Printed circuit board and preparation method thereof

Abstract

The invention discloses a printed circuit board and a preparation method thereof, and the method comprises the steps: obtaining a processing plate, and laminating a metal layer on one side of the processing plate; depositing a graphene layer on one side, far away from the processing plate, of the metal layer so as to be combined with the metal layer to form a conductive layer; and preparing the printed circuit board based on the conductive layer. In this way, the wiring design and the heat dissipation efficiency of the conductive circuit can be both considered.

Description

Technical Field

[0001] The invention is applied to the technical field of printed circuit boards, in particular to a printed circuit board and a preparation method thereof. Background Art

[0002] PCB (Printed Circuit Board), also known as printed circuit board or printed circuit board, is an important electronic component with wide applications. It is the support body of electronic components and also the carrier of electrical connection of electronic components.

[0003] When designing high-density lines, the internal resistance of the lines is difficult to control and they are prone to heat generation, so additional heat dissipation solutions need to be configured.

[0004] However, when the printed circuit board needs to dissipate heat, it needs to be designed as thick copper or a separately embedded metal base. The thick copper design limits the layout of fine circuits and is not conducive to lightweight, while the embedded metal base design is not conducive to lightweight and occupies wiring space. Summary of the invention

[0005] The present invention provides a printed circuit board and a preparation method thereof, so as to solve the problem of balancing the heat dissipation, wiring space and lightness of the printed circuit board.

[0006] In order to solve the above technical problems, the present invention provides a method for preparing a printed circuit board, comprising: obtaining a processing board, one side of the processing board is stacked with a metal layer; depositing a graphene layer on the side of the metal layer away from the processing board to combine with the metal layer to form a conductive layer; and preparing a printed circuit board based on the conductive layer.

[0007] Among them, the step of depositing a graphene layer on the side of the metal layer away from the processing plate to combine with the metal layer to form a conductive layer includes: placing a jig plate on the side of the metal layer away from the processing plate; wherein a hollow area is provided on the jig plate based on the shape of the conductive circuit of the conductive layer; graphene is deposited on the side of the metal layer away from the processing plate to form a graphene layer in the hollow area; wherein the graphene layer has the shape of the conductive circuit of the conductive layer; removing the jig plate and the exposed metal layer to obtain a conductive layer formed with a conductive circuit.

[0008] Among them, the step of depositing graphene on the side of the metal layer away from the processing plate to form a graphene layer in the hollow area includes: using chemical vapor deposition technology, in an atmosphere of a carbon source and a carrier gas, heating the side of the metal layer away from the processing plate to cause a deposition reaction to generate carbon atoms to form a graphene layer; or forming a carbon source in the hollow area and forming a graphene layer by thermal decomposition of hydrocarbon gases.

[0009] Among them, the steps of removing the jig plate and the exposed metal layer to obtain a conductive layer formed with a conductive circuit include: removing the jig plate, and removing the metal layer not covered by the graphene layer by water jet or laser cutting to obtain a metal layer in the shape of a conductive circuit; combining the metal layer and the graphene layer to obtain a conductive layer.

[0010] Among them, the steps of preparing a printed circuit board based on the conductive layer include: laminating a dielectric layer and a build-up metal layer on the side of the conductive layer away from the processed board; connecting the build-up metal layer and the conductive layer to obtain a printed circuit board.

[0011] Wherein, the processed board includes: a built-up board or a carrier board; when the processed board is a carrier board, after the step of laminating the dielectric layer and the built-up metal layer on the side of the conductive layer away from the processed board, it includes: removing the carrier board.

[0012] Among them, the step of connecting the build-up metal layer and the conductive layer includes: drilling from the side of the build-up metal layer away from the metal layer until a plurality of blind holes exposing the metal layer are formed; electroplating the side of the build-up metal layer away from the metal layer until all the blind holes are filled to form a metallized hole connecting the build-up metal layer and the conductive layer.

[0013] Among them, the step of connecting the build-up metal layer and the conductive layer to obtain a printed circuit board also includes: etching the build-up metal layer to form a corresponding conductive circuit to obtain a printed circuit board; or connecting the build-up metal layer and the conductive layer to obtain a built-up board, and using the built-up board as a new processed board; repeatedly performing the step of depositing a graphene layer on the side of the metal layer away from the processed board to combine with the metal layer to form a conductive layer; and preparing a printed circuit board based on the conductive layer, until the built-up board meets the preset requirements to obtain a printed circuit board.

[0014] To solve the above technical problems, the present invention provides a printed circuit board prepared by any of the above printed circuit board preparation methods, comprising: a conductive layer, the conductive layer comprising a metal layer and a graphene layer stacked and bonded in sequence.

[0015] The thickness of the metal layer ranges from at least 1.5 micrometers; the thickness of the graphene layer ranges from 0.3 nanometers to 25000 nanometers.

[0016] In order to solve the above technical problems, the preparation method of the printed circuit board of the present invention obtains a processing plate, and a metal layer is stacked on one side of the processing plate; a graphene layer is deposited on the side of the metal layer away from the processing plate to form a conductive layer in combination with the metal layer; a printed circuit board is prepared based on the conductive layer, and a conductive layer is formed based on the stacked metal layer and the graphene layer. Graphene is used to improve the heat dissipation efficiency of the printed circuit board, and the graphene layer is covered on the corresponding metal layer, which will not increase the occupied space of the graphene layer too much, ensuring the wiring design of the conductive circuit, and can greatly increase the heat dissipation area of ​​the conductive layer, further improve the heat dissipation efficiency, and achieve a balance between heat dissipation, wiring space and lightweight. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic flow chart of an embodiment of a method for preparing a printed circuit board provided by the present invention;

[0018] Figure 2 It is a schematic flow chart of another embodiment of the method for preparing a printed circuit board provided by the present invention;

[0019] Figure 3 for Figure 2 A schematic diagram of the structure of the preparation process of a printed circuit board;

[0020] Figure 4 is a top view of a structure of a jig plate in one embodiment;

[0021] Figure 5 is a schematic diagram of a top view structure of an embodiment of a graphene layer;

[0022] Figure 6 It is a schematic diagram of the structure of the added-layer panel after adding more layers;

[0023] Figure 7 It is a schematic structural diagram of an embodiment of a printed circuit board. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] See also Figure 1 , Figure 1 The figure is a flow chart of an embodiment of a method for preparing a printed circuit board provided by the present invention.

[0028] Step S11: Obtain a processed plate, one side of which is laminated with a metal layer.

[0029] The processed board is a board on which a conductive layer needs to be provided, and the conductive layer can be the first conductive layer, any intermediate conductive layer or the last conductive layer in the entire printed circuit board.

[0030] Based on the position of the conductive layer, the processed plate may be a carrier plate or a plate with added layers in the intermediate preparation process. The specific setting is based on actual needs and is not limited here.

[0031] A metal layer is laminated on one side of the processed plate, and the metal layer includes but is not limited to a copper layer, an aluminum layer, a silver layer, a nickel layer or an alloy layer, etc., which is specifically set based on actual needs and is not limited here. The metal layer is used to form a part of the conductive layer.

[0032] Step S12: depositing a graphene layer on a side of the metal layer away from the processing plate to combine with the metal layer to form a conductive layer.

[0033] Graphene is a sp 2A material in which hybrid-connected carbon atoms are tightly packed into a single-layer two-dimensional honeycomb lattice structure. The arrangement of carbon atoms inside graphene is the same as that of graphite monoatomic layers, with sp2 hybrid orbitals forming bonds, and has the following characteristics: carbon atoms have 4 valence electrons, 3 of which form sp2 bonds, that is, each carbon atom contributes an unbonded electron located in the pz orbital, and the pz orbital of the neighboring atom is perpendicular to the plane to form a π bond, and the newly formed π bond is half-filled. Studies have confirmed that the coordination number of carbon atoms in graphene is 3, the bond length between each two adjacent carbon atoms is 1.42×10-10 meters, and the angle between bonds is 120°. In addition to the σ bond that links other carbon atoms to form a hexagonal ring honeycomb layered structure, the pz orbital of each carbon atom perpendicular to the layer plane can form a large multi-atomic π bond that runs through the entire layer, thus having excellent electrical, thermal and optical properties.

[0034] Therefore, by combining the metal layer and the graphene layer as the conductive layer, the conductive function of the layer can be realized, and the graphene layer can be used for heat dissipation. The graphene layer covers the metal layer, which does not increase the occupied space of the graphene layer too much, ensuring the wiring design of the conductive line, and can greatly increase the heat dissipation area of ​​the conductive layer, further improving the heat dissipation efficiency, thereby reducing the internal resistance of the conductive layer. And by arranging the graphene layer on the metal layer by deposition, the bonding force between the graphene layer and the metal layer can be improved, thereby improving the structural stability of the conductive layer.

[0035] Step S13: preparing a printed circuit board based on the conductive layer.

[0036] In a specific application scenario, when the conductive layer is the first conductive layer or any intermediate conductive layer, the conductive layer is cyclically added according to steps S11-S13 until a printed circuit board is obtained.

[0037] In a specific application scenario, when the conductive layer is the last conductive layer, outer layer pattern preparation, solder resist, etc. are performed based on the conductive layer to obtain a printed circuit board.

[0038] In a specific application scenario, the conductive layer can also be used as a laminated material to be laminated layer by layer to obtain a printed circuit board. The specific usage of the conductive layer is not limited here.

[0039] The density of the graphene layer in this embodiment is low, which is conducive to lightweight. The thermal conductivity of graphene is high, which can reduce the use of heat dissipation devices in electronic systems, further ensuring lightweight. It can also improve heat dissipation efficiency under conventional copper thickness, which is conducive to high-density wiring design and achieves a balance between heat dissipation, wiring space and lightweight.

[0040] Through the above steps, the method for preparing a printed circuit board of this embodiment obtains a processing plate, and a metal layer is stacked on one side of the processing plate; a graphene layer is deposited on the side of the metal layer away from the processing plate to form a conductive layer in combination with the metal layer; a printed circuit board is prepared based on the conductive layer, and a conductive layer is formed based on a combination of the stacked metal layer and the graphene layer, and graphene is used to improve the heat dissipation efficiency of the printed circuit board, thereby reducing the internal resistance of the conductive layer, and the graphene layer is covered on the corresponding metal layer, which will not increase the occupied space of the graphene layer too much, ensuring the wiring design of the conductive circuit, and can greatly increase the heat dissipation area of ​​the conductive layer, further improve the heat dissipation efficiency, and achieve a balance between heat dissipation, wiring space and lightweight.

[0041] See also Figure 2-3 , Figure 2 The figure is a flow chart of another embodiment of the method for preparing a printed circuit board provided by the present invention. Figure 3 for Figure 2 The present embodiment is described by taking the processed board as a carrier board as an example.

[0042] Step S21: Obtain a processed plate, one side of which is laminated with a metal layer.

[0043] In a specific application scenario, a carrier plate is obtained and used as a processing plate, and a metal layer is stacked on one side of the processing plate. Positioning holes can be set correspondingly on the edges of the carrier plate and the edges of the metal layer, and the relative position between the metal layer and the processing plate is determined by the positioning holes, and then the stacking is performed.

[0044] The material of the carrier plate can be aluminum nitride, aluminum oxide, titanium, tungsten, steel, etc., for carrying the metal layer. The metal layer includes but is not limited to a copper layer, an aluminum layer, a silver layer, a nickel layer or an alloy layer, etc., which is specifically set based on actual needs.

[0045] See also Figure 3 In 3a, the metal layer 31 and the processing plate 32 are stacked. The horizontal area of ​​the processing plate 32 can be greater than or equal to the area of ​​the metal layer 31, thereby supporting the metal layer 31.

[0046] Step S22: placing a jig plate on a side of the metal layer away from the processed plate; wherein a hollow area is provided on the jig plate based on the shape of the conductive circuit of the conductive layer.

[0047] Please read further Figure 3 In 3b, a jig plate 33 is placed on the side of the metal layer 31 away from the processing plate 32. The jig plate 33 is used in conjunction with the carrier plate, and the material can be selected from aluminum nitride, aluminum oxide, titanium, tungsten, steel, etc.

[0048] The jig plate 33 is provided with a hollow area based on the shape of the conductive circuit of the corresponding conductive layer. That is, the shape of the hollow area is the shape of the conductive circuit of the conductive layer. The hollow area on the jig plate 33 can be prepared by water jet / laser cutting or the like.

[0049] Please read further Figure 4 , Figure 4 It is a top view of the structure of one embodiment of a jig plate.

[0050] The jig plate 33 is provided with a plurality of positioning holes 331 to facilitate accurate lamination on the metal layer 31. The jig plate 33 is also provided with a hollow area 332, and the shape of the hollow area 332 is the same as the shape of the conductive line of the corresponding conductive line.

[0051] The preparation of each conductive layer of the printed circuit board can be performed respectively through a plurality of jig plates 33 so as to realize the formation of the conductive circuit of each conductive layer.

[0052] Step S23: performing graphene deposition on a side of the metal layer away from the processing plate to form a graphene layer in the hollow area; wherein the graphene layer has a shape of a conductive line of the conductive layer.

[0053] Please read further Figure 3 In 3c, graphene deposition is performed on the side of the metal layer 31 away from the processing plate 32 to form a graphene layer 34 in the hollow area 332; wherein the graphene layer 34 has the shape of a conductive line of the conductive layer.

[0054] In a specific application scenario, chemical vapor deposition (CVD) technology can be used to heat the side of the metal layer 31 away from the processing plate 32 in an atmosphere of a carbon source and a carrier gas, so that a deposition reaction occurs in the hollow area 332 to generate carbon atoms to form a graphene layer 34. Specifically, chemical vapor deposition (CVD) technology is used to pass a gas containing a carbon source and a carrier gas through a reaction chamber, and reacts with the surface of the metal layer 31 at a high temperature to generate carbon atoms and deposit them on the surface of the metal layer 31, and finally form a graphene layer 34. The carrier gas is a mobile phase used in gas chromatography, usually a gas. Commonly used carrier gases include hydrogen, helium, nitrogen, argon or carbon dioxide.

[0055] In a specific application scenario, a carbon source can be formed in the hollow area 332, and hydrocarbon gas can be thermally decomposed to form a graphene layer 34. Specifically, the graphene layer 34 is prepared by thermally decomposing hydrocarbon gas such as methane, and after the carbon source is formed on the surface of the metal layer 31, it diffuses to the surface through the lattice holes on the surface of the metal layer 31 to form a nano-scale graphene layer 34.

[0056] See also Figure 5 , Figure 5 It is a schematic diagram of a top view structure of an embodiment of a graphene layer.

[0057] The graphene layer 34 has the shape of a conductive line of the conductive layer.

[0058] In this embodiment, the deposition of graphene by means of a mask of the jig plate 33 can greatly improve the preparation precision and accuracy of the graphene layer 34, so that it matches the corresponding conductive circuit, thereby combining with the metal layer to form the conductive circuit of the conductive layer and realize the electrical function.

[0059] Step S24: removing the jig plate and the exposed metal layer to obtain a conductive layer having conductive circuits formed thereon.

[0060] Please read further Figure 3 In step 3d, the jig plate 33 is removed, and the exposed metal layer 31 is removed to obtain a conductive layer 35 formed with a conductive circuit.

[0061] Specifically, the jig plate 33 is removed, and the metal layer 31 not covered by the graphene layer 34 is removed by water jet or laser cutting to obtain the metal layer 31 having the shape of a conductive circuit; the metal layer 31 and the graphene layer 34 are combined to obtain the conductive layer 35 having the shape of a conductive circuit.

[0062] Waterjet: It uses water as a knife. Its original name is high-pressure water jet cutting technology. It is mostly used for cutting metal materials in special fields. Laser cutting uses a high-power density laser beam to irradiate the material to be cut, so that the material is quickly heated to the vaporization temperature and evaporates to form holes. As the beam moves on the material, the holes continuously form a very narrow slit to complete the cutting of the material.

[0063] The thickness of the metal layer 31 is at least 1.5 microns, and can be 1.5 microns, 5 microns, 15 microns, 26 microns, 34 microns, 50 microns, 68 microns, 70 microns, 88 microns, 100 microns, 120 microns, 150 microns or 200 microns, etc. The thickness is set based on actual needs and is not limited here.

[0064] The thickness of the graphene layer 34 ranges from 0.3 nm to 25000 nm, and may be 0.3 nm, 0.9 nm, 1.5 nm, 100 nm, 150 nm, 200 nm, 400 nm, 600 nm, 800 nm, 1000 nm, 3000 nm, 7000 nm, 10000 nm, 15000 nm, 20000 nm or 25000 nm, etc. The thickness is set based on actual needs and is not limited here.

[0065] Step S25: Laminating a dielectric layer and a build-up metal layer on a side of the conductive layer away from the processed board.

[0066] Please read further Figure 3 In 3e , a dielectric layer 36 and a build-up metal layer 37 are laminated on the side of the conductive layer 35 away from the processing plate 32 .

[0067] Among them, the dielectric layer 36 includes but is not limited to one or more insulating materials such as prepreg, epoxy resin, polyester resin (PET), polyimide, polyimide, polycarbonate (PC), bismaleimide triazine (BT), Ajinomoto build film (ABF), FR4 resin, ceramic base, etc.

[0068] The build-up metal layer 37 includes, but is not limited to, a copper layer, an aluminum layer, a silver layer, a nickel layer or an alloy layer, etc., and is specifically configured based on actual needs and is not limited here.

[0069] After lamination, the processed plate 32 is removed. After lamination, the dielectric layer 36 fills the gap between the conductive layer 35 and the build-up metal layer 37 .

[0070] Step S26: connecting the build-up metal layer and the conductive layer to obtain a printed circuit board.

[0071] Please read further Figure 3 3f in the figure connects the build-up metal layer 37 and the conductive layer 35 to obtain a printed circuit board 30.

[0072] In a specific application scenario, holes can be drilled from the side of the build-up metal layer 37 away from the metal layer 31 until a plurality of blind holes (not marked in the figure) exposing the bare metal layer are formed; the side of the build-up metal layer 37 away from the metal layer 31 is electroplated until all the blind holes are filled to form corresponding metallized holes 372. The metallized holes 372 are used to realize interlayer interconnection between the build-up metal layer 37 and the conductive layer 35.

[0073] In a specific application scenario, if the build-up metal layer 37 is the last conductive layer of the printed circuit board 30 , the build-up metal layer may be etched to form a corresponding conductive circuit 371 to obtain the printed circuit board 30 .

[0074] Specifically, the above process first performs hole production and hole metallization production: drilling → hole processing (drilling decontamination) → hole metallization → electroplating; then performs circuit transfer: pre-processing → film lamination → exposure → development → etching → inspection, until the corresponding conductive circuit 371 and metallized hole 372 are formed. Finally, the entire board is subjected to solder mask → appearance → testing → inspection → packaging to obtain the final printed circuit board 30.

[0075] In a specific application scenario, if the build-up metal layer is an intermediate conductive layer, the entire board is used as a built-up board after electroplating, and the graphene layer is deposited again on the side of the build-up metal layer away from the built-up board, and the steps of pressing, drilling and electroplating are performed; and so on, the stacking cycle is repeated until a printed circuit board is prepared.

[0076] See also Figure 6 , Figure 6 It is a schematic diagram of the structure of the already added layer panel after adding more layers.

[0077] The laminated plate 60 of this embodiment includes a first conductive layer 61, a second conductive layer 62, and a third conductive layer 63 which are sequentially laminated. A dielectric layer 64 is sandwiched between each adjacent conductive layer for dielectric purposes. Each conductive layer can be obtained by combining a metal layer and a graphene layer which are laminated. The outermost third conductive layer 63 can also be only a metal layer, which is specifically set based on actual needs.

[0078] When more layers need to be added, the stacked plate 60 can be used as a new plate to be processed, and steps S22-S26 are continuously executed in a loop until the added layers meet the preset requirements to obtain a printed circuit board. The preset requirements can be to reach a preset number of conductive layers or a preset thickness of the plate, and the specific values ​​are set based on actual needs.

[0079] Through the above structure, the preparation method of the printed circuit board of this embodiment is to obtain a processing plate, one side of the processing plate is stacked with a metal layer, a jig plate is placed on the side of the metal layer away from the processing plate, and graphene is deposited on the side of the metal layer away from the processing plate to form a graphene layer in the hollow area; wherein the graphene layer has the shape of the conductive circuit of the conductive layer, the jig plate is removed, and the exposed metal layer is removed to obtain a conductive layer formed with a conductive circuit, and a dielectric layer and a build-up metal layer are pressed on the side of the conductive layer away from the processing plate, and the build-up metal layer and the conductive layer are connected to obtain a printed circuit board. Thus, the conductive layer is formed based on the combination of the stacked metal layer and the graphene layer, which not only realizes the "thin" layer setting of the conductive layer but also uses graphene to improve the heat dissipation efficiency of the printed circuit board, and the graphene layer is covered on the corresponding metal layer, which will not increase the occupied space of the graphene layer too much, ensuring the wiring design of the conductive circuit, and can greatly increase the heat dissipation area of ​​the conductive layer, further improving the heat dissipation efficiency. Moreover, in this embodiment, the deposition of the graphene layer by means of a jig plate mask can greatly improve the preparation precision and accuracy of the graphene layer, so that it matches the corresponding conductive circuit, thereby combining with the metal layer to form the conductive circuit of the conductive layer and realize the electrical function.

[0080] See also Figure 7 , Figure 7The printed circuit board of this embodiment can be prepared by the method for preparing the printed circuit board of any of the above embodiments.

[0081] The printed circuit board 70 of this embodiment includes a conductive layer 71 , and the conductive layer 71 includes a metal layer 711 and a graphene layer 712 which are sequentially stacked and bonded.

[0082] Through the above structure, this embodiment forms a conductive layer based on a combination of stacked metal layers and graphene layers, and uses graphene to improve the heat dissipation efficiency of the printed circuit board. The graphene layer is covered on the corresponding metal layer, which will not increase the space occupied by the graphene layer too much, thereby ensuring the wiring design of the conductive circuit, and can greatly increase the heat dissipation area of ​​the conductive layer, further improving the heat dissipation efficiency.

[0083] In other embodiments, a dielectric layer 74 is disposed between each conductive layer 71 for dielectric purposes, and a metallized hole 75 is disposed between each two adjacent conductive layers 71 for conduction.

[0084] In other embodiments, the outer conductive layer 76 may include only a metal structure without a graphene structure, because the outer conductive layer 76 can directly dissipate heat with the air to ensure heat dissipation efficiency.

[0085] In other embodiments, solder resist layers 77 may be provided on opposite sides of the printed circuit board 70, and the solder resist layers 77 include but are not limited to ink, covering films, etc. The solder resist layers 77 cover most of the corresponding side surfaces, and may expose pads, connection points, etc. for external electrical connection.

[0086] In other embodiments, the thickness of the metal layer 711 is at least 1.5 microns, and can be 1.5 microns, 5 microns, 15 microns, 26 microns, 34 microns, 50 microns, 68 microns, 70 microns, 88 microns, 100 microns, 120 microns, 150 microns or 200 microns, etc. The thickness is set based on actual needs and is not limited here. The metal layer 711 within this range can achieve a high-density circuit design through a "thin layer" design, and use the graphene layer 712 to improve heat dissipation efficiency and reduce circuit internal resistance.

[0087] The thickness of the graphene layer 712 ranges from 0.3 nanometers to 25,000 nanometers. Specifically, it can be 0.3 nanometers, 0.9 nanometers, 1.5 nanometers, 100 nanometers, 150 nanometers, 200 nanometers, 400 nanometers, 600 nanometers, 800 nanometers, 1000 nanometers, 3000 nanometers, 7000 nanometers, 10000 nanometers, 15000 nanometers, 20000 nanometers or 25000 nanometers, etc. It is specifically set based on actual needs and is not limited here. The graphene layer 712 within this range can achieve high heat dissipation and reduce the lightweight effect on the printed circuit board 70.

[0088] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a printed circuit board, characterized in that: The method for preparing the printed circuit board comprises: Obtaining a processed plate, wherein a metal layer is laminated on one side of the processed plate; Depositing a graphene layer on a side of the metal layer away from the processing plate to form a conductive layer in combination with the metal layer; The printed circuit board is prepared based on the conductive layer.

2. The method for preparing a printed circuit board according to claim 1, characterized in that: The step of depositing a graphene layer on a side of the metal layer away from the processing plate to form a conductive layer in combination with the metal layer comprises: A jig plate is placed on the side of the metal layer away from the processing plate; wherein a hollow area is provided on the jig plate based on the shape of the conductive circuit of the conductive layer; Depositing graphene on the side of the metal layer away from the processing plate to form the graphene layer in the hollow area; wherein the graphene layer has the shape of the conductive line of the conductive layer; The jig plate is removed, and the exposed metal layer is removed to obtain the conductive layer formed with conductive circuits.

3. The method for preparing a printed circuit board according to claim 2, characterized in that: The step of depositing graphene on a side of the metal layer away from the processing plate to form the graphene layer in the hollow area comprises: Using chemical vapor deposition technology, in an atmosphere of a carbon source and a carrier gas, the side of the metal layer away from the processing plate is heated to cause a deposition reaction to generate carbon atoms to form the graphene layer; or A carbon source is formed in the hollow region, and the graphene layer is formed by thermally decomposing hydrocarbon gas.

4. The method for preparing a printed circuit board according to claim 2, characterized in that: The step of removing the jig plate and the exposed metal layer to obtain the conductive layer having the conductive circuit formed thereon comprises: Removing the jig plate, and removing the metal layer not covered by the graphene layer by water jet or laser cutting to obtain a metal layer in the shape of a conductive circuit; The metal layer and the graphene layer are combined to obtain the conductive layer.

5. The method for preparing a printed circuit board according to claim 1, characterized in that: The step of preparing the printed circuit board based on the conductive layer comprises: Laminating a dielectric layer and a build-up metal layer on a side of the conductive layer away from the processing plate; The build-up metal layer and the conductive layer are connected to obtain the printed circuit board.

6. The method for preparing a printed circuit board according to claim 5, characterized in that: The processed plate includes: a built-up plate or a load-bearing plate; When the processed board is a carrier board, after the step of laminating the dielectric layer and the build-up metal layer on the side of the conductive layer away from the processed board, the step includes: The carrier plate is removed.

7. The method for preparing a printed circuit board according to claim 5 or 6, characterized in that: The step of connecting the build-up metal layer and the conductive layer comprises: Drilling holes from a side of the build-up metal layer away from the metal layer until a plurality of blind holes exposing the metal layer are formed; Electroplating is performed on a side of the build-up metal layer away from the metal layer until the blind holes are fully filled to form a metallized hole connecting the build-up metal layer and the conductive layer.

8. The method for preparing a printed circuit board according to claim 5 or 6, characterized in that: The step of connecting the build-up metal layer and the conductive layer to obtain the printed circuit board also includes: Etching the build-up metal layer to form a corresponding conductive circuit to obtain the printed circuit board; or The added metal layer and the conductive layer are connected to obtain a built-up board, and the built-up board is used as a new processed board; the new processed board is repeatedly subjected to the steps of depositing a graphene layer on a side of the metal layer away from the processed board to form a conductive layer in combination with the metal layer; and the steps of preparing the printed circuit board based on the conductive layer, until the built-up board meets the preset requirements, thereby obtaining the printed circuit board.

9. A printed circuit board, characterized in that: The printed circuit board is prepared by the method for preparing a printed circuit board according to any one of claims 1 to 8, comprising: The conductive layer includes a metal layer and a graphene layer which are stacked and bonded in sequence.

10. The printed circuit board according to claim 9, characterized in that: The thickness of the metal layer ranges from at least 1.5 micrometers; The thickness of the graphene layer ranges from 0.3 nanometers to 25000 nanometers.

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