PCB manufacturing method and device for improving copper thickness uniformity of resin plug hole and printed circuit board

Abstract

The invention relates to a PCB manufacturing method and device for improving copper thickness uniformity of a resin plug hole and a printed circuit board, and the method comprises the steps: sequentially carrying out the mechanical drilling, electroplating, protection film trepanning, protection film covering, resin plug hole protection film removing and board grinding on a PCB, and improving the uniformity of the resin plug hole of the PCB. The processing difficulty of a system-level product of a thick-copper high-density circuit designed in Via in pad in the AI era is solved, the problem of the thick-copper high-density circuit is solved through the technical scheme, the signal requirement is met, and meanwhile, the cost is reduced to a great extent.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of PCB manufacturing, and in particular to a PCB manufacturing method, device and printed circuit board for improving the uniformity of copper thickness of resin plug holes. Background Art

[0002] As the chip base, PCB is responsible for transmitting data signals and power distribution management. With the increase in AI computing power demand, the increase in chip size and pin number, high-end PCB boards have shown higher technical advantages driven by the demand for AI computing power. The traditional system-level high-layer through-hole PCB structure can no longer meet the computing power requirements. The technical requirements are becoming more complex, and special production processes are constantly iterating and upgrading. The combination of system-level PCB high-layer structure and consumer PCB high-density HDI technology has pushed PCB processing technology towards higher layers, denser wiring, smaller line widths, and more high-speed signal lines.

[0003] As circuit boards are becoming more and more high-density and interconnected, there is no more space to place the wires and pads that connect the through holes. Therefore, in this context, the production process of Via in pad came into being. The production process of Via in pad makes the production process of circuit boards three-dimensional, effectively saves horizontal space, and adapts to the development trend of high density and interconnection of modern circuit boards. VIP is to plug the plated via holes with screen printing fillers (insulating resin), and then dry, solidify, polish, and then electroplate. In this way, the entire surface of the board is covered with copper plating, and the via holes can no longer be seen. Via in pad achieves the purpose of combining the via holes and SM pads. This improves the electrical performance and reliability of electronic products, shortens the signal transmission wires, reduces the inductive and capacitive reactances of the transmission lines, and reduces internal and external electromagnetic interference.

[0004] In the process of resin plugging, in order to ensure the fullness of the plugged holes, the ink will overflow onto the board surface during plugging, and after baking and curing, raised lumps will be formed, and large-area lumps will appear in the BGA area with dense holes. During grinding, since the resin in the dense hole area of ​​BGA is a large-area agglomeration, it is necessary to completely remove the resin through multiple times or high current. This will cause excessive grinding of non-dense locations, resulting in poor uniformity of copper thickness between the BGA area and the non-BGA area, increasing the difficulty of subsequent circuit production, thereby affecting the integrity of the overall PCB signal. Summary of the invention

[0005] In view of the above problems, the embodiments of the present invention provide a PCB board gold finger wiring method, device and printed circuit board, which are used to solve the problem that low-lying areas are easily formed in the gold finger wiring design of LCD optoelectronic panels in the prior art, resulting in uneven board thickness, thereby causing low yield of existing LCD optoelectronic panels.

[0006] According to one aspect of an embodiment of the present invention, a method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plug holes is provided, the method comprising: Mechanical drilling, drilling signal holes on the PCB board, connecting the inner layer of the PCB board through the signal holes; One-time electroplating: a first copper plating layer is formed on the surface of the PCB and the signal hole by electroplating, and the inner layer line of the PCB is connected to the copper plating layer; The protective film is opened, and a first opening corresponding to the signal hole is made on the protective film according to the position of the signal hole; Protective film lamination, covering the surface of the PCB board with the protective film through a positioning device, wherein the first opening is coaxially arranged with the signal hole; Resin plugging hole, filling the signal hole with epoxy resin; Remove the protective film on the PCB to expose the surface of the PCB; Grinding: smoothing the surface of the PCB and removing excess epoxy resin from the surface of the PCB; Cover hole electroplating: copper is plated on the PCB board to form a second copper cladding layer to cover the epoxy resin in the signal hole; The outer layer circuit is processed by exposing and etching the second copper clad layer to form the outer circuit of the PCB board.

[0007] In some optional embodiments, in the step of opening a hole in the protective film, the radius of the first opening is 3 mil larger than the radius of the signal hole.

[0008] In some optional embodiments, in the resin plugging hole, epoxy resin is used to fill the signal hole, and the epoxy resin overflows the outer surface of the protective film.

[0009] In some optional embodiments, in the grinding step, the surface of the PCB board is smoothed by a brush wheel.

[0010] In some optional embodiments, after the mechanical drilling and before the electroplating, the process further includes: High-pressure water washing is used to remove debris from the signal hole.

[0011] In some optional embodiments, the outer layer circuit specifically includes: Pressed dry film treatment: covering the surface of the second copper cladding layer with a photosensitive film; Exposure treatment: exposing the photosensitive film to UV light; Development treatment: dissolve the unpolymerized photosensitive film during the exposure process to expose the copper surface; Etching process: The copper layer exposed on the copper surface is etched away to form the outer layer circuit.

[0012] In some optional embodiments, before the mechanical drilling step, the method further includes: Cutting: Cut the substrate by a board splitter to form a single-layer substrate; Inner layer circuit: making inner layer circuit on the single-layer substrate; Lamination: Lamination of multiple single-layer substrates with completed inner-layer circuits to form a PCB multi-layer board.

[0013] In some optional embodiments, after the outer layer circuit step, it also includes: also includes in sequence: solder mask, surface treatment, molding, testing, FQC, packaging.

[0014] According to another aspect of an embodiment of the present invention, a circuit board manufacturing device for improving the uniformity of copper thickness of resin plugged holes is provided, and the device is used to execute the above-mentioned circuit board manufacturing method for improving the uniformity of copper thickness of resin plugged holes 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 circuit board manufacturing method for improving the uniformity of copper thickness of resin plugging holes by the above-mentioned circuit board manufacturing device for improving the uniformity of copper thickness of resin plugging holes.

[0016] The PCB manufacturing method, device and printed circuit board for improving the uniformity of copper thickness of resin plugging holes of the present invention have the beneficial effects that: the present invention improves the uniformity of resin plugging holes of PCB board by sequentially performing mechanical drilling, electroplating, protective film opening, protective film coating, resin plugging, removing protective film and grinding on PCB board, thereby solving the processing problem of system-level products with thick copper and high-density circuits designed by Via in pad in the AI ​​era. The technical solution of the present invention not only solves the problem of thick copper running high-density circuits, but also meets the signal requirements, and at the same time reduces the cost to a great extent.

[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 in accordance with 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 methods of the present invention are 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 flow chart of a method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to Example 1 of the present invention is shown; Figure 2 A schematic diagram of mechanical drilling according to Example 1 provided by the present invention is shown; Figure 3 A schematic diagram of a primary electroplating process according to Example 1 provided by the present invention is shown; Figure 4 A schematic diagram of the protective film coating according to Example 1 provided by the present invention is shown; Figure 5 A schematic diagram of a resin plug hole according to Example 1 provided by the present invention is shown; Figure 6 A schematic diagram of removing the protective film of Example 1 provided by the present invention is shown; Figure 7 A schematic diagram of a grinding plate according to Example 1 provided by the present invention is shown; Figure 8 A schematic diagram of cover hole electroplating according to Example 1 provided by the present invention is shown; Fig. 9 A schematic diagram of an outer layer circuit of Example 1 provided by the present invention is shown; Among them, 1. PCB board; 2. signal hole; 3. first copper plating layer; 4. protective film; 5. first via; 6. epoxy resin; 7. second copper plating layer; 8. outer layer circuit. 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] Embodiment 1, See also Figure 1-9 According to one aspect of an embodiment of the present invention, a method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plug holes is provided, the method comprising: 110, mechanical drilling, drilling a signal hole on the PCB board, connecting the inner layer of the PCB board through the signal hole; in step 110, refer to Figure 2 , a channel is formed at the position where the PCB board 1 needs to be connected by mechanical drilling, forming a signal hole 2, and exposing the copper foil of the layer that needs to be connected.

[0021] 120, a first electroplating, by electroplating, a first copper plating layer is formed on the surface of the PCB board and the signal hole, and the inner layer line of the PCB board is connected to the copper plating layer; in step 120, see Figure 3 , through electroplating, the mechanical drill is used to form a first copper plating layer 3 on the conductive channel required on the PCB, and the inner copper foil exposed to the outside is connected to form a complete conductive network.

[0022] 130, making a hole in the protective film. According to the position of the signal hole, a first hole corresponding to the signal hole is made on the protective film. In step 130, according to the position diagram of the plug hole, a corresponding first hole 5 is drilled on the protective film 4 by mechanical drilling. The size of the hole is 3 mil larger than the hole on the PCB.

[0023] 140, protective film coating, the protective film is covered on the surface of the PCB board through a positioning device, wherein the first opening is coaxially arranged with the signal hole; in step 140, see Figure 4 , use the positioning holes to align the protective film with the PCB so that the openings can be completely aligned, facilitating the subsequent resin plugging operation.

[0024] 150, resin plugging hole, using epoxy resin to fill the signal hole; in step 150, see Figure 5 , mainly filling the vias with epoxy resin 6 to lay the foundation for subsequent electroplating caps to obtain more stable quality and achieve wiring density.

[0025] 160, remove the protective film, remove the protective film on the PCB board to expose the surface of the PCB board; in step 160, refer to Figure 6 , remove the protective film 4 of the resin plug hole, take away the excess resin agglomerates on the surface, leaving only a slight protrusion at the hole position, reducing the complexity and difficulty of the edge grinding process, and minimizing the difference in copper thickness uniformity caused by the grinding plate, so as to achieve high-density circuit design.

[0026] 170, grinding the board, smoothing the surface of the PCB board and removing excess epoxy resin from the surface of the PCB board; in step 170, see Figure 7 The excess resin at the hole mouth is removed by brushing and grinding to obtain a smooth surface, which is convenient for subsequent electroplating operations, as well as graphic processing and circuit wiring.

[0027] 180, cover hole electroplating, by electroplating, the PCB board is copper plated to form a second copper clad layer 7 to cover the epoxy resin in the signal hole; in step 180, see Figure 8 By electroplating copper, the holes at the original resin plug positions are covered with copper to form a second copper cladding layer 7; the holes are not visible on the surface, achieving wiring density.

[0028] 190, outer layer circuit, the second copper clad layer is processed by exposure and etching to form the outer circuit of the PCB board. In step 190, see Fig. 9The outer layer circuit 8 specifically includes: dry film pressing treatment: covering the surface of the second copper cladding layer with a photosensitive film; exposure treatment: exposing the photosensitive film by UV light; development treatment: dissolving the unpolymerized photosensitive film in the exposure treatment to expose the copper surface; etching treatment: etching away the copper layer exposed on the copper surface to form an outer layer circuit.

[0029] The present invention improves the uniformity of resin plugging holes on a PCB board by sequentially performing mechanical drilling, electroplating, opening holes on a protective film, covering a protective film, plugging holes with resin, removing the protective film, and grinding the board. Specifically, the protective film is opened, and a first opening corresponding to the signal hole is made on the protective film according to the position of the signal hole; the protective film is coated, and the protective film is covered on the surface of the PCB board by a positioning device, wherein the first opening is coaxially arranged with the signal hole; the resin plugging hole is filled with epoxy resin in the signal hole; the protective film is removed, and the protective film on the PCB board is removed to expose the surface of the PCB board; the board is ground, and the surface of the PCB board is flattened and excess epoxy resin on the surface of the PCB board is removed; the cover hole is electroplated, and the PCB board is copper-plated by electroplating to form a second copper-clad layer to cover the epoxy resin in the signal hole.

[0030] The processing problem of system-level products with thick copper and high-density circuits designed with via in pad in the AI ​​era is solved. The technical solution of the present invention not only solves the problem of thick copper and high-density circuits, but also meets the signal requirements, while greatly reducing the cost.

[0031] In some optional embodiments, in the step of opening a hole in the protective film, the radius of the first opening is 3 mil larger than the radius of the signal hole. In this embodiment, according to the position diagram of the plug hole, the corresponding hole is drilled on the protective film by mechanical drilling, and the size of the first opening is 3 mil larger than the hole on the PCB. By enlarging the size of the first opening by 3 mil, the signal hole can be fully covered to avoid the blind area of ​​the signal hole from being plugged in place.

[0032] In some optional embodiments, in the resin plugging hole, epoxy resin is used to fill the signal hole, and the epoxy resin overflows the outer surface of the protective film, so that the signal hole can be completely covered to avoid the signal hole blind area not being plugged in place.

[0033] In some optional embodiments, in the grinding step, the surface of the PCB is smoothed by a brush wheel. In addition, the brush wheel can be replaced by a non-woven fabric or a ceramic brush to remove the resin agglomerates remaining on the PCB surface by grinding.

[0034] In some optional embodiments, after the mechanical drilling and before the electroplating, it further includes: high-pressure water washing, which removes debris from the signal hole. In this embodiment, the purpose of adding high-pressure water washing is mainly to remove the poor chip removal of the depth-controlled hole by the depth-controlled drilling equipment after the depth-controlled drilling, and to use the impact of high-pressure water to remove the debris that has not been removed from the depth-controlled hole.

[0035] In some optional embodiments, the outer layer circuit specifically includes: dry film treatment: covering the surface of the second copper cladding layer with a photosensitive film; exposure treatment: exposing the photosensitive film by UV light; development treatment: dissolving the unpolymerized photosensitive film in the exposure treatment to expose the copper surface; etching treatment: etching and removing the copper layer exposed on the copper surface to form an outer layer circuit.

[0036] In some optional embodiments, before the mechanical drilling step, the PCB board is formed in sequence by cutting, inner layer circuit, and pressing, specifically including: cutting: cutting the substrate by a board splitter to form a single-layer substrate; cutting is to use an automatic slitting machine to cut the substrate material into a core board. Inner layer circuit: making inner layer circuits on the single-layer substrate; sticking a dry film on the surface of the single-layer substrate to prepare for subsequent image transfer; using an exposure device to expose the coated substrate with ultraviolet light, so as to transfer the image of the substrate to the dry film; developing, etching, and removing the exposed substrate to complete the production of the inner layer board. Pressing: pressing multiple single-layer substrates with completed inner layer circuits to form a PCB board; pressing multiple single-layer substrates once or multiple times to form a PCB board.

[0037] In some optional embodiments, after the outer layer circuit step, it also includes: solder mask, surface treatment, molding, testing, FQC, and packaging. In this embodiment, solder mask: the surface of the PCB multilayer board is treated with solder mask to prevent oxidation and other phenomena. Surface treatment: the side of the bare copper plate to be welded is coated to form an organic film to prevent rust and oxidation, specifically including pickling, ultrasonic water washing and other processes to remove the board oxide and increase the roughness of the copper surface; the PCB multilayer board does not need to be welded. Cover the solder mask ink to play a protective and insulating role; dry the solvent in the solder mask ink and harden the ink for exposure; cure the solder mask ink by UV light irradiation, and form a high molecular polymer through photosensitive polymerization; remove the sodium carbonate solution in the unpolymerized ink; and completely harden the ink. Molding: The board shape required by the customer is produced to facilitate the customer to carry out patch and assembly. Testing: Test the board circuit to avoid the outflow of defective boards with short circuits. FQC: Final inspection, sampling and full inspection after completing all processes. Packaging: vacuum pack the finished PCB multilayer boards, package and ship them to complete the delivery.

[0038] Embodiment 2: According to another aspect of the present invention, a circuit board manufacturing device for improving the uniformity of copper thickness of resin plugging holes is provided, and the device is used to perform the above-mentioned circuit board manufacturing method for improving the uniformity of copper thickness of resin plugging holes to manufacture printed circuit boards. The device can perform pressing → mechanical drilling → high-pressure water washing → electroplating → opening holes in protective film → covering protective film → resin plugging holes → removing protective film → grinding plate → electroplating capping → outer layer circuit → solder mask. Figure 2-9 The specific process of manufacturing a circuit board for improving the uniformity of copper thickness of resin plug holes in this application is as follows: Mechanical drilling: A channel is formed at the location where the PCB needs to be connected through mechanical drilling, exposing the copper foil of the conductive layer.

[0039] High-pressure water washing: The purpose of adding high-pressure water washing is mainly to remove the poor chip removal of the depth-controlled hole by the depth-controlled drilling equipment after depth-controlled drilling, and to use the impact of high-pressure water to remove the debris that has not been cleaned out in the depth-controlled hole.

[0040] Primary electroplating: Through electroplating, the inner copper foil exposed to the outside is connected by mechanical drilling on the conductive channel of the PCB to form a complete conductive network. Protective film lamination: Use positioning holes to align the protective film with the PCB so that the openings can be completely aligned, facilitating subsequent resin plugging operations.

[0041] Resin plugging: mainly filling the vias with epoxy resin to lay the foundation for subsequent electroplating caps to obtain more stable quality and achieve wiring density.

[0042] Removing protective film: Remove the protective film of the resin plug hole and take away the excess resin agglomerates on the surface, leaving only a slight protrusion at the hole position, reducing the complexity and difficulty of the edge grinding process, and minimizing the difference in copper thickness uniformity caused by grinding the plate, so as to achieve high-density circuit design.

[0043] Grinding plate: The excess resin at the hole mouth is removed by brush grinding to obtain a smooth surface, which is convenient for subsequent electroplating operations, as well as graphic processing and circuit wiring.

[0044] Cover hole plating: Through the method of copper electroplating, the holes at the original resin plug positions are covered with copper so that the holes are not visible on the surface, thus achieving wiring density.

[0045] Outer layer circuit: through exposure and etching, the final design pattern is completed.

[0046] The above solution solves the processing problem of system-level products with thick copper and high-density lines designed with via in pad in the AI ​​era. New ideas are adopted in the process flow, which not only solves the problem of thick copper and high-density lines, but also meets the signal requirements, while greatly reducing costs.

[0047] Embodiment 3: According to another aspect of an embodiment of the present invention, a printed circuit board is provided, and the printed circuit board is manufactured by executing the circuit board manufacturing method for improving the uniformity of copper thickness of resin plugging holes as described above through the circuit board manufacturing device for improving the uniformity of copper thickness of resin plugging holes as described above. The present invention improves the uniformity of resin plugging holes of PCB board by mechanical drilling, electroplating, opening holes in protective film, covering protective film, removing protective film from resin plugging holes, and grinding the board in sequence, thereby solving the processing problem of system-level products with thick copper and high-density circuits designed by Via inpad in the AI ​​era. The technical solution of the present invention not only solves the problem of thick copper running high-density circuits and meets signal requirements, but also reduces costs to a great extent.

[0048] 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.

[0049] 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.

[0050] 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 manufacturing a circuit board for improving the uniformity of copper thickness of resin plug holes, characterized in that: The method comprises: Mechanical drilling, drilling signal holes on the PCB board, connecting the inner layer of the PCB board through the signal holes; One-time electroplating: a first copper plating layer is formed on the surface of the PCB and the signal hole by electroplating, and the inner layer line of the PCB is connected to the copper plating layer; The protective film is opened, and a first opening corresponding to the signal hole is made on the protective film according to the position of the signal hole; Protective film lamination, covering the surface of the PCB board with the protective film through a positioning device, wherein the first opening is coaxially arranged with the signal hole; Resin plugging hole, filling the signal hole with epoxy resin; Remove the protective film on the PCB to expose the surface of the PCB; Grinding: smoothing the surface of the PCB and removing excess epoxy resin from the surface of the PCB; Cover hole electroplating: copper is plated on the PCB board to form a second copper cladding layer to cover the epoxy resin in the signal hole; The outer layer circuit is processed by exposing and etching the second copper clad layer to form the outer circuit of the PCB board.

2. The method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to claim 1, characterized in that: In the step of opening a hole in the protective film, the radius of the first opening is 3 mil larger than the radius of the signal hole.

3. The method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to claim 1, characterized in that: In the resin plugging hole, epoxy resin is used to fill the signal hole, and the epoxy resin overflows the outer surface of the protective film.

4. The method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to claim 1, characterized in that: In the grinding step, the surface of the PCB is smoothed by a brush wheel.

5. The method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to claim 1, characterized in that: After the mechanical drilling and before the primary electroplating, the method further includes: High-pressure water washing is used to remove debris from the signal hole.

6. The method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to claim 1, characterized in that: The outer layer circuit specifically includes: Pressed dry film treatment: covering the surface of the second copper cladding layer with a photosensitive film; Exposure treatment: exposing the photosensitive film to UV light; Development treatment: dissolve the unpolymerized photosensitive film during the exposure process to expose the copper surface; Etching process: The copper layer exposed on the copper surface is etched away to form the outer layer circuit.

7. The method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to claim 1, characterized in that: Before the mechanical drilling step, the method further comprises: Cutting: Cut the substrate by a board splitter to form a single-layer substrate; Inner layer circuit: making inner layer circuit on the single-layer substrate; Lamination: Lamination of multiple single-layer substrates with completed inner-layer circuits to form a PCB multi-layer board.

8. The method for manufacturing a circuit board for improving the uniformity of copper thickness of resin plugged vias according to claim 1, characterized in that: After the outer layer circuit step, it also includes: solder mask, surface treatment, molding, testing, FQC, and packaging.

9. A circuit board manufacturing device for improving the uniformity of copper thickness of resin plug holes, characterized in that: The device is used to execute the circuit board manufacturing method for improving the uniformity of copper thickness of resin plugged holes 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 circuit board manufacturing device for improving the uniformity of copper thickness of resin plugging holes as described in claim 9 to execute the circuit board manufacturing method for improving the uniformity of copper thickness of resin plugging holes as described in any one of claims 1 to 8.

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