JPS60195709A - Magnetic head - Google Patents

Abstract

PURPOSE:To eliminate the influence of an artificial gap and to improve the manufacturing yield of a magnetic head, so as to reduce the cost of the magnetic head, by installing a ferromagnetic thin metallic film formed on a ferromagnetic oxide to the tape contacting surface of the magnetic head with an oxide glass in between. CONSTITUTION:The front end part of the projected part 11' of a magnetic core half body 11 of a ferromagnetic oxide film is formed to have a width slightly narrower than a track width (t) and a section 11'' having a triangular cross section is filled with molten high-melting point oxide glass 13. Then the part from the outer surface of the section 11'' to the front end part of the projected part 11' is covered with a ferromagnetic thin metallic film 12 made of ''Sendust'', etc. Moreover, after filling both outsides with reinforcing glass 14, a magnetic gap (g) is formed with the thin metallic film 12 at the front end part of the projected part 11'. Because of the oxide glass filled section formed in the vicinity of the magnetic gap (g), the connection between the projected part 11' and ferromagnetic thin metallic film 12 is improved and the action of the gap (g) as an artificial gap is reduced. In addition, since the adhering strength of the metallic thin film is increased, manufacturing yield of this magnetic head can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head, and more particularly to a magnetic head made of a composite magnetic material of a ferromagnetic oxide material and a ferromagnetic metal material.

Background Art and its Problems For example, as the density of signals magnetically recorded on magnetic tape, which is a magnetic recording medium for VTR (video tape recorder), increases, magnetic tape has a high residual magnetic flux density B.
Metal chives and the like having r have been used. It is necessary to increase the strength of the magnetic field generated from the magnetic gap of the magnetic head company used for magnetic tapes with high coercive force Ha such as metal tapes. Also, as the density of recorded signals increases, the magnetic head tracks It is necessary to narrow the width.

Therefore, various types of magnetic heads have been proposed in the past, and the head shown in FIG. 1 is known as a narrow track magnetic head.

In the head shown in Fig. 1, most of the head is made of non-magnetic material (IA), (IB) such as glass.
A ferromagnetic metal thin film (2) with a film thickness equal to the track width is provided in the central region of the head so as to be sandwiched between IA) and (IB). This metal thin M(2) is formed by depositing a high magnetic permeability alloy such as sendust on one core-shaped non-magnetic material (IA) using a vacuum thin film forming technique such as sputtering. Such a magnetic head can form a very narrow track width due to the structure of the head, but since the magnetic path of the magnetic head is only made of thin metal M(2), the magnetic resistance is large and it is unfavorable in terms of efficiency. Thin film (2
) needs to be formed with a film thickness equal to the track width using the vacuum thin film forming technology of S. Datsuteringo.The film growth rate using this vacuum thin film forming technology is extremely slow, so it takes time to fabricate the head, especially when it comes to the track width. The wider the width, the thicker the metal thin film (2) must be, which has the drawback of requiring a longer time to manufacture the head.

Furthermore, since the film forming area of the metal thin film (2) is large, there is a problem that, for example, the number of pieces that can be processed at one time by a spooling device is limited, making it impossible to expect an improvement in mass production. Since this is performed by butting K of the thin metal M(2), which has a very thin film thickness, there is also the problem that the reliability of the gap accuracy decreases.

In order to solve this problem, a magnetic head is known that is made of a composite magnetic material and has a ferromagnetic metal thin film formed on the magnetic gap forming surface. As shown in Figure 2, this magnetic head has a core half open (1 m).

(1b) is made of a ferromagnetic oxide such as Mn-Zn 7-alite, and there is a protrusion (1m') of optical ferrite protruding from the side where the magnetic gap g is formed, and sendust from the front side to both sides of (lb'). Thin films (2a) and (2b) are deposited, and glass for accompaniment (3) is filled on both sides of the magnetic gap g. This magnetic head forms a magnetic gap g using Sendust Thin II (2m) and (2b) which are adhered to the front end of the protrusion (1b).

This magnetic head line is #1 compared to a conventional ferrite head by simply forming a Sendust thin film on the gap surface of the conventional ferrite head using a method such as Sumi9 Ivy. Similar to ty, it is inexpensive and easy to use, and even if the track width is wide, there is no need to increase the thickness of the sendust thin film accordingly, and the film can be formed on a head with any track width using the same process. Since the thickness of the thin film only needs to be several microns regardless of the track width, this also makes it possible to obtain an inexpensive magnetic head.

However, in the magnetic head shown in FIG. 2, the mechanical bond between the 7E2ite and the Sendust thin film cannot be completely formed, and a so-called pseudo gap is formed between the ferrite and the Sendust thin film. The problem was that it was bad. That is, as shown in the enlarged view of the tape contacting surface of this magnetic head in FIG.
Not only can the reproduction output signal be obtained at the non-magnetic gap material (4) such as
Ferrite protrusion (1m') of (lb), (lb)
and Sendust Thin IF (2m).

There is also a problem in that at the interface with (2b), although the reproduction output is smaller than the reproduction output due to the above-mentioned main gap, it is still possible to obtain a reproduction output.

Therefore, in the past, core half-rest (Im), (lb
), pre-treatment conditions, pre-heating conditions during sendust thin film sputtering, speed of sputtering, temperature conditions during sputtering, cooling conditions after sputtering, glass fusion It is possible to obtain a head that is less affected by pseudo gaps by manufacturing the head with sufficient control of manufacturing conditions, processing conditions, etc. Therefore, although the magnetic head shown in Figure 2 essentially has excellent linear performance and is theoretically inexpensive, the manufacturing conditions are strictly controlled, resulting in low yields and high prices. There was an inconvenience.

Purpose of the Invention The present invention takes into account these points, and even under loose manufacturing control conditions, it has performance equivalent to that of the magnetic head shown in FIG. 2 without the influence of pseudo gaps, and has a high yield and low cost. The present invention provides a magnetic head that is compatible with metal tape recording and playback.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention forms a ferromagnetic metal thin film by vacuum thin film formation technology on the joint surface of a magnetic core semi-dead pair made of ferromagnetic oxide, and A magnetic head in which a ferromagnetic oxide and a ferromagnetic metal are disposed on the tape contacting surface with two oxides interposed therebetween. , Before giving a detailed explanation of the present invention, a detailed explanation of the present invention will be given.

The state of formation of the magnetic metal thin film (sendust film) of the magnetic head shown in FIG. 2 above using the vacuum evaporation cape is as shown in FIG. On top of (1) Sendustsuno Ivy Farm (2
) is formed in the direction of the arrow in the same figure (B in the same figure). At that time, the Senmestos f ivy film (2) is the ferrite block (
Film formation progresses in a state in which the film is in continuous contact with 1) over a long distance. In this state, the surface of the ferrite block (1) is covered with a dust scattering film (2), and the ferrite block (1) is exposed to high temperatures (300C to 700C) while in contact with metal. Of the ferrite constituent atoms, oxygen is Sendustos i! 300 between the ivy film and the ferrite block
Diffusion is started aiming for an equilibrium state at ~500 CK. That is, in the direction of connection with kl, 81, and P@ in sendust, the vicinity of the surface of the ferrite is toward one element,
The higher the temperature and the longer the exposure time, the lower the oxygen level.

Furthermore, the coefficient of thermal expansion differs by about 50% between sendust and ferrite (Sendust: 13 (1-160X10 1
cz ferrite: 9 to 110 At high temperatures, since the interface is exposed to high temperatures with strain applied to it, a so-called strain aging condition is created, and the movement of oxygen near the interface is accelerated.

As described above, it is thought that the strain and the movement of oxygen from the ferrite to the sendust at the interface confined between the sendust/ramie vine film and the ferrite block are the causes of the appearance of the pseudo gap.

In the present invention, as a means to alleviate this situation, a glass nozzle zone is provided at least in a part of the interface between the ferrite block and the ferrite block as a ferromagnetic oxide, and the ferrite block and the ferrite block are bonded to each other. In addition to dispersing the strain in the ferrite film, it is intended to prevent the ferrite near the interface from becoming hypoxic by supplying oxygen in addition to the glass near the interface during high-temperature heating. be.

Next, embodiments of the present invention will be described based on the drawings.

FIG. 5 shows the first embodiment, and this figure shows an enlarged view of the magnetic tape contacting surface of the magnetic head.

A magnetic head made of this composite magnetic material has, for example, a pair of magnetic cores in which half-holes (lla) and (llb) are Mn-zn.
A film is formed of a ferromagnetic oxide having high magnetic permeability such as Ni-Zn 7elite) and Ni-Zn 7elite, and protrusions (l1m') and (llb') are formed on the side where the magnetic gap is formed. These ferrite protrusions (l1m'), (llb
The joint surface of the tip of ') is parallel to the gap surface and the track @
Both side parts are cut out so that the width is slightly narrower than 1, and this protrusion (l1m') = (llb both side parts, i.e.,
It is filled with the tip edge of the protrusion, and this core is half closed (l
1m) = protrusion (l1m') of (ITo), (
Sendust-covered ferromagnetic metal thin films (12m) and (12b) are formed on the top surface of the ferromagnetic metal thin film (12m) and (12b) from the tip surface to both sides, that is, from the filling part K of the high-melting-point oxide glass Q1.

In addition, the track width regulating recesses (11m') and (iib"
), that is, ferromagnetic metal thin II (12m), (12
Both sides of b) are filled with reinforcing f lath a◆, using ferromagnetic metal thin films (12m) and (12b) adhered to the tip surfaces of the projections (l1m') and (llb'). and forms a magnetic gap g.

Further, FIG. 6 shows another embodiment, in which a part of the protruding part of the core half-closed is coated with a film of high melting point oxide. In other words, in this example, the core half holiday (2
1m), the protrusion (21m') of (21b).

The notch forms parts (21m') and (21b') in the part including a part of the tip surface of (21b'), and this notch forms parts (21m") and (21b') of the high melting point of K. A gap-forming protrusion is formed by melting and filling oxide glass, and ferromagnetic metal thin films (22m) and (22b) such as sendust are deposited on this protrusion in the same manner as in the above embodiment. to form a magnetic gap g equal to the track width, and the track center regulating recesses (21m') and (21b') on both sides of this magnetic gap g are filled with 2 reinforcing gases (c). In this way, the magnetic heads shown in FIGS. 5 and 6 have cores half-open (l1m) (Ilb) and (
21m) (21b) and the protrusion (flb') forming the magnetic gap g of (21b) and (21a') (21b
') is filled with high melting point oxide glass Q] and (to), and this protrusion (11a') (llb
') and (21a') (21b and glass 01 and 21b) and ferromagnetic metal thin film (12m) such as sendust (
12b) and (22a) By depositing (22b), the mechanical adhesion between the ferrite that forms the half-core core and the metal thin film such as sendust is perfect, and the ferrite and sendust interface forms a pseudo gap. This reduces the possibility of this acting as a

Moreover, FIG. 7 shows a case where most of the protruding parts of the core half-hole are replaced by laths with a high melting point oxide. That is, in this example, Mn-Z
A half-core core (31m) formed by n-ferrite town,
(31b) protrusion (31a'), (31b')
Cut off the front half of the
A gap-forming protrusion is formed by melting and filling b') with a high-melting-point oxide glass, and the remaining protrusion (31a') is formed from the surface of this protrusion, that is, the filled part of the oxide glass.
(31b') and a ferromagnetic metal thin film such as Sendust (
32m).

(32b) is deposited to form a magnetic gap g. Similarly, in this example, the track width regulating recesses (31a') (31b) on both sides of the magnetic gap g are filled with reinforcing glass (b).

In this example formed in this way, there is no interface between the ferromagnetic metal thin films (32a) (32b) and the ferrite protrusions (31a') (31b') in the gap part, so there is no pseudo gap at all. The LD film thickness of these ferromagnetic metal thin films (32a) and (32b) was reduced to 10-20
By making it approximately jJ, it becomes suitable as a digital recording head with a wavelength of 5 μm or less.

As described above, a ferromagnetic metal such as sendust is sputtered to cover the surface of the gap-forming protrusion on the half-closed core formed of ferromagnetic oxide such as Mn-Zn 7-elite, thereby injecting ferromagnetic material into the gap. When manufacturing a magnetic head with a metal thin film arranged thereon, the bond between the core semi-vacant protrusion and the ferromagnetic metal thin film can be enhanced by providing a filling portion of oxide glass in at least a part of the vicinity of the gap between the core semi-vacant protrusion. ,
The yield rate is improved by reducing the effect of a pseudo gap and by increasing the adhesion strength of the ferromagnetic metal film.

Next, the manufacturing process of an example of the magnetic head according to the present invention will be explained based on FIGS. 8 to 13.

First, as shown in FIG.
1-Ferromagnetic oxide block such as Zn ferrite (41)
There is a protrusion (41') slightly narrower than the track width from the front ridge of the gap abutment surface (41m).
Two adjacent flat grooves (41"), (41")
A plurality of sets of grooves are formed using a rotary grindstone or electrolytic etching. That is, the groove (+r).

(41//) is formed in a portion corresponding to the vicinity of the magnetic gap forming position of block (41).

Next, as shown in FIG. 9, the grooves (41"), (41")
A high melting point oxide glass sakaki is melted and filled into the gap, and the gap abutting surface (41m) and the front surface (41b) are polished.

Then, as shown in FIG.
1').

(41') r (41')
) to form. The kerf (41') formed at this time
, (41') to obtain the core semi-dead blocks (41A) (41B) in which a part of the glass sakaki remains laminated on the upper surface side of the protrusion (41') and (41). A pair of blocks is prepared, and a coil winding groove (2) is formed in at least one of the core half-closed blocks (41A) (FIG. 11).

Next, as shown in FIG. 12, the core half-dead block (41A
) (41B) with cut grooves (41 and one block (4
In 1A), a ferromagnetic metal such as sendust is deposited and laminated on the entire surface of the gear lug mating surface (41 m), including the coil winding groove θ A thin film (6) is formed.

As this ferromagnetic metal, Sendas) (Fs-At-8
1 alloy), crystalline alloys such as Ni-Fs gold alloy, metal-metalloy alloy (Co-F・-81-
B), metal-metal alloys (Co-Ti, Co-M
Amorphous alloys such as o-Zr) can be used.

Then, the kerf (41) is coated with the ferromagnetic metal thin film (6).
(41A) is melted and filled with glass (B) having a lower melting point than the above-mentioned glass (A), and one half-core block (41A) has winding grooves (41A) and the other half-core block has no grooves. (41B) are butted against each other so that the track portions, that is, the protruding portions (41') and (41) are aligned, and gap welding is performed as shown in FIG. (The gap spacer is made of low melting point glass filled with 41 #8102 r ZrO2* Ba2O
3°Cr or the like can be used. In addition, both blocks (4
1A) (41B) are joined by inserting a glass rod into the butt winding groove (■) and the glass groove (not shown) without filling the cut grooves (41 with glass) and melting them. In particular, this can also be done by fusion bonding.

This combined block (410) is shown in FIG.
A plurality of head chips are obtained by slicing at the position of line , /+a/ II. This slicing process may be performed at an angle of the azimuth angle.

Next, the surface of the thus obtained head chip that faces the magnetic tape is polished with a gold cylinder to obtain the magnetic head shown in FIG. 14. In this magnetic head, as shown in FIG. 15 showing the magnetic tape contact surface, the gap g between the two core halves (41A) (41B) is formed, that is, the protrusion (41A') (most of 41B is made of oxidized metal). When Sakaki is replaced, the gap forming part is a magnetic metal thin film directly attached to the glass (A)!I! (4
2AX42B), a narrow track composite type magnetic head according to the present invention can be obtained.

Next, an example of a magnetic head manufactured by another manufacturing process will be explained based on FIGS. 16 to 21.

First, as shown in FIG. 16, a surface (51
grooves (51") at the required intervals on the front surface (sx
It is formed from b) to the rear surface. This groove machining is performed by polishing with a rotating grindstone, electrolytic etching, or the like.

Next, as shown in FIG. 17, the grooves (51") (51") are melted and filled with high melting point oxide glass, and then the gap abutting surface (51m) and the front surface (51b) are polished.

Then, as shown in Fig. 18, high-melting point glass rings are filled to create nine grooves (51') and grooves (51') that overlap a part of 51 and are slightly narrower than the track width. “) and a plurality of grooves (51, (
51#) is formed. The protrusion left at this time (51'
), (51') gap butting surface (51m)
Oxide glass is exposed on the side.

Next, as shown in FIG.
A ferromagnetic metal such as sendust as described above is deposited on the front surface (51b) and the circumferential surface using a vacuum thin film forming technique similar to that of a scattering method to form a ferromagnetic metal thin film ring.

In this way, the core half-dead blocks (51A), (51B
). And one core half-vacation block (51A)
K-C Groove the winding groove as shown in FIG. 20.

Next, one of the core half-dead blocks (51
A) and the other core semi-dead block (51B) without grooves are butted against each other at their respective gap butting surfaces so that the track portions or protrusions (51') are aligned, and cut grooves (51, (51) are formed. P-joining is performed using a low melting point glass rod that is melted and filled into the two parts.In this case, the notch provided at the winding groove axis and the rear joint part is heated by inserting a low melting point glass rod into the groove (not shown). While applying pressure, the ear parts are fused and integrated as shown in Figure 21.The joints of both Zoroku (51A) and (51B) are made by cutting grooves (J') and (51) in the state shown in Figure 19. It is also possible to melt and fill a low melting point glass and then melt this glass.

This combined block (310) is shown in FIG.
, b'-b'li to obtain a plurality of head chips. Note that in this slicing process, slicing may be performed with an azimuth angle tilted depending on the case. By cylindrical polishing the magnetic tape facing surface of the head chip obtained in this way,
A magnetic head shown in FIG. 22 is obtained.

In this magnetic head, as shown in an enlarged view of the tape contacting surface in FIG. A film is formed on the fermented glass ring over approximately half of the side, and the gap forming part is covered with a magnetic metal thin film (
A narrow track composite type magnetic head according to the present invention can be obtained with the structure in which the magnetic metal thin films (52A) (52B) Ic A good film is formed, and both core halves (51AX51B) are fused from the tape facing surface to the rear end surface with a glass plate to improve bonding strength.

In the magnetic head of the present invention obtained as described above, a gas-snowing zone is provided between the magnetic core made of ferromagnetic oxide forming the gap and the magnetic metal thin film. In order to disperse the strain between the glass and the magnetic metal thin film and to supply excess oxygen to the glass near the interface during high-temperature heating, we reduced the oxygen content of the ferromagnetic oxide, which is the material of the magnetic core near the interface. This increases the coupling between the magnetic core and the magnetic metal thin film, reduces the magnetic gap effect, and further increases the mechanical bonding strength of the metal magnetic thin film, improving yield and increasing reliability. A magnetic head is obtained.

As detailed in the detailed description of the invention, the composite magnetic head of the present invention has increased mechanical adhesion strength of the magnetic metal thin film to the magnetic sulde magnetic core compared to conventional composite magnetic heads, and can be used even under loose manufacturing control conditions. Most of the effects are due to pseudo gaps.It has a high yield rate, excellent mass production, and high reliability.For example, it is possible to obtain a magnetic head that can record and play back magnetic tapes with high coercive force H (1) such as metal tapes. .

[Brief explanation of the drawing]

1 and 2 are perspective views of a conventional composite magnetic head, FIG. 3 is an enlarged plan view showing the tape contacting surface of the composite magnetic head of FIG. 2, and FIGS. 4A and B are FIG. 5 is a partial manufacturing process diagram of a conventional composite magnetic head, and FIG. 5 is an enlarged view of the magnetic tape contacting surface of an example of the magnetic head according to the present invention, and FIGS.
The figure is an enlarged view of the magnetic tape contact surface of the magnetic head on the other side, FIGS. 8 to 13 are explanatory diagrams of each step in an example of the manufacturing process of the magnetic head of the present invention, and FIG. 1st
3 is a perspective view of a magnetic head manufactured by the steps shown in FIG. 3;
FIG. 15 is an enlarged plan view showing the tape contacting surface of the magnetic head, FIGS. 16 to 21 are explanatory diagrams of each step on the other side of the manufacturing process of the magnetic head of the present invention, and FIG. 22 23 is a perspective view of the magnetic head manufactured by the steps shown in FIGS. 16 to 21, and FIG. 23 is an enlarged plan view showing the tape contact n1yt of the magnetic head. In the figure (Ilm) (llb), (21m) (21b), (
31m) (31b), (41A) (41B), (51A
) (51B) is a magnetic core half-closed, (12m) (12b). (22m) (22b), (32m) (32b)
, (42A) (42B), (52A) (52B)
is a ferromagnetic metal thin film, (a), +23. C(I, ←1,1
51 is oxide glass, and g is a magnetic gap. , Busy・) Agent Sada Ito"'::,;,j+ Same as Hidemori Matsukuma j'1"j1! ; , I+ Figure 4 Figure 5 Figure 6 Figure 7 Procedural amendment July 23, 1982 1. Case description 1982 Patent Application No. 51648 2. Title of invention: Magnetic spatula. 3. Relationship with the case of the person making the amendment Patent applicant address: 6-7-35, Kitashinyo, Tokyo Parts Co., Ltd. Name (21
8) Sony Corporation Representative Director Norio Ohga 4, Agent 1-8-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo (
Shinjuku Building) Tokyo (03) 343-5821 (Representative)
(3388) Patent attorney Tei Ito 5, date of amendment order Showa year, month, day (1) In the specification, page 1, line 20 [Residual magnetic flux density BrJ is corrected to read ``Coercive force Hc J.'' (22 Same, page 3, line 19, "Farite J" is corrected to "ferrite." (3) Page 7, line 16, "ring element" is corrected to "reduction." (4) Same. , page 8, line lt, "film thickness" is corrected to "thick film." (5) Page 12, line 6, "does not occur at all," is corrected to "the phenomenon decreases." (6) Same, page 13, line 5, ``narrow'' is corrected to ``wide.'' (7) Page 13, lines 9 to 10, ``nearby'' is replaced with ``.'' (8) Same, 14j, line 12, "Metalloid system", correct it to "Metalloid system". (9) Same, 15j, Line 4, rBagOsJ toalwo r
Corrected as Ta2U3 J. Ql Same, 183fj, line 9, 1 after “obtained.”
In this example, after the magnetic product formation g, a volume iI fermentation was formed. The order may be reversed as in the previous example. Further, the previous example may also be in the same order as this example. ” to join. that's all

Claims (1)

[Claims] In a magnetic head, a thin ferromagnetic metal film is formed by vacuum thin film formation technology on the joint surface of a pair of magnetic cores made of ferromagnetic oxide, and a magnetic gap is formed by butting the pair of magnetic cores. A magnetic head characterized in that the ferromagnetic oxide and the ferromagnetic metal thin film are arranged on opposing surfaces with an oxide glass interposed therebetween.