A circuit board with thermal management function

Abstract

This invention provides a circuit board with thermal management function, including a substrate, a copper foil layer, and a heat sink. The copper foil layer is disposed on the upper surface of the substrate, and the heat sink is disposed on the lower surface of the substrate. A gradient composite buffer layer is disposed between the substrate and the heat sink. The gradient composite buffer layer consists of, from bottom to top: a ceramic transition layer, a flexible graphite layer, and a metal-based composite layer. Dynamic airflow guiding fin structures are disposed on opposite sides of the lower surface of the heat sink. Each dynamic airflow guiding fin structure includes a main fin and adjustable sub-fins. The adjustable sub-fins are hinged to opposite sides of the top of the main fin via hinges. A NiTi-based shape memory alloy is disposed between the adjustable sub-fins and the main fins. A phase change capsule filling layer is embedded within the heat sink. This effectively mitigates the difference in thermal expansion coefficients between different materials and reduces interfacial thermal stress.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, and in particular to a circuit board with thermal management function. Background Technology

[0002] Chinese patent announcement number CN222869125U, published on May 13, 2025, discloses a thermal management optimized circuit board, comprising: a substrate, a copper foil layer on one side of the substrate, a heat sink embedded on the other side of the substrate, multiple cooling mechanisms on the heat sink, a first air duct within each cooling mechanism, a piezoelectric thin film inside the first air duct, an electromagnetic coil at the air inlet of the first air duct, and a first metal thin film on the other side of the electromagnetic coil. This allows for more flexible and precise control of airflow and heat transfer processes using the piezoelectric effect and electromagnetic control, achieving excellent heat dissipation within a limited space. However, in practical use, this existing technology has a drawback: the single metal heat sink is directly connected to the substrate, posing a risk of thermal expansion coefficient mismatch, thus reducing heat dissipation efficiency. Therefore, improvement is urgently needed. Utility Model Content

[0003] Based on this, the purpose of this utility model is to provide a circuit board with thermal management function, which can effectively alleviate the difference in thermal expansion coefficient between different materials, reduce interfacial thermal stress, improve heat dissipation efficiency, and thus improve service life.

[0004] This utility model provides a circuit board with thermal management function, including a substrate, a copper foil layer, and a heat sink. The copper foil layer is disposed on the upper surface of the substrate, and the heat sink is disposed on the lower surface of the substrate. A gradient composite buffer layer is disposed between the substrate and the heat sink. The gradient composite buffer layer consists of, from bottom to top, a ceramic transition layer, a flexible graphite layer, and a metal-based composite layer. Dynamic airflow guiding fin structures are disposed on opposite sides of the lower surface of the heat sink. The dynamic airflow guiding fin structure includes a main fin and adjustable sub-fins. The adjustable sub-fins are respectively hinged to opposite sides of the top of the main fin by hinges. A NiTi-based shape memory alloy is disposed between the adjustable sub-fins and the main fins. A phase change capsule filling layer is embedded in the heat sink.

[0005] Preferably, the ceramic transition layer is made of AlN or Si3N4 material, with a thickness of 0.1-0.3 mm, a thermal conductivity ≥150 W / m·K, and a coefficient of thermal expansion matching that of the copper foil layer; the density of the flexible graphite layer is set to 1.8-2.2 g / cm³. 3The porosity is 30-50%, the flexural modulus is ≤5GPa, and the transverse thermal conductivity is ≥300W / m·K; the metal matrix composite layer is set as AlSiC or Cu-Mo composite material with a thickness of 0.5-1.0mm and laser-etched microgrooves on the surface with a groove depth of 50-100μm and a groove width of 20-50μm.

[0006] Preferably, the main fin has a height of 5-10 mm, a thickness of 0.5-1.0 mm, and a surface textured with biomimetic shark skin grooves; the adjustable sub-fin has an unfolding angle of 0°-60°, a trigger temperature of 45℃±2℃, and a response time of ≤2s.

[0007] Preferably, the phase change capsule filling layer comprises a microcapsule shell, a phase change core material, and a thermally conductive reinforcing network; the microcapsule shell is a SiO2 / polyurethane composite material with a wall thickness of 10-50 nm, a diameter of 0.2-0.5 mm, and a compressive strength ≥50 MPa; the phase change core material is a paraffin-CNT composite with a CNT content of 5-15 wt%, a latent heat of phase change ≥200 J / g, and a thermal conductivity ≥5 W / m·K; the thermally conductive reinforcing network is a three-dimensional graphene framework with a porosity of 70-90% and a density of 0.1-0.3 g / cm³. 3 A continuous heat conduction path is formed throughout the capsule layer, with a network thermal conductivity ≥500W / m·K; the phase change capsule filling layer has a filling density of 200-500 capsules / cm³. 3 Thermal response time ≤10s, transient temperature rise rate ≤5℃ / s.

[0008] Preferably, the device further includes an electromagnetic eddy current suppression ring, which is embedded in the surface of the gradient composite layer. The electromagnetic eddy current suppression ring comprises a ferrite-based soft magnetic ring and a copper shielding mesh. The initial permeability μ_i of the ferrite-based soft magnetic ring is ≥5000, the Curie temperature is ≥150℃, and the ratio of the inner diameter of the ring to the diagonal length of the heat sink is 1:1.2-1:1.5. The copper shielding mesh has a mesh count of 100-200, a wire diameter of 0.05-0.1mm, a coverage of ≥80%, and a surface silver plating thickness of 1-2μm.

[0009] Preferably, the outer surface of the heat sink is coated with a thermochromic warning coating.

[0010] The beneficial effects of this utility model are as follows:

[0011] 1. Through the sandwich structure of ceramic transition layer, flexible graphite layer and metal matrix composite layer, the difference in thermal expansion coefficient between different materials is effectively alleviated, the interfacial thermal stress is reduced, and a continuous and efficient heat conduction path is established to improve heat dissipation uniformity.

[0012] 2. The biomimetic groove texture on the surface of the main fin, combined with the temperature-adaptive deployment of the adjustable sub-fins, significantly enhances airflow disturbance efficiency, reduces turbulence noise, and achieves quiet and efficient heat dissipation.

[0013] 3. A phase change capsule filling layer is set up. By using microcapsules to encapsulate phase change materials and a three-dimensional graphene thermally conductive network, transient heat is quickly absorbed and diffused, local temperature rise rate is suppressed, and the life of electronic components is extended.

[0014] 4. Electromagnetic eddy current suppression ring: The composite design of ferrite soft magnetic ring and high-density copper shielding mesh effectively suppresses high-frequency electromagnetic interference and low-frequency eddy current loss, ensuring stable circuit operation.

[0015] 5. Install a thermochromic warning coating: Through visual temperature zone display and fluorescent marking, non-contact hotspot location can be achieved, which can significantly shorten the troubleshooting time and improve equipment maintenance efficiency. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the present invention.

[0017] The attached figures are labeled as follows: substrate 10, heat sink 12, copper foil layer 11, ceramic transition layer 15, flexible graphite layer 14, metal-based composite layer 13, gradient composite buffer layer 16, main fin 17, adjustable sub-fin 18, hinge 19, and dynamic airflow guiding fin structure 20. Detailed Implementation

[0018] To further understand the features, technical means, and specific objectives and functions achieved by this utility model, the following detailed description of this utility model is provided in conjunction with specific embodiments and accompanying drawings.

[0019] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0020] Please refer to Figure 1As shown, this utility model provides a circuit board with thermal management function, including a substrate 10, a copper foil layer 11, and a heat sink 12. The copper foil layer 11 is disposed on the upper surface of the substrate 10, and the heat sink 12 is disposed on the lower surface of the substrate 10. A gradient composite buffer layer 16 is disposed between the substrate 10 and the heat sink 12. The gradient composite buffer layer 16 consists of, from bottom to top, a ceramic transition layer 15, a flexible graphite layer 14, and a metal-based composite layer 13. Dynamic airflow guiding fin structures 20 are disposed on opposite sides of the lower surface of the heat sink 12. The dynamic airflow guiding fin structure 20 includes a main fin 17 and adjustable sub-fins 18. The adjustable sub-fins 18 are respectively hinged to opposite sides of the top of the main fin 17 by hinges 19. A NiTi-based shape memory alloy is disposed between the adjustable sub-fins 18 and the main fin 17. A phase change capsule filling layer is embedded in the heat sink 12.

[0021] In a preferred embodiment, the ceramic transition layer 15 is made of AlN or Si3N4 material, with a thickness of 0.1-0.3 mm, a thermal conductivity ≥150 W / m·K, and a coefficient of thermal expansion matching that of the copper foil layer 11; the density of the flexible graphite layer 14 is set to 1.8-2.2 g / cm³. 3 The porosity is 30-50%, the flexural modulus is ≤5GPa, and the transverse thermal conductivity is ≥300W / m·K; the metal matrix composite layer 13 is set as AlSiC or Cu-Mo composite material with a thickness of 0.5-1.0mm and laser-etched microgrooves on the surface with a groove depth of 50-100μm and a groove width of 20-50μm.

[0022] In a preferred embodiment, the main fin 17 has a height of 5-10 mm, a thickness of 0.5-1.0 mm, and a biomimetic shark skin groove texture on its surface; the adjustable sub-fin 18 has an unfolding angle of 0°-60°, a trigger temperature of 45℃±2℃, and a response time of ≤2s.

[0023] In a preferred embodiment, the phase change capsule filling layer comprises a microcapsule shell, a phase change core material, and a thermally conductive reinforcing network; the microcapsule shell is a SiO2 / polyurethane composite material with a wall thickness of 10-50 nm, a diameter of 0.2-0.5 mm, and a compressive strength ≥50 MPa; the phase change core material is a paraffin-CNT composite with a CNT content of 5-15 wt%, a latent heat of phase change ≥200 J / g, and a thermal conductivity ≥5 W / m·K; the thermally conductive reinforcing network is a three-dimensional graphene framework with a porosity of 70-90% and a density of 0.1-0.3 g / cm³. 3 A continuous heat conduction path is formed throughout the capsule layer, with a network thermal conductivity ≥500W / m·K; the phase change capsule filling layer has a filling density of 200-500 capsules / cm³. 3 Thermal response time ≤10s, transient temperature rise rate ≤5℃ / s.

[0024] In a preferred embodiment, an electromagnetic eddy current suppression ring is further included. The electromagnetic eddy current suppression ring is embedded in the surface of the gradient composite layer. The electromagnetic eddy current suppression ring includes a ferrite-based soft magnetic ring and a copper shielding mesh. The initial permeability μ_i of the ferrite-based soft magnetic ring is ≥5000, the Curie temperature is ≥150℃, and the ratio of the inner diameter of the ring to the diagonal length of the heat sink is 1:1.2-1:1.5. The copper shielding mesh has a mesh count of 100-200, a wire diameter of 0.05-0.1mm, a coverage of ≥80%, and a surface silver plating thickness of 1-2μm.

[0025] As a preferred embodiment, the outer surface of the heat sink is coated with a thermochromic warning coating.

[0026] In this embodiment, a sandwich structure consisting of a ceramic transition layer, a flexible graphite layer, and a metal-based composite layer effectively mitigates the differences in thermal expansion coefficients between different materials, reduces interfacial thermal stress, and establishes a continuous and efficient heat conduction path, improving heat dissipation uniformity. The biomimetic groove texture on the main fin surface, combined with the temperature-adaptive deployment of adjustable sub-fins, significantly enhances airflow disturbance efficiency, reduces turbulence noise, and achieves quiet and efficient heat dissipation. A phase change capsule filling layer is incorporated, utilizing the synergistic effect of microencapsulated phase change materials and a three-dimensional graphene thermally conductive network to rapidly absorb and diffuse transient heat, suppressing local temperature rise rates and extending the lifespan of electronic components. An electromagnetic eddy current suppression ring is installed: a composite design of a ferrite soft magnetic ring and a high-density copper shielding mesh effectively suppresses high-frequency electromagnetic interference and low-frequency eddy current losses, ensuring stable circuit operation. A thermochromic warning coating is applied: through visual temperature zone display and fluorescent marking, non-contact hotspot location is achieved, significantly shortening fault diagnosis time and improving equipment maintenance efficiency.

[0027] The above-described embodiments are merely one implementation of this utility model, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A circuit board with thermal management function, comprising a substrate (10), a copper foil layer (11), and a heat sink (12), wherein the copper foil layer (11) is disposed on the upper surface of the substrate (10), and the heat sink (12) is disposed on the lower surface of the substrate (10), characterized in that, A gradient composite buffer layer (16) is provided between the substrate (10) and the heat sink (12); the gradient composite buffer layer (16) consists of, from bottom to top: a ceramic transition layer (15), a flexible graphite layer (14), and a metal-based composite layer (13); dynamic airflow guiding fin structures (20) are provided on opposite sides of the lower surface of the heat sink (12), the dynamic airflow guiding fin structure (20) includes a main fin (17) and adjustable sub-fins (18), the adjustable sub-fins (18) are respectively hinged to opposite sides of the top of the main fin (17) by hinges (19), and a NiTi-based shape memory alloy is provided between the adjustable sub-fins (18) and the main fin (17); a phase change capsule filling layer is embedded in the heat sink (12).

2. The circuit board with thermal management function according to claim 1, characterized in that: The ceramic transition layer (15) is made of AlN or Si3N4 material, with a thickness of 0.1-0.3 mm, a thermal conductivity ≥150 W / m·K, and a coefficient of thermal expansion matching that of the copper foil layer (11); the density of the flexible graphite layer (14) is set to 1.8-2.2 g / cm³. 3 The porosity is 30-50%, the flexural modulus is ≤5GPa, and the transverse thermal conductivity is ≥300W / m·K; the metal matrix composite layer (13) is set as AlSiC or Cu-Mo composite material with a thickness of 0.5-1.0mm, and the surface is laser-etched with microgrooves with a groove depth of 50-100μm and a groove width of 20-50μm.

3. A circuit board with thermal management function according to claim 1, characterized in that: The main fin (17) has a height of 5-10 mm, a thickness of 0.5-1.0 mm, and a biomimetic shark skin groove texture on its surface; the adjustable sub-fin (18) has an unfolding angle of 0°-60°, a trigger temperature of 45℃±2℃, and a response time of ≤2s.

4. A circuit board with thermal management function according to claim 1, characterized in that: The phase change capsule filling layer comprises a microcapsule shell, a phase change core material, and a thermally conductive reinforcing network. The microcapsule shell is a SiO2 / polyurethane composite material with a wall thickness of 10-50 nm, a diameter of 0.2-0.5 mm, and a compressive strength ≥50 MPa. The phase change core material is a paraffin-CNT composite with a CNT content of 5-15 wt%, a latent heat of phase change ≥200 J / g, and a thermal conductivity ≥5 W / m·K. The thermally conductive reinforcing network is a three-dimensional graphene framework with a porosity of 70-90% and a density of 0.1-0.3 g / cm³. 3 A continuous heat conduction path is formed throughout the capsule layer, with a network thermal conductivity ≥500W / m·K; the phase change capsule filling layer has a filling density of 200-500 capsules / cm³. 3 Thermal response time ≤10s, transient temperature rise rate ≤5℃ / s.

5. A circuit board with thermal management function according to claim 1, characterized in that: It also includes an electromagnetic eddy current suppression ring, which is embedded in the surface of the gradient composite layer. The electromagnetic eddy current suppression ring includes a ferrite-based soft magnetic ring and a copper shielding mesh. The initial permeability μ_i of the ferrite-based soft magnetic ring is ≥5000, the Curie temperature is ≥150℃, and the ratio of the inner diameter of the ring to the diagonal length of the heat sink is 1:1.2-1:1.

5. The copper shielding mesh has a mesh count of 100-200, a wire diameter of 0.05-0.1mm, a coverage of ≥80%, and a surface silver plating thickness of 1-2μm.

6. A circuit board with thermal management function according to claim 1, characterized in that: The outer surface of the heat sink is coated with a thermochromic warning coating.

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