JPS6387608A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To eliminate an abuse due to step coverage degradation of an insulating layer formed on a coil upper layer and an abuse due to cavities of the insulating layer by forming a coil so that both angular shoulder parts of its section are cut away and increasing the coil resistance. CONSTITUTION:A lower core 2, an inter-layer insulating layer 3, a conductor coil 4, and an upper core 5 are formed on a substrate 1, and the upper core 5 and the lower core 2 are connected in a core connection part 7, and a gap 8 is provided to form a magnetic circuit. Since both angular shoulder of the section of the conductor coil 4 are cut away, the problem of the layer material and peeling of the insulating layer in both coil shoulder parts are prevented. Thus, short-circuit between the upper layer coil 4b and the upper core 5 or the like is eliminated, and a head is obtained with a good yield.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thin film magnetic head for magnetic recording or reproduction, and more particularly to a thin film magnetic head having a multi-turn coil structure.

[Conventional technology]

Conventional thin-film heads are described in IBM Disk Storage Technology (1980), pages 6 to 9 (I
BM Disk Storage Tachrolol
y, Fsb, (1980), pp6-9) and JP-A No. 57-66522, the coil shapes are a Toriya cross section and a trapezoidal cross section.

Two types of surfaces have been proposed, and the coil insulating material is photoresist and polyimide, which can easily flatten the concave and convex surfaces.

Products using organic materials such as resins have come into practical use.

There is. Figure 7 shows an example of a conventional square coil head.

The two types of coils shown are rectangular in terms of cross-sectional area.

(Mouth type) coil is better than base plate (Q type) coil.

The allowable current per turn is large, and the recording ability is high.

increasing power. Also, from the point of view of coil resistance.

A square coil can have a smaller resistance value, reduce impedance noise, and improve S/N.

However, F g −Aj −S requires high temperature to form.
When a high Bs, highly abrasive magnetic thin film such as i or Co-Nh-Zr is used as the core material, an inorganic material such as f3i0x with high heat resistance is required as the insulating material for the coil instead of an organic material. In the case of a square coil, the following 6
This causes problems such as:

FIG. 8 (As shown in (Z), inorganic insulation formed on the upper layer.

Layer 3 had defective step coverage 10 and was removed.

Cracks and peeling occur due to thermal history during the process. Same again.

As shown in Figure (b), increase in the number of coil turns or magnetic path;
Coil designed to improve head efficiency by shortening the length.

If the spacing is made narrower, cavities 11 will be created in the insulating layer, and problems similar to those shown in FIG.

could not be provided.

[Problems to be solved by the invention] 1. .

In the above conventional technology, an insulating layer is formed on the coil.

No consideration was given to the quality of the film, and there was a problem of peeling of the sheet between the coils and the insulating film.

The purpose of the present invention is to provide a step bag of an inorganic insulating layer formed on the upper layer of the coil without increasing the resistance value of the coil, and to provide a head that eliminates the adverse effects caused by deterioration of the coil and the disadvantages caused by cavities in the insulating layer, and improves the yield. It's about doing.

[Means for solving problems]

The above object is achieved by making the cross-sectional shape of the coil such that both shoulders of the upper part of the coil are lowered within a range that does not affect the coil resistance.

[Effect]

By optimizing the mask material conditions for coil buttering, etc., the cross-sectional shape of the coil after ion etching is made into a shape with the upper shoulders of the rectangular coil being lowered. This allows the insulation layer to be formed as an upper layer.

Step coverage deteriorates and prevents cavity formation.

This eliminates the disadvantages caused by these and enables heads to be provided with a high yield.

〔Example〕

Below is a drawing of the thin film magnetic head of the present invention.

This will be explained in detail with reference to.

FIG. 1 shows a thin film magnetic spatula that is an embodiment of the present invention.

Figure 2 is a cross-sectional view taken along line A-A' in Figure 1.
-Figure 3 (α) C Enlarged view of the conventional head cross section (Figure 7), (
6).

2 is an enlarged view of the head cross section (FIG. 2) of the present invention.

However, the tassel, protective film, and protective plate are omitted.

The thin film magnetic head 6 includes a lower core 2 on a substrate 1.

Shaped from the glabellar insulating layer 3, the conductor coil 4, and the upper core 5. , has been completed. Upper core 5 and lower core 2 are core connection/connection part 7
are connected with a gap 8 to form a magnetic circuit. The upper and lower cores are made of a high permeability/magnetic material, such as a Co-Nh-Zr amorphous material, the glabella insulating layer is made of 8iCh, the gap is made of Cr, and the conductor coil is made of Ctb.

The conductor coil 4 is shown in FIGS. 2 and 3 (as shown at 41).

It has a square cross-sectional shape with both shoulders down (0 type).

This may cause problems with the quality of the insulating layer on both shoulders of the coil.

Upper layer coil 1. .

4ξ There is no short circuit with the upper core 5, and the yield is 1.

It is possible to provide a better head.

In addition, by adopting the ■-shaped coil structure of the present invention.

As a result, the magnetic properties near the coil ends of the upper core deteriorate.

It is also effective in preventing this, and has the advantage of improving the recording and reproducing efficiency of the head. The reason is explained below.

In manufacturing a thin film head, it is necessary to form an insulating layer with flattened irregularities of the coil by some method after forming the coil to prevent deterioration of magnetic properties due to the irregularities. The etch-back method is the best planarization method.

4. Often used. In this case, it is difficult to determine the end point of etching, and the process often ends with a slight difference in level (insufficient or insufficient etching). FIG. 3 shows the difference between the conventional coil structure (α) and the coil structure of the present invention. That is, in both figures, the magnetic properties of the upper core near the end of the coil indicated by symbol X deteriorate in the conventional structure, whereas according to the present invention,
Since this part has a gentle slope and slope, no deterioration of magnetic properties occurs. More.

From the above, according to the present invention, there is an insulating layer forming step.

In this regard, the process margin can be significantly improved.

However, the effect of improving head yield is that of dogs. .

Next, make the coil into a square cross-section with both shoulders down.

The first method of patterning is to etch the conductor film 4', which has a film thickness a and ma, as shown in FIG. 4 (1).

The film thickness of the mask material is determined from the etching speed of the surface material 9.

Determine. For example, if the conductor film is Cw s μm, a.

The on-etching conditions were Iarc: 1.6 A,
Vacc: 700 V*.

When the beam incidence angle is 0°, photoresist (my.

Croposit) film thickness of 1.8 μm is appropriate. In the figure, two people etched the conductor film by ion etching. In general, the etching speed of the shoulder part A is faster than other parts, so after etching is completed, the result will be as shown in Figure 3), and after the resist is removed, an O-shaped coil as shown in Figure 4) will be obtained. be able to.

As shown in Fig. 5 (1), the second method of patterning is to apply a resist film thick enough to leave resist on the coil end portion B at the end of etching the conductor film. The conductor film 4 is etched. When the etching of the conductor film is completed, the cyst 12 is returned by 1° as shown in FIG. 2). Due to the flattening effect of the resist.

The film thickness d on the coil is thin, and the film thickness between the coils e.

becomes thicker. For example, Il [6 μm, 1 interval 4 μm, step 3
In the case of μm, d is 0.8 μm and g is 6.5 μm. film.

The resist 12 is applied under the conditions of ζ5 so that the thickness e becomes thicker than the film thickness C on the end of the coil. Ion etching.

As a result, both shoulders C at the end of the coil are etched.

Etch until. , (Figure 3)) Remove the resist.

Then, a type 0 coil as shown in the same figure can be obtained.

can. According to this method, the condition range of the resist film thickness for coil patterning becomes wider by %2°.7. compared to the first method.

FIG. 6 shows a second embodiment of the invention. - As shown in FIG. 6 (1), a second metal layer 13 is formed on the conductor film 4' by vapor deposition, sputtering, etc. - If possible, it is globally desirable to form it in the same chamber as the conductor film. The second metal layer is selected to have a slower etching rate than the conductor film 4'. .

For example, when the conductive film is made of Ctb, At, etc., Cr, Ti, NiCr, etc. may be used as the second metal layer.

Further, when the conductor film is Cμ, for example, approximately Cr500X is required as a bonding layer on the upper and lower layers of the conductor film.

Therefore, by increasing the thickness of the upper bonding layer, the

Similar effects can be obtained without the added process. 15 According to this method, it is possible to reduce the thickness of the resist film in the coil patterning, thereby improving chisel turning accuracy and reducing over-edge.

Changes in the coil shape due to chipping are small and the processing margin is large. 2°, 8
.

[Effects of the Invention] As described above, according to the present invention, by forming the coil with a rectangular cross-sectional shape with both shoulders lowered, it is possible to form the coil in the upper layer without increasing the coil resistance. Yield is improved because the negative effects caused by poor step coverage of the insulating layer and the negative effects caused by cavities in the five insulating layers are eliminated.

Well head can be provided.

[Brief explanation of the drawing]

FIG. 1 shows a thin film magnetic head according to an embodiment of the present invention. FIG. 2 is a plan view of FIG. 1, and FIG. Figure (α) is an enlarged cross-sectional view of the conventional head (Figure 7), Figure 3 is an enlarged cross-sectional view of the head cross-section of the present invention (Figure 2), and Figure 4 is a process diagram showing the coil patterning method. ,. Fig. 5 is an engineering drawing showing another coil patterning method, Fig. 6 is a cross-sectional diagram showing a second embodiment of the present invention, and Fig. 7 is a cross-sectional view of a conventional thin-film magnetic head. The 8° figure is a cross-sectional view of the insulating layer formed on the square coil. 1... Substrate, 2... Lower core, 6... Insulating layer,
4a, 48...conductor coil, 4'...conductor film,
5... Upper core, 61. . Thin film magnetic head, 7... Core connection portion, 8... Gap, 9... Photo resist, 9'... Photo resist after post baking, 10... Step coverage, 11... cavity·. 12... Photoresist, 13... Second metal layer.・Go to 4・′

Claims (1)

[Claims] 1. In a thin film magnetic head formed by laminating a lower core, a single-layer or multiple-layer conductor coil, an insulating layer for insulating between the conductor coils and the upper and lower cores, and an upper core in this order. . A thin film magnetic head, wherein the conductor coil has a rectangular cross-sectional shape with both upper shoulders down. 2. A thin film magnetic head characterized in that a second metal layer is provided on the upper layer of the conductor coil having a cross-sectional shape with both upper ends of the rectangular shape as described in item 1 cut.