Circuit board structure

Abstract

The utility model discloses a circuit board structure, which comprises an insulating substrate, a copper foil, a conductive layer and a metal coating, and is characterized in that the insulating substrate is provided with an electroplating filling hole, and the electroplating filling hole penetrates through the insulating substrate along the thickness direction of the insulating substrate; the copper foil is arranged on one plate surface of the insulating substrate; the conductive layer is filled in the electroplating filling hole and is connected with the copper foil for electric conduction; and the metal coating is arranged on the exposed surfaces of the copper foil and the conductive layer. According to the circuit board structure, the conductivity of the circuit board can be improved, the use amount of the copper foil is reduced, and the material cost of the circuit board is further reduced.

Description

Technical Field

[0001] The invention relates to the field of circuit boards, and in particular to a circuit board structure. Background Art

[0002] Circuit boards usually use double-sided copper-clad laminates, that is, a layer of copper foil is set on each side of the insulating substrate. The purpose is to enhance the electrical performance and reliability of the circuit board. If there is a conductive path between the two layers of copper foil, then they can conduct electricity through these conductive paths. The conductive paths between the double-sided copper foils of the circuit board are usually very small, so the conductivity between them will be subject to some restrictions; at the same time, the use of double-layer copper foil makes the amount of copper foil required for the circuit board larger and the material cost higher.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] The present invention provides a circuit board structure, which at least solves the technical problem of how to improve the conductive performance of the circuit board and reduce the amount of copper foil used.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] A circuit board structure, comprising:

[0009] An insulating substrate having a plated hole, wherein the plated hole penetrates the insulating substrate along a thickness direction of the insulating substrate;

[0010] Copper foil, disposed on one of the surfaces of the insulating substrate;

[0011] A conductive layer is filled in the electroplated hole and is connected to the copper foil for electrical conduction;

[0012] The metal plating layer is arranged on the exposed surfaces of the copper foil and the conductive layer.

[0013] In some embodiments, the cross-sectional areas of the plated vias and the conductive layer gradually decrease in a direction toward the copper foil.

[0014] In some embodiments, one end of the conductive layer facing away from the copper foil is flush with the other surface of the insulating substrate.

[0015] In some embodiments, the metal plating layer is a chemical nickel-gold layer.

[0016] In some embodiments, the copper foil is etched to form a circuit structure.

[0017] In some embodiments, the conductive layer is a copper-plated layer.

[0018] In some embodiments, the conductive layer and the metal plating layer are made of chemical nickel gold.

[0019] The invention also provides a circuit board manufacturing method, which uses the above circuit board structure.

[0020] In some embodiments, the circuit board manufacturing method includes the following steps:

[0021] Pressing the copper foil onto one surface of the insulating substrate;

[0022] Performing laser drilling on the insulating substrate to form electroplating-filled holes on the insulating substrate;

[0023] forming a conductive layer inside the plated hole by electroplating;

[0024] Etching the copper foil to form a circuit structure;

[0025] The copper foil and the conductive layer are surface treated to form a metal plating layer on the exposed surfaces of the copper foil and the conductive layer.

[0026] In some embodiments, the via-filling electroplating step is omitted and the conductive layer is formed by surface treatment.

[0027] In some embodiments, the surface treatment comprises chemical nickel gold.

[0028] (III) Beneficial effects

[0029] Compared with the prior art, the circuit board structure provided by the present invention has the following beneficial effects:

[0030] When the circuit board structure is working, the metal plating, the conductive layer, the copper foil and another metal plating are conductive in sequence, wherein the circuit board structure only needs to set the copper foil on one board surface of the insulating substrate, which can effectively reduce the amount of copper foil used and reduce the material cost of manufacturing the circuit board; at the same time, the insulating substrate is opened with electroplated holes and filled with the conductive layer, and the copper foil is connected through the conductive layer. Compared with the existing fine conductive path, the cross-sectional area of ​​the conductive layer can be increased as needed, which is conducive to improving the conductive performance of the circuit board. It can be seen that the circuit board structure of the present invention can improve the conductive performance of the circuit board and reduce the amount of copper foil used, thereby reducing the material cost of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the circuit board structure in the embodiment.

[0032] Figure 2 Schematic diagram of a method for manufacturing a circuit board in an embodiment.

[0033] Reference numerals: insulating substrate 1 , copper foil 2 , conductive layer 3 , metal plating layer 4 , electroplating filling hole 10 . DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0035] The conductive paths between the double-sided copper foils of existing circuit boards are usually very fine, so the conductive performance between them is subject to some limitations; at the same time, the use of double-layer copper foil requires a larger amount of copper foil for the circuit board, resulting in higher material costs.

[0036] In order to solve the above technical problems, this embodiment provides a circuit board structure, please refer to Figure 1 and Figure 2 As shown, Figure 1 is a schematic diagram of a circuit board structure in an embodiment, Figure 2 Schematic diagram of a method for manufacturing a circuit board in an embodiment.

[0037] A circuit board structure of this embodiment includes: an insulating substrate 1, a copper foil 2, a conductive layer 3 and a metal plating layer 4.

[0038] The insulating substrate 1 is provided with a plated via 10 , and the plated via 10 penetrates the insulating substrate 1 along the thickness direction of the insulating substrate 1 .

[0039] The insulating substrate 1 has insulating and supporting functions and may be a glass fiber cloth substrate, wherein the electroplated filling holes 10 may be formed by laser drilling.

[0040] The copper foil 2 is provided on one surface of the insulating substrate 1 .

[0041] The copper foil 2 is used to form the conductive circuit of the circuit board, and can be formed together with the insulating substrate 1 by embossing; for example, the copper foil 2 and the insulating substrate 1 are tightly attached together to ensure that there are no bubbles or impurities sandwiched between the two, and then the bonded copper foil 2 and the insulating substrate 1 are placed in a hot press, and hot pressing is performed at appropriate temperature and pressure to tightly combine the copper foil 2 and the insulating substrate 1 together. After hot pressing, the copper foil 2 is etched to form the desired circuit pattern.

[0042] The conductive layer 3 fills the inside of the electroplated via 10 and is connected to the copper foil 2 for electrical conduction.

[0043] The conductive layer 3 is made of conductive material and is filled in the electroplating holes 10 by electroplating.

[0044] The metal plating layer 4 is provided on the exposed surfaces of the copper foil 2 and the conductive layer 3 .

[0045] The metal plating layer 4 has good electrical conductivity and corrosion resistance, prevents the copper surface from being oxidized or corroded, and has good welding performance.

[0046] When the circuit board structure is working, the metal plating layer 4, the conductive layer 3, the copper foil 2 and the other metal plating layer 4 are conductive in sequence, wherein the circuit board structure only needs to set the copper foil 2 on one board surface of the insulating substrate 1, which can effectively reduce the use of the copper foil 2 and reduce the material cost of manufacturing the circuit board; at the same time, the insulating substrate 1 is provided with a plated filling hole 10 and filled with the conductive layer 3, and the copper foil 2 is connected through the conductive layer 3. Compared with the existing fine conductive path, the cross-sectional area of ​​the conductive layer 3 can be increased as needed, which is conducive to improving the conductive performance of the circuit board. It can be seen that the circuit board structure of this embodiment can improve the conductive performance of the circuit board and reduce the amount of copper foil 2, thereby reducing the material cost of the circuit board.

[0047] In one embodiment of the above-mentioned electroplated via 10, the cross-sectional area of ​​the electroplated via 10 and the conductive layer 3 gradually decreases in the direction toward the copper foil 2. Compared with traditional cylindrical holes, more sufficient and uniform electroplating can be achieved, thereby accelerating the formation of the conductive layer 3.

[0048] Furthermore, one end of the conductive layer 3 facing away from the copper foil 2 is flush with the other board surface of the insulating substrate 1 .

[0049] The metal plating layer 4 can be a chemical nickel-gold layer. The main purpose of chemical nickel-gold is to be used as a surface treatment for circuit boards to prevent copper on the circuit board surface from being oxidized or corroded, and to be used for welding and contact (such as buttons, gold fingers on memory sticks, etc.). It has good contact conductivity and good assembly welding performance, and it can also be used in conjunction with other surface coating processes.

[0050] The copper foil 2 can be etched to form a circuit structure.

[0051] The conductive layer 3 may be a copper-plated layer.

[0052] See also Figure 1 As shown, this embodiment provides a method for manufacturing a circuit board to obtain the above-mentioned circuit board structure.

[0053] Further, see Figure 2 As shown, the circuit board manufacturing method includes the following steps:

[0054] To make a single-sided copper-clad laminate: a copper foil 2 is pressed onto one surface of an insulating substrate 1;

[0055] Laser drilling: performing laser drilling on the insulating substrate 1 to form electroplated filled holes 10 on the insulating substrate 1;

[0056] Filling hole electroplating: forming a conductive layer 3 inside the electroplating filling hole 10 by electroplating;

[0057] Circuit etching: performing circuit etching on the copper foil 2 to form a circuit structure on the copper foil 2;

[0058] Chemical nickel gold: Surface treatment is performed on the copper foil 2 and the conductive layer 3 to form a metal plating layer 4 on the exposed surfaces of the copper foil 2 and the conductive layer 3. Further, the surface treatment includes chemical nickel gold, such as electroless nickel immersion gold ENIG.

[0059] The order of the above steps can be adjusted as needed. For example, circuit etching can be performed after laser drilling, and then electroless nickel plating and immersion gold can be performed to simultaneously form a conductive layer 3 and a metal plating layer 4 of the same material.

[0060] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A circuit board structure, characterized in that: include: An insulating substrate having a plated hole, wherein the plated hole penetrates the insulating substrate along a thickness direction of the insulating substrate; Copper foil, the copper foil is arranged on one of the plate surfaces of the insulating substrate; A conductive layer is filled in the electroplated hole and is connected to the copper foil for electrical conduction; The metal plating layer is arranged on the exposed surfaces of the copper foil and the conductive layer.

2. The circuit board structure according to claim 1, characterized in that: The cross-sectional areas of the electroplated vias and the conductive layer gradually decrease in a direction toward the copper foil.

3. The circuit board structure according to claim 1, characterized in that: One end of the conductive layer facing away from the copper foil is flush with the other board surface of the insulating substrate.

4. The circuit board structure according to claim 1, characterized in that: The metal plating layer is a chemical nickel-gold layer.

5. The circuit board structure according to claim 1, characterized in that: The copper foil is etched to form a circuit structure.

6. The circuit board structure according to claim 1, characterized in that: The conductive layer is a copper-plated layer.

7. The circuit board structure according to claim 1, characterized in that: The conductive layer and the metal plating layer are made of chemical nickel-gold.

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