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

Abstract

The present invention discloses a dome, a diaphragm assembly, a sound-generating device and an electronic device for a sound-generating device; wherein, the dome of the sound-generating device comprises a core layer and two surface layers, and in the thickness direction of the core layer, the two surface layers are respectively located on both sides of the core layer; wherein, the core layer is made of at least an organic aerogel material, and the interior of the core layer has a porous structure, and the porous structure comprises pores, and the pore wall thickness of the pores is 1nm-0.1μm; the compression strength of the dome along its thickness direction is greater than 10MPa. According to the dome of the invention, the surface layer can be directly bonded and fixed by an organic aerogel layer, and the density of the organic aerogel layer is relatively small, thereby reducing the weight of the dome and improving the mid-frequency sensitivity. The organic aerogel layer has good temperature resistance, thereby ensuring the vibration consistency of the dome in a high temperature environment and avoiding the occurrence of separation vibration.

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 are required to have a thinner and lighter structure, further widen the high and low frequency range, and have good mid-frequency sensitivity and appropriate F0 and high frequency Fh (high frequency cutoff frequency).

[0003] Conventional composite dome structures are mostly aluminum foil + adhesive layer + foam + adhesive layer + aluminum foil. The adhesive layer is usually made of phenolic resin, silicone resin, epoxy resin, and the density is generally greater than 1.3g / cm 3 . For this type of dome structure, the glue layer will increase the thickness of the dome, increase the mass, and reduce the sensitivity. The glue layer is a resin material. The long-term use temperature of the resin material is generally less than 150°C. The temperature of the speaker can reach up to 140°C when it is working for a long time or under reliability conditions, which is close to the use limit of the resin material. The resin material will soften at high temperatures, resulting in a decrease in the modulus and strength of the dome, prone to split vibration, and a forward shift of the high-frequency cutoff frequency. In addition, the foam used in conventional dome structures is a homogeneous material with a low modulus-to-density ratio and a forward shift of the high-frequency cutoff frequency. Summary of the invention

[0004] The purpose 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 a core layer and two surface layers, wherein in a thickness direction of the core layer, the two surface layers are respectively located on both sides of the core layer;

[0006] Wherein, the core layer is at least made of organic aerogel material, the interior of the core layer has a porous structure, the porous structure includes pores, and the pore wall thickness of the pores is 1nm-1μm;

[0007] The compressive strength of the dome along the thickness direction thereof is greater than 10 MPa.

[0008] Optionally, the pore size of the pores is 5 nm to 500 μm.

[0009] Optionally, at room temperature, the peeling force between the core layer and the surface layer is greater than 200 g / 25 mm.

[0010] Optionally, the organic aerogel material includes at least one of polyimides, polyamides, polyesters, aldehydes, polyolefins and polysaccharides.

[0011] 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.

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

[0013]

[0014] Optionally, the structure of the aromatic imide comprises:

[0015]

[0016] Optionally, the thickness of the dome is 10 μm to 300 μm;

[0017] And / or, the ratio of the thickness of the core layer to the total thickness of the dome is 1 / 6 to 1 / 3.

[0018] Optionally, the bending modulus of the dome is 1.5 GPa to 20 GPa;

[0019] And / or, the modulus density ratio of the dome is 5 GPa.cm 3 / g~60GPa.cm 3 / g.

[0020] Optionally, the flexural modulus of the core layer is 30 MPa to 600 MPa;

[0021] And / or, the compression modulus of the core layer along its thickness direction is 30MPa to 600MPa;

[0022] And / or, the compression modulus of the core layer along a direction parallel to the surface layer is 30 MPa to 200 MPa.

[0023] Optionally, the core layer further includes a filler, and the filler includes at least one of a reinforcing material, a conductive material, and a thermal conductive material.

[0024] Optionally, the reinforcing material is reinforcing fibers and / or reinforcing particles;

[0025] The reinforcing fiber is at least one of chopped fiber, continuous fiber, fabric and non-woven fabric;

[0026] The reinforcing particles are at least one of inorganic particles of boron nitride, silicon carbide, carbon black, aluminum oxide and metal particles.

[0027] Optionally, the conductive material is at least one of carbon black, carbon fiber, flake graphite, metal particles, nickel-coated graphite powder, nickel-coated carbon fiber, carbon black, metal powder, metal foil and metal fiber.

[0028] Optionally, the thermally conductive material is a metal filler or an inorganic non-metal filler;

[0029] The metal filler includes at least one of aluminum, copper, silver, magnesium, tin, lead and iron;

[0030] The inorganic non-metal filler includes at least one of boron nitride, boron carbide, silicon carbide, aluminum oxide, graphite, carbon nanotubes, graphene and nano-carbon powder.

[0031] Optionally, the material of the surface layer is at least one of metal material, engineering plastic material and fiber material.

[0032] 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:

[0033] a diaphragm; and

[0034] The dome as described above, wherein the dome is bonded to the diaphragm;

[0035] Alternatively, the dome and the diaphragm are integrally injection molded.

[0036] 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.

[0037] 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.

[0038] According to the dome of the present invention, the dome is a composite structure, in which the core layer is an organic aerogel layer, and the two surface layers can be directly bonded and fixed by the organic aerogel layer, and the glue layer can be omitted. The density of the organic aerogel layer is relatively small, thereby reducing the weight of the dome and improving the mid-frequency sensitivity. The organic aerogel layer has good temperature resistance, thereby ensuring the vibration consistency of the dome in a high temperature environment and avoiding the sound of separated vibration. Through the above design, the dome has a higher modulus, which can improve the mechanical properties of the dome.

[0039] 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

[0040] 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.

[0041] Figure 1 This is one of the structural schematic diagrams of the dome provided by the embodiment of the present invention.

[0042] Figure 2This is the second structural schematic diagram of the dome provided by the embodiment of the present invention.

[0043] Figure 3 It is a schematic diagram of the structure of the organic aerogel material provided by an embodiment of the present invention.

[0044] Figure 4 This is the third structural schematic diagram of the dome provided by the embodiment of the present invention.

[0045] Figure 5 It is one of the structural schematic diagrams of the diaphragm assembly provided in an embodiment of the present invention.

[0046] Figure 6 This is the second structural schematic diagram of the diaphragm assembly provided in an embodiment of the present invention.

[0047] Figure 7 It is a comparison diagram of FR curves of the dome according to the embodiment of the present invention and the dome according to the comparative example.

[0048] Description of reference numerals:

[0049] 100, dome; 110, core layer; 111, pores; 120, surface layer; 200, diaphragm. DETAILED DESCRIPTION

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] See also Figures 1 to 4An embodiment of the present invention provides a dome 100 for a sound-generating device, the dome 100 comprising a core layer 110 and two surface layers 120, wherein in the thickness direction of the core layer 110, the two surface layers 120 are respectively located on both sides of the core layer 110; wherein the core layer 110 is made of at least an organic aerogel material, the interior of the core layer 110 has a porous structure, the porous structure comprises pores 111, and the pore wall thickness of the pores 111 is 1 nm to 1 μm; the compressive strength of the dome 100 along its thickness direction is greater than 10 MPa.

[0056] Optionally, the dome 100 may be a flat plate structure, such as Figure 1 shown.

[0057] 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.

[0058] The dome 100 of the present invention is a multi-layer structure. Figure 3 and Figure 4 The base material of the core layer 110 is an organic aerogel material, which can form an organic aerogel layer. The organic aerogel layer is located between the two surface layers 120, and the organic aerogel material is oriented along the thickness direction of the dome 100.

[0059] like Figure 4 As shown, the organic aerogel material can be arranged from one surface layer 120 to the other surface layer 120 between the two surface layers 120, so that the two surface layers 120 can be bonded and fixed by the core layer 110 made of organic aerogel material, thereby eliminating the need to set a glue layer between the surface layer 120 and the core layer 110. In this way, the thickness of the dome 100 can be reduced, so that the dome 100 can be made thinner and lighter.

[0060] It should be noted that, at present, the conventional composite structure ball top is mostly formed by bonding and fixing the aluminum foil layer on the two surfaces of the foam core layer through the adhesive layer, thereby forming an aluminum foil layer + adhesive layer + foam layer + adhesive layer + aluminum foil layer combination. The composite structure ball top formed in this way has a larger thickness due to the introduction of the adhesive layer.

[0061] Although the dome 100 of the present invention is a composite structure, Figure 4 As shown, however, the adhesive layer between the core layer 110 and the surface layer 120 is omitted, thereby reducing the overall thickness of the dome 100 and making the manufactured dome 100 thinner and lighter.

[0062] In the dome 100 of the present invention, the core layer 110 is made of organic aerogel material. Organic aerogel material is a solid material with large porosity and large specific surface area. Most of its volume is composed of air. The porosity is 30% to 98%, and its density is 0.03g / cm 3 ~1g / cm 3 , its density is small, and using organic aerogel material as the base material can make the dome lighter and have better mid-frequency sensitivity.

[0063] In the present invention, the organic aerogel material used to make the core layer 110 is a porous structure, which may include a plurality of pores 111, which may be formed as follows: Figure 3 In the honeycomb structure shown, the cell wall thickness of the cells 111 is 1 nm-1 μm.

[0064] Optionally, the wall thickness of the pores 111 may be 1 nm, 70 nm, 150 nm, 300 nm, 500 nm, 700 nm, 1 μm, etc.

[0065] It should be noted that the thickness of the cell wall of the pore 111 will affect the bending modulus of the organic aerogel material to a certain extent. The thicker the cell wall of the pore 111, the greater the bending modulus of the organic aerogel, and a larger bending modulus can prevent the ball top 100 from deforming during long-term vibration. On the other hand, the thicker the cell wall of the pore 111, the smaller the pore size of the pore 111.

[0066] The compressive strength of the dome 100 of the present invention along its thickness direction is greater than 10 MPa.

[0067] The compressive strength of the dome is related to its rigidity. The greater the compressive strength of the dome, the greater the rigidity of the dome.

[0068] In the present invention, the compression strength of the dome 100 is relatively large, and its compression strength is greater than or equal to 10 MPa, which can make the rigidity of the dome 100 relatively large, so that the sound-generating device using the dome 100 can have better high-frequency performance. For example, the compression strength of the dome 100 can be 12 MPa, 15 MPa, 20 MPa, 22 MPa, etc. When the compression strength of the composite dome structure of the present invention reaches 15 MPa to 20 MPa, its vibration stability performance is good, and the dome is not easy to deform in the case of high-frequency vibration. These performances are conducive to improving the high-frequency performance of the dome.

[0069] It should be noted that the composite structure of conventional domes is mostly aluminum foil layer + glue layer + foam layer + glue layer + aluminum foil layer, wherein the glue layer is usually made of resin materials such as phenolic resin, silicone resin, epoxy resin, etc., which makes the long-term use temperature range of the dome be between -50℃ and 250℃.

[0070] The dome 100 of the present invention is a composite structure, in which the core layer 110 uses an organic aerogel material as a substrate. The organic aerogel material can play a bonding role on the surface layer 120. Compared with the prior art, the dome 100 of the present invention does not need to be provided with a glue layer. Compared with the existing glue layer, the organic aerogel material can maintain good structural stability in a wider temperature range. This design can improve the temperature resistance of the dome 100. Utilizing the characteristics of the organic aerogel, the dome 100 of the present invention can work stably in the range of -80°C to 350°C for a long time. This obviously has a wider temperature use range than the composite dome using a glue layer, that is, the dome can be used for a long time in a lower or higher temperature environment.

[0071] The dome 100 according to the present invention is a composite structure, in which the core layer 110 is an organic aerogel layer, and the two surface layers 120 can be directly bonded and fixed by the organic aerogel layer, and the glue layer can be omitted. The density of the organic aerogel layer is relatively small, thereby reducing the weight of the dome 100 and improving the mid-frequency sensitivity. Moreover, the organic aerogel layer has good temperature resistance, thereby ensuring the vibration consistency of the dome 100 in a high temperature environment and avoiding the sound of separated vibration. In addition, through the above-mentioned setting, the dome 100 has a higher modulus, thereby improving the mechanical properties of the dome 100.

[0072] In some examples of the present invention, the organic aerogel material used to make the core layer 110 is a porous structure, and the porous structure includes a plurality of pores 111 , and the pore diameter of the pores 111 is 5 nm to 500 μm.

[0073] Optionally, the pores 111 have a pore size of 5 nm, 50 nm, 100 nm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 500 μm, etc. In a preferred embodiment, the pores 111 include a large number of pores with a pore size range of 50 nm to 150 nm, and a large number of pores with a pore size range of 10 μm to 100 μm. This pore size distribution can effectively reduce the mass of the core layer on the one hand, and on the other hand, can use fine pores to increase the compression modulus and bending modulus of the core layer as much as possible, thereby improving the overall structural strength of the dome.

[0074] In some examples of the present invention, the bending modulus of the dome 100 is 1.5 GPa to 20 GPa; and / or the modulus-to-density ratio of the dome 100 is 5 GPa.cm 3 / g~60GPa.cm 3 / g.

[0075] It is understandable that, during the operation of the sound-generating device, the stronger the anti-bending deformation capability of the dome 100 is, the less likely the dome 100 is to be deformed during the vibration process.

[0076] In the present invention, the core layer 110 made of organic aerogel material is combined with two surface layers 120, so that the bending modulus of the formed dome 100 can be greatly improved. For example, the bending modulus of the dome 100 can reach 1.5GPa to 20GPa, which can reduce the risk of deformation of the dome 100 during vibration, thereby avoiding the phenomenon of polarization of the sound device or split vibration under high-frequency vibration, thereby improving the sound performance of the sound device.

[0077] Optionally, the bending modulus of the dome 100 can be designed to be 1.5 GPa, 2 GPa, 6 GPa, 8 GPa, 10 GPa, 16 GPa, 20 GPa, etc.

[0078] Preferably, the bending modulus of the dome 100 may be 1.6 GPa to 19 GPa, so that the dome 100 is not easily deformed during long-term use, thereby increasing the service life of the dome and enabling the sound-generating device to have good sound-generating performance.

[0079] In an embodiment of the present invention, the modulus-to-density ratio of the dome 100 is 5 GPa.cm 3 / g~60GPa.cm 3 / g. Wherein, modulus-to-density ratio = modulus / density.

[0080] Optionally, the modulus-to-density ratio of the dome 100 is 5 GPa.cm 3 / g、10GPa.cm 3 / g, 15GPa.cm 3 / g, 20GPa.cm 3 / g、30GPa.cm 3 / g, 40GPa.cm 3 / g, 45GPa.cm 3 / g, 50GPa.cm 3 / g, 55GPa.cm 3 / g, 60GPa.cm 3 / g, etc.

[0081] The greater the modulus-density ratio of the dome 100, the greater the high-frequency cutoff frequency of the sound-generating device. 3 / g~60GPa.cm 3 / g can broaden the mid-frequency response of a sound-generating device, for example, and can obtain a clear response to the input signal over a wider frequency range.

[0082] In addition, the base material for making the dome 100 is an organic aerogel material, which has a network structure of many crisscross holes inside. The porous network structure makes the organic aerogel material have a low density characteristic compared to traditional dome materials, such as metal foil and engineering materials. Under the same size conditions, the organic aerogel material can minimize the mass of the dome, 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. The solution provided by the embodiment of the present invention can make the sound-generating device take into account both mid-frequency and high-frequency sensitivity.

[0083] In some examples of the present invention, Figure 3 As shown, the bending modulus of the core layer 110 is 30MPa-600MPa, the compression modulus of the core layer 110 along its thickness direction is 30MPa-600MPa; and / or the compression modulus of the core layer 110 along a direction parallel to the surface layer is 30MPa-200MPa.

[0084] In the present invention, the organic aerogel material used to make the dome 100 is arranged in a direction perpendicular to the surface of the dome 100 to form a network structure, so that the formed core layer 110 has a large bending modulus. At the same time, the core layer 110 has a large compression modulus along its own thickness direction and in a direction parallel to its own surface.

[0085] That is to say, the core layer 110 of the dome 100 of the present invention itself has a suitable bending modulus and compression modulus, which can reduce the risk of deformation of the core layer 110 during vibration, thereby avoiding the phenomenon of polarization of the dome or split vibration under high-frequency vibration, which is beneficial to improving the sound performance of the sound-generating device.

[0086] In some examples of the present invention, at room temperature, the peeling force between the core layer 110 and any of the surface layers 120 is greater than 200 g / 25 mm.

[0087] In the dome of the present invention, the core layer 110 is made of organic aerogel material, and the organic aerogel material has physical effects, chemical bonds, and micromechanical adhesion with the surface layer, which can play a role of adhesion. These characteristics allow the core layer 110 and the two surface layers 120 to be directly bonded and fixed without the need to introduce a separate adhesive layer between the core layer 110 and each surface layer 120. That is, although the dome 100 of the present invention is a composite structure, there is no need to set an adhesive layer, which can reduce the thickness of the dome 100. The aerogel material used in the present invention can make the formed dome 100 lighter and thinner while ensuring a strong bond with the surface layer 120.

[0088] In some examples of the present invention, the thickness of the dome 100 is 10 μm to 300 μm; and / or the ratio of the thickness of the core layer 110 to the total thickness of the dome 100 is 1 / 6 to 1 / 3.

[0089] For example, the thickness of the dome 100 may be 10 μm, 50 μm, 90 μm, 130 μm, 170 μm, 210 μm, 250 μm, 300 μm, etc., which is not limited in the embodiments of the present invention.

[0090] Preferably, the thickness of the dome 100 is 30 μm to 100 μm.

[0091] The thickness of the core layer 110 made of organic aerogel material accounts for 1 / 3 to 1 / 6 of the total thickness of the dome 100. When the thickness of the core layer 110 is thin, the weight reduction effect of the dome 100 is poor, and the sensitivity of the sound-generating device is reduced. When the thickness of the core layer 110 is thick, the rigidity of the entire dome 100 may be poor due to the insufficient rigidity of the core layer 110 compared to the surface layer 120, which may result in poor high frequency of the sound-generating device. Optionally, the ratio of the thickness of the core layer 110 to the total thickness of the dome 100 can be 1 / 6, 1 / 5, 1 / 4, 1 / 3, etc.

[0092] In some examples of the present invention, the base material of the core layer 110 of the dome 100 may be an organic aerogel material, and the organic aerogel material includes at least one of polyimides, polyamides, polyesters, aldehydes, polyolefins and polysaccharides.

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

[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, thereby forming a solid material with a nano-scale porous structure. This material is the organic aerogel material used in the present invention.

[0095] In the present invention, the organic aerogel may be made of a high molecular organic material, which is not only porous and lightweight, but also has a certain rigidity compared to inorganic aerogel materials. It can be used to prepare a dome, so that the dome has the characteristics of light weight and high strength, and can meet the strength, stiffness and damping performance required for 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 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] 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. 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.

[0103] Under the same size conditions, the polyimide organic aerogel material can reduce the mass of the dome 100 to the maximum extent, thereby achieving the effect of lowering the resonant frequency of the sound-generating device and improving the intermediate frequency sensitivity of the sound-generating device.

[0104] In addition, polyimide aerogel is a polymer containing an imide structure in the molecular chain segment, and has excellent high and low temperature resistance. In this way, when the operating temperature of the sound-generating device continues to rise, the dome 100 can still maintain a high modulus, avoiding the phenomenon of split vibration and high-frequency cutoff frequency shifting forward due to the decrease in the modulus of the dome caused by the increase in temperature. In addition, the dome 100 made of polyimide aerogel material is mechanically stable and has high chemical resistance, which effectively improves the use effect and service life of the sound-generating device.

[0105] 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, which is not limited in the present invention.

[0106] In addition, it should be noted that the use of organic aerogel material to make the dome 100 is based on the easy molding characteristics of the organic aerogel material, so that the molding process of the dome 100 is relatively simple, and the dome 100 can be made into a specific shape as needed, and the yield is high. Due to the simple process, the cost can be appropriately reduced, and the promotion and application of organic aerogel materials in sound-generating devices such as micro speakers and other products are expanded.

[0107] In some examples of the present invention, the core layer 110 of the dome 100 may further include a filler, and the filler includes at least one of a reinforcing material, a conductive material, and a thermal conductive material.

[0108] When the core layer 110 further includes a reinforcing material, the reinforcing material may 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.

[0109] It should be noted that the proportion of the reinforcing material in the core layer 110 can be 0, that is, the core layer 110 is entirely made of organic aerogel material. In addition, the proportion of the reinforcing material in the core layer 110 can be flexibly adjusted as needed, and the embodiment of the present invention does not limit this.

[0110] It should be noted that when reinforcing materials are added to the organic aerogel material, as the proportion of reinforcing materials in the organic aerogel material increases, the bending modulus and compressive strength of the formed dome 100 will show a trend of first increasing and then decreasing. This is because: as the proportion of reinforcing materials in the dome 100 increases, the reinforcing fiber reinforcement effect is obvious, so the bending modulus and compressive strength of the dome 100 are improved. When the proportion of reinforcing materials in the dome 100 is too large, the proportion of organic aerogel decreases, and the bonding effect of the aerogel is reduced, and it will become very fragile, and may even be unable to form. At this time, the bending modulus and compressive strength of the dome 100 will be low. Therefore, it is necessary to reasonably control the mass proportion of reinforcing materials in the dome 100.

[0111] In some examples of the present invention, the conductive material is at least one of carbon black, carbon fiber, flake graphite, metal particles, nickel-coated graphite powder, nickel-coated carbon fiber, carbon black, metal powder, metal foil and metal fiber. By adding conductive material to the organic aerogel material, the formed dome 100 can have a certain conductive property.

[0112] In some examples of the present invention, the thermally conductive material is a metal filler or an inorganic non-metal filler.

[0113] In the present invention, the base material of the core layer 110 is an organic aerogel material. The organic aerogel material has anisotropy, such as Figure 3 The organic aerogel material is oriented in a direction perpendicular to the surface of the spherical top. By adding a thermal conductive material to the organic aerogel material, the thermal conductive effect of the organic aerogel material can be increased, so that the formed spherical top has good thermal conductivity.

[0114] Optionally, the thermally conductive material may be a metal filler, and the metal filler includes at least one of aluminum, copper, silver, magnesium, tin, lead and iron.

[0115] That is, when forming the core layer 110 of the dome 100, a certain amount of metal filler can be added to the organic aerogel material, and the metal filler can be used as a thermal conductive material to improve the thermal conductivity of the core layer 110. The metal filler has a high thermal conductivity and can conduct heat through the movement of a large number of free electrons.

[0116] After adding at least one metal filler mentioned above to the organic aerogel material, the thermal conductivity of the material is significantly increased compared with the aerogel material without adding the metal filler.

[0117] That is to say, by adding one or more of the above-mentioned metal fillers as thermal conductive materials into the organic aerogel material and arranging the metal fillers along the orientation direction of the organic aerogel material, the thermal conductivity of the organic aerogel material can be significantly improved, and the dome can have the characteristic of high thermal conductivity.

[0118] In some examples of the present invention, the thermally conductive material may also be an inorganic non-metal filler, and the inorganic non-metal filler includes at least one of boron nitride, boron carbide, silicon carbide, aluminum oxide, graphite, carbon nanotubes, graphene and nano-carbon powder.

[0119] That is to say, the thermal conductive material is not limited to the above-mentioned metal filler, and the thermal conductive material can also be selected from inorganic non-metal fillers. The above-mentioned various inorganic non-metal fillers have high thermal conductivity and excellent heat resistance and thermal conductivity. When they are added as fillers to the organic aerogel to form the core layer 110, the ball top 100 can have the characteristic of high thermal conductivity.

[0120] In addition, in the present invention, one or more of a reinforcing material, a conductive material, and a thermal conductive material may be added to the core layer 110 of the dome 100. In some examples of the present invention, the material of the two surface layers 120 of the dome 100 may be at least one of a metal material, an engineering plastic material, and a fiber material. The surface layer 120 is preferably made of aluminum foil. The material of the two surface layers 120 may be the same.

[0121] The present invention also provides a method for preparing a dome, comprising the following steps:

[0122] Step S1, selecting dianhydride and diamine monomers, crosslinking agents, dispersants and other auxiliary agents to polymerize in a certain proportion to obtain a polyamic acid salt hydrogel, wherein the solid content of the polyimide wet gel is 3% to 40%.

[0123] Optionally, the molar ratio of the dianhydride monomer to the diamine monomer is (1-1.2):1.

[0124] 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.

[0125] 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.

[0126] Step S2, spraying or coating the polyimide wet gel obtained in step S1 on the surface of one surface layer 120, and then compounding the other surface layer 120 with the polyimide wet gel to obtain a composite structure.

[0127] Step S3, freeze-drying the composite structure obtained in step S2, and subjecting it to a thermal amination process after shaping, to finally obtain a spherical top 100 containing polyimide aerogel. The spherical top 100 has a core layer 110 of polyimide aerogel and two surface layers 120 composited on both sides of the core layer 110.

[0128] The freeze drying conditions are: temperature ≤ 15°C, vacuum degree ≤ 500Pa, and time 0.5h to 10h. The thermal imidization conditions are: temperature 250°C to 350°C, and time 0.5h to 1.5h.

[0129] 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 5 and 6 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.

[0130] 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 200 and the diaphragm 100 is not less than 1 mm, which can improve the bonding strength between the dome and the diaphragm.

[0131] 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.

[0132] The diaphragm 200 may be made of engineering plastics, for example.

[0133] The engineering plastics include, for example, polyetheretherketone (PEEK), PAR, and the like.

[0134] The diaphragm 200 may also be made of an elastomeric material.

[0135] The elastomeric material includes, for example, thermoplastic polyurethane elastomer (TPU), thermoplastic polyester elastomer (TPEE), rubber, and the like.

[0136] In addition, the diaphragm 200 may also be made of adhesive film.

[0137] The adhesive film includes, for example, acrylic adhesive, silicone adhesive, etc.

[0138] 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.

[0139] In the present invention, the thickness of the diaphragm 200 can be designed to be between 0.01 mm and 0.5 mm. Within this thickness range, the diaphragm can be suitable for use in the vibration space of most sound-generating devices.

[0140] For example, the thickness of the diaphragm 200 is 0.01 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc., which is not limited in the embodiment of the present invention.

[0141] The dome 100 of the present invention is a composite structure, using an organic aerogel material as the core layer 110, and the surface layer 120 can be directly bonded to both sides of the core layer 110, thereby eliminating the glue layer connecting the core layer 110 and the surface layer 120, making the dome 100 lighter and having better mid-frequency sensitivity. At the same time, the dome 100 also has excellent high and low temperature resistance. When the sound-generating device is working for a long time, the temperature inside it will continue to rise, but the dome 100 of the present invention can maintain a high strength at a long-term high temperature, avoiding the split vibration caused by the reduction of the modulus of the dome and the phenomenon of the high-frequency cutoff frequency moving forward.

[0142] An embodiment of the present invention further provides a sound-generating device, which includes the above-mentioned diaphragm assembly.

[0143] The sound generating device provided by the embodiment of the present invention can be used in various electronic devices.

[0144] An embodiment of the present invention further provides an electronic device, which includes the sound-generating device as described above.

[0145] 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.

[0146] 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.

[0147] Figure 4 The dome of the embodiment is shown. The dome 100 includes a core layer 110 and two surface layers 120 arranged on both sides of the core layer 110. The core layer 110 is made of organic aerogel material, and the surface layer 120 is made of aluminum foil. The dome in the comparative example includes a foam layer and an aluminum foil layer bonded to both sides of the foam layer by an adhesive layer. The domes in the embodiment and the comparative example have the same thickness, and the thickness of the core layer 110 in the embodiment is the same as the thickness of the foam layer + two adhesive layers in the comparative example, and the thickness of the surface layer 120 in the embodiment is the same as the thickness of the aluminum foil layer in the comparative example.

[0148] Example:

[0149] The method for making the dome in the embodiment is as follows:

[0150] Step S1, dissolving 180.22g (0.9mol) of 4,4-diaminodiphenyl ether in 1L of N-methylpyrrolidone, adding 294g (1mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride under stirring, wherein 3,3',4,4'-biphenyltetracarboxylic acid dianhydride is added in small amounts and multiple times, for example; polymerizing the formed mixture in an ice-water bath for about 5h to obtain a polymerized reactant, adding 8g (0.02mol) of 1,3,5-(triaminophenoxy)benzene cross-linking agent to the obtained polymerized reactant to obtain a polyamic acid salt solution; slowly pouring the obtained polyamic acid salt solution into acetone, and the precipitated filaments obtained by precipitation are polyimide materials, and the polyimide materials are dried to constant weight.

[0151] Step S2, taking 50g of polyamic acid salt to prepare a polyamic acid gel with a mass fraction (solid content) of 15%, heating the polyamic acid gel to 60°C, and then spraying it onto a surface of a surface layer 120 and then compounding a layer of surface layer 120 to form a composite structure; wherein the surface layer 120 is aluminum foil.

[0152] Step S3, freezing the composite structure prepared in step S3 at -40°C for 1 hour, drying it at a vacuum degree of <100Pa for 2 hours, and then thermally imidizing it at 150°C for 1 hour, and then thermally imidizing it at 300°C for 2 hours, to obtain the organic aerogel dome 100 for a sound-generating device provided by the present invention.

[0153] Comparative Example:

[0154] The two surfaces of the foam layer are respectively bonded to aluminum foil via adhesive layers, and then hot-pressed at 140° C., wherein the adhesive layers are phenolic resin.

[0155] The following Table 1 compares the performance indicators of the domes in the embodiment and the comparative example.

[0156] Table 1 Comparison of performance indicators between the embodiments and the comparative examples

[0157] Material Example Comparative Example Dome thickness / μm 150 150 Ball top mass / mg 22.4 32.5 Aluminum foil thickness / μm 10 10 Aerogel thickness / μm 130 / Glue layer + foam + glue layer thickness / μm / 130 Bending modulus of dome / GPa 12.3 10.2 <![CDATA[Modulus density ratio of the dome top / GPa.cm 3 / g]]> 33.9 19.4 Destruction temperature / ℃ 320 200

[0158] According to Table 1 above, the following conclusions can be drawn:

[0159] First, performance index comparison:

[0160] (1) Compared with the dome of the comparative example, the dome of the embodiment has the smallest mass when the thickness of the aluminum foil layer of the two is the same.

[0161] (2) Compared with the dome of the comparative example, the dome of the embodiment uses polyimide aerogel of the same thickness to replace the adhesive layer + foam layer + adhesive layer in the comparative example, which can reduce the mass of the dome by 10.1 mg, increase the bending modulus by 2.1 GPa, and increase the modulus-to-density ratio by 14.5 GPa.cm 3 / g, and has good intermediate frequency sensitivity.

[0162] (3) The dome of the embodiment, wherein the polyimide aerogel is a polymer containing an imide structure in the molecular chain segment, has excellent high and low temperature resistance, and a long-term use temperature of -80 to 350°C. The dome of the comparative example is made of aluminum foil + adhesive layer + foam layer + adhesive layer + aluminum foil, wherein the adhesive layer is made of phenolic resin, and the long-term use temperature is -50 to 200°C. When the speaker is working for a long time, the temperature continues to rise. The dome of the embodiment can maintain a high strength, avoiding the phenomenon of split vibration caused by the reduction of the modulus of the dome and the forward shift of the high-frequency cutoff frequency.

[0163] Second, frequency response curve comparison:

[0164] The dome of the embodiment and the dome of the comparative example are assembled with a folding ring made of polyurethane film into a diaphragm assembly, and are respectively assembled into sound-generating devices of the same model, such as Figure 7 As shown, the frequency response curves of the two are as follows:

[0165] from Figure 7 It can be seen that the sensitivity of the sound-generating device using the dome of the embodiment is about 2dB higher than that of the dome of the comparative example after 700Hz. When the sound-generating device works for a long time, the temperature continues to rise. The dome of the embodiment can maintain a high strength, avoiding the phenomenon of split vibration caused by the reduction of the modulus of the dome and the forward shift of the high-frequency cutoff frequency.

[0166] 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.

[0167] 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, characterized in that: The dome comprises a core layer and two surface layers, and in the thickness direction of the core layer, the two surface layers are respectively located on both sides of the core layer; Wherein, the core layer is at least made of organic aerogel material, the interior of the core layer has a porous structure, the porous structure includes pores, and the pore wall thickness of the pores is 1nm-1μm; The compressive strength of the dome along the thickness direction is greater than 10 MPa, the bending modulus of the dome is 1.5 GPa to 20 GPa, and the bending modulus of the core layer is 30 MPa to 600 MPa.

2. The dome according to claim 1, characterized in that: The pore diameter of the pores is 5 nm to 500 μm.

3. The dome according to claim 1, characterized in that: At room temperature, the peeling force between the core layer and the surface layer is greater than 200 g / 25 mm.

4. The dome according to claim 1, characterized in that: The organic aerogel material includes at least one of polyimides, polyamides, polyesters, aldehydes, polyolefins and polysaccharides.

5. The dome according to claim 1, 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.

6. The dome according to claim 5, characterized in that: The structure of the aliphatic imide comprises:

7. The dome according to claim 5, characterized in that: The structure of the aromatic imide comprises:

8. The dome according to claim 1, characterized in that: The thickness of the dome is 10 μm to 300 μm; And / or, the ratio of the thickness of the core layer to the total thickness of the dome is 1 / 6 to 1 / 3.

9. The dome according to claim 1, characterized in that: The modulus-to-density ratio of the dome is 5 GPa.cm 3 / g~60GPa.cm 3 / g.

10. The dome according to claim 1, characterized in that: The compression modulus of the core layer along its thickness direction is 30MPa to 600MPa; And / or, the compression modulus of the core layer along a direction parallel to the surface layer is 30 MPa to 200 MPa.

11. The dome according to claim 1, characterized in that: The core layer further includes a filler, and the filler includes at least one of a reinforcing material, a conductive material, and a thermal conductive material.

12. The dome according to claim 11, characterized in that: The reinforcing material is reinforcing fibers and / or reinforcing particles; 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.

13. The dome according to claim 11, characterized in that: The conductive material is at least one of carbon black, carbon fiber, flake graphite, metal particles, nickel-coated graphite powder, nickel-coated carbon fiber, carbon black, metal powder, metal foil and metal fiber.

14. The dome according to claim 11, characterized in that: The thermally conductive material is a metal filler or an inorganic non-metal filler; The metal filler includes at least one of aluminum, copper, silver, magnesium, tin, lead and iron; The inorganic non-metal filler includes at least one of boron nitride, boron carbide, silicon carbide, aluminum oxide, graphite, carbon nanotubes, graphene and nano-carbon powder.

15. The dome according to claim 1, characterized in that: The material of the surface layer is at least one of metal material, engineering plastic material and fiber material.

16. A diaphragm assembly, used in a sound-generating device, characterized in that: include: Diaphragm; as well as According to any one of claims 1-15, the dome is adhesively connected to the diaphragm or is integrally injection molded.

17. A sound-generating device, characterized in that: Comprising a diaphragm assembly according to claim 16.

18. An electronic device, characterized in that: Comprising a sound emitting device according to claim 17.

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