JPH1196529A - Magnetic head and magnetic disk drive - Google Patents

Abstract

[PROBLEMS] To increase the polishing amount of a thin-film magnetic head in the downstream portion of the disk rotation without adding a processing step, and to increase the distance between the recording / reproducing element portion of the magnetic head and the magnetic disk during operation of the apparatus. To decrease the closest distance between a magnetic head and a magnetic disk without reducing it, and to increase the information recording density on the magnetic disk surface. An upper protective film of a recording / reproducing element portion of a thin-film magnetic head is formed so that the surface to be polished is larger on the surface than the lower portion, and the polishing amount at the time of polishing the surface facing the magnetic disk of the magnetic head is reduced immediately after the element portion. The distance from the magnetic disk closest to the magnetic disk to the recording / reproducing element of the thin-film magnetic head is reduced, and the rear end of the magnetic head is formed in a desired shape without additional processing steps. The above purpose is achieved by forming.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk storage device for recording / reproducing information by relative movement of a magnetic disk and a magnetic head, and more particularly to a magnetic head formed by a thin film process and a magnetic head using the magnetic head. It relates to a disk device.

[0002]

2. Description of the Related Art In a conventional magnetic disk drive, it is required from the principle of magnetic recording to shorten the interval between a magnetic head and a magnetic disk in order to increase the recording density of information. For this reason, it is common practice to shorten the distance as a whole by reducing the size of the magnetic head. In this method, since the closest distance between the magnetic head and the magnetic disk is also shortened at the same time, the probability of contact between the magnetic head and the magnetic disk is increased, and there is a possibility that friction and wear of the two may occur, thereby deteriorating the reliability of device operation. is there. One method for preventing this problem and reducing the distance between the recording / reproducing element unit and the magnetic disk without reducing the closest distance between the magnetic head and the magnetic disk is disclosed in Japanese Patent Application Laid-Open No. 4-60976.
As disclosed in Japanese Unexamined Patent Publication, it has been proposed that the magnetic head outflow portion be additionally flattened.

[0003]

However, in this prior art, after the surface facing the magnetic disk of the magnetic head is polished as usual, additional processing of the inclined surface at the rear end is performed, thereby increasing the number of processing steps by one. At the same time, special measures were required to detect the end of the additional work.

An object of the present invention is to provide a magnetic head and a magnetic disk drive capable of shortening the distance between an information recording / reproducing element and a magnetic disk without adding a processing step and improving the information recording density on the magnetic disk surface. Is to provide.

[0005]

According to the present invention, in a thin-film magnetic head having a recording / reproducing element portion and a non-magnetic film around the recording / reproducing element portion, the polished property of the non-magnetic material around the recording / reproducing element is measured from the vicinity of the recording / reproducing element. With a configuration that is partially changed, the polishing amount of the non-magnetic material is changed in a desired order around the read / write element in the magnetic disk facing surface polishing step,
A desired curved surface, a flat surface, or a composite surface of the two is formed on the surface facing the magnetic disk so that the recording / reproducing element portion of the magnetic head can be brought closer to the magnetic disk.

[0006]

FIG. 1 shows a first embodiment of a magnetic head according to the present invention.

The magnetic head 20 of this embodiment has a tapered flat floating surface 24 consisting of a tapered surface 26 and a flat surface 25 on the surface of the magnetic head 20 facing the magnetic disk, similarly to the conventional magnetic head 20. I have. A recording / reproducing element section 30 is formed on a side surface of the taper flat type flat surface 25 opposite to the taper surface, that is, on the flat surface rear end 50 side, and is used for recording and reproducing information.

FIG. 2 shows details of a section around the magnetic head element in a cross section of the magnetic head slider.

A taper surface 26 and a flat surface 25 are formed on the hard substrate 22 on the side facing the magnetic disk, and a non-magnetic under film 21, a recording / reproducing element unit 30, and upper protective films 1 and 2 are formed on one of the flat surfaces. Is formed. The upper protective film is composed of two layers, one and two, having different polishing properties. Each of the tapered surface 26, the flat surface 25, the base film 21, the recording / reproducing element portion 30, and the upper protective films 1 and 2 is provided with a carbon protective film 40 of 20 nm on the side facing the magnetic disk.

Upper protective film 1 in contact with recording / reproducing element unit 30
Has a thickness of 10 μm, and the upper protective film 2 has a thickness of 30 μm. Since the polishing property of the upper protective film 1 is smaller than that of the upper protective film 2,
The portion of the upper protective film 1 is formed to be convex with respect to the upper protective film 2, and the portion of the upper protective film 2 is concave with respect to the flat surface 25.

The magnetic head 20 formed as described above has
When the magnetic disk drive is operating, as shown in FIG.
The distance between the air inflow side (hereinafter abbreviated to the inflow side) of the magnetic disk 10 and the magnetic disk 10 is larger than the space between the air outflow side (hereinafter abbreviated to the outflow side) of the recording / reproducing element unit 30. Surface with a certain slope.

In the conventional magnetic head, since the upper protective film has a single layer, the upper protective film on the outflow side of the recording / reproducing element section 30 is polished almost parallel to the flat surface 25. The distance between the magnetic disk 30 and the magnetic disk is larger than the closest distance of the magnetic head, which is the distance between the outflow end of the upper protective film and the magnetic disk, by an inclination.

In the magnetic head 20 of this embodiment, the upper protective film is composed of the upper protective film 1 having a small polishing property and the upper protective film 2 having a large polishing property. 1 is the closest part between the magnetic head 20 and the magnetic disk 10 and the increase in the distance between the read / write element unit 30 and the magnetic disk 10 due to the inclination can be kept small. Since the distance between the reproducing element unit 30 and the magnetic disk 10 can be reduced, the information recording density of the magnetic disk 10 can be increased.

Next, a manufacturing process of the magnetic head will be described with reference to FIG.

The substrate 22 of the magnetic head 20 is made of alumina titanium carbide ceramics.

A lower alumina film 21 is formed as a base film on the smooth polished surface of the substrate 22. Next, the lower magnetic pole,
Recording / reproducing element section 30 including a gap regulating film, an intermediate alumina film, a recording / reproducing winding, a gap insulating film, and an upper magnetic pole
(In the present specification, the above is collectively illustrated as the recording / reproducing element unit 30) is formed according to a normal thin-film magnetic head manufacturing process. Further, an upper alumina film 1 having a thickness of 10 μm is formed as an upper protective film 1 on the surface. Next, the upper protective film 2
The upper alumina film 2 is formed to have a thickness of 30 μm. These upper alumina films 1 and 2 are formed by a sputtering method. Argon was used as a sputtering gas at the time of formation, the gas pressure was 5 mTorr, and the bias voltage at that time was changed to -120 V and -200 V, respectively.

Thereafter, the substrate 22 is cut into predetermined blocks, and a flat surface 25 and a tapered surface 26 are formed on one surface thereof by polishing. The air bearing surface 24 is patterned on the magnetic disk facing surface polished as described above to form a carbon thin film 40. Finally, the block is further cut into individual magnetic head chips, fixed to the head support mechanism 110, and wiring is conducted to complete the magnetic head.

In the above process, the upper alumina films 1 and 2 laminated by changing the bias voltage had a hardness of 7 GPa and 4 GPa, respectively, measured by a micro hardness tester. These upper alumina films 1 and 2 were immersed in an oil-based polishing liquid at a particle size of 1/4 μm.
Polishing is performed on a tin polishing plate, which is a soft metal, with a polishing liquid in which m diamond polishing particles are suspended. Since the polishing property of the upper alumina film 2 is higher than that of the upper alumina film 1,
The polished surfaces of the upper alumina films 1 and 2 have different processing amounts as shown in FIG. That is, the polishing amount of the upper alumina film 2 having low hardness is increased, and the distance from the flat surface 25 of the alumina titanium carbide substrate is reduced.
Polished to increase between. In this embodiment, the uppermost alumina film 2 at the most downstream portion is polished by 30 nm more than the upper alumina film 1.

As described above, in the manufacturing process of the present invention, the outflow portion can be formed in a desired shape without requiring any additional processing such as the outflow end tilting which is conventionally required.
The distance between the recording / reproducing element unit 30 and the magnetic disk 10 can be easily reduced, and the information recording density can be increased.

FIG. 4 shows a magnetic disk storage device to which the magnetic head of this embodiment is mounted. The magnetic disk 10 is fixed to a spindle shaft 13 by a hub 12 and a base 10
The spindle motor 13 is rotated at a predetermined rotation speed together with the spindle shaft 13 by a spindle motor installed on the spindle motor 0. The magnetic head 20
The magnetic disk 10 is fixed to the head support mechanism 110, is pressed against the magnetic disk 10 with a constant load, and travels on the magnetic disk 10 while maintaining a constant posture by an airflow on the magnetic disk 10 generated by rotation of the magnetic disk 10.

The head support mechanism 110 is a carriage arm 1
The magnet 140 is rotatably supported about a pivot shaft 130 and rotated by a current flowing through a voice coil (not shown) provided in the magnetic flux of the magnet 140. The current flowing through the voice coil is controlled so that the magnetic head 20 is at a predetermined track radius position on the magnetic disk 10.

The recording / reproducing element section 30 and the voice coil of the magnetic head 20 are connected to a recording / reproducing control circuit 150 via a flexible wiring 160, and the control circuit controls recording / reproducing of information and positioning control of the magnetic head. .

The control circuit 150 is connected to the computer main body,
Recording and reproduction of information are performed. With this configuration, it is possible to reduce the distance between the recording / reproducing element unit and the magnetic disk without reducing the closest distance between the magnetic head and the magnetic disk without adding a processing step. The information recording density on the surface of the magnetic disk can be increased without a decrease.

FIG. 5 shows a magnetic head 2 according to this embodiment.
0 indicates the operating state. During operation of the apparatus, the flat surface 25 of the magnetic head floats at an angle θ with respect to the magnetic disk surface 10. The recording / reproducing element unit 30 is located on the magnetic head inflow side by a fixed distance L from a re-approaching position 51 between the magnetic head and the magnetic disk, and the distance from the magnetic disk is greater than the closest distance hmin by a slope loss ds (= L sin θ). Just get farther than the disc. In the magnetic head of this embodiment, the upper alumina film 2 is polished by 30 nm more than the upper alumina film 1, and the closest position 51 between the magnetic head 20 and the magnetic disk 10 during operation of the apparatus is L from the recording / reproducing element unit 30.
= 5 μm on the outflow side, and the inclination angle θ is 80 μrad
Therefore, the slope loss ds is 0.4 nm or less.

On the other hand, in the conventional magnetic head, only the upper protective film 1 is formed in a single layer with a thickness of 40 μm.
Is the same as the outflow end, the distance L from the recording / reproducing element unit 30 to the closest position is 40 μm from the outflow end,
A tilt loss ds of only 3.2 nm will occur.

Therefore, in the configuration of the present invention, as described above, the outflow portion can be formed in a desired shape without the need for additional processing such as planar processing, which has been conventionally required, and the inclination loss can be reduced and recording can be performed. The distance between the reproducing element portion and the magnetic disk can be more easily shortened by 2.8 nm or more than the conventional head, and the information recording / reproducing density on the magnetic disk surface can be increased.

Next, another embodiment of the magnetic head for a magnetic disk storage device to which the present invention is applied will be described with reference to FIG.
The magnetic head of this embodiment has the protective films 1 and 2 of the magnetic head described above with reference to FIG.

In this embodiment, the protective film has five layers.
With this configuration, the difference in the amount of polishing during polishing can be more finely controlled, and the accuracy of forming the inclined portion can be improved as compared with the previous embodiment.

In this embodiment, five upper protective films, ie, upper protective films 1, 2, 3, 4, and 5, are sequentially formed as an upper protective film. These upper protective films 1 to 5 are formed by a sputtering method. Argon was used as a sputtering gas at the time of formation, and the gas pressure was 5 mTorr, and the bias voltages at that time were -120 V, -140 V, -160 V, and-respectively.
It is formed by changing sequentially to 180V and -200V.
The upper protective film 1 thus laminated by changing the bias voltage.
Nos. 5 to 7 have hardness values measured by a microhardness tester of 7
Gpa, 6.5Gpa, 6Gpa, 5.5Gpa, and 4GPa. These upper protective films 1 to 5 are coated in an oil-based polishing liquid with a particle size of 1
When a polishing liquid in which / 4 μm diamond polishing particles are suspended is polished on a tin polisher, which is a soft metal, the polished property of the upper protective film increases in the order of 1 to 5; The polished surfaces 3, 4, and 5 are polished so that the processing amount gradually increases and the distance from the flat surface 25 gradually increases. Other processes are the same as those of the first embodiment.

As described above, in the above embodiment, the upper protective film 1
While one step is formed at the boundary between the two layers, the difference in hardness of each of the five layers is small in this embodiment, so that the step at the boundary is small and the change in the overall inclination is formed smoothly. You.

According to this embodiment, the outflow portion can be formed in a desired shape more accurately than the previous embodiment without requiring any additional processing such as processing conventionally required. Can be reduced, and the information recording density on the magnetic disk surface can be increased.

The flat surface 2 of the magnetic head 20 of this embodiment
5 floats on the magnetic disk at an angle of 80 μrad during operation. In this embodiment, when the upper protective film 5 and the upper protective film 1 at the outflow portion are compared, the upper protective film 5 is polished by 30 nm more than the upper protective film 1. For this reason, the closest position between the magnetic head 20 and the magnetic disk during operation of the apparatus is 30 μm from the outflow end, that is, a position at a distance L = 10 μm from the recording / reproducing element unit 30, and the inclination loss ds is 0.8 n.
m or less.

On the other hand, in the conventional head, as described above, the inclination loss is 3.2 nm. As described above, in the present embodiment, the outflow portion can be formed in a desired shape without requiring additional processing such as conventionally required inclined plane processing,
The distance between the recording / reproducing element section and the magnetic disk is set to 2.
It can be easily reduced to 4 nm or more, and the information recording density on the magnetic disk surface can be increased.

The case where the value of the bias voltage at the time of forming the upper protective films 1, 2, 3, 4, and 5 of the above five alumina films by the sputtering method is changed will be described. Argon is used as a sputtering gas at the time of formation, and the gas pressure is 5 mTorr.
And the bias voltage at that time is -140
V, -120V, -140V, -180V, -220V
Are sequentially changed. The upper protective films 1 to 5 laminated by changing the bias voltage as described above have hardnesses of 6.5 GPa, 7 GPa, and 6.5 Gpa, respectively, measured by a micro hardness tester.
Gpa, 5.5Gpa, and 4GPa. The upper protective films 1 to 5 were polished on a soft metal tin polishing board with a polishing liquid in which diamond polishing particles having a particle diameter of 1/4 μm were suspended in an oil-based polishing liquid. The polishing property of the upper protective film is the lowest for the upper protective film 2, and then increases in the order of 1, 3, 4 and 5.
The amount of processing is minimized in the upper protective film 2 of the second layer, the amount of processing is gradually increased above the upper protective film 2, and polishing is performed so that the distance from the alumina titanium carbide substrate plane 25 gradually increases.

According to this method, the position with the least amount of polishing behind the read / write element can be controlled to a desired position by the thickness of the upper protective film 1, and the closest position between the magnetic head and the magnetic disk can be freely determined. be able to. According to this method as well, the outflow portion shape can be accurately formed to a desired shape without requiring additional processing such as conventionally required inclined plane processing, and the information recording density on the magnetic disk surface can be increased. .

In the magnetic head manufactured by the above-described manufacturing method, the outflow portion is polished by 20 nm more. When the magnetic head 20 is mounted on the magnetic disk storage device, the flat surface 25 of the magnetic head 20 has an angle of 80 μrad during operation. Floats on the magnetic disk.

As a result, the closest position between the magnetic head 20 and the magnetic disk during operation of the apparatus is 20 μm from the outflow end, that is, the position at a distance L = 20 μm from the recording / reproducing element unit 30, and the inclination loss ds is It is 1.6 nm or less. On the other hand, the inclination loss of the conventional head is 3.2 n.
m, the present manufacturing method can reduce the tilt loss, reduce the flying spacing by 1.6 nm or more compared to the conventional magnetic head, and increase the information recording density on the magnetic disk surface.

Although the amount of reduction of the inclination loss ds is smaller than that of the previous embodiments, the read / write element 3
The allowable wear thickness until 0 is exposed from the protective film 40 is larger than in the previous embodiments, and the allowable head thickness of the magnetic disk storage device in which the magnetic head 20 and the magnetic disk 10 have a high possibility of contact wear is high. Increasing the wear thickness and the distance h between the read / write element 30 and the magnetic disk 10
In the case of an apparatus which requires both the reduction of g simultaneously, it is possible to change the conditions at the time of design, and it is possible to provide a magnetic disk recording apparatus which can realize a high recording density with high reliability at low cost.

Instead of the above-described method of forming a multilayer upper protective film, there is also a method of forming the upper protective protective film 6 of the magnetic head 20 by continuously changing the bias voltage from -120V to -200V. FIG. 7 shows a magnetic head formed by this method.

Since the upper protective film 6 is formed continuously,
The same pattern is shown. Since the hardness of the upper protective film 6 formed by this method is 7 GPa at the bottom and continuously decreases to 4 GPa at the surface, the polished property continuously increases from the bottom to the surface. As a result, when polished by the same polishing method as described in the previous embodiments, the surface of the upper protective film 6 becomes a slope without any step, which is smoother than when a multilayer upper protective film is formed. According to this method, the outflow portion can be formed into a desired shape without requiring additional processing such as conventionally required inclined plane processing, and information can be recorded at a high density on the magnetic disk surface. Becomes

The magnetic head 20 formed by the present method
However, if the flat surface 25 flies above the magnetic disk during operation at an angle of 80 μrad, the outflow portion is polished by 30 nm more, so that the closest position between the magnetic head 20 and the magnetic disk during operation of the device is 30 μm from the outflow end. Position. This position has a distance L of 10 μm from the recording / reproducing element.
m, and the slope loss ds is 0.8 nm or less.

On the other hand, in the conventional head, the inclination loss is 3.2 nm, and the outflow portion can be formed in a desired shape without any additional processing such as inclined plane processing conventionally required by this method. It can be formed with high precision, and the distance between the recording / reproducing element unit 30 and the magnetic disk 10 is set to be 2.
It can be easily reduced to 4 nm or more, and the information recording density on the magnetic disk surface can be increased.

The material of the upper protective film of the recording / reproducing element unit 30 is
A magnetic head in which the alumina described above is replaced with an alumina-SiO ₂ film will be described with reference to FIG. Although the alumina-SiO ₂ film has improved corrosion resistance as compared with the alumina film described above, the same configuration as that of the example described above can be obtained as follows. When alumina-SiO ₂ is used for the upper protective film 6, the polishing property gradually increases from the side of the recording / reproducing element unit 30 by the sputtering method as in the case of forming the alumina film described above. It is formed as follows. The composition of the target material in the initial stage of the sputtering is 80% carbon and 20% SiO ₂ by weight.
After that, a target of 90% carbon and 10% SiO2 is used. An alumina-SiO ₂ film is formed to a thickness of 20 μm using the initial target material, and a further 20 μm is formed using the next target. At this time, argon is used as a sputtering gas, and the gas pressure of each target is repeatedly set to 2 mTorr at the initial stage of the sputtering, continuously increased gradually, and set to 10 mTorr at the end of the sputtering. With this production, SiO ₂ content of alumina -SiO ₂ film formed in the upper alumina -
25% at the bottom of the SiO ₂ film, but 5% at the outermost surface
To decrease.

An alumina-SiO ₂ film as an upper protective film laminated by changing a bias voltage is coated with a soft metal, tin, which is a soft metal, by using a polishing liquid in which diamond polishing particles having a particle diameter of ４ μm are suspended in a weak alkaline polishing liquid. polishing with a polishing platen, to work also mechanochemical polishing action of weakly alkaline aqueous solution, the polishing amount larger the SiO ₂ concentration of the alumina -SiO ₂ film is small. Since the concentration of SiO ₂ in the upper protective film 6 of this embodiment is gradually reduced at the bottom,
The amount of polishing at the bottom is small, and the amount of polishing increases toward the surface.

As a result, the polished surface of the upper protective film 6 is polished to a smooth curved surface. Other manufacturing processes are the same as those in FIG. Also in this embodiment, even when the amount of the upper electrode protective material is changed, the outflow portion can be formed in a desired shape without requiring additional processing such as conventionally required inclined plane processing, and the magnetic disk surface can be formed. Information recording density can be increased.

[0046]

By using the present invention, the shape of the non-magnetic portion behind the recording / reproducing element portion of the thin-film magnetic head can be made a desired shape without requiring an additional processing step. Therefore, the processing steps can be simplified, the distance between the recording / reproducing element section and the magnetic disk and the inclination loss can be easily reduced, and when applied to a magnetic disk device, the recording density of the disk can be increased. Further, the approach distance between the recording / reproducing element and the magnetic disk can be increased, the probability of contact damage between the two can be reduced, and the reliability of operation of the magnetic disk device can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a magnetic head according to a first embodiment.

FIG. 2 is a view showing a cross section of the magnetic head according to the first embodiment;

FIG. 3 is a diagram showing a manufacturing process of the magnetic head of the first embodiment.

FIG. 4 is a configuration diagram of a magnetic disk storage device according to the first embodiment.

FIG. 5 is a diagram showing a magnetic head operating state according to the first embodiment;

FIG. 6 is a diagram showing a cross section of a magnetic head in which five upper protective films are formed.

FIG. 7 is a view showing a cross section of the magnetic head in which the conditions for forming the upper protective film are continuously changed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Upper protective film 1, 2 ... Upper protective film 2, 3 ... Upper protective film 3, 4 ... Upper protective film 4, 5 ... Upper protective film 5, 6 ... Upper protective film 6, 10 ... Magnetic disk, 11 ... Magnetic Disk rotation direction, 12 hub, 13 spindle bearing, 20 magnetic head, 21 lower protective film, 22 head substrate, 24
Magnetic disk facing surface, 25 flat surface, 26 tapered surface, 30 read / write element, 40 carbon film, 50 flat surface rear end, 51 magnetic disk closest to magnetic disk, 100 base, 110 Head support mechanism, 1
20 ... head arm, 130 ... pivot bearing, 140 ...
Magnet, 150 ... control circuit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Minoru Yamasaka 2880 Kozu, Odawara-shi, Kanagawa Prefecture, Hitachi, Ltd.Storage Systems Division (72) Inventor Toshio Tamura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Within Hitachi, Ltd. Production Technology Laboratory (72) Inventor Kenji Tasaka 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Within Hitachi, Ltd. Production Technology Laboratory

Claims (4)

[Claims] 2. A magnetic head comprising: a read / write element including a base film formed on a substrate; and a protective film made of a nonmagnetic material around the read / write element. A magnetic head comprising two or more layers. 2. The magnetic head according to claim 1, wherein, of the protective films formed on the two or more layers, the protective film formed on the outer side has a higher polishing property than the protective film on the inner side. A magnetic head characterized by an increase. 3. A disk driven to rotate, a head support mechanism provided with a magnetic head for recording or reproducing information on or from the disk, a head arm coupled to the head support mechanism, and rotating the head arm. A magnetic disk drive comprising: a drive unit for driving; a recording / reproducing element unit in which the magnetic head is formed on a substrate; and two or more protective films formed outside the recording / reproducing element unit; A magnetic disk drive characterized in that the film has a characteristic that the polishing property gradually increases toward the outside. 4. A magnetic disk drive according to claim 3, wherein the distance of the magnetic head from the recording medium at the rearmost portion of the surface facing the recording medium is larger than the closest distance between the magnetic head and the recording medium. Magnetic disk drive.