JPS63112809A - Magnetic head - Google Patents

Abstract

PURPOSE:To facilitate production of a magnetic head consisting of a thin magnetic metallic film as it main core and to improve the yield thereof by using mica ceramics as a substrate material. CONSTITUTION:This magnetic head is constructed by sandwiching both faces of the thin magnetic metallic film 1 which is the main core by the mica ceramics 2. A thin film of an amorphous alloy or 'SENDUST(R)' is used as the film 1. In this embodiment, the thin amorphous alloy film 1 essentially consisting of Co is formed by sputtering on both faces of mica ceramics substrates 2. Since the mica ceramics are used as the substrates for vapor deposition of the film 1 which is the main core and a holding material thereof, the precise cutting and working are facilitated by the good workability thereof. Said ceramics have the coefft. of thermal expansion approximate to the coefft. of thermal expansion of the amorphous alloy and thin 'SENDUST(R)' film and, therefore, the deterioration in the characteristic by the influence of magnetorestriction, etc., is decreased and the good magnetic characteristic are exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head suitable for recording and reproducing high frequency signals at high density on a high coercive force magnetic recording medium such as a VTR or digital audio.

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 Bs of 4000 to 50.
Since it is about 1,000 Gauss, there is a limit to the strength of the recording magnetic field that can be obtained, and if the coercive force Hc of the magnetic recording medium exceeds 1,000 Oersteds, recording becomes insufficient.

On the other hand, Fe-A7 is a generic name for metallic magnetic materials! Magnetic heads using crystalline magnetic alloys such as -3i alloy (referred to as sendust) and Ni-1'e alloy (permalloy), or amorphous alloys generally have a higher saturation magnetic flux density than ferrite materials. Although it has excellent features such as low sliding noise, it has the drawbacks of being difficult to process, resulting in poor yield and high cost.

Problems to be Solved by the Invention In particular, when a metal magnetic thin film is used as the main core, it is usually formed on a magnetic or non-magnetic substrate by vapor deposition or sputtering, and then made of the same material as the substrate. It is processed and made into a head by adhering a metal magnetic thin film between them. However, strict conditions are required for this substrate. For example, the thermal expansion coefficient should be close to that of the metal magnetic thin film so as not to deteriorate the magnetic properties of the metal magnetic thin film, it should have good workability, and it should wear moderately when sliding with the tape and not cause uneven wear. Materials that fully satisfy these conditions are extremely limited, and ferrite or titanate ceramics have been used in the past, but they have advantages and disadvantages, and the selection of an appropriate substrate material is an important issue. It had become.

Means for Solving the Problems The present invention attempts to solve the above problems by using mica ceramics as the substrate. Mica ceramics, which have been developed in recent years as free-cutting ceramics, have a structure in which crystal grains of mica, particularly fluorophlogopite, are hardened with a binder such as glass. . [Functional materials 198
6. June issue.

P16] The following are its characteristics: (Precise processing is possible with 11 metal tools.

(2) Self-lubricating property with a small coefficient of 7.

(3) Excellent heat resistance.

(4) Thermal expansion coefficient is close to that of metals (can be used in combination with metals).

(5) Excellent corrosion resistance.

etc. The above characteristics are extremely desirable properties for a substrate material of a magnetic head having a main core made of a metal magnetic thin film.

By using mica ceramics as the working substrate material, it is easy to manufacture magnetic 7F with a metal magnetic thin film as the main core, improving yield and greatly reducing manufacturing costs. It is possible to provide a good heel/7d with less uneven wear.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a magnetic head showing the structure of the present invention. It has a structure in which mica ceramics 2 sandwich both sides of a metal magnetic thin film 1, which is the main core.

A specific method of manufacturing this magnetic head will be shown below.

Example 1 As shown in FIG. 2, an amorphous alloy thin film 1 containing CO as a main component was deposited on both sides of a mica ceramic substrate 2 with a thickness of 1 mm.
was formed by sputtering to a thickness of 21 μm, and a 0.5-1 μm thick SiO2 film (
(omitted in the drawing). Furthermore, we prepared mica ceramic substrates similar to those described above with glass layers (omitted in the drawing) having a thickness of 3 μm formed on both sides. (The layers are formed only on one side) are laminated alternately, heated and pressurized at a glass fusing temperature to melt and bond the glass layers to form a laminated block 3.
get. Next, it is cut according to a predetermined azimuth angle as shown by the dotted line in FIG. 3, and a pair of core halves 4, as shown in FIG.
Get 4゛. After winding grooves are formed on the core half 4 on the - side, the abutting surfaces of the pair of core halves 4, 4' are polished, and Si is used as a gap material to obtain a predetermined gap length.
A thin film of O2 and bonding glass is formed and bonded in an electric furnace to obtain the gap forming bar 5 shown in FIG. Thereafter, the slicer 6 shown in FIG. 6 is obtained by cutting according to the lamination pinch as shown by the broken line, and the slicer 6 shown in FIG. 1 is obtained by cutting according to the winding groove pitch as shown by the broken line. You will get a head chip. Thereafter, the head chip is bonded to a base plate, and the magnetic head is completed through processes such as curving the tape sliding surface, polishing, and winding.

Example 2 Instead of the amorphous alloy thin film 1 of Example 1, a sendust thin film with a thickness of 21 μm was formed on both sides of the mica ceramic substrate by vacuum deposition. Otherwise, a head is manufactured using the same steps as in Example 1.

Effects of the Invention As described above, the present invention uses mica ceramics as the evaporation substrate of the metal magnetic thin film as the main core and as the holding material.
Precise cutting as shown in the figure is easy. In addition, the coefficient of thermal expansion is about 11 x 10'61/, and the coefficient of thermal expansion of amorphous alloys and Senges 1 to thin films is 12 to 13 x 1 (1'
Since it is close to 61/k, it exhibits good magnetic properties with little characteristic deterioration due to the effects of magnetostriction and the like. In addition, it has excellent heat resistance, allowing heating to around 600°C, allowing the use of glass for bonding, and excellent corrosion resistance, making it possible to manufacture heads with high reliability. It is. Furthermore, when sliding with the tape, it has self-lubricating properties because it contains mica, and has moderate abrasion resistance, so it can maintain a good sliding surface without uneven wear. This head has many characteristics such as high processing yield, can be manufactured at low cost, has good characteristics, and can be manufactured with high reliability.

[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 perspective views of a head illustrating a method of manufacturing a head in an embodiment of the present invention. 1...Metal magnetic thin film, 2...Mica ceramics, 3...Laminated block, 4, 4' ・
... Core half-rest pair, 5 ... Gasoff forming bar, 6 ... Slice bar. Name of agent: Patent attorney Toshio Nakao Haka 1 and 2
Ward] Otsu-ha Figure 4 Figure 5 Figure 6

Claims (2)

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