Dome for sound-generating device, diaphragm assembly, sound-generating device and electronic equipment

Abstract

The present invention discloses a dome for a sound-generating device, a diaphragm assembly, a sound-generating device and an electronic device; wherein the dome for the sound-generating device comprises an organic aerogel material, the dome has an open channel extending in the thickness direction of the dome; the surface of the dome has air holes connected to the open channel, the aperture of the air holes is 0.05 μm to 20 μm; the water drop angle range of the dome surface is ≥80°. According to the dome of the present invention, the dome is made of an organic aerogel material, the dome made of the organic aerogel material has a channel extending in the thickness direction thereof, and the surface of the dome has air holes connected to the open channel. The channels and air holes formed on the dome can balance the air pressure on both sides of the dome. The aperture of the air holes is smaller than the diameter of the water droplets, so that it can also play a waterproof and breathable effect, thereby improving the waterproof performance of the sound-generating device.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic equipment, and more specifically, to a dome for a sound-generating device, a diaphragm assembly, a sound-generating device and an electronic device. Background Art

[0002] In recent years, electroacoustic devices have been developing towards being thinner, more powerful, and more high-frequency. Consumers have increasingly higher requirements for the sound quality of audio equipment, and have put forward more requirements for the reliability and waterproof performance of audio equipment. Electroacoustic devices with better waterproofness will have better sealing, which will cause the heat generated by the electroacoustic device during operation to cause the air in the cavity to expand, pushing the diaphragm to deviate from the equilibrium position and vibrate, resulting in obvious noise.

[0003] In the existing related technologies, in order to solve the above problems, the solution adopted is to provide a damping hole connected to the outside world on the outer shell or the dome corresponding to the position of the rear sound cavity, which can be used to dissipate heat and balance the air pressure in the rear sound cavity, so that the diaphragm can vibrate freely. However, the assembly process of opening the damping hole is complicated and there is a certain waterproof risk. Summary of the invention

[0004] An object of the present invention is to provide a new technical solution for a dome, a diaphragm assembly, a sound-generating device and an electronic device.

[0005] According to a first aspect of the present invention, there is provided a dome for a sound-generating device, the dome comprising an organic aerogel material, the dome having an open channel extending in a thickness direction of the dome;

[0006] The surface of the dome has air holes connected to the open hole channel, and the pore size of the air holes is 0.05 μm to 20 μm;

[0007] The water drop angle range of the top surface of the ball is ≥80°.

[0008] Optionally, the organic aerogel material includes at least one of polyimides, polyamides, polyesters, aldehydes, polyolefins, polysaccharides and silicones.

[0009] Optionally, the main chain of the organic aerogel material contains an imide ring, and the imide ring is an aliphatic imide and / or an aromatic imide.

[0010] Optionally, the structure of the aliphatic imide comprises:

[0011]

[0012] Optionally, the structure of the aromatic imide comprises:

[0013]

[0014] Optionally, the dome further includes a reinforcing material, and the reinforcing material is reinforcing fibers and / or reinforcing particles.

[0015] Optionally, the mass percentage of the reinforcement material to the total weight of the dome is 0-80%.

[0016] Optionally, the reinforcing fiber is at least one of chopped fiber, continuous fiber, fabric and non-woven fabric;

[0017] The reinforcing particles are at least one of inorganic particles of boron nitride, silicon carbide, carbon black, aluminum oxide and metal particles.

[0018] Optionally, the gas permeability of the spherical top is 2.8×10 -3 cm 3 / cm 2 ·s·Pa~0.1cm 3 / cm 2 ·s·Pa.

[0019] Optionally, the density of the dome is 0.05 g / cm 3 ~1g / cm 3 .

[0020] Optionally, the modulus of the dome is greater than 1 GPa;

[0021] And / or, when the dome is deformed by 10%, the compression strength of the dome is 0.7 MPa to 100 MPa.

[0022] Optionally, the thickness of the dome is 40 μm to 300 μm.

[0023] Optionally, the organic aerogel molecules in the spherical top have fluorine-containing groups.

[0024] According to a second aspect of the present invention, a diaphragm assembly is provided, which is applied to a sound-generating device, and the diaphragm assembly comprises:

[0025] a diaphragm; and

[0026] The dome as described above, wherein the dome is bonded to the diaphragm;

[0027] Alternatively, the dome and the diaphragm are integrally injection molded.

[0028] According to a third aspect of the present invention, a sound-generating device is provided, the sound-generating device comprising the diaphragm assembly as described above.

[0029] According to a fourth aspect of the present invention, there is provided an electronic device, the electronic device comprising the sound generating device as described above.

[0030] The dome of the present invention is made of an organic aerogel material, which can make the dome have a porous interlaced network structure. The interior of the dome has a channel extending along its thickness direction, and the surface of the dome has air holes connected to the open hole channel. This structural feature can make the air on both sides of the dome communicate with each other, playing a role in balancing the air pressure. Furthermore, the aperture of the air hole is smaller than the diameter of the water droplet, so that it can also play a waterproof and breathable effect, thereby improving the waterproof performance of the sound-generating device.

[0031] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0033] Figure 1 This is one of the structural schematic diagrams of the dome provided by the embodiment of the present invention.

[0034] Figure 2 This is the second structural schematic diagram of the dome provided by the embodiment of the present invention.

[0035] Figure 3 This is the third structural schematic diagram of the dome provided by the embodiment of the present invention.

[0036] Figure 4 It is one of the structural schematic diagrams of the diaphragm assembly provided in an embodiment of the present invention.

[0037] Figure 5 This is the second structural schematic diagram of the diaphragm assembly provided in an embodiment of the present invention.

[0038] Figure 6 It is a comparison chart of total harmonic distortion (THD) test curves of the sound-generating device provided by an embodiment of the present invention and the existing sound-generating device with a sealed rear sound cavity.

[0039] Description of reference numerals:

[0040] 100, dome; 110, opening channel; 120, air vent; 200, diaphragm. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0042] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0043] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0044] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0045] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0046] See also Figures 1 to 3 The embodiment of the present invention provides a dome 100 for a sound-emitting device, wherein the dome 100 includes an organic aerogel material, and the dome 100 has an open channel 110 extending along the thickness direction of the dome 100; the surface of the dome 100 has an air vent 120 connected to the open channel 110, and the pore size of the air vent 120 is 0.05 μm to 20 μm; the water drop angle range of the surface of the dome 100 is ≥80°.

[0047] Optionally, the dome 100 may be a flat plate structure, such as Figure 1 shown.

[0048] Of course, if Figure 2 As shown, the dome 100 may also be a convex hull structure, or other special-shaped structures, which is not specifically limited in the present invention.

[0049] It should be noted that the dome 100 is at least formed of an organic aerogel material.

[0050] In some examples of the present invention, Figure 3 As shown, the dome 100 may include an organic aerogel layer.

[0051] Of course, the dome 100 is not limited to including only one organic aerogel layer, and the dome 100 may also include multiple organic aerogel layers.

[0052] For example, the dome 100 may include two layers of organic aerogel layers, or three layers of organic aerogel layers, etc., which can be selected according to actual needs.

[0053] The dome is usually set on the diaphragm to enhance the strength of the diaphragm. The various properties of the dome have a very important impact on the sound performance of the entire sound-generating device. In some sound-generating devices, the dome needs to meet the properties of low density, high strength, waterproof and breathable at the same time.

[0054] In the present invention, the dome 100 includes an organic aerogel layer, which can be formed of an organic aerogel material. The organic aerogel material is a high-porosity, low-density material. When it is used as a material for making the dome in the micro sound-generating device, the sound-generating device can obtain low-density, high-strength and other properties. Since the density of the dome is relatively low, the mass of the vibration system of the sound-generating device can be reduced, which is beneficial to improving the intermediate frequency sensitivity of the sound-generating device. In turn, the sound-generating device can have excellent intermediate frequency performance.

[0055] In the present invention, in addition to the advantages of low density and high strength, the organic aerogel material has many open channels 110 inside. Figure 3 As shown, after it is used to make the dome 100, the dome 100 will have an opening channel 110 inside. It should be noted that the dome 100 is not a straight channel, but a plurality of winding opening channels 110 of uneven sizes. The curved channel structure makes the formed dome 100 have a very high water pressure resistance, which is conducive to making the dome 100 have excellent waterproof performance.

[0056] The minimum diameter of the water droplets formed by water vapor is not less than 20 μm, and the diameter of the water droplets is usually about 100 μm. The pore size of the air pores 120 on the surface of the dome 100 of the present invention is 0.05 μm to 20 μm, which is much smaller than the diameter of the water droplets. Therefore, when water droplets fall on the surface of the dome 100, it is difficult for the water droplets to penetrate the dome 100. In this way, the dome 100 can better achieve the performance of being breathable and impermeable, and can give the dome good waterproofness. Optionally, the pore size of the air pores 120 on the surface of the dome 100 can be 0.05 μm, 1 μm, 3 μm, 5 μm, 7 μm, 9 μm, 10 μm, 11 μm, 13 μm, 15 μm, 17 μm, 19 μm and 20 μm, etc., and there is no specific limitation on this in the embodiments of the present invention.

[0057] When the pore diameter of the air pore 120 is 5 μm to 15 μm, the structure of the dome 100 can be stabilized and the dome 100 can have excellent waterproof and breathable properties.

[0058] In the present invention, the water drop angle range on the surface of the dome 100 is ≥80°.

[0059] The ball top 100 is made of an organic aerogel material, which can provide the surface of the ball top 100 with a plurality of air holes 120. The larger the aperture of the air hole 120 and the smaller the water drop angle, the greater the gas permeation amount. The smaller the aperture of the air hole 120 on the surface of the ball top 100 and the larger the water drop angle, the lotus effect will occur where the water drop cannot wet the surface and rolls.

[0060] In the present invention, the water drop angle range on the surface of the dome 100 is designed to be relatively large, so that the water droplets cannot wet the surface of the dome 100 after falling on the surface of the dome 100, thereby achieving a waterproof effect.

[0061] Optionally, the surface water drop angle of the dome 100 ranges from 80°, 85°, 90°, 95°, etc., which is not limited in the embodiment of the present invention.

[0062] When the angle range of water drops on the surface of the dome 100 is greater than 85°, the water drops falling on the surface of the dome 100 cannot wet the surface at all, so that the dome 100 can achieve a better waterproof effect.

[0063] According to the dome 100 of the present invention, the dome 100 is made of an organic aerogel material, which can make the dome 100 have a porous interlaced network structure, and the dome 100 has a channel extending along its thickness direction inside, and the surface of the dome 100 has a vent 120 connected to the open channel 110, so that it can communicate with the air flow outside to balance the air pressure. Moreover, the aperture of the vent 120 is smaller than the diameter of a water droplet, so that it can also play a waterproof and breathable effect, and improve the waterproof performance of the sound-generating device.

[0064] In addition, the dome 100 of the embodiment of the present invention can be lightweight based on the characteristics of the organic aerogel material, while also having the strength, stiffness, and damping properties required for vibration control systems.

[0065] In some examples of the present invention, the gas permeability of the dome 100 is 2.8×10 -3 cm 3 / cm 2 ·s·Pa~0.1cm 3 / cm 2 ·s·Pa.

[0066] Optionally, the gas permeability of the spherical top 100 may be 2.8×10 -3 cm 3 / cm 2 ·s·Pa, 1.5×10 - 3 cm 3 / cm 2 ·s·Pa, 1×10 -3cm 3 / cm 2 s Pa, 0.5×10 -3 cm 3 / cm 2 ·s·Pa, 0.05cm 3 / cm 2 ·s·Pa.

[0067] When the gas permeation rate of the spherical top 100 is 1.5×10 -3 cm 3 / cm 2 ·s·Pa~0.05cm 3 / cm 2 ·s·Pa, the dome 100 can achieve excellent breathability while being waterproof, and will not affect the rigidity, damping and other properties of the dome 100.

[0068] In the present invention, the aperture size of the air holes 120 on the surface of the dome 100 has a certain influence on the water drop angle and gas permeation rate on the surface of the dome 100. Take the dome of the same thickness as an example for explanation:

[0069] The larger the aperture of the air holes 120 on the surface of the dome 100 is, the smaller the water drop angle is, and the greater the gas permeation rate is.

[0070] The smaller the aperture of the vent hole 120 on the surface of the dome 100, the larger the angle of the water droplet, and the lotus effect that the water droplet cannot wet the surface and rolls will appear. The vent hole 120 with a smaller aperture can prevent the water droplets dripping onto the surface of the dome 100 from entering the opening channel 110 of the dome 100.

[0071] In the present invention, the relationship between the aperture of the air hole 120 on the surface of the dome 100 , the water drop angle on the surface of the dome 100 , and the gas permeation rate can be shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] The dome 100 of organic aerogel material has a porous interlaced network structure, which can realize airflow communication with the outside world. When there is a pressure difference and temperature gradient between the two surfaces of the dome 100, the gas can pass through the open hole channel 110 that is tortuous and connected in the thickness direction of the dome 100, or move from one channel to another, and diffuse from a high-concentration area to a low-concentration area. When the dome 100 of the present invention is applied to a sound-generating device, it can balance the air pressure in the rear sound cavity, enable the diaphragm provided with the dome to vibrate freely, and the sound-generating device has a good sound-generating effect.

[0076] It should be noted that in the present invention, the aperture size of the air pores 120 formed on the surface of the dome 100 can be adjusted by controlling the growth rate of ice crystals. That is, in the preparation of the organic aerogel material, the aperture size of the openings on the surface of the dome 100 can be adjusted by controlling the freezing rate. Specifically, when the freezing rate is fast, the number of crystal nuclei formed is relatively large, the crystal grains formed will be relatively small, and the aperture size of the holes formed after drying will be relatively small. When the freezing rate is slow, the size of the crystal nuclei formed will be relatively large, and the aperture size of the holes formed after drying will be relatively large.

[0077] In the present invention, the pore size of the air holes 120 on the surface of the dome 100 is 0.05 μm to 20 μm, so that the dome 100 can be air-permeable and water-tight, thereby giving the dome 100 good waterproof performance.

[0078] In some examples of the present invention, the density of the dome 100 is 0.05 g / cm 3 ~1g / cm 3 For example, the density of the dome 100 may be 0.1 g / cm 3 , 0.2g / cm 3 , 0.3g / cm 3 g, 0.5g / cm 3 , 0.7g / cm 3 , 1.0g / cm 3 wait.

[0079] The density of the dome 100 will directly affect the weight of the dome and the diaphragm assembly. If the density of the dome is too low, the stiffness of the dome and the diaphragm assembly will be low, and it will be difficult to meet the stiffness requirements of the diaphragm assembly. If the density of the dome is too high, the weight of the dome and the diaphragm assembly will be large, which is not conducive to the lightweight design of the sound-generating device, and will also affect the mid-frequency sensitivity of the sound-generating device.

[0080] When the density of the dome 100 is 0.2 g / cm 3 ~0.7g / cm 3 At the same time, the dome 100 has the characteristics of light weight and stable structure, and can be used in a sound-generating device to simultaneously meet the strength and stiffness required for the vibration of the vibration system.

[0081] The dome of the present invention is mainly made of organic aerogel. Organic aerogel material is a solid material with large porosity and high specific surface area. Most of its volume is composed of air, which can account for 80% to 99.8% of the total volume of the material. Compared with metal foil and engineering plastics, the organic aerogel dome formed has the characteristic of light weight.

[0082] In some examples of the present invention, the modulus of the dome 100 is greater than 1 GPa; and / or, when the dome 100 is deformed by 10%, the compressive strength of the dome 100 is 0.7 MPa to 100 MPa.

[0083] The modulus of the dome 100 of the present invention is relatively large, which can reach greater than 1 GPa, so that the dome 100 has the characteristic of relatively large rigidity; at the same time, it is also beneficial to improve the high-frequency performance of the sound-generating device product.

[0084] At the same time, the dome 100 of the present invention also has a relatively large compression strength, so that the dome can withstand a certain pressure, and the dome is not easy to deform during long-term use, and is not easy to be scratched, broken, or other undesirable phenomena.

[0085] The modulus of the dome 100 of the present invention can be 1 GPa, 1.5 GPa, 2 GPa, 2.5 GPa, 3 GPa, etc., or even greater, which is not limited in the embodiments of the present invention. When the dome is deformed by 10%, the compressive strength of the dome 100 can be, for example, 0.7 MPa, 10 MPa, 30 MPa, 50 MPa, 70 MPa, 90 MPa, 100 MPa, etc., which is not limited in the embodiments of the present invention.

[0086] When the modulus of the dome 100 is greater than 1 GPa and the compressive strength of the dome 100 is between 0.7 MPa and 100 MPa, based on the large modulus and compressive strength of the dome 100, the strength and rigidity of the dome 100 can be greatly improved. The dome 100 is less likely to experience split vibration during vibration, which makes the overall hearing of the sound-emitting device better.

[0087] In some examples of the present invention, the thickness of the dome 100 is 40 μm to 300 μm.

[0088] It should be noted that the high-frequency cutoff frequency Fh of the sound-generating device is related to the thickness of the dome.

[0089] If the thickness of the dome is too small, the cutoff frequency of the sound-generating device using the dome will be too low. If the thickness of the dome is too large, it will affect the vibration space in the sound-generating device.

[0090] For example, the thickness of the ball top 100 is 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, etc., which is not limited in the embodiment of the present invention.

[0091] When the thickness of the dome 100 is between 80 μm and 250 μm, the high frequency cutoff frequency Fh of the sound-generating device can be increased without affecting the vibration space in the sound-generating device. At the same time, since the material of the dome 100 is a low-density material, the overall weight of the dome will not increase at this thickness.

[0092] In some examples of the present invention, the substrate for making the dome 100 is an organic aerogel material, and the organic aerogel material includes at least one of polyimide, polyamide, polyester, aldehyde, polyolefin, polysaccharide and silicone.

[0093] In the present invention, the base material of the dome 100 is an organic aerogel, the skeleton of the organic aerogel comprises an organic polymer, and the organic polymer comprises at least one of polyimide, polyamide, polyester, aldehyde, polyolefin, polysaccharide and silicone.

[0094] Organic aerogel is an organic polymer material formed by the sol-gel method. During the preparation process, the gas replaces the liquid phase in the gel through drying, thereby forming a solid material with a nano-scale porous structure, which also has the properties of a gel. This material is the organic aerogel material used in the present invention.

[0095] In the present invention, the skeleton of the organic aerogel can be an aerogel made of a polymer organic material, which not only has the characteristics of being porous and light, but also has a certain rigidity compared to inorganic aerogel materials. It can be used to prepare the dome 100, so that the prepared dome 100 has the characteristics of being light in weight and high in strength, and can meet the strength, stiffness, and damping performance required for the vibration of the vibration system in the sound-generating device.

[0096] In practical applications, one or more of the above-mentioned organic polymer materials may be selected according to the actual requirements of the dome 100 .

[0097] In some examples of the present invention, the dome 100 includes an organic aerogel material, the main chain of the organic aerogel material contains an imide ring, and the imide ring is an aliphatic imide and / or an aromatic imide.

[0098] Wherein, the structure of the aliphatic imide comprises:

[0099]

[0100] Wherein, the structure of the aromatic imide comprises:

[0101]

[0102] In some examples of the present invention, the organic aerogel molecules in the ball top 100 have fluorine-containing groups.

[0103] From the molecular structure formula of the above-mentioned aliphatic polyimide and aromatic polyimide, the molecular structure formula of aliphatic polyimide and aromatic polyimide both contain an imide ring structure. The material containing the imide ring structure can be hydrophobically treated by a fluorine-containing monomer during the synthesis of polyimide aerogel, which can make the prepared dome have good hydrophobic properties, that is, the dome has better waterproof properties.

[0104] Moreover, when the main chain of the organic aerogel material contains an imide ring, an ultra-light polyimide aerogel material with a highly porous interlaced network structure can be formed. This material has excellent thermal stability, mechanical properties, dimensional stability, chemical resistance, insulation and other properties, making it suitable for use in sound-generating devices.

[0105] That is to say, in the present invention, the base material for making the dome 100 can be a polyimide-based organic aerogel material. The polyimide-based organic aerogel material has a network structure of holes that are crisscrossed inside and has the characteristics of low density. Under the same size conditions, the polyimide-based organic aerogel material can reduce the mass of the dome to the maximum extent, thereby achieving the effect of reducing the resonant frequency of the sound-generating device and improving the mid-frequency sensitivity of the sound-generating device.

[0106] It should be noted that, in practical applications, the organic aerogel substrate for preparing the dome 100 can be prepared by using one of aliphatic polyimide and aromatic polyimide, or by mixing the two materials, and the present invention does not limit this.

[0107] In addition, it should be noted that the use of organic aerogel materials to make dome tops also has the characteristics of simple molding process. The dome top can be made into specific shapes according to needs, and the yield is high. Due to the simple process, the cost can be appropriately reduced, which greatly expands the promotion and application of organic aerogel materials in sound-generating device products.

[0108] In some examples of the present invention, the dome 100 further includes a reinforcing material, which may be reinforcing fibers and / or reinforcing particles.

[0109] Optionally, the mass percentage of the reinforcement material to the total weight of the dome 100 is 0-80%.

[0110] That is, in the present invention, the dome 100 may contain reinforcing material in addition to the organic aerogel material, and the reinforcing material accounts for 0 to 80% by weight of the total weight of the dome 100. Preferably, the reinforcing material accounts for 0 to 60% by weight of the total weight of the dome 100.

[0111] Optionally, the above-mentioned reinforcing material may be reinforcing fibers and / or reinforcing particles, wherein the reinforcing fibers are at least one of chopped fibers, continuous fibers, fabrics and non-woven fabrics.

[0112] Optionally, the reinforcing particles may be inorganic particles, such as at least one of boron nitride, silicon carbide, carbon black, aluminum oxide and metal particles.

[0113] As shown in Table 2, the spherical top 100 of the present invention has a bending modulus and a compressive strength that first increase and then decrease as the proportion of the reinforcing material in the spherical top 100 increases. This is because: as the content of the reinforcing material increases, the intermolecular force per unit volume is strong, and when the pore structure of the spherical top 100 collapses, the reinforcing material therein can play a bridging role, so the bending modulus and the compressive strength of the spherical top 100 are improved.

[0114] Table 2

[0115] Reinforcement material mass fraction 0 50 60 80 90 Compression strength of dome / (MPa) 0.7 60 84 90 0.4 Bending modulus of dome / (MPa) 60 4000 8000 5500 20

[0116] It should be noted that when the proportion of the reinforcement material in the dome 100 is relatively large, for example, greater than 80%, the aerogel skeleton structure of the composite reinforcement material obtained is very fragile and even cannot be formed. In this case, the bending modulus and compression strength of the dome 100 are very low. Therefore, it is necessary to reasonably control the mass proportion of the reinforcement material in the dome 100. Optionally, the proportion of the reinforcement material in the dome can be, for example, 1%, 5%, 10%, 20%, 40%, 60%, 80%, etc.

[0117] The proportion of the reinforcing material in the dome 100 used in the present invention meets the requirements of the dome molding process, and the reinforcement effect of the dome 100 is good and can meet the vibration requirements of the diaphragm assembly.

[0118] In the present invention, the organic aerogel molecules of the ball top 100 have fluorine-containing groups. Specifically, the water absorption rate of the ball top 100 characterizes its hydrophobic effect. The imide ring structure is a polar group with water absorption. In the process of synthesizing polyimide aerogels having an imide ring structure, the water absorption rate of the polyimide aerogel can be reduced by introducing a monomer containing a fluorine structure. The fluorine-containing group can combine with carbon elements to form a microstructure with weaker polarity, thereby reducing the adsorption performance.

[0119] The embodiment of the present invention further provides a method for preparing the spherical top 100, the method comprising the following steps:

[0120] Step S1, polymerizing dianhydride and diamine monomers, crosslinking agents, dispersants and other auxiliary agents in a certain proportion to obtain a polyamic acid salt hydrogel; wherein the dianhydride and diamine monomers are selected from CF group monomers containing fluorine atoms. Accordingly, the more polar CH bonds are reduced, so that the water absorption rate of the finally synthesized polyimide aerogel can be effectively reduced.

[0121] Optionally, the diamine monomer is at least one of 4,4'-diaminoanisole, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 4,4-diaminodiphenyl ether, p-phenylenediamine, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2-(4-aminophenyl)-5-aminobenzimidazole, 2,2'-bis-(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl sulfone, 1,4-diaminobenzene, 2,2'-bis[4-(4-aminophenoxy)phenyl6-yl]propane and 9,9'-bis(4-aminophenyl)fluorene.

[0122] Optionally, the dianhydride monomer is at least one of pyromellitic anhydride, 3,3',4,4'-biphenyltetracarboxylic anhydride, 3,3'4,4'-benzophenonetetracarboxylic anhydride, 4,4'-hexafluoroisopropylphthalic anhydride, 4,4'-biphenyl ether dianhydride and hexafluoro dianhydride.

[0123] Step S2, pressing the polyamic acid salt hydrogel in step S2 through a spherical top mold to form a mold.

[0124] Step S3, after step S2, freeze-drying the preliminarily formed polyamic acid salt hydrogel, and subjecting it to a thermal imidization process after shaping, to finally obtain a formed polyimide aerogel.

[0125] The freeze-drying conditions are: temperature ≤ 15°C, vacuum degree ≤ 500Pa, and freezing time 2h to 10h. The thermal imidization conditions are: temperature 250°C to 350°C, and insulation time 0.5h to 1.5h.

[0126] During the preparation process, since the fluorine atoms have very small electronic polarization and large electronegativity, they will form high-energy CF bonds, which prevent the fluorine atoms from forming hydrogen bonds with hydrogen in water molecules. In the finally synthesized polyimide aerogel, as the fluorine atom content increases, the water absorption rate of the polyimide organic aerogel containing an imide ring structure will decrease. Applying it to the dome can reduce its water absorption rate to less than 5%. For example, the water absorption rate can reach 4%, 3%, 2% or even lower, so that the dome can withstand storage under high humidity conditions, expanding the use environment conditions of the sound-generating device.

[0127] In addition, in another example of the present invention, the dome 100 may include an aerogel material and a reinforcing material, and a method for preparing the dome 100 includes:

[0128] Step S1, polymerizing dianhydride and diamine monomers, crosslinking agents, dispersants and other auxiliary agents in a certain proportion to obtain a polyamic acid salt hydrogel; wherein the dianhydride and diamine monomers are selected from CF group monomers containing fluorine atoms. Accordingly, the more polar CH bonds are reduced, so that the water absorption rate of the finally synthesized polyimide aerogel can be effectively reduced.

[0129] Step S2, preparing a mixed solution of polyamic acid salt hydrogel and an organic hydrogel of a reinforcing material, placing the mixed organic hydrogel solution in a ball top forming mold, and taking out the composite hydrogel ball top after hot pressing.

[0130] Optionally, the diamine monomer is at least one of 4,4'-diaminoanisole, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 4,4-diaminodiphenyl ether, p-phenylenediamine, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2-(4-aminophenyl)-5-aminobenzimidazole, 2,2'-bis-(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl sulfone, 1,4-diaminobenzene, 2,2'-bis[4-(4-aminophenoxy)phenyl6-yl]propane and 9,9'-bis(4-aminophenyl)fluorene.

[0131] Optionally, the dianhydride monomer is at least one of pyromellitic anhydride, 3,3',4,4'-biphenyltetracarboxylic anhydride, 3,3'4,4'-benzophenonetetracarboxylic anhydride, 4,4'-hexafluoroisopropylphthalic anhydride, 4,4'-biphenyl ether dianhydride and hexafluoro dianhydride.

[0132] Among them, the reinforcing material can be reinforcing fibers and / or reinforcing particles; the reinforcing fibers are at least one of chopped fibers, continuous fibers, fabrics and non-woven fabrics; the reinforcing particles are at least one of inorganic particles boron nitride, silicon carbide, carbon black, aluminum oxide and metal particles.

[0133] The mass percentage of the reinforcing material to the total weight of the dome 100 is 0-80%.

[0134] Step S3, after step S2, freeze-drying the preliminarily formed composite hydrogel spherical top, and after shaping, performing a thermal imidization process to finally obtain a formed composite aerogel spherical top.

[0135] The freeze-drying conditions are: temperature ≤ 15°C, vacuum degree ≤ 500Pa, and freezing time 2h to 10h. The thermal imidization conditions are: temperature 250°C to 350°C, and insulation time 0.5h to 1.5h.

[0136] The dome prepared by the above two molding methods has good thickness consistency.

[0137] The embodiment of the present invention further provides a diaphragm assembly, which can be applied to a sound-generating device. The diaphragm assembly, such as Figure 4 and 5 As shown, it comprises: a diaphragm 200 and the dome 100 described in any of the above embodiments, wherein the dome 100 is bonded to the diaphragm 200; or, the dome 100 and the diaphragm 200 are integrally injection molded.

[0138] Optionally, the dome 100 can be bonded to the diaphragm 200 using an adhesive such as glue or tape. The bonding width between the dome and the diaphragm is not less than 1 mm, which can improve the bonding strength between the dome and the diaphragm.

[0139] Of course, the dome 100 can also be integrally injection molded with the diaphragm 200. This method has high structural stability and avoids polarization of the diaphragm component during the sound generation process of the sound generation device.

[0140] The diaphragm 200 may be made of engineering plastics, for example. The engineering plastics include polyetheretherketone (PEEK), PAR, etc. The diaphragm 200 may also be made of elastomeric materials, for example. The elastomeric materials include thermoplastic polyurethane elastomer (TPU), thermoplastic polyester elastomer (TPEE), rubber, etc.

[0141] In addition, the diaphragm 200 may also be made of adhesive film, such as acrylic adhesive, silicone adhesive, etc.

[0142] Of course, the diaphragm 200 may also be made of a composite of the above-mentioned materials, and the present invention does not limit this.

[0143] In the present invention, the thickness of the diaphragm 200 can be designed to be between 0.01 mm and 0.5 mm, which can be suitable for use in the vibration space of most sound-generating devices.

[0144] For example, the thickness of the diaphragm 200 may be 0.01 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm, which is not limited in the embodiment of the present invention.

[0145] The diaphragm assembly provided by the embodiment of the present invention is based on the base material of the dome 100 being an organic aerogel material, so that the weight of the dome 100 can be made lighter, so that the thickness of the dome 100 can be appropriately increased, thereby improving the high-frequency sensitivity and cutoff frequency of the sound-generating device, and the sound-generating device can obtain a better sound effect at a wider frequency. At the same time, based on the organic aerogel having an open hole channel 110, and adjusting the aperture of the air hole 120 on the surface of the dome 100 to be smaller and the water drop angle to be larger, the dome 100 on the diaphragm assembly can have good air permeability and waterproof performance.

[0146] An embodiment of the present invention further provides a sound-generating device, which includes the above-mentioned diaphragm assembly.

[0147] The sound generating device provided by the embodiment of the present invention can be used in various electronic devices.

[0148] An embodiment of the present invention further provides an electronic device, which includes the sound-generating device as described above.

[0149] The electronic device may be, for example, a mobile phone, a laptop computer, a tablet computer, a VR (virtual reality) device, an AR (augmented reality) device, a TWS (true wireless Bluetooth) headset, a smart speaker, etc., and the present invention is not limited to this.

[0150] In order to make the technical scheme and corresponding technical effects of the present invention clearer, the present invention specifically provides the following embodiments and comparative examples to specifically illustrate the technical scheme.

[0151] The embodiment is a dome made of polyimide organic aerogel material, and the comparative example is a dome made of PEN material. The domes in the embodiment and the comparative example have the same thickness and shape.

[0152] The method for making the dome of the embodiment is as follows:

[0153] Step 1: 86.512g (0.8mol) of p-phenylenediamine is dissolved in 1L of N-methylpyrrolidone, and 294g (1mol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride is added under stirring. When adding 3,3',4,4'-biphenyltetracarboxylic dianhydride, a small amount and multiple times can be used; after the addition of 3,3'4,4'-benzophenonetetracarboxylic dianhydride is completed, the formed mixture is polymerized in an ice water bath for 3h to obtain a polymer reactant; 8g (0.02mol) of a cross-linking agent is added to the obtained polymer reactant, and the cross-linking agent is 1,3,5-tris (aminophenoxy) benzene, and a polyamic acid salt solution can be obtained; the obtained polyamic acid salt solution is slowly poured into acetone, and the precipitated filaments obtained by precipitation are polyimide materials, and the polyimide material is dried to constant weight.

[0154] Step 2: Take 5 g of the polyimide material obtained in step 1 and configure it into an organic hydrogel mixed solution with a polyamide salt mass fraction (solid content) of 30%, place the organic hydrogel mixed solution between the upper and lower molds of the spherical top, and place the mold on a hot pressing molding machine, hot press molding at 60°C, take it out after cooling, and obtain an organic hydrogel film layer with a spherical top shape.

[0155] Step 3: Place the organic hydrogel film layer prepared in step 2 in a -50°C atmosphere for freeze drying to obtain an organic aerogel film layer.

[0156] Step 4: Place the organic aerogel film layer obtained in step 3 in an oven and perform a thermal crosslinking treatment by programmed temperature increase (180° C. / 1 h, 350° C. / 4 h) to obtain the organic aerogel dome for the sound-generating device provided by the present invention.

[0157] Comparative Example:

[0158] The comparative example uses a dome formed of conventional PEN material.

[0159] The spherical tops in the embodiments and the spherical tops in the comparative examples were tested respectively.

[0160] The test conditions are as follows:

[0161] The specific surface area of ​​the dome was tested using a surface area analyzer from Bester Company, and the specific surface area of ​​the sample was calculated using the BET method.

[0162] The gas permeability test of the dome is in accordance with GB / T 1038-2000, and each group of samples is tested 3 times and the average value is taken.

[0163] The water drop angle test on the dome is in accordance with GB / T 30693-2014, and each group of samples is tested 5 times to take the average value.

[0164] The pore size of the vent holes on the top surface of the ball was tested by SEM.

[0165] Table 3 Comparison of the physical properties of the dome in the embodiments and comparative examples:

[0166]

[0167]

[0168] It can be seen from Table 3 that the density of the dome of the embodiment is less than that of the dome of the comparative example. Thus, for domes of the same thickness and shape, the weight of the dome of the embodiment is lighter, which can further improve the mid-frequency sensitivity of the sound-generating device.

[0169] It can be seen from Table 3 that:

[0170] (1) The gas permeability of the dome of the embodiment is much greater than that of the dome made of conventional PEN material in the comparative example, which indicates that the gas permeability of the dome of the embodiment is very good.

[0171] (2) The dome of the embodiment has a large specific surface area and a highly porous interlaced network structure. During the vibration process, the open channels inside the dome can communicate with the outside world, so that the distortion of the dome is reduced.

[0172] (3) The water drop angle on the surface of the dome of the embodiment is significantly improved compared with that of the comparative example, which shows that the dome of the embodiment has better hydrophobicity.

[0173] The domes in the embodiment and the comparative example are respectively assembled into the same type of sound-generating device. For the convenience of description, the sound-generating device equipped with the dome in the embodiment is referred to as the sound-generating device in the embodiment, and the sound-generating device equipped with the dome in the comparative example is referred to as the sound-generating device in the comparative example. The total harmonic distortion (THD) test curves of the sound-generating device in the embodiment and the sound-generating device in the comparative example can be found in Figure 6 .from Figure 6 It can be seen that the sound-generating device in the embodiment has lower THD (total harmonic distortion) than the sound-generating device in the comparative example. This shows that the dome of the embodiment of the present invention has good air permeability, and during the vibration of the diaphragm, the opening channel inside the dome can be connected to the outside world through the air holes on the surface, and the sound quality and listening stability of the sound-generating device are better.

[0174] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0175] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A dome for a sound-generating device, It is characterized in that The dome includes an organic aerogel material having an open channel, so that the interior of the dome has an open channel extending in a thickness direction of the dome; The surface of the dome has air holes connected to the open hole channel, and the pore size of the air holes is 0.05 μm to 20 μm; The water drop angle range of the top surface of the ball is ≥80°; The gas permeability of the spherical top is 2.8×10 -3 cm 3 / cm 2 •s•Pa ~0.1cm 3 / cm 2 •s•Pa.

2. The dome according to claim 1, It is characterized in that The organic aerogel material includes at least one of polyimide, polyamide, polyester, aldehyde, polyolefin, polysaccharide and silicone.

3. The dome according to claim 1, It is characterized in that The main chain of the organic aerogel material contains an imide ring, and the imide ring is an aliphatic imide and / or an aromatic imide.

4. The dome according to claim 3, It is characterized in that The structure of the aliphatic imide comprises: 。 5. The dome according to claim 3, It is characterized in that The structure of the aromatic imide comprises: 。 6. The dome according to claim 3, It is characterized in that The dome further comprises a reinforcing material, which is reinforcing fibers and / or reinforcing particles.

7. The dome according to claim 6, It is characterized in that The mass percentage of the reinforcing material to the total weight of the dome is 0-80%.

8. The dome according to claim 6, It is characterized in that The reinforcing fiber is at least one of chopped fiber, continuous fiber, fabric and non-woven fabric; The reinforcing particles are at least one of inorganic particles of boron nitride, silicon carbide, carbon black, aluminum oxide and metal particles.

9. The dome according to claim 1, It is characterized in that The density of the dome is 0.05 g / cm 3 ~1g / cm 3 .

10. The dome according to claim 1, It is characterized in that The modulus of the dome is greater than 1 GPa; And / or, when the dome is deformed by 10%, the compression strength of the dome is 0.7 MPa~100 MPa.

11. The dome according to claim 1, It is characterized in that The thickness of the dome is 40 μm to 300 μm.

12. The dome according to claim 1, It is characterized in that The organic aerogel molecules in the spherical top have fluorine-containing groups.

13. A diaphragm assembly, used in a sound-generating device, It is characterized in that include: Diaphragm; as well as The dome according to any one of claims 1 to 12, wherein the dome is bonded to the diaphragm; Alternatively, the dome and the diaphragm are integrally injection molded.

14. A sound-generating device, It is characterized in that Comprising a diaphragm assembly according to claim 13.

15. An electronic device, It is characterized in that Comprising a sound generating device according to claim 14.

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