JPH0474823B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for mutually positioning electrodes in a flat display device, and the present invention relates to a structure for positioning electrodes in a flat display device. The purpose is to provide a device with improved accuracy.

First, the schematic configuration of a flat display device will be briefly described. In Figure 1, 1 is a phosphor surface, 2
is a cathode, 3 is a bonding spacer, and 4 is an electrode. The electron beam emitted from the cathode 2 is horizontally and vertically deflected by various electrodes 4, and its brightness is modulated.
It reaches the phosphor surface 1 and causes it to emit light. The electrode 4 is provided with holes 16, 16' as shown in FIGS. 2 and 3, and the electron beam passes through these holes 16, 16'.
Pass through 6'. 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 because the stiffness of the electrode 5 corresponds to the stiffness of the rod 19 against simple tension and compression, whereas the stiffness of the electrode 6 corresponds to the bending rigidity of the rod 20. A long, thin shape like the rod 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 attached to both end surfaces of 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. The electrodes 5, 6 are sintered and fixed by frit glass 7 applied to the bonding spacer 3. 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. required to do so.

The electron beam travels through the window W at right angles to the plane of the paper, but the effect 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 carried out by inserting a pin into a positioning hole 10 formed in the electrode 5, 6 with high precision. The coupling spacer 3 connects each electrode 5, 6
Used to insulate and maintain and fix 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.

Next, problems related to the accuracy of positioning between electrodes that occur in such a configuration 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.

Rather than firing and fixing the electrodes all at once, it is better to divide the electrodes into units, fire and fix each of them, and then fire the units together for more precise manufacturing control. Therefore, here we will consider the accuracy defects that occur during the firing process of the unit. FIG. 6 shows a conventional example in which the electrodes 5 and 6 are fixed by firing with a bonding spacer 3. Here, 11 is the weight, 1
2 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, and 15 is a positioning pin. The electrodes 5 and 6 have a high rigidity against elongation and a low rigidity as shown in FIGS. 2 and 3.

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 cause of the position error will be explained below.

Factors that affect the elongation of the electrodes 5 and 6 include each electrode 5 and 6, the base metal 9 and insulator 8 of the bonding spacer 3, the sheets 13 and 13', and the weight 11.
The coefficient of thermal expansion and rigidity of each part of the substrate 12 and the temperature unevenness of each part can be considered, but what is essentially influential is the coefficient of thermal expansion and rigidity of the electrodes 5 and 6, the sheets 13 and 13', and the coupling spacer 3. be. The electrodes 5, using already crystallized fritted glass as the insulator 8,
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.

Considering this and looking at the heating process, the electrode 5
Because of its relatively high rigidity, it expands almost according to its own coefficient of thermal expansion, that is, the coefficient of thermal expansion of the 426 alloy, despite the constraints of the joining spacer 3 and the sheet 13'. 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 DEG C.), the coupling spacer 3 and the electrodes 5 and 6 are coupled by the frit glass 7.

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 combined, the electrode 5 expands due to 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 electrode 6 will elongate to an intermediate value between the bonding spacer 3 and the sheet 13, ie greater than the elongation of the bonding spacer 3, and will contract as the bonding spacer 3 contracts, resulting in an elongation. 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.

Therefore, an object of the present invention is to provide a flat display device that can eliminate the occurrence of positional errors caused by such differences in the amount of elongation.
Hereinafter, the present invention will be described in detail with reference to Examples.

An embodiment of the present invention is shown in FIG. In this device, an elongation adjusting spacer 14 is inserted between the electrode 6 and the sheet 13, which have low rigidity. The rest of the structure is the same as that of the conventional example shown in FIG. 6, so a description thereof will be omitted. Thermal expansion of the electrode 6, which has low rigidity, during the heating and firing process is influenced by the bonding spacer 3 sandwiching the electrode 6 and the elongation adjustment spacer 14, so that it can be adjusted by the elongation adjustment spacer 14. Therefore, the coefficient of thermal expansion of the elongation adjusting spacer 14 is set to a value such that the coefficient of thermal expansion of the electrode 6, which is less rigid, is equivalent to that of the electrode 5, which is more rigid. Further, even if the elongation adjusting spacer 14 is placed in contact with the electrode 5, a similar effect is expected. However, in this case, since the rigidity of the electrode 5 is high, the effect is small and the effect can be expected only when the electrode 5 is arranged with respect to the electrode 6, which has a low rigidity.

Further, FIG. 8 shows the results of an experiment conducted to confirm that electrode accuracy defects occur due to the above-mentioned mechanism. In this experiment, a spacer 14 for adjusting elongation having the same structure as the bonding spacer 3 shown in FIG. 4 was used. hf is the thickness of the insulator 8 shown in FIG. 4, and hm is the thickness of the base metal 9.
The coefficient of thermal expansion of the elongation adjusting spacer 14 is adjusted by the thickness of the insulator 8 (the thicker the coefficient of thermal expansion is), and the thickness of the insulator 8 is plotted on the horizontal axis (therefore, the coefficient of thermal expansion is smaller).
The larger hf/hm is, the smaller the thermal expansion coefficient is), and the vertical axis is the electrode elongation per 75 mm of electrode length after firing. Electrodes 5 and 6 indicate that the elongation adjusting spacer 14 is placed adjacent to the electrodes 5 and 6.

This result is effective for the electrode 6 having small rigidity, as described above by the mechanism. That is, the electrode elongation changes in response to a change in the coefficient of thermal expansion of the elongation adjusting spacer 14. This shows that this effect is not so great for the electrode 5 which has a large rigidity. That is, the electrode elongation does not change even if the thermal expansion coefficient of the elongation adjusting spacer 14 changes. Also,
Naturally, as the coefficient of thermal expansion of the elongation adjusting spacer 14 becomes smaller, the elongation of the electrode 6 also becomes smaller. In this case, it is shown that by setting the thickness ratio hf/hm of the insulator 8 and the base metal 9 to 1.2, it is possible to make the elongation of the electrode 6 equal to that of the electrode 5 after firing. As described above, one way to prevent the difference in electrode elongation is to make the rigidity of each electrode smaller than the rigidity of the coupling spacer 3. In this case, since each electrode has a small rigidity, its expansion and contraction during the firing process follows the expansion and contraction of the bonding spacer 3. Therefore, the difference in thermal expansion due to firing of each electrode becomes small. This means that the difference in elongation is reduced by firing can be said to be ideal.

As a method of reducing the rigidity of the electrode, there is a configuration shown in FIG. 9, for example. By providing rigidity adjusting holes 17 and 18 in addition to the hole 16 through which the electron beam passes, the rigidity can be reduced without changing the electrical characteristics of the electrode. If the electrode structure cannot be configured in this way, the expansion of the electrode can be adjusted by inserting an expansion adjustment spacer as described above. In this way, by using this method in combination,
It becomes possible to control the mutual positioning of the electrodes with high precision.

As described above, according to the present invention, by arranging the elongation adjustment spacer having an appropriate coefficient of thermal expansion adjacent to the electrode with low rigidity, the amount of elongation that occurs during firing of the frit glass of this electrode can be reduced by the amount of elongation that occurs when firing the frit glass. The structure reduces the rigidity of each electrode compared to the rigidity of the bonding spacer, eliminating the difference in elongation that occurs during firing of the frit glass. It is possible to easily perform positioning with respect to the body with high precision, and it is possible to obtain a highly effective flat display device.

[Brief explanation of drawings]

Fig. 1 is a side view showing the general configuration of a flat display device, Figs. 2 and 3 are plan views of the large and small electrodes, and Fig. 4 a and b are the coupling spacers. 5A and 5B are a sectional plan view and a side view showing the combined state of the electrodes and coupling spacers, and FIG. 6 is a diagram showing the manufacture of some units of a conventional flat display device. 7 is a side view of the manufacturing process of a flat panel display device according to an embodiment of the present invention, and FIGS. 8a and 8b are side views of the process when the electrode elongation is controlled by the elongation adjustment spacer in the same device. FIG. 9 is a plan view showing the shape of an electrode provided with a rigidity adjustment hole used in the device. 1... Fluorescent material, 2... Cathode, 3... Coupling spacer, 5... Electrode with high rigidity, 6... Electrode with low rigidity.

Claims (1)

[Claims] 1 a cathode that emits an electron beam at one end;
a phosphor that emits visible light upon collision of the electron beam at the other end; a control electrode that is located between the cathode and the phosphor and is configured of a plurality of electrodes for controlling the electron beam; A flat display device having a coupling spacer for mutually fixing electrodes and a spacer for adjusting expansion, wherein a hole for changing rigidity is provided in a predetermined electrode of the plurality of electrodes at a position where the electron beam does not pass through. A flat panel display device in which a portion is formed and the plurality of electrodes are fixed to each other by firing with frit glass applied to the coupling spacer.