JPS6284415A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To permit easy gap depth working by embedding a low magnetic layer, nonmagnetic conductive layer and further nonmagnetic insulating layer into a recess of a nonmagnetic substrate which is preliminarily grooved and providing an upper magnetic layer in a position approximately equal to the horizontal plane of the substrate. CONSTITUTION:The hollow groove is formed to the nonmagnetic substrate 11 by a dicing machine and the non-conductive nonmagnetic film 12 is formed thereon if the nonmagnetic substrate has electrical conductivity. The lower magnetic layer 13 is then formed in the bottom of the recess. The insulating layer 15 is formed thereon by photolithography and a conductive coil 16 and insulating layer 17 are formed thereon. The insulating layer 17 is formed in the position approximately equal to the top surface of the recess. A nonmagnetic inorg. material 14 such as SiO2 or Al2O3 is further stuck thereto to obtain a gap length and the upper magnetic layer 18 is formed. A bar arrayed with 24 pieces of the thin film heads like a 3-inch bar is subjected to gap depth working at one time. The inner gap of the upper and lower magnetic poles is thereby increased and the magnetic leakage is decreased. The head efficiency is thus improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a thin film magnetic head, and more specifically, a magnetic film, a conductive film, and a nonmagnetic insulating film are formed on a substrate, and a protective film is formed on a magnetic circuit pattern. The present invention relates to a thin film magnetic head having a structure in which .

[Summary of the invention]

The present invention provides a magnetic head in which a coil made of a conductive material is sandwiched between upper and lower magnetic layers made of a soft magnetic material. The thin-film magnetic head is embedded in the concave part of the substrate and the upper magnetic layer is positioned approximately at the same position as the horizontal surface of the substrate, which facilitates gap depth processing and has the effect of minimizing variations in track width dimensions. .

[Conventional technology]

FIG. 2 shows a cross-sectional view of a conventional thin film magnetic head.

A nonmagnetic insulating layer 22 is formed on the nonmagnetic substrate 21 as required, and a lower magnetic layer 25 is provided thereon.

A nonmagnetic insulating layer 24 serving as the gap length is laminated thereon. Furthermore, a nonmagnetic insulating layer 25 is formed.

This nonmagnetic insulating layer is often made of a 71-debaked photoresist. On top of that, a coil 26t that becomes a conductor
- form and further laminate the nonmagnetic insulating layer 27. Further, an upper magnetic layer 28 is formed thereon. At that time, the upper magnetic layer is joined to the lower magnetic layer at the gap. Therefore, the height difference between the upper magnetic layer and the lower magnetic layer is about 10-odd micrometers or more even if the coil is a single layer.

Further, it is common to form a protective layer 29t of S10° or M@O@ as a protective film on the upper magnetic layer.

[Problems and Objects to be Solved by the Invention] Generally, a thin film magnetic head has a lower pole layer, an insulating layer, a coil, an upper pole layer, and a protective film layer formed on a flat surface of a nonmagnetic ferrite or ceramic substrate. That is, it has a structure in which each layer is laminated on a substrate. For this reason, the molding of each layer has a disadvantage in that steps increase toward the top, resulting in poor mask alignment accuracy.

In addition, in particular, as the level difference becomes higher, it becomes difficult to fit the track width into the track width tolerance. Nonmagnetic insulating layer 2
5 determines the position of gap depth 0, but if an organic material is used for the insulating layer, the flow of the photoresist will vary even if the heartbake conditions are strictly applied. It requires great difficulty.

There is also a method of creating a non-magnetic insulating layer using an inorganic material.
It has the drawback that it is technically difficult to planarize and planarize the difference in level, and the cost is also high.

There are also examples in which a lower magnetic layer is formed in the recessed portions, as shown in FIG. 1 of the conventional example of JP-A-58-25516.
Since these coils and the upper insulating layer are formed above the recess, it is difficult to process the gap depth to meet the dimensional tolerances, as described above.

More specifically, since the gap depth of thin-film magnetic heads is processed in large numbers at once using a bar, if the position of the gap depth 0, which is regulated by a non-magnetic insulating film, varies, the yield rate of the processing will be reduced. very low.

Therefore, the present invention solves these problems and provides a thin film magnetic head in which the track width can be easily determined and the gap depth can be easily processed.

[Means for resolving intermittent points]

The present invention provides a magnetic head in which a coil made of a conductive material is sandwiched between upper and lower poles made of a soft magnetic material, including a lower magnetic layer and a non-magnetic conductor. - Furthermore, it is a thin film magnetic head having a structure in which a nonmagnetic insulating layer is embedded in a recessed part of a nonmagnetic substrate that has been grooved in advance, and the upper magnetic layer is located at approximately the same position as the horizontal surface of the substrate.

〔Example〕

A cross-sectional view of the structure of the present invention is shown in FIG. First, a concave groove is cut into the nonmagnetic substrate II using a dicing machine. Its dimensions are determined by its relationship with the yoke length.

However, if the nonmagnetic substrate is electrically conductive, it is necessary to form the nonconductive nonmagnetic film 12. As a method, a non-conductive non-magnetic film may be formed in advance to be as thick as the depth of the recess, and then grooves may be formed using a dicing machine.

Next, a lower magnetic layer 15 is formed at the bottom of the recess using a well-known method, ori-photolithography.

Furthermore, an insulating layer 15 is formed. The inventors used photoresist. 240℃ for nohede pake conditions
*60 minutes was adopted. Next, a conductive coil 16 is formed, and an insulating layer 17f is further formed. All of the above can be formed by known methods, and all of them are embedded in the recess.

In particular, the insulating layer 17 needs to be located at approximately the same position as the upper surface of the recess. Furthermore, in order to create a gap length, S10. Alternatively, a non-magnetic inorganic substance 14 such as M, 01, etc. is attached. Next, the upper magnetic layer 18 is produced. This can also be easily produced by a well-known method. At this time, all trunk widths were within tolerance. All of the thin film magnetic heads of the present invention have a tolerance of 20±1 μm, but a conventional simple laminated thin film magnetic head has a thickness of 20±5 μm, which results in a very low yield.

Next, regarding the gear depth sword Roe, when we performed gap depth processing on a 5-inch bar with 24 thin film heads lined up at once, the gap depths were all within the tolerance of 2±1μ. In the conventional example, it was about s±4μ. This greatly deviates from the gap depth tolerance,
Approximately 60% of the products are defective.

Note that after this, in order to protect the magnetic layer etc., a protective layer 19 is formed.
It is preferable to form

In the embodiment of the present invention, the magnetic layer 1@, the insulating layer, and the coil are all formed in the recessed portion, but a portion of the coil may be formed outside the recessed portion.

〔Effect of the invention〕

The thin film magnetic head having the structure af of the present invention has the following effects.

fl+ It has a thin-film magnetic head structure that facilitates gap depth processing. (2) To determine the track width, the trunk width tolerance can be reduced because the rod is flat.

(3) By making the recess deep, the inner gap between the upper and lower magnetic poles becomes larger, magnetic leakage decreases, and head efficiency increases.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a thin film magnetic head according to the present invention. FIG. 2 is a sectional view of a conventional thin film magnetic head. tt, 2t... Non-magnetic substrate 12.22... Non-conductive non-magnetic layer 15.25... Lower magnetic layer 14.24... Gap length forming layer (non-magnetic insulating layer) +
5.17.25.27...Nonmagnetic insulating layer 16.26.
...Left coil 18.28...Top magnetic layer 19.29...Protective layer G, D...Gear tube depth or more

Claims (1)

[Claims] In a magnetic head consisting of a coil made of a conductive material sandwiched between upper and lower poles made of a soft magnetic material,
A thin-film magnetic head in which a lower magnetic layer, a non-magnetic conductor layer, and a non-magnetic insulating layer are embedded in a grooved recess of a non-magnetic substrate, and the upper magnetic layer is located at approximately the same position as the horizontal surface of the substrate.