Printed circuit board and method for preparing the same

Abstract

The present invention discloses a printed circuit board and a method for preparing the same, wherein the printed circuit board comprises: a first substrate, wherein at least one conductive hole is provided on the first substrate, wherein the conductive hole is filled with a filler formed by curing a conductive slurry; a second substrate, wherein one side of the second substrate is bonded to one side of the first substrate, and at least one groove is formed on the side of the second substrate bonded to the first substrate, and the at least one groove extends to the edge of the printed circuit board to form at least one flow channel; at least one component, wherein the component is electrically connected to the side of the at least one conductive hole away from the second substrate; wherein the at least one conductive hole is respectively provided corresponding to the at least one flow channel. Through the above method, the present invention can improve the heat dissipation effect and efficiency of the printed circuit board.

Description

Technical Field

[0001] The invention is applied to the technical field of printed circuit boards, in particular to printed circuit boards and a preparation method thereof. Background Art

[0002] PCB (Printed Circuit Board), also known as printed circuit board or printed circuit board, is an important electronic component with wide applications. It is the support body of electronic components and also the carrier of electrical connection of electronic components.

[0003] At present, with the accelerating trend of miniaturization and high density of electronic products, the number and density of components soldered on printed circuit boards have increased significantly, resulting in the continuous increase in the power of the entire printed circuit board and obvious heat radiation, which puts high demands on the thermal conductivity and heat dissipation of the printed circuit board.

[0004] Traditional solutions often press printed circuit boards with copper or aluminum substrates, and the heat generated by components is transferred to the copper or aluminum substrate with high thermal conductivity through the printed circuit board to improve the heat dissipation efficiency. However, the metal substrate of the solution is heavy and it is difficult to meet the requirements of lightweight. At the same time, the heat needs to pass through the printed circuit board during the heat dissipation process, which will greatly affect its heat dissipation efficiency. Summary of the invention

[0005] The invention provides a printed circuit board and a preparation method thereof, so as to solve the problem of low heat dissipation efficiency of the printed circuit board existing in the prior art.

[0006] To solve the above technical problems, the present invention provides a printed circuit board, comprising: a first substrate, on which at least one conductive hole is arranged, wherein the conductive hole is filled with a filler formed by curing a conductive slurry; a second substrate, wherein one side of the second substrate is bonded to one side of the first substrate, and at least one groove is formed on the side of the second substrate bonded to the first substrate, and the at least one groove extends to the edge of the printed circuit board respectively to form at least one flow channel; at least one component, which is electrically connected to the side of the at least one conductive hole away from the second substrate; wherein the at least one conductive hole is respectively arranged corresponding to the at least one flow channel.

[0007] The bottom and the side wall of the flow channel are respectively bonded with a first protective layer; and a second protective layer is bonded with a position corresponding to the flow channel on a side of the first substrate close to the second substrate.

[0008] Wherein, at least one flow channel comprises a main flow channel, an outlet end and an inlet end which are interconnected; wherein the outlet end and the inlet end are respectively located at the edge of the second substrate and / or the first substrate.

[0009] Among them, a pipeline is buried in at least one flow channel; the pipeline runs through the inlet end, the main flow channel and the outlet end of the corresponding flow channel in sequence.

[0010] Wherein, one end of at least one conductive hole away from the flow channel is electrically connected to at least one component through welding or wires.

[0011] Wherein, a covering layer is formed on a side of at least one conductive hole close to the flow channel.

[0012] A support plate is formed on the side of the second substrate away from the first substrate; the support plate includes a support layer and a connecting layer, one side of the connecting layer is bonded to the side of the second substrate away from the first substrate; the other side of the connecting layer is bonded to one side of the support layer.

[0013] To solve the above technical problems, the present invention provides a method for preparing a printed circuit board, comprising: drilling a first plate to obtain at least one hole, filling a conductive slurry into the at least one hole and curing the hole to form at least one conductive hole on the first plate to obtain a first substrate; controlling the depth of one side of a second plate based on the position of the conductive hole to prepare at least one groove on one side of the second plate to obtain a second substrate, wherein the at least one groove extends to the edge of the printed circuit board relative to each other to form at least one flow channel; fixing the side of the second substrate where the flow channel is formed to the first substrate; electrically connecting at least one component to the side of the at least one conductive hole away from the second substrate to form a printed circuit board.

[0014] Among them, the step of fixedly connecting the side of the second substrate formed with the flow channel to the first substrate includes: stacking the first substrate, the semi-cured sheet and the second substrate in sequence, and pressing the stacked first substrate, the semi-cured sheet and the second substrate so that the side of the second substrate formed with the flow channel is fixedly connected to the first substrate.

[0015] The step of fixing the side of the second substrate with the flow channel formed thereon to the first substrate comprises: fixing the side of the second substrate with the flow channel formed thereon to the first substrate by welding, nut fixing or adhesive bonding.

[0016] The beneficial effects of the present invention are as follows: Different from the prior art, the printed circuit board of the present invention is provided with at least one flow channel inside the printed circuit board, so that when the printed circuit board is working, the cooling liquid flows through the at least one flow channel, thereby taking away the heat generated when the printed circuit board is working, thereby improving the heat dissipation efficiency of the printed circuit board. In addition, the present invention also provides conductive holes corresponding to the flow channel in the board and formed after the conductive slurry is solidified, so that the heat generated by the components is longitudinally conducted to the flow channel through the conductive holes filled with metal substances, further accelerating the heat dissipation efficiency of the components, further improving the heat dissipation efficiency of the printed circuit board, improving the reliability of the printed circuit board, and extending the service life of the components and the printed circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of an embodiment of a printed circuit board of the present invention;

[0018] Figure 2 yes Figure 1 A schematic diagram of the top view of the printed circuit board of the embodiment;

[0019] Figure 3 It is a schematic flow chart of an embodiment of a method for preparing a printed circuit board of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] See also Figure 1-2 , Figure 1 It is a schematic diagram of the cross-sectional structure of an embodiment of a printed circuit board of the present invention. Figure 2 yes Figure 1 Schematic diagram of the top view of the printed circuit board structure of the embodiment.

[0024] The printed circuit board 100 of this embodiment includes: a first substrate 110, at least one component 130, and a second substrate 120. One side of the second substrate 120 is laminated to one side of the first substrate 110.

[0025] At least one conductive hole 114 is provided on the first substrate 110, wherein the conductive holes 114 are respectively filled with fillers formed by curing the conductive slurry. Specifically, the conductive holes 114 can be filled with the fillers formed by curing the conductive slurry to achieve electrical connection. The conductive hole 114 can include a conductive blind hole or a conductive through hole, wherein the conductive through hole is a conductive through hole provided on the first substrate 110.

[0026] The conductive paste of this embodiment may include copper paste, silver paste or other metal pastes. Furthermore, the conductive paste may also include a mixture of any metal paste and resin, etc. The specific type of the conductive paste is not limited here.

[0027] The at least one component 130 is electrically connected to the at least one conductive via 114 . Specifically, the at least one component 130 may be electrically connected to a side of the at least one conductive via 114 away from the second substrate 120 .

[0028] The second substrate 120, wherein at least one groove is formed on the side where the second substrate 120 is bonded to the first substrate 110, and the at least one groove extends to the edge of the printed circuit board 100 to form at least one flow channel 124. The flow channel 124 can be used to carry a coolant, and the coolant is poured into one side of the flow channel 124 corresponding to the edge of the printed circuit board 100, so that the coolant flows in the flow channel 124 in the printed circuit board 100, and finally flows out from the edge of the printed circuit board 100 corresponding to the other side of the flow channel 124, thereby taking away the heat of the printed circuit board 100, thereby improving the heat dissipation efficiency of the printed circuit board 100. The coolant can include cooling water, glycerin, ethanol and other coolants.

[0029] Among them, at least one conductive hole 114 on the first substrate 110 is respectively arranged corresponding to at least one flow channel 124 in the second substrate 120, so that when the component 130 needs to dissipate heat, the heat can be directly and longitudinally conducted to the corresponding flow channel 124 through the corresponding conductive hole 114, thereby increasing the longitudinal thermal conductivity of the entire printed circuit board 100. Among them, since the conductive hole 114 of this embodiment is filled with a filler formed by curing the conductive slurry, that is, the entire conductive hole 114 is filled with a metal material with high thermal conductivity, therefore, the conductive hole 114 can further improve the heat dissipation efficiency of further conducting the heat generated by the component 130 to the flow channel 124, thereby further improving the heat dissipation efficiency of the entire printed circuit board 100 on the basis of the flow channel 124.

[0030] Since the conductive holes 114 of the present embodiment are filled with fillers formed by curing the conductive slurry, that is, the conductive holes 114 are filled with the cured conductive slurry without any other fillers, the conductive holes 114 of the present embodiment are able to further improve the conductive and thermal conductivity of the conductive holes 114 through the cured conductive slurry compared to conductive holes prepared by other methods such as resin plugging, ink plugging or electroplating filling.

[0031] Through the above structure, the printed circuit board of this embodiment is provided with at least one flow channel inside the printed circuit board, so that when the printed circuit board is working, the cooling liquid flows through the at least one flow channel, thereby taking away the heat generated when the printed circuit board is working, thereby improving the heat dissipation efficiency of the printed circuit board. In addition, this embodiment also provides conductive holes corresponding to the flow channel and formed after the conductive slurry is solidified in the board, so that the heat generated by the components is longitudinally conducted to the flow channel through the conductive holes filled with metal substances, further accelerating the heat dissipation efficiency of the components, further improving the heat dissipation efficiency of the printed circuit board, improving the reliability of the printed circuit board, and extending the service life of the components and the printed circuit board.

[0032] In other embodiments, the first substrate 110 further includes at least one first conductive layer 112 and at least one first insulating layer 111. The at least one first conductive layer 112 and the at least one first insulating layer 111 are sequentially stacked and overlapped to form the first substrate 110. The first insulating layer 111 may be a dielectric layer, which may include one or more of epoxy resin, polyimide, BT, ABF, and ceramic-based.

[0033] In a specific application scenario, the first substrate 110 may further include a conductive blind hole or other conductive structure, and the conductive blind hole or other conductive structure may connect any first conductive layer 112. The specific structure of the first substrate 110 may be set based on actual needs and is not limited here.

[0034] In other embodiments, the second substrate 120 further includes at least one second conductive layer 122 and at least one second insulating layer 121. The at least one second conductive layer 122 and the at least one second insulating layer 121 are sequentially stacked and overlapped to form the second substrate 120. The second insulating layer 121 may also be a dielectric layer, which may include one or more of epoxy resin, polyimide, BT, ABF, and ceramic-based.

[0035] In a specific application scenario, the second substrate 120 may further include a conductive blind hole or other conductive structure, and the conductive blind hole or other conductive structure may connect any second conductive layer 122. The specific structure of the second substrate 120 may be set based on actual needs and is not limited here.

[0036] In other embodiments, other conductive blind holes, conductive through holes or embedded components may be further provided on the printed circuit board 100 , which may be specifically provided based on actual needs and are not limited here.

[0037] In other embodiments, the bottom and side walls of the flow channel 124 are respectively provided with a first protective layer 125, and a second protective layer 113 is provided at a position corresponding to the flow channel 124 on a side of the first substrate 110 close to the second substrate 120, so that all surfaces of the flow channel 124 are surrounded by the first protective layer 125 and the second protective layer 113, so that when the coolant flows in the flow channel 124, the coolant is prevented from corroding the internal structure of the printed circuit board 100, thereby ensuring the normal circulation of the coolant in the flow channel 124 and improving the stability and reliability of the printed circuit board 100.

[0038] The first protective layer 125 and the second protective layer 113 may include an anti-oxidation layer and / or an anti-corrosion layer, which may specifically be an inactive metal layer, a gold layer, a triple-proof adhesive layer, etc., and the specific type is not limited here.

[0039] In other embodiments, at least one flow channel 124 includes a main flow channel 1242, an outlet end 1243 and an inlet end 1241 that are interconnected; wherein the outlet end 1243 and the inlet end 1241 are respectively located at the edges of the second substrate 120 and / or the first substrate 110 to connect to the outside of the printed circuit board 100, thereby receiving and releasing the cooling liquid.

[0040] In a specific application scenario, the outlet end 1243 and the inlet end 1241 may both be located at the edge of the second substrate 120. In a specific application scenario, the outlet end 1243 and the inlet end 1241 may both be located at the edge of the first substrate 110. In a specific application scenario, the outlet end 1243 and the inlet end 1241 may be located at the edge of the second substrate 120 and the first substrate 110, respectively.

[0041] At least one flow channel 124 may be disposed corresponding to the component 130 , thereby facilitating longitudinal heat conduction through the conductive via 114 disposed corresponding to the flow channel 124 and electrically connected to the component 130 .

[0042] In other embodiments, a pipe (not shown in the figure) may be buried in at least one flow channel 124, and the pipe sequentially passes through the inlet end 1241, the main flow channel 1242 and the outlet end 1243 of the corresponding flow channel 124, so that the coolant flows through the pipe. The pipe buried in the flow channel 124 can improve the ability of the flow channel 124 to resist the pressure of the coolant, thereby further isolating the coolant from the inside of the printed circuit board 100, and improving the reliability and service life of the flow channel 124, so that the flow channel 124 can cope with a larger coolant pressure, and ensure the quality of the printed circuit board 100.

[0043] In other embodiments, the corner position of the flow channel 124 can be set to an arc shape to prevent the water hammer effect and improve the reliability and service life of the flow channel 124. The size of the flow channel 124 can be determined based on the heat dissipation power of the printed circuit board 100, the material type design and the internal structure of the printed circuit board 100, and is not specifically limited here.

[0044] In other embodiments, one end of at least one conductive hole 114 away from the flow channel 124 is electrically connected to at least one component 130 through welding or wire. The component 130 may be electrically connected to the at least one conductive hole 114. The at least one component 130 may be arranged corresponding to the at least one conductive hole 114, so as to conduct heat to the at least one component 130 through the at least one conductive hole 114.

[0045] In a specific application scenario, the component 130 includes a component body 132 and at least one solder point 131 . The component 130 is soldered to at least one conductive hole 114 through the at least one solder point 131 to achieve fixation and electrical connection of the component 130 .

[0046] The component 130 , the conductive hole 114 and the flow channel 124 may be arranged correspondingly on the same straight line, so that the heat generated by the component 130 is directly transferred to the flow channel 124 through the conductive hole 114 , thereby improving the heat dissipation effect of the conductive hole 114 .

[0047] The specific types of components 130 may include chips, power components, TR components or other components, and the specific types of components 130 may be set based on actual needs and are not limited here.

[0048] In other embodiments, a covering layer 115 is formed on a side of at least one conductive hole 114 close to the flow channel 124 , so that the covering layer 115 prevents the coolant in the flow channel 124 from attacking the conductive hole 114 .

[0049] The covering layer 115 may include a conductive metal layer, so that it can support and cover the side of the conductive hole 114 close to the flow channel 124 while realizing the circuit function of the printed circuit board 100. The covering layer 115 needs to completely cover the side of each conductive hole 114 close to the flow channel 124 while realizing the circuit function, so as to prevent the coolant in the flow channel 124 from attacking the conductive hole 114.

[0050] In other embodiments, a support plate (not marked in the figure) is formed on a side of the second substrate 120 away from the first substrate 110 .

[0051] The support plate includes a support layer 123 and a connecting layer (not marked in the figure), one side of the connecting layer is bonded to the side of the second substrate 120 away from the first substrate 110, and the other side of the connecting layer is bonded to one side of the support layer 123.

[0052] The connection layer and the second insulating layer 121 of the second substrate 120 may be the same dielectric layer and may be made of the same material, so that after the support plate is disposed on a side of the second substrate 120 away from the first substrate 110 , they are bonded to each other.

[0053] The support layer 123 may include a conductive metal layer, so that it can support the flow channel 124 while realizing the circuit function of the printed circuit board 100 to reduce the occurrence of collapse of the flow channel 124 .

[0054] Specifically, the thickness of the support layer 123 is in the range of 0.75 mm or more. The support layer 123 in this range can support the flow channel 124 and the flow of the coolant in the flow channel 124 .

[0055] See also Figure 3 , Figure 3 It is a schematic flow chart of an embodiment of a method for preparing a printed circuit board of the present invention.

[0056] Step S11: drilling the first plate to obtain at least one hole, and filling the at least one hole with a conductive slurry and curing the slurry to form at least one conductive hole on the first plate to obtain a first substrate.

[0057] A first board is obtained, wherein the first board may include a single-layer circuit board and a multi-layer circuit board.

[0058] The first plate is drilled to obtain at least one hole. The at least one hole may include a blind hole and / or a through hole. In a specific application scenario, the first plate may be drilled to obtain at least one hole by CO2 laser, UV laser, mechanical drilling, or water jet cutting.

[0059] After drilling at least one hole, fill the at least one hole with conductive slurry and solidify it to form at least one conductive hole on the first plate to obtain a first substrate. The method of forming at least one conductive hole in this step cannot be performed by electroplating. Due to the surface tension of the electroplating solution, the electroplating solution cannot adapt to holes of different depths and diameters, and electroplating voids are easily generated. However, plugging the hole with conductive slurry can perfectly avoid the occurrence of electroplating voids. Improve the electrical and thermal conductivity of the conductive hole.

[0060] Step S12: Based on the position of the conductive hole, the depth of one side of the second plate is controlled to prepare at least one groove on one side of the second plate to obtain a second substrate, wherein at least one groove extends to the edge of the printed circuit board respectively to form at least one flow channel.

[0061] A second board is obtained, wherein the second board may include a single-layer circuit board and a multi-layer circuit board.

[0062] The depth of one side of the second plate is controlled based on the position of the conductive hole, so as to prepare at least one groove on one side of the second plate to obtain a second substrate, wherein the at least one groove extends relatively to the edge of the printed circuit board to form at least one flow channel, and the at least one conductive hole is respectively arranged corresponding to the at least one flow channel. Thus, heat can be directly conducted to the flow channel through the conductive hole, thereby improving heat dissipation efficiency.

[0063] In a specific application scenario, at least one groove can extend to the edge of the second plate to form at least one flow channel. In a specific application scenario, at least one groove can extend to the edge of the first plate to form at least one flow channel, wherein, at this time, the first plate needs to be depth-controlled accordingly to prepare the inlet / outlet of the flow channel on the first plate.

[0064] Step S13: fixing and connecting the side of the second substrate where the flow channel is formed to the first substrate.

[0065] The side of the second substrate where the flow channel is formed is fixedly connected to the first substrate, so that the side of the second substrate where the flow channel is formed is bonded to the first substrate, thereby forming a plate component.

[0066] Step S14: electrically connecting at least one component to a side of at least one conductive hole away from the second substrate to form a printed circuit board.

[0067] At least one component is electrically connected to a side of at least one conductive hole away from the second substrate to form a printed circuit board, wherein one component can be electrically connected to at least one conductive hole.

[0068] Through the above steps, the method for preparing the printed circuit board of this embodiment is prepared by splitting the board into a first substrate and a second substrate, so as to prepare at least one flow channel on the second substrate, so that after the first substrate and the second substrate are fixedly connected, at least one flow channel is buried inside the printed circuit board, so that heat is taken away from the inside of the printed circuit board through the flow channel, thereby improving the heat dissipation efficiency of the printed circuit board. In addition, this embodiment also controls the depth of one side of the second board based on the position of the conductive hole, thereby forming a flow channel, so that the conductive hole corresponds to the flow channel, and then the heat generated by the components is longitudinally conducted to the flow channel through the conductive hole of the metal material filled with the conductive slurry, further accelerating the heat dissipation efficiency of the components, further improving the heat dissipation efficiency of the printed circuit board, improving the reliability of the printed circuit board, and extending the service life of the components and the printed circuit board.

[0069] In other embodiments, the installation of components, the setting of conductive holes and the position of flow channels can be adjusted accordingly based on the settings of each other, so as to achieve the corresponding settings of components, conductive holes and flow channels, so that the conductive holes can directly transfer the heat of components to the flow channels for heat dissipation, thereby improving the heat dissipation efficiency of components.

[0070] In other embodiments, the step of fixing the side of the second substrate with the flow channel formed thereon to be connected to the first substrate in step S13 may further include: stacking the first substrate, the prepreg, and the second substrate in sequence, and pressing the stacked first substrate, the prepreg, and the second substrate together, thereby fixing the side of the second substrate with the flow channel formed thereon to be connected to the first substrate by melting the prepreg.

[0071] Among them, since the second substrate is pressed together with the first substrate on the side provided with the flow channel, in order to avoid excess resin from flowing into the groove during the pressing process of the prepreg and to ensure the bonding force between the panels, a prepreg with low fluidity can be selected for pressing, for example: EM370, Fr-28 and other prepregs.

[0072] In other embodiments, the step of fixing the side of the second substrate with the flow channel formed thereon to the first substrate in step S13 may also include: fixing the side of the second substrate with the flow channel formed thereon to the first substrate by welding, nut fixing or adhesive bonding, so that the side of the second substrate with the flow channel formed thereon is bonded to the first substrate to form a plate.

[0073] In other embodiments, after forming at least one conductive hole, a metal layer may be plated on a side of the at least one conductive hole close to the second substrate to form a covering layer on a side of the at least one conductive hole close to the second substrate, so as to completely cover a side of each conductive hole close to the flow channel while realizing the circuit function, so as to avoid the coolant in the flow channel attacking the conductive hole.

[0074] In other embodiments, after the depth of one side of the second plate is controlled and the flow channel is formed, the bottom and side walls of the flow channel are subjected to anti-oxidation and / or anti-corrosion treatment. Specifically, an inactive metal such as gold plating may be selected, or a three-proof adhesive may be applied for protection to form a protective layer to prevent the coolant from corroding the inside of the printed circuit board.

[0075] Among them, anti-oxidation and / or anti-corrosion treatment can also be performed at a position corresponding to the flow channel on the side of the first substrate close to the second substrate, so that after the first substrate is fixedly connected to the second substrate, a protective layer is also formed on the top of the flow channel, and then all surfaces of the entire flow channel are protected by the protective layer, thereby further improving the reliability of the flow channel.

[0076] The printed circuit board of the present invention uses liquid cooling to dissipate heat by processing the plate itself to form a flow channel cavity, rather than traditional metal heat conduction, which reduces the thickness and weight of the plate, realizes the miniaturization and lightness of the printed circuit board, and can improve the heat dissipation efficiency of the entire plate by cooling the heat through the flow channel that can be circulated continuously. The conductive holes correspond to the flow channels, and then the heat generated by the components is longitudinally conducted to the flow channels through the conductive holes of the metal material filled with conductive slurry, further accelerating the heat dissipation efficiency of the components, further improving the heat dissipation efficiency of the printed circuit board, improving the reliability of the printed circuit board, and extending the service life of the components and the printed circuit board.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A printed circuit board, characterized in that: The printed circuit board comprises: A first substrate, wherein at least one conductive hole is provided on the first substrate, wherein the conductive hole is filled with a filler formed by curing a conductive slurry; A second substrate, wherein one side of the second substrate is fitted with one side of the first substrate via a nut, at least one groove is formed on the side of the second substrate fitted with the first substrate, and the at least one groove extends to the edge of the printed circuit board to form at least one flow channel; at least one component, the component being electrically connected to a side of at least one of the conductive holes away from the second substrate; Wherein, the at least one conductive hole is respectively arranged corresponding to at least one of the flow channels; A pipe is buried in the flow channel, and the corner of the flow channel is arc-shaped. A support plate is formed on a side of the second substrate away from the first substrate.

2. The printed circuit board according to claim 1, characterized in that: The bottom and side wall of the flow channel are respectively provided with a first protective layer; A second protective layer is disposed on a side of the first substrate close to the second substrate at a position corresponding to the flow channel.

3. The printed circuit board according to claim 1, characterized in that: At least one of the flow channels includes a main flow channel, an outlet end and an inlet end that are interconnected; Wherein, the outlet end and the inlet end are respectively located at the edge of the second substrate and / or the first substrate.

4. The printed circuit board according to claim 3, characterized in that: A pipeline is buried in at least one of the flow channels; The pipeline sequentially passes through the inlet end, the main flow channel and the outlet end of the corresponding flow channel.

5. The printed circuit board according to any one of claims 1 to 4, characterized in that: One end of at least one of the conductive holes away from the flow channel is electrically connected to at least one component through welding or wires.

6. The printed circuit board according to claim 5, characterized in that: A covering layer is formed on a side of at least one of the conductive holes close to the flow channel.

7. The printed circuit board according to claim 1, characterized in that: A support plate is formed on a side of the second substrate away from the first substrate; The support plate includes a support layer and a connection layer, and one side of the connection layer is bonded to a side of the second substrate away from the first substrate; The other side of the connecting layer is arranged in contact with one side of the supporting layer.

8. A method for preparing a printed circuit board, characterized in that: The method for preparing the printed circuit board comprises: Drilling the first plate to obtain at least one hole, and filling the at least one hole with a conductive slurry and curing the slurry to form at least one conductive hole on the first plate to obtain a first substrate; The depth of one side of the second plate is controlled based on the position of the conductive hole to prepare at least one groove on one side of the second plate to obtain a second substrate, wherein the at least one groove extends relatively to the edge of the printed circuit board to form at least one flow channel; Fixedly connecting the side of the second substrate where the flow channel is formed to the first substrate; Electrically connecting at least one component to a side of the at least one conductive hole away from the second substrate to form the printed circuit board; The step of fixing and connecting the side of the second substrate where the flow channel is formed to the first substrate comprises: The side of the second substrate where the flow channel is formed is fixedly connected to the first substrate by means of a nut; A pipe is buried in the flow channel, and the corner of the flow channel is arc-shaped. A support plate is formed on a side of the second substrate away from the first substrate.

9. The method for preparing a printed circuit board according to claim 8, characterized in that: The step of fixing and connecting the side of the second substrate where the flow channel is formed to the first substrate comprises: The first substrate, the prepreg, and the second substrate are stacked in sequence, and the stacked first substrate, the prepreg, and the second substrate are pressed together so that a side of the second substrate where the flow channel is formed is fixedly connected to the first substrate.

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