KR20030011463A - Pre-discharging apparatus and method for a slit coater - Google Patents

Abstract

PURPOSE: Apparatus and method for preliminary discharging slit coater are provided to prevent washing solution or application solution having a density different from the slit coater from being attached to the tip end of a discharge nozzle. CONSTITUTION: The preliminary discharging apparatus(P) is used at an atmosphere state before an application work and adapted to preliminary discharge an application solution contained in an application element(21) before the application work while attaching extra application solution onto a rotating roller. In such a preliminary discharge operation, a discharge port(22) of the application element is moved as close as possible to the outer peripheral surface of the roller until there is no surface tension therebetween, and the application solution from the discharge port is attached to the outer peripheral surface of the roller. During rotation of the roller, the application solution is again discharged from the roller so as to be washed and removed.

Description

Pre-discharging apparatus and method for a slit coater

The present invention is, for example, a preliminary discharging apparatus for a slit coater for applying a coating liquid, such as a resist liquid, a developing solution, or a color filter, to a surface of a plate-like object such as a glass substrate or a semiconductor wafer by flowing from a slit-shaped opening, and this preliminary device. It relates to a preliminary discharging method using a discharge device.

When the coating liquid is continuously supplied to the surfaces of a plurality of substrates using a slit coater, the concentration of a part of the coating liquid in the discharge nozzle increases by contact with air during the waiting time between the coating operation and the coating operation. And in this state, if application | coating is continued to the next board | substrate, the phenomenon which the gold generate | occur | produces vertically or the film | membrane cut | disconnects with the high concentration coating liquid arises.

In order to solve the above disadvantages, conventionally, preliminary ejection is performed by immersing the discharge nozzle in a container filled with a cleaning liquid or a coating liquid in the atmosphere, or discarding the coating liquid stuck in the discharge nozzle immediately before application.

In the means for immersing the discharge nozzle in the cylinder filled with the above-described cleaning liquid, the concentration of the coating liquid held in the nozzle is diluted, so that the phenomenon of uneven thickness of the coating film cannot be effectively eliminated. Moreover, in the means which immersed in the coating liquid, the phenomenon that the film | membrane of a leading (place at the time of application) thickens occurs, and uniformity will worsen.

In addition, when preliminary ejection of the coating liquid stuck in the ejection nozzle is discarded immediately before application, the coating liquid adheres extensively to the tip of the ejection nozzle due to the surface tension, resulting in vertical cracking or thickening of the leading film. There is a problem such as occurrence of a phenomenon, and improvement is required.

1 is a view showing an applicator having a preliminary discharging device according to the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

Figure 3 is an overall view of the cleaning tank portion of the preliminary discharging device in cross section.

Figure 4 is a top view of the preliminary discharge device.

<Description of the symbols for the main parts of the drawings>

1: base 2: leg 3: table

4 cylinder unit 5 horizontal plate 6 pin

7 through hole 8 rail 9 moving member

10 air bearing 13 linear scale 14 linear motor

15: magnet rail 16: coil 17: prop

18: guide rail 19: lifting frame 20: servo motor

21 application element 23 feed pump 24 supply pipe

25 return pipe 26 gap sensor 27 amplifier

30 washing tank 31 storage portion 32 side wall portion

33: roller 33a: shaft 34: pulley

35 motor 36 belt 37 shower nozzle

38: manifold 39: piping 39a: valve

40 exhaust cover 41 exhaust port 42 duct

43: recovery hole for the cleaning liquid 44: piping 45: top cover

46 liquid level sensor 47 waste liquid pipe 48 prevention plate

C: Coating device P: Preliminary discharge device T: Recovery tank

W: Substrate L1: Cleaning Liquid L2: Coating Liquid

In order to solve the above problems, the present invention provides a device for preliminarily discharging a slit coater having a slit discharge nozzle, the cleaning tank having a cleaning liquid, and the lower part of the apparatus being immersed in the cleaning liquid in the cleaning tank. The upper surface was equipped with the rotating roller which exposes the discharge nozzle of the said slit coater, and the shower nozzle which removes the coating liquid from the discharge nozzle attached to the surface of this rotating roller.

Further, the preliminary discharging device can be provided with a cleaning liquid circulation path for removing and purifying the cleaning liquid in the cleaning tank and returning the cleaning liquid to the cleaning tank again. With such a configuration, the amount of the cleaning liquid used can be saved.

In addition, a plate is provided above the shower nozzle along the longitudinal direction of the shower nozzle to suppress volatilization of the cleaning liquid in the cleaning tank and prevent scattering of the cleaning liquid sprayed from the shower nozzle toward the rotating roller. .

In addition, when a high volatile organic solvent is used as the cleaning liquid, it dries quickly and does not adversely affect the next preliminary discharge. In addition, by providing an exhaust device above the cleaning tank and exhausting lightly, the surface of the rotating roller cleaned by the shower nozzle can be dried faster.

A preliminary ejection method performed immediately before supplying a coating liquid to the substrate surface using the above preliminary ejection apparatus, wherein the ejection nozzle of the slit coater is brought close to the upper surface of the rotating roller of the preliminary ejection apparatus, and in this state, the ejection nozzle is rotated from the ejection nozzle. When the coating liquid is discharged toward the upper surface of the coating liquid, the coating liquid inside the discharge nozzle can be taken out and good preliminary discharge can be performed. Therefore, a coating film of the same quality can be obtained even by performing a continuous process.

Embodiment

EMBODIMENT OF THE INVENTION Below, embodiment of this invention is described based on an accompanying drawing. 1 is a view showing a coating apparatus provided with a preliminary ejection apparatus according to the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 4 is a top view of the preliminary discharging device.

In FIG. 1, code | symbol C is a coating device and P is a preliminary | backup dispensing apparatus, In this embodiment, although the non-contact type which used the linear motor as the coating device C is shown, a coating device is not limited to this.

First, the coating device C installs the table 3 on the upper surface of the base 1 via the legs 2 having the height adjustment mechanism, and the cylinder unit 4 in the vertical direction on the upper surface of the base 1. And a horizontal plate (5) on the rod of the cylinder unit (4), and a pin (6) for lifting the substrate (W) from the table (3) to the horizontal plate (5). The pins 6 face the through holes 7 of the table 3, and two rails 8, 8 extending in the horizontal direction in the upper surface of the base 1 are provided in parallel. The moving member 9 is arrange | positioned so that the movable member 9 is movable along (8). On the lower surface of the movable member 9, an air bearing 10 as a floating means across the rail 8 is fixed, and the movable member 9 is connected to the rail 8 (by the air bearing 10). Rise from the base 1). In addition, linear scales 13 are provided at both lower ends of the air bearing 10.

Moreover, the linear motor 14 is arrange | positioned on the outer side of each rail 8. The linear motor 14 consists of a magnet rail 15 parallel to the said rail 8, and the plate-shaped coil 16 which fits in the space which this magnet rail 15 forms.

In addition, the support member 17 is provided in the movable member 9, and the guide rails 18 in the up and down directions are provided in the support members 17, and a door shape is formed between the front and rear guide rails 18. The servo motor 20 which raises and lowers the lifting frame 19 is engaged inside the support frame 17, and the lower surface of the lifting frame 19 is provided with a slit nozzle hole. The element 21 is provided, and a liquid feeding pump 23 is fixed to the upper surface of one end of the lifting frame 19, and the liquid feeding pump 23 is connected to the liquid feeding pump 23 from a coating liquid tank via a supply pipe 24a. A coating liquid is supplied and the coating liquid is supplied to the coating element 21 from the liquid feed pump 23 through the supply pipe 24b. In addition, the waste liquid tank, the liquid feed pump 23, and the application element 21 are connected to the air vent pipes 25a and 25b, respectively, and the air draining for filling the coating liquid in the pump 23 and the application element 21 is performed. Is doing.

Moreover, the gap sensor 26 is provided in the side surface of the coating element 21, and this gap sensor 26 and the amplifier 27 are connected by the signal line.

As described above, in order to supply the coating liquid to the surface of the substrate W to be processed, air is blown out from the opening provided on the rail side of the air bearing 10 to move the moving member (from the rail 8 (base 1)). In the state of floating 9, the coil 16 of the linear motor 14 continuously changes the direction of the current in an extremely short period so as to conduct electricity, and moves the moving member 9 to the rail 8 (base 1). While moving along the rail 8 (magnet rail 15) in a non-contact state, the liquid feed pump 23 is driven to supply the coating liquid from the slit nozzle hole toward the surface of the substrate W to be processed. .

Next, the preliminary discharging device P is demonstrated based on FIG. 3 and FIG. The preliminary discharging device P comprises three reservoir portions 31 for storing the cleaning liquid L1, and a side wall portion 32 in which the lower edge circumference portion is joined to the upper edge circumference portion of the reservoir portion 31. The main part is comprised by the water tank 30 and the cylindrical roller 33. As shown in FIG. The roller 33 is formed with metals, such as stainless steel, aluminum, and titanium. In addition, the diameter of the roller 33 shall be 30-100 mm, for example, and the space | interval of the upper surface of the roller 33 and the discharge port of a slit nozzle hole shall be 25-300 micrometers.

As the cleaning liquid L1, a high volatile organic solvent alone having a boiling point of 65 to 120 ° C and a vapor pressure of 12 to 90 mmHg (20 ° C), or a boiling point of 65 to 120 ° C and a vapor pressure of 12 to 90 mmHg (20 ° C). Combined mixed solvents are used.

In the cleaning tank 30, both ends of the cylindrical roller 33 are rotatably supported on both side walls 31a and 31b facing each other in the paper surface vertical direction of the reservoir 31 so as to be rotatably supported. As shown in FIG. 3, the cleaning tank 30 is rotatable in a vertical plane. A pulley 34 is provided at one end of the shaft 33a of the roller 33, and the rotation shaft of the pulley 34 and the motor 35 are coupled to the belt 36 so that the driving force of the motor 35 is applied to the roller ( 33).

On the other hand, the washing | cleaning liquid L1, such as an organic solvent, is filled in the storage part 31 of the washing tank 30, and the lower part of the roller 33 is immersed in this. Moreover, the shower nozzle 37 is provided in one side wall of the side wall part 32. As shown in FIG. The shower nozzle 37 is connected to the recovery tank T via the manifold 38 and the pipe 39 provided with the valve 39a, and is stored in the recovery tank T under the control of the valve 39a. The used cleaning liquid L1 is ejected. In addition, the shower nozzle 37 may be used by one nozzle, and many short nozzles may be connected and used. When a short nozzle is used, it becomes easy to respond to the change of the length of a discharge nozzle, and can simplify maintenance.

Moreover, the exhaust cover 40 which covers the upper surface of the washing tank 30 substantially half (left half of FIG. 3 and FIG. 4) is provided in the upper end part of the side wall in which the shower nozzle 37 was provided. The exhaust cover 40 is provided with an exhaust port 41 protruding to the outside of the cleaning tank 30, and the duct 42 in which the gas containing the cleaning liquid stuck in the cleaning tank 30 is connected to the exhaust port 41. Is discharged through).

Moreover, the recovery hole 43 of the washing | cleaning liquid L1 is provided in the side wall of the bottom part of the storage part 31. As shown in FIG. A pipe 44 provided with a pump P and a filter F is connected to the recovery hole 43, and the cleaning liquid L1 is recovered to the recovery tank T. The cleaning liquid L1 recovered in the recovery tank T is ejected from the shower nozzle 37 back into the cleaning tank 30 through the pipe 39, circulated, and used again.

Moreover, the upper surface cover part 45 which extends along the axis | shaft of the roller 33 by predetermined width is provided in the upper surface of the side wall in the opposite position to the installation position of the shower nozzle 37. As shown in FIG. The liquid level sensor 46 is provided in this upper surface cover part 45, and storage of the washing | cleaning liquid L1 is continued until the liquid level confirms the upper limit level preset. When the upper limit is detected by the liquid level sensor 46, the recovery tank T is recovered to the recovery tank T if recoverable, and if the recovery tank T is not recoverable, the waste liquid tank 47 is shown through the waste liquid pipe 47. Not sent).

In the above, the preliminary ejection by the preliminary ejection apparatus P is performed before application | coating in the standby state between application | coating operations. That is, the operation | movement which discharges the coating liquid in the coating element 21 in advance just before application | coating is performed, attaching the extra coating liquid L2 on the rotating roller 33. As shown in FIG. In this preliminary discharging operation, the discharge port 22 of the coating element 21 is brought close to the circumferential surface of the roller 33 to the extent that surface tension disappears, and the coating liquid L2 from the discharge port 22 is moved to the roller 33. The coating liquid L2 is taken out by adhering to the circumferential surface of the sheet) and the roller 33 rotates, and the coating liquid L2 is washed and removed.

Moreover, the washing | cleaning liquid is ejected from the shower nozzle 37 to the peripheral surface of the roller 33, and the coating liquid L2 which adhered is wash | cleaned. At this time, since the prevention plate 48 is attached above the shower nozzle 37 so as to be pushed toward the roller 25 from the tip of the shower nozzle 37 along the longitudinal direction of the shower nozzle 37, the shower nozzle 37 It is possible to prevent scattering or volatilization of the cleaning liquid sprayed toward the roller 33 from the surface.

Moreover, by evacuating from the exhaust port 41, the washing | cleaning liquid which is a high volatile organic solvent can dry faster from the surface of the roller 33, and there is no problem also in the next preliminary discharge.

As described above, according to the present invention, a cleaning tank filled with a cleaning liquid is provided in the lower part of the rotating roller, preliminary ejection is carried out by bringing the opening of the slit-type ejection nozzle close to the roller, and the discharged coating liquid is annular to the roller. (Iii) Since it adheres to the circumferential surface, contamination of the tip end of the discharge nozzle is prevented, and even though there is contamination of the cleaning liquid by the coating liquid discharged by the preliminary ejection, it is circulated by filtering, so that the dirt of the cleaning liquid is recovered. As a result, the amount of the washing liquid used is drastically reduced.

Moreover, since the roller adheres the coating liquid discharged from the opening of the slit type discharge nozzle to the circumferential surface of the roller and draws the coating liquid from the discharge port by the surface tension of the coating liquid, the discharge nozzle can be uniformly applied. Can be maintained, and the slit coater can be moved to a subsequent coating step in a good state.

Claims (6)

A device for preliminarily discharging a slit coater having a slit-type discharge nozzle, wherein the preliminary discharging device is disposed in a washing tank holding a washing liquid and horizontally in the washing tank, and the lower part thereof is immersed in the washing liquid in the washing tank, and at least the upper end thereof. A rotating roller whose surface is exposed to allow the discharge nozzle of the slit coater to be accessible, and a shower nozzle which sprays the cleaning liquid toward the surface of the rotating roller to remove the coating liquid from the discharge nozzle attached to the surface of the rotating roller. Preliminary discharge device of the slit coater, characterized in that. The slit coater preliminary ejection apparatus according to claim 1, wherein the preliminary ejection apparatus includes a rinsing liquid circulation path for removing and purifying the rinsing liquid in the rinsing tank and returning it to the rinsing tank. The preliminary discharging device of the slit coater according to claim 1 or 2, wherein a prevention plate for preventing volatilization and scattering of the cleaning liquid is provided above the shower nozzle in the vicinity of the rotating roller. The preliminary discharging device of the slit coater according to claim 1 or 2, wherein an exhaust port for performing weak exhaust gas is provided in a part of the cleaning tank. A preliminary discharging method performed immediately before supplying a coating liquid to a substrate surface using a slit coater, wherein the preliminary discharging method is a slit on the upper surface of the rotating roller of the preliminary discharging apparatus according to any one of claims 1 to 4. A discharging nozzle of the coater is placed close to each other, and in this state, the discharging liquid is discharged from the discharging nozzle toward the upper surface of the rotating roller. 6. The method of preliminary discharging the slit coater according to claim 5, wherein a high volatile organic solvent is used alone or mixed as the cleaning liquid.