JPS59231719A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To obtain satisfactory coercive force with the machined surface itself of a base plate forming a magnetic layer by forming the 1st magnetic layer in the form of a thin amorphous alloy film on the base plate then forming successively an insulating layer to serve as a magnetic gap, a conductor layer to serve as a coil and the 2nd magnetic layer thereon. CONSTITUTION:A ferrite block is cut to a desired thickness by an inside or outside circumferential slicer, by which a base plate 2 having <=0.6S surface roughness is obtd. The resulted plate 2 is washed and dried then a Co-base amorphous alloy such as a Co-Nb alloy or the like is deposited by a sputtering method, etc. to form the 1st thin magnetic film 9. A magnetic gap 5 is then formed by Al2O3, etc. and a conductor 6 to serve as a coil, an insulator 7 and the 2nd magnetic layer 8 are successively formed to manufacture a thin film magnetic head. Al2O3 or polyimide or the like is used for the insulator 7 and the 2nd magnetic layer is the same as the 1st magnetic layer 9 or an Fe-Si-Al alloy, etc. may be used for the same. The need for finishing the surface of the plate 1 to a specular surface is thus eliminated and the thin film magnetic head having <=0.5 Oe coercive force is obtd. at a low cost.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a thin film magnetic head, and particularly to a thin film having a structure suitable for obtaining required characteristics even if the magnetic layer forming surface of the substrate remains a machined surface. This relates to magnetic heads.

[Background of the invention]

FIG. 1 is an explanatory diagram of the manufacturing process of a conventional thin film magnetic head. In the conventional thin film magnetic head, a ferrite block 1 shown in FIG. 1(a) is prepared, and as shown in FIG. 1(b), the surface on which the magnetic layer is formed is machined to a predetermined roughness. Next, as shown in FIG. 5(c) ItC, the surface thereof was polished to a mirror finish to obtain a film forming substrate 6, and then, as shown in FIG. 2(d), A first magnetic layer 4 made of a pe-8i-A1 alloy or a Fe-Ni alloy is formed on the mirror-finished substrate 3 by a sputtering method. After forming the first magnetic layer 4, as shown in FIG. ), on the first magnetic layer 4 there is a magnetic gap 5 made of 5iot or AltOn, a conductor 6.5ift forming a coil, an insulator 7 made of AltOn or polyimide resin, and a first magnetic layer. layer 4
and a second magnetic layer 8 forming a magnetic circuit were manufactured by sequentially laminating them in a predetermined thin film pattern.

According to such a method of manufacturing a thin film magnetic head, a multi-track magnetic head having a structure in which a large number of magnetic heads are arranged side by side on the same substrate can be manufactured.

However, the substrate surface on which the first magnetic layer 4 is formed is shown in FIG.
), a magnetic layer with a coercive force of 0.50e or less, which is required for a magnetic layer of a thin-film magnetic head, cannot be formed unless the surface roughness is reduced to 0.03S or less using diamond coating or the like after machining. By the way, in order to give the surface of the board a mirror finish of 0.05S or less, it is necessary to polish it using diamond coating particles, which requires a lot of time and half of the board price is the polishing cost. For this reason, there is a drawback that the thin film magnetic head becomes expensive.

[Purpose of the invention]

The present invention has been made in view of the above, and an object of the present invention is to provide a thin film magnetic head that can have a coercive force required for a thin film magnetic head even if the magnetic layer forming surface of the substrate remains a machined surface. Our goal is to provide the following.

[Summary of the invention]

As shown in FIG. 2, the present invention has the advantage that when a CO-based amorphous alloy is used for the first magnetic layer, if the substrate surface roughness is 0.6S or less, the 0, It became clear that it is possible to have a holding force of 50e or less, and
The surface roughness of 0.68 was achieved by focusing on the fact that it could be achieved only by machining.
The magnetic layer is a thin film made of an amorphous alloy.

[Embodiments of the invention]

The present invention will be explained in detail below using an embodiment shown in FIG.

FIG. 7 is a longitudinal sectional view showing an embodiment of the thin film magnetic head of the present invention shown in FIG. 6; In FIG. 6, 2 is a substrate made of ferrite whose surface on which the magnetic layer is to be formed has a surface roughness of 0.6S or less by only machining, and 9 is a Co
- first magnetic layer made of a thin film of Nb alloy, 5.6.7.
8 is a magnetic gap made up of S gulls sequentially laminated in a certain thin film pattern on the first magnetic layer, as in the conventional case;
Conductor forming the coil, insulator consisting of 5in2, F
This is a second magnetic layer made of an e-Ni alloy thin film.

Next, a method for manufacturing the thin film magnetic head shown in FIG. 3 will be briefly described. First, a ferrite block is created by hot pressing or the like, and this ferrite block is cut into a desired thickness using an inner or outer slicer to form the substrate 2. At this time, the surface roughness was 0.68 or less. Thereafter, the substrate 2 is washed and dried, and a Co-Nb alloy thin film is formed by sputtering at a residual gas pressure of 4 x 10'T.
orr, Ar gas pressure 2x10-3Torr, substrate 2
The first magnetic layer 9 is formed on top of the magnetic layer 9. Thereafter, a magnetic gap 5, a conductor 6, an insulating layer 7, and a second magnetic layer 8 are sequentially laminated on the first magnetic layer 9 by a method similar to the conventional method. The reason why the residual gas pressure and the Ar gas pressure are defined as above is because if the residual gas pressure and Ar gas pressure are exceeded, the holding force required for the thin film magnetic head is 0.
This is because it is not possible to achieve 5Qe or less.

According to the embodiment of the present invention described above, even if the magnetic layer forming surface of the substrate 2 is left as a machined surface, it can have a coercive force of 0.5 Qe or less required for a thin film magnetic head. Therefore, mirror polishing work becomes unnecessary.

What? As the substrate 2, photosensitive glass can be used in addition to ferrite. Moreover, the magnetic gap 5 is made of Al
20. It may be. Further, the insulator 7 is Al2O
, or polyimide resin. Furthermore, the first magnetic layer 9 is made of not only Co-Nb alloy but also Co-
The second magnetic layer 8 may be a Co-based amorphous alloy such as Nb-Zk, and the second magnetic layer 8 may be a Fe-Si-A1 alloy, or the same Co-based amorphous alloy as the first magnetic layer 9. It may be.

Further, the processing of the ferrite block may be any method as long as it can be processed to a surface roughness of 0.6 seconds or less, and is not limited to processing using an inner circumference or outer circumference slicer.

〔Effect of the invention〕

As explained above, according to the present invention, the holding force required for a thin film magnetic head can be obtained even if the magnetic layer forming surface of the substrate is left machined, and the magnetic layer forming surface of the substrate can be polished. This has the effect of eliminating the need to do so.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the manufacturing process of a conventional thin-film magnetic head;
The figure is a diagram showing the experimental results of the relationship between the roughness of the magnetic layer forming surface of the substrate and the coercive force when a Co-based amorphous alloy is used as the first magnetic layer. FIG. 2 is a vertical cross-sectional view showing one embodiment of the invention. 2... Substrate, 5... Magnetic gap, 6
... Conductor, 7... Insulator, 8... Second magnetic layer, 9... First magnetic layer. $l 圀(ct) (b) (C) Figure l (e) 4,, -+ Figure 2 Figure 3

Claims (1)

[Claims] 1. A first magnetic layer, an insulating layer forming a magnetic gap, a conductor forming a coil, and a second magnetic layer forming a magnetic circuit with the first magnetic layer are provided on a substrate, respectively. A thin film magnetic head formed by sequentially laminating layers in a predetermined shape, characterized in that the first magnetic layer is a thin film made of an amorphous alloy. 2. The first magnetic layer on the substrate. The thin film magnetic head according to claim 1, wherein the surface on which the layer is formed has a roughness of 0.68 or less. 6. The thin film magnetic head according to claim 1, wherein the amorphous alloy is a Co-based amorphous alloy. The thin film magnetic head according to item 1 or 2.