JPS6247813A - Double azimuth thin film magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thin film head having a double azimuth angle suitable for use in a VTR, etc.

[Background of the invention]

In response to the increasing density of magnetic recording, efforts are being made to develop high drag mother air recording media and to improve the precision of magnetic heads. As a high-temperature matrix head, head constituent materials such as a magnetic film, gap material, and coil conductor are laminated and patterned on a non-magnetic substrate (hereinafter simply referred to as the substrate) using the IJ printing technique or vacuum evaporation. A thin film magnetic head having an integral structure has been invented (for example, in Japanese Patent Application Laid-Open No. 1986-8
1818, JP-A-58-80121, etc.).

Incidentally, what is mainly used in VTRs and the like is a so-called angular azimuth thin film magnetic head in which the magnetic gap is inclined with respect to the magnetic head & trunk direction. A film magnetic head of this type is, for example, the Yotsu K described in Japanese Patent Application Laid-Open No. 57-55526.

After forming the magnetic film lower core of the spear 1 on the substrate, a portion thereof is removed to form a magnetic gap forming surface. At this point, the inclination angle between the magnetic gap forming surface and the normal to the substrate surface is 5.
-25 degrees (for example, 10 degrees).

This angle corresponds to the azimuth angle. Next, a non-magnetic layer is formed on the magnetic gap forming surface and the removed portion of the magnetic film of the spear 1 to a thickness corresponding to the magnetic head gap distance, and furthermore, the upper core of the magnetic film of the spear 2 is formed on top of the non-magnetic layer. do. Thereafter, processing such as polishing and adhesion of a protective substrate is performed to obtain a thin film magnetic head with an azimuth angle. However, since the magnetic film of Spear 2 is formed on a surface with a large slope of, for example, 80 degrees corresponding to the azimuth angle, the film quality and magnetic properties deteriorate, resulting in large product variations.Also, the substrate is not suitable for mask sputtering. The manufacturing process was complicated, such as by tilting, and there were problems with mass production.

This also applies to a so-called double azimuth thin film magnetic head in which each magnetic gap is inclined at a predetermined angle with respect to the rack direction, as described in Japanese Patent Laid-Open No. 57-141008.

[Purpose of the invention]

An object of the present invention is to solve the problems of the prior art described above, and to provide a double azimuth thin film magnetic head that does not impair the film quality or magnetic properties of the magnetic film, is easy to manufacture, and has a high product yield (and is suitable for mass production).

[Summary of the Invention] In order to achieve this object, the present invention forms inclined surfaces corresponding to the respective azimuth angles at least at positions corresponding to the magnetic gap portions of the lower core provided on both the front and back surfaces of the substrate. The feature is that a magnetic gap is formed so as to maintain the angle of this inclined surface.

[Embodiments of the invention]

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

, 1' Fig. 1 is a perspective view showing an embodiment of the double azimuth thin film magnetic head according to the present invention, in which 1 is a non-extrusion flat substrate and has a structure in which a pair of thin film heads are respectively formed on the front and back sides of the substrate. It is. Hereinafter, the head on the topsoil side of Figure 1 will be referred to as Head 1, the head on the bottom side of the bottom will be referred to as Head 2, and substrate 1.
The core closer to the core is called the lower core, and the one farther away is called the upper core. 20.21 is the lower core of the spear 1 head and the spear 2 head, respectively, and 50.51 and 30.31 are the gap and upper core of the spear 1 head and the spear 2 head, respectively. 4 is a signal coil for recording or reproducing signals, and 6 is an insulating material between the eyebrows (the coil for the second head, the material between the eyebrows is omitted).

In the same figure, the rain lower core 20.21 is a flat substrate IK.
On the other hand, the angles θ corresponding to the azimuth angles and the respective gaps 50 and 51 are arranged so that they are not parallel to each other. This inclined surface having an azimuth angle θ can be obtained by forming a magnetic film on the flat substrate 1 by a method such as hattering, vapor deposition, or plating, and then lapping or cutting with a cutting tool. While keeping the substrate 1 flat on the upper surface of the lower core 20.21 having an inclined surface with an azimuth angle θ, the gear lug material 50.51, the signal coil 4, the insulating layer 6, the upper core 30.3+, etc. are attached to the ICg structure. Similar film formation and photoetching are sequentially repeated to form a layer. Although the windows and coils are shown as having one turn, they may have multiple turns.

In addition, since the azimuth angle is generally 5 to 25 degrees, on the gently sloped surface of the lower core 2 as shown in the figure, there is no problem with step coverage, and the upper core so, st formed on the slope There is no significant difference between the magnetic film and the magnetic layer formed on a flat surface.

Upper core 30.31? : After forming, a protective film (
(not shown) and chip shaping to obtain a double azimuth thin film magnetic head.

Gap distance between spear 1 head and spear 2 head (center 1i7)
interval) tG is the horizontal synchronization signal (TV horizontal running IF Iwao 1
It is designed to be n times or n-7 times the distance corresponding to the main duty). In the conventional method of bonding two heads together, it is not only difficult to match the center widths of the trunk widths of head 1 and head 2, but also because the bonding resin or low-melting glass is used. Is it possible to keep it constant, and the gear spacing between 1 head and 2 hects is actually lG'?
: It is difficult to form with high precision, so it was necessary to individually correct the signal delay circuit.

On the other hand, in the present invention, since the heads are formed on the front and back sides of the substrate 1, the gap distance IQ depends on the thickness td of the substrate 1 and the thickness of the lower side cores 20 and 21. Therefore, the thickness t of the substrate 1
Both d and the thickness of the lower core 20°21 can be adjusted to an accuracy of several μm, and the azimuth angle can be formed by cutting the film surface of the lower core magnetic material with a cutting tool, etc., so that the gap can be reduced. This means that the interval 'G can be formed with high precision. Therefore, by increasing the precision of the gap interval tG, adjustment of the delay circuit becomes unnecessary, and an inexpensive fixed delay circuit can be used.

In this embodiment, an example is shown in which the lower core 20.21g is formed on the entire surface, but it may be patterned to form a closed bus path with the lower core 50.31. It is also possible to change the track widths of the two heads to form heads that are compatible with the tilting mode, long-time mode, etc., respectively.

,? FIG. 2 is a perspective view of an example in which a large number of chips are developed on a wafer in order to mass produce the double azimuth thin film magnetic head according to the present invention shown in FIG. 1, in which 1 is a substrate, 20.
21 is the lower core, 30°31 is the upper core, 4 is the coil,
7 is a cutting line for chipping.

In the same process, a large number of magnetic films with inclined planes, which will become the lower core 20. do. Cut this wafer at line 7
A high-speed riser (not shown) is used to cut the magnetic head along the same direction and separate the head chips into individual head chips to obtain a large number of double azimuth thin film magnetic heads.

, IF3 is a perspective view of Oni Vll, in which a large number of chips are developed on Uni 1 in order to mass produce the double azimuth thin film magnetic head according to the present invention shown in Figure 1. It is formed in the lower core of the substrate, and 1.2Q, 21 and 7 indicate the same parts as in Figure 2, and 201° and 211 indicate the lower core of the reverse azimuth with respect to the lower core 20.21.

In FIG. 9, the inclined surfaces corresponding to the azimuth angle and the reverse azimuth angle formed on the lower core are formed by lapping or cutting pressure with a cutting tool after forming a mother film on the substrate 1, as in FIG. According to this example, both azimuth angle and reverse azimuth angle? It can be mass-produced on the same wafer.

, i-4 is a perspective view of three examples in which a large number of chips are developed to mass-produce the double azimuth thin film mount according to the present invention, in which 1 is a non-magnetic substrate 20, 21 is a lower core,
7 is a cut tfrd, and 80 and 81 are nonmagnetic films. In addition,
The upper core, coil, etc. are omitted.

In the figure, a substrate 1 has a flat surface, and a nonmagnetic film 80 that is easy to machine, such as cutting, is formed on both the front and back surfaces.
．． 81 respectively.

The non-magnetic film 80.81 is CuAz, SUB, Si
o, *Tie, or a glass material, a ceramic material, etc., which is formed by geometric processing to form an inclined surface corresponding to the azimuth angle, and a magnetic film 21 is formed on the lower core 2. It is.

According to this, the azimuth angles of the nonmagnetic films 80, 81 are transferred and maintained on the upper surface of the lower core 20, 21, and a double azimuth thin film magnetic head can be obtained by the same method as described above.

Figure 5 shows a double azimuth thin film magnetic head W according to the present invention.
*This is a perspective view of a multi-chip structure in which a large number of chips are deployed on Ueno for production. 20° 21 is the lower core, 7 is the cutting line, 11 is the non-magnetic substrate, and the other components are It is omitted.

In the same figure, the substrate 11 is made of the above-mentioned non-magnetic material that is easy to machine, and is mechanically machined on both the front and back surfaces so that it has an inclined surface corresponding to the azimuth angle. This is to form a magnetic film that will become the core 20°21. According to this, the azimuth angle of the substrate 11 is transferred and maintained on the upper surface of the lower core 20.21 as in the above example,
Thereafter, a double azimuth thin film H1fi head can be obtained in the same manner.

Figure 6 shows a double azimuth thin film head according to the present invention.
It is a perspective view of an example in which a large number of chips are developed on a wafer for production, in which 1, 20, 21 and 7 indicate the same parts as above, and 28 and 29 are gap forming positions.

In the figure, partial inclined surfaces corresponding to the azimuth angle are formed at gap forming positions 28 and 29 of the lower core 20 and 21 formed on both the front and back surfaces of the flat substrate 1, respectively. Since the connecting part between this inclined surface part and the other flat part has an appropriate taper so as to be continuous, there is no problem with step coverage in the magnetic film forming process of the upper core (not shown) that will be formed later. .

In addition, in the same figure, on a flat surface, the gap forming position 28.2 of the lower core 20.21 formed on the flat surface is
Although the partially inclined surface portion was machined in 9, the partially inclined surface portion may be machined by force at the gap forming position of the substrate 1.

〔Effect of the invention〕

As explained above, according to the present invention, the slopes corresponding to each azimuth angle can be made gentle, and the core can be formed without impairing its magnetic properties, resulting in high manufacturing yield and ease of mass production. A good double azimuth thin film magnetic head can be obtained, and the problems of the prior art described above can be solved and a double azimuth thin film magnetic head with excellent functions can be provided.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an embodiment of the double azimuth thin film magnetic head according to the present invention, and Figure 2 is a perspective view of an example in which a large number of chips of the double azimuth thin film magnetic head according to the present invention are developed on a wafer. The figure is a perspective view of an example in which a large number of double azimuth thin film magnetic head chips according to the present invention are developed on a wafer together with thin film magnetic heads having opposite azimuth angles, and Figure 4 is a double azimuth thin film according to the present invention. Figure 1, 175 is a perspective view of an example in which a large number of magnetic head chips are developed on a wafer, and Figure 175 is a perspective view of four examples in which a large number of double azimuth thin film magnetic head chips according to the present invention are developed on a wafer. FIG. 2 is a perspective view of a large number of double azimuth thin film magnetic heads according to the invention developed on a chimp wafer. 1.11...Nonmagnetic substrate, 20.21, 201°2
11...Lower core, 30.31...Upper core, 4.
...Coil, 5...Gap material. ,・') Attorney 1 Masaru Ogawa (Male 1st 20th Term)

Claims (1)

[Claims] In a double azimuth thin film magnetic head in which a lower core, a gap material, an insulating material, an upper core, etc. are sequentially laminated on both the front and back surfaces of a non-magnetic substrate, at least the magnetic gap forming portions of the front and back lower cores are coated with the substrate. A double azimuth thin film magnetic head characterized in that it has an inclined surface corresponding to an azimuth angle.