JPH06338014A - Magnetic head - Google Patents

Abstract

PURPOSE:To avoide sinking of a joined part of adhesive glass and to improve CSS characteristics by specifying the whole film thickness of the adhesive glass and oxidizing thin film to 0.4-1.7mum, more preferably 0.5-1.5mum. CONSTITUTION:Head core blocks 13, 14, after bonded is cut shown as a chain line in the figure according to the outer dimension of a magnetic head, machined into a specified shape, and subjected to polishing, etc., to produce a magnetic head. In this process, by specifying the whole film thickness of the adhesive glass and the oxidizing thin film to 0.4-1.7mum, preferably to 0.5-1.5mum, sinking in the joined part of the glass is prevented. Moreover, CSS characteristics can be improved and the defect rate due to peeling in the bonded part can be suppressed to about 5%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a magnetic recording / reproducing apparatus, and more particularly to a magnetic head in which a metal magnetic thin film is sandwiched between nonmagnetic substrates to form a magnetic core.

[0002]

2. Description of the Related Art In recent years, with high density recording of magnetic storage devices, high saturation magnetic flux density, narrower track, etc. have been required for magnetic heads.

To satisfy these requirements, Fe-
There is a laminated magnetic head in which a metal magnetic film such as an Al—Si alloy or an amorphous alloy is formed on a substrate by a thin film forming technique such as vapor deposition or sputtering to form a magnetic core. However, it has been found that the structure in which the non-magnetic substrate is arranged on only one surface of the metal magnetic film has problems of low mechanical strength and poor wear resistance. Therefore, the applicant
In order to solve these problems, a magnetic head having a structure in which both sides of a metal magnetic film are sandwiched by non-magnetic substrates was developed and a patent application was filed (Japanese Patent Application Laid-Open No. 63-249913, Japanese Patent Application No. 3-308800). issue).

A conventional magnetic head will be described below. FIG. 7 is a perspective view of a main part of a conventional magnetic head.
FIG. 8 is a partially enlarged view of part A of FIG. 7. 1 is a slider of a magnetic head, 2 is a metal magnetic film, 3 is calcium titanate,
The first non-magnetic substrate 4 made of α-hematite, crystalline glass or the like, and the second non-magnetic substrate 4 made of the same material as the first non-magnetic substrate 3.
Non-magnetic substrate 5 of S is formed on the surface of the metal magnetic film 2.
First oxide thin film made of iO ₂ etc., 6 is metal magnetic film 2
And an adhesive glass for joining the second non-magnetic substrate 4 to each other, 7 a second oxide thin film provided between the adhesive glass 6 and the second non-magnetic substrate 4, 8 a magnetic gap, and 9 a winding groove Is.

The thickness of the adhesive glass 6 is about 3 μm for a magnetic head for VTR or the like.

A method of manufacturing the conventional magnetic head having the above structure will be described below. First, the metal magnetic film 2 is formed on the surface of the first non-magnetic substrate 3 such as crystallized glass or ceramics by a method such as sputtering, and the first oxide thin film 5 such as SiO _{2 is} formed on the metal magnetic film 2. Form. Next, a second oxide thin film 7 such as SiO ₂ and an adhesive glass 6 are formed on the other side of the second non-magnetic substrate 4 on which the metal magnetic film 2 is not formed. The magnetic core block is manufactured by stacking several substrates manufactured in this way and applying pressure and heat while welding. Then, the winding groove 9 is formed in at least one of the pair of laminated magnetic core blocks, and SiO 2 having a predetermined thickness is formed.
_A magnetic head is manufactured by laminating a laminated magnetic core through _two films or the like to form a butt magnetic gap 8 and machining it into a predetermined shape.

[0007]

However, in the above-mentioned conventional structure, the adhesive glass 6 for adhering the first non-magnetic substrate 3 and the second non-magnetic substrate 4 on which the metal magnetic film 2 is adhered is adhered.
It is known that when the thickness of the portion becomes thick, the portion of the adhesive glass 6 is likely to have a dent due to the polishing of the side surface, and it is extremely difficult to reduce the step to 10 nm or less. Contact start / stop (hereinafter,
The abbreviated form (CSS) easily deposits from the disk medium, resulting in an increase in the frictional force with the disk medium and a lack of durability. On the contrary, if the adhesive glass layer is made thin, sufficient adhesive strength cannot be obtained and the production yield of the magnetic head is reduced.
On the other hand, oxide thin films 5 and 7 provided between the metal magnetic film 2 and the adhesive glass 6 and between the adhesive glass 6 and the second non-magnetic substrate 4.
When the film thickness of the non-magnetic substrate 3 is reduced, the adhesive glass 6 reacts and corrodes the metal magnetic film 2 to cause characteristic deterioration.
4 and the adhesive glass 6 react with each other to cause foaming of the adhesive glass 6 and chipping of the non-magnetic substrates 3 and 4, resulting in a decrease in yield and lack of productivity.

The present invention solves the above-mentioned problems of the prior art, and does not generate a step in the adhesive glass portion, and the CSS
An object of the present invention is to provide a magnetic head which can improve characteristics, has sufficient adhesive strength, is low in cost, and is excellent in mass productivity.

[0009]

In order to achieve this object, the magnetic head of the present invention has the following structure.

According to a first aspect of the present invention, there is provided a magnetic head, wherein a metal magnetic film is deposited on the surface of a non-magnetic substrate, and the first surface is formed on the surface of the metal magnetic film.
A magnetic head formed by fusing an adhesive glass to weld a first non-magnetic substrate having an oxide thin film formed thereon to a second non-magnetic substrate having a second oxide thin film formed on the surface of another non-magnetic substrate. Therefore, the total film thickness of the adhesive glass and the first oxide thin film and the second oxide thin film fused by the adhesive glass is 0.4 μm to 1.7 μm, preferably 0. 5 μm
.About.1.5 .mu.m.

According to a second aspect of the present invention, in the magnetic head according to the first aspect, the thickness of the adhesive glass is 0.1 μm to 1.0 μm, preferably 0.2 μm to 0.8 μm.

[0012]

With this configuration, the total thickness of the adhesive glass and the oxide thin film is formed to be 1.7 μm or less, so that the dent in the adhesive glass portion at the time of polishing the side surface can be suppressed to 10 nm or less. The characteristics can be improved. On the other hand, the total thickness of the adhesive glass and the oxide thin film is 0.4.
Since it is formed with a thickness of μm or more, it is possible to prevent the deterioration of the characteristics due to the reaction between the metal magnetic film and the adhesive glass, the decrease in the adhesive strength, and the foaming of the adhesive glass due to the reaction between the non-magnetic substrate and the adhesive glass even in the welding heat treatment step. Therefore, it is possible to prevent a decrease in adhesive strength, and it is possible to obtain a magnetic head having sufficient mechanical strength.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic head according to an embodiment of the present invention will be described below with reference to the drawings. 1 is a perspective view of a main part of a magnetic head according to an embodiment of the present invention.
[Fig. 2] is a partially enlarged view of a portion A in Fig. 1. 1 and 2, 1 is a slider of a magnetic head, 2 is a metal magnetic film, 3
Is a first non-magnetic substrate, 4 is a second non-magnetic substrate, 8 is a magnetic gap, and 9 is a winding groove. These are the same as those in the conventional example and are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 10 is a first oxide thin film such as a SiO ₂ film formed on the surface of the metal magnetic film 2, 11 is a film thickness for bonding the metal magnetic film 2 and the second non-magnetic substrate 4 from 0.2 μm to 0. 8 μm adhesive glass, 12
Is a second oxide thin film formed on the surface of the second non-magnetic substrate 4.

The total thickness of the oxide thin film 10 formed on the surface of the metal magnetic film 2, the oxide thin film 12 formed on the surface of the second non-magnetic substrate 4 and the adhesive glass 11 is 0.5.
It is formed so as to be not less than 1.5 μm and not less than μm.

A method of manufacturing the magnetic head having the above structure will be described below. FIG. 3A is a cross-sectional view showing a step of forming a first non-magnetic substrate of a magnetic head in one embodiment of the present invention, and FIG. 3B is a second magnetic head in the embodiment of the present invention. FIG. 3C is a cross-sectional view showing the non-magnetic substrate forming step, and FIG. 3C is a perspective view showing a state in which the non-magnetic substrates of the magnetic head according to the embodiment of the present invention are joined. First, as shown in FIG. 3A, the surface of the first non-magnetic substrate 3 made of calcium titanate, α-hematite, crystallized glass or the like is coated with a Fe—Al—Si alloy or the like by a DC or RF sputtering device. Then, the metal magnetic film 2 having a required thickness, for example, 7 μm is formed. A film having a thickness of 0.3 μm to 0.5 μm is formed on the metal magnetic film 2 for the purpose of preventing adsorption of contaminants and oxidation, prevention of reaction between the adhesive glass 6 and the metal magnetic film 2, and improvement of abrasion resistance. The first oxide thin film 10 made of a SiO ₂ film or the like is formed by RF sputtering. Then, a glass having a low melting point, for example, an adhesive glass 11 for welding at a working temperature of 500 ° C. to 600 ° C. and having a film thickness of 0.2 μm to 0.8 μm is formed on the first oxide thin film 10.
Is formed by a sputtering method.

On the other hand, as shown in FIG. 3B, the second non-magnetic substrate 4 and the adhesive glass 1 are formed on the surface of the second non-magnetic substrate 4.
For the purpose of preventing the reaction of No. 1 and improving wear resistance, 0.3 μm is formed by the RF sputtering method like the first oxide thin film 10.
A second oxide thin film 12 having a thickness of 0.5 μm is formed. Here, the total film thickness of the oxide thin films 10 and 12 and the adhesive glass 11 is controlled to be 0.5 μm or more and 1.5 μm or less.
Although the adhesive glass layer is formed on the uppermost surface of the first non-magnetic substrate 3 in this embodiment, it is formed on the second oxide thin film 12 on the second non-magnetic substrate 4 side. Alternatively, the first non-magnetic substrate 3 and the second non-magnetic substrate 4 may be used.
A low-melting-point glass thin film having a thickness half that required may be formed on the uppermost surface of each of the above. Next, the first non-magnetic substrate 3 and the second non-magnetic substrate 4 are pressure-welded and heated and welded using a jig, and then, as shown in FIG.
A nonmagnetic substrate block as shown in (c) is formed.

Next, the head core block forming process will be described with reference to FIG. FIG. 4A is a perspective view of a main part of a laminated block in which a plurality of non-magnetic substrates of a magnetic head according to an embodiment of the present invention are laminated, and FIG. 4B is a perspective view of a magnetic head according to an embodiment of the present invention. FIG. 4C is a perspective view of a main part of a plate of a magnetic substrate, and FIG. 4C is a perspective view of a main part of a head core block of a magnetic head according to an embodiment of the present invention. First, the first non-magnetic substrate 3 is also formed on the upper surface of the second non-magnetic substrate 4.
Similarly, a plurality of nonmagnetic substrates on which a metal magnetic film or the like is formed are laminated and bonded to form a nonmagnetic substrate block as shown in FIG.

Next, a plurality of non-magnetic substrates are laminated and the joined blocks are cut at right angles to the laminating plane as shown by the chain line to form a plate as shown in FIG. 4 (b). 4 (b), the plate surface and the metal magnetic film 2 are cut in a strip shape so as to be orthogonal to each other, as indicated by a dashed line,
A pair of head core blocks 1 as shown in FIG.
3 and 14 are produced. Next, as shown in FIG. 4C, a coil groove orthogonal to the metal magnetic film 2 is formed on the gap facing surface of at least one head core block, and the gap facing surfaces of both head core blocks 13 and 14 are mirror-finished. Then, a SiO ₂ thin film having a thickness corresponding to the gap width is formed as a gap spacer on one or both of the head core blocks facing the gap by a sputtering method, and then the head core blocks 13 and 14 and the magnetic gap 8 are formed. The metal magnetic films 2 of the respective cores are aligned and positioned under pressure while being held, and bonding is performed.

Next, the cutting process of the magnetic head will be described with reference to FIG. FIG. 5A is a perspective view of the head core block to which the magnetic head in the embodiment of the invention is bonded, and FIG. 5B is a sectional view of the head core block of the magnetic head according to the embodiment of the invention. It is a perspective view showing a state. As shown in FIG. 5A, the bonded head core blocks 13 and 14 are shown in FIG.
1 was cut, cut into a predetermined shape, and subjected to steps such as polishing (not shown) to form a magnetic head as shown in FIG.

Performance comparison tests were carried out on the magnetic head in one example of the present invention manufactured as described above by changing the film thicknesses of the adhesive glass and the oxide thin film. The results will be described below.

(Experimental Example) According to the manufacturing method shown in this example, the total thickness of the adhesive glass and the oxide thin film was 0.5 μm.
A plurality of different core blocks were produced within a range of 1.5 μm, and a magnetic head was produced from each core block. With respect to each magnetic head, the coefficient of friction after the CSS test and the defective rate of adhesive peeling were examined. The result is shown in FIG. Figure 6
FIG. 3 is a diagram showing the dependence of the coefficient of friction and the peeling failure rate after the CSS test on the total thickness of the adhesive glass and oxide thin film of the magnetic head.

As is apparent from FIG. 6, 0.5 μm
By setting the thickness to 1.5 μm, it was possible to eliminate the dent in the bonded glass bonding portion and improve the CSS characteristics.
In addition, the defective rate due to peeling of the adhesive could be suppressed to about 5%.

(Comparative Example 1) By the same method as in Example,
The total thickness of the adhesive glass and the oxide thin film is 0.1 μm to 0.4
A plurality of core blocks different in the range of μm were produced, a magnetic head was produced from each core block, and the coefficient of friction after the CSS test and the defective rate due to peeling of the adhesive were examined. The result is shown in FIG. It has been found that when the total film thickness is 0.4 μm or less, the defective rate due to peeling of the adhesive becomes 10% or more, and then increases sharply thereafter. This is because when the thickness of the adhesive glass becomes thin, the adhesive strength decreases, and when the thickness of the oxide thin film becomes thin, the effect of preventing the reaction erosion between the metallic magnetic film and the non-magnetic substrate and the adhesive glass decreases, and the adhesive strength decreases. It is thought to be to do.

Comparative Example 2 By the same method as in Example,
The total thickness of the adhesive glass and the oxide thin film is 1.6 μm to 1.9.
Fabricate multiple core blocks with different sizes up to μm,
A magnetic head was produced from each core block, and the coefficient of friction after the CSS test and the defective rate due to peeling of the adhesive were examined. The result is shown in FIG.

As is clear from FIG. 6, the total film thickness is 1.5.
It has been found that when the thickness exceeds μm, the friction coefficient becomes 0.5 or more and increases rapidly thereafter. Then, when the step difference of the adhesive glass joint part was measured by a stylus type surface roughness meter for the magnetic head in which the total thickness of the adhesive glass and the oxide thin film after final finishing was 1.8 μm, a dent of 50 nm to 150 nm was found. Had been formed. Furthermore, the CS of this magnetic head
When the sliding surface of the head medium was observed after the S test, deposits were present in the dents in the adhesive glass portion. It is considered that the friction coefficient increased due to this.

Therefore, from the above, the total thickness of the adhesive glass and the oxide thin film of the magnetic head of this embodiment is 0.4 μm.
.About.1.7 .mu.m, preferably 0.5 .mu.m to 1.5 .mu.m, it was found that sufficient adhesive strength is maintained in the adhesive glass portion and the CSS characteristics are excellent.

In this embodiment, the metal magnetic film 2 is made of Fe-
Although an Al-Si alloy was used, the same applies when an amorphous alloy film or a nitride alloy is used.
7 is not limited to SiO ₂ , but other oxides such as Al ₂ O ₃ ,
TiO ₂ has the same effect. Furthermore, forsterite (MgO-SiO), which is a complex oxide, is used as an oxide thin film.
₂ type) or zircon (ZrO ₂ —SiO ₂ type) or the like may be used.

[0028]

As described above, according to the present invention, the total thickness of the adhesive glass and the oxide thin film is set within the range of 0.4 μm to 1.7 μm, preferably 0.5 μm to 1.5 μm. It is possible to eliminate dents at the joint portion and improve CSS characteristics. Furthermore, since sufficient adhesive strength can be obtained at the adhesive glass part, high quality and high yield reliability that can reduce defects such as peeling of the adhesive part,
It is possible to realize a magnetic head with excellent productivity.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a magnetic head according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of part A of FIG.

FIG. 3A is a sectional view showing a first non-magnetic substrate forming step of a magnetic head according to an embodiment of the present invention. FIG. 3B is a second non-magnetic substrate forming step of a magnetic head according to an embodiment of the present invention. (C) A perspective view showing a state in which non-magnetic substrates of a magnetic head in one embodiment of the present invention are joined together.

FIG. 4A is a perspective view of a main part of a laminated block in which a plurality of nonmagnetic substrates of a magnetic head according to an embodiment of the present invention are laminated. FIG. 4B is a nonmagnetic substrate plate of a magnetic head according to an embodiment of the present invention. (C) Perspective view of main part of head core block of magnetic head in one embodiment of the present invention

FIG. 5A is a perspective view of a head core block to which a magnetic head of the present invention has been bonded, which has been bonded; FIG. 5B is a perspective view showing a state in which the head core block of the magnetic head of the present invention has been cut.

FIG. 6 is a diagram showing the dependence of the coefficient of friction and the peeling failure rate after the CSS test on the total thickness of the adhesive glass and the oxide thin film of the magnetic head.

FIG. 7 is a perspective view of a main part of a conventional magnetic head.

8 is a partially enlarged view of part A of FIG.

[Explanation of symbols] 1 slider 2 metal magnetic film 3 first non-magnetic substrate 4 second non-magnetic substrate 5,10 first oxide thin film 6,11 adhesive glass 7,12 second oxide thin film 8 magnetic Gap 9 Winding groove 13,14 Head core block

Claims (2)

[Claims] 1. A first magnetic thin film deposited on the surface of a non-magnetic substrate to form a first oxide thin film on the surface of the metallic magnetic film.
A non-magnetic substrate and a second non-magnetic substrate having a second oxide thin film formed on the surface of another non-magnetic substrate with an adhesive glass, the magnetic head having a film thickness of the adhesive glass. And the total thickness of the first oxide thin film and the second oxide thin film fused by the adhesive glass is 0.4 μm to 1.7.
A magnetic head having a thickness of μm, preferably 0.5 μm to 1.5 μm. 2. The film thickness of the adhesive glass is from 0.1 μm to 1.
The magnetic head according to claim 1, wherein the magnetic head has a thickness of 0 μm, preferably 0.2 μm to 0.8 μm.