JP2003242613A - Magneto-resistive effect sensor and thin-film magnetic head having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an MR sensor capable of maintaining a good correlation between dynamic characteristics and static characteristics without any deterioration of reproducing characteristics when high sensitivity and high resolution are set, and a thin-film magnetic head having the MR sensor. <P>SOLUTION: A lower shield layer 11, an upper shield layer 16 and an MR element 13 disposed between the lower and upper shield layers 11 and 16 are provided, a magnetic capacity of each of the lower and upper shield layers 11 and 16 is set to be equal to/lower than 8.8E-15Wbm, and a ratio of a magnetic capacity difference between the lower and upper shield layers 11 and 16 to the magnetic capacity of the upper shield layer 16 is 33% or lower. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a magnetoresistive effect (M) used as a reproducing head element for a magnetic disk device.
R) sensor and a thin film magnetic head provided with this MR sensor.

[0002]

2. Description of the Related Art In response to higher recording densities of magnetic disk devices, MR sensors for thin film magnetic heads are required to have higher sensitivity and higher resolution.

In order to achieve high sensitivity of the MR sensor,
Higher output and higher sensitivity of the MR film itself have been achieved, and optimization of the sensor structure such as the lead overlay structure in which the lead electrode is arranged to protrude inside the width of the MR film and the magnetic exchange coupling structure. Is being pursued. Further, in order to achieve high resolution of the MR sensor, a narrower shield gap is being promoted to further reduce the distance between the lower shield layer and the upper shield layer.

When designing and manufacturing this kind of thin film magnetic head, it is very important to measure and evaluate its magnetic characteristics. As a magnetic characteristic evaluation method for a magnetic head, there are generally a method for measuring and evaluating dynamic characteristics and a method for measuring and evaluating static characteristics.

The dynamic characteristic evaluation is to evaluate by evaluating the characteristics of the magnetic head in a state in which the magnetic head slider is attached to a suspension and is actually levitated on the recording medium, and the magnetic disk device is in a state close to the actual use environment. is there. On the other hand, the static characteristic evaluation is to measure and evaluate the characteristics of the magnetic head in a state where a uniform magnetic field generated by the magnetic field generating means is applied from the outside instead of the recording medium magnetic field.

The static characteristic evaluation method allows the characteristic evaluation under an environment different from the actual use environment of the magnetic disk device, and the characteristic evaluation without mounting the magnetic head on the suspension and without floating on the recording medium. It can be performed more easily than the dynamic characteristic evaluation method, and the evaluation can be performed at an early stage before the completion of the independent magnetic head in the manufacturing process. Therefore, it is possible to perform efficient product sorting, quick feedback to the magnetic head design, etc.
It is mainly used for evaluating the characteristics of read head elements.

[0007]

An important point in the static characteristic evaluation is that it has a good correlation with the dynamic characteristic evaluation performed in the actual use environment of the magnetic disk device.

However, if the sensitivity and resolution of the MR sensor are increased as described above, not only the correlation between the dynamic characteristic and the static characteristic is deteriorated, but also an external uniform magnetic field is used to measure the static characteristic. , The characteristics of the reproducing head element deteriorate and the noise contained in the reproduced signal increases.

Therefore, it is an object of the present invention to provide an MR sensor which does not deteriorate the reproduction characteristics even when the sensitivity and the resolution are increased, and a thin film magnetic head including the MR sensor.

Another object of the present invention is to provide an MR sensor capable of maintaining a good correlation between the dynamic characteristic and the static characteristic even when the sensitivity and the resolution are increased, and a thin-film magnetic sensor having the MR sensor. To provide the head.

[0011]

According to the present invention, there is provided a lower shield layer, an upper shield layer, and an MR element provided between the lower shield layer and the upper shield layer. An MR sensor and a reproducing head in which each layer has a magnetic capacity of 8.8E-15 Wbm or more, and a ratio of a magnetic capacity difference between the lower shield layer and the upper shield layer to a magnetic capacity of the upper shield layer is 33% or less. A thin film magnetic head provided with this MR sensor as an element is provided.

When the magnetic capacity of each of the lower shield layer and the upper shield layer is 8.8E-15 Wbm or more, the magnetic field resistance is improved, and even if an external uniform magnetic field for static characteristic measurement is applied, the MR sensor The reproduction magnetic characteristics do not deteriorate. Moreover, the ratio of the magnetic capacitance difference between the lower shield layer and the upper shield layer to the magnetic capacitance of the upper shield layer is 3
By setting it to 3% or less, the correlation between the static characteristic and the dynamic characteristic becomes very good.

It is preferable that the magnetic capacities of the lower shield layer and the upper shield layer are substantially equal to each other.

According to the present invention, it further comprises a lower shield layer, an upper shield layer, and an MR element provided between the lower shield layer and the upper shield layer, and each of the lower shield layer and the upper shield layer is provided. Air bearing surface (ABS)
The height from the ABS is 50 μm or more, and the ratio of the height difference from the ABS of the lower shield layer and the upper shield layer to the height of the upper shield layer is 33% or less. A thin film magnetic head including a sensor is provided.

The height of each of the lower shield layer and the upper shield layer from the ABS is 50 μm or more, and the ratio of the height difference from the ABS of the lower shield layer and the upper shield layer to the height of the upper shield layer is 33. % Or less, M
Concentration of the magnetic field on the R element and its bias magnetic field control film is avoided, the effective magnetic field applied to these MR element and bias magnetic field control film is reduced, and an external uniform magnetic field for static characteristic measurement is applied. Also, the reproduction magnetic characteristic of the MR sensor is not deteriorated, and the correlation between the static characteristic and the dynamic characteristic becomes very good.

According to the present invention, it further comprises a lower shield layer, an upper shield layer, and an MR element provided between the lower shield layer and the upper shield layer, each of the lower shield layer and the upper shield layer. Has a height from the air bearing surface of 50 μm or more, and the area of the air bearing surface side of each of the lower shield layer and the upper shield layer is 160 μm.
^There is provided a thin film magnetic head having ^two or more MR sensors and this MR sensor as a reproducing head element.

If the height of each of the lower shield layer and the upper shield layer from the ABS is 50 μm or more and the area of the ABS side surface of each of the lower shield layer and the upper shield layer is 160 μm ² or more, the MR element is formed. The concentration of the magnetic field on the bias magnetic field control film is avoided, and the effective magnetic field applied to the MR element and the bias magnetic field control film is reduced. As a result, even if an external uniform magnetic field for static characteristic measurement is applied, the reproduction magnetic characteristic of the MR sensor is not deteriorated, and the correlation between the static characteristic and the dynamic characteristic becomes very good.

It is preferable that the heights of the lower shield layer and the upper shield layer are substantially equal to each other.

[0019]

1 is a cross-sectional view schematically showing the structure of a main part of a thin film magnetic head according to an embodiment of the present invention, and FIG. 2 shows the MR element, the lower shield layer and the upper shield layer portion thereof. It is sectional drawing which shows the structure of. The thin film magnetic head of the present embodiment is a composite type thin film magnetic head including an MR element for reading and an inductive electromagnetic conversion element for writing.

In FIG. 1, 10 is a substrate which constitutes the main part of the slider, 11 is a lower shield layer which is formed on the substrate 10 through a base film (not shown), and 12 is laminated on the lower shield layer 11. Lower shield gap layer, 1
Reference numeral 4 is an upper shield gap layer, 15 is a shield gap layer, 16 is an upper shield layer, 13 is a lower shield gap layer 12 and an upper shield gap layer 14, and an ABS 1 between the lower shield layer 11 and the upper shield layer 16.
MR element formed to extend along 0a, 17
Is a lower magnetic layer of the write head portion, 18 is an upper magnetic layer, 1
Reference numeral 9 is a coil conductive layer surrounded by an insulating layer 20 made of an organic resin, 21 is a gap layer, and 22 is a protective layer.

The tip portions of the lower magnetic layer 17 and the upper magnetic layer 18 form pole portions 17a and 18a which face each other with a gap layer 21 having a very small thickness therebetween.
Writing is performed at 7a and 18a. On the opposite sides of the pole portions 17a and 18a of the lower magnetic layer 17 and the upper magnetic layer 18 constituting the yoke portion are back gap portions, which are coupled to each other so as to complete a magnetic circuit.
The coil conductive layer 19 is formed on the insulating layer 20 so as to spiral around the coupling portion of the yoke portion. The upper shield layer 16 may be configured so as to also serve as the lower magnetic layer of the write head section.

As shown in FIG. 2, in this embodiment, the MR element 13 is provided between the lower shield layer 11 and the upper shield layer 16 via the lower shield gap layer 12 and the upper shield gap layer 14. ing.

Lower shield layer 11 and upper shield layer 1
6, the magnetic capacities MV _L and MV _U are both 8.8E-15 Wbm or more, and the lower shield layer 1
1 and the ratio of the magnetic capacitance difference between the upper shield layer 16 and the magnetic capacitance of the upper shield layer 16 (MV _L −MV _U ) /
MV _U is 33% or less.

The heights H _L and H _U from the ABS of the lower shield layer 11 and the upper shield layer 16 are 5 respectively.
And at 0μm or more, and the height ratio _{(H L -H U) / H} U with respect to the height of the upper shield layer 16 of the difference from the ABS of the lower shield layer 11 and the upper shield layer 16 is 33% or less.

Further, the heights H _L and H _U from the ABS of the lower shield layer 11 and the upper shield layer 16 are 50 μm or more, and the surface areas S _L and S _U of the ABS side are 160 μm ² or more. .

As a result, concentration of the magnetic field on the MR element and its bias magnetic field control film is avoided, and the effective magnetic field applied to these MR element and bias magnetic field control film is reduced. As a result, even if an external uniform magnetic field for static characteristic measurement is applied, the reproduction magnetic characteristic of the MR sensor is not deteriorated, and the correlation between the static characteristic and the dynamic characteristic becomes very good.

[0027]

EXAMPLE 50 samples were prepared for each of a plurality of types of MR sensors having a substantially rectangular lower shield layer and an upper shield layer having different dimensions, and the correlation between the magnetic field resistance characteristics and the dynamic characteristics and static characteristics was obtained. And were measured respectively. The results are shown in Tables 1 and 2 and FIGS. 4 to 8.

[0028]

[Table 1]

[0029]

[Table 2]

However, in each type of sample, the thickness
(T_L, T_U), Width (W_L, W_U) And height (H_L, H
_U) And the surface area on the ABS side (S_L= T_L× W_L, S
_U= T _U× W_U) Is represented as in FIG.

The magnetic capacitance ratio means the lower shield layer and the upper shield layer.
Difference MV of the magnetic capacity of the shield layer _L-MV_UThe upper part of
Magnetic capacity MV of shield layer_URatio to (MV_L-MV
_U) / MV_UIs shown. Lower shield layer and upper shield
Magnetic capacity MV of shield layer_LAnd MV_UThe bottom seal
Area of the shield layer and the upper shield layer (S_L, S_U) × height
(H_L, H_U) × saturation magnetic flux density (Bs),
It is assumed that the shield layer and the upper shield layer are NiFe.
And its saturation magnetic flux density Bs is Bs = 1.1T (Tesla,
Wb / m^Two). Lower shield layer and upper shield
The layers are, of course, other than NiFe, for example CoFe, C
Various magnetic materials such as oFeNi, FeN, sendust
Can be formed.

The height ratio means the height H of the upper shield layer of the height difference H _L -H _U between the lower shield layer and the upper shield layer.
It indicates a ratio _{(H L -H U) / H} U for _U.

The rate of change occurrence is the rate at which the ρ-H loop shape, which is the magnetic characteristic of the MR sensor, changes when a relatively high magnetic field is applied to the MR sensor. Represents a characteristic. The actual measurement of the loop shape change occurrence rate is performed by a pseudo static characteristic tester (Quasi).
Static Tester, QST). First, an alternating magnetic field (+/− 50 Oe) perpendicular to the ABS was applied to each type of sample to measure MR output to obtain a ρ-H loop (initial measurement). Next, an alternating magnetic field much higher than this (+/- 300 Oe)
Applied in the same direction, the alternating magnetic field (+/- in the same direction)
The MR output was measured by applying 50 Oe) to obtain a ρ-H loop (measurement after application of a high magnetic field). The ρ-H loop shape obtained by the initial measurement thus obtained was compared with the ρ-H loop shape obtained by the measurement after applying the high magnetic field, and the change ratio of the loop shape was obtained. 9A and 9B show (A) a ρ-H loop shape measured by initial measurement and (B) a ρ-H loop shape measured by applying a high magnetic field for a sample having a good magnetic field resistance characteristic. For a defective sample, (A) ρ-H loop shape by initial measurement,
(B) shows a ρ-H loop shape measured after application of a high magnetic field. In FIG. 9B, the loop shape has not changed, but in FIG. 10B, Barkhausen noise has occurred and the loop shape has changed.

Correlation coefficient is determined by QST by alternating magnetic field (+
/ -150 Oe) is applied to measure the MR output with static characteristics, and the MR output with dynamic characteristics is measured with a dynamic performance (DP) tester (read / write tester), and the correlation between the two is quantified to obtain a correlation coefficient. I asked.

As can be seen from Table 1 and FIG. 4 (A), the magnetic capacity ratio (MV _L −MV _U ) / MV _U changes from a negative value from type 1 (T ₁ ) to type 4 (T ₄ ). The rate of occurrence of loop shape change decreases as it approaches zero. In the case of Type 1 (T ₁ ) and Type 2 (T ₂ ), the magnetic capacity of the lower shield layer is smaller than the magnetic capacity of the upper shield layer, and when the lower shield layer is saturated first, the magnetic field causes the lower shield layer to Through it to the upper shield layer, which has a larger magnetic capacitance and is not yet saturated. At this time, since a non-uniform magnetic field is applied to the MR element from the lower shield layer toward the upper shield layer, the magnetic characteristics of the MR element change and the loop shape change occurrence rate increases. On the other hand, in Type 3 (T ₃ ) to Type 5 (T ₅ ), the magnetic capacitance of the lower shield layer is Type 1 (T ₁ ) and Type 2 (T ₁ ).
Since it is larger than (T ₂ ), and the difference in magnetic capacity is small, a non-uniform magnetic field in the vertical direction is M
The possibility of being applied to the R element is low, and the rate of occurrence of loop shape change is good.

In addition, type 4 (T_Four) To Type 6 (T
₆) The magnetic capacity ratio increases from zero to a positive value
If the rate of occurrence of loop shape change remains good,
It Type 6 (T₆) Has a large magnetic capacity ratio
Has a magnetic capacity of type 3 (T _Three) ~ Type 5 (T₅)
Good external magnetic field resistance has been obtained because it is larger.
It is considered to be one.

On the other hand, comparing type 4 (T ₄ ) and type 7 (T ₇ ) in which the magnetic capacity ratios are both 0%,
The type 4 (T ₄ ) has a good loop shape change occurrence rate, whereas the type 7 (T ₇ ) has a poor loop shape change occurrence rate. This is because in Type 7 (T ₇ ), the magnetic capacity of the lower shield layer and the upper shield layer is 5.3E−.
It is considered that this is because a small magnetic field of 15 Wbm causes a large magnetic field to be applied to the MR element.

As can be seen from Table 2 and FIG. 5A, type 8 (T ₈ ) to type 3 (T ₃ ) and type 11
As the magnetic capacity MV _L of the lower shield layer increases to (T ₁₁ ), the loop shape change occurrence rate decreases. That is, type 3 _(T 3) ~ type 11 _{(T 11)} in the loop shape change incidence magnetically capacity MV _L is 8.8E-15Wbm or has a good 10% or less.

As can be seen from Table 1 and FIG. 4 (B), the magnetic capacity ratio (MV _L −MV _U ) / MV _U changes from a negative value from type 1 (T ₁ ) to type 4 (T ₄ ). The correlation coefficient approaches 1 as it approaches zero and becomes better, and further,
When the magnetic capacity ratio increases from zero to a positive value from type 4 (T ₄ ) to type 6 (T ₆ ), the correlation coefficient deteriorates. Type 1 (T ₁ ) and Type 2 (T ₂ )
In the case of, the non-uniform magnetic field is applied to the MR element from the lower shield layer to the upper shield layer as described above, and as a result, the effective magnetic field sensed by the MR element is different for each sample. It is considered that the correlation with the dynamic characteristics deteriorates. On the other hand, in the types 3 (T ₃ ) to 5 (T ₅ ), it is unlikely that the non-uniform magnetic field in the vertical direction is applied to the MR element as described above, and thus good correlation can be obtained. Becomes

The type 6 (T ₆ ) has a large difference in magnetic capacitance, and the higher the magnetic field, the more easily the magnetic field leaks from the upper shield layer to the lower shield layer. At this time, the magnetic charge is charged up in the step portion of the upper shield layer near the MR element, and a non-linear loop occurs in the magnetization characteristic of the MR element due to the magnetic field in the direction opposite to the externally applied magnetic field generated by the magnetic charge. Since this non-linear loop is different from each other due to variations in the shield shape of the sample,
It is considered that the type 6 (T ₆ ) deteriorates the correlation with the dynamic characteristics.

On the other hand, type 4 (T ₄ ) and type 7 (T
Comparing ₇ ), the magnetic capacity ratio is = 0% in both cases.
However, the correlation coefficient of type 4 (T ₄ ) is good, whereas the correlation coefficient of type 7 (T ₇ ) is poor. It is considered that this is because the magnetic capacities of the lower shield layer and the upper shield layer are as small as 5.3E-15 Wbm, and a large magnetic field is applied to the MR element.

As can be seen from Table 2 and FIG. 5B, type 8 (T ₈ ) to type 3 (T ₃ ) and type 11
As the magnetic capacity MV _L of the lower shield layer increases to (T ₁₁ ), the correlation coefficient approaches 1 and becomes good. That is, type 3 _(T 3) ~ type 11 _{(T 11)} The correlation coefficient magnetically capacity MV _L is 8.8E-15Wbm or becomes 0.8 or more and good.

Therefore, the magnetic capacities MV _L and MV _{U of} the lower shield layer and the upper shield layer are both 8.8E-.
If the ratio (MV _L −MV _U ) / MV _U is 15 Wbm or more and the ratio of the magnetic capacity difference between the lower shield layer and the upper shield layer to the magnetic capacity of the upper shield layer is 33% or less, the loop shape change occurrence rate is It can be seen that both and the correlation coefficient are good.

As can be seen from Table 1 and FIG. 6A, as the height H _L of the lower shield layer increases from type 1 (T ₁ ) to type 6 (T ₆ ), the loop shape change occurrence rate decreases. Has become. That is, the type 3 (T ₃ ) to type 6 (T ₆ ) having the height H _L of 50 μm or more have a good loop shape change occurrence rate.

As can be seen from Table 1 and FIG. 6B, the correlation coefficient becomes 1 as the height H _L of the lower shield layer increases from type 1 (T ₁ ) to type 4 (T ₄ ). As the height increases from Type 4 (T ₄ ) to Type 6 (T ₆ ), the correlation coefficient deteriorates. That is, both types 3 (T ₃ ) to 5 (T ₃ ) have a height H _L of 50 μm or more.
_{In 5} ), good correlation was obtained, but type 6
The correlation is worse at (T ₆ ).

As can be seen from Table 1 and FIG.
Ip 1 (T₁) To Type 4 (T_Four) To height ratio (H_L
-H_U) / H_UIs a negative value as it approaches zero.
The rate of shape change is small, and
4 (T_Four) To Type 6 (T ₆) To this height ratio is zero
From 0 to a positive value, the loop shape change occurrence rate is good.
It is maintained as it is. That is, the height ratio is 33% or less
Type 3 (T_Three) ~ Type 5 (T₅), Loop shape
The rate of change occurrence is good. However, the height ratio is 0%
Even type 7 (T₇) Is the rate of change in loop shape
Is getting worse.

As can be seen from Table 1 and FIG. 7B, the height ratio ( _HL ) changes from Type 1 (T ₁ ) to Type 4 (T ₄ ).
As −H _U ) / H _U approaches a negative value to zero, the correlation coefficient approaches 1 and becomes good, and further, the type 4 (T
₄ ) to type 6 (T ₆ ) the correlation coefficient worsens when this height ratio increases from zero to a positive value. That is, good correlations are obtained in Type 3 (T ₃ ) to Type 5 (T ₅ ).

Therefore, from the results of Table 1, FIG. 6 and FIG.
Heights of lower shield layer and upper shield layer H _L and H _U
There is any even 50μm or more, and if the height ratio of the lower shield layer and the upper shield layer _{(H L -H U) / H} U is 33% or less, the loop shape change incidence and correlation coefficient are both good I see.

As can be seen from Table 2 and FIG. 8A, type 8 (T ₈ ), type 3 (T ₃ ), type 9 (T ₉ ).
As the area S _L of the ABS side surface of the lower shield layer increases to type 11 (T ₁₁ ), the loop shape change occurrence rate decreases. That is, the area S _L is 160 μm ²
In the above-described type 3 (T ₃ ), type 10 (T ₁₀ ) and type 11 (T ₁₁ ), the loop shape change occurrence rate is good.

As can be seen from Table 2 and FIG.
Type 8 (T₈), Type 3 (T_Three), Type 9
(T₉) ~ Type 11 (T₁₁) To the bottom shield layer
Area S of the ABS side surface_LAs the correlation coefficient increases
It approaches 1 and is good. That is, the area S_LIs 16
0 μm^TwoType 3 (T_Three), Type 10 (T
₁₀) And type 11 (T₁₁) Gives a good correlation
Has been.

This is because the smaller the area of the surface of the shield layer on the ABS side is, the more the magnetic field is concentrated, so the effective magnetic field received by the MR element and its magnetization bias layer becomes stronger, and the loop shape change occurrence rate and the dynamic characteristics are increased. It is considered that the correlation of is worsening.

[0052] Thus, Table 1, Table 2, the results of FIGS. 6 and 8, both the height H _L and H _U of the lower shield layer and the upper shield layer is at 50μm or more, the lower shield layer and the upper shield layer ABS surface area S _L and S _U
It can be seen that when both are 160 μm ² or more, both the loop shape change occurrence rate and the correlation coefficient are good.

The embodiments and examples described above are merely illustrative of the present invention and are not limitative, and the present invention can be implemented in various other modified modes and modified modes. . Therefore, the scope of the present invention is defined only by the claims and their equivalents.

[0054]

As described in detail above, as in the present invention, when the magnetic capacity of each of the lower shield layer and the upper shield layer is 8.8E-15 Wbm or more, the magnetic field resistance is improved and MR even if an external uniform magnetic field for characteristic measurement is applied
The reproducing magnetic characteristics of the sensor will not deteriorate. Moreover, by setting the ratio of the magnetic capacitance difference between the lower shield layer and the upper shield layer to the magnetic capacitance of the upper shield layer to 33% or less, the correlation between the static characteristic and the dynamic characteristic becomes very good.

The height of each of the lower shield layer and the upper shield layer from the ABS is 50 μm or more, and the ratio of the height difference from the ABS of the lower shield layer and the upper shield layer to the height of the upper shield layer is 33. % Or less, M
Concentration of the magnetic field on the R element and its bias magnetic field control film is avoided, the effective magnetic field applied to these MR element and bias magnetic field control film is reduced, and an external uniform magnetic field for static characteristic measurement is applied. Also, the reproduction magnetic characteristic of the MR sensor is not deteriorated, and the correlation between the static characteristic and the dynamic characteristic becomes very good.

If the height of each of the lower shield layer and the upper shield layer from the ABS is 50 μm or more and the area of the ABS side surface of each of the lower shield layer and the upper shield layer is 160 μm ² or more, the MR element is formed. The concentration of the magnetic field on the bias magnetic field control film is avoided, and the effective magnetic field applied to the MR element and the bias magnetic field control film is reduced. As a result, even if an external uniform magnetic field for static characteristic measurement is applied, the reproduction magnetic characteristic of the MR sensor is not deteriorated, and the correlation between the static characteristic and the dynamic characteristic becomes very good.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a configuration of a main part of a thin film magnetic head according to an embodiment of the present invention.

FIG. 2 is a sectional view schematically showing the configurations of the MR element, the lower shield layer and the upper shield layer portion of the embodiment of FIG.

FIG. 3 Thickness, width, height and A for each type of sample
It is a figure explaining the area of the surface by the side of BS.

FIG. 4 is a diagram showing a relationship between a magnetic capacity ratio of a lower shield layer and an upper shield layer, a loop shape change occurrence rate, and a correlation coefficient.

FIG. 5 is a diagram showing a relationship between a magnetic capacity of a lower shield layer, a loop shape change occurrence rate, and a correlation coefficient.

FIG. 6 is a diagram showing the relationship between the height of the lower shield layer, the loop shape change occurrence rate, and the correlation coefficient.

FIG. 7 is a diagram showing a relationship between a height ratio of a lower shield layer and an upper shield layer, a loop shape change occurrence rate, and a correlation coefficient.

FIG. 8 is a diagram showing the relationship between the area of the ABS side surface of the lower shield layer, the loop shape change occurrence rate, and the correlation coefficient.

FIG. 9 is a diagram showing a ρ-H loop shape obtained by initial measurement and a ρ-H loop shape obtained by measurement after applying a high magnetic field for a sample having good magnetic field resistance characteristics.

FIG. 10 is a diagram showing a ρ-H loop shape by an initial measurement and a ρ-H loop shape by a measurement after applying a high magnetic field for a sample having a poor magnetic field resistance characteristic.

[Explanation of symbols]

10 substrates 11 Lower shield layer 12 Lower shield gap layer 13 MR element 14 Upper shield gap layer 15 Shield gap layer 16 Upper shield layer 17 Lower magnetic layer 18 Upper magnetic layer 19 Coil conductive layer 20 insulating layer 21 Gap layer 22 Protective layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koichi Terunuma             1-13-1, Nihonbashi, Chuo-ku, Tokyo Tea             DC Inc. F term (reference) 2G017 AC01 AD55 AD63 AD65                 5D034 BA02 BB08

Claims (6)

[Claims] 1. A lower shield layer, an upper shield layer,
A magnetoresistive effect element provided between the lower shield layer and the upper shield layer, and the magnetic capacity of each of the lower shield layer and the upper shield layer is 8.8E-1.
A magnetoresistive effect sensor, characterized in that the ratio is 5 Wbm or more and the ratio of the magnetic capacitance difference between the lower shield layer and the upper shield layer to the magnetic capacitance of the upper shield layer is 33% or less. 2. The sensor according to claim 1, wherein the magnetic capacities of the lower shield layer and the upper shield layer are substantially equal to each other. 3. A lower shield layer, an upper shield layer,
A magnetoresistive effect element provided between the lower shield layer and the upper shield layer, and the height from the air bearing surface of each of the lower shield layer and the upper shield layer is 50 μm.
A magnetoresistive effect sensor, characterized in that the ratio of the height difference of the lower shield layer and the upper shield layer from the air bearing surface to the height of the upper shield layer is 33% or less. 4. A lower shield layer, an upper shield layer,
A magnetoresistive effect element provided between the lower shield layer and the upper shield layer, and the height from the air bearing surface of each of the lower shield layer and the upper shield layer is 50 μm.
The magnetoresistive effect sensor is characterized in that the area of the air bearing surface side of each of the lower shield layer and the upper shield layer is 160 μm ² or more. 5. The sensor according to claim 3, wherein the heights of the lower shield layer and the upper shield layer are substantially equal to each other. 6. A thin-film magnetic head comprising the magnetoresistive effect sensor according to claim 1 as a reproducing head element.