JPS61239408A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To obtain a magnetic head which can use satisfactorily a magnetic tape having high reluctance force by securing such a structure where a metallic magnetic substance of high saturated magnetic flux density is held between oxide magnetic substances having high permeability. CONSTITUTION:The glass 3 having a high melting point as well as high wear resistance is filled into a groove 2 of a plate 1 made of a ferrite magnetic material. Then a glass film 4 is produced by sputtering the glass of the same quality as the glass 3. The SiO2, etc. having affinity with the film 4 with a high melting point is sputtered on both sides of a thin metallic magnetic substance 5 for formation of a nonmagnetic thin film 6. Then these plates 1 and substances 5 are laminated alternately and pressed with heating to obtain a monolithic lamination layer substance 7. This substance 7 is cut into core half blocks 8. A quartz glass film 12 is sputtered on the surface between grooves 9 and 11. While a glass layer 13 of a low melting point is formed between grooves 10 and 11 and also on the edge side surface of the groove 10. Then blocks 8 are butted with each other and the glass rods having a lower working point than the glass 3 and a heat expansion coefficient approximately equal to that of the plate 1 are put into both grooves 9 and 10 and then pressed with heating. Thus a composite magnetic head block 15 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head suitable for recording and reproducing high frequency signals, for example, and a method for manufacturing the same.

[Prior art and its problems]

For example, in order to improve the performance and miniaturize video tape recorders, it is necessary to use magnetic tape with high coercive force. Since magnetization is difficult, a strong signal magnetic field must be applied from a magnetic head to sufficiently magnetize this type of magnetic tape.

However, since a strong signal magnetic field is applied, even if a large signal current is passed through the windings of the magnetic head to increase the magnetomotive force, it will not affect the recording medium of the magnetic herad core that constitutes the magnetic path inside the magnetic head. The contact area becomes magnetically saturated,
It may not be possible to extract a sufficiently strong signal magnetic field. In other words, in a magnetic head constructed using an oxide-based magnetic material, the saturation magnetic flux density of the core is only about 4,000 to 5,000 Gauss, so if the recording current is increased to magnetize a magnetic tape with high coercive force, the head The chip becomes saturated, the distribution of the recording magnetic field widens, and recording becomes impossible.

Therefore, it has been proposed to use a metallic magnetic material with a high saturation magnetic flux density as the magnetic material of the magnetic head, rather than an oxide-based magnetic material such as Mn-Zn ferrite. It is said that magnetic heads made of metal magnetic materials can sufficiently handle high coercive force magnetic tapes, since the amount is about twice that of physical magnetic materials.

However, metal magnetic materials have drawbacks such as low resistivity, low magnetic permeability in the video band, and poor wear resistance, and furthermore, they are difficult to process compared to Mn--Zn ferrite and the like.

[Means for solving problems]

The core of the magnetic head is integrally bonded with a highly wear-resistant non-magnetic material on the front side of the metal magnetic material and an oxide-based magnetic material on the back side of the metal magnetic material using high melting point non-magnetic materials. The magnetic head gap is made of a low melting point non-magnetic material.

In addition, in order to manufacture the magnetic head as described above, there is a step of forming grooves in the oxide-based magnetic material, and a material having a high melting point and a thermal expansion coefficient that is approximately the same as that of the oxide-based magnetic material is added to the grooves. A step of filling a non-magnetic material with high wear resistance, a step of forming a high melting point non-magnetic film having good affinity with the non-magnetic material on the metal magnetic material, and a step of filling the oxide-based magnetic material filled with the non-magnetic material. The body and the metal magnetic body on which the non-magnetic film is formed are laminated and integrated, and -i
a step of forming a joining groove in the magnetic head core half block, a magnetic head core half block with the groove formed therein, and a corresponding magnetic head core half block; and slicing the magnetic head composite block to form a predetermined shape. A manufacturing method including a process is provided.

〔Example〕

FIGS. 1A to 1J are explanatory diagrams of an embodiment of a magnetic head and a method of manufacturing the same according to the present invention.

First, as shown in FIG. 1A, a square or rectangular plate 1 of ferrite magnetic material is prepared, and grooves 2 having a depth H1 and a width W are formed on both sides of the plate 1.

Next, as shown in the figure, a glass 3 having a high melting point and having substantially the same coefficient of thermal expansion as the ferrite magnetic material and excellent wear resistance is filled.

Then, as shown in FIG. A glass film 4 having a thickness of approximately several micrometers is formed by sputtering a glass having approximately the same coefficient of thermal expansion and a high melting point.゛The coefficient of thermal expansion of the glass 3 and the glass film 4 is approximately 12.
．． 6 x 10'' to l4.9 x 10-+6, and the working point is approximately 550 to 670°C.

In addition, as shown in FIG.
A high melting point material having good affinity with the glass film 4, such as 5iOy or ALxO*, is sputtered onto both sides of the metal magnetic material 5 which has been made into a thin ribbon (25 μm) to form a thin strip of about 0.1 to 0.
．． A nonmagnetic thin film 6 with a thickness of 2 μm is formed.

Then, what was obtained in the steps up to the above, that is, Figure 1 a
A plurality of plate bodies 1 obtained through the step -c and a plurality of metal magnetic bodies 5 obtained in FIG. The laminates are integrated to obtain an integrated laminate 7.

Thereafter, the integrated laminated body 7 is cut along the part indicated by the dashed-dotted line in the same figure e, and this cut piece is cut at an azimuth angle Ei as shown by the two-dot chain line in the figure e, and a pair of magnetic A head core half block 8 is obtained, and grooves 9 and 10 for joining and grooves 11 for winding windows are formed in this magnetic head core half block 8.
to form.

Further, a bonding groove is similarly formed in the other magnetic head core half block forming the pair.

After these processes, a mirror polishing process is performed to form the groove 9.
A quartz glass film 12 with a thickness half the gear width is formed on the surface between the grooves 10 and 11 by sputtering.
A low melting point glass layer 13 is formed between the groove 10 and the end surface of the groove 10 (FIG. 1f).

Then, the pair of bare magnetic head core half blocks 8 produced through the above steps are butted together as shown in g in the same figure, and the grooves 9 and 10 are placed at a working point lower than the working point of the glass 3 and a plate A glass rod with a thermal expansion coefficient substantially the same as that of the body 1 is inserted, and the temperature near the working point of this glass rod is heated to, for example, 450 to 600°C, and pressure is applied.
The magnetic helad core half-flocks 8 are joined together with the molten glass 14 of the glass rod to obtain a magnetic head composite block 15 as shown in the figure.

Next, the slice is cut so that the cut surface covers the plane shown by the imaginary line in the first drawing, that is, the part of the glass 3 filled in the groove 2 of the plate 1, and a magnetic head as shown in FIG. An element body 16 is produced, and polished so that the position of the imaginary line extending over the glass 3 in the figure becomes the tape sliding contact surface, that is, the gap depth becomes t, and the winding 17 is applied. As a result, a magnetic head 18 according to the present invention as shown in FIG. 1j is obtained.

The magnetic head obtained as described above has a structure in which a metal magnetic material with high saturation magnetic flux density is sandwiched between oxide-based magnetic materials with high magnetic permeability, so it is fully compatible with magnetic tapes with high coercive force. It is possible.

Furthermore, since there is a non-magnetic material with high abrasion resistance on the tape sliding surface side, the tape has high durability.

Further, the bonding force between the metal magnetic material, the non-magnetic material and the oxide-based magnetic material is large, and the material is durable and highly reliable.

In particular, since glass with a low working point is used to form the gap, the high melting point glass that joins the metal magnetic material and the oxide magnetic material does not melt when the gap is formed.
Therefore, there is no possibility that the metal magnetic material and the oxide magnetic material will separate, and the manufacturing efficiency can be improved.

〔effect〕

It is highly wear-resistant and durable, and can be used with high coercive force magnetic tapes, and such high-performance and highly reliable magnetic heads can be manufactured at a high manufacturing yield.

[Brief explanation of drawings]

FIGS. 1A to 1J are explanatory diagrams of an embodiment of a magnetic head and a method of manufacturing the same according to the present invention. 1... Ferrite magnetic material plate, 2... Groove, 3...
Glass, 4...Glass film, 5...Metal magnetic material, 6.
...Nonmagnetic thin film, 7...Laminated integrated product, 8...Magnetic head core half block, 9.10...Groove, 11...
groove, 12... quartz glass film, 13... glass layer, 1
5...Magnetic head composite block, 18 magnetic heads. Patent applicant: Japan Victor Co., Ltd. Representative: Katsumi Utaka 2-0'
Nof 1st '1''' 1 Figure

Claims (2)

[Claims] (1) The core of the magnetic head is made of a high melting point non-magnetic material, with a highly wear-resistant non-magnetic material on the front side of the side surface of the metal magnetic material, and an oxide-based magnetic material on the back side of the side surface of the metal magnetic material. 1. A magnetic head characterized in that the gap of the magnetic head is made of a low melting point non-magnetic material. (2) Forming a groove in the oxide-based magnetic material, and filling the groove with a highly wear-resistant non-magnetic material having a high melting point and a coefficient of thermal expansion that is approximately the same as that of the oxide-based magnetic material. a step of forming a high melting point nonmagnetic film having good affinity with the nonmagnetic material on a metallic magnetic material; and a step of forming an oxide-based magnetic material filled with the nonmagnetic material and a metal on which the nonmagnetic film is formed. a step of laminating and integrating a magnetic body to form a pair of magnetic head core half blocks, a step of forming a bonding groove in the magnetic head core half block, and a step of forming a magnetic head core half block with the groove formed therein. a step of abutting the corresponding magnetic head core half blocks, disposing a low melting point non-magnetic material in the groove, and joining and integrating the magnetic head core half blocks to form a magnetic head composite block; 1. A method for manufacturing a magnetic head, comprising: slicing and forming into a predetermined shape.