Preparation method of metal conductive adhesive copper-plated antenna and copper-plated antenna

Abstract

The invention provides a preparation method of a metal conductive adhesive copper-plated antenna and a copper-plated antenna, and the preparation method of the metal conductive adhesive copper-plated antenna comprises the following steps: sequentially adding metal powder and a dispersant into an epoxy resin adhesive, and uniformly mixing to obtain a metal conductive adhesive; performing injection molding to obtain a plastic carrier; coating a metal conductive adhesive on the surface of a plastic carrier through a dispensing machine to obtain a preset circuit adhesive layer; curing the preset circuit adhesive layer to form a cured circuit layer; carrying out fine grinding on the cured circuit layer to form a transition metal glue layer; and carrying out chemical copper plating on the cured transition metal glue layer to form an antenna circuit, and obtaining the copper-plated antenna. After the metal conductive adhesive is cured, chemical copper plating is performed to form the antenna circuit, so that the preparation is simple, the cost is relatively low, the formed antenna circuit is tightly combined with the plastic carrier, the thickness of the cured circuit layer can be controlled, the surface of the antenna circuit formed after chemical copper plating is smooth, and the conductive effect of a conductive path is relatively good.

Description

Technical Field

[0001] The present disclosure relates to the technical field of antenna manufacturing, and particularly to a method for manufacturing a copper-plated antenna with a metal conductive adhesive and a copper-plated antenna. Background Art

[0002] Antenna manufacturing is a complex and delicate process, and LDS (Laser Direct Structuring) and PDS (Printed Direct Structuring) are two common antenna manufacturing processes.

[0003] The LDS process for manufacturing an antenna irradiates with a laser to release metal particles from an organometallic complex, thereby forming a circuit interconnection structure on the plastic surface. The LDS material is a modified plastic containing an organometallic complex. After being irradiated with a laser, the organometallic complex releases metal ions to form a conductive circuit. The LDS process requires the selection of modified plastics, which is costly, and the selection and performance of the LDS material have a great influence on the process effect.

[0004] The PDS process is to print a circuit with a conductive silver paste, and after the conductive silver paste is cured, an antenna with a circuit interconnection structure is formed. Resin and silver powder are added to the conductive silver paste, and the amount of silver powder used is large, making its cost high. After the conductive silver paste is cured, shrinkage occurs, making the antenna circuit formed by the conductive silver paste uneven and with low precision. The resin in the conductive silver paste also affects the conductivity of the silver powder in the conductive silver paste to form a conductive path.

[0005] For example, a highly conductive silver paste and its preparation method disclosed in the comparative document CN201610096137.0. The highly conductive silver paste includes metallic silver powder, and the metallic silver powder is a mixture of micron-sized flaky silver powder, submicron-sized spherical silver powder, and nanometer-sized silver powder. This solution uses silver powders with different particle sizes and morphological structures in combination, so that the silver powder forms a denser state in structure. Through the blending with a polymer resin, a solvent, additives, and auxiliaries, the slurry has good printing suitability and good adhesion performance, and can be applied to fields such as printing conductive circuits and RFID tag antennas. However, for the highly conductive silver paste in this solution to directly manufacture an antenna, the amount of silver powder used is large, the cost is high, and the content of the polymer resin easily affects the conductivity of the conductive path for manufacturing the antenna. Summary of the Invention

[0006] The purpose of the present disclosure is to overcome the deficiencies in the prior art, and to provide a preparation method for a copper-plated antenna with a metal conductive adhesive and a copper-plated antenna, which has simple preparation, low cost, high bonding strength, and good conductive effect of the conductive path.

[0007] The purpose of the present disclosure is achieved through the following technical solutions:

[0008] A preparation method for a copper-plated antenna with a metal conductive adhesive includes the following steps:

[0009] Add metal powder and dispersant to epoxy resin glue in sequence and mix evenly to obtain metal conductive glue;

[0010] Obtain a plastic carrier by injection molding;

[0011] Coat the surface of the plastic carrier with the metal conductive glue by a dispensing machine to obtain a preset circuit glue layer;

[0012] Cure the preset circuit glue layer so that a cured circuit layer is formed on the surface of the plastic carrier;

[0013] Finely grind the cured circuit layer so that the surface of the cured circuit layer is flat to form a transition metal glue layer;

[0014] Chemically copper-plate the cured transition metal glue layer to form an antenna circuit with a copper-plated layer and obtain a copper-plated antenna.

[0015] In one embodiment, adding metal powder and dispersant to epoxy resin glue in sequence and mixing evenly to obtain metal conductive glue further includes the following steps:

[0016] Crush the metal powder;

[0017] Screen the crushed metal powder.

[0018] In one embodiment, the particle size of the metal powder is 1μm - 5μm.

[0019] In one embodiment, the thickness of the transition metal glue layer is 15μm - 40μm.

[0020] In one embodiment, the metal powder includes at least one of copper powder and silver powder.

[0021] In one embodiment, the metal conductive glue includes the following mass components:

[0022]

[0023] In one embodiment, the epoxy resin glue is a photo-thermal dual-curing glue.

[0024] In one embodiment, curing the preset circuit glue layer so that a cured circuit layer is formed on the surface of the plastic carrier includes the following steps:

[0025] Photo-cure the preset circuit glue layer on the surface of the plastic carrier by a UV lamp;

[0026] Thermally cure the photo-cured preset circuit glue layer so that a cured circuit layer is formed on the surface of the plastic carrier.

[0027] In one embodiment, after the cured circuit layer is finely ground to make the surface of the cured circuit layer flat to form a transition metal glue layer, and before electroless copper plating on the cured transition metal glue layer, the following steps are further included:

[0028] The surface of the finely ground cured circuit layer is purged.

[0029] A copper-plated antenna is prepared by using the preparation method of the metal conductive glue copper-plated antenna in any one of the above embodiments. The copper-plated antenna includes a plastic carrier and an antenna circuit. The antenna circuit includes a copper-plated layer and a transition metal glue layer. The transition metal glue layer covers the surface of the plastic carrier, and the copper-plated layer covers the surface of the transition metal glue layer. The transition metal glue layer includes cured epoxy resin glue and metal powder, and the metal powder is uniformly distributed in the cured epoxy resin glue.

[0030] Compared with the prior art, the present disclosure has at least the following advantages:

[0031] In the above preparation method of the metal conductive glue copper-plated antenna, the metal conductive glue is pre-coated on the surface of the plastic carrier, and then electroless copper plating is carried out to form an antenna circuit with a copper-plated layer, so that the usage amount of the metal conductive glue is less and the operation is simple, thereby reducing the cost of preparing the copper-plated antenna; by combining the metal conductive glue with the plastic carrier, the antenna circuit formed by electroless copper plating of the metal conductive glue is tightly combined with the plastic carrier, improving the structural strength of the antenna circuit and the plastic carrier; the cured metal conductive glue forms a cured circuit layer, and the thickness of the cured circuit layer can be controlled by fine grinding, so that the surface of the copper-plated layer of the antenna circuit formed after electroless copper plating is flat and the conductive effect of the conductive path of the copper-plated layer is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is a flowchart of the steps of the preparation method of the metal conductive glue copper-plated antenna in one embodiment;

[0034] Figure 2 It is a partial structural schematic diagram of the copper-plated antenna in one embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To facilitate the understanding of the present disclosure, the present disclosure will be described more comprehensively below with reference to the relevant accompanying drawings. Preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present disclosure can be understood more thoroughly and comprehensively.

[0036] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present disclosure belongs. The terms used in the description of the present disclosure herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0038] To better understand the technical solutions and beneficial effects of the present disclosure, the following further describes the present disclosure in detail with specific embodiments:

[0039] Please refer to Figure 1 , which is a preparation method of a copper-plated antenna with metal conductive glue according to an embodiment of the present invention, and includes the following steps: sequentially adding metal powder and a dispersant into epoxy resin glue and mixing evenly to obtain metal conductive glue; injection molding to obtain a plastic carrier; coating the metal conductive glue on the surface of the plastic carrier through a dispensing machine to obtain a preset circuit glue layer; curing the preset circuit glue layer so that a cured circuit layer is formed on the surface of the plastic carrier; finely grinding the cured circuit layer so that the surface of the cured circuit layer is flat to form a transition metal glue layer; chemically plating copper on the cured transition metal glue layer to form an antenna circuit and obtain a copper-plated antenna.

[0040] In one of the embodiments, the preparation method of the copper-plated antenna with metal conductive glue includes the following steps:

[0041] S101 Add metal powder and a dispersant to the epoxy resin glue in sequence and mix them evenly to obtain a metal conductive glue. In this embodiment, a low-ammonia-value high-molecular-weight dispersant is used as the dispersant. The low-ammonia-value high-molecular-weight dispersant has a relatively high molecular weight, which can provide a stronger steric hindrance effect, thereby effectively preventing the agglomeration of metal powder particles, enabling the metal powder to be evenly dispersed in the epoxy resin glue within the metal conductive glue. The metal powder has good electrical conductivity. After the metal powder is mixed with the epoxy resin glue, the metal conductive glue has good electrical conductivity.

[0042] S103 Injection mold to obtain a plastic carrier. In this embodiment, the plastic carrier is used to arrange antenna circuits and can be formed by injection molding of a thermoplastic polymer. A three-dimensional plastic carrier can be obtained through injection molding.

[0043] S105 Coat the metal conductive glue on the surface of the plastic carrier through a dispensing machine to obtain a preset circuit glue layer. In this embodiment, the metal conductive glue can be coated on the surface of the plastic carrier through a dispensing machine. The dispensing machine can control the extrusion amount, coating speed, and the distribution position of the metal conductive glue. That is, the dispensing machine coats the metal conductive glue on the surface of the plastic carrier according to a preset circuit pattern. The dispensing machine adjusts the air pressure and mechanical movement speed to control the glue coating amount and the edge, so that the metal conductive glue is evenly coated on the surface of the plastic carrier, thereby obtaining a relatively thin preset circuit glue layer.

[0044] S107 Cure the preset circuit glue layer to form a cured circuit layer on the surface of the plastic carrier. In this embodiment, after the preset circuit glue layer is cured, the connection strength between the metal powder and the epoxy resin glue is improved, and the epoxy resin glue shrinks, reducing the distance between the metal powder particles to form a conductive path.

[0045] S109 Finely grind the cured circuit layer to make the surface of the cured circuit layer flat to form a transition metal glue layer. In this embodiment, after the epoxy resin glue is cured, it shrinks, making the surface of the cured circuit layer uneven, and the thickness of the cured circuit layer is uneven, resulting in a relatively rough antenna circuit formed by electroless copper plating. By finely grinding the cured circuit layer, the thickness of the transition metal glue layer can be precisely controlled. The surface of the cured circuit layer after fine grinding is smoother. After the cured circuit layer is finely ground, the polymer covering the surface of the metal powder in the cured circuit layer is damaged, causing some metal powder to be further exposed from the cured circuit layer, making the effect of the metal powder as an activation center better, which is conducive to the deposition of elemental copper in electroless copper plating, and further conducive to the formation of a flat copper layer in subsequent copper plating. During fine grinding, a high-precision grinder or a numerical control grinding machine and other equipment can be used to perform high-precision grinding on the cured circuit layer.

[0046] S111: chemically copper-plating the finely ground solidified circuit layer to form an antenna circuit and obtain a copper-plated antenna. In this embodiment, when chemically copper-plating, the plastic carrier with the transition metal glue layer is placed in a chemical copper-plating solution for chemical copper-plating, and the copper-plated antenna obtained after copper-plating is rinsed and dried. When the solidified circuit layer is copper-plated, the finely ground metal powder is exposed on the surface of the solidified circuit layer, so that the metal powder can be used as an activation target center, so that when copper-plating, the copper layer grows and forms smoothly on the surface of the solidified circuit layer, thereby obtaining an antenna circuit with a good conduction effect of the copper-plated layer.

[0047] The above-mentioned method for preparing the metal conductive glue copper-plated antenna is to pre-coat the metal conductive glue on the surface of the plastic carrier, and then perform chemical copper plating to form an antenna circuit with a copper-plated layer, so that the amount of metal conductive glue used is small and the operation is simple, thereby making the cost of preparing the copper-plated antenna low; by combining the metal conductive glue with the plastic carrier, the antenna circuit formed by chemical copper plating of the metal conductive glue is tightly combined with the plastic carrier, thereby improving the structural strength of the antenna circuit and the plastic carrier; after the metal conductive glue is solidified, a solidified circuit layer is formed, and the thickness of the solidified circuit layer can be controlled by fine grinding, so that the surface of the copper-plated layer of the antenna circuit formed after chemical copper plating is smooth and the conductive path of the copper-plated layer has a good conductive effect.

[0048] In one embodiment, the metal powder is added into the epoxy resin glue and mixed evenly to obtain the metal conductive glue, which further includes the following steps:

[0049] Ball milling the metal powder;

[0050] The crushed metal powder is screened. In this embodiment, the uniformity of the metal powder affects the conductive properties of the solidified layer. The metal powder is ball-milled to reduce its particle size. The crushed metal powder is screened to obtain metal powder with uniform particles, thereby maintaining the conductive properties of the metal conductive adhesive after the metal powder is mixed with the light-heat dual-curing adhesive, and making the deposition of the copper element more uniform during copper plating.

[0051] In one embodiment, the particle size of the metal powder is 1 μm-5 μm. In this embodiment, when the particle size of the metal powder is greater than 5 μm, after the metal powder is added to the epoxy resin glue and mixed, the metal powder is spaced far apart after the epoxy resin glue is cured, which affects the conductive properties of the metal conductive glue, thereby making the copper layer formed by the copper plating of the cured circuit layer rougher, thereby affecting the flatness of the antenna circuit surface; when the particle size of the metal powder is less than 1 μm, the particle size of the metal powder is difficult to control, so that the metal powders of different particle sizes are evenly mixed with the epoxy resin glue, thereby affecting the distribution uniformity of the metal powder in the metal conductive glue, and making the copper layer formed by the copper plating of the cured circuit layer unevenly distributed.

[0052] In one embodiment, the cured circuit layer is finely ground to form a transition metal adhesive layer with a thickness of 15μm-40μm. In this embodiment, when the epoxy resin is thick, the cured circuit layer formed by the epoxy resin is prone to cracks, making the cured circuit layer uneven. When the thickness of the cured circuit layer is less than 15μm, the surface of the plastic carrier layer is uneven. During the fine grinding process, the cured circuit layer is easily worn through, resulting in the destruction of the cured circuit layer, and then the formed antenna circuit is incomplete. When the thickness of the cured circuit layer is greater than 40μm, the thickness of the cured circuit layer is relatively thick, so that the formed antenna circuit is thick and occupies more space, which is not conducive to the circuit design of the copper-plated antenna; when the thickness of the transition metal adhesive layer is 15μm-40μm, multiple layers of metal powder can be arranged in the transition metal adhesive layer. When the cured circuit layer is finely ground to different thicknesses, metal powder particles are exposed, forming a thin transition metal adhesive layer with high bonding strength.

[0053] In one embodiment, the metal powder includes at least one of copper powder and silver powder. In this embodiment, both copper powder and silver powder have good electrical conductivity, and copper powder and silver powder are relatively stable, so that the metal conductive adhesive obtained by mixing copper powder or silver powder with the light-heat dual curing adhesive has good electrical conductivity.

[0054] In one embodiment, the metal conductive paste includes the following mass components:

[0055] In this embodiment, when the content of metal powder is less than 20%, after the metal conductive glue is cured, the epoxy resin glue particles separate the metal powder, so that the distance between the metal powders is relatively far. When chemical copper plating is performed, the copper element deposited on the surface of the cured circuit layer is difficult to connect to form an antenna circuit, thereby making the effect of forming the antenna circuit poor; when the metal powder is greater than 40%, the epoxy resin glue is less, and the metal powder is easy to agglomerate to produce large particles, making the surface of the metal conductive glue rougher, and the epoxy resin glue cannot penetrate between the metal powder particles, which reduces the bonding effect of the photothermal dual-curing glue on the metal powder, and the formed cured circuit layer is prone to cracking; the dispersant uses a polymer dispersant, such as a dispersant containing a sulfur group or an amine group. The polymer dispersant forms a steric hindrance on the particle surface through its long chain structure, prevents particle agglomeration and sedimentation, and is compatible with the photothermal dual-curing glue of the epoxy resin glue.

[0056] Further, in one embodiment, after adding metal powder and dispersant into epoxy resin glue in sequence and mixing them, the viscosity of the metal conductive glue is 12000 CPS - 18000 CPS. In this embodiment, when the viscosity of the metal conductive glue is greater than 12000 CPS, the metal conductive glue is not likely to flow when coated on the surface of the plastic carrier, avoiding deformation of the preset circuit glue layer formed on the plastic carrier; when the viscosity of the metal conductive glue is less than 18000 CPS, it is easy for the dot coater to coat the metal conductive glue, and it is easy for the dot coater to control the edge of the preset circuit glue layer formed by coating the metal conductive glue on the surface of the plastic carrier.

[0057] It can be understood that the dispersion state of the metal powder in the metal conductive glue will affect the uniformity of the distribution of the metal powder; in a well-dispersed system, the interaction force between metal powder particles is strong, showing high elastic modulus and low zero-shear viscosity, while in a poorly-dispersed system, due to the agglomeration of metal powder particles, the shear sensitivity is strong, the shear thinning is significant, the thixotropy recovery is slow, and the modulus is low, making the structure easy to be damaged. Therefore, after adding metal powder and dispersant into epoxy resin glue in sequence and mixing them evenly to obtain the metal conductive glue, before injection molding to obtain the plastic carrier, it also includes performing a thixotropy test on the metal conductive glue, including the following steps:

[0058] Test the initial viscosity of the metal conductive glue;

[0059] Perform cyclic shear on the metal conductive glue using a three-stage rate shear of low shear rate, high shear rate, and low shear rate. After 3 - 5 cycles of shear, let it stand for 30 min and then test the viscosity of the metal conductive glue;

[0060] If the recovery rate of the viscosity of the metal conductive glue compared with the initial viscosity is less than 90%, add 0.5% - 1% dispersant and continue to mix for 10 min - 20 min.

[0061] If the recovery rate of the viscosity of the metal conductive glue compared with the initial viscosity is greater than 90%, a qualified metal conductive glue is obtained. In this embodiment, the initial viscosity of the metal conductive glue is 12000 CPS - 18000 CPS, the low shear rate is 6 r / min, the high shear rate is 60 r / min. When the recovery rate of the viscosity of the metal conductive glue is less than 90%, it indicates that there is agglomeration of metal powder and the metal powder is not fully dispersed. Shearing causes the stable structure in the metal conductive glue to be damaged, resulting in an irreversible change in the viscosity of the metal conductive glue, and the stability of the metal conductive glue is poor. It is necessary to increase the dispersant and extend the dispersion mixing time to further disperse the metal powder in the metal conductive glue; when the viscosity recovery rate of the metal conductive glue is greater than 90%, it indicates that the viscosity of the metal conductive glue recovers quickly, the structure reorganization ability of the metal conductive glue is strong, and the dispersion stability of the metal conductive glue is good.

[0062] In one embodiment, the epoxy resin adhesive is a photo-thermal dual-curing adhesive. In this embodiment, the photo-thermal dual-curing adhesive is first preliminarily positioned by UV light curing, enabling the glue to rapidly reach a certain bonding strength in the initial stage, and then undergoes thermal curing in a suitable temperature environment, ensuring that the glue can be rapidly cured within a short time, thereby improving production efficiency; after dual curing by UV light and heat, the photo-thermal dual-curing adhesive has a higher bonding strength, resulting in a relatively high bonding strength between the cured circuit layer and the plastic carrier; the cured photo-thermal dual-curing adhesive can withstand a relatively high temperature, enabling the cured circuit layer to maintain stable performance in a high-temperature environment, ensuring the reliability and stability between the plastic carrier and the cured circuit layer

[0063] In one embodiment, curing the preset circuit adhesive layer to form a cured circuit layer on the surface of the plastic carrier includes the following steps:

[0064] Performing photo-curing on the preset circuit adhesive layer on the surface of the plastic carrier by a UV lamp;

[0065] Performing thermal curing on the photo-cured preset circuit adhesive layer to form a cured circuit layer on the surface of the plastic carrier. In this embodiment, when performing photo-curing on the preset circuit adhesive layer, since the metal conductive adhesive contains metal powder, the polymer inside the formed transition metal adhesive layer of the cured circuit layer is not fully cured. By performing thermal curing on the transition metal coating, the polymer inside the transition metal adhesive layer further undergoes crosslinking, thereby making the bonding strength between the transition metal and the plastic carrier higher.

[0066] Further, the irradiation time of the UV lamp is 10s - 20s, the temperature of the thermal curing is 80°C - 100°C, and the time of the thermal curing is 5min - 10min. In this embodiment, since the preset circuit adhesive layer is relatively thin, through the irradiation of the UV lamp, the metal conductive adhesive is rapidly cured within 10s - 20s. The UV lamp has a fast curing speed for the metal conductive adhesive, thereby enabling the cured circuit layer to be rapidly cured and formed, thus accelerating the preparation speed of the copper-plated antenna.

[0067] Further, in one embodiment, the photo-thermal dual-curing adhesive includes the following mass components:

[0068] Epoxy acrylate: 30 parts - 60 parts;

[0069] Acrylate monomer: 2 parts - 10 parts;

[0070] Epoxy curing agent modified amine: 5 parts - 8 parts

[0071] Accelerator BDMA: 0.5 parts - 1.5 parts;

[0072] Photoinitiator TPO: 2 parts - 3.5 parts;

[0073] Thermal initiator BPO: 1 part - 1.5 parts. In this embodiment, through the photoinitiator TPO, the epoxy acrylate rapidly undergoes preliminary crosslinking and curing when irradiated with ultraviolet light; acrylate monomers are usually used to adjust the viscosity and curing rate of the adhesive. Adjusting the acrylate monomers can adjust the viscosity of the dual photo-thermal curing adhesive, and controlling the acrylate monomer to be 2% - 10% to obtain a dual photo-thermal curing adhesive with a higher viscosity; through the thermal initiator BPO which is benzoyl peroxide, benzoyl peroxide decomposes to generate free radicals to initiate the polymerization reaction of the epoxy acrylate when heated to a certain temperature; the decomposition temperature of the thermal initiator BPO containing benzoyl peroxide is about 80 - 100 °C, and the temperature adaptation range of the epoxy curing agent modified amine is 80 - 120 °C to match the synergistic thermal initiator BPO; the accelerator BDMA can accelerate the decomposition of the curing agent and the polymerization reaction of the resin, thereby increasing the curing rate and degree of curing. The thermal curing agent BDMA is N,N-dimethylbenzylamine, and when N,N-dimethylbenzylamine is heated, it forms a three-dimensional network structure by highly crosslinking with the epoxy acrylate, thereby further curing the system of the dual photo-thermal curing adhesive.

[0074] Furthermore, in one embodiment, the epoxy resin adhesive can also be an AB epoxy resin adhesive. In this embodiment, the AB epoxy resin adhesive includes component A adhesive and component B adhesive. Component A contains components such as epoxy resin, filler, and accelerator, while component B contains components such as curing agent, catalyst, and plasticizer; metal powder and dispersant are first added to component A and mixed evenly, and the component A with metal powder and component B are mixed evenly at a ratio of 1:1 through a two-component dispenser to obtain a metal conductive adhesive.

[0075] In one embodiment, after the cured circuit layer is finely ground to make the surface of the cured circuit layer flat to form a transition metal adhesive layer, before electroless copper plating on the cured transition metal adhesive layer, the following steps are further included:

[0076] The surface of the finely ground cured circuit layer is purged. In this embodiment, debris remains on the surface of the cured circuit layer after fine grinding. By purging the surface of the cured circuit layer, the surface of the cured circuit layer is kept clean, which is beneficial to the subsequent copper plating process.

[0077] Furthermore, in one embodiment, after the cured circuit layer is finely ground to form a transition metal adhesive layer, before electroless copper plating on the cured transition metal adhesive layer, the following steps are further included:

[0078] The cured circuit layer is chemically roughened by soaking it in a CrO3-H2SO4 roughening solution. In this embodiment, CrO3 can oxidize the organic matter on the surface of the epoxy resin under acidic conditions, exposing metal powders such as copper or silver further, making it easier for the copper elemental layer to deposit on the surface of the cured circuit layer during electroless copper plating, thereby increasing the surface roughness and improving the bonding strength of the copper elemental deposition on the surface of the cured circuit layer; when the metal powder is easily oxidized in air, the metal oxide will reduce the adhesion of the copper elemental deposition on the metal powder, affecting the bonding strength between the copper plating layer and the cured circuit layer. Through the pickling of the CrO3-H2SO4 roughening solution, the oxide on the surface of the metal powder is removed, exposing the metal powder, and further improving the adhesion between the electroless copper plating layer and the cured circuit layer.

[0079] It can be understood that since the thickness of the cured circuit layer is relatively thin, when the soaking time in the CrO3-H2SO4 roughening solution is too long, the cured circuit layer is easily damaged. Therefore, the soaking time of the CrO3-H2SO4 roughening solution is 5 min - 10 min. When the soaking time is greater than 10 min, the cured circuit layer is likely to be severely damaged, so the soaking time needs to be controlled within 10 min; when the soaking time is less than 5 min, the soaking time is too short, making the roughening effect of the CrO3-H2SO4 roughening solution on the cured circuit layer not obvious and the effect of removing the oxide on the surface of the metal powder is poor.

[0080] Further, after curing the preset circuit adhesive layer to form a cured circuit layer on the surface of the plastic carrier, before finely grinding the cured base layer, the following steps are further included:

[0081] Coat an alkali-soluble dry film solution on the surface of the plastic carrier and obtain a dry film layer after curing;

[0082] In this embodiment, the alkali-soluble dry film solution is prepared by compounding an alkali-soluble resin, a photosensitive monomer, a photoinitiator and a solvent; the alkali-soluble resin is a copolymer of methacrylic acid or hydroxyethyl methacrylate, providing alkaline developing solubility through carboxyl groups; when the cured circuit layer is finely ground, the dry film layer covering the surface of the cured circuit layer is removed, exposing the surface of the cured circuit layer, and the deposition of the plating solution in the area covering the dry film layer is prevented through the dry film layer, thereby precisely controlling the copper plating edge of the cured circuit layer; it can be understood that when the surface of the plastic carrier is covered with a dry film layer, the dry film layer also blocks the contact between the CrO3-H2SO4 roughening solution and the plastic carrier, avoiding the oxidation and corrosion of the plastic carrier layer by the CrO3-H2SO4 roughening solution, so that the CrO3-H2SO4 roughening solution precisely roughens the surface of the cured circuit layer.

[0083] Further, after electroless copper plating is performed on the heat-cured transition metal adhesive layer to form an antenna circuit, the dry film layer of the copper-plated antenna is removed by a stripping solution. In this embodiment, the stripping solution includes sodium hydroxide, an organic solvent, a buffer, etc. The alkalinity of sodium hydroxide can break the chemical bonds of the polymer, thereby achieving the effect of stripping the film. The organic solvent N-methylpyrrolidone can accelerate the film stripping process by dissolution, and the buffer is used to stabilize the pH value of the stripping solution; after the dry film layer of the copper-plated antenna is removed by the stripping solution, the edges of the antenna circuit become clearer and more precise.

[0084] As Figure 2 shown, the present application also provides a copper-plated antenna 10 prepared by using the preparation method of the metal conductive adhesive copper-plated antenna described in any of the above embodiments. The copper-plated antenna 10 includes a plastic carrier 100 and an antenna circuit 200. The antenna circuit 200 includes a transition metal adhesive layer 210 and a copper plating layer 220. The transition metal adhesive layer 210 covers the surface of the plastic carrier 100, and the copper plating layer 220 covers the surface of the transition metal adhesive layer 210. The transition metal adhesive layer 210 includes a cured epoxy resin adhesive layer 211 and metal powder particles 212, and the metal powder particles 212 are uniformly distributed in the cured epoxy resin adhesive layer 212. In this embodiment, the binding strength between the transition metal adhesive layer 210 and the copper plating layer 220 and the plastic carrier 100 of the copper-plated antenna 10 prepared by the preparation method of the metal conductive adhesive copper-plated antenna is relatively high, so that the conduction effect of the antenna circuit formed by the copper plating layer 220 and the transition metal adhesive layer 210 is better, and the surface of the copper plating layer 220 is relatively flat.

[0085] Compared with the prior art, the present disclosure has at least the following advantages:

[0086] In the above-mentioned preparation method of the metal conductive adhesive copper-plated antenna, by pre-coating the metal conductive adhesive on the surface of the plastic carrier and then performing electroless copper plating, the usage amount of the metal conductive adhesive is less and the operation is simple, so that the cost of preparing the copper-plated antenna is relatively low; by combining the metal conductive adhesive with the plastic carrier, the antenna circuit formed by electroless copper plating of the metal conductive adhesive is tightly combined with the plastic carrier, improving the structural strength of the antenna circuit and the plastic carrier; after the metal conductive adhesive is cured, a cured circuit layer is formed, and the thickness of the cured circuit layer can be controlled by fine grinding, so that the surface of the antenna circuit formed after electroless copper plating is flat and the conduction effect of the conduction path is better.

[0087] The above embodiments only represent several implementation manners of the present disclosure, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the disclosed patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several deformations and improvements can still be made, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent shall be subject to the appended claims.

Claims

1. A preparation method of a metal conductive adhesive copper-plated antenna, characterized in that, It includes the following steps: Add metal powder and dispersant into epoxy resin glue in sequence and mix evenly to obtain metal conductive glue; Inject to obtain a plastic carrier; Coat the surface of the plastic carrier with the metal conductive glue through a dispensing machine to obtain a preset circuit glue layer; Cure the preset circuit glue layer so that a cured circuit layer is formed on the surface of the plastic carrier; Finely grind the cured circuit layer so that the surface of the cured circuit layer is flat to form a transition metal glue layer; Perform electroless copper plating on the cured transition metal glue layer to form an antenna circuit and obtain a copper-plated antenna.

2. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 1, wherein Add metal powder and dispersant into epoxy resin glue in sequence and mix evenly to obtain metal conductive glue, and it further includes the following steps: Crush the metal powder; Sieve the crushed metal powder.

3. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 2, characterized in that, The particle size of the metal powder is 1μm - 5μm.

4. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 3, characterized in that, The thickness of the transition metal glue layer is 15μm - 40μm.

5. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 1, characterized in that, The metal powder includes at least one of copper powder and silver powder.

6. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 1, characterized in that, The metal conductive glue includes the following mass components: Epoxy resin glue: 30 parts - 60 parts; Dispersant: 2 parts - 10 parts; Metal powder: 20 parts - 40 parts.

7. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 1, wherein, The epoxy resin glue is a photo-thermal dual-curing glue.

8. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 7, wherein Cure the preset circuit glue layer so that a cured circuit layer is formed on the surface of the plastic carrier, and it includes the following steps: Perform photo-curing on the preset circuit glue layer on the surface of the plastic carrier through a UV lamp; Perform thermal curing on the photo-cured preset circuit glue layer so that a cured circuit layer is formed on the surface of the plastic carrier.

9. The preparation method of the copper-plated antenna with metal conductive adhesive according to claim 1, characterized in that, Before performing electroless copper plating on the cured transition metal glue layer after finely grinding the cured circuit layer so that the surface of the cured circuit layer is flat to form a transition metal glue layer, it further includes the following steps: Blow the surface of the finely ground cured circuit layer.

10. A copper-plated antenna, characterized in that, Prepared by the method for preparing a copper-plated antenna using the metal conductive glue according to any one of claims 1 - 9, the copper-plated antenna includes a plastic carrier and an antenna circuit, the antenna circuit includes a copper-plated layer and a transition metal glue layer, the transition metal glue layer covers the surface of the plastic carrier, the copper-plated layer covers the surface of the transition metal glue layer, the transition metal glue layer includes cured epoxy resin glue and metal powder, and the metal powder is evenly distributed in the cured epoxy resin glue.

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