JPH03263665A - Floating type magnetic head - Google Patents

Abstract

PURPOSE:To reduce inverse magnetostriction and to improve the performance and reliability by covering a half of a rear side area of a slider or over with an adhesive tape or a coated resin. CONSTITUTION:An area being 50% or over of an area of a rear face 43 of a slider 11 is covered by an adhesive tape or a coated resin. Thus, the amplitude of the vibration of the slider 11 itself is small and occurrence of the self- vibration is prevented. As a result, a magnetic head chip 12 is imbedded to a slot of air bearings 41, 42 of the slider 11 and only an opposite face to the disk is fixed by a secondary glass 32, then deformation of the magnetic head chip 12 is reduced. Thus, generated reverse magnetostriction is less and the performance and reliability of the magnetic head are improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a floating magnetic head used in a fixed magnetic disk drive, and in particular to a floating magnetic head (hereinafter referred to as "magnetic head") with improved performance and reliability. It is sometimes called.

).

(Prior art and problems to be solved) As a floating magnetic head used in a fixed magnetic disk device, in which a slider is bonded to a gimbal and the gimbal is held on a cantilevered load arm, for example, Japanese Patent Application Laid-Open No.
Floating magnetic heads such as those disclosed in Japanese Patent Laid-open No. 1-248303 and Japanese Unexamined Patent Publication No. 1-248303 are used.

Conventionally, the mainstream of disks used as magnetic recording media was to coat an aluminum alloy substrate with oxide magnetic powder.
In response to recent demands for high recording density, fixed disks in which magnetic powder is adhered to a substrate using a plating method, a sputtering method, or the like are becoming mainstream. As a magnetic head used in such a fixed disk with high coercive force, for example, a Fe-AQ-5i alloy magnetic thin film having a high saturation magnetic flux density is used.

, Mn − has high Bs and high magnetic permeability at high frequencies.
A magnetic head chip (hereinafter sometimes referred to as "chip J") as shown in Fig. 3, which has a film formed on one of the cores made of Zn ferrite and is bonded to the other core with primary glass, is attached to the slider. Insert it into the groove provided at the end of the outflow part of the air bearing, fix only the magnetic recording medium side with secondary glass, and apply a winding (not shown) to the winding window of the magnetic head chip. There is a floating magnetic head constructed as shown in FIG.

Note that a floating magnetic head having a structure in which no alloy magnetic film is formed on the core is also used.

Then, as shown in Figure 5, the slider of the magnetic head with this structure is glued to the gimbal, and as shown in Figure 6, the gimbal is held on a cantilevered load arm and placed opposite the disk. Floating magnetic heads are widely used.

(Problems to be Solved) The above-mentioned conventional floating magnetic head uses a core of Mn-Zn ferrite, which has a high Bs and high magnetic permeability at high frequencies, and an F e -A core which has an even higher saturation magnetic flux density.
By forming a film of Q-Si alloy, it has become possible to handle high-density fixed disks.

However, fixed disk devices have become more dense, that is, have larger capacities, and have also become smaller and have higher frequencies.
New issues have arisen that need to be resolved. The floating magnetic head, which is held by a cantilevered load arm via a gimbal, makes light contact with the disk when the disk is stationary due to the force of a spring, but when the disk is rotating, The air on the disk surface moves and a force is applied to lift the bottom surface of the slider, causing it to float away from the disk (0°2~
(approximately 0.5 μm). On the other hand, when the disk starts and stops rotating, the magnetic head slides on the disk. If this levitation is stable, stable electromagnetic conversion characteristics can be obtained.

However, in reality, minute upward and downward movements are repeated during seek operations and the like. The interaction between this upward and downward movement and the airflow caused by the rotation of the disk causes vibrations in the entire magnetic head. This vibration is considered to be a type of self-excited vibration in which the vibration itself gives energy to the magnetic head and the amplitude gradually increases.

Furthermore, such self-excited vibrations may be induced by collisions between minute protrusions on the disk and the slider during flight.

Conventional floating magnetic heads have the following measures to damp vibration:
As disclosed in Japanese Patent Application Laid-Open No. 63-7573,
When fixing the load arm 61 with a cantilevered structure as shown in FIG. Measures have been taken to suppress the damping of the slider 11, but no measures have been taken to suppress the vibration of the slider 11 itself.

Therefore, a magnetic head chip is buried in the air bearing groove of the slider.1. In a floating magnetic head in which only the side facing the disk is fixed with secondary glass, the rear side of the magnetic head chip is in a free state. Therefore, the amplitude of the vibration transmitted from the slider is amplified, and the magnetic head chip vibrates in a cantilevered state at a frequency different from that of the slider. When the magnetic head chip vibrates, the chip expands and contracts in the height direction and width direction, resulting in deformation. It is presumed that due to this deformation, the magnetic head chip, which is a magnetic material, exhibits a phenomenon of reverse magnetostriction in which the state of magnetization differs from the initial state of magnetization. In this way, when reverse magnetostriction occurs, the magnetization distribution of the magnetic material that makes up the magnetic circuit changes, causing magnetic flux changes within the magnetic hentochive, which generates voltage through the windings and causes noise. This is considered to be a factor in the generation of noise, and has an adverse effect on the S/N ratio between the output S of the magnetic head and the noise N, and on the waveform of reproduction.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a magnetic head chip in which a magnetic circuit is configured by a pair of magnetic core pieces, and the pair of core pieces are bonded together using primary glass. is inserted into a groove provided on the magnetic recording medium outflow end side of the air hair ring of a slider made of a non-magnetic material, and the slider with the magnetic hent tip inserted and fixed is adhered to a gimbal and held by a load arm with a single cantilever structure. In claim (1), 5 of the back surface area of the slider
A floating magnetic head characterized by having 0% or more covered with adhesive tape or coated resin.

According to a second aspect of the present invention, there is provided a floating magnetic head characterized in that 50% or more of the back surface area of the slider bonded to the gimbal is covered with an applied adhesive.

(Function) The vibration countermeasure against conventional floating magnetic head vibration is to attach tape to the spring part 72 near the root of the load arm 61 when fixing the rotor arm 61 with a single cantilever structure to the head arm 71. Although measures have been taken to suppress the damping of the vibrations of the load arm 61, no measures have been taken to suppress the vibrations of the slider 11 itself. In contrast, in the floating magnetic head of the present invention, when the slider is bonded to the gimbal, 50% of the back surface area of the slider is
Measures to damp the vibration of the slider itself by covering the above with adhesive tape or applied resin, or by covering 50% or more of the back surface area of the slider bonded to the gimbal with applied adhesive. is being carried out.

Therefore, the amplitude of the vibration of the slider itself is smaller than that of a conventional magnetic head that does not take measures against vibration of the slider itself, and self-excited vibration can be prevented from occurring. As a result, the magnetic head chip was embedded in the air bearing groove of the slider (1), and only the side facing the disk was fixed with secondary glass, leaving the rear side of the magnetic head chip free. However, since the vibration transmitted from the slider is minute, even if the amplitude of the vibration is amplified and the magnetic head chip vibrates in a cantilevered state at a frequency different from that of the slider, the height direction of the chip 5 Deformation caused by expansion and contraction in the width direction, etc., is also very small compared to deformation of conventional magnetic head chips.

As a result.

The generated reverse magnetostriction is also small, and the performance and reliability of the magnetic head can be improved.

Example 1 Mn○: 28 mol%, ZnO: 19 in a pair of magnetic cores
mol %, the remainder essentially consists of M, n −
Using Zn single crystal material, Au: 6%, Si: 8% by weight
%, the remainder is essentially Fe, commonly known as Sendust,
An Fe-A M-Si magnetic thin film was formed on one core by sputtering, and the pair of cores were bonded with glass using a conventional method to form a magnetic head chip.

Next, this tip is inserted into a groove formed in the rear outflow end of the air bearing of a slider made of Ca Ti,03, for example.

Again, using the same known technique as in the prior art, the disk facing side of the magnetic hent chip was fixed with secondary glass, and finished grinding and polishing were performed to create a magnetic head. Adhesive tape was attached to the back of the slider of this magnetic head, or epoxy resin was applied, winding was applied, and the slider was attached to the gimbal. Then, we held the gimbal on the rotary arm and checked for noise generation. The first step is to attach adhesive tape to the back of the slider or apply epoxy resin.
As shown in the figure, we investigated the effects of changing the ratio of the area covered by the adhesive tape and the applied resin on the back surface.

Table 1 shows the results.

Table 1 (Note) Test numbers 2.5, 6, and 7. Glue the tape.

3a, 4a, and 8a are resin bonded.

The noise level represents a relative value when no processing is set to 100.

The area ratio is the ratio of the area covered with tape or resin to the total area of the back surface of the slider.

As is clear from Table 1, in both tape adhesion and resin coating, by covering 50% or more of the slider back surface area with tape or resin, the relative level of noise can be reduced to less than half. Furthermore, especially when the area is increased to 80% or more, the reduction value becomes extremely large.

In addition, tape the entire front or side of the slider.
I covered it with resin and did a similar test.

The relative noise level was 100 for the front and 70 for the side, so there was almost no effect. This is thought to be because the vibration of the load arm propagates to the slider via the gimbal where it is held, and the degree of damping between the slider and gimbal is small.

Example 2 Next, as shown in Fig. 2, a magnetic head made in the same manner as in Example 1 was coated with adhesive on parts other than the regular adhesive part on the back of the slider. The generated noise level was checked by changing the ratio of covered area.

Table 2 shows the results.

Table 2 (Note) The noise level represents the relative value when normal (adhesive is applied only to the normal adhesive part is set as 100).

The area ratio is based on the total area on the back of the slider.

This is the ratio of the area covered with adhesive.

From Table 2, compared to a magnetic head in which adhesive was applied only to the regular adhesive area on the back of the slider, the relative level was reduced to less than half when more than 50% of the slider back area was covered with adhesive. I understand that. In particular, the ratio is 7
Above 0%, the noise reduction is significant.

At this time, examples were given in which adhesive tape or epoxy was bonded or applied, but there is no difference in effectiveness unless the thickness of the tape or resin is at least 10 μm.
The upper limit affects the weight of the slider, so the upper limit is about 200 μm.

In addition, in the examples, M n
Although the example of -Zn single-crystal ferrite has been given, the present invention may also be applied to polycrystalline ferrite, magnetic heads using other magnetic materials, and magnetic heads that do not have a metal magnetic thin film as a bottom film. Needless to say, it is included in the scope of the claims.

(Effects of the Invention) As is clear from the above embodiments, the magnetic head of the present invention has high density, large capacity, and even when used in a small, high-frequency fixed magnetic disk device, it is possible to suppress vibrations from the slider. The magnetic head generates less noise, which is thought to be caused by inverse magnetostriction, which is thought to be an influence, and can obtain a good signal-to-noise ratio of the noise N to the output S of the magnetic head, as well as a good reproduction waveform, and has improved performance and reliability. It becomes possible to provide

[Brief explanation of drawings]

Figure 1 shows the state in which tape is glued or resin is applied to the back of the slider of the floating magnetic head of the present invention, Figure 2 shows the state in which adhesive is similarly applied, and Figure 3 is a perspective view of the magnetic head chip. , FIG. 4 is a perspective view of the floating magnetic head, and FIG. 5 is a perspective view of the floating magnetic head.
The figure shows the state of adhesion of the slider to the gimbal, Figure 6 shows the relationship between the attachment of the gimbal and the funnel arm, and Figure 7 shows the conventional vibration countermeasures for the rotor arm. Slider 13, Tape, Resin 22, Gimbal 32, Primary glass 43, Slider back 12, Magnetic head tip 21, Adhesive 31, Core 41, 42. ,, air bearing 44, , slider side 45. , Slider front 61 , Load arm 71 , Head arm 72 , Spring part 73 , Disc

Claims (1)

[Claims] A magnetic circuit is constituted by a pair of magnetic core pieces, and a magnetic head chip formed by bonding the pair of core pieces with primary glass is used for magnetic recording of an air bearing of a slider made of a non-magnetic material. In a floating magnetic head in which a slider with the magnetic head chip inserted and fixed into a groove provided on the media outflow end side is bonded to a gimbal and the gimbal is held on a cantilevered load arm, (1) A floating magnetic head characterized in that 50% or more of the back surface area of the slider is covered with an adhesive tape or a coated resin. (2) A floating magnetic head characterized in that 50% or more of the back surface area of the slider bonded to the gimbal is covered with an applied adhesive.