JPH06282831A - Magnetic head - Google Patents

Abstract

PURPOSE:To achieve higher reliability by lapping a side of a head to hold a surface roughness Ra below a specified nm while the head undergoes a blending. CONSTITUTION:In the loading and unloading, it is desired that a magnetic head 1 is as parallel as possible in attitude with respect to a magnetic disc of the magnetic head 1 immediately before the magnetic head 1 begins to float over the magnetic disc. But the magnetic head may deviate, for example, even to an extent of 100mum or more because of working errors, assembling errors or the like. When this happens, traditionally with no lapping of sides 1b, 1c and 1d, the surfaces of the sides affect the disc to lower reliability. In this invention, the sides 1b, 1c and 1d are lapped to hold a surface roughness Ra, for example, below 3nm. Thus, even if the attitude of the head is inclined greatly because of assembling errors and working errors, a surface roughness RA also held smaller on the side of the magnetic head eliminates the lowering of the reliability of the head. The blending work of the head further achieves higher reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head mounted on a magnetic disk device.

[0002]

2. Description of the Related Art In recent years, magnetic disk devices have been widely used, and floating sliders are widely used in consideration of the durability of the magnetic disk surface. This slider is generally called a positive pressure slider, and is supported by a suspension made of a thin leaf spring and floats above the magnetic disk with a minute gap. Generally, a magnetic disk device employs a mechanism called CSS (contact start stop). Since the positive pressure slider is in contact with the magnetic disk when it is not operating, the magnetic head has a magnetic disk when starting and stopping rotation. As a result of sliding on the slider, and as a result, abrasion powder was generated between the slider and the disk, an adsorption phenomenon occurred in which the magnetic disk and the slider were stuck to each other even when the apparatus was started up and could not be rolled. Therefore, a load / unload mechanism has been devised in which the magnetic disk and the slider do not come into contact with each other even when not in operation. The load / unload mechanism will be described with reference to FIG. In FIG. 2, the left side is a side view of the disk device, and the right side is a plan view. Reference numeral 1 is a magnetic head, 2 is a magnetic disk, 3 is a suspension for supporting the magnetic head 1, 4 is a load bar for performing load / unload, and 5 is a load bar.
Is an arm for supporting the suspension 3. A side view of the load bar 4 is shown in FIG. The load bar 4 has a portion 4-H parallel to the magnetic disk 2 and a portion 4-K having an inclination. As shown in FIG. 2A, the magnetic disk 2 and the magnetic head 1 are in non-contact with each other during non-operation,
The magnetic head 1 is arranged on the outer side in the radial direction of the magnetic disk 2 and in a space apart from the plane on which the surface of the magnetic disk exists. From this state, after rotating the motor, the arm 5 supporting the suspension 3 is rotated to the disk side around the fulcrum of the arm 5 and the magnetic head 1 is moved to the magnetic disk 2 side. 4 slide in parallel section 4-H, and eventually slope 4
-K is reached and slides along the slope. Further arm 5
When is rotated, the lock is released from the load bar 4 supporting the suspension 3, the magnetic head 1 is displaced to the magnetic disk 2 side, and the magnetic head 1 floats above the magnetic disk 2 (see FIG. 2 (B ), (C)). On the other hand, when unloading the magnetic head 1 from the magnetic disk 2, when the power of the apparatus is turned off, the arm 5 rotates around the fulcrum of the arm 5 toward the outer circumference of the magnetic disk, and the suspension 3 moves to the load bar 4. The suspension 3 is caught on the inclined portion 4-K, the suspension 3 moves away from the magnetic disk 2 along the slope, and the magnetic head 1 can be unloaded from the magnetic disk 2 (see FIG. 2).
(D)). Then, the process returns to the initial state shown in FIG.

[0003]

As described above, by adopting the load / unload, the problems such as wear and adsorption due to CSS have been solved, but new problems have occurred. It is a variation in the relative attitude of the magnetic head with respect to the magnetic disk due to an assembly error. When the magnetic head is greatly tilted with respect to the magnetic disk,
When the magnetic head approaches the magnetic disk during unloading, the magnetic head and the magnetic disk come into contact with each other and the magnetic head damages the surface of the magnetic disk.

The present invention solves the above conventional problems, and an object of the present invention is to provide a magnetic head having improved reliability and in which the magnetic head and the magnetic disk do not come into contact with each other to damage the magnetic disk. is there.

[0005]

In order to achieve the above object, the present invention provides a surface roughness Ra by applying a lap along the side surface of the magnetic head in order to remove the roughness of the magnetic head surface.
Was set to 3 nm or less. In addition, curved surface processing was performed on the ridgeline between the air bearing surface and the side surface perpendicular to the air bearing surface.

[0006]

Therefore, according to the present invention, when the magnetic head approaches the magnetic disk and starts to fly, even if the magnetic head hits the magnetic disk, it does not damage the magnetic disk and reaches the flying.

[0007]

1 is a drawing of a magnetic head according to an embodiment of the present invention. FIG. 9 shows a conventional magnetic head. The outer edge of this conventional magnetic head is machined, and the air bearing surface is lapped using fine abrasive grains.
The irregularities on the surface generated during machining are removed. Although the magnetic head processing is finished here in the conventional process, the present invention is characterized in that the lapping process is also provided on the side surfaces (1b, 1c, 1d) perpendicular to the air bearing surface. The way to wrap is the same as before. Further, a process called blending is performed on the magnetic head after the ramp. The ridgeline that exists between the air bearing surface and the side surface that is perpendicular to the air bearing surface has a vertical cross section when it is the same as the conventional magnetic head. The disc had microscopic scratches, and if it happened continuously, it could eventually lead to a crash. Therefore, by making the ridge line round, the impact force can be softened even when the magnetic head comes into contact with the magnetic disk. FIG. 4 shows a schematic view of the blend processing machine. In FIG. 4, 6 is a stage of the main body, 7 is a wrapping tape for processing a magnetic head, and the surface of the wrapping tape contains abrasive grains and is located on the stage 6. Reference numeral 1 is a magnetic head, and 8 is a magnetic head mounting portion to which the magnetic head 1 is fixed with a double-sided tape or the like, and the material is an elastic body such as rubber. Magnetic head 1
Is attached to the magnetic head attachment portion 8 so that the air bearing surface of the magnetic head 1 faces downward, that is, toward the wrapping sheet. Reference numeral 9 is a weight and its mass is adjusted according to the processing amount. The weight 9 of the apparatus configured as described above is vertically vibrated. The vibration reaches the magnetic head 1 through the elastic body, and the magnetic head 1 vibrates according to the exciting force. At this time, since the lapping tape 7 for processing is located under the magnetic head 1, the magnetic head 1 is processed when the magnetic head 1 vibrates. The degree of reliability of the magnetic head thus formed is higher than that of the conventional magnetic head.

(1) Experiment of Effect of Surface Roughness Various test pieces made of the same material as the slider material of the magnetic head having a total length of 4 mm, a total width of 3 mm and a total height of 1 mm and different surface roughness are prepared. . In one test piece, the surface roughness was the same on all surfaces. In the experiment, MnZn Ferrite was used as the material. Each test piece is assembled to a suspension and a sliding test is performed on a rotating magnetic disk. At this time, the posture of the test piece is tilted with respect to the magnetic disk so that the posture is 60 μm in both the pitching direction and the rolling direction as shown in FIG. Ten
Is a test piece. An AE (acoustic emission) sensor is mounted on the arm to which the suspension is mounted in order to measure the level of contact between the test piece and the magnetic disk.
In this state, the test piece 10 was subjected to a sliding test on the magnetic disk, and various test pieces were used to measure the voltage value of the AE output. The result is shown in FIG. As can be seen from FIG. 8, the surface roughness R
The smaller a is, the smaller the AE output is. But,
Below 3 nm, the AE output remains low and almost constant. Therefore, to investigate the relationship between AE output and reliability,
The above-described experiments were conducted intermittently for two types of the surface roughness Ra of about 1 nm and about 100 nm, and the time until the crash was investigated. The results are summarized in Table 1 along with the AE output.

[0009]

[Table 1]

As can be seen from this table, those having a small surface roughness Ra have a small contact force and are unlikely to crash. On the other hand, those having a large surface roughness Ra have a large contact force and are apt to crash. In other words, it is the contact force between the test piece represented by the AE output voltage value and the magnetic disk that determines the crash arrival time, and the surface roughness that determines the contact force. The smaller the surface roughness, the smaller the contact force. Get smaller. Here, as a representative, only the surface roughness of about 1 nm is performed, but it is expected that almost the same results can be obtained for the surface roughness of 3 nm or less, which has almost the same AE output.

However, the surface roughness R on the air bearing surface of the magnetic head
Although it has been shown above that a is involved in reliability, whether or not the surface roughness Ra on the side surface is involved in reliability will be described with reference to FIG. When loading and unloading, it is ideal that the posture of the magnetic head with respect to the magnetic disk should be as close to parallel as possible just before the magnetic head starts to fly over the magnetic disk. It may slip out. At this time, in the case of the conventional example in which the side surface is not wrapped as shown in FIG. 6 (A), the surface of the side surface affects the disk and lowers the reliability. On the other hand, when the surface roughness Ra is reduced by wrapping the side surface as in the present invention shown in FIG. 6B, the side surface of the magnetic head also has a surface roughness even if the posture is greatly inclined due to an assembly error or a processing error. Since Ra is made small, the reliability is not lowered. As described above, when the magnetic head is used for loading and unloading, lapping on the side surface of the magnetic head has a great effect for improving reliability.

(2) Effect of blending processing A magnetic head obtained by further blending the side ramp head described in (1) above will be compared with a conventional example.
A test piece made of the same material as the slider material of the magnetic head having a total length of 4 mm, a total width of 3 mm and a total height of 1 mm is prepared, and the entire surface is lapped so that Ra = 1 nm. This test piece is divided into one with a blending process on the air bearing surface side and the other as it is, and an assembly is performed on the suspension to perform a sliding test on a rotating magnetic disk. On this occasion,
The posture of the test piece is tilted with respect to the magnetic disk, and the posture is set to 60 μm in both the pitching direction and the rolling direction as shown in FIG. 10 is a test piece. An AE sensor for measuring the contact level between the test piece and the magnetic disk is mounted on the arm on which the suspension is mounted. In this state, the test piece 10 was subjected to a sliding test on the magnetic disk, and Table 2 shows the voltage value of the AE output and the time until the crash with the two test pieces.

[0013]

[Table 2]

As can be seen from Table 2, the one with blend processing has a smaller contact force than the one without blend processing and is less likely to crash. This is because there is a difference in the manner of contact between the test piece and the magnetic disk. The edges of the unblended test pieces have right angles (Fig. 7).
(A)), since the blended test piece has roundness (FIG. 7 (B)), the magnetic disk is soft and the damage is small. This seems to be a difference in reliability.

By reducing the surface roughness of the side surface of the magnetic head as in the present invention, the reliability becomes higher than that of the conventional example. In addition, the blending process promises higher reliability. Although the slider material is MnZnFerrite in the experiment, the same effect can be obtained by using other materials.

[0016]

As is apparent from the above embodiment, the present invention improves the reliability during load / unload by wrapping the side surface of the magnetic head so that the surface roughness Ra is 3 nm or less. Further, if the magnetic head is subjected to blending processing, there is an effect that higher reliability is promised.

[Brief description of drawings]

FIG. 1 is a drawing of a magnetic head according to an embodiment of the present invention.

FIG. 2 is a side view and a front view showing a loading state of a magnetic head.

FIG. 3 is a diagram showing a load bar.

FIG. 4 is a side view of the blend processing machine.

FIG. 5 is a diagram showing setting of a posture of a test piece with respect to a disc during an experiment.

FIG. 6 is a diagram showing a state in which a magnetic head according to the related art and the present invention are in contact with a magnetic disk.

FIG. 7 is a view showing a state in which a test piece corresponding to a magnetic head with / without blend according to the present invention is in contact with a magnetic disk.

FIG. 8 is a diagram showing a relationship between surface roughness and AE output.

FIG. 9 is a drawing of a conventional magnetic head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic head, 2 ... Magnetic disk, 3 ... Suspension, 4 ... Load bar, 5 ... Arm, 6 ... Stage, 7 ... Wrapping tape, 8 ... Magnetic head attachment part, 9 ... Weights, 10 ... Test piece.

Claims (3)

[Claims] 1. A magnetic head for use in a magnetic disk device, wherein an air bearing surface facing a magnetic disk and two side surfaces having a positional relationship at a right angle to said air bearing surface are substantially parallel to said magnetic head running direction. And a surface roughness Ra of a total of five surfaces, namely, a side surface on the side where air for floating the magnetic head flows in and a surface opposite to the air bearing surface.
Of 3 nm or less. 2. A magnetic head used in a magnetic disk device, wherein an air bearing surface facing a magnetic disk and two side surfaces which are in a positional relationship at a right angle to the air bearing surface and which are substantially parallel to the running direction of the magnetic head. A magnetic head having a total surface roughness Ra of 3 nm or less on a side surface on a side on which air for inflowing the magnetic head flows in. 3. A magnetic head used in a magnetic disk device, wherein a ridge line portion between an air bearing surface and a side surface having a positional relationship perpendicular to the air bearing surface draws a gentle curved surface. Alternatively, the magnetic head described in 2.