JPS62144305A - Composite magnetic material - Google Patents

Abstract

PURPOSE:To improve reproducing characteristics and mass-productivity by connecting a metallic magnetic material, such as Sendust or the like, and oxide magnetic material, such as ferrite or the like to each other, by filling the grooves in connecting surfaces with a glass. CONSTITUTION:Mirror-polished surfaces 8 and 9 of ferrite 1 and Sendust 2, respectively, which are filled with glass 7 are made abut against each other, the glasses 7 on both surfaces are fused with each other by re-melting and the ferrite 1 and the Sendust 2 are connected to each other to form a block half 10. The other mirror-polished surfaces of the two block halves 10 are connected while track width regulating grooves 12 thereof being made coincide with each other and as part of the track width regulating grooves 15-17 to obtain a head block 18. Therefore, a composite magnetic material with little deterioration in magnetic characteristics due to gap loss can be obtained, mass- productivity is excellent because a number of processes are substituted by one process and a cost can be reduced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention combines a metal magnetic material with a high saturation magnetic flux density such as sendust and an oxide magnetic material with high magnetic permeability such as ferrite to form a metal-based magnetic material. This invention relates to a composite magnetic material that can be used with high coercive force tapes.

[Conventional technology]

In recent years, with the increase in the density of magnetic recording, metal-based recording media with high coercive force have been developed. When trying to record on a medium, the following problems arise.

In other words, the coercive force of a metal-based high coercive force recording medium is 1
Generally speaking, in order to perform sufficient recording on a recording medium, a magnetic flux density of about 10 times is required.

On the other hand, the saturation magnetic flux density of ferrite is at most 5
000 Gauss, it is not suitable for recording on such a high coercive force recording medium.

If a metal magnetic material such as sendust having a high saturation magnetic flux density is used as a head material in order to solve such problems with ferrite materials, there is a drawback that reproduction sensitivity is reduced due to eddy current loss in the high frequency region.

In order to eliminate these drawbacks, a heno-P using a composite type magnetic material as shown in FIG. 11 has come to be used.

In FIG. 11, 21 is ferrite, 22 is sendust, and the ferrite 21 sandwiches the sendust 22 to form a magnetic cap 23, and the two halves are bonded using glass 24 as a bonding material.

A groove 25 for winding the winding wire is formed in one half.

In a head using such a composite magnetic material, the ferrite 21 compensates for the magnetic properties of sendust in a high frequency region, thereby improving reproduction sensitivity.

[Problem that the invention seeks to solve]

Heads made of such composite magnetic materials require a process in which a thin plate of ultra-thin metal magnetic material, approximately 20 microns thick, is sandwiched between ferrite plates, which are then processed to match the shape of the magnetic head. Therefore, there was a drawback that mass production was significantly hindered.

[Purpose of the invention]

The present invention is intended to eliminate the above-mentioned drawbacks of conventional composite magnetic material heads, and by improving the means for combining metal magnetic materials and oxide magnetic materials, the saturation magnetic flux density of metal magnetic materials can be increased. The purpose of the present invention is to provide a composite magnetic material that takes advantage of the high magnetic permeability of oxide magnetic materials to reduce eddy current loss in high frequency ranges, improve playback characteristics, and improve mass productivity.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention forms a groove on at least one surface of the joint surface of a metal magnetic material and an oxide magnetic material, fills the groove with glass to bond them, and uses the groove as a head material. The purpose of this study is to obtain a composite magnetic material of

[Embodiments of the invention]

An embodiment of the composite magnetic material of the present invention and a method of manufacturing a head using the same will be described below with reference to FIGS. 1 to 10.

In FIG. 1, 1 is a magnetic core material of ferrite, 2 is a magnetic core material of sendust, and a groove 6 for glass filling is bored in the joint surface of these.

In this /Ji 6, the working temperature is 640° as shown in Figure 2.
Place the glass rod C, heat it to 700° C., and fill the groove 6 with this glass 7.

Next, the surfaces 8 and 9 of the ferrite 1 and the sendust 2 filled with the glass 7 are polished to a mirror surface so that these surfaces 8 and 9 are in complete contact with each other during bonding.

Then, the surfaces 8 and 9 filled with the mirror-polished glass 7 of the ferrite 1 and sendust 2 are butted against each other, and heated to 710°C to remelt the glass 7. Ferrite 1 and Sendust 2
are combined as shown in FIG. 3 to form a semi-dead block 10.

A set of two such semi-vacuum blocks 10 is provided with a track width regulating groove 12, a slope 13 for connecting the two semi-vacuum blocks, and one of the semi-vacuum blocks 10 is provided with a winding groove 11 as shown in FIG. Form as shown in FIG.

Then, the surfaces on which the track width regulation a12 is formed are mirror-polished so that they can be brought into close contact with each other, and the portion of the trunk width regulation groove 12 (the sixth
In order to use the hatched area (shaded area in the figure) as a gap forming part, a gap spacer 14 made of alumina (Al2O2), silicon oxide (S i 02 ), etc. is deposited on each half-block 10 to a thickness that is half the required gap length. 6th method
．． Form as shown.

The above-mentioned mirror-polished surface of such a semi-dead block 10 is bonded so that the track center regular grooves 12 are aligned, and a bonding glass 15, The head block 18 shown in FIG. 8 is obtained by filling the head blocks 16 and 17 and joining the two half-closed blocks 10.

The bonding glasses 15, 16, and 17 at this time are those whose working temperature is lower than that of the glass 7, and for example, those whose temperature is 400°C are used.

Therefore, at this working temperature, the glass 7 will not melt and the ferrite 1 and sendust 2 will not separate.

Next, the portion of the head block 18 that will become the tape sliding surface is cylindrically polished as shown in FIG.

Then, this head block 18 is sliced to have the same thickness as the head, and the head block 18 is sliced to have the same thickness as the head.
9 is obtained, and a winding wire 20 is applied to this as shown in FIG. 10 to complete the head.

In the above embodiment, the grooves 6 were formed in both the ferrite 1 and the sendust 2 and filled with the glass 7, but the grooves 6 may be formed in either the ferrite 1 or the sendust 2, or the number and shape of the grooves may be changed. It is not limited either.

Also, glass 7 is melted into the grooves 6 of ferrite 1 and sendust 2, and by remelting the glass 7, ferrite 1 and sendust 2 are melted.
However, after the ferrite 1 and the sendust 2 are butted together, a glass rod may be inserted into the groove 6 and the glass rod may be melted and bonded.

〔Effect of the invention〕

As described above, the present invention combines a metal magnetic material with high magnetic saturation such as sendust and an oxide magnetic material with high magnetic permeability such as ferrite, and fills a groove formed in at least one of the bonding surfaces thereof with glass. The material is then joined.

Therefore, since the metal magnetic material and the oxide magnetic material are bonded except for the bonding groove and without an adhesive layer, deterioration of magnetic properties due to gap loss is extremely small.

The significant difference in thermal expansion due to temperatures of 600°C or higher when joining a metal magnetic material and an oxide magnetic material is absorbed while the joining material, glass, hardens from a molten state.
There will be no large residual strain.

In addition, since the joining grooves are formed in the longitudinal direction of the half block, the joining surface can be widened in the longitudinal direction, so the bonding force is strong and has sufficient strength for various subsequent processing. The metal magnetic material and the oxide magnetic material do not separate during processing.

In addition, by increasing the working temperature of the glass used to bond the metal magnetic material and the oxide magnetic material and lowering the working temperature of the glass used to bond the semi-dead blocks, the glass used for bonding in the previous process is If the working temperature of the glass in the previous process is set to 600℃ or higher without causing any adverse effects, the range of glass selection used in the subsequent process will be expanded, and the post process after bonding will be more flexible. Reliability can also be improved.

Furthermore, it is also possible to form a half block using a composite magnetic material, combine these half blocks to make a head block, and slice this to make a magnetic head. Therefore, half blocks and head blocks require a large number of processes. It has the advantage that it only needs to be dug once, is easy to dig, can be mass-produced, and can reduce costs.

[Brief explanation of drawings]

1 to 10 show the steps of the head manufacturing method according to the present invention, in which FIG. 1 is a perspective view showing a groove for filling with glass, FIG. 2 is a side view of the state filled with glass, and FIG. Figure 3 is a side view of the semi-dead block after coupling, Figure 4 is a perspective view of the winding groove processed, Figure 5 is a front and side view of the track width regulating groove and the coupling slope, and Figure 6 is the gap spacer. Fig. 7 is a perspective view of the head block with half-dead blocks attached, Fig. 8 is a perspective view of the cylindrical surface polished, Fig. 9 is a perspective view of the head block after slicing. FIG. 10 shows a perspective view of the same head block with wires wound thereon, and FIG. 11 is a perspective view of a conventional head block made of a composite type magnetic material. 1... Ferrite, 2... Sendust, 6. ...
groove, 7...glass, 10...half-closed block, 11.
...Winding groove, 12...Track medium regular groove, 13...
Slope, 14... Gap spacer, 15, 16, 17
...Glass, 18...Hetflock, 19...
head.

Claims (1)

[Scope of Claims] [Registered Trademark] A groove is formed in at least one of the joining surfaces of a metal magnetic material with a high saturation magnetic flux density such as sendust and an oxide magnetic material with a high magnetic permeability such as ferrite, A composite magnetic material characterized by being bonded by filling it with glass that adheres the bonding surface.