JP7219562B2 - Coating method and coating device - Google Patents

Description

The present invention relates to a method for applying a coating liquid to a substrate and a coating apparatus for applying the coating liquid to the substrate.

In a semiconductor manufacturing process, a semiconductor wafer (silicon wafer) is coated with a photoresist solution. Spin coating is known as a method for this application, but in recent years, from the viewpoint of improving the utilization efficiency of the photoresist solution, slit coating using an applicator provided with slits has been proposed. The slit is opened at the tip surface of the nozzle portion of the applicator, and the coating liquid is discharged from the slit while the applicator and the semiconductor wafer are moved relative to each other. Patent Literature 1 discloses an applicator equipped with the applicator.

Japanese Patent Application Laid-Open No. 2015-192984

FIG. 12 is a plan view of a substrate (semiconductor wafer) 90. FIG. In the semiconductor manufacturing process, in order to increase the utilization efficiency of the substrate 90 , the vicinity of the outer peripheral edge 91 of the substrate 90 is defined as a semiconductor chip formation region P. Therefore, in the substrate 90, it is preferable to make the range Q of the coating liquid film thickness defect from the outer peripheral edge 91 as narrow as possible.

Capillary coating is known as an example of a coating method using slit coating as described above. This method is carried out while maintaining the application liquid in the applicator at a negative pressure with respect to the atmospheric pressure. As a result, when the applicator and the substrate are moved relative to each other while the coating liquid discharged from the applicator is adhered to the substrate, only the amount of the coating liquid that fills the gap formed between the tip surface of the applicator and the substrate is applied. is pulled out from the slit and applied. Further, in such a coating method, the speed of relative movement between the applicator and the substrate is kept constant in order to keep the film thickness of the coating liquid applied to the substrate constant. However, in order to start the application, as shown in FIG. 13A, the slit 98 of the applicator 99 is positioned just above the edge 92 of the substrate 90 and the application is stopped. In the stopped state, a small amount of the coating liquid R is discharged from the slit 98 to apply the liquid to the substrate 90 (surface 93 to be coated). When the application of the liquid is finished, the applicator 99 and the substrate 90 start to move relative to each other, and the coating liquid R is discharged from the slit 98 (see FIG. 13B). For example, when the applicator 99 is moved, the initial short time from the start of movement when the speed is zero until the movement speed becomes constant, that is, at the edge 92 of the substrate 90, as shown in FIG. Therefore, there is a problem that the film thickness t of the coating liquid R becomes thin. This becomes more remarkable when the viscosity of the coating liquid R is high. It should be noted that such a problem may occur even with a coating method other than capillary coating.

In order to prevent the film thickness t from becoming thin at the start of coating, as shown in FIG. 14, a method of additionally supplying the coating liquid to the applicator 99 by means of a pump 95 at the start of coating may be considered. . Since the substrate (semiconductor wafer) 90 is circular, the liquid is applied to the surface 93 to be coated in a region 90a of the slit 98 where the substrate 90 faces the substrate 90 when the coating is started. However, when the application is started, the liquid is not applied to the area 90b of the slit 98 where the substrate 90 does not face. Therefore, if the supply of the additional coating liquid by the pump 95 becomes excessive as described above, the coating liquid R is partially discharged from the region 90b of the slit 98 where the substrate 90 does not face. . If the coating is continued as it is, the coating liquid R that has been partially discharged from the region 90b causes streaks in the coating film, resulting in poor quality. A method of additionally supplying the coating liquid R to the applicator 99 by means of the pump 95 is effective for improving the thinning of the film thickness t at the start of coating, but there is a limit in some cases.

As shown in FIG. 13(C), when the range Q in which the film thickness t of the coating liquid R becomes thin at the end portion 92 on the coating start side of the substrate 90 widens, the semiconductor chip formation region P (see FIG. 12) and the semiconductor chip forming region P (see FIG. 12) The range in which the coating film should be uniform, that is, the range in which the coating film is uniform is reduced.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to suppress thinning of the coating film at the end of the surface to be coated on the coating start side.

According to the present invention, a widthwise elongated ejection port of an applicator that is long in the widthwise direction is brought close to a surface to be coated of a substrate, and the applicator and the surface to be coated are relatively moved in a direction crossing the widthwise direction. A coating method in which a coating liquid is ejected from the ejection port onto the surface to be coated while the substrate is being moved, the first substrate having a sheet shape and the second substrate having a sheet shape are arranged along the direction of the relative movement. The two substrates are arranged adjacent to each other, and the coating liquid is discharged from the discharge ports from the first substrate to the second substrate without discontinuity of the bead.

According to this coating method, since the second substrate is continuously coated from the first substrate without discontinuing the bead, at the end of the coated surface of the second substrate on the coating start side, It becomes possible to suppress thinning of the coating film. The first substrate can be used as an auxiliary substrate (dummy substrate) for coating. That is, the first substrate is not used as a product, and the second substrate is used as a product.

In the coating method, the applicator and the surface to be coated are relatively moved in a state in which the coating liquid ejected from the ejection port opened at the tip surface of the applicator adheres to the surface to be coated. Preferably, it is capillary coating in which the coating liquid is drawn out from the ejection port to fill the gap formed between the tip surface and the surface to be coated. According to such capillary coating, even if the coating liquid is continuously applied from the first substrate to the second substrate without breaking the bead, the first substrate and the second substrate can be coated through the space between both substrates. It is possible to prevent the coating liquid from going around to the back side of the. As a result, it is possible to prevent the coating liquid from adhering to the back surface of the substrate. This method can be realized by adjusting the pressure of the coating liquid in the applicator to a negative pressure when the ejection port is opened with a downward component, for example.

Further, the second substrate has a shape in which the dimension in the width direction increases from the end of the coating start side toward the coating end side, and the dimension in the width direction of the first substrate is the same as the width of the first substrate. It is preferably equal to or greater than the dimension in the width direction of the second substrate. In this case, a uniform film thickness can be obtained in the width direction of the second substrate.

According to the present invention, a widthwise elongated ejection port of an applicator that is long in the widthwise direction is brought close to a surface to be coated of a substrate, and the applicator and the surface to be coated are relatively moved in a direction crossing the widthwise direction. A coating method in which a coating liquid is discharged from the discharge openings onto the surface to be coated while the coating liquid is being After the substrate, two or more sheet-shaped second substrates are arranged adjacent to each other, and the coating liquid is discharged from the first substrate to the second substrate without breaking the bead. In addition, the coating liquid is discharged from the discharge port without discontinuity of the bead between the two or more second substrates.

According to this coating method, for the second substrate adjacent to the first substrate, coating is continuously performed without discontinuing the bead from the first substrate, and the bead is also applied between the second substrates. Since the coating is performed continuously without interruption, it is possible to prevent the coating film from becoming thin at the end portion of the coating start side of each coating surface of the second substrate. The first substrate can be used as an auxiliary substrate (dummy substrate) for coating. That is, the first substrate is not used as a product, and the second substrate is used as a product.

Further, in the coating method in which the first substrate and two or more second substrates are arranged side by side, a third substrate is arranged next to each of the second substrates in the width direction. and coating the third substrate together with the second substrate while arranging a plurality of the third substrates adjacent to each other in the direction of the relative movement following the first substrate. It is preferable to eject the liquid from the ejection port. In this case, by performing one stroke of relative movement between the applicator and the substrate, it is possible to coat many substrates.

A coating apparatus according to the present invention includes a stage on which a sheet-shaped substrate is placed, a coating device having a coating liquid discharge port longer than the dimension in the width direction of the substrate, and a coating device and the stage separated by the width. moving means for relatively moving in a direction intersecting with the direction, the stage includes a first area for disposing a first substrate having a sheet-like shape, and a second substrate having a sheet-like shape; and a second region arranged side by side along the direction of the relative movement.

According to this coating apparatus, the sheet-shaped first substrate and the sheet-shaped second substrate are arranged adjacent to each other along the direction of the relative movement, and from the first substrate to the second substrate. The coating liquid can be continuously discharged from the discharge port to the substrate without breaking the bead. As a result, since the second substrate is continuously coated from the first substrate without discontinuing the bead, the coating film is thin at the end of the coated surface of the second substrate on the coating start side. It is possible to prevent it from becoming

Moreover, it is preferable that the coating device further includes a pressure regulator that adjusts the pressure of the coating liquid in the applicator to a negative pressure. In this case, the coating method performed by the applicator is to move the applicator and the surface to be coated relatively in a state in which the coating liquid discharged from the discharge port opened at the tip surface of the applicator adheres to the surface to be coated. In this method, the coating liquid is drawn out from the ejection port to fill the gap formed between the tip surface and the surface to be coated. Even if the coating liquid is continuously applied from the first substrate to the second substrate without discontinuing the bead, the coating liquid is applied to the back surfaces of the first substrate and the second substrate through the space between the two substrates. You can keep it from going around. As a result, it is possible to prevent the coating liquid from adhering to the back surface of the substrate.

According to the present invention, it is possible to suppress thinning of the coating film at the end portion on the coating start side of the surface to be coated.

It is a schematic block diagram of a coating device. FIG. 4 is an explanatory view of the substrate held on the stage and the applicator viewed from above; FIG. 4 is an explanatory view of the substrate held on the stage and the applicator viewed from above; FIG. 3 is an explanatory view of the stage, substrate, and applicator in FIG. 2 viewed from the side; FIG. 4 is an explanatory view of the stage, substrate, and applicator in FIG. 3 as viewed from the side; FIG. 4 is an explanatory view of the substrate held on the stage and the applicator viewed from above; FIG. 7 is an explanatory view of the stage, substrate, and applicator in FIG. 6 viewed from the front; FIG. 10 is a diagram illustrating another form of the coating method, and is a top view of the substrate held on the stage and the applicator. FIG. 10 is a diagram illustrating another form of the coating method, and is a diagram of the substrate held on the stage and the applicator viewed from the side. FIG. 10 is a diagram illustrating still another form of the coating method, and is a top view of the substrate held on the stage and the applicator. It is explanatory drawing which expands and shows a 1st board|substrate and a 2nd board|substrate. 1 is a plan view of a substrate (semiconductor wafer); FIG. (A) is a side view of the substrate and the applicator and is an explanatory view of liquid application, and (B) is a side view of the substrate and the applicator and is an explanation during coating. It is a diagram. It is explanatory drawing which looked at the board|substrate and the applicator from the front.

[Regarding coating device and coating method]
FIG. 1 is a schematic configuration diagram of the coating device 5. As shown in FIG. The coating device 5 includes a coating device (also referred to as a slit die) 10 , moving means 20 , device base 30 , supply means 40 and control device 45 . The device base 30 has a stage 31 that holds the substrate 7 in the shape of a sheet. As will be described later, a plurality of substrates 7 are mounted on the stage 31 so as to form the same plane. The control device 45 is composed of a computer device. The substrate 7 of this embodiment includes a semiconductor wafer (silicon wafer), and the substrate 7 has a coated surface 8 on which a coating liquid (photoresist liquid) R is coated.

The applicator 10 is composed of a member elongated in the width direction (the direction perpendicular to the plane of the paper in FIG. 1). The applicator 10 has therein a reservoir 14 in which the coating liquid R is accumulated, and a slit (slit-shaped flow path) 15 connected to the reservoir 14 . The slit 15 opens at the tip surface 13 of the nozzle portion 17 of the applicator 10 , and this opening serves as a discharge port 16 for the coating liquid R. As shown in FIG. That is, the coating liquid R in the reservoir 14 is discharged from the discharge port 16 through the slit 15 . The reservoir 14 and the slit 15 are elongated along the width direction of the applicator 10 . The ejection port 16 (slit 15 ) is elongated in the width direction and longer than the dimension in the width direction of the substrate 7 . The applicator 10 is positioned above the substrate 7 and the coating liquid R is discharged downward from the discharge port 16 . The upper surface side of the substrate 7 becomes the coated surface 8 on which the coating liquid R is coated. Applicator 10 has a pressure sensor 46 . The pressure sensor 46 measures the pressure of the coating liquid R inside the applicator 10 (reservoir 14).

The moving means 20 includes a moving body 22 that can move in a direction that intersects the width direction of the applicator 10 (in this embodiment, a direction that is perpendicular to the direction), that is, in the horizontal direction in FIG. 1, and a linear actuator that moves the moving body 22. 23. The applicator 10 is mounted on the moving body 22. - 特許庁The moving means 20 moves the applicator 10 with respect to the substrate 7 while keeping the gap K between the coated surface 8 and the tip surface 13 constant. The moving means 20 of the present embodiment is configured to move the applicator 10 with respect to the substrate 7 which is in a fixed state. Although not shown, the stage 31 (substrate 7) may be moved with respect to the applicator 10 in a fixed state.

The supply means 40 has a tank 41 and a pressure regulator 42 . The tank 41 stores the application liquid R and is connected to the applicator 10 (reservoir 14 ) through a pipe 43 . The tank 41 is provided at a position higher than the applicator 10 . An open/close switching valve 44 is provided in the pipe 43, and when the valve 44 is open, the application liquid R can flow between the tank 41 and the applicator 10 (reservoir 14). Therefore, when the application liquid R is discharged from the applicator 10 and the application liquid R is consumed, the application liquid R is replenished from the tank 41 to the applicator 10 . The pressure regulator 42 consists of a regulator controlled by the control device 45, and changes the pressure of the coating liquid R in the tank 41 (regulates the pressure). Since the tank 41 and the applicator 10 are connected through the pipe 43, when the pressure of the application liquid R in the tank 41 is adjusted, the pressure of the application liquid R in the applicator 10 (reservoir 14) reaches a predetermined value. is adjusted (i.e. controlled) to In this embodiment, the inside of the tank 41 is sucked, and the pressure (gauge pressure) of the coating liquid R in the tank 41 is adjusted to a negative pressure by the pressure regulator 42 . As a result, the pressure (gauge pressure) of the application liquid in the applicator 10 (reservoir 14) becomes a negative pressure. The pressure regulator 42 adjusts the pressure of the application liquid R stored in the tank 41 so as to keep the pressure of the application liquid R in the applicator 10 at a predetermined value (negative pressure). This adjustment is performed based on the detection result of the pressure sensor 46 .

By adjusting the pressure of the coating liquid R in the applicator 10 to a predetermined value of negative pressure (relative to the atmospheric pressure), the coating device 5 can perform capillary coating on the substrate 7 . The coating method of this embodiment is a downward capillary coating method. That is, the tip surface 13 of the applicator 10 and the surface 8 to be coated are brought close to each other. A slit 15 opens at the tip surface 13 . The coating liquid R is drawn out from the slit 15 by capillary action (surface tension) between the tip surface 13 and the surface 8 to be coated, so that the coating liquid R is applied to the substrate 7 . More specifically, when the coating liquid R from the slit 15 (ejection port 16) contacts the surface 8 to be coated, a pool of the coating liquid R (hereinafter referred to as "bead") between the tip surface 13 and the surface 8 to be coated. ) is formed. In this state, when the applicator 10 is moved with respect to the substrate 7 , the coating liquid R is drawn out from the ejection port 16 only to fill the gap K between the tip surface 13 and the surface 8 to be coated, and is continuously applied to the substrate 7 . The coating liquid R is applied to the surface.

As described above, the coating apparatus 5 of this embodiment includes the stage 31 on which the sheet-shaped substrate 7 is placed, the coating device 10 having the ejection port 16 for discharging the coating liquid, the coating device 10 and the stage 31. and a moving means 20 for relatively moving the and. The coating method performed by the coating device 5 is to bring the discharge port 16 (tip surface 13) closer to the surface 8 to be coated of the substrate 7, and while relatively moving the applicator 10 and the surface 8 to be coated, the surface to be coated is coated. 8, the coating liquid R is discharged from the discharge port 16. FIG. Moreover, the coating device 5 further includes a pressure regulator 42 . The pressure regulator 42 regulates the pressure of the application liquid R in the applicator 10 to a negative pressure with respect to atmospheric pressure.

FIG. 2 is an explanatory view of the substrate 7 held on the stage 31 and the applicator 10 viewed from above. In addition, in FIG. 2 (FIG. 3 to be described later), the applicator 10 is indicated by an imaginary line (a two-dot chain line). In the following description, the direction of relative movement between the substrate 7 and the applicator 10 will be referred to as "movement direction". In each figure such as FIG. 2, the direction of movement is indicated by an arrow X, and the width direction perpendicular to the direction of movement is indicated by an arrow Y. As shown in FIG. The stage 31 has a width on which a plurality of substrates 7 can be placed. The stage 31 and the substrate 7 placed on the stage 31 will be specifically described. The area of the stage 31 on which the substrate 7 can be placed includes a first area Q1 and a second area Q2. A sheet-shaped substrate 7 is arranged in the first region Q1. The substrate 7 of the first region Q1 is called "first substrate 7a". A sheet-shaped substrate 7 is arranged in the second region Q2. The substrate 7 of the second region Q2 is called "second substrate 7b". The first area Q1 and the second area Q2 are continuous along the movement method. A sheet-shaped second substrate 7b is arranged adjacent to the first substrate 7a along the movement direction. The "adjacent" means a state in which (at least) a part of each side surface of two adjacent substrates 7a and 7b are in contact with each other without a gap.

In this embodiment, the first substrate 7a is rectangular and the second substrate 7b is circular in plan view. Therefore, part of the second substrate 7b is in contact with one side of the first substrate 7a. Since the second substrate 7b is circular, it can be said that it has a shape in which the dimension in the width direction gradually increases from the end 51 on the application start side toward the application end side (left side in FIG. 2). . It can be said that the latter half of the second substrate 7b has a shape in which the dimension in the width direction gradually decreases toward the coating end side (left side in FIG. 2).

As shown in FIGS. 2 and 3, a coating liquid R is applied to the first substrate 7a and the second substrate 7b. The coating liquid R is applied to the entire coated surface 8 of the second substrate 7b. The first substrate 7a does not have to be coated with the coating liquid R over the entire surface 8 to be coated. In other words, the coating liquid R is partially applied to the coated surface 8 of the first substrate 7a. The second substrate 7b is a silicon wafer and finally becomes a product. On the other hand, the first substrate 7a is a substrate that is not used as a product. The first substrate 7a is an auxiliary substrate used for coating the second substrate 7b, and is also called a dummy substrate. However, in order to apply the coating liquid R to the first substrate 7a and the coating liquid R to the second substrate 7b in the same environment (same conditions), the first substrate 7a is It is preferably made of the same material as the substrate 7b. The shape of the first substrate 7a may be the same as that of the second substrate 7b.

A method of applying the coating liquid R to the substrates 7a and 7b placed on the stage 31 in this manner is as follows. As shown in FIGS. 2 and 3, the sheet-shaped first substrate 7a and the sheet-shaped second substrate 7b are arranged adjacent to each other along the moving direction, and the applicator 10 is placed on the first substrate. Horizontally move from the substrate 7a to the second substrate 7b, and continuously apply the coating liquid R from the first substrate 7a to the second substrate 7b without discontinuity from the ejection port 16 ( It is discharged from the slit 15). A specific example of the coating method will be described later.

In the embodiment shown in FIG. 2, two substrates 7 (7a, 7b) are arranged on the stage 31. As shown in FIGS. 8, 9, and 10 described later, the stage 31 is , and may be configured to have a width that allows three or more substrates 7 to be placed.

[About the application method]
A specific example of a coating method performed by the coating device 5 having the above configuration will be described. This coating method includes a preparation process, a liquid application process, and a coating process.

In the preparation step, the sheet-shaped first substrate 7a and the sheet-shaped second substrate 7b are arranged adjacent to each other along the movement direction on the stage 31 (see FIG. 2). As a result, the end portion 51 on the application start side, which is a part of the second substrate 7b, is brought into contact with one side of the first substrate 7a.

In the liquid applying step, the coating liquid R discharged from the discharge port 16 of the applicator 10 is applied to the coated surface 8 of the first substrate 7a. This process is called "liquid application". Before applying the liquid, the pressure of the coating liquid R in the applicator 10 is adjusted to a negative pressure with respect to the atmospheric pressure. This adjustment is performed by the pressure regulator 42 . As shown in FIGS. 2 and 4, the discharge port 16 of the applicator 10 is positioned above the first substrate 7a and brought to a stopped state. FIG. 4 is an explanatory view of the stage 31, the substrates 7a and 7b, and the applicator 10 of FIG. 2 viewed from the side. In the stopped state, the application liquid R is additionally supplied to the applicator 10 (reservoir 14) from a pump (not shown). By this supply, a small amount of the coating liquid R is discharged from the discharge port 16, and the liquid is applied to the first substrate 7a (see FIG. 4). By applying the liquid, a bead Ra of the coating liquid R is formed between the tip surface 13 of the applicator 10 and the coated surface 8 of the first substrate 7a.

In FIG. 2, the liquid is applied to the first substrate 7a in a range equal to or larger than the dimension Wb in the width direction of the second substrate 7b. That is, the widthwise dimension Wa of the bead Ra formed on the first substrate 7a is equal to or greater than the widthwise dimension Wb of the second substrate 7b (Wa≧Wb). In this embodiment, a bead Ra is formed between the ejection port 16 and the first substrate 7a over the entire widthwise length of the ejection port 16 . For this reason, the widthwise dimension Wc of the first substrate 7a is larger than the widthwise dimension Wb of the second substrate 7b (Wc≧Wb), and the widthwise dimension (Wa) of the ejection port 16 is larger than the widthwise dimension Wb of the second substrate 7b. (Wc≧Wa). Summarizing the dimensions in the width direction, Wc≧Wa≧Wb. From the above, the liquid application process is completed.

When the liquid applying process is finished, the coating process is started. That is, relative movement between the stage 31 and the applicator 10 is started (see FIG. 5). In this embodiment, the applicator 10 is moved. Even while the applicator 10 is being moved, the pressure of the coating liquid R in the applicator 10 is continuously adjusted to a negative pressure with respect to the atmospheric pressure. Due to this movement, the coating liquid R is pulled out from the slit 15 by capillary action (surface tension) between the tip surface 13 and the surface 8 to be coated. Next, the coating liquid R is continuously applied to the second substrate 7b. The movement of the applicator 10 is performed at a constant speed, and coating is performed continuously from the first substrate 7a to the second substrate 7b without discontinuing the bead Ra. That is, the bead Ra is continuous between the first substrate 7a and the second substrate 7b, and the bead Ra does not disappear between them. When the application liquid R is discharged from the applicator 10, that is, when the application liquid R is consumed by application, the application liquid R is supplied to the applicator 10 from the pump and/or the tank 41 (not shown). Movement of the applicator 10 is continued until the tip surface 13 crosses the terminal end 52 (see FIG. 3) of the second substrate 7b in the direction of movement. From the above, the coating process is completed. As described above, in the coating process, the coating liquid R is discharged from the discharge port 16 from the first substrate 7a to which the coating liquid R is applied to the second substrate 7b without discontinuity of the bead Ra.

[Regarding the coating method of the present embodiment]
As described above, in the coating method of the present embodiment, the sheet-shaped first substrate 7a and the sheet-shaped second substrate 7b are arranged adjacent to each other along the movement direction, and the first substrate 7a to the second substrate 7b from the ejection port 16. As shown in FIG. The above-mentioned "continuously" means that the bead Rb formed between the tip surface 13 of the applicator 10 and the surface 8 to be coated is moved from the first substrate 7a to the second substrate 7b by the movement of the applicator 10. It means that the state continues to be formed between the tip surface 13 and the coated surface 8 as it is during the transition from . That is, the coating method of the present embodiment is performed by discharging the coating liquid R from the discharge port 16 from the first substrate 7a to the second substrate 7b without discontinuing the bead Ra.

According to this coating method, since the second substrate 7b is continuously coated with the bead Ra from the first substrate 7a without interruption, coating is started on the coated surface 8 of the second substrate 7b. It is possible to suppress thinning of the coating film at the edge 51 on the side. As described above, the first substrate 7a serves as an auxiliary substrate (dummy substrate) for coating. That is, the first substrate 7a is not used as a product, and the second substrate 7b is used as a product.
As described above, the film thickness defect range Q (see FIG. 12) from the outer peripheral end of the second substrate 7b is narrowed, and the range that should be the semiconductor chip forming region P, that is, the range in which the coating film is uniform. can be increased.

When the coating of the second substrate 7b is completed, the coated second substrate 7b is taken out from the stage 31, and the uncoated second substrate 7b is placed on the stage 31 adjacent to the first substrate 7a. be done. In this embodiment, the first substrate 7a coated with the coating liquid R is also removed from the stage 31, and the uncoated first substrate 7a is placed on the stage 31 adjacent to the uncoated second substrate 7b. be loaded. In this case, the first substrate 7a is disposable. As a modification, the first substrate 7a may be reused. In this case, the coating liquid R applied to the first substrate 7a is removed by a mechanism (not shown). Also, in this case, the first substrate 7 a may be fixed to the stage 31 .

The coating method of this embodiment is a method of coating by adjusting the pressure of the coating liquid R in the applicator 10 to a negative pressure. Therefore, in the coating method of the present embodiment (see FIGS. 4 and 5), when the coating liquid R discharged from the discharge port 16 adheres to the surface 8 to be coated and the applicator 10 is moved, the tip surface This is a capillary coating method in which the coating liquid R is drawn out from the ejection port 16 to fill the gap K formed between the coating surface 8 and the coating target surface 8 . According to such a capillary coating method, even if the coating liquid R is continuously coated from the first substrate 7a to the second substrate 7b without a break in the bead Ra, the second substrate 7a and 7b passes through the gap between the substrates 7a and 7b. It is possible to prevent the coating liquid R from flowing to the rear surface 53 side (that is, the stage 31 side) of the first substrate 7a and the second substrate 7b. As a result, it is possible to prevent the coating liquid R from adhering to the rear surfaces 53 of the substrates 7a and 7b.

The contour shape of the second substrate 7b in this embodiment (see FIG. 2) is circular. Therefore, the diameter of the second substrate 7b is the dimension Wb in the width direction of the second substrate 7b. The widthwise dimension Wc of the first substrate 7a is equal to or greater than the widthwise dimension Wb of the second substrate 7b (Wc≧Wb). For this reason, the application of the coating liquid R to the first substrate 7a is in a range equal to or larger than the dimension Wb in the width direction of the second substrate 7b, that is, the width direction (Wb) of the surface 8 to be coated of the second substrate 7b. is done in

On the other hand, as shown in FIG. 6, when the widthwise dimension Wc of the first substrate 7a is less than the widthwise dimension Wb of the second substrate 7b (Wc<Wb), the following becomes. The liquid is applied to the first substrate 7a only in a range S1 (referred to as "first range S1") less than the dimension Wb in the width direction of the second substrate 7b. Therefore, in order to apply the liquid to the first substrate 7a, the bead Ra is formed only in the first area S1 of the first substrate 7a, and the areas on both sides of the first area S1 ("second area S2”) does not form a bead Ra. When the applicator 10 is moved to the second substrate 7b side, the bead Ra is continuously formed from the first substrate 7a at the end portion 51 of the second substrate 7b on the application start side. However, in the case of capillary coating, when the applicator 10 (ejection port 16) moves from above the first substrate 7a to the second substrate 7b side, the range of the first range S1 other than the end 51 ( In the "third range S3"), the bead Ra disappears once. Then, as shown in FIG. 7, in the third range S3 where the bead Ra has once disappeared, the coating liquid R is maintained in a state of being slightly exposed from the tip end surface 13 of the ejection port 16 that is elongated in the width direction. be. On the other hand, in the second range S<b>2 where the bead Ra is not formed from the beginning of the ejection port 16 , the coating liquid R is maintained in a state of being drawn inside the applicator 10 from the tip surface 13 . In such a state of the ejection port 16, if the bead Ra is continuously applied from the first substrate 7a to the second substrate 7b without interruption, the amount between the third range S3 and the second range S2 will be increased. The state of the coating liquid R is different at this boundary, and there is a possibility that a portion where a uniform film thickness in the width direction cannot be obtained may occur on the second substrate 7b. In other words, streaks in the movement direction may occur in the coating film of the second substrate 7b.

However, in this embodiment (see FIG. 2), as described above, the widthwise dimension Wc of the first substrate 7a is greater than or equal to the widthwise dimension Wb of the second substrate 7b (Wc≧Wb). For this reason, the coating liquid R is applied to the first substrate 7a within a range equal to or larger than the dimension Wb in the width direction of the second substrate 7b. Therefore, even if the bead Ra once disappears in a region other than the end portion 51 on the coating start side of the second substrate 7b, the coating liquid R is discharged in the same state in the width direction thereafter on the second substrate 7b. , a uniform film thickness can be obtained. Therefore, it is possible to prevent the occurrence of streaks in the movement direction in the coating film of the second substrate 7b.

[About other forms]
The coating method described with reference to FIGS. 2 and 3 is a method in which the two substrates 7a and 7b are arranged on the stage 31. FIG. Alternatively, the coating method may be performed by arranging three or more substrates 7 on the stage 31 in the movement direction (see FIGS. 8 and 9). Furthermore, as another form, the coating method may be performed by arranging a plurality of substrates 7 side by side on the stage 31 in the movement direction and arranging the substrates 7 side by side in the width direction (see FIG. 10). In these cases, the area on which the substrate 7 is placed on the stage 31 is widened. Also, when a plurality of substrates 7 are arranged in the width direction (in the case of FIG. 10), the applicator 10 is configured longer in the width direction than the form shown in FIG.

The application method for each of FIGS. 8 and 10 is as follows. That is, in the coating method, the widthwise elongated ejection port 16 (see FIG. 9) of the applicator 10 that is long in the widthwise direction is brought close to the surface to be coated 8 of the substrate 7, and the applicator 10 and the surface to be coated 8 are brought into contact with each other. In this method, the coating liquid R is discharged from the discharge port 16 onto the surface 8 to be coated while being relatively moved in a direction intersecting (perpendicular to) the width direction. This point is the same as the above embodiment (FIGS. 2 and 3). Also, the preparatory step, the liquid applying step, and the coating step are performed in this order, and the capillary coating is performed in the same manner as in the above embodiment.

8 and 10, the first substrate 7a, which is in the shape of a sheet, and two or more substrates (three substrates in the example shown) follow the first substrate 7a along the moving direction. and the second substrate 7b, which is in the form of a single leaf, are arranged adjacent to each other. Then, the coating liquid R is continuously discharged from the discharge port 16 from the first substrate 7a to the second substrate 7b without interruption of the bead Ra, and two or more (three in the example of the figure) of the second substrate The coating liquid R is continuously discharged from the discharge port 16 without discontinuing the bead Ra between the substrates 7b.

According to this coating method, as in the above embodiment, the second substrate 7b adjacent to the first substrate 7a is continuously coated from the first substrate 7a without a break in the bead Ra. Also between the adjacent second substrates 7b, 7b, the bead Ra is continuously applied without interruption. Therefore, it is possible to suppress thinning of the coating film at the end portion 51 on the coating start side of each coated surface 8 of the second substrate 7b. Also in this coating method, the first substrate 7a serves as an auxiliary substrate (dummy substrate) for coating. That is, the first substrate 7a is not used as a product, and the multiple second substrates 7b are used as products.

Furthermore, in the coating method in the case of FIG. 10, the first substrate 7a and two or more second substrates 7b are arranged adjacent to each other in the movement direction, and the coating method is further carried out as follows. That is, the third substrates 7c are arranged next to each of the second substrates 7b in the width direction. That is, on one side (upper side in FIG. 10) in the width direction of the central row L1, a plurality of (three) third substrates 7c are arranged adjacent to each other in the moving direction after the first substrate 7a, and A plurality of (three) third substrates 7c are arranged next to the first substrate 7a and adjacent to each other in the moving direction on the other side (lower side in FIG. 10) in the width direction of the row L1. . In other words, the first substrate 7a and the first third substrate 7c are adjacent to each other, and the plurality of third substrates 7c and 7c are also adjacent to each other. In this state, the coating liquid R is discharged from the discharge port 16 in order to the six third substrates 7c as well as the three second substrates 7b. As shown in FIG. 10, because of this coating method, the dimension Wc in the width direction of the first substrate 7a is the area where the second substrate 7b and the third substrate 7c are arranged in the width direction. is preferably at least Wd in the width direction (Wc≧Wd). According to this coating method, by moving the applicator 10 by one stroke, it is possible to coat many (nine in the figure) substrates 7 (7b, 7c).

Regarding the stage 31 in the case of FIGS. 8 and 10, the area where the first substrate 7a is arranged is the first area Q1, and the area where the second substrate 7b (and the third area 7c) is arranged is the second area Q1. There are two areas. In the illustrated example, the third substrate 7c and the second substrate 7b have the same shape, but they may have different shapes. In the case of FIG. 10, the substrates 7, 7 aligned in the moving direction are adjacent to each other, but there may be a gap between the second substrate 7b and the third substrate 7c, which are aligned in the width direction. may be adjacent.

Although not shown, in each of the above embodiments, another dummy substrate (auxiliary substrate) may be arranged next to the end side of the second substrate 7b in the movement direction. In this case, the moving direction end 52 of the second substrate 7b (and the third substrate 7c) is brought into contact with the dummy substrate. Then, the application liquid is continuously applied from the second substrate 7b (and the third substrate 7c) to the dummy substrate without discontinuing the bead Ra. In this case, on the second substrate 7b (and the third substrate 7c), it is possible to obtain a coating film of the same constant thickness as during the coating even at the end of the coating end side.

As shown in FIG. 11, the coated surface 8 of the first substrate 7a on the stage 31 and the coated surface 8 of the second substrate 7b are at the same height. In this embodiment, the upper surface of the stage 31 is a horizontal plane, and the first area Q1 and the second area Q2 have the same height. 7b may be a substrate having the same thickness. As a result, the environment (conditions) for coating the first substrate 7a and the environment (conditions) for coating the second substrate 7b become the same. Even if the chamfered portion 55 is provided on the peripheral edge of the second substrate 7b, the height of the planar portion 56 excluding the chamfered portion 55 is the same as the coated surface 8 of the first substrate 7a. Moreover, it is preferable that the chamfered portion is not formed on the first substrate 7a. That is, the surface to be coated 8, which is the front surface of the first substrate 7a, and the side surface 59 surrounding it intersect each other at a right angle.
Further, in the case of FIG. 8 (and FIG. 10), the area where the second substrate 7b (and the third substrate 7c) is arranged is the second area Q2. In this case, the surface to be coated 8 of each of the first substrate 7a and the second substrate 7b (and the third substrate 7c) on the stage 31 has the same height.

〔others〕
The embodiments disclosed this time are illustrative in all respects and are not restrictive. The scope of rights of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope of equivalents to the configurations described in the scope of claims.
For example, the substrates 7 (second substrate 7b and third substrate 7c) may be other than circular.

5: coating device 7: substrate 7a: first substrate 7b: second substrate 7c: third substrate 8: surface to be coated 10: applicator 13: tip surface 16: ejection port 20: moving means 31: stage 42 : pressure regulator 51: end on application start side Q1: first area Q2: second area R: coating liquid Wb: width direction dimension of second substrate Wc: width direction dimension of first substrate

Claims (3)

The widthwise elongated ejection port of the applicator that is long in the widthwise direction is brought close to the surface to be coated of the substrate, and the applicator and the surface to be coated are relatively moved in a direction intersecting the widthwise direction. A coating method performed by discharging a coating liquid from the discharge port onto a surface to be coated,
A sheet-shaped first substrate and a sheet-shaped second substrate are arranged adjacent to each other along the direction of the relative movement,
The second substrate has a shape in which the dimension in the width direction increases from the end of the coating start side toward the coating end side,
the dimension in the width direction of the first substrate is equal to or greater than the dimension in the width direction of the second substrate;
A coating method, wherein the coating liquid is discharged from the discharge port from the first substrate to the second substrate without discontinuity of the bead. When the applicator and the surface to be coated are moved relative to each other in a state in which the coating liquid ejected from the ejection port opened at the tip surface of the applicator adheres to the surface to be coated, the tip surface and the surface to be coated are moved. 2. The coating method according to claim 1, wherein the coating liquid is drawn out from the ejection port to fill a gap formed with the coating surface, and the coating is performed by capillary coating. The widthwise elongated ejection port of the applicator that is long in the widthwise direction is brought close to the surface to be coated of the substrate, and the applicator and the surface to be coated are relatively moved in a direction intersecting the widthwise direction. A coating method performed by discharging a coating liquid from the discharge port onto a surface to be coated,
A sheet-shaped first substrate and two or more sheet-shaped second substrates following the first substrate are arranged adjacent to each other along the direction of the relative movement,
A third substrate is arranged next to each of the second substrates in the width direction, and a plurality of the third substrates are arranged adjacent to each other in the direction of relative movement following the first substrate. in the state
The coating liquid is discharged from the discharge port from the first substrate to the second substrate without discontinuity of the beads, and the coating liquid is discharged without discontinuity of the beads between the two or more second substrates. is discharged from the discharge port,
Ejecting the coating liquid from the ejection port to the third substrate together with the second substrate;
application method.

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