PCB manufacturing method and PCB

Abstract

The present application discloses a PCB manufacturing method and PCB, the method comprising: obtaining a multilayer board, the multilayer board comprising a first core board, a first water-absorbing resin and a second core board which are stacked, the first water-absorbing resin being between the second copper layer and the third copper layer and being located in a preset opening area; drilling holes in the multilayer board corresponding to the preset opening area to form through holes, the through holes passing through the first water-absorbing resin; chemical copper deposition on the multilayer board, so that the first water-absorbing resin absorbs water and the hole wall of the through hole forms a copper deposition layer, the copper deposition layer at least connects the first copper layer and the second copper layer, and the third copper layer and the fourth copper layer; baking the multilayer board, the first water-absorbing resin expands in the direction of the through hole and protrudes from the hole wall of the through hole to form a first protrusion, and the copper deposition layer attached to the first protrusion is cracked; removing the copper deposition layer or the first protrusion attached to the first protrusion, so that the second copper layer is disconnected from the third copper layer. The present invention solves the technical problem of low production efficiency of circuit boards.

Description

Technical Field

[0001] The present application relates to the technical field of PCB (Printed Circuit Board), and in particular to a PCB manufacturing method and a PCB. Background Art

[0002] In a multi-layer circuit board, the same through hole can only realize the connection of the same network space. In order to realize the connection of different network spaces, each network must connect the networks of different layers through a through hole. In the related art, there are methods such as N+N multiple sub-boards pressing and special mechanical processing methods to remove and separate the hole copper from different parts of the same hole wall, where N is greater than or equal to 1. However, this processing technology is special and the structural design is limited. For example, the N+N method has strict requirements on the heat resistance of the board, and the special mechanical processing method has many restrictions on the aperture size (usually a larger aperture), tool design and processing methods, resulting in low production efficiency of circuit boards with one through hole and multiple network space structures. Summary of the invention

[0003] The main purpose of the present application is to provide a PCB manufacturing method and PCB, aiming to solve the current technical problem of low production efficiency of circuit boards with a one-via-multiple-network space structure.

[0004] To achieve the above object, an embodiment of the present application provides a PCB manufacturing method, wherein the method comprises the following steps:

[0005] S10, obtaining a multilayer board, the multilayer board comprising a first core board, a first water-absorbing resin, and a second core board which are stacked, wherein a first copper layer and a second copper layer are provided on the upper and lower surfaces of the first core board, and the second copper layer faces the second core board; a third copper layer and a fourth copper layer are provided on the upper and lower surfaces of the second core board, and the third copper layer faces the first core board, and the first water-absorbing resin is between the second copper layer and the third copper layer and is located in a preset opening area;

[0006] S20, drilling holes in the multilayer board corresponding to the preset opening areas to form through holes, wherein the through holes pass through the first water-absorbing resin;

[0007] S30, performing chemical copper deposition on the multilayer board, so that the first water-absorbing resin absorbs water and the hole wall of the through hole forms a copper deposition layer, and the first water-absorbing resin absorbs water, and the copper deposition layer at least connects the first copper layer and the second copper layer, and connects the third copper layer and the fourth copper layer;

[0008] S40, performing a baking process on the multilayer board, the first water-absorbing resin expands toward the through hole and protrudes from the hole wall of the through hole to form a first protrusion, and the copper deposition layer attached to the first protrusion is cracked;

[0009] S50, removing the copper deposition layer attached to the first protrusion or the first protrusion to disconnect the second copper layer from the third copper layer.

[0010] In one embodiment, the step S50 specifically includes the following steps:

[0011] The first protrusion or the copper deposited layer attached to the first protrusion is laser ablated to disconnect the second copper layer from the third copper layer; and / or the multilayer board is cleaned with an alkaline solution to remove the first water-absorbing resin.

[0012] In one embodiment, the step S10 specifically includes the following steps: disposing the first water-absorbing resin on a side of the second copper layer facing the third copper layer or on a side of the third copper layer facing the second copper layer; and stacking and pressing the first core board and the second core board to form the multilayer board.

[0013] In one embodiment, the multilayer board also includes a third core board, and the step S10 specifically includes the following steps: the third core board is a semi-cured sheet, and the first water-absorbing resin is embedded on one side of the third core board; the first core board, the third core board and the second core board are stacked in sequence and pressed to form the multilayer board.

[0014] In one embodiment, the multilayer board further includes a first outer copper layer and a second outer copper layer, and step S10 includes the following steps: stacking the first outer copper layer, the first core board, the third core board, the second core board and the second outer copper layer in sequence, and pressing the boards.

[0015] In one embodiment, the first outer copper layer and the first copper layer are provided with a second water-absorbing resin in the preset opening area, and the second outer copper layer and the fourth copper layer are provided with a third water-absorbing resin in the preset opening area.

[0016] In one embodiment, the multilayer board also includes a fourth core board, which is located between the fourth copper layer and the second outer copper layer; a fifth copper layer is provided on a side of the fourth core board facing the second outer copper layer, and the third water-absorbing resin is provided between the fifth copper layer and the second outer copper layer; a fourth water-absorbing resin is provided on a side of the fourth core board facing the second core board, and the fourth water-absorbing resin is located between the fourth copper layer and the fifth copper layer.

[0017] In one embodiment, the multilayer board also includes a fifth core board, which is located between the third core board and the second core board; a sixth copper layer is provided on a side of the fifth core board facing the third core board, and the first water-absorbing resin is provided between the second copper layer and the sixth copper layer; a fifth water-absorbing resin is provided on a side of the fifth core board facing the second core board, and the fifth water-absorbing resin is located between the third copper layer and the fourth copper layer.

[0018] In one embodiment, after step S50, the following steps are further included: electroplating: copper is plated on the inner wall of the through hole and the surface of the multilayer board.

[0019] The present invention also provides a PCB, which is prepared according to the above PCB manufacturing method, and the manufacturing method comprises the following steps:

[0020] S10, obtaining a multilayer board, the multilayer board comprising a first core board, a first water-absorbing resin, and a second core board which are stacked, wherein a first copper layer and a second copper layer are provided on the upper and lower surfaces of the first core board, and the second copper layer faces the second core board; a third copper layer and a fourth copper layer are provided on the upper and lower surfaces of the second core board, and the third copper layer faces the first core board, and the first water-absorbing resin is between the second copper layer and the third copper layer and is located in a preset opening area;

[0021] S20, drilling holes in the multilayer board corresponding to the preset opening areas to form through holes, wherein the through holes pass through the first water-absorbing resin;

[0022] S30, performing chemical copper deposition on the multilayer board, so that the first water-absorbing resin absorbs water and the hole wall of the through hole forms a copper deposition layer, wherein the copper deposition layer at least connects the first copper layer and the second copper layer, and connects the third copper layer and the fourth copper layer;

[0023] S40, performing a baking process on the multilayer board, the first water-absorbing resin expands toward the through hole and protrudes from the hole wall of the through hole to form a first protrusion, and the copper deposition layer attached to the first protrusion is cracked;

[0024] S50, removing the copper deposition layer attached to the first protrusion or the first protrusion to disconnect the second copper layer from the third copper layer.

[0025] The embodiment of the present application provides a PCB manufacturing method, by obtaining a multilayer board, setting a first copper layer and a second copper layer on the upper and lower surfaces of a first core board, setting a third copper layer and a fourth copper layer on the upper and lower surfaces of a second core board, a first water-absorbing resin is located between the second copper layer and the third copper layer, and the first water-absorbing resin corresponds to a preset opening area, and the structure of the multilayer board is set. Then, the multilayer board is drilled and chemically coppered, so that the copper-plated layer connects the first copper layer with the second copper layer, and the third copper layer with the fourth copper layer. Then, a baking operation is performed to crack the copper-plated layer attached to the first protrusion, and finally the first protrusion or the copper-plated layer attached to the first protrusion is removed, so as to achieve the purpose of disconnecting the second copper layer from the third copper layer, and then obtain two independent grids.

[0026] The technical solution of the present invention has a simple process flow and does not require the use of complex processes or sophisticated processing equipment, which greatly simplifies the production process of one-hole multi-network PCBs, improves the production versatility of one-hole multi-network PCBs, and realizes the high-density and refined design requirements of one-hole multi-network PCBs in a low-cost and high-efficiency manner, which is suitable for mass production of PCBs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0028] Figure 1 This is a flow chart of an embodiment of a PCB manufacturing method of the present application;

[0029] Figure 2 A schematic diagram of a multi-layer board structure after lamination in the PCB manufacturing method of this application;

[0030] Figure 3 This is a schematic diagram of the multilayer board structure after vias in the PCB manufacturing method of this application;

[0031] Figure 4 This is a schematic diagram of the structure of a multilayer board after chemical copper deposition treatment in the PCB manufacturing method of this application;

[0032] Figure 5 This is a schematic diagram of the structure of a multilayer board after baking in the PCB manufacturing method of this application;

[0033] Figure 6 This is a schematic diagram of the multilayer board structure after the protrusions are removed in the PCB manufacturing method of this application;

[0034] Figure 7 This is a schematic diagram of the multilayer board structure after removing the water-absorbing resin in the PCB manufacturing method of this application;

[0035] Figure 8 This is a schematic diagram of the structure of a multilayer board after electroplating in the PCB manufacturing method of this application;

[0036] Fig. 9 This is a schematic diagram of another multilayer board structure after lamination in the PCB manufacturing method of this application.

[0037] Description of Figure Numbers:

[0038]

[0039]

[0040] The realization of the purpose, functional features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. The above-mentioned drawings have shown clear embodiments of this application, which will be described in more detail later. These drawings and textual descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0041] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0042] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. Optionally, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context in the specific embodiment.

[0043] It should be understood that, although the various steps in the flowchart in the embodiment of the present application are displayed in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and it can be performed in other orders. Moreover, at least a portion of the steps in the figure may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0044] It should be noted that in this article, step codes such as S10 and S20 are used for the purpose of expressing the corresponding content more clearly and concisely, and do not constitute a substantial limitation on the sequence. When implementing the step, those skilled in the art may execute S20 first and then S10, etc., but these should all be within the scope of protection of this application.

[0045] The invention provides a PCB manufacturing method. Figure 1 is a flow chart of the PCB preparation method of the present invention, Figures 2 to 8 The following are the structural schematic diagrams of the PCB preparation process of the present invention, Fig. 9 This is a schematic diagram of the structure of another multilayer board after lamination.

[0046] In the embodiment of the present invention, please refer to Figure 1 and Figure 2 , including the following steps:

[0047] Step S10, obtaining a multilayer board 10, wherein the multilayer board 10 includes a first core board 110, a first water-absorbing resin 210 and a second core board 120 which are stacked, wherein the upper and lower surfaces of the first core board 110 are respectively provided with a first copper layer 310 and a second copper layer 320, and the second copper layer 320 faces the second core board 120; the upper and lower surfaces of the second core board 120 are respectively provided with a third copper layer 330 and a fourth copper layer 340, and the third copper layer 330 faces the first core board 110, and the first water-absorbing resin 210 is between the second copper layer 320 and the third copper layer 330, and is located within a preset opening area.

[0048] In the process of manufacturing PCB, it is necessary to determine in advance the multilayer board 10 and determine the structure of the multilayer board 10, so as to facilitate subsequent operations. Figure 2In the multilayer board 10, the first core board 110 and the second core board 120 are stacked, wherein the first core board 110 is provided with a first copper layer 310 and a second copper layer 320 on the upper and lower surfaces, respectively, and the second core board 120 is provided with a third copper layer 330 and a fourth copper layer 340 on the upper and lower surfaces, respectively, and the first water-absorbing resin 210 is located between the second copper layer 320 and the third copper layer 330, and corresponds to a preset opening position, so that a hole is drilled through the first water-absorbing resin 210, and the first water-absorbing resin 210 can be exposed.

[0049] The first copper layer 310, the second copper layer 320, the third copper layer 330 and the fourth copper layer 340 can be made of copper foil. It should be noted that when three, four or more networks are made, the number of the first core board 110 and / or the second core board 120 can be multiple. Similarly, the first copper layer 310 and the second copper layer 320 are respectively provided on the upper and lower surfaces of the first core board 110, and the third copper layer 330 and the fourth copper layer 340 are respectively provided on the upper and lower surfaces of the second core board 120. In other words, the multilayer board 10 can be provided with multiple first core boards 110 and / or second core boards 120 to form multiple networks.

[0050] The first water-absorbing resin 210 has good water absorption and can be dissolved and eliminated by the preset elimination solution through chemical reaction. The first water-absorbing resin 210 is a new functional polymer material, which has a high water absorption function of absorbing water hundreds to thousands of times heavier than itself, and has excellent water retention performance. There are many materials for the water-absorbing resin. In one embodiment, the first water-absorbing resin 210 includes a hydrogel, and the preset elimination solution can be an alkaline solution. Further, in one embodiment, the hydrogel includes one or both of sodium polyacrylate and polyacrylamide.

[0051] Please refer to Figure 1 and Figure 3 In step S20 , drilling is performed in the multilayer board 10 corresponding to the preset opening area to form a through hole 10 a , and the through hole 10 a passes through the first water-absorbing resin 210 .

[0052] Please refer to Figure 3 , a drilling operation is performed on the multilayer board 10, and holes are drilled in the pre-opening area corresponding to the multilayer board 10 according to the position and size of the opening to form a through hole 10a, and the through hole 10a passes through the first water-absorbing resin 210 so that the first water-absorbing resin 210 is exposed on the hole wall surface of the through hole 10a, so that the first water-absorbing resin 210 can contact with the liquid, so that the first water-absorbing resin 210 can absorb the liquid.

[0053] Please refer to Figure 1 and Figure 4In step S30, chemical copper plating is performed on the multilayer board 10 so that the first water-absorbing resin 210 absorbs water and a copper plating layer 400 is formed on the hole wall of the through hole 10a. The copper plating layer 400 at least connects the first copper layer 310 and the second copper layer 320, and the third copper layer 330 and the fourth copper layer 340.

[0054] Please refer to Figure 4 After the drilling operation is completed, the multilayer board 10 is subjected to a chemical copper deposition operation. The multilayer board 10 is placed in a copper deposition solution for copper deposition. Water contacts the first water-absorbing resin 210 through the through hole 10a and is absorbed by the first water-absorbing resin 210. The first water-absorbing resin 210 absorbs the liquid. At the same time, a copper deposition layer 400 is deposited on the hole wall surface of the through hole 10a. The thickness of the copper deposition layer 400 is relatively small, which can be 0.3 microns to 0.5 microns.

[0055] It is understandable that the copper layer 400 may cover the entire hole wall surface of the through hole 10a, or may not cover the entire hole wall surface of the through hole 10a. Figure 4 The copper layer 400 at least connects the first copper layer 310 and the second copper layer 320, and the third copper layer 330 and the fourth copper layer 340, so that the copper layer 400 attached to the first core board 110 forms a network with the first copper layer 310 and the second copper layer 320, and the copper layer 400 attached to the second core board 120 forms another network with the third copper layer 330 and the fourth copper layer 340.

[0056] To make the two networks independent of each other, refer to Figure 5 In step S40, the multilayer board 10 is baked, and the first water-absorbing resin 210 expands toward the through hole 10a and protrudes from the hole wall of the through hole 10a to form a first protrusion 211, and the copper plating layer 400 to which the first protrusion 211 is attached is cracked.

[0057] In step S40, please refer to Figure 5 By baking the board, the multilayer board 10 is heated at a high temperature, and the water absorbed by the first water-absorbing resin 210 evaporates due to the heat, making the first water-absorbing resin 210 fluffy and expanding and protruding into the through hole 10a, forming a first protrusion 211. The first protrusion 211 lifts the copper-plated layer 400 attached to the first water-absorbing resin 210, so that the copper-plated layer 400 is cracked, which is convenient for the subsequent disconnection operation of the copper-plated layer 400, so as to realize the mutual independence of the two networks. The copper-plated layer 400 in the cracked part is an incomplete copper layer, and part of the first protrusion 211 can be exposed.

[0058] The temperature of the baking plate can be 100°C to 125°C as long as it is greater than the evaporation temperature of water, and the baking time is 10 minutes to 20 minutes. In one embodiment, the baking temperature of the multilayer board 10 is 110°C, and the baking time is 15 minutes, so as to achieve the volume expansion of the first water-absorbing resin 210, reduce energy consumption, and reduce production costs.

[0059] Please refer to Figure 1 and Figure 6 , step S50, removing the copper deposition layer 400 attached to the first protrusion 211 or the first protrusion 211 to disconnect the second copper layer 320 from the third copper layer 330.

[0060] Please refer to Figure 6 There are many ways to remove the copper layer 400 attached to the first protrusion 211 or the first protrusion 211, which can be mechanical removal or chemical removal. The specific method will be described in the following content. By removing the first protrusion 211 or the copper layer 400 attached to the first protrusion 211, the copper layer 400 attached to the first protrusion 211 is removed, so that the second copper layer 320 and the third copper layer 330 are disconnected, that is, the two networks are independent of each other, there is no conduction between the two networks, and there is no electrical connection between the two networks.

[0061] The PCB manufacturing method provided by the present invention is to obtain a multilayer board 10, set a first copper layer 310 and a second copper layer 320 on the upper and lower surfaces of a first core board 110, set a third copper layer 330 and a fourth copper layer 340 on the upper and lower surfaces of a second core board 120, and a first water-absorbing resin 210 is located between the second copper layer 320 and the third copper layer 330, and make the first water-absorbing resin 210 correspond to a preset opening area, and set the structure of the multilayer board 10. Then, the multilayer board 10 is drilled and chemically coppered, so that the copper-plated layer 400 connects the first copper layer 310 with the second copper layer 320, and the third copper layer 330 with the fourth copper layer 340. Then, a baking operation is performed to crack the copper-plated layer 400 attached to the first protrusion 211, and finally the first protrusion 211 or the copper-plated layer 400 attached to the first protrusion 211 is removed, so as to achieve the purpose of disconnecting the second copper layer 320 from the third copper layer 330, and then obtain two independent grids.

[0062] The technical solution of the present invention has a simple process flow and does not require the use of complex processes or sophisticated processing equipment, which greatly simplifies the production process of one-hole multi-network PCBs, improves the production versatility of one-hole multi-network PCBs, and realizes the high-density and refined design requirements of one-hole multi-network PCBs in a low-cost and high-efficiency manner, which is suitable for mass production of PCBs.

[0063] Please refer to Figures 5 and 6In one embodiment, the step of removing the copper deposition layer 400 attached to the first protrusion 211 or the first protrusion 211 specifically includes the following steps:

[0064] ablating the first protrusion 211 or the copper layer 400 attached to the first protrusion 211 by laser to disconnect the second copper layer 320 from the third copper layer 330; and / or,

[0065] The multilayer board 10 is cleaned with an alkaline solution to remove the first water absorbing resin 210 .

[0066] The copper layer 400 attached to the first protrusion 211 can be removed by laser ablation, so that the copper layer 400 connecting the second copper layer 320 and the third copper layer 330 is removed, and the second copper layer 320 and the third copper layer 330 are disconnected. Figure 6 , remove the first protrusion 211 protruding from the inner wall of the through hole 10a, and remove the copper layer 400 attached to the first protrusion 211 together, so as to disconnect the second copper layer 320 and the third copper layer 330.

[0067] Please refer to Figure 5 , since the first water-absorbing resin expands in volume after absorbing water and baking the board, it protrudes into the through hole 10a, causing the copper deposition layer 400 to crack. The copper deposition layer 400 in the cracked part is an incomplete copper layer, and part of the first water-absorbing resin 210, i.e., the first protrusion 211, can be exposed. Therefore, by soaking and cleaning with an alkaline solution, the first water-absorbing resin 210 (including the first protrusion 211) located on the multilayer board 10 is washed away, so that the copper deposition layer 400 attached to the first water-absorbing resin 210 loses its attachment body and falls off, thereby realizing the disconnection of the second copper layer 320 and the third copper layer 330.

[0068] Alternatively, laser ablation may be performed first to remove the copper layer 400 or the first protrusion 211 attached to the first water-absorbing resin 210, and then the first water-absorbing resin 210 may be washed away, thereby completely removing the first water-absorbing resin 210, so that the second copper layer 320 and the third copper layer 330 are completely disconnected and separated. Alternatively, the first water-absorbing resin 210 may be cleaned with an alkaline solution first, and then laser ablation may be performed to remove the copper layer 400 attached to the first water-absorbing resin 210.

[0069] There are many ways to set the first water-absorbing resin 210. Figure 2 In one embodiment, the step S10 specifically includes the following steps:

[0070] The first water-absorbing resin 210 is disposed on a side of the second copper layer 320 facing the third copper layer 330 or a side of the third copper layer 330 facing the second copper layer 320;

[0071] The first core board 110 and the second core board 120 are stacked and pressed together to form the multilayer board 10 .

[0072] Please refer to Figure 2 , the first water-absorbing resin 210 can be firstly arranged on the surface of the second copper layer 320 or the third copper layer 330, or the first water-absorbing resin 210 can be sandwiched between the second copper layer 320 and the third copper layer 330 for lamination. The first water-absorbing resin 210 can be arranged on the surface of the second copper layer 320 or the third copper layer 330 by silk-screen printing, and the number of the first water-absorbing resin 210 can be multiple, and the first water-absorbing resin 210 is arranged on the surface of the second copper layer 320 and the third copper layer 330. After the multilayer board 10 is pressed, the structure of the multilayer board 10 is the first copper layer 310, the first core board 110, the second copper layer 320, the first water-absorbing resin 210, the third copper layer 330, the second core board 120 and the fourth copper layer 340 in sequence.

[0073] Please refer to Figure 2 In one embodiment, the multilayer board 10 further includes a third core board 130, and the step S10 specifically includes the following steps:

[0074] The third core plate 130 is a prepreg, and the first water-absorbing resin 210 is embedded in one side of the third core plate 130;

[0075] The first core board 110 , the third core board 130 , and the second core board 120 are stacked in sequence and pressed to form the multilayer board 10 .

[0076] The prepreg is one of the main materials used in the production of the multilayer board 10, and is mainly composed of resin and reinforcing material. In an optional embodiment, the prepreg is a glass fiber cloth as a reinforcing material. Figure 2 The semi-cured sheet is provided with an embedding groove for accommodating the first water-absorbing resin 210. The embedding groove can be a through groove or a blind groove. By arranging the first water-absorbing resin 210 in the embedding groove, the semi-cured sheet is clamped between the second copper layer 320 and the third copper layer 330 and pressed, thereby realizing the arrangement of the first water-absorbing resin 210.

[0077] Please continue to refer to Figure 2 In one embodiment, the multilayer board 10 further includes a first outer copper layer 510 and a second outer copper layer 520, and the step S10 includes the following steps:

[0078] The first outer copper layer 510 , the first core board 110 , the third core board 130 , the second core board 120 and the second outer copper layer 520 are stacked in sequence and pressed.

[0079] To improve the transmission performance of PCB, please refer to Figure 2The first outer copper layer 510 is located on the side of the first copper layer 310 away from the first core board 110, and the second outer copper layer 520 is located on the side of the fourth copper layer 340 away from the second core board 120. After pressing, the structure of the multilayer board 10 is the first outer copper layer 510, the first copper layer 310, the first core board 110, the second copper layer 320, the third core board 130 (including the first water-absorbing resin 210), the third copper layer 330, the second core board 120, the fourth copper layer 340, and the second outer copper layer 520.

[0080] In order to prevent the first outer copper layer 510 from being connected to the first copper layer 310 and the second outer copper layer 520 from being connected to the fourth copper layer 340, please refer to Figure 2 In one embodiment, the first outer copper layer 510 and the first copper layer 310 are provided with a second water-absorbing resin 220 in the preset opening area, and the second outer copper layer 520 and the fourth copper layer 340 are provided with a third water-absorbing resin 230 in the preset opening area.

[0081] Please continue to refer to Figure 2 , by arranging the second water-absorbing resin 220 between the first outer copper layer 510 and the first copper layer 310, and arranging the third water-absorbing resin 230 between the second outer copper layer 520 and the fourth copper layer 340, after chemical copper deposition and plate baking operations, the second water-absorbing resin 220 and the third water-absorbing resin 230 expand in volume and protrude from the hole wall of the through hole 10a to form a second protrusion 221 and a third protrusion 231 respectively, and then removing the copper deposition layer 400 or the second protrusion 221 attached to the second protrusion 221, and removing the copper deposition layer 400 or the third protrusion 231 attached to the third protrusion 231, so that the first outer copper layer 510 and the first copper layer 310, and the second outer copper layer 520 and the fourth copper layer 340 are independent of each other and not conductive.

[0082] In addition to the network, the multilayer board 10 can also be provided with other transmission layers. Figure 2 In one embodiment, the multilayer board 10 further includes a fourth core board 140, the fourth core board 140 is located between the fourth copper layer 340 and the second outer copper layer 520, a fifth copper layer 350 is provided on a side of the fourth core board 140 facing the second outer copper layer 520, and the third water-absorbing resin 230 is provided between the fifth copper layer 350 and the second outer copper layer 520; a fourth water-absorbing resin 240 is provided on a side of the fourth core board 140 facing the second core board 120, and the fourth water-absorbing resin 240 is located between the fourth copper layer 340 and the fifth copper layer 350.

[0083] Please continue to refer to Figure 2, the fourth water-absorbing resin 240 and the fifth copper layer 350 are respectively disposed on opposite sides of the fourth core board 140, and the fourth water-absorbing resin 240 is located on the side of the fourth core board 140 away from the fifth copper layer 350, thereby increasing the distance between the fourth copper layer 340 and the fifth copper layer 350. After the multilayer board 10 is subjected to the chemical copper deposition and board baking operations, the fourth water-absorbing resin 240 expands in volume and protrudes from the hole wall of the through hole 10a to form fourth protrusions 241, and then the connection between the fourth copper layer 340 and the fifth copper layer 350 is disconnected, thereby realizing the mutual independence between the network and the fifth copper layer 350.

[0084] Please refer to Fig. 9 In one embodiment, the multilayer board 10 also includes a fifth core board 150, and the fifth core board 150 is located between the third core board 130 and the second core board 120. The fifth core board 150 is provided with a sixth copper layer 360 on the side facing the third core board 130, and the first water-absorbing resin 210 is provided between the second copper layer 320 and the sixth copper layer 360; the fifth core board 150 is provided with a fifth water-absorbing resin 250 on the side facing the second core board 120, and the fifth water-absorbing resin 250 is located between the third copper layer 330 and the fourth copper layer 340.

[0085] Please continue to refer to Fig. 9 , the fifth core board 150 is located between the first core board 110 and the second core board 120, the sixth copper layer 360 is arranged on the side of the fifth core board 150 facing the first core board 110, and the fifth water-absorbing resin 250 is arranged on the side facing the second core board 120. At this time, the structure of the multiple boards is: the first copper layer 310, the first core board 110, the second copper layer 320, the first water-absorbing resin 210, the sixth copper layer 360, the fifth core board 150, the fifth water-absorbing resin 250, the third copper layer 330, the third core board 130, and the fourth copper layer 340. After the chemical copper deposition and board baking operations, the volume of the fifth water-absorbing resin 250 expands and protrudes from the hole wall of the through hole 10a to form a fifth protrusion, and then the connection between the sixth copper layer 360 and the third copper layer 330 is disconnected, so as to realize the mutual independence between the network and the third copper layer 330.

[0086] Those skilled in the art can imagine that the materials of the second water-absorbing resin 220, the third water-absorbing resin 230, the fourth water-absorbing resin 240 and the fifth water-absorbing resin 250 can be selected with reference to the first water-absorbing resin 210, and the specific method of removing the second protrusion 221, the copper-plated layer 400 attached to the second protrusion 221, the third protrusion 231, the copper-plated layer 400 attached to the third protrusion 231, the fourth protrusion 241, the copper-plated layer 400 attached to the fourth protrusion 241, the fifth protrusion and the copper-plated layer 400 attached to the fifth protrusion can refer to the step of removing the first protrusion 211 or the copper-plated layer 400 attached to the first protrusion 211, which has the beneficial effects brought by the technical solutions of the corresponding embodiments and will not be repeated here one by one.

[0087] After disconnecting from multiple networks, refer to Figure 8 In one embodiment, the method further comprises the following steps:

[0088] Electroplating: Copper is plated on the inner wall of the through hole 10 a and the surface of the multilayer board 10 .

[0089] Please continue to refer to Figure 8 The electroplating operation is used to copper plate the copper layer 400 and the periphery of the inner wall of the through hole 10a of the multilayer board 10, thereby increasing the thickness of the copper layer 400 and the periphery of the through hole 10a. In addition, since the multilayer board 10 is provided with a first outer copper layer 510 and a second outer copper layer 520, the surface of the first outer copper layer 510 and the second outer copper layer 520 is copper plated by electroplating, and the seventh copper layer 370 and the eighth copper layer 380 are plated on the surface of the first outer copper layer 510 and the second outer copper layer 520, respectively.

[0090] The present application also provides a PCB, which includes a via and a plurality of network space structures and can be prepared by the above-mentioned PCB manufacturing method. The specific preparation process refers to the above-mentioned PCB manufacturing method embodiments and will not be described one by one here.

[0091] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0092] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0093] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, 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 PCB manufacturing method, characterized in that: The method comprises the following steps: S10, obtaining a multilayer board (10), the multilayer board (10) comprising a first core board (110), a first water-absorbing resin (210), and a second core board (120) which are stacked, the first core board (110) having a first copper layer (310) and a second copper layer (320) respectively disposed on upper and lower surfaces, the second copper layer (320) facing the second core board (120); the second core board (120) having a third copper layer (330) and a fourth copper layer (340) respectively disposed on upper and lower surfaces, the third copper layer (330) facing the first core board (110), the first water-absorbing resin (210) being between the second copper layer (320) and the third copper layer (330), and being located in a preset opening area; S20, drilling holes in the multilayer board (10) corresponding to the preset opening area to form through holes (10a), wherein the through holes (10a) pass through the first water-absorbing resin (210); S30, performing chemical copper deposition on the multilayer board (10), so that the first water-absorbing resin (210) absorbs water and the hole wall of the through hole (10a) forms a copper deposition layer (400), wherein the copper deposition layer (400) at least connects the first copper layer (310) and the second copper layer (320), and connects the third copper layer (330) and the fourth copper layer (340); S40, performing a board baking process on the multilayer board (10), wherein the water absorbed by the first water-absorbing resin (210) evaporates due to heat, so that the first water-absorbing resin (210) becomes fluffy and expands toward the through hole (10a) to protrude from the hole wall of the through hole (10a) to form a first protrusion (211), and the copper deposition layer (400) attached to the first protrusion (211) becomes cracked; S50, removing the copper deposition layer (400) attached to the first protrusion (211) or the first protrusion (211), so as to disconnect the second copper layer (320) from the third copper layer (330).

2. The PCB manufacturing method according to claim 1, characterized in that: The step S50 specifically includes the following steps: ablating the first protrusion (211) or the copper deposition layer (400) attached to the first protrusion (211) by laser to disconnect the second copper layer (320) from the third copper layer (330); and / or, The multilayer board (10) is cleaned with an alkaline solution to remove the first water absorbing resin (210).

3. The PCB manufacturing method according to claim 1, characterized in that: The step S10 specifically includes the following steps: The first water-absorbing resin (210) is arranged on a side of the second copper layer (320) facing the third copper layer (330) or on a side of the third copper layer (330) facing the second copper layer (320); The first core board (110) and the second core board (120) are stacked and pressed together to form the multilayer board (10).

4. The PCB manufacturing method according to claim 1, characterized in that: The multilayer board (10) further comprises a third core board (130), and the step S10 specifically comprises the following steps: The third core plate (130) is a prepreg, and the first water-absorbing resin (210) is embedded on one side of the third core plate (130); The first core board (110), the third core board (130) and the second core board (120) are stacked in sequence and pressed to form the multilayer board (10).

5. The PCB manufacturing method according to claim 4, characterized in that: The multilayer board (10) further comprises a first outer copper layer (510) and a second outer copper layer (520), and the step S10 comprises the following steps: The first outer copper layer (510), the first core board (110), the third core board (130), the second core board (120), and the second outer copper layer (520) are stacked in sequence and pressed.

6. The PCB manufacturing method according to claim 5, characterized in that: The first outer copper layer (510) and the first copper layer (310) are provided with a second water-absorbing resin (220) in the preset opening area, and the second outer copper layer (520) and the fourth copper layer (340) are provided with a third water-absorbing resin (230) in the preset opening area.

7. The PCB manufacturing method according to claim 6, characterized in that: The multilayer board (10) further comprises a fourth core board (140), the fourth core board (140) being located between the fourth copper layer (340) and the second outer copper layer (520); a fifth copper layer (350) is provided on a side of the fourth core board (140) facing the second outer copper layer (520), and the third water-absorbing resin (230) is provided between the fifth copper layer (350) and the second outer copper layer (520); a fourth water-absorbing resin (240) is provided on a side of the fourth core board (140) facing the second core board (120), and the fourth water-absorbing resin (240) is located between the fourth copper layer (340) and the fifth copper layer (350).

8. The PCB manufacturing method according to claim 7, characterized in that: The multilayer board (10) further comprises a fifth core board (150), wherein the fifth core board (150) is located between the third core board (130) and the second core board (120); a sixth copper layer (360) is provided on a side of the fifth core board (150) facing the third core board (130), and the first water-absorbing resin (210) is provided between the second copper layer (320) and the sixth copper layer (360); a fifth water-absorbing resin (250) is provided on a side of the fifth core board (150) facing the second core board (120), and the fifth water-absorbing resin (250) is located between the third copper layer (330) and the fourth copper layer (340).

9. The PCB manufacturing method according to claim 1, characterized in that: After step S50, the following steps are also included: Electroplating: copper is plated on the inner wall of the through hole (10a) and the surface of the multilayer board (10).

10. A PCB, characterized in that: The PCB is prepared according to the PCB manufacturing method according to any one of claims 1 to 9.

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