CN116406084A

CN116406084A - Preparation method of heat dissipation type circuit board and heat dissipation type circuit board

Info

Publication number: CN116406084A
Application number: CN202310223119.4A
Authority: CN
Inventors: 孙先成; 陈绪东; 周锋
Original assignee: Shennan Circuit Co Ltd
Current assignee: Shennan Circuit Co Ltd
Priority date: 2023-02-28
Filing date: 2023-02-28
Publication date: 2023-07-07

Abstract

The application discloses a preparation method of a heat dissipation type circuit board and the heat dissipation type circuit board, comprising the following steps: obtaining a plate to be treated; the plate to be treated comprises at least one dense radiating hole area, wherein the dense radiating hole area comprises a plurality of metalized through holes which are densely distributed; forming a depth control groove in each dense radiating hole area; electroplating the depth control groove; the electroplated depth control groove is used for accommodating the high-power device. According to the method, the plurality of metalized through holes densely distributed at the bottom of the deep groove are utilized to radiate the high-power device, so that the radiating efficiency can be improved under the condition of avoiding using a metal-based process, the preparation difficulty of the radiating type circuit board is reduced, and the preparation cost is further reduced.

Description

Preparation method of heat dissipation type circuit board and heat dissipation type circuit board

Technical Field

The application relates to the technical field of circuit board processing, in particular to a preparation method of a heat dissipation type circuit board and the heat dissipation type circuit board.

Background

With the development of 5G technology and microelectronic technology, PCB (Printed Circuit Board ) boards are gradually developed toward miniaturization and high density, and the size of high-power components/chips is also smaller, but the operation speed is faster, and correspondingly, the heat productivity of the components/chips is also larger. If the heat generated by the components/chips cannot be conducted rapidly, the performance of the components/chips is affected.

In the prior art, a local metal base embedding manner is generally used to improve the heat dissipation performance of the PCB, that is, the metal base is embedded in the area where the high-power device is located, so as to dissipate heat of the high-power device through the metal base.

However, the metal base needs to be purchased additionally, and the process of embedding the metal base or embedding the metal base is complicated, resulting in high manufacturing cost of the metal base PCB board.

Disclosure of Invention

The technical problem that this application mainly solves is to provide the preparation method and the heat dissipation type circuit board of heat dissipation type circuit board, can solve the higher problem of preparation cost that current heat dissipation type circuit board exists.

In order to solve the technical problems, a technical scheme adopted by the application is to provide a preparation method of a heat dissipation circuit board, which comprises the following steps: obtaining a plate to be treated; the plate to be treated comprises at least one dense radiating hole area, wherein the dense radiating hole area comprises a plurality of metalized through holes which are densely distributed; forming a depth control groove in each dense radiating hole area; electroplating the depth control groove; the electroplated depth control groove is used for accommodating the high-power device.

After the step of forming the depth control groove in each dense radiating hole area, the method comprises the following steps: forming a plurality of blind holes at the bottom of the depth control groove; electroplating the depth control groove to form a conductive layer at the bottom of the depth control groove, and further comprising: electroplating the blind holes to form a plurality of metallized holes.

Wherein, the step of forming a plurality of blind holes at the tank bottom of the depth control tank comprises the following steps: and processing a plurality of blind holes at the bottom of the depth control groove by using a laser ablation mode.

Wherein, the step of forming the depth control groove in each dense radiating hole area comprises the following steps: processing a depth control groove in each dense radiating hole area according to the preset depth and size; the size of the depth control groove is larger than that of the dense radiating hole area.

Wherein, the step of forming the depth control groove in each dense radiating hole area comprises the following steps: and processing the depth control groove in the dense radiating hole area by using a depth control groove milling mode.

Wherein, the step of obtaining the board to be processed comprises the following steps: obtaining a plate to be processed; wherein the plate to be processed is a multi-layer core plate obtained by lamination; drilling dense holes in at least one preset area of a plate to be processed to form a plurality of densely arranged through holes in the preset area; hole metallization is performed on the plurality of vias to form a plurality of metallized vias.

Wherein the step of hole metallizing the plurality of vias to form a plurality of metallized vias comprises: and filling resin or ink in the plurality of metalized through holes.

The step of drilling dense holes in at least one preset area of the plate to be processed to form a plurality of densely arranged through holes in the preset area comprises the following steps: and drilling dense holes in a preset area of the plate to be processed by using a mechanical drilling mode so as to form a plurality of through holes densely distributed in the preset area.

Wherein, the step of electroplating the depth control groove comprises the following steps: depositing metal on the bottom and side wall of the depth control groove to form a conductor film; electroplating the deep control groove with the conductor film to form a conductive layer at the groove bottom and the side wall.

In order to solve the technical problems, another technical scheme adopted by the application is to provide a heat dissipation type circuit board, wherein the heat dissipation type circuit board is manufactured by the manufacturing method of the heat dissipation type circuit board; the heat dissipation circuit board comprises at least one deep control groove, and a plurality of metalized through holes densely distributed are formed in the bottom of the deep control groove.

The beneficial effects of this application are: compared with the prior art, the preparation method of the heat dissipation type circuit board and the heat dissipation type circuit board are provided, the deep control groove is formed in the dense heat dissipation hole area of the board to be processed, electroplating is carried out on the deep control groove, the high-power device is accommodated in the deep control groove after electroplating, and the plurality of metalized through holes densely distributed at the bottom of the deep control groove can be utilized for dissipating heat of the high-power device, so that the heat dissipation efficiency is improved. Through the mode, the metal-based process can be prevented from being used for heat dissipation, so that the preparation difficulty of the heat dissipation type circuit board is reduced, and the preparation cost is further reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic flow chart of a first embodiment of a method for manufacturing a heat dissipation type circuit board according to the present application;

fig. 2 is a schematic flow chart of a second embodiment of a method for manufacturing a heat dissipation type circuit board according to the present application;

FIG. 3 is a schematic view of an embodiment of a board to be processed according to the present application;

FIG. 4 is a schematic view of another embodiment of a panel to be processed according to the present application;

FIG. 5 is a schematic view of the structure of an embodiment of a sheet material to be processed to form dense holes;

FIG. 6 is a schematic structural view of an embodiment of the board to be processed obtained in S23;

FIG. 7 is a schematic structural view of an embodiment of the board to be processed obtained in S24;

FIG. 8 is a schematic structural view of an embodiment of the board to be processed obtained in S25;

FIG. 9 is a top view of the bottom of the depth control slot of FIG. 8;

fig. 10 is a schematic structural diagram of an embodiment of the heat dissipation type circuit board of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, the "plurality" generally includes at least two, but does not exclude the case of at least one.

It should be understood that the term "and/or" as used herein is merely one relationship describing the association of the associated objects, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

It should be understood that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

In the prior art, a local metal base embedding manner is generally used to improve the heat dissipation performance of the PCB, that is, the metal base is embedded in the area where the high-power device is located, so as to dissipate heat of the high-power device through the metal base. However, the metal base needs to be purchased additionally, and the process of embedding the metal base or embedding the metal base is complicated, resulting in high manufacturing cost of the metal base PCB board.

Based on the above situation, the application provides the preparation method of the heat dissipation type circuit board and the heat dissipation type circuit board, which can solve the problem of higher preparation cost of the existing heat dissipation type circuit board.

The present application will be described in detail with reference to the drawings and embodiments.

Referring to fig. 1, fig. 1 is a schematic flow chart of a first embodiment of a method for manufacturing a heat dissipation circuit board according to the present application. In this embodiment, the preparation method includes:

s11: obtaining a plate to be treated; the plate to be processed comprises at least one dense radiating hole area, and the dense radiating hole area comprises a plurality of metalized through holes which are densely distributed.

In this embodiment, the pitch between the metallized through holes in the densely packed heat dissipating hole region is 0.4 to 0.5mm. Where pitch refers to the distance between the walls of adjacent metallized vias.

In this embodiment, the dense heat dissipation hole area is used for dissipating heat of a high-power device requiring heat dissipation, and the size of the dense heat dissipation hole area can be set based on the corresponding size of the high-power device requiring heat dissipation.

The number of the dense heat dissipation hole areas may be set based on the heat dissipation requirement of the circuit board, for example, 1, 2 or more high-power devices needing heat dissipation, and the number of the dense heat dissipation hole areas may be 1, 2 or more, which is not limited in this application.

S12: and forming a depth control groove in each dense radiating hole area.

In this embodiment, the size of the depth control groove is not smaller than the size of the dense heat dissipation hole region. Where dimensions refer to length and width only, and do not include depth.

It can be appreciated that the size of the depth control groove is not smaller than the size of the dense heat dissipation hole area, so that the bottom of the depth control groove completely covers the dense heat dissipation hole area.

In this embodiment, the depth of the depth control groove may be set based on the thickness of the high power device to be placed, which is not limited in this application.

S13: electroplating the depth control groove; the electroplated depth control groove is used for accommodating the high-power device.

The high-power device may be a component or a chip, which is not limited in this application.

It can be understood that the high-power device is accommodated in the deep control groove after electroplating, and the high-power device can be radiated by utilizing the plurality of metalized through holes densely distributed at the bottom of the deep control groove, so that the radiating efficiency is improved. Further, since the high power device is at least partially embedded in the board body, the thickness of the board can also be reduced without affecting heat dissipation.

Compared with the prior art, the high-power device in the deep control groove is radiated through the dense radiating hole area, and the metal base can be prevented from being pressed in the circuit board, so that the preparation difficulty of the radiating circuit board is reduced, and the preparation cost is further reduced.

Referring to fig. 2, fig. 2 is a schematic flow chart of a second embodiment of a method for manufacturing a heat dissipation circuit board according to the present application. In this embodiment, the preparation method includes:

s21: obtaining a plate to be processed; wherein the plate to be processed is a multi-layer core plate obtained by lamination.

In this embodiment, lamination refers to a method of bonding two or more layers of the same or different materials into a whole by heat and pressure with or without an adhesive. The core board is a copper-clad board, and the copper-clad board comprises a dielectric layer and a copper layer, wherein one side of the dielectric layer can be covered with the copper layer, and the other side of the dielectric layer can be covered with the copper layer.

In this embodiment, a copper layer is taken as an example of the double-sided copper-clad layer of the insulating layer of the copper-clad plate. Wherein, a PP sheet (prepreg) is arranged between the multi-layer core plates. Wherein, dielectric layer and PP layer are insulating layer.

The outermost layer of the plate to be processed can be a copper layer on the surface of the core plate, or can be copper foil pressed on the surface of the core plate through PP, and the application is not limited to the method.

Specifically, referring to fig. 3 and fig. 4, fig. 3 is a schematic structural diagram of an embodiment of a board to be processed according to the present application, and fig. 4 is a schematic structural diagram of another embodiment of the board to be processed according to the present application.

As shown in fig. 3, the board to be processed 100 includes a plurality of core boards 10, and prepregs 20 are disposed between adjacent core boards 10. The core board 10 includes a dielectric layer 101 and copper layers 102 provided on both side surfaces of the dielectric layer 101. The outermost surfaces of the sheet material 100 to be processed are copper layers 102 of the core 10.

As shown in fig. 4, the board to be processed 100 includes a plurality of core boards 10, and prepregs 20 are provided between adjacent core boards 10. The core board 10 includes a dielectric layer 101 and copper layers 102 provided on both side surfaces of the dielectric layer 101. The outermost surfaces of the board 100 to be processed are copper foils 30 laminated on the core board 10 through the prepreg 20.

S22: drilling dense holes in at least one preset area of the plate to be processed so as to form a plurality of through holes densely distributed in the preset area.

In this embodiment, the preset area is an area where the high-power device is mounted. Wherein, the liquid crystal display device comprises a liquid crystal display device, the number of preset regions may be set according to the number of high power devices to be mounted. For example, the number of the high power devices to be mounted is 1, 2 or more, and the number of the preset regions may be 1, 2 or more, which is not limited in this application.

In this embodiment, dense holes are drilled in a preset area of the plate to be processed by using a mechanical drilling mode, so that a plurality of through holes densely distributed in the preset area are formed. In other embodiments, the dense holes may also be formed by laser drilling, which is not limited in this application.

Wherein, the interval between the adjacent through holes is 0.4-0.5 mm.

Specifically, referring to fig. 5, fig. 5 is a schematic structural diagram of an embodiment of a plate to be processed for forming dense holes. The board 300 to be processed includes a plurality of core boards 10, and prepregs 20 are disposed between adjacent core boards 10. The core board 10 includes a dielectric layer 101 and copper layers 102 provided on both side surfaces of the dielectric layer 101. The outermost surfaces of the sheet 300 to be processed are copper layers 102 of the core 10. The plate 300 to be processed includes one dense hole area 40, and the dense hole area 40 includes a plurality of through holes 41 densely arranged.

S23: hole metallization is performed on the plurality of vias to form a plurality of metallized vias.

In this embodiment, when the board to be processed is subjected to laser drilling or mechanical drilling, and a plurality of through holes are drilled at the set positions of the board to be processed, the holes of the board to be processed may have residual drilling dirt such as resin slag and copper slag, so that the through holes also need to be subjected to dirt removing treatment to clean the through holes.

Further, the through holes on the plate to be processed are subjected to hole treatment. Wherein the porosification treatment comprises copper deposition treatment, black hole treatment or shadow treatment. The holes on the plate to be processed are subjected to hole treatment so as to cover a layer of conductive material on the hole wall or/and the hole bottom of the holes, thereby facilitating subsequent hole filling electroplating. Wherein, the black hole treatment refers to dip-coating fine graphite or carbon black paint (black hole liquid) on the hole wall or/and the hole bottom of the hole to form a conductive layer; the shadow treatment is to dip-coat the shadow liquid containing unique additives and conductive colloid substances on the hole walls or/and the hole bottoms of the holes to form conductive layers on the hole walls or/and the hole bottoms; copper deposition refers to chemical deposition of a thin layer of chemical copper on the walls and/or bottom of the holes to form a substrate for electroplating.

Further, electroplating is carried out on the plate to be processed so as to form a copper layer on the surface of the plate to be processed and the wall of the through holes, and then resin or printing ink is filled in the plurality of metalized through holes.

Specifically, referring to fig. 6, fig. 6 is a schematic structural diagram of an embodiment of the board to be processed obtained in S23. The board 400 to be treated comprises a plurality of core boards 10, and prepregs 20 are arranged between adjacent core boards 10. The core board 10 includes a dielectric layer 101 and copper layers 102 provided on both side surfaces of the dielectric layer 101. The outermost surfaces of the sheet 400 to be treated are all the conductive layers 60 formed by electroplating. The board 400 to be processed includes a dense hole heat dissipation area 50, and the dense hole heat dissipation area 50 includes a plurality of metallized through holes 51 densely arranged. Wherein, the side wall of the metallized through hole 51 forms a conductive copper layer 512, and the metallized through hole 51 is filled with an insulating material 511. Wherein the insulating material 511 may be resin or ink.

S24: and forming a depth control groove in each dense radiating hole area.

In this embodiment, the depth control groove is machined in the dense heat dissipation hole area by means of depth control milling.

And processing a depth control groove in each dense radiating hole area according to the preset depth and size. The size of the depth control groove is larger than that of the dense radiating hole area.

Specifically, referring to fig. 7, fig. 7 is a schematic structural diagram of an embodiment of the board to be processed obtained in S24. The board 500 to be treated includes a plurality of core boards 10, with prepregs 20 disposed between adjacent core boards 10. The core board 10 includes a dielectric layer 101 and copper layers 102 provided on both side surfaces of the dielectric layer 101. The outermost surfaces of the sheet 500 to be treated are all the conductive layers 60 formed by electroplating. The sheet 500 to be processed includes a depth control groove 70, and the bottom of the depth control groove 70 includes a plurality of metallized through holes 51 densely arranged.

S25: and forming a plurality of blind holes at the bottom of the depth control groove.

In the embodiment, a plurality of blind holes are processed at the bottom of the depth control groove by using a laser ablation mode.

The position of the blind hole can avoid the metalized through hole or not.

Specifically, referring to fig. 8 and 9, fig. 8 is a schematic structural diagram of an embodiment of the board to be processed obtained in S25, and fig. 9 is a top view of the bottom of the deep groove in fig. 8. The board 600 to be processed includes a plurality of core boards 10, and prepregs 20 are disposed between adjacent core boards 10. The core board 10 includes a dielectric layer 101 and copper layers 102 provided on both side surfaces of the dielectric layer 101. The outermost surfaces of the sheet 600 to be treated are all the conductive layers 60 formed by electroplating. The plate 600 to be processed comprises a depth control groove 70, and the bottom of the depth control groove 70 comprises a plurality of metallized through holes 51 which are densely distributed. The bottom of the depth control groove 70 is also provided with a plurality of blind holes 80, and the blind holes 80 and the metallized through holes 51 are staggered.

S26: electroplating the depth control groove; and electroplating the blind holes to form a plurality of metallized holes.

In the embodiment, metal is deposited on the bottom and the side wall of the depth control groove to form a conductor film, and then the depth control groove with the conductor film is electroplated to form a conductive layer on the bottom and the side wall of the depth control groove. Simultaneously, a plurality of blind holes are electroplated to form a plurality of metallized holes.

Wherein, the desmear treatment and the pore-forming treatment are carried out before the electroplating.

It can be understood that a plurality of blind holes are ablated on the bottom of the depth control groove, so that the surface area of the bottom of the groove can be increased, and the binding force between the copper layer and the bottom of the groove can be increased when copper is electroplated, thereby improving the reliability of the plate. Further, the interface thermal resistance between the copper layer and the insulating medium layer can be reduced by increasing the binding force, so that the heat dissipation performance of the plate is improved.

Specifically, referring to fig. 10, fig. 10 is a schematic structural diagram of an embodiment of a heat dissipation circuit board of the present application. The heat dissipation type circuit board 700 includes a plurality of core boards 10, and prepregs 20 are disposed between adjacent core boards 10. The core board 10 includes a dielectric layer 101 and copper layers 102 provided on both side surfaces of the dielectric layer 101. The outermost surfaces of the heat dissipation circuit board 700 are all the conductive layers 60 formed by electroplating. The heat dissipation type circuit board 700 comprises a depth control groove 70, wherein the bottom of the depth control groove 70 comprises a plurality of metallized through holes 51 which are densely distributed. Wherein, the side wall of the metallized through hole 51 forms a conductive copper layer 512, and the metallized through hole 51 is filled with an insulating material 511. Wherein the insulating material 511 may be resin or ink. The bottom of the depth control groove 70 is also provided with a plurality of metallized holes 81, and the metallized holes 81 and the metallized through holes 51 are staggered. Wherein, both the bottom and the side wall of the depth control groove 70 are electroplated with copper layers.

In contrast to the prior art, the deep control groove is formed in the dense radiating hole area of the plate to be processed, electroplating is conducted on the deep control groove, the high-power device is accommodated in the deep control groove after electroplating, and the plurality of metalized through holes densely distributed in the bottom of the deep control groove can be used for radiating the high-power device, so that radiating efficiency is improved. In addition, through forming a plurality of blind holes at the bottom of the depth control groove, the binding force between the copper layer and the groove bottom can be enhanced during electroplating, so that the overall reliability is improved. Through the mode, the metal-based process can be prevented from being used for heat dissipation, so that the preparation difficulty of the heat dissipation type circuit board is reduced, and the preparation cost is further reduced.

The foregoing description is only of embodiments of the present application, and is not intended to limit the scope of the patent application, and all equivalent structures or equivalent processes using the descriptions and the contents of the present application or other related technical fields are included in the scope of the patent application.

Claims

1. The preparation method of the heat dissipation type circuit board is characterized by comprising the following steps of:

obtaining a plate to be treated; the plate to be treated comprises at least one dense radiating hole area, wherein the dense radiating hole area comprises a plurality of metalized through holes which are densely distributed;

forming a depth control groove in each dense radiating hole area;

electroplating the depth control groove; the electroplated depth control groove is used for accommodating the high-power device.

2. The method according to claim 1, wherein,

after the step of forming the depth control groove in each dense radiating hole area, the method comprises the following steps:

forming a plurality of blind holes at the bottom of the depth control groove;

the step of electroplating the depth control groove to form a conductive layer at the bottom of the depth control groove further comprises the following steps:

electroplating a plurality of the blind holes to form a plurality of metallized holes.

3. The method according to claim 2, wherein,

the step of forming a plurality of blind holes at the bottom of the depth control groove comprises the following steps:

and processing a plurality of blind holes at the bottom of the depth control groove by using a laser ablation mode.

4. The method according to claim 1, wherein,

the step of forming a depth control groove in each densely-radiating hole area comprises the following steps:

processing the depth control groove in each dense radiating hole area according to the preset depth and size; the size of the depth control groove is larger than that of the dense radiating hole area.

5. The method according to claim 1, wherein,

and processing the depth control groove in the dense radiating hole area by utilizing a depth control milling groove mode.

6. The method according to claim 1, wherein,

the step of obtaining the board to be processed comprises the following steps:

obtaining a plate to be processed; wherein the plate to be processed is a multi-layer core plate obtained by lamination;

drilling dense holes in at least one preset area of the plate to be processed to form a plurality of through holes densely distributed in the preset area;

and carrying out hole metallization on the plurality of through holes to form a plurality of metallized through holes.

7. The method according to claim 6, wherein,

the step of hole metallizing the plurality of through holes to form a plurality of metallized through holes comprises:

and filling resin or ink in the plurality of the metallized through holes.

8. The method according to claim 6, wherein,

the step of drilling dense holes in at least one preset area of the plate to be processed to form a plurality of densely arranged through holes in the preset area comprises the following steps:

and drilling dense holes in the preset area of the plate to be processed by using a mechanical drilling mode so as to form a plurality of through holes densely distributed in the preset area.

9. The method according to claim 1, wherein,

the step of electroplating the depth control groove comprises the following steps:

depositing metal on the bottom and the side wall of the depth control groove to form a conductor film;

electroplating the depth control groove formed with the conductor film to form a conductive layer at the groove bottom and the side wall.

10. A heat dissipation type wiring board, characterized in that the heat dissipation type wiring board is manufactured by the manufacturing method of the heat dissipation type wiring board according to any one of claims 1 to 9; the heat dissipation type circuit board comprises at least one depth control groove, and a plurality of metalized through holes densely distributed are formed in the bottom of the depth control groove.