JPH054088Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an improvement in the structure of the tip of a vertical thin film magnetic head, particularly an auxiliary magnetic pole film, in a perpendicular magnetic recording device.

[Conventional technology]

5 to 8 show conventional vertical thin film magnetic heads, in which 1 is a nonmagnetic substrate made of Al ₂ O ₃ -TiC, sapphire, etc., 2 is a main pole film, and _CO
It has a main magnetic pole film 2' having a high saturation magnetic flux density and high magnetic permeability made of _-Zr- based amorphous alloy or the like, and a main magnetic pole film thickened portion 2'' made of permalloy or the like.
3 is a coil made of Cu, Al or the like, and 4 is an auxiliary magnetic pole film made of permalloy or the like, the tip surface 4a of which is set back by a dimension H from the medium sliding surface M. 5 is Al ₂
Interlayer insulating layer and protective layer made of O ₃ , SiO ₂ etc.
6 is a perpendicular magnetization film made of Co-Cr or the like, and 7 is a high magnetic permeability layer made of permalloy or the like.
Together with this, they constitute a two-layer medium. T is the track center line, Tw is the track width, and Aw is the auxiliary magnetic pole film 4.
The tip width, d, d ₁ is the width of the main magnetic pole film 2 and the auxiliary magnetic pole film 4.
This is the layer spacing.

A conventional vertical thin film magnetic head is constructed as described above, and the magnetic flux normally passes from the main pole film 2 to the auxiliary pole film 4 as shown by the arrow in FIG. It flows into the high permeability film 7 of the layered medium.

Here, the reason why the tip surface 4a of the auxiliary magnetic pole film 4 is set back by the dimension H from the medium sliding surface M is because the magnetic flux flows into the tip of the auxiliary magnetic pole film 4 near the main magnetic pole film 2, which is indicated by the symbol A in FIG. This is to prevent unnecessary signals from being recorded or reproduced.

[Problem that the invention attempts to solve]

In the conventional vertical thin film magnetic head as described above, as shown in FIG. 8, when the layer spacing between the main magnetic pole film 2 and the auxiliary magnetic pole film 4 becomes small as indicated by the symbol _d1 , it becomes smaller as indicated by the symbol B in the figure. The perpendicular component (y-direction component) of the magnetic flux near the tip of the main pole film 2 and the perpendicularly magnetized film 6 shown in the figure tends to decrease, and the longitudinal component (z-direction component) tends to increase. Furthermore, since the leakage magnetic flux between the main magnetic pole film 2 and the auxiliary magnetic pole film 4 also increases, there is a problem that recording and reproducing efficiency decreases.

As shown in FIG. 7, if the layer spacing between the main magnetic pole film 2 and the auxiliary magnetic pole film 4 is increased as indicated by the symbol d, the above problem does not occur, but as the film thickness increases, the thin film head In the manufacturing process, there are problems such as an increase in film formation time, a decrease in pattern accuracy due to a high level difference, and difficulty in processing.Also, as the stress of the film increases, the magnetic properties of the main pole film 2 may deteriorate. There are also problems.

This invention was made to solve this problem, and even when the layer spacing between the main pole film and the auxiliary pole film is small, the leakage magnetic flux between the main pole film and the auxiliary pole film is reduced. Vertical thin film magnetic that can prevent the vertical component of the magnetic flux from decreasing at the tip of the main pole film, and the area of the tip of the auxiliary pole film can be increased to reduce magnetic resistance in this area, improving recording and reproducing efficiency. The purpose is to gain head.

[Means for solving problems]

In the perpendicular thin film magnetic head according to this invention, the auxiliary magnetic pole film is formed by branching into two in the track width direction from a position directly above or directly below the main magnetic pole film toward the medium sliding surface, and the auxiliary magnetic pole film At least the tip portion of the auxiliary magnetic pole film is shifted from the position directly above or directly below the main magnetic pole film in the track width direction without overlapping with the surface of the main magnetic pole film, and the dimensions of both tip surfaces of the auxiliary magnetic pole film in the track width direction are The sum of these is greater than the track width.

[Effect]

In this invention, since it has the above configuration,
The distance between the main magnetic pole film and the auxiliary magnetic pole film can be increased even if the layer spacing is reduced, and the area of the tip surface of the auxiliary magnetic pole film can be increased to reduce its magnetic flux density and magnetic resistance, resulting in improved recording and reproducing efficiency. It is possible to improve the

〔Example〕

Figures 1 and 2 show an embodiment of this invention. In the figures, the same reference numerals as in Figures 5 to 8 indicate the same or corresponding parts, and 4' and 4'' are media sliding surfaces. M
The leading end of the auxiliary magnetic pole film is divided into two parts in a v-shape toward
4", and is located offset in the track width direction from the position directly above the main pole film 2. H ₁ and H ₂ are located from the medium sliding surface M of each of the above-mentioned end surfaces 4'a and 4"a. The amount of retraction, Aw ₁ and Aw ₂ are the tip widths of the auxiliary magnetic pole film tips 4' and 4'', and the total width Aw = Aw ₁ +
Aw ₂ is set larger than the track width Tw. θ ₁ and θ ₂ are the angles formed between the tip portions 4' and 4'' of each auxiliary magnetic pole film and the track center line T, and x ₁ and x ₂ are the track center lines at the inner end of each tip surface 4'a and 4''a. The distance from T in the track width direction, and both are set to a value larger than Tw/2.

In the vertical thin-film magnetic head configured as above, the distances x ₁ and x ₂ are both
Since the value is set to be larger than Tw/2, the tip surfaces 4'a and 4''a of each auxiliary magnetic pole film tip portion 4' and 4'' are completely shifted from the upper part of the main magnetic pole film 2 in the track width direction. , the layer spacing between the main pole film 2 and the auxiliary pole film 4
Even if d ₁ is small, each auxiliary magnetic pole film tip 4',
4'' and the main magnetic pole film 2 can be made large.Therefore, there is no problem such as that which occurs in the conventional magnetic head described in FIG. 8.

Also, the tip width of each auxiliary magnetic pole film tip 4', 4''
Since the total width Aw of Aw ₁ and Aw ₂ is set larger than the track width Tw, the tip surfaces 4′a, 4″a
The area increases and the magnetic flux density decreases, making it possible to prevent unnecessary signals from being recorded and reproduced in this area, and also to reduce magnetic resistance and improve recording and reproduction efficiency.

By the way, in order to increase the distance between the main magnetic pole film 2 and each auxiliary magnetic pole film tip 4', 4'', the distance x ₁ , x ₂
It is necessary to make the distances x 1 and x 2 as large as possible, but if the distances x ₁ and x ₂ are too large, the angles θ ₁ and θ ₂ will become large, and when using a magnetic film with magnetic anisotropy, the magnetic permeability in that direction tends to decrease, and the magnetic path length also increases, so the magnetic resistance increases,
There is a risk that recording/reproducing efficiency will decrease. Therefore, in use, it is preferable to set the optimum value in consideration of the above points.

Figure 3 shows another embodiment of this invention.
The tip surface 4'a of each auxiliary magnetic pole film tip 4', 4'',
4"a is inclined with respect to the medium sliding surface M, and the recess amount H' ₂ of the outer end is compared to the retraction amount H' ₁ , H" ₁ of the inner end.
According to FIG. ₃ , the magnetic resistance of the magnetic circuit including the magnetic head and the medium is almost constant regardless of the magnetic path, and the tip surfaces 4'a, 4 ``The magnetic flux density of a can be made constant at various locations,
The entire magnetic pole film can be used efficiently.

FIG. 4 shows still another embodiment of this invention, in which the tips 4', 4'' of each auxiliary magnetic pole film are inclined in the track width direction with respect to the main magnetic pole film 2. According to FIG. 4, since the azimuth angle is set, it is possible to prevent unnecessary signal reproduction at the tips of the respective auxiliary magnetic pole film tip portions 4', 4''. In this case, the auxiliary magnetic pole film tip 4',
The tip surfaces 4'a, 4''a of the 4'' may be exposed to the medium sliding surface M. In other words, the amount of retreat can be made zero.

In each of the above embodiments, the magnetic poles have a symmetrical shape with respect to the track center line (T), but they may have an asymmetrical shape, and the magnetic pole shape is not limited to a straight line, but may be curved.

Furthermore, the perpendicular thin film magnetic head according to this invention is not limited to a magnetic induction type using a coil, but can also be applied to a type using a magnetoresistive (MR) element, etc. This is also effective when the membrane 4 is upside down.

[Effect of idea]

According to this invention, as described above, the auxiliary magnetic pole film is formed so as to branch into two branches in the track width direction toward the medium sliding surface from a position directly above or below the main magnetic pole film. At least the tip of the magnetic pole film is shifted from the position directly above or directly below the main magnetic pole film in the track width direction without overlapping the surface of the main magnetic pole film, and the track width of both tip surfaces of the auxiliary magnetic pole film is Since the sum of the directional dimensions is configured to be larger than the track width, even if the layer spacing between the main pole film and the auxiliary pole film is small, leakage magnetic flux between the two pole films can be reduced. It is possible to prevent the vertical component of the magnetic flux at the tip of the main pole film from decreasing.
In addition, the area of the tip surface of the auxiliary magnetic pole film can be increased to reduce its magnetic flux density and magnetic resistance.
It is possible to improve recording and reproducing efficiency.

[Brief explanation of drawings]

Fig. 1 is a plan view of a vertical thin film magnetic head showing one embodiment of this invention, Fig. 2 is a sectional view thereof, Fig. 3 is a view corresponding to Fig. 1 showing another embodiment of this invention, and Fig. 4 5 is an explanatory view showing still another embodiment of this invention, FIG. 5 is a view corresponding to FIG. 2 showing a conventional vertical thin film magnetic head, FIG. 6 is a plan view of FIG. 5, and FIGS. 7 and 8. 2A and 2B are explanatory diagrams showing the relationship between the layer spacing between the main pole film and the auxiliary pole film and the flow of magnetic flux, respectively. 2...Main magnetic pole film, 4...Auxiliary magnetic pole film, 4',
4''...Auxiliary magnetic pole film tip, 4'a, 4''a...Tip surface, M...Medium sliding surface, Tw...Track width,
Aw...Total width, Aw ₁ , Aw ₂ ...Tip width, H ₁ ,
H ₂ , H′ ₁ , H′ ₂ , H″ ₁ , H″ ₂ ... Retraction amount. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims for Utility Model Registration] (1) In a vertical thin film magnetic head having a main magnetic pole film and an auxiliary magnetic pole film, the auxiliary magnetic pole film faces toward the medium sliding surface from a position directly above or directly below the main magnetic pole film. Once formed into two branches in the track width direction, at least the tip of the auxiliary pole film is shifted in the track width direction from a position directly above or directly below the main pole film without overlapping with the surface of the main pole film. 1. A perpendicular thin-film magnetic head, characterized in that the auxiliary magnetic pole film is positioned at the same angle as the auxiliary magnetic pole film, and the sum of the dimensions in the track width direction of both end surfaces of the auxiliary magnetic pole film is larger than the track width. (2) The vertical thin film magnetic head according to claim 1, wherein the tip end surface of the auxiliary magnetic pole film is set back from the medium sliding surface by a required amount. (3) The vertical thin film magnetic head according to claim 2, wherein the amount of retraction of the leading end surface of the auxiliary magnetic pole film from the medium sliding surface changes in the track width direction. (4) The vertical thin film magnetic head according to any one of claims 1 to 3, wherein the auxiliary magnetic pole film is inclined in the track width direction with respect to the main magnetic pole film.