JPH035701A - Optical window material - Google Patents

Abstract

PURPOSE:To obtain the optical window material which is inexpensive and can be formed to a large area and consists of diamond having good light transmittability by using the film-like diamond synthesized by a vapor phase method in the optical window material and forming the window part thereof into a two-layered structure consisting of the film-like diamond and grid- or net-shaped carbon fibers. CONSTITUTION:An Si substrate material 1 is prepd. and the film-like diamond 2 is deposited on one suface thereof by a microwave plasma CVD method. After photoresists 3 are applied over the entire surface of the front and rear surfaces thereof, the central part of the Si substrate is exposed by using a phtolithography technique. Only the Si in the exposed part is etched away and the photoresists peeled. After the substrate is cleaned, a mesh 4 of the carbon fibers is placed on the film-like diamond 2. Further, a window frame 5 made of a stainless steel is fixed by metal solder 6 onto the mesh, by which the carbon fiber mesh 4 and the film-like diamond 2 are fixed. The formation of the optical window material to the larger area is possible in this way and both the initial and production costs are reduce.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a window material used in optical systems for ultraviolet rays, visible rays, infrared rays, or X-rays.

[Summary of the invention]

The optical window material of the present invention is made of film-like diamond reinforced with lattice-like or net-like carbon fibers.

Extremely thin, X&? By reinforcing carbon fiber with good Li3 transitivity and high tensile strength, it is possible to increase the area of the window material, reduce cost, and increase pressure resistance without impairing the inherent light and X-ray transparency of film diamond. It is possible to improve the

[Conventional technology]

As is well known, diamond has excellent light transmittance in a wide range from the ultraviolet region with a wavelength of approximately 0.3 μm to the far infrared region with a wavelength of approximately 25 μm, and since it is composed of carbon atoms with a small atomic number, The light transmittance is also extremely good. Furthermore, it has high heat resistance of about 1200°C in vacuum and about 600°C in the atmosphere, so it is expected to be widely used as an optical window material.

With conventional technology, when trying to manufacture an optical window material made of diamond, methods such as using natural or artificially synthesized diamond crystals with a diameter of about 100 ml as raw materials and finishing them thinly through mechanical processing such as polishing and grinding are considered. .

[Problem to be solved by the invention]

However, in this case, large diamond crystals are rare and extremely expensive, making it extremely difficult to manufacture window materials with large areas (for example, direct pk 1 cm or more). Due to its hardness, it has the disadvantage that the cost required for machining is extremely high.

The object of the present invention is to solve these problems and provide a method for manufacturing an optical window material made of diamond with good light transmittance, which is inexpensive and can be made into a large area.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention uses a film-like diamond synthesized by a vapor phase method as a window material in an optical window material, and the window part is formed by combining the film-like diamond and lattice-like or net-like carbon fibers. It has a two-layer structure.

[Effect]

As shown in FIGS. 1 and 2, the optical window material according to the present invention has a film-like diamond reinforced with a carbon fiber lattice or mesh having high tensile strength, so that the film-like diamond does not warp. Prevents the occurrence of waviness, and
It can significantly improve pressure resistance and prevent breakage (Note: For example, commercially available carbon fibers have a tensile strength of 300 to 500 kg/Pengzen 2 at a diameter of around 7 μm).
.

Furthermore, since extremely thin carbon fibers with a diameter of several μm are used, the amount of light or X-rays transmitted through the window portion blocked by the carbon fiber lattice or net is extremely small and can be ignored. Furthermore, carbon fiber has good C
Since it consists of atoms, it is particularly advantageous for transmitting X-rays.

Further, there are methods for forming a diamond film, such as thermal CVD method, plasma CVD method, photo CVD method, ionization vapor deposition method, ion beam method, plasma jet method, etc., and no matter which method is used, there is no problem with the present invention. (Compared to the conventional method of machining diamond crystals into window materials, the area that can be formed into the film can be significantly increased, and the manufacturing cost can be significantly reduced.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. Third
Figures (A) to ([)) are explanatory diagrams of an example of the manufacturing process of the optical window material of the present invention, and these will be described below as Figures (^) to (D
) Abbreviated as figure.

First, as shown in figure (A), the diameter is 3 (in) and the thickness is 200 mm.
A Si substrate material 1 with a thickness of 2 μm was prepared, and a film-like diamond 2 with a thickness of 2 μm was deposited on one side of the Si substrate material 1 using the Microwave Blaze 7 CVD method (Japanese Patent Application Laid-Open No. 110494/1983) under the synthesis conditions shown in Table 1. .

Table 1 Next, after applying photoresist 3 to the entire front and back surfaces,
(B) As shown in the figure, the central part of 31 substrates was exposed using photolithography technology (exposed part diameter 20 m)
.

This was immersed in fA acid solution of HF + HNO3 (C)
As shown in the figure, only the exposed portion of St was removed by etching.

Next, after peeling off and cleaning the photoresist, as shown in Figure (D), a film with a diameter of 7 μm was placed on the diamond film 2.
m carbon fiber mesh 4 (mesh spacing 2.5 t
m) was posted.

Furthermore, as shown in FIG. 2, a stainless steel window frame 5 is fixed with metal solder 6, thereby fixing the carbon fiber mesh 4 and the film-like diamond 2. I got the window material.

We conducted a test to see if this window material could withstand atmospheric pressure (1 atm) by setting the window material on the outside wall of the vacuum chamber and reducing the pressure inside the vacuum chamber. No diamond breakage or leakage occurred, confirming that this window material had sufficient strength to withstand atmospheric pressure.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to increase the area of an optical window material made of diamond, and both raw material costs and manufacturing costs can be reduced.

Furthermore, since the carbon fibers reinforce the film-like diamond in the window, it is possible to prevent warping and waviness, significantly improve pressure resistance, and prevent breakage.

Furthermore, it has a wide range of light transmittance and also has good low energy X-ray transmittance.

[Brief explanation of drawings]

1 and 2 are a perspective view and a sectional view showing an example of an optical window material made of film-like diamond according to the present invention. Moreover, FIGS. 3(A) to 3(D) are explanatory diagrams of an example of the manufacturing process of the optical window material of the present invention. 1... Substrate material 2... Film-like diamond 3... Photoresist 4... Carbon fiber mesh 5... Window frame 6... Metal wax

Claims (1)

[Claims] An optical window material comprising a film-like diamond synthesized by a vapor phase method, wherein the window portion has a two-layer structure of a film-like diamond and a lattice-like or net-like carbon fiber.