KR20090024400A - Perpendicular magnetic recording head, magnetic recording apparatus employing the same, and magnetic recording method of matching magnetic writing track width - Google Patents

Abstract

A vertical magnetic recording head is provided to reduce magnetic interaction between adjacent data tracks of discrete magnetic track media or pattern media and implement high track density by controlling the width of a magnetic record track of the vertical magnetic recording head. A vertical magnetic recording head comprises: a main pole(151) in which the width of a recording medium side end part becomes narrow towards a recording medium; a return yoke of which a magnetic path is made with the main pole; and a coil inducing the magnetic field for magnetic recording in the main pole. The width of a magnetic record track formed in the recording medium with the magnetic field emitted in the vertical magnetic recording head is controlled by the size of recording current which is input to the coil.

Description

Perpendicular magnetic recording head, magnetic recording apparatus employing the same, and magnetic recording method of matching magnetic writing track width}

The present invention relates to a vertical magnetic recording head, a magnetic recording apparatus employing the same, and a magnetic recording method for matching the magnetic recording track width. More particularly, the width of the magnetic recording track by adjusting the intensity of the recording current. The present invention relates to a vertical magnetic recording head capable of adjusting a magnetic writing track width, a magnetic recording apparatus employing the same, and a magnetic recording method for matching a magnetic recording track width.

There is a demand for an information storage device capable of recording / reproducing data at a higher density due to the rapid increase in the amount of information data processed today. In particular, a magnetic recording apparatus using a recording medium is attracting attention as an information storage apparatus not only for a computer but also for various digital apparatuses because of its large capacity and fast characteristics.

Magnetic recording of such a magnetic recording apparatus can be largely divided into a horizontal magnetic recording method and a vertical magnetic recording method according to the recording method. The horizontal magnetic recording method records data by using the magnetization direction of the magnetic layer aligned parallel to the surface of the magnetic layer, and the vertical magnetic recording method uses the magnetization direction of the magnetic layer aligned vertically with the surface of the magnetic layer. This is a method of recording data. In terms of recording density, the vertical magnetic recording method is much more advantageous than the horizontal magnetic recording method, so that a vertical magnetic recording head having various structures has been developed.

On the other hand, thanks to the development of the vertical magnetic recording head, the recording density of the hard disk drive has recently recorded an improvement of 30-40% annually, and the current recording density of about 1200kBPI has been achieved at the mass production level, and has been steadily increasing. It is anticipated that the prerecorded density level of 1500kBPI will be reached in the next 1-2 years. However, in the case of a conventional recording medium having a continuous magnetic recording layer (hereinafter, referred to as continuous media), if the size of the bit or the pitch of the data track, which is the minimum recording unit of data, is reduced to a certain limit or less, an adjacent area is used. Due to the influence of noise, the noise becomes severe and recording stability drops sharply. Therefore, the linear recording density (BPI), which is the density of the disc rotation direction, or the track density (TPI), which is the density of the disk radial direction, is increased. There is a limit to increasing the density. Accordingly, discrete track media or pattern media in which magnetic recording positions in the magnetic recording layer are patterned in advance in a manufacturing step have been proposed. The discrete track medium has a structure in which an annular data track is patterned in advance, and the pattern medium has a structure in which bits, which are the minimum recording units, are patterned in an island shape. At this time, the separation region between the patterned data tracks or around the patterned unit bits is left blank or filled with a nonmagnetic material. In the case of such discrete track media and pattern media, by minimizing the interference between adjacent data tracks, it is possible to increase the track density and record the data at high density.

FIG. 1 is a view showing a vertical magnetic recording head 10 according to the prior art, and FIG. 2 is a sectional view of the recording width along the line II in FIG. Referring to FIG. 1, the conventional vertical magnetic recording head 10 includes a recording head portion having a main pole 11, a return yoke 13, a sub yoke 15, and a coil 14 and two magnetic shield layers. And a reproducing head portion having a magnetoresistive element 18 interposed between the magnetic shield layer 19 and the magnetic shield layer 19. When a current is applied to the coil 14, the main pole 11, the return yoke 13, and the sub yoke 15 form a magnetic path of the magnetic field. The magnetic field from the main pole 11 toward the recording medium (not shown) forms a path back to the return yoke 13 after magnetizing the recording layer of the recording medium in the vertical direction, thereby performing recording. Meanwhile, referring to FIG. 2, the recording pole 12 is a magnetic thin film composed of a pole tip 12a, a pole neck 12b, and a pole body 12c. The width W _p is made constant. In the course of the magnetic recording head 10, since the end of the pole tip 12a is thinned by lapping, the width of the pole tip 12a is constant so that the width of the pole tip 12a is changed by lapping. Serves to prevent this from happening.

However, the width of the pole tip 12a varies slightly depending on manufacturing tolerances, and the vertical magnetic recording head of the conventional pole tip 12a structure is difficult to adjust the width of the magnetic recording track formed by the emitted magnetic field. However, in discrete track media or pattern media, problems may not occur in continuous media. For example, when the width of the magnetic recording track formed by the magnetic field emitted from the vertical magnetic recording head is wider than the width of the patterned data track of the recording medium, the bit error rate is lowered by violating neighboring data tracks. Problems may occur, which may be a barrier to realizing higher track density by reducing magnetic interference of adjacent data tracks. Further, if the width of the patterned data track of the recording medium does not match the width of the magnetic recording track of the magnetic recording head during assembly of the magnetic recording apparatus, a large amount of defects may occur.

The present invention has been made to solve the problems of the conventional vertical magnetic recording head, the magnetic recording apparatus employing the same, and the magnetic recording method for matching the magnetic recording track width. A vertical magnetic recording head capable of easily matching the width of a magnetic recording track to a recording medium having a predetermined width at the manufacturing stage such as a discrete track medium or a pattern medium by improving the structure, a magnetic recording apparatus employing the same; And a magnetic recording method for matching the magnetic recording track width.

In order to achieve the above object, the vertical magnetic recording head according to the present invention comprises: a main pole which magnetically records data on a recording medium, the width of the end of the recording medium being narrower toward the recording medium; A return yoke constituting a jaw with the main pole; And a coil for inducing a magnetic recording magnetic field in the main pole, wherein a width of a magnetic recording track formed on the recording medium by a magnetic field emitted from the vertical magnetic recording head is inputted to the coil. It is characterized by being controlled by.

In addition, in order to achieve the above object, the magnetic recording apparatus according to the present invention comprises a recording medium whose width of the data track is predetermined in the manufacturing step; A vertical magnetic recording head having a main pole whose width of an end portion of the recording medium becomes narrower toward the recording medium, a return yoke forming a magnetic path together with the main pole, and a coil for inducing a magnetic recording magnetic field in the main pole; And a recording current input to the coil such that the width of the magnetic recording track formed on the recording medium by the magnetic field emitted from the vertical magnetic recording head matches the width of the predetermined data track on the recording medium. The width of the magnetic recording track is determined by the intensity.

In addition, in order to achieve the above object, the magnetic recording method according to the present invention includes a main pole in which the width of the end of the recording medium becomes narrower toward the recording medium, the width of the data track is predetermined in the manufacturing step, A method of magnetic recording data using a vertical magnetic recording head having a return yoke forming a magnetic path with a main pole and a coil inducing a magnetic recording magnetic field in the main pole, the magnetic field emitted from the vertical magnetic recording head. Determining the width of the magnetic recording track by adjusting the magnitude of the recording current input to the coil so that the width of the magnetic recording track formed on the recording medium is matched with the width of a predetermined data track on the recording medium. Making; And magnetically recording data in the width of the determined magnetic recording track.

The vertical magnetic recording head and the magnetic recording apparatus employing the same according to the present invention by the problem solving means as described above

First, the width of the magnetic recording track formed by the recording magnetic field emitted from the vertical magnetic recording head can be easily adjusted.

Second, as the width of the magnetic recording track of the vertical magnetic recording head can be adjusted to match the width of the pre-patterned data track during manufacturing, such as discrete track media or pattern media, the recording medium and the vertical magnetic recording head are assembled. Tolerances allowed in the process are alleviated, and the manufacturing process becomes easy.

Third, by adjusting the width of the magnetic recording track of the vertical magnetic recording head, it is possible to realize higher track density by reducing magnetic interference between adjacent data tracks of the discrete track media or the pattern media.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the examples exemplified below are not intended to limit the scope of the present invention, but are provided to fully explain the present invention to those skilled in the art. In the drawings, like reference numerals refer to like elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of description.

3 to 7, a vertical magnetic recording head and a magnetic recording apparatus employing the same according to an embodiment of the present invention will be described.

3 schematically shows a magnetic recording apparatus according to an embodiment of the present invention, FIG. 4 is a cross-sectional view schematically showing the structure of a vertical magnetic recording head according to an embodiment of the present invention, and FIG. This is a cross-sectional view of the main pole along the line II-II. 6 and 7 are enlarged partial cross-sectional perspective views showing one area A of the recording medium of FIG. 3, FIG. 6 shows a case where the recording medium is a discrete track medium, and FIG. 7 shows a case where the recording medium is a pattern medium. Shows.

Referring to FIG. 3, the magnetic recording apparatus 100 of the present invention includes an actuator 120 in which a recording medium 110 and a vertical magnetic recording head 150 of FIG. 4 are magnetically recorded on the magnetic recording medium 110. It includes.

The actuator 120 includes an actuator arm 125 and a suspension 123 provided at an extended position thereof, and a slider 121 having a vertical magnetic recording head 150 is attached to an end of the suspension 123. And a configuration driven by a voice coil motor (VCM) 127.

4 and 5, the vertical magnetic recording head 150 attached to the slitter (121 of FIG. 3) emits a magnetic field toward the recording medium 110 in order to record data on the recording medium 110. A recording head including a main pole 151, a coil 154 to which an electric current for generating an induced magnetic field is applied, and a return yoke 153 which forms a magnetic path of the magnetic field together with the main pole 151. Part (W) is included. The recording head unit W may further include a sub yoke 155 to help the magnetic flux to be concentrated at the end of the recording medium 110 side of the main pole 151. Also, in order to read the data recorded on the recording medium 110, a reproduction head portion R made up of two magnetic shield layers 159 and a magnetoresistive element 158 interposed between the magnetic shield layers 159 is provided. It may further include. The magnetoresistive element 158 reads the data recorded on the recording medium 110 by exhibiting a characteristic of changing the electrical resistance due to the magnetic field signal generated from the magnetization of the recording medium 110.

The main pole 151, the return yoke 153 and the sub yoke 155 are made of a magnetic material to form a magnetic path of the recording magnetic field generated by the coil 154. At this time, the size of the magnetic field focused on the recording medium 110 end of the main pole 151 is limited by the saturation magnetic flux density of the main pole 151, the main pole 151 has a saturation magnetic flux density of the return yoke 153 ) Or a magnetic material larger than the sub yoke 155. For example, NiFe, CoFe, CoNiFe, or the like may be employed. Preferably, the sub yoke 155 or the return yoke 153 has a higher magnetic permeability than the main pole 151 so as to have a fast response to a high frequency magnetic field change. Magnetic materials such as nickel iron (NiFe) are mainly used, and the saturation magnetic flux density and permeability are appropriately designed by adjusting the component ratio of Ni and Fe.

The end of the recording medium 110 side of the return yoke 153 is formed to be spaced apart from the pole tip (151a of FIG. 5) of the main pole 151. At this time, the gap between the end of the return yoke 153 and the pole tip 151a is appropriately determined so that the magnetic field emerging from the pole tip 151a may form a return path after magnetizing the recording medium 110 in the vertical direction. do. For example, the gap between the end of the return yoke 153 and the pole tip 151a of the main pole 132 may be formed to be about several hundred nm or less.

The sub yoke 155 focuses a magnetic field on the pole tip 151a of the main pole 151, and is a predetermined distance from the pole tip 151a at a position in contact with a surface facing the return yoke 153 of the main pole 151. It may be formed spaced apart. One side of the sub yoke 155 and the return yoke 153 are magnetically joined to form a passage to a ruler. The sub yoke 155 may be formed on a rear surface of the main pole 151 that faces the return yoke 153.

The coil 154 inducing a magnetic field to the main pole 151 may be formed as a solenoid type or a spiral type as shown.

Referring to FIG. 5, the recording pole 151 is formed of a magnetic thin film composed of a pole tip 151a and a pole body 151b. Here, the pole tip 151a is narrower from the pole body 151b toward the recording medium, so that the first width W _p1 on the recording medium side is larger than the second width W _p2 on the side of the pole body 151b. It is formed to be small. The first width W _p1 of the pole tip 151a may be, for example, a size of several nm to several hundred nm. When the recording current flows, the magnetic field emitted through the pole tip 151a causes magnetic recording on the recording medium (110 in FIG. 3), and the magnetic recording track records the magnetic recording track as the recording medium 110 rotates. (T _{MW in} FIG. 3) is formed. The width of the magnetic recording track T _MW is determined by the pole tip 151a and the magnitude of the recording current. Although the first width W _p1 of the pole tip 151a slightly varies with the design value due to manufacturing tolerances, the width of the magnetic recording track T _{MW of the} present embodiment adjusts the magnitude of the recording current as described later. Can be adjusted.

The recording medium 110 may be formed in a disk shape and may be magnetically recorded with a magnetic layer (not shown). The recording medium 110 may be a discrete track medium or a pattern medium. 6 and 7 are enlarged partial cross-sectional perspective views showing the area A of the recording medium of FIG. 3, FIG. 6 shows a case where the recording medium is a discrete track medium, and FIG. 7 shows a case where the recording medium is a pattern medium. do.

Referring to FIG. 6, in the recording medium 110, the magnetic layer 112 formed on the substrate 111 is patterned in units of a data track 113, and a portion of the data track 113 protrudes, and the data track 113 is formed. The separation region 114 between the two holes may be a discrete track medium configured to be empty or filled with a nonmagnetic material so that only the data track 113 can be magnetically recorded. Referring to FIG. 7, in the recording medium 110, the magnetic layer 115 formed on the substrate 111 is patterned in units of bit dots 116 so that a portion of the bit dots 116 protrudes and the bit dots are formed. The isolation region 117 between the 116 portions may be a pattern medium configured to be empty or filled with a nonmagnetic material so that only the bit dots 116 can be magnetically recorded. At this time, the columns of the bit dots 116 form a data track 113 ', and the width W _T of the data track 113' is already determined at the manufacturing stage. Such discrete track media or pattern media are well known in the art, and thus detailed descriptions thereof will be omitted. In the case of the discrete track medium or the pattern medium, the width W _T of the data track (113 in FIG. 6 and 113 'in FIG. 7) has already been determined at the manufacturing stage, but the vertical magnetic recording head 150 will be described later. By appropriately adjusting the write current input to the N, the width W _T of the data tracks 113 and 113 'can be matched to the width of the magnetic write track T _MW .

8 is a graph showing the intensity of an electric field applied to the recording medium in the track width direction according to the intensity of the recording current input to the vertical magnetic recording head of this embodiment. Referring to FIG. 8, when the effective vertical magnetic field intensity that can change the magnetization direction of the signal recorded on the recording medium is 1 T, the recording current applied to the vertical magnetic recording head is increased from 15 mA to 30 mA. In this case, it can be seen that the width of the signal recorded on the recording medium, that is, the width of the magnetic recording track increases by more than 50% from 0.11 μm to 0.17 μm. That is, FIG. 8 shows that by adjusting the recording current, the width of the magnetic recording track formed by the magnetic field emitted from the vertical magnetic recording head can be changed.

The pole tip 151a of FIG. 5 has a trapezoidal shape, but is not limited thereto. 9 and 10 show a modification of the pole tip that can be applied to the vertical magnetic recording head of the present invention. The present modifications are only the shape of the pole tip, other components are substantially the same as the above-described embodiment.

Referring to FIG. 9, the recording pole 161 may include a triangular pole tip 161a and a pole body 161b. At this time, the width of the pole tip 161a decreases toward the recording medium from the pole body 161b, so that the end of the pole tip 161a is formed smoothly.

In addition, referring to FIG. 10, the recording pole 171 may include a trapezoidal first and second pole tips 171a and 171b and a pole body 171b. Each of the first and second pole tips 171a and 171b has a trapezoidal shape whose width decreases from the pole body 171c toward the recording medium, and the rate of change and the second pole tip (171a) decrease in the width of the first pole tip 171a. The rate of change in which the width of 171b is reduced is different from each other. At this time, the second pole tip 171b has a wide width of a portion connected to the pole body 171c, so that the magnetic field induced by the pole body 171c can be better focused on the first pole tip 171a. . This modification is a case where the pole tip is composed of two stages, not limited to this, the pole tip may be formed in two or more stages.

Next, a magnetic recording method according to an embodiment of the present invention will be described. FIG. 11 is a diagram showing a relationship between a data track of a recording medium and a width of a magnetic recording track of a vertical magnetic recording head. FIG. 12 is a flowchart of a magnetic recording method according to an embodiment of the present invention.

Referring to FIG. 11, when the recording medium is a discrete track medium as shown in FIG. 6, the width of the magnetic recording track of the vertical magnetic recording head may vary in size with respect to the width W _T of the data track 113. Can have For example, when the magnetic recording track has a width W _M1 approximately equal to the width W _T of the data track 113, the magnetic recording track recorded by the vertical magnetic recording head is the data track 113. In accordance with, the data track 113 is sufficiently magnetized, and the interference in the neighboring data track 113 can also be suppressed by the isolation region 114. On the other hand, when the magnetic recording track has a width W _{M2 that} is much larger than the width W _T of the data track 113, the magnetic recording track recorded by the vertical magnetic recording head is adjacent to the data track 113. Noise may be generated by the neighboring data tracks 113 so that the bit error rate can be increased, and the bit error rate can be greatly increased even by a slight off-track of the vertical magnetic recording head. Further, when the magnetic recording track has a width W _{M3 that} is much smaller than the width W _T of the data track 113, the vertical magnetic recording head does not sufficiently magnetize the data track 113, so that the reproduction signal is not. Weakening and noise may become severe, resulting in an increase in bit error rate. Therefore, by detecting the bit error rate with respect to the widths of the various magnetic recording tracks, it is possible to determine the widths of the magnetic recording tracks matching the widths of the data tracks 113 of the recording medium.

Thus, in the magnetic recording method of the present embodiment, first, while the recording current is varied (S100), pre-data recording is performed (S110). At this time, by varying the recording current, the width of the magnetic recording track on which free data is recorded is changed. Next, by reproducing the recorded predata, the bit error rate of the reproduction signal is detected (S120). The detected bit error rate is compared to determine the free data having the minimum bit error rate (S130). As described with reference to FIG. 11, the magnetic recording track in the region in which the pre-data having the minimum bit error rate is recorded can be determined that the width is well matched with the width of the data track. If the pre data with the minimum bit error rate is not determined, the process returns to step S100 again, and the steps S100 to S130 are repeated by changing the variable width of the write current. From the free data at which the determined bit error rate is minimum, the recording current at the time of recording the same is found, the width of the magnetic recording track is determined (S140), and the data is recorded at the width of the determined magnetic recording track (S150). .

According to such a magnetic recording method, when the width of the data track is determined at the manufacturing stage when the recording medium is a discrete track medium or a pattern medium, the bit error rate can be adjusted by adjusting the width of the magnetic recording track. You can lower it to the minimum. In addition, as the data tracks of the vertical magnetic recording head and the recording medium are easily matched in this way, the assembly margin can be more afforded in the assembling process of combining the vertical magnetic recording head and the discrete track medium of the present invention.

Such a vertical magnetic recording head of the present invention, a magnetic recording apparatus employing the same, and a magnetic recording method for matching the magnetic recording track width have been described with reference to the embodiments shown in the drawings for clarity, but this is merely illustrative. Those skilled in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

1 is a sectional view schematically showing the structure of a conventional vertical magnetic recording head.

FIG. 2 is a cross-sectional view of the main pole along the line I-I of FIG. 1.

3 is a view showing a schematic structure of a magnetic recording apparatus according to an embodiment of the present invention.

4 is a cross-sectional view schematically showing the structure of a vertical magnetic recording head according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of the main pole viewed along line II-II of FIG. 4.

6 is an enlarged partial cross-sectional perspective view showing one area A of the recording medium of FIG. 3, showing a case where the recording medium is a discrete track medium.

FIG. 7 is an enlarged partial sectional perspective view showing one area A of the recording medium of FIG. 3, and FIG. 7 shows a case where the recording medium is a pattern medium.

FIG. 8 is a graph showing the strength of an electric field applied to the recording medium in the track width direction according to the strength of the recording current input to the vertical magnetic recording head of FIG. 4.

9 and 10 are modifications of the main pole of FIG. 5.

FIG. 11 shows the relationship between the data track of the recording medium and the width of the magnetic recording track of the vertical magnetic recording head.

12 is a flowchart of a magnetic recording method according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100 ... magnetic recording device, 110 ... recording medium

111 ... substrate, 112, 115 ... magnetic layer

113,113 '... data track, 114 ... isolated area

120 ... actuator, 121 ... slider

123 ... suspension, 125 ... actuator arm

127 voice coil motor, 150 vertical magnetic recording head

151,161,171 ... Main Fall, 151a, 161a, 171a, 171b ... Paul Tip

151b, 161b, 171c ... Polar Body, 153 ... Return York

154 Coil, 155 Sub York

158 Magnetoresistive element, 159 Magnet shield layer

W ... Magnetic recorder, R ... Magnetic regenerator

W _P1 , W _P2 , W _{P1 ′} , W _{P2 ′} , W _{P3 ′} ... width of pole tip, W _T ... width of data track

W _M1 , W _M2 , W _M3 ... width of magnetic recording track

Claims (9)

A vertical magnetic recording head for magnetically recording data on a recording medium, A main pole whose width of an end portion of the recording medium becomes narrower toward the recording medium; A return yoke constituting a jaw with the main pole; And a coil inducing a magnetic recording magnetic field to the main pole. And the width of the magnetic recording track formed on the recording medium by the magnetic field emitted from the vertical magnetic recording head is controlled by the magnitude of the recording current input to the coil. The method of claim 1, The main pole has a pole body and a pole tip provided at the end of the recording medium side of the pole body toward the recording medium from the pole body toward the recording medium, characterized in that the vertical magnetic recording head. The method of claim 1, And a sub yoke spaced a predetermined distance from the pole tip to focus the magnetic field on the pole tip. The method of claim 3, And the sub yoke is formed in contact with a rear surface of the pole body facing the return yoke or a surface facing the return yoke. A recording medium whose width of the data track is predetermined in the manufacturing step; And a vertical magnetic recording head according to any one of claims 1 to 4, By the magnitude of the recording current input to the coil such that the width of the magnetic recording track formed on the recording medium by the magnetic field emitted from the vertical magnetic recording head matches the width of the predetermined data track on the recording medium. And a width of the magnetic recording track is determined. The method of claim 5, And the recording medium is a discrete track medium in which a magnetic recording position is patterned in data track units or a pattern medium having a data track in which magnetic recording positions are patterned in bit units. A method of magnetically recording data using a vertical magnetic recording head of any one of claims 1 to 4 on a recording medium whose width of a data track is predetermined in a manufacturing step, By adjusting the magnitude of the recording current input to the coil so that the width of the magnetic recording track formed on the recording medium by the magnetic field emitted from the vertical magnetic recording head matches the width of the predetermined data track on the recording medium. Determining a width of the magnetic recording track; And And magnetically recording data in the width of the determined magnetic recording track. The method of claim 7, wherein Determining the magnitude of the width of the magnetic recording track, Varying a recording current on the recording medium and recording free data; Detecting a bit error rate from the recorded free data; And And determining the width of the magnetic recording track based on the recording current at which the bit error rate is minimum. The method of claim 7, wherein And the recording medium is a discrete track medium patterned in data track units or a pattern medium having a data track patterned in bit units at a magnetic recording position.

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