JPH08274570A - Piezo-resonator - Google Patents

Abstract

PURPOSE: To provide a piezo-resonator capable of comprising with the minimum number of parts, making the surface packaging area of a printed circuit board small, facilitating an assembling process and with superior impact resistance. CONSTITUTION: A piezoelectric element 1 on both main faces of which vibrating electrodes 12, 13 and both terminal of which drawer electrodes 12a, 13a are formed is housed between two case substrates 2, 3 on both terminals of which terminal electrodes 22, 23, 32 and 33 are formed. In the piezo-resonator 10, the case substrates 2, 3 are provided with recessed parts 24, 34 extending in the longitudinal direction of a joining main face, and also, the drawer electrode 12a, 13a parts of the piezoelectric element 1 are supported with both terminals of the recessed parts 24, 34 so that the end face of the element 1 can be exposed from the end faces of the case substrates 2, 3. Moreover, the joining face of the two case substrates 2, 3 is joined with resin seal 5, and the drawer electrodes 12a, 13a of the piezoelectric element 1 is joined with the terminal electrodes 22, 23, 32 and 33 of the case substrates 2, 3 with a solder adhesive layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonator formed by sandwiching and sealing rectangular piezoelectric elements of thickness shear vibration mode between upper and lower case substrates.

[0002]

2. Description of the Related Art Piezoelectric resonators are often used as oscillators for clock signals in electronic equipment. For example, a piezoelectric element is housed in a container having terminal electrodes formed on a printed wiring board. Surface mountable. If necessary, an input / output capacitance component connected to the piezoelectric element was simultaneously formed in a part of the container.

In a typical piezoelectric element, vibration electrodes facing each other are formed on both main surfaces of a rectangular piezoelectric substrate having a thickness-shear vibration mode, and one end of the piezoelectric substrate has one vibration electrode. The extraction electrode drawn out from was formed, and the extraction electrode drawn out from the vibration electrode on the other side was formed at the other end. The extraction electrodes are formed on both main surfaces and end surfaces of the end portion of the piezoelectric element.

As shown in FIGS. 6 and 7, such a piezoelectric element has been used as a piezoelectric resonator housed in a container in which a terminal electrode is formed.

The piezoelectric resonator 60 shown in FIG. 6 has a piezoelectric element 61.
Was housed in a container composed of an upper case substrate 62 and a lower case substrate 63.

A cavity 64 for accommodating the piezoelectric element 61 is formed on the upper case substrate 62, and a step 64a for holding the end of the piezoelectric element 1 is provided at the end of the cavity 64 in the longitudinal direction. , 64b are formed. In the cavity portion 64 of the upper case substrate 62, the end portion of the piezoelectric element 61 is arranged so as to straddle the step portions 64a and 64b, and the end portion of the piezoelectric element 61 is placed on the step portion 64.
a, 64b sufficient amount of conductive paste 65a, 65b
Is supplied.

Terminal electrodes 66 and 67 are formed on the lower case substrate 63 so as to circulate around both main surfaces thereof. Then, the terminal electrodes 66, 67 on the inner main surface (bonding main surface) of the lower case substrate 63 serve as electrodes connected to the lead-out electrodes of the piezoelectric element 1 via the conductive pastes 65a, 65b, and the outer main surface The terminal electrodes 66 and 67 become electrodes connected to an external circuit.

Here, the upper case substrate 62 and the lower case substrate 63 are bonded to each other by the cavity portion 6 of the upper case substrate 62.
It was performed through a seal layer 68 made of an insulating resin or the like on the contact portion between the periphery of No. 4 and the lower case substrate 63.

In the above-described piezoelectric resonator 60, since the piezoelectric element 61 is completely housed in the cavity portion 64 of the upper case substrate 62, the dimension of the upper case substrate 62 in the longitudinal direction is much smaller than that of the piezoelectric element 61. Therefore, the piezoelectric resonator 60 becomes large in size, and the mounting area on the printed wiring board becomes large.

Further, the upper case substrate 62 and the lower case substrate 6
3 is formed on the entire circumference of the substrates 62 and 63, and the conductive paste 65 that connects the extraction electrode of the piezoelectric element 61 and the terminal electrodes 66 and 67 of the lower case substrate 63.
a and 65b are the upper case substrate 62 and the lower case substrate 63.
The structure is completely concealed by the above, and moreover, the joining process of the upper case substrate 62 and the lower case substrate 63, the extraction electrode of the piezoelectric element 61 and the terminal electrode 66 of the lower case substrate 63
Since the connecting portion with 67 is performed in the same step, the extraction electrode of the piezoelectric element 61 and the terminal electrode 6 of the lower case substrate 62.
Since the state of connection with Nos. 6 and 67 cannot be confirmed by visual inspection or the like, meticulous attention was required in assembly, and the connection reliability was insufficient.

In the piezoelectric resonator 70 shown in FIG. 7, the piezoelectric element 71 is sandwiched between two holding plates 74 and 75 each having a substantially U-shape in a plane direction, and the sealing plates 72 and 73 having a rectangular shape are used. It was sandwiched from the direction (JP-A-6-13835).

Piezoelectric element 71 of piezoelectric resonator 70 shown in FIG.
7, the piezoelectric element 71 has four holding plates and sealing plates 72 to 72.
It was contained in a container consisting of 75.

In this embodiment, the terminal electrodes 72a-75a,
72b to 75b are formed on both ends of the four holding plates and the sealing plates 72 to 75, respectively. The holding plates 74 and 75 sandwich the piezoelectric element 71 from the plane direction, and the sealing plates 72 and 73 sandwich the piezoelectric element 71 in the thickness direction. When the piezoelectric element 71 was adhered from, the lead electrode of the piezoelectric element 71 and the terminal electrodes 72a to 75a and 72b to 75b were electrically connected.

In the above-described embodiment, the contact area of the connection between the lead electrode of the piezoelectric element 71 and the terminal electrodes 72a to 75a and 72b to 75b is increased as compared with the conventional piezoelectric resonator 60 shown in FIG. The connection reliability is improved, and the size of the piezoelectric resonator 70 in the longitudinal direction is the same as that of the piezoelectric element 71, and the size can be reduced.

However, the container for accommodating the piezoelectric element 71 is 4
It is composed of two members (holding plate, sealing plates 72 to 75), adheres between the lower main surface of the upper sealing plate 72 and the upper surfaces of the left and right holding plates 74, 75, and further holds the left and right sides. Boards 74, 75
It is necessary to bond between the lower surface of the lower sealing plate 73 and the upper surface of the lower sealing plate 73, and the total of the two bonding surfaces is one. Holding plate 7
It had a structure in which three members of Nos. 4 and 75 had to be bonded.

Therefore, the assembling process becomes complicated, and at the same time, the rigidity of the container itself is lowered, and the impact resistance is greatly lowered.

The present invention has been devised in view of the above-mentioned problems, and an object of the present invention is to minimize the number of parts, reduce the surface mounting area of a printed wiring board, and improve the assembly process. An object is to provide a piezoelectric resonator that is easy and has excellent impact resistance.

[0018]

SUMMARY OF THE INVENTION According to the present invention, there are provided piezoelectric elements in which vibrating electrodes are formed on both main surfaces of a rectangular piezoelectric substrate, and lead-out electrodes connected to the vibrating electrodes are formed at both ends, and terminals are provided at both ends. In a piezoelectric resonator that is housed between two case substrates on which electrodes are formed, at least one of the case substrates has a recess extending in the longitudinal direction of the main bonding surface, and a lead electrode portion of the piezoelectric element is provided. , The piezoelectric element is supported by a recess in which at least a terminal electrode is formed so that the end surface of the piezoelectric element is exposed from the end surface of the case substrate, and at least the joint surface of the two case substrates in which the terminal electrodes are not formed is sealed with a resin. It is a piezoelectric resonator in which a lead electrode of a piezoelectric element and a terminal electrode of a case substrate are joined by solder.

[0019]

Since the piezoelectric resonator of the present invention comprises the piezoelectric element and the upper and lower two case substrates, which is the minimum number of parts, the assembly process is simplified and the cost can be reduced.

In addition, since the upper and lower case substrates are one main surface of the joint between the two upper and lower case substrates, the rigidity of the piezoelectric resonator is improved in combination with the minimum number of parts, and the external impact resistance is improved. The piezoelectric resonator has excellent properties.

Furthermore, since the size of the piezoelectric element in the longitudinal direction is the same as the size of the upper and lower case substrates in the longitudinal direction, the mounting area on the printed wiring board can be minimized.

Further, in the joining and sealing of the upper and lower case substrates, resin sealing is performed in a portion where both case substrates where the terminal electrodes are not formed are in contact with each other, and soldering is performed in a portion where the terminal electrodes are formed. ing.

In particular, this sealing of the solder can also serve as an electrical connection between the piezoelectric element and the terminal electrode of the case substrate, and since this is the end face portion where the connection state can be visually confirmed, the piezoelectric element The reliability of electrical connection between the extraction electrode and the terminal electrodes of the upper and lower case substrates can be improved.

In particular, the sealing with the solder can be performed by a solder dipping method, which is excellent in mass productivity, and the sealing with the resin seal is performed by hardening the resin by heat treatment. The piezoelectric resonator can be stopped and is excellent in mass productivity.

Further, since the structures of the upper case substrate and the lower case substrate can be made substantially the same, in this way, there are only two types of parts, that is, the piezoelectric element and the case substrate. The piezoelectric resonator has improved properties.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The piezoelectric resonator of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an external perspective view of a piezoelectric resonator of the present invention, FIG. 2 is an exploded perspective view, FIG. 3 is a longitudinal sectional view of the piezoelectric resonator, and FIG. 4 is a transverse sectional view of the piezoelectric resonator. It is a figure.

The piezoelectric resonator 10 is mainly composed of a piezoelectric element 1 and two case substrates 2 and 3 which are containers.
Here, one case substrate is referred to as an upper case substrate 2, and the other case substrate is referred to as a lower case substrate 3.

The upper and lower case substrates 2 and 3 are joined to each other by a solder adhesion layer 4 and a resin sealing layer 5 made of high temperature solder.
Is done by.

The piezoelectric element 1 is a piezoelectric substrate 11 such as a piezoelectric ceramic substrate polarized so as to have a thickness-shear vibration mode or a piezoelectric single crystal substrate cut in a predetermined manner.
And vibrating electrodes 12 and 13 and extraction electrodes 12a and 13a.

For example, vibrating electrodes 12 and 13 are formed on both main surfaces of the piezoelectric substrate 11 so as to face each other, and one end of the piezoelectric substrate 11 is connected to the vibrating electrode 12. An electrode 12a is adhered and formed, and a lead electrode 13a connected to the vibrating electrode 13 is formed on the other end of the piezoelectric substrate 11.
Has been formed. Incidentally, this extraction electrode electrode 12a,
13a is formed on at least both main surfaces and end surfaces of both ends, and in FIG. 2, it is further formed on five surfaces of both side surfaces.

The vibrating electrodes 12, 13 and the extraction electrode 12
Each of a and 13a is made of a metal conductor film containing Ag as a main component, and the forming method is a thin film technique such as vapor deposition or a thick film technique such as coating baking.

The upper case substrate 2 and the lower case substrate 3 have the same structure. For example, the lower case substrate 3 is composed of a heat-resistant flat insulating substrate 31 made of ceramic or the like.
A concave portion 34 is formed so as to penetrate both end sides in the longitudinal direction of 1. The recess 34 has a wide portion 34a having a slightly larger width and depth in the vicinity of the central portion and the piezoelectric element 1 placement recesses (hereinafter referred to as placement recesses) 34b, 3b which appear on both end surfaces.
It consists of 4b.

Terminal electrodes 32 and 33 are formed on both ends of the lower case substrate 3 in the longitudinal direction. Specifically, the terminal electrodes 32 and 33 are formed on at least both main surfaces and end surfaces of the end portion of the insulating substrate 31, and are further formed on both side surfaces in FIG. That is, since the terminal electrodes 32 and 33 are formed on the main surface, they are also formed on the inner surfaces of the arrangement recesses 34b and 34b.

The terminal electrodes 32 and 33 are formed by printing and baking using a conductor paste containing Ag as a main component, such as Ag paste or Ag-Pd paste.

Here, the width of the arrangement recesses 34b, 34b in which the terminal electrodes 32, 33 are formed is set to be about 50 μm to 200 μm larger than the width of the piezoelectric element 1, and the arrangement recesses 34b, 34b are also set. The depth is set to substantially 1/2 the thickness of the piezoelectric element 1, for example, 0.1 mm or more.

Although the above description has been made using the lower case substrate 3 which mainly appears in FIG. 3, the upper case substrate 2 has the same structure. Therefore, when the main bonding surfaces of the upper case substrate 2 and the lower case substrate 3 are brought into contact with each other, both end faces of the upper case substrate 2 and the lower case substrate 3 have substantially the same end face shape as the piezoelectric element 1. A through hole will be formed.

In such a structure, the extraction electrodes 12a and 13a at both ends of the piezoelectric element 1 are arranged in the arrangement recesses 24b, 24b, 34b and 34b of the upper and lower case substrates 2 and 3, respectively. It is sandwiched between the substrates 2 and 3.

The joint main surfaces that abut each other on the upper and lower case substrates 2 and 3 are firmly joined by the resin seal layer 5 and the solder adhesion layer 4.

The resin seal layer 5 is made of an insulating adhesive resin such as an epoxy resin or a phenol resin, and is provided with a recess 34 on the main surface of either or both of the upper and lower case substrates 2 and 3 which are bonded to each other. Formed around.

For example, the resin seal layer 5 formed on the lower case substrate 3 is long in the region where the terminal electrodes 32 and 33 are not formed, that is, in the region where the insulating substrate 31 between the terminal electrodes 32 and 33 is exposed. It is formed so as to extend in the direction. The resin seal layer 5 is formed on the lower case substrate 3 by applying a predetermined insulating adhesive resin and then primary curing. It should be noted that a complete seal layer is formed by performing heat treatment again after contacting with the upper case substrate 2. The width of the resin seal layer 5 is, for example, 0.2 to 0.
It is 5 mm.

The solder adhesion layer 4 is mainly composed of the terminal electrode 3.
It is to be sealed / joined in the area where 2, 33 are formed. Specifically, since it is formed by the solder dip method or the like, the solder adhesion layer 4 has the terminal electrodes 22, 23, 32, 3
3 and the end faces of the piezoelectric element 1 on which the extraction electrodes 12a and 13a are formed. At this time, the solder intrudes into the gap generated at the joint between the upper and lower case substrates 2 and 3 due to the capillary phenomenon of the molten solder, and the terminal electrode 22-
32, 23-33, the gap is completely sealed by the surface tension of the molten solder.

Therefore, the resin sealing layer 5 as the sealing member
Is hermetically sealed mainly in the portions where the terminal electrodes 22, 23, 32, 33 are not formed, and the solder adhesion layer 4 is mainly formed in the portions where the terminal electrodes 22, 23, 32, 33 are formed. It will be hermetically sealed.

Next, a method of assembling the piezoelectric element 1, the upper case substrate 2 and the lower case substrate 3 will be described.

First, the resin seal layer 5 is formed on one or both of the lower case substrate 2 and the upper case substrate 3. The seal layer 5 is applied, for example, by using an epoxy-based insulating adhesive resin around the substrate on which the terminal electrodes are not formed, and then heat-treated to perform primary curing.

Next, the extraction electrodes 12 on both ends of the piezoelectric element 1
a and 13a are, for example, arrangement recesses 34 of the lower case substrate 3.
b and 34b.

Next, the piezoelectric element 1 protruding above the lower case substrate 3 is arranged so that the extraction electrodes 12a and 13a at both ends thereof are located in the arrangement recesses 24b and 24b of the upper case substrate 2. Coat 2.

Next, with the piezoelectric element 1 sandwiched between the upper case substrate 2 and the lower case substrate 3, the piezoelectric element 1 is dipped in a solder dip bath in which high temperature solder is melted and pulled up.

As a result, the terminal electrodes 22, 23, 32, 33 formed on the upper case substrate 2 and the lower case substrate 3 and the end faces of the piezoelectric element 1 exposed from the end faces in the longitudinal direction of the upper and lower case substrates 2, 3 are exposed. Solder will adhere to the lead electrodes 12a and 13a, and the melted solder will join the terminal electrodes 23, 23, 32 and 33 of the upper and lower case substrates 2 and 3 and the lead electrodes 12a and 13b of the piezoelectric element 1 respectively. It penetrates into the gaps of the portions and fills and joins the gap portions.

As a result, the terminal electrodes 22, 23, 32,
Airtight sealing is performed at the portion 33, and the extraction electrodes 12a and 13a of the piezoelectric element 1 and the terminal electrodes 22 and 23,
An electrical connection with 32, 33 is achieved. Since this electrical connection can be visually confirmed from the end faces of the joined upper and lower case substrates 2 and 3 in the longitudinal direction, the reliability of the connection is greatly improved. During the solder dipping process, the terminal electrodes 22 and 2 formed on the outer side of the upper and lower case substrates 2 and 3, respectively.
The surface of 3, 32, 33 is also coated with solder, which promotes the reliability of solder joining when the surface mounting is performed on the printed wiring board.

At this time, the terminal electrodes 22, 23, 32,
Upper and lower case substrates 2, 3 in a region where 33 is not formed
Since the terminal electrode is not formed at the joint portion, the solder does not adhere to the joint portion, and the resin seal layer 5 is formed at the joint surface portion, so that the solder has a depression 24.
a, 34a does not enter.

Next, in this state, heat treatment is performed at a predetermined temperature to completely cure the resin seal layer 5 formed on the upper and lower case substrates 2 and 3 to completely hermetically seal the upper and lower case substrates 2 and 3. I do. The heat treatment conditions differ depending on the resin material of the resin seal layer 5, and are, for example, about 150 ° C. to 200 ° C. for epoxy-based and phenol-based resin adhesives.

As described above, the piezoelectric resonator 10 is composed of the piezoelectric element 1 and the upper and lower two case substrates 2 and 3 of two types and the number of parts, so that the assembling process becomes very simple.
The productivity in forming the case substrate is improved, and the cost can be reduced.

Further, since the upper and lower case substrates 2 and 3 are joined to each other substantially on the surface where the upper and lower case substrates 2 and 3 are in contact with each other, the piezoelectric resonator 10 is combined with the minimum number of parts.
Piezoelectric resonator 1 with improved rigidity and excellent external shock resistance
It becomes 0.

Further, since the longitudinal dimension of the piezoelectric element 1 and the longitudinal dimension of the upper and lower case substrates 2 and 3 are the same, the piezoelectric resonator 10 has a very small mounting area on the printed wiring board. You can

Further, since the terminal electrodes 22, 32 and 23, 33 are arranged in the longitudinal direction of the upper and lower case substrates 2, 3, the piezoelectric resonator 10 is mounted on the printed wiring board without discrimination between the front and back sides. be able to.

Further, in the joining and sealing of the upper and lower case substrates 2 and 3, a resin seal 5 is used at the portion where the case electrodes 2 and 3 where the terminal electrodes 22, 23, 32 and 33 are not formed are in contact with each other. Terminal electrodes 22, 23, 3
2 and 33 are formed by the solder adhesion layer 4 of high-temperature solder, and in particular, the solder adhesion layer 4 is used for the piezoelectric element 1 and the terminal electrodes 2 of the case substrates 2 and 3.
Since it can also serve as an electrical connection with 2, 23, 32, and 33, and the connection state can be visually confirmed from the end face portions of the case substrates 2 and 3, the connection reliability is greatly improved.

The solder adhesion layer 4 can be formed by a solder dipping method, which is excellent in mass productivity, and the resin seal layer 5 can be formed by curing the resin by heat treatment, so that all of them can be performed collectively. The piezoelectric resonator 10 can be reliably sealed by various treatments and is excellent in mass productivity.

FIG. 5 is an exploded perspective view showing another piezoelectric resonator 50 of the present invention.

In this embodiment, for example, the lower case substrate 53 is formed into a shape close to a flat plate, and a space for allowing the vibration of the piezoelectric element 1 is secured on the main surface of the lower case substrate 53 on the bonding side. Therefore, only the recessed portion 54a is formed, and the portion connected to the extraction electrodes 12a and 13a of the piezoelectric element 1 is
It is the main surface of the lower case substrate 53.

Further, for example, the concave portion 24 formed in the upper case substrate 52, that is, the concave portion 24a (not shown in FIG. 5),
The depth of the arrangement recessed portion 24b is the recessed portion 24 shown in FIGS.
a, it is necessary to have a sufficient depth as compared with the arrangement recess 24b. Specifically, the depth of the placement recess 24b is substantially the same as the thickness of the piezoelectric element 1, and the recess 24a has a depth equal to or greater than the placement recess 24b.

With such a structure, for example, the piezoelectric element 1 is arranged on the upper case substrate 52 so that the extraction electrodes 12a, 13a of the piezoelectric element 1 are arranged in the concave portions 24b, 24b of the upper case substrate 52. After that, the joint between the lower case substrate 53 and the upper case substrate 2 can be positioned and sandwiched so that the outer peripheries of the lower case substrate 53 and the upper case substrate 2 coincide with each other, so that the assembly process is further simplified.

In each of the above-mentioned embodiments, the piezoelectric resonators 10 and 50 are provided with a pair of terminal electrodes.
A third terminal electrode may be formed on the upper and lower case substrates 2, 3, 52 and 53 to generate an input / output capacitance with the pair of terminal electrodes. Accordingly, in terms of a circuit, a predetermined capacitance component is added to both ends of the piezoelectric element 1 with respect to the ground potential, and the oscillation circuit connected to this piezoelectric resonator 10 can be simplified. .

[0064]

As described above, a rectangular piezoelectric element is sandwiched between two case substrates each having a recess formed in at least one substrate, and is sealed with a resin seal layer and a solder adhesion layer. Since the number of parts is very small, that is, three points of the piezoelectric element and the upper and lower two case substrates, and the bonding surface is substantially one surface, the assembly process is simplified and the cost is reduced. Moreover, the rigidity of the piezoelectric resonator is improved, and the piezoelectric resonator has excellent external shock resistance.

Furthermore, the end face portion of the piezoelectric element on which the extraction electrode is formed is exposed from the end face of the case substrate, and the piezoelectric element and the case substrate are mechanically and electrically joined by soldering on this face. Therefore, structurally, the longitudinal dimension of the piezoelectric resonator and the longitudinal dimension of the piezoelectric resonator can be the same, and the mounting area on the printed wiring board can be minimized. The connection state between the lead electrode of the piezoelectric element and the terminal electrode on the case substrate side can be visually confirmed, and the connection reliability is improved.

Further, since the upper and lower case substrates on which the terminal electrodes are not formed are joined and sealed by the insulating resin seal, a short circuit of the pair of terminal electrodes is prevented and stable sealing is performed. be able to.

In particular, the sealing with the solder can be performed by the solder dipping method, which is excellent in mass productivity, and the sealing with the resin seal is performed by hardening the resin by heat treatment. The piezoelectric resonator can be stopped and is excellent in mass productivity.

[Brief description of drawings]

FIG. 1 is an external perspective view of a piezoelectric resonator of the present invention.

FIG. 2 is an exploded perspective view of the piezoelectric resonator of the present invention.

FIG. 3 is a vertical sectional structural view of a piezoelectric resonator of the present invention.

FIG. 4 is a cross-sectional structural diagram of a piezoelectric resonator of the present invention.

FIG. 5 is an exploded perspective view of another piezoelectric resonator of the present invention.

FIG. 6 is a longitudinal sectional structural view of a conventional piezoelectric resonator.

FIG. 7 is an exploded perspective view of a conventional piezoelectric resonator.

[Explanation of symbols]

 10, 50 ... Piezoelectric resonator 1 ... Piezoelectric element 2, 52 ... Upper case substrate 21 ... Insulating substrate 22 ... Terminal electrode 23 ... Terminal electrode 24 ... Bump portion 24b ..Metal coating part 3, 53 ... Lower case substrate 31, 51 ... Insulating substrate 32 ... Terminal electrode 33 ... Terminal electrode 34 ... Bump part 4 ... Solder adhesion layer 5 ... Resin seal layer

Claims (1)

[Claims] 1. A piezoelectric element in which a vibrating electrode is formed on both main surfaces of a rectangular piezoelectric substrate, and lead-out electrodes for connecting to the vibrating electrode are formed on both ends of the piezoelectric element, and terminal electrodes are formed on two end portions of the piezoelectric element. In a piezoelectric resonator housed between case substrates, the at least one case substrate has a recess extending in the longitudinal direction of the main bonding surface, and the lead electrode portion of the piezoelectric element has an end face of the piezoelectric element whose case surface is the case substrate. Supported by at least the concave portion where the terminal electrode is formed so as to be exposed from the end surface of the piezoelectric element, the joint surface of the two case substrates is sealed with a resin, and the lead electrode of the piezoelectric element and the terminal electrode of the case substrate are soldered. A piezoelectric resonator characterized by being bonded.