Manufacturing method of circuit board with local thick copper and circuit board

Abstract

The invention provides a manufacturing method of a circuit board with local thick copper and the circuit board, and the manufacturing method comprises the steps: obtaining a main board of the circuit board, and carrying out the electroplating of the main board of the circuit board, and obtaining the electroplated main board of the circuit board; carrying out primary pattern transfer on the electroplated mainboard to expose a position needing to be electroplated, and carrying out primary pattern electroplating and tinning; performing secondary pattern transfer on the main board subjected to primary pattern electroplating, and exposing a target area needing to be subjected to thick copper manufacturing; performing tin stripping and secondary pattern electroplating and tin plating on the target area to enable the copper thickness of the target area to reach the target thickness; and removing the film, and forming a circuit pattern on the mainboard by adopting an alkaline etching mode. According to the method, when the circuit board with local thick copper is manufactured, the condition that the step position of the thick copper and the thin copper is corroded and scrapped is avoided, so that the quality of the circuit board is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of PCB boards, and in particular to a manufacturing method of a circuit board with locally thick copper and the circuit board. Background Art

[0002] Partially thickened copper PCBs are printed circuit boards with thickened copper layers in specific areas. By increasing the copper thickness in these areas, the board's current-carrying capacity is increased, thermal strain is reduced, and heat dissipation is optimized to meet the demands of high-current, high-power applications. Partially thickened copper PCBs are widely used in consumer electronics, automotive electronics, industrial automation equipment, robotics, and other fields.

[0003] In the existing production process of ultra-high-rise, ultra-high aspect ratio circuit boards, circuit boards with locally thick copper are prone to "broken necks" during production. This phenomenon is particularly prominent on boards with ultra-high aspect ratios (>20:1). This is because the conventional image electroplating alkaline etching process can only process boards with aspect ratios below 18:1 due to the characteristics of the electroplating tin solution itself, and cannot meet the production requirements of ultra-high aspect ratio boards. When using acid etching, the dry film cannot be effectively filled due to the step height difference between the thick copper area and other thin copper areas during the production process, resulting in solution penetration during etching and subsequent erosion. This phenomenon causes the etched copper wire to break or become thinner at the step position, resembling a "broken neck", which affects the quality and performance of the circuit board.

[0004] Therefore, there is a need to improve the existing method for manufacturing a circuit board with an ultra-high aspect ratio and locally thick copper to overcome the defects of the prior art. Summary of the Invention

[0005] In order to overcome the problems existing in the related art, one of the purposes of the present invention is to provide a method for manufacturing a circuit board with locally thick copper. This method can avoid corrosion and scrapping at the stepped position of thick copper and thin copper when manufacturing the circuit board with locally thick copper, thereby ensuring the quality of the circuit board.

[0006] A method for manufacturing a circuit board with locally thick copper, comprising:

[0007] Obtaining a circuit board mainboard, and performing POFV electroplating on the circuit board mainboard to obtain a circuit board mainboard after POFV electroplating;

[0008] Perform a pattern transfer on the motherboard after POFV electroplating to expose the position that needs to be electroplated, and then perform pattern electroplating and tin plating;

[0009] Perform secondary pattern transfer on the motherboard that has been electroplated with the first pattern to expose the target area that needs thick copper production;

[0010] Perform tin stripping and secondary pattern electroplating and tin plating on the target area to make the copper thickness of the target area reach the target thickness;

[0011] After stripping the film, alkaline etching is used to form circuit patterns on the mainboard.

[0012] In a preferred technical solution of the present invention, the secondary pattern transfer is performed on the mainboard that has been subjected to the primary pattern electroplating to expose the target area that needs to be processed with thick copper, including:

[0013] Drying the circuit board after pattern plating and tinning;

[0014] Apply protective film on the dried circuit board;

[0015] Expose the target area;

[0016] The target areas include areas where thick copper needs to be fabricated and locations where current balance is required.

[0017] In a preferred technical solution of the present invention, the balancing current position is close to the area where thick copper production is required;

[0018] During the secondary pattern electroplating process, a flow-guiding component is formed at the balance current position; and the cross section of the flow-guiding component is circular or elliptical.

[0019] In a preferred technical solution of the present invention, the step of obtaining a circuit board mainboard includes:

[0020] According to the design requirements of the circuit board, design the areas where thick copper and gold plating are required;

[0021] Make the substrate of the circuit board and drill the required through holes, blind holes and buried holes on the substrate;

[0022] Electroplating the drilled substrate;

[0023] Backdrill the substrate to remove excess copper from the plated through-holes;

[0024] All holes that are not plugged in are plugged with resin, and the plugged holes are ground and inspected;

[0025] Thinning the copper layer on the substrate surface and polishing the substrate surface;

[0026] The substrate is subjected to POFV electroplating to obtain a main board.

[0027] In a preferred technical solution of the present invention, after forming the circuit pattern on the mainboard by alkaline etching, the method further includes:

[0028] Select pre-plating treatment and pre-treat the area that needs gold plating;

[0029] Select silk screen wet film plating, and print a layer of wet film on the position where gold plating is not required;

[0030] Wet film exposure and development: Expose and develop the wet film after screen printing to remove the unexposed part of the wet film and expose the area that needs gold plating;

[0031] UV curing, using ultraviolet rays to cure the wet film;

[0032] Apply blue glue, cover the areas that are not to be gold-plated with gold-plated blue glue, and expose the areas that need to be gold-plated;

[0033] Gold plating: Gold plating is performed on the areas that require gold plating.

[0034] In a preferred technical solution of the present invention, after the gold plating, the method further comprises:

[0035] Remove the blue glue and remove the wet film used in the gold plating process to expose the entire motherboard;

[0036] Screen printing wet film, except for the position and hole where the gold-plated leads need to be etched, all other areas are screen printed with wet film, and the wet film after screen printing is exposed and developed, and the unexposed part of the wet film is removed to expose the gold-plated leads that need to be etched;

[0037] Dry film pattern transfer, exposing and developing the location where the gold-plated leads will be etched;

[0038] Lead etching: etching the gold-plated leads. It is necessary to ensure that the lead residue after etching is within the required specifications.

[0039] In a preferred technical solution of the present invention, after etching the gold-plated leads, the method further comprises:

[0040] Remove the film from the circuit board and perform subsequent cleaning and inspection to determine whether the quality of the circuit board is qualified.

[0041] One of the objects of the present invention is to provide a circuit board, which is manufactured using the manufacturing method of the circuit board with local thick copper as described above, wherein the PCB board with local thick copper includes a substrate layer, at least one side of the substrate layer is electroplated with a thick copper layer, and solder mask layers are provided on both sides of the thick copper layer; the thickness of the thick copper layer is greater than the thickness of the solder mask layer.

[0042] In a preferred technical solution of the present invention, the thick copper layer protrudes outward from the surface of the solder resist layer, and the protruding height is greater than 50 μm.

[0043] The beneficial effects of the present invention are:

[0044] The present invention provides a method for manufacturing a circuit board with locally thick copper. The method comprises: obtaining a circuit board mainboard and electroplating the circuit board mainboard to obtain an electroplated circuit board mainboard; performing a pattern transfer on the electroplated mainboard to expose the location to be electroplated, and performing a pattern electroplating and tinning; performing a secondary pattern transfer on the primary pattern-plated mainboard to expose the target area to be thickened copper; performing tin stripping and secondary pattern electroplating and tinning on the target area to achieve a target copper thickness in the target area; stripping the film and forming a circuit pattern on the mainboard using alkaline etching. The method increases the copper layer thickness of the thin copper area to the desired thickness through the primary pattern transfer and primary pattern electroplating, and then tins the area to be protected. Then, through the secondary pattern transfer and secondary pattern electroplating and tinning, the copper layer thickness of the thick copper area reaches the target thickness, while the thickness of other areas remains unchanged, thereby achieving the production of locally thickened copper patterns. This step-by-step process also effectively controls the uniformity of the copper layer thickness through the flow-guiding components during electroplating, avoiding problems such as rough copper surfaces and localized board burns caused by uneven current distribution during secondary pattern electroplating. Furthermore, alkaline etching, which uses an alkaline etchant, does not attack the tin layer, leaving the tin-protected areas unaffected during the etching process. This prevents erosion even at the stepped locations between thick and thin copper, thus preventing scrapping of the circuit board and improving production yields. Furthermore, only a single local thickening step is required to produce the locally ultra-thick copper printed circuit board of this embodiment.

[0045] The present application also provides a circuit board manufactured using the above-mentioned manufacturing method. The scrap rate and rework rate during the production process of the circuit board are low, and the use of local electroplating makes the production process more environmentally friendly, reduces production costs, and has reliable and stable quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of a method for manufacturing a circuit board with locally thick copper provided by the present invention;

[0047] Figure 2 This is a flow chart of obtaining a circuit board mainboard provided by the present invention. DETAILED DESCRIPTION

[0048] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present invention more thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0049] Example 1

[0050] like Figure 1-Figure 2 As shown, this embodiment provides a method for manufacturing a circuit board with locally thick copper, the method comprising the following steps:

[0051] S100, obtaining a circuit board mainboard, and electroplating the circuit board mainboard to obtain an electroplated circuit board mainboard;

[0052] Specifically, obtaining a circuit board mainboard includes:

[0053] S101. According to the circuit board design requirements, design the areas where thick copper and gold plating are required;

[0054] In this step, a BGA area can be designed that requires local thick copper and gold plating to meet other requirements such as high current density and high reliability.

[0055] S102, making a substrate for a circuit board, and drilling required through holes, blind holes, and buried holes on the substrate;

[0056] Select a suitable substrate material, such as glass fiber reinforced epoxy resin (FR-4). Drill the required through holes, blind vias, and buried vias on the substrate to meet circuit connection requirements. For example, drill blind vias with a diameter of 0.2 mm and through holes with a diameter of 0.5 mm.

[0057] S103, electroplating the drilled substrate. Electroplating the drilled substrate ensures that the copper thickness of the holes is uniform and meets the design requirements.

[0058] S104: Backdrill the substrate to remove excess copper from the plated through-holes. Backdrill the substrate to remove excess copper from the plated through-holes. For example, the backdrill depth is 0.2 mm. The backdrill depth can be designed based on high-speed signal transmission requirements to ensure signal transmission speed and reduce signal distortion.

[0059] S105: All unplugged holes are filled with resin, and the plugged holes are ground and inspected. All unplugged holes are filled with resin, and the plugged holes are ground to ensure the hole openings are flat. Automated optical inspection (AOI) equipment is used to inspect the plugged holes to ensure the fullness of the plugged holes.

[0060] S106. Thinning the copper layer on the substrate surface and polishing the substrate surface. Thinning the copper layer on the substrate surface, for example, reducing the thickness of the copper layer from 35 μm to 18 μm. Then, polishing the substrate surface to remove the surface oxide layer and impurities, thereby improving the surface cleanliness and conductivity.

[0061] S107: POFV electroplating is performed on the resin-filled holes on the substrate to obtain a main board. Copper electroplating is performed on the resin-filled holes on the substrate to encapsulate the resin in a copper layer, preventing moisture absorption during long-term use and improving the reliability of the holes. The copper at the required thin copper locations reaches the specified design copper thickness. After the above steps, a circuit board main board is obtained after electroplating.

[0062] S200, performing a pattern transfer on the electroplated mainboard to expose the position requiring electroplating, and performing pattern electroplating and tinning;

[0063] A pattern transfer is performed on the main board of the circuit board after electroplating. Using photolithography technology, the locations that need to be electroplated (such as thick copper areas and thin copper areas) are covered with a photoresist film to expose the areas that need to be electroplated. The circuit board after a pattern transfer is subjected to a pattern electroplating. In the electroplating tank, the thickness of the copper layer in the exposed area that needs to be electroplated is increased by controlling the current density and electroplating time. For example, the thickness of the copper layer of the original main board is increased from 35μm to 50μm. Tin plating is then performed, and the thickness of the tin layer is about 1μm. The purpose of tin plating is to protect the copper layer in these areas during the subsequent etching process to prevent it from being etched.

[0064] S300: Perform a secondary pattern transfer on the primary pattern-plated motherboard to expose the target areas where thick copper is to be processed. A secondary pattern transfer is performed on the primary pattern-plated circuit board. Photolithography is again used to cover the areas where thick copper is not to be processed with a photoresist film, leaving only the target areas where thick copper is to be processed exposed. For example, the thin copper areas that have been protected by tin plating and the other areas to be etched are covered, leaving only the thick copper areas exposed.

[0065] S400, the target area is subjected to tin stripping and secondary graphic electroplating and tin plating, so that the copper thickness of the target area reaches the target thickness; the target area is subjected to tin stripping treatment to remove the tin layer on the target area and expose the copper surface. This step is to thicken the copper layer in the target area in the subsequent secondary graphic electroplating. The target area is subjected to secondary graphic electroplating and tin plating. In the electroplating tank, by controlling the current density and electroplating time, the copper layer thickness in the target area is further increased and finally reaches the target thickness. For example, the copper layer thickness in the thick copper area is increased from 50μm after the primary graphic electroplating to 100μm to meet the design requirements of local thick copper. Then tin plating is performed, and the tin layer thickness is about 1μm. Tin plating is to tin the copper surface and side after the thickening of the copper. Therefore, the stepped positions of thin copper and thick copper are plated with a tin layer to protect the copper layer in these areas during the subsequent etching process to prevent them from being etched, and to ensure that the stepped positions of thick copper and thin copper do not experience corrosion.

[0066] S500, stripping the film and forming a circuit pattern on the mainboard using alkaline etching.

[0067] After stripping the film, alkaline etching is used to form the circuit pattern on the motherboard. The circuit board is placed in an alkaline etching solution. By controlling the composition, temperature, and etching time of the etching solution, the areas not covered by the tin layer are etched away, forming the desired circuit pattern. Alkaline etching solutions do not attack the tin layer, so the tin-protected areas are not affected during the etching process, thus avoiding the possibility of corrosion and scrapping due to gaps that cannot be filled by acidic etching dry film.

[0068] The above-mentioned method for manufacturing a circuit board with locally thick copper increases the thickness of the copper layer in the thin copper area to the required thickness through a single pattern transfer and a single pattern electroplating and tinning, and tin-plating is performed on the area to be protected. Then, a secondary pattern transfer and a secondary pattern electroplating and tinning are performed to achieve the target thickness of the copper layer in the thick copper area, and the thickness of other areas will not change. The thick copper surface and the stepped positions between the thin copper and the thick copper are all plated with a tin layer, and alkaline etching is used. The alkaline etching solution will not corrode the tin layer, so during the etching process, the tin-protected area will not be affected. In this way, even at the stepped positions between the thick copper and the thin copper, no corrosion phenomenon will occur, resulting in a "broken neck" phenomenon at the connection between the local thick copper area and the thin copper area, thereby avoiding the scrapping of the circuit board and improving the production qualification rate.

[0069] In a specific embodiment, the secondary pattern transfer is performed on the mainboard that has been subjected to the primary pattern electroplating to expose the target area that needs to be processed with thick copper, including:

[0070] Drying the circuit board after pattern plating and tinning;

[0071] Apply protective film on the dried circuit board;

[0072] Expose the target area;

[0073] The target areas include areas where thick copper needs to be fabricated and locations where current balance is required.

[0074] Specifically, the circuit board after the first pattern electroplating and tin plating is dried to ensure that the surface is dry and prepare for the subsequent film lamination and development steps. A protective film is affixed to the dried circuit board. The protective film has good adhesion and etching resistance and can protect the areas where thick copper is not required. Using photolithography technology, the target area where thick copper is required is developed and exposed. The target area includes the area where thick copper is required and the balancing current position. The balancing current position is close to the area where thick copper is required, and is used to share the current during the secondary pattern electroplating process to ensure uniform current distribution.

[0075] Furthermore, the balancing current position is close to the area where thick copper production is required;

[0076] During the secondary pattern electroplating process, a flow-guiding component is formed at the balance current position; and the cross section of the flow-guiding component is circular or elliptical.

[0077] By setting a balanced current position near the thick copper area and forming a flow-guiding component during the secondary graphic electroplating process, the current can be effectively shared to ensure uniform current distribution. The cross-section of the flow-guiding component is circular or elliptical, with a size of approximately 0.5mm×0.5mm, which can effectively avoid the problems of rough copper surface and local burning of the board caused by excessive local current density, further improving the quality and reliability of the circuit board. It should be noted that the size of the flow-guiding component of the present application can be adjusted as needed. For example, the cross-sectional size of the flow-guiding component can be 0.3mm-1mm×0.4-1.2mm. Based on whether the flow-guiding component affects the electrical performance of the entire circuit board, the flow-guiding component can be etched away or not etched during the alkaline etching process.

[0078] Furthermore, after forming the circuit pattern on the mainboard by alkaline etching, the method further includes:

[0079] Tin stripping is to remove the tin layer plated in the primary pattern electroplating and the secondary pattern electroplating to expose the copper layer.

[0080] Pre-treatment of the selected areas to be gold plated, including cleaning and activation, to ensure that the surface has good conductivity and adhesion.

[0081] Select silk screen wet film plating, print a layer of wet film on the positions that are not to be gold-plated; print a layer of wet film on the positions that are not to be gold-plated to prevent these areas from being plated with gold during the gold plating process.

[0082] Wet film exposure and development: The wet film after screen printing is exposed and developed to remove the unexposed part of the wet film and expose the area that needs gold plating.

[0083] UV curing uses ultraviolet rays to cure the wet film to ensure the stability and protective effect of the wet film layer.

[0084] Apply blue glue, cover the areas that are not to be gold-plated with gold-plated blue glue, and expose the BGA areas that need to be gold-plated; blue glue has good adhesion and corrosion resistance, and can protect the areas that are not to be gold-plated.

[0085] BGA gold plating, gold plating is performed on the BGA areas that need gold plating. Gold plating is performed on the BGA areas that need gold plating to ensure that the gold plating layer is uniform and dense to meet the design requirements.

[0086] Furthermore, after the BGA is gold-plated, the process further comprises:

[0087] Remove the blue glue and fade away the wet film used in the gold plating process to expose the gold-plated leads and prepare for the subsequent etching process.

[0088] Screen-print the wet film on all areas except for the holes and locations where the gold-plated leads need to be etched. This step ensures that the areas to be etched are exposed, while other areas are protected. Furthermore, due to the good fluidity of the wet film, it can effectively cover the junctions between the thick copper areas and the thin copper areas, thus preventing corrosion during the etching of the gold-plated leads.

[0089] Wet film exposure and development: Expose and develop the wet film after screen printing to remove the ink in the unexposed part and expose the gold-plated leads that need to be etched;

[0090] The dry film pattern is transferred, and the position where the gold-plated leads are to be etched is exposed and developed, and the other areas are covered with dry film, including the positions of all holes, in preparation for the subsequent etching process.

[0091] Lead etching, etching the gold-plated leads, and ensure that the protrusion of the gold-plated nickel layer of the leads after etching is minimal, so that the overhanging gold of the circuit board is less than 2mi l, ensuring that the overhanging gold is within a reasonable range.

[0092] In this application, when gold plating is performed in areas where thick copper is required, the copper thickness of the gold-plated conductor is the normal thickness after the pattern electroplating is completed once. When etching the leads after the gold plating is completed, the copper thickness at the location of the gold-plated leads is of normal thickness, so there is no need to extend the etching time during etching. The shorter the time the gold-plated area is in the etching solution, the smaller the amount of side etching, thus avoiding the situation where the gold-plated area has overhanging gold exceeding the standard (overhanging gold is less than 2ml), thereby ensuring that the overhanging gold is within a reasonable range and ensuring the quality of the product.

[0093] Furthermore, after etching the gold-plated leads, the method further comprises:

[0094] Carry out subsequent cleaning and inspection of the circuit board to determine whether the quality of the circuit board is qualified.

[0095] In this step, the circuit board is cleaned to remove surface residues and impurities to ensure a clean surface. Automated optical inspection (AOI) equipment is used to inspect the circuit board to determine if the quality of the circuit board is acceptable.

[0096] Example 2

[0097] This embodiment provides a circuit board, which is manufactured using the manufacturing method of a circuit board with locally thick copper as described above. The PCB board with locally thick copper includes a substrate layer, at least one side of the substrate layer is electroplated with a thick copper layer, and solder mask layers are provided on both sides of the thick copper layer; the thickness of the thick copper layer is greater than the thickness of the solder mask layer.

[0098] More specifically, the thick copper layer protrudes outward from the surface of the solder resist layer, and the protrusion height is greater than 50 μm.

[0099] Specifically, the thickness of the thick copper layer of the circuit board of the present application is greater than the thickness of the conventional copper layer to meet the requirements of high current density and high reliability. For example, the thickness of the thick copper layer can reach 100μm. Solder masks are provided on both sides of the thick copper layer. The thickness of the solder mask is generally 40-60μm, which is used to protect the copper layer and prevent oxidation. The thick copper layer protrudes outward from the surface of the solder mask, and the protrusion height is greater than 50μm. This design ensures that the thick copper area has sufficient height during welding and use to meet specific application requirements, such as BGA pads need to be higher than the solder mask to ensure good chip mounting requirements.

[0100] The thick copper layer of this circuit board effectively improves the current-carrying capacity of the circuit board, making it suitable for high-current density applications such as high-performance computing and communications equipment. The thick copper layer protrudes outward from the solder mask surface, with a height greater than 50μm. This design ensures good contact between the BGA pads during soldering, improving soldering quality and reliability.

[0101] In addition, the scrap rate and rework rate during the production process of the circuit board are low, thereby reducing production costs, and the quality is reliable and stable.

[0102] Unless otherwise specifically stated, the relative arrangement, numerical expression and numerical value of the parts and steps set forth in these embodiments do not limit the scope of the application. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a restriction. Therefore, other examples of exemplary embodiments can have different values. It should be noted that: similar reference numerals and letters represent similar items in the accompanying drawings below, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in the accompanying drawings subsequently.

[0103] It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in a figure is inverted, a device described as "above" or "above" another device or structure would then be positioned "below" or "beneath" the other device or structure. Thus, the exemplary term "above" can encompass both the orientations of "above" and "below." The device may also be oriented in other different ways (rotated 90 degrees or at other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0104] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0105] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a circuit board with locally thick copper, characterized in that: include: Obtaining a circuit board mainboard, and electroplating the circuit board mainboard to obtain an electroplated circuit board mainboard; Perform a pattern transfer on the electroplated motherboard to expose the location that needs to be electroplated, and then perform pattern electroplating and tinning; Perform secondary pattern transfer on the motherboard that has been electroplated with the first pattern to expose the target area that needs thick copper production; Perform tin stripping and secondary pattern electroplating and tin plating on the target area to make the copper thickness of the target area reach the target thickness; After stripping the film, alkaline etching is used to form circuit patterns and gold-plated leads on the mainboard.

2. The method for manufacturing a circuit board with locally thick copper according to claim 1, wherein: The secondary pattern transfer is performed on the mainboard that has been subjected to the primary pattern electroplating to expose the target area that needs to be processed with thick copper, including: Drying the circuit board after pattern plating and tinning; Apply protective film on the dried circuit board; Expose the target area; The target areas include areas where thick copper needs to be fabricated and locations where current balance is required.

3. The method for manufacturing a circuit board with locally thick copper according to claim 2, wherein: The balancing current position is close to the area where thick copper production is required; During the secondary pattern electroplating process, a flow-guiding component is formed at the balance current position; and the cross section of the flow-guiding component is circular or elliptical.

4. The method for manufacturing a circuit board with locally thick copper according to claim 1, wherein: The obtaining of the circuit board mainboard includes: According to the design requirements of the circuit board, design the areas where thick copper and gold plating are required; Make the substrate of the circuit board and drill the required through holes, blind holes and buried holes on the substrate; Electroplating the drilled substrate; Backdrill the substrate to remove excess copper from the plated through-holes; All holes that are not plugged in are plugged with resin, and the plugged holes are ground and inspected; Thinning the copper layer on the substrate surface and polishing the substrate surface; The substrate is subjected to POFV electroplating to obtain a main board.

5. The method for manufacturing a circuit board with locally thick copper according to any one of claims 1 to 4, characterized in that: After forming the circuit pattern and the gold-plated leads on the mainboard by alkaline etching, the method further includes: Select pre-plating treatment and pre-treat the area that needs gold plating; Select silk screen wet film plating, and print a layer of wet film on the position where gold plating is not required; Wet film exposure and development: Expose and develop the wet film after screen printing to remove the unexposed part of the wet film and expose the area that needs gold plating; UV curing, using ultraviolet rays to cure the wet film; Apply blue glue, cover the areas that are not to be gold-plated with gold-plated blue glue, and expose the areas that need to be gold-plated. The areas that need to be gold-plated include local thick copper areas and non-thick copper areas; Gold plating: Gold plating is performed on the areas that require gold plating.

6. The method for manufacturing a circuit board with locally thick copper according to claim 5, wherein: After the gold plating, the invention further comprises: Remove the blue glue and remove the wet film used in the gold plating process to expose the entire motherboard; Screen printing wet film, except for the position and hole where the gold-plated leads need to be etched, all other areas are screen printed with wet film, and the wet film after screen printing is exposed and developed, and the unexposed part of the wet film is removed to expose the gold-plated leads that need to be etched; Dry film pattern transfer, exposing and developing the location where the gold-plated leads will be etched; Lead etching, etching of gold-plated leads.

7. The method for manufacturing a circuit board with locally thick copper according to claim 5, wherein: After etching the gold-plated leads, the method further comprises: Remove the film from the circuit board and perform subsequent cleaning and inspection to determine whether the quality of the circuit board is qualified.

8. A circuit board, characterized in that: The PCB with locally thick copper is manufactured using the manufacturing method of any one of claims 1 to 7, wherein the PCB with locally thick copper includes a substrate layer, at least one side of the substrate layer is electroplated with a thick copper layer, and solder mask layers are provided on both sides of the thick copper layer; the thickness of the thick copper layer is greater than the thickness of the solder mask layer.

9. The PCB board with locally thick copper according to claim 8, characterized in that: The thick copper layer protrudes outward from the surface of the solder resist layer, and the protrusion height is greater than 50 μm.

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