JPH0153573B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a monitoring device for monitoring the supply of various chemical solutions used in chemical treatment processes for electronic materials such as semiconductors, precision equipment parts, etc. This invention relates to a monitoring device that is connected to the returnable can to detect the amount of the chemical and stably supply the chemical to the chemical treatment process from the closed returnable can.

Advances in microfabrication technology for integrated circuits, transistors, etc. are remarkable, and requirements for quality control of the various chemicals used in their manufacture are becoming increasingly strict. Particularly, the contamination of fine particulate foreign matter, which has a linear effect on the product yield, is contraindicated, so the liquid is usually subjected to precision filtration and filled into a clean container in a clean environment (inside a clean room) to become a product. Generally, about 1 to 8 glass bottles are used as the container. However, since the filling of various chemical solutions into glass bottles is carried out in an open environment, although in a clean room, it is difficult to avoid the possibility of contamination with dust, foreign matter, etc., even if it is not as high as in the outside air. Moreover, at the distribution stage, the glass bottle has the drawback of being easily damaged, and since the container itself is disposable, there is a problem in how to deal with it. Furthermore, the user must take the time to open the glass bottle and transfer it to the container of the equipment on the production line for integrated circuits, etc., and in doing so, dust and foreign matter may get mixed in with the contents, which have been carefully cleaned using a precision filter. Problems may arise, such as spilling or, in extreme cases, spilling or overflowing. Therefore, the present inventor proposed a liquid level pressurization method that can be easily used by connecting to the piping of the chemical treatment process without having to open the package to transfer the contents each time it is used, and that eliminates the above drawbacks. A sealed storage container was developed and a separate patent application was filed (patent application filed in 1982).
No. 130876 (Unexamined Japanese Patent Publication No. 59-21021).

In this case, since the returnable can has been newly used for this purpose, it can hold a larger amount than conventional glass bottles, but depending on the material of the returnable can, monitoring of the liquid volume may be difficult. However, because the amount is large, it is difficult to constantly monitor the decrease and replace the chemical, and if the chemical processing equipment is operated without knowing that the chemical has run out, untreated defective products may There is a risk of manufacturing.

The present invention solves the above-mentioned drawbacks, detects and supplies the chemical solution while maintaining a clean state without exposing it to the outside air, and issues an alarm when an appropriate amount of liquid remains. Even while replacing the empty returnable can, the chemical solution can be continuously supplied without stopping the chemical solution processing device, and
The rationalized arrangement of device members provides a compact chemical solution supply monitoring device that is extremely easy to operate.

The device of the present invention is installed between a closed type returnable can that transfers chemical liquid using a liquid level pressurization method and a chemical liquid processing process, and the chemical liquid sent from the returnable can is transferred to the closed type monitoring tank of the present invention. The liquid enters the tank, maintains equilibrium with the gas pressure above the liquid level in the liquid level monitoring tank, and is sent to the next chemical treatment process.

Next, to explain the function of this device, after the chemical solution in the returnable can is exhausted and becomes empty, the liquid level in the liquid level monitoring tank drops to a predetermined position, when the returnable can should be replaced. At the same time, the pipe line between the returnable can and the liquid level monitoring tank and the air supply line for pressurized gas to the returnable can are cut off so that the returnable can can be replaced. By introducing gas to pressurize the liquid level, it is possible to supply liquid to the chemical treatment process even while the returnable can is being replaced, and even while the chemical from the replaced returnable can is being transferred to the liquid level monitoring tank. This device enables the supply of chemical liquid, and by combining it with a gas supply source for pressurizing the liquid level in returnable cans, the monitoring tank has the function of an alarm container and a cushion tank when replacing the can. be.

Next, the above functions will be specifically explained based on the drawings. FIG. 1 is a perspective view of a canister 10, which is a returnable can in which a chemical solution 20 is stored, and FIG. 2 is a longitudinal cross-sectional view of the same. The flange 14 is equipped with a male coupler 11 for liquid transport and a male coupler 12 for gas flow, and the couplers 11, 1
2 is protected by a cap 30 in the manner shown in FIG. 3 or 4.

FIG. 5 explains a conventional technique in which the canister is connected to the semiconductor manufacturing apparatus 1. That is, clean nitrogen is supplied to the canister 10 from the female coupler 17 of the nitrogen line and the male coupler 12 for gas distribution, and the chemical solution 20 is supplied to the device 1 using the pressure from the female coupler 16 of the liquid line and the male coupler 11 for liquid transport. and used.

Originally, if semiconductor manufacturing equipment had a function that could detect the liquid usage status, such as an integrated flow meter, it could be used in this state, but if the liquid in the returnable can is used up, The equipment for switching to new returnable cans becomes extremely complicated.

FIG. 6 shows a drug solution supply monitoring device 100 according to the present invention.
In the schematic description, this device includes a liquid level monitoring tank 50 that stores a predetermined amount of a chemical solution 20, and a liquid level gauge 8 that detects the liquid level.
0, connection port 70 for the pressurized gas (nitrogen) introduction pipe that serves as the supply force for the chemical solution, connection port 9 for the tank pressurized gas exhaust pipe
0, solenoid valves 61, 62, 63, 64 for opening and closing circuits for nitrogen gas and chemical solutions, female couplers 17, 16 for connecting the device 100 to the canister 10, which is a returnable container, and process chemicals to the semiconductor manufacturing device 1. Connection port 73 of liquid sending pipe, piping that is a circulation circuit for nitrogen gas and chemical solution, and the solenoid valves 61, 62, 63, 6
4. Consists of a power supply circuit for operating the liquid level gauge 80, an operation switch for an operation panel (not shown), and a power supply circuit for display.

The principle of use of this device is to send the liquid in the canister 10 to the liquid level monitoring tank 50 of the device using nitrogen pressure, maintain a predetermined liquid level while detecting the liquid level with the liquid level gauge 80, and monitor the liquid level. The chemical liquid is sent from the tank 50 to the device 1, and as the chemical liquid is used, the liquid volume decreases, the canister 10 becomes empty, and the liquid level in the liquid level monitoring tank 50 falls below a predetermined chemical liquid. Then,
The liquid level gauge 80 detects this and issues an alarm, and the user knows from the alarm that the liquid level in the canister 10 is empty and replaces it with a canister 10 filled with chemical liquid. be. At the same time, a feature of this apparatus is that even while the canister is being replaced, the semiconductor manufacturing apparatus 1 can be operated using the remaining liquid in the monitoring tank. The state of use will be explained in detail with reference to FIGS. 6 to 9. The arrangement indicated by the thick line in the figure indicates that a circuit is formed.

The male couplers 12 and 11 of the canister 10 and the female couplers 17 and 16 of the device 100 are connected. Purified nitrogen adjusted to 0.5 to 1.0 Kg/cm ² G is supplied to the connection port 70. Supply a predetermined amount of power.
(Fig. 6) Press the start switch (not shown) on the operation panel to start operation. As shown in FIG. 7, when the liquid level gauge 80 senses that the liquid level in the liquid level monitoring tank 50 is below a predetermined level, the solenoid valve 61 opens and the canister 1
Pressure 0. At the same time, the solenoid valve 64 opens to create a circuit for the chemical solution, and the solenoid valve 63 of the tank pressurized gas exhaust pipe opens to create a nitrogen escape port, automatically discharging the chemical solution into the liquid level monitoring tank 50 under nitrogen pressure. The liquid is sent to
(This state is called filling.) As shown in FIG. 8, when the liquid level in the liquid level monitoring tank 50 reaches a predetermined position, the liquid level gauge 80 detects it and
3 is closed, the connection port 90 of the pressurized gas exhaust pipe inside the tank is closed, and the liquid level rises in the liquid level monitoring tank 50 until it reaches equilibrium with the nitrogen pushing pressure, and the inflow of liquid stops. As long as the liquid exists in the canister, this state becomes a steady state and the use of the chemical liquid in the semiconductor manufacturing apparatus 1 is started. (referred to as in use).

With use, the liquid in the canister 10 continues to flow into the liquid level monitoring tank 50, and the canister 10 eventually becomes empty, and the liquid level in the liquid level monitoring tank 50 begins to drop, and when it falls below a predetermined level, the liquid level gauge 80 is activated to issue an alarm and display it on the operation panel. (referred to as Kara).

At the same time, as shown in FIG. 9, the solenoid valves 61 and 64 close to disconnect the circuit from the canister 10, and the solenoid valve 62 opens to apply nitrogen pressure to the liquid level monitoring tank 50, making the remaining liquid usable. . Since the lower end of the chemical liquid feeding pipe opens at the bottom of the monitoring tank, it can be used in this state as long as there is residual liquid.

Following the alarm, the operator replaces the canister with a filled canister while residual liquid is still present.

Then, when you press the reset button (not shown) on the operation panel, it will go into the "filling" state mentioned above.
Liquid feeding from the canister 10 is started. In this case, the solenoid valve 63 of the liquid level monitoring tank 50 opens and the connection port 90 of the pressurized gas (nitrogen) exhaust pipe opens, and the pressure in the liquid level monitoring tank 50 decreases. Using an orifice or the like, the outflow amount from the pipe connection port 90 is made to be less than the amount pushed in from the canister, so that the pressure in the liquid level monitoring tank 50 becomes a positive pressure with respect to atmospheric pressure, piping resistance, and head difference. Since the adjustment is made so that the semiconductor manufacturing apparatus 1 can continue to be used even in this state, it is possible to continue using the semiconductor manufacturing apparatus 1.

As described above, by skillfully controlling the pressure in the liquid level monitoring tank 50, the present invention not only issues a liquid level alarm, but also enables continuous use even when the canister 10 is replaced. A supply monitoring device for dispensing medicinal fluids with advantages is presented.

Based on the principle of this device, for example, the liquid level gauge 80 can be a capacitance type liquid level gauge, a float type liquid level gauge,
Alternatively, it can be used depending on the purpose, such as a phototube type liquid level gauge. Furthermore, it is also possible to adopt a pneumatic actuation system instead of operating electric power, and the present invention is not restricted in any way no matter which one is adopted.

Further, according to the principle of the present invention, the rising liquid level in the liquid level monitoring tank 50 reaches equilibrium due to the pressure in the monitoring tank, and the liquid level gauge outputs a detection signal, so that a predetermined level can be detected. Although one liquid level gauge is sufficient to perform the function, it is also possible to use one or two level gauges to detect two points: low level and high level.

Various other methods can be considered, but the main point is:
A canister, which is a returnable canister, is connected to semiconductor manufacturing equipment via a chemical liquid supply monitoring device, and is used to alert the presence or absence of chemical liquid and the timing of replacing the canister. The method of detecting the liquid level does not limit the present invention in any way.

In addition, in order to remove foreign substances in the chemical liquid or gas, it is also possible to provide a filter or the like at a desired position of the pipe through which the chemical liquid or gas flows.

In addition, the materials used for the purpose of the present invention include:
It must not generate foreign substances such as rust due to corrosion, and it must not be contaminated by the drug by being eluted or dispersed into the drug, and the selection is based on the usual method depending on the target drug. Tests must be carried out in accordance with the following to confirm that the product is usable. Common examples include SUS304, SUS316, Teflon,
Examples include polypropylene, polyethylene, polyvinyl chloride, SUS304, SUS316 with Teflon lining, and fiber-reinforced polypropylene plastics, but as mentioned above, they can be used depending on the properties of the drug. It is obvious that the material does not limit the present invention in any way.

The mechanism of the device of the present invention has been schematically explained above, but such a chemical supply can is installed in close proximity to the chemical treatment process, and can be installed in a narrow space using the usual piping installation method. It is extremely difficult to make it compact, and the arrangement of the control valves and connection of piping are important requirements from the viewpoint of operation, inspection, etc.

The device of the present invention solves the above problems, does not take up much space, and is extremely easy to operate, inspect, etc. That is, Fig. 10 is a schematic structural diagram of the observation tank;
As shown in the detailed view of the upper part of the observation tank in Figure 12 and the plan view of the pedestal in Figure 12, the pedestal 500 has a substantially truncated conical shape, and the threaded part 200 of the neck of the monitoring tank 50 and the mounting threaded part 400 of the pedestal. are screwed together and can be removed, and the pedestal and canister are airtightly connected. Each solenoid valve 6 is placed on the seat plate 501 of the pedestal.
1, 62, 63, 64 and the head of a liquid level gauge 80 are attached. In addition, there is a cover 5 on the pedestal.
04 is covered to protect the level gauge of the solenoid valve. The connection port of the returnable chemical liquid receiving pipe provided with the coupler 16 opens to the outside of the conical pedestal side wall 503 between the seat plate 501 and the lower partition plate 502 of the pedestal, penetrates the side wall, and connects to the solenoid valve 64. An opening 102 exits from the solenoid valve 64 and passes through the lower partition plate to the liquid level monitoring tank 50.
form. The process chemical liquid feed pipe passes through the partition plate from the opening 103 at the bottom of the liquid level monitoring tank 50 and opens as a connection port 73 through the side wall. The pressurized gas introduction pipe enters the space between the seat plate of the pedestal and the lower partition plate from an appropriate position on the side wall, and the pipe 300 branches into two routes. One enters the solenoid valve 61, exits from the solenoid valve 61, and enters the side wall. It opens to the outside and a coupler 17 is attached. The other side enters the solenoid valve 62, exits the solenoid valve 62, passes through the lower partition plate, becomes the opening 101 of the pressurized gas introduction pipe into the liquid level monitoring tank 50, and also serves as the opening 101 for the pressurized gas introduction pipe in the tank. The exhaust pipe passes through the bottom partition plate from the opening 104 and ends at the connection port 90 from the solenoid valve 63 through the side wall 503 . Further, the detection section 105 of the liquid level gauge is inserted into the monitoring tank through the lower partition plate 502.

Since this monitoring device has the structure described above,
The connections of the respective tubes are made on the side walls of all pedestals, which saves space and is very convenient to operate. In addition, only one connection to the nitrogen supply source is required, and the supply of nitrogen to the canister and valve operation are performed in the main monitoring tank, making the operation very easy. In addition, since the liquid level gauge and electromagnetic valve are installed together on the pedestal, inspection and maintenance are convenient, and the circuit connecting to the operation panel (not shown) can be done all together in an orderly manner. This further enhances the effectiveness of using the device.

[Brief explanation of drawings]

Figure 1 is a perspective view of a sealed returnable can, Figure 2 is a longitudinal sectional view of the can, Figures 3 and 4 are detailed views of the flange of the returnable can, and Figure 5 is a diagram of the returnable can manufacturing equipment. An explanatory diagram showing a conventional connection method, FIG. 6 is a system diagram of a device in which the drug solution supply monitoring device according to the present invention is connected.
7 to 9 are schematic explanatory diagrams showing the principle of use of the device of the present invention, FIG. 10 is a schematic structural diagram of the observation tank of the device of the present invention, and FIG. 11 is a detailed front view of the pedestal.
FIG. 12 is a plan view of the same. DESCRIPTION OF SYMBOLS 1... Semiconductor manufacturing equipment, 5... Cart for transporting returnable cans, 10... Canister, 11... Male coupler for liquid transportation, 12... Male coupler for gas distribution, 1
3...Liquid storage returnable can body, 14...Flange, 1
6... Liquid line female coupler, 17... Nitrogen line female coupler, 20... Chemical solution, 30... Cap, 50... Liquid level monitoring tank, 61 to 64... Solenoid valve, 70... Pressurization Gas introduction pipe connection port, 80...
Liquid level gauge, 90...connection port for pressurized gas exhaust pipe inside the tank,
100... Chemical solution supply monitoring device, 200... Monitoring tank neck threaded part, 400... Pedestal mounting threaded part, 500
... Pedestal, 501 ... Seat plate, 502 ... Lower partition plate, 503 ... Pedestal side wall, 504 ... Cover.

Claims (1)

[Claims] 1 Closed type with a liquid receiving pipe connected to a closed returnable tank, a liquid sending pipe connected to the chemical treatment process, a pressurized gas introduction pipe, and a pressurized gas exhaust pipe in the tank, each equipped with a liquid level gauge via a valve. A valve opening/closing control mechanism is provided which is connected to the chemical liquid level monitoring tank and communicates and controls each of the valves, the valve of the pressurized gas inflow pipe of the sealed returnable can, and the liquid level gauge, and A cylindrical pedestal is installed on the surface, and each of the liquid receiving pipe, liquid sending pipe, pressurized gas introduction pipe, pressurized gas exhaust pipe, and returnable pressurized gas inflow pipe is attached to the side wall between the pedestal surface and the tank ceiling surface. The pipe end is opened, and a liquid receiving pipe valve, a pressurized gas introduction pipe valve, a pressurized gas exhaust pipe valve, a pressurized gas inflow pipe valve for returnable cans, and a liquid level gauge head are mounted on the pedestal. A device for monitoring the supply of chemical solutions from sealed returnable cans.