JPH02254614A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To facilitate a patterning and to stabilize a yield by making an insulating film to cover a most upper coil among coils with plural layers into a duplex structure and executing the formation so that the size of the insulating film of the upper layer of the insulating film can be made larger than the size of the insulating film to cover a most lower layer coil and smaller than the size of the insulating film just under the most lower layer coil. CONSTITUTION:A third insulating film 9 and a fourth insulating film 10 are laminated, an upper magnetic film 11 and a protecting film 12 are successively laminated on them, and thereby, the formation is executed. The size of the fourth insulating film 10 is made smaller than the size of a first insulating film 5 and larger than the size of a second insulating film 7. Consequently, since the fourth insulating film 10 is formed on the third insulating film 9, the stage difference of the insulating films with three layers composed of the first insulating film 5, second insulating film 7 and third insulating film 9 can be solved, and a smooth surface is made. Thus, a ruggedness does not exist in the upper magnetic film 11, an electromagnetic conversion characteristic is made excellent, the patterning is made facilitated, and the yield is stabilized.

Description

[Detailed description of the invention] (Industrial application field) The present invention applies to m*11 air heads.

[Conventional technology]

As shown in FIG. 2, the conventional film magnetic head has a lower insulating WA2, an upper magnetic film 3, a gap film 4, a first insulating WA5, and a spiral-type first Coil 6, second insulating film 7, spiral type second coil 8, third insulating film 13, upper magnetic 1I21, holding I
! It is formed by sequentially stacking films 22.

[Problem to be solved by the invention]

The conventional thin film magnetic head described above has a first insulating film 5 and a second insulating film 5.
Since the structure is such that the insulating film 7 and the third insulating film 13 are sequentially laminated, a step is formed at the boundary between the respective insulating films on the sides of these three insulating films.

That is, since the upper magnetic film 11 is formed on top of these three layers of insulating films, the above-mentioned step difference is directly reflected on the upper magnetic film 11, so the upper magnetic film 11 has a highly uneven shape, which makes the 31111 magnetic head ? ! This results in a significant deterioration of magnetic a exchange characteristics.

As a means to solve this problem, for example, Japanese Patent Laid-Open No. 62-42
There is 311. However, in this example, the outermost portion of the second coil cannot be sufficiently covered with the third insulating film, and there is a risk that the upper magnetic film and the outermost portion of the second coil may be electrically short-circuited. Further, since the position of the gap depth 0, which has a significant influence on the electromagnetic conversion characteristics, is determined by the third insulating film, the patterning accuracy of the third insulating film is extremely severe and the yield is poor.

As described above, the conventional 111m magnetic head has the disadvantages of poor electromagnetic conversion characteristics, the risk of short circuit between the magnetic film and the coil, and low product yield.

[Means to solve the problem]

In the thin film magnetic head of the present invention, the insulating film covering the uppermost layer of the plurality of coils has a double structure, and the size of the upper insulating film is larger than that of the lowermost coil. The coil is formed to be larger in size than the insulating film located therein, and smaller than the insulating film immediately below the lowermost layer coil.

(Function) The insulating film covering the top layer coil has a double structure, and the size of the upper layer of the insulating film is larger than the size of the insulating film covering the bottom layer coil, and Since the size is smaller than the size of the insulating film directly under the coil, a smooth upper magnetic film is obtained without being affected by the difference in level caused by each insulating film covering the coil, and the electromagnetic conversion characteristics are not deteriorated. There is no fear of electrical short circuit with the outermost circumferential portion of the top layer coil, and since the position of the gap depth O is determined by the insulating film directly under the bottom layer coil, patterning is easy and yield does not deteriorate.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the thin film magnetic head of the present invention.

This thin film magnetic head is the third insulator of the WJWA magnetic head shown in Figure 2! 1113 instead of the third insulator l1lI9 and the fourth insulator
An insulating rI 410 is laminated, on which an upper magnetic film 11,
Tamotsu:! 11112 are sequentially laminated. The size of the fourth insulating film 10 is smaller than the size of the first insulating film 5 and larger than the size of the second insulating film 117.

In the thin film magnetic head of this embodiment, since the fourth insulating film 10 is formed on the third insulating film 11169, the first insulating film II5
．． Second insulation 117. The step difference between the three layers of the third insulating film 9 is eliminated, resulting in a smooth surface. Therefore, there is no unevenness in the upper magnetic layer 1111, and a thin PLA magnetic head with excellent electromagnetic conversion characteristics is provided. Also, the second
Since the coil 8 is covered with two layers of insulating film, that is, the third insulating film 9 and the fourth insulating film 11110, there is no possibility of an electrical short circuit between the outermost peripheral part 14 of the second coil 8 and the upper magnetic film 11. do not have. Furthermore, the size of the fourth insulator 1110 is changed to the size of the first insulator 1110.
! Since the second insulation value is smaller than 5 and larger than 7,
Since the position of the gap depth O is determined by the first insulating film 5 as in the conventional case, the yield will not be deteriorated.

(Effects of the Invention) As explained above, the present invention has a two-layer structure for the insulating film that covers the uppermost coil, and the size of the upper insulating film that covers the lowermost coil. By making the size of the insulating film larger than the size of the insulating film and smaller than the absolute RII directly under the lowest coil, the difference in level caused by each insulating film covering the coil will not affect the upper magnetic film, resulting in excellent electromagnetic conversion characteristics. and there is no risk of electrical short circuit between the upper magnetic film and the outermost periphery of the uppermost layer coil, and
Since the position of the gap depth 0 is determined by the gap B13 directly below the lowest layer coil, patterning is easy and the yield is stable.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the thin film magnetic head of the present invention.
FIG. 2 is a sectional view of a conventional example of a thin vAIt&air head. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Lower insulating film, 3... Lower magnetic film, 4... Gap film, 5... First insulating film, 6...
・First coil, 7... Second insulating film, 8... Second coil, 9... Third insulating film, 10... Fourth insulating film, 11
. . . Upper magnetic film, 12 . . . Protective film, 14 . . . Outermost peripheral portion.

Claims (1)

[Claims] 1. In a thin film magnetic head formed by sequentially laminating a lower magnetic film, a gap film, a plurality of coil layers, an insulating film, an upper magnetic film, etc. on a substrate, the uppermost layer of the coil The insulating film covering the coil has a double structure, and the size of the insulating film on the upper layer of the insulating film is larger than the size of the insulating film covering the lowest layer coil, and the insulating film directly below the lowest layer coil is A thin film magnetic head characterized by being formed smaller than the size of the film.