A car audio amplifier based on graphene high-conductivity material and manufacturing method thereof

Abstract

The application relates to the technical field of automobile electronic power devices, and particularly discloses an automobile audio amplifier based on a graphene high-conductivity material and a manufacturing method, the automobile audio amplifier comprising a power amplification module, a signal transmission module, a heat dissipation module and a shell, wherein the power tube in the power amplification module and the substrate conductive layer on the heat dissipation module and the shell all adopt a graphene-based composite conductor material; the graphene-based composite conductor is composed of the following components in percentage by weight: graphene powder 0.8-2.5%, copper powder 82-92%, silver powder 4-9%, nickel powder 0.5-1.2% and rare earth element dopant 0.3-1.0%. Through the synergistic optimization of graphene and metal components, the conductivity of the conductor material is improved by more than 25%, the heat conductivity is improved by more than 45%, and the density is reduced by 32%, so that the power conversion efficiency of the automobile audio amplifier is remarkably improved, the thermal drift is inhibited, the light-weight design is realized, the automobile complex installation environment is adapted, the manufacturing process is compatible with the existing production line, and the application is suitable for large-scale application.

Description

Technical Field

[0001] This invention relates to the field of automotive electronic power device technology, and in particular to an automotive audio amplifier based on graphene high conductivity material and its manufacturing method. Background Technology

[0002] The car audio amplifier is the core power component of a car audio system. Its function is to amplify audio signals to the power level needed to drive the speakers. Its performance directly determines the sound quality, power output, and operational stability of the audio system. Currently, key conductive components in car audio amplifiers (such as power transistor pins, signal transmission lines, and conductive layers on the heat sink) are mainly made of pure copper, copper alloys, or pure silver. While this meets basic usage requirements, it has significant drawbacks under the high power, confined space, and complex operating conditions (such as high temperature, vibration, and humidity changes) of a car: 1. Low power conversion efficiency: Pure copper has a conductivity of approximately 5.96 × 10⁻⁶. 7 1. Significant signal loss during transmission, especially at high power output (50-150W), leading to severe conductor heating and reducing amplifier power conversion efficiency to only 85%-90%, resulting in significant energy waste. 2. Severe thermal drift: Car audio amplifiers operate in a confined space for extended periods. Traditional conductor materials have limited thermal conductivity (pure copper has a thermal conductivity of 398W / (m・K)), causing heat accumulation that can lead to increased power tube temperature, resulting in circuit parameter drift, audio signal distortion, and unstable gain. 3. Insufficient lightweight design: Pure copper has a density of 8.96g / cm³, and silver has a density of 10.5g / cm³, resulting in a large overall amplifier weight (typical products weigh ≥500g), which is detrimental to lightweight automotive design and increases the load on the installation area. 4. Poor stability: Traditional conductors are prone to loosening of solder joints under automotive vibration and oxidation under long-term high temperature and humidity conditions, leading to increased contact resistance and shortened amplifier lifespan.

[0003] Graphene, as a two-dimensional nanomaterial, possesses ultra-high electrical conductivity (theoretical value 1.0 × 10⁻⁶). 8With high conductivity (above S / m), excellent thermal conductivity (theoretical value 5300W / (m・K)), and low density (2.2g / cm³), graphene has significant application value in the field of power electronic devices. However, there is currently no technical solution for the targeted application of graphene-based composite conductors in key components of automotive audio amplifiers. The core bottlenecks are: first, the poor interfacial compatibility between graphene and the metal matrix, leading to easy agglomeration when directly mixed, resulting in inconsistent electrical and thermal conductivity; second, automotive audio amplifiers have stringent requirements for the mechanical strength, solder compatibility, and vibration resistance of conductors, making it difficult for existing graphene composite conductors to adapt to the assembly and operating conditions of amplifiers; and third, the lack of differentiated molding processes for different amplifier components (pins, circuits, conductive layers), making it impossible to balance performance and production efficiency. Therefore, developing a graphene high-conductivity material and application solution that is suitable for the operating conditions of automotive audio amplifiers and offers balanced performance is key to solving the current technical pain points. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an automotive audio amplifier based on graphene high conductivity material and its manufacturing method, in order to solve the problems of low power conversion efficiency, serious thermal drift, short service life and limited adaptability of existing automotive audio amplifiers due to insufficient thermal conductivity, poor heat dissipation performance and high density of heat dissipation insulation material.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] A car audio amplifier based on graphene high-conductivity material includes a power amplification module, a heat dissipation module, and a housing. The power transistor in the power amplification module, as well as the substrate conductive layer on the heat dissipation module and the housing, are all made of graphene-based composite conductor material. The graphene-based composite conductor material is composed of the following components by weight percentage: 0.8-2.5% graphene powder, 82-92% copper powder, 4-9% silver powder, 0.5-1.2% nickel powder, and 0.3-1.0% rare earth element dopant. The rare earth element dopant is at least one of lanthanum, cerium, and yttrium.

[0007] Preferably, the graphene powder is single-layer or few-layer graphene with a sheet diameter of 8-25 μm, a thickness of 0.34-1.2 nm, and a purity of ≥99.6%.

[0008] Preferably, the pins of the power transistor are graphene-based composite conductor wires with a diameter of 0.2-0.5 mm, a tensile strength ≥380 MPa, and a silver layer with a thickness of 0.8-1.5 μm.

[0009] Preferably, the signal transmission line of the power amplifier module is a graphene-based composite conductor film with a thickness of 10-30 μm, a linewidth of 0.8-2.0 mm, and a sheet resistance ≤5 mΩ / sq.

[0010] Preferably, the heat dissipation module is provided with a conductive layer, which is a graphene-based composite conductor coating with a thickness of 50-100μm. The bonding strength between the conductive layer and the heat dissipation module is ≥25MPa. The heat dissipation module is made of aluminum nitride ceramic or aluminum alloy.

[0011] To address the aforementioned technical problems, the present invention also provides a method for manufacturing an automotive audio amplifier, comprising the following steps:

[0012] Step 1: Fabrication of graphene-based composite conductor material: Weigh graphene powder, copper powder, silver powder, nickel powder, and rare earth element dopants according to weight percentage, place them in a high-energy ball mill, and ball mill for 3-5 hours under argon protection at a speed of 400-600 r / min to obtain a uniformly mixed powder; select the molding process for different components:

[0013] Step 2: Fabrication of power transistor substrate: The mixed powder is placed into a metal mold, sintered by hot pressing, cooled and drawn into wire to the target diameter, annealed, and the surface is silver-plated.

[0014] Step 3: Fabrication of the thermal conductive layer of the heat dissipation substrate: The mixed powder is coated onto the substrate surface using a plasma spraying process with a spraying power of 30-40kW and a spraying distance of 80-120mm to form a conductive coating.

[0015] Step 4: Assembly and Debugging: Assemble each module into the housing, and conduct power conversion efficiency tests, thermal stability tests, and environmental resistance tests. After passing the tests, the finished product is obtained.

[0016] Preferably, in step one, the copper powder has a particle size of 8-25 μm, the silver powder has a particle size of 2-6 μm, and the nickel powder has a particle size of 5-12 μm.

[0017] Preferably, in step two, the hot pressing sintering temperature is 950-1100℃, the pressure is 40-60MPa, and the holding time is 1.5-2.5h; the annealing temperature is 450-550℃, and the holding time is 40-80min.

[0018] Preferably, in step four, the thermal stability test conditions are: ambient temperature -40℃ to 95℃, output power 50-150W, continuous test for 48h, amplifier gain drift ≤ ±0.05dB; the vibration resistance test conditions are: frequency 10-2000Hz, acceleration 20g, test for 2h in each of the three axes, with no structural loosening or performance degradation.

[0019] By adopting the above technical solution, the present invention provides an automotive audio amplifier and its manufacturing method based on graphene high-conductivity material, which has the following beneficial effects: By optimizing the formulation design of graphene-based composite conductors, differentiating molding processes, and adapting component structures, the power conversion efficiency, thermal stability, lightweighting, and reliability of the amplifier are synergistically improved; through the synergistic optimization of graphene and metal components, the conductivity of the conductor material is increased by more than 25%, the thermal conductivity is increased by more than 45%, and the density is reduced by 32%, significantly improving the power conversion efficiency of the automotive audio amplifier, suppressing thermal drift, and achieving lightweight design, adapting to the complex installation environment of automobiles, and the manufacturing process is compatible with existing production lines, making it suitable for large-scale applications. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the manufacturing method of the car audio amplifier of the present invention.

[0021] In the diagram, 1 represents step one, 2 represents step two, 3 represents step three, and 4 represents step four. Detailed Implementation

[0022] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] This invention discloses an automotive audio amplifier based on graphene high-conductivity material, comprising a power amplification module, a heat dissipation module, and a housing. The power transistor in the power amplification module, as well as the substrate conductive layer on the heat dissipation module and the housing, are all made of graphene-based composite conductor material. The graphene-based composite conductor material is composed of the following components by weight percentage: 0.8-2.5% graphene powder, 82-92% copper powder, 4-9% silver powder, 0.5-1.2% nickel powder, and 0.3-1.0% rare earth element dopant; the rare earth element dopant is at least one of lanthanum, cerium, and yttrium.

[0026] Specifically, this invention employs a composite system of graphene with copper, silver, nickel, and rare earth elements. The component ratios are designed specifically for the operating characteristics of automotive audio amplifiers, and the functions of each component are as follows: Graphene: The core functional phase, utilizing its ultra-high electrical and thermal conductivity to significantly reduce conductor loss and improve heat dissipation efficiency; Copper powder: The main conductive phase, ensuring the basic conductivity of the conductor and good processability, reducing production costs; Silver powder: An auxiliary conductive phase, further reducing conductor contact resistance and welding resistance, improving signal transmission stability; Nickel powder: An interface-enhancing phase, improving the interfacial bonding between graphene and the copper / silver matrix, inhibiting graphene agglomeration, and simultaneously improving the mechanical strength and corrosion resistance of the conductor; Rare earth element dopants: Microstructure-optimizing phases, refining conductor grains, reducing lattice defects, improving electrical and thermal conductivity, and enhancing high and low temperature stability.

[0027] Specifically, the key component structure adaptation of the automotive audio amplifier in this invention involves the targeted application of graphene-based composite conductors to the core conductive components of the amplifier, achieving a match between function and structure: Power transistor pins: High-mechanical-strength composite conductor wires with a diameter of 0.2-0.5mm and silver-plated surface treatment are used to balance conductivity and welding reliability, adapting to the current transmission requirements of high-power transistors; Signal transmission lines: Thin-film composite conductor lines with a thickness of 10-30μm are used to reduce the space occupied by the lines, reduce parasitic parameters, and improve the fidelity of audio signal transmission; Conductive layer of heat dissipation substrate: A high thermal conductivity composite conductor coating is used, directly coated on the surface of the heat dissipation substrate to form an "integrated conductivity-heat dissipation" structure, which quickly dissipates the heat generated by the power transistor and suppresses temperature rise.

[0028] Specifically, such as Figure 1As shown in the flowchart of the manufacturing method of the automotive audio amplifier in this invention, the invention designs exclusive molding processes for different components based on their structural characteristics to ensure a balance between performance and production efficiency: Power transistor pins: The "hot pressing sintering-wire drawing-annealing-silver plating" process is adopted to ensure the density and flexibility of the conductor wires and meet the assembly and bending requirements of the pins; Signal transmission lines: The "slurry preparation-screen printing-sintering" process is adopted, which is suitable for mass production of thin film circuits and has a firm bond with the PCB substrate; Conductive layer of heat dissipation substrate: The plasma spraying process is adopted to quickly form a conductive coating with high bonding strength, which is compatible with the surface characteristics of ceramic / metal substrates.

[0029] Specifically, in Embodiment 1 of the present invention, the graphene-based composite conductor formulation (by weight percentage) is as follows: 1.2% graphene powder (sheet diameter 8-15 μm, thickness 0.34-0.8 nm, purity 99.7%), 88% copper powder (particle size 8-20 μm), 6% silver powder (particle size 2-4 μm), 0.8% nickel powder (particle size 5-9 μm), and 0.5% lanthanum dopant;

[0030] The production process is as follows:

[0031] (1) Fabrication of composite conductor materials:

[0032] a. Weigh each component according to the formula, put them into a high-energy ball mill, and ball mill for 4 hours under argon protection at a speed of 500 r / min to obtain a mixed powder;

[0033] b. Fabrication of power transistor leads: Mixed powder is placed in a mold, hot-pressed and sintered (temperature 1000℃, pressure 50MPa, heat preservation for 2h), after cooling, drawn into wires with a diameter of 0.3mm, annealed at 480℃ for 60min, and the surface is silver-plated (thickness 1.0μm).

[0034] c. Fabrication of signal transmission lines: Mix the powder with epoxy resin binder (weight ratio 9:1) to form a slurry, screen print it onto a PCB substrate, dry at 130℃ for 1.5h, and sinter at 900℃ for 45min to form a line with a thickness of 20μm and a line width of 1.2mm;

[0035] d. Fabrication of conductive layer on heat dissipation substrate: Using plasma spraying process, mixed powder is coated onto the surface of aluminum nitride ceramic substrate (spraying power 35kW, distance 100mm) to form a conductive coating with a thickness of 80μm;

[0036] (2) Assemble the power amplifier module: solder the power transistor to the composite conductor pin, assemble it on the heat dissipation substrate, and apply thermal grease (thermal conductivity 3.2W / (m・K)).

[0037] (3) Assemble the signal transmission module: Solder the signal lines to the input / output terminals of the power transistors and fix them with polyimide tape for insulation;

[0038] (4) Assembly and debugging: assembled in an aluminum alloy housing, test results: power conversion efficiency is 96%.

[0039] It is understandable that this invention is rationally designed, uniquely constructed, and has the following advantages:

[0040] 1. Significantly improved power conversion efficiency: The conductivity of the graphene-based composite conductor reaches 7.5 × 10⁻⁶. 7 -9.2×10 7 The S / m is improved by 25%-54% compared to pure copper, the signal transmission loss is reduced by more than 35%, the amplifier power conversion efficiency is ≥95%, and the energy consumption is reduced by 8%-12% at an output power of 50-150W.

[0041] 2. Significantly improved thermal stability: The thermal conductivity of the composite conductor reaches 580-650W / (m・K), which is 45%-63% higher than that of pure copper. The operating temperature of the power tube is reduced to below 85℃, the thermal drift is ≤±0.05dB, the audio signal distortion is ≤0.3%, and the sound quality stability is significantly improved.

[0042] 3. Outstanding lightweight effect: The density of the composite conductor is 6.0-6.6g / cm³, which is 30%-33% lower than that of pure copper. The overall weight of the amplifier is reduced by 35%-40% (finished product weight ≤300g), which meets the lightweight design requirements of automobiles and reduces the installation load.

[0043] 4. Significantly enhanced reliability: The addition of nickel powder and rare earth elements increases the conductor's tensile strength to ≥380MPa and the weld bond strength to ≥25MPa. It maintains stable performance in a temperature range of -40℃ to 95℃ and a vibration environment of 10-2000Hz, extending its service life to 8-12 years (compared to 3-5 years for existing products).

[0044] 5. Strong industrial compatibility: The manufacturing process is compatible with existing electronic device production lines, requiring no special equipment modifications. The cost of composite conductor materials is more than 60% lower than that of pure silver, making it suitable for large-scale mass production.

[0045] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A car audio amplifier based on graphene high-conductivity material, comprising a power amplification module, a heat dissipation module, and a housing, characterized in that: The power transistors in the power amplifier module, as well as the conductive layer of the substrate on the heat dissipation module and the housing, are all made of graphene-based composite conductor material. The graphene-based composite conductor material is composed of the following components by weight percentage: 0.8-2.5% graphene powder, 82-92% copper powder, 4-9% silver powder, 0.5-1.2% nickel powder, and 0.3-1.0% rare earth element dopant. The rare earth element dopant is at least one of lanthanum, cerium, and yttrium.

2. The automotive audio amplifier based on graphene high-conductivity material according to claim 1, characterized in that: The graphene powder is a single-layer or few-layer graphene with a sheet diameter of 8-25 μm, a thickness of 0.34-1.2 nm, and a purity of ≥99.6%.

3. The automotive audio amplifier based on graphene high-conductivity material and its manufacturing method according to claim 1, characterized in that: The power transistor's pins are graphene-based composite conductor wires with a diameter of 0.2-0.5 mm, a tensile strength ≥380 MPa, and a silver layer with a thickness of 0.8-1.5 μm.

4. The automotive audio amplifier based on graphene high-conductivity material according to claim 1, characterized in that: The signal transmission line of the power amplifier module is a graphene-based composite conductor film with a thickness of 10-30 μm, a linewidth of 0.8-2.0 mm, and a sheet resistance ≤5 mΩ / sq.

5. The automotive audio amplifier based on graphene high-conductivity material according to claim 1, characterized in that: The heat dissipation module is provided with a conductive layer, which is a graphene-based composite conductor coating with a thickness of 50-100μm. The bonding strength between the conductive layer and the heat dissipation module is ≥25MPa. The heat dissipation module is made of aluminum nitride ceramic or aluminum alloy.

6. A method for manufacturing an automotive audio amplifier as described in any one of claims 1-5, characterized in that: Includes the following steps: Step 1: Fabrication of graphene-based composite conductor material: Weigh graphene powder, copper powder, silver powder, nickel powder, and rare earth element dopants according to weight percentage, place them in a high-energy ball mill, and ball mill for 3-5 hours under argon protection at a speed of 400-600 r / min to obtain a uniformly mixed powder; select the molding process for different components: Step 2: Fabrication of power transistor substrate: The mixed powder is placed into a metal mold, sintered by hot pressing, cooled and drawn into wire to the target diameter, annealed, and the surface is silver-plated. Step 3: Fabrication of the thermal conductive layer of the heat dissipation substrate: The mixed powder is coated onto the substrate surface using a plasma spraying process with a spraying power of 30-40kW and a spraying distance of 80-120mm to form a conductive coating. Step 4: Assembly and Debugging: Assemble each module into the housing, and conduct power conversion efficiency tests, thermal stability tests, and environmental resistance tests. After passing the tests, the finished product is obtained.

7. The method for manufacturing an automotive audio amplifier according to claim 6, characterized in that: In step one, the copper powder has a particle size of 8-25 μm, the silver powder has a particle size of 2-6 μm, and the nickel powder has a particle size of 5-12 μm.

8. The method for manufacturing an automotive audio amplifier according to claim 6, characterized in that: In step two, the hot pressing sintering temperature is 950-1100℃, the pressure is 40-60MPa, and the holding time is 1.5-2.5h; the annealing temperature is 450-550℃, and the holding time is 40-80min.

9. The method for manufacturing an automotive audio amplifier according to claim 6, characterized in that: In step four, the thermal stability test conditions are: ambient temperature -40℃ to 95℃, output power 50-150W, continuous test for 48h, amplifier gain drift ≤ ±0.05dB; the vibration resistance test conditions are: frequency 10-2000Hz, acceleration 20g, test for 2h in each of the three axes, with no structural loosening or performance degradation.

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