JPH03172732A - Multi-spot measuring instrument and multi-spot measuring method using same - Google Patents

Abstract

PURPOSE:To eliminate the production of particulates such as metal scraps at the time of measuring operation and to easily and accurately take a measurement at low cost by providing a clean room with plural tubes, sampling air, and switching the path where the air flows. CONSTITUTION:An HEPA filter 2 is installed at the ceiling part of the clean room 1 and clean air is supplied from the filter 2. Air vents 4 are formed in the floor surface 3 and the clean air is discharged to below the floor. Plural sampling tubes 11 are provided in the room 1 at desired measurement positions and the tips of the tubes 11 are opened so as to sample the clean air by suction. The tubes 11 are formed of soft synthetic resin so that internal hollow parts are easily blocked with external pressure. The other-end sides of the tubes 11 are connected to a fluid path switching device 12 and the sampled air flows to a gathering header device 13 through the switching operation of the device 12. The device 13 specifies one of plural fluid passages, so particulates can be measured by one light scatter particulate meter 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a multi-point measuring device suitable for use in measuring air cleanliness in semiconductor device manufacturing processes, clean rooms provided in hospitals, etc. and a multi-point measurement method.

[Prior art] Semiconductor devices such as ICs and LSIs are manufactured through ultra-fine processing, and if dust adheres to them, product defects occur, so various operations are performed in clean rooms with purified air. . An example of the structure of a clean room is disclosed in Japanese Patent Laid-Open No. 72947/1983.

As mentioned above, in consideration of the purpose of use of lean rooms,
It is necessary to measure the cleanliness inside the clean room. In order to directly measure how particles such as particles contained in air diffuse, it is necessary to install many particle meters in a clean room and measure them simultaneously at various locations. .

Also, if you want to monitor the concentration of particulates at multiple locations in a clean room, you should install piping and valves to sample air at each measurement location, and then manually or automatically control the valves to sample and measure the air. ,
Alternatively, it is necessary to install a particle meter at each location to be measured and go around collecting measurement data, or to collect the data in one place using communication means.

[Problems to be Solved by the Invention] However, the particle meter (light scattering particle meter) is expensive, and it is economically difficult to install a plurality of light scattering particle meters for simultaneous measurement. In addition, in order to perform measurements using the piping and valves mentioned above, currently, sampling air is sucked in from multiple points using a blower, the fluid path is switched using a rotary valve, and multi-point measurement is performed using a light scattering particle meter. Systems have been proposed but are very expensive.

As for the multi-point measurement system, solenoid valves are used to switch the piping and fluid paths, but it is extremely difficult to construct the piping that serves as the fluid path for the sampling air in a clean state, and the electromagnetic valves Metal scraps are generated when a valve is opened and closed, in other words, when it is switched between an on state and an off state. In this way, the solenoid valve itself generates dust, which not only makes accurate measurements difficult, but also causes metal scraps to be sucked into the optical system of the light scattering particle meter, causing malfunctions.
Also, due to the structure of the solenoid valve, there is a large dead space, and -
If contaminated, the effects will last for a long time, and the resistance loss will be large, which will adversely affect the particle meter's suction pump and the entire particle measurement system.

The present invention has been made in view of the above-mentioned circumstances, and provides a multi-point measuring device and a multi-point measuring method that do not generate fine particles such as metal scraps during measurement, have a simple configuration, and can perform inexpensive and accurate measurements. It is about providing.

[Means for Solving the Problems] The object of the present invention is to sample air by providing a plurality of pipes, in other words, chinives, in a desired space such as a clean room, and to provide a fluid through which the sampled air flows. The fluid path is switched by a fluid path switching device, and the fluid path is changed to one by a collective header device.
/N number of particles, one light-scattering particle meter measures particles in the final fluid path, and the measurement results are stored in a storage means of a computer that controls the fluid path switching device and the light-scattering particle meter. .

Furthermore, another object of the present invention is to control a fluid path corresponding to a first sampling position among a plurality of sampling positions to an open state when performing multipoint measurement using the multipoint measurement device having the above configuration. After the measurement is completed, the fluid path corresponding to the second sampling position is opened, and after a predetermined period of time, the fluid path corresponding to the first sampling position is closed, and the fluid path corresponding to the second sampling position is opened. This is achieved by measuring the fluid obtained from the

[Operation] According to the multi-point measurement device configured as described above, selection of fluid paths corresponding to a plurality of sampling positions is performed by opening and closing a plurality of pipe bodies, and moreover, the fluid paths are collected into one. Therefore, measurement can be performed using one light scattering particle meter depending on the gathering position, and the generation of metal debris in the fluid path can be prevented, and the device can be made at low cost.

Furthermore, in the measurement, the fluid corresponding to the second sampling position is measured after the influence of the fluid corresponding to the first sampling position has disappeared, so that extremely accurate measurement can be performed.

[Example] Hereinafter, an example of a multi-point measuring device and a multi-point measuring method to which the present invention is applied will be described with reference to the drawings.

First, the overall configuration and measurement system of the multi-point measurement device will be explained with reference to FIGS. 1 and 2.

A HEPA filter 2 is installed on the ceiling of the clean room 1, and clean air is supplied from the HEPA filter 2 as shown by the arrow. A ventilation hole 4 is opened in the floor surface 3, and clean air is discharged under the floor.

On the other hand, in the clean room 1, sampling tubes 11 corresponding to a plurality of tube bodies in the present invention are provided at desired measurement positions, and the tip of each sampling tube 11 is opened so that clean air can be sampled by suction. ing. It should be noted that each sampling tube 11 has a structure in which the internal hollow part can be easily closed by external pressure.
It is made of soft synthetic resin or the like.

The other end of each sampling tube 11 is connected to a fluid path switching device 12, and the switching operation of the switching device 12 causes sampling air to flow sequentially or air sampled from a desired position to a collection header device 13. The collection header device 13 collects a plurality of fluid paths into, for example, l fluid paths, and by providing the collection header device 13, sampling air flowing through a plurality of N fluid paths can be specified to, for example, one fluid path. can do. Therefore, even if there are a plurality of sampling positions, only one light scattering particle meter 14 for measuring particles is sufficient. Note that the fluid path switching device 12 and the collective header device 13
The structure will be explained in detail later with reference to FIGS. 3 and 4.

The light scattering particle meter 14 includes an air pump for sucking the sampling air, and is configured to optically measure particles in the sampling air and transmit measurement data to the computer 15. The computer 15 controls the fluid path switching device 12.
It controls the switching drive of the light scattering particle meter 14 and the automatic measurement of the light scattering particle meter 14, and has built-in means for storing measurement data. Note that the functions of the computer 15 may be equivalent to what is called a personal computer among those skilled in the art.

Next, the structure of the fluid path switching device 12 will be explained with reference to FIG.

The fluid path switching device 12 utilizes what is known as a plunger solenoid among those skilled in the art, and includes a solenoid coil 22 within a frame 21, a stem (plunger) 23 that reciprocates due to the magnetism generated from the solenoid coil 22, It consists of an opening/closing member 24 provided perpendicular to the stem 23, a guide groove 26 of the opening/closing member 24 formed on a side plate 25 used for fixing the frame 21, and the like. The sampling tip 11 is positioned between the opening/closing member 24 and the frame 21.

In the fluid switching device 12 configured as described above, when a DC voltage is supplied to the solenoid coil 22 based on a command from the computer 15, the stem 23 is urged downward in FIG. is pressed against the outer surface of the frame 21 to close the internal hollow part. Therefore, by providing a fluid path switching device 12 for each sampling tube 11 as shown in FIG.
The flow of sampling air to the collection header device 13 can be controlled.

Next, the set header device 13 will be explained with reference to FIG.

As shown in FIG. 4(A), the collective header device 13 is constructed by stacking and connecting glass tubes 3I formed in a substantially 7-shape in the flow direction of the sampling air. That is, two branch pipes of the glass tube 31 correspond to a connecting pipe section that connects the two sampling tubes 11, and one branch pipe corresponds to a discharge pipe section.

Two sampling tubes 11 are connected to each of the glass tubes 31 shown in row a on the right side of FIG. 4(B), and the glass tubes 31 shown in row a on the right side of FIG.
The discharge pipe section is connected to the glass tube 31 of row b via the tube 32.
Connected to the connecting pipe section. This connection is made in the same way between column B and column C, so in this embodiment, the number of fluid paths is reduced by a power of two, and one fluid path is finally formed. Therefore, by driving the fluid path switching device 12 and controlling the flow of the sampling air as described above, the sampling air taken in from the desired sampling position flows into the final tube 33.

Then, the light scattering particulate meter 14 measures the sampling air at the desired sampling position, transmits the measurement data to the computer 15, stores it in the storage means, and starts measurement at the next sampling position.

Next, a multi-point measuring method using the multi-point measuring device will be explained.

To start measurement, the computer 15 drives the fluid path switching circuit 12 and all sampling stations 11
Controls the open state. Next, the sampling tube 11 placed at the first sampling position is opened,
All fluid paths using other sampling tubes are controlled to be closed.

As a result, the clean air taken in at the first sampling position flows through the final tube 33.

Wait in this state for about 3 seconds, then light scattering particle meter 1
4, the sampling air taken in from the first sampling position is measured. The light scattering particle meter 14 transmits measurement data to the combinator 15 for each sampling position and completes the measurement, and one measurement is completed in about 10 seconds.

Next, the computer 15 stores the measurement data in a storage means, such as a floppy disk. After detecting the end of the measurement at the first sampling position, while keeping the fluid path at the first sampling position open,
controlling the fluid path formed by the sampling tube 11 installed at the second sampling position in an open state;
This state is continued for about 3 seconds.

That is, for 3 seconds, the air from the first chimney 33 to the first and second sampling positions is transmitted to the light scattering particulate meter 1.
However, during this time, the light scattering particle meter 14 is controlled to be in a standby state and does not perform measurement. Then, after about 3 seconds have elapsed, the sampling tube installed at the first sampling position is controlled to be in a closed state, and after about 3 seconds have elapsed, the same measurement as described above is performed on the sampling air taken in from the second sampling position. .

By performing such measurements, the second sampling air can be measured without being affected by the particle concentration of the first sampling air. The measurement and standby are performed completely automatically under the control of the computer 15, and the floppy disk of the computer 15 stores all measurement results at each sampling position. Therefore, all the fluid paths are not blocked while the measurement is being performed, and the measurement and recording of the particulate concentration at each location in the clean room 1 can be easily performed in an extremely short time. It turns out.

As described above, in the multi-point measuring device and multi-point measuring method of this embodiment, the air corresponding to each sampling position flows through separate sampling tubes, so that the influence of dirt on the sampling tubes can be reduced. Furthermore, since the sampling tube is not controlled to be closed at the same time, the light scattering particle meter can be protected. Furthermore, since the clean air sufficiently flows through the tube to perform a purge action before starting measurement, measurement errors are small.

By forming the collecting header device from glass tubing, the resistance to the fluid can be reduced and particulate deposition can also be reduced.

And since the structure is simple, it is easy to reduce the weight.
It can be easily moved by setting it on casters. Furthermore, since measurements and control can be performed and data can be stored using a personal computer, data analysis and the like can be easily performed.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above.

For example, although the collective header device is formed of a seven-shaped, in other words, three-way glass tube, it may have a structure in which the number of connecting tube portions is further increased.

Although an example has been shown in which Y-shaped glass tubes are stacked and connected by tubes, it is even better to form a desired number of stages of glass tubes in one piece instead of this as shown in FIG. That is, there are fewer joints, less resistance, and less possibility of contamination. In addition, an integrated structure can be made more compactly, and inspection for pinholes and the like can be performed satisfactorily. And it can be created in a clean state.

[Effects of the Invention] As explained above, in the multi-point measurement device to which the present invention is applied, the fluid path that supplies the sampled fluid to the light scattering particle meter opens and closes by suppressing and releasing the pressure on the tube that serves as the fluid path. Therefore, no undesirable antinode or the like is generated in the fluid path. Furthermore, in the multi-point measurement method to which the present invention is applied, after the measurement of the fluid corresponding to the first sampling position is completed, the fluid path corresponding to the second sampling position is opened, and after a predetermined period of time has passed, the fluid path corresponding to the second sampling position is opened. Since the fluid corresponding to the sampling position is measured, the first fluid does not affect the second fluid and accurate measurement can be performed.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, in which Figure 1 is a block diagram of the entire multi-point measuring device, Figure 2 is a block diagram showing fluid flow, and Figure 3 is a block diagram showing the flow of fluid. A configuration diagram of the fluid path switching device, FIG. 4 is an external view and a connection diagram of the collective header device, and FIG. 5 is a diagram showing the collective header integrally formed with a glass Y-shaped tube. Reference numerals in the figure 1...Clean room, 2...HEPA filter, 3...Floor, 11...Sampling tube, 12...Fluid path switching device, 13...Collection header device, 4/5・ 2 ・ 3 ・ 4 ・ 5 ・ 6 ・ Light scattering particle meter, personal computer, frame, solenoid coil, stem, opening/closing member, side plate, guide groove, Y-shaped glass tube. Figure 1

Claims (10)

[Claims] (1) a plurality of tubes provided so that each opening substantially faces a desired position in a desired space; and a fluid path switching device that selects a fluid path formed by the plurality of tubes; A collection header device that forms a fluid path in which the plurality of pipe bodies are collected into 1/N, and a measurement that performs a desired measurement on the fluid passing through the 1/N fluid path formed by the collection header device. A multi-point measuring device comprising: a fluid path switching device, and a control device that controls driving of the fluid path switching device and the measuring device. (2) The fluid switching device includes an opening/closing member for opening/closing the fluid path on a stem driven by energization of a solenoid coil, and a guide mechanism for the opening/closing member and gripping of a tube serving as the fluid path. The multi-point measuring device according to claim 1, further comprising a mechanism. (3) The collective header device includes a plurality of connecting pipe portions that connect the plurality of pipe bodies, and a discharge pipe portion that discharges the fluid introduced from the connecting pipe portions, and the collective header device with this configuration is 2. The multi-point measuring device according to claim 1, wherein a 1/N fluid path is formed by connecting a desired number of connections in a stacked manner. (4) The multi-point measuring device according to claim (1), wherein the measuring device is a light scattering particle meter configured to be driven by the control device to enable automatic measurement. (5) The control device includes a computer having a sequence for driving the measuring device and selectively driving the fluid path switching circuit, and having a storage means for storing measurement results by the measuring device. A multi-point measuring device according to claim (1). (6) The multi-point measurement device according to claim (1), wherein the fluid path switching device comprises an electromagnetic mechanism driven by supplying and cutting off DC power to a solenoid coil. (7) The multi-point measurement device according to claim (1), wherein the fluid path within the fluid path switching device is made of soft synthetic resin. (8) The multi-point measuring device according to claim (1), wherein the collective header device is constructed of a Y-shaped integrally molded glass tube. (9) Measurement is performed by controlling the fluid path at the first sampling position to be open among the plurality of sampling positions, and after the measurement is completed, the fluid path at the second sampling position is controlled to be open, and a predetermined period of time has elapsed. A multi-point measurement method in which the fluid path at the first sampling position is later blocked and the fluid obtained from the second sampling position is measured. (10) The multi-point measurement method according to claim (9), wherein the control for shifting from the first sampling position to the second sampling position is performed sequentially for n sampling positions.