JPS634243B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a tunnel erase type digital magnetic head.

For example, magnetic heads used in floppy disk drives generally have an erase gap on both sides of a core read/write gap to ensure data (media) compatibility. There are two types of magnetic heads of this type: tunnel erase type and straddle erase type, but in either case, when writing data to one track, the write width is trimmed and data is transferred to the adjacent track. It is designed to prevent interference.

By the way, as shown in FIG. 1, a conventional tunnel erase type magnetic head consists of a sander circuit consisting of three similar layers: a read/write core layer 1 located in the center and erase core layers 2 located on both sides of the read/write core layer 1. It was manufactured through a process of joining and integrating it into the structure. That is, each core layer 1, 2 has the same shape (however, the thickness may be different), and is connected to an L-shaped magnetic core 4 and I through a gap 3, as shown in FIG. It consists of a type magnetic core 5 and a non-magnetic L-shaped member 6 adhered to the I-type magnetic core 5, and the central read/write core layer 1 is arranged so as to face the outer erase core layer 2 in the opposite direction. (see C in the same figure) and are joined and integrated as described above.

However, in such a manufacturing method, an extremely thin read/write core layer 1 and erase core layer 2 are first created, then lap polishing is performed to obtain track width accuracy, each of them is aligned, and if necessary, In the end, it becomes necessary to align the five sheets in a set so that the outrigger 7 is located outside the erase core layer 2, and to bond and integrate them, which is a very complicated operation. Incidentally, the thickness of the core layer that is conventionally considered to be suitable is 13 for the read/write core layer 1.
mil (approximately 0.33 mm), and the erase core layer 2 is 6 mil (approximately 0.15 mm). It is also likely that a device half the size of these will be used. Since the core layers 1 and 2 are extremely thin, their mechanical strength is extremely weak and they must be handled carefully and carefully, and therefore this method is not very suitable for mass production.
There was also large variation in assembly accuracy.

The purpose of the present invention is to solve the problems of the prior art, and to develop a tunnel erase type digital magnetism that is easy to assemble, suitable for mass production, has little variation in assembly accuracy, and can be made highly accurate. An object of the present invention is to provide a method for manufacturing a head.

Hereinafter, the present invention will be explained in detail based on the drawings.
FIG. 2 is a process explanatory diagram showing an embodiment of the present invention. First, as shown in FIG. 2A, a U bar 10 and an I bar 11 made of ferromagnetic material (for example, ferrite) are shown.
are joined together via a non-magnetic gap 12,
Create a bond bar. As the material for forming the non-magnetic gap 12, a sputtered film of titanium foil, silicon dioxide, glass, or the like is used. A set of two such bond bars is prepared, one of which is used for reading/writing (hereinafter abbreviated as R/W) bond bar 13.
a, and the other is called an erase (hereinafter abbreviated as E) bond bar 13b.

Next, as shown in FIG. B, each of the R/W bond bar 13a and the E bond bar 13b is
Multiple grooves are arranged in parallel from the bar side to the U bar side,
A non-magnetic material 14 is buried in the groove. Groove formation can be performed with high precision using a dicing machine. The groove shape is as follows. On the R/W bond bar side, the width of the protrusion should match the width of the R/W track, and the groove width should be twice the width of the E track. On the E bond bar side, on the other hand, the width of the protrusion is E.
This corresponds to twice the track width, so that the groove width matches the width of the R/W track. As the non-magnetic material 14 to be buried, for example, ceramic such as barium titanate or calcium titanate, or glass can be used. The two bond bars 13a and 13b thus obtained are bonded and integrated via the non-magnetic spacer 15 at a position where the non-magnetic material portion and the magnetic material portion of both I-bar portions face each other. (See Figure C). The non-magnetic spacer 15 may be, for example, a sputtered film of silicon dioxide or glass, or a titanium foil.

Next, as shown by the imaginary line in FIG.
The term "rear" refers to the part on the opposite side to the sliding surface of the media (magnetic recording medium). In this example,
The R/W bond bar side is cut from the rear surface to the front surface, and the E bond bar side is cut from the rear surface to the center surface (see D in the same figure).

After forming the rear notch, the R/W bond bar 13a is shredded at the center of the non-magnetic material embedding position to obtain a core 20 in which an R/W core and an E core are preformed, as shown in FIG. be able to.
The reference numeral 21 indicates the R/W gap, and the reference numeral 22 indicates the E gap.
Each of the R/W core and E core is wound with a dedicated coil, and the R/W core in particular has a closed magnetic path with a back bar, but these are the same as in the case of conventionally known magnetic heads, so illustrations are omitted. do.

Figure 3 shows a view from the media sliding surface side.

According to the present invention, there is an advantage that the relative positional relationship between the R/W track and the E track can be arbitrarily selected. The situation is shown in Figure 4. In other words, if the groove width of the E bond bar is narrower than the R/W track width, and the width of the protrusion is wider than the groove width on the R/W bond bar side (however, the groove pitch of the R/W bond bar and the E bond bar are the same). ), the R/W track width can be made narrower than the inner gap of the E gap.
This is something that can only be achieved by the present invention. In the conventional tunnel erase, it was only possible to perform trimming using the fringe effect from the erase tracks on both sides, but according to the above embodiment, the write track width can be determined more actively based on the interval within the erase, and the writing track width can be optimally determined. Design becomes possible. In other words, the off-track margin can be made larger by taking into consideration the expansion coefficient of the media and the like.

Still another embodiment of the present invention is shown in FIGS. 5A and 5B. They are shown as diagrams corresponding to FIGS. 2B and 2E. In this embodiment, the bond bar has a plurality of grooves extending from the I-bar side to the U-bar side, and grooves are formed on both sides of the media sliding side in a direction perpendicular to the grooves, and the non-magnetic material 14 is buried in the grooves. This is what I did. This process is applied to both the R/W bond bar and the E bond bar. Thereafter, by following the same procedure as in FIG. 2, a preformed core as shown in FIG. 5B can be obtained. The obtained core has a structure substantially similar to that of the conventional core, and in cases where leakage flux becomes a problem, the core of this embodiment is preferable.

Since the present invention is a method for manufacturing a tunnel erase type digital magnetic head configured as described above, it is easy to assemble and suitable for mass production, and has good mechanical strength since the R/W and E are obtained in a preformed state. It is large and easy to handle afterwards.
Since the track width is determined by the R/W dicing pitch and the recording width is determined by the erase dicing groove width, it is possible to obtain products with high precision and little variation in dimensions, which can reduce costs. is large.

[Brief explanation of the drawing]

1A, B, and C are explanatory diagrams of the prior art, FIG. 2 is a process explanatory diagram showing an embodiment of the method of the present invention, FIG. 3 is a plan view of a head manufactured by the method, and FIG. The figure is a plan view of a head obtained by another embodiment, and FIGS. 5A and 5B are partial process explanatory diagrams of still another embodiment. 10...U bar, 11...I bar, 12...Nonmagnetic gap, 13a...R/W bond bar, 1
3b...E bond bar, 14...Nonmagnetic material, 15
...Nonmagnetic spacer, 20...Core, 21...
R/W gap, 22...E gap.

Claims (1)

[Claims] 1 A plurality of grooves extending from the I-bar side to the U-bar side are provided in parallel on each of two bond bars made by bonding a U-bar and an I-bar made of ferromagnetic material via a non-magnetic gap. A non-magnetic material is buried in each groove,
After bonding and integrating the two bond bars through a non-magnetic spacer at a position where the non-magnetic material portion and the magnetic material portion of both I-bar portions are substantially opposed to each other, a rear notch is applied, and one bond bar portion is A method for manufacturing a tunnel erase type digital magnetic head, characterized in that a core is preformed for reading/writing and erasing by cutting into pieces at a position where a non-magnetic material is buried.