JPS6163925A - Manufacturing device of protection film for magnetic disk - Google Patents

Abstract

PURPOSE:To produce evenly a large quantity of protection films on both sides of a magnetic disk at a time, by forming alternately the flat plate and substrate holder electrodes in multiple stages in a plasma polymerization device which forms a plasma polymerized protection film to a magnetic disk. CONSTITUTION:Flat plate electrodes 5 and substrate holder electrodes 3 containing a cavity holding a magnetic disk substrate 4 respectively are set alternately and in parallel to each other in multiple stages within a vacuum container 1. Then the substrate 4 containing a ferromagnetic metallic thin film formed on a nonmagnetic substrate is set into the cavity of the electrode 3. Then the container 1 is exhausted through an exhaust port 7 to secure a vacuum state. Then the material gas for a plasma polymerized protection film is supplied through a supply pipe 2 into the space between both electrodes 5 and 6. The voltage of a high level is applied to the electrode 3 for generation of the glow discharge. In such a way, the plasma polymerized protection film is formed on both sides of the substrate 4.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a protective film manufacturing apparatus for magnetic disks.

(Prior Art and Problems) Conventionally, plasma polymerization apparatuses have been provided with an upper electrode 5 and a lower electrode 3' parallel to each other in a vacuum vessel 1, as shown in FIG. A substrate 4 is placed on top of the substrate 4, and the gas is evacuated from the bottom, and a raw material gas is supplied from above the substrate 4 through an introduction pipe 2, and the surface of the substrate is heated to a certain level. A plasma polymerized film is formed on the substrate 4 by applying an appropriate potential to the substrate 4.

However, when the apparatus shown in Fig. 4 is used as a protective film manufacturing apparatus for magnetic disks, it is possible to form a plasma polymerized film on both sides at the same time, but the protective film must be formed in two separate steps. Even when operated under certain conditions, there is a drawback that the physical properties, thickness, etc. of the protective film differ between the front and back sides of the magnetic disk.

Furthermore, if the electrodes are made larger in order to improve productivity, it becomes difficult to set the substrate in the center of the substrate holder, resulting in contamination or damage to the substrate.

(Objective of the Invention) An object of the present invention is to improve the drawbacks of conventional plasma polymerization apparatuses and to provide a manufacturing apparatus that uniformly forms a protective film on both sides of a magnetic disk simultaneously in large quantities.

(Means and effects for solving the problems) The present invention provides a plasma polymerization apparatus using opposed electrodes, in which substrate holding electrodes having holes capable of holding substrates are provided alternately in mutually parallel electrodes, Moreover, the drawbacks of the conventional method are solved by supplying the raw material gas between the electrodes.

That is, the present invention provides a plasma polymerization apparatus for forming a plasma polymerization protective film on a magnetic disk substrate in which a ferromagnetic metal thin film is provided on a nonmagnetic substrate. Substrate holding electrodes having at least one hole for holding the substrate are provided alternately in these electrodes, and an inlet for raw material gas is provided between each electrode. Protective film□ manufacturing equipment.

The present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory diagram of an apparatus according to an embodiment of the present invention. First, as shown in FIG.
Electrodes 3 having holes (hereinafter referred to as substrate holder electrodes) are provided alternately and in parallel. Although FIG. 1 shows an arrangement in which four substrate holder electrodes are provided, in the present invention, the number of substrate holder electrodes and the number of holes thereof are not limited to the above-mentioned numbers (although productivity can be increased by using multiple stages). Fig. 2a is a cross-sectional view of the substrate holder electrode 3, and Fig. 2 is a front view thereof. ℃
This is by blocking the holes in the substrate.

Although the shape of the electrode is circular in FIG. 2, it is not limited to this; other shapes such as square can also be used.

In addition, although the raw material gas is supplied into the vacuum container by the gas inlet pipe 2, the present invention is configured such that the raw material gas is supplied between the electrode and the substrate holder electrode. Therefore, when a daytime voltage is applied to the substrate holder electrode, a glow discharge due to the strong electric field occurs between the substrate and the grounded side of the vacuum chamber, and the plasma of the raw material gas is maintained evenly on the surface of the substrate holder electrode due to the weak electric field. be done.

Therefore, no pinholes are generated in the plasma polymerized film on the surface of the substrate due to minute sparks.

Further, in the present invention, it is preferable that there is no difference in level between the surface of the substrate of the substrate holder's electrode and the surface of its electrode, but if the difference in level is within ±5 mm, there will be no problem and plasma will be generated uniformly. , the physical properties and thickness of the protective film are the same. Such an effect cannot be obtained outside this range.

According to the present invention, since the electrodes and the substrate holder electrodes are provided alternately, a large number of substrates can be manufactured.

In the embodiment, a device in which electrodes and substrate holder electrodes are arranged in multiple stages in the vertical direction has been described, but the present invention can also be applied to a device as shown in FIG. 6 in which the electrodes and substrate holder electrodes are arranged in multiple stages in the horizontal direction. shows.

(Effects of the Invention) As explained in detail above, by using the magnetic disk protective film manufacturing apparatus of the present invention, a uniform plasma polymerized film with extremely few pinholes can be simultaneously formed on both sides of the magnetic disk, making mass production possible. It is possible.

[Brief explanation of drawings]

FIGS. 1, 2, and 6 are explanatory diagrams of an apparatus according to an embodiment of the present invention, and FIG. 4 is an explanatory diagram of a conventional apparatus. Number 1... Vacuum container, 2... Raw material gas introduction pipe, 3...
Substrate holder electrode, 3'... Electrode, 4... Substrate, 5
...Electric sliding door, 6...Canon 0.7...Exhaust port patent applicant Denki Kagaku Kogyo Co., Ltd. 3: Steam room;

Claims (1)

[Claims] In a plasma polymerization apparatus that forms a plasma polymerization protective film on a magnetic disk substrate in which a ferromagnetic metal thin film is provided on a nonmagnetic substrate, the electrodes are composed of an odd number of three or more parallel plate electrodes, and there are An apparatus for producing a protective film for a magnetic disk, characterized in that substrate holding electrodes having holes for holding at least one substrate are provided alternately, and an inlet for raw material gas is provided between each electrode.