JPS634244B2 - - 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 approximately the same shape (however, the thickness may be different), and is connected to an L-shaped magnetic core 4 through a gap 3 as shown in FIG. It consists of an I-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 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 an erase core layer 2 are first created, then lap polishing is performed to obtain track width accuracy, and each of them is aligned. In this case, it is 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 process. Incidentally, the thickness of the core layers conventionally considered suitable is 13 mils (approximately 0.33 mm) for the read/write core layer 1 and 6 mils (approximately 0.15 mm) for the erase core layer 2. Also, devices half the size of these are already in use. 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
are joined together via a non-magnetic gap 12,
Create a bond bar. As the material for forming the non-magnetic gap 12, titanium foil, silicon dioxide, a sputtered film of glass, etc. are 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 one is called an erase (hereinafter abbreviated as E) bond bar 13b.

Next, as shown in FIG. B, the R/W bond bar 13a and the E bond bar 13b are each
Bond bar 13a is better than E bond bar 13b.
A plurality of grooves are arranged in parallel from the I-bar side to the U-bar side so as to have double the pitch, and a non-magnetic material is placed in the grooves.
Bury 4. Groove formation can be performed with high precision using a dicing machine. For example, the groove shape is as follows. On the R/W bond bar side, the width of the protrusion matches the width of the R/W track, and the groove width matches E.
It should correspond to twice the width of the track + α.
On the E bond bar side, protrusions whose width matches the E track width, and grooves whose groove width matches the R/W track width and those corresponding to the above α are arranged alternately.
Here, α may be a width slightly wider than the cutting allowance. However, if α is made to match the R/W track width, the groove machining of the E bond bar 13b is
As shown in the figure, all the grooves can be machined with the same width, so such an example has been described, but the groove widths may be alternately changed. In either case, it is important that the groove pitch of the R/W bond bar 13a is twice the groove pitch of the E bond bar 13b. As the non-magnetic material 14 to be buried, for example, ceramic such as barium titanate, calcium titanate, or forsterite, or glass can be used. The two bond bars 13a, 13 thus obtained
b are bonded and integrated via a non-magnetic spacer 15 so that both I-bar portions face each other (see C in the same figure). In that case, R/W bond bar 13a
E-bond bar 13b whose magnetic material part has the same width as that
Position it so that it collides with the non-magnetic material part of. In this embodiment, all the non-magnetic material parts of the E-bond bar 13b have the same width, so in this case, the non-magnetic material part and the magnetic material part of both I-bar parts should be positioned so as to face each other. It is sufficient. The non-magnetic spacer 15 may be, for example, a sputtered film of silicon dioxide or glass, a thin plate of glass, a titanium foil, or the like.

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 in the part facing the magnetic material part of the R/W bond bar is narrower than the R/W track width (however, the groove pitch of the R/W bond bar is twice the groove pitch of the E bond bar). ), 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.
The R/W track width is the R/W dicing pitch.
In addition, since the recording width is determined by the erase dicing groove width and the erase track width is determined by the E dicing pitch, it is possible to obtain products with high precision regardless of cutting dimensions, and with little variation in dimensions without lap polishing, and at low cost. It has great practical effects, such as being able to reduce the amount of damage.

[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. Two bond bars made by bonding a U-bar and an I-bar made of ferromagnetic material through a non-magnetic gap, from the I-bar side to the U-bar side so that one has twice the pitch of the other. A plurality of grooves leading to the I-bar portions are provided in parallel, a non-magnetic material is buried in each groove, and the two bond bars are placed at a position such that the non-magnetic material portion and the magnetic material portion of both I-bar portions are substantially opposed to each other. After bonding and integrating via a non-magnetic spacer, the rear part is notched and the non-magnetic material is shredded at the position where the non-magnetic material is buried in both bond bar parts to obtain a preformed core for reading/writing and erasing. A method for manufacturing a tunnel erase type digital magnetic head characterized by: