JPS638995A - Disaster prevention multi-stage alarm equipment for clean room - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a disaster prevention alarm system in a clean room of a semiconductor manufacturing factory where semiconductors and the like are manufactured using flammable gas.

"Prior Art" As is well known, a clean room is a room in which airborne dust in the atmosphere or dust generated indoors is removed as quickly as possible, and the air in the area is always kept in a highly clean state. It is called a dust-free room. Among these lean rooms, especially clean rooms for the purpose of manufacturing semiconductors, 7 run (SiH) gas, which is essential in the process of manufacturing semiconductors, is used, or this solan gas has strong twisting properties and spontaneous ignition. It is absolutely necessary to have alarm equipment for possible leaks, gas leaks, etc.

Conventionally, disaster prevention warning equipment has been such that a device capable of detecting leaked Solan gas using a low-potential electrolytic sensor is placed near equipment that uses this Solan gas.

``The point that the invention is trying to solve'' However, in the above-mentioned conventional disaster prevention alarm system that simply places gas leak detectors around equipment that uses Solan gas, in the unlikely event that the gas leak detector malfunctions, If there is no back-up in case of leakage gas, the leakage gas will not be detected unless it reaches a certain concentration due to intensive ventilation with high indoor flow rate to maintain indoor cleanliness, resulting in reliability problems. There was a problem that it was inferior to

This invention was made in view of the above-mentioned circumstances, and by changing the warning range to be detected, it is possible to ensure detection and also grasp the expanding range (scale) of the disaster (accident). Its purpose is to provide highly reliable disaster prevention alarm equipment for clean rooms.

Therefore, in order to achieve the above object, the present invention provides a disaster prevention alarm system in a clean room of a semiconductor manufacturing factory that manufactures semiconductors using flammable gas. a gas leak sensor installed in the piping of the clean room to detect the leakage of the flammable gas; and a duct particulate installed in the ventilation exhaust duct of the clean room to detect the leaked gas and combustion products generated by combustion of the leaked gas. a detection device;
The apparatus further includes an indoor sensor installed on the ceiling within the clean room to detect a fire within the clean room.

"Function" According to the present invention, firstly, leakage gas generated at the joints of gas equipment is detected and an alarm is issued, and secondly, leakage gas or alarm is generated in the duct section that returns (exhausts) air in the room. Detects and alarms combustion products generated by combustion of leaking gas,
Thirdly, a warning can be issued in stages according to the scale of the danger of a disaster, such as by detecting the spread of fire to indoor parts and equipment due to the combustion of leaked gas.

``Example'' The present invention will be described in detail below with reference to FIGS. 1 to 3.

In FIG. 1, the space indicated by the symbol 1 as a whole is a clean room for manufacturing semiconductors.

An air supply port 3 is provided at the top of the clean room 1 to supply purified and extremely clean air to the room 2, while an exhaust duct 5 is provided at the bottom of the floor 4 to exhaust the air from the room. Furthermore, the floor surface 4 is constructed with a nightshade such as a grating, so that clean air can always be ventilated into the room 2. Further, a semiconductor manufacturing equipment 6 is installed inside the clean room 1, and silane gas used in manufacturing semiconductors is supplied to the semiconductor manufacturing equipment 6 in parentheses from a cylinder 7 through a pipe 8. There is.

A gas leak sensor 9 is attached to the connecting portion of the pipe 8 to detect leakage of silane gas. As this gas leak sensor 9, this embodiment proposes the use of one as shown in FIG.

This is a gas leak sensor main body 9a that has two temperature sensors (temperature detection elements) 12 and a comparison calculation circuit 13 built-in.
and a thermally conductive portion I4 made of a good thermal conductor such as copper, which is provided in series with the temperature sensor 12 and extends outward from the sensor body 9a. 1
The distal end of the pipe 4 is formed into a clamp shape corresponding to the outer shape of the pipe 8, so that the heat conduction part 14 can be attached in a state in which it is in contact with the surface of the arrangement 8. The comparison calculation circuit 13 compares and calculates the detection signals from the two temperature sensors I2, and the detection signal of the temperature sensor 12 and the comparison signal from the comparison calculation circuit 13 are sent to an alarm panel (not shown) via a cable 15a. The temperature changes of the pipe 8 itself and the surroundings of the pipe 8 are monitored at two measurement points, and the temperature changes at these measurement points or the temperature difference between the measurement points and these changes over time are monitored. Gas leakage from the pipe 8 can be detected based on the difference from the reference value. The alarm panel issues an alarm based on the detection signal and the comparison signal.

Further, the exhaust duct 5 includes a duct particulate detection device 1.
0 is attached. Particulate particle detection device for ducts! 0
In this embodiment, we propose the use of something as shown in FIG. This includes a duct unit 16 fitted into the exhaust duct 5 as a part thereof, at least one conduit 17 disposed within the duct unit 16,
A particulate detector 19 is connected to the conduit 17 via a plumber 8 and fixed to the outside of the duct unit 16 to detect particulates in the airflow flowing through the exhaust duct 5; The device is equipped with a pump 20 for sucking air from the detector 19 to the detector 19. The signal from the particle detector 19 is led to the control panel (not shown) via a cable 15b.

Furthermore, an indoor sensor 11 is attached to the ceiling of the indoor room 2 of the clean room l. This indoor sensor 11 is equivalent to a temperature detector or a smoke detector that is generally attached to the indoor ceiling of a concrete structure communal building or the like. Detection signals from this indoor sensor I+ are guided to the control panel via a cable.

Next, the operation of the disaster prevention alarm equipment configured as described above will be explained.

Under normal conditions, that is, when no gas leaks from the silane gas pipe 8, the surface temperature of the pipe 8 is considered to be approximately the same as room temperature, and the temperature between the two temperature sensors 12,
Since there is no difference between the temperature detected by each of these two temperature sensors 12 and the data stored as a normal state, the alarm panel does not issue any alarm.

When silane gas leaks from a joint of the pipe 8, etc., and this leaked gas spontaneously ignites and burns, the resulting heat is transmitted by the air and the pipe 8 and spreads to the surroundings.

Therefore, the heat is transferred to the temperature sensor via the heat conduction part i4! Based on the detection signals from these temperature sensors 12 and the comparison/arithmetic circuit I3, it is detected that a gas leak has occurred in the vicinity of the thermally conductive section 14, and an alarm buzzer is sounded, an alarm lamp is lit, and the gas is detected. Notify of leak occurrence.

Now, let's consider a case where silane gas leakage is not detected by the gas leakage sensor 9 due to the location of the gas leakage, the influence of indoor ventilation with a high air flow rate, or an abnormality in the gas leakage sensor 9. . As already mentioned, in a clean room, in order to constantly purify the air in the room, a large amount of clean air is constantly supplied into the room from the air supply port 3, and at the same time, the air in the room is passed through the exhaust duct 5.
It is emitting more. Therefore, combustion products generated by natural combustion of the leaked gas or the leaked silane gas, ie, silica (Sing) smoke particles, etc. inevitably reach the exhaust duct 5. By the way, this exhaust duct 5
As described above, since the duct @rako detection device 10 is provided, fine particles of silane gas or silica are detected by the particle detector 19 of this duct particle detection device 10, and this detection signal is transmitted by the cable 15b. The information is transmitted to the control panel and an alarm is issued. Moreover, in a clean room, the ventilation cycle is short and air moves quickly in the room 2, so silane gas or silica reaches the exhaust duct 5 in a short time, even if it is not detected by the gas leak sensor 9. , a warning is issued at an early stage of an accident situation.

If silane gas spreads to indoor parts or various equipment, or a so-called fire occurs, the indoor sensor 11 attached to the ceiling of the indoor room 2 detects the smoke or temperature rise caused by this and issues an alarm. It transmits the detection signal to the panel.

According to the multi-stage alarm system for disaster prevention with the above configuration, firstly, it detects leakage gas generated at the joints of gas equipment and issues an alarm, and secondly, it returns (exhausts) the air in the room. Other methods such as detecting leaked gas or combustion products generated by combustion of leaked gas in the duct and issuing an alarm, and thirdly detecting and issuing an alarm regarding the spread of fire to indoor parts and equipment due to the combustion of leaked gas. Not only does this provide backup for the Senna, improving the reliability of the system as a disaster prevention warning system, but it also makes it possible to grasp the extent of the danger of a disaster by differentiating the warnings from these three sensors, for example. Furthermore, by utilizing this, for example, a shutoff device that automatically shuts off the supply of silane gas to the piping 8 according to the signal from the alarm panel, and the duct 5 is automatically connected to the duct particle detection device IO. When the gas leak sensor 9 detects an abnormality, the gas supply is automatically cut off, and when the duct particle detection device IO detects an abnormality, the exhaust duct 5, and furthermore, when the indoor sensor 12 detects an abnormality, the fire sprinkler is activated for extinguishing a fire. It is possible.

In this embodiment, the gas leak detection device 9 is attached to the piping 8 and detects the leakage of NOLAN gas, which detects the heat caused by the combustion of NOLAN gas as described above. However, the present invention is not limited to this, and may be one that directly senses chlorine gas, for example. Further, the duct particulate detection device IO installed in the exhaust duct is not limited to the one described above, and for example, the present applicant etc. has already proposed a
It has a light emitter and a photoreceptor that does not normally receive the light from the emitter, and when particles fly between them, the photoreceptor senses the presence of the particles due to the diffuse reflection of these particles and issues a detection signal. It may be something like this.

"Effects of the Invention" As explained above, the present invention provides a disaster prevention alarm system installed in the flammable gas piping in a clean room of a semiconductor manufacturing factory that uses flammable gas to manufacture semiconductors. a gas leak sensor for detecting leakage of the combustible gas; a duct particulate detection device installed in the ventilation exhaust duct of the clean room for detecting leaked gas and combustion products generated by combustion of the leaked gas; Since it is equipped with an indoor sensor installed on the ceiling of the clean room to detect a fire in the clean room, firstly, it detects leakage gas generated at the joints of gas equipment and issues an alarm, and secondly Return (exhaust) air from indoor areas to
Thirdly, it detects leakage gas or combustion products generated by the combustion of leaked gas in the duct section and issues an alarm, and thirdly, it detects and issues an alarm regarding the spread of fire to indoor areas and equipment due to the combustion of leaked gas. Not only does this provide backup for the sensors in these three locations, improving the reliability of the system as a disaster prevention alarm system, but it also makes it possible to understand the extent of the spread of disaster risk by distinguishing the alarms from these three sensors as different from each other. It has excellent effects such as:

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the present invention together with a schematic sectional view of a clean room 1, FIG. 2 is a front view showing a gas leak sensor, and FIG. 3 is a perspective view showing a particulate detection device for a duct.

Claims (1)

[Claims] Disaster prevention alarm equipment in clean rooms of semiconductor manufacturing factories that use flammable gas to manufacture semiconductors, etc.
A gas leak sensor installed in the flammable gas piping to detect leakage of the flammable gas; and a gas leak sensor installed in the ventilation exhaust duct of the clean room to detect leaked gas and combustion products generated by combustion of the leaked gas. A multi-stage alarm system for disaster prevention in a clean room, comprising: a particulate detection device for a duct; and an indoor sensor installed on the ceiling of the clean room to detect a fire within the clean room.