JPH03116410A - Substrate material for magnetic head and magnetic head using the material - Google Patents

Abstract

PURPOSE:To reduce the steps between the substrate and a metallic magnetic material, the so-called uneven wear, when a tape is traveled and to eliminate a decrease in the head output due to a spacing loss by using a specified oxide as the substrate material. CONSTITUTION:An amorphous alloy film 7 is formed on a substrate 6 of a sintered oxide consisting essentially of CuO and CoO, and a substrate 9 of the same material as the substrate 6 is made to adhere with an adhesive glass layer 8 to form a core. A coil window 10 is worked on the gap abutting surface, the abutting surface is specularly finished, and a gap spacer material is sputtered on the surface in specified thickness. The laminated core halves consisting of the same structures 6'-9' as the block are abutted on one another with adhesive glass 11 to form a gap. Since the substrate material has a thermal expansion coefficient almost equal to that of the amorphous alloy, the alloy film 7 is not released. Consequently, the uneven wear between the substrate and the metallic magnetic material when a tape is traveled and a decrease in the head output are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a non-fi magnetic head substrate material for depositing a soft magnetic metal film and a magnetic helad using the same.

Conventional technology Traditionally, it has good workability as a core material for magnetic heads.

Ferrite is widely used because of its good wear resistance, but its saturation magnetic flux density BS is 30% lower than that of alloy materials.
~50% lower. Therefore, when used in high-density recording media with high coercive force that has appeared in recent years, magnetic saturation of the head core material becomes a problem, and ferrite materials are less likely to generate sliding noise during tape running than alloy materials. Since it is large, it has the disadvantage of poor S/N ratio. From this point of view, sendust and amorphous metal magnetic materials are used as head core materials for heads compatible with high-density recording media. A head using a metal magnetic material has a so-called sand inch structure in which a metal magnetic material 4 on the tape sliding surface with a gap 5 formed therein is sandwiched between non-magnetic substrate materials 3, as shown in FIG. Crystallized glass is used as a non-magnetic substrate material at this time. In this case, as shown schematically in FIG. 4, a problem arises in that there is a difference in level between the substrate 1 and the metal magnetic material 2 when the tape runs, so-called uneven wear. That is, the head output is reduced due to spacing loss due to the magnetic material falling against the substrate.

As a solution to these problems, a calcium titanate (CaTiO3) based ceramic material has been proposed as a material for a magnetic head substrate for high-density recording media, particularly for metal-deposited tapes. However, ceramic substrates made of such materials have very poor machinability, and the cutting speed with a diamond cutter, for example, is 175 times faster than that of ferrite materials.
~1/1O, making mass production of magnetic heads difficult.

Problem to be Solved by the Invention In a magnetic head with a so-called sandwich structure in which a metal magnetic material is sandwiched between non-magnetic substrate materials, there is little level difference between the substrate and the metal magnetic material, so-called uneven wear, when the tape runs, that is, with respect to the substrate. To obtain a substrate material with good machinability without deterioration of head output due to spacing loss caused by magnetic material falling in.

Means for Solving the Problems The substrate material for the magnetic head is composed of a ceramic material made of an oxide mainly composed of CuO--CoO.

Since the working substrate has the same thermal expansion coefficient as the metal magnetic material,
A magnetic film can be produced using a thin film production device, and Mn-
It is possible to perform machining similar to that of Zn ferrite, and magnetic heads using Zn ferrite as a substrate will have fewer steps between the substrate and the alloy magnetic material, so-called uneven wear, even when the tape is running, so there will be no drop in head output (a stable head). I get the output.

EXAMPLE Hereinafter, a substrate material for a magnetic head according to an example of the present invention will be explained with reference to the drawings.

Example 1 Cub, Co to have the composition shown in Table 1.

were weighed, mixed for 16 hours in a ball mill, dried, calcined in the air at 800°C for 1 hour, mixed again for 16 hours in a ball mill, added water as a binder after drying, and molded in a hydraulic press. After molding at 500 kg/cd using
Hot press sintering was carried out by holding pressure with CD. The thermal expansion coefficient of the sintered body obtained in this way and the load current value of the spindle motor when cutting the sintered body of the same size with a diamond cutter are 1 when cutting the Mn-Zn ferrite of the same size.
Table 1 shows the values normalized to machinability. Both materials are smaller than calcium titanate (CaTiO3), easy to cut, and exhibit workability close to that of ferrite.

(Margin below) Table Embodiment 2 A magnetic head according to a second embodiment of the present invention will be described with reference to FIGS. 1 and 2. A sintered body having the composition shown in Table 1 is used as a substrate material, mirror-polished and thoroughly cleaned to form a substrate 6.
After evacuating the vacuum chamber to 3 x 10” Torr,
An amorphous alloy film 7 having a thickness of 30 μm was prepared by introducing r gas to set the pressure to 2×10 2 Torr and sputtering COs+Nb+3Zra as a target composition. A substrate 9 made of the same material as the other substrate 6 was bonded through a glass bonding tank 8 to obtain a core. After processing a winding window 10 on the abutting surface of the gear gear, the abutting surface was mirror-finished with diamond paste. After processing this surface, 5i02 is spun as a gap spacer material to a predetermined thickness to complete one side for forming a gap.

A half laminated core having exactly the same structure 6' to 9' as this block was butted against each other, and a gap was formed using adhesive glass 11. A predetermined head was cut out from this pair of bars. As a comparative example, a head using crystallized glass as a substrate was also produced.

When these heads were attached to a video tape recorder (head-tape relative speed 3.8 m/sec) and a tape running test was conducted using metallized tape, it was found that the head output using the crystallized glass substrate was significantly reduced. In contrast, stable output was obtained with the head using the material of the present invention for the substrate. Table 2 shows the level difference between the substrate and the metal magnetic material and the head output after 100 hours of running the metal-deposited tape.

Table 2 shows the output values when the initial value is OdB. Although the composition of the substrate materials in Table 2 was not limited, almost the same results were obtained as long as the claims were within the scope of the claims.

In this application, we have limited CuO to 20 to 90 mol% and CoO to 10 to 80 mol%, because if this range is exceeded, the thermal expansion coefficient will be 13.
This is because if the temperature is 0x107/°C or higher or 100xlO"/"C or lower and an amorphous alloy is deposited using a sputtering device or the like, the alloy film may peel off. In addition, if CuO exceeds 90 mol% or CoO exceeds 80 mol%, sintering properties will be poor (and a sufficiently dense sintered body will not be obtained. The inclusion of nitrides, carbides, etc. is permissible as long as it does not impair the coefficient of thermal expansion and machinability.Also, as an amorphous alloy film, C0-M (M is Nb, Ti,
at least one selected from metal elements such as Ta, Zr, W, etc.) or Go-M'-M"(M',M" are the above M
(at least one selected from the metal elements shown in ) as well as Si.

There is no particular disadvantage in metal-metalloid systems containing B, C, and P.Although in the above embodiment, the helad core is a layer of metal magnetic material, it is also possible to alternately configure the magnetic material and the glabella m-edge material. A similar effect can be obtained with the laminated core.

There is no particular limitation on the composition of sendust alloy, and Fe
-3t -A1 alloy composition is effective.

Similar effects can be expected for permalloy (iron-nickel alloy), which is an alloy magnetic material.

Effects of the invention By using a ceramic material made of oxides mainly composed of CuO-CoO for the magnetic head, it has better machinability than the conventional calcium titanate (CaTiO9), making it easier to process. Since the thermal expansion coefficient of the magnetic head is almost the same as that of the amorphous alloy, there is no fear that the alloy film will peel off even if it is deposited using a sputtering device or the like.

When a tape runs in a magnetic head with a so-called sand inch structure in which a metal magnetic material is sandwiched between non-magnetic substrate materials, there is less uneven wear between the substrate and the metal magnetic material than with a crystallized glass substrate. There is no drop in head output due to spacing loss due to the fall of the magnetic material (therefore, stable output can be obtained, and a magnetic head with high reliability can be provided).

[Brief explanation of drawings]

FIG. 1 is a front view showing a tape sliding surface of a magnetic head according to an embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a front view showing a tape sliding surface of a conventional magnetic head and a magnetic head of the present invention. figure,
FIG. 4 is a sectional view of the tape sliding surface of a conventional magnetic head. 6.6゛...Substrate, 7,7°...Amorphous alloy, 8,8゛...Glass layer for adhesion, 9,9
°... Board, 10... Winding window, 11.
...Adhesive glass, 12...Gap. Figure 1 Figure IO-, 4th ball also +1---↑ in the 1st team'Raz 5---Giyanoa t-5 class 2-- belongs to N.

Claims (6)

[Claims] (1) A substrate material for a magnetic head characterized by being made of an oxide mainly consisting of CuO-CoO. (2) A substrate material for a magnetic head characterized by comprising 20-90 mol% of CuO and 10-80 mol% of CoO. (3) Thermal expansion coefficient is 100 to 130 x 10^-^7/℃
The substrate material for a magnetic head according to claim 1, characterized in that it has the following. (4) At least the tape sliding surface of the head chip that comes into contact with the magnetic tape has a sandwich structure in which a magnetic material is sandwiched between substrates, and the substrate material is made of a material consisting of an oxide mainly consisting of CuO-CoO. magnetic head. (5) The magnetic head according to claim (4), wherein the magnetic material is made of an amorphous alloy. (6) The magnetic head according to claim (4), wherein the magnetic material is made of Sendust alloy or Permalloy alloy.