JPS5920166B2 - thin film magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin film magnetic head, and an object of the present invention is to provide a thin film magnetic head that has high recording and reproducing efficiency and can efficiently record and reproduce data.

An example of a conventional wound type multi-channel thin film magnetic head is shown in FIG.

In this conventional example, a conductive layer 2 is formed on a ferromagnetic substrate 1 using a method such as vapor deposition, electrodeposition, or sputtering, and a photo-etching technique. Further, a magnetic layer 3 made of permalloy or the like is formed so as to partially cover the conductive layer 2 using a method such as vapor deposition, electrodeposition, or sputtering, and a photo-etching technique. FIG. 2 is a sectional view when the coil is wound twice.

FIG. 2 will be explained in the order of formation. First, a nonmagnetic conductive layer such as aluminum or copper is deposited on the ferromagnetic substrate 12 using a method such as vapor deposition, electrodeposition, or sputtering, and then a bias layer is formed using a method such as photoetching or sputter etching. A coil 13 and a signal coil 14 having a hook-shaped common electrode are formed. SiO, so as to cover both coils,
An insulating film 17 of SiO2 or the like is deposited to provide electrical insulation between the conductive ferromagnetic layer 10 of Permalloy or the like. Further, the ferromagnetic layer 10 is an insulating material layer 18 such as Si-5102.
covered and protected. On top of this is a protective substrate 20 such as glass.
is fixed with resin 19 to protect the head. In the magnetic head formed in this manner, the distance between the ferromagnetic thin film 10 and the ferromagnetic substrate 12 approaches each other at the recess 21, causing magnetic leakage, which is generated and detected by the signal coil 14. The recording and reproducing efficiency of the magnetic field is so low that it is not practical. Third
The figure is a sectional view of a magnetic head according to the present invention. First, a non-magnetic insulating material layer such as SIO, SiO2 or Al2O
3 or the like, the bank 22 is partially formed on the ferromagnetic substrate 12 by mask vapor deposition, etching, or the like. Next, a conductor layer is deposited thereon using a method such as vapor deposition or sputtering. This conductor layer is formed into the coil 13 and the coil 14 using photo-etching technology. As shown in FIG. 3, the coil 13 is formed on a part of the embankment and the substrate, and the coil 14 is formed to be located on the embankment. The parts associated with the coil 14, ie, the connection part, the coil part, and the electrodes, are formed on the same plane on the embankment 22. Embankment 22
When forming the ferromagnetic layer 10, a portion of the ferromagnetic material layer 10 is removed using a photoetching technique so that the back gap is as small as possible. When the embankment 22 is formed under the signal coil 14 in this way, the depression 21, which was a problem in the magnetic head having the structure shown in FIG. 2, is separated from the ferromagnetic substrate 1 by the embankment 22. Magnetic leakage through the recess 21 is reduced.

Now, the efficiency at low frequency of two parallel magnetic plates is η
o=Tand('λ)/(υλ), (where λ:★μ・
S-t) 1t: Magnetic path length μ: Magnetic permeability S: Magnetic film thickness
t: distance between magnetic bodies), and compare the efficiency of the heads shown in FIGS. 2 and 3. It is assumed that the width a of the coil 13 in FIG. 2 is equal to the widths d and e of the coil 13 in FIG. Considering t1 to be equal and considering that the distances between the magnetic bodies T2 and T3 are different from t1, the distances between the magnetic bodies t1 and T2 in FIG. 2 are smaller than the distance between the magnetic bodies T3 in FIG. 3, so λ in FIG. 2 becomes smaller, and the efficiency in FIG. 3 becomes better than the efficiency in FIG. 2. In the above embodiment, the coil 13 is used to flow a bias current, automatic reversal, a control signal for generating a marker indicating the content or type of a recording signal, or other control signals. You can also use

In this way, the present invention can improve the efficiency during recording and reproducing by providing a bank made of a non-magnetic insulator under the signal coil.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a main part of a conventional wound type magnetic head, FIG. 2 is a sectional view thereof, and FIG. 3 is a sectional view of a thin film magnetic head according to an embodiment of the present invention. 10...Magnetic material, 12...Ferromagnetic substrate, 13...Bias coil, 14...
...Signal coil, 17...Insulating layer, 18...
...Insulating material layer, 19...Resin, 20.
...protection board, 22...bank.

Claims (1)

[Claims] 1. A bank-like part made of a non-magnetic insulator formed on a ferromagnetic material, a conductive layer formed on the bank-like part, and a conductive layer formed at least on the conductive layer and on the ferromagnetic material. 1. A thin film magnetic head comprising: a nonmagnetic insulator layer; and a magnetic layer formed from above the nonmagnetic insulator layer to above the ferromagnetic material.