JPS595966B2 - Magnetic head formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a thin film magnetic head, and in particular, to a method for forming a thin film magnetic head, in particular, heat treating an organic silicon compound to form a SiO2 film;
This relates to using it as an insulating film.

A thin film magnetic head is a magnetic head formed using thin film technology to increase the magnetic recording density of magnetic drums, magnetic tapes, magnetic disks, etc. Its structure is as shown in Figure 1 when the coil conductor has one turn. It's getting old.

That is, the lower magnetic body 2 has one end on the lower magnetic body that is in contact with one end of the lower magnetic body, and the other end that is in contact with the other end of the lower magnetic body and a magnetic gap G.
an upper magnetic body 6 that faces the upper magnetic body 6 and thereby forms a magnetic circuit with a magnetic gap in part together with the lower magnetic body;
and a conductor 4 whose part passes between both magnetic bodies and crosses the magnetic circuit.
and an insulating film 3 that electrically insulates between the conductor and both magnetic materials.
and 5, which are laminated on the substrate 1 using thin film technology. A magnetic head having such a structure is manufactured in the following steps. (1) A different plate 1 is prepared, a magnetic film such as permalloy is formed on one surface of the plate by vapor deposition, sputtering, plating, etc., and this is formed into a lower magnetic body 2 of a predetermined shape using photolithography technology. (2
) An insulating film 3 made of SiO2, At203, Si3N4, etc. is formed on the lower magnetic body 2 and the substrate 1 by vapor deposition, sputtering, or the like. (3) At, Cu,
A conductor film of Au or the like is formed and molded into a desired shape to obtain the conductor 4. (4) sio2, At on a predetermined location of the conductor film 4
An insulating film 5 made of 2o3, si3N4, etc. is formed. (
5) Remove the insulating film 3 from the portions of the lower magnetic body 2 that should come into contact with the upper magnetic body 6. (6) Upper magnetic body 6 and lower magnetic body 2
Formed in the same manner as. When measuring the magnetic properties of the magnetic head thus manufactured, it was found that the read voltage value varied by about 6 times from 50 μV to 300 μV. So, when we investigated the cause of this, we found that
As shown in FIG. 2, which shows the cross section of AA'f) in FIG. I found out that there are some. In a thin film forming method using a vacuum, the film is deposited from above the pattern, so that the film thickness at the stepped portion may become small or no film may be formed. Therefore, short circuits between the conductor and the magnetic material are mainly caused by the manufacturing method of the insulating film. In this way, it was found that the read voltage was low when the conductor and the magnetic material were short-circuited. In order to prevent this short circuit, the thickness of each insulating film 3 was increased from the conventional 1 μm to 3 μm, which made it possible to prevent short circuits and form a head with uniform characteristics.
On the other hand, since the magnetic gap length becomes too wide, the read voltage becomes about 501 tV.

It turned out that it was not possible to make the insulating film thicker. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a magnetic head that eliminates the drawbacks of the prior art described above, that is, prevents short circuits between conductors and magnetic materials without increasing the thickness of the insulating film.

A feature of the magnetic head forming method of the present invention that achieves this purpose is that the insulating film between at least the lower magnetic material and the conductor is formed of an SiO2 film obtained by applying an organic silicon compound and then heat-treating it. At the point.

A 20% ethyl alcohol solution of tetraalkoxysilane was used as the organosilicon compound.

In order to determine the heat treatment conditions for this, it was decided to obtain three differential heat values and a heating loss curve prior to the experiment. 100℃
Figure 3 shows the results of measurements taken at a heating rate of 10°C/min on samples dried for 10 minutes.

From this figure, it was found that heat generation occurred from 310°C, the first thermal decomposition reaction of the tetraalkoxysilane occurred, and re-decomposition occurred at about 400°C. Based on this result, the heat treatment temperature was set to 450°C. An ethyl alcohol solution of tetraalkoxysilane 2001) was spin-coated on a sample with a lower magnetic pattern formed on the substrate using a photoresist spinner, and then heat-treated at 450°C for 1 hour. It is shown in Figure 4.

The insulating film thus obtained is also formed on the slopes of the stepped portions due to the viscosity of the solution, and does not suffer from the drawbacks of conventional insulating films formed using vacuum. In some cases, as shown in FIG. 5, the side surface of the lower magnetic body 2 may be etched in the shape of a canopy, but in this case, according to the present invention, the canopy is etched due to the viscosity of the solution. The inside can be filled with a SiO2 film. By using this method to prevent a short circuit between the lower magnetic body 2 and the conductor 4, the read voltage, which had previously varied from 50 to 300 μV, was now able to be suppressed to a range of 280±20 μV.

Also, the magnetic gap length is 0.
It was found that since the increase was only about 1 to 0.15 μm, no deterioration in magnetic properties was observed.
As organic silicon compounds, the effects of coating films were investigated using eight types of alcohol solutions shown in Table 1 other than tetraalkoxysilane.

As a result, although the optimum values of heat treatment conditions vary depending on the substance and content, in any case, it was possible to suppress variations in the characteristics of the magnetic head, and this effect was confirmed. According to the present invention, it is possible to prevent short circuits between the magnetic material and the conductor, which has until now been the biggest cause of variations in the characteristics of magnetic heads, so the variations in properties can be reduced to 1/3 to 1/5 of the conventional level. There is an effect.

The following describes the case where the insulating film between the lower magnetic material and the conductor is formed using an organic silicon compound solution, but the same can be applied to the insulating film between the conductor and the upper magnetic material. can.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a thin film magnetic head to which the present invention is applied, Figure 2 is a sectional view of AN in Figure 1, and Figure 3 is the result of examining heat treatment conditions when using a tetraalkoxysilane solution. , FIG. 4, and FIG. 5 are model diagrams showing that SiO2 is deposited on the stepped portion. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Lower magnetic body, 3... Insulator,
4...Conductor, 5...Insulator, 6...Upper magnetic body.

Claims (1)

[Claims] 1. A lower magnetic body, one end of which is in contact with one end of the lower magnetic body, and the other end of which is opposed to the other end of the lower magnetic body through a magnetic gap, whereby a part of the lower magnetic body is magnetically attached to the lower magnetic body. It includes an upper magnetic body that forms a magnetic circuit with a gap, a conductor with a predetermined number of turns that partially passes between the two magnetic bodies and crosses the magnetic circuit, and an insulating film that insulates the conductor and both magnetic bodies. , in which these are layered on a substrate using thin film technology, the insulating film interposed between the lower magnetic material and the conductor is heated after applying a solution of an organic silicon compound on the lower magnetic material and the substrate. SiO_2 produced by
A method for forming a magnetic head characterized in that it is formed of a film.