JP2001059900A - Electron beam tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam tube which has sufficiently high transmissivity of electron beam and small distortion generating on window member and is obtainable of long life of use. SOLUTION: An electron beam tube 10 is provided with an electron beam generator 30 inside a vacuum vessel 20, the vacuum vessel is constituted of a lid member 22 provided so as to cover the front opening of a tube member 21 and having an electron beam path hole, and a window member 24 provided so as to seal the electron beam path hole of the lid member and the electron beam path region is formed. In the window member, the electron beam path region 24a is formed in the part with thickness below 6 μm and the window member is air-tightly welded and contacted with a metal film 25 of thickness below 10 μm on the peripheral surface of the electron beam path hole 23. The window member is desired to be formed in plate shape consisting at least one kind chosen from periodic table 14 family.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electron beam tube for emitting an electron beam.

[0002]

2. Description of the Related Art In recent years, drying of ink on printed matter, sterilization of food or medical products, and the like have been performed by using an electron beam. As an electron beam tube that generates such an electron beam, the one shown in FIG. 6 has been conventionally proposed.

FIG. 6 is an explanatory cross-sectional view of an example of the configuration of a conventional electron beam tube viewed from the front, and FIG.
FIG. 4 is an enlarged sectional view taken along line XX in FIG. The electron beam tube 40 of this example includes a vacuum container 50 and the vacuum container 5.
The sleeve 65 includes a metal sleeve 65 for preventing scattered emission of an electron beam, and an electron beam generator 60 disposed inside the sleeve 65.

The vacuum vessel 50 is made of a glass tube member 51 whose rear side (the lower side in FIG. 6) is sealed and an electron beam generator 60 provided to cover an opening on the front side of the tube member 51. Beam passage hole 53 through which the electron beam passes
Are formed, and a window member 54 provided to seal the electron beam passage hole 53 of the cover member 52 on the front surface. Here, the electron beam passage hole 53 is formed in the central region of the lid member 52 in an oblong shape that is elongated in the lateral direction (the horizontal direction in FIG. 6).

A plurality of (five in this example) electron beam passage areas 54a each having a small thickness are formed by forming a window member 54, for example, by using a silicon wafer as a material and thinning it by etching. The configuration is such that they are formed side by side in the direction (the left-right direction in FIG. 6). Reinforcing rib portions 54b are formed between the adjacent electron beam passage regions 54a.

[0007] As shown in FIG. 7, the window member 54 is hermetically welded to the lid member 52 by a metal brazing material 55. Specifically, on the surface of the peripheral portion of the electron beam passage hole 53 in the cover member 52, an aluminum alloy having a through hole corresponding to the electron beam passage hole 53 is formed.
A metal brazing material 55 made of, for example, a silicon alloy plate and having a thickness of, for example, 80 μm or more is arranged, and a window member 54 is placed on the metal brazing material 55. By melting the material 55, the window member 5
4 is welded onto the lid member 52.

However, it has been found that the electron beam tube 40 has the following problems. That is, in order to increase the transmittance of the electron beam, it is preferable to reduce the thickness of the electron beam passage area 54a of the window member 54.
m or less, the difference in thermal expansion between the window member 54 and the metal brazing material 55 causes the window member 54 to bend, thereby causing a large distortion in the window member 54. The heat generated when the electron beam passes through the electron beam passage area 54a of the member 54 is accumulated, so that the window member 54 is easily damaged, and eventually the service life of the electron beam tube 40 is extended. Can not be.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above circumstances, and its object is to provide:
An object of the present invention is to provide an electron beam tube that has a sufficiently high transmittance of an electron beam in a window member, but generates little distortion in the window member, and as a result, has a long service life.

[0009]

An electron beam tube according to the present invention is an electron beam tube in which an electron beam generator is provided inside a vacuum vessel, wherein the vacuum vessel has an opening in front of a tube member. A cover member provided to cover, having an electron beam passage hole, and a window member provided with an electron beam passage area provided to seal the electron beam passage hole of the cover member, The window member has an electron beam passage area formed by a portion having a thickness of 6 μm or less, and is hermetically welded to a surface of a peripheral portion of the electron beam passage hole of the lid member by a metal film having a thickness of 10 μm or less. It is characterized by having been done.

In the electron beam tube according to the present invention, it is preferable that the window member is formed of a plate-like body made of at least one member selected from Group 14 of the periodic table.

[0011]

According to the above construction, the window member has a thickness of 10 .mu.m on the surface of the peripheral portion of the electron beam passage hole of the lid member.
m or less, the external force acting on the window member due to the melting and solidification of the metal film is small, and the distortion generated in the window member is small.
It is possible to effectively prevent the window member from being damaged by heat generated by the emission operation of the electron beam. As a result, an electron beam tube having a long service life can be obtained. Further, since the distortion generated in the window member is small, the thickness of the portion of the window member that forms the electron beam passage area can be set to 6 μm or less,
Thereby, a high electron beam transmittance can be obtained in the window member.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing an example of the configuration of the electron beam tube of the present invention, and FIG.
FIG. 3 is an enlarged cross-sectional view taken along the line AA in FIG.
FIG. 2 is a bottom view of the portion of the electron beam passage hole 23 in FIG. 1 as viewed from the rear (from below in FIG. 1). Electron beam tube 10 of this example
Is a vacuum vessel 20, a metal cylindrical sleeve 35 provided in the vacuum vessel 20 and having open front and rear ends, and an electron beam generator 30 disposed inside the sleeve 35. It is composed of Sleeve 3
Numeral 5 is for preventing the random emission of the electron beam.

The vacuum vessel 20 has a tube member 21 made of, for example, a cylindrical Pyrex glass having a sealed rear side.
A cover member 22 provided with an opening on the front side of the tube member 21 and formed with an electron beam passage hole 23 through which an electron beam from the electron beam generator 30 passes; A window member 24 is provided to seal the beam passage hole 23 on the front surface. Here, the electron beam passage hole 23 is formed in a central region of the lid member 22 in an oblong shape that is elongated in the lateral direction (the horizontal direction in FIG. 1). Reference numerals 31 to 33 denote lead rods electrically connected to the electron beam generator 30, which are fixed in a state where they penetrate the rear end wall of the tube member 21 in an airtight manner.

The window member 24 is formed by, for example, using a silicon wafer having a total thickness of 500 μm as a material and thinning the silicon wafer by an etching process.
A plurality (five in this example) of m rectangular electron beam passage areas 24a are formed side by side (horizontally in FIG. 1). The reinforcing rib portion 24b is formed between the adjacent electron beam passage areas 24a.

The window member 24 is hermetically welded to the lid member 22 by a metal film 25 acting as a brazing material, as shown in FIG. In particular,
A metal film 25 having a thickness of, for example, 5 μm is formed on the surface of the peripheral portion of the electron beam passage hole 23 in the cover member 22 by, for example, depositing aluminum, and the window member 24 is mounted on the metal film 25. Place and press
By heating in a vacuum to melt and solidify the metal film 25, the window member 24 is welded and joined to the lid member 22.

Examples of the material of the metal film 25 include metals other than aluminum, such as aluminum-silicon alloy, gold, gold-silicon alloy, titanium, titanium alloy or zirconium, which have a high affinity for silicon. A metal or alloy that forms a eutectic with silicon is preferable.

According to the electron beam tube 10 described above,
Since the window member 24 is hermetically welded to the surface of the peripheral portion of the electron beam passage hole 23 of the lid member 22 by a metal film 25 having a thickness of 10 μm or less, the metal film 25
The external force acting on the window member 24 due to the melting and solidification of the material becomes small, and the distortion generated in the window member 24 is small. Therefore, it is possible to effectively prevent the window member 24 from being damaged by the heat generated by the electron beam emission operation. As a result, the service life is prolonged. Moreover, according to the above-mentioned electron beam tube 10,
Since the distortion generated in the window member 24 is small, the window member 24
The thickness of the portion forming the electron beam passage area can be set to 6 μm or less, whereby a high electron beam transmittance can be obtained in the window member.

The reason why such an excellent action and effect is exhibited is that the shrinkage width in the longitudinal direction of the metal film 25 becomes small because the thickness of the metal film 25 having the function as a brazing material is small. And the metal film 2 which is melted and solidified
It is conceivable that the change in the thickness of No. 5 is small.

In the present invention, the thickness of the metal film 25 is 10
If it is not more than μm, a long service life can be obtained as is clear from the examples described later. The lower limit of the thickness of the metal film 25 may be a thickness that achieves a sufficient hermetic bonding, but is preferably, for example, 3 μm or more. If the thickness exceeds 10 μm, the intended operation and effect cannot be obtained reliably.

In the electron beam tube according to the present invention,
If the thickness of the portion forming the electron beam passage area in the window member is 6 μm or less, sufficient electron beam transmittance can be obtained, but this thickness is preferably smaller, for example, 2 to 5 μm. Is preferred. If the thickness of the portion forming the electron beam passage area is too small, the mechanical strength of the window member in the electron beam passage area becomes weak, and the window member is easily broken.

In the present invention, the formation of the metal film can be performed at any position of the cover member or the window member. Specifically, the location where the metal film of the lid member is formed is the peripheral portion of the electron beam passage hole as described above. Further, the portion of the window member where the metal film is formed is a portion facing the peripheral portion of the electron beam passage hole of the lid member when welding is performed. As a method for forming the metal film, a method such as thermal spraying, sputtering, or plating may be used in addition to the above-described vapor deposition.

In the window member of the electron beam tube, it is preferable that a layer made of corrosion-resistant silicon nitride is formed as an outer layer, that is, a layer exposed to the atmosphere. Further, the portion of the window member that becomes the electron beam passage area may be doped with, for example, boron, phosphorus, or arsenic. In this case, there is an advantage that the electron beam passage area is easily formed. There is.

In the electron beam tube of the present invention, as the material of the window member, in addition to silicon, at least one member selected from Group 14 of the periodic table can be used. Specifically, carbon, germanium, etc. Can be used.

[0024]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. <Example 1> Electron beam passage holes (2) in lid member (22)
A metal film (25) having a function as a brazing material is formed by evaporating aluminum having a thickness of 5 μm on the surface of the peripheral portion of 3), and a window member (25) is formed on the metal film (25). The vacuum container (24) is placed and pressed, heated in a vacuum to melt the metal film (25), and the window member (24) is hermetically welded and joined to the lid member (22). 2
An electron beam tube (10) of the present invention comprising (0) was manufactured.

Example 2, Comparative Examples 1-2 The electron beam tube of the present invention was produced in the same manner as in Example 1 except that the thickness of the metal film was changed to the thickness shown in Table 1 below. Then, each of the electron beam tubes for comparison was manufactured.

COMPARATIVE EXAMPLE 3 A metal braze made of an aluminum-silicon alloy plate having a thickness of 80 μm and having a through hole corresponding to the electron beam passage hole on the surface of the peripheral portion of the electron beam passage hole of the cover member. A window member is placed on the metal brazing material, and in a state where the window member is pressed, the window member is heated in a vacuum to melt the metal brazing material, and the window member is welded and bonded to the lid member. A comparative electron beam tube comprising a container was manufactured.

When the window member of each electron beam tube obtained in Example 1 and Example 2 was photographed under illumination light, the results shown in FIGS. 4A and 4B were obtained. In these figures, a photographic image in which a stripe pattern of light is generated due to distortion is subjected to binarization processing and subjected to black and white development. Similarly, FIG.
(A) to (C) are obtained from photographic images obtained by photographing the window members of the electron beam tubes obtained in Comparative Examples 1 to 3.

FIGS. 4 and 5 clearly show that the window member of the electron beam tube obtained in Example 1 and Example 2 has a large stripe pattern, and thus the distortion generated in the window member is small. It is. On the other hand, the distortion generated in the window member of the electron beam tube obtained in Comparative Example 1 to Comparative Example 3 is large, and the distortion generated in the window member of the electron beam tube obtained in Comparative Example 3 is particularly large. Obviously, it is very large.

The service life of each of the electron beam tubes obtained in Examples 1 and 2 and Comparative Examples 1 to 3 is shown in Table 1 below.

[0030]

[Table 1]

From the above Table 1, it can be seen that Examples 1 and 2 were used.
The electron beam tube obtained by the above method has a metal film thickness of 10
When the thickness is less than μm, a very long service life can be obtained, but it is clear that the service life of the electron beam tubes obtained in Comparative Examples 1 to 3 is short.

[0032]

As described above, according to the present invention,
Since the window member is hermetically welded to the surface of the peripheral portion of the electron beam passage hole of the lid member by a metal film having a thickness of 10 μm or less, the window member acts on the window member as the metal film melts and solidifies. The external force applied to the window member is small, and the distortion generated in the window member is small. Therefore, it is possible to effectively prevent the window member from being damaged by the heat generated by the emission operation of the electron beam. can get. In addition, since the distortion generated in the window member is small, the thickness of the portion forming the electron beam passage area of the window member can be set to 6 μm or less, whereby a high electron beam transmittance can be obtained in the window member. Can be

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an example of the configuration of an electron beam tube according to the present invention.

FIG. 2 is an enlarged sectional view taken along line AA in FIG.

FIG. 3 is a bottom view of the portion of the electron beam passage hole 23 in FIG. 1 as viewed from the rear (from below in FIG. 1).

FIGS. 4A and 4B are photographs of a window member of an electron beam tube obtained in Example 1 and Example 2, respectively.

FIGS. 5A to 5C are photographs of window members of an electron beam tube obtained in Comparative Examples 1 to 3, respectively.

FIG. 6 is an explanatory sectional view showing an example of a configuration of a conventional electron beam tube.

FIG. 7 is an enlarged sectional view taken along line XX in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electron beam tube 20 Vacuum container 21 Tube member 22 Cover member 23 Electron beam passage hole 24 Window member 24a Electron beam passage area 24b Reinforcement rib part 25 Metal film 30 Electron beam generator 31, 32, 33 Lead rod 35 Sleeve 40 Electron Beam tube 50 Vacuum container 51 Tube member 52 Cover member 53 Electron beam passage hole 54 Window member 54a Electron beam passage area 54b Reinforcement rib part 55 Metal brazing material 60 Electron beam generator 65 Sleeve

Claims (2)

[Claims] 1. An electron beam tube in which an electron beam generator is provided inside a vacuum vessel, wherein the vacuum vessel has a cover member having an electron beam passage hole provided so as to cover an opening in front of the tube member. And a window member provided with an electron beam passage area formed so as to seal the electron beam passage hole of the lid member, wherein the electron beam passage area has a thickness of 6 μm or less. An electron beam tube which is hermetically welded and joined to a surface of a peripheral portion of an electron beam passage hole of a lid member by a metal film having a thickness of 10 μm or less. 2. The electron beam tube according to claim 1, wherein the window member is formed of a plate-like body made of at least one member selected from Group 14 of the periodic table.