Improved printing screen plate and manufacture method thereof

Abstract

A printing screen comprises a frame, a screen cloth, and a film layer. The screen cloth is set within the frame, and has a plurality of openings formed therein, as well as a squeegee side and a printing side. The film layer is applied to the screen cloth, wherein the film layer located in the openings protrudes towards the squeegee side.

Description

[Technical Field]

[0001] This disclosure relates to a printing screen, and more particularly to an improved printing screen and a method for manufacturing the same. [Previous Technology]

[0002] Screen printing is a technique that involves coating a screen with an emulsion layer of the required thickness and curing it, creating pattern openings, and then using a squeegee to scrape and press the ink back and forth, forcing the ink through these pattern openings and printing it onto the substrate. Because screen printing facilitates rapid manufacturing of industrial products, it is widely used in various industries. In today's highly technologically advanced era, screen printing is even used to print the electronic circuit layouts of electronic products, such as printing circuit patterns for solar cells. As electronic products become increasingly sophisticated, the film thickness required for printing circuits is becoming increasingly thinner, and the pattern openings are becoming increasingly finer.

[0003] In addition, although the film thickness required for printed circuits has been decreasing due to demand, the overall emulsion layer is still relatively thick. The moisture loss during the curing process will cause obvious depressions in the emulsion layer. To address this, it is common practice to recoat the printing screen with one or more layers of emulsion to make the screen surface flatter and avoid a decrease in ink penetration. [Summary of the Invention]

[0004] When the required film thickness is low and the pattern opening is small, the screen is easily worn or even punctured by the pressure applied by the squeegee during mass printing, resulting in a significant reduction in the overall durability and lifespan of the printing screen. In addition, since the cured emulsion layer is recessed, it is necessary to rework it with manpower and spend materials to fill it, which will increase the production cost of the printing screen.

[0005] Therefore, a printing screen is provided in one of the technical embodiments disclosed herein. The printing screen includes a frame, a screen cloth, and a film layer. The screen cloth is disposed in the frame, wherein a plurality of openings are formed on the screen cloth, and it has a squeegee side and a printing side. The film layer is coated on the screen cloth, wherein the film layer located in the openings protrudes toward the squeegee side.

[0006] In one embodiment, the mesh fabric is composed of a plurality of first-direction yarns and a plurality of second-direction yarns, and the openings are meshes formed by the interlacing of the first-direction yarns and the second-direction yarns.

[0007] In one embodiment, the mesh is an integrally formed electroformed mesh or metal plate.

[0008] In one embodiment, the film layer includes a first polymer layer and a second polymer layer. The first polymer layer is disposed within the mesh openings and has a thickness less than the thickness of the mesh fabric. The second polymer layer is disposed on the printing surface of the mesh fabric.

[0009] In one embodiment, the thickness of the first polymer layer is less than 50% of the thickness of the mesh fabric.

[0010] In one embodiment, the materials of the first polymer layer and the second polymer layer are selected from the group consisting of PET, PE, PI, PU, ​​PVC, PP, PTFE, PMMA, PS, PA, PC, PF, PAI, PAN, ABS, PEEK, Aramid, Epoxy and Silicone.

[0011] In one embodiment, the film layer further includes a third polymer layer. The third polymer layer is disposed between the first polymer layer and the second polymer layer to bond the first polymer layer and the second polymer layer.

[0012] In one embodiment, the material of the third polymer layer is selected from the group consisting of polyethylene terephthalate, polyethylene, polyvinyl alcohol, polyimide, polyurethane, polyvinyl chloride, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, polyamide, polycarbonate, phenol formaldehyde, polyamide amide, polyacrylonitrile, ABS resin, polyether ether ketone, aromatic polyamide, epoxy resin and silicone resin.

[0013] Another technical embodiment disclosed herein discloses a method for manufacturing a printing screen. The method for manufacturing a printing screen includes the following steps: fixing a screen fabric to a screen frame; coating the screen fabric with a first polymer layer, wherein the thickness of the first polymer layer is less than the thickness of the screen fabric; curing the first polymer layer; attaching a second polymer layer to one side of the screen fabric; and pressing the second polymer layer and the screen fabric together.

[0014] In one embodiment, the second polymer layer is bonded to the mesh through the third polymer layer.

[0015] Through the printing screen and its manufacturing method disclosed herein, the film layer can protrude towards the squeegee surface in the openings of the screen fabric, forming a more undulating and rough surface. This special improved structure not only makes the screen fabric less susceptible to wear and puncture by the squeegee, but also increases the rolling properties of ink on the squeegee surface of the screen fabric during printing, improving the overall ink penetration. The screen's resistance to ink wear and printing quality are significantly improved simultaneously.

Implementation Method

[0017] The following detailed description uses embodiments in conjunction with the accompanying drawings. However, the specific embodiments described are merely illustrative of this disclosure and are not intended to limit it. The description of structural operations is not intended to restrict the order of their execution. Any structure resulting from the recombination of elements, producing a device with equivalent functionality, is within the scope of this disclosure. Directional terms used in this disclosure, such as "up," "down," "vertical," and "horizontal," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are only for illustrating and understanding this disclosure and are not intended to limit it. Furthermore, the terms "first," "second," and "third" used in this disclosure do not represent any order, quantity, or importance; they are only used to distinguish different parts. The accompanying drawings are merely illustrative and are not drawn to actual dimensions.

[0018] Unless otherwise specified, the terms used throughout this specification and the claims have their ordinary meaning in the context of the art, the disclosure, and the specific content thereof. Certain terms used to describe this disclosure will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the disclosure.

[0019] Please refer to Figure 1, which illustrates a top view of the structure of a printing screen 100 according to some embodiments of the present invention. The printing screen 100 is, for example, rectangular, but not limited thereto, and is made by stretching and fixing a mesh fabric 120 on a screen frame 110 according to the required tension, and a film layer 130 is further coated on the mesh fabric 120. In actual printing, a graphic opening (not shown) of the desired printed graphic shape is made on the mesh fabric 120, and then ink is scraped back and forth on the mesh fabric 120 by a squeegee to squeeze into and pass through the graphic opening, and further adhere to the substrate below (not shown).

[0020] In the embodiment of FIG. 1, the mesh fabric 120 is composed of multiple first-direction yarns 120h and multiple second-direction yarns 120v interwoven together. The names of the first-direction yarns 120h and second-direction yarns 120v are used to indicate the difference between them in their extension direction. In FIG. 1, the first-direction yarns 120h and second-direction yarns 120v are arranged in a perpendicular manner. In practical applications, the first-direction yarns 120h and second-direction yarns 120v can also be arranged in a non-perpendicular manner, such as interlacing at a specific angle or irregularly, etc., which is not limited herein. Through the interweaving of the first-direction yarns 120h and second-direction yarns 120v, a plurality of openings 122 are formed on the mesh fabric 120 of the printing screen 100. In this example, these plurality of openings 122 are the mesh openings or mesh of the mesh fabric 120. It should be understood that the number of yarns 120h in the first direction, the number of yarns 120v in the second direction, and the number of openings 122 formed by the two in the mesh fabric 120 are only for illustration and do not represent actual application.

[0021] In another embodiment, the screen 100 may be a composite screen, for example, the middle area of ​​the screen 120 may be a metal mesh, and the outer periphery of the metal mesh may be made of a polymer material bonded to a polyester fiber mesh. It should be understood that the metal mesh may be any metal, and the polyester fiber mesh may also be made of other materials. Alternatively, in one embodiment, the middle of the screen 120 may be made of a non-metallic mesh bonded to a polyester fiber mesh.

[0022] In another embodiment, the screen 120 of the printing screen 100 can be replaced with an integrally formed electroformed screen or metal plate. Specifically, a structure similar to the interlacing of the first direction yarns 120h and the second direction yarns 120v can be directly formed by electroforming. Alternatively, the required number of openings can be formed on the metal plate by laser or chemical etching to similarly form a structure similar to the interlacing of the first direction yarns 120h and the second direction yarns 120v.

[0023] In another embodiment, the screen 120 of the printing screen 100 may also be a fully open metal plate. A fully open metal plate refers to a metal plate with a graphic opening of the desired printed shape directly formed, without first forming a structure similar to interlaced yarns. Please refer to Figure 2, which illustrates a schematic diagram of the structure of the printing screen 200 of some embodiments disclosed herein. The printing screen 200 is formed by fixing a screen 220 to a frame 210, and the screen 220 is a fully open metal plate. Graphic openings 240 are formed on the screen 220. Holes 222 extend around the graphic openings 240. A film layer 230 is disposed in the holes 222. It should be understood that the shape, number, size, proportion, and position of the graphic openings 240 and holes 222 on the screen 220 are only for illustration; in actual applications, they can be adjusted according to requirements, and this document does not impose any limitations.

[0024] Furthermore, it should be understood that in the embodiments employing the aforementioned electroformed mesh or metal plate, the longitudinal and transverse structures of the first direction yarn 120h and the second direction yarn 120v of the mesh fabric 120 have no vertical or horizontal undulations, but are flat surfaces. For ease of explanation of the disclosed technology, the following description will use the embodiment of the mesh fabric 120 with the first direction yarn 120h and the second direction yarn 120v shown in FIG1 as an example.

[0025] Please refer to Figure 3 next. Figure 3 shows a side cross-sectional view of the printing screen 100 along the section line A-A' in Figure 1. In Figure 3, it can be seen that the screen 120 has a squeegee surface 120U and a printing surface 120D. The squeegee surface 120U is the surface that contacts the squeegee (not shown) during printing, while the printing surface 120D is the surface that faces the substrate (not shown) during printing. The portion of the film layer 130 in the opening 122 protrudes towards the squeegee surface 120U, giving the squeegee surface 120U of the screen 120 a more undulating and rough surface. Please also refer to Figure 4 here. Figure 4 shows a partial scanning electron microscope image of the screen 120 on the squeegee surface 120U side. As shown in Figure 4, the film layer 130 has a raised structure in the opening 122 formed by the interlacing of the first direction yarn 120h and the second direction yarn 120v. The raised structure of the film layer 130 disclosed herein facilitates the rolling effect of ink during printing, making it easier for ink to enter the pattern opening to print the substrate. Therefore, the printed pattern will be fuller and more complete, and the printing quality will be greatly improved. It should be understood that the integrally formed electroformed mesh / metal plate or the fully open metal plate mentioned above all have a film layer 130 that protrudes towards the squeegee surface 120U in the opening 122 (or opening 222).

[0026] Continuing with the above embodiments, the film layer 130 may be made of a single material such as polyethylene terephthalate (PET), polyethylene (PE), polyvinyl alcohol (PVA), polyimide (PI), polyurethane (PU), polyvinyl chloride (PVC), polypropylene (PP), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), polystyrene (PS), polyamide (PA), polycarbonate (PC), phenol formaldehyde (PF), polyamide amide (PAI), polyacrylonitrile (PAN), ABS resin, polyether ether ketone (PEEK), aromatic polyamide (Aramid), epoxy resin, or silicone resin. In another embodiment, the film layer 130 may also be a composite material of the above materials. For example, the film layer 130 may be made of a mixture of two or more materials, or it may be a combination of multiple layers of different materials.

[0027] For example, please refer to FIG5, which illustrates a side cross-sectional view of a printing screen 100-1 according to some embodiments disclosed herein. The printing screen 100-1 has a structure similar to that of the printing screen 100, also having a frame 110 and a mesh fabric 120, and the mesh fabric 120 is, for example, formed by interlacing first direction yarns 120h and second direction yarns 120v. Regarding the parts of the printing screen 100-1 that are the same as those of the printing screen 100, please refer to the relevant paragraphs above for description, which will not be repeated here. The difference between the printing screen 100-1 and the printing screen 100 is that the film layer 130-1 of the printing screen 100-1 is composed of a first polymer layer 130a and a second polymer layer 130b. The first polymer layer 130a is disposed in the opening 122 and has a thickness T1, which is less than the thickness T2 of the mesh fabric 120. If the first polymer layer 130a is too thick, it will be detrimental to the formation of the disclosed structure. Therefore, in a preferred embodiment, the thickness T1 of the first polymer layer 130a should be less than 50% of the thickness T2 of the mesh fabric 120. This will be further explained below when describing the manufacturing method of the printing screen 100. It should be understood that the embodiment in Figure 5 is for illustration only and is not drawn to scale.

[0028] Regarding the second polymer layer 130b, it is disposed on the printing surface 120D of the mesh fabric 120 and bonded to the mesh fabric 120 and the first polymer layer 130a by pressing. The thickness of the second polymer layer 130b can be adjusted according to the height of the desired printed pattern, and is not limited herein. As mentioned above, the materials of the first polymer layer 130a and the second polymer layer 130b are polyethylene terephthalate, polyethylene, polyvinyl alcohol, polyimide, polyurethane, polyvinyl chloride, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, polyamide, polycarbonate, phenol formaldehyde, polyamide amide, polyacrylonitrile, ABS resin, polyetheretherketone, aromatic polyamide, epoxy resin, or silicone resin, etc. When the first polymer layer 130a and the second polymer layer 130b are made of the same material, although they are manufactured in a specific order, they will appear as a single film layer 130-1. Alternatively, when the first polymer layer 130a and the second polymer layer 130b are made of different materials, or when they are made of the same material but their density, concentration, viscosity, or other properties differ, they may appear as a film layer 130-1 with a two-layer structure.

[0029] Please refer further to FIG6, which shows a side cross-sectional view of a printing screen 100-2 according to some embodiments disclosed herein. The printing screen 100-2 has a structure similar to that of the printing screens 100 and 100-1, and also has a frame 110 and a mesh fabric 120, which is formed, for example, by interlacing first direction yarns 120h and second direction yarns 120v. For the parts of the printing screen 100-2 that have the same structure as the printing screens 100 and 100-1, please refer to the relevant paragraphs above, which will not be repeated here. Compared to the printing screen 100-1, the film layer 130-2 of the printing screen 100-2 further includes a third molecular layer 130c. That is, the film layer 130-2 is composed of a first polymer layer 130a, a second polymer layer 130b, and a third molecular layer 130c.

[0030] Specifically, in the film layer 130-2 of the printing screen 100-2, the third polymer layer 130c is disposed between the first polymer layer 130a and the second polymer layer 130b. It can act as an adhesive or bonding medium between the two, helping to bond the first polymer layer 130a and the second polymer layer 130b. More specifically, when the first polymer layer 130a and the second polymer layer 130b are made of materials with different properties (e.g., water-based and oil-based), they may be more difficult to bond, or easier to separate after bonding. Therefore, in this embodiment, the third polymer layer 130c, which has a certain degree of viscosity, can assist in the bonding of the first polymer layer 130a and the second polymer layer 130b. The material of the third polymer layer 130c can also be selected from polyethylene terephthalate, polyethylene, polyvinyl alcohol, polyimide, polyurethane, polyvinyl chloride, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, polyamide, polycarbonate, phenol formaldehyde, polyamide amide, polyacrylonitrile, ABS resin, polyether ether ketone, aromatic polyamide, epoxy resin or silicone resin, etc. The adhesive effect can be achieved by controlling the density / concentration / viscosity or by adding other adhesive materials.

[0031] As described above, when the first polymer layer 130-1, the second polymer layer 130b, and the third polymer layer 130c of the printing screen 100-2 are made of the same material, although they have a specific order in the manufacturing process, they will appear as a single film layer 130-2. Alternatively, when the first polymer layer 130a, the second polymer layer 130b, and / or the third polymer layer 130c are made of different materials, or when they are made of the same material but the density, concentration, viscosity, and other properties of the material differ, they may appear as a film layer 130-2 with a two- or three-layer structure.

[0032] Please refer to Figure 7, which illustrates a flowchart of a method 700 for manufacturing a printing screen 100, printing screen 100-1, or printing screen 200. The manufacturing method 700 includes steps S1 to S5. Each step is explained as follows: S1: Fix the mesh fabric to the screen frame. S2: Coat the mesh fabric with a first polymer layer, wherein the thickness of the first polymer layer is less than the thickness of the mesh fabric. S3: Cure the first polymer layer. S4: Attach a second polymer layer to one side of the mesh fabric. S5: Press the second polymer layer and the mesh fabric together.

[0033] Specifically, in step S1, the user can use a woven mesh, an electroformed mesh, or a metal plate mesh, depending on the requirements, and stretch the mesh to the required tension to fix it to the frame. In step S2, a liquid first polymer layer is coated onto the mesh, which can be, for example, in emulsion form, so that the first polymer layer enters the openings of the mesh. The thickness of the first polymer layer coating will be less than the thickness of the mesh itself. For example, if a mesh with a thickness of 9~11μm is used, the thickness of the first polymer layer is, for example, 1~3μm.

[0034] In step S3, the first polymer layer coated on the mesh is cured, for example by exposure and development. Next, in step S4, the solid second polymer layer is adhered to one side of the mesh, which will be used as the printing surface of the printing screen. Finally, in step S5, the second polymer layer and the mesh are further pressed together to bond them together for subsequent printing.

[0035] Through the pressing process in step S5 above, the second polymer layer can press the first polymer layer upwards, so that it presents an upwardly convex structure in the mesh openings, as shown in Figure 4. If the first polymer layer coated in step S2 is too thick, for example, if the thickness of the first polymer layer exceeds 50% of the mesh thickness, then after the curing treatment in step S3, the hardness of the cured first polymer layer will be too high. At this time, in the pressing process of step S5, it will be impossible to smoothly press the first polymer layer upwards to present a convex shape.

[0036] Please refer to Figure 8 next. Figure 8 shows a flowchart of the manufacturing method 800 for printing screen 100, printing screen 100-1, printing screen 100-2, or printing screen 200. The manufacturing method 800 includes steps S1 to S6. The steps are explained as follows: S1: Fix the mesh fabric to the screen frame. S2: Coat the mesh fabric with a first polymer layer, wherein the thickness of the first polymer layer is less than the thickness of the mesh fabric. S3: Cure the first polymer layer. S4: Attach a third polymer layer to one side of the mesh fabric. S5: Attach a second polymer layer below the third polymer layer. S6: Press the second polymer layer, the third polymer layer, and the mesh fabric together.

[0037] Steps S1 to S3 of manufacturing method 800 are the same as those of manufacturing method 700. Please refer to the relevant paragraphs above for explanation, and they will not be repeated here. Compared with manufacturing method 700, in manufacturing method 800, after curing the first polymer layer in step S3, an adhesive third polymer layer is first bonded in step S4, and then the second polymer layer is bonded to the third polymer layer in step S5, thereby achieving a better bonding degree with the first polymer layer. Finally, in step S6, the layers are pressed together to form the structure of the printing screen 100, printing screen 100-1, printing screen 100-2, or printing screen 200 disclosed herein.

[0038] Although the embodiments disclosed herein have been disclosed above, they are not intended to limit this disclosure. Anyone skilled in the art may make some modifications and refinements without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be defined by the appended claims. [Simplified Explanation of the Diagram]

[0016] Figure 1 illustrates a schematic diagram of the structure of a printing screen according to some embodiments of the present invention. Figure 2 illustrates a schematic diagram of the structure of a printing screen according to some embodiments of the present invention. Figure 3 illustrates a side cross-sectional view of a printing screen according to some embodiments of the present invention. Figure 4 illustrates a scanning electron microscope image of a portion of the mesh of a printing screen according to some embodiments of the present invention. Figure 5 illustrates a side cross-sectional view of a printing screen according to some embodiments of the present invention. Figure 6 illustrates a side cross-sectional view of a printing screen according to some embodiments of the present invention. Figure 7 illustrates a flowchart of the method for manufacturing a printing screen according to some embodiments of the present invention. Figure 8 illustrates a flowchart of the method for manufacturing a printing screen according to some embodiments of the present invention.

Claims

1. A printing screen comprising: a screen frame; a screen cloth disposed in the screen frame, wherein the screen cloth has a plurality of openings formed thereon and has a squeegee surface and a printing surface; and a film layer coated on the screen cloth and filling the openings, wherein the film layer located in the openings protrudes toward the squeegee surface.

2. The printing screen as described in claim 1, wherein the screen is composed of a plurality of first-direction yarns and a plurality of second-direction yarns, and the openings are meshes formed by the interlacing of the first-direction yarns and the second-direction yarns.

3. The printing screen as described in claim 1, wherein the screen is an integrally formed electroformed screen or a screen structure formed by a metal plate.

4. The printing screen as claimed in claim 1, wherein the film layer comprises: a first polymer layer disposed in the openings and having a thickness less than the thickness of the screen fabric; and a second polymer layer disposed on the printing surface of the screen fabric.

5. The printing screen as described in claim 4, wherein the thickness of the first polymer layer is less than 50% of the thickness of the screen fabric.

6. The printing screen as described in claim 4 or 5, wherein the materials of the first polymer layer and the second polymer layer are selected from the group consisting of polyethylene terephthalate, polyethylene, polyvinyl alcohol, polyimide, polyurethane, polyvinyl chloride, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, polyamide, polycarbonate, phenol formaldehyde, polyamide amide, polyacrylonitrile, ABS resin, polyether ether ketone, aromatic polyamide, epoxy resin and silicone resin.

7. The printing screen as described in claim 4 or 5, wherein the film layer further comprises: a third polymer layer disposed between the first polymer layer and the second polymer layer for bonding the first polymer layer and the second polymer layer.

8. The printing screen as described in claim 7, wherein the material of the third polymer layer is selected from the group consisting of polyethylene terephthalate, polyethylene, polyvinyl alcohol, polyimide, polyurethane, polyvinyl chloride, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, polyamide, polycarbonate, phenol formaldehyde, polyamide amide, polyacrylonitrile, ABS resin, polyetheretherketone, aromatic polyamide, epoxy resin, and silicone resin.

9. A method for manufacturing a printing screen, comprising the following steps performed in sequence: fixing a screen fabric to a screen frame; coating the screen fabric with a first polymer layer, wherein the thickness of the first polymer layer is less than the thickness of the screen fabric; curing the first polymer layer; attaching a second polymer layer to one side of the screen fabric; and pressing the second polymer layer and the screen fabric together.

10. The method for manufacturing a printing screen as described in claim 9, wherein the second polymer layer is bonded to the screen fabric through a third polymer layer.

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