JPH01296418A - Thin film magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To set a track width smaller with high accuracy by alternately repeating a magnetic layer forming stage and a photolithographic etching stage so that the width is narrowed stepwise in the track width direction nearer the magnetic gap. CONSTITUTION:Lower and upper coil conductors 3, 4 consisting of a conductive layer are provided via an insulating layer to a lower magnetic material 2 on a substrate 1 and further, an upper magnetic material 7 consisting of the magnetic layer is so provided as to bestride a coil; in addition, the front end thereof faces the magnetic material 2 via a gap 5 and the rear end part is joined to said material by a back gap 6. The magnetic material 7 is formed to a large thickness and the track width W can be set with the high accuracy by stepwise laminations 71-73 to the sizes increased successively in the track width direction by the method of alternately repeating the magnetic layer forming stage and the photolithographic etching method or by the method consisting of one time of the magnetic layer forming stage and plural times of the photolithographic etching stage. The high density of recording and the higher efficiency of recording and reproduction are thus obtd.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic head for magnetically recording or reproducing information on a magnetic recording medium and a method for manufacturing the same. The present invention relates to a thin film magnetic head, at least one of which is configured as a thin film magnetic layer, and a method for manufacturing the same.

[Prior Art] In general, in a thin film magnetic head, at least one of two magnetic bodies constituting a magnetic circuit and a coil are formed as a magnetic layer and a conductive layer, respectively, by vacuum thin film forming techniques such as sputtering, vapor deposition, and ion blating. It has the advantage of being excellent in mass production, and because patterning is performed using photolithography technology, a head with uniform characteristics can be obtained. Furthermore, in this type of thin-film magnetic head, the generated magnetic field involved in recording becomes steep, making it possible to perform high-density recording and high-resolution recording.

FIG. 6 shows an example of the structure of a conventional thin film magnetic head, in which a lower magnetic body 2 formed as a magnetic layer from a soft magnetic material such as sendust is provided on a substrate 1 made of glass, ferrite, etc. Then, S i on the lower magnetic body 2
A lower coil conductor 3 made of a good conductor is formed through an insulating layer (not shown) made of 02 or the like, and an upper coil conductor 4 is further provided on this with an insulating layer (not shown) interposed therebetween. A coil is formed by both coil conductors 3.4. In order to simplify the illustration, the number of turns of the coil is assumed to be one, but normally a plurality of turns of the coil are provided. Furthermore, an upper magnetic body 7 made of a magnetic layer is formed on the lower magnetic body 2 via an insulating layer (not shown) so as to straddle the coil conductor 3.4.

The leading end of the upper magnetic body 7 faces the lower magnetic body 2 through a magnetic gap (front gap) 5, and the width W of the facing portion becomes the track width for recording and reproduction. Further, the rear end portion of the upper magnetic body 7 straddles the coil conductor 3.4 and is joined to the lower magnetic body 2 at the back gap 6 through a contact hole formed in an insulating layer (not shown).

In the manufacturing process of such a thin-film magnetic head, contact holes and the like in the above-mentioned insulating layer are processed by reactive etching using, for example, a fluorine-based gas.
The magnetic material 2.7 and the coil conductor 3.4 are processed by, for example, ion beam etching using Ar.

In such a thin film magnetic head, during recording and reproduction, a magnetic recording medium (not shown) slides in the direction of arrow A or the opposite direction with the front surface in the figure serving as a magnetic recording medium sliding surface S. During recording, a recording signal current is applied to the coil consisting of the coil conductor 3.4, and by excitation of the coil, magnetic flux corresponding to the recording signal flows through the magnetic body 2.7, and the magnetic recording medium is magnetized by the magnetic flux leaking through the magnetic gap 5. Ru. Also, during reproduction, magnetic flux corresponding to the magnetization of the track of the magnetic recording medium is picked up from the magnetic gap 5 and flows into a magnetic circuit consisting of both magnetic bodies 2.7, and a reproduction output voltage corresponding to the change in magnetic flux is excited in the coil. Ru.

[Problems to be Solved by the Invention] In recent years, as the density of magnetic recording has increased, thin-film magnetic heads have also become narrower in track and gap.
In particular, increasing track density (number of tracks per unit length) is being considered. In addition, in magnetic recording media, there is a growing trend to use high coercivity media in order to shorten the recording wavelength and increase linear recording density.

On the other hand, in the conventional thin film magnetic head as shown in FIG. 6, the following problems were encountered when trying to narrow the track by reducing the track width W.

That is, when processing the upper magnetic body 7 by etching to obtain the track width W in the head shown in FIG. 6, the ratio of the thickness to the width of the upper magnetic body 7, so-called aspect ratio, is large, so the thickness must be 10 μm in particular. If it is too thick, it becomes very difficult to control the width dimension. In other words, it becomes difficult to control the track width dimension. On the other hand, if the thickness of the magnetic layer of the upper magnetic body 7 is made thinner in order to lower the aspect ratio, the recording/reproducing efficiency of the head will decrease, especially for high coercivity media. As described above, with conventional thin film magnetic heads, it has become difficult to realize a narrow track while maintaining the necessary and sufficient thickness of the magnetic material.

Therefore, the object of the present invention is to make it thin enough to achieve a narrow track and to obtain good recording and reproducing efficiency! An object of the present invention is to provide a 6B air head and a method for manufacturing the same.

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, in the above-mentioned type of thin film magnetic head, at least one of the two magnetic bodies constituting the magnetic circuit is used for magnetic recording of the thin film magnetic head. We adopted a structure in which the width in the track width direction becomes smaller as it approaches the magnetic gap in a cross-sectional shape cut along a plane approximately parallel to the sliding surface of the medium, and is formed in a shape with steps so that the width becomes smaller in stages. .

Further, depending on the method of manufacturing the thin II@61-metal head of the present invention, at least one of the above-mentioned magnetic materials may be formed by alternately repeating the magnetic layer forming process and the photolithography process multiple times, or by repeating the process once and for all. The magnetic layer is formed by a method of forming a magnetic layer and a plurality of photolithographic etching steps, and in this case, the magnetic layer is formed in stages by gradually increasing the track width direction of the processed magnetic layer.

[Function] According to the configuration of the present invention as described above, at least one of the magnetic bodies constituting the magnetic circuit is formed stepwise by a plurality of photolithographic etching steps, and in that case, the magnetic material forming the magnetic circuit is formed stepwise by a plurality of photolithographic etching steps. Since the aspect ratio is much smaller than when the entire magnetic material is processed in one photolithography process, the width of the magnetic material in the track width direction can be easily set small with high accuracy.

[Example] Hereinafter, details of embodiments of the present invention will be described with reference to the drawings.

In each figure of the embodiment, the same reference numerals are given to parts common or equivalent to those in FIG. 6 of the conventional example.

First Embodiment FIG. 1 explains the structure of a thin film magnetic head according to a first embodiment of the present invention, and shows the structure of the thin film magnetic head with the protective plate and insulating layer removed.

As shown in FIG. 1, the basic structure of the thin film magnetic head of this embodiment is almost the same as that of the conventional example described above, in which a lower magnetic body 2 as a magnetic layer itself is provided on a substrate 1; A lower coil conductor and an upper coil conductor 4 constituting a coil made of a conductive layer are provided on 2 with an insulating layer interposed therebetween, and an upper magnetic body 7 made of a magnetic layer is further provided on the lower part with an insulating layer (not shown) interposed therebetween. It is provided on the magnetic body 2 so as to straddle the coil. The tip of the upper magnetic body 7 faces the lower magnetic body 2 through the magnetic gap 5, and the rear end of the upper magnetic body 7 is joined to the lower magnetic body 2 through the pack gap 6 via a contact pole (not shown). Ru. The width in the track width direction of the lower surface of the tip of the upper magnetic body 7 that faces the lower magnetic body 2 through the magnetic gap 5 is the recording track width W. Note that a protection plate (not shown) is adhered onto all of these through a protection layer (not shown).

By the way, the thin lIM magnetic head of this embodiment differs from the conventional one in that the upper magnetic body 7 is formed by laminating three magnetic layers 71 to 73, as shown by the broken line in the figure.

The width of each of the magnetic layers 71 to 73 in the track width direction becomes smaller as it approaches the magnetic gap 5, and the width of the magnetic layer closer to the magnetic gap 5 becomes smaller. As a result, the cross-sectional shape of the upper magnetic body 7 taken along a plane parallel to the medium sliding surface S becomes a three-step inverted trapezoid with a two-step difference, and the closer it gets to the magnetic gap 5, the more The width is small, and the width is gradually becoming smaller.

Next, a method of manufacturing the thin film magnetic head of this embodiment will be explained.

First, a magnetic layer made of a soft magnetic material such as sendust is deposited as the lower magnetic material 2 on a substrate 1 made of glass or the like, and an insulating layer (not shown) made of 5i02 or the like is deposited thereon.

Next, a conductive layer made of Cu, Al, etc. is deposited and processed into the pattern of the lower coil conductor 3 by a photolithography process. After depositing an insulating layer (not shown) thereon, the upper coil conductor 4 is formed in the same manner.

Next, an insulating layer (not shown) is deposited on the coil conductor 4, and then the upper magnetic body 7 is formed. In this embodiment, the magnetic layer deposition process and the photolithography process are alternately repeated three times. An upper magnetic body 7 is formed. This is done as shown in FIGS. 2(A) to 2(G) when looking toward the medium sliding surface S.

That is, first, as shown in FIG. 2(A), an insulating layer 11 is deposited on the lower magnetic body 2, and then a concave groove 11a is formed on the magnetic gap (front gap) 5 side by a photolithography process.
A contact hole (not shown) is formed in the back gap 6 portion.

At this time, if the thickness of the insulating layer 11 is made as thin as possible, the processing accuracy will be improved, but the insulation property will be reduced, so the thickness is 0.5 to 2 μm.
Good condition.

Next, as shown in FIG. 2(B), a nonmagnetic layer 12 serving as a spacer for the magnetic gap 5 is deposited only in the region of the magnetic gap 5 to a suitable thickness determined by the wavelength of the reproduced signal. Here, as shown in the figure, the track width W of the head is defined by the width in the track width direction of the lower surface of the concave groove 11a after the nonmagnetic layer 12 is formed.

Next, as shown in FIG. 2(C), a magnetic layer 71 made of a soft magnetic material such as Sendust is deposited as the first layer of the upper magnetic material 7, and then a photolithography process is performed as shown in FIG. 2(D).
The magnetic layer 71 is patterned to have a shape that is embedded in the concave groove 11a and that connects the concave groove 11a to the contact hole on the back gap 6 side.

Next, as shown in FIG. 2(E), an insulating layer 13 is deposited to a thickness of about 2 μm, and a direction in the track width direction is formed from the concave groove 11a previously formed and the contact hole on the back gap 6 side. It is formed directly above the second concave groove 13a having a slightly larger width and the magnetic layer 71 which is a contact hole (not shown). Is it already the first concave shape at this time? Since the track width W is determined via *11a, the dimensional accuracy of the second concave groove 13a is not a major problem.

Next, as shown in FIG. 2(F), a second magnetic layer 72 is deposited and patterned by photolithography in the same manner as the first magnetic layer 71, so as to fill the concave grooves 13a. .

Next, as shown in FIG. 2(G), a third insulating layer 14 is formed in the same manner, and a concave groove 14a having a large width in the track width direction and a contact hole (not shown) are formed.
The upper magnetic layer 73 is deposited and processed by photolithography so as to be buried in the concave groove 14a, thereby completing the upper magnetic layer 7 of FIG. Then, a protective layer (not shown) is formed on this, and a protective plate (not shown) is bonded thereon to complete a thin film magnetic head.

According to this embodiment, the upper magnetic body 7 is formed by alternately performing a magnetic layer deposition step and a photolithography etching step.
The aspect ratio in the photolithography process for each photolithography is set by
Since the size is significantly smaller than when the entire structure is processed by one photolithography, the width dimension of the magnetic layer in the track width direction can be easily controlled with high precision.

Therefore, the track width of the head corresponding to the width in the track width direction of the lower surface of the first magnetic layer 71 can be set to be small with extremely high precision, making it possible to narrow the track and achieve higher recording density. Further, since the overall thickness of the upper magnetic body 7 does not affect the accuracy of the track width, the thickness of the upper magnetic body 7 can be increased, and the efficiency of recording and reproduction can be improved.

Furthermore, since the width of the upper magnetic body 7 becomes smaller as it approaches the magnetic gap 5, the magnetic flux converges on the magnetic gap 5 during recording, and from this point as well, the efficiency of recording and reproduction can be improved.

Second Embodiment Next, FIG. 3 shows the structure of a thin film magnetic head according to a second embodiment of the present invention. As shown in the figure, in this embodiment, the upper magnetic body 7 is the same as in the conventional example, and the lower magnetic body 2 is replaced instead.
The cross-sectional shape corresponds to the shape of the partially magnetic body 7 of the first embodiment, and is formed upside down. That is, the cross-sectional shape of the lower magnetic body 2 taken along a plane parallel to the medium sliding surface S is a three-step trapezoid with a two-step difference, and the magnetic gap 5
The width in the track width direction becomes smaller as the track approaches , and becomes smaller stepwise through steps. However, unlike the upper magnetic body 7 of the first embodiment, the lower magnetic body 2 of this embodiment is formed from a single magnetic layer.

The lower magnetic body 2 of this embodiment is formed as follows in the steps shown in FIGS.

That is, first, as shown in FIG. 4(A), a magnetic layer 20 for forming the lower magnetic body 2 is deposited on the substrate 1 to a thickness corresponding to the entire thickness of the lower magnetic body 2. A photoresist pattern 31 having a width in the track width direction or corresponding to the track width W and having a shape corresponding to the lower magnetic body 2 is formed thereon by a photolithography process.

Next, the upper surface of the magnetic layer 20 is etched by several μm, and then the photoresist pattern 31 is removed. This state is shown in Figure 4 (
B). As shown in the figure, the uppermost portion 21 of the lower magnetic body 2 is formed on the upper surface of the magnetic layer 20. The width of the upper surface of the uppermost step portion 21 in the track direction is the track width W.

Next, through a photolithography process, the width of the lower magnetic body 2 in the track direction is slightly larger than the track width W, as shown in FIG. 4(C).
Photoresist pattern 3 having a shape corresponding to the shape of
2 is formed on the magnetic layer 2o so as to cover the uppermost part 21,
Thereafter, the magnetic layer 20 is etched several μm and the photoresist pattern 32 is removed. As a result, as shown in FIG.
2 is formed.

Then, repeat the same process one more time, as shown in Figure 4 (E
) A photoresist pattern 33 with a wider width as shown in FIG.
By forming and removing the photoresist pattern 33 by etching, the third step portion 23 of the lower magnetic body 2 is formed as shown in FIG. 4(F), and the lower magnetic body 2 is completed.

After this, as shown in FIG. 4(G), an insulating layer 51 is placed on the substrate 1.
The head of this embodiment is completed by depositing the lower magnetic material 2, embedding the lower magnetic material 2, and forming the above-described coil, upper magnetic material 7, etc. thereon.

According to this embodiment, the lower magnetic body 2 that defines the track width W of the head is formed by three photolithographic etching steps, and the aspect ratio in each step becomes smaller. As in the case of , the track width W can be set to be small with extremely high precision, and the track width can also be narrowed and recording density can be increased. In addition, in this embodiment, the magnetic layer deposition step for forming the lower magnetic body 2 is performed in step 1.
Since only one step is required, there is an advantage that the entire process is simpler than in the case of the first embodiment.

Third Embodiment By the way, recent trends include higher density magnetic recording and faster transfer speeds, and one way to counter this is to increase the track density by increasing the number of channels.

On the other hand, for example, the head of the first embodiment described above has a fifth
As shown in the figure as a third embodiment, multi-channeling is possible. Here, a two-channel configuration is shown for simplicity. On a lower magnetic body 2 provided as a magnetic layer itself on a substrate 1, two sets of coil conductors 3.4 and an upper magnetic body 2 similar to those shown in FIG. 1 are arranged in parallel in the track width direction to form two recording/reproducing channels. It consists of

This head can be manufactured using a manufacturing method equivalent to the thin film IC process in exactly the same way as in the first embodiment, and can easily realize multi-channeling. Since the track width is formed by repeating the magnetic layer deposition process and the photolithography process multiple times, the track width can be set extremely small, and the track width can also be narrowed, thereby increasing the recording density. Similarly, since the thickness of the upper magnetic body 7 can be increased, high recording and reproducing efficiency can be obtained.

Although an example in which the head of the first embodiment is made multi-channel is shown here, the structure of the head of the second embodiment is similarly composed of both magnetic materials 2.7 and coil conductors 3.4 on the substrate 1. Of course, a plurality of head elements can be arranged in parallel to provide multichannel. When the head of the second embodiment is made into a multi-channel head, the same effect can be obtained, and since the lower magnetic body 2 is no longer common to each channel, there is an advantage that crosstalk with adjacent tracks can be reduced.

Summer Solstice Next Summer 1 Next, as a fourth embodiment of the present invention, the first embodiment and the second embodiment are combined, and the upper magnetic body 7 is that of the first embodiment,
The lower magnetic body 2 of the second embodiment can also be made to have the same track width and overlaid with high precision to form a thin film magnetic head. According to such a structure, the degree of convergence of magnetic flux during recording and reproduction is further increased than in each of the embodiments described above, and the recording and reproduction efficiency can be further improved. Further, since the widths of both the lower magnetic body 2 and the upper magnetic body 7 become narrower toward the magnetic gap 5, leakage of magnetic flux from both sides of the magnetic gap can be reduced, and crosstalk with adjacent tracks can be further reduced.

It goes without saying that even with such a structure, multi-channeling can be easily realized as in the case of the third embodiment.

In each of the above embodiments, in order to obtain good recording and reproducing efficiency, it is preferable that the thickness of the upper magnetic body F or the lower magnetic body 2 formed in a trapezoidal cross-sectional shape with steps is larger than the track width W. .

Even if the thickness is increased in this way, the track width can be set small with high precision by the above manufacturing method.

[Effects of the Invention] As is clear from the above description, according to the thin film magnetic head according to the present invention, at least one of the magnetic bodies constituting the magnetic circuit has a cross-sectional shape cut along a plane substantially parallel to the medium sliding surface of the head. The width in the track width direction becomes smaller as it approaches the magnetic gap, and the structure is formed in a stepwise shape so that the width becomes smaller stepwise.The method for forming the magnetic material is as follows: The magnetic layer is formed by a method of repeating alternating and photolithographic etching processes several times, or by a method of one magnetic layer forming process and a plurality of photolithographic etching processes, in which case the width of the magnetic layer to be processed in the track width direction is sequentially increased. Therefore, the track width can be set small with extremely high precision, narrowing the track, and increasing the recording density. Further, the excellent effect of increasing the thickness of the magnetic material and improving the recording and reproducing efficiency can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of a thin film magnetic head according to a first embodiment of the present invention, and FIGS. 2 (A) to (G) are steps for forming an upper magnetic body in the manufacturing process of the thin film magnetic head of the same embodiment. 3 is a perspective view showing the structure of a thin film magnetic head according to the second embodiment, and FIGS. 4(A) to 4(G) respectively show the formation process of the lower magnetic body in the manufacturing process of the head of the same embodiment. FIG. 5 is a perspective view showing the structure of a multi-channel thin film magnetic head according to the third embodiment, and FIG. 6 is a perspective view showing the structure of a conventional thin film magnetic head. 1... Substrate 2... Lower magnetic body 3...
Lower coil conductor 4... Upper coil conductor 5... Magnetic gap 6... Back gap 7... Upper magnetic body 11.13,14. ...Insulating layer 12...Nonmagnetic layer 20.71-73...Magnetic layer (B) □ii F (C) (D) Fig. 2 (A) (E) (B) (C) ( D) (F) In the lower part or in the shape of a tool, the fortune-teller scolding figure 4, Au's Yū I Gunshin, the y's hand, the battle figure 6.

Claims (1)

[Scope of Claims] 1) It has a magnetic circuit composed of two magnetic bodies made of at least thin film magnetic layers facing each other with a magnetic gap therebetween, and a magnetic recording medium is slid into the gap to record information. In a thin film magnetic head that performs magnetic recording or reproduction, at least one of the magnetic bodies has a cross-sectional shape taken along a plane substantially parallel to the sliding surface of the magnetic recording medium of the thin film magnetic head, and the width in the track width direction increases as it approaches the gap. 1. A thin film magnetic head characterized in that it is formed in a shape having steps that become smaller and stepwise smaller. 2) The thin film magnetic head according to claim 1, wherein the thickness of the magnetic body formed in the stepped cross-sectional shape is larger than the track width. 3) A plurality of head elements constituted by the coil and a magnetic circuit made of two magnetic bodies are arranged in parallel in the track width direction on the substrate, according to claim 1 or 2. thin film magnetic head. 4) The step of forming a magnetic body consisting of a magnetic layer constituting the magnetic circuit of a thin-film magnetic head on a substrate is a step of depositing and forming a magnetic layer, and processing the magnetic layer formed by this step into a predetermined shape. Manufacturing a thin-film magnetic head characterized by comprising a step of forming the magnetic material stepwise by repeating the photolithography etching step alternately multiple times, in which case the width of the magnetic layer to be processed in the track width direction is sequentially increased. Method. 5) The process of forming a magnetic material consisting of a magnetic layer constituting the magnetic circuit of a thin-film magnetic head on a substrate includes a process of depositing and forming a magnetic layer, and a process of photolithography of the magnetic layer formed by this process multiple times. Manufacturing a thin-film magnetic head characterized by the step of processing it into a predetermined shape by repeated etching, and in that case, gradually increasing the width of the processed magnetic layer in the track width direction to form the magnetic material in stages. Method.