JP3230860B2 - Magnetic head processing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for processing a magnetic head, and more particularly, to a method for precisely forming a crowning processing surface having a uniform convex curvature on the floating surface of a magnetic head facing a magnetic disk. The present invention relates to a magnetic head processing method and apparatus suitable for preventing sticking between a magnetic disk and a magnetic head when the magnetic disk starts rotating.

[0002]

2. Description of the Related Art As shown in FIG. 10, a magnetic head 8 for a magnetic disk device starts rotating while being mounted on a magnetic disk 9, and at this time, air accompanying the rotation of the magnetic disk 9 is rotated. By the dynamic pressure, 0.2
It floats from μm to 0.1 μm. The smaller the flying height, the higher the recording density.

FIG. 11 is an external view of a magnetic head 8. The flying surface 8a of the magnetic head is formed by forming a thin film element on an end face of ceramics and polishing to a surface roughness of 0.01 μm or less and a flatness of 0.1 μm or less. Finished by processing. Magnetic head 8
Are floated by air dynamic pressure generated by rotation of the magnetic disk 9.

However, when the magnetic disk 9 stops rotating, almost the entire floating surface 8a of the magnetic head 8 comes into contact with the magnetic disk 9, as shown in FIG. For this reason, the magnetic disk 9 and the flying surface 8a of the magnetic head come into close contact with each other and stick, and the magnetic head 8 does not float even when the magnetic disk 9 starts rotating, causing a head crash.

To prevent the magnetic head 8 from sticking,
It has been proposed to reduce the contact area of the contact portion between the air bearing surface 8a of the magnetic head 8 and the magnetic disk 9. In this method, as shown in FIG. 12B, a crowning process is performed to form a convex curvature surface having a predetermined crown height δ on the floating surface 8a of the magnetic head 8, and the magnetic disk 9 is formed by the crowning process. To reduce the area of contact and prevent the adhesion state.

As a conventional technique of crowning processing for forming a convex arc-shaped curved surface, a grinding cutter in which a sliding surface of a magnetic head fixed to a table with a fixing jig is formed into a predetermined curvature shape is used. (For example, Japanese Unexamined Patent Publication No. 61-156505), or the floating surface slightly deformed into a concave shape by applying an adjusted constant moment to the back surface of the magnetic head before processing is flattened. Wrap and
By releasing the restraint of the moment, a magnetic head processing method that obtains a convex air bearing surface (for example,
JP-A-1-31049, JP-A-61-199765
Publications).

[0007]

SUMMARY OF THE INVENTION Among the above prior arts,
In the method using a grinding cutter, if the frequency of use of the grinding cutter increases, the wear of the grinding cutter locally deteriorates the shape accuracy of the grinding cutter, so that the shape of the sliding surface of the magnetic head relatively deteriorates, and There is a problem that a crowning shape cannot be obtained, and at the same time, there is a disadvantage that in order to change the crowning shape, another grinding cutter having a different curvature must be prepared.

Further, the method of releasing the restraint of the moment applied before processing to obtain a convex floating surface requires a jig for applying the above-mentioned moment, and the deformation applied to the back surface of the magnetic head even if the applied moment is adjusted. Therefore, it is difficult to make the air bearing surface a uniform curvature even when the constraint on the moment is released. The formation of the crowned surface by this method also has a problem in terms of processing efficiency.

[0009] In view of the above problems of the prior art, the present invention provides:
On the floating surface of the magnetic head facing the magnetic disk, a crowned surface with a uniform convex curvature is easily and accurately formed with high efficiency, and the adhesion between the magnetic disk and the magnetic head when starting rotation of the magnetic disk It is an object of the present invention to provide a method and an apparatus for processing a magnetic head which can prevent the occurrence of the magnetic head.

[0010]

To achieve the above object, according to an aspect of, the processing method of a magnetic head of the present invention, (i) the upper surface is pivotable flat Jo Tokoro speed polishing platen
The Ken MigakuOsamugu placed on, (ii) predetermined the polishing jig relative to the rotational speed of the polishing table
The rotatable speed ratio, the lower surface of the (iii) the polishing jig, a plurality of magnetic heads is Alignment, a dummy member having a substantially same size and shape as the magnetic head obtained by the aligned The dummy material side is placed in contact with the upper surface of the polishing platen via a parallel leaf spring, and is disposed substantially parallel to each other at a predetermined interval to rotate the polishing platen and the polishing jig. , (iv) the periodic expansion and contraction of the parallel leaf spring due to its rotation, by a repeated swing oscillating motion to the polishing jig, (v)該首Ri by the swing oscillating motion, the magnetic head the contact surface between the polishing platen surface is also of that to form a crowned surface with a predetermined curvature.

Further, the processing unit of the magnetic head of the present invention, (i) upper surface rotatable polishing constant Edition in flat Jo Tokoro speed
When, through the (ii) a plurality of magnetic heads were Alignment under surface, said aligned parallel leaf springs the dummy member side and a dummy member having a substantially same size and shape and the magnetic head was and the polishing surface plate in contact the upper surface, and abrasive relative arranged substantially in parallel with a predetermined interval platen to the placed polishing jig, the outer circumference of its a (iii) the polishing jig A plurality of rollers for guiding and supporting the surface and rotatably driving at a predetermined speed ratio with respect to the rotation speed of the polishing table; and (iv) rotating the polishing table and the polishing jig. When moved, the polishing jig is configured to be capable of swinging and swinging repeatedly due to the periodic expansion and contraction of the parallel leaf spring.

[0012]

A polishing jig having a circular outer peripheral surface on an upper portion is placed on a polishing platen, and the polishing platen and the polishing jig are rotated so as not to slip each other. The dummy head with the magnetic head and the parallel plate spring interposed in parallel with each other is a simple oscillation type repetitive swing of a constant amplitude generated in the polishing jig by the periodic expansion and contraction of the parallel plate spring. The dynamic motion is performed together with the polishing jig, and a periodic variation is caused in the polishing load acting downward on the magnetic head and the dummy material. This fluctuation causes a difference in the polishing load acting on the magnetic head and the dummy material, and, together with the repetitive swinging movement of the angular velocity corresponding to the rotation speed of the polishing platen and the polishing jig, causes the magnetic force. It is possible to form a crowned surface with a predetermined curvature on the air bearing surface of the head.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic head processing apparatus according to the present invention will be described below with reference to FIGS. FIG. 1 is a plan view showing a magnetic head processing apparatus, and FIG.
II is a cross-sectional view, FIG. 3 is a perspective view showing the lower surface side of the polishing jig, FIG. 4 is a plan view showing the lower surface side of the polishing jig, and FIG.
It is V sectional drawing.

[0014] In FIGS. 1 to 5, 1 is prior to processing the magnetic head (hereinafter, also referred to as workpiece), 2 an upper surface is flat, rotatable at a predetermined speed V ₁ in the direction of the arrow shown in FIG. 1 polishing The platen 3 has a circular outer peripheral surface 3a on the upper part, and is a polishing jig placed on the polishing platen 2. On the lower surface of the polishing jig 3, one row is provided as shown in FIGS. A large number of magnetic heads 1 several to several tens aligned with high precision, and a dummy material 7 formed in the same size and shape as the large number of aligned magnetic heads 1 And in parallel with each other in a contact state and at a predetermined interval. However, in this case, the dummy material 7 is provided on the lower surface of the polishing jig 3 by the parallel leaf spring 4.
Attached through. Reference numeral 5 denotes a plurality of rollers for guiding and supporting the circular outer peripheral surface 3a of the polishing jig 3 as shown in FIGS. 1 and 2, and each roller 5 moves the polishing jig 3 in the direction of the arrow shown in FIG. Constant rotation speed V in the same direction as the panel 2)
₂ is driven by a driving mechanism (not shown) at a fixed speed ratio to the rotation speed V ₁ of the polishing table 2. Note that while the polishing platen 2 stops rotating, the polishing jig 3 also stops.

A polishing platen 2 and a polishing jig 3 having the above configuration
Are rotated at speeds V ₁ and V ₂ so as not to slip from each other, the parallel leaf spring 4 expands and contracts periodically, and the polishing jig 3
Is repeatedly swung. This operation will be described with reference to the principle diagram of FIG.

In FIG. 6, assuming that the swing angle of the swing motion is θ, the swing cycle is f, and the length of the work 1 is b, the swing angular velocity ω is expressed by the following equation (1). .

[0017]

(Equation 1)

Here, R is the radius of curvature of the machined surface and is represented by the following equation (2).

[0019]

(Equation 2)

Next, the processing speed dZ / dt is expressed by the following equation (3), where P is the polishing load and P is the polishing constant.

[0021]

(Equation 3)

From the above equations (1), (2) and (3),
The generation equation of the crowned surface shape can be obtained as the following equation (4).

[0023]

(Equation 4)

If the desired shape of the formed shape is given as Z (X), the angular velocity distribution of the swinging motion can be obtained from equation (4). Then, the work 1 is oscillated and polished by the obtained angular velocity distribution, thereby polishing the work 1.
It is possible to create a desired crowning processing surface shape.

Next, the crowning operation of the present invention will be specifically described with reference to FIGS. FIG.
FIG. 8 is an explanatory diagram of the crowning operation, and FIG. 8 is an explanatory diagram of a change in the polishing load at the time of the crowning operation, corresponding to the processing operation of FIG.

FIG. 7A is a side sectional view showing a stopped state of the polishing platen 2 and the polishing jig 3. In this case, the polishing load (own weight of the polishing jig 3) P applied to the center of gravity “b” of the polishing jig 3 is, as shown in FIG. The polishing jig 3 is uniformly loaded on the dummy material 7 at the position, and maintains the horizontal state (non-swinging state). Subsequently, in order to start processing, the polishing table 2 and the polishing jig 3 are moved at speeds V ₁ and V ₂ so as not to slip each other.
When the roller is rotated, the roller 5 supporting the polishing jig 3 at the position "a" (the height from the upper surface of the polishing platen 2) is opposed to the polishing resistance of the workpiece 1 and the dummy material 7 at the same time as the start. h position), a reaction force μP acts, and a moment μPh due to the reaction force μP acts. Here, μ is a polishing resistance coefficient. For this reason, as shown in FIG. 8B, the vertical polishing load between the position “C” of the work 1 and the position “D” of the dummy material 7 is the same as the position “D” of the dummy material 7. As shown in FIG. 7B in the rotation start state, the parallel plate spring 4 supporting the dummy material 7 is extended to bring the polishing jig 3 into the inclined state.

When rotated by 90 ° from the above state, the distances from “a” to “c” and “d” become equal, and the moment acting on the work 1 and the dummy material 7 becomes equal as shown in FIG. Therefore, there is no difference in the polishing load.
Therefore, the polishing jig 3 is in a horizontal state as shown in FIG.

Further, at a position 180 ° from the above-mentioned stop state by rotating 90 °, as shown in FIG. Is larger and the state is opposite to that of FIG. For this reason, as shown in FIG. 7D, the parallel leaf spring 4 supporting the dummy material 7 contracts, and the polishing jig 3 is inclined in a direction opposite to the direction symmetric to FIG. 7B.

Further, at the position shown in FIG. 7E which is rotated by 90 ° and 270 ° from the stop state, the position shown in FIG.
As in the state of FIG. 8C, there is no difference in the polishing load as shown in FIG. 8E, so that the polishing jig 3 returns to the horizontal state as shown in FIG. .

Further, when the motor is further rotated by 90 ° and rotated once (360 °) from the above-mentioned stopped state, as shown in FIGS.
It returns to the state of (b).

By repeating the operations shown in FIGS. 7B to 7E, the parallel leaf spring 4 is periodically expanded and contracted to cause the polishing jig 3 to repeatedly swing and swing. On the contact surface with the upper surface of the polishing platen 2, a plurality of uniformly convex crowning processing surface shapes Z (X) having a predetermined curvature can be simultaneously formed.

The above-mentioned crowning processing surface shape Z (X)
Is determined by the compliance Res of the parallel leaf spring 4, and the crown height δ of the formed crowned surface is obtained by the following theoretical formula.

[0033]

(Equation 5)

In the equation, L is the distance between the work 1 and the dummy material 7.

FIG. 9 shows the parallel leaf spring 4 obtained by the above-mentioned theoretical formula.
The correlation value between the compliance Res and the crown height δ is shown by a solid line. The experimental value obtained by changing the compliance Res is in good agreement with the theoretical value. By setting the compliance Res of the parallel leaf spring 4 and causing the polishing jig 3 to repeatedly swing and swing, it can be easily performed. In addition, it is possible to obtain a crowned surface having a desired crown height δ in terms of efficiency. Therefore, when the rotation of the magnetic disk 9 is stopped, the floating surface of the magnetic disk 1 comes into line contact with the upper surface of the magnetic disk 9, and the adhesion between the magnetic disk 9 and the magnetic head 1 at the time of starting rotation is reliably prevented. be able to.

As an example of the experimental results, when the length b of the work 1 is 4 mm, the crown height δ is set to 0.05.
It has been confirmed that it can be formed to a thickness of from 0.1 μm to 0.1 μm.

[0037]

As described above, according to the present invention, a crowning-processed surface having a uniform convex curvature can be formed easily, accurately and highly efficiently on the floating surface of a magnetic head facing a magnetic disk. This makes it possible to reliably prevent sticking between the magnetic disk and the magnetic head when the magnetic disk starts rotating.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a magnetic head processing apparatus according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view showing a lower surface side of the polishing jig shown in FIG. 1;

FIG. 4 is a plan view showing a lower surface side of the polishing jig shown in FIG. 1;

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a diagram illustrating the principle of creation of a crowned surface according to the present invention.

FIG. 7 is an explanatory diagram of the crowning processing operation of the present invention.

FIG. 8 is a diagram illustrating a change in a polishing load during the crowning process of the present invention.

FIG. 9 is a correlation diagram between crown height and spring compliance according to the present invention.

FIG. 10 is a diagram showing a relative positional relationship between a magnetic head and a magnetic disk.

FIG. 11 is an external view of a magnetic head.

FIG. 12 is an explanatory diagram of a contact state between a magnetic head and a magnetic disk when rotation is stopped.

[Explanation of symbols]

1 ... magnetic head (work) before processing, 2 ... polishing platen, 3
... Polishing jig, 3a ... circular outer peripheral surface, 4 ... parallel leaf spring, 5 ...
Roller, 7 ... Dummy material of magnetic head, 8 ... Magnetic head,
8a: flying surface, 9: magnetic disk, 10: swing support,
10a: Instantaneous rotation center.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chihiro Isono 2880 Kozu, Odawara-shi, Kanagawa Hitachi, Ltd. Storage Systems Division (56) References JP-A-2-308406 (JP, A) JP-A-4 -358378 (JP, A) JP-A-4-146070 (JP, A) JP-A-1-135467 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24B 19/26 G11B 5/187 G11B 21/21 101

Claims (2)

(57) [Claims] 1. A (i) upper surface is placed on research MigakuOsamugu the rotatable polishing platen with flat Jo Tokoro speed, (ii) the rotational speed of the polishing jig is the polishing platen Prescribed for
The rotatable speed ratio, the lower surface of the (iii) the polishing jig, a plurality of magnetic heads is Alignment, a dummy member having a substantially same size and shape as the magnetic head obtained by the aligned The dummy material side is placed in contact with the upper surface of the polishing platen via a parallel leaf spring, and is disposed substantially parallel to each other at a predetermined interval to rotate the polishing platen and the polishing jig. , (iv) the periodic expansion and contraction of the parallel leaf spring due to its rotation, by a repeated swing oscillating motion to the polishing jig, (v)該首Ri by the swing oscillating motion, the magnetic head A method for processing a magnetic head, comprising: forming a crowning processing surface having a predetermined curvature on a contact surface with a polishing platen upper surface. Wherein (i) the upper surface and the polishing constant Edition rotatable in flat Jo Tokoro velocity, (ii) a plurality of magnetic heads were Alignment under surface, the magnetic head substantially obtained by the aligned A dummy material having the same size and shape is placed relative to the upper surface of the polishing platen via a parallel leaf spring on the side of the dummy material, and substantially parallel to each other at a predetermined interval. and placed on a polishing jig on the board, it can rotate (iii) the polishing jig to guide the outer peripheral surface of its, and supporting a predetermined speed ratio relative to the rotational speed of the polishing surface plate And (iv) when the polishing platen and the polishing jig are rotated, the polishing jig is repeatedly swung by a cyclic expansion and contraction of the parallel plate spring. An apparatus for processing a magnetic head, wherein the apparatus is configured to be capable of being used.