JP4141805B2 - Single wafer coating method - Google Patents

Description

【００３４】
本発明は、実施例のようなポジレジスト液４０をガラス基板４に塗布する工程ばかりではなく、カラーレジスト、黒色レジスト、透明保護膜などの薬液を、液状の状態で塗布して形成する工程に同様に適用することができる。また、移動フレーム１４，１６によってガラス基板４が静止しているノズル６に対して移動するけれども、ガラス基板４が静止して、ノズル６の方が移動するようにすることもできる。
【００３５】
また、捨塗りの際に、ゴム製のロール３２を用いているけれども、金属や合成樹脂など、他の材料であってもよい。ゴムなどの軟質の材料を用いれば、ノズル６に接触しても破損させないようにすることができる。また、ロール３２ばかりではなく、連続したシートを接触させて、液を付着させ、液が付着したシートをそのまま巻取って廃棄するようにすることもできる。また、単にノズル６から塗布液を流出させるだけでもよい。
【００３６】
【発明の効果】
本発明によれば、板材の装着を待つなど塗布を行わない間、スリット状ノズルの吐出口周辺での塗布液の乾燥物付着による塗膜の均一性の悪化を防止することができる。すなわち、塗布を行わない時間が予め設定される基準を超えると、所定の吐出量、吐出時間で、スリット状ノズルから塗布液を流出させ、ノズルの乾燥を防止して清浄度の劣化を防ぐことができる。
また本発明によれば、塗布を行わない時間が６０秒を超えると、スリット状ノズルから０．０００４〜０．００４４ｇ／ｃｍ・ｓの吐出量で、塗布液を４〜１１秒間流出させるので、ノズルの乾燥を防止して清浄度の劣化を防ぐことができる。
【図面の簡単な説明】
【図１】本発明の実施の一形態による塗布に使用するキャピラリコータ２の一部を切り欠いて示す正面図である。
【図２】図１のキャピラリコータ２の左側面図である。
【図３】図１のローラ３２に関連する部分の構成を示す簡略化した正面断面図の一例である。
【図４】図１および図２のキャピラリコータ２で捨塗りを行う工程図、およびタイムチャートの一例である。
【符号の説明】
２ キャピラリコータ
４ ガラス基板
６ ノズル
６ａ スリット
１０ 吸着テーブル
１４，１６ 移動フレーム
２２，２８ 昇降機構
２４ タンク
３０ 液面センサ
３２ ローラ
４０ 薬液[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet coating method for forming a coating film on a surface of a sheet material in a sheet-fed manner.
[0002]
[Prior art]
Conventionally, in the electronic component industry and the optical component industry, many processes for forming a coating film on the surface of various plate materials have been provided. For example, color filters used for color display in liquid crystal display devices are produced by repeatedly applying various chemicals such as photoresist on a glass substrate. In this sense, precision coating technology is the most important. It can be said that it is an elemental technology.
[0003]
A typical example of such a chemical solution coating apparatus is a spin coater. The spin coater rotates the plate at high speed around the axis perpendicular to the surface, drops the chemical to be applied near the center of rotation, and uses the centrifugal force and the surface tension of the chemical to accurately form a thin film of the chemical. There is an advantage that can be.
[0004]
On the other hand, a method using a die coater that directly applies a thin film by precisely extruding a chemical solution to be applied from a slit-like nozzle and placing the solution on a surface to be applied has also been proposed. Furthermore, a method of using a capillary coater in which a surface to be coated is directed downward, a slit-like nozzle is directed upward, and a chemical solution is allowed to flow out between the slits is proposed (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2001-62370 [0006]
[Problems to be solved by the invention]
Due to advances in production technology and materials, as well as development of demand, liquid crystal display devices have become larger screens year by year, and the color filters used therefor are also becoming larger.
[0007]
Also, in the manufacture of flat elements such as liquid crystal display elements, it is possible to form a large number of screens on a large substrate at the same time. From the viewpoint of improving productivity and reducing costs, a large number of substrates used during production are required. The area trend is expected to continue.
[0008]
A liquid crystal display is produced by repeating application of a large number of chemicals such as a resist, a coloring material, and a protective film and pattern formation. Conventionally, a coating apparatus having a spin coater as an element has been used to form these coating films. However, when a spin coater is used for applying a chemical solution to such a large substrate, 90% or more of the expensive chemical solution is used. As a result, the cost is lost. In addition, the chemicals to be applied are usually those in which solid components such as resins and pigments are dissolved / dispersed with a solvent, and the dried product derived from the scattered chemicals reattaches on the coating and causes defects on the product. There are also problems that occur. Further, when the glass substrate is enlarged, it is difficult to manufacture a device that requires high-speed rotation such as a spin coater. Thus, it can be said that the spin coater has a limit as a coating apparatus used for manufacturing a member for a liquid crystal display device whose area is remarkably increased.
[0009]
On the other hand, in the capillary coater, a narrow slit that causes capillary action is formed in the nozzle so as to extend long in the width direction of the plate material to be coated. Various chemicals that serve as coating liquids rise against gravity due to capillary action and static pressure through slit-like gaps. The applied chemical solution is dried to form a solid film.
[0010]
Production using a glass substrate such as a liquid crystal display element needs to be performed by a single wafer method (one by one), and there is a process of mounting a plate material to be applied to a device and a process of detaching a plate material from the device from the device. . On the other hand, in production in a factory, it is inevitable that a waiting time of several minutes to several tens of minutes due to lot switching and various troubles occurs. The coater must be assumed to operate intermittently.
[0011]
On the other hand, the chemical solution applied to the glass substrate generally contains a large amount of an organic solvent. For this reason, when exposed to air in a stationary state for a long time, it is assumed that the solvent volatilizes from the surface of the chemical solution, thereby increasing viscosity or solidifying, thereby inducing application failure. Such a risk of poor coating is a serious concern particularly in a capillary coater having a long slit-like nozzle having an opening above. That is, since the cleanliness of the nozzle determines the quality of the coating film, and hence the quality of the product (for example, color filter, liquid crystal display element), it is required to keep the cleanliness of the nozzle always good.
[0012]
The present invention relates to a single wafer coating method using a capillary coater. More specifically, the present invention relates to a single wafer coating method that maintains the cleanliness of the nozzle of the capillary coater.
[0013]
[Means for Solving the Problems]
In the present invention, an upward slit-like nozzle is arranged on the lower surface side of a horizontally oriented plate material, and the coating liquid is caused to flow out by static pressure from the slit-like nozzle, and the plate material and the slit-like nozzle are moved relative to each other. , A sheet coating method for forming a coating film on the lower surface,
Single-sheet coating, characterized in that the coating liquid is allowed to flow out from the slit-shaped nozzle at a predetermined discharge amount and discharge time when the time during which the slit-shaped nozzle is not applied to the plate material exceeds a preset reference Is the method.
[0014]
According to the present invention, in the single-wafer coating method, an upward slit-like nozzle is arranged on the lower surface side of the plate material in a horizontal posture, and the coating liquid is caused to flow out from the slit-like nozzle by static pressure, and the plate material and the slit shape A capillary coater that forms a coating film on the lower surface by relatively moving the nozzle is used. Since the plate material is applied one by one, the application cannot be performed while the plate material is being mounted or removed. While the coating is not performed, the coating liquid stays in the slit of the nozzle and tends to solidify over time, but if the time during which the slit-shaped nozzle is not applied to the plate exceeds a preset reference , Since the coating liquid is allowed to flow out from the slit-like nozzle with the discharge amount and the discharge time, it is possible to prevent the nozzle from being dried and to prevent deterioration of the cleanliness.
In the present invention, an upward slit-like nozzle is disposed on the lower surface side of the plate material in a horizontal posture, and the coating liquid is caused to flow out of the slit-like nozzle by static pressure, so that the plate material and the slit-like nozzle are relatively moved. A sheet-fed coating method for forming a coating film on the lower surface,
The sheet-fed coating method is characterized in that the coating liquid is allowed to flow out from the slit-shaped nozzle at a predetermined discharge amount and discharge time when the time during which the application to the plate material from the slit-shaped nozzle is not performed exceeds 60 seconds. .
In the present invention, an upward slit-like nozzle is disposed on the lower surface side of the plate material in a horizontal posture, and the coating liquid is caused to flow out of the slit-like nozzle by static pressure, so that the plate material and the slit-like nozzle are relatively moved. A sheet-fed coating method for forming a coating film on the lower surface,
When the time during which the slit nozzle is not applied to the plate material exceeds a preset reference, the coating liquid is applied for 4 to 11 seconds at a discharge amount of 0.0004 to 0.0044 g / cm · s from the slit nozzle. This is a sheet coating method characterized in that it is allowed to flow out.
In the present invention, an upward slit-like nozzle is disposed on the lower surface side of the plate material in a horizontal posture, and the coating liquid is caused to flow out of the slit-like nozzle by static pressure, so that the plate material and the slit-like nozzle are relatively moved. A sheet-fed coating method for forming a coating film on the lower surface,
When the time during which the slit nozzle is not applied to the plate exceeds 60 seconds, the coating liquid is allowed to flow out from the slit nozzle at a discharge rate of 0.0004 to 0.0044 g / cm · s for 4 to 11 seconds. Is a sheet coating method characterized by the following.
According to the present invention, the coating liquid stays in the slits of the nozzles while not being applied, and tends to solidify over time, but when the time during which the slit-like nozzles are not applied to the plate exceeds 60 seconds. Since the coating liquid is allowed to flow out from the slit nozzle at a rate of 0.0004 to 0.0044 g / cm · s for 4 to 11 seconds, it is possible to prevent the nozzle from being dried and to prevent deterioration of cleanliness.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show a schematic configuration of a capillary coater 2 used in a single wafer coating method as an embodiment of the present invention. 1 is a front view, and FIG. 2 is a left side view. The capillary coater 2 is used to form a coating film of a chemical solution such as a resist on the glass substrate 4. The glass substrate 4 has a size of about 1100 mm × 1250 mm, for example, and the color filter manufacturing process includes a process of forming a coating film on one surface with a thickness of 0.5 to 2 μm. The nozzle 6 is disposed in the base frame 8 so that the slit 6a having a certain width opens upward, and can apply a chemical solution that rises and flows out from the slit 6a to the lower surface of the glass substrate 4.
[0016]
The glass substrate 4 on which the chemical solution is applied is held on the surface of the suction table 10 by vacuum suction or the like. The suction table 10 is rotatable around a rotary shaft 12 whose axis is horizontal, and sucks the glass substrate 4 with the suction surface facing upward, and rotates 180 ° so that the glass substrate 4 is on the lower side. Moving frames 14 and 16 are provided at both ends in the axial direction of the rotating shaft 12 to support the rotating shaft 12. The moving frames 14 and 16 are movable in the left-right direction in FIG. 1 along travel guides 18 and 20 provided on the front side and the back side of the base frame 8, respectively. In the moving frames 14 and 16, linear motors for movement are provided, respectively, and smooth and accurate movement can be performed. When the moving frames 14 and 16 move, the glass substrate 4 sucked on the lower surface of the suction table 10 also moves. The nozzle 6 is disposed at a position facing the lower surface of the moving glass substrate 4. The nozzle 6 is provided with a slit having a certain gap extending from the front side to the back side. The total width of the nozzle 6 is, for example, about 1300 mm when it is assumed that the glass substrate 4 described above is used.
[0017]
The nozzle 6 can be moved up and down by the lifting mechanism 22. When the nozzle 6 is raised, the chemical solution can be applied to the lower surface of the moving glass substrate 4. When the nozzle 6 is lowered, the applied chemical solution can be cut. The chemical liquid is supplied to the nozzle 6 from the tank 24 via the hose 26. The tank 24 can be displaced up and down by an elevating mechanism 28. Above the tank 24, a liquid level sensor 30 for detecting the height of the liquid level of the chemical solution in the tank 24 is provided. A chemical solution is supplied to the tank 24 at a predetermined timing from a separate chemical solution tank.
[0018]
In the capillary coater 2 of the present embodiment, a roller 32, a casing 34, and a drive unit 36 are provided on one end side of the moving frames 14, 16. As indicated by the solid line, when the moving frames 14 and 16 are moving to the other end side of the base frame 8, the glass substrate 4 is attached and detached, and the roller 32 is positioned above the nozzle 6 during that time. Although the nozzle 6 is in a standby state during the attachment / detachment of the glass substrate 4, it is possible to prevent the nozzle 6 from being dried by intermittently discharging the chemical liquid onto the roller 32. At this time, the chemical liquid discharged from the nozzle 6 raises the nozzle 6 and adheres to the surface of the roll 32. A cleaning mechanism for the roll 32 as will be described later is provided in the casing 34, and the chemical liquid from the nozzle 6 can be adhered in a state where the surface of the roll 32 is clean. The roll 32 is rotationally driven by the drive unit 36 so that a clean surface always faces the nozzle 6.
[0019]
The outline of application will be described. First, in the coating substrate mounting step, the glass substrate 4 with the suction surface of the suction table 10 facing upward and the drug film forming surface facing upward is mounted on the suction table 10. The nozzle 6 stands by below. The nozzle 6 is formed with the slit 32 described above, and the slit 32 is filled with a chemical liquid 34 as a coating liquid. In the suction table reversing step, the suction table 10 on which the glass substrate 4 is mounted is rotated by 180 ° around the rotation shaft 12 and reversed. The glass substrate 4 is on the lower side of the suction table 10 and the coating film forming surface is on the lower surface side.
[0020]
During this process, the roll 32 is positioned above the nozzle 6 and can receive the discharge of the chemical liquid 40 from the nozzle 6.
[0021]
In the moving process to the coating start position, the moving frames 14 and 16 shown in FIGS. 1 and 2 move including the suction table 10 that sucks the glass substrate 4 downward, and one end to start coating on the glass substrate 4. Moves until it reaches a position directly above the nozzle 6. In the liquid contact process, the nozzle 6 is raised, and the distance between the surface of the glass substrate 4 and the tip of the nozzle 6 is set to 20 to 40 μm. The tank 24 is moved up and down by an elevating mechanism 28 shown in FIG. 2 to adjust the height of the liquid surface of the chemical solution 34 to the height of the lower surface of the glass substrate 4. As a result, the chemical liquid 34 flows out from the opening of the nozzle 6 by static pressure, contacts the lower surface of the glass substrate 4, and is in contact with the liquid.
[0022]
In the coating process, following the liquid contact, the nozzle 6 and the tank 24 are lowered so that a distance of about 150 to 300 μm is generated between the glass substrate 4 and the nozzle 6. At this time, the liquid level in the tank 24 is adjusted to be the height of the tip of the nozzle 6.
[0023]
Next, the movement of the suction table 10 is resumed. As the steady coating speed, about 2 to 3 m / min is selected, but in some cases, it may be higher.
[0024]
By the movement of the suction table 10, the surface of the glass substrate 4 moves relative to the tip of the nozzle 6, and the chemical liquid 34 is supplied to the surface of the glass substrate 4 through the slit 32. In a steady state, a very stable supply is realized and a uniform film thickness is obtained.
[0025]
In the coating end process, the suction table 10 moves in the reverse direction, and in the suction table reversal and substrate unloading process, the suction table 10 reverses around the rotation shaft 12 to stop the suction of the glass substrate 4 on the upper side, The glass substrate 4 on which the chemical liquid has been applied is taken out.
[0026]
By mounting the next glass substrate 4, the process returns to the coating substrate mounting step. In this process, the roller 32 also moves together with the suction table 10, returns to a position above the nozzle 6, and can receive the chemical liquid 40 discharged from the nozzle 6.
[0027]
FIG. 3 shows configurations of the roller 32, the casing 34, and the drive unit 36 of FIG. The roller 32 is formed of a rubber material such as EPDM having a diameter of about 30 mm, for example. With respect to the rotation direction of the roller 32, the tip of the squeegee 50 contacts the outer peripheral surface of the roller 32 on the downstream side of the portion where the chemical solution from the nozzle 6 adheres, and the chemical solution adhering to the surface of the roller 32 is scraped off. . Further, the surface wave of the roller 32 and the surface cleaned and cleaned by the cleaning mechanism 52 make a round and turn to the position immediately above the nozzle 6 again. When performing the coating, the nozzle 6 is raised to a position where the chemical liquid can be applied to the surface of the roller 32 by the lifting mechanism 22 of FIG.
[0028]
FIG. 4 shows an example of the step (a) for performing the painting and the timing (b). The nozzle 6 is in a standby state after the application end process and before the start of application of the movement process to the application start position. During this time, replenishment of the chemical solution 40 into the tank 24 is performed. As shown in FIG. 4 (a), disposal is also performed between the end of application and the start of application.
[0029]
As shown in FIG. 4B, a time of about 5 seconds is required between the movement to the application start position and the liquid contact, and the application process requires a time of about 20 seconds. Further, in the liquid separation step, it takes about 5 seconds, and after liquid separation, it takes about 20 seconds until the next liquid contact.
[0030]
Examples of the present invention will be described below, but the present invention is not limited thereto.
[0031]
Example A positive photosensitive resist (manufactured by Clariant: AZTFP-310K) was used, and a coating test was continuously performed on a glass substrate using a capillary coater manufactured by Hirano Techseed. During this time, the coating was performed under the conditions shown in Table 1 during standby.
[0032]
After the application is complete, pre-bake at 90 to 120 degrees, remove the solvent, and then perform reflected illumination of the sodium lamp and visual observation using transmitted light to check for uneven coating due to a decrease in the cleanliness of the slit nozzle. Observed.
[0033]
[Table 1]

[0034]
The present invention is not only applied to the step of applying the positive resist solution 40 to the glass substrate 4 as in the embodiment, but also to the step of applying and forming a chemical solution such as a color resist, a black resist, a transparent protective film in a liquid state. The same can be applied. Further, although the glass substrate 4 is moved relative to the stationary nozzle 6 by the moving frames 14 and 16, the glass substrate 4 can be stationary and the nozzle 6 can be moved.
[0035]
Further, although the rubber roll 32 is used at the time of disposal, other materials such as metal and synthetic resin may be used. If a soft material such as rubber is used, it can be prevented from being damaged even if it contacts the nozzle 6. Further, not only the roll 32 but also continuous sheets can be brought into contact with each other to adhere the liquid, and the sheet with the liquid adhered can be wound and discarded as it is. Alternatively, the coating liquid may simply be flowed out from the nozzle 6.
[0036]
【The invention's effect】
According to the present invention, it is possible to prevent deterioration of the uniformity of the coating film due to adhesion of the dried coating liquid around the discharge port of the slit-like nozzle while coating is not performed such as waiting for mounting of the plate material. That is, when the time during which application is not performed exceeds a preset standard, the application liquid is allowed to flow out from the slit-like nozzle with a predetermined discharge amount and discharge time, preventing the nozzle from drying and preventing deterioration of cleanliness. Can do.
Further, according to the present invention, when the time during which coating is not performed exceeds 60 seconds, the coating liquid flows out from the slit-shaped nozzle at a discharge amount of 0.0004 to 0.0044 g / cm · s for 4 to 11 seconds. It is possible to prevent the nozzle from being dried and to prevent deterioration of cleanliness.
[Brief description of the drawings]
FIG. 1 is a front view showing a part of a capillary coater 2 used for coating according to an embodiment of the present invention.
FIG. 2 is a left side view of the capillary coater 2 of FIG.
FIG. 3 is an example of a simplified front sectional view showing a configuration of a portion related to the roller 32 of FIG. 1;
FIG. 4 is an example of a process chart and a time chart for performing coating with the capillary coater 2 of FIGS. 1 and 2;
[Explanation of symbols]
2 Capillary coater 4 Glass substrate 6 Nozzle 6a Slit 10 Suction table 14, 16 Moving frame 22, 28 Lifting mechanism 24 Tank 30 Liquid level sensor 32 Roller 40 Chemical liquid

Claims (4)

An upward slit nozzle is arranged on the lower surface side of the plate material in a horizontal posture, the coating liquid is caused to flow out from the slit nozzle by static pressure, and the plate material and the slit nozzle are moved relative to each other on the lower surface. A sheet-fed coating method for forming a coating film,
Single-sheet coating, characterized in that the coating liquid is allowed to flow out from the slit-shaped nozzle at a predetermined discharge amount and discharge time when the time during which the slit-shaped nozzle is not applied to the plate material exceeds a preset reference Method. An upward slit nozzle is arranged on the lower surface side of the plate material in a horizontal posture, the coating liquid is caused to flow out from the slit nozzle by static pressure, and the plate material and the slit nozzle are moved relative to each other on the lower surface. A sheet-fed coating method for forming a coating film,
A single-wafer coating method, wherein when the time during which application to a plate material from a slit nozzle is not performed exceeds 60 seconds, the coating liquid is allowed to flow out from the slit nozzle for a predetermined discharge amount and discharge time. An upward slit nozzle is arranged on the lower surface side of the plate material in a horizontal posture, the coating liquid is caused to flow out from the slit nozzle by static pressure, and the plate material and the slit nozzle are moved relative to each other on the lower surface. A sheet-fed coating method for forming a coating film,
When the time during which the slit nozzle is not applied to the plate material exceeds a preset reference, the coating liquid is applied for 4 to 11 seconds at a discharge amount of 0.0004 to 0.0044 g / cm · s from the slit nozzle. A single-wafer coating method characterized in that it is allowed to flow out. An upward slit nozzle is arranged on the lower surface side of the plate material in a horizontal posture, the coating liquid is caused to flow out from the slit nozzle by static pressure, and the plate material and the slit nozzle are moved relative to each other on the lower surface. A sheet-fed coating method for forming a coating film,
When the time during which the slit nozzle is not applied to the plate exceeds 60 seconds, the coating liquid is allowed to flow out from the slit nozzle at a discharge rate of 0.0004 to 0.0044 g / cm · s for 4 to 11 seconds. Single-wafer coating method characterized by

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