JPS60202502A - Magnetic head - Google Patents

Abstract

PURPOSE:To decrease the output wave due to a contour effect by inserting a magnetic alloy film between a substrate and another magnetic alloy film so that the permeability is increased gradually toward a gap from the substrate side. CONSTITUTION:Alloy films 8 and 8' having large permeability are laminated at positions more outside than other alloy films 7 and 7' of small permeability, i.e., at the side of a gap 3. In addition, the manufacturing process is simplified with reduction of the cost since no special technique is needed excepting for production of those alloy films. Thus, the reliability of a magnetic head is improved.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a magnetic head.

[Prior art]

One of the output characteristics of a magnetic head during playback is output undulation due to the Hunter effect, and the factors that cause this are:
It depends on the core width of the magnetic head and the wavelength λ, and is expressed by the general formula: FIG. 1 shows the results of calculations using Equation 11, and FIG. 2 schematically shows the relationship between the magnetic head h1 and the magnetic recording medium t at that time.

From this table relationship, if it is a conventional magnetic head of the type in which a bulk magnetic core is wound (hereinafter referred to as bulk-wound type), for example, the magnetic recording medium of magnetic head h in FIG. The influence of the contour effect can be reduced by cutting the back part of the sliding contact surface at a 45 degree angle and improving the shape of the sliding contact surface as shown in the magnetic head h shown in Figure (b). can. FIG. 3 shows this together with a comparative example.

That is, curve D1 and curve D in FIG.
The magnetic head h shown in FIG. 4(a) has a core width of 6 m++, and the magnetic head h shown in FIG. 4(b).

This is a comparison of the contour effect when both shoulders are cut at 45 degrees and the core width is 3 mm. As is clear from this, by making the magnetic recording medium gradually move away from the magnetic head as it moves away from the gap, the amplitude of the output undulation due to the Hunter effect can be reduced as shown in FIG.

Based on these facts, it has been necessary to consider how to change the shape of the sliding surface of the magnetic head with the tape in order to reduce the influence of the contour effect. It is as a result of such studies that in bulk-wound magnetic heads, the influence of the shikon-yaw effect is improved by chamfering the sliding surface of the magnetic head with the tape.

However, the high permeability magnetic alloy film 2 as shown in FIG.
In a magnetic head formed by bonding a pair of non-magnetic substrates 1.1' with a metal alloy film 2' formed thereon with an organic or inorganic adhesive with a gap material 3 provided between the opposing alloy film 2.2', Since the magnetic alloy films 2 and 2' are extremely thin, the above-mentioned prior art has a problem in that it is not possible to reduce the amplitude of output waviness due to the influence of the contour effect. Note that 4 is a winding wire.

That is, in the magnetic head shown in FIG.
Since the length of the sliding contact surface with the tape, which is a magnetic recording medium, is extremely small, even if this part is chamfered, the core shape will not look microscopically good. There was a problem that the contour effect could hardly be expected to be improved due to the flat surface.Therefore, in order to solve this problem, the following methods have been adopted, for example. . This method is an extension of the prior art method.

(1) The thickness D of the core at the sliding surface of the magnetic head with the tape is increased, and the distance between the tape sliding surface and the tape gradually increases as the distance from the gap increases.

(2) As shown in FIG. 6 (same representation as in FIG. 5, and corresponding parts are given the same reference numerals), the shoulder of the core of the magnetic head is cut to form an acute angle, The cut surface is covered with non-magnetic metals 5 and 5' so that the core appears to gradually separate from the upper tape.

However, in the case of (1), it is necessary to make the core thickness at least 1 W by forming a film by vapor deposition or sputtering, but this is practically impossible because film peeling occurs. (2;
In this case, when pasting the non-magnetic metals 5 and 5' onto the cut surface of a core that is only a few microns thick, it is necessary to slightly expose the sliding surface of the core with the tape.

For this reason, precision is required in the work, and it is difficult to stably manufacture products with uniform precision.Therefore, the yield is poor and mass productivity is lacking.

[Purpose of the invention]

This invention was made to solve these conventional problems, and provides a magnetic head that not only can reduce the influence of the contour effect, but also is easy to manufacture, inexpensive, and highly reliable. It is.

[Conventional example]

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

In the figure, the same reference numerals as in FIG. 5 indicate the same or corresponding parts. 7, 7' and 8, 8' are other magnetic alloy films laminated between the magnetic alloy film 2.2' and the substrates 1, 1'. The latter 8, 8' are layers with higher magnetic permeability than the former 7, 7', and the alloy film layers 8, 8' with higher magnetic permeability are the alloy film layers 7, 8' with lower magnetic permeability. It is laminated on the outside of T', that is, on the gap 3 side.

Figure 8 shows the ridges of the magnetic head with such a configuration due to the contour effect, and for comparison, Figure 9 shows the conventional magnetic head (Figure 9).
This is the case in Figure 1). As is clear from both figures, according to the magnetic head of the present invention, it is possible to greatly improve the influence of the contour effect. This is thought to be because two more magnetic circuits are formed near the core portion of the magnetic head, which produces substantially the same effect as when a conventional so-called cut surface is provided in the core portion.

In addition, in the case of this magnetic head, each alloy film T.

Since it can be easily manufactured by simply forming 7' and 8.8' without requiring special processing techniques, it is easy to manufacture and inexpensive. Moreover, unlike conventional products, there is no need for special processing, which improves the reliability of the product.

Although the above embodiment is an example in which two layers of other magnetic alloy films 7.8 are provided, the number of layers may be any number, such as three or four single layers. In this case, it goes without saying that the layers are stacked such that their magnetic permeability increases sequentially from the substrate side to the gap side. The obtained effects are the same as in the above embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, another magnetic alloy film is further laminated between the substrate and the magnetic alloy film in a conventional magnetic head, and the magnetic permeability of each layer is different from the substrate side. Since the layers are stacked so as to increase in size toward the gap side, it is possible not only to reduce output fluctuations caused by the Hunter effect, but also to provide a magnetic head that is easy to manufacture, inexpensive, and highly reliable.

[Brief explanation of the drawing]

Figure 1 is a graph showing the calculated value of the output due to the contour effect of a conventional bulk-wound magnetic head, and Figure 2 schematically shows the relationship between the width of the magnetic head and the magnetic recording medium in the calculation of Figure 1. The figure shown in Figure 3 is a graph comparing the output due to the contour effect between a conventional bulk-wound magnetic head and a magnetic head whose shape has been improved, and Figure 4 (A).
3 is a conventional magnetic head, the same figure (→ is a front view showing a magnetic head with an improved shape in FIG. 3, and 5.
The figure shows a side view of a magnetic head equipped with a conventional magnetic alloy thin film.
6 is a side view of a magnetic head that is an improved version of the magnetic head shown in FIG. 5 using conventional technology, FIG. 7 is a side view of a magnetic head according to the present invention, and FIG.
Graph showing the output due to the effect. FIG. 9 is a graph showing the output due to the contour effect of the conventional magnetic head of FIG. 1... Substrate 2... Magnetic alloy thin film 3... Gap 7, B... Other magnetic alloy thin film Figure 1 Ichimaki Figure 2 - Size 3 Figure 4 (a) (b) Figure 5

Claims (1)

[Claims] (11) A magnetic head comprising a pair of substrates each having a magnetic alloy film provided on the 11-plane, and a metal film bonded between the two substrates through a gap material, wherein the pair of substrates and the magnetic alloy film are (2) The substrate is made of a non-magnetic material. A magnetic head according to claim 1, which is used as a substrate.