JPH11120512A - Thin-film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film magnetic head formed in such a manner that write fringing may be sufficiently suppressed by a skin effect and further the lowering in leakage magnetic field strength may be held to the utmost. SOLUTION: A nonmagnetic conductive layer consisting of, for example, Cu, etc., is deposited from the front surface of a lower core layer 1 to the front ends of a gap layer 2 and an upper core layer. Then, the leaking magnetic fields protruding from a track width Tw among the leakage magnetic fields generated between the lower core layer 1 and the upper core layer are suppressed by the skin effect and the suppression of the occurrence of the write fringing is made possible and the lowering in the leakage magnetic field strength is held to the utmost. The requirement to make the write fringing quantity smaller is to use a nonmagnetic conductive material of lower specific resistance and to make a recording frequency higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductive thin film magnetic head used for a floating magnetic head, for example, and more particularly to a thin film magnetic head capable of suppressing the occurrence of write fringing.

[0002]

2. Description of the Related Art FIG. 6A is a partial front view showing a conventional thin film head viewed from a side facing a recording medium. FIG.
The thin-film magnetic head shown in (a) is formed at the trailing side end of a slider constituting a floating head, and has a read head and a recording inductive head laminated. Reference numeral 1 denotes a lower core layer formed of a magnetic material having a high magnetic permeability such as a NiFe alloy (Permalloy) or Sendust. In a composite thin film magnetic head in which an inductive head is continuously stacked on a read head using a magnetoresistive element, the lower core layer 1 functions not only as a core layer of the inductive head but also as an upper shield of the read head. It also functions as a layer.

On the lower core layer 1, a gap layer 10 made of a nonmagnetic material such as Al ₂ O ₃ (alumina) is provided. On the gap layer 10, an insulating layer (not shown) made of, for example, a resist material or another organic material is formed. On the insulating layer, a coil layer (not shown) is spirally formed of a conductive material having a low electric resistance such as Cu.

[0004] An insulating layer (not shown) of an organic resin material or the like is formed on the coil, and on the insulating layer,
An upper core layer 6 of a magnetic material is formed. As shown in FIG. 6 (a), the tip 6a of the upper core layer 6 is joined to the lower core layer 1 via a gap layer 10 to form a recording magnetic gap having a gap length Gl. . The width of the tip 6a is substantially the same as the track width Tw.

[0005] In this inductive head for recording,
When a recording current is applied to the coil layer, a recording magnetic field is induced in the lower core layer 1 and the upper core layer 6, and a leakage magnetic field from a magnetic gap portion between the lower core layer 1 and the tip 6a of the upper core layer 6 causes A recording signal is recorded on a recording medium such as a hard disk. In the read head formed below the inductive head, a magnetoresistive element layer 13 is provided on a lower shield layer 11 via a lower gap layer 12a, as shown in FIG. The lower core layer 1 is formed on an upper gap layer 13 via an upper gap layer 12b. As described above, in the read head, the lower core layer 1 functions as an upper shield layer.

[0006]

Recently, the track width Tw tends to be reduced with the increase in the recording density. However, when the track width Tw is reduced, the tip portions 6a of the lower core layer 1 and the upper core layer 6 become smaller. In this case, there arises a problem that the intensity of the leakage magnetic field within the track width Tw occurring between the two decreases. FIG. 7 is a graph showing the relationship between the track width Tw and the leakage magnetic field strength. As shown in FIG.
It can be seen that the leakage magnetic field intensity sharply decreases when the value is about 3 μm or less. The reason why the leakage magnetic field intensity (recording magnetic field intensity) within the track width Tw decreases as the track width Tw becomes narrower is that the leakage magnetic field between the lower core layer 1 and the upper core layer 6 is reduced by the track width. This is because it is easy to leak out of the track width Tw, as well as within the width Tw.

FIG. 6 (b) shows a recording pattern 14 when magnetic data is recorded on a recording medium using the inductive head shown in FIG. 6 (a). Track width T
When w becomes small, on both sides of the recording pattern 14,
Write fringing (writing bleeding) protruding from the original track width Tw is likely to occur. As a result, as described above, the leakage magnetic field intensity within the track width Tw is reduced, and the recording pattern written on the recording medium is reduced. 14 has a substantial width Tf wider than the track width Tw. When the write fringing occurs, the track position cannot be accurately detected on the written recording medium, and a tracking servo error is likely to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and a thin-film magnetic recording medium capable of sufficiently suppressing write fringing by a skin effect and suppressing a decrease in leakage magnetic field intensity as much as possible. It is intended to provide a head.

[0009]

According to the present invention, a gap layer made of a non-magnetic material is formed between a lower core layer made of a magnetic material and an upper core layer having a predetermined width Tw. A thin-film magnetic head provided with magnetic generating means for inducing a recording magnetic field in the upper core layer, wherein the non-magnetic conductive layer covers both sides of the gap layer in the track width direction and is formed from the lower core layer to the upper core layer. A layer is provided.

In the above, the gap layer is formed with the same width Tw as the upper core layer, and the nonmagnetic conductive layer is formed from the upper surface of the lower core layer to both side surfaces of the gap layer and the upper core layer. May be available.

The gap layer is formed to have the same width Tw as the upper core layer, and the lower core layer has a raised portion having a width T2 substantially equal to the width Tw at a portion in contact with the gap layer. And the nonmagnetic conductive layer may be formed from an upper surface of the lower core layer to both side surfaces of the ridge, the gap layer, and the upper core layer.

The present invention also provides a lower core layer of a magnetic material,
A thin-film magnetic head comprising a gap layer made of a non-magnetic material formed between an upper core layer having a predetermined width Tw, and a magnetic generating means for inducing a recording magnetic field in the lower core layer and the upper core layer. Wherein the gap layer is formed with a length substantially equal to the gap depth Gd, and the nonmagnetic conductive layer is formed from the lower core layer to the back surface of the gap layer and the upper core layer. It is.

As described above, in the present invention, the nonmagnetic conductive layer is formed not only from the lower core layer to both side surfaces of the upper core layer, but also from the lower core layer to the back surface of the upper core layer. Is also good.

In the present invention, the thickness of the nonmagnetic conductive layer is:
0.3 to 2.0 μm, and at least the skin thickness S at the recording frequency when the thin film magnetic head is driven.
(S is as shown in Equation 1). Here, μ is the magnetic permeability, f is the recording frequency, and ρ is the specific resistance.

Further, in the present invention, the nonmagnetic conductive layer is preferably made of A
It is preferable to be formed of one or more of u, Ag, Cu, and Pt.

In the present invention, when the nonmagnetic conductive layer is formed of Au or Cu and the recording frequency is 50 MHz or more, the thickness of the nonmagnetic conductive layer is about 0.9 to 2.0.
It is preferably within the range of μm.

Further, the nonmagnetic conductive layer is made of Au or C
When the recording frequency is 100 MHz or more, the thickness of the nonmagnetic conductive layer is preferably in the range of about 0.6 to 2.0 μm.

Further, when the nonmagnetic conductive layer is formed of Au or Cu and the recording frequency is 500 MHz or more, the thickness of the nonmagnetic conductive layer is about 0.3 to 2.0 μm.
Is preferably within the range.

When the nonmagnetic conductive layer is made of Ag and the recording frequency is 50 MHz or more, the thickness of the nonmagnetic conductive layer is in the range of about 1.0 to 2.0 μm. Is preferred.

When the nonmagnetic conductive layer is formed of Ag and the recording frequency is 100 MHz or more, the thickness of the nonmagnetic conductive layer may be in the range of 0.7 to 2.0 μm. preferable.

Further, when the non-magnetic conductive layer is formed of Ag and the recording frequency is 500 MHz or more, the thickness of the non-magnetic conductive layer is in the range of about 0.3 to 2.0 μm. Is preferred.

When the nonmagnetic conductive layer is formed of Pt and the recording frequency is 100 MHz or more, the thickness of the nonmagnetic conductive layer may be in the range of about 1.8 to 2.0 μm. preferable.

In the present invention, a nonmagnetic conductive layer having a low specific resistance is formed from the upper surface of the lower core layer to both side surfaces of the upper core layer, and the leakage magnetic field oozing out of the track width Tw is suppressed by the skin effect, thereby reducing the light fringe. In addition, the reduction of the leakage magnetic field strength is suppressed as much as possible.

Here, the skin effect refers to a phenomenon in which a high-frequency current or an electromagnetic wave is limited to the surface layer of the conductor and does not enter the inside.

That is, in the present invention, for example, among the leakage magnetic fields generated between the lower core layer 1 and the upper core layer 6 shown in FIG. 1, the leakage magnetic field that does not fall within the track width Tw is caused by the skin effect. Only the surface layer of the non-magnetic conductive layer 7 is transmitted, so that write fringing can be suppressed more sufficiently than in the conventional case, and the leakage magnetic field intensity does not decrease as compared with the conventional case.

The thickness T1 of the nonmagnetic conductive layer 7
Is determined to be equal to or greater than the skin depth.

Here, the skin thickness means a thickness at which the strength of the magnetic field becomes 1 / e of the surface. The skin thickness S can be obtained by the relational expression of Expression 1, but it is preferable that the skin thickness is as small as possible in that the light fringing amount can be further reduced. As can be seen from the above equation, in order to make the skin thickness as thin as possible, the specific resistance ρ
It is necessary to select a material having a small magnetic field, and the effect becomes higher as the frequency f of the magnetic field to be used is higher.

That is, according to the present invention, as the recording frequency becomes higher, the skin effect can be more exerted, and the write fringing amount can be reduced.

[0029]

FIG. 1 is a partial front view showing the structure of a thin film magnetic head according to a first embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view of the thin-film magnetic head shown in FIG.
FIG. 2 is a partial front view showing the structure of the thin-film magnetic head of the embodiment. The thin-film magnetic head shown in FIGS. 1 and 3 is a so-called inductive head for writing. Under the inductive head, the magnetoresistive element layer 13 shown in FIG.
And a read head having a lower shield layer 11.

Reference numeral 1 shown in FIG. 1 denotes a lower core layer 1 formed of a soft magnetic material having a high magnetic permeability such as a NiFe alloy (permalloy). The lower core layer 1 also functions as an upper shield layer of the above-described read head. On the lower core layer 1, a gap layer 2 made of an insulating material is formed. The width dimension of the gap layer 2 is
The upper core layer 6 has a width substantially equal to a width (track width Tw) of an upper core layer 6 described later.

Further, as shown in FIG.
Is approximately the same as the magnetic gap depth Gd. Further, as shown in FIG. 2, an insulating layer 3 of an organic resin material, for example, a resist material is formed on the lower core layer 1, and a conductive material having a small electric resistance such as Cu is formed on the insulating layer. A spiral coil layer 4 is formed. Further, an insulating layer 5 made of an organic resin material is formed on the coil layer 4.

An upper core layer 6 made of a magnetic material such as permalloy is formed on the insulating layer 5.
The tip 6a of the upper core layer 6, as shown in FIG.
A magnetic gap having a gap length G1 is formed on the opposing surface of the lower core layer 1 via a gap layer 2. The width of the tip 6a of the upper core layer 6 is determined to be the same as the track width Tw. As shown in FIG. 1, a nonmagnetic conductive layer 7 is formed from the upper surface of the lower core layer 1 to both side surfaces of the gap layer 2 and the upper core layer 6 and the upper surface of the upper core layer 6.

In the present invention, the thickness T of the nonmagnetic conductive layer 7
1 is preferably in the range of 0.3 to 2.0 μm. When the film thickness T1 of the nonmagnetic conductive layer 7 is 2.0 μm or more, the possibility of the film peeling of the nonmagnetic conductive layer 7 increases due to film stress, which is not preferable. When the thickness T1 of the non-magnetic conductive layer 7 is 0.3 μm or less, the non-magnetic conductive layer 7 is hardly formed on both sides of the gap layer 2 shown in FIG. It is not preferable because it cannot be suppressed.

In the present invention, the lower limit of the thickness T1 of the nonmagnetic conductive layer 7 is set to 0.3 μm because the gap length Gl is about 0.3 μm. That is, if the gap length Gl is further reduced, the lower limit of the film thickness T1 of the nonmagnetic conductive layer 7 can be reduced accordingly. Further, in the present invention, the thickness T1 of the nonmagnetic conductive layer 7 is
Must be formed to have a thickness equal to or greater than the skin thickness at the recording frequency when the thin-film magnetic head is driven. The skin thickness S is the number 1
Can be obtained by the following relational expression. This skin thickness S
When the boundary surface between the nonmagnetic conductive layer 7 and the gap layer 2 is the surface 7a of the nonmagnetic conductive layer 7, the strength of the magnetic field in the nonmagnetic conductive layer 7 becomes 1 / e of the strength of the surface 7a. Means a depth from the surface 7a at a certain position. Note that e is the base of the natural logarithm.

At least the thickness T 1 of the nonmagnetic conductive layer 7
However, if it is not formed with the skin thickness S or more, the effect of suppressing the leakage magnetic field protruding from the track width Tw cannot be expected to sufficiently suppress the occurrence of write fringing. As can be seen from the above equation, by using a material having the smallest possible resistivity ρ and using it in a region where the recording frequency f is high, the skin thickness can be reduced, and the amount of light fringing can be increased. Can be reduced. Note that the magnetic permeability μ
Is approximately 1.

In the present invention, as shown in FIG. 2, the nonmagnetic conductive layer 7 is
And it may be formed over the back surface of the upper core layer 6. In this case, the thickness T1 of the nonmagnetic conductive layer 7 is also
It must be formed in the range of 0.3 to 2.0 [mu] m, and the film thickness T1 must be at least the skin thickness S or more.

The method of forming the nonmagnetic conductive layer 7 from the upper surface of the lower core layer 1 to the back surface of the upper core layer 6 is as follows. First, the length dimension is set on the lower core layer 1 where the gap layer 2 is formed. A non-magnetic conductive layer 7 is formed on the rear side of the resist layer. The height dimension h1 of the nonmagnetic conductive layer 7 is determined by the gap length Gl.
Must be larger than further,
Upper surface of the nonmagnetic conductive layer 7 and the nonmagnetic conductive layer 7
The insulating layer 3 is formed on the upper surface of the lower core layer 1 on the rear side, and the coil layer 4 and the insulating layer 5 are formed on the insulating layer 3.
Is formed.

Then, the resist layer is removed, a gap layer 2 is formed in a portion where the resist layer is removed, and an upper core layer 6 is formed from the gap layer 2 to the upper surface of the insulating layer 5. As described above, since the nonmagnetic conductive layer 7 is formed from the upper surface of the lower core layer 1 to the back surface of the upper core layer 6, the recording magnetic field leaking from the back side can be suppressed, and the strength of the leakage magnetic field can be further increased. Becomes possible.

In the present invention, Au, Ag, Cu, Pt can be presented as a material constituting the nonmagnetic conductive layer 7. However, the present invention is not limited to these materials, and any non-magnetic conductive material having a low specific resistance can be used as the non-magnetic conductive layer 7. In the present invention, Au, Ag, Cu, and Pt are used to determine the frequency and the skin thickness (skin dept) for each element.
h) was examined. FIG. 4 shows the results.

As shown in FIG. 4, it can be seen that the skin thickness of Au, Ag, Cu, Pt decreases as the frequency increases. Pt has the largest skin thickness among the four elements, and Pt is Au, A
This is because it has a higher specific resistance ρ than g and Cu. For example, as the nonmagnetic conductive layer 7, Au or C
If u is used and the recording frequency is 50 MHz or higher,
The skin thickness S of the nonmagnetic conductive layer 7 is about 0.9 μm or less. Therefore, the thickness T1 of the non-magnetic conductive layer 7 is set to 0.1.
When the thickness is 9 μm or more, the skin thickness can be maintained at S or more, and the effect of sufficiently suppressing light fringing by the skin effect can be effectively exhibited. As described above, the upper limit of the thickness T1 of the nonmagnetic conductive layer 7 is preferably 2.0 μm or less in order to prevent film peeling. Therefore, when the recording frequency is 50 MHz or more, the preferable range of the film thickness T1 is 0.9 to 2.0 μm.

When Au or Cu is used as the nonmagnetic conductive layer 7 and the recording frequency is 100 MHz or more, the skin thickness S at 100 MHz is about 0.6 μm or less. Thickness T1 is about 0.6
It is preferable that it is in the range of 2.0 μm. That is, if the film thickness T1 of the nonmagnetic conductive layer 7 is formed to be equal to or more than the skin thickness S, it is possible to sufficiently suppress the light fringing. Similarly, when the nonmagnetic conductive layer 7 is formed of Au or Cu and the recording frequency band is 500 MHz or more, the thickness T1 of the nonmagnetic conductive layer 7 is about 0.3 to
When the thickness is within the range of 2.0 μm, the thickness T1 of the nonmagnetic conductive layer 7 can be reliably maintained at or above the skin thickness.
Light fringing can be sufficiently suppressed by the skin effect.

Next, the nonmagnetic conductive layer 7 is formed of Ag,
When the recording frequency band is 50 MHz or more, the preferable range of the thickness T1 of the nonmagnetic conductive layer 7 is approximately 1.0 to 1.0.
2.0 μm. When the nonmagnetic conductive layer 7 is formed of Ag and the recording frequency is 100 MHz or more, the preferable range of the thickness T1 of the nonmagnetic conductive layer 7 is 0.7
２．０2.0 μm.

Further, when the nonmagnetic conductive layer 7 is formed of Ag and the recording frequency is 500 MHz or more, the preferable range of the film thickness T1 of the nonmagnetic conductive layer 7 is about 0.3 to
2.0 μm. When the nonmagnetic conductive layer 7 is formed of Pt and the recording frequency is 100 MHz or more, the preferable range of the thickness T1 of the nonmagnetic conductive layer 7 is about 1.8.
２．０2.0 μm.

FIG. 5 is a graph showing the relationship between frequency and specific resistance when the skin thickness is 0.3 μm. For example, when the recording frequency is 50 MHz, it is understood that the specific resistance required for the nonmagnetic conductive material is about 0.003 (μΩ · cm) or less. For example, if the recording frequency is 100 MHz
, The specific resistance required for the non-magnetic conductive material is about 0.5.
006 (μΩ · cm) or less.

In other words, a nonmagnetic conductive material having a specific resistance of 0.006 (μΩ · cm) or more is used for the nonmagnetic conductive layer 7, and the film thickness T 1 of the nonmagnetic conductive layer 7 is 0.3 μm. In this case, if the recording frequency is 100 MHz or less, the thickness of the nonmagnetic conductive layer 7 cannot secure the skin thickness, and the problem that write fringing cannot be sufficiently suppressed occurs. . Conversely, the specific resistance is 0.00
3 (μΩ · cm) or less and a film thickness T1 of 0.3 μm or more, it can be used at a recording frequency of 50 MHz or more.
If 1 is 0.3 μm or more, it can be used at a recording frequency of 100 MHz or more.

As described above, according to the present invention, the nonmagnetic conductive layer 7 extends from the upper surface of the lower core layer 1 to both side surfaces of the upper core layer 6.
And the film thickness T1 of the nonmagnetic conductive layer 7 is formed to be at least the skin thickness at the recording frequency. Therefore, the leakage magnetic field oozing from the track width Tw is suppressed by the skin effect, and sufficient writing is performed. It is possible to suppress the occurrence of fringing. Recently, in order to cope with higher recording density, there is a tendency to increase the recording frequency at the same time as reducing the track width Tw. In particular, in the present invention, the skin depth can be reduced as the frequency band becomes higher. Therefore, it is possible to further reduce the amount of light fringing.

As described above, since the leakage magnetic field oozing from the track width Tw is suppressed by the skin effect, it is possible to suppress the decrease in the leakage magnetic field intensity as much as possible. Further, in the present invention, the nonmagnetic conductive layer 7 may be formed from the upper surface of the lower core layer 1 to the back surface of the upper core layer 6.
By forming the non-magnetic conductive layer 7 on the back side, it is possible to further increase the leakage magnetic field strength.

The thin-film magnetic head shown in FIG. 3 is different from the thin-film magnetic head shown in FIG. 1 only in the shape of the lower core layer 1, and the other portions have exactly the same shape. As shown in FIG. 2, the lower core layer 1 has a raised portion 1 having a width dimension T2 at a portion in contact with the gap layer 2.
a is formed. The raised portion 1a may be formed integrally with the lower core layer 1, or may be laminated on the lower core layer 1.

The width T2 of the raised portion 1a is substantially equal to the track width Tw of the tip 6a of the upper core layer 6 and the width of the gap layer 2. And
The non-magnetic conductive layer 7 extends from the upper surface of the lower core layer 1
a, the gap layer 2, and both side surfaces of the tip 6a and the upper surface of the tip 6a. The width dimension T1 of the nonmagnetic conductive layer 7 is 0.3
The thickness is formed within a range of about 2.0 μm and at least the skin thickness at the recording frequency at the time of driving the thin-film magnetic head. Therefore, the occurrence of light fringing can be sufficiently suppressed by the skin effect.

In the thin-film magnetic head shown in FIG. 3, since a leakage magnetic field is generated between the protruding portion 1a having the same width dimension T2 as the track width Tw and the tip portion 6a of the upper core layer 6, the non-magnetic thin film magnetic head is originally non-magnetic. Even if the magnetic conductive layer 7 is not formed, the fringing amount is estimated to be smaller than that of the thin-film magnetic head shown in FIG. 1, but the non-magnetic conductive layer 7 is formed as shown in FIG. By doing so, it is possible to manufacture a thin film magnetic head with a smaller write fringing amount.

According to the present invention, the nonmagnetic conductive layer 7 may be formed on the lower core layer 1 from the upper surface to the raised portion 1a, the gap layer 2, and the back surface of the upper core layer 6, thereby reducing the leakage magnetic field strength. It is possible to be stronger. Further, in the present invention, a nonmagnetic conductive layer 7 is formed from the upper surface of the lower core layer 1 of the thin-film magnetic head shown in FIG. 6 to both side surfaces of the tip 6a of the upper core layer 6 and the upper surface of the tip 6a. As a result, it is possible to suppress the occurrence of light fringing.

[0052]

According to the present invention described in detail above, a nonmagnetic conductive layer is formed from the upper surface of the lower core layer to both side surfaces of the upper core layer, so that the leakage magnetic field oozing from the track width is reduced by the skin effect. Thus, the occurrence of write fringing can be suppressed, and at the same time, a decrease in the leakage magnetic field strength can be suppressed as much as possible.

In particular, in the present invention, in order to further suppress the occurrence of light fringing, it is preferable to reduce the skin thickness, and therefore, as the nonmagnetic conductive layer, a nonmagnetic conductive material having a specific resistance as low as possible is used. It is preferable that the recording frequency be increased.

Further, in the present invention, the nonmagnetic conductive layer may be formed from the upper surface of the lower core layer to the back surface of the upper core layer, whereby the leakage magnetic field strength can be further increased.

[Brief description of the drawings]

FIG. 1 is a front view showing the structure of a thin-film magnetic head according to a first embodiment of the present invention;

2 is a longitudinal sectional view of the thin-film magnetic head shown in FIG. 1,

FIG. 3 is a front view showing the structure of a thin-film magnetic head according to a second embodiment of the present invention;

FIG. 4 is a graph showing the relationship between frequency and skin thickness in Au, Cu, Ag, and Pt;

FIG. 5 is a graph showing the relationship between frequency and specific resistance when the skin thickness is 0.3 μm;

FIG. 6 is a front view showing the structure of a conventional thin-film magnetic head;

FIG. 7 is a graph showing a relationship between a track width Tw and a leakage magnetic field intensity;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower core layer 1a Ridge part 2 Gap layer 3, 5 Insulating layer 4 Coil layer 6 Upper core layer 6a Tip part 7 Nonmagnetic conductive layer T1 Film thickness (of nonmagnetic conductive layer)

Claims (14)

[Claims] A lower core layer made of a magnetic material and a predetermined width Tw
A thin layer magnetic head comprising a gap layer made of a non-magnetic material formed between the upper core layer and the lower core layer, and a magnetic generating means for inducing a recording magnetic field in the lower core layer and the upper core layer. A thin-film magnetic head comprising a nonmagnetic conductive layer covering both sides of a layer in a track width direction and formed from a lower core layer to an upper core layer. 2. The gap layer is formed to have the same width Tw as an upper core layer, and the nonmagnetic conductive layer is formed from an upper surface of a lower core layer to both side surfaces of the gap layer and the upper core layer. The thin-film magnetic head according to claim 1. 3. The gap layer is formed with the same width dimension Tw as the upper core layer, and the lower core layer has a raised portion having a width dimension T2 substantially equal to the width dimension Tw at a portion in contact with the gap layer. 2. The thin-film magnetic head according to claim 1, wherein a portion is provided, and the nonmagnetic conductive layer is formed from an upper surface of the lower core layer to both side surfaces of the raised portion, the gap layer, and the upper core layer. 4. A lower core layer of a magnetic material and a predetermined width Tw
A thin layer magnetic head comprising a gap layer made of a non-magnetic material formed between the upper core layer and the lower core layer, and a magnetic generating means for inducing a recording magnetic field in the lower core layer and the upper core layer. The layer has a gap depth G
d. The thin-film magnetic head having a length substantially equal to d, wherein the nonmagnetic conductive layer is formed from the lower core layer to the back surface of the gap layer and the upper core layer. 5. The nonmagnetic conductive layer has a thickness of 0.3 to 0.3.
5. The thin-film magnetic head according to claim 1, wherein the thickness is within a range of 2.0 [mu] m. 6. The film thickness of the nonmagnetic conductive layer is at least a skin thickness S at a recording frequency when the thin film magnetic head is driven.
6. The thin-film magnetic head according to claim 5, formed as described above.
However, S is as shown in the following Equation 1. Μ is the magnetic permeability,
f is the recording frequency, and ρ is the specific resistance. (Equation 1) 7. The non-magnetic conductive layer is made of Au, Ag, C
7. The thin-film magnetic head according to claim 1, wherein the thin-film magnetic head is formed of one or more of u and Pt. 8. When the nonmagnetic conductive layer is made of Au or Cu and the recording frequency is 50 MHz or more, the thickness of the nonmagnetic conductive layer is in the range of about 0.9 to 2.0 μm. The thin-film magnetic head according to any one of claims 1 to 7. 9. When the nonmagnetic conductive layer is made of Au or Cu and has a recording frequency of 100 MHz or more,
8. The thin-film magnetic head according to claim 1, wherein the thickness of the nonmagnetic conductive layer is in a range of about 0.6 to 2.0 [mu] m. 10. The non-magnetic conductive layer is made of Au or Cu.
8. The thin film magnetic device according to claim 1, wherein when the recording frequency is 500 MHz or more, the thickness of the nonmagnetic conductive layer is in a range of about 0.3 to 2.0 [mu] m. head. 11. The non-magnetic conductive layer is formed of Ag,
The thin-film magnetic head according to any one of claims 1 to 7, wherein when the recording frequency is 50 MHz or more, the thickness of the nonmagnetic conductive layer is in a range of about 1.0 to 2.0 µm. 12. The non-magnetic conductive layer is formed of Ag,
The thin-film magnetic head according to any one of claims 1 to 7, wherein when the recording frequency is 100 MHz or more, the thickness of the nonmagnetic conductive layer is in a range of 0.7 to 2.0 µm. 13. When the nonmagnetic conductive layer is formed of Ag and the recording frequency is 500 MHz or more, the thickness of the nonmagnetic conductive layer is in the range of about 0.3 to 2.0 μm. A thin-film magnetic head according to any one of claims 1 to 7. 14. When the nonmagnetic conductive layer is formed of Pt and the recording frequency is 100 MHz or more, the thickness of the nonmagnetic conductive layer is in a range of about 1.8 to 2.0 μm. A thin-film magnetic head according to any one of claims 1 to 7.