JP2007152560A - Intagliated plate for offset printing and offset printing method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intagliated plate for offset printing, with which the conductive paste of an electrode material can be printed in certain width and thickness with high positional accuracy. <P>SOLUTION: Ink made of conductive paste 6 is filled in the recesses of the intagliated plate 1 and, after that, the ink is transferred from the intagliated plate 1 to a blanket cylinder 8 and finally the ink transferred on the blanket cylinder 8 is re-transferred onto a substrate 9. The intagliated plate is formed by covering a flat plate 2 made of a material having nearly the same thermal expansion coefficient as that of the substrate 9 with the resin 3 so as to form the recesses on the resin 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intaglio for offset printing and an offset printing method using the same, and more specifically, for example, an intaglio for offset printing used for forming electrodes on a glass substrate for PDP (plasma display panel) and the like. The present invention relates to an offset printing method using.

  In a gas discharge panel such as a PDP, electrodes are formed on a glass substrate. The electrode is formed by a thin film method or a thick film method. In the thin film method, generally, a thin film of a conductive material is formed on the entire glass substrate by vapor deposition or the like, and an electrode is formed by etching this to remove unnecessary portions. In the thick film method, an electrode is formed by printing a conductive paste as an electrode material on a glass substrate and firing it.

  When printing a conductive paste on a glass substrate by the above thick film method, offset printing may be used because it is simple and highly accurate. In this offset printing, an intaglio plate for offset printing is used, and the concave portion of the intaglio plate is filled with ink made of a conductive paste, and the ink is once transferred from the intaglio plate to a blanket cylinder called a rubber cylinder. Printing is performed by retransferring the upper ink to the substrate.

  Substrates used for the intaglio for offset printing include, for example, glass substrates such as soda lime glass, non-alkali glass, quartz glass, low alkali glass, low expansion glass, fluorine resin, polycarbonate (PC), polyethersulfone. Resin plates such as (PES), polyester, and polymethacrylic resin, and metal substrates such as stainless steel, copper, nickel, and low expansion alloy amber can be used (see Patent Document 1). Thus, as the intaglio for offset printing, a substrate made of a single material such as a glass substrate, a metal substrate, or a resin substrate is used.

JP 2003-151350 A

  By the way, in a gas discharge panel such as a PDP, high positional accuracy is required for the formation of electrodes as the screen becomes higher in definition. Therefore, high printing accuracy is required even in offset printing.

  However, when using a metal substrate as an intaglio for offset printing, there is a difference between the coefficient of thermal expansion of the intaglio and the coefficient of thermal expansion of the panel substrate (usually glass) to which the conductive paste is transferred, so the printing accuracy is reduced, Without strict temperature control, it is difficult to maintain a certain printing accuracy.

  In addition, when a metal substrate is used as the intaglio, the recess is usually formed by etching, but when the recess is formed by etching, the width and depth of the recess should be formed with a certain size in the electrode width of the PDP. Is difficult, and the shape of the recess becomes unstable. For this reason, variations occur in the width and thickness of electrodes printed by offset printing.

When a glass substrate or a low expansion alloy amber is used as an intaglio for offset printing, the thermal expansion coefficient of the intaglio and the thermal expansion coefficient of the panel substrate are almost the same, so there is no decrease in printing accuracy. Therefore, as in the metal substrate described above, the width and thickness of the printed electrodes vary.
Even when a resin substrate is used as an intaglio for offset printing, the printing accuracy is lowered due to the difference in thermal expansion coefficient.

  The present invention has been made in consideration of such circumstances, and a substrate (for example, glass) having the same thermal expansion coefficient as the panel substrate is used as an intaglio for offset printing, and a recess is formed on the surface thereof with a resin. Thus, the conductive paste of the electrode material can be printed with a certain width and thickness and with high positional accuracy.

  The present invention is an intaglio for offset printing, in which a concave portion of the intaglio is filled with ink made of a conductive paste, the ink is transferred from the intaglio to a blanket cylinder, and the transferred ink on the blanket cylinder is applied to a substrate. The intaglio is used when retransferring, and the intaglio is obtained by coating a resin on a flat plate made of a material having a thermal expansion coefficient substantially the same as that of the substrate, and forming the recess in the resin. This is an intaglio for offset printing.

  According to the present invention, since there is no difference between the thermal expansion coefficient of the intaglio for offset printing and the thermal expansion coefficient of the substrate, good printing accuracy can be maintained. In addition, since the concave portion is formed in the resin portion of the intaglio, if the concave portion is formed by, for example, a photolithography method, the concave portion can be formed with a certain width and depth. Can be printed with a width and thickness of.

  The intaglio for offset printing of the present invention is used for offset printing, and in the offset printing, the intaglio of the present invention is filled with ink made of a conductive paste, and the ink is once blanketed from the intaglio. The ink transferred onto the (rubber cylinder) is transferred again to the substrate.

  In the present invention, any substrate may be used as long as it can be used for a display panel. Examples of the substrate include substrates such as glass, quartz, and ceramics.

  In the present invention, the intaglio plate is a plate in which a resin is coated on a flat plate produced using a material having a thermal expansion coefficient substantially equal to that of the substrate, and a recess is formed in the resin. For this reason, when glass is applied to the substrate, it is desirable that the intaglio is a resin in which a resin is formed on a flat plate made of the same material as the glass and a recess is formed in the resin. Examples of the flat plate used for the intaglio include glass substrates such as soda lime glass, non-alkali glass, quartz glass, low alkali glass, and low expansion glass, as well as fluororesin, polycarbonate (PC), and polyethersulfone (PES). Resin plates such as polyester and polymethacrylic resin, and metal substrates such as stainless steel, copper, nickel, and low expansion alloy amber can be used.

  As the resin coated on the intaglio plate, fluororesin, polycarbonate (PC), polyethersulfone (PES), polyester, polymethacrylic resin and the like can be applied. Of these, the resin preferably has water repellency, and in this sense, it preferably contains a fluororesin.

  The resin desirably contains a photosensitive material. By including a photosensitive material in the resin, the concave portion can be formed by a photolithographic technique, whereby the width and depth of the concave portion can be formed with high accuracy.

  The present invention is also an offset printing method using the intaglio for offset printing, and has a convex portion corresponding to a non-concave portion of the intaglio after filling the concave portion of the intaglio with ink made of a conductive paste. This is an offset printing method comprising a step of cleaning the resin surface of the intaglio with a cleaning relief plate.

  In the above printing method, it is desirable that the cleaning relief printing plate is composed of a cleaning roll in which convex portions are formed on the surface of the roller.

  Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. In addition, this invention is not limited by this, A various deformation | transformation is possible.

  1 (a) and 1 (b) are explanatory views showing the structure of a PDP in which electrodes are formed by offset printing using the intaglio of the present invention. FIG. 1A is an overall view of the PDP, and FIG. 1B is a partially exploded perspective view of the PDP. This PDP is an AC drive type three-electrode surface discharge type PDP for color display.

  The PDP 10 includes a front substrate 11 and a rear substrate 21 on which components that function as a PDP are formed. As the front substrate 11 and the rear substrate 21, a glass substrate, a quartz substrate, a ceramic substrate, or the like can be used.

On the inner surface of the front substrate 11, display electrodes X and display electrodes Y are arranged at equal intervals in the horizontal direction. The display line L is entirely between the adjacent display electrode X and display electrode Y. Each display electrode X, Y is composed of a wide transparent electrode 12 such as ITO or SnO ₂ and a narrow bus electrode 13 made of metal such as Ag or Au. For the display electrodes X and Y, the transparent electrode 12 is formed by depositing ITO, SnO ₂ or the like by vapor deposition or sputtering, and the bus electrode 13 is fired by offset printing of Ag, Au or the like. Thus, the desired number, thickness, width and interval are formed.

  In this PDP, the display electrode X and the display electrode Y are arranged at equal intervals, and a PDP having a structure in which the display line L is entirely between the adjacent display electrodes X and Y is shown. However, the present invention is not limited to this. The present invention can also be applied to a PDP having a structure in which the pair of display electrodes X and Y are arranged with an interval (non-discharge gap) at which no discharge occurs.

  On the display electrodes X and Y, a dielectric layer 17 for alternating current (AC) driving is formed so as to cover the display electrodes X and Y.

  A protective film 18 is formed on the dielectric layer 17 to protect the dielectric layer 17 from damage caused by ion collision caused by discharge during display. This protective film is made of MgO. The protective film can be formed by a thin film forming process known in the art, such as an electron beam evaporation method or a sputtering method.

  On the inner side surface of the substrate 21 on the back side, a plurality of address electrodes A are formed in a direction intersecting the display electrodes X and Y in plan view, and a dielectric layer 24 is formed to cover the address electrodes A. . The address electrode A generates an address discharge for selecting a light emitting cell at the intersection with the Y electrode. The address electrode A is also offset-printed with Ag, Au, etc., like the display electrodes X and Y. Then, the desired number, thickness, width and interval are formed by firing. A dielectric layer 24 is formed on the address electrode A so as to cover the address electrode A.

  A plurality of stripe-shaped partition walls 29 are formed on the dielectric layer 24 between the adjacent address electrodes A and A. The shape of the barrier ribs 29 is not limited to this, and may be a mesh shape (box shape) that partitions the discharge space for each cell. The partition walls 29 can be formed by a sand blast method, a printing method, a photo etching method, or the like. For example, in the sandblasting method, a glass paste made of a low melting point glass frit, a binder resin, a solvent, etc. is applied on the dielectric layer 24 and dried, and then a cutting mask having an opening of a partition pattern is formed on the glass paste layer. It forms by spraying cutting particle | grains in the provided state, cutting the glass paste layer exposed to the opening of a mask, and also baking. In the photo-etching method, instead of cutting with cutting particles, a photosensitive resin is used as the binder resin, and it is formed by baking after exposure and development using a mask.

  Red (R), green (G), and blue (B) phosphor layers 28R, 28G, and 28B are formed on the side surfaces of the partition walls 29 and on the dielectric layer 24 between the partition walls. For the phosphor layers 28R, 28G, and 28B, a phosphor paste containing phosphor powder, a binder resin, and a solvent is applied to the concave discharge space between the barrier ribs 29 by screen printing or a method using a dispenser. This is repeated for each color and then fired. The phosphor layers 28R, 28G, and 28B can be formed by a photolithography technique using a sheet-like phosphor layer material (so-called green sheet) containing phosphor powder, a photosensitive material, and a binder resin. In this case, a phosphor sheet of each color can be formed between the corresponding partition walls by applying a sheet of a desired color to the entire display area on the substrate, exposing and developing, and repeating this for each color. it can.

  In the PDP, the front-side substrate 11 and the rear-side substrate 21 on which such components are formed are arranged so that the display electrodes X and Y and the address electrodes A intersect, and the periphery is sealed, It is manufactured by filling the discharge space 30 surrounded by the partition walls 29 with a discharge gas in which Xe and Ne are mixed. In this PDP, the discharge space 30 at the intersection of the display electrodes X and Y and the address electrode A is one cell (unit light emitting region) which is the minimum unit of display. One pixel is composed of three cells, R, G, and B.

  The bus electrodes 13 and the address electrodes A of the display electrodes X and Y described above are formed by printing an electrode pattern of a conductive paste by offset printing, drying it, and firing it. Specifically, for the bus electrode 13, after forming the transparent electrode 12 on the substrate 11 on the front side, alignment is performed on the transparent electrode 12, and ink made of a conductive paste such as Au or Ag is applied. It forms by transferring by offset printing, drying this, and baking. The address electrode A is formed by aligning the substrate 21 on the back side, transferring a conductive paste such as Au or Ag by offset printing, drying it, and baking it.

FIG. 2 is an explanatory view showing a side surface of the intaglio used for offset printing.
The intaglio 1 for offset printing according to the present invention includes a flat plate 2 and a resin 3 formed on the flat plate 2. A recess 3 a is formed in the resin 3.

  As the material of the flat plate 2, a substrate having the same thermal expansion coefficient as the substrate to be transferred, that is, the substrate on which the conductive paste is printed is used. For example, in the case of forming a PDP electrode, a soda-lime glass or a high strain point glass such as PD-200 (manufactured by Asahi Glass Co., Ltd.) is generally used as the PDP substrate. A flat plate 2 made of the same glass is used. However, as described above, the flat plate 2 only needs to have the same thermal expansion coefficient as that of the transfer substrate, and is not necessarily made of the same material. A resin 3 is formed on the flat plate 2, and a recess 3 a corresponding to the electrode pattern to be formed is formed on the resin 3.

  The resin 3 is formed by laminating the dry film on the surface of the flat plate 2 using a photosensitive dry film resist (hereinafter simply referred to as “dry film”) known in the art. Examples of the dry film that can be used include NIT-600 series manufactured by Nippon Synthetic Chemical Industry Co., Ltd.

  The thickness of the laminate matches the depth of the recess 3a to be formed. For example, when the NIT-600 series is used when the concave portion 3a having a depth of 50 μm is to be formed, NIT-625 having a thickness of 25 μm is laminated twice. Then, the resin 3 composed of the dry film layers laminated in this manner is patterned using a photolithographic technique known in the art, and a recess 3 a corresponding to the electrode pattern is formed in the resin 3. After this patterning, if necessary, the resin 3 is cured by heat or light, whereby the intaglio 1 is produced.

  In addition to this, the resin 3 may be formed by applying a liquid or paste resist in a predetermined thickness and drying it. In this case, the patterning method is the same as that when a dry film is used.

  In offset printing, the recess 3a of the intaglio 1 is filled with ink made of a conductive paste, the ink is once transferred from the intaglio 1 to a blanket cylinder (rubber cylinder), and the transferred conductive paste on the blanket cylinder is used as a substrate. Printing is performed by re-transferring to.

  By using the photosensitive resin 3 as the formation portion of the concave portion 3a, the concave portion 3a can be formed by a photolithographic technique, and the width and depth of the concave portion 3a can be uniformly formed with high accuracy.

  When the concave portion 3a is reversely tapered during patterning of the resin 3, that is, when the vicinity of the entrance / exit is narrower than the bottom of the concave portion 3a, the conductive paste filled in the concave portion 3a is difficult to come out of the concave portion 3a. Therefore, in this case, before forming the resin 3 on the flat plate 2, if necessary, a mask pattern corresponding to the electrode pattern is formed on the surface of the flat plate 2, and the resin 3 is formed thereon. The resin 3 is exposed from the back side of the flat plate 2. Thereby, the recessed part 3a can be made into the shape of a forward taper shape, ie, the shape where the entrance / exit vicinity becomes wider than the bottom part of the recessed part 3a.

  In this way, by using the flat plate 2 having the same thermal expansion coefficient as that of the transfer substrate, the resin 3 is formed on the flat plate 2 by laminating a dry film, and the concave portion 3a is formed in the resin 3, whereby the thermal expansion coefficient and The intaglio 1 satisfying the shape stability at the same time can be produced.

  For example, a resin material containing a fluorine element is applied to the resin 3 so that the surface of the resin 3 has water repellency. This facilitates removal of the conductive paste residue adhering to the surface of the resin 3. That is, when filling the recess 3a of the intaglio 1 with the conductive paste, scraping the residue of the conductive paste on the surface of the resin 3 with the blade while filling the recess 3a with the conductive paste by squeezing with the blade. At this time, by making the resin 3 water repellent, the residue of the conductive paste hardly remains on the surface of the resin 3. Further, since the residue can be removed by weak scraping, the durability of the intaglio 1 can be improved. Moreover, the mold release property of the resin 3 is also improved.

  In the above description, a material having water repellency is added to the resin 3. However, the surface of the resin 3 may have water repellency by performing a surface treatment. In this case, since the transfer of the conductive paste from the intaglio 1 to the blanket cylinder may not be 100%, there is no problem even if the bottom surface of the recess 3a, that is, the flat plate 2, is not water-repellent.

FIG. 3 is an explanatory view showing a letterpress for cleaning.
The letterpress for cleaning 5 removes the residue of the conductive paste (unnecessary conductive paste) on the surface of the resin 3 of the intaglio 1. The cleaning relief plate 5 is formed with a cavity 5a at a position not corresponding to the recess 3a so that the conductive paste 6 filled in the recess 3a is not removed.

  The cleaning relief printing plate 5 is manufactured using a material having higher wettability than the resin 3, that is, a material having lower water repellency than the resin 3. Silicone rubber or the like is applicable as the material for the cleaning relief plate 5.

  The conductive paste 6 is filled into the concave portion 3a of the intaglio 1 by squeezing with a blade. During this squeezing, the conductive paste on the surface of the resin 3 is almost scraped off with a blade, but if the scraping is insufficient, the conductive paste remains on the surface of the resin 3. Therefore, the residue of the conductive paste is removed by the cleaning relief plate 5. Thereafter, the conductive paste 6 in the recess 3a is transferred to the blanket cylinder, and the conductive paste 6 is transferred from the blanket cylinder to the transfer substrate. Thereby, it is possible to form a clean electrode pattern without unnecessary electrode adhesion.

  In this way, by using the cleaning relief plate 5, even if a residue of the conductive paste adheres to the surface of the intaglio plate 1, the residue is removed by the cleaning relief plate 5, so that the conductive paste can be formed in a clean pattern. It becomes possible to print.

FIG. 4A to FIG. 4C are explanatory views showing the offset printing method of the present invention.
In performing offset printing, the cleaning relief plate 5 and the blanket 7 are mounted on the cylinder 8. The body 8 is rotated in the direction of arrow R. The intaglio 1 and the transferred substrate 9 are placed on the transport device 31 and moved in the direction of the arrow S.

  At the time of offset printing, the intaglio 1 is filled with the conductive paste 6. This filling is performed by squeezing with a blade. Next, as shown in FIG. 4A, the residue of the conductive paste 6 is removed with the relief relief plate 5.

  Thereafter, as shown in FIG. 4B, the conductive paste 6 is once transferred to the blanket 7 attached to the roller 8. Next, as shown in FIG. 4C, offset printing is performed by transferring the conductive paste 6 from the blanket 7 to the transfer substrate 9 again. In FIG. 4, for the sake of convenience, the directions of the grooves of the intaglio and the cleaning relief are rotated 90 degrees.

  As described above, according to the present embodiment, a high transfer accuracy can be maintained by using a substrate having the same coefficient of thermal expansion as the substrate to be transferred as the intaglio substrate. Further, by forming the recesses using a photosensitive resin, the width and depth of the recesses can be uniformly controlled.

  In addition, by adding fluorine to the intaglio resin, the surface of the intaglio can be given water repellency, which makes it difficult for the conductive paste to remain on the surface of the intaglio and removes surface residues by simple scraping. can do.

  Furthermore, since the residue on the surface of the intaglio is removed by the relief relief, unnecessary electrodes formed between the electrode patterns can be eliminated.

It is explanatory drawing which shows the structure of PDP which formed the electrode by offset printing using the intaglio of this invention. It is explanatory drawing which shows the side of the intaglio used for offset printing. It is explanatory drawing which shows the relief printing plate. It is explanatory drawing which shows the offset printing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intaglio 2 Flat plate 3 Resin 3a Recess 5 Cleaning relief 5a Cavity 6 Conductive paste 7 Blanket 8 Cylinder 9 Transfer substrate 10 PDP
DESCRIPTION OF SYMBOLS 11 Front side board | substrate 12 Transparent electrode 13 Bus electrode 17, 24 Dielectric layer 18 Protective film 21 Back side board | substrate 28R, 28G, 28B Phosphor layer 29 Bulkhead 30 Discharge space 31 Conveying device A Address electrode L Display line X, Y Display electrode

Claims (5)

An intaglio for offset printing, in which a concave portion of the intaglio is filled with an ink made of a conductive paste, the ink is transferred from the intaglio to a blanket cylinder, and the transferred ink on the blanket cylinder is retransferred to a substrate Used for
For intaglio printing, wherein the intaglio has a resin coated on a flat plate made of a material having substantially the same thermal expansion coefficient as the substrate, and the recess is formed in the resin. Intaglio.   2. The intaglio for offset printing according to claim 1, wherein the resin has water repellency.   The intaglio plate for offset printing according to claim 1, wherein the resin contains a photosensitive material, and the concave portion is formed by a photolithographic technique. An offset printing method using the intaglio for offset printing according to any one of claims 1 to 3,
An offset printing method comprising: a step of cleaning a resin surface of an intaglio with a cleaning relief having a protrusion corresponding to a non-recess of the intaglio after filling a recess of the intaglio with an ink made of a conductive paste.   The offset printing method according to claim 4, wherein the cleaning relief plate comprises a cleaning roll having the convex portions formed on a roller surface.