JPH04205804A - Magnetic head - Google Patents

Abstract

PURPOSE:To eliminate a reaction layer and an air bubble within a mold glass by welding one magnetic core half body where a gap member which is thicker than a gap member of the other magnetic core half body to the other magnetic core half body which has a gap member is provided on a magnetic gap formation surface, through the gap member. CONSTITUTION:A gap member consisting of SiO2 film 4 and a glass film for adhesion 5 exists at a boundary part between a soft magnetic film 1 of a high-saturation magnetic flux density and a mold glass 7 but the SiO2 film 4 not only has a function as a gap member but also prevents mutual diffusion between the mold glass 7 and a soft magnetic film 1 with a high-saturation magnetic flux density. Then, when the gap length becomes small, the SiO2 film 4 at a boundary part between the mold glass 7 and the soft magnetic film 1 with high-saturation magnetic flux density also becomes thin, thus enabling reaction to occur easily. Then, by forming the SiO2 film 4 at a side of a magnetic core half body where the soft magnetic film 1 with high-saturation magnetic flux is provided thickly, mutual diffusion of the soft magnetic film 1 with high saturation magnetic flux density and the mold glass 7 can be suppressed, thus eliminating a reaction layer and an air bubble which are generated within the mold glass 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to high-density magnetic recording media with high coercive force used in video tape recorders (VTRs), digital audio recorders (DATs), floppy disk drives (FDD), etc. Conventional technology regarding magnetic heads suitable for recording and reproducing information of Although it is generally known that the ferrite material is good, the saturation magnetic flux density of the ferrite material currently mainstream as a magnetic head material is about 5000 Gauss, and saturation occurs when used in metal tapes etc. that exhibit a high coercive force of 100000 Gauss or more. However, even though magnetic heads using materials such as Sendust alloy and Co-based amorphous films, which have a higher saturation magnetic flux density than ferrite materials, have been put into practical use, the sliding surface structure of conventional magnetic heads (mainly As shown in FIG. 5, the magnetic core halves 11 and 12 are made of an oxide magnetic material such as Mn-Zn ferrite, and the magnetic core halves 11 and 12 are made of a magnetic gap (hereinafter simply referred to as a gap) and the track. Even if the soft magnetic film 13 is formed on the side surface, the boundary surface between the magnetic core halves 11 and 12 made of ferrite and the soft magnetic film 13 is parallel to the gap surface, and the gap portion and the soft magnetic film 13 are connected to the track width. Regulation groove 1
Even if the boundary with the molded glass 15 filled in the head 4 is formed of a non-magnetic oxide material, such as a 5-ins layer 16 and an adhesive glass layer 17, this type of head is designed to simplify the manufacturing process. The problem that the invention attempts to solve even if a method is adopted in which the forming and molding processes for the track width regulating groove are performed simultaneously by flowing the glass from the winding groove and the glass installation groove (not shown in the figure) to the sliding surface side. However, with the above configuration, only a very thin Si02 layer (half the optical gap length) and an adhesive glass layer can be formed at the boundary between the soft magnetic film and the molded glass. In addition, when manufacturing magnetic heads, glass fusing is a common method for forming gaps.
Also, in order to simplify the process, it is best to pour the glass from the winding groove when forming the gap. When a magnetic head is constructed using this manufacturing method, only a very thin SiO2 layer and an adhesive glass layer are present at the boundary between the soft magnetic film and the molded glass. S, which has traditionally been used as a soft magnetic film and gap member,
The results of observing the reaction layer and bubbles generated in the molded glass when a magnetic head is constructed using iO2 and glass and the gap length is varied are shown.

Note in Table 1: Even though the glass in the table is molded glass, the structure of the magnetic head requires a soft magnetic film 13 on the gap forming surface of the magnetic core half lL12.
The ○ in the table indicates that a layer or metal different from the surrounding glass was deposited in the molded glass. (hereinafter simply referred to as the reaction layer), or bubbles. L × indicates the presence of at least one of the following phenomena. The smaller the gap length measured, the higher the probability that a reaction layer or bubbles will occur; It is possible to prevent the occurrence of force exchange.If the gap length is shorter than this, a reaction layer will be observed at the boundary between the mold glass and the soft magnetic film, and the generation of bubbles will also be observed. In addition, the reaction layer and bubbles between the Fe-based soft magnetic film and the molded glass were examined under the same conditions as the Co-based soft magnetic film. This tendency becomes stronger as the gap length becomes smaller.In a magnetic head structure in which the soft magnetic film and the gap member are evenly formed on the gap surfaces of the magnetic core halves on both sides, as described above, the gear tube. Mold glass person Although there is a problem that a reaction layer and bubbles are generated in the mold glass by just changing the conditions of the soft magnetic film etc., when these reaction layers are formed, uneven wear of the mold glass part occurs and electromagnetic conversion. This not only adversely affects the characteristics but also causes a decrease in the strength of the magnetic head.Furthermore, the presence of air bubbles in the molded glass has the problem of damaging the surface of the magnetic recording medium. In order to achieve the above object, a magnetic head 1 of the present invention is provided.
One magnetic core has a soft magnetic film with a high saturation magnetic flux density on its magnetic gap forming surface, and a gap member that is thicker than the gap member of the other magnetic core half that is opposed and abutted on the soft magnetic film. The half body and the other magnetic core half body having a gap member provided on the magnetic gap forming surface are welded together via the gap member 4. Effect The effect of the above structure is as follows: LSiO*III! at the boundary between the soft magnetic film and the molded glass. and the force of the gap member consisting of the adhesive glass film (especially S i Ot !
Table lIi In addition to its function as a gap member, it also has the role of preventing mutual diffusion between the molded glass and the soft magnetic film with high saturation magnetic flux density. However, as the gap length becomes smaller, it is natural that the molded glass and the soft magnetic film with high saturation magnetic flux density The 5ins film at the boundary with the soft magnetic film also becomes thinner, and reactions are more likely to occur. Therefore, by forming the 5ide film thickly on the side of the magnetic core half where the soft magnetic film with high saturation magnetic flux density is provided, it is possible to achieve high saturation. By suppressing the mutual diffusion of magnetic flux density between the soft magnetic film and the molded glass, it is possible to eliminate the reaction layer and bubbles generated in the molded glass.In addition, by configuring the gap member as described above, the high saturation magnetic flux between the molded glass and the molded glass can be suppressed. Since the reaction with the dense soft magnetic film can be suppressed, gap formation and glass molding into the track width regulating groove can be performed simultaneously. SUMO Example 1 First, an example regarding the structure of a magnetic head will be described.

Figure 1 shows an embodiment of the magnetic head of the present invention. Figure 1 (a) is a top view of the magnetic head of the present invention seen from the sliding surface side. C on magnetic film 1
oNbZ r (200 people) and its nitride CoNbZ
In this embodiment, a so-called superstructure nitride alloy film in which 100 layers of rN (200 layers) are alternately laminated is used, and the magnetic core halves 2.3 are made of an oxide magnetic material such as Mn-Zn ferrite; A soft magnetic film l with a high saturation magnetic flux density of about 4 μm is formed near the gap of the magnetic core half 2 and on the side of the track, and 5iO
Even if the a film 4 is formed by 1,500 people and the adhesive glass film 5 is formed by 300 people, the thickness of these films on the side of the truck is considered to be about 30% less. Although the SiO2 film 4 is formed near the gap between the magnetic core halves 3 and on the sides of the track, the molded glass 7 is not formed in the track width regulating groove 6.
Although FIG. 1(b) is a perspective view of the magnetic head of the present invention, the track width regulating groove 6 is formed from the sliding surface side to the back surface side. This part is filled with molded glass 7.

In this example, (above) the soft magnetic film 1 with high saturation magnetic flux density is coated with CoN.
bZ r (200 people) and its nitride C.

The strength is shown as an example using a so-called superstructured nitride alloy film in which 100 layers of NbZrN (200 layers) are alternately laminated.The present invention is not limited to this material, and has high saturation magnetic flux even after heat treatment at 500°C or higher. A similar effect can be obtained if the material exhibits soft magnetic properties at high density (high Bs), but such materials include materials whose average composition is expressed by the general formula TaMbNc h TM and its nitride (TMN ) (hereinafter referred to as TM/TMN) is a so-called superstructural composition-modulated nitride alloy film.

Regarding the composition, Co or Fe is used for &T in order to ensure the prescribed soft magnetic properties and Bs.
In the case of e, it is 70 to 95% and LM is Zr, Nb, Ta, Hf, Ti, MOl when Co is used for T.
When one or more elements in Wl and Fe are used in LT, Zr, Nb, Ta, Hf, Ti,
The amount of LM (b in the general formula) is an atomic ratio, and when CO is used for T, it is composed of one or more elements among Mo, Cr, W, Mn, Re, and Ru. ~20%
When Fe is used as T, the amount of nitrogen (C in the general formula) is 1.5 to 20%.Various films can be constructed using the combinations of the elements shown above. Among them, materials whose main components are C and o are ζ'c CoNbZr/CoNbZrN5 Co
TaZr/CoTaZrN, CoNbZrTa/CoN
bZrTaN, a material whose main component is FeN
b/FeNbN, FeZr/FeZrN, FeTi/F
eTiN, FeTi/FeTiN, FeNbZr/Fe
NbZrN, FeNbTa/FeNbTaN, FeZ
rTa/FeZ rTaN is desirable.There are various magnetic head structures other than those shown in Fig. 1. Examples of these are shown in Fig. 2 and Fig. 3. Magnetic Head GEL A soft magnetic film 1 with a high saturation magnetic flux density is formed only near the gap between one half of the magnetic core, and is not present on the side surface of the track.
The other structure is the same as that of the magnetic head shown in Fig. 1. Also, the magnetic head shown in Fig. 3 has a track width regulating groove 6 formed only in the front gap part, and that part is filled with molded glass 7. The other structure is the same as that of the magnetic head shown in Fig. 1. Fig. 4 is an enlarged view of the vicinity of the gap of the magnetic head of the present invention, showing the magnetic core half 3 without a soft magnetic film with high saturation magnetic flux density. 5102 film 4 with a thickness of 200 on the gap surface of
CoNbZr/CoNbZrN or FeN
A SiO2 film 4 is formed on the gap surface of a magnetic core half 2 provided with a bZr/FeNbZrN soft magnetic film 1 having a high saturation magnetic flux density, varying in the range of 800 to 2300.
Even if the bonding glass film 5 with a thickness of 300 mm is formed on the SiO2 film 4, and the track width regulating groove 6 is filled with mold glass 7, the soft magnetic film 1 with a high saturation magnetic flux density 5 formed on top of
The thickness of the IDE film was varied from 800 to 2,300.The conditions of the reaction layer and bubbles generated in the mold glass 7 were observed.The results are shown in Table 2.

Table 2 Note: The glass in the table is molded glass. From the same table, C is applied to the soft magnetic film 1 with a high saturation magnetic flux density.

Field A S 1 using NbZ r/CoNbZ rN
4 used in the study when the thickness of the OR film is 200 Å or more.
In all types of molded glass, no reaction layer or bubbles were observed in the molded glass.Also, if a suitable glass such as mold glass B is selected, the L reaction layer and bubbles will be reduced even if the SiO2 film is 1000. (-Therefore, the total film thickness of the gap member of both core halves at this time is 1500 mm, and an optical gap length of 0.15 μm can be obtained, and a ninth-order high saturation magnetic flux can be obtained.) FeNbZr/FeN on the dense soft magnetic film l
When a similar study was conducted using bZrN, no reaction layer or bubbles were observed in all four types of molded glass when the thickness of the 8102 film was 2000 Å or more. Select an appropriate material such as molded glass B, which has the same magnetic flux density as a soft magnetic film (the thickness of the isiO* film can be reduced to about 1200, and the optical gap length is 0.17μ).
5iO formed on the gap surface of one half of the magnetic core provided with a soft magnetic film with a high saturation magnetic flux density = thickness force of the gap member consisting of the film and adhesive glass By configuring the length to be larger than the thickness of the gap member made of SiO2 film formed on the gap surface of the other magnetic core half that faces and butts together, the magnetic head is free of reaction layers and bubbles in the molded glass. The magnetic head according to the present invention has the following effects: (1) No reaction layer and no bubbles in the molded glass.
Excellent effects such as no uneven wear, high chip strength, and no damage to the surface of the magnetic recording medium (2) A magnetic head with a higher saturation magnetic flux density than before can be obtained.
VTR1DAT can be used as a magnetic head for FDD with high coercive force tape (3) It is possible to realize a magnetic head with a narrow gap length of 0.20 μm or less, and it is also possible to obtain a magnetic head that is excellent in mass production and has a very simple process. Even if you can

[Brief explanation of the drawing]

FIG. 1(a) is a top view of an embodiment of the magnetic head of the present invention viewed from the head sliding surface. FIG. 1(b) is a perspective view of an embodiment of the magnetic head of the present invention. 4 shows an enlarged view of the vicinity of the gap of one embodiment of the magnetic head of the present invention. FIG. 5 shows a conventional magnetic head seen from the head sliding surface. The top view shows: Soft magnetic film with high saturation magnetic flux density 2, 3... Magnetic core half-arc 4... SiO2 film (gap member), 5.
・Glass membrane for adhesion (gap member). Name of agent: Patent attorney Akira Okaji and 2 others l - This book and Zero A Kosong 15 Fake Soft II So1 R Huang Z, s - a
lkkifu 7 hands 4-! ;rat 瞠 [(#Fude*Tt)Figure 2

Claims (1)

[Claims] (1) A soft magnetic film with high saturation magnetic flux density is provided on the magnetic gap forming surface, and the gap is thicker than the gap member of the other magnetic core half that faces and abuts on top of the soft magnetic film. A magnetic head characterized in that one magnetic core half provided with a member and the other magnetic core half provided with a gap member on a magnetic gap forming surface are welded together via the gap member. (2) The thickness of the gap member of the other magnetic core half that is not provided with a soft magnetic film with a high saturation magnetic flux density is 200 Å or more, and the gap member of one magnetic core half that is provided with a soft magnetic film with a high saturation magnetic flux density. 2. The magnetic head according to claim 1, wherein the thickness of the magnetic head is greater than 200 Å and less than 2300 Å. (3) The soft magnetic film with high saturation magnetic flux density has a structure in which a material represented by CoaMb and its nitride are alternately laminated, or the nitrogen composition is modulated in the film thickness direction. A magnetic head according to claim 1. Here, M is Zr, Nb, Ta, Hf, Ti, Mo, W
It consists of one or more elements among the following, where a and b represent the atomic ratio and satisfy the following formula. 0.80≦a≦0.95 0.05≦b≦0.20 a+b=1.0 (4) The soft magnetic film with high saturation magnetic flux density is made of a material represented by FeaMb and its nitride layered alternately. 2. The magnetic head according to claim 1, wherein the magnetic head has a structure in which the nitrogen composition is modulated in the film thickness direction. Here, M is Zr, Nb, Ta, Hf, Ti, Mo, C
It consists of one or more elements among r, W, Mn, Re, and Ru, and a and b represent atomic ratios and satisfy the following formula. 0.70≦a≦0.95 0.05≦b≦0.30 a+b=1.0