JPH04366406A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To provide a thin-film magnetic head which prevents expansion of a pole length even if a first inflexion point counting from a pole face of a magnetic body layer with an inclination surface is formed nearly at a same position as a throat height zero position in a direction of the throat height and abrasion is made for obtaining a throat height with specified dimensions in a thin-film magnetic head. CONSTITUTION:A length W of an inclination surface of a lower surface of a second magnetic body layer 8 between a first inflexion point A and a second inflexion point C counting from a pole face F of the second magnetic body layer 8 with the inclination surface is reduced to a thickness which is smaller than a thickness t at this inclination surface portion.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head used for magnetic disks and the like.

0002

2. Description of the Related Art Thin film magnetic heads write and read high-density data on magnetic recording media. The structure of this type of thin film magnetic head will be explained with reference to FIG. The thin film magnetic head 1 is formed on a base 2, and has a fan-shaped yoke 9 formed at its tip. York 9
is composed of a composite layer of a first magnetic layer 3 and a second magnetic layer 8, and is provided with a foil-like coil 10 having a substantially elliptical shape as a whole so as to include this yoke 9. One end is connected to the lead portion 13 at the center portion 12, and the other end is connected to the lead portion 14. The yoke 9 consists of a pole part P consisting of a pair of pole pieces, a rear region B, and a rear gap 11 provided in the rear region (Japanese Patent Laid-Open Nos. 55-84019, 1983-84020). Publication No.)
.

The electromagnetic conversion characteristics of the thin film magnetic head 1 are influenced by the throat height TH, which is the gap depth of the pole portion P.
The predetermined dimensions of the pole portion P are obtained by polishing. This dimension is a value of around 1 μm, which provides the best relative output characteristics and resolution characteristics.

0004

By the way, as shown in FIG. 6, a conventional thin film magnetic head is polished in the direction indicated by arrow D to the final polished surface E-E', and the throat height TH of the pole portion P is When the thickness of the pole piece of the second magnetic layer 8 is set to around 1 μm, the pole length, which is the thickness of the pole piece of the second magnetic layer 8, changes from PL1 to PL2.
This is undesirable from the viewpoint of the characteristics of the thin film magnetic head 1. This corresponds to the pole face F of the second magnetic layer 8.
This is because the first inflection point A, counted from , does not coincide with the position Z of zero throat height TH in the throat height direction, and comes out closer to the pole face F side than this. This deviation is due to the thickness t of the slope behind the first inflection point A.
If t is, for example, 2 to 4 μm,
This is because the inflection point A appears by 1 to 2 μm, and as the polishing progresses, the final polished surface E-E' overlaps the inclined surface of the second magnetic layer 8.

The present invention has been made in view of the above-mentioned circumstances.
It is an object of the present invention to provide a thin film magnetic head in which a first inflection point counted from the pole face is located at approximately the same position in the throat height direction as the zero throat height position.

[0006]

Means for Solving the Problems In order to achieve the above object, the thin film magnetic head of the present invention includes at least a first magnetic layer, a gap layer, a second magnetic layer having an inflection point and an inclined surface. In a thin film magnetic head having a coil and an insulating layer between the first and second magnetic layers, the second magnetic layer has a first inflection point and a second inflection point counting from the pole face of the second magnetic layer. The length of the sloped surface of the lower surface of the second magnetic layer between the bending point is shorter than the thickness of the sloped surface portion of the second magnetic layer. Further, the length of the inclined surface of the lower surface of the second magnetic layer between the pole face of the second magnetic layer and the first inflection point counted from the pole face is determined by the second The thickness is made shorter than the thickness of the inclined surface portion of the magnetic layer.

[0007]

[Operation] According to the above-described structure, the first inflection point counted from the pole face, which is formed in the magnetic layer having an inclined surface in the thin-film magnetic head, is located at zero throat height in the throat height direction. It will be at almost the same position as .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a partial sectional view of a yoke of a thin film magnetic head according to the present invention. As shown in the figure, a first magnetic layer 3 made of a magnetic material is disposed on a base 2 made of an insulating material. is formed. A gap layer 4 made of a non-magnetic material is formed on this with a predetermined thickness, and a first insulating layer 5 made of an insulating material is formed between this tip and the pole face F.
It is formed with a space provided between the two. A foil-like coil 10 is attached on the first insulating layer 5, and a second insulating layer 6 made of an insulating material is formed covering this, and a foil-like coil 10 and an insulating material covering it are also formed. A third insulating layer 7 consisting of is formed. A second magnetic layer 8 made of a magnetic material is formed with an inclined surface. This inclined surface has a first inflection point A and a second inflection point C counting from the pole face F. Said first inflection point A
The length W of the sloped surface of the lower surface of the second magnetic layer 8 between and the second inflection point C is the thickness t at this sloped surface portion.
It is shorter than .

In the thin film magnetic head 1 having this configuration,
First, a first magnetic layer 3 is formed by sputtering a magnetic material such as permalloy onto a substrate 2 made of, for example, Al2 O3. A gap layer 4 is formed thereon, for example by sputtering Al2 O3. Next, the first insulating layer 5 is made of, for example, novolac resin, and the first insulating layer 5 is formed on the pole face F.
The foil coil 10 is formed using masking techniques and electrodeposition.

[0011] Then, a second insulating layer 6 made of, for example, novolac resin is formed, and the tip of this second insulating layer 6 is positioned by W' from the tip position of the first insulating layer 5 formed. This is done by shifting backwards by the following dimensions. This dimension W' is the length W of the inclined surface of the lower surface of the second magnetic layer 8.
The length is about the same as the thickness t, and the thickness is less than or equal to the thickness t. For example, if t is 2 to 4 μm, W' is 0<W'≦2 to 4 μm
becomes.

Next, a foil coil 10 is formed using masking techniques and electrodeposition, and a third insulating layer 7 of, for example, novolac resin is formed. Thereafter, a magnetic material such as permalloy is deposited by sputtering so that the thickness t of the second magnetic layer 8 at the inclined surface portion becomes a predetermined thickness (for example, 2 to 4 μm). A body layer 8 is formed.

In the thin film magnetic head 1 configured as described above, the first inflection point A of the second magnetic layer 8 is approximately at the same position Z at the throat height TH of zero in the throat height direction. is formed. This was discovered by the present inventors as a result of repeated experiments and studies under various conditions.

[0014] As a result, the throat height TH of the predetermined dimension
Even if the thin film magnetic head 1 is polished in order to achieve this, the pole length PL remains approximately the same up to the position Z where the throat height TH is zero, and the final polished surface E-E' is the same as that of the second magnetic layer 8. It does not touch the slope between the first inflection point A and the second inflection point B, thereby preventing the pole length PL from increasing.

In another embodiment of the thin film magnetic head of the present invention, as shown in FIG.
The sloped surface of the gap layer 4 makes the length W of the lower surface of the second magnetic layer 8 shorter than the thickness t of the second magnetic layer 8 at the sloped surface portion. It may be something that looks like this. Furthermore, as shown in FIG. 3, another embodiment of the thin-film magnetic head of the present invention includes a second insulating layer 6 and a first insulating layer 6.
without shifting the insulating layer 5 of the first inflection point A and the second inflection point A.
The thickness of the gap layer 4 on the lower surface of the second magnetic layer 8 is changed between the inflection point B and the lower surface of the second magnetic layer 8 is changed to have an inclined surface. W may be made shorter than the thickness t of the second magnetic layer 8 at this inclined surface portion.

Next, the length of the sloped surface of the lower surface of the magnetic layer between the pole face of the magnetic layer having the sloped surface and the first inflection point counted from the pole face is determined by the sloped surface portion. An example in which the thickness is shorter than that will be described with reference to FIG. In FIG. 4, the same parts as those in FIG. 1 will be described with the same reference numerals.

As shown in FIG. 4, a base 2 made of an insulating material
A first magnetic layer 3 made of a magnetic material is formed thereon. A gap layer 4 made of a non-magnetic material is formed thereon to have a predetermined thickness, and a first insulating layer 5 made of an insulating material is formed with its tip in contact with the pole face F. A foil coil 10 is disposed on the first insulating layer 5.
is deposited, a second insulating layer 6 made of an insulating material is formed covering this, and similarly a foil coil 10 and a third insulating layer 7 made of an insulating material covering this are formed. . A second magnetic layer 8 made of a magnetic material is formed with an inclined surface. This inclined surface has a first inflection point A counted from the pole face F. a second magnetic layer 8 between the pole face F and the first inflection point A;
The length W of the sloped surface of the lower surface is shorter than the thickness t at this sloped surface portion.

As is clear from FIG. 4, the thin-film magnetic head 1 having this structure has the first insulating layer 5 formed with its tip in contact with the pole face F, and the rest is the same as that described in the previous embodiment. It was formed in Thereby, the inclined surface of the second magnetic layer 8 is formed starting from the pole face F.

In this case as well, the first inflection point A of the second magnetic layer 8 is at the throat height TH in the throat height direction.
It is formed at approximately the same position as the zero position Z, and as described above, even if the thin film magnetic head 1 is polished, the pole length PL can be prevented from expanding.

[0020]

According to the configuration of the present invention described in detail above, the magnetic layer formed on the magnetic layer having the inclined surface of the thin film magnetic head is
The position of the first inflection point counting from the pole face F is almost the same as the zero throat height position in the throat height direction, and even if the pole part is polished to the specified throat height, , it is possible to prevent the pole length from increasing.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of a main part of an embodiment of a thin film magnetic head according to the present invention.

FIG. 2 is a partial cross-sectional view of a main part of another embodiment of a thin-film magnetic head according to the present invention.

FIG. 3 is a partial cross-sectional view of a main part of another embodiment of a thin film magnetic head according to the present invention.

FIG. 4 is a partial cross-sectional view of a main part of a modified embodiment of the thin-film magnetic head according to the present invention.

FIG. 5 is a perspective view for explaining the configuration of a conventional thin film magnetic head.

6 is a sectional view taken along line XX' of the thin film magnetic head shown in FIG. 5. FIG.

[Explanation of symbols]

1 Thin film magnetic head 2 Base 3 First magnetic layer 4 Gap layer 5 First insulating layer 6 Second insulating layer 7 Third insulating layer 8 Second magnetic layer 9 York 10 Foil coil A First inflection point C Second inflection point F Pole face P Pole part Z throat height zero position

Claims (2)

[Claims] 1. At least a first magnetic layer, a gap layer, a second magnetic layer having an inflection point and an inclined surface, and a coil and an insulating layer between the first and second magnetic layers. In the thin film magnetic head, the length of the inclined surface of the lower surface of the second magnetic layer between the first inflection point and the second inflection point counting from the pole face of the second magnetic layer. However, the second
A thin film magnetic head characterized in that the thickness is shorter than the thickness of the inclined surface portion of the magnetic layer. 2. At least a first magnetic layer, a gap layer, a second magnetic layer having an inflection point and an inclined surface, and a coil and an insulating layer between the first and second magnetic layers. In the thin film magnetic head, the length of the inclined surface of the lower surface of the second magnetic layer between the pole face of the second magnetic layer and the first inflection point counted from the pole face is A thin film magnetic head characterized in that the thickness is shorter than the thickness of the inclined surface portion of the second magnetic layer.