JP2000340851A - Piezoelectric element - Google Patents
Piezoelectric elementInfo
- Publication number
- JP2000340851A JP2000340851A JP11148221A JP14822199A JP2000340851A JP 2000340851 A JP2000340851 A JP 2000340851A JP 11148221 A JP11148221 A JP 11148221A JP 14822199 A JP14822199 A JP 14822199A JP 2000340851 A JP2000340851 A JP 2000340851A
- Authority
- JP
- Japan
- Prior art keywords
- surface electrode
- piezoelectric
- piezoelectric material
- piezoelectric element
- hardness
- 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.)
- Pending
Links
- 239000000463 material Substances 0.000 claims abstract description 74
- 238000000034 method Methods 0.000 claims abstract description 10
- 229910052751 metal Inorganic materials 0.000 claims abstract description 8
- 239000002184 metal Substances 0.000 claims abstract description 8
- 238000007772 electroless plating Methods 0.000 claims abstract description 7
- 238000007740 vapor deposition Methods 0.000 claims abstract description 4
- 238000004544 sputter deposition Methods 0.000 claims abstract description 3
- 238000005219 brazing Methods 0.000 claims description 6
- 230000000694 effects Effects 0.000 abstract description 15
- 238000012546 transfer Methods 0.000 abstract description 2
- 238000007747 plating Methods 0.000 description 23
- 238000006073 displacement reaction Methods 0.000 description 16
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 13
- 239000000243 solution Substances 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 11
- 230000005540 biological transmission Effects 0.000 description 9
- 239000010949 copper Substances 0.000 description 6
- 230000000452 restraining effect Effects 0.000 description 6
- 239000000956 alloy Substances 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 5
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 239000012190 activator Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 238000000605 extraction Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- -1 BAu Substances 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- BRZANEXCSZCZCI-UHFFFAOYSA-N Nifenazone Chemical compound O=C1N(C=2C=CC=CC=2)N(C)C(C)=C1NC(=O)C1=CC=CN=C1 BRZANEXCSZCZCI-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 235000010724 Wisteria floribunda Nutrition 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000009774 resonance method Methods 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
Landscapes
- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
Abstract
Description
【０００１】[0001]
【技術分野】本発明は，アクチュエータ等に用いられる
圧電素子に関する。TECHNICAL FIELD The present invention relates to a piezoelectric element used for an actuator or the like.
【０００２】アクチュエータ等に用いられる従来の圧電
素子９は，図６に示すごとく，圧電セラミックス等の圧
電材料１０の両面に表面電極としてのＡｇペースト焼き
付け電極９２を配設してなる。そして，Ａｇペースト焼
き付け電極９２に取り出し電極３をそれぞれ接触させ
て，外部と電気的導通を図っている。2. Description of the Related Art As shown in FIG. 6, a conventional piezoelectric element 9 used for an actuator or the like has an Ag paste firing electrode 92 as a surface electrode on both surfaces of a piezoelectric material 10 such as a piezoelectric ceramic. Then, the lead-out electrodes 3 are brought into contact with the Ag paste baked electrodes 92, respectively, to achieve electrical continuity with the outside.
【０００３】圧電素子９をアクチュエータとして用いる
場合には，取り出し電極３の間に電圧を付与することに
より，圧電材料１０を逆圧電効果により変形させる。こ
の変形力を利用することにより，圧電素子９はアクチュ
エータとして機能する。また，圧電素子９はこれを積層
して用いられる場合もある。また，圧電素子９をセンサ
として利用することもできる。この場合には，圧電素子
９に付与される応力を，上記取り出し電極３から電気的
な出力として取り出す。When the piezoelectric element 9 is used as an actuator, a voltage is applied between the extraction electrodes 3 to deform the piezoelectric material 10 by an inverse piezoelectric effect. By utilizing this deformation force, the piezoelectric element 9 functions as an actuator. Further, the piezoelectric element 9 may be used by laminating it. Further, the piezoelectric element 9 can be used as a sensor. In this case, the stress applied to the piezoelectric element 9 is extracted from the extraction electrode 3 as an electrical output.
【０００４】[0004]
【解決しようとする課題】ところで，上記従来の圧電素
子９においては，次の問題がある。即ち，上記圧電材料
１０に配設したＡｇペースト焼き付け電極９２は，Ａｇ
粉とガラスフリット等を含有したＡｇペーストを塗布し
て焼き付けることにより形成される。そのため，圧電材
料１０とＡｇとの界面に上記ガラスフリット等からなる
高抵抗層が形成される。この高抵抗層は，例えば圧電素
子９をアクチュエータとして利用する際に，Ａｇペース
ト焼き付け電極９２を介して圧電材料１０に印加される
電圧の伝達効率を悪化させる要因となり，圧電素子１の
圧電特性を低下させる。However, the conventional piezoelectric element 9 has the following problems. That is, the Ag paste baking electrode 92 disposed on the piezoelectric material 10
It is formed by applying and baking an Ag paste containing powder and glass frit. Therefore, a high-resistance layer made of the glass frit or the like is formed at the interface between the piezoelectric material 10 and Ag. This high-resistance layer becomes a factor of deteriorating the transmission efficiency of the voltage applied to the piezoelectric material 10 via the Ag paste burning electrode 92 when the piezoelectric element 9 is used as an actuator, for example, and the piezoelectric characteristics of the piezoelectric element 1 are reduced. Lower.
【０００５】一方，圧電材料１０に配設する表面電極
は，逆圧電効果により変形する圧電材料１０と密着して
いるので，その変形の抵抗となりうる。この抵抗が大き
くなれば，表面電極から圧電材料１０への電圧の伝達効
率が向上しても，表面電極が受ける拘束力により逆圧電
効果による変形が妨げられる。そこで，従来より，Ａｇ
ペースト焼き付け電極よりも圧電材料への電圧伝達性に
優れ，かつ，Ａｇペースト焼き付け電極と同等以上に拘
束力が小さい表面電極を有する圧電素子の開発が望まれ
ていた。On the other hand, since the surface electrode provided on the piezoelectric material 10 is in close contact with the piezoelectric material 10 which is deformed by the inverse piezoelectric effect, it can be a resistance to the deformation. If this resistance increases, even if the transmission efficiency of the voltage from the surface electrode to the piezoelectric material 10 is improved, deformation due to the inverse piezoelectric effect is hindered by the restraining force applied to the surface electrode. Therefore, conventionally, Ag
There has been a demand for the development of a piezoelectric element having a surface electrode which is superior to the paste-baked electrode in voltage transfer to the piezoelectric material and has a binding force smaller than or equal to that of the Ag paste-baked electrode.
【０００６】本発明は，かかる従来の問題点に鑑みてな
されたもので，表面電極から圧電材料への電圧の伝達効
率に優れ，かつ，圧電材料の逆圧電効果を効率よく引き
出すことができる圧電素子を提供しようとするものであ
る。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made in view of the above-mentioned problems. It is intended to provide an element.
【０００７】[0007]
【課題の解決手段】請求項１の発明は，圧電材料と該圧
電材料の表面に介在物を介することなく直接接合してな
る金属よりなる表面電極を有してなり，該表面電極はそ
の硬さＨｖが５００以下であることを特徴とする圧電素
子にある。According to a first aspect of the present invention, there is provided a piezoelectric material having a surface electrode made of a metal which is directly bonded to the surface of the piezoelectric material without any intervening material, and the surface electrode is formed of a hard material. The piezoelectric element is characterized in that Hv is 500 or less.
【０００８】本発明において最も注目すべきことは，上
記特定の硬度を有する表面電極を，圧電材料の表面に直
接接合した金属により構成したことである。ここで，直
接接合とは，上記のごとく，介在物を介することなく圧
電材料に表面電極を形成させることを意味する。例え
ば，従来のＡｇペースト焼き付け電極に含有されるガラ
スフリット等の介在物は使用しない。What is most remarkable in the present invention is that the surface electrode having the specific hardness is made of a metal directly bonded to the surface of a piezoelectric material. Here, the direct bonding means that the surface electrode is formed on the piezoelectric material without any intervening material as described above. For example, no inclusion such as glass frit contained in a conventional Ag paste baking electrode is used.
【０００９】また，上記表面電極としては，導電性に優
れた材料であれば，種々の金属（合金を含む）を用いる
ことができる。そして，予め膜状に作製した表面電極材
を圧電材料に接合することもできるし，また，膜状の表
面電極を圧電材料の表面において形成することにより，
表面電極の形成と圧電材料への接合を同時に行うことも
できる。As the surface electrode, various metals (including alloys) can be used as long as the material has excellent conductivity. In addition, the surface electrode material prepared in a film shape in advance can be bonded to the piezoelectric material, and the film-shaped surface electrode can be formed on the surface of the piezoelectric material.
The formation of the surface electrode and the bonding to the piezoelectric material can be performed simultaneously.
【００１０】また，上記表面電極は，その硬さＨｖが５
００以下となるよう軟らかく設ける。硬さＨｖが５００
を越える場合には，圧電材料の逆圧電効果による変形の
拘束力が大きくなりすぎるという問題がある。The surface electrode has a hardness Hv of 5
It is provided softly so as to be 00 or less. Hardness Hv is 500
In the case of exceeding, there is a problem that the restraining force of the deformation due to the inverse piezoelectric effect of the piezoelectric material becomes too large.
【００１１】また，上記圧電材料としては，例えば，Ｐ
ＺＴ（チタン酸ジルコン酸鉛），ＢａＴｉＯ3（チタン
酸バリウム），ＬｉＴａＯ3，ＳｒXＢａ1-X，Ｎｂ
2Ｏ6，ＰｂＺｒＯ3，ＰＶＤＦ＋ＰＺＴ，Ｌｉ2Ｎｂ
Ｏ3，Ｌｉ2Ｂ4Ｏ7，Ｔｌ3ＶＳ4等がある。Further, as the piezoelectric material, for example, P
ZT (lead zirconate titanate), BaTiO 3 (barium titanate), LiTaO 3 , Sr x Ba 1-x , Nb
2 O 6 , PbZrO 3 , PVDF + PZT, Li 2 Nb
O 3 , Li 2 B 4 O 7 , Tl 3 VS 4 and the like.
【００１２】次に，本発明の作用効果につき説明する。
本発明の圧電素子においては，上記のごとく，Ｈｖ５０
０以下の軟らかい表面電極を上記圧電材料に直接接合し
てなる。そのため，表面電極から圧電材料への電圧の伝
達効率を向上させることができ，かつ，圧電材料の逆圧
電効果を阻害することなく効率よく引き出すことができ
る。Next, the operation and effect of the present invention will be described.
In the piezoelectric element of the present invention, as described above, Hv50
A soft surface electrode of 0 or less is directly bonded to the piezoelectric material. Therefore, the transmission efficiency of the voltage from the surface electrode to the piezoelectric material can be improved, and the piezoelectric material can be efficiently extracted without disturbing the inverse piezoelectric effect.
【００１３】即ち，上記表面電極は金属よりなると共に
圧電材料に直接接合されている。そのため，従来のＡｇ
ペースト焼き付け電極の場合に形成されたような高抵抗
層が形成されることがない。そのため，表面電極を介し
て印加される電圧は，表面電極の優れた導電性をそのま
ま生かして効率よく圧電材料に伝達される。That is, the surface electrode is made of metal and is directly bonded to the piezoelectric material. Therefore, the conventional Ag
There is no formation of a high-resistance layer as in the case of paste-baked electrodes. Therefore, the voltage applied via the surface electrode is efficiently transmitted to the piezoelectric material while taking advantage of the excellent conductivity of the surface electrode.
【００１４】また，上記表面電極は硬さＨｖが５００以
下と軟らかい状態で形成されている。そのため，圧電材
料が逆圧電効果による変形を起こす場合に，それに伴っ
て表面電極が変形しやすく，表面電極により拘束される
力が小さくなる。それ故，上記の電圧の伝達効率の向上
と変形拘束力の低下の相乗効果によって，圧電材料の逆
圧電効果を効率よく引き出すことができる。The surface electrode is formed in a soft state with a hardness Hv of 500 or less. Therefore, when the piezoelectric material is deformed due to the inverse piezoelectric effect, the surface electrode is easily deformed accordingly, and the force restrained by the surface electrode is reduced. Therefore, the inverse piezoelectric effect of the piezoelectric material can be efficiently obtained by the synergistic effect of the improvement of the voltage transmission efficiency and the reduction of the deformation restraining force.
【００１５】なお，上記作用効果は上記圧電素子をアク
チュエータとして用いる場合について示した。しかしな
がら，上記構成を有する上記圧電素子は，これをセンサ
として用いる場合においても，表面電極における導電性
の向上および拘束力の低下により，その圧電特性を従来
よりも向上させることができる。The above operation and effect have been described for the case where the above piezoelectric element is used as an actuator. However, even when the piezoelectric element having the above configuration is used as a sensor, its piezoelectric characteristics can be improved as compared with conventional piezoelectric elements by improving the conductivity of the surface electrode and reducing the binding force.
【００１６】次に，請求項２の発明のように，上記表面
電極の厚さは２μｍ以下であることが好ましい。この場
合には，さらに，上記圧電材料の変形を表面電極により
拘束する力を小さくすることができ，圧電素子の圧電特
性をより一層向上させることができる。Next, the thickness of the surface electrode is preferably 2 μm or less. In this case, the force for restraining the deformation of the piezoelectric material by the surface electrode can be further reduced, and the piezoelectric characteristics of the piezoelectric element can be further improved.
【００１７】また，請求項３の発明のように，上記表面
電極は，無電解メッキ法，スパッタ法，あるいは蒸着法
により形成されていることが好ましい。この場合には，
表面電極自体の形成と，これの圧電材料への接合を同時
に行うことができる。そのため，表面電極の圧電材料へ
の直接接合を容易かつ確実に行うことができる。ここ
で，上記蒸着法としては，いわゆるＣＶＤ法，ＰＶＤ法
等の種々の方法がある。Further, it is preferable that the surface electrode is formed by an electroless plating method, a sputtering method, or a vapor deposition method. In this case,
It is possible to simultaneously form the surface electrode itself and join it to the piezoelectric material. Therefore, direct bonding of the surface electrode to the piezoelectric material can be easily and reliably performed. Here, as the vapor deposition method, there are various methods such as a so-called CVD method and a PVD method.
【００１８】また，請求項４の発明のように，上記表面
電極は，ろう材により構成することもできる。この場合
にも，電圧の伝達効率向上と上記拘束力の低減を図るこ
とができる。ろう材としては，例えば，ＢＡｇ系（ＪＩ
Ｓ規格）の合金，ＢＡｕ，Ｎｉ，Ｐｔ，Ｐｄ，Ｒｕ，Ｒ
ｈ等を適用することができる。The surface electrode may be made of a brazing material. Also in this case, it is possible to improve the voltage transmission efficiency and reduce the binding force. As the brazing material, for example, BAg-based (JI
S standard) alloy, BAu, Ni, Pt, Pd, Ru, R
h etc. can be applied.
【００１９】[0019]
【発明の実施の形態】実施形態例１ 本発明の実施形態例にかかる圧電素子につき，図１を用
いて説明する。本例の圧電素子１は，図１に示すごと
く，圧電材料１０と該圧電材料１０の表面に介在物を介
することなく直接接合してなる表面電極２よりなり，該
表面電極２はその硬さＨｖが５００以下である。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A piezoelectric element according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the piezoelectric element 1 of this embodiment comprises a piezoelectric material 10 and a surface electrode 2 directly bonded to the surface of the piezoelectric material 10 without any intervening material, and the surface electrode 2 has a hardness. Hv is 500 or less.
【００２０】以下，この圧電素子１について詳説する。
上記圧電材料１０としては，ＰＺＴ（チタン酸ジルコン
酸鉛）よりなる圧電セラミックを用いた。この圧電材料
１０の作製は，市販の原料粉末（ＰＥ５１０，富士チタ
ン工業製）を出発原料として用いて行った。まずこの原
料粉末を，直径φ１２ｍｍ×厚さ０．５ｍｍの円盤状に
成形した。次いで，これを大気中において１２００℃×
４時間の条件で焼成した。次に，得られた焼成体の表面
を＃６００のダイヤモンド砥石により研磨することによ
り，圧電材料１０を得た。Hereinafter, the piezoelectric element 1 will be described in detail.
As the piezoelectric material 10, a piezoelectric ceramic made of PZT (lead zirconate titanate) was used. The production of the piezoelectric material 10 was performed using a commercially available raw material powder (PE510, manufactured by Fuji Titanium Industry Co., Ltd.) as a starting material. First, this raw material powder was formed into a disk shape having a diameter of 12 mm and a thickness of 0.5 mm. Then, this is 1200 ° C. in the atmosphere.
The firing was performed for 4 hours. Next, the surface of the obtained fired body was polished with a # 600 diamond grindstone to obtain a piezoelectric material 10.
【００２１】次に，圧電材料１０の両面に表面電極２を
配設した。本例では，次の要領で無電解メッキ法を実施
してＮｉよりなる表面電極２を設けた。 （１）脱脂；温度５０℃の処理液（エースクリーンA-22
0，奥野製薬製）に圧電材料１０を３分間浸漬した。 （２）エッチング；温度２５℃の４２％ホウフッ化水素
酸の希釈液に圧電材料１０を６０秒間浸漬した。 （３）ディスマット；温度２５℃のディスマットＴＹ
（スマット除去材）に圧電材料１０を２分間浸漬した。Next, the surface electrodes 2 were provided on both surfaces of the piezoelectric material 10. In the present example, the surface electrode 2 made of Ni was provided by performing electroless plating in the following manner. (1) Degreasing; treatment liquid at a temperature of 50 ° C (A-screen A-22
0, manufactured by Okuno Pharmaceutical Co., Ltd.) for 3 minutes. (2) Etching; The piezoelectric material 10 was immersed in a dilute solution of 42% borofluoric acid at a temperature of 25 ° C. for 60 seconds. (3) Dismat; Dismat TY at 25 ° C
The piezoelectric material 10 was immersed in the (smut removing material) for 2 minutes.
【００２２】（４）センシダイザー；温度２５℃のセン
シダイザーの処理液に圧電材料１０を３分間浸漬した。
ここで，上記センシダイザーの処理液は，不動体表面に
還元力の強い第１スズイオンを吸着させるものである。 （５）アクテベータ；温度２５℃のアクテベータの処理
液に圧電材料１０を１分間浸漬した。ここで，上記アク
テベータの処理液は，不動体表面に触媒となる金属層を
形成するものである。 （６）センシダイザー；上記（４）と同じ。 （７）アクテベータ；上記（５）と同じ。(4) Sensidizer: The piezoelectric material 10 was immersed in a processing solution of a sensidizer at a temperature of 25 ° C. for 3 minutes.
Here, the processing liquid of the above-mentioned sensitizer adsorbs stannous ions having strong reducing power on the surface of the passive body. (5) Activator: The piezoelectric material 10 was immersed in an activator treatment solution at a temperature of 25 ° C. for 1 minute. Here, the treatment liquid of the activator forms a metal layer serving as a catalyst on the surface of a passive body. (6) Sensidizer; same as (4) above. (7) Activator; same as (5) above.
【００２３】（８）無電解ニッケルメッキ；Ｐを１０％
含有したメッキ浴液ニコロンSA-98-MとニコロンSA-98-1
との混合液を温度９０℃に保持し，該混合液よりなるメ
ッキ浴液に圧電材料１０を所定時間浸漬することにより
Ｎｉメッキ膜を形成した。本例では，メッキ浴液への浸
漬時間を８分として，Ｎｉメッキ膜厚，すなわち表面電
極２の厚さを２μｍとした。これにより，圧電材料１０
とその表面に介在物を介することなく直接接合してなる
表面電極２を設けた圧電素子１（本発明品Ｅ１）が得ら
れた。なお，上記表面電極２はその硬さＨｖが５００で
あった。(8) Electroless nickel plating; P is 10%
Nicolon SA-98-M and Nicolon SA-98-1
Is maintained at a temperature of 90 ° C., and the Ni plating film is formed by immersing the piezoelectric material 10 in a plating bath solution of the mixed solution for a predetermined time. In this example, the immersion time in the plating bath solution was 8 minutes, and the thickness of the Ni plating, that is, the thickness of the surface electrode 2 was 2 μm. Thereby, the piezoelectric material 10
And a piezoelectric element 1 (product E1 of the present invention) provided with a surface electrode 2 directly joined to the surface thereof without any intervening substance. The hardness Hv of the surface electrode 2 was 500.
【００２４】次に，本例においては，本発明品Ｅ１とし
ての上記圧電材料１の圧電特性の向上効果を評価するた
め，上記表面電極２と同じ厚みのＡｇペースト焼き付け
電極を有する比較品Ｃ１を作製した。この比較品Ｃ１
は，ガラスフリット成分を含有したＡｇペーストを上記
圧電材料１０の表面に塗布し，これを焼成することによ
り厚さ２μｍのＡｇペースト焼き付け電極を設けたもの
である。このＡｇペースト焼き付け電極の硬さＨｖは３
０であった。Next, in this example, in order to evaluate the effect of improving the piezoelectric characteristics of the piezoelectric material 1 as the product E1 of the present invention, a comparative product C1 having an Ag paste baked electrode having the same thickness as the surface electrode 2 was used. Produced. This comparative product C1
Is a method in which an Ag paste containing a glass frit component is applied to the surface of the piezoelectric material 10 and baked to provide a 2 μm-thick Ag paste firing electrode. The hardness Hv of this Ag paste baked electrode is 3
It was 0.
【００２５】次に，本発明品Ｅ１及び比較品Ｃ１の圧電
特性として，Ｋｐ及び変位量を測定した。Ｋｐは，電気
機械結合係数であり，共振・反共振法より求めた値であ
る。また，変位量は，圧電材料に電圧を印加したときに
逆圧電効果により電圧印加方向に変位する量である。ま
た，Ｋｐはインピーダンスアナライザー（ヒューレット
パッカード４１９４Ａ）を用いて，変位量は変位測定器
を用いて，印加電圧−２００／６００Ｖ，圧縮応力２０
ＭＰａ，周波数０．１Ｈｚ，温度は２５℃の条件で測定
した。Next, Kp and displacement were measured as piezoelectric characteristics of the product E1 of the present invention and the comparative product C1. Kp is an electromechanical coupling coefficient and is a value obtained by a resonance / anti-resonance method. Further, the displacement amount is a displacement amount in a voltage application direction due to a reverse piezoelectric effect when a voltage is applied to the piezoelectric material. Kp was measured using an impedance analyzer (Hewlett-Packard 4194A), and the displacement was measured using a displacement measuring instrument.
MPa, frequency 0.1 Hz, and temperature were measured at 25 ° C.
【００２６】測定の結果，Ｋｐは，本発明品Ｅ１が７１
％であり，比較品Ｃ１が６９％であった。また，変位量
は，本発明品Ｅ１が０．４μｍであり，比較品Ｃ１が
０．３４μｍであった。即ち，本発明品Ｅ１はＫｐ，変
位量のいずれにおいても比較品Ｃ１よりも優れた結果を
示した。As a result of the measurement, Kp was 71% for the product E1 of the present invention.
%, And the comparative product C1 was 69%. The displacement was 0.4 μm for the product E1 of the present invention and 0.34 μm for the comparative product C1. That is, the product E1 of the present invention showed superior results to the comparative product C1 in both Kp and displacement.
【００２７】この理由は次のように考えられる。即ち，
本発明品Ｅ１の表面電極２は，導電性に優れたＮｉメッ
キ膜よりなると共に，上記のごとく，圧電材料１０に直
接接合されている。そのため，比較例Ｃ１のＡｇペース
ト焼き付け電極の場合のような高抵抗層が表面電極２と
圧電材料１０との間に存在しない。そのため，表面電極
２から圧電材料１０への電圧の伝達効率を従来よりも向
上させることができる。The reason is considered as follows. That is,
The surface electrode 2 of the product E1 of the present invention is made of a Ni plating film having excellent conductivity, and is directly bonded to the piezoelectric material 10 as described above. Therefore, there is no high resistance layer between the surface electrode 2 and the piezoelectric material 10 as in the case of the Ag paste baked electrode of Comparative Example C1. Therefore, the transmission efficiency of the voltage from the surface electrode 2 to the piezoelectric material 10 can be improved as compared with the related art.
【００２８】また，上記表面電極２は，硬さＨｖが５０
０以下と比較的軟らかい状態で形成されている。そのた
め，圧電材料１０の逆圧電効果による変形を表面電極２
により拘束する力をＡｇペースト焼き付け電極なみに小
さくすることができる。それ故，本発明品Ｅ１は，表面
電極２における電圧の伝達効率の向上と変形拘束力の低
下によって，電圧の伝達効率が低いＡｇペースト焼き付
け電極を用いた比較品Ｃ１に比べて，圧電材料１０の逆
圧電効果をより効率よく引き出すことができる。The surface electrode 2 has a hardness Hv of 50.
It is formed in a relatively soft state of 0 or less. Therefore, the deformation of the piezoelectric material 10 due to the reverse piezoelectric effect
Thus, the restraining force can be made as small as that of the Ag paste baking electrode. Therefore, the product E1 of the present invention has the piezoelectric material 10 compared with the comparative product C1 using the Ag paste baked electrode having a low voltage transmission efficiency due to the improvement of the voltage transmission efficiency at the surface electrode 2 and the reduction of the deformation restraining force. The reverse piezoelectric effect can be more efficiently obtained.
【００２９】実施形態例２ 本例では，図２，図３に示すごとく，実施形態例１の圧
電素子１における，表面電極２の厚さと圧電特性の関係
を定量的に評価した。具体的には，実施形態例１におけ
る（８）無電解ニッケルメッキ処理において，メッキ浴
液への浸漬時間を４分，８分，１８分と変えてメッキ膜
厚（表面電極２の厚さ）を１μｍ，２μｍ，４μｍと変
化させた圧電素子をそれぞれ作製した。得られた表面電
極２の硬さはすべてＨｖ５００である。表面電極２の厚
さが１μｍのものを試料Ｅ２１，２μｍのものを試料Ｅ
２２，４μｍのものを試料Ｅ２３とする。Embodiment 2 In this embodiment, as shown in FIGS. 2 and 3, the relationship between the thickness of the surface electrode 2 and the piezoelectric characteristics of the piezoelectric element 1 of Embodiment 1 was quantitatively evaluated. Specifically, in the (8) electroless nickel plating treatment in the first embodiment, the plating film thickness (thickness of the surface electrode 2) was changed by changing the immersion time in the plating bath solution to 4 minutes, 8 minutes, and 18 minutes. Were changed to 1 μm, 2 μm, and 4 μm, respectively. The hardness of all the obtained surface electrodes 2 is Hv500. Sample E21 having a surface electrode 2 having a thickness of 1 μm and sample E having a thickness of 2 μm
A sample having a size of 22.4 μm is designated as Sample E23.
【００３０】各圧電素子の圧電特性としては，Ｋｐ及び
変位量を測定した。測定の条件は，実施形態例１と同様
とした。As the piezoelectric characteristics of each piezoelectric element, Kp and displacement were measured. The measurement conditions were the same as in the first embodiment.
【００３１】圧電特性の測定結果を図２及び図３に示
す。図２は，横軸に表面電極２の厚さ（μｍ）を，縦軸
にＫｐ（％）をとったものである。図３は，横軸に表面
電極２の厚さ（μｍ）を，縦軸に変位量（μｍ）をとっ
たものである。図２及び図３より知られるごとく，表面
電極２の厚みを２μｍ以下にすることにより，Ｋｐ及び
変位量により示される圧電特性をより一層向上させるこ
とができることが分かった。FIGS. 2 and 3 show the measurement results of the piezoelectric characteristics. FIG. 2 shows the thickness (μm) of the surface electrode 2 on the horizontal axis and Kp (%) on the vertical axis. In FIG. 3, the horizontal axis represents the thickness (μm) of the surface electrode 2 and the vertical axis represents the displacement (μm). As is known from FIGS. 2 and 3, it was found that by setting the thickness of the surface electrode 2 to 2 μm or less, the piezoelectric characteristics indicated by Kp and the amount of displacement can be further improved.
【００３２】実施形態例３ 本例では，図４，図５に示すごとく，実施形態例１の圧
電素子１における，表面電極２の硬さと圧電特性の関係
を定量的に評価した。具体的には，厚さを１μｍ又は２
μｍとし，硬さをＨｖ１５〜８００の範囲で変化させた
４種類の圧電素子を作製し，その圧電特性を測定した。
準備した圧電素子は，表面電極以外の部分は実施形態例
１と同様である。Embodiment 3 In this embodiment, as shown in FIGS. 4 and 5, in the piezoelectric element 1 of Embodiment 1, the relationship between the hardness of the surface electrode 2 and the piezoelectric characteristics was quantitatively evaluated. Specifically, the thickness is 1 μm or 2 μm.
Four types of piezoelectric elements were manufactured in which the hardness was set to μm and the hardness was changed in the range of Hv 15 to 800, and the piezoelectric characteristics were measured.
The portion of the prepared piezoelectric element other than the surface electrode is the same as that of the first embodiment.
【００３３】準備した圧電素子における表面電極の特徴
は次のとおりである。 （本発明品Ｅ３１）；硬さＨｖ＝１５，厚さ１μｍの金
蒸着膜。金は，イオンコーターにより製膜した。 （本発明品Ｅ３２）；硬さＨｖ＝３５，厚さ２μｍの銀
と銅の合金膜を拡散接合したもの。The characteristics of the surface electrode in the prepared piezoelectric element are as follows. (Product E31 of the present invention); a gold vapor-deposited film having a hardness of Hv = 15 and a thickness of 1 μm. Gold was formed by an ion coater. (Product E32 of the present invention); diffusion-bonded alloy film of silver and copper having a hardness of Hv = 35 and a thickness of 2 μm.
【００３４】（本発明品Ｅ３３）；硬さＨｖ＝４０，厚
さ２μｍの無電解Ｃｕメッキ膜。この場合の無電解メッ
キは，実施形態例１における上記（１）〜（７）と同様
の処理を行った後，ＯＰＣカッパーT-1とＯＰＣカッパ
ーT-2とＯＰＣカッパーT-3（いずれも奥野製薬製）の混
合液をメッキ浴液として用いて無電解メッキを行った。
無電解メッキ条件は，メッキ浴液の温度が６０℃，浸漬
時間が３０分という条件とした。(Product E33 of the present invention): An electroless Cu plating film having a hardness of Hv = 40 and a thickness of 2 μm. In the electroless plating in this case, after performing the same processing as the above (1) to (7) in the first embodiment, the OPC copper T-1, the OPC copper T-2, and the OPC copper T-3 (all) Electroless plating was performed using a mixed solution of Okuno Pharmaceutical Co., Ltd.) as a plating bath solution.
The electroless plating conditions were such that the temperature of the plating bath was 60 ° C. and the immersion time was 30 minutes.
【００３５】（本発明品Ｅ３４）；硬さＨｖ＝５００，
厚さ２μｍの無電解Ｎｉメッキ膜。実施形態例１と同じ
である。 （比較品Ｃ３１）；硬さＨｖ＝６００，厚さ２μｍの無
電解Ｎｉメッキ膜。メッキ浴液のＰ含有量を６％のメッ
キ浴液を用いてメッキ膜の硬度を高めたものである。メ
ッキ浴液は，Ｐを６％含有したICPニコロンUSD-MとICP
ニコロンUSD-1（奥野製薬製）の混合液である。(E34 of the invention); hardness Hv = 500,
An electroless Ni plating film having a thickness of 2 μm. This is the same as the first embodiment. (Comparative product C31): An electroless Ni plating film having a hardness of Hv = 600 and a thickness of 2 μm. The hardness of the plating film is increased by using a plating bath solution having a P content of 6% in the plating bath solution. The plating bath solution was ICP Nicoron USD-M containing 6% P and ICP
Nicolon USD-1 (Okuno Pharmaceutical).
【００３６】（比較品Ｃ３２）；硬さＨｖ＝８００，厚
さ２μｍの無電解Ｎｉメッキ膜。メッキ浴液のＰ含有量
を０とし，Ｂの含有量を０．５％としてさらにメッキ膜
の硬度を高めたものである。メッキ浴液は，Ｂ（ボロ
ン）を０．５％含有したケミアロイ66-Mとケミアロイ66
-1（奥野製薬製）の混合液である。(Comparative product C32): An electroless Ni plating film having a hardness of Hv = 800 and a thickness of 2 μm. The hardness of the plating film is further increased by setting the P content of the plating bath solution to 0 and the B content to 0.5%. The plating bath solutions were Chemialloy 66-M and Chemialloy 66 containing 0.5% B (boron).
-1 (Okuno Pharmaceutical).
【００３７】次に，各圧電素子（Ｅ３１〜Ｅ３４，Ｃ３
１，Ｃ３２）の圧電特性の測定結果を図４及び図５に示
す。図４は，横軸に表面電極２の硬さ（Ｈｖ）を，縦軸
にＫｐ（％）をとったものである。図５は，横軸に表面
電極２の硬さ（Ｈｖ）を，縦軸に変位量（μｍ）をとっ
たものである。図４及び図５より知られるごとく，表面
電極２の硬さをＨｖ＝５００以下にすることにより，Ｋ
ｐ及び変位量により示される圧電特性を向上させること
ができることが分かる。Next, each of the piezoelectric elements (E31 to E34, C3
1, and C32) are shown in FIGS. 4 and 5. FIG. 4 shows the hardness (Hv) of the surface electrode 2 on the horizontal axis and Kp (%) on the vertical axis. FIG. 5 shows the hardness (Hv) of the surface electrode 2 on the horizontal axis and the displacement (μm) on the vertical axis. As is known from FIGS. 4 and 5, by setting the hardness of the surface electrode 2 to Hv = 500 or less, K
It can be seen that the piezoelectric characteristics indicated by p and the amount of displacement can be improved.
【００３８】実施形態例４ 本例は，実施形態例１における無電解Ｎｉメッキ膜より
なる表面電極２に代えて，ろう材よりなる表面電極を用
いた例である。即ち，図１における表面電極２として，
圧電材料１０の表面に介在物を介することなくろう材を
直接接合してなる金属により構成した。即ち，ＢＡｇ系
（ＪＩＳ）のＡｇが７９％，Ｃｕが２１％の合金よりな
るろう材を用いて表面電極を形成した。Embodiment 4 This embodiment is an example in which a surface electrode made of a brazing material is used instead of the surface electrode 2 made of an electroless Ni plating film in the first embodiment. That is, as the surface electrode 2 in FIG.
The piezoelectric material 10 was made of a metal obtained by directly joining a brazing material to the surface of the piezoelectric material 10 without any intervening material. That is, the surface electrode was formed using a brazing alloy made of a BAg-based (JIS) alloy of 79% Ag and 21% Cu.
【００３９】まず，実施形態例１と同様にして圧電材料
１０を作製した。次いで，圧電材料１０の両面に，ＢＡ
ｇ粉末を樹脂と混合してペースト状にし，それをスクリ
ーン印刷により印刷した。その後，大気中で７００℃×
１０分で焼き付けて樹脂成分を除去して，拡散接合して
表面電極を設けた。得られた表面電極の厚さは２μｍ，
硬さＨｖは３５であった。First, a piezoelectric material 10 was manufactured in the same manner as in the first embodiment. Next, on both sides of the piezoelectric material 10, BA
g powder was mixed with a resin to form a paste, which was printed by screen printing. Then, in the air at 700 ℃
The resin component was removed by baking for 10 minutes, and diffusion bonding was performed to provide a surface electrode. The thickness of the obtained surface electrode is 2 μm,
Hardness Hv was 35.
【００４０】次に，得られた圧電素子（本発明品Ｅ４と
する）の圧電特性として，実施形態例１と同様にＫｐ及
び変位量を測定した。その結果，本発明品Ｅ４のＫｐは
７１％，変位量は０．４μｍであった。この特性は，実
施形態例１に示した比較品Ｃ１と比べて非常に優れたも
のとなった。Next, as the piezoelectric characteristics of the obtained piezoelectric element (referred to as the product E4 of the present invention), Kp and displacement were measured in the same manner as in the first embodiment. As a result, the product E4 of the present invention had a Kp of 71% and a displacement of 0.4 μm. This characteristic was much better than the comparative product C1 shown in the first embodiment.
【００４１】[0041]
【発明の効果】上述のごとく，本発明によれば，表面電
極から圧電材料への電圧の伝達効率に優れ，かつ，圧電
材料の逆圧電効果を効率よく引き出すことができる圧電
素子を提供することができる。As described above, according to the present invention, it is possible to provide a piezoelectric element which is excellent in voltage transmission efficiency from a surface electrode to a piezoelectric material and can efficiently extract the inverse piezoelectric effect of the piezoelectric material. Can be.
【図１】実施形態例１における，圧電素子の構成を示す
説明図。FIG. 1 is an explanatory diagram illustrating a configuration of a piezoelectric element according to a first embodiment.
【図２】実施形態例２における，表面電極の厚さとＫｐ
との関係を示す説明図。FIG. 2 shows the thickness of the surface electrode and Kp in Embodiment 2;
FIG.
【図３】実施形態例２における，表面電極の厚さと変位
量との関係を示す説明図。FIG. 3 is an explanatory diagram showing a relationship between a thickness of a surface electrode and an amount of displacement in a second embodiment.
【図４】実施形態例３における，表面電極の硬さとＫｐ
との関係を示す説明図。FIG. 4 shows the hardness of the surface electrode and Kp in Embodiment 3;
FIG.
【図５】実施形態例３における，表面電極の硬さと変位
量との関係を示す説明図。FIG. 5 is an explanatory diagram showing the relationship between the hardness of a surface electrode and the amount of displacement in a third embodiment.
【図６】従来例における，圧電素子の構成を示す説明
図。FIG. 6 is an explanatory diagram showing a configuration of a piezoelectric element in a conventional example.
１．．．圧電素子， １０．．．圧電材料， ２．．．表面電極， ３．．．取り出し電極， 1. . . 10. piezoelectric element, . . 1. Piezoelectric material, . . 2. surface electrode; . . Extraction electrode,
───────────────────────────────────────────────────── フロントページの続き (72)発明者 牧野 浩明 愛知県愛知郡長久手町大字長湫字横道41番 地の１ 株式会社豊田中央研究所内 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroaki Makino 41-41, Yokomichi, Nagakute-cho, Aichi-gun, Aichi-gun
Claims (4)
介することなく直接接合してなる金属よりなる表面電極
を有してなり，該表面電極はその硬さＨｖが５００以下
であることを特徴とする圧電素子。1. A surface electrode comprising a piezoelectric material and a metal directly joined to the surface of the piezoelectric material without any intervening material, wherein the surface electrode has a hardness Hv of 500 or less. A piezoelectric element characterized by the above-mentioned.
は２μｍ以下であることを特徴とする圧電素子。2. The piezoelectric element according to claim 1, wherein the thickness of the surface electrode is 2 μm or less.
は，無電解メッキ法，スパッタ法，あるいは蒸着法によ
り形成されていることを特徴とする圧電素子。3. The piezoelectric element according to claim 1, wherein the surface electrode is formed by an electroless plating method, a sputtering method, or a vapor deposition method.
う材により構成してあることを特徴とする圧電素子。4. The piezoelectric element according to claim 1, wherein the surface electrode is made of a brazing material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11148221A JP2000340851A (en) | 1999-05-27 | 1999-05-27 | Piezoelectric element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11148221A JP2000340851A (en) | 1999-05-27 | 1999-05-27 | Piezoelectric element |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000340851A true JP2000340851A (en) | 2000-12-08 |
Family
ID=15447995
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11148221A Pending JP2000340851A (en) | 1999-05-27 | 1999-05-27 | Piezoelectric element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000340851A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007149858A (en) * | 2005-11-25 | 2007-06-14 | Seiko Epson Corp | Piezoelectric element, liquid jet head using the same, and liquid jet device |
-
1999
- 1999-05-27 JP JP11148221A patent/JP2000340851A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007149858A (en) * | 2005-11-25 | 2007-06-14 | Seiko Epson Corp | Piezoelectric element, liquid jet head using the same, and liquid jet device |
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