JPS63112442A - Panel cleaning method for color picture tube - Google Patents

Abstract

PURPOSE:To completely remove sticking dust on the inner surface of a panel and efficiently obtain the titled smooth panel without correction, by cleaning the inner surface of the titled heat-treated panel with a brush using a cleaning solution, primarily washing the inner surface with water, subjecting the inner surface to acid cleaning treatment and carrying out the secondary washing with water. CONSTITUTION:The inner surface of the titled panel prepared by combining a panel without forming a fluorescent surface with a shadow mask and heat- treating the combined panel in a high temperature environment is physically brushed with a soft material, e.g. nylon brush, gauze, etc., for 10-15sec while supplying a cleaning solution to clean and remove sticking materials firmly sticking to the inner surface of the panel without damaging the panel. The inner surface thereof is primarily washed with water. The panel washed with water is then sprayed with a 10-18% hydrofluoric acid solution e.g. under 1-1.5kg/cm<2> pressure for about 15-30sec, to carry out acid cleaning treatment. The panel is secondarily washed with high-pressure pure water under, e.g. about 5kg/cm<2> pressure, coated with a resist, dried and sent to an exposing and printing process.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for cleaning a color picture tube panel.

(Conventional technology) In recent years, the screens of color picture tubes have become increasingly finer.
As represented by medium- and high-definition display tubes, the smallest screen has more than 5 million pieces (14 inch 0.20u
It is composed of picture elements (m-bit circular hole mask type).

Therefore, in the work of forming a phosphor screen corresponding to an almost infinite number of picture elements, various difficulties are encountered in order to obtain a screen without defects.

Conventional black matrix type fluorescent screen and black matrix 1. In the process of forming a phosphor screen such as a drive-type phosphor screen, as shown in Figure 2, a panel that has been processed in a high-temperature environment, for example, in a furnace at 450°C, is first washed with water for about 15 seconds in step 10, and then immediately washed with acid. In washing step 11, hydrofluoric acid (HF concentration 10~
18%), nitric acid (HNO3 concentration 5 to 10%), or a mixture thereof for 30 seconds to 1 minute, and then water washing is performed again for about 30-1 minutes in water washing step 12, and then resist coating step 13 After the resist is applied in step 1, the film is sent to the next step, an exposure and baking step, through a drying step 14.

(Problem to be solved by the invention) However, in the conventional manufacturing method, when the panel and the mask are combined and passed through a furnace at about 450°C to be thermally stabilized, some particles adhere to the mask. Dust and dust adhering to the inner wall of the panel, as well as heavy metals such as iron powder in the furnace, oil scum, PVC debris, etc., firmly adhere to the inner surface of the panel due to the high heat.
Since these deposits are not completely removed during the water washing process, there is a problem in that the deposits cause uneven etching during the pickling process.

For example, as shown in Fig. 3(a), there is dust on one side of the panel.
If the etching process is performed in the pickling process while the dust is still firmly attached, the area to which the dust has adhered will be exposed to hydrofluoric acid compared to the area without dust, that is, the normal area, as shown in Figure 3(b). Since the etching progresses slowly, the dust-attached portion remains as a convex portion 3, and the smoothness of the inner surface of the panel 1 is impaired.

Therefore, when a resist film of 0.5 μm or less is formed after cleaning, the coating cannot be uniformly applied, and eventually minute defects occur in the resist film.

When the size of the dust that causes this resist film defect was investigated, it was found that most of the particles were about 20 μm or larger.

As an example, in a 14-inch 0.31mm pitch black matrix phosphor screen, the number of defects per panel is 2 to 2.
Three occurred. Normally, this defect is repaired by a person who corrects the inspection process, but since such a defect is minute, inspection work is difficult.

Attempts have been made to completely remove deposits on the inner surface of the panel by repeating water washing, pickling, one pickling, and one water washing in the above steps, but no complete solution has been reached.

In addition, after the pickling process, brushing was performed to remove dust, but since the pickling process was completed, the areas where the dust was present were not pickled and remained in a convex shape, which caused the panel surface to deteriorate. No improvement in flatness was achieved.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for cleaning a color picture tube panel, which completely removes dust adhering to the inner surface of the panel and improves the flatness of the panel plane.

[Structure of the Invention (Means for Solving Problems)] The color picture tube panel cleaning method of the present invention includes a heat treatment process in which a panel on which no phosphor screen is formed and a shadow mask are combined and heat treated in a high temperature environment. a cleaning process in which the inner surface of the heat-treated panel is brushed with a soft material while supplying a cleaning solution to remove deposits on the inner surface of the panel without damaging the panel; and a first step in which the brushed panel is washed with water. It is characterized by having a water washing step, a pickling step of carrying out a pickling treatment on the washed panel, and a second washing step of washing the pickled panel with water.

(Function) The present invention can completely remove metal oxide powder and other dust adhering to the inner surface of the panel by performing a physical cleaning process.

(Example) An example of the method of the present invention will be described below with reference to FIG.

The color picture tube panel cleaning method of this example is roughly divided into a physical cleaning method and a chemical cleaning method.The panel selected for the black matrix or black stripe forming process is first physically cleaned by a detergent brushing process 20 to remove nylon. Physically brush with L-92 (trade name: 0.2% solution of Proronic surfactant) for about 10 to 15 seconds with a brush or gauze, then wash with water for about 1 hour in step 21.
After washing with water for 5 seconds, in the pickling step 22, it is washed with a hydrofluoric acid (10-18%) solution for about 15-30 seconds at 1-1.5K.
Spray at g/cj pressure.

After performing high-pressure water washing at 5y/ci7 pressure in a final pure water washing step 23, a resist is applied in a resist coating step 24, followed by a drying step 25 and then sent to the next exposure and baking step. When a panel was actually treated using this color picture tube panel cleaning method, the number of defects per panel (14 inch 0.3 inch pitch) was zero. Furthermore, when 100 panels of this type were cleaned, 80%
I was able to get more than one uncensored panel.

[Effects of the Invention] As explained above, according to the color picture tube panel cleaning method of the present invention, dust adhering to the inner surface of the panel can be completely removed, so that the inner surface of the panel becomes smooth and an unmodified panel can be cleaned. Obtainable.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the method of the present invention, Fig. 2 shows a conventional method, and Fig. 3 shows deposits in the pickling process in the conventional method! It is a diagram showing the 5th Symphony. 1... Panel 2... Deposit 3... Convex portion 20... Detergent brushing step 21.・
......Water washing step 22...Pickling step 23...Pure water washing step 24...Resist coating step 25・・・・・・
...Drying process applicant Toshiba Corporation agent Patent attorney Sasu Suyama - Figure 1

Claims (1)

[Claims] (1) A heat treatment process in which a panel on which no phosphor screen is formed and a shadow mask are combined and heat-treated in a high-temperature environment, and the inner surface of the heat-treated panel is brushed with a soft material while supplying a cleaning liquid. a cleaning step of removing deposits on the inner surface without damaging the panel; a first washing step of washing the brushed panel with water; and a pickling step of treating the washed panel with pickling;
A method for cleaning a color picture tube panel, comprising: a second washing step of washing the pickled panel with water.