JPS62112711A - Method for producing and recovering ultrafine particle - Google Patents

Abstract

PURPOSE:To easily produce and recover ultrafine particles by sticking the ultrafine evaporating particles formed by heating and evaporating the raw material to be made into the ultrafine particles in a vacuum vessel to a cooling body such as ice then taking out the cooling body and thawing the same. CONSTITUTION:A refrigerant such as freon is circulated into a metallic substrate 7 through an inlet 8 and an outlet 9 in the vacuum vessel 1 to cool the substrate and to form a cooling body layer 10 of ice or dryice, etc. on the substrate surface. After the inside of the vacuum vessel 1 is evacuated through a discharge hole to a vacuum, a material 5 such as Ni for the ultrafine particles in a crucible 3 is heated to evaporate by a electron gun 4. The ultrafine particle-like Ni vapor 6 deposits successively on the cooling body layer 10 such as ice or dryice on the substrate 7 surface to form the ultrafine particle layer 11 of Ni. Such layer is taken out of the vacuum vessel 1 and the ice or dryice is thawn or sublimated by which the ultrafine particles of Ni are recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing ultrafine particles, and particularly to a method for easily collecting and recovering ultrafine particles that have been heated and evaporated in a vacuum.

(Prior art) A conventional method for collecting and collecting fine particles generated by vacuum evaporation is to cool and condense the evaporated particles in an inert gas atmosphere, turn them into fine particles, and allow them to fall naturally into an evaporation container. There is a method of collecting the particles, or a method of installing a collection substrate facing the flow of evaporated particles, depositing the evaporated particles on the collection substrate, and then mechanically peeling off the deposited particles on the collection substrate. In the case of the former, there are many problems such as the need for subsequent powdering treatment, the possibility of contamination with impurities on the substrate or the powdering process, and the difficulty in making the particle manufacturing process continuous. It is necessary to install a mechanism to efficiently collect particles in a vacuum chamber, and this method tends to be impractical as a particle recovery method in a limited space.

(Problems to be Solved by the Invention) The present invention seeks to provide a method for collecting and collecting fine particles that can overcome the problems of conventional methods in collecting generated fine particles.

(Means for Solving the Problems) The present invention heats and evaporates a raw material for ultrafine particles in a vacuum, and deposits the evaporated ultrafine particles on a substrate made of a cooled solidified substance that easily melts and sublimates. This is a method for producing and recovering ultrafine particles, which is characterized by collecting ultrafine particles by depositing them on a substrate and then heating the substrate to melt or sublimate them.

Hereinafter, specific means of the present invention will be explained in detail with reference to FIG.

In FIG. 1, 1 is a vacuum chamber, 2 is an exhaust hole, 5 is a crucible, 4 is an electron gun, 5 is an evaporation material, 6 is a vapor flow, 7 is a recovery board, 8 is a refrigerant inlet, 9 is a refrigerant outlet, 10 is an ice (or dry ice) layer, and 11 is an ultrafine particle layer.

An evaporation material 5 to be used as an ultrafine particle raw material is placed in a crucible 5 in a vacuum chamber 1 kept in vacuum by an exhaust hole 2, and an electron gun 4 is placed in the crucible 5.
A recovery substrate 7 that is cooled by a refrigerant is installed at a position facing the vapor flow 6, and a recovery substrate 7 that is cooled by a refrigerant is placed on the recovery substrate 7. A layer 10 of a substance that sublimates, for example ice, or a substance that sublimates easily, for example dry ice, is formed.

Therefore, the vapor flow 6 is deposited one after another on the ice or dry ice layer 10 to form an ultrafine particle layer 11.

When the deposition of the ultrafine particle layer 11 is completed, the recovery substrate 7 on which the ultrafine particle layer 11 is deposited is taken out from the vacuum chamber 1 via the ice or dry ice layer 10, and the ice or dry ice layer 10 is melted or sublimated. Therefore, the ultrafine particles are separated from the collection substrate 7 and collected.

By collecting ultrafine particles using such a method, it is possible to reduce the possibility that impurities from the collection substrate will be mixed in during the collection process.

In addition, by continuously moving the collection substrate, the production and collection of ultrafine particles can be made continuous.
Its industrial value is extremely large.

Hereinafter, the present invention will be further explained in detail by giving specific examples of the present invention.

Example 1: Production and Recovery of N1 Fine Particles [ was heated and evaporated by an electron beam heating method (SXW electron beam) under a vacuum degree of 10"wmHg,
An ice substrate cooled to -10'0 was placed opposite the flow of Ni evaporated particles. The method for installing the ice substrate is to cool the water on the surface of the steel recovery substrate with a Freon refrigerant and freeze it at -10'oC in a vacuum evaporation chamber before reducing the pressure to 10' trrm Hg. , and then subjected to depressurization treatment.

After performing evaporation deposition treatment on the surface of the water storage plate for 10 minutes under these conditions, the substrate was recovered from the vacuum chamber, and the ice was melted.
Ni fine particles were collected. The average particle size of the produced fine particles is (
〇Example 2: μ60. Production and recovery of fine particles: Evaporate the fine particles from the mul, 0. substrate using the mul ion sputtering method under the vacuum degree of 10'' ym Hg, and evaporate the mul, 0. fine particles by facing the evaporation flow to -90'. A dry ice substrate cooled to 0 was installed.The method of installing the dry ice substrate was as in the previous example, with the interior of the vacuum chamber 10''
! Before reducing the pressure to 1w]lltg, the surface of the steel recovery substrate was cooled to 90'O with an ammonia gas refrigerant to generate a dry ice substrate, and then the pressure was reduced to perform sputtering of mul*os. The test was carried out for 20 minutes. After the treatment, the substrate is recovered, the dry ice is removed by vaporization, and the substrate is shim l, 0. Fine particles were collected. A/, O, the average particle size of the fine particles was α1μ.

As described in detail above, the present invention is a highly practical method for producing ultrafine particles by vacuum evaporation, and has significant industrial value.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram for explaining the present invention. Sub-agent: 1) Akira Sub-agent Ryo Hagi Hara - Sub-agent Atsuo Yasunishi Engraving of drawings (no changes to content) Figure 1 February-3, 1986

Claims (1)

[Claims] The raw material for ultrafine particles is heated and evaporated in a vacuum, the evaporated ultrafine particles are deposited on a substrate made of a cooled solidified substance that easily melts and sublimates, and then the substrate is heated to melt or sublimate. A method for producing and recovering ultrafine particles, characterized by collecting ultrafine particles using