Printed circuit board and electronic device

Abstract

The utility model relates to the technical field of electronic components, in particular to a printed circuit board and an electronic device. The printed circuit board provided by the utility model comprises a first core board, a bonding layer and a second core board which are sequentially stacked in the thickness direction of the printed circuit board, and one surface, facing the bonding layer, of the second core board is provided with a plurality of conductive discs which are arranged at intervals; the first core board is provided with a first filling hole extending along the thickness direction of the conductive disc, the second core board is provided with a second filling hole extending along the thickness direction of the printed circuit board, and the first filling hole and the second filling hole are opposite and are separated by the conductive disc; and the first filling hole and the second filling hole are filled with the conductive filling layer. According to the printed circuit board provided by the invention, when the conductive filling layer is filled, the quality problems of sinking, cavities or core wrapping and the like can be avoided, and the filling effect is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electronic components, and particularly to a printed circuit board and an electronic device. Background Art

[0002] A printed circuit board (PCB), also known as a printed wiring board, is a provider of electrical connections for electronic components and is widely used in various electronic devices. The application of printed circuit boards simplifies the assembly and soldering work of electronic devices and reduces the wiring workload in the traditional way.

[0003] In the prior art, through holes are usually drilled in a printed circuit board, and then a conductive material (such as copper) is filled in the through holes to meet the heat dissipation requirements while ensuring the reliability of the printed circuit board.

[0004] However, when the aspect ratio of the through holes in the printed circuit board (the aspect ratio is the ratio of the thickness of the printed circuit board to the diameter of the through hole) is too high, quality problems such as depression, voids, or core wrapping will occur when filling the through holes. Summary of the Utility Model

[0005] The present application provides a printed circuit board and an electronic device to solve the problem that depression, voids, or core wrapping are likely to occur when filling the through holes of the printed circuit board at present.

[0006] To achieve the above object, the technical solution of the present application is as follows:

[0007] On the one hand, the present application provides a printed circuit board, including a first core board, an adhesive layer, and a second core board that are sequentially stacked along the thickness direction of the printed circuit board. The second core board has a plurality of conductive pads arranged at intervals on the surface facing the adhesive layer; the first core board is provided with a first filling hole extending along the thickness direction of the conductive pads, and the second core board is provided with a second filling hole extending along the thickness direction of the printed circuit board. The first filling hole and the second filling hole are opposite and separated by the conductive pads; a conductive filling layer, and the conductive filling layer fills the first filling hole and the second filling hole respectively.

[0008] In a possible implementation manner, for the printed circuit board provided by the present application, the first filling hole and the second filling hole have a first end facing the conductive pads and a second end away from the conductive pads. In the direction from the first end of the first filling hole towards the second end, the diameter of the first filling hole gradually increases; in the direction from the first end of the second filling hole towards the second end, the diameter of the second filling hole gradually increases.

[0009] In a possible implementation manner, for the printed circuit board provided by the present application, the diameter of the conductive pads is greater than the diameter of the second end of the first filling hole, and / or the diameter of the conductive pads is greater than the diameter of the second end of the second filling hole.

[0010] In a possible implementation, for the printed circuit board provided by the present application, the diameter of the second end of the first filling hole is 0.1 mm - 0.25 mm, and the thickness-to-diameter ratio of the first filling hole is: 2 ≤ H / D1 ≤ 4, where H is the sum of the thicknesses of the first core board, the bonding layer, and the second core board, and D1 is the diameter of the second end of the first filling hole; and / or, the diameter of the second end of the second filling hole is 0.1 mm - 0.25 mm, and the thickness-to-diameter ratio of the second filling hole is: 2 ≤ H / D2 ≤ 4, where D2 is the diameter of the second end of the second filling hole.

[0011] In a possible implementation, for the printed circuit board provided by the present application, the minimum distance between any two adjacent first filling holes is 0.35 mm; and / or, the minimum distance between any two adjacent second filling holes is 0.35 mm.

[0012] In a possible implementation, for the printed circuit board provided by the present application, a first conductive layer is provided on the side of the first core board facing away from the bonding layer; a second conductive layer is provided on the side of the second core board facing away from the bonding layer.

[0013] In a possible implementation, for the printed circuit board provided by the present application, a first plating layer is further provided on the side of the first conductive layer facing away from the conductive pad, and a second plating layer is further provided on the side of the second conductive layer facing away from the conductive pad.

[0014] In a possible implementation, for the printed circuit board provided by the present application, a positioning member is provided on the side of the second core board facing the bonding layer, and the positioning member is located at the edge of the second core board.

[0015] In a possible implementation, for the printed circuit board provided by the present application, the conductive pad is a copper pad.

[0016] On the other hand, the present application provides an electronic device including the above-mentioned printed circuit board.

[0017] For the printed circuit board and the electronic device provided by the present application, the printed circuit board includes a first core board, a second core board, and a bonding layer for bonding the first core board and the second core board. A plurality of conductive pads are provided at intervals on the side of the second core board facing the bonding layer. Then, first filling holes and second filling holes are respectively formed on the first core board and the second core board. The first filling holes, the conductive pads, and the second filling holes correspond one by one. Then, the first filling holes and the second filling holes are respectively filled with a conductive filling layer. The conductive filling layer extends to both sides of the conductive pad through the first filling hole and the second filling hole respectively to form a conductive column penetrating both sides of the printed circuit board with the conductive pad. In this way, when filling the conductive filling layer, quality problems such as depression, cavity, or core inclusion can be avoided, and the filling effect can be improved. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0019] Figure 1 Schematic diagram of the processing of the printed circuit board provided by the embodiment of the present application Figure I ;

[0020] Figure 2 Schematic diagram of the processing of the printed circuit board provided by the embodiment of the present application Figure II ;

[0021] Figure 3 Schematic diagram of the processing of the printed circuit board provided by the embodiment of the present application Figure III ;

[0022] Figure 4 Schematic diagram of the processing of the printed circuit board provided by the embodiment of the present application Figure IV ;

[0023] Figure 5 Schematic diagram of the finished structure of the printed circuit board provided by the embodiment of the present application.

[0024] Explanation of reference numerals:

[0025] 10 - Printed circuit board;

[0026] 100 - First core board;

[0027] 110 - First filling hole; 111 - First end; 112 - Second end;

[0028] 120 - First conductive layer;

[0029] 130 - First plating layer;

[0030] 200 - Adhesive layer;

[0031] 300 - Second core board;

[0032] 310 - Conductive pad;

[0033] 320 - Second filling hole;

[0034] 330 - Second conductive layer;

[0035] 340 - Second plating layer;

[0036] 350 - Positioning member;

[0037] 400 - Conductive filling layer.

[0038] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and more detailed descriptions will be provided hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Description of Specific Embodiments

[0039] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the preferred embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0040] It should be noted that in the description of the embodiments of the present application, the terms indicating the orientation or positional relationship such as "upper", "lower", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description, rather than indicating or implying that the device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present application.

[0041] In addition, it should also be noted that the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0042] In the present application, unless otherwise clearly defined and limited, terms such as "installation", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0043] A printed circuit board (PCB), also known as a printed wiring board, is a provider of electrical connections for electronic components and is widely used in various electronic devices. The application of printed circuit boards simplifies the assembly and soldering work of electronic devices and reduces the wiring workload in the traditional method.

[0044] In the prior art, through holes are usually drilled in a printed circuit board, and then a conductive material (such as copper) is filled in the through holes to meet the heat dissipation requirements while ensuring the reliability of the printed circuit board. However, when the aspect ratio of the through holes in the printed circuit board (the aspect ratio is the ratio of the thickness of the printed circuit board to the diameter of the through hole) is too high (the current filling process can fill an aspect ratio less than 2), quality problems such as depressions, voids, or core-inclusions may occur when filling the through holes.

[0045] In view of this, the printed circuit board and electronic device provided in the present application, the printed circuit board includes a first core board, a second core board, and an adhesive layer for bonding the first core board and the second core board. On the side of the second core board facing the adhesive layer, there are a plurality of conductive pads arranged at intervals. Then, a first filling hole and a second filling hole are respectively opened on the first core board and the second core board. The first filling hole, the conductive pad, and the second filling hole correspond one by one. Then, the first filling hole and the second filling hole are respectively filled with a conductive filling layer. The conductive filling layer extends to both sides of the conductive pad through the first filling hole and the second filling hole respectively to form a conductive column penetrating both sides of the printed circuit board with the conductive pad. With such a setting, when filling the conductive filling layer, quality problems such as depressions, voids, or core-inclusions can be avoided, and the filling effect can be improved.

[0046] The present application will be described in detail below with reference to the drawings and specific embodiments.

[0047] See Figures 1 to 5 , the present application provides a printed circuit board 10, including a first core board 100, an adhesive layer 200, and a second core board 300 stacked in sequence along the thickness direction of the printed circuit board 10. On the side of the second core board 300 facing the adhesive layer 200, there are a plurality of conductive pads 310 arranged at intervals; the first core board 100 is provided with a first filling hole 110 extending along the thickness direction of the conductive pad 310, the second core board 300 is provided with a second filling hole 320 extending along the thickness direction of the printed circuit board 10, and the first filling hole 110 and the second filling hole 320 are opposite and separated by the conductive pad 310; a conductive filling layer 400, and the conductive filling layer 400 fills the first filling hole 110 and the second filling hole 320 respectively.

[0048] In the present application, through the first core board 100, the adhesive layer 200, and the second core board 300 stacked in sequence along the thickness direction, the high integration of the printed circuit board 10 is realized, which is beneficial to improving the overall integration and design flexibility of electronic products.

[0049] In specific implementation, the total thickness of the first core board 100 and the bonding layer 200 is equal to the thickness of the second core board 300. For example, the thickness of the second core board 300 is 50 - 75 μm greater than the thickness of the first core board 100, and the thickness of the bonding layer 200 is 50 - 75 μm. In this way, when the first filling holes 110 and the second filling holes 320 are opened subsequently, the thicknesses of the first filling holes 110 and the second filling holes 320 can be made substantially the same, so that when the conductive filling layer 400 is filled, the same filling quality can be achieved.

[0050] It should be noted that on the side of the second core board 300 facing the bonding layer 200, each conductive pad 310 is reserved through pattern transfer and etching, providing a reliable transmission path for circuit signals and enhancing the electrical interconnection ability inside the printed circuit board 10. With appropriate positions and spacings of the conductive pads 310, the stability and efficiency of signal transmission are ensured, which helps to reduce signal interference and attenuation.

[0051] Specifically, the second core board 300 is first subjected to brownification treatment, and then laminated and pressed together with the bonding layer 200 and the first core board 100 to form the printed circuit board 10. Among them, the bonding layer 200 can be a prepreg, and the prepreg is usually composed of resin and reinforcing materials. Under heating and pressure, the prepreg softens and bonds the first core board 100 and the second core board 300, and reacts and cures after cooling to form a stable multi-layer structure.

[0052] Furthermore, laser drilling is performed on both sides of the printed circuit board 10 (that is, laser drilling is respectively performed from the side of the first core board 100 facing away from the bonding layer 200 and the side of the second core board 300 facing away from the bonding layer 200). Thus, the first filling holes 110 and the second filling holes 320 are formed, and then the first filling holes 110 and the second filling holes 320 are cleaned. By opening the first filling holes 110 and the second filling holes 320, it is beneficial to conduct the heat accumulated on the printed circuit board 10, increase the heat dissipation path and heat dissipation area of the heat on the printed circuit board 10, and thus effectively improve the overall heat conduction and heat dissipation performance of the printed circuit board 10.

[0053] Further, after cleaning the first filling hole 110 and the second filling hole 320, the printed circuit board 10 is subjected to electroless copper plating and flash plating, and then the first filling hole 110 and the second filling hole 320 are filled with the conductive filling layer 400. The conductive filling layer 400 extends to both sides of the conductive pad 310 through the first filling hole 110 and the second filling hole 320 respectively, so as to form a conductive column penetrating both sides of the printed circuit board 10 with the conductive pad 310. In this way, the electrical connection and signal transmission capabilities inside the printed circuit board 10 are enhanced. In addition, by filling the conductive filling layer 400, during the use of the printed circuit board 10, the conductive filling layer 400 can serve as part of the heat conduction path to help disperse and export the heat generated inside the printed circuit board 10, thereby improving the heat dissipation efficiency and stability of the printed circuit board 10.

[0054] Wherein, the purpose of setting the conductive pad 310 is to form a "bridge" between the first filling hole 110 and the second filling hole 320, that is, to facilitate the filling of the conductive filling layer 400, so as to form a conductive column penetrating both sides of the printed circuit board 10 with the conductive filling layer 400.

[0055] On one side of the second core board 300 facing the bonding layer 200, a plurality of conductive pads 310 are arranged at intervals. Then, the first core board 100 and the second core board 300 are bonded through the bonding layer 200. The first filling hole 110 and the second filling hole 320 are respectively opened on the first core board 100 and the second core board 300, and then the first filling hole 110 and the second filling hole 320 are respectively filled with the conductive filling layer 400. The conductive filling layer 400 extends to both sides of the conductive pad 310 through the first filling hole 110 and the second filling hole 320 respectively, so as to form a conductive column penetrating both sides of the printed circuit board 10 with the conductive pad 310. In this way, compared with directly opening a through hole penetrating the printed circuit board on one side of the printed circuit board and filling it with a conductive material in the related art, the printed circuit board 10 provided in the present application respectively opens the first filling hole 110 and the second filling hole 320 from both sides, and then fills the conductive filling layer 400 in the first filling hole 110 and the second filling hole 320 respectively, which can avoid quality problems such as depressions, voids or core-centeredness, and improve the filling effect.

[0056] See Figure 4 and Figure 5 In the embodiment of the present application, the first filling hole 110 and the second filling hole 320 have a first end 111 facing the conductive pad 310 and a second end 112 away from the conductive pad 310. In the direction from the first end 111 to the second end 112 of the first filling hole 110, the aperture of the first filling hole 110 gradually increases; in the direction from the first end 111 to the second end 112 of the second filling hole 320, the aperture of the second filling hole 320 gradually increases.

[0057] It can be understood that when the first filling hole 110 and the second filling hole 320 are laser-drilled, both the first filling hole 110 and the second filling hole 320 extend from the end close to the conductive disk 310 to the far end, and the aperture gradually increases to form a tapered hole. In this way, it can guide the flow of the conductive filling layer 400 towards the conductive disk 310, promote the uniformity and efficiency during the filling process, avoid problems such as incomplete filling or voids, and thus improve the manufacturing quality and yield of the printed circuit board 10.

[0058] See Figure 4 , in the embodiment of the present application, the diameter of the conductive disk 310 is greater than the diameter of the second end 112 of the first filling hole 110, and / or the diameter of the conductive disk 310 is greater than the diameter of the second end 112 of the second filling hole 320.

[0059] It should be noted that increasing the diameter of the conductive disk 310 can ensure a significant increase in the contact area between it and the edges of the first filling hole 110 and the second filling hole 320. In this way, it helps to reduce the contact resistance, improve the current transmission efficiency, and can also effectively disperse the current density, reducing the risk of performance degradation or damage to the printed circuit board 10 caused by local overheating, thereby enhancing the stability and reliability of the printed circuit board 10.

[0060] Specifically, when laser drilling (drilling the first filling hole 110 and the second filling hole 320), there is a certain deviation in laser alignment (the deviation is less than 25 μm). Therefore, the diameter of the conductive disk 310 can be set to be 50 μm larger than the diameter of the second end 112 to ensure that both the first filling hole 110 and the second filling hole 320 can extend to the conductive disk 310.

[0061] See Figure 3 and Figure 4 , in the embodiment of the present application, the diameter of the second end 112 of the first filling hole 110 is 0.1 mm - 0.25 mm, and the thickness-diameter ratio of the first filling hole 110 is: 2 ≤ H / D1 ≤ 4, where H is the sum of the thicknesses of the first core board 100, the bonding layer 200, and the second core board 300, and D1 is the diameter of the second end 112 of the first filling hole 110; and / or the diameter of the second end 112 of the second filling hole 320 is 0.1 mm - 0.25 mm, and the thickness-diameter ratio of the second filling hole 320 is: 2 ≤ H / D2 ≤ 4, where D2 is the diameter of the second end 112 of the second filling hole 320.

[0062] Exemplarily, by respectively forming a first filling hole 110 and a second filling hole 320 on two sides of the printed circuit board 10, and both the first filling hole 110 and the second filling hole 320 extend to the conductive pad 310, the aspect ratio of the first filling hole 110 and the second filling hole 320 is smaller than that of the through hole on the printed circuit board 10 with the same thickness. In this way, when electroplating and filling the printed circuit board with the same thickness, filling the first filling hole 110 and the second filling hole 320 respectively is easier than filling the through hole. And within the range where the diameter of the second end 112 is 0.1 mm - 0.25 mm, the aspect ratio of the first filling hole 110 and the second filling hole 320 is within the range of 2 - 4 to fill the conductive filling layer 400, which can avoid quality problems such as depression, cavity or core-centeredness. Compared with the related art, when the aspect ratio of the through hole is too large (for example, greater than 2), quality problems such as depression, cavity or core-centeredness are likely to occur when filling the conductive material. The printed circuit board 10 provided in this application can effectively improve the filling effect.

[0063] In the embodiment of this application, the minimum distance between any two adjacent first filling holes 110 is 0.35 mm; and / or, the minimum distance between any two adjacent second filling holes 320 is 0.35 mm.

[0064] It should be noted that in the related art, when directly drilling each through hole on one side of the printed circuit board, the distance between adjacent two holes is usually greater than 0.5 mm. When the distance is less than 0.5 mm, as the distance becomes smaller, the difficulty of filling the conductive material increases significantly, and quality problems such as cavity, depression or light transmission are likely to occur. In the embodiment of this application, by respectively forming the first filling hole 110 and the second filling hole 320 on the first core board 100 and the second core board 300, and then respectively filling the conductive filling layer 400 in the first filling hole 110 and the second filling hole 320, filling processing with a minimum distance (the minimum distance between any two adjacent first filling holes 110, and / or, the minimum distance between any two adjacent second filling holes 320) of 0.35 mm can be realized, and quality problems such as cavity, depression or light transmission can be avoided.

[0065] See Figure 5 , in the embodiment of this application, one side of the first core board 100 away from the bonding layer 200 has a first conductive layer 120; one side of the second core board 300 away from the bonding layer 200 has a second conductive layer 330.

[0066] Wherein, the setting of the first conductive layer 120 and the second conductive layer 330 provides a necessary electrical connection path for the printed circuit board 10. The first conductive layer 120 and the second conductive layer 330 can effectively transmit signals to ensure the normal use of the printed circuit board 10.

[0067] Furthermore, the presence of the first conductive layer 120 and the second conductive layer 330 helps to reduce signal attenuation and distortion during transmission, ensuring high integrity and accuracy of the signal during transmission.

[0068] See Figure 5 , in the embodiment of the present application, a first plating layer 130 is further provided on the side of the first conductive layer 120 facing away from the conductive disk 310, and a second plating layer 340 is further provided on the side of the second conductive layer 330 facing away from the conductive disk 310.

[0069] It can be understood that after electroplating and filling the first filling hole 110 and the second filling hole 320, the first filling hole 110 and the second filling hole 320 are filled with the conductive filling layer 400, and at the same time, the first plating layer 130 and the second plating layer 340 are respectively formed on the surfaces of the first conductive layer 120 and the second conductive layer 330.

[0070] Among them, in the related art, when electroplating and filling a through-hole, a relatively thick plating layer (plating layer thickness greater than 80 μm) will be formed on the surface of the printed circuit board. Thus, it is necessary to thin the plating layer, which is likely to result in poor uniformity of the plating layer thickness, affecting the quality of the printed circuit board, and at the same time increasing the manufacturing cost. In the embodiment of the present application, by electroplating and filling the first filling hole 110 and the second filling hole 320 respectively, the first plating layer 130 and the second plating layer 340 are relatively thin (thickness less than 50 μm). Thus, it is not necessary to thin the first plating layer 130 and the second plating layer 340.

[0071] See Figure 5 , in the embodiment of the present application, a positioning member 350 is provided on the side of the second core board 300 facing the bonding layer 200, and the positioning member 350 is located at the edge of the second core board 300.

[0072] It can be understood that the side of the second core board 300 facing the bonding layer 200 is subjected to pattern transfer and etching to retain each conductive disk 310, and at the same time, the positioning member 350 is retained at the edge of the second core board 300. The positioning member 350 can play a clear positioning and guiding role when opening the first filling hole 110 and the second filling hole 320, realizing precise alignment between the first filling hole 110, the conductive disk 310, and the second filling hole 320, and reducing the risk of performance degradation or damage caused by misalignment.

[0073] In addition, the positioning member 350 at the edge position optimizes the production process and improves production efficiency. That is to say, the positioning member 350 can be used as an identification point for laser drilling, improving the drilling efficiency of laser drilling.

[0074] In the embodiment of the present application, the conductive disk 310 is a copper disk.

[0075] It should be noted that copper has good electrical conductivity, which can ensure that current is transmitted quickly and stably in the conductive disk 310 , reduce energy loss and signal attenuation, and help improve the overall performance of the printed circuit board 10 .

[0076] Furthermore, copper has good thermal conductivity. During the operation of the printed circuit board 10, a certain amount of heat will be generated due to the passage of current and the heating of components. As a material with excellent thermal conductivity, copper can effectively disperse and conduct this heat to other parts of the printed circuit board 10 or the external environment, thereby reducing the risk of performance degradation or damage caused by excessive local temperature.

[0077] Correspondingly, the conductive filling layer 400 may also be made of copper to form a copper column penetrating the printed circuit board 10 with the conductive plate 310 , thereby ensuring the reliability of the printed circuit board 10 and meeting the heat dissipation requirements.

[0078] The embodiment of the present application also provides a method for processing a printed circuit board 10, which specifically includes the following steps:

[0079] S101 : Arrange a first core plate 100 and a second core plate 300 .

[0080] Among them, see Figure 1 According to the required thickness of the printed circuit board 10 , the first core board 100 and the second core board 300 are used with appropriate thicknesses, and the thickness of the second core board 300 is 50-75 μm greater than that of the first core board 100 .

[0081] S102: Pattern transfer of the first core board 100 and the second core board 300.

[0082] Specifically, see Figure 2 , the first core board 100 and the second core board 300 may both include a conductive layer and an internal resin layer, and then the first core board 100 is pattern-transferred, and the conductive layer on the side of the first core board 100 facing the second core board 300 is etched away, and the conductive layer (that is, the first conductive layer 120) on the side of the first core board 100 facing away from the second core board 300 is retained. The second core board 300 is pattern-transferred, and each conductive plate 310 and each positioning member 350 are etched on the side of the second core board 300 facing the first core board 100, and the conductive layer (that is, the second conductive layer 330) on the side of the second core board 300 facing away from the first core board 100 is retained.

[0083] S103 : Pressing the first core plate 100 , the adhesive layer 200 and the second core plate 300 .

[0084] Specifically, see Figure 3, before lamination, the second core board 300 is subjected to brownification treatment. The brownification treatment is carried out by micro-etching the conductive layer and forming a uniform organic-metal coating on its surface, thereby increasing the bonding force between the conductive layer and the resin layer and improving the performance of the printed circuit board 10. Then, the first core board 100, the bonding layer 200, and the second core board 300 are laminated and pressed in sequence.

[0085] S104: Laser drilling.

[0086] Specifically, refer to Figure 4 , first align the positioning members 350 on the second core board 300, and then laser drill each first filling hole 110 along the direction of the first core board 100 towards the conductive disk 310, and laser drill each second filling hole 320 along the direction of the second core board 300 towards the conductive disk 310. Both the first filling hole 110 and the second filling hole 320 extend to the conductive disk 310, and then clean each first filling hole 110 and each second filling hole 320.

[0087] S105: Electroplating hole filling.

[0088] Specifically, refer to Figure 5 , after the cleaning treatment, it is also necessary to carry out electroless copper plating and flash plating, and then electroplate hole filling. A conductive filling layer 400 (the conductive filling layer 400 can be a copper layer) is filled in both the first filling hole 110 and the second filling hole 320. The conductive filling layer 400 is connected to the conductive disk 310 (the conductive disk 310 can be a copper disk). In addition, a first plating layer 130 and a second plating layer 340 (the first plating layer 130 and the second plating layer 340 can be copper layers) are respectively formed on the surfaces of the first conductive layer 120 and the second conductive layer 330. In this way, the printed circuit board 10 is formed. At the same time, the conductive filling layer 400 and the connected conductive disk 310 form a conductive column (the conductive column can be an electroplated copper column) penetrating the printed circuit board 10 to meet the heat dissipation requirements of the printed circuit board 10.

[0089] In addition, filling the first filling hole 110 and the second filling hole 320 in this way takes much less time than filling through holes in the related art, improving the production efficiency.

[0090] Based on the above embodiments, the embodiment of the present application further provides an electronic device, including the printed circuit board 10 provided in any of the above embodiments.

[0091] Among them, the printed circuit board 10 has been described in detail in the above embodiments and will not be elaborated here.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A printed circuit board, characterized in that, It comprises a first core board, an adhesive layer and a second core board which are sequentially stacked along the thickness direction of the printed circuit board, wherein the second core board has a plurality of conductive plates arranged at intervals on one side facing the adhesive layer; The first core plate is provided with a first filling hole extending in the thickness direction of the conductive plate, and the second core plate is provided with a second filling hole extending in the thickness direction of the printed circuit board, the first filling hole and the second filling hole are opposite to each other and separated by the conductive plate; A conductive filling layer is provided, wherein the conductive filling layer fills the first filling hole and the second filling hole respectively.

2. The printed circuit board according to claim 1, wherein The first filling hole and the second filling hole have a first end facing the conductive plate and a second end away from the conductive plate, In a direction from the first end of the first filling hole toward the second end, the aperture of the first filling hole gradually increases; In a direction from the first end toward the second end of the second filling hole, a hole diameter of the second filling hole gradually increases.

3. The printed circuit board according to claim 2, wherein The diameter of the conductive plate is greater than the diameter of the second end of the first filling hole, and / or the diameter of the conductive plate is greater than the diameter of the second end of the second filling hole.

4. The printed circuit board according to claim 2, wherein The diameter of the second end of the first filling hole is 0.1 mm-0.25 mm, and the thickness-to-diameter ratio of the first filling hole is: 2≤H / D1≤4, H is the sum of the thicknesses of the first core plate, the bonding layer and the second core plate, and D1 is the diameter of the second end of the first filling hole; and / or, The diameter of the second end of the second filling hole is 0.1 mm-0.25 mm, and the thickness-to-diameter ratio of the second filling hole is: 2≤H / D2≤4, wherein D2 is the diameter of the second end of the second filling hole.

5. The printed circuit board according to claim 1, wherein The minimum spacing between any two adjacent first filling holes is 0.35 mm; and / or the minimum spacing between any two adjacent second filling holes is 0.35 mm.

6. The printed circuit board according to claim 1, wherein The first core board has a first conductive layer on a side facing away from the bonding layer; The second core board has a second conductive layer on a side facing away from the bonding layer.

7. The printed circuit board according to claim 6, characterized in that, A first plating layer is further provided on a side of the first conductive layer facing away from the conductive disk, and a second plating layer is further provided on a side of the second conductive layer facing away from the conductive disk.

8. The printed circuit board according to claim 1, wherein A positioning piece is provided on the side of the second core plate facing the bonding layer, and the positioning piece is located at the edge of the second core plate.

9. The printed circuit board according to any one of claims 1-8, characterized in that, The conductive disk is a copper disk.

10. An electronic device, characterized in that, Comprising a printed circuit board as claimed in any one of claims 1 to 9.

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