JP2007083408A - Intaglio for reverse printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technically easily and inexpensively an intaglio having a high-precision plate depth, by formation of a recess pattern having a high aspect ratio. <P>SOLUTION: In the intaglio 20 for reverse printing which removes ink corresponding to a non-image area, from the ink applied to the whole effective printing surface of an offset blanket, recess patterns 14 and 15 corresponding to a printing image area are formed in the region of a resin film layer 12 formed on a base substrate 11 and having a thickness equal to a desired plate depth, by etching the resin film layer. A metal thin film or a metal oxide thin film 13 is formed on the surface of the resin film layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-image portion corresponding portion of an ink film applied to the entire printing effective surface of a printing blanket in an offset printing method for printing a printed matter of a high-definition image using a printing blanket for ink transfer. The present invention relates to an intaglio for reversal printing in a reversal printing method in which after the ink film is removed with an intaglio for reversal printing, ink remaining as an image line portion corresponding to the blanket surface is transferred to a printing medium and printed.

  In recent years, liquid crystal displays (LCDs) have attracted attention as flat panel displays. Due to the thin, lightweight, low power consumption, and flicker-less characteristics of LCDs, notebook personal computers (PCs) and PC monitors are mainly used. In addition, the market expanded rapidly. Recently, large LCDs have also been used for televisions (TVs) where CRT has been the mainstream.

  The liquid crystal color filter (CF) is formed by forming a colored layer of three colors, red, green, and blue, and four colors obtained by adding black to a transparent substrate. Conventionally, this colored layer is formed by processing a pigment-dispersed photosensitive photoresist by a photolithography method.

  In recent years, in order to reduce the cost of a liquid crystal color filter (CF), it has been proposed to form the liquid crystal color filter (CF) by a printing method. Conventionally, various means for printing and forming a high-definition image with high accuracy have been studied. As described above, if formation of a high-definition and high-quality image can be stably realized by a printing method, the cost can be generally reduced in a short process, and therefore there is a great expectation for image formation by a high-definition printing method.

  In the printing method, after ink is applied to the intaglio, the ink applied to the non-image area other than the depression (cell) of the intaglio is removed with a squeegee, and the ink remaining in the depression of the image area is made of rubber. There is an intaglio offset printing method (for example, refer to Patent Document 1) in which the image is transferred to a printing blanket and printed on a printing medium (a printing substrate such as a glass substrate).

  As described above, as a high-definition image forming method using a printing method, the intaglio offset printing method using an intaglio and a printing blanket, as represented by a transfer (offset) format, has been established as a promising technology. ing.

Further, as a high-definition and uniform film-forming method, a printing method called a reversal printing method has recently been developed and proposed. (For example, see Patent Document 2)
In the reverse printing method, first, ink is applied to the entire effective surface of the rubber blanket in the ink application process, and then formed into a predetermined shape on the ink application surface of the blanket in the ink removal process. Pressing a reverse printing plate (ink removing plate) having a convex or intaglio plate corresponding to the non-imaged portion on the surface in a pattern, presses the non-imaged portion or concave portion of the convex portion (top) of the plate The ink on the blanket surface is transferred to the other non-image area, and the ink on the non-image area is removed from the blanket surface. Finally, in the ink transfer process, the ink corresponding to the image area remaining as a pattern (reversal pattern) on the ink application surface of the blanket surface is transferred to a substrate (a substrate to be printed such as a glass substrate). It is a method of printing.

This reverse printing method can control the ink application and the ink transfer independently, so the uniformity of the ink film thickness to be transferred and printed is good, and the good transfer without causing the ink stringing phenomenon due to viscosity is reduced. Since it can be realized by printing pressure, it is an advantageous printing method for forming a high-definition image with little distortion.

  As a plate making form for making a reversal printing intaglio (ink removing intaglio) used in the reversal printing method, for example, a glass substrate surface for intaglio plate making with less stretchability, a glass etching solution such as hydrofluoric acid, etc. On the other hand, a metal thin film such as a hardly soluble chromium film is used as a masking material (resist film), and a masking pattern corresponding to a non-image area by the masking material is provided. And the method of forming the recessed part of the pattern equivalent to an image part in parts other than a masking pattern by etching the said board | substrate with a glass etching liquid is known.

  The pattern size of the color filter (CF) ranges from a high-definition mobile PC to a liquid crystal TV having a relatively large pixel size. As the screen becomes larger, the pattern size arranged in the color filter is also improved by the black matrix (BM) for improving contrast, the pixel pattern of R, G, B, the reference mark for alignment (register mark, From a fine line of about several μm to a large pattern of about several mm such as a frame pattern for shading. Therefore, when making the intaglio plate for reverse printing, it is necessary to make the plate so that patterns of various dimensions are arranged on the same intaglio plate.

  In the ink removal process, the non-image part (intaglio bank part) of the intaglio for reversal printing, in which the pattern of various dimensions is made as a depression (intaglio cell part) corresponding to the image line part, is printed (offset printing) The ink is transferred to the non-image area of the intaglio by pressing the ink surface applied to the printing effective surface of the blanket, and the ink corresponding to the non-image area of the blanket surface is removed.

  In this case, when the intaglio plate for reversal printing is shallow, a phenomenon that the blanket surface comes into contact with the bottom surface of the concave portion of the intaglio plate due to the nip pressure between the intaglio plate and the blanket surface is recognized. In this phenomenon, the ink in the concave portion corresponding to the image line portion is pushed out by the blanket surface, and the print reproducibility is hindered. As a measure for avoiding this phenomenon, a method in which the depth of the recess (plate depth) is set deep in a pattern having a large opening size of the recess is employed.

  The patterns currently used for color filters are a mixture of a high-definition pattern consisting of several μm to several μm, a fine line pattern of several μm to several hundred μm, and a large pattern of several mm.

  Here, the etching factor (EF) as a general formula is represented by the following formula.

E. F = 2D1 / (W2-W1) = D1 / R (1)
D1; Depth after etching W1; Opening width of masking pattern layer (exposed width of substrate to be etched)
W2; concave opening width of the substrate to be etched after etching R; concave side etch amount In a conventional plate making method by wet etching of an intaglio plate for reverse printing made of glass, a side etch amount (R; concave portion) during wet etching of glass The ratio (etching factor) of the amount of shaving in the depth direction to the amount of shaving in the side wall surface direction and the penetration width into the back surface of the masking pattern layer is about 1.

Therefore, the upper limit for forming the plate depth D1 of the concave pattern of the inversion plate for reverse printing is as follows:
E. F = 2D1 / (W2-W1) ≈1 (2)
D1 ≒ (W2 -W1) / 2
Thus, it approximates to a value half that of the value obtained by subtracting the opening width W1 of the masking pattern layer from the recess opening width W2 of the substrate to be etched after etching.

  A glass substrate for etching is obtained by using E.I. The recess opening width W2 of the substrate to be etched after etching that can be formed by a wet etching method with F≈1 has a formation limit of several μm.

  On the other hand, when the ink is transferred to the non-image area of the intaglio for reversal printing to remove the ink corresponding to the non-image area of the blanket surface, if the intaglio is shallow, In some cases, the blanket surface comes into contact with the bottom surface, and the ink in the concave portion corresponding to the image line portion is pushed out by the blanket surface, which may hinder printing reproducibility. Therefore, it is necessary to obtain a plate depth that does not touch the bottom at the minimum in the formation limit of each recess opening width W2 of several μm on the substrate to be etched after etching.

Below, the well-known patent document relevant to this invention is described.
JP 62-85202 A Japanese Patent Laid-Open No. 7-14314

  The present invention removes the ink film corresponding to the non-image area portion from the ink film applied to the entire printing effective surface of the printing blanket using the intaglio for reverse printing, and then corresponds to the image area on the blanket surface. This is an intaglio for reversal printing used in the reversal printing method, in which the ink remaining as a part is transferred to a substrate to be printed, and is used to produce high-definition images for manufacturing flat panel displays such as liquid crystal color filters with high display quality. An intaglio for reversal printing used for printing, and to provide an intaglio having a high-definition plate depth by forming a concave pattern with a high aspect ratio, technically easily and inexpensively.

  According to a first aspect of the present invention, there is provided a reverse printing intaglio that removes ink that becomes a non-image area from the ink applied to the entire printing effective surface of an offset blanket. The intaglio plate for reverse printing is characterized in that a recess pattern corresponding to a printed image line portion is formed by etching the resin film layer in a region of the resin film layer having a thickness equal to the plate depth.

  According to a second aspect of the present invention, there is provided a reverse printing intaglio that removes ink that becomes a non-image area from the ink applied to the entire printing effective surface of an offset blanket, and is formed on a base substrate. In the region of the resin film layer having a thickness equal to the plate depth, a recess pattern corresponding to the printed image portion is formed by etching the resin film layer, and the resin film layer outer surface or the outer surface and the inner surface of the recess pattern And an intaglio for reverse printing, wherein a metal thin film or a metal oxide thin film is formed.

  According to a third aspect of the present invention, in the intaglio for reversal printing according to the first or second aspect, the concave pattern of the resin film layer is an etching process having an etching factor (EF) of 1.0 or more. An intaglio for reverse printing, characterized in that it is formed.

  In the invention according to claim 4 of the present invention, in the intaglio plate for reverse printing according to any one of claims 1 to 3, an average surface unevenness difference of the 20 mm width unit surface on the surface when the resin film layer is formed is An intaglio plate for reverse printing, characterized in that it is 0.7 μm or less.

According to a fifth aspect of the present invention, in the intaglio for reversal printing according to any one of the first to fourth aspects, the base substrate and the substrate to be printed printed by the printed image line portion of the intaglio pattern; The intaglio plate for reversal printing is characterized in that the difference in thermal expansion coefficient is 15 × 10 ⁻⁷ / ° C. or less.

  According to the intaglio plate for reversal printing of the present invention, the opening width of the concave portion after plate making is an intaglio plate having a high-definition pattern consisting of several μm to several μm, a fine line pattern intaglio having a pick-up number of several μm to several hundred μm, An intaglio having a large pattern of about several millimeters, or an intaglio in which these patterns are mixed, can be made while considering the etching factor (EF).

  Further, according to the intaglio plate for reversal printing of the present invention, it is possible to make a plate on the intaglio base substrate surface made of glass or the like until the recess opening width W2 of the substrate to be etched after etching is close to the formation limit of several μm. In addition, it is possible to obtain a plate depth that does not reach the bottom at the formation limit of each recess opening width W2 of several μm on the substrate to be etched after etching.

  Therefore, by using the intaglio plate for reversal printing of the present invention, the ink applied to the entire surface of the printing effective surface of the blanket is transferred to the non-image portion (intaglio bank portion) of the intaglio, and the non-image line of the blanket surface is transferred. When the ink corresponding to the portion is removed, the blanket surface does not come into contact with the bottom surface of the concave portion of the intaglio and does not hit the bottom. Therefore, it is possible to prevent the ink in the concave portion corresponding to the image line portion from being pushed out by the blanket surface and causing trouble in the reproducibility of printing.

  As described above, according to the present invention, an intaglio for reversal printing used in the reversal printing method can be easily made, and there is an effect that a high-precision intaglio can be provided, and a liquid crystal color filter capable of displaying a high-quality image, etc. There is an effect that a high-definition print pattern can be printed on a substrate such as a glass substrate used in the flat display.

  The intaglio for reversal printing of the present invention is an intaglio for removing ink that becomes a non-image area from the ink applied to the entire printing effective surface of the offset blanket, and will be described in detail below.

  An intaglio for reversal printing according to claim 1 of the present invention is an intaglio for reversal printing that removes ink that becomes a non-image area from ink applied to the entire printing effective surface of an offset blanket, and a base substrate. A concave pattern corresponding to the print image line portion is formed in the region of the resin film layer having a thickness equal to the desired plate depth formed above.

  As shown in the side end view of FIG. 1, in the inversion plate 20 for reversal printing according to the present invention, a resin film layer 12 having a film thickness D0 is formed on a base substrate 11. A concave portion 14 (and a concave portion 15 of the frame pattern as necessary) of the image pattern having a depth D1 (plate depth) reaching the surface of the base substrate 11 substantially corresponding to the printed image portion is formed. The region of the resin film layer 12 other than the concave patterns 14 and 15 is a bank portion 16 having a flat surface. In this case, the plate depth D1 is a value equal to the film thickness D0 of the resin film layer 12 or a value approximate to the film thickness D0.

Moreover, as the intaglio plate 20 for reversal printing of the present invention, as shown in FIG. 1, a masking material layer for obtaining the printing pressure strength of the intaglio plate 20 for reversal printing is provided on the outer surface of the resin film layer 12. The metal thin film layer or metal oxide thin film layer 13 (with the photosensitive photoresist film removed from the surface) may be coated. In this case, the plate depth D1 is equal to the total film thickness D0 of the resin film layer 12 and the film thickness to of the metal thin film layer 13 (or metal oxide thin film layer) 13, or approximates the total film thickness. Value.

  FIGS. 2A to 2C are schematic diagrams for explaining the printing process of the reverse printing method using the intaglio plate 20 for reverse printing according to the present invention. First, as shown in FIG. 2 (a), an offset printing blanket having a printing ink peelable surface (for example, silicone rubber) on the peripheral surface of an offset printing blanket cylinder 21 that can be driven and rotated by a reversing printing machine. 22 is wound and fixed, and printing ink 23 is applied to the entire printing effective surface of the blanket 22.

  Subsequently, as shown in FIG. 2 (a), the surface of the offset printing blanket 22 wound around the offset printing blanket cylinder 21 is brought into contact with the surface of the bank portion 16 of the reverse printing intaglio 20 while a predetermined mark is applied. Roll by applying pressure (nip pressure).

  Due to the contact rolling of the offset printing blanket cylinder 21, the printing ink 23 applied to the blanket 22 is removed from the surface of the bank portion 16 of the inversion printing intaglio 20 as shown in FIG. 2B. Transition as 25. On the other hand, the printing ink 23 applied to the surface of the blanket 22 corresponding to the concave patterns 14 and 15 of the inversion printing intaglio 20 remains as the reverse printing image ink 25 on the surface of the blanket 22.

  Subsequently, the peripheral surface of the offset printing blanket cylinder 21 in which the reverse printing image ink 25 remains on the surface of the blanket 22 is applied with a predetermined printing pressure while being brought into contact with the surface of the substrate 26 (printing substrate). Move. As a result, the reverse printing image ink 25 remaining on the surface of the blanket 22 is transferred, and a reverse printing image is printed on the surface of the printing medium 26.

  As a method for forming the concave patterns 14 and 15 on the resin film layer 12 of the intaglio plate 20 for reversal printing according to the present invention, a method by dry etching can be used. As a method of forming the concave pattern 14 by this dry etching process, a resist film made of a metal thin film or an inorganic oxide thin film on the resin film layer 12 on the base substrate 11, and a photosensitive photoresist film formed on the resist film The masking material 13 consisting of the above is patterned in a portion other than the recess opening for etching. Thereafter, the recess opening where the surface of the resin film layer 12 where the masking material 13 is not formed is exposed is formed by etching.

  Then, after patterning the resist film and the photosensitive photoresist film to expose the resin film layer in a pattern, dry etching is performed until the resin film layer in the pattern exposed part reaches the base substrate surface. It is formed by processing. By forming the resin film layer at a film pressure equal to the intaglio plate depth of the concave pattern, the base substrate acts as an etching stopper layer in the dry etching process, and the plate depth grade can be easily controlled.

  As the base substrate, a glass plate or a metal plate that is less stretchable with respect to environmental conditions such as temperature and humidity can be used, and as the resin layer film, a thermosetting material that provides adhesion to the base substrate can be used. A polyimide resin, an epoxy resin, an acrylic resin, a novolac resin, or the like can be used. Moreover, it is also possible to use what was formed into a film, such as a polyethylene terephthalate (PET) resin and an epoxy acrylate resin, through a thermosetting adhesive.

  As the masking material, a chromium film, an aluminum film, a transparent conductive film (ITO) that is a metal oxide film, a silicon oxide film that is an inorganic oxide film, or the like can be used.

As a film forming method for forming a masking material on the resin film layer, a vapor deposition method, a sputtering method, or the like can be used. A sputtering method having high adhesion to the resin film layer is suitable. The thickness of the masking material is preferably 2000 mm or more from the viewpoint of masking performance and film stress.

  As a method for forming an opening of a mask pattern for a masking material formed on a resin film layer, a photosensitive photoresist film is applied and formed on the masking material, and then a photosensitive photoresist film is formed by photolithography. The mask pattern is exposed and developed to remove the portion of the photosensitive photoresist film corresponding to the mask pattern opening to expose the masking material.

  Thereafter, the exposed portion of the resin film layer is wet-etched with an etchant (such as an organic solvent that dissolves the resin film) that can etch the resin film, or an etching gas that can etch the resin film is introduced. By performing a dry etching process, a concave pattern reaching the base substrate surface is formed in the resin film layer. The masking material (photoresist film, masking film made of a metal thin film or inorganic oxide thin film, or the masking film and the photoresist film) remaining on the resin film layer after forming the recess pattern is peeled and removed as necessary. Can do.

As a dry etching treatment method for the resin film layer, there are a TCP method, an RIE method, and the like. As a gas to be introduced as an etching gas, a mixed gas system of oxygen (O ₂ ) gas and argon (Ar) gas, fluoride gas, etc. It is possible to use a hydrogen-based reactive gas.

  An intaglio for reversal printing according to a second aspect of the present invention is an intaglio for reversal printing that removes ink that becomes a non-image area from the ink applied to the entire printing effective surface of an offset blanket. A metal thin film or metal oxide is formed on the outer surface, or the outer surface and the inner surface of the concave pattern corresponding to the printed image portion formed in the region of the resin film layer having a thickness equal to the desired plate depth formed in A physical thin film is formed.

  The intaglio for reversal printing used in the reversal printing method is used by pressing the blanket surface of the printing press against the intaglio surface at a high printing pressure, so that the intaglio can withstand the printing pressure. Printing durability is required.

  The resin film layer in the intaglio plate for reversal printing of the present invention has a higher hardness than the blanket material (rubber with a flexible surface) and good printing durability, but the resin film layer surface on which the recess pattern is formed By forming a metal thin film or a metal oxide thin film in the concave portion of the concave pattern or / and on the bank portion of the concave pattern, the physical strength of the resin film layer on which the concave pattern is formed can be increased. .

  As a method of forming a metal thin film or a metal oxide thin film in the concave portion of the resin film layer on which the concave pattern is formed or / and on the bank portion of the concave pattern, the resin film layer is formed on the resin film layer on which the concave pattern is formed. There are a method of forming the entire surface by sputtering, a method of leaving the metal thin film or the metal oxide thin film as a masking material remaining on the resin film layer of the concave pattern after the etching process without peeling off, and the like.

  An intaglio for reverse printing according to a third aspect of the present invention is the above intaglio for reverse printing, wherein the concave pattern of the resin film layer is formed by an etching process having an etching factor (EF) of 1.0 or more. It is what has been.

  Table 1 below shows the relationship between the opening size of the concave portion of the high-definition concave portion pattern as the printed image portion and the printable plate depth in the intaglio plate for reverse printing of the present invention.

  The etching factor (EF) as a general formula is expressed by the following formula.

E. F = 2D / (W2−W1) = D / R (1)
D: Plate depth of the resin film layer after etching W1; Opening width (dimensions) of masking material at the concave portion corresponding to the concave pattern
W2: Recess opening width (dimensions) of the recess pattern of the resin film layer after etching
R: Amount of concave side etching The aspect ratio (AS) is expressed by the following formula.

        AS = D / W2 (3)

凹部パターンの解像性を決定するＥ．Ｆ量は、前述の如く一般的なガラス基板のウエットエッチング処理では、１である。表１に示すように、Ｅ．Ｆ＝１にて形成できる凹部パターンの凹部開口幅（寸法）は１８μｍ以上であり、それ以下の開口寸法の形成は不可能である。

E. Determining the resolution of the concave pattern As described above, the F amount is 1 in the general wet etching process of a glass substrate. As shown in Table 1, E.I. The recess opening width (dimension) of the recess pattern that can be formed at F = 1 is 18 μm or more, and it is impossible to form an opening dimension smaller than that.

  In addition, when there are concave patterns with different opening dimensions on the same substrate, the plate depth in the concave pattern with the widest opening dimension (width) is processed so that the plate depth required for printing reproducibility is obtained. Therefore, it is necessary to form a concave pattern having a narrow opening size (width) so as to have a plate depth necessary for printing reproducibility.

  In the concave pattern etching of the resin film layer in the intaglio for reversal printing of the present invention, the etching process of the resin film layer on the base substrate is performed by the dry etching process method. Processing with an F amount of 1 or more is possible, and a concave pattern with an opening size of 18 μm or less can be formed.

  In the case where a concave pattern having an opening dimension of the concave pattern of 18 μm or more is formed, E.I. Although it is possible to cope with the F amount of 1, the side etch amount is large, which causes a decrease in the resolution of the formed concave pattern.

  In the concave pattern etching of the resin film layer in the intaglio plate for reverse printing of the present invention, as described above, E.E. Depending on the resin material used for the resin film layer, E.F. Processing with an F amount of 8 or more can be performed, the side etch amount R can be suppressed, and a concave pattern with high resolution can be obtained.

  An intaglio for reversal printing according to a fourth aspect of the present invention is the surface smoothness of the resin film layer formed on the base substrate of the inversion plate for reversal printing, on the surface when the resin film layer is formed. The average surface unevenness difference of the 20 mm width unit surface is 0.7 μm or less.

  The unevenness and waviness on the surface of the resin film layer when making an intaglio plate for reversal printing is caused by variations in the opening width (dimension, opening line width) of the recess formed in the resin film layer during plate making, It tends to cause transfer failure. The required value for the finest control of the variation in the opening width of the recesses formed in the resin film layer is ± 1 μm.

Considering the case where the variation of the opening width of the concave pattern formed in this resin film layer is ± 1 μm and the amplitude of the irregularities and undulations on the surface of the resin film layer is 0.5 μm, the surface of the resin film layer The continuous irregularities and undulations in the image have a tendency to be transferred to the surface of the printing medium during reverse printing, and adversely affect the reproducibility and quality of printing. Therefore, it has been found that the unevenness of the surface of the resin film layer and the amplitude of waviness when making an intaglio for reverse printing must be suppressed to less than 0.5 μm.

  In addition, when using a glass plate as the base substrate of an intaglio for reverse printing, the material manufacturer guarantees the smoothness of the glass material is that the surface irregularity of the 20 mm surface width is 0.1 μm or less, and the resin film layer at that time is As for the smoothness of the surface of the resin film layer in application control during application formation, surface irregularities with a surface width of 20 mm are 0.7 μm or less, and desirably, specifications equivalent to those guaranteed by the material manufacturer are required.

  As a method for forming the resin film layer, a die coater or a curtain coater can be used. By using a die coater, the film thickness can be controlled to 0.05 μm or less in the width direction of the coater, and in-plane unevenness and undulation can be suppressed by controlling the drive of the die coater. Furthermore, techniques such as chemical polishing and physical polishing can be used as a technique for increasing smoothness.

According to a fifth aspect of the present invention, in the intaglio for reversal printing, a difference in thermal expansion coefficient between the base substrate and a substrate to be printed printed by a printed image line portion of the intaglio pattern is 15 × 10 ^{−. 7} / ° C or less.

  For example, in a color filter substrate (for example, a transparent glass substrate or a transparent plastic substrate) for a liquid crystal display device, in order to guarantee the positional accuracy of a display cell with a counter electrode substrate (for example, a transparent glass substrate or a transparent plastic substrate) facing the color filter substrate. In addition, it is required to control the variation of the total pitch of the filter substrate to ± 3 μm or less. Currently, the color filter substrate and the counter electrode substrate are made of glass materials with the same coefficient of thermal expansion, and exposure is also performed using a quartz photomask with a low coefficient of thermal expansion to stabilize the expansion and contraction of the substrate and control the total pitch. Is going.

  Further, the required expansion / contraction accuracy of the base substrate in the intaglio printing for reversal printing used in the reversal printing method is required to have the same thermal expansion coefficient as that of the substrate used for the exposure mask of the photolithographic method. For example, when a transparent glass substrate or a transparent plastic substrate is used for the exposure mask of the photolithography method, it is appropriate to use a transparent glass substrate or a transparent plastic substrate as the base substrate of the intaglio for reverse printing, respectively. That is, the control of the total pitch of the intaglio for reversal printing is related to the control of the total pitch of the color filter substrate and is important.

  For example, in the intaglio plate making for reversal printing, if processing is performed through an exposure mask during the photolithographic processing in forming a concave pattern, the photolithographic processing accuracy decreases to an accuracy equal to or lower than the accuracy of the exposure mask. It is also possible to draw a concave pattern by exposure with a drawing exposure machine.

As a method for controlling the total pitch in the intaglio plate for reverse printing, it is desirable to use a material having a thermal expansion coefficient close to that of the glass substrate or plastic substrate used for the color filter substrate for the base substrate of the intaglio plate for reverse printing. At present, the thermal expansion coefficient of the glass substrate used for the liquid crystal color filter is about 30 × 10 ⁻⁷ / ° C. For example, the glass substrate has a substrate size of 1000 mm, and the length changes by 3 μm when the temperature of 1 ° C. changes. .

In order to guarantee the required specification of ± 3 μm for the liquid crystal display, the difference in total pitch between the base plate of the plate making and the color filter substrate must be controlled within ± 1.5 μm, and the difference in thermal expansion coefficient is 15 × 10 ⁻⁷ / ° C. or less is desirable. The substrate whose thermal expansion coefficient approximates that of a color filter substrate may be selected from low-expansion glass and low-expansion metal materials used in liquid crystal displays.

  Also, during the dry etching process of the resin film layer applied and formed on the base substrate, due to the generation of heat when the etching process descends, fluctuations in the total pitch of the recess pattern etched in the resin film layer after cooling and distortion of the recess pattern Therefore, during the dry etching process, it is desirable to cool the base substrate by a method such as introduction of He gas to the chuck portion for mounting and fixing the base substrate on the surface of the base substrate.

                                                                        Below, the specific Example of the intaglio for reverse printing of this invention is described.

<Example 1>
FIGS. 3A to 3E are schematic diagrams for explaining the plate making process of the inversion plate for reverse printing according to the present invention. In the intaglio plate for reverse printing 20 shown in FIG. An example of plate making when the concave pattern 15 which is a frame pattern is arranged on the same base substrate 11 at the same plate depth is shown.

  For example, the reverse printing intaglio 20 is finished with a line width of 12 μm of the concave portion 14 of the fine line image pattern, a line width of 40 μm of the concave portion 15 of the frame pattern, and a line width of the concave portion (not shown) of the alignment pattern (mark). The thickness was 40 μm and the processing plate depth was 25 μm. In addition, the exposure mask used for plate making has the above-mentioned pattern width (dimension) and the masking material and resin film layer E.I. F amount was added as a correction value.

First, as shown in FIG. 3A, as a base substrate 11 of an intaglio for reverse printing, low expansion glass (size 620 mm × 750 mm, thickness 0.7 mm, Corning Corporation 1737, glass thermal expansion coefficient: 3.8 × 10 ^-6 / ° C) was prepared.

  Next, as shown in FIG. 3A, after a thermosetting synthetic resin (for example, epoxy acrylate resin) is applied to one side of the base substrate 11 by a coating machine 31 (for example, a die coater), The resin film layer 12 having a thickness of 25 μm was formed by heat curing.

  Next, as shown in FIG. 3B, a pure chromium (Cr) film is formed on the entire surface of the resin film layer 12 by a sputtering method, and a masking material layer 13 (chrome film layer) having a thickness of 2000 mm is formed. Then, a photosensitive photoresist solution was applied to the entire surface of the masking material layer 13 at a thickness of 1 μm to form a photoresist layer 17.

  Thereafter, as shown in FIG. 3C, pattern exposure is performed by a photolithography method using an exposure mask in which a mask pattern corresponding to a concave pattern is formed on the surface of the photoresist layer 17 by an exposure machine. The resist opening portion 18 corresponding to the concave portion pattern where the masking material layer 13 is exposed and exposed is formed in a pattern in the photoresist layer 17.

  Next, as shown in FIG. 3D, the masking material layer 13 exposed in the resist opening 18 of the photoresist layer 17 is wet-etched with a chromium etching solution made of cerium ammonium sulfate, and the masking is performed. A masking opening 19 (chrome film layer opening) in which the resin film layer 12 having the same pattern as that of the resist opening 18 corresponding to the recess pattern is exposed is formed in the material layer 13.

Next, as shown in FIG. 3E, oxygen gas (O ₂ ) is introduced as a reactive gas by a dry etching apparatus (RIE method). At F = 5, the resin film layer 12 exposed at the resist opening 18 and the masking opening 19 is dry-etched, and the resin film layer 12 is formed by a fine printed image pattern recess 14 and a frame pattern recess 15. A pattern was formed, and the intaglio 20 for reverse printing of the present invention was made. The photoresist layer 17 on the masking material layer 13 was peeled and removed by a dry etching process when forming the concave pattern of the resin film layer 12.

<Result>
In the intaglio plate 20 for reverse printing of the present invention thus obtained, the depth (plate depth) of the concave pattern of the concave portions 14 and 15 is 25 μm, and the variation in the plane of the opening width (dimension) of the concave portion is ± 1. 0.0 μm, variation in total pitch could be controlled at ± 2.0 μm.

  In the present invention, the "in-plane variation in the opening width (dimension) of the recess" means that a dimensional error (expansion / contraction) of the recess pattern (image line portion) formation region on the entire surface of the intaglio 20 for reverse printing (or the base substrate). The variation in the total pitch "means a finished dimensional error between alignment marks (registration marks, registration marks) formed opposite to both ends of the intaglio 20 for reversal printing by exposure of the exposure mask. (Stretch value).

Further, using the intaglio plate 20 for reversal printing of the present invention, reversal printing is performed on a low expansion glass substrate (550 mm × 650 mm, thickness 0.7 mm, Corning 1737, glass thermal expansion coefficient: 3 × 10 ⁻⁶ / ° C.). The color pattern printed by this method could be controlled with a variation in pattern dimension of ± 1.2 μm and a variation in total pitch of ± 2 μm. Further, the bottom of the blanket during printing on the bottom of the recesses 14 and 15 did not occur.

<Example 2>
FIGS. 4A to 4E are schematic diagrams for explaining the plate making process of the inversion plate for reverse printing according to the present invention. In the intaglio plate for reverse printing 20 shown in FIG. 1, the concave pattern 14 which is an image pattern of fine lines. An example of plate making when the concave pattern 15 which is a frame pattern is arranged on the same base substrate 11 at the same plate depth is shown.

  For example, the intaglio plate 20 for reverse printing has a line width of 80 μm of the concave portion 14 of the fine line image pattern, a line width of 80 μm of the concave portion 15 of the frame pattern, and a line width of the concave portion (not shown) of the alignment pattern (mark). The depth was 40 μm and the processing plate depth was 30 μm. In addition, the exposure mask used for plate making has the above-mentioned pattern width (dimension) and the masking material and resin film layer E.I. F amount was added as a correction value.

First, as shown in FIG. 4A, a low expansion glass (size: 620 mm × 750 mm, thickness: 0.7 mm, Corning Corporation 1737, glass thermal expansion coefficient: 3 × 10) is used as the base substrate 11 of the intaglio for reverse printing. ^-6 / ° C).

  Next, as shown in FIG. 4A, after a thermosetting synthetic resin (for example, epoxy acrylate resin) is applied to one side of the base substrate 11 by a coating machine 31 (for example, a die coater), The resin film layer 12 having a thickness of 30 μm was formed by heat curing.

  Next, as shown in FIG. 4B, an ITO film is formed on the entire surface of the resin film layer 12 by a sputtering method to form a masking material layer 13 (ITO film) having a thickness of 2000 mm, Subsequently, a photoresist layer 17 was formed on the entire surface of the masking material layer 13 by applying a photosensitive photoresist solution at a thickness of 1 μm.

Thereafter, as shown in FIG. 4C, pattern exposure is performed by a photolithography method using an exposure mask in which a mask pattern corresponding to a concave pattern is formed on the surface of the photoresist layer 17 by an exposure machine. The resist opening portion 18 corresponding to the concave portion pattern where the masking material layer 13 is exposed and exposed is formed in a pattern in the photoresist layer 17.

Next, as shown in FIG. 4D, chlorine gas (Cl ₂ ) is introduced as a reactive gas by a dry etching apparatus (RIE method), and masking exposed to the resist opening 18 of the photoresist layer 17. The material layer 13 is subjected to a dry etching process, and a masking opening 19 (chrome film layer opening) in which the resin film layer 12 having the same pattern as the resist opening 18 corresponding to the recess pattern is exposed is formed in the masking material layer 13. Formed.

Next, as shown in FIG. 4E, oxygen gas (O ₂ ) is introduced as a reactive gas by a dry etching apparatus (RIE method). At F = 5, the resin film layer 12 exposed at the resist opening 18 and the masking opening 19 is dry-etched, and the resin film layer 12 is formed by a fine printed image pattern recess 14 and a frame pattern recess 15. A pattern was formed, and the intaglio 20 for reverse printing of the present invention was made. During this dry etching process, helium gas (He) was introduced from the back surface of the base substrate 11 to cool the substrate, and the temperature of the base substrate 11 was controlled to be kept at 14 ° C. or lower. The photoresist layer 17 on the masking material layer 13 was peeled and removed by a dry etching process when forming the concave pattern of the resin film layer 12.

<Result>
In the intaglio plate 20 for reverse printing of the present invention thus obtained, the depth (plate depth) of the recess pattern of the recesses 14 and 15 is 30 μm, and the variation in the plane of the opening width (dimension) of the recess is ± 1. 0.0 μm, variation in total pitch could be controlled at ± 2.0 μm.

Moreover, using the intaglio plate 20 for reversal printing of the present invention, a low expansion glass substrate (550 mm × 650 mm, thickness 0.7 mm, Corning 1737, glass thermal expansion coefficient: 3.8 × 10 ⁻⁶ / ° C.) The color pattern printed by the reversal printing method could be controlled with an in-plane variation of pattern size of ± 1.2 μm and a variation in total pitch of ± 2 μm. Further, the bottom of the blanket during printing on the bottom of the recesses 14 and 15 did not occur.

The outline side sectional view of the intaglio for reverse printing of the present invention. (A)-(c) is a schematic explanatory drawing explaining the printing process of the reverse printing method using the intaglio for reverse printing of this invention. (A)-(e) is a general | schematic side sectional view explaining one Example of the plate-making process of the intaglio for reverse printing of this invention. (A)-(e) is a schematic sectional side view explaining the other Example of the plate-making process of the intaglio for reverse printing of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Base board | substrate 12 ... Resin film layer 13 ... Masking material layer 14 ... Concave part (printing image part equivalent part)
15: Concave part (corresponding part to print image part)
DESCRIPTION OF SYMBOLS 16 ... Bank part 17 ... Photoresist layer 18 ... Resist opening part 19 ... Masking opening part 20 ... Intaglio for reverse printing 21 ... Blanket cylinder 22 of printing press ... Blanket 23 ... Printing ink 24 ... Removal ink 25 ... Transfer ink (image line) Ink)
26 ... Substrate to be printed (printed substrate made of glass)
31 ... Resin film coating machine

Claims (5)

  A resin film layer having a thickness equal to a desired plate depth formed on a base substrate in an intaglio for reversal printing that removes ink that becomes a non-image area from ink applied to the entire printing effective surface of an offset blanket. An intaglio plate for reverse printing, wherein a recess pattern corresponding to a print image line portion is formed in the region of the substrate by etching the resin film layer.   A resin film layer having a thickness equal to a desired plate depth formed on a base substrate in an intaglio for reversal printing that removes ink that becomes a non-image area from ink applied to the entire printing effective surface of an offset blanket. In this region, a recess pattern corresponding to the printed image portion is formed by etching the resin film layer, and a metal thin film or a metal oxide thin film is formed on the outer surface or the outer surface and the inner surface of the resin film layer of the recess pattern. An intaglio for reversal printing, characterized in that   3. The reverse printing intaglio according to claim 1, wherein the concave pattern of the resin film layer is formed by an etching process having an etching factor (EF) of 1.0 or more. intaglio.   The reversal printing intaglio according to any one of claims 1 to 3, wherein an average surface unevenness difference of a 20 mm width unit surface on the surface when the resin film layer is formed is 0.7 μm or less. Intaglio for printing. 5. The intaglio plate for reversal printing according to claim 1, wherein a difference in thermal expansion coefficient between the base substrate and a substrate to be printed by a printed image line portion of the intaglio pattern is 15 × 10 ^−5. An intaglio for reverse printing, characterized in that it is ⁷ / ° C or less.

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