JP2559708B2 - Piezoelectric vibrator - Google Patents

Piezoelectric vibrator

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Publication number
JP2559708B2
JP2559708B2 JP61160136A JP16013686A JP2559708B2 JP 2559708 B2 JP2559708 B2 JP 2559708B2 JP 61160136 A JP61160136 A JP 61160136A JP 16013686 A JP16013686 A JP 16013686A JP 2559708 B2 JP2559708 B2 JP 2559708B2
Authority
JP
Japan
Prior art keywords
electrodes
piezoelectric vibrator
groove
piezoelectric
vibrating medium
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
Application number
JP61160136A
Other languages
Japanese (ja)
Other versions
JPS6315599A (en
Inventor
茂 定村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Proterial Ltd
Original Assignee
Hitachi Metals Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Metals Ltd filed Critical Hitachi Metals Ltd
Priority to JP61160136A priority Critical patent/JP2559708B2/en
Publication of JPS6315599A publication Critical patent/JPS6315599A/en
Application granted granted Critical
Publication of JP2559708B2 publication Critical patent/JP2559708B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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  • Piezo-Electric Transducers For Audible Bands (AREA)
  • Transducers For Ultrasonic Waves (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は圧力センサー,歪検出用素子,超音波発振
子,歪発生素子等の圧電振動子の改良に関するものであ
る。
The present invention relates to improvements in piezoelectric vibrators such as pressure sensors, strain detecting elements, ultrasonic oscillators, and strain generating elements.

〔従来の技術〕[Conventional technology]

従来の歪検出用素子は,例えば第3図に示すような構
造である。すなわち,同図において1は振動媒体であ
り,例えばPb(Ti,Zr)O3等の圧電セラミックスにより
横断面矩形の角柱状に形成する。次に2,3は各々電極で
あり,導電性金属材料からなる薄膜(10μm程度)を前
記振動媒体の上下両面に設けると共に,下面の電極3は
振動媒体1の一方の端面に設けた電極3aを経由して延長
し,上面に設けた電極3bにおいて他方の電極2と間隔4
を置いて略同一平面内に対向するように配設する。そし
て上記電極2,3bに各々リード線5,6をはんだ付けして交
流電源と接続すれば,圧電作用によって振動媒体1が振
動する。一方逆に振動媒体1に外力が作用すれば,リー
ド線5,6の間に,上記外力の大きさに比例した電圧が発
生する。発生する出力電圧Vの大きさは,振動媒体1の
電気機械結合係数Kに比例し,静電容量Cの平方根に反
比例する。すなわち出力電圧Vは下記の式で表わされ
る。
A conventional strain detecting element has a structure as shown in FIG. 3, for example. That is, in the figure, reference numeral 1 is a vibrating medium, which is formed of a piezoelectric ceramic such as Pb (Ti, Zr) O 3 into a rectangular column shape having a rectangular cross section. Next, reference numerals 2 and 3 denote electrodes, and thin films (about 10 μm) made of a conductive metal material are provided on both upper and lower surfaces of the vibrating medium, and the lower electrode 3 is an electrode 3a provided on one end face of the vibrating medium 1. The electrode 3b provided on the upper surface and extended from the other electrode 2 by a distance 4
Are placed so as to face each other in substantially the same plane. When the lead wires 5 and 6 are soldered to the electrodes 2 and 3b and connected to an AC power source, the vibrating medium 1 vibrates by the piezoelectric action. On the contrary, when an external force acts on the vibration medium 1, a voltage proportional to the magnitude of the external force is generated between the lead wires 5 and 6. The magnitude of the generated output voltage V is proportional to the electromechanical coupling coefficient K of the vibration medium 1 and inversely proportional to the square root of the electrostatic capacitance C. That is, the output voltage V is represented by the following formula.

従って圧力センサーや歪検出用素子に使用される振動
媒体1には,できるだけ電気機械結合係数Kが大きく,
かつ静電容量Cの小さい材料が望ましい。
Therefore, the vibrating medium 1 used for the pressure sensor and the strain detecting element has the electromechanical coupling coefficient K as large as possible,
A material having a small capacitance C is desirable.

〔発明が解決しようとする問題点〕[Problems to be solved by the invention]

上記圧電振動子を製作する場合には,圧電セラミック
スからなる振動媒体1を分極処理して,圧電効率を向上
させるのが一般であり,この場合には2kV/mm以上の電圧
を印加する。圧電振動子は通常小型のものが多く,第3
図に示すものにおいては,例えば5mm角×10mm程度のも
のであり,電極2,3bの間隔4は1〜2mm程度である。従
って厚さ5mmの振動媒体1の分極処理に必要な例えば10k
Vの電圧を印加すると,間隔4の絶縁を確保できず,間
隔4が絶縁破壊するという問題点がある。このため,例
えば電極2および3,または電極2,3および3bを設けた状
態で分極処理を実施し,その後に電極3aおよび3bを設け
る方法を採用している。しかしながら電極として通常の
銀ペーストを550〜750℃で焼付ける手段を採るときに
は,振動媒体1を構成する圧電セラミックスのキューリ
ー点Tc=100〜450℃を越えることとなり,上記分極状態
が破壊されるため不都合である。従って電極3aおよび3b
を室温乾燥用ペーストで形成する手段を採用している
が,この作業は極めて煩雑であると共に,以後のリード
線6のはんだ付けにも支障が多く,強度等の品質を低下
させる等の問題点がある。
In the case of manufacturing the above-mentioned piezoelectric vibrator, it is general that the vibration medium 1 made of piezoelectric ceramics is polarized to improve the piezoelectric efficiency. In this case, a voltage of 2 kV / mm or more is applied. Piezoelectric vibrators are usually small in size.
In the case shown in the figure, for example, it is about 5 mm square × 10 mm, and the distance 4 between the electrodes 2 and 3b is about 1 to 2 mm. Therefore, for example, 10k required for the polarization treatment of the vibration medium 1 having a thickness of 5 mm
When the voltage of V is applied, there is a problem that the insulation of the space 4 cannot be secured and the space 4 is broken down. Therefore, for example, a method is adopted in which the polarization treatment is performed in a state where the electrodes 2 and 3 or the electrodes 2, 3 and 3b are provided, and then the electrodes 3a and 3b are provided. However, when a means for baking a normal silver paste at 550 to 750 ° C is adopted as an electrode, the Curie point Tc of the piezoelectric ceramics constituting the vibrating medium 1 exceeds 100 to 450 ° C, and the above polarized state is destroyed. It is inconvenient. Thus electrodes 3a and 3b
However, this work is extremely complicated, and there are many problems in the subsequent soldering of the lead wires 6 and the quality such as strength is deteriorated. There is.

本発明は上記従来の技術に存する問題点を解消し,製
作が容易であると共に品質および信頼性の高い圧電振動
子を提供することを目的とする。
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems existing in the conventional technique and to provide a piezoelectric vibrator which is easy to manufacture and has high quality and reliability.

〔問題点を解決するための手段〕[Means for solving problems]

上記問題点解決のために,本発明においては,導電性
金属材料からなる電極間に圧電セラミックスからなる信
号媒体を挟着すると共に,自由表面において前記両電極
が略同一平面内に間隔を置いて対向するように配設して
なる圧電振動子において,前記両電極の間に前記圧電セ
ラミックスの分極処理前に前記自由表面を含む溝を設け
ると共に、前記電極を分岐処理における電極と共用と
し、前記溝を介して前記振動媒体を異極性の電極に挟ま
れる変位部分と同極性の電極に挟まれる非変位部分とに
区分する,という技術的手段を採用したのである。
In order to solve the above-mentioned problems, in the present invention, a signal medium made of a piezoelectric ceramic is sandwiched between electrodes made of a conductive metal material, and the two electrodes are provided on a free surface with a space in substantially the same plane. In the piezoelectric vibrator arranged so as to face each other, a groove including the free surface is provided between the both electrodes before the polarization treatment of the piezoelectric ceramic, and the electrode is shared with the electrode in the branching treatment. The technical means of dividing the vibrating medium into a displacement portion sandwiched between electrodes of different polarities and a non-displacement portion sandwiched between electrodes of the same polarity via the groove was adopted.

〔作用〕[Action]

上記のように構成することにより,間隔4を介した電
極2,3間の沿面距離が大巾に増大するため,分極処理に
際し印加する電圧に対しても絶縁破壊することがなくな
る。従って分極処理前に所定の位置に電極2,3,3a,3bを
配設することができ,製作が極めて容易となる他,後述
の種々の効果を奏することができる。
With the above-described structure, the creepage distance between the electrodes 2 and 3 via the gap 4 is greatly increased, and therefore dielectric breakdown does not occur against the voltage applied during the polarization treatment. Therefore, the electrodes 2, 3, 3a, 3b can be arranged at predetermined positions before the polarization treatment, which makes the manufacturing extremely easy and can also achieve various effects described later.

〔実施例〕〔Example〕

第1図は本発明の実施例を示す要部側面図,第2図は
第1図におけるA−A線断面図であり,同一部分は前記
第3図と同一の参照符号で示す。両図において7は溝で
あり,電極2,3b間に設ける。溝7は振動媒体1の強度を
損なわない程度の深さに設けるが,第2図に示すように
振動媒体1の側面部1a,1bに開放するように形成する。
なお電極2,3bには第3図と同様のリード線(図示せず)
をはんだ付けする。
1 is a side view of an essential part showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and the same portions are designated by the same reference numerals as those in FIG. In both figures, 7 is a groove, which is provided between the electrodes 2 and 3b. Although the groove 7 is provided at a depth that does not impair the strength of the vibration medium 1, it is formed so as to be open to the side surface portions 1a and 1b of the vibration medium 1 as shown in FIG.
In addition, lead wires (not shown) similar to those in FIG. 3 are used for the electrodes 2 and 3b.
To solder.

この場合、振動媒体1は分極処理前であるため、電極
2,3,3a,3bは、通常の銀ペーストを550〜750℃で焼付け
る手段により形成することができる。このようにして電
極2と電極3,3a,3bとの間に分極処理に必要な例えば10k
Vの電圧を印加すれば、振動媒体1の電極2と電極3と
によって挟まれる部分のみが分極処理されて変位部分11
となり、その他の部分は分極処理されず、非変位部分12
となるのである。
In this case, since the vibrating medium 1 has not been polarized,
2,3,3a and 3b can be formed by means of baking a normal silver paste at 550 to 750 ° C. In this way, between the electrode 2 and the electrodes 3, 3a, 3b, for example, 10k required for polarization treatment
When a voltage of V is applied, only the portion of the vibrating medium 1 sandwiched by the electrode 2 and the electrode 3 is polarized and the displaced portion 11
, The other parts are not polarized and the non-displacement part 12
It becomes.

以上の構成によりリード線を介して電極2,3間に電圧
を印加し,または振動媒体1に力(歪)を加えれば,圧
電振動氏としての機能を発揮することは,前記第3図に
示すものと同一である。上記の通常の機能に加えて,第
1図および第2図に示すものにおいては,溝7を介して
変位部分11と非変位部分12とに区分されているため,変
位部分11の振動が容易である。従って同一の電圧の印加
によっても大なる変位若しくは振動を生起することがで
きると共に,受信素子として使用した場合には同一変位
によっても大なる電圧を生起することができる。すなわ
ち電気機械結合係数Kを例えば従来の0.52から0.67に大
きくすることができるのである。また上記溝7を設けた
ことにより,振動媒体1からの漏れ容量(静電)が極め
て小さくなるため,振動媒体1の静電容量Cを例えば従
来の34pFから27pFに低減させることができるため,誘起
電圧を大きくするという副次的効果も併有する。
With the above configuration, if a voltage (voltage) is applied between the electrodes 2 and 3 via the lead wire or a force (distortion) is applied to the vibrating medium 1, the function as a piezoelectric vibrating element can be exerted. It is the same as shown. In addition to the normal function described above, in the one shown in FIGS. 1 and 2, the displacement portion 11 and the non-displacement portion 12 are divided by the groove 7, so that the displacement portion 11 can easily vibrate. Is. Therefore, even if the same voltage is applied, a large displacement or vibration can be generated, and when used as a receiving element, a large voltage can be generated by the same displacement. That is, the electromechanical coupling coefficient K can be increased from the conventional 0.52 to 0.67. Further, since the leakage capacitance (electrostatic capacity) from the vibration medium 1 is extremely reduced by providing the groove 7, the capacitance C of the vibration medium 1 can be reduced from the conventional 34 pF to 27 pF, for example. It also has a secondary effect of increasing the induced voltage.

本実施例においては横断面正方形の角柱状のものにつ
いて記述したが,横断面が矩形状のものでも当然に作用
は同一である。また平板状若しくは円板状のものにおい
て,略同一平面内に電極を配設したものについても,例
えば外周部に設けた非変位部分と中央部に設けた変位部
分との境界部に額縁状若しくはリング状の溝を形成して
もよいことは当然である。また上記圧電振動子は受信用
および発信用の両者に適用できると共に,圧力センサー
としても適用できる。
In the present embodiment, a prism having a square cross section is described, but the same effect can be obtained if the cross section is rectangular. Also, in the case of a flat plate-shaped or disc-shaped one in which electrodes are arranged in substantially the same plane, for example, a frame-shaped or It goes without saying that a ring-shaped groove may be formed. Further, the piezoelectric vibrator can be applied to both reception and transmission, and can also be applied as a pressure sensor.

〔発明の効果〕〔The invention's effect〕

本発明は以上記述のような構成および作用であるか
ら,下記の効果を奏することができる。
Since the present invention has the configuration and operation as described above, the following effects can be obtained.

(1) 電極間の沿面距離が増大するため,電極を配設
した後に分極処理をすることができ,製作が容易である
と共に,工程が大巾に短縮され,生産効率が向上する。
(1) Since the creepage distance between the electrodes is increased, it is possible to perform the polarization treatment after disposing the electrodes, which facilitates the production and greatly shortens the process, thus improving the production efficiency.

(2) 電極の配設には圧電セラミックスのキューリー
点を勘案する必要がないため,例えば銀ペーストによる
焼付けが可能であり,圧電振動子の強度を初めとする品
質および信頼性を大巾に向上させることができる。
(2) Since it is not necessary to consider the Curie point of the piezoelectric ceramics when arranging the electrodes, it is possible to bake with, for example, silver paste, and the quality and reliability including the strength of the piezoelectric vibrator are greatly improved. Can be made.

(3) 変位部分が非変位部分によって拘束されること
がないため,電気機械結合係数を増大させることができ
圧電定数を増大させ得る。
(3) Since the displaced portion is not constrained by the non-displaced portion, the electromechanical coupling coefficient can be increased and the piezoelectric constant can be increased.

(4) 静電容量が減少するため,結果として電圧出力
係数を増大させることができ,(3)と共に高効率かつ
高感度の圧電振動子とすることができる。
(4) Since the capacitance is reduced, the voltage output coefficient can be increased as a result, and the piezoelectric vibrator with high efficiency and high sensitivity can be obtained together with (3).

【図面の簡単な説明】[Brief description of drawings]

第1図は本発明の実施例を示す要部側面図,第2図は第
1図におけるA−A線断面図,第3図は従来のものを示
す要部側面図である。 1:振動媒体,7:溝,11:変位部分,12:非変位部分。
FIG. 1 is a side view of an essential part showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 1: Vibrating medium, 7: Groove, 11: Displacement part, 12: Non-displacement part.

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】導電性金属材料からなる電極間に圧電セラ
ミックスからなる振動媒体を挟着すると共に、自由表面
において前記両電極が略同一平面内に間隔を置いて対向
するように配設してなる圧電振動子において、前記両電
極の間に前記圧電セラミックスの分極処理前に前記自由
表面を含む溝を設けると共に、前記電極を分極処理にお
ける電極と共用とし、前記溝を介して前記振動媒体を異
極性の電極に挟まれる変位部分と同極性の電極に挟まれ
る非変位部分とに区分したことを特徴とする圧電振動
子。
1. A vibrating medium made of piezoelectric ceramics is sandwiched between electrodes made of a conductive metal material, and the two electrodes are arranged so as to face each other on a free surface in a substantially same plane with a space therebetween. In the piezoelectric vibrator, the groove including the free surface is provided between the both electrodes before the polarization processing of the piezoelectric ceramic, the electrode is also used as the electrode in the polarization processing, and the vibrating medium is provided through the groove. A piezoelectric vibrator characterized by being divided into a displacement portion sandwiched between electrodes of different polarities and a non-displacement portion sandwiched between electrodes of the same polarity.
【請求項2】振動媒体の横断面が矩形であり、溝を前記
振動媒体の長手方向に対して略直交するように設けた特
許請求の範囲第1項記載の圧電振動子。
2. The piezoelectric vibrator according to claim 1, wherein the vibrating medium has a rectangular cross section, and the groove is provided so as to be substantially orthogonal to the longitudinal direction of the vibrating medium.
【請求項3】振動媒体が平板状であり、溝を額縁状若し
くはリング状に形成した特許請求の範囲第1項記載の圧
電振動子。
3. The piezoelectric vibrator according to claim 1, wherein the vibrating medium has a flat plate shape, and the groove is formed in a frame shape or a ring shape.
JP61160136A 1986-07-08 1986-07-08 Piezoelectric vibrator Expired - Lifetime JP2559708B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP61160136A JP2559708B2 (en) 1986-07-08 1986-07-08 Piezoelectric vibrator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP61160136A JP2559708B2 (en) 1986-07-08 1986-07-08 Piezoelectric vibrator

Publications (2)

Publication Number Publication Date
JPS6315599A JPS6315599A (en) 1988-01-22
JP2559708B2 true JP2559708B2 (en) 1996-12-04

Family

ID=15708650

Family Applications (1)

Application Number Title Priority Date Filing Date
JP61160136A Expired - Lifetime JP2559708B2 (en) 1986-07-08 1986-07-08 Piezoelectric vibrator

Country Status (1)

Country Link
JP (1) JP2559708B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6196400B2 (en) * 2015-01-29 2017-09-13 富士フイルム株式会社 Electroacoustic conversion film

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS607822Y2 (en) * 1977-06-28 1985-03-16 松下電器産業株式会社 Piezoelectric vibrator for ultrasonic atomizer
US4460841A (en) * 1982-02-16 1984-07-17 General Electric Company Ultrasonic transducer shading
JPS6079898U (en) * 1983-11-08 1985-06-03 株式会社トキメック ultrasonic transducer

Also Published As

Publication number Publication date
JPS6315599A (en) 1988-01-22

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