JPS6266406A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To permit the extremely quick formation of metallic oxide layers between welding glass positioned on both sides of a gap by immersing magnetic cores into a metallic alcoholate soln. CONSTITUTION:SiO2 films having 0.125mum thickness corresponding to half the gap width are formed by sputtering to the butt surfaces of a pair of the core blocks 1a, 1a shaped and worked to a prescribed size. The cores are butted and are tentatively adhered by a slight amt. of an instant adhesive agent; thereafter, the core blocks 1a, 1a are immersed into the metallic alcoholate soln. of ZrSiO2 as the essential component for final film formation so that the metallic alcoholate film is stuck thereto to 2-5mum. The blocks are then superheated for 30min at 150 deg.C to form the ZrSiO2 layers having 1-2mum film thickness as corrosion preventive layers 5. The cores having the ZrSiO2 layers are thereafter subjected to glass welding by welding glass and are thereby fixed. The time required for forming the thin metallic oxide layer between the welding glass is thus remarkably shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic head, and more particularly to a method for manufacturing a magnetic head having a structure in which a magnetic core is formed by butting together a pair of core halves. .

[Prior Art] An example of a conventional magnetic head of this type is a video head used in a VTR. This type of imaging head has the appearance shown in Figs. 2 and 3, and has a pair of magnetic cores 1゜1, which play the main role in electromagnetic conversion, butted together via a magnetic gap material 3 such as 5i02, and then welded together. Fix it with glass 2,
Furthermore, it has a structure in which a winding 4 is provided.

On the other hand, with the trend toward longer recording times on VTRs, the track width of video heads, which used to be about 751 Lm, has changed from 50 to 50 Lm.
The track is becoming narrower at 25ILm. Furthermore, with the advent of 8mm VTRs, the relative speed between the head and the medium has decreased, and as a result, the gap width of the video head, which used to be about 0.51Lm, has decreased to about 0.251Lm, which is about the same as that of a standard. It has become narrower.

However, in an image head having such a narrow track and narrow gap width, glass welding at a high temperature of 600 to 800°C has a significant effect due to erosion of the magnetic gap material and magnetic core material, as shown in Fig. 4. As shown in the figure, the end of the gap is eroded into a round shape, making it impossible to obtain the desired gap width.Also, the gap material itself is incorporated into the welded glass, resulting in an initial gap width of 0.25 IL.
Problems such as m being narrowed to about 0.181 Lm have arisen.

As a countermeasure to these problems, metal oxides such as alumina and zirconia, or chromium,
Attempts have been made to form anti-corrosion layers made of metals such as titanium. Here, in the case of metal oxides, it has been experimentally confirmed that the anticorrosion layer is not effective unless it has a thickness of at least lILm or more.

Various methods can be considered for forming the metal oxide layer, but sputtering is common and easy.

[Problems to be solved by the invention] However, in the sputtering method, the sputtering rate is
Because it is extremely slow at approximately 50 angstroms per minute, requiring 400 minutes to form an Igm metal oxide layer, alternatives to sputtering are needed.

On the other hand, in the case of metal layers, it has been experimentally confirmed that after glass welding, bubbles that are thought to be generated due to the reaction of glass with metal remain on the glass, and that peeling occurs between the metal and glass. Therefore, there are problems such as not being practical.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a magnetic core formed by a pair of core halves butted against each other, and a medium sliding surface for fixing the pair of core halves. A method was adopted in which a metal oxide layer was formed between the fused glasses located on both sides of the gap by immersing the magnetic core in a metal alcoholate solution.

[Function] By employing the structure as described above, a metal oxide layer can be formed in an extremely simple manufacturing process in an extremely short time without requiring complicated operations required for sputtering or the like.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

In this embodiment, the track width is 25#1. m, gap width 0.
This is an example in which the present invention is applied to an image head having a weight of 25 gm.

First, as shown in Fig. 1, an S+02 film with a thickness of 0.125 gm, which corresponds to the gap width, is formed by sputtering on the abutting surfaces of a pair of core blocks la and la that have been shaped into predetermined dimensions. After butting them together and temporarily fixing them with a small amount of instant adhesive, attach the core tabs tff, la, l.
2 to 5#1.a was immersed in a metal alcoholate solution containing Zr5i02 as the main component of the final product. Zr5i02 with a film thickness of l~2 JLm by depositing a metal alcoholate coating of m and then heating at 150 °C for 30 min.
A layer was formed to form the anticorrosive layer 5. After this Zr5
The core having the i02 layer was fixed by glass welding using a welding glass.

In the manufacturing process in this example, the metal alcoholate solution was adjusted to have a film thickness of 1 to 2 Jim, but this film thickness is the lower limit of the film thickness at which the desired anticorrosion effect can be obtained, and the maximum It has a sufficient anticorrosion effect up to 60p, m.

However, when the film thickness exceeds 60 gm, fine racks tend to occur in the film, and the initial effect decreases. The film thickness is controlled by Zr5, the final product in the metal alcoholate solution.
This is possible by adjusting the density of i02.

As a result of conducting another oxide film using a metal alcoholate solution in which the main component of the final product was 5i02, the anticorrosion effect was obtained within the range of film thickness from 2 gm to 507 hm.

As described above, a metal oxide layer can be formed between the cores and between the cores and the welded glass in a short time using a simple manufacturing process without adversely affecting the cores or the welded glass.

[Effects] As is clear from the above description, according to the present invention, a metal alcoholate solution is used as a means for forming a thin metal oxide layer between the magnetic core and the welded glass located on both sides of the cap on the medium sliding surface. By implementing the simple manufacturing process of immersing the device in the liquid, the time required for the manufacturing process can be significantly shortened without impairing the intended function.

[Brief explanation of the drawing]

FIG. 1 is a plan view illustrating one embodiment of the present invention, showing a state in which an anticorrosive layer is formed on the contact surface between the magnetic core and the welded glass. Figure-
Figure 3 is an enlarged plan view of the vicinity of the gap seen from the tape sliding surface direction, and Figure 4 shows the state in which the magnetic core material and magnetic gap material are eroded by glass welding. FIG. l...Magnetic core 2...Welded glass 3...
Magnetic gap material 4...Winding 5...Corrosion protection layer

Claims (1)

[Claims] The magnetic core is immersed in a metal alcoholate solution between a magnetic core formed by a pair of core halves butted against each other, and welded glass located on both sides of the gap on the medium sliding surface for fixing the pair of core halves. A method of manufacturing a magnetic head, comprising forming a metal oxide layer.