JP2008000927A - Relief printing plate for forming micropattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relief printing plate for forming micropatterns, which suppresses marginal zones. <P>SOLUTION: Transferring to a board is performed by feeding a pattern forming ink to the tips of the relief surfaces 2 of the relief printing plate under the condition that projections 3 are provided on the relief surfaces 2 of the relief printing plate. Since the flowing of the ink staying in grooves 4 between the projections at the tip parts is restricted by the projections 3, resulting in restricted flow by the projections 3, a transferring, in which the marginal zones are suppressed from developing, is realized. A uniformly thick film having a transferred ink is thereby obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a relief printing plate used for relief printing such as flexographic printing.

Conventionally, a photolithographic method has been generally used for a display panel, circuit pattern formation, and the like having a fine size. Compared to the photolithographic method, the printing method is expected to reduce costs such as faster processing speed, less waste related to the process, and higher material utilization efficiency, but it has not been able to meet the requirements.
FIG. 2 is a diagram showing a relief printing plate used for relief printing and problems. Conventionally, a relief printing method in which the ink 6 is attached to the tip of the relief 10 and is pressure-transferred to a printing substrate has been widely used. A typical example of such a relief plate is a flexographic printing method using a resin material for the plate. Since the plate is a resin, the processing is relatively easy, the plate material is flexible, the damage to the substrate, the damage to the previously formed pattern during overprinting is reduced, relief printing Therefore, there is a feature that ink does not adhere to the non-image area. These features are advantageous when applied to electronic devices.

However, letterpress and letterpress printing methods have hardly been used as means for printing fine patterns. The main reason is that there is a problem peculiar to this method of generating a marginal 7, and it is difficult to form a fine pattern accurately. In the relief printing system, printing pressure must be applied in the process of transferring the ink (FIG. 2B), but the ink sandwiched between the relief 2 of the printing plate and the substrate 5 protrudes around the relief tip. It becomes difficult to maintain a predetermined dimension. A portion where the printed pattern is larger than the pattern on the printing plate is referred to as a marginal 7. Further, when the pattern becomes finer and the distance between the patterns becomes smaller, there arises a problem that the adjacent pattern is connected by the marginal 7. (FIG. 3A) In particular, when a conductive pattern such as a wiring or an electrode is formed, if the pattern is connected, a short circuit occurs, and there is a problem that it cannot function normally.
Japanese Patent No. 3475498 JP 2002-117755 A JP 2002-178654 A JP 2004-237545 A

  So far, the following methods have been proposed to reduce the marginal. However, in the method of transferring the solidified ink component to the substrate through the adhesive substance after the ink is hardened at the convex portion of the plate to prevent marginal (see Patent Document 1), the pattern previously formed in an electronic device or the like When electrical connection is required between the pattern formed later and the pattern formed later, the mutual conductivity decreases, and in the lamination with the insulating layer, the influence on the device characteristics due to the trap generation at the interface, In the transfer of a thin film that is weak in strength, there may be a problem that cracks are caused in the film due to stress during the transfer. A method of providing a barrier around the convex portion of the plate has also been proposed (see Patent Document 2). However, when the viscosity of the ink is low, the pressure on the workpiece becomes uneven, and when there is already a pattern, the barrier is caused by a step. There is concern about the problem of flowing out without being able to hold down.

In order to solve the above problem, a method has been proposed in which a depression is formed in the convex portion of the plate (see Patent Document 3), and excess ink is accommodated therein. However, in the case of repeated printing, it is necessary to satisfy the condition that there is no ink in the dent in order to accommodate excess ink, but there is anxiety about ink remaining, and the durability of the effect is reduced during repeated printing. Concerned. A method of providing minute protrusions or protrusions on the convex portions of the plate has also been proposed (see Patent Document 4), but in the case of minute protrusions, the shape is not formed along the edge portion but formed on the substrate. I am worried about the reproducibility of pattern edges.
Accordingly, the present invention has an object to solve the problems of the prior art as described above, and to provide a printing plate that is optimal for the formation of wirings, electrodes, insulating materials, functional materials and electronic circuits in display panels. To do.

In order to solve the above problems, the present invention has the following configuration. That is, the plate of claim 1 according to the present invention is a printing relief plate for transferring ink supplied onto a relief of the plate to a printing medium, wherein a plurality of protrusions are formed on the relief, The relief printing plate is characterized in that the shape of the protrusion around the top of the protrusion of the protrusion has a line portion along the shape of the relief end.
A printing plate according to a second aspect of the present invention is the printing relief plate according to the first aspect, wherein the line portion has a straight line or a curve.
According to a third aspect of the present invention, in the printing relief plate according to the first or second aspect, the shape around the top of the protrusion other than the relief end is the same as the protrusion at the end, or It is a relief printing plate characterized by having different shapes.

According to a fourth aspect of the present invention, in the printing relief plate according to any one of the first to third aspects, a surface free energy difference between the relief top surface and the relief groove is 5 × 10 ⁻² mJ /. It is a relief printing plate characterized by being m ² or more.
The printing plate according to claim 5 according to the present invention is the printing relief plate according to claim 4, wherein the relief top surface repels ink and the relief groove portion wets with ink. is there.
The printing plate according to claim 6 according to the present invention is the printing relief plate according to claim 4, wherein the relief top surface is wetted with ink and the relief groove is repelled with ink. is there.

The printing plate according to claim 7 according to the present invention is the printing relief plate according to claim 4, wherein the surface free energy of the surface of the relief top is smaller than the surface free energy of the relief groove. is there.
The printing plate according to claim 8 according to the present invention is the printing relief plate according to claim 4, wherein the surface free energy of the top surface of the relief is larger than the surface free energy of the relief groove. Letterpress.

  When pattern formation is performed using the printing plate of the present invention, the protrusions provided at the relief tip of the relief plate work to prevent the ink from flowing out during printing, so that the marginal is suppressed and the patterns are connected in pattern formation. Therefore, it can be applied to electronic devices (wiring, electrodes, insulating materials, functional elements and circuit formation using functional materials) by printing.

The “letter for fine pattern formation” of the present invention will be described. FIG. 1 is a view showing a state in which a plurality of quadrangular prism protrusions are formed on a relief of a relief plate and arranged in a grid pattern.
FIG. 1A shows a cross section of a relief, 3 is a protrusion, and 4 is a groove. FIG. 1B shows the surface on which the relief ink adheres, wherein 3 is a protrusion and 4 is a groove.
6 and 7 are diagrams for explaining that a plurality of protrusions are formed on the relief of the present invention, and a protrusion having a line portion along the shape is formed at the relief end.
FIG. 6A is a diagram in the case where the grid is arranged in a grid pattern, the projections are quadrangular prisms, and the shape of the relief end is a straight line, and the projection arrangement direction is the same. FIG. 6B is a diagram illustrating a state in which the shape of the relief end portion includes a part of an oblique straight line with respect to the arrangement direction of the protrusions. In this case, the protrusion on the relief end portion of the oblique straight line portion has a shape cut off at the oblique straight line portion. A portion corresponding to the cut-off portion becomes a line portion along the shape of the relief end portion. FIG. 6C is a diagram showing a state in which the shape of the relief end part includes a part of a curve. The protrusion on the curved portion has a shape cut off at the curved portion at the relief end, and this portion becomes a line portion along the shape of the relief end. FIG. 6D is a diagram showing a case where the protrusion is a cylinder. The protrusion on the relief end becomes a shape cut off at the relief end, and this portion becomes a line segment along the shape of the relief end. FIG. 6E is a diagram showing a state where protrusions are formed on a curved relief. A protrusion is formed along the curve of the relief, and the protrusion coincides with the relief shape and has a line portion along the relief.

FIG. 7 shows an arrangement aimed at suppressing the flow of ink more effectively by devising the arrangement of the protrusions.
FIG. 7A shows an example in which a quadrangle (b) shows a state in which circular protrusions are arranged in a staggered manner. FIGS. 7C and 7D are views showing a state in which the protrusions are arranged in a direction to further block ink that flows out of the pattern. FIG. 7C shows a state in which the protrusion shape is a rectangle and the long side is arranged in a direction along the shape of the relief end. FIG. 7D shows a state in which the protrusion shape is an arc, and the arc is arranged in a direction along the shape of the circular relief end. In any case, the shape around the top of the protrusion at the relief end is formed so as to have a line portion along the shape of the relief end.
Next, we will describe how to make the plate. There are (1) a method of forming by light, (2) a method of replicating from a mold, and (3) a method of forming by engraving.

(1) In the method of forming by light, a photosensitive resin can be used, and examples of the method include the following methods. According to a method using a normal photosensitive resin, a negative film is prepared in accordance with the shape of the relief, which transmits light in a portion corresponding to a fine protrusion and does not transmit in other portions. When a liquid photosensitive resin is used before exposure, after laminating this negative film on the surface of the glass plate, a liquid photosensitive resin is applied thereon, and a transparent base film is laminated on the surface. Laminate a glass plate. Note that the thickness of the photosensitive resin layer is set to a predetermined dimension. Next, using a lamp, ultraviolet rays are irradiated through the upper glass plate and the base film, and ultraviolet rays are irradiated through the lower glass plate and the negative film. A well-known irradiation light source for image exposure can be used.
A portion where a predetermined amount of light entering from the entire upper surface of the layer made of the liquid photosensitive resin and light transmitted through the portion of the negative film transmitting light reaches is cured. After curing, the upper and lower glass plates and the negative film are removed, the uncured portion is washed and removed, and ultraviolet rays are irradiated to the relief forming side to accelerate the curing to obtain a printing plate.
Alternatively, for relief formation, a laser light source having a wavelength capable of curing the photosensitive resin may be used to scan and expose a light amount necessary for curing. When using a photosensitive resin that is not a liquid type at room temperature but a solid solution at room temperature, after heating to form a predetermined thickness, operations after image exposure may be similarly performed. Furthermore, although the above is a manufacturing method when using a negative type photosensitive resin, it is also possible to use a positive type photosensitive resin together with a positive film.

  (2) As a method for creating a replica from a mold, the following method can be cited. Create a mold corresponding to the pattern, and mold it using a method suitable for the resin. As a method, 1) a photocuring method and 2) a thermosetting method can be employed. Alternatively, a heated mold may be pressed against the resin to give a shape corresponding to a pattern, and 3) a thermal transfer method (also referred to as a cooling solidification method). Photosensitive resins can be used for 1), 2) can be liquid or solid solution thermosetting resins at room temperature, and 3) can be thermoplastic resins. The mold may be selected from known ones depending on the processing method employed and the resolution. Metal molds, Si molds, quartz molds, SiC molds, Ni electric molds, resin molds, and the like can be used.

(3) As a method of forming by engraving, the following method can be exemplified.
It is possible to cope with a crosslinked rubber-based material, a cured thermosetting resin, a similarly cured photocurable resin, a thermoplastic resin, and the like. Examples of a method for engraving a solid plate material include a laser engraving method. In reality, the lasers may be properly used according to the dimensions of the required shape. Carbon dioxide laser, VAG 3rd or 4th wave laser, and excimer laser can be selected and engraved according to resolution and engraving property. By using this method, it is possible to produce a combination plate in which the surface free energy of the relief top surface and the groove are different. A method in which different materials are laminated at the relief tip and below, or different combinations of surface free energy are created on the surface and lower layers by applying different materials or plasma treatment, and engraving to reach the lower layer with a laser. It can also be taken.

The material of the present invention includes a thermoplastic resin that is solid at room temperature and fluid at high temperature, a viscous resin at room temperature, or a solid solution photosensitive resin, and a thermosetting resin as described above. Can be molded. There are no particular restrictions on the type of resin. The mechanical properties such as hardness, Young's modulus, rebound resilience, tensile strength / elongation, surface tension, and solvent resistance in the form used as the plate may be selected and designed so as to suit the desired printing.
As the negative photosensitive resin, a radical polymerization system, a photocationic polymerization system, a photoanion polymerization system, a photodimerization reaction system, and the like are applicable. Hereinafter, a general-purpose radical polymerization system will be described.

Although many radically polymerizable resin compositions can be applied to the present invention, among them, a composition containing a prepolymer, a monomer, an initiator, and a polymerization inhibitor can be used as a representative one.
The prepolymer is a radical polymerizable resin composition containing a prepolymer having at least one polymerizable double bond in the molecule, a photopolymerization initiator, and an ethylenically unsaturated monomer having a polymerizable double bond, for example, Examples of the prepolymer include those using at least one kind of unsaturated polyester, unsaturated polyurethane, unsaturated polyamide, unsaturated polyacrylate resin, unsaturated methacrylate resin, and various modified products thereof. For example, the photosensitive resin composition among them is described in many known documents such as JP-A-52-90804, JP-B-48-19125, JP-A-49-109104, JP-B-48-41708. The photosensitive resin which can be illustrated can be illustrated (refer literature mentioned later).

  As monomers, ethylenically unsaturated monomers having a polymerizable double bond include styrene, chlorostyrene, vinyl toluene, diallyl phthalate, diallyl isophthalate, triallyl cyanurate, N, N′-methylenebisacrylamide, methacryl Amide, N-hydroxyethylacrylamide, N-hydroxymethacrylamide, α-acetamide, acrylamide, acrylic acid, methacrylic acid, α-chloroacrylic acid, paracarboxystyrene, 2,5-dihydroxystyrene, triethylene glycol diacrylate, triethylene glycol "Ethylene glycol dimethacrylate, etc." and "Photopolymer Handbook", "Photopolymer Handbook", published by Industrial Research Co., Ltd., June 26, 1989, p. The material described in 31-36 can be used.

  As the initiator, when these are subjected to a three-dimensional crosslinking reaction using an ethylene addition polymerizable unsaturated group, it is preferable to use a known photopolymerization initiator in terms of reaction efficiency. As radical photopolymerization initiators, benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, Michler ketone, xanthone, thioxanthone, chloroxanthone, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, benzyl, 2,2-dimethyl- 2-hydroxyacetophenone, (2-acryloyloxyethyl) (4-benzoylbenzyl) dimethylammonium bromide, (4-benzoylbenzyl) trimethylammonium chloride, 2- (3-dimethylamino-2-hydroxypropoxy) -3-, 4-Dimethyl-9H-thioxanthone-9-one-mesochloride, 1-phenyl-1,2-propanedione-2- (Obenzoyl) oxime, thiophenol, 2-benzothiazole Thiol, 2-benzoxazole thiol, 2-benzimidazole thiol, diphenyl sulfide, decyl phenyl sulfide, di-n-butyl disulfide, dibenzyl sulfide, dibenzoyl disulfide, diacetyl disulfide, dibornyl disulfide dimethoxyxanthogen disulfide, tetramethylthiuram Examples thereof include monosulfide, tetramethylthiuram tetrasulfide, benzyldimethyldithiocarbamate quinoxaline, 1,3-dioxolane, N-laurylpyridinium and the like.

As the thermal polymerization initiator, known ones such as peroxides such as benzoyl peroxide, 2,2-azobisisobutyronitrile, persulfate-sodium hydrogensulfite, azo compounds, and redox initiators can be used.
Specifically, Toray Research Center, Research and Research Division, “New Development of Photopolymer Technology” published by Toray Research Center, March 10, 1993, p. Page 35, supervised by Atsuo Yamaoka, “Basics and Applications of Photopolymers”, CMC Publishing, March 27, 2003, Chapter 4 Platemaking Materials and Photoresist, Supervised by Shinji Matsui et al., “Development and Application of Nanoimprints”, CMC Publishing, August 31, 2005, p. 50, p. 151, the materials described. Similarly p. 158, p. 159, acrylates and methacrylates having a fluorine-modified fluoroalkyl group, and fluorine-containing epoxy-based photosensitive resins can also be used.
Further, a photopolymerizable rubber composition comprising at least a monomer having a polymerizable double bond with an unvulcanized rubber and a polymerization initiator, a so-called photosensitive elastomer (for example, JP-A-51-106501, No. 47-37521) and a balance with ink-generating properties are necessary, but dialkyl silicone resins can also be used.

  As thermoplastic resins, polymethyl methacrylate (PMMA), polycarbonate (PC), cyclic polyolefin resin (COP), polyamide (PA), polyacetal (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polymethyl Pentene (TPX), modified polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyetherimide (PEI), polyarylate (PAR), polysulfone (PSF), polyether sulfone (PES), polyamideimide (PAI), polyethylene (PE), polypropylene (PP), polystyrene (PSt), vinyl chloride (PVC), vinylidene chloride (PVDC), acrylonitrile / Tylene (AS), acrylonitrile / butadiene / styrene (ABS), fluorinated resins such as vinylidene fluoride (PVDF), tetrafluoroethylene / norbornene copolymers, fluorine-containing acrylic resins, fluorine-containing acrylic resins, Fluoropolyimide resin, fluorine-containing vinyl ether resin, and other materials that can be processed by heat, Tadahiro Miwa, “Science of Basic Synthetic Resins”, Gihodo Publishing Co., Ltd., June 15, 1987, p. 113-397, discussions 1. Polymerization type resin The thermoplastic resin described in the condensation type resin may be used.

As thermosetting resins, unsaturated polyesters, unsaturated polyurethanes, unsaturated polyamides, unsaturated polyacrylates, unsaturated methacrylates, resins and various modifications thereof, and ethylenically unsaturated groups having polymerizable double bonds A radical polymerizable resin composition containing a thermal polymerization initiator in the monomer, a resin composition obtained by adding a curing agent to epoxy, or a silicon-based polydimethylsiloxane resin may be used.
In the fluororesin, a thermosetting resin using a cross-linking material, a fluorine monomer containing a polymerization initiator that generates radicals by heat, or a fluorine-containing oligomer may be used. Other than this, Tadahiro Miwa, “Science of Basic Synthetic Resins”, Gihodo Publishing Co., Ltd., June 15, 1987, p. 240-397 details The thermosetting resin described in the condensation type resin may be used.
Natural rubber, butadiene, isoprene, chloroprene, butyl, ethylene propylene, styrene butadiene, polyisobutylene, styrene butadiene, nitrile, acrylic, epichlorohydrin, chloroprene, urethane, nitrile, silicon, fluorine rubber are used as rubber materials. May be. By using the methods and materials described above, the relief printing plate according to the present invention can be made.

Next, the printing press will be described. A commercially available printing machine shown in FIG. 9 can be used. This is an example and is not limited to this method.
Printing is performed as follows. 9 is used, ink is placed on the anilox plate 11 having unevenness, the ink is measured by pulling the doctor blade 12 in the direction 13, and the plate 14 is brought into contact with the anilox plate 11. After separation, the ink adheres to the grooves between the protrusions formed on the relief and the upper surfaces of the protrusions. In this state, the pressing ink is transferred to the substrate 5. Thereafter, the ink leveling proceeds and becomes uniform. FIG. 10 is an enlarged view of the plate portion, and the ink developed on the anilox plate of the printing machine (a) is supplied to the relief of the plate as shown in (b) and (c). FIGS. 7A to 7F are diagrams showing a process until a pattern is formed by being transferred to a substrate as shown in FIGS. FIG. 10A shows a state where the ink is spread on the anilox plate of the printing press and the plate 13 before the ink is supplied.

  Next, in order to transfer the ink to the relief, as shown in FIG. 10B, the relief tip of the plate is pressed against the anilox plate on which the ink has been developed. At this time, the ink moves to the groove between the protrusion formed at the relief tip and the tip of the protrusion. FIG. 10C shows a state in which ink is supplied to the relief tip of the plate and the substrate to be printed. Thereafter, in order to transfer the ink to the substrate, the relief tip is pressed against the substrate as shown in FIG. FIG. 10E shows a state in which the relief of the plate has been released from the substrate and the ink has been transferred to the substrate. Further, FIG. 10F shows a state in which the ink leveling has progressed on the substrate and a pattern has been formed. A pattern is formed by printing by the above method.

According to the present embodiment, by providing the protrusion on the relief, the flow of ink to the outside of the relief that occurs when pressed is prevented, so that the occurrence of marginal can be reduced. Since the protrusion having the line portion along the shape is arranged at the relief end portion, the reproducibility of the pattern is also improved.
Next, the shape of the protrusion will be described. The planar shape can be circular, triangular, quadrangular, hexagonal, or more polygonal, straight, or curved shapes, but it can be used with the volume of the groove for storing ink, an anilox plate for ink transfer, etc. It may be determined in consideration of moire and spots, transferability of ink from the anilox plate, leveling condition after printing, and transfer efficiency of ink to the substrate. Further, the protruding side wall may be inclined. By providing the inclination, there is an advantage that the transfer efficiency of the ink is improved. The amount of ink can be adjusted by changing the configuration, the arrangement interval (groove width), and the depth of the protrusions. Of course, these configurations may be changed within one pattern.

Regarding the arrangement, it is also possible to take a staggered arrangement in addition to FIGS. 6 (a) and 6 (b) and FIGS. 7 (a) and 7 (b). For example, in the staggered arrangements of FIGS. 7 (a) and 7 (b), the projection distance is made more uniform, so that the leveling property is improved, and the adjacent projections are deviated from the grid arrangement, so that the ink flow in that direction is suppressed. It is considered effective.
Although the size of the top of the protrusion depends on the pattern size to be formed, for example, the number of lines arranged in the width direction of the linear relief of the pattern is preferably at least two, considering the uniformity of the edges and the inside of the pattern, preferably 3 or more is good. For example, in the case of a line having a width of 50 μm, when three or more lines are arranged, if the pitch is 20 μm and the widths of the groove and the top are made equal, the width of the protrusion is 10 μm. Similarly, in the case of a line having a width of 25 μm, when three protrusions are arranged, the pitch is 10 μm and the protrusions are 5 μm. The size of the protrusion in the longitudinal direction of the relief is basically the same as that in the width direction, but it is not necessarily required to be the same. The size of the protrusions and the interval between the protrusions may be adjusted in consideration of conditions such as the required pattern width and thickness, ink viscosity, ink leveling properties, density, amount of ink placed on the plate, and marginal conditions. It is not limited to the above range.

The plate making method may be selected depending on the required pattern size and projection size.
Further, the preferable volume of the groove formed between the protrusions formed on the top of the relief is 0.1 to 0.9 in terms of volume ratio {groove volume on the relief / (groove depth on the relief × relief area)}. Is good. If this value is too small, it will be close to a normal relief structure, and if it is too large, most will be grooves, and the proportion occupied by the convex structure will decrease and the protrusion will become brittle. Therefore, the effect of suppressing the movement of the ink to the outside of the relief during printing cannot be expected.
FIG. 8 is a diagram showing a device for reducing the amount of ink placed on the tip of the relief toward the periphery of the relief in order to further suppress the marginal. FIG. 8A is a diagram showing a device for reducing the amount of ink accumulated here from the central portion by increasing the protrusion at the tip of the relief toward the periphery and narrowing the gap between the grooves. A method may be used in which the size of the protrusions is constant and the distance between the protrusions decreases toward the outside. Further, FIG. 8B is a diagram showing a device in which the depth of the groove formed between the protrusions is made shallower in the periphery of the relief, and the amount of ink accumulated here is reduced from the central portion.

In order to further suppress the marginal, a multilayer structure may be combined with the present invention as a plate structure.
FIG. 11 is a diagram showing a multilayer structure. (A) shows a single layer version. (B) shows a multilayer plate having a two-layer structure provided with a hardness difference. (C) shows a plate having the same configuration as (b) but with a relief tip (an angle between the relief tip and the relief side) formed at an acute angle. (D) shows a shoulder angle (angle of a base layer and a relief side surface). That is, a relief relief multilayer may be used in combination with FIG. 11B, or a relief layer and a base layer. In order to improve the uniformity of the ink film transferred from the plate, the upper part of the relief on which the ink is deposited has a low hardness (low compression modulus). However, if the hardness is low, the dot gain at the time of printing tends to increase, so the thickness of the low hardness layer needs to be optimized by a printing experiment. Conversely, if ink coverage is sufficient but the dot gain is large, the relief upper layer is set to a higher hardness than the lower layer in order to suppress the marginal more, and the stress due to printing pressure is absorbed more in the lower layer. It may be possible to cope by doing. If the hardness is too low, the printing pressure absorption effect will act excessively and the ink transfer will be reduced, so the hardness difference needs to be optimized.

As a method for suppressing the marginal, a technique in which the shoulder of the relief upper layer is acute, and FIG. In the process of creating a plate by pouring uncured resin into a mold, the relief shape of the original mold may be processed in multiple stages. Although there is a means of providing a flexible layer under the support, the printing pressure absorption effect tends to be lower than that of the above method. In order to prevent tilting of the cross-sectional shape of the relief, the relief shape close to the base is expanded like Mt. Fuji, that is, a shoulder relief, a single-layer version having a small shoulder angle as shown in FIG. Conceivable.
Next, in addition to the effect of the fine protrusions, a method for reducing the marginal by using a method in which the surface free energy of the relief top surface and the inside of the groove are different will be described.

When the relief top surface is lowered from the groove surface free energy to make it difficult for the ink to get wet on the top surface (FIG. 4), the ink is collected in the groove (FIG. 4A), and is almost absent from the top surface. When pressed against the substrate in this state, the ink inside the groove is pressed against the substrate (FIG. 4B), but since there is almost no ink on the top surface, the ink flowing out of the relief may be suppressed unless pressed with excessive printing pressure. it can. After the plate is separated from the substrate (FIG. 4 (c)), the ink is leveled as shown in FIG. 4 (d).
When the groove portion is made lower than the surface free energy of the relief top surface to make the ink difficult to wet into the groove portion (FIG. 5), the ink adheres to the top surface and hardly adheres to the inside of the groove. (FIG. 5A) When printing is performed by pressing against the substrate in this state, the ink spreads due to the pressing pressure, and excess ink enters the groove (FIG. 5B), and the flow out to the outside of the relief is suppressed. If the inside of the groove is configured to repel the ink, the ink moves to the substrate side and does not remain inside the groove when the plate is released. Therefore, repeated printing can be performed. After the plate leaves the substrate, the ink is leveled as shown in FIGS. 5 (c) and 5 (d).

Next, the arrangement of the protrusions will be described. Regarding the arrangement, it is possible to adopt a staggered arrangement (FIGS. 7A and 7B) in addition to a grid pattern (FIGS. 6A and 6B). For example, in the staggered arrangements of FIGS. 7A and 7B, the distance between the protrusions is made more uniform, so that the leveling property is improved, and the adjacent protrusions are shifted from the grid arrangement, so that the ink flows in the shifted direction. It is effective for suppression. Further, the arrangement of ink as shown in FIGS. 10C and 10D can suppress the flow of ink to the outside.
Furthermore, in the present invention, the flexographic method using a resin plate has been described as an example of the printing method, but not only typical flexographic printing but also other letterpress printing methods, for example, letterpress offset printing method letterpress plates can be similarly implemented. is there.

By suppressing marginal by the method described above, a closer pattern can be independently formed. FIG. 3 is an enlarged view for comparing the pattern reproducibility of the prior art and this embodiment. Conventionally, when patterns are brought closer to each other by marginal (Fig. 3 (a)), in this embodiment, the connection is suppressed by reducing marginal (Fig. 3 (b)), The pattern interval can be further reduced as compared with the case where the operation is not performed. As is clear from the above results, according to the present invention, the protrusion of ink to the surroundings is suppressed, and the marginal is suppressed. Therefore, it is possible to further narrow the interval between patterns.
Next, a method for forming a device with the above-described printing plate will be described by taking TFT as an example. First, a conductive pattern corresponding to a gate electrode and wiring is formed on a substrate. As the ink, a dispersion of metal fine particles, a conductive polymer, or the like can be used. Next, a pattern corresponding to the gate insulating film of the TFT is printed in accordance with a predetermined position on the formed pattern. The printing plate should be replaced with one corresponding to the insulating film pattern. After that, the version changes whenever the pattern is changed.

As the ink, a polymer resin material dissolved in a solvent or an inorganic coating material such as a polysilazane material can be used. Next, a source electrode, a drain electrode, and wiring connected to these are formed at predetermined positions. Next, a semiconductor pattern is formed so as to straddle the source and drain electrodes. As the ink, an organic semiconductor such as a polythiophene derivative or a polyacene soluble in a solvent can be used. Next, in order to protect the element, a protective film pattern is formed so as to cover these patterns. As the material, a polymer resin material or the like dissolved in a solvent can be used.
The relief printing plate of the present invention can be used for printing of functional materials such as wiring, electrodes, insulating films, sealing materials, EL light emitting materials, semiconductor materials, and color filters, including those used in the above TFTs. is there.

  The present invention is suitable for the case where fine pattern creation related to electronics, photonics, bioelectronics, etc. is performed by the relief printing method.

It is a figure which shows the printing plate. (A) A relief cross section is shown. (B) The relief tip is shown. It is a figure which shows the subject at the time of transfer and the relief printing plate used for relief printing. (A) A letterpress printing plate is shown. (B) A state where the ink is pressed against the substrate. (C) The ink transferred to the substrate. It is a figure which shows the influence on the pattern of a marginal. (A) It is a figure which shows the state in which the pattern was connected because the marginal was large. (B) It is a figure which shows the state from which the marginal was improved and the pattern was isolate | separated. It is a figure which shows the pattern formation process when the surface free energy of the top part surface is made low and an ink is repelled. (A) A state when ink is supplied to the plate. (B) A state when the plate is pressed against the substrate. (C) A state when the ink is transferred to the substrate. (D) A state when the ink is leveled on the substrate. It is a figure which shows the pattern formation process when the surface free energy inside a groove | channel is made low and an ink does not enter a groove | channel. (A) A state when ink is supplied to the plate. (B) A state where the plate is pressed against the substrate. (C) A state when the ink is transferred to the substrate. (D) A state when the ink is leveled on the substrate. It is a figure explaining that the microprotrusion which has a line part along a shape was arrange | positioned in the relief edge part. (A) The case where the arrangement direction and the direction of the relief end portion coincide is shown. (B) A case where a part of the pattern is formed by a straight line oblique to the arrangement direction and crosses the protrusion is shown. (C) A case where a part of the pattern is formed by a curve and crosses the protrusion is shown. (D) The case where the arrangement direction and the method of the relief end coincide with each other and the end of the pattern crosses the protrusion is shown. (E) A case where protrusions are arranged in a curved pattern is shown. It is a figure which shows a zigzag arrangement. (A) A staggered arrangement in the case where the protrusions are square. (B) A staggered arrangement when the protrusions are circular. (C) A state in which the ink is arranged so that it is difficult for the ink to flow outward in a pattern constituted by straight lines. (D) A state in which ink is arranged so that it is difficult for the ink to flow outward in a pattern constituted by curves. It is a figure which shows the example adjusted with the groove width or the groove depth in order to reduce the ink density of a relief periphery. (A) The case where the peripheral groove width is narrowed is shown. (B) A case where the groove depth in the peripheral portion is made shallow is shown. It is a figure which shows a printing machine. It is a figure which shows a printing process. Each figure shows a cross section. (A) A state where the ink is spread on the anilox plate of the printing press. (B) A state in which the plate is pressed onto the anilox plate on which the ink has been developed is shown. (C) shows a state in which the pattern forming ink is supplied to the tip of the relief. (D) shows a state in which the plate is pressed against the substrate. (E) shows a state where the transfer is completed by separating the plate from the substrate. (F) shows the state when the ink is leveled. It is a figure which shows a relief cross-sectional shape. (A) A single layer version is shown. (B) A two-layer structure in which the hardness difference of the multilayer plate is provided. (C) A two-layer structure with a shoulder difference of a multilayer plate is shown. (D) Show shoulder angle.

Explanation of symbols

1 Plate Base 2 Relief 3 Protrusion 4 Groove 5 Substrate (Substrate)
6 Ink 7 Marginal (ink that protrudes from the top)
8 Pattern without marginal 9 Base on which printing board of printing press is placed 10 Printed pattern 11 Anilox plate 12 Doctor blade 13 Doctor blade moving direction 14 Plate 15 Plate cylinder 16 Plate cylinder moving direction 17 Shoulder angle 18 Relief of protrusion Line part along the relief edge shape on the edge side

Claims (8)

In the printing relief plate for transferring the ink supplied on the relief of the plate to the printing medium, a plurality of protrusions are formed on the relief, and the periphery of the top of the protrusion at the relief end of the plurality of protrusions. A letterpress for printing, characterized in that the shape has a line portion along the shape of the relief end. 2. The relief printing plate according to claim 1, wherein the line portion has a straight line or a curved line. 3. The relief printing plate according to claim 1, wherein the shape of the periphery of the top of the protrusion other than the relief end is the same as or different from the protrusion of the end. Letterpress for printing. 4. The relief printing plate according to claim 1, wherein a surface free energy difference between the relief top surface and the relief groove is 5 × 10 ⁻² mJ / m ² or more. Letterpress for printing. 5. The relief printing plate according to claim 4, wherein the relief top surface repels ink and the relief groove is wetted with ink. 5. The relief printing plate according to claim 4, wherein the relief top surface is wetted with ink and the relief groove portion repels ink. 5. The relief printing plate according to claim 4, wherein the surface free energy of the relief top surface is smaller than the surface free energy of the relief groove. 5. The printing relief printing plate according to claim 4, wherein the surface free energy of the relief top surface is larger than the surface free energy of the relief groove.

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