JPS5920834A - Method for evaluating and observing powder - Google Patents

Abstract

PURPOSE:To evaluate and observe cohesive sample powder under the state of primary particles, by dropping a composite body, which is obtained by sufficiently dispersing and stirring the sample in a liquid with an ultrasonic wave, on a tape adhesing surface on a mounter, and blowing a highly pressurized gas on the composite body. CONSTITUTION:A liquid, by which sample powder 3 is not chemically or physically changed, is prepared in a breaker and the like, and the sample powder 3 is put in the liquid. The inside of the beaker is stirred by an ultrasonic wave washing device, and the sample powder 3 is dispersed. Meanwhile, a piece of tape 2 is held on a sample mounter 1. A suitable amount of the sample powder 3 and the liquid is dropped on the adhesing surface of the tape with a spoon and the like. Compressed air of about 2kg/cm<2> is made to blow on the tape, and the liquid on the tape surface and the sample powder, which is not stuck to the tape surface, are blown away. Before cohesion, the sample body 3 is strongly held on the surface of the tape 2 under the state close to only one layer as primary particles. The mounter 1 is placed in a coating device, and the surface of the powder is coated. Thereafter, evaluation and observation are performed.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a powder evaluation and observation method, and more specifically, when evaluating and observing a cohesive powder by SEM, the powder sample is firstly It relates to a method of dispersing particles and holding them on a sample mounter.

[Technical background of the invention and its problems]

Conventionally, various powders have been evaluated and observed using various simple methods such as microscopic observation using a microscope or an electron W1 microscope. On the other hand, in recent years, simple scanning electron microscopes (SIFMs) have been used at many manufacturing sites and in trial production due to their improved performance and ease of handling. The following method was generally used to observe the sample powder using the S antode.

That is, as shown in FIG. Sprinkle powder 3 with a spoon or some other method and attach it to the adhesive tape.
was held in hand to adhere the surface of the tape 20 to the surface of the powder to be observed. The powder was held on the 11 tape.

When sample powder is observed by SEM using such a conventional method,
The sample powder was observed to overlap in the side layer, making it impossible to observe the exact shape, surface condition, etc. of the primary particles.

Furthermore, if the powder content of the sample is 78%, it is not possible to properly evaluate and observe the powder unless it is dispersed in the secondary particles of the intestinal powder collection. b.
The l' value was observed.

In the conventional method, not all the sample powder adheres to the adhesive tape surface, and the powder in the upper layer, which overlaps the side layers, tends to scatter from the sample surface, which causes SEi during SEM observation. There were many small particles that scattered into the 'v1 equipment and caused malfunctions of the SEM equipment.

[Purpose of the invention]

The present invention improves the shortcomings of the above-mentioned conventional method for testing and observing powders, especially cohesive powders, in SEM, and the sample powder is thoroughly collected using ultrasonic waves in a liquid that does not alter the properties of the sample powder. Before the dispersed cohesive powder re-agglomerates by the action of the liquid, the sample powder is stretched over the tape in almost a single layer, so that the secret sample powder An object of the present invention is to provide a powder evaluation/observation method that allows the observation of the sample powder in the state of primary and one standup particles, and also prevents the sample powder from scattering into the SEM device, which may cause failure of the SEM device. purpose.

[Summary of the invention]

Holding of the sample powder to be observed on a mounter according to the present invention is carried out as follows. That is, a liquid-filled beaker or the like in which the sample powder is not dissolved or subjected to chemical or physical changes is prepared in advance, and the sample powder is placed therein.

Next, the beaker containing the sample powder and liquid is thoroughly stirred using an ultrasonic cleaner to disperse the sample powder.

Before or after this, double-sided tape or conductive tape, etc., is attached on the SEM sample mounter in advance.
This tape should be in close contact with the mounter, and the adhesive surface for holding the sample powder should also be exposed. The adhesive surface of the tape on the mounter prepared in this way was thoroughly washed with an ultrasonic 21V washing machine, and then the sample powder, which had been thoroughly stirred, was applied with a liquid using a small spoon. You l) r practice 1” stir. Next, approximately 2 kg/kg of liquid and sample powder were dropped onto the adhesive surface of the tape.
Quickly blow clean word 4 with a pressure of d.

By doing this, the liquid on the tape 111 and the sample powder that has not been adhered to the tape surface are scattered at this point. In addition, the sample powder is strongly held on the tape surface in a state close to only an overlying layer of primary particles before re-agglomerating.

Next, the mounter holding the sampled powder was placed in a coater cracker, and the fine surface of the powder was coated under predetermined conditions, and then inspected with SEL'vt to a value of 11.1'.

-゛The liquid used in the composite of the method of the present invention may be any liquid as long as it does not alter the quality of the sample powder. Examples of high viscosity liquids include ethylene glycol, η-pucnol, isopucnol, etc., and volatile liquids include ethyl alcohol. It is preferable to use call accommodation.

〔Effect of the invention〕

The present invention is particularly effective for SEM observation and evaluation of cohesive powder. That is, by firmly adhering the coagulated solids to the tape on the mounter in a state where they are dispersed in primary particles, it is possible to prevent the sample powder from scattering into the SEM equipment, and the S of the powder can be prevented.
It greatly contributes to evaluation and observation by EM.

[Embodiments of the invention]

Examples will be explained below.

Example-1 A goethite (FesO+) sintered body was crushed using a hand crusher, and the powder having an average particle diameter of 2.0 μm was measured using a mesh sieve using a plain method.

This powder exhibits cohesiveness as it is pulverized, and when the sum is 41 or less, the 0 agglomeration is noticeable. Therefore, in order to observe a pulverized powder of 2 .mu.m by SEM, a step is required to convert the powder into a primary particle state.

Using ethylene glycol, which has a viscosity of 25.1 at room temperature (20°C), put an appropriate amount of the sample powder into a beaker filled with this liquid, place the beaker together in an ultrasonic cleaning vessel, and use a spoon etc. to thoroughly wash the powder. It was dispersed and spread.

Separately, add a few drops of the viscous liquid containing the sample powder onto the adhesive surface of the tape on the mounter prepared in advance, and quickly apply it to about ZKV! blown clean air. The rigidly attached mounter of this sample paddy was coated with a coater device and evaluated and observed using SEM. (Fig. 2) Comparative Example-1 The sample powder was a sintered body of Geitai (Fe, 04), which was crushed by a hand crusher, passed through a mesh sieve,
The average particle size measured by the Blaine method (3.0μ) was used.

Using this conventional method, sample powder was coated on the tape surface of the mounter with nine coats of coke and observed using SIM. When observed at a magnification of 500 times, the powder is piled up in many layers over the entire surface, making it impossible to observe its shape and average particles.

Example 2 On the other hand, as a result of observing the same sample powder prepared by the method of the present invention using ethyl alcohol as the liquid in Comparative Example 2, it was found that, as in Example 1, most of the particles were in one layer. The average particle can be observed accurately, and by increasing the magnification as necessary, it is possible to obtain a large amount of data.

Further, there was no scattering of the sample powder into the SEM soy sauce.

In the present invention, the claimed scope is a sample for SEM, but for example,
It can also be applied to sample powder for microscopic observation, etc.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the adhesion resistance of sample powder on a mounter according to the conventional method, and FIG. 2 is a perspective view showing the adhesion resistance of sample powder on the mounter according to the method of the present invention. (11, W patent attorney close aide Kensuke (and 1 other person) No. 1 No. 2 219- /3 Do2 l /3 ~2 l

Claims (2)

[Claims] (1) A process of ultrasonically dispersing and stirring a composite consisting of a sample powder and a liquid that does not alter the sample powder, and dropping the composite onto a sample mount for a scanning electron microscope having an adhesive surface. A method for evaluating and observing powder, comprising the steps of: and spraying high-pressure gas gold onto the dropped composite. (2) A method for evaluating and observing a powder according to claim 1, characterized in that the liquid in the composite has high viscosity or volatility.