JPS59151334A - Magnetic head - Google Patents

Abstract

PURPOSE:To attain high density for a magnetic disk device by providing separately write and read heads, making the center of the core width of both the heads coincident with each other and narrowering the head core width for the read head less than the core width for the write head. CONSTITUTION:The heads 11 and 13 are formed to a sliding contact body 1 directly or by the indirect way that the heads are formed separately and then bonded to the body 1. The write head 11 is formed at first by forming a ferromagnetic thin film with vapor deposition or electrodeposition of iron-nickel alloy or the like by the known thin film head method and then applying a gap 111 and a prescribed winding to the tip by etching. Further, the read head 13 is formed to the write head 11 via a spacer 12, and the center line O is made common to each core and the core width of the read head 13 is formed narrower than the core width of the write head 11. Since no winding is required for the read head 13 by forming the head 13 by a magneto-resistance element MR and the rate of electromagnetic conversion is increased more than that of an inductive head, the manufacture is easy and the performance is improved.

Description

[Detailed description of the invention] (]) Technical field of the invention The present invention relates to a magnetic head suitable for high density.

(2) Prior Art and Problems Recently, with the increase in the density of magnetic disk drives, improvements in the performance of magnetic heads have been required.

In a conventional magnetic head, as shown in FIG. 1, the same spatula)*h is used for writing and reading.

However, as density increases, the flying height of the magnetic head must be lowered, and as a result, the fringing magnetic flux F generated from both ends of the head h during writing is reduced. Therefore, the width W of the writing area on the medium, which was previously different, is
The difference between C and core width C is approaching zero.

In such a situation, if the same head is used for writing and reading, when the head follows the recorded track and reads information, thermal expansion of the medium, head, and other components may occur. There is a problem in that a slight displacement of the head due to expansion/contraction force causes off-track, and various characteristics fluctuate.

(3) Object of the Invention The object of the present invention is to separately provide a write spatula P and a read spatula, align the centers of the core widths of both heads, and make the read head r core as wide as the write spatula core. By narrowing the width, the purpose is to make the magnetic disk drive compatible with higher density.

(4) Structure of the Invention According to the present invention, in a magnetic head in which the sliding body, the writing head, and the reading head are formed with a large number of layers and the flying height on the air outflow end side between the medium and the medium is low, the air outflow A writing head and a reading head are separately provided on the end side, and the centers of the core widths of both heads coincide, and the core width of the reading spatula P is narrower than the core width of the writing head. A magnetic head is provided which is characterized in that the gap length of the read head P is shorter than the gap length of the write head.

(5) Examples of the Invention The present invention will be explained below using examples with reference to raw material drawings.

FIG. 2 is a schematic side view of the magnetic head according to the present invention. The head of the present invention is a sliding body 1 which is equipped with a rock head (P) 1 and a reading head 13 (both heads) + 11, 13.
is arranged on the upper air outflow end side of the medium 2. A wave sensor 12 made of an insulating material or an electromagnetic shielding material is inserted between the two heads 11 and 13.

Both heads at the air outlet end], 1. , 13 was provided in part because optimal design conditions are required for writing and reading, and it is better to make the gap length of the read head smaller than that of the write head for better efficiency and resolution. This is advantageous in this respect, and also because the amount of fringing magnetic flux generated at both ends of the core is small when the write head 17 records a large amount of information on the medium 2. The air outlet end is a portion where the flying height of the head is low.

In the device according to the invention, both heads 11, 13 are formed on the sliding body 1 either directly or indirectly by forming the heads separately and then gluing them.

First, the writing head 11 is made by forming a ferromagnetic thin film by vapor depositing or electrodepositing an iron-nickel alloy or the like using a known thin film head method, and then by etching a gap 1 at the tip.
11 is further formed by applying a predetermined winding.

Next, an outflow head 13 is formed on this writing head 11 via a spacer 12. At this time, each core has a common center line O, and the writing head 13 has a core width of 2" 13 for the outflow. The width of the read head 13 is narrower than the core width of the read head 11. Depending on the material, the read head 13 may be a magnetoresistive element (FIG. 3), a monolithic (FIG. 4), or a thin film (FIG. 5).

As is well known, in the magnetoresistive element MR (Fig. 3 (2)), the magnetization M changes in proportion to H'' (n=1=2) in an external magnetic field H, and this causes staining. Resistance value R=-7
This is an element that applies the 25f change.

$ As the magnetoresistive element MR, Fe −Nl r Fe r
There is a Co alloy.

By forming the read head 13 with a magnetoresistive element MR, winding is not required, and the electromagnetic conversion rate is much higher than that of an inductive head, making manufacturing easier and improving performance.

In Figure 4 (1), a monolithic type with windings 112 and 113 is used as the writing spatula (11) as in the past, or a new monolithic reading spatula is added on the back side.
+13 was formed. In order to form a read head on the back surface, it is sufficient to bond them together using a known thin film head fabrication technique as shown in FIG. 4(2). Furthermore, as shown in Fig. 4 (3), an insulator is buried to make the back surface wider and flat so that the required track width does not change.
3 can also be formed.

In FIG. 5, a writing spatula 111 is formed as a thin film, and a reading head 13 is formed on the thin film with a spacer 13 interposed therebetween.
Figure 5 (])) and those placed on both sides (Figure 5 (2))
There is.

(6) Effects of the Invention According to the above-mentioned embodiment of the present invention, as is clear from FIG. 6, the writing and reading pads 11 and 13 are separated and the center line 0 of each core width is made to coincide with each other. At the same time, the core width of the read head 13 was made smaller than the core width of the write head 011.
Even if the writing rad core width is the same as the recording area, it is possible to provide a magnetic head that has a wide off-track margin and is suitable for high density.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional magnetic head, FIG. 2 is a schematic side view of a magnetic spatula r according to the present invention, and FIGS. 3 to 5 are illustrations of first, second, and third embodiments of the present invention. FIG. 6 is a diagram illustrating the effects of the present invention. DESCRIPTION OF SYMBOLS 1...Sliding body, 2...Medium, 11...Writing head, 12...Spacer, 13...Reading head, a
... Air inflow end, b... Air outflow end. (7) 1st Figure 2 Figure 3 (1) (2) Q40 Figure 5 Figure 62 1.1

Claims (1)

[Claims] 1. In a magnetic head having a low flying height on the air outflow end side between the sliding body, the write head, and the read head and the medium, a writing head is provided on the air outflow end side. A head and a read head are provided separately, and the centers of the core widths of both heads are aligned, and the core width of the read head is narrower than the core width of the write head. A magnetic head characterized in that the gap length is shorter than the gap length of a writing head. 2. A magnetic head according to claim 1, wherein the read head is formed of a magnetoresistive element. 3. A magnetic head according to claim 1, wherein the sliding body is made of ferromagnetic ferrite and the writing head is monolithically formed. 4. A magnetic head according to claim 1, wherein the write head is formed of a thin film.