Multilayer wiring board structure facilitating heat dissipation
Patent Information
- Application Number
- CN202522088704.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2035-09-28
AI Technical Summary
[0004]本实用新型的目的在于提供便于散热的多层线路板结构，以解决上述背景技术提出的目前市场上现有多层线路板散热效率低、易出现热量堆积的问题
（1）该便于散热的多层线路板结构，通过设置第一散热层和第二散热层，并采用铜-铝复合板材制作，铜-铝复合板材兼具铜的高导热性和铝的轻量化特点，能快速吸收线路板各层产生的热量；同时，散热层内部的散热通孔配合内壁的石墨烯散热涂层，进一步提高了热量的传导和散发效率，有效避免热量在层间堆积；
Smart Images
Figure CN224818277U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of circuit board technology, specifically to a multi-layer circuit board structure that facilitates heat dissipation. Background Technology
[0002] As electronic devices develop towards miniaturization and high integration, multilayer circuit boards are widely used because they can effectively increase circuit density and reduce device size. However, the increased power density brought about by high integration causes the circuit board to generate a lot of heat during operation. If the heat cannot be dissipated in time, it will cause the circuit board temperature to rise, which will not only affect the working stability and lifespan of electronic components, but also cause the circuit board to burn out and cause equipment failure in severe cases. Existing heat dissipation methods for multilayer circuit boards mostly rely on setting heat sinks on the surface of the circuit board or using substrates with good heat dissipation performance. However, these methods have problems such as low heat dissipation efficiency, complex structure, and increased overall thickness of the circuit board. For example, the layers of traditional multilayer circuit boards are usually only connected by an insulating layer, making it difficult for heat to be quickly conducted and dissipated between the layers, resulting in heat accumulation in local areas. At the same time, the design of heat dissipation channels on the circuit board is unreasonable, which further reduces the heat dissipation effect.
[0003] Therefore, we proposed a multilayer circuit board structure that facilitates heat dissipation to solve the problems mentioned above. Utility Model Content
[0004] The purpose of this invention is to provide a multilayer circuit board structure that facilitates heat dissipation, thereby solving the problems of low heat dissipation efficiency and easy heat accumulation in existing multilayer circuit boards on the market as mentioned in the background art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: a multi-layer circuit board structure that facilitates heat dissipation, comprising a top circuit layer, a first heat dissipation layer, an intermediate circuit layer, a second heat dissipation layer, and a bottom circuit layer arranged sequentially from top to bottom, wherein the top circuit layer, the first heat dissipation layer, the intermediate circuit layer, the second heat dissipation layer, and the bottom circuit layer are all fixedly connected by an insulating adhesive layer. Both the first heat dissipation layer and the second heat dissipation layer are made of copper-aluminum composite material. Both the first heat dissipation layer and the second heat dissipation layer have arrayed heat dissipation through holes inside. The inner wall of the heat dissipation through holes is coated with a graphene heat dissipation coating. The outer surfaces of the top and bottom circuit layers are provided with heat dissipation protrusions, and the heat dissipation protrusions are integrally formed with the top and bottom circuit layers. Heat dissipation grooves are provided on both sides of the intermediate circuit layer, and the heat dissipation grooves are connected to the heat dissipation through holes on the first heat dissipation layer and the second heat dissipation layer. The insulating adhesive layer is made of thermally conductive silicone, and copper thermally conductive particles are embedded inside the insulating adhesive layer.
[0006] Preferably, the diameter of the heat dissipation through hole is 0.5-1mm, and the distance between two adjacent heat dissipation through holes is 2-3mm, so as to ensure the unobstructed heat dissipation channel and heat dissipation area.
[0007] Preferably, the height of the heat dissipation protrusion is 0.3-0.5mm, the cross-section is circular, and the distance between two adjacent heat dissipation protrusions is 1-2mm. By increasing the heat dissipation area of the outer surface of the top and bottom circuit layers, the efficiency of heat dissipation to the external environment is improved.
[0008] Preferably, the depth of the heat dissipation groove is 0.2-0.3mm and the width is 0.8-1.2mm. The extension direction of the heat dissipation groove is perpendicular to the routing of the circuit on the intermediate circuit layer to avoid the heat dissipation groove affecting the circuit layout, while ensuring that heat can be quickly conducted to the heat dissipation layer.
[0009] Preferably, the copper thermally conductive particles have a particle size of 50-100μm, and the volume ratio of the copper thermally conductive particles in the insulating adhesive layer is 15%-20%. The copper thermally conductive particles enhance the thermal conductivity of the insulating adhesive layer and promote heat transfer between layers.
[0010] Preferably, the top circuit layer, the middle circuit layer and the bottom circuit layer are all made of FR-4 epoxy resin glass cloth substrate, which ensures the structural strength and insulation performance of the circuit board while having a certain thermal conductivity.
[0011] Compared with the prior art, the beneficial effects of this utility model are: (1) The heat dissipation-friendly multilayer circuit board structure is made of copper-aluminum composite material by setting a first heat dissipation layer and a second heat dissipation layer. The copper-aluminum composite material has both the high thermal conductivity of copper and the lightweight characteristics of aluminum, which can quickly absorb the heat generated by each layer of the circuit board. At the same time, the heat dissipation through holes inside the heat dissipation layer, together with the graphene heat dissipation coating on the inner wall, further improve the heat conduction and dissipation efficiency, and effectively avoid heat accumulation between layers. (2) The heat dissipation-friendly multilayer circuit board structure has heat dissipation protrusions on the outer surfaces of the top and bottom circuit layers, which increases the contact area between the circuit board and the external environment and accelerates the dissipation of heat to the outside. The heat dissipation grooves on both sides of the middle circuit layer are connected to the heat dissipation through holes of the heat dissipation layer, forming a heat dissipation channel that runs through the multilayer circuit board, so that the heat generated by the middle circuit layer can be quickly transferred to the heat dissipation layer and then dissipated through the heat dissipation through holes and heat dissipation protrusions. (3) The heat dissipation-friendly multilayer circuit board structure has copper thermally conductive particles embedded in the insulating adhesive layer, which not only ensures the bonding strength and insulation performance between the layers, but also significantly improves the thermal conductivity between the layers, solving the problem of blocked heat transfer between layers caused by the poor thermal conductivity of the traditional insulating layer. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the exploded structure of this utility model; Figure 3 This is a schematic diagram of the heat dissipation through-hole structure of this utility model; Figure 4 This is a schematic diagram of the insulating adhesive layer structure of this utility model.
[0013] In the diagram: 1. Top circuit layer; 2. First heat dissipation layer; 3. Middle circuit layer; 4. Second heat dissipation layer; 5. Bottom circuit layer; 6. Heat dissipation via; 7. Insulating adhesive layer; 8. Copper thermally conductive particles; 9. Heat dissipation protrusion; 10. Graphene heat dissipation coating; 11. Heat dissipation groove. Detailed Implementation
[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0015] Please see Figures 1-4 The present invention provides the following technical solution: a multi-layer circuit board structure that facilitates heat dissipation, comprising a top circuit layer 1, a first heat dissipation layer 2, a middle circuit layer 3, a second heat dissipation layer 4 and a bottom circuit layer 5 arranged sequentially from top to bottom, wherein the top circuit layer 1, the first heat dissipation layer 2, the middle circuit layer 3, the second heat dissipation layer 4 and the bottom circuit layer 5 are all fixedly connected by an insulating adhesive layer 7. Furthermore, the top circuit layer 1, the middle circuit layer 3, and the bottom circuit layer 5 are all made of FR-4 epoxy resin glass cloth substrate, which ensures the structural strength and insulation performance of the circuit board while also having certain thermal conductivity. The first heat dissipation layer 2 and the second heat dissipation layer 4 are both made of copper-aluminum composite material. The interior of the first heat dissipation layer 2 and the second heat dissipation layer 4 are provided with heat dissipation through holes 6 arranged in an array. The inner wall of the heat dissipation through holes 6 is coated with a graphene heat dissipation coating 10. Furthermore, the diameter of the heat dissipation through hole 6 is 0.5-1mm, and the spacing between two adjacent heat dissipation through holes 6 is 2-3mm, so as to ensure the unobstructed heat dissipation channel and heat dissipation area. The outer surfaces of the top circuit layer 1 and the bottom circuit layer 5 are provided with heat dissipation protrusions 9, and the heat dissipation protrusions 9 are integrally formed with the top circuit layer 1 and the bottom circuit layer 5. Furthermore, the height of the heat dissipation protrusion 9 is 0.3-0.5mm, the cross-section is circular, and the distance between two adjacent heat dissipation protrusions 9 is 1-2mm. By increasing the heat dissipation area of the outer surface of the top circuit layer 1 and the bottom circuit layer 5, the efficiency of heat dissipation to the external environment is improved. Heat dissipation grooves 11 are provided on both sides of the intermediate circuit layer 3, and the heat dissipation grooves 11 are connected to the heat dissipation through holes 6 on the first heat dissipation layer 2 and the second heat dissipation layer 4. Furthermore, the depth of the heat sink 11 is 0.2-0.3mm and the width is 0.8-1.2mm. The extension direction of the heat sink 11 is perpendicular to the routing of the circuit on the intermediate circuit layer 3, so as to avoid the heat sink 11 affecting the circuit layout and ensure that heat can be quickly conducted to the heat dissipation layer. The insulating adhesive layer 7 is made of thermally conductive silicone, and copper thermally conductive particles 8 are embedded inside the insulating adhesive layer 7. Furthermore, the copper thermally conductive particles 8 have a particle size of 50-100μm and a volume ratio of 15%-20% in the insulating adhesive layer 7. The copper thermally conductive particles 8 enhance the thermal conductivity of the insulating adhesive layer 7 and promote heat transfer between layers. Specifically, during circuit board operation, the electronic components and circuits on the top circuit layer 1, middle circuit layer 3, and bottom circuit layer 5 generate heat. Part of the heat generated by the top and bottom circuit layers 1 and 5 is dissipated directly to the external environment through the integrally formed heat dissipation protrusions 9 on their outer surfaces. These protrusions 9 increase the contact area between the circuit board and the air, accelerating convection heat dissipation. The remaining heat is transferred to adjacent heat dissipation layers through the interlayer insulating adhesive layer 7. Because the middle circuit layer 3 is located inside the circuit board, heat tends to accumulate there. The heat generated by this layer is first conducted to the heat dissipation grooves 11 on both sides of the surface, temporarily storing some heat and creating conditions for subsequent conduction to the heat dissipation layers. When the heat is transferred to the insulating adhesive layer 7, the copper thermally conductive particles 8, with their high thermal conductivity, quickly dissipate the heat from the circuit... The heat is conducted from the circuit layer to the heat dissipation layer, avoiding the heat "blocking" problem caused by the poor thermal conductivity of traditional insulation layers. The first heat dissipation layer 2 and the second heat dissipation layer 4 are made of copper-aluminum composite material. Due to its high thermal conductivity, the copper layer preferentially absorbs the heat from the insulating bonding layer 7 and quickly diffuses the heat inside the heat dissipation layer. The aluminum layer, with its lightweight characteristics, assists the copper layer in heat conduction without increasing the overall weight of the circuit board. The array of heat dissipation through holes 6 opened inside the heat dissipation layer increases the inner surface area of the heat dissipation layer and accelerates the heat exchange between heat and air. On the other hand, the graphene heat dissipation coating 10 coated on the inner wall of the through holes can further enhance the heat conduction efficiency of the inner wall of the through holes, so that the heat in the heat dissipation layer can be quickly transferred to the through holes, forming a heat dissipation path of "overall heat absorption of the heat dissipation layer - concentrated heat conduction of the through holes". Heat within the heat dissipation layer is dissipated in two ways: first, the heat within the heat dissipation holes 6 is directly exchanged with the outside air through convection, achieving "internal channel heat dissipation"; second, some of the heat absorbed by the heat dissipation layer is conducted in reverse through the insulating adhesive layer 7 on the other side to the top circuit layer 1 or the bottom circuit layer 5, and then dissipated to the outside through the heat dissipation protrusions 9. At the same time, the heat in the heat dissipation grooves 11 on the middle circuit layer 3 is transferred through the insulating adhesive layer 7 to the first heat dissipation layer 2 and the second heat dissipation layer 4, and then dissipated along with the heat dissipation path of the heat dissipation layer, ultimately achieving comprehensive and rapid heat dissipation of each layer of the circuit board and avoiding local overheating. The contents not described in detail in this specification are prior art known to those skilled in the art.
[0016] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A multilayer circuit board structure for easy heat dissipation, comprising, from top to bottom, a top circuit layer (1), a first heat dissipation layer (2), an intermediate circuit layer (3), a second heat dissipation layer (4), and a bottom circuit layer (5), characterized in that: The top circuit layer (1), the first heat dissipation layer (2), the middle circuit layer (3), the second heat dissipation layer (4) and the bottom circuit layer (5) are all fixedly connected by an insulating adhesive layer (7); The first heat dissipation layer (2) and the second heat dissipation layer (4) are both made of copper-aluminum composite plate. The first heat dissipation layer (2) and the second heat dissipation layer (4) are provided with heat dissipation through holes (6) arranged in an array. The inner wall of the heat dissipation through holes (6) is coated with a graphene heat dissipation coating (10). The outer surfaces of the top circuit layer (1) and the bottom circuit layer (5) are provided with heat dissipation protrusions (9), and the heat dissipation protrusions (9) are integrally formed with the top circuit layer (1) and the bottom circuit layer (5). Heat dissipation grooves (11) are provided on both sides of the intermediate circuit layer (3), and the heat dissipation grooves (11) are connected to the heat dissipation through holes (6) on the first heat dissipation layer (2) and the second heat dissipation layer (4). The insulating adhesive layer (7) is made of thermally conductive silicone, and copper thermally conductive particles (8) are embedded inside the insulating adhesive layer (7).
2. The multilayer circuit board structure for easy heat dissipation according to claim 1, characterized in that: The diameter of the heat dissipation through hole (6) is 0.5-1mm, and the distance between two adjacent heat dissipation through holes (6) is 2-3mm.
3. The multilayer circuit board structure for easy heat dissipation according to claim 1, characterized in that: The height of the heat dissipation protrusion (9) is 0.3-0.5mm, the cross-section is circular, and the distance between two adjacent heat dissipation protrusions (9) is 1-2mm.
4. The multilayer circuit board structure for easy heat dissipation according to claim 1, characterized in that: The depth of the heat dissipation groove (11) is 0.2-0.3 mm and the width is 0.8-1.2 mm. The extension direction of the heat dissipation groove (11) is perpendicular to the line direction on the intermediate line layer (3).
5. The multilayer circuit board structure for easy heat dissipation according to claim 1, characterized in that: The copper thermally conductive particles (8) have a particle size of 50-100μm and the volume ratio of the copper thermally conductive particles (8) in the insulating adhesive layer (7) is 15%-20%.
6. The multilayer circuit board structure for easy heat dissipation according to claim 1, characterized in that: The top circuit layer (1), the middle circuit layer (3) and the bottom circuit layer (5) are all made of FR-4 epoxy resin glass cloth substrate.