JPH0521861A - Magnetic resistance converting element - Google Patents

Abstract

PURPOSE:To prevent generation of noise caused by unwanted magnetic resistance converting effect at a terminal lead out part of a magnetic resistance converting element. CONSTITUTION:Sensor parts MR1-MR6 consisting of a common magnetoresistance effect thin film and a terminal lead out parts 52 extruding from them constitute a magnetic resistance converting element 21, and the terminal lead out part 52 is provided with a slit 53.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive conversion element, for example, a magnetoresistive effect (M) for detecting a magnetic field from a magnetic scale in a minute position detecting device such as a magnetic scale device.
R) The present invention relates to a magnetoresistive conversion element composed of a thin film.

[0002]

2. Description of the Related Art For example, a change in an external magnetic field due to a relative displacement with respect to a constant repetitive magnetization pattern of a magnetic scale or the like is converted into an electric signal to detect a minute position thereof, and further, a length measurement, a moving amount, a moving speed and a rotation are obtained. There is a device using a magnetoresistive conversion element made of an MR thin film as a detection element in a minute position detection device for detecting a speed and the like.

FIG. 3 shows an arrangement configuration diagram of the minute position detection position. Reference numeral 11 denotes a magnetic scale that provides an external magnetic field for minute position detection in which NS magnetization patterns are repeatedly arranged with a pitch λ, and the magnetoresistive conversion element 21 has a magnetic scale in the direction of arrangement of the repeated NS magnetization patterns of the magnetic scale 11. It is adapted to move relative to 11 facing.

As shown in the circuit configuration of FIG. 4, the magnetoresistive conversion element 21 includes a pair of MR thin films formed between a power source (Vcc) terminal 1 and ground terminals 2G ₁ and 2G ₂ , that is, a magnetic sensor. Sections MR ₁ and MR ₂ , MR ₃ and MR ₄ , MR ₅ and MR ₆ are connected, and output terminals 12, 34 and 5 are output from the connection midpoints of the sensor sections of each pair.
6 is derived. In addition, a configuration is adopted in which resistors R _S1 and R _S2 connected in series for extracting a reference output are connected in parallel with the sensor unit by the series connection of these pairs, and the reference voltage extraction terminal S ₁₂ is derived from the midpoint of the connection. Be done.

As shown in FIG. 3, each of the sensor portions MR _{1 to} MR ₆ has a thin linear pattern extending in the Y direction orthogonal to the arrangement direction X of the magnetization pattern of the magnetic scale 11 and has a zigzag pattern. The pair of zigzag patterns are arrayed and formed at a pitch corresponding to the magnetization pitch λ of the magnetic scale 11, and the sensor unit MR is provided.
₁ and MR ₂ , MR ₃ and MR ₄ , MR ₅ and M
R ₆ and R ₆ are arranged so as to each be an integral multiple of λ / 2 of the magnetization pitch λ of the magnetic scale 11.

Further, each pair of sensor units MR₁And MR₂
Output terminal 12, MR₃And MR _FourOutput terminal 3 between
4, MR_FiveAnd MR₆Output terminal 56 between, reference resistance R_S1
And R _S2Terminal S between₁₂And the power supply Vcc terminal 1 are respectively
With a sufficiently large width, the above-mentioned magnetization pattern arrangement direction
It is formed so as to extend in the Y direction orthogonal to X.

These terminals ₁₂ , 34, 56, S ₁₂ ,
In order to reduce the number of manufacturing steps and to increase the density and accuracy of the entire pattern, 1 is the same as the sensor units MR _{1 to} MR ₆ made of MR thin film and the reference output extracting resistors R _S1 and R _S2 . It is formed by the terminal lead-out portion 52 formed of a magnetoresistive thin film. That is, for example, NiFe
Alternatively, the sensor parts MR _{1 to} MR ₆ , the resistances R _S1 ,
It is formed at the same time as R _S2 .

According to the magnetoresistive conversion element having such a configuration, the external magnetic field applied from the magnetic scale 11 causes the output terminals 12, 34, 56 to output λ / 3, respectively.
The output corresponding to the position of 2λ / 3 is taken out, and A, B, C, ..., A, b, c in FIG.
The position information is taken out by the output of the intersection of.

However, in the case of the above-mentioned configuration,
Repeat these intersections A, B, C, ..., a, b, c ...
The position information may be inaccurate due to the displacement at the intersection.
It This is, for example, schematically shown in FIG.
As shown by the arrow, the magnetic flux from NS magnetization
Each terminal part, for example, the ground terminal part 2
G ₁, 2G₂, The electric field is applied to the power supply terminal 1 etc.
This is because the resistance changes. That is, see FIG.
As is clear from the above, one example is the sensor unit MR.
₁And MR₂For power supply terminal 1 and ground terminal 2G₁,
Between these terminals 1 and 2G ₁In the terminal derivation unit 52 of
The resistance change due to this magnetic field is inserted in series.
Becomes

And, it is practically almost impossible to arrange them in the same phase in order to avoid the influence of the magnetoresistive conversion in the terminal lead-out portion 52 on each MR, that is, the sensor portion, due to the restriction from the arrangement configuration of the entire pattern. .. Therefore, the output waveform described with reference to FIG. 5 is distorted by the magnetoresistive conversion by each terminal deriving unit 52, and this causes the intersections A, B, C, ..., A, b, c.
A position shift occurs in ..., which hinders accurate minute position detection.

In addition, since the pattern of each terminal lead-out portion 52 is actually formed wider than that of each sensor portion, it is necessary to make the resistance value smaller, so that each terminal lead-out portion 5 is formed.
The width of the pattern 2 becomes closer to the NS magnetizing pitch λ of the magnetic scale 11, and as can be seen from FIG. 6, the magnetic flux from the NS magnetizing of the magnetic scale is effective for each terminal lead portion. Since it is introduced into 52, the influence of the above-mentioned deviation of the position detection becomes large.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a magnetoresistive conversion element in which a sensor section and a terminal lead-out section from the sensor section are formed by a common MR thin film as described above. The influence of the magnetoresistive conversion effect is reduced so that, for example, minute position detection can be accurately performed.

[0013]

In the present invention, as shown in FIG.
As shown in the layout diagram of an example when applied to the minute position detecting device of that example, the sensor unit MR and the terminal lead-out unit 52 from the sensor unit MR are configured by the common magnetoresistive thin film, that is, the MR thin film 51. Magnetoresistive conversion element 21
In, the slit 53 is provided in the terminal lead-out portion 52.

Actually, the slit 53 is formed so as to extend along the energization direction to the slit 53 and extend in the direction transverse to the direction of the magnetic flux from the magnetic scale 11 as shown in FIG.

[0015]

According to the above-described structure of the present invention, the introduction of the external magnetic field is effectively avoided by providing the slit 53 in the terminal lead-out portion 52, and the energization of the external magnetic field is controlled in the extension direction of the slit 53. If provided along the energizing direction, the terminal lead-out portion 5 by providing this slit 53
It is possible to effectively avoid the increase in resistance of No. 2.

As described above, according to the configuration of the present invention, the position information output can be accurately obtained in the case of being applied to the above-mentioned minute position detecting device or the like by effectively avoiding the influence of the external magnetic field in the terminal lead-out portion 52. You can

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, the magnetoresistive conversion element according to the present invention can adopt the structure of, for example, the sensor portions MR _{1 to} MR ₆ as described in FIGS. 3 and 4.
The pattern and the configuration can be the same as those described with reference to FIG. 3, and the portions in FIG. 1 corresponding to those in FIG.

That is, also in the present invention, as shown in the circuit configuration of FIG. 4, a sensor portion, ie, a magnetic sensitive portion MR, which is composed of a pair of MR thin films, is provided between the power supply (Vcc) terminal 1 and the ground terminals 2G ₁ and 2G _{2. 1} and MR ₂ , MR ₃ and MR ₄ , MR ₅ and MR ₆ are connected, and the output terminals 12, 34 and 56 are respectively output from the connection midpoints of the sensor units of each pair.
Is derived. In addition, a resistor R connected in series for extracting a reference output in parallel with the sensor unit by connecting these pairs in series.
A configuration is adopted in which _S1 and R _S2 are connected and the reference voltage output terminal S ₁₂ is derived from the midpoint of the connection.

In each of the sensor units MR _{1 to} MR ₆ , for example, a thin linear pattern extending in the Y direction orthogonal to the arrangement direction X of the magnetization pattern of the magnetic scale 11 has a zigzag pattern, and each pair of zigzag patterns has a magnetic scale. The magnetic scale 11 is magnetized by the sensor portions MR ₁ and MR ₂ , MR ₃ and MR ₄ , MR ₅ and MR _6, which are arranged and arranged at a pitch corresponding to the magnetizing pitch λ of 11. It is arranged so as to be an integral multiple of λ / 2 of the pitch λ.

Further, each pair of sensor units MR₁And MR₂
Output terminal 12, MR₃And MR _FourOutput terminal 3 between
4, MR_FiveAnd MR₆Output terminal 56 between, reference resistance R_S1
And R _S2Terminal S between₁₂, And Vcc terminal 1 are
With a width that is larger than that of the above-mentioned magnetizing pattern array direction X
It is formed so as to extend in the orthogonal Y direction.

And, these terminals 12, 34, 5
6, S ₁₂ , 1 are the sensor parts MR _{1 to} MR ₆ made of an MR thin film and the reference output extracting resistor R _{S1 in} order to reduce the number of manufacturing steps, increase the density of the entire pattern, and improve the accuracy. And R _S2 together with the terminal lead-out portion 52 formed of the same magnetoresistive thin film. That is, the sensor parts MR _{1 to} MR are formed by vapor deposition of an MR thin film such as NiFe or NiCo on the whole surface, film formation such as sputtering, and then selective etching by photolithography.
₆ , the resistors R _S1 , R _S2, etc. are formed at the same time.

In particular, in the present invention, the above-mentioned MR thin film is patterned by photolithography to form each sensor portion MR _{1 to} MR ₆ and each terminal lead portion 52.
Further, when forming the resistors R _S1 and R _S2 , the MR derivation portion 5 thereof is formed.
The slit 53 is formed in 2.

The slits 53 extend along the main current path in the terminal lead-out portion 52, and the slits 53 are formed intermittently or continuously in the extension direction, and the direction of introduction of the magnetic flux with respect to the external magnetic field. Against slit 5
3 is arranged and formed so as to cross.

Since the slit 53 is provided in this manner, the magnetic resistance of the terminal lead-out portion 52 to the external magnetic flux from the magnetic scale 11 and the like becomes large, so that the terminal lead-out portion 52 is connected to the terminal lead-out portion 52 as schematically shown in FIG. The introduction of magnetic flux is reduced, and the resistance change in the terminal lead-out portion 52 is also small.

In the above example, each terminal lead-out portion 52 is formed along the thin linear pattern of each sensor portion MR in the Y direction orthogonal to the arrangement direction X of the repeated NS magnetization pattern of the magnetic scale 11. However, the present invention can be applied to the case where various derivation patterns are adopted, such as the case where the lead-out portion takes a pattern bent in the direction inclined with respect to the Y direction.

Further, in the above-mentioned example, the present invention is applied to the magnetoresistive conversion element 21 which gives the external magnetic field by the magnetic scale, but the present invention is applied to the magnetoresistive conversion element by various other external magnetic field applying means. Can be applied.

[0027]

As described above, according to the configuration of the present invention, the effect of the external magnetic field in the terminal lead-out portion 52 can be effectively avoided, so that the position detection output can be accurately measured when applied to the above-mentioned minute position detecting device or the like. Obtainable.

[Brief description of drawings]

FIG. 1 is a schematic line layout view of an example of a minute position detecting device to which an example of a magnetoresistive conversion element according to the present invention is applied.

FIG. 2 is a diagram showing a relationship between a terminal lead-out portion, a slit, and an external magnetic field according to the present invention.

FIG. 3 is a schematic configuration diagram of a minute position detecting device using a conventional magnetoresistive conversion element.

FIG. 4 is a circuit diagram of an example of a magnetoresistive conversion element.

FIG. 5 is a waveform diagram of its output.

FIG. 6 is a diagram showing a relationship between the terminal lead-out portion and an external magnetic field.

[Explanation of symbols]

MR ₁ sensor part MR ₂ sensor part MR ₃ sensor part MR ₄ sensor part MR ₅ sensor part MR ₆ sensor part 51 MR thin film 52 terminal lead-out part 53 slit part 11 magnetic scale

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoharu Yamada 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (1)

Claim: What is claimed is: 1. A magnetoresistive conversion element comprising a sensor section and a terminal lead-out section formed from the same magnetoresistive thin film, wherein a slit is provided in the terminal lead-out section. A magnetoresistive conversion element characterized by.