JPH024055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of forming a magnetic gap.

Conventional configurations and their problems In the field of magnetic heads, there is a strong desire to form magnetic gaps with good reproducibility and productivity, and in recent years it has become widely used to form spacer thin films by sputter deposition. It's starting to become easier. When forming a thin film using such a method, it is necessary to monitor the film thickness.

Conventionally, to monitor the thickness of a deposited film during deposition, for example, the deposited film is deposited on a crystal resonator, and the resonant frequency is determined from the change in resonance frequency caused by the deposition of the deposited film. It was determined from the mutual interference intensity of the light reflected from the surface and the surface of the thin film attached to the substrate.

Fig. 1 shows the main parts of a conventional sputter deposition apparatus and film thickness monitoring apparatus using mutual optical interference, in which 1 is a target electrode, 2 is a substrate holder surrounding this target electrode 1, and 6 is a sputter apparatus base. .
A substrate 3 to be deposited is held on a substrate holder 2. In this case, the light introduction hole 4 is provided in the substrate holder 2.
A light beam 5 is introduced from the outside through the light introduction hole 4 and guided to the surface of the substrate 3. The light reflected from the surface of the substrate 3 is led out again through the light introduction hole 4, and when the temporal change in the intensity of this reflected light is observed during vapor deposition, vibration characteristics as shown in FIG. 2, for example, are obtained. The thickness of the deposited film during deposition can be obtained from the period of . In FIG. 2, n indicates the refractive index of light in the deposited film, and λ indicates the wavelength of the introduced light beam. This type of film thickness monitoring device is effective for monitoring the thickness of transparent deposited films, but the thickness distribution of the deposited film becomes large near the introduction hole, making it difficult to form a film with a uniform thickness on the substrate. The disadvantage of this method is that the substrate cannot be placed near the introduction hole, which reduces the number of substrates to be processed. In particular, when forming the magnetic gap of a magnetic head using a spacer thin film, an extremely uniform film thickness distribution is required, and a solution to the above-mentioned drawbacks is desired.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and an object of the present invention is to provide a method for forming a magnetic gap that can form a magnetic gap having a uniform gap length with good reproducibility and high productivity. do.

Structure of the Invention In order to achieve the above object, a thin glass layer of a low permeability material is deposited on at least one surface of a pair of high permeability magnetic materials of the present invention, and the pair of high permeability magnetic materials are When bonding via a thin glass layer of a low magnetic permeability material to form the magnetic gap of the magnetic head, the method of depositing the thin glass layer includes at least a target electrode and a substrate surrounding the target electrode and having a high magnetic permeability on the inner surface. The substrate holder is provided with a light introduction hole, and conductive transparent glass is inserted into the light introduction hole. The introduced light is guided to the surface of the substrate, and the thickness of the thin glass layer is monitored from the mutual interference intensity of the light reflected from the surface of the substrate and the surface of the thin glass layer attached to the substrate.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

That is, the present invention provides the apparatus shown in FIG.
When forming the magnetic gap of the magnetic head,
As shown in FIG. 3, the occurrence of film thickness distribution due to the presence of the light introduction hole 22 in the substrate holder 21 is prevented by attaching conductive glass 23 to the light introduction hole 22, and the substrate holder 21 is The number of fillings is increased. In this case, a transparent glass plate whose surface is coated with a transparent conductive film can be used as the conductive glass 23. Further, as the light beam 24 passing through the light introduction hole 22, a He--Ne laser beam is practical. By attaching the conductive glass 23 to the light introduction hole 22 as described above, the fourth
The characteristics shown in the figure can be obtained. Figure 4 shows the film thickness distribution near the light introduction hole when a light introduction hole with a diameter of 10 mm is provided in a cylindrical substrate holder with a diameter of 10 cm. ) shows the case where the conductive glass according to the present invention is inserted and attached to the light introduction hole. It is confirmed that the film thickness distribution near the light introduction hole is completely eliminated by the present invention.
The reason why the film thickness distribution decreases is thought to be mainly because the disturbance of the electric field near the light introduction hole is reduced by the presence of the conductive glass, and a uniform sputtering discharge is maintained.

By the way, this sputter deposition method is effective for processing magnetic heads, such as magnetic gaps used in forming high-precision magnetic heads for video signals. Figures 5 to 7
This will be explained in more detail using figures. In FIG. 5, a pair of high magnetic permeability magnetic materials 3, such as ferrite, etc.
On at least one surface 32, 32 of 1, 31,
As shown in FIG.
Deposit at 0.3 μm while monitoring the film thickness as described above. In this case, the film thickness accuracy should be 50 Å to 100 Å or less. These pairs of high magnetic permeability magnetic bodies 31, 31 are joined together via the glass thin layers 33, 33,
These are sliced to form a magnetic core having a magnetic gap 34 as shown in FIG. Usually, a coil 35 is wound around this to form a magnetic head.
In this case, the width of the magnetic gap 34 corresponds approximately to the thickness of the thin glass layers 33, 33, and is in the submicron range. Furthermore, since the processing accuracy is required to be 50 Å to 100 Å or less, the film thickness distribution is also required to be 3% or less. Although conventional techniques are insufficient for mass production that satisfies these precisions, the sputter deposition method described above makes this possible.

Effects of the Invention As explained above, according to the present invention, the magnetic gap of a magnetic head having a gap with high dimensional accuracy can be formed with good reproducibility and productivity, and its industrial utility value is extremely large. .

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is a characteristic diagram of the conventional example, Fig. 3 is a sectional view of essential parts showing a basic embodiment of the present invention, Fig. 4 is a characteristic diagram of the present invention, and Fig. 5 7 to 7 are explanatory diagrams showing the manufacturing order of a magnetic head in a specific embodiment of the present invention. 21... Basic holder, 22... Light introduction hole, 23...
Conductive glass, 24...Light beam, 31...High magnetic permeability magnetic material, 32...Surface, 33... Glass thin layer, 34... Magnetic gap.

Claims (1)

[Scope of Claims] 1. A thin glass layer of a low magnetic permeability material is deposited on the surface of at least one of a pair of high magnetic permeability magnetic materials, and the pair of high magnetic permeability magnetic materials are coated with the glass of the low magnetic permeability material. When bonding through a thin layer to form a magnetic gap of a magnetic head, the method for depositing the thin glass layer includes at least a target electrode and a substrate holder surrounding the target electrode and having a substrate with high magnetic permeability on the inner surface. A light introduction hole is provided in the substrate holder, a conductive transparent glass is inserted into the light introduction hole, and at least the light introduced from the light introduction hole during the sputter deposition is transferred to the substrate. A method for forming a magnetic gap, characterized in that the thickness of the thin glass layer is monitored from the mutual interference intensity of the light guided to the surface and reflected from the surface of the substrate and the surface of the thin glass layer attached to the substrate. 2. The method for forming a magnetic gap according to claim 1, characterized in that a He--Ne laser is used as the light used to monitor the film thickness. 3. A method for forming a magnetic gap according to claim 1, characterized in that a transparent glass plate whose surface is coated with a transparent conductive film is used as the conductive transparent glass.