JPS6257115A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To obtain a head having good quality without having a pseudo gap by applying electric power of a prescribed value between a pair of electrode plates one of which a ferrite material is imposed and executing reverse sputtering in an Ar atmosphere under prescribed conditions. CONSTITUTION:The 1st plate 6 for an anode and the 2nd plate 7 for a cathode are provided in a vacuum vessel 5 and the ferrite 1 is imposed on the 2nd plate 7. About 19mTorr Ar atmosphere is maintained in the vessel 5 and reverse sputtering is executed by applying 0.01-0.12W/cm<2> electric power to the inside of the vessel 5 from an external AC power source 8. Then adhesive power is intensified by the effect of forming adequate lattice defects acting as the center for nuclear formation in the initial stage of film formation and the effect of removing the impurities sticking to the substrate surface. The magnetic head, as shown in the figure, consisting of the ferrite materials 1a, 1b provided with the thin films 3a, 3b consisting of a magnetic metallic material with a gap spacer 2 in-between is thus manufactured.

Description

[Detailed description of the invention]

(A) Industrial Application Field The present invention relates to a method of manufacturing a magnetic head used in a VTR or the like. (b) Conventional technology The magnetic tape holder currently used in home VTRs
γFe2O8 is mainly used, but 8
A small VTR called MilliVideo has a high coercive force.
= 1400 to 1500 oersted) metal tape is used. The reason for this is that in order to miniaturize recording and reproducing devices, it is necessary to increase the recording density, so a recording medium that can shorten the recording wavelength of a signal has been required. On the other hand, in conventional magnetic heads made only of ferrite for recording on metal tapes, the saturation magnetic flux density of ferrite is about 5,500 Gauss at most, so a magnetic saturation phenomenon occurs, making it impossible to fully demonstrate the performance of metal tapes. Therefore, the area near the operating gap where magnetic saturation phenomenon is most likely to occur is made of a metal magnetic material with higher saturation magnetization than ferrite.

[For example, permalloy, sendust, amorphous magnetic material]
A magnetic head (referred to as a composite magnetic head) constructed with
) (lb) is a ferrite core half-open, (2) is a gap spacer made of 5i02 film, (3a) and (3b) are thin films made of the metal magnetic material, (4) is glass, and (6) is a winding hole. . In the case of magnetic heads, sputtering is often used to form the metal thin film on ferrite. Then, after the ferrite on which the metal thin film has been formed is subjected to groove processing, bonding processing, swing processing, etc., it is made into a head, but during these steps (especially during groove processing), the metal Vvi film is Although it may peel off, the ease with which it peels differs greatly depending on the cleanliness of the ferrite surface before film formation. Therefore, in the past, the ferrite surface was cleaned with argon ions immediately before film formation, or a cleaning process was performed by so-called reverse sputtering. This treatment significantly increases adhesion. (c) Problems to be Solved by the Invention However, in the composite magnetic head processed in this manner, the influence of a pseudo gap appears at the boundary between the ferrite and the metal thin film. Therefore, it is important to suppress the occurrence of pseudo gaps as much as possible without weakening the adhesion between the ferrite and the senduct. In the present invention, reverse sputtering is performed in an atmosphere of about 19 mTorr by applying power between a pair of electrodes with a ferrite material placed on one of them and reducing the power to 0, OI W/c.
This is carried out under the conditions selected as follows: m'' or more and 0.12 W/cm or less. Also, if the power is too small, the discharge becomes unstable and cannot be sustained, but 0.0
If it is 1 W/0 m2 or more, it is possible to obtain stable discharge and therefore stable connectivity for reverse sputtering. (f) Example Figure 1 is a schematic diagram of an apparatus for performing reverse sputtering, in which a first plate (6) for an anode and a second plate (7) for a cathode are arranged in a vacuum container (5). 2nd play) +71
Ferrite (1) is placed on top, and lacquerware (5) is approximately 19m long.
Place in a Torr argon atmosphere. In the praying state, power is applied to the inside of the container (5) from an external AC power source (8). In general, when reverse sputtering is applied to the ferrite surface before film formation, it has the effect of creating moderate lattice defects on the substrate surface that act as nucleation centers in the initial stage of film formation, and nucleation by displacing electrons on the surface of the substrate material. The adhesion force is enhanced by the effect of creating an extra space for adhesion to the substrate surface and the effect of removing impurities by adsorption to the substrate surface. At the same time, it was found that the crystallinity of the ferrite surface is significantly disturbed and becomes amorphous when the reverse sputtering power is too high. The amorphization of ferrite is
This means that that part is made non-magnetic, so when a thin metal film is later deposited, a pseudo gap will be created between the ferrite and the thin metal film. Therefore, the argon pressure of the sputtering device was maintained at 19 mTorr, the power was changed, and the crystal state of the ferrite surface was measured by electron beam diffraction. The photograph in FIG. 2 is an electron micrograph showing the results. The figure (A) shows the ferrite surface at O, l 2 W/cm
This shows the electron beam diffraction when reverse sputtering is performed with a power of . (B) is a similar diagram when reverse sputtering is not performed. (C) shows the case of reverse sputtering with a power of 0.06 W/cm2, and (D) shows the case of reverse sputtering with a power of 0.19 W/cm.
Comparing the above, in both cases there is no disturbance in the crystallinity of the ferrite surface. (In Q, there is no disturbance in the crystallinity of ferrite compared to (B). However, compared to (D) Ifi and (B), the brightness is unclear and the distance between vertical lines is widened, so the crystallinity is disturbed. It can be seen that such disordered crystallinity indicates that an amorphous state has occurred. Therefore, if ferrite is used, a magnetic head with a pseudo gap is formed. However, as shown in Figure 1 and (C), 0.12
If the power is W/cm2 or less, the crystallinity of the ferrite surface is not destroyed, so the formation of a pseudo gap can be suppressed. On the other hand, in high-frequency discharge in the container f151, when the pressure is high, the discharge can be sustained by capturing electrons by the high-frequency waves, but when the pressure becomes low, the electrons are no longer captured and are absorbed by the electrodes, increasing the loss of electrons and causing downsend. Since the second coefficient γ of ion trapping speed has already been reduced, a high electric field is required to achieve sufficient ionization. In the experiment, the power was 0.5 mTorr in an argon atmosphere. OIW/
It was confirmed that the discharge could continue stably if it was at least cm2. -(g) Effects of the invention According to the invention, since the discharge is stable, suitable reverse sputtering is possible, and dust, dirt, grime, etc. on the ferrite surface are wiped cleanly, so that the metal to be applied later The adhesion of the thin film is enhanced. Furthermore, since the crystallinity of the ferrite surface is prevented from being disturbed and turned into an amorphous state, a high-quality magnetic head without pseudo gaps can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a sputtering apparatus for explaining the manufacturing method of the present invention, and FIG. 2 is a micrograph for explaining the present invention. FIG. 3 is a perspective view of a magnetic head to which the present invention is directed. (1)... Ferrite, (la) (lb)... Ferrite core half L (21... Cap spacer, (3
a) (3b)...metal thin film, (6)...first grate, (7)...second plate, f8+...external AC power supply.

Claims (1)

[Claims] (1) When manufacturing a magnetic head made of ferrite material to which a thin film made of a metal magnetic material is attached between gap spacers, reverse sputtering is performed using argon before applying the thin film to the ferrite material. In a method for manufacturing a magnetic head, electric power is applied between a pair of electrode plates on which a ferrite material is placed on one side in an argon atmosphere of approximately 19 mTorr, and the electric power is reduced to 0.0 mTorr.
A method for manufacturing a magnetic head, characterized in that reverse sputtering is performed at a rate of 1 W/cm^2 or more and 0.12 W/cm^2 or less.