JP2001312806A - Thin film magnetic head, thin film magnetic head slider and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film magnetic head low in cost, wherein corrosion of a magnetic film in an aqueous solution in a polishing and a washing stages can be effectively suppressed and to provide a magnetic head slider and its manufacturing method. SOLUTION: A metal film for communicating a reproducing signal of the thin film magnetic head formed by using a magneto-resistive element for reproducing to an external part is provided with a metal body forming an anode for the magnetic film (metal thin film) of the magneto-resistive element in the aqueous solution in electrically conductive contact and the surface area of the metal body is set larger than the cross sectional area of the magnetic film on a floating surface opposed to a magnetic recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a magnetic recording / reproducing apparatus, and more particularly to a thin film magnetic head made of a thin film magnetic material, a thin film magnetic head slider, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, magnetic recording / reproducing technology has made remarkable progress, and the recording density has been rapidly increasing year by year. In a magnetic disk device, which is a typical magnetic recording / reproducing apparatus, recording on a magnetic recording medium is performed by an electromagnetic induction type element, and reproduction is performed by a magnetoresistive element in order to realize high density and miniaturization. It is common. In recent years, a magnetic recording / reproducing method in which a magnetoresistive element is changed to a giant magnetoresistive element to further improve the efficiency of magnetic reproduction has become mainstream. For these elements, various materials for realizing high density and accompanying miniaturization are used and combined. However, these materials are often very susceptible to corrosion.

Here, the structure of a general thin-film magnetic head will be described. The magnetic head has a cross-sectional structure in which a magnetic film and an insulating film are stacked in multiple layers on a ceramic substrate.
The magnetic film is usually formed as a thin film by a sputtering method. An air bearing surface element portion facing the magnetic recording medium is formed on an element in which such thin films are stacked. The air bearing surface element portion is formed through a polishing process for obtaining a high-precision device height dimension and a cleaning process for removing the processing residue. In the actual manufacturing process of a thin film magnetic head, diamond abrasive grains are suspended during polishing, and water containing a surfactant is used for polishing, and a cleaning solution containing a surfactant in pure water is used for cleaning. Can be Further, pure water is used to rinse the cleaning liquid.

In the polishing and cleaning steps, the metal portion including the magnetic film is exposed to the aqueous solution on the air bearing surface. Corrosion prevention at that time depends on the corrosion resistance of the metal itself. However, corrosion resistance is not always sufficient, and it is unavoidable that the metal is selectively corroded depending on the type of metal. Such corrosion caused irregularities on the air bearing surface, thereby deteriorating the magnetic properties.

As a method for solving this problem by a manufacturing method, a method in which a polishing liquid and a cleaning liquid are converted into a non-polar hydrocarbon solvent has been adopted. Water cleaning is very effective for high cleanliness on the air bearing surface.

In order to suppress the corrosion of a metal thin film which occurs when such an aqueous solution is used, a method of contacting a recording magnetic film portion of a magnetic head with a substance having a higher ionization tendency than that of the magnetic film has been proposed in Japanese Patent Laid-Open No. Hei 1 (1994) -197686. No. 102710 discloses this.

[0007]

However, in the case of a thin film magnetic head using a magnetoresistive element for reproduction, if the above-mentioned substance having a high ionization tendency is brought into contact with the metal thin film, the substance protrudes from the metal thin film. Various noises enter from the above-mentioned substance by acting as an antenna, and a reduction in the signal-to-noise ratio of the reproduced signal cannot be avoided.

In addition, a process for specially producing the substance having a high ionization tendency is required during the thin film manufacturing process, which significantly increases the manufacturing cost. Further, since the above-mentioned substance is formed in the thin-film magnetic head element part which is miniaturized and complicated, the space for disposing the above-mentioned substance is limited, and the substance is required for the above-mentioned substance on the floating surface where the magnetic film whose corrosion is desired to be suppressed is exposed. It is difficult to secure a large area. For this reason, a result that a sufficient corrosion suppressing effect cannot be obtained has been brought.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-cost thin-film magnetic head, a thin-film magnetic head slider, and a method for manufacturing the same, which can effectively suppress corrosion of a magnetic film in an aqueous solution during polishing and cleaning steps during a manufacturing process. It is to provide a method.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to provide a metal film for transmitting a reproduction signal of a thin-film magnetic head using a magnetoresistive element for reproduction to the outside, a magnetoresistive element in an aqueous solution. A metal body forming an anode is provided in conductive contact with the metal film, and the surface area of the metal body is determined from the cross-sectional area of the magnetic film on the air bearing surface facing the magnetic recording medium. Can also be effectively solved by setting a large value. In this case, the portion of the magnetic film exposed on the air bearing surface forms a cathode in the aqueous solution. The metal body is exposed on the outer surface of the thin-film magnetic head so as to be in contact with the aqueous solution.

By adopting such means, it is possible to secure a necessary metal body area by forming a metal body serving as an anode on a metal film having a sufficient area.
Further, since the metal body having the secured area becomes the anode, the outflow of ions from the magnetic film into the aqueous solution is suppressed, that is, the corrosion of the magnetic film is suppressed.

The metal body is desirably a metal having a lower standard electrode potential in an aqueous solution than a metal (magnetic film) which is a magnetoresistive element, since the metal body becomes an anode in the aqueous solution.
More specifically, the metal body includes Al, Zn, Mg, Mn,
It is desirable to be a metal body (for example, a metal simple substance or an alloy) containing a metal selected from the group consisting of Cd, In, Co and Fe.

Here, the mechanism of corrosion inhibition will be described in detail. The mechanism of suppressing the corrosion of the magnetic film by the metal body is based on preferential melting of the metal body. As a result, the thinning of the magnetic film element portion on the air bearing surface is hardly observed. The above-mentioned metal body is called a sacrificial anode, and in the past, the main purpose was to prevent corrosion of large-sized structural materials in seawater. It has been confirmed through examination and experiments that the above metal body is also effective in preventing corrosion of metal materials of the order of nanometers.

Specifically, in the polishing or cleaning step, a metal body having a standard electrode potential lower than that of the magnetic film metal is deprived of electrons by an anodic reaction, that is, an oxidation reaction, at a portion in contact with the aqueous solution, and is thereby ionized. Metals or metal ions are eluted in the aqueous solution. On the other hand, on the side of the magnetic film metal at a higher standard electrode potential, the electrons move to the surface in contact with the aqueous solution via the conductor (the metal film for connection and the metal of the magnetic film) to cause a cathode reaction, that is, a reduction reaction. Since the reduction reaction is to give electrons to the metal ions to precipitate the metal, even if the metal ions of the magnetic film metal are generated, the metal ions are reduced and returned to the magnetic film metal. Corrosion is suppressed. In the anode / cathode reaction, corrosion suppression is effective when the surface emitting the electron, that is, the surface area immersed in the aqueous solution on the metal body side is larger than the cross-sectional area on the air bearing surface on the magnetic film side.

The metal body forming the above-mentioned anode may be a metal substance having a higher ionization tendency than the magnetic film metal in an aqueous solution, and the same effect can be obtained.

A thin film magnetic head slider according to the present invention is a magnetoresistive effect type slider comprising a substrate having a floating surface facing a magnetic recording medium, a magnetic recording element for generating a magnetic field formed on the substrate, and a magnetic film. It is characterized by comprising a magnetic reproducing element, a metal film for electrically connecting the magnetic reproducing element to the outside, and the metal body formed so as to be in conductive contact with the metal film.

Also, the method for manufacturing a thin film magnetic head slider is characterized in that a magnetic recording / reproducing element comprising a magnetic recording element for generating a magnetic field and a magnetoresistive magnetic reproducing element constituted by a magnetic film on an insulating film formed on a substrate. Forming a magnetic recording / reproducing element with an insulating protective film, and exposing a metal film for connecting the magnetic reproducing element to the outside on the outer surface of the insulating protective film. The method is characterized by including a step of forming the metal body that is in conductive contact with the metal film, and a step of polishing and cleaning the air bearing surface facing the magnetic recording medium after the step of forming the metal body.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The thin-film magnetic head, the thin-film magnetic head slider and the method of manufacturing the same according to the present invention will be described in more detail with reference to embodiments shown in several drawings.

In this embodiment, the thin-film magnetic head is constituted as a magnetic recording / reproducing element in which a magnetic reproducing element is combined with a magnetic recording element, and the magnetic recording / reproducing element flies facing the surface of the magnetic recording medium. As a thin-film magnetic head slider.

FIG. 1 shows an embodiment of the present invention configured as a thin film magnetic head slider. In FIG. 1, 101 is a substrate, 100 is a magnetic recording / reproducing element formed by combining a magnetic reproducing element and a magnetic recording element formed on the substrate 101,
Reference numeral 114 denotes an internal metal film serving as a readout lead line for making an electrical connection to the magnetic reproducing element. Reference numeral 115 denotes a read-out portion electrically connected to the internal metal film 114 to make an electrical connection to the outside. The external metal film 200 serving as a relay terminal for
A metal body formed in conductive contact with the external metal film 115;
Reference numeral 16 denotes a recording relay terminal for electrically connecting the magnetic recording element to the outside, and 120 denotes a thin-film magnetic head including the above-described components. Further, in FIG. 1, reference numeral 2 denotes a substrate 101
The air bearing surface rail 3 formed on the surface facing the magnetic recording medium (not shown) of the first embodiment, 3 is the air bearing surface of the floating surface rail 2 facing the magnetic recording medium, 1 is the thin film magnetic head 120,
This is a thin-film magnetic head slider having a flying surface rail 2 and a flying surface 3. The external metal film 115 serving as a relay terminal for reproduction and the relay terminal 116 for recording correspond to the thin-film magnetic head slider 1.
Is formed to be exposed on the side surface.

Next, this embodiment will be described in detail with reference to FIGS. 2 to 5 along with a manufacturing process until the thin film magnetic head slider 1 is completed.

FIG. 2 is a sectional view of the thin-film magnetic head slider 1 after the thin-film element forming step is completed. In the manufacturing process, first, a base insulating film 102 made of alumina or the like is formed on a ceramic substrate 101, then a lower shield film 103, a lower gap film 104 made of alumina or the like is formed, and further,
An element (hereinafter, referred to as “MR element”) 105 composed of a magnetoresistive composite film, which is a magnetic reproducing element, and a pair of electrodes 106 for extracting a magnetic signal of the MR element 105 are formed.

Next, an upper gap film 107 and an upper shield film 108 made of alumina or the like are formed. Further, a magnetic gap film 109 for recording is formed of alumina or the like, and a magnetic pole 110 of a magnetic recording element is formed. Further, a coil 11 for flowing a current for generating a magnetic field in the magnetic pole 110.
1 and an organic insulating layer 112 are formed.

Further, the electrode 10 joined to the MR element 105
Then, an internal metal film 114 serving as a reproduction lead line drawn out from 6 and a recording lead line (not shown) drawn from the coil 111 are formed. Next, a protective film 113 made of alumina or the like for protecting and insulating the above element group is formed.
Finally, an external metal film 115 serving as a relay terminal for reproduction for transmitting a magnetic signal to the outside is exposed to the outside at a position to be a side surface of the thin-film magnetic head slider 1. A recording relay terminal 116 (not shown in FIG. 2) for inputting a current to the coil 112 from outside is formed in the same manner. A plurality of the recording / reproducing elements described above are simultaneously formed on the substrate 101, and the element forming step of the thin-film magnetic head is completed (Step 501 in FIG. 5). In the above steps, the magnetic recording / reproducing element 100 includes the magnetic reproducing element including the MR element 105 and the electrode 106, the upper shield film 108, the magnetic gap film 109, the coil 111, the organic insulating layer 112, and the magnetic pole 11
And a magnetic recording element made of zero.

FIG. 3 is an overall plan view after the above-described thin film magnetic head element forming step is completed. The magnetic recording / reproducing element 100 described above, an external metal film 115 serving as an external metal film reproducing relay terminal for inputting / outputting a signal to / from the outside, and a recording relay terminal 116 are arranged on a single substrate 101 in front and rear. It is formed. Here, the magnetic recording / reproducing element 1
Reference numeral 00 is hidden inside the protective film 113, and an external metal film 115 serving as a recording relay terminal 116 and a reproduction relay terminal is formed on the surface of the protective film 113.

Here, next, the dotted line portion is taken as a cut surface,
The substrate 101 is cut by mechanical grinding to obtain a row bar state 4 (step 502). Thereafter, a metal having a standard electrode potential lower than that of, for example, Cu, which is a part of the constituent material of the MR element 105, in an aqueous solution used for polishing and cleaning of the air bearing surface, which is a later step, such as Al, Zn, Mg, Mn, or the like. Cd, In, C
A small piece of either o or Fe metal or an alloy using them is bonded to the external metal film 1 by ultrasonic bonding.
15 are brought into conductive contact and fixed to form a metal body 200 (step 503). In forming the metal body 200, a plating method, a sputtering method, or the like can be adopted instead of the ultrasonic bonding method. The area of the metal body 200 is set to be larger than the cross-sectional area on the air bearing surface of the MR element 105 described later, that is, the cross-sectional area on the air bearing surface of the magnetic film.

After the completion of the forming step, the floating surface 3 is formed by polishing using the dashed line in FIG. 2 as a cut surface (Step 5).
04). FIG. 4 shows the obtained flying surface 3. The respective cross sections of the MR element 105, the electrode 106, the lower shield film 103, the upper shield film 108, and the magnetic pole 110 of the magnetic recording element are formed on the air bearing surface 3 by polishing.

Subsequently, cleaning is performed (step 505) to improve the sliding resistance of the floating surface 3 shown in FIG. 1 with the magnetic recording medium, to improve the subsequent manufacturing process, and to improve the floating surface after the magnetic head is completed. An air-bearing surface protection film 4 made of inorganic carbon is formed to prevent corrosion of the thin film element portion (step 506). Next, after forming the flying surface rail 2 for stabilizing minute flying from the magnetic recording medium (step 507), the plurality of recording / reproducing elements 100 are cut one by one by mechanical grinding (step 508). ) And further washing (step 509) to complete the thin-film magnetic head slider 1.

Thereafter, the completed thin-film magnetic head slider 1 is bonded and fixed to a spring arm (not shown), wiring is assembled (step 510), and washing is performed (step 511). The apparatus is assembled (step 512).

In the above description, the metal body 200 is formed after the row bar cutting (step 502). However, depending on the forming means, the thin film element is formed (step 501).
There is no problem if it is formed after. 1 and 3
Although the metal body 200 is formed on both of the external metal films 115 serving as a pair of relay terminals for reproduction, the effect is exerted even when formed on only one external metal film 115. Furthermore,
In FIGS. 1 and 3, the metal body 200 includes the external metal film 11.
5 is formed outside the external metal film 115, and there is no problem even if its end reaches the edge of the thin film magnetic head slider 1.

Further, the external metal film 115 is
The wiring metal film may be made of an externally exposed wiring metal film electrically connected to the wiring 14 and a metal film serving as a reproduction relay terminal, and the metal body 200 may be brought into conductive contact with the wiring metal film. Alternatively, the external metal film 115 may be only the externally exposed wiring metal film electrically connected to the internal metal film 114, and the reproduction relay terminal connected to the wiring metal film may be formed of the metal body 200. Similar effects can be obtained.

Here, the effect of the case where the metal body 200 was installed on the thin-film magnetic head as described above was examined by experiments. The experiment was performed in the cleaning step (505) after the air bearing surface polishing (step 504), and the resistance was measured by measuring the resistance of the MR element 105 with and without the metal body 200 formed. In the cleaning step (505), a cleaning aqueous solution containing a surfactant in pure water was used. The metal body 200 is formed by forming Al on the external metal film 115 serving as a relay terminal for reproduction by an ultrasonic bonding method,
The surface area of the metal body 200 was set to 5,000 to 10,000 times the cross-sectional area of the flying surface side MR element 105.

Specifically, the magnetic head was immersed for 10 minutes while the cleaning aqueous solution was heated to 40 ° C., and the resistance value of the MR element 105 before and after immersion was measured. 6A and 6B show the measurement results when the metal body 200 is formed and when it is not formed, respectively. The horizontal axis of FIG. 6 is the resistance value of the MR element 105 before immersion in the aqueous solution, and the vertical axis is the resistance value of the MR element 105 after immersion in the aqueous solution.

As a result, in the thin film magnetic head of the present invention in which the metal body 200 is formed, the MR element 105
It was found that the resistance value of the sample hardly changed. That is, it is shown that the corrosion of the MR element 105 was able to be suppressed because the metal body 200 corroded preferentially.
On the other hand, in the thin-film magnetic head in which the metal body 200 was not formed, it was found that the resistance of the MR element 105 was greatly increased after immersion. That is, the air bearing surface side MR element 10
5 shows that the height dimension of the MR element 105 was reduced due to metal elution from the surface of No. 5 and a depression.
As a result, it can be seen that the MR element 105 is corroded.
From the above experiments, it was possible to demonstrate that the present invention can provide an effect of preventing corrosion.

As described above, by forming the metal body 200 having a surface area larger than the cross-sectional area on the floating surface side of the MR element 105 on the external metal film 115 serving as a relay terminal for reproduction before the polishing of the floating surface, When the polishing liquid at the time of polishing and the subsequent cleaning liquid are aqueous solutions containing a surfactant, MR
Corrosion of the element 105 in the aqueous solution could be prevented. After the formation of the air bearing surface protection film 4, the protection film prevents corrosion in the subsequent steps. However, although rare, what can happen during the manufacturing process is a scratch due to contact with the air bearing surface 3 or a partial exposure of the MR element 105 due to peeling of the protective film. The thickness of the air bearing surface protection film 4 is:
It tends to become thinner as the magnetic recording density increases,
Under certain conditions, a pinhole is likely to occur in the film itself, which may cause partial exposure of the MR element 105. Even in such a case, according to the present invention, it is possible to prevent corrosion at an exposed portion of the MR element 105 which is immersed in the aqueous solution in a subsequent step such as cleaning.

An external metal film 1 serving as a relay terminal for reproduction
By providing the metal body 200 on the surface 15, the surface area can be increased, and the effect as a sacrificial anode can be sufficiently exhibited. Furthermore, since the metal body 200 can be formed after the completion of the thin-film element formation step, the manufacturing equipment can be inexpensive.

[0037]

According to the present invention, corrosion of the MR element of the thin-film magnetic head can be prevented not only during the manufacturing process but also after the manufacturing. In addition, since thinning due to corrosion can be prevented, efficient recording / reproduction without flying loss at the time of recording / reproduction becomes possible. In addition, it is possible to prevent the progress of corrosion over time from corrosion marks, and to provide a thin-film magnetic head with high manufacturing yield, high reliability, high density, small size, and low cost. .

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining an embodiment of a thin film magnetic head slider on which a thin film magnetic head according to the present invention is mounted.

FIG. 2 is a cross-sectional view for explaining an embodiment of the thin-film magnetic head according to the present invention.

FIG. 3 is a plan view for explaining a step of forming a thin-film magnetic head element according to the present invention.

FIG. 4 is an enlarged perspective view illustrating a flying surface element portion of the thin-film magnetic head.

FIG. 5 is a flowchart for explaining a manufacturing process of the thin-film magnetic head of the present invention.

FIG. 6 is a curve diagram for explaining a corrosion test result of the thin film magnetic head of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Thin film magnetic head slider 2 ... Floating surface rail 3 ...
Air bearing surface, 4 ... Floating surface protection film, 100 ... Magnetic recording / reproducing element, 101 ... Ceramic substrate, 102 ... Base insulating film, 1
03: lower shield film, 104: lower gap film, 10
5 MR element, 106 electrode, 107 upper gap film, 108 upper shield film, 109 magnetic gap film, 110 magnetic pole, 111 coil, 112 organic insulating layer, 113 protective film, 114 internal metal Reference numeral 115 denotes an external metal film, 116 denotes a recording relay terminal, 120 denotes a thin-film magnetic head, and 200 denotes a metal body.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kenya Ohashi 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi Ltd. 5D034 BA02 BA09 BB05 BB12 DA07 5D042 PA05 PA09 RA02

Claims (6)

[Claims] 1. A magneto-resistance effect type magnetic reproducing element constituted by a magnetic film, a metal film for electrically connecting the magnetic reproducing element to the outside, and a metal formed so as to be in conductive contact with the metal film. The metal body is a metal body that forms an anode with respect to the metal of the magnetic film in an aqueous solution, and has a surface area of the magnetic film on the air bearing surface facing the magnetic recording medium. A thin-film magnetic head having a larger cross-sectional area. 2. The thin-film magnetic head according to claim 1, wherein the metal body has a standard electrode potential in an aqueous solution lower than that of the metal of the magnetic film. 3. The metal body is made of Al, Zn, Mg, Mn, C
3. The thin-film magnetic head according to claim 1, comprising a metal selected from the group consisting of d, In, Co, and Fe. 4. A substrate having a floating surface facing a magnetic recording medium; a magnetic recording element for generating a magnetic field formed on the substrate; A metal film for electrically connecting the reproducing element to the outside, and a metal body formed so as to be in conductive contact with the metal film, and the metal body is formed of a metal of the magnetic film in an aqueous solution. A thin-film magnetic head slider, which is a metal body forming an anode and has a surface area larger than a cross-sectional area of a magnetic film on an air bearing surface facing a magnetic recording medium. 5. A step of forming, on an insulating film formed on a substrate, a magnetic recording / reproducing element comprising a magnetic recording element for generating a magnetic field and a magneto-resistance effect type magnetic reproducing element constituted by a magnetic film; A step of covering the read element with an insulating protective film, a step of forming a metal film for connecting the magnetic read element to the outside so as to be exposed on the outer surface of the insulating protective film, and a step of forming a metal body in conductive contact with the metal film. Forming, and after the step of forming the metal body, a step of polishing and cleaning the air bearing surface facing the magnetic recording medium, wherein the metal body has the magnetoresistance effect in an aqueous solution. A method of manufacturing a thin-film magnetic head slider, comprising: a metal body forming an anode with respect to a metal of the film; and a surface area of the metal body is larger than a cross-sectional area of the magnetoresistive film on the air bearing surface. 6. The method according to claim 5, wherein the step of forming the metal body is performed by an ultrasonic bonding method.