JPH041923A - Disk substrate - Google Patents

Abstract

PURPOSE:To uniformly apply a lubricant on the recording face without using a substrate holder by providing a radius side face for connecting one edge of the recording face with the other edge of recording face of a disk substrate. CONSTITUTION:The radius side face 9 of the disk substrate 3 for connecting one edge of the recording face 6 with the other edge of recording face 6, are provided. Or, it is also preferable to provide rugged side face 10 in a manner that fine grooves are formed in the thickness direction of the disk substrate 3. By this method, a lubricant can be uniformly applied on the recording sides 6 without using a substrate holder.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a disk substrate, and particularly relates to an improvement in the structure of the side surface to prevent so-called "drip" that causes uneven coating on the disk substrate. .

[Conventional technology]

Recently, there has been an increasing demand for improving mechanical durability such as wear resistance of thin film magnetic recording media formed by plating, vapor deposition, sputtering, etc. This durability is greatly influenced by the lubrication treatment technology, and even if the treatment is performed using a lubricant with excellent lubrication performance, the treatment method (conditions) is not appropriate. and do not exhibit sufficient performance. Therefore, it goes without saying that there is an urgent need to develop materials with excellent lubrication performance, but an even more important theme is to develop a universal processing method that can take full advantage of the material's properties.

FIG. 6 shows, for example, publications (Ths symposium
onmemory mad advanasd
rsaording &eahnology@s.

wa-3-a-1 (1986)) is a perspective view showing a schematic configuration of a dipping device (lubricant applicator). In the figure, (1) is, for example, a lubricant solution prepared by diluting a fluorine-based lubricant with a fluorine solvent, [2] is a lubricant solution tank containing lubricant solution (1), (3) is a disk substrate, and (4) is 45) is a substrate support that bundles and supports a plurality of disk substrates (3), and 45) is a substrate support 14) that is moved downward, and the disk substrate (3) is immersed in the lubricant solution (2), and then moved upward. This is an actuator that pulls the disk substrate (3) out of the lubricant solution (2).

FIG. 7 shows the so-called ""
FIG. 2 is a plan view showing locations where "drip" is likely to occur. In the figure, (6) is the recording surface of the disk substrate (3), and (7), indicated by diagonal lines, is the so-called "drip" area where the lubricant solution [21] is thick.

FIG. 88 is a plan view showing a conventional example disclosed in, for example, Japanese Utility Model Application Publication No. 151415/1983, which aims to uniformize the application of lubricant to a disk substrate. In the figure, (6) is the recording surface of the disk substrate, (7) is indicated by diagonal lines, and is the so-called "drip" area where the lubricant solution (2) is thick.
(8) is a substrate holder fitted on the same surface as the recording surface (6) of the disk substrate, and the "drip" portion (7) has moved to the periphery of the substrate holder (8). Therefore, when the substrate holter (81) is removed after applying the lubricant, a disk substrate with the lubricant evenly applied to the edges can be obtained.

[Problem to be solved by the invention]

When applying lubricant to a disk substrate using the conventional substrate holder as described above, it is necessary to manufacture a separate substrate holder, and it also takes time and effort to attach and remove this substrate holder. There was a problem in that the unit price of the board was also high.

The present invention was made to solve this problem, and an object of the present invention is to obtain a disk substrate that can uniformly apply lubricant to the recording surface without using a substrate holder.

[Means to solve the problem]

The disk substrate according to the invention of claim (1) has a rounded side surface connecting one recording surface end of the disk substrate and the other recording surface end of the disk substrate.

Further, the disk substrate according to the invention of claim (2) has a side surface having fine irregularities formed thereon.

[Effect]

The rounded side of the invention in claim (1) eliminates the presence of discontinuous points and corners with the recording surface.

Further, the fine unevenness formed on the side surface of the disk substrate according to the invention in claim 21 allows the lubricant solution to flow away by capillary action.

〔Example〕

FIG. 1 is a plan view showing a disk substrate in an embodiment of the present invention, and FIG. 2 is a side sectional view thereof.

In the figure, (3) is a disk substrate, (6) is a recording surface of the disk substrate (31), and (9) is a rounded side surface of the disk substrate.

Figure 3 is a plan view showing a disk substrate in another embodiment of the invention, and Figure 4 is a side view thereof.

In the figure, (to) is a finely uneven side surface with grooves formed in the thickness direction of the disk substrate.

FIG. 5 is a side view showing a disk substrate in still another embodiment of the invention. In the figure, 0 indicates a finely uneven side surface, such as a jagged or matte surface.

The operation of the present invention configured as described above will be explained based on experimental data.

First, the outside diameter is 30am, the inside diameter is 10om, and the thickness is 63mm (7mm).
) Using the dipping device shown in Figure @6 above, apply a fluorine-based lubricant (trade name: KRYτφx143An, manufactured by DuPont) to a Fluminiram disc substrate with trifluorotrichloroethane (fluorine-modified diluent) at a concentration of ICf. //1], 3Cf/IIJ, 5Cf
1/1], and the substrate is pulled up at a pulling speed of 0.2 (m/min).

As time passes, the lubricant solution flows downward due to gravity, and the remaining coating liquid in an equilibrium state eventually adheres to the disk substrate as a lubricant coating, determining the thickness of the lubricant. As the disk substrate is pulled up and dried, the remaining coating fluid is drawn to areas with good wettability. Table 1
Table 3 shows this fluorine-based lubricant (KRY rφ!1
The inventors developed a film thickness of 43AD), for example (Japan Society of Lubrication Society, Autumn Conference, Proceedings (1987) P, 485
These are the results measured by the high-sensitivity reflection method using FT-IR published in 488).

First, Table 1 shows the results of measuring the lubricant film thickness of the substrates shown in FIGS. 1 and 2. The film thickness at eight measurement points in the radial direction of the substrate at radial positions of 5 to 15 [am] is shown.

Table 1. The lubricant film thickness at each measurement position [A) C11th 1 Substrate with the side surface shape shown in FIG. 2) is also good.

Pump 2. The lubricant film thickness at each measurement position [λ] (substrate with the side shape shown in Figs. 3 and 4). pump 2
Table 3 shows the results of measuring the lubricant film thickness of a substrate having a side surface having a shape that is a combination of FIGS. 2 and 115.

From the results of all Examples, it was found that a uniform coating film was obtained without any problems.

Table 3 shows an example of a combination in which a rounded side surface is provided with minute irregularities, resulting in a more uniform lubricant coating. In addition, the irregularities in the details are partially added as shown in Table 3. Lubricant film thickness at each measurement position [λ] (Substrate with side surface shape that combines FIG. 974 and FIG. 5) [Effect of the invention] Since the disc substrate according to the invention of claim (2) has a rounded side surface that connects the recording surface end of the disc substrate with the other recording surface end of the disc substrate, the disc substrate according to the invention of claim (2) is free from fine irregularities. Since the disk substrate has the formed side surface, a disk substrate can be obtained that allows the lubricant to be uniformly applied to the recording surface without using a substrate holder.

[Brief explanation of the drawing]

! ! 1 is a plan view showing a disk substrate in one embodiment of the invention, FIG. 2 is a side sectional view of the disk substrate in FIG. 1, and FIG. 3 is a plan view showing a disk substrate in another embodiment of the invention. , FIG. 4 is a side view of the disk substrate of FIG. 3, FIG. 5 is a side view of a disk substrate showing still another embodiment of the present invention, and FIG. 6 is a schematic perspective view of the dipping device. ! Figure 7 is a plan view showing a conventional disk substrate.
FIG. 8 is a plan view showing a conventional disk substrate in which a substrate holder is fitted onto the conventional disk substrate of FIG. 7. FIG. In the figure, (3) is the disk substrate, (6) is the recording surface,
+91 is a rounded side, α0. ID is a side surface on which fine irregularities are formed. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A disk substrate characterized by having a rounded side surface connecting one recording surface end of the disk substrate and the other recording surface end of the disk substrate. (2) A disk substrate characterized by having a side surface with minute irregularities formed thereon.