Inner buried hole structure of multi-layer high-density interconnected printed circuit board

Abstract

The utility model discloses an inner layer buried hole structure of a multi-layer high density interconnection printed circuit board, comprising a circuit board main body, two ends of the circuit board main body are respectively covered with a first conductive layer, the outer end of the first conductive layer is covered with a second conductive layer, and the second conductive layer is covered with a second conductive layer. The circuit board main body and the first conducting layer are both provided with through buried holes, copper rings are fixedly installed in the buried holes, two ends of each copper ring extend outwards to form extension sheets, each extension sheet is provided with a plurality of cutting grooves, and the extension sheets are fixed between the first conducting layer and the second conducting layer. According to the utility model, the extension sheet is fixed on the surface of the first conductive layer, and the extension sheet is attached and fixed through the second conductive layer, so that the fixing stability of the copper ring in the buried hole is ensured, the situation that the copper ring in the buried hole of the circuit board is loosened during processing or use is avoided, and meanwhile, the extension sheet is processed in a grooving manner, so that the processing efficiency is improved. The requirement for the production technology is low, the machining cost of the copper ring is low, and practicability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit boards, in particular to an inner buried via structure of a multi-layer high-density interconnect printed circuit board. Background Art

[0002] A printed circuit board, also known as a printed wiring board, is a provider of electrical connections for electronic components. Its development has a history of more than 100 years; its design is mainly layout design; the main advantages of using a circuit board are to greatly reduce wiring and assembly errors, improve the automation level and production labor rate; according to the number of circuit board layers, it can be divided into single-sided boards, double-sided boards, four-layer boards, six-layer boards, and other multi-layer circuit boards.

[0003] For example, the patent with the application number: 202222921223.4 discloses a buried via structure of a circuit board, including a circuit main board, a buried via is opened at the top of the circuit main board, a copper ring is fixedly arranged on the inner wall of the buried via, filling grooves are respectively opened on the outer walls at both ends of the copper ring, a plurality of fixing blocks are fixedly arranged on the inner wall of the filling groove, insulating resin is filled in the inner wall of the filling groove, a plurality of fixing rings are fixedly arranged on the top inner wall of the copper ring, and two support rods are fixedly arranged on the inner walls of the plurality of fixing rings. The plurality of fixing rings are arranged at equal intervals, and the two support rods located inside the same fixing ring are arranged in a cross shape. Filling grooves are opened on the surface of the copper ring, a plurality of fixing blocks are installed inside the filling grooves, and by injecting insulating resin into the filling grooves, the effect of fixing the copper foil in the buried via is strengthened, and the phenomenon of loosening of the copper foil inside the buried via of the circuit board is avoided.

[0004] In view of the above related technologies, the inventor believes that in the above patent, a plurality of fixing blocks are arranged on the outer wall, and insulating resin is injected outside the fixing blocks to strengthen the fixing effect of the copper foil in the buried via. However, the opening of the fixing blocks outside the copper ring has certain requirements for the production process and high requirements for the production precision of the fixing blocks, and the practicability is insufficient. Therefore, an inner buried via structure of a multi-layer high-density interconnect printed circuit board is proposed. Content of the Utility Model

[0005] In order to solve the problems in the above background art, the utility model provides an inner buried via structure of a multi-layer high-density interconnect printed circuit board.

[0006] The utility model adopts the following technical scheme: an inner buried via structure of a multi-layer high-density interconnect printed circuit board, including a circuit board main body, first conductive layers are respectively covered and installed at both ends of the circuit board main body, a second conductive layer is covered and installed at the outer ends of the first conductive layers, through buried vias are opened in both the circuit board main body and the first conductive layers, a copper ring is fixedly installed in the buried vias, extension pieces extend outwards at both ends of the copper ring, a plurality of cutting grooves are opened on the extension pieces, and the extension pieces are fixed between the first conductive layer and the second conductive layer.

[0007] Preferably, the cutting grooves are equidistantly distributed on the extension piece and arranged along the axial direction of the copper ring, and the number of the cutting grooves is at least 4.

[0008] Preferably, a relief groove is formed at one end of the second conductive layer in contact with the first conductive layer. The position of the relief groove corresponds to the position of the extension piece, and the depth of the relief groove is consistent with the thickness of the extension piece.

[0009] Preferably, a filling groove is formed between the copper ring and the buried hole. The filling groove is filled with insulating resin.

[0010] Preferably, the filling groove is located at the position of the first conductive layer, and the resin filling does not overflow the surface of the first conductive layer.

[0011] Preferably, the inner wall of the buried hole is electroplated with a copper plating layer, and the copper plating layer is connected to the copper ring.

[0012] Preferably, connecting conductive plates are fixedly arranged at both ends of the circuit board main body, and the connecting conductive plates are electrically connected to the copper ring.

[0013] Preferably, an insulating layer is covered and installed between the circuit board main body and the first conductive layer.

[0014] Preferably, an insulating layer is covered and installed between the first conductive layer and the second conductive layer.

[0015] Preferably, both the copper ring and the buried hole are in a cylindrical structure.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] (1) In the present utility model, the extension piece is fixed on the surface of the first conductive layer, and the second conductive layer is used to fit and fix the extension piece, so as to ensure the stability of the copper ring fixed in the buried hole and avoid the loosening of the copper ring inside the buried hole of the circuit board during processing or use.

[0018] (2) In the present utility model, the copper ring is processed by cutting grooves on the extension piece, which is convenient for manufacturers to mass-produce the copper ring, has low requirements for the production process, low processing cost of the copper ring, and strong practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic cross-sectional view of the overall structure of the present utility model;

[0020] Figure 2 Schematic installation diagram of the copper ring structure of the present utility model;

[0021] Figure 3 Schematic diagram of the copper ring structure of the present utility model (state where the extension piece is bent);

[0022] Figure 4 Schematic diagram of the copper ring structure of the present utility model (state where the extension piece is straight).

[0023] In the figure: 1. Circuit board main body; 11. First conductive layer; 12. Second conductive layer; 2. Copper ring; 21. Extension piece; 211. Cutting groove; 22. Connecting conductive plate. Specific implementation manners

[0024] For ease of understanding the present utility model, the present utility model will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present utility model are given in the drawings. However, the present utility model can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the disclosure of the present utility model more thorough and comprehensive.

[0025] It should be noted that when an element is referred to as being "fixedly provided on" another element, it can be directly on the other element or there can be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs. The terms used in the description of the present utility model in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used herein includes any and all combinations of one or more of the related listed items. Embodiment 1

[0027] Please refer to Figures 1-4The utility model provides an inner buried hole structure of a multi-layer high-density interconnected printed circuit board, comprising a circuit board body 1, wherein both ends of the circuit board body 1 are respectively covered with a first conductive layer 11, and the outer end of the first conductive layer 11 is covered with a second conductive layer 12, and through buried holes are provided in the circuit board body 1 and the first conductive layer 11, and a copper ring 2 is fixedly installed in the buried hole, and an extension piece 21 is extended outwardly at both ends of the copper ring 2, and a plurality of grooves 211 are provided on the extension piece 21, and the extension piece 21 is fixed between the first conductive layer 11 and the second conductive layer 12, and is fixed on the surface of the first conductive layer 11 through the extension piece 21, and the extension piece 21 is fitted and fixed by the second conductive layer 12, so as to ensure the stability of the copper ring 2 in the buried hole, and avoid the copper ring 2 in the buried hole of the circuit board body 1 from loosening during processing or use, and at the same time, the extension piece 21 is processed by cutting grooves 211, which has low requirements on the production process, low processing cost of the copper ring 2, and strong practicality.

[0028] Please pay attention to Figures 2-4 The grooves 211 are evenly distributed on the extension piece 21 and are arranged along the axial direction of the copper ring 2. The number of the grooves 211 is at least 4. The extension piece 21 is divided by the grooves 211, which is convenient for bending and fixing the extension piece 21 to a certain extent during installation, reducing the fatigue effect of the extension caused by the bending, ensuring the tensile stability of the connection of the extension piece 21, and also ensuring the service life of the extension piece 21.

[0029] Please pay attention to Figure 1 A recess is formed at one end of the second conductive layer 12 that contacts the first conductive layer 11. The position of the recess corresponds to the position of the extension piece 21. The recess is used to reserve installation space for the extension piece 21 to avoid mutual squeezing between the conductive layers during installation. The depth of the recess is consistent with the thickness of the extension piece 21. The depth of the recess minimizes the impact on the second conductive layer 12 itself and ensures that the extension piece 21 is tightly fitted and fixed.

[0030] Please pay attention to Figure 1 A filling groove is also provided between the copper ring 2 and the buried hole. A filling groove is provided between the copper ring 2 and the buried hole. The filling groove is filled with insulating resin. The filling groove is located at the position of the first conductive layer 11. The resin filling does not overflow from the surface of the first conductive layer 11. The resin is flush with the surface of the first conductive layer 11. The copper ring 2 is adhered to the inner wall of the buried hole by filling the resin in the filling groove, so that the copper ring 2 is installed more closely on the circuit board body 1, and the stability of the copper ring 2 installed in the buried hole is further enhanced.

[0031] Please pay attention to Figure 1, a copper plating layer is electroplated on the inner wall of the buried hole. The copper plating layer is connected to the copper ring 2 and is electrically connected to the first conductive layer 11 and the second conductive layer 12, ensuring the connection between the circuit boards. At the same time, the connection between the circuit boards is ensured to be stable under the connection of the copper ring 2.

[0032] Please refer to Figures 1-2 , connection conductive plates 22 are fixedly arranged at both ends of the circuit board body 1. The connection conductive plates 22 are electrically connected to the copper ring 2, and the connection conductive plates are electrically connected to the first conductive layer 11 and the second conductive layer 12, further strengthening the stability of the connection between the circuit boards.

[0033] Please refer to Figure 1 , an insulating layer is covered and installed between the circuit board body 1 and the first conductive layer 11, and an insulating layer is covered and installed between the first conductive layer 11 and the second conductive layer 12.

[0034] Please refer to Figures 1-4 , both the copper ring 2 and the buried hole are in a cylindrical structure.

[0035] The working principle of the first embodiment of the present invention is as follows:

[0036] During use, perforations are made at the same positions of the circuit board body 1 and the first conductive layer 11, and the accuracy and flatness of the perforation positions are ensured. The first conductive layer 11 is adhered to the surface of the circuit board body 1. The copper ring 2 is inserted into the buried hole, and the copper ring 2 is electrically connected to the copper plating layer on the inner wall of the buried hole, enabling the connection between multiple circuit boards, ensuring subsequent electroplating operations. Insulating resin is injected into the filling groove between the outside of the copper ring 2 and the first conductive layer 11, and it is ensured that the resin filling does not overflow the surface of the first conductive layer 11, initially ensuring the stability of the copper ring 2 fixed in the buried hole. The extension pieces 21 at both ends of the bent arc copper ring 2 are bent so that the extension pieces 21 fit on the surface of the first conductive layer 11, thereby strengthening the fixation of the copper ring 2 and enhancing the strength of the structure of the copper ring 2 fixed inside the buried hole. The fixation stability is strong. Subsequently, the second conductive layer 12 is adhered to the surface of the first conductive layer 11 respectively, and the relief grooves of the second conductive layer 12 are aligned with the positions of the extension pieces 21, avoiding the influence of the thickness of the extension pieces 21 on the adhesion and fitting of the first conductive layer 11 and the second conductive layer 12, and ensuring the stability of the use of the circuit board body 1.

[0037] The above has made an exemplary description of the present invention in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as such non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An inner buried via structure of a multi-layer high-density interconnect printed circuit board, characterized in that: It includes a circuit board body (1), with first conductive layers (11) respectively covered and installed at both ends of the circuit board body (1), a second conductive layer (12) covered and installed at the outer end of the first conductive layer (11), through buried holes opened in both the circuit board body (1) and the first conductive layer (11), a copper ring (2) fixedly installed in the buried hole, extension pieces (21) extending outward at both ends of the copper ring (2), and a plurality of cutting grooves (211) opened in the extension pieces (21), and the extension pieces (21) are fixed between the first conductive layer (11) and the second conductive layer (12).

2. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 1, wherein: The cutting grooves (211) are equidistantly distributed on the extension pieces (21) and are arranged along the axial direction of the copper ring (2), and the number of the cutting grooves (211) is at least 4.

3. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 2, wherein: A relief groove is opened at one end of the second conductive layer (12) in contact with the first conductive layer (11), the position of the relief groove corresponds to the position of the extension piece (21), and the depth of the relief groove is consistent with the thickness of the extension piece (21).

4. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 1, characterized in that: A filling groove is opened between the copper ring (2) and the buried hole, and an insulating resin is filled in the filling groove.

5. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 4, characterized in that: The filling groove is located at the position of the first conductive layer (11), and the resin filling does not overflow the surface of the first conductive layer (11).

6. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 1, characterized in that: The inner wall of the buried hole is electroplated with a copper plating layer, and the copper plating layer is connected to the copper ring (2).

7. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 6, characterized in that: Connecting conductive plates (22) are also fixedly arranged at both ends of the circuit board body (1), and the connecting conductive plates (22) are electrically connected to the copper ring (2).

8. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 1, characterized in that: An insulating layer is covered and installed between the circuit board body (1) and the first conductive layer (11).

9. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 1, characterized in that: An insulating layer is covered and installed between the first conductive layer (11) and the second conductive layer (12).

10. The inner buried via structure of a multi-layer high-density interconnect printed circuit board according to claim 1, characterized in that: Both the copper ring (2) and the buried hole are in a cylindrical structure.

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