JPH0426247B2 - - Google Patents
Info
- Publication number
- JPH0426247B2 JPH0426247B2 JP60229364A JP22936485A JPH0426247B2 JP H0426247 B2 JPH0426247 B2 JP H0426247B2 JP 60229364 A JP60229364 A JP 60229364A JP 22936485 A JP22936485 A JP 22936485A JP H0426247 B2 JPH0426247 B2 JP H0426247B2
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- piezoelectric
- piezoelectric thin
- piezoelectric vibrator
- vibration
- 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.)
- Expired - Lifetime
Links
- 239000010409 thin film Substances 0.000 claims description 37
- 239000000758 substrate Substances 0.000 claims description 24
- 239000010408 film Substances 0.000 claims description 17
- 238000013459 approach Methods 0.000 claims description 8
- 239000013013 elastic material Substances 0.000 claims description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 12
- 239000011787 zinc oxide Substances 0.000 description 6
- 235000019687 Lamb Nutrition 0.000 description 5
- 238000005452 bending Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000005284 excitation Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000007769 metal material Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 229910000942 Elinvar Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000003486 chemical etching Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000001947 vapour-phase growth Methods 0.000 description 1
Description
【発明の詳細な説明】
(a) 技術分野
この発明は、エリンバ等からなる振動基板上に
ZnO等の圧電薄膜を形成することにより構成さ
れ、拡がり振動モードを利用する圧電振動子に関
する。[Detailed Description of the Invention] (a) Technical Field This invention provides a vibration substrate made of Erinva or the like.
This invention relates to a piezoelectric vibrator that is constructed by forming a piezoelectric thin film such as ZnO and utilizes a spreading vibration mode.
(b) 従来技術とその欠点
エリンバ等の恒弾性金属材料からなる振動基板
上にZnO等の圧電薄膜を形成した圧電振動子が、
TVのカラー同期用の発振子等としてよく利用さ
れている。これは、このような圧電振動子が圧電
セラミツクスを用いるよりも精度がよく、しかも
水晶を用いるよりも安価に製造できるからであ
る。この圧電振動子の一例を第２図に示す。この
圧電振動子は、振動基板１と圧電薄膜２と電極膜
３とで構成される。振動基板１は、エリンバ等の
恒弾性金属材料からなる方形の薄板である。この
振動基板１は、周囲を額縁状の保持枠４で取り囲
まれ、両短辺の中央部にそれぞれ架設された結合
子５，５によつてこの保持枠４に支持されてい
る。圧電薄膜２は、酸化亜鉛ZnO等の圧電素材
を、振動基板１上にスパツタリング等の方法によ
つて薄膜状に形成したものである。電極膜３は、
圧電薄膜２上に端部を開けて蒸着等の方法により
形成したアルミニウム等の金属薄膜である。(b) Conventional technology and its disadvantages A piezoelectric vibrator in which a piezoelectric thin film such as ZnO is formed on a vibrating substrate made of a constant elastic metal material such as Elinva,
It is often used as an oscillator for TV color synchronization. This is because such a piezoelectric vibrator has better precision than using piezoelectric ceramics, and can be manufactured at a lower cost than using crystal. An example of this piezoelectric vibrator is shown in FIG. This piezoelectric vibrator is composed of a vibrating substrate 1, a piezoelectric thin film 2, and an electrode film 3. The vibration substrate 1 is a rectangular thin plate made of a constant elastic metal material such as Erinba. The vibrating board 1 is surrounded by a frame-shaped holding frame 4, and is supported by the holding frame 4 by connectors 5, 5 installed at the center of both short sides. The piezoelectric thin film 2 is a thin film formed of a piezoelectric material such as zinc oxide ZnO on the vibrating substrate 1 by a method such as sputtering. The electrode film 3 is
It is a metal thin film made of aluminum or the like formed on the piezoelectric thin film 2 with open ends by a method such as vapor deposition.
ところが、拡がり振動モードを利用するこのよ
うな従来の圧電振動子は、第３図に示すように、
圧電薄膜２の略全面を振動基板と電極膜３で挟ん
だ構造として、しかも圧電薄膜２のＣ軸配向６が
中央部と同様に周辺部でも垂直となつているの
で、圧電薄膜２の周辺部での分極による機械的応
力によつて屈曲振動や対称ラム波振動が励起しや
すくなり、このため基本となる拡がり振動以外に
屈曲振動や対称ラム波等のスプリアス成分が発生
して拡がり振動の利用効率を低下させていた。 However, such conventional piezoelectric vibrators that utilize the spreading vibration mode, as shown in Figure 3,
Almost the entire surface of the piezoelectric thin film 2 is sandwiched between the vibrating substrate and the electrode film 3, and since the C-axis orientation 6 of the piezoelectric thin film 2 is vertical in the peripheral part as well as in the central part, the peripheral part of the piezoelectric thin film 2 is Bending vibration and symmetric Lamb wave vibration are easily excited by the mechanical stress caused by polarization in It was reducing efficiency.
(c) 発明の目的
この発明は、このような事情に鑑みなされたも
のであつて、振動基板上に形成する圧電薄膜の膜
厚を端に近づく程薄くなるようにするとともに、
圧電薄膜のＣ軸配向を端部に向かうほど中心方向
を向くように傾斜させることにより、不要なスプ
リアス成分を抑制し、振動特性を向上させること
ができる圧電振動子を提供することを目的とす
る。(c) Purpose of the Invention The present invention has been made in view of the above circumstances, and includes reducing the thickness of the piezoelectric thin film formed on the vibrating substrate as it approaches the edges, and
An object of the present invention is to provide a piezoelectric vibrator that can suppress unnecessary spurious components and improve vibration characteristics by tilting the C-axis orientation of a piezoelectric thin film so that it points toward the center toward the end. .
(d) 発明の構成および効果
この発明の圧電振動子は、２本以上の結合子で
支持された板状の恒弾性材料からなる振動基板
と、この振動基板上に形成された圧電薄膜と、さ
らにこの圧電薄膜上に形成された電極膜とで構成
される圧電振動子において、圧電薄膜を振動基板
上の略全面に形成するとともに、前記圧電薄膜の
膜厚を端部に近づく程薄くし、前記圧電薄膜のＣ
軸配向を中央部分で垂直とし、端部に近づく程中
心方向へ傾斜させた事を特徴とする。(d) Structure and Effects of the Invention The piezoelectric vibrator of the present invention includes a vibrating substrate made of a plate-shaped constant elastic material supported by two or more connectors, a piezoelectric thin film formed on the vibrating substrate, Furthermore, in a piezoelectric vibrator configured with an electrode film formed on this piezoelectric thin film, the piezoelectric thin film is formed on substantially the entire surface of the vibrating substrate, and the film thickness of the piezoelectric thin film is made thinner as it approaches the end portion, C of the piezoelectric thin film
It is characterized by an axial orientation that is vertical at the center and tilted toward the center as it approaches the ends.
この発明の圧電振動子を上記のように構成する
と、圧電薄膜の膜厚が端部に近づく程薄く、圧電
薄膜のＣ軸配向が端部で中心方向を向くように傾
斜しているので、圧電薄膜の周辺部での分極によ
る機械的応力（励振）は中央部に比べて相対的に
小さい。 When the piezoelectric vibrator of the present invention is constructed as described above, the film thickness of the piezoelectric thin film becomes thinner as it approaches the ends, and the C-axis orientation of the piezoelectric thin film is inclined so that it points toward the center at the ends. Mechanical stress (excitation) due to polarization at the periphery of the thin film is relatively smaller than at the center.
一般に、圧電振動子の屈曲振動や対称ラム波振
動は、その振動姿態から明らかなように、圧電振
動子の端部付近の励振によつてその振動効率が大
きく影響される。この発明の圧電振動子では、端
部付近での励振効率が低いため、屈曲振動や対称
ラム波振動が励起されにくくなり、このため基本
となる拡がり振動以外の屈曲振動や対称ラム波等
のスプリアス成分が効果的に抑制されて、拡がり
振動の利用効率が向上する。その結果、圧電振動
子の振動特性を向上させることができる。 Generally, the vibration efficiency of the bending vibration or symmetrical Lamb wave vibration of a piezoelectric vibrator is greatly affected by the excitation near the end of the piezoelectric vibrator, as is clear from the vibration mode. In the piezoelectric vibrator of this invention, since the excitation efficiency is low near the ends, bending vibrations and symmetrical Lamb wave vibrations are difficult to be excited. The components are effectively suppressed, and the efficiency of using the spreading vibration is improved. As a result, the vibration characteristics of the piezoelectric vibrator can be improved.
(e) 実施例
以下、振動基板１として方形のエリンバを用
い、圧電薄膜２として酸化亜鉛ZnOを用いた圧電
振動子にこの発明を実施した場合について説明す
る。(e) Example Hereinafter, a case will be described in which the present invention is applied to a piezoelectric vibrator using a rectangular Elinvar as the vibrating substrate 1 and using zinc oxide ZnO as the piezoelectric thin film 2.
第１図はこの発明の実施例で用いる圧電振動子
の第２図Ａ−Ａ線における横断面図、第２図は圧
電振動子の斜視図である。 FIG. 1 is a cross-sectional view taken along line A--A in FIG. 2 of a piezoelectric vibrator used in an embodiment of the present invention, and FIG. 2 is a perspective view of the piezoelectric vibrator.
この実施例の圧電振動子は、振動基板１と圧電
薄膜２と電極膜３とで構成されている。振動基板
１は、従来と同様の方形の薄板であり、エリンバ
の薄板に精密ケミカルエツチング加工を施すこと
により保持枠４および結合子５，５と一体形成さ
れている。圧電薄膜２は、Ｃ軸配向６が中央部分
で垂直となり、振動基板１上の両長辺に沿つた端
部に向かう程中心方向を向くように傾斜させて形
成されている。振動基板１上への圧電薄膜２の形
成は、スパツタリング等の気相成長法により行う
ので、膜形成の際に不要な部分を覆うためのマス
クを振動基板１の端辺に接するように配置し、且
つ、このマスクの厚さを充分に厚くすることによ
り、マスク端に近い部分での圧電薄膜２の成長を
抑制し、振動基板１上の端部において圧電薄膜の
膜厚を端に近づく程薄くなるように形成すること
ができ、この際に膜厚が薄くなつた部分のＣ軸配
向６が薄くなるほど余計に中心方向を向くように
傾斜させて形成することができる。電極膜３は、
従来と同様にこの圧電薄膜２上に端部を開けて形
成される。なお、圧電薄膜２および電極膜３は、
振動基板１上のみならず一方の結合子５を介して
保持枠４上の一部にまで引き出して形成され、こ
の引き出した電極膜３′部分から端子を取り出せ
るようにしている。また、この電極膜３に対応す
る圧電振動子の他方の電極は振動基板１が兼用し
ている。 The piezoelectric vibrator of this embodiment is composed of a vibrating substrate 1, a piezoelectric thin film 2, and an electrode film 3. The vibrating board 1 is a rectangular thin plate similar to the conventional one, and is integrally formed with the holding frame 4 and the connectors 5, 5 by applying precision chemical etching to a thin plate of Elinva. The piezoelectric thin film 2 is formed so that the C-axis orientation 6 is vertical at the center and tilted toward the center toward the ends along both long sides of the vibrating substrate 1. Since the piezoelectric thin film 2 is formed on the vibrating substrate 1 by a vapor phase growth method such as sputtering, a mask is placed in contact with the edge of the vibrating substrate 1 to cover unnecessary parts during film formation. In addition, by making the thickness of this mask sufficiently thick, the growth of the piezoelectric thin film 2 near the edge of the mask is suppressed, and the thickness of the piezoelectric thin film at the edge of the vibrating substrate 1 is increased as the thickness approaches the edge. It can be formed to become thinner, and at this time, it can be formed so that the C-axis orientation 6 of the portion where the film thickness becomes thinner is inclined more toward the center as the film thickness becomes thinner. The electrode film 3 is
As in the past, it is formed on this piezoelectric thin film 2 with open ends. Note that the piezoelectric thin film 2 and electrode film 3 are
It is formed not only on the vibrating substrate 1 but also on a part of the holding frame 4 through one of the connectors 5, so that the terminal can be taken out from this drawn-out electrode film 3' portion. Further, the vibration substrate 1 also serves as the other electrode of the piezoelectric vibrator corresponding to the electrode film 3.
実施例で圧電薄膜２のＣ軸配向６を傾斜させる
部分を振動基板１の両長辺に沿つた端部としたの
は、圧電振動子の拡がり振動の方向が結合子５，
５を結ぶ線に対して直角方向となるために、この
両長辺に沿つた端部でのＣ軸配向６の傾斜が振動
効率に最も大きな影響を与えるからである。した
がつて、結合子５，５を形成した振動基板１の短
辺側に沿つた端部においても、Ｃ軸配向６を傾斜
させてもよい。 In the embodiment, the portion where the C-axis orientation 6 of the piezoelectric thin film 2 is inclined is set at the ends along both long sides of the vibrating substrate 1 because the direction of the spreading vibration of the piezoelectric vibrator is
This is because the inclination of the C-axis orientation 6 at the ends along both long sides has the greatest influence on the vibration efficiency since the direction is perpendicular to the line connecting the two long sides. Therefore, the C-axis orientation 6 may also be inclined at the end along the short side of the vibrating substrate 1 on which the connectors 5, 5 are formed.
上記のように構成されたこの実施例の圧電振動
子は、圧電薄膜の膜厚を圧電薄膜の端部に近づく
程薄くなるようにするとともに、Ｃ軸配向６を端
部で中心方向を向くように傾斜させて形成するの
で、屈曲振動や対称ラム波等のスプリアス成分が
効果的に抑制され、拡がり振動の利用効率が向上
する。したがつて、この実施例の圧電振動子は、
不要なスプリアス成分が抑制され基本となる拡が
り振動が顕著となるので、振動特性の向上を図る
ことができる。 In the piezoelectric vibrator of this embodiment configured as described above, the thickness of the piezoelectric thin film is made thinner as it approaches the ends of the piezoelectric thin film, and the C-axis orientation 6 is made to point toward the center at the ends. Since it is formed so as to be inclined, spurious components such as bending vibrations and symmetrical Lamb waves are effectively suppressed, and the utilization efficiency of spreading vibrations is improved. Therefore, the piezoelectric vibrator of this example is
Since unnecessary spurious components are suppressed and the fundamental spread vibration becomes noticeable, vibration characteristics can be improved.
この振動特性の向上を、実施例で用いた圧電振
動子と従来の圧電振動子との周波数特性の測定結
果により示す。第４図は実施例で用いた圧電振動
子における周波数特性を示す図であり、第５図は
従来の圧電振動子の周波数特性を示す図である。
この第４図と第５図との比較から明らかなよう
に、従来の圧電振動子においてスプリアス成分と
して観測される屈曲振動や長さ振動および対称ラ
ム波が実施例で用いた圧電振動子の場合にはほと
んど見られず、基本となる拡がり振動における共
振周波数と反共振周波数でのインピーダンスの顕
著な変化のみが観測される。したがつて、この実
施例で用いた圧電振動子は従来の圧電振動子に比
べ振動特性が著しく向上している。 This improvement in vibration characteristics will be illustrated by measurement results of frequency characteristics of the piezoelectric vibrator used in the example and a conventional piezoelectric vibrator. FIG. 4 is a diagram showing the frequency characteristics of the piezoelectric vibrator used in the example, and FIG. 5 is a diagram showing the frequency characteristics of the conventional piezoelectric vibrator.
As is clear from the comparison between FIGS. 4 and 5, bending vibrations, length vibrations, and symmetric Lamb waves observed as spurious components in conventional piezoelectric vibrators are different from those observed in the piezoelectric vibrators used in the examples. , and only significant changes in impedance at the resonant and antiresonant frequencies of the fundamental spreading vibration are observed. Therefore, the piezoelectric vibrator used in this example has significantly improved vibration characteristics compared to conventional piezoelectric vibrators.
第１図はこの発明の実施例で用いる圧電振動子
の第２図Ａ−Ａ方向における横断面図、第２図は
圧電振動子の斜視図、第３図は従来の圧電振動子
の第２図Ａ−Ａ方向における横断面図、第４図は
実施例で用いた圧電振動子の周波数特性を示す
図、第５図は従来の圧電振動子の周波数特性を示
す図である。
１……振動基板、２……圧電薄膜、３……電極
膜、６……Ｃ軸配向。
1 is a cross-sectional view taken along the direction A-A in FIG. 2 of a piezoelectric vibrator used in an embodiment of the present invention, FIG. 2 is a perspective view of the piezoelectric vibrator, and FIG. 3 is a cross-sectional view of a conventional piezoelectric vibrator. 4 is a diagram showing the frequency characteristics of the piezoelectric vibrator used in the example, and FIG. 5 is a diagram showing the frequency characteristic of the conventional piezoelectric vibrator. 1... Vibration substrate, 2... Piezoelectric thin film, 3... Electrode film, 6... C-axis orientation.
Claims (1)
材料からなる振動基板と、この振動基板上に形成
された圧電薄膜と、さらにこの圧電薄膜上に形成
された電極膜とで構成される圧電振動子におい
て、圧電薄膜を振動基板上の略全面に形成すると
ともに、前記圧電薄膜の膜厚を端部に近づく程薄
くし、前記圧電薄膜のＣ軸配向を中央部分で垂直
とし、端部に近づく程中心方向へ傾斜させた事を
特徴とする圧電振動子。1 Consists of a vibrating substrate made of a plate-shaped constant elastic material supported by two or more connectors, a piezoelectric thin film formed on this vibrating substrate, and an electrode film further formed on this piezoelectric thin film. In a piezoelectric vibrator, a piezoelectric thin film is formed on substantially the entire surface of a vibrating substrate, and the film thickness of the piezoelectric thin film is made thinner as it approaches the ends, and the C-axis orientation of the piezoelectric thin film is vertical in the central part, and A piezoelectric vibrator characterized by being tilted toward the center as it approaches the center.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22936485A JPS6288412A (en) | 1985-10-14 | 1985-10-14 | Piezoelectric vibrator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22936485A JPS6288412A (en) | 1985-10-14 | 1985-10-14 | Piezoelectric vibrator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6288412A JPS6288412A (en) | 1987-04-22 |
| JPH0426247B2 true JPH0426247B2 (en) | 1992-05-06 |
Family
ID=16891007
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22936485A Granted JPS6288412A (en) | 1985-10-14 | 1985-10-14 | Piezoelectric vibrator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6288412A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002103900A1 (en) * | 2001-06-15 | 2002-12-27 | Ube Electronics, Ltd. | Thin-film piezoelectric resonator |
| JP2009094829A (en) * | 2007-10-10 | 2009-04-30 | Murata Mfg Co Ltd | Piezoelectric vibration device, oscillation circuit, and electronic apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6347070Y2 (en) * | 1981-03-06 | 1988-12-06 |
-
1985
- 1985-10-14 JP JP22936485A patent/JPS6288412A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002103900A1 (en) * | 2001-06-15 | 2002-12-27 | Ube Electronics, Ltd. | Thin-film piezoelectric resonator |
| JP2009094829A (en) * | 2007-10-10 | 2009-04-30 | Murata Mfg Co Ltd | Piezoelectric vibration device, oscillation circuit, and electronic apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6288412A (en) | 1987-04-22 |
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