KR20110005148A - Film type piezo speaker and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A film type piezo speaker and a manufacturing method thereof are provided to effectively transfer vibrations from a piezoelectric part to a vibration plate by forming a support part, which physically supports the piezoelectric region of a speaker, in one side of a film. CONSTITUTION: A PZT device(30) is directly and completely coated between first coating films(100,101). Electrodes are connected to each other through a penetration part(110,111) formed in the first coating films. A second coating film(200,201) is additionally coated in the up/down side of a structure in order to fix the PZT device. The second coating film secludes the exposure of the electrode.

Description

Film type piezo speaker and manufacturing method therefor {FILM TYPE PIEZO SPEAKER AND MANUFACTURING METHOD THEREOF}

The present invention relates to a film type piezo speaker and a method of manufacturing the same, and in particular, to apply the piezo piezoelectric material to the film diaphragm so as not to cause breakage, peeling or degradation due to vibration, and to add a physical configuration to improve longitudinal vibration performance. A film type piezo speaker and a manufacturing method thereof are provided.

With the increase of various electronic devices and their use in daily life, new types of user interfaces that are not only of good quality but also appealing in terms of emotion are required.

One of the devices sensitively exposed to the user among these user interfaces may be a speaker that provides sound. These speakers are relatively bulky and difficult to apply in new designs, but are becoming smaller and thinner to meet the needs of users who want smaller or thinner electronics.

A general speaker changes a magnetic field of a voice coil disposed adjacent to a magnet by a signal according to a sound, and has a structure in which the diaphragm vibrates to generate sound by connecting a diaphragm to the voice coil. This can generate a high quality sound, but has a limitation in that the thickness becomes thick due to the structure of the voice coil and the diaphragm and the space between the voice coil and the magnet. This is a limitation in application to the current acoustic products with a portable device or thin structure, and also in terms of design.

Overcoming these limitations of thickness, a speaker having a film form has been introduced to be applied to portable devices or thin devices, and to enable various designs. Such a film-type speaker mainly manufactures a polymer material PVDF (Polyvinylidene fluoride) in the form of a film and then performs a polarization by applying a high voltage to the piezoelectric properties to apply the electrodes to the upper and lower parts of the film is used as a speaker.

The piezoelectric polymer material is not easy to manufacture, and since the piezoelectric polymer material must be applied to the entire diaphragm area of the speaker, the cost increases. In addition, due to the high resistance of the polymer material, when a driving voltage of several tens of V or more is applied, there is a risk of heat generation and fire in the power supply portion.

In addition, since the power required by the front piezoelectric film is large for effective driving, the 5V 500mA USB power supply, which is applied to portable devices or recently used as a power source for a PC speaker, is difficult to use and thus has low effectiveness compared to a volume.

Therefore, research on a speaker using a piezo buzzer piezoelectric buzzer which is generally used and development of a transducer modified from the configuration of such a piezo buzzer are in progress.

However, the transducer that modified the configuration of the piezo buzzer is difficult to apply to the diaphragm for volume amplification due to the increase in thickness because the manufacturing cost is greatly increased because the process is complicated and precision is required.

1 illustrates a configuration of a piezoelectric piezoelectric element 10 that is generally widely used. As shown in the drawing, the piezoelectric piezoelectric element 10 is used as a base for providing sound according to piezoelectric ceramic PZT ( 13, PZT 13 and copper plate 11 having a copper plate 11 which protects 13 and also provides an electrode function, and an upper electrode 14, which is bonded to the copper plate 11 with a dedicated adhesive 12. ) And solders 15 and 16 formed on the upper electrode 14 and extension lines, respectively.

Here, the lower portion of the PZT 13 adhered to the copper plate 11 and the dedicated adhesive 12 is in contact with each other in some areas, and the copper plate 11 is used as an electrode for forming the solder 15. In addition, the upper electrode 14 is made of a material capable of forming the solder 16 in a configuration for applying a voltage to the upper surface of the PZT 13.

FIG. 2 illustrates an application example of the piezoelectric piezoelectric element 10 as shown in FIG. 1. In the piezoelectric piezoelectric buzzer 20 as shown in FIG. 2A, the resonance structure 21 for amplifying the volume has a piezoelectric piezoelectric element 22. It is formed to surround the, has an extension line 23 for the electrical connection is exposed to the outside. This configuration is used as a simple buzzer for providing a weak volume at a relatively low voltage (5-12V), and has a sound characteristic specialized in the high-pitched region.

2B illustrates a configuration of a piezo speaker 25 using various resonance structures 26 (a panel, a signboard, a glass, a film, etc.) as a diaphragm of a speaker using the piezoelectric piezoelectric element 27 as a vibrator. There have been many examples of attaching a commercial piezoelectric piezoelectric element 27 to various resonance structures 26 as a speaker. However, it is difficult to completely fix the piezoelectric piezoelectric element 27 to the resonance structure. The adhesive property should be increased by using an adhesive such as silicone or the like.

However, when the coupling structure is installed, the thickness increases, making it difficult to manufacture the resonance structure, and does not effectively transmit vibration. In addition, when the adhesive is bonded using an adhesive such as silicon, vibration is canceled irregularly, which causes a problem of distorting sound. In addition, if you want to use a high-power speaker rather than a low-volume buzzer, the voltage is applied to the PZT element dozens of V or more, so the vibration of the piezoelectric element according to the increase of the piezoelectric piezoelectric element 27 according to the use time when attached using an adhesive There is a problem in that the separation from the resonance structure 26 occurs.

Therefore, in order to provide a high output piezo speaker that can provide a high output by ringing the diaphragm connected by providing a strong vibration to the piezoelectric piezoelectric element of small size, the limitation of the applicable output due to peeling by simple bonding of the piezoelectric piezoelectric element And, the aesthetic satisfaction is lowered by the connection line of the piezoelectric piezoelectric element 27.

In order to satisfy the recent demand for high power ultra-thin speakers and aesthetic demands in terms of design, there is an increasing need for a new type of film-type piezo speaker that solves these problems.

In order to solve the high cost, power, and configuration difficulties of the existing film-type speaker as described above, an object of the present invention, which is newly proposed to provide sufficient high output, is a piezoelectric piezoelectric electrode formed of PZT having upper and lower electrodes formed thereon. The present invention provides a film type piezo speaker and a method of manufacturing the same, which can be coated to provide aesthetics while providing sufficient output even with a small power supply such as a USB output.

Another object of the embodiments of the present invention is to coat the piezoelectric piezoelectric body using a pair of films having a through portion formed on a portion where the piezoelectric piezoelectric body is to be disposed, and then form an electrode in a region including the through portion so that the electrode is vibrated by the piezoelectric piezoelectric body. The present invention provides a film type piezo speaker and a method for manufacturing the same, which essentially block the peeling of the adhesive part due to the short circuit and the piezoelectric vibration.

Another object of the embodiments of the present invention is to form a support for physically supporting the piezoelectric region of the piezoelectric piezoelectric film-like speaker on one surface of the film to transmit the vibration of the piezoelectric piezoelectric to the film corresponding to the diaphragm more effectively. To provide a film type piezo speaker and a method of manufacturing the same.

Film-type piezo speaker according to an embodiment of the present invention, the electrode is formed, a pair of films coated with the electrode forming surface facing each other; The electrodes of each film are disposed between the pair of films so as to be connected to the upper and lower electrodes, respectively, and the upper and lower electrodes include one or more PZT elements formed in the PZT layer.

The electrodes formed on the pair of films may be printed in the same form, and the PZT elements may be connected in parallel or in series according to the electrodes of the film while being disposed in plural.

According to another embodiment of the present invention, a film type piezo speaker includes at least one PZT element having upper and lower electrodes formed on a PZT layer; A pair of films coated with the PZT element, each film diaphragm having one or more through portions formed in upper and lower film regions in which upper and lower electrodes of the PZT element are disposed; It includes an electrode formed in each region including the upper and lower through portions of the film diaphragm. Here, the electrode is formed by printing a conductor, it may further include a non-conductive coating layer on the electrode.

The PZT elements may be arranged in plural, and the electrodes may be configured to connect the PZT elements in series or in parallel.

The through part of the film diaphragm is preferably formed by arranging a plurality of through patterns in a region of upper and lower electrodes formed in the PZT element.

The PZT device may further include a support structure disposed in close contact with the film diaphragm region in which the PZT element is formed, and physically supporting one surface of the PZT element, and partially impacting the support structure in close contact with the film diaphragm of the PZT element. Absorbing material can be applied. On the other hand, the film diaphragm is deformed to form a curved surface toward the support structure may be in close contact with the support structure.

Method of manufacturing a film-type piezo speaker according to another embodiment of the present invention comprises the steps of forming a through hole in a portion corresponding to the electrode of the PZT element to be coated for a pair of coating film; Coating the coating film after disposing a PZT element in the through hole portion of the coating film in which the through hole is formed; And forming an electrode to include a region in which the through hole is formed for each of the upper and lower portions of the coated film.

The method may further include coating the exposed electrode with an insulator after the forming of the electrode.

After forming the electrode, the method may further include applying a support structure to physically support the PZT device to the PZT device portion of the coated film.

According to an embodiment of the present invention, a film-type piezo speaker and a method of manufacturing the same are coated with a piezoelectric piezoelectric body made of PZT having upper and lower electrodes formed therebetween to form an electrode, which has a thin film-like structure and is excellent in aesthetics and small as a computer USB output. It is effective to enable high output power.

According to an embodiment of the present invention, a film type piezo speaker and a method of manufacturing the same may be formed by coating an piezoelectric piezoelectric body using a pair of films having a through portion formed at a portion where the piezoelectric piezoelectric body is to be disposed, and then forming an electrode in the region including the through portion. By fundamentally blocking the electrode short circuit due to the piezoelectric piezoelectric vibration and the peeling of the adhesive part due to the piezoelectric vibration, there is an effect that can greatly increase the reliability while providing a thin high-power speaker in a low cost and a simple process.

According to an embodiment of the present invention, a film-type piezo speaker and a method of manufacturing the same may be formed on one surface of a film to physically support a piezoelectric region of a film-type speaker coated with a piezoelectric piezoelectric material, thereby effectively vibrating the vibration of the piezoelectric piezoelectric body to a vibrating plate. By transmitting to the corresponding film, there is an effect that can increase the volume and improve the acoustic characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

3 illustrates a configuration of the PZT element 30 applied to the embodiment of the present invention. As illustrated, the upper electrode 32 and the lower electrode 31 are formed on upper and lower portions of the ceramic PZT layer 33. The thickness of the PZT layer 33 may be determined according to the desired performance, but in the embodiment of the present invention, since the film coating apparatus will be used, it is appropriate to have a thickness of about several tens to several hundred μm.

The illustrated PZT element 30 is prepared by forming the lower electrode in the same form as the upper electrode on the lower portion of the PZT layer, unlike a general PZT piezoelectric element in which an upper electrode is generally formed on only one side of the PZT layer and a copper plate is applied instead of the lower electrode. do.

FIG. 4 illustrates an example of a film type speaker using the PZT element 30 provided in FIG. 3. The PZT element 30 is terminated at one end of the electrode pattern 43 on the film 41 on which the electrode patterns 43 and 44 are formed. ), The film type piezo speaker 40 may be formed by further applying a connection part 45 connecting the adjacent electrode pattern 44 and the upper electrode of the PZT element 30 to each other.

In the film type piezo speaker 40 of this type, the film 41 operates as a diaphragm for diffusing the vibration of the PZT element 30, so that the longitudinal direction of the diaphragm when the PZT element is driven at a voltage of several tens of V or more. By vibrating, it is possible to construct a high-power speaker that provides a sufficient volume.

However, in this configuration, as shown in FIG. 5, the junction part of the electrode 43 connected to the lower electrode 31 of the PZT element 30 and the bent part of the electrode 44 connected to the upper electrode 32 ( It is frequently seen that A) is peeled off or disconnected by the continuous electrode generated during the high power operation of the PZT element 30.

In particular, in the case of applying a generally known conductive adhesive (silver paste, etc.), the adhesive force is poor, and thus peels easily. Especially, in the case of the bent portion A, the electrode of the portion is physically damaged by the repeated stress of the bent portion. In addition, the part whose resistance is increased by physical damage due to high frequency variable voltage of several tens of V or more is easily disconnected while generating heat.

Therefore, such a configuration can be used at a low output (for example, a voltage of 30 V or less) that uses a low voltage, but when applied to a high output speaker configuration driven by a voltage of several tens of V or more (100 V or more in some cases). The reliability can be lowered.

FIG. 6 is a method for further improving the reliability of the electrode connection. After the coating films 51 and 54 having the same electrode patterns 52 and 55 are prepared, the electrode patterns 52 and the coating films 51 and 53 are prepared. 55, the PZT device 30 is disposed and then the coating films 51 and 53 are coated to form a film type piezo speaker to which the PZT device 30 is applied.

The PZT element 30 has a thickness of about several tens to several hundreds of micrometers, but even though it is made of a ceramic material, it is possible to secure a coating without damage even if it is put together with the coating films 51 and 55 in the coating apparatus.

FIG. 7 is an enlarged cross-sectional view of a portion in which the PZT element 30 is coated between the coating films 51 and 54, and as illustrated, a PZT layer 33 on the electrode 55 formed on the lower coating film 54. The lower electrode 31 formed on the upper surface of the PZT layer 33 is in close contact with the lower electrode 31 formed on the upper surface of the upper coating film 51. The PZT element 30 is supported by the coating adhesion of the coating films 51 and 55, and the separate adhesive component is not used because it degrades the sound quality. On the other hand, since the electrode 52, 55 on the coating film does not have an adhesive component, the PZT device 30 is fixed by the film coating around the PZT device 30.

Although the adhesive force by the coating of the films 51 and 55 is excellent, the vibration is fast and large when the PZT element 30 disposed therebetween is used as a vibrator for a high power speaker driven at a voltage of several tens of V or more. Since the force is continuously applied in the direction of adhesion (arrow) by the coating, the coating portion of the film to which the PZT element 30 is fixed is gradually opened so that the electrical connection quality is deteriorated and vibration is not transmitted to the film well. Noise is generated.

In other words, when using such a configuration, there is a practical use when driving at a relatively low voltage, but when used as a speaker of a very high output, there is a problem that the reliability is somewhat lower.

Accordingly, another embodiment of the present invention uses a film as a diaphragm, and uses a configuration that enables reliable PZT adhesion without using a separate electrode.

8 shows a basic configuration of a film type piezo speaker according to another embodiment of the present invention. As shown in the drawing, an electrode region of the PZT element 30 is disposed on upper and lower portions of the PZT element 30 having upper and lower electrodes formed on the PZT layer. Attaching and coating the coating film (100, 101) formed with the through portion (110, 111) in the corresponding portion to make the basic configuration of the speaker consisting of the basic film diaphragm and PZT vibrator.

9 is a view illustrating a configuration of a film type piezo speaker according to another exemplary embodiment of the present invention. As shown in FIG. 8, the through parts 110 and 111 of the speaker basic configuration manufactured through the process of FIG. 8 are included. Electrodes 120 and 121 are formed on the coating films 100 and 101, respectively. Through this, it is possible to stably supply power to the electrodes 120 and 121 that are gently formed while being connected to the upper and lower electrodes of the PZT element 30 through the through parts 110 and 111. Here, the through parts 110 and 111 may be configured in a single through pattern, but the through parts 110 and 111 may have a plurality in order to reliably fix the PZT element 30 to the coating films 100 and 101. It is preferred that the through patterns of the dispersion be formed as shown.

The electrodes 120 and 121 may be formed of various printing electrodes including a conductor such as silver, and may be implemented as other materials such as transparent electrodes.

Since the electrodes 120 and 121 are made of a conductive component and are exposed to the outside, an electric shock risk exists due to a driving voltage of several tens of volts. Therefore, a non-conductive coating layer may be further formed to electrically shield the upper portions of the electrodes 120 and 121. This may be done by printing a non-conductive material or by coating once again with a separate additional film.

In this case, only one PZT element 30 may be configured as shown, but may have a configuration in which a plurality of PZT elements 30 are arranged in series and connected in parallel. The capacitance component may be adjusted according to the output of the driver for driving the PZT element 30 having the capacitance component.

10 is a cross-sectional view of a film type piezo speaker according to another embodiment of the present invention shown in FIG. 9, as shown in the PZT element 30 is directly between the first coating film (100, 101) Fully adhered and coated to provide sufficient adhesion according to the coating, and stably supply power by the electrodes 120 and 121 connected through the through parts 110 and 111 formed in the first coating films 100 and 101. I can receive it. Meanwhile, if necessary, the second coating films 200 and 201 may be additionally applied to and coated on the upper and lower surfaces of the structure to block the exposure of the electrodes 120 and 121 while fixing the PZT device 30 once again. The thickness of the required diaphragm can be adjusted.

FIG. 11 is a view showing an example of applying a support structure for increasing the sound output of the film type piezo speaker as illustrated in FIG. 4 or FIG. 9, in which the second coating film is applied to the configuration of FIG. 9. Since the PZT element 30 is a longitudinal vibrating body vibrating in a direction in which sound waves are emitted, the vibration must be faithfully transmitted to the film 210 serving as a diaphragm to provide rich sound.

However, since the PZT device 30 is substantially supported by the film 210 and is floating in the air, vibration is not completely transmitted to the film 210 by the floating state.

Therefore, the frame is basically formed on the edge portion of the film 210 to tension-fix the film as a whole with stability. Such sound increase is limited depending on the frame material or elasticity and the size of the film 210. do.

Accordingly, the film 210 is bent relative to the PZT element so that the sound generated while the vibration transmission to the film 210 is well gathered into the inside of the bent film 210 to further improve the sound quality. Do.

In addition, in the present embodiment, the support structure as shown in order to provide a physical reference point for the vibration of the PZT element 30 so that the vibration of the PZT element 30 can be sufficiently transmitted to the film 210 ( 300) is configured on the rear of the film type piezo speaker. That is, compared to the case in which the PZT element 30 floats in the air and provides vibration to the film 210, the PZT element 30 provides vibration to the film 210 based on a fixed support, thereby providing substantially higher quality sound. do. On the other hand, in order to ensure the close contact between the support structure 300 and the PZT device 30 and to block the noise when the separation occurs, the shock absorbing part between the support structure 300 and the PZT device 30 in part The buffer unit 310 may be formed of a material.

In addition, as described above, the film 210 is configured to be bent toward the rear of the speaker, and the support structure 300 is fixed to the middle portion of the curved curved surface to be fixed to the film 210 according to use. It is possible to significantly reduce the possibility of the separation between the structures 300 occur.

In the above, certain preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention. .

1 is a cross-sectional view showing the configuration of a piezoelectric piezoelectric element.

2 is an example of a speaker structure to which a piezoelectric piezoelectric element is applied.

3 is a cross-sectional view of a PZT device according to an embodiment of the present invention.

4 is an example of a film type piezoelectric speaker to which a PZT element is bonded.

5 is a piezoelectric electrode structure of FIG.

6 is a configuration example of a film-type piezo speaker according to an embodiment of the present invention.

7 is a cross-sectional view of a film type piezo speaker according to an embodiment of the present invention.

8 is a structural example of the basic structure of a film-type piezo speaker according to an embodiment of the present invention.

9 is an example of a film type piezo speaker structure according to an embodiment of the present invention.

10 is a cross-sectional view of a film type piezo speaker structure according to an embodiment of the present invention.

11 is a cross-sectional view of a film type piezo speaker structure to which a support structure is added according to an embodiment of the present invention.

** Description of symbols for the main parts of the drawing **

30: PZT element 100, 101: coating film

110, 120: penetrating portion 120, 121: electrode

Claims (17)

An electrode is formed, and a pair of films coated with electrode forming surfaces facing each other; The film type piezo speaker, characterized in that the electrode of each film is disposed between the pair of films so as to be connected to the upper and lower electrodes, respectively, wherein the upper and lower electrodes include one or more PZT elements formed on the PZT layer. The film type piezo speaker according to claim 1, wherein the electrodes formed on the pair of films are printed in the same form. The film type piezo speaker according to claim 1, wherein the PZT elements are arranged in plural and connected in parallel or in series according to the electrodes of the film. At least one PZT element with upper and lower electrodes formed on the PZT layer; A pair of films coated with the PZT element, each film diaphragm having one or more through portions formed in upper and lower film regions in which upper and lower electrodes of the PZT element are disposed; The film type piezo speaker, characterized in that it comprises an electrode formed in each of the region including the upper and lower through-film diaphragm. The film type piezo speaker according to claim 4, wherein the PZT element is driven at a high voltage of 30V or higher. The film type piezo speaker according to claim 4, wherein the electrode is formed by printing a conductor. The film type piezo speaker according to claim 4, further comprising a non-conductive coating layer formed on the electrode. The film type piezo speaker according to claim 4, wherein the PZT elements are arranged in plural, and the electrodes are configured to connect the PZT elements in series or in parallel. The piezoelectric speaker of claim 4, wherein the through part of the film diaphragm is formed by arranging a plurality of through patterns in a region of upper and lower electrodes formed in the PZT element. The film type piezo speaker according to claim 4, further comprising a support structure disposed in close contact with the film diaphragm region in which the PZT element is formed to physically support one surface of the PZT element. The film type piezo speaker according to claim 10, wherein a material absorbing a part of an impact is applied between the supporting structures in close contact with the film diaphragm of the PZT element. The film type piezo speaker according to claim 10, wherein the film diaphragm is deformed to form a curved surface toward the support structure to be in close contact with the support structure. Forming a through hole in a portion corresponding to an electrode of the PZT element to be coated on the pair of coating films; Coating the coating film after disposing a PZT element in the through hole portion of the coating film in which the through hole is formed; And forming an electrode so as to include an area in which the through holes are formed for each of the upper and lower portions of the coated film. The film type piezo speaker according to claim 13, further comprising coating the exposed electrode with a non-conductor after forming the electrode. 14. The film type piezo speaker according to claim 13, further comprising applying a support structure for physically supporting the PZT element to the PZT element portion of the coated film after forming the electrode. . The film type piezo speaker according to claim 15, further comprising a buffer material applied between the support structure and the coated film. The film of claim 15, further comprising fixing the coated film to bend toward the support structure in order to increase the adhesion between the support structure and the coated film and to concentrate the vibration direction of the PZT device. Type piezo speaker.

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