JP3290569B2 - Thin-film magnetic head slider - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the f comprising an electrostatic actuator for driving the thin film magnetic head slider and its head element used in a magnetic disk device
Related to the slider .

[0002]

2. Description of the Related Art In recent years, with the miniaturization, high performance, and low price of magnetic disk drives, development of high performance and low price thin film magnetic heads has been desired. As a method that satisfies this requirement, a horizontal head (planar head) in which the thin film pattern deposition surface is parallel to the air bearing surface has been proposed. The reason is that the horizontal head is easy to form a floating rail with a specific shape, so that it is easy to realize a low flying head stably, and it is easy to reduce the number of machining parts, so it is easy to realize a low price It depends.

An example of a conventional horizontal magnetic head slider will be described below. IEEE TRANSACTIONS ON MAGNETICS, vol.25, p.319
0, 1989, “A New Thin Film Head
Generation) ”, JP Lazzari and P. Deroux-Dauph
In this conventional example, a dent is formed on the surface of a silicon substrate by etching, and a thin magnetic head element is formed in the dent. Since the surface of the silicon substrate is the floating surface facing the recording medium, in order to take out the terminal of the head to the back surface of the slider, a through hole penetrating the silicon substrate is formed and the terminal is drawn. The slider outer shape is formed by machining.

[0004] IEEE TRANSACTIONS ON MAGNETICS, vo
l.25, p.3686, 1989, “A New Approach to Making Thin
FilmHead-Slider Devices) ”, Daniel W. Chapman. In this conventional example, a thin film magnetic head element is formed on the substrate from the air bearing surface side first, the insulating film is flattened, and a glass substrate with a through hole penetrated is formed. The slider body is formed by bonding. After the substrate is removed by etching, the outer shape of the slider is cut by machining.

[0005]

In each of the above and the conventional examples, the outer shape of the slider must be formed by machining as in the past, the assembly with the support spring must be individually performed as in the past, and furthermore, the slider must be penetrated through the substrate. Steps such as forming a through hole to embed a conductor and bonding a glass substrate are required, and the process is complicated.

Therefore, the present invention can be easily manufactured without forming a through-hole or using a glass substrate, and can perform tracking of a thin-film magnetic head element (substantially perpendicular to the moving direction of a recording medium). By adding a mechanism for micro-moving in the tracking direction, or a mechanism for micro-moving in the direction approaching / separating from the loading / unloading recording medium, more accurate positioning of the magnetic head element is realized and high recording is achieved. It is an object of the present invention to provide a thin-film magnetic head slider for measuring the realization of the density and the improvement of the reliability.

Another object of the present invention is to provide a head slider provided with an electrostatic actuator suitable as a drive mechanism for adding a tracking mechanism or a load / unload mechanism in the above-described thin film magnetic head element. And

[0008]

According to the present invention, a slider film is formed on a surface of a substrate or a surface of a sacrifice layer provided on the substrate, and the substrate, or the substrate and the sacrifice layer are formed on the substrate. In a thin-film magnetic head slider separated from a slider film body, a tracking mechanism in which a part of the slider film body is supported on a fixed portion of the slider film body so as to be movable in a tracking direction substantially perpendicular to a moving direction of a recording medium. , And at least a facing magnetic pole of a thin-film magnetic head element facing a recording medium is provided on a movable portion of the tracking mechanism.

According to the present invention, a slider film is formed on a surface of a substrate or a surface of a sacrificial layer provided on the substrate, and the substrate or the substrate and the sacrificial layer are removed from the slider film. In the separated thin film magnetic head slider,
A load / unload mechanism that supports a part of the slider film on a fixed portion of the slider film so as to be movable in a load / unload direction approaching / separating from the recording medium; A thin-film magnetic head slider is provided, wherein at least a facing magnetic pole of a thin-film magnetic head element facing a recording medium is provided on a movable portion of a load mechanism.

As described above, according to the present invention, in addition to the mechanism for tracking the entire support spring, only the element portion can be tracked with high accuracy, so that the track density of the recording medium can be improved. Also, since only the element portion can be lowered, the linear recording density can be improved without deteriorating the reliability. Still further, according to the present invention, a fixed portion having a plurality of teeth parallel to each other, a movable portion having a plurality of teeth parallel to the teeth, and moving the movable portion relative to the fixed portion in a tooth width direction. Movable to the point where the electrostatic attraction in the tooth width direction generated by applying a voltage between the teeth of the fixed part and the movable part and the multiple force of the support spring are balanced. head slider is provided part and a drive force generation unit which is adapted to move the comprises a formed Ru electrostatic <br/> electrostatic actuator.

With the electrostatic actuator of the present invention, a force for moving the movable portion in the tooth width direction can be obtained, so that an electrostatic actuator with higher force generation efficiency than the conventional electrostatic actuator can be realized.

[0012]

1 (a) to 1 (c) show a first embodiment of a thin film magnetic head slider according to the present invention. FIG. 1 (a)
FIG. 1B is a perspective view of the slider 10 mounted on the support spring 30 as viewed from the air bearing surface, and FIG. 1B is a perspective view of the slider 10 itself mounted on the support spring 30 on the back side (opposite the air bearing surface). 1 (c) is a view showing a cross section taken along line BB 'in FIG. 1 (a).

On the side of the flying surface of the slider 10 facing a recording medium (not shown), a part of a flying surface layer 11 made of SiO ₂ , Al ₂ O ₃ or the like protrudes toward the medium, and an arrow A
End 13 to outlet 14 for media moving in
Two levitation rails 15 extending to are formed. Further, a center rail 17 is formed on the inflow end 13 side between these two floating rails 15. The main body 12 and the terminal pad portion 18 (FIG. 1B) of the slider 10 formed on the back surface of the flying surface layer 11 are formed by plating a metal such as Ni.

The element drive mechanism 20 (in this embodiment, a tracking mechanism) is provided between the two floating rails 15 and between the terminal pad 18 and the outflow end 14. Part is formed. That is, the plating (metal such as Ni) of the main body 12 of the slider 10 is not formed in the element drive mechanism 20. The length of the slider 10 from the inflow end 13 to the outflow end 14 is, for example, 0.5
~ 0.8mm, width 0.3 ~ 0.6mm, thickness 0.04 ~
0.06 mm.

The element drive mechanism, that is, the tracking mechanism 20 in the first embodiment utilizes electrostatic attraction as shown in the sectional view of FIG. 1C, and the movable element is fixed. It consists of two parallel springs 21 (only one is shown) extending from the part and an element mounting part 22 supported on the tip side thereof. The parallel spring 21 of the mover and the side of the stator 23 opposed thereto are made of a metal such as Ni or Cu. Alternatively, the mover and the stator have metal electrodes at opposing portions, and perform tracking by applying a voltage between the stator electrode 23 and the mover electrode 21 to generate an attractive force. It is.

The mover is provided such that only the head element 24 or the magnetic pole tip 24a of the element protrudes toward the medium (not shown), and the drive electrode portions 21 and 23 are set apart from the medium. This is because the drive unit does not affect the flying force of the slider 10 and thus does not attract dust around the head element 24 due to the voltage between the electrodes 21 and 23. Although not shown in the drawing, the flying surface side end of the outer periphery of the side surface of the slider 10 prevents collision with the medium when the attitude is changed due to rolling or pitching of the slider 10, or when the collision with the medium occurs. To prevent damage to
It is desirable to perform R chamfering.

There are two and four terminal pad portions 18 at the center of the back surface of the slider 10 to be connected to terminal connection portions (not shown) of the head suspension 30. Is for a tracking mechanism. still,
When the MR element is also used as the read head element, one set and two terminals are sufficient. 2A and 2B show a modified example of the tracking mechanism 20. FIG. In the modification of FIG. 2A, the stator electrode portion 23 shown in FIG.
And a curved surface on the surface facing the
1 is deformed along the curved surface of the fixed electrode portion 23, thereby increasing the amount of displacement. FIG.
In the modified example (b), tracking is performed by forming the mover 21 and the stator 23 with comb-tooth electrodes 21a and 23a parallel to each other and generating an attractive force in a direction parallel to the length direction of these comb teeth. This is an example of performing.

FIGS. 3A and 3B show a thin-film magnetic head slider according to a second embodiment of the present invention in which the tracking drive mechanism 20 is incorporated in one of the flying rails 15 itself. By incorporating the drive unit 20 into the rail 15 itself as in the present embodiment, it is possible to further increase the arrangement area of the terminal pads 18 or further reduce the size of the slider. In this embodiment, as the structure of the tracking drive mechanism 20, any of the structures shown in FIGS. 1C, 2A, and 2C can be adopted. However, as described above, the electrode portions 21 and 23 are formed slightly inside (on the side of the main body portion 12) from the surface of the floating rail 15 so as to be separated from the medium (not shown). It is desirable to have a structure that prevents discharge and the like.

FIGS. 4A and 4B show a thin film magnetic head slider (third embodiment) of the present invention having a load / unload mechanism. The position where the load / unload mechanism 20A is provided may be between the floating rails 15 as in the first embodiment, or may be incorporated in the floating rail 15 itself as in the second embodiment. In this embodiment, the spring 2 of the mover is used.
1 is formed above the flying surface layer 11 of the slider at a slight interval in the flying height direction, and a head element mounting portion 22 is formed at the tip of the spring portion 21. Floating surface layer 11
By applying a voltage between the fixed side electrode 23 and the movable side electrode 21, the movable element 21 is attracted to the air bearing surface layer side 11 to bring the head element 24 close to a medium (not shown). Or contact. The voltage application in this mechanism may be such that the energization is started immediately after the rotation of the recording medium is started, and the energization is stopped immediately before the stop of the medium, or the energization is performed in conjunction with the operation of the head element 24. Start and stop may be performed.

In the embodiment shown in FIGS. 1 to 4, a center rail is provided at the center on the inflow end 13 side of the slider 10 and both side rails are provided on both sides near the outflow end. When the generating section is formed, the tracking mechanism 20 or the load / unload mechanism 20A
Is preferably provided inside this triangle. The reason is that there are three floating force generating parts, so even if the slider itself is deformed due to residual stress or the like generated in each layer when forming the slider body or the floating surface layer, it is hard to be affected by the flying height fluctuation,
By arranging the drive mechanism and the head element inside the triangle having these three points as vertices, a stable flying height can be secured.

FIGS. 5A and 5B illustrate the principle of an electrostatic actuator that can be employed as a driving mechanism in the present invention in comparison with a conventional example. One of the two opposing comb teeth is a fixed part 31 and the other is a movable part 32. By applying a voltage between the two comb teeth, the movable part 32 is moved a small distance with respect to the fixed part 31. Such an electrostatic actuator includes, for example, Si _{3 serving as an} insulating layer on a silicon substrate provided with a thermal oxide film.
N ₄ film, PSG (phosphosilicate glass) to be a sacrificial layer
2) A 2 μm polysilicon film to be a film and a comb-shaped electrode is formed, the polysilicon is formed into a desired shape by plasma etching, and finally, the sacrificial layer is removed by wet etching to open the movable portion 32. Things.

In the conventional electrostatic actuator shown in FIG. 5 (a), the teeth on the movable portion 32 are arranged at intermediate positions between adjacent teeth on the fixed portion 31 and between two opposing comb-like electrodes. 5B, a force is generated in a direction in which the engagement length of the comb teeth is reduced, whereas the electrostatic actuator according to the present invention shown in FIG. The teeth on the movable portion 32 side are arranged at positions deviated from the intermediate positions of the teeth to generate a force in a direction perpendicular to the tooth surface. The difference between the conventional electrostatic actuator and the actuator according to the present invention will be described.

In the conventional actuator, the teeth on the movable portion 32 are arranged at intermediate positions between adjacent teeth on the fixed portion 31 to generate a force in the horizontal direction (X direction) in the figure. Assuming that the force Fx is g in the gap between the teeth of the fixed part 31 and the teeth of the movable part 32, t is the thickness of the teeth, V is the applied voltage, and ε ₀ is the dielectric constant in a vacuum, Is Fx = V ² ε ₀ t /
g.

On the other hand, in the electrostatic actuator according to the present invention, the gap between the teeth on the fixed part 31 side and the teeth on the movable part 32 has a narrow gap g ₁ and a wide gap g ₂ , and Y generated at g _1. In the direction (perpendicular to the tooth surface) and Y generated in g ₂
The difference in directional forces is the available force. Its size is Fy
_{^{= (1/2) V 2 ε 0}} tL (1 / g 1 2 -1 / g 2 2)
It is. and g ₁ = g, when the ^{_{1 / g 2 2 << 1 /}} g 1 2, is Fy / Fx ≒ L / 2g. When L> 2 g, the electrostatic actuator according to the present invention can obtain a larger force. For example, if a gap of g = 1 μm and a tooth of L = 200 μm are formed, 100 times the force of the conventional electrostatic actuator can be obtained. Here, the force generated at g ₂ acts in a direction to cancel the force generated at g ₁ , so it is better to make g ₂ larger than g _1. G ₂ /
The g ₁ there exists an optimum value. L compared to g ₁ , g ₂ , w
FIG. 6 shows the relationship between the generated force (Fy) and g ₂ / g ₁ when is sufficiently large. Since the number of teeth can only take an integer value, the graph is not smooth if L is not sufficiently large, but even in that case, the force becomes maximum around 2 <g ₂ / g ₁ <3. Practically, 1.5 <g ₂ / g ₁ <5,
Alternatively, it is better to use in the range of 1.2 <g ₂ / g ₁ <10.

FIG. 7 shows an embodiment of the electrostatic actuator of the present invention. The outer frame part is a fixed part 3 formed by Ni plating.
One main body is fixed on a substrate (not shown). On the inner wall of the fixing portion 31 main body, mutually parallel teeth 31a are provided at regular intervals toward the inner periphery by Ni plating at the same time as the fixing portion 31 main body. These teeth 31a may be fixed on the substrate, or may be provided with a gap (not shown) between the teeth 31a and the substrate. A central portion inside the frame of the fixed portion 31 is a movable portion 32 main body formed by Ni plating simultaneously with the fixed portion 31 main body, and has a gap (not shown) between the main body and the substrate.
It is provided to be able to move relative to the fixed part 31. Further, the movable portion 32 has a plurality of teeth 32a at positions deviated from the centers of mutually adjacent teeth 31a provided on the fixed portion 31 so as to be parallel to the teeth 31a. In the figure, columns 3 fixed to the substrate are above and below the movable portion 32.
3, a support spring 34 is provided between the column 33 and the main body of the movable part 32 so as to move the movable part 32 only in the vertical direction in the figure. Conductive wires 35 and 36 for connecting to terminals (not shown) are formed by Ni plating from the lower right and lower pillars of the fixing portion 31.

When a voltage is applied between the two conducting wires 35 and 36, the movable portion 32 is attracted upward by electrostatic attraction acting between the teeth 31a of the fixed portion 31 and the teeth 32a of the movable portion 32, and is supported. It moves to a position that balances the restoring force of the spring 34. Since the attraction force is proportional to the square of the potential difference, it moves in the same direction regardless of the polarity. However, it is better to ground the movable part 32 so that the driven object (the thin film magnetic head in the present invention) mounted on the movable part 32 is not affected by the drive noise.

In order to prevent the teeth 31a of the fixed part 31 and the teeth 32a of the movable part 32 from contacting each other and short-circuiting when an excessive voltage is input, the movable part 32
And a stopper 37 is provided. The stopper 37, that is, the column 33 has the same potential (ground) as the movable portion 32, and there is no problem even if the stopper 37 contacts the movable portion 32.

Next, a method for manufacturing the electrostatic actuator of the present invention will be described with reference to FIGS. These figures show AA cross sections in FIG. First, in FIG. 8, (a) a thermal oxide film T-SiO ₂ is attached to both surfaces (100)
An Si substrate is used. (B) Only the portions of the main body of the movable portion 32, the teeth 32a of the movable portion 32, and the teeth 31a of the fixed portion 31 and the support springs 34 are formed using a mask by ion milling or the like using a thermal oxide film T- on the substrate surface. The SiO ₂ is removed. (C) An Al film is formed as a sacrificial layer on the substrate surface by vapor deposition or sputtering. (D) Except for the portion from which the thermal oxide film T-SiO ₂ has been removed, the remaining portion of the Al sacrificial layer is removed by ion milling or the like. In this case, a small gap is formed at the boundary between the Al sacrificial layer and the thermal oxide film. (E) Ni is formed on the entire surface as a base layer for plating by vapor deposition or sputtering. The underlayer also penetrates into the gap.

Next, in FIG. 9, (a) a photoresist is applied and the fixing portion 3 in FIG.
1. movable part 32, support spring 34, stopper 37, support 3
3. Pattern the negative mold for forming the conductive wires 35 and 36 by Ni plating. (B) Fill Ni-free portions without photoresist by Ni plating. (C) removing the photoresist with a solvent; (D) By ion milling the entire surface, a portion of the underlayer not covered with Ni is removed. This step may of course be performed after patterning a protective photoresist (not shown) having the same shape on the plated Ni, instead of performing the entire surface ion milling. (E) By removing the Al in the sacrificial layer with the KOH solution, the movable part 32 is separated from the substrate and can be moved relative to each other.
Since the thermal oxide film T-SiO ₂ has been removed from the movable portion 32, the Si of the substrate is also dissolved, the KOH solution easily enters, and the etching time is shortened.

FIG. 10 shows another embodiment of the electrostatic actuator of the present invention. This embodiment is different from the embodiment of FIG. 7 in that the first teeth 31a of the fixed part 31 and the second teeth 3 of the fixed part 31 are equally spaced on both sides of the teeth 32a of the movable part 32.
1b is provided. By the insulating layer 38 shown in the figure, the first teeth 31a and the second teeth 32b of the fixing part 31 are electrically insulated from each other, and different voltages can be applied. When the movable part 32 is electrically grounded and a voltage is applied to the first teeth 31 a of the fixed part 31, the movable part 32 moves upward in the figure. When a voltage is applied to the second teeth 31 b of the fixed part 31, the movable part 32 is moved. Moves down in the figure. According to the structure of this embodiment, the movable portion 32 can be moved upward and downward in the drawing, and the stroke is doubled as compared with the embodiment of FIG.

Next, examples of applying a voltage to the first teeth 31a and the second teeth 31b of the stator 31 in the embodiment of FIG. 10 are shown in FIGS. 11 (a) to 11 (c). The direction of the force F is positive in the upward direction in the figure. (A) is an example applied positive the voltages V ₁ to the first tooth 31a, a negative voltage is applied to V ₂ in the second tooth 31b when to generate a downward force when generating an upward force. (B) is multiplied by a positive to voltages V ₁ to the first tooth 31a when generating an upward force, it applies a positive voltage V ₂ to the second tooth 31b when to generate a downward force.
(C) shows the first and second teeth 31a, 31 of the fixed part 31.
This is an example in which an offset voltage of の of the maximum voltage is applied to b, and voltages V ₁ and V ₂ having opposite phases are superimposed and driven. When V ₁ = V ₀ + ΔV and V ₂ = V ₀ −ΔV, F
^{_{yαV 1 2 -V 2 2 = 4V}} 0 ΔV , and the force becomes proportional to [Delta] V, be easily controlled. The advantages of such a voltage application method are that it can be driven only by a single power supply and that it can be driven with the movable part electrically grounded.

As a preferable application example of the electrostatic actuator of the present invention, it is preferable to incorporate the electrostatic actuator as a drive unit of the above-described tracking mechanism or load / unload mechanism in a head slider of a magnetic disk drive. FIG. 12 shows an example of such a head slider. This slider 10
The horizontal thin film magnetic head element 24, the flying surface layer 11, and the slider body 12 are formed by a series of processes, and are bonded to the head suspension 30. In a magnetic disk drive, a head suspension on which a head slider 10 is mounted is sought and positioned by a voice coil motor. In addition, a micro actuator (a tracking mechanism in this embodiment) is mounted in the head slider, and a thin film is formed. If the magnetic head element 24 is controlled in a high band, the positioning accuracy is further increased, and the recording density can be increased. In the present invention, a horizontal head (also called a planar head) 24 and a floating surface layer (SiO ₂ ) 11 are formed on a substrate via a sacrificial layer, as described later, in order to reduce machining and reduce manufacturing costs. After the slider body 12 is formed by Ni plating, the sacrificial layer is removed to separate the slider portion 10 from the substrate. Further, the head slider 10 has a drive mechanism section 20 of an electrostatic actuator that minutely drives the element portion 24 in the tracking direction.

FIG. 13 shows a sectional structure of the head slider 10. As shown in FIG. A sacrificial layer 41 conforming to the shape of the air bearing surface is formed of Al on the substrate 40, the horizontal head element 24 is formed thereon, and then SiO ₂ to be the air bearing surface layer 11 is formed. This surface is a surface that becomes a sliding surface or an air lubricating surface with a recording medium (not shown). In the figure, a layer 42 indicated by a black line is a conductor pattern layer (Au) for connecting each part of the head element and the electrostatic actuator to a terminal, and an insulating layer (Si).
O ₂ ) and a plating underlayer (Ni). Then, the movable portion 43, the fixed portion 44, the support spring portion (reference numeral 34 in FIG. 7) and the like of the electrostatic actuator are formed simultaneously with the slider body 12 and the terminals 18 by Ni plating. Thereafter, plating may be added to increase the rigidity of only the slider body except for the actuator movable portion 43. Thereafter, an Au bonding layer 45 is formed and patterned on the uppermost surface, bonded to the head suspension 30 as shown in FIG. 12, and the head slider 10 is separated from the substrate 40 by dissolving the sacrificial layer 41 with a KOH solution.

The read signal of the magnetic disk device is on the order of mV, whereas the drive voltage of the electrostatic actuator is several tens of volts. There is a concern that the drive of the actuator may affect the read signal. The movable part 43 on which the head element 24 is mounted can be grounded as described above, and the signal line from the head element 24 to the terminal 18 is arranged via the insulating layer below the movable part 43. Through the conductor pattern, the actuator movable part 43 and the fixed part 44
Can be carried out along the support spring 34 (FIGS. 7 and 10) that connects. Since the support spring 34 is also grounded, the signal line is shielded and a structure that is less susceptible to noise can be obtained.

FIGS. 14 to 17 show embodiments in which electrostatic actuators acting in both the tracking direction and the load / unload direction are incorporated in a head slider, all of which show enlarged thickness directions. 14 is a perspective view of the head slider viewed from the air bearing surface side, FIG. 15 is a cutaway view of an electrostatic actuator unit incorporated inside the head slider, and FIGS. 16 and 17 are each an arrow A diagram of FIG.

In these figures, 10 is a head slider, 11 is a floating surface layer (SiO ₂ ) facing the medium, 12
Is a slider body (Ni), 15 is both side rails (pressure generating pads), 17 is a center rail (pressure generating pads), 18
Is a terminal, 51 is a fixed portion, 52 is a movable portion on which a head element is provided, 53 is a column, 54 is a supporting spring portion for supporting the movable portion 52, 55 is an insulating layer, 56 is an electrode, and 57 is provided on both side rails 15. The projection 58 protruding toward the medium is a surface lubrication layer (DLC).

In this embodiment, the movable portion 52 is disposed inside a triangle formed by the three pressure generating pads 15 and 17, and the movable portion 52 is positioned in the lateral direction X with respect to the fixed portion 51 in the medium moving direction A.
It is supported by the support spring 54 so as to be movable in the (tracking direction) and also in the vertical direction Z (load / unload direction). The fixed portion 51 and the movable portion 52 include a plurality of parallel teeth 51 as in the embodiment of FIG.
a, 52a, and the teeth 52a of the movable part are arranged at a position deviated from the center of two teeth 51a adjacent to the fixed part. 52 moves in the X direction with respect to the fixed portion 51 to a position where the electrostatic attraction force and the restoring force of the support spring portion 54 are balanced.

The movable portion 52 further resists the support spring portion 54 by electrostatic attraction acting on the movable portion 52 by applying a voltage to an electrode 56 provided on the fixed portion facing the flat portion of the movable portion. Then, it moves minutely also in the Z direction. Therefore, the support spring portion 54 supports the movable portion 52 so as to be movable in the Z direction. In the embodiment of FIG. 16, the protrusion 57 itself is made of a surface lubricant (DLC) to improve the lubricity between the head slider 10 and the medium. In the embodiment shown in FIG. 17, the protrusions 57 themselves are formed as a part of the floating surface layer 11 (SiO ₂ ), and the entire floating surface layer 11 including the protrusions 57 is covered with a surface lubrication layer 58 (DLC). Things.

In this embodiment, as shown in FIG. 14, the shape of the slider main body and the shape including the obtuse portion are substantially polygonal prism shapes. This is to reduce the weight by removing functionally unnecessary portions on both sides of the central pressure generating pad from the rectangular parallelepiped, and to reduce the probability of collision with the medium due to the rolling or pitching operation of the head slider. Further, by performing R chamfering on the outer periphery of the slider and the outer periphery of the pressure generating pad, even if a collision with the medium occurs, damage to the medium can be reduced. The same effect can be obtained with C chamfering instead of R chamfering.

Since the head slider of the present invention does not require machining, and is manufactured by a process mainly using photolithography, it is possible to deal with such fine shapes without increasing the number of processing steps and costs. This embodiment is an example in which a tracking actuator, a flying direction drive actuator, and a REIT / write common head (inductive head) are mounted. The two electrostatic actuators require a total of three terminals with the movable part at a common potential (ground), and the head requires two terminals. In this embodiment, the actuator movable portion is set to the same potential as the slider main body, and the slider main body is used as one terminal and connected to the conductor pattern on the head suspension together with the four terminals shown.

FIG. 18 shows an embodiment of a head slider using a piezoelectric material for the drive section. A mechanism 20 for minutely driving the head is provided in a part of the slider. The head driving unit 20 is mounted in a beam shape so as to support the head unit 24 mounted on the tip (head mounting unit 22). A piezoelectric thin film such as ZnO or PZT is laminated on the beam, and the head is moved by minute displacement of the piezoelectric thin film.

The head drive section 20 is not exposed on the floating surface, but is located on the upper surface side of the floating portion. Head 2
Reference numeral 4 indicates that the magnetic pole portion 24 is exposed only on a part of the air bearing surface, and reading / writing of the medium surface (not shown) is performed there.
The drive unit 20 for moving the head will be described. As described above, the piezoelectric element 24 is laminated in a thin film shape on the element mounting part 22 of the beam part supporting the head.

FIG. 18D shows the beam of the drive unit 20 enlarged.
61 is a cross-sectional view.
Layer (Al), 62 is a carbon film, 6
3 is a head wiring, 64 is a shield, 65 is a piezoelectric lower electrode.
The pole, 66 is ZnO which is a material of the piezoelectric thin film, and 67 is SiO
_TwoLayer, 68 is a piezoelectric upper electrode, 69 is an upper protective layer (SiO 2).
_Two).

The piezoelectric upper electrode 68 is divided into two parts (68a, 68b) from the center as shown in FIG.
5 is the ground side, one electrode 68a and the other electrode 6a
By applying an opposite-phase voltage to 8b, a minute displacement of the opposite phase occurs on the left and right of the beam. Thereby, the head 24
Is slightly displaced in the direction of the arrow in FIG. Piezoelectric thin film 6
PZT can also be used as 6;
An nO film is used. The advantages of the ZnO film are as follows: (1) A stable film having an orientation can be formed by sputtering or the like.

(2) A film can be formed at a lower temperature than PZT. (PZT: 600 ° C., ZnO: 200 ° C. or less) (3) The piezoelectricity is determined by the orientation of the film, and does not require a polarization treatment unlike PZT. (4) It is a film with a high track record used in products marketed as SAW filters and the like. There is. The disadvantages are as follows.

(1) The piezoelectric constant is lower than that of PZT. (2) It is easily soluble in acids and alkalis. In order to prevent the ZnO thin film from being easily dissolved in acid and alkali, which is a disadvantage of the ZnO thin film, the ZnO thin film is hardly dissolved when the sacrificial layer (Al) 61 is etched.
As shown in (d), the ZnO film 66 is formed as an electrode material 65,6.
It is preferable to adopt a structure covered with 8 or SiO ₂ 67 or the like.

FIG. 19 shows another embodiment of the drive unit using a piezoelectric material. In this embodiment, the structure is such that the ZnO piezoelectric thin film 66 is covered with a film 69 such as SiO ₂ from above and below the electrodes 65 and 68. Further, if there is a minute bore in the piezoelectric thin film 66, there is a risk of causing dielectric breakdown between the upper and lower electrodes 65 and 68. Therefore, as shown in the embodiment of FIG. Or the lower surface is electrode 6
SiO ₂ thinner than the piezoelectric film 66 inside 5, 68
It is desirable to provide a dielectric breakdown prevention film 67 such as this.

The smaller the width of the beam of the drive unit formed by the piezoelectric film 66, the greater the displacement. That is, Z
The smaller the thickness of the nO thin film 66, the greater the electric field strength per supply voltage, and thus the larger the displacement. However, due to the risk of dielectric breakdown, the maximum supply voltage will be ± 50V. The dimensions such as the width and the thickness of the beam have a great relationship with the resonance frequency of the beam. In general, the resonance frequency is reduced by making the beam portion thinner or thinner. Therefore, each dimension is restricted by the balance between the displacement amount and the resonance frequency.

As a method of minimizing the reduction of the displacement and securing the rigidity of the beam in the flying direction, it is conceivable to provide a columnar structure at the center of the beam width. Such an embodiment is shown in FIG. N only at the center of the beam width
By having the columnar structure 70 of i, the rate of hindering movement in the tracking (arrow X in FIG. 20) direction is relatively small, but the rigidity in the floating (arrow Z in FIG. 20) direction is significantly improved.

In the drive unit using the piezoelectric film shown in FIGS. 18 to 20, the head 24 is moved in the tracking (X) direction by applying a reverse phase voltage to the upper electrode 68a, 68b divided into two parts. Can be positioned by slightly moving the upper electrodes 68a, 6b.
By applying an in-phase voltage to 8b, minute movement in the flying (Z) direction can be performed.

FIG. 21 shows a case where a minute displacement is made in the tracking (X) direction, and FIG. 22 shows an operation principle for making a small displacement in the flying (Z) direction. In the case of FIG.
By making the thicknesses of the upper layer 71 and the lower layer 72 sandwiching the thin film 66 different, in a cross section including the piezoelectric film, the neutral axis does not coincide with the center of the piezoelectric film and shifts upward. When the piezoelectric film is expanded and contracted in this configuration, the beam bends in the Z direction, and the desired Z
Direction displacement (load / unload direction) is obtained. Even if the upper layer 71 and the lower layer 72 have the same thickness, an effect of shifting the neutral axis upward due to the presence of the columnar structure as shown in FIG. 20 can be expected. In actual driving, it is preferable that both tracking correction and load / unload air gap correction can be performed. In FIGS. 21 and 22, the beam is significantly exaggerated compared to the actual displacement of the beam for convenience of explanation.

[0052]

According to the present invention, the structure and manufacturing process of the head slider are simple, and a mechanism for tracking the head element portion or a load / unload mechanism can be incorporated. It is possible to provide the thin film magnetic head slider described above. It is also possible to increase the density of the recording medium.

Also, the electrostatic actuator of the present invention provides a force for moving the movable portion in the tooth width direction.
An electrostatic actuator having a higher force generation efficiency than a conventional electrostatic actuator can be realized. By mounting this on the head slider, the head slider and the electrostatic actuator are integrated while maintaining the manufacturing consistency, there is no need for machining, and the head can be positioned with submicron accuracy over a stroke of about 1 μm. It is possible to obtain a precise head slider that can be performed.

[Brief description of the drawings]

FIGS. 1A to 1C show a first embodiment of a thin-film magnetic head slider according to the present invention, wherein FIG. 1A is a perspective view seen from a floating surface side, and FIG. Perspective view from the side,
(C) shows a tracking drive mechanism section of the head element in a BB 'section.

FIGS. 2A and 2B show modifications of the tracking drive mechanism shown in FIG. 1C.

FIGS. 3A and 3B show a second embodiment of the thin-film magnetic head slider according to the present invention, wherein FIG. 3A is a perspective view as viewed from the floating surface side, and FIG. It is the perspective view seen from the side.

FIGS. 4A and 4B are a sectional view and a longitudinal sectional view corresponding to FIG. 1C of the load / unload drive mechanism.

FIGS. 5A and 5B are diagrams showing a conventional example of an electrostatic actuator and the principle of the present invention.

FIG. 6 is a graph showing the operation of the electrostatic actuator of the present invention.

FIG. 7 is a plan view showing an embodiment of the electrostatic actuator of the present invention.

8 (a) to 8 (e) are explanatory views showing the first half of the step of forming the electrostatic actuator of the present invention in the order of steps.

9 (a) to 9 (e) are explanatory views showing the latter half of the step of forming the electrostatic actuator of the present invention following the step of FIG. 8 in the order of steps.

FIG. 10 is a plan view showing another embodiment of the electrostatic actuator of the present invention.

11 (a) to 11 (c) show examples of applying electricity to the electrostatic actuator according to the embodiment of FIG.

FIG. 12 is a perspective view of a head slider incorporating an electrostatic actuator.

FIG. 13 is a sectional view of a head slider incorporating an electrostatic actuator.

FIG. 14 is a perspective view of a head slider in which an electrostatic actuator that minutely moves in a tracking direction and a load / unload direction is incorporated.

FIG. 15 is a sectional view of an actuator driving section of the head slider in FIG. 14;

16 is a diagram (a) of an arrow A of the head slider of FIG. 14;

FIG. 17 is an A-arrow diagram (b) of the head slider of FIG. 14;

FIGS. 18 (a) to 18 (d) show an embodiment of a head slider using a piezoelectric material for a drive unit, FIG. 18 (a) is a perspective view of the head slider viewed from the floating surface side, and FIG. FIG. 2C is a rear view, FIG. 2C is an AA cross-sectional view of FIG. 2A, and FIG. 2D is an enlarged cross-sectional view of a driving unit.

FIG. 19 is an enlarged cross-sectional view corresponding to FIG. 18D, showing another embodiment of the driving unit using a piezoelectric material.

FIG. 20 shows still another embodiment of the drive unit using a piezoelectric material.

FIGS. 21A and 21B are diagrams illustrating an operation when a driving unit is driven in a tracking direction using a piezoelectric material, and FIG.
Is a top view, and (b) is a beam sectional view.

FIG. 22 shows a method of loading a drive unit using a piezoelectric material.
FIG. 9 is a diagram for explaining an operation when driving in the unload direction.
(A) is a sectional view in the beam side direction, and (b) is a beam sectional view.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Slider 11 ... Floating surface layer 12 ... Slider main body 13 ... Inflow end 14 ... Outflow end 15 ... Both rails 17 ... Center rail 20 ... Tracking mechanism 21 ... Parallel spring (movable side electrode) 21a ... Movable part tooth (movable) 22 ... Head mounting portion 23 ... Fixed portion (fixed side electrode) 23a ... Fixed portion tooth (fixed side electrode) 24 ... Head element 30 ... Head suspension 31 ... Fixed portion 31a ... Fixed portion tooth (fixed side electrode) 32 movable part 32a movable part teeth (movable side electrode) 33 support column 34 support spring 35, 36 conductive wire 37 stopper 40 substrate 41 Al (sacrifice layer) 42 plating base, insulating layer, conductor pattern Layer 43: movable portion 44: fixed portion (12: slider body) 45: Au (bonding layer) 51: fixed portion 51a: fixed-side teeth 52: movable portion 52a: movable side Teeth 53 ... Support 54 ... Support spring 55 ... Insulating layer 56 ... Electrode 57 ... Protrusion 58 ... Surface lubrication layer (DLC) 61 ... Sacrifice layer (Al) 62 ... Carbon film 63 ... Head wiring 64 ... Shield 65 ... Lower electrode 66 ... Piezoelectric film (ZnO) 67: SiO ₂ 68: Upper electrode 69: Upper protective layer (SiO ₂ ) 70: Columnar structure (Ni plating)

Continuation of the front page (56) References JP-A-3-292610 (JP, A) JP-A-7-73619 (JP, A) JP-A-6-103597 (JP, A) JP-A-3-256215 (JP) , A) JP-A-5-282823 (JP, A) JP-A-7-141815 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 5/60 G11B 5/31 G11B 21/21

Claims (12)

(57) [Claims] 1. A thin film magnetic device comprising: a slider film formed on a surface of a substrate or a surface of a sacrificial layer provided on the substrate; and separating the substrate or the substrate and the sacrificial layer from the slider film. The head slider includes a tracking mechanism that supports a part of the slider film body on a fixed portion of the slider film body so as to be movable in a tracking direction substantially perpendicular to the moving direction of the recording medium. A thin film magnetic head slider provided with at least a facing magnetic pole of a thin film magnetic head element facing a recording medium. 2. A thin film magnetic device comprising: a slider film formed on a surface of a substrate or a surface of a sacrificial layer provided on the substrate; and separating the substrate or the substrate and the sacrificial layer from the slider film. The head slider includes a load / unload mechanism that supports a part of the slider film on a fixed portion of the slider film so as to be movable in a load / unload direction approaching / separating from the recording medium, A thin-film magnetic head slider characterized in that at least a facing magnetic pole of a thin-film magnetic head element facing a recording medium is provided on a movable portion of the load / unload mechanism. 3. A pressure sensor according to claim 1, wherein three pressure generating pads are provided on a surface of the slider film body facing the recording medium, and the movable portion is disposed inside a triangle formed by the three pressure generating pads. The head slider according to claim 1 or 2, wherein 4. The movable portion is supported by the fixed portion via a support spring portion, and a voltage is applied between at least opposing surfaces of the movable portion and the fixed portion, and a voltage is applied between these opposing surfaces. 2. A driving force generating section for driving said movable section with respect to said fixed section against a spring restoring force of said supporting spring section using an acting electrostatic attraction force. 3. The head slider according to 2. 5. The fixed part having a plurality of teeth parallel to each other, the movable part having a plurality of teeth parallel to the teeth, and the movable part being movable in a tooth width direction with respect to the fixed part. Movable to the point where the electrostatic attraction force in the tooth width direction generated by applying a voltage between the teeth of the fixed portion and the movable portion and the restoring force of the support spring are balanced. The head slider according to claim 4, further comprising: the driving force generating unit configured to move the unit. 6. The fixing portion has a plurality of first teeth parallel to each other and a plurality of second teeth parallel to the first teeth, wherein the first teeth are the second teeth. And each of the plurality of teeth of the movable portion is disposed between the first tooth of the fixed portion and the second tooth of the fixed portion, and is disposed between the first tooth of the movable portion and the first tooth of the fixed portion. A voltage is applied between the movable part and the second tooth of the fixed part to generate forces in directions opposite to each other in the width direction of the teeth or forces in a cooperating direction. A head slider according to item 1. 7. The movable section has a plurality of first teeth parallel to each other and a plurality of second teeth parallel to the first teeth, and the first and second teeth are insulated from each other. And
And, the teeth of the fixed part are arranged so as to be positioned in parallel between the first teeth and the second teeth of the movable part, and the second teeth of the movable part are located between the first teeth of the movable part and the fixed part. 6. A voltage is applied between the tooth and the fixed portion to generate forces in directions opposite to each other in the width direction of the teeth or forces in directions cooperating with each other.
A head slider according to item 1. 8. The head slider according to claim 1, wherein a driving mechanism for driving the movable portion with respect to the fixed portion is constituted by a piezoelectric element. 9. The head slider according to claim 8, wherein the piezoelectric element has a structure in which a piezoelectric film is sandwiched between upper and lower electrode layers in a flying direction of the slider with respect to a recording medium. 10. The head slider according to claim 9, wherein the upper and lower electrode layers sandwich a piezoelectric film and an insulating film. 11. A state in which a plurality of teeth of a fixed portion and a movable portion are respectively arranged at an equal pitch and no voltage is applied.
5. The head slide according to claim 4 , wherein the teeth of the movable part are arranged off center from the teeth of the fixed part.
Da. 12. The method of claim 11, wherein the supporting spring part is configured to support so as to be movable in the tooth width direction with respect to the fixed portion of the movable portion, and also movable in a second direction substantially perpendicular to the tooth width direction And a conductor portion is disposed on both sides of the movable portion in the second direction, and a voltage is applied between the conductor portion and the movable portion, thereby utilizing electrostatic attraction. 6. The head slider according to claim 5 , wherein the head slider is configured to be able to move slightly in the second direction.