TWI778517B - Printed circuit board and method for manufacturing the same - Google Patents

Abstract

A printed circuit board includes an inner circuit substrate, an electronic component, a heat storage component, a first outer circuit substrate, and a second outer circuit substrate. The inner circuit substrate includes a first inner circuit layer, an inner dielectric layer, a second inner circuit layer and a first heat conductor. The electronic component is located on the surface of the inner circuit substrate and connected to the first inner circuit layer. The heat storage component is located on the surface of the inner circuit substrate away from the electronic components and connected to the second inner circuit layer. The first outer circuit substrate is located on the surface of the inner circuit substrate with electronic components and covers the electronic component. The second outer circuit substrate is located on the surface of the inner circuit substrate with the heat storage component and covers the heat storage component. The disclosure also provides a manufacturing method of the printed circuit board.

Description

Circuit board and method of making the same

The present application relates to the technical field of circuit boards, and in particular, to a circuit board and a manufacturing method of the circuit board.

Due to the continuous improvement of demand for electronic products, the integration of electronic components on the circuit board has been improved to meet the needs of high-frequency and high-speed operation. A lot of heat is generated during operation.

In the existing heat dissipation technology, a heat dissipation element connected to the casing is usually provided on the electronic product to transfer heat to the casing and dissipate into the air; or a copper block is embedded in the circuit board to increase the heat dissipation channel to achieve rapid heat dissipation. However, the heat is concentrated on the casing, resulting in high casing temperature and poor user experience (such as discomfort when holding electronic products); embedded copper blocks increase the weight of the circuit board, which is not in line with the thinning and lightness of electronic products. quantified properties.

Therefore, it is necessary to provide a circuit board capable of avoiding centralized heat dissipation and a manufacturing method of the above-mentioned circuit board, so as to solve the above-mentioned technical problems.

A circuit board includes an inner layer circuit substrate, an electronic component, a heat storage component, a first outer layer circuit substrate and a second outer layer circuit substrate. The inner layer circuit substrate includes the first inner layer wires arranged in layers The circuit layer, the inner layer dielectric layer and the second inner layer circuit layer also include a first heat conductor penetrating the inner layer dielectric layer and connected with the first inner layer circuit layer and the second inner layer circuit layer; the electronic components are located in the inner layer circuit layer. The surface of the substrate is connected with the first inner layer circuit layer; the heat storage component is located on the surface of the inner layer circuit substrate away from the electronic components and is connected with the second inner layer circuit layer; the first outer layer circuit substrate is located on the inner layer circuit substrate with electronic components. the surface and cover the electronic components; the second outer layer circuit substrate is located on the surface of the inner layer circuit substrate with the heat storage component and covers the heat storage component.

In some embodiments, the heat storage assembly includes a packaging body, a heat storage material and a first connecting body, the packaging body has a accommodating cavity; the heat storage material is accommodated in the accommodating cavity; the first connecting body and the packaging body form a closed accommodating body cavity; wherein, the first connecting body is connected with the second inner layer circuit layer.

In some embodiments, the heat storage material is selected from at least one of paraffin, organic acids, inorganic salts, brine compounds and polymer materials.

In some embodiments, the material of the first connector is selected from at least one of copper paste, silver paste, aluminum nitride, carbon nanotubes and graphene.

In some embodiments, the number of heat storage components is multiple, wherein the closer the distance to the electronic components, the higher the heat storage capacity.

In some embodiments, the circuit board further includes a second connecting body, and the second connecting body penetrates the second outer layer circuit substrate and the package body adjacent to the second outer layer circuit substrate.

In some embodiments, the heat storage component is connected to the second outer circuit substrate through a third connector, and the material of the third connector is selected from at least one of copper paste, silver paste, aluminum nitride, carbon nanotubes and graphene .

In some embodiments, the circuit board further includes a second thermal conductor located in the partial gap of the first inner wiring layer.

A method for manufacturing a circuit board, comprising the steps of: providing an inner-layer circuit substrate, comprising a first inner-layer circuit layer, an inner-layer dielectric layer and a second inner-layer circuit layer arranged in layers, and further comprising a penetrating inner layer. a first heat conductor connected to the first inner layer circuit layer and the second inner layer circuit layer; the electronic components are connected to the first inner layer circuit layer, and the heat storage component is connected to the second inner layer circuit layer; A first outer layer circuit substrate and a second outer layer circuit substrate are respectively formed on opposite surfaces of the inner layer circuit substrate, the first outer layer circuit substrate also covers electronic components, and the second outer layer circuit substrate also covers heat storage components to form a circuit board.

In some embodiments, the step of forming the inner layer circuit substrate includes: providing a first copper clad laminate including a first dielectric layer and a first copper layer and a second copper layer on opposite surfaces of the first dielectric layer; The through holes of the copper layer, the first dielectric layer and the second copper layer; the first thermal conductor is filled in the through holes; the first inner layer circuit layer is formed by wiring the first copper layer, and the circuit is formed on the second copper layer A second inner wiring layer is formed.

In some embodiments, before the step of connecting the electronic components on the first inner wiring layer, the method further includes filling a second thermal conductor in a partial gap of the first inner wiring layer.

In some embodiments, the step of connecting the heat storage component on the second inner circuit layer includes: providing a package body with a receiving cavity; placing a heat storage material in the receiving cavity; sealing the receiving cavity; forming on the package body The first opening of the heat storage material is connected, and the first connection body is filled in the first opening to form a heat storage component; the first connection body is connected with the second inner layer circuit layer.

In some embodiments, the step of forming the first outer layer circuit substrate and the second outer layer circuit substrate respectively on opposite surfaces of the inner layer circuit substrate includes: covering the surface of the second copper clad laminate with electronic components on the inner layer circuit substrate, covering the third outer layer circuit substrate The copper clad laminate has a surface of the heat storage component on the inner layer circuit substrate, the second copper clad laminate includes a stacked second dielectric layer and a third copper layer, and the third copper clad laminate includes a stacked third dielectric layer and a fourth copper layer; The third copper layer is fabricated to form a first outer layer circuit layer, and the fourth copper layer is fabricated to form a second outer layer circuit layer; wherein, the first outer layer circuit substrate includes a second dielectric layer and a first outer layer circuit layer, the first outer layer circuit layer. The second outer layer circuit substrate includes a third dielectric layer and a second outer layer circuit layer.

In some embodiments, before the step of forming the second outer layer of the fourth copper layer by circuit fabrication, the method further includes the step of: forming a second opening on the surface of the heat storage component facing away from the electronic components, the second opening passing through the fourth copper layer. The copper layer and the package body adjacent to the fourth copper layer, the second opening is connected with the heat storage material; before or at the same time as the second outer circuit layer is formed, a second connection body is filled in the second opening, and the second outer circuit layer is connected to the first circuit layer. Two linkers.

In some embodiments, the number of the heat storage components is plural, wherein the closer the distance to the electronic component, the higher the heat storage capacity.

In the circuit board with the heat storage component provided by the application, during the high load operation of the electronic component, the heat generated by the electronic component is first stored in the heat storage component to maintain a reasonable temperature when the electronic component is running; when the electronic component is not running During operation or low load operation, the heat stored in the heat storage component is slowly dissipated. The above circuit board not only prevents the heat generated by the electronic components from being concentrated and dissipated during high-load operation, causing the temperature around the electronic components to be too high and affecting the working state of the electronic components; At the same time, the quality of the materials composing the heat storage component is small, and the impact on the overall quality of the circuit board is small.

100: circuit board

10: Inner layer circuit substrate

11: inner dielectric layer

12: The first inner circuit layer

13: Second inner circuit layer

14: The first heat conductor

15: Second heat conductor

16: The first copper clad laminate

162: First copper layer

164: Second copper layer

166: Through hole

20: Electronic Components

30: Heat storage components

301: First subcomponent

302: Second child component

303: Third child component

31: Package body

312: accommodating cavity

33: The first opening

34: Second Opening

35: Thermal Storage Materials

36: The first connector

37: The third linker

38: Second connector

40: The first outer layer circuit substrate

41: Second dielectric layer

42: The first outer circuit layer

43: Second CCL

432: Third copper layer

50: Second outer circuit substrate

51: The third dielectric layer

52: Second outer circuit layer

53: The third copper clad laminate

532: Fourth copper layer

60: Solder mask

FIG. 1 is a schematic cross-sectional view of a first copper clad laminate provided in an embodiment of the present application.

FIG. 2 is a schematic cross-sectional view after forming a plurality of through holes on the first copper clad plate shown in FIG. 1 .

FIG. 3 is a schematic cross-sectional view after filling the first thermal conductor in the through hole of FIG. 2 and forming copper layers on both ends of the first thermal conductor.

FIG. 4 shows that after the first copper layer and the second copper layer shown in FIG. 3 are fabricated to form the first inner layer circuit layer and the second inner layer circuit layer, respectively, a second thermal conductivity is filled in the local gap of the first circuit layer. A schematic cross-sectional view of the inner layer circuit substrate formed after the body.

FIG. 5 is a schematic cross-sectional view of the inner-layer circuit substrate shown in FIG. 4 after connecting the electronic components and the heat storage components on two opposite surfaces respectively.

FIG. 6 is a schematic cross-sectional view of a package provided by an embodiment of the present application.

FIG. 7 is a schematic cross-sectional view of the package shown in FIG. 6 after the heat storage material is filled.

FIG. 8 is a schematic cross-sectional view of the heat storage material in FIG. 7 after being sealed in a package.

FIG. 9 is a schematic cross-sectional view after forming a first opening on the package body shown in FIG. 8 .

FIG. 10 is a schematic cross-sectional view after the first connecting body is formed in the first opening shown in FIG. 9 .

11 is a schematic cross-sectional view of the inner layer circuit substrate shown in FIG. 5 after the surface with electronic components is covered with a second copper clad laminate, and the surface with heat storage components is covered with a third copper clad laminate.

FIG. 12 is a schematic cross-sectional view after a second opening is formed on the package of the third copper clad laminate and the phase change element shown in FIG. 11 .

FIG. 13 is a schematic cross-sectional view after filling the second connecting body in the second opening shown in FIG. 12 .

14 is a schematic cross-sectional view after the third copper layer and the fourth copper layer shown in FIG. 13 are fabricated to form a first outer circuit layer and a second outer circuit layer, respectively, and a solder resist layer is formed.

In order to more clearly understand the above objects, features and advantages of the present application, the present application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features of the embodiments may be combined with each other unless there is conflict. Many specific details are set forth in the following description to facilitate a full understanding of the present application, and the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the present application are for the purpose of describing particular embodiments only, and are not intended to limit the present application. Book As used herein, the term "and/or" includes all and any combinations of one or more of the associated listed items.

Referring to FIGS. 1 to 14 , an embodiment of the present application provides a method for fabricating a circuit board 100 , including steps S1 - S7 .

Step S1 : Referring to FIG. 1 , a first copper clad laminate 16 is provided, which includes an inner dielectric layer 11 and a first copper layer 162 and a second copper layer 164 on opposite surfaces of the inner dielectric layer 11 .

The inner dielectric layer 11 may comprise at least one of polypropylene, epoxy resin, polyurethane, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, unsaturated resin, polyimide and other materials.

Step S2 : referring to FIG. 2 , a through hole 166 is formed through the first copper clad laminate 16 .

The through hole 166 penetrates the first copper clad laminate 16 along the stacking direction of the first copper clad laminate 16 , that is, the through hole 166 penetrates the first copper layer 162 , the inner dielectric layer 11 and the second copper layer 164 .

The number of the through holes 166 may be one or more, and the number of the through holes 166 may be set according to the number of the heat storage components 30 to be connected subsequently. In this embodiment, the number of the through holes 166 is plural.

In some embodiments, the through holes 166 include through holes 166 for subsequent filling of the first thermal conductor 14 , and may also include through holes 166 for forming conductive holes (not shown).

Step S3 : referring to FIG. 3 , fill the first thermal conductor 14 in the through hole 166 .

The material of the first thermal conductor 14 is selected from materials with good thermal conductivity to improve the efficiency of heat transfer. The material of the first thermal conductor 14 includes but is not limited to copper paste, silver paste, aluminum nitride, carbon nanotubes, graphene, etc. . Wherein, the material of the first thermal conductor 14 may be selected from conductive materials or insulating materials.

Step S4 : Referring to FIG. 4 , the first inner layer circuit layer 12 is formed by wiring the first copper layer 162 , and the second inner layer circuit layer 13 is formed by wiring the second copper layer 164 to form the inner layer circuit substrate 10.

The first inner layer wiring layer 12 and the second inner layer wiring layer 13 cover the first heat conductor 14 located in the through hole 166 , which facilitates heat transfer on opposite surfaces of the inner layer dielectric layer 11 .

In some embodiments, both ends of the first thermal conductor 14 filled in the through hole 166 may be filled with copper layers before being fabricated to form the first inner layer circuit layer 12 and the second inner layer circuit layer 13 . While forming the first inner layer wiring layer 12 and the second inner layer wiring layer 13 , the first heat conductor 14 is connected to the first inner layer wiring layer 12 and the second inner layer wiring layer 13 .

In some embodiments, a local gap filling second thermal conductor 15 on the first inner wiring layer 12 is also included. Wherein, partially filling the second heat conductor 15 is beneficial for heat transfer to the first inner circuit layer 12 by the second heat conductor 15 to transfer to the first heat conductor 14 in the through hole 166 and to other heat storage components 30 That is, the heat generated by the electronic components 20 can be transmitted in multiple channels, thereby increasing the heat conduction rate; and it can avoid the circuit layer short circuit caused by filling the first heat conductor 14 with electrical conductivity completely.

In other embodiments, the step of forming a conductive hole (not shown in the figure) may also be included to electrically connect the first inner layer wiring layer 12 and the second inner layer wiring layer 13 . The first inner layer circuit layer 12 and the second inner layer circuit layer 13 can be electrically connected only by the first heat conductor 14 with electrical conductivity, or by connecting the first inner layer circuit layer 12 and the second inner layer circuit layer 13 conductive holes for electrical connection.

Understandably, the number of circuit layers of the inner-layer circuit substrate 10 is not limited to two layers, and the number of dielectric layers is not limited to one. In other embodiments, the number of layers of the circuit layer and the dielectric layer can be set as required.

Step S5 : Referring to FIG. 5 , the electronic components 20 are connected to the first inner circuit layer 12 , and the heat storage component 30 is connected to the second inner circuit layer 13 .

The electronic component 20 is electrically connected to the first inner wiring layer 12 . The electronic component 20 will generate a certain amount of heat during operation, and the heat storage component 30 is used for absorbing and storing the heat, and releasing and dissipating the stored heat when the electronic component 20 is not working or operating at a low load, so as to be used in the circuit board 100. for electronic products In the middle, it can keep the temperature of the electronic product stable when it is working, prevent overheating from affecting the working state of the electronic product, and also prevent the overheating of the electronic product from causing a poor user experience.

Referring to FIGS. 6 to 10 , in some embodiments, the step of connecting the heat storage assembly 30 on the second inner circuit layer 13 may include S511-S515:

Step S511 : Please refer to FIG. 6 , provide a package body 31 with a accommodating cavity 312 .

The package body 31 has a gap (not shown in the figure), the gap communicates with the accommodating cavity 312 , and the gap can be disposed above or on the side of the package body 31 , and the gap is used for subsequent injection of the heat storage material 35 .

The package body 31 is an insulating material and needs to have a certain mechanical strength for accommodating the heat storage material 35 to prevent the heat storage material 35 from flowing out after melting. The material of the encapsulation body 31 can be selected from polyethylene (Density Polyethylene, DP), polystyrene (Polystyrene, PS), polypropylene (Polypropylene, PP), acrylonitrile-butadiene-styrene copolymers (Acrylonitrile Butadiene Sytrene copolymers) , ABS) and other materials at least one.

Step S512 : Referring to FIG. 7 , the heat storage material 35 is placed in the accommodating cavity 312 .

The heat storage material 35 is an insulating material.

In some embodiments, the heat storage material 35 has a high specific heat capacity, and at the melting point of the heat storage material 35 , the absorption and release of heat can be achieved through the principles of melting and solidification and exothermic solidification. For example, the heat storage material 35 can be selected from materials capable of mutual conversion between solid phase and liquid phase, such as paraffin, organic acids, inorganic salts, and brine compounds. In other embodiments, the heat storage material 35 can also be selected from polymer materials, including but not limited to esters (such as polyurethane), polyethylene, neopentyl glycol, etc., wherein the polymer material has no fixed melting point .

Step S513 : referring to FIG. 8 , the accommodating cavity 312 is sealed.

The gap is sealed so that the heat storage material 35 is sealed in the accommodating cavity 312 to prevent the heat storage material 35 from flowing out after melting.

Step S514 : Referring to FIG. 9 and FIG. 10 , a first connecting body 36 connected to the heat storage material 35 is formed on the package body 31 to form the heat storage assembly 30 .

A first opening 33 (refer to FIG. 9 ) is formed on the package body 31 , a first connection body 36 (refer to FIG. 10 ) is filled in the first opening 33 , and the material of the first connection body 36 is selected from materials with good thermal conductivity , including but not limited to copper paste, silver paste, aluminum nitride, carbon nanotubes, graphene, etc., in order to conduct heat quickly.

In some embodiments, the first opening 33 communicates with the accommodating cavity 312 , so that the first connecting body 36 formed in the first opening 33 is connected with the heat storage material 35 accommodated in the accommodating cavity 312 , thereby increasing the heat conduction efficiency .

Step S515 : Please also refer to FIG. 5 , connect the heat storage assembly 30 to the inner-layer circuit substrate 10 , and connect the first connecting body 36 to the second inner-layer circuit layer 13 .

In some embodiments, the second inner circuit layer 13 and the heat storage component 30 are connected through a third connecting body 37 , the third connecting body 37 is connected with the first connecting body 36 , and the material of the third connecting body 37 can be selected from thermally conductive Materials with good performance, including but not limited to copper paste, silver paste, aluminum nitride, carbon nanotubes, graphene, etc., in order to conduct heat quickly. In this embodiment, the material of the third connecting body 37 is selected from copper.

It can be understood that since the heat storage assembly 30 includes a package body 31 and a heat storage material 35 sealed in the package body 31 , the package body 31 and the heat storage material 35 are both insulating materials, and the material of the first connecting body 36 may be insulating materials , can also be a conductive material. Even if the first connecting body 36 is made of conductive material, due to the insulation between the package body 31 and the heat storage material 35 , the heat storage element 30 cannot form a conductive circuit with the second inner circuit layer 13 , that is, the heat storage element 30 and the circuit board 100 The circuit layers in the circuit are electrically insulated.

The number of heat storage assemblies 30 may be one or more.

In this embodiment, the number of heat storage assemblies 30 is five, including one first subassembly 301 , two second subassemblies 302 and two third subassemblies 303 . The distances between the two second subassemblies 302 and the electronic components 20 are equal, and the distances between the two third subassemblies 303 and the electronic components 20 are equal; The distance between the subassembly 301 and the electronic element 20 is the closest, the distance between the second subassembly 302 and the electronic element 20 is in the middle, and the distance between the third subassembly 303 and the electronic element 20 is the farthest. The heat storage capacity of the heat storage material 35 in the first subassembly 301 , the second subassembly 302 and the third subassembly 303 is different, wherein the closer the distance to the electronic component 20 , the greater the heat storage capacity of the heat storage assembly 30 , that is, the heat storage capacity of the first sub-assembly 301 , the second sub-assembly 302 and the third sub-assembly 303 decreases sequentially.

Compared with the second sub-assembly 302 and the third sub-assembly 303, the first sub-assembly 301, which is closest to the electronic component 20, can absorb and transfer the most heat. The subassembly 302 communicates with the third subassembly 303 , that is, the farther it is from the electronic component 20 , the less heat can be absorbed. Providing the heat storage assembly 30 with multiple heat storage capabilities is beneficial to avoid the phenomenon that the heat storage assembly 30 close to the electronic component 20 cannot absorb heat in time, which causes the surrounding of the electronic component 20 to heat up too quickly; Thermal components 30 do not have sufficient heat absorption resulting in wasted resources.

When the electronic component 20 does not work or operates at a low load, the heat generation of the electronic component 20 decreases, the heat storage material 35 in the heat storage component 30 gradually releases heat, and the stored heat is dissipated through the circuit layer connected to the heat storage component 30 to the air, so as to avoid the defect that the heat of the electronic component 20 is difficult to dissipate in time during high-load operation.

The heat storage capacity of the heat storage assembly 30 is related to the quality of the heat storage material 35 sealed in the package body 31 and the type of the heat storage material 35 . Among them, the higher the quality of the heat storage material 35, the greater the heat storage capacity of the heat storage assembly 30; the different types of the heat storage material 35, the specific heat capacity and the melting point of the heat storage material 35 are also different, which will have a certain impact on the heat storage capacity. influences. For example, in some embodiments, heat storage components 30 with the same quality of heat storage material 35 can be provided, and the heat storage capacity of the heat storage component 30 can be changed by changing the type of heat storage material 35; in other embodiments, The heat storage assemblies 30 having the same kind of heat storage materials 35 can be provided, and the heat storage capacity of the heat storage assemblies 30 can be changed by changing the quality of the heat storage materials 35 .

Step S6 : referring to FIGS. 11 to 14 , a first outer layer circuit substrate 40 and a second outer layer circuit substrate 50 are respectively formed on opposite surfaces of the inner layer circuit substrate 10 , the first outer layer circuit substrate 40 also covers the electronic components 20 , and the second outer layer circuit substrate 40 The outer layer circuit substrate 50 also covers the heat storage assembly 30 to form the circuit board 100 .

The step of forming the first outer layer circuit substrate 40 and the second outer layer circuit substrate 50 may include steps S611-S612.

Step S611 : Please refer to FIG. 11 , cover the surface of the second CCL 43 with the electronic components 20 on the inner circuit substrate 10 , and cover the third CCL 53 with the surface of the inner circuit substrate 10 with the heat storage element 30 .

The second copper clad laminate 43 includes a second dielectric layer 41 and a third copper layer 432 located on the surface of the second dielectric layer 41. The second dielectric layer 41 is connected to the first inner circuit layer 12 and the electronic components 20; the third copper clad laminate 53 It includes a third dielectric layer 51 and a fourth copper layer 532 located on the surface of the third dielectric layer 51 . The third dielectric layer 51 is connected to the second inner layer circuit layer 13 and the heat storage component 30 .

Step S612 : Referring to FIG. 14 , wiring is performed on the third copper layer 432 to form the first outer wiring layer 42 , and wiring is performed on the fourth copper layer 532 to form the second outer wiring layer 52 .

The first outer circuit layer 42 and the second dielectric layer 41 form the first outer circuit substrate 40 , and the second outer circuit layer 52 and the third dielectric layer 51 form the second outer circuit substrate 50 .

It can be understood that, before forming the first outer circuit layer 42 and the second outer circuit layer 52 , it also includes forming conductive holes respectively passing through the second dielectric layer 41 and the third dielectric layer 51 and connecting the inner circuit substrate 10 . In order to electrically connect the first outer layer wiring layer 42 and the second outer layer wiring layer 52 to the inner layer wiring substrate 10 .

In some embodiments, the step of forming the first outer layer circuit substrate 40 and the second outer layer circuit substrate 50 may also include steps S621-S623.

Step S621 : covering the second dielectric layer 41 on the surface of the inner-layer circuit substrate 10 having the electronic components 20 , the electronic components 20 are accommodated in the second dielectric layer 41 and a surface of the second dielectric layer 41 is exposed; The third dielectric layer 51 is covered on the surface of the inner circuit substrate 10 having the heat storage element 30 , and the heat storage element 30 is accommodated in the third dielectric layer 51 and a surface of the third dielectric layer 51 is exposed.

Step S622 : covering the third copper layer 432 on the surface of the second dielectric layer 41 , the third copper layer 432 also covering the electronic component 20 ; covering the fourth copper layer 532 on the surface of the third dielectric layer 51 , the fourth copper layer 532 also covering The heat storage assembly 30 is covered to reduce the distance between the heat storage assembly 30 and the local area of the fourth copper layer 532, thereby shortening the heat transfer path.

Step S623 : performing wiring on the third copper layer 432 to form the first outer wiring layer 42 , and performing wiring on the fourth copper layer 532 to form the second outer wiring layer 52 .

In some embodiments, before forming the first outer wiring layer 42 and the second outer wiring layer 52, the following steps are further included:

Step S6221 : Referring to FIG. 12 , a second opening 34 is formed on the surface of the heat storage component 30 facing away from the electronic component 20 . The second opening 34 penetrates the fourth copper layer 532 and the package body 31 adjacent to the fourth copper layer 532 . The opening 34 is connected with the heat storage material 35 , that is, the heat storage material 35 sealed in the package body 31 is exposed to the second opening 34 .

In some embodiments, the second opening 34 also penetrates the third dielectric layer 51 located between the fourth copper layer 532 and the package body 31 .

Step S6222 : Referring to FIG. 13 , fill the second connecting body 38 in the second opening 34 . The material of the second connecting body 38 can be selected from materials with good thermal conductivity, including but not limited to copper paste, silver paste, aluminum nitride, carbon nanotube, graphene, etc., so as to facilitate rapid heat conduction.

In some embodiments, when the second outer wiring layer 52 is formed, the second connecting body 38 may be formed in the second opening 34 , that is, the step S6222 and the step of forming the second outer wiring layer 52 may be performed simultaneously. The heat storage assembly 30 is connected with the second outer circuit layer 52 located on the outer layer of the circuit board 100 through the second connecting body 38 with good thermal conductivity, which is more conducive to heat dissipation.

In some embodiments, the manufacturing method of the circuit board 100 may further include step S7: referring to FIG. 14 , forming a solder resist layer 60 on the surfaces of the first outer layer circuit substrate 40 and the second outer layer circuit substrate 50 away from the inner layer circuit substrate 10 , to form the circuit board 100 . The solder resist layer 60 covers the first outer circuit layer 42 and the second outer circuit layer 52 respectively.

Referring to FIG. 14 , the present application also provides a circuit board 100 , the circuit board 100 includes an inner layer circuit substrate 10 , electronic components 20 on opposite surfaces of the inner layer circuit substrate 10 , a heat storage component 30 , a first outer layer circuit substrate 40 and The second outer layer circuit substrate 50 . The first outer layer circuit substrate 40 and the second outer layer circuit substrate 50 are electrically connected to the inner layer circuit substrate 10 . The first outer layer circuit substrate 40 is located on the surface of the inner layer circuit substrate 10 connected to the electronic components 20 and covers the electronic components 20, and the second outer layer circuit substrate 50 is located on the surface of the inner layer circuit substrate 10 connected with the heat storage component 30 and covers the heat storage component 30.

The inner layer circuit substrate 10 includes an inner layer dielectric layer 11 , a first inner layer circuit layer 12 , a second inner layer circuit layer 13 and a first heat conductor 14 . The first inner layer circuit layer 12 and the second inner layer circuit layer 13 are located on opposite surfaces of the inner layer dielectric layer 11 and are electrically connected to each other; the first heat conductor 14 penetrates through the inner layer dielectric layer 11 and is connected to the first inner layer circuit layer 12 and The second inner wiring layer 13 is connected to increase the thermal conductivity.

The material of the first thermal conductor 14 may be selected from at least one of copper paste, silver paste, aluminum nitride, carbon nanotubes and graphene. In some embodiments, the first thermal conductor 14 may also function as an electrical conductor.

In some embodiments, the partial gaps of the first inner wiring layer 12 are also filled with the second heat conductor 15, which is beneficial to the multi-channel transfer of heat, so as to improve the heat transfer efficiency.

The electronic component 20 is located on the surface of the inner layer circuit substrate 10 having the first inner layer circuit layer 12 and is electrically connected to the first inner layer circuit layer 12 . The electronic components 20 generate a certain amount of heat during operation.

The heat storage component 30 is located on the surface of the inner layer circuit substrate 10 having the second inner layer circuit layer 13 and is connected to the second inner layer circuit layer 13 through a third connecting body 37 . The material of the third connecting body 37 can be selected from thermally conductive Materials with good performance, including but not limited to copper paste, silver paste, aluminum nitride, carbon nanotubes, graphene, etc., in order to conduct heat quickly.

Referring to FIG. 10 , the heat storage component 30 includes a package body 31 , a heat storage material 35 and a first connecting body 36 . The package body 31 and the first connecting body 36 form a closed accommodating groove, and the heat storage material 35 is accommodated in the accommodating groove.

Referring to FIG. 14 , the first outer circuit substrate 40 includes a second dielectric layer 41 and a first outer circuit layer 42 located on the surface of the second dielectric layer 41 . The second dielectric layer 41 is connected to the inner layer circuit substrate 10 , and the first outer layer circuit layer 42 is located on the surface of the second dielectric layer 41 away from the inner layer circuit substrate 10 ; the first outer layer circuit substrate 40 also covers the electronic components 20 .

The second outer circuit substrate 50 includes a third dielectric layer 51 and a second outer circuit layer 52 located on the surface of the third dielectric layer 51 . The third dielectric layer 51 is connected to the inner circuit substrate 10 , the second outer circuit layer 52 is located on the surface of the third dielectric layer 51 away from the inner circuit substrate 10 ; the second outer circuit substrate 50 also covers the heat storage assembly 30 .

In some embodiments, the circuit board 100 may further include a second connecting body 38 , the second connecting body 38 penetrates the second outer layer circuit substrate 50 and the package body 31 adjacent to the second outer layer circuit substrate 50 , and the second connecting body 38 is connected to the package The heat storage material 35 in the body 31 and the second outer wiring layer 52 are used to increase the heat transfer rate.

In some embodiments, the circuit board 100 may further include a solder resist layer 60 covering the surfaces of the first outer layer circuit substrate 40 and the second outer layer circuit substrate 50 facing away from the inner layer circuit substrate 10 , respectively.

In the circuit board 100 provided with the heat storage assembly 30 provided by the present application, during the high-load operation of the electronic element 20, part of the heat generated by the electronic element 20 is first stored in the heat storage assembly 30, so as to maintain the reasonable operation of the electronic element 20. Temperature; when the electronic component 20 is not running or running at a low load, the heat stored in the heat storage component 30 is slowly dissipated. The above circuit board 100 not only prevents the electronic components 20 from running under high load It is difficult to dissipate the heat generated when the temperature around the electronic component 20 is too high and affects the working state of the electronic component 20; it also avoids the concentrated heat transfer to the casing of the electronic product and causes poor user experience; at the same time, the heat storage component 30 is formed. The quality of the material is small, and the impact on the overall quality of the circuit board 100 is small.

The above embodiments are only used to illustrate the technical solutions of the present application rather than limitations. Although the present application has been described in detail with reference to the above preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be modified or equivalently replaced. Neither should depart from the spirit and scope of the technical solutions of the present application.

100: circuit board

11: inner dielectric layer

12: The first inner circuit layer

13: Second inner circuit layer

14: The first heat conductor

15: Second heat conductor

20: Electronic Components

30: Heat storage components

301: First subcomponent

37: The third linker

38: Second connector

40: The first outer layer circuit substrate

41: Second dielectric layer

42: The first outer circuit layer

50: Second outer circuit substrate

51: The third dielectric layer

52: Second outer circuit layer

60: Solder mask

Claims (13)

A circuit board, which is improved by comprising: an inner layer circuit substrate, including a first inner layer circuit layer, an inner layer dielectric layer and a second inner layer circuit layer that are stacked and arranged, and further comprising passing through the inner layer dielectric layer and connecting with all the layers. a first heat conductor connected to the first inner layer circuit layer and the second inner layer circuit layer; a second heat conductor is located in the local gap of the first inner layer circuit layer; electronic components are located in the inner layer The surface of the circuit substrate is connected with the first inner layer circuit layer; the heat storage component is located on the surface of the inner layer circuit substrate away from the electronic components and connected with the second inner layer circuit layer; the first outer layer circuit a substrate located on the inner layer circuit substrate having the surface of the electronic component and covering the electronic component; and a second outer layer circuit substrate located on the inner layer circuit substrate having the surface of the heat storage component and covering the heat storage component thermal components. The circuit board according to claim 1, wherein the heat storage component comprises: a package body having an accommodating cavity; a heat storage material accommodated in the accommodating cavity; and a first connecting body connected to the package body A closed accommodating cavity is formed; wherein, the first connecting body is connected with the second inner circuit layer. The circuit board according to claim 2, wherein the heat storage material is selected from at least one of paraffin, organic acid, inorganic salt, salt water compound and polymer material. The circuit board according to claim 2, wherein the material of the first connector is selected from at least one of copper paste, silver paste, aluminum nitride, carbon nanotubes and graphene. The circuit board of claim 2, wherein the number of the heat storage components is multiple, and the closer the distance to the electronic component, the higher the heat storage capacity. The circuit board of claim 2, wherein the circuit board further comprises a second connecting body, the second connecting body penetrating the second outer layer circuit substrate and the package body adjacent to the second outer layer circuit substrate . The circuit board according to claim 1, wherein the heat storage component and the second outer layer circuit substrate are connected through a third connecting body, and the material of the third connecting body is selected from copper paste, silver paste, aluminum nitride , at least one of carbon nanotubes and graphene. A method for manufacturing a circuit board, which is improved in that it includes the steps of: providing an inner-layer circuit substrate, including a first inner-layer circuit layer, an inner-layer dielectric layer and a second inner-layer circuit layer that are stacked and arranged, and further comprising penetrating the inner layer. a first heat conductor connected to the first inner layer circuit layer and the second inner layer circuit layer; a second heat conductor is filled in the partial gap of the first inner layer circuit layer; Electronic components are connected on the first inner layer circuit layer, and heat storage components are connected on the second inner layer circuit layer; and a first outer layer circuit substrate and a second outer layer circuit substrate are respectively formed on two opposite surfaces of the inner layer circuit substrate , the first outer layer circuit substrate also covers the electronic components, and the second outer layer circuit substrate also covers the heat storage component to form the circuit board. The method for fabricating a circuit board according to claim 8, wherein the step of forming the inner layer circuit substrate comprises: providing a first copper clad laminate, comprising a first dielectric layer and a first dielectric layer located on two opposite surfaces of the first dielectric layer a copper layer and a second copper layer; forming a through hole through the first copper layer, the first dielectric layer and the second copper layer; filling the first thermal conductor in the through hole; The first copper layer is subjected to circuit fabrication to form the first inner layer circuit layer, and the second copper layer is subjected to circuit fabrication to form the second inner layer circuit layer. The method for fabricating a circuit board according to claim 8, wherein the step of connecting the heat storage component on the second inner circuit layer comprises: providing a package body with an accommodating cavity; placing a package in the accommodating cavity inserting a heat storage material; sealing the accommodating cavity; forming a first opening on the package body for connecting the heat storage material, and filling the first connecting body in the first opening to form the heat storage assembly; and connecting the first connector with the second inner circuit layer. The method for manufacturing a circuit board according to claim 10, wherein the step of forming the first outer layer circuit substrate and the second outer layer circuit substrate on two opposite surfaces of the inner layer circuit substrate respectively comprises: covering a second copper clad laminate The surface of the inner layer circuit substrate with the electronic components is covered, a third copper clad laminate is covered on the inner layer circuit substrate with the surface of the heat storage component, and the second copper clad laminate includes a stacked second dielectric layer and a third copper layer, the third copper clad laminate includes a stacked third dielectric layer and a fourth copper layer; and the third copper layer is fabricated to form a first outer circuit layer, and the fourth copper layer is The second outer layer circuit layer is formed by circuit fabrication; wherein, the first outer layer circuit substrate includes the second dielectric layer and the first outer layer circuit layer, and the second outer layer circuit substrate includes the third dielectric layer and the second outer circuit layer. The method for fabricating a circuit board according to claim 11, wherein before the step of forming the second outer layer of the fourth copper layer by wiring the fourth copper layer, it further comprises the step of: when the heat storage component is away from the A second opening is formed on the surface of the electronic component, the second opening penetrates the fourth copper layer and the package body adjacent to the fourth copper layer, and the second opening is connected to the heat storage material; and Before or simultaneously with the formation of the second outer wiring layer, a second connection body is filled in the second opening, and the second outer wiring layer is connected to the second connection body. The method for manufacturing a circuit board according to claim 8, wherein the number of the heat storage components is multiple, and the closer the distance to the electronic components, the higher the heat storage capacity.

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