JPH0459729B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a manufacturing method for manufacturing a flat display device by improving the mutual positioning accuracy of electrodes, and the present invention relates to a manufacturing method for manufacturing a flat display device by improving the mutual positioning accuracy of electrodes. It is an object of the present invention to provide a manufacturing method that improves the positioning accuracy of electrodes by solving the above problems.

First, the configuration of a flat display device manufactured by the manufacturing method of the present invention will be briefly described. The structure of the flat display device is schematically shown in FIGS. 1 to 5.
In Figure 1, 1 is the phosphor surface, 2 is the cathode, and 3 is the phosphor surface.
is a coupling spacer, and 4 is an electrode. The electron beam emitted from the cathode 2 is horizontally and vertically deflected and intensity-modulated by various electrodes 4, and reaches the phosphor surface 1, causing it to emit light.

The electrode 4 has a hole 1 as shown in Figures 2 and 3.
6, 16' are provided, and the electron beam passes through these holes 16, 16'. The stiffness of the electrode 4 depends on the shape and number of holes 16, 16'. Taking electrodes 5 and 6 shown in FIGS. 2 and 3 as an example, electrode 5 has greater rigidity against tension and compression in the horizontal direction shown in the figures than electrode 6. This is electrode 5
This is because the stiffness corresponds to the stiffness of the crosspiece 19 against simple tension and compression, whereas the stiffness of the electrode 6 corresponds to the bending rigidity of the crosspiece 20. A thin and long shape like the crosspiece 20 bends easily, and its bending rigidity is extremely low.

Further, as shown in FIG. 4, the bonding spacer 3 has a structure in which an insulating material 8 for thickness adjustment is adhered to a base metal 9, and a frit glass 7 for bonding is applied thereon. FIG. 5 shows a state in which the electrode 5 with high rigidity, the electrode 6 with low rigidity and the coupling spacer 3 are combined. Electrodes 5 and 6 are bonded spacers 3
It is sintered and fixed by frit glass 7 coated on the surface. At this time, each electrode 5, 6 must be correctly positioned with respect to each other, and dimensions a and b in FIG. 5 must be equal and correspond to the printed pattern pitch (not shown) of the phosphor 1. This is required.

The electron beam travels through the window W at right angles to the plane of the paper, but the influence of electrode precision on the direction of the electron beam is more sensitive in the X direction.Due to the printed pattern of the phosphor 1, the electrode precision in the X direction is It must be higher compared to the y direction.

The positioning of each electrode 5, 6 is performed by inserting a pin into a positioning hole 10 that is precisely machined in the electrode 5, 6. The coupling spacer 3 is used to insulate the electrodes 5 and 6 and to maintain and fix the electrodes at a predetermined distance. If a bonding spacer 3 having the structure shown in FIG. 4 is sandwiched between each electrode 5 and 6 and heated under a load P as shown in FIG. 1, each electrode will be fixed by a frit glass 7. can do. Note that the frit glass 7 is completely crushed after melting and does not contribute to the electrode spacing, so the insulator 8
The thickness hf is the distance between the opposing electrodes 5 and 6.

The above is the general structure and manufacturing method of the flat display device.

Next, problems related to the accuracy of positioning between electrodes that occur in the above configuration and manufacturing method will be explained.

Fritted glass is fired at 400-500℃,
Even if the electrodes are precisely positioned relative to each other at room temperature, this will be disrupted at firing temperatures. This is caused by differences in thermal expansion coefficients, differences in rigidity, etc. of each electrode. This will be explained with an example.

Rather than firing and fixing the electrodes all at once, it is more accurate to manufacture the electrodes by dividing them into units, firing and fixing each unit, and then firing the units together. Therefore, here we will consider the accuracy defects that occur during the firing process of the unit. FIG. 6 shows a conventional method for fixing electrodes 5 and 6 by firing and fixing them with a bonding spacer 3. Here, 11 is a weight, 12 is a substrate, 13 and 13' are sheets for preventing the influence of elongation on the weight 11 and the electrodes 5 and 6 of the substrate 12,
15 is a positioning pin. Electrodes 5 and 6 are the second
As shown in Figures 3 and 3, there are two types, one with high rigidity against elongation and the other with low rigidity.

In this case, looking at the elongation of each electrode after sintering, electrodes 5 and 6 both elongate compared to before sintering, but the elongation of the two is different. Then, the positioning accuracy deteriorates by the amount of this different elongation. Positioning accuracy of several tens of μm is required, but due to the above phenomenon,
Accuracy of only about 100 μm is often achieved.

The present invention has been made to solve the above-mentioned problems, and will be described in detail below with reference to embodiments thereof.

Factors that affect the elongation of the electrodes 5 and 6 include the respective thermal expansion coefficients of the base metal 9 of each electrode 5 and 6 and the coupling spacer 3, the insulator 8, the sheets 13 and 13', the weight 11, and the substrate 12. Although rigidity and temperature unevenness of each part are considered, what essentially influences the coefficient of thermal expansion and rigidity of the electrodes 5 and 6, the sheets 13 and 13', and the coupling spacer 3. Already crystallized fritted glass is used as the insulator 8, and the electrodes 5,
6 and the sheets 13 and 13' are made of so-called 426 alloy, the coefficient of thermal expansion of the insulator 8 is
Since it is smaller than the 426 alloy, the coefficient of thermal expansion of the entire spacer is smaller than that of the electrodes 5 and 6.

Taking this into consideration when looking at the heating process, we find that the electrode 5 has relatively high rigidity, so the coupling spacer 3
Despite the restraint of the sheet 13', it expands almost according to its own coefficient of thermal expansion, that is, the coefficient of thermal expansion of the 426 alloy. On the other hand, since the electrode 6 has low rigidity, it expands under the influence of the thermal expansion of the bonding spacer 3 and the sheet 13 that sandwich it. 426 alloy and Insulator 8 are shown.
This is a small value compared to the elongation of the electrode 5. In this state (400 to 500°C), the frit glass 7 joins the joining spacer 3 and the electrodes 5 and 6.

Regarding the subsequent cooling process, since the electrode 6 is bonded to the spacer 3 and its own rigidity is small, its contraction almost follows the contraction of the bonded spacer 3. Since the electrode 5 is relatively rigid, it exhibits an intermediate shrinkage of the bonding spacer 3 and the 426 alloy from which the electrode 5 is made.

In the end, when these heating and cooling processes are taken together, the electrode 5 expands due to almost its own thermal expansion, and when it contracts, the bonding spacer 3 restrains the contraction, so that it will expand after firing compared to before firing. The result is that the electrode 6 stretches to an intermediate value between the bonding spacer 3 and the sheet 13, ie greater than the elongation of the bonding spacer 3, and contracts as the bonding spacer 3 contracts. However, since electrodes 5 and 6 have different expansion and contraction mechanisms, the amount of expansion will be different.

The above is the mechanism by which the electrodes 5 and 6 elongate.

Next, an embodiment of the present invention that takes measures against the above-mentioned results will be described. FIG. 7 shows a state in which a manufacturing method according to an embodiment of the present invention is carried out. In this method, a spacer 14 for elongation adjustment is inserted between the electrode 6 and the sheet 13. The rest is the same as the conventional case shown in FIG. 6, so the explanation will be omitted.
The spacer 14 for adjusting the elongation is replaced by the electrode 6 with low rigidity.
The feature of this manufacturing method lies in the fact that it is adjacent to .
The thermal expansion of the electrode 6, which has low rigidity, during the heating and firing process is affected by the thermal expansion of the bonding spacer 3 sandwiching it and the elongation adjustment spacer 14. Therefore, by changing the thermal expansion coefficient of the elongation adjustment spacer 14, , the amount of thermal expansion of the electrode 6 can be adjusted. Therefore, the coefficient of thermal expansion of the spacer 14 for elongation adjustment is set to a value such that the coefficient of thermal expansion of the electrode 6 with low rigidity is equivalent to that of the electrode 5 with high rigidity. When the elongation adjustment spacer 14 is used only for elongation adjustment of the electrode 6, it must be separated from the electrode 6 after firing and fixing. In this case, a mold release agent is applied to the side of the elongation adjusting spacer 14 in contact with the electrode 6 so that even if the frit glass 7 of the bonding spacer 3 overflows, the elongation adjusting spacer 14 and the electrode 6 do not come together. When the spacer 14 for elongation adjustment is used in conjunction with the electrode 6, frit glass may also be applied to the spacer 14 for elongation adjustment.

If the spacer 14 for adjusting the elongation is placed adjacent to the electrode 5 having high rigidity, there is no elongation adjusting effect on the electrode 5. This is because the electrode 5 has high rigidity.
The spacer 14 for elongation adjustment is an electrode 6 with low rigidity.
It is only effective if it is placed adjacent to the .

The results of the experiment are shown in FIG. In this experiment, the spacer 14 for elongation adjustment had the same structure as the bonding spacer 3 shown in FIG. 4. hf is the elongation adjustment spacer 1 of the bonding spacer 3 shown in Fig. 4.
4 is the thickness of the insulator 8, and hm is the thickness of the base metal 9. The coefficient of thermal expansion of the spacer 14 for elongation adjustment is adjusted by the thickness of the insulator 8 (the thicker it is, the smaller the coefficient of thermal expansion is), and the thickness of the insulator 8 is taken as the horizontal axis (therefore, hf/hm is large). The vertical axis is the electrode elongation per 75 mm of electrode length after firing. What is shown as electrodes 5 and 6 is a spacer 14 for adjusting the elongation adjacent to the electrodes 5 and 6.
It shows that it has been placed.

This result is effective for the electrode 6 having low rigidity, as described above. That is, the electrode elongation changes in response to a change in the coefficient of thermal expansion of the elongation adjusting spacer 14. It is shown that this effect is not so great for the electrode 5 having high rigidity. That is, the electrode elongation does not change even if the thermal expansion coefficient of the elongation adjusting spacer 14 changes.
Also, as a matter of course, there is a spacer 14 for adjusting the elongation.
As the coefficient of thermal expansion of the electrode 6 decreases, the elongation of the electrode 6 also decreases. From this result, in this case,
This shows that if the thickness ratio hf/hm of the insulator 8 and the base metal 9 is set to 1.2, it is possible to equalize the elongation of the electrode 6 after firing and that of the electrode 5, which is a result of the manufacturing method of the present invention. Its effectiveness has been proven.

In addition, in the above embodiment, the case where two electrodes are combined by firing to create one unit was explained as an example, but when all the electrodes are fired and fixed at once, the rigidity can be similarly reduced. It is clear that a similar effect can be obtained by arranging a spacer 14 for elongation adjustment adjacent to a small electrode. In this case, the elongation adjusting spacer 14 may serve as the coupling spacer 3 to connect the electrodes.

As described above, according to the present invention, an elongation adjustment spacer having an appropriate coefficient of thermal expansion is arranged adjacent to an electrode with a low rigidity, so that the amount of elongation of this electrode is adjusted to the amount of elongation of an electrode with a high rigidity. By doing so, it becomes possible to position the electrodes with high precision and easily.

Furthermore, according to the present invention, by selecting a spacer for elongation adjustment to have a predetermined coefficient of thermal expansion depending on the print pattern pitch of the phosphor and the pattern accuracy of the rigid electrode, the rigid electrode can be arbitrarily adjusted. The electrodes can be expanded and contracted, and the mutual positioning of the electrodes can be made highly accurate.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the configuration of a flat display device;
Figures 2 and 3 are plan views of a rigid electrode and a small electrode used in the device, Figures 4a and b are plan views and front views of a coupling spacer used in the device, and Figures 5a and 5 are b is a cross-sectional plan view and a side view showing a combined state of the electrodes and coupling spacers in the same device, FIG. The figure is a side view of a part of a flat display device according to an embodiment of the method for manufacturing a flat display device of the present invention, and FIGS. 8a and 8b show electrode expansion adjusted by the expansion adjustment spacer. FIG. 3 is a characteristic diagram showing experimental results. DESCRIPTION OF SYMBOLS 1... Fluorescent substance, 2... Cathode, 3... Coupling spacer, 4... Electrode, 5... Highly rigid electrode, 6
...Electrode with low rigidity, 7... Fritted glass, 8
... Insulator, 9 ... Base metal, 10 ... Positioning hole, 11 ... Weight, 12 ... Substrate, 13,1
3'...Sheet, 14...Spacer for adjusting elongation,
15...Positioning pin.

[Claims]

1. A method for molding a color picture tube mask, in which a plurality of masks each having a large number of apertures are relatively fixed with a filler, the main surfaces having the apertures are simultaneously press-molded into a curved shape, and then the filler is removed. , the plurality of masks are fixed in a container consisting of an injection board having an injection port and a ventilation hole for the filling material, and a holding plate, and the pressure inside the container when the filling material is injected is controlled by the filling material. A method for molding a mask for a color picture tube, characterized in that the injection pressure is lower than that of the injection pressure. 2. The method for molding a color picture tube mask according to claim 1, wherein the pressure inside the container is set to below atmospheric pressure via the vent hole. 3. The method for molding a color picture tube mask according to claim 1, wherein the filler is injected through the injection port at a pressure higher than atmospheric pressure.