Circuit board with heat dissipation structure and its manufacturing method

Abstract

A circuit board with a heat dissipation structure and its manufacturing method are disclosed. The circuit board with the heat dissipation structure includes a coolant and a first outer circuit layer, an inner circuit substrate, and a second outer circuit layer stacked sequentially. The inner circuit substrate is divided into a heat dissipation area and a non-heat dissipation area. The inner circuit substrate includes a plurality of through holes and a first circuit layer and a second circuit layer spaced apart along the thickness direction on the outermost side. Each through hole is located in the heat dissipation area and penetrates the first circuit layer and the second circuit layer along the thickness direction. The first outer circuit layer and the second outer circuit layer seal the two sides of the heat dissipation area spaced apart along the thickness direction to form a sealed cavity corresponding to the heat dissipation area. The coolant is contained in the sealed cavity, thereby directly contacting the circuit and facilitating heat dissipation.

Description

Technical Field

[0001] This invention relates to the field of circuit boards, and more particularly to a circuit board with a heat dissipation structure and a method for manufacturing the same. Background Technology

[0002] With the development of 5G technology, electronic products are becoming increasingly integrated and miniaturized, leading to higher assembly densities and greater power consumption. Consequently, the heat dissipation requirements for circuit boards in electronic products are also increasing. Currently, the heat dissipation performance of circuit boards cannot meet these demands. Summary of the Invention

[0003] In view of this, the present invention provides a circuit board with a heat dissipation structure, which has good heat dissipation effect and simple structure.

[0004] A method for manufacturing a circuit board with a heat dissipation structure that has good heat dissipation performance and simple process is also provided.

[0005] This application discloses a circuit board with a heat dissipation structure, comprising a coolant and a first outer circuit layer, an inner circuit substrate, and a second outer circuit layer stacked sequentially. The inner circuit substrate is divided into a heat dissipation area and a non-heat dissipation area. The inner circuit substrate includes a plurality of through holes and a first circuit layer and a second circuit layer spaced apart along the thickness direction on the outermost side. Each through hole is located in the heat dissipation area and penetrates the first circuit layer and the second circuit layer along the thickness direction. The first outer circuit layer and the second outer circuit layer seal the two sides of the heat dissipation area spaced apart along the thickness direction to form a sealed cavity corresponding to the heat dissipation area. The coolant is contained within the sealed cavity.

[0006] As one embodiment of this application, the lines in the first circuit layer corresponding to the heat dissipation area are straight channels, and the lines in the second circuit layer corresponding to the heat dissipation area are bent channels.

[0007] As one embodiment of this application, each of the vias is a conductive via, and the surface of the inner circuit board substrate has a capillary structure.

[0008] As one embodiment of this application, the circuit board further includes a first adhesive layer, a second adhesive layer, a first insulating layer, and a second insulating layer. The first outer circuit layer is bonded to the portion of the first circuit layer corresponding to the heat dissipation area through the first adhesive layer, and is bonded to the portion of the first circuit layer corresponding to the non-heat dissipation area through the first insulating layer. The second outer circuit layer is bonded to the portion of the second circuit layer corresponding to the heat dissipation area through the second adhesive layer, and is bonded to the portion of the second circuit layer corresponding to the non-heat dissipation area through the second insulating layer.

[0009] As one embodiment of this application, it also includes electronic components, which are disposed on the portion of the first outer circuit layer corresponding to the heat dissipation area or the portion of the second outer circuit layer corresponding to the heat dissipation area.

[0010] As one aspect of this application, a method for manufacturing a circuit board with a heat dissipation structure includes the following steps:

[0011] An inner circuit board is provided, the inner circuit board being divided into a heat dissipation area and a non-heat dissipation area, the inner circuit board including a plurality of vias and a first circuit layer and a second circuit layer spaced apart along the thickness direction and located on the outermost side, each of the vias being located in the heat dissipation area and penetrating the first circuit layer and the second circuit layer along the thickness direction.

[0012] A first adhesive layer is provided on the surface of the first circuit layer that is away from the second circuit layer, corresponding to the heat dissipation area, to obtain a first intermediate structure;

[0013] A first insulating layer with a first opening is provided. The first intermediate structure, the first insulating layer and a first metal foil are sequentially stacked and pressed together to obtain a second intermediate structure. The first insulating layer is bonded between the first circuit layer and the first metal foil. The first opening corresponds to the heat dissipation area of ​​the first intermediate structure. The first adhesive layer bonds the heat dissipation area and the first metal foil. The first metal foil, the first adhesive layer and the heat dissipation area form a receiving space.

[0014] Coolant is injected into the containment space through the through-hole to obtain the third intermediate structure;

[0015] A second adhesive layer is provided on the surface of the second circuit layer opposite to the first circuit layer, corresponding to the heat dissipation area;

[0016] A second insulating layer with a second opening is provided, and a third intermediate structure having a second adhesive layer, the second insulating layer, and a second metal foil are sequentially stacked and pressed together to obtain a fourth intermediate structure. The second insulating layer is bonded between the second circuit layer and the second metal foil. The second opening corresponds to the heat dissipation area. The second adhesive layer bonds the heat dissipation area and the second metal foil to seal the receiving space to form a sealed cavity.

[0017] The fourth intermediate structure is fabricated to form a first outer circuit layer and a second outer circuit layer, respectively, by pairing the first metal foil and the second metal foil.

[0018] As one embodiment of this application, it also includes:

[0019] At least one electronic component is mounted on the portion of the first outer circuit layer corresponding to the heat dissipation area or on the portion of the second outer circuit layer corresponding to the heat dissipation area.

[0020] As one embodiment of this application, the lines in the first circuit layer corresponding to the heat dissipation area are straight channels; the lines in the second circuit layer corresponding to the heat dissipation area are bent channels.

[0021] As one aspect of this application, in the first intermediate structure, in any direction perpendicular to the thickness direction, the periphery of the circuit of the first circuit layer having the first adhesive layer protrudes from the periphery of the corresponding first adhesive layer.

[0022] When the second adhesive layer is provided, in any direction perpendicular to the thickness direction, the periphery of the circuit of the second circuit layer on which the second adhesive layer is provided protrudes from the periphery of the corresponding second adhesive layer.

[0023] As one aspect of this application, before setting the first adhesive layer, the inner circuit board substrate is further subjected to surface treatment to increase surface roughness.

[0024] The circuit board with heat dissipation structure and its manufacturing method disclosed in this application allow the coolant and the vapor it generates, which are contained in the sealed cavity, to directly contact and circulate with the portion of the first circuit layer corresponding to the heat dissipation area and the portion of the second circuit layer corresponding to the heat dissipation area. This is beneficial for improving heat dissipation efficiency and thus extending the service life of the circuit board. Attached Figure Description

[0025] Figure 1 This is a cross-sectional schematic diagram of an inner layer circuit board according to an embodiment of this application.

[0026] Figure 2 This is a cross-sectional schematic diagram of the first intermediate structure according to an embodiment of this application.

[0027] Figure 3 To be Figure 2 A cross-sectional schematic diagram of the first intermediate structure, a first insulating layer, and a first metal foil layer stacked together.

[0028] Figure 4 This is a cross-sectional schematic diagram of the second intermediate structure according to an embodiment of this application.

[0029] Figure 5 This is a cross-sectional schematic diagram of the third intermediate structure according to an embodiment of this application.

[0030] Figure 6 In order to be in Figure 5 A cross-sectional schematic diagram showing the second adhesive layer disposed on the third intermediate structure.

[0031] Figure 7 To be Figure 6 The diagram shows a cross-sectional view of a third intermediate structure with a second adhesive layer, a second insulating layer, and a second metal foil layer.

[0032] Figure 8 This is a cross-sectional schematic diagram of the fourth intermediate structure according to an embodiment of this application.

[0033] Figure 9 To Figure 8 The diagram shows a cross-sectional view of the fourth intermediate structure used to fabricate the first outer circuit layer and the second outer circuit layer.

[0034] Figure 10 To place an electronic component in Figure 8 The diagram shows a cross-sectional view of the second outer circuit layer.

[0035] Figure 11 A cross-sectional schematic diagram of a circuit board with a heat dissipation structure according to an embodiment of this application.

[0036] Figure 12 A cross-sectional view of a circuit board with a heat dissipation structure according to another embodiment of this application.

[0037] Explanation of main component symbols

[0038] Inner circuit board 10

[0039] Heat dissipation area 101

[0040] Non-heat dissipation area 103

[0041] Through hole 105

[0042] First line layer 11

[0043] Second line layer 13

[0044] First adhesive layer 21

[0045] First intermediate structure 20a

[0046] First window opening 310

[0047] First insulating layer 31

[0048] Second intermediate structure 20b

[0049] First metal foil 41

[0050] Containment Space 201

[0051] Coolant 50

[0052] Third intermediate structure 20c

[0053] Second adhesive layer 23

[0054] Second window 330

[0055] Second insulating layer 33

[0056] Second metal foil 43

[0057] Fourth intermediate structure 20d

[0058] Sealed cavity 203

[0059] First outer circuit layer 410

[0060] Second outer circuit layer 430

[0061] First metal plate 411

[0062] Second metal plate 431

[0063] Conductive hole 45

[0064] Electronic Components 60

[0065] Solder resist layer 65

[0066] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0067] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0069] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0070] Please see Figures 1 to 10 This application provides a method for manufacturing a circuit board with a heat dissipation structure, which includes the following steps:

[0071] Step S1, please refer to Figure 1An inner circuit board 10 is provided, which is divided into a heat dissipation area 101 and a non-heat dissipation area 103. The inner circuit board 10 includes a plurality of vias 105 and a first circuit layer 11 and a second circuit layer 13 spaced apart along the thickness direction and located on the outermost side. Each via 105 is located in the heat dissipation area 101 and penetrates the first circuit layer 11 and the second circuit layer 13 along the thickness direction.

[0072] In this embodiment, the lines in the first circuit layer 11 corresponding to the heat dissipation area 101 can be straight channels. The lines in the second circuit layer 13 corresponding to the heat dissipation area 101 can be bent channels. The straight channels facilitate the flow of liquid substances (e.g., coolant), while the bent channels, when serving as evaporation channels for gas, increase the contact area between the gas and the circuit, thereby facilitating heat removal. The specific shape of the bent channels is not limited, and may include, but is not limited to, S-shaped, wavy, or serrated shapes.

[0073] In this embodiment, the lines in the second circuit layer 13 corresponding to the heat dissipation area 101 can have a fine spacing, resulting in a high density of line distribution in the second circuit layer 13 corresponding to the heat dissipation area 101.

[0074] The inner circuit board 10 can be a two-layer circuit board, a three-layer circuit board, a four-layer circuit board, a five-layer circuit board, etc. When the inner circuit board 10 is a three-layer or higher circuit board, the inner circuit board 10 further includes at least one inner circuit layer (not shown in the figure), which is located between the first circuit layer 11 and the second circuit layer 13, and is stacked and spaced apart from the first circuit layer 11 and the second circuit layer 13 respectively in the thickness direction. In this embodiment, the inner circuit board 10 is described as a two-layer circuit board.

[0075] In this embodiment, the through hole 105 is preferably a conductive hole. In some embodiments, the through hole 105 may also be a non-conductive hole.

[0076] For step S2, please refer to [link / reference]. Figure 2 A first adhesive layer 21 is provided on the surface of the first circuit layer 11 opposite to the second circuit layer 13, corresponding to the heat dissipation area 101, to obtain a first intermediate structure 20a.

[0077] Preferably, in any direction perpendicular to the thickness direction, the width of the first adhesive layer 21 is smaller than the width of the corresponding line in the first wiring layer 11. More preferably, in any direction perpendicular to the thickness direction, the periphery of the line in the first wiring layer 11 protrudes from the periphery of the corresponding first adhesive layer 21. In some embodiments, the width by which the periphery of the line in the first wiring layer 11 protrudes from the periphery of the corresponding first adhesive layer 21 may be greater than or equal to 0.1 mm. The above design helps to reduce the misalignment of the first adhesive layer 21 and also helps to reduce the overflow of the first adhesive layer 21 during subsequent lamination.

[0078] Preferably, the first adhesive layer 21 is made of a thermally conductive adhesive with good corrosion resistance.

[0079] Step S3, please refer to Figure 3 and Figure 4 A first insulating layer 31 with a first opening 310 is provided. The first intermediate structure 20a, the first insulating layer 31, and a first metal foil 41 are sequentially stacked and pressed together to obtain a second intermediate structure 20b. The first insulating layer 31 is bonded between the first circuit layer 11 and the first metal foil 41, and the first opening 310 corresponds to the heat dissipation area 101 of the first intermediate structure 20a. The first adhesive layer 21 bonds the heat dissipation area 101 to the first metal foil 41, and the first metal foil 41, the first adhesive layer 21, and the heat dissipation area 101 form a receiving space 201.

[0080] For step S4, please refer to [link / reference]. Figure 5 Coolant 50 is injected into the receiving space 201 through the through hole 105 to obtain the third intermediate structure 20c.

[0081] For step S5, please refer to [link / reference]. Figure 6 A second adhesive layer 23 is provided on the surface of the second circuit layer 13 opposite to the first circuit layer 11, corresponding to the heat dissipation area 101.

[0082] Preferably, in any direction perpendicular to the thickness direction, the width of the second adhesive layer 23 is smaller than the width of the corresponding line in the second wiring layer 13. More preferably, in any direction perpendicular to the thickness direction, the periphery of the line in the second wiring layer 13 protrudes from the periphery of the corresponding second adhesive layer 23. In some embodiments, the width by which the periphery of the line in the second wiring layer 13 protrudes from the periphery of the corresponding second adhesive layer 23 may be greater than or equal to 0.1 mm. The above design helps to reduce the possibility of misalignment of the second adhesive layer 23, and also helps to reduce the overflow of the second adhesive layer 23 during subsequent lamination.

[0083] Preferably, the second adhesive layer 23 is a thermally conductive adhesive with good corrosion resistance.

[0084] Step S6, please refer to Figure 7 and Figure 8 A second insulating layer 33 with a second opening 330 is provided, and a third intermediate structure 20c having a second adhesive layer 23, the second insulating layer 33, and a second metal foil 43 are sequentially stacked and pressed together to obtain a fourth intermediate structure 20d. The second insulating layer 33 is bonded between the second circuit layer 13 and the second metal foil 43, and the second opening 330 corresponds to the heat dissipation area 101. The second adhesive layer 23 bonds the heat dissipation area 101 and the second metal foil 43 to seal the receiving space 201 to form a sealed cavity 203.

[0085] For step S7, please refer to [link / reference]. Figure 8 and Figure 9 The fourth intermediate structure 20d is fabricated to form a circuit so that the first metal foil 41 and the second metal foil 43 form a first outer circuit layer 410 and a second outer circuit layer 430, respectively.

[0086] The first outer circuit layer 410 includes a first metal plate 411 corresponding to the heat dissipation area 101, and the second outer circuit layer 430 includes a second metal plate 431 corresponding to the heat dissipation area 101.

[0087] In some embodiments, the fourth intermediate structure 20d may be fabricated to form a conductive hole 45, which may electrically connect the first outer circuit layer 410 to the inner circuit substrate 10 and / or electrically connect the second outer circuit layer 430 to the inner circuit substrate 10.

[0088] Step S8, please refer to Figure 10 At least one electronic component 60 is mounted on the portion of the first outer circuit layer 410 corresponding to the heat dissipation area 101 or on the portion of the second outer circuit layer 430 corresponding to the heat dissipation area 101.

[0089] In this embodiment, the electronic component 60 is mounted on the second metal plate 431. The high line density of the second circuit layer 13 corresponding to the heat dissipation area 101 facilitates the rapid dissipation of heat generated by the electronic component 60, reducing the risk of heat concentration. In some embodiments, the electronic component 60 may also be mounted on the first metal plate 411.

[0090] In some embodiments, before applying the first adhesive layer 21, the inner circuit board 10 may undergo a surface treatment to increase its surface roughness. This surface treatment may be, but is not limited to, browning. Increased surface roughness of the inner circuit board 10 enhances adhesion to the first adhesive layer 21, the first insulating layer 31, and the second insulating layer 33 in subsequent bonding processes. Furthermore, increased surface roughness of the inner circuit board 10 also improves the capillary action of the subsequently formed sealing cavity 203.

[0091] In some embodiments, after the fourth intermediate structure 20d is fabricated, a solder resist layer 65 is provided to cover the portion of the first outer circuit layer 410 corresponding to the non-heat dissipation area 103 and the portion of the second outer circuit layer 430 corresponding to the non-heat dissipation area 103.

[0092] The first window 310 and the second window 330 can be formed by means of, but not limited to, laser cutting, mechanical cutting, drilling, etc.

[0093] Please see Figure 11 and Figure 12 An embodiment of this application discloses a circuit board 100 with a heat dissipation structure, comprising a coolant 50, electronic components 60, and a first outer circuit layer 410, an inner circuit substrate 10, and a second outer circuit layer 430 stacked sequentially. The inner circuit substrate 10 is divided into a heat dissipation area 101 and a non-heat dissipation area 103. The inner circuit substrate 10 includes a plurality of through-holes 105 and a first circuit layer 11 and a second circuit layer 13 spaced apart along the thickness direction on the outermost sides. Each through-hole 105 is located in the heat dissipation area 101 and penetrates the first circuit layer 11 and the second circuit layer 13 along the thickness direction. The first outer circuit layer 410 and the second outer circuit layer 430 seal the two sides of the heat dissipation area 101 spaced apart along the thickness direction to form a sealed cavity 203 corresponding to the heat dissipation area 101. The coolant 50 is contained within the sealed cavity 203. The electronic components 60 are disposed on the portion of the first outer circuit layer 410 corresponding to the heat dissipation area 101 or the portion of the second outer circuit layer 430 corresponding to the heat dissipation area 101. The coolant 50 and the vapor formed after absorbing heat directly contact and circulate with the portion of the first circuit layer 11 corresponding to the heat dissipation area 101 and the portion of the second circuit layer 13 corresponding to the heat dissipation area 101, which helps to improve heat dissipation efficiency.

[0094] In this embodiment, the lines in the first circuit layer 11 corresponding to the heat dissipation area 101 can be straight channels. The lines in the second circuit layer 13 corresponding to the heat dissipation area 101 can be bent channels. The straight channels facilitate the flow of liquid substances (e.g., coolant), while the bent channels, when serving as evaporation channels for gas, increase the contact area between the gas and the circuit, thus increasing the heat exchange area and facilitating heat removal. The specific shape of the bent channels is not limited, and may include, but is not limited to, S-shaped, wavy, or serrated shapes.

[0095] In this embodiment, the lines in the second circuit layer 13 corresponding to the heat dissipation area 101 can have a fine spacing, resulting in a high density of line distribution in the second circuit layer 13 corresponding to the heat dissipation area 101.

[0096] The inner circuit board 10 can be a two-layer circuit board, a three-layer circuit board, a four-layer circuit board, a five-layer circuit board, etc. When the inner circuit board 10 is a three-layer or higher circuit board, the inner circuit board 10 further includes at least one inner circuit layer (not shown in the figure), which is located between the first circuit layer 11 and the second circuit layer 13, and is stacked and spaced apart from the first circuit layer 11 and the second circuit layer 13 in the thickness direction.

[0097] In this embodiment, the through hole 105 is preferably a conductive hole. In some embodiments, the through hole 105 may also be a non-conductive hole.

[0098] The circuit board 100 further includes a first adhesive layer 21, a second adhesive layer 23, a first insulating layer 31, and a second insulating layer 33. The first outer circuit layer 410 is bonded to the portion of the first circuit layer 11 corresponding to the heat dissipation area 101 via the first adhesive layer 21, and is bonded to the portion of the first circuit layer 11 corresponding to the non-heat dissipation area 103 via the first insulating layer 31. The second outer circuit layer 430 is bonded to the portion of the second circuit layer 13 corresponding to the heat dissipation area 101 via the second adhesive layer 23, and is bonded to the portion of the second circuit layer 13 corresponding to the non-heat dissipation area 103 via the second insulating layer 33.

[0099] Preferably, the first adhesive layer 21 is made of a thermally conductive adhesive with good corrosion resistance. The second adhesive layer 23 is also made of a thermally conductive adhesive with good corrosion resistance.

[0100] In some embodiments, the inner circuit board 10 may undergo a surface treatment to increase surface roughness, thereby forming a capillary structure. The surface treatment may be, but is not limited to, browning.

[0101] In some embodiments, the circuit board 100 may further include a solder resist layer 65, which covers the portion of the first outer circuit layer 410 corresponding to the non-heat dissipation area 103 and the portion of the second outer circuit layer 430 corresponding to the non-heat dissipation area 103.

[0102] The circuit board with heat dissipation structure and its manufacturing method disclosed in this application allow the coolant 50 contained in the sealed cavity 203 and the vapor it generates to directly contact and circulate with the portion of the first circuit layer 11 corresponding to the heat dissipation area 101 and the portion of the second circuit layer 13 corresponding to the heat dissipation area 101, which is beneficial to improving heat dissipation efficiency and thus extending the service life of the circuit board.

[0103] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above as a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A circuit board with a heat dissipation structure, comprising a coolant and a first outer circuit layer, an inner circuit substrate, and a second outer circuit layer stacked sequentially, wherein the inner circuit substrate is divided into heat dissipation areas and non-heat dissipation areas, and the inner circuit substrate includes a plurality of through holes and a first circuit layer and a second circuit layer spaced apart along the thickness direction on the outermost side, characterized in that, Each of the vias is located in the heat dissipation area and penetrates the first circuit layer and the second circuit layer along the thickness direction. The first outer circuit layer and the second outer circuit layer seal the two sides of the heat dissipation area spaced apart along the thickness direction to form a sealed cavity corresponding to the heat dissipation area. The coolant is contained in the sealed cavity.

2. The circuit board with a heat dissipation structure as described in claim 1, characterized in that, The lines in the first circuit layer corresponding to the heat dissipation area are in straight channels, while the lines in the second circuit layer corresponding to the heat dissipation area are in bent channels.

3. The circuit board with a heat dissipation structure as described in claim 1, characterized in that, Each of the vias is a conductive via, and the surface of the inner circuit board has a capillary structure.

4. The circuit board with a heat dissipation structure as described in claim 1, characterized in that, The circuit board further includes a first adhesive layer, a second adhesive layer, a first insulating layer, and a second insulating layer. The first outer circuit layer is bonded to the portion of the first circuit layer corresponding to the heat dissipation area through the first adhesive layer, and is bonded to the portion of the first circuit layer corresponding to the non-heat dissipation area through the first insulating layer. The second outer circuit layer is bonded to the portion of the second circuit layer corresponding to the heat dissipation area through the second adhesive layer, and is bonded to the portion of the second circuit layer corresponding to the non-heat dissipation area through the second insulating layer.

5. The circuit board with a heat dissipation structure as described in claim 1, characterized in that, It also includes electronic components, which are disposed on the portion of the first outer circuit layer corresponding to the heat dissipation area or the portion of the second outer circuit layer corresponding to the heat dissipation area.

6. A method for manufacturing a circuit board with a heat dissipation structure, comprising the following steps: An inner circuit board is provided, the inner circuit board being divided into a heat dissipation area and a non-heat dissipation area, the inner circuit board including a plurality of vias and a first circuit layer and a second circuit layer spaced apart along the thickness direction and located on the outermost side, each of the vias being located in the heat dissipation area and penetrating the first circuit layer and the second circuit layer along the thickness direction. A first adhesive layer is provided on the surface of the first circuit layer that is away from the second circuit layer, corresponding to the heat dissipation area, to obtain a first intermediate structure; A first insulating layer with a first opening is provided. The first intermediate structure, the first insulating layer and a first metal foil are sequentially stacked and pressed together to obtain a second intermediate structure. The first insulating layer is bonded between the first circuit layer and the first metal foil. The first opening corresponds to the heat dissipation area of ​​the first intermediate structure. The first adhesive layer bonds the heat dissipation area and the first metal foil. The first metal foil, the first adhesive layer and the heat dissipation area form a receiving space. Coolant is injected into the containment space through the through-hole to obtain the third intermediate structure; A second adhesive layer is provided on the surface of the second circuit layer opposite to the first circuit layer, corresponding to the heat dissipation area; A second insulating layer with a second opening is provided, and a third intermediate structure with a second adhesive layer, the second insulating layer and a second metal foil are sequentially stacked and pressed together to obtain a fourth intermediate structure. The second insulating layer is bonded between the second circuit layer and the second metal foil. The second opening corresponds to the heat dissipation area. The second adhesive layer bonds the heat dissipation area and the second metal foil to seal the receiving space to form a sealed cavity. as well as The fourth intermediate structure is fabricated to form a first outer circuit layer and a second outer circuit layer, respectively, by pairing the first metal foil and the second metal foil.

7. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 6, characterized in that, Also includes: At least one electronic component is mounted on the portion of the first outer circuit layer corresponding to the heat dissipation area or on the portion of the second outer circuit layer corresponding to the heat dissipation area.

8. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 6, characterized in that, The lines in the first circuit layer corresponding to the heat dissipation area are in straight channels; the lines in the second circuit layer corresponding to the heat dissipation area are in bent channels.

9. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 6, characterized in that, In the first intermediate structure, in any direction perpendicular to the thickness direction, the periphery of the circuit of the first circuit layer having the first adhesive layer protrudes from the periphery of the corresponding first adhesive layer. When the second adhesive layer is provided, in any direction perpendicular to the thickness direction, the periphery of the circuit of the second circuit layer on which the second adhesive layer is provided protrudes from the periphery of the corresponding second adhesive layer.

10. The method for manufacturing a circuit board with a heat dissipation structure as described in claim 6, characterized in that, Before setting the first adhesive layer, the inner circuit board is further subjected to surface treatment to increase surface roughness.

Images