WO2022037153A1 - Composite substrate, electronic device, and manufacturing method for composite substrate - Google Patents

Abstract

A composite substrate, an electronic device, and a manufacturing method for a composite substrate. The composite substrate is prepared by disposing a transition layer between a substrate layer and a conductive layer. The transition layer is made of a first adhesive material. The first adhesive material tightly adheres to a carbon fiber composite material of the substrate layer and a metal material of the conductive layer, thus enhancing the adhesion between the metal layer and the substrate layer, and preventing the release of the metal layer.

Description

Composite substrate, electronic device and method for making composite substrate

This application claims the priority of the Chinese patent application filed on August 19, 2020 with the application number 202010838679.7 and the application title is "Composite Substrate, Electronic Device and Method for Making the Composite Substrate", the entire content of which is approved by Reference is incorporated in this application.

technical field

The present application relates to the technical field of communication equipment, and in particular, to a composite substrate, an electronic device and a method for manufacturing the composite substrate.

Background technique

With the rapid development of communication equipment technology, consumers' demand for electronic equipment gradually tends to be thin and light. Because carbon fiber composite materials have the advantages of high specific strength, high specific modulus, corrosion resistance, low density, etc., they can replace stainless steel and other metal materials, so they are widely used in aerospace, automotive and communication fields to achieve lightweight requirements. . However, carbon fiber composite materials are poor conductors with poor electrical conductivity, which have an impact on the radio frequency efficiency of mobile phones, and may lead to problems such as stray radiation, which limits their application in the field of communication equipment to a large extent. Therefore, it is particularly important to metallize the surface of carbon fiber composites to improve their electrical conductivity.

In the prior art, before the surface of the carbon fiber composite material is metallized, the surface of the carbon fiber composite material is usually roughened. After drying, the surface is treated with plasma treatment or acid etching to achieve surface roughening, and then a layer of metal layer (such as copper, nickel, etc.) is sputtered on the surface by physical vapor deposition (PVD) technology, and then electroplating Copper, wash the surface with water after copper plating, and then carry out nickel electroplating. After nickel plating, wash the surface with water again, and finally dry the surface of the carbon fiber composite material to complete all operations of metallization.

However, the adhesion between the metal layer and the surface of the substrate after metallization in the above-mentioned manner is weak, and the phenomenon of the metal layer falling off easily occurs.

SUMMARY OF THE INVENTION

Embodiments of the present application provide a composite substrate, an electronic device, and a method for manufacturing the composite substrate, which can enhance the adhesion between the metal layer and the surface of the substrate and avoid the phenomenon of the metal layer falling off.

A first aspect of the embodiments of the present application provides a composite substrate, the composite substrate includes: a substrate layer, a conductive layer, and a transition layer between the substrate layer and the conductive layer; the substrate layer is In the carbon fiber composite material, the conductive layer is a metal material; the transition layer is made of a first adhesion material, and the first adhesion material is used to be tightly combined with the carbon fiber composite material and the metal material respectively.

In the composite substrate provided in the embodiment of the present application, a transition layer is formed between the substrate layer and the conductive layer, and the transition layer is made of a first adhesion material, and the first adhesion material is used to be closely attached to the carbon fiber composite material and the metal material respectively. In combination, the adhesion between the base material layer and the conductive layer can be enhanced, so as to avoid the phenomenon that the metal layer falls off.

In a possible implementation manner, the carbon fiber composite material includes a carbon fiber material and a resin material; wherein the resin material is a thermoplastic resin or a thermosetting resin; the resin material is epoxy resin, polyurethane, polyester, nylon, Any one or more of polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate, polyoxymethylene, phenolic resin or amino resin.

In a possible implementation manner, the first attachment material at least includes: a resin matrix and a metal complex, the resin matrix is used for tightly bonding with the carbon fiber composite material, and the metal complex is used for bonding with the carbon fiber composite material. The metal materials are tightly bonded.

In this way, since the resin matrix in the first attachment material has good wettability with the carbon fiber surface and epoxy resin substrate in the carbon fiber composite material, it can chemically combine with polar groups such as active groups C=O and COC on the carbon fiber surface. , forming a strong chemical bond, so the first adhesion material has a strong bond with the carbon fiber composite material, and the adhesion is good. Moreover, the metal complex in the first attachment material will absorb energy to generate metal monomer after laser engraving activation, and the generated metal particles can be evenly distributed on the substrate layer, that is, the surface layer of the carbon fiber composite material. During the electroless plating process, the copper ions in the plating solution will be reduced to metallic copper by formaldehyde, which will attach to the area containing the metal monomer (that is, the area where the laser engraving is activated) to form a strong metal bond. Because the metal atoms have a strong attraction before Therefore, the adhesion between the conductive layer of the composite substrate and the substrate layer is good, and it is not easy for the metal layer to fall off.

In a possible implementation manner, the resin matrix is epoxy resin, polyurethane, polyester, nylon, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate, polyoxymethylene, phenolic Any one or more of resins or amino resins.

In a possible implementation, the metal complex is copper complex, magnesium complex, palladium complex, iron complex, silver complex, nickel complex or molybdenum complex any one or more of them.

In a possible implementation manner, the metal material is any one or more of copper, silver or gold.

In a possible implementation manner, the thickness of the conductive layer is 1-20um.

In a possible implementation manner, the conductive layer includes a first conductive layer and a second conductive layer; the first conductive layer is located between the transition layer and the second conductive layer.

In a possible implementation manner, the thickness of the first conductive layer is 1-10 um; the thickness of the second conductive layer is 1-10 um.

In a possible implementation manner, the thickness of the transition layer is 10-50um.

In a possible implementation manner, the method further includes: a protective layer; the conductive layer is located between the protective layer and the transition layer. By disposing the protective layer on the conductive layer, the oxidation reaction of the conductive layer in the air can be avoided.

In a possible implementation manner, the protective layer adopts a second adhesion material, and the second adhesion material is an inert metal.

In a possible implementation manner, the second attachment material is nickel or tin.

In a possible implementation manner, the thickness of the protective layer is 1-10 um.

A second aspect of the embodiments of the present application provides an electronic device, including at least: a middle frame and a back cover; any one or both of the middle frame and the back cover are made of the composite substrate described above production.

The electronic equipment provided in the embodiments of the present application is made by using composite substrates for components such as a middle frame and a back cover in the electronic equipment, because the composite substrate not only has high specific strength, high specific modulus, corrosion resistance, low Density and other advantages, it can also reflect good electrical conductivity in the radiation area, and the adhesion between the metal layer and the substrate layer in the composite substrate is large enough to prevent the metal layer from falling off. Therefore, the service life of the electronic device can be guaranteed, and the user experience effect can be improved.

In a possible implementation, it further includes: a rotating shaft and a door panel; any one or both of the rotating shaft and the door panel are made of the composite substrate; at least part of the rotating shaft is made of the composite material base material.

A third aspect of the embodiments of the present application provides a method for manufacturing a composite substrate, including: at least providing a carbon fiber composite material, a metal material, and a first attachment material; the carbon fiber composite material forms a substrate layer; disposing the first adhesion material, the first adhesion material forms a transition layer; disposing the metal material on the transition layer, the metal material forming a conductive layer; wherein, the first adhesion material is used to connect with the The carbon fiber composite material and the metal material are closely combined.

In the manufacturing method of the composite substrate provided in the embodiment of the present application, a substrate layer is formed by using a carbon fiber composite material, a first adhesion material is arranged on the substrate layer, the first adhesion material forms a transition layer, a metal material is arranged on the transition layer, and a metal material is formed on the transition layer. The material forms a conductive layer, and the first adhesion material of the transition layer is used to be tightly combined with the carbon fiber composite material of the base material layer and the metal material of the conductive layer, which can enhance the adhesion between the base material layer and the conductive layer and avoid the occurrence of metal The phenomenon of layer shedding.

In a possible implementation manner, the first attachment material at least includes: a resin matrix and a metal complex, the resin matrix is used for tightly bonding with the carbon fiber composite material, and the metal complex is used for bonding with the carbon fiber composite material. The metal materials are tightly bonded.

In this way, since the resin matrix in the first attachment material has good wettability with the carbon fiber surface and epoxy resin substrate in the carbon fiber composite material, it can chemically combine with polar groups such as active groups C=O and COC on the carbon fiber surface. , forming a strong chemical bond, so the first adhesion material has a strong bond with the carbon fiber composite material, and the adhesion is good. Moreover, the metal complex in the first attachment material will absorb energy to generate metal monomer after laser engraving activation, and the generated metal particles can be evenly distributed on the substrate layer, that is, the surface layer of the carbon fiber composite material. During the electroless plating process, the copper ions in the plating solution will be reduced to metallic copper by formaldehyde, which will attach to the area containing the metal monomer (that is, the area where the laser engraving is activated) to form a strong metal bond. Because the metal atoms have a strong attraction before Therefore, the adhesion between the conductive layer of the composite substrate and the substrate layer is good, and it is not easy for the metal layer to fall off.

In a possible implementation manner, the disposing the first adhesion material on the base material layer, and the first adhesion material forming a transition layer, includes: using a coating process to spray the first adhesion material On the upper surface of the substrate layer, the first attachment material forms a transition layer.

In a possible implementation manner, the disposing the first attachment material on the base material layer, and after the first attachment material forms the transition layer, further comprising: using a laser engraving process on the transition layer at least part of it is laser-treated.

In a possible implementation manner, the disposing the metal material on the transition layer, the metal material forming a conductive layer, includes:

disposing a metal material on the transition layer to form a first conductive layer;

A metal material is disposed on the first conductive layer to form a second conductive layer.

In a possible implementation manner, the disposing the metal material on the transition layer, after the metal material forms the conductive layer, further includes: providing a second attachment material; disposing the metal material on the conductive layer The second adhesion material forms a protective layer.

By disposing the protective layer on the conductive layer, the oxidation reaction of the conductive layer in the air can be avoided.

In a possible implementation manner, the second attachment material is an inert metal.

Description of drawings

FIG. 1 is a schematic structural diagram of a composite substrate provided in an embodiment of the application;

FIG. 2 is another schematic structural diagram of the composite substrate provided in the embodiment of the present application;

3 is another schematic structural diagram of the composite substrate provided by the embodiment of the present application;

4 is a schematic flowchart of a method for manufacturing a composite substrate provided in an embodiment of the present application;

Fig. 5 is another schematic flow chart of the manufacturing method of the composite substrate provided by the embodiment of the present application;

Fig. 6 is another schematic flow chart of the manufacturing method of the composite substrate provided by the embodiment of the present application;

Fig. 7 is another schematic flow chart of the manufacturing method of the composite substrate provided by the embodiment of the present application;

FIG. 8 is another schematic flowchart of the manufacturing method of the composite substrate provided by the embodiment of the present application.

Description of reference numbers:

100-composite substrate; 10-substrate layer; 20-transition layer; 30-conductive layer; 301-first conductive layer; 302-second conductive layer; 40-protective layer.

detailed description

The terms used in the embodiments of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application. The following will describe the embodiments of the embodiments of the present application in detail with reference to the accompanying drawings.

Carbon Fiber (CF) refers to a new type of fiber material with high strength and high modulus fiber with a carbon content of more than 95%. And the microcrystalline graphite material obtained by graphitization treatment, the quality of carbon fiber is lighter than that of metal aluminum, but the strength is higher than that of steel, it has the characteristics of corrosion resistance and high modulus, it has the inherent characteristics of carbon material, and it has both textile fibers. of soft workability. In addition, carbon fiber has high axial strength and modulus, low density, high specific performance, no creep, ultra-high temperature resistance in non-oxidizing environment, good fatigue resistance, specific heat and electrical conductivity between non-metals and metals It has small thermal expansion coefficient and anisotropy, good corrosion resistance, good X-ray permeability, good electrical and thermal conductivity and electromagnetic shielding performance.

Epoxy resin refers to the general term of a class of polymers containing two or more epoxy groups in the molecule, and is the polycondensation product of epichlorohydrin and bisphenol A or polyol. Due to the chemical activity of the epoxy group, a variety of compounds containing active hydrogen can be used to open the ring, and cure and crosslink to form a network structure.

The carbon fiber and epoxy resin composite material (ie carbon fiber epoxy resin composite material), its specific strength and specific modulus are several times larger than steel and aluminum alloy and other materials, with excellent chemical stability, friction reduction and wear resistance, Self-lubrication, heat resistance, fatigue resistance, creep resistance, noise reduction, electrical insulation and other properties, and the composite of graphite fiber and resin can obtain a material with an expansion coefficient almost equal to zero. Therefore, because carbon fiber epoxy resin composites have a series of advantages such as high specific strength, high specific modulus, corrosion resistance, and low density, compared with metal materials such as stainless steel, they can not only reduce weight, but also have sufficient structural strength to achieve Strength requirements, widely used in aerospace, automotive and mobile phone fields, etc., to achieve lightweight requirements. However, since the carbon fiber epoxy resin composite material is a poor conductor, there is a big gap between its conductivity and metal materials, and it has strong wave absorption properties, which will generate high-order harmonics, which will affect the radio frequency efficiency of mobile phones. It is very likely to cause stray radiation problems, causing problems in the radiation performance of the antennas of communication equipment, which limits its application in the field of communication equipment to a large extent.

Metal is a substance with luster (that is, strong reflection of visible light), ductility, and easy electrical conductivity and thermal conductivity. At present, metallizing the surface of carbon fiber epoxy resin composites can improve the performance of carbon fiber epoxy resin composites. Conductivity, which can not only solve or reduce the impact of carbon fiber epoxy resin composite material on the radiation performance of antennas in communication equipment, etc., but also enable carbon fiber epoxy resin composite material to reflect good electrical conductivity in the radiation area.

In the prior art, there are various preparation methods for surface metallization of carbon fiber epoxy resin composite materials, such as electroplating or electroless plating or chemical vapor deposition (Chemical vapor deposition, CVD)/physical vapor deposition (Physical vapor deposition) after surface roughening. decomposition, PVD) and electroplating after depositing several micron metal conductive layers. Taking electroplating or electroless plating after surface roughening as an example, the surface of the carbon fiber epoxy resin composite material is first roughened (such as strong acid, strong alkali, plasma, etc.), and then the surface is cleaned with water, and the carbon fiber epoxy resin The composite material is corroded in concentrated sulfuric acid and hydrogen peroxide solution, roughened and oxidized in hot concentrated nitric acid, the surface is washed with water, activated by palladium precipitation, and then electroless or electroplated with copper and nickel. Taking chemical vapor deposition (Chemical vapor deposition, CVD)/physical vapor deposition (Physical vapor deposition (PVD)) after surface roughening to deposit several micron metal conductive layers and then electroplating as an example, the surface of carbon fiber epoxy resin composites is first After roughening treatment (such as strong acid, strong alkali, plasma, etc.), and then cleaning the surface with water, a conductive layer (metal nickel or titanium or copper) of several microns is deposited on the surface of the carbon fiber epoxy resin composite by CVD/PVD technology. , or conductive sulfide, etc.), and then electroplating copper and nickel, etc.

However, in the actual use scenarios of carbon fiber epoxy resin composites, it is usually required to be processed by Computer Numerical Control (CNC) to achieve complex structures. Due to the different surface states of the materials processed by CNC, the above methods use plasma treatment or acid treatment. The etching process roughens different parts of the material, which is easy to cause the parts where the roughening treatment is not in place or the parts with excessive roughening treatment (the carbon fiber is obviously exposed) after metallization. There is a very high risk of the layers falling off during use. Moreover, the prior art cannot achieve localized metallization of the substrate without protecting a specific area.

Based on this, an embodiment of the present application provides a composite substrate, by arranging a transition layer between the substrate layer and the conductive layer, the transition layer is made of a first adhesion material, and the first adhesion material is used to connect with the substrate respectively. The carbon fiber composite material of the layer and the metal material of the conductive layer are closely combined, which can enhance the adhesion between the metal layer and the base material layer, and avoid the phenomenon of the metal layer falling off.

Referring to FIG. 1 , the composite substrate 100 provided in this embodiment of the present application may include: a substrate layer 10 , a conductive layer 30 , and a transition layer 20 between the substrate layer 10 and the conductive layer 30 , wherein the substrate layer 10 It is a carbon fiber composite material, and the conductive layer 30 is a metal material.

The carbon fiber composite material of the base material layer 10 may include carbon fiber material and resin material, wherein the resin material may be thermoplastic resin or thermosetting resin, for example, the resin material may be polyethylene, polypropylene, polystyrene, polymethyl methacrylate , nylon, polycarbonate or polyoxymethylene, etc., it can also be phenolic resin, amino resin or unsaturated polyester, etc., and the resin material can also be epoxy resin, polyurethane, polyester, etc. Of course, in some other embodiments, the base material layer 10 may also be other fibers, thermosetting resins, thermoplastic resins, or composite materials with spraying.

For example, in a possible implementation manner, the carbon fiber composite material of the base material layer 10 may be a carbon fiber epoxy resin composite material.

In the embodiment of the present application, the transition layer 20 may be made of a first adhesion material, and the first adhesion material is used to be tightly combined with the carbon fiber composite material and the metal material, respectively. Specifically, the first attachment material may at least include: a resin matrix and a metal complex, wherein the resin matrix is used for tightly bonding with the carbon fiber composite material, and the metal complex is used for bonding with the metal material.

The resin matrix can be any one of epoxy resin, polyurethane, polyester, nylon, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate, polyoxymethylene, phenolic resin or amino resin or variety. The metal complex may be any one or more of copper complex, magnesium complex, palladium complex, iron complex, silver complex, nickel complex or molybdenum complex.

In this embodiment of the present application, as shown in FIG. 1 , the thickness d1 of the transition layer 20 may be 10-50 μm, for example, the thickness d1 of the transition layer 20 may be 20 μm, 30 μm, 40 μm, etc. It is not limited to the above-mentioned examples.

In a possible implementation manner, the transition layer 20 may be a laser-activated ink layer. Specifically, the components of the laser-activated ink layer may include a resin matrix, a solvent, a laser-activated metal complex powder, a curing agent, and other additives Such as surfactants, light stabilizers, antioxidants, etc.

Wherein, the solvent can be xylene, n-butanol, cyclohexanone, acetone, ester, etc., one or more mixed solvents of ketones, esters, ether alcohols and chlorinated hydrocarbons. The curing agent may be selected from isocyanates or other curing agents suitable for use in resin matrices such as epoxy resins and polyurethanes.

In the embodiment of the present application, a coating process can be used to coat the laser-activated ink on the upper surface of the base material layer 10, for example, a sprayer can be used to spray the laser-activated ink on the upper surface of the base material layer 10, and then laser engraving An activation process is performed to form the transition layer 20 . It should be noted that laser engraving is also called laser engraving or laser marking. It is a process of surface treatment using optical principles (laser processing principles). It refers to the use of high-intensity focused laser beams emitted by lasers at the focal point. Oxidation is then processed, that is, the chemical and physical changes of the surface material are caused by the light energy of the laser beam to engrave traces, or the light energy burns off part of the material to reveal the desired etched graphics and text.

In this embodiment of the present application, the thickness of the conductive layer 30 may be 1-20 um. The metal material of the conductive layer 30 may be any one or more of metals such as copper, silver or gold.

In this embodiment of the present application, as shown in FIG. 2 , the conductive layer 30 may include a first conductive layer 301 and a second conductive layer 302 , wherein the first conductive layer 301 is located between the transition layer 20 and the second conductive layer 302 .

The thickness d2 of the first conductive layer 301 may be 1-10 μm, for example, the thickness d2 of the first conductive layer 301 may be 2 μm, 3 μm, 4 μm, etc., which is not limited in the embodiments of the present application, nor is it limited to the above examples. The thickness d3 of the second conductive layer 302 may also be 1-10um, for example, the thickness d3 of the second conductive layer 302 may be 4um, 6um, 8um, etc., which is not limited in the embodiments of the present application, nor is it limited to the above examples .

As an optional implementation, an electroless plating process may be used to form a thin conductive layer (the first conductive layer 301 ) on the transition layer 20 , and then an electroless plating process may be used to form a thin conductive layer on the first conductive layer 301 . A thicker conductive layer (second conductive layer 302), when the first conductive layer 301 and the second conductive layer 302 are copper, the electroless copper plating solution may contain copper sulfate, ethylenediaminetetraacetic acid, hydroxide Sodium and formaldehyde, among them, the function of ethylenediaminetetraacetic acid is to stabilize the concentration of copper ions and prevent the precipitation of copper hydroxide, sodium hydroxide is used to adjust the pH balance, and formaldehyde is used as a reducing agent.

Of course, in some other embodiments, the first conductive layer 301 and the second conductive layer 302 may also be two different metal materials. For example, the first conductive layer 301 may be copper, and the second conductive layer 302 may be silver. Moreover, the thickness of the first conductive layer 301 can be smaller than the thickness of the second conductive layer 302, the thickness of the first conductive layer 301 can also be equal to the thickness of the second conductive layer 302, or the thickness of the first conductive layer 301 can also be greater than the thickness of the second conductive layer 301. The thickness of the conductive layer 302 is not limited in this embodiment of the present application.

Referring to FIG. 3 , the composite substrate 100 may further include a protective layer 40 , and the conductive layer 30 is located between the protective layer 40 and the transition layer 20 . By disposing the protective layer 40 on the conductive layer 30 , the oxidation reaction of the conductive layer 30 in the air can be avoided.

In the embodiment of the present application, the protective layer 40 adopts a second adhesion material, and the second adhesion material may be an inert metal, for example, the second adhesion material may be nickel or tin.

In a possible implementation manner, the thickness d4 of the protective layer 40 may be 1-10 um. For example, the thickness d4 of the protective layer 40 may be 4um, 6um, 8um, etc., which is not limited in the embodiments of the present application, nor is it limited to the above examples.

As an optional embodiment, the protective layer 40 may be formed on the conductive layer 30 by an electroless plating process. For example, when the protective layer 40 is nickel, that is, nickel is plated on the conductive layer 30, the electroless nickel plating solution may It contains main salt nickel sulfate (NiS04·7H20), formaldehyde, sulfuric acid solution or sodium hydroxide solution, etc. Among them, formaldehyde is used as a reducing agent, and sulfuric acid solution or sodium hydroxide solution is used to adjust the pH balance.

It should be noted that, in the prior art, after the carbon fiber composite material is processed by CNC (such as CNC lathe processing, CNC milling machine processing or CNC boring and milling machine processing, etc.), the carbon fiber in the CNC processing area will be exposed on the surface, and, through acid or After the plasma roughening treatment, the exposed area of the carbon fiber will increase. Due to the high inertness of the surface of carbon fiber, low surface energy, lack of chemically active chemical bonds, low reactivity, and poor compatibility with metals such as copper or nickel during metallization, it will lead to low adhesion after metallization. The adhesion between the substrate layers (carbon fiber reinforced epoxy resin composite materials) is low, and the phenomenon of metal layer peeling off easily occurs. Moreover, although carbon fiber is generally pre-oxidized before leaving the factory, its surface contains some active groups such as polar groups such as C=O and COC, which have a certain mechanical bond with copper, but the C-Cu cross-section bond is very weak. , so it still cannot meet the requirements of adhesion.

The examples of the present application do not need to roughen the surface of the CNC-processed substrate, and after spraying the laser-activated ink, the exposed carbon fiber problem caused by CNC processing is covered, and the exposed surface area of the carbon fiber is reduced. The ink has good wettability with the carbon fiber surface and epoxy resin substrate, and can chemically combine with polar groups such as active groups C=O and COC on the carbon fiber surface to form a strong chemical bond, so it has a strong bond with the carbon fiber interface. Good adhesion. Moreover, during the laser engraving activation process, the metal complexes in the laser-activated ink absorb energy to generate metal monomers, and the generated metal particles are evenly distributed on the surface of the substrate 10 (carbon fiber reinforced epoxy resin composite material). During the electroless plating process, the copper ions in the plating solution will be reduced to metallic copper by formaldehyde, which will attach to the area containing the metal monomer (that is, the area where the laser engraving is activated) to form a strong metal bond. Because the metal atoms have a strong attraction before Therefore, the metal layer (conductive layer 30 ) of the composite substrate 100 provided in the embodiment of the present application has good adhesion to the surface of the substrate (substrate layer 10 ), and the metal layer is not easy to occur shedding phenomenon.

In addition, the roughening treatment or sputtering treatment in the prior art generally treats the entire substrate. If the part is treated, it needs to be protected. Since the acid etching is to immerse the entire material in the solution, most of the material needs to be protected. The protective film is difficult to withstand the corrosion of concentrated sulfuric acid and concentrated nitric acid, and sometimes the metallization of fine antenna lines cannot be achieved under the condition of protection. Moreover, when the uncovered area is corroded, there is also a phenomenon that the covered area is exposed and corroded. Moreover, the method of sputtering or the use of plasma solution for roughening treatment, the etching accuracy is not high.

However, in this application, by using laser-activated ink, the laser-activated ink is activated by laser laser engraving and then metallized. In the case of no protection of a specific area, the metallization of the local substrate can still be achieved, which can be prepared Get a high-precision antenna line. That is to say, the embodiments of the present application can not only realize the full metallization of the carbon fiber composite material, but also realize the metallization treatment of local fine lines.

Next, an embodiment of the present application further provides an electronic device, the electronic device may at least include: a middle frame and a back cover, and any one or more of the middle frame and the back cover are made of the above-mentioned composite substrate 100 .

The electronic devices provided by the embodiments of the present application may include, but are not limited to, mobile phones, tablet computers, notebook computers, ultra-mobile personal computers (UMPC), handheld computers, walkie-talkies, netbooks, point of sales (Point of sales, POS) machines, personal digital assistants (PDAs), wearable devices, virtual reality devices, wireless U-disks, Bluetooth audio/headphones, or mobile or fixed terminals such as in-vehicle front-mounted devices, driving recorders, and security equipment.

Wherein, in the embodiments of the present application, a mobile phone is used as an example for the above-mentioned electronic device for description. The mobile phone provided in the embodiments of the present application may be a curved screen mobile phone or a flat screen mobile phone, and the mobile phone may include: a display screen, a middle frame, a circuit board and back cover, wherein the circuit board can be arranged on the middle frame, for example, the circuit board can be arranged on the side of the middle frame facing the back cover, or the circuit board can be arranged on the side of the middle frame facing the display screen, the display screen and The back covers are located on both sides of the middle frame.

Wherein, the middle frame may be made of the composite substrate 100 . The back cover can also be made of the composite substrate 100 , and, in some other embodiments, the electronic device can also be a folding screen device, and components such as a hinge or a door panel in the folding screen device can also be made of the composite substrate 100 . become.

Moreover, the rotating shaft in the folding screen device generally includes multiple components, and in the embodiment of the present application, at least part of the components of the rotating shaft may be made of the composite substrate 100 .

In the embodiment of the present application, components such as a middle frame, a back cover or a rotating shaft in an electronic device are made of the composite substrate in the embodiment of the present application. The composite substrate 100 not only has high specific strength, high specific modulus, high resistance to Corrosion, low density and a series of advantages, it can also reflect good electrical conductivity in the radiation area, and the adhesion between the metal layer and the substrate layer in the composite substrate 100 is large enough to prevent the metal layer from falling off. Therefore, the service life of the electronic device can be guaranteed, and the user experience effect can be improved.

It can be understood that the structures illustrated in the embodiments of the present application do not constitute a specific limitation on the electronic device. In other embodiments of the present application, the electronic device may include more or less components than shown, or combine some components, or separate some components, or arrange different components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

Referring to FIG. 4 , an embodiment of the present application further provides a method for fabricating a composite substrate 100 , and the fabrication method may include:

S101: Provide at least a carbon fiber composite material, a metal material, and a first attachment material.

Carbon fiber composite materials include carbon fiber materials and resin materials, wherein the resin materials can be thermoplastic resins or thermosetting resins, for example, epoxy resin materials can be polyethylene, polypropylene, polystyrene, polymethyl methacrylate, nylon, polystyrene, etc. Carbonate, polyoxymethylene, etc., may also be phenolic resin, amino resin, or unsaturated polyester, etc., and the resin material may also be epoxy resin, polyurethane, polyester, and the like. Of course, in some other embodiments, the base material layer 10 may also be other fibers, thermosetting resins, thermoplastic resins, or composite materials with spraying.

For example, in a possible implementation manner, the carbon fiber composite material of the base material layer 10 may be a carbon fiber epoxy resin composite material.

The first attachment material is used for tightly bonding with the carbon fiber composite material and the metal material, respectively. The first attachment material may at least include: a resin matrix and a metal complex, wherein the resin matrix is used for tightly bonding with the carbon fiber composite material, and the metal complex is used for bonding with the metal material. The resin matrix can be any one of epoxy resin, polyurethane, polyester, nylon, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate, polyoxymethylene, phenolic resin or amino resin or variety. The metal complex may be any one or more of copper complex, magnesium complex, palladium complex, iron complex, silver complex, nickel complex or molybdenum complex.

In a possible implementation manner, the first attachment material may be a laser-activated ink. Specifically, the components of the laser-activated ink may include a resin matrix, a solvent, a laser-activated metal complex powder, a curing agent, and other additives such as Surfactant, light stabilizer, antioxidant, etc. Wherein, the solvent can be xylene, n-butanol, cyclohexanone, acetone, ester, etc., one or more mixed solvents of ketones, esters, ether alcohols and chlorinated hydrocarbons. The curing agent may be selected from isocyanates or other curing agents suitable for use in resin matrices such as epoxy resins and polyurethanes.

The metal material can be any one or more of metals such as copper, silver or gold.

S103 : The carbon fiber composite material forms the base material layer 10 .

S105 : disposing a first adhesion material on the base material layer 10 , and the first adhesion material forms a transition layer 20 .

In the embodiment of the present application, the thickness d1 of the transition layer 20 may be 10-50um, for example, the thickness d1 of the transition layer 20 may be 20um, 30um, 40um, etc., which is not limited or limited in the embodiment of the present application. Example above.

Specifically, as shown in FIG. 5 , S105 may include:

S1051 : using a coating process to spray the first adhesion material on the upper surface of the base material layer 10 , and the first adhesion material forms the transition layer 20 . Specifically, the first adhesion material may be sprayed on the upper surface of the base material layer 10 by spraying, dip coating or blade coating process, and the first adhesion material forms the transition layer 20 .

As an optional embodiment, the configured laser-activated ink can be uniformly sprayed on the surface of the substrate layer 10 with a sprayer, and the spraying thickness can be 10-50um, and then baked and cured at a certain temperature.

S107 : disposing a metal material on the transition layer 20 , and the metal material forms the conductive layer 30 .

In this embodiment of the present application, after S105, as shown in FIG. 6, the manufacturing method may further include:

S106: Use a laser radium engraving process to perform laser processing on at least part of the transition layer 20.

Specifically, a laser can be used to scan at least a part of the transition layer 20, and activated by a laser engraving beam, the metal complexes in the ink will absorb energy and convert into metal monomers and remain in the ink layer, thereby activating the laser radiation photo area. At the same time, the laser engraving can also roughen the surface to a certain extent, which is beneficial to improve the bonding force between the metal layer (conductive layer 30 ) and the base material layer 10 .

As an optional implementation manner, referring to FIG. 7 , S107 may specifically include:

S1071 : Disposing a metal material on the transition layer 20 to form the first conductive layer 301 .

S1072 : Disposing a metal material on the first conductive layer 301 to form the second conductive layer 302 .

Wherein, the thickness d2 of the first conductive layer 301 may be 1-10um, for example, the thickness d2 of the first conductive layer 301 may be 2um, 3um, 4um, etc., which is not limited in the embodiments of the present application, nor is it limited to the above Example. The thickness d3 of the second conductive layer 302 may also be 1-10um, for example, the thickness d3 of the second conductive layer 302 may be 4um, 6um, 8um, etc., which is not limited in the embodiments of the present application, nor is it limited to the above examples .

Specifically, a thin conductive layer (the first conductive layer 301 ) can be formed on the transition layer 20 by an electroless plating process first, and then a thick conductive layer 301 can be formed on the first conductive layer 301 by an electroless plating process. layer (the second conductive layer 302), when the first conductive layer 301 and the second conductive layer 302 are copper, the electroless copper plating solution may contain copper sulfate, ethylenediaminetetraacetic acid, sodium hydroxide and formaldehyde, wherein , The role of EDTA is to stabilize the concentration of copper ions and prevent the precipitation of copper hydroxide, sodium hydroxide is used to adjust the pH balance, and formaldehyde is used as a reducing agent.

Of course, in some other embodiments, the first conductive layer 301 and the second conductive layer 302 may also be two different metal materials. For example, the first conductive layer 301 may be copper, and the second conductive layer 302 may be silver.

The thickness of the first conductive layer 301 may be smaller than the thickness of the second conductive layer 302 . Of course, in other embodiments, the thickness of the first conductive layer 301 may also be equal to the thickness of the second conductive layer 302 , or the thickness of the first conductive layer 301 may also be greater than the thickness of the second conductive layer 302 . The example is not limited to this.

After S107, referring to FIG. 8, the manufacturing method may further include:

S1081: Provide a second attachment material.

Specifically, the second attachment material may be an inert metal, for example, the second attachment material may be nickel or tin or the like. In the embodiment of the present application, the thickness d4 of the protective layer 40 may be 1-10 um, for example, the thickness d4 of the protective layer 40 may be 4 um, 6 um, 8 um, etc., which is not limited or limited in the embodiment of the present application. Example above.

S1082 : disposing a second adhesion material on the conductive layer 30 , and the second adhesion material forms the protective layer 40 .

In a possible implementation manner, the protective layer 40 may be formed on the conductive layer 30 by an electroless plating process. For example, when the protective layer 40 is nickel, that is, nickel is plated on the conductive layer 30, the electroless nickel plating solution may It contains main salt nickel sulfate (NiS04·7H20), formaldehyde, sulfuric acid solution or sodium hydroxide solution, etc. Among them, formaldehyde is used as a reducing agent, and sulfuric acid solution or sodium hydroxide solution is used to adjust the pH balance.

Hereinafter, the preparation method of the composite substrate will be specifically introduced in combination with different scenarios.

scene one

The base material layer 10 (carbon fiber composite material) is CNC machined according to a specific pattern, and the obtained structure has a CNC machined surface (exposed carbon fiber area) and a non-machined surface (surface is epoxy resin).

In this scenario, the laser-activated ink is first prepared. The components of the laser-activated ink can be 60 parts of polyurethane resin, 30 parts of solvent, 5 parts of metal complex, 3 parts of isocyanate, and 2 parts of other additives, which are mixed in a mixer after stirring. evenly. Then, spray the laser-activated ink on the surface of the base material layer 10 to form the transition layer 20, that is, use a sprayer to spray the laser-activated ink on the surface of the base material layer 10, bake it at 80 degrees for 2 hours, and the cured The thickness of the ink layer is 30um. Next, laser laser engraving activation, that is, using laser to activate the entire or partial area of the transition layer 20 . Next, the metallization treatment is carried out by chemical copper plating treatment for 3 hours, the thickness of the pre-copper (the first conductive layer 301) is 3um, and then the thick copper plating (the second conductive layer 302) is used for chemical plating, and the copper plating treatment is carried out for 5 hours, The thickness of the entire copper layer (conductive layer 30) grows to 7um. Finally, the protective layer 40 is plated, that is, electroless nickel plating is performed for 2 hours to form a nickel film with a thickness of 3 μm.

In this scenario, by spraying a thicker laser-activated ink layer (transition layer 20) on the surface of the substrate layer 10 (carbon fiber composite material), the exposed carbon fibers are covered up, so that the surface of the metal layer and the substrate layer is formed during the metallization process. The adhesion between them is significantly improved, and the surface of the laser-activated ink layer contains bare metal nuclei, which can form strong metal bonds during the electroless plating process. In addition, laser activation is also a way of surface roughening, which can improve adhesion to a certain extent.

scene two

The base material layer 10 (carbon fiber composite material) is CNC machined according to a specific pattern, and the obtained structure has a CNC machined surface (exposed carbon fiber area) and a non-machined surface (surface is epoxy resin).

In this scenario, the laser-activated ink is first prepared. The composition of the laser-activated ink can be 65 parts of epoxy resin, 25 parts of solvent, 8 parts of metal complex, 2 parts of isocyanate, and 1 part of other additives. After stirring in a mixer well mixed. Then, spray the laser-activated ink on the surface of the base material layer 10 to form the transition layer 20, that is, use a sprayer to spray the laser-activated ink on the surface of the base material layer 10, bake it at 80 degrees for 1.5 hours, and the cured The thickness of the ink layer is 20um. Next, laser laser engraving activation, that is, using laser to activate the entire or partial area of the transition layer 20 . Next, for metallization, chemical copper plating is performed for 3 hours, and the pre-copper thickness (first conductive layer 301 ) is 3um, and then chemical copper plating (second conductive layer 302 ) is used for thick copper plating for 7 hours. The thickness of the entire copper layer (conductive layer 30) grows to 10um. Finally, the protective layer 40 is plated, that is, electroless nickel plating is performed for 4 hours to form a nickel film with a thickness of 5 μm.

In this scenario, by spraying a thicker laser-activated ink layer (transition layer 20) on the surface of the substrate layer 10 (carbon fiber composite material), the exposed carbon fibers are covered up, so that the surface of the metal layer and the substrate layer is formed during the metallization process. The adhesion between them is significantly improved, and the surface of the laser-activated ink layer contains bare metal nuclei, which can form strong metal bonds during the electroless plating process. In addition, laser activation is also a way of surface roughening, which can improve adhesion to a certain extent.

In the description of the embodiments of the present application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a The indirect connection through an intermediate medium may be the internal communication of the two elements or the interaction relationship between the two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present application according to specific situations.

The devices or elements referred to in the embodiments of the present application or implied must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present application. In the description of the embodiments of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects, while It is not necessary to describe a particular order or sequence. It is to be understood that the data so used may be interchanged under appropriate circumstances such that the embodiments of the embodiments of the application described herein can be implemented, for example, in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, but not to limit them; It should be understood that: it is still possible to modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the embodiments of the present application The scope of the technical solutions of each embodiment.

Claims (23)

A composite substrate, characterized in that, comprising: a substrate layer, a conductive layer, and a transition layer between the substrate layer and the conductive layer; The base material layer is a carbon fiber composite material, and the conductive layer is a metal material; The transition layer is made of a first adhesion material, and the first adhesion material is used for tightly bonding with the carbon fiber composite material and the metal material respectively. The composite substrate according to claim 1, wherein the carbon fiber composite material comprises a carbon fiber material and a resin material; Wherein, the resin material is thermoplastic resin or thermosetting resin; The resin material is any one of epoxy resin, polyurethane, polyester, nylon, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate, polyoxymethylene, phenolic resin or amino resin or more. The composite substrate according to claim 1 or 2, wherein the first attachment material at least comprises: a resin matrix and a metal complex, the resin matrix is used for tightly bonding with the carbon fiber composite material, and the The metal complex is used for tightly bonding with the metal material. The composite substrate according to claim 3, wherein the resin matrix is epoxy resin, polyurethane, polyester, nylon, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polycarbonate Any one or more of ester, polyoxymethylene, phenolic resin or amino resin. The composite substrate according to claim 3 or 4, wherein the metal complex is copper complex, magnesium complex, palladium complex, iron complex, silver complex, nickel complex Any one or more of complexes or molybdenum complexes. The composite substrate according to any one of claims 1-5, wherein the metal material is any one or more of copper, silver or gold. The composite substrate according to any one of claims 1-6, wherein the thickness of the conductive layer is 1-20um. The composite substrate according to any one of claims 1-6, wherein the conductive layer comprises a first conductive layer and a second conductive layer; The first conductive layer is located between the transition layer and the second conductive layer. The composite substrate according to claim 8, wherein the thickness of the first conductive layer is 1-10um; The thickness of the second conductive layer is 1-10um. The composite substrate according to any one of claims 1-9, wherein the thickness of the transition layer is 10-50um. The composite substrate according to any one of claims 1-10, further comprising: a protective layer; the conductive layer is located between the protective layer and the transition layer. The composite substrate according to claim 11, wherein the protective layer adopts a second adhesion material, and the second adhesion material is an inert metal. The composite substrate according to claim 12, wherein the second attachment material is nickel or tin. The composite substrate according to any one of claims 11-13, wherein the thickness of the protective layer is 1-10um. An electronic device, characterized in that it at least comprises: a middle frame and a back cover; any one or both of the middle frame and the back cover are made of the composite substrate according to any one of the above claims 1-14 production. The electronic device according to claim 15, further comprising: a rotating shaft and a door panel; any one or both of the rotating shaft and the door panel are made of the composite substrate; At least a portion of the shaft is made of the composite substrate. A method for making a composite base material, comprising: Provide at least carbon fiber composite material, metal material and first attachment material; the carbon fiber composite material forms a substrate layer; Disposing the first adhesion material on the base material layer, and the first adhesion material forms a transition layer; disposing the metal material on the transition layer, and the metal material forms a conductive layer; Wherein, the first attachment material is used for tightly bonding with the carbon fiber composite material and the metal material respectively. The method for manufacturing a composite substrate according to claim 17, wherein the first attachment material at least comprises: a resin matrix and a metal complex, and the resin matrix is used for tightly bonding with the carbon fiber composite material, The metal complex is used for tightly bonding with the metal material. The method for manufacturing a composite substrate according to claim 17 or 18, wherein the disposing the first adhesive material on the substrate layer, the first adhesive material forming a transition layer, comprises: The first adhesion material is sprayed on the upper surface of the base material layer by a coating process, and the first adhesion material forms a transition layer. The method for manufacturing a composite substrate according to any one of claims 17-19, wherein the first adhesion material is provided on the substrate layer, and after the first adhesion material forms a transition layer, Also includes: Laser processing is performed on at least part of the transition layer using a laser laser engraving process. The method for manufacturing a composite substrate according to any one of claims 17-20, wherein the disposing the metal material on the transition layer, and the metal material forming a conductive layer, comprises: disposing a metal material on the transition layer to form a first conductive layer; A metal material is disposed on the first conductive layer to form a second conductive layer. The method for manufacturing a composite substrate according to any one of claims 17-21, wherein the disposing the metal material on the transition layer, and after the metal material forms the conductive layer, further comprises: providing a second attachment material; The second adhesion material is disposed on the conductive layer, and the second adhesion material forms a protective layer. The method for manufacturing a composite substrate according to claim 22, wherein the second attachment material is an inert metal.

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