KR100528334B1 - Baking system - Google Patents

Abstract

A bake system is disclosed. The disclosed bake system includes a heat pipe having a baking wafer loaded on an upper surface thereof, filled with a predetermined amount of working fluid therein, and having a wick for supplying the working fluid to the side and the ceiling, and heating of the working fluid. An auxiliary cooling unit comprising a heater used to heat the upper surface through the heat pipe, a liquid refrigerant to be exchanged with the working fluid of the heat pipe through circulation, and a heat pipe having a wick formed therein, and the working fluid and the It provides a baking system for the circulation of the liquid refrigerant is provided with a connection pipe for connecting the heat pipe and the auxiliary cooling unit and an intermittent means for controlling the fluid flowing through the connection pipe in the connection pipe.

Description

Baking system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a baking system used for semiconductor manufacturing, and more particularly to a baking system provided as a cooling means using a heat pipe.

The photolithography process in the manufacturing process of the semiconductor device is performed after the process of coating the photoresist film on the wafer, the pre-bake process of baking the applied photoresist film before exposure, and the exposure process for designing the photoresist film in a predetermined pattern. Post Exposure Bake process is included.

In the photographic process, the baking temperature depends on the type of photoresist film used and the type of process. For example, baking may be performed at 150 degreeC, and you may need to carry out at 90 degreeC depending on a situation. Because of this, today's widely used baking equipment has a heating and cooling system to adjust the baking temperature to suit the situation.

1 to 3 are cross-sectional views showing a cooling system of the baking equipment according to the prior art (hereinafter referred to as a conventional cooling system).

First, the conventional cooling system shown in FIG. 1, as described in Korean Patent No. 2001-0015371, installs cooling medium passages 56 and 57 through which a coolant can flow in a plate 54, thereby providing a coolant. The heating plate 51 is cooled by the circulating method. In Fig. 1, reference numerals 52 and 53 are heater and lift pins, respectively, and 55 is a cooling plate. Reference numerals 60 and 61 are supply paths of the cooling medium, 62 and 63 are switching valves, and 64 to 69 are drains, temperature sensors, unit controllers, thermostats, solenoid valves, and power supplies, respectively. Also, reference numeral 80 is a system controller for controlling the operation of the entire system.

Next, the conventional cooling system shown in FIG. 2 is described in Japanese Patent Laid-Open No. 11-227512 (Publication No. 2001-118789A), and a plurality of nozzles 74 are installed below the hot plate 70 corresponding to the baking plate. It is. The fluid is injected into the hot plate 70 through the furnace 74 to cool the hot plate 70. In the drawings, reference numerals 71, 83, 85, 87, 93 and 96 are a heater, a guide, an inner case, a spot ring, a cooling plate and a black plate, respectively.

Subsequently, the conventional cooling system shown in FIG. 3 is described in Korean Patent No. 2001-0051755, and the cooling device 30 includes a cooling plate 99 in which the Peltier element 101 is incorporated. The Peltier element 101 adjusts the cooling plate 99 to a predetermined temperature. In addition, the power supply control unit 102 for supplying power to the Peltier element 101, the temperature control unit 103 for controlling the temperature of the Peltier element 101, and the PID control parameter changing unit 105 are provided to the cooling device 30. It is provided. In addition, a flow path 111 for dissipating heat generated from the Peltier element 101 is provided. In the drawings, reference numerals 90, 91, and 92 are lift pins for raising the wafer W, through holes, and proximity pins for supporting the wafer W, respectively, and 104 are temperature sensors for sensing the temperature of the cooling plate 99. .

In such a conventional cooling system, although there are advantages in its own way, since the cooling is performed locally, the temperature variation for each region of the baking plate is large. In other words, the entire baking plate is not cooled uniformly. In addition, it takes a long time for cooling to begin to achieve the desired uniform temperature distribution. These are one of the factors that greatly reduce the productivity of the semiconductor device.

As these problems emerge with conventional cooling systems, one of the alternatives is to install multiple bake plates set at various temperatures. This method can solve the problem of cooling time, but because a plurality of bake plates are provided in one spinner, the spinner is enlarged, which is not a preferable method.

The technical problem to be achieved by the present invention is to improve the above-described problems of the prior art, to provide a baking system that can cool the entire area of the upper surface of the hot plate uniformly, as well as significantly reduce the cooling time.

In order to achieve the above technical problem, the present invention is a heat pipe with a baking wafer loaded on the upper surface, a predetermined amount of working fluid is filled therein, and a wick for supplying the working fluid to the side and the ceiling is formed. And an auxiliary cooling unit having a heater used to heat the upper surface through the heating of the working fluid, and a liquid refrigerant to be exchanged with the working fluid of the heat pipe through circulation, and the working fluid and the liquid refrigerant. It provides a baking system for the circulation is provided with a connection pipe for connecting the heat pipe and the auxiliary cooling unit and the connection means for the control of the fluid flowing through the connection pipe to the connection pipe.

According to an embodiment of the present invention, the connecting pipes are first and second flow paths connecting the same side of the heat pipe and the same side of the auxiliary cooling unit.

The auxiliary cooling unit may further include a refrigerant storage tank in which the liquid refrigerant is stored, a cooling device provided in the refrigerant storage tank for cooling the working fluid introduced therein, and pressurizing means for pressurizing the liquid refrigerant during cooling of the upper surface. do. In this case, since the wick is formed on the inner surface of the refrigerant storage tank, it is preferable that the auxiliary cooling unit has a heat pipe configuration.

According to another embodiment of the present invention, the connecting pipe is a first connecting pipe connecting one side of the heat pipe and one side of the auxiliary cooling unit and a second connecting pipe connecting the other side of the heat pipe and the other side of the auxiliary cooling unit. It consists of.

In addition, the auxiliary cooling unit includes a refrigerant storage tank in which the liquid refrigerant is stored and a cooling device provided in the first refrigerant storage tank for cooling of the working fluid flowing in.

The control means is a pump or a valve.

An auxiliary heater for heating a fluid flowing through the connection pipe is provided in the connection pipe between the other side of the heat pipe and the auxiliary cooling unit. In addition, an auxiliary heater for heating the fluid supplied to the heat pipe to the first refrigerant storage tank is provided.

In order to achieve the above technical problem, the present invention is also a heat-baking wafer is loaded on the upper surface, a predetermined amount of working fluid is filled therein, a wick (wick) for the supply of the working fluid is provided on the side and ceiling A pipe, a heater used to heat the upper surface through heating of the working fluid, one end of which is connected to one side of the heat pipe through which the working fluid flows out, and the other end of the heat into which the outflowing working fluid flows in A connecting system connected to the other side of the pipe and a cooling system for cooling the working fluid flowing through the connecting pipe to the connecting pipe and an intermittent means for controlling the operating fluid is provided.

Here, the cooling device is provided to surround a portion of the connection pipe.

In addition, the control means is a pump or a valve provided between the one side of the heat pipe and the cooling device, and the other side of the heat pipe and the cooling device, respectively.

Using the present invention, temperature stabilization can be achieved by uniformly cooling the entire area of the hot plate in a short time of about tens of seconds. In addition, it is possible to reduce the heating time of the hot plate by using the auxiliary heater provided, the productivity is much higher than the conventional.

Hereinafter, a baking system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of layers or regions illustrated in the drawings are exaggerated for clarity.

<First Embodiment>

The bake system according to the first embodiment of the present invention has an auxiliary cooling unit P2 (hereinafter referred to as an auxiliary cooling unit) composed of a main body P1 and a heat pipe connected thereto as shown in FIG. 4. The main body P1 includes a heat pipe 100 and a heater 102 provided to contact the bottom surface thereof. The auxiliary cooling unit P2 is provided below the first refrigerant storage tank 106 partially filled with the liquid refrigerant 104b and the first refrigerant storage tank 106 to cool the liquid refrigerant 104b. It is provided on the 110 and the first refrigerant storage tank 106 includes a pressurizing means 109 for forcibly circulating the liquid refrigerant (104b) to the heat pipe (100). Since the wick is formed on the inner surface of the first refrigerant storage tank 106, in particular, the inner side and the ceiling, the high temperature working fluid introduced into the first refrigerant storage tank 106 receives the capillary force from the wick and thus the first refrigerant storage tank ( It evaporates while moving up to the ceiling along the sides of 106). In this process, the high temperature working fluid introduced into the first refrigerant storage tank 106 is cooled. As such, since the first refrigerant storage tank 106 is equivalent to the heat pipe, the auxiliary cooling unit P2 may be regarded as a heat pipe. The pressurizing means 109 thermally heats steam existing above the liquid refrigerant of the first refrigerant storage tank 106 to pressurize the liquid refrigerant stored in the first refrigerant storage tank 106, and the first refrigerant storage tank. It is desirable not to cause physical deformation of 106.

When the baking process is performed, as shown in the figure, the wafer W is loaded on the upper surface S1 of the heat pipe 100, and the upper surface S1 of the heat pipe 100 is a hot plate surface and has a predetermined temperature. For example, it heats at 100 to 150 degreeC. The heat pipe 100 serves to cool the upper surface S1 heated in the baking process to a predetermined temperature after the baking process is completed and the wafer W is removed from the upper surface S1.

For this role of the heat pipe 100, a predetermined amount of working fluid 104a is filled in the heat pipe 100. And a wick (not shown) is formed from the inner side of the heat pipe 100 to the center of the ceiling.

The working fluid 104a serves to heat the upper surface S1 by transferring heat transferred from the heater 102 to the upper surface S1 of the heat pipe 100 in the baking process. In the baking process, the working fluid 104a is evaporated into the space 112 above the working fluid 104a by the heat transferred from the heater 102 to contact the ceiling of the heat pipe 100. Top surface S1 of 100 is heated.

Meanwhile, in the process of cooling the hot plate surface, that is, the upper surface S1 of the heat pipe 100, the working fluid 104a is supplied to the ceiling of the heat pipe 100 along the wick and evaporated. Through the upper surface (S1) is cooled. At this time, since the wick is evenly formed in the entire ceiling area of the heat pipe 100, the working fluid 104a is uniformly supplied to the entire ceiling area of the heat pipe 100. In addition, since the working fluid 104a is capillary by the wick, the working fluid 104a is rapidly supplied to the entire ceiling area of the heat pipe 100 during the cooling process. Accordingly, the upper surface S1 of the heat pipe 100 is uniformly cooled in the entire area in a short time. The steam generated in this cooling process is brought back into the working fluid 104a through the process of condensing while contacting the working fluid 104a having a lower temperature through the cavity 112.

The working fluid 104a is preferably water (distilled water), but other fluids such as acetone or methyl may be used.

On the other hand, when replacing the working fluid 104a with a lower temperature fluid in the process of cooling the upper surface (S1) of the heat pipe 100, the cooling efficiency of the heat pipe 100 is increased. The liquid refrigerant 104b filled in the first refrigerant storage tag 106 of the auxiliary cooling unit P1 'is prepared for this purpose. The liquid refrigerant 104b of the first refrigerant storage tank 106 is preferably maintained at a lower temperature than the working fluid 104a.

In the process of cooling the upper surface S1 of the heat pipe 100, the upper surface between the auxiliary cooling unit P1 ′ and the heat pipe 100 to increase the cooling efficiency of the heat pipe 100 as described above. The fluid circulation is made until the temperature of S1 is cooled to the desired temperature.

Specifically, the first and second flow paths L1 and L2 for fluid circulation are provided between the heat pipe 100 and the auxiliary cooling unit P1, and the first and second flow paths L1 and L2 are provided above. The valve 108 is provided to control the flow of the fluid so that the fluid can be circulated only during the cooling process. Valve 108 may be replaced with a pump.

As the cooling of the upper surface S1 of the heat pipe 100 starts, the valve 108 is opened, and at the same time, the liquid refrigerant 104b is applied by the pressurizing means 109 of the auxiliary cooling unit P1 ', for example, a Peltier element. Is pressurized. As a result, a part of the liquid refrigerant 104b is supplied to the heat pipe 100 through the second flow path L2, and the working fluid 104a of the heat pipe 100 is transferred to the first pipe through the first flow path L1. It is introduced into the refrigerant storage tank 106. This fluid circulation is carried out continuously or periodically until the temperature of the upper surface S1 of the heat pipe 100 is lowered to a predetermined temperature, for example 100 ° C. Liquid refrigerant stored in the first refrigerant storage tank 106 while the heated working fluid 104a of the heat pipe 100 flows into the first refrigerant storage tank 106 of the auxiliary cooling unit P1 ′ in the fluid circulation process. The temperature of the 104b is increased, the temperature of the liquid refrigerant 104b is kept constant by the first cooling device 110 provided below the first refrigerant storage tank 106.

Second Embodiment

Referring to FIG. 5, the bake system according to the second embodiment of the present invention includes a second refrigerant storage tank 120 connected to the heat pipe 100. One side of the heat pipe 100 and one side of the second refrigerant storage tank 120 is connected to the first connecting pipe 126, each other side is connected to the second connecting pipe (128). The liquid refrigerant 104a flows from the heat pipe 100 to the second refrigerant storage tank 120 through the first connection pipe 126. The liquid refrigerant 104a introduced into the second refrigerant storage tank 120 is cooled to a predetermined temperature, for example, 23 ° C., and then supplied to the heat pipe 100 through the second connection pipe 128.

Fluid circulation between the heat pipe 100 and the second refrigerant storage tank 120 is preferably stopped during the baking process and opened while cooling the upper surface S1 of the heat pipe 100. To this end, the first refrigerant control means 126a is installed in the first connection pipe 126, and the second refrigerant control means 128a is installed in the second connection pipe 128, respectively. The first refrigerant control means 126a is preferably an automated pump, but may be a valve. Preferably, the second refrigerant control means 128a is a valve, but a pump capable of automatic or manual operation may be used.

Meanwhile, as the fluid circulates between the heat pipe 100 and the second refrigerant storage tank 120, the level of the working fluid 104a in the heat pipe 100 may increase with time, but it is preferable to be kept as constant as possible. Do. Therefore, the amount of the liquid refrigerant flowing into the heat pipe 100 through the second connection pipe 128 and the amount of the working fluid 104a is preferably the same. For this reason, when the diameters of the first and second connection pipes 126 and 128 are the same, it is preferable that the interrupting capacity of the first and second refrigerant control means 126a and 128a is the same. When the diameters of the first and second connection pipes 126 and 128 are different, the amount of the working fluid 104a flowing out of the heat pipe 100 and the amount of the liquid refrigerant 104b flowing into the heat pipe 100 are the same. It is preferable to vary the intermittent capacity of the first and second refrigerant control means (126a, 128a).

Subsequently, the working fluid 104a flowing out from the heat pipe 100 to the second refrigerant storage tank 120 through the first connecting pipe 126 is hot, whereas the working fluid 104a flows through the second connecting pipe 128. 2 The liquid refrigerant supplied to the heat pipe 100 from the refrigerant storage tank 120 is preferably a predetermined temperature, for example about 23 ℃. Therefore, it is preferable to lower the working fluid 104a introduced into the second refrigerant storage tank 120 to the predetermined temperature. For this purpose, a second cooling device 124 is provided in the second refrigerant storage tank 120. The second cooling device 124 is preferably provided above the second refrigerant storage tank 120, but may be provided at the lower portion, as shown by reference numeral 125, may be provided on the side in some cases.

On the other hand, when the second cooling device 124 is composed of an evaporator and a condensation unit, the evaporation unit may be provided on the upper, lower and / or side of the second refrigerant storage tank 120, the condensation unit is spaced from there Can be prepared.

Third Embodiment

Referring to FIG. 6, a third connecting pipe 130 is provided outside the heat pipe 100 to circulate the upper surface S1, that is, the working fluid 104a filled in the heat pipe 100 during hot plate cooling. have. One end of the third connecting pipe 130 is connected to one side of the heat pipe 100, and the other end is connected to the other side of the heat pipe 100. The third cooling device 132 is provided at a predetermined position of the third connecting pipe 130. The third cooling device 132 is provided to surround a portion of the third connecting pipe 130 and serves the same role as the second cooling device 124 provided in the baking system of the second embodiment. That is, it serves to lower the temperature of the working fluid 104a flowing out of the heat pipe 100 flowing through the third connecting pipe 130 to a predetermined temperature. The first refrigerant control means 126a described in the second embodiment is installed on the third connection pipe 130 between one side of the heat pipe 100 and the third cooling device 132 through which the working fluid 104a flows out. The second refrigerant control means 128a is provided between the other side of the heat pipe 100 through which the liquid refrigerant flows from the third cooling device 132 and the third cooling device 132.

Fourth Example

Referring to FIG. 7, third and fourth refrigerant storage tanks 134 and 136 are provided outside the heat pipe 100. The third and fourth refrigerant storage tanks 134 and 136 store the high temperature working fluid 104a flowing out of the heat pipe 100 when the hot plate is cooled, and cools the same to a predetermined temperature. To this end, fourth and fifth cooling devices 144 and 146 are mounted to the third and fourth refrigerant storage tanks 134 and 136, respectively.

Meanwhile, since cooling of the hot plate starts, the working fluid 104a flows out of the heat pipe 100 and at the same time, the amount of liquid refrigerant is supplied to the heat pipe 100, thereby storing the third and fourth refrigerants. It is preferable that a predetermined amount of liquid refrigerant at a predetermined temperature, for example, 23 ° C., is stored in the tanks 134 and 136, particularly in the fourth refrigerant storage tank 136 near the side where the liquid refrigerant of the heat pipe 100 flows. .

The fourth and fifth cooling devices 144 and 146 serve as the second cooling device 124 of FIG. 5 provided in the baking system according to the second embodiment. The fourth and fifth chillers 144, 146 may be a single chiller, which is indicated virtually by reference numeral 148. Considering the positions where the third and fourth refrigerant storage tanks 134 and 136 are provided, since the liquid refrigerant flowing into the fourth refrigerant storage tank 136 passes through the third refrigerant storage tank 134, the third refrigerant The temperature is lower than the working fluid 104a flowing into the storage tank 134. For this reason, the fourth and fifth cooling devices 144 and 146 preferably have the same performance, but the performance of the fourth cooling device 144 may be higher than that of the fifth cooling device 146.

One side of the heat pipe 100 and the third refrigerant storage tank 134 are connected to the fourth connection pipe 138, and the third and fourth refrigerant storage tanks 134 and 136 are the fifth connection pipe 140. The other side of the heat pipe 100 and the fourth refrigerant storage tank 136 is connected to the sixth connecting pipe 142. The first refrigerant control means (126a) is installed in the fourth connection pipe 138, the third refrigerant control means (140a) is installed in the fifth connection pipe 140, the sixth connection pipe (142) Second refrigerant control means 128a is provided. Preferably, the third refrigerant control means 128a is an automatic or manual valve or pump, similarly to the first and / or second refrigerant control means 126a, 128a. First to third refrigerant control means (126a, 128a, 140a) is opened when the cooling of the hot plate begins, and is closed after the cooling of the hot plate is finished or the hot plate is heated for baking of a new wafer.

Looking at the cooling process of the hot plate, as the cooling of the hot plate is started, all of the first to third refrigerant control means 126a, 128a, 140a are opened, and the hot working fluid 104a of the heat pipe 100 4 is introduced into the third refrigerant storage tank 134 through a connection pipe (138). The hot working fluid 104a introduced into the third refrigerant storage tank 134 is first cooled by the fourth cooling device 144 and then the fourth refrigerant storage tank 136 through the fifth connection pipe 140. Flows into. The liquid refrigerant flowing into the fourth refrigerant storage tank 136 is cooled to a temperature suitable to be introduced into the heat pipe 100 by the fifth cooling device 146, and then through the sixth connection pipe 142. Flows into (100).

Such circulation of the fluid may be continuously performed until the hot plate is completely cooled, or may be repeated several times for a predetermined time, for example, 15 seconds. At this time, the temperature of the liquid refrigerant flowing into the heat pipe 100 from the fourth refrigerant storage tank 136 in the circulation may have any value under the condition that the hot working fluid 104a of the heat pipe 100 is lower. However, it is preferably within 80 ° C. This will be described later.

As described above, the hot working fluid 104a flowing out of the heat pipe 100 through the fourth connection pipe 138 passes through the third and fourth refrigerant storage tanks 134 and 136 in sequence and the hot plate. Is cooled to a temperature when the heat pipe 100 is filled before being heated. The main body may also be the third refrigerant storage tank 134 or the fourth refrigerant storage tank 136. In other words, the hot working fluid 104a is preferably gradually cooled while passing through the third and fourth refrigerant storage tanks 134 and 136, but only one third refrigerant storage tank 134 or the fourth refrigerant storage tank 136 is used. It can also be cooled to the desired temperature using.

Fifth Embodiment

As shown in FIG. 8, the baking system according to the fifth embodiment is the latter case, and the third and fourth refrigerant storage tanks 134 and 136 and the fourth and fifth cooling systems of the baking system according to the fourth embodiment are used. The third refrigerant storage tank 134 and the fourth cooling device 144 are removed from the auxiliary cooling unit including the cooling devices 144 and 146.

In FIG. 8, reference numeral 150 denotes a fifth refrigerant storage tank having an equivalent role to the fourth refrigerant storage tank 136, and 156 denotes a seventh cooling apparatus mounted in the fifth refrigerant storage tank 150. One side of the fifth refrigerant storage tank 150 and the heat pipe 100 is connected to the seventh connection pipe 152, and the other side of the fifth refrigerant storage tank 150 and the heat pipe 100 is the eighth connection pipe. 154 is connected. Fourth and fifth refrigerant control means 152a and 152b are sequentially installed in the seventh connection pipe 152 through which the hot liquid refrigerant 104a is supplied from the heat pipe 100 to the fifth refrigerant storage tank 150. have. A sixth refrigerant control means 154a is installed in the eighth connection pipe 154 through which the liquid refrigerant cooled to the heat pipe 100 is supplied from the fifth refrigerant storage tank 150. The fourth and sixth refrigerant control means 152a and 154a are automatic or manual valves, and the fifth refrigerant control means 152b is a pump. The sixth refrigerant control means 154a may be replaced with a pump.

Sixth Embodiment

9, the sixth refrigerant storage tank 160 is provided outside the heat pipe 100. One side of the sixth refrigerant storage tank 160 and the heat pipe 100 is connected to the ninth connection pipe 162, and the other side of the sixth refrigerant storage tank 160 and the heat pipe 100 is the tenth connection pipe. 164 is connected. The hot working fluid 104a flows from the heat pipe 100 to the sixth refrigerant storage tank 160 through the ninth connecting pipe 162. The hot working fluid 104a is cooled while passing through the sixth refrigerant storage tank 160 through the tenth connecting pipe 164, and the cooled working fluid is supplied to the heat pipe 100 again. A seventh refrigerant control means 162a is provided in the ninth connection pipe 162, and an eighth refrigerant control means 164a is provided in the tenth connection pipe 164. The seventh and eighth refrigerant control means 162a, 164a are automatic or manual valves or pumps. An eighth cooling device 160b is mounted below the sixth refrigerant storage tank 160, and an auxiliary heater 160a is mounted above it. The eighth chiller serves an equivalent role to the various chillers described above.

Meanwhile, the auxiliary heater 160a is used to heat the upper surface S1 of the heat pipe 100, that is, the hot plate surface together with the heater 102 provided under the heat pipe 100.

Specifically, as the heating of the upper surface S1 of the heat pipe 100 starts, the seventh and eighth refrigerant control means 162a and 164a are opened in the same state as in the case of cooling. . The working fluid filled in the heat pipe 100 is heated by the heater 102, and the working fluid present in or flowing into the sixth refrigerant storage tank 160 is heated by the auxiliary heater 160a. By the presence of such an auxiliary heater 160a, it is possible to reduce the load on the heater 102 when heating the upper surface S1 of the heat pipe 100 using the heater 102, and at the same time the heating time of the upper surface S1. Can also be reduced.

Next, the simulation results performed by the present inventors with respect to the cooling efficiency of the baking system of the present invention described above will be described.

The present inventors used the system shown in FIG. 4 as the bake system of the present invention in the simulation, and the bake system according to the prior art as shown in FIGS. 15 to 17 as a control for the bake system of the present invention (hereinafter, Control bake system). At this time, the upper surface of the heat pipe provided in the base system of the present invention, that is, the hot plate and the hot plate of the control base system were heated to 150 ° C. and then cooled to 100 ° C.

15 and 16 are front views of portions associated with the hot plate 200 of the control bake system in which the first and second cooling lines 206 and 208 to which cooling water, for example, water is supplied, are embedded in the hot plate 200, respectively. And in plan view, FIG. 15 shows a front view of the portion where the first cooling line 206 of the hot plate 200 is embedded, that is, the left half of the hot plate 200, and FIG. 16 shows the first and second cooling. Show the plane of the entire hot plate with lines 206 and 208 inherent.

In FIG. 15, reference numeral 202 denotes a heater, and 204 denotes a lower plate. Reference numeral Lc denotes a center line passing through the center of the hot plate 200 shown in FIG.

FIG. 17 is a partial front view of the control bake system when the cooling line 210 to which the coolant is supplied is embedded in the heater lower plate 204.

10 to 14 are graphs showing simulation results for the control bake system, and FIGS. 18 to 20 are graphs showing simulation results for the bake system of the present invention.

Specifically, Figures 10, 11, 13 and 14 all show the change according to the cooling time of the average temperature and the maximum temperature deviation of the upper surface of the hot plate of the control bake system, Figure 10 shows the natural cooling of the hot plate System cooling (hereinafter referred to as a first case), and FIG. 11 shows a ratio of 1.5 liters per minute (total 3 liters / minute) of cooling water at 23 ° C. in each of the first and second cooling lines 206 and 208. In this case, the hot plate is cooled (hereinafter referred to as a second case), and FIG. 13 shows the hot plate by supplying air at 23 ° C. instead of cooling water to the first and second cooling lines 206 and 208. In the case of cooling (hereinafter referred to as a third case), FIG. 14 shows 1.5 liters of cooling water at 18 ° C. per minute (3 liters in total) in the cooling line 210 embedded in the lower plate 204 provided under the heater 202. Per minute) to cool the hot plate (hereinafter referred to as fourth case). 12 shows the time required for temperature stabilization in the second case.

Reference numeral G1 of FIG. 10, reference numeral G3 of FIG. 11, reference numeral G5 of FIG. 12, reference numeral G7 of FIG. 13, and reference numeral G9 of FIG. 14 are all hot plates according to time during the cooling process of the hot plate 200. First, third, fifth, seventh, and ninth graphs showing changes in average temperature of the upper surface of 200. In addition, reference numeral G2 of FIG. 10, reference numeral G4 of FIG. 11, reference numeral G6 of FIG. 12, reference numeral G8 of FIG. 13, and reference numeral G10 of FIG. 14 are all hot plates according to time during the cooling process of the hot plate 200. Second, fourth, sixth, eighth, and tenth graphs showing changes in the maximum temperature deviation of 200.

Referring to the first and second graphs G1 and G2 of FIG. 10, in the first case, it takes 50 minutes to cool the hot plate 200 from 150 ° C. to 100 ° C., and the maximum of the hot plate 200. It can be seen that the temperature deviation is about 0.2 ° C to 0.3 ° C.

In addition, referring to the third graph G3 of FIG. 11, in the second case, the time required for cooling the hot plate 200 from 150 ° C. to 100 ° C. may be short as about 10 seconds. It can be seen from G4) that the maximum temperature deviation of the hot plate 200 is very large, about 70 ° C to 80 ° C.

In the second case, for this reason, as shown in the fifth and sixth graphs G5 and G6 of FIG. 12, the time is about 5 minutes until the temperature is stabilized after the hot plate 200 is cooled to 100 ° C. This takes

Subsequently, referring to the seventh and eighth graphs G7 and G8 of FIG. 13, in the third case, it takes about 35 minutes to cool the hot plate 200 from 150 ° C. to 100 ° C., and the hot plate It can be seen that the maximum temperature deviation of (200) is expected to be about 1.0 ° C to 2.0 ° C.

In addition, referring to the ninth and tenth graphs G9 and G10 of FIG. 14, in the fourth case, it takes about 95 seconds to cool the hot plate 200 from 150 ° C. to 100 ° C., and the maximum temperature deviation. It turns out that is about 6 degreeC. And it can be seen that it takes about 4 minutes and 20 seconds to stabilize the temperature.

Meanwhile, FIGS. 18 to 20 are graphs showing simulation results of the baking system of the present invention. The eleventh and twelfth graphs G11 and G12 of FIG. 18 are liquid refrigerant at 23 ° C. for 15 seconds apart. The change in the average temperature and the maximum temperature deviation of the upper surface of the hot plate with the time of three cycles (hereinafter referred to as the fifth case) is shown.

In addition, the thirteenth and fourteenth graphs G13 and G14 of FIG. 19 show a hot plate upper surface according to time when the liquid refrigerant at 50 ° C. is circulated four times at intervals of 15 seconds (hereinafter, referred to as a sixth case). The change of the average temperature and the maximum temperature deviation is shown.

In addition, the fifteenth and sixteenth graphs G15 and G16 of FIG. 20 each show an upper portion of the hot plate according to time when the liquid refrigerant at 80 ° C. is circulated six times at intervals of 15 seconds (hereinafter, referred to as a seventh case). The change in average temperature and maximum temperature deviation of the surface is shown.

Referring to the eleventh and twelfth graphs G11 and G12 of FIG. 18, it can be seen that in the fifth case, the hot plate is cooled to 100 ° C. within 40 seconds, and the maximum temperature deviation ΔT of the hot plate is ΔT. ) Shows that ΔT <0.4 ° C.

Referring to the thirteenth and fourteenth graphs G13 and G14 of FIG. 19, it can be seen that in the sixth case, the hot plate is cooled to 100 ° C. within 60 seconds, and the maximum temperature deviation (Δ) of the hot plate is Δ. It turns out that T) is (DELTA) T <0.2 degreeC.

In addition, referring to the fifteenth and sixteenth graphs G15 and G16 of FIG. 20, in the seventh case, the hot plate is cooled to 100 ° C. within 90 seconds, and the maximum temperature deviation of the hot plate ( It is understood that ΔT) is ΔT <0.2 ° C.

The table below summarizes the issues related to hot plate cooling of the control bake system described above and the bake system of the present invention. In the table, system 1 represents the bake system of the present invention and system 2 represents the control bake system. And "other" indicates a case where the cooling water temperature is 18 ° C in the second case.

 division Cooling time (150 ℃-> 100 ℃)  Temperature deviation (△ T) (℃)  Temperature stabilization time (△ T <1 ℃)  System 1   90 sec     0.2  1 minute 30 seconds System 2  The first case   50 minutes     0.2  50 minutes  The second case   10 sec  78  5 minutes  The third case   35 minutes   2  Fourth case   95 seconds   6  4 minutes 20 seconds  Other   10 sec  80

Referring to Table 1, in the control bake system (system 2), when the hot plate is cooled by using the cooling water (second and fourth cases, other), the cooling time is shorter than the bake system of the present invention ( 2 and others) Similar (fourth), but the temperature deviation (ΔT) is large, it can be seen that the time required to stabilize the temperature of the hot plate is much longer than the baking system of the present invention.

In other words, in the case of the baking system of the present invention, the cooling time is not significantly longer than that of the control baking system, and the temperature stabilization time is short and has the same temperature deviation as that of the natural cooling method (first case).

On the other hand, in the first case of the natural cooling method, because the time required for cooling and stabilization is too long compared to the bake system of the present invention, despite the low temperature deviation, it is difficult to be used in actual industrial sites.

As a result, through the analysis of the simulation results, the present inventors found that the baking system of the present invention is superior to any baking system of the control group when comprehensively considering productivity, cooling effect, and temperature uniformity.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. For example, those skilled in the art to which the present invention pertains may include a refrigerant storage device provided with an auxiliary heater for heating the liquid refrigerant, if necessary, after the refrigerant storage device provided with the cooling device. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, the baking system according to the present invention has a heat pipe having an upper surface used as a hot plate surface on which a wafer for baking is loaded and a wick for supplying a working fluid to the ceiling and the side. Accordingly, when the upper surface is cooled, the working fluid is supplied evenly and quickly to the entire ceiling area of the heat pipe, and as a result, the entire area of the upper surface is cooled evenly. Since the cooling of the upper surface is performed through vaporization of the working fluid supplied to the ceiling of the heat pipe, the time required for temperature stabilization of the upper surface, that is, the hot plate surface, is larger than that of the conventional cooling water circulation. Can be reduced.

On the other hand, an auxiliary cooling unit is connected to the heat pipe to circulate and cool the working fluid filled in the heat pipe when the upper surface is cooled. A refrigerant storage tank filled with a predetermined amount of liquid refrigerant to be sequentially exchanged with the working fluid during the cooling in the auxiliary cooling unit and a cooling device for preventing the temperature of the liquid refrigerant from rising as the working fluid is introduced thereto. It is provided. The refrigerant storage tank is provided with a pressurizing means or a second cooling device or auxiliary heater as necessary. The auxiliary cooling unit may maintain a low temperature of the working fluid filled in the heat pipe when the upper surface of the heat pipe is cooled, thereby increasing the cooling efficiency of the heat pipe in the cooling process. In addition, when the auxiliary heater is provided in the refrigerant storage tank, the heating time of the upper surface of the heat pipe, that is, the hot plate can also be reduced, resulting in higher productivity than the conventional case.

1 to 3 are cross-sectional views of a hot plate cooling apparatus according to the prior art.

4 to 9 are partial cross-sectional views of the baking system according to the first to sixth embodiments of the present invention.

10 is a graph showing a simulation result of the cooling efficiency of the baking system according to the prior art to which the natural cooling method is applied.

11 to 13 are graphs showing cooling efficiency simulation results for a conventional baking system having a cooling line embedded in a hot plate, and FIG. 11 is a graph showing before stabilization and FIG. 12 after stabilization, and FIG. 13. Is a graph showing the results when air is used as the refrigerant.

14 is a graph showing a cooling efficiency simulation result for a conventional baking system having a cooling line embedded in a lower part of a heater.

15 and 16 are partial front and top views, respectively, of a prior art bake system in which a cooling line is embedded in a hot plate, used as a control for the present invention in the simulations of the present inventors.

17 is a partial front view of a prior art bake system with a cooling line provided below the heater, used as a control for the present invention in the inventors' simulation.

18 to 20 are graphs showing the cooling efficiency of the bake system according to the embodiment of the present invention in the simulation of the present invention.

* Description of the symbols for the main parts of the drawings *

100: heat pipe 102: heater

104a: working fluid 104b: liquid refrigerant

106, 120, 134, 136, 150, 160: first to sixth refrigerant storage tank

108: valve 109: pressure means

160a: auxiliary heater

P1: Main body P1 ': Secondary cooling part

S1: Heat pipe upper surface (hot plate side)

W: Wafer

110, 124, 132, 144, 146, 148, 156, 160b: first to eighth chillers

112: cavity 125: cooling unit

126, 128, 130, 138, 140, 142, 152, 154, 162, and 164: first through tenth connectors

126a, 128a, 140a, 152a, 152b, 154a, 162a, 164a: first to eighth refrigerant control means

L1, L2: first and second flow paths

Claims (13)

A heat pipe loaded with a baking wafer on an upper surface thereof, filled with a predetermined amount of working fluid therein, and having a wick formed on a side surface and a ceiling for supplying the working fluid; A heater used to heat the upper surface through the heating of the working fluid; An auxiliary cooling unit having a liquid refrigerant to be exchanged with a working fluid of the heat pipe through circulation and having a heat pipe element; A connection pipe for circulating the working fluid and the liquid refrigerant and connecting the heat pipe and the auxiliary cooling part; Bake system, characterized in that the connecting pipe is provided with an intermittent means for the control of the fluid flowing through the connecting pipe. The bake system according to claim 1, wherein the connection pipes are first and second flow paths connecting the same side of the heat pipe and the same side of the auxiliary cooling unit. The method of claim 1, wherein the connection pipe is composed of a first connection pipe connecting one side of the heat pipe and one side of the auxiliary cooling unit and a second connection pipe connecting the other side of the heat pipe and the other side of the auxiliary cooling unit. A baking system characterized by the above-mentioned. The method of claim 2, wherein the auxiliary cooling unit, A refrigerant storage tank in which the liquid refrigerant is stored and a wick for a heat pipe function is formed on an inner surface thereof; A cooling device provided in the refrigerant storage tank for cooling the working fluid introduced thereto; And And a pressurizing means for pressurizing the liquid refrigerant upon cooling the upper surface. The method of claim 3, wherein the auxiliary cooling unit, A first refrigerant storage tank in which the liquid refrigerant is stored; And And a first cooling device provided in the first refrigerant storage tank for cooling the operating fluid introduced therein. The bake system according to claim 1, wherein the control means is a pump or a valve. The bake system according to claim 5, wherein a second refrigerant storage tank is connected to the first refrigerant storage tank, and the first cooling device extends to the second refrigerant storage tank. The bake system according to claim 5, wherein a second refrigerant storage tank is connected to the first refrigerant storage tank, and a second cooling device is provided in the second refrigerant storage tank. The bake system according to claim 1, wherein an auxiliary heater for heating a fluid flowing through the connection pipe is provided at the connection pipe between the other side of the heat pipe and the auxiliary cooling unit. 6. The baking system according to claim 5, wherein an auxiliary heater for heating the fluid supplied to the heat pipe is provided to the first refrigerant storage tank. A heat pipe loaded with a baking wafer on an upper surface thereof, filled with a predetermined amount of working fluid therein, and having a wick formed on a side surface and a ceiling for supplying the working fluid; A heater used to heat the upper surface through the heating of the working fluid; A connection tube having one end connected to one side of the heat pipe through which the working fluid flows out, and the other end connected to the other side of the heat pipe through which the leaked working fluid flows; A cooling device provided in the connection pipe and configured to cool the working fluid flowing through the connection pipe; Intermittent means provided in said connecting pipe for intermittent control of said working fluid; And And a working fluid circulating along the heat pipe and the conduit. The bake system according to claim 11, wherein the cooling device is provided to surround a portion of the connection pipe. 12. The bake system according to claim 11, wherein the control means is a pump or a valve provided between one side of the heat pipe and the cooling device and between the other side of the heat pipe and the cooling device, respectively.