JPH02143902A - Manufacture of magnetic head chip - Google Patents

Abstract

PURPOSE:To grind a magnetic head chip without causing chipping at the edge of a track groove by grinding the surface of a core block to be joined with another core block in the direction perpendicular to the track grooves by using a grinder. CONSTITUTION:After, for example, core blocks 1 are stuck to four places at the peripheral edge of a grinding face plate 5 equally divided into four parts, with the surface 2 of each block 1 to be joined with another block upward, a grinder 6 is lowered while it is rotated and the blocks 1 are ground with a ring-like grinder section 63 at the peripheral margin on the bottom surface of grinder 6 so that the surfaces 2 of the blocks 1 can be aligned in the same plane. When the grinder 6 is horizontally lowered against the grinding face plate 5 while the grinder 6 is rotated by means of an external driving mechanism, track grooves 3 formed in the surface 2 of each block 1 are ground in the same plane in the direction perpendicular to the lower end grinder section 61 of the grinder 6. Therefore, the core blocks 1 can be ground, while hardly producing chipping at the edge 31 of the track groove 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic head chip used in a VTR, etc., and particularly relates to an improvement in the process of grinding the joint surface of a core block.

[Prior Art] This type of magnetic head chip is generally manufactured by the following method. First, track grooves are formed in a core block made of a ferromagnetic material such as -1 ferrite.

■ Form each groove, and as shown in FIG. 4, place the surface to be joined (gap forming surface) 103 of each of the plurality of core blocks 102 on which the track grooves 101 are formed on the grinding surface plate 100 on the upper side. Glue and fix the grinding surface plate 10.
A grinder F1 is mounted on the rotary table 104, and each surface 103 to be joined of the core block 102 is ground by a rotary grinding wheel 105 that can be moved up and down. And grinding river surface board 1
00 is removed from the rotary table and pressed against a mirror polishing table (not shown), and the surfaces 103 of each core block 102 to be joined are mirror polished using diamond abrasive grains or the like. Next, the core blocks 1 of the set are joined to each other.
A gap spacer film of a non-magnetic material is formed on one or both of the surfaces 103 to be bonded.
With the three core blocks butted against each other, (2) the glass rod placed in the groove is melted and poured by heating and fused to join both core blocks. Then, a magnetic head chip is manufactured by curve-polishing the top surface of the head having a gap in this core block assembly and slicing it at a predetermined azimuth angle at each track groove 101.

[Problems to be Solved by the Invention] However, when manufacturing a magnetic helad tip using the above method, the following problems occurred in the process of grinding the surface 103 to be joined of the core block 102. That is, when the joint surface 103 of the core block 102 attached to the grinding surface 100 on the rotating table 104 is rotated and the rotating grinding wheel 105 grinds, the grinding direction of each core block 102 is randomly generated. As the rotary table 104 rotates, the grinding direction changes.

For example, in the state shown in FIG.
2 (102a) where the joining surface 103 is the track groove 10
1, and the surface 103 of the core block 102 (102b) to be joined is ground in a direction substantially parallel to the track grooves 101. If the polishing direction is random in this way, as shown in FIG. 5, when the track grooves 101 are polished in a direction substantially parallel to each other, large defects (hereinafter referred to as chipping) occur at the groove edges of each track groove 101. 106 is produced, and the chipping amount reaches an average of about 38 μm. If such large chipping occurs, a considerable amount of polishing will be required in the mirror polishing process in the subsequent process, which will lengthen the polishing time, and will also change the width of the track grooves 101, which will affect the final magnetic field produced. There is a problem in that the dimensional error in the track width of the Herad chip increases. Note that the V-groove formed on the joint surface 103 of the core block 102 is ground in a substantially parallel direction by the grinding wheel 105 during the grinding process, but since it forms an inclined surface with the joint surface, chipping is less likely to occur than in the past.

[Means for Solving ff, d] In order to solve the above-mentioned problems, the method for manufacturing a magnetic helad tip of the present invention includes grinding a surface to be joined of a core block in which a track groove is formed with a grinding wheel perpendicular to the track groove. It is characterized by including a step of grinding in the direction of

[Function] As in the present invention, when the surface to be joined of the core block is ground in the direction perpendicular to the track groove using a grinding wheel,
It has been experimentally confirmed that almost no chipping occurs on the groove edges of the track grooves, and that the amount of chipping can be suppressed to about 7 μm on average.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 3 are explanatory diagrams of a method of manufacturing a magnetic helad tip according to an embodiment of the present invention, respectively. FIG. 1 shows a pair of core blocks 1. made of a ferromagnetic material such as polycrystalline Mn--Zn ferrite, which will become a magnetic head chip manufactured by the manufacturing method of the present invention. 1, and a plurality of track grooves 3 are cut at predetermined intervals on the joining surfaces 2, 2 where a gap is formed, and a V-shaped groove 4 is formed perpendicular to each track groove 3. .

The core block 1 in which the track grooves 3 have been formed is then ground so that the joining surfaces 2 of each core block 1 are flush with each other. This grinding process, as shown in Figure 2,
The grinding process is carried out using a fixed disk-shaped grinding wheel 5 and a grinding wheel 6 having approximately the same outer diameter as the grinding wheel 5 and being movable up and down in a horizontal state. The grinding wheel 6 includes a base portion 62 that rotates by a rotating shaft 61 connected to an external drive mechanism (not shown), and a grinding wheel portion 63 provided at the periphery of the lower end of the base portion 62 . This grindstone part 63 has a ring shape with a width slightly wider than the width of the joint surface 2 of each core block l, and is, for example, a ceramic bond diamond grindstone #60.
0 or the like may be used, and if necessary, grooves may be formed to allow the shavings to escape.

In the above-mentioned grinding process, the surface 2 to be joined of each core block l is placed on the upper side, and in the embodiment, the grinding surface plate 5 is divided into four equal parts and fixed at four places on the periphery, and then the above-mentioned grinding wheel 6 is rotated. Then, the core blocks 1 are ground by the ring-shaped grindstone portion 63 at the lower end periphery so that the joint surfaces 2 of each core block 1 are all flush with each other. In this way, when the grinding wheel 6 is rotated by the external drive mechanism and lowered horizontally toward the grinding surface u5, the track grooves 3 formed on the joining surface 2 of each core block l are aligned with the grinding wheel 6. It is ground flush in a direction perpendicular to the lower end grindstone portion 61 of. If you grind in this condition,
Groove &t31 of each track groove 3 can be ground with almost no chipping.

For example, when grinding is performed under conditions such as the rotation speed of the grinding wheel 6 being 280 Orpm and the grinding feed rate being 10 μm/min, the amount of chipping that occurs on the groove edge 31 of each track groove 3 can be kept to an extremely small average of about 7 μm. was confirmed.

When the surfaces 2 to be joined of each core block l are all ground flush and the groove edges 31 of each track groove 3 are ground with almost no chipping, then as shown in FIG. 3, With each core block l stuck on the grinding plate 5, it is turned over and a rotating shaft 51 that can freely move up and down is attached to the back side, and the joint surface 2 of each core block 1 is attached.
is pressed onto the mirror polishing table 7, and the surface 2 to be joined of each core block l is further polished with diamond abrasive grains etc., chippings formed in each track groove 3 are scraped off, and each surface 2 to be joined is polished to a mirror surface. Finish it. At this time, since almost no chipping occurs on the groove edge 31 of each track groove 3, the chipping can be removed with a small amount of polishing M@, there is almost no worry that the width of each track groove 3 will change, and moreover, it can be mirror-finished in a short time. Be able to polish.

Wet edges 31 of each track groove 3 are polished by mirror polishing the surface 2 to be joined.
Core block 1 from which chippings formed in
A set of core blocks 1. to be joined together. A non-magnetic gap spacer film is formed on one or both of the surfaces 2 to be bonded.
With the two pieces butted against each other, ■ groove! The placed glass rods are melted and poured by heating and fused, and both core blocks 1
゜1 is integrally joined. Then, the top surface of the head having the gap of this core block assembly is polished into a curved surface and sliced at a predetermined azimuth angle at each track groove 3, thereby producing an m% head chip.

The magnetic head chip manufactured in this way has almost no change in the width of the track groove 3 of each core block l, and thus becomes a magnetic head chip with almost no dimensional error in track width.

In the above embodiment, the ring-shaped grinding wheel 6 is rotated to move the joint surface of the core block 1 attached to the upper periphery of the disk-shaped grinding plate 5 in a direction perpendicular to the track groove 3. Although the method of grinding has been explained, the present invention is not limited to this. Both grinding plates are made into long plates, and the grinding plates are cut in the front and back or left and right so as to be perpendicular to the track groove 3 of the core block l stuck on the grinding plate. Grinding may be performed by moving the grinding wheel in the direction. In addition, in the groove 4 formed on the joint surface 2 of the core block 1,
In the grinding process, the grinding wheel 6 grinds in a substantially parallel direction, but since a joint surface and an inclined surface are formed, chipping is less likely to occur than in the past.

[Effects of the Invention] As is clear from the above description, in the method for manufacturing a magnetic head of the present invention, during the grinding process, the grinding wheel does not cause chipping of the surface to be joined of the core block, mostly at the groove edges of the track grooves. Since the grinding can be done without any grinding, the amount of polishing is reduced in the mirror polishing process after grinding, and the polishing can be done in a short time.
The width of the track groove also hardly changes, and the effect is that variations in the track width of the finally manufactured magnetic held chip are less likely to occur.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams of a method for manufacturing a magnetic helad tip according to an example of the present invention, in which 11ffl is a perspective view of a core block, and FIG. 2 is a partially broken perspective view showing the grinding process. 3 are side views showing the mirror polishing process, FIG. 4 is a top view showing the conventional grinding process, and FIG. 5 is a top view of the core block. l... Core block, 2... Surface to be joined, 3... Track groove, 6... Grinding wheel. Patent application Kansai NEC Co., Ltd. Figure 2 Figure 3

Claims (1)

[Claims] (1) A method for manufacturing a magnetic head chip, which includes the step of grinding a surface to be joined of a core block in which track grooves are formed using a grinding wheel in a direction perpendicular to the track grooves.