JPH05160464A - Method of polarizing piezoelectric substance - Google Patents
Method of polarizing piezoelectric substanceInfo
- Publication number
- JPH05160464A JPH05160464A JP32311391A JP32311391A JPH05160464A JP H05160464 A JPH05160464 A JP H05160464A JP 32311391 A JP32311391 A JP 32311391A JP 32311391 A JP32311391 A JP 32311391A JP H05160464 A JPH05160464 A JP H05160464A
- Authority
- JP
- Japan
- Prior art keywords
- polarization
- piezoelectric
- degree
- electric field
- piezoelectric body
- 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.)
- Granted
Links
Landscapes
- 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、例えば圧電フィルター
や圧電共振子等の圧電部品に用いられる圧電体の分極方
法に関し、特に、圧電体の分極から部品としての完成品
を得るに至る間に電気的特性の劣化が生じ難い、圧電体
の分極方法を提供するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for polarizing a piezoelectric body used in a piezoelectric component such as a piezoelectric filter or a piezoelectric resonator, and in particular, from the polarization of the piezoelectric body until a finished product as a component is obtained. It is intended to provide a method of polarizing a piezoelectric body in which deterioration of electrical characteristics is less likely to occur.
【０００２】[0002]
【従来の技術】圧電フィルターや圧電共振子を得るのに
用いられる圧電体の分極処理に際しては、一般に、抗電
界の３倍程度の直流電界を圧電体に印加し、それによっ
て圧電体を飽和分極させることにより行われている。し
かしながら、分極処理された圧電体を用いて圧電部品を
製品として完成させるまでには、個々の圧電部品単位へ
の圧電体の切断（素子カット）、端子取り付けあるいは
樹脂外装形式等の物理的外力や熱ストレスの加わる種々
の工程が実施されるのが普通である。2. Description of the Related Art In the polarization treatment of a piezoelectric body used to obtain a piezoelectric filter or a piezoelectric resonator, generally, a DC electric field which is about three times the coercive electric field is applied to the piezoelectric body, whereby the piezoelectric body is saturated and polarized. It is done by letting. However, until the piezoelectric component is completed as a product by using the polarized piezoelectric substance, cutting of the piezoelectric substance into individual piezoelectric component units (element cutting), attachment of terminals, or physical external force such as resin coating type It is common to perform various processes that are subject to heat stress.
【０００３】[0003]
【発明が解決しようとする課題】上記のように、圧電フ
ィルターや圧電共振子等の圧電部品を得るにあたって
は、分極処理後に種々の工程において圧電体に物理的な
力や熱ストレスが加わっていた。そのため、図２に実線
Ａで示す様に圧電体を所望の分極度に分極していたとし
ても、上記のような各工程を得た後では、個々の圧電部
品中の圧電体の分極度が破線Ｂで示すように低下すると
いう問題があった。また、図３に各工程直後の分極度及
びそのばらつきを示すように、分極度が単に低下するだ
けでなく、工程を得るごとに分極度のばらつきも大きく
なるという問題があった。その結果、圧電体を所望の分
極度に分極処理したとしても、設計通りの電気的な特性
を示す圧電部品を得ることが非常に困難であった。な
お、上記のような分極度の低下は、抗電界が１５ｋＶ／
ｃｍ以下のソフトな圧電材料からなる圧電体において、
厚み縦振動を利用した比較的厚さの薄い製品において、
特に顕著にあらわれていた。As described above, when a piezoelectric component such as a piezoelectric filter or a piezoelectric resonator is obtained, physical force or thermal stress is applied to the piezoelectric body in various steps after the polarization treatment. .. Therefore, even if the piezoelectric body is polarized to a desired degree of polarization as shown by the solid line A in FIG. 2, the polarization degree of the piezoelectric body in each piezoelectric component will not change after the above-described steps. There is a problem that it decreases as shown by the broken line B. Further, as shown in FIG. 3 showing the degree of polarization and the variation thereof immediately after each step, there is a problem that the degree of polarization not only decreases but also the variation of the degree of polarization increases with each step. As a result, even if the piezoelectric body is polarized to a desired degree of polarization, it is very difficult to obtain a piezoelectric component that exhibits electrical characteristics as designed. The decrease in the polarization degree as described above means that the coercive electric field is 15 kV /
In a piezoelectric body made of a soft piezoelectric material of cm or less,
In products with relatively thin thickness using thickness longitudinal vibration,
It was particularly noticeable.
【０００４】本発明の目的は、圧電体を所望の分極度に
分極し得るだけでなく、該圧電体を用いた製品における
分極度の低下、ひいては圧電部品の電気的な特性の劣化
が生じ難い圧電体の分極方法を提供することにある。The object of the present invention is not only to polarize a piezoelectric body to a desired degree of polarization, but also to reduce the degree of polarization of products using the piezoelectric body, and thus to prevent deterioration of the electrical characteristics of piezoelectric components. It is to provide a method of polarizing a piezoelectric body.
【０００５】[0005]
【課題を解決するための手段】本発明は、圧電体を一定
の方向に分極処理し、第１の分極度を有するように分極
処理する工程と、前記分極処理に続いて、逆方向にバイ
アス電界を印加することにより圧電体の分極度を第１の
分極度の１／１０以下とする工程と、分極度の低下され
た圧電体の両主面に電極を形成する工程と、前記圧電体
を用いて圧電部品を構成する工程と、前記圧電部品を構
成する工程を終えた後に、前記電極から、前記圧電体に
対して第１の分極度を得た場合の分極処理と同一方向に
抗電界を超える電界を印加し部分分極により所望の分極
度を得る工程とを備える、圧電体の分極方法である。According to the present invention, a step of polarizing a piezoelectric body in a certain direction to obtain a first degree of polarization, and a bias in a reverse direction following the polarization treatment are provided. Applying an electric field to reduce the degree of polarization of the piezoelectric body to 1/10 or less of the first degree of polarization; forming electrodes on both principal surfaces of the piezoelectric body having a reduced degree of polarization; After forming the step of forming a piezoelectric component using the piezoelectric element and the step of forming the piezoelectric component, the electrode is subjected to the same direction of polarization treatment as when the first polarization degree is obtained from the electrode with respect to the piezoelectric body. And a step of applying an electric field exceeding the electric field to obtain a desired degree of polarization by partial polarization.
【０００６】[0006]
【作用】本発明では、圧電体を第１の分極度を有するよ
うに一定の方向に分極処理した後に、逆方向にバイアス
電界を印加することにより、圧電体の分極度を第１の分
極度の１／１０以下とする。すなわち、このバイアス電
界の印加により、図２に実線Ｃで示すように、圧電体の
分極度が非常に小さくされる。そして、分極度が低下さ
れた圧電体の両主面に電極を形成し、該圧電体を用いて
圧電部品を構成するため、電極の形成や圧電部品を構成
する種々の工程において、物理的な応力や熱ストレスが
圧電体に加わったとしても、該圧電体の分極が小さいた
め、上記物理的な応力や熱ストレスの影響を小さくする
ことが可能とされる。In the present invention, the polarization degree of the piezoelectric body is changed to the first polarization degree by applying the bias electric field in the reverse direction after the piezoelectric body is polarized in a certain direction so as to have the first polarization degree. 1/10 or less. That is, by applying this bias electric field, as shown by the solid line C in FIG. 2, the polarization degree of the piezoelectric body is made extremely small. Then, electrodes are formed on both main surfaces of the piezoelectric body having a reduced degree of polarization, and the piezoelectric component is used to form the piezoelectric component. Therefore, in various steps of forming the electrode and forming the piezoelectric component, physical Even if stress or heat stress is applied to the piezoelectric body, since the polarization of the piezoelectric body is small, it is possible to reduce the influence of the physical stress or heat stress.
【０００７】そして、本発明では、圧電部品を構成する
各工程を得た後に、再度第１の分極度を得た場合の分極
処理と同一方向に抗電界を超える電界を印加して、部分
分極し、それによって圧電部品中の圧電体の所望部分を
所望の分極度とする。すなわち、本発明は、製品として
の圧電部品を得た後に、該圧電部品中の圧電体の所望部
分を部分分極処理することにより、圧電部品を得る各工
程において加えられた応力や熱ストレスの影響に関わら
ず、所望の分極度を実現することに特徴を有する。In the present invention, after each step of forming the piezoelectric component is obtained, an electric field exceeding the coercive electric field is applied in the same direction as the polarization treatment when the first polarization degree is obtained again, and the partial polarization is performed. As a result, the desired portion of the piezoelectric body in the piezoelectric component has the desired polarization degree. That is, according to the present invention, after the piezoelectric component as a product is obtained, the desired portion of the piezoelectric body in the piezoelectric component is partially polarized, so that the influence of the stress or the thermal stress applied in each step of obtaining the piezoelectric component is affected. Regardless of this, the feature is that a desired degree of polarization is realized.
【０００８】なお、製品としての圧電部品を得る前に、
第１の分極処理及び上記バイアス電界を印加する各工程
を実施するのは、このような工程を得ることにより、最
終的な部分分極に際し、最初の分極処理履歴のために抗
電界以上の小さな電界で、しかも短時間で分極を回復さ
せることができるからである。すなわち、例えソフトな
圧電材料からなる圧電体であっても、上記のような第１
の分極度を得る分極処理並びにバイアス電界を印加する
処理を得た後に、再度分極処理を行うことが不可欠であ
り、上記のような当初の分極処理を行わなければ、抗電
界を超える比較的小さな電界で圧電体を部分分極するこ
とはできない。Before obtaining the piezoelectric component as a product,
Performing the first polarization treatment and each step of applying the bias electric field is performed by obtaining such a step, and at the time of final partial polarization, a small electric field higher than the coercive electric field due to the first polarization treatment history. This is because the polarization can be recovered in a short time. That is, even if the piezoelectric body is made of a soft piezoelectric material,
It is indispensable to perform the polarization process again after obtaining the polarization process for obtaining the polarization degree and the process for applying the bias electric field. If the initial polarization process as described above is not performed, the coercive electric field exceeding the coercive electric field is relatively small. The piezoelectric field cannot be partially polarized by the electric field.
【０００９】[0009]
【発明の効果】従って、本発明によれば、圧電体を第１
の分極度を有するように分極処理し、逆方向にバイアス
電界を印加して第１の分極度の１／１０以下の分極度と
して、圧電部品を構成する各工程を実施するため、圧電
部品を構成する際に、加えられる応力や熱ストレスの分
極状態に与える影響を低減することができる。しかも、
圧電部品を構成した後に再度分極処理を行うものである
ため、抗電界を超える比較的小さな電界を印加すること
により圧電体の所望の部分を高精度に部分分極すること
が可能となる。Therefore, according to the present invention, the piezoelectric member is
Of the piezoelectric component to perform the respective steps of forming the piezoelectric component with a polarization degree of 1/10 or less of the first polarization degree by applying a bias electric field in the reverse direction. At the time of construction, it is possible to reduce the influence of applied stress and thermal stress on the polarization state. Moreover,
Since the polarization process is performed again after the piezoelectric component is configured, it is possible to highly accurately partially polarize a desired portion of the piezoelectric body by applying a relatively small electric field exceeding the coercive electric field.
【００１０】よって、本発明の圧電体の分極方法を利用
することにより、所望通りの電気的特性を有し、かつ特
性のばらつきの少ない圧電部品を安定に供給することが
可能となる。また、圧電部品を製造するにあたり、圧電
体の切断や電極の形成等の途中の工程における電気的な
特性の劣化が生じ難いため、圧電部品の歩留りも高めら
れる。Therefore, by utilizing the method of polarizing the piezoelectric body of the present invention, it becomes possible to stably supply a piezoelectric component having desired electrical characteristics and less variation in characteristics. Further, in manufacturing the piezoelectric component, the deterioration of the electrical characteristics is less likely to occur during the process of cutting the piezoelectric body, forming the electrodes, etc., so that the yield of the piezoelectric component can be increased.
【００１１】[0011]
【実施例の説明】図４〜図６を参照して、本発明の圧電
体の分極方法の原理を説明する。圧電体として、チタン
酸ジルコン酸鉛系圧電セラミックスを例にとると、チタ
ン酸ジルコン酸鉛系圧電セラミックスは、正方晶と三方
晶に属し、分極容易軸は、それぞれ、σ及びδの１４通
りの方向をとることができる。分極処理前の圧電体の分
極状態を図４（ａ）に示す。圧電体１は、分極処理前に
は、矢印方向で分極方向を示すように、内部の分極状態
がランダムな状態となっている。次に、圧電体１の両主
面に形成された分極用の電極２，３から厚み方向に直流
電界を印加すると、図４（ｂ）に示すように、圧電体１
が厚み方向に分極処理される。もっとも、分極軸は図６
のａの状態からｄで示す状態となるように、電界方向を
中心とするある任意の角度の円錐の中に全ての分極Ｐが
分布するようになる。なお、図４（ｂ）では、分極を示
す矢印が圧電体１の厚み方向に一様な方向を向くように
図示されているが、これはあくまでも分極の平均値を表
しているものであり、実際には、図６にｄで示す状態の
ように、飽和分極状態となっても、分極軸が完全に一軸
方向に揃うことはありえない。DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of the piezoelectric polarization method of the present invention will be described with reference to FIGS. Taking the lead zirconate titanate-based piezoelectric ceramics as an example of the piezoelectric body, the lead zirconate titanate-based piezoelectric ceramics belong to the tetragonal system and the trigonal system, and the easy polarization axes are 14 kinds of σ and δ, respectively. Can take direction. The polarization state of the piezoelectric body before polarization processing is shown in FIG. Prior to the polarization process, the piezoelectric body 1 has a random internal polarization state as indicated by the arrow direction. Next, when a DC electric field is applied in the thickness direction from the polarization electrodes 2 and 3 formed on both main surfaces of the piezoelectric body 1, as shown in FIG.
Is polarized in the thickness direction. However, the polarization axis is shown in Fig. 6.
From the state of a to the state of d, all the polarizations P are distributed in the cone having an arbitrary angle centered on the electric field direction. In addition, in FIG. 4B, the arrow indicating the polarization is illustrated so as to point in a uniform direction in the thickness direction of the piezoelectric body 1, but this only represents the average value of the polarization, In reality, as in the state shown by d in FIG. 6, the polarization axes cannot be completely aligned in the uniaxial direction even in the saturated polarization state.
【００１２】次に、上記分極処理と逆方向にバイアス電
界を印加すると、図６のｅに示す状態からｆに示す状態
となり、徐々に分極Ｐが低下していく。この分極Ｐの分
布状態は、図４（ｃ）に示すように上向きの矢印及び下
向きの矢印で示すように、正方向及び負方向の分極Ｐが
局在化し、バランスするようになる。従って、再度最初
の分極方向と同一方向（正方向）に直流電界を印加する
と、低い電界により、初期の高い分極状態へ回復する
（図６の破線ｇ参照）。なお、図６のｆで示す状態は、
見かけ上分極Ｐ＝０であるが、分極軸は分極前のランダ
ムな状態（図６のａで示す状態及び図４（ａ）に示した
状態）とは全く異なり、任意の分極容易軸に局在して分
布している。従って、上記のように、図６の破線ｇで示
すように、比較的は低い電界により、高い分極状態を実
現することができる。Next, when a bias electric field is applied in the reverse direction of the above polarization treatment, the state shown in e of FIG. 6 changes to the state shown in f, and the polarization P gradually decreases. In the distribution state of the polarization P, the polarization P in the positive direction and the polarization in the negative direction are localized and balanced as shown by the upward arrow and the downward arrow as shown in FIG. Therefore, when a DC electric field is applied again in the same direction (positive direction) as the first polarization direction, the low electric field restores the initial high polarization state (see the broken line g in FIG. 6). The state shown by f in FIG.
Although the polarization P is apparently 0, the polarization axis is completely different from the random state before polarization (the state shown in a of FIG. 6 and the state shown in FIG. 4A), and the polarization axis is local to any easy axis of polarization. It exists and is distributed. Therefore, as described above, as shown by the broken line g in FIG. 6, a high polarization state can be realized by a relatively low electric field.
【００１３】本発明では、上記のように再度正方向に分
極する前に、圧電部品が構成される。すなわち、図４
（ｃ）に示した圧電体１の分極用電極２，３を除去し、
個々の圧電部品を製作する。例えば、エネルギー閉込め
型の圧電共振部品を得る場合を例にとり、図５を参照し
て説明する。所定の大きさに切断された圧電体１の両主
面に部分的に電極４，５を形成し、さらに樹脂外装６を
形成し、しかる後、電極４，５から上記のような比較的
低い電界を印加することにより、圧電共振部品７内の圧
電体１が所望の分極度となるように分極される。In the present invention, the piezoelectric component is constructed before it is polarized in the positive direction again as described above. That is, FIG.
The polarization electrodes 2 and 3 of the piezoelectric body 1 shown in (c) are removed,
Produce individual piezoelectric components. For example, the case of obtaining a piezoelectric resonance component of energy confinement type will be described with reference to FIG. Electrodes 4 and 5 are partially formed on both main surfaces of the piezoelectric body 1 cut into a predetermined size, and a resin sheath 6 is further formed. Thereafter, the electrodes 4 and 5 are relatively low as described above. By applying an electric field, the piezoelectric body 1 in the piezoelectric resonance component 7 is polarized so as to have a desired polarization degree.
【００１４】本発明の分極方法を用いれば、例えば、図
５に示した圧電共振部品７における共振周波数ｆ0 を分
極度により高精度に制御することができる。すなわち、
飽和分極状態の圧電体１を用いて構成された圧電共振部
品７のインピーダンス−周波数特性が図７の実線Ｃで示
す曲線のようになり、上記飽和分極後に逆方向にバイア
ス電界を印加した後のインピーダンス−周波数特性が図
７の一定鎖線Ｄに示す曲線である場合を想定する。この
場合、一定鎖線Ｄで示す曲線から明らかなように、バイ
アス電界を逆方向に印加することにより、分極度が飽和
分極状態の１／１０以下とされるためバイアス電界を印
加した後においては、共振点ｆｒ´と***振点ｆａ´と
がほぼ一致するため、バイアス電界印加後の圧電共振部
品の共振周波数ｆ0 ´は、圧電体１を構成する材料及び
形状固有の値である。By using the polarization method of the present invention, for example, the resonance frequency f 0 in the piezoelectric resonance component 7 shown in FIG. 5 can be controlled with high accuracy by the polarization degree. That is,
The impedance-frequency characteristic of the piezoelectric resonance component 7 formed by using the piezoelectric body 1 in the saturated polarization state becomes like the curve shown by the solid line C in FIG. 7, and after applying the bias electric field in the opposite direction after the saturation polarization. It is assumed that the impedance-frequency characteristic is the curve shown by the constant chain line D in FIG. 7. In this case, as is clear from the curve indicated by the constant chain line D, by applying the bias electric field in the opposite direction, the polarization degree becomes 1/10 or less of the saturated polarization state, so that after applying the bias electric field, Since the resonance point fr ′ and the anti-resonance point fa ′ substantially coincide with each other, the resonance frequency f 0 ′ of the piezoelectric resonance component after applying the bias electric field is a value specific to the material and shape of the piezoelectric body 1.
【００１５】よって、当初の分極方向と同一方向に抗電
界よりも大きな電界を印加して所望の分極度とした場
合、そのインピーダンス−周波数特性は、図８に一定鎖
線Ｅで示す通りとなる。この場合、一定鎖線Ｅで示され
るインピーダンス−周波数特性で表される共振特性の共
振点ｆ0 は、バイアス電界を印加して分極度が極度に低
下された状態の共振周波数ｆ0 ´からのシフト量、すな
わち再分極することにより得られる分極度により制御し
得ることがわかる。言い換えれば、図９に示すように、
再分極により得られる圧電共振部品７の共振周波数は、
該圧電共振部品７の共振点と***振点との間の周波数差
Δｆ＝ｆr −ｆa （Δｆは、分極Ｐと比例関係にある）
により制御され得るため、上記再分極に際して得られる
分極度により圧電共振部品７の共振周波数を高精度に制
御することができる。なお、図９においてｆ0 ″は、飽
和分極状態の場合（すなわち図７，８の実線Ｃの共振特
性の場合）の共振周波数を示す。Therefore, when an electric field larger than the coercive electric field is applied in the same direction as the original polarization direction to obtain a desired degree of polarization, the impedance-frequency characteristic becomes as shown by the constant chain line E in FIG. In this case, the resonance point f 0 of the resonance characteristic represented by the impedance-frequency characteristic indicated by the constant chain line E is shifted from the resonance frequency f 0 ′ in the state where the polarization degree is extremely lowered by applying the bias electric field. It can be seen that it can be controlled by the amount, that is, the degree of polarization obtained by repolarization. In other words, as shown in FIG.
The resonance frequency of the piezoelectric resonance component 7 obtained by repolarization is
Frequency difference Δf = f r -f a between the resonance point and the antiresonance point of the piezoelectric resonance component 7 (Delta] f is proportional to the polarization P)
Therefore, the resonance frequency of the piezoelectric resonance component 7 can be controlled with high accuracy by the polarization degree obtained during the repolarization. In FIG. 9, f 0 ″ represents the resonance frequency in the saturated polarization state (that is, in the resonance characteristic of the solid line C in FIGS. 7 and 8).
【００１６】次に、具体的な実験例につき説明する。圧
電体として、Ｐｂ（Ｔｉ，Ｚｒ）Ｏ3 系の正方晶と三方
晶との相境界に位置し、ソフトな圧電材料に属するもの
を用いた。なお、この圧電体の抗電界は１２ｋＶ／ｃｍ
（室温）である。上記圧電体を用い、厚み縦振動モード
を利用した共振周波数１２ＭＨｚの圧電共振子を作製し
た。まず、圧電体として、厚み１８０μｍにラップされ
たものを用意し、両面にＡｇ膜及びＣｕ膜からなる多層
の分極用の電極膜を形成した。次に、６０℃の絶縁オイ
ル中において、上記圧電体に、５４０Ｖ／１８０μｍ
（３０ｋＶ／ｃｍ）及び３０分の条件で分極処理を行
い、さらに１５０℃、１時間の熱エージングを行って特
性の安定化を図った。なお、この分極条件により処理さ
れた圧電体は十分な飽和分極状態とされた（図１のａで
示す状態）。Next, a concrete experimental example will be described. As the piezoelectric body, one that is located at the phase boundary between the Pb (Ti, Zr) O 3 system tetragonal system and the trigonal system and belongs to a soft piezoelectric material was used. The coercive electric field of this piezoelectric body is 12 kV / cm.
(Room temperature). A piezoelectric resonator having a resonance frequency of 12 MHz using the thickness extensional vibration mode was produced using the above piezoelectric body. First, as a piezoelectric body, one wrapped to a thickness of 180 μm was prepared, and a multi-layered electrode film for polarization composed of an Ag film and a Cu film was formed on both surfaces. Next, in the insulating oil at 60 ° C., the piezoelectric body was subjected to 540 V / 180 μm.
Polarization treatment was performed under conditions of (30 kV / cm) and 30 minutes, and further thermal aging at 150 ° C. for 1 hour was performed to stabilize the characteristics. The piezoelectric body treated under these polarization conditions was in a sufficiently saturated polarization state (state shown by a in FIG. 1).
【００１７】次に、最初の分極方向とは逆方向に、３０
０Ｖ／１８０μｍで６０秒間、室温でバイアス電界を印
加した。その結果、分極度Δｆ＝ｆr −ｆａでは５０ｋ
ＨＺ以下と十分に小さくなった（図１のｂで示す状
態）。次に、上記圧電体の両主面をエッチングすること
により、図１０（ａ）に示す電極１１，１２が両主面に
整列形成された圧電板を得、個々の圧電共振部品単位に
該圧電板を切断し、図１０に示されている圧電板１３を
得た。しかる後、圧電板１３の両主面に形成されている
電極１１，１２に端子を接合し、該端子が引き出されて
いる部分を除いて樹脂外装１４を形成し、圧電共振部品
１５を得た。Next, in the direction opposite to the first polarization direction, 30
A bias electric field was applied at room temperature for 60 seconds at 0 V / 180 μm. As a result, the polarization degree Delta] f = the f r -fa 50k
It became sufficiently small as HZ or less (state shown by b in FIG. 1). Next, by etching both main surfaces of the piezoelectric body, a piezoelectric plate in which electrodes 11 and 12 shown in FIG. 10 (a) are formed in alignment on both main surfaces is obtained, and the piezoelectric plate is formed in each piezoelectric resonance component unit. The plate was cut to obtain the piezoelectric plate 13 shown in FIG. After that, terminals are joined to the electrodes 11 and 12 formed on both main surfaces of the piezoelectric plate 13, and the resin sheathing 14 is formed except for the portions where the terminals are drawn out to obtain a piezoelectric resonance component 15. ..
【００１８】樹脂外装１４を形成した後に、最初の分極
方法と同一方向に３００Ｖ／１８０μｍで６０秒、室温
にて直流電界を印加した。その結果、図１０（ｂ）に示
すように圧電板１３の電極１１，１２が重なり合ってい
る部分において分極度が回復し、図１のｃに示すように
初期の分極度に回復した。この様に、図１０（ｂ）に示
すように、分極が回復されるのは、電極１２，１３が重
なり合っている部分だけであるため、部分分極状態とな
り、圧電板１３において周辺の不要部分の分極は回復し
ないため、該不要部分における振動を抑制し得ることが
わかる。After forming the resin sheath 14, a DC electric field was applied at room temperature for 60 seconds at 300 V / 180 μm in the same direction as in the first polarization method. As a result, as shown in FIG. 10B, the polarization degree was recovered in the portion where the electrodes 11 and 12 of the piezoelectric plate 13 were overlapped with each other, and the initial polarization degree was recovered as shown in c of FIG. As described above, as shown in FIG. 10B, the polarization is restored only in the portion where the electrodes 12 and 13 are overlapped with each other, so that the partial polarization state occurs, and the unnecessary portion in the periphery of the piezoelectric plate 13 is lost. Since the polarization does not recover, it is understood that the vibration in the unnecessary portion can be suppressed.
【００１９】比較のために、図１１（ａ）に示すよう
に、上記と同一材料からなり、ただし分極処理を施して
いない圧電板２３を用意し、該圧電板２３の両主面に部
分電極２１，２２を形成し、樹脂外装２４を施し、圧電
共振部品２５を得た。そして、得られた圧電共振部品２
５について、製品状態のまま電極２１，２２から５４０
Ｖ／１８０μｍ及び３０分の条件で分極を行ったとこ
ろ、分極度はほとんど向上しないことが確かめられた。
また、この様にして得られた圧電共振部品２５のインピ
ーダンス−周波数特性を測定したところ、波形に大きな
乱れが生じていた。従って、ソフトな圧電材料であるＰ
ｂ（Ｔｉ，Ｚｒ）Ｏ3 系の正方晶と三方晶の相境界に位
置する材料であっても、室温にて圧電板を部分分極する
には、非常に高い電圧を必要とすることがわかる。For comparison, as shown in FIG. 11 (a), a piezoelectric plate 23 made of the same material as above but not subjected to polarization treatment is prepared, and partial electrodes are provided on both main surfaces of the piezoelectric plate 23. 21 and 22 were formed, and the resin sheath 24 was applied to obtain a piezoelectric resonance component 25. Then, the obtained piezoelectric resonance component 2
For No. 5, the electrodes 21, 22 to 540 in the product state
When polarization was performed under the conditions of V / 180 μm and 30 minutes, it was confirmed that the degree of polarization was hardly improved.
Further, when the impedance-frequency characteristics of the piezoelectric resonance component 25 thus obtained were measured, a large disturbance was generated in the waveform. Therefore, the soft piezoelectric material P
It can be seen that even a material located at the phase boundary between the b (Ti, Zr) O 3 system tetragonal and trigonal crystals requires a very high voltage to partially polarize the piezoelectric plate at room temperature. ..
【００２０】これに対して、前述した実施例では、抗電
界を超える比較的低い直流電界を印加するだけで所望の
分極度が実現されるため、本実施例の製造方法によれ
ば、部分分極に挟まれた圧電板領域を所望の分極度に極
めて簡単に分極し得ることがわかる。また、上記実施例
の各工程後における分極Ｐ及びそのバラツキを調べたと
ころ、図１２に示す結果が得られた。図１２から明らか
なように、本実施例では、分極バラツキの小さい圧電共
振部品の得られることがわかる。On the other hand, in the above-described embodiment, the desired polarization degree can be realized only by applying a relatively low DC electric field exceeding the coercive electric field. Therefore, according to the manufacturing method of this embodiment, the partial polarization is achieved. It can be seen that the piezoelectric plate region sandwiched by the can be extremely easily polarized to a desired degree of polarization. Further, when the polarization P and its variation after each step of the above-described example were examined, the results shown in FIG. 12 were obtained. As is clear from FIG. 12, in this example, it is found that a piezoelectric resonance component with small polarization variation can be obtained.
【図１】実施例において圧電板を分極する工程を説明す
るための模式図。FIG. 1 is a schematic diagram for explaining a process of polarizing a piezoelectric plate in an example.
【図２】従来例の問題点を説明するための図であり、分
極Ｐと温度との関係を示す図。FIG. 2 is a diagram for explaining a problem of a conventional example, and is a diagram showing a relationship between polarization P and temperature.
【図３】従来の分極方法により得られる圧電共振部品の
各工程における分極Ｐの大きさ及びばらつきを示す図。FIG. 3 is a diagram showing the magnitude and variation of polarization P in each step of a piezoelectric resonance component obtained by a conventional polarization method.
【図４】（ａ〜ｃ）は、本発明の分極方法を説明するた
めの各模式的断面図。4A to 4C are schematic cross-sectional views for explaining the polarization method of the present invention.
【図５】本発明の分極方法を説明するための図であり、
圧電共振部品の縦断面図。FIG. 5 is a diagram for explaining the polarization method of the present invention,
FIG. 3 is a vertical sectional view of a piezoelectric resonance component.
【図６】本発明の分極方法における各工程における圧電
板の分極状態を説明するための模式図。FIG. 6 is a schematic diagram for explaining the polarization state of the piezoelectric plate in each step in the polarization method of the present invention.
【図７】初期分極状態及びバイアス電界を印加した場合
の圧電板のインピーダンス−周波数特性を示す図。FIG. 7 is a diagram showing impedance-frequency characteristics of a piezoelectric plate when an initial polarization state and a bias electric field are applied.
【図８】初期分極状態及び最終的に得られた圧電板のイ
ンピーダンス−周波数特性を示す図。FIG. 8 is a diagram showing an initial polarization state and impedance-frequency characteristics of a finally obtained piezoelectric plate.
【図９】本発明の分極方法により得られる圧電共振部品
における共振周波数と共振点−***振点間の周波数差と
の関係を示す図。FIG. 9 is a diagram showing the relationship between the resonance frequency and the frequency difference between the resonance point and the anti-resonance point in the piezoelectric resonance component obtained by the polarization method of the present invention.
【図１０】（ａ）及び（ｂ）は実施例の圧電共振部品の
分極方法を説明するための各縦断面図。10A and 10B are vertical cross-sectional views for explaining a polarization method of the piezoelectric resonance component of the example.
【図１１】（ａ）及び（ｂ）は、比較例において圧電共
振部品を分極する工程を説明するための各縦断面図。11A and 11B are vertical cross-sectional views for explaining a step of polarizing a piezoelectric resonance component in a comparative example.
【図１２】実施例の各工程における分極Ｐ及びそのばら
つきを示す模式図。FIG. 12 is a schematic diagram showing polarization P and its variation in each step of the example.
１…圧電体 ２，３…分極用の電極 ４，５…電極 ６…外装樹脂 ７…圧電共振部品 １１，１２…電極 １３…圧電体 １４…外装樹脂 １５…圧電共振部品 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric body 2, 3 ... Electrode for polarization 4, 5 ... Electrode 6 ... Exterior resin 7 ... Piezoelectric resonance component 11, 12 ... Electrode 13 ... Piezoelectric body 14 ... Exterior resin 15 ... Piezoelectric resonance component
Claims (1)
の分極度を有するように分極処理する工程と、 前記分極処理に続いて、逆方向にバイアス電界を印加す
ることにより圧電体の分極度を第１の分極度の１／１０
以下とする工程と、 分極度の低下された圧電体の両主面に電極を形成する工
程と、 前記電極が形成された圧電体を用いて圧電部品を構成す
る工程と、 前記圧電部品を構成する工程を終えた後に、前記電極か
ら前記圧電体に対し第１の分極度を得た場合の分極処理
と同一方向に抗電界を超える電界を印加し部分分極によ
り所望の分極度を得る工程とを備える、圧電体の分極方
法。1. A piezoelectric body is polarized in a certain direction,
And a polarization process of applying a bias electric field in the opposite direction after the polarization process, so that the polarization degree of the piezoelectric body is 1/10 of the first polarization degree.
The following steps, a step of forming electrodes on both main surfaces of the piezoelectric body having a reduced polarization degree, a step of forming a piezoelectric component using the piezoelectric body on which the electrodes are formed, and a step of forming the piezoelectric component. And a step of obtaining a desired polarization degree by partial polarization by applying an electric field exceeding the coercive electric field in the same direction as the polarization treatment when the first polarization degree is obtained from the electrode to the piezoelectric body after the step of A method for polarizing a piezoelectric body, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32311391A JP2830556B2 (en) | 1991-12-06 | 1991-12-06 | Polarization method of piezoelectric body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32311391A JP2830556B2 (en) | 1991-12-06 | 1991-12-06 | Polarization method of piezoelectric body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05160464A true JPH05160464A (en) | 1993-06-25 |
| JP2830556B2 JP2830556B2 (en) | 1998-12-02 |
Family
ID=18151230
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32311391A Expired - Fee Related JP2830556B2 (en) | 1991-12-06 | 1991-12-06 | Polarization method of piezoelectric body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2830556B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006013304A (en) * | 2004-06-29 | 2006-01-12 | Murata Mfg Co Ltd | Manufacturing method of piezo-electric element |
| JP2009000864A (en) * | 2007-06-20 | 2009-01-08 | Ricoh Printing Systems Ltd | Liquid discharge head, its manufacturing method and image formation device |
| JP2009529833A (en) * | 2006-03-07 | 2009-08-20 | アジャイル アールエフ，インク． | Switchable and tunable acoustic resonator using BST material |
-
1991
- 1991-12-06 JP JP32311391A patent/JP2830556B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006013304A (en) * | 2004-06-29 | 2006-01-12 | Murata Mfg Co Ltd | Manufacturing method of piezo-electric element |
| JP2009529833A (en) * | 2006-03-07 | 2009-08-20 | アジャイル アールエフ，インク． | Switchable and tunable acoustic resonator using BST material |
| JP2009000864A (en) * | 2007-06-20 | 2009-01-08 | Ricoh Printing Systems Ltd | Liquid discharge head, its manufacturing method and image formation device |
| US9009973B2 (en) | 2007-06-20 | 2015-04-21 | Ricoh Company, Ltd. | Method of manufacturing liquid discharging head |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2830556B2 (en) | 1998-12-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7414349B2 (en) | Piezoelectric vibrator, filter using the same and its adjusting method | |
| US6239536B1 (en) | Encapsulated thin-film resonator and fabrication method | |
| Berlincourt et al. | Piezoelectric effect in the ferroelectric range in SbSI | |
| Berlincourt | Variation of electroelastic constants of polycrystalline lead titanate zirconate with thoroughness of poling | |
| JPH02312310A (en) | Piezoelectric parts and manufacture thereof | |
| JPH05160464A (en) | Method of polarizing piezoelectric substance | |
| JP3478227B2 (en) | Polarization method of piezoelectric body | |
| JP3733861B2 (en) | Method for polarizing laminated piezoelectric material | |
| JP2000183422A (en) | Method for polarizing piezoelectric body | |
| JP2783022B2 (en) | Polarization method of piezoelectric body | |
| JPS63100807A (en) | Manufacture of piezoelectric ceramic resonator | |
| JPH04273186A (en) | Polarization method of block-like piezoelectric | |
| JPS6134279B2 (en) | ||
| JPH0482310A (en) | Polarization method for piezoelectric body | |
| JP3760766B2 (en) | Manufacturing method of ceramic oscillator | |
| JPH01232811A (en) | Manufacture of piezoelectric vibrator | |
| JPH06260696A (en) | Partially polarizing method for piezoelectric element | |
| JPH05243884A (en) | Polarizing method for piezoelectric body | |
| JPH01232812A (en) | Method for forming lithium tantalate wafer polarized inverting layer | |
| JPH0758569A (en) | Frequency adjustment method for piezoelectric oscillating element | |
| JP2910095B2 (en) | Piezoelectric element and method of manufacturing piezoelectric element | |
| JPS6148299A (en) | Manufacture of ultrasonic probe | |
| JPS5948560B2 (en) | Method for manufacturing piezoelectric ceramic elements | |
| Jianbo et al. | Study on New Poling Technology of the Piezoelectric Ceramic Filter | |
| JPH0490610A (en) | Frequency adjusting method for combination piezoelectric porcelain resonators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080925 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080925 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090925 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090925 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100925 Year of fee payment: 12 |
|
| LAPS | Cancellation because of no payment of annual fees |