CN115914954A

CN115914954A - Micro speaker module

Info

Publication number: CN115914954A
Application number: CN202210950036.0A
Authority: CN
Inventors: 郑性哲; 河宗宪; 河贞爱
Original assignee: EM Tech Co Ltd
Current assignee: EM Tech Co Ltd
Priority date: 2021-08-10
Filing date: 2022-08-09
Publication date: 2023-04-04
Also published as: KR102577018B1; KR20230024185A

Abstract

A micro-speaker module is provided that includes a conduit in communication with a back volume vent. The structure of the present disclosure includes a duct disposed around and in communication with a vent hole formed in a housing defining a back volume, and external air flows into and out of the back volume through the duct.

Description

Micro speaker module

Technical Field

The present disclosure relates to a micro-speaker module having a conduit in communication with a vent hole that serves as a porous particle-filled hole.

Background

Fig. 1 is a plan view of a micro-speaker module according to the related art.

The micro-speaker module refers to the following modular components: in the modular component, the micro-speaker is coupled to the

housings

10 and 11 provided with the back volume and the circuit unit so as to be mounted on the multimedia device. A part of the space defined by the lower case 10 and the upper case 11 serves as an installation space of the micro-speaker, and the remaining part serves as a back volume communicating with the rear of the micro-speaker. The back volume communicates with the rear of the micro-speaker and is used for air flow so that the diaphragm provided in the micro-speaker can move smoothly.

Here, in the case where the back volume is blocked from being ventilated at all, the temperature of the internal air increases due to heat generated by the voice coil included in the micro-speaker, thereby increasing the volume inside the back volume. Therefore, a vent hole 13 is provided in the upper housing 11 defining the back volume to prevent a pressure increase when the internal pressure of the back volume 12 increases. However, if the air tightness of the back volume 12 is low, i.e. if the ventilation of the ventilation holes 13 is good, the amplitude characteristic deteriorates. In the related art, ventilation is reduced by attaching the mesh 15 to the ventilation holes 13 of the upper case 11. That is, the amplitude characteristic of the ventilation holes 13 of the related art is determined according to the ventilation of the mesh 15. However, ventilation of the mesh 15 is difficult to achieve below a certain value, and therefore, there is a problem in that tuning of the amplitude characteristics is limited.

Meanwhile, the actual back volume can be formed by filling the back volume with a porous material and using the characteristics of the porous material to adsorb and discharge air. That is, the volume of the back volume can be expanded by filling the back volume with porous particles as compared to the volume of the real back volume. In order to provide the porous particles to the inside of the back volume, filling holes 14 are separately formed in the upper case 11. In addition, in order to prevent the porous particles from escaping through the filling holes 14, the filling holes 14 are closed with a member such as an adhesive tape or a barrier.

Disclosure of Invention

An object of the present disclosure is to provide a micro-speaker module in which a vent hole for preventing a pressure increase in a back volume due to an increase in temperature and a filling hole for filling the back volume with porous particles are integrally formed, thereby reducing a production process and simplifying parts.

An aspect of the present disclosure for achieving the above object provides a micro-speaker module having a structure including a vent hole formed in a case defining a back volume and serving as an external vent hole for the back volume and as a porous particle filling hole, and a duct formed around the vent hole to communicate with the vent hole, wherein external air flows into or out of the back volume through the duct.

In the micro-speaker module provided by the present disclosure, air that is allowed to flow in and out through the vent hole communicating with the back volume passes through the duct, air flow resistance may increase, thereby preventing an increase in internal pressure caused by an increase in temperature in the back volume while airtightness of the back volume increases.

In addition, in the micro-speaker module provided by the present disclosure, since porous particles are provided through the vent holes, a production process may be reduced and parts may be simplified.

Drawings

Fig. 1 is a plan view of a micro-speaker module according to the related art;

fig. 2 is an exploded perspective view of a micro-speaker module according to a first embodiment of the present disclosure;

fig. 3 is a plan view of a micro-speaker module according to a first embodiment of the present disclosure;

fig. 4 is a view illustrating a vent structure provided in a micro-speaker module according to a first embodiment of the present disclosure;

fig. 5 is a view illustrating an air ventilation structure formed on a Flexible Printed Circuit Board (FPCB) attachment surface of a micro-speaker module according to a first embodiment of the present disclosure;

fig. 6 is a view illustrating a vent structure provided in a micro-speaker module according to a second embodiment of the present disclosure;

fig. 7 is a view illustrating a vent structure provided in a micro-speaker module according to a third embodiment of the present disclosure;

fig. 8 is a view illustrating an air ventilation structure formed in an FPCB included in a micro-speaker module according to a fourth embodiment of the present disclosure;

fig. 9 is a graph comparing electrical characteristics of a micro-speaker module according to a related art with electrical characteristics of a micro-speaker module according to an embodiment of the present disclosure;

fig. 10 is a graph illustrating an amplitude deviation of upper and lower sides of a diaphragm of a micro-speaker module according to the related art; and

fig. 11 is a graph illustrating an amplitude deviation of upper and lower sides of a diaphragm of a micro-speaker module according to the present disclosure.

Detailed Description

Hereinafter, the present disclosure will be described in more detail with reference to the accompanying drawings.

Fig. 2 is an exploded perspective view of a micro-speaker module according to a first embodiment of the present disclosure. Fig. 3 is a plan view of a micro-speaker module according to a first embodiment of the present disclosure, and fig. 4 is a view illustrating a vent structure provided in the micro-speaker module according to the first embodiment of the present disclosure.

The micro-speaker module refers to the following modular components: in the modular part, the micro-speaker 1 is coupled to the

housings

110 and 120 provided with a Flexible Printed Circuit Board (FPCB) 170 or the like so as to be mounted on the multimedia device. The back volume is defined by the lower case 110 and the upper case 120 and is a space communicating with the rear of the micro-speaker 1.

The back volume communicates with the rear of the micro-speaker 1 and generates an air flow so that the diaphragm provided in the micro-speaker 1 can be smoothly moved.

Here, in the case where the back volume is blocked without ventilation at all, the temperature of the inside air increases due to heat generated by the voice coil included in the micro-speaker, thereby increasing the pressure inside the back volume. Accordingly, a vent 130 is provided in the upper shell 120 defining the back volume to prevent a pressure increase when the internal pressure of the back volume increases. Meanwhile, the back volume is filled with a porous material for adsorbing air to improve the acoustic characteristics of the micro-speaker, and here, after the micro-speaker 1 is disposed in the lower case 110 and the upper case 120 is coupled to the lower case 110, the porous material is provided through the vent hole 130. Since a separate filling hole is not formed in the upper case 120, a production process may be reduced and parts may be simplified.

A circular stepped portion 140 is formed around the ventilation holes 130 of the upper case 110, and a groove 150 communicating with the ventilation holes 130 is formed in the stepped portion 140. A gas impermeable membrane 160 is attached to the stepped portion 140, and the membrane 160 and the groove 150 define a conduit. The inner end 152 of the groove 150 is connected to the vent hole 130, and the

outer ends

154 and 156 extend to the outside of the stepped portion 140 and are not covered by the film 160. Accordingly, air discharged through the vent 130 is discharged through the

ends

154 and 156 of the groove 150 through the conduit defined by the groove 150 and the membrane 160. That is, the back volume has a structure that achieves as much pressure equalization as possible only in the closed state, which is advantageous in terms of improving the amplitude characteristics.

This duct-type ventilation structure is a structure in which ventilation can be easily adjusted by adjusting the length/width of the semi-open duct, and is advantageous for amplitude characteristic tuning because ventilation below a specific value can also be achieved. In this case, the good amplitude characteristic means that the difference in amplitude between the upper side and the lower side of the center diaphragm for each frequency is small during excitation of the micro-speaker 1.

Meanwhile, as the length of the duct connected to the ventilation hole 130 increases, the resistance to the airflow increases and the ventilation decreases. As the cross-section of the duct decreases, the resistance to airflow increases to reduce ventilation.

Fig. 5 is a diagram illustrating an air ventilation structure formed on an FPCB attachment surface of a micro-speaker module according to a first embodiment of the present disclosure.

The pressure equalization of the back volume is not formed around the vent holes 130 of the upper case 110, but is formed on the surface 112 of the lower case 120, the surface 112 being provided for attaching the FPCB. Referring to fig. 2, the fpcb 170 is connected to the micro-speaker 1 and is pulled out from the upper case 110. Accordingly, when the groove 180 connected to the back volume is formed on the FPCB attachment surface 112, air may flow into and out of the back volume through the groove 180, and the air pressure in the back volume may be adjusted. In the FPCB attachment surface 112, the FPCB 170 blocks the upper surface of the groove 180 instead of a separate film to form a conduit. The inner end 182 of the groove 180 formed on the FPCB attachment surface 112 is located in the back volume, and the

outer ends

184 and 186 of the groove 180 need to extend to the outside the FPCB 170 so as not to be covered by the FPCB 170.

Fig. 6 is a view illustrating a vent structure provided in a micro-speaker module according to a second embodiment of the present disclosure. Referring to fig. 4, the groove for forming the guide tube according to the first embodiment of the present disclosure has one inner end and two outer ends, but as shown in fig. 6, two inner ends and two outer ends may be provided. In addition, this is a structure in which the inner ends are joined to each other and then re-branched at the outer end. In this case, the length of the catheter may be different for each path.

Fig. 7 is a diagram illustrating a vent structure included in a micro-speaker module according to a third embodiment of the present disclosure. The ventilation member 200 including the ventilation holes, the step portions, and the grooves may be separately formed and then inserted during injection molding of the upper housing 120 so as to be integrally formed. Here, the ventilation member 200 may be manufactured in advance using a die casting method using a metal material, a rubber material, an injection material, or the like.

Fig. 8 is a diagram illustrating an air ventilation structure formed in an FPCB included in a micro-speaker module according to a fourth embodiment of the present disclosure. The FPCB 170a includes a groove 180a on a surface pulled out of the housing and attached to the multimedia device, the groove 180a being connected to the back volume and having a predetermined length. To facilitate formation of the groove 180a, the FPCB 170a may include a reinforcing plate 172a at a position contacting the back volume, and the groove 180a may be formed in the reinforcing plate 172 a.

Fig. 9 is a graph comparing electrical characteristics of a micro-speaker module according to the related art with those of a micro-speaker module according to an embodiment of the present disclosure. There is no significant difference in SPL, but it can be seen that Total Harmonic Distortion (THD) is improved in the low frequency band (100 Hz to 600 Hz) due to the improvement of the amplitude balance.

Fig. 10 is a graph illustrating an amplitude deviation of upper and lower sides of a diaphragm of a micro-speaker module according to the related art, and fig. 11 is a graph illustrating an amplitude deviation of upper and lower sides of a diaphragm of a micro-speaker module according to the present disclosure.

The absolute amplitude amount is the sum of the upper amplitude absolute value and the lower amplitude absolute value, and it can be seen that the amplitude absolute amount is the same in the related art and in the present disclosure. However, referring to the amplitude balance, it can be seen that the upper and lower amplitudes are deviated by 0.07mm in the related art, whereas the upper and lower amplitudes are greatly reduced to 0.02mm in the present disclosure.

Claims

1. A micro-speaker module mounted in a multimedia device to generate sound, the micro-speaker module comprising:

a micro speaker;

a housing in which the micro-speaker is mounted and which forms a back volume around the micro-speaker;

porous particles that fill the back volume of the shell to form a substantial back volume and have air-adsorbing properties; and

a flexible printed circuit board that is drawn out through the housing and applies power to the micro-speaker,

wherein the housing includes a vent that functions as a vent between the back volume and the exterior and as a porous particle fill hole.

2. The micro-speaker module of claim 1, wherein the housing comprises a conduit extending from the vent.

3. The micro-speaker module of claim 2 wherein the conduit is formed by a recess extending from the vent and a screen covering an upper surface of the recess except for ends of the recess.

4. The micro-speaker module of claim 3 wherein the groove has a plurality of curved portions to increase the length of the conduit.

5. The micro-speaker module of claim 3 wherein the end branch of the groove is two or more ends.

6. The micro-speaker module as claimed in claim 3, wherein the screen covering the upper surface of the groove is formed of high heat resistant steel, film, paper, glass, synthetic resin, plant sheet or mesh.

7. The micro-speaker module of claim 3,

the housing has a step corresponding to the size of the screen to facilitate attachment of the screen, an

The end of the groove extends to an outer side portion outside the step.

8. The micro-speaker module of any one of claims 2-7, wherein a vent member forming a vent hole and a conduit is manufactured separately and insert injected during injection molding of the housing.

9. The micro-speaker module of claim 8, wherein the vent member is formed of a metal material, a rubber material, or an injected material.

10. The micro-speaker module of claim 1,

the flexible printed circuit board attachment surface of the multimedia device includes a groove connected to the back volume and having a predetermined length, the flexible printed circuit board is pulled out to and attached to the flexible printed circuit board attachment surface, and

the flexible printed circuit board covers an upper surface of the groove except for an end of the groove to allow the groove to serve as a conduit.

11. The micro-speaker module of claim 10 wherein the groove has a plurality of curved portions to increase the length of the conduit.

12. The micro-speaker module of claim 10, wherein the end branch of the groove is two or more ends.

13. The micro-speaker module of claim 1, wherein the flexible printed circuit board has a groove having a predetermined length connected to the back volume on a surface pulled out of the housing and attached to the multimedia device.

14. The micro-speaker module of claim 13 wherein the flexible printed circuit board has a stiffener plate in contact with the back volume and the recess is formed in the stiffener plate.