JP2009233482A - Method of cleaning particle by atmospheric-pressure plasma - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for removing, cleaning and recovering efficiently contaminated particles. <P>SOLUTION: A contaminated particle-rare gas stream is introduced into an atmospheric-pressure plasma space through nozzles 2a and 2b having an angle to electrodes 1a and 1b, and collided with insulators 5a and 5b installed between the electrodes or between the electrode and the nozzle to remove contaminated materials from the particle 6 surfaces, or to collide particles in an aggregational state of secondary particles and convert them into a primary particle state and remove and clean the contaminated materials of the particle surfaces. The contaminated materials of the particle surfaces are again removed and cleaned with the atmospheric-pressure plasma by the rare gas stream from the nozzle installed in the rear to improve the cleaning effects, and to efficiently recover the particles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of cleaning contaminant particles with atmospheric pressure plasma.

  With the sandblasting technology, particles such as sand can be made into a high-speed jet state to cut the material surface. This technique can perform not only cutting processing but also adhesion processing by selecting an appropriate particle size and substrate. Particles that recoil without being attached in such processing collide with the substrate and are contaminated on the surface. In this way, the particles are not only contaminated but also contaminated with substances and molecules by various pretreatments. By applying a high electric field between parallel electrodes having a minute gap under atmospheric pressure, a plasma in a glow discharge state (ionization state) is generated between the electrodes, so that the surface of the substance in the vicinity of the electrode can be adsorbed without damage. Inorganic deposits and the like can be cleaned.

JP 2005-101539 A JP 2007-84908 A

  An apparatus for applying a particle jet fluid to the surface of a material by applying a sandblasting technique and cutting it has been commercialized. A technique for performing adhesion processing by appropriately selecting the particle diameter, substrate material conditions, jet state, and the like has also been developed. In the case of cutting, particles are disposable because very inexpensive particles such as alumina and silicon oxide are used. In the case of adhesion processing, in the conventional method of using disposable functional particles because expensive functional particles are used, the technology has a problem that the superiority is extremely lowered when an element or the like is manufactured. In the case of fine particles, since the surface is activated, unnecessary molecules are often adsorbed on the surface of the fine particles, which has a problem that the characteristics of the fine particles are deteriorated. At the time of processing, since the particles once contact with the substrate, they are contaminated and cannot be reused as they are, and they cannot be used if the contaminants are already adsorbed on the particles before use. The particles have a problem that it is easy to form secondary particles, and even if the particles are cleaned as they are, the inside of the secondary particles cannot be cleaned, and the cleaning efficiency is poor. Also, there is a problem that the recovery rate is low even if it is cleaned and reused as it is.

  A particle flow is generated by using a gas flow, and the particle flow is introduced into a space in an atmospheric pressure plasma state to be cleaned, and the particle contamination is removed and reused. At that time, the secondary particles are dissolved by the kinetic energy of the gas-particle flow to become primary particles, which enables efficient cleaning. In addition, the gas-particle flow injected through the nozzle is caused to collide obliquely with the electrode, and the atmospheric pressure plasma generated at the nozzle and the electrode installed obliquely behind is passed again to be cleaned again. It is possible to increase. Furthermore, since the gas-particle flow and the gas flow are jetted in an oblique direction, the jet drifts in one direction, so that a method that enables efficient clean particle recovery is provided.

  Even if it is processed using expensive particles, it can be efficiently recovered and recovered, so that it can be reused. Therefore, the system of the present invention can improve the productivity of a device manufacturing method using jet particles.

  Cleans contaminated particles generated during sandblasting and powder jet deposition (PJD).

The entire apparatus for carrying out the method of the present invention is shown in FIG.
A voltage of 1.2 kHz and 1 kV is applied to the electrodes 1a and 1b, the distance between the nozzles 2a and 2b and the insulators 5a and 5b is set to 3 mm, and helium is used to make Fe3O4 particles 2a and 2b at a pressure of 150 kPa. Particles were cleaned by flowing from a nozzle.

  The FT-IR spectrum of Fe3O4 particles (particle size 200 nm to 500 nm) contaminated with oleic acid and the FT-IR spectrum of Fe3O4 particles cleaned using the apparatus of FIG. 1 were measured. As shown, the CH2 mode and COOH mode spectra disappeared, indicating a cleansing effect.

  Cutting devices using micro-scale particle jets have already been commercialized. On the other hand, adhesion processing equipment using micro / nanoscale particle jets is in the development stage. In the adhesion processing, expensive particles are frequently used and there is no method for cleaning the collected particles, which is a big problem in commercializing the adhesion processing apparatus. The provision of the apparatus of the present invention not only improves the profitability of processing by a cutting apparatus that has been commercialized, but also makes it possible to achieve profitability even with expensive particles even when using an apparatus for adhesion processing. Therefore, there is a very high possibility that it will be commercialized as a manufacturing apparatus for electronic components. In addition, since the particle surface on which the contaminants adhere to the particle surface can be efficiently cleaned, the electronic component is sensitive to the contaminants and may be used for cleaning the particles for production.

It is a general view of an apparatus. It is a figure which shows the cleaning effect.

Explanation of symbols

1a, 1b Electrodes 2a, 2b Nozzle 3 Glow discharge generated by gas flow 4 Glow discharge generated by gas and particle flow 5a, 5b Insulator 6 Particle 7 Clean particle stock box

Claims (4)

  Particles are introduced into the atmospheric pressure plasma space while flowing gas from the nozzle, and contaminants on the particle surface are removed by collision with an electrode or an insulator placed between the electrode and the nozzle, or the secondary particle aggregation state is solved 1 A method of removing / cleaning contaminants adhering to the particle surface by plasma in consideration of at least one of the methods of making the next particle state.   A method of using a single gas or a mixed gas of argon, helium, and xenon, which are noble gases, in order to avoid compound formation in addition to air, oxygen, and nitrogen as a gas for cleaning by the method according to claim 1.   3. The condition according to claim 1, wherein one or two or more gas injection nozzles are formed such that particles and gas are injected obliquely at an angle between the nozzle and the electrode, and an angle is formed behind the resulting jet. A method to increase the effect of atmospheric pressure plasma cleaning and to make it easier to collect.   In the conditions of claims 1 and 2, the gas of claim 2 is allowed to flow between the nozzle and the electrode without affecting the cleaning with the atmospheric pressure plasma generated between the nozzle and the electrode, and the cleaned particles can be easily recovered. how to.

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