JPH08102009A - Production of magnetic head - Google Patents

Abstract

PURPOSE: To improve output and to enhance the reliability of products by preventing the clogging which is liable to be occurred by sliding contact of a magnetic head with a magnetic recording medium at the time of producing the magnetic head and to improve the contact characteristic with the magnetic recording medium. CONSTITUTION: The grinding surfaces 3a of a magnetic core block 3 formed with plural magnetic gaps (g) by fusing a pair of magnetic core block half bodies 1, 2 are subjected to cylindrical grinding. Next, band-shaped groove parts 16 are formed in parallel with the magnetic gaps (g) on the ground surfaces 3a of the magnetic core block half bodies 1, 2 which come into sliding contact with the magnetic recording medium on the rear side. Further, the magnetic core block 3 is cut out to respective head chips 4. These head chips 4 are adhered to head substrates and the ground surfaces 3a are polished, by which magnetic recording medium-sliding surfaces (a) are formed. The side ends 2a formed at the head chips 4 are cut off by providing the ground surfaces with the groove parts 16 in such a manner, by which notches 15 are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic head, for example, a method for processing a sliding surface of a magnetic recording medium of a magnetic head mounted on a VTR (video tape recorder).

[0002]

2. Description of the Related Art Usually, a VTR is equipped with a rotary magnetic head device having a magnetic head provided on the peripheral surface of a rotary drum. In this case, since the sliding surface of the magnetic recording medium of the magnetic head slides on the video tape which is the magnetic recording medium, recording and reproduction of images, sounds, and the like are performed, and therefore abrasion is inevitably caused as the recording medium is used repeatedly. The magnetic head is clogged.

Therefore, as one of the measures for preventing the clogging, as shown in FIG. 10, a substantially L-shaped notch 1 is formed at one end of the sliding surface a of the head chip of the magnetic head.
It has been proposed to form 15 and has a great effect.

As a method of manufacturing the above-mentioned magnetic head, first, as shown in FIG. 11, two tracks made of ferrite or the like are used to form a track width regulating groove 111 and a winding groove 11, respectively.
2 and the glass groove 113 are processed and formed into core block halves 101 and 102, and the pair of magnetic core block halves 101 and 102 are butted against each other through a gap material, and melted into the glass groove 113 by fusion bonding. The magnetic core block 103 is manufactured by pouring glass and joining and integrating them.

Next, as shown in FIG. 12, this magnetic core block 103 is installed in a jig and a cylindrical grinder is used to
While swinging the magnetic core block 103, cylindrical grinding is performed so that the ground surface 114 has a substantially cylindrical shape.

Then, as shown in FIG. 13, one end of the grinding surface 114 subjected to the cylindrical grinding process, that is, the grinding surface 114 of the magnetic core block 102 slidingly contacting the rear side of the video tape which is the magnetic recording medium in this case. A strip-shaped notch 115 is formed parallel to the magnetic gap g so that the vertical cross-section has a substantially L-shape at one end, and then a guide groove 116 for positioning the winding material is formed. The contact width is processed to secure the contact width for the video tape.

Thereafter, as shown in FIG. 10, the magnetic core block 103 is cut out for each chip width, and the head chip 1 composed of a pair of magnetic core halves 121 and 122.
To form 04. Next, the head chip 104 thus manufactured is adhered and fixed to a head substrate (head base), and the grinding surface 111 of the head chip 104 is tape-wrapped with a lapping tape and polished to a magnetic recording medium sliding surface. a is formed. Then, an extremely fine copper wire is wound a predetermined number of times around the winding groove 112 and the guide groove 116 to perform winding, and the magnetic head is completed through post-processes such as inspection for each item.

[0008]

As described above, when the above magnetic head is manufactured, it is sufficient to slide the magnetic recording medium in a rough finish state only by subjecting the grinding surface 114 to cylindrical grinding. It is not a surface, and it is necessary to apply tape wrap after cylindrical grinding to finish. However, since the head chip 104 is formed with the cutout portion 115, each ground surface 1 of the magnetic core halves 121 and 122 is formed.
14 has an asymmetrical shape. Therefore, the sliding surface of the magnetic recording medium does not have a uniform cylindrical shape when the tape is wrapped, and particularly in the vicinity of the notch 115, that is, the magnetic core half body 12.
The radius of curvature near the edge of 2 tends to be small.

As described above, in the magnetic head manufactured through the above-mentioned steps, the sliding surface of the magnetic recording medium is slightly asymmetrical or the entire sliding surface of the magnetic recording medium is incompletely cylindrical. Therefore, there is a problem in that good contact with the magnetic recording medium is not maintained and the contact characteristics are deteriorated, and the output signal is significantly deteriorated due to spacing loss.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent clogging that tends to occur each time sliding contact with a magnetic recording medium is repeated. For a magnetic head having a notch at one end of the moving surface, it is possible to easily obtain a highly accurate and uniform cylindrical shape of the sliding surface of the magnetic recording medium of the magnetic head. It is an object of the present invention to provide a method of manufacturing a magnetic head in which the contact characteristics of the surface with respect to the magnetic recording medium are improved and the output is improved to significantly improve the reliability of the product.

[0011]

The object of the present invention is to provide a notch at one end of a sliding surface of a magnetic recording medium in order to prevent clogging that tends to occur each time the sliding contact with the magnetic recording medium is repeated. A method of manufacturing a magnetic head provided with a section.

According to the present invention, a step of cylindrically grinding a ground surface of a magnetic core block having a plurality of magnetic gaps formed by fusing a pair of magnetic core block halves, and sliding the magnetic recording medium on the rear side. A step of forming a band-shaped groove portion in parallel with the magnetic gap on the ground surface of the magnetic core block halves in contact; a step of cutting the magnetic core block into each head chip and adhering the head chip to a head substrate; By performing a step of polishing the grinding surface to form a magnetic recording medium sliding surface and a step of removing the side end portion formed on the head chip by providing the groove portion to form a cutout portion, The above-mentioned magnetic head is manufactured.

At this time, it is desirable that the groove of the magnetic core block half has a substantially V-shaped vertical cross section. Further, the vertical sectional shape may be formed in a slit shape or the like.

[0014]

In the method of manufacturing a magnetic head according to the present invention, of the pair of magnetic core block halves, the ground surface of the magnetic core block halves slidingly contacting the magnetic recording medium on the rear side is parallel to the magnetic gap. A band-shaped groove is formed, a magnetic core block is cut into each head chip, the head chip is chip-bonded to a head substrate, and then a grinding surface of the head chip is polished to form a sliding surface of a magnetic recording medium. In this case, when the grinding surface of the head chip is lapped and polished, only grooves are formed in the grinding surface, and the grinding surface of each magnetic core half of the head chip is considered to be substantially symmetrical. be able to. Therefore,
Even if the grinding surface is lapped, the polishing is not biased, and the entire grinding surface is uniformly processed into a cylindrical shape.

By providing the groove after the wrapping and removing the side end formed on the head chip to form a notch, clogging may occur when sliding on the magnetic recording medium. Thus, a magnetic head having a sliding surface of the magnetic recording medium formed into a substantially perfect cylindrical shape is manufactured.

At this time, by forming the vertical cross-sectional shape of the groove of the magnetic core block half body into a substantially V shape,
When removing the side edge of each cut out head chip,
The desired notch is formed easily and reliably.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method of manufacturing a magnetic head according to the present invention will be described below with reference to the drawings.

In the magnetic head manufactured in this embodiment, a notch is formed at one end of the sliding surface of the magnetic recording medium in order to prevent clogging that tends to occur each time the sliding contact with the magnetic tape as the magnetic recording medium is repeated. Parts are provided.

The head chip 4 of the magnetic head is shown in FIG.
As shown in, the pair of magnetic core halves 4a and 4b are joined and integrated by a fused glass via a gap material to form a magnetic gap g. The head chip 4 is provided with a track width regulation groove 11, a winding groove 12 for winding, a glass groove 13 for pouring the molten fused glass, and a guide groove 14 for positioning the winding material. Has been.

In particular, the magnetic core half 4b has a substantially L-shaped cutout 1 at one end of the sliding surface a of the magnetic recording medium.
5 is formed. The head chip 4 is installed on a head base described later to form a magnetic head, and when the video tape slides on the magnetic recording medium sliding surface a of the head chip 4 in the VTR, the magnetic core half 4 is used.
The sliding surface a of the magnetic recording medium a is first in sliding contact, and then the sliding surface a of the magnetic core half 4 is in sliding contact. Therefore, even if the magnetic recording medium sliding surface a is worn as it is used, the scraped head material does not remain on the magnetic recording medium sliding surface a because it is removed from the cutout portion 15 to the outside. The magnetic head will not be clogged.

In order to manufacture the above magnetic head, first, the track width regulating groove 11, the winding groove 12, and the glass groove 13 are machined in two substrates made of ferrite or the like to form each magnetic core block half body 1. , 2 and then, as shown in FIG. 2, the pair of magnetic core block halves 1, 2,
Are abutted against each other via a gap material, and the fused glass melt is poured into the glass groove 13 to join and integrate them to manufacture the magnetic core block 3.

Next, as shown in FIG. 3, a cylindrical grinding machine is set so that the magnetic gap g is in a cylindrical shape (R shape) having an apex with respect to the grinding surface 3a of the upper surface of the magnetic core block 3. Cylindrical grinding is performed using. At this time, the grinding surface 3a is ground into a substantially uniform cylindrical shape while applying a required swing to the magnetic core block 3. After that, the guide groove 14 is formed.

Then, as shown in FIG. 4, of the magnetic core blocks 3 subjected to cylindrical grinding, near one end of the ground surface 3a on the core block half body 2 side, here, for a video tape which is a magnetic recording medium. A strip-shaped groove 16 is formed in parallel with the magnetic gap g in the vicinity of one end of the ground surface 3a of the magnetic core block half body 2 which is a magnetic core half body that slides in contact with the rear side. The vertical cross section of the groove 16 is substantially V-shaped,
It is formed to have a base angle θ that is a predetermined acute angle. At this time, by forming the groove portion 16, the side end portion 2a is formed at the end portion of the magnetic core block half body 2. Subsequently, a guide groove 14 for positioning the winding material is formed, and a contact width process is performed to secure a contact width for the video tape.

Thereafter, as shown in FIG. 5, the magnetic core block 3 is cut out for each chip width to form a head chip 4 composed of a pair of magnetic core halves 4a and 4b. Next, as shown in FIG. 6, the head chip 4 thus produced is bonded and fixed to a head substrate (head base) 5, and a tape wrap is applied to the grinding surface 3a of the head chip 4 using a predetermined wrapping tape. It is applied and polished to form a sliding surface a of the magnetic recording medium.

Then, as shown in FIG. 7, the magnetic core half body 4b formed by cutting out the magnetic core half body block 2 is formed.
The side end 2a is removed by using a predetermined jig to form a substantially L-shaped notch 15 at one end of the magnetic core half 4b.

Thereafter, as shown in FIG. 8, a predetermined number of fine copper wires are wound in the winding groove 12 and the guide groove 14 of the head chip 4 fixed to the head base 5 to form a winding,
The magnetic head is completed through post-processes such as inspection for each item. Then, the head substrate 5 on which the head chip 4 is installed is mounted on a rotary drum to form a rotary magnetic head device.

As described above, in this embodiment, of the pair of magnetic core block halves 1 and 2, the magnetic gap is formed on the grinding surface 3a of the magnetic core block half 2 which is in sliding contact with the video tape on the rear side. After forming the band-shaped groove 16 parallel to g, cutting out the magnetic core block 3 into each head chip 4 and chip-adhering the head chip 4 to the head substrate, the ground surface 3a of the head chip 4 is polished to make it magnetic. The recording medium sliding surface a is formed. In this case, when the grinding surface 3a of the head chip is lapped and polished, only the groove 16 is formed in the grinding surface 3a, and the grinding surface of each of the magnetic core halves 4a and 4b of the head chip 4 is ground. Three
a can be regarded as a substantially symmetrical shape. Therefore,
Even if lapping is applied to the grinding surface 3a, uneven polishing does not occur, and the grinding surface 3a is uniformly processed into a cylindrical shape.

After lapping, the side end 2a formed by the groove 16 provided in the magnetic core half 4b having the groove 16 of the head chip 4 is pressed by using a predetermined jig. By removing the cutout portion 15 to form a cutout portion 15, a magnetic head having a magnetic recording medium sliding surface a formed as a substantially complete cylindrical shape without causing clogging when sliding with a video tape is obtained. Will be created.

At this time, the vertical section of the groove 16 of the magnetic core block half body is formed into a substantially V shape so that the side end 2a of each cut out head chip can be easily and easily removed. The desired notch 15 is surely formed.

Here, one experimental example will be described.
In this experiment, each magnetic recording medium was prepared by using the magnetic head (Sample A) manufactured in the above-mentioned embodiment and the magnetic head (Sample B) manufactured by the above-mentioned conventional manufacturing method as a comparative example with respect to this magnetic head. The shape of the sliding surface a was investigated.

In this experiment, as shown in FIG.
For each magnetic recording medium sliding surface a, the radius of curvature at the magnetic gap g is R0, and the radius of curvature at a position 100 μm away from the magnetic gap g of the magnetic core half on the side having no notch is R1, the side having the notch The radius of curvature of the magnetic core half body at a position separated by 100 μm from the magnetic gap g was R2. The experimental results are shown in Table 1 below. In Table 1, an experiment was conducted using a predetermined number of samples, and the average value was M, the variance value was σ, and the minimum value was m.
Shown as in.

[0032]

[Table 1]

As is clear from this result, in the sample B, a difference of 2 mm occurs between R1 and R2, whereas in the sample A, the difference between R1 and R2 is 0.3 m.
The value was about m, which was almost negligible. Further, in the sample A, the dispersion value σ, that is, the variation was reduced to about half as compared with the sample B. Further, regarding the degree of wear of the sliding surface a of the magnetic recording medium, Sample A
Shows a result improved by about 30% as compared with Sample B.

[0034]

As is apparent from the above description, according to the method of manufacturing a magnetic head of the present invention, it is possible to prevent clogging that tends to occur each time the sliding contact with the magnetic recording medium is repeated, and to achieve high precision. It is possible to easily obtain a uniform cylindrical shape of the magnetic recording medium sliding surface of the magnetic head, and to improve the output by improving the contact characteristics of the magnetic recording medium sliding surface against the magnetic recording medium. The reliability can be greatly improved.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a head chip of a magnetic head manufactured in this example.

FIG. 2 is a perspective view schematically showing a magnetic core block manufactured by joining and integrating the core block halves.

FIG. 3 is a perspective view schematically showing a state where cylindrical grinding is performed on a grinding surface of an upper surface of a magnetic core block.

FIG. 4 is a perspective view schematically showing a state where a band-shaped groove portion or the like is formed on the grinding surface.

FIG. 5 is a perspective view schematically showing the cut out head chips.

FIG. 6 is a side view schematically showing how a head chip is adhesively fixed to a head substrate.

FIG. 7 is a side view schematically showing a state in which a cutout portion is formed at one end of a magnetic core half body.

FIG. 8 is a perspective view schematically showing a state in which a winding or the like is applied to the head chip.

FIG. 9 is a schematic diagram showing each radius of curvature of a sliding surface of a magnetic recording medium.

FIG. 10 is a perspective view showing a head chip having a notch formed at one end of a sliding surface.

FIG. 11 is a perspective view schematically showing a magnetic core block manufactured by joining and integrating the core block halves.

FIG. 12 is a perspective view schematically showing how cylindrical grinding is performed on the ground surface of the upper surface of the magnetic core block.

FIG. 13 is a perspective view schematically showing a band-shaped notch formed in parallel to the magnetic gap so that a vertical cross-sectional shape is substantially L-shaped on the ground surface of the upper surface of the magnetic core block.

[Explanation of symbols]

 1, 2 magnetic core block half body 3 magnetic core block 3a ground surface 4 head chips 4a, 4b magnetic core half body 15 notch portion 16 groove portion

Claims (2)

[Claims] 1. A step of cylindrically grinding a ground surface of a magnetic core block in which a pair of magnetic core block halves are fused to form a plurality of magnetic gaps; Forming a band-shaped groove on the ground surface of the core block half parallel to the magnetic gap; cutting the magnetic core block into each head chip and bonding the head chip to a head substrate; And a step of forming a sliding surface of the magnetic recording medium by polishing, and a step of deleting a side end portion formed on the head chip by providing the groove portion to form a cutout portion. Magnetic head manufacturing method. 2. The method of manufacturing a magnetic head according to claim 1, wherein the groove has a substantially V-shaped vertical cross-sectional shape.