JPS61162812A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To obtain excellent recording and reproducing characteristics even when line recording density is high by grinding the bottom surface of the housing of a magnetic head which is worked spherically in parallel to a plane contacting the center of a gap on the spherical surface. CONSTITUTION:A bored recess part which has a surface D-D parallel to a surface C-C of a surface grinder bed 23 is provided on a flat plate 22 and a peak hole 20 having a 0.5mm diameter is formed at the center part. Then, while an observation is made through a microscope of X100 power from the opposite side of the housing 6, the center of the gap on the spherical surface of the housing 6 worked to 60R is adjusted within 10mum about the center of the peak hole 20 so that the center is aligned to the center of the peak hole 20 and then fixed with electron wax 21. The flat plate 22 where plural housings 6 are fixed is fitted onto the surface grinder bed 23 and a hatched part 25 is ground with a grindstone 24 of #1,000. Consequently, the peak shift of the gap from the fixation surface for the housing 6 is easily reduced to <=0.05mm and the spacing between the gap and a medium is made extremely small, thereby obtaining excellent recording and reproducing characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic recording/reproducing device in which a medium and a recording head are in contact with each other, and particularly to a method of manufacturing a magnetic head used in a floppy disk driver.

(Prior Art) A conventional example will be explained using FIGS. 2, 3, and 4.

FIG. 2 is a perspective view of the magnetic head chip before it is molded into a housing, in which 1 is the recording/reproducing gap, 2 is the first
3 is a second ferrite core, 4 is a glass material, and 5 is a coil.

FIG. 3 is a plan view (a) and a front sectional view (b) of a molded magnetic head whose gap surface is formed into a spherical surface, where 6 is a housing and 7 is an adhesive.

FIG. 4 is an explanatory view of the spherical surface machining method, in which (a) shows the spherical grindstone 12, and (b) shows the housing fixing jig 11.

In FIG. 2, a first ferrite core 2 provided with a groove and a second rod-shaped ferrite core 3 are joined with a glass material 4, and a gap 1 is formed.

Thereafter, as shown in FIG.
As shown in FIG. 4, mold the housing 6 with adhesive 7 on the housing fixing jig 11 made of a convex spherical body so that the A-A of the housing 6 is parallel to the plane perpendicular to the normal line. Then, the housing 6 is fixed, and a spherical grindstone 12 having a concave spherical surface is rotated so as to be pressed against the gap 1 to process the surface of the gap 1 into a spherical surface.

In this way, it is used in floppy disk drivers, and the spherical surface prevents damage to the medium.

(Problem to be Solved by the Invention) However, in this processing, the deviation of the center of the gap 1 from the apex of the housing 6 with respect to the A-A plane is 0.15.
We can only guarantee that it will be within mm.

This is caused by the misalignment of the gap 1 with respect to the center of the outer diameter of the housing, the spherical accuracy of the spherical grindstone 12, the housing fixing jig 11, etc.

Figure 5 shows the magnetic medium and magnetic head during recording and reproduction, where 8 is the magnetic medium, 9 is the spacing, IO is the pad,
13 indicates the vertex shift.

As shown in FIG. 5, when the vertex deviation I3 becomes large.

Since the housing 6 is fixed to the driver on the A-A plane, even if the magnetic medium 8 is pressed into the gap 1 with the pad 10,
A spacing 9 is created between the gap 1 and the medium 8 due to the rigidity of the magnetic medium 8, resulting in a decrease in output.

This leads to deterioration of recording and playback characteristics such as modulation.

The effect of this spacing 9 becomes larger as the linear recording density increases.When the linear recording density is about 10KBPI, the effect is small if the apex shift mentioned above is within 0.15 mm, but as the density increases, This apex shift makes a large contribution, and at a recording density of 100 KBPI, it is necessary to suppress the apex shift to within 0.05 mm, which cannot be achieved by conventional methods.

(Means for Solving the Problems) The present invention minimizes the above-mentioned vertex deviation to within 0.05 mm, and the spacing 9 between the gap 1 and the magnetic medium 8
This is a system that achieves good recording and reproducing characteristics even at high linear recording densities by horizontally reducing the size of the magnetic head. Grinding is done in parallel.

(Function) With the above technical means, the magnetic head of the present invention has a gap center on a spherical surface with respect to the bottom surface of the housing near the apex.

Therefore, when the above magnetic head is attached to the driver,
Since it contacts the medium near the center of the gap, the spacing between the gap and the medium is extremely small even if the medium has high rigidity.

As a result, good recording and reproducing characteristics can be obtained even at high linear recording densities.

(Embodiment) FIG. 1 shows the structure of an embodiment of the magnetic head manufacturing method of the present invention, in which 1 is a gap, 6 is a housing, 20 is an apex hole, 21 is electron wax, 22 is a flat plate, 23 24 is a surface grinder bed, and a grindstone 525 is a grinding allowance.

In this example, the surface C of the surface grinder bed 23 is placed on the flat plate 22.
A recessed portion having a depth of 5+wm that is sufficient to accommodate a housing 6 having an outer diameter of 16 mm and having a plane D-D parallel to -C is provided, and an apex hole 20 with a diameter of 0.5 m+n is provided in the center of the recess. Then, while checking the center of the gap 1 on the spherical surface of the housing 6 processed to 60R with a microscope at 100 times magnification from the opposite side of the housing 6, make sure that the center of the gap 1 on the spherical surface of the housing 6 is located at the center of the apex hole 20. Adjust to within 10μ and fix with electron wax 21.

Next, as described above, the flat plate 22 to which the plurality of housings 6 are fixed is mounted on the surface grinding machine bed 23, and
Grind the shaded area 25 with a grindstone 24 numbered 000.

By doing this, the center of gap 1 is near the apex with respect to the grinding surface B-8, and the apex deviation is 0.03 sn.
Located within

Even if the parallelism of the surface grinder bed 23 and the flat plate 22 with respect to the parallel movement of the grinding wheel 24 is poor at ±3 μι for 20 mm, the resulting apex deviation on the 60R spherical surface is 0.018 mm, and the above-mentioned Even if this is added to 0.03m1, it is possible to secure within 0.05+*m, leaving some margin.

Therefore, even if the equipment used for grinding is not a flat plate grinder,
Other grinding devices that do not have high precision are also possible.

(Effects of the Invention) As explained above, according to the present invention, after the spherical surface of the magnetic head is machined, the surface in contact with the recording/reproducing gap on the first spherical surface is magnetically adjusted to be parallel to the reference plane C-C of the flat plate. Fix the head and align the bottom surface A- of the housing parallel to this reference plane C-C.
By grinding A to create a B-B surface, the apex deviation of the gap with respect to the fixed surface of the housing 6 can be easily reduced to 0.0.
5+nm or less, and as a result, the spacing between the gap and the medium can be made extremely small, thereby providing a magnetic head that provides good recording and reproducing characteristics.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the magnetic head manufacturing method of the present invention, FIG. 2 is a perspective view of the magnetic head chip before being molded into a housing, and FIG. 3 is a spherical surface on the gap surface after molding. FIG. 4 is an explanatory diagram of the spherical surface processing method, and FIG. 5 is a diagram showing the magnetic medium and the magnetic head during recording and reproduction. 1... Recording/reproducing gap, 2... First ferrite core, 3... Second ferrite core. 4...Glass material, 5...Coil, 6...Housing, 7...Adhesive, 8...Magnetic medium, 9...
・Spacing, 10... Pad, 11... Housing fixing jig, 12... Spherical grindstone, ]3... Vertex deviation 220... Vertex hole, 21... Electron wax, 22... Flat plate, 23...Surface grinder head, 2
4...Whetstone, 25...Grinding allowance. Patent applicant Matsushita Electric Industrial Co., Ltd. Figure 1 δ... Tuna I/1 generation (a) (b)

Claims (1)

[Claims] The surface of the magnetic head that is in contact with a medium containing a magnetic material, including the recording/reproducing gap, is machined into a spherical surface along with the housing in which the magnetic head chip is held, and the magnetic head is placed on a surface parallel to the grinding surface of the grinding machine. A method of manufacturing a magnetic head, comprising: fixing the housing so that the gaps thereof are in contact with each other, and grinding the bottom surface of the housing using the grinding machine.