JPH075892Y2 - Roll coater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] This invention is a roll coater for uniformly applying a coating solution, particularly a highly viscous coating solution such as photoresist or polyimide resin, onto the surface of a thin plate substrate. Regarding

[Conventional technology]

An apparatus for applying a high-viscosity coating liquid onto a substrate surface using a roll coater is conventionally disclosed in, for example, Japanese Utility Model Publication No. Sho 59-42133 (invention title "high-viscosity liquid coating apparatus"). There is a device. As shown in the schematic perspective view of FIG. 6, this apparatus brings a coating roll 60 and a doctor roll 62 into contact with each other to form a liquid reservoir 64 on the upper side of the contact portion, and the liquid reservoir 64 High viscosity liquid supply nozzle 66 above 64
The supply nozzle 66 to the coating roll.
60 and the doctor roll 62 are configured to reciprocate along the respective axial directions. In the figure, 68 is a backup roll.

Further, instead of the doctor roll 62 of the apparatus shown in FIG. 6, a doctor bar 82 is brought into contact with the coating roll 80 as shown in FIG. 8, and a liquid pool portion formed on the upper side of the contact portion. There is also known a device in which a supply nozzle 86 is hung above 84 to be reciprocally movable along the axial direction of the coating roll 80. In the figure, 88 is a backup roll.

[Problems to be Solved by the Invention] In the roll coaters shown in FIGS. 6 and 8,
By reciprocating the supply nozzles 66 and 86 along the axial direction of the coating rolls 60 and 80, the coating liquid is stored in the liquid reservoir.
The coating liquid is evenly supplied over the whole of 64 and 84 so that the coating liquid can be uniformly coated on the surface of the substrate p. However, even if the coating liquid is supplied to the liquid reservoirs 64 and 84 while reciprocating the supply nozzles 66 and 86, the coating work is continued by rotating the coating rolls 60 and 80 for a long time. Then, there is a large difference in the viscosity of the coating liquid between the central part of the liquid reservoir and the both ends of the liquid reservoir corresponding to the passage position of the substrate p.

That is, at the center of the liquid reservoir, the coating roll 6
As the coating liquid supplied to that portion is sequentially coated on the surface of the substrate p through the peripheral surfaces of the coating rolls 60 and 80 in accordance with the rotation of 0 and 80, the coating liquid is constantly replaced and the supply nozzle 66 , 86, the viscosity of the coating liquid is maintained substantially constant unless the viscosity of the coating liquid is changed. On the other hand, at both end portions of the liquid reservoir, the coating liquid supplied to that portion is not coated on the substrate p, and when the viscosity of the coating liquid is high, the coating liquid does not flow so much, so that the coating liquid locally flows. However, the coating liquid is not replaced, and particularly near the both ends of the liquid reservoirs 64 and 84, the coating liquid 70 enters the groove 72 formed on the peripheral surface of the coating roll 60, as shown in FIG. Since the liquid is hardly replaced, the solvent in the coating liquid evaporates with the lapse of time, and as a result, the viscosity of the coating liquid becomes higher at both ends of the liquid reservoir.

In this way, if there is a large difference in the viscosity of the coating liquid between the central part of the liquid reservoir and the two end parts of the liquid reservoir, this does not cause much problem when the width dimension of the substrate p to be processed is always constant. When the type of the substrate p is changed and its width is increased, the coating films 74 and 90 applied to the surface of the substrate p
However, there is a problem that the liquid viscosity of No. 1 changes depending on the position in the width direction of the substrate p (direction orthogonal to the transport direction of the substrate p), and a coating film having a uniform film thickness cannot be formed.

Incidentally, in order to promote the exchange of the coating liquid at both end portions of the liquid reservoirs 64, 84, it is necessary to increase the amount of the coating liquid supplied from the supply nozzles 66, 86 more than necessary. However, there are problems such as deterioration of the coating liquid and increase in size of the apparatus.

This invention was made in view of the above-mentioned current situation,
In particular, when applying a high-viscosity coating liquid such as photoresist or polyimide resin to the substrate surface, a roll that can apply a coating liquid of uniform viscosity to the entire substrate surface without causing the problems described above. The technical issue is to provide a coater.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, a roll coater according to the present invention comprises at least one coating roll which is rotatably arranged in parallel to a substrate transport path, and in contact with the coating roll in parallel with the coating roll. At least one doctor disposed so as to be separable and a liquid reservoir formed on the upper side of the contact portion between the doctor and the coating roll, and at least 1 for supplying the coating liquid to the liquid reservoir. In a roll coater, which comprises two coating liquid supply means, the coating liquid supplied to the liquid reservoir is applied to a substrate being conveyed through the coating roll, each of the coating roll and the doctor. The longitudinal direction is inclined with respect to the horizontal plane, and the coating liquid supply means is arranged at a position above the upper end of the substrate being conveyed. It is configured as characterized in that.

[Action]

In the roll coater having the above-described structure, the coating roll and the doctor are arranged so as to be inclined, so that the liquid reservoir formed on the upper side of the contact portion between the coating roll and the doctor is also inclined. Then, since the coating liquid supply means is disposed above the upper end of the conveyed substrate in the inclined liquid storage portion, when the coating liquid is supplied from the coating liquid supply means to one end portion of the liquid storage portion. The coating liquid flows down due to its own weight. In this way, the coating liquid sequentially flows from the high position side to the low position side of the liquid reservoir, so that the coating liquid in the liquid reservoir is constantly exchanged and the coating liquid is spread over the entire longitudinal direction of the liquid reservoir. The viscosity becomes uniform.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

1 to 3 show an embodiment of the present invention.
The drawing is a partial cross-sectional view of the roll coater as seen from the back side, FIG. 2 is a perspective view showing the main parts thereof, and FIG. 3 is a perspective view showing one end portion of the roll coater in a partially broken state.

In these figures, a backup roll 18 is rotatably attached to frames 20 and 20 'in a conveyance path for a substrate p. Above the backup roll 18, a coating roll 10 having circumferential or spiral grooves 58 engraved on the peripheral surface at a predetermined pitch is provided, and a pair of lift plates 22 and 22 'are provided at both ends thereof.
Is rotatably attached to the shaft. Further, a doctor roll 12 is attached to the elevating plates 22, 22 'at both ends thereof in parallel with the coating roll 10 so as to come in contact with and separate from the peripheral surface of the coating roll 10 via sliders 24. The slider 24 includes a pair of horizontal guides 26, 26 '.
Is slidably inserted along them. The force pressing the doctor roll 12 against the coating roll 10 can be adjusted by rotating the bolt 28. The force for pressing the doctor roll 12 against the coating roll 10 can be adjusted by rotating the bolt 28 with an appropriate drive source such as a servomotor.

Further, the coating roll 10 and the doctor roll 12 are
The lifting drive means 30 together with the lifting plate 22 and the frame 20
It can be moved up and down along guides 32, 32 'which are erected on the. The elevating and lowering driving means 30 is arranged on the upper frame 34, and is constituted by a known driving means such as a servo motor and an air cylinder. Further, the coating roll 10 is a rotation driving means (not shown) such as a motor.
And is configured to rotate at a required number of rotations. Incidentally, 36 and 38 in FIG. 3 are the backup roll 18 and the coating roll 10, respectively, in the frame 20.
And a bearing for rotatably supporting the lifting plate 22.

And this roll coater is a coating roll 10,
One end side of each of the doctor roll 12 and the backup roll 18 in the longitudinal direction is made higher than the other end side, and the axial direction of each roll is inclined, for example, about 30 ° with respect to the horizontal plane. Therefore, the liquid reservoir 14 formed on the upper side of the contact portion between the coating roll 10 and the doctor roll 12 is also inclined by about 30 °. Above the high position side of the inclined liquid reservoir 14,
The coating liquid supply nozzle 16 is suspended.
Is connected by a pipe 40 to a pump P that supplies the required coating liquid. From this supply nozzle 16, for example, a viscosity of 1000 cP
The above coating liquid is supplied to one end of the liquid reservoir 14.

Further, a drain receiver 42 is disposed below the backup roll 18 in parallel with the backup roll 18, and a gutter 44 is provided below the drain receiver 42 on the lower side of the coating roll 10. ing. A drain outlet 46 is provided at one end of the bottom of the drain receiver 42, and a liquid tank 48 is arranged immediately below the drain outlet 46. The excess coating liquid returned to the liquid tank 48 from the drain pouring port 46 of the drain receiver 42 is supplied to the pipe 40 by the pump P described above.
It is sent to the supply nozzle 16 through the same and is used for circulation.

As described above, in this roll coater, the coating roll 10, the doctor roll 12, and the backup roll 18 are arranged so as to be inclined, so that the substrate p is carried into the coating position between the coating roll 10 and the backup roll 18 at a constant speed. The conveying path for carrying out the sheet is also formed to be inclined with respect to the horizontal plane. That is, the rotary shafts 50 are arranged in parallel with the backup rolls 18, and thus inclined by about 30 ° with respect to the horizontal plane, and a plurality of conveyances are provided on the respective rotary shafts 50 so that the upper end is flush with the upper surface of the backup roll 18. A roll 52 is arranged to form a transport path. Since the substrate p is conveyed with its width direction inclined, in order to prevent the substrate p from sliding down in the direction orthogonal to the conveying direction, the rotation axis of the conveying roll 52 is arranged along the lower position side of the conveying path. Rotation shafts 54 are arranged in rows at an angle substantially orthogonal to 50, and guide rolls 56 are arranged on each rotation shaft 54.

The roll coater configured as described above operates as follows.

First, while rotating the coating roll 10 whose peripheral surface is grooved into a shape corresponding to the viscosity of the coating liquid at a required number of revolutions in advance, the pump P is operated to bring the contact portion between the coating roll 10 and the doctor roll 12 into contact with each other. Liquid reservoir formed on the upper side of the
A required coating liquid is supplied to one end of 14 from a supply nozzle 16. At this time, since the liquid reservoir 14 is formed to be inclined, the coating liquid supplied to one end of the liquid reservoir 14 has its own weight and the groove 58 formed on the peripheral surface of the coating roll 10. By the rotation operation of, the water flows down toward the other end. In this way, since the coating liquid sequentially flows from the high position side of the liquid reservoir 14 to the low position side, the coating liquid in the liquid reservoir 14 is constantly exchanged, and the entire lengthwise direction of the liquid reservoir 14 is covered. The viscosity of the coating solution becomes uniform. Then, when the coating liquid is uniformly filled in the surface of the coating roll 10, especially in each groove 58 thereof, the substrate p is placed on the transport roll 52 and transported, and the substrate p is backed up with the backup roll 18 and the coating roll. Ten
The coating liquid filled in the groove 58 of the coating roll 10 is inserted onto the surface of the substrate p. by this,
It is possible to form a substantially uniform coating film that causes no practical problems. At this time, the excess coating liquid is returned from the peripheral surface of the coating roll 10 to the liquid tank 48 through the gutter 44, the drain receiver 42, and the drain pouring port 46, and then passes through the pipe 40 by the pump P again. Is sent to the supply nozzle 16 and is circulated for use.

Next, in the roll coater shown in FIG. 4, instead of the doctor roll 12 of the roll coater shown in FIGS. 1 to 3, the doctor bar 92 is brought into contact with the coating roll 10 and the contact portion thereof is provided. This is an example in which an inclined liquid reservoir 94 is formed on the upper side of the. In FIG. 4, the same reference numerals as those in FIG. 3 denote the same members having the same function. In the case where the doctor bar 92 is provided as in this embodiment, instead of attaching the coating liquid supply nozzle above the high position side of the liquid reservoir 94, a required position on the high position side of the doctor bar 92 is provided. A coating liquid supply port may be provided in the above.

Further, the roll coater shown in FIG. 5 has a pair of coating rolls 100 and 110 vertically sandwiching the transport path of the substrate p.
In this example, the doctor bar 102 and the doctor bar 112 are provided so that the coating liquid can be simultaneously applied to both front and back surfaces of the substrate p. Also in this case, although not shown, making one end side of each of the coating rolls 100, 110 and the doctor bars 102, 112 higher than the other end side is similar to the case of the above-mentioned embodiment, The doctor bar 102,1
It is supplied from each of the 12 high positions.

The inclination angle of the coating roll, doctor roll (doctor bar), and backup roll is 10 ° to 80 °.
Although it is preferable that the angle is 0, it may be appropriately set depending on the viscosity of the coating liquid, the engraved state of grooves on the peripheral surface of the coating roll, and the like.

Further, the groove on the peripheral surface of the coating roll is not always necessary, but if the groove is formed in such a direction that the coating liquid in the groove can easily flow down, the coating liquid in the groove can be easily replaced. preferable.

Furthermore, if the roll coater according to the present invention is installed in a temperature-controlled room where the temperature is adjusted to a predetermined temperature, or if a thermostatic unit is installed in the pipe that connects the feed pump of the coating liquid and the supply nozzle, It is preferable because the viscosity of the coating liquid supplied to the unit can be maintained constant and the coating liquid can be applied to the surface of the substrate with a more uniform thickness. Further, the coating roll and / or the doctor may be heated. In that case, the coating liquid flown from one end of the coating roll and / or the doctor is heated by the coating roll and / or the doctor, and is maintained at a predetermined temperature, so it is more preferable to maintain the temperature of the coating liquid. .

[Effect of device]

Since the present invention is constructed and operates as described above, when a roll coater according to the present invention is used to apply the coating liquid to the substrate surface, a high viscosity coating liquid such as photoresist or polyimide resin is used. Even if you do
Even after the substrate has been continuously passed through the roll coater for a long time, there is no difference in the viscosity of the coating liquid between the central part of the liquid reservoir and both ends of the liquid reservoir, and the longitudinal direction of the liquid reservoir Since the viscosity of the coating liquid is uniform over the entire surface, even if the width of the substrate changes, the coating liquid with a uniform viscosity is applied to the entire substrate surface, forming a coating film with a uniform film thickness on the substrate surface. It is possible to solve the problem of conventional coating unevenness.

Further, in the roll coater according to the present invention, since the coating liquid supply means is arranged near the end of the liquid reservoir, the moving mechanism of the coating liquid supply means is unnecessary and the structure is simple.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention.
The figure shows a partial cross-sectional view of the roll coater as seen from the back side, FIG. 2 is a perspective view showing the essential parts thereof, FIG. 3 is a perspective view showing a part of one side of the roll coater in a partially broken state, and FIG. FIG. 5 is a perspective view of a partially broken main part showing another embodiment of the invention, FIG. 5 is a side sectional view of a schematic main part showing still another embodiment of the invention, and FIG. 6 shows an example of a conventional roll coater. Fig. 7 is a schematic perspective view, Fig. 7 is a partially enlarged sectional view of a coating roll, and Fig. 8 is a schematic perspective view showing another example of a conventional roll coater. 10, 100, 110 ... Coating roll, 12 ... Doctor roll, 92, 102, 112 ... Doctor bar, 14, 94 ... Liquid reservoir, 16
... Supply nozzle, 52 ... Conveying roll, 56 ... Guide roll, 58 ...
Groove, p ... Substrate.

Claims (1)

[Scope of utility model registration request] 1. At least one coating roll disposed parallel to a substrate transport path and rotatably, and at least one doctor disposed parallel to the coating roll and contactable to and separable from the coating roll. And at least one coating liquid supply unit that is attached to a liquid reservoir formed on the upper side of the contact portion between the doctor and the coating roll and that supplies the coating liquid to the liquid reservoir. In a roll coater that applies the coating liquid supplied to the liquid reservoir to a substrate that is being conveyed through the coating roll, the coating roll and the doctor are each inclined with respect to their horizontal direction with respect to a horizontal plane, and A roll coater characterized in that the coating liquid supply means is arranged at a position above the upper end of the conveyed substrate.