CN119155922A

CN119155922A - Processing method of buried copper circuit board and buried copper circuit board

Info

Publication number: CN119155922A
Application number: CN202411101834.1A
Authority: CN
Inventors: 李鸿辉; 曹振兴
Original assignee: Kalex MultiLayer Circuit Board Zhongshan Ltd
Current assignee: Kalex MultiLayer Circuit Board Zhongshan Ltd
Priority date: 2024-08-12
Filing date: 2024-08-12
Publication date: 2024-12-17

Abstract

The application relates to a processing method of a buried copper circuit board and the buried copper circuit board. The processing method of the buried copper circuit board comprises the steps of preparing an integral circuit board with a buried copper block and a welding column, drilling through holes on the integral circuit board, enabling the through holes to penetrate through the copper block, removing the welding column, and filling copper materials in the through holes to enable the copper materials to connect all circuit layers of the integral circuit board with the copper block. According to the processing method of the buried copper circuit board, the copper block is buried into the whole circuit board through the welding column to dissipate heat, then the welding column is removed through the through hole, the through hole is filled with copper materials, the copper block is conducted with each circuit layer of the whole circuit board, the contact area of the heat dissipation copper block and a high-current density area of the buried copper circuit board can be effectively increased, the heat dissipation exchange efficiency of the buried copper circuit board is improved, the heat dissipation performance is improved, the improvement of the processing efficiency and the processing precision is facilitated, the quality problem caused by the existence of the welding column is avoided, and the reliability of a product is improved.

Description

Processing method of buried copper circuit board and buried copper circuit board

Technical Field

The application relates to the technical field of circuit boards, in particular to a processing method of a copper-buried circuit board and the copper-buried circuit board.

Background

With the continuous progress of technology, electronic devices have increasingly powerful functions and higher requirements for heat dissipation. Therefore, various heat dissipation circuit boards become an integral part of modern electronic devices.

In the related art, copper particles are embedded in a Printed Circuit Board (PCB) to dissipate heat. However, the contact area between the copper particles and the high-current density region in the circuit board is small, so that the heat exchange efficiency is limited, insufficient heat transfer is caused, the heat dissipation efficiency is weakened, and the heat dissipation performance of the heat dissipation circuit board is affected.

Disclosure of Invention

Accordingly, it is necessary to provide a method for processing a copper-embedded circuit board and a copper-embedded circuit board, which solve the problem that the heat dissipation performance is affected by the small contact area between copper particles and a high current density region in the circuit board.

In a first aspect, a method for processing a copper-embedded circuit board is provided, including:

Preparing an integral circuit board with embedded copper blocks and welding columns;

drilling a through hole on the integral circuit board, enabling the through hole to penetrate through the copper block and removing the welding column;

and filling copper materials in the through holes, so that the copper materials connect all circuit layers of the whole circuit board with the copper blocks.

In some embodiments, the aperture of the through hole is 4 mils to 6 mils larger than the outer diameter of the welding post.

In some embodiments, the through hole comprises one of a circular hole, an elliptical hole, a polygonal hole.

In some embodiments, the filling copper material in the through hole includes:

carrying out copper deposition and plate electric treatment on the integral circuit board, and manufacturing a plating resist layer;

And filling the through holes by hole filling electroplating, so that the through holes are filled with copper.

In some embodiments, the preparing a monolithic circuit board with embedded copper blocks and solder columns includes:

fixing the copper block on the substrate through a welding column to obtain a heat dissipation core plate;

and pressing and fixing the heat dissipation core plate and at least one circuit core plate to obtain the integral circuit board with the embedded copper block and the welding column.

In some embodiments, at least one side of the circuit core board is provided with the circuit layer, the circuit core board comprises a copper-clad plate, and the circuit layer is a copper layer formed with a circuit pattern.

In some embodiments, the heat-dissipating core plate comprises a plurality of copper blocks, and the end surfaces of the copper blocks are flush along the axial direction of the through hole.

In some embodiments, the copper block has a thickness in the range of 300 microns to 800 microns.

In some embodiments, the shape of the copper block includes one of square, cylindrical, polygonal, and line shapes.

In a second aspect, a copper-embedded circuit board is provided, where the copper-embedded circuit board is prepared by the processing method of the copper-embedded circuit board in any one of the first aspects.

According to the processing method of the embedded copper circuit board and the embedded copper circuit board, the copper block is embedded into the whole circuit board through the welding column to dissipate heat, the welding column is removed through the through hole, the copper material is used for filling the through hole, the copper block is conducted with each circuit layer of the whole circuit board, the contact area of the heat dissipation copper block and the high-current density area of the embedded copper circuit board can be effectively increased, the heat dissipation exchange efficiency of the embedded copper circuit board is improved, the heat dissipation performance is improved, the processing efficiency and the processing precision are improved, the quality problem caused by the existence of the welding column is avoided, the reliability of a product is improved, and the problem that the circuit board is easy to explode and the heat dissipation exchange efficiency is poor is solved.

Drawings

Fig. 1 is a flow chart illustrating a method for processing a copper-clad circuit board according to some embodiments of the present application.

Fig. 2 is a schematic structural diagram of an overall circuit board according to some embodiments of the application.

Fig. 3 is a schematic illustration of drilling vias in an integrated circuit board according to some embodiments of the application.

Fig. 4 is a schematic structural diagram of a copper-clad circuit board according to some embodiments of the present application.

Fig. 5 is a schematic structural diagram of a heat sink core according to some embodiments of the present application.

Reference numerals:

100. the circuit board comprises a buried copper circuit board, a10 whole circuit board, a1 heat dissipation core board, a 11 substrate, a12 copper foil, a2 copper block, a 3 welding column, a4 circuit core board, a101 through hole, a 20 copper material.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present application, the terms "mounted," "connected," "secured," and the like are to be construed broadly, unless otherwise specifically indicated and defined. For example, they may be fixedly connected, detachably connected or integrally formed, mechanically connected, electrically connected, directly connected or indirectly connected through an intermediate medium, and communicated between two elements or the interaction relationship between two elements unless clearly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It is noted that an element is referred to as being "fixed" or "disposed" on another element, and may be directly on the other element or intervening elements may also be present. One element is considered to be "connected" to another element, which may be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Referring to fig. 1, fig. 1 is a flow chart illustrating a processing method of a copper-embedded circuit board according to some embodiments of the present application, where the processing method of the copper-embedded circuit board according to the embodiment of the present application includes the following steps:

step S100, preparing an integral circuit board with embedded copper blocks and welding columns;

Step S200, drilling through holes on the whole circuit board, enabling the through holes to penetrate through the copper block and removing the welding columns;

and step S300, filling copper material in the through hole, so that the copper material connects all circuit layers of the whole circuit board with the copper block.

Referring to fig. 2, fig. 2 shows a schematic structural diagram of an integrated circuit board 10 according to some embodiments of the present application, at least one copper block 2 is embedded in the integrated circuit board 10, so that the heat dissipation performance of the integrated circuit board 10 can be greatly improved, for example, the number of copper blocks 2 can be 1, 2, 3, 5 or more, each copper block 2 is embedded in the integrated circuit board 10 through at least one welding post 3 to dissipate heat, the processing efficiency and the processing precision are higher, wherein, along the thickness direction of the integrated circuit board 10, the projection of the welding post 3 is located in the projection range of the copper block 2, and the welding post 3 can be a welding copper post.

Referring to fig. 3, fig. 3 shows a schematic view of drilling a through hole 101 in a monolithic circuit board 10 according to some embodiments of the present application, drilling a via hole 101 through the copper block 2 and the solder post 3 using a drill such that the through hole 101 penetrates opposite sides of the monolithic circuit board 10 and penetrates the copper block 2 while removing the solder post 3, wherein an inner diameter of the via hole 101 is larger than a diameter of the solder post 3 and smaller than a length and width dimension of the copper block 2, and the length and width dimension of the copper block 2 refer to a dimension of the copper block 2 perpendicular to an axial direction of the via hole 101. For example, the drilling machine may include a laser drilling device that burns through the entire circuit board 10 with a laser. By removing the welding column 3 and simultaneously retaining the copper block 2, quality problems caused by the existence of the welding column 3, such as the problems of poor binding force, circuit board explosion-proof plate and the like, can be avoided, and meanwhile, the heat dissipation performance and the product reliability are improved.

Referring to fig. 4, fig. 4 shows a schematic structure of a buried copper circuit board 100 according to some embodiments of the present application, after a through hole 101 is drilled in an integrated circuit board 10, the through hole 101 is filled with a copper material 20, so that the copper material 20 forms a copper pillar having the same shape as the through hole 101, and the through hole 101 penetrates through each circuit layer of the integrated circuit board 10 and the copper block 2, so that the copper material 20 filled in the through hole 101 can communicate all the circuit layers of the integrated circuit board 10 with the copper block 2. Thus, the contact area between the heat dissipation copper block 2 and the high-current density area of the buried copper circuit board 100 can be effectively increased, the heat dissipation exchange efficiency of the buried copper circuit board 100 is improved, the heat transfer is sufficient, the heat dissipation efficiency is improved, and the heat dissipation performance of the buried copper circuit board 100 is improved.

According to the processing method of the buried copper circuit board 100, the copper block 2 is buried into the whole circuit board 10 through the welding post 3 for heat dissipation, then the welding post 3 is removed through the through hole 101 and the through hole 101 is filled with the copper material 20, so that each circuit layer of the copper block 2 and the whole circuit board 10 is conducted, the contact area of the heat dissipation copper block 2 and a high-current density area of the buried copper circuit board 100 can be effectively increased, the heat dissipation and exchange efficiency of the buried copper circuit board 100 is improved, the heat dissipation performance is improved, the processing efficiency and the processing precision are improved, the quality problem caused by the existence of the welding post 3 is avoided, the reliability of products is improved, and the problems of poor binding force, explosive plates and poor heat dissipation and exchange efficiency are solved.

In some embodiments, the aperture of the through hole 101 is 4 mils to 6 mils larger than the outer diameter of the weld stud 3.

1 Mil is equal to about 0.0254 mm, 4 mil is equal to 0.1016 mm, and 6 mil is equal to 0.1524 mm. By providing the through hole 101 with a hole diameter at least 4 mils, i.e. about 0.1 mm, larger than the diameter of the welding post 3, it is ensured that the welding post 3 can be removed by drilling the through hole 101, the machining precision requirement is reduced, and the machining efficiency is improved.

In some embodiments, the through hole 101 includes one of a circular hole, an elliptical hole, and a polygonal hole.

For example, the polygonal holes may be triangular holes, square holes, pentagonal holes, hexagonal holes, and the like. The through holes 101 can be set to different cross-sectional shapes according to actual needs, so that the processing is convenient and flexible, and the actual needs are met.

In some embodiments, the copper material 20 is filled in the through hole 101, specifically including the following steps:

step S301, copper deposition and plating treatment are carried out on the whole circuit board 10, and a plating resist layer is manufactured;

in step S302, hole filling electroplating is performed to fill the through hole 101, so that the through hole 101 is filled with the copper material 20.

The whole circuit board 10 is subjected to copper deposition and plate surface electroplating treatment, namely, a copper layer which is used for conducting between the pattern circuit layers is deposited in the through holes 101 by a chemical copper deposition method of the whole circuit board 10, the through holes 101 are conductive holes formed by two or more adjacent pattern circuit layers, and the whole circuit board 10 is electroplated with copper by a full-plate electroplating method so as to thicken the plate surface of the whole circuit board 10 and the thickness of the copper layer in the holes of the through holes 101.

And (3) manufacturing a plating resist, namely manufacturing the plating resist on the surface of the whole circuit board 10 so as to avoid continuously increasing the thickness of the copper layer on the surface of the whole circuit board 10 in the subsequent hole filling electroplating process.

Filling the through holes 101 by hole filling electroplating, namely filling the through holes 101 with copper materials 20 by a hole filling copper electroplating method, forming copper columns by the copper materials 20 filled in the through holes 101, and conducting the copper blocks 2 to all circuit layers of the whole circuit board 10.

In some embodiments, conventional post-processing steps including, for example, outer dry film, line plating and outer etch, outer line inspection, solder resist ink, surface treatment, routing, electrical testing, and final inspection may also be included after the via filling plating fills the via 101.

In some embodiments, the monolithic circuit board 10 with the embedded copper block 2 and the solder columns 3 is prepared, specifically comprising the steps of:

Step S101, fixing a copper block 2 on a substrate 11 through a welding post 3 to obtain a heat dissipation core plate 1;

step S102, the heat dissipation core plate 1 and at least one circuit core plate 4 are pressed and fixed to obtain the integrated circuit board 10 with the embedded copper block 2 and the welding column 3.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a heat dissipating core board 1 according to some embodiments of the present application, and a substrate 11 may be a board made of a glue insulating material, such as a prepreg. The process of fixing the copper block 2 to the substrate 11 through the solder columns 3 may include fixedly connecting at least one solder column 3 to the copper block 2, embedding the solder columns 3 into the substrate 11, and fixedly connecting the copper block 2 to a set position on the substrate 11 through the solder columns 3, the set position may be a position aligned with a circuit layer on an adjacent circuit core board 4, thereby obtaining the heat dissipation core board 1 to which the copper block 2 is combined and fixed. The heat dissipation core plate 1 can further comprise a copper foil 12 arranged on the surface, deviating from the copper block 2, of the substrate 11, and the welding column 3 penetrates through the substrate 11 to be connected with the copper foil 12, so that the bonding force between the copper block 2 and the substrate 11 and the bonding force between the copper foil 12 are improved, the heat transfer efficiency is improved, and the heat dissipation performance is further improved. The resin fluidity of the prepreg or the high-heat-conductivity insulating material can be utilized under the action of certain temperature and pressure, and the resin is solidified when the temperature reaches a certain degree, so that the copper block 2, the substrate 11 and the copper foil 12 are bonded together, and the bonding force of the copper block 2, the substrate 11 and the copper foil 12 is further improved. The copper block 2 is fixed on the substrate 11 by using the welding column 3, so that the position of the copper block 2 is fixed, and the relative position of the copper block 2 and the circuit layer on the aligned circuit core plate 4 is fixed, thereby being beneficial to improving the heat transfer efficiency of the copper block 2, improving the heat dissipation performance and improving the processing efficiency and the processing precision.

The circuit core 4 may be a semifinished circuit board with pre-printed circuits, i.e. the circuit core 4 has a circuit layer. The process flow of laminating and fixing the heat-dissipating core plate 1 and the at least one circuit core plate 4 may include laminating the heat-dissipating core plate 1 and the at least one circuit core plate 4, in which the copper block 2 is combined and fixed, according to a lamination structure of the buried copper circuit board 100, and then curing the heat-dissipating core plate 1 and the at least one circuit core plate 4 by using resin fluidity of prepreg or high heat-conducting insulating material under a certain temperature and pressure, and curing the heat-dissipating core plate when the temperature reaches a certain degree, thereby obtaining the integral circuit board 10. Because the prepreg or other insulating resin material has adhesive property and can flow in a melting way under high temperature and high pressure, smaller gaps among the circuit core board 4, the heat dissipation core board 1 and the copper blocks 2 can be gradually filled in the pressing process, and the embedded copper blocks 2, the heat dissipation core board 1 and at least one circuit core board 4 can be adhered into a whole after solidification.

In some embodiments, the number of circuit core boards 4 may be at least two, the heat dissipation core board 1 with the copper block 2 fixed thereon is pressed between the at least two circuit core boards 4, that is, the heat dissipation core board 1 with the copper block 2 fixed thereon is sandwiched between the at least two circuit core boards 4, for example, 2 to 30 circuit core boards 4 are stacked, and the circuit of the circuit core boards 4 of different layers are electrically interconnected to perform a specific function, that is, the overall circuit board 10 may be a multi-layer circuit board with 2 to 30 layers. Thus, the overall circuit board 10 has high assembly density, small volume, light weight, easy installation and high reliability, and is beneficial to the light miniaturization of electronic equipment.

In some embodiments, the circuit core board 4 may be at least one of an FR-4 circuit board, a teflon circuit board, a CAM-3 circuit board, a hydrocarbon resin circuit board, a BT resin circuit board, a polyimide circuit board. Wherein FR-4 is a code of a flame-retardant material grade, and represents a material specification that means that the resin material must be able to self-extinguish after passing through a burning state; the FR-4 grade material used for the circuit board may be a composite material made of a tetra-functional (Tera-functional) epoxy resin plus a Filler (Filler) and glass fibers. Teflon refers to polytetrafluoroethylene. Hydrocarbon resins refer to polyolefin homopolymers or copolymers including, but not limited to, butadiene styrene copolymers, butadiene homopolymers, styrene/divinylbenzene copolymers, styrene-butadiene-divinylbenzene copolymers, and the like, and BT resins refer to bismaleimide triazine resins that are chemically resistant, insulative, and heat resistant.

In some embodiments, the heat-dissipating core board 1 and the at least one circuit core board 4 may further comprise a conventional pre-process for processing the circuit core board 4, for example, the conventional pre-process includes cutting, circuit layer pattern circuit transfer, circuit layer etching, circuit layer circuit inspection, browning, and the like.

In some embodiments, at least one side of the circuit core board 4 is provided with a circuit layer, and the circuit core board 4 comprises a copper-clad plate and the circuit layer is a copper layer formed with a circuit pattern.

The circuit board 4 may have a circuit pattern formed on one side or may have a circuit pattern formed on both sides, and is not limited thereto. The circuit core board 4 may be a copper-clad plate having a circuit pattern formed on a copper layer thereof to thereby form a circuit layer.

In some embodiments, the heat-dissipating core plate 1 comprises a plurality of copper blocks 2, and the end surfaces of the plurality of copper blocks 2 are flush along the axial direction of the through holes 101.

The heat radiation core plate 1 is fixedly provided with a plurality of copper blocks 2 in a combined way, which is beneficial to improving the heat radiation performance, and the copper blocks 2 are positioned on the same plane. Thus, the thickness difference among the copper blocks 2 is reduced, the problem of flatness of the buried copper circuit board 100 caused by the thickness difference is avoided, the flatness of the surface of the buried copper circuit board 100 is improved, and the overall thickness of the buried copper circuit board 100 is reduced.

In some embodiments, the copper block 2 has a thickness in the range of 300 microns to 800 microns.

The thickness of the copper block 2 refers to the dimension in the axial direction of the through hole 101. The thickness of the copper block 2 is greater than or equal to 300 micrometers and less than or equal to 800 micrometers, i.e., the thickness of the copper block 2 is greater than or equal to 8OZ and less than or equal to 22OZ. Thus, the heat dissipation performance of the buried copper circuit board 100 is advantageously improved.

In some embodiments, the copper block 2 has a length or width of 10.2 millimeters or 12.2 millimeters.

The length of the copper block 2 refers to the dimension in the direction perpendicular to the axial direction of the through hole 101, and the width of the copper block 2 refers to the dimension in the direction perpendicular to the length direction of the copper block 2 and perpendicular to the axial direction of the through hole 101. The length of the copper block 2 may be 10.2 mm or 12.2 mm, or the width of the copper block 2 may be 10.2 mm or 12.2 mm, which is not limited herein. Thus, the copper block 2 has a larger heat dissipation area, which is advantageous for improving the heat dissipation performance of the buried copper circuit board 100.

In some embodiments, the shape of the copper block 2 includes one of square, cylindrical, polygonal column, and line shape.

For example, the polygonal column may be a triangular column, a quadrangular column, a pentagonal column, a hexagonal column, an octagonal column, or the like. The shape of the copper block 2 may be a line shape, meaning that the shape of the copper block 2 is identical to the line shape of the line core 4 adjacent to the heat sink core 1, i.e., the width and length of the copper block 2 are identical to the width and length of the partial line of the line core 4 with which it is aligned. In some embodiments, the copper blocks 2 are etched according to a required shape such as current trend (i.e. line shape), and the pattern shape formed by arranging the plurality of copper blocks 2 on the heat dissipation core board 1 is the same as the shape of the line pattern of the line core board 4 adjacent to the heat dissipation core board 1. The copper block 2 can be set into different shapes according to actual needs, the processing is convenient and flexible, the heat transfer efficiency of the copper block 2 is improved, the heat dissipation effect is improved, and the actual needs are met.

Referring to fig. 4, the copper-buried circuit board 100 provided by the embodiment of the application is prepared by the processing method of the copper-buried circuit board 100 in any of the above embodiments.

The buried copper circuit board 100 of the embodiment of the present application has the same advantages as the processing method of the buried copper circuit board 100 of the above embodiment, and will not be described herein.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A method for processing a buried copper circuit board, characterized by comprising:

preparing an integral circuit board having embedded copper blocks and welding posts;

Drilling a through hole on the integral circuit board so that the through hole passes through the copper block and removes the welding column;

The through hole is filled with copper material, so that the copper material connects all circuit layers of the overall circuit board with the copper block.

2. The method for processing a buried copper circuit board according to claim 1, wherein the aperture of the through hole is 4 mils to 6 mils larger than the outer diameter of the welding column.

3. The method for processing a buried copper circuit board according to claim 1, characterized in that the through hole comprises one of a circular hole, an elliptical hole, and a polygonal hole.

4. The method for processing a buried copper circuit board according to claim 1, wherein the step of filling the through hole with copper material comprises:

Performing copper deposition and board electrical processing on the overall circuit board, and making a resist coating;

The through-holes are filled with copper material by performing hole-filling electroplating.

5. The method for processing a buried copper circuit board according to any one of claims 1 to 4, characterized in that the preparation of an integral circuit board having buried copper blocks and welding columns comprises:

The copper block is fixed to the base plate by welding columns to obtain a heat dissipation core plate;

The heat dissipation core board is pressed and fixed with at least one circuit core board to obtain the integral circuit board with embedded copper blocks and welding columns.

6. The processing method of a buried copper circuit board according to claim 5 is characterized in that the circuit layer is provided on at least one side of the circuit core board; the circuit core board includes a copper clad board, and the circuit layer is a copper layer formed with a circuit pattern.

7. The processing method of the buried copper circuit board according to claim 5 is characterized in that the heat dissipation core board includes a plurality of the copper blocks; along the axial direction of the through hole, the end surfaces of the plurality of the copper blocks are flush.

8. The method for processing a buried copper circuit board according to claim 5, characterized in that the thickness of the copper block ranges from 300 microns to 800 microns.

9. The method for processing a buried copper circuit board according to any one of claims 1 to 4, characterized in that the shape of the copper block includes one of a square, a cylinder, a polygonal column and a circuit shape.

10. A buried copper circuit board, characterized in that the buried copper circuit board is prepared by the buried copper circuit board processing method according to any one of claims 1 to 9.