JPS6233308A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To improve the mechanical dimension accuracy by providing plural groove parts to a metallic magnetic substance with a prescribed interval perpendicularly to an operating gap formed by the metallic magnetic substance of a head block in a depth reaching a nonmagnetic part exposed to the upper face and packing the nonmagnetic material t the groove part. CONSTITUTION:The nonmagnetic part is given to a tip face of a ferrite being one main magnetic path of a couple of core halves, the metallic magnetic member 4 is provided on the ferrite and glass to form a composite core. A gap face 8 is formed by smoothing and polishing the metallic core, the glass and the frrite into the same face from one end face of the composite core, the gaps of a couple of the composite core halves are sticked by adhering a nonmagnetic substance, the gap member of the glass nearby is molten to constitute a head block H. Further, a vertical cut groove 5 is provided to the metallic magnetic substance to split the substance into plural pieces having a track width, and a nonmagnetic substance such as SiC, alpha-Fe2O3 or glass is adhered into the cut groove from the track end by sputtering, vapor-deposition or electric plating. Thus, the deterioration of the magnetic property of the core or the adverse effect to the mechanical dimension accuracy is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head that is effective when used in a magnetic recording/reproducing device using a high coercive force recording medium.

BACKGROUND OF THE INVENTION In recent years, the density of magnetic recording and reproducing apparatuses represented by conventional VTRs has been increasing rapidly. For this reason, the track width of the magnetic head used is sometimes as narrow as about 10 microns. Furthermore, metal materials such as sendust and amorphous, which have a high saturation magnetic flux density, are often used as core materials. As described above, a head with a narrow track width and a metal core is subject to severe wear due to sliding with the magnetic tape, resulting in a short head life. For this reason, it is common to have a structure in which the sides of the head track width are reinforced to increase the contact width with one magnetic tape.

FIG. 2 shows an example of a conventional head viewed from the front.

In other words, Figure A shows that as one of the reinforcements at the track end,
In the case of a single ferrite head, glass αη was fused from both sides of the track Oe.

In addition, the metal head made of Sendust alloy or amorphous alloy shown in Figure B was reinforced by adhering a thin plate of glass or ceramics to the side surface of the 0 second head track via an epoxy resin layer.

Problems to be Solved by the Invention The configuration of the conventional magnetic head described above has the following problems. One of the problems is when the metal core track ends are reinforced by glass welding. In other words, what is important during welding is that the coefficient of thermal expansion (α) of the core material and the glass material match, and when the core material is sendust, α = approximately 170X10, and the difference in α is the most important. Even if you select a similar glass, α=150X10
That's about it.

Due to these α differences, stress is inherent in the glass during welding, causing cracks, chips, or omissions in the glass, and highly accurate track edge reinforcement cannot be achieved.

In addition, when an amorphous alloy is used as the core material, the crystallization temperature of the amorphous is as low as around 550°C, so a low melting point glass containing a large amount of PBO is used as the welding glass, and the P'bO The amorphous alloy and the amorphous alloy form an interdiffusion layer at the fused interface, and a portion of the amorphous alloy is penetrated by the glass, which reduces the track width.

Furthermore, due to the sliding of the magnetic tape, the low melting point glass creates a step and is located at a position lower than the track portion, causing problems such as adhesion of magnetic tape powder and damage to the magnetic tape.

For this reason, conventional heads made of sendust or amorphous alloy that use a metal core in the track part often have a structure in which a glass or ceramic i-plate is bonded to the track end via an epoxy resin layer. However, this method has low reliability in terms of weather resistance, and chipping tends to occur near the resin layer, which causes problems such as a decrease in track width, deterioration of single-head characteristics, and damage to the magnetic tape. Ta.

Means for Solving the Problems The present invention has a non-magnetic material exposed on the top surface and fused to a part of the tip of a ferrite core to form the non-magnetic part, and the non-magnetic part and the ferrite core to be bonded together. a step of forming a composite core half by depositing a metallic magnetic material having a higher unsaturated magnetic flux density than the ferrite core on the upper surface of the composite core half; a step of polishing the gap surface smooth by using the metal magnetic material, the non-magnetic material portion, and the vertical side surface of the lower part of the ferrite core as the gap forming surface; A step of depositing a non-magnetic material with a thickness in the gap part by sputtering or the like, joining two composite core halves, 1A, and IE each having the gap part at the gap part, and adjusting the crystallization temperature of the metal magnetic material. A step of heat-treating at a lower temperature to form a head block body, a predetermined interval perpendicular to the working gap formed by the metal magnetic material of the head block body and at a depth reaching the non-magnetic material portion exposed on the upper surface portion. a step of providing a plurality of grooves in the metal magnetic material; and a step of filling the grooves with a non-magnetic material. This is a vapor deposition method.

Effect: According to the manufacturing method of the present invention, a non-magnetic material basically having a high melting point can be deposited at a relatively low temperature from the side surface of the track width to the entire gap depth, thereby preventing deterioration of the magnetic properties of the core material. It is possible to prevent this and obtain a product with high mechanical dimensional accuracy.

Embodiment FIG. 1 (Figures A to H) shows an example of the manufacturing process of a magnetic head according to the present invention.

The present invention is a head consisting of a composite core in which the entire operating gap depth is made of Sendust alloy or amorphous alloy having a high saturation magnetic flux density, that is, a metal material, and the other main magnetic path is made of ferrite. . The edge of the head track width, which has been narrowed for high-density recording, is reinforced to improve wear resistance due to contact with the magnetic tape, improve mechanical strength, and prevent chips and cracks at the track edge. This is a head manufacturing method that exhibits the effect of preventing this.

In other words, a structure is adopted in which a non-magnetic part, such as a glass part or ceramics, is provided on the tip end face of the ferrite, which is the main magnetic path of at least one of the pair of core halves, and a metallic magnetic material is sputtered onto the ferrite and the glass. A composite core provided by Furthermore, from one end surface of this composite core, the metal core, the glass part, and the ferrite are the same.
The surfaces are polished smooth to form the gap forming surfaces, S10□ and other non-magnetic substances are attached by sputtering, etc., and the pair of composite core halves are bonded to the gap surface, and the gap material or glass provided nearby is bonded. Weld them together to form a head block body.

Furthermore, a vertical cut groove is provided in the metal magnetic material portion on the head block body to cross the working gap with a size corresponding to the required track width. In this case, the depth of the cut groove is provided so as to reach the glass portion deeper than the metal magnetic material portion. After dividing into multiple track widths by the kerf in this way, SiC and α-Fe20 are deposited from the track ends into the kerf.
This is a method of manufacturing a magnetic head in which a suitable non-magnetic material such as 1 or glass is deposited by sputtering, vapor deposition, or electroplating.

An embodiment of the manufacturing method of the present invention will be described with reference to FIGS. 1A to 1H.

Figure A shows an L-shaped cutout in the vertical side part of the tip of the ferrite core (1), and the glass part (2) is fused to form the glass part (2). Polish the upper surface part (3) to the same surface. The glass portion (2) can also be formed using other ceramic materials by sputtering or the like.
Further, the upper surface portion (3) may be polished to an arbitrary curvature R. Next, Figure B shows the ferrite: +7 (11) and glass (2
), a metal magnetic material (4) such as sendust alloy or amorphous alloy having a higher unsaturated magnetic flux density than the ferrite core filtration is deposited by sputtering on the upper part (3) of the figure. Next, Figure 0 shows a trapezoidal groove (2) in which a part of the glass part (2) remains at the lower end of the metal core (4), and the upper and lower sides of the side surface where the glass part (2) is located form the oblique sides.
5) Form. After that, the glass part (2) and the groove part (5
) The end face of the ferrite core (1) provided with the ferrite core (1) is polished smooth so that it becomes the same plane, and a gap configuration consisting of the metal core end face (6), the glass end face (6)', and the ferrite end face (7) is formed. Get a face.

Figure D shows at least the metal core (
6) Place a gap material (with a thickness corresponding to the desired gap width) on top.
8) For example, S10. The OE diagram for manufacturing a pair of core halves IA and IB, which are deposited with high precision by sputtering or the like with a single layer or other non-magnetic material layered, is such that the core halves IA and IB are joined at the gap forming surface, The head block body 1 is manufactured by performing heat treatment at a temperature lower than the crystallization temperature of the metal magnetic material (4) with the gap material glass (8) or glass (2) or glass interposed from the groove (5).

Furthermore, FIG. 2 shows that a plurality of kerf portions αυ are sequentially processed in the tip metal magnetic body (4) on the head block body, leaving a width α corresponding to the required head track width. In this case, the kerf αυ
The depth α2 exceeds the working gap depth αj and is processed so as to reach the glass portion (2).

Next, diagram G shows the head track width from the kerf portion 00, (IC
A reinforcing portion (+4) is formed by coating a non-magnetic material such as SiO, α-Fe203, glass, or a metal material such as hard chrome on the side surface of the reinforcing portion (+4). The means for depositing it is performed by sputtering, plasma spraying, electroplating, or the like.

Next, in diagram H, the head block body 1 passes through its non-magnetic reinforcing parts (14), and at the position where non-magnetic reinforcing parts (14', ax' remain at both ends of the track width part, 0-
0. Cut and separate. The head is manufactured by separating the single head IA into a large number of parts.

In the above example, an amorphous alloy was deposited on the ferrite and glass to a thickness of approximately 30 microns by sputtering, as shown in Figure B. The amorphous material is Co--Nb Zr--Ta based, and its crystallization temperature is about 550C.

Also shown in the figure is a pair of core halves I as the gap material (8).
A and IB were each coated with 100 OA of SiO□, and 25 OA of low melting point glass with a softening temperature of about 400° C. was deposited thereon by sputtering.

Furthermore, as shown in Fig. E, the core halves IA and IB are joined at the gap surface, and a jig is used to lower the crystallization temperature of the amorphous alloy and soften the low melting point glass in the gap material glass part. Approximately 3 at a temperature approximately 100°C higher than the humidity
They were heat-treated in a nitrogen atmosphere for 0 minutes and welded together.

Furthermore, as shown in Figure F, the amorphous core part (4) of the metal magnetic material is cut using a precision cutting machine using a diamond grindstone.
Two types of track processing were carried out according to track widths of 15 microns and 30 microns, and grooves were sequentially processed to a depth approximately 10 microns deeper than the 30 micron thickness of the amorphous core portion.

In Figure 0, a 5iOO layer of about 50 microns was formed by sputtering SiO from the track end to the kerf.

Furthermore, as shown in Figure H, the core was cut to have a width of 100 microns including the reinforcing portion by S1c. That is, if the track width made of the amorphous alloy is 30 microns, there are SIA reinforcement portions on both sides of the track with a width of approximately 35 microns (the thickness of the SIC is 50 microns).

Reinforcement G# at the end of the head track, α-F as a reinforcing material
Including e203, Z n F e 203 and A no 2'0
Non-magnetic materials such as ceramic materials such as No. 3, glass materials such as 5i02, or metal materials such as hard chrome can be used.

On the other hand, various methods such as sputtering, vapor deposition, and electroplating can be applied as means for depositing these materials.

As a result of testing the head of the present invention manufactured as described above,
It produces various features and effects as follows.

Advantages of the Invention 1. Since the high melting point material can be applied to the head at a temperature sufficiently lower than the softening point or melting point of the material, 1. There is no effect such as cracks on both the head core and the reinforcing material due to thermal expansion.

2. Since it can be deposited at a relatively low temperature, there is no deterioration of the magnetic properties of the core due to core distortion due to heating temperature, or any adverse effect on mechanical dimensional accuracy.

3. Since the reinforcing material is applied in an on-dust order, it has good adhesion to the core and can be applied to localized areas such as chipping at the track edge, which prevents the track width from collapsing due to magnetic tape sliding. High dimensional accuracy can be obtained.

4. The head's electromagnetic characteristics were improved because the shape accuracy of the head track end was improved, the magnetic tape slid more accurately, and the magnetization state became more precise.

5. Since the reinforcing material is applied to the area that exceeds the gap depth, the section track of the entire gap depth is reinforced and strong.

[Brief explanation of the drawing]

Figure 1 is a process diagram of the magnetic head manufacturing method of the present invention, Figure A is the starting point where glass is fused to the upper tip of the ferrite core,
Figure B is a composite cross-sectional view of the core material with the upper surface of the core half polished and a metal magnetic material coated by sputtering, and Figure 0 is a cross-section of the core material with a groove connected to the lower part of the glass part of the composite core half. Figure, Did is a sectional view of a composite core half with a gap material coated on the end face of the composite core, Figure E is a perspective view of a head track section in which two composite core halves are joined at the end face to form a gap, and F The figure is a perspective view of a head block body that has undergone head track processing, including the gold M magnetic material on the upper part of the head block body. Figure H shows a perspective view of a single head manufactured by the manufacturing method of the present invention, and Figures 2A and B show a front view of a conventional head with reinforced track sides. . 1: Ferrite core 2 Glass part 4: Metal magnetic material 5: Groove part 6: Metal core end face part 6': Crow]
1i part 7: Ferrite end face part 8: Gap material H
: Head block body 1A, IB: Composite core half body lO
Nidrank width 1]: Cut groove part 12: Cut groove depth 13
: Gap depth 14: Reinforcement part a, a,: Cutting line Patent applicant Isao Abe, Patent attorney Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] (1) A non-magnetic material is exposed on the upper surface part and fused to a part of the tip of the ferrite core to form the non-magnetic material part, and an unsaturated magnetic flux from the ferrite core is applied to the non-magnetic material part and the upper surface part of the ferrite core. A step of forming a composite core half by depositing a metallic magnetic material with a high density to form a composite core half; A step of polishing the gap surface smooth by using the magnetic material part and the vertical side part of the lower part of the ferrite core as the gap forming surface;
A step of depositing a gap portion of a non-magnetic material having a thickness corresponding to a desired gap width on the gap-constituting surface portion of the composite core half body by sputtering or the like, a composite core half body comprising two of the gap portions, 1A, 1B. a step in which the metal magnetic material is joined at the gap portion and heat-treated at a temperature lower than the crystallization temperature of the metal magnetic material to form a head block body; A method for manufacturing a magnetic head comprising: providing a plurality of grooves in the metal magnetic material at predetermined intervals at a depth that reaches a non-magnetic material portion exposed to the magnetic material; and filling the grooves with a non-magnetic material. (2) The method for manufacturing a magnetic head according to claim 1, wherein the method for filling the groove with the nonmagnetic material is a sputtering method, a plasma spraying method, an electroplating method, or a vapor deposition method.