JP3378396B2 - Ultrasonic probe - Google Patents
Ultrasonic probeInfo
- Publication number
- JP3378396B2 JP3378396B2 JP02895395A JP2895395A JP3378396B2 JP 3378396 B2 JP3378396 B2 JP 3378396B2 JP 02895395 A JP02895395 A JP 02895395A JP 2895395 A JP2895395 A JP 2895395A JP 3378396 B2 JP3378396 B2 JP 3378396B2
- Authority
- JP
- Japan
- Prior art keywords
- ultrasonic
- vibrator
- ultrasonic probe
- piezoelectric
- absorber
- 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
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Transducers For Ultrasonic Waves (AREA)
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明はパルスエコー法に用いる
超音波プローブに関し、特に低温から高温にわたって使
用可能な耐寒耐熱性を有する構造を持った超音波プロー
ブに関わる。
【０００２】
【従来の技術】超音波プローブは超音波を送受する圧電
体からなる振動子を備えている。この振動子の超音波送
受面とは反対の面に、プローブの分解能を向上させるた
めの超音波吸収材が通常接合されている。この超音波吸
収材と振動子を接合するのに従来のプローブは有機系接
着剤を用いている物が多い。そのため、液体窒素温度な
どの低温では接着剤が硬質化し、超音波の透過率が小さ
くなり、接着力が低下する。また、２００℃以上の高温
環境では接着剤が炭化、変質し、または接着力の低下が
生じ、使用出来ない。また、高温で使用可能なプローブ
の例として、振動子と超音波吸収材の接合に金属ロウに
よるロウ付けを用いた物が報告されている（超音波ＴＥ
ＣＨＮＯ１９９３年８月号Ｐ．７０−７１）。しかし、
金属ロウによるロウ付けは接合処理温度が高く、振動子
とロウ材の熱収差が大きくなる。そのため、接合後振動
子とロウ材、あるいはロウ材と超音波吸収材の間に大き
な残留応力が生じ、振動子の反り、破損が生じ易いとい
った問題点があった。
【０００３】
【発明が解決しようとする課題】上述したように、従来
の超音波プローブは、高温環境での使用ができず、ま
た、その破損が生じやすいという問題があった。本発明
は、このような問題に鑑みてなされたものであり、耐熱
性に優れ、信頼性の高い超音波プローブを提供すること
を目的とする。
【０００４】
【課題を解決するための手段および作用】本発明は、圧
電セラミック若しくは圧電単結晶からなる圧電体、およ
びこの圧電体の対向する面に形成された電極とからなる
振動子と、この振動子の振動面上に設けられチタン酸ア
ルミ系セラミックスからなる超音波吸収材と、前記振動
子および超音波吸収材を接合するための４３０℃以下の
融点を持つガラスとを具備することを特徴とする超音波
プローブである。
【０００５】すなわち、振動子と超音波吸収材との接合
にガラスを用いることを特徴としており、このようにす
ることで原子炉などの２００℃以上の環境下で用いる場
合に好適である。
【０００６】本発明における圧電体としては、通常超音
波プローブに用いるものであれば特に限定されず、例え
ば圧電セラミック、圧電単結晶などを用いることができ
るが、特に、高温環境下で使用する場合には、チタン酸
鉛、ジルコン酸チタン酸鉛などのチタン酸鉛系の圧電材
料やニオブ酸鉛などの圧電セラミック、あるいはニオブ
酸リチウム、タンタル酸リチウムなどの圧電単結晶とい
ったキュリー点の高い圧電材料を用いることが望まし
い。
【０００７】本発明における電極としては、導電体であ
れば特に限定されずに用いることができる。また圧電体
との接着性を高めるために、必要に応じ、複数の導電体
を積層することもできる。
【０００８】本発明における超音波吸収材は、前記圧電
体および電極からなる振動子から超音波が発生した際
の、残留振動を抑えることで、超音波プローブの分解能
を向上させるものである。したがって、前記振動子の振
動面上で、かつ超音波送受とは反対側に形成される。ま
た、超音波吸収材に用いられる材料としては、高温での
使用を考慮した場合、チタン酸アルミなどの多孔質セラ
ミックが耐熱性の面で好適である。
【０００９】本発明におけるガラスは、前記振動子と前
記超音波吸収材料を接合するための接合材である。この
ように、振動子と超音波吸収材料を接合する際に、接合
材としてガラスを用いることによって、液体窒素温度程
度の低温から、２００℃を越える高温での接合強度を維
持することが可能となる。
【００１０】また接合温度は接合材の融点よりも３０程
度高い温度で行われ、ガラスの融点は一般に５００℃以
下であり、ロウ材の融点（６００℃以上）よりも低く、
かつ被接合材となる前記圧電体や超音波吸収材と熱膨脹
係数が近いために、従来のロウ付けで生じていた接合面
の残留応力を小さくすることが可能となる。その結果、
製造工程における振動子の反りがなくなり、また得られ
る超音波プローブにおける振動子の振動による振動子の
割れ、剥がれといった破損を回避し、信頼性の高い超音
波プローブを歩留り良く製造することが可能となる。ま
た、ガラスの組成を変えることで、接合温度を多少変え
ることも可能であり、前述したような理由により、４３
０℃以下の融点を持つガラスを用いることが望ましい。
【００１１】
【実施例】図１は本実施例における超音波プローブの概
略斜視図、図２は本実施例における超音波プローブの縦
断面図、図２は本実施例における超音波プローブのパル
スエコー特性、図３は本実施例における超音波プローブ
に対する熱処理温度プロファイルである。
【００１２】まず、３００℃程度まで電圧性を失わない
チタン酸鉛系セラミックを圧電材料として用い、これを
２０×６４×０．４ｍｍ3 の形状に加工し、両面をカー
ボンランダム＃２０００で研磨し、超音波洗浄すること
で圧電体１を得た。この圧電体１の対向する面に第１層
にＴｉを５０ｎｍ、第２層にＮｉを１０００ｎｍ、第３
層にＣｕを２００ｎｍを順次スパッタし、電極２を形成
し、振動子を得た。
【００１３】まず、３００℃近傍まで圧電性を失わない
チタン酸鉛系圧電材料を用い、これを２０×６４×０．
４ｍｍ3 の形状に加工し、両面をカーボランダム＃２０
００で研磨し、超音波洗浄することで圧電体１を得た。
この圧電体１の両面に第１層にＴｉを５０ｎｍ、第２層
にＮｉを１０００ｎｍ、第３層にＣｕを２００ｎｍ各々
スパッタし、電極２を形成し、振動子を得た。超音波吸
収材４には高温で変質せず、かつ超音波吸収材として使
用可能なチタン酸アルミ系セラミックス（１８×６４×
１０ｍｍ3 ）を用いた。これら振動子と超音波吸収材と
からなる被接合材の接合面にガラス３（日本電気硝子
（株）製低膨脹セラミックス用ガラスＰＬＳ−１３０
１）を５０μｍずつスクリーン印刷し、大気中１２０℃
で２０分乾燥させた。その後、振動子と超音波吸収材を
ガラス面を合わせて接合治具に乗せ、その上に荷重とし
て８００ｇのステンレスブロックを乗せた。これを電気
炉大気中で図３に示したような温度プロファイルで熱処
理し、振動子と超音波吸収材を接合し、プローブを得
た。
【００１４】得られたプローブは、振動子の反り、破損
がなく、また、２２０℃のシリコンオイル中におけるパ
ルスエコー特性を計測したところ、図２に示すように受
信波のレベルが約４波長で１／１０になっており、超音
波吸収材の効果も良好であった。さらに−１９３℃の液
体窒素中におけるパルスエコー特性を計測したところ、
同様に超音波吸収材の効果が良好であった。
【００１５】以下に本発明との比較のために、金属ロウ
によるロウ付けを用いた超音波プローブの製作例を述べ
る。まず、３００℃近傍まで圧電性を失わないチタン酸
鉛系圧電材料を用い、これを２０×６４×０．４ｍｍ3
の形状に加工し、両面をカーボランダム＃２０００で研
磨し、超音波洗浄することで圧電体１を得た。圧電体１
の両面に第１層にＴｉを５０ｎｍ、第２層にＮｉを１０
００ｎｍ、第３層にＣｕを２００ｎｍ各々スパッタし、
電極２を形成し、振動子を得た。超音波吸収材４には高
温で変質せず、かつ超音波吸収材として使用可能なチタ
ン酸アルミ系セラミックス（１８×６４×１０ｍｍ3 ）
を用いた。これら被接合材の接合面にアルミ系ロウ材５
（１８×６４×０．１ｍｍ3 ）を挟み、１００ｇ／ｃｍ
の荷重を外部から印加しながら電気炉大気中で図４に示
すような温度プロファイルで熱処理し、振動子と超音波
吸収材を接合し、超音波プローブを得た。この超音波プ
ローブにパルス電圧を印加したところ、超音波プローブ
は図５に示すように振動子と超音波吸収材の接合部の残
留応力が最大になる部分で振動子に割れが生じた。
【００１６】なお、前記実施例では圧電体としてチタン
酸鉛系セラミックスを例にして説明したが、ニオブ酸鉛
セラミックス、ニオブ酸リチウム単結晶、タンタル酸リ
チウム単結晶等を用いても同様な効果を確認する事が出
来た。
【００１７】
【発明の効果】以上説明したように、本発明によれば低
温から高温まで使用可能で分解能の高い超音波プローブ
を提供出来る。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe used for a pulse echo method, and more particularly, to an ultrasonic probe having a structure having cold and heat resistance which can be used from a low temperature to a high temperature. Related to. 2. Description of the Related Art An ultrasonic probe has a vibrator made of a piezoelectric material for transmitting and receiving ultrasonic waves. An ultrasonic absorbing material for improving the resolution of the probe is usually bonded to the surface of the vibrator opposite to the ultrasonic transmitting / receiving surface. Many conventional probes use an organic adhesive to join the ultrasonic absorber and the vibrator. Therefore, at a low temperature such as the temperature of liquid nitrogen, the adhesive is hardened, the transmittance of ultrasonic waves is reduced, and the adhesive strength is reduced. Further, in a high-temperature environment of 200 ° C. or higher, the adhesive is carbonized, deteriorated, or has a reduced adhesive strength, and cannot be used. Further, as an example of a probe that can be used at a high temperature, a probe using brazing with a metal braze for joining a transducer and an ultrasonic absorber has been reported (ultrasonic TE).
CHNO August 1993, p. 70-71). But,
The brazing with a metal brazing requires a high bonding temperature and a large thermal aberration between the vibrator and the brazing material. For this reason, a large residual stress is generated between the vibrator and the brazing material or between the brazing material and the ultrasonic absorbing material after the joining, which causes a problem that the vibrator is easily warped or damaged. [0003] As described above, the conventional ultrasonic probe has a problem that it cannot be used in a high-temperature environment and is liable to be damaged. The present invention has been made in view of such a problem, and an object of the present invention is to provide an ultrasonic probe having excellent heat resistance and high reliability. [0004] [Means for Solving the Problems and effects of the present invention, pressure
A vibrator composed of a piezoelectric body made of electroceramic or piezoelectric single crystal , and an electrode formed on a surface facing the piezoelectric body ; and a titanate alloy provided on a vibrating surface of the vibrator.
Ultrasonic absorber made of Lumi ceramics and 430 ° C or less for joining the vibrator and ultrasonic absorber
An ultrasonic probe comprising: a glass having a melting point . [0005] That is, glass is used for bonding the vibrator and the ultrasonic absorbing material, and this configuration is suitable for use in an environment of 200 ° C or higher such as a nuclear reactor. The piezoelectric material in the present invention is not particularly limited as long as it is generally used for an ultrasonic probe. For example, piezoelectric ceramics and piezoelectric single crystals can be used. Higher Curie point piezoelectric materials such as lead titanate, lead zirconate titanate, and other lead titanate-based piezoelectric materials, lead ceramics such as lead niobate, and piezoelectric single crystals such as lithium niobate and lithium tantalate It is desirable to use The electrode in the present invention can be used without particular limitation as long as it is a conductor. In addition, a plurality of conductors can be laminated as needed to enhance the adhesion to the piezoelectric body. The ultrasonic absorber according to the present invention improves the resolution of the ultrasonic probe by suppressing residual vibration when ultrasonic waves are generated from the vibrator comprising the piezoelectric body and the electrodes. Therefore, it is formed on the vibration surface of the vibrator and on the side opposite to the ultrasonic transmission / reception. The material used for the ultrasonic absorbing material, considering the use in high temperature, which porous ceramic titanate Aluminum is preferred in view of heat resistance. The glass in the present invention is a bonding material for bonding the vibrator and the ultrasonic absorbing material. As described above, by using glass as a bonding material when bonding the transducer and the ultrasonic absorbing material, it is possible to maintain the bonding strength from a low temperature of about liquid nitrogen temperature to a high temperature exceeding 200 ° C. Become. [0010] The joining temperature is about 30 degrees higher than the melting point of the joining material, the melting point of the glass is generally 500 ° C or less, and lower than the melting point of the brazing material (600 ° C or more).
In addition, since the thermal expansion coefficient is close to that of the piezoelectric body or the ultrasonic absorber as the material to be joined, it is possible to reduce the residual stress on the joining surface caused by the conventional brazing. as a result,
It is possible to manufacture a highly reliable ultrasonic probe with good yield by eliminating warpage of the vibrator in the manufacturing process and avoiding breakage such as cracking and peeling of the vibrator due to vibration of the vibrator in the obtained ultrasonic probe. Become. It is also possible to slightly change the bonding temperature by changing the composition of the glass.
It is desirable to use glass having a melting point of 0 ° C. or less. FIG. 1 is a schematic perspective view of an ultrasonic probe according to the present embodiment, FIG. 2 is a longitudinal sectional view of the ultrasonic probe according to the present embodiment, and FIG. 2 is a pulse echo of the ultrasonic probe according to the present embodiment. FIG. 3 shows a heat treatment temperature profile for the ultrasonic probe in this embodiment. First, a lead titanate-based ceramic which does not lose its voltage characteristics up to about 300 ° C. is used as a piezoelectric material, processed into a shape of 20 × 64 × 0.4 mm 3 , and both surfaces are polished with carbon random # 2000. Then, the piezoelectric body 1 was obtained by ultrasonic cleaning. The first layer is made of 50 nm of Ti, the second layer is made of 1000 nm of Ni,
200 nm of Cu was sequentially sputtered on the layer to form an electrode 2 to obtain a vibrator. First, a lead titanate-based piezoelectric material which does not lose its piezoelectricity up to around 300 ° C. is used, and is made of 20 × 64 × 0.
Processed into 4mm 3 shape, carborundum # 20 on both sides
The resultant was polished at 00 and subjected to ultrasonic cleaning to obtain the piezoelectric body 1.
On both surfaces of the piezoelectric body 1, a first layer of 50 nm was sputtered with Ti, a second layer was sputtered with 1000 nm of Ni, and a third layer was sputtered with 200 nm of Cu, thereby forming an electrode 2 to obtain a vibrator. Aluminum titanate-based ceramics (18 × 64 ×
10 mm 3 ). A glass 3 (a glass PLS-130 for low expansion ceramics manufactured by NEC Corporation) is provided on the bonding surface of the material to be bonded consisting of the vibrator and the ultrasonic absorber.
1) is screen-printed in 50 μm increments at 120 ° C. in air
For 20 minutes. Thereafter, the vibrator and the ultrasonic absorbing material were placed on a joining jig with the glass surfaces aligned, and a 800 g stainless block was placed thereon as a load. This was heat-treated in the atmosphere of an electric furnace with a temperature profile as shown in FIG. 3, and the transducer and the ultrasonic absorber were joined to obtain a probe. The obtained probe was free from warping and breakage of the vibrator, and the pulse echo characteristics in silicon oil at 220 ° C. were measured. As shown in FIG. 2, the level of the received wave was about 4 wavelengths. It was 1/10, and the effect of the ultrasonic absorber was good. Furthermore, when pulse echo characteristics in liquid nitrogen at -193 ° C were measured,
Similarly, the effect of the ultrasonic absorber was good. Hereinafter, for comparison with the present invention, an example of manufacturing an ultrasonic probe using brazing with a metal brazing will be described. First, using a lead titanate-based piezoelectric material without loss of piezoelectric properties up to 300 ° C. vicinity, which 20 × 64 × 0.4mm 3
Then, both surfaces were polished with Carborundum # 2000 and ultrasonically cleaned to obtain a piezoelectric body 1. Piezoelectric body 1
On both sides of the first layer is 50 nm of Ti and the second layer is 10 nm of Ni.
00 nm, Cu was sputtered 200 nm on the third layer,
The electrode 2 was formed, and a vibrator was obtained. Aluminum titanate ceramics (18 × 64 × 10 mm 3 ) which does not deteriorate at high temperatures and can be used as an ultrasonic absorber for the ultrasonic absorber 4
Was used. Aluminum brazing material 5 is applied to the joining surface of these materials to be joined.
(18 × 64 × 0.1 mm 3 ), 100 g / cm
While applying the load from the outside, heat treatment was carried out in the atmosphere of an electric furnace with a temperature profile as shown in FIG. 4 to join the vibrator and the ultrasonic absorber to obtain an ultrasonic probe. When a pulse voltage was applied to the ultrasonic probe, as shown in FIG. 5, the ultrasonic probe cracked in the portion where the residual stress at the joint between the oscillator and the ultrasonic absorbing material was maximized. In the above embodiment, a lead titanate ceramic has been described as an example of the piezoelectric material. I was able to confirm. As described above, according to the present invention, an ultrasonic probe which can be used from a low temperature to a high temperature and has a high resolution can be provided.
【図面の簡単な説明】
【図１】 本発明の超音波プローブの概略斜視図。
【図２】 本発明の超音波プローブの概略断面図。
【図３】 実施例における超音波プローブのパルスエコ
ー特性図。
【図４】 実施例における超音波プローブの熱処理温度
プロファイル。
【図５】 比較例における超音波プローブの熱処理温度
プロファイル。
【図６】 比較例の超音波プローブの概略断面図。
【符号の説明】
１…圧電体
２…スパッタ電極
３…ガラス
４…超音波吸収材
５…ロウ材
６…残留応力最大部
７…破損した振動子BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of an ultrasonic probe according to the present invention. FIG. 2 is a schematic sectional view of an ultrasonic probe according to the present invention. FIG. 3 is a pulse echo characteristic diagram of the ultrasonic probe according to the embodiment. FIG. 4 is a heat treatment temperature profile of an ultrasonic probe in an example. FIG. 5 is a heat treatment temperature profile of an ultrasonic probe in a comparative example. FIG. 6 is a schematic sectional view of an ultrasonic probe of a comparative example. [Explanation of Signs] 1 ... Piezoelectric body 2 ... Sputtering electrode 3 ... Glass 4 ... Ultrasonic absorber 5 ... Brazing material 6 ... Maximum residual stress part 7 ... Damaged vibrator
Claims (1)
る圧電体、およびこの圧電体の対向する面に形成された
電極とからなる振動子と、 この振動子の振動面上に設けられチタン酸アルミ系セラ
ミックスからなる超音波吸収材と、 前記振動子および超音波吸収材を接合するための４３０
℃以下の融点を持つガラスとを具備することを特徴とす
る超音波プローブ。(57) [Claims] (1) A piezoelectric ceramic or a piezoelectric single crystal.
A vibrator comprising a piezoelectric body , and an electrode formed on a surface facing the piezoelectric body ; and an aluminum titanate-based ceramic provided on a vibrating surface of the vibrator.
An ultrasonic absorber made of a mix, and 430 for joining the vibrator and the ultrasonic absorber
An ultrasonic probe comprising: a glass having a melting point of not more than ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02895395A JP3378396B2 (en) | 1995-02-17 | 1995-02-17 | Ultrasonic probe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02895395A JP3378396B2 (en) | 1995-02-17 | 1995-02-17 | Ultrasonic probe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08223696A JPH08223696A (en) | 1996-08-30 |
| JP3378396B2 true JP3378396B2 (en) | 2003-02-17 |
Family
ID=12262788
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02895395A Expired - Lifetime JP3378396B2 (en) | 1995-02-17 | 1995-02-17 | Ultrasonic probe |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3378396B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5406881B2 (en) | 2011-05-19 | 2014-02-05 | 日立Ｇｅニュークリア・エナジー株式会社 | Heat-resistant ultrasonic sensor and installation method thereof |
| CN110972046A (en) * | 2019-12-31 | 2020-04-07 | 歌尔股份有限公司 | Dustproof structure, microphone packaging structure and electronic equipment |
| CN114887863B (en) * | 2022-05-19 | 2023-07-25 | 合肥曦合超导科技有限公司 | Ultrasonic probe and preparation method thereof |
-
1995
- 1995-02-17 JP JP02895395A patent/JP3378396B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08223696A (en) | 1996-08-30 |
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