JPH06126469A - Surface working method - Google Patents

Abstract

PURPOSE:To form fine ruggedness on the surface of a work while maintaining the flatness and smoothness of the surface. CONSTITUTION:The irradiated region of the work formed by irradiating the region with an ion beam of several 100KeV builds up in the case of the work made of metallic or ceramic materials and recesses in the case of the glass work. The mentioned above phenomenon is utilized in this method. Namely, the building up or recessing amt. is controlled by controlling the ion species for irradiation, energy and irradiation quantity and the space distribution is controlled by making combination use of the space scanning of the ion beam and mask patterns, by which the fine ruggedness is formed in arbitrary patterns on the surface of the work while the size over the entire part of the work is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface processing method capable of controlling the flow of an oil film and reducing friction by forming fine irregularities on the surface of a rolling element of a rolling bearing.

[0002]

Friction greatly depends not only on the material of the workpiece but also on the surface shape. In general, various polishing methods are often adopted as a method of changing the surface shape of the workpiece. Also known is a method of changing the surface shape of a workpiece by combining a mask pattern and an etching technique. Furthermore, as a special method, a method of modifying the surface by an ion implantation method using a high-energy ion beam to improve the frictional characteristics of the workpiece by forming a material having good frictional characteristics on the surface, or a low energy method There is also known a method of changing the surface shape of a workpiece by etching using an ion beam.

[0003]

However, in the conventional polishing method and etching method, an excessive amount of treatment is performed to impair the overall size of the surface of the workpiece, and to obtain the desired friction condition. In principle, the control was insufficient. Further, the surface modification by the ion implantation method that changes the material of the surface of the workpiece requires a large amount of ions to be implanted, resulting in a long treatment time and high cost.

[0004]

The present invention has been proposed in view of the above, and the surface of a work is selected by irradiating a work selected from metal, ceramics and glass with a high energy ion beam of several 100 KeV. The present invention relates to a surface processing method characterized by forming irregularities on a surface.

As described above, the material of the work object of the present invention may be any of metal, ceramics and glass. As a result of intensive studies on the interaction between an ion beam of several 100 KeV and a material, the present inventors have found that the surface of the material is raised by the ion beam irradiation while maintaining its overall size, and in the case of metal or ceramics, It was found that in the case of glass, it is depressed, and that the amount of protrusion and the amount of depression can be precisely controlled by the ion species to be irradiated, the ion energy and the irradiation amount.

The surface ridge or depression caused by the ion beam irradiation is closely related to the generation and accumulation of lattice defects in the material induced by the ion beam irradiation, and therefore the ion species to be irradiated, the energy and It is estimated that the amount of irradiation changes the amount of uplift and the amount of depression that accompanies changes in the generation and accumulation of lattice defects. Also, the temperature of the workpiece during irradiation is also related to this bulge and depression, but this also causes the lattice defects that are generated to be easily eliminated at high temperatures, so the amount of bulge and depression is relatively high as the temperature of the workpiece is high. It will be smaller.

According to the present invention, several hundred KeV is applied to the workpiece.
When the workpiece is made of metal or ceramics, the area irradiated by the ion beam rises when the workpiece is made of metal or ceramics, and when the workpiece is made of glass, the irradiated area is depressed, so that the entire surface of the workpiece is dimensioned. It is possible to form ultrafine unevenness having a height of several nm to several 100 nm while maintaining the above.

The dose of the ion beam of several 100 KeV to the workpiece is 1/10 to 1/1000 of the case of surface modification by the ion implantation method (10 ¹⁶ to 10 ¹⁷ ions / cm ² or more). It may be about (10 ¹³ to 10 ¹⁵ ions / cm ² ).

Further, by controlling the spatial operation of the ion beam to be irradiated and an appropriate mask pattern in combination, it is possible to control the size of the raised or depressed regions and the spatial distribution thereof. Then, by utilizing the high controllability of each of the spatial distribution and the height, it is possible to form arbitrary fine unevenness on the surface of the work piece that meets the desired friction condition.

[0010]

EXAMPLES Examples of the present invention will be shown below.

As a workpiece, a silicon wafer, a silicon nitride sintered body, an alumina sintered body, sapphire, quartz, stainless steel, quartz glass, and Pyrex glass, 400 to 4
Tables 1 to 11 show the relationship between the amount of surface irradiation and the amount of ion irradiation when an ion beam of 200 KeV was applied.
It was shown to.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

[Table 3]

[0015]

[Table 4]

[0016]

[Table 5]

[0017]

[Table 6]

[0018]

[Table 7]

[0019]

[Table 8]

[0020]

[Table 9]

[0021]

[Table 10]

[0022]

[Table 11]

Depending on the material of the workpiece to be irradiated with the ion beam, ridges or depressions start to occur at about 10 ¹³ to 10 ¹⁴ ions / cm ² , and the irradiation amount can be changed to several nm to several 100 nm. You can
In general, with metals and ceramics, the heavier the ions to be irradiated and the higher the energy of the ions, the smaller the amount of irradiation required to obtain the bumps of the same height. When irradiation is performed with energy, a larger amount of depression can be obtained with the same irradiation amount. Therefore, by controlling the ion species to be implanted, the energy, and the irradiation dose, it is possible to reproducibly form an arbitrary convex or concave portion having a height in the range of several nm to several 100 nm. Further, the amount of protrusion and the amount of depression depend on the temperature of the workpiece during ion irradiation, and a higher amount of protrusion or depression can be obtained at lower temperatures other than quartz. Therefore, 10
If you get a bump or depression that exceeds 0 nm,
It is desirable to cool the workpiece to about liquid nitrogen temperature.

When the irradiation dose is 10 ¹⁶ ions / cm ² or more, the effect of accumulated irradiated ions in the workpiece cannot be ignored. For example, silicon ions of 1 × 10
When irradiated with ¹⁶ ions / cm ^{2, the} surface bulge due to the accumulation of irradiated silicon ions is estimated to be about 2 nm, and the accumulation effect is even smaller for elements with a smaller ionic radius than silicon, and several times at most even for elements with a large ionic radius. It only happens. It can be said that most of the bumps generated by irradiation with an ion beam having an energy of several hundreds of KeV or higher are due to factors other than the accumulation of irradiated ions.

FIG. 1 shows an example of a three-dimensional profile of a silicon nitride surface when a silicon nitride sintered body is irradiated with 1000 keV silicon ions at 1 × 10 ions / cm ² , and FIG. 2 shows 2000 keV silicon ions at 1 × 10 ^{14 on} quartz glass. ions /
It is an example of a three-dimensional profile of quartz glass when irradiated with cm ² . In both figures, 1 indicates an unirradiated area and 2 indicates an ion irradiated area. In FIG. 1, the ion-irradiated area is raised by about 70 nm, and the unirradiated area having a width of about 200 μm forms the groove bottom. In Figure 2, the ion irradiation area is depressed by about 80 nm,
The unirradiated area having a width of about 120 μm is not affected by the ion irradiation. These are obtained by using the square mask pattern and the spatial operation of the beam together, but if a finer mask pattern is used, a more complicated and fine surface shape can be patterned on the workpiece. . Also,
The surface of the ion irradiation area is about the same as the unirradiated area,
It shows that the shape can be changed while maintaining the smoothness of the plane.

[0026]

As described above, according to the surface processing method of the present invention, by irradiating an ion beam of several hundreds of KeV, the surface of the workpiece can be kept in the desired size while maintaining the overall size of the surface. Unevenness can be formed.

Therefore, for example, by forming minute irregularities on the surface of the rolling element of the rolling bearing, the flow of the oil film can be controlled and the friction can be reduced. In addition to the reduction of friction, it is possible to prevent the magnetic head from being attracted by forming irregularities having a height of several tens nm on the surface of a flat and smooth glass substrate magnetic disk. At this time, in the case of a magnetic disk for hardware formatting, by using an appropriate mask pattern, it is possible to make a concavo-convex portion avoiding the signal recording portion, and to avoid signal modulation due to the concavity and convexity portion.

[Brief description of drawings]

FIG. 1 is a three-dimensional profile of the surface of a silicon nitride sintered body.

FIG. 2 is a three-dimensional profile of a quartz glass surface.

[Explanation of symbols]

 1 Unirradiated area 2 Ion irradiated area

Front page continuation (72) Inventor Setsuo Nakao 2-109 Yatsushiro Dormitory, Kita-ku, Nagoya-shi, Aichi No. 201 Dormitory, Yatsushiro (72) Inventor Kazuo Saito 183 Inasai-cho, Nakamura-ku, Nagoya-shi Aichi Prefecture No. 413 Inasai, Nomura (72) Inventor Yoshiko Miyagawa 6-15 No. Kago, Chikusa-ku, Nagoya, Aichi Prefecture (72) Inventor Sogo Miyakawa 6-15 No. Kago, Chikusa-ku, Nagoya City, Aichi Prefecture

Claims (1)

[Claims] 1. A surface processing method which comprises forming irregularities on the surface of a workpiece by irradiating the workpiece selected from metal, ceramics and glass with a high energy ion beam of several 100 KeV.