CN213462319U - Piezoelectric sounding body - Google Patents

Abstract

The utility model provides a piezoelectricity sound production body. A piezoelectric sounding body (10) is provided with: a piezoelectric vibrating piece (20); a case (50) which houses the piezoelectric vibrating reed (20) therein; a lid-shaped substrate (40) which is attached to the case (50) and forms a housing space for the piezoelectric vibrating reed (20) together with the case (50); and conductive terminals (60, 70) electrically connected to the piezoelectric vibrating reed (20). The conductive terminals (60, 70) have tip portions (62, 72) that elastically press the piezoelectric vibrating reed (20) toward the case side, and terminal bodies (68, 78) that are connected to the tip portions (62, 72). At least a part of the terminal main body (68, 78) is embedded in the lid-like substrate (40) and fixed. According to the utility model discloses, can make the piezoelectric vibrating reed in the piezoelectric sound production body vibrate fully.

Description

Piezoelectric sounding body

Technical Field

The present invention relates to a piezoelectric sounding body for generating sound by vibration of a piezoelectric vibrating piece.

Background

The piezoelectric sounding body generates sound by applying an electric signal to a piezoelectric vibrating reed housed in a case to vibrate the piezoelectric vibrating reed. In patent document 1, a terminal for applying an electric signal to a piezoelectric vibrating reed is fixed to a case, and the periphery of the piezoelectric vibrating reed is adhesively fixed to the case using a silicone adhesive or the like.

However, in the structure in which the terminal is fixed to the case and the periphery of the piezoelectric vibrating reed is bonded to the case using a silicone adhesive or the like, there is a problem that vibration of the piezoelectric vibrating reed is excessively restricted and sound pressure or sound quality may be reduced. In addition, the work for bonding the periphery of the piezoelectric vibrating reed is also complicated.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2003-23697.

SUMMERY OF THE UTILITY MODEL

Problem to be solved by the utility model

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a piezoelectric sounding body which can be expected to improve sound pressure and/or sound quality and can be easily manufactured.

Means for solving the problems

In order to achieve the above object, the piezoelectric sounding body of the present invention has:

a piezoelectric vibrating piece;

a case that houses the piezoelectric vibrating reed therein;

a lid-like substrate attached to the case and forming a housing space for the piezoelectric vibrating reed together with the case; and

a conductive terminal electrically connected to the piezoelectric vibrating piece,

the conductive terminal has: a tip portion that elastically presses the piezoelectric vibrating reed toward the case; and a terminal main body connected to the front end portion,

at least a part of the terminal main body is embedded in the cover substrate and fixed.

In the piezoelectric sounding body of the present invention, the piezoelectric vibrating piece is elastically pressed by the tip portion of the conductive terminal partially embedded in the lid-like substrate. When the piezoelectric sounding body is mounted on a circuit board or the like, the mounting-side outer surface of the lid substrate is positioned on the lower side in the vertical direction. As a result, the piezoelectric vibrating reed is elastically held on the case side by the distal end portion of the conductive terminal in the housing space. Therefore, the piezoelectric vibrating reed can be housed in the case only by mounting the lid substrate to the case without using an adhesive or the like, and the piezoelectric sounding body can be significantly easily manufactured.

In addition, in the piezoelectric sounding body of the present invention, since the periphery of the piezoelectric vibrating reed is not fixed with an adhesive or the like, when an electric signal (for example, a periodic voltage signal) is applied to the piezoelectric vibrating reed, the piezoelectric vibrating reed can freely vibrate without being restricted by the adhesive or the like, and the sound pressure and/or the sound quality are improved.

In addition, since a part of the terminal body of the conductive terminal is embedded in the cover substrate, the conductive terminal is not shaken and can be stably fixed to the cover substrate. In addition, resistance to impact from the outside is enhanced, so that durability of the product is also improved.

Preferably, the tip portion has an inclined portion extending from the terminal main body to an outer edge of the lid substrate and inclined toward the piezoelectric vibrating reed. The tip portion can elastically press and hold the piezoelectric vibrating reed toward the case side with a fixed force by the inclined portion inclined toward the piezoelectric vibrating reed. As a result, the electric signal can be stably supplied from the conductive terminal to the piezoelectric vibrating reed, and the piezoelectric vibrating reed can be elastically held in the case even if the piezoelectric vibrating reed vibrates in the case.

Preferably, the cover substrate has a through hole communicating with the housing space from the outside of the cover substrate, and the tip portion extends from the cover substrate and is disposed inside the through hole. By disposing the tip portion inside the through hole, the tip portion can be easily bent toward the housing side through the through hole after the conductive terminal and the cover substrate are integrally molded. In addition, after the lid substrate is mounted on the case, whether or not the tip portion and the piezoelectric vibrating reed are connected well can be easily confirmed through the through hole.

Preferably, the lid base has a groove portion extending from the through hole to an outer edge of the lid base, and communicating an inside of the through hole with an outside of the case. The piezoelectric sound generator of the present invention may be surface-mounted on a circuit board or the like so that the outer surface of the cover-like substrate faces the surface of the circuit board or the like. In this case, the through hole of the cover substrate is covered with the surface of the circuit board or the like. However, since the through hole is communicated from the outer surface of the side wall of the case to the outside through the groove, the groove and the through hole serve as an exhaust port of the housing space in the case, contributing to improvement in sound pressure and/or sound quality of sound generated by vibration of the piezoelectric vibrating reed.

Preferably, the through-hole is formed by at least a pair of through-holes, and the through-holes communicate with each other inside the housing space. The through hole functioning as the air outlet communicates with the inside of the housing space, thereby contributing to improvement in sound pressure and/or sound quality of sound generated by vibration of the piezoelectric vibrating reed. Further, since the through holes are communicated from the outer surface of the side wall of the case to the outside through the grooves, the piezoelectric sounding body can be easily surface-mounted.

The position of the sound emission hole communicating from the housing space to the outside of the case is not particularly limited, but is preferably formed on the outer wall side surface of the case. Through form the sound hole at the outer wall side of casing, need not set up the sound hole at the outer wall upper surface of casing. Therefore, the piezoelectric sounding body can be easily picked up and can be easily mounted on a printed circuit board or the like by sucking the upper surface of the outer wall of the housing by the suction nozzle. In addition, after the piezoelectric sounding body is mounted, even if an obstacle exists above the upper surface of the outer wall of the casing, a large sound pressure can be obtained. Further, by forming the sound emission hole in the outer wall side surface of the case, when the piezoelectric sound generator is surface-mounted on a circuit board or the like, it is possible to make it difficult for dust or the like to enter the inside of the case, and deterioration of sound is small.

Preferably, the distal end portion extends toward the outer wall side surface on the opposite side to the outer wall side surface of the case in which the sound emission hole is formed. Preferably, an outer wall side surface of the groove portion formed from the through hole serving as the exhaust port and an outer wall side surface of the sound emission hole are opposite to each other. With such a configuration, the sound pressure and/or sound quality of the sound generated by the vibration of the piezoelectric vibrating reed can be improved.

Preferably, the terminal main body has:

an inner portion connected to the tip portion and substantially parallel to the piezoelectric vibrating reed;

an outer portion that is substantially parallel to the inner portion and is disposed so as to be located at a different height difference portion from the inner portion; and

an intermediate portion between the inner portion and the outer portion.

With the structure having such a terminal main body, the cover-like substrate can be easily integrally molded together with the conductive terminal by, for example, insert molding.

The intermediate portions may be connected to the inner portion and the outer portion in a stepped manner, but are preferably connected to each other in an inclined manner. By inclining the intermediate portion, the inner portion of the terminal main body is easily embedded in the central portion in the thickness direction of the lid-like substrate, and the outer portion of the terminal main body is easily exposed on the same plane as the outer surface of the lid-like substrate. In addition, only the outer side portion is exposed to the outside of the cover substrate, and connection to a land of a circuit board or the like is facilitated, and surface mounting is facilitated.

Preferably, the inner portion and the intermediate portion are embedded in the lid substrate, and a portion of the outer portion near the intermediate portion may be embedded in the lid substrate, but preferably, an outer surface of the outer portion is exposed to the outside of the lid substrate. In this case, connection to a land or the like of the circuit board can be facilitated, and surface mounting can be facilitated.

Preferably, the inner side portion has a reinforcing portion for reinforcing fixation to the lid substrate. The reinforcing portion is preferably a hole portion, but may be a concave-convex portion. By providing the reinforcement portion in the inner portion, when the inner portion and the inside of the cover substrate are integrally molded by insert molding or the like, the bonding strength between the terminal body and the cover substrate can be improved.

Preferably, the inner portion has a thermal conduction reducing portion that reduces thermal conduction to the front end portion. The heat conduction reducing portion is not particularly limited, and for example, a notch or the like may be provided in the vicinity of the boundary between the inner portion and the distal end portion, and a bypass or the like may be provided in the path through which heat is transferred from the outer portion to the distal end portion. By providing the heat conduction reducing portion on the inner side portion, heat generated on the outer side portion during mounting or the like is less likely to be transmitted to the tip end portion. The front end portion maintains elasticity (spring characteristics), and it is important that the front end portion presses the piezoelectric vibrating reed toward the case side with a substantially constant force. In order not to change the spring characteristic at the tip end portion, it is preferable not to transmit high heat to the tip end portion.

Preferably, the conductive terminal has a holding portion connected to an outer portion of the terminal body so as to protrude from the cover substrate at a position different from the tip portion, and the holding portion is engaged with the housing. By engaging the holding portion with the housing, the workability of mounting the cover substrate to the housing can be improved.

Preferably, the holding part has a bending piece bent toward the case, and a bending direction of the bending piece substantially coincides with a direction in which the tip end portion of the conductive terminal elastically presses the piezoelectric vibrating reed. When the piezoelectric sound generator of the present invention is surface-mounted on, for example, a circuit board, the cover-shaped substrate may be disposed so that the outer surface of the cover-shaped substrate faces the surface of the circuit board. Therefore, solder fillets are formed on the outer surfaces of the bending pieces bent toward the case and the land portions of the circuit board, and the connection can be easily confirmed. In addition, since the stepped portion of the case suppresses the piezoelectric vibrating reed and is connected by the elastic pressure of the tip portion of the conductive terminal having elasticity, the tip portion of the conductive terminal and the electrode of the piezoelectric vibrating reed can be reliably connected.

Preferably, the cover-like substrate has at least one engaging projection at an outer periphery thereof for engaging with the housing, and the housing has at least one engaging recess corresponding to a shape of the engaging projection. With this configuration, the lid-like substrate can be easily positioned and joined to the housing.

Preferably, the cover substrate has a plurality of peripheral corner portions, and the engagement convex portion protruding outward on the same plane as the cover substrate is formed at least one peripheral corner portion. Preferably, the lid substrate has engaging projections formed at 4 outer peripheral corners thereof.

Preferably, the bottom surface and the side surface of the engaging recessed portion and the engaging protruding portion are welded together. By abutting the heating jig from the outer surface of the cover-like substrate to the vicinity of the boundary of the engaging convex portion and the engaging concave portion, the engaging concave portion and the engaging convex portion can be easily heat-welded.

Preferably, the piezoelectric vibrating reed is disposed in the housing space so as to divide the housing space into a first space and a second space, the first space has a larger volume than the second space, and the tip end portion of the conductive terminal is disposed in the second space. The first space is a main echo space of sound generated by vibration of the piezoelectric vibrating reed, and sound of a predetermined frequency is emitted from the sound emission hole. The second space is a sub-echo space of sound generated by vibration of the piezoelectric vibrating reed. The tip end of the conductive terminal is disposed in the second space.

Preferably, the piezoelectric vibrating reed is placed on a step portion formed on an inner wall surface of the case, and the housing space is divided into a first space and a second space. With this configuration, the opening of the case is directed upward when the piezoelectric resonator element is mounted, and the piezoelectric resonator element can be easily mounted on the case. Further, by forming a space above and below the piezoelectric vibrating reed, the piezoelectric vibrating reed can be sufficiently vibrated, and desired sound can be easily generated.

Preferably, the lid substrate has a stopper protrusion for restricting movement of the piezoelectric vibrating reed toward the conductive terminal. The stopper projection may be formed on the inner surface of the lid substrate so as to correspond to the shape of the outer periphery of the piezoelectric vibrating reed. When surface mounting is performed on a circuit board or the like, the piezoelectric sounding body is mounted on the circuit board or the like with the lid-like substrate facing downward, but the piezoelectric vibrating reed is displaced toward the conductive terminal due to its own weight or an external impact, and the stopper projection can prevent the piezoelectric vibrating reed from being excessively displaced toward the conductive terminal, and can improve impact resistance. Further, since the stopper projection is provided, the distal end portion is not excessively deformed, and the elasticity of the distal end portion is easily maintained.

The tip portion may have a substantially hemispherical contact protrusion, and the contact protrusion may be in contact with the piezoelectric vibrating reed. The contact protrusion can be reliably brought into contact with the piezoelectric vibrating reed, and contact failure and the like can be effectively prevented. The piezoelectric vibrating piece may be a disk shape.

Drawings

Fig. 1A is a schematic perspective view of a piezoelectric sounding body according to an embodiment of the present invention.

Fig. 1B is a schematic perspective view of the piezoelectric sounding body of fig. 1 turned upside down.

Fig. 2A is an exploded perspective view of the piezoelectric sounding body shown in fig. 1A.

Fig. 2B is an exploded perspective view of the piezoelectric sounding body shown in fig. 1B.

Fig. 3 is a perspective view showing a case portion of the piezoelectric sounding body shown in fig. 2B.

Fig. 4 is a sectional view taken along line IV-IV of the lid substrate of the piezoelectric sounding body shown in fig. 2B.

Fig. 5A is a sectional view taken along a VA-VA line of the case and the piezoelectric vibrating piece of the piezoelectric sounding body shown in fig. 2B.

Fig. 5B is a cross-sectional view taken along line VB-VB of the case of the piezoelectric sounding body and the piezoelectric vibrating piece shown in fig. 2B.

Fig. 5C is an enlarged cross-sectional view of the piezoelectric vibrating piece of the piezoelectric sounding body shown in fig. 2B.

Description of the symbols

10 … piezoelectric sounding body

20 … piezoelectric vibrating reed

22 … piezoelectric element

22a … first electrode

22b … second electrode

23 … adhesive

24 … vibrating reed

40 … lidding substrate

41a … installation side outer surface

41b … inner surface

41c … outer edge

42 … sound emitting hole

43a, 43b … through hole

46 … engagement tab

47a, 47b … groove part

48 … playback side projection

49 … stop tab

50 … casing

51 … housing step

51a … stepped portion peripheral wall

52 … bottom surface

52a … inner side wall surface

53 … side of outer wall of shell

53a … first recess

53b … second recess

54a … mounting opposite side exterior surface

54b … mounting side outer surface

55 … accommodating space

55a … first space

55b … second space

56 … engagement recess

59a … communication notch

59b … playback side cutout

60. 70 … conductive terminal

62. 72 … front end

62a, 72a … terminal inclined portion

62b, 72b … abut the projection

64. 74 … holding part

68. 78 … terminal body

68a, 78a … inner side

68b, 78b … intermediate portion

68c, 78c … outer side

68d, 78d … reinforcing holes (reinforcing parts)

68e, 78e … thermal conductivity relief

Detailed Description

The present invention will be described below based on embodiments shown in the drawings. Further, in the drawings. The X-axis, the Y-axis and the Z-axis are perpendicular to each other, and the side opposite to the direction of the arrow of the Z-axis is the mounting surface side.

As shown in fig. 1A and 1B, a piezoelectric sounding body 10 according to an embodiment of the present invention includes a piezoelectric vibrating piece 20, a lid-shaped substrate 40, and a case 50. First, the piezoelectric vibrating reed 20 will be explained.

(piezoelectric vibrating piece)

As shown in fig. 2A and 2B, the piezoelectric vibrating piece 20 has a vibrating piece 24 of a flat plate shape. A flat piezoelectric element 22 having an outer diameter smaller than that of the vibrating reed 24 is fixed to one surface of the vibrating reed 24 along the Z axis. As shown in fig. 5C, a first electrode 22a and a second electrode 22b are formed on the front surface and the back surface of the piezoelectric element 22, respectively. As shown in fig. 2B, the first electrode 22a has an outer diameter slightly smaller than the outer diameter of the piezoelectric element 22, and is formed in a film shape so as to cover the center portion of the surface of the piezoelectric element 22. Although not visible in fig. 2B, a second electrode 22B shown in fig. 5C is formed on the back surface of the piezoelectric element 22 in the same manner as the first electrode 22 a.

As shown in fig. 5C, the back surface of the piezoelectric element 22 is bonded and fixed to the surface of the vibrating reed 24 by, for example, an adhesive 23. The adhesive 23 may enter between the second electrode 22b and the piezoelectric element 24, and the second electrode 22b and the vibrating reed 24 may be electrically connected without any problem. The adhesive 23 may be a conductive adhesive. The piezoelectric vibrating reed 20 may be formed by laminating and forming the second electrode 22b, the piezoelectric element 22, and the first electrode 22a on the vibrating reed 24 in this order by a thin film method or the like without using the adhesive 23.

The second electrode 22b is not necessarily provided on the piezoelectric element 22, and the back surface of the piezoelectric element 22 may be electrically connected to the vibrating reed 24 directly or indirectly. The vibrating reed 24 may be connected to the back surface of the piezoelectric element 22 via the second electrode 22b, or may not be connected to the back surface of the piezoelectric element 22 via the second electrode 22b, and in either case, the vibrating reed 24 functions as an electrode on the other side of the piezoelectric element 22 which is paired with the first electrode 22 a.

The vibrating reed 24 is insulated from the first electrode 22a, and a voltage as an electric signal is applied to the piezoelectric element 22 via the vibrating reed 24 and the first electrode 22a, whereby the piezoelectric element 22 vibrates telescopically at a predetermined frequency. The vibrating reed 20 vibrates in the Z-axis direction and generates sound in accordance with the expansion and contraction vibration of the piezoelectric element 22.

The material of the piezoelectric element 22 is not particularly limited as long as it is a piezoelectric material, but it is composed of, for example, ferroelectric ceramics such as PZT (lead zirconate titanate) and PT (lead titanate), or crystal. The material of the vibrating piece 24 is not particularly limited, and for example, a metal material such as brass, Ni alloy, and stainless steel can be used. The first electrode 22a and the second electrode 22b are made of, for example, a sintered electrode film of Ag paste, but are not limited thereto.

The shapes of the vibrating reed 24 and the piezoelectric element 22 are not particularly limited, but generally have a concentric structure on the XY plane. The piezoelectric element 22 is located at a substantially central portion of the vibrating reed 24 on the XY plane. The outer diameter of the vibrating piece 24 is not particularly limited, but is usually about 6 to 20 mm. The thickness (thickness in the Z direction) of the vibrating piece 24 is not particularly limited, but is usually about 30 to 150 μm. The outer diameter of the piezoelectric element 22 is not particularly limited, but is usually about 4 to 18 mm. The thickness (thickness in the Z direction) of the piezoelectric element 22 is not particularly limited, but is usually about 30 to 150 μm. The thickness (thickness in the Z direction) of the electrodes 22a, 22b is not particularly limited, but is usually about 5 to 15 μm.

(case and lid-shaped substrate)

Next, the case 50 and the lid substrate 40 will be explained. First, the case 50 will be explained. As shown in fig. 3, the case 50 has a substantially rectangular box shape with a prescribed height H. As shown in fig. 5B, the non-mounting side outer surface 54a of the housing 50 has a substantially flat outer surface without a large groove, a recess, or the like. Further, although some grooves, projections, and depressions may be formed on the non-mounting side outer surface 54a, it is preferable that a through hole penetrating the front surface and the back surface is not formed.

The height H0 of the case 50 is approximately equal to the thickness of the piezoelectric sounding body 10 shown in fig. 1A, and is preferably about 2.8 to 3.0 mm. The X-axis length and the Y-axis length of the case 50 shown in fig. 3 are also approximately the same as those of the piezoelectric sounding body 10 shown in fig. 1A, and are preferably about 11.8 to 12.2 mm.

As shown in fig. 3, a substantially cylindrical housing space 55 is formed in the center portion of the X-Y plane of the mounting-side outer surface 54b of the housing 50. As shown in fig. 5B, the depth H1 from the mounting-side outer surface 54B to the bottom surface 52 of the housing space 55 is smaller than the height H0 of the case 50, and is determined to be able to sufficiently secure the thickness of the case 50 from the bottom surface 52 to the non-mounting-side outer surface 54a of the case 50 in terms of strength.

As shown in fig. 3, a case step portion 51 for placing the outer peripheral edge of the piezoelectric vibrating reed 20 shown in fig. 5A is formed along the circumferential direction of the housing space 55 on the circumferential surface-shaped inner wall surface 52a of the case 50, except for a sound emission side notch 59b described later. In fig. 3 (the same applies to fig. 1B, 2B, 5A, and 5B), the non-mounting side outer surface 54a of the housing 50 is disposed so as to face vertically downward along the Z axis.

As shown in fig. 5B, the housing step 51 is located at a position higher than the bottom surface 52 by a predetermined height h0 and parallel to the bottom surface 52. The piezoelectric vibrating reed 20 is mounted on the case step portion 51 such that the vibrating reed 24 is disposed on the case step portion 51. A stepped portion peripheral wall 51a is formed around the case stepped portion 51 so as to surround the piezoelectric vibrating reed 20. By disposing the outer peripheral edge of the piezoelectric vibrating reed on the case step portion 51, the housing space 55 of the case 50 is divided into a first space 55a located near the bottom surface 52 and a second space 55b located near the mounting-side outer surface 54 b.

The predetermined height H0 of the step portion 51 is preferably larger than 1/2 of the depth H1 of the bottom surface 52 of the housing space 55, and H0/H1 is preferably 0.5 to 0.8. By setting the numerical range as described above, the volume of the first space 55a defined by the vibrating reed 20 in the housing space 55 can be made sufficiently larger than the volume of the second space 55 b. As a result, the sound pressure and/or sound quality of the piezoelectric sounding body 10 can be improved.

As shown in fig. 3, first recesses 53a, 53a are formed on both sides along the Y axis of a mounting-side outer surface 54b of the housing 50 on the opposite side of the mounting-side outer surface 54a along the Z axis. The depth of the concave portions 53a, 53a along the Z axis is preferably as thick as the outer portions 68c, 78c of the conductive terminals 60, 70 described later shown in fig. 2B. In addition, concave portions 53b and 53b corresponding to the concave portions 53a and 53a are formed on the outer wall side surface of the housing 50. The holding portions 64 and 74 of the conductive terminals 60 and 70 can be engaged with the concave portions 53b and 53 b. The depth of the concave portions 53b and 53b along the Y axis is the same as the depth of the concave portions 53a and 53a along the Z axis.

As shown in fig. 3, a communication cutout 59a and a sound-discharging-side cutout 59b are formed on both sides of the mounting-side outer surface 54b of the housing 50 along the X axis, respectively. The width of the communicating slit 59a along the Y axis is such a width as to communicate the pair of groove portions 47a and 47B formed on the mounting-side outer surface 41a of the lid-like substrate 40 shown in fig. 2B. The depth of the communicating notch 59a along the Z axis is substantially the same as the depth of the pair of grooves 47a and 47B along the Z axis, and the bottom surface of the communicating notch 59a and the bottom surfaces of the grooves 47a and 47B are flush with each other in the assembled state (see fig. 1B).

As shown in fig. 5B, the bottom surface of the sound emission side cutout 59B is located lower than the case step 51 by a predetermined height h1 along the Z axis. Therefore, in the present embodiment, the sound emission hole 42 mainly communicating with the first space 55a of the housing space 55 from the outside of the casing 50 is formed in the side of the piezoelectric sounding body 10, specifically, in the center portion of the casing outer wall side surface 53 in the Y axis direction along the X axis. The height h1 of the sound emitting hole 42 communicating with the first space 55a is preferably smaller than the height h0 of the step portion, but may be h 0-h 1 depending on the content of the generated sound.

As shown in fig. 1B, the sound emission hole 42 is formed by fitting the sound emission side projection 48 of the lid-like substrate 40 into the sound emission side cutout 59B of the case 50. The width of the sound emission side cutout 59B in the Y axis direction is preferably slightly larger than the width of the sound emission side projection 48 in the Y axis direction, and is determined by the content of the sound to be generated by the piezoelectric sounding body 10 together with the height h3 of the sound emission hole 42 shown in fig. 5B.

The content of the sound refers to the sound pressure, quality, and the like of the sound, and includes the level of the sound, the frequency of the sound, and the like. The sound emission hole 42 includes, as a factor for determining the content of sound, an X-axis direction width w1 from the case outer wall side surface 53 to the stepped portion outer peripheral wall 51a, an X-axis direction width w2 of the case stepped portion 51, and the like.

As shown in fig. 5B, the height h3 of the sound emission hole can be defined as the height from the bottom surface of the cutout 59B in the Z-axis direction to the bottom surface of the engagement recess 56 in the Z-axis direction. The height h3 of the sound emission hole can be defined as the height h1 of the sound emission hole 42 that communicates with the first space 55a plus the height h2 of the sound emission hole 42 that communicates with the second space 55 b.

As shown in fig. 2B, the engagement recess 56 is formed in 4 corners facing the mounting side outer surface 54B of the housing 50 in the present embodiment, and expands convexly outward from the stepped outer peripheral wall 51 a. The depth of the bottom surface of each bonding recess 56 along the Z axis is preferably equal to the thickness of the lid substrate 40 (along the Z axis), that is, the thickness of the bonding projections 46 formed at the 4 corners of the lid substrate 40 (along the Z axis), but may be slightly smaller or larger than the thickness of the bonding projections 46.

However, the depth of the bottom surface of each bonding recess 56 along the Z axis is determined so that the inner surface 41B of the lid substrate 40 shown in fig. 4 does not contact the electrode 22a of the piezoelectric element 22 shown in fig. 2B. The stopper projection 49 projecting from the outer peripheral edge of the inner surface 41B of the lid-like substrate 40 shown in fig. 4 in the Z-axis direction toward the opposite side may be in contact with the vibrating reed 24 in order to restrict the movement of the piezoelectric vibrating reed 20 shown in fig. 2B in the Z-axis direction.

Further, the depth of the bottom surface of each engagement recess 56 along the Z axis is determined to be a height h2 that can secure the sound emission hole 42 that can communicate with the second space 55B shown in fig. 5B. The height h2 of the sound emission hole 42 communicable with the second space 55b is coincident with the height in the Z-axis direction of the second space 55b corresponding to the gap between the piezoelectric vibrating piece 20 and the inner surface 41b of the lid substrate 40 shown in fig. 4.

In the present embodiment, the case 50 is made of a thermoplastic resin such as a liquid crystal polymer resin, a polybutylene terephthalate resin, a polyphenylene sulfide resin, a polyether ether ketone resin, or a fluororesin.

The lid substrate 40 described later may be made of the same material as the case 50 or a different material. In the present embodiment, since the cover substrate 40 is insert-molded with the conductive terminals 60, 70 such as the metal terminals, the cover substrate 40 is preferably made of a thermoplastic resin which is easily insert-molded.

Next, the lid substrate 40 will be mainly explained. As shown in fig. 2B, the cover substrate 40 is formed of a substantially rectangular flat plate-like substrate having a thickness substantially equal to the depth of the joining recess 56 formed in the case 50. The 4 corners of the substrate 40 are formed integrally with the substrate 40 with the engagement convex portions 46 having a planar shape corresponding to the planar shape of the engagement concave portions 56 (the plane parallel to the X-Y axis plane).

Further, a sound emission side projection 48 is formed on the outer edge of the lid-like substrate 40 so as to project along the X axis at a position corresponding to the sound emission side notch 59b formed in the housing 50. As described above, the sound emission side projection 48 is fitted into the opening entrance of the sound emission side cutout 59b, and forms the sound emission hole 42 together with the sound emission side cutout 59 b.

The mounting-side outer surface 41a of the cover substrate 40 includes a flat surface in which both the engaging projection 46 and the sound-discharging-side projection 48 are flat. However, through holes 43a and 43b are formed in the mounting-side outer surface 41a on the opposite side of the sound emission-side projection 48 along the X axis, with positions thereof shifted from each other along the X axis and the Y axis. The through holes 43a, 43b communicate from the mounting-side outer surface 41a to the inner surface 41 b. Groove portions 47a, 47b extending along the X axis from the through holes 43a, 43b to the outer edge 41c of the lid substrate are formed on the mounting-side outer surface 41 a.

The one through hole 43a and the one groove 47a have the same width in the Y axis direction and are linearly arranged along the X axis. The through hole 43a communicates with the inner surface 41b from the mounting-side outer surface 41a, but the groove portion 47a is a stepped portion recessed from the mounting-side outer surface 41a by a predetermined depth along the Z axis, and does not penetrate the front surface and the back surface. Similarly, the other through hole 43b and the other groove 47b have the same width in the Y axis direction and are linearly arranged along the X axis. The through hole 43b communicates from the mounting-side outer surface 41a to the inner surface 41b, but the groove portion 47b is a stepped portion recessed from the mounting-side outer surface 41a by a predetermined depth along the Z axis, and does not penetrate the front surface and the back surface.

The through holes 43a and 43b have substantially the same width in the Y axis direction, and preferably have substantially the same opening area. The one through hole 43a is located closer to the center of the substrate 40 along the X axis than the through hole 43b, and the tip 62 of the conductive terminal 60 disposed inside the through hole 43a is in contact with and electrically connected to the first electrode 22a of the piezoelectric vibrating reed 20. The other through hole 43b is located closer to the outer edge 41c of the substrate 40 along the X axis than the through hole 43a, and the tip 72 of the conductive terminal 70 disposed inside the through hole 43b is in contact with and electrically connected to the vibrating reed 24 of the piezoelectric vibrating reed 20.

The sound emission side projection 48 is provided at a position between the through holes 43a and 43b along the Y axis. The groove depths of the grooves 47a and 47b are preferably the same, but may be different. Further, since the through holes 43a and 43b are different in position along the X axis, the length of each groove portion 47a and 47b along the X axis is naturally different.

These grooves 43a and 43b are preferably provided, but at least one (or both) may not be provided. At least one (or both) of the grooves 43a and 43b may be a through hole continuous with the corresponding through hole 43a or 43 b. As described above, these groove portions 43a and 43b are connected to the communication slit 59a formed in the housing 50.

As shown in fig. 2A and 4, an annular stopper projection 49 projecting along the Z axis is formed on the inner surface 41b near the outer periphery of the lid-like substrate 40. The stopper projection 49 preferably has a rounded tip along the Z axis, and a narrow tip, and can be brought into contact with a surface close to the outer peripheral edge of the piezoelectric vibrating reed 20 in an assembled state.

As shown in fig. 4, a part of the conductive terminals 60, 70 is embedded in the lid substrate 40. The conductive terminals 60 and 70 are made of a conductive material, such as stainless steel, phosphor bronze, or Ni alloy. In particular, a plating film may be formed on the surface of the conductive terminals 60 and 70 at the exposed portion of the substrate 40 in order to improve the bonding property with solder or the like. The plating film is composed of, for example, Ni, Cu, Cr, etc. as a base metal, and Sn, Au, Cu, etc. as a surface metal. Of course, a plating film may be formed on the surface of the conductive terminals 60 and 70 embedded in the sheet.

Each of the conductive terminals 60 and 70 has a terminal body 68 and 78, a tip portion 62 and 72, and a holding portion 64 and 74, respectively, and is formed by bending and molding a continuous conductive sheet. Each of the terminal main bodies 68 and 78 has inner portions 68a and 78a, intermediate portions 68b and 78b, and outer portions 68c and 78c, which are continuous with each other, and the inner portions 68a and 78a and the outer portions 68c and 78c are arranged parallel to the X-Y axis plane and at different height differences.

The intermediate portions 68c, 78c are inclined relative to the respective inner and outer portions 68a, 78a, 68c, 78c, with the outer ends of the inner and outer portions 68a, 78a, 68c, 78c being connected by the intermediate portions 68b, 78 b. The inner portions 68a, 78a are embedded in the center portion of the cover substrate 40 in the thickness direction, the intermediate portions 68b, 78b are embedded in the cover substrate 40 obliquely, and the conductive terminals 60, 70 are stably fixed to the cover substrate 40, respectively. In addition, the outer surfaces of the outer portions 68c, 78c are located on the same plane as the mounting-side outer surface 41 a.

As shown in fig. 2A and 2B, reinforcement holes 68d, 78d are formed in the inner side portions 68a, 78 a. Further, the inner portions 68a, 78a have cutout portions formed near the boundaries between the inner portions 68a, 78a and the distal end portions 62, 72. Since the width of the inner portions 68a, 78a along the X axis is narrowed by the cutout portions, the passage of the heat transfer path is narrowed, and the heat transfer reducing portions 68e, 78e are formed on the inner portions 68a, 78 a.

The outer portions 68c, 78c protrude outward from the edge of the base sheet 40 along the Y axis, and holding portions 64, 74 bent along the Z axis toward the case 50 are formed further outward than the outer portions 68c, 78 c. A gap is formed between the holding portions 64 and 74 and the outer peripheral surface of the substrate 40, and a stepped portion outer peripheral wall 51a corresponding to the first recess 53a and the second recess 53B formed in the housing 50 shown in fig. 2B is inserted into the gap. As a result, the holding portions 64 and 74 engage with the second recess 53b of the housing 50, respectively.

Near the inner ends of the inner portions 68a, 78a along the Y axis, the respective leading end portions 62, 72 are integrally connected so as to project from the substrate 40 toward the outer side along the X axis (the respective through holes 43a, 43 b). The distal end portions 62 and 72 extend from inner side surfaces of the through holes 43a and 43b substantially perpendicular to the X axis toward the outer edge 41c of the base sheet 40 in which the groove portions 47a and 47b are formed.

The distal end portions 62 and 72 have terminal inclined portions 62a and 72a inclined from inner side surfaces of the through holes 43a and 43b substantially perpendicular to the X axis toward the piezoelectric vibrating reed 20, respectively. The terminal inclined portions 62a, 72a can be formed by bending the distal end portions 62, 72 in the through holes 43a, 43b in the direction in which the piezoelectric vibrating reed 20 is disposed after the conductive terminals 60, 70 and the substrate 40 are insert-molded. The contact protrusions 62b and 72b protruding in the direction of the piezoelectric vibrating reed 20 may be formed in a substantially hemispherical shape at the tips of the tips 62 and 72.

As shown in fig. 4, the tip of one tip portion 72 is preferably curved and inclined more strongly in a direction away from the inner surface 41b than the tip of the other tip portion 62. This is for elastically pressing and contacting the one tip portion 72 against the surface of the vibrating reed 24 of the piezoelectric vibrating reed 20 shown in fig. 5C, and for elastically pressing and contacting the other tip portion 62 against the surface of the first electrode 22a of the piezoelectric vibrating reed 20. Thus, the distal end portions 62 and 72 are electrically connected to the piezoelectric vibrating reed 20.

(production method)

The lid substrate 40, the case 50, and the piezoelectric vibrating piece 20 are assembled as follows, for example. As shown in fig. 5A, when the non-mounting side outer surface 54a of the case 50 faces the vertical lower side (the direction of the arrow of the Z axis) and the opening of the housing space 55 of the case 50 faces the upper side (the direction opposite to the arrow of the Z axis), the piezoelectric vibrating reed 20 is mounted inside the case 50. Specifically, as shown in fig. 2B, first, the piezoelectric vibrating reed 20 is placed on the case step portion 51 so that the piezoelectric element 22 faces upward.

Next, as shown in fig. 1B, the substrate 40 is mounted on the housing 50. At this time, the sound emission side projection 48 is fitted to the upper portion of the sound emission side cutout 59b, and the engagement projections 46 are fitted to the engagement recesses. At this time, when the holding portions 64 and 74 of the conductive terminals 60 and 70 are bent in advance along the Z axis, the holding portions 64 and 74 engage with the second concave portion 53b of the housing 50 simultaneously with the mounting of the substrate 40 to the housing 50 by the holding portions 64 and 74.

In a state before the substrate 40 is mounted to the housing 50, the holding portions 64 and 74 of the conductive terminals 60 and 70 may not be bent along the Z axis in advance, and after the substrate 40 is mounted to the housing 50, the holding portions 64 and 74 of the conductive terminals 60 and 70 may be bent substantially perpendicular to the horizontal outer portions 68c and 78c along the Z axis and engaged with the second concave portion 53b of the housing 50 by caulking.

At this time, the lid substrate 40 is pressed toward the case 50 so that the tip of the tip portion 72 contacts the vibrating reed 24 of the piezoelectric vibrating reed 20 and the tip of the tip portion 62 contacts the first electrode 22 a. Thus, even if the piezoelectric vibrating reed 20 is not fixed to the case 50 with an adhesive or the like, the piezoelectric vibrating reed can be elastically pressed toward the case 50 by the front end portions 62 and 72 of the conductive terminals 60 and 70, and can be sandwiched and held between the case 50 and the front end portions 62 and 72. Further, whether or not the distal end portions 62 and 72 are in contact with the correct positions can be confirmed from the through holes 43a and 43 b.

Therefore, the joining concave portion 56 and the joining convex portion 46 partially in contact therewith are welded and fixed together by ultrasonic waves or the like in a state where the lid-shaped substrate 40 and the case 50 are accurately held, thereby manufacturing the piezoelectric sounding body 10.

(summary of the embodiment)

As shown in fig. 1B, in the piezoelectric sounding body 10 of the present embodiment, the piezoelectric vibrating reed 20 is electrically connected to the tip portions 62 and 72 by the tip portions 62 and 72 of the conductive terminals 60 and 70 which are partially embedded in the lid-shaped substrate 40 and integrally molded being elastically pressed toward the case 50. When the piezoelectric sounding body 10 is mounted on a circuit board or the like, as shown in fig. 1A, the mounting-side outer surface 41A of the lid substrate 40 is positioned on the lower side in the vertical direction.

As a result, the piezoelectric vibrating reed 20 is elastically held by the distal end portions 62 and 72 of the conductive terminals 60 and 70 in the housing space 55 (see fig. 3 and 5A) formed in the case 50 to which the lid substrate 40 is attached. Therefore, the piezoelectric vibrating reed 20 can be housed in the case 50 only by mounting the lid substrate 40 to the case 50 without using an adhesive or the like, and the piezoelectric sounding body 10 can be manufactured significantly easily.

In the piezoelectric sounding body 10 of the present embodiment, since the periphery of the piezoelectric vibrating reed 20 is not fixed with an adhesive or the like, when a periodic voltage signal is applied to the piezoelectric vibrating reed 20 from the conductive terminals 60 and 70, the piezoelectric vibrating reed 20 can freely vibrate without being restricted by the adhesive or the like, and the sound pressure and/or sound quality can be improved.

Further, since a part of the terminal body of the conductive terminal 60, 70 is embedded in the lid-like substrate 40, the conductive terminal 60, 70 can be stably fixed to the lid-like substrate 40 without rattling. In addition, the resistance to external impact is increased, and the durability of the product as the piezoelectric sounding body 10 is also improved.

As shown in fig. 1B, the tip portions 62 and 72 have inclined portions 62a and 72a extending from the terminal main bodies 68 and 78 toward the outer edge of the lid substrate 40 and inclined toward the piezoelectric vibrating reed 20. The tip portions 62 and 72 can elastically press and hold the piezoelectric vibrating reed 20 toward the case 50 with a fixed force by the inclined portions 62a and 72a inclined toward the piezoelectric vibrating reed 20. As a result, the electric signal can be stably supplied from the conductive terminals 60 and 70 to the piezoelectric vibrating reed 20, and the piezoelectric vibrating reed 20 can be elastically held in the case 50 even if the piezoelectric vibrating reed 20 vibrates in the case 50.

The lid substrate 40 has through holes 43a and 43b communicating with the housing space 55 from the outside of the lid substrate 40, and the tip portions 62 and 72 are disposed inside the through holes 43a and 43b so as to extend from the lid substrate 20. By disposing the distal end portions 62 and 72 inside the through holes 43a and 43b, the distal end portions 62 and 72 can be easily bent in a direction away from the inner surface 41b of the substrate 40 through the through holes 43a and 43b after the conductive terminals 60 and 70 are integrally molded with the cover-like substrate 40. After the lid substrate 40 is mounted on the case 50, whether or not the distal end portions 62 and 72 are connected to the piezoelectric vibrating reed 20 can be easily confirmed by the through holes 43a and 43 b.

As shown in fig. 1B, the lid substrate 40 has groove portions 47a and 47B extending from the through holes 43a and 43B to the outer edge of the lid substrate 40 and communicating the insides of the through holes 43a and 43B with the outside of the housing 50. The piezoelectric sounding body 10 may be surface-mounted on a circuit board or the like so that the mounting-side outer surface of the cover substrate 40 faces a surface of the circuit board (not shown), for example. In this case, the through holes 43a and 43b of the cover substrate 40 are covered with the surface of the circuit board or the like. However, since the through holes 43a and 43b are communicated from the outer wall side surface 53 of the case 50 to the outside through the groove portions 47a and 47b and the notch 59a, the groove portions 47a and 47b and the through holes 43a and 43b serve as exhaust ports with respect to the housing space 55 inside the case 50, and contribute to improvement in sound pressure and/or sound quality of sound caused by vibration of the piezoelectric vibrating reed 20.

In the present embodiment, the through-hole is formed by a pair of through-holes 43a and 43B, and these through-holes 43a and 43B communicate with each other inside the second space 55B in the housing space 55 shown in fig. 5B. The through holes 43a and 43b functioning as the exhaust ports communicate with each other inside the housing space, thereby contributing to improvement in sound pressure and/or sound quality of sound generated by vibration of the piezoelectric vibrating reed. Further, since the through holes 43a and 43b are communicated from the outer wall side surface 53 of the case 50 to the outside through the groove portions 47a and 47b and the notch 59a, the piezoelectric sounding body 10 is easily surface-mounted.

In the present embodiment, the sound emission hole 42 communicating from the housing space 55 to the outside of the casing 50 may be directed outward along the Z axis, but may be directed outward along the X axis (may be directed outward along the Y axis) instead of this direction. That is, the sound emission hole 42 is formed in the outer wall side 53 of the case. By forming the sound emission holes 42 in the outer wall side surface 53 of the casing 50, it is not necessary to provide the sound emission holes 42 in the outer wall upper surface 54a of the casing 50. Therefore, by sucking the outer wall upper surface 54a of the housing 50 by the suction nozzle, the piezoelectric sounding body 10 can be easily picked up and can be easily mounted on a printed circuit board or the like. In addition, after the piezoelectric sounding body 10 is mounted, even if an obstacle exists above the outer wall upper surface 54a of the case 50, a large sound pressure can be obtained. Further, by forming the sound emission hole 42 in the outer wall side surface 53 of the case 50, when the piezoelectric sounding body 10 is surface-mounted on a circuit board or the like, it is possible to make it difficult for dust or the like to enter the inside of the case 50 through the sound emission hole 42, and deterioration of sound is reduced.

In the present embodiment, as shown in fig. 1B, the distal end portions 62 and 72 extend toward the outer wall side surface 53 located on the opposite side of the outer wall side surface 53 of the case 50 in which the sound emission hole 42 is formed. The position of the outer wall side surface 53 where the notch 59a communicating with the grooves 47a and 47b from the through holes 43a and 43b serving as the exhaust ports is formed is opposite to the position of the outer wall side surface 53 where the sound emission hole 42 is formed. With such a configuration, the sound pressure and/or sound quality of the sound generated by the vibration of the piezoelectric vibrating reed can be improved.

In the present embodiment, as shown in fig. 4, the terminal main bodies 68 and 78 include: the inner portions 68a, 78 a; outer portions 68c, 78c that are substantially parallel to the inner portions 68a, 78a and are disposed so as to be positioned at a different level difference portion from the inner portions 68a, 78 a; and intermediate portions 68b, 78b located between the inner side portions 68a, 78a and the outer side portions 68c, 78 c. With the structure of the terminal main bodies 68, 78, the cover-like substrate 40 can be easily integrally molded together with the conductive terminals 60, 70 by, for example, insert molding.

The intermediate portions 68b, 78b may be connected to the inner portions 68a, 78a and the outer portions 68c, 78c in a stepped manner, but are preferably connected to each other in an inclined manner. By inclining the intermediate portions 68b, 78b, the inner portions 68a, 78a of the terminal main bodies 68, 78 are easily buried in the central portion in the thickness direction of the cover substrate 40, and the outer portions 68c, 78c of the terminal main bodies 68, 78 are easily exposed on the same plane as the mounting-side outer surface 41a of the cover substrate 40. In addition, only the outer portions 68c, 78c of the terminal bodies 68, 78 are exposed to the outside of the cover substrate 40, and the connection with the lands of the circuit board and the like is facilitated, thereby facilitating surface mounting.

The inner portions 68a, 78a and the intermediate portions 68b, 78b are embedded in the cover substrate 40, and a part of the outer portions 68c, 78c near the intermediate portions 68b, 78b may be embedded in the cover substrate 40, but it is preferable that the outer surfaces of the outer portions 68c, 78c are exposed to the outside substantially flush with the mounting-side outer surface 41a of the cover substrate 40 (may slightly protrude from the outer surface 41a in the Z-axis direction). In this case, connection to a land or the like of the circuit board can be facilitated, and surface mounting can be facilitated.

In the present embodiment, the inner portions 68a and 78a have reinforcing holes 68d and 78d as reinforcing portions for reinforcing the fixation to the lid substrate 40 as shown in fig. 1B. By providing the reinforcement holes 68d, 78d in the inner portions 68a, 78a, when the inner portions 68a, 78a and the inside of the lid substrate 40 are integrally molded by insert molding or the like, the bonding strength between the terminal bodies 68, 78 and the lid substrate 40 can be increased.

In addition, in the present embodiment, the inner portions 68a, 78a have heat conduction reducing portions 68e, 78e that reduce heat conduction to the front end portions 62, 72. As the heat conduction reducing portions 68e and 78e, for example, a notch or the like may be provided in the vicinity of the boundary between the inner portions 68a and 78a and the distal end portions 62 and 72, and a bypass or the like may be provided in the path through which heat is transferred from the outer portions 68c and 78c to the distal end portions 62 and 72.

By providing the thermal conduction reducing portions 68e, 78e on the inner side portions 68, 78, heat generated at the outer side portions 68c, 78c is less likely to be transmitted to the distal end portions 62, 72 during mounting or the like. The elasticity (spring characteristics) is maintained at the tip portions 62 and 72, and it is important that the tip portions 62 and 72 press the piezoelectric vibrating reed 20 against the step portion 51 of the case 50 with a substantially constant force. In order not to change the spring characteristics at the distal end portions 62, 72, it is preferable not to transmit high heat to the distal end portions 62, 72.

In the present embodiment, the conductive terminals 60 and 70 have holding portions 64 and 74 that extend from the cover substrate 40 at positions different from the distal end portions 62 and 72 and are connected to the outer portions 68c and 78c of the terminal main bodies 68 and 78, and the holding portions 64 and 74 engage with the concave portions 53b and 53b of the housing 50. By engaging the holding portions 64 and 74 with the recesses 53b and 53b of the case 50, the workability when mounting the cover substrate 40 to the case 50 can be improved.

The holding portions 64 and 74 have bending pieces bent toward the case 50, and the bending direction of the bending pieces substantially coincides with the direction in which the tip portions 62 and 72 of the conductive terminals 60 and 70 elastically press the piezoelectric vibrating reed 20. When the piezoelectric sounding body 20 is surface-mounted on, for example, a circuit board, the mounting-side outer surface 41a of the cover substrate 40 may be disposed so as to face the surface of the circuit board.

Therefore, solder fillets are formed on the outer surfaces of the holding portions 64 and 74, which are bent pieces bent toward the case 50, and the solder fillets are formed on the land portions of the circuit board, so that the connection can be easily confirmed. Further, since the stepped portion 51 of the case 50 suppresses the piezoelectric vibrating reed 20 and is connected by the elastic pressure of the distal end portions 62 and 72 of the elastic conductive terminals 60 and 70, the distal end portions 62 and 72 of the elastic conductive terminals 60 and 70 can be surely connected to the electrode 22a and the vibrating reed 24 of the piezoelectric vibrating reed 20. In addition, when mounting, the piezoelectric vibrating reed 20 is placed on the conductive terminals 60 and 70, and the weight of the piezoelectric vibrating reed 20 itself also acts on the conductive terminals 60 and 70, so that more reliable connection between the conductive terminals 60 and 70 and the piezoelectric vibrating reed 20 can be ensured.

As shown in fig. 1B, in the present embodiment, the cover substrate 40 has at least one engaging protrusion 46 for engaging with the housing 50 on the outer periphery thereof, and the housing 50 has at least one engaging recess 56 corresponding to the shape of the engaging protrusion 46. With this configuration, the lid-like base sheet 40 can be easily positioned and joined to the housing 50.

In the present embodiment, the cover substrate 40 has a plurality of peripheral corners, and the engagement convex portion 46 protruding outward on the same plane as the cover substrate 40 is formed at least one peripheral corner. In the present embodiment, the lid substrate 40 is formed with the joining projections 46 at 4 outer peripheral corners thereof.

As shown in fig. 2B, in the present embodiment, the bottom surface and the side surface of the joining recessed portion 56 are welded to the joining raised portion 46, but at least the side surface of the joining recessed portion 56 may be welded to the joining raised portion 46. The joining concave portion 56 and the joining convex portion 46 can be easily heat-welded, for example, by abutting a heating jig from the mounting-side outer surface 41a of the cover substrate 40 to the vicinity of the boundary of the joining convex portion 46 and the joining concave portion 56.

As shown in fig. 5A, the piezoelectric vibrating reed 20 is disposed in the housing space 55 so as to divide the housing space 55 into the first space 55A and the second space 55b, and in the present embodiment, the volume of the first space 55A is larger than the volume of the second space 55b, and the distal ends 62 and 72 of the conductive terminals 60 and 70 are disposed in the second space 55 b. The first space 55a serves as a main echo space for sound generated by vibration of the piezoelectric vibrating reed 20, and sound of a predetermined frequency is emitted from the sound emission hole 42. The second space 55b becomes a sub-echo space of sound generated by the vibration of the piezoelectric vibrating reed 20. The distal ends 62, 72 of the conductive terminals 60, 70 are disposed in the second space 55 b.

As shown in fig. 5A, the piezoelectric vibrating reed 20 is placed on a step portion 51 formed on an inner wall surface of the case 50 so as to be larger than an outer diameter of the inner bottom surface 52 of the case 50, and divides the housing space 55 into a first space 55A and a second space 55 b. With such a configuration, when the piezoelectric vibrating reed 50 is mounted, the opening of the housing space 55 of the case 50 is directed upward along the Z axis, whereby the piezoelectric vibrating reed 20 can be easily mounted on the case 50. Further, by forming the spaces 55a and 55b above and below the piezoelectric vibrating reed 20, the piezoelectric vibrating reed 20 can be sufficiently vibrated, and desired sound can be easily generated.

In the present embodiment, as shown in fig. 4, the lid substrate 40 has the stopper projection 49 for restricting the movement of the piezoelectric vibrating reed 20 shown in fig. 5A toward the conductive terminals 60 and 70. The stopper projection 49 is formed on the inner surface 41b of the lid substrate 40 so as to correspond to the shape of the outer periphery of the piezoelectric vibrating reed 20.

When surface mounting is performed on a circuit board or the like, the piezoelectric sounding body 20 is mounted on the circuit board or the like with the outer layer side outer surface 41a of the lid substrate 40 directed downward, but the piezoelectric vibrating reed 20 is displaced toward the conductive terminals 60 and 70 due to its own weight or an impact from the outside. In the present embodiment, the stopper projection 49 prevents the piezoelectric vibrating reed 20 from being excessively displaced toward the conductive terminals 60 and 70, and improves shock resistance. Further, since the stopper projection 49 is provided, the distal end portions 62 and 72 are not excessively deformed, and the elasticity of the distal end portions 62 and 72 is easily maintained.

In the present embodiment, as shown in fig. 4, the distal end portions 62 and 72 have substantially hemispherical contact convex portions 62b and 72 b. The contact protrusions 62b and 72b are in contact with the piezoelectric vibrating reed 20 shown in fig. 5A, and thus contact failure and the like can be effectively prevented. The piezoelectric vibrating piece 20 is generally in a disk shape, but may be in a rectangular disk shape or a polygonal disk shape.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

For example, the reinforcing holes 68d and 78d function to reinforce the fixation of the inner portions 68a and 78a of the conductive terminals 60 and 70 to the lid substrate 40, but need not necessarily be holes, and may be, for example, uneven reinforcing portions.

In the above-described embodiment, the tip portions 62 and 72 are in direct contact with the piezoelectric vibrating reed 20 without using solder or conductive paste, and the tip portions 62 and 72 are electrically connected to the piezoelectric vibrating reed 20 by pressing the piezoelectric vibrating reed 20 toward the case 50.

Claims (21)

1. A piezoelectric sounding body is characterized by comprising:

a piezoelectric vibrating piece;

a case that houses the piezoelectric vibrating reed therein;

a lid-like substrate attached to the case and forming a housing space for the piezoelectric vibrating reed together with the case; and

a conductive terminal electrically connected to the piezoelectric vibrating piece,

the conductive terminal has: a tip portion that elastically presses the piezoelectric vibrating reed toward the case; and a terminal main body connected to the front end portion,

at least a part of the terminal main body is embedded in the cover substrate and fixed.

2. The piezoelectric sounding body according to claim 1, characterized in that:

the tip portion has an inclined portion extending from the terminal main body to an outer edge of the lid substrate and inclined toward the piezoelectric vibrating reed.

3. The piezoelectric sounding body according to claim 1 or 2, characterized in that:

the cover substrate has a through hole communicating with the housing space from the outside of the cover substrate, and the tip portion is disposed inside the through hole so as to protrude from the cover substrate.

4. A piezoelectric sounding body according to claim 3, characterized in that:

the lid substrate has a groove portion extending from the through hole to an outer edge of the lid substrate and communicating an inside of the through hole with an outside of the case.

5. A piezoelectric sounding body according to claim 3, characterized in that:

the through-hole is formed by at least a pair of through-holes, and these through-holes communicate with each other inside the housing space.

6. The piezoelectric sounding body according to claim 1 or 2, characterized in that:

and a sound emission hole communicated from the accommodating space to the outside of the shell is formed on the side surface of the outer wall of the shell.

7. The piezoelectric sounding body according to claim 6, characterized in that:

the tip portion extends toward the outer wall side surface on the opposite side to the outer wall side surface of the case where the sound emission hole is formed.

8. Piezoelectric sounding body according to claim 1 or 2,

the terminal main body has:

an inner portion connected to the tip portion and substantially parallel to the piezoelectric vibrating reed;

an outer portion that is substantially parallel to the inner portion and is disposed so as to be located at a different height difference portion from the inner portion; and

an intermediate portion between the inner portion and the outer portion.

9. The piezoelectric sounding body according to claim 8, characterized in that:

the intermediate portion is connected to the inner side portion and the outer side portion, respectively, in an inclined manner with respect to the inner side portion and the outer side portion.

10. The piezoelectric sounding body according to claim 8, characterized in that:

the inner portion and the intermediate portion are embedded in the cover substrate.

11. The piezoelectric sounding body according to claim 8, characterized in that:

the inner side portion has a reinforcing portion for reinforcing fixation to the cover substrate.

12. The piezoelectric sounding body according to claim 8, characterized in that:

the inner side portion has a heat conduction reducing portion that reduces heat conduction toward the front end portion.

13. The piezoelectric sounding body according to claim 8, characterized in that:

the outer side portion and the outer surface of the cover substrate are located on the same plane.

14. The piezoelectric sounding body according to claim 1 or 2, characterized in that:

the conductive terminal has a holding portion connected to an outer side portion of the terminal body so as to protrude from the cover substrate at a position different from the tip portion, and the holding portion is engaged with the housing.

15. The piezoelectric sounding body according to claim 14, wherein:

the holding portion has a bending piece bent toward the housing, and a bending direction of the bending piece is substantially aligned with a direction in which the tip portion of the conductive terminal elastically presses the piezoelectric vibrating reed.

16. The piezoelectric sounding body according to claim 1 or 2, characterized in that:

at least one engaging projection for engaging with the housing is provided on the outer periphery of the cover-like substrate,

the housing has at least one engaging recess corresponding to the shape of the engaging protrusion.

17. A piezoelectric sounding body according to claim 16, wherein:

the cover substrate has a plurality of peripheral corner portions, and the engagement convex portion protruding outward on the same plane as the cover substrate is formed at least one peripheral corner portion.

18. A piezoelectric sounding body according to claim 16, wherein:

the bottom surface and the side surface of the engaging recess portion and the engaging projection portion are welded together.

19. The piezoelectric sounding body according to claim 1 or 2, characterized in that:

the piezoelectric vibrating reed is disposed inside the housing space so as to divide the housing space into a first space and a second space,

the volume of the first space is larger than the volume of the second space,

the front end of the conductive terminal is disposed in the second space.

20. The piezoelectric sounding body according to claim 1 or 2, characterized in that:

the piezoelectric vibrating reed is placed on a step portion formed on an inner wall surface of the case, and divides the housing space into a first space and a second space.

21. The piezoelectric sounding body according to claim 1 or 2, characterized in that:

the lid-like substrate has a stopper protrusion for restricting the piezoelectric vibrating reed from moving toward the conductive terminal.

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