JPH0644535A - Floating type magnetic head - Google Patents

Abstract

PURPOSE:To provide the floating type magnetic head which can prevent the incidental generation of noises and the damage, etc., of magneto-resistance elements and has excellent reliability and durability. CONSTITUTION:This floating type magnetic head is the floating type magnetic head having the magneto-resistance elements 4 and is constituted by forming nonmagnetic insulating layers 3 on at least the exposed parts of the magneto- resistance element parts 4 on the floating surface of a slider 1. SiO2, ZrO2, Ta2O5, SiN, TiN, etc., are adequately used as the material of the nonmagnetic insulating layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating magnetic head used in a fixed disk device or the like.

[0002]

2. Description of the Related Art In recent years, the processing speed of computers has been improved,
With the increase in storage capacity, fixed disk devices having high speed and large capacity are becoming popular. In particular, in order to further increase the capacity, it is desired to develop a floating magnetic head that uses a magnetoresistive element (hereinafter abbreviated as MR element) that detects magnetism with high sensitivity and indicates the change by its own resistance value change as a read element. Japanese Patent Publication No. 59-35088 discloses a floating magnetic head in which this MR element is exposed on the air bearing surface of a slider facing a magnetic recording medium.

A conventional floating magnetic head will be described below. 6A is a side view of a slider of a conventional floating magnetic head, FIG. 6B is a bottom view of the slider, FIG. 6C is a rear view of the slider, and FIG. 7 is a slider. FIG. 3 is a cross-sectional view of a main part of the MR element part of FIG.

Reference numeral 1 is a slider made of ceramics such as ferrite or alumina titanium carbide and ground into a desired shape, and 2 is a surface of the slider 1 facing the magnetic recording medium (not shown) and parallel to the inflow direction of air. The groove portions 3 provided on the surface of the slider 1 are provided on the surface of the slider 1 facing the magnetic recording medium (not shown), and are processed to have extremely high smoothness by using loose abrasive grains such as the lapping method. The air bearing surface for floating the slider 1 by the lift force applied, and 4 are Fe-
An MR element 5 made of a Ni-based alloy or the like, which serves as a reading element of the floating magnetic head, is made of an oxide or the like and covers a portion other than the lower end portion of the MR element 4 and is a protective layer for improving the reliability of the MR element 4.

In order to obtain a voltage change as an output from the MR element 4 which shows a change in external magnetic flux as a change in its own resistance value, it is necessary to pass a current through the MR element 4. Therefore, as shown in FIG. 7, the MR element 4 is used in a state in which an electric current is passed in a direction perpendicular to the paper surface.

The operation of the conventional floating type magnetic head constructed as described above will be described below.

FIG. 8 is a side view showing the flying state of the slider, FIG. 9 is a sectional view of an essential part showing a state where the MR element and a protrusion on the magnetic recording medium are in contact, and FIG. FIG. 4 is a cross-sectional view of a main part showing a state in which the magnetic recording medium is in contact with the magnetic recording medium.

Reference numeral 6 is a magnetic recording medium on which data and the like are recorded,
Reference numeral 7 denotes a protrusion formed on the magnetic recording medium 6 itself or a protrusion formed of an adhered matter such as dust on the magnetic recording medium 6.

As shown in FIG. 8, the slider 1 flies at an angle of θ with respect to the magnetic recording medium 6 by the air flow generated by the rotation of the magnetic recording medium 6. At this time, the distance between the MR element 4 and the magnetic recording medium 6 (hereinafter referred to as the flying height)
Is maintained at about 0.2 (μm).

However, as shown in FIG. 9, when there is a protrusion 7 higher than the flying height on the magnetic recording medium 6, this and M
The R element 4 was in contact or collided.

Further, as shown in FIG. 10, when an impact or the like is applied from the outside, the MR element 4 and the magnetic recording medium 6 are in contact with each other.

[0012]

However, in the above conventional structure, since the MR element is exposed on the air bearing surface,
When the magnetic recording medium has a protrusion higher than the flying height, or when an impact or the like is applied from the outside, the MR element and the magnetic recording medium come into contact with or collide with each other, and the magnetic recording medium 6 and the MR element 4 are separated from each other. M by electrical conduction, heat conduction and frictional heat
Since the temperature of the surface of the R element 4 changes rapidly, the output voltage of the MR element fluctuates to generate pulse noise, which causes an error in reading data.

Further, when the contact with the magnetic recording medium is repeated while the MR element is energized, the MR is contacted within several tens of times.
There are also problems that the electrical characteristics such as the output of the element are deteriorated, the MR element is damaged, and the MR element melts due to frictional heat at the time of contact and Joule heat due to conduction.

The present invention solves the above-mentioned conventional problems, and provides a floating type magnetic head having excellent reliability and durability capable of preventing the occurrence of sudden noise and damage to MR elements. The purpose is to

[0015]

In order to achieve this object, a floating magnetic head of the present invention is a floating magnetic head having an MR element, which is not exposed at least on the exposed surface of the MR element on the air bearing surface of the slider. It has a structure in which a magnetic insulating layer is formed.

Here, the material of the non-magnetic insulating layer is S
iO ₂ , ZrO ₂ , Ta ₂ O ₅ , SiN, TiN and the like are preferably used.

[0017]

With this configuration, even if the floating magnetic head comes into contact with the magnetic recording medium or the like, noise can be prevented from occurring, and at the same time, damage to the MR element caused by repeated contact can be prevented. .

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a side view of a slider of a floating magnetic head according to an embodiment of the present invention, and FIG.
1 is a bottom view of the slider, FIG. 1C is a rear view of the slider, and FIG. 2 is a cross-sectional view of an essential part of the MR element portion of the slider.

1 is a slider, 2 is a groove portion, 3 is an air bearing surface, 4
The MR element and the protective layer 5 are the same as those in the conventional example, and therefore, the same reference numerals are given and the description thereof is omitted.

Reference numeral 8 is a nonmagnetic insulating layer made of a nonmagnetic insulating material and covering the exposed portion of the MR element 4 to the air bearing surface 3.

The non-magnetic insulating layer 8 is made of a non-magnetic insulating material such as SiO _{2 on the} entire surface of the air bearing surface 3 by sputtering, vacuum deposition, CV.
1 to 100 (nm), preferably 5 to 50 depending on the D method or the like
(Nm) formed by forming a film.

The floating state of the floating magnetic head of this embodiment having the above-described structure will be described below.

FIG. 3 is a cross-sectional view of essential parts showing a state in which the floating magnetic head and the projection on the magnetic recording medium are in contact with each other. Reference numeral 6 is a magnetic recording medium, and 7 is a protrusion. These are the same as those in the conventional example and are assigned the same reference numerals and their explanations are omitted.

In the floating magnetic head of this embodiment, the non-magnetic insulating layer 8 is provided even when the protrusion 7 is present on the magnetic recording medium 6 and is in contact with the protrusion 7, so that M
It is possible to prevent the R element 4 from directly contacting the protrusion 7. In addition, the electrical conduction between the MR element 4 and the magnetic recording medium 6 and the local heat radiation phenomenon and frictional heat due to the heat conduction on the surface of the MR element 4 which have been generated at this time can be eliminated, so that the pulse noise is eliminated. Can be prevented. Further, it is possible to prevent damage to the MR element 4 caused by repeating this contact while the MR element 4 is energized.

The same excellent effect can be obtained even when the floating magnetic head and the magnetic recording medium 6 come into direct contact with each other due to an external impact.

Performance comparison tests were carried out on the floating magnetic head of the present embodiment and the conventional floating magnetic head. The results will be described below.

(Experimental Example) A magnetic recording medium 6 was prepared by assembling the floating type magnetic head in this example and demagnetizing the whole 3.5 inch metal thin film medium for hard disk before the experiment.
The magnetic recording medium 6 is rotated at a rotational speed of 3600 (rpm), and the floating magnetic head in the present embodiment is moved to a position of 25.4 (mm) from the center of the magnetic recording medium 6.
It was levitated with a flying height of 1 (μm).

In this state, the output voltage of the MR element 4 was measured with an oscilloscope while the MR element 4 was kept in the reproducing state. The measurement result is shown in FIG.

FIG. 4 is a graph showing the output voltage curve of the experimental example. (Comparative Example) The output voltage of the MR element 4 was measured under the same conditions as in the experimental example, except that a conventional floating magnetic head having no nonmagnetic insulating layer 8 on the air bearing surface 3 was assembled. The result is shown in FIG.

FIG. 5 is a graph showing the output voltage curve of the comparative example. As is clear from FIG. 4, the output voltage of the experimental example was almost 0, and no noise was observed. On the other hand, in the comparative example, it was confirmed that pulse-like noise as shown in FIG. 5 was generated every 2 to 3 seconds although it was irregular.

Next, after the experiment was completed, the floating magnetic heads used in the experimental example and the comparative example were removed from the magnetic disk device, and the surface of each MR element 4 was observed to measure the electrical characteristics. 4 was damaged, and the electrical characteristics such as the output of the MR element 4 were deteriorated. On the other hand, in the experimental example, such damage and deterioration of electric characteristics were not observed.

In this embodiment, the nonmagnetic insulating layer 8 is used.
Is formed on the entire surface of the air bearing surface 3, but the MR element 4 on the air bearing surface 3
It may be formed only on the exposed portion.

As described above, according to this embodiment, it is possible to prevent the occurrence of sudden noise in the output voltage of the MR element 4 and the damage to the MR element 4.

[0035]

As described above, according to the present invention, a non-magnetic insulating layer such as SiO ₂ is formed on at least the exposed portion of the MR element on the air bearing surface, so that the magnetic recording medium or the like can be easily contacted. It is possible to realize a floating magnetic head having excellent reliability and durability, which can prevent noise generated and prevent damage to the MR element and the like caused by repeating this contact.

[Brief description of drawings]

FIG. 1A is a side view of a slider of a floating magnetic head according to an embodiment of the present invention. FIG. 1B is a bottom view of a slider of a floating magnetic head according to an embodiment of the present invention. Rear view of slider of floating magnetic head in example

FIG. 2 is a sectional view of an essential part of an MR element portion of a slider of a floating magnetic head according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of essential parts showing a state in which a floating magnetic head is in contact with a protrusion on a magnetic recording medium.

FIG. 4 is a graph showing an output voltage curve of an experimental example.

FIG. 5 is a graph showing an output voltage curve of a comparative example.

6A is a side view of a slider of a conventional floating magnetic head, FIG. 6B is a bottom view of a slider of a conventional floating magnetic head, and FIG. 6C is a rear view of a slider of a conventional floating magnetic head.

FIG. 7 is a sectional view of an essential part of an MR element part of a slider of a conventional floating magnetic head.

FIG. 8 is a side view showing a flying state of a slider of a conventional floating magnetic head.

FIG. 9 is a cross-sectional view of essential parts showing a state where an MR element and a protrusion on a magnetic recording medium are in contact with each other.

FIG. 10 is a sectional view of an essential part showing a state where an MR element and a magnetic recording medium are in contact with each other.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 slider 2 groove part 3 air bearing surface 4 MR element 5 protective layer 6 magnetic recording medium 7 protrusion 8 non-magnetic insulating layer

Claims (1)

[Claims] 1. A floating magnetic head having a magnetoresistive element, wherein a nonmagnetic insulating layer is formed on at least an exposed part of the magnetoresistive element on an air bearing surface of a slider.