JPH03237605A - Production of composite type magnetic head - Google Patents

Abstract

PURPOSE:To prevent the peeling of thin films by removing a part of the thin films, then mechanically grooving the removed parts, thereby forming the grooves arriving at members to constitute magnetic head half bodies. CONSTITUTION:The thin films 3, 3 of 'SENDUST(R)' (Fe-Al-Si alloy) to be used as a high saturation magnetic density material are provided in the butt parts of a pair of the magnetic head half bodies 2, 2 consisting of a ferrite material opened with the grooves 5 for regulating a track width. Further, a nonmagnetic material layer 4 consisting of SiO2 is provided between the two thin films to form the magnetic gap part parallel with the butt parts. Glass is packed in the grooves 5 for regulating the track width. The thin film 3 consisting of the 'SENDUST(R)' and the nonmagnetic material layer 4 are formed by etching. The formation of the grooves 5 is executed by mechanically grooving the removed parts formed after the thin films 3 are partly removed by etching. The peeling of the thin films is prevented in this way and the improvement in the yield of production is made. In addition, the track width W is exactly regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a composite magnetic head used in a magnetic recording/reproducing device.

A composite magnetic head shown in FIG. 6 has been proposed as a magnetic head for use in magnetic recording and reproducing devices such as VTRs (
Utility Model Application Publication No. 56-174119). This is because the abutting surfaces of a pair of magnetic head halves (2) (2) made of a high resistivity magnetic material such as a ferrite material are coated with a magnetic material having a higher saturation magnetic flux density than the magnetic material, such as sendust.
Thin films such as permalloy and amorphous magnetic materials (3) (3)
This increases the saturation magnetic flux density near the magnetic gap.

In conventional composite magnetic heads, even if the saturation magnetic flux density is increased by using a thin film such as sendust, the width T where the thin film (3) joins the bonding surface of the magnetic head half is the same as the target track width. Moreover, since the magnetic head half is formed of a ferrite material, there is a risk that magnetic saturation will occur at the bonding surface.

Furthermore, in conventional composite magnetic heads,! ! ! Due to the method of transportation, there were structural problems as described below. That is,
To manufacture a composite magnetic head, as shown in Figure 2,
Track width regulating grooves (2I) are formed in each of the pair of magnetic head block halves (11) and (12), and a thin film (3) of, for example, sendust is formed by vacuum evaporation or sputtering on the abutting portions of both block halves. The film is formed to a thickness of several μm using a known film forming technique.

Further on the upper surface of the thin film (3) is a non-magnetic layer (4) of Sin.
) is formed to a thickness of approximately 0.1 μm using the same film-forming technique, and then the two block halves are butted together as shown in Figure 3, and the track width regulating groove (5) is filled with molten glass. Unify your body.

Then, by slicing this to an appropriate thickness as shown in FIG. 4, a magnetic head (1) having the above-described non-magnetic layer (4> as a magnetic gap portion) can be obtained.

However, in the film forming process of the above manufacturing method, sendust is vacuum-deposited or sputtered through a mask having slit-shaped openings at the abutting portions of the two block halves, so that the adhesion of sendust particles may occur. The condition may be different between the area near the edge of the opening of the mask and the center of the opening, or the sendust particles may also enter the back side of the mask, preventing a film of uniform thickness from being formed, causing the product to deteriorate as shown in Figure 6. The Sendust thin film (3) of the new composite magnetic head has rounded shoulders (
31) (31) occurs. In such magnetic heads, the track width W cannot be accurately defined, which causes variations in recording and reproducing performance between products.

Also, in order to solve the above problem, both professionals 1. Before forming track width regulating grooves in the half body, a film of Sendust and Sin is formed on the entire joint surface, and then these films and ferrite ware are simultaneously coated with a diamond blade or C.
It is also possible to adopt a method of forming the track width regulating groove (5) and the non-magnetic layer (4) by machining with a BN blade, but with this method, the thin film of sendust may peel off during processing. there were. Of course, if the peeling area is large, it cannot be used as a product, but even if the peeling is slight, there may be a chipped part (32) as shown in Figure 6, and the above-mentioned flat shoulder Similar to section (31), the substantial track width W of the magnetic head is uncertain.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a composite magnetic head in which peeling of a thin film is prevented when grooves such as track width regulating grooves are formed on a member forming a magnetic head half.

[11] In the manufacturing method of the present invention, the groove (5) reaching the member that becomes the magnetic head half (2) is formed by removing a part of the thin film (3) by etching, and then applying a machine to the removed part. It is characterized in that it is performed by performing target groove machining.

[For production]

According to the above manufacturing method, no or less thin film (3) is removed by mechanical grooving, and peeling of the thin film (3) is prevented.

[Special effects]

According to the method of manufacturing a composite magnetic head according to the present invention, peeling of the thin film is prevented, manufacturing yield is improved, and the track width W can be accurately defined.

The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 is an enlarged plan view of the vicinity of the magnetic gap of the composite magnetic head according to the present invention, showing a pair of magnetic head halves (2) made of ferrite material with track width regulating grooves (5). )(2) is covered with a thin film (3)(
3), and a non-magnetic layer of Sin (
4) to form a magnetic gap parallel to the abutting portion. Further, the track width regulating groove (5) is filled with glass. The above Sendust thin film (3)
The nonmagnetic layer (4) is formed by etching as described later.

2 to 5 show the steps for manufacturing a composite magnetic head according to the present invention.

Figure 2 shows a block in which sendust thin films (3) (3) are provided at the abutting portions of a pair of 7-elite wafers (20) (20) in which U-shaped grooves (21) are formed to serve as track width regulating grooves. Half # (11) (12)! It shows a situation where the person is under a precept. In addition, one 7 elite wafer (2o)
A coil groove (13) that will later become a coil winding hole (8) is provided in the coil groove (13).

FIG. 5 shows the procedure for forming a thin film (3) of sendust on a ferrite wafer (2o) by etching, which is a known technique. First, as shown in FIG. The thin film (3) is formed to a thickness of about 1 to 10 μm using a film forming method such as a sputtering cylinder.
A band-shaped corrosion-resistant layer (6) having a width W defined by the track width W is repeatedly formed on the top surface at a constant pitch. The strip-shaped corrosion-resistant layer (6) is formed by coating the surface of a thin film of Sendust with a dichromate-based photosensitive liquid to a thickness of approximately 1 μm, and after drying, a photomask having a slit-like opening with a width W is placed on top of the coating. , is formed through an exposure process of irradiating ultraviolet rays and a development process of removing the portions not covered by the original plate using a developer.

Next, as shown in Figure 5(b), a thin film of sendust (3)
The portions not covered by the corrosion-resistant layer (6) are dissolved with an etching solution. In this example, a 30% nitric acid solution was used at 25° C. as an etching solution. At this time, corrosion progresses not only in the depth direction but also in the lateral direction, that is, below the corrosion-resistant layer (6), resulting in so-called side etching. It has been confirmed that the reproducibility is good. Therefore, by predicting the amount of side etching in advance, the corrosion-resistant layer (
6) It is possible to determine the width W. For example, if the thickness of the Sendust thin film (3) is 10 .mu.m and etching is performed for 6 minutes and 30 seconds using the above etching solution, the amount of side etching will be about 8 .mu.m. In the case of this example,
It is necessary to set the track width W to 24±2 μm, and for this purpose, the width W0 of the corrosion-resistant layer (6) may be set to 40 μm.

In this embodiment, this side etching is utilized to give the sendust thin film (3) a desired cross-sectional shape.

That is, the side etching progresses faster in the part of the sendust film closer to the corrosion-resistant layer (6), and as a result, as shown in the figure, the width T of the bonding surface of the thin film (3) with the ferrite wafer (20) after forming is equal to that of the upper surface. It becomes larger than the width W.

Also, the side surface (30) of the thin film (3) is approximately 90 degrees from the top surface.
Be moderate.

After the etching is completed, as shown in FIG. 5(C), a U-shaped groove (21) which will become a track width regulating groove is formed in the ferrite wafer (20) using a diamond blade. In this case, it is necessary to bring the blade as close as possible to the sendust thin film (3) without touching it, but compared to forming a sendust thin film or ferrite wafer using only machining, rough machining is required. . Sendust thin film (
3) The upper surface is further coated with S+0 using the same film formation technique as described above.
A thin film marked * is formed to serve as a non-magnetic layer (4) for defining the gap length. The non-magnetic layer (4) is shown in Figure 5 (a).
) is formed on the entire upper surface of the sendust thin film (3), and in the step shown in FIG. 5(b), this non-magnetic layer is first subjected to wet etching or dry etching using oxidized acid or the like. , the nonmagnetic material layer may be formed into a predetermined shape.

Two block halves (11) (1) formed as above
2) are brought into contact with a non-magnetic material layer (4) as shown in Fig. 3, the track width regulating groove (5) is filled with molten glass, and both block halves are bonded and integrated. Body layer (4
), a track width regulating groove (5), and a coil winding hole (8).
) is completed. If you slice this into appropriate thickness,
A plurality of composite magnetic heads (1) shown in FIG. 4 are obtained.

As shown in FIG. 1, the sendust thin film (3) of the magnetic head (1) manufactured in this way has an upper surface with a high degree of flatness whose width closely matches the track width W, and a substantially perpendicular upper surface from the upper surface. It has a side surface (30) extending in the direction and a joining surface between the magnetic head half having a width larger than the upper surface, and there are no rounded shoulders due to an uneven bottom film or holes due to machining.

Incidentally, in the above-mentioned example, the thin film of sendust is entirely coated with tCyfI by etching, but it is also possible to form only the upper layer of the thin film by etching and simultaneously form the remaining lower layer along with the U-shaped groove by machining. It has been experimentally confirmed that if the thickness of the lower layer is approximately 1 μm, peeling due to machining will hardly occur.

Further, in this embodiment, the sendust thin film is formed by chemical etching, but it goes without saying that other well-known etching methods may be used, such as ion beam etching.

Furthermore, the same effect as in this embodiment can be obtained by using permalloy or an amorphous magnetic material other than sendust as the material of the thin film having a high saturation magnetic flux density.

In manufacturing the magnetic head according to the present invention, a thin film with a high saturation magnetic flux density can be simultaneously formed on the entire surface of the butt part of the ferrite wafer, and the U-shaped groove can be processed with relatively rough precision. Higher productivity can be obtained compared to conventional manufacturing methods.

[Brief explanation of drawings]

FIG. 1 is an enlarged partial plan view of a composite magnetic head according to the present invention, FIG. 2 is a perspective view of a pair of block halves, FIG. 3 is a perspective view of a magnetic head block, and FIG. 4 is a completed magnetic head. FIGS. 5(a), 5(b), and 5(c) are explanatory diagrams showing a method of forming a thin film by etching, and FIG. 6 is an enlarged partial plan view of a conventional composite magnetic head. (2)...Magnetic head half, (3)...Sendust thin film, (4)...Nonmagnetic layer, (5)...Track width regulating groove, (20)... Ferrite wafer (member that becomes half of the magnetic head), (21)...U-shaped groove, W
...Track width.

Claims (2)

[Claims] (1) After forming a thin film of a magnetic material having a higher saturation magnetic flux density than the magnetic material on at least one of a pair of magnetic head halves made of a high resistivity magnetic material, A groove of a predetermined width reaching the member is formed in the thin film, and then the thin film remaining on the member that will become the one half of the magnetic head and the member that will become the other half of the magnetic head are connected through a magnetic gap. A method for manufacturing a composite magnetic head in which the grooves are bonded by using a method, wherein the grooves are formed by removing a part of the thin film by etching, and then mechanically forming grooves on the removed portion. A method of manufacturing a magnetic head. (2) The method for manufacturing a composite magnetic head according to claim (1), wherein the etching is performed by ion beam etching.