JPS61284577A - Thin film forming device - Google Patents

Abstract

PURPOSE:To form a thin film on the surface of a substrate, having uniform and high quality, by subjecting the cleaned, dried and cooled substrate to painting by a painting roller immersed partly in a thin film forming liquid in a receiving tray and removing the accumulated excess liquid. CONSTITUTION:While the substrate 10 is transferred, the substrate is cleaned, dehydrated and dried. The dried substrate is cooled and transferred by transferring and guiding means in contact only with both sides of the substrate 10 to adjust the substrate to an adequate temp. The substrate is then fed by guide rollers 23 to a paint depositing roller 29 in a paint depositing part 25. The roller 29 is partly immersed in the thin film forming liquid in the receiving tray 26 and is rotated so that the liquid 28 sticks always on the surface thereof. The substrate 10 moves between the roller 29 and a press roller 30 and the liquid 28 is successively coated on the bottom surface thereof. The excess liquid 28 is pushed backward and accumulates on the bottom surface at the rear end of the substrate. The substrate 10 is then fed into a deposited liquid cutting part 32 where the excess liquid 28 is removed by a cutter 35. The substrate is thereafter dried by heating.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method of depositing a liquid containing a thin film-forming component in an organic solvent onto the surface of a substrate to form a uniform thin film on the surface of the substrate. The present invention relates to a thin film forming apparatus that can be used, in particular, to form thin films as exemplified below.

For example, in a fluorescent display tube that is observed through the front panel,
For forming transparent conductive films provided on the inner surface of the front plate to shield external electric fields, and transparent conductive films provided on the anode substrate as anode conductors and wiring conductors in so-called front-emission type fluorescent display tubes where observation is made through the substrate. Useful and useful.

Furthermore, there are transparent conductive films used in the electrodes of liquid crystal display devices, transparent oxide films formed on the surface of glass plates as a barrier to prevent the elution of alkaline components, and thin films formed on the surfaces of glass plates to strengthen them. Furthermore, it can also be used to form thin films that are applied to the surface of glass plates to provide various features such as anti-reflection and improved heat reflection.

[Prior Art] A three-roll roll coater shown in FIG. 8 is known as an apparatus for depositing a thin film on the surface of a substrate such as glass.

The roll coater 1 includes a backup roller 3 that supports a substrate 2 from below, and a thin film forming liquid 4 that is pressed onto the upper surface of the substrate 2.
The thin film forming liquid 4 is poured onto a doctor roller 6, uniformly spread by the doctor roller 6, and supplied to the coating roller 5. It is composed of

Additionally, a depping method is known as another method for forming a thin film on the surface of a substrate. In the depping method, a paddle large enough to accommodate the entire substrate is provided, the paddle is filled with a thin film forming liquid, and the substrate is immersed, then pulled up and dried to form a thin film on both sides of the substrate. .

[Problems to be solved by the invention] The roll coater has 1. It can be used to coat a substrate with a stable thin film forming solution that does not easily deteriorate, but cannot be used when the thin film forming solution is unstable.For example, indium, tin, titanium, etc. Consider the case of a thin film-forming liquid in which a contained organometallic compound (alkoxy compound) is dissolved in an organic solvent that has a low boiling point and is easily volatile.

Before the liquid is transferred as a thin film onto the substrate 2, pressure is applied twice between the doctor roller 6 and the coating roller 5 and between the coating roller 5 and the substrate 2. Furthermore, since the solvent component of the liquid continues to volatilize from the stage when it is supplied to the doctor roller 6, the liquid is not evenly transferred to the coating roller 5. Therefore, the solvent component of the liquid adhered to the coating roller 5 is The part that has not volatilized is transferred to the substrate 2, but the part where the solvent component has evaporated remains attached to the coating roller 5 and is not transferred to the substrate 2. Therefore, the thin film formed on the substrate 2 is This results in unevenness.

Further, according to the roll coater, it is necessary to sandwich the substrate 2 between the backup roller 3 and the coating roller 5, so when using substrates with different thicknesses, it is necessary to adjust the distance between the rollers.

Therefore, when using an unstable thin film forming liquid as mentioned above, the above-mentioned dipping method is applied, but this method requires a sufficient amount of liquid to immerse the entire substrate. However, there is a problem in that it is not economical because the amount of liquid that deteriorates over time also increases.

In addition, when the substrate is pulled out of the liquid after immersion, volatilization begins from the top of the substrate that was pulled up first, and the liquid that flows down the surface of the substrate after being pulled up tends to accumulate in the lower part of the substrate. However, there was a problem in that the thickness of the thin film formed was not constant.

Furthermore, since the entire substrate is immersed, there is a problem in that it is not possible to form a thin film on only one side of the substrate as in the case of the roll coater method.

[Object of the Invention] The present invention has been made to solve the above-mentioned problems, and can be applied to unstable thin film forming liquids, and can form a uniform and high quality thin film on only one side of a substrate. It is an object of the present invention to provide an economical thin film forming apparatus that can be used to form a thin film, and uses less amount of a thin film forming liquid.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a substrate cleaning unit including a substrate transfer means and a substrate cleaning device, and a dehydration unit for removing cleaning liquid from the cleaned substrates. A dehydration/drying section provided with a drying means, a cooling transfer section having a transfer guide means that contacts only both sides of the substrate, a saucer for storing a thin film forming liquid, and a portion of the substrate being immersed in the thin film forming liquid in the saucer. a coating section having a coating roller disposed as shown in FIG.
A transfer heating unit for drying the thin film of the transferred substrate is arranged and configured in a continuous manner.

[Operation] The substrate is first sent to the substrate cleaning section, and while being transferred by the transfer means, the surface is cleaned by the substrate cleaner.

Next, the cleaned substrate is sent to a dehydrating and drying section, and the cleaning liquid adhering to the surface is removed by the heating action of the dehydrating and drying means.

Next, the substrate is continuously fed into a cooling transfer section.

The substrate, which has been heated in the previous step and whose temperature has increased, is cooled while being transferred by the transfer guide means, and the temperature is adjusted to a temperature suitable for applying the thin film forming liquid. In addition, the transport guide means is
Since the substrate is guided and transferred by contacting only both sides of the cleaned and dried substrate, the surface of the substrate is not contaminated.

Next, the substrate, which has been adjusted to an appropriate temperature, is sent to the coating section. Since the coating roller of the coating section rotates with a portion immersed in the thin film forming liquid contained in the saucer, the thin film forming liquid always adheres to the surface of the coating roller.

When the substrate is fed onto the coating roller, the lower surface of the tip of the substrate comes into contact with the top of the outer peripheral surface of the coating roller. and,
As the roller rotates, the thin film forming liquid accumulates in the gap between the substrate and the coating roller in front of the contact portion due to surface tension.

The substrate is slid over a pool of the thin film forming liquid and transferred over the coating roller, so that the thin film forming liquid is uniformly applied to the lower surface of the substrate.

Next, the substrate is sent to the accumulated liquid cutting section. The substrate is fed by a discharge side transfer guide means that contacts only both sides of the substrate, and excess thin film forming liquid accumulated on the lower surface of the rear end of the substrate is removed by the operation of a car roller.

Next, the substrate is fed into a transfer heating section. In this step, the thin film forming liquid is heated and dried to form a uniform thin film on the lower surface of the substrate. The substrate on which the thin film has been formed is then transferred to the outside of the apparatus.

[Example] Examples of the present invention will be described below.

FIG. 1 is a front view showing the overall configuration of the thin film forming apparatus, and 7 in the figure is a substrate cleaning section. As shown in Figure 2,
The substrate cleaning unit 7 includes a substrate cleaning device 9 inside the case 8, and
A plurality of pairs of feed rollers 11 are provided as means for transporting the substrate 10, and the inside of the case 8 is shielded from the outside world so that the internal temperature, humidity, etc. are kept constant. The feed rollers 11 are composed of a pair of upper and lower rubber rollers, and a plurality of pairs (8 pairs in the illustrated embodiment) of the feed rollers 11 are arranged in parallel so that the substrate IO is held and conveyed in the direction of arrow A. ing.

Moreover, the substrate cleaning device 9 is 11! An upper roll brush 12a rotates in contact with both the upper and lower surfaces of the substrate 1O to be sent.
and a lower roll brush 12b. A spray nozzle 13 is provided at the upper position of each upper roll brush 12a and at the lower position of each lower goal brush 12b, respectively.
It is configured so that pure water W as a cleaning liquid can be sprayed and supplied toward the roll brush 12.

Note that the installation positional relationship between the roll brush 12 and the feed roller 11 is not limited to the example shown in the drawing, and various other configuration examples are possible. Further, the spray/zzle 13 may be installed at a position where it can directly spray the pure water W onto the surface of the substrate 10.

Next, next to the substrate cleaning section 7, a dehydrating/drying section 14 is continuously installed. As shown in FIG. 3, a pair of upper and lower double rollers 15 are provided near the entrance of the dehydrating and drying section 14 as a first dehydrating and drying means. The double roller 15 is made of a porous resin with good water absorption properties, and is configured to come into contact with both the upper and lower surfaces of the cleaned substrate 10 to absorb moisture adhering to the surface.

Next to the double roller 15, hot air nozzles 16 are provided at both the upper and lower positions as a second dehydration drying means, and hot air is blown onto both the upper and lower surfaces of the substrate 10 sent out from the double roller 15. .

A transfer roller 17 is provided next to the warm air nozzle 16, which is configured to be able to dry the substrate 10. As shown in FIG. 4, the transfer roller 17 is constructed by having a plurality of rotating shafts 18 that are rotationally driven by a drive source (not shown), each provided with a pair of wheels 19. Each wheel 19 has a shape in which a large-diameter dish-shaped disk 19b is provided on the outside of one disk 19a, and the substrate 10 is conveyed with one side thereof placed on the outer peripheral surface of the disk 19a. It is configured as follows. Furthermore, since one of the pair of wheels 19.19 can be freely slid in the axial direction and fixed at any position, the mounting width of the pair of vehicles 19 with respect to the rotating shaft 18 is limited. It can be set according to the width of the substrate 10.

The double roller 15, hot air nozzle 16, and transfer roller 17 described above are covered by a case 20. The case 20 is in direct communication with the case 8 of the substrate cleaning section 7, so that the cleaned substrate 10 can be carried into the dehydration-drying process without being exposed to the outside air. Further, the temperature, humidity, etc. inside the case 20 are configured to be maintained at values suitable for dehydration and drying work.

Next, next to the dehydrating/drying section 14, a cooling transfer section 21 is continuously arranged. As shown in FIG.
A guide roller 23 is provided therein as a transfer guide means. The structure of the guide roller 23 is approximately the same as that of the transfer roller 17 provided in the dehydration/drying section 14.
It is configured such that the cleaned and dried substrate 10 transported from the previous process can be transported while being supported only by both sides of the substrate 10. In addition, the guide roller 23 is provided with a drive means 2.
4, and the guide roller 23 is movable up and down while remaining horizontal, so that the feeding position to the next process can be arbitrarily adjusted.

The case 22 is directly connected to the case 20 of the dehydration/drying section 14, so that the substrate 10 that has been dehydrated and dried can be carried into the cooling process without being exposed to outside air. An air conditioner (not shown) is connected to the case 22 via an exhaust pipe 22a, and the air inside the case 22 is forcibly sucked out. Furthermore, as will be described later, cooling air is supplied from the air conditioning equipment to the coating section 25 for the next step. Therefore, since the cooling air is constantly circulating from the coating section 25 to the inside of the case 22, the temperature of the substrate 1, which has been subjected to dehydration and drying processes, has increased.
is cooled down to a required temperature while being conveyed by the guide rollers 23.

Next, next to the cooling transfer section 21, a coating section 25 is continuously arranged. As shown in FIG.
A saucer 26 is provided in the center. The saucer 26 has the shape of a cylinder divided in half in the axial direction, and is positioned in a direction perpendicular to the feeding direction of the substrate 10 and the axis (longitudinal direction) and below the conveying surface of the guide roller 23. It is provided. A drive mechanism 27 is attached to the saucer 26 so that it can be moved downward from the above-mentioned position during cleaning or the like.

Further, inside the saucer 26, a thin film forming liquid 28 (hereinafter abbreviated as liquid 28) is stored.

Although not shown in the figure, an automatic supply device for liquid 28 is connected to the lower part of the saucer 26 via a supply pipe, and is configured so that the amount of liquid in the saucer 26 is maintained at the minimum necessary constant level. has been done. Further, on both sides of the opening of the saucer 26, flange-shaped covers 26a are provided facing inward in order to suppress volatilization of the liquid.

A coating roller 29 is provided above the saucer 26 . The coating roller 29 has a radius smaller than that of the saucer 26 by one turn, and its length in the axial direction is set to be slightly smaller than the longitudinal dimension of the saucer 26 . The applicator roller 29 is disposed at a position such that a portion of the applicator roller 29 fits inside the saucer 26 and is partially immersed in the liquid 28. The position of the top of the surface is
It is configured to be slightly above the upper surface of the substrate 10 being transported. Further, the coating roller 29 is connected to a drive source (not shown) and is configured to be freely operated according to one work order. Furthermore, although the coating roller 29 is made of metal with a long life in this embodiment, it may also be made of ceramics or the like, or of resin or the like as long as it is not immersed in the liquid 28.

A presser roller 30 is provided above the coating roller 29 . The presser roller 30 can be moved downward by a drive means (not shown), and presses the upper surface of the substrate IO being transferred on the coating roller 29 by its own weight.
It is configured to prevent the substrate 10 from floating up.

Then, the saucer 26. The coating roller 29, presser roller 30, etc. are shielded from the outside world by a case 31, and apply the liquid 28 under optimal environmental conditions to the clean substrate 10 that has been sent in from the previous process and has been adjusted to an appropriate temperature. It is now possible to

That is, an air conditioner (not shown) is connected to the case 31 via a feed pipe 31a, so that clean, dry, and cold air is always supplied into the case 31. Note that this dry, cold air flows into the case 22 of the cooling transfer section 21, as described above.

Next, next to the coating section 25, a stagnant liquid cutting section 32 is disposed continuously. As shown in FIG. 6, inside a case 33 connected to the case 31 of the coating section 25, a discharge guide roller 34 is provided as a discharge side transfer guide means. The discharge guide roller 34 has substantially the same structure as the guide roller 23, and supports only both sides of the substrate 10, the lower surface of which is coated with a thin film of the liquid 28, and conveys it.

The front part of the discharge guide roller 34 protrudes from the case 33 and is inserted into the coating roller 29 within the case 22 of the coating section 25.
The cutter 35 is located below this part.
is provided. The cutter 35 includes a rectangular cutter plate 36 with an edge formed on its upper edge, and a drive device 37 for moving the cutter plate 36 up and down.

Then, the cutter 35 is connected to the guide roller 23. The liquid 28 is moved upward in synchronization with the operation of the coating roller 29, the discharge guide roller 34, etc., and comes into contact with the lower surface of the substrate 10 coated with the liquid 28, so that the excess accumulated on the lower surface of the rear end of the substrate 10 is removed. The liquid 28 is configured to be removed.

Next, as shown in FIG. 7, a transfer heating section 38 is continuously arranged next to the pool cut section 32. The transfer heating section 38 includes a conveyance roller 40 and a feeding device 41 inside a case 39 . The conveyance roller 40 is
Similar to the guide roller 23, it is configured to contact only both sides of the substrate 10 and support the substrate 10 in a movable manner. Further, the feeding device 41 includes a feeding plate 41 that is guided by a fixed guide rod 41a and driven back and forth.
It has b.

The inside of the case 39 is shielded from the outside world, and a heating means such as a heater (not shown) is provided inside the case 39 to heat and dry the applied liquid 28 to coat the substrate 10. A thin film is formed on the bottom surface.

Next, the operation of the configuration described above will be explained.

The substrate 10 is first sent to the substrate cleaning section 7. While being conveyed by the feed roller 11, one substrate 10 is cleaned on both upper and lower surfaces by upper and lower roll brushes 12a, 12b and pure water W sprayed from a spray nozzle 13.

Next, the cleaned substrate 10 is sent to the dehydration drying section 14. The substrate 1O is sandwiched from above and below by double rollers 15, and moisture adhering to the surface of the substrate 10 is absorbed. Continuously, hot air is blown from the hot air nozzle 16 onto both sides of the substrate 10 to evaporate the moisture left on the surface of the substrate 10. The dried substrate 1O is transferred to the transfer roller 1
7 and sent to the primary process.

Next, the substrate 10 is transported by guide rollers 23 in the cooling transport section 21 .

Cooling transfer section? The air inside the case 22 of
The clean cooling air supplied to the adjoining coating section 25 by the air conditioning facility always flows into the case 22 of the cooling transfer section 21. The substrate 10, which has been heated in the previous process and whose temperature has increased, is exposed to this cooling air and cooled down to a temperature that does not adversely affect the liquid 28. In the first process, the guide roller 23 is used to clean and dry the substrate 10. Since the substrate 10 is transferred by the guide hand while contacting only both sides of the lO, the surface of the substrate 10 is not contaminated.Next, the substrate 10, which has been adjusted to an appropriate temperature, is transferred to the coating section 25. sent. Since the coating roller 29 rotates with a part immersed in the liquid 28 contained in the saucer 26, the surface of the coating roller 29 is always covered with liquid 28.
8 is attached.

The substrate 10 is fed to a position slightly lower than the top of the outer peripheral surface of the coating roller 29. After the substrate 10 comes into contact with the outer circumferential surface of the coating roller 29 , the substrate 10 climbs up onto the coating roller 29 while being slightly inclined due to the driving force of the guide roller 23 . When the guide roller 23 reaches the top, the operation of the guide roller 23 is temporarily stopped. Since the coating roller 29 continues to rotate,
The liquid 28 accumulates in the gap before the contact between the substrate 10 and the coating roller 29 due to surface tension.

Then, the presser roller 30 descends and presses the top surface of the substrate 10, and the guide roller 23 is driven again to feed the substrate IO onto the coating roller 29. At this time, the substrate 10 is moved between the substrate IO and the coating roller 29. The lower surface of the liquid 28 is brought into contact with the pool of liquid 28 that has formed in the gap, and the liquid is sent while sliding, and the excess liquid is pushed backward by the coating rollers 2 and 9 as it is transferred.
The liquid 28 is uniformly and reliably applied to the lower surface of the substrate 10. In this step, the liquid 28 is not transferred by applying pressure to the substrate 10, but is formed by the application roller 29. A thin film is formed by running the substrate 10 over the pool of liquid z8.

Therefore, it is sufficient that there is enough liquid in the saucer 26 to soak at least a portion of the application roller 29, and the automatic supply device All you have to do is adjust it.

Further, the saucer 26 is provided with a cover 26a, and the liquid 26 is provided with a cover 26a.
Since the volatilization of 8 is suppressed, the quality of liquid 2 is always constant.
8 can be applied, and the yield of the liquid 28 is further improved, making it possible to realize a low-cost thin film forming operation.

Next, the substrate 10 is sent to the accumulated liquid cutting section 32. The substrate 10 is sent by a discharge guide roller 34, and the excess liquid 28 accumulated on the lower surface of the rear end of the substrate is removed by a cutter 35 that is driven in synchronization with the operation of the discharge guide roller 34, etc. .

Next, the substrate 10 is transferred to the transport roller 4 of the transport heating section 38.
0 is sent on top. The liquid 28 adhering to the lower surface of the substrate 10 is heated and dried to form a uniform thin film.
Then, the substrate lO on which the thin film is formed is transported to a feeding device 4
1 is sent out to the outside of this device.

Next, the embodiments described above are configured so that all operations from cleaning to heating are consistently performed inside the case, which is isolated from the outside world. Therefore,
Dust in the air, which is the biggest obstacle to thin film forming operations, does not become a problem, and high-quality and uniform products can be manufactured.

[Effects of the Invention] As explained above, the thin film forming apparatus of the present invention arranges each process section from the substrate cleaning section to the transfer heating section in succession,
The coating section includes a saucer containing a thin film forming liquid and a coating roller disposed so as to be partially immersed in the thin film forming liquid in the saucer.

Therefore, according to the present invention, a pool of the thin film forming liquid is formed in the gap near the contact portion between the substrate and the coating roller, and the substrate is conveyed while contacting the pool, thereby coating the liquid. This will have the following effects:

(1) The thin film forming solution does not require a large amount at once and can be replenished into the saucer little by little, so there is less deterioration.
Therefore, it can also be used in unstable thin film forming solutions in which an organic metal is dissolved in a low boiling point organic solvent.

(2) Since there is little deterioration of the thin film forming liquid, the thin film forming liquid can always be applied in good condition, and a thin film with uniform quality can be formed.

(3) Since the thin film forming liquid has little deterioration and the amount used can be kept to a minimum, manufacturing costs can be reduced.

(4) Since the liquid is applied from the bottom of the substrate, the thickness of the substrate can be freely selected and no adjustment is required.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the overall configuration of the present invention, and FIG. 2 is a schematic diagram showing the overall configuration of the present invention.
3 is a sectional view showing the main parts of the substrate cleaning section, FIG. 3 is a sectional view showing the main parts of the dehydration drying section, FIG. 4 is a front view of the transfer roller,
FIG. 5 is a sectional view showing the main parts of the cooling transfer section, and FIG.
7 is a sectional view showing the main parts of the coating section and the accumulated liquid cutting section; FIG. 7 is a sectional view showing the main parts of the transfer heating section; FIG. 8 is a side view showing an example of the configuration and usage of the roll coater. It is. 7...Substrate cleaning section, 9...Substrate cleaning device, lO...
Substrate, 11... Feed roller as a transfer means, 14.
... Dehydration drying section, 15 ... Double roller as dehydration drying means, 16 ... Hot air nozzle as dehydration drying means, 21 ... Cooling transfer section, 23 ... Guide roller as transfer guide means , 25... Application section, 26... Receiver, 28... Thin film forming liquid (liquid), 29... Application roller, 32... Reservoir moat cut section, 34... Discharge side transfer A discharge guide roller as a guide means, 35...cutter. 38...Transfer heating section, W...Pure water as a cleaning liquid. Patent applicant Futaba Electronics Co., Ltd. ¥ & 5 Figure 7 Figure 8

Claims (3)

[Claims] (1) A substrate cleaning section equipped with a substrate transfer means and a substrate cleaning device, a dehydration drying section equipped with a dehydration drying means for removing the cleaning liquid from the cleaned substrate, and contact only on both sides of the substrate. a cooling transfer portion having a transfer guide means; a coating portion having a saucer for storing a thin film forming liquid; a coating roller disposed so as to be partially immersed in the thin film forming liquid in the saucer; and a discharge side transfer guide. A thin film forming device characterized in that a stagnant liquid cutting section having a vertically movable cutter disposed below the means and a transfer heating section for drying the thin film of the transferred substrate are arranged in succession. Device. (2) Claim 1, wherein the transfer guide means is configured to temporarily stop when the substrate comes into contact with the coating roller.
Thin film forming apparatus as described in . (3) The thin film forming apparatus according to claim 1 or 2, wherein the coating roller of the coating section is a metal roller.