Metal-based circuit board and metal-based circuit board manufacturing method

Abstract

The invention belongs to the technical field of metal-based circuit boards, and particularly relates to a metal-based circuit board and a manufacturing method of the metal-based circuit board. According to the manufacturing method, synchronous pretreatment is achieved through the metal substrate treatment step and the aluminum foil forming step, and compared with a traditional manufacturing method of the metal-based circuit board, the manufacturing method has the advantages that the production process can be shortened, and meanwhile certain production efficiency is stably improved. And moreover, a staged immobilization process is adopted to be matched with the multi-component high-thermal-conductivity insulating pressure-sensitive film, so that the problems of adhesive layer flowing, copper foil warping and the like caused by single-stage curing can be avoided, and the consistency of a final product of the metal-based circuit board is ensured.

Description

Technical Field

[0001] This invention belongs to the field of metal-based circuit board technology, specifically relating to a metal-based circuit board and a method for manufacturing a metal-based circuit board. Background Technology

[0002] Metal-based circuit boards (PCBs) are a special type of circuit board with a metal substrate. They are composite boards consisting of three layers: a metal base layer, an insulating layer, and a circuit layer (copper cladding). Unlike traditional FR-4 fiberglass boards, the primary design purpose of metal-based PCBs is to rapidly dissipate heat generated by high-power components, preventing overheating failure.

[0003] In related technologies, the manufacturing process of metal-based circuit boards requires multiple processing steps, including substrate treatment, circuit forming, lamination, and curing. Furthermore, the manufacturing of metal-based circuit boards often employs a subtractive chemical etching process, the core of which involves removing excess copper foil using acid-base etching solutions to form the circuit.

[0004] However, this method is not only complex, but also requires repeated engraving to complete. The entire manufacturing process is time-consuming, labor-intensive, and incurs huge costs. Summary of the Invention

[0005] The purpose of this invention is to provide a metal-based circuit board and a method for manufacturing a metal-based circuit board, so as to solve the problems of complex and time-consuming production processes in the traditional manufacturing methods of metal-based circuit boards.

[0006] The specific technical solution adopted by this invention is as follows: <First Aspect> A metal-based circuit board and a method for manufacturing the metal-based circuit board include the following steps: Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0007] In some possible implementations, the high thermal conductivity insulating varistor comprises, by weight, the following components: 100 parts E51 epoxy resin, 15-22 parts butyl methacrylate resin, 13-16 parts isooctyl acrylate resin, 18-22 parts dicyandiamide, 8-10 parts urea-formaldehyde resin, 0.8-1.5 parts peroxide initiator, 0.8-1.5 parts imidazole accelerator, 120-150 parts aluminum nitride powder, and 80-90 parts silicon carbide powder.

[0008] In some possible implementations, the method for preparing the high thermal conductivity insulating varistor film includes: Step S4: Mix all components evenly to obtain a colloidal substrate. Cast the colloidal substrate onto a release film at 55-65℃ and keep it warm for 6-9 minutes to cure it into a film. The colloidal impurities generated during casting are recycled and reused. The uncured epoxy resin is reserved for subsequent staged curing.

[0009] In some possible implementations, the thickness of the high thermal conductivity insulating pressure-sensitive film is 60-150 μm, and the casting rate is 1-1.5 m / min; The hot-pressing bonding and hot-pressing composite temperatures in steps S1 and S2 are both 50-80℃.

[0010] In some possible implementations, the peroxide initiator is dicumyl peroxide (DCP), and the imidazole promoter is 2-methylimidazole; The silicon carbide powder has a particle size of 2-4 μm, and the aluminum nitride powder has a particle size of 4-6 μm; The dicyandiamide, when combined with the urea-formaldehyde resin, works synergistically with the imidazole accelerator.

[0011] In some possible implementations, the staged curing is a three-stage curing or a four-stage curing; The three-stage curing process is as follows: 80-90℃ / 20-30min, 120-130℃ / 20-30min, and 145-150℃ / 40-45min. The four-stage curing process is as follows: 70-80℃ / 20-30min, 90-110℃ / 20-30min, 125-135℃ / 10-20min, and 145-150℃ / 30-35min.

[0012] In some possible implementations, the hole is metallized after drilling, and then chemically deposited copper and electroplated copper are applied sequentially to form a conductive homolayer on the hole wall. The waste liquid from hole metallization is purified and the useful components are recovered. The finished product inspection includes appearance, electrical performance, and dimensional inspection.

[0013] In some possible implementations, the solder resist forming involves coating solder resist ink, pre-curing it, and then exposing and developing it to form solder pad windows. The surface treatment involves covering the pad area with an OSP organic protective film solder, an immersion gold layer, an immersion tin layer, or a tin spray layer. The waste liquid and waste residue after the surface treatment are purified and recycled for reuse.

[0014] In some possible implementations, the metal substrate is made of aluminum, copper, or iron, and its thickness is 1.0 mm to 3.0 mm. The aluminum foil is an electrolytic copper foil or a rolled copper foil, with a thickness of 18μm-70μm.

[0015] <Second aspect> A metal-based circuit board, prepared by any one of the preparation methods described in the first aspect, comprises a conductive copper foil layer, an insulating and thermally conductive layer, and a metal base layer stacked from top to bottom, wherein the insulating and thermally conductive layer is tightly bonded to the conductive copper foil layer and the metal base layer to achieve electrical insulation and heat transfer.

[0016] The technical effects achieved by this invention are as follows: I. This invention achieves simultaneous pretreatment of the metal substrate processing and aluminum foil forming steps, which, compared to traditional metal-based circuit board manufacturing methods, can shorten the production process while steadily improving production efficiency. Furthermore, the use of a staged immobilization process adapted to a multi-component, high thermal conductivity, insulating, and pressure-sensitive film avoids problems such as adhesive layer flow and copper foil warping caused by single-stage curing, thus ensuring the consistency of the final metal-based circuit board product.

[0017] Second, this invention reduces the low recycling rate problem in traditional manufacturing processes by classifying and recycling impurities generated during the manufacturing process of metal-based circuit boards. This not only significantly reduces production costs but also avoids the pollution problem caused by etching waste liquid and contributes to green production, thus responding to the concept of green and environmentally friendly development.

[0018] Third, this invention is adaptable to metal substrates of different materials such as aluminum, copper, and iron, as well as different types of copper foil such as electrolytic copper foil and rolled copper foil. Furthermore, surface treatments can be flexibly selected, including OSP, immersion gold, immersion tin, and tin spraying, thus meeting the application needs of various scenarios such as LED lighting, power modules, and automotive electronics.

[0019] IV. This invention utilizes a multi-component system comprising a compound resin of butyl methacrylate and isooctyl acrylate, a compound curing agent of dicyandiamide and urea-formaldehyde resin, and a compound thermally conductive powder of aluminum nitride and silicon carbide powder, combined with a gradient particle size design, to construct a three-dimensional, highly efficient thermally conductive network for metal-based circuit boards. This structural design not only improves the thermal conductivity, peel strength, and breakdown voltage of metal-based circuit boards but also overcomes the defects of uneven thermal conductivity and insufficient adhesion caused by single materials in traditional manufacturing processes. Attached Figure Description

[0020] Figure 1 This is a flowchart of the manufacturing process of the metal-based circuit board manufacturing method provided by the present invention; Figure 2 This is a bar chart comparing the breakdown voltage in various embodiments and comparative examples of the metal-based circuit board manufacturing method provided by the present invention. Figure 3 This is a bar chart comparing the peel strength of various embodiments and comparative examples in the metal-based circuit board manufacturing method provided by the present invention. Figure 4 This is a line graph comparing the thermal conductivity of various embodiments and comparative examples in the metal-based circuit board manufacturing method provided by the present invention; Figure 5 yes Figure 2-4 Radar display diagrams of the various test results. Detailed Implementation

[0021] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0022] like Figure 1-4 As shown, the present invention provides a method for manufacturing a metal-based circuit board, comprising the following steps: Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0023] The following detailed embodiments illustrate the metal-based circuit board and its manufacturing method provided by the present invention.

[0024] <Example 1> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 15 parts of butyl methacrylate resin, 13 parts of isooctyl acrylate resin, 18 parts of dicyandiamide, 8 parts of urea-formaldehyde resin, 0.8 parts of dicumyl peroxide (DCP), 0.8 parts of 2-methylimidazole, 120 parts of aluminum nitride powder (4μm), and 80 parts of silicon carbide powder (2μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 6 minutes to allow some components to cure into a film. Colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0025] The aforementioned high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 50°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of high thermal conductivity insulating pressure-sensitive films. Furthermore, a 35 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0026] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 50°C using a hot-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in three stages: 80°C / 20min, 120°C / 20min, and 145°C / 40min, and then allowed to cool naturally after curing.

[0027] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0028] <Example 2> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 16 parts of butyl methacrylate resin, 15 parts of isooctyl acrylate resin, 20 parts of dicyandiamide, 9 parts of urea-formaldehyde resin, 0.9 parts of dicumyl peroxide (DCP), 0.8 parts of 2-methylimidazole, 120 parts of aluminum nitride powder (4μm), and 80 parts of silicon carbide powder (2μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 6 minutes to allow some components to cure into a film. Colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0029] The high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 55°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of the high thermal conductivity insulating pressure-sensitive film. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0030] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 55°C using a hot-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in three stages: 80°C / 20min, 120°C / 20min, and 145°C / 40min, and then allowed to cool naturally after curing.

[0031] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0032] <Example 3> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 16 parts of butyl methacrylate resin, 14 parts of isooctyl acrylate resin, 19 parts of dicyandiamide, 9 parts of urea-formaldehyde resin, 1.0 part of dicumyl peroxide (DCP), 0.9 parts of 2-methylimidazole, 130 parts of aluminum nitride powder (4μm), and 85 parts of silicon carbide powder (2μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 8 minutes to allow some components to cure into a film. Colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0033] The high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 55°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of the high thermal conductivity insulating pressure-sensitive film. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0034] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 55°C using a heat-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in four stages: 70-80°C / 20-30 min, 90-110°C / 20-30 min, 125-135°C / 10-20 min, and 145-150°C / 30-35 min, followed by natural cooling.

[0035] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0036] <Example 4> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 16 parts of butyl methacrylate resin, 15 parts of isooctyl acrylate resin, 21 parts of dicyandiamide, 9 parts of urea-formaldehyde resin, 1.1 parts of dicumyl peroxide (DCP), 0.8 parts of 2-methylimidazole, 125 parts of aluminum nitride powder (4μm), and 90 parts of silicon carbide powder (2μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 8 minutes to allow some components to cure into a film. Colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0037] The aforementioned high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 60°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of high thermal conductivity insulating pressure-sensitive films. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0038] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 60°C using a hot-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in four stages: 70-80°C / 20-30 min, 90-110°C / 20-30 min, 125-135°C / 10-20 min, and 145-150°C / 30-35 min, followed by natural cooling.

[0039] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0040] <Example 5> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 20 parts of butyl methacrylate resin, 15 parts of isooctyl acrylate resin, 22 parts of dicyandiamide, 10 parts of urea-formaldehyde resin, 1.4 parts of dicumyl peroxide (DCP), 1.2 parts of 2-methylimidazole, 140 parts of aluminum nitride powder (3μm), and 90 parts of silicon carbide powder (2μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 5 minutes to allow some components to cure into a film. Colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0041] The high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 55°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of the high thermal conductivity insulating pressure-sensitive film. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0042] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 55°C using a heat-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in four stages: 70-80°C / 20-30 min, 90-110°C / 20-30 min, 125-135°C / 10-20 min, and 145-150°C / 30-35 min, followed by natural cooling.

[0043] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0044] <Example 6> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 16 parts of butyl methacrylate resin, 15 parts of isooctyl acrylate resin, 22 parts of dicyandiamide, 10 parts of urea-formaldehyde resin, 1.5 parts of dicumyl peroxide (DCP), 1.5 parts of 2-methylimidazole, 150 parts of aluminum nitride powder (4μm), and 88 parts of silicon carbide powder (3μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 8 minutes to allow some components to cure into a film. The colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0045] The aforementioned high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 60°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of high thermal conductivity insulating pressure-sensitive films. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0046] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 60°C using a heat-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in three stages: 80-90°C / 20-30 min, 120-130°C / 20-30 min, and 145-150°C / 40-45 min, followed by natural cooling.

[0047] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0048] <Example 7> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 16 parts of butyl methacrylate resin, 14 parts of isooctyl acrylate resin, 19 parts of dicyandiamide, 10 parts of urea-formaldehyde resin, 1.5 parts of dicumyl peroxide (DCP), 1.5 parts of 2-methylimidazole, 150 parts of aluminum nitride powder (5μm), and 88 parts of silicon carbide powder (3μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 8 minutes to allow some components to cure into a film. Colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0049] The aforementioned high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 60°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of high thermal conductivity insulating pressure-sensitive films. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0050] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 60°C using a heat-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in three stages: 80-90°C / 20-30 min, 120-130°C / 20-30 min, and 145-150°C / 40-45 min, followed by natural cooling.

[0051] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0052] <Example 8> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 15 parts of butyl methacrylate resin, 13 parts of isooctyl acrylate resin, 22 parts of dicyandiamide, 10 parts of urea-formaldehyde resin, 1.5 parts of dicumyl peroxide (DCP), 1.5 parts of 2-methylimidazole, 150 parts of aluminum nitride powder (5μm), and 90 parts of silicon carbide powder (3μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 7 minutes to allow some components to cure into a film. The colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0053] The aforementioned high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 60°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of high thermal conductivity insulating pressure-sensitive films. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0054] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 55°C using a heat-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in three stages: 80-90°C / 20-30 min, 120-130°C / 20-30 min, and 145-150°C / 40-45 min, followed by natural cooling.

[0055] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0056] <Example 9> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 15 parts of butyl methacrylate resin, 16 parts of isooctyl acrylate resin, 22 parts of dicyandiamide, 8 parts of urea-formaldehyde resin, 1.3 parts of dicumyl peroxide (DCP), 1.5 parts of 2-methylimidazole, 130 parts of aluminum nitride powder (4μm), and 85 parts of silicon carbide powder (3μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 55℃ and kept at that temperature for 6 minutes to allow some components to cure into a film. The colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in the subsequent preparation of pressure-sensitive films), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0057] The aforementioned high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 60°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of high thermal conductivity insulating pressure-sensitive films. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0058] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 55°C using a heat-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in four stages: 70-80°C / 20-30 min, 90-110°C / 20-30 min, 125-135°C / 10-20 min, and 145-150°C / 30-35 min, followed by natural cooling.

[0059] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0060] <Example 10> Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Specifically, by weight, 100 parts of E51 epoxy resin, 15 parts of butyl methacrylate resin, 16 parts of isooctyl acrylate resin, 20 parts of dicyandiamide, 8 parts of urea-formaldehyde resin, 1.3 parts of dicumyl peroxide (DCP), 1.3 parts of 2-methylimidazole, 140 parts of aluminum nitride powder (4μm), and 85 parts of silicon carbide powder (3μm) were mixed and stirred evenly at room temperature to obtain a colloidal substrate. The colloidal substrate was then cast onto a release film at 60℃ and kept at that temperature for 8 minutes to allow some components to cure into a film. Colloidal impurities generated during the casting process were collected (sealed and stored for use as auxiliary materials in subsequent pressure-sensitive film preparation), resulting in a high thermal conductivity insulating pressure-sensitive film with a thickness of 60μm.

[0061] The aforementioned high thermal conductivity insulating pressure-sensitive film was hot-pressed onto the surface of a 2.0 mm thick aluminum plate at 60°C using a hot-pressing machine to obtain an insulating metal substrate. Simultaneously, the film material and oxide impurities from the metal substrate generated during lamination were collected, pulverized, and reused as auxiliary materials for the preparation of high thermal conductivity insulating pressure-sensitive films. Furthermore, a 36 μm thick electrolytic aluminum foil was smoothly laminated onto a PET protective film using a laminating machine. The aluminum foil was then die-cut using a laser die-cutting machine to remove excess aluminum foil (which was melted, purified, and reused). After cooling, the protective film was removed to obtain the conductive circuit pattern.

[0062] Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Specifically, a conductive circuit pattern is hot-pressed onto an insulating metal substrate at 60°C using a heat-pressing machine, and an uncured metal-based circuit board is obtained by bonding with a pressure-sensitive film. The uncured circuit board is then placed in an oven and cured in four stages: 70-80°C / 20-30 min, 90-110°C / 20-30 min, 125-135°C / 10-20 min, and 145-150°C / 30-35 min, followed by natural cooling.

[0063] Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

[0064] <Comparative Example 1> The same steps as in Example 1 were used, except that the curing process was a two-stage curing process, which was 110℃ / 40min and 150℃ / 60min in sequence.

[0065] <Comparative Example 2> The same steps as in Example 2 were used, except that the curing process was a one-stage curing process, which was 150℃ / 60min.

[0066] The metal-based circuit boards prepared in Examples 1-10 and Comparative Examples 1-2 were subjected to performance tests, and the test results are shown in the table below: As shown in the table above, the breakdown voltage of Examples 1-10 is 3.7-4.2kV, the peel strength is 1.32-1.58N / mm, the thermal conductivity is 1.85-2.10W / m・k, and the solderability is 1750-2000s. All these indicators are significantly better than those of metal-based circuit boards made by traditional methods, and the boards have no defects in appearance. This demonstrates the synergistic advantages of the multi-component compound system and the staged curing process in manufacturing.

[0067] This invention employs a component-based compounding approach for the high thermal conductivity insulating varistor film, specifically a compounding design of butyl methacrylate resin and isooctyl acrylate resin, dicyandiamide and urea-formaldehyde resin, and aluminum nitride powder and silicon carbide powder, constructing a three-dimensional, highly efficient thermally conductive and insulating network. This significantly improves the thermal conductivity and breakdown voltage of metal-based circuit boards compared to traditional methods, overcoming the defects of uneven thermal conductivity and insufficient adhesion found in single-material designs.

[0068] Furthermore, Examples 1-10, which employed three- or four-stage curing, exhibited a peel strength consistently above 1.32 N / mm, and a solderability resistance of up to 2000 s, compared to Comparative Examples 1 and 2. In contrast, Comparative Examples 1 (two-stage curing) and 2 (single-stage curing) suffered from uncontrolled curing rates, resulting in insufficient adhesive layer density and a significant decline in various properties. They also exhibited surface defects such as pores and warping, demonstrating that staged curing effectively controls the degree of reactive gelation and ensures product consistency.

[0069] Furthermore, after the impurities (copper foil waste, film material impurities, etc.) in each process of the present invention are recycled and reused, the product performance is no different from that of the unreused system, and is superior to the performance under the traditional manufacturing method, thus achieving a balance between green environmental protection and performance.

[0070] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A method for manufacturing a metal-based circuit board, characterized in that, Includes the following steps: Step S1: A high thermal conductivity insulating pressure-sensitive film is hot-pressed onto the surface of a metal substrate to obtain an insulating metal substrate. At the same time, an aluminum foil is precisely die-cut to form a circuit. The impurities generated during the bonding and die-cutting processes are treated and recycled for reuse to obtain an insulating metal substrate and a conductive circuit pattern. Step S2: The conductive circuit pattern is hot-pressed and composited with the insulating metal substrate, and then bonded with a high thermal conductivity insulating pressure-sensitive film to obtain an uncured metal base circuit board, which is then subjected to a staged curing process. Step S3 involves sequentially performing drilling, solder mask forming, character printing, surface treatment, and shape cutting on the cured metal-based circuit board, and obtaining the target metal-based circuit board after passing the finished product inspection.

2. The method for manufacturing a metal-based circuit board according to claim 1, characterized in that: The high thermal conductivity insulating varistor film comprises, by weight, the following: 100 parts E51 epoxy resin, 15-22 parts butyl methacrylate resin, 13-16 parts isooctyl acrylate resin, 18-22 parts dicyandiamide, 8-10 parts urea-formaldehyde resin, 0.8-1.5 parts peroxide initiator, 0.8-1.5 parts imidazole accelerator, 120-150 parts aluminum nitride powder, and 80-90 parts silicon carbide powder.

3. The method for manufacturing a metal-based circuit board according to claim 2, characterized in that: The method for preparing the high thermal conductivity insulating varistor film includes: Step S4: Mix all components evenly to obtain a colloidal substrate. Cast the colloidal substrate onto a release film at 55-65℃ and keep it warm for 6-9 minutes to cure it into a film. The colloidal impurities generated during casting are recycled and reused. The uncured epoxy resin is reserved for subsequent staged curing.

4. The method for manufacturing a metal-based circuit board according to claim 1, characterized in that: The thickness of the high thermal conductivity insulating pressure-sensitive film is 60-150 μm, and the casting rate is 1-1.5 m / min; The hot-pressing bonding and hot-pressing composite temperatures in steps S1 and S2 are both 50-80℃.

5. The method for manufacturing a metal-based circuit board according to claim 2, characterized in that: The peroxide initiator is dicumyl peroxide (DCP), and the imidazole promoter is 2-methylimidazole; The silicon carbide powder has a particle size of 2-4 μm, and the aluminum nitride powder has a particle size of 4-6 μm; The dicyandiamide, when combined with the urea-formaldehyde resin, works synergistically with the imidazole accelerator.

6. The method for manufacturing a metal-based circuit board according to claim 1, characterized in that: The phased curing process can be either three-stage or four-stage curing. The three-stage curing process is as follows: 80-90℃ / 20-30min, 120-130℃ / 20-30min, and 145-150℃ / 40-45min. The four-stage curing process is as follows: 70-80℃ / 20-30min, 90-110℃ / 20-30min, 125-135℃ / 10-20min, and 145-150℃ / 30-35min.

7. The method for manufacturing a metal-based circuit board according to claim 1, characterized in that: After drilling, the hole is metallized, and then chemical copper plating and electroplating are performed to form a conductive layer on the hole wall. The waste liquid from hole metallization is purified and the useful components are recovered. The finished product inspection includes appearance, electrical performance, and dimensional inspection.

8. The method for manufacturing a metal-based circuit board according to claim 1, characterized in that: The solder resist forming process involves coating solder resist ink, pre-curing it, and then exposing and developing it to form solder pad windows. The surface treatment involves covering the pad area with an OSP organic protective film solder, an immersion gold layer, an immersion tin layer, or a tin spray layer. The waste liquid and waste residue after the surface treatment are purified and recycled for reuse.

9. The method for manufacturing a metal-based circuit board according to claim 1, characterized in that: The metal substrate is made of aluminum, copper, or iron, and its thickness is 1.0mm-3.0mm; The aluminum foil is an electrolytic copper foil or a rolled copper foil, with a thickness of 18μm-70μm.

10. A metal-based circuit board, prepared by the method according to any one of claims 1-9, characterized in that: It includes a conductive copper foil layer, an insulating and thermally conductive layer, and a metal base layer stacked from top to bottom. The insulating and thermally conductive layer is closely attached to the conductive copper foil layer and the metal base layer to achieve electrical insulation and heat transfer.

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