JPH0792900B2 - Magnetic head manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a metal core laminated magnetic head effective for use in a magnetic recording / reproducing apparatus such as a VTR and a DAT.

(Prior Art) In recent years, so-called metal tapes having a high coercive force have been put into practical use with the high density recording of VTRs.

Therefore, a magnetic head corresponding to this also uses a metal magnetic material having a high saturation magnetic flux density, for example, a so-called metal core such as amorphous or sendust.

In the bulk state, the metal core has a large eddy current loss at high frequencies, and in order to prevent this loss, the metal core is formed in layers on the auxiliary substrate by a film forming technique such as sputtering or vapor deposition.

FIG. 2 is a diagram showing an example of a conventional metal head and its manufacturing method.

FIG. 2A is a schematic view seen from the front surface of the head, in which the magnetic core forming the head track width W is sandwiched from above and below by the auxiliary substrate, and the magnetic gap g is formed by the pair of core halves joined by the adhesive glass. I am configuring.

A specific manufacturing process will be described with reference to FIGS. 2 (b) and 2 (c).

That is, as shown in FIG. 2B, a metal magnetic material having a thickness corresponding to the head track width W required on one auxiliary substrate 1,
For example, the magnetic layer 2 is formed by layering amorphous by sputtering.

Then, the glass thin film 3 is interposed from above the magnetic layer 2,
Another auxiliary substrate 1'is stacked and the glass thin film 3 is fused to form a metal core laminated body 4 sandwiched by the auxiliary substrates 1 and 1'from the upper and lower surfaces.

FIG. 2 (c) shows such a metal core laminate 4 taken along line AA '.
The core halves 5a and 5b were manufactured by cutting with.

That is, the conventional head uses the core halves 5a and 5b as described above to perform the necessary processing of the winding groove 6 and the processing of the magnetic gap forming surface, and the magnetic head assembly as shown in FIG. 7 was manufactured.

(Problems to be Solved by the Invention) In the conventional manufacturing method described above, formation of the metal magnetic layer (magnetic core) 2 having a thickness corresponding to the head track width W sandwiched between the auxiliary substrates 1 and 1'is assisted. This is a manufacturing method in which a film is formed by sputtering on the auxiliary substrate 1 which is one of the substrates.

However, such a sputtering method has a very slow film forming rate and takes a long time. This means that it takes time to manufacture the magnetic core 2 and the manufacturing cost is high.

Furthermore, the thicker the magnetic film formed on the auxiliary substrate 1 is,
The internal stress of the film thickness causes stress to be applied to the auxiliary substrate 1 from the magnetic layer 2, causing warpage and deteriorating the flatness.

Therefore, a gap 8 is formed between the glass substrate 2 and the other bonding auxiliary substrate 1 ', and in an extreme case, the auxiliary substrate 1'may cause defective adhesion or peel off during processing. was there.

Further, similarly to the above, in the prior art in which the total thickness of the metal magnetic layer 2 is formed on one of the auxiliary substrates 1, there is a difference in the film thickness distribution depending on the location on the substrate 1, and the gap 8 has the same structure as the warp.
There was a problem that caused.

The variations in the stress and the film thickness distribution of the magnetic layer 2 as described above lead to the deterioration of the magnetic characteristics of the magnetic layer 2, and the electromagnetic conversion characteristics of the magnetic head constituted thereby and the poor mechanical dimensional accuracy such as the head track width W. There is a problem that the quality of the magnetic head also deteriorates.

(Means for Solving the Problems) In order to solve the above problems, the present invention divides the required head track width W into each of the upper and lower auxiliary substrates 1, 1 ′ sandwiching the metal magnetic layer 2. A sputtering film is formed.

(Operation) With the above means and configuration, the present invention halves the sputtering time of the metal magnetic layer 2 to shorten the manufacturing time, and further reduces the internal stress of the magnetic film and improves the accuracy of the core flatness by improving the film thickness distribution. Raise and firmly bond the metal core laminate 4,
Prevents adverse effects such as peeling and secures a highly reliable head.

(Embodiment) FIG. 1 is an embodiment showing a magnetic head and a manufacturing process thereof according to the present invention, and shows an example of a video head manufacturing method.

Here, FIG. 1A is a manufacturing process diagram of a magnetic head, and FIGS. 1B to 1E are manufacturing process diagrams of a laminated core.

The pair of core halves 15a and 15b are formed by sputtering the magnetic layers 11 and 11 'on the two auxiliary substrates 10 and 10', respectively, and adhering them together by the crystallized adhesive glass layer 12.

The pair of core halves have a magnetic gap g as a boundary.
Bonding is performed with a glass having a lower melting point than that of the adhesive glass layer 12.

Hereinafter, the manufacturing method of the embodiment of the present invention will be described.

FIG. 1 (b) shows two auxiliary substrates 10,1 made of non-magnetic material.
Magnetic layers 11 and 11 'are sputtered on one surface of 0' so that the total thickness thereof becomes a desired head track width W, and at least one magnetic layer 11 is crystallized as an adhesive glass layer 12. After interposing glass by sputtering, the laminate is heated at a temperature lower than the crystallization temperature of the magnetic layer to bond the magnetic layers 11 and 11 'to each other to form a laminated body 13 having a magnetic layer sandwiched by auxiliary substrates. To do.

Further, the laminated body 13 is cut by a BB 'line with a diamond blade, and the winding groove 14 formed with a grindstone or the like is processed to normally form the core half pair 15a, 15b.

Using such a pair of core halves 15a, 15b, butted at the magnetic gap forming surfaces 19a, 19b, the magnetic gap forming surfaces 19a, 19b and the vicinity or the coupling glass 16 arranged in the winding groove 14,
A magnetic head 17 having a magnetic gap g formed by heating at a temperature equal to or lower than the crystallization temperature of both the magnetic layer and the adhesive glass layer 12 and integrally forming the magnetic gap g is obtained.

Next, a case where the magnetic head 17 uses a Co—Nb—Zr type amorphous alloy will be described.

Auxiliary substrates 10 and 10 'which are made of a non-magnetic material such as crystallized glass or ceramics are processed on the same plane, and the amorphous material is sputtered by 60 to 100Å / min.
Attach at the speed of.

For example, if the track width of the LP mode specification of 8 mm VTR is 15 μm, half the track width is attached on each auxiliary substrate.

Next, on at least one amorphous film, a so-called low melting point crystallized glass that crystallizes at a temperature below the amorphous under-crystallization temperature (500 to 550 ° C) is attached by sputtering to about 1000Å film, and the other amorphous surface. By superimposing 11 'and heating and adhering at about 480 ° C. for about 30 minutes, a 15 μm amorphous laminated body 13 having a 1000 Å glass insulating layer is formed between the auxiliary substrates 10 and 10'.

Such a laminated body 13 is cut to form core halves 15a and 15b, and the required shape and dimension processing are performed on both core halves, and the track alignment of the left and right amorphous cores is performed via a gap material, for example, glass. And forming the head track width W, and heating the bonded glass 16, which is the amorphous glass provided in the winding groove 14 from the gap surface, at 480 ° C., which is lower than the crystallization temperature of the amorphous material, for 30 minutes. The magnetic core 17 is obtained by integrating both core half pairs by.

Further, a case where the magnetic head 17 is configured with a wide head track width of, for example, about 30 μm will be described with reference to FIG.

That is, it is basically the same as the above-mentioned 15 μm specification, and 15 μm of amorphous material, which is half of 30 μm, is deposited on the auxiliary substrates 10 and 10 ′ by sputtering.

However, in order to improve the high frequency characteristics of the amorphous core, it is preferable to use a laminated core having an insulating layer in the above 15 μm.

Therefore, when the amorphous is sputtered to a thickness of 7.5 μm, the SiO ₃ insulating layers 18 and 18 ′ having a thickness of about 1000 Å are interposed by sputtering, and then the remaining amorphous is sputtered to a thickness of 15 μm.

Further, instead of this SiO ₂ , similar to the adhesive glass layer 12,
Low melting point crystallized glass may be sputtered.

In any case, if the head track width W becomes thicker,
As described above, it is possible to form a laminated core in which the necessary interlayer insulating layers are interposed, and sandwich them between the auxiliary substrates and bond them with the crystallized glass on the amorphous body, so that the laminated body can be subjected to the subsequent heat treatment. Can have a consistent adhesion.

As described above, in the manufacturing method of the present invention, the thicker the track width W, the shorter the sputtering time, and the higher the effect of preventing high frequency loss due to stacking and the effect of reducing the stress inside the core. is there.

Therefore, the maximum effect can be exhibited in the future high frequency compatible (MUSE) heads.

Although the method of forming the magnetic core by sputtering has been described in the above description, it can be similarly realized by a thin film forming technique such as a vapor deposition method or an ion plating method.

Further, although the adhesive glass was also interposed by sputtering, a vapor deposition method, a method of mixing glass fine powder in a solvent and coating, or a glass thin plate may be directly interposed to perform heat adhesion.

Further, in the above description, the case where the magnetic core is amorphous has been described, but a metal material having a high saturation magnetic flux density such as sendust can also be applied, and when the case of sendust is considered, it corresponds to its crystallization temperature. Since a treatment temperature of at least 800 ° C is acceptable, adhesive glass and bonded glass are widely selected.

(Effects of the Invention) As described above, in the magnetic head configured by the manufacturing process of the present invention, since the core forming the required head track width W can be formed in half the sputtering time, the manufacturing time can be shortened and the head cost can be reduced. You can

In addition, since the sputtered amorphous materials are bonded with crystallized glass to form a laminated structure, the effect of preventing eddy current loss is exhibited, and the core laminated layer does not change even in the heat treatment in the subsequent step such as gap formation, The track width W and the magnetic gap g with high dimensional accuracy can be obtained, so that the magnetic head 17 with high reliability can be manufactured.

[Brief description of drawings]

FIG. 1 is an embodiment diagram showing a magnetic head according to the present invention and a manufacturing process thereof, and FIG. 2 is a diagram showing an example of a conventional metal head and a manufacturing method thereof. 10, 10 '... Auxiliary substrate, 11, 11' ... Magnetic layer, 12 ... Adhesive glass layer, 13 ... Laminated body, 14 ... Winding groove, 15a, 15b ... Core half, 16 ... Bonded glass, 17 ... magnetic head, 18, 18 '... insulating layer.

Claims (3)

[Claims] 1. A pair of core elements in which a metal magnetic film and SiO ₂ are alternately deposited on an auxiliary substrate by sputtering or vapor deposition, and crystallized glass is interposed at one position between the metal magnetic films of the core element. Core elements are superposed on each other and adhered with crystallized glass by the first heat treatment to form a laminated body, and the laminated body is further cut to form a magnetic gap forming surface at a cut surface between both auxiliary substrates. After forming a head core half and providing a winding groove on at least one of the core halves to smooth the magnetic gap forming surface, both magnetic gap forming surfaces are provided with a glass or oxide metal having a required gap width. Both core halves are united by facing each other with a desired head track width and melt-bonding the non-crystallized glass provided in the winding groove or the appropriate position of the auxiliary substrate by the second heat treatment. Preparation of the magnetic head, characterized in that engaged. 2. The amorphous magnetic alloy is used for the metal magnetic film, and the first and second heat treatment temperatures are lower than the crystallizing temperature of the amorphous alloy. A method for manufacturing the magnetic head described. 3. A sendust alloy is used for the metal magnetic film,
The method of manufacturing a magnetic head according to claim (1), wherein the second heat treatment temperature is higher than the heat treatment temperature.