KR20110058063A - Optical absorption type paticle measurement apparatus - Google Patents

Abstract

PURPOSE: A light absorption type particle measurement apparatus is provided to measure the size and number of particles in the whole sections along the path of collimated light beams that pass through a measurement chamber. CONSTITUTION: A light absorption type particle measurement apparatus, which measures the distribution of particles moving in a measurement chamber(C) from the amount of light absorbed by the particles, comprises a light generating unit(200) and a light detecting unit(300). The light generating unit generates collimated light beams that pass through the measurement chamber parallely. The light detecting unit receives and detects the light beams passing through the measurement chamber.

Description

Optical Absorption Type Paticle Measurement Apparatus

The present invention relates to a light absorption type particle measuring device. More specifically, by generating parallel light from the light generating unit and receiving the light in the light detecting unit, the size and number of particles can be measured in all sections along the path of parallel light passing through the inside of the measuring chamber. The measurement area is expanded to provide more accurate measurement results and at the same time equipped with a reflecting mirror to change the path of parallel light, the size and number of particles are measured in the most optimized state according to the measurement environment. The present invention relates to a light absorption type particle measurement device further improved reliability.

In general, nano-level high precision processes such as semiconductor processes and LCD processes can lead to fatal product defects if contaminants are generated in the work facility. Therefore, in a clean facility such as a clean room, a high level of cleanliness can be maintained. The process is underway and real-time monitoring of contaminated particles is also very strict at these facilities.

Therefore, in such a facility, a separate particle measuring device for measuring polluted particles in the facility is used, and the particle distribution state of a specific chamber in the facility is measured in real time through the particle measuring device.

Such a particle measuring device measures the distribution state of particles in an arbitrary measurement chamber, that is, the size and number of particles, and the like to measure the distribution state of air pollutant particles in addition to the clean room equipment or to measure the distribution state of specific particles in a laboratory or the like. It is widely used in a variety of fields, such as used for.

The type of particle measuring device is classified into various types according to the size of the particle or the measuring method. The particle measuring device for measuring nano-level particles is generally classified into light scattering and light absorption by light. do.

The light scattering method detects scattered light generated by collision with particles flowing in the space inside the measuring chamber after incident light into the measuring chamber and determines the size and number of particles. It is a method of determining the size and number of particles by detecting the amount of light absorbed by the particles flowing in the measurement chamber after entering the light, the two types of particle measuring device is selectively used widely according to the needs of the user.

In detail, the principle of the light absorption type particle measuring apparatus is generally investigated by irradiating light to form a focal point in the measurement chamber in the light generating unit, and receiving and detecting light passing through the focus area in the light detecting unit. In this case, the light generated by the light generator is absorbed and extinguished by the particles flowing in the measurement chamber and is received by the light detector. Therefore, the particle size is measured by comparing the intensity of the light generated by the light generator with the intensity of the light detected by the light detector and calculating the result by a separate controller. At this time, the method of calculating the particle size by using the measured light intensity is possible through Mie theory which examines the relationship between the particle size and the light intensity. In addition, the light absorption type particle measuring apparatus also measures the number of contaminant particles present in the measurement chamber by measuring the number of changes in the intensity of light detected by the light detection unit.

As described above, in the light absorption type particle measuring apparatus which measures the size and number of particles, the diameter of light should be smaller than the diameter of the particle to be measured according to Mie theory. You can get it. In other words, an accurate measurement value can be obtained only for particles having a size larger than the diameter of light irradiated to the measurement chamber. According to this principle, a general light absorption type particle measuring apparatus according to the prior art is configured by irradiating light having one focal point in the light generating unit as described above in order to reduce the diameter of light.

However, when irradiating light having one focal point in the light generating unit as described above, in order to substantially measure the size of the nano-level particles, it is possible only in an area adjacent to the focal point of light. Because accurate measurements can be obtained only in the range where the diameter of the light becomes smaller than the diameter of the particle to be measured, such measurement is possible only near the focal region where the diameter of the light is reduced to the nano level. Therefore, the conventional light absorption particle measuring apparatus according to the prior art can only measure the size and number of particles limited to the particles present in the vicinity of the focal region in the measurement chamber. Since the size and number cannot be measured, there is a problem that the accuracy and reliability of the measured values are deteriorated.

The present invention is invented to solve the problems of the prior art, an object of the present invention is to generate parallel light from the light generating unit to be received by the light detection unit, so that in all sections along the path of parallel light passing through the inside of the measurement chamber Since the size and number of particles can be measured, an area for measuring particles in the measurement chamber is expanded to provide a light absorption type particle measuring apparatus that provides more accurate measurement results.

Another object of the present invention is to increase the intensity of light by forming a parallel diameter of a small diameter through a plurality of focusing lens and parallel light lens to enhance the light intensity, the light absorption which can more accurately measure the amount of light absorbed and destroyed by the particles An anticorrosive particle measuring apparatus is provided.

Another object of the present invention is to adjust the diameter of the parallel light formed through the parallel light lens module with a beam expander, not only to measure the particle of a specific size range, but also to adjust the diameter of the parallel light to repeat the measurement Accordingly, the present invention provides a light absorption type particle measuring device capable of grasping the particle distribution state by classifying each particle present in the measurement chamber by its size.

Another object of the present invention is to measure the light absorption type particle which can remove noise and reduce the overall scale of the device by limiting the parallel light received by the light detector through the interference filter and the absorption filter and reducing the amount of light. To provide a device.

Another object of the present invention is to mount a reflection mirror to change the path of parallel light, by measuring the size and number of particles in the most optimized state according to the measurement environment, the light absorption type particles further improve the reliability of the measurement results It is to provide a measuring device.

The present invention provides a light absorption type particle measuring apparatus for detecting an amount of light absorbed and extinguished by particles, and measuring a distribution state of particles flowing in a measurement chamber, wherein the light generation generates light to pass through the measurement chamber. part; And a light detector for receiving and detecting light passing through the measurement chamber, wherein the light generated by the light generator is parallel light passing through the measurement chamber in parallel. to provide.

In this case, the light generating unit includes a laser diode for generating laser light; And it may be configured to include a parallel light lens module for converting the laser light generated through the laser diode into parallel light.

In this case, the parallel light lens module comprises a plurality of focusing lenses for focusing the laser light to one focal point; And a plurality of parallel light lenses for converting the laser light passing through the focal point into parallel light.

The light generating unit may further include a beam expander configured to expand or reduce the diameter of the parallel light converted through the parallel light lens module.

In addition, the light detector may include at least one of an interference filter for removing light in a specific wavelength region and an absorption filter for reducing the amount of light.

The light absorbing particle measuring apparatus may further include at least one reflective mirror reflecting parallel light so that a path of parallel light passing through the measuring chamber may be changed.

In addition, it may be configured to further include an actuator that can adjust the reflection angle of the reflection mirror.

In addition, the light detector may be installed to be movable relative to the measurement chamber to receive the parallel light in response to the path change of the parallel light by the reflection mirror.

According to the present invention, since the parallel light is generated from the light generating unit and received by the light detecting unit, the size and number of particles can be measured in all sections along the path of the parallel light passing through the inside of the measuring chamber. The area in which particles can be measured is extended to provide more accurate measurement results.

In addition, by forming a parallel light with a small diameter through a plurality of focusing lenses and parallel light lenses to enhance the light intensity, there is an effect that can more accurately measure the amount of light absorbed and extinguished by the particles.

In addition, by adjusting the diameter of the parallel light formed through the parallel light lens module with a beam expander, not only the particle of a specific size range is measured, but also the measurement is repeated by adjusting the diameter of the parallel light. Particles can be classified according to their size to determine the distribution of particles.

In addition, by limiting the parallel light received by the light detector through the interference filter and the absorption filter and reducing the amount of light, noise can be eliminated and the overall scale of the device can be reduced.

In addition, by mounting a reflection mirror to change the path of parallel light, there is an effect that can further improve the reliability of the measurement results by measuring the size and number of particles in the most optimized state according to the measurement environment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a perspective view showing a schematic shape of a light absorbing particle measuring apparatus according to an embodiment of the present invention, Figure 2 conceptually illustrates the internal structure of the light absorbing particle measuring apparatus according to an embodiment of the present invention 1 is a cross-sectional view taken along the line “AA” of FIG. 1, and FIG. 3 is a conceptual diagram illustrating an enlarged conceptual view of a structure of a light generating unit of a light absorption type particle measuring apparatus according to an exemplary embodiment. 5 is a conceptual diagram conceptually illustrating an operating state of a reflection mirror of the light absorption type particle measuring apparatus according to the exemplary embodiment of the present invention.

The light absorption type particle measuring apparatus according to an embodiment of the present invention measures the amount of light absorbed and extinguished by particles flowing in the measurement chamber C, and thus the distribution state of the particles present in the measurement chamber C, That is, a device for measuring the size and number of particles and the like, and includes a light generating unit 200 and a light detecting unit 300 mounted in communication with the measurement chamber (C). At this time, the measurement chamber (C) may be applied to a wide variety of devices, such as a clean room equipment that is a facility of the semiconductor process or LCD process or a separate case for measuring the air pollution degree or various experimental devices used in the laboratory.

The light generator 200 is a device that generates light to pass through the measurement chamber C. The light generator 200 generates light through a laser diode 210 that generates laser light, and generates laser light through the laser diode 210. It is configured to convert to parallel light through a parallel light lens module 220 to be described later.

The light detector 300 is an apparatus for receiving and detecting light generated from the light generator 200 and passing through the measurement chamber C. The light detector 300 includes a light receiving sensor 310 for receiving light. The sensor 310 is connected to a separate control unit 400 so that the light received by the light receiving sensor 310 is configured to be converted into an electrical signal and transmitted to the control unit 400.

At this time, the size of the particles present in the measurement chamber (C) is calculated through the intensity of the light received by the light detector 300. That is, the intensity of the light generated by the light generator 200 and the intensity of the light received by the light detector 300 are compared. Measure the size of. In addition, the number of particles is measured by measuring the number of occurrences of changes in intensity of light of a predetermined size or more. Since the principle of the light absorption type particle measuring device is a known technique, detailed description thereof will be omitted.

In the light absorption type particle measuring apparatus configured and operated as described above, light generated by the light generator 200 is generated as parallel light L passing through the measurement chamber C in parallel according to an embodiment of the present invention. It is configured to be. This parallel light (L) is possible through the parallel light lens module 220 according to an embodiment of the present invention. That is, in general, the laser light generated by the laser diode 210 is generated having a range of emission angles. Thus, the laser light having the emission angle is configured to operate the parallel light lens module 220 according to an embodiment of the present invention. Passes through and is converted into parallel light (L). At this time, the diameter of the parallel light (L) is preferably configured to be adjusted through a separate beam expander 230, the details thereof will be described later.

The parallel light lens module 220 is possible through various lens combinations that can be converted into parallel light (L), the parallel light lens module 220 according to an embodiment of the present invention is a laser as shown in FIG. And a plurality of focusing lenses 221 for focusing light at one focal point F and a plurality of parallel light lenses 222 for converting laser light passing through the focal point F into parallel light L. Can be.

In more detail, the laser light having a constant emission angle from the laser diode 210 passes through a plurality of focusing lenses 221 disposed a certain distance back along the direction of light travel from the laser diode 210. Focused to focus on the focal point (F) region of. Thereafter, the laser light passing through the focal point F is extended and progressed at the same angle as when the light is focused back to the focal point F. In order to convert the laser light, which is extended in this way, into parallel light L, a plurality of parallel light lenses 222 are disposed at a rear of the predetermined distance along the traveling direction of the light from the focal point F region. Therefore, the laser light passing through the focal point F area is converted into parallel light L through the parallel light lens 222 after being extended to some extent after passing through the focal point F area. In this case, the distance from the focus F area to the parallel light lens 222 is preferably smaller than the distance from the focus F area to the focusing lens 221, and thus, through the parallel light lens 222. The converted parallel light L is concentrated in a smaller area than the state before being focused through the focusing lens 221, and thus the intensity thereof is further enhanced.

According to the configuration of the parallel light lens module 220, the laser light generated by the laser diode 210 is concentrated to a smaller diameter and converted into parallel light L, whereby the intensity of the parallel light L is The amount of light that is enhanced and absorbed and dissipated by the particles in the measurement chamber C can be measured more precisely.

According to the structure of the light absorption type particle measuring apparatus according to an embodiment of the present invention, the light generated from the light generating unit 200 passes through the measuring chamber (C) in the form of parallel light (L) light detection unit ( Since it is received at 300), it is possible to measure the amount of light absorbed and extinguished by the particles in a relatively wider area, thereby obtaining a more accurate measurement result. That is, in the conventional light absorption type particle measuring apparatus according to the prior art, since the light focused from the light generating unit is generated, the distribution state of the particles can be limitedly measured only in the region adjacent to the focal point where the diameter of the light becomes smaller than the diameter of the particle. On the other hand, in the light absorption type particle measuring apparatus according to an embodiment of the present invention, since parallel light L is generated from the light generating unit and passes through the inside of the measurement chamber C, parallel light L passes. The distribution of particles in all regions can be measured along the path. Therefore, since the distribution state of the particles can be measured in a wider area than in the prior art, a more accurate measurement result can be obtained for the distribution state (size and number of particles, etc.) of the particles flowing inside the measurement chamber (C). Can be.

In addition, in the light generating unit 200 according to the exemplary embodiment of the present invention, as described above, the beam expander 230 is disposed in the rear of the parallel light lens module 220 along the traveling direction of the light. 230, the diameter of the parallel light L may be adjusted to expand or contract. Since the beam expander 230 corresponds to a known technique as a device for expanding or decreasing the diameter of light, detailed description thereof will be omitted.

By the beam expander 230 as described above, the light absorption type particle measuring apparatus according to the exemplary embodiment of the present invention is adjusted to suit the particle size range to be measured by adjusting the diameter of the parallel light L according to the use condition. Can be adjusted. That is, in the case where it is desired to measure only relatively large particles existing in the measurement chamber C, the diameter of the parallel light L is adjusted relatively large by adjusting the beam expander 230, and the particles exist in the measurement chamber C. If only small particles are to be measured, the diameter of the parallel light L may be relatively small by adjusting the beam expander 230. Therefore, if the beam expander 230 is measured a plurality of times while adjusting, the size of particles present in the measurement chamber (C) can be identified by classification.

On the other hand, since the light absorption type particle measuring apparatus according to an embodiment of the present invention measures the distribution state of the particles using the parallel light L as described above, the particle distribution state in the relatively large measurement chamber (C) It is easy to measure. Accordingly, the size and number of particles directly mounted on the outer wall of the clean room 10 used in the semiconductor or LCD process may be easily measured. However, in addition to measuring the size and number of particles connected to the pipe 11 of the clean room 10 and flows along the pipe 11 of the clean room 10 according to an embodiment of the present invention.

In this case, the light absorbing particle measuring apparatus further includes a case 100 communicating with the pipe 11 according to one embodiment of the present invention, as shown in FIGS. 1 and 2, and on the outer wall of the case 100. The light generator 200 and the light detector 300 may be positioned. In a facility such as the clean room 10, a flow of fluid occurs in a certain direction according to the characteristics of the facility, so that particles in the measurement chamber C flow in a constant direction according to the flow of the fluid. It is preferably formed in a hollow shape to have a predetermined length along the flow direction of the communication chamber (C) to form the same measurement chamber (C), the light generating unit 200 and the light on the outer wall of the case 100 The detector 300 may be mounted to be positioned on the same straight line. In this case, the light detector 300 may be mounted on the outer wall of the case 100 in a movable form as described below.

In addition, a separate vacuum window 500 is mounted at a portion where the light generator 200 and the light detector 300 are connected to the case 100 so that the light generator 200 and the light detector 300 may be protected. And the light generator 200 and the light detector 300 are separated from the measurement chamber C. The light detector 300 includes at least one of an interference filter 320 and an absorption filter 330. It is preferable that the above is mounted.

The interference filter 320 removes light in a specific wavelength region and is mounted in front of the light receiving sensor 310 so that light other than the parallel light L generated from the light generator 200 receives the light detector 300. Do not Absorption filter 330 is to reduce the amount of incident light as a whole to reduce the overall scale of the device by mounting the front of the light receiving sensor 310 to reduce the amount of light received by the light receiving sensor 310 as a whole. Can be. Preferably, the interference filter 320 and the absorption filter 330 are sequentially disposed in front of the light receiving sensor 310.

On the other hand, the light absorption type particle measuring apparatus according to an embodiment of the present invention, as shown in Figure 4 and 5 parallel light (L) passing through the measurement chamber (C) can be changed so that the parallel light ( It may be configured to further include at least one reflective mirror 600 reflecting L). The reflective mirror 600 may be directly installed in the clean room 10 when the light generator 200 and the light detector 300 are directly mounted in a facility such as the clean room 10. When the unit 200 and the light detector 300 are mounted to the case 100 communicated with the pipe 11 of the clean room 10, the unit 200 and the light detector 300 may be installed inside the case 100.

For example, two reflective mirrors 600 may be mounted as shown in FIG. 4, and two reflective mirrors 600 reflect two paths of parallel light L passing through the beam expander 230 of the light generator 200. This can be changed through the mirror 600. In this case, the reflective mirror 600 should be disposed so that the final path of the parallel light L can reach the fixedly arranged light detector 300.

As such, when the path of the parallel light L changes through the reflective mirror 600, the distribution state of the particles may be measured in a more optimal state. In more detail, the particles present in the measurement chamber (C) flow in a constant direction according to the flow of the fluid in the clean room 10 equipment as described above, wherein the flow path through which the particles flow is generally a fluid It is formed along the central part of the measuring chamber C along the flow of the. According to this characteristic, the path of the parallel light L is preferably formed to pass through the central portion of the measurement chamber C, and is received by the light detector 300 whenever the particle passes through the parallel light L. The intensity of light is reduced, thereby determining the size and number of particles as described above. However, since the flow of particles in the measurement chamber C may vary depending on the equipment structure and conditions of use, the path of parallel light L is adjusted to the state most suitable for the flow of particles, respectively, depending on the environment of use. It is preferable to be. Therefore, the particle measuring apparatus according to an embodiment of the present invention adjusts the path of the parallel light L in an optimized state according to the use environment through the reflection mirror 600 capable of adjusting the path of the parallel light L. Thus, more accurate measurement results can be obtained.

In addition, the light absorption type particle measuring apparatus according to an embodiment of the present invention, as shown in FIGS. 4 and 5, the reflection mirror (100) to adjust the reflection angle with respect to the parallel light (L) of the reflection mirror 600 It is preferable to further include an actuator 610 for adjusting the mounting angle of the 600. The actuator 610 may form a path of various parallel lights L optimized according to the use environment.

In addition, in the light absorption type particle measuring apparatus according to the exemplary embodiment of the present invention, in response to the path change of the parallel light L by the reflective mirror 600, the light detector 300 may measure the measurement chamber C or the case ( 100) to be movable. That is, when the path of the parallel light (L) optimized according to the measurement environment is formed in a refracted shape as shown in FIG. 5, the light detector 300 may be mounted to move correspondingly. The light generator 200 and the light detector 300 are not positioned in a straight line. According to such a structure, the light absorption type particle measuring apparatus according to the exemplary embodiment of the present invention may obtain more accurate measurement results.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a perspective view showing a schematic shape of a light absorption type particle measuring apparatus according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line “A-A” of FIG. 1 to conceptually show an internal structure of a light absorption type particle measuring apparatus according to an embodiment of the present invention;

3 is a conceptual diagram illustrating a conceptual enlarged view of a structure of a light generating unit of a light absorption type particle measuring apparatus according to an exemplary embodiment of the present invention;

4 and 5 are conceptual views conceptually illustrating an operating state of a reflection mirror of the light absorption type particle measuring apparatus according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: case 200: light generating unit

210: laser diode 220: parallel light lens module

230: beam expander 300: light detector

320: interference filter 330: absorption filter

Claims (8)

In the light absorption type particle measuring device for detecting the amount of light absorbed and extinguished by the particles to measure the distribution of the particles flowing in the measurement chamber, A light generator for generating light to pass through the measurement chamber; And An optical detector which receives and detects light passing through the measurement chamber And light generated by the light generating unit is parallel light passing through the measurement chamber in parallel. The method of claim 1, The light generating unit A laser diode for generating laser light; And Parallel light lens module for converting the laser light generated by the laser diode into parallel light Light absorption type particle measurement device comprising a. The method of claim 2, The parallel light lens module A plurality of focusing lenses for focusing the laser light into one focal point; And A plurality of parallel light lens for converting the laser light passing through the focus into parallel light Light absorption type particle measuring apparatus comprising a. The method of claim 2, The light generating unit And a beam expander for expanding or reducing the diameter of the parallel light converted through the parallel light lens module. The method of claim 2, The light detector And at least one of an interference filter for removing light in a specific wavelength region and an absorption filter for reducing the amount of light. 6. The method according to any one of claims 1 to 5, And at least one reflecting mirror reflecting the parallel light so that the path of the parallel light passing through the measuring chamber can be changed. The method of claim 6, Light absorbing particle measurement device further comprises an actuator that can adjust the reflection angle of the reflection mirror. The method of claim 7, wherein And the light detector is movable to the measuring chamber so as to receive the parallel light in response to the path change of the parallel light by the reflection mirror.

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