Vibrating diaphragm for sound production device, sound production device and electronic equipment

Abstract

The invention relates to the technical field of electro-acoustic conversion, and discloses a vibrating diaphragm for a sound production device, the sound production device and electronic equipment. The vibrating diaphragm comprises a main body part and a conductive part, the conductive part is arranged on the main body part, at least one part of the conductive part is exposed out of the main body part so as to be electrically connected with a voice coil of the sound production device and an external circuit, the conductive part comprises a base body and conductive materials dispersed in the base body, the conductive materials comprise a first silver wire and a second silver wire, the length of the first silver wire is 5-8 microns, and the length of the second silver wire is 5-8 microns. The length of the first silver wire ranges from 9 micrometers to 15 micrometers, the length of the second silver wire ranges from 9 micrometers to 15 micrometers, the diameter of the first silver wire and the diameter of the second silver wire range from 1 micrometer to 2 micrometers, the mass percentage content of the conductive material in the conductive part ranges from 50% to 90%, the surface resistivity of the conductive part is 5 * 101 omega.cm to 102 omega.cm, and the elongation at break of the conductive part is larger than or equal to 80%. According to the invention, the first silver wire and the second silver wire which are matched in a long-short manner are adopted in the conductive part, so that the elongation at break and the conductive stability of the vibrating diaphragm can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electroacoustic conversion, and more particularly to a diaphragm for a sound-generating device, a sound-generating device, and an electronic device. Background Art

[0002] The sound-generating device generally includes a diaphragm and a voice coil attached to one side of the diaphragm, as well as an electrical connector that electrically connects the internal circuit of the sound-generating device to the external circuit. The voice coil includes two voice coil leads, which are electrically connected to two pads of the electrical connector by spot welding or other methods. The electrical connector is also electrically connected to the external circuit to control the electrical signal in the voice coil via the electrical signal of the terminal product. Generally speaking, the lead of the voice coil needs to be threaded for a certain length and then suspended in the air to achieve electrical connection with the electrical connector. Although the suspended lead structure can achieve higher sensitivity, due to the limitation of the suspended lead, the amplitude of the voice coil cannot be too large, and the risk of disconnection is high. The low-frequency effect is not significant enough, and it cannot provide users with a better listening experience.

[0003] To address the aforementioned issues, related technologies have proposed a conductive diaphragm. This diaphragm is electrically conductive by providing a conductive layer on the diaphragm. The conductive diaphragm is then electrically connected to the voice coil leads and electrical connectors. However, the conductive layer of existing conductive diaphragms is formed using conductive silver wire and a base material. To reduce the resistivity of the conductive layer, the conductive silver wire is relatively long, resulting in a decrease in the diaphragm's elongation at break. During operation of the sound-generating device, the conductive silver wire is prone to bending and breaking during the reciprocating vibration of the diaphragm, thus affecting the diaphragm's conductive stability. Summary of the Invention

[0004] An object of the present invention is to provide a new technical solution for a diaphragm of a sound-generating device.

[0005] According to a first aspect of the present invention, a diaphragm for a sound-generating device is provided. The diaphragm includes a main body and a conductive portion, the conductive portion being provided on the main body, at least a portion of the conductive portion being exposed from the main body to be electrically connected to the voice coil of the sound-generating device and an external circuit, the conductive portion including a substrate and a conductive material dispersed within the substrate, the conductive material including a first silver wire and a second silver wire, the first silver wire having a length of 5 μm to 8 μm, the second silver wire having a length of 9 μm to 15 μm, the first silver wire and the second silver wire having a diameter of 1 μm to 2 μm, the conductive material having a mass percentage in the conductive portion of 50% to 90%, and the surface resistivity of the conductive portion being 5*10 ⁻1 Ω·cm -10 ⁻2 Ω·cm, and the elongation at break of the conductive portion is ≥80%.

[0006] Optionally, in the conductive material, a mass content ratio of the second silver wire to the first silver wire is α, wherein 7 / 3≤α≤19 / 1.

[0007] Optionally, the purity of the first silver wire and / or the second silver wire is ≥99.99%.

[0008] Optionally, the matrix comprises ethylene-acrylate rubber, and the molecular formula of the ethylene-acrylate rubber is:

[0009] Wherein, x, y are natural numbers; R is an alkyl group; and / or,

[0010] Wherein, x, y, and z are natural numbers; R and R' are alkyl groups.

[0011] Optionally, after being placed under conditions of a temperature of 90° C. and a humidity of 60% for 16 hours, a change rate of the elastic modulus of the conductive portion is ≤8.7%.

[0012] Optionally, the mass change rate of the diaphragm after being immersed in ethyl acetate solvent for 50 hours is ≤15%.

[0013] Optionally, the matrix further includes a filler, the filler includes an antioxidant, the antioxidant includes one or more of antioxidant N-445, antioxidant 246, and antioxidant 4010, and the weight percentage of the antioxidant in the conductive portion is 0.1%-6%; And / or, the matrix further includes a crosslinking agent, which is at least one of metal oxides, metal peroxides, organic oxides, organic peroxides, and amine vulcanization systems, and in the conductive portion, the mass percentage of the crosslinking agent is 1%-7%.

[0014] Optionally, the tensile strength of the conductive portion when broken is 2 MPa-10 MPa; and / or the tensile strength of the first silver wire and / or the second silver wire is 100 MPa-200 MPa.

[0015] Optionally, the room temperature storage modulus of the conductive portion is 100 MPa-200 MPa.

[0016] Optionally, the glass transition temperature of the diaphragm is ≤-10°C.

[0017] Optionally, the main body comprises polyacrylate rubber.

[0018] According to a second aspect of the present invention, a sound-generating device is provided, comprising the diaphragm of the present invention.

[0019] According to a third aspect of the present invention, an electronic device is provided, comprising the sound-generating device of the present invention.

[0020] In an embodiment of the present invention, the diaphragm includes a main body and a conductive part, the conductive part is provided in the main body, at least a portion of the conductive part is exposed from the main body to be electrically connected to the voice coil of the sound-emitting device and the external circuit, the conductive part includes a matrix and a conductive material dispersed in the matrix, the conductive material includes a first silver wire with a length of 5μm-8μm and a second silver wire with a length of 9μm-15μm, and the diameter of the first silver wire and the second silver wire is 1μm-2μm. The long and short first silver wires and the second silver wires can ensure that the surface resistivity of the conductive part is low and the elongation at break of the conductive part is high. For example, the surface resistivity of the conductive part is 10 ⁻1 Ω·cm -10 ⁻2 Ω·cm, and the elongation at break of the conductive portion is ≥80%. The conductive material comprises 50%-90% by weight of the conductive portion, which ensures the conductive portion is lightweight, allows the diaphragm to achieve maximum vibration amplitude, and is less prone to breakage, thereby improving the stability of the conductive portion.

[0021] 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 accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0023] Figure 1 is a cross-sectional view of a diaphragm according to an embodiment of the present invention.

[0024] Figure 2 is a perspective view of a sound-generating device according to an embodiment of the present invention.

[0025] Figure 3 is a cross-sectional view of a sound generating device according to an embodiment of the present invention.

[0026] Figure 4 1 is a curve showing the impedance of the diaphragm changing with frequency according to an embodiment of the present invention.

[0027] Figure 5 This is the curve of the impedance change of the proportional diaphragm with frequency.

[0028] Reference numerals: 100. Sound-generating device; 10. Housing; 20. Diaphragm; 21. Main body; 22. Conductive portion; 30. Voice coil; 40. Permanent magnet. DETAILED DESCRIPTION

[0029] 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 of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0030] 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.

[0031] 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 part of the specification.

[0032] 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.

[0033] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0034] The following describes in detail the diaphragm for a sound-generating device according to an embodiment of the present invention with reference to the accompanying drawings.

[0035] According to one embodiment of the present invention, a diaphragm 20 for a sound-generating device is provided. Figure 1 As shown, the diaphragm 20 includes a main body 21 and a conductive part 22, the conductive part 22 is provided on the main body 21, at least a portion of the conductive part 22 is exposed from the main body 21 to be electrically connected to the voice coil of the sound-generating device and the external circuit, the conductive part 22 includes a substrate and a conductive material dispersed in the substrate, the conductive material includes a first silver wire and a second silver wire, the length of the first silver wire is 5μm-8μm, the length of the second silver wire is 9μm-15μm, the diameter of the first silver wire and the second silver wire is 1μm-2μm, and the surface resistivity of the conductive part 22 is 5*10 ⁻1 Ω·cm -10 ⁻2 Ω·cm, and the elongation at break of the conductive portion 22 is ≥80%.

[0036] Specifically, the main body 21 and the conductive part 22 of the diaphragm 20 are combined together to form an integral structure. The material of the main body 21 is plastic, rubber, thermoplastic elastomer or a combination of the above. The main body 21 is a folded ring structure or a planar structure. The conductive part 22 is fixed to the main body 21 by bonding, hot pressing, injection molding, etc. Optionally, the conductive part 22 is located on the side of the main body 21 facing the voice coil. The conductive part 22 is at least partially exposed radially inward and / or inwardly along the main body 21 to facilitate connection with the voice coil and the external circuit.

[0037] The conductive portion 22 is primarily composed of a matrix and a conductive material. The matrix is ​​a polymer material, such as plastic, rubber, thermoplastic elastomer, or a mixture of these. The conductive material is evenly dispersed within the matrix. The conductive material includes two types of silver filaments of different lengths. The first silver filament is shorter, ranging from 5μm to 8μm; the second silver filament is longer, ranging from 9μm to 15μm. The diameters of both the first and second silver filaments are 1μm to 2μm. The conductive properties of the conductive portion 22 are affected by the length of the silver filaments. The longer second silver filaments can more easily form a continuous conductive network in the conductive portion 22, thereby improving the conductive properties of the conductive portion 22. Furthermore, the longer second silver filaments have a wider distribution range, making the conductive network more uniform and the resistivity of the conductive portion 22 lower. However, as the length of the second silver filaments increases, for example, when the length of the second silver filaments exceeds 15μm, the second silver filaments are more likely to bend or break, especially when subjected to stress. The bending or breaking of the second silver wire will affect the stability of the conductive network and will also reduce the elongation at break of the diaphragm 20. When the length of the second silver wire is 9μm-15μm, the resistivity of the conductive part 22 is low, the conductive performance is excellent, the conductive stability is high and the elongation at break of the diaphragm 20 will not decrease too much. The length of the first silver wire is 5μm-8μm. The mechanical properties of the first silver wire with a shorter length are relatively stable and not easy to bend or break. Therefore, the first silver wire with a length of 5μm-8μm can ensure that the elongation at break of the conductive part 22 is high. The long and short matched first and second silver wires can ensure that the resistivity of the conductive part 22 is low and the elongation at break of the conductive part 22 is high. For example, the surface resistivity of the conductive part 22 is 10 ⁻1 Ω·cm -10 ⁻2 Ω·cm, and the elongation at break of the conductive portion 22 is ≥80%.

[0038] In addition, the mass percentage of the conductive material in the conductive part 22 is 50%-90%. If the mass percentage of the conductive material in the conductive part 22 is too low, for example, less than 50%, the conductive performance of the conductive part 22 is low, affecting the conductive effect of the diaphragm. As the content of the conductive material in the conductive part 22 increases, the overall density of the conductive part 22 increases significantly, resulting in an increase in the mass of the diaphragm 20. The maximum amplitude that the diaphragm 20 can reach under the same driving force is significantly reduced, and the low-frequency FR of the diaphragm 20 is low. At the same time, as the content of the conductive material in the conductive part 22 increases, the content of the matrix in the conductive part 22 is relatively reduced, resulting in the conductive part 22 being prone to breakage. When the mass percentage of the conductive material in the conductive part 22 is 50%-90%, it can ensure that the mass of the conductive part 22 is light, the low-frequency FR of the diaphragm 20 is high, and the conductive part 22 is not prone to breakage. Optionally, the mass percentage of the conductive material in the conductive portion 22 is 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, etc.

[0039] In an embodiment of the present invention, the diaphragm 20 includes a main body 21 and a conductive part 22, wherein the conductive part 22 is provided on the main body 21, and at least a portion of the conductive part 22 is exposed outside the main body 21 to be electrically connected to the voice coil and the external circuit of the sound-emitting device, and the conductive part 22 includes a matrix and a conductive material dispersed in the matrix, wherein the conductive material includes a first silver wire with a length of 5μm-8μm and a second silver wire with a length of 9μm-15μm, and the diameter of the first silver wire and the second silver wire is 1μm-2μm. The long and short first silver wires and the second silver wires can ensure that the surface resistivity of the conductive part 22 is low and the elongation at break of the conductive part 22 is high. For example, the surface resistivity of the conductive part 22 is 10 ⁻1 Ω·cm -10 ⁻2 Ω·cm, and the elongation at break of the conductive portion 22 is ≥80%. The conductive material content of the conductive portion 22 is 50%-90% by mass, which ensures that the conductive portion 22 is lightweight and the low-frequency FR of the diaphragm 20 is high, while also making the conductive portion 22 less prone to breakage and improving its stability.

[0040] In some specific embodiments of the present invention, in the conductive material, a mass ratio of the second silver wire to the first silver wire is α, wherein 7 / 3≤α≤19 / 1.

[0041] In this embodiment, the second silver wire and the first silver wire are added to the matrix in a mass ratio of 7 / 3 to 19 / 1. The longer second silver wire is more likely to form a continuous conductive network and reduce contact resistance, but excessive second silver wire content may lead to uneven dispersion and a decrease in the elongation at break of the conductive portion 22. The shorter first silver wire is not easy to form a continuous conductive network, but the addition of the first silver wire can improve the elongation at break of the conductive portion. If there are too many first silver wires, the overall resistivity of the conductive portion 22 will increase. Therefore, the mass content ratio of the second silver wire to the first silver wire is within the above range, which can ensure that the conductive portion 22 has a lower resistivity and a higher elongation at break. Optionally, the mass content ratio of the second silver wire to the first silver wire can be 7 / 3, 3, 5, 7, 9, 10, 13, 15, 17, 19, etc.

[0042] In some specific embodiments of the present invention, the purity of the first silver wire and / or the second silver wire is ≥99.99%.

[0043] In this embodiment, high-purity first and / or second silver wires are selected as the conductive material. For example, the purity of the first and / or second silver wires is greater than or equal to 99.99%. This increases the electrical conductivity of the first and / or second silver wires, further reducing the surface resistivity of the conductive portion 22.

[0044] Optionally, the purity of the first silver wire and / or the second silver wire is 99.99%, 99.995%, 99.999%, etc., and those skilled in the art can make a selection according to actual needs.

[0045] In some specific embodiments of the present invention, the matrix comprises ethylene-acrylate rubber, and the molecular formula of the ethylene-acrylate rubber is:

[0046] Wherein, x, y are natural numbers; R is an alkyl group; and / or,

[0047] Wherein, x, y, and z are natural numbers; R and R' are alkyl groups.

[0048] When preparing the conductive portion 22, the substrate is made of a binary AEM rubber or a ternary AEM rubber, or a blend of the binary and ternary AEM rubbers. AEM rubber itself has strong high-temperature resistance, which significantly improves the high-temperature resistance of the conductive portion 22, allowing the conductive portion 22 to maintain high resilience even at high temperatures.

[0049] Of course, in other embodiments, the matrix may also be other rubbers, such as styrene-butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, nitrile rubber, etc. Those skilled in the art may make a choice according to actual needs.

[0050] In some specific embodiments of the present invention, the main body 21 includes polyacrylate rubber.

[0051] In this embodiment, the polyacrylate rubber includes acrylic rubber (i.e., ACM rubber), ethylene-acrylate rubber (AEM rubber), or a mixture of the two. Polyacrylate rubber has excellent high-temperature resistance, and the matrix made of polyacrylate rubber and ethylene-acrylate rubber has good compatibility, effectively preventing loose adhesion between the main body 21 and the matrix, thereby improving the vibration consistency of the diaphragm 20.

[0052] In some specific embodiments of the present invention, after being placed under conditions of a temperature of 90° C. and a humidity of 60% for 16 hours, the elastic modulus change rate of the conductive portion 22 is ≤8.7%.

[0053] In this embodiment, high temperature and high humidity conditions have an impact on the stability of the conductive part 22. According to the rate of change of the elastic modulus of the conductive part 22 under high temperature and high humidity conditions, the stability of the conductive part 22 can be obtained. The rate of change of the elastic modulus of the conductive part 22 is the percentage of the change in the elastic modulus of the conductive part 22 before and after being placed at a temperature of 90°C and a humidity of 60% for 16 hours to the elastic modulus of the conductive part 22 before being placed at a temperature of 90°C and a humidity of 60%. Since the silver wire in the conductive part is strong and does not react or decompose under high temperature and high humidity conditions, the elastic modulus of the conductive part 22 under high temperature and high humidity conditions changes little. In this embodiment, after being placed at a temperature of 90°C and a humidity of 60% for 16 hours, the rate of change of the elastic modulus of the conductive part 22 is ≤8.7%. The conductive part 22 within this range can effectively reduce the swing vibration of the diaphragm 20 and improve the F0 stability of the diaphragm 20.

[0054] In some specific embodiments of the present invention, the mass change rate of the diaphragm 20 after being immersed in ethyl acetate solvent for 50 hours is ≤15%.

[0055] In this embodiment, the chemical stability of the diaphragm 20 is evaluated by soaking the diaphragm 20 in ethyl acetate solvent. The mass of the diaphragm 20 after soaking in ethyl acetate solvent for 50 hours is compared with the mass of the diaphragm 20 before soaking. The mass of the diaphragm 20 usually decreases after soaking. The mass change rate of the diaphragm 20 is the percentage of the difference between the mass of the diaphragm 20 before and after soaking and the mass of the diaphragm 20 before soaking. When the mass change rate is too high, for example, greater than 15%, the chemical stability of the diaphragm 20 is poor. In the embodiment of the present invention, the mass change rate of the diaphragm 20 after soaking in ethyl acetate solvent for 50 hours is ≤15%, and the chemical stability of the diaphragm 20 is excellent. This is mainly because the conductive material silver wire is an inorganic material. The silver wire itself has excellent chemical stability. The silver wire in the conductive part 22 reduces the effective contact area between the substrate and the ethyl acetate solvent, thereby significantly improving the solvent resistance of the conductive part 22, and the chemical stability of the diaphragm 20 is excellent.

[0056] In some specific embodiments of the present invention, the matrix further includes a filler, the filler includes an antioxidant, and the antioxidant includes one or more of antioxidant N-445, antioxidant 246, and antioxidant 4010. In the conductive portion 22, the weight percentage of the antioxidant is 0.1%-6%; And / or, the matrix further includes a crosslinking agent, which is at least one of metal oxides, metal peroxides, organic oxides, organic peroxides, and amine vulcanization systems, and in the conductive portion 22, the mass percentage of the crosslinking agent is 1%-7%.

[0057] In this embodiment, at least one of the antioxidant N-445, antioxidant 246, and antioxidant 4010 is added to the rubber compound to improve the anti-aging effect of the diaphragm 20.

[0058] During long-term use, the matrix will age and degrade to produce active free radicals. Active free radicals can accelerate the aging of the matrix itself. Anti-aging agents can inactivate active free radicals, thereby slowing down the aging and breakage of the molecular chains of the matrix and extending the service life of the matrix. When the antioxidant content is too low, for example, when the mass proportion of the antioxidant in the matrix is ​​less than 0.1wt%, it is difficult to meet the service life requirements of the diaphragm 20; when the antioxidant content is too high, for example, when the mass proportion of the antioxidant in the matrix is ​​greater than 6wt%, the antioxidant is prone to agglomeration in the matrix, resulting in a decrease in the mechanical properties of the conductive part 22 and a risk of film breakage during processing. When the mass proportion of the antioxidant in the matrix is ​​0.1wt%-6wt%, it can not only extend the service life of the conductive part 22, but also avoid agglomeration in the matrix.

[0059] Optionally, the antioxidant accounts for 0.1wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt% and the like in the matrix, and those skilled in the art can make the selection according to actual needs.

[0060] In this embodiment, at least one of metal oxides, metal peroxides, organic oxides, organic peroxides, and amine vulcanization systems is added to the matrix to perform a cross-linking reaction.

[0061] The amount of cross-linking agent used directly affects the network structure inside the conductive part 22. In the matrix, when the amount of cross-linking agent used is too low, for example, the mass ratio is less than 1wt%, the cross-linking degree of the rubber after vulcanization is low. The network structure inside the conductive part 22 is too loose, resulting in low mechanical strength of the conductive part 22. When the conductive part 22 is deformed under external load, the conductive part 22 is prone to fracture, making it difficult to meet the use requirements of the sound-generating device. In the rubber compound, when the amount of cross-linking agent used is too high, for example, the mass ratio is greater than 7wt%, the cross-linking degree of the rubber after vulcanization is too high, and the internal network structure of the conductive part 22 is prone to local over-tightness, resulting in too low elongation at break of the conductive part 22, poor toughness, and prone to brittle fracture during long-term use. When the mass ratio of the cross-linking agent in the rubber compound is 1wt%-7wt%, the cross-linking degree of the rubber is moderate, the conductive part 22 has suitable mechanical strength, the internal network structure of the conductive part 22 is good in uniformity, the toughness of the conductive part 22 is good, and it is not easy to fracture.

[0062] Optionally, the crosslinking agent accounts for 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt% in the rubber compound, etc. Those skilled in the art can select the crosslinking agent according to actual needs.

[0063] In some specific embodiments of the present invention, the tensile strength of the conductive portion 22 when broken is 2 MPa-10 MPa; and / or the tensile strength of the first silver wire and / or the second silver wire is 100 MPa-200 MPa.

[0064] In this embodiment, the conductive portion 22 includes first and second silver wires of different lengths. When the tensile strength of the first and second silver wires is too low, for example, less than 100 MPa, the first and second silver wires are easily broken during molding or air pressure forming of the diaphragm 20. When the tensile strength of the first and second silver wires is too high, for example, greater than 200 MPa, the hardness of the first and second silver wires is too high, resulting in incomplete molding during the preparation of the diaphragm 20, and the diaphragm 20 cannot be formed with the set size and structure. When the tensile strength of the first and / or second silver wires is between 100 MPa and 200 MPa, the conductive material is not easily broken during molding, and the diaphragm 20 is easily molded into place.

[0065] When the tensile strength of the conductive portion 22 at break is too low, for example, less than 2 MPa, the conductive portion 22 is easily broken during molding. When the tensile strength of the conductive portion 22 at break is too high, for example, greater than 10 MPa, the conductive portion 22 has poor processability, increased brittleness, and is prone to film breakage during molding. When the tensile strength of the conductive portion 22 at break is between 2 MPa and 10 MPa, the conductive portion 22 is less likely to break during molding, and film breakage is less likely to occur.

[0066] Optionally, the tensile strength of the conductive portion 22 when broken is 2 MPa, 4 MPa, 6 MPa, 8 MPa, 10 MPa, etc.; the tensile strength of the first silver wire and / or the second silver wire is 100 MPa, 120 MPa, 140 MPa, 150 MPa, 180 MPa, 200 MPa, etc. Those skilled in the art may select the strength according to actual needs.

[0067] In some specific embodiments of the present invention, the room temperature storage modulus of the diaphragm 20 is 100 MPa-200 MPa.

[0068] In this embodiment, the greater the room temperature storage modulus of the diaphragm 20, the greater the hardness; conversely, the smaller the hardness. When the room temperature storage modulus of the diaphragm 20 is less than 100 MPa, the hardness of the diaphragm 20 is too low and does not meet the use requirements of the diaphragm 20. When the hardness of the diaphragm 20 is greater than 200 MPa, the toughness of the diaphragm 20 is poor, the elongation at break is low, and the membrane rupture phenomenon is prone to occur. When the room temperature storage modulus of the diaphragm 20 is 100 MPa-200 MPa, the diaphragm 20 has sufficient hardness and toughness, and the membrane rupture phenomenon is not prone to occur. In addition, the room temperature storage modulus of the diaphragm 20 is 100 MPa-200 MPa, which makes the F0 of the sound-generating device using the diaphragm 20 relatively low, for example, it can reach 600 Hz-1800 Hz.

[0069] Optionally, the room temperature storage modulus of the diaphragm 20 is 100 MPa, 120 MPa, 140 MPa, 160 MPa, 180 MPa, 200 MPa, etc. Those skilled in the art may make a selection according to actual needs.

[0070] In some specific embodiments of the present invention, the glass transition temperature of the diaphragm 20 is ≤-10°C.

[0071] In this embodiment, since the glass transition temperature of the diaphragm 20 is ≤-10° C., the diaphragm 20 is in a highly elastic state at room temperature, and the diaphragm 20 has good resilience performance.

[0072] When the glass transition temperature of the diaphragm 20 is ≤ -10°C, it maintains good elasticity during operation at temperatures below 0°C, resulting in a sound-generating device using this diaphragm 20 exhibiting higher sound quality. This glass transition temperature reduces the risk of damage to the diaphragm 20 in low-temperature environments, improving the reliability of the diaphragm 20. Furthermore, the lower glass transition temperature ensures a high consistency in the storage modulus of the diaphragm 20 when operating above the glass transition temperature, resulting in excellent F0 stability over a wide temperature range.

[0073] Optionally, the glass transition temperature of the diaphragm 20 is ≤-15° C. This range can further reduce the risk of damage to the diaphragm 20 in a low-temperature environment and improve the F0 stability of the diaphragm 20 in a wider temperature range.

[0074] According to another embodiment of the present invention, a sound generating device is provided. Figure 2-Figure 3 As shown, the sound-generating device 100 includes the diaphragm 20 of the above embodiment.

[0075] like Figure 2-Figure 3 As shown, the sound-generating device 100 may include a housing 10, a magnetic circuit system, and a vibration system. The magnetic circuit system includes a permanent magnet 40, which is used to form a magnetic gap. The vibration system includes a diaphragm 20 and a voice coil 30. The diaphragm 20 and the permanent magnet 40 are both connected to the housing 10. The permanent magnet 40 is disposed on one side of the diaphragm 20 along the thickness direction. One end of the voice coil 30 is connected to the diaphragm 20, and the other end is located in the magnetic gap.

[0076] In this example, the diaphragm 20 may be a surround diaphragm. The surround diaphragm comprises a central portion, a surround portion, and a fixed portion, connected in sequence from the inside out. The fixed portion is used to connect to the housing 10. A dome is provided on the central portion, and the voice coil 30 is connected to the central portion or the dome.

[0077] In other examples, the diaphragm 20 may also be a planar diaphragm or other structures. Those skilled in the art may determine this according to actual conditions, and no specific limitation is made here.

[0078] According to yet another embodiment of the present invention, an electronic device is provided.

[0079] The electronic device is, for example, a mobile phone, a computer, a television, a speaker, an intercom, a VR device, an AR device, smart glasses, etc. The electronic device includes the sound-generating device 100 described in the above embodiment. Of course, the electronic device of the present invention also includes at least all the beneficial effects of the above embodiment, which will not be described in detail here.

[0080] The diaphragm 20 and the sound generating device 100 of the present invention are described in detail below with reference to specific embodiments. It should be noted that the following description is merely exemplary and does not specifically limit the present invention.

[0081] (1) Density and elongation at break of the conductive portion 22 with different conductive material contents The conductive part 22 includes AEM rubber and a conductive material of a ternary structure. The conductive material includes a first silver wire and a second silver wire. The length of the first silver wire is 5μm-8μm, the length of the second silver wire is 9μm-15μm, and the diameter of the first silver wire and the second silver wire is 1μm-2μm. The thickness of the conductive part 22 is 100μm and is formed by air pressure. The content of the conductive material in the conductive part 22 is the percentage of the mass of the conductive material to the total mass of the conductive part 22. Among them, the content of the first silver wire is 5wt%. The elongation at break is carried out in accordance with the ASTM-D882 standard. The test results are shown in Table 1.

[0082] Table 1 - Density and elongation at break of the conductive portion 22 with different conductive material contents

[0083] As shown in Table 1, because the density of the conductive material is much greater than that of the AEM rubber, as the conductive material content in the conductive portion 22 gradually increases, the density of the conductive portion 22 gradually increases, and the maximum amplitude that the diaphragm 20 containing the conductive portion 22 can achieve under the same thrust gradually decreases. At the same time, as the conductive material content in the conductive portion 22 gradually increases, the AEM rubber content in the conductive portion 22 gradually decreases, resulting in a gradual decrease in the elongation at break of the conductive portion 22 and a gradually increasing risk of the conductive portion 22 breaking during vibration.

[0084] (2) Effect of the different mass content ratios of the second silver wire and the first silver wire on the surface resistivity of the conductive portion 22 The conductive part 22 includes AEM rubber and a conductive material of a ternary structure, and is formed by air pressure. The conductive material includes a first silver wire and a second silver wire. The length of the first silver wire is 5μm-8μm, the length of the second silver wire is 9μm-15μm, and the diameter of the first silver wire and the second silver wire is 1μm-2μm. The thickness of the conductive part 22 is 100μm. The content of silver wire in the conductive part 22 is the percentage of the mass of the silver wire to the total mass of the conductive part 22, wherein the content of silver wire in the conductive part 22 accounts for 80wt% of the mass percentage of the conductive part. The surface resistivity of the conductive part 22 with different second silver wire contents was tested, and the test results are shown in Table 2.

[0085] Table 2 - Effects of different mass ratios of the second silver wire to the first silver wire on the surface resistivity and elongation at break of the conductive portion 22

[0086] As can be seen from Table 2, as the content of the second silver wire increases, the surface resistivity of the conductive part 22 gradually decreases. This is mainly because the second silver wire with a longer length is more likely to form a continuous conductive network, reducing the contact resistance of the conductive part 22. Therefore, as the content of the second silver wire increases, the surface resistivity of the conductive part 22 gradually decreases. However, too much second silver wire content may lead to uneven dispersion and a decrease in the elongation at break of the conductive part 22. The first silver wire with a shorter length is not easy to form a continuous conductive network, but as the amount of the first silver wire added increases, the elongation at break of the conductive part also increases. Therefore, in the embodiment of the present invention, the mass content ratio of the second silver wire to the first silver wire is within the above range, which can ensure that the conductive part 22 has a lower resistivity and a higher elongation at break.

[0087] (3) Mass change rate and volume change rate of the conductive portion 22 with different conductive material contents The conductive part 22 includes AEM rubber and conductive material of a ternary structure, and is formed by air pressure. The conductive material includes a first silver wire and a second silver wire. The length of the first silver wire is 5μm-8μm, the length of the second silver wire is 9μm-15μm, and the diameter of the first silver wire and the second silver wire is 1μm-2μm. The thickness of the conductive part 22 is 100μm. The content of the conductive material in the conductive part 22 is the percentage of the mass of the conductive material to the total mass of the conductive part 22. The mass ratio of the second silver wire to the first silver wire is 10:1. The conductive part 22 is immersed in ethyl acetate solution for 50 hours, and the mass change rate and volume change rate of the conductive part 22 before and after immersion are measured. The test results are shown in Table 3.

[0088] Table 3 - Mass change rate and volume change rate of the conductive portion 22 with different contents of conductive materials

[0089] After the conductive part 22 was immersed in the ethyl acetate solution for 50 hours, the mass and volume of the conductive part 22 decreased. As can be seen from Table 3, as the content of the conductive material in the conductive part 22 increases, the mass change rate and volume change rate of the conductive part 22 gradually decrease. This is mainly because the conductive material silver wire is an inorganic material. The silver wire itself has excellent chemical stability. The silver wire in the conductive part 22 reduces the effective contact area between the substrate and the ethyl acetate solvent, thereby significantly improving the solvent resistance of the diaphragm 20. As the content of the conductive material in the conductive part 22 increases, the effective contact area between the substrate and the ethyl acetate solvent decreases, and the mass change rate and volume change of the conductive part 22 decrease. The better the solvent resistance of the diaphragm 20, the better the chemical stability. However, if the content of the conductive material in the conductive part 22 is too high, the conductive part will be easily broken.

[0090] (4) Change rate of elastic modulus of conductive portion 22 with different conductive material contents The conductive part 22 includes AEM rubber and conductive material of a ternary structure, and is formed by air pressure. The conductive material includes a first silver wire and a second silver wire. The length of the first silver wire is 5μm-8μm, the length of the second silver wire is 9μm-15μm, and the diameter of the first silver wire and the second silver wire is 1μm-2μm. The thickness of the conductive part 22 is 100μm. The content of conductive material in the conductive part 22 is the percentage of the mass of the conductive material to the total mass of the conductive part 22. The mass ratio of the second silver wire to the first silver wire is 10:1. The elastic modulus of the conductive part 22 is tested before and after being placed in a high temperature and high humidity environment for a set time. The elastic modulus is tested in accordance with the ASTM-D882 standard. The temperature is 90°C, the humidity is 60%, and the placement time is 16h. The test results are shown in Table 4.

[0091] Table 4 - Change rate of elastic modulus of conductive portion 22 with different conductive material contents

[0092] The elastic modulus of the conductive portion 22 after being placed under a high temperature and high humidity environment all decreases compared to the elastic modulus before being placed. As can be seen from Table 4, along with the increase of the content of the conductive material in the conductive portion 22, the rate of change of the elastic modulus of the conductive portion 22 decreases gradually. This is mainly due to the high strength of the silver wire, which can not decompose under high temperature and high humidity conditions, so the elastic modulus variation of the conductive portion 22 under high temperature and high humidity conditions is small. The larger the content of the conductive material in the conductive portion 22, the smaller the variation of the elastic modulus, so along with the increase of the content of the conductive material in the conductive portion 22, the rate of change of the elastic modulus of the conductive portion 22 decreases gradually. But the excessively high content of the conductive material in the conductive portion 22 can cause the conductive portion 22 to break easily.

[0093] (5) Impedance curves of the embodiment diaphragm 20 and the comparative example diaphragm 20 Example: The diaphragm 20 includes a main body 21 and a conductive part 22, which are formed by air pressure. The conductive part 22 is provided in a part of the main body 21, and the two are bonded together. The thickness of the main body 21 is 75μm, and the thickness of the conductive part 22 is 90μm. The conductive part 22 includes a matrix and a conductive material dispersed in the matrix. The conductive material includes a first silver wire and a second silver wire. The length of the first silver wire is 5μm-8μm, the length of the second silver wire is 9μm-15μm, and the diameter of the first silver wire and the second silver wire is 1μm-2μm. The matrix of the main body 21 and the conductive part 22 is AEM rubber with a ternary structure. The content of the first silver wire in the conductive part 22 is 5.16wt%. The content of the second silver wire in the conductive part 22 is 74.84wt%.

[0094] Comparative Example: The diaphragm 20 includes a main body 21 and a conductive part 22, and is formed by air pressure. The conductive part 22 is provided in a part of the main body 21, and the two are bonded together. The thickness of the main body 21 is 75 μm, and the thickness of the conductive part 22 is 90 μm. The conductive part 22 includes a matrix and a conductive material dispersed in the matrix, and the conductive material only includes a second silver wire, the length of the second silver wire is 9 μm-15 μm, and the diameter of the second silver wire is 1 μm-2 μm. The matrix of the main body 21 and the conductive part 22 are both AEM rubber with a ternary structure. The content of the second silver wire in the conductive part 22 is 80 wt%. The diaphragms 20 of the comparative example and the embodiment are both ring-shaped diaphragms, and the two have the same size.

[0095] Test items: Ten samples of each example and comparative example were tested for surface resistivity, elongation at break, and impedance versus frequency curves of the conductive portion 22 of the diaphragm 20. The surface resistivity and elongation at break were averaged. The impedance curve was tested using an impedance analyzer. The diaphragm 20 was assembled into a sound-generating device, which was then connected to the analyzer. A 3V voltage was applied, and the analyzer automatically performed a frequency sweep test, outputting an impedance curve.

[0096] The surface resistivity of the conductive portion 22 of the embodiment diaphragm 20 was 0.04 Ω·cm, while that of the comparative diaphragm 20 was 0.008 Ω·cm. The elongation at break of the conductive portion 22 of the embodiment diaphragm 20 was 185%, while that of the comparative diaphragm 20 was 97%.

[0097] The impedance variation curves of the diaphragm 20 of the embodiment of the present invention and the diaphragm 20 of the comparative example as a function of frequency are shown in FIG. Figure 4 and Figure 5 .Depend on Figure 4 、 Figure 5 It can be seen that the impedance curves of the 10 samples of the comparative diaphragm 20 are distributed more dispersedly, while the impedance curves of the 10 samples of the diaphragm 20 according to the embodiment of the present invention are distributed more concentratedly. This is mainly because the conductive part 22 of the comparative diaphragm 20 only contains a second silver wire with a longer length. During the large-amplitude vibration process, the second silver wire is prone to breakage, resulting in an increase in surface resistivity. Therefore, the vibration stability of the comparative diaphragm 20 is poor, resulting in a dispersed distribution of the impedance curves of different samples. The conductive part 22 of the diaphragm 20 according to the embodiment of the present invention includes a first silver wire with a shorter length and a second silver wire with a longer length. The content of the second silver wire with a longer length is relatively small, and the mechanical properties of the first silver wire with a shorter length are relatively stable and not easy to bend or break. It can ensure that the elongation at break of the conductive part 22 is high and the surface resistivity of the diaphragm 20 changes little, so that the impedance curves of different samples are distributed more concentratedly, and the diaphragm 20 according to the embodiment of the present invention has high stability.

[0098] In summary, although the surface resistivity of the comparative diaphragm 20 is lower than that of the embodiment of the present invention, because the conductive portion 22 of the comparative diaphragm 20 contains only the longer second silver filaments, the second silver filaments are prone to breakage during large-amplitude vibration, increasing the surface resistivity of the diaphragm 20. Furthermore, the comparative conductive portion 22 has a low elongation at break, resulting in poor vibration stability. In contrast, the conductive portion 22 of the diaphragm 20 of the embodiment of the present invention, because it includes a mixture of shorter first silver filaments and longer second silver filaments, maintains a high elongation at break. This results in high vibration stability, minimal variation in the surface resistivity of the diaphragm 20, and a concentrated impedance curve distribution across multiple samples.

[0099] 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.

[0100] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood 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 should be understood by those skilled in the art that modifications may be made to the above embodiments 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 diaphragm for a sound-generating device, characterized in that: The invention comprises a main body and a conductive part, wherein the conductive part is provided in the main body, and at least a portion of the conductive part is exposed from the main body to be electrically connected to the voice coil of the sound-generating device and an external circuit. The conductive part comprises a substrate and a conductive material dispersed in the substrate, wherein the conductive material comprises a first silver wire and a second silver wire, wherein the length of the first silver wire is 5 μm-8 μm, the length of the second silver wire is 9 μm-15 μm, the diameter of the first silver wire and the second silver wire is 1 μm-2 μm, the mass percentage of the conductive material in the conductive part is 50%-90%, and the surface resistivity of the conductive part is 5*10 ⁻1 Ω·cm -10 ⁻2 Ω·cm, and the elongation at break of the conductive portion is ≥80%.

2. The diaphragm according to claim 1, wherein In the conductive material, a mass ratio of the second silver wire to the first silver wire is α, wherein 7 / 3≤α≤19 / 1.

3. The diaphragm according to claim 1, wherein The purity of the first silver wire and / or the second silver wire is ≥99.99%.

4. The diaphragm according to claim 1, wherein The matrix includes ethylene-acrylate rubber, and the molecular formula of the ethylene-acrylate rubber is: Wherein, x, y are natural numbers; R is an alkyl group; and / or, Wherein, x, y, and z are natural numbers; R and R' are alkyl groups.

5. The diaphragm according to claim 1, wherein After being placed under the conditions of a temperature of 90° C. and a humidity of 60% for 16 hours, the elastic modulus change rate of the conductive portion is ≤8.7%.

6. The diaphragm according to claim 1, wherein: The mass change rate of the diaphragm after being immersed in ethyl acetate solvent for 50 hours is ≤15%.

7. The diaphragm according to claim 1, wherein: The matrix further includes a filler, the filler includes an antioxidant, the antioxidant includes one or more of antioxidant N-445, antioxidant 246, and antioxidant 4010, and the weight percentage of the antioxidant in the conductive portion is 0.1%-6%; And / or, the matrix further includes a crosslinking agent, which is at least one of metal oxides, metal peroxides, organic oxides, organic peroxides, and amine vulcanization systems, and in the conductive portion, the mass percentage of the crosslinking agent is 1%-7%.

8. The diaphragm according to claim 1, wherein: The tensile strength of the conductive portion when broken is 2 MPa-10 MPa; and / or the tensile strength of the first silver wire and / or the second silver wire is 100 MPa-200 MPa.

9. The diaphragm according to claim 1, wherein: The room temperature storage modulus of the conductive part is 100 MPa-200 MPa.

10. The diaphragm according to claim 1, wherein: The glass transition temperature of the diaphragm is ≤-10°C.

11. The diaphragm according to claim 1, wherein: The main body portion includes polyacrylate rubber.

12. A sound-generating device, characterized in that: Comprising a diaphragm as described in any one of claims 1-11.

13. An electronic device, characterized in that: Comprising the sound-generating device as claimed in claim 12.

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