Printed circuit board and electronic device

Abstract

The utility model discloses a printed circuit board and an electronic device.The printed circuit board comprises a circuit board body, a graphene layer, a heat-conducting glue layer and at least one electronic device, and the graphene layer is fixedly arranged on the circuit board body; the heat-conducting glue layer is attached to one side of the graphene layer, and the electronic devices are fixedly arranged on the side, away from the graphene layer, of the heat-conducting glue layer so that heat can be conducted to the graphene layer through the heat-conducting glue layer. Through the mode, the heat dissipation efficiency of the printed circuit board can be improved, and miniaturization, light weight and long-term reliability of the printed circuit board are facilitated.

Description

Technical Field

[0001] This application applies to the field of printed circuit board technology, particularly printed circuit boards and electronic devices. Background Technology

[0002] PCB (Printed Circuit Board), also known as printed circuit board, is a widely used and important electronic component. It serves as the support for electronic components and also as the carrier for the electrical connections of electronic components.

[0003] Current solutions that utilize heat dissipation devices or metal substrates for heat dissipation often result in a significant increase in the weight and size of printed circuit boards, which is not conducive to lightweighting. Utility Model Content

[0004] This application provides a printed circuit board and an electronic device to solve the heat dissipation problem of the printed circuit board.

[0005] To address the aforementioned technical problems, this application provides a printed circuit board, comprising: a circuit board body, a graphene layer, a thermally conductive adhesive layer, and at least one electronic device. The graphene layer is fixedly disposed on the circuit board body. The thermally conductive adhesive layer is bonded to one side of the graphene layer, and each electronic device is fixedly disposed on the side of the thermally conductive adhesive layer away from the graphene layer, so as to utilize the thermally conductive adhesive layer to conduct heat to the graphene layer.

[0006] The printed circuit board also includes: multiple thermal conductive components; one side of each thermal conductive component is bonded to the side of the corresponding electronic device near the thermally conductive adhesive layer; the other side of each thermal conductive component is bonded to the side of the thermally conductive adhesive layer away from the graphene layer.

[0007] The circuit board body includes multiple stacked sub-boards, with at least one graphene layer; a graphene layer and a thermally conductive adhesive layer are sandwiched between each adjacent sub-board; and each electronic component conducts heat through the thermally conductive components and the thermally conductive adhesive layer.

[0008] The system comprises multiple stacked sub-boards, including a first sub-board and a second sub-board. A graphene layer and a thermally conductive adhesive layer are sandwiched between the first and second sub-boards. The side of the graphene layer away from the thermally conductive adhesive layer is bonded to the side of the first sub-board closer to the second sub-board. A preset position is defined on the second sub-board corresponding to the bottom position of the electronic device, and multiple blind holes with exposed thermally conductive adhesive layers are formed in the preset position. Each thermally conductive component is fixedly disposed in the corresponding blind hole to conduct heat between the electronic device and the thermally conductive adhesive layer.

[0009] The number of thermally conductive adhesive layers is at least one; each thermally conductive adhesive layer is respectively set at a preset position, and the length and width range of each thermally conductive adhesive layer is 105%-135% of the bottom length and width of the corresponding electronic device.

[0010] The graphene layer is fixed and bonded to one side of the circuit board body, the thermally conductive adhesive layer is bonded to the side of the graphene layer away from the circuit board body, and the electronic components are bonded to the side of the thermally conductive adhesive layer away from the circuit board body.

[0011] The circuit board body includes: multiple conductive layers and multiple dielectric layers that are alternately stacked and bonded together; electronic devices are wire-bonded to the corresponding conductive layers on the circuit board body.

[0012] The circuit board body has multiple vias, each of which is connected to a corresponding conductive layer to achieve interlayer interconnection. At least one hollow area is formed on the graphene layer, and the position of the hollow area corresponds to at least a portion of the vias to accommodate the vias. The size of the hollow area is greater than or equal to the size of the corresponding via, and the difference between the hollow area and the corresponding via is in the range of 0-50 micrometers.

[0013] The thickness of the thermally conductive adhesive layer ranges from 25 micrometers to 200 micrometers.

[0014] To address the aforementioned technical problems, this application also provides an electronic device, which includes a printed circuit board as described in any of the above claims.

[0015] To address the aforementioned technical problems, the printed circuit board of this application utilizes a graphene layer and a thermally conductive adhesive layer bonded together on the circuit board body for targeted heat dissipation of electronic components. Specifically, the graphene layer is fixedly disposed on the circuit board body, the thermally conductive adhesive layer is bonded to one side of the graphene layer, and the electronic components are fixedly disposed on the side of the thermally conductive adhesive layer away from the graphene layer. This allows the thermally conductive adhesive layer to conduct heat to the graphene layer, thereby utilizing the thermal conductivity of the graphene layer for heat dissipation, improving the heat dissipation efficiency of the printed circuit board for electronic components, and achieving efficient three-dimensional heat dissipation. Furthermore, the graphene layer has high thermal conductivity and low density, which does not significantly affect the weight and volume of the printed circuit board. This facilitates the miniaturization, weight reduction, and long-term reliability of the printed circuit board while ensuring its heat dissipation efficiency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the printed circuit board provided in this application;

[0017] Figure 2 This is a schematic diagram of another embodiment of the printed circuit board provided in this application. Detailed Implementation

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0019] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0020] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0021] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of an embodiment of the printed circuit board provided in this application.

[0022] The printed circuit board 100 includes: a circuit board body 140, a graphene layer 130, a thermally conductive adhesive layer 120, and at least one electronic device 110. The types of the printed circuit board 100 include, but are not limited to, conventional printed circuit boards, rigid-flex printed circuit boards, or carrier boards.

[0023] The main body of the circuit board 140 can be a multi-layer circuit board, including but not limited to 5-layer, 10-layer, 15-layer, 20-layer, or 30-layer circuit boards, etc. The specific number of layers is set according to actual needs.

[0024] The graphene layer 130 is fixedly disposed on the circuit board body 140; the graphene layer 130 is a type of graphene layer made of sp... 2Graphene is a layered structure composed of tightly packed, hybridized carbon atoms arranged in a single-layer, two-dimensional honeycomb lattice. The arrangement of carbon atoms within graphene is similar to that of a single-atom layer of graphite, with sp2 hybrid orbitals forming bonds. It exhibits the following characteristics: carbon atoms have four valence electrons, three of which form sp2 bonds; each carbon atom contributes one unbonded electron in a pz orbital. The pz orbitals of neighboring atoms, perpendicular to the plane, can form π bonds, which are partially filled. Studies have confirmed that the coordination number of carbon atoms in graphene is 3, the bond length between any two adjacent carbon atoms is 1.42 × 10⁻¹⁰ meters, and the angle between bonds is 120°. Besides the σ bonds linking other carbon atoms to form hexagonal rings in a honeycomb structure, the pz orbitals of each carbon atom, perpendicular to the layer plane, can form large, multi-atom π bonds that span the entire layer, resulting in excellent electrical, thermal, and optical properties. Furthermore, graphene has a lower density than metal-based graphene, allowing for greater heat dissipation within a smaller volume.

[0025] In one specific application scenario, the graphene layer 130 can be fixedly disposed on the outer surface of the circuit board body 140 for heat dissipation. In another specific application scenario, the graphene layer 130 can also be sandwiched inside the circuit board body 140 to dissipate heat from the sides. The specific location of the graphene layer 130 can be set based on actual heat dissipation requirements.

[0026] The number of graphene layers 130 on the printed circuit board 100 can be one or more, depending on the actual heat dissipation requirements.

[0027] The thermally conductive adhesive layer 120 is bonded to one side of the graphene layer 130. The thermally conductive adhesive layer 120 is formed by adding fillers such as ceramic powder or thermally conductive materials, primarily silicone, epoxy resin, or polyimide adhesive. The thermally conductive adhesive layer 120 includes, but is not limited to, silicone thermally conductive adhesive layers, epoxy resin layers, and polyurethane layers.

[0028] The electronic device 110 is fixedly disposed on the side of the thermally conductive adhesive layer 120 away from the graphene layer 130, so that the thermally conductive adhesive layer 120 conducts heat to the graphene layer 130, and then the thermal conductivity of the graphene layer 130 is used for heat dissipation, thereby improving the heat dissipation efficiency of the printed circuit board 100 for the electronic device 110.

[0029] Electronic devices 110 include, but are not limited to, various power devices, chips, and other devices that generate significant heat. The number of electronic devices 110 can be one or more, depending on actual needs, and is not specifically limited here. The heat dissipation scheme of this embodiment is scalable; it can support heat dissipation for multiple electronic devices 110, or it can deploy graphene layers 130 at different levels for heat dissipation.

[0030] In a specific application scenario, electronic device 110 can be fixedly and attached to the side of thermally conductive adhesive layer 120 away from graphene layer 130, so that heat can be directly conducted from thermally conductive adhesive layer 120 to graphene layer 130, and then the thermal conductivity of graphene layer 130 can be used for heat dissipation, thereby improving the heat dissipation efficiency of printed circuit board 100 for electronic device 110. In another specific application scenario, electronic device 110 can also contact the side of thermally conductive adhesive layer 120 away from graphene layer 130 through a thermally conductive component, that is, the thermally conductive component is disposed between electronic device 110 and thermally conductive adhesive layer 120, so that heat can be conducted from the thermally conductive component and thermally conductive adhesive layer 120 to graphene layer 130, and then the thermal conductivity of graphene layer 130 can be used for heat dissipation, thereby improving the heat dissipation efficiency of printed circuit board 100 for electronic device 110 and meeting the corresponding installation requirements of electronic device 110. The specific configuration is based on actual needs.

[0031] Through the above structure, the printed circuit board of this embodiment achieves targeted heat dissipation for electronic devices by setting a graphene layer and a thermally conductive adhesive layer bonded together on the main body of the circuit board. Specifically, the graphene layer is fixedly set on the main body of the circuit board, the thermally conductive adhesive layer is bonded to one side of the graphene layer, and the electronic devices are fixedly set on the side of the thermally conductive adhesive layer away from the graphene layer. This allows the thermally conductive adhesive layer to conduct heat to the graphene layer, thereby utilizing the thermal conductivity of the graphene layer for heat dissipation, improving the heat dissipation efficiency of the printed circuit board for electronic devices, and achieving efficient three-dimensional heat dissipation. Furthermore, the graphene layer has high thermal conductivity and low density, which does not significantly affect the weight and volume of the printed circuit board. Therefore, while ensuring the heat dissipation efficiency of the printed circuit board, it is convenient for miniaturization, weight reduction, and long-term reliability of the printed circuit board.

[0032] In other embodiments, the circuit board body 140 includes a plurality of stacked sub-boards (not shown), and the number of graphene layers 130 is at least one; a graphene layer 130 and a thermally conductive adhesive layer 120 are sandwiched between each adjacent sub-board; each electronic device 110 conducts heat through a thermally conductive component and a thermally conductive adhesive layer 120 to compensate for the positional difference between the electronic device 110 and the graphene layer 130.

[0033] Please see Figure 2 , Figure 2 This is a schematic diagram of another embodiment of the printed circuit board provided in this application. This embodiment is illustrated by taking a single graphene layer disposed within the circuit board body as an example. When multiple graphene layers are disposed within the circuit board body or when graphene layers are disposed on the surface of the circuit board body, the corresponding connections are similar to those in this embodiment and will not be described again.

[0034] The printed circuit board 200 of this embodiment includes: a circuit board body 240, a graphene layer 230, a thermally conductive adhesive layer 220, and at least one electronic device 210. The graphene layer 230 is fixedly disposed on the circuit board body 240; the thermally conductive adhesive layer 220 is bonded to one side of the graphene layer 230; the electronic device 210 is fixedly disposed on the side of the thermally conductive adhesive layer 220 away from the graphene layer 230, so that heat can be conducted to the graphene layer 230 by the thermally conductive adhesive layer 220.

[0035] The printed circuit board 200 also includes: a plurality of thermal conductive elements 250; one side of each thermal conductive element 250 is bonded to the side of the corresponding electronic device 210 near the thermally conductive adhesive layer 220; the other side of each thermal conductive element 250 is bonded to the side of the thermally conductive adhesive layer 220 away from the graphene layer. The thermal conductive elements 250 are used to conduct heat at high speed between the electronic device 210 and the thermally conductive adhesive layer 220.

[0036] The thermal conductive components 250 include, but are not limited to, metals such as copper, gold, silver, iron, or aluminum, thermally conductive silicone, boron nitride, aluminum nitride, etc.

[0037] In a specific application scenario, if the graphene layer 230 is disposed within the circuit board body 240 and the electronic device 210 is disposed on the surface of the circuit board body 240, a heat-conducting component 250 needs to be disposed between the two to compensate for the positional difference and facilitate heat conduction between them. The heat-conducting component 250 can be formed by drilling and electroplating holes at corresponding locations on the circuit board body 240 before installing the electronic device 210, thus forming a heat-conducting component 250 in the form of electroplated blind holes. This achieves heat conduction without adding any extra fabrication steps.

[0038] When the printed circuit board 200 is in operation, the heat generated by the electronic device 210 is conducted to the graphene layer 230 through the thermal conductive component 250 and the thermal conductive adhesive layer 220, and then diffused into the air from the side of the graphene layer 230, thereby achieving heat dissipation for the printed circuit board 200, especially the electronic device 210.

[0039] The graphene layer 230, disposed within the circuit board body 240, can improve the overall heat dissipation efficiency of the printed circuit board 200. If the graphene layer 230 is disposed on the surface of the circuit board body 240 and directly bonded to the electronic device 210, targeted and concentrated heat dissipation can be achieved for high-power devices like the electronic device 210, thereby improving its heat dissipation efficiency. The specific placement of the graphene layer 230 is based on heat dissipation requirements. In other embodiments, if the graphene layer 230 is disposed on the surface of the circuit board body 240, a heat-conducting component 250 may not be required between it and the electronic device 210; the two can be directly bonded together.

[0040] In some embodiments, the circuit board body 240 includes a first sub-board 241 and a second sub-board 242; a graphene layer 230 and a thermally conductive adhesive layer 220 are sandwiched between the first sub-board 241 and the second sub-board 242; wherein, the side of the graphene layer 230 away from the thermally conductive adhesive layer 220 is bonded to the side of the first sub-board 241 near the second sub-board 242, that is, the side of the thermally conductive adhesive layer 220 away from the graphene layer 230 is bonded to the side of the second sub-board 242 near the first sub-board 241.

[0041] The area on the second sub-board 242 corresponding to the bottom position of the electronic device 210 is a preset position 211. Multiple blind holes (not shown in the figure) exposing thermally conductive adhesive layers 220 are formed in the preset position 211. Each thermally conductive component 250 is fixedly disposed within its corresponding blind hole to conduct heat between the electronic device 210 and the thermally conductive adhesive layer 220. The number of thermally conductive components 250 in each preset position 211 can be 2, 3, 4, or 5, etc., depending on actual needs and is not limited here.

[0042] In a specific application scenario, if multiple electronic devices 210 are provided on the printed circuit board 200, then multiple preset positions 211 are also provided. Multiple blind holes of exposed thermally conductive adhesive layer 220 are formed on each preset position 211 to provide thermal conductive components 250.

[0043] In some embodiments, the number of thermally conductive adhesive layers 220 is at least one; the number of thermally conductive adhesive layers 220 may correspond to the number of electronic devices 210, so that they correspond one-to-one in position. Each thermally conductive adhesive layer 220 is respectively disposed at a preset position 211, and the length and width range of each thermally conductive adhesive layer 220 are 105%-135% of the bottom length and width of the corresponding electronic device 210, specifically 105%, 110%, 115%, 120%, 125%, 131%, or 135%, etc. Within this range, the thermally conductive adhesive layers 220 can concentrate and completely conduct the heat of the electronic device 210 to the graphene layer 230.

[0044] In a specific application scenario, the number of thermally conductive adhesive layers 220 can also be one. One thermally conductive adhesive layer 220 covers the entire graphene layer 230 for heat conduction, but space needs to be left on the thermally conductive adhesive layer 220 to allow the through hole 243 to pass through.

[0045] In some embodiments, the circuit board body 240 includes: multiple conductive layers 244 and multiple dielectric layers 245 that are alternately stacked and bonded together; the electronic device 210 is bonded to the corresponding conductive layer 244 on the circuit board body 240 via leads 212, the number of leads 212 being one or more. Conductive lines are formed on the conductive layer 244 to realize the electrical function of the printed circuit board 200; the dielectric layer 245 may include one or more insulating materials selected from prepreg, epoxy resin, polyester resin (PET), polyimide, polyimide, polycarbonate (PC), bismaleimide triazine (BT), ceramic matrix, etc.

[0046] The specific number of conductive layer 244 and dielectric layer 245 can be set based on actual needs.

[0047] In some embodiments, the circuit board body 240 is provided with a plurality of vias 243, each via 243 being connected to a corresponding conductive layer 244 to achieve interlayer interconnection; the vias 243 are formed by drilling and electroplating to achieve metallization.

[0048] At least one hollow region 260 is formed on the graphene layer 230, and the position of the hollow region 260 corresponds to at least part of the through hole 243 to accommodate the corresponding through hole 243.

[0049] In some embodiments, the size of the cutout region 260 is greater than or equal to the size of the corresponding via 243, and the difference between the cutout region 260 and the corresponding via 243 ranges from 0 to 50 micrometers, specifically 0 micrometers, 5 micrometers, 10 micrometers, 12 micrometers, 15 micrometers, 18 micrometers, 20 micrometers, 25 micrometers, 29 micrometers, 30 micrometers, 35 micrometers, 37 micrometers, 39 micrometers, 42 micrometers, 45 micrometers, 48 ​​micrometers, or 50 micrometers. A cutout region 260 within this range can reduce stress expansion between itself and the via 243, improving the structural stability of the printed circuit board 200.

[0050] In some embodiments, the thickness of the thermally conductive adhesive layer 220 ranges from 25 micrometers to 200 micrometers, specifically 25 micrometers, 30 micrometers, 36 micrometers, 40 micrometers, 52 micrometers, 67 micrometers, 71 micrometers, 85 micrometers, 92 micrometers, 100 micrometers, 112 micrometers, 125 micrometers, 136 micrometers, 142 micrometers, 159 micrometers, 163 micrometers, 172 micrometers, 188 micrometers, 195 micrometers, or 200 micrometers.

[0051] The thermally conductive adhesive layer 220 within this range can improve the thermal conductivity between the electronic device 210 and the graphene layer 230, and also avoid excessively increasing the thickness of the printed circuit board 200, making it easier for the printed circuit board 200 to be miniaturized and lightweight.

[0052] In some embodiments, solder resist layers 270 may also be attached to opposite sides of the circuit board body 240 to provide surface insulation and prevent oxidation.

[0053] In other embodiments, the graphene layer is fixedly and adhered to one side of the circuit board body, the thermally conductive adhesive layer is adhered to the side of the graphene layer away from the circuit board body, and the electronic device is adhered to the side of the thermally conductive adhesive layer away from the circuit board body.

[0054] Through the above structure, the printed circuit board of this embodiment achieves targeted heat dissipation for electronic devices by setting a graphene layer and a thermally conductive adhesive layer bonded together on the main body of the circuit board. Specifically, the graphene layer is fixedly set on the main body of the circuit board, the thermally conductive adhesive layer is bonded to one side of the graphene layer, and the electronic devices are fixedly set on the side of the thermally conductive adhesive layer away from the graphene layer. This allows the thermally conductive adhesive layer to conduct heat to the graphene layer, thereby utilizing the thermal conductivity of the graphene layer for heat dissipation and improving the heat dissipation efficiency of the printed circuit board for electronic devices. Furthermore, the graphene layer has high thermal conductivity and low density, which does not significantly affect the weight and volume of the printed circuit board. Therefore, while ensuring the heat dissipation efficiency of the printed circuit board, it is convenient for miniaturization and weight reduction.

[0055] Based on the same concept, this application also provides an electronic device, which includes a printed circuit board as described in any of the above embodiments, thereby utilizing the thermal conductivity of the graphene layer for heat dissipation and improving the heat dissipation efficiency of the electronic device. Furthermore, the graphene layer has high thermal conductivity and low density, which does not significantly affect the weight and volume of the printed circuit board, thus facilitating the miniaturization and weight reduction of the printed circuit board while ensuring its heat dissipation efficiency.

[0056] Electronic devices include any electronic components containing printed circuit boards.

[0057] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A printed circuit board, characterized in that, The printed circuit board includes: Circuit board body; A graphene layer is fixedly disposed on the circuit board body; A thermally conductive adhesive layer is attached to one side of the graphene layer; At least one electronic device, each of which is fixedly disposed on the side of the thermally conductive adhesive layer away from the graphene layer, so as to utilize the thermally conductive adhesive layer to conduct heat to the graphene layer.

2. The printed circuit board according to claim 1, characterized in that, The printed circuit board also includes: multiple heat-conducting components; One side of each of the thermally conductive components is bonded to the side of the corresponding electronic device that is close to the thermally conductive adhesive layer; The other side of each of the thermally conductive components is attached to the side of the thermally conductive adhesive layer away from the graphene layer.

3. The printed circuit board according to claim 2, characterized in that, The circuit board body includes multiple stacked sub-boards, and the number of graphene layers is at least one. Each adjacent sub-board is sandwiched between a graphene layer and a thermally conductive adhesive layer. Each electronic component conducts heat through the thermally conductive component and the thermally conductive adhesive layer.

4. The printed circuit board according to claim 3, characterized in that, The plurality of stacked sub-plates include a first sub-plate and a second sub-plate; The graphene layer and the thermally conductive adhesive layer are sandwiched between the first sub-board and the second sub-board; wherein, the side of the graphene layer away from the thermally conductive adhesive layer is bonded to the side of the first sub-board closer to the second sub-board. The area on the second sub-board corresponding to the bottom position of the electronic device is a preset position, and multiple blind holes with exposed thermally conductive adhesive layers are formed in the preset position; Each of the aforementioned thermal conductive elements is fixedly disposed within the corresponding blind hole to conduct heat between the electronic device and the thermally conductive adhesive layer.

5. The printed circuit board according to claim 4, characterized in that, The number of the thermally conductive adhesive layers is at least one; Each of the thermally conductive adhesive layers is respectively disposed at the preset position, and the length and width range of each of the thermally conductive adhesive layers are 105%-135% of the bottom length and width of the corresponding electronic device.

6. The printed circuit board according to claim 1, characterized in that, The graphene layer is fixedly and adhered to one side of the circuit board body, the thermally conductive adhesive layer is adhered to the side of the graphene layer away from the circuit board body, and the electronic device is adhered to the side of the thermally conductive adhesive layer away from the circuit board body.

7. The printed circuit board according to claim 1, characterized in that, The circuit board body includes: multiple conductive layers and multiple dielectric layers that are alternately stacked and bonded together in sequence; The electronic device is wire-bonded to the corresponding conductive layer on the circuit board body.

8. The printed circuit board according to claim 7, characterized in that, The circuit board body is provided with multiple through holes, and each through hole is connected to a corresponding conductive layer to achieve interlayer interconnection. At least one hollow area is formed on the graphene layer, and the position of the hollow area corresponds to at least a portion of the through holes to accommodate the corresponding through holes. The size of the hollowed-out area is greater than or equal to the size of the corresponding through hole, and the difference between the hollowed-out area and the corresponding through hole is in the range of 0-50 micrometers.

9. The printed circuit board according to claim 1, characterized in that, The thickness of the thermally conductive adhesive layer ranges from 25 micrometers to 200 micrometers.

10. An electronic device, characterized in that, The electronic device includes a printed circuit board as described in any one of claims 1-9.

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