JPH04248104A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the mass-productivity by forming so as to prohibit the protrusion of low melting point glass to the bottom surface of an opposite side against the sliding surface and griding the sliding surface by making the bottom surface in the opposite side against the sliding surface as a reference plane. CONSTITUTION:Since the depth of the groove 5 is formed so as to be shallower from the surface corresponding to the sliding surface 15 to the surface 14a corresponding to the bottom surface in the opposite side against the sliding surface 15, the low meting point glass 3 is not protruded on the surface 14a when the low melting point glass is filled. Thus, the surface 15a corresponding to the sliding surface 15 can be ground flatly by making on the surface 14a corresponding to the bottom surface 14 in the opposite side against the sliding surface 15 as a reference plane. Thus the rereferencing stage is unnecessary, when the surface 14a is used as a reference plane, and also the degradation of the accuracy by rereferencing does not occur and the mass-production of the magnetic head is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for recording and reproducing information in a magnetic recording and reproducing apparatus such as a video tape recorder.

0002

[Background Art] With the increasing density of magnetic recording technology, magnetic recording media with high coercive force, such as metal tapes, have become mainstream, and the core materials used in magnetic heads have a high saturation magnetic flux density. something is required.

Under these circumstances, a magnetic head using a head chip 25 as shown in FIG. 8 has been prototyped.

This head chip 25 has a pair of core pieces 24.
- 24 are joined at the gap surface 23. Each core piece 24 consists of a soft magnetic thin film 22 made of a soft magnetic metal having a high saturation magnetic flux density, and substrates 21 that sandwich this soft magnetic thin film 22.
is formed perpendicular to the gap plane 23.

[0005]

However, in the above structure, strict conditions are required regarding the flatness, parallelism, thickness tolerance, etc. of the substrate 21 and the soft magnetic thin film 22 in order to manufacture the core piece 24. For this reason, there is a problem in that the manufacturing yield of the head chip 25 is reduced, which impedes mass production of magnetic heads.

[0006] Therefore, in order to solve this problem, FIG.
A magnetic head using a head chip 35 as shown in FIG. 1 has been considered.

Similar to the above, this head chip 35 has the following features:
Although the pair of core pieces 34 are joined at the gap surface 36, the soft magnetic thin film 32 is connected to the gap surface 36.
A core piece 34 is used which is formed obliquely with respect to the core piece 34 so that the soft magnetic thin film 32 is sandwiched between the substrate 31 and the low melting point glass 33.

For this reason, each core piece 34 is formed by forming a soft magnetic thin film 32 on the substrate 31 with a thickness approximately corresponding to the track width, and then covering the substrate 31 and the soft magnetic thin film 32 with a low melting point glass 33 from above. It is easily manufactured by molding.

However, in this magnetic head, when the substrate 31 and the soft magnetic thin film 32 are molded with the low melting point glass 33, the low melting point glass 33 is placed on the bottom surface 38 as a reference surface.
This has the problem that the sliding surface 37 of the magnetic tape cannot be polished using the bottom surface 38 as a reference surface unless the bottom surface 38 is set as a reference surface again. It does not solve the fundamental problem of improving mass productivity.

0010

[Means for Solving the Problems] The magnetic head of the present invention includes:
In order to solve the above problem, a pair of core pieces made of a soft magnetic thin film formed on a substrate and covered with low melting point glass are bonded together so that the cross sections of the soft magnetic thin film face each other, and a magnetic recording medium is formed. A magnetic head in which a magnetic gap is formed on the sliding surface of the magnetic head is characterized in that the low melting point glass is formed so as not to protrude from the bottom surface on the opposite side to the sliding surface.

[0011]

[Operation] According to the above structure, a pair of core pieces each made of a soft magnetic thin film formed on a substrate and covered with low melting point glass are bonded together so that the cross sections of the soft magnetic thin film face each other, and the magnetic recording medium is In a magnetic head in which a magnetic gap is formed on the sliding surface, the low melting point glass is formed so as not to protrude to the bottom surface opposite to the sliding surface. The sliding surface can be polished using as a reference surface. This eliminates the need for re-reference when using the bottom surface on the opposite side of the sliding surface as a reference surface, and
Decrease in accuracy due to re-reference will not occur, and mass productivity of magnetic heads will be improved.

0012

[Example] Regarding an example of the present invention, FIGS. 1 to 7
The explanation based on this is as follows.

As shown in the perspective view of FIG. 1, the head chip 12 used in the magnetic head of this embodiment includes a substrate 1,
It consists of a pair of core pieces 16 having a soft magnetic thin film 2 having a high saturation magnetic flux density formed on a substrate 1 and a low melting point glass 3 formed to cover the soft magnetic thin film 2. The soft magnetic thin films 2,2 on the substrates 1,1 form a head core having a magnetic gap 17, with the cross sections of the soft magnetic thin films 2,2 facing each other, and the pair of core pieces 16,16 on the gap surface 8. The configuration is such that they are joined together. The sliding surface 15 is polished to a predetermined surface roughness so that the magnetic gap 17 and a magnetic recording medium such as a magnetic tape come into smooth contact.

In the core piece 16, the soft magnetic thin film 2 is formed obliquely to the gap surface 8, and the soft magnetic thin film 2 is sandwiched between the substrate 1 and the low melting point glass 3. There is. Further, the low melting point glass 3 is formed so as not to protrude onto the bottom surface 14 on the opposite side to the sliding surface 15.

Further, in the head chip 12, in order to wind a head coil (not shown) around the head core made of the soft magnetic thin films 2, 2, as shown in the figure, from the internal winding grooves 4, 4 are provided. An internal winding hole 9 and external winding grooves 6 are formed.

The soft magnetic thin film 2 includes, for example, Fe-Al
- A soft magnetic material having a high saturation magnetic flux density such as a Si-based alloy is used. Further, the substrate 1 includes photosensitive crystallized glass,
Non-magnetic materials such as crystallized glass or ceramics, or oxide magnetic materials such as soft magnetic ferrite are used.

In the above structure, a pair of core pieces 16, which cover the soft magnetic thin film 2 formed on the substrate 1 with the low melting point glass 3, are placed in a gap such that the cross sections of the soft magnetic thin films 2 face each other. They are joined at the surface 8 to form a magnetic gap 17 between the cross sections of the soft magnetic thin films 2. Since the soft magnetic thin film 2 is formed obliquely to the gap surface 8,
The core piece 16 in which the soft magnetic thin film 2 is sandwiched between the substrate 1 and the low melting point glass 3 can be easily manufactured. Moreover, since the low melting point glass 3 is formed so as not to protrude onto the bottom surface 14 on the opposite side to the sliding surface 15, the sliding surface 15 can be polished using the bottom surface 14 on the opposite side as the sliding surface 15 as a reference surface. It can be performed. This eliminates the need for a step of re-reference when using the bottom surface 14 as a reference surface, and also prevents deterioration in accuracy due to re-reference, improving mass productivity of the magnetic head.

One method of manufacturing the above magnetic head will be described below with reference to FIGS. 2 to 7.

First, as shown in FIG. 2, grooves 5 having a V-shaped cross section are continuously formed on one side of the substrate 1 at a predetermined pitch dimension A. As shown in FIG. At this time, the depth of the groove 5 is formed to be shallow from the surface 15a corresponding to the sliding surface 15 (FIG. 1) to the surface 14a corresponding to the bottom surface 14 on the opposite side of the sliding surface 15, and , the grooves 5 are formed so as not to cover the surface 14a. Further, at this time, it is more convenient to form the groove 5 so that the edge line 18 of the groove 5 is perpendicular to the surface 14a when forming the core block 11, which will be described later.

Next, as shown in FIG. 3, a predetermined film thickness (dimension corresponding to the track width) is formed on one wall surface of each groove 5.
The soft magnetic thin film 2, for example, a Fe--Al--Si alloy, is formed by vacuum evaporation, sputtering, or the like.

Next, as shown in FIG. 4, the groove 5 is filled with low melting point glass 3. Then, as shown in FIG. 5, the filled low-melting glass 3 is polished into a flat shape so that the surface of the low-melting glass 3 matches the top surface of the substrate 1, and the gap surface 8 is Form. Further, using the surface 14a corresponding to the bottom surface 14 on the opposite side to the sliding surface 15 (FIG. 1) as a reference surface, the surface 15a corresponding to the sliding surface 15 is flat-polished,
The low melting point glass 3 protruding onto the surface 15a is removed.

Next, as shown in FIG. 6, an internal winding groove 4 and an external winding groove 6 are formed on both sides of the substrate 1, and further,
In order to obtain a predetermined magnetic gap 17 (FIG. 1) length,
A gap filling layer (not shown) made of a nonmagnetic gap material such as SiO2 is formed on the gap surface 8 by vacuum evaporation or sputtering to obtain the substrate block 10.

After this, as shown in FIG. 7, the gap surfaces 8, 8 of the pair of substrate blocks 10, 10 are aligned so as to face each other, and they are joined by applying pressure, so-called gap welding. Thus, a core block 11 is formed.

Next, the core block 11 is cut at a predetermined pitch dimension B along the two-dot chain line shown in the figure to obtain the head chip 12 shown in FIG.

After this head chip 12 is adhesively fixed to a base plate (not shown), the internal winding groove 4 is
A head coil is formed by winding using the external winding groove 6 and the sliding surface 15 with a magnetic recording medium such as a magnetic tape.
The magnetic head of this embodiment is manufactured by tape polishing.

In the above magnetic head manufacturing method, grooves are formed from the surface 15a (FIG. 2) corresponding to the sliding surface 15 (FIG. 1) to the surface 14a corresponding to the bottom surface 14 on the opposite side of the sliding surface 15. Since the depth of the groove 5 is shallow and the groove 5 is formed so as not to cover the surface 14a, when the groove 5 is filled with the low melting point glass 3 (FIG. 4), the surface 14a is filled with the low melting point glass. 3 will no longer stick out. Therefore, using the surface 14a corresponding to the bottom surface 14 on the opposite side of the sliding surface 15 as a reference surface,
Surface 15a corresponding to sliding surface 15 can be flat-polished. This eliminates the need for a step of re-reference when using the surface 14a as a reference surface, and also prevents deterioration in accuracy due to re-reference, improving mass productivity of the magnetic head.

[0027]

[Effects of the Invention] As described above, the magnetic head of the present invention has the following features.
Since the low melting point glass is formed so as not to protrude onto the bottom surface opposite to the sliding surface, the sliding surface can be polished using the bottom surface opposite to the sliding surface as a reference surface. This eliminates the need for re-reference when using the bottom surface on the opposite side of the sliding surface as a reference surface, and eliminates the loss of precision caused by re-reference, improving the mass productivity of magnetic heads. be effective.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a head chip used in a magnetic head of the present invention.

2 is a plan view of a substrate in which a groove having a substantially V-shaped cross section is formed, showing the manufacturing process of the magnetic head of FIG. 1; FIG.

3 is a plan view showing a step of forming a soft magnetic thin film on one wall surface of the groove shown in FIG. 2; FIG.

4 is a plan view showing a step of filling the soft magnetic thin film of FIG. 3 with low melting point glass; FIG.

5 is a plan view showing a step of polishing the low melting point glass of FIG. 4 into a flat shape to form a gap surface; FIG.

6 is a perspective view showing a step of manufacturing a substrate block by forming internal winding grooves and external winding grooves on both sides of the substrate of FIG. 5; FIG.

7 is a perspective view showing a step of forming a core block by combining a pair of substrate blocks shown in FIG. 6; FIG.

FIG. 8 is a perspective view showing the configuration of a head chip used in a conventional magnetic head.

FIG. 9 is a perspective view showing a possible configuration of a head chip used in a magnetic head.

[Explanation of symbols]

1　　　　Substrate 2 Soft magnetic thin film 3. Low melting point glass 14 Bottom 15 Sliding surface 16 Core piece 17 Magnetic gap

Claims (1)

[Claims] 1. A pair of core pieces in which a soft magnetic thin film formed on a substrate is covered with low melting point glass are bonded together so that the cross sections of the soft magnetic thin film face each other, so that the sliding surface with the magnetic recording medium is formed. 1. A magnetic head having a magnetic gap formed thereon, characterized in that the low melting point glass is formed so as not to protrude from the bottom surface opposite to the sliding surface.