JPH0864521A - Method and device for film formation - Google Patents

Abstract

PURPOSE: To form a more uniform film with high precision and ease, and at low cost. CONSTITUTION: A rotary roller 7 is rotated in clockwise. and, coating liquid 2a sticking to the rotary roller 7 is transported to the upper outside from the upper opening 6a of a coating liquid storage tank. In the state, a substrate 1 is transported to the uppermost part 7a of the rotary roller 7 with gap d. When the substrate 1 touches the coating liquid 2a sticking to the periphery of the rotary roller 7, coating liquid 2b begins to be applied to a coating surface 1a of the substrate 1, and further, the substrate 1 is moved, so that the coating liquid 2b is applied on a coating target area of a specified range on the substrate 1. The substrate 1 is turned upside dawn and fixed to a turntable of a spin coating device, then, the turntable is rotated so that the substrate is rotated. Due to centrifugal force caused by the rotation of the substrate, the coating liquid 2b on the substrate 1 is made to flow, for less nonuniformity in coat; thus, a film of more uniform thickness is formed on the entire surface of the substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming method for forming a thin film on a substrate such as a thin prismatic glass used in a color liquid crystal television, and an apparatus used in this method.

[0002]

2. Description of the Related Art In a color liquid crystal television which is getting larger year by year, a thin film is often used for forming a liquid crystal drive circuit and red, green and blue color filters.

As one of the conventional methods for forming this thin film, there is a spin coating method. This spin coating method discharges a coating liquid onto the center of the substrate on a rotary table directly connected to a motor and spins the substrate. This is a method in which a centrifugal force is generated by rotating the table to uniformly spread the coating liquid on the substrate.

[0004]

By the way, in such a spin coating method, the size of the substrate is large, and the substrate is often rectangular in shape.
Therefore, when the rectangular substrate is rotated, wind is generated near the periphery of the substrate. Then, in the vicinity of the outer peripheral edge of the substrate, since the wind and the peripheral speed at the time of rotation are larger than the central portion, the coating liquid dries faster than the central portion, so that the formed thin film is close to the outer peripheral edge of the substrate. There is a problem that it becomes thicker.

Further, when the coating liquid concentrates near the corners of the substrate due to the surface tension of the coating liquid, the thin film formed on the corners of the substrate becomes thicker, or the coating liquid concentrates near the corners of the substrate. However, there is a problem in that the surface tension is destroyed and the coating liquid flows around to the back surface of the substrate, which causes dust.

Further, in the conventional method, the amount of the coating liquid discharged to the center of the substrate is set to be smaller than the amount required to form a thin film on the substrate so that the coating liquid reaches the entire surface of the substrate evenly. You have to do much more. Therefore, a large amount of expensive coating liquid is wasted, and there is a problem that the cost becomes considerably high.

Various researches and developments have been conventionally performed to solve these problems, but these problems have not been solved to a satisfactory degree. As described above, according to the spin coating method, it is extremely difficult to form a thin film having a uniform thickness widely on the substrate, and the cost is high.

The present invention has been made in view of the above problems, and an object thereof is a thin film forming method and a thin film forming method capable of forming a more uniform thin film with high accuracy, ease and at low cost. An object is to provide an apparatus used in this method.

[0009]

In order to solve the above-mentioned problems, the invention of claim 1 provides a coating step of coating a coating liquid on a predetermined range of a coating surface of a substrate, and a step of coating the coating liquid. And a rotation step of rotating the substrate with the coating surface facing upward.

According to a second aspect of the invention, the coating step is
A step of applying a coating liquid from a lower side of the substrate to a predetermined range of the coating surface with the coating surface of the substrate facing downward, and further inverting the substrate coated with the coating liquid to apply the coating surface of the substrate Is characterized by having a reversing step of directing upward.

Further, in the invention of claim 3, the coating step comprises:
It is characterized in that the rotating roller having the coating liquid adhered to its surface is rotated and the coating surface of the substrate is not brought into contact with the upper portion of the rotating roller.

Further, the invention of claim 4 is characterized in that the coating step is performed by moving the substrate from the front end to the rear end of the substrate with respect to the upper part of the rotary roller.

Further, the invention of claim 5 is characterized in that the substrate is moved in a direction opposite to the circumferential direction of rotation of the rotary roller. Further, the invention of claim 6 is characterized in that the substrate is moved in the same direction as the circumferential direction of rotation of the rotary roller.

Further, the invention of claim 7 is characterized in that the coating step is further carried out by moving the rotary roller from the front end to the rear end of the substrate with respect to the substrate.

Further, the invention of claim 8 is defined by claims 2 to 7.
A thin film forming apparatus used in the thin film forming method according to any one of claims 1 to 4, wherein the substrate applying device applies the coating liquid to the substrate, and the coating liquid applied to the substrate is a thin film having a uniform thickness. At least a coating device is provided, and the substrate coating device has a coating liquid storage tank having an upper opening portion for storing the coating liquid therein, and an upper portion protruding upward from the upper opening portion of the coating liquid storage tank. And at least a rotating roller rotatably disposed in the coating liquid storage tank so that the lower portion is immersed in the coating liquid in the coating liquid storage tank. At least a rotary table for mounting and fixing the substrate and rotating the substrate is provided.

Further, the invention of claim 9 is characterized in that the axial length of the rotary roller is set shorter than the width of the substrate.

Further, the invention according to claim 10 is characterized in that the coating step is a step of coating the coating surface of the substrate upward and coating a coating liquid on a predetermined range of the coating surface from the upper side of the substrate. .

Further, the invention of claim 11 is characterized in that the coating step is carried out by a coating nozzle for discharging a coating liquid without the outlet of the coating nozzle coming into contact with the coating surface of the substrate.

Further, in the invention of claim 12, in the coating step, the substrate is moved from the front end to the coating nozzle with the discharge port of the coating nozzle facing the discharge surface of the substrate. It is characterized in that it is performed by moving it over the edge.

Further, in the invention of claim 13, the coating liquid is once fed to a relatively large rectangular first space extending in a width direction of a predetermined range of the coating surface in the coating nozzle, and the coating liquid is coated. The liquid is further fed through the groove to a relatively small rectangular second space extending in the width direction of a predetermined range of the coating surface in the coating nozzle.

Further, in a fourteenth aspect of the present invention, when the substrate is moved, the position where the discharge ports of the coating nozzles face each other is a predetermined position before the coating end position within a predetermined range of the coating surface. At this time, the feeding of the coating liquid to the first void in the coating nozzle is stopped.

Further, a fifteenth aspect of the present invention is a thin film forming apparatus used in the thin film forming method according to any one of the tenth to fourteenth aspects, wherein the substrate coating device applies the coating liquid to the substrate and the substrate. At least a spin coating device for forming a thin film having a uniform thickness of the coating liquid applied to, the substrate coating device has a substrate nozzle,
The substrate nozzle has a relatively large rectangular first space extending in the width direction of a predetermined range of the coating surface inside the coating nozzle, to which the coating liquid is fed, and the coating inside the coating nozzle. A second small opening formed in a relatively small rectangular shape extending in the width direction of a predetermined area of the surface, the lower end of which is a discharge opening of the same shape.
It is characterized in that it comprises a void and a large number of grooves which are formed in a width direction of a predetermined range of the coating surface with an extremely small cross-sectional area and which communicate the first void and the second void. .

Further, the invention of claim 16 is characterized in that the center of a predetermined range in which the coating liquid is coated on the coating surface of the substrate is set to be substantially the center of the coating surface of the substrate.

[0024]

In the present invention thus constructed, the coating liquid is applied to the entire surface of the substrate and then the centrifugal force generated by rotating the substrate eliminates the uneven coating of the coating liquid on the substrate. As a result, a thin film having a more uniform thickness can be formed as compared with the conventional case where the coating liquid is discharged to the central portion of the substrate and the thin film is formed by spreading the coating liquid on the entire surface of the substrate by centrifugal force. , More easily and with high precision.

Further, by coating the entire surface of the substrate with the coating liquid in advance, it suffices to apply the coating liquid to the substrate in an amount substantially the same as the amount required to form the thin film on the substrate.
Therefore, the amount of wasted coating liquid is reduced, and as a result, the cost is significantly reduced.

Further, the coating liquid can be coated without contact between the coating surface of the substrate and the rotating roller or the coating nozzle, and the electronic parts such as TFTs and color filters bonded to the substrate are damaged. Instead, the coating liquid is applied.

Further, in the present invention, since the coating liquid is applied to the downward coating surface of the substrate from below the substrate, the rotary roller is almost always immersed in the coating liquid. Therefore, the coating liquid attached to the rotating roller is not dried, and dust is prevented from being generated.

Further, in the present invention, since the coating liquid is coated by the coating nozzle, it becomes easy to control the coating amount of the coating liquid. As a result, the excess coating liquid is suppressed, so that the amount of the coating liquid used is reduced.

[0029]

1 is a vertical sectional view showing a substrate coating apparatus of an embodiment of a thin film forming apparatus of the present invention, FIG. 2 is a horizontal sectional view thereof, and FIG. 3 is a schematic view of a spin coating apparatus of this embodiment. FIG.

The thin film forming apparatus of this embodiment comprises a substrate coating device 3 for coating the substrate 1 with the coating liquid 2 as shown in FIGS. 1 and 2, and a coating liquid coated on the substrate 1 as shown in FIG. Two
Spin coating device 4 for converting a into a thin film having a uniform thickness
And a substrate reversing device 5 for vertically reversing the substrate 1 as shown in FIG.

The substrate coating device 3 is provided with a coating liquid storage tank 6 having an upper opening 6a and storing the coating liquid 2, and at least the outer peripheral surface of the coating liquid storage tank 6 is made of metal such as stainless steel. The rotary roller 7 made of resin, rubber, or the like is housed in a state in which at least the outermost uppermost portion 7a thereof is projected upward from the upper opening 6a of the coating liquid storage tank 6 and the other portion is immersed in the coating liquid 2. Has been done. The coating liquid 2 is adapted to adhere to the outer peripheral surface of the rotating roller 7.

The axial length a of the rotary roller 7 is set to a predetermined amount shorter than the width b of the substrate 1 [illustrated in FIG. 5g (b) described later]. The rotary shaft 7b of the rotary roller 7 is rotatably supported by a bearing 8 on the side wall of the coating liquid storage tank 6, and the motor 9 is attached to one end of the rotary shaft 7b.
The rotational driving force of 1 is decelerated and transmitted via the power transmission mechanism 10. Therefore, the rotating roller 7
Is rotated by the rotational driving force of the motor 9. And
By the rotation of the rotary roller 7, as shown in FIG. 2, the coating liquid 2a attached at the coating liquid dipping portion on the outer peripheral surface of the rotary roller 7 is conveyed upward. Further, the substrate 1 is conveyed to the uppermost portion 7a of the rotary roller 7 from a substrate conveying device (not shown) as indicated by an arrow.

The coating liquid storage tank 6 is held in a constant temperature and constant humidity tank 11 so that the coating liquid 2 is maintained in a constant environment.

Further, the substrate coating device 3 is provided with a pump 12, which pumps the coating liquid 2 stored in the coating liquid storage tank 13 to the vicinity of the bottom of the coating liquid storage tank 6. There is. The supply of the coating liquid 2 from the pump 12 is not limited to be performed near the bottom of the coating liquid storage tank 6, but may be performed at another portion of the coating liquid storage tank 6, but air or the like is mixed in the coating liquid. To prevent this, it is desirable to supply the coating liquid 2 near the bottom of the coating liquid storage tank 6 as shown in the figure.

Further, at a predetermined position above the coating liquid storage tank 6, a level sensor 14 for detecting the liquid level of the coating liquid 2 and outputting a liquid level detection signal is provided, and the coating liquid from the level sensor 14 is also provided. An electronic control unit 15 for controlling the drive of the pump 12 based on the liquid level detection signal of No. 2 is provided. Therefore, when the coating liquid 2 in the coating liquid storage tank 6 is consumed and the liquid level drops by a predetermined amount, and the level sensor 14 detects this liquid level drop and outputs a liquid level detection signal, the electronic controller 15 Based on this liquid level detection signal signal, the pump 1
2 is driven for a predetermined time, whereby the coating liquid 2 is replenished into the coating liquid storage tank 6 by a predetermined amount.

Two level sensors 14 are provided for detecting the upper limit level and the lower limit level of the liquid level of the coating liquid 2, and the drive time of the pump 12 is determined by the liquid level detection signals from these two level sensors. It can also be controlled.

The spin coating apparatus 4 is shown in FIG.
As shown in FIG. 3, a rotary table 4a for mounting the substrate 7 and a motor 4b for rotating the rotary table 4a are provided. The spin coating device 4 includes a rotary table 4
If it has at least a and a motor 4b,
Any spin coating device used in conventional spin coating methods can be used.

Further, the substrate reversing device 5 includes a vacuum suction table 16 for sucking the substrate 1 and the vacuum suction table 16
The rotary shaft 17 fixed to the
A bearing 19 that is rotatably supported by a bearing 23, and a chamber 23 that supports the tip of the rotary shaft 17 by a bearing 20 and that communicates with a vacuum source 21 and that is hermetically sealed to the outside by a seal 22.
And a pulley 25 fixed to the rotating shaft 17, and a motor 27 that generates a rotational driving force for rotating the pulley 25 via a power transmission mechanism 26. A recess 28 into which a negative pressure for sucking the substrate 1 is introduced is formed on the substrate suction surface 16a side of the vacuum suction table 16, and the vacuum suction table 16 and the rotary shaft 17 have a recess 28 and a chamber 23. A passage hole 29 that communicates with and is formed.

After coating the coating liquid 2B on the substrate 1, the substrate suction surface 16a of the vacuum suction table 16 is moved to the substrate 1
By applying a negative pressure from the vacuum source 21 to the concave portion 28, the substrate 1 is attracted and the motor 2
The rotary shaft 17 is rotated by the rotation driving force of the vacuum chuck 7, and the vacuum suction table 16 is reversed. As a result, the substrate 1 is reversed so that the coating surface 1a of the coating liquid 2b of the substrate 1 faces from the lower side to the upper side. ing.

In order to form a thin film on the substrate 1 by the thin film forming apparatus of this embodiment having the above-mentioned structure, the motor 9 is first driven to rotate the rotary roller 7 clockwise (see FIG. 2) as shown in FIG. 5a. The coating liquid 2a adhering to the rotary roller 7 is conveyed to the outside above the upper opening 6a of the coating liquid storage tank 6 by rotating the coating liquid 2a. In this state, the substrate 1 is moved horizontally from the substrate transfer device toward the uppermost portion 7a of the rotary roller 7 in the circumferential direction of the rotary roller 7, that is, in the left direction (illustrated by an arrow) opposite to the right direction of the uppermost portion 7a. Transport to. In that case, the substrate 1 is conveyed in a state in which the coating surface 1a faces downward and at a position separated from the uppermost portion 7a of the rotating roller 7 by the first predetermined distance c.

As shown in FIG. 5b, the tip of the substrate 1 is located at the position α.
5c, the substrate 1 is conveyed diagonally downward to the left toward the rotating roller 7 as shown in FIG. 5c, and when the tip of the substrate 1 reaches the position β, the substrate 1 is moved leftward and horizontally again. Be transported. When the tip of the substrate 1 reaches the position β, the substrate 1 is separated from the uppermost portion 7a of the outer circumference of the rotating roller 7 by the second predetermined distance d, and the coating surface 1a of the substrate 1 is located at the coating start position 1b. Therefore, it comes into contact with the coating liquid 2a attached to the outer periphery of the rotating roller 7. The size of the second predetermined distance d is set so that electronic components such as TFTs and color filters bonded to the coating surface 1a of the substrate 1 do not come into contact with the rotary roller 7 and are damaged. Generally, it is desirable to set the thickness to about 0.3 to 0.5 mm.

While the rotating roller 7 rotates clockwise, the substrate 1 is held from the uppermost portion 7a of the rotating roller 7 by the second predetermined distance d without contacting the rotating roller 7, that is, in the non-contact state to the left. 5d, the coating liquid 2 is applied to the coating surface 1a of the substrate 1 as shown in FIG.
b is applied. As shown in FIG. 5e, when the front end of the substrate 1 reaches the position γ, the substrate 1 is conveyed diagonally upward to the left of the arrow away from the rotating roller 7 as shown in FIG. At a position where the distance from the uppermost portion 7a is approximately the first predetermined distance c, the substrate 1 is again horizontally conveyed leftward.

In the state shown in FIG. 5f, as shown in FIG. 5g, the coating liquid 2b is applied to a predetermined area of the coating surface 1a of the substrate 1 from the coating start position 1b to the coating end position 1c. In that case, the coating liquid 2b is not applied to the regions of the predetermined width e at the front and rear ends and the regions of the predetermined width f at the left and right ends of the substrate 1, and the coating liquid 2b is applied to the coating surface 1a of the substrate 1.
The center of the coating area in a predetermined range where is applied is located substantially at the center of the coating surface 1 a of the substrate 1. The area of the coating area within a predetermined range on which the coating liquid 2b is coated is equal to the coating surface 1 of the substrate 1.
About 50 to 60% or more of the area of a is desirable, but the area is not limited to this.

Next, the substrate reversing device 5 vertically inverts the substrate 1 so that the coating surface 1a faces upward as shown in FIG. 5h, and then the substrate 1 as shown in FIG. 5i.
Is mounted and fixed at a predetermined position on the rotary table 4a of the spin coating device 4. After that, the motor 4b is driven to rotate the turntable 4a at a predetermined rotation speed, thereby rotating the substrate 1. The rotation of the substrate 1 causes a centrifugal force to act on the coating liquid 2b on the substrate 1, and the centrifugal force causes the coating liquid 2b to flow so that coating unevenness is eliminated and the front surface of the coating surface 1a is removed. The coating liquid 2b spreads and has a more uniform thickness as shown in FIG.
Thin film is formed on the substrate 1.

A test for specifically applying the coating liquid 2 to the substrate 1 was conducted. The dimensions of the substrate 1 used for the test piece are a width b of 360 mm and a length of 460 mm, and the dimensions of the rotating roller 7 are an axial length a of 260 mm, a diameter of 50φ, and a second predetermined distance d of 0.4 mm. The width e of the coating liquid 2b at the front and rear ends of No. 1 and the width f of the coating liquid 2b at the left and right ends of the substrate 1 are both 50 mm, and the conveyance speed and the conveyance direction of the substrate 1 are 2 m / min and right to left (Fig. 5), coating liquid 2
Is a clockwise (in FIG. 5) and 7 rp for an ultraviolet photosensitive resin liquid having a viscosity of 5 cp and 10 cp, and an ultraviolet photosensitive resin liquid having a viscosity of 10 cp for the rotation direction and rotation speed of the rotating roller 7.
In the case of an ultraviolet-sensitive resin liquid having a viscosity of 5 cp and a viscosity of 5 cp, it is counterclockwise (same) and 7 rpm.

As a result of this test, it was found that a thin film having a uniform thickness was formed on the substrate 1 with higher accuracy and more easily, and the consumption of the coating solution was reduced.

As described above, according to the present embodiment, the substrate coating device 3 coats the coating liquid 2 on the coating area of the coating surface 1a of the substrate 1 within a predetermined range, and then the substrate 1 is rotated by the spin coating device 4. Since the coating unevenness is eliminated by the centrifugal force generated as a result and the entire coating surface 1a of the substrate 1 is coated, the coating liquid is discharged to the central portion of the substrate 1 as in the conventional case, and the coating liquid is centrifugally generated. As compared with the case where a thin film is formed by spreading it over the entire surface of the substrate 1, a thin film having a more uniform thickness can be formed more easily and with high accuracy.

Further, according to the present embodiment, before the substrate is set in the spin coating apparatus 4, the coating liquid is pre-coated on the entire surface of the substrate 1 so that the amount necessary for forming a thin film on the substrate 1 is increased. It suffices to apply the same amount of the coating liquid to the substrate 1 as the above. Therefore, the amount of wasted coating liquid can be reduced, and as a result, the cost can be significantly reduced.

Furthermore, according to the present embodiment, the coating liquid 2 is applied without contacting the application surface 1a of the substrate 1 with the rotary roller 7, so that the TFT and color bonded to the substrate 1 The coating liquid 2 can be applied without damaging the electronic components such as the filter.

Further, according to the present embodiment, the coating liquid 2 is applied to the coating surface 1a of the substrate 1 facing downward from below the substrate 1, so that the rotating roller 7 is almost rotated by rotating. Since it is always immersed in the coating liquid 2, the coating liquid 2 is not dried and dust is not generated.

In the above embodiment, the substrate 1 is moved in the direction opposite to the moving direction of the uppermost portion 7a of the rotary roller 7, that is, in FIG.
In FIG. 7, the rotating roller is rotated clockwise when the substrate 1 is conveyed from right to left. As shown in FIG. 7, the substrate 1 is moved in the same direction as the moving direction of the uppermost portion 7a of the rotating roller 7, that is, It is also possible to rotate the rotary roller 7 counterclockwise when the substrate 1 is conveyed from right to left. In that case, the viscosity of the coating liquid 1 is 1
When it is 0 cp or less, the fluidity of the coating liquid 2 is good, bubbles are less likely to be mixed in, and coating unevenness is less likely to occur. However, when the viscosity of the coating liquid 1 is larger than 10 cp, the conveying direction of the substrate 1 and the uppermost portion 7a of the rotating roller 7 are set in order to prevent bubbles from being mixed and to prevent coating unevenness.
It is desirable to set the moving direction of the reverse direction.

Further, as shown in FIG. 8, when applying the coating liquid to the substrate 1, instead of moving the substrate 1, the substrate coating device 3 or the rotary roller 7 is used without moving the substrate 1.
It is also possible to move from the front end to the rear end.

Further, in the above-described embodiment, the axial length a of the rotating roller 7 is set to be shorter than the width b of the substrate, but the axial length a of the rotating roller 7 is set to the substrate width b. May be the same as or more than. In that case,
The coating liquid 2 is applied to the entire surface of the substrate 1. Even when the coating liquid 2 is applied to the entire surface of the substrate 2 in this manner, the effect that the amount of the coating liquid used is smaller than that in the case of forming a thin film by the above-described conventional spin coating method can be obtained.

Further, an appropriate substrate reversing device for reversing the substrate 1 is provided, and the substrate coating device 3, the substrate transfer device, the substrate reversing device 5, and the spin coating device 4 are sequentially arranged to form an automatic substrate coating line. You can also do it.

Further, in the present invention, the substrate reversing device 5 in the above-mentioned embodiment can be omitted.

FIG. 9 is a plan view showing a substrate coating apparatus according to another embodiment of the present invention, FIG. 10 is a partially cutaway front view, FIG. 11 is a right side view of this embodiment, and FIG. It is a figure which shows the coating liquid supply circuit of this Example. The same components as those in the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the above-described embodiment, the coating liquid 2 attached to the rotating roller 7 with the coating surface 1a of the substrate 1 facing downward.
After coating the coating surface 1a, the substrate 1 is turned upside down so that the coating surface 1a is on the upper side. However, in this embodiment, coating is performed by the coating nozzle with the coating surface 1a of the substrate 1 on the upper side. The liquid 2 is applied.

That is, as shown in FIGS. 9 to 12,
The substrate coating apparatus 3 in this embodiment includes a placing table 31 on which the substrate 1 is placed, a moving table 32 for moving the placing table 31, a frame 33 for movably supporting the moving table 32, and a frame for supporting this. A motor 34 provided with 33, a screw rod 36 rotated by a rotational driving force of the motor 34 via a coupling 35, a frame 3
3, a coating nozzle 37 attached so as to be movable up and down, a supply pipe 38 for connecting the coating nozzle 37 and the coating liquid storage tank 6 and feeding the coating liquid 2 in the coating liquid storage tank 6 to the coating nozzle 37, A normally closed solenoid valve 39 having two positions, a cutoff position and a communication position, which are arranged in the feed pipe 38, and an origin sensor 40, which is installed in the frame 33 and detects the initial position of the table 31. A limit sensor 41 installed on the frame 33 for detecting the movement limit of the table 31 and an air supply pump 42 for sending air into the coating liquid storage tank 6 under pressure.

As shown in FIGS. 13 (a) and 13 (b),
The coating nozzle 37 includes the first and second nozzle members 43 and 44.
The above two members are joined to each other. 14
As shown in (a) and (b), the first nozzle member 43 has a relatively deep rectangular first recess 45 and a shallower depth than the first recess 45 formed continuously under the first recess 45. The rectangular second concave portion 46 and the second concave portion 4 located at the lowermost end.
Rectangular third recesses 47 each having substantially the same depth as 6 are formed. Further, the first nozzle member 43 has a large number of grooves 48, 48, 48 that connect the second recess 46 and the third recess 47 to each other.
... are formed.

On the other hand, a coating pipe 38 is connected to the second nozzle member 43 so that the coating liquid is fed thereto.
Two 9,49 are drilled. When the first and second nozzle members 43 and 44 are joined to each other, the coating liquid introducing holes 49 and 49 are both arranged so as to open in the first recess 45 of the first nozzle member 43.

When the first and second nozzle members 43, 44 are joined to each other, the first recess 4
5, a relatively large first void A, a second void B continuously under the first space A, and a third void C open to the outside below the second void B are formed. . Then, the second void B and the third void C have a large number of grooves 4
Only 48, 48 ... Can communicate. Also, the third
The shape of the opening to the outside of the void C is an elongated rectangular shape, and this opening serves as a discharge port for the coating liquid 2.

Bearings 50 and 51 are fixed to the frame 33, and both ends of a screw rod 36 are rotatably supported by these bearings 50 and 51. Further, as shown in FIG. 11, a pair of guide rails 52, 53 is fixedly provided on the frame 33 in the longitudinal direction. On the other hand,
A guide screw member 54 screwed into the screw rod 36 is fixedly provided, and guide members 54 and 56 are engaged with and supported by the guide rails 52 and 53 so as to be movable along the pair of guide rails 52 and 53. , 57 (FIGS. 10 and 11
(Shown in Figure) is fixed.

Further, as shown in FIG. 12, in this embodiment, the electronic control unit 15 includes a motor 34 for rotating the screw rod 36, a vertical movement means 58 for vertically moving the coating nozzle 37, and an air supply. The motor 59 that drives the pump 42, the origin sensor 40, and the limit sensor 41 are connected together. Reference numeral 60 is a filter provided in the feed pipe 38, and this filter 60 is for removing foreign matter in which the coating liquid 2 is mixed.

Next, the operation of this embodiment will be described. In applying the coating liquid 2 to the substrate 1, first, as shown by the solid lines in FIGS. 9 and 10, the table 31 is set to the origin position controlled by the origin sensor 40, and the coating nozzle 37 is set to the high position. . Next, the substrate 1 is placed on the table 3 with its coated surface 1a facing upward.
Set to the predetermined position of 1. Next, by pressing an operation button (not shown), the electronic control unit 15 causes the air supply pump 4 to operate.
The second motor 59 is rotationally driven and the motor 34 is slowly rotationally driven. As a result, the pressure in the coating liquid storage device 6 rises, and the guide screw member 54 tries to move to the left in FIG. Therefore,
As shown in FIG. 15A, the table 31 slowly moves to the left.

As far as the coating start position 1b on the coating surface 1a of the substrate 1 is located directly below the coating nozzle 37, that is, at a position facing the third gap C of the coating nozzle 37,
When the motor 34 is rotationally driven, the electronic control unit 15 switches the solenoid valve 39 to set the solenoid valve 39 to the communication position and drives the vertical movement moving means 58. As a result, the coating liquid 2 in the coating liquid storage device 6 passes through the feed pipe 38 and the coating liquid introduction hole 49 due to the pressure in the coating liquid storage device 6
It flows into the void A. The coating liquid 2 that has flowed into the first gap A
Further flows into the second void B and flows into the first and second voids A and B.
Fill the inside. Further, the coating liquid 2 in the second gap B comes into the third gap C through the many grooves 48. At this time, since the coating liquid almost fills the second void B due to the large number of grooves 48 and then enters the third void C, the coating liquid substantially uniformly enters along the longitudinal direction of the third void C. And then the third
The void C is filled almost uniformly. Further, as shown in FIG. 15 (b), the coating nozzle 37 moves downward, and its tip and coating surface 1
It is set and held at a very small predetermined gap between a and a. As a result, the coating is started on the coating surface 1a of the substrate 1 from the coating start position 1b over the width of the coating region of the coating liquid 2 shown in FIG.

Next, as shown in FIG. 15C, when the solenoid valve OFF position 1d, which is a predetermined distance before the coating end position 1c, comes to a position facing the third gap C of the coating nozzle 37, electronic control is performed. The device 15 turns off the solenoid valve 39 and switches it to the blocking position. As a result, the coating liquid 2 is no longer introduced into the first gap A of the coating nozzle 37. On the other hand, even when the solenoid valve 39 is shut off, the coating liquid 2 remains in the third gap C, so that the coating liquid 2 remaining in the third gap C remains in the solenoid valve off position 1
The coating is applied from d to the coating end position 1c. At this time, the solenoid valve 39 is closed and a new coating liquid 2 is not introduced, but the coating liquid 2 remaining in the third gap C comes to be drawn out to the substrate 1 due to the viscosity of the coating liquid 2 or the like. Will be surely applied.

Thus, as shown in FIG. 15D, the coating liquid 2b is applied to the application area of the application surface 1a of the substrate 1 almost uniformly. Thus, when the coating liquid 2b is coated on the coating region of the substrate 1, the coating liquid 2 is almost completely absent in the third gap C. Moreover, since the new coating liquid 2 is not introduced into the coating nozzle 37 as described above, the coating liquid 2 does not penetrate into the third gap C. As a result, the coating liquid 2 remains only in the first and second gaps A and B and the groove 48, and does not remain in the third gap C.
Therefore, the influence of air on the coating liquid 2 is extremely small.

Next, the coating nozzle 37 is set to the raised position. The movable table 32 is detected by the limit sensor 41 when it reaches a predetermined position (shown by a chain double-dashed line in FIGS. 9 and 10) after passing through the coating nozzle 37, and the detection signal from the limit sensor 41 causes the electronic control unit 15 to operate. The motor 34 is stopped. Next, the substrate 1 thus coated with the coating liquid 2b is
It is picked up from the moving table 32 and placed on the rotary table 4a of the spin coating apparatus 4 in the same manner as shown in FIG. The substrate 1 is the turntable 4a.
With this, the substrate 1 having the coating liquid 2b applied almost uniformly on the entire coating surface 1a is obtained as shown in FIG.

On the other hand, when the substrate 2 is picked up from the moving table 32, a substrate detection sensor (not shown) detects this, and the electronic control unit 15 drives the motor 34 to rotate in the reverse direction by the detection signal from the substrate detection sensor. As a result, the moving table 32 moves toward the origin position and is detected by the origin sensor 40 when the moving table 32 reaches the origin position (shown by the solid line in FIGS. 9 and 10), and a detection signal from the origin sensor 40. Thus, the electronic control unit 15 stops the motor 34.

Next, the new substrate 1 is set at a predetermined position on the table 31 with the coated surface 1a facing upward. After that, the same operation as described above is repeated. In that case, the coating liquid 2b applied to the substrate 1 has newly infiltrated into the third gap C from the groove 48, and is a coating liquid less affected by air.

In the thin film forming method of this embodiment having the above-described structure, the coating liquid 2 is discharged from the elongated rectangular discharge port of the coating nozzle 37 to coat the substrate 1. Therefore, the coating liquid 2 is coated. The amount is easy to control. Therefore, since the excess amount of the coating liquid 2 discharged onto the substrate 1 can be suppressed, the usage amount of the coating liquid 2 can be significantly reduced. In particular,
Since the discharge of the coating liquid 2 is stopped just before the coating end position 1c of the coating region of the coating liquid 2 on the substrate 1, the amount of the coating liquid 2 used can be further reduced. Thereby, the thickness of the thin film formed on the substrate 1 can be further reduced.

Moreover, since the coating liquid 2 is discharged substantially uniformly along the longitudinal direction of the elongated rectangular discharge port of the coating nozzle 37, a thin film having a uniform thickness can be formed over the entire substrate 1.

Furthermore, since the coating liquid 2 applied to the substrate 1 is hardly affected by air, a good coating liquid 2 with little deterioration can be applied to the substrate 1. Thus, the thin film formed according to this embodiment has high quality.

Further, in the above-mentioned embodiment, the coated surface 1 of the substrate 1
Since the coating liquid 2 is applied with a facing down,
Although it is necessary to invert the substrate 1 after applying the coating liquid 2,
In the present embodiment, the coating liquid 1 with the coating surface 1a of the substrate 1 facing up
Therefore, it is not necessary to invert the substrate 1 after applying the coating liquid 2. Therefore, since the step of reversing the substrate 1 can be eliminated, the number of steps can be reduced,
Moreover, the time required for forming the thin film can be shortened.

[0075]

As is apparent from the above description, according to the present invention, the substrate is coated with the coating liquid in a predetermined range of the coating surface of the substrate in advance, and then the substrate is rotated by centrifugal force to generate the substrate. Since the coating unevenness of the coating liquid above is eliminated, a thin film with a more uniform thickness can be obtained compared to the conventional one.
It can be formed more easily and with high accuracy.

Further, by applying the application liquid to the application area of the application surface of the substrate in a predetermined range in advance, it is sufficient to apply the application liquid to the substrate in an amount substantially the same as the amount required to form a thin film on the substrate. Therefore, the amount of wasted coating liquid can be reduced, and as a result, the cost can be significantly reduced.

Furthermore, since the application liquid is applied without contacting the application surface of the substrate with the rotary roller or the application nozzle, the application is performed without damaging the electronic parts such as TFTs bonded to the substrate. The liquid can be applied.

Further, according to the present invention, since the coating liquid is applied to the coating surface of the substrate facing downward from the lower side of the substrate, the rotating roller is almost always immersed in the coating liquid, and Since it does not dry, it is possible to prevent the generation of dust.

Furthermore, according to the present invention, the coating liquid is discharged to coat the substrate, so that the coating amount of the coating liquid can be easily controlled. Therefore, the excess amount of the coating liquid discharged onto the substrate can be suppressed, and the amount of the coating liquid used can be greatly reduced. In particular, since the discharge of the coating liquid is stopped a little before the coating end position of the coating liquid coating area on the substrate, the usage amount of the coating liquid can be further reduced. Thereby, the thickness of the thin film formed on the substrate can be further reduced. Moreover, since the coating liquid is discharged almost uniformly along the longitudinal direction of the elongated rectangular discharge port of the coating nozzle, a thin film having a uniform thickness can be formed over the entire substrate. Furthermore, since the coating liquid applied to the substrate is hardly affected by air, it is possible to apply a good coating liquid with little deterioration to the substrate. Thus, according to the present invention, the thin film can be made thinner and more uniform and of high quality.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view schematically showing a substrate coating apparatus of an embodiment of the thin film forming apparatus of the present invention.

FIG. 2 is a cross-sectional view of the substrate coating apparatus shown in FIG.

FIG. 3 is a diagram schematically showing a spin coating apparatus of this example.

FIG. 4 is a perspective view schematically showing an example of a substrate reversing device used in this embodiment.

FIG. 5a is a diagram illustrating a part of the thin film forming method in this example.

FIG. 5b is a diagram illustrating another part of the thin film forming method according to this embodiment.

FIG. 5c is a view for explaining still another part of the thin film forming method in this example.

FIG. 5d is a diagram illustrating still another part of the thin film forming method according to this embodiment.

FIG. 5e is a diagram illustrating still another part of the thin film forming method according to this embodiment.

FIG. 5f is a view for explaining still another part of the thin film forming method in this example.

FIG. 5g is a diagram showing a substrate coated by the substrate coating apparatus in this example.

FIG. 5h is a view for explaining still another part of the thin film forming method in this example.

FIG. 5i is a view for explaining still another part of the thin film forming method in this example.

FIG. 6 is a diagram showing a substrate coated with a coating liquid according to this example.

FIG. 7 is a diagram showing another modification of the present invention.

FIG. 8 is a diagram showing still another modified example of the present invention.

FIG. 9 is a plan view schematically showing a substrate coating apparatus of another embodiment of the thin film forming apparatus of the invention.

FIG. 10 is a front view showing the substrate coating apparatus of the embodiment shown in FIG. 9 with a part thereof cut away.

11 is a right side view showing the substrate coating apparatus of the embodiment shown in FIG.

12 is a diagram showing a supply control circuit for the coating liquid of the embodiment shown in FIG.

FIG. 13 shows the coating nozzle of the embodiment shown in FIG.
(A) is a front view, (b) is XIIIB-XIIIB in (a)
It is sectional drawing which follows the line.

14 shows a first nozzle member of the coating nozzle shown in FIG. 13, (a) is a front view, and (b) is a XIVB-X in (a).
It is sectional drawing which follows the IVB line.

FIG. 15 is a diagram illustrating a thin film forming method using the substrate coating apparatus shown in FIGS.

[Explanation of symbols]

1 ... Substrate, 1a ... Coating surface, 1b ... Coating start position of coating surface 1a, 1c ... Coating end position of coating surface 1a, 2 ... Coating liquid,
2a ... Coating liquid adhered to the rotary roller 2b ... Coating liquid applied to the substrate 1 ... Substrate coating device 4 ... Spin coating device 4a ... Rotating table 4b ... Motor 5
... Substrate reversing device, 6 ... Coating liquid storage tank, 6a ... Upper opening, 7 ... Rotating roller, 7a ... Top of rotating roller 7, 7
b ... rotary shaft, 8 ... bearing, 9 ... motor, 10 ... power transmission mechanism, 11 ... constant temperature and humidity tank, 12 ... pump, 13 ... coating liquid storage tank, 14 ... level sensor, 15 ... electronic control unit, 31 ... Mounting table, 32 ... Moving base, 33 ... Frame, 34 ... Motor, 36 ... Screw rod, 37 ... Coating nozzle, 38 ... Feeding piping, 39 ... Solenoid valve, 40 ...
Origin sensor, 41 ... Limit sensor, 42 ... Air supply pump, 4
3 ... 1st nozzle member, 44 ... 2nd nozzle member, 45 ... 1st recessed part, 46 ... 2nd recessed part, 47 ... 3rd recessed part, 48 ... Groove,
49 ... Coating liquid introducing hole, 50, 51 ... Bearing, 52, 53 ... Guide rail, 54 ... Guide screw member, 55, 56, 57 ...
Guide member, 58 ... Vertical movement moving means

Claims (16)

[Claims] 1. A coating step of coating a coating liquid on a predetermined range of a coating surface of a substrate, and the substrate coated with the coating liquid,
A method of forming a thin film, comprising: a rotating step of rotating the substrate with the coating surface facing upward. 2. The applying step is a step of applying the coating liquid from a lower side of the substrate to a predetermined range of the coating surface with the coating surface of the substrate facing downward, and further applying the coating liquid. 2. The thin film forming method according to claim 1, further comprising a reversing step of reversing the substrate so that the coated surface of the substrate faces upward. 3. The coating step is performed without rotating the rotary roller having the coating liquid adhered to the surface thereof and contacting the coating surface of the substrate with the upper portion of the rotary roller. 2. The thin film forming method as described in 2. 4. The thin film forming method according to claim 3, wherein the coating step is further performed by moving the substrate from the front end to the rear end of the substrate with respect to the upper portion of the rotating roller. 5. The method of forming a thin film according to claim 4, wherein the substrate is moved in a direction opposite to a circumferential direction of rotation of the rotary roller. 6. The thin film forming method according to claim 4, wherein the substrate is moved in the same direction as the circumferential direction of rotation of the rotary roller. 7. The thin film forming method according to claim 3, wherein the applying step is further performed by moving the rotating roller with respect to the substrate from the front end to the rear end of the substrate. 8. A thin film forming apparatus used in the thin film forming method according to claim 2, wherein the substrate coating apparatus applies the coating liquid to the substrate, and the coating applied to the substrate. At least a spin coating device for making a liquid into a thin film having a uniform thickness, wherein the substrate coating device has a coating liquid storage tank having an upper opening and storing the coating liquid therein, and an upper portion of the coating liquid storage tank. And a rotating roller that is rotatably disposed in the coating liquid storage tank such that the lower portion is soaked in the coating liquid in the coating liquid storage tank while protruding upward from the upper opening. A thin film forming apparatus, comprising at least the spin coating apparatus, comprising at least a rotary table for mounting, fixing and rotating the substrate. 9. The thin film forming apparatus according to claim 8, wherein the rotating roller has an axial length set shorter than a width of the substrate. 10. The thin film according to claim 1, wherein the coating step is a step of coating the coating surface of the substrate upward and coating a predetermined range of the coating surface with the coating liquid from the upper side of the substrate. Forming method. 11. The thin film formation according to claim 10, wherein the coating step is performed by a coating nozzle that discharges a coating liquid without the discharge port of the coating nozzle coming into contact with the coating surface of the substrate. Method. 12. The coating step further comprises moving the substrate from the front end to the rear end with respect to the coating nozzle, with the ejection port of the coating nozzle facing the ejection surface of the substrate. The thin film forming method according to claim 11, which is performed. 13. The coating solution is once fed to a relatively large rectangular first space extending in the width direction of a predetermined range of the coating surface in the coating nozzle, and the coating solution is further passed through a groove to form the coating solution. 13. The thin film forming method according to claim 12, wherein the film is fed to a relatively small rectangular second space extending in a width direction of a predetermined range of the coating surface in the coating nozzle. 14. The inside of the coating nozzle when the position at which the discharge port of the coating nozzle faces this position when the substrate is moved is a predetermined position before the coating end position in the predetermined range of the coating surface. 14. The feeding of the coating liquid to the first vacant space is stopped.
The thin film forming method described. 15. A thin film forming apparatus used in the thin film forming method according to claim 10, wherein the substrate is applied with the coating liquid, and the coating is applied to the substrate. At least a spin coating device for making a liquid into a thin film having a uniform thickness, wherein the substrate coating device has a substrate nozzle, and the substrate nozzle supplies the coating liquid, A relatively large rectangular first space extending in the width direction of a predetermined range of the coating surface and a relatively small rectangular shape extending in the width direction of the predetermined range of the coating surface in the coating nozzle are formed. A second space having a discharge port of the same shape at the lower end and a very small cross-sectional area formed in the width direction of a predetermined range of the coating surface,
A thin film forming apparatus comprising: a plurality of grooves connecting the first void and the second void. 16. A center of a predetermined range in which the coating liquid is applied to the coating surface of the substrate is set substantially at the center of the coating surface of the substrate. 15. The thin film forming method according to any one of 14 above.