Heat Transfer Fluid Supply System

Abstract

The heat transfer fluid supply system according to one aspect of the present invention may include a body to be cooled having a heat transfer passage formed therein through which a heat transfer fluid passes, a tank in which the heat transfer fluid is stored in a space formed therein, a supply passage connecting the tank and one side of the heat transfer passage, a recovery passage connecting the tank and the other side of the heat transfer passage, and a controller for controlling an internal pressure of the tank.

Description

[Technical field]

[0001] The present invention relates to a heat transfer fluid supply system, and more particularly to a heat transfer fluid supply system capable of controlling the pressure of the heat transfer fluid. [Background technology]

[0002] As the temperature range required for testing semiconductor devices becomes wider, the test environments provided by equipment for testing semiconductor devices become more diverse.

[0003] In particular, in order to control the temperature of a prober chuck supporting a semiconductor device, it is often necessary to use or exceed the limits of the operating temperature range of the heat transfer fluid supplied to the prober chuck.

[0004] At this time, when a heat transfer fluid for controlling the temperature of the prober chuck is used at a low temperature, it is advantageous to use a heat transfer fluid having a low viscosity in consideration of heat exchange performance, limit pressures of piping and pumps, and the like.

[0005] However, in the case of a heat transfer fluid having a low viscosity, there is a problem that the formation of a fluid flow may be restricted due to a low vaporization point.

[0006] In addition, a heat transfer fluid that can be used at high temperatures generally has a problem in that it has a high viscosity at low temperatures, which limits its use in a semiconductor device testing apparatus due to its physical properties, and therefore the temperature of the heat transfer fluid entering the probe chuck is generally set lower than the temperature of the probe chuck before being supplied.

[0007] However, as the difference between the temperature of the heat transfer fluid and the set temperature of the probe chuck increases, the heater that heats the probe chuck requires high output for temperature compensation, which has a negative effect on the temperature uniformity of the probe chuck and reduces yields during semiconductor device testing. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve the above problems, and an object of the present invention is to provide a heat transfer fluid supply system that can increase the vaporization point of a heat transfer fluid that has low viscosity at low temperature and can be used.

[0009] The objects of the present invention are not limited to those mentioned above, and other objects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0010] In order to solve the above problem, a heat transfer fluid supply system according to one aspect of the present invention may include a body to be cooled having a heat transfer flow path formed therein through which a heat transfer fluid passes; a tank in which the heat transfer fluid is stored in a space formed therein; a supply flow path connecting the tank to one side of the heat transfer flow path; a recovery flow path connecting the tank to the other side of the heat transfer flow path; and a control unit for controlling the pressure inside the tank.

[0011] At this time, the apparatus may further include a pressure pump for supplying dry air to the tank, and the control unit may add a predetermined pressure to the internal pressure of the tank through the pressure pump.

[0012] At this time, the apparatus may further include a pressure pump valve provided in the tank so that an inner space of the tank and the pressure pump can communicate with each other.

[0013] At this time, the control unit can control the internal pressure of the tank by controlling opening and closing of the pressure pump valve.

[0014] At this time, the pressure pump can provide a predetermined pressure constantly.

[0015] In this case, the pressure pump may be connected to the tank at a position above the water level of the heat transfer fluid stored inside the tank.

[0016] In this case, the predetermined pressure may be 0.4 bar or more and 0.6 bar or less.

[0017] At this time, the cooling device may further include a heater for heating the object to be cooled, and the control unit may control the temperature of the object to be cooled through the heat transfer fluid and the heater for the object to be cooled.

[0018] At this time, the apparatus may further include a pressure control valve provided in the tank so that an inner space of the tank can be communicated with the outside of the tank.

[0019] At this time, the control unit can control the internal pressure of the tank by controlling opening and closing of the pressure control valve.

[0020] At this time, the control unit can control the internal pressure added to the tank by thermal expansion of the heat transfer fluid passing through the object to be cooled.

[0021] At this time, the apparatus further includes a pressure sensor provided in the tank to measure an internal pressure of the tank, and the control unit can control the internal pressure of the tank by controlling opening and closing of the pressure regulating valve based on pressure information measured by the pressure sensor.

[0022] At this time, the apparatus further includes a temperature sensor provided in the tank to measure the temperature of the heat transfer fluid stored in the tank, and the control unit can control the internal pressure of the tank by controlling the opening and closing of the pressure control valve based on temperature information measured by the temperature sensor.

[0023] At this time, the apparatus further includes a pressure pump that supplies dry air to the tank to provide a constant predetermined pressure; and a pressure pump valve that is provided in the tank to allow communication between the internal space of the tank and the pressure pump; and the control unit can control the internal pressure of the tank by further controlling opening and closing of the pressure pump valve.

[0024] At this time, the control unit may close the pressure pump valve and open the pressure control valve if the temperature information measured by the temperature sensor is lower than a first temperature.

[0025] At this time, the control unit may close the pressure pump valve and the pressure control valve if the temperature information measured through the temperature sensor is equal to or higher than a first temperature, so that the internal pressure of the tank gradually increases due to thermal expansion of the heat transfer fluid passing through the cooled body.

[0026] At this time, the control unit may open the pressure pump valve if the temperature information measured by the temperature sensor is equal to or higher than a second temperature higher than the first temperature.

[0027] At this time, the apparatus may further include an air pressure regulator that maintains the internal pressure of the tank constant when the inside of the tank is pressurized by the pressure pump.

[0028] In this case, the position where the supply passage is connected to the tank may be located below the water surface of the heat transfer fluid stored inside the tank, and the position where the return passage is connected to the tank may be located below the water surface of the heat transfer fluid stored inside the tank.

[0029] In this case, the tank may further include a pump connected to the supply passage or the return passage to generate a fluid flow such that the heat transfer fluid stored inside the tank returns to the tank via the supply passage, the object to be cooled, and the return passage in that order; and a temperature regulator that maintains the temperature of the heat transfer fluid provided to the object to be cooled at a predetermined temperature. Effect of the Invention

[0030] The heat transfer fluid supply system according to an embodiment of the present invention can use the heat transfer fluid, which has a low viscosity at low temperature, at a high vaporization point by pressurizing the heat transfer fluid through a pressure pump.

[0031] In addition, the heat transfer fluid supply system according to one embodiment of the present invention can be used by increasing the vaporization point of the heat transfer fluid, which has low viscosity at low temperatures, by increasing the pressure inside the tank due to the thermal expansion of the heat transfer fluid passing through the object to be cooled.

[0032] It should be understood that the effects of the present invention are not limited to the effects described above, but include all effects that can be inferred from the configuration of the invention described in the description of the present invention or the claims. [Brief description of the drawings]

[0033] [Figure 1] 1 is a schematic diagram of a heat transfer fluid supply system according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram illustrating a control unit of a heat transfer fluid supply system according to an embodiment of the present invention. [Diagram 3] 2 is a view showing a water surface of a tank of a heat transfer fluid supply system according to an embodiment of the present invention. [Figure 4] 4 is a view showing the water surface of a tank of a heat transfer fluid supply system according to an embodiment of the present invention. [Diagram 5] 4 is a graph showing the viscosity of a heat transfer fluid according to temperature used in a heat transfer fluid supply system in accordance with an embodiment of the present invention; [Figure 6]4 is a graph showing pressure depending on vaporization point of a heat transfer fluid used in a heat transfer fluid supply system according to an embodiment of the present invention. [Figure 7] 2 is a graph showing pressure over time for a pump of a conventional heat transfer fluid supply system. [Figure 8] 4 is a graph showing pressure over time of a pump of a heat transfer fluid supply system according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily carry out the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention, parts not related to the description are omitted in the drawings, and the same reference numerals are used throughout the specification to refer to the same or similar components.

[0035] The words and terms used in this specification and the claims should not be interpreted in a limited manner based on their ordinary or dictionary meaning, but should be interpreted in a meaning and concept that corresponds to the technical idea of ​​the present invention in accordance with the principle that the inventor can define the terms and concepts in order to best describe his / her invention.

[0036] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings correspond to preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore the relevant configurations may have various equivalents and modifications that replace them at the time of filing of the present invention.

[0037] In this specification, the terms "comprise" or "have" are intended to describe the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0038] A certain component being "in front," "in back," "above," or "below" another component means not only that it is immediately adjacent to the other component and is disposed "in front," "in back," "above," or "below," unless there are special circumstances, but also includes the case where another component is disposed between them. Furthermore, a certain component being "connected" to another component means not only that they are directly connected to each other, but also that they are indirectly connected to each other, unless there are special circumstances.

[0039] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of a heat transfer fluid supply system according to the present invention will now be described with reference to the accompanying drawings.

[0040] Fig. 1 is a schematic diagram of a heat transfer fluid supply system according to an embodiment of the present invention. Fig. 2 is a block diagram showing a control unit of the heat transfer fluid supply system according to an embodiment of the present invention. Fig. 3 is a diagram showing a first water surface of a tank of the heat transfer fluid supply system according to an embodiment of the present invention. Fig. 4 is a diagram showing a second water surface of a tank of the heat transfer fluid supply system according to an embodiment of the present invention.

[0041] At this time, Figures 1, 3 and 4 are merely schematic diagrams of one embodiment of the present invention, and the components illustrated in Figures 1, 3 and 4 do not necessarily have to have the same shape or be arranged in the same position as those illustrated in Figures 1, 3 and 4.

[0042] As shown in FIG. 1, a heat transfer fluid supply system 1 according to one embodiment of the present invention includes a tank 10, a cooled body 20, a pump 40, a cooled body heater 50, a pressure pump 60, a pressure sensor 70, a pressure control valve 80 and a control unit 90.

[0043] The heat transfer fluid supply system 1 is a system that supplies a heat transfer fluid for transferring heat to or receiving heat from a specific position in equipment. There is no limit to the equipment in which the heat transfer fluid supply system 1 can be installed. For example, the heat transfer fluid can be supplied to a test equipment for testing semiconductor devices.

[0044] Hereinafter, the heat transfer fluid supply system 1 will be described as a heat transfer fluid supply system 1 provided in a test equipment to supply a heat transfer fluid to a prober chuck that supports a semiconductor device among various equipment. That is, in this embodiment, the object to be cooled 20 that is to be cooled or heated by the heat transfer fluid will be described as a prober chuck.

[0045] In this case, the heat transfer fluid refers to a liquid that indirectly cools or heats an object to be cooled or heated through a heat exchanger or the like.

[0046] A variety of known materials can be used as the heat transfer fluid. However, it is preferable that the heat transfer fluid used for the effect of the present invention has low viscosity at low temperatures. For example, HT135, HT170, HFE7500, and HFE7200 can be used as the heat transfer fluid.

[0047] A space is formed inside the tank 10. There is no limitation on the shape of the tank 10 as long as a space can be formed inside the tank 10. At this time, a heat transfer fluid is stored in the internal space of the tank 10.

[0048] The heat transfer fluid is stored in the tank 10 so that the tank 10 is not filled to capacity. That is, the heat transfer fluid is located in the lower part of the tank 10 due to its density, and a space is formed above the heat transfer fluid.

[0049] Meanwhile, the tank 10 is preferably formed to extend in the vertical direction. That is, the cross-sectional area of ​​the tank 10 perpendicular to the vertical direction is preferably constant. In this case, the volume of the heat transfer fluid stored inside the tank 10 is proportional to the height of the heat transfer fluid. In this embodiment, the tank 10 is described as extending in the vertical direction.

[0050] 3 and 4, the tank 10 may be provided with a transparent window 11 extending in the vertical direction of the tank 10, through which the volume of the heat transfer fluid stored inside the tank 10 can be visually confirmed. This allows the user to visually determine whether the heat transfer fluid is expanding or compressing.

[0051] The internal space of the tank 10 is connected to the object to be cooled 20. At this time, a heat transfer passage is formed inside the object to be cooled 20 for heat exchange. Through this, the heat transfer fluid can absorb the heat of the object to be cooled 20 while passing through the heat transfer passage of the object to be cooled 20 during the inspection of the semiconductor device.

[0052] As shown in FIG. 1, a supply passage L1 connects one side of the tank 10 to one side of the heat transfer passage of the body to be cooled 20, and a recovery passage L2 connects the other side of the tank 10 to the other side of the body to be cooled 20, so that the internal space of the tank 10 and the heat transfer passage of the body to be cooled 20 can be connected.

[0053] As long as the heat transfer fluid can travel back and forth between the tank 10 and the object 20 to be cooled, there are no limitations on the shape or materials used to form the supply flow path L1 and the recovery flow path L2.

[0054] 1, the supply flow path L1 or the recovery flow path L2 is connected to a pump 40. In this embodiment, the pump 40 is connected to the supply flow path L1.

[0055] The pump 40 creates a fluid flow such that the heat transfer fluid stored inside the tank 10 returns to the tank 10 via the supply flow path L1, the object to be cooled 20, and the recovery flow path L2 in this order.

[0056] A temperature regulator 41 is installed in the supply flow path L1 between the pump 40 and the object to be cooled 20. The temperature regulator 41 maintains the temperature of the heat transfer fluid provided to the object to be cooled 20 at a predetermined temperature. That is, the temperature regulator 41 may be a heater if the temperature of the heat transfer fluid is lower than the predetermined temperature, and may be a cooler if the temperature of the heat transfer fluid is higher than the predetermined temperature. The temperature regulator 41 may be any of various known devices as long as it can increase or decrease the temperature of the heat transfer fluid.

[0057] At this time, the positions where the supply passage L1 and the recovery passage L2 are connected to the tank 10 are located below the water surface of the heat transfer fluid stored inside the tank 10. Accordingly, the heat transfer fluid can be continuously circulated during the process of circulating the heat transfer fluid by the pump 40.

[0058] In particular, since the supply passage L1 and the recovery passage L2 are connected to the tank 10 so as to be located below the water surface of the heat transfer fluid, even if the internal pressure of the tank 10 is adjusted through the control unit 90 described below, the same pressure can be maintained along the path through which the heat transfer fluid moves.

[0059] The control unit 90 controls the internal pressure of the tank 10. Through this, the pressure of the heat transfer fluid stored inside the tank 10 is increased, thereby increasing the vaporization point of the heat transfer fluid, thereby preventing the problem of heat not being continuously transferred through the heat transfer fluid due to vaporization even when a heat transfer fluid with low viscosity at low temperature is used. In addition, cavitation due to low pressure near the pump 40 can be prevented.

[0060] 1, a heater 50 for the object to be cooled is connected to the object to be cooled 20. As shown in FIG. 2, the heater 50 for the object to be cooled is controlled by a control unit 90. The heater 50 for the object to be cooled heats the object to be cooled 20.

[0061] At this time, the control unit 90 controls the pump 40 to circulate the heat transfer fluid to the object to be cooled 20, so that the object to be cooled 20 can maintain an appropriate temperature. If an object to be cooled heater 50 is provided, the heat transfer fluid is used to cool the object to be cooled 20 so that the object to be cooled 20 does not become overheated.

[0062] At this time, the temperature of the heat transfer fluid passing through the object to be cooled 20 rises due to the heat absorbed from the object to be cooled 20. As a result, the heat transfer fluid is thermally expanded, the internal pressure of the tank 10 increases, and the total pressure of the circulating heat transfer fluid increases.

[0063] 3, before the heat transfer fluid stored inside the tank 10 passes through the object to be cooled 20, a space is formed in the upper part of the tank 10. At this time, since the internal volume of the tank 10 is proportional to the height, the height of the upper space of the tank 10 can be expressed as h1.

[0064] When the control unit 90 heats the object 20 to be cooled through the object heater 50, the temperature of the heat transfer fluid passing through the object 20 to be cooled increases, and the heat transfer fluid thermally expands. That is, as shown in Fig. 4, the size of the heat transfer fluid increases, and the height of the upper space inside the tank 10 decreases to h2.

[0065] Meanwhile, as shown in FIG. 1, the tank 10 is provided with a pressure sensor 70. The pressure sensor 70 can measure the internal pressure of the tank 10. The pressure measured by the pressure sensor 70 is preferably the air pressure in the space above the heat transfer fluid inside the tank 10. However, the present invention is not limited to this, and the pressure of the heat transfer fluid may be measured directly. In this case, the control unit 90 can receive pressure information measured by the pressure sensor 70.

[0066] 1, a pressure control valve 80 is installed in the tank 10. The pressure control valve 80 is provided on the upper part of the tank 10 so that the internal space of the tank 10 can communicate with the outside of the tank 10. When the pressure control valve 80 is opened, air located at the upper part of the interior of the tank 10 can escape to the outside or outside air can enter the inside of the tank 10.

[0067] The pressure control valve 80 may be a solenoid valve connected to the control unit 90 and electronically controlled to open and close by the control unit 90. When the pressure measured by the pressure sensor 70 exceeds a predetermined pressure, the control unit 90 opens the pressure control valve 80 to lower the internal pressure of the tank 10 and adjust the internal pressure of the tank 10 to an appropriate pressure.

[0068] In particular, the control unit 90 can control the internal pressure of the tank 10 to a set pressure by controlling the degree and time of opening and closing of the pressure control valve 80 to prevent an increase in the internal pressure of the tank 10 caused by an increase in the temperature of the heat transfer fluid passing through the cooled body 20 and the expansion of the heat transfer fluid.

[0069] However, the standard by which the control unit 90 controls the pressure control valve 80 is not determined only by the pressure collected from the pressure sensor 70. A detailed description of this will be given later together with the description of the temperature sensor 30.

[0070] 2, the pressure pump 60 connected to the tank 10 is connected to the control unit 90. The control unit 90 can supply dry air into the tank 10 through the pressure pump 60.

[0071] The control unit 90 can control the amount of dry air provided to the inside of the tank 10 by controlling the pressure pump 60. The control unit 90 may use a method of controlling the output of the pressure pump 60 itself, or may use a pressure pump valve 61, which will be described later.

[0072] It is preferable that the pressure pump 60 is connected to the tank 10 at a position above the water surface of the heat transfer fluid stored inside the tank 10. This prevents air bubbles from forming inside the heat transfer fluid or obstructing the flow of the heat transfer fluid even if dry air flows into the tank 10.

[0073] 1, the pressure pump 60 may be connected to the tank 10 through a pressure pump valve 61. The pressure pump valve 61 opens and closes a flow path connecting the pressure pump 60 and the tank 10.

[0074] Various known valves can be used as the pressure pump valve 61. In this embodiment, the pressure pump valve 61 is a solenoid valve connected to the control unit 90 and electronically controlled to open and close.

[0075] The control unit 90 can adjust the amount of dry air that the pressure pump 60 provides to the tank 10 by controlling the degree and time of opening and closing the pressure pump valve 61. That is, the control unit 90 can adjust the internal pressure of the tank 10 through the pressure pump valve 61.

[0076] At this time, it is preferable that the pressure pump 60 is a pump that provides dry air at a constant pressure because the pressure pump 60 must provide a constant pressure in order for the control unit 90 to control the pressure pump valve 61 to control the internal pressure of the tank 10.

[0077] In particular, the pressure pump 60 that provides dry air at a constant pressure may be an air pressure facility installed in a factory in which the heat transfer fluid supply system 1 according to an embodiment of the present invention is installed. That is, the tank 10 can easily receive a supply of dry air that can be supplied to the inside of the tank 10 by being connected to an air pressure facility installed in many factories.

[0078] The control unit 90 can add a predetermined pressure to the internal pressure of the tank 10 through the pressure pump 60. To explain this in more detail, as shown in Fig. 4, a predetermined space is formed in the upper part of the tank 10 even before dry air is supplied to the inside of the tank 10 by the pressure pump 60. At this time, since the internal volume of the tank 10 is proportional to the height, the height of the upper space of the tank 10 can be expressed as h2.

[0079] When the control unit 90 drives the pressure pump 60 or opens the pressure pump valve 61 connected to the pressure pump 60, dry air is supplied into the tank 10 to pressurize the heat transfer fluid. That is, as shown in Fig. 3, the volume of the heat transfer fluid decreases and the size of the upper space inside the tank 10 increases to h1.

[0080] In summary, the control unit 90 can adjust the pressure of the heat transfer fluid using the pressure control valve 80 or the pressure pump 60, or using both the pressure control valve 80 and the pressure pump 60. In this case, the pressure added by the control unit 90 to pressurize the heat transfer fluid can be 0.4 bar to 0.6 bar, and preferably 0.5 bar.

[0081] Meanwhile, as shown in FIG. 1, the heat transfer fluid supply system 1 according to the embodiment of the present invention may further include a temperature sensor 30 provided in the tank 10 .

[0082] The temperature sensor 30 measures the temperature of the heat transfer fluid flowing into the tank 10. The temperature sensor 30 may be any of various known temperature sensors as long as it can measure the temperature of the fluid. There is no limitation on the manner or position at which the temperature sensor 30 is installed in the tank 10.

[0083] The temperature sensor 30 measures the temperature of the heat transfer fluid that has increased in temperature by absorbing heat from the object to be cooled 20 while passing through the object to be cooled 20. In other words, the heat transfer fluid whose temperature is measured by the temperature sensor 30 is not a heat transfer fluid that is controlled to a predetermined temperature in order to be transferred to the object to be cooled 20.

[0084] The control unit 90 can control the internal pressure of the tank 10 based on the temperature information of the heat transfer fluid measured by the temperature sensor 30. Hereinafter, a method in which the control unit 90 controls the internal pressure of the tank 10 using both the pressure pump valve 61 and the pressure control valve 80 based on the temperature information of the heat transfer fluid will be described. At this time, the pressure pump 60 is a pressure pump 60 that provides dry air at a constant pressure and can control the amount of dry air provided by using the pressure pump valve 61 as described above.

[0085] However, the following description is merely an example of the operation of the control unit 90 that controls the internal pressure of the tank 10 using both the pressure pump valve 61 and the pressure control valve 80, and the heat transfer fluid supply system 1 according to one embodiment of the present invention does not necessarily have to operate in the manner described below.

[0086] The control unit 90 can control the pressure pump valve 61 and the pressure adjustment valve 80 according to a temperature range based on the temperature measured by the temperature sensor 30, that is, a first temperature and a second temperature higher than the first temperature.

[0087] At this time, the first temperature and the second temperature can be set differently depending on the type of the heat transfer fluid. For example, when the heat transfer fluid is HFE7500, it is preferable to set the first temperature to 60 degrees Celsius and the second temperature to 100 degrees Celsius.

[0088] If the temperature information measured by the temperature sensor 30 is less than the first temperature, the control unit 90 closes the pressure pump valve 61 and opens the pressure control valve, so that the internal space of the tank 10 becomes fluidly connected to the outside, and the internal pressure of the tank 10 is maintained at 1 atmosphere.

[0089] In other words, the internal pressure of the tank 10 is maintained at 1 atmosphere even if there is thermal expansion due to the temperature of the heat transfer fluid, and the heat transfer fluid circulates through the heat transfer fluid supply system 1 .

[0090] When the temperature of the heat transfer fluid passing through the object to be cooled 20 rises to or exceeds the first temperature, the control unit 90 closes the pressure control valve 80. As a result, the heat transfer fluid that absorbs heat while passing through the object to be cooled 20 thermally expands, and the internal pressure of the tank 10 gradually increases.

[0091] In particular, as the temperature of the heat transfer fluid gradually increases, the volume of the heat transfer fluid also gradually increases due to thermal expansion, which prevents the tank 10 from being damaged due to stress caused by a sudden change in internal pressure. In addition, the internal pressure of the tank 10 is controlled using the thermal expansion or contraction of the heat transfer fluid, which prevents noise caused by air purge.

[0092] When the temperature of the heat transfer fluid passing through the object to be cooled 20 is further increased to equal to or higher than the second temperature, the control unit 90 opens the pressure pump valve 61. Accordingly, the inside of the tank 10 is maintained in a pressurized state with a predetermined pressure added by the pressure pump 60. In this embodiment, 0.5 atmospheres are added by the pressure pump 60, and the internal pressure of the tank 10 is maintained at 1.5 atmospheres.

[0093] At this time, the pressure pump 60 may be provided with an air pressure regulator 62. The air pressure regulator 62 adjusts the pressure of the dry air provided by the pressure pump 60 to the inside of the tank 10 so that the internal pressure of the tank 10 can be kept constant. The air pressure regulator 62 may be any of various known devices.

[0094] By providing the air pressure regulator 62, the internal pressure of the tank 10 can be maintained constant with a predetermined pressure above 1 atmosphere being added by the pressure pump 60 even if there is thermal expansion of the heat transfer fluid.

[0095] The effects of the heat transfer fluid supply system 1 according to one embodiment of the present invention will be described below with reference to FIGS.

[0096] Fig. 5 is a graph showing the viscosity of a heat transfer fluid according to temperature used in a heat transfer fluid supply system according to an embodiment of the present invention. Fig. 6 is a graph showing the pressure according to the vaporization point of a heat transfer fluid used in a heat transfer fluid supply system according to an embodiment of the present invention. Fig. 7 is a graph showing the pressure of a heat transfer fluid according to time used in a conventional heat transfer fluid supply system. Fig. 8 is a graph showing the pressure of a heat transfer fluid according to time used in a heat transfer fluid supply system according to an embodiment of the present invention.

[0097] 5, it can be seen that the viscosity of a heat transfer fluid increases as the temperature decreases, regardless of the type of the heat transfer fluid. In other words, when circulating through the supply passage L1, the object to be cooled 20, and the recovery passage L2 at a low temperature, not only does the pressure on the piping and the pump 40 increase, possibly causing an overload on the pump 40, but the convection effect of the heat transfer fluid decreases, thereby reducing the heat exchange performance of the heat transfer fluid.

[0098] However, if a heat transfer fluid with low viscosity at low temperature is used to prevent this, there is a problem that the formation of a fluid flow may be restricted due to the low vaporization point.

[0099] At this time, as shown in Figure 6, increasing the pressure of the heat transfer fluid from P1 to P2 increases the vaporization point. More specifically, increasing the pressure by 0.5 bar increases the vaporization point by more than 10 degrees.

[0100] Accordingly, stability problems and fluid fluidity constraints can be reduced even when using a heat transfer fluid that is low in viscosity at low temperatures. That is, in the conventional case, as shown in Fig. 7, not only does a difference occur between the target temperature SP and the actual measured temperature PV of the object to be cooled 20 as the heat transfer fluid circulates, but the pump pressure PUMP_P does not have a constant value, so that it can be confirmed that the fluid fluidity is unstable.

[0101] On the other hand, in this embodiment, as shown in FIG. 8, since the difference between the target temperature SP of the cooled object 20 and the actual measured temperature PV is small, the temperature of the cooled object 20 can be controlled more precisely, and the pump pressure PUMP_P can be maintained at a more constant value, thereby confirming that the fluid fluidity is stable.

[0102] As described above, the preferred embodiments of the present invention have been described in detail, and it will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or scope of the present invention. Therefore, the above-described embodiments should be considered as illustrative rather than restrictive, and the present invention is not limited to the above description, and may be modified within the scope of the appended claims and their equivalents. [Industrial Applicability]

[0103] The present invention is applicable to an apparatus for inspecting semiconductor devices.

Claims

1. a body to be cooled in which a heat transfer flow path is formed through which a heat transfer fluid passes; a tank having a space formed therein for storing the heat transfer fluid; a supply passageway connecting the tank and one side of the heat transfer passageway; a return passage connecting the tank with the other side of the heat transfer passage; and a control for controlling a pressure inside the tank.

2. a pressure pump for supplying dry air to the tank; The heat transfer fluid supply system according to claim 1 , wherein the control unit is capable of adding a predetermined pressure to the internal pressure of the tank through the pressure pump.

3. The heat transfer fluid supply system according to claim 2 , further comprising: a pressure pump valve provided in the tank so that an inner space of the tank can be communicated with the pressure pump.

4. The heat transfer fluid supply system according to claim 3 , wherein the control unit controls the internal pressure of the tank by controlling opening and closing of the pressure pump valve.

5. The heat transfer fluid supply system of claim 3 , wherein the booster pump constantly provides a predetermined pressure.

6. 3. The heat transfer fluid supply system of claim 2, wherein the pressure pump is connected to the tank at a position above a water level of the heat transfer fluid stored inside the tank.

7. The heat transfer fluid supply system of claim 2 , wherein the predetermined pressure is between 0.4 bar and 0.6 bar.

8. A heater for heating the object to be cooled; The heat transfer fluid supply system according to claim 1 , wherein the control unit controls the temperature of the object to be cooled through the heat transfer fluid and the object heater.

9. The heat transfer fluid supply system according to claim 8 , further comprising: a pressure control valve provided in the tank to allow communication between an inner space of the tank and the outside of the tank.

10. The heat transfer fluid supply system according to claim 9 , wherein the control unit controls the internal pressure of the tank by controlling opening and closing of the pressure regulating valve.

11. The heat transfer fluid supply system according to claim 10 , wherein the control unit controls an internal pressure added to the tank by thermal expansion of the heat transfer fluid passing through the cooled body.

12. a pressure sensor provided in the tank for measuring an internal pressure of the tank; The heat transfer fluid supply system of claim 10 , wherein the control unit controls the internal pressure of the tank by controlling opening and closing of the pressure regulating valve based on pressure information measured by the pressure sensor.

13. a temperature sensor provided in the tank for measuring the temperature of the heat transfer fluid stored in the tank; The heat transfer fluid supply system of claim 10 , wherein the control unit controls the internal pressure of the tank by controlling opening and closing of the pressure regulating valve based on temperature information measured by the temperature sensor.

14. a pressure pump for supplying dry air to the tank to provide a constant predetermined pressure; and a pressure pump valve provided in the tank so that an internal space of the tank and the pressure pump can communicate with each other; The heat transfer fluid supply system of claim 13 , wherein the control unit further controls the opening and closing of the pressure pump valve to control the internal pressure of the tank.

15. The heat transfer fluid supply system of claim 14 , wherein the control unit closes the pressure pump valve and opens the pressure control valve when the temperature information measured by the temperature sensor is lower than a first temperature.

16. 15. The heat transfer fluid supply system of claim 14, wherein the control unit closes the pressure pump valve and the pressure control valve when temperature information measured through the temperature sensor is equal to or higher than a first temperature, so that the internal pressure of the tank gradually increases due to thermal expansion of the heat transfer fluid passing through the cooled body.

17. The heat transfer fluid supply system of claim 16 , wherein the control unit opens the pressure pump valve when the temperature information measured by the temperature sensor is equal to or higher than a second temperature higher than the first temperature.

18. 18. The heat transfer fluid supply system of claim 17, further comprising: an air pressure regulator that maintains a constant internal pressure of the tank when the inside of the tank is pressurized by the pressure pump.

19. The supply passage is connected to the tank at a position below the water surface of the heat transfer fluid stored in the tank, The heat transfer fluid supply system according to claim 1 , wherein the return passage is connected to the tank at a position below a water surface of the heat transfer fluid stored inside the tank.

20. A pump connected to the supply passage or the recovery passage to generate a flow of fluid such that the heat transfer fluid stored inside the tank returns to the tank via the supply passage, the object to be cooled, and the recovery passage in this order; and The heat transfer fluid supply system of claim 1 , further comprising: a temperature regulator that maintains the temperature of the heat transfer fluid provided at the body to be cooled at a predetermined temperature.

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