Multilayer circuit board

Abstract

The utility model provides a multilayer circuit board comprising a circuit board assembly, the circuit board assembly is provided with a first hole and a second hole which are communicated with each other, and the second hole is close to the end face of the circuit board assembly relative to the first hole; the first metal layer covers the hole wall of the first hole; the dielectric layer covers one side, far away from the hole wall of the first hole, of the first metal layer; the second metal layer covers the side, away from the hole wall of the first hole, of the dielectric layer and covers the hole wall of the second hole, and the first metal layer, the second metal layer and the dielectric layer jointly form a capacitor structure. Only the end face of the second metal layer of the capacitor structure is exposed on the surface of the multi-layer circuit board, the area of the surface of the multi-layer circuit board occupied by the capacitor structure is small, the capacitor structure with large capacity can be formed, light weight and miniaturization of the multi-layer circuit board can be achieved, the performance of the multi-layer circuit board with the capacitor structure is further improved, and the manufacturing cost of the multi-layer circuit board is reduced. And the integration level of the multi-layer circuit board is further improved.

Description

Technical Field

[0001] The present application relates to the technical field of circuit boards, and in particular to a multi-layer circuit board. Background Art

[0002] As today's electronic products are developing towards being shorter, lighter and thinner, the density requirements for PCB, the motherboard of components, are becoming higher and higher. Passive component embedding technology can greatly reduce the number of components while also improving electromagnetic performance.

[0003] In the related technology, embedded capacitor technology, which embeds capacitor elements inside the substrate, is an important solution for miniaturization of electronic systems. It is usually used in microphones and wearable electronic products to play the role of filtering, timing, decoupling and electrical energy storage. Its main advantage is that it can improve the stability and reliability of electronic systems, reduce product costs and reduce the physical size of products.

[0004] However, in the above-mentioned multi-layer circuit board with embedded capacitors, the area of ​​the capacitors exposed outside the multi-layer circuit board is relatively large, and the area used for achieving electrical connection is relatively small, which will affect the performance of the multi-layer circuit board. Utility Model Content

[0005] In order to solve at least one of the problems mentioned in the background technology, the present application provides a multi-layer circuit board, aiming to solve the technical problem in the related technology that a multi-layer circuit board with embedded capacitors has a large area of ​​capacitors exposed to the outside of the multi-layer circuit board and a small area for achieving electrical connection, which affects the performance of the multi-layer circuit board.

[0006] In order to achieve the above object, the present application provides a multi-layer circuit board, comprising:

[0007] A circuit board assembly, the circuit board assembly having a first hole and a second hole connected to each other, the second hole being closer to an end surface of the circuit board assembly relative to the first hole;

[0008] A first metal layer covering the hole wall of the first hole;

[0009] a dielectric layer covering a side of the first metal layer away from a hole wall of the first hole;

[0010] The second metal layer covers the side of the dielectric layer away from the hole wall of the first hole and covers the hole wall of the second hole. The first metal layer, the second metal layer and the dielectric layer together form a capacitor structure.

[0011] In the above-mentioned multi-layer circuit board, optionally, the first hole and the second hole are coaxially arranged, and the aperture of the first hole is larger than the aperture of the second hole.

[0012] In the above-mentioned multi-layer circuit board, optionally, it further includes a third metal layer located on opposite sides of the circuit board assembly, the third metal layer is spaced apart from the dielectric layer, and an extension direction of the third metal layer intersects with an extension direction of the second metal layer;

[0013] The second metal layer is connected to the third metal layer.

[0014] In the above-mentioned multi-layer circuit board, optionally, the number of the capacitor structures is multiple;

[0015] Along the surface extension direction of the third metal layer, the plurality of capacitor structures are arranged at intervals, and adjacent capacitor structures are connected through the third metal layer.

[0016] In the above-mentioned multi-layer circuit board, optionally, the number of the capacitor structures is multiple;

[0017] Along the thickness direction of the circuit board assembly, the plurality of capacitor structures are arranged at intervals, and adjacent capacitor structures are connected via the third metal layer.

[0018] In the above-mentioned multi-layer circuit board, optionally, the circuit board assembly includes a plurality of the dielectric layers and a plurality of the first metal layers, and the plurality of the dielectric layers are sequentially spaced apart by a plurality of the first metal layers.

[0019] In the above-mentioned multi-layer circuit board, optionally, the circuit board assembly includes a first substrate, a fourth metal layer, a second substrate and a third metal layer stacked in sequence along the thickness direction, the second substrate is located on the side of the fourth metal layer away from the first substrate, and the third metal layer is located on the side of the second substrate away from the second metal layer.

[0020] In the above-mentioned multi-layer circuit board, optionally, the first metal layer is connected to the fourth metal layer.

[0021] In the above-mentioned multi-layer circuit board, optionally, the first substrate includes a substrate body, a circuit pattern located outside the substrate body, and a prepreg.

[0022] The prepreg fills the circuit pattern.

[0023] In the above-mentioned multi-layer circuit board, optionally, the second substrate is a prepreg.

[0024] The multilayer circuit board provided by the present application includes: a circuit board assembly, the circuit board assembly has a first hole and a second hole connected to each other, the second hole is closer to the end face of the circuit board assembly relative to the first hole; a first metal layer, covering the hole wall of the first hole; a dielectric layer, covering the side of the first metal layer away from the hole wall of the first hole; a second metal layer, covering the side of the dielectric layer away from the hole wall of the first hole, and covering the hole wall of the second hole, the first metal layer, the second metal layer and the dielectric layer together form a capacitor structure. Only the end face of the second metal layer of the capacitor structure is exposed on the surface of the multilayer circuit board, the capacitor structure occupies a small surface area of ​​the multilayer circuit board, and can form a capacitor structure with a larger capacity, which is conducive to realizing the lightness and miniaturization of the multilayer circuit board, thereby improving the performance of the multilayer circuit board with the capacitor structure, and thereby improving the integration of the multilayer circuit board.

[0025] The structure of the present application and its other application objects and beneficial effects will be more clearly understood through the description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic diagram of a first cross-sectional structure of a multilayer circuit board provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of a partial three-dimensional structure of a multi-layer circuit board provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of a partial cross-sectional structure of a multi-layer circuit board provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of a second cross-sectional structure of a multi-layer circuit board provided in an embodiment of the present application.

[0031] Description of reference numerals:

[0032] 10-Multilayer circuit board; 11-Capacitor structure;

[0033] 100-circuit board assembly; 101-first hole; 102-second hole;

[0034] 110-first substrate; 111-substrate body; 112-prepreg sheet;

[0035] 120-a fourth metal layer; 130-a second substrate;

[0036] 200-first metal layer;

[0037] 300- dielectric layer;

[0038] 400- second metal layer;

[0039] 500 - the third metal layer.

[0040] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope 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

[0041] In the related art, chip capacitors are usually used on the surface of PCB boards. The chip capacitors need to occupy a large area on the PCB, which is not conducive to the miniaturization of the PCB board. In addition, this capacitor structure has a large surface area on the multi-layer circuit board, and the capacity of the capacitor structure is small. The performance of the multi-layer circuit board cannot meet user needs.

[0042] The embodiment of the present application provides a multilayer circuit board, including: a circuit board assembly, the circuit board assembly has a first hole and a second hole that are interconnected, the second hole is closer to the end face of the circuit board assembly relative to the first hole; a first metal layer, covering the hole wall of the first hole; a dielectric layer, covering the side of the first metal layer away from the hole wall of the first hole; a second metal layer, covering the side of the dielectric layer away from the hole wall of the first hole, and covering the hole wall of the second hole, the first metal layer, the second metal layer and the dielectric layer together form a capacitor structure. The capacitor structure of the multilayer circuit board is a coaxial structure, only one side of the capacitor structure is exposed on the surface of the multilayer circuit board, the capacitor structure occupies a small surface area of ​​the multilayer circuit board, and can form a capacitor structure with a larger capacity, which is conducive to realizing the lightness and miniaturization of the multilayer circuit board, thereby improving the performance of the multilayer circuit board with the capacitor structure, and thereby improving the integration of the multilayer circuit board.

[0043] In order to make the purpose, 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 in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar structural parts or structural parts with the same or similar functions. The described embodiments are part of the structural embodiments of the present application, rather than the embodiments of the full structure. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0044] Reference Figure 1-Figure 4 As shown, an embodiment of the present application provides a multi-layer circuit board 10 , including a circuit board assembly 100 , a first metal layer 200 , a dielectric layer 300 and a second metal layer 400 .

[0045] Specifically, the circuit board assembly 100 has a first hole 101 and a second hole 102 that are connected to each other, and the second hole 102 is closer to the end surface of the circuit board assembly 100 relative to the first hole 101 .

[0046] It can be understood that one first hole 101 may correspond to two second holes 102 , that is, the two second holes 102 are respectively located on opposite sides of the first hole 101 and are connected to the first hole 101 .

[0047] The first metal layer 200 covers the hole wall of the first hole 101 ; the dielectric layer 300 covers the side of the first metal layer 200 away from the hole wall of the first hole 101 .

[0048] It should be noted that the first metal layer 200 can be used for electrical connection. The material of the first metal layer 200 can be any. Exemplarily, the material of the first metal layer 200 can be one or more of copper (Cu), silver (Ag), nickel (Ni), gold (Au) and aluminum (Al). The embodiment of the present application does not limit the specific material of the first metal layer 200, nor is it limited to the above examples.

[0049] It is understandable that the dielectric layer 300 may be an insulating layer in a capacitor, used to store charges and increase capacitance. The dielectric layer 300 may be made of any material.

[0050] Exemplarily, the dielectric layer 300 may be made of one or more of aluminum oxide (Al2O3), zirconium dioxide (ZrO2), polytetrafluoroethylene (PTFE), polyethylene (Polyethylene) and polypropylene (Polypropylene). The present application embodiment does not limit the specific material of the dielectric layer 300, nor is it limited to the above examples.

[0051] It is understandable that the materials of the dielectric layer 300 and the first metal layer 200 can be selected according to actual conditions.

[0052] The second metal layer 400 covers a side of the dielectric layer 300 away from the hole wall of the first hole 101 , and covers the hole wall of the second hole 102 .

[0053] It should be noted that the dielectric layer 300 , the first metal layer 200 and the second metal layer 400 may be arranged sequentially along the surface extension direction of the circuit board assembly 100 , or may be arranged sequentially along the thickness direction of the circuit board assembly 100 .

[0054] In the following, the dielectric layer 300 , the first metal layer 200 and the second metal layer 400 are sequentially arranged along the surface extension direction of the circuit board assembly 100 , that is, the dielectric layer 300 , the first metal layer 200 and the second metal layer 400 all extend along the thickness direction of the circuit board assembly 100 .

[0055] The first metal layer 200 , the second metal layer 400 and the dielectric layer 300 together form a capacitor structure 11 .

[0056] It is understandable that the material of the second metal layer 400 may be the same as or different from the material of the first metal layer 200. The material of the second metal layer 400 may refer to the material of the first metal layer 200, and will not be described in detail here.

[0057] It should be noted that the hole wall of the first hole 101 and the first metal layer 200 are spaced apart by a dielectric layer 300, the second metal layer 400 covers the hole wall of the first hole 101, the second metal layer 400 and the first metal layer 200 are spaced apart by a dielectric layer 300, the first metal layer 200, the second metal layer 400 and the dielectric layer 300 together form a capacitor structure 11, one of the first metal layer 200 and the second metal layer 400 is the positive electrode of the capacitor structure 11, and the other is the negative electrode of the capacitor structure 11.

[0058] The following description will be made by taking the first metal layer 200 as the positive electrode of the capacitor structure 11 and the second metal layer 400 as the negative electrode of the capacitor structure 11 as an example.

[0059] When the capacitor structure 11 is connected to a power source, charges flow from the power source to the first metal layer 200, and the same amount of charges flow out from the second metal layer 400. In this way, an electric field is formed inside the capacitor structure 11, and the charges are stored in the electric field. When the capacitor structure 11 is disconnected from the power source, the charges stored in the capacitor structure 11 begin to flow back to the circuit, releasing the stored energy.

[0060] Through the above-mentioned arrangement, only the end surface of the second metal layer 400 of the capacitor structure 11 is exposed on the surface of the multi-layer circuit board 10. The capacitor structure 11 occupies a smaller surface area of ​​the multi-layer circuit board 10, and a capacitor structure 11 with a larger capacity can be formed, which is beneficial to realizing the lightweight and miniaturization of the multi-layer circuit board 10, thereby improving the performance of the multi-layer circuit board 10 with the capacitor structure 11, and thereby improving the integration of the multi-layer circuit board 10.

[0061] Reference Figure 1-Figure 4 As shown, as an optional embodiment, the first hole 101 and the second hole 102 are coaxially arranged, and the aperture of the first hole 101 is larger than the aperture of the second hole 102. At this time, along the thickness direction of the circuit board assembly 100, the projection of the opening of the second hole 102 on the circuit board assembly 100 can be located at the projection of the opening of the first hole 101 on the circuit board assembly 100, and the first metal layer 200, the second metal layer 400 and the dielectric layer 300 are coaxially arranged, so that the thickness of the dielectric layer 300 is relatively uniform.

[0062] It should be noted that the thickness of the dielectric layer 300 can be adjusted according to actual conditions.

[0063] Through the above-mentioned setting, the capacitor structure 11 is a coaxial structure, and the capacitor structure 11 occupies a smaller surface area of ​​the multi-layer circuit board 10, so that a larger capacity capacitor structure 11 can be formed, which is conducive to realizing the lightweight and miniaturization of the multi-layer circuit board 10, thereby improving the performance of the multi-layer circuit board 10 with the capacitor structure 11.

[0064] Reference Figure 1-Figure 4 As shown, as an optional implementation, the circuit board assembly 100 includes a third metal layer 500 located on two opposite sides of the second metal layer 400. The second metal layer 400 is connected to the third metal layer 500.

[0065] It is understandable that the material of the third metal layer 500 may be the same as or different from the material of the first metal layer 200. The material of the third metal layer 500 may refer to the material of the first metal layer 200, and will not be described in detail here. That is, the materials of the first metal layer 200, the second metal layer 400, and the third metal layer 500 are all the same.

[0066] Specifically, the third metal layer 500 is spaced apart from the dielectric layer 300, and the extension direction of the third metal layer 500 intersects with the extension direction of the second metal layer 400. That is, the third metal layer 500 is located outside the circuit board assembly 100, and the third metal layer 500 is spaced apart from the dielectric layer 300 through a portion of the circuit board assembly 100.

[0067] The two third metal layers 500 can be used to connect the positive electrode and the negative electrode of the power source respectively.

[0068] Through the above arrangement, the stability and reliability of the capacitor structure 11 can be enhanced to improve the performance and integration of the multi-layer circuit board 10, while reducing the manufacturing cost to facilitate the miniaturization and thinning of the multi-layer circuit board.

[0069] Reference Figure 4 As shown, as an optional implementation, there are multiple capacitor structures 11.

[0070] It is understandable that the number of capacitor structures 11 can be two, three, four, five, six, seven, eight, etc. The embodiment of the present application does not limit the specific number of capacitor structures 11, nor is it limited to the above examples.

[0071] The following description is made by taking the case where the number of the capacitor structures 11 is two as an example.

[0072] Reference Figure 4 As shown, in some embodiments, in the surface extension direction of the third metal layer 500 , a plurality of capacitor structures 11 are arranged at intervals, and adjacent capacitor structures 11 are connected through the third metal layer 500 .

[0073] It is understandable that the second metal layer 400 of the capacitor structure 11 is connected to the third metal layer 500. When there are multiple capacitor structures 11, adjacent capacitor structures 11 can be connected through the third metal layer 500 located outside the circuit board assembly 100.

[0074] It should be noted that two adjacent capacitor structures 11 may be connected via two oppositely disposed third metal layers 500 to achieve electrical connection between the two capacitor structures 11 .

[0075] In some embodiments, along the thickness direction of the circuit board assembly 100 , a plurality of capacitor structures 11 are arranged at intervals, and adjacent capacitor structures 11 are connected via the third metal layer 500 .

[0076] It is understandable that the second metal layer 400 of the capacitor structure 11 is connected to the third metal layer 500. When there are multiple capacitor structures 11, adjacent capacitor structures 11 can be connected through the third metal layer 500 located outside the circuit board assembly 100.

[0077] It should be noted that two adjacent capacitor structures 11 may be connected via two oppositely disposed third metal layers 500 to achieve electrical connection between the two capacitor structures 11 .

[0078] By arranging multiple capacitor structures 11 along a specific direction on the surface of the third metal layer 500 and arranging them at intervals, the space can be effectively utilized and the layout between the capacitor structures 11 can be made more compact. Adjacent capacitor structures 11 are connected through the third metal layer 500, which can enhance the structural stability and reliability of the multi-layer circuit board 10, reduce the risk of interference or damage caused by changes in the external environment, and facilitate the realization of electrical connection, so as to improve the performance of the multi-layer circuit board 10.

[0079] When there are multiple capacitor structures 11 , as an optional implementation, the multiple dielectric layers 300 are made of the same or different materials.

[0080] In some embodiments, when the multilayer circuit board 10 includes a plurality of capacitor structures 11 , the materials of the dielectric layers 300 used in different capacitor structures 11 may be the same or different.

[0081] In some embodiments, when the capacitor structure 11 includes multiple dielectric layers 300 , the materials of the dielectric layers 300 at different locations may be the same or different.

[0082] For example, assume that a multilayer circuit board 10 includes two capacitor structures 11, each capacitor structure 11 includes two dielectric layers 300. In the first capacitor structure 11, dielectric layer 1 and dielectric layer 2 are made of the same material, both of which are polyimide (PI) materials. In the second capacitor structure 11, dielectric layer 3 and dielectric layer 4 are made of different materials, dielectric layer 3 is polytetrafluoroethylene (PTFE) material, and dielectric layer 4 is glass fiber reinforced epoxy resin (FR-4) material.

[0083] When the materials of the multiple dielectric layers 300 are the same, consistent electrical performance can be provided, reducing the instability caused by material differences, which is beneficial to improving the reliability and performance consistency of the multi-layer circuit board 10 .

[0084] When the materials of the multiple dielectric layers 300 are different, the most suitable material can be selected according to the specific design requirements to achieve better electrical and mechanical properties. For example, PTFE material has a lower dielectric constant and loss, and is suitable for high-frequency applications; while FR-4 material has good mechanical strength and heat resistance, and is suitable for general applications. Factors such as electrical performance, mechanical performance, and cost can be balanced according to specific design requirements to achieve better overall performance and reliability.

[0085] As an optional implementation, the circuit board assembly 100 includes a plurality of dielectric layers 300 and a plurality of first metal layers 200 , and the plurality of dielectric layers 300 are sequentially spaced apart through the plurality of first metal layers 200 .

[0086] It can be understood that the number of dielectric layers 300 can be two, three, four, five, six, seven, eight, etc., and the number of first metal layers 200 can be two, three, four, five, six, seven, eight, etc. The embodiment of the present application does not limit the specific number of dielectric layers 300 and first metal layers 200, nor is it limited to the above examples.

[0087] It should be noted that multiple dielectric layers 300 are arranged in sequence through multiple first metal layers 200, which means that multiple dielectric layers 300 and multiple first metal layers 200 are alternately arranged, and one dielectric layer 300 is located between two adjacent first metal layers 200, thereby forming a capacitor structure 11 with multiple dielectric layers 300.

[0088] Through the above-mentioned settings, through the multi-layer settings of multiple dielectric layers 300 and multiple first metal layers 200, the levels of the capacitor structure 11 can be increased, thereby improving the capacity of the capacitor structure 11 and meeting performance requirements; the electric field distribution can be optimized, the electric field concentration phenomenon can be reduced, and the stability and performance of the capacitor structure 11 can be improved; the structural stability of the capacitor structure 11 can be enhanced, and the impact of external interference on the capacitor structure 11 can be reduced.

[0089] Reference Figure 1 and Figure 4 As shown, as an optional embodiment, the circuit board assembly 100 includes a first substrate 110, a fourth metal layer 120, a second substrate 130 and a third metal layer 500 which are stacked in sequence along the thickness direction, the second substrate 130 is located on the side of the fourth metal layer 120 away from the first substrate 110, and the third metal layer 500 is located on the side of the second substrate 130 away from the second metal layer 400.

[0090] It is understandable that the material of the fourth metal layer 120 may be the same as or different from the material of the first metal layer 200. The material of the fourth metal layer 120 may refer to the material of the first metal layer 200, and will not be described in detail here.

[0091] Through the above arrangement, the second substrate 130 is located on the side of the fourth metal layer 120 away from the first substrate 110, which helps to optimize the layout of the capacitor structure 11 and ensure the stability and performance of the capacitor structure 11. The third metal layer 500 is located on the side of the second substrate 130 away from the second metal layer 400, which helps to form the integrity of the capacitor structure 11 and improve the efficiency and performance of the capacitor structure 11.

[0092] Reference Figure 1and Figure 4 As shown, as an optional implementation, the first metal layer 200 is connected to the fourth metal layer 120 .

[0093] Through the above-mentioned settings, the stability and reliability of the capacitor structure 11 can be enhanced, the contact resistance and inductance in the capacitor structure 11 can be reduced, and the performance of the capacitor structure 11 can be improved; in addition, the conductivity and response speed of the capacitor structure 11 can be improved, thereby improving the performance of the entire circuit board; secondly, the structure of the multi-layer circuit board 10 can be simplified, and the number of components and connection points in the multi-layer circuit board 10 can be reduced, thereby reducing manufacturing costs and maintenance difficulties.

[0094] Reference Figure 1-Figure 4 As shown, as an optional implementation, the first substrate 110 includes a substrate body 111, a circuit pattern located outside the substrate body 111, and a prepreg 112, and the prepreg 112 fills the circuit pattern.

[0095] It is understandable that the circuit pattern can be obtained on the substrate body 111 through steps such as attaching a photosensitive film, exposing, developing, etching, and film stripping according to the designed pattern.

[0096] It should be noted that the material of the prepreg 112 can be any. For example, the material of the prepreg 112 can include but is not limited to glass fiber reinforced epoxy resin (FR-), polyimide (PI), polyetheretherketone (PEEK), etc. The embodiment of the present application does not limit the specific material of the prepreg 112, nor is it limited to the above examples.

[0097] Through the above-mentioned arrangement, the semi-cured sheet 112 can effectively protect the circuit pattern from the influence of the external environment, can enhance the stability and durability of the circuit pattern, and extend the service life of the multi-layer circuit board 10; in addition, it helps to strengthen the overall structure of the circuit board; secondly, it can increase the mechanical strength and vibration resistance of the multi-layer circuit board 10, and improve the stability and reliability of the multi-layer circuit board 10.

[0098] Reference Figure 1-Figure 4 As shown, as an optional embodiment, the second substrate 130 is a prepreg. It is understandable that the second substrate 130 can have the same structure as the substrate body 111 of the first substrate 110, and will not be described in detail here.

[0099] In the description of the embodiments of the present application, it should be understood that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the connection of the structures inside two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0100] The terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present application. In the description of the present application, "plurality" means two or more, unless otherwise specified.

[0101] The terms "first", "second", "third", "first", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0102] 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 it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for the structural or complete structural technical features therein. 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 multi-layer circuit board, characterized in that: include: A circuit board assembly, the circuit board assembly having a first hole and a second hole connected to each other, the second hole being closer to an end surface of the circuit board assembly relative to the first hole; A first metal layer covering the hole wall of the first hole; a dielectric layer covering a side of the first metal layer away from a hole wall of the first hole; The second metal layer covers the side of the dielectric layer away from the hole wall of the first hole and covers the hole wall of the second hole. The first metal layer, the second metal layer and the dielectric layer together form a capacitor structure.

2. The multilayer circuit board according to claim 1, characterized in that: The first hole is coaxially arranged with the second hole, and the aperture of the first hole is larger than the aperture of the second hole.

3. The multi-layer circuit board according to claim 2, characterized in that: The circuit board assembly comprises a third metal layer located on two opposite sides of the second metal layer, the third metal layer is spaced apart from the dielectric layer, and an extension direction of the third metal layer intersects with an extension direction of the second metal layer; The second metal layer is connected to the third metal layer.

4. The multi-layer circuit board according to claim 3, characterized in that: The number of the capacitor structures is multiple; Along the surface extension direction of the third metal layer, the plurality of capacitor structures are arranged at intervals, and adjacent capacitor structures are connected through the third metal layer.

5. The multi-layer circuit board according to claim 3, characterized in that: The number of the capacitor structures is multiple; Along the thickness direction of the circuit board assembly, the plurality of capacitor structures are arranged at intervals, and adjacent capacitor structures are connected via the third metal layer.

6. The multi-layer circuit board according to claim 1, characterized in that: The circuit board assembly includes a plurality of dielectric layers and a plurality of first metal layers, and the plurality of dielectric layers are sequentially spaced apart through the plurality of first metal layers.

7. The multilayer circuit board according to any one of claims 1 to 6, characterized in that: The circuit board assembly includes a first substrate, a fourth metal layer, a second substrate and a third metal layer stacked in sequence along the thickness direction, the second substrate is located on a side of the fourth metal layer away from the first substrate, and the third metal layer is located on a side of the second substrate away from the second metal layer.

8. The multi-layer circuit board according to claim 7, characterized in that: The first metal layer is connected to the fourth metal layer.

9. The multi-layer circuit board according to claim 7, characterized in that: The first substrate includes a substrate body, a circuit pattern located outside the substrate body, and a prepreg. The prepreg fills the circuit pattern.

10. The multi-layer circuit board according to claim 7, characterized in that: The second substrate is a prepreg.

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