CN112399289A

CN112399289A - Miniature speaker module with high heat dissipation efficiency and smart phone comprising same

Info

Publication number: CN112399289A
Application number: CN202011389219.7A
Authority: CN
Inventors: 张磊; 郭明波; 马院红; 刘仁坤; 张洪鹏; 龚畅; 赵峻杰
Original assignee: Zhenjiang Best New Material Co ltd
Current assignee: Zhenjiang Best New Material Co ltd
Priority date: 2020-12-02
Filing date: 2020-12-02
Publication date: 2021-02-23

Abstract

The invention provides a micro speaker module with high heat dissipation efficiency and a smart phone comprising the same, wherein the micro speaker module comprises an upper shell, a lower shell and a loudspeaker unit; the loudspeaker unit is arranged on the upper shell or the lower shell, the upper shell and the loudspeaker unit form a front cavity, the lower shell and the loudspeaker unit form a rear cavity, at least one part of the loudspeaker unit is positioned in the rear cavity, and a heat-conducting sound-absorbing material is filled in the rear cavity; the upper shell is fixedly connected with the lower shell; and the side wall of the rear cavity is provided with a sound outlet. The rear cavity of the micro speaker module is filled with the heat-conducting sound-absorbing material, the heat-conducting sound-absorbing material can improve the acoustic performance of the micro speaker module by utilizing the high virtual rear cavity increasing coefficient of the heat-conducting sound-absorbing material, and can increase the heat dissipation capacity of the space around the loudspeaker unit by the high heat conductivity coefficient far higher than that of air, so that the integral heat dissipation capacity of the micro speaker module is improved.

Description

Miniature speaker module with high heat dissipation efficiency and smart phone comprising same

Technical Field

The invention relates to a micro loudspeaker module with high heat dissipation efficiency and a smart phone comprising the same, and belongs to the technical field of electroacoustic products.

Background

The micro speaker module is one of main electroacoustic devices in the smart phone as a sound production unit and is mainly responsible for converting received electric signals into audible sound signals. The micro-speaker is used as an electroacoustic transducer, and in the working process, a part of electric energy is converted into mechanical energy, and finally radiated sound waves are used for generating sound; most of the electrical energy is converted to heat, causing the voice coil temperature to rise. The voice coil temperature exceeds a certain range, the sound effect of the micro loudspeaker can be influenced, and even the normal use of the micro loudspeaker is influenced, so that the heat dissipation problem needs to be considered in advance when the micro loudspeaker module is designed. In recent years, the loudness of a loudspeaker in a mobile phone is gradually increased, the amplitude of a micro loudspeaker is gradually increased, and the heat generation of the mobile phone loudspeaker is further aggravated, so that a certain heat dissipation problem is caused.

In order to improve the acoustic performance, the addition of sound-absorbing materials into the micro-speaker has become a common means, but most of the sound-absorbing materials do not have the function of improving the heat dissipation capability of the product.

At present, promote the radiating efficiency of miniature speaker module, the main mode that reduces the voice coil loudspeaker voice coil temperature has:

1) optimizing the structure and the material of the horn of the micro speaker module, for example, manufacturing the horn shell of the micro speaker module by adopting high-heat-conductivity material steel and the like;

2) optimizing a micro speaker module structure, adopting a structure that a speaker Yoke of the micro speaker module leaks outwards, and adopting SUS material at the local part of a module shell to enhance the heat dissipation efficiency of the module;

3) paste high heat conduction material auxiliary material in miniature speaker module shell, for example paste the graphite piece at miniature speaker module shell to reinforcing radiating efficiency.

The existing micro speaker module improves the heat dissipation efficiency, reduces the mode of voice coil loudspeaker voice coil temperature, only utilizes the heat conductivity coefficient of improving loudspeaker body, micro speaker module shell to promote the heat dissipation efficiency, and the most efficient route of heat dissipation is only concentrated on the upper and lower position of loudspeaker body, dispels the heat through air convection and heat conduction form. The intracavity has numerous air behind the miniature speaker module, occupies the air space of most volumes behind the miniature speaker module, has very low coefficient of heat conductivity because of the air, makes the product fail the high-efficient space around utilizing loudspeaker to dispel the heat.

Therefore, it is an urgent technical problem to be solved in the art to provide a micro speaker module with high heat dissipation efficiency and a smart phone including the same.

Disclosure of Invention

In order to solve the above disadvantages and shortcomings, an object of the present invention is to provide a micro speaker module with high heat dissipation efficiency.

Another object of the present invention is to provide a smart phone including the micro speaker module with high heat dissipation efficiency.

In order to achieve the above objects, in one aspect, the present invention provides a micro speaker module with high heat dissipation efficiency, wherein the micro speaker module with high heat dissipation efficiency comprises: an upper shell, a lower shell and a loudspeaker unit; the loudspeaker unit is arranged on the upper shell or the lower shell, the upper shell and the loudspeaker unit form a front cavity, the lower shell and the loudspeaker unit form a rear cavity, at least one part of the loudspeaker unit is positioned in the rear cavity, and a heat-conducting sound-absorbing material is filled in the rear cavity; the upper shell is fixedly connected with the lower shell; and the side wall of the rear cavity is provided with a sound outlet.

In an embodiment of the above micro speaker module, the heat conducting and sound absorbing material includes a heat conducting additive.

As a specific embodiment of the above micro speaker module according to the present invention, the heat conducting additive includes one or more of graphene, aluminum oxide, zinc oxide, magnesium oxide, quartz powder, silicon carbide, aluminum nitride, and boron carbide.

In an embodiment of the above micro speaker module, the particle size of the heat conducting additive is 50-500 nm.

In one embodiment of the present invention, the thermal conductive additive may be a nano-powder thermal conductive additive.

In an embodiment of the above micro speaker module, the heat conducting additive is uniformly dispersed and filled in the heat conducting sound absorbing material or coated on the surface of the heat conducting sound absorbing material.

In an embodiment of the above micro speaker module, the heat conducting and sound absorbing material is a high heat conducting and sound absorbing material, and the heat conductivity is 0.2-20W/mK.

In an embodiment of the above micro speaker module, the heat conducting and sound absorbing material includes sound absorbing particles, sound absorbing sheets, or sound absorbing blocks.

In an embodiment of the above micro speaker module according to the present invention, the sound absorption block has a first-stage hole with a pore diameter ranging from 0.3 nm to 0.7nm, a second-stage hole with a pore diameter ranging from 20 nm to 50nm, and a third-stage hole with a pore diameter ranging from 1 μm to 100 μm. Wherein the first level pores are micropores of the molecular sieve particles, the second level pores are pores formed among the molecular sieve particles, and the third level pores comprise pores formed among the molecular sieve particles and pores formed by array needles equal to the sound absorption block (such as the surface).

In an embodiment of the above micro speaker module according to the present invention, the sound absorption block is made by bonding a plurality of molecular sieve particles or sound absorption particles containing a heat conductive additive by an adhesive.

In one embodiment of the above micro speaker module according to the present invention, the molecular sieve particles have a particle size of 0.5 to 10 μm, a pore diameter of 0.3 to 0.7nm, and a Si/Al ratio of 200 or more, preferably 400 or more.

As a specific embodiment of the above micro speaker module according to the present invention, the molecular sieve particles are one or more of MFI molecular sieve and/or FER molecular sieve.

In an embodiment of the present invention, the adhesive includes an organic adhesive and/or an inorganic adhesive; the content of the organic adhesive solid component in the sound absorption block is 5-20 percent, preferably 10-20 percent, based on the total weight of the sound absorption block as 100 percent; the content of the inorganic binder in the sound absorption block is 4-15%, preferably 5-15%, based on the total weight of the sound absorption block as 100%.

In one embodiment of the present invention, the content of the organic binder solid component in the sound-absorbing block may be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% based on the total weight of the sound-absorbing block taken as 100%.

In a specific embodiment of the present invention, the content of the inorganic binder in the sound-absorbing block is 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, based on 100% by weight of the total sound-absorbing block.

As a specific embodiment of the above micro speaker module according to the present invention, the organic adhesive includes one or a combination of more of a polystyrene acrylic emulsion, a polystyrene acetic emulsion, a styrene-butadiene rubber emulsion, a polystyrene acrylate emulsion, and a polyacrylate emulsion.

As a specific embodiment of the above micro speaker module according to the present invention, the content of the solid component in the organic binder is 40% to 60% based on 100% by weight of the total organic binder.

In one embodiment of the present invention, the content of the solid component in the organic binder may be 40%, 45%, 50%, 55%, 60% based on the total weight of the organic binder being 100%.

In an embodiment of the present invention, the inorganic binder includes one or more of kaolin, silica sol, alumina sol and carboxymethyl cellulose.

As a specific embodiment of the above micro speaker module according to the present invention, the method for manufacturing the sound absorption block includes the following steps:

mixing molecular sieve particles, an adhesive and a heat conduction additive into slurry, extruding or pressing the slurry into a sound absorption block by using a mould or soaking a porous material into the slurry, and drying the sound absorption block to prepare the sound absorption block;

preferably, the amount of the heat-conducting additive is 0.5-20% of the mass of the molecular sieve particles, and more preferably 1-5%;

or mixing the molecular sieve particles and the adhesive into slurry, extruding or pressing the slurry into a sound absorption block by using a mould, or soaking the porous material into the slurry, and drying the sound absorption block to prepare the sound absorption block; finally, spraying a solution prepared by mixing a heat-conducting additive and an adhesive aqueous solution on the surface of the sound absorption block;

preferably, the content of the heat-conducting additive is 1% -10%, more preferably 2% -7%, based on 100% of the total weight of the solution;

preferably, the spraying time is 1-10min, so that the thickness of the surface coating is controlled, and the influence on the pore channels on the surface of the sound absorption block is reduced;

also preferably, the aqueous binder solution has a solids content of 5% to 20%; more preferably, the adhesive comprises one or more of a polystyrene acrylic emulsion, a polystyrene acetic emulsion, a styrene-butadiene rubber emulsion, and carboxymethyl cellulose;

or mixing sound-absorbing particles containing heat-conducting additives and adhesives into slurry, extruding or pressing the slurry into a sound-absorbing block by using a die, or soaking a porous material into the slurry, and drying the slurry to prepare the sound-absorbing block.

In one embodiment of the present invention, the amount of the heat conductive additive may be 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5%, 15.0%, 15.5%, 16.0%, 16.5%, 17.0%, 17.5%, 18.0%, 18.5%, 19.0%, 19.5%, 20.0% of the mass of the molecular sieve particles.

In a specific embodiment of the present invention, the concentration of the heat conductive additive may be 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10% based on the total weight of the solution as 100%.

In a specific embodiment of the present invention, the spraying time may be 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min, 10 min.

In one embodiment of the invention, the aqueous binder solution may have a solids content of 5%, 10%, 15%, 20%.

As a specific embodiment of the above micro speaker module according to the present invention, in the preparation process of the sound absorption block, a dispersion aid may be added to the slurry, where the dispersion aid includes one or more of ethylene glycol, glycerol, polyethylene glycol, and the like, and the addition amount of the dispersion aid is 0.5% to 3% of the weight of the molecular sieve particles.

In one embodiment of the present invention, the dispersing aid may be added in an amount of 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0% by weight of the molecular sieve particles.

In an embodiment of the above micro speaker module according to the present invention, the porous material includes one or more of foam, asbestos, and chemical fiber block.

As a specific embodiment of the above micro speaker module according to the present invention, the porous material is soaked in the slurry, and then dried at 80-160 ℃ for 12-24h to form the sound absorption block.

In an embodiment of the above micro speaker module of the present invention, the sound-absorbing particles have a particle size range of 300-700 μm, and the sound-absorbing particles have primary pores with a pore size range of 0.3-0.7nm, secondary pores with a pore size range of 20-50nm, and tertiary pores with a pore size range of 1-10 μm. Wherein, the first level hole is the micropore of the molecular sieve particle, and the second level hole and the third level hole are the holes formed among the molecular sieve particles.

In an embodiment of the above micro speaker module, the sound-absorbing particles are made of molecular sieve particles bonded by a binder.

As a specific embodiment of the above micro speaker module according to the present invention, the molecular sieve particles are one or a combination of MFI molecular sieve and/or FER molecular sieve.

In an embodiment of the present invention, the adhesive includes an organic adhesive and/or an inorganic adhesive; the content of the organic binder solid component in the sound-absorbing particles is 5% -15% by taking the total weight of the sound-absorbing particles as 100%; the content of the inorganic binder in the sound-absorbing particles is 4-10% by taking the total weight of the sound-absorbing particles as 100%.

In one embodiment of the present invention, the content of the organic binder solid component in the sound-absorbing particles may be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% and 15% by weight, based on the total weight of the sound-absorbing particles taken as 100%.

In one embodiment of the present invention, the content of the inorganic binder in the sound-absorbing particles is 4%, 5%, 6%, 7%, 8%, 9%, 10% based on 100% by weight of the total sound-absorbing particles.

As a specific embodiment of the above micro speaker module according to the present invention, the method for preparing the sound-absorbing particles includes the following steps:

mixing molecular sieve particles, an adhesive and a heat conduction additive into slurry (slurry or suspension), granulating the slurry, and drying granules obtained after granulation to obtain sound absorption granules;

preferably, the amount of the heat-conducting additive is 0.5-20%, more preferably 0.5-10%, and even more preferably 1-5% of the mass of the molecular sieve particles;

or mixing the molecular sieve particles and the adhesive into slurry, granulating the slurry, drying granules obtained after granulation, and finally spraying a solution prepared by mixing the heat-conducting additive and the adhesive aqueous solution on the surfaces of the dried granules to prepare the sound-absorbing granules;

preferably, the spraying time is 1-10min, so as to control the thickness of the surface coating and reduce the influence on the pore channels on the surface of the sound absorption particles;

also preferably, the aqueous binder solution has a solids content of 5% to 20%; more preferably, the adhesive comprises one or more of a polystyrene acrylic emulsion, a polystyrene acetic emulsion, a styrene-butadiene rubber emulsion, and carboxymethyl cellulose.

In a specific embodiment of the above micro speaker module according to the present invention, in the preparation process of the sound-absorbing particles, a dispersing aid may be added to the slurry, where the dispersing aid includes one or more of ethylene glycol, glycerol, polyethylene glycol, and the like, and the amount of the dispersing aid added is 0.5% to 3% of the weight of the molecular sieve particles. In one embodiment of the present invention, the dispersing aid may be added in an amount of 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0% by weight of the molecular sieve particles.

In one embodiment of the present invention, the amount of the heat conductive additive may be 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10%, 10.5%, 11.0%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5%, 15.0%, 15.5%, 16.0%, 16.5%, 17.0%, 17.5%, 18.0%, 18.5%, 19.0%, 19.5%, 20% of the mass of the molecular sieve particles.

As a specific embodiment of the above micro speaker module according to the present invention, in the preparation process of the sound-absorbing particles, granulation may be performed by a fluidized bed or spray granulation method; after granulation, the formed particles can be dried by adopting a heat flow tower or a low-temperature freeze-drying mode, the drying temperature, the drying time and the like are not particularly required, and a person skilled in the art can reasonably select the drying parameters according to the actual operation requirement as long as the aim of the invention can be realized.

As a specific embodiment of the above-mentioned micro speaker module of the present invention, the thickness of the sound absorption sheet is 100-1000 μm, and the sound absorption sheet has a first-stage hole with a pore size range of 0.3-0.7nm and a second-stage hole with a pore size range of 20-50 nm. Wherein the first-stage pores are micropores of the molecular sieve particles, and the second-stage pores are pores formed among the molecular sieve particles.

As a specific embodiment of the above micro speaker module according to the present invention, the sound absorption sheet is prepared by directly spraying a solution containing molecular sieve particles, a binder and a heat conduction additive onto an inner wall of a rear cavity of the micro speaker module.

In an embodiment of the present invention, the adhesive includes an organic adhesive and/or an inorganic adhesive; the content of the organic adhesive solid component in the sound absorbing sheet is 5-20%, preferably 10-20% based on 100% of the total weight of the sound absorbing sheet; the content of the inorganic adhesive in the sound absorption sheet is 4-15%, preferably 5-15%, based on the total weight of the sound absorption sheet as 100%.

In one embodiment of the present invention, the content of the organic binder solid component in the sound-absorbing sheet may be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% based on the total weight of the sound-absorbing sheet taken as 100%.

In a specific embodiment of the present invention, the content of the inorganic binder in the sound-absorbing sheet is 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, based on 100% by weight of the total sound-absorbing sheet.

In an embodiment of the above micro speaker module according to the present invention, the amount of the heat conducting additive is 0.5% to 20%, preferably 0.5% to 10%, and more preferably 1% to 5% of the mass of the molecular sieve particles.

In an embodiment of the above micro speaker module according to the invention, a certain amount of expandable microspheres is added to the heat-conducting sound-absorbing material.

In an embodiment of the micro speaker module according to the present invention, the expandable microspheres are added in an amount of 1 wt.% to 10 wt.%, and more preferably 2 wt.% to 6 wt.%, based on 100% by weight of the total heat conductive and sound absorbing material.

In an embodiment of the present invention, the expandable microspheres may be added in an amount of 1.0 wt.%, 1.5 wt.%, 2.0 wt.%, 2.5 wt.%, 3.0 wt.%, 3.5 wt.%, 4.0 wt.%, 4.5 wt.%, 5.0 wt.%, 5.5 wt.%, 6.0 wt.%, 6.5 wt.%, 7.0 wt.%, 7.5 wt.%, 8.0 wt.%, 8.5 wt.%, 9.0 wt.%, 9.5 wt.%, 10 wt.%, based on the total weight of the heat conductive and sound absorbent material taken as 100%.

As a specific embodiment of the above micro speaker module according to the present invention, the particle size range of the expandable microspheres is 200-400 μm.

As a specific embodiment of the above micro speaker module according to the present invention, the expandable microspheres are expandable microspheres having a core-shell structure, and the shell material of the expandable microspheres is an expandable polymer; the core structure of the expandable microspheres is made of a foaming agent.

As a specific embodiment of the above micro speaker module according to the present invention, the expandable polymer includes one or a combination of several of polystyrene, methyl methacrylate polymer, styrene-butyl acrylate polymer, methyl methacrylate-butyl acrylate polymer, polyurethane polymer, vinyl acetate polymer, urea-formaldehyde polymer, and melamine-formaldehyde polymer.

In an embodiment of the above micro speaker module, the blowing agent includes one or more of petroleum ether, butane, pentane and isopentane.

As a specific embodiment of the above micro speaker module according to the present invention, a heat conductive additive is further added to the shell layer, and the addition amount of the heat conductive additive is 1% to 20% based on 100% of the total weight of the shell layer.

In an embodiment of the present invention, the heat conductive additive may be added in an amount of 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10%, 12.5%, 15%, 17.5%, and 20% based on the total weight of the shell layer taken as 100%.

As a specific embodiment of the above micro speaker module according to the present invention, the preparation method of the expandable microspheres includes the following specific steps:

the expandable microspheres are produced by adding a blowing agent to the suspended expandable polymer beads, said blowing agent penetrating into the expandable polymer beads under heat and pressure to swell said beads, and remaining in said beads after cooling. The expandable microspheres prepared by the invention conduct heat through the shell layer, and the excessive heat initiates the reaction of the foaming agent to expand the expandable microspheres.

As a specific embodiment of the above micro speaker module according to the present invention, in the preparation process of the expandable microspheres, a heat conductive additive may be added to an expandable polymer bead raw material (i.e., an expandable polymer) in advance, and then the expandable polymer beads with high heat conductivity may be obtained through melt extrusion, wherein the weight content of the heat conductive additive in the expandable polymer beads with high heat conductivity is 1% to 20%.

In addition, the invention does not have specific requirements on the heating and pressurizing conditions in the preparation process of the expandable microspheres, and the temperature and pressure conditions can be reasonably set by a person skilled in the art according to the actual operation needs as long as the aim of the invention can be realized.

In an embodiment of the micro speaker module according to the invention, when the heat conducting and sound absorbing material is sound absorbing particles, the lower shell is provided with filling holes for filling the sound absorbing particles into the rear cavity.

When the heat-conducting sound-absorbing material is a sound-absorbing sheet or a sound-absorbing block, the sound-absorbing sheet or the sound-absorbing block needs to be placed in the rear cavity in advance.

As a specific embodiment of the above micro speaker module according to the present invention, a back cavity of the micro speaker module is further filled with helium gas. In general, the back cavity of the micro-speaker module contains air, and the invention adopts rare gas helium to replace the air in the back cavity, so that the back cavity is filled with helium. Because of the coefficient of heat conductivity of helium is higher than the nitrogen gas in the air, so the cavity is filled with the heat-sinking capability that helium can increase cavity inner space behind the miniature speaker module, and then improves the holistic heat-sinking capability of miniature speaker module.

As a specific embodiment of the above micro speaker module, in the invention, a sound outlet is disposed on a side wall of the speaker unit facing the rear cavity.

As a specific embodiment of the above micro speaker module according to the present invention, the surface of the sound outlet hole is provided with a mesh for isolating the heat-conducting sound-absorbing material and properly adjusting the acoustic performance of the speaker unit.

On the other hand, the invention also provides a smart phone, wherein the smart phone comprises the micro speaker module.

The rear cavity of the micro speaker module is filled with the high-heat-conductivity sound-absorbing material, the high-heat-conductivity sound-absorbing material can improve the acoustic performance of the micro speaker module by utilizing the high virtual rear cavity increasing coefficient of the high-heat-conductivity sound-absorbing material, and can increase the heat dissipation capacity of the space around the speaker unit through the high heat conductivity coefficient of the high-heat-conductivity sound-absorbing material which is far higher than air, so that the integral heat dissipation capacity of the micro speaker module is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1a is an axial view (back side) of a micro-speaker module according to an embodiment of the present invention.

Fig. 1b is an axial side view (front side) of the micro-speaker module provided in the embodiment of the present invention.

Fig. 2 is a partial component diagram of a micro-speaker module provided in an embodiment of the invention.

Fig. 3 is a cross-sectional view of a micro-speaker module provided in an embodiment of the invention.

Fig. 4 is a temperature rise curve diagram of the voice coil of the micro-speaker module provided in example 1, comparative example 1 and comparative example 2 of the present invention.

The main reference numbers illustrate:

11. an upper shell;

12. a lower case;

13. a horn unit;

14. filling holes;

15. damping;

131. screen cloth;

21. a rear cavity;

22. a front cavity;

31. high heat conduction sound absorption material.

Detailed Description

In order to clearly understand the technical features, objects and advantages of the present invention, the following detailed description of the technical solutions of the present invention will be made with reference to the following specific examples, which should not be construed as limiting the implementable scope of the present invention.

It should be noted that the term "comprises/comprising" and any variations thereof in the description and claims of this invention and the above-described drawings is intended to cover non-exclusive inclusions, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In the present invention, the terms "upper", "lower", "inside", "middle", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are used primarily to better describe the invention and its embodiments and are not intended to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation.

Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meanings of these terms in the present invention can be understood by those skilled in the art as appropriate.

Furthermore, the terms "disposed" and "connected" should be interpreted broadly. For example, "connected" may be a fixed connection, a detachable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. The specific meanings of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific situations.

Example 1

The present embodiment provides a micro speaker module, the schematic structural diagram of which is shown in fig. 1a, fig. 1b, fig. 2 and fig. 3, and as can be seen from fig. 1a, fig. 1b, fig. 2 and fig. 3, the micro speaker module includes: an upper case 11, a lower case 12, and a horn unit 13; the horn unit 13 is mounted on the upper shell 11, the upper shell 11 and the horn unit 13 form a front cavity 22, the lower shell 12 and the horn unit 13 form a rear cavity 21, at least one part of the horn unit 13 is located in the rear cavity 21, and a high thermal conductivity sound absorption material 31 is further filled in the rear cavity 21; the upper shell 11 and the lower shell 12 are assembled and fixedly connected through ultrasound or glue; the loudspeaker unit 13 has been seted up out the sound hole towards the lateral wall (minor axis lateral wall) of back chamber 21, it is provided with screen cloth 131 to go out the sound hole surface, is used for keeping apart high heat conduction acoustic material 31.

In this embodiment, the lower shell 12 is provided with a filling hole 14 for filling the rear cavity 21 with sound-absorbing particles.

In this embodiment, the lower shell 12 is further provided with a damper 15.

In the embodiment, the position of the horn unit of the lower shell of the micro loudspeaker module is hollowed, the magnetic conduction plate of the horn unit leaks outside after assembly, and glue is used for plugging a gap between the magnetic conduction plate of the horn unit and the lower shell to ensure that air does not leak;

or the position of the horn unit of the lower shell of the micro loudspeaker module is not hollowed, and the injection molding material is a material with high heat conductivity coefficient such as SUS (SUS), or the lower shell of the micro loudspeaker module adopts a steel sheet structure as much as possible.

In this embodiment, the sound absorbing material 31 with high thermal conductivity is sound absorbing particles with high thermal conductivity, the sound absorbing particles with high thermal conductivity have a particle size range of 360-450 μm, the average particle size is 390 μm, the sound absorbing particles have first-stage pores with an average pore size of 0.3-0.7nm, second-stage pores with an average pore size of 0.62nm, second-stage pores with an average pore size of 20-50nm, third-stage pores with an average pore size of 27.5nm and 1-10 μm, and the average pore size is 6.2 μm;

the high-thermal-conductivity sound-absorbing particle is prepared by bonding a plurality of molecular sieve particles through an adhesive, and the preparation method comprises the following specific steps:

putting the molecular sieve particles into a certain amount of deionized water, adding a certain amount of dispersing aid, and uniformly stirring and dispersing to obtain a solution A;

mixing the adhesive and the heat-conducting additive in a certain amount of deionized water, and uniformly stirring and dispersing to obtain a solution B;

adding the solution B into the solution A, and stirring and mixing uniformly to obtain a solution C;

and performing spray granulation on the solution C by using a spray drying method, and then drying to prepare the high-thermal-conductivity sound-absorbing particle.

In the embodiment, the molecular sieve particles are ZSM-5 molecular sieves with the average particle size of 2 μm, the micropore diameter of 0.3-0.7nm, the average pore diameter of 0.62nm and the Si/Al ratio of 420;

the adhesive is a polyphenyl acrylic emulsion, and the content of solid components in the emulsion is 50 percent by taking the total weight of the emulsion as 100 percent; the content of the binder solid component of the sound-absorbing particles was 7% based on 100% by weight of the total weight of the sound-absorbing particles;

the dispersing auxiliary agent is ethylene glycol, and the addition amount of the dispersing auxiliary agent is 1% of the weight of the molecular sieve particles;

the heat conduction additive is graphene, the average particle size of graphene particles is 200nm, and the addition amount of the graphene particles is 1% of the mass of the molecular sieve particles.

Example 2

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this embodiment 2, the heat conductive additive is graphene, the average particle size of the graphene particles is 200nm, and the addition amount is 3% of the mass of the molecular sieve particles.

Example 3

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this embodiment 3, the heat conductive additive is graphene, the average particle size of the graphene particles is 200nm, and the addition amount is 5% of the mass of the molecular sieve particles.

Example 4

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this embodiment 4, the heat conductive additive is graphene, the average particle size of the graphene particles is 200nm, and the addition amount is 7% of the mass of the molecular sieve particles.

Example 5

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in example 5, the heat conductive additive is alumina, the alumina particles have an average particle size of 200nm, and the addition amount is 1% of the mass of the molecular sieve particles.

Example 6

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in example 6, the heat conductive additive is alumina, the alumina fine particles have an average particle size of 200nm, and the addition amount is 3% by mass of the molecular sieve fine particles.

Example 7

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this example 7, the heat conductive additive is alumina, the alumina fine particles have an average particle size of 200nm, and the addition amount is 5% by mass of the molecular sieve fine particles.

Example 8

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this example 8, the heat conductive additive is alumina, the average particle size of the alumina particles is 200nm, and the addition amount is 7% of the mass of the molecular sieve particles.

Example 9

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this example 9, the heat conductive additive was magnesium oxide, the average particle size of the magnesium oxide particles was 200nm, and the amount of the magnesium oxide added was 1% by mass of the molecular sieve particles.

Example 10

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this example 10, the heat conductive additive is magnesium oxide, the average particle size of the magnesium oxide particles is 200nm, and the addition amount is 5% of the mass of the molecular sieve particles.

Example 11

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this example 11, the molecular sieve particles are ZSM-5 molecular sieves having an average particle size of 2 μm, a micropore diameter of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and a Si/Al ratio of 420;

the dispersing auxiliary agent is glycerol, and the addition amount of the dispersing auxiliary agent is 1% of the weight of the molecular sieve particles;

the heat conduction additive is graphene, the average particle size of graphene particles is 200nm, and the addition amount of the graphene particles is 3% of the mass of the molecular sieve particles.

Example 12

The present embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 1 in that: in this example 12, the molecular sieve particles are ZSM-5 molecular sieves having an average particle size of 3 μm, a micropore size of 0.3 to 0.7nm, an average pore size of 0.62nm, and a Si/Al ratio of 420;

the adhesive is polystyrene-vinyl acetate emulsion, and the content of solid components in the emulsion is 40% by taking the total weight of the emulsion as 100%; the content of the binder solid component of the sound-absorbing particles was 9% based on 100% by weight of the total weight of the sound-absorbing particles;

Example 13

This embodiment provides a miniature speaker module, wherein, miniature speaker module includes: an upper shell, a lower shell and a loudspeaker unit; the loudspeaker unit is arranged on the upper shell, the upper shell and the loudspeaker unit form a front cavity, the lower shell and the loudspeaker unit form a rear cavity, at least one part of the loudspeaker unit is positioned in the rear cavity, and a high-heat-conductivity sound-absorbing material is filled in the rear cavity; the upper shell and the lower shell are assembled and fixedly connected through ultrasound or glue; the loudspeaker unit has seted up the sound outlet hole towards the lateral wall (minor axis lateral wall) of back chamber, sound outlet hole surface is provided with the screen cloth, is used for keeping apart high heat conduction sound absorbing material.

In this embodiment, the lower case is further provided with a damper.

In this embodiment, the sound absorbing material with high thermal conductivity is a sound absorbing block with high thermal conductivity, and the sound absorbing block with high thermal conductivity has a primary pore with a pore diameter range of 0.3-0.7nm, a secondary pore with an average pore diameter of 0.62nm, a pore diameter range of 20-50nm, an average pore diameter of 27.5nm, and a tertiary pore with a pore diameter range of 1-100 μm, and an average pore diameter of 60 μm;

the high heat conduction sound absorption block is prepared by bonding a plurality of molecular sieve particles through an adhesive, and the preparation method comprises the following specific steps:

injecting the solution C into a mold, vacuum degassing, and freeze-drying or drying, curing and molding;

and (3) manufacturing third-level holes with the average pore diameter of 60 mu m on the surface of the solidified and molded sound absorption block by using array needles, and demolding to obtain the high-heat-conductivity sound absorption block.

the adhesive is styrene-butadiene rubber emulsion, and the content of solid components in the adhesive is 40% by taking the total weight of the emulsion as 100%; the content of the solid components of the adhesive in the sound absorption block is 12 percent based on the total weight of the sound absorption block as 100 percent;

the heat conduction additive is alumina, the average particle size of the alumina particles is 500nm, and the addition amount of the alumina particles is 1% of the mass of the molecular sieve particles.

Example 14

This embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 13 in that: in this example 14, the molecular sieve particles are ZSM-5 molecular sieves having an average particle size of 2 μm, a micropore diameter of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and a Si/Al ratio of 420;

the adhesive is polystyrene-vinyl acetate emulsion, and the content of solid components in the adhesive is 40% by taking the total weight of the emulsion as 100%; the content of the solid components of the adhesive in the sound absorption block is 15 percent based on the total weight of the sound absorption block as 100 percent;

the heat conducting additive is alumina, the average grain diameter of the alumina particles is 500nm, and the addition amount of the alumina particles is 3% of the mass of the molecular sieve particles.

Example 15

This embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 13 in that: in this example 15, the molecular sieve particles are ZSM-5 molecular sieves having an average particle size of 2 μm, a micropore size of 0.3 to 0.7nm, an average pore size of 0.62nm, and a Si/Al ratio of 420;

the adhesive is a silica sol solution, and the content of solid components in the adhesive is 30 percent by taking the total weight of the solution as 100 percent; the content of the solid component of the adhesive in the sound absorption block is 8 percent based on the total weight of the sound absorption block as 100 percent;

the dispersing auxiliary agent is polyethylene glycol, and the addition amount of the dispersing auxiliary agent is 1% of the weight of the molecular sieve particles;

the heat conducting additive is alumina, the average grain diameter of the alumina particles is 500nm, and the addition amount of the alumina particles is 5% of the mass of the molecular sieve particles.

Example 16

In this embodiment, the lower case is further provided with a damper.

soaking porous block matrix (porous material such as one or more of foam cotton, asbestos and chemical fiber block) in solution C for 10min, taking out, and drying in oven at 140 deg.C for 12 hr to obtain sound absorbing block;

in this embodiment, the molecular sieve particles are ZSM-5 molecular sieves having a particle size range of 2 μm, a micropore diameter of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and a Si/Al ratio of 420;

the adhesive is styrene-butadiene rubber emulsion, and the content of solid components in the adhesive is 40% by taking the total weight of the emulsion as 100%; the content of the solid component of the adhesive in the sound absorption block is 13 percent based on the total weight of the sound absorption block as 100 percent;

Example 17

This embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 16 in that: in this example 17, the molecular sieve particles were ZSM-5 molecular sieves having an average particle size of 2 μm, a micropore diameter of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and a Si/Al ratio of 420;

the adhesive is kaolin powder, and the content of kaolin in the sound absorption block is 7% by taking the total weight of the sound absorption block as 100%;

the dispersing auxiliary agent is polyethylene glycol, and the addition amount of the dispersing auxiliary agent is 1.5 percent of the weight of the molecular sieve particles;

Example 18

This embodiment provides a micro speaker module, which is different from the micro speaker module provided in embodiment 16 in that: in this example 18, the molecular sieve particles were ZSM-5 molecular sieves having an average particle size of 2 μm, a micropore diameter of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and a Si/Al ratio of 420;

the heat conduction additive is graphene, the average particle size of the alumina particles is 200nm, and the addition amount of the heat conduction additive is 3% of the mass of the molecular sieve particles.

Example 19

In this embodiment, the lower shell 12 is provided with a filling hole 14.

In this embodiment, the lower shell 12 is further provided with a damper 15.

In this embodiment, the sound absorbing material 31 is a mixture of sound absorbing particles with high thermal conductivity and expandable heat-conducting microspheres, the sound absorbing particles with high thermal conductivity have an average particle size of 380 μm, the particles have primary pores of 0.3-0.7nm, secondary pores of 0.62nm, secondary pores of 20-50nm, tertiary pores of 27.5nm and 1-10 μm, and the average pore size is 5.6 μm; the expandable heat-conducting microspheres have an average particle size of 270 mu m, and the proportion of the expandable heat-conducting microspheres in the heat-conducting sound-absorbing particles is 4.5 wt%;

the high-thermal-conductivity sound-absorbing particles are prepared by bonding a plurality of molecular sieve particles through an adhesive, and the preparation method comprises the following specific steps:

In this example, the molecular sieve particles are ZSM-5 molecular sieves having an average particle size of 2 μm, a micropore diameter of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and a Si/Al ratio of 420;

the adhesive is a polyphenyl acrylic emulsion; the content of solid components in the polyphenyl acrylic emulsion is 50 percent by taking the total weight of the polyphenyl acrylic emulsion as 100 percent; the content of the binder solid component in the sound-absorbing particles was 7% based on 100% by total weight of the sound-absorbing particles;

the heat conduction additive is graphene, heat conduction additive powder has a particle size of 200nm, and the addition amount of the heat conduction additive powder is 1% of the mass of the molecular sieve particles.

The preparation method of the expandable heat-conducting microsphere comprises the following specific steps:

adding a 10% by weight content (calculated with respect to the total weight of the expandable polymer) of thermally conductive additive to the expandable polymer, mixing using an internal mixer, and then extruding expandable polymer beads;

the expandable polymer beads are made into suspended expandable polymer beads by using a solvent, low-boiling-point hydrocarbon (such as one or more of petroleum ether, butane, pentane and isopentane) or halogenated hydrocarbon compound is added, and the low-boiling-point hydrocarbon or the halogenated hydrocarbon compound is infiltrated into the expandable polymer beads under the conditions of heating and pressurizing to form the expandable heat-conducting microspheres with the core-shell structure.

In this embodiment, the expandable polymer is a methyl methacrylate polymer.

Example 20

In this embodiment, the lower case is further provided with a damper.

In this embodiment, the high thermal conductivity sound-absorbing material is a high thermal conductivity sound-absorbing coating (i.e., a sound-absorbing sheet) having a thickness of 200 μm, first-stage pores having a pore diameter in the range of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and second-stage pores having a pore diameter of 20 to 50nm, and an average pore diameter of 32 nm;

the high-heat-conductivity sound-absorbing coating is prepared by directly spraying a solution containing raw material components such as molecular sieve particles, an adhesive, a dispersing aid, a heat-conducting additive and the like on the inner wall of the rear cavity of the micro-speaker module, and the specific preparation method comprises the following steps:

and spraying the solution C on the inner wall of the rear cavity of the micro-speaker module, and drying at 80-150 ℃ to obtain the high-heat-conductivity sound-absorbing coating.

the adhesive is polystyrene-vinyl acetate emulsion, and the content of solid components in the polystyrene-vinyl acetate emulsion is 40% by taking the total weight of the polystyrene-vinyl acetate emulsion as 100%; the content of the solid component of the adhesive in the sound-absorbing sheet is 12% based on 100% of the total weight of the sound-absorbing sheet;

the dispersing auxiliary agent is glycerol, and the addition amount of the dispersing auxiliary agent is 2% of the weight of the molecular sieve particles;

the heat conduction additive is graphene, heat conduction additive powder has a particle size of 200nm, and the addition amount of the heat conduction additive powder is 2% of the mass of the molecular sieve particles.

Example 21

In this embodiment, the lower shell 12 is provided with filling holes 14 for filling the high thermal conductivity sound-absorbing particles into the rear cavity 21.

In this embodiment, the lower shell 12 is further provided with a damper 15.

In this embodiment, the back cavity of the micro speaker module is sealed by glue, and He is filled in the back cavity (i.e., He is replaced with air in the back cavity of the micro speaker module provided in embodiment 1).

Because of the coefficient of heat conductivity of helium is higher than the nitrogen in the air, the cavity is filled with helium behind the miniature speaker module that this embodiment provided can increase the heat-sinking capability of cavity inner space behind the miniature speaker module, and then improves the holistic heat-sinking capability of miniature speaker module.

Comparative example 1

The present comparative example provides a micro speaker module, which is different from the micro speaker module provided in example 1 only in that a high thermal conductive and sound absorbing material is not filled in a rear cavity of the micro speaker module in the present comparative example, and accordingly, the lower case is not provided with filling holes;

wherein, the miniature speaker module includes: an upper shell, a lower shell and a loudspeaker unit; the loudspeaker unit is arranged on the upper shell, the upper shell and the loudspeaker unit form a front cavity, the lower shell and the loudspeaker unit form a rear cavity, and at least one part of the loudspeaker unit is positioned in the rear cavity; the upper shell and the lower shell are assembled and fixedly connected through ultrasound or glue; the loudspeaker unit has seted up the sound outlet hole towards the lateral wall (minor axis lateral wall) of back chamber, sound outlet hole surface is provided with the screen cloth, is used for keeping apart high heat conduction sound absorbing material.

In this comparative example, a damper was also provided on the lower case.

In the comparative example, the position of the horn unit of the lower shell of the micro loudspeaker module is hollowed, the magnetic conduction plate of the horn unit is exposed after assembly, and glue is used for plugging a gap between the magnetic conduction plate of the horn unit and the lower shell to ensure that air is not leaked;

Comparative example 2

The present comparative example provides a micro-speaker module, which is different from the micro-speaker module provided in example 1 only in that the back cavity of the micro-speaker module in the present comparative example is filled with common sound-absorbing particles;

wherein, the miniature speaker module includes: an upper shell, a lower shell and a loudspeaker unit; the loudspeaker unit is arranged on the upper shell, the upper shell and the loudspeaker unit form a front cavity, the lower shell and the loudspeaker unit form a rear cavity, at least one part of the loudspeaker unit is positioned in the rear cavity, and common sound-absorbing particles are filled in the rear cavity; the upper shell and the lower shell are assembled and fixedly connected through ultrasound or glue; the loudspeaker unit has seted up the sound outlet hole towards the lateral wall (minor axis lateral wall) of back chamber, sound outlet hole surface is provided with the screen cloth, is used for keeping apart high heat conduction sound absorbing material.

In this comparative example, the lower case was provided with a filling hole.

In this comparative example, a damper was also provided on the lower case.

or the position of the horn unit of the lower shell of the micro loudspeaker module is not hollowed, and the injection molding material is a material with high thermal conductivity coefficient such as SUS (SUS), or the lower shell of the micro loudspeaker module adopts a steel sheet structure as much as possible;

in this comparative example, the ordinary sound-absorbing particles had a particle size of 380 μm, the particles had primary pores of 0.3 to 0.7nm, secondary pores of 0.62nm in average pore diameter, 20 to 50nm in average pore diameter, tertiary pores of 27.5nm in average pore diameter and 1 to 10 μm in average pore diameter, and 6.2 μm in average pore diameter;

the common sound-absorbing particles are prepared by bonding a plurality of molecular sieve particles through an adhesive, and the preparation method comprises the following specific steps:

mixing the adhesive in a certain amount of deionized water, and uniformly stirring and dispersing to obtain a solution B;

and performing spray granulation on the solution C by using a spray drying method, and then drying to prepare the common sound-absorbing particles.

In the present comparative example, the molecular sieve particles were ZSM-5 molecular sieves having an average particle diameter of 2 μm, a micropore diameter of 0.3 to 0.7nm, an average pore diameter of 0.62nm, and a Si/Al ratio of 420;

the dispersing auxiliary agent is ethylene glycol, and the addition amount of the dispersing auxiliary agent is 1% of the weight of the molecular sieve particles.

Comparative example 3

This comparative example provides a micro-speaker module that differs from the micro-speaker module provided in example 1 only in that: the heat conducting additive is not added when the sound absorbing particles are prepared.

Test examples

The comparison of the performance and temperature rise of the micro-speaker modules provided in example 1, comparative example 1 and comparative example 2 are shown in table 1 below, wherein the temperature rise and the sound pressure level at 500Hz in table 1 are measured by methods conventional in the art. Fig. 4 is a graph showing the temperature rise of the voice coil of the micro-speaker module provided in example 1 (corresponding to the highly thermally conductive sound-absorbing particles in fig. 4), comparative example 1 (corresponding to the absence of the sound-absorbing particles in fig. 4), and comparative example 2 (corresponding to the common sound-absorbing particles in fig. 4).

TABLE 1

Scheme(s)	Sound pressure level at 500Hz	Temperature rise
			Comparative example 1	84dB	92℃
Comparative example 2	85.9dB	85℃
			Example 1	86.1dB	72℃

As can be seen from the above table 1 and fig. 4, compared with the micro speaker module provided in the comparative examples 1 and 2, the micro speaker module provided in the embodiment 1 of the present invention has the advantages that the high thermal conductive sound absorption particles are filled in the rear cavity, so that the low frequency performance of the micro speaker module is significantly improved, and the product temperature is greatly reduced.

Table 2 below shows the effect of different thermal conductive additives and their addition amounts on the performance of the prepared sound-absorbing particles F0 with high thermal conductivity in examples 1 to 10 and comparative example 3, wherein the performance of F0 and the slight drop in table 2 are measured by the conventional method in the art. Table 3 below shows the thermal conductivity of the different materials. Table 4 below shows the thermal conductivity of the high thermal conductive and sound absorbing particles prepared by adding different amounts of the thermal conductive additive and the general sound absorbing particles prepared without adding the thermal conductive additive in comparative example 3, example 1, example 3, example 5 and example 7.

TABLE 2

Sample (I)	Heat conductive additive	Additive content (wt%)	Slight fall	ΔF0(Hz)
					1			OK	129
2	Graphene	1	OK	131
					3	Graphene	3	OK	128
4	Graphene	5	OK	127
					5	Graphene	7	Slight powder falling	122
6	Al₂O₃	1	OK	129
					7	Al₂O₃	3	OK	130
8	Al₂O₃	5	Slight powder falling	127
					9	Al₂O₃	7	NG	126
10	MgO	1	OK	127
					11	MgO	5	OK	122

TABLE 3

Material	Coefficient of thermal conductivity (W/mK)
		Nitrogen gas	0.026
He	0.155
		ZSM-5 molecular sieve	0.205
Graphene	4300
		Al₂O₃	45
MgO	30-60
		AlN	150

TABLE 4

As can be seen from tables 2, 3 and 4, the acoustic performance index Δ F0 of the sound-absorbing particle with high thermal conductivity tends to gradually decrease with the increase of the addition amount of the thermal conductive additive, and the slightly dropping performance of the sound-absorbing particle with high thermal conductivity is also affected with the increase of the content of the additive, but the thermal conductivity coefficient of the sound-absorbing particle with high thermal conductivity gradually increases with the increase of the addition amount of the thermal conductive additive, so the addition amount of the thermal conductive additive is most preferably 1% to 5%; meanwhile, as can be seen from the thermal conductivity of the different materials shown in table 3, the thermal conductivity of the conventional molecular sieve material is about 10 times that of air, and the thermal conductivity of various thermal conductivity additives is higher, and the thermal conductivity of helium is about 7-8 times that of air, so that the heat diffusion capability of the rear cavity of the module can be more effectively improved by filling helium in the rear cavity of the micro-speaker module, as shown in embodiment 1 and embodiment 21, the same high thermal conductivity sound-absorbing particles are filled, and since the rear cavity of the micro-speaker module provided in embodiment 21 is filled with helium, the micro-speaker module has higher thermal conductivity, and the temperature of the speaker module can be effectively reduced.

In summary, the back cavity of the micro-speaker module provided in the embodiments of the present invention is filled with the sound absorbing material with high thermal conductivity, and the sound absorbing material with high thermal conductivity can not only improve the acoustic performance of the micro-speaker module by using the high virtual back cavity increasing coefficient, but also increase the heat dissipation capacity of the space around the speaker unit by the high thermal conductivity which is much higher than that of air, thereby improving the heat dissipation capacity of the whole micro-speaker module.

The above description is only exemplary of the invention and should not be taken as limiting the scope of the invention, so that the invention is intended to cover all modifications and equivalents of the embodiments described herein. In addition, the technical features and the technical inventions of the present invention, the technical features and the technical inventions, and the technical inventions can be freely combined and used.

Claims

1. The utility model provides a miniature speaker module which characterized in that, miniature speaker module includes: an upper shell, a lower shell and a loudspeaker unit; the loudspeaker unit is arranged on the upper shell or the lower shell, the upper shell and the loudspeaker unit form a front cavity, the lower shell and the loudspeaker unit form a rear cavity, at least one part of the loudspeaker unit is positioned in the rear cavity, and a heat-conducting sound-absorbing material is filled in the rear cavity; the upper shell is fixedly connected with the lower shell; and the side wall of the rear cavity is provided with a sound outlet.

2. The micro-speaker module as claimed in claim 1, wherein the heat-conducting sound-absorbing material contains a heat-conducting additive;

preferably, the heat conduction coefficient of the heat conduction and sound absorption material is 0.2-20W/mK;

also preferably, the thermally conductive additive includes one or more of graphene, aluminum oxide, zinc oxide, magnesium oxide, quartz powder, silicon carbide, aluminum nitride, and boron carbide;

more preferably, the particle size of the thermally conductive additive ranges from 50 to 500 nm;

further preferably, the heat conducting additive is uniformly dispersed and filled in the heat conducting sound absorbing material or coated on the surface of the heat conducting sound absorbing material.

3. The micro-speaker module as claimed in claim 1 or 2, wherein the heat-conducting and sound-absorbing material comprises sound-absorbing particles, sound-absorbing sheets or sound-absorbing blocks;

preferably, the sound absorption block is provided with a first-stage hole with the aperture range of 0.3-0.7nm, a second-stage hole with the aperture range of 20-50nm and a third-stage hole with the aperture range of 1-100 mu m;

still preferably, the thickness of the sound absorption sheet is 100-1000 μm, and the sound absorption sheet is provided with a first-stage hole with a pore diameter range of 0.3-0.7nm and a second-stage hole with a pore diameter range of 20-50 nm;

more preferably, the sound absorption sheet is prepared by directly spraying a solution containing molecular sieve particles, an adhesive and a heat conduction additive on the inner wall of the rear cavity of the micro-speaker module;

more preferably, the molecular sieve particles have a particle size in the range of 0.5 to 10 μm, a pore diameter of 0.3 to 0.7nm, and a Si/Al ratio of 200 or more, still more preferably 400 or more;

still further preferably, the molecular sieve particulates are one or more of MFI molecular sieves and/or FER molecular sieves;

still further preferably, the binder comprises an organic binder and/or an inorganic binder; the content of the organic adhesive solid component in the sound absorption sheet is 5% -20% by taking the total weight of the sound absorption sheet as 100%; the content of the inorganic adhesive in the sound absorption sheet is 4-15% by taking the total weight of the sound absorption sheet as 100%;

still further preferably, the organic binder comprises one or a combination of more of a polystyrene acrylic emulsion, a polystyrene acetic emulsion, a styrene-butadiene rubber emulsion, a polystyrene acrylate emulsion and a polyacrylate emulsion; still further preferably, the content of solid components in the organic binder is 40% to 60% based on 100% by weight of the total organic binder;

still further preferably, the inorganic binder comprises one or more of kaolin, silica sol, alumina sol, carboxymethyl cellulose;

still further preferably, the amount of the heat conductive additive is 0.5 to 20% by mass, still further preferably 1 to 5% by mass of the molecular sieve particles.

4. The micro-speaker module as claimed in claim 3, wherein the sound absorption block is made of a plurality of molecular sieve particles or sound absorption particles containing heat conductive additives bonded together by an adhesive;

preferably, the molecular sieve particles have a particle size in the range of 0.5 to 10 μm, a pore diameter of 0.3 to 0.7nm, and a Si/Al ratio of 200 or more, more preferably 400 or more;

more preferably, the molecular sieve particulates are one or more of MFI molecular sieves and/or FER molecular sieves;

also preferably, the binder comprises an organic binder and/or an inorganic binder; the content of the organic adhesive solid component in the sound absorption block is 5 to 20 percent by taking the total weight of the sound absorption block as 100 percent; the content of the inorganic adhesive in the sound absorption block is 4-15% by taking the total weight of the sound absorption block as 100%;

still more preferably, the organic binder comprises one or a combination of more of a polystyrene acrylic emulsion, a polystyrene acetic emulsion, a styrene-butadiene rubber emulsion, a polystyrene acrylate emulsion and a polyacrylate emulsion; further preferably, the content of the solid component in the organic binder is 40-60% by the total weight of the organic binder being 100%;

still more preferably, the inorganic binder comprises one or more of kaolin, silica sol, alumina sol, carboxymethyl cellulose.

5. The micro-speaker module as claimed in claim 4, wherein the method for manufacturing the sound absorption block comprises the following steps:

also preferably, the spraying time is 1-10 min;

6. The micro-speaker module as claimed in any one of claims 3-5, wherein the sound-absorbing particles have a particle size in the range of 300-700 μm, and the sound-absorbing particles have primary pores with a pore size in the range of 0.3-0.7nm, secondary pores with a pore size in the range of 20-50nm, and tertiary pores with a pore size in the range of 1-10 μm;

preferably, the sound-absorbing particles are prepared by binding a plurality of molecular sieve particles through a binder;

more preferably, the molecular sieve fine particles have a particle diameter in the range of 0.5 to 10 μm, a pore diameter of 0.3 to 0.7nm, and a Si/Al ratio of 200 or more, further preferably 400 or more;

even more preferably, the molecular sieve particulates are one or more of MFI molecular sieves and/or FER molecular sieves;

also preferably, the binder comprises an organic binder and/or an inorganic binder; the content of the organic binder solid component in the sound-absorbing particles is 5% -15% by taking the total weight of the sound-absorbing particles as 100%; the content of the inorganic binder in the sound-absorbing particles is 4-10% by taking the total weight of the sound-absorbing particles as 100%;

still more preferably, the organic binder comprises one or a combination of more of a polystyrene acrylic emulsion, a polystyrene acetic emulsion, a styrene-butadiene rubber emulsion, a polystyrene acrylate emulsion and a polyacrylate emulsion; still further preferably, the content of solid components in the organic binder is 40% to 60% by total weight of the organic binder as 100%;

7. The micro-speaker module as claimed in claim 6, wherein the sound-absorbing particles are prepared by a method comprising the steps of:

mixing molecular sieve particles, an adhesive and a heat conduction additive into slurry, granulating the slurry, and drying granules obtained after granulation to obtain sound absorption granules;

also preferably, the content of the heat-conducting additive is 1% -10%, more preferably 2% -7%, based on 100% of the total weight of the solution;

also preferably, the spraying time is 1-10 min;

8. The micro-speaker module as claimed in claim 1 or 2, wherein a certain amount of expandable microspheres are added to the heat-conducting sound-absorbing material;

preferably, the expandable microspheres are added in an amount of 1 wt.% to 10 wt.%, more preferably 2 wt.% to 6 wt.%, based on 100% by total weight of the heat conductive and sound absorbing material;

also preferably, the particle size range of the expandable microspheres is 200-400 μm;

preferably, the expandable microspheres are expandable microspheres with a core-shell structure, and the shell materials of the expandable microspheres are expandable polymers; the core structure of the expandable microspheres is prepared by a foaming agent;

still more preferably, the expandable polymer comprises one or a combination of several of polystyrene, methyl methacrylate polymer, styrene-butyl acrylate polymer, methyl methacrylate-butyl acrylate polymer, polyurethane polymer, vinyl acetate polymer, urea formaldehyde polymer and melamine formaldehyde polymer;

still more preferably, the blowing agent comprises one or more of petroleum ether, butane, pentane, and isopentane;

still more preferably, a heat conduction additive is further added to the shell layer, and the addition amount of the heat conduction additive is 1% -20% by taking the total weight of the shell layer as 100%.

9. The micro speaker module as recited in claim 1 or 2, wherein the lower shell is provided with a filling hole;

preferably, the surface of the sound outlet hole is provided with a mesh cloth;

preferably, the rear cavity of the micro-speaker module is further filled with helium.

10. A smart phone, wherein the smart phone comprises the micro-speaker module of any one of claims 1-9.