Circuit board
By incorporating flow channels and thermally conductive coatings within the circuit board, and utilizing a combination of easily vaporized coolant and heat dissipation holes, the problem of poor heat dissipation on the circuit board is solved, achieving efficient heat transfer and dissipation and improving the heat dissipation performance of the circuit board.
Patent Information
- Application Number
- CN202410961713.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-17
- Publication Date
- 2026-01-20
AI Technical Summary
Existing circuit boards have poor heat dissipation performance, especially in high-density and high-speed electronic products. The cooling effect of copper block heat dissipation modules gradually decreases as components heat up, resulting in ineffective heat dissipation.
A heat sink is installed inside the circuit board, and a flowable channel is set inside the heat sink. The inner wall of the channel is coated with a thermally conductive coating. The heat is absorbed by the easily vaporized coolant and dissipated through the heat dissipation holes of the second substrate. The channel bends continuously along a preset direction to increase the heat transfer area.
The heat dissipation efficiency of the circuit board is improved. The combination of flow channels and thermally conductive coating enhances the ability to transfer and dissipate heat, avoiding local overheating that could affect the lifespan of the circuit board and the normal operation of surrounding equipment.
Smart Images
Figure CN121368061A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of circuit boards, and particularly relates to a circuit board with good heat dissipation performance. BACKGROUND
[0002] With the improvement of the integration of electronic products, the volume of the circuit board (PCB) is getting smaller and smaller, the density is getting higher and higher, and the signal transmission is getting faster and faster, which leads to more and more heat generated by the circuit board when it works. If the heat is not dissipated in time, the circuit board will continue to heat up, and even fail due to overheating. The existing technology usually designs a heat dissipation module (for example, a copper block) to conduct heat, so as to conduct the heat generated by the circuit board to the heat dissipation module and thus reduce the temperature.
[0003] The current copper block embedding heat dissipation process is not very good for the heat dissipation effect of the PCB. When the components inside the PCB continue to heat up, the copper block will also continue to heat up and rise in temperature, and then the copper block will dissipate heat to the surrounding, and the cooling effect will become worse and worse, resulting in poor heat dissipation effect. SUMMARY
[0004] Therefore, the present application provides a circuit board to improve the heat dissipation effect.
[0005] An embodiment of the present application provides a circuit board, which comprises a first substrate, an electronic component, a dielectric layer, a heat dissipation member and a second substrate. The first substrate has a first recess. The electronic component is arranged in the first recess. The dielectric layer is arranged on the surface of the first substrate, and the dielectric layer has a second recess. The heat dissipation member is arranged in the second recess and corresponds to the electronic component. The heat dissipation member is provided with a flow channel, and the flow channel is continuously bent along a preset direction. The inner wall of the flow channel is provided with a heat conduction coating, and the flow channel is provided with cooling liquid which can flow in the flow channel. The second substrate is arranged on the surface of the dielectric layer away from the first substrate, and the second substrate comprises a heat dissipation hole corresponding to the heat dissipation member.
[0006] In an embodiment, the bending angle of the flow channel is 90°. The flow channel comprises a plurality of first portions and second portions which are perpendicular to each other, two adjacent first portions are connected by a second portion, and two adjacent second portions are connected by a first portion.
[0007] In an embodiment, the cooling liquid comprises one or more of ethanol, acetone and hexane.
[0008] In an embodiment, the heat conduction coating comprises one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, boron nitride and graphene.
[0009] In an embodiment, the heat dissipation member comprises one or more of copper, graphite and carbon fiber.
[0010] In an embodiment, an insulating heat dissipation layer is arranged between the electronic component and the inner wall of the first groove, and the insulating heat dissipation layer comprises one or more of polyimide, silicon nitride, and aluminum nitride.
[0011] In an embodiment, the first substrate comprises a first base material layer and a first circuit layer arranged on a surface of the first base material layer, and the first groove penetrates the first base material layer and the first circuit layer.
[0012] In an embodiment, the first substrate further comprises a third base material layer and a third circuit layer arranged on a surface of the third base material layer. The third base material layer is arranged between the first circuit layer and the third circuit layer, and the third circuit layer is electrically connected to the first circuit layer.
[0013] In an embodiment, the second substrate comprises a second base material layer and a second circuit layer arranged on a surface of the second base material layer, and the second circuit layer is electrically connected to the first circuit layer.
[0014] In an embodiment, the heat dissipation hole is provided with a heat dissipation material, and the heat dissipation material comprises copper.
[0015] The circuit board provided by the embodiment of the present application is provided with a heat dissipation member inside the circuit board, and a flow channel allowing the cooling liquid to flow is arranged inside the heat dissipation member. In addition, the inner wall of the flow channel is further provided with a heat conduction coating. Therefore, the heat generated by the electronic component can be absorbed by the heat dissipation member, and the absorbed heat can be dissipated through the heat dissipation hole of the second substrate. The cooling liquid is a liquid that can be easily vaporized by heat. After absorbing heat, the cooling liquid is vaporized and rises to the upper part of the flow channel, and then condenses and falls to the bottom of the flow channel to continue absorbing heat. The flow channel is continuously bent along a preset direction, which can increase the heat transfer area and improve the heat transfer efficiency. The heat conduction coating can more efficiently transfer heat to the heat dissipation hole, and then dissipate the heat through the heat dissipation hole. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 It is a cross-sectional view of the circuit board of an embodiment of the present application.
[0017] Figure 2 It is a cross-sectional view of the circuit board of another embodiment of the present application.
[0018] Explanation of main element symbols
[0019] Circuit board 100
[0020] First substrate 10
[0021] Electronic component 20
[0022] Dielectric layer 30
[0023] Heat dissipation member 40
[0024] Second substrate 50
[0025] First base material layer 11
[0026] First circuit layer 12
[0027] Third base material layer 13
[0028] Third circuit layer 14
[0029] Fifth base material layer 15
[0030] Fifth circuit layer 16
[0031] First recess 101
[0032] Conductive hole 102, 103
[0033] Insulating heat dissipation layer 21
[0034] Second recess 301
[0035] Flow channel 41
[0036] Thermally conductive coating 42
[0037] Cooling liquid 43
[0038] First portion 411
[0039] Second portion 412
[0040] Second base material layer 51
[0041] Second circuit layer 52
[0042] Heat dissipation hole 53
[0043] The following detailed description will further describe the embodiments of the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION
[0044] 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 the embodiments of the application belong. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the embodiments of the application. Unless otherwise noted, the specific conditions used in the examples are those that are conventional or those that are indicated by the manufacturer. Unless otherwise noted, the reagents or instruments used are conventional products that can be purchased from the market.
[0045] It should be noted that all directional indications, such as upper, lower, left, right, front, back, under, over, upper, lower, etc., are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.
[0046] It will be understood that when a layer is referred to as being "on" another layer, it can be directly on the other layer or intervening layers can also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. When an element is referred to as being "fixed to", "attached to", "connected to" or "set to" another element, it can be directly on the other element or intervening elements can also be present.
[0047] Embodiments of the present application are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the present application. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are to be expected. Thus, embodiments of the present application should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. The regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present application.
[0048] Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments can be combined with each other in the case of no conflict.
[0049] Referring to Figure 1 and Figure 2 , a circuit board 100 is provided, which includes a first substrate 10, an electronic component 20, a dielectric layer 30, a heat dissipation member 40, and a second substrate 50. The first substrate 10 is a circuit substrate formed with a circuit layer. The first substrate 10 has a first recess 101 which can be formed by recessing a surface portion of the first substrate 10 toward another surface. The electronic component 20 is disposed in the first recess 101, and the electronic component 20 can be, but is not limited to, a chip. The dielectric layer 30 is disposed on a surface of the first substrate 10, and the dielectric layer 30 has a second recess 301 which penetrates the dielectric layer 30 in a vertical direction thereof (i.e. Figure 1 and Figure 2 The heat dissipation member 40 is disposed in the second recess 301 and is disposed in correspondence with the electronic component 20, which means that the heat dissipation member 40 is disposed along a thickness direction of the circuit board 100 (i.e. Figure 1 and Figure 2The vertical projection of the electronic component 20 in the circuit board 100 at least partially overlaps (completely overlaps is the most preferred case) with the vertical projection of the heat dissipation member 40 in the thickness direction of the circuit board 100. The heat dissipation member 40 is provided with a flow channel 41 which is continuously bent along a preset direction. The inner wall of the flow channel 41 is provided with a heat-conducting coating 42, and the flow channel 41 is further provided with a cooling liquid 43 which can flow in the flow channel 41. The second substrate 50 is a circuit substrate which is provided with a circuit layer, and is arranged on the surface of the dielectric layer 30 which is away from the first substrate 10. The second substrate 50 comprises a heat dissipation hole 53 which is arranged corresponding to the heat dissipation member 40. That is, the vertical projection of the heat dissipation member 40 in the thickness direction of the circuit board 100 covers the heat dissipation hole 53.
[0050] The electronic component 20 generates a large amount of heat during the operation of the circuit board 100, and forms a hot spot in the circuit board 100. If the heat of the hot spot is not dispersed or conducted out in time, the service life of the circuit board 100 will be affected. Moreover, the temperature of the first substrate 10 and the second substrate 50 at the position corresponding to the hot spot will also rise, causing local overheating of the substrates and affecting the normal operation of other devices close to the substrates.
[0051] The circuit board 100 provided by the embodiment of the present application is provided with the heat dissipation member 40 in the circuit board 100, and the flow channel 41 which allows the cooling liquid 43 to flow is arranged in the heat dissipation member 40, and the inner wall of the flow channel 41 is further provided with the heat-conducting coating 42. Therefore, the heat generated by the electronic component 20 can be absorbed by the heat dissipation member 40, and the absorbed heat can be dissipated through the heat dissipation hole 53 of the second substrate 50. The cooling liquid 43 is a liquid which is easy to vaporize when heated. After absorbing heat, the cooling liquid 43 vaporizes, rises to the upper part of the flow channel 41, condenses and falls to the bottom of the flow channel 41, and continues to absorb heat. The flow channel 41 is continuously bent along a preset direction, which can increase the heat transfer area and improve the heat transfer efficiency. The heat-conducting coating 42 can more efficiently transfer heat to the heat dissipation hole 53, and then dissipate the heat through the heat dissipation hole 53.
[0052] In some embodiments, as shown in Figure 1 The bending angle of the flow channel 41 can be 90°. The flow channel 41 comprises a plurality of first portions 411 and second portions 412 which are perpendicular to each other, and the first portions 411 and the second portions 412 are connected in sequence. Two adjacent first portions 411 are connected by a second portion 412, and two adjacent second portions 412 are connected by a first portion 411. The plurality of first portions 411 are parallel, and the plurality of second portions 412 are parallel. Figure 1 For example, the first portion 411 can extend in the thickness direction of the circuit board 100, and the second portion 412 can extend in the length direction or the width direction (i.e., the horizontal direction in Figure 2 ). Figure 1 The shape of the flow channel 41 shown in is also called comb-shaped or city wall-shaped.
[0053] In some embodiments, as shown in FIG. 4A, the flow channel 41 can also be curved. Figure 2
[0054] In some embodiments, the cooling liquid 43 can be, but is not limited to, one or more of ethanol, acetone, hexane. The boiling point of the above-mentioned cooling liquid 43 is approximately in the range of 50-90°C, and after absorbing the heat generated by the electronic component 20 in normal operation, the temperature of the above-mentioned cooling liquid 43 can reach the boiling point and vaporize. If the boiling point of the cooling liquid 43 is too high, when the temperature of the electronic component 20 has already exceeded the normal operating temperature, the temperature of the cooling liquid 43 still cannot reach the boiling point, which will affect the heat absorption effect on the electronic component 20. The boiling point of ethanol is about 78.3°C, and under the normal operating temperature of the electronic component 20, ethanol will quickly vaporize and absorb heat. The boiling point of acetone is about 56°C, and under the normal operating temperature of the electronic component 20, acetone will easily vaporize. The boiling point of hexane is about 69°C, and under the normal operating temperature of the electronic component 20, hexane is also easily heated and vaporized.
[0055] In some embodiments, the heat-conducting coating 42 can be, but is not limited to, one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, boron nitride, graphene. The above-mentioned materials have high thermal conductivity and chemical stability, and can form a high-performance heat-conducting coating 42. Among them, graphene has very high thermal conductivity and is one of the materials with the highest thermal conductivity.
[0056] In some embodiments, the material of the heat-dissipating piece 40 can be, but is not limited to, one or more of copper, graphite, carbon fiber. In this embodiment, the material of the heat-dissipating piece 40 is copper, which is approximately in the shape of a cuboid or a cube. Further, the flow channel 41 can be formed by etching the copper. First, two copper blocks (the main body of the heat-dissipating piece 40) can be provided, and then one half of the complete flow channel 41 can be formed on each of the two copper blocks by etching. Then, the heat-conducting coating 42 can be provided (e.g., printed) on the inner wall of the flow channel 41, and the cooling liquid 43 can be poured into the flow channel 41 of one of the copper blocks. Finally, the other copper block can be joined (e.g., by welding or gluing) with the copper block containing the cooling liquid 43, so that the flow channels 41 of the upper and lower copper blocks are connected, forming the complete and connected flow channel 41 as shown in FIG. 4A, and the preparation of the heat-dissipating piece 40 is completed. Figure 1 or Figure 2
[0057] In some embodiments, as shown in FIG. 4A, the flow channel 41 can also be curved. Figure 1 and Figure 2 As shown, the first recess 101 is further provided with an insulating heat dissipation layer 21. The insulating heat dissipation layer 21 is arranged between the electronic element 20 and the inner wall of the first recess 101. The electronic element 20 is fixed in the first recess 101 through the insulating heat dissipation layer 21. The material of the insulating heat dissipation layer 21 can be, but is not limited to, one or more of polyimide, silicon nitride, and aluminum nitride. The above-mentioned materials have good heat conduction and insulation properties, and can withstand high temperature and high pressure environments.
[0058] In some embodiments, as shown in Figure 1 and Figure 2 , the first substrate 10 includes a first substrate layer 11 and a first circuit layer 12 arranged on the surface of the first substrate layer 11. The first recess 101 penetrates the first substrate layer 11 and the first circuit layer 12 along the thickness direction of the first substrate 10 (i.e. the vertical direction in Figure 1 In this embodiment, the first circuit layer 12 is arranged on the opposite surfaces of the first substrate layer 11 in the thickness direction. The two surfaces of the electronic element 20 can be flush with or slightly lower than the surfaces of the first circuit layer 12. In other embodiments, the first circuit layer 12 can also be arranged on only one surface of the first substrate layer 11.
[0059] Further, as shown in Figure 1 and Figure 2 , the first substrate 10 can further include a third substrate layer 13 and a third circuit layer 14 arranged on the surface of the third substrate layer 13. The third substrate layer 13 is arranged between the first circuit layer 12 and the third circuit layer 14, and the third circuit layer 14 is electrically connected to the first circuit layer 12 through the conductive hole 102. The electronic element 20 can be electrically connected to the third circuit layer 14.
[0060] Further, the first substrate 10 can be further laminated based on the third substrate layer 13 and the third circuit layer 14. As shown in Figure 1 and Figure 2 , the first substrate 10 can further include a fifth substrate layer 15 and a fifth circuit layer 16 arranged on the surface of the fifth substrate layer 15. The fifth substrate layer 15 is arranged between the third circuit layer 14 and the fifth circuit layer 16, and the fifth circuit layer 16 can be electrically connected to the third circuit layer 14 through the conductive hole 102. The fifth circuit layer 16 can also be connected to other electronic elements (not shown). By arranging the conductive hole 102 for electrical connection on the first substrate 10 and the heat dissipation hole 53 for heat dissipation on the second substrate 50, the functions of electrical connection and heat dissipation are realized through different holes, achieving electrical and thermal separation, thereby further improving the heat dissipation effect of the circuit board 100.
[0061] Further, the first substrate layer 11, the third substrate layer 13 and the fifth substrate layer 15 can each independently be selected from polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate two formic acid glycol ester (PEN), polydimethylsiloxane (PDMS), liquid crystal polymer (LCP), modified polyimide (MPI), and the like. The materials of the first substrate layer 11, the third substrate layer 13 and the fifth substrate layer 15 can be the same or different, which is not limited in the present application.
[0062] In some embodiments, as shown in Figure 1 and Figure 2 The second substrate 50 includes a second substrate layer 51 and a second circuit layer 52 disposed on the surface of the second substrate layer 51. In the present embodiment, the second circuit layer 52 is disposed on both surfaces of the second substrate layer 51 in the thickness direction, and one of the second circuit layers 52 is located between the second substrate layer 51 and the dielectric layer 30. In other embodiments, the second circuit layer 52 can be disposed on only one surface of the second substrate layer 51, and the second circuit layer 52 is disposed on the surface of the second substrate layer 51 facing away from the dielectric layer 30. The second circuit layers 52 on the two surfaces of the second substrate layer 51 can be electrically connected through the conductive hole 103, and the first substrate 10 and the second substrate 50 can be electrically connected through the conductive hole 103. Specifically, the first circuit layer 12, the third circuit layer 14 and the fifth circuit layer 16 on the first substrate 10 and the second circuit layer 52 on the second substrate 50 can be connected through the conductive hole 103.
[0063] In some embodiments, as shown in Figure 1 and Figure 2 The number of heat dissipation holes 53 can be multiple. The heat dissipation hole 53 can be formed by forming a blind hole (not shown in the figure, the blind hole can penetrate the second circuit layer 52 and the second substrate layer 51) on the second substrate 50, and then electroplating the blind hole with a heat dissipation material. The heat dissipation material can be, but is not limited to, copper.
[0064] Further, the material of the second substrate layer 51 can be, but is not limited to, polyimide, polyethylene terephthalate, polyethylene naphthalate two formic acid glycol ester, polydimethylsiloxane, liquid crystal polymer, modified polyimide, and the like. The material of the second substrate layer 51 can be the same as or different from the material of the substrate layer in the first substrate 10, which is not limited in the present application.
[0065] The circuit board 100 provided by the embodiment of the present application is characterized in that: a heat dissipation member 40 is arranged in the circuit board 100, and a flow channel 41 allowing the cooling liquid 43 to flow is arranged in the heat dissipation member 40, and the inner wall of the flow channel 41 is further provided with a heat conduction coating 42, so that the heat generated by the electronic component 20 can be absorbed by the heat dissipation member 40, and the absorbed heat can be dissipated through the heat dissipation holes 53 of the second substrate 50. The cooling liquid 43 is a liquid that can be easily vaporized by heat, and after absorbing heat, the cooling liquid 43 is vaporized to rise above the flow channel 41, condensed to fall to the bottom of the flow channel 41, and continues to absorb heat. The flow channel 41 is continuously bent along a preset direction, which can increase the heat transfer area and improve the heat transfer efficiency. The heat conduction coating 42 can more efficiently transfer heat to the heat dissipation holes 53, and then dissipate heat through the heat dissipation holes 53.
[0066] The above description is some specific embodiments of the present application, but in the actual application process, it cannot be limited to these embodiments only. Other modifications and changes made by those skilled in the art according to the technical concept of the present application should belong to the protection scope of the present application.
Claims
1. A circuit board, characterized in that, include: A first substrate has a first groove; An electronic component is disposed within the first groove; A dielectric layer is disposed on the surface of the first substrate, and the dielectric layer has a second groove; A heat sink is disposed in the second groove and corresponding to the electronic component. The heat sink has a flow channel, which is continuously bent along a preset direction. The inner wall of the flow channel is provided with a thermally conductive coating, and a coolant that can flow in the flow channel is provided. The second substrate is disposed on the surface of the dielectric layer opposite to the first substrate. The second substrate includes heat dissipation holes, which are provided corresponding to the heat dissipation component.
2. The circuit board as described in claim 1, characterized in that, The flow channel has a bending angle of 90° and includes multiple mutually perpendicular first and second parts. Two adjacent first parts are connected by a second part, and two adjacent second parts are connected by a first part.
3. The circuit board as described in claim 1, characterized in that, The coolant includes one or more of ethanol, acetone, and hexane.
4. The circuit board as described in claim 1, characterized in that, The thermally conductive coating includes one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, boron nitride, and graphene.
5. The circuit board as described in claim 1, characterized in that, The heat sink includes one or more of copper, graphite, and carbon fiber.
6. The circuit board as described in claim 1, characterized in that, An insulating heat dissipation layer is provided between the electronic component and the inner wall of the first groove, and the insulating heat dissipation layer includes one or more of polyimide, silicon nitride, and aluminum nitride.
7. The circuit board as described in claim 1, characterized in that, The first substrate includes a first substrate layer and a first circuit layer disposed on the surface of the first substrate layer, and the first groove penetrates the first substrate layer and the first circuit layer.
8. The circuit board as described in claim 7, characterized in that, The first substrate further includes a third substrate layer and a third circuit layer disposed on the surface of the third substrate layer. The third substrate layer is disposed between the first circuit layer and the third circuit layer, and the third circuit layer is electrically connected to the first circuit layer.
9. The circuit board as described in claim 7, characterized in that, The second substrate includes a second substrate layer and a second circuit layer disposed on the surface of the second substrate layer, wherein the second circuit layer is electrically connected to the first circuit layer.
10. The circuit board as described in claim 9, characterized in that, The heat dissipation holes are filled with heat dissipation material, which includes copper.