Printing plate and printing method

Abstract

To provide a printing plate that can apply paint evenly.SOLUTION: The printing plate 1 according to one aspect of the present invention has a printing opening 31 corresponding to the printing region, and, in a portion of the inner edge of one side in a first direction of the printing opening 31 and extending in a second direction that is approximately orthogonal to the first direction, a plurality of degassing protrusions 32 protruding in the first direction toward the inside of the printing opening 31 and having a width that decreases toward the tip thereof.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a printing plate and a printing method. [Background technology]

[0002] A technique for forming a printed circuit is known in which a paint made of a resist composition is screen-printed on the surface of a metal layer laminated on a substrate or the like, and the metal layer is selectively removed by etching using the print pattern of the paint as a mask to form electrical wiring or the like. In particular, when forming fine circuits or the like, it is desirable to prevent print bleeding (the paint flowing out of the area corresponding to the openings of the printing plate). For example, Patent Document 1 describes that the surface of the printing plate that comes into contact with the printed material B is formed from a water-repellent material in order to prevent print bleeding when using a water-based paint. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-156439 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the quality of printed circuits, it is desirable to prevent not only bleeding of the print but also fading of the print (the formation of areas in the area of ​​the printing plate where the amount of paint applied is insufficient). If the edge of the printing plate's opening on the downstream side in the squeegee movement direction is a straight line parallel to the tip edge of the squeegee, air bubbles are likely to be left behind in the opening along this edge, forming areas where the amount of paint applied is insufficient. Therefore, an object of the present invention is to provide a printing plate and a printing method that can apply paint evenly. [Means for solving the problem]

[0005] A printing plate according to one embodiment of the present invention has a printing opening corresponding to a printing area, and has a plurality of deaeration protrusions at a portion of an inner edge on one side of a first direction of the printing opening extending in a second direction approximately perpendicular to the first direction, the protrusions protruding in the first direction toward the inside of the printing opening and decreasing in width toward their tips.

[0006] In the printing plate according to one aspect of the invention, the protrusion length of the deaeration projections is preferably 70 μm or more.

[0007] In the printing plate according to one aspect of the invention, the width of the base end of the deaeration projection is preferably 10 μm or more and 100 μm or less.

[0008] In the printing plate according to one aspect of the present invention, the multiple deaeration projections are preferably formed at intervals of 100 μm or more and 1000 μm or less.

[0009] A printing method according to one embodiment of the present invention involves placing the above-mentioned printing plate on the surface of a substrate and moving a squeegee along the printing plate from the other side to one side in the first direction to push paint into the printing opening. Effect of the Invention

[0010] According to the present invention, the paint can be applied uniformly. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic plan view showing a portion of a printing plate according to one embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view of the printing plate of FIG. 1 taken along line AA. [Diagram 3] 2 is a vertical cross-sectional view illustrating printing using the printing plate of FIG. 1. [Figure 4] 2 is a planar cross-sectional view illustrating printing using the printing plate of FIG. 1. [Diagram 5] 1 is a graph showing the relationship between the length of deaeration projections and the fill factor in prototype examples of printing plates. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, each embodiment of the present invention will be described with reference to the attached drawings. Note that the same or equivalent parts in each drawing will be given the same reference numerals. For simplification, illustrations and reference numerals of members may be omitted, in which case other drawings shall be referred to.

[0013] Fig. 1 is a schematic plan view showing a part of a printing plate 1 according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of printing plate 1 taken along line AA. Fig. 3 is a vertical cross-sectional view illustrating printing using printing plate 1. Fig. 4 is a plan cross-sectional view illustrating printing using printing plate 1.

[0014] Printing plate 1 is a printing stencil that is placed on the surface of a substrate B and selectively passes paint P pressed by a squeegee S moving in a first direction along the surface of printing plate 1. Printing plate 1 according to this embodiment is intended to be used for printing paint P made of a resist composition onto the surface of a metal layer laminated on a substrate, and forming a conductive pattern by etching using this resist composition as a mask.

[0015] The printing plate 1 can be configured to include a mesh (gauze) 2 that exists across the front surface, and an emulsion 3 that is supported by this mesh 2. In other words, the printing plate 1 is a printing plate for screen printing.

[0016] The mesh 2 has fine openings over the entire surface through which the paint P can pass. The mesh 2 can be made of a cloth-like or mesh-like material such as plain weave, twill weave, or tatami weave. As a specific example, the mesh 2 can be made of a wire mesh or the like as specified in JIS-G3555 (2003). The mesh number of the mesh 2 can be, for example, 200 to 500.

[0017] The emulsion 3 has a certain thickness and is formed so as to protrude from the mesh 2 towards the printing substrate B. The thickness of the emulsion determines the thickness of the paint P to be printed. Therefore, the amount by which the emulsion 3 protrudes from the mesh 2 is determined according to the film thickness of the paint P to be printed, and can be, for example, 20 μm or more and 50 μm or less. When forming a coating film with a relatively large film thickness, uneven printing due to air bubbles is likely to become a problem, and the advantages of the printing plate 1 having the characteristics described below become apparent.

[0018] Furthermore, the emulsion 3 has printing openings 31 which correspond to the printing areas and through which the paint P passes. The emulsion 3 can be formed, for example, by forming a layer of uncured photocurable resin having a certain thickness and into which the mesh 2 is immersed, and selectively irradiating the photocurable resin with light in this state.

[0019] The emulsion 3 has a number of deaeration protrusions 32 on a portion of the inner edge on one side in the first direction of the printing aperture 31 (the lower side in the up-down direction in Fig. 1) that extends generally parallel to a second direction (the left-right direction in Fig. 1) that is generally perpendicular to the first direction, in other words, on a portion of the inner edge on the downstream side in the movement direction of the squeegee S that extends in the extension direction of the tip edge of the squeegee S. Each deaeration protrusion 32 protrudes towards the other side in the first direction (the upstream side in the movement direction of the squeegee S) towards the inside of the printing aperture 31, and is formed so that its width in the first direction decreases towards its tip.

[0020] The multiple deaeration protrusions 32 are disposed at intervals from one another. The deaeration protrusions 32 prevent the paint P pushed in by the squeegee S during printing from closing the squeegee S side (upper side) of the printing opening 31 and trapping air on the printed material B side (lower side). Note that "substantially perpendicular" means forming an angle of 70° to 110°, preferably 80° to 100°.

[0021] 3, the leading edge of the paint P pushed in by the squeegee S is located further downstream in the direction of movement of the squeegee S inside the printing aperture 31, the higher it is. For this reason, when the paint P pushed in by the squeegee S simultaneously reaches an area of ​​the inner edge on the downstream side of the printing aperture 31 that has a certain length or more, air bubbles are left behind along the inner edge on the downstream side of the printing aperture 31, making it impossible to completely fill the paint P.

[0022] In contrast, in the printing plate 1, the paint P pushed in by the squeegee S first comes into contact with the tip of the deaeration protrusion 32. At this point, a path for the air to escape remains on the downstream side, so no air bubbles are left behind on the upstream side of the deaeration protrusion 32. As shown in FIG. 4, the deaeration protrusion 32 suppresses the downstream movement speed of the paint P pushed downstream along its side surface. This makes it possible to prevent the tip edge of the paint P from simultaneously reaching the inner edge on the downstream side of the printing aperture 31. For this reason, the air in the printing aperture 31 can be pushed out to the outside by the paint P without leaving any air bubbles, so that the printing aperture 31 can be filled with the paint P without leaving any air bubbles.

[0023] In order to reliably suppress the speed of the paint P along the side surface of the deaeration protrusion 32 in plan view, it is preferable to form the deaeration protrusion 32 in a trapezoidal shape with a base that is an imaginary line extending from the inner edge of the printing opening 31. In addition, by decreasing the width of the deaeration protrusion 32 toward the tip, the part where the deaeration protrusion 32 was located can be filled with paint P without leaving any air bubbles due to bleeding of the paint P after printing. The planar shape of the deaeration protrusion 32 may be a triangular shape, etc., but if the tip of the deaeration protrusion 32 is made too sharp, it may be insufficient in strength or difficult to form, so it is preferable that the deaeration protrusion 32 has a certain width even at the tip. In addition, the planar shape of the deaeration protrusion 32 may be a shape in which the rate of decrease in width changes depending on the position in the first direction, such as a spindle shape.

[0024] The lower limit of the protruding length of the deaeration projection 32 is preferably 70 μm, more preferably 90 μm, and even more preferably 100 μm. On the other hand, the upper limit of the protruding length of the deaeration projection 32 is preferably 1000 μm, more preferably 800 μm, and even more preferably 500 μm. By setting the protruding length of the deaeration projection 32 to the lower limit or more, it is possible to reliably prevent the paint P from simultaneously reaching the inner edge on the downstream side of the printing aperture 31. On the other hand, if the protruding length of the deaeration projection 32 is too small, it is not possible to obtain the arrival time difference of the paint P necessary to completely discharge the air from the printing aperture 31, and there is a risk that air bubbles will remain and cause smearing of the coating film. In addition, by setting the protruding length of the deaeration projection 32 to the upper limit or more, it is possible to prevent the volume of the deaeration projection 32 from becoming too large, and the part where the deaeration projection 32 was located can be filled with the paint P due to the bleeding of the paint P after printing.

[0025] The lower limit of the width of the deaeration protrusion 32 at its base end is preferably 10 μm, and more preferably 20 μm. On the other hand, the upper limit of the width of the deaeration protrusion 32 at its base end is preferably 100 μm, and more preferably 80 μm. By setting the width of the deaeration protrusion 32 at its base end to be equal to or greater than the above-mentioned lower limit, a sufficient protruding length of the deaeration protrusion 32 can be ensured. Furthermore, by setting the width of the deaeration protrusion 32 at its base end to be equal to or less than the above-mentioned upper limit, the area where the deaeration protrusion 32 was located can be filled with paint P due to bleeding of the paint P after printing.

[0026] The lower limit of the spacing between the deaeration protrusions 32 (the gap at the base end) is preferably 100 μm, and more preferably 300 μm. Meanwhile, the lower limit of the spacing between the deaeration protrusions 32 is preferably 1000 μm, and more preferably 800 μm. By setting the spacing between the deaeration protrusions 32 to be equal to or greater than the lower limit, a sufficient amount of paint P can be secured to fill in the areas where the deaeration protrusions 32 were located after printing. Furthermore, by setting the spacing between the deaeration protrusions 32 to be equal to or less than the upper limit, the time at which the paint P reaches the inner edge on the downstream side of the printing aperture 31 can be sufficiently shifted, thereby preventing air bubbles from being left behind in the printing aperture 31.

[0027] As described above, the printing plate 1 can prevent air bubbles from being left behind in the printing openings 31 by the deaeration protrusions 32, so that areas where the paint is insufficient (air bubbles or recesses formed when air bubbles connect to the surface) are not formed in the coating film. Therefore, by printing an etching resist composition using the printing plate 1, an etching mask that enables precise etching can be formed.

[0028] In a printing method according to one embodiment of the present invention, with printing plate 1 placed on the surface of print substrate B, a squeegee S is moved from the other side to one side in the first direction along printing plate 1 to push paint P into printing aperture 31. As is clear from the description of printing plate 1, the printing method according to this embodiment can prevent air bubbles from being left behind in printing aperture 31, so that paint P can be applied evenly to the desired printing area. EXAMPLES

[0029] The present invention will be specifically described below based on examples, but the present invention is not limited to the following examples.

[0030] The wiring of the solar cell was formed by screen printing the resist composition using the printing plate prototypes 1 to 7 in which trapezoidal deaeration protrusions were formed on the inner edge of the printing aperture downstream in the squeegee movement direction on the metal layer formed by sputtering and plating, and etching using the printed resist composition as a mask. The main wiring was in a direction extending parallel to the tip edge of the squeegee. The lengths of the deaeration protrusions of the printing plate prototypes 1 to 7 were 0 μm to 180 μm in 30 μm increments. In all prototypes 1 to 7, the width of the base end of the deaeration protrusion was 30 μm, the width of the tip of the deaeration protrusion was 10 μm, and the spacing between the deaeration protrusions was 500 μm. The fill factor (FF: the value obtained by dividing the output at the optimal operating point by the product of the open circuit voltage and the short circuit current) of these prototypes was measured and used as a criterion for the suitability of printing the resist composition.

[0031] Figure 5 is a graph showing the relationship between the length of the deaeration protrusions and the fill factor for printing plate prototypes 1 to 7. As the graph shows, by setting the height of the deaeration protrusions to a certain value or more, it was possible to prevent air bubbles from being left behind in the printing apertures during printing, form the electrode pattern accurately, and obtain a good fill factor.

[0032] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and various changes and modifications are possible. For example, the printing plate according to the present invention may be a printing stencil such as a metal mask without a mesh.

[0033] The coating material printed using the printing plate of the present invention is not limited to a resist composition, but may be, for example, a conductive paste, a solder paste, an insulating agent, or the like.

[0034] The printing plate according to the present invention may include protrusions of a different shape or arrangement from the deaeration protrusions. In other words, the printing plate according to the present invention does not require that all of the protruding structures provided on the inner edge have the characteristics of the deaeration protrusions. Also, the deaeration protrusions need only be provided on the part of the inner edge of the printing aperture that is parallel to the tip edge of the squeegee on the downstream side in the squeegee movement direction, but similar protrusions may be provided on other parts of the inner edge of the printing aperture. [Explanation of symbols]

[0035] 1 Print version 2 Mesh 3 Milk wood 31 Printing Aperture 32 Deaeration protrusion B Printing material P paint S squeegee

Claims

1. a printing aperture corresponding to the printing area; a plurality of deaeration projections are provided at a portion of an inner edge of the printing aperture on one side in a first direction, the portion extending in a second direction substantially perpendicular to the first direction, the deaeration projections protruding in the first direction toward the inside of the printing aperture and decreasing in width toward the tip of the projections; The printing plate has a protruding length of the deaeration projections of 70 μm or more.

2. a printing aperture corresponding to the printing area; a plurality of deaeration projections are provided at a portion of an inner edge of the printing aperture on one side in a first direction, the portion extending in a second direction substantially perpendicular to the first direction, the deaeration projections protruding in the first direction toward the inside of the printing aperture and decreasing in width toward the tip of the projections; The printing plate, wherein the plurality of deaeration projections are formed at intervals of 100 μm or more and 1000 μm or less.

3. 3. The printing plate according to claim 1, wherein the width of the base end of the deaeration projection is from 10 μm to 100 μm.

4. A printing method comprising the steps of: placing a printing plate according to any one of claims 1 to 3 on a surface of a substrate; and moving a squeegee along the printing plate from the other side to the one side in the first direction to push paint into the printing apertures.

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