JPH0450499A - Vacuum pump protective device - Google Patents

Abstract

PURPOSE:To protect a turbo pump securely when a power is eliminated or failed by giving a second in-rotation signal to a protective means instead of a first in-rotation signal till a predetermined period passes in a condition where the first in-rotation signal or an in-stoppage signal is not existing. CONSTITUTION:A vacuum pump makes a vacuum in a vacuum chamber 5 through a turbo-molecular pump 3 and a dry pump 4 provided on the discharge side of this pump 3. The vacuum pump has a turbo pump in-rotation signal B outputting means 1A for giving an in-rotation signal B to a protective means instead of an in-rotation signal A till a predetermined period passes in a condition where at least the in-rotation signal A or an in-stoppage signal is not existing. When a controller 31 of the turbo-molecular pump 3 is failed, therefore, a correct in-rotation condition of the turbo-molecular rust 3 can be grasped, thereby a sufficient protection of the turbo pump 3 can be realized.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a vacuum pump protection device for reliably protecting a vacuum pump attached to a CVD apparatus for semiconductor manufacturing, even when a pump controller goes down.

[Conventional technology]

FIG. 1 is a system configuration diagram as an embodiment of the present invention, and the conventional technology will be explained below using this diagram. Note that conventionally, the turbo pump rotation signal B output means IA in the general computer 1 is not provided. In Fig. 1, 1 is a computer that centrally manages the entire system;
2 (2-1, 2-2) are dedicated controllers that control the vacuum equipment under the control of the control computer 1, and 2-1 is the dedicated controller that controls the pumps, valves, etc. in Fig. 1. , 2-2 is a dedicated controller for controlling means not shown. 3 is a turbo molecular pump (also simply called a turbo pump),
31 is a pump controller that controls this turbo pump 3 under the command of the dedicated controller 2-1, 4 is a dry pump, 5 is a vacuum chamber for reaction, 10 (10-1, 10-2)
is a valve. 8 is a hard interlock circuit,
This controls opening/closing of each valve 101.10-2. 9 is a vacuum gauge, and 11 is a high-speed communication line. Further, 31A is a pump status signal sent from the pump controller 31 to the dedicated controller 2-1, and this status signal 3
1A is the pump controller 31 (therefore, the turbo pump 3
) from the signal indicating the presence or absence of power supply, and the accelerating, constant speed, and decelerating signals indicating that the turbo pump 3 is performing acceleration operation, constant speed operation, and deceleration operation respectively in the power supply state. Become. Here, a turbo pump rotation signal A, which will be described later, is created from the OR conditions of the signals during acceleration, constant speed, and deceleration. First, in order to bring the vacuum chamber 5 into a high vacuum state, a dedicated controller 2
An ON signal for the dry pump 4 is output to the dry pump 4, and the dry pump 4 starts rotating. Next, open the valve 10-1,
While the turbo molecular pump 3 is stopped, the inside of the pump 3 is evacuated. At this time, the timing to open the valve 10-2 changes depending on the degree of vacuum in the vacuum chamber 5. If the degree of vacuum in the vacuum chamber 5 is much higher than that on the turbo molecular pump 3 side, air will flow backwards. Turbo molecular pump 3
Wait until the operation becomes possible, open the valve 10-2, and finally turn on the turbo molecular pump 3. It takes about 20 to 30 minutes for the turbo molecular pump 3 to reach a steady rotation speed. Thereby, the vacuum chamber 5 can be drawn to a high vacuum state. Conversely, the case where the pump is stopped will be explained. To stop the vacuum chamber 5 while maintaining it in a high vacuum state, first close the valve 10.
-2 is closed, and then the turbo molecular pump 3 is turned off. At this time, the pump controller 31 slowly stops the pump, taking about 30 minutes while applying the brakes, to completely stop the pump. Furthermore, the dry pump 4 must continue to rotate until it completely stops because it is necessary to ensure exhaust pressure. Therefore, after the turbo molecular pump 3 has completely stopped, the valve 1O-1 is closed and the dry pump 4 is turned off.
and exit. Next, the hard interlock circuit 8 that protects the turbo molecular pump 3 will be explained. Valves 1 are installed on the intake side and exhaust side of the turbo molecular pump 3 to protect the pump.
As an example of installing 0-2 and 10-1, if the dry pump 4 suddenly stops during evacuation,
If exhaust pressure of the turbo molecular pump 3 cannot be secured and the dry pump 4 stops while the turbo molecular pump 3 is rotating, the dedicated controller 2-1 connects the intake side and exhaust air via the hard interlock circuit 8. Both side valves 10-2 and 10-1 are protected by a hard interlock that instantly closes them. This hard interlock is performed using the aforementioned turbo pump rotation signal A generated from the pump status signal 31A sent from the turbo molecular pump controller 31 to the dedicated controller 2-1. Therefore, this turbo-molecular pump rotation signal A is a very important signal, and accurate information indicating the state of the turbo pump must be given in any case while the turbo pump is rotating.

[Problem to be solved by the invention]

Normally, this turbo-molecular pump rotation signal A goes up from the turbo-molecular pump controller 31 to the dedicated controller 2-1, but if the pump controller 31 stops even temporarily due to a power outage, even if the power is restored. , the pump controller 31 cannot grasp the current rotational state of the turbo pump 3, and the turbo molecular pump rotating signal A
It stops coming. The reason for this is that the pump controller 3
1 is because control signals for turning ON and OFF the turbo pump 3 are output, but the actual rotational state of the pump 3 is not detected. In reality, during a power outage, the brake is not applied to the turbomolecular pump 3, and it continues to rotate due to inertia, and it takes approximately one hour to stop. Therefore, it is determined that the turbo molecular pump 3 is stopped even though it is actually rotating, and the dry pump 4
Even if the turbo molecular pump 3 stops, the hard interlock circuit 8 will not work and the turbo molecular pump 3 will be destroyed. Therefore, conventionally, as a method for accurately obtaining the turbo-molecular pump rotation signal A, in order to constantly ensure the pump status signal 31A coming from the pump controller 31 that controls the turbo-molecular pump 3 to the dedicated controller 2-1, A method was used in which the pump controller 31 itself was backed up by a battery. However, this method has a problem in that if the pump controller 31 goes down even temporarily for some reason, the turbo pump rotation signal A stops coming up and accurate information cannot be obtained. Therefore, the present invention provides a controller 31 for a turbo molecular pump 3.
An object of the present invention is to provide a vacuum pump protection device that can accurately know the rotational state of a turbomolecular pump 3 and protect it even if the turbomolecular pump 3 goes down.

[Means to solve the problem]

In order to solve the above-mentioned problems, the device of the present invention uses a turbo molecular pump (such as 3) and a dry pump (such as 4) provided on the discharge side of this pump (such as vacuum chamber 5). A vacuum pump that performs evacuation, and is further provided in a vacuum pipe on the suction side of the turbo molecular pump and a vacuum pipe between the turbo molecular pump and the dry pump, and is provided with a vacuum pipe on the suction side of the turbo molecular pump and a vacuum pipe between the turbo molecular pump and the dry pump, respectively. Pulp (10-2, 10-1, etc.) that opens and closes the passage, and outputs a first rotating signal (rotating signal A, etc.) when the turbo molecular pump is rotating under normal power supply. , means for outputting a stop signal when the dry pump is stopped (such as the pump controller 31), and protection for closing the two valves when the first rotating signal is output when the dry pump is stopped. Means (dedicated controller 2-1. Hard interlock circuit 8
etc.), at least until a predetermined period of time elapses in which the first rotating signal and the stopping signal do not exist, a second rotating signal is sent to the protection means in place of the first rotating signal. It is assumed that the pump is equipped with means (turbo pump rotation signal B output means 14, etc.) for giving a rotation signal (rotation signal B, etc.).

[For use]

Control computer 1 outputs OR with turbo pump rotation signal A.
The control computer 1 constantly monitors the pump status signal 31A and generates a new turbo pump rotation signal B that acts on the dedicated controller 2-1 under the conditions, and when the pump controller 31 (therefore the turbo pump 3) loses power or goes down. Even if the pump controller 31 goes down, the time is memorized and the turbo pump rotation signal B is reset (invalidated) after a sufficient period of time has elapsed until the rotation of the turbo pump 3 due to inertia stops. , the turbo pump 3 can be reliably protected.

【Example】

The present invention will be described in detail below with reference to FIGS. 1 to 3. In the present invention, as described above, the turbo pump rotation signal B output means IA is provided in FIG. FIG. 2 is a flowchart showing the operation of checking the rotation of the turbo molecular pump 3, which is executed by the general computer in FIG. 1 at regular intervals of one second. FIG. 2 is a detailed flowchart of the stop check routine of FIG. Note that the following reference numbers 31 to Sll represent the steps in FIG. 2.
21 to S39 indicate the steps in FIG. 3, respectively. Next, FIG. 2 will be explained with reference to FIG. 1. The supervising computer 1 is a dedicated controller 2-1゜2-2
It is connected by a high-speed communication line 11 and exchanges information. Here, the computer 1 receives the turbo pump 3 via the pump status signal 31A from the dedicated controller 2-1.
Information on the presence or absence of power supply, accelerating, decelerating, stopping, and constant speed can be transmitted quickly and cyclically (several 100 m5ec).
(Sl). Here, the computer 1 is activated when the turbo pump controller 31 (therefore, the turbo pump 3) is powered on, and at a timing during acceleration or constant speed (S29 branch, if the pump controller 31 was not powered until the previous check). (TPON
= 0), or every 60 seconds (a cycle that is sufficiently short for the time required to decelerate the turbo pump) (TPCNT = 60)
(33, branch Y), set the flag indicating that the pump controller power supply is present (TPON=1) (33A), set the turbo pump rotating signal B (S4), and import the current date and time (
S5), the captured current date and time and the rotating signal B are sent to the dedicated controller 2-1 and stored therein (S6). If 60 seconds have not elapsed yet (S82 branch, increment the 1 second car position time counter TPCNT and (
311), return to step S1. Also, read the pump status signal 31A and if there is no turbo pump power supply (Sl-
32, branch N), invalidate the pump controller power source flag (TPON=O) (S7), and proceed to step S8. When it is determined in step S8 that 60 seconds have passed (branch Y)
, reset the timing counter TPCNT=1) (S9
) After executing the turbo pump stop check routine shown in FIG. 3 (SIO), the process returns to step S1 and the above operations are repeated. Next, FIG. 3 will be explained with reference to FIG. 1. The supervising computer 1 reads the turbo pump status signal 31A again in the same way as step S1 in FIG.
), the turbo pump status flag current value NTP is set according to each status (822-530). That is, when there is no turbo pump power supply (322, branch N),
When the pump status flag is set to NTP-1, the turbo pump power source is present (S22. Branch Y), and the pump is accelerating (S23. Branch Y).
, pump status flag NTP = 2 (527), also when the speed is constant (S23. Branch N-4 S24. Branch Y)
, the pump status flag NTP is set to 1 (328), while the pump is decelerating (S 24. Branch N-325° branch Y), the pump status flag NTP is set to 3 (529), and the pump status flag is also accelerating and constant speed, When neither is decelerating (S2
5. Branch N), pump status flag NTP= as stopped
O (326). Then, from the dedicated controller 2-1, the turbo pump 3
Reads the latest time when the was rotating under normal power supply (that is, accelerating, constant speed, or at a constant speed).
S31), then read the current date and time (S32), compare it with the above time, calculate the difference, and if a certain amount of time (sufficient time for the turbo pump to stop) has elapsed by the current date and time (333). (branch Y), the turbo pump 3 is considered to have stopped, and the rotating signal B is reset (S35). Also, although a certain period of time has not elapsed in step S33 (S
33. Branch N), if the engine was decelerating last time and is stopping this time (that is, at a normal stop), the turbo pump rotating signal B is similarly reset (334° branch Y-335). Then, the supervisory computer 1 notifies the dedicated controller 2-1 via the communication line 11 that the turbo pump 3 has stopped (338). In response to this, the dedicated controller 2-1 outputs a rotating/stopping signal to the hard interlock circuit 8. Next, the supervisory computer 1 stores the current value NTP of the turbo pump status flag as the previous value LTP (S39). Note that if a certain period of time has not elapsed in step S33 (branch N), and if it was decelerated last time and not stopped this time (branch N), the turbo pump rotating signal B is activated immediately after the power of the supervising computer 1 is turned on. Set (S
36. branch Y-337) and kept as is (S
36. Branch N), proceed to step S38. Furthermore, the turbo pump rotation signal B output means I in FIG.
The function of A corresponds to step S6 in FIG. 2 and step 33B in FIG.

【Effect of the invention】

According to the invention, a turbomolecular pump 3 and a turbomolecular pump 3 are provided.
A vacuum pump that evacuates a vacuum chamber 5 via a dry pump 4 provided on the discharge side of the turbo-molecular pump 3, and further includes an evacuation line on the suction side of the turbo-molecular pump 3 and a dry pump 4 provided on the discharge side of the turbo-molecular pump 3. Valves 10-2 and 10-1 are provided in the evacuation line between the dry pump 4 and the valves 10-2 and 10-1 to open and close the respective line, and the turbo molecular pump 3 rotates under normal power supply. a pump controller 31 that outputs a rotating signal A when the dry pump 4 is stopped, and a pump controller 31 that outputs a stopping signal when the dry pump 4 is stopped; Two pulps 10-1, 10-2
Dedicated controller 2-1 as a protective means for closing. In the vacuum pump equipped with a hard interlock circuit 8, at least until a predetermined period of time in which the rotating signal A and the stopping signal do not exist, a rotating signal B is sent to the protection means in place of the rotating signal A. Since the turbo pump rotation signal B output means IA is provided as a means for giving the turbo pump rotation signal B, even if the controller 31 of the turbo molecular pump 3 goes down, the accurate rotation state of the turbo molecular pump 3 can be grasped. Therefore, sufficient protection of the turbo pump 3 can be realized.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram as an embodiment of the present invention, FIG. 2 is a flowchart showing the main operations of FIG. 1, and FIG. 3 is a detailed flowchart supplementing FIG. 2. 1: Supervisory computer, IA: Turbo pump rotation signal B output means, 2 (2-1, 2-2): Dedicated controller, 3: Turbo molecular pump (turbo pump), 31:
Pump controller, 31A: pump status signal, 4-nid dry pump, 5: vacuum chamber, 8-nid interlock circuit, 9: vacuum gauge, 10 (101, 1O-2): valve,
11. Communication line. Jo 1 picture ga 2 picture

Claims (1)

[Scope of Claims] 1) A vacuum pump that performs evacuation via a turbo-molecular pump and a dry pump provided on the discharge side of the pump, further comprising: a valve provided in a conduit and a vacuum conduit between the turbo molecular pump and the dry pump to open and close the conduit, and the turbo molecular pump rotating under normal power supply; means for outputting a first rotating signal when the dry pump is stopped, and a means for outputting a stopping signal when the dry pump is stopped; In the vacuum pump equipped with a protection means for closing two valves, the first rotation signal is not applied to the protection means until at least a predetermined period of time has elapsed in which the first rotation signal and the stop signal do not exist. A vacuum pump protection device characterized by comprising means for providing an alternative second rotation signal.