JPS61229216A - Magnetic head core and its manufacture - Google Patents

Abstract

PURPOSE:To enhance the bonding strength of half cores by forming an active metallic thin film layer made of a specific metal to a contact face between a notched slot and a bonding glass material. CONSTITUTION:Notch slots 12 formed at a prescribed pitch restricting the magnetic gap and a bonding strengthening slot 13 cut in the lengthwise direction of a core block 10 are formed to a butt face 11 with a half core block 20 on the block 10. Further, notch slots 22 in matching with the said notch slots 12, a bonding strengthening slot 23 opposed to the said bonding strengthening slot 13 and a winding slot 24 in parallel with the slot 23 and crossing the notch slots 22 are formed to a butt face 21 of the half block 20 to the half core block 10. Then active metallic thin film layers 15, 25 are formed to the butt faces 11, 21 of the half core blocks 10, 20. The active metallic thin film layers 15, 25 are adhered to the surface of the butt faces 11, 21 by applying an active metal selected from Ti, Zr, Hf, Cr, Mo or W by means of plating, vapor- deposition or sputtering.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a magnetic head core with excellent bonding strength between a pair of half cores and a method for manufacturing the same.

"Prior art and its problems" Among magnetic heads, the type in which the magnetic gap width is regulated by notched grooves formed on the opposing surfaces of a pair of half cores uses a non-magnetic bonding material such as glass filled in the notched grooves. Mainly to obtain joint strength between both core blocks. However, the notch grooves are small, and in conventional products, the bonding properties between the bonding material and the core block are poor, so it has been difficult to sufficiently increase the bonding strength between the two core blocks. For this reason, conventional products have a bond reinforcing groove formed in the half core, and various brazing materials such as silver solder with high bonding strength are used as the bonding material to fill the bonding reinforcing groove. The increasing means could not sufficiently increase the bonding strength between the half core and the bonding material, and could not effectively solve the problem of peeling from the bonded surface between the two.

``Object of the Invention'' Based on the awareness of the problems with conventional products, the present invention provides a magnetic head that can increase the bonding strength of a pair of half cores having notched grooves that regulate the magnetic gap width, and a method for manufacturing the same. The purpose is to obtain.

"Summary of the Invention" The present invention shows that the low bonding strength of a pair of half cores is ultimately due to poor bonding between the notch grooves of the pair of half cores made of a metal material and the non-magnetic bonding material filled therein. It was completed as a result of research into materials or processes with high bonding properties, with the recognition that glass materials are used as the bonding material, and in order to increase the bonding strength between this glass material and the notch groove of the half core. A thin film layer of one or more active metals selected from the group consisting of Ti, Zr, Hf, Cr, No, and W is formed on the contact surface of the notched groove with the bonding glass material. . These active metals have the property of easily diffusing into the metal material constituting the half core and the bonding glass at low temperatures, so that the notch groove of the half core and the glass material can be firmly bonded.

Therefore, the bonding strength between the half cores that are integrated through the bonding glass is also increased.

Furthermore, the method of the present invention does not require forming an active metal thin film layer on the abutting surfaces of the pair of half cores.

This paper proposes a method for easily manufacturing the above-mentioned magnetic head core by forming an active metal thin film layer only in the notched grooves, in which a pair of half core blocks having notched grooves for regulating the magnetic gap width are butted together including the notched grooves. An active metal thin film layer made of the above metal is formed on the surface, and then in the notch groove,
After filling the bonding glass material, the abutting surfaces of the pair of half core blocks are cut and removed to a depth where the active metal thin film layer is removed.1. Furthermore, the pair of half core blocks are butted against each other and then heated to integrate the bonded glass materials in the opposing notch grooves.

Further, the bonding strength between the active metal thin film layer and the notch groove of the half core becomes even stronger when the active metal layer is oxidized and then filled with a bonding glass material.

"Embodiments of the Invention" The present invention will be described below with reference to illustrated embodiments. Figure 2 (a
) or D are process diagrams of the method of the present invention.

10.20 each indicates an I\-fucoa block made of a crystallized metal magnetic material such as sendust or permalloy,
The half core block 10 includes /\-fucore block 2
At the abutting surface ti with 0, cut grooves 12 formed at constant intervals and which regulate the magnetic gap width, and bond reinforcing grooves 13 continuous in the longitudinal direction of the core block are formed.

On the other hand, the half core block 20 has a notch groove 22 that matches the notch groove 12 and a bond reinforcing groove 23 that opposes the bond reinforcing groove 13 on the abutting surface 21 with the half core block 10 .

A winding groove 24 is formed parallel to the bond reinforcing groove 23 and crossing the notch groove 22.

Half core block 10.20 with the above groove processing
A thin active metal film layer 15.25 is then formed on the abutting surface 11.21. This active metal thin film layer 15.
25 is Ti, Zr, Hf.

One or more active metals selected from the group consisting of Cr, No, and W are deposited on the abutting surfaces 11.21 by plating, vapor deposition, or sputtering, and the active metal thin film layer 15 is formed in the notched grooves. 12 and the inner surface of the bonding reinforcing groove 14, the same thin film 25 is simultaneously formed on the inner surface of the notched groove 22), the bonding reinforcing groove 23, and the winding groove 24. This active metal thin film layer 15.25 covers the core 10.2.
It diffuses well with 0 and is strongly integrated with it. The thickness of this active metal thin film layer 15.25 is 1, for example 0.1 to Ipm.
It is good to say.

This active metal thin film layer 15.25 is then preferably oxidized to form an oxide film 16.26 on its surface.
That is, the active metal thin film layer 15.25 itself diffuses well into the glass material and the core material, as described above, but
The oxidation treatment further improves the diffusivity of the glass material oxide. The oxidation treatment may be heat treatment, plasma oxidation, or chemical oxidation.

In the case of heat treatment 1. Heating is performed in the air at a temperature of, for example, 100° C. or higher and lower than the recrystallization temperature of the metal material to be oxidized for 1 to 30 hours. Active metals oxidize at relatively low temperatures, but the oxide film often becomes passivated, so even if treated at high temperatures, the amount of oxidation can be suppressed.For example, heating Cr at 850°C for 5 hours Even when heated at 250° C. for 20 hours, the obtained oxide film thickness is almost the same. The heating atmosphere may be a mixed gas with a suppressed oxygen content. According to this heat treatment, the processing strain that occurs when forming the grooves in the half core blocks 10 and 20 can be removed by annealing, so that the magnetic properties can also be improved. At the same time, active metals (pure metals) are coated on the surface of metal materials such as sendust, which has the accompanying effect of reducing dirt and air bubbles in the glass.

Plasma oxidation also involves adding plasma to the active metal thin film layer 15.
25 to form oxidized 11i16.26 on its surface. The thickness of the oxide film 16.26 is approximately 20 to BO% of the thickness of the active metal thin film layer 15.25.

The half core blocks IO and 20 that have undergone the above processing are then provided with their notched grooves 12 and bond reinforcing grooves 13, as well as parts of their notched grooves 22), bond reinforcing grooves 23, and winding grooves 24, respectively, as shown in FIG. As shown in (d), a bonding glass material 17.27 such as low melting point glass is introduced in a molten and softened state. The bonded glass material 17.27 then forms the active metal thin film layer 15.
．． 25 and become strongly integrated. At this time, if an oxide film 16.26 is formed on the active metal thin film layer 15.25, diffusion with the glass material 17.27 will be performed more easily and the bonding strength will be increased. That is, the bonding glass material 17.27 causes oxygen diffusion with the oxide film 16.26, and the bonding glass material 17.27 is firmly bonded to these active thin film metal layers 15.25, that is, the respective grooves of the block 1O120. be done.

Next, this half core block 10.20 is
), as shown by the cutting line C-C, the butt surface 11.2
The active metal thin film layer 15.25 on one surface is cut and removed to a depth to form new abutting surfaces 1B and 28.

This new abutment surface 18.28 is the abutment surface 11.
The active metal thin layer 15.25 on the surface of 21 and the bonding glass material 17.27 protruding from this active metal thin film layer 15.25 are shaved to form a new smooth abutting surface.

This new butting surface 1 of half core block 1O120
At 8.28, a gap-filling material 19 is deposited on at least one of them. This gap filling material 19 is formed by sputtering 5i02, for example. This gap-filling material 19 is of course the bonding glass material 18.
It also adheres to the surface of 28.

The half core blocks IO and 20 are first butted together with the gap filling material 19 sandwiched between the new abutment surfaces 18 and 28, and the notch grooves 12 and 22 aligned,
heated. Due to this heating, the bonded glass materials 16 and 26 are softened and integrated, and as a result, the half core blocks 10 and 20 are also integrated. That is, the bonding glass material 16 is firmly integrated with the notch groove 12 and the bonding reinforcing groove 13 by the active metal thin film layer 15,
Similarly, the bonding glass material 26 is firmly integrated into the cutout groove 22 and the bonding reinforcing groove 23 by the active metal thin film layer 25, and since the bonding glass materials 16 and 26 are melted and softened and integrated, the half The core blocks 10 and 20 are firmly integrated.

The joined block 30 that has been joined through the above steps is then removed by cutting and removing the unnecessary portion below the joining reinforcing groove 13 and the joining reinforcing groove 23 as shown by the cutting line D-D. and the center part of the notch groove 22 in the width direction is cut along the cutting line E-
It is then cut in sequence as shown by E to complete the process as shown in FIG. In this completed state, there is no active metal thin film layer on the surfaces of the new abutting surfaces 18 and 28 that are joined with the gap filling material 19 in between, and the bonded glass between the cutout grooves 12 and 22) and the bonding reinforcement grooves 13 and 23 is not present. Since the active metal thin film layer 15, 25 is formed only in the contact area between the materials 16 and 26, it is magnetically stable. Of course, the gap-filling material 19 also serves to join the half-core blocks IO and 20 with a constant bonding strength, but the active metal thin film layer 15.
25 and the bonding strength of the half core block lO and 20 by the bonding glass material 17.27 is the gap filling material 19
Therefore, the half core blocks 10 and 20 can be firmly joined together. Note that the winding groove 24
As is well known, a coil is wound around the coil.

In the above embodiment, a pair of half core blocks 10 and 20
Since bond reinforcing grooves 13 and 23 are formed in each of the blocks, the two blocks can be bonded more firmly. However, these bond reinforcing grooves 13 and 23 serve as an auxiliary function to the notched grooves 12 and 22, and even when these bond reinforcing grooves are not formed, the active metal thin film layers 15 and 25 of the notched grooves 12 and 22 Since it is well integrated into the bonding glass materials 17 and 27, both blocks can be bonded with high bonding strength.

Of course, the notch grooves 12 (and the bonding reinforcement grooves 13
) and the notched grooves 22 (and the bond reinforcing grooves 23) of the half core block 20, the active metal thin film layers 15 and 25 may be formed only in the notched grooves 22 (and the bond reinforcing grooves 23), but according to the method of the present invention described above, this can be easily manufactured. be able to.

"Effects of the Invention" As described above, in the magnetic head core of the present invention, the bonding glass material that joins the pair of half cores is filled in the opposing notch grooves that regulate the width of the a and air gears, and that the notch grooves are Since the active metal thin film layer is formed, the glass material and the notched groove can be firmly bonded. Since the glass materials in the opposing notched grooves can be easily integrated by heating them, the notched grooves as a whole, that is, the pair of half cores, can be joined with high bonding strength.

Further, according to the method of the present invention, the active metal thin film layer is formed only on the inner surface of the notch groove, and the abutting surfaces of the half cores can be easily processed so that no active metal thin film layer exists. Head cores can be manufactured efficiently.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of a completed state showing an embodiment of the magnetic head core of the present invention, and FIGS. 10.20...half core block, 11.21...
・Abutment surface, 12.22... Notch groove, 13.23
... Bonding reinforcement groove, 15.25 ... Active metal thin film layer. 16.26... Oxide film, 17.27... Bonding glass material, 18.28... New butt surface, 19... Gap filling material, 24... Winding groove. First cause Figure 2 (b) (C) Figure 2 (f) Figure 2

Claims (7)

[Claims] (1) A magnetic head core in which a notched groove that regulates the magnetic gap width is formed on the abutting surfaces of a pair of half cores made of metal materials that constitute a magnetic gap, and this notched groove is filled with a bonding glass material to join both half cores. In,
The contact surface of the notch groove with the bonding glass material is coated with Ti and Zr.
, Hf, Cr, Mo, and W. , Hf, Cr, Mo, and W. (2) In claim 1, each of the pair of half cores is formed with a bond reinforcing groove facing each other, and an active metal thin film layer is also formed on the contact surface of the bond reinforcing groove with the bonding glass material. Has a magnetic head core. (3) A magnetic head core according to claim 1 or 2, wherein the active metal thin film layer is formed by plating, vapor deposition, or sputtering. (4) A magnetic head core according to any one of claims 1 to 3, wherein the active metal thin film layer is further oxidized. (5) A pair of half core blocks made of metal materials are each formed with a notch groove that regulates the magnetic gap width, and the abutting surfaces of the pair of half core blocks including the notch grooves are coated with Ti, Zr, Hf, Cr, After forming a thin film layer of one or more active metals selected from the group consisting of Mo and W, and then filling the above-mentioned cutout groove with a bonding glass material, the pair of half core blocks are butted together. The feature is that the surface is cut and removed to a depth that removes the active metal thin film layer, and the pair of half core blocks are butted together and then heated to integrate the bonded glass materials in the opposing notched grooves. A method for manufacturing a magnetic head core. (6) In claim 5, each of the pair of half core blocks is formed with bonding strengthening grooves facing each other, and the bonding reinforcing grooves are also provided with an active metal thin film layer in the same manner as the notched grooves. A method for manufacturing a magnetic head core, which includes filling a bonding glass material, cutting a butt surface, and heating after the butt. (7) A method of manufacturing a magnetic head core according to claim 5 or 6, wherein the half core block is subjected to oxidation treatment after forming the active metal thin film layer and before filling the bonding glass material.