JPS62266708A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve recording and reproducing efficiency by constituting a winding coil in the form of bringing the same in tight contact with a thin film magnetic metallic material core. CONSTITUTION:Approximately ring head shaped grooves 22 for forming a central core are provided to the surface of core half bodies 21a, 21b consisting of a nonmagnetic material such as glass or ceramics and a magnetic metallic material 23 consisting of 'permally(R)', 'Sendust(R)', etc., and an insulator 24 consisting of SiO2, ZrO2, etc., are alternately laminated by means such as sputtering into the grooves 22 to form a track width Tw. The winding coil 25 is embedded to the bottom surface of the central core formed by alternately laminating the magnetic matellic material 23 and the insulator 24. A thin film coil 26 is formed atop the same and the coils are connected in the respective prescribed positions, by which the coil for in and out of signals is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a magnetic head used in a magnetic recording/reproducing device or the like.

(Prior art) With the development of magnetic recording technology in recent years, magnetic heads used in magnetic recording and reproducing devices such as video tape recorders include
It is required to be able to record on and read from a magnetic tape with high magnetic flux toleration and high coercive force, and to be able to easily form narrow tracks in order to improve the in-plane recording density of the magnetic tape.

The above requirements can be met by using gold, a chlorinated magnetic material with a high saturation magnetic flux density, such as amorphous, sendust, permalloy, etc., in place of the conventional ferrite. Furthermore, processing methods using vacuum thin film forming techniques such as sputtering, vapor deposition, and ion blating are suitable for the requirement of contact. In order to satisfy these demands, various proposals have been made regarding magnetic heads formed with ferromagnetic metal thin films. For example, as shown in FIG.
Core halves 4a are separated and laminated by an insulating film 2 made of non-magnetic oxide by a pair of holders.

There is one with 4b sandwiched between them. and these core halves 4
A winding groove 5 is formed in at least one of the core halves of a and 4b, and a coil 6 is wound in this winding groove 5, and the gap Q and track width are determined by butt of the core halves 4a and 4b. Tw is formed. This proposal was published in Japanese Unexamined Patent Publication No. 6
It is known from the publication No. 0-217508.

Further, a proposal as shown in FIG. 18 disclosed in Japanese Patent Application Laid-Open No. 103511/1983 is also known. In the figure, single-crystal or polycrystalline ferrite core halves i1a, i
A winding groove 15 is formed in at least one of the core halves of ib, the gap abutting surfaces of the core halves 11a and llb are mirror polished, and a metal magnetic material 12 is applied to the surface to a skin depth suitable for the operating frequency. It is formed by means such as sputtering to a film thickness of . A track width TW and a gap Q are formed. Roughly, an oxide film represented by 5in2 or A12o3 is formed as a gap protective film on the front gap abutting surface to a thickness corresponding to the required gap of 0 by sputtering or vapor deposition, and then the core halves 11a and 11b are bonded together. The head core 11 is formed by butting and joining the two cords using an arithmetic adhesive or a non-technical adhesive such as glass. A tape sliding surface is roughly formed to have the required radius of curvature, and a coil 16 is wound around it to complete the magnetic head.

However, in the magnetic head shown in FIG. 17, the laminated interface between the metal magnetic material 3, the insulating film 2, and the holder 1 is bonded with an organic adhesive or an inorganic adhesive; Since bonding with a magnetic material is inherently difficult, there is a problem in that peeling is likely to occur. Furthermore, in both the magnetic heads shown in FIGS. 17 and 18, sufficient strength cannot be obtained when the metal magnetic materials 3 or 12 are bonded together, especially when bonded using an inorganic adhesive. Furthermore, in the case of the magnetic head shown in FIG. 17, since the holder 1 made of non-magnetic material has a thickness of 50 μm or more, the coil 6 cannot be tightly wound around the surface of the magnetic core, resulting in poor recording and reproducing efficiency. There was also a problem.

(Problems to be Solved by the Invention) The present invention solves the problem of conventional magnetic heads in which the bonding strength between the metal magnetic material, the insulating film, and the holder is weak and easily peels off, and The purpose of the present invention is to solve the problem of poor recording and reproducing efficiency due to the winding of a coil, and to provide an inexpensive magnetic head that has good recording and reproducing efficiency, is mass-producible, and highly reliable.

[Configuration 1 of the Invention (Method for Solving Problems V) In order to achieve the above object quickly, the present invention forms a substantially ring-shaped groove in a substrate made of a non-magnetic material, and injects a metal magnetic material into this groove. A magnetic head is constructed by embedding a central core made of the following, and forming a thin film of a coil having a balanced winding structure around the central core via an insulator.

(Function) According to the above configuration, since the central core is embedded in the substrate made of a non-magnetic material, a bonding surface is directly formed between the substrates, and the bonding strength is improved. Both the center core and the coil are formed using thin film technology, and because the coil tightly sandwiches the core, the recording signal in the coil efficiently excites the core, and changes in magnetic flux from the magnetic tape efficiently reach the coil. Second Embodiment Transmitted as Electromotive Force An embodiment of the magnetic head according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Core halves 21a, 21 made of non-magnetic material such as glass or ceramic
A substantially ring-head shaped groove 22 for forming a central core is provided on the surface of b.

In this groove 22, a metal magnetic material 23 made of permalloy, sendust, etc. and an insulator 24 made of 5i02, ZrO2, etc. are alternately laminated by means such as sputtering to form a trunk width Tw. A winding coil 25 is embedded in the lower surface of the central core made of alternately laminated gold RFEk material 23 and an insulator 24, and a thin film coil 26 is formed in the upper surface, each at a predetermined position. are connected to form a signal input/output coil. Note that the thickness δ of the metal magnetic material 23 within the skin depth is formed as shown in the following equation (1).

δ= (7Tr7- (1) where f is the operating frequency, μ is the magnetic permeability of the metal magnetic material (thin film), and p is the specific resistance of the metal magnetic material (thin film).

The joint surfaces of the core halves 21a and 21b are mirror-polished, and the joint surfaces are coated with 5in2° ZrO2,
An oxide such as A1203 is sandwiched and butted, and bonded with an organic adhesive, an inorganic adhesive, a glass material, or the like to form a gap Q. A holder 27 made of a non-magnetic material is coated on the surface of the core half-holes 21a and 21b on the side where the central core is formed, and the holder 27 is bonded from the side with an organic adhesive, an inorganic adhesive, a glass material, etc. The dynamic surface 28 is formed into a curved surface with a predetermined curvature.

2 to 16 show the means for manufacturing the magnetic head of this embodiment. In Figure 2, t finished to the specified dimensions
A groove 32 for a coil with a pitch Pd and a depth d is formed in a non-magnetic material block 31 made of e1 by machining using a peripheral grindstone, a wire saw, a band saw, etc. to 1/2 of the desired number of windings.
Form the number of grooves.

If the desired number of windings is an odd number, one extra turn is added and a groove is formed. At this time, the block 31 is made of glass, in order to improve the abrasion resistance caused by the magnetic tape when the head is completed.
Hard materials such as crystal glass and ceramics are used as materials. Next, as shown in FIG. 3, a conductor 33 made of copper, aluminum, or the like is formed in the coil groove 32 by sputtering, vapor deposition, plating, or the like. Then, as shown in FIG. 4, a ring head-shaped groove 34 is formed by milling with a diamond cutting tool or the like. The relationship between the depth h of this groove 34, the depth d of the coil groove 32, and the track width TW is as shown in the following equation (2).

T ==, hzod, /l, 2~d7/4...
(2) Also, the dimension W of the opening on the side of the board and the board width C, l
The relationship with is shown in the following equation (3).

W□ =C, /1.2 ~CW /6...
3) Next, as shown in FIG.
An insulator 35a made of 2 or the like is formed to a thickness of 100 OA' or more, and a metal magnetic material 35b made of sendust or the like is roughly formed thereon by sputtering or the like to a thickness satisfying the above formula (1).

Then, roughly 8
A metal magnetic film 35d is laminated via an insulator 35G made of 102 or the like and having a thickness of several 10 A' to several 1000 A'. Further, the excess film on the top layer is ground by means such as grinding, lapping, polishing, etc., to form the central core 35 into a substantially ring head shape as shown in FIG.

Next, as shown in FIG. 7, an insulating film 36 made of SiO2 or the like is formed on the center core 35 to a thickness of 0.5 μm by sputtering or the like.
Form it to a thickness greater than or equal to that. Then, an insulating film opening 37 is formed at the position shown in FIG. 8 by dry etching, wet etching, etc., and the insulating film 936 on the lower conductor 33 is removed. At this time, the pitch Ph of the openings 37 and the pitch Pd of the lower coil grooves 32 are made equal. However, the openings 37 should not overlap.

In Figure 9, a conductor 3 made of copper, aluminum, etc.
8 is formed on the entire surface of the insulating film 36 by sputtering or the like to a thickness of 1 μm or more. Then, as shown in FIG. 10, the conductor 38 is patterned by means such as photoetching so as to connect the opposing insulating film openings 37, thereby forming a coil around the central core 35 together with the conductor 33. do. Next, as shown in FIG. 11, the center of the head core 31 is cut into parts using a grindstone or the like, and the core halves 3
1a and 31b are obtained. And these core half holidays 31a,
The three abutting surfaces of 31b are finished to a mirror finish by lapping and polishing, and 5ro2 is applied to the front gap part on the tape sliding surface side of one abutting surface 39 and the area near it.
゜Z r 02, A, j! A gap film made of 203 or the like is formed by sputtering or the like to have a thickness approximately equal to the gap length q. Then, as shown in FIG. 12, the core halves 31a and 31b are butted together and bonded with high melting point glass or the like to obtain a gap q. A conductor 40 roughly made of copper, aluminum, etc. is formed at a predetermined position, and the core half 31a,
311) Join the ends of the upper coil.

Then, a balanced winding coil is constructed. Then, a low melting point glass 41 is formed by sputtering, vapor deposition, etc. to a thickness equal to or greater than the step difference between the upper coil conductors 38 and 40. Next, as shown in FIG. 13, a holder 42 made of an insulating non-magnetic material is bonded with a low melting point glass 41. Finally, as shown in FIG. 14, the magnetic herad core 31 configured as described above is bonded to the Heas slope 43 using an organic adhesive or the like.
The tape sliding surface 45 is roughly finished to the required curvature, and the lead wire 44 is connected to the coil pattern 38 using a wire bonder or the like to complete the magnetic head.

According to the magnetic head shown in this embodiment, the conventional manual winding process is not necessary, and a highly reliable and inexpensive magnetic head can be obtained. Furthermore, since the wire-wound coil is configured in close contact with the thin film metal magnetic core, efficiency during recording and reproduction is sufficiently improved. Furthermore, as long as the non-magnetic substrate and holder match the coefficient of expansion with the metal magnetic material, a hard one can be selected, resulting in good wear resistance. In addition, since the core of metal magnetic material is surrounded by a non-magnetic substrate,
The strength of the head core is sufficiently increased, and a highly reliable and inexpensive magnetic head can be provided. By the way, when a magnetic tape slides against a magnetic head under a certain tension range, a brown spot-like pattern similar to a burn-in phenomenon may occur on the tape sliding surface of the head core, causing space loss. According to the present embodiment, it has been found through experiments by the inventors that because the holder as a non-magnetic substrate and the metal magnetic material core exist simultaneously in the sliding direction of the magnetic tape, the occurrence of the pattern described above is small. .

15 and 16 show the arrangement of the head cores 31 shown in FIG. 12 described above in multiple rows in the gap position direction, and the core halves 51a and 51b of the head core 51 are butted together to form a gear ring Ω. The rough upper coil patterns 53 and 54 and the low melting point glass 52 above them are each formed by sputtering or the like. Then, the holders 55 made of a non-magnetic material, which is an insulator, prepared in advance are joined at individual positions, and cut using a grindstone, wire saw, band saw, etc. at the position of line A-B shown in FIG. The head core 31 shown in FIG. With this configuration, it is possible to use multiple rows, so productivity can be greatly increased.

[Effects of the Invention] As described above, according to the present invention, since the wire-wound coil is configured in close contact with the thin film metal magnetic core, the recording and reproducing efficiency is improved, and a temperature-resistant, reliable and inexpensive device is obtained. A magnetic head can be provided.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the magnetic head according to the present invention, FIGS. 2 to 14 are views showing the steps for manufacturing the magnetic head shown in FIG. 1, and FIGS. FIGS. 17 and 18, which show other manufacturing steps of the invention, are perspective views showing a conventional magnetic head. 21a, 21b... Core half-open (substrate) 22... Groove 23... Metal magnetic material (center core) 24... MIi
Resting 2 bodies...Coil 32...Groove q...
Gap Agent Patent Attorney Nori Ken Chika Hiroshi Uji Figure 1 Figure 32 Figure 23-5 Figure 6 Figure 10 Figure Otsu 4 Figure 14 9 /'51b
'5]a Figure 16

Claims (3)

[Claims] (1) A substrate made of a non-magnetic material, a central core made of a metal magnetic material embedded in a substantially ring-shaped groove formed in this substrate, and a thin film formed around this central core via an insulator. A magnetic head comprising a coil having a balanced winding structure. (2) The magnetic head according to claim 1, wherein the lower coil formed on the surface where the center core abuts the substrate is provided in a groove formed in the substrate. (3) A magnetic head according to claim 1 or 2, wherein the substrate and the central core are each divided into two pieces and butt-joined with a gap therebetween.