JPH0664692B2 - Magnetic head manufacturing method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic head for writing / reading information to / from a magnetic medium.

2. Description of the Related Art In recent years, a floppy magnetic storage device (hereinafter abbreviated as FDD) using a flexible medium has been frequently used as an external storage device of a computer.

In this FDD, in order to maintain compatibility between devices due to physical and mechanical deformation of the medium and FDD tracking accuracy,
Tunnel erase type magnetic heads are often used.

FIGS. 3 to 5 are plan views of magnetic heads for FDD currently in use. The one shown in FIG. 3 is called a laminate type, and the read / write cores 2a, 2b made of a magnetic material forming the read / write gap 1 are replaced by non-magnetic materials 3a, 3b.
Erase cores 6a, 6b that form an erase gap 5 on the side surface of the non-magnetic body 4 connected to the core 2b.
Are joined together.

What is shown in FIG. 4 is called a bulk type, and grooves are formed on both sides of the read / write cores 8a, 8b forming the read / write gap 7, and a non-magnetic material such as glass is formed in the groove portions. A groove is formed between both erase gaps of the erase cores 10a and 10b that form the erase gap 9 and the groove is filled with a non-magnetic material such as glass to form a core 8b.
The two are bonded together via a non-magnetic material between 10b.

The one shown in FIG. 5 is called a stride type and has a read / write core 12a, which forms a read / write gap 11.
Erase core 1 forming erase gap 13 on both sides of 12b
4 is arranged.

By the way, in recent years, as the recording density on the magnetic medium has been increased, the bulk type among the above-mentioned three types of magnetic heads has come to be used particularly often.

This bulk type magnetic head is manufactured through the steps shown in FIG.

That is, as shown in FIG. 7A, a core 21 made of a magnetic material formed in a substantially U shape and a core 22 formed in an I shape are opposed to each other, and a gap portion is formed as shown in FIG. A bonding glass 23 is filled in and solidified to form a core block, and then a groove 24 is formed in the upper surface of the core block as shown in FIG. 7C, and the groove is filled with glass and solidified,
The core block thus grooved is shown in FIG.
The non-magnetic material 25 is sandwiched between them as shown in FIG.
It cuts at the portion A and the portion BB to obtain the shape shown in FIG. After that, although not particularly shown,
A read / write coil and an erase coil are attached, and a back bar is attached to a lower end portion of a core forming a read / write gap to obtain a magnetic head.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention By the way, there is a demand for higher density and more tracks in the magnetic memory device in the future.
(See the drawing), it is necessary to reduce the gap distance L between the lead / ride gap and the erase gap. In order to reduce the gap distance L, the thickness T of the I-shaped core (see FIG. 6 (F)) must be reduced.

However, when the thickness T of the I-shaped core is reduced by the conventional manufacturing method described above, the following problems occur.

That is, when the thickness T is reduced, the magnetic permeability decreases, and the cross-sectional area of the magnetic path in this portion decreases, which increases the magnetic resistance and deteriorates the recording / reproducing characteristics. There is a problem that the physical strength of the portion becomes small and the portion is broken when the back bar is attached.

Therefore, the method of manufacturing a magnetic head according to the present invention is formed in a U-shape, and has a first core having an open side upper part and an open side lower part and a second I-type formed core. The cores are butted so that the upper and lower parts of the open side and the second core face each other, and bonding glass is provided in the holes so that a gap is formed in the hole formed by butting the first and second cores. The core block is formed by joining the first and second cores, forming a groove across the first and second cores, and preparing a pair of the core blocks to separate the second cores from each other. The lower part of the open side of the first core was cut so that at least a part of the lower part of the open side of the first core, which was bonded to the second core by the magnetic material, remained on the second core. .

Operation In order to reduce the gap distance between the lead / ride gap and the erase gap, I
Even if the die core is thinned, the magnetic material that was originally a part of the U-shaped core remains below the I-shaped core of the obtained magnetic head, and a large cross-sectional area is secured at this portion. .

Example A method of manufacturing a magnetic head according to an example of the present invention will be described below.

FIG. 1 shows a part of the manufacturing process of the magnetic head of one embodiment.

First, the magnetic block having a rectangular parallelepiped shape is processed into a ship shape for depth control, and is formed of a substantially U-shaped core 31 as shown in FIG. 1 (A) and the same magnetic material formed in an I shape. Prepare the core 32. As shown in FIG. 2, the core 31 is ground and lapped so that the open-side upper portion 31b is lower in height than the lower portion 31c by the dimension B. This dimension B is a dimension corresponding to the gap width described later. At this point, the upper surface of each core 31
The a and 32a are also lapped.

Then, the U-shaped core 31 and the I-shaped core 32 formed as described above are opposed to each other, and the bonding glass 33 is formed so that a gap is formed in the hole formed between the U-shaped core 31 and the I-shaped core 32.
And when the gap is filled with the bonding glass 33 and solidified as shown in FIG.
An end portion 34 of a contact portion between the open-side lower portion 31c of I and the I-shaped core 32
The portion of (1) is also moulded by the same bonding glass, so that the open side lower part 31c of the U-shaped core 31 and the I-shaped core 32 are fixed, and the core block 35 is obtained. Thereafter, a groove 36 is formed on the upper surface 35a of the core block 35 as shown in FIG. 7C, and the groove portion is filled with glass to be solidified.
The side surface portion 32b of 32 is ground to a predetermined size according to the gap distance between the read / write gap and the erase gap. A pair of core blocks 35 processed in this way are prepared, and as shown in (D) of the figure, they are joined with a non-magnetic material 37 sandwiched therebetween, and then the shape of (E) is obtained. Grinding process. That is, at least a part of the open-side lower portion 31c of the U-shaped core 31 joined to the I-shaped core 32 is connected to the I-shaped core 32.
That is, the lower portion 31c on the open side of the U-shaped core 31 and the I-shaped core 32 are separated from each other.

And after that, cut at the A-A part and the BB part,
The shape shown in FIG. After that, the read / write coil 38 and the erase coil 39 are attached, and the back bar is attached to the end of the core forming the read / write gap 40.
41 is attached to obtain a magnetic head as shown in FIG.

In the magnetic head manufactured in this manner, since the portion 31d that was originally a part of the U-shaped core is still joined to the lower portion of the I-shaped core, the magnetic path cross-sectional area of this portion is conventionally The magnetic characteristics at the time of recording / reproducing are better than those of the conventional one because the magnetic resistance becomes larger than that of the conventional one (shown in FIG. 6) and the magnetic resistance becomes smaller than that of the conventional one.

In addition, the physical strength of this part was increased, and the risk of damage when the back bar was attached was reduced.

As described above, the magnetic head obtained by the method for manufacturing a magnetic head of the present invention is a magnetic head used in a magnetic recording / reproducing apparatus, which is expected to have higher density and more tracks. In order to cope with the reduction of the gap distance between the read / ride gap and the erase gap, which is unavoidable, even if the I-type core is thinned, the I-type core of the obtained magnetic head initially has a The magnetic material that had been a part of the V-shaped core will remain, and a large cross-sectional area will be secured for this part, thus not increasing the magnetic resistance and increasing the physical strength of this part. The risk of breakage when the back bar is attached is reduced, which is practically effective. Further, in addition to the above effects, since the bonding glass is provided in the hole formed by abutting the first core and the second core so that a gap is formed, the grindstone comes into contact with the bonding glass and the stress applied to the bonding glass is reduced. Even if it is alleviated at once, stress is absorbed by the gap formed between the hole and the bonding glass, and the clutch does not enter the gap or the like.

[Brief description of drawings]

FIG. 1 is a perspective view of a core in a part of a manufacturing process of a magnetic head according to an embodiment, FIG. 2 is a side view of a U-shaped core, and FIG. 3 is a plan view of a laminate type magnetic head. 4 (a) and 4 (b) are a plan view and a side view of the bulk type magnetic head, FIG. 5 is a plan view of the straddle type magnetic head, and FIG. 6 is a conventional manufacturing process of the bulk type magnetic head. It is a perspective view of the core in a part. 31 …… U-shaped core, 32 …… I-shaped core, 31b …… Opening side upper part, 31c …… Opening side lower part, 33 …… Bonding glass, 35 …… Core block, 36 …… Groove, 37 …… Non Magnetic material, 38 ... Read / write coil, 39 ... Erase coil, 40 ... Read / write gap, 41 ... Back bar

Claims (1)

[Claims] 1. A U-shaped first core having an open-side upper portion and an open-side lower portion, and an I-shaped second core having the open-side upper and lower portions and the second core. Bonding glass is provided in the hole so that a gap is formed in the hole formed by abutting the cores so as to face each other and abutting the first core and the second core.
The core and the second core are joined to each other, a groove is provided across the first core and the second core to form a core block, and a pair of the core blocks are prepared so that the respective second cores are connected to each other. And the opening of the first core so that at least a part of the lower portion on the open side of the first core joined to the second core remains in the second core. A method of manufacturing a magnetic head, characterized in that a lower side portion is cut.