Circuit board structure with multifunctional cover film

Abstract

The utility model provides a circuit board structure with a multifunctional cover film, comprising a substrate layer, a conductive layer bonded and fixed on the upper surface of the substrate layer, and a functional cover film layer, the lower surface of the substrate layer is provided with a snakelike micro-channel network, the channel of the snakelike micro-channel network is filled with a perfluoropolyether cooling liquid layer, and the perfluoropolyether cooling liquid layer is filled with a perfluoropolyether cooling liquid layer. An opening of the snakelike micro-channel network is covered with a porous ceramic sealing layer; the functional covering film layer comprises an adhesion layer, a composite insulation layer, a gradient phase change heat conduction layer and a self-repairing protection layer, the adhesion layer is attached to the lower surface of the snakelike micro-channel network, and the composite insulation layer, the gradient phase change heat conduction layer and the self-repairing protection layer sequentially cover the upper surface of the conductive layer from bottom to top. On the basis that the integrated design of heat dissipation, water resistance, corrosion resistance and electromagnetic shielding functions of the circuit board is achieved, the overall thickness is reduced, and good bending resistance is achieved.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, and in particular to a circuit board structure with a multifunctional covering film. Background Technology

[0002] Chinese Patent Publication No. CN222750633U, published on April 11, 2025, discloses a cover film for printed circuit boards, belonging to the technical field of cover film technology for printed circuit boards. This utility model includes: a core layer; an adhesive layer for adhering the cover film to the printed circuit board is fixedly connected to the bottom of the core layer; an insulating layer is fixedly connected to the upper sidewall of the core layer; a low-refractive-index colored composite material layer is fixedly connected to the upper sidewall of the insulating layer; and a protective layer is fixedly connected to the upper sidewall of the colored composite material layer. This utility model, by adding an insulating layer composed of an antistatic layer and an electromagnetic shielding layer to the upper surface of the core layer, enables the device to provide antistatic and electromagnetic interference blocking functions for the printed circuit board. The addition of a protective layer composed of a flame-retardant layer, a waterproof layer, and a wear-resistant layer provides flame-retardant, waterproof, and wear-resistant protection for the printed circuit board, enhancing functionality, improving the protection effect, and extending the service life. The existing technology has the following drawbacks: the cover film is prone to delamination and blistering under high-temperature environments, resulting in insufficient heat resistance; the electromagnetic shielding layer uses a metal alloy film, but its shielding efficiency may be insufficient in high-frequency scenarios such as 5G / millimeter-wave; the existing cover film has multiple layers, such as a core layer + insulating layer + protective layer, which increases the thickness and affects the dynamic bending performance of the flexible circuit board. Given this situation, improvements are urgently needed. Utility Model Content

[0003] Based on this, the purpose of this utility model is to provide a circuit board structure with a multifunctional covering film, which reduces the overall thickness while achieving integrated design of circuit board heat dissipation, waterproofing, corrosion resistance and electromagnetic shielding functions, and also has good bending resistance.

[0004] This utility model provides a circuit board structure with a multifunctional cover film, including a substrate layer, a conductive layer bonded and fixed to the upper surface of the substrate layer, and a functional cover film layer. A serpentine microchannel network is formed on the lower surface of the substrate layer. The channels of the serpentine microchannel network are filled with a perfluoropolyether cooling liquid layer, and the openings of the serpentine microchannel network are covered with a porous ceramic sealing layer. The functional cover film layer includes an adhesive layer, a composite insulating layer, a gradient phase change thermally conductive layer, and a self-healing protective layer. The adhesive layer is attached to the lower surface of the serpentine microchannel network, and the composite insulating layer, the gradient phase change thermally conductive layer, and the self-healing protective layer are sequentially covered on the upper surface of the conductive layer from bottom to top.

[0005] Preferably, the conductive layer includes a copper foil layer and an upper nickel-phosphorus alloy passivation layer covering the upper surface of the copper foil layer and a lower nickel-phosphorus alloy passivation layer covering the lower surface of the copper foil layer.

[0006] Preferably, the adhesive layer is a halogen-free epoxy adhesive layer containing benzotriazole corrosion inhibitor.

[0007] Preferably, the composite insulating layer comprises an alternately stacked first sublayer and a second sublayer, wherein the first sublayer is configured as a silver nanowire mesh shielding layer and the second sublayer is configured as a CeO2 / SiO2 corrosion inhibitor coating.

[0008] Preferably, the gradient phase change thermal conductive layer includes a graphene substrate and a hydrophobic nickel foam layer stacked on the graphene substrate. Paraffin / boron nitride phase change microcapsules are embedded inside the graphene substrate, and the in-plane thermal conductivity direction of the graphene substrate is parallel to the surface of the substrate layer.

[0009] Preferably, the self-healing protective layer includes a PDMS matrix and a biomimetic nano-protrusion array disposed on the upper surface of the PDMS matrix. Urea-formaldehyde microcapsules are uniformly dispersed in the PDMS matrix. The shell of the urea-formaldehyde microcapsules is made of urea-formaldehyde resin, and the core material is made of hydroxyl-terminated polysiloxane.

[0010] Preferably, the conductive layer is fixed to the substrate layer by an adhesive layer, and the adhesive layer is configured as a zinc-aluminum hydrotalcite intercalation structure.

[0011] Preferably, the substrate layer is configured as a polyimide composite substrate layer, wherein a layer of strontium molybdate nanoparticles with a particle size of 20-50 nm is dispersed within the polyimide composite substrate layer.

[0012] Preferably, the phase transition temperature of the paraffin / boron nitride phase change microcapsules is 45-60℃.

[0013] Preferably, the thickness ratio of the substrate layer, the conductive layer, and the functional cover film layer is 1:0.2:0.8.

[0014] The beneficial effects of this utility model are: it realizes the integrated design of heat dissipation, waterproofing, corrosion resistance and electromagnetic shielding functions of circuit board, effectively reduces the overall thickness, improves bending resistance, and the microchannel network and gradient phase change layer work together to dissipate heat, thus increasing the heat flux density carrying capacity. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the present invention.

[0016] Figure 2 This is a structural diagram of the conductive layer.

[0017] Figure 3This is a structural diagram of the composite insulating layer.

[0018] Figure 4 This is a structural diagram of a gradient phase change thermal conductive layer.

[0019] Figure 5 This is a structural diagram of the self-healing protective layer.

[0020] The attached figures are labeled as follows: substrate layer 10, conductive layer 11, functional cover film layer 12, serpentine microchannel network 13, copper foil layer 15, upper nickel-phosphorus alloy passivation layer 14, lower nickel-phosphorus alloy passivation layer 16, adhesive layer 20, composite insulating layer 17, gradient phase change thermally conductive layer 18, self-healing protective layer 19, first sublayer 21, second sublayer 22, graphene substrate 24, hydrophobic nickel foam layer 23, PDMS substrate 26, biomimetic nano-protrusion array 25, paraffin / boron nitride phase change microcapsules 27, urea-formaldehyde microcapsules 28. Detailed Implementation

[0021] 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.

[0022] 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.

[0023] Please refer to Figure 1-5 As shown, this utility model provides a circuit board structure with a multifunctional cover film, including a substrate layer 10, a conductive layer 11 bonded and fixed to the upper surface of the substrate layer 10, and a functional cover film layer 12. The thickness ratio of the substrate layer 10, the conductive layer 11, and the functional cover film layer 12 is 1:0.2:0.8.

[0024] A serpentine microchannel network 13 is formed on the lower surface of the substrate layer 10. The channels of the serpentine microchannel network 13 are filled with a perfluoropolyether cooling liquid layer, and the openings of the serpentine microchannel network 13 are covered with a porous ceramic sealing layer. The substrate layer 10 is a polyimide composite substrate layer, within which a layer of strontium molybdate nanoparticles with a particle size of 20-50 nm is dispersed. During production, polyimide resin and strontium molybdate nanoparticles are co-extruded at a twin-screw extrusion temperature of 320°C, and then cast into an 80 μm film. The serpentine microchannels are formed by laser etching, followed by vacuum infusion of the perfluoropolyether cooling liquid.

[0025] The conductive layer 11 includes a copper foil layer 15, an upper nickel-phosphorus alloy passivation layer 14 covering the upper surface of the copper foil layer 15, and a lower nickel-phosphorus alloy passivation layer 16 covering the lower surface of the copper foil layer 15. The conductive layer 11 is fixed to the substrate layer 10 by an adhesive layer, which is configured as a zinc-aluminum hydrotalcite intercalation structure.

[0026] The functional cover film 12 includes an adhesive layer 20, a composite insulating layer 17, a gradient phase change thermal conductive layer 18, and a self-healing protective layer 19. The adhesive layer 20 is attached to the lower surface of the serpentine microchannel network 13, and the composite insulating layer 17, the gradient phase change thermal conductive layer 18, and the self-healing protective layer 19 are sequentially covered on the upper surface of the conductive layer 11 from bottom to top.

[0027] The adhesive layer 20 is configured as a halogen-free epoxy adhesive layer containing benzotriazole corrosion inhibitor, providing corrosion inhibition and flame retardant functions.

[0028] The composite insulating layer 17 comprises an alternately stacked first sublayer 21 and a second sublayer 22. The first sublayer 21 is configured as a magnetron sputtered silver nanowire mesh shielding layer, and the second sublayer 22 is configured as an electrostatically sprayed CeO2 / SiO2 corrosion-inhibiting coating. It is used for electromagnetic shielding and corrosion protection.

[0029] The gradient phase change thermally conductive layer 18 includes a graphene substrate 24 and a hydrophobic nickel foam layer 23 stacked on the graphene substrate 24. Paraffin / boron nitride phase change microcapsules 27 are embedded within the graphene substrate 24, and the in-plane thermal conductivity direction of the graphene substrate 24 is parallel to the surface of the substrate layer 10. The phase change temperature of the paraffin / boron nitride phase change microcapsules 27 is 45-60℃. The graphene substrate 24, paraffin / boron nitride phase change microcapsules 27, and hydrophobic nickel foam layer 23 are formed by hot-pressing composite. This provides heat dissipation and dynamic waterproofing.

[0030] The self-healing protective layer 19 includes a PDMS substrate 26 and a biomimetic nano-protrusion array 25 disposed on the upper surface of the PDMS substrate 26. Urea-formaldehyde microcapsules 28 are uniformly dispersed within the PDMS substrate 26. The shell of the urea-formaldehyde microcapsules 28 is made of urea-formaldehyde resin, and the core material is hydroxyl-terminated polysiloxane. During production, the urea-formaldehyde resin coats the hydroxyl-terminated polysiloxane, forming a microfluidic chip with a channel diameter of 50 μm, followed by drying and curing. A nanoimprinting process is used: PDMS prepolymer is coated to a thickness of 50 μm, then hot-pressed with a nickel template at a pressure of 10 MPa and a temperature of 120 °C, followed by UV curing at a wavelength of 365 nm and an energy of 500 mJ / cm². 2 .

[0031] In this embodiment, the functional covering film layer 12 provides excellent electromagnetic shielding, heat dissipation, and waterproofing. The adhesive layer 20 provides mechanical fixation and basic protection; the combination of the adhesive layer 20 and the serpentine microchannel network 13 achieves heat dissipation and sealing. The composite insulating layer 17, gradient phase change thermally conductive layer 18, and self-healing protective layer 19 are sequentially arranged from bottom to top over the upper surface of the conductive layer 11, providing circuit board protection and signal integrity. This embodiment provides three-dimensional protection for the circuit board while simultaneously meeting the requirements for high-density heat dissipation, dynamic waterproofing, and corrosion resistance.

[0032] 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 structure with a multifunctional cover film, comprising a substrate layer (10), a conductive layer (11) bonded and fixed to the upper surface of the substrate layer (10), and a functional cover film layer (12), characterized in that: The lower surface of the substrate layer (10) is provided with a serpentine microchannel network (13), and the channels of the serpentine microchannel network (13) are filled with a perfluoropolyether cooling liquid layer. The openings of the serpentine microchannel network (13) are covered with a porous ceramic sealing layer. The functional cover film layer (12) includes an adhesive layer (20), a composite insulating layer (17), a gradient phase change thermal conductive layer (18), and a self-healing protective layer (19). The adhesive layer (20) is attached to the lower surface of the serpentine microchannel network (13), and the composite insulating layer (17), the gradient phase change thermal conductive layer (18), and the self-healing protective layer (19) are sequentially covered on the upper surface of the conductive layer (11) from bottom to top.

2. The circuit board structure with a multi-functional cover film according to claim 1, characterized by: The conductive layer (11) includes a copper foil layer (15) and an upper nickel-phosphorus alloy passivation layer (14) covering the upper surface of the copper foil layer (15) and a lower nickel-phosphorus alloy passivation layer (16) covering the lower surface of the copper foil layer (15).

3. The circuit board structure with a multifunctional cover film according to claim 1, characterized in that: The adhesive layer (20) is configured as a halogen-free epoxy adhesive layer containing benzotriazole corrosion inhibitor.

4. The circuit board structure with multi-functional coverlay film according to claim 1, characterized in that: The composite insulating layer (17) includes an alternately stacked first sublayer (21) and second sublayer (22), wherein the first sublayer (21) is configured as a silver nanowire mesh shielding layer and the second sublayer (22) is configured as a CeO2 / SiO2 corrosion inhibitor coating.

5. The circuit board structure with multi-functional coverlay film according to claim 1, characterized in that: The gradient phase change thermal conductive layer (18) includes a graphene substrate (24) and a hydrophobic nickel foam layer (23) stacked on the graphene substrate (24). Paraffin / boron nitride phase change microcapsules (27) are embedded inside the graphene substrate (24). The in-plane thermal conductivity direction of the graphene substrate (24) is parallel to the surface of the substrate layer (10).

6. The circuit board structure with a multifunctional cover film according to claim 1, characterized in that: The self-healing protective layer (19) includes a PDMS substrate (26) and a biomimetic nano-protrusion array (25) disposed on the upper surface of the PDMS substrate (26). Urea-formaldehyde microcapsules (28) are uniformly dispersed in the PDMS substrate (26). The shell of the urea-formaldehyde microcapsules (28) is made of urea-formaldehyde resin, and the core material is made of hydroxyl-terminated polysiloxane.

7. The circuit board structure with a multifunctional cover film according to claim 1, characterized in that: The conductive layer (11) is fixed to the substrate layer (10) by an adhesive layer, which is configured as a zinc-aluminum hydrotalcite intercalation structure.

8. The circuit board structure with a multifunctional cover film according to claim 1, characterized in that: The substrate layer (10) is configured as a polyimide composite substrate layer, wherein a layer of strontium molybdate nanoparticles with a particle size of 20-50 nm is dispersed in the polyimide composite substrate layer.

9. A circuit board structure with a multifunctional cover film according to claim 5, characterized in that: The phase transition temperature of the paraffin / boron nitride phase change microcapsules (27) is 45-60°C.

10. The circuit board structure with a multifunctional coverlay film according to any one of claims 1-9, characterized in that: The thickness ratio of the substrate layer (10), the conductive layer (11), and the functional cover film layer (12) is 1:0.2:0.8.

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