Alloy element with composite coating film and PCB (printed circuit board)

Abstract

The utility model discloses an alloy element with a composite coating film and a PCB (Printed Circuit Board). The alloy element with the composite coating film comprises a metal matrix, and the Ag / Cu-graphene silver infiltration composite coating film is obtained by plating the surface of the metal substrate. The Ag / Cu-graphene silver-infiltrated composite coating film is obtained by plating the surface of a metal matrix, the Ag / Cu-graphene silver-infiltrated composite coating film is physically connected with an external heat source part, silver ions infiltrate between graphene sheet layers, a two-dimensional structure of graphene is changed into a three-dimensional structure, and the surface of the metal matrix is coated with the three-dimensional structure. The problem of poor heat conduction between graphene layers in the prior art is solved, and rapid formation of a coating film is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of PCB circuit boards, and in particular relates to an alloy component with a composite coating and a PCB circuit board. Background Art

[0002] PCB is the abbreviation of Printed Circuit Board, which is a substrate used to support and connect electronic components. PCB is a flat board made of insulating material, on which electronic components are arranged and connected through structures such as conductive tracks, holes and pads; it is one of the most common components in electronic devices, used to build and support electronic circuits.

[0003] Electronic components on PCB circuit boards, such as IGBTs and bridge rectifiers, can convert electrical energy into heat energy. The heat on these electronic components needs to be dissipated through external heat dissipation components to protect the electronic components from damage. The heat dissipation components currently used are made of aluminum alloy or copper alloy. However, whether it is copper alloy or aluminum alloy, the heat transfer efficiency at the contact surface between the electronic components and the heat dissipation components is not high, resulting in poor heat dissipation effect.

[0004] Based on this, patent document 1 (CN116162910A) discloses a silver-graphene composite coating and its preparation method and application, including a first nanosilver layer, a silver-graphene layer and a second nanosilver layer sequentially arranged on a substrate. The thermal conductivity of the silver-graphene composite coating provided by the utility model is ≥330W / m·K; the hardness is ≥80HV; patent document 2 (CN105950904A) discloses a copper-based electrical contact material for medium and low voltage electrical switches. The copper-based composite material of the utility model is composed of the following component ratios: 0.5-4wt% bismuth, 0.05-0.5wt% yttrium, 0.1-0.5wt% graphene (silver-plated), 1-5wt% silver, and the rest is copper and other inevitable impurities. The copper-yttrium alloy powder is prepared and chemically silver-plated, and the powder is ball-milled and mixed with the silver-plated graphene, and finally pressed and sintered to make an electrical contact material.

[0005] Through analysis, it is found that the structure of the above patent cannot solve the problem of heat conduction well and needs further improvement. Summary of the invention

[0006] 1. Problems to be solved

[0007] In view of the above technical problems, the purpose of the utility model is to provide an alloy element with a composite coating to improve the efficiency of heat transfer, thereby achieving faster heat conduction.

[0008] The second purpose of the utility model is to provide a PCB circuit board having the above-mentioned alloy component with a composite coating, which can improve the heat dissipation efficiency of the circuit board and extend the service life of the PCB circuit board.

[0009] 2. Technical solution

[0010] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0011] The first aspect of the utility model provides an alloy element with a composite coating, comprising a metal substrate; and an Ag / Cu-graphene silver-infiltrated composite coating obtained by plating the surface of the metal substrate, wherein the Ag / Cu-graphene silver-infiltrated composite coating is physically connected to an external heat source component.

[0012] According to any implementation scheme of the first aspect of the purpose of the utility model, the film thickness of the Ag / Cu-graphene silver-infiltrated composite coating is greater than 3.0 μm.

[0013] According to any embodiment of the first aspect of the purpose of the utility model, the size of graphene dispersed in the Ag / Cu-graphene silver-infiltrated composite coating is 0.05-6 μm, the content of graphene is 3.0-30 at%, and the orientation of graphene in the Ag / Cu-graphene silver-infiltrated composite coating is at least selected from a metal matrix that is perpendicular, parallel and inclined to the matrix.

[0014] According to any embodiment of the first aspect of the present invention, the material of the metal matrix comprises copper alloy or aluminum alloy.

[0015] According to any implementation scheme of the first aspect of the purpose of the utility model, an intermediate layer is provided between the metal substrate and the Ag / Cu-graphene silver-infiltrated composite coating, and the intermediate layer is located between the metal substrate and the composite coating, and the intermediate layer has the following characteristics: a thickness of 0.01 to 10 μm; the metal of the intermediate layer includes any one or two or more of tin, nickel, and zinc.

[0016] A second aspect of the utility model provides a PCB circuit board, comprising:

[0017] 1) A substrate made of insulating material;

[0018] 2) Used to connect wires between electronic components;

[0019] 3) Connecting vias at different levels;

[0020] 4) Pads used to connect metal areas of electronic component pins;

[0021] 5) electronic components mounted on the substrate;

[0022] 6) A heat dissipation alloy component fixed on the substrate, the heat dissipation alloy component comprising a metal substrate and an Ag / Cu-graphene silver-infiltrated composite coating obtained by plating the surface of the metal substrate, and the electronic component is attached to the Ag / Cu-graphene silver-infiltrated composite coating.

[0023] According to any implementation scheme of the second aspect of the purpose of the utility model, the film thickness of the Ag / Cu-graphene silver-infiltrated composite coating is greater than 3.0 μm.

[0024] According to any embodiment of the second aspect of the present invention, the material of the metal matrix comprises copper alloy or aluminum alloy.

[0025] According to any implementation scheme of the second aspect of the purpose of the utility model, an intermediate layer is provided between the metal substrate and the Ag / Cu-graphene silver-infiltrated composite coating, and the intermediate layer is located between the metal substrate and the composite coating, and the intermediate layer has the following characteristics: a thickness of 0.01 to 10 μm; the metal of the intermediate layer includes any one or two or more of tin, nickel, and zinc.

[0026] 3. Beneficial effects

[0027] Compared with the prior art, the beneficial effects of the utility model are:

[0028] (1) The alloy element with composite coating provided by the utility model is a Ag / Cu-graphene silver-infiltrated composite coating obtained by coating the surface of a metal substrate. Silver ions penetrate between graphene layers, transforming the two-dimensional structure of graphene into a three-dimensional structure. This not only improves the problem of poor thermal conductivity between graphene layers in the prior art, but also facilitates the rapid formation of the coating.

[0029] (2) The alloy element with composite coating provided by the utility model, wherein the film thickness of the Ag / Cu-graphene silver-infiltrated composite coating is greater than 3.0 μm, which not only makes the crystal structure stability of the coating good, but also can effectively improve the thermal conductivity;

[0030] (3) The alloy element with composite coating provided by the utility model also has an intermediate layer between the metal substrate and the coating, especially aluminum alloy. The intermediate layer can prevent the elements of the substrate from diffusing into the Ag / Cu-graphene silver-infiltrated composite coating, and can even out and improve the thickness of the coating, as well as improve the bonding strength between the coating and the metal substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The technical solution of the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for the purpose of explanation and are not intended to limit the scope of the utility model. In addition, unless otherwise specified, these drawings are only intended to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0032] Figure 1 This is a schematic diagram of the PCB circuit board structure of Example 1 of the utility model;

[0033] Figure 2 for Figure 1 A partial enlarged view of

[0034] Figure 3 for Figure 2 sectional view of

[0035] Figure 4 for Figure 2 Another cross-section of:

[0036] Figure 5 :(a) is a SEM image of a coating film with ordinary graphene (abbreviated as Ag-Gr film) of an alloy element provided in the prior art; (b) is a SEM image of a coating film with silver-infiltrated graphene (abbreviated as Ag-Gr (Ag) film) of an alloy element provided in specific embodiment 1-1 of the present utility model;

[0037] Figure 6 The Raman spectroscopic measurement results of the Ag-Graphene composite coating of the prior art and the Ag-Graphene (Ag+) composite coating of the utility model are compared;

[0038] Figure 7 The results of the Ag-Graphene composite coating in the prior art and the Ag-Graphene (Ag+) composite coating of the utility model are compared;

[0039] Description of reference numerals:

[0040] 11. Substrate; 12. Wire; 13. Through hole; 14. Pad; 15. Electronic component; 16. Alloy component; 161. Metal matrix; 162. Ag / Cu-graphene silver-infiltrated composite coating; 163. Intermediate layer. DETAILED DESCRIPTION

[0041] The present disclosure may be more easily understood by reference to the following description in conjunction with the accompanying drawings and examples, all of which constitute a part of the present disclosure. It should be understood that the present disclosure is not limited to the specific products, methods, conditions or parameters described and / or shown herein. Further, the terms used herein are only used for the purpose of describing specific embodiments by way of example and are not intended to be limiting unless otherwise stated.

[0042] It should also be understood that, for the sake of clarity, certain features of the present disclosure may be described herein in the context of separate embodiments, but may also be provided in combination with each other in a single embodiment. That is, unless clearly incompatible or specifically not included, each separate embodiment is considered to be combinable with any other embodiment, and the combination is considered to represent another different embodiment. Conversely, for the sake of simplicity, the various features of the present disclosure described in the context of a single embodiment may also be provided individually or in any sub-combination. Finally, although a particular embodiment may be described as part of a series of steps or part of a more general structure, each step or substructure itself may also be considered to be an independent embodiment.

[0043] Unless otherwise indicated, it should be understood that each individual element in a list and each combination of individual elements in the list will be interpreted as a different embodiment. For example, a list of embodiments represented as "A, B, or C" should be interpreted to include embodiments "A", "B", "C", "A or B", "A or C", "B or C", or "A, B, or C".

[0044] In the present disclosure, the singular forms of the articles "a," "an," and "the" also include the corresponding plural references, and a reference to a specific value includes at least that specific value unless the context clearly indicates otherwise. Thus, for example, a reference to "a substance" is a reference to at least one of that substance and equivalents thereof.

[0045] The terms including ordinal numbers such as "first" and "second" can be used to explain various components or fluids, but these components and fluids are not limited by these terms. Therefore, without departing from the teachings of the present disclosure, these terms are only used to distinguish the component / fluid from another component / fluid.

[0046] When items are described by using the conjunction terms "... and / or...," etc., the description should be understood to include any one of the associated listed items and all combinations of one or more thereof.

[0047] In general, the use of the term "about" indicates an approximate value that may vary depending on the desired properties obtained by the disclosed subject matter, and will be interpreted in a context-dependent manner based on function. Therefore, one of ordinary skill in the art will be able to interpret a certain degree of difference on a case-by-case basis. In some cases, the number of significant figures used when expressing a particular value can be a representative technique for determining the difference allowed by the term "about". In other cases, a gradient in a range of values ​​can be used to determine the range of differences allowed by the term "about". Further, all ranges in this disclosure are inclusive and combinable, and reference to the values ​​stated in the range includes each value within the range.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs; the terms used herein and / or include any and all combinations of one or more related listed items.

[0049] The "composite coating" provided by the utility model mainly uses silver and graphene as main components (Ag / Cu-graphene silver-infiltrated composite coating).

[0050] The “coating” described herein may also be referred to as a “plating” or a “contact coating”.

[0051] The "metal material / component with composite coating" provided by the utility model mainly comprises a metal substrate and the "composite coating" as described above;

[0052] The "metal substrate" mentioned here is mainly considered to have excellent thermal conductivity, electrical conductivity and machinability, and other properties are not particularly limited. Examples thereof include copper alloys, aluminum alloys, and the like.

[0053] Based on the above, examples of "metal materials / components with composite coatings" provided by the present invention include:

[0054] a) A metal is used as a substrate, and a Ag / Cu-graphene silver-infiltrated composite coating is provided on the surface of the substrate.

[0055] The "composite coating" of the "alloy element with composite coating" provided in the present invention generally satisfies any one or more of the following conditions:

[0056] 1) The film thickness of the Ag / Cu-graphene silver-infiltrated composite coating is greater than 3.0 μm.

[0057] 2) The size of graphene dispersed in the Ag / Cu-graphene silver-infiltrated composite coating is 0.05-6 μm, the content of graphene is 3.0-30 at%, and the orientation of graphene in the Ag / Cu-graphene silver-infiltrated composite coating is at least selected from a metal matrix that is perpendicular, parallel and inclined to the matrix.

[0058] The silver between the graphene sheets will increase the interlayer bonding force of the graphene sheets, and the interlayer bonding force of the graphene sheets will be further increased as the silver content increases, but it should be noted that too much silver will cause serious agglomeration of the graphene and make it unusable; therefore, in some embodiments of the utility model, according to the atoms of the "graphene infiltrated with silver" as the total number, the amount of silver between the graphene sheets is 0.01-100at%, and in some preferred embodiments of the utility model, according to the atomic percentage of the "graphene", the amount of silver between the graphene sheets is 0.1-45at%. It is further explained that the silver content in the "graphene infiltrated with silver" is in the value range of 0.01-100at%, and the conductivity trend line of the "composite coating" is obtained by fitting the experimental data, and the trend line changes basically linearly. In the following embodiments, the "graphene infiltrated with silver" with a silver content of 5at% is used to schematically illustrate the technical solution of the utility model.

[0059] The “composite coating” as described above is formed on the “metal substrate” by the method of “electroplating”, and the “electroplating” includes the following steps 1) and 2) :

[0060] 1) Prepare the plating solution and substrate

[0061] The plating solution includes components for forming a coating; for example, if the coating is a "coating", then the "components for forming a coating" at least include "graphene infiltrated with silver";

[0062] 2) Electroplating the substrate using the plating solution. The detailed operation of the electroplating for reference is as follows:

[0063] The plating solution is supplied approximately perpendicularly to the surface to be plated of the substrate, and convects approximately horizontally on the surface to be plated, or flows approximately horizontally on the surface to be plated; the process includes electroplating the metal substrate with the plating solution, wherein the plating solution is an industrial plating solution containing or not containing cyanide, preferably a plating solution not containing cyanide. The current density during electroplating can be between 0.1A / dm 2 ~100A / dm 2 The thickness of the "plating film" can be adjusted within a range of , and the thickness of the "plating film" can be adjusted by adjusting the current density and time. For example, when the current density is constant, the thickness of the obtained "plating film" can be increased by extending the electroplating time.

[0064] On the basis of the aforementioned "electroplating" steps 1) and 2), the preparation of the "plating" is further described in detail as an illustrative example:

[0065] During the electroplating process, the "graphene infiltrated with silver" contained in the plating solution (i.e., the plating solution) may contain other metals besides silver. Wherein, the "graphene infiltrated with silver" also has a layered structure formed by stacked graphene sheets, and there are gaps between the layers, and the gaps form an effective space inside the graphene. The "silver between the graphene sheets" can be understood as silver ions and / or nanosilver particles filled / dispersed in the effective space. Generally, silver ions and nanosilver particles (also called particles) exist at the same time. The "filling / dispersion" can be a small amount of local filling, or a large part of the filling, or all of the filling. Based on this, the "graphene infiltrated with silver" includes a body composed of stacked graphene sheets, and silver ions and / or nanosilver particles located between the graphene sheets. Wherein, the silver ions and nanosilver particles existing between the graphene sheets can accelerate the movement speed of the "graphene infiltrated with silver" under the electric field, thereby facilitating the rapid formation of the coating, and is particularly suitable for local small-scale electroplating and high-speed electroplating of the substrate.

[0066] Regarding the body of the "laminated graphene sheet" constituting the "silver-infiltrated graphene" used in the electroplating process, it is preferably a sheet-shaped or laminated graphene with a size of 6 μm or less; in some preferred embodiments of the present invention, it mainly refers to a sheet-shaped or laminated graphene with a size of 0.01 to 6 μm or less; in further preferred embodiments of the present invention, it mainly refers to a sheet-shaped or laminated graphene with a size of 0.01 to 5 μm or less;

[0067] Regarding the preparation method of the body of the "laminated graphene sheet" of the "silver-infiltrated graphene" used in the electroplating process, it can be carried out by electrolytic stripping as shown below, and the specific electrolytic stripping conditions that can be referred to are as follows: immersing graphite in an aqueous solution and decomposing the graphite into layers through a strong electric field and an electrochemical reaction. The decomposed layered graphene is classified into the following graphene sizes. The graphene size is a mixture of 1 μm or less, 1 to 3 μm, 3 to 5 μm, and 6 μm or less. In addition, the size of the graphene is classified according to the mesh size of the filter paper used for filtration.

[0068] Regarding the "graphene infiltrated with silver" used in the electroplating process, it can be obtained by commercial means, or by methods such as self-assembly, chemical reduction, hydrothermal, electrochemical deposition, and thermal evaporation. For example, the self-assembly method is to mix the graphene dispersion with pre-prepared or commercially available silver nanopowder or silver ion solution, and combine it through covalent bonds or non-covalent bonds (van der Waals forces, electrostatic forces, intermolecular forces, and hydrogen bonds, etc.) to obtain "graphene infiltrated with silver". Based on, the self-assembly method can prepare a graphene nanocomposite material with a simple and controllable silver loading and a highly uniform distribution. Therefore, in the actual preparation process, functionalized graphene can be first used as a raw material, modified with n-octadecyl mercaptan, then added to an ethanol solution, ultrasonically dispersed, silver chloride is added, and a composite material is prepared by photochemical reduction. The interaction between n-octadecyl mercaptan molecules and silver can effectively control the arrangement and orientation of silver on the graphene surface, so that it generates specific nano-Ag particles, thereby controlling the preparation of graphene / silver nanocomposite materials, which can be used as "graphene infiltrated with silver" in the electroplating process of the utility model. Alternatively, it can be obtained by "chemical reduction method", which is the most common method for preparing graphene / silver nanocomposite materials. The process is to configure graphene and silver into graphene solution and silver chloride solution, mix the two, add corresponding reducing agents, and prepare graphene / metal silver nanocomposite materials by oxidation-reduction method. The obtained graphene / metal silver nanocomposite materials can be used as "graphene infiltrated with silver" in the electroplating process of the utility model. Alternatively, it can be obtained through "electrochemical deposition method", which is a highly efficient preparation method. By electrochemical deposition method, graphene sheets are directly dispersed into a silver-containing electroplating solution, and a surfactant is added and stirred to obtain a graphene / silver nanocomposite material. The graphene / silver nanocomposite material can be used as the "silver-infiltrated graphene" in the electroplating process of the utility model.

[0069] The orientation of the "laminated graphene sheets" in the "coating one" provided by the utility model is not specially set, and can be arranged perpendicularly, parallel, inclined or arbitrarily randomly with respect to the substrate according to the required characteristics of the component.

[0070] The detection instruments (or models) and conditions used in the following specific embodiments are:

[0071] Surface morphology: The surface states of various target objects were investigated by field effect scanning electron microscopy (FE-SEM) (JEOL-JSM_7800F, 5 kV,).

[0072] Chemical composition analysis: The chemical composition of various target objects was measured by energy dispersive spectroscopy (EDS) installed on FE-SEM (measurement range 1000 times, measurement voltage 20 kV).

[0073] Raman Detection: The binding state of various target objects was studied by Raman spectroscopy (machine name: laser Raman spectrophotometer (NRS-3300), the measurement light wave range is 254.896cm -1 ~3899.87cm -1 , center wave number: 2301.01cm -1 , excitation wavelength: 532.08nm, laser intensity: 7.9mW).

[0074] XRD measurement: The crystal state and crystal plane orientation state of various target objects were studied by XRD measurement (machine name: powder X-ray diffraction measurement device, RINT-2000, 40kV / 30mA, Cu / Ka).

[0075] Elemental analysis: Elemental analysis in the depth direction was investigated by glow discharge optical emission (GD-OES) measurement (machine name: glow discharge optical emission profiler (HORIBA-GD-profiler 2-MN), measurement area: diameter 8 mm, flowing gas: nitrogen).

[0076] Example series one

[0077] like Figures 1 to 3 As shown, the alloy component with composite coating in this embodiment is a heat sink, especially a copper alloy heat sink used in LED lamp PCB circuit board, because copper alloy has high thermal conductivity and high strength. In addition, as long as it is a thermally conductive metal material, aluminum alloy can also be used as a heat sink.

[0078] Combination Figure 1 The PCB circuit board shown includes:

[0079] 1) A substrate 11 made of an insulating material, wherein the insulating material includes glass fiber reinforced epoxy resin (FR-4), which provides mechanical strength and a supporting structure while having good insulating properties;

[0080] 2) The wire 12 used to connect the electronic components is made of copper foil and formed by etching or adding electroplating. The width, spacing and level of the wire can be adjusted according to the circuit design requirements;

[0081] 3) Connecting through holes 13 at different levels, through the holes, the signal, power and ground pins can be led out from one layer of wires and connected to the wires at other levels, thus realizing the connection of multi-layer circuits;

[0082] 4) pads 14 for connecting the metal areas of the electronic components 15;

[0083] 5) The electronic components 15 mounted on the substrate 11, such as IGBT, rectifier bridge stack, etc., are connected to the wires and pads by welding or insertion;

[0084] 6) a heat dissipation alloy element 16 fixed on the substrate, the heat dissipation alloy element 16 comprising a metal substrate 161 and a Ag / Cu-graphene silver-infiltrated composite coating 162 obtained by coating the surface of the metal substrate 161, the electronic component 15 is attached to the Ag / Cu-graphene silver-infiltrated composite coating 162 to achieve a physical connection; the film thickness of the Ag / Cu-graphene silver-infiltrated composite coating 162 is greater than 3.0 μm, and the electronic component 15 is attached to the Ag / Cu-graphene silver-infiltrated composite coating 162 to achieve a physical connection; ... electronic component 15 is attached to the Ag / Cu-graphene silver Figure 5 It can be seen that the structure of this embodiment is greatly different from the prior art.

[0085] As a pretreatment of the copper alloy substrate, alkaline electrolytic degreasing and pickling are performed, but the treatment conditions are not particularly limited; on the other hand, electrolytic exfoliation is performed as follows. The layered graphene nanosheets are made by immersing graphite in an aqueous solution and decomposing the graphite into layers through a strong electric field and an electrochemical reaction. In addition, depending on the crystal state of the graphite as a raw material, the thickness of the electrolytically exfoliated graphene is about 6 μm or less.

[0086] The graphene was fractionated by filtration using filters with pore sizes of 5 μm, 3 μm, and 1 μm, respectively. In addition, all operations were performed in an aqueous solution, and the obtained graphene was not oxidized but became reduced graphene.

[0087] Various Cu alloy substrates (Cu-Ni-Si, Cu-Be, Cu-Zn, Cu-Te, Cu-Sn, Cu-TC) were used as starting materials, and electrolytic degreasing and pickling were performed as pretreatment. Graphene was produced by electrolytic stripping of graphite; the Ag plating solution used was a commercially available cyanide-free Ag plating solution.

[0088] In addition, Graphene-Ag+ (Gr-Ag+) in which Ag+ was dispersed in Graphene was used as a base liquid for comparison (Ag+) and Graphene (Gr) that was not dispersed was prepared, and a composite coating was created using a hybrid electroplating method.

[0089] The coating includes metallic silver and graphene infiltrated with silver. More detailed information is as follows:

[0090] 1) About the plating solution used

[0091] Basic electroplating solution: A commercially available cyanide-free silver plating solution of Tanaka Precious Metals Co., Ltd. (model PRECIOUSFAB Ag4730, Ag concentration 30 g / L, as the basic electroplating solution, reference website https: / / www.tanaka.com.cn / products / detail / plating-processes / ) was used.

[0092] Electroplating solution containing "silver-infiltrated graphene": On the basis of the basic electroplating solution, "silver-infiltrated graphene (hereinafter referred to as silver-infiltrated graphene)" with a silver content of 5at% is added thereto. The size of the graphene sheets of the silver-infiltrated graphene used here is 0.05-6μm. In view of the need to reduce costs as much as possible in practical applications, the utility model uses mixed-size graphene sheets without graded separation, wherein the particle size distribution of graphene sheets below 5μm, 3μm and 1μm accounts for approximately 30%, 35% and 30% respectively). Finally, the silver-infiltrated graphene is calculated by the weight of carbon, and according to the aqueous solution, the concentration of the silver-infiltrated graphene in this electroplating solution is 100g / L (equivalent to a concentration of approximately 9.6wt%).

[0093] 2) Regarding the conditions for electroplating

[0094] The current density is controlled at 0.1A / dm 2 ~10A / dm 2 ;

[0095] The bath temperature was fixed at 50°C;

[0096] During the electroplating process, magnetic stirring at 500 rpm was used.

[0097] The thickness of the coating can be adjusted by combining the electroplating time and the current density to ensure that the coating of the target thickness is finally obtained. In this embodiment, coatings with thicknesses of 0.3 μm, 1 μm, 3 μm, and 5 μm are prepared by adjusting the electroplating time.

[0098] In addition, before electroplating, the surface of the base material needs to be subjected to alkaline electrolytic degreasing to remove oil stains and the anti-discoloration film on the copper, and then pickled to remove the oxide film on the surface, as shown in Table 1, a specific embodiment of the first embodiment of this embodiment series.

[0099] Table 1. Basic information of the specific embodiments of the first embodiment of this embodiment series

[0100] Specific embodiments Coating Type <![CDATA[Current density A / dm 2 > Coating thickness μm XRD main crystal direction Base material 1-1 Ag-Gr(Ag) 1 5 220 Cu-Ni-Si 1-2 Ag-Gr(Ag) 1 3 220 Cu-Ni-Si 1-3 Ag-Gr(Ag) 1 1 111 Cu-Ni-Si 1-4 Ag-Gr(Ag) 1 0.5 111 Cu-Ni-Si 1-5 Ag-Gr(Ag) 1 0.3 111 Cu(TC) 1-6 Ag-Gr(Ag) 0.5 5 Cu-Ni-Si 1-7 Ag-Gr(Ag) 1.5 5 Cu-Ni-Si 1-8 Ag-Gr(Ag) 2 5 Cu-Ni-Si 1-9 Cyan-Ag-Gr(Ag) 1 5 Cu-Sn-P 1-10 Ag-Gr(Ag) 1 5 220 Cu(TC) 1-11 Ag-Gr(Ag) 1 5 220 Cu-Be-Ni 1-12 Ag-Gr(Ag) 1 5 — Cu-Zn 1-14 Ag-Gr(Ag) 1 3 220 Cu-Ni-Si 1-15 Ag-Gr(Ag) 1 5 Cu-Ni-Si 1-16 Ag-Gr(Ag) 1 5 Pure-Cu

[0101] Note that the total number of atoms in the coating is calculated based on the carbon content:

[0102] Coating type Ag-Gr (Ag), current density 0.5A / dm2 When , the content of silver-infiltrated graphene in the coating obtained in the embodiment is 12at%;

[0103] Coating type Ag-Gr (Ag), current density 1A / dm 2 When , the content of silver-infiltrated graphene in the coating obtained in the embodiment is 11 at %;

[0104] Coating type Ag-Gr (Ag), current density 2A / dm 2 When , the content of silver-infiltrated graphene in the coating obtained in the embodiment is 10at%;

[0105] Coating type Ag-Gr (Ag), current density 4~8A / dm 2 When , the content of silver-infiltrated graphene in the coating obtained in the embodiment is 8at%;

[0106] Coating type Cyan-Ag-Gr-Ag, current density 1A / dm 2 When the content of silver-infiltrated graphene in the coating obtained in the embodiment is 12 at %.

[0107] Figure 6 a shows the Raman spectrometry results of Ag-Graphene composite coatings and Ag-Graphene (Ag+) composite coatings prepared by electroplating on Cu-Ni-Si copper alloy. In either coating, D-band, G-band and 2D-band belonging to Graphene were detected, indicating that the coating can be composited with Graphene.

[0108] Ag-Graphene (Ag+) composite coating is 500cm -1 A peak due to the binding between Ag and graphene was also confirmed nearby. Analysis showed that the addition of Ag ions promoted the binding between Ag and C in the graphene sheet. Figure 6 b It is also confirmed that the peak of graphene exists even when the film thickness is 0.3 μm, so the composite is confirmed even when the film thickness is 0.3 μm. 500 cm in both cases -1 Since the nearby peaks can be confirmed, the combination of Ag and graphene is an effective means for Ag+ to be considered as graphene generation.

[0109] In fact, the graphene used in the preparation of the coating provided by the utility model is pre-processed graphene, and the processing includes: using a solution containing silver ions for dispersion treatment. This is also the reason why the Raman spectrum of the coating has a value of 500±30cm -1One of the key reasons for the peak. The bonding force between graphene layers is the van der Waals force, and the carbon atoms within the layer are bonded by covalent bonds. Therefore, compared with the thermal conductivity within the layer, the thermal conductivity between layers is poor. Finally, the coating provided by the utility model is "infiltrated" with silver ions between the stacked graphene sheets and sheets, and based on this, the two-dimensional structure can be converted into a three-dimensional structure, which not only improves the problem of poor thermal conductivity between graphene layers in the prior art, but also facilitates the rapid formation of the coating, and is particularly suitable for local small-scale electroplating and high-speed electroplating of metal substrates.

[0110] Figure 7 a shows the AgGraphene composite coating and Ag-Graphene (Ag+) composite coating prepared on Cu-Ni-Si alloy substrate. Figure 7 b is the crystal structure results of Ag-Graphene (Ag+) made on Cu-Ni-Si alloy substrate measured by XRD with composite coating thickness of 1μm and 3μm.

[0111] First, if Figure 7 The preferred orientation of Ag in the composite coating shown in a is (111) in the Ag-Graphene composite coating, while Ag-Graphene (Ag+) is (220) in the composite coating. Studies have shown that the heat resistance test of the Ag-Graphene composite coating shows that the preferred orientation of the crystal structure is transferred from (111) to (220). Therefore, in the Ag-Graphene composite coating, the AgGraphene (Ag+) with a preferred orientation toward (220) can make the composite coating stable in terms of crystal structure.

[0112] In addition, according to Figure 7 b, the inventor surprisingly found that when the film thickness is 1 μm, the preferred orientation is toward the (111) direction, while when it is 3 μm, the preferred orientation moves toward the (220) direction. Therefore, from the perspective of crystal structure stability, the film thickness should be no less than 3 μm, thereby effectively improving the thermal conductivity of the alloy component. Compared with patent document 1, the thermal conductivity and hardness are improved.

[0113] Example series 2

[0114] 1) About the substrate used

[0115] As shown in Table 2 below, various aluminum and aluminum alloy materials are used as the metal matrix:

[0116] Table 2. Basic information of each aluminum matrix

[0117]

[0118] As described in Table 1, the copper content of the main alloying element of the Al-Cu alloy may be between 3 and 5 wt%, such as 3.5 to 4.5 wt%, and the aluminum content is about 90 wt%, excluding other inevitable impurities;

[0119] As described in Table 1, the Al-Si alloy has a silicon content of 0.3-0.7 wt %, a magnesium content of 0.45-0.9 wt % and an aluminum content of 97 wt % as the main alloying element; other inevitable impurities are not counted.

[0120] 2) Regarding the intermediate coating

[0121] In this embodiment, an intermediate coating mainly composed of metal Ni is prepared on the surface of the aluminum alloy metal substrate by electroplating (the "intermediate coating" can also be called an intermediate layer, a transition layer, a transition film, or an anti-diffusion layer). There is no special requirement for its thickness, which can be tens of nanometers and several microns. Here, a Ni intermediate coating with a thickness of 30nm and 3μm is mainly prepared, and then a 5μm thick Ag-Gr (Ag) coating is prepared on the Ni intermediate coating, which are respectively recorded as Ni-03 / Ag-Gr (Ag) and Ni-3 / Ag-Gr (Ag) coatings.

[0122] The "intermediate layer" described in the utility model is mainly a "metal intermediate coating", one of the main functions of which is diffusion prevention; the second main function is to improve the bonding force between the "composite coating" and the "substrate"; the third main function is to reduce the induced influence of the "substrate" on the crystal structure of the "composite coating" and improve the all-plating ability of the coating. Therefore, in this case, the "metal intermediate coating" can prevent the elements on the metal surface of the "substrate" in contact (such as copper / copper alloy, aluminum / aluminum alloy, etc.) from entering the "composite coating" or diffusing to the surface of the "composite coating" under high temperature environment to form an oxide film, and at the same time can enhance the bonding strength between the "substrate" and the "composite coating" and improve the uniformity of the "composite coating". Especially when it comes to the situation where the metal surface of the "substrate" is easy to produce a stable metal oxide film, such as the surface of the connecting part of the "substrate" is a copper alloy, aluminum alloy, etc., which is easy to passivate metal surface.

[0123] 3) About the plating solution used

[0124] The basic electroplating solution is the same as the basic electroplating solution of Example Series 1;

[0125] The electroplating solution containing “silver-infiltrated graphene” is the same as the electroplating solution containing “silver-infiltrated graphene” in the first embodiment.

[0126] 4) Regarding the conditions for electroplating

[0127] The current density is controlled at 1A / dm 2 ;

[0128] The bath temperature was fixed at 50°C;

[0129] By adjusting the electroplating time, a 5 μm thick Ag-Gr (Ag) coating was prepared (calculated according to the carbon atomic percentage, the content of silver-infiltrated graphene in the coating was 12 at%).

[0130] The rest of the electroplating conditions are the same as those in Example 1.

[0131] Based on the above, the specific embodiments of electroplating Ag-Gr (Ag) film on aluminum alloy substrate provided in this series of embodiments are listed in Table 3:

[0132] Table 3. Basic description of the specific embodiments of the second embodiment

[0133]

[0134]

[0135] In the table, "Carbon content at%" means the content of the silver-infiltrated graphene / graphene calculated by carbon content based on the total number of atoms of the coating;

[0136] “--” indicates that there is no corresponding membrane structure;

[0137] "Ni-03" means a 0.03μm thick intermediate coating mainly composed of metallic Ni;

[0138] “Ni-3” means a 3μm thick intermediate coating mainly composed of metallic Ni;

[0139] Hereinafter, “Ni-3 / Ag-Gr(Ag) film” means the superposition of a 3 μm thick intermediate coating film mainly composed of metal Ni and an Ag-Gr(Ag) film;

[0140] Hereinafter, "Ni-03 / Ag-Gr(Ag) film" means the superposition of a 0.03 μm thick intermediate plating film mainly composed of metal Ni and an Ag-Gr(Ag) film.

[0141] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

Claims

1. An alloy component (16) with a composite coating, comprising a metal substrate (161); characterized in that: And an Ag / Cu-graphene silver-infiltrated composite coating (162) obtained by coating the surface of the metal substrate (161), wherein the Ag / Cu-graphene silver-infiltrated composite coating (162) is physically connected to an external heat source component.

2. The alloy element with composite coating according to claim 1, characterized in that: The Ag / Cu-graphene silver-infiltrated composite plating film (162) has a film thickness of more than 3.0 μm.

3. The alloy element with composite coating according to claim 1 or 2, characterized in that: The material of the metal matrix (161) includes copper alloy or aluminum alloy.

4. The alloy element with composite coating according to claim 3, characterized in that: An intermediate layer (163) is provided between the metal substrate (161) and the Ag / Cu-graphene silver-infiltrated composite coating (162), and the intermediate layer (163) has the following characteristics: Thickness of 0.01 to 10 μm.

5. The alloy element with composite coating according to claim 4, characterized in that: The metal of the intermediate layer (163) includes any one of tin, nickel and zinc.

6. A PCB circuit board, comprising: A substrate (11) made of insulating material; A wire (12) for connecting electronic components; connecting through holes (13) at different levels; Solder pads (14) for connecting metal areas of electronic component pins; an electronic component (15) mounted on the substrate; A heat dissipation alloy component (16) fixed on the substrate; characterized in that the heat dissipation alloy component (16) comprises a metal substrate (161) and an Ag / Cu-graphene silver-infiltrated composite coating (162) obtained by coating the surface of the metal substrate (161), and the electronic component (15) is attached to the Ag / Cu-graphene silver-infiltrated composite coating (162).

7. The PCB circuit board according to claim 6, characterized in that: The Ag / Cu-graphene silver-infiltrated composite plating film (162) has a film thickness of more than 3.0 μm.

8. The PCB circuit board according to claim 6 or 7, characterized in that: The material of the metal matrix (161) includes copper alloy or aluminum alloy.

9. The PCB circuit board according to claim 8, characterized in that: An intermediate layer (163) is provided between the metal substrate (161) and the Ag / Cu-graphene silver-infiltrated composite coating (162), the intermediate layer (163) being located between the metal substrate (161) and the composite coating (162), and the intermediate layer (163) has the following characteristics: Thickness of 0.01 to 10 μm.

10. The PCB circuit board according to claim 9, characterized in that: The metal of the intermediate layer (163) includes any one of tin, nickel and zinc.

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