JPH03280219A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve the depositing property of each layer even using a cheap PET, etc., having low glass transition point as a substrate and to improve magnetic characteristics by heating the layers just before an upper layer film is formed by vapor deposition to form plural numbers of layers on the substrate, and then forming the next layer. CONSTITUTION:A lower layer film 2 is formed by vapor deposition of the material 16 on a substrate 1 in a state not heated, while the substrate 1 is travelled from a supply roll 12 along a cylindrical guiding body 14 to a winding roll 13. The substrate 1 with the lower layer film 2 deposited thereon is then traveled along the guiding body 14, where an upper layer film 3 is formed thereon by vapor deposition of the material 16 on the substrate 1 in a state not heated. In this process, just before the deposition position for forming the upper layer film 3, the lower film 2 on the substrate 1 is irradiated with an electron beam 22 from an electron gun 21 to be heated from the surface side, and then the upper layer film 3 is deposited. Thereby, deposition state in the layers and between the lower film 2 and the substrate 1 can be improved, and moreover, there is no problem for using a cheap PET having low glass transition point as the substrate 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a magnetic recording medium, particularly a substrate (base).
Manufacture of a magnetic recording medium with a multilayer film structure such as a so-called metal thin film vapor-deposited tape on which two or more vapor-deposited films are provided.
It is related to the method of sending.

[Summary of the invention]

The present invention relates to a method for manufacturing a magnetic recording medium, and in a method for manufacturing a magnetic recording medium having a multilayer structure in which a plurality of layers are laminated on a substrate, a lower layer film is heated immediately before the deposition of each upper layer film. Then, each upper layer film is deposited.

Further, in the present invention, in the method for manufacturing a magnetic recording medium having a multilayer structure as described above, each upper layer is heated by heating the lower layer immediately before the deposition of the upper layer while cooling the substrate. Perform film deposition.

According to each of the above-described manufacturing methods of the present invention, a magnetic recording medium with excellent characteristics can be stably obtained.

[Conventional technology]

Conventionally, the base (
1) A lower film (2) of a magnetic layer or a non-magnetic layer such as Co or Al1 as a base film is deposited on top, and an upper film (3) of a Go-Cr based magnetic layer is formed on this. A magnetic recording medium (4) having a multilayer structure has come into wide use.

As a method for manufacturing a thin film deposition tape with a multilayer structure of this kind, each layer is deposited on a magnetic recording medium in a deposition chamber (11), as shown in FIG. (4) is transferred from a supply roll (12) in the form of a film or tape to a take-up roll (13) using a rotating cylindrical guide called a can (4).
During the transfer, the required vapor deposition material is ejected from the vapor deposition source (15) and is vapor deposited onto the substrate (1) on the cylindrical guide (14). . The flight of this vapor deposition material (16) is caused by, for example, an electron gun (17).
) by electron beam bombardment. In the figure, (19) shows the vapor deposition material (16) of the vapor deposition source (15) on the substrate (
1) shows a mask or shield for depositing at the predetermined location;

In this case, for each vapor deposition of the lower layer film (2) and the upper layer film (3), the cylindrical guide body (14) is heated and the substrate (1) is heated to a temperature of 200" to 250" C by contact therewith. The lower layer II! (21 and It is known that it is desirable to improve the adhesion strength of the upper layer film (3) as well as the magnetic properties.However, in this way, the cylindrical guide body (
4) to have the function of heating to 200°C to 250°C not only requires a huge amount of cost to manufacture the device, but also uses inexpensive polyethylene terephthalate (PET) as the substrate (1), which has a low glass transition point Tg. ), etc., and for this reason, it is no longer possible to use materials with a higher Tg than PET, such as Tg ~
Polyimide (PI) etc. with a temperature of about 350℃ will be used, but the price of this PI is several tens to ten times cheaper than PET.
This is particularly undesirable as a popular magnetic recording medium because it is as large as 0 times. By the way, PET (7) Tg is 69°C, P
The Tg of I is about 350°C.

C Problems to be Solved by the Invention] The present invention provides a method for easily and easily producing a magnetic recording medium such as a thin-film vapor-deposited tape having a multilayer structure as described above by using PET, etc., which has a low glass transition point Tg and is inexpensive, as a substrate thereof. Magnetic recording that can reliably improve the adhesion of a multilayer film, especially the adhesion of each upper layer film to a film below it, and the adhesion of the bottom layer film to a substrate, thereby improving mechanical and magnetic properties. A method for manufacturing a medium is provided.

[Means for Solving the Problems] In the present invention, as shown in FIG. In the method for manufacturing a magnetic recording medium (4) having a multilayer film structure formed by stacking layers (as shown in FIG. Immediately before the lower layer film, that is, the film that becomes the adhesion surface of each upper layer film, in the figure, the lower layer film (
2] is heated from the surface side of this lower layer film (2) to vapor deposit each upper layer film (in the figure, the upper layer film (3)).

Alternatively, in the present invention, a magnetic recording medium (
In the manufacturing method of 4), while cooling the substrate (1), the films on each upper layer side of the substrate (1) are removed from the surface side of the lower layer film (2) immediately before the vapor deposition of the upper layer film (3) in the figure. Each upper layer film (3) is vapor-deposited by heating.

[Effect]

As described above, in the method of the present invention, the upper layer film (3) is vapor-deposited by heating the lower layer film (2) from the surface side immediately before the upper layer film (3) without heating the substrate (1). Therefore, even if PET, which has a low glass transition point Tg, is used as the substrate (1), a multilayer film can be deposited reliably without causing any problems such as deformation.

By heating the lower layer film (2) immediately before this vapor deposition, the adhesion state at the interface between the upper layer film (3) and the lower layer film (2) is improved, and at the same time, the lower layer film (2) and the substrate ( It was confirmed that the adhesion condition with 1) was also improved. In other words, it is possible to improve the adhesion between the multilayer films and between the underlying film and the substrate (1), thereby creating a magnetic recording medium (4) with a multilayer structure with excellent mechanical and therefore magnetic properties. I was able to get it.

〔Example〕

A case will be described in which a magnetic recording medium having a two-layer structure of a lower layer film (2) and an upper layer film (3) shown in the first article is obtained by the method of the present invention. FIG. 2 is a configuration diagram showing an example of a vapor deposition apparatus for carrying out the manufacturing method of the present invention, and parts in FIG. 2 that correspond to those in FIG. 3 are given the same reference numerals.

In this case as well, the substrate (1) constituting the magnetic recording medium (4) is transferred from the supply roll (12) in the form of a film or tape to the take-up roll (1) in the deposition chamber (11).
3), a rotating cylindrical guide body (14) is placed over a part of the circumferential surface of the so-called can, and during the transition, the required vapor deposition material (16) is flown from the vapor deposition source (15). to deposit it onto the substrate (1) on the cylindrical guide (14). The flight of this vapor deposition material (16) is, for example, an electron gun (1
This is done by electron beam bombardment from 7).

In the figure, (19) is the evaporation material (16) of the evaporation source (15).
2 shows a mask or shield for depositing the material at predetermined locations on the substrate (1). In such an apparatus, in the present invention, the substrate (1) is first transferred from the supply roll (12) to the take-up roll (13) by passing the cylindrical guide (14), that is, the can, from right to left in the figure. (1) is transferred, but at this time, the cylindrical guide body (14) is cooled without heating or by water cooling, air cooling, or the like. That is, the lower layer (2) is coated with, for example, Co, Co-Ni, without heating the substrate (1) or while cooling the substrate (1).
It is formed by vapor deposition of a vapor deposition material (16) such as TiGe or Bi.

Next, the substrate (1) on which the lower layer film (2) was deposited in this manner
) is again transferred from the supply roll (12) side to the take-up roll (13) side, surrounding the circumferential surface of the cylindrical guide body (14), as shown in FIG. Also at this time, the cylindrical guide body (14) is not heated or is cooled, and the base body (1) is not heated or cooled accordingly, and in this state, the Co.

Vapor deposition material (1
6) to form the upper layer 1! ! (3) is formed. At this time, in particular, heating is performed from the surface side of the lower layer film (2) on the substrate (1) by the heating means (20) just before the vapor deposition position for forming the upper layer film (3).

The heating means (20) is, for example, a far infrared ray from a halogen lamp, or an electron gun (with high heating effect) as shown in the figure.
21) by irradiation with an electron beam (22).

The heating by the electron beam (22) is performed by diffusing the electron beam rather than narrowing it down so that the spot diameter on the lower layer film (2) becomes five or more layers. The substrate (1) is scanned in the width direction at a moving speed of 3 m/min with a reciprocating scanning period of 10) one or more layers.

Example 1 A tape-shaped PET with a width of 127 m was used as the substrate (1), and the traveling speed of the substrate (1) was 3 m/min on the lower layer film (2) made of Ti with a thickness of 500 mm by the method described above. Coo in the manner described above. Nioh. The upper layer (3) was deposited by evaporation in oxygen to a thickness of 2000 mm at an incident angle of 45@ to form a magnetic film. In this example, the upper layer film (3
), each magnetic recording medium obtained by changing the spot diameter of the electron beam (22) from the electron gun (21) that irradiates the lower layer film (2) immediately before the vapor deposition part and the reciprocating scanning period thereof. Table 1 shows the measurement results of the coercive force Hc of the magnetic films (Samples 1 to 3), its variation, and the residual magnetic flux density Br.

According to this, it can be seen that when the spot diameter and scanning period of the irradiated electron beam are large, a magnetic recording medium with small variations, that is, stable and excellent characteristics can be obtained. and,
It has been confirmed that good characteristics can be obtained when the spot diameter is 5 mm or more and the scanning period is 10 Hz or more, as described above.

In the above example, the case where a multilayer magnetic recording medium (4) having a two-layer structure with one lower layer film (2) and one upper layer film (3) each as shown in FIG. 1 will be explained. However, it is not limited to such a two-layer structure, but can also be a multilayer film structure of three or more layers. In this case, when the upper layer film is sequentially vapor-deposited, the lower layer film is heated from the surface immediately before the vapor deposition. take a form.

[Effects of the Invention] As described above, in the method of the present invention, the upper layer film (3) is heated from the surface side of the lower layer film (2) immediately before the upper layer film (3) without heating the substrate (1). Since vapor deposition is performed, even if PET, for example, which has a low glass transition point Tg, is used as the substrate (1), a multilayer film can be reliably vapor-deposited without causing problems such as deformation.

By heating the lower layer film (2) immediately before this vapor deposition, the adhesion state at the interface between the upper layer film (3) and the lower layer film (2) is improved, and at the same time, the lower layer film (2) and the substrate ( It was confirmed that the adhesion condition with 1) was also improved. In other words, it is possible to improve the adhesion between the multilayer films and between the underlying film and the substrate (1), thereby creating a magnetic recording medium (4) with a multilayer structure with excellent mechanical and therefore magnetic properties. I was able to get it.

Further, according to the present invention described above, the substrate (1) is deformed by heating during vapor deposition or by heating accompanying vapor deposition because the substrate (1) is subjected to the deposition without being heated or while being actively cooled. This avoids the inconvenience of wrinkles and the like caused by tension caused by running. Furthermore, since the structure of the vapor deposition apparatus itself requires only a heating means for heating the lower layer film from the surface, it is possible to simplify the apparatus including the running system of the substrate (1), and to simplify the work. Therefore, it is possible to achieve mass production and therefore cost reduction.

[Brief explanation of the drawing]

FIG. 1 is an enlarged linear cross-sectional view of an example of a magnetic recording medium obtained by the manufacturing method of the present invention, FIG. 2 is a linear configuration diagram of an example of a vapor deposition apparatus for carrying out the manufacturing method of the present invention, and FIG. It is a line block diagram of the vapor deposition apparatus used. (1) is the base, (2) is the lower layer film, (3) is the upper layer film, (1
4) is the cylindrical guide (can), (15) is the evaporation source, (
20) is a heating means.

Claims (1)

[Claims] 1. In a method for manufacturing a magnetic recording medium having a multilayer film structure in which a plurality of layers are laminated on a substrate, immediately before depositing each upper layer film, the lower film is heated to separate each upper layer. A method for manufacturing a magnetic recording medium, comprising the step of depositing a film. 2. In a method for manufacturing a magnetic recording medium having a multilayer film structure in which a plurality of layers are laminated on a substrate, each upper layer film is heated by heating the lower layer film immediately before vapor deposition of each upper layer film while cooling the base member. 1. A method for manufacturing a magnetic recording medium, comprising performing vapor deposition.