Vibrating diaphragm assembly, sound production device and electronic equipment

Abstract

The invention discloses a vibrating diaphragm assembly, a sound production device and electronic equipment. The vibrating diaphragm assembly comprises a vibrating diaphragm body and a ball top, and the vibrating diaphragm body and the ball top are integrally formed. The vibrating diaphragm body comprises at least one elastomer layer, the elastomer layer comprises a modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer and a heat-conducting filler, and the modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer contains an epoxy group. The heat-conducting filler accounts for 0.5 wt%-15 wt% of the total amount of the elastomer layer, the heat conductivity coefficient of the elastomer layer is 0.5 W / m * K-30W / m * K, and the linear expansion coefficient of the elastomer layer is 0.5 * 10 <-5 > / DEG C-80 * 10 <-5 > / DEG C. The elastomer layer can be combined with the heat-conducting filler through an intermolecular acting force to limit the deformation of the elastomer layer, so that the linear expansion coefficient can be reduced, the surface of the vibrating diaphragm body is kept flat, and the high-temperature resistance and the sound production effect of the vibrating diaphragm assembly can be improved.

Description

Technical Field

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

[0002] With the development of electronic product technology, the market competition for electronic products is becoming increasingly fierce, so the requirements for speakers in electronic products are also getting higher and higher. In terms of structure, the speaker is required to meet the requirements of lightness and thinness. In terms of acoustic performance, the speaker needs to have good mid-frequency sensitivity, suitable F0 and Fh.

[0003] In the related art, the diaphragm assembly in the speaker adopts the structure of diaphragm + adhesive layer + dome. The adhesive layer mainly has two methods: glue curing bonding and film bonding. The main resin of the adhesive layer is mostly polyurethane, acrylic acid, polystyrene, polyacrylate and ethylene-vinyl acetate copolymer. The long-term working temperature of the main resin of the adhesive layer is below 130°C, which leads to the breakage of the molecular chain of the main resin of the adhesive layer and the change of the cross-linking structure, thereby reducing its bonding strength and performance. Moreover, due to the existence of the adhesive layer, it will not only increase the weight of the diaphragm assembly and affect the sound sensitivity, but also increase the thickness of the diaphragm assembly, occupy the vibration space of the diaphragm assembly, and affect the sound effect.

[0004] In order to improve the temperature resistance of the diaphragm assembly, the existing diaphragm generally adds thermal conductive materials through mechanical stirring. During the heat transfer process, the thermal conductive material is separated from the molecular segments in the diaphragm, which reduces the flatness of the diaphragm, causes speaker distortion, and affects the loudness of the speaker diaphragm and the mid- and low-frequency sensitivity.

[0005] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the invention

[0006] An object of the present invention is to provide a new technical solution for a diaphragm assembly.

[0007] According to a first aspect of the present invention, a diaphragm assembly is provided. The diaphragm assembly comprises:

[0008] A diaphragm body and a dome, wherein the diaphragm body and the dome are integrally formed;

[0009] The diaphragm body includes at least one elastomer layer, the elastomer layer includes a modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer and a thermally conductive filler, the modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer contains an epoxy group, the thermally conductive filler accounts for 0.5wt% to 15wt% of the total amount of the elastomer layer, the thermal conductivity of the elastomer layer is 0.5W / m*K to 30W / m*K, and the linear expansion coefficient of the elastomer layer is 0.5×10 -5 / ℃~80×10 -5 / ℃.

[0010] Optionally, the thermally conductive filler accounts for 1 wt% to 5 wt% of the total weight of the elastomer layer.

[0011] Optionally, the thermally conductive filler includes at least one of a metal filler or a high thermal conductivity inorganic non-metal filler, the metal filler is at least one of aluminum, copper, silver, magnesium, tin, lead, and iron, and the non-metal filler is at least one of boron nitride, boron carbide, silicon carbide, alumina, graphite, carbon nanotubes, graphene, and nano-carbon powder.

[0012] Optionally, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer further contains benzene rings, and the molar ratio of the epoxy group to the benzene ring is 0.05% to 5%.

[0013] Optionally, the elongation at break of the elastomer layer is greater than or equal to 100% to 800%.

[0014] Optionally, the Young's modulus of the elastomer layer is 15 MPa to 700 MPa.

[0015] Optionally, the thickness of the elastomer layer is 10 μm to 300 μm; and / or the density of the elastomer layer is 0.8 g / cm 3 -1.2g / cm 3 .

[0016] Optionally, the melting temperature of the elastomer layer is 130°C to 220°C.

[0017] Optionally, the ejection force of the diaphragm assembly after baking in an environment of 130° C. for 6 hours is 10N-30N.

[0018] Optionally, the diaphragm body is formed as a single-layer structure, and the diaphragm body is composed of a layer of the elastomer layer; or, the diaphragm body is formed as a composite layer structure, and the diaphragm body includes the elastomer layer and a composite layer, and the composite layer includes engineering plastics and / or elastomer materials.

[0019] According to a second aspect of the present invention, a sound-generating device is provided. The sound-generating device comprises a vibration system and a magnetic circuit system matched with the vibration system, the vibration system comprises a voice coil and a diaphragm assembly of the above embodiment, the diaphragm assembly is arranged on one side of the voice coil, and the magnetic circuit system can drive the voice coil to vibrate so as to drive the diaphragm assembly to generate sound.

[0020] According to a third aspect of the present invention, an electronic device is provided, which includes the sound generating device of the above embodiment.

[0021] One of the technical effects of the present invention is that the epoxy groups in the elastomer layer have high reactivity and can react with free radicals on the surface of the thermally conductive filler to form chemical bonds to produce stronger adhesion, and the epoxy groups will produce a ring-opening reaction, thereby obtaining a higher adhesion between the epoxy groups and the thermally conductive filler through intermolecular covalent bonds, so that the elastomer layer can be combined with the thermally conductive filler through intermolecular forces to limit the deformation of the elastomer layer, thereby reducing the linear expansion coefficient so that the surface of the diaphragm body remains flat, thereby improving the heat dissipation efficiency of the diaphragm assembly while improving the loudness and mid- and low-frequency sensitivity of the sound-emitting device using the diaphragm assembly. In addition, the epoxy groups in the elastomer layer will also react with the free radicals on the surface of the ball top to form chemical bonds, so that the adhesion between the diaphragm body and the ball top is stronger, and the epoxy groups will undergo a ring-opening reaction, so that the diaphragm body and the ball top can obtain a higher adhesion through intermolecular covalent bonds, thereby improving the reliability of the diaphragm assembly, so that the diaphragm assembly is not easy to crack during high-frequency vibration. Since there is a strong adhesion between the diaphragm body and the ball top, there is no need for an additional adhesive between the diaphragm body and the ball top, and the diaphragm body and the ball top can be integrally formed, thereby reducing the thickness and mass of the diaphragm assembly, which is beneficial to increasing the vibration space of the diaphragm assembly and improving the sound sensitivity of the sound-emitting device.

[0022] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0024] Figure 1 It is a partial cross-sectional view of a sound-generating device according to an embodiment of the present invention.

[0025] Figure 2 It is a schematic structural diagram of a diaphragm body according to an embodiment of the present invention.

[0026] Figure 3 It is a total harmonic distortion curve diagram of a sound-generating device according to an embodiment of the present invention.

[0027] Reference numerals:

[0028] 100. Sound-generating device; 110. Shell; 120. Diaphragm assembly; 121. Diaphragm body; 122. Dome; 130. Voice coil; 140. 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 the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[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 as 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 similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0034] The present invention provides a diaphragm assembly, which can be used in a sound-generating device. Figures 1 to 3 As shown, the diaphragm assembly 120 includes a diaphragm body 121 and a dome 122, and the diaphragm body 121 and the dome 122 are integrally formed. The diaphragm body 121 includes at least one elastomer layer, and the elastomer layer includes a modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer and a thermally conductive filler, wherein the modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer contains an epoxy group, and the thermally conductive filler accounts for 0.5wt% to 15wt% of the total amount of the elastomer layer, and the thermal conductivity of the elastomer layer is 0.5W / m*K to 30W / m*K, and the linear expansion coefficient of the elastomer layer is 0.5×10 -5 / ℃~80×10 -5 / ℃.

[0035] In this embodiment, the diaphragm body 121 and the ball top 122 are integrally formed. For example, the diaphragm body 121 is bonded to the ball top 122 during the injection molding process, and after cooling and solidification, the diaphragm body 121 and the ball top 122 are connected together; or, the diaphragm body 121 is heated by hot pressing and then pressed together with the ball top 122, and after solidification, the diaphragm body 121 and the ball top 122 are connected together. The above-mentioned one-piece molding method does not require the use of an adhesive, thus saving the step of bonding the diaphragm body 121 and the ball top 122. Since no adhesive is used, there is no need to set an adhesive layer between the ball top 122 and the diaphragm body 121, so the thickness of the diaphragm assembly 120 can be smaller and lighter.

[0036] The diaphragm body 121 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and a thermally conductive filler is also arranged in the elastomer layer to improve the thermal conductivity of the elastomer layer. The modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer contains epoxy groups, which have high reactivity and can react with free radicals on the surface of the thermally conductive filler to form chemical bonds to produce strong adhesion, and the epoxy groups will produce a ring-opening reaction, thereby obtaining a higher adhesion between the epoxy groups and the thermally conductive filler through intermolecular covalent bonds, so that the elastomer layer can be combined with the thermally conductive filler through intermolecular forces to limit the deformation of the elastomer layer, thereby reducing the linear expansion coefficient, so that the surface of the diaphragm body 121 remains flat and avoids speaker distortion.

[0037] The linear expansion coefficient is the ratio of the change in length of a solid material when its temperature changes by 1°C to its length at the original temperature. The unit is 1 / °C. The symbol is αt. The definition of the linear expansion coefficient is αt = (Lt-L0) / L0, where Lt is the length of the solid material after the temperature change and L0 is the length of the solid material at the original temperature. The linear expansion coefficient can be measured by TMA (thermomechanical analysis) method.

[0038] In this embodiment, the linear expansion coefficient of the elastomer layer is 0.5×10 -5 / ℃~80×10 -5 / ℃. The linear expansion coefficient of the elastomer layer can be reduced by adding thermally conductive fillers. If the linear expansion coefficient is too low, more thermally conductive fillers need to be added, and the density of the elastomer layer will increase, which will make the mass of the diaphragm body 121 too high, resulting in a decrease in the mid-frequency sensitivity of the diaphragm body 121. If the linear expansion coefficient is too high, the elastomer layer will deform greatly during the heat transfer of the diaphragm body 121, and the thermally conductive fillers will separate from the molecular chain segments, which will cause the flatness of the diaphragm body 121 to decrease, thereby causing the sound device 100 using the diaphragm assembly 120 to be distorted, with changes in loudness and reduced mid- and low-frequency sensitivity. Therefore, the linear expansion coefficient of the elastomer layer is 0.5×10 -5 / ℃~80×10 -5 / ℃, which can not only avoid the density of the elastomer layer being too high, but also keep the surface of the diaphragm body 121 flat during the heat transfer process, so as to ensure the loudness and low- and medium-frequency sensitivity of the sound-generating device 100 using the diaphragm assembly 120.

[0039] For example, the linear expansion coefficient of the elastomer layer may be 0.5×10 -5 / ℃、5×10 -5 / ℃、10×10 -5 / ℃、20×10 -5 / ℃、40×10 -5 / ℃、50×10 -5 / ℃、60×10 -5 / ℃ or 80×10 -5 The above values ​​can avoid the elastic layer from being too dense and keep the surface of the diaphragm body 121 flat during the heat transfer process, so as to ensure the loudness and low-mid frequency sensitivity of the sound device 100 using the diaphragm assembly 120 .

[0040] The linear expansion coefficient of the elastomer layer can be 0.5×10 -5 / ℃~10×10 -5 / ℃, which is beneficial to further avoid the density of the elastomer layer being too high, and can also keep the surface of the diaphragm body 121 flat during the heat transfer process of the diaphragm body 121, so as to ensure the loudness and mid- and low-frequency sensitivity of the sound-generating device 100 using the diaphragm assembly 120.

[0041] In this embodiment, thermal conductivity refers to the amount of heat transferred through an area of ​​1 square meter within 1 second under stable heat transfer conditions, when the temperature difference between the two surfaces of a 1 meter thick material is 1 degree (K, ° C). The unit of thermal conductivity is watt / meter degree (W / (m·K). Under certain conditions, the greater the thermal conductivity, the better the surface heat transfer performance. If the thermal conductivity of the elastomer layer is too large, more thermal conductive fillers need to be added, and the density of the elastomer layer will increase, which will make the mass of the diaphragm body 121 too high, thereby reducing the intermediate frequency sensitivity of the diaphragm body 121. If the thermal conductivity of the elastomer layer is too small, the thermal conductivity of the elastomer layer will not meet the use requirements. The thermal conductivity of the elastomer layer of the present invention is 0.5W / m*K~30W / m*K, which can not only avoid the density of the elastomer layer being too large, but also enable the diaphragm body 121 to have good thermal conductivity.

[0042] For example, the thermal conductivity of the elastomer layer may be 0.5 W / m*K, 1 W / m*K, 5 W / m*K, 10 W / m*K, 15 W / m*K, 20 W / m*K or 30 W / m*K, etc. The above values ​​can avoid excessive density of the elastomer layer and enable the diaphragm body 121 to have good thermal conductivity.

[0043] In this embodiment, the thermally conductive filler accounts for 0.5wt% to 15wt% of the total amount of the elastomer layer. By adding the thermally conductive filler, the thermal conductivity of the elastomer layer can be increased and the linear expansion coefficient of the elastomer layer can be reduced. If the content of the thermally conductive filler is too low, the thermal conductivity of the elastomer layer cannot be effectively increased and the linear expansion coefficient of the elastomer layer cannot be reduced. If the content of the thermally conductive filler is too high, the density of the elastomer layer will increase, which will make the mass of the diaphragm body 121 too high, thereby causing the intermediate frequency sensitivity of the diaphragm body 121 to decrease. Therefore, in the present invention, the thermally conductive filler accounts for 0.5wt% to 15wt% of the total amount of the elastomer layer, which can effectively increase the thermal conductivity of the elastomer layer and reduce the linear expansion coefficient of the elastomer layer, and can also avoid the density of the elastomer layer being too high.

[0044] For example, the thermal conductive filler may account for 0.5wt%, 1wt%, 5wt%, 7wt%, 10wt% or 15wt% of the total amount of the elastomer layer, etc. The above values ​​can effectively increase the thermal conductivity of the elastomer layer and reduce the linear expansion coefficient of the elastomer layer, and can also avoid the elastomer layer from being too dense.

[0045] The thermally conductive filler accounts for 1wt% to 5wt% of the total weight of the elastomer layer, which is beneficial to further effectively increase the thermal conductivity of the elastomer layer and reduce the linear expansion coefficient of the elastomer layer, and can also avoid the elastomer layer from being too dense.

[0046] In this embodiment, the material of the ball top 122 can be carbon fiber, aluminum, aluminum alloy or engineering plastic (Peek (polyetheretherketone) and PI (polyimide)), etc. The shape of the ball top 122 is circular, rectangular, oval, etc.

[0047] In an embodiment of the present invention, the epoxy groups in the elastomer layer have high reactivity and can react with free radicals on the surface of the thermally conductive filler to form chemical bonds to produce stronger adhesion, and the epoxy groups will produce a ring-opening reaction, thereby obtaining a higher adhesion between the epoxy groups and the thermally conductive filler through intermolecular covalent bonds, so that the elastomer layer can be combined with the thermally conductive filler through intermolecular forces to limit the deformation of the elastomer layer, thereby reducing the linear expansion coefficient, so that the surface of the diaphragm body 121 remains flat, which is beneficial to avoid distortion of the sound-emitting device 100 using the diaphragm assembly 120. In addition, the epoxy groups in the elastomer layer will also react with the free radicals on the surface of the ball top 122 to form chemical bonds, so that the adhesion between the diaphragm body 121 and the ball top 122 is stronger, and the epoxy groups will undergo a ring-opening reaction, so that the diaphragm body 121 and the ball top 122 can obtain a higher adhesion through intermolecular covalent bonds, thereby improving the reliability of the diaphragm assembly 120, so that the diaphragm assembly 120 is not easy to crack during high-frequency vibration. Since there is a strong adhesion between the diaphragm body 121 and the ball top 122, there is no need for an additional adhesive between the diaphragm body 121 and the ball top 122, and the diaphragm body 121 and the ball top 122 can be integrally formed, thereby reducing the thickness and mass of the diaphragm assembly 120, which is beneficial to increasing the vibration space of the diaphragm assembly 120 and improving the sound sensitivity of the sound-generating device 100.

[0048] In a specific embodiment of the present invention, the thermally conductive filler includes at least one of a metal filler or a high thermal conductivity inorganic non-metal filler, the metal filler is at least one of aluminum, copper, silver, magnesium, tin, lead, and iron, and the non-metal filler is at least one of boron nitride, boron carbide, silicon carbide, alumina, graphite, carbon nanotubes, graphene, and nano-carbon powder.

[0049] In this embodiment, the thermal conductive filler can be one of a metal filler and a high thermal conductive inorganic non-metal filler, or the thermal conductive filler can also be a mixed material of a metal filler and a high thermal conductive inorganic non-metal filler. Among them, the metal filler includes aluminum, copper, silver, magnesium, tin, lead, and iron. Non-metallic fillers include boron nitride, boron carbide, silicon carbide, aluminum oxide, graphite, carbon nanotubes, graphene, and nano-carbon powder. Regarding the specific materials of the thermal conductive filler, those skilled in the art can mix and match according to actual conditions, and no specific restrictions are made here.

[0050] In a specific embodiment of the present invention, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer further contains benzene rings, and the molar ratio of the epoxy groups to the benzene rings is 0.05% to 5%.

[0051] In this embodiment, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (modified SEBS) contains epoxy groups and benzene rings, and its molecular formula is:

[0052] Among them, the molar ratio of epoxy group to benzene ring is in the range of 0.05%-5%. The benzene ring is generally located at the end of the modified SEBS, and the content of the end-capped benzene ring is fixed. Therefore, when the molar ratio of epoxy group to benzene ring is too low, that is, the content of epoxy group is too low, the content of intermolecular covalent bonds that the epoxy group can produce ring-opening reaction is low, resulting in too small adhesion between the diaphragm body 121 and the ball top 122, which cannot meet the structural strength requirements; and when the molar ratio of epoxy group to benzene ring is too high, the content of epoxy group is too high, and the temperature required for the integral molding of the diaphragm body 121 and the ball top 122 is high, resulting in reduced processing efficiency. Therefore, the molar ratio of epoxy group to benzene ring is in the range of 0.05% to 5%, so that the diaphragm body 121 and the ball top 122 can have a higher adhesion, and the temperature of the integral molding of the diaphragm body 121 and the ball top 122 can be avoided to be too high, which affects the processing efficiency.

[0053] For example, the molar ratio of epoxy groups to benzene rings can be 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4% or 5%, etc. The above values ​​can make the bonding force between the diaphragm body 121 and the ball top 122 higher and facilitate the integral molding of the diaphragm body 121 and the ball top 122.

[0054] In this embodiment, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is formed by grafting reaction between the polystyrene-poly(ethylene-butylene)-polystyrene block copolymer and the active compound containing epoxy group, wherein the active compound includes at least one of glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane and 2,3-epoxypropyltrimethylammonium chloride.

[0055] For example, polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (SEBS) is grafted with glycidyl methacrylate containing an epoxy group to form a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (modified SEBS).

[0056]

[0057] Among them, the grafting reaction is also called graft copolymerization or graft (co)polymerization. SEBS grafting is a free radical reaction, and the epoxy group is grafted onto the SEBS molecular chain in the form of monomers and oligomers, and the grafting position is on the unhydrogenated double bond.

[0058] In a specific embodiment of the present invention, the elongation at break of the elastomer layer is greater than or equal to 100% to 800%.

[0059] In this embodiment, the modified SEBS is a thermoplastic elastomer, and its molecular structure is composed of a polystyrene hard segment and a polyolefin soft segment. This block copolymer structure enables the elastomer layer composed of the modified SEBS to have good elasticity, flexibility and high elongation at break. That is, the elongation at break of the elastomer layer can be 100%-800%. When the elongation at break of the elastomer layer is too low, the diaphragm body 121 is easily damaged during molding. When the elongation at break of the elastomer layer is too high, it helps to improve the sensitivity and response speed of the diaphragm body 121, which is beneficial to improving the performance of the sound-generating device 100. However, excessive elongation at break may also cause the diaphragm body 121 to be easily fatigued after long-term use, thereby affecting the durability and stability of the diaphragm assembly 120. The elongation at break of the elastomer layer is 100%-800%, which makes the diaphragm body 121 not easy to be damaged, and the diaphragm assembly 120 has high durability and stability.

[0060] For example, the elongation at break of the elastomer layer can be 100%, 150%, 200%, 300%, 400%, 500%, 600%, 700% or 800%, etc. The above values ​​can make the diaphragm body 121 not easily damaged and the diaphragm assembly 120 has high durability and stability.

[0061] Among them, when the elongation at break of the elastic layer is 150%-500%, it is beneficial to further improve the durability and stability of the diaphragm assembly 120.

[0062] In a specific embodiment of the present invention, the Young's modulus of the elastomer layer is 15 MPa to 700 MPa.

[0063] In this embodiment, the Young's modulus of the elastomer layer is 15MPa-700MPa. When the Young's modulus of the elastomer layer is too low, the diaphragm body 121 is easily damaged during molding, and the F0 (the lowest vibration frequency of the diaphragm body 121 that the product can make sound) required by the product cannot be achieved. It can only be achieved by thickening, but the increase in thickness will lead to an increase in the mass of the diaphragm assembly 120, which will lose its vibration space and reduce the sensitivity of the mass control area. When the Young's modulus is too high, the flexibility and resilience of the material deteriorate. In order to obtain high loudness, the product requires the diaphragm body 121 to have a large displacement. At this time, the excessively high Young's modulus will inevitably bring adverse effects. The Young's modulus of the elastomer layer is 15MPa-700MPa, which makes the diaphragm body 121 not easy to be damaged, and has good flexibility and resilience.

[0064] For example, the Young's modulus of the elastomer layer can be 15MPa, 30MPa, 50MPa, 100MPa, 150MPa, 200MPa, 300MPa, 400MPa, 500MPa or 700MPa, etc. The above values ​​make the diaphragm body 121 not easily damaged and have good flexibility and resilience.

[0065] The Young's modulus of the elastomer layer may be 30 MPa-150 MPa, which is also beneficial to further make the diaphragm body 121 less prone to damage and have good flexibility and resilience.

[0066] In a specific embodiment of the present invention, the thickness of the elastomer layer is 10 μm to 300 μm; and / or the density of the elastomer layer is 0.8 g / cm 3 -1.2g / cm 3 .

[0067] In this example, the thickness of the elastomer layer is 10μm-300μm. When the thickness of the elastomer layer is too thin, the rigidity of the diaphragm body 121 will be insufficient and the film making will be difficult. When the thickness of the elastomer layer is too thick, the mass of the diaphragm body 121 will increase, which will easily lead to a decrease in the sensitivity of the diaphragm body 121. Moreover, if the thickness of the elastomer layer is too large, it will occupy the vibration space of the diaphragm assembly 120, thereby affecting the sound effect of the sound-generating device 100. The thickness of the elastomer layer is 10μm-300μm, which can make the diaphragm body 121 have good rigidity, reduce the difficulty of film making, and help to reduce the mass of the diaphragm body 121 and improve the sensitivity of the diaphragm body 121.

[0068] For example, the thickness of the elastic layer can also be 10 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm or 300 μm, etc. The above values ​​can make the diaphragm body 121 have good rigidity, reduce the difficulty of film making, and help reduce the mass of the diaphragm body 121 and improve the sensitivity of the diaphragm body 121.

[0069] The thickness of the elastomer layer may be 20um-150um, which is beneficial to further make the diaphragm body 121 have good rigidity, reduce the difficulty of film making, reduce the mass of the diaphragm body 121, and improve the sensitivity of the diaphragm body 121.

[0070] In this embodiment, the density of the elastomer layer is 0.8 g / cm 3 -1.2g / cm 3 When the density of the elastomer is too low, the mechanical strength of the diaphragm body 121 will be reduced. During use, the diaphragm body 121 is easily damaged and difficult to meet the use requirements. If the density of the elastomer layer is too high, it will affect the acoustic performance of the diaphragm assembly 120. The density of the elastomer layer is 0.75g / cm 3 -1.1g / cm 3 , which can ensure the mechanical strength of the diaphragm body 121 and avoid affecting the acoustic performance of the diaphragm assembly 120.

[0071] For example, the density of the elastomer layer may be 0.75 g / cm 3 , 0.8g / cm 3 , 0.9g / cm 3 , 1.0g / cm 3 or 1.1 g / cm 3 The above values ​​can ensure the mechanical strength of the diaphragm body 121 and avoid affecting the acoustic performance of the diaphragm assembly 120.

[0072] The density of the elastomer layer can be 0.8 g / cm 3 -0.9g / cm 3 , which is beneficial to further ensure the mechanical strength of the high diaphragm body 121 while avoiding affecting the acoustic performance of the diaphragm assembly 120.

[0073] In this embodiment, the elastomer layer can simultaneously meet the requirements of a thickness of 10 μm to 300 μm and a density of 0.8 g / cm 3 -1.2g / cm 3 Alternatively, the elastomer layer may have a thickness of 10 μm to 300 μm and a density of 0.8 g / cm 3 -1.2g / cm 3 One of the conditions in .

[0074] In a specific embodiment of the present invention, the melting temperature of the elastomer layer is 130°C to 220°C.

[0075] In this embodiment, the melting temperature of the elastomer layer is 130°C to 220°C. If the melting temperature of the elastomer layer is too low, the folded ring molding is difficult. If the melting temperature of the elastomer layer is too high, it needs to be heated to a higher temperature to be molded, which will affect the processing efficiency of the diaphragm body 121. Therefore, the melting temperature of the elastomer layer of the present application is 130°C to 220°C, which facilitates the molding of the diaphragm body 121 and also improves the processing efficiency of the diaphragm body 121.

[0076] For example, the melting temperature of the elastic layer may be 130° C., 150° C., 180° C., 200° C. or 220° C., etc. The above values ​​can facilitate the molding of the diaphragm body 121 and also improve the processing efficiency of the diaphragm body 121 .

[0077] The melting temperature of the elastic layer may be 150° C.-180° C., which is beneficial to further reduce the difficulty of molding the diaphragm body 121 , and at the same time can also improve the processing efficiency of the diaphragm body 121 .

[0078] In a specific embodiment of the present invention, the ejection force of the diaphragm assembly 120 after being baked in an environment of 130° C. for 6 hours is 10N-30N.

[0079] In this embodiment, the ejection force indicates the magnitude of the adhesive force between the diaphragm body 121 and the ball top 122. The ejection force of the diaphragm assembly 120 after baking in a 130°C environment for 6 hours is 10N-30N, that is, after the diaphragm assembly 120 is baked in a 130°C environment for 6 hours, there is still a large adhesive force between the diaphragm body 121 and the ball top 122. The diaphragm assembly 120 of the present invention has good thermal conductivity, and thus can have good heat resistance, and the diaphragm assembly 120 still has excellent structural stability under high temperature conditions.

[0080] Among them, the test methods of ejection force include:

[0081] a) fixing the diaphragm assembly 120 by using a tool;

[0082] b) Install a top head below the tensile gauge, and place the diaphragm assembly 120 and the top head of the tensile gauge vertically;

[0083] c) Run the dynamometer so that the ejector head vertically contacts the ball top 122 and runs to the position where the diaphragm body 121 and the ball top 122 are separated or the diaphragm body 121 is damaged, and record the force value of the dynamometer at this time, which is the ejection force.

[0084] In this embodiment, after baking in an environment of 130°C for 6 hours, if the ejection force is too low, the bonding force between the diaphragm body 121 and the ball top 122 is small, and the heat resistance of the diaphragm assembly 120 is poor. If the ejection force is too high, the diaphragm body 121 needs to contain more epoxy groups. The more epoxy groups there are, the higher the molding temperature of the diaphragm body 121 is, which reduces the processing efficiency of the diaphragm body 121. The ejection force of the diaphragm assembly 120 of the present invention is 10N-30N, so that the reliability of the diaphragm assembly 120 is high and the processing efficiency of the diaphragm body 121 is high. For example, the ejection force of the diaphragm assembly 120 can be 10N, 15N, 20N, 25N or 30N, etc. The above values ​​can all make the reliability of the diaphragm assembly 120 high and the processing efficiency of the diaphragm body 121 high.

[0085] In a specific embodiment of the present invention, the diaphragm body 121 is formed as a single-layer structure, and the diaphragm body 121 is composed of a layer of the elastomer layer; or, the diaphragm body 121 is formed as a composite layer structure, and the diaphragm body 121 includes the elastomer layer and a composite layer, and the composite layer includes engineering plastics and / or elastomeric materials.

[0086] In this embodiment, the diaphragm body 121 may be a single-layer structure, that is, the diaphragm body 121 is composed of a single elastomer layer, and the single-layer elastomer layer is integrally formed with the dome 122. The single-layer diaphragm body 121121 is thinner and lighter, which is conducive to the thin design of the diaphragm assembly 120.

[0087] Alternatively, the diaphragm body 121 may also be a composite layer structure, that is, the diaphragm body 121 is composed of an elastomer layer and a composite layer. Among them, the composite layer may be one or both of engineering plastics and elastomer materials. By adding a composite layer, the diaphragm body 121 can combine the advantages of the elastomer layer and the composite layer, and can further improve the heat resistance, compression deformation resistance, aging resistance, etc. of the diaphragm body 121, and improve the mechanical properties of the diaphragm body 121. Engineering plastics include PEEK (polyetheretherketone) and PI (polyimide), etc., and elastomeric materials include TPU (thermoplastic polyurethane elastomer), TPEE (thermoplastic polyester elastomer) and rubber, etc. Of course, the specific material of the composite layer can be determined by those skilled in the art according to the actual situation, and no specific limitation is made here.

[0088] When the diaphragm body 121 is a composite layer structure, the diaphragm body 121 can be integrally formed with the sphere by hot pressing. The diaphragm body 121 includes an elastomer layer and a composite layer, and the elastomer layer is hot pressed and bonded to the spherical top 122 .

[0089] In a specific embodiment of the present invention, the diaphragm body 121 and the dome 122 are integrally formed by hot pressing or integrally formed by injection molding.

[0090] In this embodiment, the diaphragm body 121 can be integrally hot-pressed or integrally injection-molded with the dome 122. The molding temperature of the diaphragm body 121 and the dome 122 is 80°C-200°C. When the diaphragm body 121 and the dome 122 are molded, at the molding temperature, the epoxy group in the elastomer layer will produce a ring-opening reaction, thereby obtaining a higher adhesion through intermolecular covalent bonds. When the molding temperature is too low, the molding state of the diaphragm assembly 120 is poor, and when the molding temperature is too high, the diaphragm body 121 decomposes, which also affects the flatness of the diaphragm body 121.

[0091] For example, the molding temperature can be 80°C, 100°C, 120°C, 150°C, 180°C, or 200°C, etc. The above value ranges can all enable the diaphragm body 121 and the ball top 122 to produce a strong bonding force during molding, and the diaphragm assembly 120 is in a good molding state and the surface of the diaphragm body 121 is smooth.

[0092] Among them, the molding temperature of the diaphragm body 121 and the ball top 122 can be 100℃-150℃, which is conducive to further generating a stronger bonding force between the diaphragm body 121 and the ball top 122 during molding, and the molding state of the diaphragm assembly 120 is good, and the surface of the diaphragm body 121 is flat.

[0093] According to a second aspect of the present invention, a sound-generating device 100 is provided, the sound-generating device 100 comprising a vibration system and a magnetic circuit system matched with the vibration system, the vibration system comprising a voice coil 130 and a diaphragm assembly 120 as in the above embodiment, the diaphragm assembly 120 being arranged on one side of the voice coil 130, the magnetic circuit system being able to drive the voice coil 130 to vibrate so as to drive the diaphragm assembly 120 to generate sound. The sound-generating device 100 may be a speaker unit or a speaker module, etc.

[0094] like Figure 1 As shown, the sound-generating device 100 may include a housing 110, a magnetic circuit system and a vibration system, wherein the magnetic circuit system includes a permanent magnet 140, and the permanent magnet 140 is used to form a magnetic gap. The vibration system includes a diaphragm assembly 120 and a voice coil 130. The diaphragm assembly 120 and the permanent magnet 140 are both connected to the housing 110. The permanent magnet 140 is arranged on one side of the diaphragm assembly 120 along the vibration direction of the voice coil 130. One end of the voice coil 130 is connected to the diaphragm assembly 120, and the other end is located in the magnetic gap.

[0095] In this embodiment, the diaphragm assembly 120 includes a diaphragm body 121 and a dome 122, and the diaphragm body 121 and the dome 122 are integrally formed. The diaphragm body 121 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer contains epoxy groups. The epoxy groups in the elastomer layer have high reactivity and can react with free radicals on the surface of the thermally conductive filler to form chemical bonds to produce strong adhesion. The epoxy groups will produce a ring-opening reaction, thereby obtaining a higher adhesion between the epoxy groups and the thermally conductive filler through intermolecular covalent bonds, so that the elastomer layer can be combined with the thermally conductive filler through intermolecular forces to limit the deformation of the elastomer layer, thereby reducing the linear expansion coefficient, so that the surface of the diaphragm body 121 remains flat, thereby avoiding distortion of the diaphragm assembly 120.

[0096] In addition, the epoxy groups in the elastomer layer will also react with the free radicals on the surface of the ball top 122 to form chemical bonds, so that the adhesion between the diaphragm body 121 and the ball top 122 is stronger, and the epoxy groups undergo a ring-opening reaction, so that the diaphragm body 121 and the ball top 122 obtain a higher adhesion through intermolecular covalent bonds, thereby improving the reliability of the diaphragm assembly 120, so that the diaphragm assembly 120 is not easy to crack during high-frequency vibration. Since there is a strong adhesion between the diaphragm body 121 and the ball top 122, there is no need for an additional adhesive between the diaphragm body 121 and the ball top 122, and the diaphragm body 121 and the ball top 122 can be integrally formed, thereby reducing the thickness and mass of the diaphragm assembly 120, which is beneficial to increasing the vibration space of the diaphragm assembly 120 and improving the sound sensitivity of the sound-generating device 100.

[0097] Of course, the sound-generating device 100 of the present invention also includes at least all the beneficial effects of the above-mentioned embodiments, which will not be elaborated here.

[0098] According to a third aspect of the present invention, an electronic device is provided. The electronic device includes the sound-generating device 100 of the above embodiment. The electronic device may be a mobile phone, a smart watch or a computer. 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.

[0099] The diaphragm assembly 120 of the present invention is described in detail below with specific embodiments and comparative examples. It is worth understanding that the following description is only exemplary and not a specific limitation of the present invention. The following comparative examples are selected to demonstrate the technical progress of the technical solution of the present invention, and the comparative examples are not all conventional technologies in the technical field.

[0100] Embodiment 1: The diaphragm body 121 is composed of an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The molar ratio of epoxy groups to benzene rings in the elastomer layer is 5:1000, and the mass fraction of the thermal conductive filler is 1.5wt%. The dome 122 is an aluminum composite material. The diaphragm body 121 and the dome 122 are integrally hot-pressed, the hot-pressing temperature is 160°C, and the hot-pressing time is 20s.

[0101] In Example 2, the diaphragm body 121 is composed of an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The molar ratio of epoxy groups to benzene rings in the elastomer layer is 5:1000, and the mass fraction of the thermal conductive filler is 3wt%. The dome 122 is an aluminum composite material. The diaphragm body 121 and the dome 122 are integrally hot-pressed, the hot-pressing temperature is 160°C, and the hot-pressing time is 20s.

[0102] In comparative example 1, the diaphragm body is composed of an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The molar ratio of epoxy groups to benzene rings in the elastomer layer is 5:1000. The dome is an aluminum composite material. The diaphragm body and the dome are integrally hot-pressed at a temperature of 160°C and a hot-pressing time of 20 seconds.

[0103] In comparative example 2, the diaphragm body is composed of a layer of silicone rubber film. The dome is an aluminum composite material. The bonding layer between the diaphragm body and the dome is an acrylic film. The bonding layer is annular and has a thickness of 25 μm. One side of the bonding layer is first bonded to the dome, and then the other side of the bonding layer is pressed onto the diaphragm body at room temperature for 20 seconds.

[0104] Table 1 Performance data of the diaphragm assembly of Examples 1, 2 and Comparative Examples 1, 2

[0105] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Vibration component thickness / μm 120 120 120 145 Diaphragm body thickness / μm 40 40 40 40 Adhesive layer thickness / μm 0 0 0 25 <![CDATA[Coefficient of linear expansion 10 -5 / °C]]> 5.2 3.6 6.2 45 Thermal conductivity W / m*K 1.2 2.4 0.28 0.27

[0106] As shown in Table 1, the thickness of the diaphragm body and the dome of the diaphragm assembly in Examples 1 and 2 and Comparative Examples 1 and 2 are the same, the thickness of the diaphragm body is 40 μm, and the thickness of the dome is 80 μm. The overall thickness of the two diaphragm assemblies in Examples 1 and 2 is 120 μm. The overall thickness of the diaphragm assembly in Comparative Example 1 is 120 μm, the thickness of the adhesive layer in Comparative Example 2 is 25 μm, and the overall thickness is 145 μm. Since the diaphragm assemblies in Examples 1 and 2 are integrally formed, there is no adhesive layer, which makes the thickness of the diaphragm assembly 120 in Examples 1 and 2 significantly smaller than the thickness of the diaphragm assembly 120 in Comparative Example 2.

[0107] The linear expansion coefficient of the diaphragm body of Example 1 is 5.2×10 -5 / ℃, the thermal conductivity is 1.2W / m*K, and the linear expansion coefficient of the diaphragm body of Example 2 is 3.6×10 -5 / ℃, thermal conductivity is 0.28W / m*K. The linear expansion coefficient of comparative example 1 is 6.2×10 -5 / ℃, the thermal conductivity is 0.28W / m*K, and the linear expansion coefficient of comparative example 2 is 45×10 -5 / ℃, and the thermal conductivity is 0.27W / m*K. It can be seen that the diaphragm body in Examples 1 and 2 is composed of an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and a thermally conductive filler is arranged in the elastomer layer, so that the linear expansion coefficient of the diaphragm body can be effectively reduced, and the thermal conductivity of the diaphragm body can be increased, so that the surface of the diaphragm body can be kept flat when the diaphragm assembly transfers heat, thereby avoiding speaker distortion and improving the loudness and mid- and low-frequency sensitivity of the sound-generating device using the diaphragm assembly.

[0108] In addition, the elastomer layer of Comparative Example 2 is also composed of modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and its linear expansion coefficient is slightly greater than that of the elastomer layer of Examples 1 and 2. It can be seen that the diaphragm body of the present invention is composed of an elastomer layer composed of modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and the elastomer layer contains epoxy groups, so that the elastomer layer can improve the adhesion through intermolecular covalent bonds, limit the deformation of the elastomer layer, and thus reduce the linear expansion coefficient. The thermal conductivity of the diaphragm body of Examples 1 and 2 is less than that of the elastomer layer in Comparative Example 1. It can be seen that the diaphragm body of Examples 1 and 2 can effectively increase the thermal conductivity of the diaphragm body by adding thermally conductive fillers.

[0109] The diaphragm assemblies in Example 2 and Comparative Example 2 were assembled into the same type of sound-generating device, and the acoustic performance reliability test was performed after the device was operated continuously for 48 hours at 3V in an environment of 65°C and 95% humidity. Figure 3 As shown, they are the total harmonic distortion curves of Example 2 and Comparative Example 2, respectively. The horizontal axis represents the vibration frequency, in Hz; the vertical axis represents the harmonic distortion, in %.

[0110] like Figure 3 As shown, between about 500 Hz and 900 Hz, the harmonic distortion curve of the sound-generating device 100 in Example 2 is smoother and has more peaks than the harmonic distortion curve of the sound-generating device in Comparative Example 2. It can be seen that the low-frequency distortion of the sound-generating device in Comparative Example 2 is more serious. Therefore, since the diaphragm assembly 120 in Example 2 has no adhesive layer, the diaphragm assembly 120 is light in weight and small in thickness, and the diaphragm body 121 is provided with a heat-conductive filler, has good heat dissipation performance, can be used for a long time in a high-temperature environment, and can also maintain stable sound quality.

[0111] In summary, the diaphragm assembly 120 of Example 1 and Example 2 includes a diaphragm body 121 and a dome 122 that are integrally formed. Compared with the diaphragm bodies of Comparative Examples 1 and 2, the diaphragm body 121 of the diaphragm assembly 120 of the two embodiments of Example 1 and Example 2 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and the elastomer layer contains epoxy groups and thermally conductive fillers. It can react with the free radicals on the surface of the thermally conductive filler to form a chemical bond to produce a strong adhesive force, and the epoxy group will produce a ring-opening reaction, thereby obtaining a higher adhesive force between the epoxy group and the thermally conductive filler through an intermolecular covalent bond, so that the elastomer layer can be combined with the thermally conductive filler through an intermolecular force to limit the deformation of the elastomer layer, thereby being able to reduce the linear expansion coefficient, so that the surface of the diaphragm body 121 remains flat, thereby improving the heat dissipation performance of the diaphragm assembly 120 while avoiding speaker distortion, and improving the loudness and mid- and low-frequency sensitivity of the sound-generating device 100 using the diaphragm assembly 120.

[0112] 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.

[0113] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A diaphragm assembly, characterized in that: include: A diaphragm body and a dome, wherein the diaphragm body and the dome are integrally formed; The diaphragm body includes at least one elastomer layer, the elastomer layer includes a modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer and a thermally conductive filler, the modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer contains an epoxy group, the thermally conductive filler accounts for 0.5wt% to 15wt% of the total amount of the elastomer layer, the thermal conductivity of the elastomer layer is 0.5W / m*K to 30W / m*K, and the linear expansion coefficient of the elastomer layer is 0.5×10 -5 / ℃~80×10 -5 / ℃.

2. The diaphragm assembly according to claim 1, characterized in that: The thermal conductive filler accounts for 1 wt % to 5 wt % of the total weight of the elastomer layer.

3. The diaphragm assembly according to claim 1, characterized in that: The thermally conductive filler includes at least one of a metal filler or a high thermal conductivity inorganic non-metal filler, the metal filler is at least one of aluminum, copper, silver, magnesium, tin, lead, and iron, and the non-metal filler is at least one of boron nitride, boron carbide, silicon carbide, alumina, graphite, carbon nanotubes, graphene, and nano-carbon powder.

4. The diaphragm assembly according to claim 1, characterized in that: The modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer also contains benzene rings, and the molar ratio of the epoxy group to the benzene ring is 0.05% to 5%.

5. The diaphragm assembly according to claim 1, characterized in that: The elongation at break of the elastic layer is greater than or equal to 100% to 800%.

6. The diaphragm assembly according to claim 1, characterized in that: The Young's modulus of the elastomer layer is 15 MPa to 700 MPa.

7. The diaphragm assembly according to claim 1, characterized in that: The thickness of the elastomer layer is 10 μm to 300 μm; And / or, the density of the elastomer layer is 0.8 g / cm 3 -1.2g / cm 3 .

8. The diaphragm assembly according to claim 1, characterized in that: The melting temperature of the elastic layer is 130°C to 220°C.

9. The diaphragm assembly according to any one of claims 1 to 8, characterized in that: The ejection force of the diaphragm assembly after baking in an environment of 130° C. for 6 hours is 10N-30N.

10. The diaphragm assembly according to claim 1, characterized in that: The diaphragm body is formed into a single-layer structure, and the diaphragm body is composed of a layer of the elastic body; Alternatively, the diaphragm body is formed as a composite layer structure, the diaphragm body includes the elastomer layer and the composite layer, and the composite layer includes engineering plastics and / or elastomer materials.

11. A sound-generating device, characterized in that: The sound-generating device includes a vibration system and a magnetic circuit system coordinated with the vibration system, the vibration system includes a voice coil and a diaphragm assembly as described in any one of claims 1 to 10, the diaphragm assembly is arranged on one side of the voice coil, and the magnetic circuit system can drive the voice coil to vibrate to drive the diaphragm assembly to produce sound.

12. An electronic device, characterized in that: Comprising the sound-generating device as claimed in claim 11.

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