Electromagnetic shield function electronic circuit board

Abstract

The utility model relates to the technical field of adhesive, new material and printed circuit board manufacturing technology, especially relates to electromagnetic shielding function type electronic circuit board and manufacturing method. A kind of electromagnetic shielding function type electronic circuit board, comprising: a core plate with inner layer circuit;A functional composite layer is covered on at least one surface of the core plate, the functional composite layer includes a dielectric layer and a metal material layer with a thickness of 0.1 nanometer to 5 microns;Wherein, the metal material layer is patterned, and is reserved in preset shielding area to form electromagnetic shielding layer;In non-shielding area is removed, so that the dielectric layer exposed in this area forms insulating protective layer.The scheme, can prepare the flexible composite material of thinner metal layer, more simplified process, more diversified function.

Description

Technical Field

[0001] This utility model relates to the fields of adhesives, new materials and printed circuit board manufacturing technology, and in particular to electromagnetic shielding functional electronic circuit boards. Background Technology

[0002] As electronic products evolve towards thinner, lighter, higher-performance, and more integrated designs, traditional flexible copper-clad laminate (FRCC) materials and processes face numerous challenges. First, the relatively thick copper foil limits the material's thinness, particularly in the manufacture of intricate circuitry, often resulting in severe etch side etching and low yield. Second, existing manufacturing processes are cumbersome, typically requiring multiple alignment, lamination, and die-cutting steps, leading to high costs and difficulty in controlling errors. Furthermore, the properties of existing materials are relatively fixed, making it difficult to flexibly adjust them to meet the needs of different application scenarios, especially in specific electromagnetic shielding and battery current collector applications, where the material's functional customization is poor. Utility Model Content

[0003] An electromagnetic shielding functional electronic circuit board, comprising: A core board with inner layer circuitry; A functional composite layer covering at least one surface of the core board, the functional composite layer comprising a dielectric layer with a thickness of 1 to 25 micrometers and a metallic material layer with a thickness of 0.1 nanometers to 5 micrometers; The metal material layer is patterned and retained in a predetermined shielding area to form an electromagnetic shielding layer; it is removed in the unshielded area, exposing the dielectric layer in that area to form an insulating protective layer.

[0004] A method for manufacturing an electromagnetically shielded functional electronic circuit board as described above includes the following steps: Prepare an ultrathin flexible composite material consisting of a dielectric layer, a semi-cured adhesive layer, and a metal material layer with a thickness of 0.1 nanometers to 5 micrometers; The composite material is hot-pressed to a core board with inner circuitry via its semi-cured adhesive layer. The metal material layer is patterned by photolithography etching process to retain the metal material layer in the preset shielding area to form an electromagnetic shielding layer, and the metal material layer is removed in the non-shielding area.

[0005] The first aspect of this invention provides a method for preparing an ultrathin metal layer flexible composite material. The core of this method lies in forming an ultrathin metal layer at the nanometer to micrometer scale using high-precision deposition technology, and combining this with a liquid resin coating process to form a functional polymer layer, thereby achieving precise control over the material's structure and properties. The method includes the following steps: The substrate pretreatment step provides a substrate layer; The metal layer deposition step involves depositing a metal material layer with a thickness of 0.1 nanometers to 5 micrometers on at least one surface of the substrate layer by vacuum sputtering or electroplating. The adhesive coating step involves coating a liquid resin composition onto the surface of a substrate layer or a metal material layer, and then forming a functional polymer layer through a baking process.

[0006] Secondly, an ultrathin metal layer flexible composite material prepared by the above method is provided. This material, characterized by its ultrathin conductive layer and customizable functional polymer layer, can meet the stringent requirements of next-generation electronic products.

[0007] Thirdly, it provides innovative applications of this composite material in multiple fields. Using this material, the manufacturing process of multilayer circuit boards, EMI shielding structures, and composite current collectors can be greatly simplified, costs reduced, and product performance improved.

[0008] Regarding the substrate layer: In one embodiment of this invention (i.e., the "direct method"), the substrate layer is a polymer film. This film serves not only as the dielectric layer of the final product but also as a support during the production process. Optional materials include, but are not limited to: polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), high-temperature resistant PET, release polyethylene naphthalate (PEN), polyphenylene ether (PPO), cyclic olefin copolymer (COP), polyphenylene sulfide (PPS), etc. The film thickness can be selected according to application requirements, typically between 5 micrometers and 50 micrometers. To enhance the adhesion of subsequent metal layers, plasma treatment or corona treatment of the film surface is a preferred technique of this invention.

[0009] In another embodiment of this invention (i.e., the "transfer method"), the substrate layer is a carrier release film. Its main function is to provide stable mechanical support during production and to be peeled off after the process is complete. This carrier release film is preferably a PET or PEN film with good dimensional stability and heat resistance, and its thickness is preferably not less than 10 micrometers, for example, 25 micrometers, 50 micrometers, or 75 micrometers, to ensure flatness and tension control in roll-to-roll processes. Its surface has release properties to ensure that it can ultimately be cleanly separated from the metal layer or functional polymer layer.

[0010] Regarding the metal material layer: One of the core features of this invention lies in the ultra-thin metal material layer, with a thickness ranging from 0.1 nanometers to 5 micrometers. This broad range covers a variety of application scenarios: For applications where the layer is only needed as a seed layer for subsequent electroplating, the thickness is preferably 10 nanometers to 200 nanometers.

[0011] For applications requiring direct formation of conductive lines or EMI shielding layers, the thickness is preferably 0.5 micrometers to 5 micrometers.

[0012] For some specialized semiconductor or optical applications, the thickness may be less than 10 nanometers.

[0013] The metallic material layer can be selected from a variety of conductive materials, including but not limited to: copper (Cu), nickel (Ni), chromium (Cr), zinc (Zn), tin (Sn), indium (In), nano-silver, indium tin oxide (ITO), and alloy materials such as titanium copper (Ti-Cu). Among them, titanium copper alloy is a preferred option, typically by first depositing a 5-30 nm layer of titanium (Ti) or chromium (Cr) as an adhesive bonding layer, and then depositing a copper layer.

[0014] When preparing copper layers using electrolytic plating, a multi-stage current density control strategy can be employed to obtain a uniform and dense thin layer. For example: the first step uses a low current density of 5-20 A / dm² for nucleation, lasting 1-4 seconds; the second step uses a medium current density of 20-50 A / dm² for rapid thickening, also lasting 1-4 seconds; and the third step uses a high current density of 50-100 A / dm² to complete the plating. The electrolyte formulation may include: 50-100 g / L copper ions, 100-250 g / L sulfuric acid, and appropriate amounts of leveling agents (such as SPS), brighteners (such as gelatin), and chloride ions (10-50 ppm). The electrolyte temperature is preferably controlled at 40-60℃.

[0015] When using vacuum sputtering, to ensure coating quality and adhesion, the preferred process parameters are as follows: evacuate the coating chamber to a base vacuum of 1-2 × 10⁻³ Pa; introduce argon gas to 2-5 Pa and apply a bias voltage of 600-900 V to perform glow discharge cleaning on the substrate for 1-20 minutes; then perform coating under the following conditions: working gas pressure 3-7 × 10⁻¹ Pa, substrate bias voltage 100-400 V, bias voltage duty cycle 10-30%, and sputtering duty cycle 10-60%.

[0016] Regarding the liquid resin composition and functional polymer layer: This invention employs a liquid coating process to form the functional polymer layer, which offers significant flexibility. The main resin of the liquid resin composition can be selected from: General-purpose resins: acrylic resin, epoxy resin.

[0017] High-performance resins: Ajinomoto stacking film (ABF) resin and bismaleimide-triazine (BT) resin for IC substrates.

[0018] High-temperature / high-frequency resistant resins: polyimide (PI) resin, polyamide-imide (PAI) resin, fluorinated polymers (such as liquid dispersions of FPA and PTFE), liquid precursors of liquid crystal polymers (LCP), polyphenylene sulfide (PPS) resin, etc.

[0019] The functional polymer layer can be a semi-cured (B-stage) adhesive layer for subsequent hot-pressing lamination, or a fully cured (C-stage) medium layer as part of the final product structure.

[0020] The baking process is crucial for forming the functional polymer layer. Multi-stage tunnel ovens are typically used to achieve precise control over the curing process. For example, a four-stage oven temperature profile might be configured as follows: a first heating zone (60-100℃) for solvent evaporation; a second heating zone (100-150℃) for resin pre-reaction; a third heating zone (150-250℃, up to 500℃ depending on the resin system) for primary or semi-curing reactions; and a fourth cooling / holding zone (60-150℃) for stabilizing the structure. The conveyor speed is typically between 1-30 m / min, matched to the oven length and temperature profile.

[0021] Regarding functional additives: Functional additives may be added to liquid resin compositions to meet specific application requirements.

[0022] Anti-ion migration: For applications such as power batteries, to prevent short circuits caused by copper ion migration, a mixture of acylhydrazine compounds and sulfur-containing phenyl phosphite organic compounds can be added. The preferred mass ratio of the two is 1:(0.5-5).

[0023] Improve thermal conductivity: To enhance the heat dissipation capacity of the material, highly thermally conductive electrically insulating fillers, such as aluminum nitride (AlN), alumina (Al2O3), boron nitride (BN), and other micron or nano-sized powders, can be added.

[0024] Other additives may include flame retardants, leveling agents, defoamers, coupling agents, etc., to improve processability or final product performance.

[0025] An ultrathin metal layer flexible composite material, the structure of which includes: A layer of metallic material with a thickness of 0.1 nanometers to 5 micrometers; A functional polymer layer combined with the metal material layer, the functional polymer layer being formed by a coating and baking process from a liquid resin composition comprising at least one resin.

[0026] Furthermore, it also includes a polymer film as a medium layer, the metal material layer is deposited on one surface of the polymer film, and the functional polymer layer is formed on the other surface of the polymer film.

[0027] Furthermore, the functional polymer layer is an adhesive layer in a semi-cured state.

[0028] Furthermore, the structure is a sandwich structure of "metal material layer - functional polymer layer - metal material layer", wherein the functional polymer layer is a cured medium layer.

[0029] Furthermore, it also includes a carrier release film, on which the metal material layer is deposited and the functional polymer layer is formed on the surface of the metal material layer.

[0030] Furthermore, the functional polymer layer is an adhesive layer in a semi-cured state or a cured medium layer.

[0031] Furthermore, the metal material layer is selected from at least one of copper, nickel, chromium, zinc, tin, indium, titanium-copper alloy, indium tin oxide (ITO), or nano silver.

[0032] Furthermore, at least one resin in the liquid resin composition is selected from epoxy resin, acrylic resin, polyimide resin, modified polyimide resin, Ajinomoto stacked film (ABF) resin, bismaleimide-triazine (BT) resin, liquid crystal polymer (LCP) resin, or polytetrafluoroethylene (PTFE) resin.

[0033] Furthermore, the functional polymer layer also includes functional additives.

[0034] Furthermore, the functional additives are selected from: Acylhydrazine compounds and / or sulfur-containing phenyl phosphite organic compounds used to inhibit the migration of metal ions; or aluminum nitride, aluminum oxide, or boron nitride powders used to improve thermal conductivity.

[0035] The beneficial effects of this utility model are: The core of this technical solution lies in the use of an integrated functional composite layer to cover the circuit board. By patterning the ultra-thin metal material on the surface of this composite layer, a "dual-purpose material" is cleverly achieved: in areas requiring shielding, the retained metal portion directly constitutes a highly efficient electromagnetic shielding layer; while in other areas, the dielectric layer exposed after removing the metal naturally serves as an insulating protective layer. This design completely replaces the traditional double-layer structure of "cover film + shielding film," integrating two functions into a single composite layer. This not only significantly reduces the total thickness of the circuit board and greatly improves its flexibility, but also fundamentally simplifies the originally complex multi-step lamination and alignment process into a one-time pressing and patterning process, greatly shortening the production cycle and reducing material and manufacturing costs.

[0036] Because the insulation protection function of this solution is provided by the dielectric layer of the functional composite layer itself, the windows that need to expose the pads are formed through subsequent precision processing (such as laser windowing), rather than traditional cover film bonding. This completely avoids the phenomenon of adhesive overflow caused by lamination bonding from a physical structure perspective. The edges of the pad windows are clean and neat, ensuring the yield and long-term reliability of subsequent component soldering (SMT), solving a major quality problem that has plagued the industry.

[0037] The ultra-thin metal layer on the surface of this circuit board can not only be patterned as an electromagnetic shielding layer, but its excellent electrical and thermal conductivity also allows engineers to flexibly design heat dissipation paths, grounding lines, or other RF functional patterns in specific areas on the same layer. This ability to achieve multifunctional integration on a single layer provides unprecedented freedom for the innovative design of complex, high-performance electronic products, resulting in more compact product structures and superior electrical and thermal performance.

[0038] The functional composite layer in this solution can be effectively integrated with various core boards, including flexible circuit boards, rigid circuit boards, and rigid-flex circuit boards. Simultaneously, its metal and dielectric layers can be made from a variety of high-performance materials such as copper, titanium copper, PI, and LCP to meet the stringent requirements for electromagnetic compatibility, temperature resistance, and high-frequency performance in diverse fields ranging from consumer electronics to automotive, medical, and aerospace, demonstrating strong versatility and application potential. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of a structural layer of the ultrathin metal layer flexible composite material layer of this utility model.

[0040] Figure 2 This is a schematic diagram of another structural layer of the ultrathin metal layer flexible composite material layer of this utility model.

[0041] Figure 3This is a schematic diagram of an electromagnetic shielding functional electronic circuit board according to the present invention. Detailed Implementation

[0042] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0043] This utility model provides a method for preparing an ultrathin metal layer flexible composite material, comprising the following steps: Substrate pretreatment step: Provide a substrate layer; Metal layer deposition step: A metal material layer with a thickness of 0.1 nanometers to 5 micrometers is deposited on at least one surface of the substrate layer by vacuum sputtering or electrolytic plating. Adhesive coating step: A liquid resin composition is coated on the surface of the substrate layer or the metal material layer, and a functional polymer layer is formed by a baking process.

[0044] Baking step: The functional polymer layers of two semi-finished products obtained through the substrate pretreatment step to the bonding coating step are bonded together and hot-pressed to form a sandwich structure composite. Peeling step: Peel the carrier release film from both sides of the sandwich structure composite to obtain a composite material with a structure of "metal material layer - functional polymer layer - metal material layer".

[0045] An ultrathin metal layer flexible composite material is prepared by the aforementioned method for preparing ultrathin metal layer flexible composite materials.

[0046] An ultrathin metal layer flexible composite material, the structure of which includes: A layer of metallic material with a thickness of 0.1 nanometers to 5 micrometers; A functional polymer layer combined with the metal material layer, the functional polymer layer being formed by coating and baking a liquid resin composition comprising at least one of epoxy resin, acrylic resin, polyimide resin, BT resin or ABF resin.

[0047] The functional polymer layer is in a semi-cured state and is used as an adhesive layer, i.e., a semi-cured adhesive layer.

[0048] Furthermore, the ultrathin metal layer flexible composite material structure is a sandwich structure of "metal material layer - functional polymer layer - metal material layer", wherein the functional polymer layer is a cured dielectric layer.

[0049] In detail, this ultrathin metal layer flexible composite material comprises two structures, as follows: Structure 1: such as Figure 1As shown, the ultrathin metal layer flexible composite material consists of, from bottom to top, a metal material layer release film (i.e., a metal material layer protective film), a metal material layer, a dielectric layer, a semi-cured adhesive layer, and a semi-cured adhesive layer release film protective layer (i.e., a semi-cured adhesive layer protective film). Structure 1 contains an independent "dielectric layer," the core of which is that it includes a pre-existing, independent "dielectric layer." This dielectric layer is typically a polymer film with specific thickness and properties, such as a 12.5 μm PI film. The corresponding preparation process is process path A (direct method / film pre-coating followed by deposition). Structure 1 is manufactured as follows: 1. Take a PI film (this is the "dielectric layer"); 2. Deposit a "metal material layer" onto one side of the PI film; 3. To protect this metal layer, apply a "metal material layer protective film" to it; 4. Coat a "semi-cured adhesive layer" onto the other side of the PI film; 5. To protect the adhesive, apply a "semi-cured adhesive layer protective film." Structure 2 is primarily used for layer-addition manufacturing of multilayer circuit boards and integrated EMI shielding. In use, the adhesive protective film is removed, and the semi-cured adhesive layer is hot-pressed onto another circuit board. The metal material layer release film is a PET release film, a high-temperature release film, or a release protective film, used to protect the surface of the metal material layer from damage, or as a carrier for making ultra-thin copper foil materials, or as an insulating material for current-collecting composite materials. The metal material layer is deposited onto the dielectric layer using sputtering / electroplating equipment, with a thickness of 0.1 nanometers / micrometers to 5 micrometers. The dielectric layer is a thin film layer that has undergone corona treatment or plasma pretreatment, including but not limited to any one of the following: PI film, MPI film, LCP film, PTFE film, PET film, high-temperature resistant PET film, release PEN film, PPO film, COP film, and PPS film. The semi-cured adhesive layer includes but is not limited to... A high-temperature resistant adhesive layer, acrylic resin and epoxy resin materials, an anti-particle migration adhesive layer, an ABF adhesive layer, a BT adhesive layer, and an adhesive layer suitable for high-frequency resin materials and semiconductor materials are applied using a coating device to coat the above-mentioned liquid adhesive and then baked on a tunnel oven to form a semi-cured adhesive layer on the dielectric layer and conductive layer. The release film protective layer of the semi-cured adhesive layer is a PET release film or release paper, which is laminated onto the semi-cured adhesive layer using a composite pressing device to protect the adhesive layer, ensure the cleanliness of the semi-cured adhesive layer, and maintain the stability of the semi-cured adhesive layer. When the FRCC material is laminated onto the multilayer circuit board, the release film protective layer of the semi-cured adhesive layer is first peeled off.

[0050] Structure 2: such as Figure 2As shown, the ultrathin metal layer flexible composite material consists of, from bottom to top, a thick PET carrier release film layer, a copper metal layer, a semi-cured adhesive layer, and a semi-cured adhesive layer protective film layer. Compared to structure one, structure two lacks an independent "dielectric layer," instead using a "carrier." The most significant feature of this structure is the absence of an independent, pre-fabricated "dielectric layer." Instead, it uses a "thick PET carrier release film layer." This carrier film is not part of the final product; it is merely a production tool that will be peeled off during final use. The corresponding manufacturing process is process path B (transfer method / plating followed by coating). This structure is manufactured as follows: 1. Take a thick PET carrier release film; 2. Plate a "copper metal layer" onto the release surface of the carrier film; 3. Directly coat the "semi-cured adhesive layer" onto the metal layer; 4. To protect the adhesive, apply a "semi-cured adhesive layer protective film layer."

[0051] Structure 2 is a semi-finished product or transfer material. Its applications are as follows: 1. For IC carrier boards (RCC): Its semi-cured adhesive layer is aligned and pressed with the core board of the IC carrier board. After curing, the "thick PET carrier release film layer" is peeled off, thereby transferring the "metallic copper layer" and the cured "adhesive layer" together to the core board. Here, the cured adhesive layer acts as the dielectric layer. 2. For manufacturing composite current collectors: Two parts of this structure are taken, their adhesive layers are pressed together, and then the "thick PET carrier release film layer" is peeled off from both sides, forming a "metal-polymer-metal" sandwich structure. The metal material layer can be any one of conductive metals with a conductor layer, such as copper, nickel, cadmium, chromium, zinc, titanium copper, ITO, tin, indium, or nano-silver.

[0052] Application of a preparation method for a flexible composite material based on the aforementioned ultrathin metal layer in the manufacture of electronic circuit boards or composite current collectors.

[0053] A method for fabricating an electromagnetically shielded functional electronic circuit board includes the following steps: Provide an inner core board and the aforementioned ultrathin metal layer flexible composite material; The semi-cured functional polymer layer of the composite material is aligned with the inner core board and then hot-pressed together. On the metal material layer of the composite material, an outer layer circuit or functional pattern is fabricated using a patterning process.

[0054] An electromagnetic shielding functional electronic circuit board is prepared by the above-mentioned method for preparing an electromagnetic shielding functional electronic circuit board.

[0055] An electromagnetic shielding functional electronic circuit board, such as Figure 3As shown, from bottom to top, the circuit board includes a double-sided flexible (or sleek) copper-clad laminate layer (D / SFCCL); an ultra-thin metal flexible composite material layer (FRCC); and a liquid photosensitive solder resist ink layer (LPI). Specifically: D / SFCCL layer: This is a double-sided flexible copper-clad laminate that has been processed, with inner layer circuitry on both sides. It forms the foundation and framework of the entire circuit board. FRCC layer: This is the ultra-thin metal flexible composite material layer of this design, laminated onto the outer surface of the aforementioned D / SFCCL core layer. Its semi-cured adhesive layer fills and bonds the inner layer circuitry, while the ultra-thin metal layer on its surface is used to create the outermost fine circuitry or EMI shielding layer. LPI layer: After all circuitry (including the outer layer circuitry on the FRCC layer) has been fabricated, it is coated onto the outermost surface to protect the circuitry and precisely define the soldering areas. It should be noted that in EMI shielding applications, the dielectric layer of the FRCC can replace the function of the LPI layer; therefore, in the final product, the LPI layer may only exist locally or even be completely replaced.

[0056] Example 1: Preparation of ultrathin FRCC materials by the "direct method" This embodiment demonstrates a method for directly preparing ultrathin FRCCs based on polymer thin films. Specifically, it includes the following steps: Substrate pretreatment: A roll of 12.5 μm thick polyimide (PI) film is used as the substrate layer. The PI film roll is fed into a roll-to-roll vacuum apparatus. First, one surface is treated with argon plasma glow discharge for 1-5 minutes. This step aims to clean the surface and increase its surface energy and micro-roughness to improve the adhesion of subsequent metal layers.

[0057] Metal layer deposition: A titanium-copper (Ti-Cu) alloy layer is deposited as the metal material layer on the pretreated PI film surface using DC magnetron sputtering. First, a titanium (Ti) layer with a preferred thickness of 10 nm is sputtered as a bonding layer, and then a copper (Cu) layer with a preferred thickness of 100 nm is sputtered as a conductive layer. The total thickness of the metal material layer is controlled at 110 nm.

[0058] Adhesive Coating and Semi-Cure: The PI film with the deposited metal layer is fed into a cleanroom coating room. On its other side (the unmetal-coated side), a layer of liquid epoxy resin composition (as an adhesive) is uniformly coated using a slot-die. This composition may contain accelerators and fillers, and the coating thickness is controlled at 15 ± 2 micrometers.

[0059] Baking: The coated film is fed into a four-section tunnel oven. The temperatures of each section are set as follows: Zone 1 80°C, Zone 2 120°C, Zone 3 160°C, and Zone 4 100°C. The film passes through the oven at a speed of 5 m / min, causing the liquid resin composition to react and form a viscous, semi-cured (B-stage) functional polymer layer (i.e., adhesive layer). Those skilled in the art will understand that this temperature profile and speed can be optimized based on the DSC (Differential Scanning Calorimetry) analysis results of the resin system used.

[0060] Protection and winding: A 50μm thick PET release film is laminated onto the surface of the semi-cured adhesive layer for protection. Finally, the material is wound up to obtain the finished ultra-thin FRCC material, which can be used for subsequent circuit board lamination.

[0061] In Example 1, the PI film surface is subjected to plasma treatment before depositing the metal layer. In traditional processes, metal is directly sputtered or electroplated onto smooth polymer films such as PI, resulting in very poor adhesion and easy peeling of the metal layer during subsequent processing. This example, through plasma treatment, introduces a microscopic rough structure and highly active chemical functional groups onto the PI surface, significantly enhancing the physical anchoring and chemical bonding between metal atoms and the PI surface. This results in a significant increase in peel strength, ensuring the reliability of the ultrathin metal layer in subsequent demanding processes such as bending and hot pressing. This is a crucial step in realizing the industrialization of this technology.

[0062] Example 2: Preparation by "transfer method" and its application in composite current collectors This embodiment demonstrates a transfer process using a carrier membrane, which is ultimately applied to the manufacture of composite current collectors.

[0063] Preparation of semi-finished products: The substrate pretreatment step provides a 25μm thick PET release film as the carrier release film. In the metal deposition step, a 1μm thick copper foil is electroplated onto its release surface using a roll-to-roll electroplating process. Electroplating employs a three-stage current density control, with the electrolyte containing 80g / L copper ions and 40ppm SPS additive. In the adhesive coating step, a liquid PI resin composition containing an anti-copper ion migration additive (a 1:1 mixture of an acylhydrazine compound and a sulfur-containing phosphite) is coated onto the 1μm copper foil surface. In the baking step, it is placed in a tunnel oven for high-temperature baking (up to 350°C) to fully imidize the liquid PI, forming a 5μm thick cured PI dielectric layer (functional polymer layer). In the peeling step, the substrate pretreatment step is repeated to the baking step to prepare two identical rolls of the "PET carrier-copper foil-PI dielectric layer" semi-finished product.

[0064] Composite and Transfer: In the substrate pretreatment step, the PI dielectric layers of the two rolls of semi-finished products are aligned face-to-face using a CCD vision alignment device. In the metal deposition step, the aligned material is fed into a double-strand hot press and hot-pressed at 200°C and 200psi to ensure a tight bond between the two PI dielectric layers. The double-strand press allows for continuous production and is more efficient than traditional flatbed presses. In the adhesive coating step, the PET carrier release film is continuously peeled off from both sides of the hot-pressed composite material using peeling rollers and then wound up for recycling. The baking step finally yields a composite copper foil current collector with a structure of "1μm copper foil - 10μm PI dielectric layer - 1μm copper foil," which is then wound up. This current collector exhibits excellent safety and mechanical strength.

[0065] In Example 2, a thick PET release film is used as a temporary carrier, which is then peeled off after all processes are completed. The core idea of ​​this "transfer method" cleverly avoids the significant technical difficulties of directly performing roll-to-roll processing on ultra-thin (e.g., 3-5 μm) functional films. The thick PET carrier provides excellent mechanical strength and dimensional stability, allowing processes such as sputtering, electroplating, coating, and baking to be carried out stably under flat, defect-free conditions. This fundamentally improves the production yield and process window of advanced materials such as composite current collectors, and reduces the extreme requirements for equipment precision. Anti-copper ion migration additives are added to the liquid PI resin. This is an advantage not found in traditional composite current collectors that use pre-fabricated PP or PET films as the dielectric layer. By directly constructing a chemical defense line in the polymer layer, potentially migrating copper ions can be effectively captured and passivated, greatly improving the safety of power batteries under high-temperature and high-voltage conditions, preventing thermal runaway caused by internal short circuits, and meeting the stringent safety standards for high-end applications such as new energy vehicles.

[0066] Example 3: Application in an integrated EMI shielding circuit board This embodiment demonstrates how to simplify the manufacturing of EMI shielding circuit boards using the ultrathin FRCC material prepared in Example 1.

[0067] Lamination: Take a flexible printed circuit board (FPC) core board with its internal circuitry already fabricated. Peel off the adhesive release film of the ultra-thin FRCC material and align its semi-cured adhesive layer with the outer layer of the FPC core board. Hot press the laminator at 180°C and 400psi for 30 minutes to cure and bond the FRCC and core board together.

[0068] Patterning: A standard photolithography etching process is used on the surface of the ultrathin metal layer of FRCC. The substrate pretreatment step involves coating photoresist and exposing it through a mask whose pattern is designed to remain only in the areas requiring shielding. After development in the metal layer deposition step, the metal layer in the areas not requiring shielding is exposed. The adhesive coating step uses an etchant to remove the exposed metal layer. A baking step removes any remaining photoresist.

[0069] Finished product: At this point, the remaining metal layer forms the designed EMI shielding mesh or shielding block. The PI dielectric layer exposed after the metal is etched away naturally becomes an insulating cover film protecting the underlying circuitry. The entire process eliminates the need for traditional cover films and shielding films, achieving both circuit protection and electromagnetic shielding in one step.

[0070] In Example 3, using the same FRCC material, a selective etching process is employed to allow the retained metal layer to act as an EMI shielding layer, while the exposed PI dielectric layer acts as an insulating cover film. This is a disruptive innovation to the traditional FPC manufacturing process. It completely replaces the cumbersome, costly, and error-prone process of "cover film punching → cover film alignment and bonding → shielding film die-cutting → shielding film alignment and bonding" with a simple, patterned process. The benefits are multi-dimensional: the total product thickness is reduced by one film (shielding film) and one adhesive layer, resulting in a thinner and more flexible product. It fundamentally eliminates the problem of adhesive overflow at the cover film window and the surface unevenness caused by multi-layer film stacking, facilitating precise placement of subsequent SMT components. It significantly reduces the material costs of the cover film and shielding film, as well as related mold, equipment, and labor costs. Engineers can freely design shielding areas, heat-conducting areas, grounding lines, etc., on the same metal layer, achieving unprecedented functional integration.

[0071] The ultrathin metal layer flexible composite material, its preparation method, and its application provided by this invention have the following advantages compared to the prior art: Breakthrough capabilities in thinning and refining: By controlling the thickness of the conductive metal layer to the nanometer to micrometer level (0.1nm-5μm), the ultimate thinness and high flexibility of electronic products are fundamentally achieved. At the same time, the ultra-thin initial metal layer is a key prerequisite for manufacturing ultra-fine circuits with linewidth / spacing below 20 micrometers using additive or semi-additive (SAP) methods, overcoming the bottleneck caused by the etching factor of traditional subtractive methods.

[0072] Revolutionary process simplification and cost reduction: In applications such as multilayer circuit boards, electromagnetic shielding (EMI), and thermal conductivity, the integrated material solution of this invention can replace two or more traditional materials (such as copper foil + PP sheet, or cover film + shielding film), combining multiple separate processes (such as alignment, lamination, and die-cutting) into one step, greatly simplifying the production process, shortening the manufacturing cycle, and reducing the consumption of equipment, manpower, and materials, thereby significantly reducing the overall cost.

[0073] High degree of functional integration and design freedom: The liquid coating process forms a functional polymer layer, allowing for flexible customization of material properties. For example, by adding specific fillers to the resin, the material can be endowed with properties such as resistance to ion migration, high thermal conductivity, and low loss at high frequencies. At the application level, multiple functions such as conductive lines, shielding, thermal conductivity, and grounding can be simultaneously achieved on the same metal layer through graphical design, providing unprecedented freedom for product innovation design.

[0074] Exceptional manufacturing feasibility and product quality: The innovative "transfer method" process utilizes a stable, thick carrier film to solve the industry pain points of wrinkling and breakage in roll-to-roll production of ultra-thin functional films, significantly improving production yield and stability. Furthermore, the application solutions of this invention (such as EMI integration) avoid quality defects such as adhesive overflow and uneven multilayer film stacking in traditional processes, enhancing the reliability and appearance consistency of the final product.

[0075] In detail: A method for preparing an ultrathin metal layer flexible composite material includes the following production process steps: S1. Unwind the dielectric layer material and use plasma or corona equipment to treat the side of the dielectric layer that needs to be electroplated / sputtered with a metal layer, making the surface of the dielectric layer rough and increasing the adhesion and uniformity of the metal material layer. S2. Metal material is deposited onto the rough surface of the dielectric layer using sputtering / electroplating equipment, and the thickness of the metal material layer is 0.1 nanometers / micrometers to 5 micrometers; S3. A PET release film or high-temperature protective film or protective film layer is laminated onto the metal material layer using a composite pressing equipment to protect the metal material layer. S4. In a cleanroom, use coating equipment to apply liquid adhesive to the medium layer or the metal material layer. S5. The materials obtained from S1 to S4 are transferred to a tunnel oven. The tunnel oven includes 1-9 heating and baking zones, each 1-9 meters long, with a temperature not exceeding 500℃. The materials are then transferred to several heating and baking zones in the tunnel oven at a speed of 1-30 m / min for segmented baking. The adhesive applied in S4 is then transferred to the medium layer to form a semi-cured adhesive layer. S6. Using a composite pressing device, a protective film layer for the adhesive is laminated onto the semi-cured adhesive layer. The protective film layer is a PET release film layer or a release paper layer, used to protect the semi-cured adhesive and keep the semi-cured adhesive layer clean and stable.

[0076] Another method for preparing ultrathin metal layer flexible composite materials, using composite copper foil current collector materials, includes the following steps: S1. Unwind the metal material layer release film layer; the metal material layer release film layer is a PET release film or a high-temperature resistant release film with a thickness of not less than 10μm, and the PET release film or the high-temperature resistant release film is a carrier film for the metal material layer; S2. Electroplating / sputtering a metal material layer, wherein a metal material layer is electroplated / sputtered on the release surface of the PET carrier film, and the thickness of the metal material layer is 0.1 nanometers / micrometers to 5 micrometers; S3. Coating a dielectric layer: A dielectric layer is uniformly coated on the metal material layer obtained in S2. The dielectric layer is a liquid adhesive with a thickness of 3-100 micrometers. S4. Semi-curing treatment of the dielectric layer: The material obtained in S3 is transferred to a tunnel oven. The tunnel oven includes 1-9 heating and baking zones, each 1-9 meters long, with a temperature not exceeding 500℃. The material passes through several heating and baking zones in the tunnel oven at a speed of 1-30 m / min for segmented baking. The adhesive applied in S3 forms a semi-cured dielectric layer on the copper foil. S5. Composite release film: A composite release film protective layer is obtained from the semi-cured medium layer of the material in S4 using a lamination equipment. This layer is used to protect the semi-cured medium layer, keeping it clean and maintaining stable performance. S6. The ultra-thin FRCC material obtained through S1-S5 is wound up.

[0077] There are two application methods for ultrathin metal layer flexible composite materials: The first application method is shown in the following steps: S1. Peel off the release film protective layer of the semi-cured dielectric layer. Prepare two rolls of the FRCC material. Unwind the first roll of FRCC material through the conveyor roller, placing the semi-cured dielectric layer release film protective layer of the FRCC material at the bottom layer. Peel off the semi-cured dielectric layer release film protective layer through the guide roller, and simultaneously wind up the semi-cured dielectric layer release film using the take-up roller. Unwind the second roll of FRCC material through the conveyor roller, placing the semi-cured dielectric layer release film protective layer of the FRCC material at the top layer. Peel off the semi-cured dielectric layer release film protective layer through the guide roller, and simultaneously wind up the semi-cured dielectric layer release film using the take-up roller. S2. Align FRCC materials: Use an alignment device to align the first and second FRCC material rolls obtained in S1 so that the first semi-cured medium layer and the second semi-cured medium layer can cover and align with each other. S3. High-temperature pressing and curing of semi-cured media layers: Using a pressing device, the first and second semi-cured media layers aligned in step S2 are hot-pressed at a temperature of 30℃-500℃ and a pressure of 10-800psi for 1-60 minutes. After hot pressing, the first and second semi-cured media layers are completely cured and bonded together. S4. Peel off the PET carrier film. Use guide rollers to peel off the first PET carrier film and the second PET carrier film, and at the same time use take-up rollers to take up the first PET carrier film and the second PET carrier film.

[0078] S5. Obtain the composite copper foil current collector material. The material structure obtained after steps S1-S4 is a sandwich structure of metal material layer-dielectric layer-metal material layer.

[0079] Preferably, the dielectric layer includes, but is not limited to, any one of the following films: PI film, MPI film, LCP film, PTFE film, PET release film, high-temperature resistant PET release film, PEN film, PPO film, COP film, PPS film, etc. Preferably, the S4 liquid adhesive includes, but is not limited to, acrylic resin or epoxy resin liquid adhesive, high temperature resistant adhesive, anti-particle migration adhesive, ABF adhesive, BT adhesive, PI adhesive, PAI adhesive, FPA adhesive, MPI adhesive, LCP adhesive, PTFE adhesive, PPS adhesive, and semiconductor material adhesive for high-frequency superconducting precision circuit boards. Preferably, the tunnel oven has four heating and baking zones, including a first heating and baking zone, a second heating and baking zone, a third heating and baking zone, and a fourth heating and baking zone. The temperature range of the first heating and baking zone is 60℃-100℃, the temperature range of the second heating and baking zone is 100℃-150℃, the temperature range of the third heating and baking zone is 100℃-500℃, and the temperature range of the fourth heating and baking zone is 60℃-150℃. Alternatively, an extended oven may be added according to the product requirements of the coating material.

[0080] Preferably, the sputtering process includes the following steps: S1. Evacuate the base vacuum of the coating chamber to 1~2×10-Pa to reduce the pressure of the residual gas in the coating chamber; S2. Adjust the argon gas pressure to 2-5 Pa, apply a bias voltage of 600-900 V to the dielectric layer, with a bias voltage duty cycle of 10-30%, and clean the dielectric layer before sputtering to desorb the adsorbed gases on the walls of the coating chamber and the surface of the internal components. Thoroughly purify the dielectric layer to ensure that it is as free from contamination as possible or free from particulate contaminants. Clean for 1-20 minutes. S3. Evacuate the coating chamber pressure to a background vacuum level lower than 1~2×10³Pa; adjust the working gas pressure from 3 to 7×10¹Pa to the dielectric layer bias voltage from 100 to 400V, the bias voltage duty cycle from 10 to 30%, and the sputtering duty cycle from 10 to 60% under these conditions.

[0081] Preferably, the metallic material is any one of copper, nickel, cadmium, chromium, zinc, titanium copper, ITO, tin, indium, or nano silver. Preferably, the metal material is copper foil, and the electroplating process of the copper foil includes the following steps: The current density for copper foil plating in the first step electrolyte is 5-20 A / dm2, and the time is 1-4 s; In the second step, the current density for copper foil plating in the electrolyte is 20-50 A / dm2, and the time is 1-4 s. In the third step, the current density for copper foil plating in the electrolyte is 50-100 A / dm2, forming an ultra-thin copper foil layer of 0.1-5 μm.

[0082] Preferably, the electrolyte for electroplating the ultra-thin copper foil layer comprises: The electrolyte contains 50-100 g / L copper ions, 100-250 g / L acid, 30-60 ppm SPS, 50-100 ppm gelatin, and 10-50 ppm chloride ions. Preferably, the electrolyte temperature is 40-60°C. Preferably, the equipment includes: At least one material processing unit: it includes a material unwinding roller arranged sequentially along the processing direction and a material to be processed conveyed by the material unwinding roller. The material to be processed includes, but is not limited to, any one of the following films: PI film, MPI film, LCP film, PTFE film, PET film, high temperature resistant PET film, PEN film, PPO film, COP film, PPS film, etc. At least one sputtering device is used to convey the dielectric layer film to the sputtering device using an unwinding roller, and the sputtering device sputters a metal material layer with a thickness of 0.1 nanometers / micrometers to 5 micrometers onto the dielectric layer film; Or at least one electroplating device, which uses unwinding rollers to convey the dielectric layer film to the electroplating device, and the electroplating device electroplats a metal material layer with a thickness of 0.1 nanometers / micrometer to 5 micrometers onto the dielectric layer film; The first composite unit includes a PET release film conveying device and a first pressing device arranged sequentially along the processing direction. The first pressing device composites the PET release film onto a sputtered / electroplated metal material layer. At least one coating apparatus is used to coat liquid adhesive onto the dielectric layer film or onto the metal material layer; At least one drying tunnel oven is used to bake a dielectric film or metal material layer with liquid adhesive in the tunnel oven at 80-200 degrees Celsius, so that the liquid adhesive forms a semi-cured adhesive layer on the dielectric film or metal material layer. The second composite unit includes an unwinding device, a second pressing device, and a second pressing device arranged sequentially along the processing direction to laminate the release film onto the semi-cured adhesive layer. Preferably, the equipment includes: a circuit board conveying device, a composite high-temperature pressing device, an FRCC material unwinding device, a winding device, and circuit board production equipment. First, the adhesive protective film layer of the ultra-thin FRCC material is peeled off. The winding device then winds up the adhesive protective film peeled off from the FRCC material. The unwinding device conveys the ultra-thin FRCC material to the composite high-temperature pressing device. Simultaneously, the circuit board or composite material conveying device conveys the circuit board or composite material to the composite high-temperature pressing device. The high-temperature pressing device presses and cures the circuit board or composite material and the semi-cured layer of the ultra-thin FRCC material into a single unit. The release film layer of the metal material layer of the ultra-thin FRCC material is peeled off. The winding device winds up the release film layer of the metal material layer. The metal material layer of the ultra-thin FRCC material is then processed using the circuit board production equipment according to actual needs.

[0083] Preferably, the composite high-temperature pressing equipment is a double steel strip press, which is divided into a preheating zone, a pressing and forming zone, and a cooling zone. The circuit board and FRCC material to be pressed are fed into the press through the feeding system and preheated to 160-220 degrees Celsius to improve the plasticity of the FRCC material. Then, it enters the pressing zone and is pressed and formed under the pressure of the double steel strip. The pressing pressure is 200-1160 PSI, and the forming temperature is maintained at 200-400 degrees Celsius. After pressing, the product enters the cooling zone to cool to room temperature. The cooled product is discharged from the press through the discharge system.

[0084] The second application method is shown in the following steps: S1. FRCC Material Pre-processing: First, place the roll of FRCC material on the unwinding roller, start the FRCC material processing unit, and convey the FRCC material to the conveying device, where the cutting device punches and / or cuts the FRCC material; after cutting by the cutting device, an open-top pattern is formed on the FRCC material. When an open-top pattern needs to be formed on the FRCC material, the release film of the FRCC material faces the cutting device during the process of the unwinding roller conveying the FRCC material to the conveying device, and the cutting device only cuts out the outline of the corresponding shape on the release film according to the open-top pattern; after punching by the cutting device, positioning holes are formed on the FRCC material. When only positioning holes need to be formed on the FRCC material, there is no limitation on the orientation of the release film during the conveying process of the FRCC material; S2. Release Film Peeling: The FRCC material processed in step S1 is conveyed to the peeling device, which peels off the release film from the FRCC material and conveys the peeled FRCC material to the alignment device. When the release film of the FRCC material has the outline of the opening pattern, the FRCC material after peeling off the release film retains a release film of the corresponding shape at the opening position. The opening pattern on the FRCC material after peeling off the release film is also detected by a pattern detection device, and the detection result is recorded. Then, the opening position is detected by a vision inspection device. The system checks for release film detachment at the designated locations and controls a repair robot to replenish the detached areas with release film of the appropriate shape. The circuit board inspection device inspects the circuit boards conveyed by the circuit board conveyor and records the results. Horizontal positioning rollers and horizontal guide rollers ensure the FRCC material after release film removal is conveyed horizontally and parallel to the circuit board. Simultaneously, an alignment system aligns the positioning holes and / or opening patterns on the FRCC material with those on the circuit board. The aligned FRCC material and circuit board are then pre-pressed between two pre-pressing rollers before being conveyed to the heat press. The circuit board is subjected to hot pressing; the circuit board inspection device inspects the circuit boards conveyed by the circuit board conveying device and records the inspection results. Horizontal positioning rollers and horizontal guide rollers convey the FRCC material after the release film is peeled off horizontally and parallel to the circuit board. At the same time, an alignment system is used to align the positioning holes and / or opening patterns on the FRCC material with the positioning holes and / or opening patterns on the circuit board. The aligned FRCC material and circuit board pass between two pre-pressing rollers for pre-pressing, and then are conveyed to the hot pressing device for hot pressing; the protective film is also conveyed to the pre-pressing device through the protective film unwinding roller, so that the protective film... The FRCC material is covered and, together with the circuit board, passes through a pre-pressing device and a hot-pressing device to complete the bonding of the FRCC material and the circuit board, forming a multilayer board. At this time, the protective film is conveyed to the protective film winding roller for winding. The multilayer board formed by the hot-pressing device is then baked in a tunnel oven to form a multilayer board with stable performance. The multilayer board is conveyed to the drilling inspection system, which drills holes in the FRCC material of the multilayer board to form through holes and blind holes, and inspects and confirms the holes and patterns on the multilayer board. Finally, the multilayer board is wound up or cut into sheets. S3. Multilayer board lamination: When the FRCC material after the release film is peeled off is conveyed to the alignment device, the circuit board conveying device simultaneously conveys the circuit board to the alignment device. At this time, the semi-cured adhesive layer of the FRCC material faces the circuit board. The alignment device completes the alignment of the FRCC material and the circuit board, and then conveys them to the pre-pressing device and the hot pressing device in sequence for pressing to form a multilayer board.

[0085] The application method of the ultra-thin FRCC involves processing FRCC material using a circuit board production equipment with electromagnetic shielding function, including the following steps: S1. Unwind or feed the pre-fabricated circuit board into a conveyor, and then clean it using cleaning equipment. S2. Unwind the ultra-thin FRCC material, use guide rollers to separate the semi-cured adhesive layer release film protective layer, and use take-up rollers to rewind the semi-cured adhesive layer release film protective layer. S3. According to actual needs, the semi-cured adhesive layer of the ultra-thin FRCC material is laminated to one or both sides of the circuit board with the circuit board of the fabricated circuit board. S4. Pressing with a pressing equipment: The circuit board obtained in S3 is pressed with a pressing equipment at a high temperature. The pressing temperature is less than 500 degrees Celsius and greater than 30 degrees Celsius. The hot pressing pressure is 10-800 psi and the hot pressing time is 1-60 min. After hot pressing, the semi-cured adhesive layer is completely cured and integrated with the circuit board. S4. The circuit board obtained from the oven baking line S4 is pressed into a multilayer circuit board and sent into the tunnel oven. The tunnel oven includes 3-6 heating and baking zones or the number of oven sections can be extended according to product requirements. Each heating and baking zone is 2-9 meters long and the temperature does not exceed 500℃. The circuit board is baked in sections by passing through several heating and baking zones in the tunnel oven at a speed of 1-30m / min to further solidify the circuit board and stabilize its performance. S5. Electroplating or sputtering copper layers onto the surface of the circuit board obtained in S4 using electroplating or sputtering equipment to increase the thickness of the circuit board lines and the circuit board shielding layer. S6. The circuit board obtained in S5 is manufactured into circuits using the circuit board manufacturing process. At the same time, the copper layer corresponding to the area of ​​the circuit board that requires EMI electromagnetic shielding and heat conduction is retained. The copper layer constitutes the shielding layer or heat conduction layer of the circuit board, and has the function of shielding electromagnetic or conducting heat for the circuit board. Preferably, the anti-particle migration adhesive layer is composed of component a and component b, wherein component a is an acylhydrazine compound; and component b is a sulfur-containing phenyl phosphite organic compound, and the mass ratio of component a to component b is 1:(0.5-5).

[0086] Preferably, component a comprises one or more of n,n'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine, (3,5-di-tert-butyl-4-hydroxyphenyl)propionate oxaloyl(diimino-2,1-ethylidene) ester, n,n'-diacetyl adipate dihydrazine, 1,2-bis(2-hydroxybenzoyl)hydrazine, salicylhydrazine, and 3-salicylamido-1,2,4-triazole; component b is 2-(1,1-dimethylethyl)-4-[[5-(1,1-dimethylethyl)-4-hydroxy-2-methylphenyl]thio]-5-methylphenol-1,1',1”-phosphite; the mass ratio of component a to component b is 1:(1-2).

[0087] Compared with the prior art, the beneficial effects of this utility model are: The present invention discloses a production process and equipment for ultra-thin FRCC, which has at least one of the following beneficial effects during use: 1. The ultra-thin FRCC material, when applied to circuit boards with electromagnetic shielding functions, saves material. The material, with its copper layer, dielectric layer, and semi-cured layer laminated onto the inner core board, forms a layered structure from top to bottom: copper layer, dielectric layer, semi-cured adhesive layer after high-temperature pressing, a filling circuit layer, dielectric layer, a mixed layer of circuit and adhesive after high-temperature pressing, filling, adhesive, and protective circuit adhesive, dielectric layer, and an outer copper foil layer. After removing the release film or release paper, the FRCC material only requires one roll-to-roll or sheet-by-sheet lamination, followed by high-temperature lamination to allow the inner semi-cured adhesive to withstand high temperatures and... After the flat extrusion filling of the inner circuit core board is bonded and pressed together and cured, it can also be produced in a roll-to-roll process. Then, multi-layer structure products are designed and manufactured for circuits, shielding, and thermal conductivity. For example, when making shielding functions, the copper layer is etched off on the surface of the finished product, and the copper PI surface can replace the traditional insulating cover film layer on the surface of the circuit board. The reserved copper foil layer replaces the traditional EMI material layer. The traditional cover film material structure requires separate equipment and personnel for the process, and also requires multiple engineering processes and material combinations to form this material. It is a traditional material that is PI coated with adhesive semi-cured and then laminated with release paper layer. When using it, it is necessary to cut the window of this material to reserve the window. Then, the inner core board, which is the circuit dielectric layer, is made. After the core board is made, the release paper or release film on the cover film is peeled off, and after false pressing and alignment, high temperature pressing and transfer are performed to combine with the inner core board to protect the inner circuit and fill the circuit spacing for protection and related performance standards. For products that require shielding performance, a shielding film material needs to be laminated on the surface of the cover film. The structure and use of the shielding film material require another set of equipment engineering. The process involves sputtering a copper or silver layer onto PI and PET, then applying adhesive and allowing it to semi-cur before laminating a release film or release paper. When using it, die-cutting is required to reserve the shape of the shielding area, and other excess parts are removed. Then, the release film or release paper is peeled off, and the core board is laminated onto the core board product with a cover film at low temperature. Then, the core board is laminated and cured at high temperature. The process also requires the addition of high-temperature release film protection and repeated operation of equipment, which wastes manpower, materials, related consumables, and electricity, and increases industrial waste emissions.The use of FRCC (Flat Metal Concrete Cemented Copper) material has altered the thickness of the original product design and reduced the use of cover film and EMI film, improving product flatness performance. It also eliminates the need for complex material processing and increased consumables, while reducing equipment usage. In engineering processes, the die-cutting and alignment processes involving multiple high-temperature pressings are handled by FRCC material, where the copper foil layer area pre-reserved through pattern etching can replace the traditional shielding film and EMI shielding layer. The PI (Polymer Injection Molding) area after copper etching replaces the traditional cover film. Laser windowing allows for more precise exposure of internal chip components and SMT soldering positions, resolving product quality issues such as excess adhesive. This improves upon various product design requirements, such as thinner and more flexible designs, without the need for complex engineering processes and multiple pressings. Using consumable materials to create shielding performance not only replaces the original shielding effect but also facilitates thermal design applications, changing traditional product design. Besides reserving copper layers in areas requiring shielding, it allows for multi-layer interconnection circuitry and innovative product design needs in other locations, without affecting the overall product flatness or causing unevenness, and eliminating issues related to later SMT component bonding. Using this material reduces the need for traditional shielding film materials and cumbersome engineering processes in traditional product manufacturing, such as mold cutting and bonding processes, multiple pressing processes, and the use of auxiliary materials like PET release film, saving labor costs. The process simplifies the design of products, including electrical equipment and usage frequency. The manufacturing process is simple and easy to operate. The wound circuit board can be produced in rolls and sheets. New circuits can be created through the circuit board manufacturing process. However, existing electromagnetic shielding circuit board manufacturing requires adding a copper or silver layer to the film to act as a shielding layer, then applying adhesive, and finally curing it in a tunnel oven before laminating it with release paper to form a multi-layer composite shielding film material. In the production of the circuit board requiring shielding, the shielding film material must first be cut to the required shape for the shielding area of ​​the circuit board. Then, the release film on the shielding film needs to be removed before proceeding with the fabrication of the circuit board. The process involves pre-heat-pressing the area requiring shielding performance onto the surface of the board with an insulating layer cover film. After die-cutting, the shielding film is aligned and pasted, then transferred to the product via low-temperature pressing. Only after the shielding film is pasted on top is high-temperature pressing performed to fully bond the product to the substrate core surface. This process is cumbersome and complex, leading to product yield and quality risks. It also necessitates the use of auxiliary materials like release film during high-temperature pressing, increased equipment usage frequency, and multiple product lamination processes, consuming manpower and electricity, and increasing product risk. The surface flatness of the product also affects its performance, causing unevenness during SMT component bonding, making it difficult to install multiple layers, addressing design defects, and limiting application scenarios. This requires re-applying adhesive, re-aligning, and pressing single- or double-sided boards, making the production process cumbersome and unable to meet production demands.

[0088] 2. First, the PET dielectric layer surface is released to facilitate the peeling of the electroplated copper foil. This eliminates the difficulties in processing very thin films and the need for a carrier material for support and repeated processing to increase the thickness of the base film. The new material only uses thick PET for electroplating or sputtering; the copper foil only needs to be electroplated onto the released, thick PET surface, simplifying the production process. It eliminates the technical difficulties of double-sided copper plating of 3-5 micron PET films used in current collectors, as well as the challenges of uniform coating during magnetron sputtering and the need for a carrier layer for composite support material flatness and tension during coating. Furthermore, it allows for reuse of... Composite carrier materials, when used for membrane structure support and peeling, present challenges in controlling product yield. Depending on material requirements, a release-type peelable support base film with the required thickness is used. During the transfer process, sputtering and electroplating are used to form a thick carrier metal film layer, creating a metal layer plus a release carrier layer membrane structure. This can be a single-sided or double-sided structure. Then, a coating device is used to coat the metal side. Two rolls of material with metal coating are pressed together and then subjected to a high-temperature rolling press to transfer and cure the metal coating layer with adhesive. This process also allows the carrier release film material to be subjected to certain temperatures, causing the PET to expand and contract, resulting in inconsistent physical properties of the metal layer. This makes it easy for subsequent processes to fail. The separation mechanism separates and peels off the carrier film, forming a composite material structure with a metal-adhesive-metal intermediate layer and two metal layers on both sides. This also saves the original composite current collector base film and support carrier film, reducing production costs. Using the equipment disclosed in this utility model, the copper foil on the dielectric layer is peeled off, and the two peeled copper foil layers are laminated together through a coating process, recombining them into a "metal-polymer-metal sandwich structure". It can also be used in carrier copper foil laminated circuit board materials, the structure of which is a high-temperature carrier PET release film + conductive layer (copper, silver, ITO, titanium copper, etc. conductive layer) + semi-cured dielectric layer (ABF, BT, anti-particle epoxy resin, high-frequency epoxy resin, PTFE, PFA, FP). A, PI, MPI, LCP, PPO, PPS, resin-synthesized aluminum nitride powder, etc.) + release film and release paper protective layer; used in ultra-thin precision circuit board surface transfer technology and other fields. Its structure is that a conductive metal layer is plated on one side of the carrier high-temperature PET release film, and then a dielectric liquid material is coated on the conductive metal layer for semi-curing. Then, the semi-cured surface is laminated with a release film for protection and to prevent contamination. When using carrier copper foil in the production of multilayer circuits, the release film is peeled off, and the semi-cured dielectric layer is laminated and pressed onto the inner core board to form a stacked structure. After the high-temperature lamination and transfer are completed, the high-temperature release film on the surface of the carrier copper foil is peeled off to proceed to the next precision circuit process.Because the adhesive used in coating equipment can be pre-mixed to meet different needs, anti-ion migration materials such as "mixtures of acylhydrazine compounds and sulfur-containing phenyl phosphite organic compounds" can be added to prevent short circuits caused by copper particles migrating through the dielectric layer in the current collector material of the power battery. Aluminum nitride powder can also be added to increase the temperature resistance of the dielectric layer; this diversification of current collector materials meets the growing demands of new energy technologies.

[0089] 3. Compared to the traditional process of laminating and bonding single-sided and double-sided panels using materials consisting of release film, pre-cured adhesive, and release film: (1) By coating process, the semi-cured adhesive layer is combined with the traditional single-sided board to form a new type of FRCC material. Combined with the multilayer board production line of this utility model, the automated production of multilayer circuit boards is realized, the processing accuracy and yield of multilayer boards are improved, the production process of multilayer circuit boards is simplified, the amount of release film used can be reduced and the release film can be reused, effectively saving material costs and labor costs, reducing water, electricity and gas consumption, and reducing the generation and discharge of industrial waste. (2) FRCC material is directly bonded to the circuit board, and air bubbles pressed into the interlayer can be discharged from the through holes on the circuit board, which solves the problem of air bubbles being easily pressed into the interlayer of multilayer boards and improves the performance reliability of multilayer circuit boards. (3) After each alignment, the alignment detection module is used to detect and analyze the overlap of the core board to avoid the offset phenomenon after the core board is pressed. Each alignment detection uses the standard range of the first alignment detection as a reference to prevent the problem that the multilayer board has a large offset due to the accumulation of layers, even if the single alignment detection is qualified.

[0090] (4) Compared with the existing multilayer circuit board capping process, the FRCC material capping process uses high-temperature PET instead of PI for capping. The process flow includes: laser patterning on PET → peeling off the PET outside the pattern → alignment → multilayer lamination → etching → cutting → capping. The advantages are as follows: a. Saves material costs: eliminates the cost of the inner CVL cover film + PI protective film; b. Saves process flow: eliminates the lamination process of the cover film + PI protective film; c. Improves process accuracy: the alignment of the opening area is only affected by the accuracy of the circuit, which is a qualitative improvement in alignment accuracy compared with the traditional process; d. The material produced by using high-temperature release film can be directly laser-cut for opening, and the release film can be reused, which can reduce costs and improve competitiveness.

[0091] E. The PI layer in the FRCC etched area replaces the traditional cover film, resulting in better product flatness. Unlike traditional cover films that require pre-opening windows to expose the pads and alignment and lamination processes, the PI layer in the FRCC surface copper foil etched area directly exposes the pad positions via laser scanning, eliminating issues such as excess adhesive. It also offers higher precision, requiring only post-laser chemical treatment. This not only replaces the traditional cover film and reduces product thickness but also minimizes material consumption, manpower, and equipment waste in the manufacturing process, thus reducing industrial waste emissions.

[0092] (5) The use of FRCC has revolutionized the traditional PCB manufacturing process and some product designs, innovating new processes and product designs, and changing the traditional material supply chain. Using FRCC and RCC in PCB manufacturing can reduce the thickness of the original traditional PCB and the manufacturing process. For example, in the production of multilayer PCBs, the inner core board is made of CCL (single or double-sided glass fiber cloth with copper foil) as the inner layer circuit. After forming the inner core board, RCC and FRCC are directly covered on it for multilayer stacking and high-temperature pressing to create interconnected multilayer circuits. This not only eliminates the use of the original traditional CCL and PP sheet (a material containing adhesive in glass fiber cloth), but also significantly reduces the product thickness. There is no need for the traditional material cutting process of stacking aluminum sheet auxiliary materials and then putting them into the drilling machine one stack at a time for drilling. After FRCC and RCC are directly covered on the inner core board and bonded at high temperature, laser drilling and picosecond drilling are used. After pretreatment, photosensitive film is applied for pattern making, followed by development, electroplating, etching to remove the photosensitive film layer and form the required circuit pattern. If multiple layers of FRCC and RCC are required, the process can be repeated to achieve the multi-layer structure required by the product. In addition, FRCC copper foil can not only be used to make circuits, but also to directly laser remove BGA and finely bond SMT component positions. The PI part with copper etched off can replace the original traditional ink solder mask layer. The insulation effect and temperature and humidity resistance of PI far exceed the protection effect of the original traditional ink. FRCC can not only replace the traditional CCL and PP in traditional multi-layer PCBs, but also make the circuit more precise and fine. It can also be used on rigid-flex boards, multi-layer flexible boards, and various circuit boards that require bending and twisting. With FRCC, the thin roll material is directly rolled and covered, and various circuit interconnection and interconnection are made using new processes and technologies.

[0093] This ultra-thin FRCC material is applied to the production of composite copper foil current collectors. First, the existing PP, PET, and PI organic support layers undergo release treatment to facilitate the peeling of the electroplated copper foil. This eliminates the need for a combination of thin and thick support layers, using only the thick support layer for electroplating or sputtering. The copper foil is simply electroplated onto the release-treated thick support layer, simplifying the production process. It eliminates the need for repeated peeling and bonding of the combined thin and thick support layers, saving on thin support layers and reducing production costs. The copper foil on the subsequent support layer is then peeled off, and the two peeled copper foil layers are pressed together using a coating process, recombining them into a "metal-polymer-metal sandwich structure." Since the adhesive in the coating equipment can be pre-mixed to meet different needs, anti-ion migration materials such as "mixtures of hydrazide compounds and sulfur-containing phenyl phosphite organic compounds" can be added to prevent short circuits caused by copper particles migrating through the support layer in the power battery current collector material. Aluminum nitride can also be added to increase the temperature resistance of the support layer. This diversification of current collector materials meets the growing demands of new energy technologies.

[0094] (6) FRCC material consists of a copper dielectric layer and a semi-cured adhesive layer. It can also solve the problem of asymmetrical structural applications. The semi-cured side can contact the thick copper lamination to create asymmetrical materials and then asymmetrical circuit boards, meeting the needs of different product designs and applications. It can be customized for high-current products to meet corresponding design requirements and is applied in battery product design and medical device component fields. Different customized FRCCs can also meet the design requirements of 5G, 6G and other products.

[0095] (7) FRCC material can also realize the production of asymmetrical products. For example, the adhesive side of FRCC material can be bonded to metal materials of different thicknesses and different metals to meet the asymmetrical product design requirements. For example, for the battery protection board of 3C products, one side is signal management and power management. Usually, the design cannot meet such structural requirements. Signal management considers fine lines and dense chip SMT soldering, but the heat resistance and voltage cannot be too large. Then the power supply needs high requirements such as voltage resistance and resistance. In particular, fast charging has very high requirements for metal layer thickness and conductivity. For the asymmetrical product design requirements, the new FRCC material can meet these requirements. The precision circuit part can be made by using the copper layer of FRCC material to meet the requirements of precision circuit and chip control management design circuit. The adhesive layer of FRCC material can bond thick copper metal or titanium copper, aluminum, etc. to meet the power design layer requirements. The thickness of thick copper metal or titanium copper includes 1oz-6oz, forming a new material for customized solutions for various asymmetrical product designs and requirements. It can also solve the application of steel sheets in camera modules, eliminating the need for conductive adhesives and complex engineering processes. FRCC material is used to directly attach the required metal layers such as aluminum and steel sheets. After fabrication, laser drilling is performed at the locations where conductive contacts are required in the BGA to form blind or through holes, depending on the requirements. One or both sides of the metal layer of the laser-drilled product are masked with a protective film or photosensitive ink. The exposed holes are chemically treated to clean the inside, followed by electroplating to connect the steel sheets and aluminum layers for grounding. This solves the traditional requirements for conductive adhesives and engineering processes. Previously, complete product designs required combining this product with other products, such as double-sided or multi-layered laminated circuit boards, to form an integrated product structure. This addressed the need for interconnectivity in product design and engineering processes. The product is then shaped and cut according to product requirements, resolving the traditional design requirement for conductive adhesives.

Claims

1. An electromagnetically shielded functional electronic circuit board, characterized in that, include: A core board with inner layer circuitry; A functional composite layer covering at least one surface of the core board, the functional composite layer comprising a dielectric layer with a thickness of 1 to 25 micrometers and a metallic material layer with a thickness of 0.1 nanometers to 5 micrometers; The metal material layer is patterned and retained in a predetermined shielding area to form an electromagnetic shielding layer; it is removed in the unshielded area, exposing the dielectric layer in that area to form an insulating protective layer.

2. The electromagnetic shielding functional electronic circuit board according to claim 1, characterized in that, The functional composite layer is derived from an ultra-thin metal layer flexible composite material, which includes the metal material layer, the dielectric layer, and a semi-cured adhesive layer for hot-pressing the composite material with the core board.

3. The electromagnetic shielding functional electronic circuit board according to claim 1, characterized in that, The metallic material layer is also patterned to form heat conduction paths or grounding lines in specific areas.

4. The electromagnetic shielding functional electronic circuit board according to claim 1, characterized in that, The dielectric layer is selected from polyimide (PI), modified polyimide (MPI), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), or polyphenylene sulfide (PPS).

5. The electromagnetic shielding functional electronic circuit board according to claim 1, characterized in that, The core board is a flexible circuit board, a rigid circuit board, or a rigid-flex circuit board.

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