JP2002197606A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a stable characteristic compatible with a high sensitivity and high density by maintaining a good contact state with a magnetic tape for a long time in a magnetic head using the magnetic tape as a recording medium. SOLUTION: The magnetic head is provided with a roughly circular-arc sliding surface 10 to be slid with a magnetic tape TP, and is constituted of the sliding surface 10 being formed in a thin-film laminate structure where a pair of hard nonmagnetic substrates 13 and 14 are laminated in the traveling direction of the magnetic tape TP in the form of sandwiching the head element 11 of a magneto-resistance effect type with a soft magnetic body 12 in between. In this case, a distance between the hard nonmagnetic substrate 13 of a magnetic tape entering side and the head element 11 is set smaller than that between the hard nonmagnetic substrate 14 of a magnetic tape ejecting side and the head element 11.

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 for a magnetic tape as one of recording media, and more particularly to a magnetic head having a magnetoresistive head element (hereinafter referred to as "MR element"). The configured magnetic head (hereinafter "M
R head).

[0002]

2. Description of the Related Art In recent years, for example, video tape recorders (V
In a system using a magnetic tape as a recording medium such as TR), an MR head is sometimes used as a reproducing head. This is because MR elements are generally more suitable for high-density recording than inductive magnetic head elements that perform recording and reproduction using electromagnetic induction.
This is because higher density recording can be achieved by using a head.

When used in such a system, for example, as shown in FIG. 21, the MR heads RH1 and RH2 are mounted on a rotating drum 2a and reproduce signals from a magnetic tape TP by a helical scan method. At this time, the MR heads RH1 and RH2 slide at high speed with the magnetic tape TP.

[0004] From this, the MR head is, for example, shown in FIG.
As shown in FIG. 2, a substantially arc-shaped sliding surface 52 having an MR element 51 disposed at a substantially apex is formed, and the sliding surface 52 contacts the magnetic tape TP. On the sliding surface 52, for example, if it is a shield type, the MR element 5
The soft magnetic thin films 53 are disposed so as to sandwich the pair 1 and the pair of hard non-magnetic substrates 54 further sandwich them. That is, the sliding surface 52 has a thin film laminated structure in which the MR element 51 is sandwiched between the pair of hard non-magnetic substrates 54 with the soft magnetic thin film 53 interposed therebetween along the running direction of the magnetic tape TP.

[0005]

When an MR head is used for a magnetic tape, its recording / reproducing characteristics are greatly affected by the state of contact between the two. That is, if the contact state between them is poor, the distance between the MR head and the magnetic tape (hereinafter referred to as "spacing") increases, so-called spacing loss occurs. The output greatly decreases.

The contact state between the MR head and the magnetic tape is as follows.
It changes greatly depending on the curvature of the sliding surface, the recess amount of the MR element, and the like. In other words, if the running state of the magnetic tape is constant, it greatly depends on the shape of the sliding surface and the position of the MR element, and distribution may occur on the same sliding surface, or the position of the MR element may be changed. May cause a change in the amount of spacing. Specifically, for example, as shown in FIG. 23, on the entry side of the magnetic tape, a gap between the magnetic tape and the sliding surface is widened due to air encapsulation accompanying the running of the magnetic tape. It is conceivable that the amount increases.

[0007] In addition, between the MR head and the magnetic tape, especially when both slide at high speed,
The contact state between the two may change due to the wear of the sliding surface caused by the sliding. For example, the discharge side of the magnetic tape has a higher tension with the magnetic tape than the entry side, and the rate of uneven wear during long-time running is large. Moreover, the portion of the soft magnetic thin film that supports the MR element is softer than the hard non-magnetic substrate that supports the MR element. Therefore, after the magnetic tape runs for a long time, as shown in, for example, FIG. 24, uneven wear occurs such that the portion of the soft magnetic thin film on the discharge side of the magnetic tape is deeply digged. Output may also decrease.

[0008] The present invention has been proposed in view of the above-described conventional situation. Even when the present invention is used in a system using a magnetic tape as a recording medium, it has high sensitivity and high density. An object of the present invention is to provide a magnetic head suitable for realizing stable characteristics.

[0009]

SUMMARY OF THE INVENTION The present invention is a magnetic head devised to achieve the above object. That is, the magnetic head according to the present invention is mounted on a rotating head of a system using a magnetic tape as a recording medium, and has a magnetoresistive head element for reproduction (that is, an MR element). A substantially arc-shaped sliding surface that slides on the tape is provided, and the sliding surface is formed in a running direction of the magnetic tape such that the pair of hard non-magnetic substrates sandwich the MR element via a soft magnetic material. The distance between the hard non-magnetic substrate on the entry side of the magnetic tape and the MR element is such that the hard non-magnetic substrate and the MR on the ejection side of the magnetic tape are arranged.
It is characterized by being formed smaller than the distance from the element.

According to the magnetic head having the above-described structure, even if unevenness such that the portion of the soft magnetic material including the MR element on the discharge side of the magnetic tape is deeply dug down occurs after the magnetic tape has run for a long time, Since the position of the MR element in this portion is closer to the entry side of the magnetic tape, the degree of digging at the position of the MR element can be suppressed, and an increase in the amount of spacing can be suppressed. Further, the suppression is performed by using the MR between a pair of hard non-magnetic substrates.
Since it is realized by the position of the element, it is possible to appropriately set the shape of the sliding surface and the position of the MR element on the sliding surface, thereby causing uneven wear and a change in the spacing amount. It becomes possible to cope with suppression.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic head according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional configuration diagram showing an example of a thin film laminated structure in a magnetic head according to the present invention, and FIG. 2 is a schematic diagram showing a schematic configuration of a system using the magnetic head.

First, prior to the description of a magnetic head according to the present invention, a system using the magnetic head will be described. Here, information recording and
A magnetic tape device as a reproducing device will be described as an example.
As shown in FIG. 2, the magnetic tape device 1 is configured by combining a magnetic head device 2 and a magnetic tape TP.

The magnetic head device 2 includes a rotating drum 2a, a fixed drum coaxial with the rotating drum 2a, a motor (not shown), and the like. Rotary drum 2a
Is designed to rotate by the operation of a motor.
Two reproducing heads RH1 and RH2 and two recording heads WH1 and WH2 are mounted. Each reproducing head RH1,
RH2 and the recording heads WH1 and WH2 have a phase difference of 180 °. Each of the reproducing heads RH1,
RH2 corresponds to the magnetic head according to the present invention. Note that each of the recording heads WH1 and WH2 may be constituted by, for example, an inductive magnetic head.

On the other hand, the magnetic tape TP is obliquely adhered to both the rotating drum 2a and the fixed drum from the supply reel 3 via the rollers 4a, 4b and 4c for approximately 180 °, and the rollers 4d, 4e, 4f and 4g are brought into contact with each other. After that, it is taken up by the take-up reel 5. Thereby, the recording heads WH1,
WH2 and reproduction heads RH1 and RH2 are magnetic tape TP
Is guided in contact with the helical scan method. In addition, the capstan 6 corresponds to the roller 4f.
The capstan 6 keeps the running speed of the magnetic tape TP substantially constant.

That is, the magnetic head according to the present invention is used, for example, in the magnetic tape device 1 using the above-described magnetic tape TP as a recording medium. More specifically, it is mounted on a rotating drum 2a of the magnetic tape device 1 and slides at high speed with the magnetic tape TP by a helical scan method to reproduce a signal from the magnetic tape TP.

To perform such signal reproduction, the magnetic head according to the present invention utilizes the magnetoresistance effect of the MR element. That is, the magnetic head according to the present invention has M
This is an MR head having an R element.

Here, the configuration of the magnetic head according to the present invention, that is, the MR head will be described in detail. As shown in FIG. 1, the MR head described here also uses a magnetic tape T
Since it slides at a high speed with P, almost the same as the conventional one,
A substantially arc-shaped sliding surface 10 that slides on the magnetic tape TP is provided.

On the sliding surface 10, a soft magnetic thin film 12 is provided so as to support the MR element 11 for magnetic shielding, and a pair of hard non-magnetic substrates 13 and 14 are formed on the soft magnetic thin film 12. It is pinched. That is, the sliding surface 10 is
The R element 11 has a thin film laminated structure in which a pair of hard non-magnetic substrates 13 and 14 are sandwiched between soft magnetic thin films 12 so as to be stacked along the running direction of the magnetic tape TP.

In the illustrated example, the portion near the MR element 11 is shown in a large size for easy understanding of the characteristics. However, in practice, this portion is much finer than the hard non-magnetic substrates 13 and 14. It is. Specifically, for example, the length t1 of the hard non-magnetic substrate 13 in the magnetic tape running direction on the entry side of the magnetic tape TP is about 0.8 mm.
The length t2 of the portion including the R element 11 and the soft magnetic thin film 12 in the running direction of the magnetic tape is about 5 μm. Therefore, in this MR head, the sliding surface 10 is
Almost only the upper end faces of the hard non-magnetic substrates 13 and 14.

By the way, the MR head according to the present embodiment is an MR element 11 that senses a magnetic flux from a magnetic tape TP.
Has the following characteristics.

As one of them, in the MR head of the present embodiment, the distance A between the hard non-magnetic substrate 13 and the MR element 11 on the entry side of the magnetic tape TP is determined by the magnetic tape TP.
Is formed smaller than the distance B between the hard non-magnetic substrate 14 and the MR element 11 on the discharge side of. That is, the MR between the pair of hard non-magnetic substrates 13 and 14
The position of the element 11 is closer to the entry side of the magnetic tape TP than the intermediate point between the hard non-magnetic substrates 13 and 14.

For this reason, even when the magnetic tape TP slides over the magnetic tape TP for a long time at high speed, uneven wear such as a deep digging of the discharge side of the magnetic tape TP tends to occur. The degree of digging at the position of the MR element 11 is suppressed as compared with the case where the MR element 11 is located at an intermediate point between the substrates 13 and 14 or the discharge side of the magnetic tape TP. In other words, even if the portion including the MR element 11 and the soft magnetic thin film 12 is softer than the hard non-magnetic substrates 13 and 14 sandwiching them, and the degree of uneven wear due to high-speed sliding for a long time is high, An increase in the amount of spacing between the MR element 11 and the magnetic tape TP can be minimized.

It is conceivable that the position of the MR element 11 is moved toward the magnetic tape entry side as follows. For example, the MR element 11 is simply
This is realized by moving only the position (1) to the magnetic tape entry side. Further, for example, by increasing the lamination thickness of the hard nonmagnetic substrate x on the magnetic tape entry side as compared with the related art, the position of the MR element 11 is relatively moved toward the magnetic tape entry side. Further, the portion of the soft magnetic thin film 12 (except for the MR element 11) on the sliding surface 10 is moved toward the magnetic tape discharge side, so that the MR element 11 is relatively moved.
May be shifted to the magnetic tape entry side.
In addition, it may be realized by simply increasing the lamination thickness of the soft magnetic thin film 12 on the magnetic tape discharge side.

In order to move the position of the MR element 11 toward the entry side of the magnetic tape as described above, various realization methods are conceivable. However, in the MR head of the present embodiment, the portion of the soft magnetic thin film 12 (however, This is realized by moving (except for 11) to the magnetic tape discharge side as a whole. In other words, in the MR head of the present embodiment, the fact that the intermediate point between the pair of hard non-magnetic substrates 13 and 14 is located closer to the magnetic tape discharge side than the substantially arc-shaped apex of the sliding surface 10. It has one other feature.

This is because the uneven wear on the sliding surface 10 caused by the high-speed sliding with the magnetic tape TP for a long time is as follows.
This is because the configuration and the position of the hard non-magnetic substrates 13 and 14 on the sliding surface 10 vary greatly. Here, the relationship between the configuration of the sliding surface and its wear state will be described with reference to some specific examples. FIG. 3 is an explanatory diagram showing a specific example of the relationship between the configuration of the sliding surface and the state of wear thereof.

For example, in the case where the intermediate point of the hard non-magnetic substrate supporting the MR element is shifted from the top of the arc of the sliding surface toward the magnetic tape entry side, the deviation after the magnetic tape has been running for about 200 hours. The state of wear is shown in FIG. In this specific example, the portion of the magnetic tape that makes the strongest contact on the sliding surface is shifted from the apex of the arc toward the magnetic tape entry side, so that the portion of the MR element and the soft magnetic thin film that is softer than the hard non-magnetic substrate Wears quickly, resulting in extreme spacing loss and reduced reproduction output.

On the other hand, in the case where the intermediate point of the hard non-magnetic substrate coincides with the apex of the arc and the case where the intermediate point of the substrate is shifted to the magnetic tape discharge side, the uneven wear after running for about 200 hours is shown in FIG. Represented in b) and (c). In these specific examples, since the hard non-magnetic substrate is disposed at a portion that comes into strong contact with the magnetic tape, the above-described FIG.
Compared with the example of (a), there is less uneven wear even after running for a long time, and the spacing with the magnetic tape can be kept small.

From these facts, in order to suppress the occurrence of uneven wear, it is necessary to dispose a hard non-magnetic substrate at a portion which is in strong contact with the magnetic tape and to limit the distance between the hard non-magnetic substrates so as not to increase. Is effective.
Therefore, the MR head of the present embodiment has the MR element 11
Is shifted toward the magnetic tape entry side, the portion of the soft magnetic thin film 12 (except for the MR element 11) is entirely shifted to the magnetic tape ejection side, and the hard non-magnetic substrate 1
The intermediate point between 3 and 14 is located closer to the magnetic tape discharge side than the substantially arc-shaped apex of the sliding surface 10 so as to minimize the occurrence of uneven wear.

As another feature, in the MR head according to the present embodiment, as shown in FIG. 1, the MR element 11 is disposed near the substantially arc-shaped apex of the sliding surface 10. This is because the best spacing characteristics are obtained near the apex on the substantially arc-shaped sliding surface 10. That is, in the vicinity of the substantially arc-shaped apex, for example, as in the portion on the magnetic tape entry side, there is no possibility that the space is increased due to the air encapsulation accompanying the running of the magnetic tape and the spacing amount is increased. Further, unlike the portion on the magnetic tape discharge side, for example, the magnetic tape TP is not greatly affected by uneven wear after running for a long time.

That is, if the MR element 11 is disposed near the substantially arc-shaped apex of the sliding surface 10, good spacing characteristics can be obtained over a long period of time from the initial running of the magnetic tape TP to after the running thereof for a long time. Will be.

With the above-described configuration, the MR head of the present embodiment is capable of maintaining the MR head even when the sliding surface 10 is unevenly worn due to high-speed sliding with the magnetic tape TP for a long time.
The amount of spacing between the R element 11 and the magnetic tape TP is suppressed from becoming large, and the uneven wear itself is hardly generated as much as possible. Pacing characteristics can be obtained. Therefore, the use of the MR head of the present embodiment makes it possible to maintain high output over a long period of time and good frequency characteristics, which is suitable for realizing stable characteristics with high sensitivity and high density.

Next, a method for manufacturing the above MR head will be described. 4 to 19 are views for explaining the procedure for manufacturing the MR head. In addition, in these figures, in order to clearly show the features, similarly to FIGS. 1 to 3, the characteristic portions may be shown in an enlarged manner, and the dimensional ratio of each member is the same as the actual one. Not necessarily. In the following description, specific examples of members constituting the MR head, their materials, sizes, thicknesses, and the like will be described, but the present invention is not limited to the following examples. For example, in the following description, a so-called shield-type SAL (Soft Adjacent Layer) bias type M having a structure similar to that practically used in a hard disk device or the like is used.
Although an example using an R element is given, an MR element such as a GMR (Giant MR) head or a spin valve head can of course be used.

When manufacturing the MR head described in this embodiment, first, as shown in FIGS. 4A and 4B, a disk-shaped substrate 131 having a diameter of, for example, 4 inches is prepared. The surface of 131 is mirror-finished. The substrate 131 is a hard non-magnetic substrate 1 on the magnetic tape entry side.
Specifically, Al ₂ O ₃ —TiC (altic), α-Fe ₂ O ₃ (α-hematite), NiZn ferrite, and the like are preferable.

Then, on the substrate 131, the substrate 13
In order to improve the surface property of No. 1, a substrate surface improving film 132 is formed. This is to improve the magnetic properties of the soft magnetic film, which is the lower shield formed next, by improving the surface properties of the substrate 131. Substrate surface improvement film 132
Is formed by spattering Al ₂ O ₃ by about 2 μm and then performing chemical polishing such as buffing to obtain a smooth surface state, so that the thickness remaining after polishing becomes about 1 μm. Conceivable. However, the thickness of the substrate surface improving film 132 is the same as that of the hard non-magnetic substrate 13 described above.
Since it affects the distance A to the R element 11, it is necessary to accurately grasp the distance A.

After the formation of the substrate surface improving film 132, a soft magnetic thin film 121 is formed on the substrate surface improving film 132 by a sputtering method in order to form a lower layer film shield described later. The soft magnetic thin film 121 used here is not particularly limited as long as it shows good soft magnetism and is excellent in abrasion corrosion, such as FeAlSi (Sendust). However, in order to function as a shield for the MR head, a thickness of at least twice the longest wavelength used in the system is required, and the thickness of the entire laminated film is determined as necessary (for example, 2.5 μm). .

After the soft magnetic thin film 121 is formed, thereafter, patterning for separating the lower film shield for each head is performed. First, a resist pattern 122 having a size of, for example, about 80 μm in width and about 100 μm in height is formed at a position where an MR element is formed by using a so-called photolithography technique of performing exposure and development to a required shape after applying a resist film. leave. Then, the soft magnetic thin film 121 where the resist pattern 122 is not formed is removed by ion etching, and then the resist pattern 122 is removed with an organic solvent.

As a result, the resist pattern 122 is formed on the substrate surface improving film 132 as shown in FIG.
Is formed. After the lower film shield 123 is formed, subsequently, in order to eliminate the unevenness of the portion remaining as the lower film shield 123 and flatten the substrate surface, Al ₂ O is formed on the entire surface of the substrate by a forming method such as sputtering or vapor deposition. ₃ is formed, for example, to about 5 μm, and the surface is polished until the upper surface of the lower film shield 123 appears. At this time, the amount of Al ₂ O ₃ formed should be equal to or greater than the thickness of the lower film shield 123 because the lower film shield 123 needs to be completely buried. Note that SiO ₂ or the like may be used instead of Al ₂ O ₃ . Polishing of the surface
After rough grinding with diamond abrasive grains, the surface may be conditioned by chemical polishing (buff polishing), or only chemical polishing may be performed from the beginning. However, it is necessary to perform the process until the surface of the lower film shield 123 is exposed over the entire surface of the substrate. Then, the soft magnetic thin film 121 used for the lower film shield 123 is formed.
The material is subjected to an optimal heat treatment according to the type of the material. For example, if the soft magnetic thin film 121 is Sendust, 550 ° C.
After heating for about 1 hour, keep at the same temperature for 1 hour,
Thereafter, a heat treatment such as natural cooling is applied.

After such a heat treatment, the non-magnetic non-conductive film 111 serving as a lower layer gap of the MR element 11 is
The film is formed by sputtering or the like. Here, the material of the nonmagnetic nonconductive film 111, from the viewpoint of insulating properties and abrasion resistance, Al ₂ O ₃ are preferred. The thickness of the non-magnetic non-conductive film 111 may be set to an appropriate value according to the frequency of a recording signal and the like, and may be set to, for example, about 100 nm. However, at this time, in the method of calculating the film thickness of the lower layer gap, G is defined as G / 2− (the lower layer Ta5 nm + the SAL bias layer N).
iFeNb 32 nm + intermediate insulating layer Ta 5 nm + MR layer N
If it is determined that iFe is 30 nm / 2), the MR element will be installed in the middle of the lower shield and the upper shield.

After the non-magnetic non-conductive film 111 is formed,
As shown in FIGS. 5A and 5B, the SAL bias type MR element 1 is formed on the nonmagnetic nonconductive film 111.
A thin film 112 (hereinafter, referred to as “MR element thin film”) 112 for forming 1 is formed. Specifically, the MR element thin film 1
12 is, for example, Ta (5 nm) / NiFeNb (24
nm) / Ta (5 nm) / NiFe (20 nm) / Ta
(1 nm) in this order by sputtering. In this case, NiFe is a soft magnetic film having a magnetoresistive effect, and becomes a magnetically sensitive part of the MR element 11. NiFeNb becomes a soft magnetic film (so-called SAL film) for applying a bias magnetic field to NiFe. The material and the film thickness of the magnetoresistive element are not limited to the above examples, but may be appropriately selected according to the requirements of the system.

Thereafter, in order to stabilize the operation of the MR element, as shown in FIGS. 6 and 7A and 7B, two rectangular permanent magnet films 113 are provided for each MR element.
a and 113b are converted to M by photolithography technology.
It is embedded in the R element thin film 112. Further, in order to reduce the resistance value of the element, the permanent magnet films 113a, 113b
A conductive material (hereinafter referred to as a “resistance reducing film”) 114 a and 114 b having a lower resistance value is formed on the upper surface of the substrate. In addition,
FIG. 7 (including FIGS. 8 to 12 to be described later) shows an enlarged portion corresponding to one MR element 11, that is, a portion indicated by an arrow C in FIG.

Each of the permanent magnet films 113a and 113b has, for example, a length t3 in the long axis direction of about 50 μm and a length t3 in the short axis direction.
4 is about 10 μm, and the interval t5 is about 5 μm. This interval t5 finally becomes the track width (for example, about 5 μm) of the MR element 11. However, the track width is not limited to the above example, and may be set to an appropriate value according to the requirements of the system. The positions where the permanent magnet films 113a and 113b are installed are as follows.
It is necessary to be on the lower layer film shield 123 and be contained in the lower layer shield. However, it is sufficient that a portion finally remaining as the shield is about 5 times or more the width (depth) of the MR element in the magnetic flux entry direction.

When embedding the permanent magnet films 113a and 113b and the low-resistance films 114a and 114b, for example, first, a mask having two rectangular openings for each MR element is formed using photoresist. Then, etching is performed to remove the MR element thin film 112 exposed in the opening. Note that the etching here may be either a dry method or a wet method, but ion etching is preferable in consideration of ease of processing and the like. Next, a permanent magnet film 113 is formed by sputtering or the like. The material of the permanent magnet film 113 has a coercive force of 1000 [O
e] Above materials such as CoNiPt and CoCrPt
Etc. are preferred. The thickness is made equal to the thickness of the MR element 11.

After the permanent magnet film 113 is formed, a resistance reducing film 114 is further formed by sputtering or the like. The material of the low resistance film 114 is, for example, Cr, T
a and the like are preferable. And the thickness is, for example, 60n
m. These thicknesses, including the permanent magnet film 113,
It is determined by the resistance value required for the system, the track width of the MR element, and the like. Thereafter, the photoresist serving as a mask is replaced with the permanent magnet film 11 formed on the photoresist.
3 and the resistive film 114 are removed. As a result, the permanent magnet films 113a and 113b and the resistance reducing films 114a and 114b having the predetermined patterns are embedded in the magnetoresistive effect element thin film 12.

Thereafter, as shown in FIGS. 8A and 8B, finally, the M
Part that operates as an R element (hereinafter referred to as “element part”)
The MR element thin film 112 is removed while leaving 115. At this time, a portion serving as a terminal for supplying a sense current to the element portion 115 (hereinafter, referred to as a “terminal portion”)
115a and 115b are also left. Specifically, for example, first, a mask having openings in the element portion 115 and the terminal portions 115a and 115b is formed for each MR element using photoresist. Next, etching is performed to remove the MR element thin film 112 exposed in the opening.
Note that the etching here may be either a dry method or a wet method, but ion etching is preferable in consideration of ease of processing and the like. Thereafter, by removing the photoresist used as a mask, the element portion 115 and the terminal portion 115 of the MR element thin film 112 are removed.
a and 115b are left.

The width t6 of the element portion 115 is, for example, about 3 μm. This width t6 finally corresponds to the length from the end to the other end of the element portion 115 on the tape sliding surface side, that is, the depth length d. Therefore, in this example,
The depth length d of the element portion 115 is about 3 μm. However, the depth length d is not limited to the above example, but may be set to an appropriate value according to the requirements of the system. For the terminal portions 115a and 115b, for example, each length t7 is set to about 1.5 mm,
Each width t8 is about 80 μm, and their interval t9
To about 40 μm.

Next, by using photolithography technology, the terminal portions 115a and 115b for supplying a sense current to the element portion 115 are replaced with conductive films having lower electric resistance, and a sense current is supplied to the element portion 115. Terminals 115a 'and 115b' are formed. Specifically, first, a mask having openings in portions 115a and 115b to be terminals is formed using photoresist. Then, etching is performed to remove the MR element thin film 112 remaining in portions exposed in the openings, that is, portions 115a and 115b to be terminals. Next, with the photoresist mask left as it is,
A conductive film is formed thereon. Here, the conductive film is, for example, Ti (10 nm) / Cu (90 nm) / Ti (10
nm) in this order by sputtering. After that, the photoresist serving as a mask is removed together with the conductive film formed on the photoresist. Thus, a terminal formed of the conductive film is formed.

Then, as shown in FIGS. 9A and 9B, after forming the terminals 115a 'and 115b',
Non-magnetic non-conductive film 116 serving as upper gap of element 11
Is formed by sputtering or the like. Here, Al ₂ O ₃ is preferable as the material of the non-magnetic non-conductive film 116 from the viewpoint of insulation properties, abrasion resistance, and the like. The thickness of the non-magnetic non-conductive film 116 may be set to an appropriate value according to the frequency of the recording signal and the like, and specifically, is set to, for example, 120 nm. The method for accurately calculating the film thickness of the upper layer gap is as follows: G = 2- (MR layer Ni)
By deciding (Fe 30 nm / 2 + lower layer Ta 5 nm), the MR element is installed at the middle of the lower layer shield and the upper layer shield.

After the formation of the nonmagnetic nonconductive film 116, a soft magnetic thin film 124 serving as an upper shield is formed. At this time, the soft magnetic thin film 124 has an upper gap of Al ₂ O ₃
Then, as shown in FIG. 10 or FIG. 11, a portion required as an upper shield is formed as an opening 125a by masking with resist films 125b and 125c. Thereby, the shape of the soft magnetic thin film 124 is set to a required shield shape.

However, what is important here is that the opening 12
5a, the end faces of the resist films 125b and 125c
As shown in FIG.
1B has a two-layer structure, and the upper layer side has a shape protruding from the lower side. The reason for forming such a shape will be described later in detail, but is to form the sputtered shield film by a lift-off technique. In order to have a reverse tapered end as shown in FIG. 10B, a resist for reverse taper, for example, ZPN-1100 made by Zeon Corporation or A made by Client Corporation
After normal pre-bake / exposure using Z5214E,
It can be formed by heating (reversal baking) and excessive exposure (reversal exposure) at a temperature of 10 ° C. FIG. 11 (b)
In the formation of a resist having a two-layer structure as shown in the above, the first layer is usually used as an antireflection film, for example, Brewer Science
ARC manufactured by the company, a commonly used resist such as AZ6108 manufactured by Client Co., Ltd. is used for the upper layer, and the exposure is performed by a method performed in a normal process. Only the ARC is removed to form a two-layer resist shape in which the upper layer protrudes.

Such resist films 125b and 125c
The soft magnetic thin film 124 forming the upper shield is formed by sputtering through the mask described in FIG. It should be noted here that since the MR element 11 has already been formed, a heat treatment step at a high temperature as performed in the lower shield cannot be required. For this reason, the soft magnetic thin film 124 used as the upper shield has a limitation that the material must be heat-treated at 350 ° C. or less, which is the heat-resistant temperature of the MR element, or a material exhibiting soft magnetism without heat treatment. From this, it is conceivable to use a Co-based amorphous material as the soft magnetic thin film 124. In the case of a Co-based amorphous film, for example, CoZrNbTa, CoaZr
As bNbcTad (a, b, c, and d are atomic%), 6
8 ≦ a ≦ 90, 0 ≦ b ≦ 10, 0 ≦ c ≦ 20, 0 ≦ d ≦
10, soft magnetic properties are excellent when a + b + c + d = 100. In particular, 79 ≦ a ≦ 83, 2 ≦ b ≦ 6, and 10 ≦ c ≦ 1.
4, 1 ≦ d ≦ 5, a + b + c + d = 100, excellent heat resistance and wear resistance can be obtained. By using this composition, uneven wear can be reduced, spacing loss can be reduced, high output can be maintained, and the life of the head can be extended. Except for the composition here, instead of Ta, M
o, Cr, TiHf, Pd, W, V, etc., and their composites are conceivable.

Further, in order to enhance the soft magnetic characteristics, the upper soft magnetic thin film may have a laminated structure. In the laminated film, a soft magnetic film and a non-magnetic film are alternately deposited, and the soft magnetic films perform magnetostatic coupling, so that a domain wall is not generated. For this reason, it is possible to suppress a delay in response to a high frequency due to the domain wall movement and generation of noise. Although SiO ₂ was used for the non-magnetic film, it is not limited to this material, and any film may be used as long as it can electrically and magnetically insulate. Specifically, the thickness of the magnetic layer is 0.28 μm, the thickness of the nonmagnetic layer is 5 nm, and the magnetic layer and the nonmagnetic layer are alternately deposited so that the number of the magnetic layers becomes 10, and the total thickness is 3 μm.
Degree. In order to stabilize the characteristics of the amorphous magnetic film, it is preferable to deposit Cr or the like to a thickness of several nm on the underlayer of the magnetic layer.

Thereafter, the resist films 125b and 125c shown in FIG. 10 or FIG. 11 are removed together with the soft magnetic film sputtered thereon, thereby completing the formation of the soft magnetic thin film 124 forming the upper shield. . The resist films 125b, 1c are simultaneously formed with the resist films 125b, 125c.
Removing the material formed on the surface 25c and leaving only the portion not covered with the resist is called a lift-off technique. A reverse tapered type or a two-layer resist shape is required. That is, a material to be formed is divided by these shapes, and a solvent for removing the resist enters from the divided portion, whereby clear patterning can be performed.

The soft magnetic thin film 124 forming the upper shield
After the formation, as shown in FIGS. 12A and 12B,
Using photolithography technology, the external connection terminals 15a and 15b for connecting to an external circuit are connected to the terminals 1 described above.
15a 'and 115b' are formed on the ends. Specifically, for example, first, a mask having an opening in a portion to be the external connection terminals 15a and 15b is formed using photoresist. Subsequently, etching is performed to remove the non-magnetic and non-conductive film 116 at the portion exposed to the opening, that is, the portion to be the external connection terminals 15a and 15b.
The ends of 15a 'and 115b' are exposed. Then, while the photoresist mask is left as it is, a conductive film is formed thereon. Here, the conductive film is formed by, for example, electrolytic plating using a copper sulfate solution so that Cu has a thickness of about 6 μm. The conductive film may be formed by a method other than the electrolytic plating as long as it does not affect other films. After that, the photoresist serving as a mask is removed together with the conductive film formed on the photoresist. Thereby, the external connection terminal 15
a, 15b are formed. The length t12 of the external connection terminals 15a and 15b is, for example, about 50 μm.
m. The width t13 of the external connection terminals 15a and 15b is the same as the width t8 of the terminals 115a 'and 115b', for example, about 80 μm.

After the external connection terminals 15a and 15b are formed, a protective film 126 is formed on the entire surface in order to shut off the entire MR element from the outside. MR explained in this embodiment
The position of the MR element 11 between the hard non-magnetic substrates 13 and 14 of the head is determined by the formation of the protective film 126.

The MR element 11 and the hard non-magnetic substrates 13 and 14
As described above, the positional relationship between (1) that the MR element 11 is located at a substantially apex of an arc on the sliding surface 10;
(2) It is characterized in that an intermediate point between the hard non-magnetic substrates 13 and 14 is shifted from the arc-shaped apex toward the magnetic tape discharge side (see FIG. 1). Of these, the position of (1) is also determined when the sliding surface 10 is formed, as described later.

On the other hand, regarding (2), in other words, taking the contents of (1) into consideration, in other words, it can be said that the intermediate point between the hard non-magnetic substrates 13 and 14 is positioned closer to the tape ejection side than the MR element 11. That is, assuming that the hard non-magnetic substrate 14 in the magnetic tape discharge direction is a substrate 141 described later, the substrate 131
The distance between the substrate 141 and the MR element 11 is larger than the distance between the substrate 141 and the MR element 11. However, the substrate 141 is
As will be described later, it is directly bonded to the surface of the protective film 126. Therefore, the distance between the substrate 141 and the MR element 11 is a thickness obtained by subtracting the thickness of the upper shield from the protective film 126 (hereinafter, this thickness is referred to as “distance between the MR element and the substrate”).

At the time of forming the protective film 126, its thickness is determined in consideration of the above points, that is, the point relating to the above (2). The distance between the substrate 131 and the MR element 11 is the thickness of the substrate surface improvement film 132 + the thickness of the lower film shield 123 + the thickness of the lower layer gap 111, for example, about 1+
2.5 + 0.1 = 3.6 μm. Therefore, it is necessary to make the “distance between the MR element and the substrate” larger than 3.6 μm. Since the “distance between the MR element and the substrate” is 3 μm of the thickness of the upper shield 124 +0.1 μm of the thickness of the upper gap 116 + the thickness of the protective film 126, the thickness of the protective film 126 needs to be 0.5 μm or more.

Here, the portion where the thickness of the protective film 126 is required to be 0.5 μm or more is a portion exposed on the sliding surface 10. That is, the portion remaining on the upper shield 124 needs to be 0.5 μm or more. However, in order to flatten the entire MR head, it is necessary to completely fill the unevenness of the upper shield or the like. Therefore, first, it is necessary to form the protective film 126 to a thickness of at least about 4 μm. Specifically, for example, by sputtering, Al ₂
O ₃ is formed to a thickness of about 4 μm. In addition,
As the material of the protective film 126, any material other than Al ₂ O ₃ can be used as long as it is a non-magnetic and non-conductive material. However, considering environmental resistance and abrasion resistance, Al ₂ O ₃ is preferable. It is. Also,
The method for forming the protective film 126 may be a method other than sputtering, and may be formed, for example, by vapor deposition or the like. Then, the external connection terminal 15
The protective film 126 covering the entire surface is polished until the surfaces a and 15b are exposed. The polishing here is performed by, for example, using a diamond abrasive having a particle size of about 2 μm to form the external connection terminal 15.
After roughly polishing until the surfaces of a and 15b are exposed,
The surface is mirror-finished by buffing with silicon abrasive grains.

The thickness of the protective film 126 on the upper shield is finally determined by the polishing at this time. As described above, this thickness needs to be 0.5 μm or more. From this, it is conceivable that the thickness of the protective film 126 is polished so as to be, for example, 1 μm.

After the formation of the protective film 126 in this manner, the substrate is cut into strips as shown in FIG. A block 21 in which the MR elements 11 are arranged in a horizontal direction is formed. The number of MR elements 11 arranged in the horizontal direction is preferably as large as possible in consideration of productivity. Although only five are shown in the figure for simplicity, more than five may be used in practice. The width t14 of the block 21 is 2 mm.

After the blocks 21 cut into strips are formed, a substrate 141 having a thickness t15 of, for example, about 0.7 mm is attached to the cut blocks 21 as shown in FIG. An adhesive such as a resin may be used for attaching the substrate 141. At this time, the substrate 1
The height t16 of 41 is made smaller than the height t14 of the first substrate 131 so that the external connection terminals 15a and 15b are exposed, and electrical connection to these terminals can be performed. The same material as the substrate 131 is used for the substrate 141.

After the attachment of the substrate 141, the sliding surface 10 is formed as shown in FIG. That is, the sliding surface 1
Grinding is performed on the surface which becomes 0 so as to form a substantially circular arc. Specifically, the front end of the MR element 11 is exposed on the sliding surface 10 and the depth d of the MR element 11 is
Until the initial stage (for example, 7 μm), that is, M
Cylindrical polishing is performed on the element row 22 after the substrate 141 is attached, until the end of the R element 11 appears near the sliding surface 10 side. Thereby, the sliding surface 10 is formed into a substantially arc-shaped curved surface. Since the polishing at this time is in the roughing stage, the depth of the MR element 11 which is finally required + 1 μm
Up to the extent.

When the polishing in the roughing stage is completed, the azimuth angle θ required by the system is applied as shown in FIG. Cut.

After separation into the respective MR heads, the final formation of the surface of the sliding surface 10 is individually performed using a polishing tape.
That is, mechanical processing using a polishing tape is performed until the depth width of the MR element 11 finally required for each head is obtained. Here, formation is performed so that the MR element 11 becomes the vertex of the arc of the sliding surface 10, that is, in consideration of the above (1).

The final formation of the sliding surface 10 is shown in FIG.
As shown in (1), the polishing tape 31 is moved in one direction on the surface of the sliding surface 10 while tension is applied to the sliding surface 10 by the guides of the two guide pins 32. As the polishing tape 31, for example, a mixture of chromium oxide and diamond having an abrasive system of about 0.3 μm is used. Although a mechanical forming method using the polishing tape 31 is shown here, the present invention is not limited to this method, and a thin film process such as chemical grinding or ion etching may be used.

The curvature R of the sliding surface 10 and its arc shape are determined when the tension of the polishing tape 31 is constant, as shown in FIG. It depends on the deviation amount N of the head from the center between the two guide pins 32. If the protrusion amount M is large, the curvature R becomes small, and if the protrusion amount M becomes small, the curvature R becomes large. Further, as the deviation amount N from the center shifts toward the polishing tape entry side, the arc top shifts toward the polishing tape discharge side, and as the deviation amount N shifts toward the polishing tape discharge side, the arc top shifts toward the polishing tape entry side.

That is, the relationship between the amount N of displacement of the head from the center between the guide pins 32 and the position of the apex of the arc with respect to the amount of displacement is, for example, as shown in FIG. Which can be approximated). However, since this relationship changes depending on the tension of the polishing tape 31 or the like, it is necessary to measure each polishing apparatus and grasp it in advance. Based on such a relationship, the final sliding surface 1
When the zero surface is formed, the head displacement N from the center between the guide pins 32 is adjusted, and polishing is performed so that the MR element 11 is located at the vertex of the arc of the sliding surface 10.

The MR head according to the embodiment shown in FIG. 1 is manufactured by the above-described procedure. And
When using the MR head, the MR head is attached to the chip base and the external connection terminals 15a, 15
5b and terminals provided on the chip base are electrically connected, and these are attached to the rotating drum 2a of the magnetic tape device 1. However, at this time, the MR head is required to be arranged on the rotating drum 2a such that the sliding with respect to the magnetic tape TP is defined and the substrate 131 side is located on the entry side of the magnetic tape TP.

As described above, the MR head according to the present embodiment allows the high-speed and long-time traveling with the magnetic tape TP by defining the positional relationship between the hard non-magnetic substrates 13 and 14 and the position of the MR element 11. Even in the state after the operation, the running state with the magnetic tape TP can be kept good, and a long life, high sensitivity, and high density can be realized. FIG. 20 shows a specific example of the measurement result of the transition of the head output at a high density of 24 MHz with respect to the traveling time. As is clear from the figure, according to the MR head described in the present embodiment, the conventional head (the MR element is located closer to the tape discharge side than the arc point of the sliding surface, and the center between the substrates is substantially the same as the arc vertex position) It can be confirmed that a high output is maintained even after traveling for a long time as compared with the same head, and a good contact state with the magnetic tape can be realized.

In this embodiment, each member constituting the MR head, its material, size, film thickness, etc.
Although a specific example has been described, the present invention is not limited to this, and an appropriate device may be used according to the requirements of the system. For example, in the present embodiment, a so-called shield type SAL having a structure similar to that of an MR head practically used in a hard disk device or the like is used.
Although the bias type MR head has been described, the bias method and the like are not limited to this. Further, the present invention can be applied to not only a magnetic scan type magnetic tape device but also a fixed type magnetic tape device which slides at high speed. Further, as the MR element, a device having a large resistance change rate such as a GMR (Giant MR) or a spin valve can be applied.

[0071]

As described above, when the magnetic head according to the present invention is used in a system in which a magnetic tape is used as a recording medium, the discharge side of the magnetic tape is deeply recessed after a long time running of the magnetic tape. Even if uneven wear occurs,
Since the position of the MR element is closer to the entry side of the magnetic tape, the degree of gouging at the position of the MR element can be suppressed, and an increase in the amount of spacing can be suppressed. Further, since the suppression is realized by the position of the MR element between the pair of hard non-magnetic substrates,
It is also possible to appropriately set the shape of the sliding surface, the position of the MR element on the sliding surface, and the like, whereby it is possible to cope with the occurrence of uneven wear and the suppression of changes in the spacing amount. Therefore, the magnetic head according to the present invention maintains a good contact state for a long period of time, and achieves a high sensitivity and a high density stable characteristic in which a high output can be obtained even in a high density recording / reproducing. It becomes suitable for.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram showing an example of a thin film laminated structure in a magnetic head according to the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of an example of a system using a magnetic head according to the present invention.

FIGS. 3A to 3C are explanatory diagrams showing a relationship between a configuration of a sliding surface of a magnetic head and a wear state thereof, and FIGS. 3A to 3C are diagrams of specific examples.

FIG. 4 is a diagram (part 1) for explaining a manufacturing procedure of the magnetic head according to the present invention, in which (a) forms a soft magnetic film on a substrate and then forms a photoresist pattern in a shield shape; It is a top view showing the state where it did, and (b) is the side view.

FIG. 5 is a diagram (part 2) for explaining a manufacturing procedure of the magnetic head according to the present invention, and (a) is a plan view showing a state after a thin film for a magnetoresistive element is formed; ,
(B) is a side view thereof.

FIG. 6 is a view (No. 3) for explaining the procedure for manufacturing the magnetic head according to the present invention, and is a plan view showing a state in which a permanent magnet film is embedded in a thin film for a magnetoresistive element.

FIGS. 7A and 7B are diagrams (part 4) for explaining the manufacturing procedure of the magnetic head according to the present invention; FIG. 7A is an enlarged plan view of a portion corresponding to one head element in FIG. 6;
(B) is the XX sectional drawing.

FIG. 8 is a view (No. 5) for explaining the manufacturing procedure of the magnetic head according to the present invention; FIG. 8A shows a portion corresponding to one head element in an etching state of the thin film for the magnetoresistive element; FIG. 4 is an enlarged plan view, and FIG.
It is -X sectional drawing.

FIGS. 9A and 9B are diagrams (part 6) for explaining the manufacturing procedure of the magnetic head according to the present invention, in which FIG. 9A shows a state where a non-magnetic non-conductive film to be an upper layer gap of the head element is formed; FIG. 3 is an enlarged plan view of a portion corresponding to one head element, and FIG.

FIG. 10 is a view (No. 7) for explaining the manufacturing procedure of the magnetic head according to the present invention, in which (a) is a plan view showing the shape of a resist formed in a reverse taper type for performing lift-off; (B) is an XX cross-sectional view thereof.

FIG. 11 is a view (No. 8) for explaining the manufacturing procedure of the magnetic head according to the present invention, wherein (a) is a plan view showing the shape of a resist formed in a two-layer structure in order to perform lift-off; (B) is an XX cross-sectional view thereof.

FIG. 12 is a view (No. 9) for explaining the manufacturing procedure of the magnetic head according to the present invention; FIG. 12A is a view illustrating a method of forming a protective film and polishing the protective film until an external connection terminal is exposed; It is a top view which shows the state which carried out, and (b) is the XX sectional drawing.

FIG. 13 is a view (No. 10) for explaining the manufacturing procedure of the magnetic head according to the present invention, which is a schematic view showing a state where the hard nonmagnetic substrate on which the head element is formed is cut into blocks.

14 is a view (No. 11) for explaining the procedure for manufacturing the magnetic head according to the present invention, and is a perspective view showing a state in which a hard non-magnetic substrate is attached to the block in FIG. 13;

FIG. 15 is a view (No. 12) for explaining the procedure for manufacturing the magnetic head according to the present invention, and is a perspective view showing a state in which the upper surface of the block in FIG. 14 is processed into an arc shape.

FIG. 16 is a diagram (No. 13) for explaining the manufacturing procedure of the magnetic head according to the present invention, and is a schematic diagram showing a state in which the block in FIG. 15 is divided for each head element.

FIG. 17 is a view (No. 14) for explaining the manufacturing procedure of the magnetic head according to the present invention, and is a schematic view showing a schematic configuration of a polishing apparatus for polishing a sliding surface of the magnetic head.

FIG. 18 is a view (No. 15) for describing the procedure for manufacturing the magnetic head according to the present invention, and is an enlarged schematic view of the head part of the polishing apparatus of FIG.

FIG. 19 is a view (No. 16) for explaining the procedure for manufacturing the magnetic head according to the present invention, and is an explanatory view showing a specific example of the relationship between the amount of head displacement and the position of the arc apex with respect to the amount of displacement.

FIG. 20 is an explanatory diagram showing a specific example of a relationship between a running time and an output in the magnetic head according to the present invention.

FIG. 21 is a perspective view showing a schematic configuration of an example of a rotary drum on which a magnetic head according to the present invention is mounted.

FIG. 22 is a sectional view showing an example of a thin-film laminated structure in a conventional magnetic head.

FIG. 23 is an explanatory diagram showing a specific example of the relationship between the position of the magnetic head and the spacing.

FIG. 24 is an explanatory diagram showing an example of a state in which uneven wear has occurred on a magnetic head due to sliding with a magnetic tape.

[Explanation of symbols]

2 magnetic head device, 2a rotating drum, 10 sliding surface, 11 MR element, 12 soft magnetic thin film, 13, 14 ...
Hard non-magnetic substrate, RH1, RH2 ... reproducing head (MR head), TP ... magnetic tape

Claims (3)

[Claims] 1. A magnetic head mounted on a rotating head of a system using a magnetic tape as a recording medium and having a magnetoresistive head element for reproduction, wherein the magnetic head has a substantially arc-like shape which slides with the magnetic tape. Along with a sliding surface, the sliding surface is configured in a thin film laminated structure in which the head element is stacked along the running direction of the magnetic tape in a form in which a pair of hard non-magnetic substrates are sandwiched via a soft magnetic material. The distance between the hard non-magnetic substrate on the entry side of the magnetic tape and the head element is formed smaller than the distance between the hard non-magnetic substrate on the ejection side of the magnetic tape and the head element. A magnetic head. 2. The magnetic tape according to claim 1, wherein an intermediate point between the pair of hard non-magnetic substrates is located closer to a discharge side of the magnetic tape than a substantially arc-shaped apex of the sliding surface. Magnetic head. 3. The magnetic head according to claim 1, wherein the head element is disposed near a substantially arc-shaped apex on the sliding surface.