JPS59140622A - Production of magnetic head core - Google Patents

Abstract

PURPOSE:To improve the workability in inserting a coil winding and to enable formation of a gap to an exact size by forming a joint layer over the entire surface on the joint surface side of a core, removing the joint layer in the part constituting a through-window for inserting the coil winding to expose the core ground surface and adhering the same by glass. CONSTITUTION:A thin film 17 of a ''Sendust'' alloy composed of 6.2wt% Al, 9.6wt% Si, and 84.2wt% Fe is stuck on the joint surface side of base plates 11, 12 composed of high melting glass having high hardness. The thin film 17 is stuck by a high frequency sputtering method in an Ar atmosphere kept at about 10<-2>Torr. SiO2 18 is stuck at about 1,500Angstrom on the film 17. A photoresist 19 is coated thereon except a notched groove 13 and a part 12' and is masked thereon by a photolithographic technique. The base plates are then dipped in an HF- NH4F etching soln. to remove the SiO2 in the groove 13 and the part 12'. Low meling glass 20 is inserted into a hollow groove 14 and after the base plates 11, 12 are sandwiched, the plates are heated in an inert gaseous atmosphere or vacuum to melt and adhere the glass 20 to the part except the groove 13 and the part 12'. A core block assembly 21 is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a core of a magnetic head that performs a-air recording, and more specifically, to a technology for forming a core bond.

[Background technology]

In general, magnetic heads for magnetic recording in VTRs and computers are required to have high recording density and low coercive force characteristics, and have a ferromagnetic core with a magnetic gap of 1 μm or less and good wear resistance. something is needed. Therefore, a ferromagnetic material such as Mn--Zn single crystal ferrite has traditionally been selected as the material, but recently, the recording density is reaching its limit, and a change has begun to be made to Sendust alloy, which has better characteristics.

By the way, in order to manufacture this magnetic head core, as shown in FIG. 1, a pair of core blocks 1.2 are prepared,
The upper corner 8.4 of the butting surface side is made thin so that it has a track width t as shown in Fig. 2, and in order to form a gap of about 111 m or less when butting, either Grind one side and make a notch 5 in one core block l to make a through window through which the coil winding will be pushed through after the core is made, and glue it to the end of the other core block l for temporarily fixing the glass. Many of them were provided with a chamfered recess 6.

However, the above-described head core had the following problems during production. That is, when the core blocks 1.2 of the form shown in FIG. 1 are joined together, as shown in FIG. Not only does it adhere to the gap between the upper corners 3 and 4, but it also adheres to the inner surface of the through window 5', making it difficult to subsequently insert the coil winding. The cause of this problem is that Core Pro 1.2 has very poor wettability with glass 7, and to solve this problem, an oxide film 10.10 is provided on the abutting surfaces. However, at present, no other practical means have been found for joining the core block 1.2 with the glass 7.

[Disclosure of the invention]

This invention was proposed as a result of studies in consideration of the above circumstances. In other words, the present invention is a method for preventing glass from adhering to the inner surface of a through window without losing the adhesiveness between the core block and the glass. This invention involves forming a bonding layer on the entire bonding surface side of the core in advance, and then removing the bonding layer on the inner surface of the through-hole for coil winding through an etching process to expose the core surface. It is characterized by being bonded to glass. Therefore, according to the present invention, as will be clear from the embodiments described later, it is possible not only to simply improve the workability of inserting the coil winding, but also to have the advantage of being able to accurately set the gap size.

[Best mode for carrying out the invention]

FIGS. 4 to 10 show an example of the magnetic field 1. This explains the manufacturing process of docoa. First, the fourth
The figure is a perspective view of substrates 11 and 12 made of high-melting glass with sufficiently high Vickers hardness HV, and a notch groove 13 and a groove 14 for bonding gas are formed on the bonding surface side where they are butted. , gap forming corner 1 of one substrate 11
5 is polished so that it lies on a plane spaced apart by a desired value from the plane in which the abutting surface 16 is included. Therefore, in order to manufacture a magnetic head core, first, as shown in FIG.
．． 2, a sendust alloy thin film 17.17 of each wt% of Si'9.6 and Fe34.2 is deposited. Here, the sendust alloy thin film 17.17 serves as a ferromagnetic core, and 1
The film is deposited to a predetermined thickness by high frequency sputtering in an Ar atmosphere of approximately 0-' TOrr. Next, the sixth
As shown in the figure, an oxide material S10°18.18 is deposited to a thickness of approximately 1500λ on the sendust alloy thin film 17.17.

After that, leaving the cutout grooves 1B and the opposing portions 12' of the substrates 11 and 12, an ultraviolet-sensitive photoresist 19 is applied.
．． 19 like the seventh tooth, masked by photolithography technique, and selectively cut out the notch groove 18 and its opposing portion 12' as shown in FIG. Sin of, is removed. Then, as before, the low melting point glass 20 is inserted into the groove 14.
The low melting point glass 20 is inserted into the cutout groove 13 by sandwiching the substrates 11 and 12 using a crimping jig or the like as shown in FIG. 9, and heating in an inert gas atmosphere or vacuum. and by melting and adhering it to a portion other than the opposing portion 12′,
A core pro-tsuku assembly 21 shown in FIG. 10 is obtained. Finally, this core pro-tsuku assembly 21 was installed at a distance of 10 to several tens of 77 m. By slicing it at intervals of width t, it becomes a magnetic rad core.

In the magnetic head core obtained through the above manufacturing process, the notch groove 13 and its opposing portion 12', which form the inner surface of the coil winding window, are etched so that the bare surface of the sendust alloy thin film 17 is exposed. Melting low melting point glass 2
0 does not adhere, and conversely, other Si, 0.18, 18
It blends well and adheres to the top. Moreover, in this magnetic herad core, the Sendust alloy thin film 17 and the Sin
The film thickness of , 18 can be precisely set by controlling the sputtering speed, and the parent air gear of the sendust alloy thin film.

In the above embodiments, the 810. was formed on the bonding layer, but
In this invention, the same effect can be expected even if it is made of other materials such as Au, O, Tie, etc. Moreover, this invention
In addition to forming the core with a thin film, for example, the core may be reinforced with glass such as Sendust or Permalloy alloy, and the same effect can be obtained.

[Brief explanation of drawings]

Fig. 1 is a front view of a conventional general magnetic hesode core before assembly, Fig. 2 is a plan view thereof, Fig. 8 is a front view of the assembled body, and Figs. FIG. 3 is a perspective view or a front view of each manufacturing process of a magnetic hesodo core showing an embodiment of the invention. 11.12... Cutting board, 12', 18...
Inner surface of through window, 17...Core thin film (Sendal cold gold), 18...
... Bonding layer (Sin, ), 20 ... Adhesive glass, 21 ... Corebrolik assembly. Figure 1 Figure 4 Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 9

Claims (1)

[Claims] Regarding the method of forming a bonding layer on the surface of a ferromagnetic core and bonding it with glass, the bonding layer is formed on the bonding surface of the core (after forming the bonding layer on the entire surface, the bonding layer is formed on the inner surface of the through-hole for coil winding insertion). A method for manufacturing a magnetic hesode core, characterized in that the core is removed by machining or ching to expose the core surface, and then bonded to glass.