JPH0433528Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention relates to a thin film magnetic head having multiple tracks, and is particularly used to process the depth of each track to be uniform in the manufacturing process of the thin film magnetic head. This invention relates to a thin film magnetic head with polishing marks.

(B) Prior Art As polishing marks for a thin film magnetic head having a plurality of tracks, there are, for example, those formed as shown in the enlarged plan views of main parts in FIGS. 3 and 4.

The polishing marks 1 shown in FIG. 3 are provided on the outside of both ends of the core or yoke 2 of the thin film magnetic head. This polishing mark 1
Mark portions 1a to 1e are formed to protrude stepwise in the direction (indicated by arrows) in which the core or yoke 2 is polished. For example, assuming that the mark portion 1e of the polishing mark 1 displayed in this way is located at a predetermined depth,
This polishing mark 1 is polished while being checked one by one, and the polishing process is completed when the tip of the mark portion 1e is scraped off and becomes completely invisible.
In this way, each mark portion 1a~ of the polishing mark 1
Machining is performed so that the depth of each track becomes uniform while checking that the tip of 1e is being gradually scraped off and disappearing as the polishing process progresses.

FIG. 4 shows a triangular polishing mark 11.
They are provided on the outside of both ends of the core or yoke of the thin film magnetic head.
The apex 11a of this triangular polishing mark 11 is set at a predetermined depth, and the polishing mark 11 is being ground away, that is, the triangle is being polished sequentially from the bottom 11b side, and the triangle is gradually becoming smaller. Vertex 1 while checking the going state
Polishing is performed to the point where 1a is no longer visible, and the depth of each track is made uniform.

(c) Problems to be solved by the invention However, in all of the conventional products mentioned above, polishing marks are provided on the outside of both ends of the core or yoke location, so it is difficult to perform the polishing process. In this case, even if both polishing marks are matched, the depth of each track may not be uniform.

That is, as shown in the plan view of FIG. 5, alignment is made with the polishing marks 1, 1 provided on the outside of both ends of the location where the core or yoke 2 is located, and the polishing process is started from the direction of the arrow. This polishing process is performed by mechanical polishing from the position of ○A to the position of ○B of polishing mark 1,
Processing is performed by tape polishing from the next position ○B to the position ○C with a predetermined depth.

However, in this finishing stage by tape polishing, although both ends near the polishing mark 1 are polished to a predetermined depth position, the cores or yokes 2 arranged near the center have slack in the polishing tape. Therefore, there was a risk that the polishing would not be done to a predetermined depth at position ○C, and the polishing state would be, for example, as shown by ○D. Furthermore, even if such a polishing condition occurs, since the polishing marks 1 are provided on both sides, it is difficult to confirm the condition during the polishing process, and there is a drawback that characteristics vary between each track. It was hot.

Furthermore, in addition to the above-mentioned drawback that it is difficult to accurately confirm the polishing mark 1 during polishing because it is provided at both ends, there is also the drawback that it is difficult to read the polishing mark itself.

The object of this invention is to provide a thin film magnetic head provided with abrasive marks that eliminates the drawbacks of the prior art.

(d) Means for solving the problem The thin film magnetic head according to this invention is a thin film magnetic head having a plurality of tracks, in which the core or yoke is formed in a stepped manner, and the lowest step has a predetermined depth. It is characterized by having a polishing mark formed to indicate the position of.

(E) Effect By forming stepped polishing marks on the core or yoke itself, each core or yoke can be polished at a predetermined depth position, eliminating variations in characteristics between each track. I can do it.

(F) Example The first example of the thin film magnetic head according to this invention is as follows.
This will be explained based on the figure and FIG. FIG. 1 is a plan view showing essential parts of the structure of the thin film magnetic head, and FIG. 2 is a side view taken along line A--A in FIG.

When forming the core or yoke 2 in the thin film magnetic head manufacturing process, a portion of the polishing mark 12 is formed on each core or yoke 2 itself. The polishing mark 12 formed on each core or yoke 2 is formed in a stepped shape, and when polishing is performed, first and second steps 12a and 12b are used to check the degree of polishing. , and a third step 12c representing a position of a predetermined depth amount. In this embodiment, the polishing mark 12 is formed in three steps, but this can be increased or decreased as desired.

In the figure, 3 is a coil, 4 is a lower magnetic layer, and 5 is a gap. Further, the dotted line ◯ indicates the position of a predetermined depth amount, that is, the depth is ground down to this position by polishing.

As is clear from the above embodiments, the core or yoke 2 on which the stepped polishing marks 12 are formed is
The bottom step of a thin-film magnetic head with multiple tracks is set to a core length (or yoke length) of a predetermined depth, so by cutting the depth to this position ○, each core or yoke can be made uniform. Can be polished.

(g) Effects of the invention According to the thin film magnetic head of this invention, since step-like polishing marks are formed on the core or yoke itself, the depth can be clarified and the depth of each track can be machined uniformly. can record,
It is possible to improve the reproduction head characteristics and to suppress variations between tracks.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of this invention, with Figure 1 being a plan view and Figure 2 being A of Figure 1.
-A cross-sectional side view. Figures 3 to 5 are
A conventional example is shown in which FIGS. 3 and 4 are enlarged plan views of the main parts, and FIG. 5 is a plan view for explaining the polishing state. 1, 11... Polishing mark, 12... Polishing mark, 12a, 12b, 12c... Step, 2...
... Core or yoke, 3 ... Coil, 4 ... Lower magnetic layer.

Claims (1)

[Scope of utility model registration request] A thin film magnetic head having a plurality of tracks, characterized in that the core or yoke is formed in a step-like manner, and the lowest step has a polishing mark formed to indicate the position of a predetermined depth. magnetic head.