JP2012234606A - Magnetic field sensor for inspecting recording element of perpendicular magnetic recording type magnetic head, recording element inspection device using the same, and method for inspecting recording element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a recording magnetic field of a perpendicular magnetic recording type magnetic head by simulating configurations of a magnetic head and a magnetic disk in an actual magnetic recording device.SOLUTION: A magnetic field sensor for inspecting a recording element is disposed near a main magnetic pole of the recording element of the perpendicular magnetic recording type magnetic head so as to face thereto and measures a magnetic field intensity distribution near the main magnetic pole. The magnetic field sensor is disposed with, in the periphery of a magnetic sensor 41, a shield 43 of a soft magnetic material larger than an area that covers the whole of the main magnetic pole 1, a return magnetic pole 3, and a recording element shield 9 of the recording element to be measured.

Description

  The present invention relates to an inspection technique for a recording element of a perpendicular magnetic recording type magnetic head.

  The hard disk magnetic storage device records and reproduces magnetic signals on a recording disk by a magnetic head. FIG. 1 shows the configuration and concept of operation of a perpendicular magnetic recording type magnetic head 14 formed by a thin film process. Recording and reproduction are performed on the magnetic disk 21 by the magnetic head 14 including the recording element 15 and the reproducing element 16. The magnetic head recording element 15 concentrates the magnetic field generated by the conductive coil 2 surrounding the magnetic core 4 in a narrow area in the main magnetic pole 1 at one end of the magnetic core 4, and causes the magnetic medium 22 of the magnetic disk 21 to be perpendicular to the disk surface. Magnetic signals are recorded by magnetizing 24 in the direction. The magnetic field generated from the magnetic core 4 forms a closed magnetic path that passes through the magnetic medium 22 from the main magnetic pole 1, passes through the soft magnetic backing layer 23, and returns to the magnetic pole 3.

  On the other hand, the magnetic signal on the magnetic medium 22 thus recorded is converted into an electric signal in the reproducing element 16 by a reproducing sensor 7 (TMR: tunneling magnetoresistive effect element) sandwiched between the upper magnetic shield 5 and the lower magnetic shield 6. Converted and read as information.

  As shown in FIG. 14, the magnetic head 14 is positioned at the end of the magnetic head slider 13 together with the electrode terminal 17, and the recording element 15 and the reproducing element 16 are electrically connected to the magnetic storage device via the electrode terminal 17. Connected.

  The magnetic head slider 13 is manufactured through the process shown in FIG. That is, a row bar cutting process for cutting a wafer 61 having a magnetic head 14 formed on a ceramic substrate into a bar-like member called a row bar 62 including several tens of sliders, the row bar 62 is mounted on a row bar holding jig 63, and a recording element , A rover roughing process including a tilting operation by a rover tilting mechanism for adjusting the size of the reproducing element, a rover finishing process for final finishing of the roughness of the rover polished surface 64 and the height of the magnetic head element, They are a groove machining process on the slider floating surface that is mounted on the groove machining jig 65 and defines the flying characteristics of the slider, and a chip cutting process that cuts out the individual sliders 13 from the row bar 62.

  Among the magnetic heads 14, the reproducing element 16 can be directly electrically connected via the electrode terminals 17 on the magnetic head slider 13, and its characteristics can be inspected during the slider manufacturing process. The recording element 15 is connected to the conductive coil 2 via the electrode terminal 17, and the magnetic core 4 is not electrically connected. To inspect the characteristics of the recording element 15, the slider 13 is suspended. It is necessary to conduct a recording / reproduction test by floating the medium disk.

  For example, Patent Document 1 discloses a technique for inspecting a recording element 15 in proximity to the recording element 15 in order to inspect the characteristics of the recording element 15 during the slider manufacturing process. In this document, “(Problem) To provide a method and apparatus for inspecting the characteristics of a magnetic field generating element capable of inspecting the recording characteristics of a thin film magnetic head element before the final inspection of an HGA (Head Gimbal Assembly). The sensor unit can be finely moved in the X, Y, and Z directions by being supported by the fine movement unit, and the thin film magnetic head element is generated at this position by moving the fine movement unit by a predetermined amount in the X and Y directions. The magnetic field is read by the sensor unit, and the voltage output from the sensor unit as a result of the reading is recorded, and the inspection unit evaluates the recording characteristics of the thin film magnetic head element based on the recording data obtained by repeating this for a predetermined number of times. (See summary). Japanese Patent Application Laid-Open No. 2004-228561 “(Problem) In manufacturing a perpendicular magnetic recording head, it is necessary to measure the flare point height in order to prevent a decrease in yield due to variations in the flare point height of the main pole. Means) In the head slider manufacturing process, the flare point height of the main magnetic pole 36 is estimated by the following procedure: (1) The magnetic field intensity is measured by a magnetic field sensor, and the point where the magnetic field intensity becomes maximum is the center of the main magnetic pole. (2) Move the measurement point along the Z direction from the center point to position the measurement value of the magnetic field strength to a certain reference value (3) Measurement point in the Z direction centering on the positioned position Is moved about ± several tens of nanometers, the attenuation rate (change rate) of the measured value of the magnetic field strength with respect to the Z direction displacement of the measurement point is calculated, normalized with the measured value, and plotted against the measured value itself. Compared to a prepared database of samples with known flare point height, the flare point height of the sample is estimated from the standard value of the rate of change "(see summary).

JP 2009-277328 A JP 2010-3332 A

  In the perpendicular magnetic recording head 14, as described in the background above, the magnetic field generated by the conductive coil 2 surrounding the magnetic core 4 is concentrated in a narrow area in the main magnetic pole 1 at one end of the magnetic core 4, and the magnetic medium 22 is placed on the disk. Magnetic signals are recorded by magnetizing 24 in a direction perpendicular to the surface. The magnetic field generated from the magnetic core 4 forms a closed magnetic path that passes through the magnetic medium 22 from the main magnetic pole 1, passes through the soft magnetic backing layer 23, and returns to the magnetic pole 3. On the other hand, in the recording element inspection methods described in Patent Document 1 and Patent Document 2, the measurement is performed by bringing the magnetic sensor for inspection close to the recording element main magnetic pole 1 without using the magnetic disk 21 including the soft magnetic backing layer 23. For this reason, if there is no structure corresponding to the soft magnetic backing layer 23 in the vicinity of the magnetic sensor or if the structure is not sufficiently large, a closed magnetic path is not formed, and the characteristics of the recording element 15 cannot be correctly inspected. In Patent Document 1 and Patent Document 2, the reproducing element 16 of an existing magnetic head is used as the magnetic sensor. However, such a sensor cannot always reproduce the soft magnetic backing layer 23 facing the recording element 15. In some cases, the magnetic field distribution is different from the actual distribution.

  Therefore, in the present invention, a large shield is arranged around the magnetic sensor so that the magnetic field emitted from the recording element main magnetic pole 1 enters the magnetic sensor through the shield and returns to the return magnetic pole 3. 14 and a magnetic disk sensor simulating the configuration of the magnetic disk 21.

  In order to solve the above problems, for example, the configuration described in the claims is adopted.

  Although the present application includes a plurality of means for solving the above-described problems, if one example of the magnetic sensor for recording element inspection of the present invention is given, it is arranged so as to face the vicinity of the main magnetic pole of the recording element of the perpendicular magnetic recording type magnetic head. And a magnetic field sensor for inspecting a recording element for measuring a magnetic field strength distribution in the vicinity of the main magnetic pole, the area surrounding the main magnetic pole of the recording element to be measured, the return magnetic pole, and the entire recording element shield. A large soft magnetic material shield is arranged.

  If an example of the recording element inspection apparatus of the present invention is given, the output of a magnetic field sensor arranged so that the magnetic field intensity distribution in the vicinity of the main magnetic pole of the recording element of the perpendicular magnetic recording type magnetic head is opposed to the vicinity of the main magnetic pole. A recording element inspection apparatus for a perpendicular magnetic recording type magnetic head that measures as follows: a shield of soft magnetic material larger than the area covering the main and return poles of the recording element to be measured and the entire recording element shield around the magnetic sensor And a means for scanning the magnetic field sensor relative to the recording element to be measured.

  As an example of the recording element inspection method of the present invention, the output of a magnetic field sensor arranged so that the magnetic field strength distribution in the vicinity of the main pole of the recording element of the perpendicular magnetic recording type magnetic head is opposed to the vicinity of the main pole. A perpendicular magnetic recording type magnetic head recording element inspection method for measuring as follows: a shield of soft magnetic material larger than the area covering the main magnetic pole and return magnetic pole of the recording element to be measured and the entire recording element shield around the magnetic sensor Is used to apply a high-frequency signal to the recording element to be measured, and to relatively displace the magnetic field sensor in the vicinity of the recording element to detect the output of the magnetic field sensor.

  According to the present invention, it is possible to provide a sensor that simulates the configuration of an actual magnetic recording head and a magnetic disk in which a magnetic field emitted from a recording element main magnetic pole enters a magnetic sensor around a shield and returns to a return magnetic pole. Accurate inspection of recording element characteristics is possible.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is explanatory drawing which shows the structure and operation | movement concept of a perpendicular magnetic recording head. It is explanatory drawing which shows the conventional structure at the time of detecting the recording magnetic field of a perpendicular magnetic recording head with the magnetic sensor pinched | interposed with the shield. It is explanatory drawing which shows a structure in the case of using the magnetic head for normal magnetic memory devices for a magnetic sensor, and measuring the recording magnetic field of the main magnetic pole vicinity. It is explanatory drawing which shows a structure in the case of using the magnetic head for a normal magnetic storage device for a magnetic sensor, and measuring the recording magnetic field of a recording element shield edge part. FIG. 5 is an explanatory diagram showing a configuration in a case where a shield larger than a region covering the main magnetic pole and return magnetic pole of the recording element to be measured and the entire recording element shield is added to the magnetic sensor, and the recording magnetic field in the vicinity of the main magnetic pole is measured. . Explanatory drawing showing a configuration when a recording magnetic field at the end of the recording element shield is measured by adding a shield larger than the area covering the main magnetic pole and return magnetic pole of the recording element to be measured and the entire recording element shield to the magnetic sensor. It is. It is a figure which shows an example of the result of having calculated by simulation that the two-dimensional recording magnetic field distribution of the main magnetic pole of a to-be-measured recording element, a return magnetic pole, and a recording element shield vicinity assumes that there is no shield in the magnetic field measurement sensor side. The figure which shows an example of the result of having calculated the two-dimensional recording magnetic field distribution in the vicinity of the main magnetic pole, return magnetic pole, and recording element shield of the recording element to be measured by simulation assuming that the shield on the magnetic field measuring sensor side covers the entire surface It is. An example of the result of calculating the two-dimensional recording magnetic field distribution in the vicinity of the main magnetic pole, return magnetic pole, and recording element shield of the recording element to be measured by simulation assuming that the shield on the magnetic field measurement sensor side covers only the vicinity of the main magnetic pole FIG. Assuming that the main magnetic pole, return magnetic pole, and recording element shield near the recording element shield are two-dimensional recording magnetic field distributions. The shield on the magnetic field measurement sensor side covers only the end of the return magnetic pole and the write shield in the cross-track direction. It is a figure which shows an example of the result calculated by simulation. It is a figure which shows the recording magnetic field distribution along the line | wire of the cross track direction which passes along the main pole of a to-be-measured recording element based on the simulation result of FIGS. FIG. 11 is a detailed diagram showing a recording magnetic field distribution along a cross-track direction line passing through the main magnetic pole of the recording element to be measured based only on the vicinity of the main magnetic pole based on the simulation results of FIGS. FIG. 11 is a detailed view showing a recording magnetic field distribution along a cross-track direction line passing through the main magnetic pole of the recording element to be measured based only on the vicinity of the recording element shield end, based on the simulation results of FIGS. It is the schematic diagram which shows the direction of a schematic diagram of a magnetic head slider, and an orthogonal coordinate axis. It is a schematic diagram which shows an example of the apparatus structure for enforcing the inspection method of the recording magnetic field by this invention. It is a schematic diagram which shows the manufacturing process of a magnetic head slider.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In order to realize a magnetic field sensor simulating the configuration of an actual magnetic recording head and a magnetic disk, a magnetic field emitted from the recording element main magnetic pole enters the magnetic sensor around the shield and returns to the return magnetic pole. A thin film type in which a shield of a soft magnetic material larger than the area covering the main magnetic pole, the return magnetic pole, and the entire recording element shield and at least the thickness of the soft magnetic backing layer of the magnetic medium paired with the recording head is disposed around A perpendicular magnetic recording element inspection apparatus, a perpendicular magnetic recording element inspection method, and an example of a magnetic field sensor used in the inspection apparatus will be described.

  FIG. 1 is an explanatory diagram showing the configuration and operation concept of a perpendicular magnetic recording head. The magnetic head 14 includes a recording element 15 and a reproducing element 16. The recording element 15 includes a recording element main magnetic pole 1, a conductor coil 2, a recording element return magnetic pole 3, a magnetic core 4, and a recording element shield 9. The reproduction element 16 includes a reproduction element upper shield 5, a reproduction element lower shield 6, and a reproduction sensor 7. Among the constituent elements of the recording element 15, the recording element main magnetic pole 1, the recording element return magnetic pole 3, and the recording element shield 9, and among the constituent elements of the reproducing element 16, the reproducing element upper shield 5, the reproducing element lower shield 6, The reproduction sensor 7 is exposed on the surface of the slider air bearing surface 8. On the other hand, the magnetic disk 21 includes a recording layer 22 and a soft magnetic backing layer 23. In perpendicular magnetic recording, a current is passed through the conductor coil 2 to generate a recording magnetic field from the recording element main pole 1 through the magnetic core 4, and the recording layer sandwiched between the soft magnetic backing layer 23 of the magnetic disk 21 and the recording element main pole 1. 22 is a magnetic recording system in which perpendicular magnetization 24 is given in a direction perpendicular to the surface of the magnetic disk 21 to obtain magnetic information bits. The magnetic flux guided to the soft magnetic backing layer 23 passes through the soft magnetic backing layer 23 and returns to the return magnetic pole 3 to form a magnetic closed circuit together with the magnetic core 4 and the recording element main magnetic pole 1. The recording element shield 9 is provided for the purpose of increasing the magnetic field gradient at the track end of the recording magnetic field emitted from the recording element main magnetic pole 1. An electric signal modulated by placing a recording signal is input to the conductor coil 2, while the magnetic disk 21 is rotated and relatively moved in the direction of the arrow in FIG. The recording tracks bearing the shape are formed concentrically.

  When the magnetic head 14 moves relative to the rotating magnetic disk 21, a dynamic pressure is generated between the magnetic head 14 and the magnetic disk 21, and the magnetic head 14 floats with respect to the magnetic disk 21 via the slider flying surface 8. To do. FIG. 14 is a schematic diagram of the magnetic head slider 13 for facilitating the explanation of the present invention and a schematic diagram showing the directions of the orthogonal coordinate axes used for the explanation of the present invention. The surface of the magnetic head slider 13 facing the magnetic disk 21 is the slider flying surface 8, and the recording element 15 and the reproducing element 16 of the magnetic head 14 are exposed there. In this specification, the direction along the relative motion of the magnetic head 14 and the magnetic disk 21 is the “down track direction”, the direction perpendicular to the slider air bearing surface 8 is the “cross track direction”, and the slider air bearing surface 8 The normal direction is referred to as “magnetic head slider air bearing surface normal direction”. The magnetic head slider 13 has an electrode terminal 17 for exchanging electrical signals between the magnetic head 14 and a circuit system on the system side.

  In order to improve the performance of the magnetic head 14 and stable production, it is essential to inspect the magnetic characteristics of the recording element 15 and the reproducing element 16. The reproducing element 16 is a resistor that shows the electric resistance of the reproducing sensor 7 itself, and its basic magnetic characteristic is that a change in resistance value when an external magnetic field is applied to the element is measured via the electrode terminal 17. By doing so, it can be easily inspected. However, the recording element 15 needs to measure a recording magnetic field generated from the recording element main magnetic pole 1 by passing a current through the electrode terminal 17 through the conductor coil 2 wound around the magnetic core 4. It's not easy. In general, a magnetic head slider 13 to be measured is attached to a simulated magnetic storage device having a magnetic disk medium for measurement, and the recording head 15 actually performs magnetic recording on the magnetic disk medium for measurement. Then, the recorded signal track is read by the reproducing element 16 on the same magnetic head slider 13 to inspect characteristics such as the strength and width of the recording signal, and the magnetic characteristics of the recording head 15 are evaluated. However, in the magnetic characteristic evaluation of the recording element 15 by the method of reading back the signal once recorded on the magnetic disk medium for measurement with such a simulated magnetic storage device, measurement cannot be performed until the magnetic head slider 13 is completed. Development of an inspection method for directly measuring a recording magnetic field emitted from the recording element 15 with a magnetic sensor is in progress because there is a difficulty that a detailed magnetic field distribution in the vicinity of the recording element 15 cannot be evaluated. An example of the magnetic sensor is the reproducing element 14 mounted on another magnetic head slider 13. In FIG. 2, a magnetic field generated by the perpendicular magnetic recording head 15 is recorded by a magnetic sensor 41 sandwiched between shields 42. The structure at the time of detection is shown as an explanatory diagram.

  In order to distinguish from the reproducing element 16 mounted on the magnetic head slider 13 to be measured, this magnetic sensor 41 is referred to as a magnetic sensor 41 for measuring a magnetic field, and further distinguished from the shield of the magnetic sensor of the system according to the present invention described later. Therefore, the magnetic shield attached to the magnetic sensor 41 is referred to as a magnetic field measurement magnetic sensor normal shield 42, and the magnetic sensor assembly including these components is referred to as a magnetic field measurement magnetic sensor magnetic shield assembly 40. .

  The magnetic field measurement magnetic sensor 41 is connected to the measurement circuit via the electrode terminal 17 similar to the magnetic head slider 13 to be measured. FIG. 15 is a schematic diagram showing an example of a device configuration for carrying out the recording magnetic field inspection method according to the present invention. While applying a sinusoidal high frequency signal with a constant effective voltage from one of the ports of the network analyzer to the recording element 15 to be measured, it is used for magnetic field measurement via a bias T for separating a DC signal and an RF signal from a constant current power source. By applying a constant current to the magnetoresistive effect element of the magnetic sensor 41 and slightly displacing the vicinity of the recording element 15, the intensity change of the output sine high-frequency signal generated in the magnetoresistive effect element is applied via a bias T and an amplifier. Then, the map information of the two-dimensional data is obtained by taking in the other port of the network analyzer and processing the data by comparing the signal intensity comparison and phase comparison of both ports with the position information of the magnetic sensor 41 positioning stage. Get.

  In FIG. 2, as an explanatory diagram for bringing the magnetic field measurement magnetic sensor assembly 40 closer to the recording element 15 to be measured, the shield 42 of the magnetic sensor 41 for magnetic field measurement is connected to the main magnetic pole 1 and the return magnetic pole 3 of the recording element 15 to be measured. The magnetic core 4 and the recording element described in FIG. 1 are used for measurement in the direction perpendicular to the direction connecting the two, that is, the direction parallel to the cross track direction of the return magnetic pole 3 and the recording element shield 9. It is desirable that a magnetic closed circuit as formed by the main magnetic pole 1, the recording layer 22, the soft magnetic backing layer 23, and the return magnetic pole 3 is formed. Accordingly, the shield 42 of the magnetic field measurement sensor is rather arranged along the direction connecting the main magnetic pole 1 and the return magnetic pole 3 of the recording element 15 to be measured, as shown in FIG. As a result, a closed circuit including the magnetic core 4, the recording element main magnetic pole 1, the magnetic sensor for magnetic field measurement 42, and the return magnetic pole 3 is formed to simulate the configuration of the magnetic head 14 and the magnetic disk 21 in an actual magnetic storage device. It is desirable to do.

  In FIG. 3, the magnetic field measuring magnetic sensor 41 is drawn at a position where the recording magnetic field in the vicinity of the main pole 1 is measured, but the entire element assembly of the recording element 15 to be measured, that is, the main pole 1, the return pole 3, In order to evaluate the magnetic field distribution of the entire recording element shield 9 in detail, the magnetic sensor 41 for magnetic field measurement must be scanned relative to the entire element assembly of the recording element 15 to be measured. FIG. 4 shows the arrangement of the sensor 41 and the shield 42 when the magnetic field measuring magnetic sensor 41 measures the magnetic field near the end of the recording element shield 9 of the recording element 15 to be measured. As can be seen from FIG. 4, when the reproducing element 16 used in a normal magnetic storage device is diverted to the magnetic sensor assembly 40 for magnetic field measurement, the width of the shield 42 in the down-track direction is the recording element 15 to be measured. Thus, the recording element main magnetic pole 1 to be measured protrudes beyond the range covered by the magnetic sensor shield 42 for magnetic field measurement, which is narrower than the width of the return magnetic pole 3 and the recording element shield 9 in the cross-track direction. That is, when measuring the position of the recording element shield 9 end of the recording element 15 to be measured, the closed circuit of the magnetic core 4, the recording element main magnetic pole 1, the magnetic field measuring magnetic sensor shield 42, and the return magnetic pole 3. Are not formed, and the configuration of the magnetic recording head 14 and the magnetic disk 21 in an actual magnetic storage device cannot be completely simulated. Unlike an electric circuit, a magnetic circuit does not mean that magnetic flux does not pass if it is open even at one location. However, in order to evaluate the magnetic characteristics of the recording element 15 to be measured more accurately, the actual magnetic circuit is used as much as possible. It is desirable to perform measurement in a manner that simulates the configuration of the recording element 15, the recording layer 22 of the magnetic disk 21, and the soft magnetic backing layer 23 in the storage device.

  Based on the above concept, in the embodiment of the present invention, as shown in FIG. 5, the magnetic characteristics of the perpendicular magnetic recording element 15 are applied to the magnetic sensor 41 for magnetic field measurement for evaluating based on the direct measurement of the recording magnetic field. It is characterized in that a magnetic field sensor to which a whole surface covering shield 43 larger than a region covering the main magnetic pole 1 and the return magnetic pole 3 of the measurement recording element 15 and the entire recording element shield 9 is added is used. FIG. 5 is an explanatory diagram showing a configuration in the case where the magnetic sensor 41 for magnetic field measurement to which the whole surface covering shield 43 is added measures a recording magnetic field in the vicinity of the main magnetic pole 1. When the magnetic field measuring magnetic sensor 41 is at the position shown in FIG. 5, a closed circuit including the magnetic core 4, the recording element main magnetic pole 1, the magnetic field measuring magnetic sensor shield 43, and the return magnetic pole 3 is formed. The recording element 15, the recording layer 22 of the magnetic disk 21, and the soft magnetic backing layer 23 can be simulated.

  Further, when scanning relative to the entire element assembly, the magnetic field measuring magnetic sensor 41 measures the magnetic field in the vicinity of the end of the recording element shield 9 of the recording element 15 to be measured and the shield 41. The arrangement of 43 is shown in FIG. As can be seen from FIG. 6, if the shield 43 of the magnetic sensor for magnetic field measurement is sufficiently large as in the embodiment of the present invention, the magnetic sensor for magnetic field measurement 41 is positioned at the end of the recording element shield 9. However, the main magnetic pole is covered with the shield 43 of the magnetic sensor for measuring the magnetic field, and a closed circuit of the magnetic core 4, the recording element main magnetic pole 1, the magnetic sensor for magnetic field measurement 43, and the return magnetic pole 3 is formed. The configuration of the recording element 15, the recording layer 22 of the magnetic disk 21, and the soft magnetic backing layer 23 in the apparatus can be simulated in a close form.

  In order to verify the above concept, the main magnetic pole 1, the return magnetic pole 3, the recording element shield 9 constituting the recording element 15, and a magnetic sensor shield for measuring the magnetic characteristics thereof (normal shield 42 or full-cover shield 43). An electromagnetic field simulation was performed using FIG. 7 shows an example of a result calculated by simulation assuming that there is no shield on the magnetic field measurement sensor side in the vicinity of the main magnetic pole 1, the return magnetic pole 3 and the recording element shield 9 of the recording element 15 to be measured. FIG. 4 is an explanatory diagram showing the arrangement of the main magnetic pole 1, the return magnetic pole 3, and the recording element shield 9 corresponding to the distribution of the figure. A large peak of the magnetic field strength is observed at a position corresponding to the main magnetic pole 1, and the rest of the distribution is relatively flat.

  8 shows a two-dimensional recording magnetic field distribution in the vicinity of the main magnetic pole 1, the return magnetic pole 3 and the recording element shield 9 of the recording element to be measured as in FIG. 7, and the shield on the magnetic field measurement sensor side covers the entire surface. FIG. 4 is a diagram illustrating an example of a result calculated by simulation under assumption, and an explanatory diagram illustrating an arrangement of the main magnetic pole 1, the return magnetic pole 3, the recording element shield 9, and the entire cover shield 43 on the sensor side corresponding to the distribution of the diagram. . The peak value of the magnetic field strength corresponding to the position of the main magnetic pole 1 is about 50% larger than that in the case of FIG. 7, and the magnetic field strength distribution at other positions is also high overall. The arrangement in FIG. 8 is considered to simulate the configuration of the recording element 15 in an actual magnetic storage device, the recording layer 22 of the magnetic disk 21, and the soft magnetic backing layer 23 in a close form.

  On the other hand, FIG. 9 shows a two-dimensional recording magnetic field distribution in the vicinity of the main magnetic pole 1, return magnetic pole 3 and recording element shield 9 of the recording element 15 to be measured, similar to the above, and the shield on the magnetic field measurement sensor side is only in the vicinity of the main magnetic pole 1. FIG. 5 is a diagram showing an example of a result calculated by simulation on the assumption that the cover is covered, and the arrangement of the main magnetic pole 1, the return magnetic pole 3, the recording element shield 9, and the partial shield 42 on the sensor side corresponding to the distribution of the figure. It is explanatory drawing shown. In order to save calculation resources, the simulation is performed symmetrically about the position of the main magnetic pole, and the magnetic sensor shield 42 is arranged with a width of 3 μm from the main magnetic pole, so that it is covered by the magnetic sensor shield 42. The width of the range is 6 μm centering on the main pole. Although the peak value of the magnetic field strength of the main pole 1 is almost the same as that in FIG. 8 (error 1.1%), the magnetic field strength distribution in the portion not covered by the shield 42 is rather the magnetic field due to the configuration without the shield in FIG. Close to the simulation result of intensity distribution.

  Finally, FIG. 10 shows the two-dimensional recording magnetic field distribution in the vicinity of the main magnetic pole 1, the return magnetic pole 3 and the recording element shield 9 of the recording element 15 to be measured as described above. The figure which shows an example of the result calculated by simulation on the assumption that it has covered only the end part of the cross pole direction of the return pole 3 and the recording shield 9, and the main pole 1, the return pole 3, the recording corresponding to the distribution of the figure It is explanatory drawing which shows arrangement | positioning of the element shield 9 and the partial shield 42 by the side of a sensor. Similar to the above, for the purpose of saving calculation resources, the simulation is performed symmetrically with respect to the main magnetic pole position, and the magnetic sensor shield 42 is arranged at a position of 10 μm to 13 μm with a width of 3 μm from the main magnetic pole position. Therefore, the area covered by the magnetic sensor shield 42 is drawn at two locations of 3 μm at both ends of the recording shield in the cross-track direction across the main pole, but this is for the convenience of calculation. It does not mean that it is assumed to measure two locations at once. The peak value of the magnetic field strength of the main magnetic pole 1 is almost the same as that without the shield in FIG. 7 (error 0.6%), but the magnetic field strength distribution of the portion covered by the shield 42 is the entire surface covering of FIG. It is relatively close to the simulation result of the magnetic field strength distribution by the shield configuration.

  FIGS. 9 and 10 simulate the case where the reproducing element 16 used in an ordinary magnetic storage device is diverted to the magnetic field measurement magnetic sensor assembly 40 and the measurement is performed. When the magnetic field measuring sensor 41 scans the entire recording element 15 assembly at the center of the illustrated magnetic sensor shield 42, the magnetic field measuring magnetic sensor 41 moves together with the magnetic sensor shield 42, and the recording to be measured. The element 15 is scanned. Therefore, the magnetic field measurement sensor 41 scans the entire recording element 15 assembly, measures the magnetic field strength at each point, and plots it two-dimensionally. As a result, FIG. This is considered to be relatively close to the simulation result of the magnetic field intensity distribution by the configuration of the whole surface shield.

  However, as described with reference to FIG. 4, when the magnetic field measurement sensor 41 of a normal reproducing element that only partially covers the measured recording element 15 is used for measurement, the measured recording element main magnetic pole 1 is In an arrangement protruding from the area covered by the magnetic field measurement magnetic sensor shield 42, a closed circuit of the magnetic core 4, the recording element main magnetic pole 1, the magnetic field measurement magnetic sensor shield 42, and the return magnetic pole 3 is not formed. The configuration of the magnetic recording head 14 and the magnetic disk 21 in the apparatus cannot be completely simulated. Therefore, the magnetic field measurement sensor 41 is scanned over the entire recording element 15 assembly, and the measured values of the magnetic field strength at each point are measured and plotted two-dimensionally. It does not agree with the magnetic field intensity distribution by the configuration of

  In order to examine this more quantitatively, the line profile of the magnetic field strength along the line in the cross track direction passing through the main pole 1 is extracted and verified in detail with respect to the two-dimensional distribution of the magnetic field strength of FIGS. To do. FIG. 11 shows that the recording magnetic field distribution along the line in the cross track direction passing through the main magnetic pole 1 of the recording element 15 to be measured 51 when it is assumed that there is no shield, and that the shield 43 covers the entire surface of the recording element. In the case 52, it is assumed that the shield 42 covers only the vicinity of the main magnetic pole 53, and the case 54 in which it is assumed that the shield 42 covers only the recording element shield end portion is overlapped. FIG. As seen in the two-dimensional distribution of the magnetic field strength in FIGS. 7 to 10, it is assumed that the shield 43 covers the entire surface of the recording element 15, and the shield 42 covers only the vicinity of the main magnetic pole 1. Assuming that the peak value of the magnetic field strength of 53 is almost the same (error 1.1%), and assuming that the shield 42 covers only the end of the recording element shield 9, the shield 42 is also the recording element shield 9. As for the portion covering, the value is relatively close to 52 when it is assumed that the shield 43 covers the entire surface of the recording element 15.

  However, if the magnetic sensor for magnetic field measurement, usually the shield 42, looks closely at the comparison of the portion covering the recording element 15, the width of the shield is still small and a sufficient magnetic circuit is not formed. It can be seen that the magnitude of the magnetic field strength is different between the entire surface shield 43 and the normal shield 42 to the extent that it cannot be said that it is a calculation error. 12 is an enlarged view of a portion where the normal shield 42 covers the recording element 15 in the vicinity of the main magnetic pole in FIG. Comparing 52 when it is assumed that the shield 43 covers the entire surface of the recording element 15 and 53 when it is assumed that the shield 42 covers only the vicinity of the main magnetic pole 1, the value of the peak magnetic field intensity is as described above. Thus, 2.13 [kOe] and 2.10 [kOe] respectively, with an error of 1.1%, there is almost no change. On the other hand, FIG. 13 is an enlarged view of a portion where the normal shield 42 covers the recording element 15 at the end of the recording element shield 9 of FIG. Comparing 52 when it is assumed that the shield 43 covers the entire surface of the recording element 15 and 54 when it is assumed that the shield 42 covers only the end portion of the recording element shield, There is a 7.1% difference between 259.0 [Oe] and 276.2 [Oe]. Accordingly, when more detailed magnetic field distribution measurement is desired to be performed more quantitatively, the magnetic pole for magnetic field measurement 41 according to the embodiment of the present invention can measure at least the main pole regardless of where the recording element 15 is measured. 1 is essential, and more preferably, the entire recording element 15 assembly is shielded wherever the magnetic field measuring magnetic sensor 41 measures the recording element 15. A magnetic sensor 41 for measuring a magnetic field having a shield 43 having a size covered with 43 is preferable.

  Further, with respect to the shield thickness, in order to simulate the configuration of the recording element 15 in the actual magnetic storage device, the recording layer 22 of the magnetic disk 21, and the soft magnetic backing layer 23, the recording element to be measured in the actual magnetic storage device is used. As long as the soft magnetic backing layer 23 of the magnetic disk 21 used in combination with the magnetic disk 21 has a thickness equal to or greater than that.

  Further, in this embodiment, the magnetic field measurement magnetic sensor 41 has been described by taking a tunnel type magnetoresistive effect element used in an actual magnetic storage device as an example. Any magnetic sensor may be used as long as it provides a proportional output. For example, it may be a Hall element, a superconducting quantum interference (SQUID) element, a fluxgate element, or a magnetic impedance element.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

1 recording element main pole,
2 conductor coil,
3 Recording element return magnetic pole,
4 magnetic core 5 reproducing element upper shield 6 reproducing element lower shield 7 reproducing sensor,
8 slider air bearing surface 9 recording element shield 13 magnetic head slider 14 magnetic head 15 recording element 16 reproducing element 17 electrode terminal 21 magnetic disk 22 recording layer 23 soft magnetic backing layer 24 perpendicular magnetization 40 magnetic sensor for magnetic field measurement magnetic shield assembly 41 magnetic field measurement Magnetic sensor 42 Magnetic field measurement magnetic sensor Normal shield 43 Magnetic field measurement magnetic sensor Full-cover shield 51 Magnetic field measurement magnetic sensor without shield 52 Magnetic field measurement magnetic sensor with full-cover shield 53 Magnetic field measurement magnetic sensor 54 When a normal shield is disposed in the vicinity of the main magnetic pole 54 When a normal shield is disposed at the return magnetic pole end of the magnetic sensor for magnetic field measurement 61 Wafer 62 Rover 63 Rover holding jig 64 Rover polished surface 65 Air bearing surface processing jig

Claims (15)

A magnetic field sensor for recording element inspection that is arranged so as to face the vicinity of the main magnetic pole of the recording element of a perpendicular magnetic recording system magnetic head and measures the magnetic field intensity distribution in the vicinity of the main magnetic pole,
Recording element inspection of a perpendicular magnetic recording type magnetic head characterized in that a shield made of a soft magnetic material larger than the area covering the main magnetic pole and return magnetic pole of the recording element to be measured and the entire recording element shield is arranged around the magnetic sensor Magnetic field sensor. The magnetic field sensor for recording element inspection according to claim 1,
A magnetic field sensor for recording element inspection of a perpendicular magnetic recording type magnetic head, wherein the thickness of the shield is equal to or greater than the thickness of a soft magnetic backing layer of a magnetic medium paired with a recording element to be measured. The magnetic field sensor for recording element inspection according to claim 1 or 2,
A magnetic field sensor for recording element inspection of a perpendicular magnetic recording type magnetic head, wherein the shield is arranged along a direction connecting a main magnetic pole and a return magnetic pole of a recording element to be measured. The magnetic field sensor for recording element inspection according to claim 3,
A magnetic field sensor for recording element inspection of a perpendicular magnetic recording type magnetic head, wherein the shield is disposed on both sides of the magnetic sensor in a cross-track direction. In the magnetic field sensor for recording element inspection according to any one of claims 1 to 4,
The magnetic sensor is one of a magnetoresistive element, a Hall element, a superconducting quantum interference (SQUID) element, a fluxgate element, and a magnetic impedance element. Magnetic field sensor. This is a recording element inspection device for a perpendicular magnetic recording system magnetic head that measures the magnetic field strength distribution in the vicinity of the main magnetic pole of the recording element of the perpendicular magnetic recording system magnetic head as the output of a magnetic field sensor arranged to face the vicinity of the main magnetic pole. And
Around the magnetic sensor, a magnetic field sensor in which a shield of a soft magnetic material larger than a region covering the main magnetic pole and the return magnetic pole of the recording element to be measured and the entire recording element shield is disposed;
A recording element inspection apparatus for a perpendicular magnetic recording type magnetic head, comprising: means for scanning the magnetic field sensor relative to the recording element to be measured. The recording element inspection apparatus according to claim 6,
A recording element inspection apparatus for a perpendicular magnetic recording type magnetic head, wherein the thickness of the shield of the magnetic field sensor is equal to or greater than the thickness of the soft magnetic backing layer of the magnetic medium paired with the recording element to be measured. In the recording element inspection apparatus according to claim 6 or 7,
A recording element inspection apparatus for a perpendicular magnetic recording type magnetic head, wherein the shield of the magnetic field sensor is arranged along a direction connecting a main magnetic pole and a return magnetic pole of a recording element to be measured. The recording element inspection apparatus according to claim 8,
A recording element inspection apparatus for a perpendicular magnetic recording type magnetic head, wherein shields of the magnetic field sensor are arranged on both sides of the magnetic sensor in a cross-track direction. In the recording element inspection apparatus according to any one of claims 6 to 9,
Recording device inspection apparatus for a perpendicular magnetic recording system magnetic head, wherein the magnetic sensor is any one of a magnetoresistive element, a Hall element, a superconducting quantum interference (SQUID) element, a fluxgate element, and a magnetic impedance element . This is a recording element inspection method for a perpendicular magnetic recording type magnetic head that measures the magnetic field strength distribution in the vicinity of the main pole of the recording element of the perpendicular magnetic recording type magnetic head as the output of a magnetic field sensor arranged to face the vicinity of the main pole. And
Use a magnetic field sensor in which a shield of soft magnetic material larger than the area covering the main magnetic pole and return magnetic pole of the recording element to be measured and the entire recording element shield is arranged around the magnetic sensor,
A recording element inspection method for a perpendicular magnetic recording type magnetic head, wherein a high frequency signal is applied to the recording element to be measured and the magnetic field sensor is relatively displaced in the vicinity of the recording element to detect an output of the magnetic field sensor. The recording element inspection method according to claim 11,
A recording element inspection method for a perpendicular magnetic recording type magnetic head, wherein the thickness of the shield of the magnetic field sensor is equal to or greater than the thickness of the soft magnetic backing layer of the magnetic medium paired with the recording element to be measured. In the recording element inspection method according to claim 11 or 12,
A recording element inspection method for a perpendicular magnetic recording type magnetic head, wherein the shield of the magnetic field sensor is disposed along a direction connecting a main magnetic pole and a return magnetic pole of a recording element to be measured. The recording element inspection method according to claim 13,
A method of inspecting a recording element of a perpendicular magnetic recording type magnetic head, wherein the shield of the magnetic field sensor is arranged on both sides of the magnetic sensor in the cross-track direction. In the recording element inspection method according to any one of claims 11 to 14,
A recording element inspection method for a perpendicular magnetic recording type magnetic head, wherein the magnetic sensor is any one of a magnetoresistive element, a Hall element, a superconducting quantum interference (SQUID) element, a fluxgate element, and a magnetic impedance element .

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