JPH08154032A - Piezoelectric resonator - Google Patents
Piezoelectric resonatorInfo
- Publication number
- JPH08154032A JPH08154032A JP29443394A JP29443394A JPH08154032A JP H08154032 A JPH08154032 A JP H08154032A JP 29443394 A JP29443394 A JP 29443394A JP 29443394 A JP29443394 A JP 29443394A JP H08154032 A JPH08154032 A JP H08154032A
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- Prior art keywords
- rectangular
- excitation electrodes
- electrodes
- excitation
- piezoelectric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は厚み縦エネルギー閉じ込
め形共振子を用いた圧電共振子に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonator using a thickness longitudinal energy trap type resonator.
【０００２】[0002]
【従来の技術】圧電セラミック、圧電単結晶等を用いた
フィルタ、発振子等の圧電共振子のうち、これらが使用
される中心周波数、発振周波数がほぼ１ＭHz以上のもの
では、電気的共振周波数が第一義的に圧電共振子の厚さ
（ｔ）に逆比例する厚み振動モードが広く用いられてい
る。特に中心周波数、発振周波数が高い周波数の圧電共
振子ではバルク波の音速が厚みすべり振動の約２倍ある
厚み縦振動が利用されている。2. Description of the Related Art Among piezoelectric resonators, such as filters using piezoelectric ceramics, piezoelectric single crystals, and oscillators, those having a center frequency and an oscillation frequency of about 1 MHz or more have electrical resonance frequencies. A thickness vibration mode that is inversely proportional to the thickness (t) of the piezoelectric resonator is widely used. In particular, in a piezoelectric resonator having a high center frequency and a high oscillation frequency, thickness longitudinal vibration having a sound velocity of a bulk wave about twice that of thickness shear vibration is used.
【０００３】図３（ａ），（ｂ）は従来の厚み縦振動を
利用した圧電共振子を示すものである。図３（ａ），
（ｂ）において１は圧電セラミック等を用いた圧電基
板、２は圧電基板１の表面に配置された励振用電極、３
は圧電基板１の裏面に励振用電極２と対向して表裏一対
となるように配置された励振用電極、４は外部端子と励
振用電極２，３を電気的に結びつけるための引き出し電
極であり、励振用電極２と３は、厚み縦モードの振動が
等方性の広がりを持つことから円形とし、その直径はオ
ーバートーンが生じないようベックマン定数で決まる値
以下とし、圧電基板１の輪郭寸法のいずれも励振用電極
２，３より大きくしてあり、励振用電極２，３は圧電基
板１の主平面上の１部分にしか形成されていない部分電
極とすることで、不要共振応答のない安定した共振特性
を得ることができるように構成されていた。3 (a) and 3 (b) show a conventional piezoelectric resonator utilizing thickness longitudinal vibration. Figure 3 (a),
In (b), 1 is a piezoelectric substrate using a piezoelectric ceramic or the like, 2 is an excitation electrode arranged on the surface of the piezoelectric substrate 1, 3
Is an excitation electrode arranged on the back surface of the piezoelectric substrate 1 so as to face the excitation electrode 2 so as to form a pair of front and back surfaces, and 4 is an extraction electrode for electrically connecting an external terminal and the excitation electrodes 2 and 3. , The excitation electrodes 2 and 3 are circular because the vibration in the thickness longitudinal mode has an isotropic spread, and the diameter thereof is not more than the value determined by the Beckman constant so that overtone does not occur, and the contour dimension of the piezoelectric substrate 1 Both of them are larger than the excitation electrodes 2 and 3, and the excitation electrodes 2 and 3 are partial electrodes formed only in one part on the main plane of the piezoelectric substrate 1, so that there is no unnecessary resonance response. It was configured so that stable resonance characteristics could be obtained.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら上記の従
来の構成では、厚み縦基本モードで２０ＭHz以上、厚み
縦３倍モードで６０ＭHz以上では、励振用電極２，３の
直径をオーバートーンが生じない値以下とすると、圧電
共振子の共振抵抗が大きくなってしまい、また励振用電
極２，３の直径が小さくなるため引き出し電極４の影響
が無視できなくなり、表裏対向する励振用電極２，３に
発生する電界が厚み方向に対して対称でなくなるため等
方性の広がりを持つ厚み縦モードの振動を阻害するた
め、共振波形に不要共振応答が入るという問題点を有し
ていた。However, in the above-mentioned conventional configuration, the diameter of the excitation electrodes 2 and 3 is a value at which overtone does not occur at a thickness longitudinal basic mode of 20 MHz or more and a thickness longitudinal triple mode of 60 MHz or more. In the following case, the resonance resistance of the piezoelectric resonator becomes large, and the diameter of the excitation electrodes 2 and 3 becomes small, so that the influence of the extraction electrode 4 cannot be ignored and occurs in the excitation electrodes 2 and 3 facing each other. Since the generated electric field is not symmetric with respect to the thickness direction, vibration of the thickness longitudinal mode having an isotropic spread is hindered, and there is a problem that an unnecessary resonance response is included in the resonance waveform.
【０００５】本発明は上記従来の問題点を解決するもの
で、従来より高周波の領域で高性能な圧電共振子を提供
することを目的とする。The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a piezoelectric resonator having high performance in a high frequency region as compared with the prior art.
【０００６】[0006]
【課題を解決するための手段】この目的を達成するため
に本発明は、圧電基板の主平面上に表裏交差する矩形型
励振用電極を２対設け、前記のうち表面の２個の矩形型
励振用電極に外部から電界を印加するための引き出し電
極を接続し、裏面の２個の矩形型励振用電極を電気的に
接続し、前記圧電基板の表裏で交差している矩形型励振
用電極の交差角度を７０〜１１０度とし、裏面の矩形型
励振用電極の表面の矩形型励振用電極と交差していない
部分の長さを交差している幅の０．５〜１．０倍とした
ものである。In order to achieve this object, the present invention provides two pairs of rectangular-shaped excitation electrodes that intersect each other on the main plane of a piezoelectric substrate, and two of the above-mentioned rectangular-shaped electrodes on the surface are provided. A rectangular excitation electrode is connected to the excitation electrode for external application of an electric field, electrically connected to the two rectangular excitation electrodes on the back surface, and intersects on the front and back sides of the piezoelectric substrate. Is set to 70 to 110 degrees, and the length of the portion of the back surface of the rectangular excitation electrode that does not intersect the front surface of the rectangular excitation electrode is set to 0.5 to 1.0 times the intersecting width. It was done.
【０００７】[0007]
【作用】この構成によって、圧電共振子の共振抵抗は、
圧電基板に励振部分が１対あるときより低くなり、また
励振部分で発生する電界は厚み方向に対してほぼ対称性
を持つものとなり等方性の広がりを持つ厚み縦モードの
振動を阻害しなくなるため、不要共振応答を極めて小さ
くできることになる。With this configuration, the resonance resistance of the piezoelectric resonator is
It becomes lower than when there is a pair of excitation parts on the piezoelectric substrate, and the electric field generated in the excitation part has almost symmetry with respect to the thickness direction and does not hinder the vibration of the thickness longitudinal mode having an isotropic spread. Therefore, the unnecessary resonance response can be made extremely small.
【０００８】[0008]
【実施例】以下本発明の一実施例について、図面を参照
にしながら説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
【０００９】図１（ａ）は本発明による圧電共振子の表
側を示す平面図、同図１（ｂ）はその裏側を示すもので
ある。圧電基板５は厚み方向に分極された圧電セラミッ
ク基板であり厚さｔで決まる厚み縦基本モードが非閉じ
込め（伝搬）モード、厚み縦３倍モードがエネルギー閉
じ込めモードとなるような定数（ポアソン比）をもって
いる。本実施例では分極処理された圧電基板５を用いた
が、本発明の適用範囲はこれに限定されるものではなく
自発分極を持つ圧電単結晶、配向膜等を用いることがで
きる。FIG. 1 (a) is a plan view showing the front side of a piezoelectric resonator according to the present invention, and FIG. 1 (b) shows the back side thereof. The piezoelectric substrate 5 is a piezoelectric ceramic substrate polarized in the thickness direction, and a constant (Poisson's ratio) such that the thickness longitudinal fundamental mode determined by the thickness t becomes a non-confinement (propagation) mode and the thickness longitudinal triple mode becomes an energy confinement mode. I have Although the piezoelectric substrate 5 that has been polarized is used in this embodiment, the scope of application of the present invention is not limited to this, and a piezoelectric single crystal having spontaneous polarization, an orientation film, or the like can be used.
【００１０】６，７は圧電基板５の表面に圧電基板５の
中心に対して対称となるよう配置された矩形型励振用電
極、８，９は圧電基板５の裏面に励振用電極６，７とそ
れぞれ対向して表裏一対となるように配置された矩形型
励振用電極、１０は矩形型励振用電極８と９を電気的に
結びつけるための接続電極、１１は矩形型励振用電極
６，７を外部端子と電気的に接続する引き出し電極であ
る。Reference numerals 6 and 7 denote rectangular excitation electrodes arranged on the surface of the piezoelectric substrate 5 so as to be symmetrical with respect to the center of the piezoelectric substrate 5. Reference numerals 8 and 9 denote excitation electrodes 6 and 7 on the back surface of the piezoelectric substrate 5. The rectangular excitation electrodes 10 are arranged so as to face each other so as to form a pair of front and back surfaces, 10 is a connection electrode for electrically connecting the rectangular excitation electrodes 8 and 9, and 11 is a rectangular excitation electrode 6, 7. Is an extraction electrode for electrically connecting to the external terminal.
【００１１】また、これらの電極は蒸着で形成し、矩形
型励振用電極６，７，８，９は実施例では、その交差幅
はオーバートーンが生じない電極重なり面積になる値以
下とし、圧電基板５の輪郭寸法のいずれも矩形型励振用
電極６，７，８，９より大きくしてあり、矩形型励振用
電極６，７，８，９は圧電基板５の主平面上の１部分に
しか形成されていない部分電極としている。Further, these electrodes are formed by vapor deposition, and the rectangular excitation electrodes 6, 7, 8 and 9 in the embodiment have a crossing width of not more than a value which is an electrode overlapping area where overtone does not occur, All of the outline dimensions of the substrate 5 are larger than the rectangular excitation electrodes 6, 7, 8 and 9, and the rectangular excitation electrodes 6, 7, 8 and 9 are located in a portion on the main plane of the piezoelectric substrate 5. Only partial electrodes are formed.
【００１２】以上のように構成された圧電共振子につい
て、以下にその動作を説明する。引き出し電極１１に電
圧を印加すると矩形型励振用電極６，７，８，９の間に
電界が発生するが、矩形型励振用電極６，７と８，９の
交差角度θが９０度となっており、矩形型励振用電極
８，９の矩形型励振用電極６，７と交差しない部分の長
さａが矩形型励振用電極８の幅と同じになっているため
矩形型励振用電極６，７と８，９の間発生した電界は厚
み方向に対してほぼ対称性を持つものとなり等方性の広
がりを持つ厚み縦モードの振動を阻害しなくなるため、
圧電基板５の厚みによって決まる共振応答を励振でき、
不要共振応答が極めて小さくなる。The operation of the piezoelectric resonator having the above structure will be described below. When a voltage is applied to the extraction electrode 11, an electric field is generated between the rectangular excitation electrodes 6, 7, 8 and 9, but the intersection angle θ between the rectangular excitation electrodes 6, 7 and 8, 9 becomes 90 degrees. Since the length a of the rectangular excitation electrodes 8 and 9 that does not intersect the rectangular excitation electrodes 6 and 7 is the same as the width of the rectangular excitation electrode 8, the rectangular excitation electrode 6 , 7 and 8 and 9 are almost symmetric with respect to the thickness direction, and do not disturb the vibration of thickness longitudinal mode having isotropic spread.
A resonance response determined by the thickness of the piezoelectric substrate 5 can be excited,
The unnecessary resonance response becomes extremely small.
【００１３】試作した圧電共振子の諸元は次の通りであ
る。 １）使用中心周波数；６５ＭHz ２）矩形型励振用電極６，７，８，９の電極幅；０．２
mm ３）圧電基板５の幅；１．０mm ４）圧電基板５の長さ；４．０mm（補助電極中心） ５）矩形型励振用電極６，７と８，９の交差角度θ；９
０度 ６）矩形型励振用電極８，９の矩形型励振用電極６，７
と交差しない部分の長さａ；０．２mm 図２に本発明に関わる圧電基板５を用いた圧電共振子の
共振周波数近傍の共振応答を実線で示した。破線は従来
の圧電共振子の構成で励振用電極の直径を０．２５mmと
した圧電共振子の共振周波数近傍の共振応答である。こ
れから明らかなように、本発明に関わる圧電共振子は共
振抵抗及び共振周波数近傍の不要共振応答に大きな改善
効果が認められる。The specifications of the prototyped piezoelectric resonator are as follows. 1) Center frequency used; 65 MHz 2) Width of rectangular excitation electrodes 6, 7, 8, 9; 0.2
mm 3) Width of piezoelectric substrate 5; 1.0 mm 4) Length of piezoelectric substrate 5; 4.0 mm (center of auxiliary electrode) 5) Crossing angle θ of rectangular-shaped excitation electrodes 6, 7 and 8, 9;
0 degree 6) Rectangular excitation electrodes 8 and 9 of rectangular excitation electrodes 6 and 7
The length a of the portion not intersecting with; 0.2 mm FIG. 2 shows the resonance response in the vicinity of the resonance frequency of the piezoelectric resonator using the piezoelectric substrate 5 according to the present invention with a solid line. The broken line shows the resonance response in the vicinity of the resonance frequency of the piezoelectric resonator in which the diameter of the excitation electrode is 0.25 mm in the conventional piezoelectric resonator configuration. As is apparent from this, the piezoelectric resonator according to the present invention has a great improvement effect on the resonance resistance and the unnecessary resonance response near the resonance frequency.
【００１４】なお本実施例では矩形型励振用電極６，７
と８，９との交差角度θを９０度とし、矩形型励振用電
極８，９の矩形型励振用電極６，７と交差しない部分の
長さが矩形型励振用電極８の幅の１倍としたが、これら
は圧電基板５の厚みにもよるが、交差角度は７０〜１１
０度、矩形型励振用電極８，９の矩形型励振用電極６，
７と交差しない部分の長さが矩形型励振用電極８の幅の
０．５〜１倍とすることで矩形型励振用電極６，７と
８，９の間に発生した電界は厚み方向に対してほぼ対称
性を持つことができる。In this embodiment, the rectangular excitation electrodes 6 and 7 are used.
The crossing angle θ between the rectangular excitation electrodes 8 and 9 is 90 degrees, and the length of the portion of the rectangular excitation electrodes 8 and 9 that does not intersect the rectangular excitation electrodes 6 and 7 is one time the width of the rectangular excitation electrode 8. However, depending on the thickness of the piezoelectric substrate 5, the crossing angle is 70 to 11
0 degree, rectangular type excitation electrodes 8 and 9 rectangular type excitation electrodes 6,
By setting the length of the portion not intersecting 7 to be 0.5 to 1 times the width of the rectangular excitation electrode 8, the electric field generated between the rectangular excitation electrodes 6, 7 and 8, 9 is applied in the thickness direction. It can have almost symmetry.
【００１５】[0015]
【発明の効果】以上のように本発明は、圧電基板の主平
面上に表裏交差する矩形型励振用電極を２対設け、前記
矩形型励振用電極のうち表面の２個の矩形型励振用電極
に外部から電界を印加するための引き出し電極を接続
し、裏面の２個の矩形型励振用電極を電気的に接続し、
前記圧電基板の表裏で交差する矩形型励振用電極の交差
角度を７０〜１１０度とし、裏面の矩形型励振用電極の
表面の矩形型励振用電極と交差していない部分の長さを
交差している幅の０．５〜１．０倍とすることにより、
従来より高周波の領域で特性を悪化させることなく優れ
た圧電共振子を得ることができる。As described above, according to the present invention, two pairs of rectangular excitation electrodes are provided on the main plane of the piezoelectric substrate so as to intersect with each other, and two rectangular excitation electrodes on the surface of the rectangular excitation electrodes are used. An extraction electrode for applying an electric field from the outside is connected to the electrode, and two rectangular excitation electrodes on the back surface are electrically connected,
The crossing angle of the rectangular excitation electrodes intersecting on the front and back of the piezoelectric substrate is set to 70 to 110 degrees, and the length of the portion of the back surface of the rectangular excitation electrodes that does not intersect with the rectangular excitation electrodes intersects. The width is 0.5 to 1.0 times,
It is possible to obtain an excellent piezoelectric resonator without deteriorating the characteristics in a high frequency region as compared with the related art.
【図１】（ａ）本発明の一実施例の圧電共振子の表側の
平面図 （ｂ）本発明の一実施例の圧電共振子の裏側の平面図1A is a plan view of a front side of a piezoelectric resonator according to an embodiment of the present invention, and FIG. 1B is a plan view of a back side of a piezoelectric resonator according to an embodiment of the present invention.
【図２】本発明と従来の圧電共振子の共振応答特性図FIG. 2 is a resonance response characteristic diagram of the present invention and a conventional piezoelectric resonator.
【図３】（ａ）従来の圧電共振子の表側の平面図 （ｂ）従来の圧電共振子の裏側の平面図FIG. 3 (a) is a plan view of the front side of a conventional piezoelectric resonator, and (b) is a plan view of the back side of a conventional piezoelectric resonator.
５ 圧電基板 ６，７，８，９ 矩形型励振用電極 １０ 接続電極 １１ 引き出し電極 θ 矩形型励振用電極の交差角度 ａ 電極の交差しない部分の長さ 5 Piezoelectric substrate 6, 7, 8, 9 Rectangular excitation electrode 10 Connection electrode 11 Extraction electrode θ Rectangular excitation electrode intersection angle a Length of non-intersecting electrode
Claims (1)
形型励振用電極を２対設け、前記矩形型励振用電極のう
ち表面の２個の矩形型励振用電極に外部から電界を印加
するための引き出し電極を接続し、裏面の２個の矩形型
励振用電極を電気的に接続し、前記圧電基板の表裏で交
差する矩形型励振用電極の交差角度を７０〜１１０度と
し、裏面の矩形型励振用電極の表面の矩形型励振用電極
と交差していない部分の長さを、交差している幅の０．
５〜１．０倍とした圧電共振子。1. A piezoelectric substrate is provided with two pairs of rectangular excitation electrodes on the main plane that intersect each other on the front and back sides, and an electric field is externally applied to the two rectangular excitation electrodes on the surface of the rectangular excitation electrodes. To connect the lead-out electrodes for electrically connecting the two rectangular-shaped excitation electrodes on the back surface, and the crossing angles of the rectangular-shaped excitation electrodes intersecting on the front and back of the piezoelectric substrate are 70 to 110 degrees. The length of the portion of the surface of the rectangular excitation electrode that does not intersect the rectangular excitation electrode is 0.
Piezoelectric resonator made 5 to 1.0 times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29443394A JPH08154032A (en) | 1994-11-29 | 1994-11-29 | Piezoelectric resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29443394A JPH08154032A (en) | 1994-11-29 | 1994-11-29 | Piezoelectric resonator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08154032A true JPH08154032A (en) | 1996-06-11 |
Family
ID=17807711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29443394A Pending JPH08154032A (en) | 1994-11-29 | 1994-11-29 | Piezoelectric resonator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08154032A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6577043B2 (en) | 2000-08-31 | 2003-06-10 | Murata Manufacturing Co., Ltd. | Piezoelectric resonator and electronic device incorporating the same |
| US6621193B1 (en) | 1999-08-26 | 2003-09-16 | Murata Manufacturing Co., Ltd. | Thickness extensional vibration mode piezoelectric resonator, ladder-type filter, and piezoelectric resonator component |
| JP2009089441A (en) * | 2009-01-15 | 2009-04-23 | Epson Toyocom Corp | Piezoelectric vibrating element, piezoelectric vibrator, and piezoelectric oscillator |
-
1994
- 1994-11-29 JP JP29443394A patent/JPH08154032A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6621193B1 (en) | 1999-08-26 | 2003-09-16 | Murata Manufacturing Co., Ltd. | Thickness extensional vibration mode piezoelectric resonator, ladder-type filter, and piezoelectric resonator component |
| US6577043B2 (en) | 2000-08-31 | 2003-06-10 | Murata Manufacturing Co., Ltd. | Piezoelectric resonator and electronic device incorporating the same |
| DE10142158B4 (en) * | 2000-08-31 | 2005-05-04 | Murata Mfg. Co., Ltd., Nagaokakyo | Piezoelectric resonator and electronic device containing same |
| JP2009089441A (en) * | 2009-01-15 | 2009-04-23 | Epson Toyocom Corp | Piezoelectric vibrating element, piezoelectric vibrator, and piezoelectric oscillator |
| JP4640511B2 (en) * | 2009-01-15 | 2011-03-02 | エプソントヨコム株式会社 | Piezoelectric vibration element, piezoelectric vibrator, and piezoelectric oscillator |
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