Vacuum pump, control device, and heating time control method

Abstract

To provide a vacuum pump which can shorten a temperature rise time of the pump while protecting a baseboard from a high temperature accompanied by heating, a control device and a temperature rise time control method.SOLUTION: Temperature information is detected from a temperature sensor 3 which is arranged near a heater 1, and inputted into a control device 200. In a temperature rise state determination part of the control device 200, a determination of a temperature rise state is started in a step 1. In a step 3, the inputted temperature information is compared with a rated temperature. The rated temperature is differentiated by a machine type and a specification of the pump, however, defined as a target temperature which is necessary for the prevention of product deposits. Then, as indicated in a step 5, when all of pieces of the inputted temperature information are raised higher than the rated temperature, a post-temperature rise mode is determined, and this processing is finished in a step 9. On the other hand, as indicated in a step 7, in a state that a temperature is lower than the rated temperature, a temperature-rising mode is determined, and this processing is finished in the step 9. After that, operations of the step 1 to the step 9 are periodically repeated.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a vacuum pump, a control device, and a heating-up time control method, and particularly relates to a vacuum pump, a control device, and a heating-up time control method that can protect a substrate from high temperatures associated with heating while shortening the heating-up time of the pump.

Background Art

[0002] With the development of electronics in recent years, the demand for semiconductors such as memories and integrated circuits has been increasing rapidly. These semiconductors are manufactured by doping highly pure semiconductor substrates with impurities to give electrical properties or forming fine circuits on the semiconductor substrates by etching. And these operations need to be performed in a chamber in a high-vacuum state to avoid the influence of dust in the air. For evacuating this chamber, a vacuum pump is generally used, and in particular, a turbo molecular pump, which is one of the vacuum pumps, is frequently used because of its low residual gas and easy maintenance.

[0003] In addition, in the semiconductor manufacturing process, there are many processes in which various process gases are applied to the semiconductor substrate, and the turbo molecular pump is used not only to evacuate the inside of the chamber but also to exhaust these process gases from the chamber. By the way, the process gas may be introduced into the chamber in a high-temperature state to enhance reactivity.

[0004] And when these process gases are cooled to a certain temperature when being exhausted, they may become solid and deposit products in the exhaust system. And this kind of process gas may become low-temperature and solidify inside the turbo molecular pump, and may adhere and deposit inside the turbo molecular pump. When deposits of the process gas accumulate inside the turbo molecular pump, this deposit narrows the pump flow path and causes a decrease in the performance of the turbo molecular pump.

[0005] To solve this problem, conventionally, a heater and an annular water-cooling pipe are wound around the outer periphery of the pump of a turbo molecular pump, and a temperature sensor is embedded near the heater, for example. Based on the signal of this temperature sensor, the heater is heated so that the temperature around the heater is maintained at a high temperature within a certain range (see Patent Document 1). Since it is difficult for products to deposit when the control temperature is higher, it is desirable to make this temperature as high as possible.

[0006] On the other hand, a printed circuit board on which semiconductor elements and the like are mounted is disposed in the electrical component section. When the base section is heated to a high temperature in this way, the temperature of the printed circuit board may exceed the limit temperature of the semiconductor element. For this reason, from the viewpoint of safety, in order to prevent the temperature of the electrical component section including the printed circuit board from exceeding the limit temperature of the semiconductor element, cooling water is usually constantly flowed through the water-cooling pipe.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, the above temperature control cannot meet all of the following requirements (1) to (3). (1) Constantly water-cool the base section to prevent malfunction or failure of the printed circuit board due to high temperature. (2) To shorten the heating-up time, stop the water-cooling of the base section during the heating-up process. (3) When the limit temperature of the semiconductor element is exceeded during the heating-up process, start water-cooling for cooling.

[0009] Here, for (1), it can be realized by constantly water-cooling without intervention of a controller. However, when both (1) and (2) are to be realized, usually the valve of the water-cooling pipe (water-cooling valve) may be constantly open, but it is necessary to stop it in a certain section (during the heating-up process). When attempting to control this with a controller, in the above-described temperature control, in order to maintain the target temperature around the heater, it will turn on and off between the upper limit temperature and the lower limit temperature. Therefore, control that satisfies all of (1) to (3) cannot be achieved.

[0010] The present invention has been made in view of such conventional problems, and an object thereof is to provide a vacuum pump, a control device, and a temperature rise time control method that can shorten the temperature rise time of a pump while protecting a substrate from high temperatures associated with heating.

Means for Solving the Problems

[0011] Therefore, the vacuum pump of the present invention (Claim 1) includes a heating part in which a heater is disposed at at least one location to prevent the generation of deposits, a base part in which a cooling mechanism is disposed to prevent the interior of the electrical component part from becoming high temperature, base part temperature measurement means for measuring the temperature of the base part, a water cooling valve for controlling whether to perform cooling by the cooling mechanism, and temperature determination means for determining whether it is after the temperature rise or during the temperature rise based on whether all the temperatures of the heater disposed in the heating part exceed a preset set temperature. The water cooling valve is controlled based on the determination result by the temperature determination means and the temperature measured by the base part temperature measurement means.

[0012] It is determined whether it is after the temperature rise or during the temperature rise based on whether all the temperatures of the heater disposed in the heating part exceed a preset set temperature. Then, based on the result of this determination and the temperature measured at the base part, the water cooling valve is controlled. Thereby, shortening of the temperature rise time of the pump can be realized while safely protecting the semiconductor element.

[0013] Further, the vacuum pump of the present invention (Claim 2) is characterized in that when it is determined by the temperature determination means that the temperature is rising and the temperature measured by the base part temperature measurement means is equal to or lower than the cooling temperature lower limit value, cooling by the cooling mechanism is not performed.

[0014] Thereby, shortening of the temperature rise time of the pump during the temperature rise can be realized.

[0015] Furthermore, the vacuum pump of the present invention (Claim 3) is characterized in that cooling by the cooling mechanism is performed when the temperature measured by the base portion temperature measuring means is equal to or higher than the cooling temperature upper limit value.

[0016] By performing cooling control based on the temperature measured at the base portion around the electrical component portion, it is possible to appropriately manage the temperature of the electrical component portion.

[0017] Furthermore, the vacuum pump of the present invention (Claim 4) is characterized in that the cooling temperature upper limit value is set to the maximum temperature value at which the substrate disposed in the electrical component portion can be protected or a temperature value having a predetermined margin with respect to the limit temperature value.

[0018] Thereby, when the limit temperature of the semiconductor element is exceeded, cooling by the cooling mechanism is performed, so that failures and abnormalities due to the high temperature of the semiconductor element can be prevented and it is safe.

[0019] Furthermore, the vacuum pump of the present invention (Claim 5) is characterized in that cooling by the cooling mechanism is performed when it is determined by the temperature determination means that the temperature has risen.

[0020] When the temperature rise is completed, the water cooling valve is always in an open state. Thereby, it is possible to protect the substrate from the high temperature associated with heating.

[0021] Furthermore, the vacuum pump of the present invention (Claim 6) includes heating unit temperature measuring means for measuring the temperature of the heating unit, the set temperature has a heating temperature lower limit value and a heating temperature upper limit value, and heating by the heater is performed when the temperature measured by the heating unit temperature measuring means is equal to or lower than the heating temperature lower limit value, and heating by the heater is stopped when the temperature measured by the heating unit temperature measuring means is equal to or higher than the heating temperature upper limit value.

[0022] Thereby, a high temperature can be maintained at parts other than the base portion, and deposition of products can be stably prevented.

[0023] Furthermore, the vacuum pump of the present invention (Claim 7) is characterized in that a heating region by the heating unit and a cooling region of the base unit including the electrical component unit are thermally partitioned.

[0024] Thereby, heat conduction to the mutual regions can be prevented, so that more reliably, shortening of the temperature rise time of the pump can be realized while safely protecting the semiconductor element.

[0025] Furthermore, the present invention (Claim 8) is a control device for a vacuum pump, including a heating unit provided with a heater at at least one location to prevent generation of deposits, a base unit provided with a cooling mechanism to prevent the inside of the electrical component unit from becoming high temperature, base unit temperature measurement means for measuring the temperature of the base unit, and a water cooling valve for controlling whether or not to perform cooling by the cooling mechanism. The control device is characterized in that it includes temperature determination means for determining whether it is after temperature rise or during temperature rise based on whether all temperatures of the heater exceed a preset set temperature, and controls the water cooling valve based on the determination result by the temperature determination means and the temperature measured by the base unit temperature measurement means.

[0026] Furthermore, the present invention (Claim 9) is a method for controlling the temperature rise time of a vacuum pump, including a heating unit provided with a heater at at least one location to prevent generation of deposits, a base unit provided with a cooling mechanism to prevent the inside of the electrical component unit from becoming high temperature, base unit temperature measurement means for measuring the temperature of the base unit, and a water cooling valve for controlling whether or not to perform cooling by the cooling mechanism. The method is characterized in that it determines whether it is after temperature rise or during temperature rise based on whether all temperatures of the heater exceed a preset set temperature, and controls the water cooling valve based on the temperature measured by the base unit temperature measurement means when it is determined that it is during temperature rise.

Advantages of the Invention

[0027] As described above, according to the present invention (Claim 1), temperature determination means is provided to determine whether it is after temperature rise or during temperature rise based on whether all temperatures of the heater exceed a preset set temperature. Since the water-cooling valve is configured to be controlled based on the determination result by the temperature determination means and the temperature measured by the base part temperature measurement means, shortening the temperature rise time of the pump can be achieved while safely protecting the semiconductor element.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0029] Hereinafter, embodiments of the present invention will be described. A longitudinal sectional view of this turbo molecular pump 100 is shown in FIG. 1. In FIG. 1, an intake port 101 is formed at the upper end of a cylindrical outer cylinder 127 of the turbo molecular pump 100. And inside the outer cylinder 127, a rotating body 103 is provided in which a plurality of rotating blades 102 (102a, 102b, 102c ···), which are turbine blades for sucking and exhausting gas, are formed radially and in multiple stages on the circumference. A rotor shaft 113 is attached to the center of this rotating body 103, and this rotor shaft 113 is levitated and position-controlled in the air by, for example, a magnetic bearing with five-axis control. The rotating body 103 is generally made of a metal such as aluminum or an aluminum alloy.

[0030] The upper radial electromagnet 104 has four electromagnets arranged in pairs with respect to the X-axis and the Y-axis. Four upper radial sensors 107 are provided in proximity to this upper radial electromagnet 104 and corresponding to each of the upper radial electromagnets 104. As the upper radial sensor 107, for example, an inductance sensor having a conductive winding or an eddy current sensor is used, and the position of the rotor shaft 113 is detected based on the change in the inductance of this conductive winding that changes according to the position of the rotor shaft 113. This upper radial sensor 107 is configured to detect the radial displacement of the rotor shaft 113, that is, the rotating body 103 fixed thereto, and send it to the control device 200.

[0031] In this control device 200, for example, a compensation circuit having a PID adjustment function generates an excitation control command signal for the upper radial electromagnet 104 based on the position signal detected by the upper radial sensor 107, and an amplifier circuit 150 (described later in FIG. 2) controls the excitation of the upper radial electromagnet 104 based on this excitation control command signal, thereby adjusting the radial position above the rotor shaft 113.

[0032] And this rotor shaft 113 is formed of a high magnetic permeability material (such as iron, stainless steel, etc.) and is attracted by the magnetic force of the upper radial electromagnet 104. Such adjustment is performed independently in the X-axis direction and the Y-axis direction respectively. Also, the lower radial electromagnet 105 and the lower radial sensor 108 are arranged in the same manner as the upper radial electromagnet 104 and the upper radial sensor 107, and the radial position of the lower side of the rotor shaft 113 is adjusted in the same manner as the radial position of the upper side.

[0033] Furthermore, the axial electromagnets 106A and 106B are arranged with a disk-shaped metal disk 111 provided at the lower part of the rotor shaft 113 sandwiched therebetween vertically. The metal disk 111 is composed of a high magnetic permeability material such as iron. An axial sensor 109 is provided to detect the axial displacement of the rotor shaft 113, and its axial position signal is configured to be sent to the control device 200.

[0034] And in the control device 200, for example, a compensation circuit having a PID adjustment function generates respective excitation control command signals for the axial electromagnet 106A and the axial electromagnet 106B based on the axial position signal detected by the axial sensor 109, and the amplifier circuit 150 performs excitation control on the axial electromagnet 106A and the axial electromagnet 106B respectively based on these excitation control command signals. Thus, the axial electromagnet 106A attracts the metal disk 111 upward by magnetic force, the axial electromagnet 106B attracts the metal disk 111 downward, and the axial position of the rotor shaft 113 is adjusted.

[0035] In this way, the control device 200 appropriately adjusts the magnetic force exerted by the axial electromagnets 106A and 106B on the metal disk 111 to magnetically levitate the rotor shaft 113 axially and hold it in space in a non-contact manner. Note that the amplifier circuit 150 for performing excitation control on these upper radial electromagnet 104, lower radial electromagnet 105, and axial electromagnets 106A and 106B will be described later.

[0036] On one hand, the motor 121 includes a plurality of magnetic poles arranged circumferentially so as to surround the rotor shaft 113. Each magnetic pole is controlled by the control device 200 so as to rotationally drive the rotor shaft 113 via the electromagnetic force acting between the magnetic pole and the rotor shaft 113. Further, a rotation speed sensor such as a Hall element, a resolver, or an encoder (not shown) is incorporated in the motor 121, and the rotation speed of the rotor shaft 113 is detected by the detection signal of this rotation speed sensor.

[0037] Furthermore, for example, a phase sensor (not shown) is attached near the lower radial sensor 108 to detect the rotation phase of the rotor shaft 113. In the control device 200, the detection signals of this phase sensor and the rotation speed sensor are used together to detect the position of the magnetic pole.

[0038] A plurality of fixed blades 123 (123a, 123b, 123c ···) are arranged with a slight gap from the rotary blades 102 (102a, 102b, 102c ···). The rotary blades 102 (102a, 102b, 102c ···) are each inclined by a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113 in order to transfer the molecules of the exhaust gas downward by collision. The fixed blades 123 (123a, 123b, 123c ···) are made of, for example, a metal such as aluminum, iron, stainless steel, copper, or an alloy containing these metals as components.

[0039] Similarly, the fixed blades 123 are also formed to be inclined by a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113, and are arranged alternately with the stages of the rotary blades 102 toward the inside of the outer cylinder 127. The outer peripheral ends of the fixed blades 123 are supported in a state of being inserted between a plurality of stacked fixed blade spacers 125 (125a, 125b, 125c ···).

[0040] The fixed-wing spacer 125 is a ring-shaped member and is made of, for example, metals such as aluminum, iron, stainless steel, copper, or alloys containing these metals as components. An outer cylinder 127 is fixed to the outer periphery of the fixed-wing spacer 125 with a slight gap therebetween. A base portion 129 is disposed at the bottom of the outer cylinder 127. An exhaust port 133 is formed in the base portion 129 and communicates with the outside. The exhaust gas that enters the intake port 101 from the chamber (vacuum chamber) side and is transferred to the base portion 129 is sent to the exhaust port 133.

[0041] Furthermore, depending on the application of the turbo molecular pump 100, a threaded spacer 131 is disposed between the lower part of the fixed-wing spacer 125 and the base portion 129. The threaded spacer 131 is a cylindrical member made of a metal such as aluminum, copper, stainless steel, iron, or an alloy containing these metals as components, and a plurality of spiral threaded grooves 131a are engraved on its inner peripheral surface. The direction of the spiral of the threaded grooves 131a is the direction in which the molecules of the exhaust gas are transferred toward the exhaust port 133 when they move in the rotational direction of the rotating body 103. A cylindrical portion 102d hangs down at the lowermost part following the rotating blades 102 (102a, 102b, 102c ···) of the rotating body 103. The outer peripheral surface of this cylindrical portion 102d is cylindrical and protrudes toward the inner peripheral surface of the threaded spacer 131, and is close to the inner peripheral surface of this threaded spacer 131 with a predetermined gap therebetween. The exhaust gas transferred to the threaded grooves 131a by the rotating blades 102 and the fixed-wing 123 is sent to the base portion 129 while being guided by the threaded grooves 131a.

[0042] The base portion 129 is a disk-shaped member that constitutes the base of the turbo molecular pump 100 and is generally made of metals such as iron, aluminum, and stainless steel. Since the base portion 129 physically holds the turbo molecular pump 100 and also serves as a heat conduction path, it is desirable to use a metal with high rigidity and high thermal conductivity such as iron, aluminum, or copper.

[0043] In such a configuration, when the rotary blade 102 is rotationally driven by the motor 121 together with the rotor shaft 113, exhaust gas is sucked from the chamber through the intake port 101 due to the actions of the rotary blade 102 and the stationary blade 123. The rotational speed of the rotary blade 102 is usually 20,000 rpm to 90,000 rpm, and the peripheral speed at the tip of the rotary blade 102 reaches 200 m / s to 400 m / s. The exhaust gas sucked from the intake port 101 passes between the rotary blade 102 and the stationary blade 123 and is transferred to the base portion 129. At this time, the temperature of the rotary blade 102 rises due to frictional heat generated when the exhaust gas contacts the rotary blade 102 and conduction of heat generated by the motor 121. This heat is transferred to the stationary blade 123 side by radiation or conduction by gas molecules of the exhaust gas.

[0044] The stationary blade spacers 125 are joined to each other at the outer peripheral portion, and transfer heat received by the stationary blade 123 from the rotary blade 102 and frictional heat generated when the exhaust gas contacts the stationary blade 123 to the outside.

[0045] In the above description, the threaded spacer 131 is disposed on the outer periphery of the cylindrical portion 102d of the rotating body 103, and the thread groove 131a is engraved on the inner peripheral surface of the threaded spacer 131. However, conversely, there may be a case where a thread groove is engraved on the outer peripheral surface of the cylindrical portion 102d and a spacer having a cylindrical inner peripheral surface is arranged around it.

[0046] Also, depending on the application of the turbo molecular pump 100, the electrical component section composed of the upper radial electromagnet 104, the upper radial sensor 107, the motor 121, the lower radial electromagnet 105, the lower radial sensor 108, the axial electromagnets 106A, 106B, the axial sensor 109, etc. is covered by the stator column 122 around it so that the gas sucked from the intake port 101 does not enter the electrical component section, and the inside of this stator column 122 may be maintained at a predetermined pressure with purge gas.

[0047] In this case, pipes (not shown) are provided in the base portion 129, and purge gas is introduced through these pipes. The introduced purge gas is sent to the exhaust port 133 through the gaps between the protective bearing 120 and the rotor shaft 113, between the rotor and the stator of the motor 121, and between the stator column 122 and the inner peripheral cylindrical portion of the rotary blade 102.

[0048] Here, the turbo molecular pump 100 requires control based on the identification of the model and specific parameters adjusted individually (for example, various characteristics corresponding to the model). To store this control parameter, the turbo molecular pump 100 is provided with an electronic circuit unit 141 inside its body. The electronic circuit unit 141 is composed of electronic components such as a semiconductor memory like EEP-ROM and semiconductor elements for accessing it, and a substrate 143 for mounting them. This electronic circuit unit 141 is housed below, for example, near the center of a rotation speed sensor (not shown) in the base portion 129 that constitutes the lower part of the turbo molecular pump 100, and is closed by an airtight bottom cover 145.

[0049] By the way, in the semiconductor manufacturing process, among the process gases introduced into the chamber, there are some that have the property of becoming solid when their pressure becomes higher than a predetermined value or their temperature becomes lower than a predetermined value. Inside the turbo molecular pump 100, the pressure of the exhaust gas is the lowest at the intake port 101 and the highest at the exhaust port 133. When the process gas is transferred from the intake port 101 to the exhaust port 133, if its pressure becomes higher than a predetermined value or its temperature becomes lower than a predetermined value, the process gas becomes solid and adheres and accumulates inside the turbo molecular pump 100.

[0050] For example, when SiCl4 is used as the process gas in an Al etching apparatus, in a low vacuum (760 [torr] to 10 -2When the pressure is low (about [torr]) and the temperature is low (about 20 [°C]), it can be seen from the vapor pressure curve that solid products (such as AlCl3) precipitate and adhere and deposit inside the turbo molecular pump 100. As a result, when deposits of the process gas accumulate inside the turbo molecular pump 100, these deposits narrow the pump flow path, causing a decrease in the performance of the turbo molecular pump 100. And the aforementioned products were in a situation where they were likely to solidify and adhere at high-pressure parts near the exhaust port 133 and near the threaded spacer 131.

[0051] Therefore, in order to solve this problem, a heater 1 and an annular water-cooling pipe 149 are wound around the outer periphery of the base part 129, etc., and for example, a temperature sensor 3 (such as a thermistor) is embedded near the heater 1, and based on the signal of this temperature sensor 3, the temperature of the base part 129 is maintained at a constant high temperature (set temperature), heating by the heater 1 and cooling by the water-cooling pipe 149 (hereinafter referred to as TMS. TMS; Temperature Management System) are carried out. A water-cooling valve (not shown) is arranged in the water-cooling pipe 149 to control the cooling. However, in order to improve the efficiency of TMS, a heater (not shown) may be further arranged at the exhaust port 133, and a temperature sensor (not shown) may be arranged near this heater. Note that a temperature sensor 5 is arranged near the water-cooling pipe 149 of the base part 129 to control the cooling. Since the heating region formed around the heating part of the heater 1 and the heaters arranged at the exhaust port 133 and the cooling region of the base part 129 including the electrical component part are structurally separated, they are thermally partitioned. As a result, heat conduction to each other's regions can be prevented, and thus more reliably, shortening the pump warm-up time can be achieved while safely protecting the semiconductor element.

[0052] Next, regarding the turbo molecular pump 100 configured as described above, an amplifier circuit 150 for exciting and controlling the upper radial electromagnet 104, the lower radial electromagnet 105, and the axial electromagnets 106A and 106B will be described. The circuit diagram of this amplifier circuit 150 is shown in FIG. 2.

[0053] In Fig. 2, one end of the electromagnet winding 151 that constitutes the upper radial electromagnet 104 etc. is connected to the positive electrode 171a of the power supply 171 via the transistor 161, and the other end thereof is connected to the negative electrode 171b of the power supply 171 via the current detection circuit 181 and the transistor 162. The transistors 161 and 162 are so-called power MOSFETs and have a structure in which a diode is connected between their source and drain.

[0054] At this time, for the transistor 161, the cathode terminal 161a of its diode is connected to the positive electrode 171a, and the anode terminal 161b is connected to one end of the electromagnet winding 151. Also, for the transistor 162, the cathode terminal 162a of its diode is connected to the current detection circuit 181, and the anode terminal 162b is connected to the negative electrode 171b.

[0055] On the other hand, for the current regeneration diode 165, its cathode terminal 165a is connected to one end of the electromagnet winding 151, and its anode terminal 165b is connected to the negative electrode 171b. Similarly, for the current regeneration diode 166, its cathode terminal 166a is connected to the positive electrode 171a, and its anode terminal 166b is connected to the other end of the electromagnet winding 151 via the current detection circuit 181. The current detection circuit 181 is composed of, for example, a Hall sensor type current sensor or an electric resistance element.

[0056] The amplifier circuit 150 configured as described above corresponds to one electromagnet. Therefore, when the magnetic bearing is under five-axis control and there are a total of 10 electromagnets 104, 105, 106A, and 106B, similar amplifier circuits 150 are configured for each of the electromagnets, and 10 amplifier circuits 150 are connected in parallel to the power supply 171.

[0057] Furthermore, the amplifier control circuit 191 is constituted by, for example, a digital signal processor section (hereinafter referred to as the DSP section) (not shown) of the control device 200, and this amplifier control circuit 191 is adapted to switch on / off the transistors 161 and 162.

[0058] The amplifier control circuit 191 is adapted to compare the current value detected by the current detection circuit 181 (a signal reflecting this current value is referred to as a current detection signal 191c) with a predetermined current command value. Then, based on this comparison result, the magnitudes of the pulse widths (pulse width times Tp1, Tp2) to be generated within a control cycle Ts which is one cycle of PWM control are determined. As a result, gate drive signals 191a, 191b having such pulse widths are output from the amplifier control circuit 191 to the gate terminals of the transistors 161 and 162.

[0059] Note that when passing through a resonance point during the acceleration operation of the rotational speed of the rotating body 103 or when a disturbance occurs during the constant speed operation, etc., it is necessary to control the position of the rotating body 103 with high speed and strong force. Therefore, as the power supply 171, a voltage of about 50 V is used, for example, so that a rapid increase (or decrease) in the current flowing through the electromagnet winding 151 can occur. Further, a normal capacitor is connected between the positive electrode 171a and the negative electrode 171b of the power supply 171 for stabilizing the power supply 171 (not shown in the figure).

[0060] In such a configuration, when both of the transistors 161 and 162 are turned on, the current flowing through the electromagnet winding 151 (hereinafter referred to as the electromagnet current iL) increases, and when both are turned off, the electromagnet current iL decreases.

[0061] Also, when one of the transistors 161 and 162 is turned on and the other is turned off, a so-called flywheel current is retained. Then, by flowing the flywheel current through the amplifier circuit 150 in this way, the hysteresis loss in the amplifier circuit 150 can be reduced, and the power consumption of the entire circuit can be kept low. Further, by controlling the transistors 161 and 162 in this way, high-frequency noise such as harmonics generated in the turbo molecular pump 100 can be reduced. Furthermore, by measuring this flywheel current with the current detection circuit 181, the electromagnetic current iL flowing through the electromagnetic coil 151 can be detected.

[0062] That is, when the detected current value is smaller than the current command value, as shown in FIG. 3, both of the transistors 161 and 162 are turned on only once during the control cycle Ts (for example, 100 μs) for a time corresponding to the pulse width time Tp1. Therefore, during this period, the electromagnetic current iL increases toward the current value iLmax (not shown) that can flow from the positive electrode 171a to the negative electrode 171b through the transistors 161 and 162.

[0063] On the other hand, when the detected current value is larger than the current command value, as shown in FIG. 4, both of the transistors 161 and 162 are turned off only once during the control cycle Ts for a time corresponding to the pulse width time Tp2. Therefore, during this period, the electromagnetic current iL decreases toward the current value iLmin (not shown) that can be regenerated from the negative electrode 171b to the positive electrode 171a through the diodes 165 and 166.

[0064] And in either case, after the elapse of the pulse width times Tp1 and Tp2, one of the transistors 161 and 162 is turned on. Therefore, during this period, a flywheel current is retained in the amplifier circuit 150.

[0065] Next, a method for shortening the temperature rise time of the pump while protecting the substrate from the high temperature associated with heating will be described. First, the operation of the temperature control unit of the base portion will be described. Temperature information is detected by the temperature sensor 3 disposed near the heater 1 and input to the control device 200. However, temperature information may also be detected by a temperature sensor (not shown) disposed at the exhaust port 133 and input to the control device 200.

[0066] The control device 200 is provided with a temperature control unit for the base unit. In this temperature control unit for the base unit, as shown in FIG. 5, the operation starts at step 1. At step 10, in order to perform the subroutine processing of the temperature rising state determination unit, the process proceeds to step 2 in FIG. 6. This temperature rising state determination unit corresponds to the temperature determination means. At step 3 in FIG. 6, all the input temperature information is compared with the rated temperature. This rated temperature varies depending on the model and specifications of the pump, but is defined as the target temperature required to prevent product deposition. For example, it is set to 100 to 150 degrees during rated operation. Then, as shown in step 5, when all the input temperature information becomes higher than the rated temperature, it is determined as the post-temperature-rising mode, and the process returns to the temperature control unit of the base unit at step 9. On the other hand, as shown in step 7, when it is in a state lower than the rated temperature, it is determined as the temperature-rising mode, and the process returns to the temperature control unit of the base unit at step 9.

[0067] Subsequently, at step 13 in FIG. 5, it is read whether the result of the determination made at step 3 is the post-temperature-rising mode or the temperature-rising mode. When it is determined as the temperature-rising mode, the process proceeds to step 17 and heating / cooling control is performed. This heating / cooling control can be carried out by diverting the program of the conventionally performed TMS control. Therefore, the modification of the control device 200 can be easily performed in the form of adding a part of the program. The addition of this program is at steps 1 to 9, steps 13, 15, and 19. After that, the operations from step 1 to step 19 are periodically repeated.

[0068] The control device 200 is provided with a heating and cooling control unit. In this heating and cooling control unit, the subroutine processing shown in FIG. 7 is performed. When the process of step 17 is performed, the process proceeds to step 21, and in step 23, the operation of the water cooling valve is selected. Thereafter, in step 25, it is determined whether or not the temperature value measured by the temperature sensor 5 corresponding to the base unit temperature measuring means is equal to or higher than a preset upper limit temperature value for cooling. For example, this upper limit temperature value for cooling is the upper limit temperature at which the substrate 143 can be protected.

[0069] When it is determined in step 25 that the temperature value measured by the temperature sensor 5 is equal to or higher than the upper limit temperature value for cooling, the process proceeds to step 27 and the water cooling valve is opened. It is desirable that this upper limit temperature value for cooling be set with a margin in consideration of the temperature of the electrical equipment section.

[0070] Thereby, by performing cooling control based on the temperature of the temperature sensor 5 measured at the base unit 129 around the electrical equipment section, the temperature management of the electrical equipment section can be appropriately performed. When the limit temperature of the semiconductor element is exceeded in the temperature rising mode, water cooling can be started for cooling, so that failures and abnormalities due to the high temperature of the semiconductor element can be prevented and it is safe.

[0071] On the other hand, when it is determined in step 25 that the temperature value measured by the temperature sensor 5 is less than the upper limit temperature value for cooling, the process proceeds to step 29, and it is determined whether or not it is equal to or lower than a preset lower limit temperature value for cooling. When it is determined that it is equal to or lower than the lower limit temperature value for cooling, the process proceeds to step 31 and the water cooling valve is stopped. This lower limit temperature value for cooling is set to the temperature at which the water cooling returns to off again. Thereafter, the process proceeds to step 33, and thereafter, the processes from step 21 to step 33 are repeatedly performed periodically. On the other hand, when the temperature value measured by the temperature sensor 5 in step 29 exceeds the lower limit temperature value for cooling, the process proceeds to step 33.

[0072] As an example of the temperature rise of the pump, when the pump is replaced, the temperature value measured by the temperature sensor 5 is below the lower limit temperature value for cooling. Therefore, the water cooling valve is stopped and only heated by the heater 1, so the temperature rise time is shortened. As a result, the shortening of the temperature rise time can be realized in the temperature rise mode. Also, when the limit temperature of the semiconductor element is exceeded, water cooling can be performed for cooling by steps 25 and 27, so it is safe.

[0073] Next, the temperature control by the heating and cooling control unit for parts other than the base part will be described. In step 41 of FIG. 8, the temperature control by the heating and cooling control unit for parts other than the base part is started. In step 43, the subroutine process of the heating and cooling control is performed, and the step moves to step 21 of FIG. 7. In step 23, the operation of the heater is selected. Then, it proceeds to step 51, and it is determined whether the temperature value measured by the temperature sensor 3 is equal to or higher than the upper limit temperature value for heating. When it is equal to or higher than the upper limit temperature value for heating, the heater 1 is turned off. On the other hand, when it is less than the upper limit temperature value for heating, it proceeds to step 55, and it is determined whether the temperature value measured by the temperature sensor 3 is equal to or lower than the lower limit temperature value for heating. When it is equal to or lower than the lower limit temperature value for heating, it proceeds to step 57, and the heater 1 is turned on. When it exceeds the lower limit temperature value for heating in step 55, it proceeds to step 33.

[0074] As a result, a high temperature can be maintained in parts other than the base part, and the deposition of the product can be stably prevented. Also, when the mode read in step 13 of FIG. 6 is the post-temperature-rise mode, it proceeds to step 15 and the water cooling valve is opened. That is, when the temperature rise is completed, the water cooling valve is always in the open state. As a result, the substrate 143 can be protected from the high temperature accompanying the heating. That is, regarding the control of the water cooling valve of the base part, in the temperature rise mode, the on / off operation is performed based on the upper limit temperature and the lower limit temperature in the same way as the TMS, and in the post-temperature-rise mode, it is always on.

[0075] Incidentally, if the temperature rising mode is performed while the rotating body 103 is rotating, since the frictional heat generated during rotation and the heat generated from the motor 121 can be utilized, the temperature rising time can be shortened. However, it may also be performed while the rotating body 103 is magnetically levitated and stopped. As described above, it is possible to prevent the deposition of the product while protecting the substrate and shortening the temperature rising time of the pump. Note that the present invention can be variously modified and combined without departing from the spirit of the present invention, and it goes without saying that the present invention also extends to such modified and combined ones.

Explanation of Reference Numerals

[0076] 1 Heater 3, 5 Temperature Sensor 100 Pump Body 102 Rotating Blade 103 Rotating Body 104 Upper Radial Electromagnet 105 Lower Radial Electromagnet 107 Upper Radial Displacement Sensor 108 Lower Radial Displacement Sensor 113 Rotor Shaft 121 Motor 122 Stator Column 127 Outer Cylinder 129 Base Portion 149 Water Cooling Pipe 200 Control Device

Claims

1. a heating section with a heater disposed at at least one location to prevent the formation of deposits; a base section with a cooling mechanism disposed to prevent the interior of the electrical component section from becoming hot; base section temperature measuring means for measuring the temperature of the base section; a water cooling valve for controlling whether or not to perform cooling by the cooling mechanism; temperature determination means for determining whether it is after temperature rise or during temperature rise based on whether all the temperatures of the heaters exceed a preset set temperature; and a vacuum pump, characterized in that the water cooling valve is controlled based on the determination result by the temperature determination means and the temperature measured by the base section temperature measuring means.

2. The vacuum pump according to claim 1, wherein when it is determined by the temperature determination means that the temperature is rising and the temperature measured by the base section temperature measuring means is equal to or lower than the lower limit value for cooling, cooling by the cooling mechanism is not performed.

3. The vacuum pump according to claim 1 or claim 2, characterized in that when the temperature measured by the base section temperature measuring means is equal to or higher than the upper limit value for cooling, cooling by the cooling mechanism is performed.

4. The vacuum pump according to claim 3, characterized in that the upper limit value for cooling is set to the maximum temperature value at which the substrate disposed in the electrical component section can be protected or a temperature value having a predetermined margin with respect to the limit temperature value.

5. The vacuum pump according to claim 1 or claim 2, characterized in that when it is determined by the temperature determination means that the temperature has risen, cooling by the cooling mechanism is performed.

6. including heating section temperature measuring means for measuring the temperature of the heating section; the set temperature has a lower limit value for heating and an upper limit value for heating; The vacuum pump according to claim 1 or claim 2, characterized in that when the temperature measured by the heating section temperature measuring means is equal to or lower than the lower limit value for heating, heating by the heater is performed, and when the temperature measured by the heating section temperature measuring means is equal to or higher than the upper limit value for heating, heating by the heater is stopped.

7. The vacuum pump according to claim 1 or claim 2, characterized in that the heating region by the heating section and the cooling region of the base section including the electrical component section are thermally partitioned.

8. a heating section with a heater disposed at at least one location to prevent the formation of deposits; a base section with a cooling mechanism disposed to prevent the interior of the electrical component section from becoming hot; base section temperature measuring means for measuring the temperature of the base section; A control device for a vacuum pump, comprising a water-cooling valve for controlling whether to perform cooling by the cooling mechanism. It includes temperature determination means for determining whether it is after temperature rise or during temperature rise based on whether all the temperatures of the heaters exceed a preset temperature. A control device characterized by controlling the water-cooling valve based on the determination result by the temperature determination means and the temperature measured by the base portion temperature measurement means.

9. A heating part with heaters arranged at least at one location to prevent the generation of deposits. A base part with a cooling mechanism arranged to prevent the interior of the electrical equipment part from getting hot. Base part temperature measurement means for measuring the temperature of the base part. A method for controlling the warm-up time of a vacuum pump, comprising a water-cooling valve for controlling whether to perform cooling by the cooling mechanism. Determine whether it is after temperature rise or during temperature rise based on whether all the temperatures of the heaters exceed a preset temperature. A method for controlling the warm-up time of a vacuum pump, characterized in that when it is determined that it is during temperature rise, the water-cooling valve is controlled based on the temperature measured by the base part temperature measurement means.

Images