JP3915117B2 - Piezoelectric vibration device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piezoelectric vibration device typified by a crystal resonator or the like. In particular, a mesa structure in which a central portion including a main vibration portion, an outer frame portion formed so as to surround the central portion, and a step portion connecting the central portion and the outer frame portion are integrally formed of a piezoelectric material. Or it is related with the electrode structure of the piezoelectric vibration device comprised by the reverse mesa structure.
[0002]
[Prior art]
With the increase in the frequency of communication equipment and the increase in the operating frequency of microcomputers, piezoelectric vibration devices such as crystal resonators and crystal filters are also required to have higher frequencies. In general, the thickness shear vibration of an AT-cut quartz plate is often used as a quartz plate (quartz plate) that supports high frequency. As is well known, the frequency is determined by the thickness of the quartz plate, Thickness is inversely proportional. For example, when an attempt is made to obtain 600 MHz as the fundamental vibration frequency, an ultra-thin crystal diaphragm of 3 μm or less is required. Such an ultra-thin plate processing is difficult to polish and it is difficult to improve the manufacturing yield.
[0003]
In order to solve this problem, as disclosed in Patent Document 1, a concave portion is provided by a processing technique such as etching in the central portion of the crystal diaphragm, and the main vibration portion (central portion) is thinly processed at the bottom of the concave portion. ) And a so-called inverted mesa type structure is proposed in which the vibration region is reinforced by a thick reinforcing portion (outer frame portion) around the stepped portion. This type of crystal diaphragm has a configuration in which an excitation electrode and an extraction electrode are formed on a crystal diaphragm having a thinned main vibration portion and a reinforcing portion formed around the main vibration portion. By adopting such a configuration, the main vibration part can be made considerably thinner than the conventional one, and the yield can be improved.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2-231808
[Problems to be solved by the invention]
By the way, in the crystal diaphragm as described above, the extraction electrode has a stepped portion connecting the main vibration portion and the outer frame portion, and when the extraction electrode is thin, the top portion of the stepped portion is produced at the time of manufacture or the like. In the (ridge portion), the lead electrode may be disconnected. In particular, since the quartz diaphragm is an anisotropic piezoelectric crystal, the etching speed varies depending on the etching direction (crystal axis). The order of the etching speed is Z ′> + X>−X> Y ′ (in the case of an AT-cut quartz crystal, a new axis shifted by θ ° from the Z axis is referred to as Z ′, and θ ° shifted from the Y axis. The new axis is called Y '.) For this reason, since the inclination angle of the stepped portion differs depending on the direction, the apex portion (ridge portion) having an acute angle and the apex portion (ridge portion) having an obtuse angle are mixed, and the disconnection rate of the extraction electrode in the step portion having an acute angle is extremely high. Met. Patent Document 1 proposes that the above-described disconnection is prevented by forming an electrode on the entire surface on the side where the recess is formed.
[0006]
However, in the configuration of Patent Document 1, since the electrode on one main surface is a full surface electrode, there is a region where the electrodes are opposed to each other in the extraction electrode portion other than the excitation electrode. There is a problem that electrical characteristics such as CI value (crystal impedance) are adversely affected and it is difficult to obtain more stable electrical characteristics. Moreover, since the electrode of one main surface is a full surface electrode, the freedom degree of design, such as an excitation electrode and an extraction electrode, is also restrict | limited.
[0007]
Furthermore, since the configuration of Patent Document 1 can be applied only to a configuration in which a concave portion is formed only on one main surface, when the main vibration portion is thin-walled, it is much more difficult than a configuration in which concave portions are formed on both main surfaces. Since the depth of the portion becomes deeper, the processing time becomes longer as the frequency becomes higher (the main vibration portion is made thinner), and the yield tends to be reduced due to surface roughness of the main vibration portion.
[0008]
The present invention has been made in view of the above points, and an object of the present invention is to break a lead electrode in a piezoelectric vibration device having a step portion connecting a main vibration portion and an outer frame portion capable of responding to high frequency. It is an object of the present invention to provide a highly reliable piezoelectric vibration device that can prevent the formation of electrodes and can form electrodes with a higher degree of design freedom, and has more stable electrical characteristics.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a central portion including a main vibration portion, an outer frame portion formed so as to surround the central portion, and a step portion connecting the central portion and the outer frame portion. Is a piezoelectric vibration device integrally formed of a piezoelectric material,
An excitation electrode formed at a central portion of the piezoelectric vibration device; a first extraction electrode extending from an end portion of the excitation electrode and formed at least at the central portion and the outer frame portion of the piezoelectric vibration device; Having a second extraction electrode formed in the central part of the device and the outer frame part,
The first extraction electrode extends from the end portion of the excitation electrode toward a specific region where step portions having different surface directions are close to each other,
The second extraction electrode is formed on and electrically connected to the upper surface of the first extraction electrode in the specific region, and passes through each step portion having a different surface direction from the specific region. It is formed at the end of the outer frame portion of the piezoelectric vibration device and constitutes an external connection terminal.
[0010]
More specifically, the center portion is formed in a polygonal shape, and the specific region where the step portions having different surface directions are close to each other is a corner portion of the center portion.
[0011]
Further, a piezoelectric vibration formed by integrally forming a central portion having a main vibration portion, an outer frame portion formed so as to surround the central portion, and a step portion connecting the central portion and the outer frame portion with a piezoelectric material. A device,
A central extension part is formed in which a part of the central part extends to the vicinity of the edge of the outer frame part,
An excitation electrode formed at a central portion of the piezoelectric vibration device; a first extraction electrode extending from an end portion of the excitation electrode; and formed at least at the central portion and the central extension portion of the piezoelectric vibration device ; A central extension portion of the vibration device and a second extraction electrode formed on the outer frame portion;
The first extraction electrode extends from an end portion of the excitation electrode toward a specific region of the central extension portion,
The second extraction electrode is formed on and electrically connected to the upper surface of the first extraction electrode in the specific region, and passes through each step portion having a different surface direction from the specific region. It is formed at the end of the outer frame portion of the piezoelectric vibration device and constitutes an external connection terminal.
[0012]
【The invention's effect】
According to the first aspect of the present invention, the extraction electrode that extends the excitation electrode of the piezoelectric vibration device to the external connection terminal is externally connected to the first extraction electrode formed integrally with the excitation electrode and the stepped portion. By separately configuring and electrically connecting the second extraction electrodes constituting the connection terminal, it is possible to form electrodes in separate processes, and thus it is possible to form extraction electrodes that are less likely to cause disconnection.
[0013]
In addition, since the first extraction electrode and the second extraction electrode are extended only to specific regions where step portions having different plane directions are close to each other and are electrically connected to each other, in the regions other than the excitation electrode, Electrodes with different polarity do not face each other on the front and back sides, and variations in electrode formation do not adversely affect electrical characteristics such as the CI value (crystal impedance), resulting in more stable electrical characteristics. Therefore, it is possible to form an electrode with a higher degree of design freedom.
[0014]
Further, since the second extraction electrode is formed to the end portion of the outer frame portion of the piezoelectric vibration device via the respective step portions having different surface directions, at the top portion (ridge portion) of one step portion, Even if a part of the second extraction electrode is disconnected, conduction can be ensured at another stepped portion. In particular, in the case of a quartz diaphragm, the second extraction electrode does not go through only the top of the stepped portion having an acute angle, but also passes through the top of the stepped portion having a more obtuse angle. At the top, the second extraction electrode is not disconnected, and stable conduction can be ensured.
[0015]
According to claim 2 of the present invention, in addition to the above-described effects, the central portion is formed in a polygonal shape, and the corner portion of the central portion is a specific region where the stepped portions having different surface directions are close to each other. Therefore, positioning when forming each extraction electrode is easy, highly accurate electrode formation can be performed, mechanical contact is less likely to occur compared to the center of the top of the stepped portion, and the risk of disconnection is extremely high. Low configuration.
[0016]
According to the third aspect of the present invention, the extraction electrode that extends the excitation electrode of the piezoelectric vibration device to the external connection terminal is externally connected to the first extraction electrode formed integrally with the excitation electrode and the step portion. By separately configuring and electrically connecting the second extraction electrodes constituting the connection terminal, it is possible to form electrodes in separate processes, and thus it is possible to form extraction electrodes that are less likely to cause disconnection.
[0017]
In addition, since the first extraction electrode and the second extraction electrode extend only in a specific region of the central extension portion and are electrically connected to each other, electrodes having different polarities in regions other than the excitation electrode The front and back surfaces do not face each other, and variations in electrode formation do not adversely affect the electrical characteristics such as the CI value (crystal impedance), resulting in more stable electrical characteristics and greater design freedom. High electrode formation can be performed.
[0018]
Further, since the first extraction electrode and the second extraction electrode are formed in a central extension portion in which a part of the central portion extends to the vicinity of the edge of the outer frame portion, Are arranged in the state of being close to each of the extraction electrodes, mechanical contact at the top of the stepped portion hardly occurs, and the risk of disconnection can be drastically reduced. Since a part of the central part is formed in the central extension part extending to the vicinity of the edge of the outer frame part, the second electrode is not adversely affected on the excitation electrode formed in the central part. The extraction electrode can be formed.
[0019]
Moreover, since the 2nd extraction electrode is formed in the edge part of the outer frame part of a piezoelectric vibration device via each level | step difference part from which the surface direction of a center extension part differs, the top part of one level | step-difference part ( Even if a part of the second extraction electrode is disconnected at the ridge portion, conduction can be ensured at another step portion. In particular, in the case of a quartz diaphragm, the second extraction electrode does not go through only the top of the stepped portion having an acute angle, but also passes through the top of the stepped portion having a more obtuse angle. At the top, the second extraction electrode is not disconnected, and stable conduction can be ensured.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case where the present invention is applied to a quartz crystal plate constituting an AT-cut quartz crystal resonator as a piezoelectric vibrating device will be described.
[0021]
(First embodiment)
-Configuration of crystal diaphragm 1-
FIG. 1 is a plan view of a crystal diaphragm 1 according to a first embodiment of the present invention, and FIG. 2 is a bottom view of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 4 to 6 are views showing the manufacturing method of this embodiment.
[0022]
The crystal diaphragm 1 according to the present embodiment is formed of, for example, a flat rectangular AT-cut crystal diaphragm, a center portion 11 having an inverted mesa structure, an outer frame portion 12 surrounding the center portion 11, and the center portion and the outer frame portion. Are formed integrally with stepped portions 13 and 14 as internal side walls.
[0023]
For example, step portions 131, 132, 133, and 134 having different surface directions are formed as the step portion 13 on the front surface side, and the step portion 141 having different surface directions is used as the step portion 14 on the back surface side. , 142, 143, 144 are formed, and on each front and back main surface, a rectangular concave portion constituting an extremely thin main vibration portion (piezoelectric vibration region) is formed. The outer frame portion 12 is formed as a reinforcing portion having a thickness dimension several times that of the central portion. In the crystal plate of the present invention, the front and back directions are the Y-axis direction (the front side is the + Y ′ axis and the back side is the −Y axis), and the direction in which the step portions 131 and 133 extend is the crystal plate. (The direction of the step 131 is the + X axis and the direction of the step 133 is the −X axis), and the direction in which the step 132 and 134 extend is Z ′ of the quartz plate. It is an axial direction (the direction of the stepped portion 132 is the + Z axis, and the direction of the stepped portion 134 is the −Z ′ axis). Such concave portions are formed by a wet etching method described later.
[0024]
Excitation electrodes 21 and 22 are respectively formed in the central portions of the concave portions on the front and back surfaces. The excitation electrode 21 is extended from the end portion toward the corner portion 151 of the central portion where the step portions 131 and 132 having different surface directions are close to each other by the first extraction electrode 23, and close to the corner portion. It forms to the corner | angular part 121 of the outer frame part 12 via the level | step-difference parts 131 and 132 which do. The excitation electrode 22 is extended from the end portion toward the corner portion 164 of the central portion where the step portions 141 and 144 having different surface directions are close to each other by the first extraction electrode 24, and close to the corner portion. It is formed to the corner 122 of the outer frame portion 12 through the stepped portions 141 and 144. These electrodes are formed by a vacuum vapor deposition method or the like, and each electrode material is made of, for example, a material in which gold is laminated on the upper surface of chromium.
[0025]
In addition, the corners 121 and 122 of the outer frame portions on the front and back surfaces are formed with second lead electromotives 25 and 26 that are electrically connected to the excitation electrodes 21 and 22 and constitute external connection terminals. Yes. These second extraction electrodes are formed in separate steps after the excitation electrode and the first extraction electrode are formed. The second extraction electrode 25 passes through stepped portions 131 and 132 that are close to the corner portion from the vicinity of the corner portion 151 of the central portion so as to overlap with a part of the first extraction electrode 23 at the top. Thus, it is formed at the corner 121 of the outer frame 12 to constitute an external connection terminal. The second extraction electrode 26 passes through stepped portions 143 and 144 close to the corner portion from the vicinity of the corner portion 163 of the central portion so as to overlap with a part of the first extraction electrode 24 at the top. Thus, it is formed at the corner 122 of the outer frame 12 to constitute an external connection terminal. These electrodes are formed by a vacuum vapor deposition method or the like, and each electrode material is made of, for example, a laminate of silver on the upper surface of chromium and chromium on the upper surface. These second extraction electrodes are preferably formed wider than the width of the first extraction electrode.
[0026]
With the above configuration, since the first extraction electrode and the second extraction electrode are configured separately, for example, the second extraction electrode can be formed in a separate process closer to the final process. Thus, it is possible to form an extraction electrode that is less likely to cause disconnection. Further, since the second extraction electrode is formed to the end portion of the outer frame portion of the piezoelectric vibration device via two step portions having different plane directions, at the top portion (ridge portion) of one step portion, Even if a part of the second extraction electrode is disconnected, conduction can be ensured at another stepped portion. In particular, in the case where a quartz diaphragm is used as in the present embodiment, the second extraction electrode does not go through only the tops of the tops of the stepped parts 132 and 144 having an acute angle, but a stepped part having a more obtuse angle. Since the top portions of 131 and 143 are also passed, the second extraction electrode is not disconnected at the top portion of the step portion on the obtuse angle side, and stable conduction can be ensured.
[0027]
The role of the second lead electrode is to conduct with the first lead electrode and to be connected to an external electrode pad of a ceramic package, which will be described later, through a conductive bonding material as an external connection terminal. Accordingly, the excitation electrode and the first extraction electrode material are made of chromium + gold and the second extraction electrode is made of chromium + silver + chromium as in the present invention, so that the first extraction electrode and the second extraction electrode are made. The conduction with the electrode is stable, and the compatibility with the conductive bonding material (especially silicon) is good, so the conduction with the external electrode pad of the ceramic package is also stable.
[0028]
Although not shown, such a piezoelectric vibration device is housed in a package made of ceramics such as alumina, and is electrically connected to external electrode pads of the ceramic package in order to lead each external connection terminal to the outside. Then, a surface-mounted crystal resonator can be obtained by airtightly bonding the upper surface of the package with a cover plate.
[0029]
In the above-described embodiment, the first extraction electrode is extended only to one corner portion of the square central portion as the specific region where the step portions having different plane directions are close to each other, and the second extraction electrode and the second extraction electrode are electrically connected to each other. However, the central portion may have another polygonal shape, and the first extraction electrode may be extended to a plurality of corner portions and electrically connected to the second extraction electrode. .
[0030]
-Machining method of crystal diaphragm 1-
Next, a method for processing the crystal diaphragm 1 according to the above embodiment will be described with reference to FIGS. 4, 5, and 6.
[0031]
Fig. 4 <Etching of crystal diaphragm>
1—A resist film MR having a two-layer structure of Cr and Au is deposited on the entire front and back surfaces of the quartz crystal plate 1.
2- A negative type resist film NR is formed on the upper surface.
Using a 3-photolithography technique, an area excluding the area corresponding to the central portion 11 on the front and back surfaces of the quartz crystal plate 1 is exposed and developed.
4- The resist film MR (Au and Cr) in the region corresponding to the central portion 11 is subjected to metal etching with an etching solution.
5- By removing the negative type resist film NR and performing wet etching with an etching solution such as hydrofluoric acid + ammonium fluoride solution, the thin central portion 11, step portions 13 and 14 (not shown), And the outer frame part 12 is formed.
6—Metal etching is performed on the entire surface of the resist film MR with an etchant.
[0032]
FIG. 5 <Formation of excitation electrode and first extraction electrode>
7-After the above-described steps, an electrode film M1 having a two-layer structure of Cr and Au is deposited on the entire front and back surfaces of the quartz crystal plate 1.
8—Positive type resist film PR is formed on the upper surface thereof.
9- Photolitho technology is used to expose and develop areas excluding the areas corresponding to the excitation electrodes 21 and 22 (not shown) and the first extraction electrodes 23 and 24 (not shown).
10—Metal etching is performed on the electrode film M1 (Au and Cr) in the region with an etchant.
11—Remove the positive type resist film PR.
[0033]
FIG. 6 <Formation of Second Electrode>
12-After the above-described steps, Cr, Ag is applied from the vicinity of the corner portion 151 or 164 (not shown) of the center portion of the crystal diaphragm 1 to the corner portion 121 or 122 (not shown) of the outer frame portion 12. And the electrode film M2 which consists of a three-layer structure of Cr is vapor-deposited, and the 2nd extraction electrodes 25 and 26 are formed. At this time, since the second extraction electrode is also formed on the side end surface of the outer frame portion of the crystal diaphragm, the second extraction electrode can be easily handled as an external connection terminal.
[0034]
As shown in FIGS. 1 to 3, the crystal diaphragm 1 having the center portion 11 and the outer frame portion 12 connected by the step portions 13 and 14 surrounding the center portion 11 is formed by the above steps.
[0035]
(Second Embodiment)
Next, a second embodiment will be described. The present embodiment is a modification of the shape of the central portion 2, and other configurations are the same as those of the first embodiment described above. Accordingly, only differences from the first embodiment will be described here.
[0036]
FIG. 7 is a plan view of the crystal diaphragm 1 according to the second embodiment of the present invention, and FIG. 8 is a bottom view of FIG. FIG. 9 is a cross-sectional view taken along line BB in FIG.
As shown in this figure, the quartz crystal diaphragm 1 according to the present embodiment includes a center portion 11 having an inverted mesa structure, an outer frame portion 12 surrounding the center portion 11, and step portions 13 and 14 connecting the center portion and the outer frame portion. The central extension portions 111 and 112 are formed such that a part of the central portion 11 is flush with one main surface of the central portion and extends to the vicinity of the edge of the outer frame portion 12. It comprises.
[0037]
The central extending portion 111 is formed with step portions 1311 and 1312 continuously from the adjacent portions of the step portions 131 and 132 on the surface side to the step portions 131 and 132, and further near the corner portion 121 of the outer frame portion. Since the step portion 1313 is formed, a part of the central portion extends to the vicinity of the edge of the outer frame portion on the same plane (same depth) as the front side of the central portion.
[0038]
The central extending portion 112 has step portions 1441 and 1442 formed continuously from the adjacent portions of the step portions 141 and 144 on the surface side to the step portions 141 and 144, and in the vicinity of the corner portion 122 of the outer frame portion. By forming the step portion 1443, a part of the central portion extends to the vicinity of the edge of the outer frame portion on the same plane (same depth) as the back side of the central portion.
[0039]
As described above, the crystal diaphragm 1 according to the present embodiment has a rectangular recess that forms an extremely thin main vibration portion (piezoelectric vibration region) on each front and back main surface, and a part of the recess is an end of the outer frame portion. A recess extending to the vicinity of the edge is formed. Such concave portions are formed by a wet etching method.
[0040]
Excitation electrodes 21 and 22 are respectively formed in the central portions of the concave portions on the front and back surfaces. The excitation electrode 21 is extended from the end portion by the first extraction electrode 23 toward a stepped portion 1313 that is an end portion of the central extension portion 112. The excitation electrode 22 is extended from the end portion toward the stepped portion 1443 which is the end portion of the central extension portion 112 by the first extraction electrode 24. These electrodes are formed by a vacuum vapor deposition method or the like, and each electrode material is made of, for example, a material in which gold is laminated on the upper surface of chromium.
[0041]
In addition, the corners 121 and 122 of the outer frame portions on the front and back surfaces are formed with second lead electromotives 25 and 26 that are electrically connected to the excitation electrodes 21 and 22 and constitute external connection terminals. Yes. These second extraction electrodes are formed by separate processes after the excitation electrode and the first extraction electrode are formed. The step of the second extraction electrode 25 from the vicinity of the end of the central extension 111 to the end of the central extension so as to overlap with a part of the first extraction electrode 23 at the top. Formed on the corner 121 of the outer frame 12 via the parts 1311, 1312, 1313, and constitutes an external connection terminal. The step of the second extraction electrode 26 from the vicinity of the end of the central extension 112 to the end of the central extension so as to overlap with a part of the first extraction electrode 24 at the top. Formed on the corner 122 of the outer frame 12 via the parts 1441, 1442 and 1443, and constitutes an external connection terminal. These electrodes are formed by a vacuum vapor deposition method or the like, and each electrode material is made of, for example, a laminate of silver on the upper surface of chromium and chromium on the upper surface. These second extraction electrodes are preferably formed wider than the width of the first extraction electrode.
[0042]
With the above configuration, since the first extraction electrode and the second extraction electrode are configured separately, for example, the second extraction electrode can be formed in a separate process closer to the final process. Thus, it is possible to form an extraction electrode that is less likely to cause disconnection. In addition, since the second extraction electrode is formed to the end portion of the outer frame portion of the piezoelectric vibration device via three step portions having different surface directions close to the end portion of the central extension portion, Even if a part of the second extraction electrode is disconnected at the top (ridge) of the stepped portion, conduction can be ensured at the other stepped portion. In particular, in the present embodiment, a part of the central portion is formed in the central extension portion that extends to the vicinity of the edge of the outer frame portion, so that the step portions having different surface directions are formed on the extraction electrodes. The mechanical contact at the top of the stepped portion hardly occurs and the risk of disconnection can be drastically reduced. Since a part of the central part is formed in the central extension part extending to the vicinity of the edge of the outer frame part, the second electrode is not adversely affected on the excitation electrode formed in the central part. The extraction electrode can be formed.
[0043]
In the above embodiment, an example in which a central extension portion is formed at one corner of a square central portion is taken as an example, but a central extension portion is formed on a side portion of the square central portion. Further, a plurality of center extending portions may be formed, and the first extraction electrode may be extended to the plurality of center extending portions and electrically connected to the second extraction electrode.
[0044]
-Other embodiments-
Each of the embodiments described above describes the formation of a recess (stepped portion) on the front and back main surfaces, but is also applicable to a configuration in which a recess (stepped portion) is formed only on one of the front and back surfaces it can. In addition, an inverted mesa in which a thin central portion, a thick outer frame portion formed so as to surround the central portion, and a step portion connecting the central portion and the outer frame portion are integrally formed by a crystal diaphragm. Although the structure is described, a thick central part, a thin outer frame part formed so as to surround the central part, and a step part connecting the central part and the outer frame part are integrated by a crystal diaphragm. The present invention can also be applied to a formed mesa structure. Further, a stepped portion as a stepped inner side wall may be formed between the central portion and the outer frame portion, and even if stress acts on the outer frame portion, it can be easily relaxed. And local stress concentration can be avoided. Further, in each of the above-described embodiments, the case where a crystal diaphragm is employed as the piezoelectric vibration device has been described. The present invention is not limited to this, and can also be applied to piezoelectric vibration devices made of other piezoelectric materials.
[Brief description of the drawings]
FIG. 1 is a plan view of a crystal diaphragm according to a first embodiment.
FIG. 2 is a bottom view of FIG.
3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 shows a manufacturing method according to the first embodiment.
FIG. 5 shows a manufacturing method according to the first embodiment.
FIG. 6 is a view showing the manufacturing method of the first embodiment.
FIG. 7 is a plan view of a crystal diaphragm according to a second embodiment.
8 is a bottom view of FIG.
9 is a cross-sectional view taken along line BB in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Quartz diaphragm 11 Center part 12 Outer frame part 13, 14 Step part

Claims (3)

A piezoelectric vibration device in which a central portion having a main vibration portion, an outer frame portion formed so as to surround the central portion, and a step portion connecting the central portion and the outer frame portion are integrally formed of a piezoelectric material. There,
An excitation electrode formed at a central portion of the piezoelectric vibration device; a first extraction electrode extending from an end portion of the excitation electrode and formed at least at the central portion and the outer frame portion of the piezoelectric vibration device; Having a second extraction electrode formed in the central part of the device and the outer frame part,
The first extraction electrode extends from the end portion of the excitation electrode toward a specific region where step portions having different surface directions are close to each other,
The second extraction electrode is formed on and electrically connected to the upper surface of the first extraction electrode in the specific region, and passes through each step portion having a different surface direction from the specific region. A piezoelectric vibration device formed on an end portion of an outer frame portion of the piezoelectric vibration device to constitute an external connection terminal.   2. The piezoelectric vibration device according to claim 1, wherein the central portion is formed in a polygonal shape, and the specific region where the step portions having different surface directions are close to each other is a corner portion of the central portion. A piezoelectric vibration device in which a central portion including a main vibration portion, an outer frame portion formed so as to surround the central portion, and a step portion connecting the central portion and the outer frame portion are integrally formed of a piezoelectric material. There,
A central extension part is formed in which a part of the central part extends to the vicinity of the edge of the outer frame part,
An excitation electrode formed at a central portion of the piezoelectric vibration device; a first extraction electrode extending from an end portion of the excitation electrode; and formed at least at the central portion and the central extension portion of the piezoelectric vibration device ; A central extension portion of the vibration device and a second extraction electrode formed on the outer frame portion;
The first extraction electrode extends from an end portion of the excitation electrode toward a specific region of the central extension portion,
The second extraction electrode is formed on and electrically connected to the upper surface of the first extraction electrode in the specific region, and passes through each step portion having a different surface direction from the specific region. A piezoelectric vibration device formed on an end portion of an outer frame portion of the piezoelectric vibration device to constitute an external connection terminal.

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