JPH01191308A - Magnetic head - Google Patents

Abstract

PURPOSE:To widely decrease a magnetic flux to leak from the side surface of a head and to improve head efficiency by holding the both surfaces of a metallic magnetic thin film, which is a main core, with a superconductor. CONSTITUTION:The both surfaces of a metallic magnetic thin film 1, which is the main core, are held by a superconductor 2. For example, on the both surfaces of a superconductor substrate 2, whose thickness is 1mm, an amorphous alloyed thin film 1 is formed and on the film, an SiO2 film is formed as a protecting layer. Further, on the both surfaces of the superconductor substrate, a glass layer, whose thickness is 3mum, is prepared. Then, the three pieces of the former and the four pieces of the latter are alternatively laminated and adhered at a glass fusion temperature. Then, a laminating block is obtained. Thus, the side surface of the magnetic head is covered with the superconductor and the leakage of the magnetic flux in the side surface of a magnetic path, which is composed of the metallic magnetic thin film, can be extremely decreased by a Meissner effect. Then, the efficiency of the magnetic head can be extremely improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head suitable for recording high frequency signals on a high coercive force magnetic recording medium used for VTRs, digital audio, and the like.

Conventional Technology It is well known that it is advantageous to increase the coercive force Hc of a magnetic recording medium in high-density magnetic recording and reproducing devices such as VTRs and digital audio. A strong magnetic field is required to record. However, the ferrite material currently widely used in magnetic heads has a saturation magnetic flux density of about 4,000 to 5,000 Gauss, so there is a limit to the strength of the recording magnetic field that can be obtained, and the coercive force of the magnetic recording medium is about 1,000 Oe or more. This has the disadvantage that records are insufficient.

On the other hand, Fe-Aj! is a generic name for metallic magnetic materials. Magnetic heads using crystalline magnetic alloys such as -St gold alloy sendust), Ni-Fe alloys (permalloy), or amorphous alloys generally have a higher saturation magnetic flux density than ferrite materials, and Although it has an excellent feature of low sliding noise, it has the drawbacks of being difficult to process and having a low yield, resulting in high costs.

In particular, when a metal magnetic thin film is used as the main core, it is usually bonded onto a suitable substrate, polished to a predetermined thickness, and then bonded between similar substrates to sandwich the metal magnetic thin film, and then processed. Becomes a head.

Problems to be Solved by the Invention However, in high-density recording, the track width tends to become narrower and narrower, and as the thickness of the metal magnetic thin film that defines it becomes thinner, the efficiency of the magnetic head with the above structure decreases. However, it has the disadvantage that the desired output cannot be obtained.

Means for Solving the Problems The present invention attempts to solve the above problems by using a superconductor as a substrate. By using a superconductor as a substrate, the sides of the magnetic head are covered with the superconductor, and the Meissner effect can significantly reduce the leakage of magnetic flux on the sides of the magnetic path made up of the metal magnetic thin film. Head efficiency can be significantly improved.

By using a superconductor as a working substrate material, it becomes easy to manufacture a high-performance magnetic head whose main core is a metal magnetic thin film.

Embodiment FIG. 1 is a perspective view of a magnetic head showing the structure of the present invention. It has a structure in which superconductors 2 sandwich both sides of a metal magnetic thin film 1, which is the main core. A specific method for manufacturing this head will be shown below.

Example 1 As shown in FIG. 2, an amorphous alloy thin film l containing CO as a main component was formed by sputtering on both sides of a superconductor substrate 2 with a thickness of 1 fl to a thickness of 21 μm. A SiO2 film (not shown in the drawing) with a thickness of .5 to 1 μm is formed. Furthermore, we prepared superconductor substrates similar to those described above with glass layers (omitted in the drawing) having a thickness of 3 μm formed on both sides, 3 of the former and 4 of the latter (however,
Glass layers are formed on only one side of the substrates to be laminated on the outside) are alternately laminated and bonded at a glass fusing temperature (500° C.) to obtain a laminated block 3. Next, it is cut according to a predetermined azimuth angle as shown by the dotted line in FIG. 3 to obtain a pair of core halves of 4.4° as shown in FIG. After winding grooves are formed on one of the cores and half body 4, the abutting surfaces of the core halves 4° and 4° are polished, and then a thin film of SiO2 and adhesive glass is formed as a gap material to obtain a predetermined gap length. The gap forming bar 5 is obtained by heating (500° C.) in an electric furnace and bonding. Thereafter, the slicer 6 shown in FIG. 6 is obtained by cutting according to the lamination pitch as shown by the broken line, and the head as shown in FIG. 1 is obtained by cutting according to the winding groove pitch as shown by the broken line. You get chips. The head chip is adhered to a base plate, and the magnetic head is completed through processes such as curved surface processing and polishing of the tape sliding surface, and winding.

In the process described above, a superconductor is used as the evaporation substrate and holding material for the metal magnetic thin film that is the main core, so the Meissner effect can significantly reduce the magnetic flux leaking from the sides of the head, thereby improving head efficiency. In addition, due to the same effect when sliding with the tape, it has an appropriate gap, so it has many equivalent features that can maintain a good sliding surface with less occurrence of uneven wear, and magnetic properties. can produce good heads.

Example 2 Instead of the amorphous alloy thin film 1 of Example 1, two Sendust thin films were deposited on both sides of the superconductor substrate 2 by vacuum evaporation.
It is formed to a thickness of 1 μm. Otherwise, the head can be manufactured using the same steps as in Example 1. In the case of this example, due to the heat resistance of the sendust thin film, the heating temperature for obtaining the laminated block and the gap forming bar can be about 800°C, and adhesive glass with a high fusing temperature (800°C) was used.

The magnetic properties and wear characteristics of the magnetic head thus obtained are as good as in Example 1.

In the above examples, as the superconductor material, for example, a so-called room temperature superconductor is used, or a material whose superconducting critical temperature is between room temperature and the boiling point of liquid nitrogen temperature is used and cooled with liquid nitrogen. (not shown), or cooled with liquid helium using a material whose superconducting critical temperature is below the boiling point of liquid nitrogen temperature (not shown). An example of a room-temperature superconductor is strontium (S) as a composition.
There are ceramic oxides containing barium (Ba), indium (Y) and copper (Cu) in a ratio of 1:1:1:3, respectively. As an example of its production method, 5rCO' is used as a starting material.

Predetermined amounts of powders of BaCO3, Y2O3, and CuO are mixed, pulverized, and fired in air at 920° C. for 5 hours. This firing and crushing process is repeated three times to improve homogeneity. After cold compression molding the mixed powder treated in this way, it is produced by firing in air at 1000° C. for 5 hours and slowly cooling.

Effects of the Invention As described above, the present invention uses a superconductor as the deposition substrate and holding material for the metal magnetic thin film that is the main core.
The Meissner effect can significantly reduce the magnetic flux leaking from the side of the sand head, improving head efficiency, and the same effect creates an appropriate gap when sliding with the tape, reducing uneven wear. It has many equivalent features that can maintain a good sliding surface with less generation, and a head with good magnetic properties can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of the magnetic head of the present invention, and FIG.
6 to 6 are explanatory diagrams illustrating a method of manufacturing a head in an embodiment of the present invention. 1...Metal magnetic thin film, 2...Superconductor, 3...Laminated block, 4,4°...
Core half-rest pair, 5...Gasoff formation bar, 6...
...Slice bar. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 1 Figure 2 Figure 3 Figure 84 Figure 11 Kaihei 1-191308 (4)

Claims (2)

[Claims] (1) A magnetic head having a structure in which both sides of a metal magnetic thin film, which is the main core, are sandwiched between superconductors. (2) Claim No. 1, characterized in that the metal magnetic thin film is an amorphous alloy or a sendust thin film.
) The magnetic head described in section 2.