KR101016844B1 - Roll printing method and color filter manufactured thereby - Google Patents

Abstract

The present invention provides a printing method using a substrate, a printing plate (cliché), a transfer device, and a roll printing apparatus including a plurality of printing rolls and a coater, and a color filter manufactured using the same. According to the printing method of the present invention, instead of cleaning the printing plates passing through each printing roll every time, the printing plates passing through all the printing rolls need to be cleaned only once, thus reducing the production time and reducing the production cost when manufacturing the color filter. Can be.

Color filter, offset printing

Description

ROLL PRINTING METHOD AND COLOR FILTER MANUFACTURED THEREBY}

The present invention relates to a printing method using a substrate, a printing plate (cliché), a transfer device, and a roll printing apparatus including a plurality of printing rolls and coaters, and a color filter manufactured using the same.

In general, a liquid crystal display (LCD) displays an image by controlling light transmittance of a liquid crystal using an electric field. To this end, the LCD includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix, and a driving circuit for driving the liquid crystal panel. The liquid crystal panel includes pixel electrodes for applying an electric field to each of the liquid crystal cells and a reference electrode, that is, a common electrode. The pixel electrode is formed for each liquid crystal cell on the lower substrate, while the common electrode is integrally formed on the front surface of the upper substrate. Each of the pixel electrodes is connected to a thin film transistor (hereinafter, referred to as TFT) used as a switching element. The pixel electrode drives the liquid crystal cell together with the common electrode according to the data signal supplied through the TFT. Such LCDs can be miniaturized compared to CRTs, and are widely used in personal computers and notebook computers, as well as office automation devices such as photocopiers, mobile phones and pagers.

In the liquid crystal display device, in order to display a color image, light generated from a light source is separated into three primary colors of light, that is, red, green, and blue light. To this end, a red (hereinafter referred to as 'R') filter that transmits only red light, a green (hereinafter referred to as 'G') filter that transmits only green light, and a blue (hereinafter referred to as 'B') filter that transmits only blue light are used for each pixel. I need it. R, G, and B filters should be formed so as not to overlap each other to prevent image deterioration and color bleeding.

In general, micropatterns used in semiconductor circuit devices and display devices such as LCDs and PDPs are formed by photolithography using photoresist, and are generally subjected to coating, exposure, development, cleaning, and curing. Are manufactured. However, although photolithography has the advantage of obtaining precisely the desired pattern, it has to go through many steps and many kinds of materials are used to maximize the effect of photoresist, coating, etc. There is a disadvantage that a large amount of photoresist is consumed in the process of. Recently, in order to overcome such drawbacks of photolithography, a technique for obtaining a fine pattern by a roll printing method has been proposed and researched.

Roll printing equipment for pattern formation can be applied in various ways such as offset printing, reverse offset printing, roll-to-roll printing, and R (red) and G (green) components of color filters. And B (blue) color and BM pattern, as well as TFT, PDP electrode formation pattern and barrier material pattern transfer can be widely applied.

Roll printing equipment typically consists of coaters, printing rolls, roll drives, printing plates (clichés) or drives for substrate stages and stage alignment, in addition to printing plates and / or pipe cleaners and blankets. A drying apparatus, various sensor apparatuses, etc. for absorbing the absorbed solvent and drying a blanket can be further provided.

Among the pattern forming methods using the roll printing equipment, in particular, inverted offset printing, because despite the advantage that the pattern precision is equal to or more than photolithography, because the cleaning of the printing plate must be repeated every time after transferring each color to the substrate, There was a problem that the process time is prolonged and the production cost is increased. That is, in the conventional manufacturing of color filters using inverted offset printing, the R, G, and B printing plates for printing red, green, and blue colors need to be cleaned each time. A printing plate or three washes were required.

The present invention is to solve the problems of the prior art as described above, the object of the present invention is that instead of cleaning each time the printing plate passed through each printing roll roll cleaning so that you only need to clean the printing plate passed through all the printing roll once To provide a way.

Still another object of the present invention is to provide a color filter manufactured using the printing method.

One aspect of the present invention for achieving the above object is a substrate; A printing plate disposed in parallel with the substrate and having a pattern portion; A transfer device on which the substrate and the printing plate are mounted and which moves the substrate and the printing plate; N printing rolls rotatably installed; And a printing method using a roll printing apparatus comprising n coaters for coating a coating on the n printing rolls.

N is a natural number of 2 or more,

The printing method includes the steps of: (a) transferring the coating of the first printing roll to the pattern portion of the printing plate as the printing plate contacts and passes through the first printing roll; (b) transferring the coating pattern remaining on the first printing roll to the substrate as the substrate contacts and passes the first printing roll to form a first pattern; (c) moving the position of the printing plate in a direction perpendicular to the moving direction of the substrate and the printing plate by the width of the first pattern after the forming of the first pattern; And (d) repeating steps (a) to (c) while sequentially forming the second to nth patterns with respect to the second to nth printing rolls using the printing plate as it is.

After the n-th pattern is formed, the printing is terminated after the step (B).

A second aspect of the present invention for achieving the above object provides a color filter manufactured using the printing method.

According to the manufacturing method of the present invention, instead of cleaning the printing plates passing through each printing roll every time, the printing plates passing through all the printing rolls may be cleaned only once, so that the process time during roll printing can be shortened and the production cost can be reduced.

In addition, the coating coating on the printing roll, the coating of the printing roll may be transferred to the printing plate, and the process of printing the coating pattern remaining on the printing roll on the substrate may be performed in one step.

In addition, the Red, Green, and Blue patterns can be continuously printed on one substrate.

Further, the red pattern transfer, the green pattern transfer, and the blue pattern transfer and the cleaning of the printing plate can be continuously performed.

Hereinafter, the present invention will be described in more detail.

One aspect of the invention, the substrate; A printing plate disposed in parallel with the substrate and having a pattern portion; A transfer device on which the substrate and the printing plate are mounted and which moves the substrate and the printing plate; N printing rolls rotatably installed; And a printing method using a roll printing apparatus comprising n coaters for coating a coating on the n printing rolls.

N is a natural number of 2 or more,

The printing method includes the steps of: (a) transferring the coating of the first printing roll to the pattern portion of the printing plate as the printing plate contacts and passes through the first printing roll; (b) transferring the coating pattern remaining on the first printing roll to the substrate as the substrate contacts and passes the first printing roll to form a first pattern; (c) moving the position of the printing plate after the first pattern forming step in a direction perpendicular to the moving direction of the substrate and the printing plate by the width of the first pattern; And (d) repeating steps (a) to (c) while sequentially forming the second to nth patterns with respect to the second to nth printing rolls using the printing plate as it is.

After the n-th pattern is formed, the printing method is finished after the step (b).

The printing method according to the present invention may further comprise the step of cleaning the printing plate after forming the n-th pattern.

If the method is specifically described for the case of n = 3,

Board; A printing plate disposed side by side with the substrate and having a pattern portion; A transfer device on which the substrate and the printing plate are mounted and which moves the substrate and the printing plate; First to third printing rolls rotatably installed in the same direction as the transfer direction of the substrate and the printing plate; And a roll printing apparatus including first to third coaters for coating a coating on the first to third printing rolls.

As the printing plate contacts and passes under the rotating first printing roll, the coating of the first printing roll is transferred to the pattern portion of the printing plate, and the substrate contacts with the rotating first printing roll. A first pattern forming step including forming a first pattern by transferring the coating pattern remaining on the first printing roll to the substrate as it passes;

After the first pattern forming step, the position of the printing plate is moved in a direction perpendicular to the moving direction of the substrate and the printing plate by the width of the first pattern, and the printing plate contacts and passes under the rotating second printing roll. The coating pattern of the second printing roll is transferred to the pattern portion of the printing plate, and the coating pattern remaining on the second printing roll is transferred to the substrate as the substrate contacts and passes under the rotating second printing roll. A second pattern forming step including transferring to form a second pattern; And

After the second pattern forming step, the position of the printing plate is moved in a direction perpendicular to the moving direction of the substrate and the printing plate by the width of the second pattern, and the printing plate contacts and passes under the rotating third printing roll. The coating pattern of the third printing roll is transferred to the pattern portion of the printing plate, and the coating pattern remaining on the third printing roll is transferred to the substrate as the substrate contacts and passes under the rotating third printing roll. And a third pattern forming step including transferring and forming a third pattern.

The substrate and the printing plate are arranged side by side and mounted to the transfer device. The conveying apparatus functions to move the substrate and the printing plate in a predetermined direction, preferably in a straight direction as shown in FIG. 1.

The substrate may be a substrate having a hard surface, such as a glass substrate used as a substrate for electronic materials and display materials, or may be a flexible substrate that can be bent and formed of a polymer polymer such as polyethylene, polypropylene, polyvinyl, and the like.

For example, the material of the substrate may be a polyester used in an e-paper or flexible display; Flexible plastic materials such as PET; Polyurethane materials used for substrates of PCBs; Hard plastic material of epoxy material; Or glass may be used, but is not limited thereto.

The conveying device on which the substrate and the printing plate are mounted (or moving) may include a conveyor belt and a motor for driving the conveyor belt.

The printing roll may be made of stainless steel subjected to electrolytic polishing. As an example, a printing roll can be manufactured using the electrolytic polishing process of standard materials, such as SUS304, SUS305, and SUS316. If necessary, a printing roll may be manufactured using a plated surface of nickel or the like to prevent corrosion.

Here, the shape of both end regions of the printing roll may be cylindrical or like a central region of the printing roll, respectively, but may be a funnel shape, but is not limited thereto.

The printing roll may be rotated by a drive motor such as a servo motor or a linear motor. However, the type of motor is not limited to the above illustrated, and the printing roll may be rotated using various kinds of motors. Among the various motor types, it is preferable to use a linear motor in terms of coating precision and uniformity.

Rotational speed of the printing roll can be calculated by the formula (1).

Rotational speed of the printing roll (rpm) = A / (2πR)

Here, A is the moving speed of the substrate or the printing plate (m / min), when the blanket is wound on the surface of the printing roll R (m) = radius of the printing roll (r) + thickness of the blanket (d), the printing If no blanket is detected on the roll surface, R is the radius of the printing roll.

It is preferable that the moving speeds of a board | substrate and a printing plate are 0.5 m / min-100 m / min, and it is more preferable that they are 3.0 m / mim-60 m / min.

The rotational speed of the printing roll may be calculated by Equation 1 using the moving speed of the substrate and the printing plate and the radius of the printing roll.

For example, when the radius of the printing roll is 0.2 m, the calculated rotation speed of the printing roll is preferably about 0.4 to 79.58 rpm, more preferably 2.39 to 47.75 rpm.

Here, the numerical values of the moving speed of the substrate and the printing plate, the radius of the printing roll, and the rotating speed are just one example, and thus the scope of the present invention is not limited. The numerical values may be variously changed and set according to the design conditions of the roll printing apparatus according to the present invention.

The coater may be installed at an angular position of more than 0 and less than 180 degrees with respect to the center axis of the printing roll to coat a coating on the printing roll when the printing roll is rotated.

The coater may coat the coating on the printing roll while the printing roll is rotated by the rotational speed N of the printing roll calculated by Equation 2.

[Equation 2] N = L / (2πR)

Here, L is the length of the substrate or printing plate, when the blanket is wound on the surface of the printing roll R (m) = the radius of the printing roll (r) + the thickness of the blanket (d), the blanket on the surface of the printing roll If not detected, R is the radius of the printing roll.

Here, when the periphery of the printing roll is larger than the length of the substrate and all the patterns are transferred by one rotation coating, N may have a value of 0.5, the diameter of the printing roll is 0.1 m, and the substrate is 9 generations. In the case of a substrate (2600 mm × 3100 mm), N may have a value of up to 10.

The coating includes red, green, blue color inks and black matrix (BM) ink compositions used to make color filters for LCDs and PDPs; Printing ink resists for forming TFT circuits; Optical ink; Metal solution for wiring; Conductive paste; Resist; It can be any one of an adhesive and an adhesive.

Here, color inks and black matrix inks for forming color filters of LCDs and PDPs include organic and inorganic pigments and dispersants for producing red, green, blue and black colors; Resin binders for forming a coating film; Surfactants and adhesion promoters as additives for smoothing the coating; Initiators or catalysts for thermal or light curing; And a plurality of solvents. However, the present invention is not limited thereto.

On the other hand, the roll printing method according to the present invention can be used to produce a color filter. For example, the roll printing method according to the present invention can be used when continuously transferring an R (Red) color pattern, a G (Green) color pattern, a B (Blue) color pattern, and a black matrix (BM) pattern on a color filter substrate. Can be.

The roll printing method according to the present invention is used to continuously transfer an R (Red) color pattern, a G (Green) color pattern, a B (Blue) color pattern, and optionally a black matrix (BM) pattern on a color filter substrate. In this case, the cleaning plate for cleaning the printing plate may be further included so that the printing plate of the printing roll is transferred to the printing plate conveying apparatus after cleaning the printing plate transferred.

As the cleaning device, a cleaning device using a cleaning liquid may be used, or a cleaning device using the printing roll and adhesive tape may be used. Of course, the printing plate may be cleaned by a combination of the two methods.

In the roll printing method according to the present invention, the coating roll of the printing roll is transferred to the pattern portion of the printing plate as the rotating printing roll and the printing plate is in contact with each other, and then the rotating printing roll and the substrate are in contact with each other. By passing through the coating pattern remaining on the printing roll is transferred to the substrate to form a pattern, this pattern forming step is performed for each color, for example, red, green, Blue continuously.

In the method in which the pattern formation is continuously performed, after the previous pattern formation is completed, the position of the printing plate is moved in the direction perpendicular to the moving direction of the substrate and the printing plate by the width of the formed pattern, and then the following pattern forming step is performed in the same manner. It depends on how to do it. For example, after moving the printing plate which transfers the red non-wire portion by 1/3 of the entire width of Red, Green, and Blue without cleaning, the non-wire portion of the Green is transferred, and then moved by 1/3 of the overall width, It is a way to transfer. At this time, the printing order is not limited to the order of Red, Green, Blue.

In the printing method, after printing or replacing the printing plate and cleaning or replacing the substrate after the last pattern formation, the printing method may be repeatedly performed on another substrate.

In the printing method, before the printing plate is in contact with the first to n-th printing roll, respectively, further comprising the step of coating the coating on the first to n-th printing roll by the first to n-th coater, respectively. can do.

In addition, before the printing plate is in contact with the first printing roll, a blanket is prepared on each of the first to nth printing rolls, and the first to nth colors are coated on the blanket at the same time. And by continuously moving the substrate, it is possible to shorten the process time required in each pattern forming step.

In the printing method, the method may further include measuring the width of the pattern formed in the step (b) before the step (c).

Further, before the printing plate comes into contact with the first printing roll, the width of each of the first patterns to the nth patterns is calculated in advance and the value is used for the movement of the printing plate in the step (c), thereby measuring each width. The step can be omitted and the process time can be shortened.

In the printing method, n is preferably 3, and the color of the coating preferably includes red, green, and blue.

Further, in the printing method, the pattern can be used as a pattern of the color filter.

A second aspect of the present invention relates to a color filter manufactured using the printing method.

Hereinafter, with reference to the drawings, it will be described in more detail with respect to the present invention.

A roll printing apparatus according to the present invention, as shown in Figure 1, the substrate (8); A printing plate (cliché) disposed in parallel with the substrate and having pattern portions 5 and 6; A transfer device (not shown) mounted with the substrate and the printing plate and moving the substrate and the printing plate in the straight direction; First to third printing rolls 2 to 4 installed to be rotatable in the same direction as the transfer direction of the substrate and the printing plate; And first to third coaters (not shown) for coating a coating on the first to third printing rolls.

The substrate 8 and the printing plate can be mounted in the conveying apparatus and moved in either straight direction.

The conveying apparatus may include a stage on which the substrate 8 and the printing plate are mounted, and a linear motor for moving the stage 15 in any linear direction.

The printing roll is located on the conveying device and rotates. The printing roll can be rotated using a linear motor (not shown).

The printing roll is rotated in the same direction as the moving direction of the substrate and the printing plate.

When the moving speed of a board | substrate and a printing plate is A (m / min), the rotational speed of a printing roll becomes A / (2 (pi) R) (rpm) when the radius of a printing roll is R. Here, in the case where the blanket 1 is wound on the surface of the printing roll, R is a value obtained by adding the radius of the printing roll itself (r) and the thickness of the blanket (d), and the blanket is wound on the surface of the printing roll. If not, R is the radius of the print roll itself.

The coater is disposed on one side of the printing roll to coat the ink on the printing roll.

Hereinafter, a pattern printing process using a roll printing apparatus according to the present invention will be described with reference to the drawings.

Fig. 1A shows the pre-printing state, in which the substrate 8 and the printing plate are arranged side by side and attached to the transfer apparatus. In this state, the red printing roll 2 is rotated by the linear motor and the printing plate and the substrate are linearly moved toward the printing roll in order by the transfer device. If the moving speed of a board | substrate and a printing plate is A (m / min) at this time, the rotation speed of a printing roll will be A / (2 (pi) R) (rpm) when the radius of a printing roll is R. Here, when the blanket is wound on the surface of the printing roll, R is a value obtained by adding up the printing roll itself radius r and the thickness d of the blanket.

The coating of the ink by the coater starts at the same time as the rotation of the printing roll and the linear movement of the substrate and the printing plate.

1B shows a red printed state. As the printing plate moves toward the traveling direction, a part of the red ink coated on the surface of the blanket wound on the printing roll is transferred to the protrusion 5 of the pattern portion of the printing plate consisting of the protrusion 5 and the groove 6. That is, part of the red ink coated on the surface of the blanket wound on the printing roll 2 is transferred to the protrusion 5 of the printing plate, and the remaining ink pattern remains on the surface of the blanket wound on the printing roll.

When the substrate is further moved in the advancing direction, the ink pattern attached to the surface of the blanket wound on the printing roll starts to be transferred to the substrate 8 from the moment the front end of the substrate is in contact with the printing roll, and the substrate proceeds by the length of the substrate. Further moving in the direction, all the ink patterns attached to the surface of the blanket wound on the printing roll are transferred to the substrate, thereby completing the first pattern (Red) forming step.

1C shows a green printed state. After the red pattern is formed in (B), the position of the printing plate is moved in the direction perpendicular to the advancing direction by the width of the already formed red pattern, and when the substrate and the printing plate pass through the green printing roll 3, Green) is formed.

(D) of FIG. 1 shows a blue printed state. After the green pattern is formed in (C), the position of the printing plate is moved once more in the direction perpendicular to the traveling direction by the width of the already formed green pattern, and then When the printing plate passes through the blue printing roll 4, a third pattern Blue is formed.

Finally, the printing plate on which the ink pattern is formed is moved to the cleaning step, and the process can be finished as it is, and when the pattern is to be formed on another substrate, the printing plate is cleaned or replaced, and after replacing the substrate, the process is repeated. can do.

In the cleaning step, the ink pattern attached to the printing plate may be removed by a cleaning device using a cleaning liquid, or the ink pattern attached to the printing plate may be removed using a cleaning device using a printing roll and an adhesive tape. Of course, it is also possible to combine the two methods to perform the cleaning step.

As described above, when the color filter manufacturing method according to the present invention is used, the ink is coated on the surface of the printing roll or the surface of the blanket provided on the printing roll, and the surface of the blanket provided on the printing roll or the printing roll by the printing plate. After transferring the ink coated on the surface, the ink pattern remaining on the surface of the printing roll or the surface of the blanket provided on the printing roll can be printed on the substrate, and instead of cleaning the printing plate passing through each printing roll every time. Since the printing plate that has passed through all the printing rolls may be cleaned only once, the manufacturing time of the color filter can be shortened and the production cost can be reduced.

In addition, the coating coating on the printing roll, the coating of the printing roll may be transferred to the printing plate, and the process of printing the coating pattern remaining on the printing roll on the substrate may be performed in one step.

In addition, the red, green, and blue patterns can be continuously printed on one substrate, and the red pattern transfer, the green pattern transfer, and the blue pattern transfer and the cleaning of the printing plate can be performed continuously.

1 is an example of a printing method using a roll printing apparatus according to the present invention.

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

1: Blanket Roll

2: Red coating printing roll

3: Green coating printing roll

4: Blue coating printing roll

5: printing plate protrusion

6: printing plate groove

7: printing stage

8: substrate

9: substrate stage

10: print direction

(A): state before printing

(B): Red printed state

(C): Green printing state after the printing stage moves in a direction perpendicular to the printing direction

(D): Blue printing state after the printing stage moves in a direction perpendicular to the printing direction

Claims (7)

Board; A printing plate disposed in parallel with the substrate and having a pattern portion; A transfer device on which the substrate and the printing plate are mounted and which moves the substrate and the printing plate; N printing rolls rotatably installed; And a printing method using a roll printing apparatus comprising n coaters for coating a coating on the n printing rolls. N is a natural number of 2 or more, The printing method includes the steps of: (a) transferring the coating of the first printing roll to the pattern portion of the printing plate as the printing plate contacts and passes through the first printing roll; (b) transferring the coating pattern remaining on the first printing roll to the substrate as the substrate contacts and passes the first printing roll to form a first pattern; (c) moving the position of the printing plate after the first pattern forming step in a direction perpendicular to the moving direction of the substrate and the printing plate by the width of the first pattern; And (d) repeating steps (a) to (c) while sequentially forming the second to nth patterns with respect to the second to nth printing rolls using the printing plate as it is. After the nth pattern is formed, printing is terminated after the step (c), Before the printing plate is in contact with the first printing roll, the width of the first pattern to the n-th pattern is calculated in advance and the value is used to move the printing plate of step (c). The method according to claim 1, further comprising the step of coating the coating on the first to n-th printing roll by the first to n-th coater, respectively, before the printing plate is in contact with the first to n-th printing roll, respectively. Printing method characterized in that. The method of claim 1, wherein a blanket is prepared on each of the first to nth printing rolls before the printing plate is in contact with the first printing roll, and the first to nth colors are coated on the blanket at the same time. Characterized in that, a printing method. delete The method of claim 1, wherein n is 3 and the color of the coating comprises Red, Green and Blue. The printing method according to claim 1, wherein the pattern is a pattern of a color filter. delete

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