is as follows: (1) Prepare a basic electroplating solution with a concentration of 0.5 mol / L of sulfuric acid nano-twinned copper, a concentration of 0.07 g / L of polyethylene glycol, a concentration of 0.07 g / L of emulsifier, a concentration of 50 mg / L of sodium chloride, a concentration of 0.05 g / L of brightener, a concentration of 0.05 g / L of leveling agent, and a concentration of 0.05 g / L of dispersant. Add 30 wt% hydrogen peroxide to the basic electroplating solution at a ratio of 5 ml / L, and adjust the pH to 1 with sulfuric acid to obtain the electroplating solution and add it to the plating tank.

[0032] (2) Using nano-twinned copper metal as the anode and stainless steel plate as the cathode, the anode is installed in a nozzle containing the electroplating solution, and the cathode plate is installed in the plating bath. The flow of the electroplating solution from the nozzle to the plating bath is controlled by the nozzle to create an electrolyte channel between the cathode and anode. A pulsed current is applied through the anode and cathode, with a voltage of 10V and a current density of 200mA / cm². 2 The conduction time is 20ms and the deconduction time is 100ms. The anode moves in a serpentine pattern relative to the cathode plate for electrodeposition, resulting in a 20μm thick, serpentine nanotwinned copper antenna. Figure 1 As shown;

[0033] (3) Remove the nano-twinned copper antenna from the cathode plate, rinse it with alcohol and water, then paste it onto one side of the dielectric substrate and paste the grounding layer on the other side. Cover the nano-twinned copper antenna with polyimide tape and paste it onto the dielectric substrate to form a protective layer, thus obtaining the nano-twinned copper patch antenna. When using the nano-twinned copper patch antenna, connect it to the antenna terminal by means of conductive glue or welding.

[0034] Example 2

[0035] Embodiment 2 of this application provides a nanotwinned copper patch antenna. The difference between Embodiment 2 and Embodiment 1 is that, in the fabrication process of Embodiment 2, the nanotwinned copper antenna is shaped into a star with a thickness of 30 μm. Figure 2 As shown.

[0036] Comparative Example 1

[0037] Comparative Example 1 provides a method for preparing a coarse-grained copper patch antenna, which is as follows: using coarse-grained copper wires, the antenna is prepared by pressing and molding with a mold, and the coarse-grained copper antenna with the same shape and thickness as in Example 1 is prepared.

[0038] Testing and Inspection

[0039] Transmission electron microscopy (TEM) imaging was performed on the copper antenna of Example 1, such as... Figure 3As shown. The S11 performance diagram of the copper patch antenna of Example 2 is as follows. Figure 4 As shown, the horizontal axis represents the signal frequency band, and the vertical axis represents the frequency band loss. The stiffness of the copper antennas in Comparative Example 1 and Example 1 was measured, resulting in a stiffness comparison chart of the copper antennas in Comparative Example 1 and Example 1, as shown below. Figure 5 As shown. Results Analysis

[0040] The following combination Figure 1-5 The experimental results provided provide a detailed explanation of this application.

[0041] Reference Figure 1 and Figure 2 The nanotwinned copper antennas of Examples 1 and 2 have a width of about 500 μm, and the width is uniform, the outline is clear, and the size is accurate. This shows that the preparation of nanotwinned copper patch antennas by electrodeposition using an electroplating solution in this application is beneficial to improving the forming effect and dimensional accuracy of micron-scale nanotwinned copper antennas.

[0042] Reference Figure 3 It is known that the nanotwinned copper patch antenna in Embodiment 1 of this application has a high-density twinned structure with a twin spacing of 50-100 nm. This indicates that the fabrication method of the nanotwinned copper patch antenna in this application can successfully fabricate a nanotwinned copper antenna containing a twinned structure. The hindering effect of twin boundaries on dislocation movement can be regarded as an internal obstacle to dislocation movement. This effect is similar to the strengthening effect of grain boundaries, thereby improving the strength of the material. As a special type of coherent grain boundary, the scattering ability of a grain boundary is one order of magnitude smaller than that of a conventional grain boundary. This means that obtaining a high density of twin boundaries in a metal may effectively improve the strength of the metal while having little impact on its conductivity. In the study of nanotwinned copper, it was found that the increase of twin boundaries can significantly improve the strength and tensile plasticity of the material, while the conductivity remains almost unchanged, comparable to oxygen-free high-conductivity nanotwinned copper. This improves both the mechanical strength and the radio frequency performance of the nanotwinned copper patch antenna.

[0043] Reference Figure 4 It can be seen that the minimum frequency band loss of the nanotwinned copper patch antenna in Embodiment 2 of this application corresponds to the abscissa of 5.25GHz. That is, the nanotwinned copper patch antenna in Embodiment 2 of this application has a good frequency band response in the 5.25GHz band, and the signal transmission loss is less than 10dB. It has the characteristics of narrow response frequency, strong anti-interference ability, small S11 reflection response, and high transmission power.

[0044] Reference Figure 5It can be seen that the hardness of the nanotwinned copper antenna (labeled as twinned copper) in Example 1 increased from 1.25 GPa to 2 GPa compared to the coarse-grained copper antenna (labeled as coarse-grained copper) in Comparative Example 1, indicating that the preparation method used to obtain Example 1 is beneficial to improving the mechanical properties of the nanotwinned copper patch antenna.

[0045] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for fabricating a nanotwinned copper patch antenna, characterized in that: The nanotwinned copper patch antenna comprises a nanotwinned copper antenna, a dielectric substrate, and a protective layer covering the nanotwinned copper antenna. The thickness of the nanotwinned copper antenna is 0.1-200 μm, and the microstructure of the nanotwinned copper antenna comprises a nanotwinned structure. The twin spacing of the nanotwinned structure is 10-500 nm. The dielectric substrate has a dielectric constant of 2-6 and a thickness of 0.5-2 mm. The dielectric substrate includes one or more of polyethylene terephthalate, polydimethylsiloxane, and epoxy fiberglass composite material; the preparation method of the nanotwinned copper patch antenna includes the following steps: placing a copper anode and a cathode plate in an electroplating solution containing copper sulfate, constructing an electrolyte channel between the cathode plate and the anode, applying a pulsed current through the anode and cathode plate and causing the anode to move relative to the cathode plate to perform electrodeposition on the cathode plate to obtain the nanotwinned copper antenna; After removing the nanotwinned copper antenna from the cathode plate, cleaning it, and fixing it onto the dielectric substrate, a protective layer covering the nanotwinned copper antenna is then fixed onto the dielectric substrate to obtain the nanotwinned copper patch antenna.

2. The method for fabricating a nanotwinned copper patch antenna according to claim 1, characterized in that: The electroplating solution includes copper sulfate, polyethylene glycol, emulsifier, and sodium chloride. The concentration of copper sulfate is 0.1-1 mol / L, the concentration of polyethylene glycol is 0.05-0.1 g / L, the concentration of emulsifier is 0.05-0.1 g / L, and the concentration of sodium chloride is 0-100 mg / L.

3. The method for fabricating a nanotwinned copper patch antenna according to claim 2, characterized in that: The electroplating solution also includes a brightener, a leveling agent, and a dispersant, wherein the concentration of the brightener is 0.01-0.1 g / L, the concentration of the leveling agent is 0.01-0.1 g / L, and the concentration of the dispersant is 0.01-0.1 g / L.

4. The method for fabricating a nanotwinned copper patch antenna according to claim 2, characterized in that: The electrolyte also includes an oxidant, which is 27.5-35 wt% hydrogen peroxide, added at a rate of 1-10 mL / L.

5. The method for fabricating a nanotwinned copper patch antenna according to claim 1, characterized in that: The pH of the electroplating solution is not greater than 1.

6. The method for fabricating a nanotwinned copper patch antenna according to claim 1, characterized in that: The voltage of the pulse current is 10-50V, and the current density is 30-200mA / cm². 2 The conduction time is 10-50ms, and the disconnection time is 100-300ms.

7. A nanotwinned copper patch antenna, characterized in that: It is prepared by the method for preparing a nanotwinned copper patch antenna according to any one of claims 1-6.

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