JPH06221869A - Mr sensor device - Google Patents

Abstract

PURPOSE:To provide a magnetoresistance effect (MR) sensor device that provides stable detection signal, by providing a heat-exchange film that covers, from above a protective film, nearly entire surface of a detection part and has nearly same conductive material as signal line. CONSTITUTION:A protective film 15 covers nearly entire surface of an MR sensor part 2. A heat-exchange film 10 covers nearly entire surface of a detection part 9, and contains the conductive material of nearly same quality as a signal line (conductive pattern) 12. A coating film (base film) 11 covers at least one end part of the signal line 12, the protective film 15, and nearly entire surface of the MR sensor part 2, from above the heat-exchange film 10. With the heat-exchange film 10 provided, when the detection part 9 is energized for heating, the heat is exchanged within the heat-exchange film 10, so temperature distribution on the surface of the detection part 9 becomes even, thus stable signal is obtained. Since the total thickness of the protective film 15 and heat-exchange film 10 equals to that of the signal line 12, the surface of coating film 11 becomes linear, and the detection surface of the sensor part 2 becomes parallel to that of the coating film 11, so, positional adjustment of the sensor part 2 becomes easier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an MR sensor (magnetoresistive effect sensor) device suitable for use in a position detecting device such as a machine tool.

[0002]

2. Description of the Related Art Conventionally, an MR sensor device, which is arranged facing a magnetic recording medium magnetized at equal intervals and provided with a position signal, is moved with respect to the magnetic recording medium, and the position is detected by the detection signal. In the position detecting device, the conductive pattern 31 of the FPC (flexible printed circuit) 33 including the base film 30, the conductive pattern 31, and the cover film 32 is bonded at the bonding portion 34, as shown in FIG. 4 and FIG. In order to protect the sensor pattern 38 of the detecting portion 36 provided on the surface of the MR sensor 35 facing the magnetic recording medium, silicon oxide (SiO ₂ ), silicon nitride (SiN) or resin is formed on the sensor pattern 38. The film was formed with a thickness of several tens of microns by vacuum deposition or the like, and was used as the protective film 37 of the sensor pattern 38.

At this time, the base film 30 has a thickness of 20.
.About.30 microns, the conductive pattern 31 has a thickness of 30 to 40 microns, and the cover film 32 has a thickness of 20 to 30 microns.

[0004]

However, the above-mentioned MR
In the sensor device, when the MR sensor 35 is energized, the MR sensor
The sensor pattern 38 formed on the surface of the detection unit 36 of the sensor 35 generates heat, and the temperature distribution is not uniform on the surface of the detection unit 36 as shown by the dotted line in FIG.
There was the inconvenience that the detection signal was disturbed. The present invention has been made in view of the above points, and an object thereof is to propose an MR sensor device that can obtain a stable detection signal.

[0005]

An MR sensor device according to the present invention is arranged, for example, as shown in FIGS. 1 to 3, so as to face a detected means 1 in which a position signal is recorded and to move relative to the detected means 1. An MR sensor device for detecting a position signal output from a position signal detected by the detection unit 9 and a signal line 12 for extracting a signal from the MR sensor unit 2.
And a protective film 15 covering almost the entire MR sensor part 2.
And a heat exchange film 10 covering substantially the entire surface of the detection unit 9 of the MR sensor unit 2 and having a conductive material substantially equivalent to the signal line 12,
At least one end of the signal line 12, the protective film 15, and the heat exchange film 10 are covered with a coating film 11 that covers almost the entire surface of the MR sensor unit 2.

In the MR sensor device of the present invention, the thickness of the heat exchange film 10 added to the protective film 15 is equal to the thickness of the signal line 12.

[0007]

According to the present invention described above, since the heat exchange film 10 having a conductive material substantially equivalent to that of the signal line 12 is provided, when the heat is generated in the detection portion 9 of the MR sensor portion 2, the heat exchange film 10 is removed. Since heat is exchanged inside, the temperature distribution on the surface of the detection unit 9 of the MR sensor unit 2 becomes uniform, so that a stable detection signal can be obtained.

Further, according to the present invention, the thickness of the heat exchange film 10 added to the protective film 15 is equal to the thickness of the signal line 12, so that the signal line 12 is inserted from above the protective film 15 and the heat exchange film 10. Since the surface of the coating film 11 that covers at least one end and almost the entire surface of the MR sensor unit 2 is linear and the detection surface of the MR sensor unit 2 and the surface of the coating film 11 are parallel, Position adjustment between the sensor unit 2 and the magnetic recording medium 1 becomes easy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The M of the present invention will be described below with reference to FIGS.
An example of the R sensor device will be described in detail. Figure 1
In FIG. 1, 1 is a magnetic recording medium magnetized at equal intervals and provided with position signals, and 2 is an MR sensor for detecting the position signals recorded on the magnetic recording medium 1. An FPC 3 is attached to the MR sensor 2 and sends the position signal detected by the MR sensor 2 to the preamplifier 4.

Reference numeral 5 is a case, and 6 is a cover thereof. Reference numeral 7 denotes a wiper for removing dust adhering to the surface of the magnetic recording medium 1, which is fitted in a hole 8 provided in the case 5. Here, the detailed configuration of the MR sensor unit will be described below. In FIG. 2, a discard pattern 10 having a thickness of 40 μm is provided so as to cover the detecting portion 9 of the MR sensor 2.
The base film 11 covering the surface of the FPC 3 is provided from the joint 13 between the conductive pattern 12 and the MR sensor 2 to the MR sensor 2
It is an extension of the entire surface of.

In this case, as shown in FIG. 3, in order to protect the sensor pattern 14 of the detecting portion 9, silicon oxide (SiO ₂ ), silicon nitride (SiN) or a resin film is formed on the sensor pattern 14. Sensor pattern 1 is formed with a thickness of several tens of microns by vacuum deposition or coating.
4 was used as the protective film 15. A cover film 16 is provided on the FPC 3 so as to sandwich the conductive pattern 12 with the base film 11. At this time, the base film 11 has a thickness of 20 to 30 microns and the conductive pattern 1
2 has a thickness of 30 to 40 μm, and the cover film 16 has a thickness of 20 to 30 μm. Needless to say, the cover film 16 may be thinner than this if the above-mentioned configuration can be taken.

An embodiment of the MR sensor device of the present invention is constructed as described above and operates as follows. When the MR sensor 2 moves toward the magnetic recording medium 1, the MR sensor 2 sends the position signal recorded on the magnetic recording medium 1 to the preamplifier 4 via the FPC 3. The position signal amplified by the preamplifier 4 is sent to a display device (not shown).

As shown in FIG. 3, the discarded pattern 1 is formed on the protective film 15 which covers the sensor pattern 14 of the detector 9.
Since 0 is provided, heat is exchanged by the conductive material inside the discard pattern 10, so that the temperature distribution of the sensor pattern 15 is uniform on the surface of the detection unit 9.
As a result, a stable detection signal can be obtained.

According to this example, since the heat exchange film 10 is provided, when heat is generated in the detection unit 9 of the MR sensor unit 2, heat is exchanged inside the heat exchange film 10 to detect the MR sensor unit 2. Since the temperature distribution of the entire section 9 becomes uniform, stable position signal detection can be performed.

Further, according to the above example, since the thickness of the heat exchange film 10 added to the protective film 15 is equal to the thickness of the signal line 12, the signal line 12 is inserted from above the protective film 15 and the heat exchange film 10. Since the surface of the coating film 11 that covers at least one end and almost the entire surface of the MR sensor unit 2 is linear and the detection surface of the MR sensor unit 2 and the surface of the coating film 11 are parallel, Position adjustment between the sensor unit 2 and the magnetic recording medium 1 becomes easy.

The above embodiment is an example of the present invention.
It goes without saying that various other configurations can be adopted without departing from the scope of the present invention.

[0017]

According to the present invention, since the heat exchange film is provided, when heat is generated in the detection part of the MR sensor part, heat is exchanged inside the heat exchange film, and the entire detection part of the MR sensor part is Since the temperature distribution becomes uniform, stable position signal detection can be performed. Further, according to the present invention, the thickness of the protective film to which the heat exchange film is added is equal to the thickness of the signal line. Therefore, at least one end portion of the signal line and the MR sensor unit from above the protective film and the heat exchange film. The surface of the coating film that covers almost the entire surface of the
Since the detection surface of the sensor section and the surface of the coating film are parallel,
Position adjustment between the MR sensor unit and the magnetic recording medium becomes easy.

[Brief description of drawings]

FIG. 1 is a diagram of an embodiment of an MR sensor device of the present invention.

FIG. 2 is a plan view and a side view showing a main part of an embodiment of an MR sensor device of the present invention.

FIG. 3 is a side view showing a further main part of an embodiment of the MR sensor device of the present invention.

FIG. 4 is a plan view and a side view showing a main part of a conventional MR sensor device.

FIG. 5 is a side view showing a further main part of a conventional MR sensor device.

[Explanation of symbols]

 1 Magnetic Recording Medium 2 MR Sensor 3 FPC 4 Preamplifier 5 Case 6 Cover 7 Wiper 8 Hole 9 Detecting Section 10 Discarding Pattern 11 Base Film 12 Conductive Pattern 13 Joint Section 14 Sensor Pattern 15 Protective Film 16 Cover Film

Claims (2)

[Claims] 1. An MR sensor device, which is arranged so as to oppose to a means to be detected having a position signal recorded therein and which moves relative to the means to be detected, said MR sensor device having a detector and being detected by said detector. An MR sensor unit that outputs a position signal, a signal line that takes out a signal from the MR sensor unit, a protective film that covers substantially the entire surface of the MR sensor unit, and the detection unit of the MR sensor unit from above the protective film. Of the MR sensor part and at least one end of the signal line from the top of the protective film and the heat exchange film, and the MR sensor part. An MR sensor device comprising: a coating film that covers the MR sensor device. 2. The MR sensor device according to claim 1, wherein a thickness obtained by adding the heat exchange film to the protective film is substantially equal to a thickness of the signal line.