Improved screen printing plate and manufacturing method thereof

Abstract

The invention provides an improved screen printing plate and a manufacturing method thereof. The improved screen printing plate comprises a screen frame, screen cloth and a film layer. The screen cloth is arranged in the screen frame, a plurality of holes are formed in the screen cloth, and the screen cloth is provided with a scraper face and a pasting and printing face. The film layer is coated on the screen cloth, and the film layer in the opening protrudes towards one side of the scraper surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a printing screen, in particular to an improved printing screen and a method for manufacturing the same. BACKGROUND

[0002] Screen printing is a technique that involves coating a desired film thickness of emulsion layer on a screen cloth, curing, opening a pattern opening, and then repeatedly pressing an ink with a squeegee to make the ink pass through the pattern opening and print on a printing object. Screen printing has the characteristics of assisting the rapid manufacturing of industrial products, and is widely used in various industries. In today's era of rapid technological development, screen printing is even used to print electronic circuit layouts of electronic products, such as printing circuit patterns of solar cells. As electronic products become more and more precise, the film thickness required for printing circuits tends to be lower and lower, and the pattern opening tends to be finer and finer.

[0003] In addition, although the film thickness required for printing circuits tends to decrease due to demand, the overall emulsion layer is still relatively thick, and the water generated during the curing process will cause the emulsion layer to have obvious depressions. To this end, a known printing screen usually repeatedly coats one or more emulsions to make the surface of the screen cloth of the printing screen more flat, so as to avoid the decrease of ink permeability. SUMMARY

[0004] In the above case where the required film thickness is relatively low and the pattern opening is relatively fine, the screen cloth is easily worn out and even punctured by the pressure applied by the squeegee during mass printing, which greatly reduces the printing resistance and service life of the overall printing screen. In addition, due to the depressions of the cured emulsion layer, manpower and material resources are required for processing and filling, which will increase the manufacturing cost of the printing screen.

[0005] Therefore, in one aspect of the present disclosure, a printing screen is provided. The printing screen comprises a screen frame, a screen cloth, and a film layer. The screen cloth is arranged in the screen frame, wherein the screen cloth has a plurality of openings formed therein and has a squeegee surface and a printing surface. The film layer is coated on the screen cloth, wherein the film layer located in the openings is protruded towards the squeegee surface.

[0006] In an embodiment, the screen cloth is composed of a plurality of first direction threads and a plurality of second direction threads, and the openings are formed by the mesh formed by the interweaving of the first direction threads and the second direction threads.

[0007] In an embodiment, the screen cloth is an integrally formed electroformed screen or a metal plate.

[0008] In an embodiment, the film layer comprises a first polymer layer and a second polymer layer. The first polymer layer is arranged in the mesh and has a thickness smaller than the thickness of the screen cloth. The second polymer layer is arranged on the printing surface of the screen cloth.

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

[0010] In one embodiment, the first polymer layer and the second polymer layer are made of a material selected from the group consisting of 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), phenolic foam (PF), polyamide-imide (PAI), polyacrylonitrile (PAN), ABS resin, polyether ether ketone (PEEK), aramid, epoxy, and silicone.

[0011] In one embodiment, the film further comprises 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 third polymer layer is made of a material selected from the group consisting of 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), phenolic foam (PF), polyamide-imide (PAI), polyacrylonitrile (PAN), ABS resin, polyether ether ketone (PEEK), aramid, epoxy, and silicone.

[0013] In another aspect of the present disclosure, a method for manufacturing a printing screen is provided. The method for manufacturing a printing screen comprises the following steps: fixing a mesh on a screen frame; applying a first polymer layer on the mesh, wherein the first polymer layer has a thickness less than the thickness of the mesh; curing the first polymer layer; adhering a second polymer layer to one side of the mesh; and pressing the second polymer layer and the mesh.

[0014] In one embodiment, the second polymer layer is adhered to the mesh via a third polymer layer.

[0015] By the printing screen and the manufacturing method thereof of the present disclosure, the film layer can protrude towards the squeegee surface side in the openings of the screen cloth, forming a rough surface with more undulations. This special improved structure not only makes the screen cloth not easy to be worn and punctured by the squeegee, but also increases the rolling property of the ink on the squeegee surface of the screen cloth during printing, improves the overall ink penetration, and significantly improves the printing endurance and printing quality of the screen. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The schematic diagram of the architecture of the printing screen of some embodiments of the present disclosure is shown.

[0017] Figure 2 The schematic diagram of the architecture of the printing screen of some embodiments of the present disclosure is shown.

[0018] Figure 3 The schematic diagram of the side view cross section of the printing screen of some embodiments of the present disclosure is shown.

[0019] Figure 4 The scanning electron microscope image of the partial screen cloth of the printing screen of some embodiments of the present disclosure is shown.

[0020] Figure 5 The schematic diagram of the side view cross section of the printing screen of some embodiments of the present disclosure is shown.

[0021] Figure 6 The schematic diagram of the side view cross section of the printing screen of some embodiments of the present disclosure is shown.

[0022] Figure 7 The flow chart of the manufacturing method of the printing screen of some embodiments of the present disclosure is shown.

[0023] Figure 8 The flow chart of the manufacturing method of the printing screen of some embodiments of the present disclosure is shown.

[0024] The reference signs are as follows:

[0025] 100, 100-1, 100-2, 200: printing screen

[0026] 110, 210: screen frame

[0027] 120, 220: screen cloth

[0028] 120D: printing surface

[0029] 120h: first direction yarn

[0030] 120U: squeegee surface

[0031] 120v: second direction yarn

[0032] 122, 222: opening

[0033] 130, 130-1, 130-2, 230: film layer

[0034] 130a: first polymer layer

[0035] 130b: second polymer layer

[0036] 130c: third polymer layer

[0037] 240: pattern opening

[0038] 700, 800: manufacturing method

[0039] A-A': section line

[0040] S1, S2, S3, S4, S5, S6: step

[0041] T1, T2: thickness DETAILED DESCRIPTION

[0042] The specific embodiments described herein will be described in conjunction with the attached drawings, which are meant to illustrate and not to limit the present disclosure. The description of the structure and operation of the specific embodiments is not meant to limit the order of execution, any recombination of elements, or the apparatus resulting from the recombination, which are all within the scope of the present disclosure. The directional terms used in the present disclosure, such as "upper", "lower", "vertical", "horizontal", etc., are only with reference to the orientation of the attached drawings. Therefore, the directional terms used are only to illustrate and understand the present disclosure, and are not intended to limit the present disclosure. In addition, the terms "first", "second", and "third" mentioned in the present disclosure do not represent any order, quantity or importance, but are only used to distinguish different parts, and the drawings are only used to illustrate and are not drawn according to the actual size.

[0043] The words used in the specification and claims (terms), except for those specifically noted otherwise, have their ordinary meaning as used in the art, in the context of the disclosure, and in the context of the special context. Some of the words used to describe the present disclosure will be discussed below or elsewhere in the specification to provide additional guidance to those skilled in the art on the description of the present disclosure.

[0044] Please refer to Figure 1 , Figure 1The diagram shows a top view of a printing screen 100 according to some embodiments of the present disclosure. The printing screen 100 is, for example, rectangular, but not limited thereto, and is formed by stretching and fixing a mesh fabric 120 to a frame 110 under the required tension. 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 in the mesh fabric 120. Ink is then applied back and forth on the mesh fabric 120 using a squeegee to force it into the graphic opening and further adhere to the substrate below (not shown).

[0045] At Figure 1 In this embodiment, 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 the second-direction yarns 120v are used to indicate the difference between them in their direction of extension. Figure 1 In the image, the first direction yarns 120h and the second direction yarns 120v are arranged in a perpendicular manner. In practical applications, the first direction yarns 120h and the second direction yarns 120v can also be arranged in a non-perpendicular manner, such as interlacing at a specific angle or irregularly, which is not limited herein. Through the interlacing of the first direction yarns 120h and the second direction yarns 120v, a plurality of openings 122 are formed on the screen fabric 120 of the printing screen 100. In this example, these plurality of openings 122 are the mesh openings or mesh of the screen fabric 120. It should be understood that the number of first direction yarns 120h, the number of second direction yarns 120v, and the number of openings 122 formed by the two in the screen fabric 120 are only for illustration and do not represent actual application.

[0046] In another embodiment, the screen 100 may have a composite mesh 120. For example, the central area of ​​the screen 120 may be made of metal mesh, while the 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 be made of other materials. Alternatively, in one embodiment, the central area of ​​the screen 120 may be made of a non-metallic mesh bonded to a polyester fiber mesh.

[0047] In another embodiment, the screen 100 can be made of 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.

[0048] In another embodiment, the screen fabric 120 of the printing screen 100 can also be replaced with a fully open metal plate. A fully open metal plate refers to a metal plate with openings directly in the shape of the desired printed image, without first forming a structure similar to interlaced threads. Please refer to [link to relevant documentation]. Figure 2 , Figure 2 A schematic diagram of the structure of a printing screen 200 according to some embodiments of the present disclosure is shown. The printing screen 200 is formed by fixing a mesh fabric 220 onto a frame 210, and the mesh fabric 220 is a fully open metal plate. Graphic openings 240 are provided on the mesh fabric 220. Perforations 222 extend around the graphic openings 240. A film layer 230 is disposed in the perforations 222. It should be understood that the shape, number, size, proportion, and position of the graphic openings 240 and perforations 222 on the mesh fabric 220 are for illustrative purposes only. In actual applications, adjustments can be made according to requirements, and this document does not impose any limitations.

[0049] Furthermore, it should be understood that in 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 corresponding to the mesh fabric 120 are flat surfaces without any vertical or horizontal undulations. For ease of explanation, the following will use... Figure 1 An embodiment of a mesh fabric 120 having a first direction yarn 120h and a second direction yarn 120v will be described.

[0050] Please continue reading. Figure 3 , Figure 3 Show printing screen 100 along Figure 1 A side view sectional diagram along the direction of the mid-section line A-A'. Figure 3 As can be seen, the screen fabric 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 within the openings 122 protrudes towards the squeegee surface 120U, giving the squeegee surface 120U of the screen fabric 120 a more undulating, rough surface. Please refer to [the relevant documentation here]. Figure 4 , Figure 4 This shows a partial scanning electron microscope image of the mesh 120 on one side of the scraper surface 120U. Figure 4As can be seen in the cross-section of the open hole 122 formed by the interweaving of the first direction threads 120h and the second direction threads 120v, the film layer 130 presents a convex structure. The convex structure of the film layer 130 of the present disclosure helps the rolling effect of the ink during printing, making it easier for the ink to enter the graphic opening to print the printed matter, so that the printed graphic will be more full and complete, and the printing quality will be greatly improved. It should be understood that the previously mentioned integrally formed electroformed screen / metal plate or fully open metal plate all have the film layer 130 protruding towards the side of the squeegee face 120U in the open hole 122 (or the open hole 222).

[0051] In the above embodiment, the film layer 130 is 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), phenolic foam (PF), polyamide-imide (PAI), polyacrylonitrile (PAN), ABS resin, polyether ether ketone (PEEK), aramid, epoxy, or silicone, etc. In another embodiment, the film layer 130 can also be a composite material of the above-mentioned materials. For example, the film layer 130 can be made of a mixture of two or more materials, or a combination of multiple layers of different materials.

[0052] For example, referring to Figure 5 , Figure 5 A side view cross-sectional schematic diagram of a printing screen 100-1 of some embodiments of the present disclosure is shown. The printing screen 100-1 has a similar structure to the printing screen 100, and also has a screen frame 110 and a screen cloth 120, and the screen cloth 120 is also formed by the interweaving of the first direction threads 120h and the second direction threads 120v. For the parts of the printing screen 100-1 that are the same as the printing screen 100, please refer to the previous relevant paragraphs for explanation, 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 open hole 122 and has a thickness T1, and the thickness T1 is less than the thickness T2 of the screen cloth 120. If the first polymer layer 130a is too thick, it will be not conducive to the formation of the structure of the present disclosure, 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 screen cloth 120, which will be further explained when the manufacturing method of the printing screen 100 is explained below. It should be understood that Figure 5 The embodiment is only for illustration and is not drawn according to the true proportions.

[0053] The second polymer layer 130b is disposed on the printing surface 120D of the screen cloth 120 and is bonded to the screen cloth 120 and the first polymer layer 130a in a manner of being pressed together. The thickness of the second polymer layer 130b can be adjusted according to the height of the pattern to be printed, and is not limited herein. As previously described, the materials of the first polymer layer 130a and the second polymer layer 130b can be 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), phenolic foam (PF), polyamide-imide (PAI), polyacrylonitrile (PAN), ABS resin, polyether ether ketone (PEEK), aramid, epoxy resin, or silicone, etc. When the first polymer layer 130a and the second polymer layer 130b are made of the same material, although there is a sequence in the process, the appearance will be, for example, 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 are made of the same material but have different properties such as density, concentration, and viscosity, the appearance will be a film layer 130-1 with a two-layer structure.

[0054] Please further refer to Figure 6 , Figure 6 A side view cross-sectional schematic diagram of a printing screen 100-2 according to some embodiments of the present disclosure is shown. The printing screen 100-2 has a similar structure to the printing screen 100 and the printing screen 100-1, and also has a screen frame 110 and a screen cloth 120, which is formed by interlacing first direction threads 120h and second direction threads 120v, for example. For the parts of the printing screen 100-2 that are the same as the printing screen 100 and the printing screen 100-1, please refer to the previous relevant paragraphs for description, which will not be repeated here. Compared with the printing screen 100-1, the film layer 130-2 of the printing screen 100-2 further includes a third polymer layer 130c. That is, the film layer 130-2 is composed of the first polymer layer 130a, the second polymer layer 130b, and the third polymer layer 130c.

[0055] 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, which can serve as an adhesive or bonding medium between the two, helping the combination of the first polymer layer 130a and the second polymer layer 130b. In detail, when the first polymer layer 130a and the second polymer layer 130b use materials of different properties (for example, aqueous and oily), they can be less likely to bond between them, or more likely to separate after bonding. Therefore, in this embodiment, the combination of the first polymer layer 130a and the second polymer layer 130b can be assisted by the third polymer layer 130c with certain adhesion. The material of the third polymer layer 130c can also be selected from 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), phenolic foam (PF), polyamide-imide (PAI), polyacrylonitrile (PAN), ABS resin, polyether ether ketone (PEEK), aramid, epoxy or silicone, etc. The effect of the adhesive can be achieved by controlling the density / concentration / viscosity or adding other adhesive materials.

[0056] As the features of the film layer 130-1 of the printing screen 100-1 described above, when the first polymer layer 130a, the second polymer layer 130b and the third polymer layer 130c of the printing screen 100-2 are selected from the same material, although there is a sequence in the process, the appearance will also be, for example, a single film layer 130-2. Or, when the first polymer layer 130a, the second polymer layer 130b and / or the third polymer layer 130c are selected from different materials, or selected from the same material but the density / concentration / viscosity of the material has differences, the appearance may present as a film layer 130-2 with two or three layers of structure.

[0057] Please refer to Figure 7 , Figure 7 A flowchart of a method 700 of manufacturing the printing screen 100, the printing screen 100-1 or the printing screen 200 is shown. The method 700 includes steps S1-S5. Each step is described as follows:

[0058] S1: Fix the screen cloth on the screen frame.

[0059] S2: Apply the first polymer layer on the screen cloth, wherein the thickness of the first polymer layer is less than the thickness of the screen cloth.

[0060] S3: Perform a curing process on the first polymer layer.

[0061] S4: adhere a second polymer layer to one side of the screen.

[0062] S5: press the second polymer layer and the screen together.

[0063] Specifically, at step S1, the user can use a screen woven with threads, an electroformed screen, or a screen of a metal plate, and stretch the screen at a desired tension to fix it to a screen frame. At step S2, a first polymer layer in liquid form, for example in emulsion form, is applied to the screen so that the first polymer layer enters the openings of the screen. The thickness of the first polymer layer applied is less than the thickness of the screen itself. For example, when a screen with a thickness of 9-11 μm is selected, the thickness of the first polymer layer is, for example, 1-3 μm.

[0064] At step S3, the first polymer layer applied to the screen is subjected to a curing process, for example, exposure and development. Next, at step S4, a second polymer layer in solid form is adhered to one side of the screen, which will be used as the printing surface of the printing screen. Finally, at step S5, the second polymer layer is further pressed together with the screen so that the two are joined for subsequent printing.

[0065] Through the pressing process of step S5, the second polymer layer can press the first polymer layer upward so that it presents a protruding configuration upward in the openings of the screen, as shown in Figure 4 If the first polymer layer applied at step S2 is too thick, for example, the thickness of the first polymer layer exceeds 50% of the thickness of the screen, then after the curing process at step S3, the cured first polymer layer will be too hard. At this time, the pressing process at step S5 cannot successfully press the first polymer layer upward to present a protruding configuration.

[0066] Please refer to Figure 8 , Figure 8 A flowchart showing a method 800 of making a printing screen 100, a printing screen 100-1, a printing screen 100-2, or a printing screen 200. The method 800 includes steps S1-S6. Each step is described as follows:

[0067] S1: fix a screen to a screen frame.

[0068] S2: apply a first polymer layer to the screen, wherein the thickness of the first polymer layer is less than the thickness of the screen.

[0069] S3: cure the first polymer layer.

[0070] S4: adhere a second polymer layer to one side of the screen.

[0071] S5: bonding the second polymer layer under the third polymer layer.

[0072] S6: pressing the second polymer layer, the third polymer layer and the mesh fabric.

[0073] The steps S1-S3 of the manufacturing method 800 are the same as the steps S1-S3 of the manufacturing method 700. Please refer to the previous paragraphs for the description. Here, the description is not repeated. Compared with the manufacturing method 700, the manufacturing method 800 bonds the third polymer layer with adhesion to the first polymer layer after the curing treatment of the first polymer layer in step S3, and then bonds the second polymer layer to the third polymer layer in step S5, so as to achieve better bonding with the first polymer layer. Finally, in step S6, the structure of each layer is pressed and treated to form the structure of the printing screen 100, the printing screen 100-1, the printing screen 100-2 or the printing screen 200 of the present disclosure.

[0074] Although the embodiments of the present disclosure have been disclosed as above, they are not intended to limit the present disclosure. Those skilled in the art can make some changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure is defined by the appended claims.

Claims

1. An improved 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, wherein the film layer in the plurality of openings is raised toward the squeegee surface.

2. The improved printing screen of claim 1, wherein the screen cloth is composed of a plurality of first direction threads and a plurality of second direction threads, and the plurality of openings are formed by the intersections of the plurality of first direction threads and the plurality of second direction threads.

3. The improved printing screen of claim 1, wherein the screen cloth is an integrally formed electroformed screen or a metal screen.

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

5. The improved printing screen of claim 4, wherein the first polymer layer has a thickness less than 50% of the thickness of the screen cloth.

6. The improved printing screen of claim 4 or 5, wherein the first polymer layer and the second polymer layer are made of a material selected from the group consisting of polyethylene terephthalate, polyethylene, polyvinyl alcohol, polyimide, polyurethane, polyvinyl chloride, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, polyamide, polycarbonate, phenolic foam, polyamide-imide, polyacrylonitrile, ABS resin, polyether ether ketone, aromatic polyamide, epoxy resin, and silicone resin.

7. The improved printing screen of 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 to bond the first polymer layer and the second polymer layer.

8. The improved printing screen of claim 7, wherein the third polymer layer is made of a material selected from the group consisting of polyethylene terephthalate, polyethylene, polyvinyl alcohol, polyimide, polyurethane, polyvinyl chloride, polypropylene, polytetrafluoroethylene, polymethyl methacrylate, polystyrene, polyamide, polycarbonate, phenolic foam, polyamide-imide, polyacrylonitrile, ABS resin, polyether ether ketone, aromatic polyamide, epoxy resin, and silicone resin.

9. A method for manufacturing a printing screen, comprising the steps of: fixing a screen cloth to a screen frame; coating a first polymer layer on the screen cloth, wherein the first polymer layer has a thickness less than a thickness of the screen cloth; performing a curing process on the first polymer layer; attaching a second polymer layer to one side of the screen cloth; and pressing the second polymer layer and the screen cloth.

10. The method for manufacturing a printing screen of claim 9, wherein the second polymer layer is attached to the screen cloth through a third polymer layer.

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