Diaphragm, sound production device and electronic equipment

Abstract

The application discloses a vibrating diaphragm, a sound generating device and electronic equipment, and the vibrating diaphragm comprises a main body part and a conductive part, wherein the main body part is formed as a multilayer composite structure, the main body part comprises a thermoplastic material layer and a rubber material layer which are arranged in a stack, and the outermost side of the main body part is provided with the thermoplastic material layer; the conductive part is arranged on the thermoplastic material layer at the outermost side of the main body part, at least a part of the conductive part is exposed to the thermoplastic material layer to be electrically connected with a voice coil and an external circuit, the conductive part comprises a base and conductive particles dispersed in the base, and the base is composed of a heterochain polymer with a -NH-COO- characteristic group. The main body part of the vibrating diaphragm is a composite material composed of a thermoplastic material and a rubber material, so that the vibrating diaphragm can well balance rigidity and elasticity, especially for some sound generating devices with high F0 requirements, the application can better realize the ultrathin design of the vibrating diaphragm and improve the mid-frequency sensitivity. Meanwhile, the conductive part is arranged on the surface of the thermoplastic material layer, so that the resistance stability of the vibrating diaphragm is better.

Description

Technical Field

[0001] This invention relates to the field of electroacoustic technology, and more specifically, to a diaphragm for a sound-generating device, a sound-generating device using the diaphragm, and an electronic device using the sound-generating device. Background Technology

[0002] A sound-generating device generally includes a diaphragm, a voice coil attached to one side of the diaphragm, and electrical connectors that connect the internal and external circuitry of the device. The voice coil consists of two leads, which are electrically connected to two pads on the electrical connectors via spot welding or other methods. These connectors are also electrically connected to the external circuitry, allowing the electrical signals in the voice coil to be controlled by the electrical signals from the terminal product. Typically, the voice coil leads need to extend a certain length and remain suspended before connecting to the electrical connectors. While this suspended lead structure allows for higher sensitivity, the amplitude of the voice coil cannot be too large due to the limitation of the suspended leads, and the risk of breakage is higher. Low-frequency performance is also less pronounced, ultimately failing to provide a better listening experience for the user.

[0003] In some existing products, sound-generating devices also include a centering bracket, which is typically integrated into one side of the diaphragm. The centering bracket serves as an electrical connector between the voice coil and the external circuitry. Specifically, the voice coil's connecting wires are connected to the centering bracket, which in turn is connected to the external circuitry, thus achieving the electrical connection. While the application of a centering bracket effectively solves the problem of broken voice coil leads, its presence occupies internal space in the sound-generating device, thereby compromising the product's acoustic performance to some extent and ultimately reducing the user's audio experience.

[0004] To address the aforementioned issues, a conductive diaphragm has been proposed in related technologies. This conductive diaphragm possesses electrical conductivity, enabling electrical connection between the voice coil and external circuitry. However, to meet structural strength requirements, this conductive diaphragm requires a significant thickness, thus occupying vibration space. Furthermore, the conductive diaphragm exhibits poor vibration uniformity, negatively impacting sound quality. Summary of the Invention

[0005] One object of the present invention is to provide a diaphragm that can solve the technical problems in the prior art that cannot simultaneously meet the requirements of diaphragm weight, space, resilience and rigidity.

[0006] Another object of the present invention is to provide a sound-generating device composed of the above-described diaphragm.

[0007] Another object of the present invention is to provide an electronic device comprising the above-described sound-generating device.

[0008] To achieve the above objectives, the present invention provides the following technical solutions.

[0009] According to a first aspect of the present invention, a diaphragm includes a main body and a conductive portion, wherein the main body is formed as a multilayer composite structure, the main body includes a thermoplastic material layer and a rubber material layer stacked together, and the thermoplastic material layer is disposed on the outermost side of the main body, the conductive portion is disposed on the outermost side of the thermoplastic material layer of the main body, at least a portion of the conductive portion is exposed outside the thermoplastic material layer for electrical connection with a voice coil and an external circuit, the conductive portion includes a matrix and conductive particles dispersed in the matrix, the matrix being composed of a heterochain polymer having -NH-COO- characteristic groups.

[0010] The diaphragm according to embodiments of the present invention not only achieves electrical connection between the voice coil and external circuitry, but also avoids the problems of internal space loss and easy breakage and polarization of leads caused by connecting components such as centering supports. Furthermore, the main body of the diaphragm provided by the present invention is a composite material composed of thermoplastic and rubber materials, allowing the diaphragm to effectively balance rigidity and elasticity. Especially for some sound-generating devices with high F0 requirements, the present invention can better achieve ultra-thin diaphragm design and improve mid-frequency sensitivity. Simultaneously, placing the conductive part on the surface of the thermoplastic material layer can further enhance the diaphragm's resistance stability.

[0011] According to some embodiments of the present invention, the portion of the main body that is directly opposite the conductive portion and the conductive portion are together formed into a composite portion, and the elongation at break of the composite portion is greater than 30%.

[0012] According to some embodiments of the present invention, the resistance change of the conductive part is less than 0.5Ω after 500 hours in an environment with a relative humidity of 85% and a temperature of 85°C.

[0013] According to some embodiments of the present invention, the heterochain polymer of the conductive part comprises at least one of polyurethane, polyurethane acrylate copolymer, epoxy-modified polyurethane, and polyurethane-modified epoxy resin.

[0014] According to some embodiments of the present invention, the rubber material layer of the main body comprises at least one of nitrile rubber, hydrogenated nitrile rubber, acrylate rubber, polyurethane rubber, ethylene acrylate rubber, ethylene propylene diene monomer (EPDM) rubber, fluororubber, and silicone rubber.

[0015] According to some embodiments of the present invention, the thermoplastic material layer of the main body comprises at least one of thermoplastic polyurethane, thermoplastic polyester elastomer, thermoplastic polyimide material, polyether ether copper, thermoplastic polyester material, polyarylate, and polyetherimide.

[0016] According to some embodiments of the present invention, the thickness of the thermoplastic material layer is less than the thickness of the rubber material layer.

[0017] According to some embodiments of the present invention, the thickness of the diaphragm is 20 μm to 150 μm, and the thickness of the conductive part is 0.5 μm to 35 μm.

[0018] According to some embodiments of the present invention, the particle size of the conductive particles is not greater than 20 μm; and / or, the conductive particles include at least one of metal particles and carbon-containing particles.

[0019] According to some embodiments of the present invention, the content of the conductive particles in the conductive part is not less than 50% wt and not more than 95% wt.

[0020] According to some embodiments of the present invention, a portion of the conductive part is embedded in the main body; or, the conductive part is disposed on the outer surface of the main body.

[0021] According to some embodiments of the present invention, there are multiple conductive parts, which are spaced apart and located on the same side or opposite sides of the main body.

[0022] According to some embodiments of the present invention, the main body includes a folded ring portion, an outer edge portion disposed on the outer side of the folded ring portion, and an inner edge portion disposed on the inner side of the folded ring portion, and the conductive portion is disposed on the folded ring portion, the inner edge portion, and the outer edge portion.

[0023] According to some embodiments of the present invention, the conductive portion includes a first electrical connection portion located at the inner edge portion, a second electrical connection portion located at the outer edge portion, and a third electrical connection portion disposed at the folded ring portion. The first electrical connection portion is electrically connected to the voice coil, the second electrical connection portion is electrically connected to the external circuit, and the first electrical connection portion, the second electrical connection portion, and the third electrical connection portion are all exposed on the outer surface of the main body portion.

[0024] According to some embodiments of the present invention, the diaphragm further includes a damping layer, the damping layer being located between the thermoplastic material layer and the rubber material layer, the damping layer comprising at least one of acrylate pressure-sensitive adhesive, silicone pressure-sensitive adhesive, and polyurethane.

[0025] The sound-generating device according to a second aspect of the present invention includes the diaphragm described in any of the above embodiments.

[0026] An electronic device according to a third aspect of the present invention includes the sound-generating device described in the above embodiments.

[0027] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0029] Figure 1 This is a partial cross-sectional view of a diaphragm according to an embodiment of the present invention;

[0030] Figure 2 This is a partial cross-sectional view of a diaphragm according to yet another embodiment of the present invention;

[0031] Figure 3 This is a top view of a sound-generating device according to an embodiment of the present invention;

[0032] Figure 4 This is a three-dimensional structural diagram of a sound-generating device according to an embodiment of the present invention;

[0033] Figure 5 This is a partial cross-sectional view of a sound-generating device according to an embodiment of the present invention;

[0034] Figure 6 This is a partial cross-sectional view of a sound-generating device according to yet another embodiment of the present invention;

[0035] Figure 7 This is a comparison graph of the frequency response curves of Embodiment 1, Embodiment 2 and the comparative example of the present invention.

[0036] Figure Labels

[0037] Diaphragm 10; Main body 11; Folded ring 111; Outer edge 112; Inner edge 113; Thermoplastic material layer 114a; Rubber material layer 114b; Damping layer 115;

[0038] Conductive part 12; Substrate 121; Conductive particles 122;

[0039] Voice coil 20; first diaphragm 21; second diaphragm 22. Detailed Implementation

[0040] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0041] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0042] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0043] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0045] The diaphragm 10 according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0046] like Figure 1 and Figure 2 As shown, the diaphragm 10 according to an embodiment of the present invention includes a main body 11 and a conductive part 12. The main body 11 is formed as a multilayer composite structure. The main body 11 includes a thermoplastic material layer 114a and a rubber material layer 114b stacked together. The thermoplastic material layer 114a is provided on the outermost side of the main body 11. The conductive part 12 is provided on the outermost thermoplastic material layer 114a of the main body 11. At least a portion of the conductive part 12 is exposed outside the thermoplastic material layer 114a to be electrically connected to the voice coil 20 and the external circuit. The conductive part 12 includes a matrix 121 and conductive particles 122 dispersed in the matrix 121. The matrix 121 is composed of a heterochain polymer with -NH-COO- characteristic groups.

[0047] In other words, the diaphragm 10 according to the embodiment of the present invention is mainly composed of a main body 11 and a conductive part 12, wherein the main body 11 can serve as the main structure, and the main body 11 is a composite layer formed by a thermoplastic material layer 114a and a rubber material layer 114b.

[0048] Compared to conventional thermoplastic materials (such as PEEK, TPU, TPEE, etc.), rubber has better temperature resistance and a lower modulus. In other words, rubber not only has good high temperature resistance, weather resistance and high elasticity, but also has a relatively low modulus, which can achieve large vibration displacement. Therefore, the inclusion of a rubber material layer 114b in the main body 11 can enable the diaphragm 10 to achieve higher loudness, which can meet the requirements of high power and high temperature resistance of the sound-generating device, and make the sound-generating device have higher loudness, sensitivity and waterproof effect.

[0049] Furthermore, since thermoplastic materials have a relatively high modulus compared to rubber materials, and their stiffness and strength are superior, the thickness of thermoplastic materials can be thinner to achieve the same compliance. Therefore, by using thermoplastic materials, the thickness of the diaphragm 10 can be reduced, thus lightening its weight. Moreover, while reducing the thickness of the diaphragm 10, it also achieves high rigidity and high elasticity.

[0050] Therefore, the multi-layer composite design using thermoplastic material layer 114a and rubber material layer 114b can effectively balance stiffness, strength, and elasticity, and compared to pure rubber material, it has a thinner thickness and lighter weight. In other words, using a multi-layer composite of thermoplastic material layer 114a and rubber material layer 114b allows for a thinner diaphragm, thereby increasing the design space of the magnetic circuit and the vibration space. Furthermore, it also allows for a smaller diaphragm mass, higher mid-frequency sensitivity, and a louder sound output for the device.

[0051] Specifically, a thermoplastic material layer 114a is provided on the outermost side of the main body 11, and a conductive part 12 is provided on the outermost thermoplastic material layer 114a of the main body 11. At least a portion of the conductive part 12 is exposed on the thermoplastic material layer 114a to be electrically connected to the voice coil 20 and the external circuit. That is, at least one surface of the conductive part 12 is exposed on the first side surface of the main body 11 to be electrically connected to the voice coil 20 and the external circuit. The main body 11 of the diaphragm is a multilayer composite material of thermoplastic material layer 114a and rubber material layer 114b, and the conductive part 12 is located on the thermoplastic material layer 114a.

[0052] It should be noted that, in order to obtain the required strength and processing performance, some additives are added to the rubber material in addition to the base rubber. After the rubber material is vulcanized, some small molecules will be precipitated. The presence of the thermoplastic material layer 114a can reduce the influence of the precipitates on the resistance of the conductive part 12. Therefore, by directly placing the conductive part 12 in the thermoplastic material layer 114a, the stability of the resistance of the diaphragm 10 product can be increased.

[0053] In other words, by placing the thermoplastic material layer 114a between the rubber material layer 114b and the conductive part 12, the thermoplastic material layer 114a can act as a barrier, effectively reducing the influence of the precipitates after the rubber material is vulcanized on the resistance. The diaphragm 10 has a low resistance change rate after the damp heat reliability test.

[0054] Furthermore, by exposing at least a portion of the surface of the conductive part 12 to the surface of the main body 11 and electrically connecting it to the voice coil 20 and external circuitry, problems such as loss of internal vibration space caused by connecting components like the centering support and easy breakage of the voice coil 20 leads in the prior art can be solved. It also offers the advantage of simple circuit connection operation. Simultaneously, the presence of the substrate 121 of the conductive part 12 can protect the conductive particles 122 to a certain extent, giving the conductive part 12 superior oxidation resistance and corrosion resistance.

[0055] It should be noted that the conductive part 12 includes a matrix 121 and conductive particles 122 dispersed within the matrix 121. That is, the conductive part 12 includes a heterochain polymer with -NH-COO- characteristic groups and conductive particles 122.

[0056] Furthermore, the present invention obtains the conductive part 12 by combining the substrate 121 and conductive particles 122. Compared with pure conductors or surface coatings or plating, the thermoplastic material of the substrate 121 and the main body 11 has a strong bonding ability, which is beneficial to the vibration consistency of the diaphragm 10 during operation.

[0057] Furthermore, the substrate 121 of the conductive part 12 can serve as a binder between the conductive particles 122. The substrate 121 contains a heterochain polymer with -NH-COO- characteristic groups. Because the main chain of the heterochain polymer contains atoms other than carbon atoms, the material of the conductive part 12 has relatively high polarity and relatively good toughness. The heterochain polymer in the conductive part 12 is selected with -NH-COO- characteristic groups because -NH-COO- characteristic groups have strong polarity, which can enhance the bonding force between the heterochain polymer and the conductive particles 122. The resulting diaphragm 10 has higher flexibility and better vibration consistency, which can meet the requirements of large displacement, high loudness, and high sensitivity of the sound-generating device.

[0058] In other words, the substrate 121 in the conductive part 12 uses a heterochain polymer with -NH-COO- characteristic groups, which can achieve a better bonding effect between the substrate 121 and the conductive particles 122 in the conductive part 12, increase the interaction force between the substrate 121 and the conductive particles 122, and ensure consistency and conductivity stability during vibration. Specifically, when the diaphragm 10 vibrates at a high temperature, since the substrate 121 of the conductive part 12 contains a heterochain polymer with -NH-COO- characteristic groups, the heterochain polymer in the substrate 121 can act as a good link, connecting the conductive particles 122 into one, thereby achieving a uniform arrangement of the conductive particles 122, while ensuring the conductivity consistency and stability of the conductive part 12.

[0059] Furthermore, by employing the polar group -NH-COO-, the conductive part 12 can be cured at low temperatures, thereby reducing the impact on the thermoplastic material during the curing process and lowering the risk of deformation of the diaphragm 10. At the same time, the presence of the polar group is more conducive to the bonding force between the conductive part 12 and the main body 11, making it easier to achieve vibration consistency of the diaphragm.

[0060] In other words, the thermoplastic material in the diaphragm 10 according to the embodiments of the present invention has the effects of thinning, increasing adhesion, and blocking. The diaphragm 10 of the present invention can be applied to sound-generating device products with limited mass or thickness of the vibration system. It can not only meet the requirements of weight and space, but also ensure that the product has good resilience and rigidity. In addition, by adding thermoplastic material between the rubber material and the conductive part 12, the present invention increases the bonding force between the conductive part 12 and the main body 11, and reduces the impact of rubber material additives precipitation on the resistance of the conductive part 12.

[0061] Therefore, the diaphragm according to the embodiments of the present invention not only realizes the electrical connection between the voice coil and the external circuit, but also avoids the problems of internal space loss and easy breakage and polarization of leads caused by connecting parts such as centering supports. Furthermore, the main body of the diaphragm provided by the present invention is a composite material composed of thermoplastic and rubber materials, which allows the diaphragm to effectively balance rigidity and elasticity. Especially for some sound-generating devices with high F0 requirements, the present invention can better achieve ultra-thin diaphragm design and improve mid-frequency sensitivity. At the same time, placing the conductive part on the surface of the thermoplastic material layer can make the resistance stability of the diaphragm better.

[0062] According to one embodiment of the present invention, the portion of the main body 11 opposite to the conductive portion 12 and the conductive portion 12 are together formed into a composite portion, and the elongation at break of the composite portion is greater than 30%.

[0063] In other words, the orthographic projection area of ​​the conductive part 12 on the main body 11 is defined as the first region. A portion of the first region on the main body 11 and the conductive part 12 form a composite part. The elongation at break of the composite part is greater than 30%, that is, after the composite part is stretched by 30% strain, neither the conductive part 12 nor the main body 11 shows any signs of breakage.

[0064] It should be noted that when the elongation at break of the composite part is less than 30%, the diaphragm product may rupture during prolonged large-displacement vibration. Therefore, in this embodiment, by controlling the elongation at break of the composite part to be greater than 30%, for example, 35%, 40%, 45%, 50%, 60%, etc., it is possible to ensure that even if a 30% strain occurs when the diaphragm 10 vibrates, the conductive part 12 of the composite part will not crack or break.

[0065] In some specific embodiments of the present invention, the resistance change of the conductive part 12 after 500 hours in an environment with a relative humidity of 85% and a temperature of 85°C is less than 0.5Ω. That is, due to the protective effect of the thermoplastic material layer 114a, the resistance change of the conductive part 12 after 500 hours of high-temperature and high-humidity reliability testing (85% RH, 85°C) is less than 0.5Ω. Since a lower resistance change rate indicates better vibration stability of the diaphragm product, if the resistance change of the diaphragm product after reliability testing exceeds 0.5Ω, it indicates that the conductive part 12 may be at risk of cracking or detachment. Therefore, in this embodiment, by controlling the resistance change of the conductive part 12 to be less than 0.5Ω after 500 hours in an environment with a relative humidity of 85% and a temperature of 85°C, the high-temperature stability of the diaphragm 10 can be ensured.

[0066] According to one embodiment of the present invention, the heterochain polymer of the conductive portion 12 includes at least one of polyurethane, polyurethane acrylate copolymer, epoxy-modified polyurethane, and polyurethane-modified epoxy resin. In this embodiment, by employing the conductive portion 12 including the above-mentioned heterochain polymer, it is beneficial to have a stronger bonding force between the conductive portion 12 and the main body portion 11, thereby achieving vibration consistency of the diaphragm 10 during the vibration process.

[0067] In some specific embodiments of the present invention, the rubber material layer 114b of the main body 11 includes at least one of nitrile rubber, hydrogenated nitrile rubber, acrylate rubber, polyurethane rubber, ethylene acrylate rubber, EPDM rubber, fluororubber, silicone rubber, and fluorosilicone rubber. In this embodiment, the rubber material is a carbon chain polymer. The use of a carbon chain polymer in the main body 11 can achieve good adhesion to the heterochain polymer in the conductive part 12, ensuring the adhesion of the conductive part 12, thereby achieving vibration consistency of the diaphragm 10 during vibration and the reliability of the diaphragm 10 product.

[0068] According to one embodiment of the present invention, the thermoplastic material layer 114a of the main body 11 comprises at least one selected from thermoplastic polyurethane, thermoplastic polyester elastomer, thermoplastic polyimide material, polyether ether copper, thermoplastic polyester material, polyarylate, and polyetherimide. It should be noted that the polar groups of the above-mentioned thermoplastic materials have high reactivity, which is beneficial for low-temperature curing. Furthermore, the above-mentioned thermoplastic materials mainly contain polar groups, resulting in stronger intermolecular affinity and thus superior bonding strength.

[0069] In some specific embodiments of the present invention, the thickness of the thermoplastic material layer 114a is less than the thickness of the rubber material layer 114b. By controlling the thickness of the thermoplastic material layer to be less than the thickness of the rubber material layer, it is beneficial to achieve good rigidity, resilience and strength of the diaphragm 10.

[0070] According to one embodiment of the present invention, the thickness of the diaphragm 10 is 20 μm to 150 μm, and the thickness of the conductive portion 12 is 0.5 μm to 35 μm, which is beneficial to improving the vibration consistency and stability of the diaphragm 10. Specifically, since the conductive portion 12 is located on one surface of the main body 11 and is part of the vibration of the diaphragm 10, the stiffness of the conductive portion 12 also affects the compliance of the diaphragm 10. Therefore, in this embodiment, by controlling the thickness of the conductive portion 12 to be 0.5 μm to 50 μm, preferably 2 to 25 μm, the influence of the conductive portion 12 on the vibration of the diaphragm 10 can be reduced, and good vibration consistency can be ensured.

[0071] It should be noted that if the conductive part 12 is too thick, although the conductivity is high, the rigidity of the conductive part 12 is too large, which will worsen the vibration uniformity of the diaphragm 10 and limit the tensile deformation of the diaphragm 10. If the thickness of the conductive part is less than 0.5μm, it is easily limited by the processing technology, and the thickness uniformity and consistency of the conductive part 12 cannot be effectively guaranteed, resulting in unstable conductivity. Furthermore, cracks are prone to appear during the vibration of the diaphragm 10, which may increase the resistance.

[0072] According to one embodiment of the present invention, the particle size of the conductive particles 122 is no greater than 20 μm, which enables the conductive part 12 to possess both high conductivity and flexibility. It should be noted that the particle size of the conductive particles 122 affects the resistivity and flexibility of the conductive part 12. If the particle size of the conductive particles 122 is larger, the conductive part 12 will lack sufficient toughness and will be prone to breakage during vibration.

[0073] Therefore, in this embodiment, by controlling the particle size of the conductive particles 122 to be no greater than 20 μm, for example, the particle size of the conductive particles 122 is 5 μm, 10 μm, 12 μm, 15 μm and 20 μm, the toughness and conductivity of the conductive part 12 can be guaranteed, thereby enabling the diaphragm 10 to have both good conductivity and conductivity stability, and improving the toughness of the diaphragm 10 and extending the service life of the diaphragm 10.

[0074] In some specific embodiments of the present invention, the conductive particles 122 include at least one of metal particles and carbon-containing particles. The metal particles may be at least one of gold, silver, copper, nickel, zinc, aluminum, etc. The carbon-containing particles may be at least one of graphene, carbon black, carbon nanotubes, etc. In this embodiment, using metal particles and / or carbon-containing particles as the conductive particles 122 helps to ensure the high conductivity of the conductive particles 122.

[0075] Optionally, while the particle size of the conductive particles 122 is no greater than 20 μm, the conductive particles 122 include at least one of metal particles and carbon-containing particles. The conductive particles 122 enable the conductive part 12 to conduct electricity, thus achieving circuit continuity. The particle size and quantity of the conductive particles 122 directly affect the resistivity and flexibility of the conductive part 12. If the particle size is too large, the conductive material lacks toughness and is prone to breakage during vibration. If the conductive particle content is higher, the resistance is lower, and the diaphragm product performance will be higher; however, an increase in conductive particles will lead to insufficient toughness of the conductive part 12. Therefore, by controlling the conductive particle content to ≥50% wt% and the particle size to ≤20 μm, the diaphragm 10 can be guaranteed to have good conductivity and conductivity stability. Optionally, the conductive particles can be at least one of spherical, quasi-spherical, linear, sheet-like, or dendritic shapes.

[0076] According to one embodiment of the present invention, the content of conductive particles 122 in the conductive part 12 is not less than 50% wt and not more than 95% wt, which enables the conductive part 12 to have both toughness and conductivity. The number of conductive particles 122 also affects the resistivity and flexibility of the conductive part 12. If the content of conductive particles 122 is too large, although the resistance of the conductive part 12 is reduced and the conductivity of the diaphragm 10 is improved, the increase of conductive particles 122 can easily lead to insufficient toughness of the conductive part 12.

[0077] Therefore, in this embodiment, by controlling the content of conductive particles 122 in the conductive part 12 to be not less than 50% wt and not more than 95% wt, for example, the content of conductive particles 122 is 50% wt, 55% wt, 60% wt, 70% wt, etc., the conductive part 12 can be made to have both flexibility and high conductivity.

[0078] In this design, when the conductive part 12 is embedded in the main body 11, a groove may be provided on the main body 11. A portion of the conductive part 12 is disposed within the groove in the main body 11, while the surface of another portion is exposed outside the main body 11. Furthermore, the outer surface of the conductive part 12 may be flush with or protrude from the outer surface of the main body 11. Therefore, this structure effectively ensures the assembly stability of the conductive part 12 on the main body 11. The embedding of the conductive part 12 in the main body 11 can, to some extent, reduce the thickness of the diaphragm 10, increasing the design space of the product. In addition, the embedding of the conductive part 12 in the main body 11 can improve the vibration consistency between the conductive part 12 and the main body 11, thereby enhancing the sound production effect of the diaphragm 10.

[0079] When the conductive part 12 is disposed on the surface of the main body 11, the conductive part 12 can be coated or bonded to the surface of the main body 11; or, the main body 11 and the conductive part 12 can be integrally injection molded. That is, when the conductive part 12 is disposed on the surface of the main body 11, the conductive part 12 and the main body 11 can have various bonding methods. For example, the conductive part 12 can be disposed on the surface of the main body 11 by coating, by bonding, or by integral injection molding. Therefore, the diaphragm 10 according to the embodiment of the present invention has a simple structure, is easy to manufacture, and facilitates the electrical connection of the conductive part 12 to the voice coil 20 of the sound-generating device or to an external circuit.

[0080] According to one embodiment of the present invention, there are multiple conductive parts 12, which are spaced apart and located on the same side or opposite sides of the main body 11. For example, there are two conductive parts 12, which are spaced apart and located on the same side or both sides of the main body 11. The number and location of the conductive parts 12 can be selected according to actual usage requirements.

[0081] In other words, the diaphragm 10 of this embodiment may include two or more conductive portions 12 that are separated from each other. Each conductive portion 12 is located in the folded ring portion 111 of the diaphragm 10 and the outer edge portion 112 and inner edge portion 113 connected thereto. The positive and negative terminals of the circuit are connected to different conductive portions 12 respectively. At the same time, because the conductive portion 12 connects the folded ring portion 111 and the outer edge portion 112 and inner edge portion 113 connected thereto, the circuit connection is easier to operate and has stronger mass production capability. It should be noted that when there are multiple conductive portions 12, some conductive portions 12 can play a balancing role. That is, the circuit can selectively connect at least one of the multiple conductive portions 12. Two adjacent conductive portions 12 on the same side can also be connected by leads to control the series and parallel connection, thereby controlling the total resistance.

[0082] Depending on the actual use of the diaphragm 10, the conductive parts 12 in different locations can be placed on the same surface of the diaphragm 10, or they can be designed to be distributed on two surfaces of the diaphragm 10. This is because the design of the conductive parts 12 is equivalent to adding a reinforcing rib structure to the main body 11. When all the conductive parts 12 are distributed on the same side surface of the diaphragm 10, compliance asymmetry may occur, resulting in a large difference in the upper and lower amplitudes.

[0083] According to one embodiment of the present invention, the main body 11 includes a folded ring portion 111, an outer edge portion 112 disposed outside the folded ring portion 111, and an inner edge portion 113 disposed inside the folded ring portion 111. A conductive portion 12 is disposed in the folded ring portion 111, the inner edge portion 113, and the outer edge portion 112. For example, the main body 11 is composed of the outer edge portion 112, the folded ring portion 111, and the inner edge portion 113 from the outside to the inside, and the conductive portion 12 penetrates the outer edge portion 112, the folded ring portion 111, and the inner edge portion 113 of the main body 11. Thus, in this embodiment, by employing the folded ring portion 111, the inner edge portion 113, and the outer edge portion 112, it is convenient to realize the electrical connection of the diaphragm 10 to the voice coil 20 and the external circuit.

[0084] In some specific embodiments of the present invention, the conductive part 12 includes a first electrical connection part located at the inner edge 113 and a second electrical connection part located at the outer edge 112. The first electrical connection part is electrically connected to the voice coil 20, and the second electrical connection part is electrically connected to an external circuit. In this embodiment, by employing the cooperation of the first and second electrical connection parts, the conductive part 12 is electrically connected to the voice coil 20 and the external circuit, thus solving the problems of loss of internal vibration space caused by connecting components such as centering supports in the prior art, as well as the easy breakage of the voice coil 20 leads.

[0085] According to one embodiment of the present invention, the conductive part 12 further includes a third electrical connection part disposed on the folded ring part 111, and the first electrical connection part, the second electrical connection part and the third electrical connection part are all exposed on the outer surface of the main body part 11.

[0086] In other words, the inner edge portion 113 is provided with a first electrical connection portion, the outer edge portion 112 is provided with a second electrical connection portion, and the folded ring portion 111 is provided with a third electrical connection portion that can electrically connect the first electrical connection portion and the second electrical connection portion. The first electrical connection portion, the second electrical connection portion, and the third electrical connection portion together constitute the conductive portion 12. At least a portion of the conductive portion 12 can be exposed on the outer surface of the main body portion 11, thereby facilitating electrical connection with external circuits.

[0087] It should be noted that there are no special restrictions on the electrical connection between the conductive part 12, the voice coil 20, and the external circuit, as long as it can achieve the effect of electrically connecting the voice coil 20 and the external circuit. Considering the assembly relationship between the diaphragm 10, the voice coil 20, and the external circuit, the first electrical connection part can be electrically connected to the voice coil 20, and the second electrical connection part can be electrically connected to the external circuit.

[0088] In some specific embodiments of the present invention, such as Figure 2As shown, the diaphragm 10 also includes a damping layer 115, which is located between the thermoplastic material layer 114a and the rubber material layer 114b. The damping layer 115 comprises at least one of acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive, and polyurethane. The damping layer 115 can act as a buffer, reducing the interaction force between the thermoplastic material layer 114a and the rubber material layer 114b during vibration, effectively solving the problem of delamination during large displacements.

[0089] Therefore, in this embodiment, by providing a damping layer 115 between the thermoplastic material layer 114a and the rubber material layer 114b, and defining the characteristics of the damping layer 115, it is beneficial to compensate for the interfacial bonding effect between the rubber material layer 114b and the thermoplastic material layer 114a, and at the same time, it can effectively buffer vibration impact and avoid the risk of interlayer delamination.

[0090] In summary, according to the embodiments of the present invention, the conductive portion 12 enables the diaphragm 10 to have conductive properties. Compared to a pure rubber diaphragm, the thermoplastic material in the main body 11 can reduce the thickness of the diaphragm 10, i.e., reduce the weight of the diaphragm 10. Furthermore, the diaphragm 10 also has high rigidity and high elasticity while being thinner. In addition, the thermoplastic material can act as a barrier between the conductive portion 12 and the rubber material, reducing the influence of rubber material vulcanization precipitates on resistance, resulting in a low resistance change rate of the diaphragm 10 after damp heat reliability testing.

[0091] The present invention also provides a sound generating device, which includes a diaphragm 10 of any of the above embodiments. Since the diaphragm 10 has the above advantages, the sound generating device also has the above advantages. For example, the sound generating device has low distortion, high loudness, and high fidelity sound quality, which will not be elaborated here.

[0092] It should be noted that the diaphragm 10 provided by this invention can be configured into sound-generating devices of any structure. For example... Figure 5 As shown, a sound-generating device according to an embodiment of the present invention includes a housing, a magnetic circuit system disposed within the housing, and a vibration system cooperating with a vibration system. The vibration system includes a diaphragm 10 and a voice coil 20 coupled to one side of the diaphragm 10. The magnetic circuit system drives the voice coil 20 to vibrate, thereby causing the diaphragm 10 to produce sound. The diaphragm 10 is the diaphragm 10 described in the above embodiment. Specifically, when the sound-generating device is working, after the voice coil 20 is energized, under the action of the magnetic field force of the magnetic circuit system, the voice coil 20 can vibrate up and down to drive the diaphragm 10 to vibrate, and the diaphragm 10 can produce sound when it vibrates.

[0093] A sound-generating device according to another embodiment of the present invention, such as Figure 6As shown, it includes a housing and a magnetic circuit system and a vibration system disposed within the housing. The vibration system includes a voice coil 20, a first diaphragm 21 and a second diaphragm 22. The top of the voice coil 20 is connected to the first diaphragm 21. The magnetic circuit system drives the voice coil 20 to vibrate so as to drive the first diaphragm 21 to produce sound. The two ends of the second diaphragm 22 are respectively connected to an external circuit and the bottom of the voice coil 20. The second diaphragm 22 is the diaphragm 10 of the above embodiment.

[0094] In other words, the sound-generating device according to the embodiments of the present invention may further include two diaphragms 10 prepared by the above embodiments of the present invention, namely a first diaphragm 21 and a second diaphragm 22. The first diaphragm 21 can be used to vibrate and generate sound, and the second diaphragm 22 can be used to balance the vibration of the voice coil 20. Specifically, when the sound-generating device is working, after the voice coil 20 is energized, under the action of the magnetic field force of the magnetic circuit system, the voice coil 20 can vibrate up and down to drive the first diaphragm 21 to vibrate, and the first diaphragm 21 can generate sound when it vibrates. The second diaphragm 22 can also vibrate up and down with the voice coil 20. Since the two ends of the second diaphragm 22 are respectively connected to the external circuit and the bottom of the voice coil 20, the second diaphragm 22 can balance the vibration of the voice coil 20 and prevent the voice coil 20 from becoming polarized, thereby improving the sound generation effect of the sound-generating device.

[0095] It should be noted that the first diaphragm 21 and the second diaphragm 22 can both adopt the diaphragm 10 of the above embodiments of the present invention, or one of the first diaphragm 21 and the second diaphragm 22 can adopt the diaphragm 10 of the above embodiments of the present invention. The present invention does not make specific limitations in this regard.

[0096] The electronic device according to the present invention includes the sound-generating device of the above embodiment, and the sound-generating device adopts the diaphragm 10 of the above embodiment. Since the diaphragm 10 of the above embodiment of the present invention has the above-mentioned technical effects, the electronic device according to the present invention also has the corresponding technical effects, which can avoid the problems of loss of internal vibration space and easy breakage of voice coil 20 leads caused by the assembly of connecting parts such as centering support plates in the prior art, and can meet the requirements of large displacement, high loudness, and high sensitivity of the product.

[0097] The present invention also provides an electronic device including the sound-generating device of any of the above embodiments. Since the sound-generating device has the above advantages, the electronic device of the present invention also has the above advantages, which will not be elaborated here.

[0098] The diaphragm 10 and the sound-generating device according to embodiments of the present invention will be described in detail below with reference to specific examples.

[0099] Example 1

[0100] The main body 11 is a composite material of a 90μm thick polyurethane rubber material layer (hardness 50D) and polyetheretherketone (thickness about 9-10μm). The conductive part 12 is provided on the surface of polyetheretherketone and contains polyurethane resin and silver powder (particle size 20nm-10μm, addition amount 70%).

[0101] Example 2

[0102] The main body 11 is a composite material consisting of a 120μm thick polyurethane rubber material layer (hardness 50D) and a thermoplastic polyurethane elastomer layer (thickness 10μm) with a hardness of 95A. The conductive part 12 is disposed on the surface of the thermoplastic polyurethane elastomer and contains polyurethane resin and silver powder (particle size 20nm~10μm, addition amount 70%).

[0103] Comparative Example

[0104] The main material of the comparative example is a 150μm thick polyurethane rubber material (hardness 50D). The surface of the polyurethane rubber material is covered with a conductive material with a thickness of about 10μm, which includes polyurethane resin and silver powder (particle size 20nm~10μm, addition amount 70%).

[0105] The preparation methods used in Examples 1 and 2 include the following steps:

[0106] The main body 11 is placed in a mold and hot-pressed at 170°C. After molding, it is cut to obtain a diaphragm 10 of a certain shape.

[0107] Then, the silver paste of the conductive part 12 is printed onto the surface of the diaphragm 10 by pad printing. After curing at 100°C for 30 minutes, the final diaphragm 10 is obtained. The voice coil 20 and magnetic circuit system are then assembled to obtain the sound-generating device.

[0108] The materials prepared in Examples 1, 2 and the comparative examples were subjected to the following tests.

[0109] Elongation at break of composite part: The composite part of the finished diaphragm is cut off with a cutter or similar tool, stretched using a DMA or micro tensile testing machine, and the strain at the point of fracture of the conductive part 12 or the main body part 11 is recorded. This is the elongation at break of the composite part.

[0110] Resistance test: A DC low resistance tester is used, with the two measuring heads placed at the inner and outer edges of the fold ring, respectively.

[0111] The ingredients and related test comparison data of the comparative examples and embodiments are summarized in Table 1.

[0112] Table 1. Mixture ratio and test results

[0113]

[0114] As shown in Table 1, the initial resistance of the comparative example was 0.055Ω, and the resistance after high temperature and high humidity was 0.35Ω. In Example 1, the initial resistance was 0.050Ω, and the resistance after high temperature and high humidity was 0.08Ω. In Example 2, the initial resistance was 0.053Ω, and the resistance after high temperature and high humidity was 0.2Ω. It is evident that, compared to the comparative example without a thermoplastic material layer, the presence of the thermoplastic material layer in Examples 1 and 2 improves the stability of the resistance, especially after high temperature and high humidity (85℃, 85% RH for 500 hours), the examples show a smaller change in resistance.

[0115] In addition, comparing Example 1 and Example 2, Example 1 contains polyetheretherketone, and the elongation at break of the composite part in Example 1 is 30% to 80%, while the elongation at break of Example 2 is 50% to 200%. It can be seen that although the barrier effect of polyetheretherketone in Example 1 is better than that of thermoplastic polyurethane elastomer, the elongation at break of the composite part is worse because the toughness and elasticity of polyetheretherketone are not as good as those of thermoplastic polyurethane elastomer.

[0116] By comparing Examples 1, 2 and the comparative examples, it can be found that the beneficial effects of providing a thermoplastic material layer 114a in the main body 11 include weight reduction and providing electrical resistance stability.

[0117] Next, the diaphragms from the comparative example, Example 1, and Example 2 were assembled into a sound-generating device, and acoustic tests were performed on the device. The frequency response test results are as follows: Figure 7 As shown.

[0118] pass Figure 7 The test results show that, above 1000Hz, Example 1 has the highest sound pressure level, followed by Example 2, while the comparative example has the lowest. This is because the presence of thermoplastic materials in Examples 1 and 2 reduces the thickness and weight of the diaphragm 10.

[0119] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A diaphragm, characterized in that, The device includes a main body and a conductive part. The main body is formed as a multi-layer composite structure. The main body includes a thermoplastic material layer and a rubber material layer stacked together. The thermoplastic material layer is disposed on the outermost side of the main body. The conductive part is disposed on the outermost side of the thermoplastic material layer of the main body. At least a portion of the conductive part is exposed outside the thermoplastic material layer to be electrically connected to a voice coil and an external circuit. The conductive part includes a matrix and conductive particles dispersed in the matrix. The matrix is ​​composed of a heterochain polymer with -NH-COO- characteristic groups. The resistance of the conductive part changes by less than 0.5Ω after 500 hours in an environment with a relative humidity of 85% and a temperature of 85°C.

2. The diaphragm according to claim 1, characterized in that, The portion of the main body that is directly opposite the conductive portion and the conductive portion together form a composite portion, and the elongation at break of the composite portion is greater than 30%.

3. The diaphragm according to claim 1, characterized in that, The heterochain polymer of the conductive part includes at least one of polyurethane, polyurethane acrylate copolymer, epoxy-modified polyurethane, and polyurethane-modified epoxy resin.

4. The diaphragm according to claim 1, characterized in that, The rubber material layer of the main body comprises at least one of nitrile rubber, hydrogenated nitrile rubber, acrylate rubber, polyurethane rubber, ethylene acrylate rubber, EPDM rubber, fluororubber, and silicone rubber.

5. The diaphragm according to claim 1, characterized in that, The thermoplastic material layer of the main body comprises at least one of thermoplastic polyurethane, thermoplastic polyester elastomer, thermoplastic polyimide material, polyether ether copper, thermoplastic polyester material, polyarylate, and polyetherimide.

6. The diaphragm according to claim 1, characterized in that, The thickness of the thermoplastic material layer is less than the thickness of the rubber material layer.

7. The diaphragm according to claim 1, characterized in that, The thickness of the diaphragm is 20μm to 150μm, and the thickness of the conductive part is 0.5μm to 35μm.

8. The diaphragm according to claim 1, characterized in that, The particle size of the conductive particles is no greater than 20 μm; And / or, the conductive particles include at least one of metal particles and carbon-containing particles.

9. The diaphragm according to claim 1, characterized in that, The content of the conductive particles in the conductive part is not less than 50% wt and not more than 95% wt.

10. The diaphragm according to claim 1, characterized in that, A portion of the conductive part is embedded in the main body; Alternatively, the conductive portion may be disposed on the outer surface of the main body portion.

11. The diaphragm according to claim 1, characterized in that, The conductive parts are multiple, and the multiple conductive parts are spaced apart and located on the same side or opposite sides of the main body.

12. The diaphragm according to claim 1, characterized in that, The main body includes a folded ring portion, an outer edge portion located outside the folded ring portion, and an inner edge portion located inside the folded ring portion. The conductive portion is located in the folded ring portion, the inner edge portion, and the outer edge portion.

13. The diaphragm according to claim 12, characterized in that, The conductive portion includes a first electrical connection portion located at the inner edge, a second electrical connection portion located at the outer edge, and a third electrical connection portion located at the folded ring portion. The first electrical connection portion is electrically connected to the voice coil, the second electrical connection portion is electrically connected to the external circuit, and the first electrical connection portion, the second electrical connection portion, and the third electrical connection portion are all exposed on the outer surface of the main body portion.

14. The diaphragm according to any one of claims 1-13, characterized in that, Also includes: A damping layer is located between the thermoplastic material layer and the rubber material layer, and the damping layer comprises at least one of acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive, and polyurethane.

15. A sound-generating device, characterized in that, Includes the diaphragm according to any one of claims 1-14.

16. An electronic device, characterized in that, Includes the sound-generating device as described in claim 15.

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