JPH0512623A - Composite magnetic head device and manufacturing method thereof - Google Patents

Abstract

PURPOSE:To obtain a large capacity complex magnetic head device superior in reliability with good productivity by disposing an upper magnetic head and a lower magnetic head, which are arranged parallel via nonmagnetic substances between sliders. CONSTITUTION:The upper magnetic head by using a wide write and narrow read system (composed of a read core 72 and a write core 73) and the lower magnetic head by using a precedent erasing system (composed of a read and write core 70 and a erase core 71) are arranged parallel via the nonmagnetic substances 40-43, and both of the heads are disposed between the individual sliders 16-19. Thus, when a magnetic disk of high density specifications is used, because of such a wide write and narrow read type that the width of the write core 73 is wider than the width of the read core 72, an unerased remainder at the time of recording in an open loop system even in the high density specifications is eliminated, and also the read-out can securely be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head device for magnetically recording information on a magnetic recording medium by a plurality of data tracks and reading the recorded information, and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 18 is a structural example showing a conventional magnetic head device disclosed in, for example, Japanese Patent Laid-Open No. 63-103408. In the figure, reference numeral 1 is a slider, and 2 is a slider 1 incorporated in a first read / write (hereinafter referred to as R / W)
The first R / W core forming the head 2a, 3 is the first R / W gap formed by the R / W core 2, and 4a is R
The first R / W coil wound around the / W core 2 is an erase core of an erase head arranged so as to erase both ends of a data track on a magnetic disk (not shown) formed by the R / W gap 3. 6 is an erase gap formed by the erase core 5, 7 is an erase coil wound around the erase core 5, and 8 is a slider 1.
A second R / W core, which is incorporated with the first R / W head 2a into a second R / W head 8a to form a second R / W head 8a.
Second R / W gap formed by / W core 8;
b is a second R / W coil wound around the R / W core 8. Erase heads 7a and 7b (not shown) arranged corresponding to R / W cores 2 and 8 are arranged for R / W heads 2a and 8a, respectively.

In FIG. 18, the track widths of the first R / W core 2 and the second R / W core 8 are different, and the first R / W head 2a and the first erase head 7a are different from each other.
The composite head composed of 1) and the composite head composed of the second R / W head 8a and the second erase head are individually manufactured and embedded in the slider 1.

Next, the electrical operation of the magnetic head device will be described. The magnetic head device operates as an electric-magnetic converter or a magnetic-electric converter when writing or reading information on the magnetic disk. At the time of writing, a signal current is passed through the R / W coil 4a to generate a strong magnetic field in the vicinity of the R / W gap 3 according to this value, and the magnetic recording medium on the magnetic disk surface is magnetized to write the signal. At the time of reading, which operates as a magnetic-electrical converter, when the magnetic flux of the magnetized magnetic recording medium passes in the vicinity of the R / W gap 3, the information including the amplification of the voltage induced in the R / W coil 4a. Perform the reading process. At this time, when writing and reading the data track using a low density magnetic disk, a lower composite magnetic head having a wide track width is used. On the other hand, when a high density magnetic disk is used to write and read the data track, an upper composite magnetic head having a narrow track width is used.

The background of the need for such a composite magnetic head device will be briefly described. FDD (floppy disk drive) is 8 inches to 5.25 inches, and 3.
5 inch size and miniaturization of equipment have progressed, the market needs for notebook type personal computers have increased recently, and the specific gravity of the small 3.5 inch is rapidly increasing.

On the other hand, in terms of capacity, unformatted 1M
B (megabyte), 1.6MB, 2MB (these are FDD
The tunnel erase system has been widely used in the above), and in recent years, a 4 MB FDD of the preceding erasing system, which is a high-end model of these, has been put on the market.
As software becomes larger and larger with the progress of information society, the FDD has a large capacity, more than 10 times that of the current model.
The demand for is increasing. In order to achieve such a large capacity with a 3.5-inch size, it has been proposed to introduce the tracking servo technology used in fixed disk devices to increase the recording track density.

[0007]

Since the conventional composite magnetic head device is constructed as described above, the slider, the upper magnetic head and the lower magnetic head are individually prepared, and then the three members are combined with an organic adhesive or the like. However, there is a drawback that the productivity is remarkably poor. Further, magnetic crosstalk occurs due to the leakage magnetic flux between the upper magnetic head and the lower magnetic head. Further, there is a problem that the margin of the performance of the magnetic head device is deteriorated because the relative position deviation of the gap between the two heads is likely to occur. An even greater challenge lies in its implementation. An example of a conventional composite magnetic head device is one in which a tunnel erase type composite magnetic head is adopted for both the upper and lower magnetic heads. However, since the recording track width is narrowed in this system, tracking accuracy is improved. In addition, the introduction of the tracking servo device used in the fixed magnetic disk device is indispensable, and there is a drawback that the price of the FDD device, which is one of the major features of being cheaper than the fixed disk device, becomes high.

The present invention has been made to solve the above-mentioned drawbacks and problems, and is excellent in high performance and reliability without magnetic mutual interference between both heads and relative positional deviation of the gap between both heads. The purpose is to obtain a large-capacity composite magnetic head device with high productivity and at low cost. Further current 4
It is an object of the present invention to provide a composite magnetic head device for realizing an easy-to-use FDD by reading each disk of /2/1.6/1MB FDD and having a function of writing to each disk.

Another object of the present invention is to provide a method of manufacturing the composite magnetic head device at low cost. Further, it goes without saying that the adoption of the present composite magnetic head device aims at practical application of a high-density magnetic disk device without introducing an expensive tracking servo device.

[0010]

A composite magnetic head device according to the present invention comprises an upper magnetic head using a wide write narrow read system and a preceding erasing system in order to realize a high density floppy disk device at a low cost. The lower magnetic heads used are arranged in parallel via a non-magnetic material, and both heads are arranged between the slider and the slider.

In the method of manufacturing the composite magnetic head device according to the present invention, the slider, the magnetic shield, the upper magnetic head and the lower magnetic head are not individually formed and then integrally formed. At least the upper magnetic head and the lower magnetic head are integrally formed from the same ferrite core block by a glass bonding method.

[0012]

According to the composite magnetic head device of the present invention, when a high density magnetic disk is used, since the width of the write core is wider than that of the read core, it is a wide write narrow read type. However, the open loop method can eliminate unerasure during recording and ensure reading, and when using a low-density magnetic disk, it is a lower magnetic head of the preceding erasing method with the same read / write width. , Can be surely done by the conventional method.

Further, according to the manufacturing method of the present invention, since the composite magnetic head is integrally formed from one core block at the same time,
The gap between both heads can be formed in-line to improve performance and productivity is good.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a magnetic head device according to an embodiment of the present invention. In the figure, 10, 11, 20 and 21 are Mn-Zn ferrite or N, which are metal oxides, respectively.
An R / W core leg, an erase core leg, which are formed of i-Zn ferrite or an ultrafine supersaturated crystal phase and are formed of a high-hardness iron-based metal magnetic material, which constitute a lower magnetic head in order,
The R / W core center core leg and the erase core center core leg make up the R / W core 70 with the R / W core leg 10 and the R core center core leg 20, and the erase core leg 11 and the erase core center core leg. Erase core 71 is constructed with 21. The R / W core 70 and the erase core 71 form a lower magnetic head 76 of the preceding erasing method. 12, 13, 22, 23
Is a read (hereinafter, referred to as R) core leg, a write (hereinafter, referred to as W) core leg, and R that constitute an upper magnetic head in order.
Center core leg for core and center core leg for W core, R core with 12 core core legs and 22 R core core core legs
72, and the W core 73 is composed of the W core leg 13 and the W core center core leg 23. The R core 72 and the W core 73 formed wider than the R core 72 constitute a wide write narrow read type upper magnetic head. 14, 15 are magnetic shielding parts made of the same material as the R / W core 70 and erase core 71, 16,
17, 18, 19 are sliders, 30, 31, 32 and 33 are Si formed by thin film forming techniques such as sputtering and vapor deposition.
The magnetic gap of each core made of non-magnetic material such as O ₂ and Ta ₂ O ₅ indicates R / W gap, erase gap, R gap, and W gap, and 40, 41, 42, and 43 are representative of glass. Each slider 1 with non-magnetic filler
6, 17 and the lower magnetic head 76, between the lower magnetic head 76 and the magnetic shields 14, 15 and between the magnetic shields 14, 15 and the upper magnetic head 77.
And between the upper magnetic head 77 and the sliders 18 and 19. 44 is the R core 72 and W core 73 of the upper magnetic head,
And the lower magnetic head R / W core 70 and erase core 71
A center spacer made of a non-magnetic member such as glass or ceramic provided to magnetically separate
Reference numerals 60 and 61, 62 and 63, 64 and 65, 66 and 67 are groove portions around which the R / W coil of the lower magnetic head, the erase coil, the R coil of the upper magnetic head, and the W coil are wound in that order.

Next, the operation principle of recording / reproducing of the present composite magnetic head device will be described. When writing or reading information to or from a magnetic disk, if a low-density magnetic disk is used, a lower magnetic head of the preceding erasing method with the same track width for recording and reproduction is used, and a high-density magnetic disk. When using, a wide write narrow read type upper magnetic head whose recording track width is wider than the reproducing track width is used.

It is said that one of the reasons why the FDD has spread so far is that the compatibility of data from one system to another system via a floppy disk, that is, from one FDD to another FDD is high. In order to guarantee the compatibility of this data, the data is recorded with a track width that is somewhat narrower than the track pitch. Taking a 3.5-inch 4MB FDD that employs a pre-erasure type magnetic head as an example, a track density of 135 TPI (the number of tracks per inch), that is, a track pitch of 188 μm is used for data of 120 μm (R / W head track width)
Is. The remaining portion, 68 μm, is called a guard band and is a non-signal portion in which no data is recorded. If there is no positional deviation (off-track) of the head, only the R / W head is necessary, but the head always has some off-track with respect to the track center. An erase head having a track width of 250 μm is provided in front of the R / W head in order to guarantee a guard band between data even when there is this off-track. Current low-density FD
Since D uses the data recording method described above,
It is difficult to increase the track density and achieve high density. In order to increase the track density, the head positioning method is changed from the open loop method by the stepping motor used in the current FDD to the head positioning signal (servo signal) written on the magnetic disk used in the fixed disk device. ) Is read out, and a closed loop (track servo) method is proposed in which the position of the head is corrected and the head position is adjusted to the correct position (for example, Magnetic Recording Research Group material MR90-33). However, since this method involves the introduction of a track servo device, F
This leads to higher prices of DD. In the composite magnetic head device according to the present invention, when recording on the upper magnetic head, a W having a wide track width is recorded.
Since a wide write narrow read type head structure is used for writing with the head and reading with the R head having a narrow track width during reproduction, a large capacity FDD of the same open loop type as the current FDD can be easily realized.

For example, the current 3.5 inch 2/4 MB
Track density is 270 TPI with the same linear recording density as FDD
Assuming a large capacity FDD of 8 MB, guard bandless recording can be realized by setting the track width of the recording head to 94 μm in order to eliminate the unerased portion during recording. on the other hand,
The track width of the reproducing head is smaller than 94 μm and is determined by the off-track amount of this device.

In this recording method, since the write gap and the read gap are different, in the FDD in which data is recorded along the circumferential direction of the magnetic disk, the angle between the direction of the recorded magnetization and the gap surface is not 90 degrees. This causes a problem of azimuth loss during reproduction. This loss increases as the inner circumference of the disk increases. Therefore, it is desirable that the distance between both gaps is as small as possible. With the head using 8 MB, if this value is set to about 100 μm, good recording / reproducing performance can be secured.

[Embodiment 1] Next, a method of manufacturing a composite magnetic head device according to an embodiment of the present invention will be described with reference to FIGS.

2 to 11 are views for explaining the manufacturing process of the composite magnetic head device according to one embodiment of the present invention. First, Figure 2
As shown in, the upper magnetic head has R core legs 12 and W core legs 13
And a core piece 10 made of ferrite, which is the material for the R / W core leg 10 and the erase core leg 11 of the lower magnetic head.
0 and a center core piece 20 made of ferrite, which is the material of the center core legs 20, 21, 22, and 23 of both heads
Prepare 0. These pieces are sliders 16, 17, 18, 1
9. It also serves as a component of the magnetic shields 14 and 15. Each piece is finished to a predetermined size by grinding and lapping. In particular, the gap surface is mirror-finished without processing distortion.

Of these pieces, the core piece 100 has a coil preliminary groove 10 into which a coil is inserted as shown in FIG.
Processing for making the placing grooves 102, 103 for 1 and mold glass is performed.

After this processing is completed, as shown in FIG. 4, SiO ₂ or the like is formed as the gap material 300 on the gap surface by vapor deposition or sputtering. Gap material
The center core piece 300 may be formed in the same manner as the center core piece 200, that is, a so-called double stack formation may be performed.

After forming the gap member 300, the core piece 100 and the center core piece 200 are united and fixed as shown in FIG. 5, and the glass rods 400 and 401 are used to raise the temperature to perform fusion welding to form a core block 800.

Of these welded core blocks 800, the blocks to be the R core 72 of the upper magnetic head and the R / W core 70 of the lower magnetic head are, as shown in FIG. .About.504 are obliquely applied from the facing surface of the magnetic disk toward the center core surface by grinding using a diamond wheel, for example.
The figure is a schematic illustration, and in reality, it is desirable to increase the number of pair grooves from the viewpoint of mass productivity.

After this processing is completed, the process shown in FIG. 7 is performed. That is, the core block 800 for the upper magnetic head R core 72, the lower magnetic head R / W core 70, the upper magnetic head W core 73, and the lower magnetic head erase core 71.
As shown in the same figure, the core blocks 800 for use are arranged with a gap corresponding to the thickness of the center spacer 44, and a nonmagnetic ceramic spacer or the like is interposed in a part of this gap to prevent gap opening. A load is applied between the core blocks, and a glass rod 402 is poured into the gap and the track width regulating grooves 501 to 504 to form a head block 900.

Next, the track width regulation groove 90 of the W core 73 of the upper magnetic head and the erase core 71 of the lower magnetic head.
1 to 904 are made parallel to the front surface of the head block 900 by grinding as shown in FIG. The depth of the groove is set so as not to cut the head block 900 as shown in the figure. These grooves are the sliders 16-19 and the magnetic shield 1 respectively.
It has the function of 4 and 15 separation grooves.

After finishing the groove processing, as shown in FIG. 9, a glass rod 403 is formed on the disk-contacting surface of the head block 900.
Place, raise the temperature and pour the glass. In this work step, if the glass rod is inserted also in the coil preliminary groove 101, the glass can be sufficiently poured into the deep portion of the groove. Although not shown here, a welding jig is used so as not to cause a gap opening upon hitting the glass mold, and a load is applied to the side surface through mica or the like so that excess glass does not flow out. Thus, as shown in FIG. 10, a composite head 910 having a groove filled with glass is obtained.

After this step, the groove processing shown in FIG. 11 is performed. That is, grooves 64 and 65, 66 and 67, 60 and 61 and 62 for winding the coils of the R core 72 and W core 73 of the upper magnetic head and the R / W core 70 and erase core 71 of the lower magnetic head, respectively. 63
Are formed so as to pass through the core in the direction perpendicular to the disc contact surface.

Finally, by cutting the lower part of the composite head 910 and processing the winding groove, the composite magnetic head according to the present invention shown in the perspective view of FIG. 1 is obtained.

[Embodiment 2] When Mn-Zn ferrite which is a metal oxide is used as the core material of the magnetic head, the wear resistance of the core of the magnetic head becomes a problem. Usually, single crystal or polycrystalline ferrite is used for the head core material of the FDD head, and barium titanate or calcium titanate is used for the slider material, but barium titanate or calcium titanate is superior in wear resistance. Next is single crystal ferrite. Single crystal ferrite also has an orientation dependency, and the sliding surface and sliding direction are (110) <100>, (110) <111
>, (110) <211>, (100) <110>, (100) <110>, (10
0) The <100> orientation is excellent. Polycrystalline ferrite, which has good magnetic properties at low frequencies and is inexpensive, is mainly used for FDDs used at frequencies lower than 1M (mega) Hz, but this material is resistant to brittle plastic flow at grain boundaries. Abrasion is poor. In this case, it is preferable to use high hardness ceramics such as barium titanate and calcium titanate.

FIG. 12 is a perspective view of the second embodiment. In this embodiment, the slider portion is not integrally formed but can be fitted to a separately formed slider member for use. Is made of a material having high abrasion resistance. The composite magnetic head device of this embodiment may be manufactured without forming the slider portion from the beginning in the manufacturing process described above.
Can also be obtained by cutting between the slider and the upper magnetic head and the lower magnetic head. In addition, in the present embodiment, in order to further improve the core efficiency at the time of reproduction, the second feature is that the non-magnetic center spacer between the center cores is eliminated and the center core body type core structure is adopted.

[Third Embodiment] FIG. 13 is a perspective view of a third embodiment. In this embodiment, the magnetic shields 14 and 15 between the core legs of the upper magnetic head and the lower magnetic head, around which the coil is wound in order to reduce the decrease in recording efficiency due to the absorption of magnetic energy during recording in the magnetic shield. The feature is that the ferrite part of is removed. The composite magnetic head device of the present embodiment has a magnetic shield portion 14 facing the core leg around which the coils of both magnetic heads are wound during the glass removing process of FIG. 11 in the above-described manufacturing process,
You can get it by removing 15 at the same time.

[Fourth Embodiment] FIG. 14 is a perspective view of a fourth embodiment. In the present embodiment, the magnetic shield portion is omitted, and other aspects are the same as in the above-described embodiment, and it is a composite magnetic head device having a structure composed of only the upper magnetic head and the lower magnetic head, and this aspect is also included in the present invention. In this case, the gap between the magnetic heads is set to such an extent that magnetic interference between the magnetic heads does not pose a practical problem.

[Embodiment 5] In the composite magnetic head devices having the structures described in the first to fourth embodiments, from the viewpoint of improving the productivity, the bobbin around which the coil is wound is inserted into each core leg, and the magnetic field is closed. Although it is based on a method of adhering a prismatic magnetic material to form a path structure, from the viewpoint of improving recording and reproducing efficiency, a structure without an adhesive layer that increases the magnetic resistance of the magnetic circuit,
That is, as shown in the perspective view of the fifth embodiment in FIG. 15, it is preferable to integrally form each core portion so as to form a closed magnetic circuit. In this case, the coil is wound directly.

[Embodiment 6] FIG. 16 is a perspective view of a sixth embodiment. In this embodiment, the upper magnetic head is a wide write narrow read type composite magnetic head, and the lower magnetic head is a tunnel erase type adopted in a FDD of 2 MB or 1 MB. Others are the same as those of the first embodiment. It is a device. By combining the upper and lower layers in this way, a large-capacity FDD that is completely backward compatible with the current 2/1 MB can be realized.

[Embodiment 7] FIG. 17 shows a seventh embodiment.
In this embodiment, in the composite magnetic head device according to the first embodiment, the side of the slider facing the magnetic disk (the shaded portion in the figure) is made of titanic acid having excellent wear resistance from the viewpoint of improving the wear resistance. It is characterized in that a high hardness ceramic material such as barium or calcium titanate is formed by adhesion or sputtering.

[0037]

As described above, according to the present invention, the wide write narrow read type composite head is used for the upper magnetic head and the preceding erasing type composite magnetic head is used for the lower magnetic head. There is an effect that an FDD having a high-density specification that does not require a track servo having a fully backward compatible function with can be realized at low cost. After the slider, the magnetic shield, the upper magnetic head and the lower magnetic head or the magnetic shield, the upper magnetic head, and the lower magnetic head that form the composite magnetic head device are individually manufactured,
The upper magnetic head and the lower magnetic head, which are problematic in the conventional example, are adopted because a manufacturing method is adopted in which the four cores or the three cores are not integrally formed by adhesion or the like, and the same core block is integrally formed using glass bonding technology. There is an effect that a composite magnetic head device which does not cause magnetic interference between the heads and relative positional deviation of the gap between both heads can be obtained at low cost and a highly accurate one.

[Brief description of drawings]

FIG. 1 is a perspective view showing a composite magnetic head device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 3 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 4 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 5 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 6 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 7 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 8 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 9 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 10 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 11 is a perspective view showing a manufacturing process of a composite magnetic head device according to an embodiment of the present invention.

FIG. 12 is a perspective view of a composite magnetic head device according to another embodiment of the present invention.

FIG. 13 is a perspective view of a composite magnetic head device according to another embodiment of the present invention.

FIG. 14 is a perspective view of a composite magnetic head device according to another embodiment of the present invention.

FIG. 15 is a perspective view of a composite magnetic head device according to another embodiment of the present invention.

FIG. 16 is a perspective view of a composite magnetic head device according to another embodiment of the present invention.

FIG. 17 is a perspective view of a composite magnetic head device according to another embodiment of the present invention.

FIG. 18 is a perspective view of a conventional composite magnetic head device.

[Explanation of symbols]

14, 15 Magnetic shield 16 to 19 sliders 30 read / write gap 31 Erase Gap 32 read gap 33 write gap 40-43 Non-magnetic material 76 Lower magnetic head 77 Upper magnetic head 100 core pieces 200 center core piece 300 gap material 400 Non-magnetic material (glass rod) 800 core blocks 900 head block

Claims (4)

[Claims] 1. An upper magnetic head using a wide write narrow read system and a lower magnetic head using a preceding erasing system are arranged in parallel with a non-magnetic body interposed therebetween, and both heads are arranged between sliders. A composite magnetic head device characterized by the above. 2. The composite magnetic head device according to claim 1, wherein a magnetic shield portion is provided between the upper magnetic head and the lower magnetic head via a non-magnetic material. . 3. The composite magnetic head device according to claim 1, wherein a write gap of the upper magnetic head and an erase gap of the lower magnetic head, and a read gap of the upper magnetic head and a read / write gap of the lower magnetic head. A composite magnetic head device characterized in that each is arranged in-line. 4. The slider, the magnetic shield, the upper magnetic head, and the lower magnetic head are not individually formed and then integrally formed, and at least the upper magnetic head and the lower magnetic head among the four members are formed. A method of manufacturing a composite magnetic head device, characterized in that the head is integrally formed from the same ferrite core block by a glass bonding method.