JPS5833651B2 - How to attach stud pins to cathode ray tube panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for attaching stud pins to a cathode ray tube panel.

In a cathode ray tube such as a color television picture tube, as shown in FIG. A means 2 for determining the arrival position of the image is provided, for example a shadow mask or an aperture grill with circular holes or slits.

This means 2 is usually attached to the panel 1 by directly sealing a truncated conical metal stud pin 3 or by fritting a ceramic stud pin 3 on the inner surface of the skirt portion 1S around the panel 1. A leaf spring 14 attached to the frame of the means 2 is fitted and attached to this pin 3.

To attach the frit to the panel 1 of the stud pin 3, normally, a liquid frit sealant containing a mixture of frit and binder is applied to the surface, that is, the bottom surface of the pin 3. The pin 3 is pressed onto the panel 1 at a predetermined position before the applied liquid frit material dries, that is, before the binder solvent in the frit material evaporates. In this state, the frit material is dried to temporarily fix it, and then the jig is removed, a clip that can withstand high temperature heating is fitted into the skirt part IS of the panel 1, and the pin 3 is
is held in the above position, and in this state, for example, 10
Raise the temperature at a heating rate of ℃/min, and increase the temperature by 30℃ at 430℃.
Hold for 70 minutes.

In this way, the binder in the frit material is decomposed and dissipated, and the frit is vitrified and then crystallized.The pin 3 is firmly fixed at a predetermined position on the panel 1, that is, on the inner surface of the skirt portion 1S. Ru.

The pin 3 fritted in this way can withstand subsequent high-temperature heat treatment, that is, heating steps that occur during the manufacturing process of cathode ray tubes, such as frit sealing between the panel and funnel of the cathode ray tube, heating during exhaust, etc.

However, when the pin 3 is fritted by such a method, there are various drawbacks.

First, a liquid frit sealant is applied to the pin 3, and before it dries, it is crimped to a predetermined position on the inner surface of the skirt portion 1S of the panel 1, so that the liquid frit sealant is applied from the bottom of the pin 3 to the panel. The liquid frit sealant tends to drop onto the pin 3 and adhere to the pin 3, requiring time and effort to wipe it off, and also hinders the application of an appropriate amount of the liquid frit sealant to the pin 3.

Furthermore, with the pin 3 placed at a predetermined position on the panel 1,
Since heating is performed to decompose the binder and vitrify/crystallize the frit, air bubbles are generated in the layer of the frit material between the fixed surfaces of the pins 3 and the panel 1 due to the generation of gas as the binder decomposes. However, this method has the drawback of lowering reliability, such as lowering the fixing strength of the pin 3.

The present invention aims to provide a method for attaching stud pins to a cathode ray tube panel that eliminates these drawbacks.

That is, in the present invention, first, as shown in FIG. 2, when attaching the stud pin 3 to the panel 1, the frit sealing material is applied to the surface 3a, that is, the bottom surface.

This frit sealing material is a mixture of a frit (powder) and a binder as usual, and is made into a liquid by the solvent of the binder, but in particular in the present invention,
After applying this liquid frit sealing material to the surface 3a of the pin 3, the solvent in the frit material is evaporated and dried, the binder in the frit sealing material is dispersed, and the frit is further heated and baked until it is in a semi-molten state. and face 3 of pin 3
The binder is removed and a semi-melted frit layer 4 is deposited on a.

As shown in FIG. 3, the pin 3 with the semi-melted frit layer 4 attached thereto is placed at a predetermined position on the panel 1, that is, at a predetermined position on the inner surface of the skirt portion 1S of the panel 1, and the frit layer The 4th side is pressed against the inner surface of the skirt portion 1S, and in this state, it is heated to crystallize the frit.

Pin 3 is a ceramic pin made of forsterite, alumina, etc. that matches the thermal expansion coefficient of the glass panel, or
2Ni 6Cr-balance Fe alloy, 18Cr-balance F
Metal pins such as e-alloy can be used.

The frit sealing material is a thermally devitrified low-melting glass, such as A
Frits such as SF-1304 and ASF-1307 (all trade names) mixed with a binder such as a mixture of nitrocellulose and isoamyl acetate may be used.

Further, the firing treatment for semi-melting the frit sealing material is performed at 350°C to 400°C.

Note that the frit layer 4 after being fired in this way has the following properties:
The binder has disintegrated and been removed.

As described above, the pin 3 having the semi-melted frit layer 4 is pressed against a predetermined position of the panel 1 and heated to a temperature at which the frit crystallizes. As shown in FIG. 5, this can be done by fitting the clip 7 into the skirt portion 1S of the panel 1 with the pin 3 in place at a predetermined position.

This clip I may be formed by providing a notch 7a in one half of a U-shaped metal plate, as shown in FIG. 6, for example.

Then, insert this clip 7 from the open end of the skirt portion 1S, fit the head of the pin 3 into the notch 7a, and
is crimped onto the inner surface of the skirt portion 1S.

Heating for crystallization of the frit is performed at a heating rate of, for example, 10°C/min from room temperature, as shown by curve 5 in Figure 4.
For example, the temperature at which the frit is crystallized is 43°C as shown in
Heat to 0°C and hold at this temperature for 30 to 70 minutes, then cool.

Curve 6 in FIG. 4 shows the differential thermal curve of the frit.

An exothermic reaction is occurring in parts a, b, and c of this curve,
In addition, crystal precipitation also occurs in portions c and c.

When the frit is crystallized by such heat treatment, the pins 3 are firmly fixed to the panel 1, and the fixing strength of the pins 3 will not be reduced even by high-temperature heating thereafter.

The heat treatment for crystallizing the frit can also be performed by pressing the pins 3 against the panel 1 that has already been molded, for example at room temperature, and heating it again. A pin 3 preheated to about 350 to 400 degrees Celsius is applied to the panel 1, which is still heated at about 400 to 550 degrees Celsius immediately after being molded by, to crystallize the frit 4, which also serves as a slow cooling process for the panel. It is also possible to fix the pin 3 to the panel 1.

As described above, according to the method of the present invention, since the frit layer 4 is applied to the stud pin 3 in a semi-melted state, that is, in a dry state, the frit pin 3
Since the application to the panel 1 and the attachment to the panel 1 can be performed independently of the work, the application work can be easily mechanized and mass production becomes possible.

In addition, when the frit is brought to the panel 1 in a liquid state as in the past, contamination may occur due to dripping of the frit material onto the panel 1, or non-uniformity or shortage of the frit material on each pin 3 and resulting sticking. A decrease in strength can be avoided.

Furthermore, since the frit layer 4 is in a dry state when positioning the pin 3 at a predetermined position on the panel 1, the panel 1 is automatically set at a predetermined position;
By automatically bringing the pins 3 to a predetermined position on the panel 1, the frit attachment of the pins 3 to the panel 1 can be automated.

Furthermore, according to the method of the present invention, when the pin 3 is attached to the panel 1, the binder in the frit material has already been removed, so there is no risk of air bubbles being generated between the two when the binder decomposes. As described above, it is possible to fix the panel by pressing the pin 3 having the frit layer 4 thereon by utilizing the heating state immediately after the panel is formed.

Incidentally, if the pin 3 is applied to the heated panel 1 through the frit sealing material containing a binder, the binder will rapidly decompose and air bubbles will be generated, making the panel unusable.

Furthermore, since there is no fear that lead oxide in the frit composition, for example, will be reduced by the gas generated by the decomposition of the binder, there is also the benefit of avoiding a decrease in adhesive strength due to this and improving reliability.

As mentioned above, according to the method of the present invention, the various drawbacks of the conventional method mentioned at the beginning can be completely eliminated, and furthermore, manufacturing can be easily automated and mass production can be achieved. be.

[Brief explanation of drawings]

Fig. 1 is a rear view showing how the electron beam arrival position determining means is attached to the panel, Fig. 2 is a side view of a stud pin in one step of the method of the present invention, and Fig. 3 is for explanation of the method of the present invention. FIG. 4 is a heating programming diagram, and FIG. 5 is a partially sectional side view showing an example of means for press-fitting the stud pin to the panel, which is applied to the method of the present invention. FIG. 6 is a perspective view of an example of the fixing means. 1 is a cathode ray tube panel, 1S is a skirt thereof, 2 is means for determining the electron beam arrival position, 3 is a stud pin, and 4 is a frit layer.

Claims (1)

[Claims] 1. To attach a stud pin to a cathode ray tube panel, apply a frit sealant to the surface of the stud pin in advance, bake it until the frit in the frit sealant becomes half-melted, and then attach the stud pin to which the half-melted frit is attached. , fixed in a predetermined position on the panel by a U-shaped clip inserted into the skirt portion of the panel, heat-treated in this state to crystallize the frit, and fixed the stud pin in a predetermined position on the cathode ray tube panel. A method for attaching stud pins to a cathode ray tube panel, characterized in that the stud pins are fixed to the panel.