Detecting wedge angle with a third electric lapping guide (ELG) during manufacture of a magnetic head

In one embodiment, a magnetic head includes a read element, a write element, a write upper shield positioned in a downtrack direction from the write element, a first resistance detecting element positioned on an air bearing surface (ABS) side in a first cross-track direction from the read element, a second resistance detecting element positioned on the ABS side in a second cross-track direction from the write element, a third resistance detecting element positioned on the ABS side in a third cross-track direction from the write upper shield, a protective film positioned near the read and write elements, first, second, and third resistance detecting elements, and the write upper shield, and terminals positioned on an end surface side of the magnetic head, the terminals being coupled to the write element, the read element, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element.

FIELD OF THE INVENTION

The present invention relates to manufacturing magnetic heads, and more particularly, to using a third ELG to detect wedge angle during manufacture of a magnetic head.

BACKGROUND

Due in part to advances in manufacturing of hard disk drives (HDDs), such as higher recording densities and lower costs, the HDD has spread from an external recording device for a large-scale computer to playing a major role in digital information recording media centered in the information technology (IT) field. As shown inFIG. 5, a HDD is constructed from a magnetic disk1for recording magnetic information and a magnetic head slider3installed at the tip of a gimbal2. In this structure, magnetic information is read from and written to the magnetic disk1while the magnetic head slider3is flying just barely above the recording medium on the order of nanometers above the magnetic disk1being rotated by a spindle motor.

To achieve higher recording densities, the recording area per bit on the magnetic disk1must be reduced, and as a result, perpendicular magnetic recording methods for implementing this become practical. In order to improve the recording density in perpendicular magnetic recording methods, in addition to high precision finishing of the element height of a read element embedded in the magnetic head slider3, the element height of the write element must be finished with a high degree of precision. In addition to a resistance detecting element for detecting the element height for use by the read element, a resistance detecting element for detecting the element height for use by the write element may also be formed according to some conventional methods. Technologies are also being developed to conduct high precision finishing of the element height of the write element based on the element heights derived from the resistance values of the resistance detecting elements described above in the air bearing surface polishing process.

SUMMARY

In one embodiment, a magnetic head includes a read element, a write element, a write upper shield positioned in a downtrack direction from the write element, a first resistance detecting element positioned on an air bearing surface (ABS) side in a first cross-track direction from the read element, a second resistance detecting element positioned on the ABS side in a second cross-track direction from the write element, a third resistance detecting element positioned on the ABS side in a third cross-track direction from the write upper shield, a protective film positioned near the read element, the write element, the write upper shield, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element, and terminals positioned on an end surface side of the magnetic head, the terminals being coupled to the write element, the read element, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element.

According to another embodiment, a method for forming a magnetic head includes forming a read element, forming a write element, forming a write upper shield, forming a first resistance detecting element near the read element in a first cross-track direction from the read element, forming a second resistance detecting element near the write element in a second cross-track direction from the write element, forming a third resistance detecting element near the write upper shield in a third cross-track direction from the write upper shield, forming a protective film above the read element, the write element, the write upper shield, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element, and coupling the write element, the read element, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element to terminals which are positioned on an end surface of the magnetic head.

Any of these embodiments may be implemented in a magnetic data storage system such as a disk drive system, which may include a magnetic head, a drive mechanism for passing a magnetic storage medium (e.g., hard disk) over the head, and a control unit electrically coupled to the head for controlling operation of the head.

DETAILED DESCRIPTION

In one general embodiment, a magnetic head includes a read element, a write element, a write upper shield positioned in a downtrack direction from the write element, a first resistance detecting element positioned on an air bearing surface (ABS) side in a first cross-track direction from the read element, a second resistance detecting element positioned on the ABS side in a second cross-track direction from the write element, a third resistance detecting element positioned on the ABS side in a third cross-track direction from the write upper shield, a protective film positioned near the read element, the write element, the write upper shield, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element, and terminals positioned on an end surface side of the magnetic head, the terminals being coupled to the write element, the read element, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element.

According to another general embodiment, a method for forming a magnetic head includes forming a read element, forming a write element, forming a write upper shield, forming a first resistance detecting element near the read element in a first cross-track direction from the read element, forming a second resistance detecting element near the write element in a second cross-track direction from the write element, forming a third resistance detecting element near the write upper shield in a third cross-track direction from the write upper shield, forming a protective film above the read element, the write element, the write upper shield, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element, and coupling the write element, the read element, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element to terminals which are positioned on an end surface of the magnetic head.

Referring now toFIG. 1, there is shown a disk drive100in accordance with one embodiment of the present invention. As shown inFIG. 1, at least one rotatable magnetic disk112is supported on a spindle114and rotated by a disk drive motor118. The magnetic recording on each disk is typically in the form of an annular pattern of concentric data tracks (not shown) on the disk112.

At least one slider113is positioned near the disk112, each slider113supporting one or more magnetic read/write heads121. As the disk rotates, slider113is moved radially in and out over disk surface122so that heads121may access different tracks of the disk where desired data are recorded and/or to be written. Each slider113is attached to an actuator arm119using a suspension115. The suspension115provides a slight spring force which biases slider113against the disk surface122. Each actuator arm119is attached to an actuator127. The actuator127as shown inFIG. 1may be a voice coil motor (VCM). The VCM comprises a coil movable within a fixed magnetic field, the direction and speed of the coil movements being controlled by the motor current signals supplied by controller129.

During operation of the disk storage system, the rotation of disk112generates an air bearing between slider113and disk surface122that exerts an upward force or lift on the slider. The air bearing thus counter-balances the slight spring force of suspension115and supports slider113off and slightly above the disk surface by a small, substantially constant spacing during normal operation. Note that in some embodiments, the slider113may slide along the disk surface122.

The various components of the disk storage system are controlled in operation by control signals generated by control unit129, such as access control signals and internal clock signals. Typically, control unit129comprises logic control circuits, storage (e.g., memory), and a microprocessor. The control unit129generates control signals to control various system operations such as drive motor control signals on line123and head position and seek control signals on line128. The control signals on line128provide the desired current profiles to optimally move and position slider113to the desired data track on disk112. Read and write signals are communicated to and from read/write heads121by way of recording channel125.

An interface may also be provided for communication between the disk drive and a host (integral or external) to send and receive the data and for controlling the operation of the disk drive and communicating the status of the disk drive to the host, all as will be understood by those of skill in the art.

In a typical head, an inductive write head includes a coil layer embedded in one or more insulation layers (insulation stack), the insulation stack being located between first and second pole piece layers. A gap is formed between the first and second pole piece layers by a gap layer at an air bearing surface (ABS) of the write head. The pole piece layers may be connected at a back gap. Currents are conducted through the coil layer, which produce magnetic fields in the pole pieces. The magnetic fields fringe across the gap at the ABS for the purpose of writing bits of magnetic field information in tracks on moving media, such as in circular tracks on a rotating magnetic disk.

The second pole piece layer has a pole tip portion that extends from the ABS to a flare point and a yoke portion that extends from the flare point to the back gap. The flare point is where the second pole piece begins to widen (flare) to form the yoke. The placement of the flare point directly affects the magnitude of the magnetic field produced to write information on the recording medium.

According to one illustrative embodiment, a magnetic data storage system may comprise at least one magnetic head as described herein according to any embodiment, a magnetic medium, a drive mechanism for passing the magnetic medium over the at least one magnetic head, and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

FIG. 2Aillustrates, schematically, a conventional recording medium such as used with magnetic disc recording systems, such as that shown inFIG. 1. This medium is utilized for recording magnetic impulses in or parallel to the plane of the medium itself. The recording medium, a recording disc in this instance, comprises basically a supporting substrate200of a suitable non-magnetic material such as glass, with an overlying coating202of a suitable and conventional magnetic layer.

FIG. 2Bshows the operative relationship between a conventional recording/playback head204, which may preferably be a thin film head, and a conventional recording medium, such as that ofFIG. 2A.

FIG. 2Cillustrates, schematically, the orientation of magnetic impulses substantially perpendicular to the surface of a recording medium as used with magnetic disc recording systems, such as that shown inFIG. 1. For such perpendicular recording the medium typically includes an under layer212of a material having a high magnetic permeability. This under layer212is then provided with an overlying coating214of magnetic material preferably having a high coercivity relative to the under layer212.

FIG. 2Dillustrates the operative relationship between a perpendicular head218and a recording medium. The recording medium illustrated inFIG. 2Dincludes both the high permeability under-layer212and the overlying coating214of magnetic material described with respect toFIG. 2Cabove. However, both of these layers212and214are shown applied to a suitable substrate216. Typically there is also an additional layer (not shown) called an “exchange-break” layer or “intermediate layer” between layers212and214.

In this structure, the magnetic lines of flux extending between the poles of the perpendicular head218loop into and out of the overlying coating214of the recording medium with the high permeability under layer212of the recording medium causing the lines of flux to pass through the overlying coating214in a direction generally perpendicular to the surface of the medium to record information in the overlying coating214of magnetic material preferably having a high coercivity relative to the under layer212in the form of magnetic impulses having their axes of magnetization substantially perpendicular to the surface of the medium. The flux is channeled by the soft underlying coating212back to the return layer (P1) of the head218.

FIG. 2Eillustrates a similar structure in which the substrate216carries the layers212and214on each of its two opposed sides, with suitable recording heads218positioned adjacent the outer surface of the magnetic coating214on each side of the medium, allowing for recording on each side of the medium.

FIG. 3Ais a cross-sectional view of a perpendicular magnetic head. InFIG. 3A, helical coils310and312are used to create magnetic flux in the stitch pole308, which then delivers that flux to the main pole306. Coils310indicate coils extending out from the page, while coils312indicate coils extending into the page. Stitch pole308may be recessed from the ABS318. Insulation316surrounds the coils and may provide support for some of the elements. The direction of the media travel, as indicated by the arrow to the right of the structure, moves the media past the lower return pole314first, then past the stitch pole308, main pole306, trailing shield304which may be connected to the wrap around shield (not shown), and finally past the upper return pole302. Each of these components may have a portion in contact with the ABS318. The ABS318is indicated across the right side of the structure.

Perpendicular writing is achieved by forcing flux through the stitch pole308into the main pole306and then to the surface of the disk positioned towards the ABS318.

FIG. 3Billustrates a piggyback magnetic head having similar features to the head ofFIG. 3A. Two shields304,314flank the stitch pole308and main pole306. Also sensor shields322,324are shown. The sensor326is typically positioned between the sensor shields322,324.

FIG. 4Ais a schematic diagram of one embodiment that uses looped coils410, sometimes referred to as a pancake configuration, to provide flux to the stitch pole408. The stitch pole then provides this flux to the main pole406. In this orientation, the lower return pole is optional. Insulation416surrounds the coils410, and may provide support for the stitch pole408and main pole406. The stitch pole may be recessed from the ABS418. The direction of the media travel, as indicated by the arrow to the right of the structure, moves the media past the stitch pole408, main pole406, trailing shield404that may be connected to the wrap around shield (not shown), and finally past the upper return pole402(all of which may or may not have a portion in contact with the ABS418). The ABS418is indicated across the right side of the structure. The trailing shield404may be in contact with the main pole406in some embodiments.

FIG. 4Billustrates another type of piggyback magnetic head having similar features to the head ofFIG. 4Aincluding a looped coil410, which wraps around to form a pancake coil. Also, sensor shields422,424are shown. The sensor426is typically positioned between the sensor shields422,424.

InFIGS. 3B and 4B, an optional heater is shown near the non-ABS side of the magnetic head. A heater element (Heater) may also be included in the magnetic heads shown inFIGS. 3A and 4A. The position of this heater may vary based on design parameters such as where the protrusion is desired, coefficients of thermal expansion of the surrounding layers, etc.

Perpendicular magnetic recording methods are being developed and implemented to replace conventional in-plane magnetic recording methods as the preferred recording method of a magnetic head slider for higher density recording on HDDs as described previously. Because the perpendicular magnetic recording method has a narrower tip on the write element to concentrate magnetic flux, and the magnetic recording width on the magnetic disk changes in response to the element height of the narrowed tip, forming the element height of the write element with high precision becomes a problem when attempting to improve the yield. A conventional technique contributed to raising the yield to a high level by measuring the resistances of the resistance detecting elements formed on the same plane in the vicinities of the read element and the write element of the magnetic head slider during the polishing step of the air bearing surface of the magnetic head slider, and correcting the position offset precision of the read element and the write element to a high degree of precision followed by processing. However, the precision of the position offset detection for the conventional read element and write element must be further improved to about 10 nm.

One advantage of embodiments described herein is to solve the problem described above and to provide a magnetic head slider capable of detecting the position offsets of the read element and write element with high precision in the ABS finishing process of the magnetic head slider, and a method for manufacturing the slider.

To achieve the above advantage, a magnetic head slider in one embodiment may have at least three resistance detecting elements in the short axis direction of the magnetic head slider. In addition, one of the resistance detecting elements is the resistance detecting element formed to calculate the element height of the read element. The remaining two resistance detecting elements are the resistance detecting elements formed to calculate the element height of the write element. Furthermore, one of the resistance detecting elements for detecting the element height of the write element is formed near the write upper shield or is replaced by a flying height detecting element. In addition, in order to measure the resistance of each resistance detecting element described above, gold terminals for resistance detection which are connected to each element are formed at the end surface of the magnetic head.

A method for manufacturing a magnetic head, according to one embodiment, comprises the following steps. Of course, more or less steps may be included in the method, according to various embodiments.

1) A step for forming a read element, a write element, a write upper shield, a heating element; a resistance detecting element near the read element, a resistance detecting element near the write element, a resistance detecting element near the write upper shield element, and a flying height detecting element on a wafer. The flying height detecting element includes a base material comprising Al2O3—TiC.

2) A step for forming terminals for the read element, for the write element, for the write upper shield, for the heating element, for the resistance detecting element near the read element, for the resistance detecting element near the write element, for the resistance detecting element near the write upper shield element, and for the flying height detecting element. The terminals may comprise any suitable material, such as gold, silver, platinum, copper, etc.

3) A step for cutting the wafer into row bars that connect more than ten magnetic heads together.

4) A step for polishing the ABS while a polishing jig holding a row bar is tilted in the direction of a short axis of the row bar so that the offsets of the read element and the write element are at a specified offset by using the element height information calculated from the resistance value of each resistance detecting element when the resistances of at least three resistance detecting elements are measured.

5) A step for forming an ABS rail on the surface which becomes the ABS of the magnetic head in order to aid the magnetic head in flying above a magnetic disk.

6) A step for dividing a row bar into individual magnetic heads.

Some embodiments may be applied to a magnetic head to improve the precision of the formation of the write element height and improve the electrical characteristic yield because the offset detection precision is improved over a conventional read element and write element.

FIG. 6Ais a schematic view of a magnetic head according to the prior art.FIG. 6Bis a cross-sectional view of a magnetic head according to the prior art.FIG. 6Cis an enlarged view of an element member from the ABS of the magnetic head according to the prior art. As shown inFIG. 6A, the magnetic head is formed from a substrate4and a protective film12embedded with each element, which is explained in more detail later. In addition, an ABS rail24is formed by ion milling on the ABS so that the magnetic head in the HDD flies on the order of nanometers above the ABS, which is a surface of the magnetic head3that is opposite the magnetic disk. Gold terminals13-23are formed in the end surface of the magnetic head in order to measure the resistance value of each element embedded in the protective film12. As shown inFIG. 6BandFIG. 6C, the magnetic head3comprises the read element5, write element6, write upper shield7, heating element8, and flying height detecting element9formed on the end surface of the substrate4, which comprises Al2O3—TiC. In addition, the resistance detecting elements10and11used in the ABS finishing step are formed near the read element5and the write element6. The protective film12which comprises alumina (e.g., Al2O3) is formed in order to protect all of the elements of the magnetic head3. Each element is connected to a pair of gold terminals13-23. The gold terminals for the read element5are13and14. The gold terminals for the write element6are15and16. The gold terminals for the heating element8are17and18. The gold terminals for the resistance detecting element10near the read element are19and20. The gold terminals for the resistance detecting element11near the write element are19and21. The gold terminals for the flying height detecting element9are22and23.

With continued reference toFIGS. 6A-6C, in the conventional technology, a method for manufacturing a magnetic head includes the following steps.

1) A read element5, a write element6, a write upper shield7, a heating element8, a flying height detecting element9, a resistance detecting element10near the read element5, and a resistance detecting element11near the write element6are formed on a substrate4that has about a 5-inch diameter and typically comprises Al2O3—TiC by using a thin-film process, such as plating, sputtering, polishing, etc.

2) The protective film12, which typically comprises alumina, is formed by sputtering to cover the elements described above.

3) Optionally, through holes may be formed in the protective film12. The protective film may have the through holes formed therethrough for allowing coupling of the terminals to the write element, the read element, the first resistance detecting element, the second resistance detecting element, and the third resistance detecting element. Each element and the gold terminals may be connected by at least one of Au, Ag, Cu, NiFe, etc., using the through holes or some other path of connection.

4) The substrate4is cut into row bars that align several tens of magnetic heads by using a cutting process, such as by using a cutting wheel.

5) A process is conducted to coarsely polish the ABS of the row bar which is the surface opposite the magnetic disk. This step determines the offsets of the read element5and the write element6in the direction opposite the magnetic disk. Specifically, gold terminals19and20for the resistance detecting element10near the read element5and the gold terminals19and21for the resistance detecting element11near the write element6are connected to the resistance detecting board of a polishing device by extremely fine gold wires having a diameter of about 30 μm. During the polishing process, after the resistance value of the resistance detecting element10near the read element and the resistance value of the resistance detecting element11near the write element were measured in the process, and the resistance value was converted to the respective element height, the offsets of the read element5and the write element6are calculated. Polishing is conducted by providing the angle in the direction of the short axis of the row bar so that the average value of the offsets of the read element5and the write element6of each detection slider in the row bar becomes the desired offset.

6) A final finishing and polishing process is applied to the ABS, which is the surface of the row bar opposite the magnetic disk. This step determines the element height of the read element5. Specifically, the gold terminals19and20of the resistance detecting element10for the read element5are connected by extremely fine gold wires having a diameter of 30 gm to the resistance detecting board of the polishing device. During the polishing process, after the resistance of the resistance detecting element10is measured in the process, and the resistance value is converted to the element height, the polishing pressure applied to the row bar is partially controlled so that the element height of each element in a row bar becomes constant.

7) An ABS rail24is formed by ion milling on the ABS of the row bar in order for the magnetic head in the HDD to fly on the order of nanometers above the surface.

8) A cutting process is used to divide the row bar into individual magnetic heads.

Next, a first embodiment is explained with reference toFIGS. 7A-7C. As shown, similar to conventional methods and technology, the read element5and the resistance detecting element10near the read element5are formed on the same plane, the write element6and the resistance detecting element11near the write element6are formed on the same plane, the write upper shield7and the resistance detecting element25near the write upper shield7are formed on the same plane, the heating element8, and the flying height detecting element9are stacked in the element part on the side surfaces of the magnetic head.

In one embodiment, each element is connected to the gold terminals13-23and26on the side surfaces of the magnetic head by wires, possibly utilizing the through holes. According to the first embodiment, as shown inFIG. 7A, the read element5is connected to terminals13and14, which may comprise gold, silver, platinum, copper, etc., as would be known to one of skill in the art. Throughout this description, the terminals are described as gold, but this in no way limits the terminals from comprising a different suitable material, in addition to or in place of gold. The write element6is connected to gold terminals15and16. The heating element8is connected to gold terminals17and18. The resistance detecting element10for the read element5is connected to gold terminals19and20. The resistance detecting element11for the write element6is connected to gold terminals19and21. The flying height detecting element9is connected to gold terminals22and23. The resistance detecting element11of the write upper shield7is connected to gold terminals19and26.

In addition, as shown inFIG. 7C, in one embodiment, the resistance detecting element11near the write element6and the resistance detecting element25near the write upper shield7are arranged on the same side with respect to the read element5and the write element6. Furthermore, in one approach, the distance between the read element5and the resistance detecting element10near the read element5, the distance between the write element6and the resistance detecting element11near the write element6, and the distance between the write upper shield7and the resistance detecting element25near the write upper shield7are desired to be as short as possible.

Now referring toFIG. 8, a method800for forming a magnetic head is shown according to one embodiment. The method800may be carried out in any desired environment, and may include more or less operations than those described herein, according to various embodiments. The method800will be described with respect to elements shown inFIGS. 7A-7C, which together withFIG. 8help to describe the method800.

In operation802, a read element5, a write element6, a write upper shield7, a heating element8, a flying height detecting element9, a resistance detecting element10near the read element5, a resistance detecting element11near the write element6, and a resistance detecting element25near the write upper shield7are formed in sequence on a substrate4that has about a 5-inch diameter and comprises a suitable material as would be known to one of skill in the art, such as Al2O3—TiC, possibly through a thin-film process, such as plating, sputtering, polishing, etc.

In operation804, a protective film12is formed, possibly using sputtering, to completely cover the read element5, write element6, write upper shield7, heating element8, flying height detecting element9, resistance detecting element10near the read element5, resistance detecting element11near the write element6, and resistance detecting element25near the write upper shield7. The protective film12, according to one approach, may comprise alumina or any other suitable material, as would be understood by one of skill in the art.

In optional operation806, through holes may be formed in the protective film12, through which each element and the gold terminals may be connected by a suitable conductive material, such as gold, silver, copper, NiFe, platinum, etc., as would be known by one of skill in the art.

In operation808, the substrate4is cut into row bars for aligning several tens of magnetic heads, such as by using a cutting process and a cutting wheel, in one approach. Of course, any other suitable method may be used, as would be known to one of skill in the art.

In operation810, a process is conducted to coarsely polish the ABS of the row bar, which is the surface opposite the magnetic disk. This operation determines the offsets of the read element5and the write element6in the direction opposite the magnetic disk. Specifically, gold terminals19and20for the resistance detecting element10near the read element5, the gold terminals19and21for the resistance detecting element11near the write element6, and the gold terminals19and26for the resistance detecting element25near the write upper shield7are connected to the resistance detecting board of the polishing device by fine gold wires or other suitable conductors. Each wire may have a diameter of about 30 μm, in one approach.

During the polishing process, after the resistance values of the resistance detecting elements10,11, and25are measured in the process, and the resistance value is converted to a respective element height, the offsets of the read element5and the write element6may be calculated using a calculation method, which is described later. The polishing is conducted by providing the angle in the direction of the short axis of the row bar so that the average value of the offsets of the read element5and the write element6of each detection slider in the row bar becomes the desired offset.

In operation812, a final finishing and polishing process is applied to the ABS. This operation determines the element height of the read element5. Specifically, the gold terminals19and20of the resistance detecting element10for the read element5are connected, such as by using extremely fine gold wires, each wire having a diameter of 30 μm in one approach, to the resistance detecting board of the polishing device. During the polishing process, after the resistance of the resistance detecting element10,11, and25is measured in the process, and the resistance value is converted into an element height, the polishing pressure applied to the row bar is partially controlled so that the element height of each element of the row bar is made to be constant.

In operation814, an ABS rail24is formed, such as through ion milling in one approach, on the ABS of the row bar in order for the magnetic head in the HDD to fly at a distance of several nanometers above the magnetic disk.

In operation816, a cutting process is used to divide the row bar into individual magnetic head sliders.

In operation808, the offset error between the read element5and the write element6are detected.

As shown inFIG. 9, the angle α may be given in the direction of the short axis of the row bar and is corrected, in one approach, based on the offset error determined between the read element5and the write element6, in one approach.

Referring again toFIGS. 7A-7C, in the conventional technology, the offsets of the read element5and the write element6are determined by the following method. The resistance value-element height conversion coefficients determined in advance from the resistance value of the resistance detecting element10near the read element5and the resistance value of the resistance detecting element11near the write element6, which were measured in process, are used to convert each resistance value to an element height. The difference between the values is calculated as the offset error. In the first embodiment, similar to the conventional technology, in addition to the offset error as calculated from the resistance values of the resistance detecting element10and the resistance detecting element11, a new offset error b is calculated from the difference between the element height calculated from the resistance value of the resistance detecting element25formed near the write upper shield7and the element height calculated from the resistance detecting element10. In this embodiment, when the read element5is set as the origin, the write element6is formed at a position separated by about 5200 nm in the direction of the film thickness. The write upper shield7is formed at a position separated by about 7200 nm. Of course, other dimensions may be used, as would be understood by one of skill in the art, which may depend on size, structure, function, etc., of the magnetic head.

As shown inFIG. 10, a distance from the read element is plotted on the horizontal axis, and the offset errors a and b are plotted on the vertical axis. The offset error at 5200 nm, which is the write element position, is calculated from the approximate line calculated by the method of least squares, in one approach. Other suitable methods of calculating the write element position may also be used, as would be understood by one of skill in the art.

Referring again toFIGS. 7A-7C, by calculating one offset error from the resistance detecting elements at three locations, the offset calculation precision is improved over the conventional technology that calculates the offset error from the resistance detecting elements at two locations. In this embodiment, the offset error of the write element6is calculated by the method of least squares. However, the average value of the correction angle determined from the offset errors of the resistance detecting element10and the resistance detecting element11, the correction angle determined from the offset errors of the resistance detecting element10and the resistance detecting element25, and the correction angle determined from the offset errors of the resistance detecting element11and the resistance detecting element25may be calculated as the control angle.

In a second embodiment, a method uses the flying height detecting element9in the calculation of the offset error instead of the resistance detecting element25described in the first embodiment.FIGS. 11A-11Cshow the details of the magnetic head, according to the second embodiment. As shown inFIGS. 11B-11C, similar to the conventional technology, the magnetic head3comprises a read element5, a write element6, a write upper shield7, a heating element8, a flying height detecting element9formed on the end surface of the substrate4. The substrate may comprise Al2O3—TiC, in one approach.

The resistance detecting elements10and11used in the ABS polishing step may be formed near the read element5and the write element6. As shown inFIG. 11A, read element5is connected to gold terminals13and14. Write element6is connected to gold terminals15and16. Heating element8is connected to gold terminals17and18. Resistance detecting element10for the read element is connected to gold terminals19and20. Resistance detecting element11for the write element is connected to gold terminals19and21. Flying height detecting element9is connected to gold terminals22and23and gold terminals19and27. The gold terminals19and27for use by the flying height detecting element9are the locations connected by extremely fine gold wires in order to measure the resistance of the flying height detecting element9in the ABS polishing step. If there are no problems in the process even when the gold wires are connected to the gold terminals22and23, the flying height detecting element9and the gold terminals19,27do not have to be wired.

A manufacturing method for forming a magnetic head, according to the second embodiment, is substantially the same as the method800as described inFIG. 8for the first embodiment. Referring again toFIGS. 11A-11C, the calculation method of the offset error of the write element6is nearly identical to that in the first embodiment. Specifically, in addition to the offset error as calculated from the resistance values of the resistance detecting element10and the resistance detecting element11, a new offset error b is calculated from the difference between the element height calculated from the resistance value of the flying height detecting element9and the element height calculated from the resistance detecting element10. In this embodiment, when the read element5is assumed to be the origin, the write element6is formed at a position separated by 5200 nm in the direction of the film thickness. The flying height detecting element9is formed at a position separated by about 4200 nm in one approach. Of course other dimensions may be used, as would be known to one of skill in the art depending on the size, function, etc. of the magnetic head, such as 3800 nm, 4000 nm, 4500 nm, 4800 nm, 5500 nm, etc.

Similar toFIG. 9, with reference toFIGS. 11A-11C, the distance from the read element5is plotted on the horizontal axis. The offset errors a, b are plotted on the vertical axis. The offset error at 5200 nm, which is the write element position, is calculated from the approximate line calculated by the least squares method. Similar to the first embodiment, the average of the correction angle determined from the offset error of the resistance detecting element10and the resistance detecting element11, the correction angle determined from the offset error of the resistance detecting element10and the flying height detecting element9, and the correction angle determined from the offset error of the resistance detecting element11and the flying height detecting element9may be calculated as the control angle.

FIG. 12is a graph showing the fluctuations in the offset error determined from the approximate lines of the conventional technology, the first embodiment, and the second embodiment. When the resistance detecting element25formed in the same layer as the write upper shield described in the first embodiment is used to calculate the offset error, the calculation precision is improved from 9.1 nm to 5.4 nm. In addition, when the flying height detecting element9described in the second embodiment is used to calculate the offset error, the calculation precision is improved from 9.1 nm to 7.2 nm. By improving the precision, the fluctuations (σ) of the MCW decrease to 4 nm in the first embodiment and to 2 nm in the second embodiment.

Although the first and second embodiments have been described with some particularity herein, modifications, additional approaches, and/or adjustments may be made to either embodiment without varying the effectiveness of the magnetic head, as described herein.