TW202406757A - Printing screen plate with buffer structure - Google Patents

Abstract

A printing screen plate includes a mesh cloth and a plurality of buffer structures. The mesh cloth is composed of a plurality of warp yarns and a plurality of weft yarns. The plurality of buffer structures are arranged on and protruded from a printing surface of the mesh cloth. A through opening is formed between adjacent two of the buffer structures for a printing material to pass through. A height of each of the buffer structure is between 3[mu]m and 15[mu]m, and a width of each buffer structure is between 30[mu]m and 200[mu]m.

Description

Printing screen with buffer structure

The present disclosure relates to a printing screen, and in particular to a printing screen with a buffer structure.

Screen printing is used in a wide range of applications. It can even be seen in today's high-tech electronics industry, including solar cells, semiconductor components, IC carrier plates, and various other process technologies. With the booming development of electronic products, if you want to use screen printing technology to print electronic circuits, the design of the screen must be improved to adapt to the trend of increasingly smaller and more precise electronic components and achieve rapid manufacturing.

In order to print thin and thick printing graphics such as electronic circuits, off-screen printing technology is usually used, in which there is a certain distance between the screen and the printed object. When printing, the scraper will press down on the screen to contact the object to be printed, so that the printing material adheres to the object to be printed, and the tension of the mesh cloth itself is used to rebound to separate from the object to be printed. In order to achieve fast printing (for example, the squeegee movement speed is 480mm/s) while avoiding the adhesion between the screen and the printed object, which will affect the printed graphics, the rebound of the screen must have a certain speed. The existing method is to use the method of increasing the tension of the screen to achieve this.

However, the above-mentioned existing methods may cause the screen printing endurance to be reduced, and may even cause problems such as screen breakage, resulting in a significant increase in costs. Therefore, how to achieve a faster screen off-screen effect without increasing the screen tension is an important issue to be faced in screen printing technology.

In one technical aspect of this disclosure, a printing screen is proposed. The printing screen contains mesh and multiple buffer structures. The mesh is composed of a plurality of warp yarns and a plurality of weft yarns interlaced. These buffer structures are arranged and protrude from the printing surface of the mesh. A through hole is formed between two adjacent buffer structures for the passage of printing materials. The thickness of each buffer structure is between 3 μm and 15 μm, and the width is between 30 μm. to 200μm.

In one embodiment, the mesh is coated with a shielding layer, and the shielding layer has pattern openings corresponding to and connected to the through openings for printing materials to pass through.

In one embodiment, the mesh has only one of warp yarns or weft yarns at the graphic opening.

In one embodiment, the mesh is a composite mesh.

In one embodiment, the mesh is a composite mesh in which a metal mesh and a polyester mesh are laminated together.

In one embodiment, the printing screen further includes a plurality of polymer films. The polymer film is disposed on the printing surface and correspondingly covers the buffer structure, and an opening corresponding to and connecting the through port is formed between any two adjacent polymer films.

In one embodiment, the printing screen further includes a polymer film. The polymer film is disposed on the printing surface and covers the buffer structure. The polymer film has an opening corresponding to and connected to the through port.

Through the printing screen disclosed in this disclosure, it is possible to achieve rapid release and shorten the printing process, especially on polyimide mesh with a tension of less than 20 Newtons. It can also achieve the same printing effect as using high-tension mesh. At the same time, It can also maintain printing quality and protect the mesh from direct wear and tear during the printing process. The printing screen has high printing durability and longer life. In addition, through the arrangement of the polymer membrane, the buffer structure can also be well protected, and the choice of materials can be unrestricted.

The following is a detailed description of the embodiments in conjunction with the accompanying drawings. However, the specific embodiments described are only used to explain the invention and are not used to limit the invention. The description of the structural operations is not intended to limit the order of its execution. Any Structures recombined with components to produce devices with equal functions are within the scope of the disclosure of the present invention. The directional terms mentioned in the present invention, such as "up", "down", etc., are only for reference to the directions in the attached drawings. Therefore, the directional terms used are only used to illustrate and understand the present invention, but not to limit the present invention. Furthermore, the drawings are for schematic illustration only and are not drawn to their true size.

Unless otherwise noted, the terms used throughout the specification and patent claims generally have their ordinary meanings as used in the field, in the disclosure and in the particular content. Certain terms used to describe the present disclosure are discussed below or elsewhere in this specification to provide those skilled in the art with additional guidance in describing the present disclosure.

Please refer to FIG. 1 , which is a top view of a printing screen 100 according to an embodiment of the present disclosure. The printing screen 100 is, for example, rectangular, but is not limited thereto. The printing screen 100 can be formed by fixing the mesh cloth 120 on the screen frame 110 . The mesh 120 is composed of a plurality of warp yarns 122 and a plurality of weft yarns 124 interlaced. Among them, the names of the warp yarns 122 and the weft yarns 124 are used to distinguish the differences in the extending directions of the two, but are not used to limit them to be arranged in a specific direction. In this example, the warp yarns 122 and the weft yarns 124 are staggered and arranged perpendicularly to each other, which is only for convenience of illustration. In practical applications, the warp yarns 122 and the weft yarns 124 can also be staggered in a non-vertical manner, such as obliquely staggered at a specific angle, or irregularly staggered, which is not limited herein. In addition, it should be understood that the number of warp yarns 122 and the number of weft yarns 124 of the mesh fabric 120 and the number of meshes formed by the two are only for illustration and are not actual application situations.

In one embodiment, the mesh 120 can be in the form of a composite mesh. For example, the middle area of the mesh 120 is made of a metal mesh, and the outer periphery of the metal mesh is bonded with Tetoron (also known as polyester fiber), for example, by lamination. Polyester), polyester, PET polyester, etc.) mesh is joined, and then a mechanical or pneumatic mesh stretching machine is used to stretch the mesh 120 to the required tension, and then it is combined with the mesh frame 110. It should be understood that the metal mesh can be any metal, and the use of a composite mesh as the mesh cloth 120 is only one implementation. In practical applications, the material of the mesh cloth 120 can also be replaced according to requirements. For example, in one embodiment, a non-metallic mesh and a Triton mesh may be used in the middle of the mesh 120 , or the entire mesh 120 may be made of a single material. In addition, the aforementioned required tension is adjusted according to the needs of the printed product and is not particularly limited.

Referring to the embodiment of FIG. 1 , the mesh 120 is coated with a shielding layer 130 , and there are graphic openings 132 between the shielding layers 130 . Among them, the pattern opening 132 is a passage through the mesh 120 for the printing material to pass through, while the surrounding shielding area without openings shields the printing material from passing through the mesh 120 . Thereby, a pattern with the same shape as the graphic opening 132 can be printed on the printed object (not shown in this figure). Furthermore, the masking layer 130 is formed by coating an emulsion or polymer material with a required film thickness on the mesh 120 and using, for example, an exposure and development method to expose the pattern area to be printed to form the pattern openings 132 . Among them, the film thickness of the shielding layer 130 and the gauze thickness of the mesh 120 are related to the thickness of the graphics to be printed. It should be understood that the present disclosure does not limit the material, scope, shape of the shielding layer 130 and the scope, shape, number, etc. of the pattern openings 132. The designs of the shielding layer 130 and the pattern openings 132 in FIG. 1 are only for convenience. instruction. For example, the shielding layer 130 can also be coated on the entire surface of the mesh 120, and the graphic openings 132 can also be set in any shape or two or more according to the product.

Please refer to FIG. 2. FIG. 2 illustrates a side cross-sectional view of the printing screen 100 according to the cross-section line A-A' of FIG. 1 according to one embodiment of the present disclosure. In FIG. 2 , the mesh cloth 120 can be divided into an upper scraper surface 120U and a lower printing surface 120D. The scraper surface 120U is the surface where the mesh 120 contacts the scraper during printing. The printing surface 120D is the surface where the mesh 120 contacts the object to be printed during printing. The mesh 120 is provided with a plurality of protruding buffer structures 140 on the printing surface 120D, and through-holes 142 are formed between adjacent buffer structures 140 . In one embodiment, the number of positions of the through holes 142 corresponds to the pattern openings 132 , and the size of the through holes 142 is greater than or equal to the pattern openings 132 . For example, when there are two graphic openings 132, two corresponding through openings 142 can also be provided, and each through opening 142 is larger than its corresponding corresponding graphic opening 132, wherein the size of each through opening 142 can be the same or different.

Please refer to FIG. 2 and FIG. 3 together. FIG. 3 is a schematic diagram of the use of the printing screen 100 according to an embodiment of the present disclosure. In FIG. 3 , there is a distance D from the screen between the printing surface 120D of the printing screen 100 and the object 150 to be printed. When the scraper 160 presses the printing screen 100 back and forth, the printing screen 100 deforms downward as the scraper 160 reaches the position to contact the object 150 to be printed. The printing material 170 can enter the graphic opening 132 through the extrusion of the scraper 160 on the scraper surface 120U, and then enter the printing surface 120D through the passage 142 between the two adjacent buffer structures 140 to further adhere to the printed object 150 .

Specifically, the buffer structure 140 can be individually attached to the printing surface 120D of the mesh 120 , or the emulsion can be directly used to coat the printing surface 120D of the mesh 120 , and the outlet 142 can be exposed through exposure and development. The buffer structure 140 can be made of a material with good elasticity, such as thermoplastic elastomers (TPE), and its shape can be a long block shape or any shape, which is not limited herein. In addition, it should be understood that the materials of each buffer structure 140 can also be different, and the user can choose a variety of material combinations or mixed materials according to actual needs.

As mentioned previously, in traditional screen printing, the mesh often rubs against the printed matter, causing wear and tear. The protruding buffer structure 140 of the present disclosure helps prevent the mesh 120 from excessively rubbing against the printed matter during the printing process. damage. However, it should be noted that using a buffer structure with an excessively large area may increase the contact area between the printing surface and the object to be printed, resulting in an increased possibility of plate sticking and the possibility of printing line expansion. In addition, an excessively high (thick) buffer structure will slow down the printing speed of the screen, and will also prevent the printing material passing through the graphic opening area (ink permeable area) of the printing screen from forming good contact with the printed object, resulting in suspended printing. Which leads to poor printing. Therefore, the thickness of the buffer structure 140 can be set within the first preset range, and the width can be set within the second preset range, thereby limiting the thickness and/or width of the structure 140 from being too large to prevent undesirable effects.

Specifically, in one embodiment, when the first preset range of the thickness H of the buffer structure 140 is set to be between 3 μm and 15 μm, and the second preset range of the width W is set to be between 30 μm and 200 μm, good performance can be obtained. printing effect. In a preferred embodiment, when the first preset range of the thickness H of the buffer structure 140 is between 4 μm and 12 μm, and the width W is between 30 μm and 70 μm, the line shape of the printed pattern will be Best aspect ratio. By limiting the thickness and width of the buffer structure 140, the contact area between the printing screen 100 and the object to be printed is controlled, thereby controlling the adsorption force between each other within a desired range and preventing screen sticking. Since the thickness H of the buffer structure 140 is low, the distance between the printing screen 100 and the object to be printed (distance from the plate) is also low. This can prevent the rebound time of the printing screen 100 from being too long and ensure the printing speed. Moreover, when the printing screen 100 is pressed down by the scraper during the printing process, the degree of deformation is also low. Compared with the printing screen with a thicker (greater than 15μm) buffer structure, the printing durability of the printing screen 100 is significantly improved.

Please refer to FIG. 4 , which illustrates a side cross-sectional view of the printing screen 100 according to one embodiment of the present disclosure. The difference from the embodiment of FIG. 2 is that the embodiment of FIG. 4 undergoes yarn removal processing at the graphic opening 132 of the printing screen 100 . The yarn removal process is to remove the warp or weft of the mesh to form a knotless screen so that the printing screen 100 can be used to print finer circuit patterns, such as solar cells and the like. In this example, the warp yarns 122 of the mesh 120 are removed only at the graphic openings 132 . As shown in FIG. 4 , there are only weft yarns 124 but no warp yarns 122 at the graphic opening 132 . It should be understood that in another embodiment, the weft yarn 124 at the graphic opening 132 can also be removed, leaving only the warp yarn 122. Alternatively, in another embodiment, the warp yarns 122 or the weft yarns 124 that are larger than the range of the graphic opening 132 can also be removed.

However, the tension of the printing screen after yarn removal will decrease, which will cause the rebound speed of the printing screen to decrease and increase the probability of plate sticking. Therefore, in the embodiment of FIG. 4 , through the arrangement of the buffer structure 140 , the contact area between the printing screen 100 and the object to be printed is reduced, achieving rapid release. Therefore, even if the screen cloth 120 is under low tension due to yarn removal, The printing performance at high tension can still be maintained.

Next, please refer to FIG. 5 , which illustrates a side cross-sectional view of the printing screen 100 according to one embodiment of the present disclosure. Following the above, the printing screen 100 is provided with a protruding buffer structure 140 on the printing surface 120D of the mesh 120 to achieve the functions of protecting the mesh 120, quickly releasing the screen, and increasing the rebound speed of the printing screen 100. However, this The protruding structure itself may also be worn due to friction with the printed object during the printing process. Therefore, in the embodiment of FIG. 5 , a plurality of polymer films 180 are provided on the printing surface 120D to cover each buffer structure 140 , thereby reducing the wear of the buffer structure 140 during the printing process. An opening 182 corresponding to the through hole 142 is formed between two adjacent polymer films 180. The opening 182 is larger than or equal to the size of the graphic opening 132, allowing printing materials to pass through and be printed on the object to be printed. The number of openings 182 corresponds to the number of through-holes 142 .

Specifically, the polymer film 180 is, for example, a polymer material such as polyimide, which has scratch-resistant and wear-resistant properties to achieve the effect of protecting the buffer structure 140 . In one embodiment, the polymer film 180 can be attached to and cover each buffer structure 140 individually through hot pressing or adhesive bonding. Alternatively, in another embodiment, the polymer film 180 can be an integral film layer that simultaneously covers the entire printing surface 120D of the mesh 120 , and then a laser is used to engrave the polymer film 180 to correspond to the through hole 142 The opening 182 is formed. Among them, the thickness setting of the polymer film 180 is related to the desired printing pattern. Through the arrangement of the polymer film 180, the buffer structure 140 can choose any material and/or any shape with better elasticity, without considering the friction generated by the selected material and shape, so as to reduce the rebound of the printing screen 100. The effect is further improved.

It should be understood that this disclosure does not intend to limit the joining method of the polymer film 180 and the printing surface 120D, and any method that can combine the two can be applied to this disclosure. In addition, the present disclosure is not limited to only laser engraving the polymer film 180 to form the opening 182. The opening 182 can be formed by any suitable engraving or cutting method. Furthermore, the polymer membrane 180 can also be made of other appropriate materials, or a combination of multiple materials.

In another embodiment, when the size and shape of the opening 182 of the polymer film 180 are equal to the size and shape of the graphic area to be printed, the opening 182 can be directly used as the graphic opening to replace the graphic opening 132 . That is to say, in one embodiment, the printing screen 100 does not need to be coated with the masking layer 130 . Please refer to FIG. 6 , which is a side cross-sectional view of a printing screen 100 according to an embodiment of the present disclosure. In this embodiment, the printing screen 100 is not coated with the shielding layer 130 , so the buffer structures 140 are directly attached to the mesh 120 on the printing surface 120D, and the polymer film 180 covers each buffer structure 140 on the printing surface 120D. An opening 182 is formed between two adjacent polymer films 180 for the printing material to pass through, and the shape and size of the opening 182 are the same as the pattern to be printed. Therefore, when the printing material passes through the opening 182 , a pattern of the same shape and size as the opening 182 can be printed on the object to be printed. In addition, in this example, since the shielding layer 130 is not provided, the thickness of the pattern to be printed is controlled by the total thickness of the mesh 120, the buffer structure 140, and the polymer film 180.

Please refer to the following experimental data based on embodiments of the present disclosure to obtain a clearer understanding of the present disclosure. In this experiment, the mesh 120 of the printing screen 100 is made of 480.11 mesh, the thickness of the polymer film 180 is 6 μm, the width of the opening 182 is 13 μm, and a knotless screen is used. Among them, control group 1 is the printing screen without the buffer structure 140 . Thickness of buffer structure 140 Print the average line height of the graph Average spread of printed graphics Aspect ratio of printed graphics Control group 1 0μm 11.89μm 20.83μm 0.571 Experimental group A 3μm 13.68μm 23.18μm 0.590 Experimental group B 8μm 14.97μm 24.28μm 0.616

It can be seen from the above experimental data that through the arrangement of the buffer structure 140, the printed graphics of the experimental group A and the experimental group B can have a better aspect ratio than the control group 1. Among them, compared with setting the buffer structure 140 with a thickness of 3 μm (experimental group A), when the thickness of the buffer structure 140 is 8 μm (experimental group B), the printed graphics have a better aspect ratio, showing that this The disclosed printing screen technology has excellent off-board speed and rebound speed, effectively preventing adhesion between the printing screen and the printed object.

Next, please refer to the following experimental test data on low-tension mesh fabrics according to the embodiments of the present disclosure. Among them, control group 2 is a printing screen without a buffer structure 140, and experimental group C is stretched using a lower tension. Thickness of buffer structure 140 Mesh tension Print the average line height of the graph Average spread of printed graphics Aspect ratio of printed graphics Control group 2 0μm 19N 12.95μm 21.83μm 0.593 Experimental group C 8μm 15N 14.02μm 23.25μm 0.603

It can be seen from the above experimental data that through the arrangement of the buffer structure 140, experimental group C can still print a print pattern with a better aspect ratio even when the mesh tension is low. That is to say, through the printing screen of the present disclosure, even a low-tension mesh that has been stripped can maintain the printing effect of a high-tension mesh.

Although the embodiments of the disclosure have been disclosed above, they are not intended to limit the disclosure. Anyone skilled in the art can make slight changes and modifications without departing from the spirit and scope of the disclosure. Therefore, the protection of the disclosure is The scope shall be determined by the appended patent application scope.

100:Screen version 110:Screen frame 120: Mesh cloth 120U: scraper surface 120D: printing surface 122: Warp 124: weft yarn 130: Masking layer 132: Graphic opening 140:Buffer structure 142:Through the mouth 150: Printed object 160:Scraper 170: Printed materials 180:Polymer membrane 182:Opening part A-A’: hatch line D: Off-page distance H:Thickness W: Width

FIG. 1 is a top view of a printing screen according to one embodiment of the present disclosure. FIG. 2 is a side cross-sectional view of a printing screen according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram of the use of a printing screen according to an embodiment of the present disclosure. 4 is a side cross-sectional view of a printing screen according to one embodiment of the present disclosure. FIG. 5 is a side cross-sectional view of a printing screen according to an embodiment of the present disclosure. FIG. 6 is a side cross-sectional view of a printing screen according to an embodiment of the present disclosure.

100: Printing screen

110:Screen frame

120: Mesh cloth

120U: scraper surface

120D: printing surface

122: Warp

124: weft yarn

130: Masking layer

132: Graphic opening

140:Buffer structure

142:Through the mouth

H:Thickness

W: Width

Claims (7)

A printing screen consisting of: A mesh consisting of a plurality of warp yarns and a plurality of weft yarns interlaced; and A plurality of buffer structures are provided and protrude from a printing surface of the mesh. An opening is formed between two adjacent buffer structures for a printing material to pass through. The thickness of each of the buffer structures is between 3 μm and 15μm, width ranging from 30μm to 200μm. The printing screen as claimed in claim 1, wherein the screen is coated with a shielding layer, and the shielding layer has a pattern opening corresponding to and connected to the through opening for the printing material to pass. The printing screen as described in claim 2, wherein the screen cloth has only one of the warp yarns or the weft yarns at the graphic opening. The printing screen as claimed in claim 1, wherein the screen cloth is a composite screen. The printing screen as described in claim 1, wherein the mesh is a composite mesh composed of a metal mesh and a Triton mesh. The printing screen as described in any one of request items 1-5, further includes: A plurality of polymer films are disposed on the printing surface and correspondingly cover the buffer structures. An opening corresponding to and connected to the through port is formed between any two adjacent polymer films. The printing screen as described in any one of request items 1-5, further includes: A polymer film is disposed on the printing surface and covers the buffer structures. The polymer film has an opening corresponding to and connected to the through port.