Screen mask manufacturing method

Abstract

To provide a screen mask capable of improving printing accuracy, and a manufacturing method of the screen mask.SOLUTION: A manufacturing method of screen mask according to one embodiment includes: a first layer formation step which coats a support material having a hole coating materials can pass with first emulsion to form a first emulsion layer; a first patterning step which performs exposure in a prescribed first exposure pattern to the first emulsion layer; a second layer formation step which additionally coats the first emulsion layer with second emulsion to form a second emulsion layer; a second patterning step which performs exposure in a second exposure pattern different from the first exposure pattern; and etching treatment which forms openings in the first emulsion layer and the second emulsion layer by etching treatment and forms a step on one surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a screen mask and a method for manufacturing the screen mask. [Background technology]

[0002] Screen printing, a printing technique, is a method of forming a desired print on a substrate using a screen mask with a predetermined pattern of openings formed from a resin composition on a mesh support material. This screen printing method is used for various printing processes, such as printing wiring, electrodes, and fluorescent materials, and is used in a variety of fields, including electronic components.

[0003] In recent years, the miniaturization and high quality of electronic components has led to a demand for higher precision screen masks.

[0004] For example, a screen mask includes a mesh with holes that allow the coating material to pass through, and a mask film with pattern openings provided in the mesh. The pattern openings formed in the mask film have a shape corresponding to, for example, a printing pattern and a predetermined width. For example, after an emulsion that forms the mask film is applied to the mesh, the pattern openings are formed by an exposure process with a photomask superimposed thereon. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-169783 Summary of the Invention [Problem to be solved by the invention]

[0006] There is a demand for such a screen mask and a method for manufacturing the screen mask that can improve printing accuracy. [Means for solving the problem]

[0007] A method for manufacturing a screen mask according to one embodiment includes a first layer forming step of forming a first emulsion layer by applying a first emulsion to a support material having holes that allow the coating material to pass through; a first patterning step of exposing the first emulsion layer with a predetermined first exposure pattern; a second layer forming step of over-coating a second emulsion on one side of the first emulsion layer to form a second emulsion layer; a second patterning step of exposing the first emulsion layer with a second exposure pattern that is different from the first exposure pattern after the first patterning step; and a second patterning step of exposing the second emulsion layer with a second exposure pattern that is different from the first exposure pattern after the second patterning step. Uncured area and an etching process for removing the first exposure pattern, wherein the exposure is maskless exposure, and the first exposure pattern forms an opening wider than the opening formed by the second exposure pattern. Uncured area The hardened portion of the second exposure pattern is a pattern having the same structure as that of the first patterning step. Uncured area and at least a part of the hardened portion in the first patterning step, and the second patterning step hardens a region including at least a part of the first emulsion layer and at least a part of the second emulsion layer from one side of the second emulsion layer, and the second patterning step hardens a region including at least a part of the first emulsion layer and at least a part of the second emulsion layer from one side of the second emulsion layer, and Uncured area Among these, the portion that forms the inner wall of the opening and the portion that will become a protrusion at the edge of the opening in the second emulsion layer on one side of the hardened portion hardened in the first patterning step are hardened, and in the etching process, the unhardened portions of the first emulsion and the second emulsion are removed to form an opening in the first emulsion layer and the second emulsion layer, and a protrusion composed of part of the second emulsion layer is formed at the edge of the opening on the surface on the one side.

[0008] Screen Mass according to another embodiment In the method for producing the film, the second emulsion layer is softer than the first emulsion layer.

[0009] Another embodiment of the screen mask In the manufacturing method of , the protrusions and the surface layer portions of the inner wall surfaces of the openings connected to the protrusions are made of the second emulsion layer. In another embodiment of the method for manufacturing a screen mask, the opening is a linear slit opening that penetrates a mask film having the first emulsion layer and the second emulsion layer stacked on one side of the first emulsion layer in the thickness direction from the front side to the back side. [Effects of the Invention]

[0010] According to the embodiments of the present invention, it is possible to provide a screen mask and a method for manufacturing the screen mask that can improve printing accuracy. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram of a screen printing apparatus according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of the screen mask according to the embodiment. [Figure 3] FIG. [Figure 4] FIG. 2 is an explanatory diagram showing a configuration of a part of the screen mask. [Figure 5] 3A to 3C are explanatory views showing a method for manufacturing the screen mask. [Figure 6] FIG. 2 is an explanatory diagram showing the shapes of pattern openings and printing shapes of the screen mask of the present invention and Comparative Example 1. [Figure 7] FIG. 2 is an explanatory diagram showing the relationship between the shape of the screen mask and the print shape. [Figure 8] FIG. 2 is an explanatory diagram showing the relationship between the shape of the screen mask and the print shape. [Figure 9] FIG. 10 is an explanatory diagram of a screen printing apparatus according to a second embodiment. [Figure 10] FIG. 2 is an explanatory diagram showing a configuration of a part of the screen mask. [Figure 11] 3A to 3C are explanatory views showing a method for manufacturing the screen mask. [Figure 12] 3A and 3B are explanatory diagrams showing a printing method using the screen printing apparatus according to the embodiment. [Figure 13] FIG. 10 is an explanatory diagram showing the shapes of pattern openings and printing shapes of the same screen mask and Comparative Example 2. [Figure 14] FIG. 2 is an explanatory diagram showing the relationship between the shape of the screen mask and the print shape. [Figure 15] 10A and 10B are explanatory diagrams showing the shape of a mask film of a screen mask according to another embodiment. [Figure 16] 10A and 10B are explanatory diagrams showing the shape of a mask film of a screen mask according to another embodiment. [Figure 17] 10A and 10B are explanatory diagrams showing the shape of a mask film of a screen mask according to another embodiment. [Figure 18] 10A to 10C are explanatory diagrams showing the configuration and manufacturing method of a screen mask according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First embodiment] A screen printing apparatus 10 and a screen mask 20 according to a first embodiment of the present invention will be described below with reference to Figs. 1 to 8. Fig. 1 is an explanatory diagram showing the screen printing apparatus 10 according to this embodiment. Fig. 2 is a perspective view of the screen mask 20, and Fig. 3 is a cross-sectional view thereof. Fig. 4 is an explanatory diagram showing the configuration of a portion of the screen mask 20. Note that in each figure, the configuration is enlarged, reduced, or omitted as appropriate for ease of explanation. In the figures, arrows X, Y, and Z indicate three mutually perpendicular directions.

[0013] As shown in Figure 1, the screen printing apparatus 10 includes a screen mask 20, a holding member 12 that holds the printing medium Ba facing the front surface (one side) 20a, which is the printing side of the screen mask 20, a squeegee 13 that is configured to be movable while in contact with the back surface (other side) 20b, which is the opposite side to the printing side of the screen mask 20, a moving unit that moves the squeegee 13, and a support unit that supports the screen mask 20 facing the printing medium Ba.

[0014] The screen printing apparatus 10 forms various printing materials in predetermined patterns on the surface of a printing medium Ba. For example, it is used in the manufacture of chip components (capacitors, chip resistors, inductors, thermistors, etc.), touch panels, liquid crystal display (LCD) substrate seals, LTCC (Low Temperature Co-fired ceramics) substrates, solar cell electrodes, and other electronic components.

[0015] 1 and 2, the screen mask 20 includes a frame 21, a mesh 22 that is a support material stretched over the frame 21, and a mask film 23 formed on the mesh 22. In the screen mask 20, the side that faces the surface of the printing medium Ba when printing is performed is called the front surface 20a, and the opposite side, to which the coating material Pe is supplied, is called the back surface 20b.

[0016] The frame 21 has two pairs of parallel sides and is configured in a frame shape with, for example, a rectangular opening of a desired size. The frame 21 supports the outer periphery of the mesh 22, and the mesh 22 is stretched across the opening. In this embodiment, as an example, the dimension of the opening of the frame 21 in the Y direction is 275 mm, and the dimension of the opening in the X direction is 275 mm.

[0017] The frame 21 also functions as a frame for holding a predetermined amount of coating material Pe on the rear surface of the mask film 23. The frame 21 and the mesh 22 are joined at a joint with, for example, a synthetic rubber or cyanoacrylate adhesive.

[0018] The mesh 22 is a woven fabric formed by weaving warp threads 22a and weft threads 22b, and has many holes 22c that allow the coating material Pe to pass through. The warp threads 22a and weft threads 22b are, for example, metal wires such as stainless steel, or fibers made of resin such as polyester. The warp threads 22a and weft threads 22b each extend obliquely with respect to, for example, the movement direction of the squeegee 13 (first direction).

[0019] A mask film 23 having a predetermined pattern of openings 23a is formed on the mesh 22. That is, the mesh 22 holds the mask film 23 in the opening portions of the frame 21.

[0020] The mask film 23 is a layer made of a photocurable resin composition, such as PVA, PVAc, silicone resin, acrylic resin, or epoxy resin. For example, as shown in Fig. 5, the mask film 23 has a two-layer structure formed by laminating a base layer 23b and a cover layer 23c. As an example, the cover layer 23c is made of a material that is more flexible than the base layer 23b.

[0021] The thickness of the mask film 23 is set to, for example, 10 μm to 100 μm.

[0022] The mask film 23 is formed on the mesh 22 and is placed in the opening portion of the frame 21. A predetermined pattern opening 23a for printing is formed in the mask film 23 by exposure.

[0023] The minimum opening width of the pattern opening 23a, i.e., the width dimension of the opening at the narrowest part of the pattern opening 23a, is 30 μm or less. Here, as an example, the dimension at the surface of the mask film 23, i.e., the surface 20a facing the printing medium Ba, is used as the standard.

[0024] The pattern openings 23a are linear pattern holes that form slits that are patterned to correspond to the printing pattern and penetrate the mask film 23 in the thickness direction (depth direction).

[0025] A protrusion 23d protruding toward the printing surface is formed at the edge (rim portion) of the pattern opening 23a on the printing surface side. As shown in Fig. 5, the protrusion 23d and the surface layer portion of the inner wall surface of the pattern opening 23a connected to the protrusion 23d of the mask film 23 are composed of a cover layer 23c.

[0026] As shown in FIG. 4, the protrusion 23d is set to satisfy all of the formulas 1, 2, and 3: 2 μm≦ΔTb≦2 / 3T (Formula 1) 10μm≦Wc≦100μm (Formula 2) Tm≦ T-ΔTb (Formula 3) Here, T is the total thickness (including the thickness of the mesh and emulsion), ΔTb is the step thickness from the printing surface, Wc is the width of the step on one side of the pattern opening 23a, and Tm is the thickness of the mesh.

[0027] The mask film 23 forms a printed portion where the photosensitive resin is not present in the pattern openings 23a and the coating material Pe can pass from the back surface to the front surface through the holes in the mesh 22. The areas of the mask film 23 other than the pattern openings 23a where the holes in the mesh 22 are blocked with photosensitive resin form a non-printed portion that does not allow the ink serving as the coating material Pe to pass through.

[0028] The mesh 22 on which the mask film 23 is formed is configured to be elastically deformable so that it is flexed and deformed by, for example, the pressing force of the squeegee 13 and restored to its original shape when the pressing force is released. With the coating material Pe held in the pattern openings 23a of the mask film 23, the mask film 23 moves toward and away from the printing medium Ba due to the elastic deformation of the mesh 22, and the coating material Pe is transferred from the pattern openings 23a to the printing medium Ba.

[0029] The squeegee 13 is formed, for example, in the shape of a thin plate from a material such as urethane rubber, silicone rubber, synthetic rubber, metal, or plastic. For example, the squeegee 13 is chamfered to reduce the thickness of its tip. The squeegee 13 is configured to be movable relative to the frame 21. For example, the squeegee 13 is configured to have a length that spans the entire length of the area of ​​the mask film 23 in a direction perpendicular to the direction of movement. With the tip portion 13a of the squeegee 13 in contact with the back surface 20b of the screen mask 20 and pressed against the front surface, the squeegee 13 moves in the direction of movement along arrow A in FIG. 1, thereby pressing against the entire surface of the mask film 23 and forcing the coating material Pe to the front surface from the pattern openings 23a in which the coating material Pe has been pre-filled.

[0030] The support section supports the frame 21 in parallel with and at a predetermined distance from the printing medium Ba. The movement section moves the squeegee 13 at a predetermined speed in a predetermined direction.

[0031] Next, a method for manufacturing the screen mask 20 according to this embodiment will be described with reference to Fig. 5. Fig. 5 is an explanatory diagram showing the method for manufacturing the screen mask 20. The method for manufacturing the screen mask 20 includes a first layer forming step, a first patterning step, a second layer forming step, a seasoning step, a second patterning step, and an etching step.

[0032] The first emulsion is, for example, a photocurable resin, which is a liquid including, for example, polyvinyl alcohol (PVA), polyvinyl acetate (PVAc), silicone resin, acrylic resin, epoxy resin, and the like.

[0033] In the first layer formation process, a first emulsion Pm1 is applied to a support material having holes that allow the coating material to pass through, forming a first emulsion layer. Specifically, first, a mesh 22 is attached to the frame 21 so that it is approximately flat, and then, as shown in ST1, a coating process is performed in which the first emulsion Pm1 is applied to the mesh 22, thereby forming a flat base layer 23b on the mesh 22. At this time, the thickness varies depending on the number of applications, so multiple applications may be repeated as necessary. In addition, the film thickness may be measured after drying, and additional applications may be made if necessary. In this embodiment, the thickness of the emulsion Pm1 is set so that the emulsion thickness of the first emulsion layer after drying is approximately 5 to 20 μm.

[0034] Next, a first patterning step is performed in which the first emulsion layer is exposed to a predetermined first exposure pattern. For example, as shown in ST2, a first maskless exposure process is performed using a maskless exposure machine that does not use a photomask. Specifically, the surface side of the base layer 23b is placed facing a light source such as an ultraviolet lamp or ultraviolet LED in the predetermined exposure pattern area, and light is irradiated from the light source to illuminate the surface of the emulsion. The first exposed portion of the base layer 23b that is exposed by the first exposure process becomes a first emulsion hardened portion (first photo-crosslinked portion) Pa1 that is hardened by ultraviolet light. Meanwhile, the first non-exposed portion of the base layer 23b that is the portion excluding the first exposed portion becomes an unhardened portion Pb1 where the emulsion does not harden. The first unhardened portion Pb1 (first non-exposed portion) constitutes a first removal target portion that will be removed in a later process to form a base opening.

[0035] Here, the first exposure pattern is a pattern that forms a base opening that is wider than the pattern width of the second exposure pattern, taking into account misalignment with the second pattern that will be laminated in a later process. As a result, the base layer 23b is patterned, and a first removal portion that will be removed in a later etching process and that will form the base opening is formed.

[0036] Next, as shown in ST3, a coating process is performed in which the second emulsion Pm2 is applied onto the base layer 23b, thereby forming a cover layer 23c from the second emulsion Pm2 on the printing surface side of the base layer 23b. Since the thickness varies depending on the number of applications, multiple applications are required. Furthermore, the film thickness is measured after drying, and additional applications may be performed if necessary. In this embodiment, the thickness of the emulsion Pm2 is set so that the milk thickness of the cover layer 23c after drying is approximately 2 to 50 μm. Then, a seasoning process is performed in which the frame is left to stand for approximately three hours under the conditions required for the maskless exposure process, thereby bringing the frame temperature to approximately the same as that during the first maskless exposure process.

[0037] Next, a second patterning step is performed, in which the emulsion Pm2 is exposed to a second exposure pattern different from the first exposure pattern. That is, as shown in ST4, a second maskless exposure process is performed using a maskless exposure machine that does not use a photomask. Specifically, in a predetermined second exposure pattern area, the surface side of the emulsion Pm2 is placed facing a light source such as an ultraviolet lamp or ultraviolet LED, and light is irradiated from the light source to illuminate the surface of the emulsion Pm2. The second exposure process hardens the ultraviolet-irradiated portions of the emulsion Pm2 corresponding to the exposure pattern area. That is, the second exposed portions of the cover layer 23c that are exposed by the second exposure process form second emulsion-hardened portions (second photo-crosslinked portions) Pa2 that are hardened by the ultraviolet light. A portion of the second emulsion-hardened portions Pa2 constitutes the protrusions 23d, and the other portion constitutes the inner walls of the pattern openings 23a. Meanwhile, the second unexposed portions of the cover layer 23c, excluding the second exposed portions, become second unhardened portions Pb2, in which the emulsion does not harden. The second uncured portion Pb2 includes a second portion to be removed, which will be removed in a later step to form the pattern opening 23a including the base opening.

[0038] Both the first exposure process and the second exposure process are exposure processes in which light is irradiated from the printing surface side, and the second exposure process is performed from the same direction as the first exposure process, but with a pattern that targets a narrower area than the first exposure process, thereby hardening a predetermined range. In the second patterning step, an area including at least a portion of the first emulsion layer and at least a portion of the second emulsion layer is exposed by exposure with a second exposure pattern different from the first exposure pattern. That is, among the first non-exposed areas of the first emulsion layer that were not hardened in the first exposure process, the area that forms the inner wall of the pattern opening 23a and the part of the second emulsion layer that is on one side of the first exposed area hardened in the first exposure process and forms the protrusion 23d at the edge of the pattern opening 23a are hardened by the second exposure process.

[0039] Thereafter, an etching process is performed in which at least one side of the mask film is washed away with water or a solvent. This process forms pattern openings 23a that penetrate from the front side to the back side in the thickness direction, where the uncured portions Pb1 and Pb2 of the emulsions Pm1 and Pm2 are washed away, and protrusions 23d that become steps are formed at the edges of the pattern openings 23a.

[0040] Next, a method for producing a printed matter by a screen printing method using the screen printing apparatus 10 according to this embodiment will be described with reference to Fig. 1. First, the front side of the screen mask 20 is placed facing the surface of the printing medium Ba held by the holding member 12.

[0041] Then, as shown by the two-dot chain line in FIG. 1, a highly viscous paste-like coating material Pe is supplied from the back side of the screen mask 20, i.e., the side opposite to the printing medium Ba, and the coating material Pe is filled into the pattern openings 23a.

[0042] Next, a squeegee 13 is placed on the back surface 20b of the screen mask 20, i.e., the surface opposite the printing surface. At this time, for example, the squeegee 13 is placed at a predetermined angle relative to the front surface of the printing medium Ba. Then, the squeegee 13 is moved at a predetermined speed while pressing the mesh 22 and the back surface of the mask film 23 toward the printing medium Ba with a predetermined printing pressure. The squeegee 13 presses against the mask film 23 over the entire back surface of the mask film 23. The pressure of the squeegee 13 causes the pressed portion of the mask film 23 to deform so that it is displaced toward the front surface and comes into contact with the printing medium Ba. The coating material Pe that the squeegee 13 has passed through is pushed out toward the printing medium Ba through the pattern openings 23a.

[0043] After the squeegee 13 has passed, the mask film 23 and mesh 22 deform to restore their original shape and separate from the print medium Ba, while some of the coating material Pe is transferred and remains on the print medium Ba, thereby printing a pattern on the print medium Ba and completing the print. At this time, part of the back side of the coating material Pe remains on the mask film 23 side. The coating material Pe can be made of various materials including, for example, metal and resin materials, and a variety of materials are used depending on the type of printing object, such as electronic components or displays.

[0044] The screen mask 20, the screen printing apparatus 10, and the screen printing method configured as above enable printing with high precision.

[0045] 6 is an explanatory diagram showing the shape of the pattern openings and the printing shape of the screen mask 20 and a screen mask 20A according to a comparative example. As a comparative example, the screen mask 20A is shown, which does not have the protrusions 23d and has a flat surface on the printing surface (P surface) side.

[0046] As shown in FIG. 6, the screen mask 20 having the protrusions 23d on the edges of the openings on the printing surface side can reduce bleeding of the print shape compared to the configuration of Comparative Example 1, enabling printing with high precision.

[0047] Furthermore, according to the above embodiment, the screen mask 20 is configured to satisfy 2 μm≦ΔTb≦2 / 3T (formula 1), so that a desired printing pressure can be ensured at the edge with a simple manufacturing method.

[0048] 7, if 2 μm > ΔTb, the height of the protrusions 23d is insufficient to obtain the desired printing pressure, and the bleeding reduction effect is not obtained. On the other hand, if ΔTb > 2 / 3T, the strength is insufficient, and durability during printing is reduced.

[0049] Furthermore, by configuring the screen mask 20 to satisfy the relationship 10 μm≦Wc≦100 μm (Equation 2), the mask film is less likely to be damaged and the desired printing pressure can be ensured at the edges. That is, as shown in Figure 8, when 10 μm > Wc, the protrusions 23d on the printing surface side are easily damaged, and when Wc > 100 μm, the pressure applied to the protrusions 23d is relatively small, making it impossible to obtain the required printing pressure.

[0050] Furthermore, according to this embodiment, the first exposure process and the second exposure process are both exposure processes in which light is irradiated from the printing surface side, and by varying conditions such as the exposure amount and exposure time, it is possible to easily form a pattern opening having a protrusion 23d.

[0051] [Second embodiment] A screen printing apparatus 10 and a screen mask 120 according to a second embodiment of the present invention will be described below with reference to Fig. 1 and Figs. 9 to 11. Fig. 9 is an explanatory diagram of the screen printing apparatus according to this embodiment, and Fig. 10 is an explanatory diagram showing the configuration of a portion of the screen mask 120. Fig. 11 is an explanatory diagram showing a manufacturing method of the screen mask 120. Note that the screen mask 120 according to this embodiment does not have protrusions 23d, and has steps on the inner walls of the pattern openings 23a. Other configurations are similar to those of the screen mask 20 according to the first embodiment, so a description of the common parts will be omitted.

[0052] As shown in Figure 9, the screen printing apparatus 10 includes a screen mask 120, a holding member 12 that holds the printing medium Ba facing the front surface (one side) 20a, which is the printing surface side of the screen mask 120, a squeegee 13 that is configured to be movable while in contact with the back surface (other side) 20b, which is opposite the printing surface side of the screen mask 120, a moving unit that moves the squeegee 13, and a support unit that supports the screen mask 120 facing the printing medium Ba.

[0053] 9, the screen mask 120 includes a frame 21, a mesh 22 that is a support material stretched over the frame 21, and a mask film 123 formed on the mesh 22. In the screen mask 120, the side that faces the surface of the printing medium Ba when printing is performed is called a front surface 120a, and the opposite side, to which the coating material Pe is supplied, is called a back surface 120b.

[0054] The mask film 123 is a layer made of a photocurable resin composition, such as PVA, PVAc, silicone resin, acrylic resin, or epoxy resin.

[0055] The thickness of the mask film 123 is set to, for example, 10 μm to 100 μm.

[0056] The mask film 123 is formed on the mesh 22 and is placed in the opening portion of the frame 21. A predetermined pattern opening 123a for printing is formed in the mask film 123 by exposure.

[0057] The minimum opening width of the pattern opening 123a, i.e., the width dimension of the opening at the narrowest part of the pattern opening 123a, is 30 μm or less. Here, as an example, the dimension at the surface of the mask film 123, i.e., the surface 20a facing the printing medium Ba, is used as the standard.

[0058] The pattern openings 123a are linear pattern holes that form slits that pass through the mask film 123 in the depth direction and have a pattern corresponding to the printing pattern.

[0059] The pattern opening 123a is configured so that the opening edge on the supply side opposite the printing surface, which is one side in the direction of discharging the coating material, is wider than the opening edge on the printing surface side. The inner wall surface of the pattern opening 123a is configured asymmetrically, with the opening edge wider on one side in the first direction, which is the direction of squeegee movement, than on the other side. The printing surface side of the pattern opening 123a is configured flat. In other words, no protrusions 23d are formed.

[0060] As an example, the inner wall of the pattern opening 123a has a protruding guide portion 123e that protrudes into the opening midway in the depth direction on the rear side in the squeegee movement direction, and this guide portion 123e forms a step 123f on the side wall of the pattern opening 123a. The pattern opening 123a has a large-width portion on the squeegee side and a small-width portion on the printing surface side, which are connected via an inflection portion caused by the step 123f. The large-width portion and the small-width portion are continuous and form a slit that penetrates the mask film 23 in the depth direction in a pattern corresponding to the printing pattern.

[0061] The shape of the pattern opening 123a is as shown in FIG. ΔW≦ΔT≦2 / 3T (Formula 4) The configuration should satisfy ΔW=(Wb-Wa)≦40 μm (Equation 5). Here, T is the total thickness (including the thickness of the mesh and emulsion), ΔT is the step thickness from the printing surface, and ΔW is the step width on one side of the pattern opening 123a. Wb is the width dimension of the wide portion, and Wa is the width dimension of the narrow portion. The other configurations are the same as those of the first embodiment.

[0062] Next, a method for manufacturing the screen mask 120 according to this embodiment will be described with reference to Fig. 11. Fig. 11 is an explanatory diagram showing the method for manufacturing the screen mask 120. The method for manufacturing the screen mask 120 includes a layer forming step, a first patterning step, a second patterning step, and an etching step.

[0063] In the layer formation process, an emulsion layer is formed by applying an emulsion to a support material having pores that allow the application material to pass through. The emulsion is, for example, a photocurable resin, such as a liquid including polyvinyl alcohol (PVA), polyvinyl acetate (PVAc), silicone resin, acrylic resin, epoxy resin, etc.

[0064] First, in a state where the mesh 22 is attached to the frame 21 so as to be substantially flat, a coating process is carried out in which emulsion Pm1 is coated onto the mesh 22 as shown in ST1.

[0065] Next, a first patterning step is performed in which the emulsion layer is exposed to a predetermined first exposure pattern. For example, as shown in ST12, a first maskless exposure process is performed using a maskless exposure machine that does not use a photomask. Specifically, in a predetermined exposure pattern area, the front side of the emulsion layer is placed facing a light source such as an ultraviolet lamp or ultraviolet LED, and light is irradiated from the light source to illuminate the surface of the emulsion. The first exposure process hardens the portions of the emulsion irradiated with ultraviolet light corresponding to the exposure pattern area. The first exposed portions, which are the portions exposed by the first exposure process, form first emulsion hardened portions (first photo-crosslinked portions) Pa1 that harden with ultraviolet light. The portions other than the first exposed portions become first unhardened portions Pb1 in which the emulsion does not harden. The first unhardened portions Pb1 constitute first removal portions that will be removed in a later process and form part of the back side of the pattern opening 123a.

[0066] Next, as shown in ST13, a second maskless exposure process is performed using a maskless exposure machine that does not use a photomask. Specifically, in a predetermined second exposure pattern area, the front side of the emulsion Pm1 is placed facing a light source such as an ultraviolet lamp or ultraviolet LED, and light is irradiated from the light source to illuminate the surface of the emulsion Pm1. By the second exposure process, the portions of the emulsion Pm1 that are irradiated with ultraviolet light corresponding to the portions of the exposure pattern area are cured by the ultraviolet light. The second exposed portion, which is the portion exposed by the second exposure process, forms a second emulsion hardened portion (second photo-crosslinked portion) Pa2 that is hardened by ultraviolet light. The second unexposed portion, which is the portion excluding the second exposed portion, becomes a second unhardened portion Pb2 where the emulsion does not harden. The second unhardened portion Pb2 will be removed in a later process to form a second removal target portion that forms part of the printing surface side of the pattern opening 123a.

[0067] Both the first exposure process and the second exposure process are exposure processes in which light is irradiated from the printing surface side, and the second exposure process hardens a predetermined range by exposing from the same direction as the first exposure process, with a pattern that targets a wider area than the first exposure process, and with an output that has a deeper exposure depth.

[0068] Thereafter, in an etching process, the uncured portions Pb1 and Pb2 of the emulsion Pm1 are washed away with water or a solvent. This process forms pattern openings 123a that penetrate the emulsion Pm1 in the thickness direction from the front side to the back side and have guide portions 123e.

[0069] Next, a method for producing a printed matter by a screen printing method using the screen printing apparatus 10 according to this embodiment will be described with reference to Fig. 12. First, the front side of the screen mask 20 is placed facing the surface of the printing medium Ba held by the holding member 12.

[0070] Then, as shown in FIG. 12, a highly viscous paste-like coating material Pe is supplied from the rear surface side of the screen mask 20, that is, the surface opposite to the printing medium Ba, and the coating material Pe is filled into the pattern openings 23a.

[0071] Next, a squeegee 13 is placed on the back surface 20b of the screen mask 20, i.e., the surface opposite the printing surface. At this time, for example, the squeegee 13 is placed at a predetermined angle relative to the front surface of the printing medium Ba. Then, the squeegee 13 is moved at a predetermined speed while pressing the mesh 22 and the back surface of the mask film 23 toward the printing medium Ba with a predetermined printing pressure. The squeegee 13 presses against the mask film 23 over the entire back surface of the mask film 23. The pressure of the squeegee 13 causes the pressed portion of the mask film 23 to deform so that it is displaced toward the front surface and comes into contact with the printing medium Ba. The coating material Pe that the squeegee 13 has passed through is pushed out toward the printing medium Ba through the pattern openings 23a.

[0072] After the squeegee 13 has passed, the mask film 23 and mesh 22 deform to restore their original shape and separate from the print medium Ba, while some of the coating material Pe is transferred and remains on the print medium Ba, thereby printing a pattern on the print medium Ba and completing the print. At this time, part of the back side of the coating material Pe remains on the mask film 23 side. The coating material Pe can be made of various materials including, for example, metal and resin materials, and a variety of materials are used depending on the type of printing object, such as electronic components or displays.

[0073] According to the screen mask 120, screen printing apparatus 10, and screen printing method configured as described above, the pattern openings 123a are configured so that the rear portion thereof is larger toward the supply side than the front portion thereof in the direction of squeegee movement. As shown in Fig. 12, when the squeegee 13 is moved to supply the coating material, the coating material is guided from the supply side toward the printing surface side, ensuring discharge pressure and enabling high-precision printing. For example, Fig. 13 is an explanatory diagram showing the shapes of the screen mask 120 according to this embodiment and a screen mask 120A according to Comparative Example 2 and the effect of discharge pressure. Comparative Example 2 shows a symmetrical screen mask 120A having guide portions on both the front and rear sides in the direction of squeegee movement.

[0074] 13, the screen mask 120 according to this embodiment can prevent pressure from dispersing and escaping in the squeegee movement direction and ensure discharge pressure in the discharge direction, compared to the configuration of the screen mask 120A (Comparative Example 2) in which guide portions that are wider on the supply side than on the discharge side are formed on the side walls on both sides of the opening in the direction of squeegee movement. This ensures the discharge volume and discharge pressure, enabling high-precision printing.

[0075] Furthermore, the screen mask 120 according to the above embodiment is ΔW≦ΔT≦2 / 3T (Formula 4) By satisfying the above, deformation at the edge can be prevented and a desired printing pressure can be ensured.

[0076] 14, for example, if ΔW>ΔT, the mask film 23 is likely to deform and the print shape is likely to be distorted. On the other hand, if ΔT>2 / 3T, the effect of increasing the discharge pressure cannot be sufficiently obtained.

[0077] Furthermore, according to this embodiment, the first exposure process and the second exposure process are both exposure processes in which light is irradiated from the printing surface side, and by varying conditions such as the exposure amount and exposure time, it is possible to easily form pattern openings 123a having protruding guide portions 123e.

[0078] The present invention is not limited to the above-described embodiments, and in the implementation stage, the components can be modified and embodied without departing from the spirit of the invention.

[0079] For example, in the first embodiment, the pattern openings 23a have a constant opening width, but this is not limiting. For example, as another embodiment, the pattern openings 23a may be tapered so that the width on the printing surface side is narrower, as in the screen mask 220 shown in FIG.

[0080] As another embodiment, a screen mask 320 shown in FIG. 16 may be configured to have a step so that the printing surface side has a narrower width.

[0081] As another embodiment, as shown in FIG. 16 , a screen mask 420 may have an asymmetrical step shape in which a step with a narrower width on the printing surface side is provided on the rear side in the direction of squeegee movement. Alternatively, a configuration having an inclined surface instead of a step may be used. For example, only the rear side in the direction of squeegee movement may have an inclined surface with a narrower width on the printing surface, or if both sides are inclined surfaces, the rear side in the direction of squeegee movement may have an inclined surface with a larger inclination angle than the front side in the direction of squeegee movement.

[0082] Furthermore, in the second embodiment, a configuration having one step 123f is exemplified, but the number of steps is not limited to one. For example, as another embodiment, a configuration having two or more steps may be used as shown in Figure 17. In this case, it is preferable to satisfy formulas 6, 7, 8, 9, and 10. ΔW≦ΔT≦2 / 3T (Formula 6) ΔW=(Wb-Wa)≦40μm (Equation 7) ΔW n <ΔW (Equation 8) ΔW n ≦ΔT n ≦2 / 3T (Equation 9) ΔW n <ΔW (Equation 10) Here, T is the total thickness (including the thickness of the mesh and emulsion), ΔT is the step thickness from the printing surface, and ΔW is the step width on one side of the pattern opening 523a. Also, n may be plural.

[0083] In addition, in the above-described embodiment, a configuration having protrusions only on a portion thereof is illustrated, but the present invention is not limited to this. For example, as another embodiment, a method for manufacturing a screen mask 620 shown in FIG. 18 includes a first layer forming step, a first patterning step, a second layer forming step, a seasoning step, a second patterning step, and an etching step.

[0084] In the first layer forming step, a first emulsion Pm1 is applied to a support material having holes that allow the coating material to pass through, to form a first emulsion layer (ST21).

[0085] Next, a first patterning step is performed in which the first emulsion layer is exposed to a predetermined first exposure pattern. For example, as shown in ST22, a first maskless exposure process is performed using a maskless exposure machine that does not use a photomask. Specifically, in the predetermined exposure pattern area, the surface side of the base layer 623b is placed facing a light source such as an ultraviolet lamp or ultraviolet LED, and light is irradiated from the light source to illuminate the surface of the emulsion. The first exposed portions of the base layer 623b that are exposed by the first exposure process become first emulsion hardened portions (first photo-crosslinked portions) Pa1 that are hardened by ultraviolet light. On the other hand, the first non-exposed portions of the base layer 623b that are not the first exposed portions become unhardened portions Pb1 where the emulsion does not harden. The first unhardened portions Pb1 (first non-exposed portions) constitute first removal portions that will be removed in a later process to form the base opening.

[0086] Here, unlike the first exposure pattern and the second exposure pattern, in this embodiment, the second exposed portion overlaps with a part of the first exposed portion.

[0087] Next, as shown in ST23, a coating process is performed in which the second emulsion Pm2 is applied onto the base layer 623b, thereby forming a cover layer 623c from the second emulsion Pm2 on the printing surface side of the base layer 623b. Then, a seasoning process is performed in which the frame temperature is brought to approximately the same as that during the first maskless exposure process by leaving the frame to stand for about 3 hours under conditions for the maskless exposure process.

[0088] Next, a second patterning step is performed, in which the emulsion Pm2 is exposed to a second exposure pattern different from the first exposure pattern. That is, as shown in ST24, a second maskless exposure process is performed using a maskless exposure machine that does not use a photomask. Specifically, in a predetermined second exposure pattern area, the surface side of the emulsion Pm2 is placed facing a light source such as an ultraviolet lamp or ultraviolet LED, and light is irradiated from the light source to illuminate the surface of the emulsion Pm2. The second exposure process hardens the ultraviolet-irradiated portions of the emulsion Pm2 corresponding to the exposure pattern area. That is, the second exposed portions of the cover layer 23c that are exposed by the second exposure process form second emulsion-hardened portions (second photo-crosslinked portions) Pa2 that are hardened by the ultraviolet light. A portion of the second emulsion-hardened portion Pa2 forms the protrusion portion 623d, and the other portion forms the inner wall of the pattern opening 23a. Meanwhile, the second unexposed portions of the cover layer 23c, which are portions other than the second exposed portions, become second unhardened portions Pb2, in which the emulsion does not harden. The second uncured portion Pb2 includes a second portion to be removed, which will be removed in a later step to form the pattern opening 23a including the base opening.

[0089] Both the first and second exposure processes involve irradiating light from the printing surface side. The second exposure process hardens a predetermined area by exposing from the same direction as the first exposure process. In the second patterning process, a region including at least a portion of the first emulsion layer and at least a portion of the second emulsion layer is exposed by exposing with a second exposure pattern different from the first exposure pattern. That is, among the first non-exposed portions of the first emulsion layer that were not hardened in the first exposure process, the portion that forms the inner wall of the pattern opening 623a and the portion of the second emulsion layer that is on one side of the first exposed portion that was hardened in the first exposure process and forms the protrusion 623d at the edge of the pattern opening 623a are hardened by the second exposure process. Note that in this embodiment, a portion of the first exposed portion does not overlap with the second exposed portion, and there is a portion on the surface side of the base layer 623b where the cover layer 623c is not formed.

[0090] Thereafter, as an etching process, at least one side of the mask film is washed away with water or a solvent as shown in ST25. This process forms a pattern opening 623a that penetrates from the front side to the back side in the thickness direction as the uncured portions Pb1 and Pb2 of the emulsions Pm1 and Pm2 are washed away, and the portion where the first exposed portion and the second exposed portion overlap becomes a protrusion 623d, forming a step on the surface.

[0091] 18 shows an example of a screen mask 620 having pattern openings 23a and steps formed on one surface. That is, a convex portion that becomes protrusion 623d protruding to one side is formed on one surface in the second exposed portion of the second exposure step, and a recess 623g is formed in the portion where cover layer 623c is not formed, corresponding to the second non-exposed portion. Recess 623g serves as a relief portion that retreats to the side opposite the ejection direction, and can avoid interference with foreign matter or protrusions, for example, if there is a foreign matter, protrusion, or step such as an alignment mark on the side of a member that faces screen mask 620, such as a printing medium, during printing.

[0092] This screen mask and method for manufacturing the screen mask allow for highly accurate formation of steps with convex or concave portions in any desired location. For example, if there are foreign objects such as alignment marks, protrusions, or steps on the opposing surface of the screen mask, it is possible to form highly accurate recesses in those locations as escape areas that retreat to the side opposite the ejection direction, or to form convex portions at the edges of the openings with high accuracy, thereby ensuring the necessary printing pressure in the required locations. Therefore, a screen mask 620 with high printing accuracy can be provided.

[0093] In each of the above embodiments, when a first emulsion and a second emulsion are used, the first emulsion and the second emulsion may be made of different materials or may be made of the same material. In the above embodiment, the mesh 22 is attached to the frame 21 with the adhesive 24, and the mask film 23 is formed over the entire opening of the frame 21. However, the present invention is not limited to this. For example, a so-called combination type mesh may be used, and the mask film 23 may be formed only over a portion of the central part of the mesh 22.

[0094] In addition, the components illustrated in the above embodiments may be deleted, or the shape, structure, material, etc. of each component may be changed. Various inventions can be created by appropriately combining the multiple components disclosed in the above embodiments. By adjusting the dimensional ratio of the material, the difference in the lengthwise and widthwise elongation can be reduced, thereby improving printing accuracy. The following is a description equivalent to the invention described in the scope of the claims of the present application as originally filed: (1) a first layer forming step of forming a first emulsion layer by applying a first emulsion to a support material having holes that allow the coating material to pass through; a first patterning step of exposing the first emulsion layer with a predetermined first exposure pattern; a second layer forming step of overcoating a second emulsion on the first emulsion layer to form a second emulsion layer; a second patterning step of exposing the substrate with a second exposure pattern different from the first exposure pattern; and forming an opening in the first emulsion layer and the second emulsion layer by etching, and forming a step on one surface. (2) The second patterning step includes exposing an area including at least a part of the first emulsion layer and at least a part of the second emulsion layer from one side of the second emulsion layer, and The method for manufacturing a screen mask described in (1), wherein the exposed portion of the second exposure pattern includes at least a portion of the non-exposed portion in the first patterning process and at least a portion of the area on one side of the exposed portion in the first patterning process. (3) The method for manufacturing a screen mask described in (1), wherein the etching process forms an opening in the first emulsion layer and the second emulsion layer, and also forms a step on the surface on one side of the edge portion of the opening. (4) The method for manufacturing a screen mask according to any one of (1) to (3), wherein the exposure is maskless exposure. (5) The method for manufacturing a screen mask according to any one of (1) to (4), wherein the second emulsion layer is softer than the first emulsion layer. (6) a support material having holes that allow the coating material to pass through; a mask film formed on the support material, the mask film having a step portion or inclined surface in which the opening edge on the supply side opposite the printing surface is wider than the opening edge on the printing surface side, which is one side in the discharge direction of the coating material, and the mask film having a protrusion at the opening edge on the printing surface side that protrudes toward the printing surface side. (7) a support material having holes that allow the coating material to pass through; a mask membrane that is provided on the support material and has a pattern opening formed therein, the pattern opening having a wider opening edge on the supply side opposite the printing surface, which is one side in the direction of dispensing the coating material, than on the printing surface side, and the inner wall surface of the pattern opening is asymmetrically configured such that the opening edge is wider on one side in a predetermined first direction than on the other side. (8) The screen mask according to (7), wherein the mask film is enlarged toward the supply side at a rear end in the moving direction of the squeegee more than at a front end. (9) The screen mask according to (7) or (8), wherein the inner wall of the pattern opening of the mask film has an inclined surface. (10) The screen mask according to (7) or (8), wherein the inner wall of the pattern opening of the mask film has a step at a midpoint. [Explanation of symbols]

[0095] 10...screen printing device, 12...holding member, 13...squeegee, 13a...tip portion, 20, 20A, 120, 220, 320, 420...screen mask, 20a...surface, 20b...back side, 21...frame, 22...mesh, 22a...warp thread, 22b...weft thread, 22c...hole portion, 23...mask film, 23a...pattern opening, 23b...base layer, 23c...cover layer, 23d...protrusion portion, 24...adhesive, 120b...back side, 123...mask film, 123a...pattern opening, 123e...guide portion, 123f...step, Pa1...first emulsion hardened portion, Pa2...second emulsion hardened portion, Pb1...first unhardened portion, Pb2...second unhardened portion, Pm1...first emulsion, Pm2...second emulsion.

Claims

1. a first layer forming step of forming a first emulsion layer by applying a first emulsion to a support material having holes that allow the coating material to pass through; a first patterning step of exposing the first emulsion layer with a predetermined first exposure pattern; a second layer forming step of overcoating a second emulsion on one side of the first emulsion layer to form a second emulsion layer; a second patterning step of exposing the substrate with a second exposure pattern different from the first exposure pattern, performed after the first patterning step; an etching process for removing an uncured portion after the second patterning process; the exposure is a maskless exposure, the first exposure pattern is a pattern having an uncured portion that forms an opening wider than the width of the opening formed by the second exposure pattern, the cured portion of the second exposure pattern includes at least a portion of the uncured portion in the first patterning step and an area on the one side of at least a portion of the cured portion in the first patterning step; the second patterning step hardens a region including at least a part of the first emulsion layer and at least a part of the second emulsion layer from one side of the second emulsion layer, and the second patterning step hardens a portion of the unhardened portion of the first emulsion layer that is not hardened in the first patterning step, which constitutes an inner wall of the opening, and a portion of the second emulsion layer on one side of the hardened portion that is hardened in the first patterning step, which will become a protrusion at the edge of the opening; in the etching treatment, unhardened portions of the first emulsion and the second emulsion are removed to form openings in the first emulsion layer and the second emulsion layer; forming a protrusion formed of a part of the second emulsion layer on the edge of the opening on the surface on one side; A method for manufacturing a screen mask.

2. 2. The method for manufacturing a screen mask according to claim 1, wherein the second emulsion layer is softer than the first emulsion layer.

3. The method for manufacturing a screen mask according to claim 1 , wherein the protrusions and surface layer portions of the inner wall surfaces of the openings connected to the protrusions are made of the second emulsion layer.

4. 2. The method for manufacturing a screen mask according to claim 1, wherein the opening is a linear slit opening that penetrates a mask film comprising the first emulsion layer and the second emulsion layer stacked on one side of the first emulsion layer from one side to the other in the thickness direction.

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