JPH04351707A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To decrease the deformation of coil layers and to prevent the wire fining of coils and the shorting between coil layers even if the coil patterns of the thin-film magnetic head are made into a multilayered structure. CONSTITUTION:The thin-film magnetic head constituted by forming a lower magnetic core 2 on a substrate 1, forming a magnetic gap layer 8 and the multilayered coil patterns in which the respective coil layers 41, 42, 43, 44 are insulated and separated by insulating layers 51, 52, 53, 54 on this lower magnetic core 2 and further, forming an upper magnetic core 9 thereon is provided. First and second dummy patterns 111, 112, 113, 114, 121, 122, 123, 124 which are respectively electrically separated from the coil patterns are formed on the outer periphery and inner periphery of the coil patterns.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to magnetic disk devices, VT
The present invention relates to a thin film magnetic head used in magnetic recording devices such as R.

0002

[Prior Art] Conventionally, as a method for forming two or more conductor coil layers in a thin-film magnetic head, a method has been used in which the insulating layer between the coil layers is flattened by an etch-back method to prevent wire thinning and breakage of the coil. It has been adopted.

A conventional method for manufacturing a thin film magnetic head will be described below.

First, as shown in FIG. 3, a metal magnetic thin film made of sendust, an amorphous magnetic material, etc. is coated on the upper surface of a substrate 1 made of a non-magnetic material such as crystallized glass or a magnetic material such as ferrite by sputtering, vapor deposition, etc. After forming the lower magnetic core 2 by patterning it by ion milling or the like using a resist mask, an insulating layer 3 made of SiO2, Al2O3, etc. is deposited on the lower magnetic core 2 by sputtering or the like. do.

Next, as shown in FIG. 4, a conductive layer of Cu, Al, etc. is formed on the insulating layer 3 by sputtering, vapor deposition, etc., and patterned by ion milling, etc.
A second coil layer 41 is formed.

Next, as shown in FIG. 5, the coil layer 41
An insulating layer 51 made of SiO2, Al2O3, etc. is deposited thereon by sputtering or the like to a thickness greater than that of the coil layer 41. Incidentally, irregularities are formed on the upper surface of the insulating layer 51 depending on the presence or absence of the coil layer 41.

Next, as shown in FIG. 6, a resist 6 is coated on the upper surface of the insulating layer 51 by a method such as overcoating. At this time, the upper surface of the resist 6 is substantially flat.

Next, as shown in FIG. 7, the resist 6 is etched away by ion milling or the like until the insulating layer 51 is exposed. By this etch-back process, the upper surface of the insulating layer 51 becomes substantially flat along the shape of the upper surface of the resist 6.

Through the steps shown in FIGS. 3 to 7, the first layer coil pattern is completed.

Next, as shown in FIGS. 8 to 10, a second layer coil pattern is formed in the same manner as the above-described process. 8 shows a state in which an insulating layer 52 is formed on the second coil layer 42, FIG. 9 shows a state in which a resist 6 is formed on the insulating layer 52,
FIG. 10 is a diagram showing a state in which the upper surface of the insulating layer 52 is planarized by an etch-back method.

Next, as shown in FIGS. 11 and 12, 3
A layered coil pattern is formed. FIG. 11 shows a state in which the third coil layer 43, insulating layer 53, and resist 6 are formed.
FIG. 12 is a diagram showing a state in which the upper surface of the insulating layer 53 is planarized by an etch-back method.

Next, a fourth layer coil pattern is formed as shown in FIG. 13 in the same manner as described above. 44 is a fourth coil layer, and 54 is an insulating layer whose upper surface is flattened.

Next, as shown in FIG.
, 52, 53, and 54, a portion that will become a front gap and a portion that will become a back gap are etched away by ion milling or the like until the lower magnetic core 2 is exposed, thereby forming through holes 7a and 7b.

Finally, a magnetic gap layer 8 made of SiO2 or the like, an upper magnetic core 9 made of a metal magnetic material such as sendust or an amorphous magnetic material, and a protective insulating layer 10 made of SiO2, Al2O3, etc. are formed by sputtering, ion milling, etc. The thin film magnetic head shown in FIG. 15 is completed by depositing it into a predetermined shape. In FIG. 15, 5 is an insulating layer composed of the insulating layers 3, 51, 52, 53, and 54.

[0015] In the method of planarizing the insulating layer between the coil layers using the etch-back method as described above, the accuracy of applying the resist used for planarization is a problem. That is, in the portion where the coil layers 41 are densely packed in FIG. 6, the upper surface of the resist 6 is well flattened because the spacing between the coil layers is narrow, but at the outer and inner edges of the coil pattern, the resist 6 is flattened. The upper surface is not sufficiently flattened, and steps A and B occur. In the areas where these steps A and B occur, the thickness of the resist 6 is thinner than in other areas, so in the etch-back method, which performs etching under conditions where the etching rate of the insulating layer and the resist are equal, only a predetermined amount of insulation is required. When the layer is etched, as shown in FIG. 7, a portion A1 on the outer edge of the coil pattern and a portion B1 on the inner edge of the coil pattern become thinner than other portions of the insulating layer 51. , deformation occurs due to the step. As can be seen from the figure, such deformation and thinning of the insulating layer become more noticeable as the layers go higher.

Furthermore, as shown in FIG. 13, in the second and subsequent layers of coils formed on the insulating layer 51 that is insufficiently planarized,
When the coil layers at both ends are deformed and multilayering progresses, thinning C of the coil due to over-etching and coil short-circuiting D between adjacent coil layers occur.

[0017]

[Problems to be Solved by the Invention] The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and it is an object of the present invention to provide a thin film magnetic material that prevents wire thinning and short-circuiting of the coil even when the coil pattern is multilayered. The purpose is to provide a head.

[0018]

[Means for Solving the Problems] The thin film magnetic head of the present invention is characterized in that dummy patterns are formed on the outer and inner peripheries of a coil pattern, respectively, and are electrically separated from the coil pattern.

[0019]

According to the above structure, deformation of the shape of the coil layer occurs in the dummy patterns located on the outer and inner peripheries of the coil pattern, and no thinning of the coil or short circuit between the coil layers occurs in the coil pattern.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a cross-sectional view of the thin film magnetic head of this embodiment, and FIG. 2 is a plan view showing the coil pattern of the first layer of this thin film magnetic head. However, I will omit that explanation.

In the thin film magnetic head of this embodiment, first and second dummy patterns 111 and 121 are formed on the outer and inner peripheries of the first layer coil pattern, respectively. The first and second dummy patterns 111 and 121 are both made of the same conductive material as the coil layer 41, and are deposited at the same time as the coil layer 41 is formed. Further, both the first and second coil patterns 111 and 121 are separated from the coil layer 41, and the thickness thereof is equal to the thickness of the coil layer 41. In addition, in the thin film magnetic head of this embodiment, the second layer, the third layer, and the fourth layer
In the coil pattern of the second layer, first and second dummy patterns 112, 122, 1 are provided on the outer periphery and inner periphery of the coil layers 42, 43, 44, respectively, similar to the coil pattern of the first layer.
13, 123, 114, and 124 are formed by adhesion. The coil layers 41, 42, 43, and 44 have a line width l1 of 4 μm at the narrowest portion located between the front gap portion F and the back gap portion B, and a line width l1 at the widest portion located behind the back gap portion B. The line width l2 of the portion is 10 μm. In addition, the first and second dummy patterns 111 and 12
1, 112, 122, 113, 123, 114, 124
The line width m1 of the narrowest part located between the front gap part F and the back gap part B is 5 to 6 μm, and the line width m1 of the widest part located behind the back gap part B
2 is 12 to 14 μm.

The magnetic head of the above embodiment has first and second dummy patterns 111, 121, 112, 122, 1
Except for the formation of 13, 123, 114, and 124, they are formed in the same manner as the manufacturing method described in the conventional example described above.

In the thin film magnetic head of this embodiment as described above, dummy patterns are formed on the outer and inner peripheries of the coil pattern, so line thinning and short circuits that are likely to occur at the outer and inner periphery edges of the patterns can be avoided. , which occurs in the first and second dummy patterns that are completely unrelated to the operation of the magnetic head, does not deform the coil layer, prevents thinning of the coil and short circuit between the coil layers, and improves reliability. Also, dummy pattern
Since the area of the upper surface of the insulating layers 51, 52, 53, and 54 formed on each coil pattern becomes larger by the amount that the coil pattern is formed, the planarization of the insulating layers 51, 52, 53, and 54 is improved.

In the above embodiment, the dummy pattern has a structure in which it goes around the outer and inner peripheries of the coil pattern.
The dummy pattern may have a structure in which it makes two or three turns around the outer and inner peripheries of the coil pattern.

[0026]

According to the present invention, thinning of the coil and short circuit between coil layers can be prevented, and a highly reliable thin film magnetic head can be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a thin film magnetic head of the present invention.

FIG. 2 is a plan view showing a first layer coil pattern of the thin film magnetic head of the present invention.

FIG. 3 is a cross-sectional view showing a conventional method for manufacturing a thin film magnetic head.

FIG. 4 is a cross-sectional view showing a conventional method for manufacturing a thin film magnetic head.

FIG. 5 is a cross-sectional view showing a conventional method of manufacturing a thin film magnetic head.

FIG. 6 is a cross-sectional view showing a conventional method of manufacturing a thin film magnetic head.

FIG. 7 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

FIG. 8 is a cross-sectional view showing a conventional method of manufacturing a thin film magnetic head.

FIG. 9 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

FIG. 10 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

FIG. 11 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

FIG. 12 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

FIG. 13 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

FIG. 14 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

FIG. 15 is a cross-sectional view showing a method of manufacturing a conventional thin-film magnetic head.

[Explanation of symbols]

1 Substrate 2 Lower magnetic core 3, 5, 51, 52, 53, 54 Insulating layer 41, 42
, 43, 44 Coil layer 8 Magnetic gap layer 9 Upper magnetic core

Claims (1)

[Claims] 1. A lower magnetic core is formed on a substrate, a multilayer coil pattern in which each layer is insulated and separated by a magnetic gap layer and an insulating layer is formed on the lower magnetic core, and an upper magnetic core is further formed on the lower magnetic core. 1. A thin film magnetic head comprising: a dummy pattern electrically separated from the coil pattern formed on an outer periphery and an inner periphery of the coil pattern.