KR20020000193A - Method cleaning Electronic Parts and PCB using Laser and HCl Annealing - Google Patents

Abstract

PURPOSE: A method for cleaning an electronic device and a substrate using a laser and a HCl annealing is provided to simplify a cleaning equipment, reduce a cleaning cost and shorten a cleaning time. CONSTITUTION: Electronic devices and substrates are automatically transferred to a cleaning space. In the transferred electronic devices and substrates, metals and Natrium/chemical oxide are annealed in mixed atmosphere that is formed by mixing HCl, H2 gas with NO and N2 so as to form metallic pollutants into metal organics. Pollutants like a micro-contamination, such as particles, organic matters and ionic impurities adsorbed on the electronic devices and substrates are separated by emitting a laser. An inert gas is sprayed to the separated pollutants so as to discharge the pollutants to the outside and remove the pollutants. A vacuum chamber in which the laser is operated and a vacuum chamber in which a HCl annealing is available are commonly used. The laser is a KrF Excimer laser. Otherwise, the laser may be an ArF Excimer laser.

Description

Method for Cleaning Electronic Parts and PCB Using Laser and HC Annealing

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning electronic components and substrates, and in particular, contaminants adsorbed on electronic components and substrates in order to reduce defect rates of electronic components and substrates after each process in the manufacturing process of electronic components and PCB substrates. This process is performed by mixing the cleaning gas with an inert gas and heat-treating in a dilute gas atmosphere to remove metal contaminants into metal organics, and to remove the laser and nitrogen gas. The present invention relates to a method for cleaning electronic components and substrates using laser and HCl annealing, which can achieve cleaning by using the same, thereby simplifying the cleaning equipment, reducing the cleaning cost, and shortening the cleaning time.

In the process of manufacturing electronic components and substrates, contaminants such as particles, organic substances, heavy metals and ionic impurities, oxide films, and metals are adsorbed on the surface of electronic components and substrates in the process of manufacturing electronic components and substrates. Due to this, defects of electronic components and substrates are generated. Therefore, contaminants should be removed after each process.

Methods of cleaning contaminants adsorbed on the surface of electronic components and substrates can be largely classified into wet and dry. Currently, dry cleaning cannot remove enough contaminants. Wet cleaning to remove material is the mainstream.

In the wet cleaning, the transfer robot moves the electronic components and the substrates sequentially, soaks the electronic components and the substrates in a chemical solution (acid or ammonia) tank or a washing tank, and then rotates the electronic components and the substrates to dry them.

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.

Equipment for cleaning electronic components and substrates is generally used as a wet station, which is a method of rotating electronic components and substrates, spraying pure cleaning liquid onto the surface, and cleaning particles with a brush. In some cases, by spraying pure water at high pressure to remove the particles, or by oscillating high-frequency ultrasonic wave may be used to drop the particles by the vibration force.

Therefore, the conventional electronic parts and substrates cleaning method as described above uses pure water or chemicals to remove contaminants in the electronic parts and substrates. By using gallon / 100mm2) or chemicals, 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. There was a problem that a lot of incidental costs occur.

Accordingly, an object of the present invention is to remove contaminants adsorbed on electronic components and substrates in order to reduce the defective rate of the electronic components and substrates after each process in the electronic components and substrates processing process of the electronic components and substrates manufacturing process. This process is performed by mixing the cleaning gas with an inert gas and heat-treating in a dilute gas atmosphere to remove metal contaminants into metal organics, and using laser and nitrogen gas. The present invention provides a method of cleaning electronic components and substrates using laser and HCl annealing, which 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 electronic components and substrates of the electronic component and substrates manufacturing process, the step of automatically transferring the electronic components and substrates to the cleaning space; Removing the metal contaminants into metal organics by mixing cleaning gas and inert gas with the transferred electronic parts and substrates and heat-treating them in a mixed gas atmosphere having a reduced concentration; Radiating a laser to separate contaminants adsorbed on electronic components and substrates; And injecting an inert gas into the separated contaminants and discharging them to the outside for cleaning.

The present invention is a dry process that can completely replace the wet cleaning process, it is possible to drastically reduce the use of the generation of chemicals and waste water treatment mentioned in the prior art, as well as to implement a multi-stage treatment process for removing contaminants. It can be reduced to a one-step process, minimizing contamination through materials generated in the process of removing chemicals.

After the photoresist is applied to the electronic components and the substrates or the development, etching, and electrode formation are performed, the electronic components and the substrates are cleaned. As described above, pure water, chemicals, and brushes are conventionally used. While the contaminants adsorbed to the electronic parts and the substrates are removed by using the present invention, the present invention provides a method for treating metal contaminants by mixing the cleaning gas and the inert gas to the electronic parts and the substrates, and then performing heat treatment in a mixed gas atmosphere having a diminished concentration. First cleaning and metal lasers are used to clean and remove the pollutants combined with electrostatic components by discharging the laser on the electronic parts and substrates, and inert gas such as strong nitrogen gas is ejected through the nozzle. In the process of manufacturing electronic parts and substrates, the second cleaning process is performed in one process. It will remove all the contaminants that occur.

In addition, the laser's various wavelengths and frequencies can be used to selectively

It can be removed so that all the contaminants can be removed in one process.

Particles, organics and ionic impurities adsorbed on electronic components and substrates are cleaned using a laser. Heavy metals and oxides (Natrium / Chemical Oxide) are NO, By heat treatment in a mixed gas atmosphere where N₂ and the like are mixed, metal contaminants are made into metal organics and removed.

In order to remove contaminants through this cleaning, there should be no damage to electronic components and electronic circuits on the PCB, and cleaning gases and laser wavelengths suitable for electronic components and substrates processes should be used.

In addition, heat treatment in a mixed gas atmosphere where NO and N2 are mixed with HCl and H₂ gas is diluted, and the heat treatment is not only in contact with a specific part of the electronic component and the substrate, but in contact with the entire surface of the electronic component and the substrate. And the atomic bonding portion of the oxide film and the metals on the surface of the substrates are made of metal organics, and the laser is radiated to the entire surface of the electronic components and the substrates to separate foreign matter bound by the static electricity from the electronic components and the substrates, and then the strong nitrogen. The gas is ejected to the entire surface of the electronic component and the substrate to discharge foreign substances to the outside.

When the laser is emitted to the foreign matter, the laser ablation effect removes the electrostatic phenomena between the electronic component, the substrate, and the foreign matter, and the foreign matter is separated from the surface of the electronic component and the PCB.

By using HCl annealing and laser as described above, the minimum particle size that can be removed can be up to 0.09㎛, and the cleaning time can be within 25 seconds per 200mm2 (25sec / 200mm2). It is most preferable to use 248nm, and the wavelength of laser is 248nm. HCl, HF / H₂O or HF / alcohol is used as the cleaning liquid, and fluoride krypton exemer (KrF Excimer) is used depending on the pollutant to be cleaned. Lasers can be used or ArF fluoride (ArF Excimer) lasers can be used.

By cleaning electronic components and substrates in the same way as above, it is possible to drastically reduce the size of storage tanks and plumbing equipment for chemical processes, which can reduce about 50% of the cleaning space and about 50% of the basic working space. It can also reduce the number of workspaces innovatively.

In addition, due to the use of the minimum amount of pure water and chemicals required for the existing cleaning, it is possible to produce electronic components and PCBs that are competitive in cost by reducing production costs as well as environmental purification costs such as wastewater treatment.

Therefore, in the present invention, as well as using a minimum amount of pure water and chemicals in the cleaning process in the manufacturing process of electronic components and substrates, it is possible to reduce the cost of reducing the purchase cost and wastewater treatment cost of chemicals Minimal discharge of harmful substances has the effect of minimizing the cost of environmental pollution.

In addition, the storage tank and plumbing equipment for the chemical process can be reduced to innovatively reduce the work space has the effect of increasing the work output in a certain space.

In addition, the success of the dry cleaning process in the electronic component and substrate manufacturing process can achieve a 100% dry process of the electronic component and substrate manufacturing process.

Claims (4)

In the process of cleaning electronic components and substrates during the manufacturing process of electronic components and substrates, Automatically transferring the electronic components and substrates to a cleaning space; Making heavy metals and oxide films to the transferred electronic components and substrates by heat-treating them in a mixed gas atmosphere by diluting NO, N 2, etc., with HCl and H 2 gas to dilute the metal contaminants into metal organics; Radiating a laser to separate contaminants such as micro-contamination such as particles, organics, and ionic impurities adsorbed on the electronic components and substrates; And injecting an inert gas to the separated contaminants and discharging them to the outside to clean the electronic parts and substrates using a laser and HCl annealing. The method of claim 1, A method of cleaning electronic components and substrates using a laser and HCl annealing, wherein the vacuum chamber in which the laser operates and the vacuum chamber capable of HCl annealing are used in common. The method of claim 1, The laser is a cleaning method for electronic components and substrates using a laser and HCl annealing, characterized in that using a fluorine krypton excimer (KrF Excimer) laser. The method of claim 1, The laser is a cleaning method for electronic components and substrates using a laser and HCl annealing, characterized in that using an argon fluoride (ArF Excimer) laser.