JPS6374104A - Composite type magnetic head and its production - Google Patents

Abstract

PURPOSE:To improve wear resistance by butting and joining magnetic core half bodies formed by grasping both faces of magnetic metallic films with nonmagnetic materials and magnetic oxide materials and providing a groove for controlling track width near the magnetic gap part. CONSTITUTION:The magnetic core half bodies 41, 42 are formed by laminating the magnetic metallic films 47, 48 and magnetic oxide films 49, 50 on nonmagnetic material substrates 45, 46 consisting of crystallized glass or ceramics. The half bodies 41, 42 are joined at butt surfaces 41a, 42a via a thin film gap material in such a manner that the substrates 45, 46 and the films 49, 50 face each other to form the magnetic core body 40. The groove 52 for controlling the track width is provided near the magnetic gap 44 part of the films 49, 50 and molding glass 53 is melted and packed therein, by which the half bodies are joined and united and a core block 40 is obtd. Uneven wear is prevented by selecting the material for the substrates, by which the water resistance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic recording/reproducing device, and in particular to a composite magnetic head suitable as a magnetic head for high-density recording such as a video tape recorder, and a method for manufacturing the same.

(Conventional examples and their problems) Recently, in order to achieve higher performance and ultra-miniaturization in magnetic recording and reproducing devices, metal tapes with high coercive force that enable high-density recording on magnetic tape recording media have been widely used. However, on the other hand, research and development is progressing on magnetic heads that can sufficiently record on magnetic tapes having such high coercive force.

In such magnetic heads, so-called composite magnetic heads have been realized in which a magnetic core body is made by combining a metallic magnetic material with a high saturation magnetic flux density and a ferrite magnetic material with excellent high frequency characteristics.

FIG. 15 shows a magnetic core body 10 of a conventional composite magnetic head.
FIG. In the figure, 11.12 is a magnetic core half body, and both sides of a thin plate 13.14 made of a metallic magnetic material such as Sendust (registered trademark), amorphous, permalloy, etc. are made of, for example, Mn-7n ferrite, N+-, Zn ferrite, etc. The oxide-based magnetic materials 15, 16 and 17, 18 are respectively sandwiched and joined together, and at least one of the opposing abutting surfaces 11a and 12a, for example, the abutting surface 11a side as shown in the figure. A winding window 19 is formed in the winding window 19, and the pair of magnetic core halves 11 and 12 are abutted and joined together through a gap material such as SiO2 to form a magnetic gap 20. 22 and 23 are track width regulating grooves for regulating the width of the magnetic gap 20 on the tape sliding surface 21 to a predetermined track width, and are formed on both sides of the magnetic gap 20, respectively.
Molded glass 24,25 is melted and filled inside.

However, the thermal expansion coefficients of oxide-based magnetic materials and metal-based magnetic materials are significantly different, and when a metal-based magnetic film is formed on a flat surface of an oxide-based magnetic material, this metal-based magnetic film is very likely to peel off. Therefore, in the composite magnetic head 10, a thin plate 1 made of a metallic magnetic material wrapped in advance to a track width thickness is used.
3.14 is used, but not only is it very troublesome to wrap the metallic magnetic material to the thickness of the track width, but this thin plate 13.14 is extremely brittle and easily broken.
In particular, as the track width becomes narrower, the thickness of the thin plates 13 and 14 becomes thinner and this tendency becomes greater, which significantly impedes productivity. Furthermore, since the track width regulating grooves 22 and 23 are formed on both sides of the magnetic gap 20, the accuracy of the track width is not very good, and if the plate accidentally comes into contact with the thin plate 13 or 14 during grooving. , there was a risk that the thin plates 13 and 14 in the same area would fly off, resulting in poor productivity.

For this reason, although not shown in the drawings, a composite material having an X-shaped or inclined metal-based magnetic film on the abutting part of a pair of magnetic core halves made of oxide-based magnetic members, and melt-filled with molded glass on both sides of the magnetic gap part. Some type magnetic heads have been provided, but all of these have a V groove formed in a block made of an oxide magnetic material, and a metal magnetic film is formed in the V groove. ■There were problems such as the groove machining work was very troublesome and it was difficult to mass-produce.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and both surfaces of a metal-based magnetic film are made of a non-magnetic material made of crystallized glass or ceramic and an oxide-based magnetic material. A pair of magnetic core halves sandwiched by are butt-joined so that the non-magnetic materials and the oxide-based magnetic materials face each other, and
The present invention provides a composite magnetic head comprising a magnetic core body having a track width regulating groove in the vicinity of the magnetic gap of the oxide-based magnetic material, and a method for manufacturing the same.

(Embodiment) FIG. 1 is a perspective view of a magnetic core body 40 which is a first embodiment of a composite magnetic head according to the present invention, and FIG.
2 is a partially enlarged front view of the tape sliding surface near the magnetic gap of the magnetic core body 40 shown in the figure, and will be described below with reference to FIGS. 1 and 2. FIG.

In the figure, 41 and 42 are abutting surfaces 41a.

42a, and these pair of magnetic core halves have, for example, a 5.
Butted through a gap material made of a thin film such as iOz,
A magnetic core body 40 having a magnetic gap 44 on the tape sliding surface 43 is configured.

The magnetic core halves 41 and 42 are formed by sputtering or otherwise forming a thin film of a gold-based magnetic material [147 and 48] made of sendust or amorphous on a highly wear-resistant non-magnetic material 45, 46 made of crystallized glass or ceramic. 49.50 of an oxide-based magnetic material such as 1Vln-7n ferrite is bonded thereon.

A winding window 51 is formed on the abutting surface 41a of one of the magnetic core halves 41, and a coil (not shown) is wound using this winding window 51.

Reference numeral 52 denotes a track width regulating groove, which is formed near the magnetic gap 44 on the oxide-based magnetic material 49.50 side.

A molded glass 53 is melted and filled into the track width regulating groove 52, and forms a part of the tape sliding surface 43.

As is clear from the above structure, in the magnetic core body 40 according to the present invention, the gold scrap magnetic films 47 and 48 are coated with a non-magnetic material 45, 46 such as crystallized glass or ceramic, and an oxide-based magnetic material 49. 50, but since the wear characteristics of the non-magnetic substrate 45 and 46 are close to those of the oxide-based magnetic material 49.50, it is possible to easily select a composite magnetic substrate with less uneven wear. head is possible.

FIG. 3 is a perspective view showing a magnetic core body 60 which is a second embodiment of the composite magnetic head according to the present invention. Only the points that are different from the magnetic core body 40 will be explained.

In FIG. 3, the difference from the magnetic core body 40 in FIG. Its axis of easy magnetization is 65.66
This point is configured to be inclined toward the magnetic gap 44.

With the above configuration, it is possible to make a composite magnetic head with even better magnetic properties due to effects such as being able to make the magnetic flux flow more easily in the direction of the magnetic gap during recording.

Next, a method for manufacturing the magnetic core body 40 according to the present invention shown in FIG. 1 will be explained.

4 to 12 are schematic explanatory diagrams of main steps for explaining an embodiment of the method for manufacturing the magnetic core body 40, which is the first embodiment shown in FIG. 1.

The first step is as shown below. As shown in FIG. 4(a), a plurality of nonmagnetic substrates 70 made of crystallized glass or ceramic are prepared, and as shown in FIG. The same figure (C) is obtained after mirror polishing both surfaces 70a and 70b of the substrate 70.

As shown in (d), a metal-based magnetic film 71 such as sendust is formed on both surfaces 70a and 70b of the non-magnetic substrate 70 by a vacuum thin film forming means such as sputtering, vapor deposition, and ion blasting. At this time, metal magnetism! 171
G; tAf203, Si02.

It may also be formed via an insulating film such as Ta 20s.

The second step is as shown below, and as shown in FIG. b
), both surfaces 72a, 7 of the oxide-based magnetic substrate 72
Mirror polish 2b.

The third step is as shown below, and as shown in FIG. 6, a plurality of nonmagnetic substrates 70 obtained in FIG. 4(d) and a plurality of oxidized substrates obtained in FIG. 5(b) are A first laminated block 73 is obtained by sequentially laminating a physical magnetic substrate 72 via a bonding glass.

The fourth step is as shown below, and as shown in FIG. 7, the first laminated block 73 obtained in the third step is cut to approximately the height h of the magnetic core body 40, After obtaining the second laminated block 74 by polishing, the eighth
As shown in the figure, a pair of core block halves 77 are obtained by cutting the cut surface 75 along the cut 11176. At this time, this cutting line 76 can be made to have an azimuth angle of θ with respect to the normal line 78 of the laminated surface, if necessary. Further, the cross section of the core block half body 77, which will be a later-described abutment surface, is finished by polishing.

The fifth step is as shown below, and as shown in FIG. 9, a pair of core block halves 77 obtained in the fourth step are
The opposing cut surfaces of a and 77b are brought into contact with the butt surfaces 79 and 80.
Metal-based magnetism within this butt plane! After forming a group of track width regulating grooves 81 along the bonding surface of the oxide magnetic material 72 adjacent to the oxide magnetic material 72 using a cutting means such as a blade, as shown in FIG. Groove 81 is filled with molded glass 82, and abutting surfaces 79 and 80 with excess molded glass are removed by polishing.

The sixth step is as shown below, and as shown in FIG.
A winding groove 83 is formed on the abutting surface 80 of the core block halves 77a and 77b, and an adhesive groove 84 is formed as necessary on the rear end of the abutting surfaces 79 and 80 of the core block halves 77a and 77b.
A winding guide groove 85 is formed on the back surface of the abutting surfaces 79 and 80.

The seventh step is as shown below, and as shown in FIG. 11, the core block half 77 obtained in the sixth step is
a, 77b between the abutting surfaces 79 and 80, for example, SiO
The oxide-based magnetic material 72.
The comrades 72 and the non-magnetic materials 70 and 70 are butted so as to face each other, and a part of the winding groove 83 and the adhesive groove 84 are melted and filled with adhesive glass 86 to be joined and integrated to obtain a core block 87. .

The eighth step is as shown below, and as shown in FIG. 11, the core block 87 obtained in the seventh step is cut along a predetermined cutting line 88. A magnetic core body 89 shown before tip polishing is obtained. At this time,
The cutting line needs to pass through at least the molded glass 82 filled in the track regulating groove 81.

Thereafter, by subjecting the magnetic core body 89 to a predetermined tip polishing, the magnetic core body 40 shown in FIG. 1 can be obtained.

As described above, according to the manufacturing method of the present invention, metal-based magnetic l
1171 is bonded onto a non-magnetic substrate 7o made of crystallized glass or ceramic, and these crystallized glass or ceramics are selected from a wide range of materials having almost the same coefficient of thermal expansion as the metal-based magnetic film 71. This makes it possible to prevent peeling phenomena caused by differences in thermal expansion coefficients and to achieve strong bonding.

In addition, the track width regulating groove 81 only needs to be processed on the oxide-based magnetic material 72 side, which halves the groove processing process and doubles the accuracy of the track width obtained by groove processing. Even if the blade were to come into contact with the metallic magnetic film 71, there is no risk of it breaking because the metallic magnetic film 171 is firmly bonded to the non-magnetic plate 7o, resulting in improved machining accuracy, improved yield and accuracy. This can be expected to have a great effect on improving the quality of life.

Next, a method of manufacturing the magnetic core body 60 according to the second embodiment of the present invention shown in FIG. 3 will be explained.
Since this method is substantially the same as the manufacturing method of the magnetic core body 40 according to the embodiment, the same components are denoted by the same reference numerals, and the explanation thereof will be omitted, and only the points that are different from the manufacturing process described above will be explained.

First, as the oxide-based magnetic substrate 72 in the second step, a single-crystal ferrite material having an easy axis of magnetization, such as Mn--Zn single-crystal ferrite, is used, for example. In the step of obtaining the first laminated block 73 in the third step, as shown in FIG.
The sheets are stacked so as to be inclined toward one side surface 91.

Next, the abutment surfaces 79.80 (9th factor) in the step of machining the track width regulating grooves of the pair of adjacent core block halves 77a and 77b in the fifth step are shown in FIG. 14 in the second embodiment. As shown above, the surfaces where the easy magnetization axes 90 are inclined in the same direction are used as abutment surfaces 79.80'', and track width regulating groove groups 81.81' are formed in the same manner as described above, and after filling molded glass (not shown), the core block half is formed. The body 77b is reversed so that the oxide-based magnetic material and the non-magnetic material face each other as in the first embodiment.
By using the eighth step as is, the magnetic core body 60 of the second embodiment shown in FIG. 3 can be easily obtained.

(Effects of the Invention) (1) As described above, the magnetic core body of the present invention consists of a pair of metal-based magnetic films sandwiched on both sides by a non-magnetic material made of crystallized glass or ceramic and an oxide-based magnetic material. The magnetic core halves are butt-jointed so that the non-magnetic material and the oxide-based magnetic material face each other, and the magnetic core has a track width regulating groove in the vicinity of the magnetic gap of the oxide-based magnetic material. Because the structure consists of a main body, a composite magnetic head with less occurrence of uneven wear is possible.Also, as in the second embodiment, single crystal ferrite is used, and its axis of easy magnetization is tilted toward the magnetic gap. With this structure, a composite magnetic head with even better magnetic properties can be achieved.

(21 Furthermore, according to the manufacturing method of the present invention, the metal-based magnetic film is formed by vacuum thin film forming means on crystallized glass or ceramic having almost the same coefficient of thermal expansion as the metal-based magnetic film. As a result, peeling phenomenon due to differences in thermal expansion coefficients does not occur, and the track width regulating grooves only need to be placed on the oxide-based magnetic material side, making the groove machining process half the conventional process. The precision of the track widths produced is doubled, and there is no fear that the metallic magnetic film will be destroyed during groove machining, which can be expected to have a great effect on improving the groove machining accuracy, yield, and mass productivity. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic core body which is a first practical example of a composite magnetic head according to the present invention, and FIG. 2 is a perspective view of a tape rI near the magnetic gap of the magnetic core body 40 shown in FIG.
FIG. 3 is a partially enlarged front view of the U moving surface, and FIG. 3 is a perspective view showing the magnetic core body of the second embodiment of the composite magnetic head according to the present invention. The fourth to twelfth factors are shown in FIG. 13 and 14 are schematic explanatory diagrams of the main steps for explaining one embodiment of the method for manufacturing the magnetic core body, which is the first embodiment.
15 is a schematic explanatory diagram of the main steps for explaining another embodiment of the manufacturing method of the magnetic core body which is the second embodiment of the composite magnetic head according to the present invention shown in FIG. FIG. 3 is a perspective view showing the magnetic core body of the head. 40.60.89...Magnetic core body, 41,42゜6
1.62...Magnetic core half, 41a, 42a, 63a
. 64a, 79, 80.80--butt surface, 43
...Tape calendar surface, 44...Magnetic gap, 45,
46゜70... Non-magnetic material (substrate) made of crystallized glass or ceramic, 47.48.71... Metal-based magnetic film, 49.50.63.64.72... Oxide-based magnetic material (board), 51...winding window, 52.81.81"
...Track width regulating groove, 53.82...Mold glass, 65.66.90...Easy magnetization axis, 73...
- Laminated block, 77.77a, 77b... Core block half, 83... Winding groove, 87... Core block. Figure 3 (^) t4J Figure 11 Figure 15

Claims (4)

[Claims] (1) A pair of magnetic core halves formed by sandwiching both sides of a metal-based magnetic film between a non-magnetic material made of crystallized glass or ceramic and an oxide-based magnetic material, 1. A composite magnetic head comprising a magnetic core main body which is butt-joined so that the materials face each other and has a track width regulating groove in the vicinity of the magnetic gap of the oxide-based magnetic material. (2) The composite magnetic material according to claim 1, wherein the oxide-based magnetic material is made of single-crystal ferrite, and the direction of the axis of easy magnetization thereof is inclined toward the magnetic gap portion. head. (3) A) Step of forming a metal-based magnetic film on a non-magnetic substrate made of crystallized glass or ceramic, and alternately laminating this non-magnetic substrate and an oxide-based magnetic substrate to obtain a laminated block; b) This step. A step of cutting the laminated block into predetermined dimensions to obtain a pair of core block halves; c) A track width is added to the oxide-based magnetic material on the abutting surfaces of the pair of core block halves adjacent to the metal-based magnetic film. forming a regulating groove and filling the groove with molded glass; d) forming a winding groove on the abutting surface of at least one of the pair of core block halves whose track width regulating grooves are filled with molded glass; After forming the core block, the pair of core block halves are butted and joined together with the oxide-based magnetic material and the non-magnetic material facing each other via a gap material to obtain a core block; A method for manufacturing a composite magnetic head, comprising: a step of cutting a block to obtain a magnetic core body; (4) A) A metal-based magnetic film is formed on a non-magnetic substrate made of crystallized glass or ceramic, and this non-magnetic substrate and a single-crystal ferrite substrate whose axis of easy magnetization is inclined in a plane are laminated alternately. (b) cutting this laminated block into predetermined dimensions to obtain a pair of core block halves; c) magnetizing the abutting surfaces of the pair of core block halves to the single crystal ferrite. Select surfaces with easy axes facing in the same direction,
forming a track width regulating groove adjacent to the metal magnetic film in the single crystal ferrite on the abutting surface, and filling the groove with molded glass; d) filling the track width regulating groove with molded glass; After forming a winding groove on the abutting surface of at least one of the pair of core block halves, one core block half is aligned so that the axis of easy magnetization of the single crystal ferrite in both core block halves faces toward the magnetic gap. a step of inverting the body and joining the single crystal ferrite and non-magnetic materials facing each other through a gap material to obtain a core block; e) cutting this core block to obtain a magnetic core body; A method for manufacturing a composite magnetic head, characterized in that it is manufactured by: