JPS5819719A - Production of digital magnetic head - Google Patents

Abstract

PURPOSE:To obtain a tunnel erasion type magnetic head of high accuracy, by providing erasing gaps at both sides of a reading/writing gap and unifying a nonmagnetic material part and a magnetic material part at their opposite position and via a nonmagnetic spacer. CONSTITUTION:A U bar 10 and I bar 11 made of a ferromagnetic material are unified into a body via a nonmagnetic film 14 and a nonmagnetic gap 12. These bars 10 and 11 are used as a reading/writing (R/W) bond bar 13a and an erasing (E) bond bar 13b respectively. These bars 13a and 13b are joined to obtain a core 20 via a nonmagnetic spacer 15. The nonmagnetic part and the magnetic part of an R/W gap 21 and an E gap 22 of the core 20 are set opposite to each other. Thus such preformable core 20 is formed to a highly accurate tunnel erasion type digital magnetic head which is suited to a mass production with reduced variance of assembling accuracy.

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 employed in floppy disk drives generally have a structure in which erase gaps are provided on both sides of the read/write gap of the core to ensure data (media) compatibility. There are two types of magnetic heads of this type: tunnel erase type and straddle erase type.
When writing data on one track, the writing width is trimmed to prevent interference with data on adjacent tracks.

By the way, as shown in FIG. 1, a conventional tunnel erase type magnetic head is made by sandwiching 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 the L geomagnetic core 4 and the I It consists of a type magnetic core 5 and a non-magnetic 7-shaped part 6 bonded to the I type magnetic core 5, and the central read/write core layer 1 is connected to the outer erase core layer 2.
(see C in the same figure),
As mentioned above, they are joined and integrated.

However, in this manufacturing method, an extremely thin reading/writing core layer 1 and an erasing core layer 2 are first created, then lap polishing is performed to achieve track width accuracy, each of them is aligned, and many layers are created. 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 layer conventionally considered suitable is 13 mils (13 mils) for the read/write core layer 1.
The erase core layer 2 has a thickness of about 6 mils (about 0.45 mm).

Also, devices half the size of these are already in use. Since each core layer 1.2 is extremely thin, its mechanical strength is extremely weak and must be handled carefully and carefully. Therefore, this method is not very suitable for mass production, and there are large variations in assembly accuracy. .

The purpose of the present invention is to solve the problems inherent in the conventional technology, and to develop a tunnel erase type 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 digital magnetic 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 a ferromagnetic material (for example, ferrite) are joined together via a nonmagnetic gap 12 to form a bond bar.

As the forming phase #1 of the nonmagnetic gap 12, a sputtered film of titanium foil, silicon dioxide, glass, or the like is used.

A set of two such bondpers is prepared, one of which is used for reading/writing (hereinafter abbreviated as RAW) bondper 13a.
1. Bond par for erasing (hereinafter abbreviated as E) on the other side.
It is called 3b.

Next, as shown in Figure B, apply R/AN bond par 1 to each of R/W bond par +3a and E bond par +3b.
A plurality of grooves are arranged in parallel from the ever side to the U bar side so that the pitch is twice that of E bond par + 3b, and the nonmagnetic phase 14 is buried in the grooves. 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 protruding strip should match the width of the R/W + - rack, and the groove width should be equal to twice the width of the E track. On the E bond bar side, protrusions whose widths match the E track width, and grooves whose groove widths match the R/W+-rack width and those corresponding to the above α are arranged alternately. Here, α may be a width slightly wider than the cutting allowance. but.

If α is made to match the R/W + - rack width, the groove machining of E bond par + 3b will be completely as shown in Fig. 2.
Since grooves can be machined with the same width, such an example will be described, but the groove width may be changed to cross FJ:. In either case, it is important that the groove pitch of the R/W bond bar +3a is twice the groove pitch of the E bond par +3b. 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 pars 13a and +3b obtained in this manner are bonded and integrated via the non-magnetic spacer 15 so that the I-bar portions of both are opposed to each other (see C in the same figure). In that case, R/W bond par +3a
Position the magnetic material part of the E-bond par 13b so that it collides with the non-magnetic material part of the E-bond par 13b having the same width. In this example, all the non-magnetic 4'A parts of the E-bond par 131) were made to have the same width, so in this case, the non-magnetic material part and the magnetic material part of both parts of the It is sufficient to locate it. The non-magnetic spacer 15 may be, for example, a sputtered film of silicon dioxide or glass, a thin plate of glass, or a titanium foil.

Next, as shown by the imaginary line in Figure C, it is glued into a body.
1. Rear notch processing is performed on the bar block. (Rear-1
refers to the part on the opposite side to the sliding surface of the metal ′γ (magnetic recording medium). In this example, the R/W bond bar side is cut from the rear surface to the front. The E bond bar side is cut from the rear surface to the center plane flE.
teI] Reference fit, i).

After forming the rear notch, square 1 of the R/W bond bar 13a
If you shred 1 body in the center of the 1st position, you can get 20 cores by using the R/W core and E core as shown in 1.11 in the same figure IC. . 7
Is it indicated by No. 1 21? R/W gear knob, No. 22
What is shown is the E gap.

It is. The R/W core and the E core are each wound with a dedicated coil, and the R/W core in particular is made into a closed magnetic circuit with a bank bar, but these are the same as in the case of conventionally known magnetic heads, so they are not shown in the diagram. Omitted.

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

The present invention has the advantage that the relative positional relationship between the J5 rack and the E track can be arbitrarily selected.

The situation is shown in Figure 4. That is, R/W bond 7<
- The groove width of the E-bond bar in the part facing the magnetic material part of the R/W) should be narrower than the rack width (the groove pitch of the R/W bond bar should be twice the pitch of the E-bond bar). ), the R/W track width can be made narrower than the inner interval of the E gap. This is achieved by the present invention. In the conventional tunnel erase, it was only possible to perform rimming due to the fringe effect of the erase tracks on both sides, but according to the above embodiment, the write track width can be more actively determined by the interval within the erase. Optimal layering becomes possible. In other words, it would be possible to increase the off-track margin by taking into consideration the expansion coefficient of the media, etc.

Still another embodiment of the invention is shown in FIGS. 5A and 5H. They are shown as corresponding figures in FIG. 2B, EK. In this embodiment, the bond bar has a plurality of grooves extending from the 1-bar side to the U-bar side, and grooves are made and pressurized on both sides of the metal slide in the direction perpendicular to the grooves, and a non-magnetic phase 14 is buried in the grooves. Sea urchin/ζ is a sea urchin. This processing is performed on both the R/W hardware and the E bond bar.

Below, by following the same procedure as in Figure 2, Figure 5B is created.
It is possible to obtain a preformed core as shown in FIG. The obtained core has almost the same structure as the conventional one,
In cases where leakage flux is a problem, 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, suitable for mass production, and has excellent mechanical strength that can be obtained when the R/W and E are preformed. The R/W track width is R/W dicing pitch, the recording width is still -r, the dicing groove width is large, and the erase track width is E dicing pitch. Since each is determined individually, it is possible to obtain products with high precision regardless of cutting dimensions, and with less variation in dimensions without lap polishing, and it is possible to reduce loss by 1. The practical effect is that It is.

[Brief explanation of the drawing]

Figure 1A, l'3. C is it! -+Explanatory diagram of the prior art; Figure 2 is a process diagram showing an embodiment of the method of the present invention; Figure 3 is a plan view of the head manufactured by method 1;
FIG. 4 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... Non-magnetic gap, +3a... R/W bond bar, +3b... E bond bar, 14... Non-magnetic material, 15- Non-magnetic spacer, 2
0...core, 21...R/w gap, 2?・E gap. Patent Applicant: Fuji Electrochemical Co., Ltd.
Tanema Shigemi
Tomoyuki Araki Assistant ear 3 figure F5 Figure 4 2'1 22 figure

Claims (1)

[Claims] 1. For each of the two bond bars, which are made by bonding a U-bar made of ferromagnetic material and an Ever, through a non-magnetic gap, from the Ever side to the U-bar side so that one has twice the pitch of the other. A plurality of grooves are arranged in parallel, and a non-magnetic material is buried in the valley grooves, and the non-magnetic material part and the magnetic material part of a part of the two bond bars are substantially opposed to each other. After bonding and integrating via a non-magnetic spacer, the rear part is cut and shredded at the position where the non-magnetic material is embedded in a portion of both bond bars to obtain a preformed core for reading/writing and erasing. A method for manufacturing a tunnel erase digital magnetic head, characterized in that: