JP2000268517A - Magnetic disk device and its slider mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a slider of a magnetic disk device capable of suppressing the fluctuation of an actuation in the perpendicular direction of the magnetic disk detrimental to the recording and reproducing characteristics generated when a microactuator of a magnetic head element drive type designed to expand a magnetic head positioning control band by increasing the resonance frequency of a magnetic head drive system is used. SOLUTION: The slider is formed of a two-stage slider structure consisting of a main slider 1 having a relative high flying height and a secondary slider 2 of a low flying type and microminiature size mounted with a magnetic head element. Only the secondary slider 2 is microdriven in the radial direction of the magnetic disk by the microactuator structure. As a result, the fluctuation in the magnetic disk perpendicular direction of the actuator detrimental to the recording and reproducing characteristics generated when the microactuator of the magnetic head element drive type is driven in order for the structure body (i.e., the secondary slider) including the magnetic head element part which is the object to be driven of the microactuator to itself form a control system for spacing between the magnetic head and a method disk medium can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slider mechanism for mounting a magnetic head of a hard magnetic disk drive, and more particularly to a magnetic disk drive and a slider mechanism suitable for suppressing vertical fluctuation of an actuator in a magnetic disk.

[0002]

2. Description of the Related Art Conventionally, a hard magnetic disk drive (HD)
In D), the tracking operation for moving the magnetic head on an appropriate track has been performed only by a voice coil motor (VCM). However, such a VCM-only drive system has a movable range that covers the tracks on the entire surface of the magnetic disk, and at the same time, a drive resolution (accuracy) corresponding to a track pitch that will continue to decrease with the promotion of higher recording density. ) Is becoming an extremely difficult situation. Also, from the viewpoint of the head positioning control band, it is difficult to respond to the demand for a higher band, which continues to increase in the future, with a drive system using only the VCM. Therefore, in the future, it is considered essential to apply a two-stage actuator combining a VCM and another fine movement actuator.

[0003] For example, "June 1995, IEE
E-E Transaction on Industrial Electronics, Vol. 42, No. 3, 222-233
Page (IEEE Transaction on Industrial Electronics, Vo
l.42, No.3, pp.222-233, June 1995) "
(Authors: LS Fan, HH Ottesen, TC Reiley and
RW Wood), or "1996, Proceedings of IEE MEMS-96,
216-221 (Proceedings of IEEE MEMS-96, p
p.216-221, 1996) "(Author: Takahiro Imam
As shown in ura, Takao Koshikawa and Masaki Katayama), a microactuator manufactured using micromachine technology has been proposed as a two-stage actuator fine movement actuator.

FIGS. 2 to 4 are schematic perspective views of a head gimbal assay (HGA) integrating a microactuator and a slider / suspension system described in the above document.

FIG. 2 is a schematic perspective view showing a conventional head gimbal assay (HGA) in which a microactuator is incorporated between a slider and a suspension. 2, reference numeral 21 denotes a slider, 26 denotes a suspension, 27 denotes a microactuator, and 28 denotes a magnetic head element. In this method, a microactuator 27 between the slider 21 and the suspension 26 is incorporated,
The entire slider 21 is driven.

FIG. 3 is a schematic perspective view of a head gimbal assay (HGA) in which a microactuator is formed by linking a magnetic head element and a slider according to another conventional example, and FIG. FIG. 2 is an enlarged schematic perspective view.
3 and 4, 31 is a slider, 35 is an air bearing surface, 36 is a suspension, 37 is a microactuator, and 38 is a magnetic head element. In this method, the dimension between the leading side and the trailing side of the slider is 0.8 mm, its vertical dimension is 0.6 mm, and the disk rotation direction is the direction of the arrow in FIG. The micro-actuator 37 is interposed between the magnetic head element 38 and the slider 31, and only the magnetic head element 38 is driven separately from the suspension 36 and the slider 31.

The reason why such a microactuator is considered to be a prominent two-stage actuator is that it is advantageous for miniaturization,
High mechanical resonance is expected.

On the other hand, in a conventional HDD, the spacing (gap) between a magnetic head and a magnetic disk medium is controlled by mounting a magnetic head on a floating head slider (hereinafter simply referred to as a slider) which is a dynamic pressure type gas bearing. It has been performed by floating the slider stably on a magnetic disk rotating at high speed.

As described above, in order to stably levitate the magnetic head in a minute gap, the slider is joined to the suspension via a gimbal spring which is an extremely flexible spring, and supports the slider while applying an appropriate load to the slider. ing. At present, the flying height of the slider has reached the level of several tens of nanometers. However, in order to further increase the recording density of the magnetic disk device, the magnetic disk followability and rigidity are high.
In addition, a floating head system capable of realizing low spacing is required. In the flying region of about 50 nm or less, it is estimated that the slider and the magnetic disk are in a so-called near contact state where intermittent contact occurs.

[0010] A low spacing floating head system which solves the mechanical reliability problems of the head / disk interface (HDI) related to the tribology and vibrations associated therewith, and which is excellent in the followability of the magnetic disk as described above. In order to realize the above, it is necessary to reduce the size of the slider. However, in order to reduce the size of the slider, not only must the size of the suspension be reduced, but also the precision of the assembly technology must be increased.

As one means for solving such a problem,
For example, in 1992, ASME, T.R.I.B., Volume 3, pages 27-39 (ASME TRI
B-Vol.3, pp27-39, 1992) "(Author: Jonatha)
n As described in A. Wickert, DN Lambeth and W. Fang, a two-stage system consisting of a main slider having a relatively high flying height and a low-flying ultra-small secondary slider equipped with a magnetic head element A method of manufacturing a slider by a micromachine technique has been proposed.

FIG. 5 is a conceptual diagram of a two-stage slider proposed in this document. In FIG. 5, 51 is a main slider, 52 is a secondary slider, 53 is a microsuspension, and 55 is an air bearing surface. With the magnetic disk arranged at the top of FIG. 5, the magnetic disk and the air bearing surface 55
The main slider 51 is maintained at a distance of about 5 to 25 nm as the flying distance, and the position of the secondary slider 52 is controlled by the microsuspension 53.

The advantage of such a two-stage slider structure of the main slider 51 and the secondary slider 52 is that the magnetic field can be reduced without the need for difficult techniques such as miniaturization of the suspension 53 and high precision of the assembly thereof. Not only is it possible to form a low-spaced floating head system having excellent disk followability, but also it is possible to suppress variations in the flying height of the slider caused by vibrations of the slider support system induced by disturbance.

A conventional example of the above-described magnetic head drive mechanism is disclosed, for example, in Japanese Patent Application Laid-Open No. Hei 5-2868.
The technique described in Japanese Patent Publication No. 3 has been proposed. This publication aims to control the seek drive of the magnetic head and the flying height or contact force between the magnetic head and the recording medium, and as a control element of the seek drive or the flying height or contact force with the recording medium. There has been disclosed a magnetic head driving device characterized by using a piezoelectric element and providing a displacement enlarging mechanism for enlarging the displacement of the piezoelectric element using the principle of leverage.

[0015]

However, the above-described prior art has the following problems.

When the application of a microactuator as a high-accuracy tracking actuator is considered, a method of driving the entire slider by incorporating an actuator between a slider and a suspension is roughly divided into driving targets (FIG. 2).
And a method in which a microactuator is interposed between the magnetic head element and the slider to drive only the magnetic head element (see FIG. 3).

In the former case, there is an advantage that the fluctuation of the actuator 27 in the direction perpendicular to the disk, which is detrimental to the recording / reproducing characteristics, can be mitigated by the air bearing of the slider 21.
Since it is a method that requires a large generating force to drive the whole device at high speed, it is difficult to design a high resonance frequency. Therefore, it can be said that the slider driving method is not suitable for realizing the advantage (that is, higher bandwidth) of the microactuator 27 which is originally expected.

On the other hand, in the latter case, since the object to be driven is an extremely lightweight one such as the head element 38, it is advantageous from the viewpoint of driving force and resonance frequency, and matches the original purpose of the microactuator 37. However, the fluctuation in the vertical direction of the magnetic disk of the microactuator 37, which cannot be completely suppressed, is directly reflected in the fluctuation of the spacing between the magnetic head element 38 and the magnetic disk medium. Becomes

An object of the present invention arises when a magnetic head element driving type microactuator is used which increases the resonance frequency of the magnetic head driving system and can expand the magnetic head positioning control band as described above. An object of the present invention is to provide a slider mechanism of a magnetic disk drive capable of suppressing a fluctuation in a direction perpendicular to a magnetic disk of an actuator which is harmful to recording / reproducing characteristics.

[0020]

According to the present invention, there is provided a slider mechanism of a magnetic disk drive for writing / reading data on / from a magnetic disk, wherein the slider mounted on the suspension has a two-stage structure integrated with a microactuator and is relatively high. A two-stage structure of a main slider having a flying height, and a low-flying secondary slider supported by a trailing edge of the main slider and mounted with a magnetic head element;
The secondary slider is minutely driven in the radial direction of the magnetic disk by the microactuator.

The present invention also relates to a magnetic disk drive having a slider mechanism in a magnetic head, wherein the slider mounted on the suspension has a two-stage structure integrated with a microactuator, and a main slider having a relatively high flying height. And a low-flying secondary slider supported by the trailing edge of the main slider and mounting the magnetic head element, wherein a comb-shaped electrode is formed between the secondary slider and the main slider. The next slider is supported by the main slider.

The slider mechanism of the magnetic disk drive according to the present invention will be described with reference to FIG. 1. In the slider structure of the magnetic disk drive, the slider mounted on the suspension 7 is mounted on an air bearing surface (5 in FIG. 1). ) Having a relatively high flying height (1 in FIG. 1);
It has a two-stage structure including a low-flying type secondary slider (2 in FIG. 1) on which a magnetic head element (6 in FIG. 1) is mounted, and only the secondary slider (2 in FIG. 1) is a micro-suspension (FIG. 1). Using the microactuator structure according to 1-3), the magnetic disk is minutely driven in the radial direction.

Further, the secondary slider (2 in FIG. 1) is
The main slider (1 in FIG. 1) is supported via a microsuspension (3 in FIG. 1) composed of a plurality of springs each having a plurality of folded structures.

The interface between the fixed electrode extending from the main slider (1 in FIG. 1) and both side surfaces of the secondary slider (2 in FIG. 1) has a comb electrode structure (4 in FIG. 1). .

The secondary slider (2 in FIG. 1), the microsuspension (3 in FIG. 1) and the comb electrode structure (4 in FIG. 1) constitute a low-flying floating head system, and It has a microactuator structure.

Further, only the secondary slider (2 in FIG. 1) is minutely driven in the radial direction of the magnetic disk by using an electrostatic drive type microactuator structure.

Only the secondary slider (2 in FIG. 1) is minutely driven in the radial direction of the magnetic disk by using an electromagnetically driven microactuator structure.

Also, only the secondary slider (2 in FIG. 1) is minutely driven in the radial direction of the magnetic disk by using a piezoelectric drive type microactuator structure.

The main slider (1 in FIG. 1) and the secondary slider (2 in FIG. 1) are both negative pressure type sliders.

The main slider (1 in FIG. 1) and the secondary slider (2 in FIG. 1) are both positive pressure type sliders.

One of the main slider (1 in FIG. 1) and the secondary slider (2 in FIG. 1) is a negative pressure slider, and the other is a positive pressure slider.

[Operation] The slider mechanism of the magnetic disk drive of the present invention comprises a main slider having a relatively high flying height, and a low-flying ultra-compact secondary slider on which a magnetic head element is mounted. Two-stage slider structure
Only the next slider is minutely driven in the radial direction of the magnetic disk by the microactuator structure.
Therefore, the structure including the magnetic head element portion to be driven by the microactuator (that is, the secondary slider) independently forms a magnetic head / magnetic disk medium spacing control system, and thereby drives the magnetic head element. It is possible to suppress the fluctuation of the actuator in the vertical direction of the magnetic disk, which is harmful to the recording / reproducing characteristics when the micro-actuator is driven.

[0033]

Embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment] First, a first embodiment of the present invention will be described. As shown in other modified examples of the present invention, as a drive method of the microactuator of the magnetic disk drive, an electromagnetic drive type, a piezoelectric drive type, and the like can be considered in addition to the electrostatic drive type.

In the case of this electromagnetic drive type, the structure becomes considerably complicated due to the necessity of forming a coil. In addition, there is a concern about the influence of the generated field on a recording / reproducing system using electromagnetic conversion as its basic principle. Further, in the case of the piezoelectric drive type, there is a problem in long-term mechanical reliability of the material in addition to having undesirable characteristics from the viewpoint of a control system such as hysteresis and creep.

On the other hand, in the case of the electrostatic drive type, (1) the structure is simple and the fabrication process is easy, and (2) the generated force is a surface force, which is advantageous for downsizing.
(3) There are various merits such as that the occurrence field hardly affects the recording / reproducing system. For these reasons, in the first embodiment of the present invention, the electrostatic drive type is adopted as the microactuator drive system.

Next, regarding the first embodiment of the present invention,
This will be described in detail with reference to the drawings.

(1) Description of Configuration FIG. 1 is a schematic perspective view showing a first embodiment of a micro-actuator-integrated two-stage slider of the present invention. In the figure, 1 is a main slider, 2 is a secondary slider, 3 is a micro suspension, 4 is a comb electrode structure, 5 is an air bearing surface, 6 is a magnetic head element, and 7 is a suspension supported by an actuator (not shown). is there.

Also, in the drawing, 1 corresponds to the main slider, and a negative pressure type nano slider (50
% Slider). The trailing edge of the main slider 1 has three folded structures
An ultra-small slider 2 of about 0.2 mm square is supported via a microsuspension 3 composed of book springs. This corresponds to a secondary slider, and in the present embodiment, it is of a negative pressure type design like the main slider 1.

The interface formed by both side surfaces of the secondary slider 2 which is perpendicular to the end surface to which the microsuspension 3 is joined and the fixed electrode extending from the trailing edge of the main slider 1 forms the comb electrode structure 4. Has formed. The gap d between the comb teeth is about 2 μm, and the height h of each opposing electrode is about 200 μm.

In the structure of the secondary slider 2, the left and right side surfaces forming the comb electrode and the end surface on the trailing side on which the head element is formed have a thick structure of 200 μm in height. The rear surface of the secondary slider 2 (the surface opposite to the air bearing surface) is provided with a deep-drilled structure (a U-shape along the edge of the rear surface of the secondary slider 2) in order to reduce the mass of the secondary slider 2 as much as possible. The thickness from the back surface of the deeply dug secondary slider 2 to the recessed surface on the air bearing surface side is about 12 μm, which is the same as the thickness of the microsuspension 3. The mass of the secondary slider 2 having such a structure is about 18 μg with the head element mounted.

As described above, the secondary slider 2, the microsuspension 3, and the comb electrode structure 4 constituting the trailing portion of the main slider 1 form a second ultra-low floating head system. At the same time, they are themselves microactuators. It should be noted that all of the fine structures shown in FIG. 1 are made by micromachining technology, and the material is an integrated structure of, for example, Ni.

(2) Description of Operation Next, the operation of the first embodiment of the present invention will be described in detail with reference to FIG.

The entire floating head system using the two-stage slider shown in the first embodiment of the present invention reaches a steady flying state by the load / unload method. The secondary slider 2 self-loads by the negative pressure after the main slider 1 is loaded, and reaches a steady flying state.

The micro-suspension 3 supporting the secondary slider 2 functions as a spring structure of a micro-actuator that enables the relative movement of the secondary slider 2 in the radial direction of the magnetic disk. A negative pressing load is applied to the secondary slider 2 to perform a function as a gimbal that restricts movement in the flying height direction (Z direction), pitch, and roll direction.

When a voltage is applied to the comb electrode structure 5 formed by one of the two fixed electrodes extending from the left and right trailing portions of the main slider 1 and the side surface of the secondary slider 2 opposed thereto. , Electrostatic attraction acts on the interface between both electrodes,
The secondary slider 2 relatively moves in a direction approaching the fixed electrode.

[0047]

Next, the operation of the embodiment, which more specifically illustrates the first embodiment of the present invention, will be described in detail.

First, the flying characteristics of the main slider 1 and the secondary slider 2 were examined. For the measurement of the flying height, a flying height measuring device based on homodyne optical interferometry was used.
The minimum flying height of the main slider 1 and the secondary slider 2 (the flying height of the trailing edge portion) is a peripheral speed of 14 m / sec, s.
Under the conditions of a 0 ° kw angle and a load of 0 gf, they were about 0.15 μm and about 0.04 μm, respectively.

Next, the dynamic characteristics of the electrostatic drive type microactuator were evaluated (in the state of the actuator alone without setting the slider on the magnetic disk). All measurements were performed using a laser Doppler vibrometer (LDV). From the frequency response characteristics in the magnetic disk radial direction, the in-plane resonance frequency of the actuator was about 18 kHz. The maximum stroke is a voltage ± 35 V applied (2 kHz).
z operation), about 1 μm (± 0.5 μm), ± 0.5 V (2 kHz operation), about 0.5 μm (± 0.25 μm)
Met.

The vibration component in the direction perpendicular to the plane of the actuator is about 2% of the maximum stroke in the plane (when the maximum stroke in the plane is 1 μm, the vertical vibration component is 20 nm).
Met.

In addition, when the micro-actuator section performs a high-speed tracking operation (± 0.5 μm operation at 2 kHz),
Next, the flying height fluctuation of the slider 2 was examined. A differential laser Doppler vibrometer (LDV) is used for the measurement, the reference light is irradiated on the surface of the magnetic disk, the measurement light is irradiated on the back surface of the secondary slider 2, and both lights are subjected to heterodyne detection. Next, the relative fluctuation of the slider 2 was measured.

As a result, the maximum flying height variation of the secondary slider 2 from the steady flying state due to the high-speed operation of the microactuator is 10% or less of the steady flying height of the secondary slider 2 (4 nm or less at a peripheral speed of 14 m / sec). Was confirmed. As a result, about 2% (20 nm) of the maximum in-plane stroke originally possessed by the microactuator
Is reduced to 4 nm or less by the air bearing effect of the secondary slider 2.

As described above, according to the first embodiment of the present invention, the slider is composed of the main slider 1 having a relatively high flying height and the low flying type and ultra-small type 2 having the magnetic head element mounted thereon. The secondary slider 2 has a two-stage slider structure, and only the secondary slider 2 is minutely driven in the magnetic disk radial direction by a microactuator structure. Accordingly, since the structure including the magnetic head element to be driven by the microactuator (that is, the secondary slider 2) independently forms a magnetic head / magnetic disk medium spacing control system, the secondary slider 2 Only micro-actuator micro-actuator drives micro-actuator in the radial direction of the magnetic disk to suppress the fluctuation of the actuator in the vertical direction of the magnetic disk, which is harmful to the recording / reproducing characteristics when operating the micro-actuator driven by the magnetic head element. Can be.

[Other Modifications] In the above-described first embodiment of the present invention, the main slider 1 and the secondary slider 2 use negative pressure type sliders, and the main slider 1 has a nano size slider (50% slider). It was adopted. Also, 2
Next, an electrostatic drive system was adopted as a drive system of the slider 2.

First, from the viewpoint of the slider design, other modified examples described below are conceivable. In the above-described first embodiment, a negative pressure type slider is used for both the main slider 1 and the secondary slider 2. However, as an alternative method, both the two-stage sliders may be both positive pressure type sliders. Of course, the same effect as in the above-described first embodiment can be expected even if a mixed type in which one is a positive pressure type and the other is a negative pressure type. It is also possible to change the system of the main slider 1 from a nano slider to a pico slider (30% slider).

From the viewpoint of the drive system of the secondary slider 2, the following drive method can be considered as another modified example instead of the electrostatic drive type in the first embodiment.

As an example, there is an electromagnetic drive type having a large generating force. However, it is presumed that the structure becomes considerably complicated in the electromagnetic drive type due to the necessity of forming a coil. In addition, there is a concern about the influence of the generated field on a recording / reproducing system using electromagnetic conversion as its basic principle. As another example, a piezoelectric driving type, which has a problem in the long-term mechanical reliability of the material but can expect a large generating force like the electromagnetic driving type, is a candidate.

As described above, according to another modification of the present invention, both the main slider 1 and the secondary slider 2 have a positive pressure type, or a mixed type in which one of them is a positive pressure type and the other is a negative pressure type. Even if the micro-actuator drive system employs an electromagnetic drive type or a piezoelectric drive type, the same as in the first embodiment, the slider may be a main slider having a relatively high flying height, A two-stage slider structure including a low-flying and ultra-small secondary slider on which a magnetic head element is mounted, and only the secondary slider 2 is minutely driven in the radial direction of the magnetic disk by a microactuator structure, thereby driving the magnetic head element. The vertical movement of the actuator, which is harmful to the recording / reproducing characteristics when operating the micro-actuator It is possible.

In the above embodiment, the type of the magnetic head is not particularly limited, and the ferrite head, the MIG (Me
tal In Gap) head, Thin Film Head,
Thin-film ring head, MR (MagnetoRegistiv) distinguished from single pole head for perpendicular magnetic recording
e: Magnetoresistive type, GMR (Giant MagnetoRegistive)
Although any type may be used, if the present invention is a kind of floating slider, each head after the above-mentioned thin film head is suitable.

[0060]

As described above, according to the present invention, the slider is composed of the main slider having a relatively high flying height,
It has a two-stage slider structure including a low-flying and ultra-small secondary slider on which a magnetic head element is mounted, and only the secondary slider is minutely driven in the magnetic disk radial direction by a microactuator structure.

As a result, the structure including the magnetic head element to be driven by the microactuator (that is, the structure including
The next slider) forms its own magnetic head / magnetic disk medium spacing control system. Therefore, the actuator in the vertical direction of the magnetic disk, which is harmful to the recording / reproducing characteristics generated when a magnetic actuator driven microactuator is driven, Fluctuations can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view illustrating a configuration of a two-stage slider integrated with a microactuator according to a first embodiment of the present invention.

FIG. 2 shows a conventional microactuator using a slider /
1 is a schematic perspective view showing a head gimbal assay (HGA) of a type incorporated between suspensions.

FIG. 3 shows a conventional head having a microactuator formed by linking a magnetic head element and a slider.
1 is a schematic perspective view of a gimbal assay (HGA).

FIG. 4 is a head gimbal assay (HGA) of FIG.
It is the schematic perspective view which expanded the principal part of FIG.

FIG. 5 is a schematic perspective view of a conventional two-stage slider.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main slider 2 Secondary slider 3 Micro suspension 4 Comb electrode structure 5 Air bearing surface 6 Magnetic head element 7 Suspension 21, 31 Slider 26, 36 Suspension 27, 37 Micro actuator 28, 38 Magnetic head element 35 Air bearing surface

Claims (6)

[Claims] 1. A slider mechanism of a magnetic disk drive for writing and reading data on and from a magnetic disk, wherein the slider mounted on a suspension has a two-stage structure integrated with a microactuator and has a relatively high flying height; The secondary slider has a two-stage structure with a low-flying secondary slider supported by a trailing edge of the main slider and having a magnetic head element mounted thereon, and the secondary slider is minutely driven in the radial direction of the magnetic disk by the microactuator. A slider mechanism for a magnetic disk drive. 2. A slider mechanism for a magnetic disk drive according to claim 1, wherein an interface formed between a fixed electrode extending from said main slider and both side surfaces of said secondary slider has a comb-tooth electrode structure. 3. The magnetic disk drive according to claim 1, wherein the secondary slider is finely driven in a radial direction of the magnetic disk by using an electromagnetically driven microactuator structure, or the secondary slider is driven by a piezoelectrically driven microactuator structure. 3. The slider mechanism of a magnetic disk drive according to claim 1, wherein the slider mechanism is minutely driven in a radial direction. 4. The slider according to claim 1, wherein both the main slider and the secondary slider are negative pressure sliders, or both the main slider and the secondary slider are positive pressure sliders. A slider mechanism for a magnetic disk drive according to any one of the above. 5. The secondary slider, a microsuspension supporting the secondary slider, and a comb electrode structure supporting between the secondary slider and the main slider constitute a low-flying floating head system. 4. The slider mechanism according to claim 1, wherein the slider mechanism has a micro-actuator structure. 6. A magnetic disk drive having a slider mechanism in a magnetic head, wherein the slider mounted on a suspension has a two-stage structure integrated with a microactuator, and has a relatively high flying height, and a main slider. A low-flying secondary slider supported by the microsuspension at the trailing edge of the magnetic head element and having a low-flying type secondary slider, wherein a comb-shaped electrode is formed between the secondary slider and the main slider. A magnetic disk drive, wherein a slider is supported by the main slider.