JPS6376106A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve the resolution at reading, to prevent the saturation of magnetization at recording and to contrive to improve the conversion efficiency by providing a nonmagnetic layer only to a part between a 1st magnetic layer and a 2nd magnetic layer. CONSTITUTION:A 2nd magnetic core is split into the 1st magnetic layer 11 continuing from the magnetic gap to the core connection and the 2nd magnetic layer 14 continuing from the position retrogressing by a prescribed quantity from the magnetic gap toward the core connection to the core connection. Then a nonmagnetic layer 13 is provided only to a part between the 1st magnetic layer 11 and the 2nd magnetic layer 14. That is, even if the film thickness of the magnetic layer 11 is equal, in comparing the magnetic core having the nonmagnetic layer 13 at the middle and the magnetic core without the nonmagnetic layer 13, the magnetic core without the nonmagnetic layer 13 is hard to be saturated. Thus, by reducing the nonmagnetic layer 13 in the magnetic core as much as possible, the magnetic core hardly being subject to magnetic flux saturation is to be made. Thus, the resolution at reading is improved, the magnetic saturation at recording is prevented and the conversion efficiency of the magnetic head is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head, and more particularly to a thin film magnetic head having a magnetic core consisting of a magnetic layer and a nonmagnetic layer.

[Conventional technology] Thin film magnetic heads are manufactured using electroplating or vacuum deposition methods.

It is manufactured using thin film formation techniques such as sputtering and high-precision patterning technology called photolithography. This typical configuration is described in Japanese Unexamined Patent Publication No. 55-840201. In such a thin-film magnetic head, in order to increase the resolution during reading, reduce magnetization saturation during recording, and increase the conversion efficiency of the magnetic head, it is necessary to JP-A-55-84019 discloses that it is necessary to change the film thickness at the rear part connected to the magnetic core and to make the rear part of each magnetic core thicker than the magnetic gap part to form a two-stage structure. ing.

The method for forming the magnetic core is electroplating.

Vacuum deposition method and sputtering method are generally used. In the sputtering method, a substrate and a magnetic material are placed facing each other in a vacuum chamber, and a glow discharge is generated by applying a high voltage between the substrate and the magnetic material while flowing a gas such as Ar at a rate of about 10 cc per minute. This glow discharge causes a magnetic layer to be deposited over the entire surface of the substrate. The deposition rate at this time is about 200 people per minute, and can be determined by determining conditions such as input power and gas pressure. Further, the thickness of the deposited layer is set to be the thickness necessary for manufacturing the magnetic core.

Thereafter, the substrate is taken out of the vacuum chamber and formed into a predetermined shape by photolithography and high-precision etching techniques such as sputter etching or ion beam etching to form a magnetic core. In the vacuum evaporation method, a substrate and a heater carrying a magnetic material are placed facing each other in a vacuum chamber.
By heating the heater, the magnetic material is evaporated and deposited on the entire surface of the substrate. The thickness of the deposited film is set to the thickness required for the magnetic core, and can be precisely controlled by installing a film thickness monitor using a crystal oscillator near the substrate.

Thereafter, the substrate is taken out from the vacuum chamber, and a thin magnetic layer is deposited over the entire surface of the substrate using sputtering or vacuum evaporation.

The film thickness at this time may be as long as it can function as a current-carrying film during electroplating, and is approximately one-tenth of the film thickness required for the magnetic core. Thereafter, a punched pattern in the shape of a magnetic core is formed on the substrate using a photoresist, and electroplating is performed on the punched pattern to produce a magnetic core.

The electroplating method has the advantage that by forming a photoresist again to cover a portion of the magnetic core during film deposition, it is easy to fabricate the above-mentioned two-tiered magnetic core where the film is partially thick. be. Furthermore, since the shape of the magnetic core depends only on the photoresist pattern in the electroplating method, there is also the advantage that highly accurate patterning can be easily performed. However, as described in JP-A No. 55-82793, in order to form a magnetic thin film with a highly uniform component ratio on an object with undulations, plating conditions must be strictly controlled. There is a hassle that has to be done. In addition, it has been found that manufacturing a thin film magnetic head requires multiple heating processes, and that magnetic thin films formed by electroplating have the disadvantage that their magnetic properties tend to deteriorate during this heating process.

On the other hand, according to the vacuum evaporation method or sputtering method,
It has the advantage that a magnetic thin film with a uniform component ratio can be easily formed on an object with undulations. It is necessary to perform etching by milling, etc., and over-etching deteriorates the film thickness accuracy. Regarding the above-mentioned problems, JP-A-59-104717 discloses that the magnetic core has a two-stage structure. It is described that by providing an inorganic insulating film in the middle, the above-mentioned two-stage magnetic core can be realized with a magnetic thin film formed by vacuum evaporation or sputtering.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not give sufficient consideration to the adverse effect on electromagnetic conversion characteristics caused by providing a non-magnetic layer within the magnetic core, resulting in a problem of deterioration of recording characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide a thin film magnetic head that solves these conventional problems, improves resolution during reading, alleviates magnetization saturation during recording, and improves conversion efficiency of the magnetic head. .

[Means for Solving the Problems] In order to solve the above problems, the present invention includes a first magnetic core, a second magnetic core formed after the first magnetic core is formed, A magnetic gap portion formed at one end of the second magnetic core and the first magnetic core, and a core connection portion for connecting the first magnetic core and the second magnetic core. , and in a thin film magnetic head having a two-stage structure in which the second magnetic core has a thicker film thickness at a rear portion connected to the magnetic gap portion than at a rear portion thereof, the second magnetic core is connected to the core from the magnetic gap portion. The first magnetic layer is divided into a first magnetic layer continuous to the core connection part, and a second magnetic layer continuous to the core connection part from a position set back a predetermined amount from the magnetic gap part in the direction of the core connection part. A feature is that a non-magnetic layer is provided only in a part of the space between the second magnetic layer and the second magnetic layer.

[Effect]

Even if the thickness of the magnetic layer is the same, when comparing a magnetic core with a non-magnetic layer in the middle and a magnetic core without a non-magnetic layer, the magnetic flux is less likely to be saturated in the magnetic core without a non-magnetic layer. Therefore, reducing the number of nonmagnetic layers in the magnetic core as much as possible will produce a magnetic core that is difficult to saturate with magnetic flux.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic longitudinal sectional view of a thin film magnetic head showing an embodiment of the present invention. Here, (a) to (d) show the manufacturing (manufacturing) process of the present thin film magnetic head. The manufacturing process will be explained below with reference to this figure.

First, as shown in FIG. 1(a), an alumina film 2 for insulating the substrate and the magnetic head element is deposited on a substrate 1 by sputtering, and after smoothing the surface by polishing etc. Deposit the film by sputtering. Next, photoresist is applied and exposed through a photomask having the desired shape. After developing this, a pattern is formed by a dry etching method such as ion milling or sputter etching to form the magnetic layer 3.

Next, magnetic layer 4 is formed in the same manner as magnetic layer 3.

At this time, the magnetic layer 3 is completely covered, and the rear part B
forms a first magnetic core that is thicker than the magnetic gap portion A. Next, after depositing the magnetic gap film 5 by sputtering, a polyimide resin that will become the interlayer insulating film 6 is applied.
It is cured and etched into the desired shape. On top of this, electroplating method or.

The conductor coil 7 is formed by depositing a Cu film, which will become the conductor coil, on the entire surface of the substrate by sputtering and then etching it.
First, after forming the second interlayer insulating film 8 and the second layer conductor coil 9 in the same manner, the interlayer insulating film 10 is applied and cured to form the first interlayer insulating film 6, 8, and 10. A predetermined shape is obtained by etching all at once. After this, the magnetic gap film 5
Provide a core connection by etching.

Next, a permalloy IIQ (magnetic layer) 11 is deposited on the entire surface of the substrate by sputtering, and a photoresist pattern 12 is formed thereon so as to have the same planar shape as the magnetic layer 14. It is desirable that the edge portion of this photoresist pattern 12 has a reverse taper or a canopy shape. After a nonmagnetic layer 13 is deposited on the photoresist by sputtering over the entire surface of the substrate, only the portion of the nonmagnetic N 13 on the photoresist is removed from the substrate by immersing the substrate in a solvent that dissolves the photoresist.

After that, as shown in FIG. 1(b), a permalloy film (magnetic FJ) 14 is deposited on the entire surface of the substrate by sputtering, a photoresist pattern 15 is formed, and a pattern is formed by etching by ion milling or the like. A magnetic layer 14 is obtained. At this time, the nonmagnetic layer 13 causes the magnetic layer 11 to
This prevents the permalloy film from decreasing in thickness. magnetic layer 14
After removing the photoresist remaining on the top, a new photoresist pattern 16 is formed as shown in FIG. A magnetic layer 11 is formed by etching. After this, the photoresist is removed and the photoresist is removed.
A thin film magnetic head element as shown in ) is obtained.

[Effects of the Invention] As explained above, according to the present invention, it is possible to form a magnetic core in which the rear portion has a thicker shape than the magnetic gap portion and does not include a nonmagnetic layer in the middle, so that the resolution during reading can be improved. It is possible to manufacture a thin film magnetic head that has increased conversion efficiency, alleviated magnetization saturation during recording, and improved conversion efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of a thin film magnetic head showing an embodiment of the present invention. 4. Magnetic layer, 5: Magnetic gap film, 9; Coil, 10:
Interlayer insulating film, 11: Magnetic layer, 12: Photoresist, 13
: non-magnetic layer, 14: magnetic layer, 15: photoresist, 16
: Photoresist. Figure 1 f^1

Claims (1)

[Claims] 1. A first magnetic core, a second magnetic core formed after the first magnetic core is formed, and a second magnetic core formed at one end of the second magnetic core and the first magnetic core. a magnetic gap portion and a core connection portion for connecting the first magnetic core and the second magnetic core, and the second magnetic core is connected to the rear side of the magnetic gap portion. In a thin film magnetic head having a two-stage structure where the film thickness is thick in some parts, the second magnetic core is connected to a first magnetic layer that is continuous from the magnetic gap part to the core connection part, and a first magnetic layer that is continuous from the magnetic gap part toward the core connection part. A second magnetic layer continuous from a position set back by a predetermined amount to a core connection portion, and a nonmagnetic layer provided only in a part between the first magnetic layer and the second magnetic layer. A thin film magnetic head featuring: