Method, device and printed circuit board for realizing local large current on inner layer of PCB (Printed Circuit Board)

Abstract

The invention relates to a method and a device for realizing local large current conduction of an inner layer of a PCB (Printed Circuit Board) and a printed circuit board, provides a new design mode on the aspect of an inner layer production process, and overcomes the defect that a core board material cannot realize local thick copper through the change of a process flow before the inner layer production so as to meet the thick copper large current requirement of an AI chip for a local area; and the machinability and the consistency of the inner layer pattern of the PCB are synchronously ensured, so that the stable operation of AI computing power equipment and the reliability of data are realized, and the thickness and the cost of a PCB product are reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of PCB manufacturing, and specifically to a method and device for achieving local high current flow in the inner layer of a PCB, and a printed circuit board. Background Art

[0002] With the continuous advancement of AI technology, especially the application of high-performance AI chips, the energy consumption problem of equipment has become increasingly prominent. High-performance AI chips generate a lot of heat during operation. If the heat cannot be dissipated in a timely and effective manner, it will not only affect the stable operation of the equipment, but also shorten its service life, restricting the further growth of AI computing power.

[0003] AI applications have very high requirements for chip performance and reliability. In order to complete the training task of a large model, thousands or even tens of thousands of computing cards are usually required to be cascaded to provide sufficient computing power. If there is a problem with one card, the training of the entire large model will be affected. This requires PCB products to not only be able to withstand higher current flow capacity, but also have better heat dissipation performance to ensure the stability and reliability of the entire system. The improvement of AI computing power has higher requirements for the flow and heat dissipation of PCB products. The main reason is that the development of AI technology has led to an increase in equipment energy consumption, which in turn has put forward higher requirements for heat dissipation and power distribution.

[0004] The core material used in the inner layer of traditional circuit boards can only have one thickness for the same layer, and the raw material core board cannot achieve different thicknesses in the same layer. Limited by the characteristics of the raw materials, during the early design of the PCB, customers will only choose the final copper thickness required based on the requirements of current flow and heat dissipation. At the same time, the high current flow and heat dissipation required by AI chips are only in local areas, which leads to the use of thick copper for the entire layer, resulting in increased material costs, as well as the difficulty of the processing technology brought about by thick copper, which leads to increased costs. Summary of the invention

[0005] In view of the above problems, the embodiments of the present invention provide a method, device and printed circuit board for realizing local high current flow in the inner layer of PCB, which is used to solve the problem that in the prior art, due to the limitations and characteristics of raw materials, in the early design of PCB, customers will only select the required final copper thickness based on the requirements of flow and heat dissipation. At the same time, the high current flow and heat dissipation required by AI chips are only in local areas, which leads to the increase of material cost due to the use of thick copper in the whole layer, as well as the difficulty of processing technology caused by thick copper, which leads to the problem of increased cost.

[0006] According to one aspect of an embodiment of the present invention, a method for locally passing a large current through an inner layer of a PCB is provided, the method comprising: Punching a core board, obtaining the core board, and drilling holes aligned with the inner layer pattern around the core board by mechanical drilling; Core plate lamination, attaching a photosensitive film to the surface of the core plate; Core board exposure, selectively irradiating a preset area of ​​the core board with ultraviolet light to form a core board pattern on the surface of the core board; Opening holes in the photosensitive film, removing the photosensitive film in the unexposed area of ​​the core board, so that the unexposed area leaks out of the copper surface, and defining the unexposed area as a thickened area; Core plate electroplating, fixing the core plate peripheral side by a core plate fixture, and plating thick copper on the thickened area by electroplating after the core plate is fixed; The core board is stripped of the film, and the photosensitive film on the surface of the preset area of ​​the core board is removed to expose the preset area to form a thickened inner layer board.

[0007] In some optional embodiments, the core board clamp includes two clamping jaws arranged opposite to each other or four clamping jaws arranged along the four sides of the core board, and the clamping jaws are provided with clamping grooves matching the thickness of the core board. The core board clamp is used to clamp the two sides or four sides of the core board to fix the core board.

[0008] In some optional embodiments, after the core plate film removal step, the method further includes: Inner layer circuit production: producing inner layer circuits on the thickened inner layer board; Layer pressing: according to the alignment holes of the thickened inner layer boards, a plurality of the thickened inner layer boards are pressed into a PCB multilayer board.

[0009] In some optional embodiments, the inner layer circuit manufacturing specifically includes: Inner lamination film: a photosensitive film is attached to the surface of the thickened multilayer board; Inner layer exposure: transferring the inner layer circuit to the photosensitive film of the thickened multilayer board through selective ultraviolet light irradiation; Inner layer development: removing the photosensitive film in the unexposed area of ​​the thickened multilayer board, so that the copper surface of the unexposed area is exposed; Inner layer etching: etching away the exposed copper surface of the thickened multilayer board; Inner layer stripping: removing the exposed photosensitive film of the thickened multilayer board.

[0010] In some optional embodiments, after the inner layer is stripped, the method further comprises: AOI circuit inspection: Scan and obtain the inner circuit of the thickened multilayer board and compare it with the preset data graphics, record suspected defects and screen out defective thickened multilayer boards.

[0011] In some optional embodiments, the lamination process specifically includes: According to the alignment holes of the thickened inner layer board, the thickened inner layer boards are aligned by rivets or positioning; and the plurality of thickened inner layer boards and the PP board are pressed together by high temperature and high pressure to form a PCB multilayer board.

[0012] In some optional embodiments, before the inner layer circuit is manufactured, the method further includes: Thickened inner layer board cleaning: clean the remaining foreign matter and oil stains on the thickened inner layer board by water washing.

[0013] In some optional embodiments, before punching holes in the core plate, the process further includes: Core board cutting: The raw material board is separated into core boards according to the chip size by a dividing machine.

[0014] According to another aspect of an embodiment of the present invention, a device for locally passing a large current through an inner layer of a PCB is provided. The device is used to execute the above-mentioned method for locally passing a large current through an inner layer of a PCB to manufacture a printed circuit board.

[0015] According to another aspect of an embodiment of the present invention, there is provided a printed circuit board, which is manufactured by executing the above-mentioned method for locally passing a large current through the inner layer of the PCB by the above-mentioned device for locally passing a large current through the inner layer of the PCB.

[0016] The method, device and printed circuit board for achieving local high current flow in the inner layer of a PCB of the present invention have the following beneficial effects: the present invention obtains a core board by performing core board punching on the core board in sequence, and drills holes aligned with the inner layer pattern around the core board by mechanical drilling; core board lamination, attaching a photosensitive film to the surface of the core board; core board exposure, selectively irradiating a preset area of ​​the core board with ultraviolet light to form a core board pattern on the surface of the core board; photosensitive film opening, removing the photosensitive film in the unexposed area of ​​the core board, allowing the copper surface of the unexposed area to leak out, and defining the unexposed area as a thickened area; core board electroplating, fixing the peripheral side of the core board by a core board clamp, and plating the thickened area with thick copper by electroplating after the core board is fixed; core board film stripping, removing the photosensitive film on the surface of the preset area of ​​the core board, exposing the preset area to form a thickened inner layer board. The present invention proposes a new design method in the inner layer production process. Before the inner layer is produced, the defect of the core board material that cannot achieve local thick copper is compensated by changing the process flow, so as to meet the AI ​​chip's demand for thick copper and large current in local areas, and simultaneously ensure the machinability and consistency of the PCB inner layer graphics, so as to achieve stable operation of AI computing equipment and data reliability, and reduce the thickness and cost of PCB products.

[0017] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation mode of the present invention is specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings: Figure 1 A schematic diagram of a process for implementing a method for locally passing a large current through an inner layer of a PCB according to Embodiment 1 of the present invention is shown; Figure 2 The process flow chart after the core plate film removal step of Example 1 provided by the present invention is shown; Figure 3 A schematic diagram of a core plate in step 110 of embodiment 1 provided by the present invention is shown; Figure 4 A schematic diagram of a core plate in step 120 of embodiment 1 provided by the present invention is shown; Figure 5 A schematic diagram of a core plate in step 140 of embodiment 1 provided by the present invention is shown; Figure 6 A schematic diagram of a core plate in step 150 of embodiment 1 provided by the present invention is shown; Figure 7 A schematic diagram of a core plate in step 160 of embodiment 1 provided by the present invention is shown; Among them, 1. core board; 2. alignment holes; 3. photosensitive film; 4. preset area; 5. thickened area; 6. core board fixture; 7. thick copper; 8. thickened inner layer board. DETAILED DESCRIPTION

[0019] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0020] In the prior art, the traditional PCB process flow is cutting → inner layer lamination → inner layer exposure → inner layer etching → inner layer AOI → lamination →… It can be seen that the thickness of the core board material used in the inner layer of the traditional circuit board can only be one thickness for the same layer, and the raw material core board cannot achieve different thicknesses in the same layer. Limited by the characteristics of the raw materials, during the early design of the PCB, customers will only choose the final copper thickness required based on the requirements of current flow and heat dissipation. In terms of the actual function of the product, the large current flow and heat dissipation required by the AI ​​chip are only in local areas, which leads to the use of thick copper for the entire layer, resulting in increased material costs, as well as the difficulty of the processing technology brought about by thick copper, which will increase costs.

[0021] In view of the above-mentioned shortcomings, we break the traditional inner layer production process thinking and propose a new design method for the inner layer production process. Before the inner layer is produced, the process flow is changed to make up for the defect that the core board material cannot achieve local thick copper, to meet the AI ​​computing chip's demand for thick copper and high current in local areas, and to simultaneously ensure the machinability and consistency of the PCB inner layer graphics, to achieve the stable operation of the AI ​​computing equipment and the reliability of the data, and to reduce the thickness and cost of the PCB product. For specific solutions, please refer to the following embodiments.

[0022] Embodiment 1, See also Figure 1-7 According to one aspect of an embodiment of the present invention, a method for achieving local high current flow in the inner layer of a PCB is provided, which is used to manufacture a thickened copper core board. The method comprises: 110, core plate drilling, obtain the core plate, and drill holes aligned with the inner layer pattern around the core plate by mechanical drilling; in step 110, refer to Figure 3 , Icon 1 is the core board, Icon 2 is the alignment hole. Specifically, mechanical drilling is used to drill alignment holes around the core board that match the inner layer pattern to ensure that the pattern required by the core board matches the actual product requirement position. Since the thickness of each core board and the thickness inside a single core board are different after the core board is thickened, alignment holes are required for positioning and pressing when multiple core boards are pressed together.

[0023] 120, core board lamination, attaching a photosensitive film to the surface of the core board; in step 120, see Figure 4 , Icon 1 is the core board, Icon 2 is the photosensitive film. A layer of photosensitive film is formed on the copper surface of the core board where the positioning holes have been drilled, in preparation for exposure.

[0024] 130, core board exposure, selectively irradiating a preset area of ​​the core board with ultraviolet light to form a core board pattern on the surface of the core board; in step 130, the design pattern is transferred to the photosensitive film on the core board where the positioning holes have been drilled by selective irradiation with ultraviolet light; the core board pattern is the pattern of the unexposed area.

[0025] 140, opening a hole in the photosensitive film, removing the photosensitive film in the unexposed area of ​​the core board, so that the unexposed area leaks out of the copper surface, and defining the unexposed area as a thickened area; in step 140, see Figure 3 , icon 1 is the core board, icon 4 is the preset area, and icon 5 is the thickened area. This step is to wash away the photosensitive film in the unexposed area of ​​the core board where the positioning holes have been drilled, expose the copper surface, and expose the pattern and position that need to be thickened.

[0026] 150, core plate electroplating, fix the core plate peripheral side by a core plate fixture, and after the core plate is fixed, plate the thickened area with thick copper by electroplating; in step 150, refer to Figure 3 , icon 6 is a core board fixture, and icon 7 is thick copper. Use a core board fixture to fix the core board to solve the problem that the core board is too thin to be electroplated. The core board fixture includes two clamping jaws arranged opposite to each other or four clamping jaws arranged along the four sides of the core board, and the clamping jaws are provided with clamping grooves matching the thickness of the core board, and the core board is clamped on two sides or four sides of the core board by the core board fixture to fix the core board. Among them, the clamping space of the two clamping jaws or four clamping jaws of the core board clamp is adjustable, and the height of the clamping groove is adjustable by rotating the bolt to adapt to core boards of different thicknesses and sizes. By electroplating the core board, the thickened area of ​​the core board is plated with thick copper; the local thick copper of the core board is achieved to meet the high current demand of thick copper in the local area of ​​the AI ​​computing power chip, and simultaneously ensure the machinability and consistency of the inner layer graphics of the PCB.

[0027] 160, core board film removal, removing the photosensitive film on the surface of the preset area of ​​the core board, exposing the preset area, forming a thickened inner layer board. In step 160, the exposed photosensitive film of the core board is removed, so that the surface of the core board forms a thickened inner layer board 8 with a convex and uneven copper surface, see Figure 7 .

[0028] The present invention proposes a new design method in the inner layer production process. Before the inner layer is produced, the defect of the core board material that cannot achieve local thick copper is compensated by changing the process flow, so as to meet the AI ​​chip's demand for thick copper and large current in local areas, and simultaneously ensure the machinability and consistency of the PCB inner layer graphics, so as to achieve stable operation of AI computing equipment and data reliability, and reduce the thickness and cost of PCB products.

[0029] In some optional embodiments, the core plate clamp includes two clamping jaws arranged opposite to each other or four clamping jaws arranged along four sides of the core plate, the clamping jaws are provided with clamping grooves matching the thickness of the core plate, and the core plate is clamped on two sides or four sides of the core plate by the core plate clamp to fix the core plate. In this embodiment, the clamping space of the two clamping jaws or four clamping jaws of the core plate clamp is adjustable, and the height of the clamping groove is adjustable by rotating the bolt to adapt to core plates of different thicknesses and sizes.

[0030] In some optional embodiments, after the core plate film removal step, see Figure 2 , also includes: 210, inner layer circuit production: inner layer circuits are produced on the thickened inner layer board; in step 210, inner layer circuit production specifically includes: inner layer lamination: attaching a photosensitive film to the surface of the thickened multilayer board; inner layer exposure: transferring the inner layer circuit to the photosensitive film of the thickened multilayer board through selective irradiation with ultraviolet light; inner layer development: removing the photosensitive film in the unexposed area of ​​the thickened multilayer board, so that the copper surface of the unexposed area is exposed; inner layer etching: etching away the exposed copper surface of the thickened multilayer board; inner layer stripping: removing the exposed photosensitive film of the thickened multilayer board. In this step, by making inner layer circuits on the thickened inner layer board, large current can be circulated in the local thickened area; the AI ​​chip's demand for large current of thick copper in the local area is met, and the machinability and consistency of the PCB inner layer graphics are simultaneously ensured, so as to achieve stable operation of AI computing equipment and data reliability.

[0031] 220, layer pressing: according to the alignment holes of the thickened inner layer board, press the multiple thickened inner layer boards into a PCB multilayer board. In step 220, the layer pressing specifically includes: according to the alignment holes of the thickened inner layer board, aligning by rivets or positioning; and pressing the multiple thickened inner layer boards and the PP board to form a PCB multilayer board through high temperature and high pressure. Since the thickness of each core board and the thickness inside a single core board are different after the thickening treatment, when pressing multiple core boards, it is necessary to use the alignment holes for positioning and pressing.

[0032] Through steps 210-220, a preliminary multilayer board is formed, and then the multilayer board is subjected to mechanical drilling, electroplating, resin plugging, outer layer circuit, solder mask, surface treatment, molding, testing, FQC, packaging and other operations in sequence, and then the PCB board can be manufactured.

[0033] In some optional embodiments, after the inner layer is stripped, the following steps are further performed: AOI circuit inspection: scanning and obtaining the inner layer circuit of the thickened multilayer board and comparing it with the preset data graphics, recording suspected defects and screening out the defective thickened multilayer board. In this step, by checking the inner layer circuit of the thickened multilayer board, it can be determined whether the inner layer circuit in the thickened area and other areas is normal. Since the inner layer board has a thickened area, the stability of the inner layer circuit manufacturing can be detected by AOI circuit inspection.

[0034] In some optional embodiments, the layer lamination specifically includes: aligning by rivets or positioning according to the alignment holes of the thickened inner layer plate; and laminating a plurality of thickened inner layer plates and PP plates by high temperature and high pressure to form a PCB multilayer plate. In a specific example, a plurality of thickened inner layer plates and PP plates are arranged according to a set order, placed on a platen table of a platen press, and the plurality of thickened inner layer plates are positioned by rivets. After the positioning is completed, the temperature of the platen press is raised to 175°C and maintained for more than 70 minutes, and multilayer lamination is performed to ensure the formation of the PCB multilayer plate.

[0035] In some optional embodiments, before the inner layer circuit is made, the process further includes: cleaning the thickened inner layer board: cleaning the residual foreign matter and oil stains on the thickened inner layer board by water washing. Through this step, the surface cleanliness of the thickened inner layer board is ensured to avoid the presence of foreign matter and oil stains on the core board surface due to the process of steps 110-160, thereby affecting the subsequent inner layer circuit production.

[0036] In some optional embodiments, before the core board is punched, the process further includes: core board cutting: using a material divider to divide the raw material board into core boards according to the chip size. In this step, the core board is made by the inner layer circuit; wherein each core board has the same size and thickness; and the core board is partially thickened by subsequent steps 110-160.

[0037] Embodiment 2: According to another aspect of an embodiment of the present invention, a device for implementing a local high current flow through the inner layer of a PCB is provided, and the device is used to perform the above-mentioned method for implementing a local high current flow through the inner layer of a PCB to manufacture a printed circuit board. The device for implementing a local high current flow through the inner layer of a PCB of the present application manufactures a thickened inner layer board by performing the following steps: Punching a core board, obtaining the core board, and drilling holes aligned with the inner layer pattern around the core board by mechanical drilling; Core plate lamination, attaching a photosensitive film to the surface of the core plate; Core board exposure, selectively irradiating a preset area of ​​the core board with ultraviolet light to form a core board pattern on the surface of the core board; Opening holes in the photosensitive film, removing the photosensitive film in the unexposed area of ​​the core board, so that the unexposed area leaks out of the copper surface, and defining the unexposed area as a thickened area; Core plate electroplating, fixing the core plate peripheral side by a core plate fixture, and plating thick copper on the thickened area by electroplating after the core plate is fixed; The core board is stripped of the film, and the photosensitive film on the surface of the preset area of ​​the core board is removed to expose the preset area to form a thickened inner layer board.

[0038] Through the above steps, the present invention proposes a new design method in the inner layer production process. Before the inner layer is produced, the defect of the core board material that cannot achieve local thick copper is compensated by changing the process flow, so as to meet the AI ​​chip's demand for thick copper and large current in local areas, and simultaneously ensure the machinability and consistency of the PCB inner layer graphics, so as to achieve stable operation of AI computing equipment and data reliability, and reduce the thickness and cost of PCB products.

[0039] Embodiment 3: According to another aspect of the embodiment of the present invention, a printed circuit board is provided, and the printed circuit board is manufactured by the above-mentioned device for realizing local high current flow through the inner layer of the PCB and the above-mentioned method for realizing local high current flow through the inner layer of the PCB. The present invention performs core board punching on the core board in sequence to obtain the core board, and drills holes aligned with the inner layer pattern around the core board by mechanical drilling; core board lamination, attaching a photosensitive film to the surface of the core board; core board exposure, selectively irradiating a preset area of ​​the core board by ultraviolet light, forming a core board pattern on the surface of the core board; photosensitive film opening, removing the photosensitive film in the unexposed area of ​​the core board, allowing the copper surface of the unexposed area to leak out, and defining the unexposed area as a thickened area; core board electroplating, fixing the peripheral side of the core board by a core board clamp, and plating the thickened area with thick copper by electroplating after the core board is fixed; core board film removal, removing the photosensitive film on the surface of the preset area of ​​the core board, exposing the preset area, and forming a thickened inner layer board. The present invention proposes a new design method in the inner layer production process. Before the inner layer is produced, the defect of the core board material that cannot achieve local thick copper is compensated by changing the process flow, so as to meet the AI ​​chip's demand for thick copper and large current in local areas, and simultaneously ensure the machinability and consistency of the PCB inner layer graphics, so as to achieve stable operation of AI computing equipment and data reliability, and reduce the thickness and cost of PCB products.

[0040] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0041] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0042] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present invention may be implemented with the aid of hardware comprising several different elements and with the aid of appropriately programmed computers. In a unit claim that lists several systems, several of these systems may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A method for achieving local high current flow in the inner layer of a PCB, characterized in that: The method comprises: Punching a core board, obtaining the core board, and drilling holes aligned with the inner layer pattern around the core board by mechanical drilling; Core plate lamination, attaching a photosensitive film to the surface of the core plate; Core board exposure, selectively irradiating a preset area of ​​the core board with ultraviolet light to form a core board pattern on the surface of the core board; Opening holes in the photosensitive film, removing the photosensitive film in the unexposed area of ​​the core board, so that the unexposed area leaks out of the copper surface, and defining the unexposed area as a thickened area; Core plate electroplating, fixing the core plate peripheral side by a core plate fixture, and plating thick copper on the thickened area by electroplating after the core plate is fixed; The core board is stripped of the film, and the photosensitive film on the surface of the preset area of ​​the core board is removed to expose the preset area to form a thickened inner layer board.

2. A method for achieving local high current flow in the inner layer of a PCB according to claim 1, characterized in that: The core plate clamp comprises two clamping jaws arranged opposite to each other or four clamping jaws arranged along the four sides of the core plate. The clamping jaws are provided with clamping grooves matching the thickness of the core plate. The core plate clamp is used to clamp the two sides or four sides of the core plate to fix the core plate.

3. A method for achieving local high current flow in the inner layer of a PCB according to claim 1, characterized in that: After the core plate film removal step, the method further comprises: Inner layer circuit production: producing inner layer circuits on the thickened inner layer board; Layer pressing: according to the alignment holes of the thickened inner layer boards, a plurality of the thickened inner layer boards are pressed into a PCB multilayer board.

4. A method for achieving local high current flow in the inner layer of a PCB according to claim 3, characterized in that: The inner layer circuit production specifically includes: Inner lamination film: a photosensitive film is attached to the surface of the thickened multilayer board; Inner layer exposure: transferring the inner layer circuit to the photosensitive film of the thickened multilayer board through selective ultraviolet light irradiation; Inner layer development: removing the photosensitive film in the unexposed area of ​​the thickened multilayer board, so that the copper surface of the unexposed area is exposed; Inner layer etching: etching away the exposed copper surface of the thickened multilayer board; Inner layer stripping: removing the exposed photosensitive film of the thickened multilayer board.

5. A method for achieving local high current flow in the inner layer of a PCB according to claim 4, characterized in that: After the inner layer is stripped, the method further comprises: AOI circuit inspection: Scan and obtain the inner circuit of the thickened multilayer board and compare it with the preset data graphics, record suspected defects and screen out the defective thickened multilayer board.

6. The method for achieving local high current flow in the inner layer of a PCB according to claim 3, characterized in that: The layer lamination specifically includes: According to the alignment holes of the thickened inner layer board, the thickened inner layer boards are aligned by rivets or positioning; and the plurality of thickened inner layer boards and the PP board are pressed together by high temperature and high pressure to form a PCB multilayer board.

7. A method for achieving local high current flow in the inner layer of a PCB according to claim 3, characterized in that: Before the inner layer circuit is produced, the method further includes: Thickened inner layer board cleaning: clean the remaining foreign matter and oil stains on the thickened inner layer board by water washing.

8. The method for achieving local high current flow in the inner layer of a PCB according to claim 1, characterized in that: Before the core plate is punched, the method further comprises: Core board cutting: The raw material board is separated into core boards according to the chip size by a dividing machine.

9. A device for achieving local high current flow in the inner layer of a PCB, characterized in that: The device is used to implement the method for locally passing a large current through the inner layer of a PCB as described in any one of claims 1 to 8 to manufacture a printed circuit board.

10. A printed circuit board, characterized in that: The printed circuit board is manufactured by using the device for locally passing a large current through the inner layer of the PCB as described in claim 9 to execute the method for locally passing a large current through the inner layer of the PCB as described in any one of claims 1 to 8.

Images