JPS63312056A - Polishing device for magnetic head - Google Patents

Abstract

PURPOSE:To eliminate difference in level between different types of materials generated at the time of polishing a magnetic head by projecting out a magnetic head from the outer peripheral face of a cylinder for a defined quantity and jetting out a liquid outward from the inside of the cylinder while running a polishing tape along the outer periphery of the magnetic head. CONSTITUTION:Water jet-out nozzles 15 are provided on the face with which a polishing tape 3 is brought into contact of a cylinder 14 to feed water to the nozzles 15 from a body side and a rotary cylinder 2 to which a magnetic head 1 is fixed is installed on the hub 16 which is interlocked with a motor of the fixed cylinder 14. And, by running the polishing tape 3, as the rotary cylinder 2 is rotated while jetting water out of the nozzles 15, the magnetic head 1 is polished by the polishing tape 3 which is floated up from the fixed cylinder 14 due to the pressure of water, thereby, without causing difference in level between different materials exposed on the sliding face of the medium, eliminating the need for varying the projecting quantity of the magnetic tape or the tension of the tape.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for polishing a medium sliding surface of a magnetic head for a rotating cylinder used in a VTR or the like.

BACKGROUND OF THE INVENTION Conventionally, the medium sliding surface of a magnetic head is shaped to suit the running condition of the medium. In addition, in order to reduce fine irregularities caused by pre-processing in the main parts of the magnetic head, especially near the magnetic gap, a polishing sheet or polishing tape with an abrasive material sprinkled on an organic film is used to polish the magnetic head's medium. The sliding surface is mirror polished. An example thereof is shown in FIG.

This figure is a plan view schematically showing a method of polishing a magnetic head 1 for a rotary cylinder used in a VTR or the like. In the figure, a magnetic head 1 is fixed to a rotating cylinder 2 so as to protrude a distance t from the circumference of the sliding surface of the polishing tape 3 of the rotating cylinder 2. In this state, rotating cylinder 2
Attach to the rotating system. The polishing tape 3 is attached so as to be wound from the unwinding reel 4 to the take-up reel 7 along the tape guide 6 and the rotating cylinder 2. In this state, the magnetic head 1 is polished by running the polishing tape 3 while rotating the rotary cylinder 2. As a result, the media sliding surface of the magnetic head 1 can be adjusted to a shape suitable for the running condition of the medium, and unevenness caused by pre-processing etc. can be reduced in the main parts of the magnetic head 1, especially in the vicinity of the magnetic gap. .

Usually, at the start of polishing, the particle size of the abrasive being spread is large, and a large abrasive tape 3 is used, which forms the shape of the sliding surface of the magnetic head 1, and as the polishing stage progresses, the particle size becomes smaller. Things are chosen. The abrasive material spread on the abrasive tape 3 is selected depending on the material exposed on the sliding surface of the magnetic head 1, and is generally Fe2O3, Al, etc.
2O3°Cr0z etc. are used.

In recent years, with the increase in the density of magnetic recording devices, the magnetic head 1 has also become
A magnetic head 1 made of different materials has been put into practical use, with most of the magnetic path being made of ferrite, and a CO-based or Fe-based metal material being formed by vapor deposition or sputtering only in the vicinity of the magnetic gap. It is being done. When the magnetic head 1 made of such different materials is polished by the polishing method shown in the conventional example, a step difference of several hundred to several thousand amps often occurs between the materials because the wear characteristics differ between the materials. FIG. 6 shows an example in which such a step occurs. This figure shows that the medium sliding surface of the magnetic head 1 is made of crystallized glass as the substrate 8 and cover 9, CO-based amorphous as the magnetic material 10, 5102 as the gap material 11, and Al as the protective layer 12.
20 s and when each of the adhesive layer 13 is exposed, an example is shown in which measurements were taken in the medium sliding direction with a stylus roughness meter. As can be seen from this figure, there is a step difference of 450 A between the substrate 8 and the magnetic body 10. Assuming that this step corresponds to the separation length d, the separation loss occurring during the regeneration process will be calculated. When the working wavelength λ of the magnetic recording device in which this magnetic head 1 is used is 1 μm, Wal
From the formula for lace, it can be obtained as follows.

Loss = 54.8Xd/λ = 54.8X0.045/1 = 2.47 [dB] Furthermore, since it is thought that there is approximately the same loss during recording, the total separate loss between recording and reproduction is: It is thought that there is a level of about 5 dB. It is easy to imagine that this causes a decrease in the S/N ratio and an increase in the error rate.

Even in the conventional polishing method, by changing the amount of protrusion of the magnetic head 1 with respect to the polishing tape 3 or by changing the tension of the polishing tape 3, it is possible to reduce such a difference in level between different materials by several tens of percent. An example is shown in FIG.

This figure shows the uneven state of the sliding surface when polishing is performed with the amount of protrusion of the magnetic head 1 relative to the polishing tape 3 increased by 100 μm compared to FIG. 6. The measurement conditions are the same as in FIG. Compared to FIG. 6, the height difference between the substrate 8 and the magnetic body 10 is 44.
% smaller.

Problems to be Solved by the Invention However, even if the amount of protrusion of the magnetic head 1 was changed further, this difference in level could not be reduced. In addition, similar studies were conducted by changing the tension of the polishing tape 3 by slightly different rotational speeds between the unwinding reel 4 and the take-up reel 7, but if the difference in level could be made any smaller, There wasn't. Therefore, by changing the amount of protrusion of the magnetic head 1 or the tape tension, it is not possible to fundamentally eliminate the difference in level between different materials. Furthermore, with this method, the tip shape of the magnetic head 1 changes greatly, so when the magnetic medium and the magnetic head 1 are actually slid, the tip shape of the magnetic head 1 will change from the shape that is suitable for the running condition of the medium. The hooks become separated, and the vicinity of the magnetic gap ends up sliding against the medium, which often results in a decrease in the output from the magnetic head 1.

As described above, with the conventional techniques, it is difficult to maintain the tip shape of the magnetic head as before while polishing the magnetic head so that the unevenness between different materials is sufficiently reduced.

Means for Solving the Problems A mechanism is provided in which a magnetic head is rotated by protruding from the outer periphery of a cylinder by a predetermined amount, and an abrasive tape on which abrasive material is spread on a flexible substrate is run along the outer periphery of the cylinder. A polishing device for a magnetic head is provided, including a mechanism and a mechanism for ejecting liquid from the inside of the cylinder to the outside along the travel path of the polishing tape.

Although the specific action of the working water is unknown, by using this device, it is possible to polish magnetic heads made of different materials with different wear characteristics to a state where there are extremely few differences in level between the different materials. be. Further, since polishing can be performed without changing the amount of protrusion of the magnetic head relative to the polishing medium or the tension of the polishing medium, the shape of the sliding surface of the magnetic head can be maintained as before.

Example Hereinafter, specific embodiments of the present invention will be described using the drawings.

FIG. 1 is a perspective view of a portion of a cylinder showing a first embodiment of the present invention. In the figure, the fixed cylinder 14 includes:
A water blowing nozzle 15 is provided on the abutting surface of the polishing tape 3, and is designed in advance so that water can be supplied to the water blowing nozzle 15 from the main body side to which the fixed cylinder 14 is attached. A hub 16 interlocked with a rotary motor is provided in the center of a fixed cylinder 14, and a rotary cylinder 2 to which a magnetic head 1 is fixed is attached to the hub 16. The cylinder thus installed is applied to the same abrasive tape running system as shown in FIG. When polishing the magnetic head 1, the rotating cylinder 2 is rotated while blowing out water from the blowing nozzle 15.

When such a polishing method is used, the magnetic head 1 is polished by the polishing tape 3 to which water is attached, so that no difference in level occurs between different materials exposed on the medium sliding surface of the magnetic head 1. FIG. 2 shows the unevenness of the medium sliding surface of the magnetic head 1 polished by the polishing method of this embodiment. However, the amount of protrusion of the magnetic head 1 relative to the polishing tape 3, the tension of the polishing tape 3, and the measurement conditions are the same as in FIG. A comparison with FIG. 7 shows that the level difference between the substrate 8 and the magnetic body 10 has been largely eliminated.

Therefore, in the magnetic head 1 subjected to the polishing method of this embodiment, it is considered that separation loss caused by the step difference between different materials hardly occurs. In addition, with this method, there is no need to change the amount of protrusion of the magnetic head 1 with respect to the polishing tape 3 or the tape tension.
The shape of the sliding surface can be maintained as before. Normally, the abrasive tape 3 abutting surfaces of the rotating cylinder 2 and the stationary cylinder 14 are finished with extremely few irregularities. Therefore, if liquid such as water adheres to the polishing surface of the polishing tape 3, the polishing tape 3 will firmly adhere to the fixed cylinder 14 or the rotating cylinder 2, and not only will the polishing tape 3 not run smoothly. In extreme cases, the polishing tape 3 may be cut by the rotational force of the take-up reel.

In this embodiment, in order to prevent such a situation,
By blowing out water from the fixed cylinder 14, the polishing tape 3 is slightly floated from the fixed cylinder 14 due to its pressure. As a result, the polishing tape 3 does not stick to the cylinder and can run smoothly on the cylinder surface.

Next, a second embodiment of the present invention will be described using FIG. 3.

The figure shows a water blowing nozzle 15 on the rotating cylinder 2 side.
FIG. 3 is a perspective view showing an example in which a In the same figure, the magnetic head 1 of the rotary cylinder 2 is attached to the surface and the water receiver is grooved 17.
A water spout nozzle 15 is connected to the water receptacle groove 17. The rotating cylinder 2 processed in this way is attached to the polishing machine body through the fixed cylinder 14 so that the surface on which the water blowing nozzle 15 is processed faces upward. In addition to the hub 16 that rotates the rotary cylinder 2, the fixed cylinder 14 is provided with a nozzle that supplies water to the groove 17 of the water receiver. The magnetic head 1 is polished using the cylinder system prepared in this way and the running system for the polishing tape 3 shown in FIG. Before starting polishing, add an appropriate amount of water to the water receiver in groove 17.
After that, the rotating cylinder 2 is rotated and the abrasive tape 3 is run. At the same time as the polishing starts, the water receiver supplies water to the groove 17 from the polishing machine main body side.

In the case of this embodiment, since water can be supplied to the polishing tape 3 immediately before the magnetic head 1, uneven supply of water in the vicinity of the magnetic head 1 is less likely to occur. In FIG. 3, in order to make the pressure from the polishing tape 3 applied to the magnetic head 1 symmetrical about the main part of the magnetic head 1,
The water blowing nozzle 15 is shown as an example in which the magnetic head 1 is attached before and after the position. As described in the first embodiment, if the abrasive tape 3 sticks strongly to the cylinder, it is advisable to increase the number of water blowing nozzles 15 to prevent this.

Furthermore, FIG. 3 shows a water receptacle in which a groove 17 is provided on the opposite side of the rotary cylinder 2 to which the magnetic head 1 is attached. In this example, since the groove 17 of the water receiver is provided on the opposite side of the magnetic head 1, the water blowing nozzle 15 is provided obliquely as shown in the cross-sectional view. The manner in which water acts is the same as that shown in FIG. 3, so a description thereof will be omitted.

Moreover, similar effects can be expected even if the magnetic head 1 is polished by combining the first embodiment and the second embodiment.

In the embodiments described above, the case of water has been explained as an example of the liquid ejected from the cylinder, but as a result of similar studies on other liquids, methanol, ethanol, wrapping oil, J
HON CRANE LAPPING VEIICLE
It was found that even if No. 3) was used, there was an effect of reducing the level difference between different materials.

Effects of the Invention According to the present invention, even in a magnetic head made of different materials having different hardnesses, it is possible to eliminate the level difference between the different materials that occurs after polishing. Furthermore, since polishing can be performed without changing the amount of protrusion or tension of the magnetic head relative to the polishing medium, the shape of the sliding surface of the magnetic head can be maintained as before. Furthermore, since the liquid is sprayed onto the polishing medium from the cylinder side, the polishing medium can be raised slightly above the cylinder, which prevents the polishing medium from sticking to the cylinder due to the liquid adhering to the polishing medium. .

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a portion of a cylinder showing a first embodiment of the present invention, FIG. 2 is a diagram showing the uneven state of the sliding surface of a magnetic head subjected to the polishing method of the present invention, and FIG. 3 is a diagram showing the present invention. FIGS. 4(a) and 4(b) are respectively a plan view and a sectional view of the rotating cylinder showing the third embodiment of the present invention, and FIG. 5 is a conventional example. 6 and 7 are diagrams showing the uneven state of the sliding surface of a magnetic head subjected to a conventional polishing method. 1... Magnetic head, 2... Rotating cylinder, 14.
・・Fixed cylinder, 15 ・・Water blowing nozzle, 1
6...Hub. Agent's name: Patent attorney Toshio Nakao 1 idiot/--One eyebrow, 1 ki, y do 2-11 rotation cylinder 14-ignition cylinder 6-71<1 missing t no suru/6-11 Figure 1 Figure 2 Figure 3 Figure 4 ((L) 2 (b) /7 Turtle A-A' Maeyama Figure 5)

Claims (1)

[Claims] A mechanism for causing a magnetic head to protrude from the outer periphery of a cylinder by a predetermined amount and rotating it; a mechanism for running an abrasive tape with an abrasive material spread on a flexible substrate along the outer periphery of the cylinder; and a mechanism for causing the abrasive tape to run. A magnetic head polishing device comprising a mechanism for ejecting liquid from the inside of the cylinder to the outside along a path.