JPH03232174A - Floating magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To prevent sticking caused on a head and disk face by specifying a repetitive pitch of crest and trough at least at part of a face opposite to a magnetic recording medium and the difference between the crest and the trough. CONSTITUTION:The crest 28 and the trough 29 appear alternately on a bearing face opposite to a magnetic recording medium and a point between the crest 28 and the trough 29 is a part (cliff) in which the height is rapidly changed. The cliff part is set optionally at a desired point independently of the crystal particle diameter, grain boundary and arrangement. A mean value of a difference (d) of the depth between the crest 28 and the trough 29 is 50 - 200A, a repetitive pitch (e) of the crest 28 and the trough 29 is caused at a pitch of 5 - 200mum with a prescribed regularity. Thus, the sticking between the head and the disk is prevented or relaxed by providing a proper step difference to the crest 28 and the trough 29 at a proper pitch.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a floating magnetic head and a method for manufacturing the same, and in particular to a floating magnetic head (hereinafter referred to as head) for a small hard disk using a thin film medium. ) and its manufacturing method.

(Prior art) Conventionally, hard disks as magnetic recording media have mainly been made by coating oxide magnetic powder on aluminum alloy substrates, but in response to recent demands for high recording density, plating methods,
Hard disks in which a magnetic material is adhered to a substrate using a sputtering method or the like are becoming mainstream. The magnetic disk device uses hard disks using the above-mentioned plating method, sputtering method, etc.

Discs are becoming smaller and more portable, and the motors that drive the discs are also becoming thinner and have lower torque.

(Problem to be solved by the invention) The surface of the disk made by the plating method, sputtering method, etc. described above has a better surface accuracy than that of the conventional coating method, and the lubricant is applied in excess. Because the disc is coated, the sticking phenomenon that occurs between the head and the disk surface, which has not been a problem in the past, has become a problem. As the surface precision of the surface facing the magnetic recording medium increases,
The surface of the stationary disk and the surface of the head facing the disk become sticky. If the viscous force between the head and the disk becomes excessively strong, the lifespan of the device will be reduced to C3.
S (contact, start, stop) life will be shortened. In particular, the problem becomes even more serious in devices that combine a large number of disks. In order to alleviate such a sticking phenomenon, various methods have been considered to increase the surface roughness of the disk facing surface of the head to some extent, but none of them have been sufficiently effective.

However, as disclosed in Japanese Patent Application Laid-Open No. 1-251308, the present inventors have developed a method of forming a surface of a floating magnetic head made of polycrystalline material, using a reverse sputtering method to form a surface facing the magnetic recording medium. By setting the difference between the depths of the peaks and valleys to 50 to 200 people, and the average pitch of repeating peaks and valleys to 5 to 20 μm,
We succeeded in improving the CSS lifespan. However, since the above invention uses the fact that the binding energy differs depending on the plane orientation of each crystal grain of a polycrystalline material to create unevenness, the applicable materials are limited to polycrystalline materials, and There is a constraint that the portion whose height changes into a valley extends along the grain boundaries of the crystal. Therefore, it cannot be applied to materials without crystal grains such as single crystals, and even in the case of polycrystalline materials, if the crystal grains are extremely large or small, it is said that the desired surface condition and surface roughness cannot be obtained. have an issue.

Therefore, as a result of further intensive studies, the present inventors found that it is applicable to single-crystal materials, and in the case of polycrystal materials, it is not affected by the grain size, grain boundaries, arrangement, etc. of the crystal grains. In addition, we succeeded in finding a solution to obtain a predetermined surface condition and surface roughness.

(Means for Solving the Problems) In order to solve the above problems, in claims (1) to (3), in a floating magnetic head made of a non-magnetic material or a magnetic material, a floating magnetic head facing a magnetic recording medium is provided. At least a portion of the surface has an average depth difference of 50 to 200 ridges and an abrupt change in height from ridge to trough, at least arbitrarily selected, and the crystal grains The unevenness is provided without being influenced by the diameter, grain boundaries, or arrangement, and in claim (1),
The average pitch of peaks and valleys is 5 to 200 μm.
In claim (2), the repetition of peaks and valleys has a certain regularity, and the pitch of the repetition is 5 to 2 on average.
00 μm, and in claim (3), the repetition of peaks and valleys has a certain regularity, the pitch of the repetition is in the range of 5 to 200 μm, and furthermore, at least near the top of the peak. The object of the present invention is to provide a floating magnetic head whose surface condition and surface roughness have substantially constant geometrical regularity.

In addition, claim (4) provides: on the surface facing the magnetic recording medium;
According to claim (5), there is provided a magnetic head characterized in that at least the convex portion on the top surface is constituted by a flat surface;
The average amplitude of the waviness of substantially the entire surface of the disk-facing surface of the magnetic head, or a portion thereof, was measured using a stylus-type roughness meter using a roughness curve of 50 to 300. Claim (6) provides a floating magnetic head having the surface condition and surface roughness provided in Claims (1) to (5) using ceramics, crystallized glass, single crystal, or polycrystalline magnetic head. The present invention provides a magnetic head made of at least one of crystalline oxides.

Claims (7) and (8) provide a method for manufacturing a magnetic head, and claim (7) provides a method for manufacturing a magnetic head, and claim (7) applies a photoresist liquid to a surface that is not to be processed and faces a magnetic recording medium. , the surface to be processed on which the photoresist is not coated is a photoresist surface in which a photoresist liquid is applied to substantially the entire surface facing the magnetic recording medium, and the surface to be processed is masked. After exposing the surface using a mask and removing the unexposed photoresist on the surface to be processed, the surface to be processed is etched in a predetermined manner by one method selected from reverse sputtering, ion milling, or chemical etching. It is characterized by processing the surface condition and surface roughness.

Hereinafter, the configuration and operation of the present invention will be explained in detail.

In the present invention, the magnetic head may be of a monolithic type or of a composite type.

FIG. 1 is a perspective view showing an example of a monolithic magnetic head 10. Usually polycrystalline Ni-Zn or M
Although it is integrally composed of n -Z n ferrite, M
If it is made of n - Z n single crystal ferrite, the electromagnetic conversion characteristics will be further improved. Alternatively, Mn-Zn single-crystal ferrite may be used only on the surface facing the recording medium or only in the electromagnetic transducer, and composite ferrite using polycrystalline ferrite may be used in other parts.

The slider designated by numeral 1 has two main bearing surfaces 2.3.
on its sides. At the center of the slider 1, a narrow bearing surface extends parallel to the main bearing surface 2.3 in the form of a ridge. A core 6 is bonded to the rear end of the bearing surface 4 through a magnetic gap 5 using glass or the like. A thin alloy film with high magnetic permeability may also be formed on the joint surfaces of the core 6 and the slider 1 (front gap and pack gap). A wire is wound around the core 6 through the winding window 7 in a predetermined turn.

In addition, as a magnetic alloy with high magnetic permeability, an Fe-A Q-5i alloy commonly known as Sendust is suitable. Particularly suitable Fe-AM-8i magnetic alloys include those in which AQ: 2 to 10%, Si: 3 to 16%, the remainder being substantially Fe, and AΩ: 4 to 8%. , Si
: 6 to 11%, with the remainder being substantially Fe.

Incidentally, it is preferable that Ti and Ru are contained in an amount of 2% or less each because corrosion resistance and abrasion resistance can be improved. Further, the same effect can be obtained even if Cr is contained in an amount of 4% or less.

In addition, as a high permeability magnetic alloy, a Co-Nb-Zr amorphous alloy (for example, 70 to 90 at% CO, N
containing 5 to 20 at% b and 2 to 10 at% Zr)
is also suitable.

FIG. 3 is a perspective view showing an example of a composite magnetic head. The magnetic head 11 is a non-magnetic slider, or
Consisting of a magnetic slider 12 and a chip 13, the chip 1
3 is molded and fixed in a slit 16 formed in one of the two bearing surfaces 14 and 15 of the slider 12 using glass or the like.

A detailed structure of an example of the chip 13 is shown in FIG.

In FIG. 4, sputtered films 22 and 23 are formed on the C-shaped core 20 and the I-shaped core 21. As shown in FIG.

The C-shaped core 20 and the engineered core 21 are glass-bonded with a gap 24 between them. 25 indicates glass. Further, winding is applied to the I-shaped core 21 through the winding window 26 so as to form a predetermined pattern.

The constituent material of the chip 13 is polycrystalline M n
-Zn ferrite, Ni-Zn ferrite, etc. are suitable, and Mn-Zn ferrite is particularly suitable. Suitable compositions of Mn-Zn ferrite include MnO: 25-37%, ZnO: 8-23%,
Fe2O: 51 to 57%. In addition, single-crystal M n -Z n ferrite is also suitable, and its preferred composition range is mol%, M n O: 26 to 32%, Z
n○: 14-21%, Fe2O: 50-55%.

As the material of the slider 12 shown in FIG. 3, crystallized glass or polycrystalline nonmagnetic ceramic materials are preferably used, and examples thereof include calcium titanate, barium titanate, alumina, zinc ferrite, and zirconia ceramics. Of course, other non-magnetic materials may also be used, such as Mn-
Magnetic materials such as Zn may also be used.

In the invention, the bearing surfaces 2.3.4 and 14.1
The surface of No. 5 is processed so that it has a specific surface condition and surface roughness. When the head 10.11 is in its normal stopped position, the area A in FIG.
In the present invention, all of these areas A, B, and C are processed to have the above-mentioned specific surface roughness. However, only area A may be processed, or only the main part of area A, for example, the hatched area in FIG. 2, may be processed.

FIG. 5(a) is a sectional view schematically showing a bearing surface of a head according to an embodiment of claims (1) and (4), and FIG. .

As shown in the figure, peaks 28 and valleys 29 appear alternately on the bearing surface, and between the peaks 28 and valleys 29 there is a part (cliff) where the height changes rapidly.This cliff part is a crystalline part. It is possible to arbitrarily set it at a desired location regardless of the grain size, grain boundaries, and arrangement of the grains. The average value of the difference d in depth between the peaks 28 and the valleys 29 is 50 to 200, and the pitch e of the repetition of peaks and valleys is 5 to 200 μm in (a), and (b) ), they occur with a certain regularity in the range of 5 to 200 μm. Further, the cross-sectional shape of the mountain is irregular in (a), but in (b) it has a certain geometric regularity at least near the top of the mountain.

As described above, since the peaks 28 and the valleys 29 have an appropriate level difference and are repeated at an appropriate pitch, and because the contact area with the disk is small, the sticking phenomenon between the head and the disk occurs. will be prevented or alleviated.

In addition, in the present invention, since the convex portion on the top surface is made of a flat surface, it is possible to reliably avoid the phenomenon of the head scratching the disk surface when the head lands on the disk surface or conversely when taking off from the disk. It is thought that this also improves the C8S characteristics.

The coefficient of static friction between the disk and the head can be kept at 1.0 μm or less, preferably at 0.7 or less. This coefficient of static friction is determined by pressing a magnetic head onto a stationary magnetic disk using a gimbal with a force of approximately 8 g-f, and measuring the force (torque) required to start the rotation of the magnetic head. was converted into a friction coefficient.

To form such a bearing surface, as described later, you can mask the peaks by spraying a photoresist solution, or you can apply a photoresist solution to the surface facing the recording medium and fill in the valleys of the bearing surface. The portion (to-be-processed surface) to be formed is exposed using a masked photomask, the unexposed photoresist is removed, and ion milling, chemical etching, or reverse sputtering may be used. In addition, when treating the bearing surface by each of the above methods, the amplitude of the waviness of the bearing surface or a part thereof is measured using a stylus type roughness meter and the roughness is 50 to 300. The head also achieves the objectives of the invention.

Ion milling was performed using a Kaufmann type device. This device has an initial vacuum level of 0°01 to 0.03 in the milling chamber.
Vacuum degree after introducing Pa and Ar gas: 0.05 Pa, acceleration voltage approximately IKV, ion current density 0.5-1 mA/
Under the conditions of aJ, the generated Ar ions are accelerated with an ion gun, and the Ar ion beam is applied to the surface of the treated material, and the atoms of the treated material are bounced off by the impact, resulting in purely physical etching. The etching rate can be adjusted by arbitrarily selecting the incident angle of the ions with respect to the material.

In the reverse sputtering method, the normal sputtering method applies a high voltage to ionize Ar gas in an inert gas atmosphere such as Ar gas, and causes it to collide with the target surface, and the target particles that fly out at that time are transferred to another substrate. In contrast, in the reverse sputtering method, two electrodes facing each other are installed in a vacuum chamber, evacuated to -degree vacuum, and then Ar gas of 0.1 to 1.0 Pa is introduced. Then, a voltage of 0.5 to IKv is applied between the two electrodes to cause a glow discharge, and ionized Ar in the plasma collides with the surface of the treatment material placed inside, thereby removing atoms on the surface of the treatment material.

The chemical etching method uses a chemical reaction between a chemical reagent and the processing material to perform the processing, and involves heating a hydrochloric acid or phosphoric acid solution and immersing the processing material in the solution for a predetermined period of time. The type, concentration, solution temperature, immersion time, etc. of the chemicals to be used are appropriately selected depending on the material of the treated material, predetermined surface roughness, and surface condition.

(Example) Example 1 The disk facing surface was made of Mn-Zn single crystal material with a composition of Mn○: 28 mol%, ZnO: 19 mol%, Fe, 03: 53 mol%, and the other parts were Mn - Using a monolithic floating magnetic head made of polycrystalline Zn material,
The single crystal surface was finished to a surface roughness of approximately 20 mm by float polishing. Next, the surface was washed to remove adsorbed moisture, and then a photoresist solution was applied as a jet stream from a nozzle to the treated surface of the single crystal using a spray method.

After the film was formed, baking treatment was performed and chemical etching was performed. During chemical etching, the electromagnetic transducer was masked to prevent etching.

The etching conditions were as follows: 12.5 wt% hydrochloric acid solution
The magnetic head was heated to 0°C and immersed for 5 to 15 seconds. Because of the plane orientation determined by the etching conditions, unevenness of peaks and valleys occurred between the areas masked by the photoresist film and the areas where no film was formed. FIG. 5(a) shows its cross-sectional view.

Example 2 Mn0: 31 mol%, ZnO: 16 mol%, F (12
03: A magnetic head made of a polycrystalline material consisting of 53 mol % was used, and the surface facing the disk was finished with a surface roughness of 10 to 40 by wet lapping using fine diamond abrasive grains. Then wash the surface.

After removing the adsorbed moisture, a photoresist was applied by spin coating, and baked at a temperature of 130° C. for about 30 minutes to obtain a flat film-formed surface with a layer thickness of 5 μm.

Next, a photomask having a circular image with a diameter of 30 μm and a pitch of 100 μm is aligned with the processed surface of the magnetic head that has been deposited, exposed to light, and treated with a developer to remove unexposed areas. A photoresist film having a circular image was then formed, post-baked, and reverse sputtered.

An R-F type sputtering device was used, the size of the turntable was set to Φ42aa, the input power was set to 0°5Kw, Ar was used as the gas, and the gas pressure was 0.44 to 0.4.
It was set to 8Pa. FIG. 6 shows the relationship between reverse sputtering time and surface roughness. Although these relationships change depending on conditions such as input time, type of inert gas, composition of several gases, and gas pressure, the roughness still changes approximately in proportion to time. The relationship is such that the slope of the line changes as the line moves forward. The removal amount of the head surface at this time is also shown in Figure 6, and the circular part without photoresist is removed during reverse sputtering, and the part where photoresist remains is not removed and returns to its original state. As a result, we were able to create a head with a partial contact surface with the disk, as shown in Figure 2. FIG. 7 shows the change in the static friction force generated between the disk and the head when the height difference between the peaks and valleys of the head is changed, measured in relation to the number of repetitions of C8S. In the conventional case using only wet lapping, the frictional force increases as the number of C8S repetitions increases, and the amount of increase changes greatly after 10,000 times. In contrast,
The head having a step between peaks and valleys according to the present invention also has a small frictional force. From this, it is thought that the rougher the step on the surface of the head facing the disk, the greater the effect, but if the surface is too rough, there may be a problem of scratches on the head and disk.

The upper limit is the difference in depth between peaks and valleys where no scratches occur.

Example 3 A floating magnetic head that had been pretreated with photoresist by spraying in the same manner as in Example 1 was used, and the floating magnetic head was placed in the same RF magnetron sputtering device as above. Set it at the specified position on the table (diameter 420m), input power 0.3-1. OKw, Ar
Gas pressure 0.4~0.5Pa, reverse sputtering time 10~60
The disk-facing surface of the floating magnetic head was surface-treated by changing the surface of the floating magnetic head. As a result, the floating magnetic head of the present invention obtained is as shown in FIG.

In FIG. 2, the shaded area is the area whose surface was treated by reverse sputtering, and the other areas were masked with photoresist so that the surface would not be treated during reverse sputtering. The surface roughness of the thus surface-treated portion was measured using a stylus roughness meter. An example of the resulting roughness curve is shown in FIG. The roughness curve shows periodic waviness.

As shown in FIG. 8, the average wavelength λ of the undulations is continuous as shown in FIG. ．． ．． Remove L and □ L~L21
The distance Q between them was measured and calculated from λ=Q/20.

Note that the roughness curve was measured at 10 locations over a distance of 5 cm, and the average value of the 10 locations was defined as λ. Moreover, Rmax was 0.020 to 0.030 μm in all cases. C8S of this floating magnetic head having various λ obtained as described above, a sputter disk and a plating disk.
When the characteristics were measured, the difference between the peak and valley depths was 50 to 300.
For humans, it was confirmed that the static friction coefficient μm was maintained at 0.7 or less even when the number of C8S cycles was 30,000 or more, and neither spatter nor plated disks were crushed. When λ exceeds 200 μm, the coefficient of static friction μm rapidly increases to 0.7 or more, and the disk crashes after less than 5,000 cycles, similar to a normal floating magnetic head, and when λ=5
It has become clear that disk crashes occur in less than 10,000 cycles even when the thickness is less than .mu.m.

Example 4.5, Comparative Example 1.2 In Example 1, the reverse sputtering time was 0 minutes, (Comparative Example 1), 10 minutes (Example 4), 20 minutes (Example 5), 3
0 minutes (Comparative Example 2).

C8S Test Example 1 A C8S test was conducted using the heads of Example 4.5 and Comparative Example 1.2.

The disk used for the C8S is the following 3.5 inch hard disk.

Substrate Nialuminum base: Cr Magnetic film: Co-Ni sputtered film Surface layer: C sputtered layer and fluororesin lubricant applied to the surface of the C layer (lubricant thickness: 10 to 30) Disk surface roughness : 400 to 600 people The disk drive conditions during the C8S test were as follows.

Rotation speed: 3600 rpm One rotation speed near sec Stop time between rotations: 3 sec While conducting this C8S test, the static friction coefficient μm between the head and the disk was measured. The results are shown in FIG. 9 along with the number of C8S repetitions.

The following is recognized from Figure 9.

In Example 4.5, even after performing C8S 100,000 times, the coefficient of static friction μ is approximately 0.6 or less, and there is no abnormality in either the disk or the head. In Comparative Example 1, 10,000 times of C
With the 8S, an abnormal noise was heard when the disk and head made contact, and with the C8S, which had been run 40,000 times, failures were sometimes observed when starting the disk rotation. In Comparative Example 2, the static friction coefficient μ
Although m is low, scratches begin to appear on both the head and disk surface after 20,000 C8S cycles.

CSSSS Toss 2 The same test as in Test Example 1 above was conducted except that the following plating disk was used.

Substrate Nialuminum base: N1-p Magnetic film: Co-Ni Surface layer: C and lubricant (same as test example 1) This C8S
The results of the test example are shown in FIG.

From FIG. 10, the same results as in Test Example 1 can be seen.

(Effect of the invention) As is clear from the above examples, claims (1) to (
The head of 6) has a small coefficient of static friction with the disk, and even if C8S is repeatedly performed, both the disk and head surfaces are hard to be damaged and have good durability.

According to claims (7) and (8), the above head can be manufactured.

As described above, the present invention makes it possible to reduce the friction that occurs between the disk and the head, and by using an inexpensive and stable method, it is possible to further reduce the size and size of the disk device.
It will be possible to respond to lighter weight and thinner walls.

Furthermore, according to the present invention, it is possible to reduce the friction that occurs between the sputter disk, the plating disk, and the flying magnetic head, so that the life of the C8S can be extended.

[Brief explanation of drawings]

1 and 2 are perspective views of a monolithic floating magnetic head, FIG. 3 is a perspective view of a composite floating magnetic head, FIG. 4 is a perspective view of a head chip, and FIG. ), (
b) is a cross-sectional view of the bearing surface, Figures 6, 7, and 8.
, FIG. 9, and FIG. 10 are graphs showing the measurement results, respectively. 1.10. ,, head 2.3.4, 14.15. ,,bearing surface 28,,,
Mountain, 29. ,,Tani,30. ,, Cliff 31.32.33.3
4.35.36.37.38.39.40.41. ,,
crystal grains. Figure 1 Figure 2 Figure 5 (a) (b) Figure 6 Reverse sputtering time (minutes) Figure 7 SS number of times (xloooo) Figure 8

Claims (8)

[Claims] (1) In a floating magnetic head made of a non-magnetic material or a magnetic material, at least one part of the surface facing the magnetic recording medium has a surface with a repeating pitch of peaks and valleys of 5 to 200 μm on average. , the difference in depth between peaks and valleys is 50 to 200 Å on average, and the portion where the height changes rapidly from peak to valley is at least arbitrarily selected, and the grain size, grain boundaries, and arrangement of the crystals A floating magnetic head that is characterized by its unevenness, which is not influenced by any influence. (2) At least a portion of the surface facing the magnetic recording medium has a certain regularity in which the peaks and valleys are repeated, and the pitch of the repeats is in the range of 5 to 200 μm; The difference in height is on average 50 to 200 Å, and the region where the depth changes rapidly from peak to valley is at least arbitrarily selected and depends on the grain size, grain boundaries, and arrangement of the crystals. A floating magnetic head characterized by having an uneven structure. (3) At least a portion of the surface facing the magnetic recording medium has a certain regularity in which the peaks and valleys are repeated, and the pitch of the repeats is in the range of 5 to 200 μm, and the peaks and valleys are The difference in depth is 50 to 200 Å on average, the shape at least near the top of the mountain has almost geometric regularity, and the depth changes rapidly from the mountain to the valley. What is claimed is: 1. A floating magnetic head characterized by having irregularities selected at least arbitrarily and without being affected by grain size, grain boundaries, or arrangement of crystals. (4) A floating magnetic head characterized in that at least the convex portion of the top surface of the surface facing the magnetic recording medium is formed of a flat surface. (5) substantially the entire surface of the magnetic head facing the magnetic recording medium;
A floating magnetic head characterized in that the average amplitude of the waviness of a portion thereof is 50 to 300 Å as measured by a roughness curve using a stylus roughness meter. (6) The floating magnetic head according to any one of claims (1) to (5), wherein the non-magnetic material or the magnetic material is composed of at least one of ceramics, crystallized glass, single-crystalline or polycrystalline oxides. . (7) Apply a photoresist solution to the surface facing the magnetic recording medium that is not to be processed, and apply a reverse sputtering method, ion milling method, or chemical etching method to the surface to be processed to which the photoresist is not applied. A method for manufacturing a floating magnetic head, characterized by processing the surface to a predetermined surface condition and roughness by one method selected from among them. (8) A photoresist solution is applied to almost the entire surface facing the magnetic recording medium, and the surface to be processed is exposed using a masked photomask, leaving the unexposed photoresist on the surface to be processed. 1. A floating magnetic head characterized in that after removing the surface, the surface to be processed is processed to a predetermined surface condition and surface roughness by one method selected from among reverse sputtering, ion milling, and chemical etching. manufacturing method.