JPS5818740B2 - Vacuum container for radiation image intensifier tube and method for manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation image intensifier tube such as an X-ray fluorescence intensifier tube that uses X-rays, gamma rays, and other similar radiation to intensify and reproduce an image of an object to be examined, particularly in a vacuum container. Regarding the structure of, and the method of manufacturing the same.

For example, in an X-ray fluorescence intensifier tube, the X-ray input window that forms part of the vacuum vessel is made of Al (aluminum) or A1 alloy, which has relatively high mechanical strength, excellent X-ray transparency, and low X-ray scattering. (hereinafter simply referred to as AA material) has been attempted.

On the other hand, the output part of the vacuum vessel must be constructed of glass or ceramic insulators in order to prevent discharge of the accelerating electrodes and to guide image-enhancing signals such as visible light images or electrical signals converted inside the tube to the outside.

As is well known, the airtight bond between glass and aluminum material is essential.
Direct airtight bonding between ceramic and Al material is not easy, and the technology for stable airtight bonding between these materials has not yet been fully developed, especially in this type of radiation image intensifier tube with a relatively large diameter.

Therefore, iron (Fe), known as Kovar, or iron (Fe), which can form a stable airtight bond with glass and ceramics,
Fe such as nickel (N1), cobalt (Co) alloys
Practically, it is desirable to have a configuration in which the aluminum material is hermetically bonded to the aluminum material via an intermediate cylinder made of an alloy.

In this configuration, Al material and Fe or Fe alloy (hereinafter referred to as
An important issue is what structure and method should be used to achieve an airtight seal with the Fe material (simply referred to as Fe material).

As a technique for airtightly joining the Al material and Fe material in this vacuum container, a thin layer of silver (Ag) or Ni and Ag is plated or vapor-deposited between the two, and these are heated and pressurized for diffusion bonding. The technology to do this is USP 4,153,85
4 specifications.

Furthermore, a technique for performing eutectic bonding by plating tin (Sn) and copper (Cu) or gold (Au) between the two is also disclosed in JP-A-52-138861.

Furthermore, either a Ni plating layer is formed on the surface of both, or
Alternatively, a technique of arc welding by sandwiching a Ni thin plate between the two is also disclosed in Japanese Utility Model Publication No. 49-25810.

The above-mentioned known techniques using heat-pressing or eutectic bonding are effective as solutions, but the high cost of the materials makes them inconvenient for industrial mass production.

In addition, further improvement is required in terms of mechanical bonding strength.

Furthermore, if the degree of mutual diffusion of dissimilar metals in the above-mentioned welding method or diffusion bonding becomes excessive, brittle intermetallic compounds are likely to be formed, so that this method has not yet been sufficiently adopted in practice.

The present invention has been made in view of the above-mentioned circumstances, and a plating layer or vapor deposition layer of one or more of Ni, Cu, and AA, which is suitable for relatively mass production, is interposed between the AA material and the Fe material and heated. The present invention provides a vacuum container for a radiation image intensifier tube which is crimped and has an extremely stable and strong airtight joint, and a method for manufacturing the same which is more stable and easier to manufacture.

Hereinafter, an example of an X-ray fluorescence intensifier tube will be described with reference to the drawings.

Identical parts are designated by the same reference numerals.

The embodiment shown in FIGS. 1 to 4 has the following configuration.

As shown in FIG. 1, this X-ray fluorescence intensifier tube 21 is used by being housed inside a camera lens mount 23 lined with a magnetic shield cylinder 22 and a lead plate 23a. , a body 25 whose main component is bottomed cylindrical glass.
The output section 26 constitutes a vacuum container.

Inside this container, an input substrate 28 having an X-ray excited phosphor layer and a photocathode surface 21, a grid 29, an anode 30, and an output phosphor screen 31 are arranged in order from the top of the figure while maintaining a predetermined positional relationship. ing.

The input window 24 of the vacuum vessel is made of aluminum (Al) or A [with about 0.5% or more of Si, Cu to increase strength.

It is an A7 alloy (hereinafter simply referred to as AA material) containing at least one of Mn and Mg, and has a thickness of 0.5 to 2.0 mm.

The input window 24 has a convex structure that bulges outward in a spherical shape, but the input window 24 is not limited to this, and may have a flat shape in the case of a small tube.

Now, this input window 24 has a peripheral edge 4 having a plane perpendicular to the tube axis.
1, and this edge portion is hermetically sealed to an intermediate metal ring 42 having a crank-shaped half cross section by a method described later.

On the other hand, the open end 2 of the glass cylindrical insulator 25a of the body 25
A sealing ring 43 made of cylindrical Kovar is hermetically welded to the ring 5b, and its open end can tightly fit and contact the outside of the cylinder part 42a and flange 42b of the intermediate metal ring 42. Cylinder part 43a
1 and a flange 43b are provided, respectively.

When assembling the tube, after arranging each electrode, the intermediate metal ring 42, which is integrally hermetically sealed to the input window 24, and the Kovar sealing ring 43, which is integrally joined to the body 25, are connected to each other. Fitted, both flanges 42b, 43b
The tip is hermetically sealed around the entire circumference by localized heating welding such as inert gas arc welding.

This sealing part is designated by reference numeral 44, and this welded part is also used to fix the tube 21 and the outer magnetic shielding material 22.

The intermediate metal ring 42 is Kovar remainder A IJ song 3
A material that is easy to weld with iron (Fe) or F
e-Ni-Cr alloy (stainless steel), Fe-Ni-Cu
alloy (ferromagnetic material such as Par 70), or Fe
Fe alloys (such as -N i -Co alloys (Kovar)
(Hereinafter, simply referred to as Fe material) is used, and its thickness is 0.
5 to 2.0 mm is appropriate.

Next, the input window 24 made of AA material and the intermediate metal ring 42 made of Fe material.
The air-tight joint with the following will be described according to a preferred manufacturing method.

First, a Ni plating layer 45 is deposited on the entire surface of the intermediate metal ring 42 in advance.

This Ni plating layer has a thickness of 100 μm or less, preferably about 5 μm or less.
The thickness is 20 μm.

Then, as shown in FIGS. 3 and 4, the heating heater 4
6.47 between a pair of upper and lower press devices 48 and 49, each thoroughly degreased and cleaned part is pressed from the bottom of the figure to the flat part 4201 of the intermediate metal ring 42 with the Ni plating layer, the manual window input window 41, and The washer rings 50 made of a metal material having a softening temperature higher than that of the A7 material of the input window, such as Fe material or Ni material with a thickness of 0.2 to 1.071 m, are stacked and arranged in the order of are placed so that they are in contact with each other.

Ring-shaped tips 48a, 49a of press devices 48, 49
is the width equivalent to the width of the airtight joint or the lower side 4
The dimension is selected to be slightly wider than 8a.

In this embodiment, the width of the washer ring 50 is made wider than the width of the tip 49a of the upper press device.

A heating power source 51,52 is connected to the heater of each press device to raise the temperature.

The press device is made of a material with excellent hardness and heat resistance, such as an Fe alloy.

Further, the temperature of each tip 48a, 49a is, for example, about 580° C. on the lower side 48a in the figure, which is in contact with the intermediate metal ring 42, and the temperature on the upper side 48a, which is in contact with the input window AA material via the washer ring 50.
a to about 500°C, and the metals to be joined to about 470°C.
℃.

This temperature difference prevents the input window from overheating.
Deformation can be prevented.

Simultaneously with this heating, pressure is applied from the top and bottom of the figure as indicated by F in a press device and held for several minutes or more.

The pressurizing force F is controlled by the temperature of the joint, and is 470°C.
1,100kg/i at , 250 at 630℃
It is desirable to add at a rate of about 11 yen per kg/c.

As a result, the intermediate metal ring 42 made of Fe material and A7
The input window made of aluminum is thermocompression bonded with a Ni thin layer 45 interposed therebetween, thereby achieving an airtight connection.

A cross section of this joint is observed as shown in FIG.

What can be noted is that the L' material of the input window 24 is thinly compressed and plastically deformed in the area pressurized by the upper and lower press device tips 48a and 49a shown by the dashed line, and in this state, the intermediate metal ring 42 is applied to this area. The washer ring 50 is not airtight, but is attached to the AA material of the input window.

Note that the washer ring 50 and the upper pressing device 49a do not adhere to each other at all.

This washer ring 50 thus helps the airtight thermal pressurization of the input window A7 material and the intermediate metal ring, and also has the function of preventing adhesion between the Al material and the press device, and reinforcing the peripheral edge of the input window, so that it deforms. It has the function of suppressing

Therefore, this washer ring may be attached to the pipe product as is, or if it can be removed without damaging the hermetic joint between the input window and the intermediate metal ring, only the washer ring may be removed after these have been joined. It's good to leave.

Since this washer ring functions as described above, it is desirable that it has the same hardness as the material of the intermediate metal ring 42 or the press device.

In addition, an example of the results of measuring the metal element profile of a cross-sectional portion heat-pressed by the above method using an X-ray microanalyzer will be introduced with reference to FIG.

In the figure, the horizontal axis of the characteristic diagram represents the position of the press contact portion along the X-X line, and the vertical axis represents the detected amount.

From this result, it can be seen that Fe, Ni, and A7 exist with relatively clear boundaries between each other, and are not deeply diffused into each other's regions.

Therefore, it is said that there is no fear of forming a thick brittle intermetallic compound, and that a physically and mechanically stable thermocompression welding state is exhibited.

Furthermore, according to the above embodiment, the Ni thin layer 45 can be deposited on the entire surface of the intermediate metal ring 42 by plating, so the thickness and adhesion strength can be easily controlled, and the Ni thin layer 45 can be deposited as it is. Since airtight welding at the position 44 can be performed reliably and easily, this combined with the low cost of the material for the plating layer makes it extremely effective industrially.

Furthermore, since there is no need to form a thin metal layer on the input window made of a relatively thin Al material, manufacturing is easier.

Furthermore, since the input window and the intermediate metal ring are integrally bonded in advance, handling is easy. The present invention can also be applied to a configuration in which the input board 28 shown in the figure is omitted.

In the embodiment shown in FIG. 6, the radial width W1 of the washer ring 50 is set to be narrower than the width W2 of the tip 49a of the upper press device 49 that comes into contact with the washer ring.

Thereby, the airtight joint area between the input window 24 and the intermediate metal ring 42 can be made equal to the width W1 of the washer ring 50.

Therefore, by selecting the width W1 of this washer ring 50 as desired, the airtight joint width can be arbitrarily controlled.

In the embodiment shown in FIG. 7, Ni plating thin layers 51 and 52 are applied to both sides of the peripheral edge 41 of the input window 24 and the entire surface of the washer ring 50.

The thin Ni plating layer 51 applied to the peripheral edge of the input window 24 is kept outside the effective input surface so as not to attenuate the incident X-rays.

By applying a thin Ni plating layer to all three parts stacked in this way, the quality of thermocompression bonding can be further improved.

Furthermore, by using the same Ni plating layer, manufacturing is easy and airtight fitting is ensured.

The washer ring also adheres firmly, further increasing the reinforcement of the peripheral edge of the input window.

In the above embodiments, the case where Ni is used as the metal plating thin layer is described, but the invention is not limited to this, and the metal plating layer is not limited to this. They may be combined, thereby making it possible to perform stable thermocompression welding.

The appropriate values for the humidity and pressure at the joint in the heat pressure welding process are as described above when a Ni plating layer is formed, and when a Cu plating layer is formed. The humidity is 310°C and the pressure is 960 kg.
/cyst, pressure 520ky/ff at 500°C
It is best to set the ratio to 1.

In practice, the humidity is 250°C to 650°C, the pressure is 250°C to
It is assumed to be 1500 ky/i.

Note that A [if a vapor deposited layer is used, its thickness should be 300 μm]
The thickness is preferably 5 to 10 μm.

The embodiment shown in FIGS. 8 to 10 has the following configuration.

That is, first, a thin Ni plating layer 45 is applied to an intermediate metal ring 42 made of Fe material with a crank-shaped half cross section, and a thin Ni plating layer 45 is applied on the inner flat part 42c of the intermediate metal ring 42 made of Fe material with a crank-shaped half cross section.
[Place the intermediate ring 53, place the Ni-plated washer ring 50 on top of it, and press the upper and lower press devices 4.
8.49 and heat-press bonded in the same manner as in the previous embodiment.

Next, with the washer ring 50 on the inside of the tube, the peripheral edge 41 of the input window 24 made of AA material is fitted inside the first intermediate ring 53, and the same edge and the Al intermediate ring 53 are fitted.
The entire circumference is hermetically welded to the upper end portion 53a by a method such as AC (alternating current)-TIG welding.

The reference numeral 54 in the figure indicates the Al material that has been filled by this airtight welding.

In this embodiment, an intermediate ring 53 made of Al material and a gold metal ring 42 made of Fe material are welded under heat, and the intermediate ring 53 made of Ad material and an input window are further welded to form a vacuum vessel.

The washer ring 50 is used to ensure thermo-pressure welding of the A7 intermediate ring 53 and the gold metal ring 42 made of Fe material.

Airtight welding between the intermediate ring made of Al materials and the input window can be easily performed and is effective in preventing deformation of the input window.

The embodiment shown in FIG. 11 is configured such that the outer surface 53b of the AA intermediate ring 53 having a half-shaped cross-section is slightly separated from the inner surface of the intermediate metal ring 42 made of Fe material, and the input window 2
The peripheral edge 41 of the ring 4 is bent upward in the figure parallel to the tube axis and along the end 53a of the Al intermediate ring 53, and the entire circumference of both is hermetically welded as shown by reference numeral 54.

Since the welding part 54 is provided apart from the inner surface of the intermediate metal ring 42, welding is easy and airtight welding can be performed with only a local temperature rise relative to the input window, which further reduces the deformation of the input window. can be suppressed.

In the embodiment shown in FIGS. 12 and 13, the body 25 of the vacuum container is arranged, from the side closer to the input side 24, to a cylinder 55 made of Al material and having a large diameter part and a small diameter part integrated;
It is composed of an Al intermediate ring 56 made of L material, an intermediate metal ring 57 made of Fe material, a sealing ring 58 made of Fe material that can be easily hermetically sealed with glass or ceramic, and an output section insulator 25a made of glass or ceramic. ing.

First, the Al intermediate ring 56 and the Fe-based metal ring 5 are bent to the inside of the tube so that they come in contact with the tube axis in a plane perpendicular to the flanges 56a and 57a. Thermocompression bonding is performed through a metal thin layer made of one or more combinations selected from Cu and AA.

That is, as shown in FIG. 13, upper and lower press devices 48.
Both flanges 56a and 57a are sandwiched between the two flanges 56a and 57a, and a two-part hard metal ring 59 for preventing deformation of the outer container is fitted and fixed, and heated and pressurized.

Then, the outer peripheral edge 41 of the input window 24 made of Al material and the outwardly bent flange 55a of the cylinder 55 are connected with reference numeral 6.
AC-TIG welded as shown in 0, and cylinder 5
The lower flange 55b of No. 5 and the outwardly bent flange 56b of the Al intermediate ring 56 are welded by the same AC-TIG as shown at 61.

Finally, to airtightly close the vacuum container, the intermediate metal ring 57 made of Fe material and the sealing ring 58 are attached to the outer flanges 57b and 58a by AC-TIG as shown by reference numeral 62.
Weld.

Since these welds can be performed on the same materials and on the outside of the container, it is possible to reliably and easily achieve an airtight connection.

The body of the present invention, which forms a part of the vacuum container, is characterized by a mutually airtight sealing of dissimilar metal rings of Al material and Fe material, and an input window made of Al material and a glass or These Al
This can be applied to a structure in which the joint portion between the material and the Fe material is in one place or in multiple tubes.

For example, the present invention can be applied to a Kovar sealing ring that is directly bonded to a glass insulator, or to an Al material for an input window or an intermediate ring.

As described above, either the input window made of Al material or the intermediate ring made of other Al material bonded to this input window, or the intermediate metal ring made of Fe material hermetically bonded to glass or ceramic. , or Ni in both,
The present invention, in which a vacuum container is constructed by depositing one or more plating layers selected from Cu and Al and joining them airtightly by heat-pressure welding, can obtain a stable joint at a low cost, and can be manufactured in large quantities. Suitable for production.

In addition, by heat-pressure welding a washer ring as an auxiliary metal ring to the Al material, this airtight joint is further ensured, and it also serves as reinforcement for the relatively soft Al material, making it possible to create a highly practical radiation image intensifier tube. realizable.

In addition, by using a device with a built-in heater as a press device for hot pressure welding, it is possible to maintain the bonded part at a desired temperature with relatively high precision, while also preventing other parts of the Al material that are easily deformed. Undesirable overheating can be avoided and deformation can be suppressed.

Therefore, it is particularly effective for joining input windows made of thin l' material.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged view of its main parts, FIG. 3 is a longitudinal cross-sectional view of its manufacturing process, and FIG. 4 is an enlarged cross-sectional view of its joints. FIG. 5 is a profile diagram of Fe, Ni, and AA at the joint, FIG. 6 is a longitudinal cross-sectional view showing another embodiment of the present invention during the process, and FIG. 7 is a schematic diagram showing still another embodiment. FIG. 8 is a vertical cross-sectional view of the main part showing another embodiment, FIG. 9 is a cross-sectional view of the main part during the process, FIG. 10 is a cross-sectional view during the same process, and FIG. FIG. 12 is a longitudinal sectional view of a main part showing another embodiment, FIG. 12 is a longitudinal sectional view showing still another embodiment, and FIG. 13 is a sectional view of a main part during the process. 21...X-ray fluorescence intensifier, 24...A
L material input window, 25... Group trading department, 26...
Output section, 25a... Insulator, 41...
Input window periphery, 42.57...Gold metal ring in Fe material 43.58...Sealing ring, 53.
56... A7 material intermediate ring, 50...
Washer (auxiliary) ring, 45.51.52...
- Metal thin layer, 48.49...Press device.

Claims (1)

[Claims] A radiation input window made of IAA or A1 alloy (hereinafter referred to as Al material), and a part provided on the opposite side of the input window and used as an output section for deriving a radiation image conversion signal. A glass or ceramic insulator is connected to the input window and the insulator, and one end thereof is connected to the input window directly or through a first metal ring made of A7 material, and is perpendicular to the tube axis. and a second metal ring made of Fe material, the other end of which is hermetically sealed to the insulator either directly or through another ring made of Fe or Fe alloy (hereinafter referred to as Fe material). In the vacuum container of the radiation image intensifier tube, the input window or the first metal ring and the second
The airtight connection with the metal ring is achieved by coating the surface of the second ring to be joined with a plating or vapor-deposited metal thin layer of a metal selected from Ni, Cu, and Al. A radiographic image intensifier tube characterized in that windows or a first metal ring are overlapped and a joined part of the input window or first metal ring is pressed and joined to the thin metal layer with a plastically deformed yoke. vacuum container. 2. The vacuum container for a radiation image intensifier tube according to claim 1, wherein the thin metal layer has a thickness of 100 μm or less. 3 A radiation input window made of Al or A [alloy (hereinafter referred to as Al material), and a glass or ceramic insulator provided on the opposite side of this input window, a part of which is used as an output section for deriving a radiation image conversion signal. A part of the vacuum vessel wall connecting the body, the input window and the insulator, and one end thereof is hermetically connected to the input window directly or through a first metal ring made of AA material and in a plane perpendicular to the tube axis. , the other end is directly connected to the above insulator or Fe or Fe alloy (hereinafter referred to as Fe material)
In the vacuum container of the radiation image intensifier tube, the vacuum container is equipped with a second metal ring made of Fe material and hermetically sealed together through another ring made of iron. The airtight joint is achieved by coating the surface of the second metal ring to be joined with a plating or vapor-deposited metal thin layer of a metal selected from Ni, Cu, and Al, and forming the input window or the second metal ring on this metal thin layer. 1 metal rings are overlapped and the input window or the first metal ring is press-welded to the metal thin layer in a plastically deformed state, and the Fe of the input window or the first metal ring is A vacuum container for a radiation image intensifier tube, characterized in that an auxiliary ring made of a metal having a softening point higher than that of Al material is integrally pressed onto the outer surface on the opposite side of the second metal ring made of Al material. 4 A radiation input window made of Al or A1 alloy (hereinafter referred to as Al material), and a glass or ceramic insulator provided on the opposite side of this input window, a part of which is used as an output part for deriving a radiation image conversion signal. and a part of the vacuum vessel wall connecting the input window and the insulator, and one end thereof is hermetically connected to the input window directly or through a first metal ring made of Al material and in a plane perpendicular to the tube axis, The other end is directly connected to the above insulator or Fe or Fe alloy (hereinafter referred to as Fe material)
A method for manufacturing a vacuum container for a radiation image intensifier tube, comprising a second metal ring made of Fe material and hermetically sealed together via another ring made of iron. For the airtight joint with the ring, the surface of the second metal ring to be joined is coated with a thin metal layer selected from Ni, Cu, and Al by plating or vapor deposition, and the two are connected through this thin metal layer. A method for manufacturing a vacuum container for a radiation image intensifier tube, which is characterized by stacking each other in a plane perpendicular to the tube axis, and pressing the tube in the tube axis direction while sandwiching and heating it with a press device with a built-in heater to seal the tube tightly. . 5. Manufacturing a vacuum container for a radiation image intensifier tube according to claim 4, in which the joint portion is heated to a temperature in the range of 250 to 650°C and pressure-bonded with a pressure in the range of 250 to 150 kg7. Method. 6 The heating temperature of the press device is set so that the temperature of the pressurizing tip in contact with the input window or the first metal ring is lower than the temperature of the pressurizing tip in contact with the second metal ring made of Fe material to perform pressure welding. A method for manufacturing a vacuum container for a radiation image intensifier tube according to claim 4. 7 A radiation input window made of Al or AA gold alloy (hereinafter referred to as Al material), and a glass or ceramic insulator provided on the opposite side of the input window and partially used as an output section for deriving a radiation image conversion signal. and a part of the vacuum vessel wall connecting the high-power window and the insulator, and one end thereof is hermetically connected to the input window directly or through a first metal ring made of Al material and in a plane perpendicular to the tube axis, a second metal ring made of Fe material, the other end of which is hermetically sealed to the insulator directly or via another ring made of Fe or Fe alloy (hereinafter referred to as Fe material). In the method for manufacturing a vacuum container, the input window or the airtight joint between the first metal ring and the second metal ring is formed by attaching a material selected from among Ni, Cu, and AA to the surface to be joined of the second metal ring in advance. The above-mentioned input window or An auxiliary ring made of a metal with a higher softening point than the l material is interposed between the first metal ring and the press device, and these are simultaneously heated and pressurized in the tube axis direction to airtightly join them. A method for manufacturing a vacuum container for a radiation image intensifier tube.