JPS59135613A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the workability and to increase the adhesive stength of the substrate to the thin film by forming a thin film of a specified amorphous magnetic alloy on a glass substrate having a specified coefft. of linear expansion. CONSTITUTION:A thin film of an amorphous magnetic alloy having a composition represented by a formula TxXy is formed on a glass substrate having 80- 130X10<-7>deg<-1> coefft. of linear expansion at 25 deg.C. In the formula, T is Co or a combination of Co with one or more kinds of other transition metallic elements, X is one or more kinds of vitrifying elements, x+y=100atom%, and (y) is 5-35atom%.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Background of the Invention Technical Field The present invention relates to a magnetic head. More specifically, the present invention relates to a magnetic head having an amorphous magnetic alloy thin film.

Prior art and its problems Because it exhibits high saturation magnetization and high magnetic permeability.

Amorphous magnetic alloy thin plates are attracting attention as magnetic head materials.

A narrow magnetic head with a track l] made of an amorphous magnetic alloy thin plate, for example, for video recording, recording or reproducing, or T'i N''
To form a rotating head or a magnetic head for an electric machine, 'J, a thin plate of CO-based amorphous magnetic alloy can be used as it is, or a plurality of sheets can be laminated to form a tens of pL.
track r with a thickness of approximately 20 to 30 m, especially about 20 to 30 lm
A core with a predetermined shape as l! The i-body is made by butting each other through a gap.

However, heads for videos and the like manufactured in this manner have disadvantages in that they are extremely thin and therefore not strong, deform during mechanical processing, and have poor dimensional accuracy after fusing.

Furthermore, since the thin plate of amorphous magnetic alloy has high elasticity, it deforms as it slides at high speed with the video magnetic recording medium, causing the head arm to become unbalanced and resulting in poor rotational running performance.

In order to eliminate such inconveniences, it is conceivable to form a thin film of an amorphous magnetic alloy by sputtering on a predetermined substrate to form a half-core core, and then form a magnetic head from this. In the magnetic head formed in this manner, the above-mentioned disadvantages are eliminated.

However, when making a magnetic head by depositing a CO-based amorphous magnetic alloy thin film on a normal material such as alumina, it is necessary to process the shape of the core half-way or create a gap to create a so-called azimuth structure. Processability is poor, such as surface grinding under pressure and polishing oil.

Further, there are disadvantages in that the adhesion strength between the substrate and the thin film is low, the adhesion strength when the thin film is applied is low, and it may peel off during heat treatment. Furthermore, the thin film peels off during shape processing, resulting in poor manufacturing yields.

There is also the disadvantage that the characteristics deteriorate due to strain applied during adhesion and heat treatment.

II. Purpose of the Invention The present invention was made in view of the above-mentioned circumstances, and its main purpose is to provide good processability, high adhesion strength between the substrate and the thin film, high manufacturing yield, and high manufacturing speed. The object of the present invention is to provide a magnetic head with less deterioration in characteristics.

Such [-1 objective is achieved by the present invention described below.

That is, the present invention has a linear expansion coefficient of 80 to 30. X 10 =7deg-'
This magnetic head is characterized by forming a thin film of an amorphous magnetic alloy on a glass substrate.

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

In the present invention, the substrate on which the amorphous magnetic alloy thin film is formed is glass. Therefore, the additivity is good.

The linear expansion coefficient (25°C) of glass is 80 to 1
It is 30×10""deg-'.

m, oat tension coefficient is 80 X I O-0-7de'
If it is less than that, the adhesion strength during thin film deposition will be low, and the characteristics will deteriorate due to distortion during deposition.

-・If you exceed 130 x 10-0-7 de',
During heat treatment, peeling occurs or distortion occurs, resulting in property deterioration. Furthermore, outside the range indicated by ``-'', peeling during shaping In will also increase, resulting in a decrease in yield.

Flint glass is particularly suitable as a glass having such physical properties, and among these, KF2, LLF2
, LF4, F2, SF2.5F13, KzF2, soda glass, lead glass, etc. are preferred.

be.

There is no particular restriction on the thickness of such a glass substrate, but it is usually about 0.1 to 51 lffl. The shape of the base may be a known half-core shape.

The magnetic thin film formed on such a substrate -1- is in an amorphous state with substantially no long-range regularity.

There is no particular restriction on the M1 composition of the amorphous magnetic alloy thin film, but in particular, f+Y is expressed by the following formula.
Delicious.

Where T represents CO or a combination of CO and another transition metal element.

That is, T may consist of Co q-G, or C
It may also consist of O and another transition metal element.

When T consists of CO and other transition metal elements, the other transition metal elements include Fe and Ni.

Cr, Mo, W, V, Nb,
T a , T i , Z r.

Hf, Mn, Pt, Ru, Rh, Pd, Os.

One or more types such as Ir can be cited as specific examples, but the total amount thereof is preferably 38 at% or less.

Among such additive elements in T, one preferable example is Ru. Ru has a great effect in improving high-speed abrasion resistance and preventing a decrease in output when using metal tape (coated tape using alloy magnetic powder).

In this case, the Ru additive is 8 at% or less, especially 0.5 to
It is preferably 6 at%, more preferably 1 to 5 at%.

Another preferred element is Cr.

By adding Cr, high-speed wear resistance and storage stability under high temperature and high humidity conditions are significantly improved.

In this case, the amount of Cr added is 8 at% or less, especially 0.5 to
It is preferably 6 at%, more preferably 0.5 to 5 at%.

In addition, +71 VIB group, VB group, TVB group elements other than Cr, M o , W , V , N b , T
It is also preferable to add one or more of a, Ti, Zr, and Hf. These additions improve high-speed wear resistance under high temperature and high humidity conditions.

In this case, these additions include up to 5 at%, especially 0.
It is preferably 1 to 2 at%.

Further, when Ru, more preferably Ru+Cr, and even more preferably Ru+Cr+ (other IVB to IVB group elements) are included, even more favorable results can be obtained. .

Furthermore, other additive elements may include Fe. Addition of Fe reduces magnetostriction.

In this case, the amount of Fe added is 6 at% or less, especially 0.1 to 6 at%.
It is preferable that it is at%, more preferably 2 to 5 at%.

Furthermore, Ni may be included.

Nr replaces CO and reduces material cost, but the amount added is preferably 1 oat% or less.

In addition, Mn is also a suitable additive element.

On the other hand, or one insert of vitrification elements.

Vitrification elements include B, Si, P, and C.

There are AI, etc., and any one or more of these may be used, but it is particularly preferable to use B or St and B as essential components.

In this case, B is 10 to 35 at%, and if necessary, Si is 6
When the content is at % or less, wear resistance is improved and favorable results are obtained.

And the atomic ratio of Si/(Si+B) is O or 0.2
Below, especially when it is 0.05 to 0.15, even more favorable results can be obtained.

In addition, when P, C, AI, etc. are further contained, it is preferable that these are 0.5 at% or less.

Such a thin film is typically deposited on a substrate in an amount of 0.1 to 100 g.
m, preferably 0.1 to 30 gm.

In order to form an amorphous magnetic alloy thin film on such a substrate, a vapor phase deposition method 1 is usually used, typically by sputtering.

Any known sputtering method may be used, in which a target is sputtered using bombarded ions, and the target material is evaporated with a slow energy of several eV to approximately 100 eV.

Therefore, even if a plasma method is used in which the target is sputtered with ions such as Ar caused by abnormal glow discharge in an inert gas atmosphere such as Ar,
An ion beam method in which ion beams such as , Xe, etc. are irradiated may be used.

When using a plasma method, it may be so-called RF sputtering or so-called DC sputtering,
The device configuration may be either 2-pole, 4-pole, etc.
Furthermore, so-called magnetron sputtering may be used. In some cases, so-called reactive sputtering may also be used. Furthermore, various methods can be used as the ion beam method.

In normal cases, an fJ alloy with a corresponding composition may be used as the target.

Note that there are no particular restrictions on the operating pressure, plate voltage, plate current, gap between electrodes, etc., and these 1 can be set to arbitrary values depending on the conditions.

In such a case, an underlayer may be formed on one surface of the body (1), and an amorphous magnetic alloy thin film may be formed on this underlayer. ”An additional protective layer may be formed.

Furthermore, amorphous magnetic alloy thin films and non-magnetic thin films can be alternately laminated.

The substrate 2.2' on which the amorphous magnetic alloy thin film 3.3' is formed is processed into a predetermined shape, such as a 1-shape, a C-shape, etc., as shown in FIGS. 1 and 2. Core half of 1.1
', and are brought together at the front gear pump section 4 and the rear gap section via a gap material 40 such as 5i02 to form a magnetic head. In this case, it is preferable that at least the abutting surfaces of the front gap portion be inclined from the normal to the thin film forming surface to form a so-called azimuth angle.

Furthermore, on the thin films 3 and 3' of the core halves l and 1', there is further a substrate? , 2' can also be bonded with a protector 5 made of the same material.

In such a case, after forming the thin film, it is preferable to perform heat treatment in a non-magnetic field or in a static magnetic field or a rotating magnetic field, if necessary.

Next, it is ground into a predetermined shape, and if necessary, it is ground to a predetermined thickness, and if necessary, it is further polished to make the core semi-dry.

Then, winding 8 is applied, alignment is performed as described above, and other necessary processing is performed, and the magnetic head is fixed to a support 9 to produce a magnetic head.

Note that the above heat treatment may be performed after the shape processing L and before winding.

(2) Specific effects of the invention Such a magnetic head is extremely useful as a rotary head for video recording, recording/playback, audio, etc., or a magnetic head for computers.

Since the magnetic head of the present invention uses a glass substrate with a predetermined coefficient of linear expansion, it has good workability, and the shape processing when making the core half-open, and the gap abutting surface from the normal to the thin film forming surface. There is little damage even during the grinding process to tilt and set the azimuth angle, and the subsequent polishing process.

Further, the adhesion strength between the substrate and the thin film is high, the adhesion strength when the thin film is applied is high, and peeling due to heat treatment is extremely small. Furthermore, there is very little peeling during shaping, and the manufacturing yield is extremely high.

In addition, since less distortion occurs during adhesion and heat treatment, there is less deterioration of characteristics.

(2) Specific Examples of the Invention Hereinafter, specific examples of the present invention will be shown and the present invention will be explained in more detail.

Example 2 ■ Thick, 2 inch square KF2 glass substrate (86X l
O-0-7de', Hv = 480), quartz glass-7-1 substrate (5X10 deg, Hv = 500) and alumina substrate (67X l O-0-7de', l
(v = 1500) 1-, a thin film of an amorphous magnetic alloy having the composition shown in Table 1 below was formed to a thickness of 30 Ij and m.

The thin film was formed by sputtering.

In this case, a cast alloy of the corresponding composition is used as the target, and the operating argon pressure is 5.
3Torr, plate voltage 2KV, input power 4W/
RF magnetron sputtering was performed at crn'.

Next, this was cut into 2 x 2 mm to make a total of 180 chips, which were then ground and polished to obtain a core half l,1 as shown in Figs. 1 and 2.
0.3 μm after heat treatment in a rotating magnetic field at 50°C
They were brought together via a front gap material 5i02, and a predetermined contour line 8 was applied to produce a magnetic head. Note that the azimuth angle was 6°.

Next, each magnetic head was mounted on an 8 mm video deck, and the following measurements 1) to 3) were performed.

1) Manufacturing yield The number of defective products out of a total of 160 cores was calculated.

2) Wear amount The metal tape was run for 500 hours at 25°C, 50% RH and 40°C, 70% RH, and the wear amount after running (
gm) was measured using a surface roughness meter.

3) Storage property After storing for 240 hours at 70°C and 195%RH,
The f-characteristic deterioration (dB) at 0.5 MHz and 15 MHz before and after storage was measured.

These results are shown in Table 1.

From the results shown in Table 1, the effects of the present invention are clear.

[Brief explanation of the drawing]

1 and 2 show one example of the structure of the magnetic head of the present invention.
1 is a perspective view, and FIG. 2 is an enlarged partial front view. ], 1'...Core half 2.2'...Substrate 3.3'...Amorphous magnetic alloy thin film application Person Tokyo Denki Kagaku Kogyo Co., Ltd. Representative Patent Attorney Yo Ishii - 8 84-

Claims (1)

[Claims] 1. A magnetic head characterized by forming a thin film of an amorphous magnetic alloy on a glass substrate having an expansion coefficient of 80 to 130Xlo-7deg-'. 2. Thickness of thin amorphous magnetic alloy is 0.1 to 100 gm
A magnetic head according to claim 1. 3. The magnetic head according to claim 1 or 2, wherein the amorphous magnetic alloy has a composition represented by the following formula. In the two-legged formula, T represents a combination of COI or C and one suffix of another transition metal element - and X represents one suffix of a vitrifying element -L. X+y = 100 at%, of which y is 5 to 35 at%.)