JPS5810291Y2 - display tube envelope - Google Patents

Description

[Detailed explanation of the idea] This invention relates to an envelope for a display tube.

For example, a conventional fluorescent display tube having a structure as shown in FIG. 1a is known.

In the figure, there is a ceramic substrate 1, and on the main surface of this ceramic substrate 1, a display body 2 composed of a plurality of fluorescent segments is formed.

Further, a filament 3 for electron irradiation is stretched across from the display body 2, and a grid is provided between the filament 3 and the display body 2 to diffuse or control the electrons irradiated from the filament 3. 4 is placed.

A face glass 5 is bonded to the ceramic substrate 1 and covers the display body 2, grid 4, and filament 3, and the face glass 5 and the ceramic substrate 1 constitute an envelope of a fluorescent display tube. are doing.

Incidentally, in the envelope of the fluorescent display tube having such a structure, an exhaust hole 6 is provided in the ceramic substrate 1 for making the inside of the envelope a vacuum during assembly. As shown in detail in Figure 1, there is an M on the inside surface.
o A metallized layer 7, a Ni plating layer 8, and an Au plating layer 9 are sequentially formed, and solder 10 is filled as a sealing material.

On the other hand, in recent years, a glass substrate has been used instead of the ceramic substrate 1 in order to eliminate various disadvantages such as high cost and occurrence of warpage caused by the expansion of the area of the ceramic substrate 1 due to the increase in the number of digits in fluorescent display tubes. It has become.

However, forming an exhaust hole that is sealed with solder on a glass substrate is difficult because glass generally has a low melting point and a Mo metallized layer formed by high-temperature firing cannot be formed on the inner surface of the exhaust hole. This was extremely difficult due to the inability to form an Au plating layer that has good wettability with solder (also a Ni plating layer that has good adhesion between the Mo metallized layer and the Au plating layer).

Therefore, an object of this invention is to provide an envelope for a display tube in which an exhaust hole portion that can be sealed with a brazing material is formed in a glass portion constituting the envelope.

This invention will be explained in detail below using examples.

FIGS. 2a and 2b are explanatory diagrams showing one embodiment of the display tube envelope according to this invention.

First, in FIG. 2a, the same reference numerals as in FIG. 1a indicate the same materials.

The parts that differ from Fig. 1a are in the substrate constituting the envelope,
This substrate is made of a glass material (hereinafter, this substrate will be referred to as a glass substrate 11), and an exhaust hole portion 12 is formed in this glass substrate 11.

As shown in detail in FIG. 2, this exhaust hole portion 12 is formed by providing a through hole 11a in the glass substrate 11, and is a through hole located substantially within this through hole 11a, that is, a through hole 11a. The through hole 11a is arranged substantially coaxially with the through hole 11a.
A ceramic plate 13 having a through hole with a smaller diameter is
It has a structure in which the surface of the glass substrate 11 inside the envelope is fixed with a frit glass 14.

A Mo metallized layer 15 is provided on the inner surface of the through hole provided in the ceramic plate 13 and on the surface of the ceramic plate 13 exposed from the through hole 11a of the glass substrate 11.
, an N plating layer 16 and an Au plating layer 17 are sequentially formed, and the through hole is filled with solder 10.

An example of a method for sealing the exhaust hole after evacuating the inside of the envelope in the envelope of a fluorescent display tube having such a configuration will be described below with reference to FIG.

In the figure, a through hole 1 provided in a glass substrate 11 is shown.
A ring-shaped solder 10 having an outer diameter approximately the same as the diameter of the through-hole 11a is loaded into 1a, and the gas inside the envelope is exhausted through the through-hole of the ceramic plate 13 and the hole of the solder 10. At least the vicinity of the exhaust hole portion 12 is heat-treated to melt the ring-shaped solder 10.

The molten solder 10 flows over the 7 surfaces of the Ati plated layer and fills the through holes in the ceramic plate 13, as shown in FIG.

In this way, the through hole 11a provided in the glass substrate 11
If the exhaust hole portion 12 is formed by fixing the ceramic plate 13 having a through hole positioned therein to the glass substrate 11 via a frit glass, the exhaust hole portion 12 can be formed as in the conventional method. The through holes provided in the ceramic plate 13 can be sealed by filling them with solder.

Although the above explanation has been made using the case of a fluorescent display tube as an example, this invention is not limited to this, and can also be applied to the case of other display tubes such as discharge tubes. The same effect can be obtained by applying the present invention to any device having an exhaust hole sealed with a brazing material.

As explained above, according to this invention, a display tube that uses a glass plate instead of ceramic, which causes high cost and warping of the board, and that can be easily hermetically sealed with a brazing material. An envelope is obtained.

In addition, the bulge caused by the surface tension of the brazing filler metal is positioned within the through hole provided in the glass plate and can be prevented from protruding to the outside surface of the glass plate, so that the brazing filler metal is not damaged by external force. This can effectively prevent vacuum leaks from occurring.

Furthermore, the through holes provided in the glass plate can be used for positioning during loading of the brazing material, which has the advantage of improving work efficiency and precision.

[Brief explanation of the drawing]

FIGS. 1a and 1b are explanatory diagrams showing an example of a conventional display tube envelope, and FIGS. 2a and 3b and 3a and 3b are an embodiment of the display tube envelope according to this invention. FIG. 10...Solder, 11...Glass substrate,
11a...Through hole, 12...Exhaust hole portion, 13...Ceramic plate, 14...Frit glass, 15...Mo metallization layer, 1
6...Ni plating layer, 17...Au plating layer.

Claims (1)

[Scope of utility model registration request] In the display tube envelope, which has at least a portion made of glass and includes an exhaust hole portion that is sealed by filling a brazing material, the exhaust hole portion includes:
a through hole provided in the portion made of the glass;
A ceramic member is fixed to the glass inner surface of the through-hole portion with a frit glass, and the ceramic member is provided with a through-hole that is arranged approximately coaxially with the through-hole and has a diameter smaller than that of the through-hole. An envelope for a display tube, characterized in that a metallized layer is formed on the inner surface of the through hole and on the surface of the ceramic member at the portion exposed from the through hole around the through hole.