CN115279036A

CN115279036A - Substrate splicing method of circuit board

Info

Publication number: CN115279036A
Application number: CN202211068887.9A
Authority: CN
Inventors: 朱彦元; 谈勇; 朱永刚; 梁嘉林
Original assignee: Shenzhen Shunentropy Technology Co ltd
Current assignee: Shenzhen Shunentropy Technology Co ltd
Priority date: 2022-09-02
Filing date: 2022-09-02
Publication date: 2022-11-01

Abstract

The invention discloses a substrate splicing method of a circuit board, relating to the field of integrated circuit boards; the method comprises the following steps: (1) designing a lap joint structure on the periphery of the flat heat pipe; (2) frame hole sites are formed on the frame; a frame slot is designed on the side wall of the frame hole site; (3) A plurality of flat heat pipes are fixed on the hole positions of the frame by correspondingly welding the lapping structures and the groove positions of the frame to form a whole substrate; (4) flattening the surface of the substrate by a pressing device; (5) Attaching a heat conduction insulating layer to the surface of the substrate in the step (4); (6) The surface of the substrate is bonded with a conducting layer, a solder mask layer, an electronic component and the like to finish preprocessing; (7) Cutting the preprocessed circuit board, and removing the frame part to obtain the circuit board; (8) The flat heat pipe realizes the heat conduction function through the processes of liquid injection, vacuum pumping, degassing, sealing and the like. The invention replaces the substrate of the traditional circuit board by the flat heat pipe, has good heat dispersion performance and is beneficial to the development of a high-integrated circuit board.

Description

Substrate splicing method of circuit board

Technical Field

The invention relates to the technical field of integrated circuit boards, in particular to a substrate splicing method of a circuit board.

Background

Excessive temperatures can affect the performance of electronic components and even lead to device failure. With the increasing and increasing functions of various electronic devices, the number of electronic components in a unit area of a circuit board is increasing, and the performance is also increasing. The heat dissipation problem of the circuit board is getting worse and worse. The traditional circuit board adopts materials such as glass fiber cloth, ceramics and the like as a substrate, has low heat conductivity coefficient and extremely limited heat dissipation performance, and is not beneficial to the development of high-integration circuit boards.

Disclosure of Invention

The invention aims to provide a substrate splicing method of a circuit board, which aims to solve the problems in the prior art, replaces the substrate of the traditional circuit board by a flat heat pipe, has good heat dissipation performance and is beneficial to the development of a high-integrated circuit board.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a substrate splicing method of a circuit board, which takes a flat heat pipe as a circuit board substrate, arranges circuits and electronic components on the surface, is favorable for enhancing the heat dispersion, reduces local hot spots, improves the performance of the components and promotes the integration of the circuit board, and comprises two process schemes:

according to the scheme I, a flat heat pipe is directly used as a substrate and is integrally processed with a conducting layer, an electronic component and the like, and the method specifically comprises the following steps:

(1) Designing a lap joint structure on the periphery of a flat heat pipe with a heat dissipation structure;

(2) Providing a corresponding frame, wherein the frame material is the same as that of the flat heat pipe shell, a plurality of frame hole sites are formed in the frame, and each frame hole site is used for correspondingly placing one flat heat pipe; a frame groove position corresponding to the lap joint structure on the periphery of the flat heat pipe is designed on the side wall of the frame hole position;

(3) The lap joint structure is correspondingly welded with the frame groove position through the flat heat pipe lap joint structure, the lap joint structure is fixed with the frame groove position through resistance welding, and a plurality of flat heat pipes are fixed on the frame hole position;

(4) The flat heat pipes and the frame form a whole substrate, and the surface of the substrate is leveled by pressure equipment.

(5) Attaching a heat conduction insulating layer on the surface of the substrate for subsequent processing of the circuit board;

(6) One side that the substrate surface laminating has heat conduction insulation layer processes such as laminating conducting layer, solder mask, electronic components, accomplishes the preprocessing of circuit board, and the process of traditional circuit board can be referred to substrate surface printed circuit, roughly: (i) And pressing the copper foil on the other side of the heat conduction insulating layer, and attaching a photosensitive film. (ii) And irradiating the photosensitive film on the copper foil by using a UV lamp, curing the photosensitive film under the light-transmitting film, and curing the photosensitive film under the light-tight film. The copper foil covered under the cured photosensitive film is the required circuit board layout circuit. (iii) The uncured photosensitive film was cleaned away to expose the copper foil portion. (iv) The copper foil is removed by chemical etching, and then a solder resist is attached. (v) Finally tearing off the photosensitive film to expose the conductive circuit, namely the conductive layer;

(7) After the preprocessed circuit board is pasted with electronic components, the circuit board is cut, and the frame part is removed, so that a plurality of circuit boards integrated with the base plate with the heat dissipation structure are obtained.

(8) The flat heat pipe of the circuit board is subjected to the processes of liquid injection, vacuum pumping, degassing, sealing and the like, so that the function of efficient heat conduction of the flat heat pipe is realized. In the process of printing electronic components on a circuit board, high-temperature treatment is required. If the flat heat pipe finishes the procedures of liquid injection, air extraction and the like, the flat heat pipe cannot bear the high temperature and can expand; in order to avoid the influence of high temperature on the flat heat pipe, the step (8) is performed after electronic components are printed in the first scheme.

Scheme two, use the copper to combine as the second base plate as integrated processing such as first base plate and conducting layer, electronic components, again with dull and stereotyped heat pipe, concrete step includes:

(2) The flat heat pipe realizes the function of high-efficiency heat conduction through the processes of liquid injection, vacuum pumping, degassing, sealing and the like.

(3) Correspondingly welding the flat heat pipe lap joint structure with the frame groove position, fixing the lap joint structure with the frame groove position through resistance welding, and fixing a plurality of flat heat pipes on the frame hole position;

(4) And the plurality of flat heat pipes and the frame form a whole substrate, and the surface of the substrate is leveled through pressure equipment to obtain a second substrate of the flat heat pipes.

(5) Use the copper as first base plate, the heat conduction insulating layer is laminated on the surface of first base plate one side, and the process such as conducting layer, solder mask, electronic components are laminated on one side that first base plate surface laminating has heat conduction insulating layer, accomplishes the preprocessing of circuit board, and the process of traditional circuit board can be referred to base plate surface printed circuit, roughly: (i) And pressing the copper foil on the other side of the heat conduction insulating layer, and attaching a photosensitive film. (ii) And irradiating the photosensitive film on the copper foil by using a UV lamp, wherein the photosensitive film is cured under the light-transmitting film, and the photosensitive film which is not cured is under the light-transmitting film. The copper foil covered under the cured photosensitive film is the required circuit board layout circuit. (iii) The uncured photosensitive film was cleaned away to expose the copper foil portion. (iv) The copper foil is removed by chemical etching, and then a solder resist is attached. (v) Finally tearing off the photosensitive film to expose the conductive circuit, namely the conductive layer;

(6) The first substrate (copper) is not bonded to one side of the structure such as a conductive layer, and is bonded to the second substrate (flat heat pipe), optionally by soldering with low temperature solder paste, or by high strength heat conductive silicone grease.

(7) And cutting to remove the frame part of the second substrate and the redundant part of the first substrate to obtain a plurality of circuit boards integrated with the substrates with the heat dissipation structures. In the second scheme, the electronic components are arranged on the copper plate and are separately processed with the flat heat pipe, and the electronic components and the flat heat pipe are attached together after respective processing is finished, so that the flat heat pipe is independently arranged through the processes of liquid injection, vacuum pumping, degassing, sealing and the like, and the process of printing the electronic components cannot be influenced.

In different embodiments, a borderless splicing manner can also be adopted: the periphery of the flat heat pipe is provided with a groove position, the adjacent flat heat pipes are provided with lap joint structures, and the flat heat pipes are directly spliced with each other.

Optionally, the flat heat pipe is a closed hollow cavity and comprises a casing, the lap joint structure is arranged on the periphery of the casing, the lap joint structure is integrally formed with the upper cover plate of the casing or the lower cover plate of the casing, and the upper cover plate and the lower cover plate of the casing are welded through diffusion welding or brazing.

Optionally, a support column is fixedly connected between the upper cover plate and the lower cover plate of the shell, and a steam cavity is formed between the support columns; the heat dissipation structure comprises a liquid absorption core and working liquid filled in the steam cavity, and the liquid absorption core is fixedly attached to the inner wall of one side, provided with the electronic component, of the flat heat pipe.

Optionally, a liquid absorption core column is connected between the liquid absorption core and the inner wall of the side, far away from the electronic component, of the flat heat pipe, and the liquid absorption core column inside the flat heat pipe plays a role in promoting the backflow of the working liquid.

Optionally, the housing is made of copper, aluminum, stainless steel or ceramic.

Optionally, the wick is made of one or a combination of a plurality of sintered copper powder, a copper wire mesh, a groove, foam copper, a micro-cylinder and a surface micro-nano structure.

Optionally, a plurality of conductive layers are disposed on the heat conducting insulating layer, and the solder resist layer and the conductive layer located at the outermost layer are disposed at fixed intervals; the adjacent two conductive layers are separated by a semi-solidified insulating sheet; guide holes are formed in the positions of the conducting layers, and different conducting layers can be connected through the guide holes.

Optionally, for a component with higher heating power, a heat-conducting column may be designed, and the heat-conducting column is fixedly connected between the electronic component and the heat-conducting insulating layer.

Compared with the prior art, the invention has the following technical effects:

the invention replaces the substrate of the traditional circuit board with the flat heat pipe, improves the heat dissipation effect and is beneficial to improving the performance of electronic components. The invention is beneficial to promoting the temperature uniformity of the circuit board, reducing local hot spots and integrating more electronic components on the circuit board. The invention can be suitable for the large-scale production of the circuit board.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic diagram of an overall structure of a circuit board according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of the external structure of the flat heat pipe according to the present invention;

FIG. 3 isbase:Sub>A schematic cross-sectional view taken along line A-A of FIG. 2 in accordance with the present invention;

FIG. 4 is a schematic view of the present invention used in a multilayer circuit board;

FIG. 5 is a schematic view of the assembly of the flat heat pipe and the frame of the present invention;

FIG. 6 is a schematic view illustrating an assembly process of a flat heat pipe and a flat heat pipe according to the present invention;

FIG. 7 is a first overlapping structure of the flat heat pipe according to the present invention;

FIG. 8 is a second overlapping structure of the flat plate heat pipe of the present invention;

FIG. 9 is a third overlapping structure of the flat heat pipe according to the present invention;

FIG. 10 is a fourth overlapping structure of the flat plate heat pipe of the present invention;

FIG. 11 is a fifth overlapping structure of the flat heat pipe according to the present invention;

FIG. 12 shows a sixth overlapping structure of the flat heat pipe according to the present invention;

fig. 13 is a schematic view of the overall structure of the circuit board according to the second embodiment of the present invention;

wherein, 1, a flat heat pipe; 1-1, a shell; 1-1-1, a lower cover plate; 1-1-2, an upper cover plate; 1-2, a wick; 1-2-1, a liquid absorption core column; 1-3, a support column; 1-4, a steam cavity; 1-5, a lap joint structure; 1-6, slot position; 2. a thermally conductive insulating layer; 3. a solder resist layer; 4. a conductive layer; 4-1, conductive holes; 5. an electronic component; 6. semi-curing the insulating sheet; 7. a heat-conducting column; 8. a frame; 8-1, frame hole positions; 8-2, frame slot positions; 9. a copper plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1, the present invention provides a structure for directly integrating a circuit board on a surface of a flat heat pipe, including a flat heat pipe 1, a heat conducting insulating layer 2, a solder resist layer 3, a conductive layer 4, and an electronic component 5. There may be many electronic components 5 connected to the conductive layer 4, only one of which is shown in fig. 1 as an example.

As shown in fig. 2 and fig. 3, the internal structure of the flat heat pipe 1 includes a shell 1-1, a wick 1-2, a wick column 1-2-1, a support column 1-3, a vapor chamber 1-4, and a lap joint structure 1-5. The shell is formed by welding a lower cover plate 1-1-1 and an upper cover plate 1-1-2. A plurality of lap joint structures 1-5 may be provided around the upper cover plate 1-1-2, being integral with the upper cover plate 1-1-2. The liquid absorption core 1-2 is mainly arranged on the inner side wall surface corresponding to the surface of the shell 1-1, which is attached with the heat conduction insulating layer 2, the electronic component 5 and the like. Taking fig. 1 as an example, when electronic component 5 and the like are attached to the upper surface of flat heat pipe 1, wick 1-2 is provided on the upper wall surface of the inner wall surface of case 1-1. The liquid absorption core column 1-2-1 can be made of the same material as the liquid absorption core column 1-2, and mainly plays a role in promoting the backflow of working liquid; if the flat heat pipe is used along with gravity, the liquid absorption core column can be omitted. Taking fig. 1 as an example, the gravity direction is vertical downward, the electronic component 5 is on the upper surface of the flat heat pipe 1, and at this time, the flat heat pipe 1 is used against gravity. The flat heat pipe 1 can be divided into an evaporation end and a condensation end in the working process, the evaporation end is the surface paved with circuits and electronic components 5, and the exposed surface (or the surface attached to the fins and the liquid cooling plate) is the condensation end. The heat of the electronic component 5 is conducted to the liquid absorption core, so that the working liquid in the liquid absorption core at the evaporation end is quickly evaporated to be steam, and the steam can flow back to the liquid absorption core (i.e. the evaporation end) on the upper wall surface of the inner wall of the shell under the capillary action of the liquid absorption core and the liquid absorption core column after being condensed on the wall surface (i.e. the condensation end) of the shell on the other side.

As shown in fig. 4, the present invention can be developed into a multilayer circuit board, with conductive layers 4 separated by semi-cured insulating sheets 6. The different conductive layers 4 may be connected by conductive vias 4-1. If the heating power of the electronic component 5 is high, a heat-conducting column 7 can be further arranged, and heat can be conducted to the flat heat pipe 1 through the heat-conducting column. Further, the two side surfaces of the flat heat pipe can be designed similarly. It should be noted that fig. 3 is only an illustration, and the number and the spacing of the layers, the position and the structure of the conductive holes 4-1, the size of the conductive copper pillars, etc. can be adjusted according to the functional requirements of the circuit board.

The invention provides a substrate processing and splicing method suitable for large-scale production of the circuit board, which comprises two process schemes:

according to the first scheme, a flat heat pipe is directly used as a substrate to be integrally processed with a conducting layer, an electronic component and the like, and the method specifically comprises the following steps:

(1) Designing a lap joint structure on the periphery of a flat heat pipe with a heat dissipation structure; (2) Providing a corresponding frame, wherein a plurality of frame hole sites are formed in the frame, and each frame hole site is used for correspondingly placing a flat heat pipe; a frame slot position corresponding to the lap joint structure on the periphery of the flat heat pipe is designed on the side wall of the frame hole position; (3) A plurality of flat heat pipes 1 are fixed on the frame hole positions of the frame by correspondingly welding the flat heat pipe lap joint structures and the frame groove positions of the frame 8; (4) The flat heat pipes and the frame form a whole substrate, and the leveling process avoids the micro-protrusion of the surface. (5) Attaching a heat conduction insulating layer on the surface of the substrate for subsequent processing of the circuit board; (6) The surface of the substrate is bonded with a conducting layer, a solder mask layer, an electronic component and the like to finish the preprocessing of the circuit board; (7) And cutting the preprocessed circuit board, and removing the frame 8 part to obtain a plurality of circuit boards integrated with the base plate with the heat dissipation structure. (8) The heat-radiating substrate (namely the flat heat pipe) realizes the function of efficient heat conduction of the flat heat pipe through the processes of liquid injection, vacuum pumping, degassing, sealing and the like.

As shown in FIG. 5, the thickness of the frame 8 is the same as that of the flat heat pipe, a plurality of frame hole sites 8-1 are provided, and the shape of the frame hole sites 8-1 is the same as that of the flat heat pipe 1. The periphery of the frame hole site 8-1 is provided with a plurality of frame slots 8-2, and the shapes and the number of the frame slots correspond to those of the flat heat pipe lap joint structures 1-5. A flat heat pipe can be correspondingly placed in each frame hole site 8-1, and the lap joint structure of the flat heat pipes can be clamped on the frame groove sites 8-2. Preferably, the lap joint structure and the frame groove can be further welded through resistance welding so as to be completely fixed. Therefore, the plurality of flat heat pipes and the frame can form a whole large substrate. Attaching a heat conduction insulating layer and a printed circuit on the whole substrate to obtain a circuit board integrated with the efficient heat dissipation substrate; and cutting the frame to obtain a plurality of circuit boards integrated with the high-efficiency heat dissipation substrate. And finally, the efficient heat conduction function of the flat heat pipe is realized through the processes of liquid injection, vacuum pumping, degassing, sealing and the like.

As shown in fig. 6, the present invention can also adopt a borderless form, i.e. several flat heat pipes 1 are directly overlapped with each other. One flat heat pipe 1 is provided with a lap joint structure 1-5, and the adjacent flat heat pipe 1 can be provided with a groove position 1-6. Like a jigsaw puzzle, a plurality of flat heat pipes 1 can be spliced into a whole large substrate.

The design of the lap joint structures 1-5 and the corresponding slot shapes is various, and fig. 7, fig. 8, fig. 9, fig. 10, fig. 11 and fig. 12 illustrate several types, one end of each of which can be a rectangular structure, and the other end of each of which can be a rectangular, circular, oval, triangular or trapezoidal enlarged head structure, the structures at the two ends are integrally formed into a complete lap joint structure 1-5, and the slot positions are matched with the lap joint structures in shape. It should be noted that the key point of the present invention is that a plurality of flat heat pipes are spliced into a substrate of a whole circuit board, so as to facilitate the mass production of the circuit board, and the specific shape of the lap joint structure belongs to the derived design and shall all belong to the protection scope of the present invention.

The embodiment of the present invention is not limited to the first embodiment, and other embodiments, such as the second embodiment shown below, may also be adopted.

In the second scheme, the copper plate is used as a first substrate to be integrally processed with the conducting layer, the electronic component and the like, and then the flat heat pipe is used as a second substrate to be combined, and the second scheme specifically comprises the following steps:

(2) Providing a corresponding frame, wherein the frame material is the same as that of the flat heat pipe shell, a plurality of frame hole sites are formed in the frame, and each frame hole site is used for correspondingly placing one flat heat pipe; a frame slot position corresponding to the lap joint structure on the periphery of the flat heat pipe is designed on the side wall of the frame hole position;

(3) The flat heat pipe realizes the function of high-efficiency heat conduction through the processes of liquid injection, vacuum pumping, degassing, sealing and the like.

(5) The copper plate 9 is used as a first substrate, procedures such as a conducting layer, a solder mask layer, an electronic component and the like are attached to the surface of the copper plate, preprocessing of the circuit board is completed, and a printed circuit on the surface of the substrate can refer to the process of a traditional circuit board, and the process is roughly as follows: (i) And pressing the copper foil on the other side of the heat conduction insulating layer, and attaching a photosensitive film. (ii) And irradiating the photosensitive film on the copper foil by using a UV lamp, curing the photosensitive film under the light-transmitting film, and curing the photosensitive film under the light-tight film. The copper foil covered under the cured photosensitive film is the required circuit board layout circuit. (iii) The photosensitive film which is not cured is cleaned to expose the copper foil portion. (iv) The copper foil is removed by chemical etching, and then a solder resist is attached. (v) Finally tearing off the photosensitive film to expose the conductive circuit, namely the conductive layer;

(6) The copper plate 9 is a first substrate, one side of the structure without a conductive layer and the like is attached to a second substrate, namely a flat heat pipe, and the two substrates are welded through low-temperature soldering paste or bonded through high-strength heat-conducting silicone grease.

(7) After cutting, the frame portion of the second substrate and the redundant portion of the first substrate are removed, and a plurality of circuit boards integrated with the substrate having the heat dissipation structure are obtained, and the structure of which is shown in fig. 13.

In the description of the present invention, it should be noted that the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. A substrate splicing method of a circuit board is characterized by comprising the following steps: the method comprises the following steps:

(2) Providing a corresponding frame, wherein a plurality of frame hole sites are formed in the frame, and each frame hole site is used for correspondingly placing a flat heat pipe; a frame groove position corresponding to the lap joint structure on the periphery of the flat heat pipe is designed on the side wall of the frame hole position;

(3) A plurality of flat heat pipes are fixed on the hole positions of the frame by correspondingly welding the flat heat pipe lap joint structures and the frame grooves;

(4) A plurality of flat heat pipes and a frame form a whole substrate, and the surface of the substrate is leveled by pressure equipment;

(5) Attaching a heat conduction insulating layer to the surface of the substrate in the step (4) for subsequent circuit board processing;

(6) The side, which is attached with the heat-conducting insulating layer, of the surface of the substrate is subjected to procedures of attaching a conducting layer, a solder mask layer, electronic components and the like, so that preprocessing of the circuit board is completed;

(7) Cutting the preprocessed circuit board, and removing the frame part to obtain a plurality of circuit boards integrated with the substrate with the heat dissipation structure;

(8) The flat heat pipe of the circuit board realizes the heat conduction function of the flat heat pipe through the processes of liquid injection, vacuum pumping, degassing, sealing and the like.

2. The method for splicing substrates of circuit boards according to claim 1, wherein: the substrate comprises a first substrate and a second substrate, and a copper plate is used as the first substrate; in the step (4), the heat conduction function of the flat heat pipes is realized through the processes of liquid injection, vacuum pumping, degassing, sealing and the like of the flat heat pipes, then the flat heat pipes and a frame form a whole second substrate, and the surface of the second substrate is leveled through pressure equipment;

in the step (5), a heat conduction insulating layer is attached to the surface of the first substrate in the step (4) and is used for subsequent circuit board processing;

in the step (6), the side, which is attached with the heat-conducting insulating layer, of the surface of the first substrate is subjected to processes of attaching a conducting layer, a solder mask layer, an electronic component and the like, and the side, which is far away from the heat-conducting insulating layer, of the first substrate is fixedly attached with the second substrate to finish preprocessing of the circuit board;

and (7) cutting the preprocessed circuit board, and removing the frame part of the second substrate and the redundant part of the first substrate to obtain a plurality of circuit boards integrated with the substrate with the heat dissipation structure.

3. The method for splicing substrates of circuit boards according to claim 1, wherein: the flat heat pipe comprises a shell, the lap joint structure is arranged on the periphery of the shell and integrally formed with an upper cover plate of the shell or a lower cover plate of the shell, and the upper cover plate and the lower cover plate of the shell are welded through diffusion welding or brazing.

4. The method for splicing substrates of circuit boards according to claim 3, wherein: support columns are fixedly connected between the upper cover plate and the lower cover plate of the shell, and a steam cavity is formed between the support columns; the heat dissipation structure comprises a liquid absorption core and working liquid filled in the steam cavity, and the liquid absorption core is fixedly attached to the inner wall of one side, provided with the electronic component, of the flat heat pipe.

5. The method for splicing substrates of circuit boards according to claim 4, wherein: and a liquid suction core column is connected between the liquid suction core and the inner wall of one side of the flat heat pipe, which is far away from the electronic component.

6. The method for substrate splicing of circuit boards according to claim 3, wherein: the shell is made of copper, aluminum, stainless steel or ceramic.

7. The method for splicing substrates of circuit boards according to claim 4, wherein: the liquid absorption core is made of one or a combination of a plurality of sintered copper powder, copper wire meshes, grooves, foam copper, micro-cylinders and surface micro-nano structures.

8. The method for splicing substrates of circuit boards according to claim 1, wherein: the heat conduction insulating layer is provided with a plurality of conductive layers, and the solder mask layer and the conductive layer positioned on the outermost layer are arranged at fixed intervals; the adjacent two conductive layers are separated by a semi-solidified insulating sheet; guide holes are formed in the positions of the conducting layers, and different conducting layers can be connected through the guide holes.

9. The method for splicing substrates of circuit boards according to claim 1, wherein: and a heat-conducting column is fixedly connected between the electronic component and the heat-conducting insulating layer.