JPS63268111A - Method for forming magnetic head core - Google Patents

Abstract

PURPOSE:To prevent the characteristic deterioration of a core by giving and sticking beforehand the displacement in the direction reverse to the direction deformed by the difference in the thermal expansion coefficient of both to a base when a thin film material is stuck in which the thermal expansion coefficient has the difference with a head forming base. CONSTITUTION:A core forming substrate 1 is fitted to a jig 9 used together as a base holder. At the screw hole of the center of a flattening part 10 of the jig 9, a pushing screw 11 is protrudably freely screwed, a reverse L-shaped hook 12 is provided at both edges of the flattening part 10 and by the screw 11, the base 1 can be deformed to a convex by the screw 11. Next, only for a forecasting displacement quantity 8 to occur by the thermal expansion coefficient of the base 1 and a Sendust alloy thin film 2, the base 1 is displaced with the pushing screw 11. Next, with a high frequency spattering device, a Sendust thin film 2 is stuck made vacuum in a vacuum chamber 16, a high frequency growing discharging is generated at the space of a Sendust alloy 14 and a base body structure 9' under the presence of Ar gas, a plasma is generated, and a static magnetic field is impressed by permanent magnets 19 and 19. When the body structure 9' is heated to 200-400 deg.C and removed after the spattering is completed, a thermal contraction to occur at an annealing process corrects flatly the base 1.

Description

[Detailed Description of the Invention] No. 1 This invention relates to a technology related to core processing of a magnetic head used in a magnetic recording application device such as a computer or a DAT.
Specifically, it is a technique for preventing deformation of a head core substrate when a thin film is attached by sputtering or the like.

In general, a thin film magnetic head core is made of Fe-Ml, M
A thin film core is often formed by depositing a ferromagnetic material 2 such as n-Zn ferrite in a thin film pattern. In order to form the core in this way, sputtering technology is used in most cases.
This is introduced as a prior art in No.-127211.

Recently, as shown in FIG. 5, Sendust, which has a higher saturation magnetic flux density than the core, has been added to the opposing surface forming the magnetic gap 6 of the bulk core 5 formed by joining the core halves 3 and 4. Alloy thin film 7, 7 and gap spacer thin film 5
To28 may be attached.

In these cases, a substrate 1 such as glass or a core half 4. $3゜4
Since this is a substrate on which a thin film is formed, it is usually heated to several hundred degrees Celsius in order to improve sputtering adhesion.

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By the way, when forming a thin film as described above, there is a difference in thermal expansion coefficient between the thin film material to be attached and the forming substrate. Therefore, when cooling to room temperature after sputtering, if the substrate 1 shown in FIG.
As shown in 2', warping occurs due to the difference in thermal expansion coefficient, and the strain stress at that time has an adverse effect, leading to deterioration of the core properties or, in extreme cases, damage, reducing manufacturing yield. There was a problem.

This invention is proposed in order to solve the above-mentioned conventional problems.The head core substrate to which the thin film is to be attached is prepared in advance.
After the film has been deposited, a method is employed in which the thin film is displaced in the opposite direction to the direction in which it is deformed due to the difference in thermal expansion coefficient between the head forming substrate and the thin film. That is, the present invention is a method of setting a displacement amount to correct a previously anticipated displacement of a workpiece and offsetting it.

According to the present invention, the thin film material is deposited on the head core substrate which has been displaced in advance in the opposite direction to the direction in which it is deformed due to the temperature during the film forming operation, so that after the thin film is formed, the thermal expansion coefficient of the substrate and the thin film is Due to the difference in temperature, the stress that occurs when shrinking while returning to room temperature acts to restore the preset amount of displacement to the original state.

Practical Example - Figs. 1 to 3 are conceptual diagrams of a magnetic head core substrate and a high frequency sputtering apparatus for forming a thin film, showing an embodiment of the present invention. Examples will be described below with reference to the above drawings. First, as a core forming substrate used in this example, a crystallized glass substrate with a thermal expansion coefficient of 100X 10'/''C is used. /"C sendust alloy is prepared.

First, as shown in FIG. 1, the core forming substrate 1 is attached to a jig 9 which also serves as a substrate holder. This jig 9 has a screw hole in the center of the flat part IO on which the core forming substrate 1 is placed,
A push screw 11 is screwed so that it can freely protrude slightly. Furthermore, hooks 12.12 in the shape of an inverted letter are provided at both ends of the flat portion IO of this jig 9, and when the push-in screw (■) is slightly protruded, both ends of the lath board 1, which is a workpiece, are hooked into the hooks 12.12.
12 and remains fixed, only the central portion that is in contact with the push-in screw 11 is pushed up slightly, deforming into an arch-like convex shape. Therefore, next, the push screw 11 is pushed in by a displacement amount 8 that can be predicted to be caused by the difference in thermal expansion coefficient between the glass substrate 1 and the Sendust alloy thin film 2, and the displacement is set in the convex shape shown in FIG. Next, the jig/substrate structure 3'' whose displacement has been set is taken into the high frequency sputtering device I2 shown in FIG. 3, and a sendust thin film is deposited thereon. The base body is placed opposite an electrode plate 15 equipped with a sendust alloy 14 as a target, and is housed in a vacuum chamber IB.

The base 3 is grounded together with the vacuum chamber 16, and a high frequency power source is connected to the electrode plate 15 via a matching box 17! It is connected to 8. The distance into the vacuum chamber 16 is several meters.
Torr of Ar gas is fed through a gas supply valve 20 and exhausted through an exhaust port 21 using a vacuum pump (not shown) or the like. Furthermore, in the space between the Sendust alloy I4, which is the target, and the jig/substrate structure 8', a high frequency glow discharge is caused to generate plasma, and in order to sustain the plasma sufficiently and confine it within the space, a permanent magnet 19 is installed. .19, a static magnetic field is applied across the space. Therefore, when starting sputtering, the base 13
The built-in heater heats the jig φ substrate bridge body 9' by approximately 20
The convex substrate surface is activated by heating to about 0°C to 400"C to create favorable conditions for film formation. In this way, after sputtering is completed, heating by the heater is stopped and the material is slowly cooled to room temperature. Since the coefficient of thermal expansion between the Sendust alloy thin film 2 and the glass substrate 1 is larger on the Sendust alloy thin film side as described above, the thermal shrinkage stress generated during the slow cooling process works to straighten the substrate 1 to be flat.

In the above embodiment, a crystallized glass substrate was used as the magnetic head forming substrate, and Sendust alloy was used as the thin film material.
If a G-gap head is to be formed, a Mn--Zn single-crystal ferrite may be used as the substrate, and sendust alloy or SiO2 may be laminated as the thin film material, and similar effects can be expected.

By implementing this invention, warping during the formation of a thin film on a substrate can be prevented, and the deterioration of core characteristics and the reduction in manufacturing yield due to core breakage, which conventionally occur due to distortion due to warping, can be eliminated, resulting in significant reliability. Sexual improvement can be achieved. In addition, with this invention, simply by devising the precision of the jig that displaces the board in advance,
Since the magnetic head core material can be processed to the desired flatness, it can greatly contribute to improving the workability of forming thin films.

[Brief explanation of drawings]

1 and 2 are conceptual cross-sectional views of a magnetic head forming substrate/jig structure for introducing an embodiment of the present invention;
Fig. 3 is a conceptual diagram of the high frequency sputtering device used in this example, Fig. 4 is a side view showing a general magnetic head forming substrate and thin film, and Fig. 5 is a schematic front view showing a bulk type head core. be. 1...Substrate, 2...Thin film, 9.
...Jig, 3'...Jig/board structure, 8
・・・・・・Amount of displacement. Patent applicant Kansai NEC Co., Ltd. (Otsu), 3-・
′ Parrot

Claims (1)

[Claims] When a thin film material having a coefficient of thermal expansion different from that of the substrate is deposited on a magnetic head forming substrate, the head forming substrate is deformed in advance due to the difference in thermal expansion coefficient between the head forming substrate and the thin film after the film is deposited. A method for forming a magnetic head core characterized by displacing the core in a direction opposite to that of the magnetic head core.