Dry film laminate, screen mask, and method for manufacturing screen mask

Abstract

To provide a dry film laminate, a screen mask, and a method for manufacturing the screen mask which are capable of improving handleability.SOLUTION: The dry film laminate according to one embodiment includes a base film member, a cover emulsion layer laminated on one side of the base film, a base emulsion layer laminated on one side of the cover emulsion layer, and a cover film member laminated on one side of the base emulsion layer. The cover emulsion layer is composed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curable resin, a photoinitiator and a silicone compound. The base emulsion layer is composed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curable resin and a photoinitiator.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a dry film laminate, a screen mask, and a method for manufacturing a screen mask. Regarding. [Background technology]

[0002] Screen printing, which is one of the printing techniques, is a method of forming an arbitrary print on a substrate by using a screen mask having a predetermined pattern opening formed of a resin composition on a mesh substrate. This screen printing method is used for various printing such as printing of wiring, electrodes, fluorescent materials, etc., and is used in various fields including electronic parts.

[0003] For example, a screen mask includes a mesh having holes through which a coating material can pass, and a mask film having a pattern opening provided in the mesh. The pattern opening formed in the mask film has a shape corresponding to, for example, a printing pattern and a predetermined width. For example, after an emulsion forming a mask film is applied to the mesh, the pattern opening is formed by exposure processing. In such a screen mask, a method of forming a mask film on a mesh includes a method of applying a photosensitive resin layer by layer using a coating tool called a bucket, and repeating the application until a predetermined thickness is reached, but it takes time to adjust the thickness and the thickness is likely to become uneven. In addition, a photomask may be used during exposure, but the photomask placed during exposure or the medium during printing may adhere to the surface of the mask film and become difficult to peel off, so there is a demand for improving the handleability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-129954 A Summary of the Invention [Problem to be solved by the invention]

[0005] For such a screen mask, there is a demand for a dry film laminate, a screen mask, and a method for manufacturing a screen mask that can improve the handleability. [Means for solving the problem]

[0006] A dry film laminate according to one embodiment comprises a base film member, a cover emulsion layer laminated on one side of the base film, a base emulsion layer laminated on one side of the cover emulsion layer, and a cover film member laminated on one side of the base emulsion layer, wherein the cover emulsion layer is composed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, a photoinitiator, and a silicone compound, and the base emulsion layer is composed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, and a photoinitiator. Effect of the Invention

[0007] According to the embodiments of the present invention, it is possible to provide a dry film laminate, a screen mask, and a method for manufacturing a screen mask, which can improve the handleability. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view of a screen printing apparatus according to first and second embodiments. [Diagram 2] FIG. [Diagram 3] FIG. 2 is an explanatory diagram showing the configuration of a DFR laminate member of the screen mask according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing the change in silicone concentration in the depth direction of the DFR laminated member according to the embodiment. [Diagram 5] FIG. 2 is an explanatory diagram showing a method for producing the DFR laminate member according to the embodiment. [Figure 6] FIG. 2 is an explanatory diagram showing a method for producing the DFR laminate member according to the embodiment. [Figure 7]3A to 3C are explanatory diagrams showing a method of manufacturing the screen mask according to the embodiment. [Figure 8] 3A to 3C are explanatory diagrams showing a method of manufacturing the screen mask according to the embodiment. [Figure 9] FIG. 2 is an explanatory diagram showing a coating method for a DFR laminated member according to the embodiment. [Figure 10] FIG. 11 is an explanatory diagram showing the relationship between the content of the diazo compound in the mask film and the thickness of the base layer according to the second embodiment. [Figure 11] 13A and 13B are explanatory views of a mask film according to Example 1 and Example 2 of the second embodiment. [Figure 12] FIG. 4 is an explanatory diagram showing the configuration of a mask film according to the first and second embodiments. [Figure 13] FIG. 11 is an explanatory diagram showing the PVA content and the monomer content in a mask film according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] Hereinafter, a screen printing apparatus 10 and a screen mask 20 according to a first embodiment of the present invention will be described with reference to Figs. 1 to 5. Fig. 1 is a plan view showing the screen printing apparatus 10 according to this embodiment, and Fig. 2 is a cross-sectional view. Fig. 3 is an explanatory diagram showing the configuration of a DFR laminated member 230A, and Fig. 4 is an explanatory diagram showing the change in silicone concentration in the depth direction of the DFR laminated member according to the embodiment. Figs. 5 and 6 are explanatory diagrams showing a manufacturing method of a DFR laminated member 230A. Figs. 7 and 8 are explanatory diagrams showing a manufacturing method of a screen mask. Note that in each figure, the configuration is appropriately enlarged, reduced, or omitted for the purpose of explanation. In the figures, arrows X, Y, and Z respectively indicate three directions perpendicular to each other. As an example, the Z axis in the figures will be described as being along the thickness direction and depth direction.

[0010] As shown in FIG. 1, the screen printing apparatus 10 includes a screen mask 20, a squeegee 13 configured to be movable while in contact with the back surface (other surface) opposite the printing surface of the screen mask 20, a moving unit for moving the squeegee 13, and a support unit for supporting the screen mask 20 opposite the printing medium B.

[0011] The screen printing apparatus 10 forms various printing materials in a predetermined pattern on the surface of a printing medium. For example, the screen printing apparatus 10 is used in the manufacture of chip components (capacitors, chip resistors, inductors, thermistors, etc.), touch panels, liquid crystal display (LCD) seals, LTCC (Low Temperature Co-fired ceramics) substrates, solar cell electrodes, and other electronic components.

[0012] 1 to 3, the screen mask 20 includes a frame 21, a mesh 22 which is a base material (support material) stretched over the frame 21, and a mask film 23 formed on the mesh 22. In the screen mask 20, the side which faces the surface of the printing medium B supported by the support 12 during printing is called the front side, and the opposite side to which the coating material Pe is supplied is called the back side.

[0013] The frame 21 has two pairs of parallel edges 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. As an example, in this embodiment, a frame 21 with an opening dimension of 275 mm in the Y direction and 275 mm in the X direction is used.

[0014] The frame 21 also functions as a frame for holding a predetermined amount of coating material on the rear surface side of the mask film 23. The frame 21 and the mesh 22 are joined at their joints by, for example, a synthetic rubber-based or cyanoacrylate-based adhesive.

[0015] The mesh 22 is a woven fabric formed by weaving warp threads 22a and weft threads 22b, and has a large number of holes 22c that are open to allow the coating material to pass through. The warp threads 22a and weft threads 22b are wires or fibers made of metal such as stainless steel or resin such as polyester. The warp threads 22a and weft threads 22b each extend obliquely with respect to the moving direction (first direction) of the squeegee 13, for example.

[0016] A mask film 23 having a predetermined pattern opening 24 is formed on the mesh 22. That is, the mesh 22 holds the mask film 23 in the open portion of the frame 21.

[0017] The mask film 23 has a dry film resist 230 as a dry film laminate having a laminated structure.

[0018] Specifically, the mask film 23 includes a base coat layer 231 applied to the mesh 22 and a dry film resist 230 attached onto the base coat layer 231 .

[0019] The base coat layer 231 is composed of at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, and a photoinitiator. The base coat layer 231 is a resin layer of a predetermined thickness that adheres closely to the mesh 22 by applying a liquid base coat material 231a to the mesh 22 before applying the dry film resist 230, and applying the dry film resist 230 before the base coat material 231a dries and drying it.

[0020] The dry film resist 230 is a laminated body having a plurality of resin layers, and is formed into a sheet shape by drying a plurality of liquid emulsions. The dry film resist 230 is configured as a two-layer structure of a base emulsion layer 233 and a cover emulsion layer 234. As an example, before being attached to the mesh 22, the dry film resist 230 is configured as a DFR (dry film resist) laminated member 230A configured by laminating a base film 232 (base film member), a cover emulsion layer 234, a base emulsion layer 233, and a cover film 235 (cover film member) in order in the thickness direction. The cover film 235 is peeled off just before the DFR laminated member 230A is attached to the mesh 22, and the base film 232 is peeled off after the attachment, so that the two-layered dry film resist 230 is provided on the mesh 22.

[0021] The base film 232 is a film member made of, for example, PET in a sheet shape. For example, the thickness of the base film 232 is 50 μm to 125 μm.

[0022] The cover film 235 is a film member formed in a sheet shape from, for example, PE. The thickness of the cover film 235 is, for example, 10 to 30 μm.

[0023] The base emulsion layer 233 is a resin layer formed from an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet-curing resin, and a photoinitiator.

[0024] The cover emulsion layer 234 is a resin layer formed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, a photoinitiator, and a silicone compound (silicone).

[0025] Examples of ultraviolet-curing resins include the KAYARAD series manufactured by Nippon Kayaku and the UV series manufactured by Mitsubishi Chemical.

[0026] Examples of the photoinitiator include the KAYACURE series manufactured by Nippon Kayaku Co., Ltd., the Nikkacure series manufactured by Nippon Chemical Industry Co., Ltd., and the Adeka Arcles series manufactured by ADEKA.

[0027] The silicone compound content (wt %) of the cover emulsion layer 234 is higher than that of the base emulsion layer 233. The silicone compound content of the cover emulsion layer 234 is 0.1 to 10% by weight.

[0028] In the dry film resist 230, the content of the silicone compound changes continuously at the boundary between the base emulsion layer 233 and the cover emulsion layer 234. That is, as the position in the depth direction from the surface of the cover emulsion layer 234 increases, the content of the silicone compound gradually decreases, forming a curve with an inflection point.

[0029] 4 is a graph showing the change in silicone concentration in the depth direction of the DFR laminate member, showing that the silicone concentration at the boundary between the first and second layers changes continuously. The concentration here refers to the weight of the silicone component contained relative to the weight of the solid content of the formed film. The vertical axis shows the silicone concentration (%), and the horizontal axis shows the position (μm) in the thickness direction (depth direction) of the dry film resist 230 from the surface on the cover emulsion layer 234 side.

[0030] The thickness (thickness), which is the dimension in the stacking direction of the mask film 23, is set to, for example, 10 μm to 100 μm. For example, in the mask film 23, the thickness of the cover emulsion layer 234 is smaller than the thickness of the base emulsion layer 233. As one example, the thickness of the cover emulsion layer 234 is set to 1% to 40% of the thickness of the base emulsion layer 233. For example, in this embodiment, the thickness of the base emulsion layer 233, which is the main emulsion, is set to 3 μm to 100 μm, and the thickness of the cover emulsion layer 234, which is the cover coat layer, is set to 0.5 μm to 5 μm.

[0031] For example, when the thicknesses of the emulsion layers 233, 234 are at their minimum, the DFR laminate member 230A is configured such that the base film 232 is 75 μm, the base emulsion layer 233 is 3 μm, the cover emulsion layer 234 is 0.5 μm, and the cover film 235 is 25 μm; when the thicknesses of the emulsion layers 233, 234 are at their maximum, the base film 232 is 75 μm, the base emulsion layer 233 is 100 μm, the cover emulsion layer 234 is 5 μm, and the cover film 235 is 25 μm.

[0032] The mask film 23 is formed on a mesh 22 that is disposed in the opening portion of the frame 21. A predetermined pattern opening 24 for printing is formed in the mask film 23 by exposure.

[0033] Furthermore, the mask film 23 may have steps such as recesses in addition to the pattern openings 24 which are through holes.

[0034] The minimum opening width of the pattern opening 24, i.e., the width dimension of the opening at the narrowest part of the pattern opening 24, is 30 μm or less. Here, as an example, the dimension at the surface of the mask film 23, i.e., the surface facing the printing medium B, is used as the standard.

[0035] The pattern opening 24 is a pattern hole having a shape corresponding to the printing pattern, and penetrates the mask film 23 in the thickness direction (depth direction). For example, the pattern opening 24 is configured by combining slits, etc. The pattern opening 24 is configured to be able to hold a coating material. The shape of the printing pattern can be set appropriately. As an example, in this embodiment, the pattern shape has a plurality of identical pattern units arranged in a matrix.

[0036] The mask film 23 constitutes a printed portion where no photosensitive resin is present in the pattern openings 24, and thus the pattern openings 24 pass through the holes of the mesh 22, allowing the coating material to pass from the back surface to the front surface. The areas of the mask film 23 other than the pattern openings 24, where the holes of the mesh 22 are blocked with photosensitive resin, constitute non-printed portions that do not allow ink as a coating material to pass through.

[0037] 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 the pressing force of the squeegee 13 arranged on the back surface side, which is the upper side in Fig. 2, and is restored to its original state when the pressing force is released. With the coating material held in the pattern openings 24 of the mask film 23, the mask film 23 comes into contact with and separates from the printing medium B due to the elastic deformation of the mesh 22 and the mask film 23, and the coating material Pe is transferred from the pattern openings 24 to the printing medium B arranged opposite the printing surface side of the mask film 23.

[0038] The squeegee 13 is made of, for example, urethane rubber, silicone rubber, synthetic rubber, metal, plastic, or other material, and is formed, for example, in a thin plate shape. For example, the squeegee 13 is chamfered so that the thickness of the tip is reduced. The squeegee 13 is configured to be movable relative to the frame 21. For example, the squeegee 13 has a length that covers the entire length of the area of ​​the mask film 23 in a direction perpendicular to the movement direction. The tip portion of the squeegee 13 abuts against the back surface of the screen mask 20 and is pressed against the front surface, and moves in the movement direction along the arrow in FIG. 1 to press the entire surface of the mask film 23 and push the coating material Pe to the front surface from the pattern openings 24 in which the coating material has been previously filled.

[0039] Next, a method for manufacturing the screen mask 20 according to this embodiment will be described with reference to Fig. 5 to Fig. 8. Fig. 5 and Fig. 6 are explanatory diagrams showing a method for manufacturing the DFR laminate member 230A. Fig. 7 and Fig. 8 are explanatory diagrams showing a method for manufacturing the screen mask 20.

[0040] First, a description will be given of a method for producing the DFR laminated member 230A. The manufacturing process for the DFR laminated member 230A includes a first coating process ST11, a first drying process ST12, a first winding process ST13, a second coating process ST14, a second drying process ST15, and a second winding process ST16.

[0041] First, prior to ST11, a cover coating agent 234a is prepared as a first emulsion. Specifically, an emulsion containing polyvinyl alcohol, a diazo compound, an ultraviolet curing monomer, a photopolymerization initiator, and a silicone compound is mixed to a solid content ratio of 15% and a viscosity of 600 mPa·s to prepare the cover coating agent. The liquid emulsion is adjusted so that the silicone compound in the solid content is 0.1 to 10 wt% (preferably 0.3 to 1.0 wt%).

[0042] In ST11, a first coating process is performed to coat the cover coating agent 234a on the base film 232. As a coating method, various methods such as offset gravure, gravure, and slot die can be used, and as an example, a gravure method is used.

[0043] 5, while a base film 232, which is a sheet material wound in advance into a roll, is unwound and conveyed along a predetermined conveying path, a liquid cover coat material 234a contained in a first tank 73 is supplied to the base film 232 by a first application head 74, and rubbed and applied thereon. At this time, the thickness is set so that the thickness after drying is 0.5 to 5.0 μm, preferably 1.0 to 2.0 μm. In ST12, the cover coat agent 234a is dried. Specifically, as shown in Fig. 5, the base film 232 on which the cover coat 234a is applied is sent into the first drying furnace 72 and is allowed to pass through the drying furnace 72 for a predetermined period of time.

[0044] At this time, the drying time can be adjusted by the coating speed and the length L1 of the drying area. For example, in a drying area of ​​10 m, the coating speed can be set to 5 m / min, and drying can be performed for about 120 seconds.

[0045] The liquid cover coating agent 234 a is hardened by the drying process in ST 12 , and a cover emulsion layer 234 is formed on the base film 232 .

[0046] Then, in ST13, the laminate 234A in which the cover emulsion layer 234 is formed on the dried base film 232 is wound into a roll.

[0047] Next, steps ST14 to ST16 will be described with reference to FIG.

[0048] First, prior to ST14, a base agent 233a is prepared as a second emulsion to be applied as a second layer. For example, an emulsion containing polyvinyl alcohol, a diazo compound, an ultraviolet curing monomer, and a photopolymerization initiator is mixed to a solid content ratio of 25 to 30% and a viscosity of 1350 mPa s.

[0049] In ST14, a second coating process is performed to coat the base agent 233a onto the cover emulsion layer 234. Various coating methods can be used, such as gravure, slot die, knife coater, comma coater, roll coater, etc. As an example, coating is performed using a slot die.

[0050] 6, a laminate of a cover emulsion layer 234 and a base film 232 wound in a roll is unwound and transported along a predetermined transport path, while a liquid base material 233a contained in a second tank 76 is supplied and applied onto the cover emulsion layer 234 by a slot die head 77. At this time, the thickness is set so that the thickness after drying is 3 to 100 μm, preferably 5 to 75 μm.

[0051] Subsequently, in ST15, the base agent 233a is dried. Specifically, as shown in Fig. 6, the base film 232 on which the base agent 233a is applied is sent into a drying oven 78 and is allowed to pass through the drying oven 78 for a predetermined time.

[0052] At this time, the drying time can be adjusted by the coating speed and length L2. For example, a drying area of ​​10 m can be set at 2 m / min and dried for about 300 seconds.

[0053] The liquid base agent 233a hardens by the drying process in ST15, and a laminate in which the cover emulsion layer 234 and the base layer 233 are laminated on the base film 232 is formed.

[0054] Next, in ST16, the laminate in which the cover emulsion layer 234 and the base layer 233 are laminated on the base film 232 is overlapped with the cover film 235 and wound into a roll. At this time, the cover film 235 is wound and rolled so as to face and overlap the base emulsion layer 233. Then, by cutting at predetermined lengths, the DFR laminated member 230A wound into a roll is completed.

[0055] Next, a method for manufacturing the screen mask 20 will be described with reference to FIGS.

[0056] The manufacturing method of the screen mask 20 in this embodiment includes a base film forming process ST21 of forming a base coat layer on the mesh 22, a bonding process ST22 (DFR bonding process) of bonding a dry film resist 230 onto the base coat layer, a drying process ST23 of drying the dry film resist 230, an exposure process ST24, and a development process ST25.

[0057] First, in ST21, a base coat layer 231 is formed on the mesh 22. Specifically, a bucket is used to apply a base coat material 231a from one end side to the other end side.

[0058] Next, in ST22, a dry film resist 230 is attached to the mesh 22 on which the liquid base coat material 231a has been formed. Specifically, the cover film 235 of a previously prepared DFR laminated member 230A is peeled off, and the exposed base emulsion layer 233 side is attached in a direction to be disposed opposite to the base coat layer 231a.

[0059] After the attachment, the base film 232 is peeled off, so that the two-layered dry film resist 230 is formed on the mesh 22 .

[0060] Next, in ST23, the substrate is placed in a drying chamber 79 and dried. As a result, the dry film resist 230 and the base coat layer 231 are solidified, and the mask film 23 is formed.

[0061] Next, in ST24, an exposure process is performed. The exposure process is an exposure process in which light is irradiated from the printed surface side, and the area corresponding to the exposure pattern is hardened by exposing with a predetermined pattern. As the exposure process, a photomask M having a predetermined pattern is placed on top of the dry film resist 230, and an exposure process in which light is irradiated from the printed surface side is performed. Specifically, an exposure process is performed in which the front side of the dry film is placed facing an irradiation head such as an ultraviolet lamp or ultraviolet LED in a predetermined exposure pattern area, and light is irradiated from the irradiation head to illuminate the surface of the dry film resist 230.

[0062] For example, in ST24, in a predetermined exposure pattern region, the front side of the DFR is placed facing an illumination such as an ultraviolet lamp or ultraviolet LED, and light is irradiated from the illumination to illuminate the surface of the emulsion, performing an exposure process. For example, the portion of the surface of the DFR that is exposed by the exposure process becomes a cured portion Pa that is cured by ultraviolet light, and the portion that is not exposed becomes an uncured portion Pb where the emulsion is not cured, and the first uncured portion Pb (unexposed portion) constitutes a removal target portion that will be removed in a later process to form the opening 24. That is, in this embodiment, in the patterning process, the portion that will become the pattern opening 24 is the uncured portion Pb, and the other region is the cured portion Pa. Note that, depending on the emulsion, the exposed portion may be uncured and the unexposed portion may be the cured portion, and the exposed portion may be the portion to be removed by etching.

[0063] Subsequently, in a development process ST25, at least one side of the mask film 23 is washed away with water or a solvent. By this process, the uncured portion Pb of the emulsion is washed away, and an opening 24 penetrating from the front side to the back side in the thickness direction is formed.

[0064] Next, a method for producing a printed matter by a screen printing method using the screen printing apparatus 10 according to the present embodiment will be described with reference to Fig. 1 and Fig. 2. First, the front side of the screen mask 20 is placed facing the front surface of the print medium B. At this time, the screen mask 20 is positioned by a positioning member such as a positioning pin, for example.

[0065] Then, 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 print medium B, and the coating material is filled into the pattern openings .

[0066] Next, the squeegee 13 is placed on the back surface of the screen mask 20, i.e., the surface opposite to the printing surface side. At this time, for example, the squeegee 13 is placed at a predetermined angle inclined with respect to the front surface of the printing medium B. 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 B with a predetermined printing pressure. The squeegee 13 presses the mask film 23 in an area covering the entire back surface of the mask film 23. The pressure of the squeegee 13 causes the mask film 23 to deform so that the pressed portion is displaced toward the front side and comes into contact with the printing medium B. The coating material Pe pressed by the passage of the squeegee 13 is pushed out from the pattern opening 24 toward the printing medium B side.

[0067] After the squeegee 13 has passed, the mask film 23 and mesh 22 deform so as to restore their original shape and are separated from the print medium B, and a portion of the coating material Pe is transferred and remains on the print medium B, thereby printing a pattern on the print medium B and completing the print. At this time, a portion of the back side of the coating material Pe may remain on the mask film 23 side. The coating material Pe is various materials including, for example, metal materials and resin materials, and various materials are used depending on the type of printing object, for example, electronic components, displays, etc.

[0068] In the screen mask 20 configured as described above, the cover emulsion layer 234, which is a cover coat layer, is formed on the base emulsion layer 233, which is the main emulsion, and the silicone compound contained in the cover emulsion layer 234 has releasability. This makes it easy to peel the photomask M from the screen mask 20 after exposure, and also prevents adhesion to the printing medium B, such as a substrate, during printing, reducing printing bleeding.

[0069] In addition, since the mask film 23 is formed by attaching the dry film resist 230 to the mesh 22, thickness adjustment is easy. That is, by applying a plurality of types of 230 with different thicknesses with high precision in advance, selecting the thickness of the dry film resist 230 according to the specifications of the screen mask, and attaching it to the mesh, the thickness can be easily adjusted, time can be shortened, and foreign matter is less likely to be mixed in, compared to a method of repeatedly applying it with an application tool (bucket). In addition, it is less susceptible to the influence of the unevenness of the mesh 22, and smoothness can be improved. Furthermore, the use of the dry film resist 230 provides good linearity of the pattern and is less susceptible to damage. Therefore, when printing is repeated, physical damage to the pattern edge portion can be prevented.

[0070] In the above embodiment, the base film 232 and the cover film 235 are provided as film members in advance, and the base film 232 is attached to the mesh 22 and dried, so that the smoothness of the base film 232 is maintained even after drying. Therefore, the smoothness is maintained even after the base film 232 is peeled off, and a screen mask 20 with good smoothness can be manufactured. In addition, since the cover emulsion layer 234 contains silicone, friction with the printing medium B during screen printing is reduced, and durability during printing is improved. In addition, the stickiness of the surface can be prevented during pattern exposure using the photomask M, and more precise patterning is possible. Furthermore, since the surface contains a silicone compound, it has water and oil repellency, so that it is less likely to be damaged when cleaning the screen mask with a solvent or the like, and it can be dried quickly.

[0071] That is, in a screen mask, different properties such as surface stickiness prevention, printing durability, and high resolution are required, and adding a silicone compound is effective in many cases for stickiness prevention and high resolution. However, adding silicone is a factor that deteriorates resolution, and if the amount of silicone increases and the amount of photosensitive resin decreases, the resolution during pattern formation decreases. Therefore, in the screen mask according to the above embodiment, by adding a silicone compound only to the layer that constitutes the surface on the screen printing side, stickiness prevention and printing durability are ensured, and the base emulsion part (base emulsion layer 233) is configured to have a two-layer DFR with no silicone compound added in order to emphasize high resolution, and different properties can be achieved at the same time.

[0072] [Second embodiment] Hereinafter, the mask film 23A according to the second embodiment will be described with reference to FIGS.

[0073] In the mask film 23A according to this embodiment, the cover layer 234 contains a fluorine compound, and the weight ratio of the fluorine compound contained in the cover layer 234 is greater than the weight ratio of the silicone compound. The amount of the diazo compound contained in the cover layer 234 is equal to or greater than the amount of the diazo compound contained in the base layer 233, and the emulsion of the cover layer 234 is made of a material softer than the emulsion of the base layer 233. The amount of PVA in the cover layer 234 is greater than the amount of monomer, while the amount of PVA in the base layer 233 is less than the amount of monomer. Other configurations are the same as those of the mask film 23, so duplicated explanations will be omitted.

[0074] The mask film 23A has a dry film resist 230 as a dry film laminate having a laminated structure.

[0075] Specifically, the mask film 23A includes a base coat layer 231 applied to the mesh 22 and a dry film resist 230 attached onto the base coat layer 231.

[0076] The base coat layer 231 is composed of at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, and a photoinitiator. The base coat layer 231 is a resin layer of a predetermined thickness that adheres closely to the mesh 22 by applying a liquid base coat material 231a to the mesh 22 before applying the dry film resist 230, and applying the dry film resist 230 before the base coat material 231a dries and drying it.

[0077] The dry film resist 230 is a laminated body having a plurality of resin layers, and is formed into a sheet shape by drying a plurality of liquid emulsions. The dry film resist 230 is configured as a two-layer structure of a base emulsion layer 233 and a cover emulsion layer 234. As an example, before being attached to the mesh 22, the dry film resist 230 is configured as a DFR (dry film resist) laminated member 230A configured by laminating a base film 232 (base film member), a cover emulsion layer 234, a base emulsion layer 233, and a cover film 235 (cover film member) in this order. The cover film 235 is peeled off just before the DFR laminated member 230A is attached to the mesh 22, and the base film 232 is peeled off after the attachment, so that the two-layered dry film resist 230 is provided on the mesh 22.

[0078] The base film 232 is a film member made of, for example, PET in a sheet shape. For example, the thickness of the base film 232 is 50 μm to 125 μm.

[0079] The cover film 235 is a film member formed in a sheet shape from, for example, PE. The thickness of the cover film 235 is, for example, 10 to 30 μm.

[0080] The base emulsion layer 233 is a resin layer formed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, and a photoinitiator. For example, the base layer 233 does not contain a fluorine compound.

[0081] The cover emulsion layer 234 is a resin layer formed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, a photoinitiator, and a silicone compound (silicone). The cover emulsion layer 234 also contains a fluorine compound. Here, the content in the cover emulsion layer 234 is, in weight %, fluorine compound>silicone compound. As an example, the content in the cover emulsion layer 234 is, in weight %, fluorine-based:silicone-based=2:1.

[0082] Examples of ultraviolet-curing resins include the KAYARAD series manufactured by Nippon Kayaku and the UV series manufactured by Mitsubishi Chemical.

[0083] Examples of the photoinitiator include the KAYACURE series manufactured by Nippon Kayaku Co., Ltd., the Nikkacure series manufactured by Nippon Chemical Industry Co., Ltd., and the Adeka Arcles series manufactured by ADEKA.

[0084] The silicone compound content (wt %) of the cover emulsion layer 234 is higher than that of the base emulsion layer 233. The silicone compound content of the cover emulsion layer 234 is 0.1 to 10% by weight.

[0085] In the dry film resist 230, the content of the silicone compound changes continuously at the boundary between the base emulsion layer 233 and the cover emulsion layer 234. That is, as the position in the depth direction from the surface of the cover emulsion layer 234 increases, the content of the silicone compound gradually decreases, forming a curve with an inflection point.

[0086] The thickness of the mask film 23A, which is the dimension in the stacking direction, is set to, for example, 10 μm to 100 μm. For example, in the mask film 23A, the thickness of the cover emulsion layer 234 is smaller than the thickness of the base emulsion layer 233. As one example, the thickness of the cover emulsion layer 234 is set to 1% to 40% of the thickness of the base emulsion layer 233. For example, in this embodiment, the thickness of the base emulsion layer 233, which is the main emulsion, is set to 3 μm to 100 μm, and the thickness of the cover emulsion layer 234, which is the cover coat layer, is set to 0.5 μm to 5 μm.

[0087] For example, when the thicknesses of the emulsion layers 233, 234 are at their minimum, the DFR laminate member 230A is configured such that the base film 232 is 75 μm, the base emulsion layer 233 is 3 μm, the cover emulsion layer 234 is 0.5 μm, and the cover film 235 is 25 μm; when the thicknesses of the emulsion layers 233, 234 are at their maximum, the base film 232 is 75 μm, the base emulsion layer 233 is 100 μm, the cover emulsion layer 234 is 5 μm, and the cover film 235 is 25 μm.

[0088] In the present embodiment, the mask film 23A preferably has a diazonium compound content in the cover layer 234≧the diazonium compound content in the base layer 233 in terms of weight percent. FIG. 10 is an explanatory diagram showing the relationship between the content of the diazo compound and the thickness of the base layer 233 for two examples 1 and 2, which are different in the content of the diazonium compound, in the mask film 23A according to the present embodiment.

[0089] In Example 1, the base layer had a thickness of 20 μm and contained 3 wt % of the diazonium compound, and the cover layer had a thickness of 1.5 μm and contained 4 wt % of the diazonium compound. In Example 2, the base layer had a thickness of 40 μm and contained 2 wt % of the diazonium compound, and the cover layer had a thickness of 1.5 μm and contained 4 wt % of the diazonium compound.

[0090] In addition, as for the relationship between the amount of diazonium compound and the hardening of the emulsion, when the thickness of the emulsion is thick, the less the diazonium compound, the easier it is for the back to harden. For example, when the content of diazonium compound is high, the diazonium compound at the back, which is far from the light source of the exposure, cannot receive light, so the emulsion at the back is difficult to solidify. On the other hand, when the content of diazonium compound is low, the diazonium compound at the back of the exposure can also receive light, so the entire emulsion is easy to harden.

[0091] Here, FIG. 11 shows a graph of how the diazo solidifies when the mask film 23A is made into two layers. In the graph of FIG. 11, the horizontal axis indicates the dimension in the thickness direction, and the vertical axis indicates the degree of hardening. FIG. 11 shows a graph comparing the degree of hardening for Example 1 in which the diazo content of the cover layer 234 is 4 wt% and the diazo content of the base layer 233 is 3 wt%, and Example 2 in which the diazo content of the cover layer 234 is 4 wt% and the diazo content of the base layer 233 is 2 wt%. According to FIG. 11, it can be seen that when the emulsion of the base layer 233 is thick, by reducing the amount of diazonium, the emulsion is more likely to solidify deep inside.

[0092] Regarding the cover layer 234, the relationship between thickness and the amount of the diazonium compound is preferably 2.5 to 4.5 wt % for a thickness of 1 to 2 μm, and 3.5 to 5.5 wt % for a thickness of 1 μm or less.

[0093] FIG. 12 shows the wt % of the liquid emulsion in the cover layer 234 and the base layer 233 in the dried state (DFR state) for Examples 1 and 2.

[0094] Since the cover layer 234 is thinner than the base layer 233, it needs to be firmly solidified, and the diazonium content is set to 4 wt%. On the other hand, the content of the diazonium compound in the base layer 233 is set to 3 wt% or 2 wt% depending on the thickness, and the content is set to the content corresponding to the thickness. For example, the thickness (μm) x diazonium content (wt%) of the base layer 233 is set to 120 or less.

[0095] 13, in the mask film 23A, the PVA content in the base layer 233 is less than the monomer content, that is, the base layer 233 contains a large amount of monomer since the resolution is important.

[0096] On the other hand, it is preferable that the PVA content is greater than the monomer content in the cover layer 234. For example, since the cover layer 234 constitutes the surface of the screen plate, by increasing the PVA content, it is possible to ensure extensibility and printing durability.

[0097] In this embodiment, the emulsion of the cover layer 234 constituting the mask membrane 23 is made of a material that is softer than the emulsion of the base layer 233. The softness is measured by forming the emulsion of the cover layer and the base layer into a film separately, exposing the film, and then stretching each film with a tensile tester to measure the amount of elongation until it breaks. The film with the larger amount of elongation is judged to be softer. The thickness of the film is preferably 30 to 50 μm. The other configurations are similar to those of the mask film 23 in the first embodiment.

[0098] According to this embodiment, the cover layer contains a fluorine compound, which makes it less susceptible to cleaning and makes it easier to peel off the photomask from the emulsion surface after exposure. Therefore, the effect of the paste of the printed matter being less likely to reattach to the plate is obtained. In addition, a fluorine compound has a greater water- and oil-repellent effect with a smaller amount than a silicone compound, and if the amount of the fluorine compound in the entire mask film (DFR) is too large, the repellency becomes too large when producing the DFR, which is not preferable. Fluorine compounds have excellent durability, and fluorine compounds repel water and oil, but silicone compounds only repel water. On the other hand, silicone compounds have excellent flexibility. Therefore, in this embodiment, the cover layer is mainly composed of a fluorine compound, so that the advantages of the fluorine compound can be utilized.

[0099] In addition, by adjusting the diazonium compound according to the thickness, it is possible to improve exposure performance by allowing light to reach the back of the emulsion. Therefore, when the overall emulsion thickness is thick, reducing the content of the diazonium compound allows light to reach the back of the emulsion, increasing the inner thickness of the emulsion and shortening the exposure time.

[0100] The configuration and arrangement of the pattern openings 24 are not limited to those described above, and can be changed as appropriate according to the printing shape, and the height can also be set. For example, a configuration with a step may be used. Two layers may be attached separately to form a step.

[0101] The pattern opening 24 may have different depth dimensions depending on the location. For example, the pattern opening 24 may have multiple independent openings, or may have different thicknesses depending on the location in a continuous opening. For example, in a continuous line-shaped pattern opening 24, the coating thickness of a part may be increased or decreased, or multiple pattern openings 24 with different coating thicknesses may be formed. For example, the pattern opening 24 can be set to various shapes such as a slit-shaped line pattern, an opening with a square shape, a circular shape, etc. In addition, although an example in which the unexposed part is removed by etching has been shown, the opposite may also be true. Exposure and material may be used such that the exposed part forms an opening.

[0102] In addition, in each of the above embodiments, a so-called single mesh has been exemplified as the mesh 22, but the present invention is not limited to this. For example, the mesh 22 may have a so-called combination mesh structure including a main mesh 26 and a support mesh 27 provided on the outer periphery of the main mesh 26. Also, the mask film 23 may be formed only on a part of the center portion of the mesh 22, or the mask film 23 may be formed over the entire area.

[0103] Furthermore, the shape of the pattern opening 24 of the mask film 23 is not limited to that in the above embodiment. For example, the pattern opening 24 may be an opening whose cross-sectional shape changes in the depth direction, and the depth of the pattern opening 24 can be set. Alternatively, a protrusion continuous with the opening 24 can be formed.

[0104] Also, features of the different embodiments described above may be combined.

[0105] 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.

[0106] In addition, each component exemplified in the above embodiment may be deleted, and the shape, structure, material, etc. of each component may be changed. Various inventions can be formed by appropriate combinations of the multiple components disclosed in the above embodiment. By adjusting the dimensional ratio of the material, the difference in the amount of stretch between the length and width can be reduced, thereby improving printing accuracy. [Explanation of symbols]

[0107] 10...screen printing device, 13...squeegee, 20...screen mask, 21...frame, 22...mesh, 22a...warp thread, 22b...weft thread, 22c...hole, 23...mask membrane, 230...dry film resist, 230A...DFR laminated member, 232...base film (base film member), 233...base emulsion layer, 234...cover emulsion layer, 235...cover film (cover film member), 24...pattern opening.

Claims

1. A base film member; a cover emulsion layer laminated on one side of the base film member; a base emulsion layer laminated on one side of the cover emulsion layer; a cover film member laminated on one side of the base emulsion layer; Equipped with the cover emulsion layer is composed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, a photoinitiator and a silicone compound; The dry film laminate, wherein the base emulsion layer is composed of an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curable resin, and a photoinitiator.

2. 2. The dry film laminate according to claim 1, wherein the cover emulsion layer has a silicone compound content greater than that of the base emulsion layer.

3. 3. The dry film laminate according to claim 2, wherein the silicone compound content in the cover emulsion layer is 0.1 to 10% by weight.

4. 3. The dry film laminate according to claim 2, wherein the content of the silicone compound changes continuously at the boundary between the cover emulsion layer and the base emulsion layer.

5. The dry film laminate of claim 1 , wherein the cover emulsion layer comprises a fluorine compound.

6. 6. The dry film laminate according to claim 5, wherein the weight ratio of the silicone compound in the cover emulsion layer is smaller than the weight ratio of the fluorine compound.

7. 2. The dry film laminate according to claim 1, wherein the amount of the diazonium compound in the cover emulsion layer is greater than the amount of the diazonium compound in the base emulsion layer.

8. A support material having holes through which a coating material can pass; a mask film provided on the support material and having a pattern opening capable of holding a coating material; the mask film is attached to the support material and is composed of a dry film resist having a base emulsion layer and a cover emulsion layer laminated on one side of the base emulsion layer; A screen mask, wherein the cover emulsion layer is an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, a photoinitiator and a silicone compound, and the base emulsion layer is an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin and a photoinitiator.

9. a DFR attachment process for attaching a surface of a dry film resist on the side of the base emulsion layer, the surface being provided with a base emulsion layer and a cover emulsion layer laminated on the base emulsion layer, the cover emulsion layer being an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, a photoinitiator, and a silicone compound, and the base emulsion layer being an emulsion containing at least polyvinyl alcohol, a diazonium compound, an ultraviolet curing resin, and a photoinitiator, to a support material having holes through which a coating material can pass; an exposure treatment in which the dry film resist is exposed to light from the cover emulsion layer side in a predetermined exposure pattern; Equipped with A method for manufacturing a screen mask, comprising forming an opening in the dry film resist according to a pattern of the exposure.

10. The method for manufacturing a screen mask as described in claim 9, wherein in the DFR attachment process, a dry film resist comprising a base film, a cover emulsion layer laminated on one side of the base film, a base emulsion layer laminated on one side of the cover emulsion layer, and a cover film laminated on one side of the base emulsion layer is peeled off, the surface of the base emulsion layer is attached to the support material, and then the base film is peeled off.

11. The method for manufacturing a screen mask according to claim 9 , wherein in the exposure treatment, a photomask is placed on one side of the surface, and light is irradiated from the one side.

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