JPS63257223A - Cooling system - 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 [Field of Industrial Application] The present invention relates to a cooling device for precisely moving equipment, and particularly to a cooling device suitable for an exposure device for semiconductor manufacturing.

[Conventional technology]

In order to equalize the temperature of conventional Mr main frame equipment, the general method is to place the entire exposure equipment in a chamber with circulating air that is controlled to a uniform temperature. The machine 411, which requires high precision, is insulated and the air around the installation 1 is exhausted to the outside of the upper air chamber through an exhaust duct.

However, for heat sources that are built into devices that require precision, such as the drive motor of the positioning stage or the image sensor of the position detection optical system, it is necessary to mount them with the above-mentioned insulation or install an exhaust duct. Since there is no heat exchanger and there is only circulation of air at a uniform temperature, a rise in temperature is unavoidable.

The above space problem can be solved by installing a heat exchanger that flows cooling water controlled at a constant temperature into the heat generating part, but in order to minimize the temperature rise, the flow rate of cooling water must be considerably increased ( The piping must have a large diameter and high pressure resistance, and it is difficult to install it in a device such as a positioning stage where the heat generating part needs to move with high precision.

There are thermosiphons and heat pipes as devices that discharge heat from a heat generating part with a slight temperature difference.

As shown in Fig. 4, the hydraulic fluid 1 is inside the sealed pipe 16.
7y! r, put a small amount and vacuum it. 1 end 1 of pipe 16
When B is heated, the working fluid becomes vapor and moves toward the other end 19 as shown by arrow 20. When the other end 19 is cooled, the vapor condenses and returns to liquid and returns to the heating section as shown by arrow 21. The thermosiphon uses gravity to return the condensate to the heating section, with the heating section at the bottom and cooling at the top, and the middle section is connected so that the liquid can flow smoothly. In heat pipes, a wick is placed inside the pipe and the surface tension of the liquid moves the condensate to the heating section, so there are fewer restrictions on placement than thermosiphons, but the cooling capacity is smaller.

Regarding this heat pipe etc., the heat pipe (translated by Kinji Ito)
Gakukensha) described on pages 1 to 5.

[Problems to be solved by the invention] In order to apply the above heat pipe to cooling the heat generating part in order to equalize the temperature of precision equipment: First, there are restrictions on the layout (the piping must be directed from the heat generating part to the cooling part). It is necessary to install the device so that the height of the device increases little by little, making it difficult to apply it to exposure equipment.

Furthermore, since it has a sealed structure, it must be made strong enough to withstand internal pressure increases during rest, making it difficult to attach to a device such as a positioning stage in which the heat generating part moves with high precision.

An object of the present invention is to provide a cooling device that discharges heat from a heat generating part with a temperature increase of only ρ, requires a small space for discharge (and is easy to install even in a moving device). be.

[Means for solving the problem] The above purpose is to send working fluid from a condensing section provided outside a moving precision device to a heat generating section using a pump.

This is achieved by returning the steam to the condensing section at atmospheric pressure through another pipe. [Operation] The working fluid is sent by a pump to the heating section S corresponding to the calorific value of the heating section, and is evaporated there. Absorbs heat from heat generating parts. By adjusting the flow rate of the pump so that it absorbs the same amount of heat as the amount of heat generated, temperature changes in the heat generating part can be eliminated.

Since the heat is absorbed by the latent heat of the working fluid, only a small amount of working fluid is required, and the liquid sending pipe can be thin and flexible, allowing for flexible connections. In the condensing section, the steam is cooled at atmospheric pressure and liquefied.Since the steam pipe is used at atmospheric pressure, its pressure resistance is low (use a flexible plastic hose).

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The cooled microinjection pump 1 pumps the working fluid into a thin pipe 2.
and a heat exchanger 5 fixed to the heat generating part 4 via the expansion valve 5.
Inject into. It is connected to a condensing vessel 8 via a vibrotube that is thicker than the heat exchanger 5 and a solenoid valve 7. The inside of the container is cooled by an ordinary refrigerator 8, and the temperature is controlled so that the boiling point of the working fluid is equal to the atmospheric pressure. The upper part of the container 8 is connected to a vacuum pump 11 via a solenoid valve 10 to exhaust air mixed in the steam. During normal operation, the magnetic valve 10 is closed and the container 8
After the internal temperature reaches a predetermined value, the solenoid valve 7 is opened. When the operation is stopped, the pressure rises due to the temperature rise in the tank, and to prevent the thick vibro from bursting, solenoid valve 7'! ! −
close. The pump controller 12 adjusts the operating speed of the injection pump 1 in proportion to the electric power supplied to the heat generating part 4.
By doing so, it is possible to balance the amount of heat generated and the amount of heat absorbed, and prevent temperature changes in precision equipment. Refrigerant R2 in the working fluid
When No. 1 is used, when the container temperature reaches about 7'C, the vapor pressure becomes close to atmospheric pressure.

The temperature of the pump is preferably cooled to about 0° C. by another refrigerator 16. When air is mixed into the steam, the pressure increases, which is detected by the pressure gauge 14VC, the solenoid valve 7 is closed, the solenoid valve 10 is opened, and the vacuum pump 11 sucks and exhausts the steam.

If there is a lot of air mixed in, use vacuum pump 1 as shown in Figure 2.
1 and open the solenoid valve 10 to the outside air. In this case, the cooling temperature of the container 8 is further lowered to reduce leakage of the working fluid.

Since the temperature of the thin vibrator 2 and the thick vibrator is lower than the target temperature of the precision equipment (about 23° C.), the temperature of the thin pipe 2 is raised to the V atmosphere temperature by the heat exchanger 15. Furthermore, the capacity of the heat exchanger 5 is increased to increase the temperature of the steam exiting to the thick vibro.

FIG. 6 shows an embodiment of the heat generating section 4 and the heat exchanger 5. The motor 22 is a heat generating part and is fixed to the bracket 24 via a heat insulating spacer 26'.A pipe 25 is wound around the outer circumference of the motor 22 as a heat exchanger.
A thin pipe 2 for supplying working fluid is connected to the inlet of the pump via an expansion valve 6. When the pump 1 operates and the pressure in the thin pipe 2 increases, the ball 26 in the expansion valve is pushed and the working fluid enters the pipe 25.

Since the pressure inside the pipe is close to atmospheric pressure, the working fluid evaporates and its temperature drops. As a result, the motor 22 can be cooled, and the heat transferred from the motor 22 to the bracket 24 or the surrounding air can be reduced to zero.

In the above embodiment, there was only one pump and one heat generating part, but it is also possible to supply working fluid to a plurality of heat generating sources from a plurality of pumps and use a common container.

〔Effect of the invention〕

As described above, according to the present invention, heat is absorbed by the latent heat of evaporation, and the amount of absorbed heat can be quickly matched with the amount of heat generated by adjusting the rotation speed of the pump, so that the temperature rise in the heat generating part can be avoided ( In addition, since the evaporation pressure is set to atmospheric pressure, steam piping with low pressure resistance can be used, flexible piping can be provided for moving parts, and the positioning accuracy of moving parts does not deteriorate due to piping.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing another embodiment of the condensing vessel section shown in FIG. 1, and FIG. FIG. 4, a diagram showing an embodiment, is a diagram for explaining heat transfer by a conventional heat pipe. 1...Microinjection pump, 2.6...Piping. 4... Heat generating part, 5... Heat exchanger. 8... Condensation container, 9... Freezer. 12...Pump controller. 1st country

Claims (1)

[Scope of Claims] 1. A pump, a heat generating part close to a precision device, a heat exchanger in contact with the heat generating part, a condensing container, and a refrigerator for cooling the condensing container; The steam generated in the heat exchanger is sent to the heat exchanger, and the steam generated in the heat exchanger is guided to the condensation vessel, where the steam is cooled to a lower temperature than the heat generating part and liquefied, and then recirculated to the pump. Features a cooling device. 2. The cooling device according to claim 1, wherein the pressure of the steam in the heat exchanger and the condensing container is close to atmospheric pressure (0.5 Kg/cm^2 to 1.5 Kg/cm^2) .