WO2010104250A1

WO2010104250A1 - Diaphragm for microspeaker and manufacturing method thereof

Info

Publication number: WO2010104250A1
Application number: PCT/KR2009/004874
Authority: WO
Inventors: 이한량; 김창원; 도성환; 이상호; 권철영
Original assignee: 주식회사 비에스이
Priority date: 2009-03-10
Filing date: 2009-08-31
Publication date: 2010-09-16
Also published as: KR20100101921A; CN101835073A; TWM385182U; CN201623843U

Abstract

The present invention relates to a diaphragm for a microspeaker. The diaphragm for the microspeaker of the invention is characterized by laminating multiple thin film-shaped members made of high molecular compounds, wherein the adhesion between the members is carried out by ultrasonic welding.

Description

Diaphragm for micro speaker and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm for a microspeaker and a method for manufacturing the same. In particular, in a diaphragm composed of a plurality of layers of a thin film, a diaphragm for a microspeaker and a method for manufacturing the diaphragm can be formed at a desired position. will be.

Generally, a speaker is a device that converts an electrical signal into a voice signal.

Speakers include medium-to-large speakers that are connected to audio or amplifiers and used to amplify the volume, and are small portable devices such as mobile phones, laptops, MP3 players, and earphones. There are also small speakers for sound equipment. Such a compact speaker is commonly referred to as a micro speaker, and the present invention relates to a diaphragm used in such a micro speaker.

In order to increase the efficiency of the diaphragm, the conventional micro speaker diaphragm has to be small in size, and thus, a thin, diaphragm diaphragm having light weight and flexibility is used. However, since the thin-film diaphragm is smaller in size than the diaphragm used in the medium and large size speakers, it is difficult to faithfully reproduce a desired sound band such as a high band and a low band.

Conventionally, in order to overcome this difficulty, a thin film-like film is provided with several layers, each molded into a desired shape and size, and then bonded to each other to be used as a diaphragm. At this time, in order to bond a plurality of films to each other, a method of using an adhesive or applying heat and pressure has been mainly used.

However, when a plurality of films are bonded to each other with an adhesive, there is a problem that it is difficult to uniformly apply the adhesive to the entire surface to be bonded. This causes a problem that the thickness deviation of the joint surface occurs.

In addition, since the adhesive has some fluidity and requires time to cure, it is difficult to join a plurality of layers in the desired precise position and there is a problem in that it requires time to wait for the next fixing.

In addition, the use of a method of applying heat and pressure to mutually join the desired portions of the plurality of layers also has a problem in that a variation in bonding position occurs because heat and pressure must be applied directly to the molding die.

In addition, when it is necessary to bond a plurality of layers of different materials for the acoustic characteristics of the speaker, there is a problem that depending on the material may cause a chemical reaction with the adhesive used.

An object of the present invention, in the diaphragm composed of a plurality of layers, by bonding the plurality of layers to each other by the ultrasonic fusion method, the bonding is precisely performed at a desired position, the thickness variation in the bonded portion can be minimized The present invention provides a diaphragm for a micro speaker and a method of manufacturing the same, which can reduce variation in product characteristics and obtain high quality acoustic characteristics.

In order to achieve the above object, in the diaphragm for micro speaker of the present invention, the diaphragm is formed by stacking a plurality of members in the form of a thin film made of a polymer compound, and the attachment between the plurality of members is made by an ultrasonic fusion method. It is characterized by.

On the other hand, the plurality of members includes a first member located at the bottom and a second member located at an upper portion thereof, and the first member is divided into an inner portion which is a center portion and an outer portion positioned outside of the inner portion. Preferably, the second member has a size corresponding to an inner portion of the first member, is located on the inner portion, and at least a portion of an outer circumferential portion of the second member is attached to the first member.

The entire outer circumferential portion of the second member is attached to the first member, and a gas layer is formed between the first member and the second member.

On the other hand, it is preferable that at least one additional member is provided between the first member and the second member.

According to another aspect of the present invention, a method of manufacturing a diaphragm for a micro speaker is a method of manufacturing a diaphragm, which is used in a micro speaker and is formed by combining a plurality of thin film-like members made of a polymer compound, and preparing a mold for preparing a mold. ; A first member molding step of placing the first member, which is located at the bottom of the plurality of members, on the molding mold and shaping it into a desired shape; A second member disposing step of placing a second member on the molded first member; And an ultrasonic fusion step of attaching portions of the first member and the second member to be attached to each other by an ultrasonic fusion method.

On the other hand, the first member is preferably fixed to the molding die by a vacuum suction method.

In addition, the second member disposing step, it is preferable to include positioning at least one additional member between the first member and the second member.

On the other hand, the molded first member is divided into an inner portion which is a central portion and an outer portion located outside of the inner portion, the second member has a size corresponding to the inner portion of the first member, the first member Located above, the ultrasonic welding step, it is preferable to bond the entire outer peripheral portion of the second member to the first member.

In the ultrasonic fusion step, the entire outer circumferential portion of the second member is bonded to the first member, and the bonding is performed such that a gas layer is formed between the first member and the second member.

According to the diaphragm for micro-speakers and the manufacturing method thereof according to the present invention, it is possible to obtain the effect that the thickness of the portion where the plurality of layers are joined can be made uniform.

In addition, since the joining of a plurality of layers can be made precisely at a desired position, the effect of precise molding of each layer can be obtained.

In addition, by not using an adhesive as in the prior art, it is possible to reduce manufacturing defects and to improve yield, and to obtain an effect of automation of production.

1 is a schematic perspective view of a diaphragm for a micro speaker of one embodiment according to the present invention;

FIG. 2 is a schematic cross-sectional view of the micro speaker equipped with the diaphragm of FIG. 1;

3 is a cross-sectional view of the diaphragm for the micro speaker of FIG.

4 is a schematic cross-sectional view of a diaphragm for a micro speaker of another embodiment according to the present invention;

5 and 6 are views for explaining a method of manufacturing a diaphragm for a micro speaker of the present invention,

7 is a flow chart of a microphone assembly manufacturing method of an embodiment according to the present invention.

1 to 3 attached to the diaphragm for a micro speaker of an embodiment of the present invention will be described in detail.

1 is a perspective view of a diaphragm 1 of one embodiment according to the present invention, and FIG. 2 is a diagram illustrating, as a cross-sectional view, a micro speaker 100 having a general configuration in which the diaphragm 1 of FIG. 1 is employed. 3 is a schematic cross-sectional view of the diaphragm of FIG. 1.

The diaphragm 1 for a micro speaker of the present embodiment is a diaphragm used for a micro speaker of a small acoustic device such as a mobile phone, earphone, MP3, or the like, and is composed of a plurality of thin film-like members made of a polymer compound.

Since the diaphragm 1 for micro speakers is generally small in size, in order to obtain desired acoustical characteristics, it is comprised with several thin film members with a different shape and material. The diaphragm may be formed of one film, but the diaphragm of the present invention is configured by stacking at least two or more films in order to form a desired acoustic characteristic.

On the other hand, Figure 2 is illustrated in a phantom perspective that the general micro-speaker 100 to which the diaphragm 1 for the micro-speaker of this embodiment is applied is cut in half.

The micro speaker 100 includes a frame 101, a yoke 102, a permanent magnet 103, a plate 104, and a base coil 105. A cover (not shown) is usually fixed to the upper portion of the frame 101. At this time, in the diaphragm 1 of this embodiment, the outer peripheral part 12 is fixed to the frame 101. As shown in FIG. The upper end of the base coil 105 is fixed to the lower surface of the junction portion 30 of the diaphragm 1.

In the micro speaker diaphragm 1 of the present embodiment, the first member 10 and the second member 20 are stacked.

The first member 10 and the second member 20 is a polymer film of a thin film form. The polymer compound includes polyethylene, polyurethane, and the like. The first member 10 and the second member 20 are each selected from various polymer compound films in consideration of physical and chemical properties such as stiffness, softness, melting point, etc. of each material to obtain desired acoustic properties. It is done. The first member 10 and the second member 20 may be made of the same material as needed, or may be made of different materials.

On the other hand, the diaphragm 1 for a micro speaker of this embodiment consists of a dome part which is a slightly convex part of the upper part, and the edge part surrounding the dome part, as shown in FIG. The edge 12 of the edge portion is formed flat and fixed to the frame 101 of the micro speaker 100.

In addition, the part which couple | bonds a dome part and an edge part mutually is called the junction part 30. FIG. As described above, the upper end of the voice coil 105 (refer to FIG. 2) is coupled to the lower surface of the junction part 30.

In the present embodiment, the first member 10 is divided into an inner portion corresponding to a dome portion and an outer portion corresponding to an edge portion located outside the inner portion. The second member 20 has a size corresponding to the inner portion of the first member 10 and is located above the inner portion.

Therefore, the dome portion is composed of a plurality of layers in which the second member 20 is stacked on the first member 10, and the edge portion is composed of a single layer of the first member 20. The dome and edge sections each have a different range of reproduction, and thus are configured to have different physical characteristics.

The bonding portion 30 is a portion where the outer circumferential portion of the second member 20 and the corresponding portion of the first member 10 are joined to each other by an ultrasonic fusion method.

Ultrasonic welding is generally a method of bonding processing of secondary polymer compounds, and is a method of bonding polymer compounds using vibration of sound waves. In general, the power of 50 / 60Hz is made into electric energy of 15KHz ~ 20KHz through the oscillator, and then converted into mechanical vibration energy through the converter and the booster, and then transmitted to the workpiece through the tool horn, The frictional heat is generated, and the joining surface of the workpiece is dissolved and bonded to form a molecular bond.

On the other hand, in the present embodiment, the entire outer peripheral portion of the second member 20 is joined to the first member 10 by an ultrasonic fusion method. However, the present invention is not limited thereto, that is, the first member and the second member may be intermittently bonded to each other along the outer circumferential portion instead of the entire outer circumferential portion of the second member.

In addition, in the case of the present embodiment, it is exemplified that the diaphragm 1 for the micro speaker is circular, but the present invention is not limited thereto. In other words, the present invention is a structure in which a diaphragm is formed by stacking films of two or more polymer compounds, and the bonding between the films is performed by ultrasonic fusion method. Similarly, it can be applied to a shape in which both sides of the quadrangle are arcs.

Meanwhile, in the present exemplary embodiment, referring to FIG. 3, a gas layer 40 in which gas is formed is formed between the first member 10 and the second member 20 positioned in the dome portion. The gas layer 40 is filled with general air. Since the entire outer circumferential portion of the second member 20 is attached to the first member 10, such a gas layer 40 is trapped in a space formed between the first member 10 and the second member 20. Will be.

4 illustrates a diaphragm 1a for a micro speaker of another embodiment according to the present invention.

The micro speaker diaphragm 1a further includes an additional member 22a between the first member 10a and the second member 20a. The additional member 22a may be a film made of a polymer compound like the first and second members, or may be made of various materials different from this.

Since the additional member 22a is located in the space formed between the first member 10a and the second member 20a, the additional member 22a may be made of a material that cannot be applied to the ultrasonic welding method. In addition, when the additional member is made of a polymer compound, it is also possible to position the outer peripheral portion of the additional member between the first and second members, and then attach them all by an ultrasonic fusion method.

On the other hand, in the present embodiment, the addition member 22a, for example, but is provided with one, two or more may be provided depending on the embodiment.

According to the diaphragm for a microspeaker of the present invention, since the bonding between the first member and the second member is made by an ultrasonic fusion method, there is an advantage that the thickness of the bonding portion is almost constant. As a result, the acoustic characteristics of the product are uniform and the defect rate is low.

In addition, there is an effect that the bonding between the first member and the second member can be made precisely at a desired position.

In addition, it is possible to form a gas layer between the first member and the second member, there is an effect that can obtain the characteristics of the desired diaphragm. In addition, it is also possible to insert one or more additional members into the gas layer, thereby achieving the effect of controlling the thickness of the diaphragm or adjusting the acoustic characteristics.

On the other hand, as another aspect of the present invention, a manufacturing method suitable for producing the above-mentioned diaphragm for a micro speaker is disclosed.

The method of manufacturing a diaphragm for a micro speaker according to an embodiment of the present invention is a method of manufacturing a diaphragm formed by combining a plurality of thin film-like members made of a polymer compound, and preparing a mold (S1) and forming a first member. (S2), the second member arrangement step (S3) and ultrasonic welding step (S4) is made.

The mold preparation step S1 is a step of preparing a mold 40 having a shape corresponding to the shape of the first member 10 in order to form the first member 10 in a desired shape.

The first member forming step (S2) is a step of placing the first member 10, which is located at the bottom of the plurality of members, on the molding die 40 and molding to a desired shape. That is, the first member 10 is molded by using another mold (not shown) that puts a film of a polymer compound material on the mold 40 and exerts a force from top to bottom.

In the next step, the second member arranging step S3 is a step of placing the second member on the molded first member 10. After positioning the second member 20 at a desired position of the first member 10, the ultrasonic welding step (S4) of the next step is performed.

On the other hand, in the present embodiment, the first member 10 is divided into an inner portion which is a central portion and an outer portion located outside of the inner portion, and the second member 20 corresponds to the inner portion of the first member 10. It is sized to be positioned on the first member.

The ultrasonic welding step S4 is a step of attaching the portions to be attached to the first member 10 and the second member 20 to each other by an ultrasonic welding method.

Referring to FIG. 5, after the first member 10 is placed on the mold 40 and the second member is placed on the mold 40, the tool horn 42 for ultrasonic welding is ultrasonically applied to a portion 30 to be bonded to each other. Performing fusion is illustratively shown. General description of the ultrasonic welding method is as described above.

The manufacturing method of this embodiment is for manufacturing the diaphragm 1 for the micro speaker of the first embodiment described above. Therefore, in the ultrasonic welding step S4, the entire outer peripheral portion of the second member 20 is bonded to the first member 10.

However, the present invention is not limited thereto. That is, depending on the embodiment, it is also possible to join only a part of the second member 20 instead of the entire outer peripheral part. It is also possible to intermittently join in the circumferential direction along the outer circumference, and also form a joining portion spaced apart along the outer circumference, and the joining direction of each joining portion may be in the radial direction. In the form of umbrellas, the joints are made only to a part of the length close to the outer shell, not the entire length of the umbrellas. On the other hand, according to the embodiment, the shape of the diaphragm may be in various shapes such as square, square, oval, track, and the like, rather than circular.

And, in the present embodiment, the ultrasonic welding step (S4) is bonded to form a gas layer 40 (see Fig. 3) between the first member 10 and the second member 20. That is, the second member 20 is in contact with the first member 10 only in the junction portion 30, and the remaining portion except for this is spaced apart from the first member 10 to form a gas layer 40 therebetween.

On the other hand, in the present embodiment, the first member 10 is fixed to the molding die 40 by a vacuum suction method.

That is, when the first member 10 is formed in a desired shape and then the molded first member 10 is placed on the mold 40, the first member 10 adheres closely to the mold by a vacuum adsorption method. The combined state will be maintained.

When the first member 10 is maintained at a predetermined position on the mold in this state, it is possible to accurately position the second member 20 at the desired position on the first member 10. In addition, since the position of the first member 10 does not change even after the ultrasonic fusion step is performed, ultrasonic fusion can be accurately performed at a desired point.

In addition, after the first member 10 is molded, the second member 20 is lifted up in a vacuum suction state in succession, and ultrasonic welding is performed, thereby improving workability.

On the other hand, in the method of manufacturing a diaphragm for a micro speaker of another embodiment, in the second member arrangement step S3, at least one additional member 22a is disposed between the first member 10a and the second member 20a. Positioning is included.

Referring to FIG. 6, in arranging the second member 20a, after the additional member 22a is positioned between the first member 10a and the second portion 20a, the ultrasonic welding step (the next step) is performed. S4) is performed. The description regarding the additional member 22a is applied as it is with respect to the diaphragm 1a.

According to the method of manufacturing a diaphragm for a micro speaker of the present invention, since the first member and the second member constituting the diaphragm are joined by the ultrasonic welding method, there is an advantage that the thickness variation of the joining portion can be minimized.

In addition, because of the ultrasonic fusion method, when combining the film member with the conventional adhesive, there is a disadvantage that the chemical reaction between the first and second members and the additional member and the adhesive may occur, but in the case of the present invention there is no such disadvantage.

When the first member is fixed to the molding die by vacuum suction, the position of the first member can be fixed accurately, and the joining position with the second member can be precisely controlled and the work efficiency is improved. It is effective.

Claims

As a diaphragm used for micro speakers,

The diaphragm is formed by stacking a plurality of members in the form of a thin film made of a polymer compound,

Attachment between the plurality of members is a diaphragm for a micro speaker, characterized in that made by the ultrasonic welding method.
The method of claim 1,

The plurality of members includes a first member positioned at the bottom and a second member positioned at an upper portion thereof.

The first member is divided into an inner portion which is a central portion thereof and an outer portion located outside of the inner portion,

The second member has a size corresponding to an inner portion of the first member and is located above the inner portion;

And at least a portion of an outer circumferential portion of the second member is attached to the first member.
The method of claim 2,

The entire outer periphery of the second member is attached to the first member,

Diaphragm for a micro-speaker, characterized in that the gas layer is formed between the first member and the second member.
The method of claim 2,

At least one additional member is provided between the first member and the second member, the diaphragm for a micro speaker.
A method for manufacturing a diaphragm which is used in a micro speaker and is formed by combining a plurality of thin film-like members made of a polymer compound,

A mold preparation step of preparing a mold;

A first member molding step of placing the first member, which is located at the bottom of the plurality of members, on the molding mold and shaping it into a desired shape;

A second member disposing step of placing a second member on the molded first member; And

Ultrasonic welding step of attaching to the mutually attached portions of the first member and the second member to be mutually bonded by an ultrasonic welding method comprising the diaphragm for a micro speaker.
The method of claim 5,

The first member is a manufacturing method of the micro-speaker diaphragm, characterized in that fixed to the molding die by a vacuum suction method.
The method of claim 5,

The second member disposing step, the method of manufacturing a diaphragm for a micro speaker, characterized in that to include at least one additional member between the first member and the second member.
The method of claim 5,

The molded first member is divided into an inner portion which is a center portion and an outer portion located outside of the inner portion,

The second member has a size corresponding to an inner portion of the first member, and is located above the first member,

The ultrasonic welding step, the manufacturing method of the micro-speaker diaphragm, characterized in that for bonding the entire outer peripheral portion of the second member to the first member.
The method of claim 8,

In the ultrasonic welding step, the entire outer circumference of the second member is bonded to the first member, and the micro-speaker diaphragm is manufactured such that a gas layer is formed between the first member and the second member. Way.