Method for preparing ultrathin diamond acoustic vibrating diaphragm

Abstract

The invention discloses a method for preparing an ultrathin diamond acoustic vibrating diaphragm, and belongs to the field of diamond application. Comprising the following steps: S1, processing a substrate material to form a three-dimensional shape required by the acoustic diaphragm; s2, depositing a diamond film on the substrate material; s3, stripping the diamond film from the substrate material; and S4, the stripped diamond material is adsorbed on a prefabricated carrier through static electricity to form the diamond acoustic vibrating diaphragm. Compared with the prior art, the method has the beneficial effects that the diamond film in the three-dimensional shape is prepared in a chemical vapor deposition mode, then the diamond film is manufactured into the acoustic vibrating diaphragm, the whole process is simple, low-cost manufacturing of the diamond acoustic vibrating diaphragm can be achieved, and the method is suitable for large-scale popularization and application. Therefore, the diamond material can be conveniently popularized and applied to the acoustic diaphragm.

Description

Technical Field

[0001] The invention belongs to the field of diamond film applications, and in particular relates to a method for preparing an ultra-thin diamond acoustic diaphragm. Background Art

[0002] Diamond is a superhard material with a Mohs hardness of 10 and a Vickers hardness of 10,000 kg / mm. 2 Comparing the Knoop hardness values, it can be concluded that diamond is 5 times harder than alumina, 12 times harder than quartz, 4.7 times harder than tungsten carbide, 4 times harder than silicon carbide, 3.7 times harder than boron carbide, and 2 times harder than cubic boron nitride. It is the hardest material known to date in natural materials. In addition, the bulk elastic modulus of diamond is K = 5.42×10 5 N / mm 2 , 1.8 times that of metallic tungsten and 5-7 times that of various types of stainless steel. Comparing the compressive and tensile strengths of diamond with several other hard materials reveals that diamond has strong compressive resistance but low tensile strength, resulting in its often hard and brittle nature. These properties lend diamond a wide range of applications in machining, extending from traditional machining to precision machining and semiconductor processing.

[0003] Diamond, due to its ultra-high elastic modulus and relatively low density, has a sound wave velocity far exceeding that of conventional materials, making it ideally suited for acoustic components. However, due to its high cost and difficulty in production, it is currently used only in limited quantities in very high-end audiophile audio equipment. Furthermore, diamond, when thicker than 200 microns, lacks flexibility and is prone to cracking and damage during acoustic component fabrication, making its processing extremely challenging.

[0004] An acoustic diaphragm is a thin film component used to convert electrical signals into sound signals and is widely used in acoustic devices such as speakers, headphones, and microphones. Currently, for cost and performance reasons, acoustic diaphragms on the market use graphene or composite materials for high-fidelity audio; polypropylene or bio-diaphragms for everyday headphones; and metal or Kevlar for professional monitoring equipment. Overall, although diamond is well-suited for acoustic diaphragm production, the lack of suitable manufacturing processes has prevented widespread adoption. Summary of the Invention

[0005] To solve the above problems, the purpose of the present invention is to provide a method for preparing an ultra-thin diamond acoustic diaphragm, which can realize the production of the diamond acoustic diaphragm at low cost and facilitate the promotion and application of diamond materials in acoustic diaphragms.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] The present invention provides a method for preparing an ultra-thin diamond acoustic diaphragm, comprising the following steps:

[0008] S1: Process the base material to form the three-dimensional shape required by the acoustic diaphragm;

[0009] S2: depositing a diamond film on a substrate material;

[0010] S3: peeling the diamond film from the substrate material;

[0011] S4: The peeled diamond material is electrostatically adsorbed on a prefabricated carrier to form a diamond acoustic diaphragm.

[0012] Furthermore, in step S1, the base material is made of a high thermal conductivity material.

[0013] Furthermore, the high thermal conductivity material includes but is not limited to silicon, silicon carbide, metallic molybdenum, and metallic tungsten.

[0014] Furthermore, in step S1, the processing method is one of mechanical processing, laser processing, ultrasonic processing, and electric discharge processing.

[0015] Furthermore, in step S1, the three-dimensional shape includes a plane, an inwardly concave arc surface, and an outwardly convex arc surface. The acoustic diaphragm with a plane shape has the advantages of flat frequency response and low distortion, and is often used in flat speakers and some high-end headphones; the acoustic diaphragm with an inwardly concave arc surface or an outwardly convex arc surface has the advantages of good transient response, strong directivity, and low distortion, and is used in mid-high frequency units, such as high-fidelity audio systems.

[0016] Furthermore, in step S2, a diamond film is deposited in the MPCVD chamber, and the thickness of the diamond film is 0.1-50 um.

[0017] Furthermore, in step S2, the deposition conditions of the diamond film are: deposition power 4-10kW, deposition pressure 50-300Torr, carrier gas is hydrogen, hydrogen flow rate is 100-2000sccm, carbon source is methane, methane accounts for 2%-12%, auxiliary gas is nitrogen, borane, nitrogen or borane accounts for 1-100ppm.

[0018] Furthermore, in step S3, the ultra-thin diamond film is peeled off from the base material by using a tape stripping method or a chemical etching method.

[0019] Furthermore, the tape stripping method comprises: using tape to bond and peel the ultra-thin diamond film from the base material, and then separating the diamond film and the tape by heating or UV light irradiation.

[0020] Furthermore, the viscosity of the adhesive tape is not less than 3 N / cm, and the viscosity angle is between 40-70°.

[0021] Furthermore, the heating method is to uniformly heat the material using a hot air gun, a heating plate or an oven to a specific temperature (90-180° C.).

[0022] Furthermore, the chemical etching method is: using HF to perform chemical etching to dissolve the base material, so that the ultra-thin diamond film is separated from the base material.

[0023] Furthermore, in step S4, the electrostatic adsorption method is: using a flexible electrode array module, applying a voltage (200V) between the flexible electrode and the target film, adsorbing the film by Coulomb force or dielectrophoretic force, and placing the diamond film peeled from the substrate on a prefabricated carrier.

[0024] The beneficial effects of the present invention are: compared with the existing technology, the present application prepares a three-dimensional diamond film by chemical vapor deposition, and then makes the diamond film into an acoustic diaphragm. The entire process is simple and can achieve low-cost production of diamond acoustic diaphragms, thereby facilitating the promotion and application of diamond materials in acoustic diaphragms. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart of Example 1.

[0026] Figure 2 It is a process flow chart of Example 2.

[0027] Figure 3 This is a process flow chart of Example 3.

[0028] Figure 4 It is a schematic diagram of the structure of a flat diamond acoustic diaphragm.

[0029] Figure 5 It is a schematic diagram of the structure of a diamond acoustic diaphragm with a concave arc surface.

[0030] Figure 6 It is a schematic diagram of the structure of a diamond acoustic diaphragm with a convex arc surface. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] To achieve the above object, the technical solution of the present invention is as follows:

[0033] Example 1:

[0034] like Figure 1As shown, this embodiment provides a method for preparing an ultra-thin diamond acoustic diaphragm, comprising the following steps:

[0035] S11: Processing the silicon substrate to form the concave arc shape required by the acoustic diaphragm;

[0036] S12: Place the MPCVD chamber on the silicon substrate and deposit a diamond film with a thickness of 0.1 μm;

[0037] S13: using HF to chemically etch and peel the diamond film from the substrate;

[0038] S14: The peeled diamond material is electrostatically adsorbed on a prefabricated carrier to form a diamond acoustic diaphragm.

[0039] Furthermore, in step S11, the processing method is one of mechanical processing, laser processing, ultrasonic processing, and electric discharge processing.

[0040] Further, in step S11, see Figure 5 The acoustic diaphragm with a concave arc surface has the advantages of good transient response, strong directivity and low distortion, and is used in mid-high frequency units, such as high-fidelity audio systems.

[0041] Furthermore, in step S12, the deposition conditions of the diamond film are: deposition power 4kW, deposition pressure 50Torr, carrier gas is hydrogen, hydrogen flow rate 300sccm, carbon source is methane, methane accounts for 3%, auxiliary gas is nitrogen, nitrogen or borane accounts for 1ppm.

[0042] Furthermore, in step S14, the electrostatic adsorption method is: using a flexible electrode array module, applying a voltage of 200V between the flexible electrode and the target film, adsorbing the film by Coulomb force or dielectrophoretic force, and placing the diamond film peeled from the substrate on a prefabricated carrier.

[0043] Example 2:

[0044] like Figure 2 As shown, this embodiment provides a method for preparing an ultra-thin diamond acoustic diaphragm, comprising the following steps:

[0045] S21: Processing the metal molybdenum substrate to form the convex arc shape required by the acoustic diaphragm;

[0046] S22: After applying a release agent on the surface of the metal molybdenum substrate, it is placed in the MPCVD chamber to deposit a diamond film with a thickness of 0.1 μm;

[0047] S23: peeling the diamond film from the substrate material using a thermal tape;

[0048] S24: The peeled diamond material is electrostatically adsorbed on a prefabricated carrier to form a diamond acoustic diaphragm.

[0049] Furthermore, in step S21, the processing method is one of mechanical processing, laser processing, ultrasonic processing, and electric discharge processing.

[0050] Further, in step S21, see Figure 6 The acoustic diaphragm with a convex arc shape has the advantages of good transient response, strong directivity and low distortion, and is used in mid-high frequency units, such as high-fidelity audio systems.

[0051] Furthermore, in step S22, the deposition conditions of the diamond film are: deposition power 5.5 kW, deposition pressure 100 Torr, carrier gas is hydrogen, hydrogen flow rate 500 sccm, carbon source is methane, methane accounts for 5%, auxiliary gas is nitrogen, nitrogen or borane accounts for 1 ppm.

[0052] Furthermore, in step S23, the viscosity of the thermal tape is not less than 3N / cm, and the viscosity angle is between 40-70°. After passing through the thermal tape glass, the thermal tape is heated to 90-180°C by a hot air gun, a heating plate or an oven, so that the diamond film and the thermal tape are separated.

[0053] Furthermore, in step S24, the electrostatic adsorption method is: using a flexible electrode array module, applying a voltage of 200V between the flexible electrode and the target film, adsorbing the film by Coulomb force or dielectrophoretic force, and placing the diamond film peeled from the substrate on a prefabricated carrier.

[0054] Example 3:

[0055] like Figure 3 As shown, this embodiment provides a method for preparing an ultra-thin diamond acoustic diaphragm, comprising the following steps:

[0056] S31: Processing the metal tungsten substrate to form the plane shape required by the acoustic diaphragm;

[0057] S32: After applying a release agent on the surface of the metal tungsten substrate, it is placed in the MPCVD chamber to deposit a diamond film with a thickness of 0.1 μm;

[0058] S33: peeling the diamond film from the substrate material using a photosensitive tape;

[0059] S34: The peeled diamond material is electrostatically adsorbed on a prefabricated carrier to form a diamond acoustic diaphragm.

[0060] Furthermore, in step S31 , the processing method is one of mechanical processing, laser processing, ultrasonic processing, and electrical discharge processing.

[0061] Further, in step S31, see Figure 4 The flat-shaped acoustic diaphragm has the advantages of flat frequency response and low distortion, and is often used in planar speakers and some high-end headphones.

[0062] Furthermore, in step S32, the deposition conditions of the diamond film are: deposition power 9.5 kW, deposition pressure 120 Torr, carrier gas is hydrogen, hydrogen flow rate 500 sccm, carbon source is methane, methane accounts for 8%, auxiliary gas is nitrogen, nitrogen or borane accounts for 1 ppm.

[0063] Furthermore, in step S34, the electrostatic adsorption method is: using a flexible electrode array module, applying a voltage of 200V between the flexible electrode and the target film, adsorbing the film by Coulomb force or dielectrophoretic force, and placing the diamond film peeled from the substrate on a prefabricated carrier.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing an ultra-thin diamond acoustic diaphragm, characterized in that: The following steps are involved: S1: Process the base material to form the three-dimensional shape required by the acoustic diaphragm; S2: depositing a diamond film on a substrate material; S3: peeling the diamond film from the substrate material; S4: The peeled diamond material is electrostatically adsorbed on a prefabricated carrier to form a diamond acoustic diaphragm.

2. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 1, wherein: In step S1 , the base material is made of a high thermal conductivity material.

3. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 1, wherein: In step S1 , the processing method is one of mechanical processing, laser processing, ultrasonic processing, and electrical discharge processing.

4. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 1, wherein: In step S1 , the three-dimensional shape includes a plane, an inner concave arc surface, and an outer convex arc surface.

5. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 1, wherein: In step S2, a diamond film is deposited in the MPCVD chamber, and the thickness of the diamond film is 0.1-50um; the deposition conditions of the diamond film are: deposition power 4-10kW, deposition pressure 50-300Torr, carrier gas is hydrogen, hydrogen flow rate 100-2000sccm, carbon source is methane, methane accounts for 2%-12%, auxiliary gas is nitrogen, borane, nitrogen or borane accounts for 1-100ppm.

6. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 1, wherein: In step S3, the ultra-thin diamond film is peeled off from the base material by using a tape stripping method or a chemical etching method.

7. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 6, wherein: The tape stripping method comprises the following steps: using tape to bond and peel the ultra-thin diamond film from the base material, and then separating the diamond film and the tape by heating or UV light irradiation.

8. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 7, wherein: The viscosity of the adhesive tape is not less than 3N / cm, and the viscosity angle is between 40-70°.

9. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 6, wherein: The chemical etching method comprises the following steps: using HF to perform chemical etching to dissolve the base material, thereby causing the ultra-thin diamond film to be bonded and separated from the base material.

10. The method for preparing an ultra-thin diamond acoustic diaphragm according to claim 1, wherein: In step S4, the electrostatic adsorption method is: using a flexible electrode array module, applying voltage between the flexible electrode and the target film, adsorbing the film through Coulomb force or dielectrophoretic force, and placing the diamond film peeled from the substrate on a prefabricated carrier.

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