Local copper thick circuit board and manufacturing method thereof

Abstract

The embodiment of the invention provides a local copper thick circuit board and a manufacturing method thereof. The local copper thickness circuit board comprises a laminated plate, a second conductive layer and a metal column, the laminated plate comprises an insulating layer and a first conductive layer covering at least one side of the insulating layer, at least one groove is formed in the first conductive layer, and the groove penetrates through the first conductive layer and extends into the insulating layer; the second conducting layer covers the outer side of the first conducting layer and the interior of the first groove, the metal column is arranged in the second groove, and the metal column is fixedly connected with the second conducting layer; and the outer side surface of the metal column and the outer side surface of the second conductive layer covering the first conductive layer are positioned on the same plane. The local copper thick circuit board is used for achieving the technical effects that the local thickness of the circuit board is increased and no height difference is generated.

Description

Technical Field

[0001] The present application relates to the technical field of printed circuit boards, and in particular to a locally copper-thick circuit board and a manufacturing method thereof. Background Art

[0002] In order to meet the requirements of high current and heat dissipation, the copper thickness of some areas of the outer circuit layer of the printed circuit board (PCB) needs to be increased.

[0003] Currently, the method of achieving local copper thickness is mostly to use direct electroplating on the surface of the outer circuit layer. This local copper thickness process will cause the surface of the outer circuit layer to have height differences, affecting the SMT (Surface Mount Technology) mounting. Summary of the Invention

[0004] The embodiments of the present application provide a circuit board with locally thick copper and a method for manufacturing the same, so as to achieve the technical effect of locally thickening the circuit board without generating height differences.

[0005] In the first aspect, an embodiment of the present application provides a locally copper-thick circuit board, comprising: a laminated plate, a second conductive layer and a metal column, the laminated plate comprising an insulating layer and a first conductive layer covering at least one side of the insulating layer, at least one first groove being provided on the first conductive layer, the first groove penetrating the first conductive layer and extending into part of the insulating layer; the second conductive layer covering the outer side of the first conductive layer and the first groove, the metal column being arranged in the second groove, and the metal column being fixedly connected to the second conductive layer, and the outer side surface of the metal column and the outer side surface of the second conductive layer covering the first conductive layer are located in the same plane.

[0006] Optionally, the second conductive layer and the metal column are formed integrally.

[0007] Optionally, both sides of the pressing plate are covered with a first conductive layer, each first conductive layer is provided with the groove, and the outer side of each first conductive layer is covered with the metal layer.

[0008] Optionally, the insulating layer includes a first insulating layer, a second insulating layer and a substrate, and the first insulating layer and the second insulating layer cover two sides of the substrate respectively.

[0009] Optionally, the substrate includes at least one of an inner conductive layer and an inner insulating layer.

[0010] In a second aspect, an embodiment of the present application provides a method for manufacturing a locally copper-thick circuit board, comprising the following steps:

[0011] Providing a laminated plate, the laminated plate comprising an insulating layer and a first conductive layer covering at least one side of the insulating layer;

[0012] Processing a groove at a first preset position on the outer side of the first conductive layer, wherein the groove penetrates the first conductive layer and extends into the insulating layer;

[0013] Performing an overall electroplating process on the pressed plate so that the groove and the outer side of the first conductive layer are covered with a conductive material to form a second conductive layer;

[0014] Covering the surface of the second conductive layer with a first dry film layer, wherein the first dry film layer is formed with a first avoidance hole for avoiding the groove, the first avoidance hole being larger than the groove so that the notch of the groove is located within the first avoidance hole;

[0015] Performing a partial electroplating treatment on the groove so that the groove and the first avoidance hole are filled with metal material to form a metal column;

[0016] removing the first dry film layer;

[0017] The second conductive layer and the metal column are subjected to copper reduction processing so that the outer side of the second conductive layer and the outer side of the metal column are located in the same plane.

[0018] Optionally, machining a groove at a first preset position on the outer side of the first conductive layer, wherein the groove penetrates the first conductive layer and extends into the first conductive layer, comprises the following steps:

[0019] Marking a first preset position of the groove on the outer side of the first conductive layer by developing, and applying a dry film on the outer side of the first conductive layer, with the dry film exposing the first preset position;

[0020] Etching the first preset position to form a first groove, wherein the first groove exposes the insulating layer;

[0021] Cutting a second groove in the exposed substrate by laser, wherein the second groove is connected to the first groove, and the first groove and the second groove together constitute the groove;

[0022] The dry film is removed, and the groove wall of the groove is subjected to a de-glue treatment.

[0023] Optionally, before the entire press plate is electroplated, the following steps are further included:

[0024] The inner wall of the groove is subjected to copper plating treatment so that a layer of basic copper is attached to the inner wall of the groove.

[0025] Optionally, performing copper reduction processing on the second conductive layer so that an outer side of the second conductive layer and an outer side of the metal pillar are located in the same plane includes:

[0026] A second dry film layer is covered on the surface of the second conductive layer; the second dry film layer is formed with a second avoidance hole for avoiding the groove, the second avoidance hole being larger than the groove and smaller than the first avoidance hole, so that the edge of the metal column covers the second dry film layer;

[0027] performing chemical copper reduction on the metal pillars not covered by the second dry film layer;

[0028] The second conductive layer after chemical copper reduction and the metal column are ground flat so that the outer side of the second conductive layer and the outer side of the metal column are located in the same plane.

[0029] Optionally, a height difference between an outer side surface of a portion of the second conductive layer not covered by the second dry film layer after chemical copper reduction and an outer side surface of a portion of the second conductive layer covered by the second dry film layer is 5-20 μm.

[0030] The beneficial effects of the present application are as follows: a locally copper-thick circuit board and a manufacturing method thereof provided in an embodiment of the present application, by opening a groove in the first conductive layer and extending it into the insulating layer, and filling the groove with a metal column, the metal column can absorb the heat of the first conductive layer and the second conductive layer and increase the current-carrying capacity, thereby increasing the conductivity and heat dissipation performance of the first conductive layer at the position where the metal column is located, realizing local thickening of the first conductive layer, and because the thickening direction is toward the insulating layer, the metal column will not cause a height difference between the thickened position and the non-thickened position of the first conductive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0032] Figure 1 A schematic diagram of the cross-sectional structure of a partially copper-thick circuit board provided in this application;

[0033] Figure 2 A flow chart of the method for manufacturing a locally thick copper circuit board provided in this application;

[0034] Figure 3 This is a schematic diagram of the initial structure of the press plate in the method for manufacturing a locally copper-thick circuit board provided in this application;

[0035] Figure 4 This is a schematic diagram of the cross-sectional structure of the press plate after grooves are formed in the method for manufacturing a locally copper-thick circuit board provided in this application;

[0036] Figure 5 This is a schematic diagram of the structure of the laminate after overall electroplating in the method for manufacturing a locally copper-thick circuit board provided in this application;

[0037] Figure 6 This is a schematic diagram of the structure of the press plate after local electroplating in the method for manufacturing a locally copper-thick circuit board provided in this application;

[0038] Figure 7 This is a more specific flow chart of step S20 in the method for manufacturing a locally thick copper circuit board provided in this application;

[0039] Figure 8 This is a more specific flow chart of step S30 in the method for manufacturing a locally thick copper circuit board provided in this application;

[0040] Figure 9 This is a more specific flow chart of step S40 in the method for manufacturing a locally thick copper circuit board provided in this application;

[0041] Figure 10 This is a more specific flow chart of step S50 in the method for manufacturing a locally thick copper circuit board provided in this application;

[0042] Figure 11 This is a more specific flow chart of step S60 in the method for manufacturing a locally copper-thick circuit board provided in this application.

[0043] Reference numerals:

[0044] 100 - pressing plate; 110 - insulating layer; 111 - first insulating layer; 112 - second insulating layer; 113 - base material; 1131 - inner conductive layer; 1132 - inner insulating layer; 120 - first conductive layer; 121 - first groove;

[0045] 200 - second conductive layer; 210 - second groove;

[0046] 300-metal column;

[0047] 400-Blind hole.

[0048] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0049] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0050] In the prior art, to meet high current and heat dissipation requirements, printed circuit boards typically thicken a portion of their outer circuit layers through electroplating. This allows the thickened areas to carry greater current and provide improved heat dissipation. However, this localized thickening method typically involves direct electroplating on the surface of the outer circuit layers, resulting in a height difference between the thickened and non-thickened areas, which can affect subsequent SMT placement.

[0051] In view of this, the embodiments of the present application provide a locally copper-thick circuit board and a manufacturing method thereof, which opens a groove on the surface of the outer circuit layer and fills the groove with metal pillars, thereby achieving local thickening of the outer circuit layer through the metal pillars.

[0052] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0053] like Figure 1 As shown, the present application provides, in a first aspect, a partially copper-thick circuit board, comprising a laminate 100, a second conductive layer 200, and a metal pillar 300. The laminate 100 comprises an insulating layer 110 and a first conductive layer 120 covering at least one side of the insulating layer 110. The first conductive layer 120 is provided with at least one first groove 121, which penetrates the first conductive layer 120 and extends into a portion of the insulating layer 110. The second conductive layer 200 covers the first conductive layer 120 and the first groove 121, and the second conductive layer 200 covering the first groove 121 forms a second groove 210. The metal pillar 300 is disposed in the second groove 210 and is fixedly connected to the second conductive layer 200. The outer side surface of the metal pillar 300 and the outer side surface of the second conductive layer 200 covering the first conductive layer 120 are located in the same plane.

[0054] In the above technical solution, a space capable of thickening the circuit is formed by opening the first groove 121 in the first conductive layer 120 and extending the first groove 121 into the insulating layer 110 . By covering the second conductive layer 200 in the first conductive layer 120 and the first groove 121, on the one hand, the entire second conductive layer 200 can be made into a continuous structure. On the other hand, the second groove 210 constructed by the second conductive layer 200 covered in the first groove 121 can accommodate the metal pillar 300. After the metal pillar is fixedly connected to the first conductive layer 120 and the second conductive layer 200, the metal pillar 300 can absorb the heat of the first conductive layer 120 and the second conductive layer 200 and increase the current carrying capacity, thereby increasing the conductivity and heat dissipation performance of the first conductive layer 120 at the location of the metal pillar 300, and realizing local thickening of the first conductive layer 120. Moreover, since the thickening direction is toward the inside of the insulating layer 110, and the outer side surface of the metal pillar 300 is located in the same plane as the outer side surface of the second conductive layer 200 covering the first conductive layer 120, the metal pillar 300 will not cause a height difference between the thickened position and the non-thickened position of the first conductive layer 120.

[0055] It should be noted that the first conductive layer 120 and the second conductive layer 200 can serve together as an outer circuit layer, wherein the first conductive layer 120 can be a metal sheet on which the circuit required for the printed circuit board can be formed. The circuit formed thereon can be formed in advance by development and etching before covering the insulating layer 110, or can be formed by development and etching after covering the insulating layer 110. The second conductive layer 200 can be an electroplating layer, which, after covering the first conductive layer 120, can reduce the electromagnetic interference to the circuit formed on the first conductive layer 120. The parts of the first conductive layer 120 that need to be thickened can be adjusted accordingly according to the design requirements of the circuit board. Of course, in other embodiments, the second conductive layer 200 can also serve as a circuit layer to form the required circuit.

[0056] In addition, the insulating layer 110 is a plate-shaped structure with an insulating property on a side close to the first conductive layer 120 , so that the insulating layer 110 can be in insulating contact with the first conductive layer 120 .

[0057] Optionally, the first conductive layer 120 may be made of copper or gold, which is not specifically limited in this application.

[0058] Optionally, the material of the first conductive layer 120 and the second conductive layer 200 can be the same, that is, the same metal; the material of the first conductive layer 120 and the second conductive layer 200 can also be different, that is, different metals; this application does not make any specific limitations on this.

[0059] In this embodiment, the first conductive layer 120 and the second conductive layer 200 are both made of copper to obtain better heat dissipation and current conduction performance.

[0060] In some optional embodiments, the insulating layer 110 is covered on both opposite sides with a first conductive layer 120, each first conductive layer 120 is provided with a first groove 121, and each first conductive layer 120 is covered with a second conductive layer 200, and each second groove 210 constructed by the second conductive layer 200 is provided with a metal column 300.

[0061] By arranging the second conductive layer 200 and the metal pillar 300 on both sides of the insulating layer 110, outer circuit layers can be formed on both sides of the circuit board, and the outer circuit layers have local copper thickness, thereby meeting more circuit requirements.

[0062] Optionally, the first grooves 121 on the first conductive layer 120 on both sides of the insulating layer 110 are mirror-imaged, so that the outer circuit layers on both sides of the circuit board can obtain mirror-imaged local copper thickness circuit boards.

[0063] In some optional embodiments, the insulating layer 110 includes a first insulating layer 111 , a second insulating layer 112 and a substrate 113 , and the first insulating layer 111 and the second insulating layer 112 respectively cover opposite sides of the substrate 113 .

[0064] The insulating layer 110 constructed by the first insulating layer 111 , the second insulating layer 112 and the base material 113 can realize an insulating function by utilizing the first insulating layer 111 and the second insulating layer 112 .

[0065] In some optional embodiments, the substrate 113 includes at least one of an inner conductive layer 1131 and an inner insulating layer 1132 .

[0066] It can be understood that the inner conductive layer 1131 is made of a metal material, which can form an inner layer circuit. The inner insulating layer 1132 is made of an insulating material, which can play an insulating role. The substrate 113 can be a single-layer structure or a multi-layer structure, and this application does not make specific restrictions on this. In addition, when the substrate 113 is a single-layer structure, it can include one of the inner conductive layer 1131 or the inner insulating layer 1132. When the substrate 113 is a multi-layer structure, it can include an inner conductive layer 1131 and an inner insulating layer 1132, and the inner conductive layer 1131 and the inner insulating layer 1132 are alternately stacked.

[0067] In some optional embodiments, the insulating layer 110 may also be a single-layer structure, that is, the insulating layer 110 is made of only one layer of insulating material.

[0068] like Figures 2 to 11As shown, the present application in a second aspect provides a method for producing a local copper thick circuit board, for producing the above-mentioned local copper thick circuit board, comprising the following steps;

[0069] S10: Provide a laminated plate 100 , wherein the laminated plate 100 includes an insulating layer 110 and a first conductive layer 120 covering at least one side of the insulating layer 110 .

[0070] like Figure 3 As shown, the laminated plate 100 is made of at least a first conductive layer 120 and an insulating layer 110 through a lamination process, so that the first conductive layer 120 and the insulating layer 110 can be relatively fixed. A circuit can be formed on the first conductive layer 120 by etching.

[0071] S20 : ​​forming at least one first groove 121 on the first conductive layer 120 , and allowing the first groove 121 to penetrate the first conductive layer 120 and extend into a portion of the insulating layer 110 .

[0072] like Figure 4 As shown, the first groove 121 opened on the first conductive layer 120 is opened on the side of the first conductive layer 120 away from the insulating layer 110. The opening position and the number of the first groove 121 can be adjusted and determined according to the position and number of local thickening required for the circuit board. After determining the position of the first groove 121, the first groove 121 can be processed. Extending the first groove 121 into the insulating layer 110 can, on the one hand, deepen the depth of the first groove 121, so that the subsequent metal column 300 has a larger volume, thereby obtaining better heat dissipation performance and current carrying performance. On the other hand, since the first groove 121 does not penetrate the insulating layer 110, the end of the conductive column filled in the subsequent first groove 121 located in the first groove 121 can be wrapped and insulated by the first groove 121.

[0073] In this embodiment, the first groove 121 extends in a direction perpendicular to the surface of the first conductive layer 120, thereby enabling the metal pillar 300 subsequently formed in the first groove 121 to have a better flow-conducting effect. Of course, in other embodiments, the first groove 121 may extend in a direction oblique to the surface of the first conductive layer 120.

[0074] S30 : covering the first conductive layer 120 and the first groove 121 with the second conductive layer 200 , and forming a second groove 210 with the second conductive layer 200 covered in the first groove 121 .

[0075] By covering the second conductive layer 200 in the first conductive layer 120 and the first groove 121 , the second conductive layer 200 can completely cover at least one side surface of the laminate 100 , thereby better reducing electromagnetic interference to the first conductive layer 120 .

[0076] S40 : Disposing a metal pillar 300 in the second groove 210 and fixing the metal pillar 300 to the first conductive layer 120 and the second conductive layer 200 , with the outer side of the metal pillar 300 and the outer side of the second conductive layer 200 covering the first conductive layer 120 being in the same plane.

[0077] A metal pillar 300 is disposed within the second groove 210. The metal pillar 300 contacts the first conductive layer 120 and the second conductive layer 200, enabling heat conduction. This provides the first conductive layer 120 with a larger heat dissipation area, resulting in improved heat dissipation performance. Furthermore, the metal pillar 300 is capable of carrying current, thereby enhancing the current-carrying capacity of the first conductive layer 120. Furthermore, the outer surface of the metal pillar 300 is coplanar with the outer surface of the second conductive layer 200 covering the first conductive layer 120. Therefore, the metal pillar 300 does not cause a height difference between the thickened and non-thickened portions of the first conductive layer 120.

[0078] In some optional embodiments, at least one first groove 121 is opened on the first conductive layer 120 , and the first groove 121 penetrates the first conductive layer 120 and extends into a portion of the first conductive layer 120 , including the following steps.

[0079] S21: Marking a first preset position of the first groove 121 on the outer side of the first conductive layer 120 by developing, and attaching a first dry film to the outer side of the first conductive layer 120, with the first dry film exposing the first preset position.

[0080] By developing, the position where the first groove needs to be opened (i.e., the position where local thickening is required, the first preset position) can be marked on the outer surface of the first conductive layer 120. When the first dry film is subsequently applied to the outer surface of the first conductive layer 120, the first preset position can be avoided. That is, the first dry film is applied to the outer surface of the first conductive layer 120 except for the first preset position to protect it, and the first preset position is not applied with the first dry film.

[0081] S22: Etching the first preset position to form an etching groove, where the etching groove exposes the insulating layer 110.

[0082] Since the first dry film is not applied to the first preset position and the exposed first conductive layer 120 is made of metal, the first preset position can be directly etched to form an etching groove.

[0083] Optionally, the width of the etching groove ranges from 0.1 mm to 0.2 mm.

[0084] S23: Cutting the exposed insulating layer 110 into a cutting groove extending into a portion of the insulating layer by laser cutting, so that the cutting groove and the etching groove together form a first groove 121.

[0085] Laser processing of the insulating layer can better control the processing depth and cut grooves of the required depth.

[0086] Optionally, the cutting groove has a width ranging from 0.1 mm to 0.2 mm and a depth ranging from 0.03 mm to 0.10 mm.

[0087] S24: removing the first dry film and performing a debonding process on the groove wall of the first groove 121.

[0088] After removing the first dry film, the walls of the first groove 121 are debonded to remove impurities from the walls of the first groove 121, particularly impurities adhering to the walls and bottom of the second first groove 121 during the laser cutting process. Debonding the first groove 121 makes it easier to deposit metal. The first dry film can be removed chemically.

[0089] Optionally, the debonding process may be performed using plasma debonding.

[0090] Optionally, in this embodiment, the contour shape of the etching groove is the same as the contour shape of the cutting groove, so that no step appears between the groove wall of the etching groove and the groove wall of the cutting groove.

[0091] like Figure 8 As shown, in some optional embodiments, the second conductive layer 200 is covered on the first conductive layer 120 and in the first groove 121, and the second conductive layer 200 covered in the first groove 121 forms a second groove 210, including:

[0092] S31: performing metallization treatment on the groove 121 so as to deposit a metal layer on the inner wall of the first groove 121.

[0093] Metallization treatment, also known as chemical plating, deposits a layer of metal (such as copper, silver, nickel, etc.) on the surface of a non-conductive substrate (such as the hole wall after drilling) through a chemical reduction reaction to achieve conductivity and form the basis for subsequent electroplating.

[0094] S32 : performing electroplating on the entire circuit board so that the metal layer and the outer side of the first conductive layer 120 cover the second conductive layer 200 .

[0095] By performing electroplating on the entire circuit board, a second conductive layer 200 can be quickly formed outside the metal layer and the first conductive layer 120 .

[0096] Optionally, during the overall electroplating, electroplating may be performed specifically on the first groove 121, so that the thickness of the second conductive layer 200 formed in the first groove 121 is greater than the thickness of the second conductive layer 200 outside the first groove 121. For example, the electroplating thickness in the first groove 121 may be 40-50 μm, and the electroplating thickness in other locations may be 10-20 μm.

[0097] like Figure 9 As shown, in some optional embodiments, a metal pillar 300 is disposed in the second groove and fixedly connected to the second conductive layer 200 , and the outer side surface of the metal pillar 300 is located in the same plane as the outer side surface of the second conductive layer 120 covering the first conductive layer 120 , including:

[0098] S41: Covering the surface of the second conductive layer 200 with a second dry film, wherein the second dry film is formed with a first avoidance hole, which is larger than the first groove 121 so that the first avoidance hole is exposed to the second groove.

[0099] By covering with dry film, areas that do not require electroplating can be shielded. Furthermore, by setting the first avoidance hole larger than the first groove 121, and the second groove 210 being formed within the first groove 121, the first avoidance hole can completely expose the second groove 120.

[0100] S42: performing a partial electroplating process on the second groove, so that the second groove and the first avoidance hole are filled with metal material to form the metal column 300.

[0101] like Figure 6 As shown, during the electroplating process, the plating solution can directly contact the exposed second groove 210 and the second conductive layer 200. Therefore, the part of the metal column 300 formed by electroplating located outside the first groove 121 is larger than the part located inside the first groove 121, so that the entire second groove 210 can be completely filled with the metal column 300, avoiding the defect of the second groove 210 not being fully filled.

[0102] S43: Remove the second dry film.

[0103] S44: performing a thickness reduction process on the second conductive layer 200 and the metal pillar 300 so that the outer side of the second conductive layer 200 and the outer side of the metal pillar 300 are located in the same plane.

[0104] Since the thickness of the second conductive layer 200 after electroplating may exceed the usage requirements, the second conductive layer 200 and the metal pillar 300 are subjected to a thickness reduction treatment. This can reduce the thickness of the second conductive layer 200 and the height of the metal pillar 300, and at the same time, can make the outer side of the second conductive layer 200 and the outer side of the metal pillar 300 located in the same plane, thereby facilitating subsequent SMT patching.

[0105] Optionally, in this embodiment, the thickness reduction process is a copper reduction process.

[0106] like Figure 10 As shown, in some optional embodiments, the second conductive layer 200 is subjected to a thickness reduction process so that the outer side of the second conductive layer 200 and the outer side of the metal pillar 300 are located in the same plane, including:

[0107] S51: covering the surface of the second conductive layer 200 with a third dry film; forming a second avoidance hole in the third dry film, the second avoidance hole is larger than the first groove 121 and smaller than the first avoidance hole, so that the edge of the metal column 300 is covered with the third dry film.

[0108] Covering with the third dry film can shield the surface of the second conductive layer 200 to avoid reducing the thickness of the second conductive layer 200 in a subsequent thickness reduction process, which would cause the second conductive layer 200 to be too thin to be subsequently polished.

[0109] It should be noted that, in this embodiment, the single-side distance between the notch of the first groove 121 and the second avoidance hole is 5-7 mils. For example, the single-side distance between the notch of the first groove 121 and the second avoidance hole may be 6 mils.

[0110] S52: chemically thickening the metal pillars 300 not covered with the third dry film.

[0111] Chemical thickness reduction is achieved by chemical etching, where the circuit board is immersed in an etching solution, and the excess metal pillars 300 are removed through a chemical reaction between the metal and the etching solution, thereby reducing the thickness of the metal pillars 300 .

[0112] S53: Grinding the chemically thickened second conductive layer 200 and the metal pillar 300 to make the outer side of the second conductive layer 200 and the outer side of the metal pillar 300 located in the same plane.

[0113] The outer side of the second conductive layer 200 and the outer side of the metal pillar 300 are made to be on the same plane by grinding, so as to facilitate subsequent pattern processing and SMT patching.

[0114] Alternatively, the grinding may be ceramic grinding to remove the step.

[0115] It should be noted that the second dry film layer can be removed after grinding.

[0116] In some optional embodiments, the height difference between the outer side surface of the portion of the second conductive layer 200 not covered by the second dry film layer after chemical copper reduction and the outer side surface of the portion of the second conductive layer 200 covered by the second dry film layer is 5-20 μm.

[0117] The height difference is controlled within 5-20 μm to facilitate subsequent grinding. The height difference here can be that the part not covered by the second dry film layer is higher than the part covered by the second dry film layer, or it can be that the part not covered by the second dry film layer is lower than the part covered by the second dry film layer. This application does not make specific restrictions on this.

[0118] like Figure 11 As shown, in some optional embodiments, after performing copper reduction processing on the second conductive layer 200 so that the outer sides of the second conductive layer 200 are located in the same plane, the method further includes:

[0119] S61: Drilling a blind hole 400 at a second preset position on the outer side of the second conductive layer 200 , so that the blind hole 400 exposes the insulating layer 110 .

[0120] The blind vias 400 are used to isolate different signal layers to reduce electromagnetic interference and crosstalk.

[0121] Optionally, the second preset position is spaced apart from the first preset position.

[0122] In some optional implementations, after drilling the blind hole 400, the following steps may be further performed:

[0123] S62: Perform copper plating on the blind hole 400 and then perform electroplating.

[0124] S63 : performing outer layer pattern processing on the outer side surface of the second conductive layer 200 to develop a circuit pattern on the outer side surface of the second conductive layer 200 .

[0125] S64: performing an etching process on the outer side surface of the second conductive layer 200 to etch the circuit pattern on the outer side surface of the second conductive layer 200 into a circuit.

[0126] S65: performing AOI inspection on the outer side surface of the second conductive layer 200 .

[0127] The AOI (Automated Optical Inspection) process uses high-resolution cameras and algorithms to scan the circuit board surface and compare it to standard design data, identifying anomalies in areas such as traces and solder joints to ensure product quality. In this embodiment, the AOI process is used to check whether the copper thickness images at certain trace locations are aligned on a common vertical line. The vertical line here refers to a direction perpendicular to the outer surface of the circuit board.

[0128] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A locally copper-thick circuit board, characterized in that: include: A laminated plate (100), the laminated plate (100) comprising an insulating layer (110) and a first conductive layer (120) covering at least one side of the insulating layer (110), the first conductive layer (120) being provided with at least one first groove (121), the first groove (121) penetrating the first conductive layer (120) and extending into a portion of the insulating layer (110); a second conductive layer (200) covering the first conductive layer (120) and the first groove (121), wherein the second conductive layer (200) covering the first groove (121) forms a second groove (210); A metal column (300) is disposed in the second groove (210), and the metal column (300) is fixedly connected to the second conductive layer (220), and the outer side surface of the metal column (300) and the outer side surface of the second conductive layer (220) covering the first conductive layer (120) are located in the same plane.

2. The locally copper thick circuit board according to claim 1, characterized in that: The insulating layer (110) is covered on both opposite sides with the first conductive layer (120), each of the first conductive layers (120) is provided with the first groove (121), and each of the first conductive layers (120) is covered with the second conductive layer (200), and each of the second grooves (210) constructed by the second conductive layer (200) is provided with the metal column (300).

3. The partially copper thick circuit board according to any one of claims 1-2, characterized in that: The insulating layer (110) comprises a first insulating layer (111), a second insulating layer (112), and a substrate (113), wherein the first insulating layer (111) and the second insulating layer (112) respectively cover opposite sides of the substrate (113).

4. The locally copper thick circuit board according to claim 3, characterized in that: The substrate (113) includes at least one of an inner conductive layer (1131) and an inner insulating layer (1132).

5. A method for manufacturing a locally copper-thick circuit board, characterized in that: The method for producing a partially copper-thick circuit board according to any one of claims 1 to 4 comprises the following steps: Providing a pressing plate (100), the pressing plate (100) comprising an insulating layer (110) and a first conductive layer (120) covering at least one side of the insulating layer (110); At least one first groove (121) is formed on the first conductive layer (120), and the first groove (121) passes through the first conductive layer (120) and extends into a portion of the insulating layer (110); Covering the first conductive layer (120) with a second conductive layer (200) on the first conductive layer (120) and in the first groove (121), and forming a second groove (210) with the second conductive layer (200) covered in the first groove (121); A metal column (300) is provided in the second groove (210), and the metal column (300) is fixedly connected to the first conductive layer (120) and the second conductive layer (200), and the outer side surface of the metal column (300) and the outer side surface of the second conductive layer (220) covering the first conductive layer (120) are located in the same plane.

6. The method for manufacturing a partially copper-thick circuit board according to claim 5, characterized in that: At least one first groove (121) is formed on the first conductive layer (120), and the first groove (121) penetrates the first conductive layer (120) and extends into a portion of the first conductive layer (120), comprising the following steps: Marking a first preset position of the first groove (121) on the outside of the first conductive layer (120) by developing, and attaching a first dry film to the outer side of the first conductive layer (120), with the first dry film exposing the first preset position; Etching the first preset position to form an etching groove, wherein the etching groove exposes the insulating layer (110); Cutting the exposed insulating layer (110) into a cutting groove extending into a portion of the insulating layer by laser cutting, so that the cutting groove and the etching groove together form the first groove (121); The first dry film is removed, and the groove wall of the first groove (121) is subjected to a de-glue treatment.

7. The method for manufacturing a partially copper-thick circuit board according to claim 5, characterized in that: Covering a second conductive layer (200) on the first conductive layer (120) and in the first groove (121), and forming a second groove (210) with the second conductive layer (200) covered in the first groove (121), comprising: Performing a metallization treatment on the groove (121) so as to deposit a metal layer on the inner wall of the first groove (121); The circuit board is subjected to an overall electroplating process so that the metal layer and the first conductive layer (120) are covered with the second conductive layer (200) on the outside.

8. The method for manufacturing a partially copper-thick circuit board according to claim 7, characterized in that: A metal column (300) is arranged in the second groove, and the metal column (300) is fixedly connected to the second conductive layer (200), and the outer side surface of the metal column (300) and the outer side surface of the second conductive layer (220) covering the first conductive layer (120) are located in the same plane, comprising: A second dry film is covered on the surface of the second conductive layer (200), wherein the second dry film is formed with a first avoidance hole, the first avoidance hole being larger than the first groove (121), so that the first avoidance hole is exposed from the second groove (210); Performing a local electroplating treatment on the second groove (210) so that the second groove (210) and the first avoidance hole are both filled with metal material to form a metal column (300); removing the second dry film; The second conductive layer (200) and the metal column (300) are subjected to a thickness reduction process so that the outer side of the second conductive layer (200) and the outer side of the metal column (300) are located in the same plane.

9. The method for manufacturing a partially copper-thick circuit board according to claim 8, characterized in that: The thickness reduction process of the second conductive layer (200) so that the outer side of the second conductive layer (200) and the outer side of the metal pillar (300) are located in the same plane comprises: A third dry film is covered on the surface of the second conductive layer (200); the third dry film is formed with a second avoidance hole, the second avoidance hole being larger than the first groove (121) and smaller than the first avoidance hole, so that the edge of the metal column (300) covers the third dry film; Chemically thickening the metal pillar (300) not covered with the third dry film; The chemically thickened second conductive layer (200) and the metal pillar (300) are ground flat so that the outer side of the second conductive layer (200) and the outer side of the metal pillar (300) are located in the same plane.

10. The method for manufacturing a partially copper-thick circuit board according to claim 9, characterized in that: The height difference between the outer side surface of the second conductive layer (200) portion not covered by the third dry film layer after chemical thickening and the outer side surface of the second conductive layer (200) portion covered by the third dry film layer is 5-20 μm.

Images