JPH059841B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for manufacturing a thin film magnetic head, and in particular to a method that allows the gap depth to be defined accurately.

(b) Prior art Figure 1 shows the basic structure of a thin film magnetic head, in which a lower head core pattern 2 is formed on a substrate 1,
A first insulating layer 3 is formed thereon, a coil pattern 4 is formed on this first insulating layer 3, a second insulating layer 5 is formed, and an upper head core pattern 6 is formed thereon. It is composed of the following.
In the final manufacturing process of such a thin-film magnetic head, it is necessary to polish the tape-contacting surface in the same way as for bulk-type heads (such as video heads). This is because the gap depth cannot be directly observed due to the presence of a protective plate that also serves as a shield and is bonded after pattern formation. Furthermore, thin-film magnetic heads intended for high-density recording require strict gap and depth accuracy, and time-controlled polishing is insufficient. Therefore, as shown in Fig. 2, triangular monitor patterns 7 and 7' are separately formed on both sides of the head core, so that when polishing the surface facing the tape (for example, when polishing up to line A-A'),
By measuring the length l of the part exposed on the polishing surface side, the gap depth can be calculated and the amount of polishing can be controlled. It is formed into a plurality of comb teeth, and when polishing the tape contacting surface side (for example, when polishing along the B-B' line), the gear depth is determined by the number of comb teeth exposed on the polishing surface side, and the amount of polishing is determined. In particular, in the latter case, the amount of polishing (i.e., gap depth) can be known digitally, making it easy to observe from the polished surface, reducing measurement errors, and improving yield. I can do it. still,
Reference numeral 9 indicates a protection plate which also serves as a shield, and 10 indicates an adhesive layer.
However, even in such a case, there is a problem;
Because each comb tooth portion of the monitor pattern that defines the depth length is thin and the film thickness is relatively thick, the tip of each comb tooth portion may become thinner during pattern formation due to lack of resist adhesion. The shape is shown by the solid line in FIG. 4 (that is, the side edges are large), and an error α occurs between the shape and the design shape shown by the dotted line in FIG. 4, making it impossible to accurately define the gap depth.

(c) Purpose of the Invention The present invention has been made in view of the above points, and aims to provide a method for manufacturing a thin film magnetic head that can solve the above-mentioned problems and obtain a desired gap depth with high precision. It is something.

(d) Structure of the Invention That is, in order to achieve the above-mentioned object, the present invention provides a method for constructing a thin-film magnetic head by forming patterns for a head core, a coil, etc. on a substrate, respectively.
A monitor pattern for defining the gap depth is formed on both sides of one or more head cores, and the monitor pattern includes a plurality of comb teeth each having a different depth formed on the side of the head core opposite to the tape facing surface. The gap depth is defined by the number of missing comb teeth in the monitor pattern exposed on the polished surface side during polishing of the surface facing the tape.

(E) Embodiment An embodiment of the present invention will be described below with reference to the drawings. Note that the same drawing numbers are given to the same components as in the prior art, and the explanation thereof will be omitted.

That is, according to the present invention, the monitor patterns 11, 11' having the shape shown in FIG. 5 are formed simultaneously with the formation of the coil pattern by a thin film forming technique such as vapor deposition or sputtering, and by a photoetching technique. The monitor patterns 11, 11' are formed with a plurality of comb teeth _11a1 ... _11a1 '...of different depths on the opposite side of the head core 6 from the tape contacting surface, and are arranged on the same line as the tape contacting surface. The amount of polishing is regulated by the distance from the one side ends _11b , 11b' located at the notches 11c ₁ .

That is, when polishing the tape contacting surface (for example, C-
The remaining gap depth can be determined by counting the number of missing comb teeth of the monitor pattern exposed on the polished surface side through optical observation using an optical microscope.

Further, FIG. 6 shows another embodiment in which the gap depth is measured electrically rather than optically using such a monitor pattern. Specifically, FIG. Teeth 11a ₁ ...
Connection patterns 12, 12' are separately formed to be electrically connected to each other in correspondence with 11a ₁ '. Incidentally, it is desirable for the process to form the connection patterns 12, 12' at the same time as the monitor patterns 11, 11'. In this way, connection pattern 12,1
The gap depth can be determined by checking the electrical continuity between a-bi and a'-b _i ′ (=1, 2,...7) of 2'. For example, a-b ₄ , a' It can be seen that the polishing has progressed to the line D-D' in FIG. 6 in a state where the wire is electrically conductive up to -b ₄ ' and disconnected after a-b ₅ and a'-b ₅ '. still,
Although this electrical measurement method has drawbacks such as the trouble of connecting to the terminal and the difficulty of making minute measurements due to checking immediately before disconnection, etc., the lens system cannot be brought close due to loading the polishing jig, etc., making it difficult to perform optical observation. It is very effective in impossible cases.

(F) Effects of the Invention As described above, according to the present invention, a monitor pattern formed on both sides of one or more head cores has a plurality of monitor patterns having different depths on the side opposite to the tape facing surface of the head core. Since comb teeth are formed and the gap depth is regulated at the base of the comb teeth (i.e., regulated by the distance from the tape facing surface to the base of the comb teeth), Compared to the conventional method, which uses the tip of the comb teeth to define the gap depth, which causes errors with the designed shape due to insufficient adhesion of the resist, it is easier to obtain the desired gap depth.
Depth can be obtained with high accuracy.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing an example of the basic structure of a thin film magnetic head, Figs. A plan view and a sectional view taken along line B-B' of another example of forming a monitor pattern, FIG. 4 is an enlarged view of the main part thereof, and FIGS. A plan view and a sectional view taken along the line C-C', and FIG. 6 is a plan view showing another embodiment. DESCRIPTION OF SYMBOLS 1... Board, 2... Lower head core, 6... Upper head core, 11, 11'... Monitor pattern, 11
₁₁ to 11 ₈ , 11a ₁ ′ to 11a ₈ ′...Comb teeth.

Claims (1)

[Claims] 1. A monitor for defining the gap depth on both sides of one or more head cores when forming a thin film magnetic head by forming patterns for head cores, coils, etc. on a substrate. The monitor pattern includes a plurality of comb teeth having different depths formed on the opposite side of the head core from the tape contacting surface, and a plurality of comb teeth having different depths on the tape contacting surface of the head core. A thin film magnetic film whose ends are arranged in a straight line, and the gear depth is determined by the number of missing comb teeth of the monitor pattern exposed on the polished surface during polishing of the tape contact surface. Head manufacturing method. 2. A connection pattern is formed on the substrate to be electrically connected to each comb tooth of the monitor pattern, and the gap depth is determined based on the electrical continuity state of the connection pattern. A method of manufacturing a thin film magnetic head according to claim 1.