Vacuum particle counter

Abstract

The invention relates to a vacuum micro-particle counter which comprises a shell; the shell is provided with a measuring hole penetrating through the shell in the z direction, and the interior of the shell is fixedly provided with light incident parts, light detection parts and a light emitting part; the light incident parts are used for emitting laser and forming a flat-topped light beam with the cross section light intensity evenly distributed, are located on one side of a measuring hole, and each comprise a laser device, an incident optical element set and an incident diaphragm which are sequentially arranged in the x direction; incident optical element groups each comprise a focusing lens, a light homogenizing rod and a lens group which are sequentially arranged along the x direction; the light detection parts collect scattered light formed by scattering the flat-topped light beam by the micro-particles and detect the number of the micro-particles on the basis of the collected scattered light; and the light emitting part and the light incident parts are oppositely positioned on the other side of the measuring hole, and the light emitting part is used for absorbing the part, which is not scattered by the micro-particles, in the laser emitted by the light incident parts. According to the vacuum micro-particle counter, the special incident light path comprising the light homogenizing rod is adopted, so that incident laser forms a flat-topped light beam with uniformly distributed cross section light intensity, and an effective measurement area can be increased.

Description

technical field [0001] The invention relates to the field of dust-free processing and manufacturing and vacuum technology, and more particularly relates to a vacuum particle counter. Background technique [0002] Dust-free manufacturing has strict cleanliness requirements for the processing environment. For example, cleanliness level 10 requires that the number of particles larger than 0.1 microns in the environment is less than 10,000 per cubic meter. In some applications, such as high-energy particle accelerators , Chip manufacturing in the semiconductor industry, and thin-film panel production and assembly in the photovoltaic and display industries also involve a vacuum environment, so there are also dust-free requirements for the entire vacuum process involved in manufacturing and processing. Air-borne particle counters are generally used to monitor the number of particles of different sizes in the atmospheric environment. The principle is to collect the air in the envir...

AI Technical Summary

Problems solved by technology

[0003] However, in a vacuum environment, especially in a high vacuum, gas molecules move in the form of a molecular flow, and the direction of their movement is random, resulting in the movement of particles in the environment without uniform directionality, so it is difficult to monitor particles, and There are currently no particle counters designed for use in vacuum

The problem with the detection unit in the currently used air-borne particle counter is that the measurement area is small, generally less than 10 5 On the order of cubic microns, the probability of detecting randomly moving particles in a high vacuum environment is very small, which cannot be used for particle monitoring in a vacuum environment

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