JP5434434B2 - Functional thin film printer - Google Patents

Description

  The present invention relates to a technique for correcting distortion in the width direction of a printed pattern that occurs when a fine pattern thin film is formed by a relief printing method.

  In recent years, the development of electronic devices using high-definition processing technology has made rapid progress. Such electronic devices are expected to contribute to the development of the next generation electronics field, biotechnology field, optronics field, and the like.

  Photolithography is generally used as a technique for forming a fine pattern with high positional accuracy while maintaining in-plane uniformity. However, in the patterning of the functional thin film, it is difficult to avoid the deterioration of the functional thin film in the photolithography process.

  Due to the problems of photolithography as described above, in recent years, direct patterning technology applying wet thin film fabrication technology has attracted attention.

  As the direct patterning method using the wet thin film manufacturing technique described above, techniques such as printing using a relief printing method, an intaglio printing method, a planographic printing method, and a screen printing method, and a technique such as an inkjet method are mainly used.

  Applications of these printing technologies include color filters for liquid crystal displays (LCD), light emitting layers of organic electroluminescence (EL) elements using wet methods, charge transport layers, electrode patterns on organic thin film transistor substrates, organic semiconductor materials, etc. There is.

  As described above, printing as a high-definition patterning technique can be performed by various methods, but among them, the apparatus is simple, the substrate to be printed is not limited, and the number of liquid contact members is small. The letterpress printing method has attracted attention as a printing method having excellent characteristics such as being hard to cause deterioration of the characteristics of the functional thin film due to elution.

  In general letterpress printing devices, ink is transferred to the surface of a letterpress wound around a cylindrical plate cylinder from an anilox roll that supplies a predetermined amount of ink to the plate, and linearly operates in synchronization with the operation of the plate cylinder. Ink is transferred to a substrate such as glass placed on a moving surface plate.

  As described above, due to the characteristic that the pattern transferred to the plate is transferred directly to the substrate, the accuracy of the plate, the straightness of the moving surface plate, the plate cylinder, are factors that determine the position accuracy of the printing pattern in the relief printing method. There are accuracy of rotation speed and surface plate moving speed.

  As a plate generally used in the relief printing method, a plate in which a photosensitive resin is applied to one surface of a plate-like base material made of metal or resin and unevenness is patterned by photolithography is used. In particular, when a metal is used as a substrate, a plate can be created with an accuracy of a positional deviation of 3 μm or less with respect to a design value by using a proximity exposure apparatus or a projection step exposure apparatus.

On the other hand, the letterpress produced as described above needs to be wound around a plate cylinder of a printing press when it is used. During this winding, the pattern of the plate is distorted due to the stress applied to the plate and the distortion of the plate cylinder that is the object of winding, and the printed pattern transferred to the non-printed material is the pattern of the plate before being attached to the plate cylinder. It becomes a different distorted pattern.
In addition, the pattern expands more than the case where it is placed on a flat surface by winding, and this causes a printing position error in the flow direction (moving direction of the substrate).

In addition, the movable surface plate on which the printing material is placed is driven by a linear servo motor or the like and moves linearly. The straightness of the linear motion depends largely on the accuracy of the linear guide attached to the surface plate, and generally the straightness is often ± 2 μm / m or more.
For this reason, the positional accuracy of the printing pattern in the width direction (direction perpendicular to the moving direction of the substrate) depends on the straightness of the surface plate.

As described above, there are two types of positional deviation of the printing pattern generated in the relief printing method, the deviation in the flow direction and the deviation in the width direction.
Here, the printing position misalignment in the flow direction can be corrected relatively easily by adjusting the rotational speed of the plate cylinder and the moving speed of the surface plate and relatively changing the length of the transferred pattern. It is possible.

  On the other hand, misalignment in the printing direction in the width direction is observed as distortion that occurs when the plate is wound around the cylinder and distortion that overlaps the accuracy of the straightness of the moving surface plate on which the substrate to be printed is placed. Even if the improvement of the generated distortion and the improvement of the distortion accompanying the printing operation are performed separately, a sufficient effect cannot be obtained, and the problem of the printing position accuracy has not been solved so far.

  For such a problem, for example, in Patent Document 1, it is proposed to correct the distortion by applying stress to the printing plate or the substrate (substrate) against the distortion of the printing plate or the printing press measured in advance. Has been. However, when partial stress is applied to the plate or the substrate, complicated distortion occurs, and as a result, a more complicated distortion than the original distortion occurs in the printed material. It ’s difficult.

JP 2005-053205 A

  As described above, the conventional relief printing method is a printing method having excellent characteristics, but does not sufficiently satisfy the characteristics required in terms of printing position accuracy. An object of the present invention is to provide a printer capable of solving such problems and printing a functional thin film with high accuracy.

  In order to solve the above problems, as a result of intensive studies by the present inventors, the distortion in the width direction of the printed matter is changed by operating the plate cylinder or the moving surface plate in the width direction during the printing operation. Was found. Based on this result, it became clear that it is possible to improve the accuracy of the printed material by moving the plate cylinder or moving platen in the width direction during the printing operation based on the distortion of the printed material measured in advance. It was.

The present invention has been made based on such knowledge, and the invention according to claim 1 for solving the above-described problem is a relief printing press for forming a functional thin film on a substrate, A cylindrical plate cylinder having a relief plate on which the printing pattern is formed on the outer peripheral portion, an anilox roll for supplying ink to the relief plate, an ink supply device, and a positioning fixed for placing a substrate to which the ink of the relief plate is transferred In a printing apparatus comprising a panel,
A measurement value input mechanism for inputting the measurement value of the width direction position of each predetermined point of the print pattern measured in advance and the current flow direction position;
A correction control mechanism that calculates a shift in the width direction at each point based on the measurement value, and determines a movement amount in the width direction at each point so as to eliminate the shift;
A correction mechanism for operating both or one of the cylindrical plate cylinder and the positioning surface plate based on the amount of movement;
A letterpress equipment, which comprising the.

By providing the correction mechanism of the present invention, the width direction printing position accuracy, which has been a problem in the conventional relief printing apparatus, is improved, and the target accuracy can be achieved.

It is sectional drawing of the printing apparatus which is embodiment of this invention. 1 is a top view of a printing apparatus according to an embodiment of the present invention. It is a schematic diagram for demonstrating "straight advance".

  Hereinafter, the high-precision relief printing apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a high-precision relief printing apparatus 100 of the present invention, and FIG. 2 is a top view.

  The high-precision relief printing apparatus 100 includes a base surface plate 101 and linear guide rails 102A and 102B having substantially the same length as the entire length in the longitudinal direction of the base surface plate 101. The guide rails 102A and 102B are arranged and fixed in parallel with a predetermined distance on the upper surface of the base surface plate 101.

  Mounted on the guide rails 102A and 102B is a movable carriage 103 that can move linearly along the guide rails 102A and 102B. The moving carriage 103 is driven by a linear servo motor 104 with high movement speed and positioning accuracy.

  On the movable carriage 103, a positioning surface plate 105 on which a substrate to be printed is placed is installed. The positioning surface plate 105 performs an alignment operation for matching the position of the printing plate with the position where the printing pattern is to be transferred on the substrate to be printed and the printing correction operation of the present invention described later.

  The positioning surface plate 105 is mounted on the moving carriage 103 via guide rails 106 attached to three places on the moving carriage 103. The positioning surface plate 105 moves freely along the XYθ axes, and is driven by a mechanism that rotates a ball screw mechanism by a servo motor or a linear servo motor.

  The positioning surface plate 105 is provided with a detector 108 for detecting the surface plate position. As the detector 108, either a contact type or a non-contact type can be used as long as it has a resolution of 0.1 μm or more.

  A cylindrical plate cylinder 109 is supported at a central portion of the base surface plate 101 in a state that it is orthogonal to the guide rails 102A and 102B and is rotatable through a bearing.

  The printing plate 110 is wound around the cylindrical surface of the cylindrical plate cylinder 109. If the printing plate 110 is installed in a slack state with respect to the cylindrical surface of the cylindrical plate cylinder 109, the printing accuracy will be adversely affected when the ink supplied to the printing plate 110 is transferred onto the substrate to be printed. Effect. Therefore, the printing plate 110 is wound while applying tension.

  An ink supply unit 111 that supplies ink onto the printing plate 110 is installed adjacent to the plate cylinder 109. The ink supply unit 111 includes an anilox roll, a doctor blade, and an ink chamber. Ink is supplied from the ink chamber onto the cylindrical surface of the anilox roll, and a certain amount of ink is left on the cylindrical surface of the anilox roll by scraping off excess ink on the cylindrical surface of the anilox roll with a doctor blade. In this state, the ink is supplied onto the printing plate 110 by rotating the anilox roll and the plate cylinder 109 while bringing the anilox roll cylindrical surface into contact with the printing plate 110.

  A servo motor 113 that rotates the plate cylinder is installed outside the bearing on one side of the cylindrical plate cylinder 109 so as to be directly connected to the cylinder shaft. The direct connection portion is provided with a play of about 10 μm in the axial direction. Using this play, the printing cylinder is moved in the axial direction by an actuator to perform a printing correction operation.

  The actuator 112 is disposed outside the other bearing of the cylindrical plate cylinder 109, and moves the plate cylinder in the axial direction thereof. As the actuator 112, it is desirable to adopt a moving mechanism that can move the plate cylinder in the axial direction by 1 to 10 μm and has a positional accuracy of 1.0 μm or less (preferably a positional accuracy of 0.5 μm). For example, a ball screw mechanism, a linear servo mechanism, or the like can be used.

  In order to detect the position of the plate cylinder, a measuring machine 114 for measuring the position in the plate cylinder width direction is installed on the side surface of the plate cylinder. As the measuring device 114, any method can be used as long as it can detect the movement of the plate cylinder in units of 1 μm, but it is preferable to use a non-contact method such as a laser displacement meter.

  Furthermore, the relief printing apparatus of the present invention includes a control mechanism for operating the above-described correction mechanism in addition to a general printing press control apparatus. That is, it is a mechanism for instructing an appropriate correction amount to the correction mechanism during a printing operation based on the distortion information of the printed matter measured in advance. When actually correcting printing, only one or both of the correction mechanisms of the positioning surface plate 105 and the plate cylinder 109 can be used.

  Next, the operation will be described. First, a printing operation when no correction operation is performed will be described.

  After the printing substrate on which the alignment pattern is formed at a predetermined interval is placed on the positioning surface plate 105, vacuum suction is performed so that the printing substrate does not move.

  The positioning surface plate 105 on which the substrate to be printed is mounted moves by driving the servo motor 104 while being placed on the movable carriage 103 to the position immediately below the alignment camera 115 by inputting a print start operation instruction on the control panel. .

  The alignment operation is performed by imaging the alignment mark on the substrate to be printed with the alignment camera 115 installed on the base surface plate 101, and adjusting the position with the positioning surface plate 105 so that the alignment mark enters a specified position in the alignment camera field of view. It is to do. As a method for determining the position of the alignment mark camera 115, printing is performed without first performing alignment, the printing position on the positioning surface plate 105 is confirmed, the alignment camera is moved with respect to the printing position, and the specified position is reached. Is to decide.

  After the alignment is determined, the movable carriage 103 moves toward the lower part of the plate cylinder 109 at a preset operation speed (printing speed). The plate cylinder 109 rotates in synchronization with the moving speed, and the convex portion of the printing plate 110 comes into contact with the anilox roll and is inked, and then placed on the moving carriage 103 that moves in synchronization with the moving speed of the plate cylinder 109. Ink is transferred to the printed substrate, and the printing operation is completed.

  Next, printing when the correction mechanism in the main printing is operated will be described.

  In order to operate the correction mechanism, length measurement is first performed on a printed matter created by the above-described normal printing procedure using a length measuring machine. The measured values are the width direction position x of each predetermined point in the print pattern and the flow direction position y at that time. This data is input to the correction controller.

  With respect to the input measurement value, the correction control device measures the width of each point measurement value (width direction position x and flow direction position y) from a straight line connecting the transfer start point and transfer end point of the print pattern. A process for calculating the amount of deviation in the direction is performed.

  The correction control mechanism determines the movement amount of the correction mechanism at the flow direction position y of each point based on the calculated shift amount in the width direction. In other words, at the position y in the flow direction of each point, the printed material correction mechanism provided on the positioning surface plate or the plate cylinder is operated in the opposite direction to the position displacement direction in the width direction by the same amount as the position displacement amount in the width direction. Let

  As the operation of the correction mechanism between the measurement points, the correction mechanism operates along a curve obtained by interpolating between the measurement points.

The printing for performing the correction operation takes the same procedure as in the case of the normal printing described above until the alignment is completed. Alignment is completed, and the correction mechanism is operated with the point where the relief on the plate cylinder contacts the substrate as a trigger. As a mechanism for detecting the contact between the convex portion of the relief plate and the substrate, a method of measuring whether the plate cylinder or the positioning surface plate slightly floats or sinks when the convex portion contacts may be used.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

First, the case where the positioning surface plate 105 is used as a correction mechanism in the relief printing apparatus 100 with the correction mechanism shown in FIGS.

  First, normal printing for performing the alignment operation will be described.

First, as a plate material, a black oil-based dye was applied as a reflection suppressing layer to the surface of a 0.2 mm thick SUS304 plate by a die coating method so as to have a thickness of 1.5 μm. A negative photosensitive resin mainly composed of polyamide was applied on the surface of this laminate so that the total thickness was 0.1 mm, and used as a base of the plate.

  The plate material thus prepared is exposed by opening a gap of 100 μm with a proximity exposure apparatus using a photomask in which a cross with a width of 30 μm is provided within a range of 300 mm square and a pitch of 10 mm, and exposure is performed. The developed plate was developed with warm water to obtain a relief plate.

  When this relief printing plate was measured with a length measuring device, the linearity was 2 μm. Here, the linearity means that the periodic pattern formed on the printing plate has the same position in the width direction, and the position in the flow direction connects the predetermined points of the pattern on the printing start side and the printing end side with a straight line. The sum of the straight line and the maximum value in the left-right direction of the difference between the predetermined points of the patterns other than the print start side and the print end side (see FIG. 3). This correction mechanism mainly improves the linearity value.

  The relief plate was wound around and attached to a printing press plate cylinder.

  As a printed member, a substrate having a pattern made of a photosensitive resin on a raw glass was prepared.

  An organic light-emitting ink in which a polyphenylene vinylene derivative, which is an organic light-emitting material, was dissolved in toluene so as to have a concentration of 2% was charged as an ink into the ink chamber.

  After placing the patterned glass on the positioning surface plate, printing was performed at a printing speed of 100 mm / s without an alignment operation and a correction operation.

  By moving the alignment camera while the produced printed matter was fixed to the positioning surface plate, the printing position of the printed matter and the alignment camera axis were aligned to set the alignment camera specified position.

  Next, after performing the alignment operation, printing was performed. When the finished printed matter was measured with a length measuring machine for liquid crystal substrates, the linearity was 10 μm.

  The amount of deviation from the design value at each point was obtained from the length measurement data, and input to the correction control device. The operation amount of the correction mechanism is determined by the correction control device based on the input data.

  As a print correction mechanism in the present embodiment, a method of correcting using a positioning surface plate was used. A linear servo motor (resolution: 0.5 μm) was used as a driving method for the positioning surface plate. In addition, as a position detector for the positioning surface plate, a contact type (differential coil system, resolution 0.1 μm) was installed on both sides in the width direction of the positioning surface plate.

After placing the substrate and performing the alignment operation, the correction mechanism was operated to perform printing. When the printed substrate was measured, it was confirmed that the linearity was improved to 3.0 μm, and it was also confirmed that there was no influence on the printed matter.

  As a correction mechanism in the first embodiment, a method of moving the plate cylinder in the axial direction was used.

  A ball screw mechanism was used as a method for operating the plate cylinder shaft. A laser displacement meter was used as a means for measuring the amount of movement of the plate cylinder in the axial direction. Since the plate cylinder end face has an uneven portion, the difference from the previously measured plate cylinder data was taken and the amount of movement was measured.

  In the actual printing operation, the correction mechanism is operated based on the value input to the correction control mechanism, as in the case of using the positioning surface plate of the first embodiment.

When the substrate was made by operating this mechanism and the length was measured, the linearity was 3.0 μm, and the influence on the printed matter was not confirmed.

DESCRIPTION OF SYMBOLS 100 High-precision letterpress printing apparatus 101 Base surface plate 102 Guide rail 103 Moving carriage 104 Linear servo motor 105 Positioning surface plate 106 Positioning surface plate guide rail 107 Positioning surface plate driving linear servo motor 108 Positioning surface movement amount monitoring sensor 109 Plate Cylinder 110 Printing plate 111 Inking unit 112 Plate cylinder operating mechanism (correction mechanism)
113 Servo motor for driving plate cylinder 114 Displacement meter 115 using plate cylinder movement amount Alignment camera

Claims (1)

A relief printing machine for forming a functional thin film on a substrate, at least a cylindrical plate cylinder having a relief printing plate with a printing pattern formed on its outer periphery, an anilox roll for supplying ink to the relief printing plate, and ink supply In a printing apparatus comprising an apparatus and a positioning surface plate on which a printing material onto which the relief printing ink is transferred is placed,
A measurement value input mechanism for inputting the measurement value of the width direction position of each predetermined point of the print pattern measured in advance and the current flow direction position;
A correction control mechanism that calculates a shift in the width direction at each point based on the measurement value, and determines a movement amount in the width direction at each point so as to eliminate the shift;
A correction mechanism for operating both or one of the cylindrical plate cylinder and the positioning surface plate based on the amount of movement;
A letterpress printing apparatus comprising:

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