A power supply circuit board with semi-hole sidewall copper and a manufacturing method thereof

Abstract

The application discloses a power circuit board with half-hole side wall copper and a manufacturing method thereof, and relates to the technical field of power circuit board manufacturing. The method comprises the following steps: obtaining a multi-layer copper-clad plate containing an inner layer circuit pattern; milling a side wall groove around a finished unit of the multi-layer copper-clad plate; using a mechanical drill to process a through hole and a tool hole on the multi-layer copper-clad plate, and processing a plurality of half-hole arcs on the groove wall of the side wall groove; forming a metalized copper layer on the surface of the side wall groove and the half-hole arcs, and obtaining the power circuit board with side wall copper through subsequent processing. The method processes the half-hole arcs at the side wall groove, changes the side wall copper from a flat structure to a concave-convex structure, increases the effective contact area of the side wall copper shielding structure, and significantly improves the inhibition ability of the side wall copper to high-frequency electromagnetic interference through multiple reflection and scattering of electromagnetic waves on the concave-convex surface.

Description

Technical Field

[0001] This invention relates to the field of power circuit board manufacturing technology, specifically to a power circuit board with copper sidewalls through a half-hole and its manufacturing method. Background Technology

[0002] With the continuous evolution of information technology, the operating frequency and signal transmission rate of electronic devices are constantly increasing, and the requirements for signal integrity of printed circuit boards (PCBs) are becoming increasingly stringent. Against this backdrop, electromagnetic interference (EMI) caused by electromagnetic waves has become one of the key factors affecting the functional stability and electromagnetic compatibility performance of electronic products.

[0003] Studies have shown that rapid voltage changes (dv / dt) and current jumps (di / dt) on power circuit boards are the main initial sources of EMI emission, making circuit boards the core emission points of electromagnetic radiation within PCBs and electronic devices. Electromagnetic waves not only radiate and diffuse freely in three-dimensional space, but also conduct outwards along metallic conductors (including power lines, signal lines, and grounding structures), forming a combined radiation and conduction interference path.

[0004] As the "motherboard" of electronic products, the design of the PCB's edges plays a crucial role in suppressing electromagnetic interference (EMI) in the entire device. Current technology commonly employs a continuous, enclosed copper-clad structure (hereinafter referred to as sidewall copper) along the board edges to form a low-impedance shielding layer, reflecting and absorbing electromagnetic waves to weaken their external radiation. However, traditional sidewall copper is a planar, straight-edge structure. While continuous copper plating can form a basic shielding barrier, its effective contact area is limited only by the slot length and copper layer thickness. The physical interface for electromagnetic wave absorption and reflection is relatively limited, making it difficult to achieve optimal shielding performance, especially at high frequencies where its suppression capability is significantly insufficient. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the existing sidewall copper shielding structure has a limited contact area, which cannot fully absorb and reflect electromagnetic waves and cannot meet the increasingly stringent electromagnetic interference suppression requirements of high-frequency and high-speed electronic products. The purpose is to provide a power circuit board with a half-hole sidewall copper and its manufacturing method, thereby solving the above problems.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a method for manufacturing a power circuit board with copper sidewalls in a half-hole, comprising:

[0008] Provides multilayer copper-clad boards containing inner layer circuit patterns;

[0009] Side wall grooves are milled around the finished unit of the multilayer copper-clad laminate;

[0010] Using a mechanical drilling machine, through holes and tool holes are machined on the multilayer copper-clad laminate, and multiple semi-circular arcs are machined on the groove wall of the sidewall groove.

[0011] A metallized copper layer is formed on the surface of the sidewall groove and the semi-circular arc of the hole, and a power circuit board is obtained through subsequent processing.

[0012] Optionally, the provision of the multilayer copper-clad laminate containing inner layer circuit patterns includes:

[0013] Provides an inner core board containing inner layer circuit patterns;

[0014] Grooves are formed on the inner core plate;

[0015] Copper busbars are fed into the tank, and the inner core board and the copper busbars are subjected to browning treatment to obtain the browned inner core board.

[0016] The browned inner core board, prepreg, and copper foil are laminated together to form a multilayer copper-clad laminate.

[0017] Optionally, the provision of the inner layer core board including the inner layer circuit pattern includes:

[0018] Large sheets of wood are cut into multiple production boards, which are then cleaned by high-pressure water washing and baked.

[0019] The surface of the production board is roughened, and then photosensitive ink is applied to the roughened surface. After exposure and development according to the design requirements, the copper plating outside the alignment pattern around the board edge is removed by etching to obtain the inner core board containing the inner layer circuit pattern.

[0020] Optionally, after providing an inner layer core board containing inner layer circuit patterns, the method further includes:

[0021] Use an optical positioning punching machine to punch rivet holes in the inner core board;

[0022] The process involves laminating the browned inner core board, prepreg, and copper foil to form a multilayer copper-clad laminate, including...

[0023] The core board, prepreg, and copper foil are stacked in sequence, and rivets are inserted into the rivet holes for riveting and fixing. Then, with the assistance of a mirror steel plate, the material is fed into a press and formed into a multi-layer copper-clad laminate by heating and pressing.

[0024] Optionally, after forming a multilayer copper-clad laminate by heating and pressurizing, the method further includes:

[0025] After the multilayer copper-clad laminate is removed from the press and cooled to room temperature, the edges of the multilayer copper-clad laminate are trimmed to obtain a multilayer copper-clad laminate of a preset size.

[0026] Optionally, forming a metallized copper layer on the surface of the sidewall groove and the semi-circular arc includes:

[0027] The surface of the multilayer copper-clad laminate to be metallized is deburred and desmeared; the surface to be metallized includes the hole wall of the through hole, the hole wall of the tool hole, the groove surface of the side wall groove, and the inner wall of the semi-hole arc.

[0028] A bottom copper layer is deposited on the surface to be metallized by chemical deposition.

[0029] The copper layer is thickened on the underlying copper layer by electroplating.

[0030] Optionally, the fabrication of the power circuit board with copper sidewalls obtained through subsequent processing includes:

[0031] The outer layer circuit pattern is fabricated on the multilayer copper-clad laminate;

[0032] The outer layer circuit pattern of the multilayer copper-clad laminate is inspected using an automated optical inspection machine.

[0033] The surface of the qualified multilayer copper-clad laminate is roughened. After roughening, solder resist ink is applied to the surface. After exposure and development according to the design requirements, the unexposed copper surface area to be soldered is exposed.

[0034] The multilayer copper-clad laminate is cut into at least one power circuit board using a forming milling cutter.

[0035] Optionally, the step of fabricating the outer layer circuit pattern of the multilayer copper-clad laminate includes:

[0036] A dry film is applied to the surface of the multilayer copper-clad laminate using a pattern transfer method, revealing the outer layer circuit pattern.

[0037] The copper layer of the outer circuit pattern is further thickened, and an anti-corrosion tin layer is electroplated.

[0038] After removing the dry film using sodium hydroxide, the exposed copper surface is removed by etching solution and the tin layer is removed to expose the outer circuit pattern.

[0039] Optionally, after cutting the multilayer copper-clad laminate into at least one power circuit board using a forming milling cutter, the method further includes:

[0040] Electrical tests are performed on at least one power supply circuit board, and power supply circuit boards that pass the electrical tests are selected.

[0041] The power circuit boards that pass the electrical test are visually inspected, and those that pass the visual test are selected.

[0042] The power circuit boards that meet the appearance requirements are vacuum-packed.

[0043] In a second aspect, the present invention provides a power circuit board with copper sidewalls at half-holes, characterized in that it is manufactured by the power circuit board manufacturing method of copper sidewalls at half-holes as described in any one of the first aspects, wherein the power circuit board has a sidewall groove on its edge, and the groove wall of the sidewall groove has an undulating structure formed by multiple semi-hole arcs.

[0044] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0045] This application provides a method for manufacturing a power circuit board with copper sidewalls with semi-holes. After milling sidewall grooves around the finished unit of a multilayer copper-clad laminate, multiple semi-hole arcs are machined in the sidewall grooves, transforming the originally planar sidewall groove walls into a non-planar structure with undulating surfaces. A metallized copper layer is simultaneously formed on the sidewall groove surface and the inner wall of the semi-hole arcs. This expands the effective shielding area of ​​the copper sidewalls of the power circuit board from a planar area of ​​groove length × copper thickness to the sum of the planar area and the area of ​​the inner wall of all the semi-hole arcs. Through the non-planar structure with undulating surfaces, electromagnetic waves undergo multiple reflections and scattering on the surface of the copper sidewalls, increasing the transmission loss path of electromagnetic wave energy at the board boundary. Thus, with minimal process modifications, the ability of the copper sidewalls to suppress high-frequency electromagnetic interference is significantly improved, effectively reducing the functional impact on surrounding electrical components. This meets the increasingly stringent electromagnetic compatibility design requirements of high-frequency and high-speed electronic products and is suitable for high-current power circuit boards with EMI shielding requirements. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0047] Figure 1 A schematic flowchart illustrating a method for fabricating a power circuit board with copper sidewalls through a half-hole provided in an embodiment of this application.

[0048] Figure 2 A schematic diagram of the process for obtaining a multilayer copper-clad board containing inner layer circuit patterns, provided for an embodiment of this application;

[0049] Figure 3 A schematic diagram of the process for obtaining a power circuit board through subsequent processing provided in an embodiment of this application;

[0050] Figure 4 This is another schematic flowchart illustrating the method for fabricating a power circuit board with copper sidewalls through a half-hole, as provided in an embodiment of this application. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0052] Please refer to Figure 1 This is a schematic flowchart illustrating a method for fabricating a power circuit board with copper sidewalls through a half-hole, as provided in an embodiment of this application. The following describes... Figure 1 The method for fabricating a power circuit board with copper sidewalls in the half-hole shown is introduced.

[0053] S1. Provides a multilayer copper-clad board containing inner layer circuit patterns;

[0054] S2. Mill sidewall grooves around the finished unit of the multilayer copper clad laminate;

[0055] S3. Use a mechanical drilling machine to process through holes and tool holes on the multilayer copper-clad board, and process multiple half-hole arcs on the side wall groove.

[0056] S4. A metallized copper layer is formed on the surface of the side wall groove and the semi-circular arc, and the power circuit board is obtained through subsequent processing.

[0057] In one possible embodiment, such as Figure 2 As shown, the steps of S1 include:

[0058] S1.1 Provide an inner core board containing inner layer circuit patterns;

[0059] S1.2 Use an optical positioning punching machine to punch rivet holes in the inner core board;

[0060] S1.3. Slots are formed on the inner core board;

[0061] S1.4. Place the copper busbar into the tank and perform browning treatment on the inner core board and the copper busbar to obtain the browned inner core board.

[0062] S1.5 Stack the core board, prepreg and copper foil in sequence, insert rivets into the rivet holes for riveting and fixing, and then feed them into the press with the assistance of mirror steel plate to form a multi-layer copper-clad board by heating and pressurizing.

[0063] S1.6 Remove the multilayer copper-clad laminate from the press and allow it to cool to room temperature. Then, trim the edges of the multilayer copper-clad laminate to obtain a multilayer copper-clad laminate of the preset size.

[0064] In one possible embodiment, step S1.1 includes:

[0065] S1.11 Cut the large sheet of board into multiple production boards, clean them with high-pressure water washing and bake the surface of the production boards;

[0066] S1.12. Roughen the surface of the production board, coat the roughened board surface with photosensitive ink, expose and develop according to the design requirements, and then remove the copper plating outside the alignment pattern around the board edge by etching to obtain the inner core board containing the inner layer circuit pattern.

[0067] Specifically, S1.11 is the cutting and cutting step: First, use an automatic cutting machine to cut the large sheet of board into 4-6 (or more) small production boards. Then, clean the surface of each production board with high-pressure water washing and dry it to remove dust and copper shavings caused by the cutting process. Finally, bake the dried production board at high temperature (e.g., at 150 degrees Celsius for 300 minutes) to remove the internal moisture of the board, release the internal stress of cutting and stabilize the board size, thereby preventing defects such as delamination, bubbling and board warping in the subsequent pressing process.

[0068] S1.12 describes the inner layer circuit fabrication steps: The production board surface is roughened using NPS micro-etching solution combined with volcanic ash, creating a plow-like micro-rough surface to increase surface roughness and facilitate better ink adhesion. A layer of ink is applied to the roughened surface using electrostatic spraying or screen printing. After exposing the ink to the inner layer circuit pattern using an automatic exposure machine, unexposed ink is removed using sodium carbonate spray development, exposing the unexposed copper areas. The exposed copper areas are then completely etched away using an etching solution. Finally, the remaining photosensitive ink on the circuit pattern surface is removed, revealing the desired inner layer circuit pattern while preserving the alignment pattern around the board edges, thus obtaining the inner layer core board.

[0069] S1.2 is the inner layer drilling step: Using an optical positioning punching machine (OPE), the alignment target on the inner layer core board is identified. With the center of the target as the reference, rivet holes are punched around the edge of the inner layer core board. The punched rivet holes are used to insert rivets in the subsequent pressing process to fix each layer core board. Then, the inner layer circuit pattern of the inner layer core board is inspected. Boards with open circuits, short circuits, incomplete etching, and other pattern defects that cannot be repaired are judged as unqualified products and discarded.

[0070] S1.3 is the slotting step: a slot of a predetermined size is slotted out on the inner core board for embedding copper busbars. The dimensions of the slot are 0.1mm larger than the length, width and height of the copper busbars.

[0071] S1.4 is the browning step: copper busbars are placed into the tank to brown the inner core board and copper busbars, so that a roughened oxide layer is formed on the copper surface to enhance the bonding force between the copper busbars and the prepreg in the subsequent lamination process.

[0072] S1.5 is the lamination step: The core board, prepreg, and copper foil are stacked in sequence, and rivets are inserted into the rivet holes to fix them in place to prevent relative displacement between the layers during the lamination process; the riveted and fixed stack is placed between mirror steel plates and sent into the press. By heating and pressurizing, the prepreg is heated, melted, flowed, and fills the gaps between the layers, thus laminating the inner core board and copper foil into one piece. The lamination time is about 180 minutes, forming a multilayer copper-clad laminate.

[0073] S1.6 is the edge forming step: After the multilayer copper-clad laminate is pressed, it is taken out from the press and placed on a transport vehicle to cool naturally to room temperature. Then, the edges of the board are cut according to the design requirements to remove the excess material on the board edge and obtain the multilayer copper-clad laminate of the preset size.

[0074] S2 is the first milling step for copper plates: the multi-layer copper-clad laminate after pressing and molding is placed on the worktable of the forming milling machine (milling machine), and the milling cutter is controlled according to the preset program to mill along the design trajectory around the finished unit, and side wall grooves of predetermined width and depth are milled out around the four sides of the finished unit.

[0075] S3 is the mechanical drilling step: The multilayer copper-clad laminate is placed on the worktable of the mechanical drilling machine. Different sized drill bits are selected according to design requirements to drill through holes and tool holes on the multilayer copper-clad laminate. The through holes are used to achieve electrical connections between different conductive layers of the multilayer circuit board, while the tool holes are used for positioning, alignment, or clamping of the multilayer copper-clad laminate during processing.

[0076] Meanwhile, multiple drilling positions are arranged at equal or unequal intervals along the length of the sidewall groove. The drill bit is drilled vertically downward from the surface of the multilayer copper-clad laminate, so that the drilled hole intersects with the sidewall groove. Since the sidewall groove is a hollow structure, after the drill bit passes through the board surface, the hole wall on one side of the sidewall groove is missing due to being suspended, leaving only the other half of the hole wall connected to the sidewall groove wall, thus forming multiple half-hole arcs. The drilled half-hole arcs form an uneven non-planar structure on the sidewall groove wall to increase the coverage area of ​​the subsequent metallized copper layer.

[0077] In one possible embodiment, such as Figure 3 As shown, the steps in S4 include:

[0078] S4.1 Deburring and removing adhesive residue from the surface of the multilayer copper clad laminate to be metallized;

[0079] S4.2 Deposit an underlying copper layer on the surface to be metallized by chemical deposition;

[0080] S4.3. Thicken the copper layer on the bottom copper layer by electroplating.

[0081] S4.4. Apply a dry film to the surface of the multilayer copper-clad board using a graphic transfer method to reveal the outer layer circuit pattern.

[0082] S4.5. The copper layer of the outer circuit pattern is further thickened and an anti-corrosion tin layer is electroplated.

[0083] S4.6 After removing the dry film with sodium hydroxide, remove the exposed copper surface and remove the tin layer with etching solution to expose the outer circuit pattern;

[0084] S4.7 Inspect the outer layer circuit pattern of the multilayer copper-clad laminate using an automatic optical inspection machine;

[0085] S4.8. Roughen the surface of the qualified multilayer copper-clad laminate, apply solder resist ink to the roughened surface, expose and develop it according to the design requirements, and expose the unexposed copper surface area to be soldered.

[0086] S4.9 Use a forming milling cutter to cut the multilayer copper-clad laminate into at least one power circuit board.

[0087] Specifically, S4.1 is the deburring and descaling step: Drilling slag, burrs, and adhesive residue generated during the mechanical drilling and milling processes are first removed by grinding with a grinding machine to remove burrs from the hole openings and the surfaces to be metallized. Then, the adhesive residue on the surfaces to be metallized is removed using a chemical descaling solution (such as potassium permanganate solution). The surfaces to be metallized include the walls of through holes, tool holes, sidewall grooves, and the inner walls of the semi-circular arcs. After the above treatment, the hole walls, sidewall groove surfaces, and the inner walls of the semi-circular arcs are clean and have uniform roughness, forming a smooth surface to be metallized, ensuring good adhesion between the copper layer and the substrate during subsequent copper plating.

[0088] S4.2 is the copper plating step: The multilayer copper-clad laminate, after deburring and desmearing treatment, is immersed in the copper plating solution. A 5μm thick bottom copper layer is deposited on the hole walls of the through holes, the hole walls of the tool holes, the groove surface of the side wall grooves, and the inner wall of the semi-hole arc through chemical deposition, providing a conductive seed layer for subsequent electroplating thickening.

[0089] S4.3 is the board surface electroplating step: After copper plating, the multilayer copper-clad board is placed in the electroplating solution, and the copper layer is thickened on the board surface, the walls of each hole and the groove surface of the side wall and the inner wall of the semi-hole arc by electroplating, so that the copper layer thickness meets the specifications required by the customer's design.

[0090] S4.4 describes the steps for creating the outer layer circuit pattern: A dry film is attached to the surface of the multilayer copper-clad laminate. An automatic exposure machine is used to expose the dry film on the board surface according to the design requirements of the outer layer circuit pattern, causing the dry film in the designed circuit pattern area to undergo a polymerization reaction and solidify. Then, sodium carbonate developer is used to spray and develop the dry film in the unexposed areas, exposing the copper surface area to be electroplated and thickened, thus revealing the outer layer circuit pattern.

[0091] S4.5 is the pattern electroplating step: The multilayer copper-clad board with the outer circuit pattern is placed in the electroplating solution, the exposed copper layer of the circuit pattern is thickened, and a layer of corrosion-resistant tin layer (the thickness of the tin layer is 8 to 10 μm) is electroplated on the surface of the thickened copper layer.

[0092] S4.6 is the outer layer alkaline etching step: Sodium hydroxide solution is used to remove the remaining dry film on the board surface, so that the copper surface of the non-circuit area is fully exposed; the exposed copper surface of the non-circuit area is completely etched away by alkaline etching solution, and the circuit pattern area is preserved due to the protection of the tin resist layer; finally, tin stripping solution is used to remove the tin resist layer on the surface of the circuit pattern, revealing the outer layer circuit pattern.

[0093] S4.7 is the AOI inspection step: The outer layer circuit pattern of the multilayer copper-clad board with the outer layer circuit pattern completed is inspected by an automatic optical inspection machine (AOI) to identify whether there are pattern defects such as open circuit, short circuit, gap, pinhole, etc. Boards with pattern defects such as open circuit, short circuit, gap, pinhole, etc. that cannot be repaired are judged as unqualified products and discarded.

[0094] S4.8 is the solder resist step: NPS micro-etching solution combined with volcanic ash is used to roughen the surface of the multilayer copper-clad board after the outer layer circuit pattern is made, so that the board surface forms a plow-like micro-rough surface to increase the contact area and adhesion between the copper surface and the solder resist ink; then, a layer of solder resist ink is evenly coated on the board surface by electrostatic spraying or screen printing; the solder resist ink on the board surface is exposed by an automatic exposure machine according to the design requirements to cure the areas to be covered with solder resist ink; then, sodium carbonate spray development is used to remove the solder resist ink in the unexposed areas, exposing the unexposed copper surface areas to be soldered.

[0095] S4.9 is the peripheral forming step: The multilayer copper-clad laminate with solder mask treatment is placed on the worktable of the forming router. The forming router cutter is used to cut along the outline of each finished unit, dividing the multilayer copper-clad laminate into multiple independent power circuit boards. After cutting, the divided power circuit boards are sent to the cleaning machine, where the board surface and edges are cleaned and rinsed using high-pressure water washing or ultrasonic cleaning to remove dust, copper shavings, and burrs generated during the cutting process, ensuring that the board surface and edges are clean and avoiding dust residue affecting subsequent electrical testing and appearance inspection.

[0096] In one possible embodiment, please continue to refer to Figure 3 After executing S4.9, the method also includes:

[0097] S4.10. Perform electrical tests on at least one power supply circuit board and select the power supply circuit boards that pass the electrical tests.

[0098] S4.11. Conduct a visual inspection on the power circuit boards that have passed the electrical test, and select those that pass the visual test.

[0099] S4.12. Vacuum-pack power circuit boards that meet appearance standards.

[0100] Specifically, S4.10 is the electrical testing procedure: Place the power circuit board on the electrical testing fixture, and perform continuity and high voltage tests on the circuit board by contacting the test points on the board surface through the test fixture; The continuity test is used to detect whether there are open circuit or short circuit defects in the conductive network of the circuit board, and the high voltage test is used to detect whether the insulation performance of the circuit board under different voltage conditions meets the design requirements; After the test is completed, the power circuit boards that fail the electrical test are classified and processed according to the defect type, those that can be repaired are repaired, and those that cannot be repaired are scrapped.

[0101] S4.11 is the final inspection step: For power circuit boards that have passed electrical testing, a visual inspection and a board bending / warping inspection are performed. The visual inspection includes checking for scratches, dirt, oxidation, ink peeling, circuit damage, and other appearance defects on the board surface. The board bending / warping inspection includes placing the power circuit board on a flat platform and using a plug gauge or warping meter to measure the degree of warping on the board surface, ensuring that the warping meets the shipment quality requirements. After testing, power circuit boards that fail the visual inspection are classified according to the defect type; those that can be repaired are repaired, and those that cannot be repaired are scrapped.

[0102] S4.12 is the packaging process: Wrap the qualified power circuit board with pearl cotton, place the wrapped power circuit board into a vacuum packaging bag, vacuum the packaging bag with a vacuum packaging machine and heat seal it to form a vacuum-sealed environment inside the packaging bag to prevent damage to the product caused by collision, vibration, moisture or oxidation during transportation and storage, and at the same time facilitate storage and handling.

[0103] Please refer to Figure 4 This is another schematic flowchart illustrating a method for locally electroplating copper on a circuit board according to an embodiment of this application. Figure 4 As shown, the manufacturing method includes the following steps:

[0104] Material cutting → Inner layer pattern making → Inner layer drilling → Routing → Browning → Pressing → Routing edge forming → First routing of copper plate → Mechanical drilling → Deburring → Removing adhesive residue → Electroplating → Plate surface electroplating → Outer layer pattern making → Pattern electroplating → Outer layer alkaline etching → AOI inspection → Solder resist → Outer layer forming → Electrical testing → Final inspection → Packaging.

[0105] The specific implementation method for each step can be referred to the aforementioned implementation method for the fabrication of partial electroplating copper on a circuit board, and will not be repeated here.

[0106] In summary, this application provides a method for manufacturing a power circuit board with copper sidewalls in a half-hole, which has the following beneficial effects:

[0107] First, it significantly increases the effective shielding area of ​​the sidewall copper. This application transforms the originally planar sidewall slot into a non-planar structure with undulating surfaces by machining multiple semi-circular arcs on the sidewall slot walls around the finished unit. Simultaneously, a metallized copper layer is formed on the sidewall slot surface and the inner walls of the semi-circular arcs. This expands the effective shielding area of ​​the sidewall copper from the limited area of ​​the traditional planar structure (slot length × copper thickness) to the sum of the planar area and the area of ​​all the inner walls of the semi-circular arcs, greatly enhancing the absorption and reflection capabilities of the sidewall copper for electromagnetic waves.

[0108] Secondly, it significantly improves high-frequency EMI suppression capabilities. Compared to the single and limited electromagnetic wave reflection interface of existing planar straight-edge copper sidewalls, this application achieves multiple reflections and scattering of electromagnetic waves through the concave-convex structure formed by the semi-circular arc. This allows the electromagnetic waves to undergo multiple energy losses on the sidewall copper surface before propagating outward. At the same time, the concave-convex structure increases the loss path of guided waves propagating along the metal conductors at the board edge, effectively suppressing leakage of electromagnetic waves extending outward along power lines, signal lines, and grounding structures, and significantly reducing the electromagnetic radiation level of the power circuit board.

[0109] Third, the process modification is minimal and highly compatible with existing processes. This application only adds a step of drilling a semi-circular hole in the sidewall groove of the mechanical drilling process in the existing PCB manufacturing process. No new equipment or materials are required, the main framework of the original process flow is not changed, and the production time and cost are not significantly increased. It has good mass production feasibility and economy.

[0110] Based on the same inventive concept, this application also provides a power circuit board with copper sidewalls in a half-hole, which adopts the following... Figure 2 The power circuit board shown is manufactured using a method for producing a copper half-hole sidewall. The power circuit board has a sidewall groove on its edge, and the groove wall has an undulating structure formed by multiple half-hole arcs.

[0111] The power circuit board has a convex-concave structure formed by multiple semi-circular arcs on the side wall of the board edge. The side wall, bottom of the side wall, and inner wall of the semi-circular arcs are all covered with a continuous metallized copper layer, making the copper shielding layer of the side wall a three-dimensional structure. The effective shielding area is much larger than that of the traditional planar straight edge structure, which significantly improves the suppression capability of high-frequency EMI. At the same time, the structure is integrally formed by the above manufacturing method, which makes the structure stable, reliable, and has good mass production applicability.

[0112] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0113] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a power circuit board with copper sidewalls through a semi-hole, characterized in that, include: Provides multilayer copper-clad boards containing inner layer circuit patterns; Side wall grooves are milled around the finished unit of the multilayer copper-clad laminate; Using a mechanical drilling machine, through holes and tool holes are machined on the multilayer copper-clad laminate, and multiple semi-circular arcs are machined on the groove wall of the sidewall groove. A metallized copper layer is formed on the surface of the sidewall groove and the semi-circular arc of the hole, and a power circuit board is obtained through subsequent processing.

2. The method for manufacturing a power circuit board with copper sidewalls in a semi-hole according to claim 1, characterized in that, The provision of a multilayer copper-clad laminate containing inner layer circuit patterns includes: Provides an inner core board containing inner layer circuit patterns; Grooves are formed on the inner core plate; Copper busbars are fed into the tank, and the inner core board and the copper busbars are subjected to browning treatment to obtain the browned inner core board. The browned inner core board, prepreg, and copper foil are laminated together to form a multilayer copper-clad laminate.

3. The method for manufacturing a power circuit board with copper sidewalls in a semi-hole according to claim 2, characterized in that, The inner core board containing inner layer circuit patterns includes: Large sheets of wood are cut into multiple production boards, which are then cleaned by high-pressure water washing and baked. The surface of the production board is roughened, and then photosensitive ink is applied to the roughened surface. After exposure and development according to the design requirements, the copper plating outside the alignment pattern around the board edge is removed by etching to obtain the inner core board containing the inner layer circuit pattern.

4. The method for manufacturing a power circuit board with copper sidewalls in a semi-hole according to claim 2, characterized in that, After providing an inner layer core board containing inner layer circuit patterns, the method further includes: Use an optical positioning punching machine to punch rivet holes in the inner core board; The process involves laminating the browned inner core board, prepreg, and copper foil to form a multilayer copper-clad laminate, including... The core board, prepreg, and copper foil are stacked in sequence, and rivets are inserted into the rivet holes for riveting and fixing. Then, with the assistance of a mirror steel plate, the material is fed into a press and formed into a multi-layer copper-clad laminate by heating and pressing.

5. The method for manufacturing a power circuit board with copper sidewalls in a semi-hole according to claim 4, characterized in that, After forming a multilayer copper-clad laminate by heating and pressurizing, the method further includes: After the multilayer copper-clad laminate is removed from the press and cooled to room temperature, the edges of the multilayer copper-clad laminate are trimmed to obtain a multilayer copper-clad laminate of a preset size.

6. The method for manufacturing a power circuit board with copper sidewalls in a semi-hole according to claim 1, characterized in that, The process of forming a metallized copper layer on the surface of the sidewall groove and the semi-circular arc includes: The surface of the multilayer copper-clad laminate to be metallized is deburred and desmeared; the surface to be metallized includes the hole wall of the through hole, the hole wall of the tool hole, the groove surface of the side wall groove, and the inner wall of the semi-hole arc. A bottom copper layer is deposited on the surface to be metallized by chemical deposition. The copper layer is thickened on the underlying copper layer by electroplating.

7. The method for manufacturing a power circuit board with copper sidewalls in a semi-hole according to claim 1, characterized in that, The power circuit board obtained through subsequent processing includes: The outer layer circuit pattern is fabricated on the multilayer copper-clad laminate; The outer layer circuit pattern of the multilayer copper-clad laminate is inspected using an automated optical inspection machine. The surface of the qualified multilayer copper-clad laminate is roughened. After roughening, solder resist ink is applied to the surface. After exposure and development according to the design requirements, the unexposed copper surface area to be soldered is exposed. The multilayer copper-clad laminate is cut into at least one power circuit board using a forming milling cutter.

8. The method for manufacturing a power circuit board with copper sidewalls in a half-hole according to claim 7, characterized in that, The process of fabricating the outer layer circuit pattern of the multilayer copper-clad laminate includes: A dry film is applied to the surface of the multilayer copper-clad laminate using a pattern transfer method, revealing the outer layer circuit pattern. The copper layer of the outer circuit pattern is further thickened, and an anti-corrosion tin layer is electroplated. After removing the dry film using sodium hydroxide, the exposed copper surface is removed by etching solution and the tin layer is removed to expose the outer circuit pattern.

9. The method for manufacturing a power circuit board with copper sidewalls in a semi-hole according to claim 7, characterized in that, After cutting the multilayer copper-clad laminate into at least one power circuit board using a forming milling cutter, the method further includes: Electrical tests are performed on at least one power supply circuit board, and power supply circuit boards that pass the electrical tests are selected. The power circuit boards that pass the electrical test are visually inspected, and those that pass the visual test are selected. The power circuit boards that meet the appearance requirements are vacuum-packed.

10. A power circuit board with copper sidewalls in a semi-hole configuration, characterized in that, The power circuit board is manufactured using the method of making copper sidewalls with half-holes as described in any one of claims 1 to 9. The power circuit board has a sidewall groove on its edge, and the groove wall has an undulating structure formed by multiple semi-hole arcs.

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