KR20020000197A - Method cleaning Electronic Parts and PCB using Laser and Vapor Phase - Google Patents

Abstract

PURPOSE: A method for cleaning an electronic device and a substrate using a laser and a vapor phase 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. Metals and Natrium/Chemical oxide are removed from the transferred electronic devices and substrates by spraying HCl, HF/H2O or HF/alcohol in a vapor-phase gas state, whereby surfaces of the electronic devices and substrates are finely etched, so as to separate pollutants. The pollutants are discharged to the outside by using a vacuum pump. 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 a laser is operated and a vacuum chamber in which the cleaning solution can be sprayed in the vapor-phase gas state 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 PCBs Using Laser and Vapor Phase

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. By using the cleaning liquid gas and laser and nitrogen gas which vaporized the process, the laser and gas phase can be used to simplify the cleaning equipment, reduce the cleaning cost, and shorten the time required for cleaning. A method for cleaning electronic components and substrates.

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 the electronic components and the substrate chips may be removed, and contaminants should be removed after each process.

As a method of cleaning contaminants adsorbed on the surface of electronic parts and substrates, they can be classified into wet and dry. Currently, dry cleaning cannot remove enough contaminants. Wet cleaning to remove 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 performing each step in the processing process of the electronic components and substrates during the manufacturing process of the electronic components and substrates. This process is performed by using vaporized cleaning liquid gas, laser and nitrogen gas to clean the process, reducing the cleaning equipment cost, and reducing the time required for cleaning. The present invention provides a method for cleaning components and substrates.

Technical method of the present invention for achieving the above object, in the process of cleaning the electronic components and substrates during the manufacturing and processing process of the electronic components and substrates, the step of automatically transferring the electronic components and substrates to the cleaning space Wow; Spraying and etching gaseous cleaning liquid gas onto the transferred electronic components and substrates; Discharging the crushed contaminants to the outside through a vacuum pump; 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 present invention removes contaminants adsorbed on electronic parts and substrates by using the present invention, the present invention emits a first cleaning and a laser to etch electronic parts and substrates by using gaseous cleaning liquid gas on the electronic parts and substrates. Process to separate the contaminants combined due to static electricity on electronic components and substrates, and then in the process of secondary cleaning in which inert gas such as strong nitrogen gas is blown out through the nozzle and cleaned. This will remove all contaminants from the bed.

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

Particles, organics and ionic impurities adsorbed on electronic components and substrates are cleaned using a laser, and heavy metals and oxides (Natrium / Chemical Oxide) are HCl, HF / H₂O or HF. It is cleaned by fine etching the surface of electronic parts and substrates in the gaseous gaseous state of / alcohol.

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

In addition, the vaporized cleaning gas is not sprayed only to specific parts of electronic parts and substrates, but is sprayed on the entire surface of the electronic parts and substrates to scrape off the atomic bonding portions of oxide films and metals on the surfaces of the electronic parts and substrates, and After radiating the entire surface of the electronic components and substrates to separate the foreign matter coupled by the static electricity from the electronic components and the substrates, a strong nitrogen gas is ejected to the front of the electronic components and substrates to discharge the 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.

Using the cleaning liquid gas and the 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 (200 sec / 200mm2) per 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 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; Separating heavy metals and oxides into the vaporized gas state of HCl, HF / H 2 O, or HF / alcohol in the transferred electronic parts and substrates to finely etch surfaces of the electronic parts and substrates to separate contaminants; And discharging contaminants to the outside using a vacuum pump. 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 into the separated contaminants and discharging them to the outside to clean the electronic parts and substrates using a laser and a gaseous phase. The method of claim 1, And a vacuum chamber in which the laser is operated and a vacuum chamber capable of spraying the vaporized gas state of the cleaning liquid are used in common. The method of claim 1, The laser is a cleaning method for electronic components and substrates using a laser and gas phase, characterized in that using a fluorine krypton excimer (KrF Excimer) laser. The method of claim 1, The laser is an argon fluoride (ArF Excimer) laser, characterized in that the laser and gaseous phase electronic components and substrates cleaning method.