JPS6182637A - Formation of thin film - Google Patents

Abstract

PURPOSE:To prevent floating of micropowder by supplying micropowder aggregation between afterward mentioned different kinds of in advance when the powder such as phophor and a different kind of powder are stuck successively to a photosensitive adhesive agent on a base plate. CONSTITUTION:When phosphor layers of green, blue and red in color are formed on the face plate of a cathode tube etc, a photosensitive adhesive agent layer 7 is formed on a base plate 6 at first and after it is exposed an exposed part 7a is given adhesiveness, on which a green luminous phosphor powder 8G is stuck. The remainder is removed by such as air blowing. A fine particle aggregation 9 consisting of particles 10 which are smaller in diameater than that of the powder 8G on the outer surfac of which fine particles 11 (20-100mmu in diameter) are stuck is subsequent supplied on it subsequently and after the remainder is removed subsequent phophor films of blue and red in color are formed. Therefore, it if possible to prevent floating of micropowder and also to reduce cohesion to a different phosphor and prevent generation of the color mixing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a thin film by rupturing powder onto a substrate.

Conventional technology One method of forming a thin film using powder is to expose a substrate on which a layer of photosensitive adhesive that develops tackiness upon exposure to light in a desired pattern, and then supply powder onto the substrate. A method is known in which a graphic powder layer is formed on a substrate by attaching powder to exposed areas that have developed tackiness and removing powder from unexposed areas. (For example, JP-A-53-1268
(No. 61) This technique is applied to the formation of a fluorescent film for a color cathode ray tube, and will be explained with reference to FIGS. 6 to 12.

In the figure, l is the face plate (substrate) of the cathode ray tube bulb, 2 is a thin film of photosensitive adhesive with a shadow line on the substrate 1, 3G, 3B, 3R [emission colors are green, blue, respectively]
It shows a red phosphor and a black light absorber. First, as shown in FIG. 6, a thin film 2 of photosensitive adhesive is formed on a substrate 1. As the photosensitive adhesive, for example, a double salt of a di7zonium compound and a metal halide salt, which absorbs moisture in the air and develops adhesiveness when exposed to light, is used, and this is mixed with a binobu such as polyvinyl alcohol, water, A mixture of 11 of IJL suitable surfactants is used.Then, as shown in FIG.
G, 2G,... are made to develop adhesiveness. Then, sprinkle green phosphor 3G over the entire surface of thin film 2.

A phosphor 3G is attached to the exposed portions 2G, 2G, . . . on the substrate 1. (Fig. 8) Then, as shown in Fig. 9, thin @
The fluorescent light 13a on the unexposed part of 2 is removed by air blowing etc.)
Removal L% exposed portion 2G, 20. - Form phosphor thin films 3G', 3G', and only on top. Next, fluorescent film 3G'
, 3G', . . . by exposing the thin @2 at a position shifted by a predetermined amount from the exposed portions 2B, 2B, .
The instep is made to have adhesive properties, and the blue-emitting phosphor 3B is attached to the substrate 1.
Spread it all over the top. (FIG. 10) Then, as shown in FIG. 11, the phosphor 3B on the unexposed portion of the thin film 2 is removed 7.
Fluorescent films 3B', 3B', . . . are formed. The steps shown in FIGS. 7 to 11 are as follows:
Repeat for R, 3R, ... and light g & leisure body 4,
As shown in FIG. 12, fluorescent films 3G/, 3B/
.

3R' and a light absorbing film 4' are formed.

When the luminescent pattern 5 is sucked in this way, the phosphor of the later formed phosphor film adheres to the previously formed phosphor film ball and is not completely removed. The remaining phosphor caused color mixture.

In order to solve such problems, for example,
Publication No. 51846 discloses that after forming one fluorescent film, before forming the next fluorescent film, a plugging powder is used between the fluorescent particles of the fluorescent film already formed on the substrate. A phosphor film has been disclosed that prevents the adhesion of unwanted phosphors by reducing or eliminating clogging tackiness.

Here, as this plugging agent, the average particle diameter is 3p or less, preferably 1μ or less. There is a disclosure that MgCO3 and the like are suitable.

However, when ultrafine powder 1, such as aluminum oxide with a particle size of 100 mμ or less, was used as a plugging agent, the plugging agent could not be successfully attached to the fluorescent film. . By the way, the particle size of cigarette smoke is 5.

~30mμ, plugging agents below loomμ are also ff! There are disadvantages in that the particles tend to float and have a low adhesion rate, and even if the particles are agglomerated and become large, they tend to float due to their small apparent specific gravity, and it takes a long time to make them adhere sufficiently.

The present invention has been proposed in view of the above-mentioned problems, and it is necessary to apply fine powder agglomerates to a substrate prior to the second and subsequent exposure steps in forming a thin film of a figure-shaped inner layer. The method is characterized in that after fine powder is supplied between the powders already attached to the substrate, the remaining fine powder aggregates are removed.

Embodiments Below, embodiments of the present invention will be explained with reference to FIGS. 1 to 5. In the figure, 6 is a substrate, 7 is a layer of Rμ luminescent adhesive formed on the substrate 6'' and which develops viscosity when exposed to light, 8 is a powder, and in this example, a fluorescent substance is shown. ,8G,8B
The luminescent colors are red and green, respectively.

Shows blue phosphor. 9 is a fine powder in which a fine powder 11 with a particle size of about 20 mμ is preliminarily deposited on the outer surface of a core particle 10 with a particle size of about 1 μm for a phosphor 8 with a particle size of about 1 to 10 μm. Shows aggregates.

First, as shown in FIG. 2, on the slope 6; a desired portion of the formed optical adhesive layer 7 (a portion 7a surrounded by a dotted line in the figure);
is exposed to light, and the exposed portion 7a is made to develop adhesiveness (first
process). Then, as shown in Figure 3, a first powder 8G (for example, a green phosphor) is supplied onto the substrate 6, spread, and attached to the exposed area f+7a (second step). Thereafter, the phosphor 8G on the unexposed portion of the substrate 7 is removed using a near plow or the like, and a W pancreas (fluorescent film) 8G' made of powder is formed on the exposed portion 7a as shown in FIG. 3rd step). After that, the process returns to the first step and the steps 1 to 31 are repeated to form a film on different powders. A fine powder agglomerate 9 is supplied on top of the 6.

This fine powder aggregate 9 is made by adhering in advance fine powder 11 having a diameter sufficiently smaller than that of the powder 8 and the core particles 10 to the outer surface of a core particle 1o having a diameter equal to or smaller than that of the powder 8. , nuclear particle 1
If the particle size of the powder 8 is 3 to 5 μm, for example, a particle size of about 1P is used as the material, and the material is preferably one that can be easily removed by washing with water, etc. If the hull is a fluorescent material, for example, λ, NaHCO3, ca.
c○3° (!aHPO4, 0a2F207, etc. can be used.

The fine powder 11 is sufficiently small compared to the diameter of the powder 8 and the core particles 10 and does not remain in the thin film and affect the operation of the thin film, for example, Al2O with a particle size of 20 to 100 mP.
3 can be used.

This fine powder aggregate 9 is a mixture of core particles 1o and fine powder 11 in a weight ratio of l'l, for example, and the outer surface of the core particle 10 is surrounded by several liters to several thousand layers of fine powder 11. , the apparent specific gravity of Al2O3 with a particle size of 20 mμ is approximately 20 g.
/ l, whereas the apparent specific gravity of this fine powder aggregate 9 is 1'! 100 to looog/e.

This fine powder aggregate 9 can be supplied to a desired portion on the substrate 6 without floating on the substrate 6J due to its apparent specific gravity.

At this time, the fine powder 11 enters between the particles of the phosphor 8 due to friction with the phosphor 8G on the exposed portion 7a. Fluorescent material 8
The fine powder 11 between the phosphors 8 crawls up between the phosphors 8 and attaches to the phosphor 8G using the adhesive, simultaneously expanding the apparent surface tag of the phosphor 8G and increasing the thickness of the adhesive. Make it thin to reduce or eliminate adhesive strength.

After this, the unnecessary part of the fine powder aggregate 9 is removed by air blowing etc.
is removed, the exposure position is shifted, and the first process is performed, and the second, third, and third phosphors 8 with different luminescent colors are processed.
Repeat each process in step y) to form a film, as shown in Figure 5.
An fN film 8' is obtained.

Effects As described above, according to the present invention, since the fine powder aggregate, in which fine powder is attached to the outer surface of the core particle in advance, is supplied onto the tracing film on the substrate prior to the second and subsequent exposure steps, Floating of fine powder is prevented, a desired amount of fine powder can be supplied to a desired position, and the adhesion of the adhesive layer formed first can be effectively reduced, and the powder layer formed later can be effectively reduced. If the powder is applied to the formation of a luminescent film using a phosphor without polymerizing the previously formed powder layer, fluorescent light without color mixture can be obtained.

fi of the drawing? Brief Explanation FIGS. 1 to 4 are partial side cross-sectional views of a substrate at each step showing an embodiment of the present invention, and FIG. 6 to 12 are partial side cross-sectional views of a substrate illustrating each step of the method for forming a thin film using a photosensitive adhesive side.

6...Substrate, 7...Photosensitive adhesive layer, 8, sR, 8G, 8B...Powder, 3'...
Thin film (powder layer), 9-? J'&Powder coagulation body, 11...The end of the costume.

No. 31 1 4C direction

Claims (1)

[Claims] After forming a layer of a photosensitive adhesive on a substrate that develops tackiness when exposed to light, a first step of exposing the photosensitive adhesive layer on the substrate to light is performed.
a second step of supplying powder onto the substrate and adhering the powder to the part that has developed tackiness due to exposure, and a third step of removing the remaining powder adhering to the substrate. at least 2
In a method of repeatedly forming a thin film, before the first step from the second time onward, fine powder aggregates are supplied between the powders already attached to the substrate, and then the remaining fine powder aggregates are removed. A method for forming a thin film characterized by: