JPH02135174A - Method and apparatus for forming film - Google Patents

Abstract

PURPOSE:To form uniform film by applying coating liquid while running a substrate with surface velocity higher than peripheral velocity of a roll to the same direction as the rotating direction. CONSTITUTION:Velocity settings for the peripheral velocity V1 of the coat roll 1 and the running velocity V2 of an adsorbing base plate 6 are executed through a control disk 9 so that the relation of V2 to V1 becomes V2=1.05V1-1.20V1. Successively, the coat roll 1 is driven and also the suitable quantity of the coating solution (a) is supplied on the surface of the coat roll 1 with a squeegee 10. At the same time, by passing the adsorbing base plate 6 fixing the substrate 7 through below the coat roll 1, the coating operation of the upper face of the substrate 7 is completed. Successively, the coated sub strate 7 is taken out and only the adsorbing base plate 6 is returned back to the original position and the next coating operation is repeated.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention applies a solution with poor leveling properties such as a pigment dispersion solution or a resist solution to a substrate such as a glass substrate or a metal substrate in the form of an extremely thin film, for example, a uniform film of 3 μm or less. The present invention relates to a method and apparatus for coating a film to a certain thickness.

(Prior Art) Conventionally, for example, when forming a resist pattern for semiconductor circuit manufacturing, it is necessary to uniformly apply a resist solution to a substrate in the form of a thin film, and a spin coating method is generally adopted as the application method.

(Problems to be Solved by the Invention) However, in this spin coating method, approximately 90% of the coating solution is wasted due to liquid drainage due to rotation, and the viscosity of the coating solution is within a few centipoise, and -Limited to materials with fluidity close to ton flow, when coating on a rectangular glass substrate, the film thickness at the four corners will be thicker than at the center, and as the size of the substrate increases, However, there are problems such as increased in-plane variation in the film thickness of the coating solution.

Printing methods using a roll coater or flexo printing machine can be considered as a way to reduce waste of coating solution, but a uniform film surface cannot be obtained unless the solution has extremely good leveling properties after coating. It was considered impossible to apply solutions with poor leveling properties, such as resists and inks containing dispersed pigments, because they would leave roll marks, plate marks, etc.

Therefore, the present invention provides a method and method which can form an extremely thin uniform film of 3 μm or less on substrates such as positive substrates and metal substrates by reducing waste of the coating solution even with coating solutions having poor leveling properties such as pigment dispersion solutions and resist solutions. The purpose is to provide a device for that purpose.

(Means for Solving the Problems) That is, the present invention is a method of applying a coating liquid onto a substrate in a thin film form through a roll, the roll being rotated at a surface speed higher than the peripheral speed of rotation of the roll. The present invention provides a method for coating a thin film on a substrate, characterized in that a coating liquid supplied to the surface of the roll is applied to the surface of the substrate while the substrate is traveling in the same direction as the rotation direction.

Further, the present invention includes a rotatably supported roll, a motor for rotationally driving the roll, and a motor provided so as to be movable across the bottom of the roll, and for mounting and fixing a substrate to be coated. a substrate fixing plate; a motor for driving the substrate fixing plate; and a control mechanism for respectively controlling the rotational speed of the roll and the traveling speed of the substrate fixing plate;
The present invention provides an apparatus for coating a thin film on a substrate, characterized in that it is equipped with a mechanism for uniformly supplying an appropriate amount of coating liquid to the surface of the roll.

In addition, more preferable results can be obtained when the running speed (surface speed) of the substrate is 5 to 20 times faster than the rotational circumferential speed of the roll.

It is desirable that the coating solution has a viscosity within a specific range in order to form a uniform thin film with a thickness of 3 μm or less. It is somewhat related to the rotation speed when coating, or the rotation speed of the anilox roll when coating by flexographic printing method, but generally 5 to 150
cps. Note that FIG. 2 shows that a good thin film can be obtained when the viscosity is within the shaded range in relation to the shear rate. The data in Figure 2 is based on Fuji Hunt Electronics Technology ■
Using a mixture containing Color Renost, CK-Kai 2 manufactured by Toyo Ink Manufacturing Co., Ltd. and acrylic BK ink (acrylic ink-1) manufactured by Toyo Ink Manufacturing ■, the viscosity was measured using an E-type viscometer at a temperature of 22 ° C.
Coating is done using a micro roller coater (MRC-4
This was done by applying the above solution onto a glass substrate using a 50, manufactured by Thermatronics Trading Co., Ltd.).

The coating solution must be Newtonian fluid, or even if the viscosity is 150 cps or more, it should not be used during coating.
It may also be thixotropic, with a drop to 50 cps or less. Further, when the coating solution is a suspension, the solid content ratio is preferably 40 parts or less. The rubber hardness of the coating roll surface is preferably 30' to 50° (JIS A).

(Function) According to the present invention, a differential system is adopted in which the surface speed of the substrate to be coated is made larger than the rotational peripheral speed of the roll, so that the roll causes slip with the substrate surface through the coating solution, and this causes slipping on the surface of the substrate. 5. Acts as a smoother, even with solutions with poor leveling properties, it becomes thin and uniform. OOOe more than 3
It becomes possible to form a film thickness of 0.000 mm or less.

(Example) The thin film forming method according to the present invention can be applied using a conventional roll coater.
It can be carried out using a modified Fregiso printing machine. Figures 3 (4) and (B) show an example of this, in which a nine cylindrical coat roll I with a rubber plate covered on the entire surface is rotated by a pair of side frames 2VC that are protruded from both sides of the device. It is freely supported. This coat roll 1
The rotation of the roller is driven by a roll drive motor 3 disposed on one side of the roller.

A pair of linear moving guides 5 are provided in the upper part of the apparatus body frame 4 along the longitudinal direction of the apparatus so as to be perpendicular to both ends of the coat roll 1, and a suction surface plate 6 is attached to these linear moving guides 5. It is designed to run on top.

A large number of suction holes 6& are formed on the upper surface of this suction surface plate 6Fi, through which a substrate to be coated (for example, a glass substrate or a metal substrate) 7 is suctioned and fixed, and this substrate is coated together with the suction surface plate 6. It is turned so that it passes across below the roll 1. The suction surface plate 6 is moved by a surface plate drive motor 8 provided below the coat roll 1.

The rotation speed of the coat roll and the traveling speed of the suction surface plate 60 are adjusted by a control panel 9 provided on one side of the frame 4 of the main body of the apparatus. The supply and adjustment of the coating solution to the coating roll 1 is carried out by means of skis 10 provided close to the coating roll 1.

When forming a thin film on the substrate 7 using this device, first, the adsorption constant 1 m 6 (
D Traveling speed vs $v, = 1.05 Vl ~
Set each speed via the control panel 9 so that the voltage becomes 1.20 Vt, and then set the speed as shown in Figure 1 CA)K.
<While driving the coat roll 1, an appropriate amount of the coating solution a is supplied onto the surface of the coat roll 1 using the squeegee 10. At the same time, the suction surface plate 6 on which the substrate 7 is fixed is moved below the coat roll 1 at a predetermined speed (see FIG. 1(B)). In this way, by passing the suction surface plate 6 below the coating roll 1, the coating operation on the upper surface of the substrate 7 is completed (see FIG. 1(e)). Then, the coated substrate 7 is removed, only the suction surface plate 6 is returned to its original position, and the next coating operation is repeated.

FIGS. 4(A) and 4(B) show an example of another coating apparatus according to the present invention, in which a flexo plate 12 is coated as a coating roll, and a second roll 1 is used, and an anilox plate is used correspondingly. A roll 13 and an ink roll 14 are provided. The rest of the structure is substantially the same as the next device shown in FIG. 3 (4), 03).

Therefore, the explanation will be omitted by assigning the same reference numerals.

The operation of forming a thin film on the substrate 7 using this device is the third step.
It is the same as in the case of Figures) and (G)), and first, with respect to the circumferential speed v1 of the anilox roll 13 (or flexo plate 12), the traveling speed of the suction surface plate 60 V! v, =l, Q 5v,
The speeds are set via the control panel 9 so that the voltage is 1.20V1, and then the coat roll 1 is driven as shown in FIG. supply to. At the same time, as shown in FIG. 5(B), the suction surface plate 6 is
At the same time, it is made to run at a predetermined speed toward roll 1. In this manner, the suction substrate 6 is passed under the flexo plate 12, thereby completing the coating operation on the upper surface of the substrate 7 (see FIG. 5C). Then, the coated substrate 7 is removed, only the suction platen 6 is returned to its original position, and the next coating operation is repeated. By using the roll 11 provided with such a flexo plate 12, it becomes possible to partially apply the solution to the substrate.

Example 1 Using the apparatus shown in FIGS. 3(A) and CB), a glass substrate (thickness: 1.1 wm, size: 150 w×
150m) was subjected to thin film coating treatment.

(Conditions) Coater: Micro roller coater, MRC-450
(Manufactured by Thermatronics Trading Co., Ltd.) Roll used: N-B roll (Co9m hardness 40-45O
JIS A) Coat printing pressure 1.7 for glass substrate surface
The proverbial nip printing pressure was applied. At this time, the ratio of the glass substrate surface speed to the roll circumferential speed was 107.5 to 110.0:100.

Coating solution composition: 5MX-acrylic! -1 (Toyo Ink■
)/butyl cellosolve (solvent) = 0.571. Solid content ratio 16 Weight Coating speed (Glass substrate conveyance speed): 4 m/min As a result, average film thickness 0.96 μm with no pinholes (smoothness ±0.036 ttm, number of measurements n = 25, when dry) Just make sure you can't get a thin film.

Example 2 A glass substrate (thickness 1
．． Thin film coating was applied to one fin (size: 200 Akebono x 260 cm).

(Conditions) Coat printing pressure A nip printing pressure of 1.9 mm was applied to the glass surface. At this time, the ratio of the positive substrate surface speed to the roll circumferential speed was 110 to 115:100.

Coating solution: Color resist, CK-Kai 2 (Fuchant・
Manufactured by Electronics Technology ■, solid content: 34% by weight) As a result, the average film thickness is 220pm with no pinholes.
(Smoothness: ±0.0911 m, number of measurements n=25, dry) A thin film was obtained.

(Effects of the Invention) As detailed above, according to the thin film forming method of the present invention, the traveling speed of the substrate to be coated is set to 5% relative to the circumferential speed of the coating roll.
Since the coating process is performed at ~20% speed, shearing force acts between the coating roll, the coating solution, and the substrate to be coated, and the coating roll doubles as a break-in roll, making leveling faster. It has the effect of promoting leveling properties for bad solutions, and has a particle size of 100
Even a suspension with poor leveling in which the following powders are dispersed in s, ooo1 or more is 30. It has become possible to form a thin film of less than OOOO with no pinholes and good smoothness. In addition, each time the coating operation is completed, the coating solution is accurately measured using a squeegee or an anilox roll, and is supplied onto the coating roll.
It is possible to improve film thickness accuracy.

[Brief explanation of the drawing]

Figures 1 (4) to (C) are schematic diagrams showing the process order of the thin film forming method according to the present invention, Figure 2 is a diagram showing the relationship between the viscosity of the coating solution and the rotation speed of the coating roll, and Figure 3 Figure 3 (CB) is a plan view of the apparatus for carrying out the method of the present invention, Figure 3 (CB) is a side view of the apparatus of Figure 3 (A), and Figure 4 (4) is another example of the apparatus according to the present invention. A plan view showing the
3) is a side view of the device in FIG. 4(A), and FIG. 5(4)-(
C) is a schematic diagram showing the process order of the thin film forming method of the present invention. In the figure, J... Coat roll, 2... Side frame, 3... Roll drive motor%, 4... Device main body frame, 5... Linear pin-moving guide, 6...
Suction surface plate, 2... Substrate to be coated, 8... Surface plate drive motor, 10... Suction surface plate, 1... Roll, 12...
...Flexo version, 13...Anilox roll, 14
...Ink roll. Figure 1 Applicant's agent Takehiko Suzue ■ Shear rate (rpm) Figure 4 (A) Figure 4 CB) Figure (A) Figure (B) Figure

Claims (5)

[Claims] (1) A method of applying a coating liquid onto a substrate in the form of a thin film via a roll, the substrate being run in the same direction as the rotational direction of the roll at a surface speed faster than the rotational circumferential speed of the roll. . A method for forming a thin film, comprising applying the coating liquid supplied to the surface of the roll onto the surface of the substrate. (2) The surface speed of the substrate is 5 to
2. The thin film forming method according to claim 1, wherein the method is 20% faster. (3) The thin film coating method according to claim 1, wherein the viscosity of the coating liquid is 5 to 150 cps. (4) The thin film coating method according to claim 1, wherein the coating liquid exhibits Newtonian flow or is thixotropic, with a viscosity that decreases to 150 cps or less during coating. (5) A rotatably supported roll, a motor for rotationally driving the roll, and a substrate fixing member provided so as to be movable across the bottom of the roll for mounting and fixing the substrate to be coated. A board, a motor for driving the substrate fixing plate, a control mechanism for controlling the rotational speed of the roll and the running speed of the substrate fixing plate, and uniformly supplying an appropriate amount of coating liquid to the surface of the roll. What is claimed is: 1. A thin film coating device characterized by comprising a mechanism for