JPS63127408A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To make a gap layer flat and eliminate the azimuth loss to improve the reproduced output by connecting leading-out terminals, which are buried in a substrate, in parallel with a bias conductor layer to which an MR element is directly joined. CONSTITUTION:Leading-out terminals 21A-21C through which a sense current is supplied to a reproducing MR element 4 are buried in an insulating magnetic substrate 1, and a bias conductor layer 3 to which the MR element 4 is directly joined is connected in parallel to surfaces of these terminals. A lower magnetic pole layer 7 is laminated on the MR element with a reproducing gap layer 6 between them to form a reproducing function part 2, and a recording function part 11 is formed with the similar constitution. Since the reproducing gap layer 6 and a recording layer 12 which conventionally have stepped and curved surfaces have flat surfaces, the occurrence of gap azimuth loss is eliminated at the time of reproducing to improve the reproduced output.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention provides a composite thin film magnetic head of a separate recording/reading type using a magnetoresistive element for reproduction, in which an extraction terminal for supplying a sense current to the magnetoresistive element is connected to a substrate. The structure is such that the magnetoresistive element is buried in the surface and connected to the bias conductor layer to which it is directly bonded, and the read gap layer and the recording gap layer that are successively laminated on the magnetoresistive element are flattened and This is an attempt to improve reproduction output by eliminating gap azimuth loss.

[Industrial application field]

The present invention relates to improvements in thin-film magnetic heads used in magnetic tape devices, magnetic disk devices, etc., and more particularly to a composite thin-film magnetic head of a separate recording/reading type using a magnetoresistive element for reading.

A composite thin-film magnetic head with separate recording/reproduction type that integrates a magnetoresistive element for reproduction and an inductive magnetic head for recording has a high recording speed because the reproduction output does not depend on the media speed and a relatively large output can be obtained. It has features that are extremely advantageous for track reproduction, and in recent years, it has been expected to be a head that can replace the conventional inductive thin film magnetic head for both recording and reproduction in response to the demand for higher track densities. Accordingly, in order to improve the reproduction characteristics, it is necessary to increase the precision of the reproduction gap.

[Conventional technology]

A conventional composite thin-film magnetic head using a magnetoresistive element (hereinafter abbreviated as MR element) with separate recording/reproducing type is made of an insulating magnetic head made of, for example, Ni-Zn ferrite, as shown in the cross section of the main part in Fig. 4. A bias conductor layer 3 made of Ti and a Ni-Fe layer directly bonded to the bias conductor layer 3 are formed on the substrate 1.
An MR element 4 made of an alloy film, a lead terminal 5 for supplying sense current to the element 4 and the bias conductor layer 3, and Al2O
A reproducing function section 2 has a reproducing function section 2 in which a reproducing gap layer 6 made of Ni--Fe alloy film, etc., and an upper shield layer 7 consisting of a Ni--Fe alloy film are laminated in this order, and furthermore, the upper shield layer 7 is used as a lower magnetic pole layer, and the upper surface thereof is coated with A 1 zOx. An interlayer insulating layer 13 made of thermosetting resin, Cu
It consists of a recording function section 11 in which a thin film coil 14 consisting of a thin film coil 14 and an upper magnetic pole layer 15 consisting of a Ni--Fe alloy film are laminated in this order, and the surface thereof is coated with an insulating protective film 16.

Information can be recorded and reproduced separately on the opposing magnetic recording medium 17 by the tips of the upper and lower magnetic poles and the MR element.

A shunt bias method is adopted as a biasing method for the MR element 4, and a lead terminal 5 for supplying a sense current to the MR element 4 and the bias conductor layer 3 is used as shown in FIG. For the purpose of reducing noise, there are three terminals, 58, 5B, and 5c, with low electrical resistance, and between terminals 5A and 5B and between terminals 5B and 5C.
Signal detection is performed by differentially amplifying the output between the two.

[Problem that the invention seeks to solve]

By the way, in a composite thin film magnetic head using a conventional MR element, the electrical resistance of the lead terminals 5A, 5B, and 5c for supplying current to the MR element 4 and the bias conductor layer 3 is reduced to reduce thermal noise during reproduction. Therefore, the thickness of the film should be 0.5 μm or more, and the lead terminals 5A, 5B
, 5c are provided on the MR element 4, as shown in FIG. 6, enlarged from the medium 17 side, in order to flow a sense current parallel to the length direction of the MR element 4.

Therefore, a thin reproduction gap jLf6 of about 1 μm thick is sequentially laminated on the upper surface (in order to obtain a high linear recording density).
, the upper shield layer 7, which also serves as the lower magnetic pole layer, the recording gap layer 12, etc., inherit the level difference in the arrangement of the lead terminals 5A, 5B, and 5c, and the reproduction gap layer 6 and the recording gap layer 12 have a flat gap. There is an inconvenience that this does not happen. For this reason, there is a drawback that gap azimuth loss occurs particularly during reproduction, resulting in a reduction in reproduction output.

In view of the above-mentioned conventional drawbacks, the present invention improves the arrangement configuration of the lead-out terminals for current supply to the MR element and the bias conductor layer, flattens the read gap layer and the write gap layer, and thereby reduces the gap azimuth that occurs during playback. The object of the present invention is to provide a novel composite thin-film magnetic head of separate recording/reproducing type that eliminates loss.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention has an extraction terminal for supplying a sense current to the reproducing MR element directly connected to the bias conductor layer, which is buried in the bias conductor layer area of the insulated magnetic substrate with its upper surface exposed. A bias conductor layer to which the MR element is directly bonded is connected to the surface of the reproducing function section, in which a lower magnetic pole layer which also serves as an upper shield layer is laminated in order through a reproducing gap layer, and a lower magnetic pole layer is formed on the lower magnetic pole layer. The structure includes a recording function section in which a recording gap layer, an interlayer insulating layer, a thin film coil, and an upper magnetic pole layer are laminated in this order, and an insulating protective layer is coated on the upper surface of the recording function section.

[Effect]

In the composite thin film magnetic head of the present invention, the lead-out terminal for current flow connected to the four-layer bias layer to which the MR element is bonded is buried in the bias conductor layer area of the insulating magnetic substrate with the top surface exposed. Therefore, the bias conductor layer and the reproduction MR element disposed on the surface become flat,
There are no steps. Therefore, the reproduction gear knob layer, the upper shield layer, and the recording gap layer on the lower magnetic pole layer that also serves as the upper shield layer are flattened, and the problem of gap azimuth loss during reproduction is resolved. be done.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

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

In the figure, reference numeral 1 denotes an insulated magnetic substrate made of Ni-Zn ferrite or the like, and a reproduction M that is directly bonded to a bias conductor layer 3, which will be described later, is placed on the bias conductor layer area on the substrate 1.
Output terminals 21A, 21B, and 21G made of Cu or the like and which supply a sense current to the R element 4 are buried with their upper surfaces exposed.

The method of arranging the extraction terminals 21A, 21B, and 21C is as follows:
A groove is formed in advance in the area where the terminal is to be formed on the substrate 1 by laser cutting, etc., and a conductive film made of Cu or the like is embedded in the groove by sputtering, polishing, etc., and the film surface is aligned with the substrate. Output terminals 21^, 21B, and 21C that are flush with the first surface can be provided.

The lead terminals 21A, 21B, 21C: M made of a Ni-Fe alloy film are placed on the substrate 1 whose upper surface is exposed.
A bias conductor layer 3 made of Tt to which an R element 4 is directly bonded is provided, and as shown in FIG.
8, 21B, and 21C.

Moreover, on the MR element 4, Aj! The reproduction function section 1 is constructed by laminating a thin film reproduction gap layer 6 made of zot or the like and an upper shield layer 7 made of a Ni--Fe alloy film in this order.

Further, the upper shield layer 7 is used as a lower magnetic pole with A on its upper surface.
An interlayer insulating layer 13 made of thermosetting resin, a thin film coil 14 made of Co, and an upper magnetic pole 15 made of a Ni-Fe alloy film are interposed through a recording gear layer 12 made of N203 or the like.
It has a composite structure including a recording function section 11 in which layers are sequentially stacked, and an insulating protective film 12 is coated on the surface thereof.

As described above, in the head configuration of the present invention, as shown in FIG. 3, which shows the magnetic pole tip section enlarged from the medium 17 side,
The lead terminals 218, 21B, 21C7 < board 1
Since the structure is such that the bias conductor layer 3 to which the MR element 4 is directly bonded is connected to the MR element 4 while being buried thereon, a step is not created on the surface where the reproduction gap layer 6 is provided by the lead-out terminal as in the conventional case. The resulting inconvenience is eliminated, and the reproducing gap N6 and recording gap layer 12, which are sequentially provided on the MR element 4, are no longer required.

〔Effect of the invention〕

As is clear from the above description, according to the separate recording/reading type composite thin-film magnetic head according to the present invention, the surface on which the reading gap layer is provided is flattened, and the reading gap layer and the recording gear layer are flattened. Therefore, the problem of gap azimuth loss occurring during reproduction is resolved, and the excellent effect of improving reproduction output characteristics is achieved. In addition, it becomes easier to narrow each recording/reproducing gap length, making it possible to achieve higher linear recording density, etc.
It is extremely advantageous to apply this type of thin film magnetic head.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part showing an embodiment of a thin film magnetic head according to the present invention, FIG. Fig. 3 is an enlarged plan view showing the magnetic pole tip of the thin film magnetic head according to the present invention from the medium side, Fig. 4 is a sectional view of a main part for explaining a conventional thin film magnetic head, and Fig. 5 is a conventional thin film magnetic head. FIG. 6 is a partially enlarged perspective view for explaining the lead-out terminal of the head, and FIG. 6 is an enlarged plan view showing the magnetic pole tip of a conventional thin-film magnetic head from the medium side. 1 to 3, 1 is an insulated magnetic substrate, 2 is a reproduction function section, 3 is a high-ass conductor layer, 4 is an MR element, 6 is a reproduction gap layer, 7 is an upper shield layer (lower magnetic pole layer), and 11 is a Recording function section, 12 is a recording gap layer, 13 is an interlayer insulating layer, 14 is a thin film coil, 15 is an upper magnetic pole layer, 16 is an insulating protective layer, 17 is a magnetic recording medium, 2
1A and 218.21C indicate lead terminals, respectively.

Claims (1)

[Claims] A reproducing magnetoresistive element (4) directly bonded to a bias conductor layer (3) on an insulating magnetic substrate (1), and lead terminals (21A, 21B, 21C) for energizing these elements; A reproducing function section (2) in which an upper shield layer (7) which also serves as a lower magnetic pole layer is laminated in order through a reproducing gap layer (6), a recording gap layer (12) on the lower magnetic pole layer (7), and an interlayer Insulating layer (13), thin film coil (14) and upper magnetic pole layer (1
In the composite head configuration, the lead terminals (21A, 21B, 21C) are formed by an insulating magnetic substrate (21A, 21B, 21C). A thin film magnetic head characterized in that it is embedded in the bias conductor layer (3) arrangement region of (1) and connected to the bias conductor layer (3).