JPS6318511A - Recording head slider - Google Patents

Abstract

PURPOSE:To provide a titled slider which has excellent durability and adaptability to a recording medium and is less deteriorated in medium recording characteristic with age and to improve the machinability thereof by forming a slider body of a sintered body having the basic compsn. consisting of 10-40vol% SiC and the balance Al2O3. CONSTITUTION:This head slider consists of the slider body, the surface of which opposite to the recording medium is worked as a fluid floating surface and a transducer provided to at least either of the front or rear end face of the slider body relating to the moving direction of the recording medium. Said slider body is the sintered body having the basic compsn. of 10-40vol% SiC and the balance Al2O3. The SiC has the function to improve the fit to the recording medium and lubricity and to improve the heat dissipation property of the slider by increasing the heat conductivity of the sintered body up to 0.05-0.10cal/cm.sec. deg.C; in addition, the SiC permits the easy precision working at the time of manufacturing the slider. Chipping is liable to arise in the corner part of the slider at the time of the precision working as compared to ferrite and the effect of improving the sliding lubricity is not admitted as compared to the sintered material of the Al2O3 alone if the content of SiC is <10vol%. Sinterability is poor if the content exceeds 40vol%.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic head slider for recording and reproduction (hereinafter referred to as a recording head slider) in computers, audio equipment, VTRs, etc., and particularly to a thin film recording head slider.

(Prior Art and Problems) In general, as substrates for electrical equipment, polycrystalline Ni-Zn ferrite, Mn-Zn ferrite, single-crystal Mn-Z
A material made of ferrite such as n-ferrite or high hardness permalloy is used.

However, in the conventional recording head slider, from the viewpoint of sliding lubricity with the magnetic recording medium, etc.

Ferrite type materials were preferred.

Incidentally, in recent years, recording heads have been made thinner at a rapid pace in order to achieve higher recording densities, smaller sizes, and the like. Under such circumstances, the characteristics of the recording head slider are as follows:
In addition to sliding lubricity (compatibility with recording media) and wear resistance (durability of magnetic heads) during use, precision workability and easy workability (machinability) are required during production. The slider is wear resistant.

It has become clear that it is insufficient in terms of precision machinability.

Therefore, in recent years, various materials have been proposed for the recording head slider, and examples of those that have been put into practical use include Al2.
There is an O3-TiC type (Japanese Patent Application Laid-Open No. 55-16306
No. 05). However, this A j! 203T i
Even if it is a C-type slider.

While it has superior wear resistance and machinability compared to ferrite-based materials, it has the disadvantage of poor sliding lubricity and increased wear on the recording medium.

(Means for Solving Problems) In view of the problems of the prior art, it is an object of the present invention to provide excellent durability during use and compatibility with recording media, extremely little deterioration of recording characteristics over time, and ease of production. An object of the present invention is to provide a recording head slider and a recording head slider substrate that have improved machinability during processing.

The recording head slider of the present invention includes a slider body whose surface facing the recording medium is a fluid floating surface, and a transducer biased toward at least one of the front and rear end surfaces of the slider body in the traveling direction of the recording medium. The slider body consists of;

The sintered body is characterized by having a basic composition of 10 to 40% by volume of 5iC and the balance Al2O3.

Further, the recording head slider substrate of the present invention is a recording head slider substrate for forming a slider by cutting a surface on which a plurality of transducers are to be formed and cutting a corresponding portion of each transducer. te;5iCIO~40
It is characterized by being a sintered body having a basic composition of volume % and balance A1□03.

In the present invention, a slider refers to a final product that is attached as is to a head holder for a disk drive, and a slider substrate refers to an intermediate product before being cut into individual sliders. in this case.

The slider substrate as an intermediate product may be one with or without a transducer attached, and may also include a slider substrate that is not precisely machined as long as the shape of the slider substrate is roughly maintained.

(Preferred Embodiment) The transducer according to the present invention preferably includes a thin film conversion circuit, and is provided on the end surface of the slider body, preferably on the rear end surface with respect to the moving direction of the recording medium.

In manufacturing the recording head slider, a plate-shaped intermediate product is prepared as a slider substrate, and this intermediate product is made up of a number of slider bodies arranged continuously, and generally consists of individual slider body pieces. The transducer is installed just before the cutout. The individual slider body pieces are cut out from the slider substrate (slider array) in order to be separated from each other to obtain a main surface serving as a fluid floating surface. This major surface is located perpendicular to the transducer mounting surface of the substrate. In addition, in any of these stages, 4! High precision machinability is required.

A recording head slider is generally manufactured through the following steps.

The sintered plate is machined at each step.

The surface is finished to the required precision. A thin film conversion circuit is provided on one of the flat surfaces of the sintered plate using a known thin film forming technique, forming a lattice array of a large number of sliders to be cut out. The slider is arranged in a manner such that it overlaps in the thickness direction of the slider. As mentioned above, this intermediate product is generally called a magnetic head slider substrate. A fluid (usually air) air bearing surface is attached to the recording medium (e.g. a disk)
is formed on the main surface of the slider body, facing the surface of the slider body. This air bearing surface is used as a positive pressure and/or negative pressure forming surface. Typically, a pair of positive pressure forming surfaces are located along opposite sides of the main surface.

The negative pressure forming surface is preferably located along the center of the main surface and between the pair of positive pressure forming surfaces.

One embodiment of the slider has a pair of positive pressure forming surfaces 12 located on both sides of a groove 11, as shown in FIG. The positive pressure forming surface 12 generally has an inclined region 13,
When the recording medium moves in the direction of the arrow, this inclined region I3 functions as a guide portion that introduces air into the positive pressure forming surface 12. Other aspects of the slider include, as shown in FIG.
A groove 1 that has a negative pressure forming surface 12'' and is open at the front end and closed at the rear end in the direction of air travel (direction of movement of the recording medium).
There is one in which negative pressure is created by the In forming such grooves, extremely high-precision finishing workability is required, and it is also required that chipping hardly occur. Similarly, high precision machinability is also required.

The slider body or slider substrate (hereinafter referred to as
This is referred to as the slider body. ) consists of a sintered body with a specific basic composition. That is, the basic composition of the sintered body is A J220 a-5 IC ceramic,
Contains 10 to 40% by volume of SiC, and the remainder is essentially Af!
Consists of 203.

SiC in the present invention not only improves compatibility with the recording medium and HJ lubricity, but also increases the thermal conductivity of the sintered body by 0.05-
0.10 cal/emsec, "c" to provide a function that improves the heat dissipation of the slider. This heat dissipation characteristic is required to dissipate the heat generated by the transducer that operates at high frequency. It also has the effect of making precision machining easier when manufacturing the slider.When the SiC content is less than 10% by volume, the corners of the slider (for example, grooves) are more easily processed than ferrite. Chipping is likely to occur on the edges), and compared to the sintered material of Aj!203, there is not much improvement in sliding lubricity.

Moreover, if it exceeds 40% by volume, sinterability will deteriorate.

Many pores are observed. Therefore, it is necessary to increase the sintering temperature, and when this sintering temperature becomes high (for example, about 1900° C. or higher), AJ! 203 crystal grains grow, and chipping is likely to occur at the corners of the slider.

Therefore, the content of SiC needs to be 10 to 40% by volume of the basic composition.

Preferably it is 15 to 35% by volume (remainder Aj!203). In the base composition, Aj2203 is typically at least 60% by volume.

In addition, along with the basic composition, MgO, Y2O3゜Z r
Sintering aids such as O, CaO, E r O, Cr 20 a may be added in an amount of 0.2 to 10 parts by weight per basic composition 1 (10 parts by weight).
It is possible to improve the sinterability of the C material, make the crystal grains finer, and further improve the precision workability of the slider. In this case, if the content of the sintering aid is less than ' 4 -. Addition of more than 1 part of 1 Off significantly reduces the hardness and strength of the slider, and also impairs dimensional accuracy.

In the slider body of the present invention, SiC in the sintered body may be either α-type or β-type as a powder raw material, and whiskers may also be used. Also, among the sintering aids, Z r
As a powder raw material for O2, there are two types: unstabilized powder that does not contain a stabilizer, and powder partially stabilized or stabilized with a stabilizer such as Y2O3°M g O, Cr 203 or CaO.

Compactness can be achieved using either powder. However, when using unstabilized Z r O2 powder, the purity is 99.
It is preferable that the content is 9% or more and the average particle size is 0.1 μm or less, and the final crystals are present in a tetragonal or cubic state. As a result, a two-structure improvement effect can be obtained, and a high-strength sintered body with fine, uniform, and dense crystal grains and no pores can be obtained, which improves compatibility with the recording medium and improves RF! Dynamic lubricity and wear resistance can be improved, and machinability can also be improved. On the other hand, 9-partially stabilized or stabilized Zr
When using O2 powder, use a ZrO2 raw material containing 7 to 15 mol% stabilizer (especially preferably Y20a), with impurities of 0°1% or less and an average particle size of 0.3μm or less. 9. The best effect can be obtained in terms of tissue improvement effect and strength improvement effect.

From the viewpoint of precision workability, the sintered body of the slider body of the present invention preferably has an average grain size of 2 μm or less, more preferably 1.5 μm or less.

If the average crystal grain size is coarser than 2 μm, chipping tends to occur and the smoothness and two-sided roughness of the machined surface decreases, which is not preferable. As for SiC, its particle size is 2 μm, more preferably 1 μm, and optimally 0.5 μm in order not to reduce toughness.

By specifying one grain size in this way, it is possible to suppress the occurrence of chipping that affects the quality of the slider. Further, the relative theoretical density of the sintered body is preferably 98% or more, more preferably 99% or more. Density, along with crystal grain size, greatly affects machining accuracy and also affects sliding characteristics with the recording medium. In addition, the transducer mounting surface is
It is preferable to make the surface as flat as possible and to make it non-porous. The coefficient of thermal expansion of the sintered body is approximately 8 X to'/'C (room temperature to 500 degrees Celsius), and the matching of thin film conversion circuit layers such as permalloy is also good, and even when the insulating layer or protective layer arrives. Does not cause peeling. Further, the electrical resistance of this sintered body is approximately 106 Ω-cm.

Since it is relatively small, it is advantageous when forming a thin film by sputtering or the like.

The sintered body related to the slider body and the like of the present invention can be manufactured, for example, as follows. first.

Mix raw materials of a specified purity to achieve a specified composition.

After mixing (and grinding), shaping and sintering.

It is usually obtained by pressure sintering, such as hot pressing (HP) or hot isostatic pressing (HIP).

Sintering is preferably carried out at a pressure of 150 kg ('/
Temperature 1700-1900℃ at cj or higher; in HIP method, temperature 1500-1700 at pressure 100kgf'/c- or higher
Can be done at ℃. In the case of HIP method, relative theoretical density 9
It is preferable to pre-sinter to about 4%. What is the sintering atmosphere?

A non-oxidizing atmosphere such as an inert gas may be used. The sintering time is appropriately selected until a predetermined density is reached, but a short time (0.5 hours or more is generally required).

1 to 3 showing examples of the slider of the present invention, 1 is a slider body, 2 is a thin film transducer,
3 is a magnetic layer, 4 is a conductive coil.

5 is a gap, 6 is an insulating layer, 7 is a protective layer, 8 is a fluid floating surface, and 9 is a magnetic pole tip.

(Effect of the invention) The slider according to the present invention exhibits excellent characteristics.

In other words, its wear resistance is maintained at almost the same level as that of the A1203T I C series slider (which has a high level of wear resistance among conventional sliders), and the tank dynamic lubricity and lead output characteristics are A j! 2
03-Ti It is possible to achieve a dramatic improvement over the iC-based slider. These features maintain the durability of the slider itself during use, while also preventing damage to the recording medium, which is a mating member, thereby increasing its durability.

Furthermore, the slider substrate according to the present invention has excellent precision machinability during production compared to conventional ferrite-based or A J 203-T i C-based ones, and is particularly suitable for thin-film magnetic head sliders. . Precision machinability requires prevention of chipping at corners during groove machining and ease of machining. In particular, in the case of a negative pressure slider, it is necessary to machine a groove with one end closed, which is generally difficult. However, the slider substrate of the present invention enables processing with a predetermined accuracy and can be processed easily. These features have great effects in mass production.

(Example) The present invention will be explained below based on examples.

(1) Manufacture of magnetic head slider As a composition of magnetic head slider.

Purity 99.9wt% Average particle size 0. A 1 of F1am
20a Purity 98.0wt% S with average particle size 0.4μm
iC purity 99. Ovt% Zr with average particle size 0.5μm
O2.

　g　O using each powder.

A combination: 5iC20% by volume - Al2O380 volume 96 total 10
Based on 0 parts by weight.

0.5 parts by weight of MgO Blend B: Based on a total of 100 parts by weight of S i C2'0% by volume - 96% by volume of Al2O380.

They were mixed to have a composition of 0.5 parts by weight of Mg and 1 ffi parts of Zr, and wet-mixed and pulverized for 20 hours using a rubber-lined ball mill.

Next, the above-mentioned sintering powder was filled into a carbon mold, and heated at 150 kg/cj in an argon atmosphere.
After holding at each temperature of 0° C. and 1800° C. for 1 hour, the pressure was reduced and allowed to cool to obtain a sintered body with dimensions of 50×50×5.5 (mm).

As a comparative example, the physical properties of the sintered bodies A and B related to the slider body etc. are compared with that of the conventional 70A I! 203-30Tic (
The results are shown in Table 1 along with the values of % by weight).

Table 1 *Aj! 203 and SiC.

(2) Evaluation test of magnetic slider (2,1)
) Precision machinability The sintered body obtained in (1) above was cut with a diamond cutting wheel, and fine chipping was observed at the corners. As a comparative example, a conventional ferrite material (Mn-
Zn polycrystalline ferrite: Mn032%, Zn015
weight; %, Fe20353 weight 2%) and previous weight 0A j
! A 2033OT t C-based sintered body was used. This chipping test is 1 width 0.28101 and diameter 52a+
It was carried out using a +n resinoid grinding wheel (cubic cutter with 30 μm diamond grains) with a cutting depth of 0.311+ m and a feed rate HA of 5 mm/sec. The results are shown in Table 2.

If the chipping depth does not exceed 2 μm, it will not substantially affect the slider quality and will maintain a satisfactory quality, whereas large chippings, such as in ferrite, will result in quality degradation.

Table 2 As is clear from the above Table 2, sintered body A according to the present invention
, B is much superior to ferrite, and A1□
There is no inferiority in precision machinability when compared with OaTiC. Therefore, it is suitable as a slider for a thin film magnetic head which requires a high degree of precision machinability.

(2,2) Wear resistance test The sintered bodies A and B according to the present invention were made into a rectangular parallelepiped with dimensions of 2 x 4 x 20 (■) using a diamond grinder, and a pin with an acute blade-like body at the lower end was prepared. did. on the other hand.

With ferrite, outer diameter 45 x inner diameter 10 x thickness 10 (f
Fabricate a donut-shaped plate (disc) of
A so-called pin-disk type wear test was conducted by bringing the cutting edge of a pin into contact with the surface of a rotating disk.

As a comparative example, ferrite and Al2O were used in the same manner as above.
3-TiC pins were used. The results are shown in Table 3.

Table 3 As is clear from Table 3, 1. Sintered bodies A and B according to the present invention
is A f! The amount of pin wear was as low as that of 20 a TiC, which means that the slider of the present invention has excellent wear resistance and long life. In addition, when looking at the amount of disk wear, although it is slightly inferior to that of ferrite, it is only about 1/3 that of A,77□03-TiC, which means that the slider of the present invention has a high resistance to recording media. This means that it has excellent sliding lubricity.

(2, 3> Read output characteristics When using the sintered body according to the present invention, the dimensions are 3X3X15 (m+n
) was precision machined, the corners were chamfered, and a shoe shine test was performed.

We investigated the decrease in read output.

The conditions for this shoe shine test are as follows: ・Tape: I B M Cr 02 tape.

・550g of tape-covered crab.

・Tape speed: 1.9m/see (75i
ps)・1 pass: 1 m.

-Test machine: TD-1502 (manufactured by NEC ■) The results are shown in FIG. As a comparative example, ferrite-based and A11203-TiC-based sintered bodies were used in the same manner as described above, and the results are also shown.

As is clear from FIG. 4, the read output of the slider according to the present invention was significantly less reduced than that of the comparative example.

(2,4) Comprehensive evaluation In Figure 5, there are three material properties required for a magnetic head slider: wear resistance of the recording medium (tape);
The read output characteristics of the recording medium and the wear resistance of the slider itself are compared and shown. Here, regarding wear resistance, the test conditions were a load of 0.95 kg and a sliding speed of 191.
It was measured at 7m/win. Note that each test was conducted using a magnetic recording tape and a slider (the corner of which comes into sliding contact adjacent to the running tape).

Note that it is generally understood to be indicative of slider characteristics associated with other magnetic recording media such as recording disks as well.

As is clear from FIG. 5, the A11203-SiC based slider of the present invention is different from the conventional ferrite based slider or A! !
The drawbacks of the 20a-T t C-based slider are eliminated. That is, A, e 20 a-T
Tape wear and output reduction are significantly suppressed compared to IC-based sliders, and wear of the slider itself is significantly suppressed compared to ferrite-based sliders. In other words, the characteristics of the great invention slider are ferritic and A1
This slider eliminates the drawbacks of the 203 TiC slider and is the most suitable slider.

[Brief explanation of drawings]

1 and 2 are perspective views showing a specific example of a magnetic head slider according to the present invention. 3(a) and 3(b) are diagrams showing a specific example of a thin film transducer according to the present invention, in which FIG. 3(a) is a front view, and FIG. 3(b) is a bb-b Enlarged cross-sectional view. FIG. 4 is a graph showing the results of a shoe shine test for an embodiment of the present invention and a comparative example, and FIG. 5 is a diagram showing a comprehensive evaluation of the magnetic head slider for an embodiment of the present invention and a comparative example. represents. 1...Slider body, 2...Transducer. Fig. 1 No. 3 Σ 1--b to b 5th slider wear () 7m1 Procedural Neighborhood Official Letter (self-motivated) September 30, 1986

Claims (2)

[Claims] (1) Consisting of a slider body whose surface facing the recording medium is a fluid floating surface, and a transducer provided on at least one of the front and rear end surfaces of the slider body in the moving direction of the recording medium, the slider body is a sintered body having a basic composition of 10 to 40% by volume of SiC and the balance Al_2O_3. (2) A recording head slider substrate having a surface on which a plurality of transducers are to be formed, and for constructing a slider by cutting a portion corresponding to the formation of each transducer, comprising 10 to 40% by volume of SiC and the remainder Al_2O_3. A recording head slider substrate characterized in that it is a sintered body having a basic composition.