JP2002373475A - Magnetic head positioning mechanism and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic head positioning mechanism, where a film thickness necessary for the bonding of a piezoelectric element is secured, to facilitate joining of a wiring from a drive source to a bonding pad. SOLUTION: In the magnetic head positioning mechanism provided with an offset correction mechanism in the suspension of a magnetic head, the electrode 6 of a piezoelectric element 3 provided in the offset correction mechanism is formed by a conductive film, and a bonding pad 10 is disposed on this conductive film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a magnetic head positioning mechanism and a method for manufacturing the same.

[0002]

2. Description of the Related Art A magnetic head is supported by a head arm which is reciprocally oscillated by a rotary actuator or a linear actuator in a radial direction of a recording disk, and records / reproduces data to / from a track of the recording disk. Used to perform

A magnetic head positioning mechanism positions a magnetic head with respect to a track on a recording disk by using a rotary actuator or a linear actuator.

Recently, in order to cope with the increase in track density of a recording disk, a configuration has been developed in which a mechanism for correcting off-track in which the magnetic head is shifted in the radial direction of the recording disk is provided in a magnetic head positioning mechanism.

In the off-track mechanism, as shown in FIG. 4, a pair of piezoelectric elements 3 are mounted on a suspension 2 on which a slider 1 of a magnetic head is mounted. 4
Is a connection portion for electrical connection fixed to a head arm reciprocated by a rotary actuator or a linear actuator.

[0006] The polarization directions of the piezoelectric elements 3, 3 are aligned in the plate thickness direction and are set in opposite directions.

As shown in FIG. 3, the piezoelectric element 3 has a piezoelectric material 5 and electrodes 6, 6 formed on an end face of the piezoelectric material 5 facing the film thickness direction, and a driving source is provided between the paired electrodes 6, 6. By applying a drive voltage from 7, a structure is generated in which distortion occurs in the length direction.

A slit 2a is provided in the suspension 2 on which the paired piezoelectric element 3 is mounted, and one end of the paired piezoelectric element 3 is extended and the other is shortened, so that the tip of the suspension 2 is recorded. Offset correction is performed by fine adjustment in the radial direction of the disk.

In the magnetic head positioning mechanism, a wiring 7 a from a driving source 7 is joined to one electrode 6 of the piezoelectric element 3 via a bonding pad 8. In addition, the other electrode 6 is generally connected directly to the suspension 2 with the conductive adhesive 9, and it is not necessary to use a bonding pad.

In FIG. 3, the reason why the gold material is used for the electrode 6 and the bonding pad 8 of the piezoelectric element 3 is as follows. That is, since the surface of the gold material is unlikely to be naturally oxidized, if the gold material is adhered to the end surface of the piezoelectric material 5, the end surface of the piezoelectric material 5 is covered and rust-proofed. The voltage on the entire surface of the electrode 6 becomes uniform,
Also, when bonding a gold ball using ultrasonic waves, gold is the best film to be bonded with the gold ball.

Here, it is impossible to firmly form a gold material directly on the end face of the piezoelectric material 5 by a sputtering method because the adhesion between the gold film and the piezoelectric material 5 is poor and cannot be achieved. In order to form the gold electrode 6, a base layer of Ni or Cr is formed on the end surface of the piezoelectric material 5, and the gold electrode 6 is formed on the base layer.

Therefore, a film thickness necessary for the electrode 6 is obtained by the Ni.Cr underlayer and the gold thin film formed by sputtering.

On the other hand, when gold bonding is performed using ultrasonic waves, the gold bonding pad 8 needs to have a certain thickness. If the film thickness is small, the gold ball is not firmly bonded. In order to increase the film thickness of the bonding pad 8, it is necessary to increase the sputter rate from the viewpoint of productivity. However, when the sputter rate is increased, the temperature increases, and the piezoelectric element 3 is deteriorated. As shown in FIG. 6A, a plurality of piezoelectric elements 3 are formed on a single substrate 12 and then cut into a strip shape shown in FIG. It is. In this case, a highly ductile material such as gold is hard to be cut by the grindstone 13 or the like. When the material is thickened, the burrs 3a are formed on the cut end face of the piezoelectric element 3 as shown in FIG.
May occur. Since the generated burr 3a falls off easily, the burr 3a that has fallen causes damage to the surface of the magnetic disk.

From the above, there is a limit to increasing the thickness of the bonding pad 8 in terms of the reliability and cost of the piezoelectric element, and it is difficult to join the wiring 7a from the driving source 7 to the bonding pad 8. There is a problem.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic head positioning mechanism and a method for manufacturing the same, which facilitate the joining of wiring from a driving source to the bonding pad by securing a necessary film thickness for the bonding pad of the piezoelectric element. To get.

[0016]

SUMMARY OF THE INVENTION To achieve the above object, a magnetic head positioning mechanism according to the present invention is a magnetic head positioning mechanism having a magnetic head suspension provided with an offset correction mechanism, wherein the offset correction mechanism has a piezoelectric element. The electrode of the piezoelectric element is formed of a conductive film, and a bonding pad formed by conductive plating is provided on the conductive film.

It is preferable that the bonding pad is formed so as to be closer to a portion of the surface of the electrode where the piezoelectric element is attached to the suspension. Further, it is preferable that the bonding pad is formed to be spaced inward from an edge of the electrode.

Further, the bonding pad may be formed of gold plating or conductive resin. Preferably, the conductive film of the electrode is a transparent conductive film, particularly, an ITO film.

According to a method of manufacturing a magnetic head positioning mechanism according to the present invention, there is provided a method of manufacturing a magnetic head positioning mechanism having an offset correcting mechanism in a suspension of a magnetic head, wherein electrodes of the piezoelectric element provided in the offset correcting mechanism are electrically conductive. The method includes a step of forming a film and a step of forming a bonding pad on the conductive film.

It is preferable that the bonding pad is formed so as to be closer to a portion of the surface of the electrode where the piezoelectric element is attached to the suspension. It is preferable that the bonding pad is formed to be spaced inward from an edge of the electrode. Preferably, the bonding pad is formed of a gold plating film.

[0021]

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

FIG. 1A is a sectional view showing a main part of an offset correction mechanism of a magnetic head positioning mechanism according to an embodiment of the present invention, and FIG. 1B is a plan view of the same.

As shown in FIG. 4, the offset correction mechanism of the magnetic head positioning mechanism uses two piezoelectric elements 3, 3 as a set. FIG. 1A shows one of the elements mounted on a suspension. 1 is shown in cross section, the structure of the other piezoelectric element forming the set is also the same as that of FIG.

The suspension 2 of the magnetic head is provided with a slit 2a along the track (arc) direction in which the data of the recording disk is written.
Electrodes of piezoelectric material 5 (lower electrode) at both ends in the length direction
Both ends in the length direction 6 are held and fixed to the suspension 2 by a conductive resin 9 across the slits 2a. The lower electrode 6 of the piezoelectric material 5 is electrically connected to a conductive pattern formed on the suspension 2 or a stainless steel suspension itself via a conductive resin 9.

In the piezoelectric element 3, a driving voltage is applied between a pair of electrodes 6 from a driving source (see FIG. 3), and accordingly, an electric field is generated between the pair of electrodes 6, 6, and the electric field is generated. This causes the piezoelectric material 5 to be distorted in the longitudinal direction due to distortion, and the suspension 2 is swung in the radial direction of the recording disk by the interaction of the paired piezoelectric elements 3. Work.

The piezoelectric element 3 of this embodiment comprises a piezoelectric material 5
At least one electrode 7b of a pair of electrodes 6, 6 arranged opposite to each other in the plate thickness direction is formed of a transparent conductive film. In the piezoelectric element 3 shown in FIG. 1A, the electrode 6 located on the upper surface of the piezoelectric material 5 is formed of a transparent conductive film, but the electrode 6 located on the lower surface of the piezoelectric material 5 is formed of a transparent conductive film. It may be formed.

In the embodiment shown in FIG. 1, at least one electrode (upper electrode) 6 of the piezoelectric material 5 is formed of a thin conductive film. Here, when an ITO film that is a transparent conductive film is used as the conductive film, the ITO film is formed on the upper surface of the piezoelectric material 5 by a sputtering method, and the formed ITO film is formed into a shape of the electrode 6. The electrode 6 is formed by performing the panning. The ITO film is formed on the piezoelectric material 5 without forming a Ni / Cr underlayer on the upper surface of the piezoelectric material 5.
Is formed directly on the upper surface of the substrate. In order to use a gold film as the conductive film, a lower layer of Ni / Cr is formed on the end face of the piezoelectric material 5 by a sputtering method, and a gold film is formed on the underlying layer by a sputtering method.

Further, in this embodiment, a bonding pad 10 made of conductive plating is provided on the conductive film forming the electrode 6 of the piezoelectric element 3.

When the bonding pad 10 is formed by the sputtering method, it is necessary to increase the sputtering rate in order to obtain a sufficient film thickness of the bonding pad 10, but if the sputtering rate is increased, the temperature becomes too high. As a result, the piezoelectric material 5 is deteriorated. Further, the sputtered gold film is hard, and the gold ball is not easily bonded. However, by forming the bonding pad 10 by the electrolytic plating method as in this embodiment, it is possible to secure a sufficient film thickness as the bonding pad 10 and to reduce the influence of heat as in the sputtering method. It is not given to the material 5, the bonding state after bonding is strong and good, and the reliability of the piezoelectric element 3 can be improved.

Therefore, a sufficient film thickness can be ensured as the bonding pad 10, so that the wiring (see FIG. 3) from the driving source can be reliably and easily connected to the bonding pad 10.

Next, a case where the electrode 6 of the piezoelectric element 3 is formed of an ITO film and the bonding pad 10 is formed of gold plating will be described with reference to FIG. In FIG. 2,
Although only the electrode 6 on the upper surface is shown, the electrode 6 is similarly formed on the lower surface of the piezoelectric material 5.

It is impossible to form a bonding pad 10 on the electrode 6 made of an ITO film by an ultrasonic bonding method using a gold ball.

Therefore, as shown in FIG. 2A, first, an electrode 6 is formed on the opposing upper end face of the piezoelectric material 5, and a photosensitive resist 11 is formed on the electrode 6 by coating.

Next, as shown in FIG. 2B, the photosensitive resist 11 is exposed and developed, and
1, an opening 11a reaching the electrode 6 is formed. The opening 11a is for forming a bonding pad 10 described later. Further, the opening 11a is formed at the end of the electrode 6 such that the opening 11a is located almost directly above the location A (see FIG. 1) where the piezoelectric element 3 is attached to the suspension 2 with the conductive resin 9 on the surface of the electrode 6. An opening is formed by bringing them together.

Next, as shown in FIG.
1 is used as a mask, and gold is plated in the shape of the bonding pad 10 so that the bonding pad 10 made of gold is
Form on top.

In this case, the bonding pad 10 made of gold plating is connected to the opening 11a of the resist 11 as a mask.
Of the surface of the electrode 6, the piezoelectric element 3 is moved to the end of the electrode 6 such that the piezoelectric element 3 is located almost directly above a place A (see FIG. 1) where the piezoelectric element 3 is attached to the suspension 2 with the conductive resin 9. Formed.

As described above, when the position where the bonding pad 10 made of gold plating is provided is specified, it is possible to prevent the deformation of the piezoelectric material 5 from being hindered. If the bonding pad 10 is formed so as to be closer to the center from the joint A, the stress caused by the deformation of the piezoelectric material 5 is concentrated on the formation of the bonding pad 10 and the electrode 6 is damaged. When the plating process is performed, the film stress is large, and a deformation force is easily applied to the piezoelectric material 5. In order to solve this problem, it is necessary to specify the installation position of the bonding pad 10 as in this embodiment.

As described above, in this embodiment, there is no problem caused by forming the bonding pad 10 made of gold plating on the electrode 6.

When the bonding pad 10 is formed by the sputtering method, it is necessary to increase the sputtering rate in order to obtain a sufficient film thickness of the terminal portion 10. However, if the sputtering rate is increased, the temperature becomes too high. As a result, the piezoelectric material 5 is deteriorated. However, by forming the bonding pad 10 by using the gold plating method as in this embodiment, it is possible to secure a sufficient film thickness as the bonding pad 10 and to reduce the influence of heat on the piezoelectric material as in the sputtering method. 5, the reliability of the piezoelectric element 3 can be improved.

Further, since a sufficient film thickness can be secured for the bonding pad 10, the wiring (FIG. 3) from the driving source can be reliably and easily connected to the bonding pad 10.

When the bonding pad 10 is formed by gold plating, the area of the bonding pad 10 is reduced by Ni.C.
The bonding layer can be restricted to a necessary minimum by the presence of the r underlayer, and the small area of the bonding pad 10 does not hinder the expansion and contraction of the electrode 6 due to the deformation of the piezoelectric material 5.

Further, the thin film thickness of the electrode 6 makes it difficult for burrs to be generated at the end of the piezoelectric element 3 when the piezoelectric element 3 is individually cut out, and damages the surface of the recording disk as a particle. Can be suppressed as much as possible.

Although the bonding pad 10 is formed on the electrode 6 by gold plating, the present invention is not limited to gold plating, and the bonding pad 10 can be formed by plating with solder or the like. Instead of plating, cream solder may be printed with a metal mask to form the bonding pad 10 on the electrode 6. In this case, in the manufacturing process of FIG. 2, a metal mask is used instead of the resist 11, and cream solder is printed with the metal mask to form the bonding pad 10 of the solder on the electrode 6.

FIG. 5 is a plan view showing an embodiment of the present invention. As shown in FIG. 5, the piezoelectric element 3 shown in FIG.
2 are formed in a matrix in the vertical and horizontal directions. Are cut into strips individually surrounded by cutting lines X and Y to form a plurality of piezoelectric elements 3, 3,.... In this case, the bonding pad 1 formed on each piezoelectric element 3
0 is formed near the end on the cutting line X side in the lateral direction. Here, the end on the side of the cutting line X in the lateral direction is located almost directly above the location A where the piezoelectric element 3 is attached to the suspension 2 with the conductive resin 9 on the surface of the electrode 6 shown in FIG. This corresponds to the end of the electrode 6.

As shown in FIG. 5, when the position where the bonding pad 10 made of gold plating is provided is specified, it is possible to prevent the deformation of the piezoelectric material 5 from being hindered. Further, the thickness of the electrode 6 can be reduced, and when the piezoelectric elements 3 are individually cut out from the substrate 12, burrs are less likely to be generated at the ends of the piezoelectric elements 3, thereby damaging the surface of the recording disk as a particle. It is possible to minimize the occurrence of accidents.

[0046]

As described above, according to the present invention, it is possible to easily connect the wiring from the driving source to the bonding pad by securing the necessary film thickness for the bonding pad of the piezoelectric element.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view illustrating a main part of an offset correction mechanism of a magnetic head positioning mechanism according to an embodiment of the present invention, and FIG. 1B is a diagram illustrating a terminal portion formed on an electrode by gold plating. It is a top view explaining the case where it performs.

FIGS. 2A to 2D are cross-sectional views illustrating a method of manufacturing a magnetic head positioning mechanism according to an embodiment of the present invention in the order of steps.

FIG. 3 is a cross-sectional view showing a main part of an offset correction mechanism of a magnetic head positioning mechanism according to a conventional example.

FIG. 4 is a plan view showing an offset correction mechanism of the magnetic head positioning mechanism.

FIG. 5 is a plan view showing an embodiment of the present invention.

FIG. 6 (a) is a perspective view showing a state in which strip-shaped piezoelectric elements are individually cut out from a substrate in a conventional example.
(B) is a perspective view showing an end portion of the piezoelectric element cut into a strip shape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Slider 2 Suspension 3 Piezoelectric element 5 Piezoelectric material 6 Electrode 10 Bonding pad

Claims (11)

[Claims] 1. A magnetic head positioning mechanism having an offset correction mechanism in a suspension of a magnetic head, wherein the offset correction mechanism includes a piezoelectric element, an electrode of the piezoelectric element is formed of a conductive film, and A magnetic pad positioning mechanism provided with a bonding pad. 2. The magnetic head positioning mechanism according to claim 1, wherein said bonding pad is formed so as to be closer to a portion of a surface of said electrode where a piezoelectric element is mounted on a suspension. Magnetic head positioning mechanism. 3. The magnetic head positioning mechanism according to claim 2, wherein said bonding pad is formed to be spaced inward from an edge of said electrode. 4. The magnetic head positioning mechanism according to claim 1, wherein said bonding pad is formed of a gold plating film. 5. The magnetic head positioning mechanism according to claim 1, wherein said bonding pad is formed of a conductive resin. 6. The magnetic head positioning mechanism according to claim 1, wherein the conductive film of the electrode is a transparent conductive film. 7. The magnetic head positioning mechanism according to claim 6, wherein said transparent conductive film is an ITO film. 8. A method for manufacturing a magnetic head positioning mechanism having an offset correction mechanism in a suspension of a magnetic head, comprising: forming an electrode of a piezoelectric element provided in the offset correction mechanism with a conductive film; Forming a bonding pad. 9. The method for manufacturing a magnetic head positioning mechanism according to claim 8, wherein the bonding pad is formed on a surface of the electrode, at a position where a piezoelectric element is attached to a suspension. Manufacturing method of a magnetic head positioning mechanism. 10. The method of manufacturing a magnetic head positioning mechanism according to claim 9, wherein said bonding pad is formed to be spaced inward from an edge of said electrode. 11. The method for manufacturing a magnetic head positioning mechanism according to claim 8, wherein said bonding pad is formed of a gold plating film.