JPH1071358A - Coating nozzle for film forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly coat a substrate with a small amt. of a coating soln. SOLUTION: A coating nozzle 37 consists of first and second nozzle members 43, 44. In such a state that the first and second nozzle member 43, 44 are mutually joined, a first relatively large space A is formed by a first recessed part 45 and the second space B communicating with the lower part of the first space A through grooves 48 is formed by a second recessed part 46 and, further, the third space C continued to the lower part of the second space B to be opened to the outside is formed. The lower end of the third space C is an delivery orifice of a coating soln. 2. The coating soln. sent through supply piping 38 is once stored in the first space 45 and further passed through a large number of the grooves 48, 48... from the first space 45 to be stored in the second space B and furthermore almost uniformly penetrates a third recessed part 47 along the longitudinal direction thereof to be finally delivered from the delivery orifice of the third recessed part 47 almost uniformly along the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a coating nozzle for a thin film forming apparatus for applying a coating liquid to form a thin film on a substrate such as a thin rectangular glass used for a color liquid crystal television. It is.

[0002]

2. Description of the Related Art In a color liquid crystal television which is increasing in size year by year, a thin film is often used to form a liquid crystal drive circuit and red, green and blue color filters.
One of the conventional methods for forming this thin film is a spin coating method. In this spin coating method, a coating liquid is discharged to the center of the substrate on a rotating table directly connected to a motor, and the rotating table is rotated. In this method, a centrifugal force is generated to spread the coating liquid uniformly on the substrate.

[0003]

By the way, in such a spin coating method, the size of the substrate is increased and the shape of the substrate is often square.
Therefore, when the rectangular substrate is rotated, wind is generated near the periphery of the substrate. In the vicinity of the outer peripheral edge of the substrate, since the wind and the peripheral speed during rotation are larger than the central portion, the coating liquid dries faster than the central portion. There is a problem that it becomes thicker.

In addition, when the coating liquid concentrates near the corner of the substrate due to the surface tension of the coating liquid or the like, the thin film formed on the corner of the substrate becomes thicker, or when the coating liquid further concentrates near the corner of the substrate. In addition, there has been a problem that the surface tension is destroyed, and the coating solution wraps around the back surface of the substrate, thereby causing dust.

Further, in the conventional method, the amount of the coating liquid discharged to the center of the substrate is made smaller than that required for forming a thin film on the substrate so that the coating liquid reaches the entire surface of the substrate without unevenness. Must be much more. For this reason, there is a problem that a considerably large amount of expensive coating liquid is wasted and the cost is considerably increased.

[0006] In order to solve these problems, various researches and developments have been conventionally carried out, but these problems have not been sufficiently solved. As described above, in the spin coating method, it is not only extremely difficult to form a thin film having a uniform thickness widely on a substrate, but also the cost is high.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a coating nozzle for a thin film forming apparatus which can apply a coating liquid in a small amount without unevenness on a substrate. It is.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a relatively large first space extending in a longitudinal direction to which a coating liquid is fed, An extended second space, a number of grooves formed along the longitudinal direction, a number of grooves communicating the first space and the second space, and formed continuously from the second space; It is characterized by comprising a relatively small third cavity extending in the longitudinal direction and having a lower end serving as a discharge port.

The invention according to claim 2 is characterized in that the second space is formed in a substantially semicircular or substantially circular cross section. Further, the invention of claim 3 is:
The first and second cavities and the groove are formed of two members, a first and a second nozzle member, which are overlapped with each other.
It is characterized in that it is formed on at least one of the first and second nozzle members.

[0010]

In the coating nozzle for a thin film forming apparatus according to the present invention, the coating liquid is temporarily stored in a relatively large first space, and the second space is formed from the first space through a large number of grooves. The coating liquid is once stored in the second space, and the coating liquid is discharged from the second space through the relatively small third space, so that the application amount of the coating liquid can be easily controlled. This suppresses the discharge of excess coating liquid, thereby reducing the amount of coating liquid used. In addition, the coating liquid that has passed through the large number of grooves is temporarily stored in the second space, so that the coating liquid is uniformly dispersed along the longitudinal direction of the second space, and the dispersed coating liquid is dispersed in the third space.
Since the liquid is discharged through the voids, the coating liquid is discharged more uniformly along the longitudinal direction without being substantially affected by the large number of grooves.

Further, when the supply of the coating liquid into the relatively large first space is stopped, the coating liquid stored in the first space enters the third space by a large number of grooves. After the supply of the application liquid into the first space is stopped, the application is performed by the application nozzle and the application liquid in the third space is discharged. No coating liquid remains. Therefore, the coating liquid remaining in the coating nozzle becomes the coating liquid remaining in the first and second voids and the large number of grooves that are hardly affected by air. As a result, the coating liquid remaining in the coating nozzle is hardly affected by the air, and in the next coating, a good coating liquid with little deterioration due to air is always discharged.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a thin film forming apparatus using a coating nozzle according to an embodiment of the present invention. FIG. 1 is a plan view showing a substrate coating apparatus, and FIG. 3 is a right side view showing the substrate coating apparatus, FIG. 4 is a control circuit diagram of the substrate coating apparatus,
FIG. 5 is a diagram schematically showing a spin coating apparatus of this example.

A thin film forming apparatus using the coating nozzle of this embodiment is composed of a substrate coating apparatus 3 for coating a substrate 1 with a coating liquid 2 as shown in FIGS. 1 to 4, and a substrate coating apparatus 3 as shown in FIG. And a spin coating device 4 for converting the coating liquid 2a applied to the thin film into a thin film having a uniform thickness.

The substrate coating apparatus 3 includes a mounting table 31 on which the substrate 1 is mounted, a moving table 32 for moving the mounting table 31, and a frame 3 for movably supporting the moving table 32.
3. The motor 3 on which the supporting frame 33 is installed
4. The coupling 3 is driven by the rotational driving force of the motor 34.
5, a coating rod 37 rotatably mounted on the frame 33, and a coating liquid 37 in the coating liquid storage tank 6 by connecting the coating nozzle 37 and the coating liquid storage tank 6. Pipe 3 for feeding the coating liquid to the application nozzle 37
8. A normally closed solenoid valve 39 provided with two positions, a shut-off position and a communication position, provided on the feed pipe 38, and an origin which is installed on the frame 33 and detects the initial position of the table 31. Sensor 40, limit sensor 4 installed on frame 33 to detect the movement limit of table 31
1, and an air supply pump 42 for feeding air into the application liquid storage tank 6 by pressure.

As shown in FIGS. 6A and 6B, the application nozzle 37 is formed by overlapping and joining two members, first and second nozzle members 43 and 44. As shown in FIGS. 7A and 7B, the first nozzle member 43 has a first concave portion 45 having a rectangular cross section formed relatively deep and having a predetermined length in the longitudinal direction. A second concave portion 46 having a substantially semicircular cross-section and formed at the lower end in the same length as the first concave portion 45 and a second concave portion 46 located at the lowermost end, and formed in the second concave portion 46. Third recesses 47 each having a rectangular cross section and formed in the longitudinal direction at a depth smaller than the depth and the same length as the first recess 45 are provided. Further, the first nozzle member 43 includes a first recess 45.
A number of grooves 48, 48,...

On the other hand, as shown in FIG.
4 is provided with two application liquid introduction holes 49, 49 to which a supply pipe 38 is connected to supply the application liquid. When the first and second nozzle members 43 and 44 are joined to each other, these application liquid introduction holes 49 and 49 are arranged so as to open to the first recess 45 of the first nozzle member 43.

When the first and second nozzle members 43 and 44 are joined to each other, the first recess 4
5, a relatively large first space A is formed, and a second recess 46 forms a groove 48 in the first space A below the first space A.
A second space B communicating with the second space B is formed.
A third cavity C that opens continuously to the outside below the cavity B is formed. The shape of the opening to the outside of the third space C is an elongated rectangular shape, and this opening serves as a discharge port for the coating liquid 2. Therefore, the coating solution sent through the supply pipe 38 is temporarily stored in the first space 45, and is stored in the second space 46 from the first space 45 through a larger number of grooves 48, 48,. From there, it penetrates almost uniformly along the longitudinal direction into the third concave portion 47, and finally, it is almost uniformly discharged from the discharge port of the third concave portion 47 along the longitudinal direction.

Bearings 50 and 51 are fixed to the Fourem 33, and both ends of the screw rod 36 are rotatably supported by these bearings 50 and 51. Also, as shown in FIG.
The frame 33 includes a pair of guide rails 5 in the longitudinal direction.
2,53 are fixed. On the other hand, a guide screw member 54 screwed to the screw rod 36 is fixed to the movable base 32, and is engaged with the guide rails 52, 53 so as to be movable along the pair of guide rails 52, 53. Guide members 54, 56, 57 (shown in FIGS. 2 and 3) to be supported are fixedly provided.

As shown in FIG. 4, in this embodiment, the electronic control unit 15 includes a motor 3 for rotating a screw rod 36.
4. The vertical movement means 58 for vertically moving the application nozzle 37, the motor 59 for driving the air supply pump 42, the origin sensor 40, and the limit sensor 41 are all connected. Reference numeral 60 denotes a filter provided in the feed pipe 38, and this filter 60 is for removing foreign matters in which the coating liquid 2 is mixed.

As shown in FIG. 5, the spin coating apparatus 4 includes a rotary table 4a on which the substrate 7 is placed and a motor 4b for rotating the rotary table 4a. As the spin coating device 4, any spin coating device used in a conventional spin coating method can be used as long as it has at least a rotary table 4a and a motor 4b.

Next, the operation of the present embodiment thus configured will be described. In applying the coating liquid 2 to the substrate 1, first, as shown by a solid line in FIGS. 1 and 2, the table 31 is set to the origin position controlled by the origin sensor 40, and the coating nozzle 37 is set to a high position. .
Next, the substrate 1 is set at a predetermined position on the table 31 such that the application surface 1a faces upward. Next, by pressing an operation button (not shown), the electronic control unit 15 rotationally drives the motor 59 of the air supply pump 42 and slowly rotates the motor 34. As a result, the pressure in the coating liquid storage device 6 increases, and the guide screw member 54 tries to move leftward in FIG. Therefore, as shown in FIG. 8A, the table 31 slowly moves to the left.

As long as the coating start position 1b on the coating surface 1a of the substrate 1 is just below the coating nozzle 37, that is, at a position facing the third space C of the coating nozzle 37,
When the motor 34 is driven to rotate, the electronic control unit 15 switches the solenoid valve 39 to set it to the communication position and to drive the up / down operation moving means 58. Thus, the coating liquid 2 in the coating liquid storage device 6 flows into the first space A through the supply pipe 38 and the coating liquid introduction hole 49 due to the pressure in the coating liquid storage device 6, and is stored. The coating liquid 2 stored in the first space A penetrates into the second space B in the longitudinal direction through a larger number of grooves 48, 48,.
Is filled in. Further, the coating liquid 2 in the second space B penetrates and fills the third space C almost uniformly along the longitudinal direction. That is, the coating liquid 2 that has entered through the large number of grooves 48 is almost completely filled in the second space B and then enters the third space C.
And penetrates substantially uniformly along the longitudinal direction of the third space C and is substantially uniformly filled in the third space C.

Further, as shown in FIG.
When the coating nozzle 1 moves further to the left and the coating start position 1b on the coating surface 1a of the substrate 1 comes directly below the coating nozzle 37, the coating nozzle 37 moves downward, and the space between the tip and the coating surface 1a becomes extremely large. It is set and held at a small predetermined gap. Thus, the application by the application liquid 2 discharged from the application nozzle 37 is started on the application surface 1a of the substrate 1 from the application start position 1b over the width of the application area of the application liquid 2 shown in FIG.

Next, as shown in FIG. 8C, 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 space C of the coating nozzle 37, the electronic The control device 15 turns off the solenoid valve 39 to switch to the shut-off position. Thus, the application liquid 2 is no longer introduced into the first space A of the application nozzle 37. On the other hand, even if the solenoid valve 39 is shut off, since the coating liquid 2 remains in the third space C, the coating liquid 2 remaining in the third space C is moved to the solenoid valve off position 1.
The coating is applied from d to the coating end position 1c. At this time, although the solenoid valve 39 is closed and new coating liquid 2 is not introduced, the coating liquid 2 remaining in the third space C is drawn out to the substrate 1 due to the viscosity of the coating liquid 2 or the like. 1 is surely applied.

In this way, as shown in FIG.
The application of the application liquid 2a to the application surface 1a is completed. Substrate 1
In this state, as shown in FIG. 9, 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 this case, the coating liquid 2b is not applied to the region of the predetermined width e at the front and rear ends of the substrate 1 and the region of the predetermined width f at the left and right ends, and the predetermined range in which the coating liquid 2b is applied to the coating surface 1a of the substrate 1 Is located substantially at the center of the application surface 1 a of the substrate 1. The area of the application area in a predetermined range to which the application liquid 2b is applied is approximately 50 to 60 times the area of the application surface 1a of the substrate 1.
% Is desirable, but is not limited to this.

When the coating liquid 2a is applied to the coating area of the substrate 1 as described above, the coating liquid 2 has almost disappeared in the third space 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 enter the third space C. Thus, the coating liquid 2 remains only in the first and second cavities A and B and the many grooves 48 and does not remain in the third vacancy C. Therefore, the influence of the air on the coating liquid 2 is extremely small.

Next, the application nozzle 37 is set to the raised position. When the moving table 32 reaches a predetermined position (indicated by a two-dot chain line in FIGS. 1 and 2) after passing through the coating nozzle 37, the moving table 32 is detected by the limit sensor 41, and the electronic control unit 15 is controlled by the detection signal from the limit sensor 41. The motor 34 is stopped.
Next, the substrate 1 thus coated with the coating liquid 2a is picked up from the moving table 32 and placed on the turntable 4a of the spin coating apparatus 4 as shown in FIG. Rotated. Thus,
As shown in FIG. 10, the substrate 1 in which the coating liquid 2a is applied almost uniformly on the entire surface of the coating surface 1a can be obtained.

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 according to a detection signal from the substrate detection sensor. Thereby, the movable table 32 moves toward the origin position, and when the movable table 32 comes to the original position (indicated by a solid line in FIGS. 1 and 2), the origin sensor 4
0, the electronic control unit 15 stops the motor 34 in response to a detection signal from the origin sensor 40.

Next, a new substrate 1 is set at a predetermined position on the table 31 so that the application surface 1a is on the upper side. Thereafter, the same operation as described above is repeated. In this case, the coating liquid 2a applied to the substrate 1 has newly entered the second and third cavities B and C from the groove 48, and is a coating liquid with little influence of air.

In the thin film forming method of the present embodiment configured as described above, since the coating liquid 2 is discharged from the elongated rectangular discharge port of the coating nozzle 37 and coated on the substrate 1, the coating amount of the coating liquid 2 But easy to control. Therefore, since the excess amount of the coating liquid 2 discharged to 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 slightly before the coating end position 1c of the coating area of the coating liquid 2 on the substrate 1, the usage amount of the coating liquid 2 can be further reduced. Thereby, the thickness of the thin film formed on the substrate 1 can be further reduced.

In addition, since the coating liquid 2 is discharged almost 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. In particular, in this example, the coating liquid 2 that has passed through the large number of grooves 48, 48 is temporarily stored in the second concave portion 46, and then uniformly penetrates into the third concave portion 47 along the longitudinal direction. Since the liquid is discharged from the discharge port of the recess 47, a thin film having a uniform thickness can be formed more effectively without being substantially affected by the groove 48.

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 the present example is of high quality.

FIG. 11 is a sectional view showing a coating nozzle 37 according to another embodiment of the present invention.

In the above-described example, the first recess 45 and the second
Although the concave portion 46, the third concave portion 47, and the groove 48 are all provided only in the first nozzle member 43, in this example, as shown in FIG. 11, these concave portions 45, 46, 47 and the large number of grooves 48, Are provided on the first nozzle member 43, and the concave portions 45 ', 46', which have the same shape as the concave portions 45, 46, 47 and the multiple grooves 48, 48,.
47 'and a number of grooves 48', 48 ', ... are also provided in the second nozzle member 44. In that case, the first and second
When the nozzle members 43 and 44 are overlapped, each recess 4
5 ', 46', 47 'and a number of grooves 48', 48 ',.
8,... When the first and second nozzle members 43 and 44 are overlapped with each other, the cavities A and C formed by the first and third recesses 45 and 45 '; 47 and 47' have a substantially rectangular cross section. ,
The void B formed by the second concave portions 46 and 46 'has a substantially circular cross section. Other configurations of this example are the same as those of the above-described example.

The operation and effect of this embodiment are also the same as those of the above-described embodiment.

The recesses 45 ', 46', 47 'and a number of grooves 48', 48 ',... May be provided only in the second nozzle member 44.

[0037]

As is apparent from the above description, according to the coating nozzle for a thin film forming apparatus of the present invention, a coating liquid is temporarily stored in a relatively large first space, and a large number of liquids are stored from the first space. The coating liquid is once stored again in the second space through the groove, and the application liquid is discharged from the second space through the relatively small third space, so that the application amount of the coating liquid can be easily controlled. . Thereby, the discharge of the excess coating liquid can be suppressed, so that the usage amount of the coating liquid can be reduced. In addition, since the coating liquid that has passed through the large number of grooves is temporarily stored in the second space, it can be uniformly dispersed along the longitudinal direction of the second space. The coating liquid can be evenly and uniformly discharged in the longitudinal direction without being substantially affected by the above.

Further, when the coating liquid is not discharged from the coating nozzle, since the coating liquid does not exist in the third space, the coating liquid is hardly affected by air, and a good coating liquid with little deterioration due to air is always discharged. become able to.

[Brief description of the drawings]

FIG. 1 is a plan view showing a substrate coating apparatus using an embodiment of a coating nozzle for a thin film forming apparatus according to the present invention.

FIG. 2 is a front view showing the substrate coating apparatus shown in FIG.

FIG. 3 is a right side view showing the substrate coating apparatus shown in FIG.

FIG. 4 is a diagram illustrating a coating liquid supply control circuit illustrated in FIG. 1;

FIG. 5 is a view schematically showing a spin coating apparatus for forming a thin film.

6A and 6B show the application nozzle of the example shown in FIG. 1, wherein FIG. 6A is a front view, and FIG. 6B is a cross-sectional view taken along line VIB-VIB in FIG.

7 shows a first nozzle member of the application nozzle shown in FIG. 6, (a) is a front view, and (b) is VIIB-VII in (a).
It is sectional drawing which follows the B line.

FIG. 8 is a diagram illustrating a method of forming a thin film on a substrate by a thin film forming apparatus using a coating nozzle in this example.

FIG. 9 is a view showing a substrate on which a coating liquid is applied in a predetermined range by a coating nozzle of this example.

FIG. 10 is a view showing a substrate on which a coating liquid is applied by the spin coating apparatus shown in FIG. 5;

FIG. 11 is a sectional view showing a coating nozzle according to another example of the present invention.

[Explanation of symbols]

DESCRIPTION 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 applied to substrate 1, 3: substrate coating device,
4 ... spin coating device, 4a ... rotary table, 4
b: motor, 15: electronic control unit, 31: mounting table, 32: moving table, 33: frame, 34: motor, 3
6: screw rod, 37: coating nozzle, 38: feed pipe, 39
... Solenoid valve, 40 ... Origin sensor, 41 ... Limit sensor, 42 ... Air supply pump, 43 ... First nozzle member, 44
... second nozzle member, 45 ... first concave portion, 46 ... second concave portion,
47: third concave portion, 48: groove, 49: coating liquid introduction hole, 5
0,51 ... bearing, 52,53 ... guide rail, 54 ... guide screw member, 55,56,57 ... guide member, 58 ... vertical movement moving means, A ... first space, B ... second space, C … The third space

Claims (3)

[Claims] 1. A relatively large first space extending in the longitudinal direction, a second space extending in the longitudinal direction, into which the coating liquid is fed, and a plurality of the first spaces formed in the longitudinal direction. A plurality of grooves communicating the first space and the second space, and a relatively small third space formed continuously from the second space, extending in the longitudinal direction, and having a lower end serving as a discharge port; And a coating nozzle for a thin film forming apparatus. 2. The coating nozzle for a thin film forming apparatus according to claim 1, wherein the second space has a substantially semicircular or substantially circular cross section. 3. A first and a second nozzle member, which are overlapped with each other, wherein the first to third voids and the groove are formed in at least one of the first and the second nozzle members. 3. The coating nozzle for a thin film forming apparatus according to claim 1, wherein