Vibrating diaphragm assembly, sound production device and electronic equipment

Abstract

The invention belongs to the technical field of electroacoustics, and particularly relates to a vibrating diaphragm assembly, a sound production device and electronic equipment, the vibrating diaphragm assembly comprises a vibrating diaphragm, a globe roof and a bonding layer arranged between the vibrating diaphragm and the globe roof, the bonding layer comprises a temperature-resistant improving filler and a thermoplastic bonding material, and the temperature-resistant improving filler is arranged between the temperature-resistant improving filler and the thermoplastic bonding material. The temperature-resistant improving filler accounts for 0.5%-10% of the total mass of the bonding layer, and the ejection force of the vibrating diaphragm assembly per unit area is 5N-25N under the condition of 25 DEG C; the loss rate of the ejection force of the vibrating diaphragm assembly per unit area under the condition of 120 DEG C is 20%-60% compared with the ejection force under the condition of 25 DEG C. According to the vibrating diaphragm assembly, the bonding layer is provided with the temperature-resistant improving filler and the thermoplastic bonding material, so that the heat resistance of the bonding layer is remarkably improved, the normal-temperature mechanical property of the bonding layer is improved, and the working stability of the vibrating diaphragm assembly in a high-temperature state is improved.

Description

Technical Field

[0001] The present invention belongs to the field of electroacoustic technology, and in particular relates to a diaphragm assembly, a sound-generating device and an electronic device. Background Art

[0002] The diaphragm and the dome of the diaphragm assembly of the sound-generating device are usually fixed by an adhesive layer. The main resin of the adhesive layer is mostly polyurethane, acrylic acid, polystyrene, polyacrylate and ethylene-vinyl acetate copolymer, etc. The long-term working temperature of the main resin is below 100°C.

[0003] As the speaker power and voltage increase, the voice coil does more work, the heat generated increases significantly, and the heat cannot be dissipated in time. The product temperature can reach over 130°C, so the temperature resistance of the diaphragm assembly becomes particularly important. However, due to the poor temperature resistance of the existing adhesive layer, the main resin molecular chain of the adhesive layer breaks and the cross-linking structure changes in the long-term high temperature environment, thereby reducing the bonding strength between the diaphragm and the dome, and further affecting the sound performance of the sound device.

[0004] To this end, the present invention is proposed. Summary of the invention

[0005] The main purpose of the present invention is to provide a diaphragm assembly, a sound-emitting device and an electronic device. The bonding layer in the diaphragm assembly of the present invention has a temperature-resistant improved filler and a thermoplastic bonding material, which significantly improves the heat resistance of the bonding layer, improves the room-temperature mechanical properties of the bonding layer, and enhances the working stability of the diaphragm assembly in a high-temperature state.

[0006] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0007] According to a first aspect of the present invention, a diaphragm assembly is provided, which includes a diaphragm, a dome, and a bonding layer disposed between the diaphragm and the dome, the bonding layer including a temperature-resistant improvement filler and a thermoplastic bonding material, the mass percentage of the temperature-resistant improvement filler in the total mass of the bonding layer is 0.5% to 10%, and at 25°C, the ejection force per unit area of ​​the diaphragm assembly is 5N to 25N; the ejection force per unit area of ​​the diaphragm assembly at 120°C is 20% to 60% of the ejection force at 25°C.

[0008] In some embodiments of the present invention, at 25° C., the ejection force per unit area of ​​the diaphragm assembly is 10N to 25N.

[0009] In some embodiments of the present invention, at 120° C., the ejection force per unit area of ​​the diaphragm assembly is ≥5N.

[0010] In some embodiments of the present invention, the mass percentage of the temperature resistance improving filler in the bonding layer is 1% to 3%.

[0011] In some embodiments of the present invention, at 120° C., the thermal shrinkage rate of the temperature-resistant improving filler is ≤0.5%.

[0012] In some embodiments of the present invention, after being treated at 120° C. for 3 hours, the thickness shrinkage rate of the adhesive layer is ≤3%.

[0013] In some embodiments of the present invention, the thickness of the adhesive layer is 10 μm to 100 μm.

[0014] In some embodiments of the present invention, the thickness of the diaphragm assembly is 60 μm to 300 μm.

[0015] In some embodiments of the present invention, at 25° C., the elastic modulus of the adhesive layer is 15 MPa to 900 MPa.

[0016] In some embodiments of the present invention, the diaphragm and the dome are bonded together through the bonding layer at a bonding temperature of 100° C. to 200° C. and a bonding time of 5 s to 60 s.

[0017] In some embodiments of the present invention, the temperature resistance improving filler is selected from at least one of inorganic microspheres and inorganic fibers; and / or the thermoplastic adhesive material is selected from at least one of modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymers, modified styrene-butadiene-styrene block copolymers, polyesters, polyolefins and polyurethanes.

[0018] In some embodiments of the present invention, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is obtained by grafting a polystyrene-poly(ethylene-butylene)-polystyrene block copolymer with an epoxy compound.

[0019] In some embodiments of the present invention, the epoxy compound is selected from at least one of glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, and 2,3-epoxypropyltrimethylammonium chloride.

[0020] In some embodiments of the present invention, the inorganic microspheres are selected from at least one of aluminum hydroxide, aluminum oxide, iron oxide, corundum, calcium carbonate, glass hollow microspheres, ceramic hollow microspheres, nano-silicon dioxide, nano-calcium oxide, and zinc oxide.

[0021] In some embodiments of the present invention, the inorganic fiber is selected from at least one of quartz fiber, aluminum silicate fiber, and zirconium oxide fiber.

[0022] In some embodiments of the present invention, the form of the temperature resistance improving filler includes at least one of flake, granular, and powder.

[0023] In some embodiments of the present invention, the material of the diaphragm is selected from at least one of engineering plastics and elastomeric materials; and / or the material of the dome is selected from at least one of carbon fiber, aluminum metal, aluminum-based composite materials and engineering plastics.

[0024] A second aspect of the present invention provides a sound-generating device, wherein the sound-generating device comprises the diaphragm assembly described in the first aspect.

[0025] According to a third aspect of the present invention, an electronic device is provided. The electronic device includes the sound-generating device according to the second aspect.

[0026] Compared with the prior art, the present invention achieves the following technical effects:

[0027] The adhesive layer in the diaphragm assembly of the present invention comprises a temperature-resistant improving filler and a thermoplastic adhesive material, which significantly improves the heat resistance of the adhesive layer, improves the room-temperature mechanical properties of the adhesive layer and the working stability of the diaphragm assembly in a high-temperature state.

[0028] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference numerals are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 is a cross-sectional view of a diaphragm assembly according to some embodiments of the present invention;

[0031] Figure 2 is a cross-sectional view of a sound-generating device according to some embodiments of the present invention;

[0032] Figure 3 Schematic diagram of THD curves of the speakers corresponding to the diaphragm assemblies in Example 2 and Comparative Example 2.

[0033] Reference numerals

[0034] 100, diaphragm assembly;

[0035] 110, diaphragm; 120, dome; 130, bonding layer;

[0036] 200. Sound-generating device;

[0037] 210, housing; 220, magnetic circuit system; 230, voice coil. DETAILED DESCRIPTION

[0038] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0040] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0041] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0044] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention.

[0045] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0046] The temperature resistance of the adhesive layer in the existing diaphragm assembly is poor. When the diaphragm assembly works in a high temperature environment for a long time, it will lead to the breakage of the main resin molecular chain of the adhesive layer and the change of the cross-linking structure, thereby reducing the bonding strength and sound performance between the diaphragm and the dome.

[0047] The present invention provides a diaphragm assembly, such as Figure 1 As shown, the diaphragm assembly 100 includes a diaphragm 110, a dome 120 and an adhesive layer 130 disposed between the diaphragm 110 and the dome 120, the adhesive layer 130 includes a temperature-resistant improvement filler and a thermoplastic adhesive material, the mass percentage of the temperature-resistant improvement filler in the total mass of the adhesive layer is 0.5% to 10%, thereby improving the temperature resistance of the adhesive layer 130, and at 25°C, the ejection force per unit area of ​​the diaphragm assembly is 5N to 25N; the ejection force per unit area of ​​the diaphragm assembly at 120°C is 20% to 60% of the ejection force at 25°C.

[0048] The bonding layer in the present invention contains a temperature-resistant improvement filler and a thermoplastic bonding material. The temperature-resistant improvement filler has a high melting point, can be used in a high-temperature environment for a long time, and meets certain dimensional change requirements. On the basis of maintaining its original performance, the heat resistance of the bonding layer can also be significantly improved. Adding a temperature-resistant improvement filler to the bonding layer is beneficial to improving the room-temperature mechanics of the bonding layer and the performance of the bonding layer under high-temperature conditions, and improving the working stability of the diaphragm assembly under high-temperature conditions. The mass percentage of the temperature-resistant improvement filler to the total mass of the bonding layer is 0.5% to 10%. If the amount of the temperature-resistant improvement filler added is less than 0.5%, the temperature resistance improvement effect is not obvious; when the amount of the temperature-resistant improvement filler added is greater than 10%, the volume density of the bonding layer increases, affecting the bonding effect of the bonding layer, reducing the ejection force of the diaphragm assembly, and thus reducing product reliability.

[0049] In an embodiment of the invention, the mass percentage of the heat-resistant improving filler in the adhesive layer is 1% to 3%. This further improves the heat resistance of the adhesive layer, and improves the room temperature mechanical and high temperature performance of the adhesive layer. Exemplarily, the mass percentage of the heat-resistant improving filler in the adhesive layer can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or any value that meets the above range.

[0050] The ejection force of the adhesive layer in the present invention represents the magnitude of the adhesive force between the diaphragm and the dome. When the ejection force is small, the adhesive force between the diaphragm and the dome is small, and the product reliability is low. In the embodiment of the present invention, the adhesive layer has good temperature resistance. At 25°C, the ejection force per unit area of ​​the diaphragm assembly is 5N to 25N. At 120°C, the ejection force per unit area of ​​the diaphragm assembly is ≥5N. The ejection force per unit area of ​​the diaphragm assembly at 120°C is 20% to 60% of the ejection force at 25°C. Thus, a diaphragm assembly with higher reliability is obtained. For example, at 25°C, the ejection force per unit area of ​​the diaphragm assembly may be one of 5N, 6N, 7N, 8N, 9N, 10N, 11N, 12N, 13N, 14N, 15N, 16N, 17N, 18N, 19N, 20N, 21N, 22N, 23N, 24N, 25N, or any value within the above range. The loss rate of the ejection force per unit area of ​​the diaphragm assembly at 120°C compared to the ejection force at 25°C may be one of 20%, 30%, 40%, 50%, 60%, or any value within the above range.

[0051] In some embodiments of the present invention, at 25° C., the ejection force per unit area of ​​the diaphragm assembly may be 10 N to 25 N. This further improves the bonding force between the diaphragm and the dome, and obtains a diaphragm assembly with higher reliability.

[0052] In an embodiment of the present invention, the temperature resistance improving filler is selected from at least one of inorganic microspheres and inorganic fibers, thereby improving the high temperature resistance of the bonding layer.

[0053] In some embodiments of the present invention, the form of the temperature resistance improving filler includes at least one of flake, granular, and powder.

[0054] In some embodiments of the present invention, the inorganic microspheres are selected from at least one of aluminum hydroxide, aluminum oxide, iron oxide, corundum, calcium carbonate, glass hollow microspheres, ceramic hollow microspheres, nano-silicon dioxide, nano-calcium oxide, and zinc oxide.

[0055] In some embodiments of the present invention, the inorganic fiber is selected from at least one of quartz fiber, aluminum silicate fiber, and zirconium oxide fiber, and the characteristics of the inorganic fiber such as light weight, low thermal conductivity, and high temperature resistance are fully utilized to improve the high temperature resistance of the bonding layer.

[0056] In an embodiment of the present invention, the thermoplastic bonding material is selected from at least one of modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymers, modified styrene-butadiene-styrene block copolymers, polyesters, polyolefins and polyurethanes. Copolyester bonding materials are widely used because of their high viscosity, rapid curing, low shear rate and viscosity, and can effectively transfer loads when subjected to pressure, thereby ensuring the strength and durability of bonding. Copolyesters can be polymer compounds formed by the reaction of diols and dibasic acids or polyols and polyacids, and copolyesters include aliphatic copolyesters, aromatic copolyesters, aliphatic-aromatic copolyesters and other novel copolyesters. Polyolefins are based on the combination of chemical bonds and physical adsorption. Through heating and pressure, the surface of the polyolefin and the surface of the adherend are subjected to the effects of high temperature and pressure, thereby achieving firm bonding. Polyurethane has excellent shear strength and impact resistance, and can adapt to the bonding of substrates with different thermal expansion coefficients. In addition, it can make the bonding surface swell, and the molecular chain segments of the polyurethane penetrate into the surface of the bonding surface to form covalent bonds, thus having good bonding properties.

[0057] In an embodiment of the present invention, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is obtained by grafting reaction of polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (SEBS) with epoxy compounds. SEBS has low density, good weather resistance, heat resistance, compression deformation resistance, excellent mechanical properties, aging resistance and elastomeric properties that can be used without vulcanization. SEBS and epoxy compounds are grafted to obtain epoxy groups, and the epoxy groups and the temperature-resistant improvement fillers generate intermolecular van der Waals forces. While fixing the temperature-resistant improvement fillers, they can also form a certain degree of hydrogen bonds with the diaphragm. At the bonding temperature, the epoxy group will produce a "ring-opening" reaction, thereby obtaining a higher bonding force through intramolecular covalent bonds.

[0058] In an embodiment of the present invention, the epoxy compound is at least one selected from glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, and 2,3-epoxypropyltrimethylammonium chloride.

[0059] In the present invention, SEBS grafting is a free radical reaction, in which monomers and oligomers are grafted onto the SEBS molecular chain, and the grafting position is on the unhydrogenated double bonds. Taking the grafting reaction of SEBS and glycidyl methacrylate as an example, the grafting reaction principle is shown in the following formula (1).

[0060]

[0061] In some embodiments of the present invention, the material of the diaphragm is selected from at least one of engineering plastics and elastomeric materials. For example, the material of the diaphragm can be a composite of one or more materials selected from polyetheretherketone (PEEK), polyimide (PI), thermoplastic polyurethane elastomer rubber (TPU), thermoplastic polyester elastomer (TPEE), rubber, etc.

[0062] In some embodiments of the present invention, the material of the dome is selected from at least one of carbon fiber, aluminum metal, aluminum-based composite materials and engineering plastics. For example, the material of the dome can be one of carbon fiber, aluminum metal, aluminum-based composite materials, polyetheretherketone (PEEK), and polyimide (PI).

[0063] The high-temperature dimensional shrinkage rate of the temperature-resistant improved filler in the present invention is an important performance indicator, which is directly related to the dimensional stability and reliability of the diaphragm assembly in practical applications. A high shrinkage rate means that the material will undergo significant volume shrinkage in a high-temperature environment, resulting in a decrease in the dimensional stability of the diaphragm assembly. In applications in the acoustic field that require precise dimensional control, dimensional changes affect the assembly and performance of the product. Secondly, a high high-temperature dimensional shrinkage rate may affect the bonding strength of the adhesive layer. In a high-temperature environment, excessive shrinkage may cause stress concentration, reduce the strength and toughness of the adhesive layer, and thus affect the durability of the diaphragm assembly. In an embodiment of the present invention, at 120°C, the thermal shrinkage rate of the temperature-resistant improved filler is in the range of 0 to 2%. Exemplarily, the thermal shrinkage rate of the temperature-resistant improved material is one of 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, or any value that meets the above range.

[0064] In some embodiments of the present invention, at 120° C., the heat shrinkage rate of the temperature-resistant improved filler is ≤0.5%, for example, in the range of 0 to 0.5%, thereby improving the dimensional stability and reliability of the diaphragm assembly.

[0065] The dimensional stability of the adhesive layer in the present invention is crucial to the performance of the diaphragm assembly, and directly affects the sound transmission quality and the service life of the diaphragm assembly. The thickness change of the adhesive layer at high temperature will weaken the bonding strength, reduce heat resistance, increase fluidity, and affect the size change of the product, resulting in discrete data on the product frequency response and sensitivity, affecting the sound transmission quality and the service life of the diaphragm assembly. In an embodiment of the present invention, after baking at 120°C for 3 hours, the thickness shrinkage rate of the adhesive layer is ≤3%, for example, the thickness shrinkage rate of the adhesive layer is 0 to 3%. Exemplarily, after baking at 120°C for 3 hours, the thickness shrinkage rate of the adhesive layer can be one of 0%, 1%, 2%, 3%, or any value that satisfies the above range.

[0066] The calculation of the shrinkage rate of the adhesive layer thickness in the present invention is as follows:

[0067] ((initial thickness of the adhesive layer - thickness of the adhesive layer after baking at 120° C. for 3 hours) / initial thickness)*100%.

[0068] In some embodiments of the present invention, after baking at 120° C. for 3 hours, the thickness shrinkage rate of the adhesive layer is 0-1%, thereby further improving the dimensional stability of the adhesive layer and the reliability of the diaphragm assembly.

[0069] In the present invention, the thickness of the adhesive layer needs to be appropriate, and the thickness of the adhesive layer is 10μm to 100μm. If the thickness of the adhesive layer is greater than 100μm, the vibration space of the sound-generating device such as a speaker is reduced, and the maximum amplitude that can be achieved is reduced, thereby affecting the sound effect; and if the thickness of the adhesive layer is less than 10μm, the ejection force of the diaphragm assembly is low, resulting in reduced reliability and efficiency of the speaker. Exemplarily, the thickness of the adhesive layer can be one of 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, or any value that meets the above range.

[0070] In some embodiments of the present invention, the thickness of the adhesive layer may be 20 μm to 40 μm, thereby further improving the reliability of the diaphragm assembly.

[0071] In some embodiments of the present invention, the thickness of the diaphragm assembly may be 60 μm to 300 μm. For example, the thickness of the diaphragm assembly may be 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm or any value satisfying the above range.

[0072] The elastic modulus of the adhesive layer in the present invention refers to the ability to resist deformation when deformed by force. In an embodiment of the present invention, the elastic modulus of the adhesive layer is 15MPa to 900Mpa at 25°C. If the modulus of the adhesive layer is less than 15MPa, the adhesive layer body may crack when the sound-emitting device such as a speaker works for a long time; and if the elastic modulus of the adhesive layer is greater than 900Mpa, greater stress may be caused during the speaker production process, leading to stress concentration, especially when excessive pressure is applied, which may cause the diaphragm to deform or rupture. Illustratively, at 25°C, the elastic modulus of the adhesive layer can be one of 15MPa, 20MPa, 30MPa, 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, 100MPa, 150MPa, 200MPa, 250MPa, 300MPa, 350MPa, 400MPa, 450MPa, 500MPa, 550MPa, 600MPa, 650MPa, 700MPa, 750MPa, 800Mpa, 850Mpa, 900MPa or any value that meets the above range.

[0073] In some embodiments of the present invention, the elastic modulus of the adhesive layer is 20 MPa to 100 MPa at 25° C. This further improves the anti-deformation capability of the adhesive layer and the reliability of the diaphragm assembly.

[0074] The bonding temperature between the diaphragm and the dome in the present invention, that is, the bonding temperature of the bonding layer, directly affects the bonding efficiency of the bonding layer. In an embodiment of the present invention, the bonding temperature of the diaphragm and the dome through the bonding layer is 100°C to 200°C. If the bonding temperature is less than 100°C, the viscosity of the bonding layer is high and the fluidity is poor, and it cannot fully penetrate into the gaps of the adhered objects, resulting in a slower bonding speed and poorer bonding effect. If the temperature is greater than 200°C, the bonding layer will undergo thermal decomposition, and the diaphragm will also be damaged, affecting the flatness of the diaphragm. Exemplarily, the bonding temperature can be one of 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, or any value that satisfies the above range.

[0075] In some embodiments of the present invention, the bonding temperature of the diaphragm and the dome through the bonding layer may be 150° C. to 180° C. This further achieves better bonding effect and bonding efficiency.

[0076] In an embodiment of the present invention, the bonding time may be 5s to 60s, thereby achieving a better bonding effect. Exemplarily, the bonding time may be one of 5s, 6s, 7s, 8s, 9s, 10s, 15s, 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55s, 60s, or any value satisfying the above range.

[0077] The present invention also provides a sound-generating device, which includes a diaphragm assembly according to any of the above embodiments. Since the diaphragm assembly in the present invention has the advantage of high reliability, it can improve the sound quality of the sound-generating device, thereby improving the overall stability and sound-generating effect of the sound-generating device.

[0078] The diaphragm assembly provided by the present invention can be used to form a sound-generating device of any structure, such as the following typical sound-generating devices: Figure 2 As shown, the sound-generating device 200 may be a speaker, which includes a housing 210, a vibration system disposed in the housing 210, and a magnetic circuit system 220 matched with the vibration system, wherein the vibration system includes a diaphragm assembly 100 and a voice coil 230 coupled to one side of the diaphragm assembly 100. When the sound-generating device 200 is working, after the voice coil 230 is energized, under the action of the magnetic field force of the magnetic circuit system 220, the voice coil 230 may vibrate up and down to drive the diaphragm assembly 100 to generate sound.

[0079] The present invention also provides an electronic device having a sound-generating device according to any of the above embodiments. The electronic device has a sound-generating device 200, thereby achieving the advantages of high stability and reliability of the electronic device and improved sound-generating effect. Optionally, the electronic device can be a mobile phone, a PAD, a laptop computer, a television, or a smart wearable device.

[0080] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the amounts of the experimental reagents, unless otherwise specified, are the amounts of reagents used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0081] The following describes the diaphragm assembly and the sound-generating device of the present invention in detail with specific embodiments and comparative examples. It is worth noting that the following description is only exemplary and does not specifically limit the present invention. Moreover, the comparative examples are selected to reflect the technical progress of the main technical points of the present invention by comparison with the embodiments, and the comparative examples are not all prior art in the field.

[0082] Example 1

[0083] A diaphragm assembly is disclosed, see Figure 1 As shown, the diaphragm assembly 100 includes a diaphragm 110, a dome 120, and an adhesive layer 130 disposed between the diaphragm 110 and the dome 120. The adhesive layer 130 is annular and has a thickness of 30 μm. The diaphragm 110 is made of ethylene acrylate rubber, the dome 120 is made of aluminum composite material, and the adhesive layer 130 is 1% by mass of nano calcium oxide + epoxy group-modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The epoxy group-modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is obtained by grafting polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (SEBS) with glycidyl methacrylate.

[0084] The process of bonding the diaphragm 110 and the dome 120 via the bonding layer 130 is as follows: firstly bonding one side of the bonding layer 130 to the dome 120 , and then hot pressing the other side of the bonding layer 130 to the diaphragm 110 at 180° C. for 20 seconds.

[0085] Example 2

[0086] The remaining operations are the same as those in Example 1, except that the adhesive layer 130 is 1.5% by mass of nano calcium oxide + epoxy group-modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The epoxy group-modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is obtained by grafting polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (SEBS) with glycidyl methacrylate.

[0087] Example 3

[0088] The remaining operations are the same as those in Example 1, except that the bonding layer 130 is a nano calcium oxide + copolyester system with a mass percentage of 1.5%. The copolyester system is a copolymer system of terephthalic acid and neopentyl glycol. The copolyester bonding layer can effectively transfer the load when subjected to pressure, thereby ensuring the strength and durability of the bonding.

[0089] Comparative Example 1

[0090] The remaining operations are the same as those in Example 1, except that the adhesive layer 130 is an epoxy-modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The epoxy-modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is obtained by grafting polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (SEBS) with glycidyl methacrylate.

[0091] Comparative Example 2

[0092] The remaining operations are the same as those in Example 1, except that the adhesive layer 130 is a polyacrylate pressure-sensitive adhesive.

[0093] Ejection force test.

[0094] Ejection force test method:

[0095] a) Use tooling to fix the diaphragm assembly;

[0096] b) Install the top head under the dynamometer, and place the diaphragm assembly and the top head of the dynamometer vertically;

[0097] c) Run the dynamometer with the ejector head in vertical contact with the ball top until the diaphragm separates from the ball top or the diaphragm is damaged. Record the force value of the dynamometer, which is the ejection force value.

[0098] The calculation method of the ejection force loss rate in the present invention is as follows:

[0099] ((the ejection force of the diaphragm assembly per unit area at 25°C - the ejection force of the diaphragm assembly per unit area at 120°C) / the ejection force of the diaphragm assembly per unit area at 25°C)*100%.

[0100] Modulus of elasticity.

[0101] Elastic modulus test method: refer to standard GB / T 33061.10-2016 and use rheometer for testing.

[0102] The rheometer can record the stress changes under different strains to obtain a stress-strain curve. There is usually a linear part on the stress-strain curve, which is the linear elastic region of the material. The elastic modulus of the bonding layer can be obtained through this linear part.

[0103] The test results are shown in Table 1.

[0104] Table 1 Summary of adhesive layer properties in the examples and comparative examples

[0105]

[0106] It can be found from Table 1 that under the conditions of the same bonding area and equal bonding thickness, the addition of the temperature-resistant improved filler in the embodiment does not affect the bonding force, and achieves the high temperature resistance effect of the bonding layer. The ejection force of the diaphragm assembly in Example 1 at 120°C is 46% greater than the ejection force of the diaphragm assembly in Comparative Example 1, and 78% greater than the ejection force of the diaphragm assembly in Comparative Example 2. The ejection force of the diaphragm assembly in Example 2 at 120°C is 56% greater than the ejection force of the diaphragm assembly in Comparative Example 1, and 82% greater than the ejection force of the diaphragm assembly in Comparative Example 2. The ejection force loss rate of the diaphragm assembly in Example 1 is 44%, the ejection force loss rate of the diaphragm assembly in Example 2 is 34%, and the ejection force loss rate of the diaphragm assembly in Example 3 is 48%, all of which are better than the ejection force loss rate of 68% of the diaphragm assembly in Comparative Example 1 and the ejection force loss rate of 78% of the diaphragm assembly in Comparative Example 2. The addition of the heat-resistant improved filler in the present invention increases the high-temperature ejection force of the diaphragm assembly. The heat-resistant improved filler has a high melting point and can be used in a high-temperature environment for a long time, meeting certain dimensional change requirements. On the basis of maintaining its original performance, it can also significantly improve the heat resistance of the adhesive layer.

[0107] Acoustic performance test comparison

[0108] In the present invention, the diaphragm assemblies in Example 2 and Comparative Example 2 are respectively assembled into micro-speakers of the same structure and model, and the reliability acoustic performance test of the products is carried out under a voltage of 3V and a 48h swept frequency vibration in an environment of 65°C and 95% humidity.

[0109] like Figure 3 As shown, through the total harmonic distortion curves of the speakers corresponding to Example 2 and Comparative Example 2, it can be seen that Comparative Example 2 has distortion, while the example has no problem. The product was disassembled and it was found that the bonding layer of Comparative Example 2 had cracking. This once again proves that the addition of the heat-resistant improving filler in the present invention enables the diaphragm assembly to be stably used in a high temperature environment for a long time and meets certain dimensional change requirements. On the basis of maintaining its original performance, it can also significantly improve the heat resistance of the bonding layer.

[0110] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A diaphragm assembly, characterized in that: The invention comprises a diaphragm, a dome and an adhesive layer disposed between the diaphragm and the dome, wherein the adhesive layer comprises a temperature-resistant improving filler and a thermoplastic adhesive material, and the mass percentage of the temperature-resistant improving filler in the total mass of the adhesive layer is 0.5% to 10%. At 25°C, the ejection force per unit area of ​​the diaphragm assembly is 5N to 25N; the loss rate of the ejection force per unit area of ​​the diaphragm assembly at 120°C is 20% to 60% compared with the ejection force at 25°C.

2. The diaphragm assembly according to claim 1, characterized in that: At 25°C, the ejection force per unit area of ​​the diaphragm assembly is 10N to 25N; Preferably, at 120° C., the ejection force per unit area of ​​the diaphragm assembly is ≥5N.

3. The diaphragm assembly according to claim 1, characterized in that: The mass percentage of the temperature resistance improving filler in the bonding layer is 1% to 3%; Preferably, at 120° C., the thermal shrinkage rate of the temperature-resistant improving filler is ≤0.5%.

4. The diaphragm assembly according to claim 1, characterized in that: After being treated at 120° C. for 3 hours, the thickness shrinkage rate of the adhesive layer is ≤3%; Preferably, the thickness of the adhesive layer is 10 μm to 100 μm; Preferably, the thickness of the diaphragm assembly is 60 μm to 300 μm.

5. The diaphragm assembly according to claim 1, characterized in that: At 25°C, the elastic modulus of the adhesive layer is 15MPa to 900MPa; Preferably, the diaphragm and the dome are bonded together through the bonding layer at a bonding temperature of 100° C. to 200° C. and a bonding time of 5s to 60s.

6. The diaphragm assembly according to claim 1, characterized in that: The temperature resistance improving filler is selected from at least one of inorganic microspheres and inorganic fibers; and / or, The thermoplastic adhesive material is selected from at least one of modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, modified styrene-butadiene-styrene block copolymer, polyesters, polyolefins and polyurethanes; Preferably, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is obtained by grafting a polystyrene-poly(ethylene-butylene)-polystyrene block copolymer with an epoxy compound; Preferably, the epoxy compound is selected from at least one of glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, and 2,3-epoxypropyltrimethylammonium chloride.

7. The diaphragm assembly according to claim 6, characterized in that: The inorganic microspheres are selected from at least one of aluminum hydroxide, aluminum oxide, iron oxide, corundum, calcium carbonate, glass hollow microspheres, ceramic hollow microspheres, nano silicon dioxide, nano calcium oxide, and zinc oxide; Preferably, the inorganic fiber is selected from at least one of quartz fiber, aluminum silicate fiber, and zirconium oxide fiber; Preferably, the form of the temperature resistance improving filler includes at least one of flake, granular and powder.

8. The diaphragm assembly according to claim 1, characterized in that: The material of the diaphragm is selected from at least one of engineering plastics and elastomeric materials; and / or, The material of the dome is selected from at least one of carbon fiber, aluminum metal, aluminum-based composite materials and engineering plastics.

9. A sound-generating device, characterized in that: Comprising the diaphragm assembly described in any one of claims 1-8.

10. An electronic device, characterized in that: Includes the sound-generating device as claimed in claim 9.

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