JP2011151780A - Bending vibration piece, vibration device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supporting mechanism of a bending vibration piece, which prevents vibration leakage from a vibration arm to a supporting arm and improves impact resistance. <P>SOLUTION: A tuning-fork type resonator piece 1 includes a pair of vibration arms 3, 4 whose base ends are connected to a base 2 and extended therefrom, and supporting arms 7, 8 which are connected to the base and arranged on both sides of the base in a width direction. The base has a reduced cross-section 15 along both sides thereof, which is formed by making cutouts 13, 14 between the connection with the vibration arms and the connection with the supporting arms. In the reduced cross-section, a length L is set to satisfy the relationship 2×W1≤L≤6×W1 with respect to an arm width W1 of the vibration arms and a width W3 is set to satisfy the relationship W3<W2 with respect to a width W2 between outer side edges of the vibration arms. The supporting arms are connected so that rounded corners 16, 17 are interposed between supporting arms 9, 10 extending both sides of the vibration arms in parallel and connections 11, 12 that connect the supporting arms 9, 10 to the base. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a bending vibration piece, and further relates to a vibration device such as a vibrator or an oscillator in which the bending vibration piece is accommodated in a package.

  Conventionally, vibration devices such as various types of vibrators and oscillators using piezoelectric materials or non-piezoelectric materials have been widely used in communication devices such as mobile phones, information devices such as personal computers, and various other electronic devices. ing. Particularly, recent vibration devices are required to have high precision performance and high stability with a low CI (Crystal Impedance) value as well as further miniaturization as electronic devices become higher performance and smaller.

  In general, a tuning fork type vibrating piece that vibrates in a flexural vibration mode is formed with a longitudinal groove on the front and back main surfaces of the vibrating arm and a main surface side excitation electrode on the inner surface in order to suppress the CI value while reducing the size. The structure is widely adopted. In the tuning fork type vibration piece having such a structure, in order to reduce the CI portion between the vibration piece elements while shortening the base portion and reducing the size, the incision portions are formed on both sides of the base portion, A method for preventing vibration leakage from the base to the base is known (see, for example, Patent Document 1).

  This tuning fork type vibration piece is bonded to the mounting surface by a conductive adhesive or the like at the base and is supported in a cantilever manner. For this reason, there is a limit to downsizing because an area for applying the adhesive to the base is required. In addition, since the distance from the vibrating arm to the bonding position of the base portion is short, there is a possibility that vibration leakage from the vibrating arm cannot be sufficiently prevented even if a cut portion is provided on the side surface of the base portion.

  There is known a structure in which a tuning fork-type vibrating piece is not bonded and fixed at the base, but a support arm extending in parallel with the vibrating arm from the base is provided in a frame shape and fixed and supported by the support arm (for example, , See Patent Document 2). This tuning fork type vibrating piece can be reduced in size by shortening the dimension of the base in the longitudinal direction, and can increase the distance from the vibrating arm to the fixing position of the support arm, thereby suppressing vibration leakage.

  In this way, in the tuning fork type vibrating piece fixedly supported by the support arm extending in parallel with the vibrating arm from the base, it has been proposed to provide a notch at a position closer to the vibrating arm than the support arm of the base (for example, , See Patent Document 3). The cut portion prevents vibration leakage from the vibrating arm to the support arm through the base, thereby increasing the CI value.

JP 2002-261575 A JP 2004-297198 A JP 2006-148857 A

  In the tuning fork type resonator element described in Patent Document 3, it is preferable to reduce the depth of the cut portion to the extent that it matches the outer side edge of the adjacent vibrating arm in order to suppress vibration leakage. Further, according to Patent Document 3, it is preferable that the cut portion is formed at a position exceeding the length of the arm width of the vibrating arm from the end of the base portion to which the vibrating arm is coupled. However, there is no mention of how the length of the cut portion affects the prevention of vibration leakage, that is, the reduction of the CI value.

  The bending vibration piece can be formed of a material having etching anisotropy such as a quartz substrate. In this case, when the external shape of the resonator element is processed by wet etching the crystal substrate, protrusions called fins remain on the side surface of the processed portion due to the orientation of the crystal surface due to the influence of anisotropic etching. In particular, the tuning fork type resonator element is smaller and more complicated in shape.For example, an unfavorable shape fin is generated at the connecting portion between the support arm and the base, causing stress concentration and making the vibration unstable. Or may be damaged by impact.

  Therefore, the present invention has been made to solve at least a part of the conventional problems described above. One object of the present invention is to improve the structure of the base in a flexural vibration piece fixedly supported by a support arm extending from a base portion to which the vibration arm is coupled, and to prevent vibration leakage from the vibration arm to the support arm via the base portion. The object is to improve the vibration characteristics by preventing and reducing the CI value.

  Another object of the present invention is to improve the impact resistance of the bending vibration piece of the support structure while reducing the CI value and reducing the size by preventing vibration leakage.

  Another object of the present invention is to provide a flexural vibration piece that eliminates at least a part of the conventional problems described above, thereby exhibiting excellent vibration characteristics by reducing the CI value, and having excellent impact resistance. An object is to provide a vibration device such as a vibrator and an oscillator, a sensor device, and an electronic device.

  The inventors of the present application provide a flexural vibration piece structured to be fixedly supported by a support arm extending from a base portion to which a vibrating arm is coupled, and a base portion of the vibrating arm extending along the extending direction of the vibrating arm and a supporting arm, In the case where the above-described cut portion or the like is formed between the coupling portion and the cross-section reducing portion in which the cross-sectional size is reduced is provided, the size of the cross-sectional reduction portion, particularly the length, is the CI of the piezoelectric vibrating piece. The effect on the decrease of the value was examined. As a result, by setting the length L of the cross-section decreasing portion in the extending direction of the vibrating arm to 2 × W1 ≦ L, it is possible to effectively suppress the occurrence of vibration leakage from the vibrating arm to the support arm via the base, and the CI value Has been found to be stable and small. Furthermore, from the relationship between the length of the vibrating arm and the length of the base, it was found that the upper limit of the length L is preferably set to L ≦ 6 × W1. The flexural vibration piece of the present invention has been made based on such knowledge.

In order to achieve the above object, the flexural vibration piece of the present invention provides
A base, a vibrating arm extending from one end of the base, and a support arm that is coupled to the opposite end of the base and disposed on both sides thereof.
The base portion has a narrow portion provided with a notch between one end portion and a coupling portion with the support arm on both sides thereof, and the narrow portion is a narrow portion in the longitudinal direction of the vibrating arm. When the length is L and the arm width of the vibrating arm is W1, 2 × W1 ≦ L ≦ 6 × W1 is satisfied.

  Thus, by providing the base with a cross-section decreasing portion having a predetermined length L in the extending direction of the vibrating arm, it is possible to effectively prevent vibration from leaking from the vibrating arm to the support arm via the base, and to stabilize the CI value. The vibration characteristics can be improved.

  In one embodiment, the cross-sectionally reduced portion of the base has a notch between the coupling portion of the vibrating arm and the coupling portion of the support arm along both sides of the base portion, for example, when processing the outer shape of the vibrating piece. By forming simultaneously, it is easily provided without adding another processing step.

  In another embodiment, the vibrating arm is composed of a pair of vibrating arms extending in parallel from the base, and when the width between the outer sides of the pair of vibrating arms is W2, the cross-sectionally reduced portion has its width W3. By providing such that W3 <W2, it is possible to effectively suppress vibration leakage from the vibrating arm to the support arm side through the base.

  In another embodiment, the support arm includes a support arm portion extending in the extending direction of the vibrating arm on both sides in the width direction of the vibrating arm, and a connecting portion extending in the width direction from the base portion and coupled to the support arm portion. By connecting the support arm portion and the connecting portion with the rounded corner portions interposed therebetween, the strength of the connection portion is strengthened, and the impact resistance against dropping or the like can be improved. Furthermore, even when the outer shape of this bending vibration piece is processed by wet etching from a crystal Z plate, a protrusion called a fin formed between the support arm and the base due to the difference in the etching rate depending on the orientation of the crystal surface, This is advantageous because it is relatively gentle and does not easily generate stress concentration.

  According to another aspect of the present invention, by including the bending vibration piece of the present invention described above and a package that accommodates the bending vibration piece, it is possible to reduce vibration leakage and reduce the CI value. A vibration device having excellent impact resistance is provided.

  In one embodiment, the vibrating device includes a supporting arm portion in which the supporting arm of the flexural vibrating piece extends in the extending direction of the vibrating arm on both sides in the width direction of the vibrating arm, and an end portion opposite to the vibrating arm of the base portion. A connecting portion that extends in the width direction and is coupled to the supporting arm portion, the supporting arm portion and the connecting portion are connected across a rounded corner, and the bending vibration piece is a vibrating arm of the supporting arm portion The side portion is fixedly supported on the mounting surface of the package. As a result, the bending vibration piece is supported at a position closer to the center in the longitudinal direction, and the impact acting on the bending vibration piece is absorbed by deformation of the connecting portion and the base side of the support arm. Therefore, the vibration device of the present invention can reduce the deformation of the bending vibration piece on the tip side of the vibrating arm, prevent damage due to contact with the inner surface of the package, and obtain excellent impact resistance against dropping.

  In addition, according to another aspect of the present invention, by including the bending vibration piece of the present invention described above and a circuit element having an oscillation circuit that oscillates the bending vibration piece, the CI value can be reduced by reducing vibration leakage. A vibrating device that functions as an oscillator having a small size and excellent vibration characteristics and impact resistance is provided.

  According to still another aspect of the present invention, by including the above-described bending vibration piece of the present invention and a circuit element having an oscillation circuit that oscillates the bending vibration piece, vibration leakage is reduced and the CI value is reduced. In addition, various electronic devices having excellent vibration characteristics and impact resistance are provided.

The top view of the Example of the tuning fork type vibration piece by this invention. The elements on larger scale which show the principal part of the tuning fork type vibration piece of FIG. (A) A figure and (B) figure are the elements on larger scale which show the connection part of a present Example and the conventional support arm, respectively. FIG. 2 is a diagram illustrating a relationship between a CI value and a narrow portion length L of the tuning fork type vibrating piece in FIG. 1. (A) The figure is the elements on larger scale which show the principal part of the tuning fork type vibration piece of a modification, (B) The figure is sectional drawing in the VV line. (A) The figure is the elements on larger scale which show the principal part of the tuning fork type vibration piece of another modification, (B) The figure is sectional drawing in the VI-VI line. (A) The figure is the elements on larger scale which show the principal part of the tuning fork type vibration piece of another modification, (B) The figure is sectional drawing in the VII-VII line. The longitudinal cross-sectional view of the vibrator | oscillator carrying the tuning fork type vibration piece of FIG. The longitudinal cross-sectional view similar to FIG. 5 which shows the deformation | transformation state of the tuning fork type vibration piece at the time of a drop impact.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are denoted by the same or similar reference numerals.

  FIG. 1 shows a preferred embodiment of a tuning fork type resonator element to which the present invention is applied. The tuning fork type vibrating piece 1 of the present embodiment is formed using a piezoelectric material, and includes a base 2 and a pair of vibrating arms 3 and 4. The vibrating arms 3 and 4 respectively extend in parallel from the base end toward the tip, and are coupled to one end 2a of the base 2 at the base end. Grooves 5 and 6 extending in the longitudinal direction, that is, the extending direction of the vibrating arms are formed on the front and back main surfaces of the vibrating arms 3 and 4, respectively.

  The tuning fork-type vibrating piece 1 further includes a pair of support arms 7 and 8 that are disposed on both sides of the base portion 2 in the width direction perpendicular to the extending direction of the vibrating arms and coupled to the base portion. The support arms 7 and 8 include support arm portions 9 and 10 that extend outside the vibrating arms 3 and 4 in the extending direction of the vibrating arms, and connecting portions 11 and 12 that couple the support arm portions to the base 2. . The connecting portions 11 and 12 extend from the vicinity of the end portion 2b on the opposite side of the vibrating arm of the base portion 2 to both sides in the width direction, and are respectively coupled to the corresponding supporting arm portions.

  Notches 13 and 14 are formed on both sides of the base 2 symmetrically. As shown in FIG. 2, the notches 13 and 14 are provided from a position slightly below the end 2 a to which the vibrating arm is coupled to a position to which the connecting portions 11 and 12 of the support arm are coupled. . By these notches, the base 2 is provided between an end 2a that is a connecting portion with the vibrating arm and an end 2b that is a connecting portion with the support arm along the extending direction of the vibrating arm. A cross-section reducing portion 15 having a reduced cross-sectional size is provided.

  The cross-section reducing portion 15 is provided such that the length L in the longitudinal direction, that is, the extending direction of the vibrating arm satisfies 2 × W1 ≦ L ≦ 6 × W1 with respect to the arm width W1 of the vibrating arm. Further, the width W3 of the cross-section reducing portion 15 is set such that W3 <W2 with respect to the width W2 between the outer sides of the vibrating arms 3 and 4. By providing the cross-section reducing portion 15 in this way, it is possible to effectively suppress the occurrence of vibration leakage from the vibrating arm to the support arm side through the base portion 2.

  Each of the support arms 7 and 8 is rounded at corners 16 and 17 that connect the support arm portions 9 and 10 and the coupling portions 11 and 12, respectively. When the tuning fork type vibrating piece 1 is supported by the support arm portion, stress concentration tends to occur at the joint portion between the support arm portion and the connecting portion. The corners 16 and 17 are rounded from the support arm portions 9 and 10 toward the connecting portions 11 and 12 so that the inner side sides thereof are not bent at a right angle or an acute angle, but the width gradually increases. As a result, the strength of the joint portion is increased. Thereby, the tuning fork type vibrating piece 1 can improve the impact resistance so that it is not easily broken or damaged by an impact such as dropping.

  As described above, the tuning-fork type resonator element 1 of this embodiment can be formed into a desired outer shape using a known photoetching technique with a piezoelectric material such as quartz, lithium tantalate, or lithium niobate. In particular, in the case of forming with quartz, a quartz crystal Z plate cut out by rotating in the range of 0 ° to 5 ° clockwise around the Z axis (optical axis) of the quartz crystal axis is used, and the Y axis (machine) It is customary to orient the axis) in the longitudinal direction of the vibrating arm.

  When the tuning fork type vibrating piece 1 is processed from the crystal Z plate by wet etching, even if a photolithographic exposure mask is prepared to match the desired outer shape of the piezoelectric vibrating piece, the etching rate depends on the orientation of the crystal plane. Due to this difference, protrusions called fins may remain on the edge of the tuning fork type vibrating piece 1 and a desired outer shape may not be obtained. FIG. 3A shows a fin 18 formed between the support arm 7 with the corner 16 rounded and the base 2. The fin 18 has two sides 18a and 18b that intersect at a relatively gentle obtuse angle α in different directions corresponding to the direction of the crystal face.

  FIG. 3B shows a case where the support arm portion 9 ′ and the connecting portion 11 ′ of the support arm 7 ′ are connected at a substantially right angle via an unrounded corner portion 16 ′. In this case, the fin 18 ′ formed between the support arm 7 ′ and the base 2 has two sides 18 a ′ and 18 b ′ that intersect at an angle β close to 90 °. For this reason, in the case of FIG. 3B, stress concentration is likely to occur at the portion where the two sides 18a 'and 18b' of the fin 18 'intersect, and there is a risk of damage due to impact such as dropping. On the other hand, in the present embodiment, stress concentration hardly occurs at the portion where the two sides 18a and 18b of the fin 18 intersect, and excellent impact resistance is exhibited.

  As shown in FIG. 1, first excitation electrodes 19 and 20 are formed on the inner surfaces of the grooves 5 and 6 on the front and back main surfaces of the vibrating arms 3 and 4, and second excitation electrodes 21 and 20 are formed on the side surfaces of the vibrating arms. 22 is formed. The first excitation electrode 19 and the second excitation electrode 21 of one of the vibrating arms are connected to the second excitation electrode 22 and the first excitation electrode 20 of the other vibrating arm, respectively, by cross wiring. Lead electrodes 23 and 24 are formed on the surfaces of the support arms 7 and 8, respectively, one of which is the first excitation electrode 21 and the second excitation electrode 20, and the other 24 is the first excitation electrode 19 and the second excitation electrode 22. Are connected to each other via wiring on the base 2.

  The tuning fork type vibrating piece 1 is fixedly supported on a mounting surface of a package or the like by using, for example, conductive adhesives 25 and 26 near the tips of the supporting arm portions 9 and 10, that is, on the vibrating arm side portion. When a predetermined current is applied to the tuning-fork type vibrating piece 1 from the outside via the extraction electrodes 23 and 24, the vibrating arms 3 and 4 bend and vibrate in directions toward and away from each other at a predetermined frequency. In the present embodiment, by providing the cross-section reducing portion 15 having the above-described size between the end 2a and the end 2b of the base 2, the support arm 7, It is possible to effectively suppress the occurrence of vibration leakage on the 8 side.

  With respect to the tuning-fork type vibrating piece 1 of FIG. 1, an evaluation experiment of the CI value was performed while changing the length L of the cross-section reducing portion 15. Here, the overall length of the tuning-fork type vibrating piece 1 is 2300 μm, the arm width W1 of the vibrating arms 3 and 4 is 100 μm, the arm length is 1600 μm, the width of the base 2 is 250 μm, the length is 700 μm, and the support arms are connected. The widths of the portions 11 and 12 were 140 μm, and the length L of the cross-sectionally reduced portion was changed from 100 μm to 600 μm at intervals of 100 μm. FIG. 4 shows the results of this evaluation experiment.

  As can be seen from the figure, the CI value of the tuning-fork type vibrating piece 1 rapidly decreases at the length L = 200 μm and thereafter is stable and substantially constant. As described above, in this example, the CI value could be reduced in the range of the length L ≧ 200 μm of the cross-section reducing portion 15 with respect to the arm width W1 = 100 μm. Therefore, according to the present invention, it was confirmed that vibration leakage from the base portion 2 to the support arms 7 and 8 can be effectively prevented by providing the cross-section reducing portion 15 so as to satisfy 2 × W1 ≦ L. .

  If the length L of the cross-section reducing portion 15 is too long, the overall length of the tuning fork type vibrating piece 1 becomes long, which is contrary to downsizing. Furthermore, when subjected to a drop impact, the connecting portions 11 and 12 tend to concentrate stress and may be damaged. Therefore, the upper limit of the length L is preferably set to L ≦ 600 μm = 6 × W1. Further, on both side portions of the base portion 2, it is possible to leave portions wider than the cross-section reducing portion 15 at least about 100 μm in length on the end portion 2a side from the positions of the notches 13 and 14. This wide portion is considered to be effective in preventing vibration leakage.

  Further, in this embodiment, as shown in FIG. 2, the wide portion remaining on the end 2 a side of the base 2 is provided so as to protrude in the width direction from the outer sides of the vibrating arms 3 and 4. Yes. In another embodiment, both sides of the wide portion may be aligned with the outer sides of the vibrating arms 3 and 4, and may be provided with the same width as the width W2 between the outer sides of the vibrating arms. In any case, by setting the width W3 of the cross-section reducing portion 15 to be narrower than the width W2 between the outer sides of the vibrating arms 3 and 4, vibration leakage from the base portion 2 to the supporting arm side is effectively suppressed. can do.

  In another embodiment, the tuning fork type vibrating piece 1 can be formed using a non-piezoelectric material. For example, a structure in which a tuning fork type vibration piece is formed of a non-piezoelectric material such as silicon, and a piezoelectric thin film such as zinc oxide (ZnO) or aluminum nitride (AlN) is formed on the surface of the tuning fork type vibration piece as a drive unit for vibrating the vibration piece The present invention can be similarly applied to these vibrators.

  The cross-sectional reduced portion of the base 2 can be provided in various forms other than the notches 13 and 14 in FIG. In the modification shown in FIGS. 5A and 5B, the cross-section reducing portion 41 includes end portions 2 a that are joint portions with the vibrating arms 3 and 4 along the both side portions of the base portion 2, and the support arms 9 and 10. The groove portions 42 and 43 are recessed from both the front and back surfaces to form the thin-walled portions 44 and 45 between the end portion 2b which is the connecting portion of the first and second surfaces. The groove can be processed, for example, by wet etching. In the present embodiment, the groove portions 42 and 43 are formed at the same positions and dimensions as the notches 13 and 14 in FIG. In another embodiment, these grooves can be formed in a size or shape different from the present embodiment.

  In another modification shown in FIGS. 6A and 6B, the cross-section reducing portion 51 has a large number of circular through holes 52 between the end portions 2 a and 2 b along both side portions of the base portion 2. , 53 are formed continuously at substantially regular intervals. The through hole can be processed by dry etching such as wet etching or ion beam etching, laser irradiation, or the like. The through holes 52 and 53 of the present embodiment are formed so as to be located in regions corresponding to the notches 13 and 14 of FIG. In another embodiment, these through-holes can be provided so as to protrude in the width direction from the regions of the notches 13 and 14 or so that the through-holes adjacent in a plane partially overlap each other. Moreover, it can replace with the said through-hole, and can form the said cross-sectional reduction part with many bottomed holes.

  In another modification shown in FIGS. 7A and 7B, the cross-sectionally reduced portion 61 includes a through groove 62 extending between the end 2 a and the end 2 b along both sides of the base 2. 63. The through groove can be processed by, for example, dry etching such as wet etching or ion beam etching. The through grooves 62 and 63 of the present embodiment are formed so as to be located in regions corresponding to the notches 13 and 14 of FIG. In another embodiment, these through holes can be provided so as to protrude in the width direction from the regions of the notches 13 and 14.

  In each of the above-described embodiments, notches, grooves, through holes, or through grooves are formed symmetrically on both sides of the base 2 in order to provide the cross-section reducing portion. However, as long as the cross section of the base portion is reduced between the end portion 2a that is the connecting portion with the vibrating arm and the end portion 2b that is the connecting portion with the support arm in the extending direction of the vibrating arm, It may be asymmetric.

  FIG. 8 shows an embodiment of a vibrator on which the tuning fork type resonator element 1 of FIG. 1 is mounted. The tuning fork vibrator 31 of the present embodiment includes a surface mount type package 32 in order to accommodate the tuning fork type vibrating piece 1. The package 32 includes, for example, a rectangular box-shaped base 33 made of a laminated structure of ceramic thin plates, and a rectangular flat plate-shaped lid 34 made of glass or the like.

  In the base 33, a mount electrode 35 is provided at a position corresponding to a portion of the tuning fork type vibrating piece 1 near the tip of the above-described support arm portions 9, 10 on the bottom surface of a space defined therein. The tuning fork type resonator element 1 is electrically connected to the inside of the base 33 and mechanically fixed and supported by aligning the respective support arms with the corresponding mount electrodes 35 and bonding them with the conductive adhesive 26. . When the lid 34 is airtightly joined to the upper end of the base 33, the tuning fork type vibrating piece is hermetically sealed in the package 32.

  FIG. 9 shows the deformation that occurs in the tuning fork type resonator element 1 when a downward impact is applied to the tuning fork type vibrator 31. By fixing the support arm 8 (7) closer to the tip, that is, not on the base 2 side but on the tip side of the vibrating arm, the tuning fork-type vibrating piece 1 is supported at a position closer to the center in the longitudinal direction. Therefore, the support arm 8 (7) of the tuning fork type vibrating piece 1 is bent downward on the connecting portion 12 (11) side with the fixing position by the conductive adhesive 26 (25) as a fulcrum. At the same time, the vibrating arm 4 (3) bends downward with the connecting portion and the base 2 side as a fulcrum. The impact acting on the tuning fork type vibrating piece 1 in this way is absorbed by deformation of the connecting portion and the base portion 2 side, so that the tip of the vibrating arm 4 (3) is greatly bent and is applied to the inner surface of the package 32. Contact and damage can be prevented.

  However, if the tuning fork-type vibrating piece 1 has an excessively long length L of the cross-section reducing portion 15, when an impact is applied from the outside, the support arm connecting portions 11 and 12 side and / or the vibrating arm bends. May increase, and a greater stress may be concentrated on the connecting portion. In order to prevent this, it is necessary to appropriately select the length L of the cross-section reducing portion. According to the present invention, as described above, it is preferable to set the upper limit of the length L to L ≦ 600 μm = 6 × W1. As a result, the tuning fork vibrator 31 exhibits excellent impact resistance against impacts such as dropping.

  The present invention is not limited to the above embodiments, and can be implemented with various modifications or changes within the technical scope thereof. For example, the present invention can be similarly applied to other various bending vibration pieces having a vibrating arm extending from the base, such as a gyro element having a vibrating arm extending from the base. Further, the flexural vibration piece of the present invention can be mounted on packages having various structures other than the above-described embodiments, and is applied to various vibration devices other than the vibrator, such as an oscillator combined with a circuit element having an oscillation circuit. can do. Furthermore, the bending vibration piece of the present invention can be widely used as a timing device in electronic devices such as digital mobile phones, personal computers, electronic watches, video recorders, and televisions by combining with circuit elements having an oscillation circuit. It can contribute to the improvement of the operating characteristics of electronic equipment.

DESCRIPTION OF SYMBOLS 1 ... Tuning fork type vibration piece, 2 ... Base part, 2a, 2b ... End part, 3, 4 ... Vibrating arm, 5, 6 ... Groove part, 7, 8 ... Support arm, 9, 10 ... Support arm part, 11, 12 ... Connection part, 13, 14 ... cutout, 15, 41, 51, 61 ... cross-section reduced part, 16, 17 ... corner, 18 ... fin, 18a, 18b ... side, 19, 20 ... first excitation electrode, 21, 22 ... second excitation electrode, 23,24 ... extraction electrode, 25,26 ... conductive adhesive, 31 ... tuning fork vibrator, 32 ... package, 33 ... base, 34 ... lid, 35 ... mount electrode, 42,43 ... groove part, 44, 45 ... thin-walled part, 52, 53 ... through hole, 62, 63 ... through groove.

Claims (8)

A vibrating arm extending from the proximal end toward the distal end; a base portion coupled to the vibrating arm at the proximal end; and the base portion disposed on both sides in the width direction orthogonal to the extending direction of the vibrating arm. And a support arm coupled to the
The base has a cross-sectionally reduced portion provided between a coupling portion with the vibrating arm and a coupling portion with the support arm along the extending direction of the vibrating arm, and the cross section in the extending direction of the vibrating arm. Bending characterized in that the cross-sectional reduction portion is provided so that 2 × W1 ≦ L ≦ 6 × W1 is satisfied, where L is the length of the reduction portion and W1 is the arm width of the vibrating arm. Vibrating piece.   2. The cross-sectional reduction part is provided by forming a notch between a joint part with the vibrating arm and a joint part with the support arm along both side parts of the base part. The bending vibration piece as described.   When the vibrating arm is composed of a pair of vibrating arms extending in parallel from the base, and the width between the outer sides of the pair of vibrating arms is W2, and the width of the cross-section reducing portion is W3, W3 < The bending vibration piece according to claim 2, wherein the cross-section reducing portion is provided so as to be W2.   The support arm includes a support arm portion extending in the extending direction of the vibrating arm on both sides in the width direction of the vibrating arm, and a connecting portion extending in the width direction from the base portion and coupled to the support arm portion. The bending vibration piece according to claim 1, wherein the support arm portion and the connecting portion are connected with a rounded corner portion interposed therebetween.   5. A vibration device comprising: the bending vibration piece according to claim 1; and a package that accommodates the bending vibration piece.   5. The bending vibration piece according to claim 4, and a package that accommodates the bending vibration piece, wherein the bending vibration piece is fixedly supported on a mounting surface of the package at a portion of the support arm portion on the vibration arm side. A vibrating device characterized by having   5. A vibrating device comprising: the bending vibration piece according to claim 1; and a circuit element having an oscillation circuit that oscillates the bending vibration piece.   An electronic apparatus comprising: the bending vibration piece according to claim 1; and a circuit element having an oscillation circuit that oscillates the bending vibration piece.

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