JPH06221868A - Mr sensor device - Google Patents

Abstract

PURPOSE:To propose an MR sensor device of simple configuration that provides stable detection signal. CONSTITUTION:An MR sensor 2, faced to a magnetic recording media, moves relative to it. The sensor produces a signal which is output through an FPC 3. The whole conductive pattern 11 of the FPC 3 and substantially the whole surface of the sensor are covered with a film 10.

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 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 detected signal. In the position detecting device for detecting, as shown in FIG.
1. In order to protect the pattern of the detection part 36 provided on the surface of the MR sensor 35, which has the conductive pattern 31 of the FPC (flexible printed circuit) 33 composed of the cover film 32, bonded at the bonding part 34 facing the magnetic recording medium. In addition, silicon oxide (SiO ₂ ), silicon nitride (SiN), or a resin film was formed on the pattern with a thickness of several tens of microns by a vacuum deposition method or coating to form the pattern protective film 37. Here, the base film 30
Has a thickness of 20 to 30 microns, and the conductive pattern 31 has a thickness of 3
0 to 40 microns, cover film 32 has a thickness of 20 to 3
It is 0 micron.

[0003]

However, the above-mentioned MR
In the sensor device, if the thickness of the protective film 37 is thin, dust or the like may enter the position detecting device and damage the detection unit 36. Therefore, the film thickness of the protective film 37 is made thicker. However, in the film forming method described above, it takes a long time to form the film or the film thickness becomes uneven. There was an inconvenience that the cost increased.

It is also conceivable to attach a plate material having a considerable thickness to the MR sensor surface as a protective cover, but the plate material is a separate component, resulting in an increase in cost. Further, when the protective cover 38 is attached to the MR sensor surface, as shown in FIG. 7, the adhesive 39 adheres to the detecting portion 36 provided on the MR sensor surface,
Since the adhesive 39 thermally expands due to a change in the usage environment, there is a disadvantage that stress is applied to the detection unit 36 and the characteristics of the MR sensor 35 are disturbed.

Further, when the protective cover 38 is attached to the MR sensor surface, as shown in FIG. 7, if the protective cover 38 is attached up to the joint of the FPC 33, the thickness of the FPC 33 corresponds to the detection surface of the MR sensor 35. Since the surface of the protective cover 38 is attached in an inclined state, the MR sensor 3
However, it is impossible to confirm whether or not the arrangement positions of the magnetic recording medium 5 and the magnetic recording medium arranged opposite thereto are proper, and thus the detection signal may be disturbed. The present invention has been made in view of the above point, and it is an object of the present invention to propose an MR sensor device that simplifies the configuration and can obtain a stable detection signal.

[0006]

An MR sensor device according to the present invention is arranged, for example, as shown in FIGS. 1 to 5, so as to face a detected means 1 in which a position signal is recorded and to move relative to the detected means 1. A MR sensor device for outputting a position signal, a signal line 11 for extracting a signal from the MR sensor part 2, at least one end of the signal line 11 and almost the entire surface of the MR sensor part 2. It is composed of a coating film 10 for coating.

Further, the present invention is an MR sensor device which is arranged so as to face the detected means 1 which has recorded a position signal and moves relative to the detected means 1, and which has a detecting portion 13 and a detecting portion. The MR sensor unit 2 that outputs the position signal detected by 13, and the signal line 11 that extracts the signal from the MR sensor unit 2.
And a correction film 18 that covers almost the entire surface of the MR sensor unit 2 except the detection unit 13 and has a thickness substantially equal to that of the signal line 11.
19, at least one end of the signal line 11 and the correction film 1
The coating film 16 covers the entire surfaces of 8 and 19, and the protective film 20 is provided on the coating film 16 so as to cover the entire surface of the MR sensor portion 2.

[0008]

According to the present invention described above, the coating film 10 continuously coats at least one end portion of the signal line 11, the coupling portion 12 between the signal line 11 and the MR sensor portion 2 and the MR sensor portion 2. Therefore, the coating film 10 of the signal line 11 also serves as a protective cover of the MR sensor unit 2. Further, according to the present invention, the coating film 16 covers the substantially entire surface of the MR sensor unit 2 except the detection unit 13 and has the same thickness as the signal line 11 and the coating film 16 is formed on the correction films 18 and 19. Since at least one end of 11, the coupling portion 12 of the signal line 11 and the MR sensor portion 2 and the MR sensor portion 2 are covered, the coating film 16 is covered with the MR sensor portion 2 without steps, and the protective film 20 is covered. It can be mounted parallel to the MR sensor unit 2.

[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 the figure, 1 is a magnetic recording medium, and 2 is an MR sensor for detecting a position signal recorded on the magnetic recording medium 1. 3 is M
The FPC is attached to the R sensor 2 and sends the position signal detected by the MR sensor 2 to the preamplifier 4.

Reference numeral 5 is a protective cover made of a copper alloy and attached to the detection surface side of the MR sensor 2 substantially parallel to the detection surface and having a thickness of about 0.1 mm. Reference numeral 6 is a case for storing these, and 7 is a cover thereof. Reference numeral 8 denotes a wiper for removing dust adhering to the surface of the magnetic recording medium 1, which is fitted in a hole 9 provided in the case 6.

The detailed structure of the MR sensor unit will be described below. FIG. 2 is an example in which the base film 10 covering the surface of the FPC 3 is extended from the joint 12 between the conductive pattern 11 and the MR sensor 2 to the detection surface of the MR sensor 2.
In this case, the extended base film 10 is the detection unit 13
Use a protective cover to protect the pattern surface of. FP
A cover film 14 is provided on C3 so as to sandwich the conductive pattern 11 with the base film 10.

An embodiment of the MR sensor device of the present invention is constructed as described above and operates as follows. By moving the MR sensor 2 so as to face 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). In this case, even if dust or the like exists on the magnetic recording medium 1, the protective cover 5 can prevent the dust or the like from entering the detection surface of the MR sensor 2. According to the above example
The base film of FPC is the whole surface of FPC, FPC and M
The base film also serves as a protective cover of the MR sensor unit because the joint with the R sensor unit and the MR sensor are continuously covered.

FIGS. 3 and 4 are views showing the main part of another embodiment of the MR sensor device of the present invention, in which the shape of the base film is the detection part 13 provided on the detection surface of the MR sensor 2.
The pattern is excluded. 3 shows the base film 15 formed in a U-shape, and FIG. 4 shows the base film 16 formed in a U-shape.

In this case, a protective cover as shown in FIG. 7 is provided so as to cover the entire MR sensor 2 from above the base films 15 and 16. At this time, the adhesive 17 for adhering the protective cover is adhered so that it does not adhere to the pattern of the detection unit 13 provided on the detection surface of the MR sensor 2 as shown by the diagonal lines. According to the above example, since the adhesive does not adhere to the MR sensor surface, the MR sensor is not affected by the thermal stress of the adhesive and stable position signal detection is possible even when the environmental temperature changes. I can.

FIG. 5 is a view showing the main part of another embodiment of the MR sensor device of the present invention, which has the same shape as the base film 16 formed in the square shape shown in FIG. 4 and has the conductive pattern of the FPC 3. 11, the cover film 18 or the discard pattern 19 having substantially the same thickness as the MR sensor 2 and the base film 16 are provided.
Between the base film 16 and the MR sensor 2
A protective cover 20 is provided so as to cover the whole. Also in this case, the adhesive 17 for adhering the protective cover is M as shown by the diagonal lines.
The R sensor 2 is bonded so as not to adhere to the pattern of the detection unit 13 provided on the detection surface of the R sensor 2.

The thickness of the cover film 18 or the discard pattern 19 is about 30 μm. As a result, the thickness of the conductive pattern 11 of the FPC 2 is corrected, so that the surface of the protective cover 20 can be attached in parallel with the detection surface of the MR sensor 2. Therefore, the attachment position of the MR sensor and the magnetic recording medium can be adjusted. Can be easily confirmed, the mounting time of the MR sensor can be simplified, and stable position signals can be detected. Here, generally, the base film 16 has a thickness of 20 to 30 μm, the conductive pattern 11 has a thickness of 30 to 40 μm, and the cover film 14 has a thickness of 20 μm.
It is about 30 microns, but it goes without saying that it may be thinner than this as long as it has the above-mentioned function.

According to the above example, since the base film of the FPC continuously covers the entire surface of the FPC, the joint between the FPC and the MR sensor part, and the MR sensor, the base film serves as a protective cover for the MR sensor part. Also plays a role. Further, according to the above example, the base film of the FPC covers almost the entire surface of the MR sensor except the detection part, and the base film is formed on the cover film or the discard pattern having a thickness almost equal to that of the FPC. Since the entire surface, the joint between the FPC and the MR sensor, and the MR sensor are continuously covered, and the entire surface is covered with the protective cover, the protective cover can be attached in parallel with the MR sensor.

Further, according to the above example, since the adhesive does not adhere to the MR sensor surface, the MR sensor is not affected by the thermal stress of the adhesive and is stable in position even if the environmental temperature changes. Can detect signals. Further, according to the above example, since the protective cover can be mounted in parallel with the MR sensor, it becomes easy to confirm the mounting position of the MR sensor and the magnetic recording medium, and the mounting work time of the MR sensor can be simplified. In addition, stable position signals can be detected.

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.

[0020]

According to the present invention described above, the coating film continuously covers the entire surface of the signal line, the coupling portion between the signal line and the MR sensor section, and the MR sensor section, so that the signal line is covered. The membrane is M
It can also serve as a protective cover for the R sensor part,
The configuration can be simplified. According to the invention,
Since the adhesive does not adhere to the MR sensor surface, MR
The sensor is not affected by the thermal stress of the adhesive, and stable position signals can be detected even if the environmental temperature changes. Further, according to the present invention, since the protective film can be attached in parallel to the MR sensor portion, it becomes easy to confirm the attachment position of the MR sensor portion and the magnetic recording medium, and the installation work time of the MR sensor portion can be simplified. In addition, it is possible to achieve stable and stable position signal detection.

[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.

3A and 3B are a plan view and a side view showing a main part of an embodiment of an MR sensor device of the present invention.

FIG. 4 is a plan view and a side view showing a main part of an embodiment of an MR sensor device of the present invention.

5A and 5B are a plan view and a side view showing a main part of an embodiment of an MR sensor device of the present invention.

FIG. 6 is a diagram showing a main part of a conventional MR sensor device.

FIG. 7 is a diagram showing a main part of a conventional MR sensor device.

[Explanation of symbols]

 1 Magnetic Recording Medium 2 MR Sensor 3 FPC 4 Preamplifier 5 Protective Cover 6 Case 7 Cover 8 Wiper 9 Holes 10, 15, 16 Base Film 11 Conductive Pattern 12 Bonding Part 13 Detection Part 14 Cover Film 17 Adhesive 18 Cover Film 19 Discard Pattern 20 Protective cover

Claims (2)

[Claims] 1. An MR sensor device, which is arranged so as to be opposed to a detection means for recording a position signal and moves relative to the detection means, wherein an MR sensor section for outputting the position signal and the MR are provided. M comprising a signal line for taking out a signal from the sensor unit and a coating film for coating at least one end of the signal line and substantially the entire surface of the MR sensor unit.
R sensor device. 2. An MR sensor device, which is arranged so as to face a detected means for recording a position signal and moves relative to the detected means, the MR sensor device having a detecting section and being detected by the detecting section. A correction that covers the MR sensor unit that outputs a position signal, a signal line that extracts a signal from the MR sensor unit, and substantially the entire surface of the MR sensor unit except the detection unit, and that has a thickness that is substantially equal to that of the signal line. A film, a coating film that covers at least one end of the signal line and the entire surface of the correction film, and a protective film that is provided on the coating film so as to cover the entire surface of the MR sensor unit. An MR sensor device characterized by the above.