JP3202295B2 - Non-evaporable getter for thin display tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-evaporable getter which is installed in a vacuum vessel of a thin display tube and functions to improve and maintain a high vacuum.

[0002]

2. Description of the Related Art As is well known, non-evaporable getters are incorporated (built-in) in various vacuum vessels such as electron tubes and lightings in order to improve and maintain a required high vacuum. As this type of non-evaporable getter, for example, Zr, T
Sheets, ribbons, or pellets obtained by pressing and sintering powders of so-called active metals such as i, Ta, Th or intermetallic compounds containing these metal elements have been put to practical use.

FIGS. 2 and 3 show a non-evaporable getter in the form of a sheet or ribbon 1a or a non-evaporable getter in the form of a pellet 1b mounted (built-in) in a vacuum vessel via a holding structure 2. FIG.
The non-evaporable getters 1a and 1b mounted (built-in) in the vacuum vessel as described above are usually heated to 400 ° C. to 1000 ° C. and activated, and the residual in the sealed vacuum vessel with the subsequent cooling. Adsorb gas and create high vacuum. On the other hand, when the functional component sealed in the vacuum vessel operates, the gas released from the inner wall surface and the functional component of the vacuum vessel is adsorbed and the inside of the vacuum vessel is maintained at a required high vacuum for a long time. Has a function to retain. The gas adsorption capacity of this type of non-evaporable getter depends on the activity of the getter material and the effective adsorption area.

[0004]

As described above, in the case of the conventional non-evaporable getter in the form of a sheet 1a or pellet 1b, both are formed by pressing and sintering. Otherwise, the pellets themselves may be easily damaged or broken. If the non-evaporable getter is damaged or broken, the powder or particles of the active metal constituting the non-evaporable getter is likely to be scattered in the vacuum vessel. When the vacuum vessel is an electron tube or a lamp, the scattered powder or particles of the active metal causes pressure resistance, electric leakage,
It causes failures such as increased noise and abnormal discharge. Also,
Since the non-evaporable getter in the form of a sheet 1a or a pellet 1b is formed by pressing and sintering, a form in which powders or particles of active metals constituting the non-evaporable getter are fused (fused) together. Has formed. That is, in the non-evaporable getter having the above-described structure, the powder surface or the particle surface (effective adsorption area) of the active metal exposed to the atmosphere is reduced, and the sufficient gas adsorption ability cannot be maintained or exhibited. It can be said that it is a fact.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and eliminates the risk of scattering of active metal particles and the like, which are the main components of a non-evaporable getter. Thin that can maintain and demonstrate gas adsorption capacity
It is an object of the present invention to provide a non-evaporable getter for a display tube .

[0006]

A thin display tube according to the present invention.
Use non-evaporable getter, a support having a plurality of voids extending through between both main surfaces were formed by using the fine powder of the active metal
Having granules, and supporting the granules on the support by pressure contact
It is not characterized by comprising a granular layer constituted by.

In the present invention, the support is preferably a non-magnetic metal mesh, preferably the mesh of the non-magnetic metal mesh is 10 to 1000 μm, and the non-evaporable getter is provided. Thickness is 0.1 ~ 0.4mm
In addition, it is desirable that the surface of the granule layer has an irregular shape of 2 to 20 μm.

[0008]

In the non-evaporable getter according to the present invention, fine particles of an active metal having a getter function are used as granules,
In addition, the granules have a configuration in which the granules are supported in a press-contact (compression-bonding) manner using, for example, a nonmagnetic metal mesh as a support. In other words, a support having a large number of voids penetrating between both main surfaces, such as a non-magnetic metal mesh, is used. The granules are pressed and supported on the mesh-shaped support, so that they exhibit strong integrity and are scattered.・ Because there is no fear of detachment,
On the other hand, it is possible to eliminate or avoid the reduction of the effective adsorption area due to the fusion of the fine particles or the granules of the active metal, and the non-uniform activation temperature due to the thermal conductivity of the support.
Therefore, even when mounted (built-in) in a vacuum vessel, it is possible to always exert an excellent function of improving and maintaining a high vacuum without impairing, for example, pressure resistance characteristics.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 (a) and 1 (b).

FIG. 1 (a) is a sectional view showing a configuration example of a non-evaporable getter according to the present invention, and FIG. 1 (b) is a plan view showing a configuration example of a non-evaporable getter according to the present invention. That
3 is a support having a number of voids penetrating between the two main surfaces,
For example, a non-magnetic metal mesh. Reference numeral 4 denotes a granule layer made of fine particles of an active metal supported on a required area surface of the nonmagnetic metal mesh 3 in a press-contact (compression-bonding) manner.

The non-evaporable getter having the above structure can be easily manufactured and configured as follows, for example. First,
As a support having a number of voids penetrating between the main surfaces,
For example, stainless mesh sheet 3 of about 1000 mesh
Prepare Next, an active metal having a getter action prepared in advance, for example, a granule having a particle size of 100 μm or less formed using fine particles of Zr ₂ Ni having a particle size of 40 μm or less,
The stainless steel mesh sheet 3 is thinly spread and arranged on a predetermined area surface. After that, it is applied to a press die whose pressing surface is processed into an uneven surface of about 10 μm, and the pressing pressure is 50 kg / cm ²
The non-evaporable getter having a configuration in which the granule layer 4 having a particle size of 100 μm or less is integrated with the surface of the predetermined region of the stainless steel mesh sheet 3 by the pressure bonding.

Next, in view of the mechanical strength of the non-evaporable getter constructed as described above, the granules composed of the fine particles such as Ti and Zr are almost completely formed on the surface of the predetermined area of the stainless steel mesh sheet 3. Even when shocks and vibrations that can be normally received are applied, for example, when mounted in a vacuum vessel, the scattering phenomenon of fine particles and the like accompanying the destruction or detachment of the granule layer 4 is recognized. I couldn't.

[0013] Further, the stainless steel mesh sheet 3
In the granule layer 4 composed of the fine particles of the active metal supported, the reduction of the surface area due to the fusion of the fine particles and the granules is small, and the effective adsorption area is almost equal to the sum of the surface areas of the single particles and is strong. It was also confirmed that the composition exhibited excellent gas adsorption ability in the state.

Further, the non-evaporable getter having the above structure is mounted in a vacuum-made container made of glass, evacuated to a required high vacuum, and then activated by high-frequency heating from the outside. No desorption or scattering of active metal fine particles or granules was observed, and the function of maintaining a high vacuum was maintained and exhibited by uniform activation. That is,
Conventional ribbon-shaped or pellet-shaped non-evaporable getters are activated by the high-frequency heating or the like, whereas the heating temperature is not uniform or the required temperature and time may not be partially satisfied, In the case of the non-evaporable getter according to the present invention, the reticulated sheet 3 or the like functioning as a support forms a loop in the high-frequency heating or the like for the activation so as to achieve a uniform temperature rise and activation as a whole. As it achieves, it retains and demonstrates functions that excel in high vacuum. In particular, when the support 3 is a non-magnetic metal mesh sheet,
A high frequency is easily applied, which is effective for uniform temperature rise and activation.

More specifically, the function of increasing the vacuum will be described. The non-evaporable getter according to the present invention, in which the amount of the same type of active metal that acts as a getter is selected and set, and a conventional ribbon-shaped (pellet-shaped) getter. The gas adsorption characteristics of the non-evaporable getter were measured and evaluated, and the results were as shown in the following table. The gas adsorption characteristics were evaluated at 800 ° C.
After activation for 10 minutes, conductance: 250 at room temperature (25 ° C)
H ₂ gas is introduced at cc / sec and the adsorption rate is indicated by the gas adsorption amount up to 100 cc / sec. The specific surface area of the non-evaporable getter is a value calculated backward from the gas adsorption amount. (Margin below) Table Specific surface area (mm ² ) Gas adsorption amount (Torr, cc) Conventional example (pellet type) 108 200 Example 1280 2300 As can be seen from the above table, the amount of active metal that acts as a getter is selected to be constant. The set and configured non-evaporable getter according to the present invention has a specific surface area about 10 times that of a conventional ribbon-shaped (pellet-shaped) non-evaporable getter, and has a specific surface area of about 10 times.
It has twice the gas adsorption capacity.

In the above embodiment, the stainless steel mesh sheet is used as the support. However, the mesh sheet may not be a nonmagnetic metal mesh sheet such as Ni, depending on the application and the place of attachment. lattice-like or random multi several through holes manufacturing sheet may be one that drilled. The thickness and size of these supports (getter region forming portion) is determined by applications such as the case for a thin-type display tube it is a thickness 0.2 to 0.3 mm. In addition, as active metals having a getter function, Zr, Ti, Ta, Th
Alternatively, any generally known active metal such as an alloy containing these metal elements can be used.

[0017]

As described above, the thin type according to the present invention is provided.
Non-evaporable getters for display tubes are not only thinner and smaller, but also eliminate the risk of getter material being scattered or desorbed even when subjected to shock or vibration. Trouble generation problems such as the risk of electrical leakage can also be largely avoided. In addition, since the specific surface area of the getter action region is also greatly increased, excellent gas adsorption ability is always maintained and exhibited.

[Brief description of the drawings]

FIG. 1 shows a configuration example of a non-evaporable getter according to the present invention, where (a) is a cross-sectional view and (b) is a plan view.

FIG. 2 is a cross-sectional view of a main part showing a mode in which a conventional ribbon-type non-evaporable getter is mounted.

FIG. 3 is a cross-sectional view of a main part showing an embodiment in which a conventional pellet type non-evaporable getter is mounted.

[Explanation of symbols]

1a Ribbon-type non-evaporable getter 1b ... Pellet-type non-evaporable getter 2 ... Retaining structure 3 ... Support having a large number of voids penetrating between both main surfaces 4 ... Granule layer composed of fine powder of active metal

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 29/94

Claims (4)

(57) [Claims] 1. A comprising a support having numerous voids extending through between both main surfaces, the granules formed using the fine powder of the active metal, the
Non-evaporable getter for a thin display tube, characterized in that it comprises a pressure to granular layer constituted by supporting the granules member said support. 2. A claimed in thin display tube for a non-evaporable getter of claim 1, wherein the support is non-evaporable getter for a thin display tube, which is a non-magnetic metal mesh. 3. The non-evaporable getter for a thin display tube according to claim 2, wherein the non-magnetic metal mesh forming the support has an aperture of 10 to 10.
A non-evaporable getter for a thin display tube , wherein the thickness is 00 μm. 4. The method of claim 1 or any one <br/> non-evaporable getter for a thin display tube as claimed in claim 3, wherein a thickness of the non-evaporable getter is 0.1 to 0.4 mm, and the condyles < A non-evaporable getter for a thin display tube , characterized in that the surface of the particle layer has an irregular shape of 2 to 20 μm.