JPS5837833A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent the magnetic saturation and to improve the recording and reproducing characteristics, by providing plural core parts of slab magnetic material on a nonmagnetic substrate and then forming a signal conductor over these core parts to obtain a magnetic circuit. CONSTITUTION:A magnetic layer of ''Permalloy '', etc. is formed on a flat nonmagnetic substrate 11 and then etched with a prescribed track width to obtain plural slab magnetic core parts 121, 122.... The 1st insulated layer 13 (SiO2) is formed on the core parts, and a signal conductor 14 is formed over these core parts. Then a bias conductor which is common to each magnetic circuit and the 3rd insulated layer 17 are provided on the conductor 14 via the 2nd insulated layer 15. Thus a magnetic material core part 18 is obtained. A nonmagnetic protecting substrate 20 is set at the part 18 to obtain a thin film magnetic head. The thickness of a front gap 19 is set W1, and the thickness of the conductor 14 is set W2. Then W1<=W2 is satisfied to prevent the magnetic saturation and to improve the frequency reproduction characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for forming a conductor by a method such as sputtering or vapor deposition.
The present invention relates to a thin film magnetic head configured by forming a magnetic core portion and the like.

As shown in FIG. 1, this kind of thin-film magnetic head that has been proposed in the past has a magnetic substrate 1 made of a conductive Mn--Zn alloy, ferrite, etc., and has a polished surface coated with Sin, An insulating layer 2 is formed by sputtering, and a signal conductor 3 is formed on this insulating layer 2. This signal conductor 3 is made by depositing a conductive metal layer such as Cu on the entire surface of the insulating layer 2, applying a photoresist, selectively exposing it to light corresponding to a predetermined signal conductor pattern, and developing the exposed portion. After that, a remaining photoresist portion corresponding to the predetermined signal conductor pattern is formed, and the remaining portion of the photoresist is used as a mask to perform engineering. On the signal conductor 3 formed in this way,
is sputtered to form an insulating layer 4, and this insulating layer 4
A magnetic material such as permalloy or sendust, which will become the upper core portion 5, is sputtered onto the entire surface of the magnetic substrate 1 through a .

Then, selective exposure is performed to correspond to the pattern of the upper core portion 5 that determines a predetermined track width by applying photoresist, and through a step of developing the exposed portion, a remaining portion of the photoresist corresponding to the pattern portion is formed. death,
A protective substrate 6 made of a non-magnetic oxide material such as maskelite is provided on the remaining portion of the photoresist, and then the front side in sliding contact with the magnetic tape is polished to a predetermined gap depth. This conventional thin film magnetic head is formed in such a way as to form a working gap T having the following characteristics.

In the conventional thin film magnetic head formed and constructed as described above, a magnetic material is sputtered onto the nine signal conductors 3 formed on the magnetic substrate 1, and then etched to form a predetermined trunk width. Since the upper core portion 5 to be determined is formed in a manner such that the magnetic material layer forming the upper core portion 5 is applied by sputtering, the signal conductor 3
It is unavoidable that the sloped surface 3a portion becomes thinner than the other flat surface 3b portion. That is,
This is because when forming a magnetic material layer by sputtering or vapor deposition, the growth rate of the layer depends on the angle of the substrate surface with respect to the evaporation source.

(9) When patterning the magnetic material layer to form a predetermined upper core portion 5 by chemical etching, a portion on the signal conductor 3 is etched more than necessary, resulting in a constricted shape. In this way, in the conventional thin film magnetic head, the upper core portion 5 has a thinner layer or a constricted portion at the corner portion extending from the inclined surface 3a portion to the flat surface 3b portion of the signal conductor 3. , magnetic saturation occurs in the thin layer extending from the inclined surface 3a to the corner of the signal conductor 3, and even if the current supplied to the signal conductor 3 is increased, sufficient magnetic flux is not transmitted to the operating gear T side. ing.

Therefore, the present invention has been proposed with the aim of solving the above-mentioned drawbacks that the conventional ones have, and the present invention has been proposed with the aim of solving the drawbacks of the conventional ones as described above. A core part forming a magnetic circuit that is formed when a pattern is formed in a flat plate state without forming a pattern on a raised signal conductor on a flat surface, and then etched to determine the track width. It is an object of the present invention to provide a thin film magnetic head which eliminates the occurrence of thin portions of the magnetic material layer in the magnetic material layer, prevents magnetic saturation from occurring, and has good recording and reproducing characteristics.

The present invention will be described below with reference to embodiments shown in the drawings.

As shown in FIGS. 2 and 3, the thin-film magnetic head constructed according to the present invention has predetermined magnetic fields formed on one flat surface of a flat non-magnetic substrate 11 made of a non-magnetic material. A plurality of flat magnetic core portions 12t, IL'', which define a track width t, and a first magnetic material core made of 81 oz.
The plurality of flat magnetic core parts I are connected to each other through the insulating layer 13 of
L, 1'2z... A plurality of signal conductors 14 formed across each. ．． 142 . . . A bias conductor common to each magnetic circuit provided between the plurality of flat magnetic core portions i21, t2t --Φ via a second insulating layer 15 made of 5in2 or the like. 16 and
The plurality of flat magnetic core portions t2. ．． t2. The signal conductor 14. ．． 14□ . . . is surrounded by the flat magnetic core portion 12. ．． t2,...
In addition, a magnetic core portion 1B constituting a magnetic circuit is laminated.

A protective substrate 20 made of a non-magnetic oxide material such as Zn or ferrite is provided on the magnetic core portion 18 .

Note that the bias conductor 16 described above may be provided as needed, and is not necessarily required.

By the way, the thin film magnetic head according to the present invention constructed as described above is constructed through the following steps.

First, as shown in FIG. 4A, a magnetic material such as permalloy is deposited or sputtered to a thickness of 2 to 4 μm on the entire flat surface of a flat nonmagnetic substrate 11 made of a nonmagnetic material to form a magnetic material layer 112. form.

Next, as shown in FIG. 4B, the magnetic material layer 112 is coated with two layers. A plurality of flat magnetic core portions 12. are formed to define a predetermined track width t. ．． 122... is formed.

Here, the flat magnetic core portion 12. ,12. .

The etching performed to form the plurality of flat Wi magnetic material core parts 2. ．． Corresponds to i2□... Chemical etching or ion etching, etc., in which a pattern is selectively exposed to light and the exposed portion is developed to form a photoresist residue corresponding to the pattern, and this photoresist residue is used as a mask to perform etching by immersing it in an etching solution. This is done by dry etching.

Here, the flat magnetic core portion 1 that determines the track width t
21, 122... are formed by etching the entire magnetic material layer 112 formed on the flat non-magnetic substrate 11, so they can be formed with extremely high processing precision.
It is possible to define the track width t with good dimensional accuracy.

Further, this flat magnetic core portion 12. ．． t2゜Φ・・
- Since the etching for forming is performed on a flat plate, uneven reaction to the etching solution can be prevented when chemical etching is performed.

Therefore, it is possible to form the flat magnetic core portions 12+, 12t, . . . with an even and uniform thickness.

As described above, the flat magnetic core portion 12. ,12°...
After forming, a plurality of flat magnetic core portions 12. are formed on the entire surface through a first layer of 5 in.2 or the like as shown in FIG. 4C. ,12. ... Signal conductors 141, 14 . . . corresponding to the core portions 12 □ , 122 . . . ... is formed. These signal conductors 14. ．． 14. ... is formed by sputtering and etching a conductive material.

Subsequently, a second insulating layer 15 made of Sin, etc. is provided to prevent short circuits with the signal conductors 14□, 142, . . . As shown, a plurality of flat magnetic core portions 121.12□
A bias conductor 16 is provided by sputtering and etching to a thickness of about 10 to 20 μm common to each magnetic circuit over the mountain range.

Subsequently, a third insulating layer IT made of StO, etc. is provided to prevent short circuit with the bias conductor 16. In addition, at the place where this third insulating layer 1γ is provided, each of the above-mentioned core portions i2 which becomes a back gap between each of the flat magnetic core portions 12□, 122, . . . and the magnetic core portion 18, if necessary.
．． ．． The second and third insulating layers 13゜15.17 on the joints of 18 are removed by etching, and the front gap 19, which will be the working gap on the front side that makes sliding contact with the magnetic tape, is etched. The thicknesses of the first, second, and M3 insulating layers 13, 14, and 17 to be laminated are adjusted to a required gap length.

Then, as shown in FIG. 4E, a plurality of flat magnetic core portions 12°, 12. ...
・The signal conductors 14□, 142・
. . . Surrounding the above-mentioned flat magnetic core portion 12t, IL・
q! constitutes a magnetic circuit with... A magnetic core portion 18 common to the RA circuit is formed. This magnetic core part 1
8 is made of permalloy, which is a magnetic material, for example, with a thickness of 15 to 20μ.
It is formed by sputtering and etching, or by mask vapor deposition using a mask, to a thickness of . A thin film magnetic head according to the present invention is constructed by providing a protective substrate 20 on the magnetic core portion 18 as shown in FIG.

According to the present invention configured as described above, the flat magnetic core portion that determines the predetermined track width is formed by etching a magnetic material layer formed on a flat nonmagnetic substrate. Unlike conventional products, there is no unevenness in thickness.

The magnetic core portion formed on the signal conductor may be provided so as to be laminated on the signal conductor, and there is no need to perform etching to obtain a predetermined track width, so its thickness can be adjusted freely. It becomes possible to select. Therefore, it is possible to eliminate thin portions of the magnetic core layer near the slopes and corners of the signal conductor, which occur when etching is performed to define a predetermined track width as in the conventional method. A thin film magnetic head with good recording and reproducing characteristics without saturation can be constructed.

In particular, according to the present invention, since the thickness of the magnetic core portion formed on the signal conductor can be freely selected and formed, the thickness of the magnetic core portion can be reduced to the thickness Wl of the front gap 19 portion.
If the relationship between the thickness W2 on the signal conductors 14□, 1, 4□, etc. is set so that W1 ≦W, the distribution of the recording magnetic field becomes even sharper when recording short wavelength signals. Therefore, the frequency characteristics (f characteristics) can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example. FIG. 2 is an exploded perspective view showing one embodiment of the present invention, and FIG. 3 is a sectional view thereof. 4A to 4E are process diagrams for constructing a thin film magnetic head according to the present invention. 11Φ・Sachi non-magnetic substrate 12, . 12□... Φ... Flat magnetic core part 1
4□ , 142... Signal conductor 18...Magnetic core section Patent applicant Nny Co., Ltd. Agent Patent attorney - Koike Mima 1) Ei Mura - 1s Procedural amendment (voluntary) Showa January 1957, 20 accounts Commissioner of the Japan Patent Office Shima 1) Haruki Tono1, Indication of the case 1982 Patent Application No. 1355952, Name of the invention Relationship to the case Patent applicant address Kitashina 6, Tokyo Parts Co., Ltd. Chome 7-35 Name (21
8) Sony Corporation (8″) Representative Kazuo Iwama 4, Agent 〒105 Voluntary 6, “Detailed description of the invention & 0 column 7, Contents of amendment 191′・; r. - (7-1) ``Mn-Zn alloy, ferrite, etc.'' described in the specification, page 1, lines 1-6 to line 17, is referred to as ``F, -A no SL system.'' alloy, Mn-2n7 elite, etc.”. (7-2) Same book, page 2, lines 18 to 19
"Zn1 ferrite, etc." written in the second line is corrected to "Zn ferrite, etc." (7-3”) “3a” written in the 11th line of page 3 of the same book is corrected to “3b” and “3b” to “3a”. (7=4) In the same book, on page 4, line 11, "3a" is corrected to "3b" and "3b" to "3a". (7-5) "3a" written in the 4th line of page 4 of the same book is corrected to "3b". (7-6) "rzn1 ferrite" written on page 5, line 19 of the same book is corrected to "Zn ferrite."

Claims (1)

[Claims] A plurality of flat magnetic core portions formed on a non-magnetic substrate, a plurality of conductors formed across each of the plurality of flat magnetic core portions, and a plurality of conductors extending over the plurality of flat magnetic core portions. 1. A thin film magnetic head comprising a magnetic core portion which is formed to surround the conductor and constitute a magnetic circuit with the flat magnetic core portion.