WO2014045982A1

WO2014045982A1 - Coating device and coating method

Info

Publication number: WO2014045982A1
Application number: PCT/JP2013/074610
Authority: WO
Inventors: 健児林田; 北村　義之; 洋川竹; 大霜　征彦; 幸一村尾
Original assignee: 東レエンジニアリング株式会社; 東レ株式会社
Priority date: 2012-09-24
Filing date: 2013-09-12
Publication date: 2014-03-27
Also published as: CN104661759B; TWI594806B; KR102110628B1; JP2014061501A; CN104661759A; TW201420211A; KR20150060704A; JP6125783B2

Abstract

The present invention forms a coating film on a substrate with good precision and at high speed even when coating a coating solution of relatively high viscosity on the substrate. Specifically, the coating device (1) is provided with a tank (9) for storing the coating solution and a nozzle (3) in which a slit (21) for discharging the coating solution supplied from the tank (9) is formed. The coating solution is coated on the substrate by discharging the coating solution from the slit (21). The coating device (1) is provided with a temperature-raising unit (30) for raising the temperature of the coating solution supplied from the tank (9) and a temperature-homogenizing unit (40) for homogenizing the temperature of the coating solution, the temperature of which has been raised by the temperature-raising unit, prior to discharging the coating solution from the slit (21).

Description

Coating apparatus and coating method

The present invention relates to a coating apparatus and a coating method for applying a coating liquid onto a substrate by discharging the coating liquid from a slit formed in a base.

As a device for applying a coating solution to a substrate such as a glass substrate or a film, there is known a coating device provided with a die in which a slit for discharging the coating solution is formed (for example, see Patent Document 1). This coating apparatus includes a tank for storing the coating liquid and a pump for supplying the coating liquid in the tank to the slit of the base.
The slit is formed long along the width direction of the substrate. For example, the coating liquid is discharged onto the surface of the substrate by discharging the coating liquid from the slit while moving the base horizontally with respect to the substrate placed on the stage. A thin film (coating film) can be formed.

When using such a coating apparatus to start application of a coating solution having a relatively high viscosity to the substrate, the resistance of the resin piping from the pump to the base and the slit in the base prevents the pump from starting operation. A delay occurs in the flow of the coating liquid and the discharge operation of the coating liquid from the slit, and this delay affects the coating quality by reducing the coating thickness at the start of coating.

Further, if the supply speed of the coating liquid from the pump is increased in order to apply a coating liquid having a relatively high viscosity at a high speed, the resistance increases at the slit in the base, and the internal pressure increases. Due to this increase in internal pressure, the slit, which is an elongated linear shape, is deformed into an elongated drum shape, and the film thickness of the coating liquid ejected from the central part in the longitudinal direction (width direction) of the slit becomes thicker than the film thickness at the end part. As a result, the film thickness varies in the width direction, and the film thickness accuracy is greatly reduced. Furthermore, in order to form a coating film having the same thickness with a coating solution having a high viscosity and a coating solution having a low viscosity, a coating solution having a high viscosity has a higher coating speed (transfer of the die) than a coating solution having a low viscosity. There is also a principle problem that such a coating film cannot be formed unless the speed is reduced.
Therefore, when applying a coating liquid having a relatively high viscosity to the substrate, it is considered necessary to lower the supply speed of the coating liquid and to lower the moving speed of the die if the first priority is to ensure the coating quality. It is done. If the supply speed of the coating liquid (the flow speed of the coating liquid) is lowered, the resistance of the flow path can be reduced, and it is possible to suppress the occurrence of the delay as described above and the decrease in the film thickness accuracy in the width direction. Become.
As another means, the flow path resistance can be reduced by increasing the pipe diameter to the die without lowering the supply speed of the coating solution, and further increasing the slit gap (parallel gap width). And it becomes possible to suppress the fall of the film thickness precision of the width direction by generation | occurrence | production of the above delays or a deformation | transformation of a slit.

JP 2000-157906 A

However, as described above, when the supply speed of the coating liquid is slowed down and the moving speed of the die is slowed down, the coating time increases and productivity is impaired.
Further, as described above, when the pipe diameter to the base is increased, for example, when it is necessary to bend the pipe into a U shape, it is necessary to set the radius of curvature to be large, and the joint for the pipe is also increased. It is necessary, and the equipment from the pump to the base becomes large. If the gap between the cap slits is too large to reduce the channel resistance, the coating solution will not be discharged uniformly from the slits, and the film thickness accuracy in the width direction of the coating film formed on the substrate will be reduced. Decreases, and the coating quality is significantly reduced.
The above problems occur when the viscosity of the coating solution increases. Therefore, if the coating solution is heated to increase the temperature and decrease the viscosity, the above problem can be avoided. Furthermore, when the viscosity is lowered, the coating speed can be improved in order to obtain the same film thickness. However, if the coating solution is not heated uniformly and there is uneven viscosity due to uneven temperature, the coating solution will not be uniformly discharged in the width direction from the slit, the film thickness accuracy in the width direction will be reduced, and the coating quality will be impaired. End up.

Accordingly, an object of the present invention is to form a thin film (coating film) with a coating solution with high accuracy and at a high speed even when a coating solution having a relatively high viscosity is applied to the substrate. is there.

The present invention includes a tank for storing a coating liquid and a base in which a slit for discharging the coating liquid supplied from the tank is formed, and the coating liquid is discharged onto the substrate by discharging the coating liquid from the slit. A coating apparatus for coating, wherein the coating liquid supplied from the tank is heated, and before the coating liquid heated by the temperature rising section is discharged from the slit, the coating liquid And a temperature-equalizing section that equalizes the temperature.

According to the present invention, even when a coating liquid having a relatively high viscosity is applied to the substrate, the viscosity of the coating liquid discharged from the slit is lowered by raising the temperature of the coating liquid supplied from the tank. The resistance of the flowing coating liquid can be reduced. Moreover, when the coating liquid discharged from the slit has a temperature difference (temperature unevenness) in the longitudinal direction of the slit, the film thickness unevenness due to the viscosity unevenness occurs. Before discharging the applied coating liquid from the slit, the viscosity of the coating liquid can be made uniform by making the temperature of the coating liquid uniform, so that a coating film having a uniform thickness can be formed on the substrate. it can. As a result, the coating film can be formed on the substrate with high accuracy. Furthermore, it becomes possible to apply at higher speed by lowering the viscosity.

The soaking part is a flow path through which the coating liquid heated by the heating means and the temperature raising part flows, and the cross section of the flow path perpendicular to the flow direction of the coating liquid is narrowed in at least one direction. A heat transfer channel, wherein the heat generated by the heating means is transferred to the coating solution flowing through the heat transfer channel, and the temperature of the coating solution heated by the temperature raising unit is increased. It is preferable to make it uniform.
In this case, the coating liquid heated by the temperature raising unit flows through the heat transfer channel having a narrow channel cross section, and the heat generated by the heating means is applied to the coating solution flowing through the heat transfer channel. Is transmitted in one direction in which the cross section of the flow path is narrowed, and the temperature of the coating liquid is made uniform to the inside of the coating liquid. As described above, since heat transfer is performed when the coating liquid flows through the heat transfer channel having a narrow channel cross section, it is easy to make the temperature of the coating solution uniform not only in the width direction but also inside.

The heat transfer flow path is a flow path different from the slit, and an enlarged space flow path for storing a coating liquid is provided between the heat transfer flow path and the slit. preferable.
In this case, the coating liquid having a uniform temperature can be distributed more uniformly while temporarily maintaining the temperature by accumulating in the expansion space flow path, and the coating liquid can be distributed from the expansion space flow path to the slit. The liquid can be discharged. For this reason, a coating film can be formed more accurately and uniformly on a substrate.

Further, the slit that becomes the first slit, the first manifold that is connected to the first slit, the second manifold, and the second slit that connects the first manifold and the second manifold are formed in the base. Preferably, the second slit is formed in the base as the heat transfer channel, and the heating means heats the base.
In this case, the base is provided with a temperature-equalizing portion, the temperature of the coating liquid is made uniform in the base, and the coating liquid with the uniform temperature is discharged from the first slit.

In addition, the present invention is performed by a coating apparatus having a base in which a slit for discharging a coating liquid supplied from a tank is formed, and the coating liquid is applied to a substrate by discharging the coating liquid from the slit. The coating method is characterized in that the temperature of the coating solution supplied from the tank is raised, and the temperature of the coating solution is made uniform before discharging the heated coating solution from the slit. To do.
According to the present invention, it is possible to achieve the same effects as the coating apparatus.

According to the present invention, even when a coating liquid having a relatively high viscosity is applied to the substrate, the viscosity of the coating liquid discharged from the slit is lowered by raising the temperature of the coating liquid supplied from the tank. The resistance of the flowing coating liquid can be reduced, and before discharging the heated coating liquid from the slit, the temperature of the coating liquid is made uniform to make the viscosity uniform at a low value, Thereby, a coating film having a uniform thickness can be formed on the substrate at a high speed. As a result, it is possible to form the coating film on the substrate with high accuracy and with high productivity by high-speed coating.

It is the schematic which shows one Embodiment of the coating device of this invention. It is a schematic explanatory drawing explaining the structure of a nozzle | cap | die, a liquid supply part, etc., The inside of a nozzle | cap | die is shown by the cross section orthogonal to the longitudinal direction of a nozzle | cap | die. It is sectional drawing orthogonal to the longitudinal direction of a nozzle | cap | die.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[About the configuration of the coating device]
FIG. 1 is a schematic view showing an embodiment of a coating apparatus 1 of the present invention. The coating apparatus 1 includes a stage 2 on which a substrate W such as glass can be placed, a base 3 in which a slit 21 is formed, and a horizontal movement (X-direction movement) of the base 3 with respect to the substrate W on the stage 2. And a driving device 4 that freely and independently performs vertical movement (movement in the Z direction). The coating apparatus 1 further includes a tank 9 for storing the coating liquid, and a liquid feeding means including a pump 8 for supplying the coating liquid in the tank 9 to the base 3 as a liquid supply unit. Between the pump 8 and the base 3, a resin pipe (tube) 17 that constitutes the flow path of the coating liquid is installed.

In the present embodiment, the coating liquid in the tank 9 is at room temperature (the temperature in the room where the coating apparatus 1 is installed). Moreover, the coating liquid which apply | coats with this coating device 1 is a liquid with comparatively high viscosity at normal temperature. Examples of the coating liquid include a polyimide solution for a flattening film, a partition wall dispersion containing glass particles that form partition walls of a plasma display back plate, and the like. The comparatively high viscosity here means 100 mPas or more.

According to this coating apparatus 1, the pump 8 supplies the coating liquid in the tank 9 to the base 3, and the base 3 is lowered vertically by the driving device 4 so that a parallel clearance between the tip 23 and the substrate W is established. After the predetermined value is reached, a thin film (coating film) M is formed on the substrate W by discharging the coating liquid from the slit 21 while moving the base 3 horizontally, and the coating liquid is applied. can do. For this reason, the moving direction of the nozzle | cap | die 3 turns into an application | coating direction (X direction).
In addition, the coating apparatus 1 includes a control device 5 that controls the operation of each part of the coating device 1, and the control device 5 performs the coating operation of discharging the coating liquid onto the substrate W in addition to the movement of the base 3. Control.

FIG. 2 is a schematic explanatory diagram illustrating the configuration of the base 3 and the liquid supply unit, and the base 3 is cut in the middle of the longitudinal direction, and the inside of the base is shown by a cross section orthogonal to the longitudinal direction. Note that the longitudinal direction of the base 3 coincides with the width direction. The slit 21 formed inside the base 3 is long in the width direction of the base 3, and is opened at the front end portion 23 which is the front end of the base 3 (lower end of the base 3). The gap amount B of the slit 21 is constant along the width direction of the base 3. The width direction of the base 3 is a horizontal direction (Y direction) orthogonal to the application direction (X direction), and the gap amount B of the slit 21 is a dimension obtained by measuring the slit 21 in the X direction. The entire base 3 is made of metal and has high thermal conductivity.

The slit 21 has an elongated shape when viewed in the Z direction, which is the flow direction of the coating liquid, and is long in the width direction (Y direction) and narrow in the coating direction (X direction). The slit 21 is connected to the manifold 11 formed inside the base 3. Similarly to the slit 21, the manifold 11 is also formed long in the width direction.
The coating liquid is discharged from the tip of the die 3 through the manifold 11 and the slit 21. That is, the front end portion 23 which is an opening at the lower end of the slit 21 serves as a discharge port for the coating liquid. The tip portion 23 of the base 3 where the slit 21 is open is horizontal and is formed linearly over the entire length in the width direction.

In addition to the manifold (first manifold) 11 and the slit (first slit) 21, the upstream side (tank 9 side) of the channel 3 for flowing the coating liquid is provided in the base 3. A two manifold 12 and a second slit 22 are also formed. That is, the flow path 10 formed in the base 3 includes a first slit which is the slit 21 having a discharge port for the coating liquid, a first manifold 11 connected to the first slit 21, the second manifold 12, and the like. A second slit 22 connecting the first manifold 11 and the second manifold 12 is provided. The formation positions in these caps 3 are the second manifold 12, the second slit 22, the first manifold 11, and the first slit 21 in this order from the upstream side through which the coating liquid flows. It becomes a step slit structure.

The second manifold 12 is formed long along the width direction of the base 3 and is constituted by a space having a circular cross section as shown in FIG. 3. In the present embodiment, the second manifold 12 is formed along the width direction of the base 3. The cross-sectional shape is the same. That is, the second manifold 12 is formed of a cylindrical space (hole).

The second slit 22 is opened to each of the second manifold 12 and the first manifold 11 and is configured as a flow path connecting the two. When the second slit 22 is viewed in the Z direction, which is the flow direction of the coating liquid, the second slit 22 has an elongated shape, and this elongated shape is the shape of the flow path cross section orthogonal to the flow direction of the coating liquid. . This channel cross section is long in the width direction (Y direction) and narrow in the application direction (X direction). The second slit 22 has the same width as the second manifold 12. Thereby, the coating liquid is sent in the Z direction from the second manifold 12 to the first manifold 11 in the second slit 22.

The first manifold 11 is formed long along the width direction of the base 3 as described above, and in the present embodiment, the first manifold 11 has the same shape and the same size as the second manifold 12. As will be described later, the first manifold 11 and the second manifold 12 have an action of widening the coating liquid (an action of distributing the liquid evenly in the width direction), but upstream of the first manifold 11. Since the expansion of the coating liquid is substantially achieved by the second manifold 12 positioned, the first manifold 11 may be configured to have a smaller volume than the second manifold 12.

And as above-mentioned, the 1st slit 21 is formed long along the width direction of the nozzle | cap | die 3, and in this embodiment, the 1st slit 21 is the flow direction (the coating liquid flow compared with the 2nd slit 22). The cross-sectional shapes of the channels perpendicular to the (Z direction) are the same and have the same width dimension. In addition, the pressure loss with respect to the flow of a coating liquid becomes large and the coating liquid becomes difficult to flow, so that the flow path cross section of the 1st slit 21 and the 2nd slit 22 becomes small. Therefore, in order to uniformly discharge the coating liquid without increasing the total pressure loss and to obtain a temperature equalizing effect which will be described later, the first slit 21 is the second slit 22. Alternatively, the cross-section of the flow path perpendicular to the flow direction of the coating liquid may be smaller, particularly narrow in the coating direction (X direction) (the gap amount B of the slit 21 may be smaller).

The pipe 17 extending from the pump 8 is in fluid communication with a supply port 18 provided in the base 3 shown in FIG. 3, and a supply hole 19 extending from the supply port 18 to the second manifold 12 is connected to the base 18. 3 is formed.
The supply hole 19 is opened in the second manifold 12, and the coating liquid is supplied to the second manifold 12. The coating liquid supplied to the second manifold 12 is widened in the width direction, and then flows in the order of the second slit 22, the first manifold 11, and the first slit 21, and is discharged onto the substrate W.

As shown in FIG. 2, the coating apparatus 1 of this embodiment includes a temperature raising unit 30 that raises the temperature of the coating solution supplied from the tank 9 by the pump 8, and a temperature equalizing unit 40 that equalizes the temperature of the coating solution. And. The temperature equalizing unit 40 makes the temperature of the coating solution uniform before discharging the coating solution heated by the temperature raising unit 30 from the first slit 21.

The temperature raising unit 30 includes one or a plurality of temperature raising units 31, and in the present embodiment, the temperature raising unit 30 includes three temperature raising units 31. Each of the temperature raising units 31 includes a flow path 32 through which the coating liquid that is connected to the pipe 17 and sent from the pipe 17 flows, a heater that heats the coating liquid flowing through the flow path 32, and a heat insulating material that covers all or part of the heater. Etc. These temperature raising units 31 are continuously installed in the longitudinal direction of the flow path 32, and are provided adjacent to the base 3. Each temperature raising unit 31 heats the flow path 32 from the outside, thereby transferring heat to the coating liquid flowing in the flow path 32 to raise the temperature.

The heater of each temperature raising unit 31 is controlled by the control device 5, and the temperature raising unit 30 raises the temperature of the coating liquid at room temperature T0 to a required temperature T1 of 30 to 50 ° C., for example. The required temperature T1 is determined by coating specifications such as the type and viscosity of the substrate W and the coating liquid, and the discharge amount of the coating liquid. Furthermore, in order to efficiently raise the temperature of the coating liquid to the required temperature T1, in this embodiment, an insufficient temperature raising unit 31 can be added or an excessive temperature raising unit 31 can be removed. . That is, the number of the temperature raising units 31 can be changed so that the temperature raising unit 30 can have the amount of heat necessary for raising the temperature of the coating liquid to the required temperature T1. Then, the heated coating liquid is sent into the base 3 from the supply port 18 connected to the flow path 32.

The temperature equalizing unit 40 includes a heating unit that heats the base 3 and a heat transfer flow path that is formed as part of a flow path through which the coating liquid flows inside the base 3. The heating means according to the present embodiment includes a plurality of heaters 41 (divided heaters), and the heat transfer channel includes the second slit 22.
Each heater 41 heats the base 3 to apply heat to the coating liquid flowing through the flow path 10 formed inside the base 3. Each heater 41 is controlled by the control device 5, and the temperature equalizing unit 40 equalizes the temperature of the coating liquid heated to the required temperature T 1 by the temperature increasing unit 30 over the width direction (Y direction) of the base 3. (Hereinafter also referred to as soaking).

In the temperature equalizing section 40, a plurality of heaters 41 are provided side by side along the width direction (Y direction) of the base 3 in order to equalize the temperature of the coating solution. The heater 41 is attached to the base 3 such that the base 3 is sandwiched from both sides in the X direction.
A temperature sensor (not shown) is provided in each part of the base 3, in particular, the wall part 14 on both sides of the second slit 22, and based on the detection signal of this temperature sensor, the control device 5 The individual heaters 41 are controlled so that the wall portion 14 has a uniform temperature along the Y direction, and further, the base 3 has a uniform temperature as a whole. Thereby, it becomes possible to maintain the nozzle | cap | die 3 (wall part 14) at the same temperature over the width direction (Y direction) full length.

According to this temperature equalizing section 40, the base 3 (wall part 14) is maintained at a uniform temperature by the heater 41, and the temperature of the coating liquid flowing through the second slit 22, which is a heat transfer channel, is changed to the base 3 (wall By bringing the temperature close to the temperature of the part 14), it becomes possible to equalize the temperature of the coating solution. That is, heat transfer is performed so that the temperature of the base 3 (wall portion 14) and the temperature of the coating solution are the same.

As described above, the second slit 22 is a flow path for flowing the coating liquid heated by the temperature raising unit 30, and the flow path cross section orthogonal to the flow direction (Z direction) of the coating liquid is one direction X This is a heat transfer channel that narrows in the direction, and the coating liquid that flows through the second slit 22 (heat transfer channel) through the base 3 (the walls 14 on both sides) through the heat generated by the heater 41. The temperature of the coating solution heated by the temperature raising unit 30 is made uniform to the inside of the coating solution.
“The cross section of the flow path perpendicular to the flow direction (Z direction) of the coating solution is narrow in the X direction, which is one direction” means that the cross sectional dimension of the flow path in the X direction is small. In other words, it means that the gap amount of the second slit 22 is small.

As described above, the heater 41 and the control device 5 cause the wall portion 14 around at least the second slit 22 of the base 3 to have a uniform temperature in the width direction of the base 3, and from the wall portion 14, With respect to the coating liquid flowing through the two slits 22 (heat transfer flow path), heat transfer is performed in the X direction in which the flow path cross section perpendicular to the flow direction of the coating liquid is narrow. As a result, heat is transferred to the coating solution that is thin in the X direction, so that no temperature distribution occurs in the X direction due to heat conduction in the coating solution. That is, the temperature is equalized to the inside of the coating solution.
Note that, in a portion having a relatively large channel cross section such as the channel 32 of the temperature raising unit 30 or the second manifold 12, even if heat is transferred from the wall surface outside the channel cross section to the coating liquid, the channel cross section It is difficult to conduct heat from the outer part to the central part of the coating solution, and the coating solution is less likely to be soaked.
On the other hand, in the second slit 22, the temperature of the coating liquid can be made more uniform by reducing the gap amount. For example, the temperature of the coating liquid passing through the second slit 22 can be made uniform within a range of ± 0.2 ° C.

The second manifold 12 exists on the upstream side of the second slit 22, and exists as an enlarged space channel that accumulates the coating liquid flowing in from the supply hole 19 and widens in the width direction. This contributes to feeding the coating solution uniformly in the width direction toward the manifold 11. The second manifold 12 also serves to maintain the temperature of the coating liquid heated by the temperature raising unit 30.

Further, the coating liquid flowing in the first slit 21 can also receive heat from the heater 41 in the base 3, and thus has a function of equalizing the temperature of the coating liquid to the inside as in the second slit 22. However, the first slit 21 and the first manifold 11 are mainly provided to perform other functions.
That is, the first manifold 11 can temporarily store the coating liquid that has been heated to the inside of the coating liquid by the second slit 22 and has a uniform viscosity. In particular, the flow path is narrowed by the first slit 21. Thereby, the inside of the first manifold 11 can be filled with the coating liquid. Thereby, the pressure of the coating liquid in the first manifold 11 (pressure in the first manifold 11) is made uniform, and the pressure of the coating liquid discharged from the first slit 21 is made uniform over the entire length of the base 3 in the width direction. , The discharge accuracy in the width direction can be increased.

Thus, the second slit 22 is a heat transfer channel, and this heat transfer channel is functionally different from the first slit 21 which is a coating solution discharge channel having a coating solution discharge port. It is a flow path. That is, the second slit 22 that is a heat transfer channel is a channel that plays a role different from the first slit 21 for discharging the coating liquid. The first manifold 11 is interposed between the second slit 22 and the first slit as an enlarged space channel that accumulates the coating liquid and widens it in the width direction.

According to the coating apparatus 1 according to the above-described embodiment, even when the coating liquid having a relatively high viscosity is applied to the substrate W, the coating liquid supplied from the tank 9 is raised by the temperature raising unit 30. By heating, the viscosity of the coating liquid discharged from the first slit 21 can be lowered, and the resistance of the flowing coating liquid can be reduced without increasing the cross-sectional area of the pipe 17 and the gap amount B of the slit 21. Is possible.
In addition, when the coating liquid discharged from the first slit 21 has a temperature difference (temperature unevenness) in the longitudinal direction of the first slit 21, the viscosity unevenness occurs. However, according to the present invention, the temperature of the coating solution is made uniform by the temperature equalizing unit 40 before the coating solution heated by the temperature raising unit 30 is discharged from the first slit 21. Therefore, the coating film having a uniform thickness can be formed on the substrate W by making the viscosity uniform at a low value. As a result, the coating film can be formed on the substrate W with high accuracy and uniformity. In addition, by increasing the temperature of the coating solution and reducing the viscosity, coating can be performed at a higher speed, and as a result, it is possible to form a coating film on the substrate W accurately and uniformly at a high speed. Become.

In particular, in the present embodiment, the temperature equalizing unit 40 is a channel through which the coating liquid heated by the heater 41 and the temperature raising unit 30 flows, and is a channel cross section orthogonal to the flow direction (Z direction) of the coating solution. Has a second slit 22 (heat transfer channel) that is narrow in the X direction, and heat generated by the heater 41 is transferred to the inside of the coating liquid flowing through the second slit 22 to raise the temperature. The temperature of the coating liquid heated by the unit 30 is made uniform to the inside, thereby realizing a uniform viscosity up to the inside of the coating liquid.
Thus, since the heat transfer is performed when the coating solution flows through the second slit 22 where the flow path cross section perpendicular to the flow direction of the coating solution is narrow, the temperature of the coating solution immediately before the coating is performed is uniform. Accordingly, the viscosity of the coating solution can be lowered and uniformized to the inside.
Then, the temperature of the coating solution is made uniform at the base 3, whereby the coating solution is discharged from the first slit 21 with a low and uniform viscosity, and as a result, a coating film can be formed at a high speed.

The coating method for coating the substrate W with the coating apparatus 1 raises the temperature of the coating liquid supplied from the tank 9 and discharges the heated coating liquid from the first slit 21. Before, the temperature of this coating solution is made uniform. In particular, in the present embodiment, the heat generated by the heater 41 is transmitted to the coating liquid flowing through the second slit 22 which is a heat transfer channel, and the temperature and viscosity of the heated coating liquid are made uniform.

Moreover, according to the coating apparatus 1 which concerns on this embodiment, the temperature is raised by raising the temperature of the coating liquid from room temperature by the temperature raising unit 30, thereby reducing the viscosity of the coating liquid from the first slit 21 having a small slit width. Thus, it is possible to apply a coating solution with a thin film thickness at a high coating speed. In order to increase the coating speed, the supply speed of the coating liquid from the pump 8 may be increased while increasing the moving speed of the base 3.
Furthermore, according to this coating apparatus 1, since the heater is not provided in the pump 8, the tank 9, and the piping from the pump 8 to the temperature rising part 30, the case where the heater is provided in the whole including the tank 9 etc. Cost (initial cost and running cost) can be reduced as compared with equipment.

Further, in the present embodiment, the heating means provided in the temperature equalizing unit 40 includes the divided heaters 41 divided into a plurality of parts, and the output of each heater 41 is individually controlled by the control device 5. Even if the heat dissipation characteristics are different in each part in the width direction, the base 3 can be maintained at a uniform temperature.
Further, even if dissolved air is foamed by raising the temperature of the coating solution by the temperature raising unit 30, an air vent hole (not shown) is provided in the upper part of the flow path 10 (second manifold 12) in the base 3. It is also possible to remove the bubbles generated in the temperature raising unit 30 from here.

The embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of rights of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope equivalent to the configurations described in the claims.
For example, in the above-described embodiment, the case where the application operation is performed by moving the base 3 with respect to the stage 2 (see FIG. 1) in the fixed state has been described. The coating apparatus may be configured so that the coating operation is performed by moving the stage 2 on which the substrate W is placed with respect to a certain base 3.

Moreover, although the said embodiment demonstrated the case where the 2 steps | paragraph manifold structure and the 2 step | paragraph slit structure were formed in the nozzle | cap | die 3, a manifold and a slit should just be multistage | paragraphs and may be three or more steps | paragraphs. The most downstream first manifold and the most downstream first slit mainly have a function of stably discharging the coating liquid, and the upstream side (pump 8 side) manifold and slit are It has the function of soaking.
Further, the shape of the cross section perpendicular to the width direction of each manifold may be any shape such as a circle, a semicircle, a polygon, or a combination of a quarter circle and a right triangle. The cross-sectional shape orthogonal to the width direction of the manifold may be changed along the width direction. In this case, it is preferable to make the cross-sectional area of the center part in the width direction larger than the cross-sectional areas of both end parts.
In the embodiment, the case where the heater 41 is attached to the side surface of the base 3 in the temperature equalizing unit 40 has been described. However, the heater 41 may be attached to the upper part of the base 3 or the like.

1: coating device 3: base 9: tank 11: first manifold (enlarged space channel) 12: second manifold 21: first slit (slit) 22: second slit (heat transfer channel) 23: tip 30: Temperature rising part 40: Temperature equalizing part 41: Heater (heating means) W: Substrate

Claims

A coating for storing a coating solution and a base having a slit for discharging the coating solution supplied from the tank, and applying the coating solution to the substrate by discharging the coating solution from the slit A device,
A temperature raising unit for raising the temperature of the coating solution supplied from the tank;
A temperature equalizing unit that equalizes the temperature of the coating solution before discharging the coating solution heated by the heating unit from the slit;
An applicator characterized by comprising:
The temperature-equalizing unit is a channel through which the coating liquid heated by the heating unit and the temperature raising unit flows, and the channel cross section perpendicular to the flow direction of the coating solution is narrowed in at least one direction. A flow path for transmission, and the heat generated by the heating means is transferred to the coating liquid flowing through the flow path for heat transmission, so that the temperature of the coating liquid heated by the temperature raising unit is made uniform. The coating device according to claim 1 to be made.
The heat transfer channel is a channel different from the slit,
The coating apparatus according to claim 2, wherein an enlarged space channel for storing a coating liquid is provided between the heat transfer channel and the slit.
In the base, the slit serving as the first slit, the first manifold connected to the first slit, the second manifold, and the second slit connecting the first manifold and the second manifold are formed. ,
The second slit is formed in the base as the heat transfer channel,
The coating apparatus according to claim 2, wherein the heating unit heats the base.
A coating method is performed by a coating apparatus having a base in which a slit for discharging a coating liquid supplied from a tank is formed, and the coating liquid is applied to a substrate by discharging the coating liquid from the slit. ,
Raise the temperature of the coating solution supplied from the tank,
A coating method characterized in that the temperature of the coating solution is made uniform before discharging the heated coating solution from the slit.