JP2010232932A - Piezoelectric vibration chip - Google Patents

Piezoelectric vibration chip Download PDF

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JP2010232932A
JP2010232932A JP2009077828A JP2009077828A JP2010232932A JP 2010232932 A JP2010232932 A JP 2010232932A JP 2009077828 A JP2009077828 A JP 2009077828A JP 2009077828 A JP2009077828 A JP 2009077828A JP 2010232932 A JP2010232932 A JP 2010232932A
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arm
vibrating
groove
weight portion
vibrating arm
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Akinori Yamada
明法 山田
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Miyazaki Epson Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To increase an area of an excitation electrode, while making a vibrating arm short, and attain improvement in excitation efficiency and reduction in a CI value as well as miniaturization in a piezoelectric vibration chip of a bending vibration mode. <P>SOLUTION: The vibrating arm 23 of the piezoelectric vibration chip 21 includes a first groove portion 27, extending from an arm portion 24 to an area of a wide spindle portion 25 at a tip of the vibrating arm, on each of top and reverse surfaces thereof, and a first excitation electrode 29 is formed on an internal surface thereof. The spindle portion includes a second bottomed groove portion 28, parallel with the first groove portion, on each of top and reverse surfaces at a part 26 protruding from a side face of the arm portion 24 along the width. A side face of the second groove portion which is adjacent to the first groove portion is formed continuously in level with the side face of the arm portion without any step, and a second excitation electrode 30 is formed continuously on the side face and the side face of the arm part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、例えば振動子や共振子、発振器、ジャイロ、各種センサ等の様々な圧電デバイスに使用され、屈曲振動モードで振動する圧電振動片に関する。   The present invention relates to a piezoelectric vibrating piece that is used in various piezoelectric devices such as vibrators, resonators, oscillators, gyros, and various sensors and vibrates in a bending vibration mode.

従来から、携帯電話等の通信機器や、コンピュータ、ＩＣカード等の情報機器、その他様々な電子機器に圧電デバイスが広く使用されている。最近は、これら電子機器の小型化及び高性能化に伴い、小型化と共に、高品質かつ高安定性の圧電デバイスが要求されている。   Conventionally, piezoelectric devices have been widely used in communication devices such as mobile phones, information devices such as computers and IC cards, and various other electronic devices. Recently, along with miniaturization and high performance of these electronic devices, high quality and high stability piezoelectric devices are demanded along with miniaturization.

屈曲振動モードの圧電振動片は、小型化を図るために振動腕の長さを短くすると、周波数が高くなることがよく知られている。そこで、振動腕の先端部に質量を付加することによって、その質量効果により周波数が高くならないように振動腕の長さを短くし、圧電振動片を小型化することが行われている（例えば、特許文献１，２を参照）。振動腕先端部への質量付加は、多くの場合、該先端部の幅を基端側よりも大きく形成することによってなされる。   It is well known that the bending vibration mode piezoelectric vibrating piece has a higher frequency when the length of the vibrating arm is shortened in order to reduce the size. Therefore, by adding mass to the tip of the vibrating arm, the length of the vibrating arm is shortened so that the frequency does not increase due to the mass effect, and the piezoelectric vibrating piece is reduced in size (for example, (See Patent Documents 1 and 2). In many cases, the mass is added to the distal end portion of the vibrating arm by making the width of the distal end portion larger than the base end side.

また、音叉型圧電振動片においてＣＩ値を低減するために、振動腕の表面及び／又は裏面に長手方向の溝部を形成し、かつ該溝部の内面に励振電極を成膜した構造が広く採用されている（例えば、特許文献２，３を参照）。このような振動腕は、その側面の励振電極と溝部内の励振電極との間で電界が、振動腕の断面において広く分布するように発生し、電界効率が大幅に向上するので、振動片を小型化しても振動損失が少なく、ＣＩ値を低く抑制することができる。   Further, in order to reduce the CI value in the tuning fork type piezoelectric vibrating piece, a structure in which a longitudinal groove is formed on the front and / or back of the vibrating arm and an excitation electrode is formed on the inner surface of the groove is widely adopted. (For example, see Patent Documents 2 and 3). Such a vibrating arm is generated so that the electric field is widely distributed in the cross section of the vibrating arm between the excitation electrode on the side surface and the excitation electrode in the groove, and the electric field efficiency is greatly improved. Even if the size is reduced, vibration loss is small and the CI value can be suppressed low.

更に、振動腕の溝部を振動腕先端の錘部及び基部に入り込む位置まで延長させた構造の音叉型圧電振動片が提案されている（例えば、特許文献４を参照）。このような溝構造の振動腕は、振動腕の基本振動モードを得るために必要な腕長さを確保でき、かつ振動腕の錘部及び基部との各結合部において、振動腕の振動による溝部への応力集中を解消して安定した振動を得ることができる。また、特許文献４には、錘部の基部側に突出部を設けた振動腕が開示されている。この突出部によって、振動腕は、錘部の質量を変えることなく振動二次モーメントの腕長を短くでき、振動の安定性を高めかつＣＩ値を低く抑制することができる。   Furthermore, a tuning-fork type piezoelectric vibrating piece having a structure in which the groove portion of the vibrating arm is extended to a position where it enters the weight portion and the base portion at the tip of the vibrating arm has been proposed (see, for example, Patent Document 4). The vibration arm having such a groove structure can secure the arm length necessary for obtaining the fundamental vibration mode of the vibration arm, and the groove portion due to the vibration of the vibration arm at each joint portion with the weight portion and the base portion of the vibration arm. Stable vibration can be obtained by eliminating stress concentration on the surface. Patent Document 4 discloses a vibrating arm provided with a protruding portion on the base side of the weight portion. With this protrusion, the vibrating arm can shorten the arm length of the vibration secondary moment without changing the mass of the weight portion, and can increase the stability of vibration and suppress the CI value low.

また、従来から、上述した溝部及び錘部を有する振動腕は、音叉型圧電振動片だけでなく、同様に屈曲振動モードで振動する振動腕を有する様々な圧電デバイスに採用されている。例えば回転角度を検出するために、このような振動腕を駆動振動片及び検出振動片に適用した圧電ジャイロスコープが知られている（例えば、特許文献５を参照）。   Conventionally, the above-described vibrating arm having the groove portion and the weight portion is employed not only in a tuning fork type piezoelectric vibrating piece but also in various piezoelectric devices having a vibrating arm that similarly vibrates in a bending vibration mode. For example, in order to detect a rotation angle, a piezoelectric gyroscope in which such a vibrating arm is applied to a drive vibrating piece and a detection vibrating piece is known (see, for example, Patent Document 5).

実公昭５１−１０７５５号公報Japanese Utility Model Publication No. 51-10755 特開２００４−２８２２３０号公報JP 2004-282230 A 国際公開ＷＯ００／４４０９２号公報International Publication WO00 / 44092 特開２００５−５８９６号公報JP 2005-5896 A 特開２００４−３３３４１６号公報JP 2004-333416 A

周知のように、音叉型圧電振動片は、その周波数が振動腕の長さの２乗に反比例し、かつ振動腕の幅に比例する。そのため、特許文献４にも記載されるように、振動腕の長さを短くするほど周波数の変動量が大きくなるので、圧電振動片の小型化には限界がある。従来の音叉型圧電振動片は、振動腕を短くするほど溝部の長さも短くなり、励振電極の面積が減少するので、電界効率の向上及びＣＩ値の抑制を図ることが困難である。   As is well known, the frequency of the tuning-fork type piezoelectric vibrating piece is inversely proportional to the square of the length of the vibrating arm and proportional to the width of the vibrating arm. For this reason, as described in Patent Document 4, since the amount of variation in frequency increases as the length of the vibrating arm is shortened, there is a limit to downsizing the piezoelectric vibrating piece. In the conventional tuning fork type piezoelectric vibrating piece, as the vibrating arm is shortened, the length of the groove portion is shortened and the area of the excitation electrode is reduced. Therefore, it is difficult to improve the electric field efficiency and suppress the CI value.

また、水晶等の圧電材料が、それに作用する応力によって電気分極を生じることも周知である。本願発明者は、振動腕の屈曲振動によって発生する表面電荷に着目し、様々な溝構造を有する音叉型振動片の振動腕について表面電荷分布を解析した。   It is also well known that piezoelectric materials such as quartz produce electrical polarization due to stress acting on them. The inventor of the present application paid attention to the surface charge generated by the bending vibration of the vibrating arm, and analyzed the surface charge distribution of the vibrating arm of the tuning fork type vibrating piece having various groove structures.

図１１（Ａ）（Ｂ）は、従来の典型的な構成の音叉型圧電振動片１を示しており、概ね矩形の基部２と、該基部から平行に延出する１対の振動腕３を備える。各振動腕３は、前記基部に結合された細長い一定幅の腕部４，４と、自由端である先端部に前記腕部よりも広幅に形成された錘部５，５とを有する。振動腕３の表面及び裏面には、それぞれ前記腕部の全長に亘って溝部６、６が形成され、その内面に第１励振電極７，７が、前記腕部の両側面に第２励振電極８，８がそれぞれ成膜されている。一方の振動腕の第１励振電極７と他方の振動腕の第２励振電極８とが互いに接続され、基部２に引き出した接続電極９，９から交流電圧を印加することによって、両振動腕３，３が互いに接近又は離反する向きに振動する。   FIGS. 11A and 11B show a tuning fork type piezoelectric vibrating piece 1 having a typical conventional configuration, and includes a generally rectangular base portion 2 and a pair of vibrating arms 3 extending in parallel from the base portion. Prepare. Each resonating arm 3 has long and narrow arm portions 4 and 4 coupled to the base portion, and weight portions 5 and 5 formed at the distal end portion, which is a free end, wider than the arm portion. Grooves 6 and 6 are formed on the front and back surfaces of the vibrating arm 3 over the entire length of the arm, respectively, the first excitation electrodes 7 and 7 are formed on the inner surface, and the second excitation electrode is formed on both sides of the arm. 8 and 8 are respectively formed. The first excitation electrode 7 of one vibration arm and the second excitation electrode 8 of the other vibration arm are connected to each other, and an alternating voltage is applied from the connection electrodes 9, 9 drawn to the base 2, whereby both vibration arms 3. , 3 vibrate in directions toward or away from each other.

図１２は、このように振動腕３を励振させたときに、その表面に生じる表面電荷分布を示している。同図に示すように、振動腕３が図中左向きに屈曲すると、溝部６の側面６ａには正（＋）の表面電荷が、腕部４の側面４ａには負（−）の表面電荷が発生することを確認できた。振動腕３が逆向きに屈曲すると、側面６ａ及び側面４ａに発生する表面電荷は、極性が反転する。各側面６ａ，４ａの表面電荷密度は、いずれも基端側が高く、先端側が低い。しかしながら、錘部５は、振動腕３の幅方向両側に腕部４よりも突出させて広幅に形成されているので、剛固であり、表面電荷が発生しなかった。   FIG. 12 shows the surface charge distribution generated on the surface of the vibrating arm 3 when excited in this way. As shown in the figure, when the vibrating arm 3 is bent leftward in the drawing, the side surface 6a of the groove 6 has a positive (+) surface charge, and the side surface 4a of the arm 4 has a negative (-) surface charge. It was confirmed that it occurred. When the vibrating arm 3 is bent in the opposite direction, the polarities of the surface charges generated on the side surface 6a and the side surface 4a are reversed. The surface charge densities of the side surfaces 6a and 4a are both high on the base end side and low on the front end side. However, since the weight part 5 is formed wider than the arm part 4 on both sides in the width direction of the vibrating arm 3, it is rigid and no surface charge is generated.

図１３（Ａ）（Ｂ）は、従来の別の音叉型圧電振動片１１を示しており、同様に矩形の基部１２から平行に延出する１対の振動腕１３とを備え、前記各振動腕は、細長い一定幅の腕部１４，１４と、その先端部に前記腕部よりも広幅の錘部１５，１５とを有する。振動腕１３の表面及び裏面には、それぞれ溝部１６、１６が、前記腕部の全長に亘ってかつ前記錘部の領域にまで延長させて形成され、その内面に前記腕部の範囲で第１励振電極１７，１７が、前記腕部の両側面に第２励振電極１８，１８がそれぞれ成膜されている。一方の振動腕の第１励振電極１７と他方の振動腕の第２励振電極１８とが互いに接続され、基部１２の接続電極１９，１９に引き出されている。   FIGS. 13A and 13B show another conventional tuning-fork type piezoelectric vibrating piece 11, which similarly includes a pair of vibrating arms 13 extending in parallel from a rectangular base 12, and each of the vibrations described above. The arm has long and narrow arm portions 14 and 14 and tip portions 15 and 15 having weight portions 15 and 15 wider than the arm portions. Grooves 16 and 16 are formed on the front and back surfaces of the vibrating arm 13 so as to extend over the entire length of the arm part and to the area of the weight part, respectively. Excitation electrodes 17 and 17 are formed as second excitation electrodes 18 and 18 on both side surfaces of the arm portion, respectively. The first excitation electrode 17 of one vibration arm and the second excitation electrode 18 of the other vibration arm are connected to each other and are drawn out to the connection electrodes 19 and 19 of the base 12.

図１４は、接続電極１９，１９に交流電圧を印加して両振動腕１３，１３を互いに接近又は離反する向きに振動させたときに、その表面に生じる表面電荷分布を示している。同図に示すように、振動腕１３が図中左向きに屈曲すると、腕部１４の側面１４ａは、同様に負（−）の表面電荷が発生するのに対し、溝部１６は、腕部１４の範囲内の側面１６ａには正（＋）の表面電荷が発生するが、前記錘部への延長部分の側面１６ｂには表面電荷が発生しないことを確認した。錘部１５の他の部分にも、表面電荷は発生しなかった。この場合も、振動腕１３が逆向きに屈曲すると、側面１６ａ及び側面１４ａの表面電荷は極性が反転し、各側面１６ａ，１４ａの表面電荷密度は基端側が高く、先端側が低い。   FIG. 14 shows a surface charge distribution generated on the surface of the connecting electrodes 19 and 19 when an alternating voltage is applied to vibrate both vibrating arms 13 and 13 in directions approaching or separating from each other. As shown in the figure, when the vibrating arm 13 is bent to the left in the figure, the side surface 14a of the arm portion 14 similarly generates a negative (−) surface charge, whereas the groove portion 16 is formed on the arm portion 14. It was confirmed that a positive (+) surface charge was generated on the side surface 16a within the range, but no surface charge was generated on the side surface 16b of the extension portion to the weight portion. Surface charges were not generated in other portions of the weight portion 15. Also in this case, when the vibrating arm 13 is bent in the opposite direction, the polarities of the surface charges on the side surface 16a and the side surface 14a are reversed, and the surface charge density of each of the side surfaces 16a and 14a is high on the base end side and low on the front end side.

このように上述した従来構造の音叉型圧電振動片は、振動腕を短くするほど、その励振に貢献する電極面積が減少するので、電界効率を向上させてＣＩ値を抑制することが困難になる。圧電材料の圧電効果を考慮すると、電界効率の向上及びＣＩ値の改善を図るためには、振動腕を屈曲振動させたときにその表面に電荷が発生する領域に対応して励振電極を形成すること、及びそのように形成される電極面積を増大させることが好ましい。   As described above, in the tuning fork type piezoelectric vibrating piece having the conventional structure described above, as the vibrating arm is shortened, the electrode area contributing to the excitation decreases, so that it is difficult to improve the electric field efficiency and suppress the CI value. . In consideration of the piezoelectric effect of the piezoelectric material, in order to improve the electric field efficiency and the CI value, an excitation electrode is formed corresponding to a region where electric charges are generated on the surface of the vibrating arm when the vibrating arm is bent and vibrated. It is preferable to increase the area of the electrodes so formed.

そこで本発明は、上述した従来の問題点に鑑みてなされたものであり、その目的は、屈曲振動モードで振動する振動腕を有し、その先端に質量を付加して錘部を形成し、かつ振動腕の表裏面に溝部を設けてその内部に励振電極を形成した圧電振動片において、振動腕を長大化させることなく、その励振に貢献する電極の面積を増大させて、小型化の実現と共に、励振効率の向上及びＣＩ値の低減を図ることにある。   Therefore, the present invention has been made in view of the above-described conventional problems, and its purpose is to have a vibrating arm that vibrates in a flexural vibration mode, and to add a mass to its tip to form a weight portion, In addition, in a piezoelectric vibrating piece that has grooves on the front and back surfaces of the vibrating arm and an excitation electrode is formed inside the vibrating arm, the area of the electrode that contributes to excitation can be increased without increasing the size of the vibrating arm, thereby realizing miniaturization. At the same time, it is to improve the excitation efficiency and reduce the CI value.

本発明の圧電振動片は、上記目的を達成するために、基部と、該基部から延出しかつ屈曲振動モードで振動する振動腕とを備え、
該振動腕が、基部に結合した所定の幅の腕部と、その幅方向に腕部の側面から突出する部分を有するように振動腕先端に形成した広幅の錘部とからなり、
振動腕の表面及び裏面の少なくとも一方にその長手方向に沿って形成された第１溝部と、第１溝部の側面に形成した第１励振電極と、振動腕の側面に形成した第２励振電極とを有し、
第１溝部が、腕部から錘部の領域まで延長するように設けられ、
錘部が、その幅方向の少なくとも一方の側に、第１溝部の側面と平行に延長しかつ腕部の側面から連続してそれと同一面をなす側面を有し、
第２励振電極が、腕部の側面と該側面に連続する錘部の側面とに連続して形成されていることを特徴とする。 In order to achieve the above object, a piezoelectric vibrating piece of the present invention includes a base and a vibrating arm that extends from the base and vibrates in a bending vibration mode.
The vibrating arm includes an arm portion having a predetermined width coupled to the base portion, and a wide weight portion formed at the tip of the vibrating arm so as to have a portion protruding from the side surface of the arm portion in the width direction thereof.
A first groove formed along the longitudinal direction on at least one of the front and back surfaces of the vibrating arm, a first excitation electrode formed on a side surface of the first groove, and a second excitation electrode formed on a side surface of the vibrating arm; Have
The first groove is provided so as to extend from the arm part to the weight part region,
The weight portion has, on at least one side in the width direction, a side surface extending in parallel with the side surface of the first groove portion and continuously extending from the side surface of the arm portion.
The second excitation electrode is formed continuously on the side surface of the arm portion and the side surface of the weight portion continuing to the side surface.

このように第１励振電極を、振動腕の腕部から錘部の領域まで設けた第１溝部の側面に形成し、かつ第２励振電極を、腕部の側面及び該側面から連続する錘部の側面に連続して形成することによって、振動腕の振動に貢献する電界を腕部だけでなく、錘部の領域にも発生させることができる。従って、小型化の要求に対応して振動腕を短くしても、錘部の質量効果を損なうことなく、電極面積を増やして励振効率を高め、ＣＩ値を低減させて圧電振動片の高性能化、高品質化を実現することができる。   Thus, the first excitation electrode is formed on the side surface of the first groove portion provided from the arm portion of the vibrating arm to the region of the weight portion, and the second excitation electrode is formed on the side surface of the arm portion and the weight portion continuous from the side surface. By forming continuously on the side surface, an electric field contributing to the vibration of the vibrating arm can be generated not only in the arm portion but also in the region of the weight portion. Therefore, even if the vibrating arm is shortened in response to the demand for miniaturization, without increasing the mass effect of the weight part, the electrode area is increased to increase the excitation efficiency, and the CI value is reduced to reduce the high performance of the piezoelectric vibrating piece. And high quality can be realized.

或る実施例では、圧電振動片が基部から平行に延長する１対の振動腕を有する音叉型である。別の実施例において、圧電振動片は、３本以上の振動腕を有することができる。   In one embodiment, the piezoelectric vibrating piece is a tuning fork type having a pair of vibrating arms extending in parallel from the base. In another embodiment, the piezoelectric vibrating piece may have three or more vibrating arms.

また、或る実施例では、錘部の腕部の側面から連続してそれと同一面をなす側面が、該錘部の幅方向の突出部分に第１溝部と平行に形成した有底の第２溝部の側面によって形成される。これにより、錘部の突出部分をより大きくし、より多くの質量を付加して、その質量効果を高めることができる。   Further, in one embodiment, the bottomed second side is formed such that a side surface continuously formed from the side surface of the arm portion of the weight portion is formed in parallel with the first groove portion at the protruding portion in the width direction of the weight portion. It is formed by the side surface of the groove. Thereby, the protrusion part of a weight part can be enlarged more, more mass can be added, and the mass effect can be heightened.

別の実施例では、錘部の腕部の側面から連続してそれと同一面をなす側面が、該錘部の幅方向の突出部分を有しない側の側面により形成される。これにより、振動腕の形状をより簡単にし、その加工を容易にすることができる。特に圧電振動片が音叉型の場合には、平行に延出する２本の振動腕の錘部が突出部分を有しない側を内側に配置することによって、それらの間隔をより狭くすることができ、振動片の幅寸法を小さくして、その小型化を図ることができる。   In another embodiment, the side surface that is continuous with the side surface of the arm portion of the weight portion and is flush with the side surface is formed by the side surface that does not have the protruding portion in the width direction of the weight portion. Thereby, the shape of a vibrating arm can be made simpler and the process can be made easy. In particular, in the case where the piezoelectric vibrating piece is a tuning fork type, the interval between the weight portions of the two vibrating arms extending in parallel with the side having no protruding portion can be further narrowed. The width of the resonator element can be reduced to reduce its size.

また、別の実施例では、錘部が、幅方向の一方の側に腕部の側面から突出する前記部分を有し、かつ幅方向の他方の側に、その基部側に腕部の側面から連続して同一面をなす側面と、該側面から幅方向に突出する追加の部分とを有する。これにより、追加の突出部分を設けた分だけ、より高い質量効果が得られると共に、振動腕の長手方向の中心線に関して左右のバランスを改善することができる。   In another embodiment, the weight portion has the portion protruding from the side surface of the arm portion on one side in the width direction, and from the side surface of the arm portion on the base side on the other side in the width direction. It has the side surface which makes the same surface continuously, and the additional part which protrudes in the width direction from this side surface. As a result, a higher mass effect can be obtained as much as the additional protruding portion is provided, and the left-right balance with respect to the center line in the longitudinal direction of the vibrating arm can be improved.

この場合に、別の実施例では、錘部が、幅方向の他方の側において、腕部の側面から連続してそれと同一面をなす側面に、追加の突出部分から基部側に向けて延長する突条を有する。これにより、錘部の質量効果をより高くし、かつ振動腕の長手方向の中心線に関して左右のバランスをより改善することができる。   In this case, in another embodiment, the weight portion extends on the other side in the width direction from the side surface of the arm portion to a side surface that is coplanar with the weight portion and extends from the additional protruding portion toward the base side. Has a ridge. Thereby, the mass effect of a weight part can be made higher, and the left-right balance can be further improved with respect to the longitudinal center line of the vibrating arm.

（Ａ）図は本発明による圧電振動片の第１実施例の概略平面図、（Ｂ）図及び（Ｃ）図はそれぞれ（Ａ）図のＩａ−Ｉａ線、Ｉｂ−Ｉｂ線における断面図。(A) is a schematic plan view of a first embodiment of a piezoelectric vibrating piece according to the present invention, and (B) and (C) are cross-sectional views taken along lines Ia-Ia and Ib-Ib in FIG. 第１実施例の振動腕の表面電荷分布を示す斜視図。The perspective view which shows the surface charge distribution of the vibrating arm of 1st Example. （Ａ）図は本発明による圧電振動片の第２実施例の概略平面図、（Ｂ）図及び（Ｃ）図はそれぞれ（Ａ）図のIIIａ−IIIａ線、IIIｂ−IIIｂ線における断面図。(A) is a schematic plan view of a second embodiment of a piezoelectric vibrating piece according to the present invention, and (B) and (C) are cross-sectional views taken along lines IIIa-IIIa and IIIb-IIIb in FIG. 第２実施例の振動腕の表面電荷分布を示す斜視図。The perspective view which shows the surface charge distribution of the vibrating arm of 2nd Example. （Ａ）図は本発明による圧電振動片の第３実施例の概略平面図、（Ｂ）図及び（Ｃ）図はそれぞれ（Ａ）図のＶａ−Ｖａ線、Ｖｂ−Ｖｂ線における断面図。(A) is a schematic plan view of a third embodiment of a piezoelectric vibrating piece according to the present invention, and (B) and (C) are cross-sectional views taken along lines Va-Va and Vb-Vb in FIG. 第３実施例の振動腕の表面電荷分布を示す斜視図。The perspective view which shows the surface charge distribution of the vibrating arm of 3rd Example. （Ａ）図は本発明による圧電振動片の第４実施例の概略平面図、（Ｂ）図及び（Ｃ）図はそれぞれ（Ａ）図のVIIａ−VIIａ線、VIIｂ−VIIｂ線における断面図。(A) is a schematic plan view of a fourth embodiment of a piezoelectric vibrating piece according to the present invention, and (B) and (C) are cross-sectional views taken along lines VIIa-VIIa and VIIb-VIIb in FIG. 第４実施例の振動腕の表面電荷分布を示す斜視図。The perspective view which shows the surface charge distribution of the vibrating arm of 4th Example. （Ａ）図は本発明による圧電振動片の第５実施例の概略平面図、（Ｂ）図及び（Ｃ）図はそれぞれ（Ａ）図のIXａ−IXａ線、IXｂ−IXｂ線における断面図。(A) is a schematic plan view of a fifth embodiment of a piezoelectric vibrating piece according to the present invention, and (B) and (C) are sectional views taken along lines IXa-IXa and IXb-IXb in FIG. 第５実施例の振動腕の表面電荷分布を示す斜視図。The perspective view which shows the surface charge distribution of the vibrating arm of 5th Example. （Ａ）図は従来の圧電振動片の概略平面図、（Ｂ）図は（Ａ）図のXI−XI線における断面図。FIG. 4A is a schematic plan view of a conventional piezoelectric vibrating piece, and FIG. 4B is a cross-sectional view taken along line XI-XI in FIG. 図１１の振動腕の表面電荷分布を示す斜視図。FIG. 12 is a perspective view illustrating a surface charge distribution of the vibrating arm in FIG. 11. （Ａ）図は従来の別の圧電振動片の概略平面図、（Ｂ）図は（Ａ）図のXIII−XIII線における断面図。(A) is a schematic plan view of another conventional piezoelectric vibrating piece, and (B) is a cross-sectional view taken along line XIII-XIII in FIG. 図１３の振動腕の表面電荷分布を示す斜視図。FIG. 14 is a perspective view illustrating a surface charge distribution of the vibrating arm in FIG. 13.

以下に、添付図面を参照しつつ、本発明の好適な実施例を詳細に説明する。尚、添付図面において、同一又は類似の構成要素には、同一又は類似の参照符号を付して示す。
図１（Ａ）〜（Ｃ）は、本発明による音叉型圧電振動片の第１実施例を概略的に示している。本実施例の音叉型圧電振動片２１は、水晶等の圧電材料で一体に形成され、概ね矩形の基部２２と、該基部から平行に延出する１対の振動腕２３とを備える。各振動腕２３は、前記基部に結合された所定の幅の細長い腕部２４と、その自由端である先端部に前記腕部よりも広幅に形成された錘部２５とを有する。各錘部２５は、振動腕２３の幅方向両側に腕部２４の側面から突出する部分２６，２６を有する。 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.
1A to 1C schematically show a first embodiment of a tuning-fork type piezoelectric vibrating piece according to the present invention. The tuning fork type piezoelectric vibrating piece 21 of the present embodiment is integrally formed of a piezoelectric material such as quartz, and includes a substantially rectangular base portion 22 and a pair of vibrating arms 23 extending in parallel from the base portion. Each resonating arm 23 has an elongated arm portion 24 having a predetermined width coupled to the base portion, and a weight portion 25 formed wider at the tip portion which is a free end than the arm portion. Each weight portion 25 has portions 26 and 26 protruding from the side surfaces of the arm portion 24 on both sides in the width direction of the vibrating arm 23.

振動腕２３の表面及び裏面には、その長手方向に沿って断面矩形かつ一定の第１溝部２７，２７がそれぞれ形成されている。第１溝部２７は、前記腕部の全長に亘って、かつ該腕部から連続的に前記錘部の中央付近まで延長するように設けられる。更に、錘部２５の表面及び裏面には、前記両突出部分に有底の第２溝部２８，２８がそれぞれ形成されている。第２溝部２８は、突出部分２６の基部側端部から第１溝部２７の錘部２５への延長部分の範囲でかつそれと平行に延長させて設けられる。第２溝部２８の前記第１溝部に隣接する側面は、腕部２４の側面から連続して段差のない同一面に形成されている。   On the front and back surfaces of the resonating arm 23, first groove portions 27, 27 having a rectangular cross section and a constant length are formed along the longitudinal direction. The first groove portion 27 is provided so as to extend over the entire length of the arm portion and continuously from the arm portion to the vicinity of the center of the weight portion. Further, on the front and back surfaces of the weight portion 25, bottomed second groove portions 28 and 28 are formed in the protruding portions, respectively. The second groove portion 28 is provided in a range of an extended portion from the base side end portion of the protruding portion 26 to the weight portion 25 of the first groove portion 27 and extending in parallel therewith. The side surface adjacent to the first groove portion of the second groove portion 28 is formed on the same surface without a step continuously from the side surface of the arm portion 24.

第１溝部２７の内面には、第１励振電極２９が前記錘部への延長部分を含む全長に亘って形成されている。連続する腕部２４の側面及び第２溝部２８の前記第１溝部に隣接する側面には、それらの全長に亘って第２励振電極３０が連続して形成されている。一方の前記振動腕の第１励振電極２９と他方の振動腕の第２励振電極３０とが互いに接続され、かつ基部２２の接続電極３１，３１に引き出されている。前記接続電極に交流電圧を印加すると、両振動腕２３，２３が互いに接近又は離反する向きに振動する。   A first excitation electrode 29 is formed on the inner surface of the first groove portion 27 over the entire length including the extension portion to the weight portion. The second excitation electrode 30 is continuously formed over the entire length of the side surface of the continuous arm portion 24 and the side surface of the second groove portion 28 adjacent to the first groove portion. The first excitation electrode 29 of one of the vibrating arms and the second excitation electrode 30 of the other vibrating arm are connected to each other and drawn out to the connection electrodes 31 and 31 of the base 22. When an AC voltage is applied to the connection electrode, the vibrating arms 23 and 23 vibrate in directions toward or away from each other.

図２は、このように振動腕２３，２３を振動させたときに、その表面に生じる表面電荷分布を示している。同図に示すように、振動腕２３が図中左向きに屈曲すると、第１溝部２７の側面２７ａには、前記錘部への延長部分の側面２７ｂを含む全長に亘って正（＋）の表面電荷が発生した。腕部２４の各側面２４ａ及びそれに連続する第２溝部２８の前記第１溝部に隣接する各側面２８ａには、負（−）の表面電荷が発生することを確認した。これら以外の錘部２５の部分は、表面電荷が発生しなかった。側面２７ａ，２７ｂ及び側面２４ａ，２８ａの表面電荷密度は、いずれも基端側が高く、先端側が低かった。振動腕２３が逆向きに屈曲すると、その表面に発生する表面電荷は、極性が反転する。   FIG. 2 shows the surface charge distribution generated on the surface of the vibrating arms 23 and 23 when they are vibrated in this way. As shown in the figure, when the vibrating arm 23 is bent leftward in the figure, the side surface 27a of the first groove portion 27 has a positive (+) surface over the entire length including the side surface 27b of the extension portion to the weight portion. Charge was generated. It was confirmed that negative (−) surface charge was generated on each side surface 24a of the arm portion 24 and each side surface 28a adjacent to the first groove portion of the second groove portion 28 continuous thereto. Surface charge was not generated in the portions of the weight portion 25 other than these. The surface charge densities of the side surfaces 27a and 27b and the side surfaces 24a and 28a were both high on the base end side and low on the front end side. When the vibrating arm 23 is bent in the opposite direction, the polarity of the surface charge generated on the surface thereof is reversed.

別の実施例では、錘部２５の表裏面を貫通するように第２溝部２８を形成することができ、その場合にも、該第２溝部の第１溝部２７に隣接する側面には、振動腕２３の屈曲振動により表面電荷が発生する。しかしながら、突出部分２６が部分的に貫通溝により分離されて、腕部側と平行に基部２２側に延出することになるので、振動腕２３の振動時に不要な振動モードを発生したり、腕部側と接触する虞がある。従って、第２溝部２８は、少なくとも部分的に貫通しないように形成するのが好ましい。   In another embodiment, the second groove portion 28 can be formed so as to penetrate the front and back surfaces of the weight portion 25, and in this case as well, the side surface of the second groove portion adjacent to the first groove portion 27 has vibration. Surface charges are generated by bending vibration of the arm 23. However, since the protruding portion 26 is partially separated by the through groove and extends to the base portion 22 side in parallel with the arm portion side, an unnecessary vibration mode is generated when the vibrating arm 23 vibrates, There is a risk of contact with the part side. Therefore, it is preferable to form the second groove portion 28 so as not to penetrate at least partially.

このように振動腕２３は、その屈曲振動により表面電荷が発生する領域が、第１溝部２７を錘部２５の領域まで延長させかつ前記錘部の突出部分２６に第２溝部２８を設けることによって、錘部２５まで拡大されている。その結果、振動腕２３の励振に貢献する第１及び第２励振電極２９，３０を、腕部２４だけでなく、錘部２５の領域にも形成することができる。従って、本実施例の圧電振動片２１は、小型化の要求に対応して振動腕を短くしても、錘部の質量効果を損なうことなく、励振電極の面積を大きくして励振効率を高めることができるので、ＣＩ値を低減させることができる。   As described above, the vibrating arm 23 has a region where surface charges are generated by the bending vibration by extending the first groove portion 27 to the weight portion 25 region and providing the second groove portion 28 in the protruding portion 26 of the weight portion. , The weight portion 25 is enlarged. As a result, the first and second excitation electrodes 29 and 30 that contribute to the excitation of the vibrating arm 23 can be formed not only in the arm portion 24 but also in the region of the weight portion 25. Therefore, the piezoelectric vibrating piece 21 of this embodiment increases the area of the excitation electrode and increases the excitation efficiency without impairing the mass effect of the weight portion even if the vibrating arm is shortened in response to the demand for miniaturization. Therefore, the CI value can be reduced.

図３（Ａ）〜（Ｃ）は、本発明による音叉型圧電振動片の第２実施例を概略的に示している。本実施例の音叉型圧電振動片４１は、第１実施例と同様に水晶等の圧電材料で一体に形成され、概ね矩形の基部４２から平行に延出する１対の振動腕４３を備える。各振動腕４３は、前記基部に結合された所定の幅の細長い腕部４４と、その先端部に前記腕部よりも広幅に形成された錘部４５とを有するが、錘部４５が、他方の振動腕４３とは反対側の幅方向にのみ腕部４４の側面から突出する部分４６を有する、という点において、第１実施例と異なる。これにより、両振動腕４３を第１実施例の場合よりも接近させて配置することができるので、圧電振動片４１の幅寸法を小さくすることができる。   3A to 3C schematically show a second embodiment of a tuning-fork type piezoelectric vibrating piece according to the present invention. The tuning fork type piezoelectric vibrating piece 41 of the present embodiment is formed integrally with a piezoelectric material such as quartz as in the first embodiment, and includes a pair of vibrating arms 43 extending in parallel from a substantially rectangular base 42. Each vibrating arm 43 has an elongated arm portion 44 having a predetermined width coupled to the base portion and a weight portion 45 formed wider at the tip portion than the arm portion. This is different from the first embodiment in that it has a portion 46 that protrudes from the side surface of the arm portion 44 only in the width direction opposite to the vibrating arm 43. Thereby, since both the vibrating arms 43 can be arranged closer than in the case of the first embodiment, the width dimension of the piezoelectric vibrating piece 41 can be reduced.

振動腕４３の表面及び裏面には、その長手方向に沿って断面矩形かつ一定の第１溝部４７，４７が、それぞれ前記腕部の全長に亘って、かつ該腕部から連続的に前記錘部の中央付近まで延長するように形成されている。錘部４５の突出部分４６には、その表面及び裏面に有底の第２溝部４８，４８が、それぞれ該突出部分の基部側端部から第１溝部４７の錘部４５への延長部分の範囲でかつそれと平行に延長させて形成されている。第２溝部４８の前記第１溝部に隣接する側面及び錘部４５の他方の振動腕に隣接する側面は、それぞれ対応する腕部４４の側面から連続する段差のない同一面に形成されている。   On the front and back surfaces of the vibrating arm 43, first groove portions 47 and 47 having a rectangular cross section and a constant length along the longitudinal direction respectively extend over the entire length of the arm portion and continuously from the arm portion. It is formed to extend to the vicinity of the center. The projecting portion 46 of the weight portion 45 has bottom grooves 48 and 48 on the front and back surfaces thereof, respectively, extending from the base side end of the projecting portion to the weight portion 45 of the first groove portion 47. In addition, it is formed to extend in parallel with it. The side surface adjacent to the first groove portion of the second groove portion 48 and the side surface adjacent to the other vibrating arm of the weight portion 45 are formed on the same surface without a step difference from the side surface of the corresponding arm portion 44.

第１溝部４７の内面には、第１励振電極４９が前記錘部への延長部分を含む全長に亘って形成されている。腕部４４の外側の側面即ち他方の振動腕とは反対側の側面及びそれに連続する第２溝部４８の前記第１溝部に隣接する側面には、それらの全長に亘って第２励振電極５０ａが連続して形成されている。腕部４４の内側即ち他方の振動腕に隣接する側の側面には、第２励振電極５０ｂが全長に亘って形成され、かつそれから錘部４５の他方の振動腕に隣接する側の側面に連続して、第１溝部４７の錘部４５への延長部分に対応する範囲にまで延長して設けられている。一方の前記振動腕の第１励振電極４９と他方の振動腕の第２励振電極５０ａ，５０ｂとが互いに接続されており、これらに交流電圧を印加することによって、両振動腕４３，４３が互いに接近又は離反する向きに振動する。   A first excitation electrode 49 is formed on the inner surface of the first groove portion 47 over the entire length including the extension portion to the weight portion. On the outer side surface of the arm portion 44, that is, the side surface opposite to the other vibrating arm and the side surface adjacent to the first groove portion of the second groove portion 48 continuous therewith, the second excitation electrode 50a extends over the entire length thereof. It is formed continuously. A second excitation electrode 50b is formed over the entire length of the inner side of the arm portion 44, that is, on the side surface adjacent to the other vibrating arm, and then continues to the side surface of the weight portion 45 adjacent to the other vibrating arm. In addition, the first groove portion 47 is provided so as to extend to a range corresponding to the extension portion to the weight portion 45. The first excitation electrode 49 of one of the vibrating arms and the second excitation electrodes 50a and 50b of the other vibrating arm are connected to each other, and by applying an alternating voltage to them, the vibrating arms 43 and 43 are mutually connected. Vibrates in the direction of approaching or moving away.

図４は、図３の右側の振動腕４３が図中左向きに屈曲したときに、その表面に発生する表面電荷分布を示している。第１溝部４７の側面４７ａには、前記錘部への延長部分の側面４７ｂを含む全長に亘って正（＋）の表面電荷が発生した。腕部４４の両側面４４ａ、錘部４５の第２溝部４８の前記第１溝部に隣接する側面、及び第１溝部４７の該錘部への延長部分に対応する範囲にある内側の側面４５ａには、負（−）の表面電荷が発生した。これら以外の錘部４５の部分は、表面電荷が発生しなかった。前記各側面の表面電荷密度は、いずれも基端側が高く、先端側が低かった。振動腕４３が逆向きに屈曲すると、その表面に発生する表面電荷は、極性が反転する。   FIG. 4 shows a surface charge distribution generated on the surface of the right vibrating arm 43 of FIG. 3 when bent to the left in the drawing. A positive (+) surface charge was generated on the side surface 47a of the first groove portion 47 over the entire length including the side surface 47b of the portion extending to the weight portion. On both side surfaces 44a of the arm portion 44, the side surface of the second groove portion 48 of the weight portion 45 adjacent to the first groove portion, and the inner side surface 45a in the range corresponding to the extended portion of the first groove portion 47 to the weight portion. Produced a negative (-) surface charge. In other parts of the weight portion 45, no surface charge was generated. The surface charge density of each of the side surfaces was high on the base end side and low on the front end side. When the vibrating arm 43 is bent in the opposite direction, the polarity of the surface charge generated on the surface is reversed.

このように振動腕４３は、その屈曲振動により表面電荷が発生する領域が、第１溝部４７を錘部４５の領域まで延長させ、前記錘部の突出部分４６に第２溝部４８を設け、かつ前記錘部の他方の振動腕に隣接する側面４５ａを腕部の側面と同一面に形成することによって、錘部４５まで拡大されている。その結果、振動腕４３の励振に貢献する第１及び第２励振電極４９，５０ａ，５０ｂを、腕部４４だけでなく、錘部４５の領域にも形成することができる。本実施例の圧電振動片４１は、第１実施例に比して錘部の質量効果は幾分低減するが、第１実施例と同様に、小型化の要求に対応して振動腕を短くしても、励振電極の面積を大きくして励振効率を高めることができるので、ＣＩ値を低減させることができる。   Thus, the vibrating arm 43 has a region where surface charges are generated by bending vibration thereof, the first groove portion 47 extending to the region of the weight portion 45, a second groove portion 48 is provided in the protruding portion 46 of the weight portion, and The side surface 45a adjacent to the other vibrating arm of the weight portion is formed on the same surface as the side surface of the arm portion, so that the weight portion 45 is enlarged. As a result, the first and second excitation electrodes 49, 50 a, 50 b that contribute to the excitation of the vibrating arm 43 can be formed not only in the arm portion 44 but also in the region of the weight portion 45. The piezoelectric vibrating piece 41 of the present embodiment reduces the mass effect of the weight part somewhat compared to the first embodiment, but shortens the vibrating arm in response to the demand for miniaturization, as in the first embodiment. However, since the excitation efficiency can be increased by increasing the area of the excitation electrode, the CI value can be reduced.

図５（Ａ）〜（Ｃ）は、本発明による音叉型圧電振動片の第３実施例を概略的に示している。本実施例の音叉型圧電振動片５１は第２実施例の変形例であり、振動腕４３の錘部４５が、内側即ち他方の振動腕に隣接する側にも、第２励振電極５０ｂを形成した側面４５ａよりも先端側でかつ該側面から幅方向に突出する部分５２を更に有する点において、第２実施例と異なる。このように追加の突出部分５２を設けることによって、圧電振動片５１は、第２実施例に比して、突出部分５２を追加した分だけ、両振動腕の間隔を拡げなければならないが、より高い質量効果が得られると共に、振動腕４３の長手方向の中心線に関して左右のバランスを改善することができる。   FIGS. 5A to 5C schematically show a third embodiment of a tuning-fork type piezoelectric vibrating piece according to the present invention. The tuning fork type piezoelectric vibrating piece 51 of the present embodiment is a modification of the second embodiment, and the weight portion 45 of the vibrating arm 43 forms the second excitation electrode 50b on the inner side, that is, on the side adjacent to the other vibrating arm. The second embodiment is different from the second embodiment in that it further includes a portion 52 that protrudes in the width direction from the side surface than the side surface 45a. By providing the additional protruding portion 52 in this way, the piezoelectric vibrating piece 51 needs to increase the distance between the vibrating arms by the amount of the additional protruding portion 52 as compared with the second embodiment. A high mass effect can be obtained, and the left / right balance with respect to the longitudinal center line of the vibrating arm 43 can be improved.

図６は、図５の右側の振動腕４３が図中左向きに屈曲したときに、その表面に発生する表面電荷分布を示している。第２実施例と同様に、第１溝部４７の側面４７ａには、前記錘部への延長部分の側面４７ｂを含む全長に亘って正（＋）の表面電荷が発生した。腕部４４の両側面、錘部４５の第２溝部４８の前記第１溝部に隣接する側面、及び第１溝部４７の延長部分に対応する範囲にある内側の側面４５ａには、負（−）の表面電荷が発生した。これら以外の錘部４５の部分は、表面電荷が発生しなかった。前記各側面の表面電荷密度は、いずれも基端側が高く、先端側が低かった。振動腕４３が逆向きに屈曲すると、その表面に発生する表面電荷は、極性が反転する。   FIG. 6 shows a surface charge distribution generated on the surface of the right vibrating arm 43 of FIG. 5 when bent to the left in the drawing. As in the second embodiment, a positive (+) surface charge was generated on the side surface 47a of the first groove portion 47 over the entire length including the side surface 47b of the portion extending to the weight portion. Negative (-) is present on both side surfaces of the arm portion 44, the side surface of the second groove portion 48 of the weight portion 45 adjacent to the first groove portion, and the inner side surface 45a in the range corresponding to the extended portion of the first groove portion 47. Surface charge was generated. In other parts of the weight portion 45, no surface charge was generated. The surface charge density of each of the side surfaces was high on the base end side and low on the front end side. When the vibrating arm 43 is bent in the opposite direction, the polarity of the surface charge generated on the surface is reversed.

本実施例も、振動腕４３は、その屈曲振動により表面電荷が発生する領域が錘部４５まで拡大され、その励振に貢献する第１及び第２励振電極４９，５０ａ，５０ｂを、腕部４４及び錘部４５の領域にも形成することができる。従って、圧電振動片５１は、第２実施例と同様に、小型化の要求に対応して振動腕を短くしても、励振電極の面積を大きくして励振効率を高めることができるので、ＣＩ値を低減させることができる。   Also in this embodiment, the vibrating arm 43 has a region where surface charges are generated by the bending vibration expanded to the weight portion 45, and the first and second excitation electrodes 49, 50 a, 50 b contributing to the excitation are connected to the arm portion 44. It can also be formed in the region of the weight portion 45. Therefore, as in the second embodiment, the piezoelectric vibrating piece 51 can increase the excitation efficiency by increasing the area of the excitation electrode even if the vibrating arm is shortened in response to the demand for miniaturization. The value can be reduced.

図７（Ａ）〜（Ｃ）は、本発明による音叉型圧電振動片の第４実施例を概略的に示している。本実施例の音叉型圧電振動片６１は、第３実施例の変形例であり、振動腕４３の錘部４５には、突出部分５２から基部側の側面即ち第２励振電極５０ｂが形成された内側の側面４５ａに突条６２が設けられている点において、第３実施例と異なる。突条６２は、第２溝部４８の底部に対応する位置に該底部と略同じ厚さに、かつ突出部分５２と同じ幅に形成される。このように突条６２を設けることによって、圧電振動片６１は、錘部４５の内側の側面４５ａに第２励振電極５０ｂの面積を十分に確保しつつ、両振動腕の間隔を更に拡げることなく、錘部に更に質量を付加し、かつ第３実施例に比して、振動腕４３の長手方向の中心線に関して左右のバランスをより改善することができる。   7A to 7C schematically show a fourth embodiment of a tuning-fork type piezoelectric vibrating piece according to the present invention. The tuning-fork type piezoelectric vibrating piece 61 of the present embodiment is a modification of the third embodiment, and the weight 45 of the vibrating arm 43 is formed with a side surface on the base side from the protruding portion 52, that is, the second excitation electrode 50b. The third embodiment is different from the third embodiment in that the protrusion 62 is provided on the inner side surface 45a. The protrusion 62 is formed at a position corresponding to the bottom of the second groove 48 with substantially the same thickness as the bottom and the same width as the protruding portion 52. By providing the protrusion 62 in this way, the piezoelectric vibrating piece 61 can secure a sufficient area of the second excitation electrode 50b on the side surface 45a on the inner side of the weight portion 45 without further increasing the distance between both vibrating arms. Further, mass can be further added to the weight portion, and the left and right balance can be further improved with respect to the center line in the longitudinal direction of the vibrating arm 43 as compared with the third embodiment.

図８は、図７の右側の振動腕４３が図中左向きに屈曲したときに、その表面に発生する表面電荷分布を示している。第３実施例と同様に、第１溝部４７の側面４７ａには、前記錘部への延長部分の側面４７ｂを含む全長に亘って正（＋）の表面電荷が発生した。腕部４４の両側面４４ａ、錘部４５の第２溝部４８の前記第１溝部に隣接する側面、及び第１溝部４７の延長部分に対応する範囲の突条６２を除く内側の側面４５ａには、負（−）の表面電荷が発生した。これら以外の錘部４５の部分は、表面電荷が発生しなかった。前記各側面の表面電荷密度は、いずれも基端側が高く、先端側が低かった。振動腕４３が逆向きに屈曲すると、その表面に発生する表面電荷は、極性が反転する。   FIG. 8 shows a surface charge distribution generated on the surface of the right vibrating arm 43 of FIG. 7 when bent to the left in the drawing. As in the third embodiment, a positive (+) surface charge was generated on the side surface 47a of the first groove portion 47 over the entire length including the side surface 47b of the portion extending to the weight portion. The side surface 44a of the arm portion 44, the side surface adjacent to the first groove portion of the second groove portion 48 of the weight portion 45, and the inner side surface 45a excluding the protrusion 62 in the range corresponding to the extended portion of the first groove portion 47 are A negative (−) surface charge was generated. In other parts of the weight portion 45, no surface charge was generated. The surface charge density of each of the side surfaces was high on the base end side and low on the front end side. When the vibrating arm 43 is bent in the opposite direction, the polarity of the surface charge generated on the surface is reversed.

本実施例も、振動腕４３は、その屈曲振動により表面電荷が発生する領域が錘部４５まで拡大され、その励振に貢献する第１及び第２励振電極４９，５０ａ，５０ｂを、腕部４４及び錘部４５の領域にも形成することができる。従って、圧電振動片６１は、第２実施例と同様に、小型化の要求に対応して振動腕を短くしても、励振電極の面積を大きくして励振効率を高めることができるので、ＣＩ値を低減させることができる。   Also in this embodiment, the vibrating arm 43 has a region where surface charges are generated by the bending vibration expanded to the weight portion 45, and the first and second excitation electrodes 49, 50 a, 50 b contributing to the excitation are connected to the arm portion 44. It can also be formed in the region of the weight portion 45. Accordingly, the piezoelectric vibrating piece 61 can increase the excitation efficiency by increasing the area of the excitation electrode even if the vibrating arm is shortened in response to the demand for miniaturization, as in the second embodiment. The value can be reduced.

図９（Ａ）〜（Ｃ）は、本発明による音叉型圧電振動片の第５実施例を概略的に示している。本実施例の音叉型圧電振動片７１は、第２実施例の別の変形例であり、振動腕４３の錘部４５は、突出部分４６の第２溝部が省略されている点において、第２実施例と異なる。本実施例は、第２実施例に比して、錘部４５に第２溝部及びその内面の第１電極を形成する工程を省略できるので、工数を少なくし、製造コストを低減することができる。   FIGS. 9A to 9C schematically show a fifth embodiment of a tuning-fork type piezoelectric vibrating piece according to the present invention. The tuning fork type piezoelectric vibrating piece 71 of the present embodiment is another modification of the second embodiment, and the weight portion 45 of the vibrating arm 43 is the second in that the second groove portion of the protruding portion 46 is omitted. Different from the embodiment. Since the present embodiment can omit the step of forming the second groove portion and the first electrode on the inner surface of the weight portion 45 as compared with the second embodiment, the number of steps can be reduced and the manufacturing cost can be reduced. .

第１溝部４７の内面には、前記錘部への延長部分を含む全長に亘って第１励振電極４９が形成されている。第１励振電極５０ａは、腕部４４の外側即ち他方の振動腕とは反対側の側面にのみ形成されている。第２励振電極５０ｂは、第２実施例と同様に、腕部４４の内側即ち他方の振動腕に隣接する側面及び、錘部４５の第１溝部４７の延長部分に対応する範囲にある内側の側面４５ａに連続して形成されている。また、第２溝部を省略したことによって、第１溝部４７の前記錘部への延長部分は、外側の側面即ち他方の振動腕とは反対側の側面に第１励振電極４９を設けなくても良い。   A first excitation electrode 49 is formed on the inner surface of the first groove portion 47 over the entire length including the extension portion to the weight portion. The first excitation electrode 50a is formed only on the outer side of the arm portion 44, that is, only on the side surface opposite to the other vibrating arm. Similarly to the second embodiment, the second excitation electrode 50b is formed on the inner side of the arm portion 44, that is, on the side surface adjacent to the other vibrating arm and on the inner side in the range corresponding to the extended portion of the first groove portion 47 of the weight portion 45. It is formed continuously on the side surface 45a. Further, by omitting the second groove portion, the extension portion of the first groove portion 47 to the weight portion does not have to be provided with the first excitation electrode 49 on the outer side surface, that is, the side surface opposite to the other vibrating arm. good.

図１０は、図９の右側の振動腕４３が図中左向きに屈曲したときに、その表面に発生する表面電荷分布を示している。第２実施例と同様に、腕部４４の両側面４４ａ、及び錘部４５の第１溝部４７の延長部分に対応する範囲にある内側の側面４５ａには、負（−）の表面電荷が発生した。これ以外の錘部４５の部分は、表面電荷が発生しなかった。第１溝部４７の内部は、腕部４４の範囲にある内側及び外側の側面に全長に亘って正（＋）の表面電荷が発生したが、前記錘部４５への延長部分では、内側の側面にのみ正（＋）の表面電荷が発生し、外側の側面４７ｂに表面電荷が発生しなかった。前記各側面の表面電荷密度は、いずれも基端側が高く、先端側が低かった。振動腕４３が逆向きに屈曲すると、その表面に発生する表面電荷は、極性が反転する。   FIG. 10 shows a surface charge distribution generated on the surface of the right vibrating arm 43 of FIG. 9 when bent to the left in the figure. As in the second embodiment, negative (−) surface charges are generated on both side surfaces 44a of the arm portion 44 and the inner side surface 45a in the range corresponding to the extended portion of the first groove portion 47 of the weight portion 45. did. In other portions of the weight portion 45, no surface charge was generated. In the first groove portion 47, positive (+) surface charges are generated over the entire length on the inner and outer side surfaces in the range of the arm portion 44, but in the extended portion to the weight portion 45, the inner side surface A positive (+) surface charge was generated only on the surface, and no surface charge was generated on the outer side surface 47b. The surface charge density of each of the side surfaces was high on the base end side and low on the front end side. When the vibrating arm 43 is bent in the opposite direction, the polarity of the surface charge generated on the surface is reversed.

本実施例も、振動腕４３は、その屈曲振動により表面電荷が発生する領域が、上記各実施例よりも少ないが、従来技術に比して錘部４５の領域まで拡大され、その励振に貢献する第１及び第２励振電極４９，５０ｂを、腕部４４及び錘部４５の領域にも形成することができる。従って、圧電振動片７１は、第２実施例と同様に、小型化の要求に対応して振動腕を短くしても、励振電極の面積を大きくして励振効率を高めることができるので、ＣＩ値を低減させることができる。   In this embodiment as well, the vibration arm 43 has a region where surface charges are generated due to its bending vibration, which is smaller than that in each of the embodiments described above, but is expanded to the region of the weight portion 45 as compared with the prior art and contributes to the excitation. The first and second excitation electrodes 49 and 50b can be formed also in the region of the arm portion 44 and the weight portion 45. Therefore, as in the second embodiment, the piezoelectric vibrating piece 71 can increase the excitation efficiency by increasing the area of the excitation electrode even if the vibrating arm is shortened in response to the demand for miniaturization. The value can be reduced.

本発明は、上記実施例に限定されるものでなく、その技術的範囲内で様々な変形又は変更を加えて実施することができる。例えば、振動腕の第１溝部及び第２溝部は、その先端又は先端付近まで延長させることができ、振動腕の表面又は裏面の一方にのみ形成しても良い。また、第１溝部は、腕部の全長に亘って設けなくてもよく、腕部の長手方向に沿って短くしたり途中で分断させることもできる。更に第１励振電極も、第１溝部の全長に亘って設けなくてもよく、その長手方向に短くしたり途中で分断させることもできる。上記実施例は、いずれも音叉型振動片について説明したが、屈曲振動モードで振動する１本以上の振動腕を有する限り、それ以外の様々な圧電デバイスについて適用することができる。   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 first groove portion and the second groove portion of the vibrating arm can be extended to the tip or the vicinity of the tip, and may be formed only on one of the front surface or the back surface of the vibrating arm. Further, the first groove portion does not have to be provided over the entire length of the arm portion, and can be shortened along the longitudinal direction of the arm portion or divided in the middle. Furthermore, the first excitation electrode may not be provided over the entire length of the first groove portion, and may be shortened in the longitudinal direction or divided in the middle. In the above-described embodiments, the tuning fork type vibrating piece has been described. However, as long as one or more vibrating arms that vibrate in the bending vibration mode are provided, the present invention can be applied to various other piezoelectric devices.

１，１１，２１，４１，５１，６１，７１…圧電振動片、２，１２，２２，４２…基部、３，１３，２３，４３…振動腕、４，１４，２４，４４…腕部、４ａ，６ａ，１４ａ，１６ａ，２４ａ，２７ａ，２７ｂ，２８ａ，４４ａ，４５ａ，４７ａ，４７ｂ…側面、５，１５，２５，４５…錘部、６，１６…溝部、７，１７，２９，４９…第１励振電極、８，１８，３０，５０ａ，５０ｂ…第２励振電極、９，１９…接続電極、２６，４６，５２…突出部分、２７，４７…第１溝部、２８，４８…第２溝部、６２…突条。 1,11,21,41,51,61,71 ... piezoelectric vibrating piece, 2,12,22,42 ... base, 3,13,23,43 ... vibrating arm, 4,14,24,44 ... arm 4a, 6a, 14a, 16a, 24a, 27a, 27b, 28a, 44a, 45a, 47a, 47b ... side surfaces, 5, 15, 25, 45 ... weight parts, 6, 16 ... groove parts, 7, 17, 29, 49 ... 1st excitation electrode, 8, 18, 30, 50a, 50b ... 2nd excitation electrode, 9, 19 ... Connection electrode, 26, 46, 52 ... Projection part, 27, 47 ... 1st groove part, 28, 48 ... 1st 2 groove part, 62 ... protrusion.

Claims (6)

基部と、前記基部から延出しかつ屈曲振動モードで振動する振動腕とを備え、
前記振動腕が、前記基部に結合した所定の幅の腕部と、その幅方向に前記腕部の側面から突出する部分を有するように振動腕先端に形成した広幅の錘部とからなり、
前記振動腕の表面及び裏面の少なくとも一方にその長手方向に沿って形成された第１溝部と、前記第１溝部の側面に形成した第１励振電極と、前記振動腕の側面に形成した第２励振電極とを有し、
前記第１溝部が、前記腕部から前記錘部の領域まで延長するように設けられ、
前記錘部が、その幅方向の少なくとも一方の側に、前記第１溝部の側面と平行に延長しかつ前記腕部の側面から連続してそれと同一面をなす側面を有し、
前記第２励振電極が、前記腕部の側面と該側面に連続する前記錘部の側面とに連続して形成されていることを特徴とする圧電振動片。 A base and a vibrating arm that extends from the base and vibrates in a flexural vibration mode;
The vibrating arm includes an arm portion having a predetermined width coupled to the base portion, and a wide weight portion formed at the tip of the vibrating arm so as to have a portion protruding from a side surface of the arm portion in the width direction thereof.
A first groove formed along the longitudinal direction on at least one of the front and back surfaces of the vibrating arm, a first excitation electrode formed on a side surface of the first groove, and a second groove formed on a side surface of the vibrating arm. An excitation electrode,
The first groove portion is provided so as to extend from the arm portion to the region of the weight portion,
The weight portion has a side surface extending parallel to the side surface of the first groove portion and continuously extending from the side surface of the arm portion on at least one side in the width direction;
The piezoelectric vibrating piece, wherein the second excitation electrode is continuously formed on a side surface of the arm portion and a side surface of the weight portion continuous with the side surface. 前記基部から平行に延長する１対の前記振動腕を有する音叉型であることを特徴とする請求項１記載の圧電振動片。   The piezoelectric vibrating piece according to claim 1, wherein the piezoelectric vibrating piece is a tuning fork type having a pair of the vibrating arms extending in parallel from the base. 前記錘部の前記腕部の側面から連続して同一面をなす側面が、前記錘部の幅方向の前記突出部分に前記第１溝部と平行に形成した、有底の第２溝部の側面からなることを特徴とする請求項１または２記載の圧電振動片。   From the side surface of the bottomed second groove portion, the side surface continuously forming the same surface from the side surface of the arm portion of the weight portion is formed in the protruding portion in the width direction of the weight portion in parallel with the first groove portion. The piezoelectric vibrating piece according to claim 1, wherein: 前記錘部の前記腕部の側面から連続して同一面をなす側面が、前記錘部の幅方向の前記突出部分を有しない側の側面からなることを特徴とする請求項１乃至３のいずれか記載の圧電振動片。   The side surface which makes the same surface continuously from the side surface of the arm portion of the weight portion is a side surface which does not have the protruding portion in the width direction of the weight portion. Or a piezoelectric vibrating piece. 前記錘部が、その幅方向の一方の側に腕部の側面から突出する前記部分を有し、かつ幅方向の他方の側に、前記基部側に前記腕部の側面から連続してそれと同一面をなす前記側面と、該側面から幅方向に突出する追加の部分とを有することを特徴とする請求項１乃至４のいずれか記載の圧電振動片。   The weight portion has the portion protruding from the side surface of the arm portion on one side in the width direction, and is the same as that on the other side in the width direction continuously from the side surface of the arm portion on the base side. 5. The piezoelectric vibrating piece according to claim 1, comprising the side surface forming a surface and an additional portion protruding in the width direction from the side surface. 前記錘部が、前記腕部の側面から連続してそれと同一面をなす前記側面に、前記追加の突出部分から前記基部側に向けて延長する突条を有することを特徴とする請求項５記載の圧電振動片。   The said weight part has the protruding item | line extended from the said additional protrusion part toward the said base part side in the said side surface which makes the same surface as it continuously from the side surface of the said arm part. Piezoelectric vibrating piece.
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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014179803A (en) * 2013-03-14 2014-09-25 Seiko Epson Corp Vibration element, vibrator, oscillator, electronic apparatus and mobile
US9214919B2 (en) 2013-03-29 2015-12-15 Seiko Epson Corporation Resonator element, resonator, oscillator, electronic apparatus, and moving object
JP2016133427A (en) * 2015-01-20 2016-07-25 京セラクリスタルデバイス株式会社 Sensor element and angular velocity sensor
JP2017098911A (en) * 2015-11-28 2017-06-01 京セラクリスタルデバイス株式会社 Tuning-fork type crystal element
JP2018152911A (en) * 2018-06-05 2018-09-27 セイコーエプソン株式会社 Vibration element, vibrator, oscillator, electronic apparatus, and mobile body
JP2019115079A (en) * 2019-04-22 2019-07-11 セイコーエプソン株式会社 Vibration element, vibrator, oscillator, electronic apparatus, and mobile body
US11990890B2 (en) 2018-09-13 2024-05-21 Murata Manufacturing Co., Ltd. Resonator and resonance device including same

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5437488A (en) * 1977-07-20 1979-03-19 Seiko Epson Corp Tuning fork type crystal oscillator
JPS5453889A (en) * 1977-10-06 1979-04-27 Seiko Instr & Electronics Ltd Piezoelectric vibrator and its temperature characteristic adjusting method
JPS6458108A (en) * 1987-08-28 1989-03-06 Matsushima Kogyo Kk Tuning fork type crystal vibrator
JPH05129875A (en) * 1991-11-08 1993-05-25 Seiko Electronic Components Ltd Torsional crystal vibrator
JP2004282230A (en) * 2003-03-13 2004-10-07 Seiko Epson Corp Piezoelectric oscillating piece, piezoelectric device using this, portable telephone using this and electronic apparatus
JP2004333416A (en) * 2003-05-12 2004-11-25 Ngk Insulators Ltd Apparatus for measuring physical quantity
JP2005005896A (en) * 2003-06-10 2005-01-06 Seiko Epson Corp Piezoelectric oscillating piece, method for manufacturing piezoelectric oscillating piece, piezoelectric oscillator and electronic equipment mounted with piezoelectric oscillator
JP2009027711A (en) * 2007-07-19 2009-02-05 Eta Sa Manufacture Horlogere Suisse Piezoelectric resonator with optimized motional capacitances

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5437488A (en) * 1977-07-20 1979-03-19 Seiko Epson Corp Tuning fork type crystal oscillator
JPS5453889A (en) * 1977-10-06 1979-04-27 Seiko Instr & Electronics Ltd Piezoelectric vibrator and its temperature characteristic adjusting method
JPS6458108A (en) * 1987-08-28 1989-03-06 Matsushima Kogyo Kk Tuning fork type crystal vibrator
JPH05129875A (en) * 1991-11-08 1993-05-25 Seiko Electronic Components Ltd Torsional crystal vibrator
JP2004282230A (en) * 2003-03-13 2004-10-07 Seiko Epson Corp Piezoelectric oscillating piece, piezoelectric device using this, portable telephone using this and electronic apparatus
JP2004333416A (en) * 2003-05-12 2004-11-25 Ngk Insulators Ltd Apparatus for measuring physical quantity
JP2005005896A (en) * 2003-06-10 2005-01-06 Seiko Epson Corp Piezoelectric oscillating piece, method for manufacturing piezoelectric oscillating piece, piezoelectric oscillator and electronic equipment mounted with piezoelectric oscillator
JP2009027711A (en) * 2007-07-19 2009-02-05 Eta Sa Manufacture Horlogere Suisse Piezoelectric resonator with optimized motional capacitances

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014179803A (en) * 2013-03-14 2014-09-25 Seiko Epson Corp Vibration element, vibrator, oscillator, electronic apparatus and mobile
US9654083B2 (en) 2013-03-14 2017-05-16 Seiko Epson Corporation Resonator element having a pair of vibrating arms with wide portions and arm portions
CN109067379A (en) * 2013-03-14 2018-12-21 精工爱普生株式会社 Vibrating elements, oscillator, oscillator, electronic equipment and moving body
CN109067379B (en) * 2013-03-14 2022-05-17 精工爱普生株式会社 Resonator element, resonator, oscillator, electronic apparatus, and moving object
US9214919B2 (en) 2013-03-29 2015-12-15 Seiko Epson Corporation Resonator element, resonator, oscillator, electronic apparatus, and moving object
JP2016133427A (en) * 2015-01-20 2016-07-25 京セラクリスタルデバイス株式会社 Sensor element and angular velocity sensor
JP2017098911A (en) * 2015-11-28 2017-06-01 京セラクリスタルデバイス株式会社 Tuning-fork type crystal element
JP2018152911A (en) * 2018-06-05 2018-09-27 セイコーエプソン株式会社 Vibration element, vibrator, oscillator, electronic apparatus, and mobile body
US11990890B2 (en) 2018-09-13 2024-05-21 Murata Manufacturing Co., Ltd. Resonator and resonance device including same
JP2019115079A (en) * 2019-04-22 2019-07-11 セイコーエプソン株式会社 Vibration element, vibrator, oscillator, electronic apparatus, and mobile body

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