JPH02281485A - Floating type magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To relieve sticking and to prolong the life of CSS (contact start-stop) by specifying the roughness of the surface facing a magnetic recording medium and undulating the parts where the height between the peaks and valleys changes sharply so as to extend along the grain boundaries of crystal. CONSTITUTION:The magnetic head 1 consists of a slider 2 made of a polycrystalline magnetic material and a chip 3 made of a polycrystalline or single crystal magnetic material. The chip 3 is fixed into a slit 6 formed on one surface 4 of the two bearing surfaces 4, 5 of the slider 2. The surfaces of the bearing surfaces 4, 5 are so treated as to have the specific surface roughness. Namely, the surfaces are undulated in the following manner: The difference in the depth between the peaks and the valleys is 50 to 200Angstrom in average; the repeating pitch of the peaks and the valleys is 5 to 50mum in average; and the parts where the height between the peaks and the valleys changes sharply extend along the grain boundaries of the crystals. The sticking of the head 1 and the disk is relieved and the CSS damage of the head is prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a floating magnetic head (hereinafter sometimes simply referred to as a head) and a method for manufacturing the same, and particularly relates to a floating magnetic head for small hard disks using a thin film medium. The present invention relates to a type magnetic head and a manufacturing method thereof.

[Prior Art] Currently, the mainstream of hard disks as magnetic recording media is one in which oxide magnetic powder is coated on an aluminum alloy substrate.
Hard disks in which a magnetic material is adhered to a substrate using a sputtering method are increasingly being used. The magnetic disk device is
Using the above-mentioned plating and sputtering methods, disks have become smaller and more convenient, and the motors that drive the disks have become thinner and have lower torque.

[Problem M to be solved by the invention] The surface of the disk made by the plating method and the sputtering method described above is finished with better surface precision than the conventional coating method, and it is possible to overcoat the surface with a lubricant. Therefore, the sticking phenomenon that occurs between the head and the disk surface, which has not been considered a problem in the past, has become a problem. In other words, when 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 adhesive force between the head and the disk becomes excessively strong, C5S (contact start and stop) will shorten the life of the device.
Life expectancy will be shortened. In particular, the problem is becoming more serious in devices that combine several disks.

In order to alleviate this sticking phenomenon, various attempts have been made to process the surface of the head facing the disk so that it is roughened to some extent, but none of them have been sufficiently effective.

[Means for Solving the Problems] In order to solve the above problems, claim (1) provides a slider made of a polycrystalline magnetic material, and a head chip insertion groove embedded in a head chip insertion groove formed at the rear end of the slider. In the floating magnetic head, the surface facing the magnetic recording medium has a difference in depth between peaks and valleys of 50 to 2 on average.
00A plane, the pitch of repeating peaks and valleys is 5 to 20 μm on average, and the part where the height between the peaks and valleys changes rapidly extends along the grain boundaries of the crystal. To provide a floating type magnetic head characterized in that it has an uneven surface.

The present invention also provides a floating magnetic head according to claim (2), characterized in that the surface facing the magnetic recording medium is mainly composed of a convex portion having a flat top surface and a concave flat bottom surface. provide.

Furthermore, in claim (3), the magnetic head is finished so that the average amplitude of the waviness of the entire surface of the disk facing surface or a portion thereof is 50 to 300 A as measured by a roughness curve using a stylus type roughness meter. A floating magnetic head according to claim 4, characterized in that the surface facing the magnetic recording medium is treated to a predetermined surface roughness by using a reverse sputtering method. Provided is a manufacturing method for a floating magnetic head according to claim (4), wherein the manufacturing method is M1, and in claim (5), the process-affected layer is removed and the surface is cleaned during the reverse sputtering process. ,
The floating magnetic head according to claim (4) or (5), wherein the part of the surface facing the magnetic recording medium that is not to be processed is covered with a mask, and only the part to be processed that is exposed from the mask is processed. Provides a manufacturing method.

Further, in claim (7), there is provided a method for manufacturing a floating magnetic head according to claim (6), wherein the mask is removed during the reverse sputtering, and a step is formed between the portion covered with the mask and the exposed portion. do.

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

FIG. 1 is a perspective view showing an example of a floating magnetic head comprising a slider made of polycrystalline magnetic material and a head chip embedded in a head chip insertion groove formed at the rear end of the slider. be. The magnetic head 1 consists of a slider 2 made of polycrystalline magnetic material and a tip 3 made of polycrystalline magnetic material or single crystal magnetic material. It is molded and fixed with glass or the like in the slit (UP)6 formed in the.

A detailed structure of an example of the chip 3 is shown in FIG.

In FIG. 2, sputtered films 22 and 23 are formed on the C-shaped core 10 and the square-shaped core 11. The C-shaped core 10 and the I-shaped core 11 are joined by glass or the like via a magnetic gap 12. This C-shaped core 10 and ■-shaped core 1
Joint surface with 1 (front gap and back gap)
As shown in FIG. 3, some of them form an alloy film 21 with high saturation magnetic flux density and high magnetic permeability. The core shown in FIG. 2.3 is wound with a wire in a predetermined turn on the chip 3 through the winding window.

In addition, as a magnetic alloy with high magnetic permeability, a Fe-Al1-5t alloy commonly called sendust is suitable. Particularly suitable Fe-Al-3t-based magnetic alloys include those containing Al2: 2 to 10%, Si: 3 to 16%, the remainder being substantially Fe, and AjZ: 4 to 8% by weight. , S
Particularly preferred is i: 6 to 11%, with the remainder being substantially Fe. Note that even if Ti and Ru are contained in an amount of 2% or less each, corrosion resistance and wear resistance can be improved, which is preferable. Further, the same effect can be obtained even if Cr is contained in an amount of 4% or less.

A polycrystalline magnetic ceramic material is suitably used as the constituent material of the chip 3, and Mn-Zn ferrite,
Ni--Zn ferrite and the like are preferred, and Mn--Zn ferrite is particularly preferred. A suitable composition of Mn-Zn ferrite is 25 to 37% MnO, Zn
08 to 23%, and Fe2es 51 to 57%. As the constituent material of the chip 3, it is also suitable to use a single crystal material of Mn-Zn ferrite.

The constituent material of the slider 2 in FIG. 1 is Mn-Z.
Polycrystalline materials such as n-ferrite and Ni-Zn ferrite are preferred.

In the present invention, the surface of the bearing surface 4.5 is treated to have a specific surface roughness.3 In the present invention, all of these bearing surfaces 4.5 may be treated to have the specific surface roughness. However, for example, only the hatched area in FIG. 2 may be processed. FIG. 4 is a sectional view schematically showing the bearing surface of the head according to the embodiment of claims (1) and (2). . As shown in the figure, peaks 28 and valleys 29 appear alternately on the bearing surface,
Moreover, between the mountain 28 and the valley 29 there is a part (cliff) 30 where the height changes rapidly. This cliff 30 part is crystal 31
~41 grain boundaries 42. Mountain 28 and valley 2
The average value of the difference d in depth from 9 is 50 to 200 A (preferably 70 to 170 A), and the pitch e of repetition of peaks and valleys is 5 to 20 μm (preferably 7 to 17 μm).

In this way, the peaks 28 and the valleys 29 have an appropriate level difference and are repeated at an appropriate pitch, thereby preventing or alleviating the sticking phenomenon between the head and the disk. Furthermore, it is believed that the cliff 30 extends along the grain boundaries 42 to prevent C5S damage to the disk. That is, since the part of the cliff 30 extends along the grain boundary, the part of the cliff 30 has substantially the same strength as a single crystal grain, and the part of the cliff 30
Even if the 0 edge portion repeatedly collides with the disk (for example, tens of thousands of times or more), no chips or the like will occur. It is also presumed that since there are no sharp edges or sharp particles caused by chipping, no damage is caused to the disk.

Further, in the present invention, since the bearing surface is mainly composed of a flat convex top portion and a flat concave valley surface, when the head lands on the disk surface or conversely takes off from the disk surface, the bearing surface is The phenomenon of scratching is also reliably avoided, and it is believed that this also improves the C3S characteristics.

Static friction coefficient μm between the disk and head is 1.0 or less,
Desirably, it can be kept 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, measuring the force (torque) required to start the rotation of the magnetic head, and calculating the It was converted into a coefficient.

To construct such a bearing surface, a reverse sputtering method, which will be described later, may be employed. In addition, when processing the bearing surface by the reverse sputtering method, a floating magnetic head that has been finished so that the amplitude of the waviness of the bearing surface or a part thereof is 50 to 30 QA as measured by a roughness curved surface using a stylus roughness meter. also achieves the object of the invention.

The reverse sputtering method is a method of processing the surface roughness of the disk-facing surface of a magnetic head by using a reverse sputtering state using a sputtering device.0Reverse sputtering is a method of processing the surface roughness of the surface facing the disk of a magnetic head using a reverse sputtering state using an inert gas, e.g. In an Ar (argon) gas atmosphere, a high voltage is applied to ionize the Ar gas, causing it to collide with the target (substrate) surface, and the target particles that fly out at that time adhere to other substrates to form a film. In contrast, in reverse sputtering, ionized inert gas collides with the surface of the magnetic head to remove atoms on the head surface. At this time, the material of the head is a polycrystalline material and is formed from small crystal grains. Each crystal grain that forms the head has a different surface orientation, and when ionized gas collides with it, the surface is removed, but the bonding energy of atoms differs in each crystal direction, and the surface is removed. Since the energy required to remove the grains differs, this removal process causes differences in the amount removed for each grain, resulting in the creation of minute height differences between each grain boundary. . Further, this processing is processing in an atomic state, and is a means that can control steps ranging from minute differences to relatively large steps depending on time. It should be noted that during the reverse sputtering process, the process-affected layer is removed and the surface is cleaned. Also,
At the time of reverse sputtering, unnecessary portions may be masked and only necessary portions may be subjected to reverse sputtering.

[Example] Example! Mn0 31 mol%, Zn0 16 mol%, Fe2O35
A magnetic head consisting of a slider made of a polycrystalline material consisting of 3 mol% and a core having the same composition as above is used, and the surface facing the disk is wet lapped using fine diamond abrasive grains. It was mirror finished to a roughness of 10 to 40A.

An R-F type sputtering device is used, the turntable size is φ42 cm, the input power is set to 0.5 kW, Ar is used as the gas, and the gas pressure is 0.44 to 0.5 kW.
It was set to 48Pa. FIG. 5 shows the relationship between reverse sputtering time and surface roughness. These relationships change depending on conditions such as the input power, the type of inert gas, the composition of several gases, and the gas pressure, but 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 amount of head surface removal at this time is also shown in FIG. 5, but by masking the head surface with a layer that is thicker than the removal amount, the masked head surface is not removed by reverse sputtering. The parts in the original state without the mask were removed by reverse sputtering, making it possible to create a head with partial contact with the disk as shown in FIG. During reverse sputtering,
By removing this mask, the step on the slider surface on the disk facing surface of the slider is increased, and the step on the other opposing surface is reduced, creating a step between these surfaces, and the slider surface directly contacts the disk. You can also prevent contact. Figure 6 shows the change in static friction force generated between the disk and the head when the height difference between the peaks and valleys of the head is changed.
Measurements are shown in relation to the number of repetitions of S. For those processed only with the conventional wet rubbing, the frictional force increases as the number of cssa turns increases, and the amount of increase changes significantly from about 10,000 times. On the other hand, the increase in frictional force is also small in the head having steps between peaks and valleys according to the present invention. (From this, it is thought that the rougher the step on the surface of the head facing the disk, the greater the effect. However, if the surface is too rough, it may cause damage to the head and disk. The upper limit is the difference in depth between peaks and valleys where no occurrence of .

Example 2 A mirror-finished floating head with a diameter of 10 to 40 A was used, and the floating magnetic head was placed on a turntable (diameter 4
2cm) at the specified position, and input power from 0.3 to
The disk facing surface of the floating magnetic head was surface-treated by changing the 1.0 kW% Ar gas pressure from 0.4 to 0.5 Pa and the reverse sputtering time from 10 to 60 minutes. As a result, the floating magnetic head according to the present invention obtained is as shown in FIG. In FIG. 1, the shaded area is the area that was surface treated by reverse sputtering, and the other areas were masked to prevent surface treatment during reverse sputtering. The surface roughness of the thus surface-treated portion was measured using a stylus roughness meter. An example of the roughness curve obtained as a result is shown in FIG. The roughness curve shows periodic undulations. The average wavelength λ of the undulations is determined by the continuous peaks L1L2, . L3...Take out L, measure the distance l between L + -L,
It was calculated from λ=J2/20. Note that the roughness curve was measured at 10 locations over a distance of 5 mm, and the average value of the 10 curves was taken as λ.

In addition, R max is 0.020 to 0.030 μm in both cases.
Met. When we measured the CSS characteristics of this floating magnetic head with various λs obtained as described above, a sputter disk, and a plating disk, we found that if the difference in depth between peaks and valleys is 50 to 300 A, the number of C5S increases. Even after 30,000 times or more, the static friction coefficient μm was maintained at 0.7 or less, and it was confirmed that neither spatter nor plated disks would crash. When λ becomes 30xlO'''3μm or more, the surface roughness Rmax becomes small and the coefficient of static friction μ becomes 0.7 or more, causing the disk to crash in less than 5,000 cycles, similar to a normal floating head, and λ=5X10 It has become clear that disk crashes occur in less than 10,000 cycles even when the value is less than -'μ.

Example 3.4, Comparative Example 1.2 In Example 1, the reverse sputtering time was set to 0 minutes (Comparative Example 1
), 10 minutes (Example 3), 20 minutes (Example 4), and 30 minutes (Comparative Example 2). The surface roughness curve of the obtained bearing surface is shown in FIG. The depth d and pitch e of the unevenness in these cases (definitions of d and e are as shown in FIG. 5) are as follows.

Incidentally, FIG. 9 shows a schematic diagram of a microscopic photograph of the surface of the bearing surface (treated surface) of Example 1.

A CSS test was conducted using the heads of Example 3.4 and Comparative Example 1.2.

The disk used in the C3S test was the following 3.5-inch hard disk.

Substrate Nialuminum base: Cr Magnetic layer: Co-Ni sputtered film Surface layer: C sputtered layer and fluororesin lubricant layer coated on the C layer surface (lubricant thickness approximately 10 to 30 layers) Disk surface roughness S: 400~aoo The disk drive conditions during the AC3S test are as follows.

Rotation speed: 3600 rpm Time for one rotation: 7 seconds Stop time between rotations + 3 seconds While performing this C5S test, the coefficient of static friction μ between the head and the disk was measured. The results are shown in the 10th column along with the number of C5S repetitions.
As shown in the figure.

The following is recognized from Figure 1O.

In Example 3.4, even after 100,000 CSS operations, 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 C3
With S, an abnormal "chirring" noise occurs when the head makes contact with the disk, and with C8S, which has been run 40,000 times, failures are sometimes observed when the disk starts rotating. In Comparative Example 2, the static friction coefficient μ
Although the damage is low, after 20,000 C5S cycles, damage to both the head and disk surfaces begins to occur.

CSSS Step Example 2 A test similar to Test Example 1 above was conducted except that the following plating disk was used.

Substrate Nialuminum base: N1-P Magnetic II! 2: Co-Ns surface layer: C and lubricant (same as test example 1) This C3S
The results of the test example are shown in FIG.

The same results as in Test Example 1 above are also observed in Figure 'fS11.

[Effect of the invention] As is clear from the above examples, claims (1) and (2)
), (3) heads have a small coefficient of static friction with the disk, and even after repeated C3S, both the disk and head surfaces are less likely to be scratched and have good durability.

According to claims (4), (5), (6), and (7), such a head can be manufactured.

As described above, the present invention makes it possible to reduce the friction that occurs between the disk and the magnetic head, making it possible to respond to smaller, lighter, and thinner disk mounting M using an inexpensive and stable method. It becomes like this.

Furthermore, according to the present invention, it is possible to reduce the friction that occurs between the sputter disk or the plating disk and the floating magnetic head, thereby extending the life of the C3S, thereby making the hard disk equipment smaller, lighter, and thinner. Be able to respond to

[Brief explanation of drawings]

Figure 1 is a perspective view of the floating magnetic head, Figures 2 and 3 are perspective views of the Herad chip, Figure 4 is a sectional view of the bearing surface, Figures 5, 6, 7, and 8. 10 and 11 are graphs showing measurement results, respectively, and FIG. 9 is a schematic plan view of the surface of the bearing surface. 28...Mountain, 29...Valley, 30...
Mugi, 31-41...crystal grain. Agent Patent Attorney Tsuyoshi Shigeno Fig. 1 Fig. 3 Magnetic head chip 6 slots Fig. 2 111 type core 12 gap Reverse sputtering time (minutes) Fig. 6 Fig. 7

Claims (7)

[Claims] (1) A floating magnetic head comprising a slider made of polycrystalline magnetic material and a head chip embedded in a head chip insertion groove formed at the rear end of the slider, which faces a magnetic recording medium. The surface is a surface in which the difference in depth between the peaks and valleys is 50 to 200 Å on average, the pitch of repeating the peaks and valleys is 5 to 20 μm on average, and the height between the peaks and valleys is 5 to 20 μm on average. A floating magnetic head characterized by having concavities and convexities that appear to extend along the grain boundaries of the crystal in areas where the rapid changes occur. (2) The floating magnetic head according to claim 1, wherein the surface facing the magnetic recording medium mainly consists of a convex portion having a flat top surface and a concave flat bottom surface. (3) A patent claim characterized in that the average amplitude of the waviness of the entire surface of the disk facing surface of the magnetic head or a portion thereof is 50 to 300 Å as measured by a roughness curve using a stylus roughness meter. A floating magnetic head according to item 1. (4) A method for manufacturing a floating magnetic head, characterized in that the surface facing the magnetic recording medium is treated to a predetermined surface roughness using a reverse sputtering method. (5) The method for manufacturing a floating magnetic head according to claim (4), characterized in that during the reverse sputtering process, the process-affected layer is removed and the surface is cleaned. (6) The method for manufacturing a floating magnetic head according to claim (4) or (5), wherein the part of the surface facing the magnetic recording medium that is not to be processed is covered with a mask, and only the part to be processed that is exposed from the mask is processed. . (7) The method for manufacturing a floating magnetic head according to claim (6), wherein the mask is removed during reverse sputtering, and a step is formed between the masked portion and the exposed portion.