KR20020003407A - Method cleaning Field Emittor Display using Laser - Google Patents

Abstract

PURPOSE: A method for cleaning an FED(Field Emission Display) using a laser is provided, which can achieve a simplification of a cleaning apparatus and a reduction of a cleaning cost and the reduction of a cleaning time, by performing the cleaning using a laser and a nitrogen gas. CONSTITUTION: According to the method for cleaning the FED among FED fabrication processes, the FED is transported to a cleaning space automatically. And contaminant materials attached on the FED is separated by radiating a laser onto the transported FED. Then, the FED is cleaned by jetting an inert gas to the separated contaminant material. The contaminant materials are separated from the FED because an electrostatic phenomenon is removed between the FED and the contaminant material by a laser ablation effect. The laser can a KrF excimer laser or an ArF excimer laser. Thus, the method can prevent an environmental pollution in advance, and can increase a productivity by reducing a working space because a storage vessel and an exhaustion facility for a chemical process are not required.

Description

Method for cleaning field using laser {Method cleaning Field Emittor Display using Laser}

The present invention relates to a method of cleaning a FED, which is a type of flat panel display. In particular, after performing each step in the FED manufacturing process of the FED manufacturing process, the contaminants adsorbed on the FED are removed to reduce the defective rate of the FED. By cleaning this process using a laser and nitrogen gas, the present invention relates to a FED cleaning method using a laser that can simplify cleaning equipment, reduce cleaning costs, and shorten cleaning time.

In each process of FED manufacturing, contaminants such as particles, organics, heavy metals and ionic impurities are adsorbed on the surface of the FED, and this contaminant causes FED defects. do.

The method of cleaning contaminants adsorbed on FED surface can be classified into wet and dry. Currently, dry cleaning cannot remove contaminants sufficiently. Wet cleaning is the mainstream.

In the wet cleaning, the FED is sequentially moved by a transfer robot, soaked in the chemical liquid (acid or ammonia) tank or the washing tank, and then rotated and dried.

In general, the cleaning equipment as described above is operated under demanding conditions, and the robot needs low oscillation, transfer reliability, high speed, and chemical resistance, and a high-performance motor is used for the reliability of the transfer or the high-speed transfer. Special chemical materials are also selected for double sealing with fluorine resin.

As a device for cleaning FED, it is generally used as a wet station, and it is a method of rotating the FED, spraying pure cleaning liquid and chemical liquid on the surface, and cleaning the particles with a brush. In some cases, a method of spraying pure water to remove particles may be used, or a method of oscillating high frequency ultrasonic waves to drop particles by vibrating force thereof.

Therefore, in the conventional FED cleaning method, pure water or chemicals are used to remove contaminants in the semiconductor FED. Thus, inefficient use of pure water (2,000 gallon / 200 mm 2) and chemicals are used in the process. By using the material, a large amount of VOCs (IPA, Aceton), acids (fluoric acid, sulfuric acid), solvents can be generated, and problems such as wastewater treatment can be caused, and an additional cost is incurred due to the complexity of the process. There was a problem.

Therefore, an object of the present invention is to remove the contaminants adsorbed on the FED in order to reduce the failure rate of the FED after performing each step in the FED manufacturing process of the FED manufacturing process, by cleaning the process using a laser and nitrogen gas In addition, the present invention provides a FED cleaning method using a laser that can simplify cleaning equipment, reduce cleaning costs, and shorten cleaning time.

Technical method of the present invention for achieving the above object, in the process of cleaning the FED of the FED manufacturing process, the step of automatically transferring the FED to the cleaning space; Radiating a laser onto the transferred FED to separate the contaminants adsorbed on the FED; And injecting an inert gas into the separated contaminants and discharging them to the outside for cleaning.

The present invention is a clean process that can replace chemicals, not only can eliminate the generation of chemicals and wastewater treatment mentioned in the prior art, but also a multi-stage treatment process to remove the existing pollutants as a one-step process It is possible to reduce and to prevent the pollution itself through the substances generated in the process of removing chemicals.

After the photoresist is applied to the FED or each step of developing, etching, and forming the electrode is performed, the FED is washed. As described above, the contamination adsorbed on the FED using pure water, chemicals, and brushes is conventionally performed. In contrast to the removal of the material, the present invention radiates a laser to the FED to separate the contaminants bound by static electricity on the FED, and then blows off an inert gas such as a strong nitrogen gas through the nozzle to clean it.

In addition, various wavelengths and frequencies of the laser can be used to selectively remove specific contaminants, eliminating all contaminants in one process.

When removing particles, organics, and ionic impurities adsorbed on the FED, the electronic circuits on the FED should be free of damage, and a laser wavelength suitable for the FED manufacturing process should be used.

In addition, the laser not only emits a specific part of the FED (the part where the pollutant is adsorbed), but also radiates to the entire surface of the FED to separate foreign matter bound by static electricity from the FED, and then ejects a strong nitrogen gas to the front of the FED. Discharges to the outside.

When the laser is radiated to the foreign material, the electrostatic phenomenon between the FED and the foreign material is removed by the laser ablation effect, and the foreign material is separated from the FED.

Using the laser as described above, the minimum particle size that can be removed can be up to 0.09㎛, and the cleaning time varies depending on the area of the FED, but it is possible within 15 seconds (200 sec / 200mm2) per 200mm2. It is most preferable to use the wavelength of 248nm, and depending on the pollutant to be cleaned, it is possible to use KrF Excimer laser or ArF Excimer laser, depending on the pollutant to be cleaned. have.

When FED is cleaned in the same way as above, it is possible to reduce about 70% of the washing space and to reduce about 50% of the basic working space by eliminating the need for storage tanks and plumbing facilities for chemical processes. Can be reduced.

In addition, due to the non-use of pure water and chemicals required for the existing cleaning, it is possible to produce a competitive FED in terms of cost by reducing not only production costs but also environmental purification costs such as wastewater treatment.

Therefore, in the present invention, since pure water and chemicals are not used in the cleaning process of the FED manufacturing process unlike the conventional method, it is possible to reduce the cost by eliminating the purchase cost and wastewater treatment cost of chemicals, as well as the environment due to the discharge of harmful substances. There is an effect that can prevent the source of contamination.

In addition, since the storage tank and piping equipment for the chemical process is not required, the work space can be innovatively reduced, thereby increasing the work yield in a certain space.

Claims (3)

In the process of cleaning the FED during the FED manufacturing process, which is one type of flat panel display, Automatically transferring the FED to a cleaning space; Radiating a laser onto the transferred FED to separate the contaminants adsorbed on the FED; And FED cleaning method using a laser having a step of injecting an inert gas to the separated contaminant to discharge to the outside to clean. The method of claim 1, The laser is a FED cleaning method using a laser, characterized in that using a fluorine krypton excimer (KrF Excimer) laser. The method of claim 1, The laser is an FED cleaning method using a laser, characterized in that using an argon fluoride (ArF Excimer) laser.