JPH11242806A - Thin film magnetic head, magnetic disk device, grinding/ processing method and its measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve detective precision of a resistance value change by respectively connecting both ends of an MR element to two terminals, making a current flow through a set of terminals and measuring a voltage of another set of terminals. SOLUTION: For neglecting electrode resistance Rd, both ends of the MR element are connected respectively to two electrodes, that is, a voltage measuring electrodes 14 and a current electrodes 13. At this time, the current (i) is made to flow through the current electrodes 13 being outside electrodes, and the voltage V applied to the voltage measuring electrodes 14 being inside electrodes is measured. Since the electrode resistance Rd doesn't enter the relation V=i.Rm used here, the resistance value Rm of the MR element is measured directly. Where, the Rm is the resistance value of the MR element. Then, the MR element height is obtained from the resistance value Rm of this MR element, and the MR element height is measured precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head having an inductive magnetic transducer and a magnetoresistive element stacked on a substrate, and more particularly to a thin film magnetic head for accurately detecting the resistance of the magnetoresistive element. The present invention relates to a magnetic head structure, a magnetic disk device using the same, and a method of processing a thin-film magnetic head.

[0002]

2. Description of the Related Art In recent years, the size and capacity of magnetic disk drives have been reduced, and currently 3.5-inch and 2.5-
Small magnetic disk drives using inch-size disks have become mainstream. In such a small disk device, since the speed of the disk is low, a magnetic output head whose reproduction output depends on the disk speed has a problem that the reproduction output is reduced.

On the other hand, in a magnetoresistive head (hereinafter, referred to as an MR head) using a magnetoresistive effect element (hereinafter, referred to as an MR element) whose resistance value changes due to a change in a magnetic field, a reproduction output is a disk. Because it does not depend on speed,
High reproduction output can be obtained even in a small magnetic disk drive. In addition, the MR head is considered to be a magnetic head suitable for miniaturization and large capacity because it can obtain a higher reproduction output than a magnetic induction type magnetic head even for a narrower track due to higher density. Have been.

On the other hand, in the MR head, in order to detect a change in the resistance value of the MR element caused by a change in the magnetic field, the MR element is exposed on a surface of the magnetic head slider facing the disk (hereinafter referred to as a flying surface). The structure used has the highest regeneration efficiency. An MR in which the MR element is exposed on such an air bearing surface
In the head, a part of the MR element is processed (polished) when the air bearing surface is processed, and is exposed on the air bearing surface. The dimension in the direction perpendicular to the air bearing surface of the MR element is called an MR element height, and the height of the MR element is determined by controlling a processing amount in polishing.

In the MR head, the reproduction output varies depending on the height of the MR element. Therefore, when the height of the MR element varies, there arises a problem that the reproduction output varies. Therefore, in order to control the reproduction output fluctuation of the MR head, M
It is necessary to precisely process the height of the R element in the polishing step.

In the polishing process, in order to increase the processing accuracy of the MR element height, it is important to measure the MR element height with high accuracy. MR element height is 0.5 ~
Although the size is about 3 μm, it is difficult to optically directly measure the height of the MR element because an inductive head for writing data is formed on the MR element. As a method of optically measuring the MR element, a method of processing the MR element from the air bearing surface by FIB and measuring the MR element exposed on the processed cross section is disclosed in JP-A-63-34713 and JP-A-2-29913. As described in Japanese Patent Application Laid-Open Publication No. H10-157, a marker for measurement is formed separately from the MR element in the step of forming the element, and this marker is optically measured to obtain an MR.
There is a method of measuring the element height (the amount of processing at the time of polishing).

As a general method of measuring the height of an MR element other than the optical measurement, the resistance value of the MR element is measured.
There is a method of converting to the height of the MR element. In the case of measuring the resistance value, as described in JP-A-5-46945, a method of measuring the resistance value of an MR element and converting it into a height of the MR element is disclosed in JP-A-63-191570. As described in the official gazette, there is a method of calculating the height of the MR element by measuring the resistance value of a pattern for measurement in advance in an element forming process separately from the MR element.

[0008]

There are two ways to use the measured data when measuring the height of the MR element.

(1) When the measured data of the MR element height is used for controlling the polishing conditions (processing, stop, processing pressure, etc.) in the step of polishing the air bearing surface.

(2) A case where data of the height of the MR element is used to confirm that the height of the MR element is processed within a predetermined specification value at the time when the polishing of the air bearing surface is completed. (In this case, the quality of the magnetic head is determined.) Among the measurement methods described above, the method of processing the MR element from the air bearing surface with the FIB and measuring the MR element exposed on the processed cross section is as follows. There is a problem that the device does not function as a magnetic head because the device is broken and measured.

The measuring methods described in JP-A-63-34713 and JP-A-2-29913 do not measure an actual MR element. Therefore, even if the same mask is used and the same MR film is used. Even if it is formed, there is a problem that an error occurs at the time of making the mask, and when it is used for the purpose of (1), it is difficult to measure in-process during the polishing process. It is inefficient as a measuring method for increasing the accuracy of the height of the MR element in the polishing step.

In contrast to the above-mentioned optical MR element height measuring method, the method of measuring the resistance value and converting it to the MR element height has the following advantages.

(1) The measurement is simple. (2) The measurement can be performed in-process during polishing. For this reason, the method of measuring the resistance value is generally widely used. The method of measuring the resistance value and converting it to the MR element height includes a method of measuring the resistance value of the pattern for measurement and converting the resistance value to the MR element height, and a method of actually measuring the resistance of the MR element. There is a method of measuring the value and converting it to the MR element height. However, the former method has a problem that the error is large because the actual MR element is not measured. Therefore, as a method of measuring the MR element height, a method of measuring the actual resistance value of the MR element and converting the resistance value to the MR element height is a simple method with a small error.

However, the resistance of the MR element is measured and the MR
When converting to the element height, there are the following problems.

When measuring the resistance value of the MR element, the resistance value of the MR element itself and the resistance value of an electrode serving as a wiring between the MR element and the terminal are simultaneously measured. Since this electrode is also processed by polishing, the resistance value of the electrode changes with the polishing amount. Therefore, when obtaining the height of the MR element from the change in the resistance value of the MR element, the resistance value of the electrode causes an error.

Further, from the viewpoint of improving the recording density, the width (track width) of the MR element tends to be narrow. And
As the track width of the MR element decreases, the resistance value of the MR element decreases. On the other hand, since the resistance value of the electrode hardly changes, the ratio of the resistance value of the MR element to the measured resistance value decreases, and the ratio of the electrode resistance increases.
This causes a problem that the measurement accuracy of the resistance value of the MR element is reduced.

A first object of the present invention is to measure the resistance value of an MR element directly and measure the resistance value of the MR element when converting the resistance value of the MR element into an MR element height. It is an object of the present invention to provide a magnetic head structure that can be used and a polishing method for processing the height of the MR element of the magnetic head with high accuracy.

A second object of the present invention is to improve the detection accuracy of a change in resistance value when reading data written on a disk by a change in resistance value of an MR element in a magnetic disk device incorporating an MR head. To provide a structure of a magnetic head and a detection method.

[0019]

SUMMARY OF THE INVENTION The first object is to provide an MR.
This is achieved by connecting both ends of the device to two terminals, passing a current through one set of terminals, and measuring the voltage at the other set of terminals.

The second problem is that a magnetic head in which both ends of an MR element are connected to two terminals is mounted on a magnetic disk drive, a current flows through one set of terminals, and a second set of terminals is connected. Achieved by measuring the voltage.

[0021]

Embodiments of the present invention will be described below.

First, an outline of the magnetic disk drive will be described. FIGS. 2A and 2B are arrangement diagrams of a magnetic head and a disk. In a CSS (Contact Start Stop) type magnetic disk device, the magnetic head slider 3 is floated by a very small amount from the surface of the disk by utilizing dynamic pressure generated by rotation of a disk 19 serving as a magnetic recording medium.
Data is recorded and reproduced by a magnetic recording element formed at the end of the slider. At this time, the disk 19
The distance between the surface of the magnetic head 1 and the magnetic head 1 is called a flying height h, and the angle of the magnetic head 1 with respect to the disk 19 is called an elevation angle θ.

Recording and reproduction of a magnetic disk device using an MR head are performed as follows.

Recording is performed by magnetizing the disk surface with the coil 5 and the upper magnetic film 6.

The relative movement between the surface of the magnetic disk 19 and the magnetic head slide 3 causes the MR element 4
Changes the resistance value. By detecting the change in the resistance value of the MR element 4, the data written on the surface of the disk 19 is reproduced.

Next, the structure of a conventional MR head will be described. 3A and 3B are structural views of the MR head. The MR head has a plurality of magnetic heads formed by forming an inductive magnetic transducer and an MR element on the surface of a ceramic wafer 1 by a thin film process represented by sputtering, mask formation, etching, and the like, and cutting the same. It is processed into a row bar 2 with a series of sliders. Then, polishing (floating surface polishing) is performed in the state of the row bar, and the floating surface 1 is polished.
8 is processed into a predetermined shape and surface state. Then, the row bar 2 after polishing is cut again to bring the magnetic head slider 3 into a state. For this reason, the magnetic head slider 3
A magnetic recording element formed in the state of the wafer 1 is formed on the end surface of the substrate. Next, the structure of the element section will be described.

The inductive magnetic recording element comprises a coil 5 and an upper magnetic film 6. An end of the upper magnetic film 6 is exposed on the air bearing surface 18, and data is recorded by the exposed portion. The MR element 4 is arranged below the upper magnetic film 6, and electrodes 7 are connected to both ends of the MR element 4. Also,
In order to reduce noise during data reproduction of the MR element, the MR element 4 is sandwiched between the upper shield film 8 and the lower shield film 9.

In the case of the majority of MR heads, since the MR element 4 has a structure exposed on the air bearing surface 18 like the upper magnetic film 6, the MR element 4 is polished on the air bearing surface 18. At that time, a part thereof is removed. Therefore, MR
The height of the MR element, which is the height in the direction perpendicular to the air bearing surface of the element 4, is determined by this polishing.

Since the height of the MR element greatly affects the reproduction output when reproducing data, the processing tolerance during polishing is very narrow. Therefore, it is necessary to check whether the height of the MR element is within a predetermined dimension after the polishing process in order to ensure the reliability of the magnetic disk drive.

Since the measurement of the MR element height is simple and highly reliable, a method of measuring the resistance value of the MR element and converting this resistance value to the MR element height is generally used. Is being done.

Next, a method for controlling and polishing the height of the MR element will be described. FIGS. 4A and 4B are structural views (row bar state) of the current magnetic head slider. One magnetic head slider has an inductive magnetic transducing element and an MR element, and a terminal 10 for an MR element and a terminal 11 for an inductive magnetic transducing element for connecting each to a signal processing circuit of a magnetic disk drive. Are formed. A cut portion is provided between the magnetic head slider and the magnetic head slider. The cut portion is provided with a resistance detection pattern 12 for detecting the height of the MR element and a terminal 13 for the resistance detection pattern during the air bearing surface polishing process. Is formed.

In controlling the height of the MR element in polishing, the height of the MR element is converted by detecting a change in resistance value when a part of the resistance detection pattern 12 is removed by polishing. The amount of polishing is controlled. Generally, since the resistance detection pattern 11 is formed of the same MR film in the same step as the MR element, the amount of positional deviation from the actual MR element can be suppressed to a small value. Changes in film thickness and specific resistance can be canceled. Therefore, a measurement error between the MR element height converted by the resistance detection pattern 13 and the actual MR element height can be reduced.

Next, a description will be given of a structure and a measuring method of the MR element for improving the measuring accuracy of the MR element height.

Here, the structure of the MR head and a method for measuring the height of the MR element developed for the purpose of improving the accuracy of measuring the height of the MR element will be described below. First, a conventional method for detecting the height of the MR element of a magnetic head slider will be described.

FIGS. 4A and 4B are conceptual diagrams of an MR element of a conventional magnetic head slider. The structure is M
An electrode 7 is connected to both ends of the R element 4, and the other end of the electrode 7 is connected to a terminal 10 for connecting to a signal processing circuit of a magnetic disk drive. When measuring, MR
A current i is applied to the element 4 and the electrode 7, and the voltage V between the terminals 10 at that time is measured. The resistance value of the electrode 7 is Rd,
Assuming that the resistance value of the MR element 4 is Rm, the voltage V is expressed by the following [Equation 1].

[0036]

V = i (2Rd + Rm) Further, the conversion formula of the MR element height is expressed by the following [Equation 2].

[0037]

## EQU2 ## MR element height = .rho.Tw / t.Rm .rho .: specific resistance of film Tw: track width t: film thickness Rm: resistance From these [Equation 1] and [Equation 2], the MR element height is determined. Although calculation is performed, Rm cannot be measured directly with the conventional MR head, and therefore the following error factors are included.

(1) Since the measured resistance value includes the electrode resistance Rd, the measurement accuracy of the resistance value is Rm / (2Rd + R
m), and the measurement accuracy decreases.

(2) From the measured resistance value, the electrode resistance Rd
And the MR element resistance Rm cannot be separated, and as a practical method, a pattern capable of measuring only the resistance value of Rd is separately formed, and Rd ′ is obtained in advance by measuring the resistance value of the pattern. Then, Rm is calculated by substituting Rd ′ into [Equation 1]. In this method, the variation in the electrode resistance Rd becomes an error as it is. Further, since the tip of the electrode 7 is removed at the time of polishing the air bearing surface, Rd is a function of the polishing amount. Therefore, since the actual Rd changes depending on the polishing amount, an error from Rd 'tends to occur.

(3) The track width, which is the width of the MR element, is
The width is becoming narrower as the recording density is improved. Accordingly, the resistance value of the MR element resistor Rm tends to decrease. However, since the electrode resistance Rd hardly changes, the measurement accuracy of Rm described in (1) tends to decrease.

Next, the MR of the present invention developed to solve the problem of measuring the height of the MR element of the conventional MR head.
The head structure and the measurement method will be described below.

FIGS. 5A and 5B are structural views of a magnetic head slider (MR head) of the present invention. The decrease in the measurement accuracy of the MR element height of the conventional magnetic head is caused by the electrode resistance Rd
Was the cause. Therefore, in the present invention, in order to make the electrode resistance Rd negligible, as shown in FIG.
It was configured to be connected to the current electrode 13). At this time, when the current i flows through the current electrode 13 as the outer electrode and the voltage V applied to the voltage measurement electrode 14 as the inner electrode is measured, the voltage V is obtained by the following [Equation 3].

[0043]

V = i · Rm In [Equation 3], since the electrode Rd does not enter, the MR
It can be seen that direct measurement of the resistance value Rm of the element becomes possible.

Then, by substituting Rm into [Equation 2], the height of the MR element can be obtained from the value of Rm. This makes it possible to measure the height of the MR element with high accuracy.

In the above-described MR head, since the two ends of the MR element are connected to two terminals, six terminals are required for one magnetic head slider. In the developed magnetic head, as shown in FIG. 5, a terminal 16 connected to the voltage measuring electrode 14 is located at a position closest to the MR element, a terminal 15 is connected to the current electrode 13 next to the terminal 16, and an induction is provided on the outermost side. The terminal 11 connected to the type magnetic transducer was arranged. However, if six terminals are provided in one magnetic head slider, most of the space is used for the terminals and the coil 5.

To cope with this problem, an MR head in which the arrangement of terminals is taken into consideration has also been developed. FIG. 6 (a),
As shown in (b), terminal 1 connected to current electrode 13
By forming 5 in the cut portion, the number of terminals to be put into one magnetic head slider can be reduced to four as in the conventional MR head. However, in this case, since there is no space for forming the resistance detection pattern 12 and the terminal 13 in the cut portion, the height of the MR element is measured in-process at the time of polishing the air bearing surface, thereby controlling the height of the MR element. It is not possible. In this case, the resistance value of the MR element is measured, and the height of the MR element is controlled based on the height of the MR element obtained thereby.

Next, a description will be given of the high-precision MR element height control polishing by in-process MR element height detection.

Here, a description will be given of the control polishing of the MR element height using the above-described structure and measuring method of the MR head. First, a description will be given of the control polishing of the height of the MR element in the conventional MR head.

FIG. 7 shows a processing process of the MR head.
As described above, in the processing of the MR head, after the elements are formed on the surface of the wafer 1, the processing is performed into the state of the row bar 2 by cutting. By polishing the air bearing surface in a row bar state, the surface roughness of the air bearing surface is improved, and by polishing a part of the MR element and the upper magnetic film, they are exposed to the air bearing surface, and the MR element is exposed. The height is reduced to a predetermined size.

In this polishing of the air bearing surface, the row bar is bonded to a dedicated jig, so that the row bar has a secondary bending component and a secondary or higher bending component (undulation component) due to the shrinkage force of the wax at the time of bonding. Occurs. If the air bearing surface is polished in a state where the secondary bends and undulations are mixed, the height of the processed MR element in the same row bar varies.

In order to prevent this, a method is used in which a secondary bending component of the row bar after bonding is corrected in advance before polishing by bending the bonding surface using a jig having a structure capable of bending the bonding surface. .

In the polishing of the floating surface, the resistance value of the resistance detection pattern formed at the cut portion is measured in-process.
By converting this value to the MR element height, the M
The distribution of the height of the R element is grasped, and if the distribution of the height of the MR element is inclined, the inclination of the height of the MR element is corrected by controlling the balance of loads applied to both ends of the jig. At the same time, when the distribution of the detected MR element height reaches a predetermined dimension, polishing is stopped to process the MR element height to a predetermined dimension.

After the completion of the polishing, in order to confirm whether the MR element has been processed to a predetermined size, the resistance values of all the MR elements are measured and converted into MR element heights. It is carried out. Thereafter, by cutting the row bar state, the magnetic head slider is divided into sliders, thereby completing the magnetic head slider. Then, the non-defective product is put into an assembling process and incorporated into a magnetic disk device.

The above is the general processing steps of the conventional MR head. However, the following problems occur with respect to the height of the MR element.

(1) In the flying surface polishing, the height of the MR element is calculated from the resistance value of the resistance detection pattern. Therefore, the height of the MR element calculated from the resistance detection pattern and the height of the MR element calculated from the resistance value of the MR element are calculated. A gap of about 0.1 to 0.3 μm may occur between them.

The cause is considered as follows. 1
One is that the resistance detection pattern is formed by the same mask when the MR element is formed, but the MR element and the resistance detection pattern are misaligned by the accuracy of the mask, and this is an error caused by the misalignment. The other is an error resulting from the fact that each is affected by the electrode resistance and the ratio of the electrode resistance to the MR element is also different.

(2) Regarding the measurement of the height of the MR element after the air bearing surface lap, the same MR element as the FIB (Focused Ion Beam), which is the same as the MR element height calculated from the resistance value of the MR element due to the above-described influence of the electrode resistance, is used. ) Between the actual MR element height measured and optically measured from the cross section
An error of about 0.2 μm may occur.

On the other hand, in the present invention, the MR head was processed by a processing process described below.

FIG. 8 shows an MR head processing process of the present invention. In the element forming step, the electrodes and terminals of the MR element part are formed in the structure shown in FIG. In the cut portion, a resistance detection pattern and its terminal are formed. Next, the wafer after the element formation is cut to form a row bar. And
The cut row bar is adhered to a jig. At this time, a jig for bending and deforming the jig bonding surface in a second or higher order mode is used.

The processing machine used for air bearing surface polishing has at least one load control device for applying a load for deforming the bonding surface of the jig, and controls the inclination of the jig at the time of polishing. There are two load control devices for applying a load, and these load control devices are controlled by a computer. Further, after the polishing platen is rotated, the supply amount of the processing liquid is also controlled by the computer. The air bearing surface polishing is performed by the following process.

(1) Control Step 1 During the polishing process, the resistance value of the resistance detection pattern is measured in-process and is converted into the MR element height. Then, the distribution of the height of the MR element in the row bar is calculated by a computer. Then, the polishing efficiency is controlled by controlling the polishing load, the number of rotations of the platen, and the supply amount of the processing liquid from the calculated distribution of the MR element height. At this time, the inclination of the distribution of the height of the MR element is corrected by controlling the balance of the polishing load applied to both ends of the jig, and the height of the MR element is controlled by controlling the load applied to the bonding surface of the jig. Are corrected for the secondary bending component and the undulating component in the distribution.

With respect to the gradient of the MR element height distribution, the secondary bending component, and the undulation component, the value of the applied load is changed each time based on the distribution data of the MR element height at a predetermined sampling time. The gradient of the MR element height distribution, the secondary bending component, and the undulating component are reduced. And
When the distribution of the height of the MR element reaches a predetermined size, the process proceeds to the control step 2.

(2) Control Step 2 In this step, the current i is passed through the current electrode 13 to the resistance value of three or more MR elements in the row bar, and the voltage measurement electrode 1
4 is measured to obtain the resistance Rm of the MR element.
Is measured directly in-process during polishing. And
By substituting this value into [Equation 2], the value is converted into the MR element height, and the distribution of the MR element height in the row bar is calculated. Then, based on this data, the polishing efficiency is controlled by controlling the polishing load and the supply amount of the working fluid after the rotation of the platen, and the polishing load applied to both ends of the jig is controlled in the same manner as in the control step 1. , The inclination of the distribution of the height of the MR element is corrected, and the load applied to the bonding surface of the jig is controlled to correct the secondary bending component and the undulation component in the distribution of the height of the MR element. Then, when the polishing process proceeds and the height of the MR element reaches a predetermined size, the process is stopped.

By performing the polishing described above,
The deviation between the MR element height calculated from the resistance detection pattern and the MR element height calculated from the resistance value of the MR element, which is a problem in the conventional MR head processing process, can be reduced. Thereby, the processing accuracy of the MR element height in the processing of the MR head can be improved, so that the processing yield due to the MR element height can be improved.

In the present invention, the current i is passed through the current electrode 13 and the voltage of the voltage measurement electrode 14 is measured also in the measurement of the MR element height after the air bearing surface is polished.
By directly measuring the resistance value Rm of the MR element and converting this to the MR element height, M converted from the resistance value of the MR element is obtained.
It is possible to reduce an error between the R element height and the actual MR element height obtained by measuring the MR element height from the cross section of the same MR element by FIB processing. As a result, a magnetic head slider having an MR element height of a predetermined size can be sent to the assembling process, and the reproduction output of the magnetic disk device can be stabilized.

In the case where the electrode 15 is formed in the cut portion shown in FIG. 6, it is difficult to form a resistance detection pattern in terms of space. Therefore, as shown in FIG. The height of the MR element is controlled only by the control step 2 for measurement.

Next, a method for detecting a change in the resistance value of the MR element in the magnetic disk drive will be described.

Here, a method for detecting a change in the resistance value of the MR element in the magnetic disk drive of the present invention will be described. First, the structure of the magnetic disk drive of the present invention will be described. 1A and 1B are external views of a magnetic disk drive on which an MR head is mounted. In the CSS type magnetic disk device, the surface of a disk 19 as a recording medium and the floating surface 18 of the magnetic head slider 3 are arranged to be in contact with each other. The magnetic head 3 is fixed near the tip of the leaf spring 20, and is moved in the radial direction of the disk 19 by the actuator 21 at the other end of the leaf spring 20.

The MR head to be mounted has the MR head structure shown in FIG. 5. When reproducing data written on the disk 19, a change in the resistance value of the MR element is detected as described below. 19 can be reproduced.

The actual reproduction of data is performed as follows. A current i is passed through the current electrode 13 with respect to two electrodes (a voltage measurement electrode 14 and a current electrode 13) at both ends of the MR element, and the voltage measurement electrode 14 as an inner electrode.
Is measured. And the voltage V at this time
Is represented by [Equation 3]. When the disk 19 and the magnetic head slider 3 slide, the resistance value Rm of the MR element changes depending on the polarity written on the disk 19.

Since the voltage V changes due to the change in the resistance value, the data written on the disk can be converted into a digital signal by performing signal processing on the voltage V. Further, in [Equation 3], since the electrode Rd does not enter,
Direct measurement of the resistance value Rm of the MR element becomes possible. Therefore, it is possible to improve the accuracy of detecting the change in the resistance value of the MR element when reading data. As a result, the prevention of data reading errors is suppressed, so that the reliability of the magnetic disk device can be improved.

Here, the MR head using the MR element has been described.
A similar measurement is possible for a (Giant MR) head.

[0073]

(1) In the present invention, since the influence of the electrode resistance is eliminated and the resistance value of the MR element can be directly measured, the measurement accuracy of the MR element height is improved. As a result, only the magnetic head slider having the MR element having a predetermined height can be sent to the assembling process. Therefore, the reliability of the magnetic disk device can be improved by simplifying the inspection process in the assembly process and stabilizing the reproduction output in the MR head.

(2) The height of the MR element is measured in-process in the air bearing surface polishing step, and the polishing conditions are controlled based on the measured height of the MR element. Accuracy can be improved. This gives M
The yield due to the MR head in R head production can be improved.

(3) When reading the data written on the disk by the change in the resistance of the MR element, the measurement accuracy of the change in the resistance of the MR element is improved by using the same measurement method as that for measuring the height of the MR element. can do. As a result, the prevention of data reading errors is suppressed, so that the reliability of the magnetic disk device can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a magnetic disk drive according to an embodiment of the present invention.

FIG. 2 is a structural diagram illustrating the structure of a magnetic head (MR head).

FIG. 3 is a perspective view illustrating the structure of the conventional MR head of FIG. 1;

FIG. 4 is a structural diagram illustrating the structure of an MR head according to an embodiment of the present invention. (When using a resistance measurement pattern together)

FIG. 5 is a structural diagram illustrating the structure of an MR head according to an embodiment of the present invention. (When not using the resistance measurement pattern together)

FIG. 6 is an arrangement diagram showing an arrangement of a magnetic head and a disk.

FIG. 7 is a flowchart showing a processing process of a conventional MR head.

FIG. 8 is a flowchart showing a processing process of the MR head of the present invention.

FIG. 9 is a flowchart showing a processing process of the MR head in the case where a terminal for connecting a current electrode is formed in a cut portion.

[Explanation of symbols]

1 ... Wafer, 2 ... Rover, 3 ...
Magnetic head slider, 4 MR element (magnetoresistive element), 5 coil, 6 upper magnetic film, 7 electrode, 8 upper shield film, 9 lower shield film, 10 M
R element connection terminal, 11: terminal for inductive magnetic conversion element connection, 12: resistance measurement pattern, 13: current electrode (electrode dedicated to flowing current), 14: voltage measurement electrode (electrode dedicated to voltage measurement) ), 15 ... Terminal for connection to current electrode, 1
6 ... Terminal for connection with voltage measurement electrode, 17 ... Terminal for resistance measurement pattern, 18 ... Floating surface, 19 ... Disk,
20: leaf spring, 21: actuator,
22 ... substrate material.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Chihiro Isono 2880 Kozu, Kodahara, Kanagawa Prefecture, Hitachi, Ltd. Storage System Division (72) Inventor Koji Tanaka 2880 Kozu, Kozu, Odawara, Kanagawa Hitachi Storage System, Ltd. Within the business division

Claims (7)

[Claims] 1. A thin film magnetic head comprising an inductive magnetic transducer and a magnetoresistive element laminated on a substrate, wherein both ends of the magnetoresistive element are connected to two terminals, respectively. 2. A magnetic disk comprising: a disk as a recording medium; a thin-film magnetic head having both ends of a magnetoresistive element connected to two terminals, respectively; and an actuator for driving the magnetic head. apparatus. 3. The method for measuring a thin film magnetic head according to claim 1, wherein a current is applied to one set of terminals connected to both ends of the magnetoresistive effect element, and the voltage of the other set of terminals is measured. A method for measuring a thin-film magnetic head, comprising: obtaining a resistance value of a resistance effect element; and calculating a height in a direction perpendicular to an air bearing surface of the magnetoresistance effect element based on the value. 4. The method for measuring a thin film magnetic head according to claim 3, wherein the method is performed in-process when polishing the air bearing surface of the thin film magnetic head, and the calculated vertical direction is perpendicular to the air bearing surface of the magnetoresistive element. A polishing method for a thin-film magnetic head, comprising controlling a polishing load, a processing stop, a rotation speed of a surface plate, and a supply of a processing liquid based on height data. 5. A polishing method for a thin film magnetic head according to claim 4, wherein, as a first step, a processing amount is calculated from a resistance value of a polishing processing amount detecting element formed separately from the magnetoresistive effect element. The polishing load, the number of revolutions of the platen, and the supply of the working fluid are controlled on the basis of the above method. In-process, based on the height data in the direction perpendicular to the air bearing surface of the magnetoresistive effect element calculated thereby, control the polishing pressure, processing stop, platen rotation speed, supply of processing liquid. Polishing method for thin film magnetic head. 6. The thin-film magnetic head according to claim 1, wherein
A thin-film magnetic head, wherein one set of terminals connecting both ends of a magnetoresistive effect element is formed at a cutting margin for separating individual magnetic heads. 7. A magnetic disk drive according to claim 2, wherein when data written in advance on a disk as a recording medium is read by a change in the resistance value of the magnetoresistive element, terminals 1 connected to both ends of the magnetoresistive element. A magnetic disk drive characterized by detecting a change in the resistance value of a magnetoresistive element by applying a current to a set and measuring the voltage of the other set of terminals.