JPH03146837A - Pressure detector - Google Patents

Pressure detector

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Publication number
JPH03146837A
JPH03146837A JP28612989A JP28612989A JPH03146837A JP H03146837 A JPH03146837 A JP H03146837A JP 28612989 A JP28612989 A JP 28612989A JP 28612989 A JP28612989 A JP 28612989A JP H03146837 A JPH03146837 A JP H03146837A
Authority
JP
Japan
Prior art keywords
thin film
pressure
magnetic field
ferromagnetic thin
area
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
Application number
JP28612989A
Other languages
Japanese (ja)
Inventor
Katsuto Nagano
克人 長野
Takashi Sato
隆 佐藤
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.)
TDK Corp
Original Assignee
TDK Corp
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 TDK Corp filed Critical TDK Corp
Priority to JP28612989A priority Critical patent/JPH03146837A/en
Publication of JPH03146837A publication Critical patent/JPH03146837A/en
Pending legal-status Critical Current

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  • Measuring Fluid Pressure (AREA)

Abstract

PURPOSE:To uniformalize a magnetic domain comprising a ferromagnetic thin film and to improve detecting accuracy in the detection of pressure by providing a bias magnet to apply a magnetic field in a perpendicular direction to a plane on which the ferromagnetic thin film is provided. CONSTITUTION:A detecting part is set on a flat plane 2b at a side opposite to the recessed part 2a of a substrate 2 made of glass with a recessed cross-section by forming the ferromagnetic thin film 3 made of NiCo, etc., in a prescribed pattern by a photo- etching method. A protective part 4 made of, for example, silicon nitride is provided on the thin film 3, and furthermore, electrode parts 5 made of, for example, gold are provided at both end parts of the thin film 3. Also, the bias magnet 8 to apply the bias magnetic field to the thin film 3 is provided at a recessed part 2a side, and filming with a synthetic resin member 9 is performed so as to include the magnet 8 except for the pressure detecting area 4a of the protective part 4 corresponding to the detecting part of the thin film 3 and the external connection terminal 7a of a lead terminal 7. Thereby, the magnetic domain comprising the thin film 3 can be uniformalized, and a rate of change of resistance shows the same curve when magnetic field strength is changed from a negative area to a positive area and when it is changed from the positive area to the negative area, which eliminates dispersion in the characteristic.

Description

【発明の詳細な説明】 [発明の目的] (産業上の利用分野) 本発明は、圧力検知装置に関し、さらに詳しくは強磁性
体薄膜の圧力による磁気抵抗変化を利用した圧力検知装
置の改良に関する。
[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a pressure sensing device, and more particularly to an improvement in a pressure sensing device that utilizes changes in magnetic resistance caused by pressure in a ferromagnetic thin film. .

(従来の技術) 強磁性薄膜を基板上に所定のパターンで形成し、強磁性
体薄膜に外部圧力が作用するときこの部分の磁気抵抗が
変化することを利用して圧力の変位検出を行う圧力検知
装置として従来第7図に示すものが知られている。
(Prior art) A pressure method in which a ferromagnetic thin film is formed in a predetermined pattern on a substrate, and pressure displacement is detected by utilizing the change in magnetic resistance of this part when external pressure acts on the ferromagnetic thin film. As a conventional detection device, one shown in FIG. 7 is known.

同図に示す圧力検知装置21は、断面凹状のガラス製の
基板22と、前記基板22の凹部22aとは反対側の平
坦面22b上にフォトエツチング方法によりNiCo等
の磁気抵抗効果を発揮する強磁性体薄膜23を所定のパ
ターンに形成して検知部とし、前記強磁性体薄膜23上
に例えば窒化ケイ素からなる保護部24を設け、さらに
前記強磁性体薄膜23の両端部には例えば金などにより
電極部25を設け、前記電極部25に同様に金などによ
りリード線26を接続配置し、前記リード線26の一端
部を例えば銅製のリード端子27に接続配置して成り、
かつ、前記強磁性体薄膜23の検知部に対応する前記保
護部24の圧力検知領域24aと、前記リード端子27
の外部接続端27aを除いた装置外周のほぼ全域を合成
樹脂部材28により被覆して構成されている。
The pressure sensing device 21 shown in the figure includes a glass substrate 22 with a concave cross section, and a strong material such as NiCo that exhibits a magnetoresistive effect by photo-etching on a flat surface 22b on the opposite side of the concave portion 22a of the substrate 22. A magnetic thin film 23 is formed in a predetermined pattern to serve as a detection part, a protective part 24 made of silicon nitride, for example, is provided on the ferromagnetic thin film 23, and further, a protective part 24 made of, for example, silicon nitride is provided on both ends of the ferromagnetic thin film 23. An electrode part 25 is provided, a lead wire 26 is similarly connected to the electrode part 25 using gold or the like, and one end of the lead wire 26 is connected to a lead terminal 27 made of copper, for example.
and the pressure detection area 24a of the protection part 24 corresponding to the detection part of the ferromagnetic thin film 23 and the lead terminal 27.
Almost the entire outer periphery of the device excluding the external connection end 27a is covered with a synthetic resin member 28.

そして、前記圧力検知装置21は、圧力付与部材29に
より所定の印加圧力を、前記圧力検知領域24aに付与
されたときその圧力Pの検出を行うようになっている。
The pressure detection device 21 detects the pressure P when a predetermined pressure is applied to the pressure detection region 24a by the pressure application member 29.

ところで前記圧力検知装置21の磁界強度−抵抗変化率
特性は、第8図に示すように、電源31によりコイル3
0に電圧を印加して磁束φを圧力検知装置21にかけ、
上述した圧力検知装置21の印加圧力による磁界強度−
抵抗変化率特性によって測定される。
By the way, the magnetic field strength-resistance change rate characteristic of the pressure sensing device 21 is as shown in FIG.
Apply a voltage to 0 to apply magnetic flux φ to the pressure detection device 21,
Magnetic field strength due to the pressure applied by the pressure detection device 21 described above -
Measured by resistance change rate characteristics.

この場合、理論上は第9図に示すように(X軸に磁界強
度(Gニガウス)を、y軸に抵抗変化率を示す)、例え
ば印加圧力(図中Pとも表示する)をOkg/aif、
  0.5kg/ad、  1聴/dのように変化させ
ていくと、磁界強度に対する抵抗変化率が各々略余弦関
数の2乗に応じて変化する特性を示し、磁界強度が正負
両側の飽和磁界(磁界強度を変化させても抵抗変化が生
じない領域)に至ると抵抗変化率は飽和状態になる各特
性曲線が得られる。
In this case, theoretically, as shown in Fig. 9 (the X-axis shows the magnetic field strength (G n Gauss) and the y-axis shows the resistance change rate), for example, the applied pressure (also indicated as P in the figure) is Okg/aif. ,
When the magnetic field strength is changed to 0.5 kg/ad or 1 audio/d, the rate of change in resistance with respect to the magnetic field strength changes approximately according to the square of the cosine function, and the magnetic field strength becomes the saturated magnetic field on both the positive and negative sides. (A region in which no change in resistance occurs even when the magnetic field strength is changed) is reached, resulting in each characteristic curve in which the rate of change in resistance becomes saturated.

(発明が解決しようとする課題) しかしながら、実際には前記強磁性体薄膜23のセンサ
を構成する磁区の不均一さに基因して、第10図に示す
ように(印加圧力0.5kg/dの場合を例にする)、
磁界強度を負の領域(図中符号−で示す領域)から正の
領域(図中符号子で示す領域)に変化させた場合の抵抗
変化率を示す曲線β、と、正の領域から負の領域に変化
させた場合の抵抗変化率を示す曲線12とが一致せず、
前記強磁性体薄膜23に同じ圧力を印加しても異なる抵
抗値を示すことが分かる(第10図中y軸上に2つの交
点a、  bが存在するため)。
(Problem to be Solved by the Invention) However, in reality, due to the non-uniformity of the magnetic domains constituting the sensor of the ferromagnetic thin film 23, as shown in FIG. ),
The curve β shows the rate of change in resistance when the magnetic field strength is changed from a negative region (the region indicated by the symbol - in the figure) to a positive region (the region indicated by the symbol in the figure), and The curve 12 showing the rate of change in resistance when changing the area does not match,
It can be seen that even if the same pressure is applied to the ferromagnetic thin film 23, it exhibits different resistance values (because there are two intersections a and b on the y-axis in FIG. 10).

この結果製品化した場合、圧力検知装置21の圧力検知
に大きな誤差を生じるという問題を招く。
As a result, if it is commercialized, a problem arises in that a large error occurs in pressure detection by the pressure detection device 21.

本発明は上記事情に鑑みてなされたものであり、強磁性
体薄膜を構成する磁区の均一化が図れ、圧力検知の検知
精度の向上が図れる圧力検知装置を提供することを目的
とするものである。
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a pressure detection device that can uniformize the magnetic domains constituting a ferromagnetic thin film and improve the detection accuracy of pressure detection. be.

[発明の構成コ (課題を解決するための手段) 本発明の構成は基板上に強磁性体薄膜を設け、外部圧力
の作用下で生じる前記強磁性体薄膜の磁気抵抗の変化を
利用して圧力検知を行う圧力検知装置であって、前記強
磁性体薄膜を設けた面に対し垂直方向の磁界を印加する
バイアス磁石を備えたことを特徴とするものである。
[Configuration of the Invention (Means for Solving the Problems) The configuration of the present invention is to provide a ferromagnetic thin film on a substrate, and utilize the change in magnetic resistance of the ferromagnetic thin film that occurs under the action of external pressure. This pressure sensing device detects pressure, and is characterized by comprising a bias magnet that applies a magnetic field perpendicular to the surface on which the ferromagnetic thin film is provided.

(作 用) 上記構成の装置によれば、強磁性体薄膜に対し上述のよ
うなバイアス磁石を設けたことにより、強磁性体薄膜を
構成する磁区の均一化が図れ、磁界強度−抵抗変化率特
性のばらつきが無くなる。
(Function) According to the device having the above configuration, by providing the bias magnet as described above to the ferromagnetic thin film, the magnetic domains constituting the ferromagnetic thin film can be made uniform, and the magnetic field strength - resistance change rate Dispersion in characteristics is eliminated.

(実施例) 以下本発明の一実施例を図面を参照して説明する。(Example) An embodiment of the present invention will be described below with reference to the drawings.

第1図は本発明の一実施例装置を示す概略断面図である
FIG. 1 is a schematic sectional view showing an apparatus according to an embodiment of the present invention.

同図に示す圧力検知装置1は、断面凹状のガラス製の基
板2を備え、この基板2の凹部2aとは反対側の平坦面
2b上にフォトエツチング方法によりNiCo等の磁気
抵抗効果を発揮する強磁性体薄膜3を所定のパターンに
形成して検知部とし、前記強磁性体薄膜3上に例えば窒
化ケイ素からなる保護部4を設け、さらに前記強磁性体
薄膜3の両端部には例えば金などにより電極部5を設け
、前記電極部5に同様に金などによりリード線6を接続
配置し、前記リード線6の一端部を例えば銅製のリード
端子7に接続配置し、前記凹部2a側に、前記強磁性体
薄膜3にバイアス磁界を印加するバイアス磁石8を設け
て成り、かつ、前記強磁性体薄膜3の検知部に対応する
前記保護部4の圧力検知領域4aと、前記リード端子7
の外部接続端7aを除き、さらに前記バイアス磁石8を
内包し、装置外周のほぼ全域を合成樹脂部材9により被
覆して構成されている。また図中30は印加圧力による
たわみを逃げるための空間部である。
The pressure sensing device 1 shown in the figure is equipped with a glass substrate 2 having a concave cross section, and a magnetoresistive effect of NiCo or the like is formed on a flat surface 2b of the substrate 2 on the opposite side from the concave portion 2a by a photoetching method. A ferromagnetic thin film 3 is formed in a predetermined pattern to serve as a detection part, a protective part 4 made of silicon nitride, for example, is provided on the ferromagnetic thin film 3, and further, a protective part 4 made of, for example, silicon nitride is provided on both ends of the ferromagnetic thin film 3. An electrode portion 5 is provided by a method such as the above, a lead wire 6 is similarly connected to the electrode portion 5 using gold or the like, one end of the lead wire 6 is connected to a lead terminal 7 made of copper, for example, and the lead wire 6 is connected to the electrode portion 5, and one end of the lead wire 6 is connected to a lead terminal 7 made of copper, for example. , a bias magnet 8 for applying a bias magnetic field to the ferromagnetic thin film 3 is provided, and the pressure sensing area 4a of the protection part 4 corresponding to the sensing part of the ferromagnetic thin film 3 and the lead terminal 7 are provided.
Except for the external connection end 7a, the bias magnet 8 is further enclosed, and almost the entire outer periphery of the device is covered with a synthetic resin member 9. Further, numeral 30 in the figure is a space portion for escaping deflection due to applied pressure.

尚、前記バイアス磁石8のバイアス磁界の強度は、飽和
磁界(第9図参照)より小さく、かつ、前記強磁性体薄
膜3を設けた面に対し垂直方向の磁界を印加するように
設定するのが良好である。
The strength of the bias magnetic field of the bias magnet 8 is set to be smaller than the saturation magnetic field (see FIG. 9) and to apply a magnetic field perpendicular to the surface on which the ferromagnetic thin film 3 is provided. is good.

そして、前記圧力検知装置Iは、圧力付与部材10によ
り所定の印加圧力を付与され圧力Pの検知を行なうよう
に戊っている。
The pressure sensing device I is configured to detect a pressure P by applying a predetermined applied pressure by a pressure applying member 10.

次に上述した圧力検知装置1の特性について図面を参照
して説明する。
Next, the characteristics of the pressure sensing device 1 described above will be explained with reference to the drawings.

前述した従来例と同様に、前記圧力検知装置1の特性は
、第2図に示すように、電源12によりコイル11に電
圧を印加して磁束φを圧力検知装置1にかけ、上述した
圧力検知装置1の印加圧力による、磁界強度−抵抗変化
率特性によって測定される。
Similar to the conventional example described above, the characteristics of the pressure sensing device 1 are as shown in FIG. It is measured by the magnetic field strength-resistance change rate characteristic with an applied pressure of 1.

圧力検知装置1に所定の印加圧力(図中Pとも表示する
)を与えた場合、第3図(X軸に磁界強度(Gニガウス
)を、y軸に抵抗変化率を示す)に示すように印加圧力
をOkg/ad、  0. 5kg/ai。
When a predetermined applied pressure (also indicated as P in the figure) is applied to the pressure detection device 1, as shown in Fig. 3 (the X-axis shows the magnetic field strength (G n Gauss) and the y-axis shows the resistance change rate), The applied pressure is Okg/ad, 0. 5kg/ai.

1 kg/alのように変化させていくと、前述した第
9図に示す理論上の各特性曲線とほぼ同一の各特性曲線
が得られる。そして、磁界強度に対する抵抗変化率が各
々略余弦関数の2乗に応じて変化する特性を示し、磁界
強度が正負両側の飽和磁界(磁界強度を変化させても抵
抗変化が生じない領域)に至ると抵抗変化率は飽和状態
になる。
When the pressure is varied by 1 kg/al, characteristic curves that are almost the same as the theoretical characteristic curves shown in FIG. 9 described above are obtained. The rate of change in resistance with respect to magnetic field strength changes approximately according to the square of the cosine function, and the magnetic field strength reaches a saturation magnetic field on both the positive and negative sides (a region where no change in resistance occurs even if the magnetic field strength is changed). and the resistance change rate becomes saturated.

この結果、例えば圧力0. 5kg/alの場合、従来
例と異なり、第4図に示すように磁界強度を、負の領域
(図中符号−で示す領域)から正の領域(図中符号子で
示す領域)に変化させた場合と正の領域から負の領域に
変化させた場合との抵抗変化率を示す曲線は、同一の曲
線となる。これは前記強磁性体薄膜3を構成する磁区が
均一化されたことに起因するものである。
As a result, for example, the pressure is 0. In the case of 5 kg/al, unlike the conventional example, the magnetic field strength is changed from a negative region (region indicated by a symbol - in the figure) to a positive region (region indicated by a symbol in the figure) as shown in Fig. 4. The curves showing the rate of change in resistance when changing from the positive region to the negative region are the same curves. This is due to the fact that the magnetic domains constituting the ferromagnetic thin film 3 are made uniform.

したがって、第3図中それぞれの印加圧力に対する特性
曲線とy軸との交点c、  d、  eに対応する抵抗
値(図中は抵抗変化率で示している)により、前記圧力
検知装置1の出力の基準値を設定すことができる。
Therefore, the output of the pressure sensing device 1 is determined by the resistance values (indicated by resistance change rate in the figure) corresponding to the intersection points c, d, and e of the characteristic curves for each applied pressure and the y-axis in FIG. It is possible to set a reference value for

このようにして、第■図に示す構成の圧力検知装置1を
例えば第5図に示すように、外部固定抵抗Rに直接接続
をし、電圧V。を印加し、前記圧力検知装置lの出力電
圧を増幅回路13にて増幅して検知すれば、精度よく圧
力検知ができる。
In this way, the pressure sensing device 1 having the configuration shown in FIG. 2 is directly connected to an external fixed resistor R as shown in FIG. , and the output voltage of the pressure sensing device 1 is amplified and detected by the amplifier circuit 13, pressure can be detected with high accuracy.

本発明は、上述した実施例に限定されるものではなく、
その要旨の範囲内で種々の変形が可能である。
The present invention is not limited to the embodiments described above,
Various modifications are possible within the scope of the gist.

例えば強磁性体薄膜(検知部)のパターン及び圧力検知
装置自体の構成も適宜変更可能であり、第6図に示すよ
うに互いに直交する方向に形成されたパターン14a、
14bと、パターン15a。
For example, the pattern of the ferromagnetic thin film (sensing section) and the configuration of the pressure sensing device itself can be changed as appropriate, and as shown in FIG. 6, patterns 14a formed in mutually orthogonal directions,
14b and pattern 15a.

15bとを有し、これらをブリッジ接続した構成として
もよい。
15b, and these may be bridge-connected.

また同図に示すようにパターン14 a、 15 aを
前記圧力付与部材10等により圧力が付与され、圧力を
検知する圧力検知領域16に対応するように配置し、さ
らに同図に示すような回路構成とすれば、図中の出力端
子b工eb2間の出力の増大が図れるため検知感度の向
上を図れる。尚図中17は印加電源であり、18は接地
部(アース)であり、Roは抵抗である。
Further, as shown in the figure, the patterns 14a and 15a are arranged so as to correspond to the pressure detection area 16 where pressure is applied by the pressure applying member 10 etc. and the pressure is detected, and furthermore, a circuit as shown in the figure is arranged. With this configuration, it is possible to increase the output between the output terminals b and eb2 in the figure, thereby improving the detection sensitivity. In the figure, 17 is an applied power source, 18 is a grounding part (earth), and Ro is a resistance.

[発明の効果コ 以上詳述した本発明によれば、強磁性体薄膜のセンサを
構成する磁区の均一化が図れ、圧力検知の検出精度の向
上が可能な圧力検知装置を提供することができる。
[Effects of the Invention] According to the present invention described in detail above, it is possible to provide a pressure detection device in which the magnetic domains constituting the ferromagnetic thin film sensor can be made uniform and the detection accuracy of pressure detection can be improved. .

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の一実施例装置を示す概略断面図、第2
図は本発明の一実施例装置の特性測定方法の説明図、第
3図及び第4図ははそれぞれ本発明の実施例装置の特性
説明図、第5図は本発明の実施例装置の使用状態の概略
回路図、第6図は本発明の変形例の概略構成図、第7図
は従来例を示す概略断面図、第8図は従来例の特性測定
方法の説明図、第9図及び第10図はそれぞれ従来例の
特性説明図である。 1・・・圧力検知装置、 2・・・基板、3・・・強磁
性体薄膜、 4・・・保護膜、5・・・電極部、 6・
・・リード線、7・・・リード端子、 8・・・バイア
ス磁石。
FIG. 1 is a schematic sectional view showing an embodiment of the device of the present invention, and FIG.
The figure is an explanatory diagram of the characteristic measuring method of the apparatus according to the embodiment of the present invention, FIGS. 3 and 4 are explanatory diagrams of the characteristics of the apparatus according to the embodiment of the present invention, and FIG. 6 is a schematic configuration diagram of a modified example of the present invention, FIG. 7 is a schematic sectional view showing a conventional example, FIG. 8 is an explanatory diagram of a characteristic measuring method of the conventional example, and FIG. FIG. 10 is a characteristic diagram of each conventional example. DESCRIPTION OF SYMBOLS 1... Pressure detection device, 2... Substrate, 3... Ferromagnetic thin film, 4... Protective film, 5... Electrode part, 6...
...Lead wire, 7...Lead terminal, 8...Bias magnet.

Claims (1)

【特許請求の範囲】[Claims] 基板上に強磁性体薄膜を設け、外部圧力の作用下で生じ
る前記強磁性体薄膜の磁気抵抗の変化を利用して圧力検
知を行う圧力検知装置であって、前記強磁性体薄膜を設
けた面に対し垂直方向の磁界を印加するバイアス磁石を
備えたことを特徴とする圧力検知装置。
A pressure sensing device that includes a ferromagnetic thin film provided on a substrate and detects pressure by utilizing a change in magnetic resistance of the ferromagnetic thin film that occurs under the action of external pressure, wherein the ferromagnetic thin film is provided. A pressure sensing device characterized by being equipped with a bias magnet that applies a magnetic field in a direction perpendicular to a surface.
JP28612989A 1989-11-02 1989-11-02 Pressure detector Pending JPH03146837A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP28612989A JPH03146837A (en) 1989-11-02 1989-11-02 Pressure detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP28612989A JPH03146837A (en) 1989-11-02 1989-11-02 Pressure detector

Publications (1)

Publication Number Publication Date
JPH03146837A true JPH03146837A (en) 1991-06-21

Family

ID=17700306

Family Applications (1)

Application Number Title Priority Date Filing Date
JP28612989A Pending JPH03146837A (en) 1989-11-02 1989-11-02 Pressure detector

Country Status (1)

Country Link
JP (1) JPH03146837A (en)

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