JPH0296913A - Manufacture of magnetic head slider - Google Patents

Abstract

PURPOSE:To prevent the generation of grain omission due to the growth of a microcrack by using a grinding stone of a prescribed grain side at a prescribed peripheral speed for the cutting tool of a slider block. CONSTITUTION:Plural sliders are manufactured by cutting the slider block. In such manufacturing, the grinding stone at a grain size number 1,000 to 3,000 is used for the cutting tool of the slider block, the grinding stone is set at a peripheral speed 3,000 to 10,000m/min, and the block is cut. In such a way, the cut surface of the slider block is finished to a mirror surface having surface roughness at <=1.0mum.Rmax. Consequently, the generation of the microcrack due to the cutting is suppressed, the grain omission due to the growth of the microcrack is prevented, and the grain omission quantity after manufacturing can be drastically reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a slider for a magnetic head employed in a floating magnetic head for recording and reproducing data on and from a magnetic disk.

[Prior Art] Conventionally, monolithic type heads that use sintered ferrite such as Mn-Zn ferrite for the head core and slider have been widely used as floating magnetic heads for recording and reproducing information on magnetic disks. .

The manufacturing method of this monolithic type magnetic head will be briefly explained below. First, a material block made of sintered ferrite such as Mn-Zn ferrite is cut by machining, and a slider having a plate shape of ≦IL is cut into a predetermined shape. Tsuku and
A head core block having a substantially U-shaped cross section is molded, and then the head core block is joined to one side of the slider block by a crow. Next, the head core block is cut out at predetermined intervals along the joint surface with the slider block to form a plurality of hemlock cores with a predetermined core width, and after this, the surface of the slider block facing the rigid disk is made to have floating properties. A large number of negative pressure grooves are machined along the joining direction of each head core. After lapping the surface of the slider block to improve its 11 degrees, the slider block is sliced at equal pitches in a direction perpendicular to the joint surface of each core using a grindstone with a grain size of about 400 to 800. Get a slider. A plurality of monolithic magnetic heads are manufactured at the same time by chamfering the surface of each slider and the edge of the head core in a predetermined manner.

[Problems to be Solved by the Invention] Incidentally, in the conventional magnetic head manufactured in this manner, the slider is manufactured from sintered ferrite, etc., which is made from powder like the helad core, so the surface layer of the slider is There was a drawback that the particles were easily shed. If these fallen particles adhere to a magnetic disk, which is a magnetic storage medium, a so-called head crash occurs in which the fallen particles are caught in the gap between the magnetic head and the magnetic disk, destroying the magnetic layer on the disk surface. Head crashes occur more frequently as the flying height of the magnetic head decreases due to narrower tracks and higher density recording, and a solution to this problem has been strongly desired.

The present invention was made against this background, and an object of the present invention is to provide a method for manufacturing a slig for a magnetic head, which can prevent shedding of grains on the surface layer of a slider.

[Means for Solving the Problems] In order to solve the above problems, the inventors first conducted various tests to determine the mechanism by which shedding occurs in the surface layer of the slider.
The occurrence of grain shedding on the surface of the slider is due to defects existing in the slider block growing into microcracks during subsequent processing, and the knowledge that these microcracks grow due to residual stress and cause grain shedding. I got it.

Therefore, the inventors considered that the incidence of grain shedding could be reduced by polishing the slider surface to ensure a mirror surface even in the microscopic range and removing microcracks. In order to clarify the degree of wear, we investigated the incidence of shedding when the surface roughness of the slider surface was varied as shown in Figure 2, and found that at least the slider surface had a surface roughness of 1 μm-Rmax or less. It was found that grain shedding can be sufficiently suppressed if the grain is finished to a mirror surface. In addition, the occurrence rate of shedding is 1 mm of the slider surface.
If one or more shed particles occur per 2, the probability is 1.
00%, for example, surface area 100mff1'
When 80 particles fall off from the slider, the shedding occurrence rate is 80%. In order to use it as a sliver for a magnetic head, it is required that the shedding occurrence rate in a high humidity test is 20% or less, and in order to sufficiently guarantee reliability, it is desirable that it be 5% or less.

Here, the surface of the slider manufactured by the above-mentioned method has a surface roughness of 1μs by lapping before cutting, except for the cut surface when it is separated from the slider block.
Therefore, in order to reduce the incidence of shedding, the cutting process from the slider block should be performed under conditions such that the surface roughness of the cut surface is 1 μm or less, that is, the cut surface It is best to carry out the process under conditions that do not allow microcracks to occur. Therefore, in order to find such conditions, we conducted various cutting tests while changing the grain size of the grinding wheel used for cutting, the circumferential speed of the grinding wheel, the feed speed of the slider block, and the temperature of the grinding fluid. tb lo o o ~ 3000 No. grindstone is used for cutting - [Used as a tool, the circumferential speed of this whetstone is 3000 ~ I
If you cut the slider block by setting it to 000n/min, the cut surface of the slider will be Fil +Q = 1μm - R
It has been found that it is possible to improve the mirror surface below max, thereby drastically reducing the incidence of grain shedding.

[Operation 1] If the slider block is cut under the above conditions, the cut surface of the slider is finished to a mirror surface with a surface roughness of 1 μm-Rmax or less, and the occurrence of microcracks is suppressed, so the occurrence of grain shedding is drastically reduced.

[Example] Hereinafter, an example in which the present invention is applied to manufacturing a monolithic type magnetic head will be described with reference to FIGS. 1(a) to 1(g).

First, the manufacturing process of the magnetic head in this embodiment will be described in detail. As shown in FIG. 1(a), in manufacturing the magnetic head of this embodiment, a flat plate-shaped material block 1 is used as a raw material. This material block l is made of sintered ferrite, and the manufacturing procedure is briefly explained.
, O, , Mn 304, MnC0-1ZnO) to the molecular component ratio of ferrite, and by mechanically mixing and heating at 900 to 1200°C, the following reaction occurs to form ferrite. generate.

MnO + F e, o * → MnF elO.

Z no + Fego 3 → Z nFeto 4 Next, the generated ferrite powder is placed in a suitable flexible container and molded into a desired shape by applying static pressure, and the molded green compact is then sintered. By sintering, a solid phase reaction occurs to produce sintered ferrite in a desired shape. In addition, when hot isostatic pressing is performed during molding, higher density ferrite can be obtained. Furthermore, the method for producing ferrite powder may be a liquid phase reaction, or a hot press method may be used to perform molding and sintering at the same time.

In order to manufacture a magnetic head from the material block 1 manufactured in this way, first, as shown in FIG. Then, as shown in FIG. 1(C), a groove 3a is formed on the cut surface of the core block 3. Thereafter, the cut surfaces of the slider block 2 and core block 3 are polished and a gear knob is formed. 5 for
A film of iO7 or the like is formed by sputtering. And the first
As shown in Figure (d), the cut surface of the slider block 2 is brought into contact with the cut surface of the core block 3, and these are joined by a glass material 4. Note that this glass material 4 is a so-called low melting point glass, which has a much lower melting point than ordinary glass materials (for example, Sin, etc.), and its bonding temperature is 300 to 500°C.

After the slider block 2 and the core block 3 are joined, the lower surfaces of these two parts are ground together to form a predetermined thickness, and then the core block 3 is assembled as shown in FIG. 1(e).
After shaping the head core 5 to a predetermined width, the first
As shown in Figure (f), on the top surface of the slider block 2,
Negative pressure grooves 6 for floating the magnetic head above the rigid disk are formed.

After that, the surface of the slider block 2 is lapped, and then the slider block 2 is sequentially sliced at predetermined intervals along the joint surface with the head core 5 as shown in FIG. After that, the surfaces of the rad core 5 and the slider 7 are subjected to a predetermined chamfering process, and the manufacture of the slider 7 is completed.

In the manufacturing process of the magnetic head described below, when dividing the slider block 2 into a plurality of sliders 7, a grindstone with a grain size of 2000 is used as a cutting tool, and the circumferential speed of this grindstone is set to 5000 m/1 inch. When the cut surface of the slider 7 was cut, the surface roughness was 0.2 μs-R.
+max, or less, and the slider 7 after manufacturing the magnetic head
Grain shedding from the surface layer hardly occurred, and the shedding occurrence rate showed an extremely low value of 2% or less. This is because the generation of microcracks is suppressed during the cutting process when dividing the slider block 2 into the sliders 7.
This is thought to be because the occurrence of grain shedding due to the growth of microcracks on the cut surface was drastically reduced.

Although the above embodiments are particularly directed to a monolithic type magnetic head made from sintered ferrite, the present invention is not limited thereto, and can be applied, for example, to the manufacture of a ceramic slider used in a thin-film magnetic head. Naturally, this is also applied to composite type magnetism, and -3-C is also naturally applied when ceramics are used as the material of the slider.

Furthermore, according to JIS-R6001, the average particle size of grindstones with a grain size of 1000 to 3000 is 1.
Although it is supposed to be in the range of 8 to 4.7 .mu.m, in reality, it is considered to be generally appropriate if the average particle diameter is in the range of 20 to 2 .mu.m.

[Effects of the Invention] As explained above, the present invention uses a grindstone with a grain size of too to 3000 as a cutting tool for a slider block, and sets the circumferential speed of this grindstone to 3000 to 10000 s/sin.
By cutting the slider block with the setting, the cut surface of the slider block has a surface roughness of 1.0μs-Rmax,
Since it is finished to the following mirror surface and suppresses the occurrence of microcracks that occur during cutting, the occurrence of grain shedding due to the growth of microcracks on the cut surface is prevented, and the amount of grains shed from the slider surface after manufacturing is drastically reduced. It has this excellent effect.

[Brief explanation of the drawing]

Figures 1(a) to 1(g) are diagrams showing the manufacturing procedure of a monolithic type magnetic head in an embodiment of the present invention, and Figure 2 shows the relationship between the surface roughness of the slider surface and the incidence of grain shedding. FIG. 2...Slider block, 7...Slider.

Claims (1)

[Claims] Slider to be manufactured In a method for manufacturing a slider for a magnetic head in which a plurality of sliders are obtained by cutting a slider block that has been subjected to multiple predetermined machining processes in parallel, a grindstone with a grain size of 1000 to 3000 is used as a cutting tool for the slider block. Using a grinding wheel, the circumferential speed of
/min. 1. A method of manufacturing a slider for a magnetic head, characterized in that the slider block is cut by setting the slider block to .