JPS62114113A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve head characteristics and to form a magnetic gap and main magnetic pole on a surface having small surface roughness by constituting a magnetic material intersecting with a coil of upper and lower magnetic materials and a rear magnetic material connecting said materials and forming the respective magnetic materials on a flat surface. CONSTITUTION:The lower magnetic material 2 and insulating film 3 are formed on a glass substrate 1 and after the rear magnetic material 6 and insulating film 5 are formed in the hole of the film 3, the top surfaces thereof are flattened to expose the surface of the magnetic material 6; further, the upper magnetic material 7 and protective film 8 are formed thereon. The respective magnetic films are provided with anisotropy in such a manner that the axes of easy magnetization face the transverse direction of tracks, by which the high magnetic permeability is obtd. even at a high frequency and the films having good magnetic characteristics are obtd. The head having the good characteristics is, therefore, obtd. without generating the part where the thickness of the magnetic material on a slope is extremely small even if the space between the upper and lower magnetic materials is increased. The magnetic gap and main magnetic pole are formed on the surface having the small surface roughness without being affected by the lower layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thin film magnetic head used for recording and reproducing magnetic recording media.

Conventional technology Conventionally, for example, in order to record and reproduce data on a perpendicular recording medium,
A magnetic head having a structure as shown in FIG. 3 was used. The structure will be explained according to FIG. A lower magnetic material 2 made of permalloy, amorphous magnetic material, etc. is formed on a non-magnetic substrate 1, and a lower magnetic material 2 made of Cu, AM, etc. is formed on the non-magnetic substrate 1 via an insulating film 3 made of SiO, Au, 03, etc. A coil 4 is formed. Furthermore, an upper magnetic body 7 which becomes the main magnetic pole is formed so as to be in contact with the lower magnetic body 2 at the center portion 9 of the coil 5 via an insulating film 5, and a protective film 8 of Sin, AM, O, etc. is formed thereon. It is formed.

Problems to be Solved by the Invention Generally, in order to efficiently guide the magnetic flux generated by the current flowing through the coil to the tip of the head, the magnetic resistance between the upper and lower magnetic bodies should be large. It is necessary to increase the spacing between the magnetic bodies. The distance between the upper and lower magnetic bodies at the tip of the head is determined by the characteristics of perpendicular recording or in-plane recording, but in any case, the larger the distance between the upper and lower magnetic bodies in the coil portion, the better the efficiency. In order to connect the upper and lower magnetic bodies 2 and 7 at the center of the coil, a hole is made in the insulating film 5 of the coil, and the upper magnetic body 7 is formed from above.
The magnetic film formed on the flat area is thinner and has a lower density than the magnetic film formed on the flat area.

Since it is difficult to obtain magnetic properties, it is necessary to make the upper magnetic body 7 extremely thick. In the case of a ring-shaped head with a narrow magnetic gap at the tip, the distance between the upper and lower magnetic bodies must be narrowed to the magnetic gap length even near the magnetic gap, so there are two magnetic bodies on the slope, which affects the electromagnetic conversion characteristics of the head. The impact on This problem becomes more serious as the distance between the upper and lower magnetic bodies is increased in order to increase the efficiency of the head.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a thin film magnetic head consisting of a coil and a magnetic material interlinked with the coil, in which the magnetic material is at least connected to the lower magnetic material, the upper magnetic material and the coil. It consists of a rear magnetic body connecting the lower magnetic body and the upper magnetic body at the center, and each magnetic body is formed on a flat surface.

By placing the rear magnetic body that connects both magnetic bodies at the center of the coil between the upper and lower magnetic bodies, and forming each magnetic body on a flat surface, the magnetic path of the head is thinner than the others on the slope. Since the magnetic material with poor magnetic properties is eliminated, the magnetic resistance of the magnetic core is reduced and the sensitivity of the head is increased.

EXAMPLE An example of the present invention will be described below based on the drawings. 1st
The figure shows a first embodiment of the invention. A lower magnetic body 2 made of a Co--Nb--Zr amorphous magnetic material is formed to a thickness of 5 μm on a substrate 1 of crystallized glass. 8 on top of that
A 1 μm thick AM coil 4 is formed by photoetching through an insulating film 3 such as 10□, and a rear magnetic body 6 is formed in a hole made in the center of the coil in the insulating film 3.

The rear magnetic body 6 is an amorphous magnetic body with a thickness of 6 μm formed by a lift-off method. Alternatively, if a permalloy plating film is used, a relatively thick film can be formed in a short time. After forming an insulating film 5 of Sio on this, the upper surfaces of the insulating film 5 and the rear magnetic body 6 are almost flattened by an etch-back method in which resist is applied and ion etching is performed to flatten the upper surface. 6 is exposed on the surface. An upper magnetic body 7 made of an amorphous magnetic material is formed on this, and a part of the tip is etched to a thickness of 0.3 μm to form a main magnetic pole. In addition, AQ203 with a thickness of 10 μm
A protective film 8 is formed to form a head. Each magnetic material is anisotropic so that its axis of easy magnetization faces in the track width direction, and high magnetic permeability can be obtained even at high frequencies. Since all of these magnetic materials are formed on a flat surface, a film with good magnetic properties can be easily obtained. Here, the flat surface may have unevenness to the extent that it does not impair the magnetic properties of the magnetic material formed thereon, and also includes a surface with gentle unevenness due to an etch-back method.

Moreover, if the lower magnetic body 2 is a ferromagnetic material such as MnZn ferrite, it can be used as a substrate. Also, N i
If a ferromagnetic material with a high resistivity such as Zn ferrite is used, the coil can be formed directly on the substrate without the insulating film 3. Alternatively, the upper and lower magnetic bodies may be reversed and the lower magnetic body may be used as the main magnetic pole.

FIG. 3 shows a second embodiment of the invention. After the coil 4 is formed in the same manner as in the first embodiment, the rear magnetic body 11a and the front magnetic body 11b are formed by the lift-off method. An insulating film 5 is formed thereon and planarized by polishing. Further, an upper magnetic body 13 and an insulating film 8 are formed via an Sio film 12 with a thickness of 0.3 μm, which serves as a magnetic gap, to constitute a head. By polishing the surface that forms the upper magnetic material, it is possible to remove the unevenness on the surface of the film formed in multiple layers and easily form a surface with a roughness of 10 nm or less, so even a ring head with a narrow magnetic gap can be used with high accuracy. Can be formed. In addition, in the case of a magnetic head for perpendicular recording as shown in Figure 1, even if the thickness of the main pole is 0.2 μm or less, the roughness of the film forming surface is small, so the magnetic film formed on it is A head with good characteristics and high sensitivity can be obtained.

Effects of the Invention According to the present invention, by placing the rear magnetic body between the lower magnetic body and the upper magnetic body, even when the distance between the upper and lower magnetic bodies is increased, it is possible to avoid problems on the inclined surface as seen in conventional heads. A head with good characteristics can be obtained without creating a portion where the thickness of the magnetic material is extremely thin. Furthermore, by polishing the surface on which the upper magnetic material is formed, the magnetic gap and the main magnetic pole can be formed on a surface with small surface roughness without being affected by the underlying layer.

[Brief explanation of drawings]

1 and 2 are sectional views showing a thin film magnetic head according to an embodiment of the present invention, and FIG. 3 is a sectional view showing a conventional thin film magnetic head. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Lower magnetic body, 3, 5... Insulating film, 4... Coil, 6. lla... rear magnetic body, l
lb...Front magnetic body, 7.13...Top magnetic body, 8
...Protective film, 12...SiO film agent Yoshihiro Morimoto Figure 1 Figure 2

Claims (1)

[Claims] 1. In a thin film magnetic head consisting of a coil and a magnetic body linked thereto, the magnetic body connects at least a lower magnetic body and an upper magnetic body, and connects the lower magnetic body and the upper magnetic body at the center of the coil. A thin film magnetic head consisting of a rear magnetic body, each magnetic body being formed on a flat surface. 2. The thin film magnetic head according to claim 1, wherein the surface on which the upper magnetic body is formed is flattened by polishing.