JP2017060130A - Tuning-fork type crystal vibration element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of improving an electric characteristic by, for example, reducing a spurious component in a tuning fork element having a support arm part.SOLUTION: A tuning fork element 10 comprises a base part 11, vibration arm parts 12a and 12b, and a support arm part 13. The base part 11 has a substantially square shape in planar view, formed by a first side 111 and a second side 112 facing to each other and a third side 113 and a fourth side 114 facing to each other. The vibration arm parts 12a and 12b are extended to the same direction from the first side 111. The support arm part 13 is provided on the third side 113 closer to the second side 112 so as to be extended from the second side 112 to a short direction of the vibration arm part 12a and further extended from a tip thereof to a longitudinal direction of the vibration arm part 12a. The tuning fork element 10 further comprises shoulder parts 14a and 14b. In the shoulder parts 14a and 14b, the third side 113 and the fourth side 114 are extended from the root of the vibration arm parts 12a and 12b to the short direction of the vibration arm parts 12a and 12b.SELECTED DRAWING: Figure 1

Description

  In the present invention, a tuning fork type crystal vibrating element (hereinafter, abbreviated as “tuning fork element”) used for a reference signal source and a clock signal source will be described.

  FIG. 7A is a schematic plan view showing a tuning fork element according to Related Technique 1. FIG. FIG. 7B is a schematic plan view showing a tuning fork element according to Related Technique 2. Hereinafter, description will be given based on these drawings.

  The tuning fork element 210 of Related Art 1 includes a base 211 and vibrating arm portions 212a and 212b, and is sealed by an element mounting member and a lid member (not shown). The base 211 has a substantially rectangular shape in plan view, and the lower surface side is fixed to the element mounting member with a conductive adhesive. That is, the tuning fork element 210 is fixed to the element mounting member in a cantilever shape. For this reason, when an impact is applied to the tuning fork element 210, the tips of the vibrating arm portions 212a and 212b may come into contact with the element mounting member or the lid member, causing a malfunction of the tuning fork element 210.

  A tuning fork element 310 of Related Technology 2 that solves the problem of Related Technology 1 is known (see Patent Document 1). The tuning fork element 310 includes a base 311, vibrating arm portions 312 a and 312 b, and a support arm portion 313, and is different from the related technique 1 in that the support arm portion 313 is provided. The support arm portion 313 has a shape extending from the base portion 311 in the short direction of the vibrating arm portion 312a and further extending from the distal end thereof in the longitudinal direction of the vibrating arm portion 312a. For example, by fixing the tip side of the support arm 313 to the element mounting member with a conductive adhesive, the tuning fork element 310 can be fixed substantially in the form of a double-supported beam, so that the impact resistance of the tuning fork element 310 is improved.

Japanese Patent No. 4049017

  However, the tuning fork element 310 of the related technique 2 has a problem that the electrical characteristics are inferior to those of the related technique 1, such as an increase in spurious components, an oscillation frequency shift, and an increase in equivalent series resistance value.

  Accordingly, an object of the present invention is to provide a technique capable of improving electrical characteristics such as reduction of spurious components in a tuning fork element having a support arm portion.

  The inventor conducted research to solve the problem that the electrical characteristics such as spurious components are inferior in the tuning fork element 310 of the related art 2, and as a result, obtained the following knowledge.

  When the vibrating arm portions 312a and 312b undergo flexural vibration, a part of the vibrating arm portions 312a and 312b leaks to the support arm portion 313 side. As a result, the support arm portion 313 vibrates, and the vibration returns to the vibrating arm portions 312a and 312b. As a result, the electrical characteristics of the tuning fork element 310 are adversely affected, such as an increase in spurious components due to the piezoelectric effect.

The present invention has been made based on this finding,
A substantially quadrangular base portion in plan view composed of first and second sides facing each other and third and fourth sides facing each other;
A pair of vibrating arms extending in the same direction from the first side;
Provided on at least one of the second side of the third side and the second side of the fourth side, extends from the second side in the lateral direction of the vibrating arm portion, and further from the tip thereof A support arm extending in the longitudinal direction of the vibrating arm;
A tuning fork element comprising:
A shoulder portion in which at least one of the third side and the four sides facing the support arm portion extends in a short direction of the vibrating arm portion from a root of the vibrating arm portion,
It is further provided with the feature.

  According to the present invention, by providing the shoulder portion extending from the root of the vibrating arm portion in the short direction of the vibrating arm portion, vibration transmitted from the vibrating arm portion to the supporting arm portion and from the supporting arm portion to the vibrating arm portion. Since the transmitted vibration can be damped at the shoulder, electrical characteristics such as reduction of spurious components can be improved.

FIG. 3 is a plan view showing a tuning fork element according to the first embodiment. 2A is a cross-sectional view taken along line IIa-IIa in FIG. 1, and FIG. 2B is a schematic cross-sectional view showing a state where the tuning fork element in FIG. 1 is mounted on an element mounting member. FIG. 5 is a schematic plan view showing a modification of the first side to the fourth side of the tuning fork element of FIG. 1. FIG. 3 is a schematic plan view for explaining the effect of the first embodiment. FIGS. 3A, 3C, and 3E show related technology 2 as a comparative example, and FIGS. 3B, 3D, and 3F show FIGS. Embodiment 1 is shown. FIG. 4A is a schematic plan view showing another embodiment, FIG. 4A shows the second embodiment, and FIG. 4B shows the third embodiment. FIG. 5A is a schematic plan view showing another embodiment, FIG. 5A shows the fourth embodiment, and FIG. 5B shows the fifth embodiment. It is a schematic plan view which shows other embodiment, FIG. 6 [A] shows Embodiment 6, FIG. 6 [B] shows Embodiment 7. FIG. FIG. 7A is a schematic plan view showing a related technique, FIG. 7A shows the related technique 1, and FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the accompanying drawings. In the present specification and drawings, the same reference numerals are used for substantially the same components. Moreover, since the shape drawn on drawing is drawn so that those skilled in the art can understand easily, it does not necessarily correspond with an actual dimension and ratio.

  FIG. 1 is a plan view showing a tuning fork element according to the first embodiment. 2A is a cross-sectional view taken along line IIa-IIa in FIG. FIG. 2B is a schematic cross-sectional view showing a state where the tuning fork element of FIG. 1 is mounted on an element mounting member. FIG. 2C is a schematic plan view showing a modification of the first to fourth sides of the tuning fork element of FIG. Hereinafter, description will be given based on these drawings.

  As shown in FIGS. 1 and 2A, the tuning fork element 10 according to the first embodiment includes a base 11, a pair of vibrating arms 12a and 12b, and a support arm 13. The base 11 has a substantially quadrangular shape in plan view, which includes a first side 111 and a second side 112 facing each other, and a third side 113 and a fourth side 114 facing each other. The pair of vibrating arm portions 12 a and 12 b extend from the first side 111 in the same direction. The support arm portion 13 is provided on at least one of the second side 112 side of the third side 113 and the second side 112 side of the fourth side 114, and the short side direction of the vibrating arm portions 12a and 12b from the second side 112 side. And extending further in the longitudinal direction of the vibrating arms 12a and 12b from the tip. In the first embodiment, the support arm portion 13 is provided only on the second side 112 side of the third side 113. The tuning fork element 10 further includes a pair of shoulder portions 14a and 14b. The pair of shoulder portions 14a and 14b has a third side 113 and a fourth side 114 extending from the roots of the vibrating arm portions 12a and 12b in the short direction of the vibrating arm portions 12a and 12b, respectively.

  The vibrating arm portions 12a and 12b are extended from the base portion 11 in the same direction, and groove portions 15a and 15b are provided along the extending direction. At the tips of the vibrating arm portions 12a and 12b, weight portions 16a and 16b for frequency adjustment are provided, respectively. The base portion 11, the vibrating arm portions 12 a and 12 b, the support arm portion 13, and the weight portions 16 a and 16 b are made of a crystal vibrating piece 19. The tuning fork element 10 includes pad electrodes 21a and 21b, excitation electrodes 22a and 22b, frequency adjusting metal films 23a and 23b, and wiring patterns 24a and 24b in addition to the crystal vibrating piece 19.

  Next, the configuration of the tuning fork element 10 will be described in more detail.

  The base 11 is a flat plate having a substantially rectangular shape in a plan view (a region surrounded by a solid line and a broken line). The quartz crystal vibrating piece 19 has a tuning fork shape in which the base 11, the vibrating arms 12a and 12b, the supporting arm 13 and the weights 16a and 16b are integrated, and is formed by a film forming technique, a photolithography technique, and a wet etching technique. Manufactured.

  The groove portions 15a and 15b vibrate from the boundary portion with the base 11 toward the tip of the vibrating arm portions 12a and 12b, two grooves on the front and rear surfaces of the vibrating arm portion 12a and two grooves on the front and rear surfaces of the vibrating arm portion 12b. It is provided with a predetermined length in parallel with the longitudinal direction of the arms 12a, 12b. In the first embodiment, two grooves 15a and 15b are provided on the front and back surfaces of the vibrating arm 12a and two grooves on the front and back surfaces of the vibrating arm 12b. However, the number of the grooves 15a and 15b is not limited. For example, one may be provided on the front and back surfaces of the vibrating arm portion 12a and one on each of the front and back surfaces of the vibrating arm portion 12b, or may be provided on only one side of the front and back surfaces. An etching suppression pattern may be provided in the grooves 15a and 15b so as not to penetrate during the wet etching.

  The vibrating arm 12a is provided with excitation electrodes 22a on both side surfaces so that the planes facing each other across the crystal have the same polarity, and excitation electrodes 22b are provided inside the groove portions 15a on the front and back surfaces. Similarly, the vibrating arm portion 12b is provided with excitation electrodes 22b on both side surfaces so that the planes facing each other across the crystal have the same polarity, and the excitation electrode 22a is provided inside the groove portion 15b on the front and back surfaces. . Therefore, in the vibrating arm portion 12a, the excitation electrode 22a provided on both sides and the excitation electrode 22b provided in the groove 15a have different polarities, and in the vibrating arm portion 12b, the excitation electrode 22b provided on both sides. And the excitation electrode 22a provided in the groove 15b have different polarities.

  The support arm portion 13 is provided with pad electrodes 21a and 21b, the support arm portion 13 and the base portion 11 are provided with wiring patterns 24a and 24b, and the weight portions 16a and 16b are provided with frequency adjusting metal films 23a and 23b. It is done. The wiring pattern 24a electrically connects the pad electrode 21a and the excitation electrode 22a, and the wiring pattern 24b electrically connects the pad electrode 21b and the excitation electrode 22b. The pad electrode 21a, the excitation electrode 22a, the frequency adjusting metal film 23a, and the wiring pattern 24a are electrically connected to each other. The pad electrode 21b, the excitation electrode 22b, the frequency adjusting metal film 23b, and the wiring pattern 24b are also electrically connected to each other.

  As shown in FIG. 2 [B], the tuning fork element 10 is substantially connected to the pad electrodes 33a and 33b on the element mounting member 32 side via the pad electrodes 21a and 21b (FIG. 1) and the conductive adhesives 31a and 31b. At the same time it is fixed in the shape of a cantilever, it is electrically connected. The element mounting member 32 on which the tuning fork element 10 is mounted is sealed with a lid member 34. For the sealing method, for example, electric welding or molten glass is used.

  Quartz crystals are trigonal. A crystal axis passing through the crystal apex is defined as a Z axis, three crystal axes connecting ridge lines in a plane perpendicular to the Z axis are defined as an X axis, and a coordinate axis orthogonal to the X axis and the Z axis is defined as a Y axis. Here, when the coordinate system consisting of these X, Y, and Z axes is rotated within a range of ± 5 degrees around the X axis, the rotated Y axis and Z axis are respectively represented as Y ′ axis and Z axis. 'As axis. In this case, in the first embodiment, the longitudinal direction of the two vibrating arm portions 12a and 12b is the Y′-axis direction, and the short direction of the two vibrating arm portions 12a and 12b is the X-axis direction. . Further, the crystal plane in which the normal line faces the + X axis direction is the + X plane, and the crystal plane in which the normal line faces the −X axis direction is the −X plane.

  Here, modified examples of the first side to the fourth side 111 to 114 will be described. The first side to the fourth side 111 to 114 are not limited to linear ones, and may be provided with concave portions or convex portions. For example, as shown in FIG. 2C, the first side 111 may be provided with a protrusion 171 and a slit 172 suitable for forming an electrode by the lift-off method, or the third side 113 and the fourth side. 114 may be provided with notches 18a and 18b for suppressing vibration leakage from the vibrating arms 12a and 12b.

  Next, the operation of the tuning fork element 10 will be described. When the tuning fork element 10 is bent and vibrated, an alternating voltage is applied to the pad electrodes 21a and 21b. When an electrical state after application is instantaneously captured, the excitation electrodes 22b provided in the groove portions 15a on the front and back of the vibrating arm portion 12a have a positive potential, and the excitation electrodes 22a provided on both side surfaces of the vibrating arm portion 12a are A negative electric potential is generated, and an electric field is generated from positive to negative. At this time, the excitation electrodes 22a provided in the groove portions 15b on the front and back of the vibrating arm portion 12b have a negative potential, and the excitation electrodes 22b provided on both side surfaces of the vibrating arm portion 12b have a positive potential, and are generated in the vibrating arm portion 12a. The polarity is opposite to the polarity, and an electric field is generated from plus to minus. The electric field generated by the alternating voltage causes a stretching phenomenon in the vibrating arm portions 12a and 12b, and a flexural vibration mode having a predetermined resonance frequency is obtained.

  Next, the operation and effect of the tuning fork element 10 will be described. In FIG. 3 described below, illustration of electrodes and weights is omitted.

  (1) According to the first embodiment, by providing the shoulder portions 14a and 14b extending from the root of the vibrating arm portions 12a and 12b in the short direction of the vibrating arm portions 12a and 12b, the vibrating arm portion 12a Since the vibration transmitted to the support arm portion 13 and the vibration transmitted from the support arm portion 13 to the vibration arm portion 12a can be attenuated by the shoulder portion 14a, electrical characteristics such as reduction of spurious components can be improved.

  The reason is as follows. 3A, the vibration V312a of the vibrating arm 312a is directly transmitted to the support arm 313 as the vibration V21, and the vibration V313 of the support arm 313 is directly converted to the vibration V22. 312a. In contrast, in the first embodiment shown in FIG. 3B, the vibration V12a of the vibrating arm portion 12a is attenuated by the shoulder portion 14a as the vibration V11, and the vibration V13 of the support arm portion 13 is attenuated by the shoulder portion 14a. To do.

  Further, since the shoulder portion 14a is provided, the rigidity of the portion extending from the third side 113 to the vibrating arm portion 12a is increased, so that the element is provided via the pad electrodes 21a and 21b (FIG. 1) provided on the support arm portion 13. Since the stress generated when mounting on the mounting member 32 (FIG. 2B) is not easily transmitted to the vibrating arm portion 12a, the electrical characteristics can be improved from this point. It is not preferable to further extend the shoulder portion 14a in the short direction of the vibrating arm portion 12a so as to be integrated with the supporting arm portion 13 because vibration leakage from the vibrating arm portion 12a to the supporting arm portion 13 is increased. The shoulder 14b is not always necessary and may be omitted.

  (2) In Related Art 2 shown in FIG. 3C, the outer side surface 312c opposite to the facing surface of the vibrating arm portions 312a and 312b is the same surface as the side surface of the base 311. That is, the base 311 has a structure in which it is difficult to suppress vibration at the root of the vibrating arm portions 312a and 312b on one side (outer side surface 312c) of the vibrating arm portions 312a and 312b. For this reason, in the related art 2, as indicated by the phantom line, the vibration at the roots of the vibrating arm portions 312a and 312b cannot be sufficiently suppressed, so that the vibration leakage of the vibrating arm portions 312a and 312b is large and supported by the leaked vibration. The arm part 313 was also easy to vibrate.

  On the other hand, in the first embodiment shown in FIG. 3D, by providing the shoulder portions 14a and 14b, a portion connecting from the third side 113 to the vibrating arm portion 12a and a vibrating arm portion from the fourth side 114 are provided. Since the rigidity of the portion connected to 12b increases, the vibration at the root of the vibrating arm portions 12a and 12b can be suppressed from both sides of the vibrating arm portions 12a and 12b by the base portion 11. For this reason, as indicated by phantom lines, vibrations at the roots of the vibrating arm portions 12a and 12b can be sufficiently suppressed, and the vibrating arm portions 12a and 12b can be vibrated reliably. Can be reduced. Therefore, according to the first embodiment, since the vibration leakage from the vibrating arm portion 12a to the support arm portion 13 can be reduced, the vibration of the support arm portion 13 can also be reduced, so that the electrical characteristics of the tuning fork element 10 can be improved.

  (3) In wet etching of quartz using hydrofluoric acid or the like, etching residues adhere to the quartz by anisotropic etching unique to quartz. In the related technique 2 shown in FIG. 3E, since the structure does not have a shoulder portion, etching residues L1 and L2 are generated on one side of each of the roots of the vibrating arm portions 312a and 312b. These etching residues L1 and L2 have different sizes due to the difference in etching rate. That is, the etching residue L1 generated on the −X plane is larger than the etching residue L2 generated on the + X plane. Thereby, in the related technique 2, since the balance of the bending vibrations of the vibrating arm portions 312a and 312b is lost, abnormal vibration is easily generated and easily transmitted to the support arm portion 313.

  On the other hand, in the first embodiment shown in FIG. 3 [F], since the structure has the shoulder portions 14a and 14b, etching residues L1 and L2 ′ are generated on both sides of the root of the vibrating arm portion 12a, respectively. Etching residues L1 ′ and L2 are generated on both sides of the root of the portion 12b. Here, since the etching residues L1 and L1 'are both generated on the -X plane side, the sizes are almost equal. Since the etching residues L2 and L2 'are both generated on the + X plane, the sizes are almost equal. Therefore, the symmetry between the amount of etching residue (L1 + L2 ′) at the root of the vibrating arm portion 12a and the amount of etching residue (L1 ′ + L2) at the root of the vibrating arm portion 12b can be increased as compared with the related art 2. it can. Therefore, in this Embodiment 1, since the balance of the bending vibration of the vibrating arm portions 12a and 12b becomes good, abnormal vibration can be suppressed. Therefore, according to the first embodiment, by suppressing the transmission of abnormal vibration from the vibrating arm portion 12a to the support arm portion 13, the vibration of the support arm portion 13 can also be suppressed. Therefore, the electrical characteristics of the tuning fork element 10 can be reduced. It can be improved.

  Next, Embodiment 2 will be described. FIG. 4A is a schematic plan view showing the tuning fork element of the second embodiment. 4 and 5 described below, illustration of electrodes and weights is omitted.

  In the second embodiment, tapered portions 41a, 41b, 42a, and 42b having a substantially triangular shape in plan view are provided between the shoulder portions 14a and 14b or the base portion 11 and the vibrating arm portions 12a and 12b. In other words, the taper portion 41a is the + X surface side of the root of the vibrating arm portion 12a, the taper portion 41b is the −X surface side of the root of the vibrating arm portion 12b, the taper portion 42a is the −X surface side of the root of the vibrating arm portion 12a, The taper portion 42b is provided on the + X plane side of the base of the vibrating arm portion 12b.

  According to the second embodiment, since the taper portions 41a, 41b, 42a, and 42b are provided, rigidity at the roots of the vibrating arm portions 12a and 12b can be further increased. Vibration can be more strongly suppressed from both sides of the vibrating arm portions 12a and 12b by the base 11 and the tapered portions 41a, ..., and vibration leakage of the vibrating arm portions 12a and 12b can be further reduced. Therefore, since the vibration of the support arm portion 13 can be suppressed, the electrical characteristics of the tuning fork element can be further improved. Other configurations, operations, and effects of the second embodiment are the same as those of the first embodiment.

  Next, Embodiment 3 will be described. FIG. 4B is a schematic plan view showing the tuning fork element of the third embodiment.

  In the third embodiment, the first side 111 extends from the second side 112 to the first side 111 between the third side 113 or the fourth side 114 provided with the support arm 13 and the support arm 13. The etching residue L3 is generated, and the tip of the first etching residue L3 generated on the −X plane of the crystal plane (in contact with the support arm portion 13) does not exceed the position of the first side 111. In the third embodiment, since the support arm portion 13 is provided only on the third side 113, the tip of the first etching residue L3 exists only between the third side 113 and the support arm portion 13. In other words, the length H1 from the second side 112 to the tip of the first etching residue L3 is shorter than the length H2 from the second side 112 to the first side 111 (that is, H1 <H2 holds).

  The etching residue L3 functions to transmit vibration leakage from the vibrating arm portion 12a to the support arm portion 13 through the base portion 11, and is desirably as small as possible. H1> H2 is not preferable because the etching residue L3 is large and vibration leakage from the vibrating arm 12a to the support arm 13 is increased. According to the third embodiment, since H1 <H2 is satisfied, the etching residue L3 is sufficiently small, so that vibration leakage from the vibrating arm portion 12a to the supporting arm portion 13 can be reduced. Since vibration can also be suppressed, the electrical characteristics of the tuning fork element can be further improved. Other configurations, operations, and effects of the third embodiment are the same as those of the first and second embodiments.

  Next, Embodiment 4 will be described. FIG. 5A is a schematic plan view showing the tuning fork element of the fourth embodiment.

  In the fourth embodiment, a protruding portion 174 protruding in the longitudinal direction of the vibrating arm portions 12a and 12b between the pair of vibrating arm portions 12a and 12b, and a longitudinal direction of the vibrating arm portions 12a and 12b from the tip of the protruding portion 174 And a slit 175 formed on the substrate. A second etching residue L4 is generated between the protrusion 174 and the vibrating arm portions 12a and 12b so as to extend from the first side 111 side in the longitudinal direction of the vibrating arm portions 12a and 12b. A length h 1 from the tip to the first side 111 is shorter than a length h 2 from the tip of the protrusion 174 to the first side 111. The length h2 corresponds to a “projection amount” described later.

  Specifically, in the fourth embodiment, the first side 111 between the pair of vibrating arm portions 12a and 12b is the bottom side, and the apex 173 protrudes in the longitudinal direction of the vibrating arm portions 12a and 12b. And a slit 175 formed in the longitudinal direction of the vibrating arms 12a and 12b from the apex 173. Then, a second etching residue L4 is generated between the slit 175 and the vibrating arm portions 12a and 12b so as to extend from the first side 111 side in the longitudinal direction of the vibrating arm portions 12a and 12b. The tip of the second etching residue L4 is in contact with the vibrating arm portion 12a in the axial direction, and the length h1 from the tip of the second etching residue L4 to the first side 111 is from the tip of the protrusion 174 to the first. It is shorter than the length h2 to the side 111 (that is, h1 <h2 holds). The protruding portion 174 is not limited to a triangular shape, and may have any shape such as a rectangular shape.

  h1> h2 means that the protruding amount of the protrusion 174 is insufficient. Therefore, in the case of h1> h2, if the slit 175 is lengthened so that the electrode film can be separated, the base 11 is easily broken. In particular, when the supporting arm portion 13 is provided, the whole portion becomes heavier, so that it becomes easier to break. Therefore, according to the fourth embodiment, by setting h1 <h2, the protrusion amount of the protrusion 174 can be sufficiently secured, so that the slit 175 can be sufficiently long and the base 11 can be provided even when the support arm 13 is present. Damage can be suppressed. Other configurations, operations, and effects of the fourth embodiment are the same as those of the first to third embodiments.

  Next, Embodiment 5 will be described. FIG. 5B is a schematic plan view showing the tuning fork element of the embodiment.

  In the fifth embodiment, a protruding portion 174 protruding in the longitudinal direction of the vibrating arm portions 12a and 12b between the pair of vibrating arm portions 12a and 12b, and a longitudinal direction of the vibrating arm portions 12a and 12b from the tip of the protruding portion 174 And a slit 175 formed on the substrate. Then, at least one more slit 176 is formed in the direction in which the etching residue is large between the time from the tip of the protrusion 174 to the vibrating arm 12a and the time from the tip of the protrusion 174 to the vibrating arm 12b. ing.

  More specifically, in the fifth embodiment, the first side 111 between the pair of vibrating arm portions 12a and 12b is the base, and the apex 173 protrudes in the longitudinal direction of the vibrating arm portions 12a and 12b in a substantially triangular shape in plan view. And a slit 175 formed in the longitudinal direction of the vibrating arms 12a and 12b from the apex 173. The etching residue in the + X axis direction from the vertex 173 is larger than the etching residue in the −X axis direction from the vertex 173. Therefore, another slit 176 is formed in the protruding portion 174 between the vertex 173 and the vibrating arm portion 12a.

  By forming another slit 176 from the apex 173 to the vibrating arm portion 12a, the size of the etching residue in the + X-axis direction when viewed from the protrusion 174 is adjusted to the etching in the -X-axis direction. The size of the residue can be approached. In other words, the rigidity of each of the second etching residues L4 (FIG. 5 [A]) at the root of the vibrating arm portions 12a and 12b can be made the same. Therefore, in the fifth embodiment, since the balance of flexural vibrations of the vibrating arm portions 12a and 12b is improved, abnormal vibration can be suppressed, and thus vibration of the support arm portion 13 can also be suppressed. The characteristics can be further improved. In addition to this, by providing the two slits 175 and 176, it is possible to further reduce the separation failure of the electrode film. Other configurations, operations, and effects of the fifth embodiment are the same as those of the first to fourth embodiments.

  Next, Embodiment 6 will be described. FIG. 6A is a schematic plan view showing the tuning fork element of the sixth embodiment.

  In the fifth embodiment shown in FIG. 5B, another slit 176 is provided on the left half side of the projection 174, whereas in the sixth embodiment shown in FIG. 6A, the right of the projection 177 is provided. Another slit 178 is provided on the half side. That is, in the sixth embodiment, the projecting portion 177 protruding in the longitudinal direction of the vibrating arm portions 12a and 12b between the pair of vibrating arm portions 12a and 12b and the vibrating arm portions 12a and 12b from the tip 177e of the projecting portion 177. And a slit 175 formed in the longitudinal direction. In addition, at least one more slit 178 is formed in the direction in which the etching residue largely occurs between the tip 177e of the protrusion 177e to the vibrating arm 12a and the tip 177e of the protrusion 177 to the vibrating arm 12b. Is formed.

  Specifically, the protrusion 177 in the sixth embodiment has a first side 111 between the pair of vibrating arm portions 12a and 12b as a base, and a vertex 173 protrudes in the longitudinal direction of the vibrating arm portions 12a and 12b. A triangular projection 177c having a substantially triangular shape in view, and a quadrangular projection 177d having a substantially rectangular shape in plan view protruding in the longitudinal direction of the vibrating arm portions 12a and 12b from the vicinity of the vertex 173 of the triangular projection 177c. In the figure, the rectangular protrusion 177d has a + X plane on the left side and a -X plane on the right side in the drawing. The etching residue generated on the −X plane is larger than the etching residue generated on the + X plane. That is, the etching residue in the −X axis direction from the tip 177e is larger than the etching residue in the + X axis direction from the tip 177e. Therefore, another slit 178 is formed between the tip 177e and the vibrating arm portion 12b.

  By forming another slit 178 between the tip 177e and the vibrating arm portion 12b, the size of the etching residue in the −X axis direction when viewed from the tip 177e of the protrusion 177 is set in the + X axis direction. It is possible to approach the size of the etching residue in In other words, the rigidity of each etching residue at the root of the vibrating arm portions 12a and 12b can be made the same. Therefore, in the sixth embodiment, since the balance of flexural vibrations of the vibrating arm portions 12a and 12b is improved, abnormal vibration can be suppressed, and thus vibration of the support arm portion 13 can also be suppressed. The characteristics can be further improved. In addition to this, by providing the two slits 175 and 178, it is possible to further reduce the separation failure of the electrode film. Other configurations, operations, and effects of the sixth embodiment are the same as those of the fifth embodiment.

  Next, Embodiment 7 will be described. FIG. 6B is a schematic plan view showing the tuning fork element of the seventh embodiment.

  The seventh embodiment is a specific dimension example of the first embodiment shown in FIG. The dimension parallel to the longitudinal direction of the vibrating arm portions 12a and 12b is referred to as “length”, and the dimension parallel to the short direction of the vibrating arm portions 12a and 12b is referred to as “width”. The base 11 has a length L11 of 120 μm (excluding the connecting portion with the support arm 13) and a width W11 of 285 μm. The vibrating arm portions 12a and 12b have a length L12 of 461 μm and a width W12 of 35 μm. The support arm portion 13 has a width W13 of 60 to 80 μm. The weight portions 16a and 16b have a length L16 of 238.6 μm, a width W16 of 165 μm, and a portion connecting the support arm portion 13 and the base portion 11 has a length L10 of 45 μm and a width W10 (including the base portion 11). 500 μm. The tolerance is ± 30 μm to ± 50 μm. Other configurations, operations, and effects of the seventh embodiment are the same as those of the first embodiment.

  Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. Further, the present invention includes a combination of some or all of the configurations of the above-described embodiments as appropriate.

  The present invention can be applied to any tuning fork element including a base, a vibrating arm, and a support arm.

<Embodiment 1>
DESCRIPTION OF SYMBOLS 10 Tuning fork element 11 Base 111 First side 112 Second side 113 Third side 114 Fourth side 12a, 12b Vibration arm part 13 Support arm part 14a, 14b Shoulder part 15a, 15b Groove part 16a, 16b Weight part 171 Projection part 172 Slit 18a, 18b Notch portion 19 Crystal vibrating piece 21a, 21b Pad electrode 22a, 22b Excitation electrode 23a, 23b Frequency adjusting metal film 24a, 24b Wiring pattern 31a, 31b Conductive adhesive 32 Element mounting member 33a, 33b Pad electrode 34 Lid Member L1, L1 ′, L2, L2 ′ Etching residue V11, V12, V12a, V13 Vibration <Embodiment 2>
41a, 41b, 42a, 42b Tapered portion <Embodiment 3>
L3 First etching residue <Embodiment 4>
173 Apex 174 Projection 175 Slit L4 Second etching residue <Embodiment 5>
176 Slit <Embodiment 6>
177 Projection 177c Triangular projection 177d Square projection 177e Tip 178 Slit <Embodiment 7>
L10, L11, L12, L16 Length W10, W11, W12, W13, W16 Width <Related technology 1>
210 tuning fork element 211 base 212a, 212b vibrating arm <related technology 2>
310 tuning fork element 311 base 312a, 312b vibrating arm 312c outer surface 313 supporting arm V21, V22, V312a, V313 vibration

Claims (5)

A substantially quadrangular base portion in plan view composed of first and second sides facing each other and third and fourth sides facing each other;
A pair of vibrating arms extending in the same direction from the first side;
Provided on at least one of the second side of the third side and the second side of the fourth side, extends from the second side in the lateral direction of the vibrating arm portion, and further from the tip thereof A support arm extending in the longitudinal direction of the vibrating arm;
A tuning-fork type crystal vibrating element comprising:
A shoulder portion in which at least one of the third side and the four sides facing the support arm portion extends in a short direction of the vibrating arm portion from a root of the vibrating arm portion,
A tuning-fork type crystal vibrating element further comprising: Between the shoulder portion or the base portion and the vibrating arm portion, a tapered portion having a substantially triangular shape in plan view is provided.
The tuning fork type crystal vibrating element according to claim 1. Between the third side or the fourth side provided with the support arm portion and the support arm portion, a first etching residue is generated so as to extend from the second side to the first side,
The tip of the first etching residue generated in the −X plane of the crystal plane does not exceed the position of the first side,
The tuning-fork type crystal vibrating element according to claim 1 or 2. A protrusion projecting in the longitudinal direction of the vibrating arm part between the pair of vibrating arm parts;
A slit formed in the longitudinal direction of the vibrating arm from the tip of the protrusion,
Between the protruding portion and the vibrating arm portion, a second etching residue is generated so as to extend from the first side in the longitudinal direction of the vibrating arm portion,
The length from the tip of the second etching residue to the first side is shorter than the length from the tip of the protrusion to the first side,
The tuning-fork type crystal vibrating element according to any one of claims 1 to 3. A protrusion projecting in the longitudinal direction of the vibrating arm part between the pair of vibrating arm parts;
A slit formed in the longitudinal direction of the vibrating arm from the tip of the protrusion,
At least one of the etching residue is generated between the leading end of the protruding portion and one of the pair of vibrating arm portions and between the leading end of the protruding portion and the other of the pair of vibrating arm portions. Another slit was formed,
The tuning-fork type crystal vibrating element according to any one of claims 1 to 4.

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