JPS63176350A - Slider for thin film magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a slider for a thin film magnetic head for a magnetic disk device, and particularly to a slider that has good sliding properties with a magnetic disk and good workability. and its manufacturing method.

[Conventional technology]

In the field of magnetic disk drives, the flying gap between a magnetic disk and a magnetic head is becoming narrower in order to meet the increasing demand for higher recording densities. moreover.

Development of thin-film magnetic heads and thin-film disks with good magnetic properties is also progressing.

A thin-film magnetic head slider has a thin-film element on its rear end surface, and its lower air bearing surface (sliding surface) is held in contact with the magnetic disk surface. The slider has the function of floating upward, so the slider always slides transiently on the magnetic disk when starting or stopping rotation of the magnetic disk.

Furthermore, the narrowing of the floating gap (0.1-0.3 μm) increases the chances of unexpected contact occurring.

For this reason, damage to the magnetic disk due to contact and sliding of the slider has become a problem. In particular, this becomes a bigger problem in the case of thin film disks. That is,
Since the thickness of the magnetic layer (recording layer) of a thin-film disk is extremely small (0.05 to 0.1 μm), the amount of damage allowed is extremely small. For this reason, there is a strong desire for a slider that does not damage the magnetic disk due to sliding.

Conventional methods for improving the slidability (lubricity) of a slider include, for example, Japanese Patent Application Laid-open No. 56-107326,
There is a method disclosed in Publication No. 77949. These are -5
-1 Overcoat the slider sliding surface with organic lubricant.

If it is overcoated, the effect will not last long, and if it is thickly overcoated, the effective floating gap cannot be reduced. Further, when impregnated, there is a problem that the slider and the magnetic disk may stick together due to the impregnation.

In order to solve these problems, it is best to use a solid lubricant as the lubricant, typically Mo5z, WS
There are sulfides such as x. Proposals using these methods include, for example, a method of forming a sputtered film of solid lubricant on the sliding surface of a slider, as disclosed in Japanese Patent Laid-Open No. 58-150122. However, this method has the problem that the lubricating film is only a few hundred thin at most, so the desired effect is not necessarily achieved, and the head manufacturing process is complicated because a sputtering process is required. . Another proposal is a method of forming a slider using a mixture of an organic resin and a solid lubricant, as disclosed in JP-A No. 59-3742. However, this method uses a soft organic resin. is the main
As a result, the slider is prone to wear and deformation, and there are also problems in that it is extremely difficult to process a high-precision product like the slider.

[Problem that the invention seeks to solve]

As described above, in the conventional slider, it is difficult to maintain good and healthy sliding performance (lubricity) with the magnetic disk over a long period of time.

An object of the present invention is to provide a slider for a thin film magnetic head that has good lubricity with a magnetic disk over a long period of time.

Another object of the present invention is to provide a slider material that has good workability and is suitable for efficient production of a large amount of sliders.

[Means for solving problems]

The above object is achieved by using a sintered body mixed with an appropriate amount of solid lubricant and other inorganic compounds as the slider material.

To achieve this, it is necessary to obtain a mixed sintered body of the main material, an inorganic compound, and a solid lubricant, but the temperature is lower than the temperature at which chemically stable and generally used inorganic compounds are sintered. Since the sublimation and decomposition temperatures of sulfide solid lubricants such as Mo5s and W Sz used in the present invention are quite low, it has been difficult to produce the above-mentioned mixed sintered body. That is, when the temperature is raised to obtain a sintered body, the solid lubricant disappears due to sublimation and decomposition before the main material is sintered.

[Effect]

The present invention will be described in detail below.

In the mixed sintered body according to the present invention, sulfides such as MoSx and WSx are typically used as the solid lubricant. Since these solid lubricants are uniformly contained inside the sintered body, the solid lubricants are always exposed on the sliding surface of the slider obtained by machining the sintered body.

However, during sliding with the magnetic disk, the above-mentioned soft solid lubricant is preferentially slid out and forms a lubricating film on the slider sliding surface, so that good lubricity is exhibited over a long period of time. In addition, since the main material is an inorganic compound, the sintered body is not excessively soft, and when processing the sintered body, the heat generated by grinding with a grinding wheel is reduced due to the lubricating action of the solid lubricant inside. Ru. This reduces wear on the grinding wheel and
Processing speed can be increased.

In the mixed sintered body according to the present invention, the volume ratio of the solid lubricant is 1
~50% is good; less than 1% cannot expect a lubricating effect;
If it exceeds 50%, the sintered body becomes too soft, causing problems in precision workability and deformation resistance.

To produce a mixed sintered body, Mo5z.

The sintering temperature must be lowered to a temperature at which WSz etc. do not disappear; in the case of WSx, it is 1200°C or less.

In the case of Mo5t, the temperature is 1150°C or lower. In order to obtain a dense sintered body at such a temperature, the main inorganic compound is made of fine powder with a particle size of 0.1 μm or less. The solid lubricant uses raw powder having a particle size of at least 5 μm or less.

Since these raw material powders have small particle sizes, their surfaces are active and the sintering temperature is low. Furthermore, in order to sinter at a lower temperature, it is preferable to mix the LM material uniformly with the inorganic compound that is the main material, and then hot press or
Sintering is performed by increasing the temperature while applying pressure using the hot isostatic press method.

It is difficult to obtain a dense sintered body without applying pressure b).

〔Example〕

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to these examples.

<Example 1> ZrOx powder with a particle size of 0.03 μm (8moQ
% Y2O3 in solid solution), 0.05 μm Ti
Oz powder, 0.1 pm Ca○ powder, and MgO powder were used as main raw materials. Mo5s powder with a particle size of 1 μm was used as the solid lubricant raw material.

After adding the M o S z powder to the main material powder so that the volume ratio to the main material becomes the ratio shown in Table 1,
Acetone was added to the mixed powder and ball-silled for 72 hours to mix uniformly.

Table 1: After the obtained slurry was dried, it was filled into a mold, compacted and subjected to hot press firing. In the hot press, the sample was loaded into a graphite mold, the graphite was compressed using a hydraulic press, and the sample was heated by high frequency induction to a temperature of 1100'C while applying a pressure of 600 kgf/cd, and fired for 1 hour.

When the obtained mixed sintered body was subjected to X-ray diffraction, it was found that each contained the main material and the solid lubricant (Most), and the M o S
z had not disappeared. Further, the sintered body had almost no pores and was sufficiently dense.

The sintered body is machined into a slider shape. Figure 0 shows an example of a slider for a thin-film magnetic head." Sliding properties (lubricity) between the manufactured slider and magnetic disk
was said in the following steps. First, the sliding surface of the slider was placed on the magnetic disk and held by a gimbal spring, and then the magnetic disk was rotated for 30 seconds at a rotational speed such that the circumferential speed at the slider position was 40 m/sec, and then stopped.

The magnetic disk was started and stopped repeatedly to cause the slider and the magnetic disk to slide, and the number of repetitions until a sudden load was applied to the jinpul spring due to damage to the magnetic disk was measured. However, measurements over 200,000 times were discontinued. The magnetic disk used was a coated type disk in which an organic resin in which Fθgos magnetic powder and A Q zOs filler powder were kneaded was coated on the surface of an A Q /M g alloy disk. For comparison, conventional slider material AΩion/
A TiC mixed sintered body was also used.

Table 1 shows the measurement results, according to this table.

The mixed sintered body, which is mainly made of oxides of ZrOz, TiOx, CaO, and MgO and contains 1 to 50% Mo5s, has a sliding number of times (sliding life) until the gimbal spring receives a sudden load. It's close to 200,000 times, but more. In contrast, the conventional material, AQzOa/TiC sintered body, was approximately 49,000 times. After 200,000 tests, the gimbal spring was not subject to sudden loads, and when we observed the magnetic disk, we found almost no damage. On the other hand, scratches were observed on the magnetic disk where the gimbal spring was subjected to sudden loads.

As described above, according to this embodiment, the sintered body mixed with M o S x has the effect of maintaining good slidability (lubricity) with the magnetic disk over a long period of time.

<Example 2> Twelve types of sintered bodies shown in Table 2 were produced in the same manner as described in Example 1.

Table 2 However, the solid lubricant was changed to WSx, and the firing temperature by hot press was 1200°C.

When the obtained mixed sintered bodies were examined by X-ray diffraction, it was found that all of them were W.
Sx had not disappeared. Further, the sintered body had almost no pores and was sufficiently dense.

A slider was produced from the obtained sintered body, and its sliding properties (lubricity) with respect to the magnetic disk were examined in the same manner as described in Example 1. Table 2 shows the results. According to this, WSz is 1~
The mixed sintered body containing 50% of the gimbal spring has a sliding number of times (sliding life) of approximately 200,000 times or more before receiving a sudden load, which is higher than the conventional material AQzOa/TiC.
This is more than four times that of a sintered body. 1 magnetic disk whose gimbal spring did not receive sudden loads even after 200,000 tests! Upon inspection, almost no damage was observed. Scratches were found on other magnetic disks.

According to this example, the sintered body mixed with WSz has the effect of maintaining good slidability (lubricity) with the magnetic disk over a long period of time.

<Example 3> Using the Zr0z powder and MoSz powder described in Example 1, the ratio of MoS2 was adjusted to 0 as shown in Table 3.
Mixed sintered bodies with varying concentrations of .about.70% were prepared in the same manner as described in Example 1.

The obtained sintered body was examined for grinding resistance, coefficient of friction with the magnetic disk, and wear.

The grinding resistance is a diamond grindstone ($
400), grooves were formed on this sintered body, and the load was detected and measured using a piezoelectric element attached to a spindle for rotating a grindstone. The m constant value was standardized with the case where Mo5z was not mixed as 100.

The coefficient of friction with the magnetic disk was calculated by fabricating a slider similar to that described in Example 1, placing its sliding surface on the magnetic disk and holding it with a gimbal spring, and setting the rotation speed at a circumferential speed of 5 m/see at which the slider did not float. The magnetic disk was rotated, and the force applied to the gimbal spring at this time was detected and measured by a strain gauge attached to the gimbal spring. The measured value was normalized with the case where Mo5t was not mixed as 100.

As for the wear of the sintered body 1, after the slider was manufactured, it was repeatedly slid on the magnetic disk in the same manner as described in Example 1, and this was repeated 200,000 times.

The deformation of the slider sliding surface was investigated using an optical interference microscope.

Table 3 shows these measurement results. A sintered body containing 1% or more of Mo5z has a grinding resistance that is at least 25% lower than a sintered body that contains less than that amount, and a coefficient of friction with the magnetic disk of 30%. % or more smaller. On the other hand, wear (
Deformation) did not occur when the proportion of Mo5t was 50% or less. That is, on the sliding surface of a slider that was repeatedly slid against a magnetic disk 200,000 times, the slider with a Mo5s ratio of 70% had diagonal sag, but the slider with a Mo5s ratio of 50% or less did not sag. In addition, as a result of observing the sliding surface of the slider with a microscope, clear scratches were observed on the sliders containing 0% and 0.5% of Mo5s. Similarly, scratches were also seen on the magnetic disks that slid against these.

The above measurement results were the same when the solid lubricant was WSx and when the main material was other TiOz, CaO, etc.

According to the above embodiments, when the mixing ratio of the solid lubricant (Moss) is 1% or more, the grinding resistance and the coefficient of friction are reduced, and there is an effect that no damage is caused to the magnetic disk over a long period of time. On the other hand, if the mixing ratio is more than 50%, the slider itself will wear out due to sliding, which is not preferable as a slider for a thin-film magnetic head.

〔Effect of the invention〕

According to the present invention, the flying gap of the head is reduced, the recording density is improved, and the life of the magnetic disk is extended. In addition, processing efficiency can be increased, so
High-precision sliders can be efficiently manufactured in large quantities.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a thin film magnetic head slider according to an embodiment of the present invention. 1... Thin film element forming surface, 2... Magnetic disk sliding surface, ・'711pi1;Chang;'

Claims (1)

[Scope of Claims] 1. A slider for a thin film magnetic head, characterized in that it is a mixed sintered body of an inorganic compound as a main material and a solid lubricant as an auxiliary material. 2. The inorganic compounds include ZrO_2, TiO_2, Ca
The slider for a thin film magnetic head according to claim 1, characterized in that the slider contains one or more of O, MgO, and NiO oxides. 3. The slider for a thin film magnetic head according to claim 1 or 2, wherein the solid lubricant contains at least sulfides of WS_2 and MoS_2. 4. Claim 1, 2 or 3, characterized in that the solid lubricant has a volume ratio of 1 to 50%.
A slider for a thin film magnetic head described in .