KR20230154577A - The piezoelectric speaker and manufacturing method thereof - Google Patents

Abstract

The present invention includes a vibrating unit including a vibrating piezoelectric element layer, an upper case covering the vibrating unit in one direction, a lower case covering the vibrating unit in the other direction, an upper coupling part disposed in the upper case, and a lower coupling portion disposed in the lower case. It includes a case coupling part that connects the upper coupling part and the lower coupling part, and an ultrasonic welding part that fuses and joins the upper coupling part and the lower coupling part, making it easier to manufacture the piezoelectric speaker and dramatically reducing the number of working hours and costs. You can save by

Description

Piezoelectric speaker and method of manufacturing the same {THE PIEZOELECTRIC SPEAKER AND MANUFACTURING METHOD THEREOF}

The present invention relates to a piezoelectric speaker and a method of manufacturing the same, and more specifically, to a piezoelectric speaker and a method of manufacturing the same that reduce man-hours and manufacturing costs.

A piezoelectric speaker is a speaker that generates sound by driving a piezoelectric element. When a piezoelectric speaker is attached to a large flat surface such as a desk, the flat plate vibrates due to piezoelectric vibration, which can be implemented as a speaker. These piezoelectric elements are highly brittle and can easily break at the slightest carelessness. Therefore, after placing the piezoelectric element inside the case, the case goes through a process of assembling it.

In the case of the prior art, the piezoelectric element was placed inside the case, and then the cases were joined together top and bottom using adhesive. In this case, if the adhesive is not applied at the correct location or if the amount applied is large, a problem occurs where the adhesive overflows from the adhesive location. In addition, even after joining the upper and lower cases, they must be left unattended until the adhesive dries sufficiently, which has the disadvantage of requiring a separate drying space.

One embodiment of the present invention aims to provide a piezoelectric speaker and a method of manufacturing a piezoelectric speaker that reduces man-hours and manufacturing costs.

In order to achieve the above-mentioned object, a piezoelectric speaker according to an embodiment of the present invention includes a vibrating part including a vibrating piezoelectric element layer, an upper case covering the vibrating part in one direction, and a lower case covering the vibrating part in the other direction. , a case coupling portion including an upper coupling portion disposed in the upper case and a lower coupling portion disposed in the lower case, and ultrasonic fusion that is disposed between the upper coupling portion and the lower coupling portion and joins the upper coupling portion and the lower coupling portion by fusion. It is characterized by including wealth.

In addition, the upper case is disposed on the upper plate and the edge of the upper plate and includes an upper side wall portion surrounding the upper coupling portion in plan, and the lower case is disposed on the lower plate and the edge of the lower plate and surrounds the lower coupling portion in plan. It is characterized in that it includes a lower side wall portion.

In addition, the upper coupling portion includes an upper coupling protrusion extending parallel to the upper side wall portion, and an insertion groove disposed between the upper coupling protrusion and the upper side wall portion, and the lower coupling portion includes an insertion projection inserted into the insertion groove. Do it as

In addition, the ultrasonic welding portion further includes a welding protrusion protruding from the upper surface of the insertion protrusion into the insertion groove, and the welding protrusion is welded by ultrasonic welding to fill the insertion groove.

In addition, the lower side wall portion protrudes from the lower plate toward the upper side wall portion, the upper side wall portion protrudes from the upper plate toward the lower side wall portion, and the upper surface of the lower side wall portion and the lower surface of the upper side wall portion are in contact.

Additionally, the insertion protrusion is characterized in that it protrudes higher from the upper surface of the lower side wall.

In addition, the lower surface of the upper engaging protrusion is characterized in that it is disposed between the upper and lower surfaces of the insertion protrusion.

Additionally, the vibrating unit is characterized in that it is coupled to either the upper case or the lower case.

In addition, the case coupling portion is disposed at the edge of the upper case in plan view, extends from the first side to the second side along the edge of the upper case, and has a terminal opening defined between the first side and the second side. Do it as

Additionally, the upper side wall portion and the lower side wall portion are characterized by having terminal openings.

In addition, the terminal opening is characterized in that it is recessed into the inside of at least one of the upper case and the lower case in plan view.

In addition, the vibration unit includes a piezoelectric element layer, a first electrode coupled to one side of the piezoelectric element layer, and a second electrode coupled to the other side of the piezoelectric element layer, and is connected to the first terminal and the second electrode connected to the first electrode. It is characterized in that it further includes a terminal unit including a connected second terminal.

In addition, the method of manufacturing a piezoelectric speaker according to an embodiment of the present invention includes the steps of coupling a vibrating part including a piezoelectric element layer to one of the upper case and the lower case, combining the upper coupling part and the lower coupling part, and combining the upper coupling part. It is characterized in that it includes the step of welding the upper and lower coupling parts with ultrasonic waves to form an ultrasonic fusion part that joins the upper case and the lower case.

According to the present invention, the upper case and the lower case can be easily fused and joined by applying vibrational friction energy with ultrasonic waves while the upper case and the lower case are aligned.

Since the lower coupling part is ultrasonic welded while inserted into the upper coupling part, it can be stably joined without displacement even if ultrasonic vibration friction energy is applied.

Since the joining is completed through fusion and solidification through ultrasonic welding, the assembly process is simple and the number of working hours and manufacturing costs can be reduced.

1 is a plan view schematically showing a piezoelectric speaker according to an embodiment of the present invention.
FIG. 2 is a bottom view of the piezoelectric speaker shown in FIG. 1.
Figure 3 is a cross-sectional view schematically showing a cross-section taken along AA in Figure 1.
Figure 4 is a cross-sectional view schematically showing a cross-section taken along BB in Figure 1.
Figure 5 is an enlarged view of C in Figure 4.
6 to 8 are diagrams for explaining ultrasonic welding of case joints.
FIG. 9 is a diagram showing the vibrating unit shown in FIG. 3.
Figure 10 is a bottom view of the upper case shown in Figure 4.
Figure 11 is a plan view of the lower case shown in Figure 4.

Like reference numerals refer to substantially the same elements throughout the specification. In the following description, detailed descriptions of configurations and functions known in the technical field of the present invention and cases not related to the core configuration of the present invention may be omitted. The meaning of terms described in this specification should be understood as follows.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship of two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as 'after', 'successfully after', 'after', 'before', etc., 'immediately' or 'directly' Unless used, non-consecutive cases may also be included.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may also be the second component within the technical spirit of the present invention.

“X-axis direction,” “Y-axis direction,” and “Z-axis direction” should not be interpreted as only geometrical relationships in which the relationship between each other is vertical, and should be used within a wider scope within which the configuration of the present invention can function functionally. It can mean having direction.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, “at least one of the first, second, and third items” means each of the first, second, or third items, as well as two of the first, second, and third items. It can mean a combination of all items that can be presented from more than one.

Each feature of the various embodiments of the present invention can be combined or combined with each other, partially or entirely, and various technological interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

Hereinafter, a piezoelectric speaker 1 according to an embodiment of the present invention will be described with reference to the drawings.

Figure 1 is a plan view schematically showing the piezoelectric speaker 1 according to an embodiment of the present invention, Figure 2 is a bottom view of the piezoelectric speaker 1 shown in Figure 1, and Figure 3 is taken along the line A-A in Figure 1. Figure 4 is a cross-sectional view schematically showing a cross-section cut along B-B in Figure 1, Figure 5 is an enlarged view of C in Figure 4, and Figures 6 to 8 are case combinations. This is a diagram for explaining ultrasonic welding of the unit 40, and FIG. 9 is a diagram showing the vibrating unit 10 shown in FIG. 3.

Referring to Figures 1 to 9, the piezoelectric speaker 1 according to an embodiment of the present invention is intended to increase productivity and facilitate the manufacture of a speaker with a thin, simple structure. The piezoelectric speaker 1 according to an embodiment of the present invention includes a vibrating part 10, an upper case 20, a lower case 30, a case coupling part 40, and an ultrasonic welding part 5.

The vibrating unit 10 may generate vibration. The vibrating unit 10 includes a piezoelectric element layer 100, a first electrode 110, and a second electrode 120. The first electrode 110 and the second electrode 120 are connected to a terminal 60 that is connected to an external power source. The terminal 60 includes a first terminal 600 and a second terminal 610. The first terminal 600 is connected to the first electrode 110. The second terminal 610 is connected to the second electrode 120. Power may be applied to the first electrode 110 and the second electrode 120 through the terminal 60.

The piezoelectric element layer 100 may generate vibration by the power applied to the first electrode 110 and the second electrode 120. Vibration caused by the piezoelectric element layer 100 is transmitted to the upper case 20 and the lower case 30. Therefore, when the upper case 20 and the lower case 30 are placed or combined on a vibrating body, sound can be generated by vibration. The vibrating unit 10 may be bonded face-to-face to the inner surface of the upper case 20 or the lower case 30. In one embodiment, the front surface (lower or upper surface) of the vibrating unit 10 may be attached to a bonding layer (not shown). The bonding layer attached to the front of the vibrating unit 10 may be bonded face-to-face to the inner surface of the upper case 20 or the lower case 30. Accordingly, the vibration generated in the vibrating unit 10 is sufficiently transmitted to the upper case 20 or the lower case 30, and transmission efficiency can be increased. Additionally, the piezoelectric element layer 100 is highly brittle due to its characteristics. Therefore, the piezoelectric element layer 100 is likely to be broken or broken by impact. Since the piezoelectric element layer 100 is coupled face-to-face to the upper case 20 and the lower case 30, breaking or breaking can be prevented. Additionally, the bonding layer is capable of mitigating impact, thereby reducing the brittleness problem. To further alleviate problems due to brittleness, an elastic member (not shown) may be further disposed between the piezoelectric element layer 100 and the case.

The piezoelectric element layer 100 may include one or more materials selected from the group consisting of PZT, BaTiO3, PbTiO3, PbZrO3, ZnO, MgO, and CdO. The elastic member (not shown) additionally attached to the piezoelectric element layer 100 is not limited to PDMS, but may include polyvinylidene fluoride (PVDF), epoxy, and silicon.

Various polymer materials such as silicon rubber, polyurethane (PU), and polymethylmethacrylate (PMMA) can be applied.

The upper case 20 may cover the upper surface of the vibrating unit 10. The lower case 30 may cover the lower surface of the vibrating unit 10. The upper case 20 includes an upper plate 200 and an upper side wall portion 210. The lower case 30 includes a lower plate 300 and a lower side wall portion 310. The upper plate 200 and lower plate 300 have a flat plate shape. The vibrating unit 10 may be coupled to the upper plate 200 or the lower plate 300. The upper plate 200 or lower plate 300 on which the vibrating unit 10 is not disposed may have a through hole.

The case coupling part 40 may include an upper coupling part 400 and a lower coupling part 410. The upper coupling portion 400 is disposed in the upper case 20. In one embodiment, the upper coupling portion 400 includes an upper coupling protrusion 401 and an insertion groove 402. The upper coupling protrusion 401 extends parallel to the upper side wall portion 210. The upper coupling protrusion 401 is disposed on the inside of the upper side wall portion 210. The insertion groove 402 is disposed between the upper engaging protrusion 401 and the upper side wall portion 210. Accordingly, the insertion groove 402 may be defined by the outer surface of the upper engaging protrusion 401, the lower surface of the upper plate 200, and the inner surface of the upper side wall portion 210.

The lower coupling portion 410 is disposed in the lower case 30. In one embodiment, the lower coupling portion 400 includes an insertion protrusion 411. The insertion protrusion 411 may protrude from the lower plate 300 and the lower side wall portion 310 toward the upper case 20. When the upper case 20 and the lower case 30 are combined, the insertion protrusion 411 is inserted into the insertion groove 402. Therefore, when the upper case 20 and the lower case 30 are combined, the assembly positions can be aligned. Additionally, the insertion protrusion 411 may be supported in the inner and outer directions of the upper case 20 by the upper side wall portion 210 and the upper coupling protrusion 401. Therefore, during ultrasonic welding, which will be described later, no additional measures are needed to fix the joint state of the upper case 20 and the lower case 30, making ultrasonic welding work easy.

The ultrasonic welding portion 50 is disposed between the upper coupling portion 400 and the lower coupling portion 410. The ultrasonic welding portion 50 fuses and joins the upper coupling portion 400 and the lower coupling portion 410. The ultrasonic fusion portion 50 may be formed by ultrasonic welding at the top of the upper coupling portion 400 or the lower coupling portion 410 when the upper coupling portion 400 and the lower coupling portion 410 are joined. The ultrasonic fusion portion 50 fills the insertion groove 402 with its melt.

In one embodiment, the ultrasonic welding portion 50 further includes a welding protrusion 500. The welding protrusion 500 protrudes from the upper surface of the insertion protrusion 411 into the insertion groove 402. The welding protrusion 500 has a smaller width than the insertion protrusion 411. Additionally, the fusion protrusion 500 has a height that is smaller than the height of the insertion protrusion 411. In one embodiment, the fusion protrusion 500 may have a triangular shape that gradually becomes smaller in cross section from the insertion protrusion 411 toward the upper case 20. Therefore, during ultrasonic welding, melting occurs around the fusion protrusion 500, and melting of the insertion protrusion 411 can be suppressed. Accordingly, the height of the insertion protrusion 411 can be maintained while securing the coupling force by filling the insertion groove 402. As a result, the separation distance between the upper case 20 or lower case 30 and the vibrating unit 10 can be secured. Accordingly, the thickness of the piezoelectric speaker 1 can be minimized while preventing damage in situations such as bending due to the brittleness of the piezoelectric element layer 100.

The upper side wall portion 210 is disposed at the edge of the upper plate 200. The upper side wall portion 210 is arranged to surround the upper coupling portion 400 in plan view. The lower side wall portion 310 is disposed at the edge of the lower plate 300. The lower side wall portion 310 is arranged to surround the lower coupling portion 410 in plan. The upper side wall portion 210 protrudes from the upper plate 200 toward the lower side wall portion 310. The lower side wall portion 310 protrudes from the lower plate 300 toward the upper side wall portion 210. The lower surface of the upper side wall portion 210 and the upper surface of the lower side wall portion 310 are disposed in contact with each other. That is, the lower surface of the upper side wall portion 210 and the upper surface of the lower side wall portion 310 are coupled in close contact. As a result, the inside of the case can be protected and the molten ultrasonic fusion portion 50 filling the insertion groove 402 can be prevented from being discharged to the outside of the case.

Meanwhile, the insertion protrusion 411 may protrude higher from the upper surface of the lower side wall portion 310. Accordingly, the insertion protrusion 411 is inserted into the insertion groove 402, and the upper surface of the lower side wall portion 310 and the lower surface of the upper side wall portion 210 can be in close contact. Here, the lower surface (lowest surface) of the upper side wall portion 210 may be located lower than the upper surface (uppermost surface) of the insertion protrusion 411. As a result, when the melted ultrasonic fusion portion 50 fills the gap between the upper side wall 210 and the insertion protrusion 411, the bonding force is increased, and the ultrasonic fusion portion 50 melted from the inside to the outside of the case. can be prevented from being released.

Additionally, the lower surface (lowest lower surface) of the upper engaging protrusion 401 may be disposed between the upper and lower surfaces of the insertion protrusion 411. That is, the upper engaging protrusion 401 may be arranged to be spaced apart from the lower case 30. When both the upper coupling protrusion 401 and the upper side wall 210 are supported by the lower case 30, when the cases 20 and 30 are bent, stress is excessively concentrated throughout the case coupling portion 40. do. In the case of the present invention, the upper coupling protrusion 401 is arranged to be spaced apart from the lower case 30, so that stress concentration in the case coupling portion 40 can be reduced when the cases 20 and 30 are bent. In addition, when the molten ultrasonic fusion portion 50 fills the space between the upper engaging protrusion 401 and the insertion protrusion 411, the bonding force is increased and the molten ultrasonic fusion portion 50 is discharged to the inside of the case. This can be prevented.

Referring to FIG. 9 , in one embodiment, the first electrode 110 may be disposed on one surface of the piezoelectric element layer 100. The second electrode 120 may be disposed on the other surface of the piezoelectric element layer 100. The first electrode 110 and the second electrode 120 may be formed in a predetermined pattern on the piezoelectric element layer 100.

FIG. 10 is a bottom view of the upper case 20 shown in FIG. 4, and FIG. 11 is a top view of the lower case 30 shown in FIG. 4.

Referring to FIGS. 1 to 11 , the case coupling portion 40 extends along a predetermined trajectory from the first side (P1) to the second side (P2) in a plan view. The first side (P1) and the second side (P2) are disposed at the edge of the upper case 20 or the lower case 30 in plan view. As a result, the terminal opening O can be defined between the first side P1 and the second side P2. That is, the terminal opening O may be disposed between the upper plate 200 and the lower plate 300. The terminal 60 is pulled out to the outside of the cases 20 and 30 through the terminal opening (O). Accordingly, one side or the entire other side of the cases 20 and 30 may be arranged to be in close contact with the vibrating body (not shown). Additionally, the terminal 60 extends in a plane from the side of the vibration unit 10 and is drawn out to the outside of the cases 20 and 30. As a result, the vibrating unit 10 can be attached in close contact with the front surfaces of the cases 209 and 30, and thus easy damage due to brittleness of the piezoelectric element layer 100 can be prevented. Additionally, the upper side wall portion 210 and the lower side wall portion 310 may have a terminal opening (O). Additionally, the terminal opening O may be recessed into at least one of the upper case 20 and the lower case 30 in plan view. As a result, the degree of positional freedom of the terminal 60 can be secured.

Meanwhile, the method of manufacturing a flat piezoelectric speaker according to an embodiment of the present invention may include a step of coupling a vibrating part, a step of coupling an upper coupling part and a lower coupling part, and an ultrasonic welding step.

The vibrating unit 10 may be attached to either the upper case 20 or the lower case 30. The description of the upper case 20, lower case 30, and vibration unit 10 is the same as described above. Afterwards, the upper case 20 and the lower case 30 are matched. At this time, the upper coupling part 400 and the lower coupling part 410 are coupled. The description of the upper coupling portion 400 and the lower coupling portion 410 is the same as described above. The upper coupling portion 400 and the lower coupling portion 410 are fused by ultrasonic welding. At this time, an ultrasonic fusion portion 50 is formed between the upper coupling portion 400 and the lower coupling portion 410. The description of the ultrasonic fusion unit 50 is the same as described above.

Although the invention made by the present inventor has been described in detail according to the above-mentioned embodiments, the present invention is not limited to the above-described embodiments and, of course, can be changed in various ways without departing from the gist of the invention.

1: Piezoelectric speaker
10: Vibration unit
20: upper case
30: lower case
40: case coupling part
50: ultrasonic fusion unit
60: terminal

Claims (13)

A vibrating unit including a vibrating piezoelectric element layer;
An upper case covering the vibrating part from one direction;
A lower case covering the vibrating part from other directions;
A case coupling portion including an upper coupling portion disposed in the upper case and a lower coupling portion disposed in the lower case; and
A piezoelectric speaker that is disposed between the upper coupling portion and the lower coupling portion and includes an ultrasonic fusion portion that combines the upper coupling portion and the lower coupling portion by fusion. According to claim 1,
The upper case is disposed at the edge of the upper plate and the upper plate, and includes an upper side wall portion surrounding the upper coupling portion in plan,
A piezoelectric speaker where the lower case is disposed on a lower plate and an edge of the lower plate and includes a lower side wall portion surrounding the lower coupling portion in plan. According to claim 2,
The upper joint part,
an upper joining protrusion extending parallel to the upper side wall; and
It includes an insertion groove disposed between the upper engaging protrusion and the upper side wall portion,
The lower coupling part is a piezoelectric speaker including an insertion protrusion inserted into an insertion groove. According to claim 3,
The ultrasonic welding unit further includes a welding protrusion protruding from the upper surface of the insertion protrusion into the insertion groove,
A piezoelectric speaker whose welded protrusions are welded by ultrasonic welding to fill the insertion groove. According to claim 2,
The lower side wall portion protrudes from the lower plate toward the upper side wall portion,
The upper side wall portion protrudes from the upper plate toward the lower side wall portion,
A piezoelectric speaker in which the upper surface of the lower side wall and the lower surface of the upper side wall are in contact. According to claim 3,
The insertion protrusion is a piezoelectric speaker that protrudes higher from the upper surface of the lower side wall. According to claim 6,
The lower surface of the upper coupling protrusion is a piezoelectric speaker disposed between the upper and lower surfaces of the insertion protrusion. According to claim 1,
A piezoelectric speaker whose vibrating unit is coupled to either the upper case or the lower case. According to claim 1,
The case coupling part is disposed at the edge of the upper case in plan view, extends from the first side to the second side along the edge of the upper case, and has a terminal opening defined between the first side and the second side. According to clause 9,
A piezoelectric speaker having terminal openings in the upper and lower side walls. According to clause 9,
A piezoelectric speaker in which the terminal opening is recessed into the inside of at least one of the upper case and the lower case in plan view. According to claim 1,
The vibrating part,
Piezoelectric element layer;
A first electrode coupled to one side of the piezoelectric element layer; and
It includes a second electrode coupled to the other side of the piezoelectric element layer,
A piezoelectric speaker further comprising a terminal portion including a first terminal connected to a first electrode and a second terminal connected to a second electrode. A step of coupling a vibration unit including a piezoelectric element layer to one of the upper case and the lower case;
Combining the upper coupling portion and the lower coupling portion; and
A method of manufacturing a piezoelectric speaker comprising the step of welding the upper coupling portion and the lower coupling portion with ultrasonic waves to form an ultrasonic fusion portion that joins the upper case and the lower case.

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