JPS5860422A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To increase the adhesive strength between a magnetic material and a winding conductor, to obtain high work precision, and to facilitate the coating of an insulating layer, by employing the two-layered structure, formed by stacking a ''Permalloy '' thin film and a copper thin film successively, to a base layer for electrodeposition of the winding conductor of a thin-film magnetic head. CONSTITUTION:On a magnetic material substrate 1, a ''Permalloy '' layer 2a' is vapor-deposited to a 100Angstrom thickness, and then a copper layer 2b is vapor-deposited to a 1,000Angstrom thickness to form a base layer of two-layered structure for electrodeposition. A prescribed pattern is obtained by photoetching. During this etching, the end part of the permalloy layer 2a' is never etched more inside than the end part of the copper layer 2b to allow the layer 2b to project in a pent roof shape. Therefore, when a conductor (copper) layer 2c for winding is electrodeposited next, the layer 2c has no defective adhesion part on the substrate 1, and on the layer 2c, an insulating layer is formed thinly and excellently by vapor-depositing SiO2, etc. Thus, the thin-film magnetic head is formed at high yield with good precision.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin film magnetic head used for recording and reproducing in magnetic disk units and magnetic tape devices.

Generally, a thin film magnetic head has a structure as shown in FIG. Figure (a) shows a case with a single winding, and figure (1)) shows a case with a plurality of windings. These heads are manufactured by attaching a conductor layer (hereinafter referred to as lead) for carrying a signal current to a magnetic substrate 1.
2 is formed, and an insulating layer 3 and a magnetic layer 4 are laminated in this order on this lead 2-1-. At the rear end of this head, the magnetic substrate 1 and the magnetic layer 4 are magnetically superposed, while at the tip of the head, the magnetic substrate 1 and the magnetic layer 4 are separated by an insulating layer 3. They face each other, and the thickness of the insulating layer 3 forms a head gap.

In particular, in the case of a thin film magnetic head such as the one described above, which has multiple windings (multi-turn leads) as shown in FIG.
Since the adhesion area between the lead 2 and the magnetic substrate 1 is narrow, the lead 2 tends to peel off during the processing or operation process of the head. Therefore, a large adhesion strength is required between the lead 2 and the magnetic substrate 1. Ru.

In addition, in the above-mentioned plurality of windings, a high degree of accuracy is required in the adjustment of the leads 2 in order to prevent the occurrence of short circuits between the leads 2.

Further, the leads 2 and the magnetic layer 4 need to be completely insulated by the insulating layer 3, and for this reason, the stepped shape of the leads 2 needs to be such that they can be easily covered with the insulating layer 3. (It is better to form the lead 2 by electrodeposition than by vapor deposition or sputtering because the step shape of the lead is made of SiO2.
, 5i02, etc., so that it can be easily covered with an insulator. ) Based on the above requirements, the four requirements for the lead part of a thin film magnetic head are (1) to be formed with high processing precision, (ii) to have high adhesion strength with the magnetic substrate (111) Covering with an insulating layer is easy.

Conventionally, in order to strengthen the adhesion strength of the vapor deposited film to the substrate, for example, as shown in FIG.
1) Mr, Ti as the adhesive layer (2a) of ).

Cr etc. were sometimes used. However, when these two-layer films are processed and formed using the same etching solution, the edges of the upper vapor-deposited film 2b are disturbed at the etched ends. Further, when these two-layered films are etched separately, digging occurs in the adhesion layer at the etched end, as shown in FIG. 2(a). Adhesion is poor in this portion, and depending on the shape of the pattern formed by etching, there is a serious problem in terms of adhesion strength. Therefore, even if such a vapor-deposited two-layer film is used as an electrodeposition base and a copper layer 2C is electrodeposited on top of it to form a lead (Fig. 2 (1)), the above-mentioned intrusion will increase the width of the lead part of the thin film head (80 μm). degree), and it was impossible to produce good leads.

The present invention aims to provide a thin-film magnetic head that satisfies all two points required for the lead portion of a thin-film magnetic head.
to be myself.

Hereinafter, one embodiment of the present invention will be described in detail.

FIG. 3 is an explanatory diagram of the manufacturing process of the film magnetic head according to the present invention. The figure (a) shows a state in which a two-layer film serving as a base for electrodeposition is formed on a magnetic substrate 1 such as an insulating ferrite substrate containing nickel and zinc, and the figure (b) shows a state in which a two-layer film is formed as a base for electrodeposition. 2 shows the state in which an electrodeposited film is formed.

” 1. For the two-layer film, first, a permalloy (iron-nickel alloy) layer 2a' of 100λ is deposited, and then a copper layer 2b is deposited in the same vacuum.
was vapor-deposited at a density of 100 OA, and then processed into a predetermined pattern by photo-etching. In this etching process, an aqueous solution prepared by adding water to 20 y of ammonium persulfate, 2 cc of hydrochloric acid, 2 cc of nitric acid and 2 cc of nitric acid is used as an etching solution at a liquid temperature of 40°C.

As shown in FIG. 2(b), a copper layer 2c is formed on the two-layer film to a predetermined thickness by electrodeposition, and the copper layer 2c has a thickness of 90%.
A lead layer having a thickness of about 1.0 μm was obtained by electrodeposition at a wavelength of 00λ.

Next, this lead layer is coated with 5i02 with a thickness of 20 to 23 μm.
The step was covered with spatter film.

According to the manufacturing process described below, in terms of processing accuracy, the thickness of the permalloy layer 2a' and the amount of side etching of the electrodeposition base film made of these two layers are about 1.0 μm. If an electrodeposition layer is electrodeposited on top of this to a thickness of 1.0 μm, the length of the spread of the lead end due to this electrodeposition is 10
It is on the order of μm, and sufficient machining accuracy can be achieved.

Further, the adhesion strength can be made strong enough to cause no problem in processing and forming the head element.

Regarding the coating of the insulating layer, if the above-mentioned etching solution is used, the shape of the two-layer film serving as the base for electrodeposition is such that the end of the permalloy layer 2a' is the end of the copper layer 21), as shown in FIG. 3(a). Therefore, the shape of the end face of the copper layer 2c after electrodeposition does not show any digging part, as shown in FIG. 1 (1). Therefore, the step cover by the insulating layer of the copper layers 2C and J- can be made thin and well.

As described above, according to the thin film magnetic head according to the present invention, (1) (11
) (Ill), and it is possible to obtain high-performance leads.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view showing the structure of a conventional thin-film magnetic head, and FIG. 2 is an explanatory diagram of the manufacturing process of a conventional thin-film magnetic head.
FIG. 3 shows an explanatory diagram of the manufacturing process of one embodiment of the thin film magnetic head according to the present invention. In the figure 1 = Magnetic substrate 2: Lead 3: Insulating layer
4: Magnetic layer agent Patent attorney Aihiko Fukushi

Claims (1)

[Claims] 1. A magnetic material is provided with a structure in which a winding conductor is coated, and a thin film having a two-layer structure consisting of a permalloy^V film and a copper M base film is provided as an electrodepositing base layer of the winding conductor. Features a thin film magnetic head.