JPS62180507A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve writing efficiency by disposing part of a conductive coil in the gap of a magnetic head. CONSTITUTION:A gap layer 3 is formed by sputtering, etc. on a ferrite substrate 1 and grooves 9 are worked by ion milling, etc. in such a manner that the conductive coil 4 is embedded therein in a desired shape. The grooves are worked in such a position where the conductive coil 4 wound in the position nearest the surface side to face a medium exists in the region of the surface side to face the medium of a ferrite closed magnetic material 2 not worked with the grooves when the ferrite substrate 1 and the ferrite closed magnetic material 2 are stuck to each other. The conductive coil 4 is then formed and is so worked by ion milling, etc. as to have the desired shape. Part of the conductive coil 4 of the magnetic head constituted in the above-mentioned manner exists in the position substantially near the surface to face the medium and therefore, the magnetic head having good writing efficiency is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of Invention □] The present invention relates to a magnetic head comprising a ferrite core and a thin film conductor coil, which improves writing efficiency and simplifies the manufacturing method.

[Background of the invention]

A structure for improving the writing efficiency of a conventional thin film magnetic head is disclosed in Japanese Patent Application Laid-Open No. 55-62523. FIG. 3 is a sectional view of the ring-type thin film magnetic head.

According to this structure, a lower magnetic layer 22 is formed on a substrate 21, and then an insulating layer 23. Conductor coils 24 are formed alternately. At this time, the first insulating layer and the second insulating layer become Herad gap layers. Furthermore, the shape of the conductor coil 24 is different from that of the opposing surface 2.
The width increases as the distance from 6 increases, and thus the cross-sectional area increases sequentially. Next, an upper magnetic layer 25 is formed to complete the magnetic head.

In such a structure, the strength of the magnetic field generated by the magnetic head is almost determined by the width of the conductor coil wound at the position closest to the magnetic recording medium. Even if you increase the size, the write efficiency remains almost the same.

Moreover, the electrical resistance between both ends of the conductor coil 24 can be significantly reduced. Furthermore, in this structure, the distance C between the tip of the conductor coil closest to the medium facing surface and the gap depth Gd=O is as small as several μm or less, resulting in improved writing efficiency. It has advantages. however.

Conductor coil 24 wound at the position closest to the medium facing surface
When a constant recording current is passed through, the current density is the highest, so the taper angle Q of the insulating layer 23 covering the conductor coil 24 is
The larger 1 is, the more the insulating layer 2 covering the side surface of the conductor coil 24 is.
The effective film thickness a of No. 3 decreases, and the gap with the upper magnetic layer 25 narrows, making insulation deterioration more likely to occur and reliability problems more likely to occur. Further, as shown in FIG. 1, a thin film magnetic head having a multilayer structure requires an additional manufacturing process when forming an element, has many factors that cause variations in magnetic head performance, and is likely to cause a decrease in yield.

On the other hand, a structure has also been proposed that simplifies the magnetic head structure and prevents a decrease in yield. An example of this is JP-A No. 5
7-78615, and its outline will be explained with reference to FIG. An insulating layer 37 of alumina is deposited on the portion of the ferrite base 31 where the conductor coil 34 is to be formed using photoringraph and reactive ion etching (to form the head gap portion), and then the insulating layer 37 in the groove is A conductor coil 34 is formed on the insulating layer 37, and finally the ferrite closed magnetic body 32 is bonded to the ferrite base 31 to complete the magnetic head. In such a structure, the apex angle Q' near the magnetic transducer gap has a large effect on the efficiency of the magnetic head, so unless the inclination angle Q, which is the apex angle when machining the groove, is finished with sufficient precision, This causes variations in the performance of the magnetic head, causing a decrease in yield. In order to avoid this, advanced technology and advanced work management are required for groove processing using photoringraph, reactive ion etching, etc. in order to strictly suppress Q.

[Purpose of the invention]

The purpose of the present invention is to improve the writing efficiency without requiring the above-mentioned high precision and manufacturing technology, and to reduce the electrical resistance of the conductor coil to reduce fluctuations in performance and ensure high reliability. An object of the present invention is to provide a magnetic head structure that allows the head to be manufactured easily.

[Summary of the invention]

The present invention provides a magnetic head structure in which a ferrite base and a ferrite closed magnetic body are bonded together, in which at least a part of the conductor coil is disposed within the gap of the magnetic head formed on the ferrite base or the ferrite closed magnetic body. Features. Further, a portion of the conductor coil is disposed within the gap described above, and the cross-sectional area of the conductor coil gradually increases as the distance from the medium facing surface increases.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows a magnetic head structure according to the present invention.

FIG. 2 shows a cross-sectional view. First, Ni has a high specific resistance.
- AQ20. ．． 5in
A gap layer 3 made of 2 etc. is formed by sputtering or the like. Next, the groove 9 for forming the conductor coil is processed by ion milling or the like so that the conductor coil 4 is buried in a desired shape. At this time, when the ferrite base 1 and the ferrite closed magnetic body 2 are bonded together, the conductor coil 4 wound at the position closest to the medium facing surface side Groove at one location, such as in the area of side 10. Next, a conductor coil 4 (for example, Au, Al1.
Cu.

Ag, etc.) is formed by plating, vapor deposition, sputtering, etc. to a thickness equal to or less than that of the gap layer 3 described above (for example, if the gap layer is 1 μm thick, the thickness is 0.8 μm). Next, it is processed into a desired shape by ion milling or the like. At this time, the buried conductor coil 4 may have a shape such that its width increases as it moves away from the medium facing surface 11, and its cross-sectional area gradually increases. Furthermore, there may be a plurality of conductor coils in the region of the medium facing surface side 10 that is not grooved. In this way, a ferrite base 1 having a conductor coil 4 formed thereon so as to be buried within the gap layer 3 is produced.

The other ferrite closed magnetic body 2 is first made of ferrite material into an integrated rod shape separated by a glass layer 7 so as to have the desired track width of the magnetic head, and then cut into a desired thickness to form a plate. The surface to be mated with the ferrite base 1 is finished by lapping, and the grooves 5 and 5' are processed by mechanical grinding or the like. What is the position of this poem 5?

When combined with the ferrite base 1, it is preferable that the conductor coil 4 not face the position closest to the medium facing surface, but be located at a position facing the second and subsequent conductor coils. In this way, the ferrite closed magnetic body 2 is completed.

Next, the ferrite base 1 and the ferrite closed magnetic body 2 are bonded together using an epoxy resin 9 or the like. At this time, as shown in FIG. 2, as described above. It does not matter if the relative position a between the rear end of the conductor coil wound at the position closest to the medium facing side and the apex portion of the ferrite closed magnetic body 2 varies somewhat. The pads 8 and 8', which are part of the conductor coil 4, are provided for connecting wires (not shown) for connection to the magnetic head drive circuit, and the grooves 5' are for connecting the wires. It serves as an escape groove.

Then, the gap depth is processed by one machining process to complete the magnetic head.

In the magnetic head constructed in this way, as shown in FIG. 2, a part of the conductor coil 4 is located sufficiently close to the medium facing surface, so that a magnetic head with good writing efficiency can be obtained. I can do it. moreover.

Since the conductor coil 4 can be easily brought close to the medium facing surface within the magnetic conversion gap, it is possible to obtain a magnetic head with improved writing efficiency.

In addition, the apex angle Q near the magnetic conversion gap can be adjusted by mechanical processing such as grinding.

The apex angle Q and the position of the groove 5 can be precisely machined, and the relative position a between the rear end of the conductor coil and the apex portion shown in FIG. When bonding, even if the dimension 8 in FIG. 2 changes somewhat, the head efficiency will hardly change because the conductor coil is located sufficiently close to the medium facing surface, as described above. Therefore, since the magnetic head configured in this manner does not require advanced manufacturing technology and can be made into a single 1M unit, it is possible to easily manufacture a magnetic head with good writing efficiency, uniform performance, and high reliability. I can do it.

FIG. 5 is a sectional view showing another embodiment of the present invention.

The difference from the embodiment shown in FIG. 2 is that a portion of the conductor coil 4 is disposed within the gap, and as the conductor coil 4 moves away from the medium facing surface, the cross-sectional area of the conductor coil increases sequentially. It is because of the fact that In this structure, in addition to the effect of the embodiment shown in FIG. 2, as the conductor coil 4 moves away from the medium facing surface 11, its width and cross-sectional area gradually increase. , it is possible to significantly reduce the electrical resistance between both ends of the conductor coil 4, it is possible to reduce the amount of heat generated due to the flow of current, and it is also possible to reduce the burden on the drive circuit of the magnetic head. be. FIG. 5 shows a structure in which the width of the conductor coil is gradually expanded from the surface facing the medium and its cross-sectional area is gradually increased. Since the position is characterized by being placed within the above-mentioned gap, if the width of the second and subsequent conductor coils is wider than the width of the nearest conductor coil, the same effect as the structure shown in Fig. 5 can be obtained. Yes, there is no need to gradually increase the J conductor coil width from the second onwards. The structure described above is a structure in which a gap layer □ and a conductor coil are formed on a ferrite substrate, but a structure in which a gap layer or a conductor coil is formed on the ferrite closed magnetic body side can also be used in the same manner as described above. effective.

〔Effect of the invention〕

According to the present invention, since the conductor coil is placed very close to the medium facing surface of the magnetic head, the magnetic field generated by passing a current through the conductor coil can be easily transmitted without leaking to unnecessary places. I! works effectively as a magnetic field for recording on any recording medium, and also during playback. The magnetic flux detected from the body is converted into voltage to a nearby conductor coil.Furthermore, the ferrite closed magnetic body facing the second and subsequent conductor coils counting from the medium facing surface has a groove forming an apex angle Q. 5, the recording magnetic flux generated from the second and subsequent conductor coils is directed toward the tip of the gap without shorting in the second and subsequent conductor coils 4 between the ferrite base 1 and the ferrite closed magnetic body 6. It works effectively, and the same holds true during playback. In this way, a magnetic head with good recording and reproducing efficiency can be obtained.

In addition, the width of the second and subsequent conductor coils is made wider than the width of the conductor coil closest to the surface facing the recording medium (the conductor coils are all connected as shown in Fig. 1) to increase the cross-sectional area of the conductor coil 4. The first structure is that the magnetic field generated by the current flowing through the conductor coil closest to the recording medium has the greatest effect on the magnetic field for recording the medium, and the cross-sectional area is the second conductor coil closest to the medium facing side. Because it is smaller than any of the coils, the current density is the highest when current is passed through it, making it a magnetic head with high recording efficiency.At the same time, it is possible to lower the resistance value of the second and subsequent conductor coils, making it possible to pass current. Since the amount of heat generated by the magnetic head can be reduced, and the current density flowing through the second and subsequent conductor coils can be reduced, migration can be prevented and a highly reliable magnetic head can be obtained.

[Brief explanation of drawings]

FIG. 1(a) is a perspective view of one embodiment of the present invention. (b) is a detailed view of part A, FIG. 2 is a sectional view of an embodiment of the present invention, FIG. 3 is a sectional view of a thin film magnetic head with a conventional structure, and FIG. 4 is a sectional view of a conventional ferrite core + thin film coil structure. 5 is a sectional view showing another embodiment of the present invention. 1... Ferrite base, 2... Ferrite closed magnetic body, 3...-head gap layer, 4, 24.34...
...Conductor coil, 5.5', 9...Groove, 21...
...Substrate, 22...F section magnetic layer, 25...Top magnetic layer, 11, 26, 37...Medium facing surface, 23.
...Insulating layer, 6...Resin layer, 7...Glass layer. 5th flash

Claims (1)

[Claims] 1. A magnetic head having a ferrite base and a core piece of ferrite closed magnetic material, characterized in that at least a part of a conductor coil is embedded within a conversion gap that constitutes the magnetic head.