Printed circuit board and method for preparing the same

Abstract

This application discloses a printed circuit board and a method for manufacturing the same, comprising: obtaining at least one board to be processed, wherein each board to be processed has a metal layer formed on at least one side; sequentially performing micro-etching and chemical modification on the surface of each metal layer; and laminating the at least one chemically modified board to be processed with at least one dielectric layer to produce the printed circuit board. Through this method, the present application can simultaneously ensure inter-board bonding strength and signal transmission of the printed circuit board, thereby improving the reliability of the printed circuit board.

Description

Technical Field

[0001] The present application relates to the technical field of circuit board preparation, and in particular to a printed circuit board and a preparation method thereof. Background Art

[0002] As the signal transmission frequency of mobile devices continues to increase, the skin effect of wires has an increasingly significant impact on signal transmission, and signal transmission tends to be more surface-oriented.

[0003] For printed circuit boards, although a smoother surface is more conducive to signal transmission, the smooth surface will also significantly reduce the bonding strength between the inner metal layer and the dielectric layer, leading to inner layer interconnection problems such as board delamination, board explosion, and blistering.

[0004] Currently, printed circuit board (PCB) production primarily utilizes blackening or browning processes to enhance the bonding between the polished inner metal layer and the dielectric layer. However, high-speed, high-frequency communications products require copper foil with low surface roughness and specific surface area to minimize signal loss during transmission. Summary of the Invention

[0005] The main technical problem solved by the present application is to provide a printed circuit board and a preparation method thereof, which can solve the problem that it is difficult for printed circuit boards to simultaneously ensure the bonding strength between boards and signal transmission.

[0006] In order to solve the above technical problems, the first technical solution adopted in this application is to provide a method for preparing a printed circuit board, including: obtaining at least one board to be processed, wherein a metal layer is formed on at least one side of each board to be processed; performing micro-etching and chemical modification treatment on the surface of each metal layer in turn; and pressing at least one layer of the board to be processed after the chemical modification treatment with at least one layer of the dielectric layer to prepare a printed circuit board.

[0007] Among them, the steps of micro-etching and chemically modifying the surface of each metal layer in sequence include: micro-etching the surface of each metal layer with a micro-etching solution to form hydroxyl groups on the surface of each metal layer; chemically modifying the hydroxyl groups on the surface of each metal layer with a coupling agent solution and a polysilsesquioxane solution to obtain a plate to be processed after chemical modification.

[0008] The metal layer includes a copper layer, and the micro-etching solution includes sulfuric acid and hydrogen peroxide.

[0009] Among them, the steps of chemically modifying the hydroxyl groups on the surface of each metal layer by using a coupling agent solution and a polysilsesquioxane solution to obtain the chemically modified plate parts to be processed include: spraying the coupling agent solution onto the surface of each metal layer after micro-etching treatment, so that the hydroxyl groups in the coupling agent solution and the hydroxyl groups on the surface of each metal layer are dehydrated and condensed to form a silane layer on the surface of each metal layer; drying each plate part to be processed; spraying the polysilsesquioxane solution onto the surface of each metal layer after drying treatment to cross-link and solidify with the silane layer to obtain the chemically modified plate parts to be processed.

[0010] The step of spraying the polysilsesquioxane solution onto the surfaces of the dried metal layers includes: hydrolyzing the coupling agent to form hydroxyl groups in the coupling agent to obtain a coupling agent solution.

[0011] The step of hydrolyzing the coupling agent to form hydroxyl groups to obtain a coupling agent solution includes: hydrolyzing the coupling agent with ethanol and water, stirring at a set temperature for a set time, and controlling the pH value within a preset pH range to obtain a coupling agent solution with a first preset concentration.

[0012] Among them, the volume ratio of ethanol to water ranges from 5:1 to 20:1; the preset pH range is 3 to 5; the set temperature is room temperature, the set time range is 50-70 minutes; the first preset concentration range is 0.5 to 5.0 wt%.

[0013] The step of spraying the polysilsesquioxane solution onto the surfaces of the dried metal layers includes, before the step of spraying the polysilsesquioxane solution onto the surfaces of the dried metal layers, dissolving the polysilsesquioxane in tetrahydrofuran and stirring the solution at a set temperature for a set time to obtain a polysilsesquioxane solution having a second predetermined concentration. The second predetermined concentration ranges from 1.0 to 5.0 wt %.

[0014] Among them, the step of pressing at least one layer of the to-be-processed board after chemical modification treatment and at least one layer of dielectric layer to prepare a printed circuit board includes: washing and drying each of the to-be-processed board after chemical modification treatment in sequence to obtain a to-be-pressed board; placing at least one layer of the to-be-pressed board and at least one layer of dielectric layer in a cross-layered manner in sequence and pressing them to prepare a printed circuit board.

[0015] In order to solve the above technical problems, the second technical solution adopted in this application is to provide a printed circuit board, which is prepared by any of the above-mentioned printed circuit board preparation methods.

[0016] The beneficial effect of the present application is as follows: Different from the prior art, the present application prepares a printed circuit board by sequentially performing micro-etching and chemical modification treatments on the surfaces of each metal layer, and then pressing at least one layer of the to-be-processed board after chemical modification with at least one layer of dielectric layer. When the to-be-processed board and the dielectric layer are pressed together, sufficient bonding force can be maintained between each metal layer and the dielectric layer through the surfaces of the chemically modified metal layers, thereby achieving interlayer bonding. Moreover, since the surfaces of each metal layer are only micro-etched, the signal transmission loss is reduced, thereby ensuring the signal transmission effect of the printed circuit board, achieving simultaneous guarantee of inter-board bonding force and signal transmission, and improving the reliability of the printed circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 This is a flow chart of an embodiment of a method for preparing a printed circuit board according to the present application;

[0019] Figure 2 This is a schematic flow chart of another embodiment of the method for preparing a printed circuit board of the present application;

[0020] Figure 3 yes Figure 2 A schematic diagram of a first embodiment of a micro-etching step in an embodiment;

[0021] Figure 4 yes Figure 2 A schematic diagram of an embodiment of spraying a coupling agent solution for treatment in an embodiment;

[0022] Figure 5 yes Figure 2 Schematic diagram of an embodiment of spraying polysilsesquioxane solution treatment in an embodiment;

[0023] Figure 6 It is a structural diagram of an embodiment of the printed circuit board of the present application. DETAILED DESCRIPTION

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

[0025] The terms used in the embodiments of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a," "the," and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless otherwise clearly indicated above. "A plurality" generally includes at least two, but does not exclude the inclusion of at least one.

[0026] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0027] It should be understood that the terms "comprises," "comprising," or any other variations used herein are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0028] The present application is described in detail below with reference to the accompanying drawings and implementation methods.

[0029] See also Figure 1 , Figure 1 1 is a flow chart of an embodiment of a method for preparing a printed circuit board of the present application. In this embodiment, the preparation method includes:

[0030] S11: Acquire at least one plate to be processed, wherein a metal layer is formed on at least one side of each plate to be processed.

[0031] The plate to be processed can include a single-layer metal plate, such as a copper plate, an aluminum plate, or a silver plate, or a multi-layer plate. A multi-layer plate can be formed by sequentially cross-laminating metal layers and dielectric layers, with a metal layer formed on at least one side of the multi-layer plate. Examples include single-sided copper-clad laminates and double-sided copper-clad laminates. The specific structure of the plate to be processed is not limited herein.

[0032] The number of panels to be processed obtained in this step can be one or more, for example: 1, 3, 4, 6, 8, etc., which can be specifically determined based on the preparation requirements of the printed circuit board and is not limited here.

[0033] S12: performing micro-etching and chemical modification treatments on the surfaces of the metal layers in sequence.

[0034] First, the metal layer surfaces of each panel to be processed are micro-etched. This treatment reduces the roughness of the metal layer surface, Rz, to below 1.2μm. This effectively reduces signal loss caused by the metal layer. The metal layer surface refers to the exposed side of the metal layer away from the corresponding panel to be processed.

[0035] The surfaces of the metal layers are then chemically modified to improve the bonding strength of the metal layers. Chemical modification is a method of changing the physical and chemical properties of the metal layer surface through chemical reactions.

[0036] Since the organic metal layer in the printed circuit board is mainly combined with the inorganic dielectric layer, the surface of each metal layer can be chemically modified using a chemical agent that is reactive with both inorganic and organic substances. Such a chemical agent may include a coupling agent or other agents that meet the above-mentioned characteristics, such as KH550 (γ-aminopropyltriethoxysilane), KH560 (γ-glycidoxypropyltrimethoxysilane), or KH570 (γ-(methacryloyloxy)propyltrimethoxysilane). This is not limited here.

[0037] S13: laminating the at least one chemically modified board to be processed with the at least one dielectric layer to prepare a printed circuit board.

[0038] The dielectric layer may include one or more inorganic insulating materials such as prepreg, epoxy resin, polyester resin (PET), polyimide, polyimide, polycarbonate (PC), bismaleimide triazine (BT), ceramic base, etc.

[0039] Since the metal layers of the panels to be processed have been micro-etched and chemically modified, during lamination, the metal layers and the dielectric layer can maintain sufficient bonding strength through the chemically modified metal layer surfaces to achieve interlayer bonding. Moreover, since the metal layer surfaces are only micro-etched, the signal transmission loss of the metal layers is reduced, thereby ensuring the signal transmission effect of the printed circuit board.

[0040] Through the above steps, the method for preparing a printed circuit board of this embodiment prepares a printed circuit board by sequentially performing micro-etching and chemical modification on the surfaces of each metal layer, and then pressing at least one layer of the to-be-processed board after the chemical modification with at least one layer of the dielectric layer. This allows the to-be-processed board and the dielectric layer to maintain sufficient bonding strength between the metal layers and the dielectric layer through the surfaces of the chemically modified metal layers when they are pressed together, thereby achieving interlayer bonding. Moreover, since the surfaces of each metal layer are only micro-etched, the signal transmission loss is reduced, thereby ensuring the signal transmission effect of the printed circuit board, achieving simultaneous guarantee of inter-board bonding strength and signal transmission, and improving the reliability of the printed circuit board.

[0041] See also Figure 2 , Figure 2 FIG. 1 is a flow chart of another embodiment of the method for preparing a printed circuit board of the present application. In this embodiment, the method comprises:

[0042] Step S21: obtaining at least one plate to be processed, wherein a metal layer is formed on at least one side of each plate to be processed.

[0043] This step is the same as step S11 in the aforementioned embodiment. Please refer to the above text and will not be repeated here.

[0044] Step S22: performing micro-etching treatment on the surface of each metal layer using a micro-etching solution to form hydroxyl groups on the surface of each metal layer.

[0045] Before micro-etching the plate to be processed, the plate can be cleaned with alkali to remove stains such as oil and impurities on the metal surface of the plate, thereby improving the efficiency and effect of subsequent micro-etching.

[0046] The metal layers are micro-etched using a micro-etching solution. This treatment reduces the roughness of the metal layers, lowering the Rz to below 1.2μm. This effectively reduces signal loss caused by the metal layers.

[0047] In a specific application scenario, the metal layer may include a copper layer, and the micro-etching solution may include sulfuric acid and hydrogen peroxide. The micro-etching solution contains sulfuric acid and hydrogen peroxide, which have strong oxidizing properties and can form Cu on the copper surface. x O y Oxide layer, so that the surface of each metal layer forms hydroxyl groups, which can prepare for the next step of impregnation coupling agent. x O y Mainly CuO and Cu2O. In other application scenarios, the metal layer can be other metals, and the micro-etching solution can also include other acidic substances, but micro-etching of both requires the formation of hydroxyl groups on the surface of each metal layer.

[0048] See also Figure 3, Figure 3 yes Figure 2 Schematic diagram of an embodiment of a micro-etching step in an embodiment.

[0049] The panel 10 to be processed in this embodiment is described by taking a double-sided copper clad laminate as an example. The panel 10 to be processed includes a metal layer 11 , a base layer 12 and a metal layer 11 which are sequentially stacked and bonded.

[0050] A micro-etching solution is applied to the surface of the metal layer 11 to perform micro-etching treatment to form hydroxyl groups on the surface of the plate 10 to be processed, in preparation for the next step of impregnation with a coupling agent.

[0051] The surface of the metal layer 11 that has been micro-etched is the surface that needs to be laminated with the dielectric layer later. When the plate 10 to be processed is a copper plate, micro-etching can be performed on one side or two opposite sides of the plate 10 to be processed as needed.

[0052] In other embodiments, the plate to be processed may also be a single-layer metal plate, and its micro-etching step and subsequent chemical treatment steps are similar to those of the plate to be processed 10 in this embodiment, and will not be repeated.

[0053] Step S23: chemically modifying the hydroxyl groups on the surface of each metal layer using a coupling agent solution and a polysilsesquioxane solution to obtain a plate to be processed after chemical modification.

[0054] Before chemically modifying the surfaces of the metal layers using a coupling agent solution, the coupling agent needs to be hydrolyzed to form hydroxyl groups in the coupling agent to obtain a coupling agent solution.

[0055] Specifically, the coupling agent can be hydrolyzed with ethanol and water, stirred at a set temperature for a set time, and the pH value is controlled within a preset pH range to obtain a coupling agent solution with a first preset concentration.

[0056] The volume ratio of ethanol to water ranges from 5:1 to 20:1, and can specifically be 5:1, 8:1, 10:1, 12:1, 13:1, 15:1, 18:1, or 20:1; the preset pH range is from 3 to 5, and can specifically be 3, 4, or 5; the set temperature can be room temperature; the set duration ranges from 50 to 70 minutes, and can specifically be 50 minutes, 55 minutes, 60 minutes, 62 minutes, 68 minutes, or 70 minutes; the first preset concentration ranges from 0.5 to 5.0 wt%, and can specifically be 0.5 wt%, 1.0 wt%, 1.6 wt%, 2.0 wt%, 2.5 wt%, 3.4 wt%, 3.9 wt%, 4.1 wt%, 4.6 wt%, or 5.0 wt%, and is not limited here.

[0057] In a specific application scenario, the coupling agent can be hydrolyzed by mixing ethanol and water in a volume ratio of 10:1, stirring at room temperature for 60 minutes, and controlling the pH value within 4 to obtain a 2.0 wt% coupling agent solution.

[0058] The coupling agent can be a silane coupling agent, and its molecular structure is generally R-Si(OY)3, where R is an organic functional group and SiOY is a silaneoxy group. Silaneoxy groups are reactive toward inorganic substances, and organic functional groups are reactive or compatible toward organic substances. Therefore, when the silane coupling agent is located between the inorganic and organic interfaces, a bonding layer of an organic matrix-silane coupling agent-inorganic matrix can be formed. The silane coupling agent of this embodiment can include KH550 (γ-aminopropyltriethoxysilane, KH560 (γ-glycidyloxypropyltrimethoxysilane) or KH570 (γ-(methacryloyloxy)propyltrimethoxysilane), etc., without limitation herein.

[0059] After the hydrolysis treatment, the coupling agent solution is first sprayed onto the surface of each metal layer after the micro-etching treatment, so that the hydroxyl groups in the coupling agent solution and the hydroxyl groups on the surface of each metal layer undergo dehydration condensation to form a silane layer on the surface of each metal layer.

[0060] See also Figure 4 , Figure 4 yes Figure 2 Schematic diagram of one embodiment of spraying coupling agent solution treatment in an embodiment.

[0061] This diagram uses KH550 silane coupling agent as an example.

[0062] This embodiment Figure 3 Based on the implementation method, the silane coupling agent undergoes a cross-linking reaction with the -OH groups on the surface of the metal layer 11, and the hydroxyl groups in the coupling agent solution undergo dehydration condensation with the hydroxyl groups on the surface of the metal layer 11 to form a Cu-O-Si covalent bond connection, so that the silane coupling agent is grafted onto the surface of the metal layer 11 through the -OH groups to form a silane layer 20.

[0063] After treating the surface of the metal layer on at least one side of the plate to be processed with a silane coupling agent, each plate to be processed is dried.

[0064] Prior to the step of spraying the polysilsesquioxane solution onto the surfaces of the dried metal layers, the method further includes dissolving the polysilsesquioxane in tetrahydrofuran and stirring the solution at a set temperature for a set time to obtain a polysilsesquioxane solution having a second predetermined concentration. The set temperature and the set time are the same as those described above, and the second predetermined concentration ranges from 1.0 to 5.0 wt%, and specifically can be 1.0 wt%, 1.5 wt%, 1.9 wt%, 2.0 wt%, 2.5 wt%, 2.6 wt%, 2.8 wt%, 3.1 wt%, 3.5 wt%, 3.8 wt%, 4.0 wt%, 4.3 wt%, 4.8 wt%, or 5.0 wt%.

[0065] In a specific application scenario, before spraying the polysilsesquioxane solution on the metal layer, an appropriate amount of polysilsesquioxane is weighed and dissolved in tetrahydrofuran, and the solution is stirred at room temperature for 60 minutes to prepare a 5 wt% polysilsesquioxane solution.

[0066] Then, the polysilsesquioxane solution is sprayed onto the surface of each metal layer after the drying treatment to crosslink and solidify with the silane layer to obtain a plate to be processed after chemical modification treatment.

[0067] The polysilsesquioxane may be a polyhedral oligomericsilsesquioxane (POSS) with the general formula (RSiO3 / 2)n, where R represents the groups attached to the eight corner Si atoms. POSS is an inorganic core composed of a silicon-oxygen backbone with alternating Si-O bonds. The groups R attached to the eight corner Si atoms can be reactive groups (amino groups, epoxy groups, carbon-carbon double bonds, etc.).

[0068] The side chain groups R' of the polysilsesquioxane (POSS) must be reactive with the side chain groups R of the silane coupling agent for grafting. For example, if the side chain groups of the silane coupling agent are amino (-NH2), the side chain groups R' of the POSS can be epoxy (-CH(O)CH-).

[0069] The copper foil surface is further modified using polysilsesquioxane. Because polysilsesquioxane has an inorganic core composed of a silicon-oxygen backbone with alternating Si-O bonds, it inhibits polymer chain motion and imparts excellent thermal stability to the bonding interface, further enhancing the weather resistance of the printed circuit board. Furthermore, the multiple side chain groups in polysilsesquioxane allow the metal surface to serve as a crosslinking and curing center, improving the peel strength between the metal and dielectric layers. The side chain groups R' can also be adjusted to accommodate different polymers, making it highly customizable.

[0070] See also Figure 5 , Figure 5 yes Figure 2Schematic diagram of one embodiment of spraying polysilsesquioxane solution treatment in an embodiment.

[0071] This embodiment Figure 4 On the basis of the embodiment, the side chain groups of polysilsesquioxane are grafted onto the silane layer 20 to further modify the surface of the metal layer 11 to obtain a plate to be processed after chemical modification.

[0072] Step S24: washing and drying the chemically modified panels in sequence to obtain panels to be pressed.

[0073] After the chemical modification, the panels are washed and dried to obtain panels ready for lamination. The washing process is used to remove excess chemical solution, and the drying process is used to dry the washed panels to prevent them from affecting the subsequent lamination process.

[0074] Step S25: at least one layer of the plate to be laminated and at least one dielectric layer are sequentially stacked crosswise and laminated to prepare a printed circuit board.

[0075] During the high-temperature lamination treatment, the highly active organic functional groups of the silane coupling agent on the surface of the panel to be pressed can react with the resin of the dielectric layer, so that the silane coupling agent and the dielectric layer form a covalent bond, thereby improving the bonding strength between the metal layer and the dielectric layer on the surface of the panel to be processed, and reducing the occurrence of delamination and explosion of the printed circuit board.

[0076] After lamination, the panels may be subjected to drilling, electroplating, etching, solder resist, and other processes to produce printed circuit boards. Specific processes may be configured based on the production requirements of the printed circuit boards and are not limited here.

[0077] Through the above steps, the method for preparing a printed circuit board of this embodiment uses a micro-etching process. Compared with traditional browning and blackening processes, it can reduce the roughness of the copper foil surface and reduce the signal loss caused by it. At the same time, a thin oxide layer is formed on the surface of the metal layer to form hydroxyl groups, preparing for the grafting of the coupling agent. Furthermore, the surface of the metal layer is treated with a coupling agent solution, and the hydroxyl groups are grafted on the surface of the metal layer through a chemical reaction to form a silane layer, which can provide higher interlayer bonding strength. The surface of the metal layer is further modified using polysilsesquioxane. Polysilsesquioxane has an inorganic core composed of a silicon-oxygen skeleton with alternating Si-O connections. It can inhibit the chain motion of polymer molecules and impart good thermal stability to the bonding interface, which can further improve the weather resistance of the printed circuit board. The characteristic of polysilsesquioxane's multiple side chain groups is that the surface of the metal layer can serve as a cross-linking and curing center, which not only improves the peel strength between the metal layer and the semi-cured sheet, but also adjusts the side chain group R' to adapt to different polymers, making it highly customizable. The above preparation method can reduce the surface roughness of the metal layer and reduce signal transmission loss, while improving its bonding strength with the dielectric layer to meet the current requirements of high-frequency communication equipment for low signal loss and high reliability.

[0078] See also Figure 6 , Figure 6 It is a structural diagram of an embodiment of the printed circuit board of the present application.

[0079] The printed circuit board 60 of this embodiment is prepared by the method for preparing a printed circuit board of any of the above embodiments. The printed circuit board 60 of this embodiment can be applied to high-frequency transmission, optoelectronic interconnection, etc., without limitation herein.

[0080] Printed circuit board 60 includes multiple metal layers 61 and multiple dielectric layers 62, stacked and bonded together. Metal layer 61 may be sequentially treated with microetching, silane coupling agent, and polysilsesquioxane before being laminated to dielectric layer 62. As a result, printed circuit board 60 of this embodiment exhibits high interlayer bonding strength, meeting the low signal loss and high reliability requirements of current high-frequency communication equipment. Furthermore, metal layer 61 has a low surface roughness, which reduces signal transmission loss.

[0081] In other embodiments, conductive holes, mounting grooves, electronic components for welding, conductive circuits with preset patterns formed on the metal layer 61, etc. may be formed on the printed circuit board 60. The specific requirements may be based on the preparation requirements of the printed circuit board 60 and are not limited here.

[0082] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a printed circuit board, characterized in that: include: Obtaining at least one plate to be processed, wherein a metal layer is formed on at least one side of each of the plate to be processed; The surfaces of the metal layers are sequentially subjected to micro-etching and chemical modification treatments; wherein, the surfaces of the metal layers are micro-etched with a micro-etching solution to form hydroxyl groups on the surfaces of the metal layers; a coupling agent solution is sprayed onto the surfaces of the metal layers after the micro-etching treatment to cause the hydroxyl groups in the coupling agent solution to undergo dehydration condensation with the hydroxyl groups on the surfaces of the metal layers to form a silane layer on the surfaces of the metal layers; a polysilsesquioxane solution is sprayed onto the surfaces of the metal layers after the drying treatment to cross-link and solidify with the silane layer to obtain a plate to be processed after the chemical modification treatment; The printed circuit board is prepared by laminating at least one layer of the to-be-processed board after chemical modification with at least one dielectric layer.

2. The method for preparing a printed circuit board according to claim 1, wherein: The metal layer includes a copper layer, and the micro-etching solution includes sulfuric acid and hydrogen peroxide.

3. The method for preparing a printed circuit board according to claim 1, wherein: The step of spraying the polysilsesquioxane solution onto the surface of each metal layer after the drying process includes: Each plate to be processed is dried.

4. The method for preparing a printed circuit board according to claim 3, wherein: Before the step of spraying the polysilsesquioxane solution onto the surface of each metal layer after the drying process, the following steps are further included: The coupling agent is subjected to hydrolysis treatment to form a hydroxyl group in the coupling agent, thereby obtaining the coupling agent solution.

5. The method for preparing a printed circuit board according to claim 4, wherein: The step of hydrolyzing the coupling agent to form hydroxyl groups in the coupling agent to obtain the coupling agent solution comprises: The coupling agent is hydrolyzed by ethanol and water, stirred at a set temperature for a set time, and the pH value is controlled within a preset pH range to obtain a coupling agent solution with a first preset concentration.

6. The method for preparing a printed circuit board according to claim 5, wherein: The volume ratio of ethanol to water ranges from 5:1 to 20:1; the preset pH range is from 3 to 5; The set temperature is room temperature, and the set duration ranges from 50 to 70 minutes; The first preset concentration ranges from 0.5 to 5.0 wt %.

7. The method for preparing a printed circuit board according to claim 3, wherein: Before the step of spraying the polysilsesquioxane solution onto the surface of each metal layer after the drying process, the following steps are further included: Dissolving polysilsesquioxane in tetrahydrofuran, stirring at a set temperature and for a set time to obtain a polysilsesquioxane solution of a second preset concentration; Wherein, the second preset concentration ranges from 1.0 to 5.0 wt %.

8. The method for preparing a printed circuit board according to claim 1, wherein: The step of laminating at least one chemically modified plate to be processed with at least one dielectric layer to prepare the printed circuit board comprises: The chemically modified panels are sequentially washed and dried to obtain panels to be pressed; At least one layer of plate to be laminated and at least one dielectric layer are sequentially stacked crosswise and laminated to prepare 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.

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