JP2596239B2 - Method of forming vacuum display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorescent display tube, a PDP,
The present invention relates to a method for forming a vacuum display panel having an envelope whose inside is in a high vacuum state, such as a display using an FE cathode. In particular, the present method relates to a method of forming a convex portion on the surface of a substrate which is a component of an envelope. This method includes a support member for atmospheric pressure applied to the envelope, a flat grid and an FEC. It is useful as a method for forming an electrode structure.

[0002]

2. Description of the Related Art A vacuum display panel such as a fluorescent display tube exemplified above generally has an envelope whose inside is in a high vacuum state. Atmospheric pressure is applied to the envelope, and the resulting force increases as the degree of vacuum in the envelope increases and as the area of the display unit increases. Therefore, the thickness of the glass substrate or the like, which is a constituent member of the envelope, must be sufficiently large so that the envelope is not deformed or broken. However, when the thickness of the glass substrate is increased, the envelope becomes heavier. As a means for simultaneously realizing the strength and the weight reduction, there is a case where a stand is provided between the opposing glass substrates to support the external pressure. . In this manner, a thin glass substrate can be used by providing a convex portion on the glass substrate and supporting another glass substrate facing the glass substrate from the inside.

[0003] As an example of a method of forming the above-mentioned convex portions, a method using a screen printing method is known. First, a low melting glass powder is mixed with a vehicle to form a paste, which is printed on a substrate by a screen printing method. Since the thickness of one printing is 10 to 20 μm,
It is repeated several times to form a convex pattern having a thickness of about 200 μm. Then, this is fired to blow off the vehicle components, and the low melting point glass powder is melted to form a convex screen.

[0004] Next, another method for forming the convex portion is also known. First, a photosensitive paste containing a low-melting glass powder is applied to a solid substrate and exposed through a mask. This is developed and baked to form a convex portion having a predetermined pattern.

[0005]

However, the above-mentioned conventional method has the following problems. According to the first method, the pattern formed by the screen printing method is misaligned, the printing accuracy is not very high, and it is difficult to form a fine convex pattern. Further, the glass powder melted at the time of firing may flow to cause deformation of the pattern (referred to as sagging). According to the second method using a photosensitive paste, there is a problem that the film thickness to be formed is small, and a high convex portion having an aspect ratio (height / base length) of 1 or more is formed with high precision. It was difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of easily forming a projection having a large aspect ratio on a substrate without deformation of a pattern.

[0007]

According to a method of forming a vacuum display panel according to the present invention, a step of applying a photosensitive paste containing a low melting point glass powder on a substrate, and a step of applying a predetermined pattern to the substrate in a predetermined pattern. Forming a convex part of a predetermined pattern made of low-melting glass by developing after exposure, filling a concave part on the substrate with a filler, baking the substrate, and removing the filler And a step of performing

According to a second aspect of the present invention, there is provided a method of forming a vacuum display panel, comprising: applying a photosensitive paste containing a low-melting glass powder onto a substrate; Forming a convex portion of a predetermined pattern made of low-melting glass, and filling a recess in the substrate with a filler to form a single layer of the convex portion of the low-melting glass and the filler. Laminating one or more monolayers on the monolayer with an insoluble deposition layer interposed therebetween, firing the substrate, and removing the filler.

[0009]

The convex portion of the low-melting glass paste formed on the substrate is protected by the filler filled in the concave portion between the convex portions, so that it is not deformed even if it is baked and melted. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1A, a photosensitive paste 2 is applied to the upper surface of a substrate 1 by a screen printing method. The thickness can be about 70 to 200 μm with one squeegee.
The substrate 1 is made of a heat-resistant substance such as glass, ceramic, or silicon. The photosensitive paste 2 contains about 80 parts of a low-melting glass powder and about 20 parts of a UV-curable photosensitive vehicle as main components. others,
If a filler is to be mixed, or if it is desired to have conductivity, a metal powder or the like is mixed.

As shown in FIG. 1B, the substrate 1 is passed through a photomask 3 on which a predetermined pattern is formed.
The photosensitive paste 2 is irradiated with ultraviolet rays. As shown by hatching in the figure, the portion irradiated with the ultraviolet rays hardens.

The substrate 1 is developed with water, and uncured portions are removed as shown in FIG. 1C to form convex portions 4 having a predetermined pattern. A portion of the substrate 1 where the convex portion 4 is not formed becomes a concave portion 5 which is relatively dented with respect to the convex portion 4.

The filler 6 may be any substance that does not melt at a temperature of 400 to 600 ° C., for example, NaCl, K ₂ SO
30 parts of a water-soluble inorganic solid powder such as ₄ are dispersed in 70 parts of a methyl ethyl ketone solvent to form a slurry.
This is applied on the concave portion 5 and the convex portion 4 of the substrate 1 by a spray method. This is dried to evaporate the solvent, and as shown in FIG. Then, firing is performed in a furnace in an oxidizing atmosphere at 400 to 600 ° C. in a state where the filler 6 is filled in the concave portion 5.

In the firing step, the low-melting-point glass powder forming the projections 4 is melted, and the organic components contained in the filler 6 are decomposed and evaporated. The projection 4 is melted, but the projection 4
Since the filler 6 filled in the concave portion 5 between the convex portion 4 and the convex portion 4 serves to support the shape of the convex portion 4, the shape of the convex portion 4 is not deformed in the firing step. Therefore, if the substrate 1 is cooled after firing, the protrusions 4 made of low melting point glass powder are used.
Are fixed in a shape corresponding to the pattern of the photomask 3 with high precision.

Then, the cooled substrate 1 is spray-washed with water to remove the filler 6 in the recess 5. As a result, as shown in FIG. 1 (e), the projections 4 having a high-precision pattern without deformation during firing are formed on the substrate 1.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. A convex portion 4 is formed on a substrate 1 and a concave portion 5 is formed.
1 (a) to 1 (d) in FIG.
Are the same as those of the first embodiment, and the description thereof is omitted.

After the drying step shown in FIG.
In order to make the height of the protrusions 4 equal to that of the protrusions 4, an extra filler 6 is scraped off with a squeegee, and the surfaces of the fillers 6 and the protrusions 4 are made substantially the same flat surface as shown in FIG. . in this way,
In this embodiment, the layer of the protrusions 4 and the filler 6 formed on the substrate 1 is referred to as a single layer 7.

Since the flat surface of the single layer 7 is not a plane with high precision, the deposition layer 8 is formed on the flat surface before the next step.
Is formed to smooth the surface. That is, as shown in FIG. 2 (b), an acrylic resin, which is a resin insoluble in water as a developing solution, is applied to the surface of the single layer 7 by spraying to form an applied layer 8.

Next, as shown in FIG. 2C, the photosensitive paste 2 is applied again on the deposition layer 8, exposed through a photomask 3, developed with water, and filled with a filler. 6 and dried, and the excess filler 6 is scraped off.
These series of steps are shown in FIGS. 1 (a), (b), (c),
Each of the steps of the first embodiment shown in FIG. 2D and the scraping step of the second embodiment shown in FIG. 2A are continuously performed, and the detailed description thereof is as described above. Therefore, it is omitted. Then, as a result, the single layer 7
And another single layer 7 is formed by laminating the layers. Both single layers 7,7
Since the adhered layer 8 that is insoluble in water as a developing solution is separated, the filler 6 of the lower monolayer 7 is washed away by the water used for forming the upper monolayer 7. Never.

The formation of the single layer 7 and the deposition layer 8 described above are alternately performed, and a plurality of single layers 7 are laminated so as to have a desired height as shown in FIG.

Next, this is fired in an oxidizing atmosphere at 400 to 600 ° C. to decompose and evaporate the organic solvent contained in each single layer 7 and the above-mentioned deposited layer 8. In this case, FIG.
As shown in FIG. 7, the low-melting glass of each single layer 7 is melted to form an integral convex portion 9. At this time, since each projection 9 is supported by being surrounded by the filler 6, a highly accurate pattern is realized without deformation. Since the vehicle in the low melting point glass flies and the adhered layer 8 is decomposed, the projection 9 of the low melting point glass is relatively lower than the filler 6.

Next, after the adhesion layer 8 that is not soluble in water is decomposed in the baking step, if the substrate 1 is washed with water, the filler 6 can be dissolved and removed.

Next, a third embodiment of the present invention will be described. First, a water-soluble filler is spray-coated on a substrate and dried, and the above-mentioned deposition layer is formed thereon as an undercoat layer. Then, the projections of the first or second embodiment described above are formed thereon. Finally, when the filler is washed and removed with water, the undercoat layer and the projections thereon are separated from the substrate, so that independent projections not adhered to the substrate are obtained.

Next, a fourth embodiment of the present invention will be described. As in the second embodiment described above, the single layers are stacked in the same pattern using the same photomask, and if a single layer formed by a photomask having a different pattern is interposed somewhere in the middle, A projection having a hole or a slit can be formed. For example, if a single layer formed in another pattern is stacked on top of a plurality of single layers stacked in a predetermined pattern and then baked, a slit 1 is formed in the upper part as illustrated in FIG.
1 can be formed. Further, if a single layer formed in another pattern is interposed in the middle of a plurality of single layers laminated in a predetermined pattern, a convex portion 14 having a hole 13 can be formed as shown in FIG.

The projections 4, 9, 1 of each embodiment described above.
The members 2 and 14 can be used as members for supporting the atmospheric pressure applied to the envelope by being interposed between the substrates constituting the envelope of the vacuum display panel. In particular, the projections 12 and 14 of the fourth embodiment shown in FIGS. 3 and 4 are provided inside the envelope, and even when the interior is partitioned, the respective partitions communicate through the holes 13 or the slits 11. There is no hindrance to the evacuation work in the enclosure.

The application of the projection formed by the method of the present invention is not limited to a support member in a vacuum display panel. In addition, the present invention can be used to form a three-dimensional structural member such as a planar grid having a horizontally extending structure provided in a certain kind of fluorescent light emitting tube or an electrode structure of a field emission device. In order to form such a hybrid electrode structure by this method, the conductive powder may be mixed in the single-layer low-melting glass powder at a required specific position among the single layers to be laminated. Although a water-soluble substance is used as the filler in this embodiment, an insoluble filler may be used. In such a case, the filler can be removed by a physical method.

[0027]

According to the present invention, the sintering is performed in a state where the filler is filled between the projections, so that the low melting point glass powder constituting the projection is melted in a mold made of the filler, cooled, and fixed. Will do. Therefore, deformation such as sagging does not occur on the convex portion, and a pattern with high accuracy can be formed.

By laminating a single layer, it is possible to form a high-accuracy convex portion having a high aspect ratio of 10 or more without deformation such as sagging.

Since the photolithography method of forming a pattern by exposing the photosensitive paste through a mask is applied, the accuracy of the pattern of the projections is high.

If the projections manufactured in a separate step are assembled to the substrate, the accuracy and time required for the alignment between the projections and the substrate become problematic. However, in the present invention, the projections and the substrate are placed at desired positions on the substrate. Since the protrusions can be formed integrally, the alignment between the substrate and the protrusions can be omitted, and the process can be simplified.

[Brief description of the drawings]

FIG. 1 (a), (b), (c), (d), (e)
FIG. 3 is a process chart of the first embodiment of the present invention.

FIG. 2 (a), (b), (c), (d), (e)
FIG. 4 is a process chart of a second embodiment of the present invention.

FIG. 3 is a schematic view showing an example of a projection formed in a fourth embodiment of the present invention.

FIG. 4 is a schematic view showing another example of the protrusion formed in the fourth embodiment of the present invention.

[Explanation of symbols]

1 ... substrate, 4, 9, 12, 14 ... convex part, 5 ... concave part, 6 ...
Filler, 7: single layer, 8: adhered layer.

Claims (2)

(57) [Claims] 1. A step of applying a photosensitive paste containing a low-melting glass powder on a substrate, and a step of forming a convex portion having a predetermined pattern made of low-melting glass by exposing the substrate to a predetermined pattern and developing the substrate. A method of filling a recess in the substrate with a filler, a step of firing the substrate, and a step of removing the filler. 2. A step of applying a photosensitive paste containing a low-melting glass powder on a substrate, and a step of forming a convex portion having a predetermined pattern made of a low-melting glass by exposing the substrate to a predetermined pattern and developing the substrate. And filling a filler in the concave portion on the substrate to form a single layer composed of the convex portion of the low-melting glass and the filler, and forming the single layer with an insoluble deposition layer therebetween. A method for forming a vacuum display panel, comprising: laminating one or more single layers thereon; baking the substrate; and removing the filler.