JPS5931770B2 - Manufacturing method of magnetic head core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a magnetic head core with high dimensional accuracy using electroplating and etching.

FIG. 1 shows the structure of a thin film magnetic head.

In the figure, 1 is a substrate, 2 is a metallized layer as a base for plating, 3 is a lower magnetic body that is part of the core, 4 is an upper magnetic body, and 5 is a coil conductor that also serves as a head cap.
tw is the track width of a thin-film magnetic head (hereinafter simply referred to as head), and in a head with a high track density, tw is 100 mm.
μ・m or less is required. The track width is the lower magnetic body 3,
It is determined by the width of the upper magnetic body 4. For this reason, it is necessary to manufacture the lower magnetic body 3 and the upper magnetic body 4 to the designed size. Since both the lower magnetic body 3 and the upper magnetic body 4 are the core of the head, they require a thickness of 1 μm or more, and for this reason, plating with a magnetic material such as permalloy, which has a fast film growth rate, is used.

Since the method of manufacturing the lower magnetic body 3 and the upper magnetic body 4 is almost the same, the former will be described below. Conventionally, the manufacturing process for the lower magnetic body 3 has been as shown in FIGS. 2 and 3.

In the figure, 6 is a magnetic film deposited on the metallized layer 2 by plating, and 1 is an etching photoresist image for processing the magnetic film 6 into the lower magnetic body 3 by photoetching.

8 in FIG. 3 is a plating photoresist image for forming the lower magnetic body 3 on the metallized layer 2. In FIG. Next, each manufacturing process will be explained.

In FIG. 2, a metallized layer 2 is formed on the substrate 1 as a base for plating by vapor deposition or the like (FIG. 2). Next, a magnetic film 6 such as permalloy is plated on the entire surface of the metallized layer 2 (Fig. 1), a photoresist image 1 for etching is formed on the magnetic film 6 (Fig. The magnetic body 3 is formed (Figure 2), and finally the photoresist image □ for etching is removed to form the lower magnetic body 3 (Figure E), but the track of the lower magnetic body 3 (Figure 2 D) is The width is narrower than the width of the etching resist image 1 due to an undercut phenomenon in photoetching. In the manufacturing process shown in FIG. 3, a metallized layer 2 is formed (Fig. A), a photoresist image 8 for plating is formed on this metallized layer 2 (Fig. Patch the chisel (Figure C),
Finally, the plating photoresist image 8 is removed to form the lower magnetic body 3.

However, in this manufacturing process, if the total area of the lower magnetic material 3 on the metallized layer 2 is small, it is difficult to control the plating current, and in addition, if the plating metal is an alloy, it is extremely difficult to control the alloy composition, and it is difficult to control the plating current. Alloys are difficult to obtain. As described above, in the conventional manufacturing process of the lower magnetic body 3, the track width Tw. (Fig. 2), even if the track width Tw can be controlled, it is difficult to control the plating current, and in addition, if the plating metal is an alloy, the composition of the alloy cannot be controlled ( (Fig. 3), it was not easy to manufacture the lower magnetic body 3 suitable for the head core.

This problem becomes more severe when the track width Tw is less than 100 .mu.m, and is a major obstacle to increasing the track density of the head. This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by improving the plating method and etching method of the magnetic film forming the core,
Track width Tw. This makes it possible to easily manufacture a magnetic material suitable for the head core even when the head core is narrow, and enables high track density.

An embodiment of the method for manufacturing the core of a magnetic head according to the present invention will be described below with reference to the sectional view of FIG. 4 showing the manufacturing process. A metallized layer 2 is formed on the substrate 1 by vapor deposition or the like as a base for electroplating (FIG. 1). Note that if the substrate 1 itself is made of a material that can be plated, the metallized layer 2 is not necessary. Furthermore, the substrate 1 or the metallized layer 2 is collectively referred to as a base material. Next, partitions 9 are formed on the metallized layer 2 using a photoresist image for plating. (mouth view). The interval between the partitions 9, that is, the inner dimension 1, is made equal to the core width, that is, the track width Tw of the lower magnetic body 3. The shape of the periphery of the lower magnetic body 3 is determined by the partition 9 . Next, photoresist coating plating is performed to coat the magnetic film 6 such as permalloy on the metallized layer 2.
Attach it to the top (Figure C). At this time, the plating film does not adhere to the photoresist image, that is, the partition 9 portion. The core plating portion between the partitions 9 will be referred to as the first core metal film 3, and the other plating portions will be referred to as the second metal film 10.

Furthermore, since the area occupied by the photoresist image 9 is extremely small compared to the plating area, it has almost no effect on the alloy composition forming the magnetic film 6. Next, using a mask alignment device or the like, the first metal film 3 for the core that is left without being etched is covered, including the sides, with a photoresist image 11 for etching having a width slightly wider than the first metal film 3 for the core (Figure 2), and metallized. Etching is performed using an appropriate etching solution that does not dissolve the layer 2, and the second metal film 10 is removed (FIG. 5). At this time, since the top and side surfaces of the first metal film 3 are covered with the photoresist images 9 and 11, the first metal film 3 is not etched and there is no undercut phenomenon. After that, all the photoresist images 9 and 11 are removed to expose the desired first metal film 3 for the core, that is, the lower magnetic body 3 (see Fig. 3).
The width of the lower magnetic body 3 thus obtained matches the inner dimension of the photoresist image 9 for plating with high accuracy.

Therefore, it is possible to easily and accurately form the core of the head with a narrow track having a track width of 100 .mu.m or less. In the embodiment shown in FIG. 4, the top and side surfaces of the first metal film 3 are covered with photoresist images 9 and 11.
If the photoresist image 9 is removed after plating the metal film in FIG.

Further, if there is no need to remove the photoresist image after etching in FIG. 4E, the step of removing the photoresist image 7 in FIG. 4 is unnecessary. As described above, according to the present invention, it is possible to avoid the undercut phenomenon during photoetching, so that the plating area can be increased by plating parts other than the first metal film for the core that has good dimensional accuracy and is required. Therefore, the plating current can be easily controlled and a homogeneous first metal film for the core can be formed even in the case of an alloy.

Therefore, even when the track width of the head core is narrow, an appropriate first metal film for the core can be easily manufactured and a high track density can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a thin-film magnetic head, in which A is a plan view, C is a sectional view taken along the I-10 line of the cap, and C is a sectional view taken along the I-H-I C line of A.

Claims (1)

[Claims] 1. A first step of forming partitions with a photoresist image on the base material whose intervals are regulated to the core width, electroplating metal while leaving the photoresist image on the base material that has been subjected to the first step, and a second step of forming a first metal film for the core between the partitions and a second metal film other than the first metal film for the core; a third step of covering the side and top surfaces of the first metal film for the core with a photoresist image; A method of manufacturing a core of a magnetic head, wherein a fourth step of removing the second metal film by etching is performed after the second metal film is formed.