JPH01204206A - Magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To prevent a thin film from being peeled at grooving time by forming first strain parting grooves in the channel forming part of a ferromagnetic metallic thin film, exposing the substrate and forming grooves in the exposing part of the substrate with mechanical grooving. CONSTITUTION:On a pair of substrates 7a and 7b, ferromagnetic metallic thin films 3a and 3b and non-magnetic thin films 8a and 8b for gap formation are successively formed in order. Next, the track width specifying channel forming part and coiling channel forming part, etc., of the non-magnetic thin films 8a and 8b and ferromagnetic metallic thin films 3a and 3b are selectively removed and first strain parting grooves 12a-12d are formed. Then, the upper surface of the substrates 7a and 7b are exposed. Next, grooving is executed to this exposed part by a dicing saw, etc., and track width specifying channels 13a and 13b, a coiling groove 13c and a glass stick inserting groove 13d are formed. Thus, a shock to the thin film by the grooving is suppressed and the thin film is prevented from being peeled. Then, an yield is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is a so-called composite tape in which a ferromagnetic metal thin film with a high saturation magnetic flux density is disposed near the gap of a magnetic core in order to handle a metal tape with a high coercive force. The present invention relates to a type magnetic head and a manufacturing method thereof.

(b) Conventional technology In recent years, the density of magnetic tapes used in magnetic recording and reproducing devices such as video tape recorders has been increasing, and ferromagnetic metal powders such as Fe, Co, and Ni are used as magnetic powders. Metal tape with high coercive force is now being used. On the other hand, as a magnetic head for recording on this metal tape, for example, as disclosed in Japanese Patent Application Laid-Open No. 58-175122 (IPC: G11B5/22), a part near the working gap is used as a magnetic core. Composite magnetic heads made of magnetic materials with higher saturation magnetization than ferrite (e.g. permalloy, sendust, amorphous magnetic materials) have been proposed, and these composite magnetic heads have improved reliability, magnetic properties, wear resistance, etc. It has eroded characteristics in terms of.

As shown in Fig. 15, this composite magnetic head generates a saturation magnetic flux near the gap (2) between a pair of magnetic core halves (1a) and (1b) made of ferromagnetic oxide such as Mn-Zn ferrite. There is one in which a ferromagnetic metal thin film (3a) (3b) such as Sendust with high density is arranged. Furthermore, (4)
is a glass for joining the magnetic core halves (1a) and (1b), and (5) is a winding groove.

However, in the case of the above-mentioned composite magnetic head,
The ferromagnetic metal '4 film is deposited on the top surface of the mirror-polished ferromagnetic oxide substrate by sputtering. It becomes non-magnetic due to diffusion, chemical reaction, inconsistency of crystal structure, etc., and becomes a pseudo gap, which adversely affects the performance of the magnetic head. That is, the 15th
As shown in the figure, in addition to the original gap (2), there are magnetic core halves (1a) (1b) and ferromagnetic metal thin films (3a) (3b).
Pseudo gaps (6a) (6b) are created at the bonding interface.

In addition, in order to suppress the occurrence of the above-mentioned pseudo gap, as shown in Fig. 16, the bonding interface between the magnetic core halves (1a) (1b) and the ferromagnetic metal thin films (3a) (3b) is changed to the original gap. (2) A composite magnetic head has also been proposed in which the magnetic head is non-parallel to the formation surface so that even if a pseudo gap occurs, the performance of the head will not be adversely affected. The manufacturing process of the magnetic head is more complicated and the cost is higher than that of the magnetic head shown in FIG. 15. Next, a method of manufacturing the magnetic head shown in FIG. 15 will be described.

First, as shown in FIGS. 17(a) and (g), a pair of substrates (7) made of a ferromagnetic oxide such as Mn-Zn ferrite
a) After performing mirror polishing on (7b), a 1-10 μm thick ferromagnetic metal thin film (3a) (3b) made of sendust or the like and a non-magnetic thin film (8a) for forming a gap such as 5i02 are formed by sputtering. 8b) and are formed in sequence.

Next, as shown in Figure 18 (G), one of the substrates (
7a) Track width regulation groove (9a) on the top surface, track width regulation groove (9b) and winding groove (5) on the top surface of the other board (7b)
and the glass rod insertion groove side are formed using a dicing saw or the like. In addition, by processing the track width regulating grooves (9a) (9bL winding grooves (5) and glass rod insertion grooves aα), non-magnetic thin films B3a) (8b) and ferromagnetic metal thin films (3a) (5b) are formed.
) and the substrates (7a) and (7b) are scraped off.

Next, after cleaning the pair of substrates (7a) (7b),
As shown in No. 19, the gap forming surfaces (Ila) (11b) of the substrates (7a) (7b) are abutted against each other with high accuracy, and a glass rod (2) is inserted into the glass rod insertion groove αα.

Thereafter, the glass rod O2 is melted by heating to 600 to 800°C to form the track width regulating groove (9a) (
9b) is filled with glass (4), and both substrates (7a) (
7b) are joined to form a block. Then, the block is cut along broken lines AA and BB shown in FIG. 19, and is ground and polished to complete the magnetic head shown in FIG. 15.

However, in the case of the above manufacturing method, the ferromagnetic metal thin film (
3a) (+b) is deposited by sputtering or the like, the temperature change caused by the sputtering causes the substrate (7
a) Internal strain occurs between (7b) and the thin films (3a) and (3b) due to the difference in coefficient of thermal expansion. The thin films (3a) and (3b) were peeled off, and the yield was poor at 10 to 20%.

Furthermore, as shown in Japanese Patent Application No. 194893/1989, the applicant has also developed a parallel type magnetic head shown in FIG.
It has been found that the pseudo gap can be suppressed by interposing a heat-resistant oxide thin film (not shown) such as 5i02 between the film and the film (b).

However, in this magnetic head, a ferromagnetic metal thin film (3
a) Because the adhesion force of (3b) was weakened, the peeling of the thin films (3a) and (3b) was even more severe compared to the magnetic head without the heat-resistant oxide thin film, and the yield was poor.

In addition to suppressing the pseudo gap, the heat-resistant oxide thin film also has the effect of suppressing strain between the magnetic core halves (1a) (1b) and the ferromagnetic metal thin films (3a) (3b).

(c) Problems to be Solved by the Invention The present invention has been made in view of the drawbacks of the above-mentioned conventional examples.
A track width regulating groove is formed on a substrate coated with a ferromagnetic metal thin film.
It is an object of the present invention to provide a method for manufacturing a magnetic head that prevents the thin film from peeling off when forming grooves such as winding grooves and glass rod insertion grooves.

Further, in the present invention, when a heat-resistant thin film is interposed between the substrate and the ferromagnetic metal thin film in order to suppress the pseudo gap,
It is an object of the present invention to provide a method for manufacturing a magnetic head that prevents the above-mentioned film peeling, which is particularly likely to occur.

Another object of the present invention is to provide a magnetic head in which peeling of the ferromagnetic metal thin film is prevented without deteriorating the magnetic properties.

B) Means for Solving the Problems The method for manufacturing a magnetic head of the present invention includes a first step of forming a ferromagnetic metal thin film on the upper surfaces of a pair of substrates made of ferromagnetic oxide, and A second step of exposing the substrate by forming a first strain dividing groove in a groove forming portion such as a track width regulating groove, a winding groove, a glass rod insertion groove, etc., and mechanically processing grooves in the exposed portion of the substrate. When forming a groove by applying ←÷3rd
It is characterized by including the steps of.

Another method of manufacturing a magnetic head of the present invention includes a first step of forming a ferromagnetic metal thin film on the upper surfaces of a pair of substrates made of ferromagnetic oxide, and a step of forming a ferromagnetic metal thin film on one of the substrates. A first strain dividing groove is formed in the track width regulating groove forming part of the thin film to expose the substrate, and the track width regulating groove forming part of the ferromagnetic metal thin film of the other substrate, the winding groove forming part, and the glass rod are formed. A first strain dividing groove is formed in the insertion groove forming part to expose the substrate, and a ferromagnetic metal thin film of the one substrate faces one or both of the winding groove forming part and the glass rod insertion groove. A second step of exposing the substrate by forming a second strain dividing groove in the portion of and a third step of forming a rod insertion groove.

Further, the present invention is characterized in that in the first step of the above-mentioned two magnetic head manufacturing methods, a heat-resistant thin film is formed on the upper surfaces of the pair of substrates, and then a ferromagnetic metal thin film is formed.

Further, in the magnetic head of the present invention, a strain dividing groove is formed in one or both of a portion of the ferromagnetic metal thin film of the magnetic core half facing the winding groove and a portion facing the glass rod insertion groove. The magnetic core half is exposed through a groove.

Further, in the magnetic head of the present invention, a heat-resistant thin film is interposed between the magnetic core half and the ferromagnetic metal thin film, and the boundary between the magnetic core half and the ferromagnetic metal thin film is in the working gap. It is characterized by being parallel to the

(E) Effect According to the manufacturing method of the present invention, the internal strain that causes film peeling of the ferromagnetic metal thin film is separated by the strain dividing groove, and moreover, the strain dividing grooves separate the internal strain that causes the peeling of the ferromagnetic metal thin film. Since the exposed portion is mechanically grooved, the impact caused by the groove processing is not transmitted to the ferromagnetic metal thin film very much.

Further, according to another manufacturing method of the present invention, the ferromagnetic metal thin film is further divided, and the internal strain is further divided.

Further, according to the manufacturing method of the present invention, even when the adhesion of the ferromagnetic metal thin film deteriorates due to the heat-resistant thin film for preventing pseudo gaps, film peeling can be sufficiently prevented.

Further, in the magnetic head having the structure of the present invention, strain dividing grooves are not formed in the magnetic path, the magnetic flux flows easily, and the magnetic characteristics do not deteriorate.

Further, according to the configuration of the present invention, in a magnetic head of a type in which the manufacturing process is simple due to the heat-resistant thin film, the interface between the ferromagnetic metal thin film and the magnetic core half is parallel to the working gap.
This prevents the ferromagnetic metal thin film from peeling off, and also prevents the flow of magnetic flux from becoming poor due to the strain dividing grooves.

(C) Example A first example of the present invention will be described in detail below with reference to the drawings.

3 to 5 are diagrams showing a method of manufacturing the composite magnetic head of the first embodiment, respectively.

First, as shown in FIG. 3(a) @, a pair of substrates (7a) made of a ferromagnetic oxide such as Mn-Zn ferrite is prepared.
(7b) After performing mirror polishing on the top, sputtering is performed to form a ferromagnetic metal thin film (3a) (3b) of 1 to 10 μm thick made of Sendust etc. and a non-magnetic thin film (8a) (8b) for gap formation such as 5iOz. and are successively formed in order. In addition, in order to suppress the effect of the pseudo gap, after performing mirror polishing on the substrates (7a) and (7b), the substrates (
7a) (7b) The upper surfaces of the substrates (7a) (7b) are etched with phosphoric acid, etc., and then the upper surfaces of the substrates (7a) (7b) are reverse sputtered with inert gas ions.
7b) On the upper surface 1csi02, a heat-resistant thin film (not shown) of Ti or the like may be formed by sputtering or the like, and the ferromagnetic metal thin films (3a) (3b) may be formed thereon.

Next, as shown in FIG. 4(a) @, one of the substrates (7a)
A non-magnetic thin film (8a) and a ferromagnetic metal thin film (6
Track width regulating groove forming part of a) and the other substrate (7b)
A nonmagnetic thin film (8a) and a ferromagnetic metal thin film (3
The first strain dividing groove (12a
) (12b) (12c) (12d) to expose the upper surfaces of the substrates (7a) (7t)). Note that if a heat-resistant thin film is formed, this thin film is also removed.

Next, as shown in FIG.
Track width regulating grooves (13a) (13b), winding grooves (13c), and glass rod insertion grooves (16d) are formed by grooving the exposed portions in the etching step 7b) using a dicing saw or the like. .

Thereafter, as in the conventional example, the pair of substrates (7a) (7b
) (7) forming a block by glass-bonding the gap forming surfaces (11a) and (11b), and cutting the block;
The magnetic head is completed by grinding and polishing.

According to the manufacturing method of the first embodiment described above, as shown in FIG. 14, the first strain dividing grooves (12a) (12b) (12c)
By forming (12d), the non-magnetic thin films (8a) (8b) and the ferromagnetic metal thin films (6a) (6b) are removed, and then mechanical groove processing is performed using a dicing saw or the like.
The impact applied to the ferromagnetic metal thin films (3a) (3b) during the groove processing is small, the peeling of the thin films (3a) (3b) is reduced, and when a heat-resistant thin film is not formed, the yield is 90 to 1.
00%, which is a significant improvement. However, if a heat-resistant thin film is formed, the yield will improve by 20-60%;
There's not enough rice. Incidentally, FIG. 14 is a diagram when the track width regulating groove (16a) is formed on the substrate (7a).

Next, a second embodiment of the present invention will be described in detail.

3 to 8 are diagrams showing a method of manufacturing a composite magnetic head according to a second embodiment.

First, as shown in FIGS. 3(a) and 3(b), a ferromagnetic metal thin film (3a) (3b) and a nonmagnetic thin film ( 8a) (8
b) form. In this case as well, a heat-resistant thin film may be formed as in the first embodiment.

Next, as shown in FIGS. 7(a) and 7(b), similarly to the first embodiment, track width regulating grooves are formed between the non-magnetic thin films (8a) (8b) and the ferromagnetic metal thin films (3a) (3b). The first strain dividing groove (12
a) (12b) (12c) (12d) are formed to expose the upper surfaces of the substrates (7a) (7b); Of the non-magnetic thin film (8a) and the ferromagnetic metal thin film (6a) deposited on the one substrate (7a), the first one of the other substrate (7b)
A second strain dividing groove (12e) is formed by removing the portion facing the strain dividing groove (12c) (12d) of the substrates (7a) (7b) by ion beam etching or the like.
) to expose the top surface.

Next, as shown in the 81st (ω■), the track width regulating groove (13a ) (13bL A winding groove (13c) and a glass rod insertion groove (13d) are formed.

Thereafter, the magnetic head of the second embodiment is completed in the same manner as the first embodiment.

FIG. 1 is a perspective view of the composite magnetic head of the second embodiment;
FIG. 2 is a sectional view taken along the line CC in FIG. 1, and the same parts as in FIG. 15 are given the same reference numerals. Of the gap forming surface of one magnetic core half (1a) of this composite magnetic head,
The part of the other magnetic core half (1b) facing the winding groove (13c) and the part facing the glass rod insertion #/j (13d) (this is the second strain dividing groove (12e) (12f) ) is formed, and the ferromagnetic metal thin film (3a) is not deposited.

According to the manufacturing method of the second embodiment described above, one substrate (7
The ferromagnetic metal thin film (3a) in a) also has strain dividing grooves (12e) (
12f) into a narrow range similarly to the other substrate (7b), and the strain caused by the difference in thermal expansion coefficient between the substrate (7a) and the thin film (3a) is also divided.
Even if mechanical groove processing is performed later, the influence of the impact generated at that time can be reduced, and the thin film (3a) will not be cracked or peeled off. According to the manufacturing method of this second embodiment, even if a heat-resistant thin film is formed to suppress the pseudo gap, peeling of the thin films (3a) and (3b) is reduced, and the yield is 95 to 100%. Significantly improved.

In addition, in the manufacturing method of the second embodiment, the strain dividing groove (1
2e) (12f) can be sufficiently suppressed on the other substrate (7b), but in the completed magnetic head, if, for example, a strain dividing groove α gradient is formed in the pack gap, it becomes difficult for the magnetic flux to flow, and the magnetic Characteristics deteriorate. That is, strain dividing grooves (12e) are provided in the part facing the winding groove (13c) where magnetic flux does not flow and in the part facing the glass rod insertion groove (13d).
The composite magnetic head of the second embodiment in which (12f) is formed has no film peeling and is excellent in head characteristics.

Next, a third embodiment of the present invention will be described in detail.

FIGS. 10 and 11 are diagrams showing a method of manufacturing a composite magnetic head according to a third embodiment.

In this third embodiment, similarly to the second embodiment, ferromagnetic metal thin films (3a) (3
After forming the non-magnetic thin films (8a) and (8b), the first and second strain dividing grooves (12a) (12b) (1) are formed by ion beam etching as shown in FIG.
2C) (12d) and (12f) are formed, respectively. This third
In the embodiment, the second strain dividing groove (
The strain dividing groove (12e) in the second embodiment is not formed.

Thereafter, as shown in FIGS. 11(a) and 11(c), track width regulating grooves (1
3a) (13b), a winding groove (13c), and a glass rod insertion groove (13d) are formed, and the substrates (7a) and (7b) are bonded, cut, and ground to form the magnetic head of the third embodiment. Complete.

- As shown in FIG. 9, the magnetic head of this third embodiment has a magnetic core half (1a) facing the glass rod insertion groove (13d).
) is formed by strain dividing grooves (12f) that allow ferromagnetic metal%! 1t (3a) is not deposited.

Although the manufacturing method of the third embodiment described above is somewhat inferior to that of the second embodiment, the first and second strain dividing grooves (12a)
(12b) (12c) (12d) (12f) The strain in the ferromagnetic metal thin film (3a) (3b) is sufficiently separated, and even when a heat-resistant thin film is formed, the ferromagnetic metal thin film (
The peeling of 3a) and (3b) is reduced, and the yield is significantly improved.

In the third embodiment, the second strain dividing groove was not provided in the part facing the winding groove forming part, but was provided in the part facing the glass rod insertion groove forming part. The insertion groove forming part 1 may not be provided in the part facing the winding groove forming part, but may be provided in the part facing the winding groove forming part.

Further, the magnetic head of the present invention has the above-mentioned first, second, and third magnetic heads.
In addition to the embodiment, as shown in FIG.
), the strain dividing groove (12g) formed in the part facing the winding groove (13c) is smaller than the winding groove (13c), and the 13th
As shown in the figure, a magnetic head may be used in which a strain dividing groove (12h) which also serves as a winding groove is formed in a portion facing the winding groove (13c).

The strain dividing groove (12h) is formed by a dicing saw after ion beam etching.

In addition, in the first, second, and third embodiments described above, the nonmagnetic thin film (
8a) and (8b) were formed, but a non-magnetic thin film may be formed after the subsequent groove processing.

(g) Effects of the Invention According to the present invention, the internal strain of a ferromagnetic metal thin film is divided and relaxed, and the impact on the thin film due to groove processing is suppressed, and the thin film is prevented from peeling due to groove processing during the manufacturing process. prevent,
It is possible to provide a method for manufacturing a magnetic head that prevents the yield from deteriorating.

Further, according to the present invention, it is possible to provide a method for manufacturing a magnetic head that sufficiently prevents peeling of the thin film even when a heat-resistant thin film is formed to suppress the pseudo gap.

Further, according to the present invention, magnetic properties are not deteriorated, and
A magnetic head in which peeling of a ferromagnetic metal thin film is prevented can be provided.

Further, according to the present invention, the magnetic core half and the ferromagnetic metal thin film are parallel to each other, which is easy to manufacture, and the magnetic properties are improved even if the pseudo gap is prevented by the heat-resistant thin film. It is possible to provide a magnetic head that does not deteriorate and in which the ferromagnetic metal thin film is prevented from peeling off.

[Brief explanation of the drawing]

1 to 14 relate to the present invention, in which FIG. 1 is a perspective view of a magnetic head of a second embodiment, FIG. 2 is a sectional view taken along line CC in FIG. 1, FIGS. FIGS. 5, 3, 7, and 8 are diagrams showing the manufacturing method of the magnetic head of the first embodiment, respectively.
The figure shows the manufacturing method of the magnetic head of the second embodiment.
The figure is a cross-sectional view of the magnetic head of the third embodiment, and FIGS. 10 and 11 are diagrams showing a method of manufacturing the magnetic head of the third embodiment.
12 and 16 are cross-sectional views of magnetic heads of other embodiments, and FIG. 14 is a diagram showing groove processing. 15 to 19 relate to a conventional example, FIGS. 15 and 16 are perspective views of a magnetic head, and FIGS. 17, 18, and 19 are views showing a method of manufacturing a magnetic head, respectively. be. (1a) (1b)...Magnetic core half, (2)...Gap, (3a) (3b)...Ferromagnetic metal thin film, (7a') (7b)...Substrate, (3a )
(8b) - Non-magnetic thin film, (12a) (12b) (1
2c) (12d)...first strain dividing groove, (12e) (
12f) (12g) (12h)...second strain dividing groove,
(13a) (1 lob)...Track width regulation groove, (13
c)...Winding groove, (13d)...Glass rod insertion groove.

Claims (8)

[Claims] (1) In a method for manufacturing a magnetic head in which a ferromagnetic metal thin film is formed on the operating gap abutting surfaces of magnetic core halves made of ferromagnetic oxide, a ferromagnetic metal thin film is formed on the upper surface of a pair of substrates made of ferromagnetic oxide. a first step of forming a first strain dividing groove in the groove forming portion of the ferromagnetic metal thin film to expose the substrate; and a second step of forming a mechanical groove in the exposed portion of the substrate. A method of manufacturing a magnetic head, comprising: a third step of forming grooves by applying (2) The groove forming section in the second step is at least one of a track width regulating groove forming section, a winding groove forming section, a glass rod insertion groove forming section, etc. A method of manufacturing a magnetic head. (3) In a method for manufacturing a magnetic head in which a ferromagnetic metal thin film is formed on the operating gap abutting surfaces of magnetic core halves made of ferromagnetic oxide, a ferromagnetic metal thin film is formed on the upper surface of a pair of substrates made of ferromagnetic oxide. forming a first strain dividing groove in the track width regulating groove forming portion of the ferromagnetic metal thin film of one of the substrates to expose the substrate; A first strain dividing groove is formed in the track width regulating groove forming part, the winding groove forming part, and the glass rod insertion groove forming part of the ferromagnetic metal thin film to expose the substrate; a second step of exposing the substrate by forming a second strain dividing groove in a portion of the ferromagnetic metal thin film of the one substrate facing one or both of the insertion grooves; A method of manufacturing a magnetic head, comprising a third step of performing mechanical groove processing to form a track width regulating groove, a winding groove, and a glass rod insertion groove. (4) Manufacturing the magnetic head according to claim 1, 2 or 3, wherein in the first step, a heat-resistant thin film is formed on the upper surfaces of the pair of substrates, and then a ferromagnetic metal thin film is formed. Method. (5) In the second step, the first,
Claim 1, characterized in that a second strain dividing groove is formed.
5. The method for manufacturing a magnetic head according to 2, 3 or 4. (6) A ferromagnetic metal thin film is formed on the gap forming surfaces of a pair of magnetic core halves made of ferromagnetic oxide, and the ferromagnetic metal thin films are brought into contact with each other via a nonmagnetic material to form an operating gap. In the magnetic head, a strain dividing groove is formed in one or both of a portion of the ferromagnetic metal thin film of the magnetic core half facing the winding groove and a portion facing the glass rod insertion groove; A magnetic head characterized by exposing half of the magnetic core. (7) The magnetic head according to claim 6, wherein a boundary between the magnetic core half and the ferromagnetic metal thin film is parallel to the working gap. (8) The magnetic head according to claim 6 or 7, characterized in that a heat-resistant thin film is interposed between the magnetic core half and the ferromagnetic metal thin film.