JPS61202316A - Thin film magnetic head for buried servo system - Google Patents

Abstract

PURPOSE:To reduce the thermal off-track and to increase the S/N by satisfying P<ls<=2P where the track width of a servo transducer and the track pitch of a data track are set at ls and P respectively. CONSTITUTION:For instance, a transducer 24 using a magneto-resistance effect element 29 is produced by the vapor deposition and etching processes. The track width ls is set double as much as the pitch P of a data track in order to improve the S/N of a servo signal as well as the resistance to the defect of a medium. The level of the servo signal is increased by a degree equal to the increase of the width ls compared with the itch P as long as P<ls<=2P is satisfied. This improves the S/N as well as the resistance to the medium defects.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thin film magnetic head used in magnetic disk devices, floppy disk devices, and the like.

(Prior art and its problems) Conventionally, the mainstream magnetic disk device t#'i servo surface servo method has been used, but in this servo surface servo method, the servo disk and the data disk are placed on separate disk plates. Because of this, there was a risk of errors in positioning accuracy due to differences in ambient temperature. In particular, this servo surface servo method has drawbacks such as the relative positioning error of the magnetic head increases as track density increases, making it difficult to increase track density and thus making it difficult to achieve high recording density. Ta.

Recently, various data surface servo methods have been studied in order to improve head positioning accuracy, and the data surface servo methods in particular include the sector servo method that uses part of the data surface, the method that uses the data information itself, and the magnetic double layer disk. using the lower magnetic film as a servo information medium,
A method using this information (period servo method) is being considered.

The sector servo method described above is a method in which one truck is divided into sectors and servo information is inserted partially, but it has the drawback that it is not possible to perform truck, ri, or servo operations except for the part where servo information is input. Ta. Therefore, positioning accuracy is insufficient at high track densities. Furthermore, the servo method that uses data information itself as servo information has the disadvantage that a fluctuation in the output envelope of data information causes a positioning error because the data information itself is used.

Furthermore, in the servo system that uses two layers of magnetic films, the upper layer is used for data information and the lower layer is used for servo information. Data and servo information are detected simultaneously by one data head and used separately. Therefore, the positioning error is small. However, in the servo system using this magnetic double layer medium, when data information and servo information are simultaneously detected by one data head, separation of data information and servo information during reproduction is easily performed by a filter. During recording, a filter and bias circuit are required in the recording circuit to detect the servo information, resulting in a fairly complex circuit configuration, which not only degrades the servo information but also increases the cost of the circuit system. are doing. To solve this problem, we developed thin film magnetism for the peridot servo system.

A data transducer is placed on one of the two rails of the same slider, and a servo transducer is placed on the other rail. There are ways to prevent deterioration.

In such a periodic servo system, a two-frequency method has been proposed in which the servo pattern of the lower servo layer is divided into odd-numbered, ri, and even-numbered servo patterns. However, in this two-frequency method, since it is not possible to make the track width and width of the servo head wider than track width and width, the amplitude S of the servo signal is equal to V2 of the signal of the first servo track in the on-track state. This had the disadvantage that the recorded recording also deteriorated.

(Object of the Invention) An object of the present invention is to improve the above-mentioned problems and to provide a thin-film magnetic head for a carried servo system, which has a very small thermal off-track and a large one made by Katuru.

(Structure of the Invention) The thin film magnetic head for the carried servo system of the present invention includes a non-magnetic substrate forming a slider, a servo transducer for reproducing servo signals on the non-magnetic substrate, and a data transducer for recording and reproducing data signals. In a thin film magnetic head for a carried servo system having a structure in which transducers are laminated with an insulating layer interposed therebetween, the servo transducer's tiger,
width l.

is P<l8 for Datatora, Rinotora, Kubi, and ChiP.
The configuration is characterized in that ≦2P.

(Detailed explanation of the structure) As a method to solve the conventional drawbacks, a patent application filed in 1983 has already been proposed.
39642, three frequencies f,1, f,1
f, the servo transducer tiger.

A perido servo method has been proposed in which the width of the ring is twice that of the ring width of the ring, and the ring width is increased when the ring density is high.

In the above-mentioned Japanese Patent Application No. 59-139642, a data transducer is arranged on one of two rails of the same slider and a servo transducer is arranged on the other rail as a thin-film magnetic head for a carried servo system. A proposal has been made to create a thin-film magnetic system for the driven servo system, which separates the servo transducer and makes the width of the servo transducer twice that of the data. However, in that case, the conventional slider material is alumina titanium carbide (abbreviated as AiTiC), and the magnetic disk substrate is an aluminum alloy, so if you want to increase the positioning accuracy of the magnetic head, Difference in thermal expansion of this material (thermal expansion coefficient of slider material (A1TiC!) 7.8 x 1 o
-'/'C, aluminum alloy (Al: 94%, Cu: 0.1%, 8 i:
0.4%, Fe: 0.4%, Mn: 0.1-0
．． 3%, Mg: 3.8-4.8%, 0r (0.5%) thermal expansion coefficient 23.2 x 10-'/'C) causes thermal off-trace, resulting in high magnetic head positioning accuracy. It had the drawback of not being able to achieve this goal. The present invention has a configuration to eliminate the above-mentioned drawbacks. The non-magnetic substrate for the slider used in the present invention has insulating properties and has a polished surface (for example, AA!TieSSiO on top of Az
The data transducer is made of crystalline MiFe, sendust or amorphous 0oZrs, 0oTas, 0oHf, '
Magnetic poles and coils made of soft magnetic films such as CoZrNb alloy (O
The servo transducer is made of crystalline N i Fe % Sendust. and amorphous CoZr
, 0oTas 0oHfqOoZrNb alloy or other soft magnetic film, coil (C7u, etc.) and insulating layer (resist, AJ,
O,) is an inductive search element or FiN
A magnetoresistive element such as iFes NiCo is used, and the protective layer is A60. Subaru or silicone films such as Si or Si are used. The above-mentioned material is produced using a manufacturing method such as sputtering method, plating method, spin cord, ion milling, etc., and then cutting, processing, and
After polishing and assembly, a thin film head for the peridot servo system is made.

EMBODIMENT OF THE INVENTION Hereinafter, an example of a thin film magnetic head for a carried servo system according to the present invention and a method for manufacturing the same will be explained by way of an example.

(Embodiment 1) FIG. 1(a) shows a view of the thin-film magnetic head for the carried servo system of this embodiment as seen from the flying surface, and FIG. 1(b) shows the cross-sectional structure of the magnetic transducer portion.

On a non-magnetic substrate 7 (a ceramic substrate (AAiTiO substrate) coated with an Altos sputtered film and polished), a first magnetic pole 8 constituting the servo transducer 4 is coated with an ONice alloy film (film thickness 2 μm). ).

The first magnetic pole 8 is formed by the ion milling method and ion milling method.
A first insulating layer 10 is placed on top of AA'! o, Suba, Rime (
A servo fill 11 is formed on the first insulating layer by a plating method (Cu metal), and a second insulating layer 17 is formed on the servo fill 11 with a film thickness of 1 μm) and a resist. is formed by resist spin code, exposure, development and baking, and a second magnetic pole 9 (N
An AItos film with a thickness of 10 μm is formed as a third insulating layer 12 on the second magnetic pole 9 by a sputtering method, and then a A third magnetic pole 13 which is the lower magnetic pole of the data transducer 5 is formed on the third insulating layer 12 with a thickness of 2 μm.
A fourth insulating layer 1 is formed on the third magnetic pole 13 by forming a NiFe alloy film of m in thickness by a sputtering method and an ion milling method.
A data coil 16 is formed on the third insulating layer by a plating method (Cu plating). A 5th insulator 1 & NI 18 is formed on the coil 16 by resist spin code, exposure and development, and baking, and a NiFe alloy film, which is the upper magnetic pole of the data transducer 5, is formed on the fifth insulator M1g. A fourth magnetic pole 14 with a thickness of 2 μm was formed by sputtering and ion milling, and an A603 protective film with a thickness of 20 μm was formed on the fourth magnetic pole by sputtering. The wafer thus produced was processed, polished, and assembled to produce a thin film magnetic head for a carried servo system. However, the width of the servo transducer is 1. The track pitch P was set to be twice (7g=2XP) as that of the Kedatatra.

Instead of the inductive thin film head as the transducer 4, a transducer 24 using a magnetoresistive element 29 is formed by vapor deposition, processing, and etching methods, and its track width is 1. , was set to be twice that of the data track's Track Bi and ChiP. No magnetic shield was formed on both sides of this magnetoresistive element 29, and a diagonally parallel conductor (Au) for barber pole biasing was formed on one side.

(Effects of the Invention) Both of the 2m thin film magnetic heads for the carried servo system having the above configuration have thermal off-tracks that disappear because the data transducer and servo transducer have a two-stage structure. By making the track width of the transducer twice the track pitch, the servo signal quality is improved, and as an additional effect,
It is also extremely resistant to media defects.

Note that the servo transducer, which is a feature of the present invention, is not limited to the above-mentioned embodiments. If p<zs≦2P for the track pitch P of the data,
1. The servo signal becomes larger by the amount that is larger than P, and S
4 is clearly improved and more robust against media defects. Furthermore, the present invention can be applied even when the positions of the servo transducer and the data transducer are exchanged, and it goes without saying that it can also be applied to a magnetic head for a 70-tube disk device.

[Brief explanation of the drawing]

1(a), (b) and FIG. 2(a), (b) t1 Diagrams showing embodiments of the present invention. 1 is a slider, 2 is a first rail, 3Fi second rail, 4Fi servo transducer, 5 is a data transducer, 6 is a protective film, 7 is a non-magnetic substrate, 8as
1O1Eik, 9 is the second magnetic pole, 10 is the first insulating layer,
11 is a two-bore coil, 12 is a third insulating layer, 13 is a third magnetic pole, 14 is a fourth magnetic pole, 15 is a fourth insulating layer, 1
6 is a data fill, 17 is a second insulating layer, 21 is a first
20 is a slider, 22 is a second rail, 2
4Fi servo transducer, 25 is the first insulating layer, 26 is the data transducer, 27 is the WI! 28 is a non-magnetic substrate, 29 is a magnetoresistive element (servo transducer), 31 is a first magnetic pole, 32/fi
2nd insulating layer, 33 is the third insulating layer, 34 is the second magnetic pole, 35 is the data coil, 36 is the storage! ! It is a membrane.

Claims (1)

[Claims] A thin film for a carried servo system having a structure in which a non-magnetic substrate forming a slider, a servo transducer for reproducing servo signals, and a data transducer for recording and reproducing data signals are laminated on the non-magnetic substrate via an insulating layer. A thin film magnetic head for a carried servo system, characterized in that a track width l_8 of a servo transducer satisfies P<l_8≦2P with respect to a track pitch P of a data track.