JP2006172691A - Magnetic head manufacturing method, magnetic head, angle setting device, and lapping device head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture, with excellent yield, a perpendicular magnetic recording type magnetic head that has a stable characteristic implementing higher recording density by considering the magnetic pole length of a recording element too when a floated surface is lapped. <P>SOLUTION: In the magnetic head manufacturing method, the floated surface of each block is ground and lapped in a grinding/lapping step. The grinding/lapping step contains an angle adjusting step for adjusting the angle of the floated surface of the block with reference to a magnetic-head-element formed surface of a substrate and grinding the floated surface concerned, and a finishing lapping step of lapping the floated surface at an angle adjusted in the angle adjusting step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a magnetic head including a recording element for writing information to a recording medium by a perpendicular magnetic recording method and a reproducing element for reading information recorded on the recording medium.

  The recording method in the magnetic recording / reproducing apparatus includes a longitudinal magnetic recording method in which the direction of signal magnetization is the in-plane direction (longitudinal direction) of the recording medium, and a direction of signal magnetization in a direction perpendicular to the surface of the recording medium. There is a perpendicular magnetic recording system. Compared to the longitudinal magnetic recording method, the perpendicular magnetic recording method is less affected by the thermal fluctuation of the recording medium and is said to be able to realize a high linear recording density, and is expected to be put into practical use in the future. ing.

Now, in the manufacturing process of a magnetic head that employs the longitudinal magnetic recording method that is currently in practical use,
(A) Step of forming a plurality of magnetic head elements including a recording element for writing information on a recording medium and a reproducing element for reading information recorded on the recording medium on the wafer substrate (b) from the wafer substrate A step of cutting the magnetic head elements into bar-shaped blocks (c), a lapping step of polishing the air bearing surface of the block, and a step of cutting the blocks into individual magnetic head elements.

Among these, in the lapping process for polishing the air bearing surface of the bar-shaped block, conventionally, the polishing amount has been set from the viewpoint of adjusting the magnetic pole length (MR height) of the reproducing element. This is because the magnetic pole length of the reproducing element has a great influence in order to reliably read the weak magnetic force recorded on the recording medium.
Specifically, using a measuring device that outputs a signal when the magnetic pole length of the reproducing element reaches an appropriate dimension, the signal from the reproducing element is observed while grinding the air bearing surface of the block, and the signal is output. At that time, the method of finishing the grinding was adopted.

  As described above, conventionally, in the lapping process, the polishing amount is set from the viewpoint of adjusting the magnetic pole length of the reproducing element, and the magnetic pole length of the recording element is not considered. This is because the longitudinal magnetic recording method has a lower recording density than the perpendicular magnetic recording method, and therefore there is little effect on the characteristics even if the magnetic pole length of the recording element is not strictly considered when lapping the air bearing surface. it is conceivable that.

However, in recent years, development of higher density has been progressing in perpendicular magnetic recording type magnetic heads with high recording density. Under such circumstances, the present inventor has intensively studied and has completed the present invention.
That is, an object of the present invention is to provide a perpendicular magnetic recording type magnetic head capable of realizing a higher recording density in consideration of the magnetic pole length of the recording element when lapping the air bearing surface.

In order to achieve the above object, according to the present invention, a plurality of magnetic head elements including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording system recording element for writing are arranged on a substrate. A process, a step of cutting the arrayed magnetic head elements into a bar-shaped block, a grinding / lapping process of grinding and lapping the air bearing surface of the block, and cutting the block into individual magnetic head elements Comprising the steps of:
The grinding / lapping process includes an angle adjustment process for adjusting the angle of the air bearing surface with respect to the block on the basis of the magnetic head element formation surface on the substrate and grinding the surface, and the air bearing surface is adjusted at an angle adjusted by the angle adjusting process. And a final lapping step of lapping.

  Here, the “floating surface” is a surface facing the recording medium, and is also referred to as ABS (Air Bearing Surface). Usually, this air bearing surface is polished by a lapping device. In the present invention, before the final lapping process, the angle of the air bearing surface is adjusted in advance (angle adjustment process), and the air bearing surface after the adjustment is polished in the lapping process.

  By adjusting the angle of the air bearing surface, each magnetic pole length of the recording element and the reproducing element can be finely adjusted and processed, and a magnetic head having stable characteristics can be manufactured with a high yield.

In the angle adjustment step, for example, it is preferable to adjust the angle of the air bearing surface with respect to the magnetic head element formation surface on the substrate based on the following factors.
(1) Variation in generation of magnetic pole length of recording element and magnetic pole length of reproducing element (2) Dimensional difference between magnetic pole length of recording element and magnetic pole length of reproducing element (3) Magnetic pole length of recording element and reproducing element Magnetic pole length dimensional difference and distance between these elements

  In any case, since the magnetic pole length of the recording element is taken into consideration in addition to the magnetic pole length of the reproducing element, it is possible to manufacture a recording head capable of realizing a higher recording density.

  Here, according to experiments by the present inventors, favorable results were obtained by adjusting the angle formed by the air bearing surface with respect to the magnetic head element formation surface on the substrate within a range of 90 ° ± 0.3 °. .

The magnetic head of the present invention is a magnetic head in which a magnetic head element including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording system recording element for writing is formed on a substrate.
An angle formed by the air bearing surface with respect to the magnetic head element formation surface on the substrate is adjusted to an angle within 90 ° ± 0.3 °.

Furthermore, the angle device of the present invention is a bar-shaped device in which a plurality of magnetic head elements including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording system recording element for writing are arranged on a substrate. An angle setting device for setting the grinding angle of the air bearing surface for the block of
A jig for supporting the block is mounted, and an angle adjusting device capable of adjusting the angle of the air bearing surface with respect to a predetermined reference surface in the block, and an angle measuring device for optically detecting the angle are provided. Features.
By using this angle setting device, the angle adjustment step can be efficiently performed.

Further, the lapping of the present invention is a bar-like structure in which a plurality of magnetic head elements including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording system recording element for writing are arranged on a substrate. A wrapping device for wrapping the air bearing surface of a block,
A wrap surface plate and a holder having an angle adjusting mechanism for positioning the air bearing surface of the block in parallel with the wrap surface plate while holding the jig of claim 7 while supporting the block. It is characterized by that.
By using the lapping apparatus having such a configuration, the finishing lapping process can be efficiently performed.

  According to the present invention, it is possible to manufacture a perpendicular magnetic recording type magnetic head capable of realizing a higher recording density in consideration of the magnetic pole length of the recording element when lapping the air bearing surface.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A magnetic head manufacturing method according to an embodiment of the present invention includes a magnetic head element forming process on a wafer substrate, a slider bar cutting process, a grinding / lapping process, and a slider bar cutting process.

In the magnetic head element forming process on the wafer substrate, as shown in FIG. 1A, a plurality of magnetic head elements 1 are formed on one wafer substrate 2 made of AlTiC (Al ₂ O ₃ .TiC) or the like. It is formed by arranging individual pieces.
Next, in the slider bar cutting step, as shown in FIG. 1 (b), the magnetic head elements arranged in an array are cut out as a bar-shaped block by a predetermined number. The block cut out in this way is called a slider bar 3.

  FIG. 2 is an enlarged view showing the appearance of the slider bar. In the figure, the surface marked with S is the air bearing surface facing the recording medium. The air bearing surface S is a target surface for grinding and lapping in a grinding / lapping process described later.

Here, a configuration example of the magnetic head will be briefly described with reference to FIGS.
The slider bar 3 shown in FIG. 2 is cut into a slider having an individual magnetic head as a main part in a slider bar cutting step. FIG. 3 is a perspective view showing the appearance of the slider cut and separated in this way. A magnetic head element 1 (also simply referred to as “magnetic head”) is formed on a part of the slider 4.
FIG. 4 is a diagram schematically showing a cross-sectional configuration example of the magnetic head. FIG. 4 shows a cross section orthogonal to the air bearing surface S. That is, FIG. 4 is a diagram showing a portion of the magnetic head element 1 in FIG. 3 cut along the line AA.

  The magnetic head (magnetic head element 1) has a configuration in which a reproducing head portion 11 having a reproducing element 10 and a recording head portion 12 are stacked on a wafer substrate 2.

The wafer substrate 2 is configured by forming a base layer 21 made of an insulating material such as alumina (Al ₂ O ₃ ) on a substrate 22 made of Altic (Al ₂ O ₃ .TiC) or the like. In FIG. 4, the substrate 22 is cut away, but the actual thickness of the substrate 22 is much thicker than the magnetic head element portion formed thereon.
In the present embodiment, the surface 22a of the substrate 22 or the surface 21a of the underlayer 21 is the “magnetic head element formation surface”.

A lower shield layer 23 is formed on the base layer 21, and the reproducing element 10 is formed above the lower shield layer 23.
The reproducing element 10 is surrounded by an insulating layer 24 made of alumina (Al ₂ O ₃ ) or the like. An upper shield layer 25 is formed on the insulating layer 24.

  The recording head unit 12 employs a so-called perpendicular magnetic recording method, and mainly includes a main magnetic pole 13, an auxiliary magnetic pole 14, and a thin film coil 15 that serve as recording elements. The auxiliary magnetic pole 14 is composed of a magnetic pole part layer 14 a located on the air bearing surface S side, and a yoke part layer 14 b that is connected to the magnetic pole part layer 14 a and bypasses the thin film coil 15.

An element protective film 16 made of alumina (Al ₂ O ₃ ) or the like is formed on the upper magnetic pole 14. The surface 16a of the element protection film 16 is polished so as to be parallel to the surface 22a of the substrate 22 and the surface 21a of the underlayer 21 (that is, the magnetic head element formation surface). Further, the surfaces of the element protective film 16, the substrate 22, and the underlayer 21 are parallel to the reproducing element 10 and the main magnetic pole 13 serving as a recording element.

  The manufacturing method of the present invention is not limited to the magnetic head having the above-described configuration, but can be applied to manufacturing recording heads having various configurations having a recording element and a reproducing element.

Next, the grinding / lapping process will be described.
The grinding / lapping process is further divided into an angle adjustment process and a finishing lapping process.
In the angle adjusting step, the angle of the air bearing surface S is adjusted with respect to the slider bar 3 on the basis of the magnetic head element forming surface on the substrate 22 and the surface is ground. Here, the magnetic head element formation surface that serves as a reference for angle adjustment is the surface 22a of the substrate 22 or the surface 21a of the underlayer 21 as described above. As described above, the surface 16a of the element protective film 16 is polished in parallel with the surface 22a of the substrate 22 and the surface 21a of the base layer 21, and therefore the surface 16a of the element protective film 16 is used as a reference. However, as a result, the angle of the air bearing surface S can be adjusted with reference to the magnetic head element formation surface on the substrate 22. In the present embodiment, the angle of the air bearing surface S of the slider bar 3 is adjusted based on the surface 16a of the element protective film 16 on the basis of the mutual relationship between the surfaces.

FIG. 5 is a diagram showing a method for adjusting the angle of the flying surface of the slider bar.
The air bearing surface S of the slider bar 3 is ground and lapped at a predetermined angle θ with reference to the surface 16a of the element protective film 16 (that is, the surface of the substrate 22 or the surface of the base layer 21). Specifically, in the angle adjustment step, the air bearing surface S of the slider bar 3 is ground to the position indicated by symbol a in FIG. 5, and further polished to the position indicated by symbol b in the finishing lapping step.
The angle θ is determined in consideration of the magnetic pole length L2 of the recording element 13 in addition to the magnetic pole length L1 of the reproducing element 10. Specifically, it is preferable to determine the angle θ in consideration of the following factors.
(1) Variation in generation of magnetic pole length L2 of recording element 13 and magnetic pole length L1 of reproducing element 10 (2) Dimensional difference D between magnetic pole length L2 of recording element 13 and magnetic pole length L1 of reproducing element 10
(3) Dimensional difference D between magnetic pole length L2 of recording element 13 and magnetic pole length L1 of reproducing element 10, and distance B between these elements
Note that L1, L2, D, and B are theoretical values (design values).

Here, an example of calculating θ using the element (3) will be described. θ can be calculated by the following equation.
θ = Tan ⁻¹ (| D−Da | / Ba)
In the above equation, Da is a dimensional difference (actually measured value) of each element length obtained by actually measuring each magnetic pole length of the recording element 13 and the reproducing element 10. Ba is a measured value of the distance between the elements.

  For example, the theoretical values (design values) of L1, L2, B, and D are L1 = 100 nm, L2 = 130 nm, B = 6.5 μm, and D = 30 nm, respectively, and the actually measured values are Ba = 6.5 μm, Da = 35 nm. If these values are applied to the above equation, θ = 0.04 °.

Further, in the actual manufacturing process, there is a variation in which the value of Ba is 6.5 ± 0.5 μm and the value of Da is 30 ± 30 nm. When the angle θ is obtained based on the maximum value (for example: B = 6.0 μm, D = 60 nm) from this variation, θ = 0.29 °.
Thus, according to experiments conducted by the present inventors, when the angle θ is set within a range of 90 ° ± 0.3 °, preferably within a range of 90 ° ± 0.15 °, high-density recording is performed. Thus, a perpendicular magnetic recording head having a characteristic that achieves the above can be manufactured with high yield.

FIG. 6A is a diagram schematically showing an angle setting device used in the angle adjustment step, and FIG. 6B is a diagram schematically showing a grinding device used in the step.
As shown in FIG. 6A, the angle setting device includes a jig 30 that supports the slider bar 3, an angle adjusting device 40, and an angle measuring device 50.
The slider bar 3 is fixed to the jig 30 with the air bearing surface S disposed on the outer surface. The jig 30 is mounted on the movable table of the angle adjusting device 40. The angle adjusting device 40 includes a base 41, a movable base 42, and an electromechanical angle correction mechanism (for example, an actuator 43 made of a piezoelectric element or the like). The movable base 42 is configured such that one end side is connected to the base 41 via a hinge 44 and the other end side is driven by an actuator 43. That is, the movable base 42 swings around the hinge 44 with the driving force of the actuator 43.

  The angle adjusting device 40 is disposed on the upper surface of the horizontal table 60, and the flying surface S of the slider bar 3 fixed to the jig 30 protects the element when the flying surface S is perpendicular to the upper surface of the table 60. The surface 16 a of the film 16 is set so as to be parallel to the upper surface of the table 60. From this setting state, the actuator 43 is driven to tilt the air bearing surface S, whereby the angle of the air bearing surface S is adjusted.

An optical angle measuring instrument 50 such as a laser autocollimator is installed on the upper surface of the table 60, and the air bearing surface S with respect to the upper surface of the table 60 (that is, the surface 16 a of the element protection film 16) by the angle measuring instrument 50. The angle is measured with high accuracy.
The actuator 43 of the angle adjusting device 40 is controlled based on the angle of the air bearing surface S measured by the angle measuring device 50. In this manner, the flying surface S of the slider bar 3 is adjusted to the preset angle θ with respect to the surface 16a of the element protective film 16.

  After the angle adjustment with respect to the flying surface S of the slider bar 3 is completed, the flying surface S of the slider bar 3 is ground by the grinding machine 61 as shown in FIG. The grinding machine 61 has a grinding surface disposed at a right angle with respect to the upper surface of the table 60. Therefore, the air bearing surface S of the slider bar 3 is ground while maintaining the angle θ set by the angle adjusting device 40. The grinding amount here is, for example, about 20 to 30 μm, and the air bearing surface S is polished by about 6 to 7 μm in the subsequent finishing lapping step. By reducing the amount of polishing in the final lapping process, the grinding / lapping process can be efficiently performed in a short time.

FIG. 7 is a diagram schematically showing a lapping apparatus used in the finishing lapping process.
The wrapping apparatus includes a holder 80 that is disposed to face the lap surface plate 70. The holder 80 has a side portion 81 that can swing with respect to the bottom surface, and the jig 30 is attached to the outer surface of the side portion 81. At this time, the jig 30 is mounted with the air bearing surface S of the slider bar 3 as the lower surface.
A plurality of (two in the figure) dummy bars 82 are mounted on the bottom surface of the holder 80. The dummy bar 82 has a floating surface S processed at right angles to the magnetic head element formation surface on the substrate 22. The holder 80 is positioned so that the air bearing surface S of these dummy bars 82 contacts the lap surface plate 70 in parallel.

  The holder 80 is equipped with an electromechanical angle correction mechanism (for example, an actuator 83 made of a piezoelectric element), and the side portion 81 can be swung by the driving force of the actuator 83. The air bearing surface S of the slider bar 3 fixed to the jig 30 is positioned in parallel with the lapping surface plate 70 by the swinging operation of the side portion 81.

  The angle data set in the angle adjustment process is used for controlling the actuator 83. Based on this angle data, the actuator 83 is driven to automatically place the air bearing surface S ground at a predetermined angle θ with respect to the magnetic head element forming surface on the substrate 22 in parallel with the lapping platen 70. Can do.

  In the final lapping process, the air bearing surface S is polished in parallel by the actuator 83 while maintaining the angle θ set in the angle adjusting process. In consideration of mechanical errors and the like, it is possible to finely adjust each element 10 and 13 to be processed to a desired length while measuring the electric resistance of each element 10 and 13.

  The slider bar 3 whose air bearing surface S has been ground and lapped in this way is then cut into individual magnetic head elements in a slider bar cutting step. Since this process has been conventionally performed in the manufacturing process of the magnetic head, a detailed description thereof is omitted here.

In addition, this invention is not limited to embodiment mentioned above.
For example, the angle adjustment step can be performed without using the angle setting device having the configuration shown in FIG. 6, and the finishing lapping step can also be performed without using the holder shown in FIG. 7.

(A) is a perspective view showing an appearance of a wafer substrate on which a magnetic head element is formed, and (b) is a perspective view showing a state in which a slider bar is cut out from the wafer substrate. It is a perspective view which shows the external appearance of a slider bar. It is a perspective view which shows the outline | summary of the slider provided with the magnetic head. It is a figure which shows typically the example of a cross-sectional structure of a magnetic head. It is a figure which shows the angle adjustment method of the air bearing surface of a slider bar. (A) is a figure which shows typically the angle setting apparatus used at an angle adjustment process, (b) is a figure which shows typically the grinding device used for the same process. It is a figure which shows typically the lapping apparatus used at a finishing lapping process.

Explanation of symbols

1: magnetic head element, 2: wafer substrate, 3: slider bar, 4: slider, 10: reproducing element, 13: main magnetic pole (recording element), 16: element protective film, 21: underlayer, 22: substrate Jig, 40: Angle adjustment instrument, 41: Base, 42: Movable stage, 43: Actuator, 44: Hinge, 50: Angle measurement instrument, 60: Table, 70: Lap surface plate, 80: Holder, 81: Side, 82: dummy bar, 83: actuator

Claims (8)

A step of arranging a plurality of magnetic head elements including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording type recording element for writing on a substrate; and A step of cutting each block as a bar-shaped block, a grinding / lapping step of grinding and lapping the air bearing surface of the block, and a step of cutting the block into individual magnetic head elements,
The grinding / lapping process is adjusted by the angle adjusting process of adjusting the angle of the air bearing surface with respect to the block with respect to the magnetic head element forming surface on the substrate and grinding the surface, and the angle adjusting process. And a finishing lapping step of lapping the air bearing surface at an angle. In the angle adjustment step, the angle of the air bearing surface with respect to the magnetic head element formation surface on the substrate is adjusted based on the generation variations of the magnetic pole length of the recording element and the magnetic pole length of the reproducing element. A method of manufacturing a magnetic head according to claim 1. In the angle adjustment step, the angle of the air bearing surface with respect to the magnetic head element formation surface on the substrate is adjusted based on a dimensional difference between the magnetic pole length of the recording element and the magnetic pole length of the reproducing element. A method for manufacturing the magnetic head according to claim 1. In the angle adjustment step, the angle of the air bearing surface with respect to the magnetic head element formation surface on the substrate is determined based on the dimensional difference between the magnetic pole length of the recording element and the magnetic pole length of the reproducing element and the distance between these elements. The method of manufacturing a magnetic head according to claim 1, wherein adjustment is performed. 6. The angle adjustment step, wherein an angle formed by the air bearing surface with respect to a magnetic head element forming surface on the substrate is adjusted within a range of 90 [deg.] ± 0.3 [deg.]. A method for manufacturing a magnetic head according to one item. In a magnetic head in which a magnetic head element including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording system recording element for writing is formed on a substrate,
A magnetic head in which an angle formed by the air bearing surface with respect to a magnetic head element formation surface on the substrate is adjusted to an angle within 90 ° ± 0.3 °. A magnetic head element including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording system recording element for writing is formed on a substrate in the form of a bar-shaped block formed on a substrate. An angle setting device for setting a grinding angle,
An angle adjusting device capable of adjusting the angle of the air bearing surface with respect to a predetermined reference surface in the block and mounting an jig for supporting the block, and an angle measuring device for optically detecting the angle. An angle setting device. An air bearing surface is formed on a bar-shaped block in which a plurality of magnetic head elements including a reproducing element for reading information recorded on a recording medium and a perpendicular magnetic recording system recording element for writing are arranged on a substrate. A wrapping device for wrapping,
Lap surface plate,
A holding tool having an angle adjustment mechanism for holding the jig of claim 7 while supporting the block and positioning the air bearing surface of the block in parallel with the lap surface plate. Wrapping device.

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