Loudspeaker diaphragm

Abstract

The utility model discloses a loudspeaker diaphragm, and relates to the field of acoustics. The loudspeaker diaphragm comprises a base material, a metal bottom layer, a transition layer and a TAC composite film layer. The metal bottom layer is arranged on the surface of one side or two sides of the base material, the material of the metal bottom layer is Cr, Ti or Ni, and the thickness of the metal bottom layer is 0.05-0.3 mu m; the transition layer is arranged on the surface of the metal bottom layer, the material of the transition layer is carbide of the material of the metal bottom layer, and the thickness of the transition layer is 0.1-0.3 mu m; and the TAC composite film layer is arranged on the surface of the transition layer and comprises hard TAC film layers and soft DLC film layers which are alternately overlapped. By arranging the transition layer for connecting the metal bottom layer and the TAC composite film layer, the binding force between the base material and the TAC composite film layer is improved, further, the thickness setting of the metal bottom layer and the transition layer is beneficial to ensuring the dimensional precision of the thickness of the metal bottom layer and / or the transition layer formed by equipment, and the product quality is improved. Meanwhile, the weight of the loudspeaker diaphragm is not increased and the tone quality is not influenced because the transition layer is too thick.

Description

[0001] Priority information: This application claims priority to Chinese patent application No. 2024201402966, filed on January 19, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The utility model relates to the field of acoustics, in particular to a loudspeaker diaphragm. Background Art

[0003] From the perspective of acoustics, specifically steady-state vibration, there are three requirements for the physical properties of a speaker diaphragm material: 1. To maximize the playback bandwidth, the diaphragm material must have a high specific elastic modulus. 2. To prevent sound distortion and suppress the diaphragm's splitting vibrations during operation, the diaphragm material must have high flexural rigidity. 3. To further improve the speaker's sound quality and smooth the diaphragm's frequency response curve, the diaphragm material must have appropriate internal damping. Furthermore, to ensure long-term stable operation, the diaphragm material must also exhibit good moisture and mildew resistance.

[0004] Tetrahedral amorphous carbon films (TAC) are high sp 3 The diamond-structured membrane exhibits properties similar to those of diamond. TAC diamond diaphragms possess numerous superior properties. First, they are extremely hard, with a hardness-to-weight ratio five times that of ceramic. Second, they offer a high internal conduction velocity of 18,000 m / sec. Third, they conduct heat exceptionally well, over five times that of the next best material, silver. Fourth, their molecular structure is extremely compact and extremely rigid. Fifth, their molecular structure is stable, resisting reactions with gases or other materials, ensuring they can last for tens of millions of years without deterioration.

[0005] The applicant's research found that the above five material characteristics are all excellent properties for the tweeter diaphragm, especially the heat conduction ability. Because the tweeter's voice coil is prone to generate high heat when high power input is applied, if the voice coil is attached to the diamond diaphragm, the high heat of the voice coil can be immediately conducted away, greatly improving the tweeter's ability to withstand power, which is absolutely unmatched by other materials.

[0006] Therefore, TAC membrane is an ideal high-frequency diaphragm material. TAC membrane speaker diaphragms give speakers high-fidelity performance: for example, they can increase the upper frequency response limit, improve transient response and harmonic distortion characteristics, and make the sound range wide, the sound quality mellow, and the treble crisp and bright.

[0007] The applicant's research found that depositing a TAC film layer on the speaker diaphragm substrate is a simple and effective way to improve the performance of the speaker diaphragm. For the speaker diaphragm, the thicker the TAC film layer is, the better. In this way, the elastic modulus, rigidity and internal damping of the speaker diaphragm will be greater, and the sound quality of the sound produced will be better.

[0008] However, related technologies often use a single arc technology, magnetron sputtering technology, or ion beam assisted deposition technology to prepare the diaphragm coating. During the preparation process of a single process, once the thickness of the entire TAC film layer increases, the stress in the entire TAC film layer will increase, which will affect the bonding strength between the TAC film layer and the diaphragm substrate, causing the TAC film layer to easily peel off the diaphragm substrate, affecting the service life and efficiency of the speaker diaphragm. The contradiction between the thickness of the TAC film layer and the bonding strength of the diaphragm has become a problem that needs to be solved urgently.

[0009] Therefore, it is necessary to improve the prior art to overcome the above defects. Utility Model Content

[0010] The purpose of the utility model is to provide a loudspeaker diaphragm, which can improve the bonding strength between the TAC film layer and the substrate.

[0011] To achieve the above-mentioned purpose of the utility model, the utility model proposes a loudspeaker diaphragm, comprising:

[0012] substrate;

[0013] A metal base layer is provided on the surface of one side or both sides of the substrate, wherein the material of the metal base layer is Cr, Ti or Ni, and the thickness of the metal base layer is 0.05 to 0.3 μm;

[0014] a transition layer provided on the surface of the metal base layer, wherein the material of the transition layer is a carbide of the material of the metal base layer, and the thickness of the transition layer is 0.1 to 0.3 μm; and

[0015] The TAC composite film layer is arranged on the surface of the transition layer, and comprises a hard TAC film layer and a soft DLC film layer which are alternately stacked.

[0016] Furthermore, the transition layer has a thickness of 0.15 to 0.25 μm.

[0017] Furthermore, the thickness of the metal bottom layer is 0.1-0.2 μm.

[0018] Furthermore, the thickness of the hard TAC film layer is greater than the thickness of the soft DLC film layer.

[0019] Furthermore, the thickness of the hard TAC film layer is 0.1-0.3 μm, and the thickness of the soft DLC film layer is 0.05-0.1 μm.

[0020] Furthermore, the total number of layers of the hard TAC film layer and the soft DLC film layer is 10 to 300 layers.

[0021] Furthermore, the total number of layers of the hard TAC film layer and the soft DLC film layer is 20 to 100 layers.

[0022] Furthermore, the thickness of the TAC composite film layer is 2 to 20 μm.

[0023] Furthermore, the film layer connected to the transition layer in the TAC composite film layer is a hard TAC film layer or a soft DLC film layer.

[0024] Furthermore, the material of the metal bottom layer is Cr, and the material of the transition layer is Cr3C2; or, the material of the metal bottom layer is Ti, and the material of the transition layer is TiC; or, the material of the metal bottom layer is Ni, and the material of the transition layer is Ni3C;

[0025] The substrate is made of aluminum, aluminum alloy, titanium, titanium alloy, beryllium, paper, carbon fiber or plastic.

[0026] Compared with the prior art, the present invention has the following beneficial effects: the speaker diaphragm of the present invention includes a substrate, a metal bottom layer, a transition layer and a TAC composite film layer; the metal bottom layer is arranged on the surface of one side or both sides of the substrate; the transition layer is arranged on the surface of the metal bottom layer; the TAC composite film layer is arranged on the surface of the transition layer, including hard TAC film layers and soft DLC film layers that are alternately stacked. On the one hand, the transition layer is connected between the metal bottom layer and the TAC composite film layer, and can simultaneously generate a strong bonding force with the metal bottom layer and the TAC composite film layer, thereby improving the bonding force between the TAC composite film layer and the substrate. At the same time, the transition layer can buffer the huge stress brought by the TAC composite film layer during the vibration of the diaphragm, reducing the risk of the TAC composite film layer falling off when the speaker diaphragm vibrates and makes sounds. Furthermore, the thickness of the metal bottom layer is 0.05 to 0.3 μm, and the thickness of the transition layer is 0.1 to 0.3 μm, which is conducive to ensuring the dimensional accuracy of the thickness of the metal bottom layer and the transition layer formed by the equipment. On the other hand, the weight of the speaker diaphragm will not be increased due to the excessive thickness of the metal base layer and / or the transition layer, thereby affecting the sound quality; on the other hand, by alternately superimposing the hard TAC film layer and the soft DLC film layer on the surface of the transition layer, the TAC composite film layer forms a structure in which soft and hard layers are alternately superimposed, which can improve the sound performance of the speaker; at the same time, in the structure in which soft and hard layers are alternately superimposed, the toughness of the soft DLC film layer is better than that of the hard TAC film layer, and it can produce a larger deformation when vibrating and making sound; therefore, the soft DLC film layer can reduce the stress generated by the TAC composite film layer when the diaphragm vibrates and makes sound, thereby further improving the sound performance of the speaker diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of a loudspeaker diaphragm according to an embodiment of the present invention, wherein the TAC composite film layer includes a hard TAC film layer and a soft DLC film layer.

[0028] Figure 2 It is a schematic diagram of a loudspeaker diaphragm according to an embodiment of the present invention, wherein the TAC composite film layer includes multiple hard TAC film layers and soft DLC film layers, and TAC composite film layers are provided on both sides of the substrate.

[0029] Figure 3 It is a schematic diagram of a loudspeaker diaphragm according to an embodiment of the present invention, wherein the TAC composite film layer includes multiple hard TAC film layers and soft DLC film layers, and the TAC composite film layer is provided on one side of the substrate.

[0030] Figure 4 This is a flow chart of a method for preparing a loudspeaker diaphragm according to an embodiment of the present invention.

[0031] Figure 5 This is a flow chart of forming a transition layer in one embodiment of the present invention.

[0032] Figure 6 This is a flow chart of alternately depositing a hard TAC film layer and a soft DLC film layer on the surface of a transition layer in one embodiment of the present invention.

[0033] Figure 7 This is a flow chart of alternately depositing a hard TAC film layer and a soft DLC film layer on the surface of a transition layer according to another embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0035] As used herein, the terms "comprise," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0036] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0037] like Figure 1 As shown, a loudspeaker diaphragm according to a preferred embodiment of the present invention includes a substrate 1, a metal bottom layer 2, a transition layer 3 and a TAC composite film layer 4.

[0038] The substrate 1 serves as the base material of the loudspeaker diaphragm and serves to support other membrane layers. Furthermore, the shape of the substrate 1 is not limited and a substrate 1 of a suitable shape can be selected according to the application scenario of the loudspeaker diaphragm.

[0039] The metal bottom layer 2 is disposed on the surface of the substrate 1 . The material of the metal bottom layer 2 is Cr (chromium), Ti (titanium) or Ni (nickel).

[0040] The transition layer 3 is provided on the surface of the metal base layer 2. The material of the transition layer 3 is a carbide of the material of the metal base layer 2. For example, when the material of the metal base layer 2 is Cr, the material of the transition layer 3 is chromium carbide (Cr3C2); when the material of the metal base layer 2 is Ti, the material of the transition layer 3 is titanium carbide (TiC); when the material of the metal base layer 2 is Ni, the material of the transition layer 3 is nickel carbide (Ni3C). Depositing a carbide layer of the metal base layer 2 on the metal base layer 2 helps to improve the bonding strength between the TAC composite film layer 4 and the metal base layer 2.

[0041] The TAC composite film layer 4 is arranged on the surface of the transition layer 3, the metal bottom layer 2 is tightly bonded to the substrate 1, and there is a strong metal bond bonding force between the transition layer 3 and the metal bottom layer 2. The transition layer 3 and the TAC composite film layer 4 have good compatibility and can produce a strong SP3 bond bonding force, thereby improving the stability and bonding force of the connection between the metal bottom layer 2 and the TAC composite film layer 4, and also improving the stability and bonding force of the connection between the substrate 1 and the TAC composite film layer 4; at the same time, the metal bottom layer 2 and the transition layer 3 can buffer the huge stress brought by the TAC composite film layer 4 during the vibration of the diaphragm, effectively improve the performance of the diaphragm, and effectively prevent the TAC composite film layer 4 from peeling off during the vibration of the diaphragm.

[0042] The TAC composite film layer 4 includes a hard TAC film layer 40 and a soft DLC film layer 41 which are alternately stacked. 3 The bond content is greater than the sp 3 bond content, so that the hardness of the alternately stacked film layers is different. It can be understood that the sp 3 The greater the bond content, the greater its hardness is generally, that is, the hardness of the hard TAC film layer 40 is greater than the hardness of the soft DLC film layer 41. Since the TAC film layer grows into a columnar crystal structure during the growth process, defects such as large particles will appear during the growth of the columnar crystal, resulting in greater internal stress. By staggering the soft DLC film layer and the hard TAC film layer, the longitudinal growth of the columnar crystal can be interrupted, the defects or vacancies between the grains can be reduced, and the internal stress generated by the defects of the columnar crystal itself can be reduced. In addition, the combination of the soft film layer and the hard film layer also releases the internal stress of the hard film layer. Since the soft film layer has good toughness and can produce a large deformation, when the hard film layer is deposited on it, the stress inside the hard film layer is released by combining with the soft film layer, thereby further reducing the internal stress of the entire film layer. Therefore, the setting method of the soft and hard stacked film layers allows the TAC composite film layer 4 to take into account the performance of high hardness and low stress at the same time, which is beneficial to reduce the risk of the TAC composite film layer 4 peeling off from the substrate 1 due to excessive stress and improve the bonding strength with the substrate 1.

[0043] It is understood that the TAC film layer is a type of DLC film layer, and the hardness of the hard TAC film layer 40 in this application is greater than the hardness of the soft DLC film layer 41. In some embodiments, such as the embodiments described in this application, the hard TAC film layer refers to sp 3 The DLC film with a bond content greater than or equal to 50% is a soft DLC film. 3 The DLC film layer has a bond content of less than 50%. Optionally, the sp 3 The bond content is 50% to 90%, for example, the sp 3 The bond content is 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90%; the sp of the soft DLC film layer 41 3 The sp3 bond content is 10% to 40%. For example, the sp3 bond content of the soft DLC film layer 41 is 10%, 15%, 20%, 25%, 30%, 35% or 40%.

[0044] The sp of the hard TAC film layer 40 and the soft DLC film layer 41 3 The bond content is different. By alternately stacking the hard TAC film layer 40 and the soft DLC film layer 41 on the surface of the transition layer 3, the TAC composite film layer 4 forms a structure in which soft and hard film layers are alternately stacked, which can improve the sound performance of the speaker; at the same time, in the structure in which soft and hard film layers are alternately stacked, the toughness of the soft DLC film layer 41 is better than that of the hard TAC film layer 40, and it can produce a larger deformation when vibrating and making sounds; therefore, the soft DLC film layer 41 can reduce the stress generated by the TAC composite film layer 4 when the diaphragm vibrates and makes sounds, and the alternating stacking improves the bonding force between the hard TAC film layer 40 and the soft DLC film layer 41, thereby improving the sound performance of the speaker; in addition, the transition layer 3 can buffer the stress brought by the TAC composite film layer 4 during the vibration process, thereby reducing the risk of the TAC composite film layer 4 falling off when the speaker diaphragm vibrates and makes sounds.

[0045] It is understood that the metal bottom layer 2 can be provided on one side or both sides of the substrate 1. Figure 2 In the embodiment shown, the metal bottom layer 2 is provided on the surfaces of both sides of the substrate 1, and the metal bottom layer 2, the transition layer 3 and the TAC composite film layer 4 are formed on the surfaces of both sides of the substrate 1; Figure 1 and Figure 3 In the embodiment shown, the metal base layer 2 is provided on the surface of one side of the substrate 1 , and the metal base layer 2 , the transition layer 3 and the TAC composite film layer 4 are formed on the surface of one side of the substrate 1 .

[0046] Furthermore, the thickness of the metal base layer 2 is 0.05 to 0.3 μm, for example, the thickness of the metal base layer 2 is 0.05, 0.1, 0.15, 0.2, 0.25, or 0.3 μm. Within this thickness range, the dimensional accuracy of the thickness of the metal base layer 2 formed by the equipment is ensured, while at the same time, the weight of the speaker diaphragm is not increased due to the excessive thickness of the metal base layer 2, which would affect the sound quality.

[0047] The thickness of the transition layer 3 is 0.1 to 0.3 μm. For example, the thickness of the transition layer 3 is 0.1, 0.15, 0.2, 0.25, or 0.3 μm. Within this thickness range, the transition layer 3, the metal base layer 2, and the TAC composite film layer 4 can form a relatively good bonding force, and it is helpful to ensure the dimensional accuracy of the thickness of the transition layer 3 formed by the equipment. At the same time, the transition layer 3 will not be too thick, which will increase the weight of the speaker diaphragm and affect the sound quality. Further, optionally, the thickness of the metal base layer 2 is 0.1 to 0.2 μm, and the thickness of the transition layer 3 is 0.15 to 0.25 μm. This can effectively improve the bonding strength between the TAC composite film layer 4 and the substrate 1. At the same time, the optimal thickness combination of the metal base layer 2 and the transition layer 3 not only helps to ensure the firmness of the bonding between the TAC composite film layer 4 and the substrate 1, but also can make the speaker diaphragm have relatively ideal sound quality.

[0048] The thickness of the hard TAC film layer 40 is greater than that of the soft DLC film layer 41, and the thickness of the hard TAC film layer 40 is 0.1 to 0.3 μm, for example, the thickness of the hard TAC film layer 40 is 0.1 μm, 0.2 μm, or 0.3 μm. The thickness of the soft DLC film layer 41 is 0.05 to 0.1 μm, for example, the thickness of the soft DLC film layer 41 is 0.05 μm, 0.075 μm, or 0.1 μm. Setting the thickness of the hard TAC film layer 40 to be greater than the thickness of the soft DLC film layer 41 can ensure the hardness and rigidity of the entire TAC composite film layer 4, resulting in excellent sound effects for the speaker diaphragm.

[0049] The total number of film layers contained in the TAC composite film layer 4 can be two layers (refer to Figure 1 , the hard TAC film layer 40 and the soft DLC film layer 41 each have one layer) can also be multi-layered. When the number of layers is multi-layered (refer to Figure 2 and Figure 3), which is more conducive to increasing the thickness of the TAC composite film layer 4, thereby improving the acoustic quality of the speaker. In some embodiments, the total number of hard TAC film layers 40 and soft DLC film layers 41 in the speaker diaphragm is 10 to 300 layers. At this thickness, the TAC composite film layer 4 can improve the high-fidelity performance of the speaker; therefore, a suitable number of TAC composite film layers 4 can be selected between 10 and 300 layers according to demand. Further optionally, the total number of hard TAC film layers 40 and soft DLC film layers 41 is 20 to 100 layers. Preferably, the thickness of the TAC composite film layer 4 is 2 to 20 μm, which can balance the cost and performance of the speaker diaphragm.

[0050] As a preferred embodiment, the material of the metal bottom layer 2 is Ti, and the material of the transition layer 3 is TiC, which has comprehensive advantages in terms of cost and bonding strength.

[0051] In some embodiments, the material of the substrate 1 is aluminum, aluminum alloy, titanium, titanium alloy, beryllium, paper, carbon fiber, or plastic.

[0052] It is understandable that the film layer directly connecting the TAC composite film layer 4 and the transition layer 3 can be a hard TAC film layer 40 or a soft TAC film layer 41 .

[0053] The present invention also provides a method for preparing the loudspeaker diaphragm as described above, such as Figure 4 As shown, the following steps are included.

[0054] S1. Clean substrate 1.

[0055] S2. A metal base layer 2 is deposited on the surface of the substrate 1 by magnetron sputtering.

[0056] S3. The transition layer 3 is deposited on the surface of the metal bottom layer 2 by combining magnetron sputtering and magnetic filtered cathode vacuum arc technology.

[0057] S4. A hard TAC film layer 40 and a soft DLC film layer 41 are alternately deposited on the surface of the transition layer 3 using a magnetic filtered cathode vacuum arc technique.

[0058] The thickness of the TAC composite film layer 4 has a certain influence on the sound performance of the speaker. Generally speaking, the thicker the TAC composite film layer 4, the better the sound performance of the speaker. In the above-mentioned method for preparing the speaker diaphragm, the speaker diaphragm is prepared by combining the magnetron sputtering method and the magnetic filtration cathode vacuum arc technology. While increasing the thickness of the TAC composite film layer 4, the stress between the TAC composite film layer 4 and the substrate 1 is reduced. The TAC composite film layer 4 has both high hardness and low stress, thereby improving the sound performance of the speaker. At the same time, the speaker diaphragm is prepared by combining the magnetron sputtering method and the magnetic filtration cathode vacuum arc technology. The film deposition rate is high and the deposition area is large. The deposited film layer is more uniform, and the thickness of the film layer can be adjusted by the deposition time, which is convenient for production.

[0059] During the production process, auxiliary fixtures can be used to fix the diaphragm to reduce its deformation; the diaphragm to be plated is suspended on the workpiece rack, and the revolution-rotation method can achieve uniform coating of hundreds of diaphragms in a space of more than Φ800mm×850mm (height), which improves production efficiency.

[0060] The shape of the loudspeaker diaphragm can be spherical, annular, flat or other complex shapes.

[0061] The film color can be blue, black or interference color.

[0062] In some embodiments, step S1 includes the following steps:

[0063] Remove pollutants such as grease and dust from the surface of the substrate 1, place the substrate 1 in alcohol for dehydration and then dry; then hang the substrate 1 in a vacuum chamber of a coating machine for plasma cleaning.

[0064] Furthermore, plasma cleaning includes the following steps:

[0065] First, the vacuum chamber was evacuated to a vacuum of 5×10 -3 After achieving a vacuum of 1.5 Pa, the heater is turned on to heat the substrate to 100°C. High-purity argon gas is then introduced at a controlled flow rate of 10 to 70 sccm, and vacuum pumping is continued to maintain a process vacuum of 0.5 to 3.0 Pa. Next, the anode layer ion beam is activated at a voltage of 1000 to 2000 V, and the bias power supply is turned on at 800 to 2000 V, and the substrate 1 is plasma cleaned for 30 to 90 minutes. Plasma cleaning removes residual contaminants and impurities on the surface of the substrate 1, ensuring the secure bonding of the various film layers in subsequent processes.

[0066] In step S1, before placing the substrate 1 in the vacuum chamber of the coating machine, the substrate 1 can be fixed by a clamp to prevent the substrate 1 from deforming during the plasma cleaning process. At the same time, the clamp can facilitate the installation of the substrate 1 in the vacuum chamber of the coating machine.

[0067] In some embodiments, step S2 includes the following steps:

[0068] Under a process vacuum of 0.5 to 3.0 Pa, the material of the metal bottom layer 2 to be formed is used as the target material, the power of the magnetron sputtering power supply is controlled between 2 and 5 kW, and a negative bias voltage of -10 to -800 V is applied to the substrate 1. The deposition time is 10 to 60 minutes, thereby forming a metal bottom layer 2 with a thickness of 0.05 to 0.3 μm on the substrate 1.

[0069] In some embodiments, as Figure 5 As shown, step S3 includes the following steps:

[0070] S30. Turn on the medium frequency magnetron sputtering power supply and the metal target material of the same material as the metal bottom layer 2, and turn on the magnetic filtered cathode arc power supply and the corresponding graphite target;

[0071] S31. Control the power of the magnetron sputtering power supply between 2 and 5 kW, control the power of the magnetic filtered cathode arc power supply between 2 and 5 kW, control the vacuum degree to be maintained at 0.5 to 1 Pa, and maintain the temperature at 28 to 32 ° C;

[0072] S32. Apply a pulse negative bias voltage of -150 to -400 V on the surface of the metal base layer 2 for deposition coating, the duty cycle of the pulse negative bias voltage is 30% to 50%, the deposition time is 10 to 30 minutes, and a transition layer 3 with a thickness of 0.1 to 0.3 μm is formed on the metal base layer 2.

[0073] like Figure 6 As shown, in some embodiments, step S4 includes the following steps:

[0074] S40. Pump the vacuum degree of the vacuum chamber to below 5×10 -4 Pa, graphite is used as the target material of the magnetic filtered cathode arc, and the power supply of the magnetic filtered cathode arc is a pulse power supply.

[0075] S41. Adjust the temperature of the vacuum chamber and stabilize it at 80-85°C, apply a bias voltage of -300-1000V to the surface of the transition layer 3 for deposition coating, control the power of the magnetic filtered cathode arc power supply between 5-10kW, and the deposition time is 15-30min to obtain a hard TAC film layer 40 with a thickness of 0.1-0.3μm, wherein the bias power supply is a DC power supply.

[0076] S42. Apply a bias voltage of -50 to -300 V to the hard TAC film layer obtained in step S41, control the power of the magnetic filtered cathode arc power supply to be between 5 and 10 kW, continue deposition, and the deposition time is 5 to 10 minutes to obtain a soft DLC film layer 41 with a thickness of 0.05 to 0.1 μm, wherein the bias power supply is a DC power supply.

[0077] S43. Apply a bias voltage of -300 to -1000 V to the surface of the soft DLC film layer 41 obtained in step S42 for deposition coating, control the power of the magnetic filtered cathode arc power supply between 5 and 10 kW, and the deposition time is 15 to 30 minutes to obtain a hard TAC film layer 40 with a thickness of 0.1 to 0.3 μm, wherein the bias power supply is a DC power supply.

[0078] S44. Repeat steps S42 and S43 to obtain alternately stacked hard TAC film layers 40 and soft DLC film layers 41.

[0079] In the above step S4, after step S40 is completed, optionally, a bias voltage of -300 to -1000 V is first applied to the surface of the transition layer 3 to obtain a hard TAC film layer 40, or a bias voltage of -50 to -300 V is first applied to the surface of the transition layer 3 to obtain a soft DLC film layer 41, so that the hard TAC film layer 40 is directly connected to the transition layer 3, or the soft DLC film layer 41 is directly connected to the transition layer 3, that is, referring to Figure 7 , step S4 can also be the following step sequence:

[0080] S40. Pump the vacuum degree of the vacuum chamber to below 5×10 -4 Pa, graphite is used as the target material of the magnetic filtered cathode arc, and the power supply of the magnetic filtered cathode arc is a pulse power supply;

[0081] S41. The vacuum chamber temperature is adjusted and stabilized at 80-85°C. A bias voltage of -50-300V is applied to the surface of the transition layer 3 for deposition coating. The power of the magnetic filtered cathode arc power supply is controlled between 5-10kW and the deposition time is 5-10min. A soft DLC film layer 41 with a thickness of 0.05-0.1μm is obtained, wherein the bias power supply is a DC power supply.

[0082] S42. Applying a bias voltage of -300 to -1000 V to the soft TAC film obtained in step S41 for deposition coating, controlling the power of the magnetic filtered cathode arc power supply to be between 5 and 10 kW, and the deposition time to be 15 to 30 minutes, to obtain a hard TAC film layer 40 with a thickness of 0.1 to 0.3 μm, wherein the bias power supply is a DC power supply;

[0083] S43. A bias voltage of -50 to -300 V is applied to the surface of the hard DLC film 41 obtained in step S42 for deposition coating. The power of the magnetic filtered cathode arc power supply is controlled between 5 and 10 kW, and the deposition time is 5 to 10 minutes, to obtain a soft DLC film 41 with a thickness of 0.05 to 0.1 μm. The bias power supply is a DC power supply.

[0084] S44. Repeat steps S42 and S43 to obtain alternately stacked hard TAC film layers 40 and soft DLC film layers 41.

[0085] In steps S2, S3, and S4, the substrate 1, secured by a fixture, is suspended from a workpiece holder within the vacuum chamber. This revolution-rotation process allows for uniform coating of hundreds of speaker diaphragms, improving coating efficiency and reducing production costs. During the coating process, the substrate 1 can be shaped like a spherical cap, an annular ring, a flat surface, or other complex shapes.

[0086] Furthermore, after completing step S4, when the temperature of the vacuum chamber is less than 50°C, the vacuum valve is closed and the loudspeaker diaphragm with the TAC composite film layer 4 coated on the surface is taken out.

[0087] The following is a specific embodiment to further introduce the method for preparing the loudspeaker diaphragm of the present invention:

[0088] In this embodiment, the material of the substrate 1 is titanium, the material of the metal bottom layer 2 is titanium, and the material of the transition layer 3 is titanium carbide.

[0089] Before being placed in the vacuum chamber, the substrate 1 is dehydrated and dried in alcohol after removing pollutants such as grease and dust from its surface; the substrate 1 is then hung in the vacuum chamber of the coating machine.

[0090] The vacuum chamber was evacuated to a vacuum of 5×10 -3 After the vacuum degree reaches 1.0 Pa, the heater is turned on to heat to 100°C; then high-purity argon gas is introduced, the argon gas flow rate is controlled to 70 sccm, and vacuum is continued to maintain the process vacuum degree at 2.0 Pa; then, the anode layer ion beam is turned on with a voltage of 2000 V, the bias power supply is turned on with the bias power supply set at 2000 V, and the substrate is plasma cleaned for 60 minutes.

[0091] Then, under a process vacuum of 0.5 to 3.0 Pa, titanium is used as the target material, the power of the magnetron sputtering power supply is controlled at 5 kW, a negative bias voltage of -800 V is applied to the substrate 1, and the deposition time is 60 minutes, thereby forming a metal bottom layer 2 with a thickness of 0.3 μm on the substrate 1.

[0092] Then, a medium-frequency magnetron sputtering power supply and a titanium metal target were turned on, along with a magnetically filtered cathode arc power supply and a corresponding graphite target. The magnetron sputtering power supply was set to 5 kW. The magnetically filtered cathode arc power supply was set to 5 kW, the vacuum level was maintained at 1 Pa, and the temperature was maintained at 32°C. A 400V pulsed negative bias voltage was applied to the surface of the metal substrate 2 for deposition coating. The pulsed negative bias voltage had a duty cycle of 50%, and the deposition time was 30 minutes. A 0.3 μm thick transition layer 3 was formed on the metal substrate 2. The transition layer 3 was titanium carbide and had a thickness of 0.3 μm.

[0093] Finally, the vacuum chamber was evacuated to a vacuum level lower than 5×10 -4 Pa, graphite is used as the target material of the magnetic filtration cathode arc, and the power supply of the magnetic filtration cathode arc is a pulse power supply. The temperature of the vacuum chamber is adjusted and stabilized at 80°C, and a bias voltage of -800V is applied to the surface of the transition layer 3 for deposition coating. The power of the magnetic filtration cathode arc power supply is 8KW, and the deposition time is 15min, to obtain a 0.2μm thick hard TAC film layer 40. A bias voltage of -300V is applied to the hard TAC film layer prepared above, and the power of the magnetic filtration cathode arc power supply is 8KW. Deposition is continued for 10min to obtain a 0.1μm thick soft DLC film layer 41. Repeat the above method to obtain alternating superposition of hard TAC film layers 40 and soft DLC film layers 41. Among them, the bias power supplies are all DC power supplies.

[0094] The above is only a specific implementation of the present invention, and any other improvements made based on the concept of the present invention are considered to be within the scope of protection of the present invention.

Claims

1. A loudspeaker diaphragm, characterized in that: include: substrate (1); A metal bottom layer (2) is provided on the surface of one side or both sides of the substrate (1), the material of the metal bottom layer (2) is Cr, Ti or Ni, and the thickness of the metal bottom layer (2) is 0.05 to 0.3 μm; A transition layer (3) is provided on the surface of the metal base layer (2), wherein the material of the transition layer (3) is a carbide of the material of the metal base layer (2), and the thickness of the transition layer (3) is 0.1 to 0.3 μm; and The TAC composite film layer (4) is arranged on the surface of the transition layer (3), and comprises a hard TAC film layer (40) and a soft DLC film layer (41) that are alternately stacked.

2. The loudspeaker diaphragm according to claim 1, wherein The transition layer (3) has a thickness of 0.15 to 0.25 μm.

3. The loudspeaker diaphragm according to claim 1, wherein The thickness of the metal bottom layer (2) is 0.1-0.2 μm.

4. The loudspeaker diaphragm according to claim 1, wherein: The thickness of the hard TAC film layer (40) is greater than the thickness of the soft DLC film layer (41).

5. The loudspeaker diaphragm according to claim 4, wherein: The thickness of the hard TAC film layer (40) is 0.1 to 0.3 μm, and the thickness of the soft DLC film layer (41) is 0.05 to 0.1 μm.

6. The loudspeaker diaphragm according to claim 5, wherein: The total number of layers of the hard TAC film layer (40) and the soft DLC film layer (41) is 10 to 300 layers.

7. The loudspeaker diaphragm according to claim 6, wherein: The total number of layers of the hard TAC film layer (40) and the soft DLC film layer (41) is 20 to 100 layers.

8. The loudspeaker diaphragm according to claim 5, wherein: The thickness of the TAC composite film layer (4) is 2 to 20 μm.

9. The loudspeaker diaphragm according to any one of claims 1 to 8, wherein: The film layer in the TAC composite film layer (4) connected to the transition layer (3) is a hard TAC film layer (40) or a soft DLC film layer (41).

10. The loudspeaker diaphragm according to any one of claims 1 to 8, wherein: The material of the metal bottom layer (2) is Cr, and the material of the transition layer (3) is Cr3C2; or, the material of the metal bottom layer (2) is Ti, and the material of the transition layer (3) is TiC; or, the material of the metal bottom layer (2) is Ni, and the material of the transition layer (3) is Ni3C; The material of the substrate (1) is aluminum, aluminum alloy, titanium, titanium alloy, beryllium, paper, carbon fiber or plastic.

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