JP2011199330A - Vibration piece, vibrator, and oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration piece suppressed in the lowering of a Q value.SOLUTION: The vibration piece 20 has a base 21 where a pair of cuts 31 are formed, a pair of vibration arms 22 mutually extending in parallel from one end side of a first portion of the base 21, and a pair of support arms 30 extending from a second portion 21b of the base 21. Each vibration arm 22 has a general part 23 being a main vibration part, and a wide part 24 in which the width of both side surfaces of the vibration arm is gradually expanded from the general part 23 toward the base 21 at a root side of the base 21. On a principle plane of each vibration arm 22, one long groove 26a having a bottom is formed along a longitudinal direction. At a tip 29A opposite from the root of the base 21 of each vibration arm 22, the long grooves 26a, 26b have narrow parts 26a in each of which the width of an opening is gradually narrowed from the base 21 side toward the tip side.

Description

  The present invention relates to a vibrating piece such as a bending vibrating piece that vibrates in a bending vibration mode, and a vibrator or an oscillator using the same.

  Conventionally, for a vibrating piece that vibrates in a bending vibration mode, for example, a pair of vibrating arms are extended in parallel from the base portion of a base material made of a piezoelectric material such as quartz, and approached or separated from each other in the horizontal direction. Tuning fork-type flexural vibrating pieces that vibrate in the direction of movement are widely used. When the vibration arm of the tuning-fork type bending vibration piece is excited, if the vibration energy is lost, it causes a decrease in the performance of the vibration piece, such as an increase in CI (Crystal Impedance) value and a decrease in Q value. Therefore, various ideas have been conventionally made in order to prevent or reduce such loss of vibration energy.

  For example, there are known tuning-fork type crystal vibrating pieces in which cut portions or cuts (cut grooves) having a predetermined depth are formed on both sides of a base portion from which a vibrating arm extends (for example, Patent Document 1 and Patent Document 2). reference). This tuning-fork type crystal resonator element controls the Q value by enhancing the confinement effect of vibration energy by mitigating the leakage of vibration from the base by cutting when the vibration of the vibrating arm also includes a vertical component. In addition, variations in the Q value between the resonator elements are prevented.

In the resonator element, not only the loss of mechanical vibration energy as described above, but also the temperature generated between the compressive portion where the compressive stress of the vibrating arm which is bent and acting and the extension portion where the tensile stress acts. It is also caused by heat conduction due to the difference. This decrease in the Q value caused by heat conduction is called a thermoelastic loss effect.
In order to prevent or suppress a decrease in the Q value due to the thermoelastic loss effect, a tuning-fork type vibration piece in which a groove or a hole is formed on the center line of a vibrating arm (vibrating beam) having a rectangular cross section is disclosed in Patent Document 3, for example. It has been introduced.

The resonator element described in Patent Document 3 will be specifically described with reference to the drawings. 9A and 9B schematically illustrate a typical example of a conventional vibrating piece, in which FIG. 9A is a plan view, and FIG. 9B is a partially enlarged plan view illustrating a tip portion of a vibrating arm of the vibrating piece. .
9A, the tuning-fork type crystal vibrating piece 1 of Patent Document 3 includes two parallel vibrating arms 3 and 4 extending from the base 2, and straight lines on the center lines of the vibrating arms 3 and 4, respectively. The bottomed long grooves 6 and 7 are provided. When a predetermined drive voltage is applied to an excitation electrode (not shown) of the tuning fork type crystal vibrating piece 1, the vibrating arms 3 and 4 are directed toward or away from each other as indicated by an imaginary line (two-dot chain line) and an arrow in the figure. Bends and vibrates.

Due to this bending vibration, mechanical strain is generated in the region of the base portion of the vibrating arms 3 and 4 with the base portion 2. That is, at the base portion of the vibrating arm 3 with the base portion 2, a first region 10 where compressive stress or tensile stress acts by bending vibration, and when compressive stress acts on the first region 10, tensile stress is generated. When the tensile stress acts on the first region 10, there is a second region 11 in which the compressive stress acts. In the first region 10 and the second region 11, there is compression. The temperature rises when a stress is applied and decreases when a tensile stress is applied.
Similarly, at the base portion of the vibrating arm 4 with the base portion 2, a first region 12 where compressive stress or tensile stress acts by bending vibration, and when compressive stress acts on the first region 12, tensile stress is applied. When a tensile stress acts on the first region 12, there is a second region 13 that is in a relationship in which a compressive stress acts. In the first region 12 and the second region 13, The temperature rises when compressive stress is applied and decreases when tensile stress is applied. Due to the temperature gradient generated in this manner, the base 2 and the base portions of the vibrating arms 3 and 4 are located between the first region 10 and the second region 11 and the first region 12. Thermal conduction occurs with the second region 13. This temperature gradient is generated in the opposite direction corresponding to the bending vibration of each vibrating arm 3, 4, and the heat conduction is also reversed correspondingly. Due to this heat conduction, a part of the vibration energy of the vibrating arms 3 and 4 is always lost as a thermoelastic loss during vibration. As a result, the Q value of the tuning-fork type crystal vibrating piece 1 is lowered and desired vibration characteristics are obtained. It becomes difficult to secure. In the tuning-fork type crystal vibrating piece 1 of Patent Document 3, the heat transfer from the compression side to the tension side is prevented by the long grooves 6 and 7 provided on the center lines of the respective vibrating arms 3 and 4, thereby causing a thermoelastic loss. It is possible to prevent or reduce the decrease in the Q value due to.

JP 2002-261575 A Japanese Patent Laid-Open No. 2004-260718 Japanese Utility Model Publication No. 2-3322

C. Zener and two others, “Internal Friction in Solids III. Experimental Demonstration of Thermoelastic Internal Friction”, PHYSICAL REVIEW, January 1, 1938, Volume 53, p. 10-101

  However, the inventor, in the vibrating piece 1 having the vibrating arms 3 and 4 in which the long grooves 6 and 7 are provided (see Patent Document 3), the first base of the base portion of the vibrating arm when bending vibration is performed. In addition, mechanical strain is generated in the regions 10 and 12 and the second regions 11 and 13, and mechanical strain is also generated on the tip sides of the vibrating arms 3 and 4 (reference numerals 3A and 4A in FIG. 9B). It was found to occur. That is, the shape of the opening on the one end side of the long grooves 6 and 7 on the tip side 3A and 4A opposite to the base of the vibrating arms 3 and 4 with the base 2 is a non-continuous shape that is a right angle or an acute angle than a right angle. In the case of a shape having a corner, stress concentrates on the regions 15 and 16 near the corner to generate a temperature gradient, and the tip side 3A and 4A side of the vibrating arms 3 and 4 due to the temperature gradient. There is a problem that the Q value may be lowered due to heat transfer occurring and causing thermoelastic loss.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A vibrating piece according to this application example includes a base and a vibrating arm extending from the base, and the vibrating arm includes at least one of both main surfaces of the vibrating arm. A bottomed long groove having an opening along the longitudinal direction of the main surface is provided, and the width of the opening on the tip side opposite to the base of the vibrating arm is the width of the vibrating arm. It has a reduced width portion that gradually narrows from the base side with the base portion toward the tip side.

  When the long groove is formed with the same width up to the distal end side of the vibrating arm, the inventor forms a right-angled or relatively acute corner on the end side of the long groove, thereby causing vibration of the vibrating arm. It has been found that a steep strain occurs at the corner of the long groove, and a thermoelastic loss occurs due to a temperature difference caused by the strain, leading to a decrease in the Q value of the resonator element. According to the above configuration, since the width of the opening of the long groove is gradually narrowed on the distal end side of the vibrating arm, the corner on the end side of the long groove is obtuse or rounded. By exhibiting the shape, strain generated on the end side of the long groove due to vibration of the vibrating arm is relieved, and thermoelastic loss is suppressed. Therefore, it is possible to provide a resonator element having excellent vibration characteristics in which the vibration efficiency is improved by the long groove and the CI value is reduced while suppressing a decrease in the Q value due to thermoelastic loss.

  Application Example 2 In the resonator element according to the application example described above, the base point on the base side of the reduced width portion has a rounded shape in plan view.

  According to this configuration, the distortion caused by the vibration of the vibrating arm is more relaxed than when the base point on the base side of the narrowed portion of the long groove has an angular shape in plan view, i.e., a discontinuous shape. Therefore, the remarkable effect which suppresses effectively the fall of Q value accompanying a thermoelastic loss is acquired.

  Application Example 3 In the resonator element according to the application example described above, a plurality of the long grooves are formed in the vibrating arm.

  According to this configuration, a decrease in the Q value due to the thermoelastic effect is suppressed by extending the heat conduction path by the plurality of long grooves, and long grooves having one opening are provided on each main surface of the vibrating arm. Compared to the case, by providing a plurality of long grooves on at least one main surface, the jetty formed at the center of the main surface of the vibrating arm acts as a rib, so that both sides of the vibrating arm Even if the width of the jetty is narrow, sufficient rigidity of the vibrating arm can be ensured.

  Application Example 4 In the resonator element according to the application example, the long groove having an opening on one of the main surfaces and the long groove having an opening on the other main surface are formed. To do.

  According to this configuration, since the thermal relaxation time τ is further extended by making the vibrating arm thinner, it is possible to provide a resonator element that suppresses a decrease in the Q value and has stable vibration characteristics.

  Application Example 5 In the resonator element according to the application example described above, a plurality of the long grooves are formed in at least one of the one main surface and the other main surface.

  According to this configuration, the vibrating arm becomes thinner and the vibrating arm has a S-shaped or M-shaped cross section, so that a heat conduction path through which heat further bypasses is formed. Therefore, it is possible to provide a resonator element in which the Q value is significantly improved.

  Application Example 6 In the resonator element according to the application example described above, a weight portion having a width wider than a base side with the base portion is provided on the distal end side of the vibrating arm.

  According to this configuration, the weight portion at the tip of the vibrating arm performs the function of a weight, so that the frequency can be lowered without increasing the length of the vibrating arm, and the narrow groove has the reduced width portion. As a result, the distortion generated at the end of the long groove when the vibrating arm vibrates is alleviated, so that it is possible to suppress a relatively large thermoelastic loss caused by heat flowing in the wide portion having a large heat capacity. Therefore, it is possible to provide a resonator element that is small in size and excellent in vibration characteristics.

  Application Example 7 In the resonator element according to the application example, two vibrating arms extending in parallel with each other from the base portion are provided, and a supporting arm is interposed between the two vibrating arms of the base portion. It is characterized by being provided to extend in parallel with.

According to this configuration, in addition to the effect of suppressing the thermoelastic loss caused by the characteristic shape of the long groove having the reduced width portion of the vibrating arm, each supporting vibration is provided between the pair of vibrating arms. When the arms vibrate, particularly when the vibrating arms vibrate in directions approaching each other, it is possible to suppress changes in the operating parameters of the vibrating piece caused by the air between the vibrating arms being disturbed.
In addition, various problems that occur when the base is supported and fixed to a package or the like with the base as a support, for example, the tip of the vibrating piece can be prevented from tilting downward and touching the package or the impact on the package can be prevented. Therefore, it is possible to avoid an abnormal operation that may occur by being directly transmitted to the vibrating arm via the arm, and to provide a resonator element having stable vibration characteristics.

  Application Example 8 In the resonator element according to the application example described above, the reduced width portion is formed to have the shape of the opening that is substantially line symmetric with respect to the center line of the long groove. .

  According to this configuration, since the outer shape and the long groove are formed in a well-balanced shape, it is possible to provide a resonator element having more stable vibration characteristics.

  Application Example 9 The vibration piece according to the application example described above is characterized in that the vibration piece is a crystal vibration piece formed of quartz.

  According to this configuration, it is possible to provide a quartz crystal resonator element having high vibration resistance and excellent vibration characteristics in which a decrease in Q value due to thermoelastic loss is suppressed.

  Application Example 10 The vibration piece according to the application example described above is a bending vibration piece exhibiting a bending vibration mode.

  The inventor has found that the present invention having the configuration shown in the application example has a more remarkable effect in a flexural vibration piece exhibiting a flexural vibration mode.

  Application Example 11 A vibrator according to this application example includes the resonator element according to any one of the application examples described above and a package that accommodates the resonator element.

  According to this configuration, since the resonator element according to the above application example is provided, the vibration efficiency is improved by the long groove, the CI value is reduced, and the decrease in the Q value due to the thermoelastic loss is suppressed, and the excellent vibration characteristics. Can be provided.

  Application Example 12 An oscillator according to this application example is characterized in that the resonator element according to the application example described above and a circuit element including an oscillation circuit that oscillates the resonator element are accommodated in a package.

  According to this configuration, since the resonator element according to the above application example is provided, the vibration efficiency is improved by the long groove, the CI value is reduced, and the decrease in the Q value due to the thermoelastic loss is suppressed, and excellent oscillation characteristics are achieved. Can be provided.

(A) is a plan view of one main surface side for schematically explaining one embodiment of the resonator element, (b) is an enlarged cross-sectional view showing a cross section along line A ₁ -A ₁ of (a), (c) ) Is an enlarged plan view of part D _{1 in} (a). (A) ~ (c) are enlarged plan views showing variations of the shape of one end of the long groove as shown in _part D of FIG. 1 (a). (A) is a schematic plan view explaining one Embodiment of the vibrator | oscillator provided with the said vibration piece from the top, (b) is the BB sectional drawing of (a). FIG. 4A is a schematic plan view illustrating an embodiment of an oscillator including the resonator element as viewed from above, and FIG. 4B is a cross-sectional view taken along the line CC of FIG. (A) is a plan view of one main surface side illustrating one variation of the first modification of the resonator element schematically, (b) is a cross-sectional enlarged view showing a (a) A ₂ -A ₂ cross section along line , (c) is a plan enlarged view of D ₂ parts of (a). (A) is a plan view of one main surface side illustrating another variation of the first modification of the resonator element schematically, (b) is (a) A ₄ -A ₄ line enlarged cross-sectional view, (c ) Is an enlarged plan view of part D _{4 in} (a). A plan view on one main surface side schematically illustrating Modification 2 of the resonator element, (b) is an enlarged cross-sectional view showing a cross section along line A ₃ -A ₃ of (a), and (c) is (a) enlarged plan view of a D ₃ parts). (A) is a plan view on one main surface side schematically illustrating Modification 3 of the resonator element, and (b) illustrates one variation of the shape of one end portion of the long groove of the D portion in (a). (C) is an enlarged plan view for explaining another variation of the shape of one end of the long groove of the D part in (a). (A) is a top view which shows typically the typical example of the conventional vibrating element, (b) is the elements on larger scale explaining the front-end | tip part of the vibrating arm of (a).

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of a resonator element according to the invention and a vibrator or an oscillator using the resonator element will be described with reference to the drawings.

[Vibration piece]
First, the resonator element according to the invention will be described.
1A and 1B schematically illustrate a resonator element according to the present embodiment. FIG. 1A is a plan view of one main surface side, and FIG. 1B is a cross-sectional view taken along line A ₁ -A _{1 in} FIG. the enlarged sectional view showing, (c) is a partially enlarged plan view illustrating _a portion D of (a). Also, FIG. 2 (a) ~ (c) is an enlarged plan view showing a variation of the shape of the tip end portion of the long groove as shown in _part D of FIG. 1 (a).

  In FIG. 1A, the resonator element 20 of the present embodiment is made of a piezoelectric material such as quartz, lithium tantalate, or lithium niobate. When the resonator element 20 is made of quartz, the quartz wafer is cut out by rotating it in the range of 0 to 5 degrees clockwise around the Z axis in an orthogonal coordinate system consisting of the X, Y, and Z axes. A crystal Z plate obtained by cutting and polishing to a predetermined thickness is used. The resonator element 20 according to the present embodiment includes a base portion 21 formed by processing the quartz crystal Z plate and a pair of base portions 21 extending in parallel with each other from one end side (upper end side in the drawing). A so-called tuning fork-shaped outer shape including the vibrating arm 22 is formed.

The base portion 21 is formed with a pair of cuts 31 in the opposing direction along one straight line so that a shape confined to both the main surfaces appears. The base portion 21 includes a first portion 21a and a second portion 21b that are located on both sides of the pair of cuts 31, and a connection portion that connects the first portion 21a and the second portion 21b between the pair of cuts 31. 21c. In the vibrating piece 20 of the present embodiment, the transmission of vibration of each vibrating arm 22 is blocked by the notch 31, so that so-called vibration leakage that the vibration is transmitted to the outside via the base 21 and the support arm 30 is suppressed, An increase in CI value can be prevented.
In addition, it is desirable that each notch 31 is adjusted to an optimal width and length after securing the strength against dropping of the vibrating piece 20 to minimize vibration leakage.

As shown in FIG. 1A, the pair of vibrating arms 22 extends from the first portion 21 a of the base portion 21 in parallel to both main surfaces (upper and lower surfaces in the drawing). Each resonating arm 22 has both the main surfaces and both side surfaces connecting the main surfaces on both sides.
Each vibrating arm 22 has a general portion 23 that is a main vibrating portion in the vibrating arm 22 at the center thereof. In addition, each vibrating arm 22 is gradually widened at the base portion connected to the base portion 21 from the general portion 23 toward the base portion 21 side, and is widest at the base portion with the base portion 21. A wide portion 24 is provided. Thus, since each vibrating arm 22 has the wide portion 24, it is connected to the base portion 21 with a wide width, so that rigidity is increased and impact resistance and the like are improved.

One main surface of each vibrating arm 22 is provided with one bottomed long groove 26a along each longitudinal direction. Further, as shown in FIG. 1B, one long groove is also formed along the longitudinal direction of the vibrating arm 22 on the other main surface of one vibrating arm 22 (on the left side in FIG. 1A). 26b is provided. Similarly, although not shown, one bottomed groove 26b is also provided on the other main surface of one vibrating arm 22 (the vibrating arm on the right side in the drawing).
As described above, the long grooves 26a and 26b provided in each vibration arm 22 reduce the rigidity and easily vibrate, and the vibration arm 22 can efficiently vibrate and exhibit good vibration characteristics. Further, the long grooves 26a and 26b are caused by the temperature rise and the temperature drop generated at the jetty portions 25 on both side surfaces of the vibrating arm 22 due to the distortion caused by the vibration in the vicinity of the base portion of the vibrating arm 22 with the base 21. Since the heat flow path is narrowed, the effect of reducing heat elastic loss by suppressing heat transfer is exhibited, and as a result, adverse effects due to thermoelastic loss such as an increase in CI value and a decrease in Q value can be suppressed.

  Further, the long grooves 26a and 26b have a reduced width portion 26A in which the width of the opening gradually narrows from the base portion 21 side toward the distal end side on the distal end side opposite to the base of each vibrating arm 22 with the base portion 21. is doing. In the present embodiment, the base point on the base 21 side of the reduced width portion 26A of each of the long grooves 26a and 26b and the distal end portion of the reduced width portion 26A are formed to have a rounded continuous shape in plan view. In addition, the shapes of the opening portions of the reduced width portions 26A are formed substantially symmetrical with respect to the longitudinal center lines of the vibrating arms 22 and the long grooves 26a and 26b (see FIG. 1C).

Note that the planar view shape of the reduced width portion 26A of the long groove 26a is not necessarily limited to the continuous curved taper shape as shown in FIGS. There is no need to have a right angle or a sharper angle than the right angle in plan view. For example, as shown in FIG. 2A, the front end of the long groove 26a has a substantially circular spread in plan view. As shown in FIG. 2B, the distal end side of the long groove 26a may be flat in a plan view. Also, as shown in FIG. 2C, an angle is formed at the base point on the base side (front side in the drawing) of the reduced width portion 26A. Even if there is a portion, it may be a corner portion that is obtuse than a right angle.
In the present embodiment, as a preferred example in which the vibration characteristics are stabilized by improving the balance of the shape, the shape of the opening of the long grooves 26a and 26b is the center line of the vibrating arm 22 and the long grooves 26a and 26b. However, the present invention is not limited to this. Even if the long grooves 26a and 26b having the reduced width portion 26A are not line symmetric with respect to the center line in the longitudinal direction, the reduced width portion 26A has an effect of improving vibration characteristics as will be described later.

  The vibration piece 20 has a pair of support arms 30 extending from the second portion 21 b of the base portion 21. The pair of support arms 30 intersect with the direction in which the pair of vibrating arms 22 extend from the base portion 21 and extend in opposite directions to each other, and then bend at a substantially right angle at the bent portion 32. The vibrating arm 22 extends in a direction parallel to the extending direction. By bending in this way, the vibration piece 20 having the support arm 30 can be reduced in size. The support arm 30 includes a fixed region that is attached to a package or the like, as will be described later, on the tip side of the bent portion 32 (the same tip side as the tip portion 29A of the vibrating arm 22). The support arm 30 vibrates in the fixed region of the support arm 30. By attaching so as to support the piece 20, the vibrating arm 22 and the base portion 21 can be lifted from the fixed surface of the vibrating piece 20.

  Excitation electrodes 33 and 34 are formed on the surfaces including the long grooves 26a and 26b and the both side surfaces of the vibrating arms 22 (see FIG. 1B). In one vibrating arm 22, the vibrating arm 22 is vibrated by applying a voltage between the excitation electrodes 33 and 34 to expand and contract both side surfaces of the vibrating arm 22. The excitation electrodes 33 and 34 are formed by etching the quartz crystal to form an outer shape including the long grooves 26a and 26b of the resonator element 20, and then depositing nickel (Ni) or chromium (Cr) thereon as an underlayer, for example. Alternatively, an electrode layer made of, for example, gold (Au) can be formed by sputtering and then patterned by photolithography. Here, it is known that chromium has high adhesion to quartz, and gold has low electrical resistance and is difficult to oxidize.

Here, the generation state of the thermoelastic loss when the vibration piece 20 operates and the effect of suppressing the thermoelastic loss by the vibration piece 20 of the present embodiment will be described.
The vibrating piece 20 of the present embodiment vibrates in the bending vibration mode. That is, as shown in FIG. 1A, when a driving voltage is applied to the excitation electrodes 33 and 34 from an oscillation circuit (not shown) as an excitation means connected to the outside (see FIG. 1B), Each vibrating arm 22 vibrates in a direction toward or away from each other in the horizontal direction as indicated by an arrow in the figure.
Due to this bending vibration, in the connection portion of each vibrating arm 22 with the base portion 21, the region of the base portion in the vibration direction of each vibrating arm 22 (region in the vicinity of the boundary with the base portion 21 of the jetty portion 25 of the wide portion 24). Compressive stress or tensile stress corresponding to the bending vibration direction of the vibrating arm 22 is generated.

  Specifically, when the distal end side of the left vibrating arm 22 in the drawing is bent in a direction approaching the right vibrating arm 22 in the drawing, among the jetty portions 25 of the wide portion 24 of the left vibrating arm 22 in the drawing in the drawing. Tensile stress acts on the region near the left jetty 25 and the temperature falls, and compressive stress acts on the region near the right jetty 25 and the temperature rises. Conversely, when the tip side of the left vibrating arm 22 in the drawing is bent away from the right vibrating arm 22 in the drawing, the left side in the drawing of the jetty portion 25 of the wide portion 24 of the vibrating arm 22 on the left in the drawing. Compressive stress acts on the area near the jetty 25 and the temperature rises, and tensile stress acts on the area near the jetty 25 on the right side of the figure and the temperature falls.

  Similarly, when the distal end side of the right vibrating arm 22 in the drawing is bent in a direction approaching the left vibrating arm 22 in the drawing, the left jetty in the jetting portion 25 of the wide portion 24 of the right vibrating arm 22 in the drawing. The compressive stress acts on the region near the portion 25 and the temperature rises, and the tensile stress acts on the region near the jetty portion 25 on the right side in the drawing and the temperature falls. When the tip side of the vibrating arm 22 on the right side in the drawing is bent away from the vibrating arm 22 on the left side in the drawing, the left side in the drawing of the jetty portion 25 of the wide portion 24 of the vibrating arm 22 on the left side in the drawing. Tensile stress acts on the area near the jetty 25 and the temperature falls, and compressive stress acts on the area near the jetty 25 on the right side in the figure and the temperature rises.

  As described above, in the vicinity of the connecting portion of each vibrating arm 22 to the base portion 21, a temperature gradient is generated between the portion where the compressive stress acts and the portion where the tensile stress acts, and the inclination of each vibrating arm 22 The direction is reversed depending on the direction of vibration. Due to this temperature gradient, heat is transferred from the compression side portion to the tension (extension) side portion, that is, from the high temperature side portion to the low temperature side portion, thereby causing a loss of vibrational energy, and CI. Thermoelastic loss that causes deterioration of vibration characteristics such as an increase in value and a decrease in Q value occurs.

  In the resonator element 20 according to the present embodiment, the long grooves 26 a and 26 b formed along the longitudinal direction of both main surfaces of each vibrating arm 22 are formed on both side surfaces of the vibrating arm 22 due to distortion caused by bending vibration of the vibrating arm 22. The heat flow caused by the temperature rise and temperature drop occurring in the vicinity of the base portion 21 of the jetty 25 is narrowed, and the effect of reducing the thermoelastic loss is achieved. It is possible to suppress adverse effects due to thermoelastic loss such as reduction.

  Further, as described above, the thermoelastic loss that occurs in the vicinity of the base of each vibrating arm 22 with the base 21 also causes both of the vibrating arms 22 at the tip of the vibrating arm 22 opposite to the base with the base 21. The inventor has found that this can occur when the end portions of the long grooves 26a and 26b respectively provided on the main surface have a specific shape. That is, at the distal end portion on the opposite side to the root of the base portion 2 of the vibrating arms 3 and 4, like the long grooves 6 and 7 provided in the vibrating arms 3 and 4 of the conventional vibrating piece 1 shown in FIG. When one end side of the opening portion of the long grooves 6 and 7 has an acute corner portion at a substantially right angle or less in plan view, stress concentrates on the regions 15 and 16 near the discontinuous corner portion. Causes a local temperature change. Then, due to the temperature change, a heat flow is generated on the distal end side of the vibrating arms 3 and 4, thereby increasing the thermoelastic loss and degrading the vibration characteristics such as lowering the Q value.

  According to the resonator element 20 of the present embodiment, the long grooves 26 a and 26 b have the width of the opening from the base 21 side to the tip side on the tip side opposite to the base of the vibrating arm 22 with the base 21. It has a narrowed portion 26A that gradually narrows. In addition, since the base point on the base 21 side of the narrowed portion 26A of each of the long grooves 26a and 26b and the distal end portion of the narrowed portion 26A are formed to have a rounded continuous shape in plan view, vibration The structure is such that stress is less likely to concentrate at the ends of the long grooves 26a and 26b during bending vibration of the arm 22. Thereby, the thermoelastic loss due to the bending vibration of the vibrating arm 22 is reduced as compared with the case where the end of the long groove has a corner having a discontinuous shape such as a right angle or an acute angle smaller than the right angle. As a result, it is possible to provide the resonator element 20 having excellent vibration characteristics with a reduction in the Q value.

  Further, in the resonator element 20 of the present embodiment, the shape of the distal end portion of the long grooves 26a and 26b on the opposite side to the base 21 and the shape of the opening of the reduced width portion 26A are the same as those of the long grooves 26a and 26b. It is formed substantially symmetrical with respect to the longitudinal center line. Thus, since the outer shape of the vibrating arm 22 and the long grooves 26a and 26b are formed in a well-balanced shape, the vibrating piece 20 having more stable vibration characteristics can be provided.

[Vibrator]
Next, a vibrator using the vibrating piece 20 will be described.
FIGS. 3A and 3B illustrate an embodiment of a vibrator on which the resonator element 20 is mounted. FIG. 3A is a schematic plan view seen from above, and FIG. 3B is a cross-sectional view taken along line BB in FIG. It is. 3A illustrates a state in which a lid 119 (see FIG. 3B) provided above the vibrator 200 is removed for convenience of explaining the internal structure of the vibrator.

  In FIG. 3, the vibrator 200 has a package 110 provided with a recess having a step. The vibration piece 20 is joined to the concave bottom portion of the concave portion of the package 110, and a lid 119 as a lid is joined to the open upper end of the package 110.

  The package 110 is formed by laminating a rectangular annular second layer substrate 112 and a third layer substrate 113 having different opening sizes on a flat plate-like first layer substrate 111 in this order. A recess having an opening and a step in the interior is formed. As a material of the package 110, for example, ceramic, glass, or the like can be used.

In the recess of the package 110, a plurality of resonator element connection terminals 115 to which the resonator element 20 is bonded are provided on the step formed by the second layer substrate 112. Although not shown, external mounting terminals for joining to an external substrate are provided on the outer bottom surface of the first layer substrate 111 serving as the outer bottom surface of the package 110.
As described above, the various terminals provided in the package 110 are connected to each other by inter-layer wirings such as routing wirings and through holes (not shown).

  The resonator element 20 is bonded to the recess of the package 110. Specifically, the external connection electrode (not shown) provided on a part of the support arm 30 of the resonator element 20 and the step formed by the protrusion 112a of the second layer substrate 112 in the recess of the package 110 are provided. The vibration piece connection terminal 115 is aligned and joined by a conductive joining member 96 such as a silver paste and electrically connected. As a result, the resonator element 20 is fixed with the vibrating arm 22 as a free end while leaving a gap between the resonator element 20 and the first layer substrate 111 that is the concave bottom portion of the recess in the package 110.

  As shown in FIG. 3B, a lid 119 as a lid is disposed on the upper end of the package 110 to which the resonator element 20 is joined in the recess, and seals the opening of the package 110. As a material of the lid 119, for example, a metal such as 42 alloy (an alloy containing 42% nickel in iron) or Kovar (an alloy of iron, nickel, and cobalt), ceramics, glass, or the like can be used. For example, the lid 119 made of metal is joined to the package 110 by seam welding via a seal ring 118 formed by punching a Kovar alloy or the like into a rectangular ring shape. An internal space formed in the package 110 is a space for the vibration piece 20 to operate. The internal space is hermetically sealed in a reduced pressure space or an inert gas atmosphere.

  According to the vibrator 200 having the above-described configuration, since the resonator element 20 having the above-described configuration is provided, the vibration efficiency is improved and the CI value is improved by the long grooves 26a and 26b having the reduced width portions 26A provided in the vibrating arm 22. Thus, it is possible to provide the vibrator 200 having excellent vibration characteristics in which a decrease in the Q value due to the thermoelastic loss is suppressed.

[Oscillator]
Next, an oscillator using the vibrating piece 20 will be described.
FIGS. 4A and 4B illustrate an embodiment of an oscillator on which the resonator element 20 is mounted. FIG. 4A is a schematic plan view seen from above, and FIG. 4B is a cross-sectional view taken along the line CC in FIG. is there. FIG. 4A shows a state in which the lid 219 provided above the oscillator 300 is removed for convenience of explaining the internal structure of the oscillator.

  In FIG. 4, the oscillator 300 has a package 210 provided with a recess having a step. The IC chip 150 and the vibrating piece 20 disposed above the IC chip 150 are joined to the concave bottom portion of the concave portion of the package 210, and a lid 219 as a lid is joined to the open upper end of the package 210. Has been.

  The package 210 is configured by laminating a rectangular-shaped second layer substrate 212, a third layer substrate 213, and a fourth layer substrate 214 having different opening sizes in this order on a flat first layer substrate 211. As a result, a recess having an opening on the upper surface side and having a step inside is formed. As a material of the package 210, for example, ceramic, glass, or the like can be used.

A die pad 215 on which the IC chip 150 is disposed is provided on the first layer substrate 211 which is a concave bottom portion of the concave portion of the package 210. Although not shown, an external mounting terminal for joining to an external substrate is provided on the outer bottom surface of the first layer substrate 211 that is the outer bottom surface of the package 210 (a surface different from the surface on which the die pad 215 is provided). ing.
A plurality of IC connection terminals 216 for electrical connection with the IC chip 150 are provided on the step formed by the second layer substrate 212 in the recess of the package 210.
Furthermore, a plurality of vibration piece connection terminals 217 to which the vibration piece 20 is bonded are provided on the step formed by the third layer substrate 213 in the recess of the package 210.
In the above-described various terminals provided in the package 210, corresponding terminals are connected to each other by an intra-layer wiring such as a lead wiring or a through hole (not shown).

  The IC chip 150 is a semiconductor circuit element including an oscillation circuit that oscillates the resonator element 20 and a temperature compensation circuit. The IC chip 150 is bonded and fixed to the die pad 215 provided at the bottom of the concave portion of the package 210 by, for example, a brazing material 95. In the present embodiment, the IC chip 150 and the package 210 are electrically connected using a wire bonding method. Specifically, a plurality of electrode pads 155 provided on the IC chip 150 and corresponding IC connection terminals 216 of the package 210 are connected by bonding wires 97.

  In the recess of the package 210, the resonator element 20 is bonded above the IC chip 150. Specifically, the external connection electrode (not shown) provided on a part of the support arm 30 of the resonator element 20 and the step formed by the protrusion 213a of the third layer substrate 213 in the recess of the package 210 are provided. The vibrating piece connection terminal 217 is aligned, and is joined and electrically connected by a conductive joining member 96 such as a silver paste. Accordingly, the vibrating piece 20 is fixed with the vibrating arm 22 as a free end while leaving a gap between the vibrating piece 20 and the IC chip 150 bonded downward in the package 210.

  As shown in FIG. 4B, a lid 219 is disposed at the upper end of the package 210 in which the IC chip 150 and the resonator element 20 are joined in the recess, and the opening of the package 210 is sealed. For example, when a lid 219 made of metal is used, it is joined to the package 210 by seam welding via a seal ring 218 formed by punching a Kovar alloy or the like into a rectangular ring shape. An internal space serving as a space for operating the resonator element 20 in the package 210 is hermetically sealed in a reduced pressure space or an inert gas atmosphere.

  According to the oscillator 300 configured as described above, since the resonator element 20 configured as described above is provided, the vibration efficiency is improved and the CI value is improved by the long grooves 26 a and 26 b having the reduced width portions 26 A provided in the vibrating arm 22. It is possible to provide an oscillator 300 that can be reduced and that has excellent oscillation characteristics in which a decrease in Q value due to thermoelastic loss is suppressed.

  The resonator element described in the above embodiment can also be implemented as the following modifications.

(Modification 1)
In the above-described embodiment, the vibrating piece 20 having a configuration in which the long grooves 26 a and 26 b having the same shape are formed on both main surfaces of the vibrating arms 22, respectively, has been described. Not only this but it is good also as a structure which forms a some long groove in each of both the main surfaces of a vibrating arm.
5 and 6 schematically illustrate each of two variations of the first modification of the resonator element having a configuration in which a plurality of long grooves are formed on each of the two main surfaces of the vibrating arm. 6, (a) is a plan view of one main surface side, (b) is an enlarged cross-sectional view showing a cross section taken along line A ₂ -A ₂ or A ₄ -A _{4 of} (a), and (c). is a partially enlarged plan view for explaining the _two-part or D ₄ parts D of (a). In this modification, in FIGS. 5 and 6, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted.

First, the first vibrating piece of Modification 1 will be described.
5 includes a base portion 21 in which a pair of cuts 31 are formed, a pair of vibrating arms 22 extending in parallel from one end side of the first portion 21a of the base portion 21, and a first portion of the base portion 21. A pair of support arms 30 extending from the second portion 21b. Each vibrating arm 22 has a wide portion in which the width of both side surfaces of the vibrating arm is gradually widened from the general portion 23 toward the base 21 side at the base side of the general portion 23 that is a main vibrating portion and the base portion 21. 24.

  One main surface of each vibrating arm 22 of the vibrating piece 40 has a bottomed long groove 46a formed in a substantially half region in the longitudinal direction and a substantially half region different from the region where the long groove 46a is formed. The formed bottomed long groove 46c is provided. The long grooves 46a and 46c are formed on the opposite side of the base of the vibrating arms 22 from the bases of the opening portions formed by the side walls of the long grooves 46a and 46c. The side wall has a reduced width portion 46 </ b> A that gradually narrows toward the inside of the vibrating arm 22. Furthermore, in the resonator element 40 according to the present modification, the base point on the base 21 side of the reduced width portion 46A of each of the long grooves 46a, 46c is formed to have a rounded continuous shape in plan view. The shape of the opening of the reduced width portion 46A is formed substantially symmetrical with respect to the longitudinal center line of the vibrating arm 22 (see FIGS. 5A and 5C).

  As shown in FIG. 5B, the other main surface of each vibrating arm 22 has a bottomed long groove 46b formed in a substantially half region in the longitudinal direction and a region where the long groove 46b is formed. A bottomed long groove 46d formed in approximately half different regions is provided. The long grooves 46b, 46d provided on the other main surface and the long grooves 46a, 46c provided on the one main surface have the same outer shape and are arranged so as to overlap in plan view. ing.

  Excitation electrodes 43 are disposed on both side surfaces of the vibrating arm 22. Excitation electrodes 44 are provided as opposed electrodes of the excitation electrode 43 on the inner walls of the long grooves 46a to 46d on both side surfaces.

Next, a second variation of the resonator element according to Modification 1 will be described.
A vibrating piece 60 shown in FIG. 6 includes two long grooves 66a and 66c provided on one main surface of each vibrating arm 22, and the long groove 66a and the long groove 66c in plan view of the other main surface of each vibrating arm 22. And a long groove 66b provided in a region that does not overlap with the long grooves 66a and 66c.
More specifically, one main surface of each vibrating arm 22 has a bottomed long groove 66a formed in a substantially half region in the longitudinal direction and a substantially half region different from the region where the long groove 66a is formed. The formed bottomed long groove 66c is provided in the center of the vibrating arm 22 in the longitudinal direction with a predetermined interval. These long grooves 66a and 66c are formed on the opposite side of the base of each vibrating arm 22 from the base of each vibrating groove 22 in the shape of the opening formed by the side walls of the long grooves 66a and 66c. The side wall has a reduced width portion 66 </ b> A that gradually narrows toward the inside of the vibrating arm 22 from the base 21 side of the vibrating arm 22 toward the distal end portion 29 </ b> A. Furthermore, in the resonator element 60 of the present modification, the base points on the base 21 side of the reduced width portions 66A of the respective long grooves 66a and 66c are formed so as to have a rounded continuous shape in plan view. The shape of the opening of the reduced width portion 66A is formed to be substantially line symmetric with respect to the longitudinal center line of the vibrating arm 22 (see FIGS. 6A and 6C).

  In addition, the other main surface of each vibrating arm 22 has a substantially central region in the longitudinal direction of the vibrating arm 22 and a region that does not overlap with the long grooves 66a and 66c in plan view. A straight bottomed long groove 66b having side walls parallel to the center side wall of the vibrating arm 22 is provided. In addition, in this modification, although the structure which provides the one long groove 66b in the other main surface side was demonstrated, two or more long grooves provided in this other main surface side may be sufficient.

  Excitation electrodes 63 are respectively disposed on both side surfaces of the vibrating arm 22. In addition, excitation electrodes 64 are provided as opposed electrodes of the excitation electrode 63 on the inner walls on both side surfaces of the long grooves 66a and 66c.

According to the vibration pieces 40 and 60 of the first modification, the shape of the opening of the long grooves 46a to 46d or the long grooves 66a to 66c is formed on the tip side opposite to the base of the vibration arm 22 with the base 21. Of the side walls, the side walls on both sides of each vibrating arm 22 have a reduced width portion 46A or a reduced width portion 66A that gradually narrows toward the inner side of the vibrating arm 22 from the base 21 side toward the distal end side. Moreover, in each of the long grooves 46a to 46b or the long grooves 66a and 66c having the reduced width portion 46A or the reduced width portion 66A, the base point on the base 21 side of the reduced width portion 46A or the reduced width portion 66A is rounded in a plan view. It is formed with a unique shape. Thereby, the effect of improving the vibration efficiency is obtained by the long grooves 46a to 46d or the long grooves 66a to 66c, and the vibrating arms of the long grooves 46a to 46d or the long grooves 66a and 66c when the vibrating arm 22 bends and vibrates in the width direction. 22 has a structure in which stress is hardly concentrated on the end portion on the side surface side, and therefore, the thermoelastic loss associated with the flexural vibration of the vibrating arm 22 is reduced, so that the Q value can be prevented from being lowered and excellent vibration characteristics can be obtained. The vibrating bars 40 and 60 having the above can be provided.
Further, as compared with the configuration in which one long groove 26a, 26b is provided on each main surface of the vibrating arm 22 like the long grooves 26a, 26b of the resonator element 20 of the above embodiment, a plurality of at least one main surface includes a plurality of long grooves 26a, 26b. By providing the long grooves 46a to 46d or the long grooves 66a to 66c, a jetty portion is formed at the center of the main surface of the vibrating arm 22, so that the mechanical strength of the vibrating arm 22 can be improved.

(Modification 2)
In the vibrating pieces 20, 40, 60 of the embodiment and the first modification, the long grooves 26 a, 26 b, the long grooves 46 a to 46 d and the long grooves 66 a, 66 c having the reduced width portions 26 A, 46 A, 66 A are provided on one main surface of the vibrating arm 22. In the above, an example in which the vibrating arm is provided so as to be substantially line symmetric with respect to the center line in the longitudinal direction has been described. The present invention is not limited to this. Even if the long grooves are not provided substantially symmetrically on one main surface of the vibrating arm 22, the long grooves respectively provided on both main surfaces are left and right in plan view with respect to the longitudinal center line of the vibrating arm 22. You may provide so that it may become symmetrical.
7A and 7B schematically illustrate a second modification of the resonator element. FIG. 7A is a plan view of one main surface side, and FIG. 7B is a cross-sectional view taken along line A ₃ -A _{3 in} FIG. (C) is a partial enlarged plan view for explaining part D _{3 of} (a). In addition, in this modification, in FIG. 7, the same code | symbol is attached | subjected about the same structure as the said embodiment, and description is abbreviate | omitted.

  In FIG. 7A, a vibrating piece 80 includes a base portion 21 in which a pair of cuts 31 are formed, a pair of vibrating arms 22 extending in parallel from one end side of the first portion 21a of the base portion 21, and a base portion. 21 and a pair of support arms 30 extending from the second portion 21b. Each resonating arm 22 has a general portion 23 at the center thereof, and has a wide portion 24 in which the widths of both sides of the resonating arm are gradually widened from the general portion 23 toward the base 21 side.

  One main surface of each vibrating arm 22 is provided with one bottomed long groove 86a along a substantially half region in the longitudinal direction. In addition, on the other main surface of each vibrating arm 22, one long groove 86b is provided along a substantially half region (a region different from the region where the long groove 86a is formed) of each vibrating arm 22 in the longitudinal direction. ing. In other words, each of the vibrating arms 22 is arranged such that a bottomed long groove 86a having an opening on one main surface and a bottomed long groove 86b having an opening on the other main surface do not overlap in plan view. Are arranged side by side with openings on different surfaces.

  The long grooves 86a and 86b are formed on the opposite ends of the bases of the vibrating arms 22 from the bases of the openings formed by the side walls of the long grooves 86a and 86b. A reduced width portion 86A that gradually narrows toward the inside of the vibrating arm 22 is provided. Further, in the resonator element 80 of the present modification, the base point on the base 21 side of the reduced width portion 86A of each of the long grooves 86a and 86b is formed to have a rounded continuous shape in plan view. Further, in the resonator element 80 of the present modification, the long grooves 86 a and the long grooves 86 b provided on different main surfaces of the respective vibrating arms 22 are substantially lines with respect to the center line in the longitudinal direction of the vibrating arms 22 in plan view. They are arranged symmetrically. (See FIGS. 7 (a) and (c)).

  As shown in FIG. 7B, excitation electrodes 83 are arranged on both side surfaces of the vibrating arm 22, respectively. Excitation electrodes 84 are provided as opposed electrodes of the excitation electrode 83 on the inner walls of the long groove 86a and the long groove 86b on both side surfaces.

  According to the resonator element 80 of the second modification, the effect of improving the vibration efficiency can be obtained by the long grooves 86a and 86b, similarly to the resonator element 20 of the embodiment and the resonator elements 40 and 60 of the first modification. At the same time, since each of the long grooves 86a and 86b has the reduced width portion 86A, when the vibrating arm 22 bends and vibrates in the width direction, stress concentrates on the end portion on the side surface of the vibrating arm 22 of each of the long grooves 86a and 86b. Since the structure is difficult, it is possible to provide the resonator element 80 having excellent vibration characteristics in which the thermoelastic loss due to the bending vibration of the vibrating arm 22 is reduced and the decrease in the Q value is suppressed.

(Modification 3)
The long grooves 26a, 26b, the long grooves 46a to 46d, the long grooves 66a, 66c having the reduced width portions 26A, 46A, 66A, 86A described in the vibration pieces 20, 40, 60, 80 of the embodiment and the first and second modifications, and the long grooves 66a, 66c, and In the configuration provided with the long grooves 86a and 86b, by providing a weight portion on the tip side opposite to the base side of the base portion of the vibrating arm, it is possible to obtain a low-frequency vibrating piece while maintaining miniaturization.
FIG. 8 schematically illustrates a vibrating piece having a weight portion on a vibrating arm, where (a) is a plan view of one main surface side, and (b) and (c) are views of (a). It is a partial enlarged plan view explaining the variation of the position of the long slot of D section. In addition, in this modification, in FIG. 8, about the same structure as the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  8A, the resonator element 100 includes a base portion 21 in which a pair of cuts 31 are formed, a pair of vibrating arms 122 extending in parallel with each other from one end side of the first portion 21a of the base portion 21, and a base portion. 21 and a pair of support arms 30 extending from the second portion 21b. Each vibrating arm 122 has a wide portion in which the width of both side surfaces of the vibrating arm is gradually widened from the general portion 23 toward the base 21 side at the base side of the general portion 23 that is a main vibrating portion and the base portion 21. 24.

Further, in the resonator element 100 of the present modification, a weight portion 129 having a width wider than that of the general portion 23 is provided on the distal end side of each vibrating arm 122. Thus, by providing the weight portion 129 on the tip side of each vibrating arm 122, the frequency can be lowered without the weight portion 129 fulfilling the function of the weight and increasing the length of the vibrating arm 122.
In the resonator element 100 of the present modification, the width of the weight portion 129 in each vibrating arm 122 (the width between both side surfaces of the vibrating arm 122) is the width of the connecting portion with the base 21 having the widest width portion 24. Is set smaller than. By doing so, the rigidity of the vicinity of the base portion with the base portion 21 of the vibrating arm 122 is strengthened, so that harmonic vibration is suppressed while suppressing the deterioration of the shock resistance of the vibrating arm 122 due to the provision of the weight portion 129. Since suppression can be aimed at, it is preferable.

  On one main surface of each vibrating arm 122, a bottomed long groove 126a extending along the longitudinal direction is provided. Although not shown, the other main surface of each vibrating arm 122 is also provided with a long groove extending along the longitudinal direction of the vibrating arm 122. Each long groove 126a has a reduced width portion 126A in which the width of the opening gradually decreases from the base 21 side toward the distal end side on the distal end side opposite to the base of each vibrating arm 122 with the base 21. . Further, the base point on the base 21 side of each reduced width portion 126A and the distal end portion of the reduced width portion 126A are formed to have a rounded continuous shape in plan view, and the reduced width portions 126A thereof. The shape of the opening is substantially axisymmetric with respect to the longitudinal center line of the long groove 126a.

In the resonator element 100 of the present modification including the vibrating arm 122 having the weight portion 129, as shown in FIGS. 8A and 8B, the distal end side of the long groove 126a (the distal end side of the vibrating arm 122). ) Is formed up to a position on the tip side (the weight portion 129 side) from the boundary between the general portion 23 and the weight portion 129. By doing so, the stress concentration region generated when the vibrating arm 122 vibrates is dispersed in the extending direction of the vibrating arm 122, so that the root portion of the weight portion 129 of the vibrating arm 122 (general portion 23 and weight It is possible to avoid problems such as stress concentration and breakage at the boundary with the portion 129.
As a configuration different from this, as shown in FIG. 8 (c), one end side of the long groove 126 a (the distal end side of the vibrating arm 122) is moved to a position closer to the base 21 side than the boundary between the general portion 23 and the weight portion 129. It is good also as a structure to form. By doing so, the stress concentration region generated when the vibrating arm 122 vibrates is dispersed in the extending direction of the vibrating arm 122, so that the stress is concentrated on the root portion of the weight portion 129 of the vibrating arm 122. In addition to avoiding problems such as breakage, the mass adding effect of the weight portion 129 in each vibrating arm 122 is increased, so that the frequency can be lowered without increasing the size of the vibrating piece 100.

  According to the resonator element 100 of Modification 3 described above, the weight portion 129 at the tip of the vibrating arm 122 serves as a weight, so that the frequency can be lowered without increasing the length of the vibrating arm 122. Since the long groove 126a having the reduced width portion 126A is provided in the vicinity of the weight portion 129, the distortion generated at the end of the long groove 126a when the vibrating arm 122 vibrates is relieved, so that the weight portion having a large heat capacity ( A relatively large thermoelastic loss caused by the flow of heat to the (wide portion) 129 can be suppressed. Therefore, it is possible to provide the resonator element 100 that is small in size and excellent in vibration characteristics.

  The embodiment of the present invention made by the inventor has been specifically described above, but the present invention is not limited to the above-described embodiment, and various modifications are made without departing from the scope of the present invention. Is possible.

  For example, in the above-described embodiment and modification, the thermoelastic loss suppression effect of the present invention has been described using the vibration pieces 20, 40, 60, 80, 100 in the bending vibration mode as an example. The present invention is not limited to this, and even in a vibration piece having a vibration mode other than a bending vibration mode such as a torsional vibration mode and a shearing mode, the same effects as those of the above-described embodiment and the modification can be obtained by providing the characteristic configuration of the present invention. be able to.

  In the above-described embodiment and modification, the so-called tuning fork having the support arm 30 dedicated to the support extended from the base 21 and the two vibrating arms 22 and 122 extending in parallel from the base 21 is formed. The embodiment and the modification of the present invention in the vibration pieces 20, 40, 60, 80, 100 of the mold have been described. However, the present invention is not limited to this, and a vibrating piece having no support arm 30 may be used, or a beam-type vibrating piece configured by only one vibrating arm having a base portion serving as a fixed end may be used. Even if the resonator element has three or more vibrating arms, the same effects as those of the embodiment and the modification can be obtained.

  In the above embodiment and the modification, the vibration pieces 20, 40, 60, 80, 100 made of a piezoelectric material such as quartz have been described. However, the present invention is not limited to this. For example, even with a vibrating piece made of silicon, the same effects as those of the above-described embodiment and the modification can be obtained.

  1, 20, 40, 60, 80, 100 ... vibrating piece, 2, 21 ... base, 3, 4, 22, 122 ... vibrating arm, 6, 7, 26a, 26b, 46a-46d, 66a-66c, 86a, 86b, 126a ... long groove, 15, 16 ... (conventional) near the corner of the long groove, 21a ... (base) first part, 21b ... (base part) second part, 21c ... (base part) Connection part, 23 ... General part, 24 ... Wide part, 25 ... Jetty part, 26A, 46A, 66A, 86A, 126A ... Reduced width part, 29A ... Tip part, 30 ... Support arm, 32 ... Bending part, 33, 34 , 43, 44, 63, 64, 83, 84 ... excitation electrode, 95 ... brazing material, 96 ... conductive bonding member, 97 ... bonding wire, 110, 210 ... package, 111, 211 ... first layer substrate, 112 212 ... Second layer substrate 112a ... Projection 113, 213 ... third layer substrate, 115, 217 ... vibrating piece connection terminal, 118, 218 ... seal ring, 119, 219 ... lid, 129 ... weight, 150 ... IC chip, 155 ... electrode pad, 200 ... vibration , 214, fourth layer substrate, 215, die pad, 300, oscillator.

Claims (12)

The base,
A vibrating arm extending from the base,
The vibrating arm is provided with a bottomed long groove having an opening along the longitudinal direction of at least one of the principal surfaces of the vibrating arm,
On the distal end side of the vibrating arm opposite to the base with the base, the opening has a reduced width portion that gradually narrows from the base side with the base of the vibrating arm toward the distal end. A vibrating piece characterized by that. The resonator element according to claim 1,
The resonator element, wherein a base point on the base side of the reduced width portion has a rounded shape in plan view. In the resonator element according to claim 1 or 2,
A plurality of the long grooves are formed in the vibrating arm. The resonator element according to claim 3,
The resonator element, wherein the long groove having an opening in one of the main surfaces and the long groove having an opening in the other main surface are formed. The resonator element according to claim 4,
A resonator element, wherein a plurality of the long grooves are formed in at least one of the one main surface and the other main surface. In the resonator element according to any one of claims 1 to 5,
A vibrating piece having a weight portion wider on the tip side of the vibrating arm than a base side with the base portion. In the resonator element according to any one of claims 1 to 6,
Two vibrating arms extending parallel to each other from the base are provided,
A vibrating piece, wherein a support arm is provided to extend in parallel with the vibrating arm from between the two vibrating arms of the base. In the resonator element according to any one of claims 1 to 7,
The resonator element, wherein the reduced width portion is formed to have the shape of the opening that is substantially line symmetric with respect to the center line of the long groove. In the resonator element according to any one of claims 1 to 8,
A resonator element, wherein the resonator element is a crystal resonator element formed of quartz. In the resonator element according to any one of claims 1 to 9,
A vibration piece characterized by being a bending vibration piece exhibiting a bending vibration mode. The resonator element according to claim 1,
And a package for housing the resonator element. The resonator element according to claim 1,
An oscillator comprising: a circuit element including an oscillation circuit that oscillates the resonator element in a package.

Images