Screen printing plate, and method for manufacturing screen printing plate

Abstract

To provide a screen printing plate which is capable of printing ink even thinner, has stable quality and is hard to be broken or deformed, and can suppress cost increase, and a method for manufacturing a screen printing plate.SOLUTION: A screen printing plate 1 comprises: a mesh part 10 having a plurality of through holes 11; a printing pattern part 20 which is formed of a synthetic resin so as to protrude from a surface of matter to be printed side of the mesh part 10, and has a pattern hole 21 corresponding to a printing pattern; and an ink adjusting part 30 which is formed of a synthetic resin inside the pattern holes 21, and has an ink holes 31 open smaller than the pattern hole 21, where an adjustment film surface 32 on matter to be printed side of the ink adjusting part 30 is provided so as to be positioned closer to a squeegee side than a pattern film surface 22 of the printing pattern part 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a screen printing plate used for screen printing and a method for manufacturing the screen printing plate.

Background Art

[0002] As a screen printing plate used for screen printing, for example, as shown in FIG. 8(a), a screen printing plate 100 including a mesh member 101 (screen mesh) woven with wire rods and a pattern defining layer 102 fixed to the mesh member 101 has been proposed (see, for example, Patent Document 1). In this screen printing plate 100, an opening 102a corresponding to a printing pattern to be printed penetrates through the pattern defining layer 102, and the ink in the opening 102a (the portion surrounded by the two-dot chain line in the figure) is transferred (applied) to the object to be printed, thereby printing a desired printing pattern.

[0003] Screen printing using a screen printing plate has features such as being able to obtain a relatively thick printing coating film, being able to use inks with various functions, and having a relatively unrestricted type of object to be printed, and is used in various fields. For example, in the field of electronic components, screen printing is used for forming energized portions of electronic circuits, preventing short circuits of energized portions, protection during plating or etching, and the like.

[0004] As for the formation of the energized part of an electronic circuit, for example, screen printing is used when forming the internal electrodes of a multilayer ceramic capacitor (MLCC). Specifically, a conductive paste is used as ink and printed on the object to be printed (dielectric) by screen printing and dried to form a thick internal electrode. When using a screen printing plate as shown in Patent Document 1, an internal electrode with a thickness of several μm can be formed. In this MLCC, a plurality of dielectrics and internal electrodes are stacked, and the larger the number of layers, the larger the capacitance. For this reason, in order to increase the capacitance of the MLCC, there is a demand to make the internal electrode thinner and multi-layered.

[0005] In response to the above demands, by using a thinner screen printing plate, it is possible to form an internal electrode with a thickness of about 1 μm. This screen printing plate uses, for example, a screen mesh that is woven using a wire with a smaller diameter than the wire used for a conventional screen mesh and then thinly rolled (calendered) by a rolling roller. However, in this case, there is a problem that it is necessary to weave a wire with a small diameter, and the screen mesh becomes expensive.

[0006] Therefore, by using an ink in which a conductive paste is diluted with a solvent to lower the solid content concentration for a conventional screen printing plate 100, it is possible to form an internal electrode with a thinner thickness after drying compared to a conductive paste with a normal concentration. However, in this case, when the solid content concentration is lowered, the viscosity of the ink decreases, so there is a problem that so-called "bleeding", where the ink oozes out from the shape of the printed pattern, is likely to occur when printing.

[0007] On the one hand, as shown in FIG. 8(b), there has been proposed a screen printing plate 200 including a mesh portion 201 having a plurality of holes 201a and a graphic portion 202 provided on the surface side of the mesh portion 201 on the side of the object to be printed (for example, Patent Document 2). The screen printing plate 200 can be made thinner than the screen printing plate according to the technique of Patent Document 1, where the mesh portion 201 and the graphic portion 202 are formed by electroforming (electroforming). In the graphic portion 202 of this screen printing plate 200, recesses 202a corresponding to the printing pattern to be printed are formed, and the ink in the recesses 202a (the portion surrounded by the two-dot chain line in the figure) is transferred (applied) to the object to be printed, thereby printing the desired printing pattern. Therefore, according to the technique of Patent Document 2, it is possible to form a thinner internal electrode.

[0008] However, in the technique of Patent Document 2, since the screen printing plate 200 is formed by electroforming (electroplating), compared with the screen printing plate 100 having a screen mesh woven with wire materials as in Patent Document 1, there are problems that it is easily damaged and is easily deformed when stress is applied. Also, in the technique of Patent Document 2, when the area of the screen printing plate becomes large, the quality is likely to become unstable, such as the thickness becoming uneven, and it is difficult to manufacture a screen printing plate of the desired quality. For these reasons, in the conventional technique, there was a limit even when trying to form a thinner internal electrode.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] Therefore, in view of the above circumstances, the present invention aims to provide a screen printing plate that can print ink with a thinner thickness, has stable quality, is less likely to be damaged or deformed, and can suppress an increase in cost, and a method for manufacturing the screen printing plate.

Means for Solving the Problems

[0011] In order to solve the above problems, the screen printing plate according to the present invention comprises: “a mesh part formed of metal or synthetic resin and having a plurality of through holes; a printing pattern part formed of synthetic resin so that the surface on the printed material side in the mesh part is embedded, and having pattern holes corresponding to the printing pattern; an ink adjustment part formed of synthetic resin inside the pattern holes and having at least one ink hole that opens smaller than the pattern holes; wherein the surface on the printed material side in the ink adjustment part is located closer to the squeegee side than the surface on the printed material side in the printing pattern part.” It is characterized by this.

[0012] The screen printing plate of this configuration is used in a state where the surface on the object to be printed side is facing down and it is placed above the object to be printed. When screen printing, first, ink is supplied to the squeegee surface on the squeegee side of the screen printing plate, and the squeegee is moved so that the screen printing plate does not contact the object to be printed, and the ink is coated on the squeegee surface side of the screen printing plate. At this time, the ink on the squeegee surface side passes through the ink holes of the ink adjustment part and is held in the space surrounded by the inner surface of the pattern hole and the surface on the object to be printed side in the ink adjustment part. Then, when the squeegee is moved in the printing direction so that the screen printing plate contacts the object to be printed, the screen printing plate is pressed against the object to be printed by the squeegee, and the ink held in the above space is transferred to the object to be printed, and a printed pattern having the same shape as the pattern hole is printed. The thickness of the printed ink is the same as the distance between the surface on the object to be printed side in the printed pattern part and the surface on the object to be printed side in the ink adjustment part, and is thinner than the thickness of the screen printing plate. Therefore, according to the screen printing plate of this configuration, compared with the conventional screen printing plate such as Patent Document 1 in which the ink is printed with the same thickness as the screen printing plate, the ink can be printed with a thinner thickness.

[0013] Also, according to the screen printing plate of this configuration, as described above, since the thickness of the ink to be printed is determined by the distance between the surface on the object to be printed side in the printed pattern part and the surface on the object to be printed side in the ink adjustment part, it is not necessary to reduce the thickness of the entire screen printing plate as in the conventional case. Therefore, it is not necessary to consider reducing the thickness of the mesh part, and a screen mesh used for a normal screen printing plate can be used as the mesh part. As a result, even if the area of the screen printing plate is increased as in the conventional case, the quality such as uneven thickness does not become unstable, the quality of the screen printing plate can be stabilized, and an increase in the cost of the screen printing plate can be suppressed. In addition, by using a strong one as the mesh part, a screen printing plate that is difficult to be damaged or deformed can be obtained.

[0014] In addition to the above configuration, the screen printing plate according to the present invention "The ink adjusting part has a surface on the side of the object to be printed formed in a concavo-convex shape." This may be a feature.

[0015] According to this configuration, since the surface on the side of the object to be printed in the ink adjusting part is formed in a concavo-convex shape, ink can also be held in the concave parts of the concavo-convexities. As a result, when the screen printing plate is pressed against the object to be printed by a squeegee, the ink held in the concave parts is also pushed out to the side of the object to be printed, so that the ink transferred to the object to be printed can be supplemented, and it is difficult for streaks or pinholes to occur in the printed pattern.

[0016] Further, a method for manufacturing a screen printing plate according to the present invention "includes forming a first layer in which a surface on the side of the object to be printed in the mesh part is embedded, and which is a part on the squeegee side rather than the surface on the side of the object to be printed of the ink adjusting part in the printing pattern part, and a part corresponding to the pattern hole becomes the ink adjusting part, and forming a second layer on the side of the object to be printed in the formed first layer, which is the remaining part of the printing pattern part and has the pattern hole." This is a feature.

[0017] This is a method for manufacturing a screen printing plate for manufacturing the above screen printing plate. Thereby, a screen printing plate provided with an ink adjusting part having ink holes inside the pattern holes of the printing pattern part can be manufactured.

Effects of the Invention

[0018] As described above, according to the present invention, it is possible to print ink with a thinner thickness, and it is possible to provide a screen printing plate with stable quality, difficult to be damaged or deformed, and capable of suppressing an increase in cost, and a method for manufacturing a screen printing plate.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0020] Hereinafter, a screen printing plate which is a specific embodiment of the present invention and a method for manufacturing the same will be described with reference to the drawings. First, the screen printing plate 1 according to the first embodiment will be described in detail with reference to FIG. 1.

[0021] The screen printing plate 1 includes a mesh portion 10 having a plurality of through holes 11, a printing pattern portion 20 held by the mesh portion 10 and having pattern holes 21 corresponding to a printing pattern, and an ink adjusting portion 30 provided inside the pattern holes 21 and having at least one ink hole 31.

[0022] The mesh portion 10 is formed by weaving wire rods 12 made of metal or synthetic resin as warp and weft. The through holes 11 are gaps (weave) between the warp and the weft. Hereinafter, when the mesh portion 10 is horizontal, the plane in contact with the uppermost end of the mesh portion 10 will be referred to as the "squeegee side surface of the mesh portion 10", and the plane in contact with the lowermost end of the mesh portion 10 will be referred to as the "surface on the printed material side of the mesh portion 10" for explanation.

[0023] The printing pattern portion 20 is formed of synthetic resin so that the surface on the printed material side of the mesh portion 10 is embedded. The pattern holes 21 penetrate the printing pattern portion 20. In the printing pattern portion 20 of the present embodiment, the distance between the surface on the printed material side (referred to as the "pattern film surface 22") and the surface on the printed material side of the mesh portion 10 is constant. The pattern film surface 22 is a smooth planar shape. Thereby, the adhesion to the printed material can be enhanced and the blurring of the printing pattern can be reduced. Note that the pattern film surface 22 may have fine irregularities, for example, within a range that does not increase blurring, and it becomes possible to reduce the adhesion of the printed material during screen printing.

[0024] Further, in the printing pattern portion 20, the squeegee-side surface is positioned on the squeegee side of the surface on the object-to-be-printed side in the mesh portion 10. That is, since a part of the mesh portion 10 is embedded in the printing pattern portion 20, the printing pattern portion 20 is supported by the mesh portion 10.

[0025] The ink adjustment portion 30 is supported by both the mesh portion 10 and the printing pattern portion 20. The surface on the object-to-be-printed side of the ink adjustment portion 30 (referred to as the "adjustment film surface 32") is positioned on the object-to-be-printed side of the surface on the object-to-be-printed side in the mesh portion 10 and is also positioned on the squeegee side of the pattern film surface 22 of the printing pattern portion 20. In the ink adjustment portion 30 of the present embodiment, the adjustment film surface 32 is a smooth flat surface.

[0026] The ink holes 31 of the ink adjustment portion 30 open smaller than the openings of the pattern holes 21, and a plurality of ink holes 31 are provided for each pattern hole 21. The plurality of ink holes 31 are arranged at a predetermined interval (see FIGS. 3(a) and (b)). The shape of the ink holes 31 can be circular, polygonal including triangles and quadrilaterals, etc. This ink adjustment portion 30 is formed of a synthetic resin.

[0027] In the screen printing plate 1 of the present embodiment, an ink holding recess 23 (a portion surrounded by a two-dot chain line in FIG. 1), which is the internal space of the pattern hole 21 of the printing pattern portion 20, is formed on the object-to-be-printed side of the adjustment film surface 32 in the ink adjustment portion 30.

[0028] Next, the manufacturing method of the screen printing plate 1 will be described in detail with reference to FIG. 2. First, a first emulsion 2 made of a photosensitive resin is applied to the mesh portion 10 and dried. At this time, the first emulsion 2 is applied to the mesh portion 10 so that the surface of the mesh portion 10 on the side of the object to be printed is buried in the first emulsion 2 to a thickness. Then, an ink hole mask 3 for forming an ink hole 31 is disposed on the surface of the dried first emulsion 2 on the side of the object to be printed (see FIG. 2(a)). The ink hole mask 3 is provided with a light-shielding portion 3a that does not allow light to pass through at a portion where the ink hole 31 is to be formed. Note that as the ink hole mask 3, it may be one in which the light-shielding portion 3a is also provided at a portion outside the ink adjustment portion 30, that is, the light-shielding portion 3a is provided on the entire surface of the ink hole mask 3, or a portion that will become the ink hole 31 may be provided over the entire first layer 4 described later.

[0029] In the present embodiment, before disposing the ink hole mask 3, a smoothing process for smoothing the surface of the first emulsion 2 on the side of the object to be printed is performed. As the smoothing process, for example, before drying the first emulsion 2 applied to the mesh portion 10, a sheet or a plate-like member is attached to the surface on the side of the object to be printed so that no air bubbles enter the first emulsion 2, and after drying the first emulsion 2, the sheet or the plate-like member is peeled off to make the surface on the side of the object to be printed a smooth surface. Alternatively, after drying the first emulsion 2 applied to the mesh portion 10, the surface of the first emulsion 2 on the side of the object to be printed is pressed against a smoothing member having a smooth plane to make the surface on the side of the object to be printed a smooth surface.

[0030] Then, when in the state of FIG. 2(a), by exposing from the side of the object to be printed of the ink hole mask 3, a portion of the first emulsion 2 that is not covered by the light-shielding portion 3a of the ink hole mask 3 is cured to form a first layer 4 (see FIG. 2(b)). This first layer 4 constitutes a part of the printing pattern portion 20 (the portion on the squeegee side from the adjustment film surface 32) and also constitutes the ink adjustment portion 30.

[0031] Once the first layer 4 is formed, after removing the mask 3 for the ink holes, a second emulsion 5 made of a photosensitive resin is applied to the first layer 4 and dried. As a result, a layer of the second emulsion 5 is laminated on the first layer 4 from the side of the object to be printed. Then, a mask 6 for the pattern holes for forming the pattern holes 21 is disposed on the surface of the dried second emulsion 5 on the side of the object to be printed (see Fig. 2(b)). The mask 6 for the pattern holes is formed with a light-shielding portion 6a that does not allow light to pass through at the site where the pattern holes 21 are to be formed. This second emulsion 5 is also smoothed on the surface on the side of the object to be printed by the same smoothing process as the first emulsion 2 before the mask. Note that after forming the first layer 4, the uncured portion in the first emulsion 2 may be removed and then the second emulsion 5 may be applied.

[0032] In the state of Fig. 2(b), by exposing from the side of the object to be printed through the mask 6 for the pattern holes, the uncoated portion of the second emulsion 5 by the light-shielding portion 6a of the mask 6 for the pattern holes is cured to form a second layer 7 (see Fig. 2(c)).

[0033] Once the second layer 7 is formed, after removing the mask 6 for the pattern holes, the uncured portions in the first emulsion 2 and the second emulsion 5 are removed, whereby the pattern holes 21 are formed and the production of the screen printing plate 1 is completed (see Fig. 2(c)). That is, by removing the uncured portion of the first emulsion 2, the ink holes 31 are formed, and by removing the uncured portion of the second emulsion 5, the ink holding recesses 23 are formed. Then, the first layer 4 existing outside the pattern holes 21 and the second layer 7 constitute the printing pattern portion 20. According to this manufacturing method, the screen printing plate 1 in which the printing pattern portion 20 and the ink adjusting portion 30 are formed of a synthetic resin made of a photosensitive resin can be manufactured.

[0034] Incidentally, examples of the wire material 12 of the mesh portion 10 include nylon fiber, polyester fiber, polyarylate fiber, stainless steel wire, and tungsten steel wire. Examples of the photosensitive resin used for the first emulsion 2 and the second emulsion 5 include polyvinyl alcohol (PVA), polyvinyl acetate (PVAC), silicone resin, acrylic resin, epoxy resin, and nylon. The first emulsion 2 and the second emulsion 5 may be the same resin or different resins.

[0035] Although not shown in the drawings, the screen printing plate 1 of the present embodiment can also be manufactured by the following method. After applying and drying an emulsion made of a photosensitive resin to the mesh portion 10, it is cured by exposure using a mask with a negative-positive (light-shielding portion 3a) opposite to that of the ink hole mask 3, and then the uncured emulsion is removed, thereby forming an intermediate material in which columnar members having the same shape as the internal shape of the ink holes 31 are attached to the mesh portion 10.

[0036] Next, the side of the intermediate material to be printed is fixed by pressing it against a film, and a synthetic resin that cures by heat or solidifies by the volatilization of a solvent is filled from the squeegee surface side of the intermediate material into the mesh portion 10 of the intermediate material. At this time, the synthetic resin is prevented from adhering to the squeegee surface side of the columnar members in the intermediate material, and the surface of the filled synthetic resin on the squeegee surface side is made smooth. Note that the synthetic resin may be a photosensitive resin as long as it can be removed under conditions and methods different from those of the photosensitive resin forming the columnar members in the intermediate material.

[0037] After the above synthetic resin is solidified, after peeling off the film on the side to be printed, the columnar members of the intermediate material are removed using a predetermined solvent (for example, an aqueous solution of sodium periodate), whereby a first layer 4 having ink holes 31, similar to the first layer 4 shown in Fig. 2(b), can be formed. By forming a second layer 7 in the same manner as above on the formed first layer 4, the screen printing plate 1 can be manufactured. Thereby, it is possible to manufacture the screen printing plate 1 in which the ink adjustment portion 30 is formed of a synthetic resin different from the photosensitive resin.

[0038] Note that, in the same manner as the production of the above intermediate material, an emulsion made of a photosensitive resin is applied to the side of the object to be printed of the first layer 4 and dried, and then cured by exposure using a mask with a negative-positive inversion with respect to the pattern hole mask 6. After that, the uncured emulsion is removed to create a second intermediate material. Then, the above synthetic resin is applied to the portion from which the uncured emulsion has been removed, and its surface is made smooth. At this time, the synthetic resin is prevented from adhering to the surface on the side of the object to be printed in the second intermediate material. After that, when the applied synthetic resin solidifies to form the second layer 7, the second intermediate material is removed using a predetermined solvent, thereby forming the ink holding recess 23, and the production of the screen printing plate 1 is completed. According to this production method, it is possible to manufacture the screen printing plate 1 in which the printing pattern portion 20 and the ink adjustment portion 30 are formed of a synthetic resin different from the photosensitive resin.

[0039] Subsequently, screen printing using the above screen printing plate 1 will be described. This screen printing plate 1 is attached to a rectangular frame (not shown) and is used in a state where the surface on the side of the object to be printed faces downward and is disposed above the object to be printed. When performing screen printing, first, ink is supplied to the squeegee surface on the squeegee side of the screen printing plate 1, and the squeegee is moved so that the screen printing plate 1 does not contact the object to be printed, and the ink is coated on the squeegee surface side of the screen printing plate 1. At this time, the ink on the squeegee surface side passes through the ink holes 31 of the ink adjustment portion 30 and is held in the ink holding recess 23 surrounded by the inner surface of the pattern hole 21 and the adjustment film surface 32 in the ink adjustment portion 30.

[0040] Then, when the squeegee is moved in the printing direction so that the screen printing plate 1 contacts the object to be printed, the screen printing plate 1 is pressed against the object to be printed by the squeegee, so that the ink held in the ink holding recess 23 is transferred to the object to be printed, and a printing pattern having the same shape as the pattern hole 21 is printed.

[0041] The thickness of this printed ink is the same as the depth of the ink holding recess 23, that is, the distance between the pattern film surface 22 of the printing pattern portion 20 and the adjustment film surface 32 of the ink adjustment portion 30. This thickness is thinner than the thickness of the entire screen printing plate 1. Since the depth of the ink holding recess 23 is the same as the thickness of the second layer 7 formed on the surface of the first layer 4 on the object side to be printed, by setting the thickness of the second layer 7 (the coating amount of the second emulsion 5), the thickness of the ink to be printed can be adjusted.

[0042] Next, taking the screen printing plate for forming the internal electrodes of the MLCC as an example, with reference to FIGS. 3 to 6, a detailed description will be given while comparing an example having the configuration of the screen printing plate 1 of the first embodiment and a comparative example having the configuration of the conventional screen printing plate 100. The mesh portion 10 of the example and the mesh member 101 of the comparative example are each attached to a frame. The mesh portion 10 and the mesh member 101 are attached such that the extending directions of the warp and weft intersect at a predetermined angle with respect to the extending direction of the side of the attached frame. This reduces the occurrence of moiré (interference fringes).

[0043] In the example, a tungsten steel wire with a diameter of 13 μm is used as the wire 12, and a fabric woven into a #430 mesh (per inch) is used as the mesh portion 10. Also, in the example, the distance from the surface of the mesh portion 10 on the object side to the adjustment film surface 32 of the ink adjustment portion 30 is 2.5 μm, and the distance from the adjustment film surface 32 of the ink adjustment portion 30 to the pattern film surface 22 of the printing pattern portion 20 is 2.4 μm. On the other hand, in the comparative example, a stainless steel wire with a diameter of 15 μm is used as the wire, and a fabric woven into a #640 mesh (per inch) is used as the mesh member 101. Also, in the comparative example, the distance from the surface of the mesh member 101 on the object side to the surface of the pattern defining layer 102 on the object side is 1.6 μm. Note that the overall thickness of the comparative example is about 31 μm.

[0044] In the embodiment, a plurality of pattern holes 21 corresponding to rectangular printed patterns serving as internal electrodes are provided, and in the comparative example, an opening 102a having the same size and the same shape as the pattern hole 21 is provided. Hereinafter, the pattern hole 21 of the embodiment will be described as an example. The pattern hole 21 is formed in a rectangular shape and is arranged in a line at a predetermined interval in its long side direction and short side direction (see Fig. 3(a)). The long side direction of the pattern hole 21 is oriented in the same direction as the direction in which the side of the frame to which the mesh portion 10 is attached extends. In the present embodiment, the short side direction of the pattern hole 21 is oriented in the printing direction in which the squeegee moves during screen printing.

[0045] Furthermore, in the embodiment, a plurality of ink holes 31 are provided inside one pattern hole 21 (see Fig. 3(b)). The ink holes 31 open in a square shape and are arranged in a grid pattern with a gap. The direction in which these ink holes 31 are arranged is different from the direction in which the warp and weft of the mesh portion 10 extend, and is also different from the direction in which the pattern holes 21 are arranged. Thereby, by synchronizing the arrangement pattern of the pattern holes 21 and the arrangement pattern of the ink holes 31, it is possible to reduce the deviation of the portion where the ink holes 31 are not provided in one pattern hole 21. Therefore, when screen printing, it is possible to make the ink spread easily over the entire ink holding recess 23, and it is possible to suppress the streaks of the printed pattern.

[0046] In the present embodiment, the length of the pattern hole 21 in the long side direction is 800 μm, and the length in the short side direction is 165 μm. Also, the interval between the pattern holes 21 in the long side direction is 80 μm, and the interval between the pattern holes 21 in the short side direction is 100 μm. The ink hole 31 has a side length of about 21 μm and is arranged at an interval of about 18 μm in the directions in which its two orthogonal sides extend.

[0047] As shown in Figs. 4(a) and (b), the dimensional accuracy of the plate making of the above embodiment and the comparative example is substantially the same.

[0048] Next, using the above-described examples and comparative examples, a conductive paste of the same concentration was used as ink to print a plurality of printing patterns on a printed material, and the ink of the printing patterns was dried to create printed materials respectively. First, in each of the printed material of the example and the printed material of the comparative example, the thicknesses of the printing patterns at three locations shown in Fig. 5(a) were measured. Fig. 5(b) is a graph showing the maximum value of the thickness in each printing pattern. As shown in the figure, in the printed material of the comparative example, the thickness is in the range of 0.8 μm to 1.3 μm, whereas in the printed material of the example, the thickness is in the range of 0.6 μm to 0.8 μm, and it can be seen that the printed material of the example is printed thinner than the printed material of the comparative example.

[0049] As shown in Fig. 5(c), looking at the change in the thickness in the printing direction of each printing pattern, in the printed material of the comparative example, from one side to the other side in the printing direction, it gradually becomes thicker from one side toward the vicinity of the center, and after becoming the thickest in the vicinity of the center, it gradually becomes thinner toward the other side. That is, in the printed material of the comparative example, the shape of the thickness of the printing pattern is semi-circular, and it is printed in a shape far from the designed shape (a rectangular shape with a constant thickness). Therefore, in the manufacture of MLCCs, if the printed materials of the comparative example are stacked in hundreds of layers, there is a risk that the misalignment of the printing patterns (internal electrodes) will easily occur between the upper and lower layers.

[0050] On the other hand, in the printed material of the example, in the printing pattern of each part, it changes with a substantially constant thickness from one side to the other side in the printing direction. That is, in the printed material of the example, the shape of the thickness of the printing pattern is substantially rectangular, and it is printed in a shape close to the designed shape. Thereby, in the manufacture of MLCCs, even if the printed materials of the example are stacked in hundreds of layers, the misalignment of the printing patterns (internal electrodes) hardly occurs between the upper and lower layers. Further, since the thickness of the internal electrode is constant in the printed material of the example, sharp portions are hardly generated, and when the printed materials of the example are stacked, the lower internal electrode does not break through the upper dielectric.

[0051] As shown in the magnified photograph of FIG. 6, the printed matter of the example has less bleeding and is printed in a slightly thinner pattern than the printed pattern of the printed matter of the comparative example. This is presumably because the amount of ink transferred from the comparative example is larger than the amount of ink transferred from the example, making bleeding more likely to occur.

[0052] As described above, according to the present embodiment, in the screen printing plate 1, the ink held in the ink holding recess 23 surrounded by the inner surface of the pattern hole 21 and the adjusting film surface 32 in the ink adjusting unit 30 is transferred to the object to be printed. Since the depth of the ink holding recess 23 is thinner than the thickness of the entire screen printing plate 1, the ink can be printed with a thinner thickness compared to the conventional screen printing plate 100 in which the ink is printed with the same thickness as the entire screen printing plate.

[0053] Further, according to the present embodiment, as described above, since the thickness of the ink to be printed is determined by the depth of the ink holding recess 23, it is not necessary to reduce the overall thickness as in the conventional screen printing plates 100 and 200. Therefore, there is no need to consider reducing the thickness of the mesh portion 10, and a screen mesh used for a normal screen printing plate can be used as the mesh portion 10. As a result, even if the area of the screen printing plate is increased as in the conventional case, the quality does not become unstable such as uneven thickness, and the quality of the screen printing plate 1 can be stabilized while suppressing an increase in the cost of the screen printing plate 1.

[0054] Further, according to the present embodiment, as described above, since a screen mesh used for a normal screen printing plate can be used for the mesh portion 10, by using a strong mesh portion 10, a screen printing plate 1 that is difficult to be damaged or deformed can be provided. Also, a screen printing plate 1 having the same plate-making dimensional accuracy as that of the conventional screen printing plate can be obtained.

[0055] Furthermore, according to the present embodiment, since the thickness of the printed pattern printed on the object to be printed can be reduced, the amount of ink transferred to the object to be printed can be made less than before, the bleeding of the printed pattern can be reduced, and an increase in the cost of printing can be suppressed.

[0056] Also, during screen printing, if there is a portion where the pattern film surface 22 and the object to be printed are not in close contact, that portion may act like a capillary and ink may penetrate, resulting in bleeding. In contrast, according to the present embodiment, since the ink holding recess 23 in which the ink is held has a corner portion where the inner surface of the pattern hole 21 and the adjustment film surface 32 intersect, the direction in which the adhesive force of the ink acts becomes two directions, making it more difficult to move than the ink adhering to the flat portion, and making it easier for the ink to accumulate at the corner portion. As a result, even if there is a portion where the pattern film surface 22 and the object to be printed are not in close contact, the ink tends to stay due to the corner portion in the ink holding recess 23, making it difficult for the ink to penetrate into that portion and making it difficult for bleeding to occur.

[0057] Also, according to the present embodiment, as described above, the ink transferred to the object to be printed is held in the ink holding recess 23 through the ink hole 31 of the ink adjustment unit 30. The holding force of the ink in the ink holding recess 23 depends on the surface tension of the ink with respect to the ink adjustment unit 30. Therefore, by adjusting the relationship between the thickness of the ink adjustment unit 30 and the size of the ink hole 31, and the opening ratio of the ink hole 31 with respect to the area of the ink adjustment unit 30, it is also possible to set the amount of transfer of the ink present in the ink hole 31 to the object to be printed when printing the ink held in the ink holding recess 23 on the object to be printed. For example, if it is made easier for the ink in the ink hole 31 to move, the amount of transfer to the object to be printed increases, and if it is made more difficult for the ink in the ink hole 31 to move, it is possible to reduce the amount of transfer to the object to be printed. From the above, it is possible to easily respond to various printed patterns, the types of objects to be printed, inks, etc.

[0058] From the above, when the screen printing plate 1 of the present embodiment is used in the manufacture of MLCCs, the profile of the ink layer (outer shape and shape in the thickness direction) is close to the designed shape, and it becomes possible to form an internal electrode with a thinner thickness. Since it becomes possible to stack dielectric sheets (for example, ceramic films) having thin internal electrodes in more layers, it becomes possible to manufacture MLCCs with higher capacitance.

[0059] Subsequently, the screen printing plate 1A of the second embodiment will be described in detail with reference to FIG. 7(a). This screen printing plate 1A has an adjustment film surface 32 of the ink adjustment unit 30 formed in a concavo-convex shape. The screen printing plate 1A of the second embodiment is different only in the shape of the adjustment film surface 32, and the other configurations are the same as those of the screen printing plate 1 of the first embodiment. The same components will be denoted by the same reference numerals and described. The screen printing plate 1A has a concave portion 32a recessed on the squeegee side from the surface on the object-to-be-printed side in the mesh portion 10 and a convex portion 32b protruding on the object-to-be-printed side on the adjustment film surface 32 of the ink adjustment unit 30.

[0060] For example, when forming the first layer 4 on the mesh portion 10 woven with the wire 12, the screen printing plate 1A can form the first layer 4 with a concavo-convex adjustment film surface 32 by exposing through the ink hole mask 3 without performing a smoothing process on the surface on the object-to-be-printed side in the first emulsion 2 applied to the mesh portion 10. When applying the first emulsion 2 to the mesh portion 10, the first emulsion 2 may be applied in the same manner as in the manufacturing method of the first embodiment, or the first emulsion 2 may be applied to a thickness on the squeegee side from the surface on the object-to-be-printed side in the mesh portion 10 without embedding the surface on the object-to-be-printed side in the mesh portion 10.

[0061] According to the screen printing plate 1A of the second embodiment, in addition to the same operational effects as described above, the following operational effects can also be achieved.

[0062] Here, when the adjustment film surface of the ink adjustment unit is a smooth planar shape, when the screen printing plate is pressed against the object to be printed by the squeegee, if the smooth adjustment film surface contacts the object to be printed, the ink at the contacted part of the object to be printed will be excluded. The contact of this adjustment film layer with the object to be printed becomes easier as it moves away from the edge of the pattern hole. Furthermore, the larger the opening area of the pattern hole (the area of the printed pattern), or the thinner the depth of the ink holding recess (the thickness of the printed pattern), the easier it is to contact the object to be printed.

[0063] Then, when the squeegee moves in the printing direction while the adjustment film surface is in contact with the object to be printed, as the contacted part moves, the area where the ink is excluded expands, and there is a risk of defects such as streaks and pinholes occurring in the printed pattern. Also, since the central part of the adjustment film surface is likely to contact the object to be printed, a saddle phenomenon where the thickness of the printed pattern becomes thinner as it moves away from the peripheral part towards the central side is likely to occur in the printed pattern. And there is a risk that the dielectric sheet with the printed pattern showing the saddle phenomenon as the internal electrode cannot be accurately laminated.

[0064] On the other hand, according to the screen printing plate 1A of the second embodiment, since the adjustment film surface 32 of the ink adjustment unit 30 is formed in an uneven shape, even when the adjustment film surface 32 contacts the object to be printed when pressed by the squeegee, only the convex portions 32b of the adjustment film surface 32 contact the object to be printed, and the concave portions 32a do not contact the object to be printed. Therefore, the area where the ink is excluded is limited, and even when the squeegee moves in the printing direction, the area where the ink is excluded does not expand. And in this screen printing plate 1A, when the ink is coated on the squeegee surface side, the ink is also held in the concave portions 32a. Therefore, when pressed against the object to be printed by the squeegee, the ink held in the concave portions 32a is extruded onto the object to be printed. As a result, since the ink from the concave portions 32a is supplied to the area where the ink has been excluded due to the contact of the convex portions 32b, the occurrence of defects such as streaks and pinholes can be suppressed in the printed pattern.

[0065] Also, according to the screen printing plate 1A, as described above, since the ink held in the recess 32a is extruded onto the object to be printed by the squeegee, the occurrence of the saddle phenomenon in the printing pattern can be suppressed. Therefore, it is possible to print with a constant thickness even for a large-area printing pattern, and it is also possible to further reduce the thickness of the printing pattern. Therefore, for example, when forming an energized portion of an electronic circuit such as a printed circuit board by screen printing, the thickness of a wide solid portion or the like in the energized portion, which has a large printing area, can be made thinner than before and can be formed with a constant thickness. Further, conventionally, due to an excess of ink in a portion with a large printing area, the ink might overflow from the desired printing pattern. In contrast, according to the screen printing plate 1A, since the thickness of the ink can be made uniform even for a pattern with a large printing area, the ink does not overflow, and the desired printing pattern can be accurately formed.

[0066] Subsequently, the screen printing plate 1B of the third embodiment will be described in detail with reference to FIG. 7(b). The screen printing plate 1B of this third embodiment is different only in that the thickness of the printing pattern portion 20 is different, and the other configurations are the same as those of the screen printing plate 1 of the first embodiment. The same components will be denoted by the same reference numerals and described. The screen printing plate 1B is provided with a protruding weir 24 that protrudes from the pattern film surface 22 around the pattern hole 21. Due to the presence of this protruding weir 24, the thickness of the printing pattern portion 20 is partially different.

[0067] This protruding weir 24 can be formed, for example, by forming the second layer 7 and removing the pattern hole mask 6, then applying an emulsion of a photosensitive resin to the surface of the second layer 7 on the object-to-be-printed side and drying it, and then exposing it through a mask for forming the protruding weir 24 and removing the uncured emulsion.

[0068] According to the screen printing plate 1B of the third embodiment, in addition to the same operational effects as described above, the following operational effects can also be achieved. Specifically, according to the screen printing plate 1B, when screen printing, when the screen printing plate 1B is pressed against the object to be printed by the squeegee, the protruding weir 24 abuts against the object to be printed, and the pattern film surface 22 does not contact the object to be printed. Thereby, since the contact area with the object to be printed can be reduced, it is possible to avoid the object to be printed from being soiled or damaged due to dirt, scratches, etc. on the screen printing plate 1B side.

[0069] Subsequently, the screen printing plate 1C of the fourth embodiment will be described in detail with reference to FIG. 7(c). In the screen printing plate 1C, the surface of the ink adjusting unit 30 on the squeegee side is located closer to the object to be printed side than the surface of the mesh unit 10 on the object to be printed side. The screen printing plate 1C of this fourth embodiment is the same as the screen printing plate 1 of the first embodiment in other configurations except that the configuration of the ink adjusting unit 30 is different, and the same reference numerals are given to the same configurations for description.

[0070] Since the surface of the ink adjusting unit 30 of the screen printing plate 1C of the fourth embodiment is located closer to the object to be printed side than the surface of the mesh unit 10 on the object to be printed side, there is a gap between the mesh unit 10 and the ink adjusting unit 30. The ink adjusting unit 30 of the screen printing plate 1C is not supported by the mesh unit 10, unlike the above-described screen printing plates 1 to 1B, etc., and is only supported by the printing pattern unit 20.

[0071] This screen-printed version 1C, for example, when forming the first layer 4, applies the first emulsion 2 to the mesh portion 10 thicker (e.g., 7 μm to 8 μm or more) than when it is a screen printing plate 1 and dries it. Then, it exposes from the side of the object to be printed through a mask for forming the ink adjustment portion 30. At this time, the exposure amount is set such that the first emulsion 2 cures by the thickness of the ink adjustment portion 30 to be formed. Thereby, the portion of the ink adjustment portion 30 in the first layer 4 is formed. Subsequently, through a mask for forming a portion outside the ink adjustment portion 30, the entire thickness direction of the first emulsion 2 is exposed and cured so that it becomes photosensitive. Thereby, the first layer 4 in which the ink adjustment portion 30 is not in contact with the mesh portion 10 can be formed. After that, similar to the case of the screen printing plate 1, the screen printing plate 1C can be manufactured by forming the second layer 7 on the first layer 4.

[0072] According to the screen printing plate 1C of the fourth embodiment, in addition to the same operational effects as described above, the following operational effects can be achieved.

[0073] Here, depending on the relationship between the arrangement pattern of the ink holes 31 in the ink adjustment portion 30 and the arrangement pattern of the through holes 11 in the mesh portion 10, there will be ink holes 31 that coincide with the portion between the through holes 11 in the mesh portion 10 (e.g., the wire 12). At this time, if the size of the ink holes 31 is smaller than the portion between the through holes 11, the ink holes 31 will be blocked by the corresponding portion of the mesh portion 10. When screen printing in this state, since ink is not supplied from the blocked ink holes 31 to the ink holding recess 23 side, it is easy for streaks or pinballs to occur in the printed pattern. This problem becomes more prominent as the size of the pattern holes 21 becomes smaller. Or, it becomes more prominent as the number of ink holes 31 in one pattern hole 21 decreases.

[0074] In contrast, according to the screen printing plate 1C of the fourth embodiment, since the ink adjusting part 30 having the ink holes 31 is separated from the mesh part 10 and there is a gap between the ink adjusting part 30 and the mesh part 10, the ink holes 31 are not blocked by the mesh part 10. As a result, when screen printing, ink passes through the gap between the ink adjusting part 30 and the mesh part 10, so that ink can be supplied from all the ink holes 31 in the pattern holes 21 to the ink holding recess 23 side, and there will be no streaks or pinholes in the printed pattern. Therefore, it becomes possible to print a smaller printed pattern or a thin and delicate printed pattern well without streaks.

[0075] In addition, according to the above screen printing plates 1, 1A, 1B, and 1C, the following effects can be achieved. Specifically, for example, when the ink adjusting part (the first layer) is made porous and ink is supplied from the squeegee side to the object to be printed side through the continuous holes formed by the porosity, since the continuous holes are continuous with porous bubbles, the flow path of the ink is narrower than the ink holes 31 and the flow path is in a state of being tortuous. Therefore, due to the increase in the flow resistance of the ink, when the ink is coated on the squeegee side, there is a risk that the ink holding recess on the object to be printed side will not be sufficiently supplied with ink, and depending on the type of ink, it is likely to be clogged. In contrast, according to the present embodiment, since the ink holes 31 of the ink adjusting part 30 are formed by exposure to be through holes extending straight from the squeegee side to the object to be printed side of the ink adjusting part 30, the flow resistance of the ink can be made lower than that of the continuous holes formed by porosity, and when the ink is coated on the squeegee side, the ink can be sufficiently supplied to the ink holding recess 23 through the ink holes 31, and it can be made less likely to be clogged compared with the continuous holes. Note that the ink adjusting part 30 (the first layer 4) may be made porous, but it is preferably made of an impermeable material through which ink does not pass or impregnate, thereby suppressing an increase in the amount of ink used during screen printing.

[0076] As described above, the present invention has been explained by giving preferred embodiments. However, the present invention is not limited to the above embodiments, and as shown below, various improvements and design changes are possible without departing from the gist of the present invention.

[0077] For example, in the above embodiment, the mesh portion 10 is shown as being woven from the wire 12, but it is not limited thereto, and a sheet (film) made of metal or synthetic resin in which a plurality of through holes are formed may be used as the mesh portion.

[0078] Also, in the above embodiment, the ink holes 31 are formed using a photosensitive resin, but it is not limited thereto, and the ink holes may be formed by laser, drill, punching, or the like.

[0079] Also, in the above embodiment, in the ink adjustment unit 30, a plurality of ink holes 31 are provided for each pattern hole 21, but it is not limited thereto, and one ink hole 31 may be provided for each pattern hole 21.

Explanation of Reference Numerals

[0080] 1 Screen printing plate 1A Screen printing plate 1B Screen printing plate 1C Screen printing plate 4 First layer 7 Second layer 10 Mesh portion 11 Through hole 20 Printing pattern portion 21 Pattern hole 22 Pattern film surface 23 Ink holding recess 30 Ink adjustment unit 31 Ink hole 32 Adjustment film surface 32a Recess 32b Projection

Claims

1. A mesh part formed of metal or synthetic resin and having a plurality of through holes; A printing pattern part formed of synthetic resin so that the surface on the printed material side in the mesh part is embedded, and having pattern holes corresponding to the printing pattern; An ink adjusting part formed of synthetic resin inside the pattern holes and having at least one ink hole that is smaller than the pattern holes and is open; and the ink adjusting part comprises: The surface on the printed material side in the ink adjusting part is located on the squeegee side with respect to the surface on the printed material side in the printing pattern part. A screen printing plate, characterized in that.

2. The ink adjusting part: The surface on the printed material side is formed in an uneven shape. A screen printing plate according to claim 1, characterized in that.

3. A method for manufacturing a screen printing plate for manufacturing the screen printing plate according to claim 1 or claim 2, Forming a first layer in which the surface on the printed material side in the mesh part is embedded, and which becomes a part on the squeegee side with respect to the surface on the printed material side of the ink adjusting part in the printing pattern part, and in which the part corresponding to the pattern holes becomes the ink adjusting part; Forming a second layer on the printed material side of the formed first layer, which becomes the remaining part of the printing pattern part and has the pattern holes. A method for manufacturing a screen printing plate, characterized in that.

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