JPH01206163A - Light introducing airtight window for vacuum device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is applicable to the use of optical change iF, lI
Concerning airtight windows when carrying out.

(Prior art and its problems) Conventionally, various materials have been used for light-introducing airtight windows for vacuum equipment over a wide range from ultraviolet to infrared regions. That is, fused silica glass plates are usually used as light transmission windows in the ultraviolet region, quartz glass, pyrex glass, kovar glass, etc. are used in the visible region, and calcium fluoride, chlorinated zinc, etc. are used in the infrared region. It's here.

With the development of various lasers, optical CVD and photosynthesis have progressed,
There are now many opportunities to carry out these reactions in vacuum equipment. According to this, from short wavelength to long wavelength band,
With the increasing need to connect optically transparent window materials to vacuum equipment, there is a need to maintain a higher degree of vacuum within the vacuum equipment.

Conventionally, as a method for hermetically sealing these optical window materials to a vacuum device, as shown in FIG. 4(a), a metal ring 1 is used.
03 and the window material 101 are fixed to a vacuum flange 104 for attaching to a vacuum device by tightening rubber material °゛0゛°0゛° rings 102, 108 and screws 107,
It has generally been fixed to the main body of the vacuum device using bolts through holes 106 via a 0° ring or the like embedded in a groove 105 provided in the vacuum flange 104.

However, although this method is inexpensive, the °°O°° ring may change over time, and it is necessary to use grease for sealing, which is not preferable for achieving airtight sealing. In particular, when it is desired to bake out the moisture contained in the vacuum device by heating in advance, it has a fatal flaw in that it cannot be done.

Therefore, since it is not possible to obtain a sufficient degree of vacuum for chemical reactions conducted under the current high technology standards, it has not been used.

FIG. 4(b) shows another conventional example of a comparatively reliable method of constructing an airtight window. This method is manufactured using conventional electron tube manufacturing technology, in which an oxide layer of this alloy is created on the surface of the alloy to be sealed, and the electron tube is completely hermetically sealed via this layer.

According to this method, it is possible to heat the water to bake out the water, but the light transmission characteristics are limited to visible light and are completely ineffective against light in the ultraviolet region necessary for photoreactions. It had major flaws.

Furthermore, as a method of using a quartz glass plate that transmits light in the ultraviolet region well as a light transmitting window without impairing reliability, the method shown in FIG. 4(C) is known.

That is, quartz glass has a high melting point and a very small coefficient of thermal expansion. Therefore, a so-called intermediate glass whose characteristics are gradually changed is prepared in advance, and as shown in FIG. 4(C), an intermediate glass 102"° is formed.

The grated seal method is known, in which the expansion coefficient is gradually increased using 103°', 104'', 105'', etc., and finally 106'' Kovar glass is used, and this is hermetically sealed with Kovar alloy. However, this method requires a high degree of skill and has the drawbacks of relatively weak mechanical strength.The present invention provides a light-introducing airtight window for vacuum equipment that solves all of these drawbacks. be.

(Means for solving problems) FIG. 3 explains the basic principle of the invention.

A step part is formed at the end of the metal ring (or flange) 203, and the light introduction transparent window 201 is fitted into the step part to form a joint 202 between the metal flange 203 and the light introduction transmission window 201. A relatively malleable single or composite metal that does not melt at the required temperature, or a metal alloy layer is interposed, or this metal layer is provided on a thin metal ring, and the metal has a higher coefficient of thermal expansion than the window material. A vacuum flange 204 or a metal ring (or flange) 203 is formed in a vacuum or an inert gas atmosphere.
Alternatively, by heating the flange 203 to a high temperature and fitting a window material, a compression type light-introducing airtight window that can withstand high temperatures, has good vacuum tightness, and is highly reliable is constructed.

(Example) Next, details of an example according to the present invention will be described using the drawings.

FIG. 1 is an enlarged view of part A in FIG. 3, and shows an example in which a highly malleable single metal or alloy layer 302 is interposed between a metal ring (or flange) 303 and a transparent window 301 for introducing light. Representative examples of these metals are shown in Table 1. These metal rings may be interposed. Alternatively, it may be prepared in advance at a predetermined location on the metal ring (or flange) 303 by a method such as plating.

FIG. 2 shows another embodiment, in which a malleable metal layer 403 is provided on a thin metal ring 402 by a method such as plating, and this is connected to a transparent window 401 for introducing light and a metal ring (or flange) 404. This is an example placed in between.

Next, a specific example will be explained.

As an optical window for optical CVD, 185 nm emission spectrum of mercury and argon fluoride (ArF) of excimer laser are used.
) emission spectrum 193 nm, 1 of fluorine (F2)
A special ozone-free fused silica plate is known as an optical window that transmits light at a wavelength of 57 nm.

The case for sealing this quartz plate will be described as follows.

First, this quartz plate is rough-processed into a circular plate of the required diameter of 100 mm, and then its peripheral portion is optically polished and the dimensional accuracy is finished to about 5/100 mm. Next, the metal ring (or flange), in this case, is made of stainless steel, and its fitting part is made smaller in diameter by approximately 0°6m+n than the outside diameter of the window material.
Copper plating of approximately 50 microns is applied to the mating part, dried,
Annealing is performed in a hydrogen furnace at 1000° C. for about 15 minutes.

These window materials and rings are assembled using jigs and tools in a vacuum or an inert atmosphere, and the metal flange is approximately 50mm thick.
Heat it to 0°C and fit the window material to it.

When cooled to room temperature, the window material and metal flange are hermetically sealed via the copper in a compressed state.

The sealed body that I made like Kono is 110-1 Oat cc/
Airtightness of sec or more was obtained.

Of course, baking does not impair airtightness.

Since the thermal expansion of window materials varies widely, it goes without saying that it is necessary to design a compressed airtight seal.

Even when the transparent window for light introduction for vacuum equipment made in this way is exposed to high temperatures, the malleable metal in the joint does not melt and maintains sufficient airtightness, so it can be baked out at high temperatures. is also now possible.

Therefore, high-temperature bakeout, which was previously impossible, can be performed, and Gao Xin Ying can be hermetically sealed.

(Effects of the Invention) As explained above, according to the method according to the present invention, it is possible to mass-produce a light-introducing airtight window for a vacuum device with high airtightness and at low cost.

[Brief explanation of the drawing]

1 and 2 are sectional views of essential parts of the present invention, FIG. 3 is a diagram for explaining the basic principle of the present invention, and FIG. 4 is a diagram of a conventional embodiment. 301.401...Transmission window for light introduction, 302.403
...Single metal alloy layer, 303.404...Metal ring, 402...Metal thin plate ring. Patent applicant Japan Radio Co., Ltd.

Claims (3)

[Claims] (1) In a transmission window that introduces light into a furnace for a vacuum device, a stepped portion is provided at the end of a metal ring, and the stepped portion is plated or coated with a highly malleable single metal, composite metal layer, or metal alloy layer. 1. A light-introducing airtight window for a vacuum device, characterized in that a window material for pre-introduction is interposed by vapor deposition and fitted, and hermetically sealed by compression sealing. (2) A ring made of a thin plate of a highly malleable single metal or composite metal or alloy is interposed in the step portion of the metal ring according to claim 1, and a window material for pre-introduction is fitted, and compression sealing is performed. A light-introducing airtight window for vacuum equipment, characterized by being hermetically sealed. (3) A pre-introduction window material is fitted to the step portion of the metal ring according to claim 1 with a ring made of a thin metal plate to which a highly malleable single metal or composite metal or alloy is adhered interposed. , a light-introducing airtight window for vacuum equipment characterized by being hermetically sealed by compression sealing.