KR960011848B1 - Braun tube panel watching method - Google Patents

Abstract

For assembling a CRT consisting of a panel, a funnel and an electron gun, the method washes the CRT panel in the steps of : jet-spraying deionized water on the panel loaded on the washing machine; executing an idler process on the panel cleaned with floric acid to repeat the process at least twice and wash the panel again with pure water for finishing. The idler process turns the panel to evenly apply the washing water over the panel face and remove sufficiently the remaining floric acid from the whole inner face.

Description

CRT panel cleaning method

The present invention relates to a CRT panel cleaning method.

The CRT is largely composed of a panel portion, a funnel portion connected to it, and an electron gun, and is manufactured from a panel portion processing step in manufacturing.

Phosphor slurry to be emitted by electrons should be formed inside the panel. To facilitate the slurry coating, contaminants such as glass foreign substances and oil, and a panel cleaning process for washing are performed.

The cleaning begins by loading the panels into the cleaning apparatus, which usually goes through a series of repeated cleaning processes.

That is, loading, washing, hydrofluoric acid washing, washing, hydrofluoric acid washing, hydrofluoric acid washing, washing, washing, etc. are performed. After the first hydrofluoric acid, the concentration of the next hydrofluoric acid solution is lowered by the pure water remaining inside the panel. In addition, there was a problem that excessive use of the hydrofluoric acid solution was caused by several times the washing of the hydrofluoric acid.

Accordingly, an object of the present invention is to provide a CRT panel cleaning method capable of effectively cleaning CRT panel without using excessive hydrofluoric acid solution.

In order to achieve the above object, the present invention provides a method of spraying pure water on a panel loaded in a cleaning apparatus, a step 2 of performing an idle process after washing the panel with a hydrofluoric acid solution, and performing the step 2 at least twice. In this case, step 3 is to perform pure washing.

Next, the process of this invention is demonstrated in detail.

Regarding the cleaning of the CRT panel, the surface of the glass panel must be cleanly cleaned with hydrofluoric acid and pure water before applying the fluorescent film to the inner surface of the panel, that is, the inner surface of the glass panel. It is for decreasing the simple adhesive force.

If there is a glass component or other contaminants on the inner surface of the glass panel, the adhesion between the phosphor surrounded by silicic acid and the silica in the glass panel component is weakened in the precipitation process, resulting in a drop in the fluorescent film.

The cleaning solution used in this important cleaning process is pure water and hydrofluoric acid solution. The nature of the solvent is determined by dielectric constant, acid-base property, self dissociation, etc.

The prepared panel is loaded into a washing apparatus and washed first with deionied water to give the inner surface of the panel a wet surface so that the inner surface can be evenly washed.

Subsequently, the hydrofluoric acid (HF) solution is sprayed first to perform hydrofluoric acid washing.

The dielectric constant of the solvent is that the molecules are polarized due to the difference in electronegativity of each atom. The hydrofluoric acid solution is a very good solvent over a wide range of both inorganic and organic compounds.

The hydrofluoric acid has a self dissociation property, acts as a strong acid in an aqueous solution, and dissolves glass, so that the SiO ₂ component of the glass bulb becomes Si-OH and binds to the phosphor.

After the hydrofluoric acid washing step (idle) to have a process section.

In this case, the idling process rotates the panel so that the remaining hydrofluoric acid (HF) solution is sufficiently washed evenly over the entire inner surface of the panel.

After the idle process, the second hydrofluoric acid washing process is performed again, and the concentration of the hydrofluoric acid washing solution is maintained by performing the idle operation without using pure water by the idle section, thereby increasing the washing effect.

After the second hydrofluoric acid washing and having an idle process again, a second pure washing process is performed to finish the panel cleaning work.

As described above, the present invention does not excessively use the hydrofluoric acid solution by performing the idle process, thereby reducing the manufacturing process cost in the mass production process, and also washing the pure water by not diluting the concentration of the hydrofluoric acid solution. The work becomes clear.

In addition, there is an effect of recycling pure water.

Claims (1)

In the cleaning method of the CRT panel, the step of injecting pure water to the panel loaded in the cleaning device and the step 2 of performing an idle process after washing the panel with a hydrofluoric acid solution, and performing the step 2 at least two times, the pure water washing CRT panel cleaning method, characterized in that consisting of a step 3.