JPH0245961Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lead pin attachment structure for a fluorescent display tube.

The outline of the lead pin mounting structure conventionally used in fluorescent display tubes is shown in FIGS. 1 and 2. As shown in FIG. A plate substrate 1 consisting of a fritted glass 3 is placed on the plate substrate 1.
A vacuum tube 4 is formed by the sealed face glass 2, and a part of the electrode structure such as the filament 5, the grid 6, and the anode 7 coated with fluorescent material arranged in the vacuum tube 4 is used as a lead pin 8. The one led out directly to the outside of vacuum tube 4 and the first
As shown in Figure B, filament 5, grid 6
Wiring conductors 9 are formed on the plate substrate 1 in connection with each electrode such as the anode 7 and the like, contact pads 10 are provided at the ends of these wiring conductors 9, and lead pins 11 are connected to each of these contact pads 10. There is a device that utilizes spring properties and is attached by bringing its tip into pressure contact. Also,
As shown in FIG. 2, the end of each wiring conductor 9 is led out to the outside of the vacuum tube 4 on the plate substrate 1, and a clip-shaped lead pin 12 is attached to the end of each wiring conductor 9 with solder or conductive paste. Some are designed to be connected and installed. In FIG. 2, reference numeral 13 denotes an auxiliary adhesive made of epoxy resin or the like for reinforcing the connection between the wiring conductor 9 and the lead pin 12.

However, in the mounting structure shown in FIG. 1A, (1) Since the lead pin 8 penetrates inside and outside the vacuum tube 4, the lead pin must be made of a sealing material, and in order to maintain vacuum tightness, the lead pin must be made of a sealing material. Therefore, the surface oxidation (pre-oxidation) of the lead pin 8 must be strictly controlled. Further, if there are burrs or the like on the lead pin 8, vacuum leakage is likely to occur, so the manufacturing method for the lead pin is limited to photo-etching or the like. Pressing always produces burrs, and processes such as honing and chemical treatment are required to remove these burrs.

(2) Because it is integrated with the electrode structure, such as grids and filaments, the material usage rate is poor (many parts fall off and become waste).

(3) Since the lead pin 8 is surface oxidized,
Grid electrodes are difficult to weld. Also, since it is made of a sealed metal such as 426 alloy, the lead pins are susceptible to rust due to moisture. In order to prevent this and to facilitate soldering, solder plating or the like is applied to the lead pins, but this is difficult due to the strong surface oxidation.

It has drawbacks such as:

In addition to the drawbacks (1) and (3) mentioned above, in the case of FIG. 1B, the contact pad 10 is attached to the vacuum tube 4.
Because it is provided inside, the external dimensions become larger for the same display character size. Furthermore, since the connection is made by pressurized contact, it is difficult to do so when the current value is large, such as in the case of a filament, and in actual display tubes, each electrode has a hybrid structure in combination with that shown in FIG. 1A.

Furthermore, in the structure shown in FIG. 2, since the lead pin 12 is reattached outside the vacuum tube 4, a connecting portion is required, resulting in an increase in external dimensions. Further, it has the disadvantage that an auxiliary fixing agent 13 such as epoxy resin is required to increase the mechanical attachment strength of the lead pin.

The present invention was devised in view of the above-mentioned drawbacks of the conventional technology, and its purpose is to wire electrodes such as filaments and anodes within the sealed area between the plate substrate and the face glass without penetrating the lead pins into the interior of the vacuum tube. It is an object of the present invention to provide a lead pin mounting structure for a fluorescent display tube, which makes it possible to reduce the cost and size of the display tube by connecting it to a conductor.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a partially cutaway sectional view showing an embodiment of a lead pin mounting structure for a fluorescent display tube according to the present invention. In this embodiment, the ends 9a of each wiring conductor 9 formed on the plate substrate 1 are connected to the electrodes of the filament 5, the grid 6, and the anode 7 arranged in the vacuum tube 4, respectively. A recess 15 is formed at the tip of each lead pin 14 as shown in FIGS. 4A and B.
and holes 16 are provided, and the tip portions of these lead pins 14 are sandwiched between the middle portions of the frit glass 3 and are bonded and attached to the ends 9a of each wiring conductor 9, respectively. In this case, the recess 15 formed at the tip of each lead pin 14 has a concave cross section in the width direction, and the hole 16 intersects with the recess 15 to form a rectangular shape.

In the assembly process of such a lead pin attachment structure, first, the end surface 14a of the tip of the lead pin 14 is bonded to the end 9a of each wiring conductor 9 formed on the plate substrate 1 with a conductive adhesive or the like. . Then, frit glass 3 is applied to the tip of the lead pin 14 so as to cover it. Thereafter, the calcined face glass 2 is superimposed on the frit glass 3 and the frit glass 3 is processed and fired, so that the plate substrate 1 and the face glass 2 are combined into the frit glass 3.
At the same time, each wiring conductor 9 and lead pin 14 are integrally attached.

According to such a lead pin mounting structure, the lead pin 14 does not penetrate into the vacuum tube 4, so that the sealing portion between the plate substrate 1 and the face glass 2 is formed by the frit glass portion 3a as shown in FIG. 2, as shown in FIG. Moreover, the frit glass portion 3b that wraps around the recess 15 and hole 16 formed at the tip of the lead pin 14 further increases the vacuum tightness and the mechanical attachment strength to the lead pin. In addition, since the lead pin 14 does not penetrate into the vacuum tube 4, the material of the lead pin does not necessarily need to be an expensive sealing metal such as 426 alloy, and there is no need to oxidize the surface in advance, and there is some burr on the lead pin. It can be used even with poor surface roughness, which is advantageous in reducing costs. Furthermore, compared to the structure shown in FIG. 2, an auxiliary fixing agent such as an epoxy resin is not required, and the manufacturing process is simplified. Furthermore, when compared with the same display character size, the outer shape of the display tube can be made smaller, and the viewing angle can be increased with the same outer shape.

Note that the present invention is not limited to the above-mentioned embodiments; if a conductive adhesive with strong adhesion strength is used, it can be applied to the face glass without covering each pin attachment part on the board side with fritted glass. After applying the frit, a calcined face glass can be directly covered and sealed. Furthermore, either the recess 15 or the hole 16 may be provided at the tip of the lead pin.

Furthermore, as shown in FIG. 5, a clip pin 17 whose tip part holds the plate substrate 1 is used as a lead pin, and this clip pin 17 is inserted into the intermediate portion of the frit glass 3 that seals the plate substrate 1 and the face glass 2. A structure in which the plate substrate 1 is attached so as to be sandwiched therebetween can also obtain the same effect as the above-described embodiment.

As explained above, according to the lead pin mounting structure according to the present invention, the wiring conductor of the internal electrode and the tip of the lead pin as the external lead are sandwiched in the sealed part between the plate substrate and the face glass that constitute the vacuum tube. By providing a concave portion and/or hole at the tip of the lead pin, the mechanical attachment strength to the lead pin is increased, and since the lead pin does not penetrate into the vacuum tube, the lead pin Relatively inexpensive metal can be used as the display tube, and no extra space is required for the connection part, which has the effect of reducing the cost and size of the display tube.

[Brief explanation of the drawing]

1A, B and 2 are partially cutaway sectional views showing an outline of a conventional lead pin mounting structure, FIG. 3 is a partially cutaway sectional view showing an embodiment of the lead pin mounting structure according to the present invention, and FIG. Figures A and B are an enlarged plan view and side view of the tip portion of the lead pin shown in Figure 3, and Figure 5 is a partially cutaway sectional view showing another embodiment of the present invention. 1... Plate substrate, 2... Face glass,
3... fritted glass, 4... vacuum tube, 5... filament, 6... grid, 7... anode,
9... Wiring conductor, 14... Lead pin, 15...
Recess, 16... Hole, 17... Clip pin.

Claims (1)

[Scope of utility model registration request] A vacuum tube is formed by a plate substrate and a face glass sealed with a low melting point glass on the plate substrate, and a plurality of electrodes such as a filament and an anode are disposed inside this vacuum tube, and are connected to the plurality of electrodes respectively. The end of each wiring conductor formed on the plate substrate is led out to the middle part of the sealing part between the plate substrate and the face glass, and connected to the tip of each lead pin at this part in a pinched state. 1. A lead pin mounting structure for a fluorescent display tube, wherein each of the lead pins has a recess and/or a hole at a tip end thereof.