JP2019153973A - Tuning fork type piezoelectric vibrating piece - Google Patents

Abstract

To provide a tuning fork type piezoelectric vibrating piece having good characteristics with a vibrating arm improved in rigidity even if the tuning-fork type piezoelectric vibrating piece becomes ultra-small and a tuning fork type piezoelectric vibrator using the same.SOLUTION: A tuning fork type piezoelectric vibrating piece 2 includes: a base 20; vibrating arms 21, 22, protruding from the base, on which excitation electrodes 25, 26 are formed; and long holes G1, G2 formed on a main surface of the vibrating arms. The long holes have a longitudinal direction along a protruding direction of the vibrating arm and a width direction along a direction orthogonal to the protruding direction of the vibrating arm. Inside the long holes, a part of the excitation electrodes is formed and a bridge portion which is not formed in parallel with any of the longitudinal direction and the width direction is formed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a piezoelectric vibrating piece having a tuning fork shape and a tuning fork type piezoelectric vibrator using the piezoelectric vibrating piece.

  Piezoelectric vibrators such as tuning-fork type piezoelectric vibrators are used in various electronic devices as reference clock sources. For example, a surface-mounted tuning fork type piezoelectric vibrator includes a base and a pair of vibrating arms protruding in the same direction from one end side of the base, and the pair of vibrating arms has excitation electrodes for driving the vibrating arms, etc. The tuning-fork type piezoelectric vibrating piece with the formed is accommodated in the recess of the insulating container. The other end side of the base of the tuning fork type piezoelectric vibrating piece is conductively bonded via an electrically conductive bonding material on an electrode pad formed on the inner bottom surface of the concave portion of the container, and a flat plate is formed on the opening end of the concave portion of the container. It is the structure where the lid | cover of the shape was joined (patent document 1).

  In recent years, with the improvement in performance and miniaturization of communication devices, tuning fork-type piezoelectric vibrating reeds are required to be further downsized and the quality of their characteristics improved. On the other hand, in order to suppress the increase in CI due to the miniaturization of the tuning fork type piezoelectric vibrating piece, a hole is formed in the main surface of the vibrating arm, and an excitation electrode is formed in the hole to improve the electric field efficiency. It is indispensable to raise (Patent Document 2).

  In addition, when the tuning fork type piezoelectric vibrating piece is downsized, the vibration fork of the tuning fork type piezoelectric vibrating piece is also reduced in accordance with the downsizing. In particular, the length of the vibrating fork is relatively short, so that the reference clock source It has become difficult to cope with relatively low frequency applications (particularly 32.768 KHz used as a clock source for a clock or the like). On the other hand, each vibrating rod of the tuning-fork type piezoelectric vibrating piece needs to have a weight part wider than the vibrating part at the tip of the vibrating part, separately from the vibrating part having the excitation electrode. (Patent Document 1).

WO2014 / 208251 JP 2003-60482

  As described above, as the tuning fork type piezoelectric vibrating piece is further reduced in size, the width of the bank formed between the end of the vibrating rod and the hole becomes narrower than before, and the rigidity of the vibrating rod is reduced. . In particular, in a tuning fork type piezoelectric vibrating piece having a weight portion, the rigidity changes suddenly at the connecting portion between the vibrating portion and the weight portion, so that the strength of the vibrating rod is reduced and the risk of a broken vibrating arm is increased. was there.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a tuning fork type piezoelectric vibrating piece having good characteristics by increasing the rigidity of the vibrating rod even when the tuning fork type piezoelectric vibrating piece is miniaturized. To do.

  In order to achieve the above object, an invention according to claim 1 includes a base, a vibrating arm protruding from the base and having an excitation electrode formed therein, and a long hole formed in a main surface of the vibrating arm. The hole has a longitudinal direction along the protruding direction of the vibrating arm and a width direction along a direction orthogonal to the protruding direction of the vibrating arm, and the excitation electrode is disposed inside the elongated hole. Is formed, and a bridging portion that is not formed in parallel in either the longitudinal direction or the width direction is formed.

  According to the above invention, by forming the cross-linked portion in the oblique direction that is not formed in parallel with either the longitudinal direction or the width direction inside the long hole, the remaining portion of the long hole where the cross-linked portion is not formed The rigidity in the width direction of the vibrating rod can be increased without greatly reducing the volume as a whole. In addition, by using a long hole, the configuration is advantageous for lowering the frequency.

  This is because if the bridging portion inside the long hole is configured along the longitudinal direction, the rigidity in the width direction of the vibrating rod tends to be insufficient, and the volume of the long hole is reduced. In addition, if the bridging portion inside the elongated hole is configured along the width direction, not only the configuration of the vibrating fork type piezoelectric vibrating piece that is excited when the vibrating rod swings in the lateral direction can be easily prevented, but also the vibration rod In order to increase the rigidity in the width direction, it is necessary to increase the number of bridging portions, which tends to reduce the volume of the long holes.

  Therefore, as in the present invention, by forming an oblique bridge portion that is not formed parallel to either the longitudinal direction or the width direction, it is difficult to prevent bending vibration of the tuning fork type piezoelectric vibrating piece, and the strength in the width direction is reduced. Can be reinforced with fewer cross-linked portions. The function of the cross-linking portion in the diagonal direction as a brace increases. Further, since the volume of the long hole remaining portion where the bridging portion is not formed is not greatly reduced as a whole, the area of the excitation electrode formed inside the long hole remaining portion is not greatly reduced, and the tuning fork type piezoelectric vibrating piece The field efficiency at the time of excitation is not reduced. As a result, it is possible to suppress an increase in CI to ensure good characteristics, and to reliably increase the rigidity in the width direction of the vibrating rod.

  Further, in addition to the above-described configuration, a pair of vibrating arms that protrude in the same direction from one end side of the base portion is provided, and a long hole is formed in each main surface of the pair of vibrating arms, and the inside of the long hole. A bridging portion is formed, and the elongated hole and the bridging portion formed in each of the vibrating rods may be formed symmetrically with respect to a virtual center line between the pair of vibrating arms. .

  According to the above invention, in addition to the above-described effects, the long holes and the bridging portions of the pair of vibrating arms are formed symmetrically with respect to the virtual center line between the pair of vibrating arms. As a result, the electric field applied to each vibration rod through the excitation electrode is uniformly balanced by the mutual vibration rods, and does not promote unnecessary vibration.

Further, in addition to the above-described configuration, a long hole remaining portion in which the bridge portion is not formed is formed inside the long hole, and a shape other than the long hole remaining portion at both ends in the longitudinal direction of the long hole is formed. May be formed in an isosceles triangular shape or an isosceles trapezoidal shape.

  According to the above invention, in addition to the above-described effects, the shape of the long holes other than the long hole remaining portions at both ends in the longitudinal direction is formed into an isosceles triangle shape or an isosceles trapezoidal shape. The length of the bridging part in contact with the remaining part is the same size, the rigidity balance in the width direction of the vibration rod is maintained, and the electric field applied to the vibration rod is evenly balanced in the width direction of the vibration rod, promoting unnecessary vibration There is nothing to do.

  In addition to the above-described configuration, a wide weight portion may be formed at the protruding end portion of the vibrating arm.

  According to the above-described invention, in addition to the above-described effects, the wide weight portion of the protruding end portion of the vibrating arm can reduce the frequency associated with downsizing of the tuning-fork type piezoelectric vibrating piece, and this weight portion exists. It can cope with further lack of rigidity due to. As a result, there is no risk of vibration arm breakage.

  Further, the tuning fork type piezoelectric vibrating piece described above can be applied to a tuning fork type piezoelectric vibrator that is mounted and accommodated inside a container and is hermetically sealed. As obtained.

  As described above, according to the present invention, it is possible to provide a tuning-fork type piezoelectric vibrating piece having good characteristics by increasing the rigidity of the vibrating rod even when the tuning-fork type piezoelectric vibrating piece becomes ultra-small.

1 is a schematic cross-sectional view of a tuning fork type crystal resonator according to an embodiment of the present invention. FIG. 3 is a schematic plan view of one main surface side of a tuning fork type crystal vibrating piece according to an embodiment of the present invention. FIG. 3 is a plan view of the other main surface side of the tuning-fork type crystal vibrating piece of FIG. 2. FIG. 6 is a schematic plan view of one main surface side of a tuning fork type crystal vibrating piece according to another embodiment of the present invention.

  Hereinafter, as an embodiment of the present invention, a tuning fork type crystal resonator (tuning fork type piezoelectric resonator) using a tuning fork type crystal resonator element (tuning fork type piezoelectric resonator element) will be described as an example with reference to the drawings. The tuning fork type crystal resonator (hereinafter abbreviated as “crystal resonator”) in the present embodiment is a surface-mount type crystal resonator having a substantially rectangular parallelepiped package structure. In the present embodiment, the external dimensions in plan view are, for example, 1.6 mm in length and 1.0 mm in width. The external dimensions of the crystal resonator in plan view are not limited to the dimensions, but are suitable for an ultra-small crystal resonator having the same size or less.

  As shown in FIG. 1, a crystal resonator 1 according to an embodiment of the present invention includes a container 3 made of an insulating material having a recess 5, a tuning fork-type crystal vibrating piece 2 (hereinafter abbreviated as a crystal vibrating piece 2), a recess A flat lid 4 for sealing 5 is a main constituent member. In FIG. 1, the description of various electrodes formed on the quartz crystal vibrating piece is omitted. After the quartz crystal vibrating piece 2 is accommodated in the recess 5 of the container 3, the lid 4 is joined to the opening end of the container 3 so as to cover the recess 5, and is hermetically sealed. Here, the container 3 and the lid 4 are joined via a sealing material (not shown).

  The container 3 is a box-shaped body made of an insulating material mainly composed of ceramic such as alumina, and is formed by laminating two ceramic green sheets and integrally firing them (see FIG. 1). The container 3 has a concave portion 5 having a rectangular shape in plan view inside the frame-shaped bank portion 30. A sealing material (not shown) is formed in a frame shape in plan view on the upper surface of the bank portion 30, and the bonding material corresponds to the outer peripheral portion of the lid 4.

  On one short side of the inner bottom surface 301 of the recess 5, two electrode pads 6 and 7 (only one is shown in FIG. 1) conductively joined to the quartz crystal vibrating piece 2 are arranged in parallel with a gap therebetween. Is formed. The two electrode pads 6 and 7 are two of the four external connection terminals 8 (only two are shown in FIG. 1) provided at the four corners of the outer bottom surface 302 of the container 3 through internal wiring and vias (not shown). Is electrically connected to two terminals. These two electrode pads 6 and 7 have different polarities.

  In the present embodiment, the two electrode pads 6 and 7 are formed by laminating gold on the upper surface of the tungsten metallized layer using a technique such as plating. As the metallized layer, molybdenum may be used instead of tungsten.

  The tungsten portions of the electrode pads 6 and 7 are overlaid in two steps in terms of the minimum unit thickness of metallization. In this embodiment, since the container 3 has a two-layer structure in order to reduce the thickness of the crystal resonator, a step portion cannot be formed on the inner bottom surface 301 of the recess 5. This is to ensure a certain gap between the lower surface (the surface facing the inner bottom surface 301) of the quartz crystal vibrating piece and the inner bottom surface 301 in the later state.

  The lid 4 is a metallic lid body having a rectangular shape in a plan view using Kovar as a base, and nickel plating layers are formed on the front and back surfaces of the lid. Further, a brazing material made of metal is formed on the nickel plating layer over the entire surface of the lid 4 on the side of the joint surface with the container. In this embodiment, silver brazing is used as the brazing material.

  Next, the quartz crystal resonator element according to this embodiment will be described with reference to FIGS. For convenience of explanation, of the two main surfaces (2a, 2b) facing the crystal resonator element 2, the main surface facing the electrode pads 6, 7 when mounted on the container is defined as a back surface 2b. The main surface on the opposite side opposite to the surface 2a will be described as the surface 2a. FIG. 2 is a plan view seen from the front surface side (2a) of the quartz crystal vibrating piece, and FIG. 3 is a plan view seen from the back surface side (2b) of the quartz crystal vibrating piece.

  As shown in FIGS. 2 and 3, the quartz crystal vibrating piece 2 has a tuning fork shape, and includes a base portion 20, a pair of vibrating arms 21 and 22 protruding in the same direction from one end side 201 of the base portion 20, and the other end side of the base portion. The projection portion 24 protrudes from one side surface 202 toward one side in the width direction of the base portion 20 (the size of the base portion in the axial direction indicated by the symbol X in FIGS. 2 and 3).

  A wide portion 23 that is wider than the arm width of the vibrating arms 21 and 22 (the dimension of the arm in a direction orthogonal to the protruding direction of the vibrating arms) is provided on the distal end side of each of the pair of vibrating arms 21 and 22. 23 (weight portion) is formed. The wide portions 23 and 23 are formed integrally with the tip portions of the vibrating arms 21 and 22 through widened portions (reference numerals omitted) that gradually widen in the protruding direction of the vibrating arms. The widened portion and the wide portion are formed integrally with the vibrating arm. In addition, each corner part of the front end side 211,221 of each wide part 23,23 is processed into the chamfering shape (C surface shape). The vibrating arms 21 and 22, the widened portion, and the wide portions 23 and 23 have a pair of side surfaces (reference numerals omitted) facing the pair of opposed main surfaces 2 a and 2 b.

  Long holes are formed in the front and back main surfaces of each of the pair of vibrating arms 21 and 22 for the purpose of further reducing the equivalent series resistance value (hereinafter referred to as CI value). More specifically, a long hole G1 is formed on the front and back main surfaces of the vibration rod 21, and a long hole G2 is formed on the front and back main surfaces of the vibration rod 22. The long holes G1 and G2 are formed so as to penetrate the thickness direction of the front and back main surfaces of each of the pair of vibrating arms 21 and 22, one end side thereof is extended to the region of the one end side 201 of the base portion 20, and the other end The side is formed on the base side of the vibrating arm with respect to the boundary between the vibrating arm and the widened portion. The long holes G1 and G2 are perpendicular to the longitudinal direction along the direction in which the vibrating arms 21 and 22 project (the axial direction indicated by the symbol Y in FIGS. 2 and 3) and the direction in which the vibrating arms 21 and 22 project. And a width direction (an axial direction indicated by a symbol X in FIGS. 2 and 3). In addition, the area | region of the vibration rod in which the long holes G1 and G2 exist comprises the vibration part.

  Inside the long holes G1 and G2 formed on the front and back main surfaces of the vibrating arms 21 and 22, diagonally formed in parallel with neither the longitudinal direction (Y-axis direction) nor the width direction (X-axis direction) Directional bridging portions G11 to G23 are formed. Hereinafter, the internal structure of the long holes G1 and G2 on the front and back main surfaces of the vibrating arms 21 and 22 will be described in more detail.

  In the long hole G1 of the vibrating arm 21, three bridging portions G11, G12, and G13 inclined at about 30 ° or 150 ° with respect to the longitudinal direction (the Y-axis direction and the protruding direction of the vibrating arm) vibrate. It is formed in a state adjacent to each other from the tip side of the ridge. In FIG. 2, for example, the bridging portion G11 is a parallelogram having a constant width and is inclined at 150 ° in the longitudinal direction, the bridging portion G12 is a parallelogram having a constant width and is inclined at 30 ° in the longitudinal direction, and the bridging portion G13 is constant in width. The parallelogram is inclined at 150 ° in the longitudinal direction, and the ends of the bridge portions are in contact with the ends of the bridge portions adjacent to each other.

  The tilt angle is an example and is not particularly limited. However, the tilt angle is tilted at an angle smaller than about 45 ° with respect to the longitudinal direction (Y-axis direction / projection direction of the vibrating arm) or 135. By inclining at an angle larger than 0 °, it is difficult to prevent bending vibration of the quartz crystal vibrating piece 2 and the strength in the width direction can be reinforced with less bridging portions. Furthermore, the shape of each bridging portion is also an example and is not particularly limited. However, by using a parallelogram shape having a constant width, the rigidity balance in the width direction of the vibration rod is maintained, and the vibration rod 21 is applied. The electric field is also uniformly balanced in the width direction of the vibrating rod and does not promote unnecessary vibration. In addition, the number of each cross-linking portion is also an example and is not particularly limited, and can be adjusted according to the size of the long hole G1.

  In addition, four long hole remaining portions G14, G15, G16, and G17 are formed from the tip side of the vibrating rod except for the three bridging portions G11, G12, and G13 in the long hole G1 of the vibrating arm 21. . And, the long hole remaining portions G15 and G16 other than both ends in the longitudinal direction of the long hole G1 are formed in an isosceles triangle shape.

  In addition, since the shape of the long hole remaining portions G15 and G16 formed at the central portion of the vibrating rod depends on the arrangement of the bridge portions, the end portions of the bridge portions are adjacent to each other. When configured in a state of being separated at the end, the shape can be an isosceles trapezoid rather than an isosceles triangle. Thus, by forming the shape of the long hole remaining portions G15 and G16 formed in the center portion of the vibrating rod into an isosceles triangle shape or an isosceles trapezoidal shape, the bridging portions G11, G12, The length of G13 becomes the same dimension, the rigidity balance in the width direction of the vibrating rod is maintained, and the electric field applied to the vibrating rod 21 is also uniformly balanced in the width direction of the vibrating rod, thereby promoting unnecessary vibration. Absent.

  In the long hole G2 of the vibrating arm 22, three bridging portions G21, G22, and G23 inclined at about 30 ° or 150 ° with respect to the longitudinal direction (the Y-axis direction and the protruding direction of the vibrating arm) vibrate. It is formed in a state adjacent to each other from the tip side of the ridge. In FIG. 2, for example, the bridging portion G21 is a parallelogram having a constant width and is inclined at 30 ° in the longitudinal direction, the bridging portion G22 is a parallelogram having a constant width and is inclined at 150 ° in the longitudinal direction, and the bridging portion G23 is constant in width. The parallelograms are inclined at 30 ° in the longitudinal direction, and the ends of the bridge portions are in contact with the ends of the bridge portions adjacent to each other.

  The tilt angle is an example and is not particularly limited. However, the tilt angle is tilted at an angle smaller than about 45 ° with respect to the longitudinal direction (Y-axis direction / projection direction of the vibrating arm) or 135. By inclining at an angle larger than 0 °, it is difficult to prevent bending vibration of the quartz crystal vibrating piece 2 and the strength in the width direction can be reinforced with less bridging portions. Furthermore, the shape of each bridging portion is an example and is not particularly limited. However, by making a parallelogram with a constant width, the rigidity balance in the width direction of the vibrating rod is maintained, and the vibrating rod 22 is applied. The electric field is also uniformly balanced in the width direction of the vibrating rod and does not promote unnecessary vibration. In addition, the number of each cross-linking portion is also an example and is not particularly limited, and can be adjusted according to the size of the long hole G2.

  In addition, four long hole remaining portions G24, G25, G26, and G27 are formed inside the long hole G2 of the vibrating arm 22 from the tip side of the vibrating rod except for the three bridging portions G21, G22, and G23. . The long hole remaining portions G25 and G26 other than the both ends in the longitudinal direction of the long hole G2 are formed in an isosceles triangle shape.

  Since the shape of the long hole remaining portions G25 and G26 formed in the center portion of the vibrating rod depends on the arrangement of the bridge portions, the end portions of the bridge portions are adjacent to each other. When configured in a state of being separated at the end, the shape can be an isosceles trapezoid rather than an isosceles triangle. Thus, by forming the shape of the long hole remaining portions G25 and G26 formed in the center portion of the vibration rod into an isosceles triangle shape or an isosceles trapezoidal shape, the bridging portions G21, G22, which are in contact with these long hole remaining portions, The length of G23 becomes the same dimension, the rigidity balance in the width direction of the vibrating rod is maintained, and the electric field applied to the vibrating rod 22 is also uniformly balanced in the width direction of the vibrating rod, thereby promoting unnecessary vibration. Absent.

  Here, the long hole G1 and the long hole G2 formed in the vibrating rod 21 and the vibrating rod 22, the bridging portions G11, G12, and G13, the bridging portions G21, G22, and G23, and the long hole remaining portions G14, G15, G16, and G17 are long. The hole remaining portions G24, G25, G26, and G27 are formed symmetrically with respect to the virtual center line CL between the vibrating arm 21 and the vibrating rod 22. As a result, the electric field applied to the vibrating bars 21 and 22 via the excitation electrodes 25 and 26 described later is uniformly balanced by the vibrating bars and does not promote unnecessary vibration.

  In the present embodiment, in each bridging portion formed on the front and back surfaces of each vibrating rod, the wet etching described later is not performed, and each slot remaining portion of each vibrating rod is not formed (hereinafter, However, as shown in FIG. 4, the thickness may be thinner than that of the other region of the vibration rod.

  The base portion 20 is formed with a reduced width portion 203 in which the width of the base portion is narrower on the other end side 202 side than on the one end side 201 side. The protruding portion 24 described above is formed on one side surface of the reduced width portion 203. The projecting portion 24 and the base portion 20 form an alphabet “L” -shaped portion bent at a right angle in a plan view. The tuning fork type crystal vibrating piece is not limited to the shape in the present embodiment. For example, the protruding portion may have a shape protruding not only from one side surface of the base portion but also from the other side surface of the base portion (side surface facing the one side surface), that is, a shape in which the protruding portions protrude from both outer sides of the base portion. Alternatively, the projecting portion may have a bilaterally symmetric shape that projects in parallel to each other by changing the direction in the projecting direction of the vibrating arm after projecting outward from the base. Moreover, the shape in which the protrusion part is not formed in the base may be sufficient.

  A large number of the above-described quartz vibrating piece external shapes and long holes are simultaneously formed from a single quartz wafer using a photolithographic technique and wet etching.

  The quartz crystal resonator element 2 includes a first excitation electrode 25 and a second excitation electrode 26 configured with different potentials, and a lead electrode (described later) from each of the first excitation electrode 25 and the second excitation electrode 26. The extraction electrodes 27 and 28 extracted via the line are formed.

  In addition, a part of the first and second excitation electrodes 25 and 26 formed on the front and back main surfaces of the pair of vibrating arms 21 and 22 is entirely inside the long holes G1 and G2 of the pair of vibrating arms 21 and 22. Is formed. By forming the long hole, the electric field efficiency of the pair of vibrating arms 21 and 22 is increased even when the quartz vibrating piece is downsized, and a good CI value can be obtained. Note that only the first and second excitation electrodes may be formed only in a partial region inside the long holes G1 and G2 of the pair of vibrating arms.

  The first excitation electrode 25 is formed on the front and back main surfaces of one vibrating arm 21 and on the outer side surface and inner side surface of the other vibrating arm 22 via a lead electrode (reference numeral omitted). Similarly, the second excitation electrode 26 is formed on the front and back main surfaces of the other vibrating arm 22 and on the outer side surface and inner side surface of one vibrating arm 21 via a routing electrode (not shown).

  The extraction electrodes 27 and 28 are formed on the base 20 and the protrusion 24 (only the back surface 2b). With the extraction electrode 27 formed on the base portion 20, the first excitation electrode 25 formed on each of the outer surface and the inner surface of the other vibrating arm 22 and the routing electrode (reference numeral omitted) A first excitation electrode 25 formed on the front and back main surfaces of the vibrating arm 21 is connected. Similarly, the extraction electrode 28 formed on the base 20 passes through the second excitation electrode 26 formed on each of the outer side surface and the inner side surface of one vibrating arm 21 and the routing electrode (not shown). The second vibrating electrode 22 is connected to a second excitation electrode 26 formed on the front and back main surfaces of the other vibrating arm 22.

  The lead electrodes 27 and 28 are drawn from the one end side 201 of the base portion 20 to the reduced width portion 203 on the surface 2a of the quartz crystal vibrating piece. On the other hand, the back surface 2 b of the quartz crystal vibrating piece is drawn out to the other end side 202 and the tip end side of the protruding portion 24. As shown in FIG. 3, the region on the other end side 202 of the base portion 20 and the region on the tip end side of the projecting portion 24 on the back surface 2 b of the quartz crystal vibrating piece are respectively connected to the electrode pads 6 and 7 of the container 3. The connection electrodes 271 and 281 are connected to each other.

  As shown in FIG. 3, conductive bonding materials S and S are formed on the upper surfaces of the two connection electrodes 271 and 281, respectively. In the present embodiment, the bonding material S is a plating bump formed by an electrolytic plating method. The conductive bonding between the crystal vibrating piece 2 and the electrode pads 6 and 7 is performed by the FCB method (Flip Chip Bonding).

  The above-described routing electrodes are formed on all of the pair of main surfaces and the pair of side surfaces constituting the wide portions 23, 23, respectively. In the present embodiment, the routing electrode is formed on the entire circumference of the wide portion 23 and the entire circumference (a pair of main surfaces and a pair of side surfaces) of the portion near the widened portion of the vibrating arms 21 and 22.

  In the first and second excitation electrodes 25 and 26, the extraction electrodes 27 and 28, and the routing electrodes (not shown) described above, a chromium (Cr) layer is formed on a quartz base material, and a gold layer is formed on the chromium layer. It has a layer structure in which (Au) layers are stacked. The layer configuration of the various electrodes is not limited to a layer configuration in which a gold layer is formed on a chromium layer, but may be other layer configurations.

  The first and second excitation electrodes, the extraction electrode, and the drawing electrode are formed on the entire main surface of the quartz wafer by vacuum deposition or sputtering, and then simultaneously formed into a desired pattern by photolithography and metal etching. Molded.

  As shown in FIG. 2, in the embodiment of the present invention, the frequency adjusting metal film W (frequency adjusting weight) is formed on only one main surface (surface 2 a) of the surfaces constituting the wide portion 23. By reducing the mass of the frequency adjusting metal film W by irradiation with a beam such as a laser beam or an ion beam, the frequency of the quartz crystal vibrating piece 2 is finely adjusted. Note that the frequency adjusting metal film W is formed so that the area in plan view is slightly smaller than the routing electrodes on the main surfaces of the wide portions 23 and 23.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  It can be applied to mass production of tuning fork type piezoelectric vibrating pieces and tuning fork type piezoelectric vibrators.

DESCRIPTION OF SYMBOLS 1 Tuning fork type crystal resonator 2 Tuning fork type crystal vibrating piece 20 Base part 21, 22 Vibrating arm 23 Wide part 24 Projection part 25, 26 Excitation electrode 27, 28 Extraction electrode 3 Container G1, G2 Long hole G11, G12, G13 Bridging part G21 , G22, G23 Cross-linking part

Claims (1)

base,
A vibrating arm protruding from the base and having an excitation electrode;
A long hole formed in the main surface of the vibrating arm,
With
The long hole has a longitudinal direction along a direction in which the vibrating arm protrudes and a width direction along a direction orthogonal to the direction in which the vibrating arm protrudes,
Inside the long hole, a part of the excitation electrode is formed, and a bridging portion that is not formed in parallel in either the longitudinal direction or the width direction is formed.
A tuning-fork type piezoelectric vibrating piece characterized by the above.

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