CN117533007A - Printing screen with buffer structure - Google Patents

Abstract

A printing screen with buffer structure comprises screen cloth and multiple buffer structures. The mesh cloth is formed by interweaving a plurality of warp yarns and a plurality of weft yarns. The plurality of buffer structures are arranged and protrude out of the stamping surface of the mesh cloth. The buffer structures are adjacent to each other and form a through hole for the printing material to pass through, and each buffer structure has a thickness of 3-15 μm and a width of 30-200 μm.

Description

Printing screen with buffer structure

Technical Field

The present disclosure relates to printing screens, and more particularly, to a printing screen having a buffer structure.

Background

Screen printing has a very wide range of applications, even in the current high-tech electronics industry, such as various process technologies for solar cells, semiconductor devices, IC carriers, etc. With the vigorous development of electronic products, if electronic circuits are to be printed and manufactured by screen printing technology, the design of the screen must be improved to adapt to the trend that electronic components become more tiny and precise and realize rapid manufacturing.

In order to print a thin and thick printed pattern such as an electronic circuit, a stencil printing technique is generally used, in which a certain distance exists between a stencil and a printed object. When printing, the scraper presses the screen plate to contact the printed matter, so that the printing material is attached to the printed matter, and the screen cloth of the screen plate is separated from the printed matter by tension rebound. In order to achieve rapid printing (for example, the moving speed of the scraper is 480 mm/s) and avoid the phenomenon that printing patterns are affected due to adhesion between the screen printing plate and an object to be printed, the rebound of the screen printing plate needs to have a certain speed. The existing practice is to use a way to increase the tension of the screen.

Disclosure of Invention

However, the above conventional method may cause problems such as reduced number of printing passes of the screen printing plate, and even easy breaking of the screen printing plate, so that the cost is greatly increased. Therefore, how to achieve a faster screen release effect without increasing the screen tension is an important issue in screen printing technology.

In one aspect of the present disclosure, a printing screen is provided. The printing screen comprises a mesh and a plurality of buffer structures. The mesh cloth is formed by interweaving a plurality of warp yarns and a plurality of weft yarns. The buffer structures are arranged and protrude out of the stamping surface of the screen cloth, a through hole is formed between two adjacent buffer structures for the printing material to pass through, and the thickness of each buffer structure is 3-15 mu m and the width of each buffer structure is 30-200 mu m.

In one embodiment, the web is coated with a masking layer having a pattern of openings corresponding to and connected to the openings for the passage of printing material.

In one embodiment, the mesh has only one of warp or weft yarns at the pattern openings.

In one embodiment, the mesh is a composite mesh.

In one embodiment, the mesh is a composite mesh of metal mesh and Teflon mesh.

In one embodiment, the printing screen further comprises a plurality of polymeric films. The polymer films are arranged on the stamping surface and correspond to the coating buffer structure, and openings corresponding to and connected with the through holes are formed between any two adjacent polymer films.

In one embodiment, the printing screen further comprises a polymeric film. The polymer film is arranged on the printing surface and coats the buffer structure, and the polymer film is provided with an opening part corresponding to and connected with the through hole.

The printing screen plate can realize quick release and shorten printing time, especially on polyimide screen cloth with tension lower than 20 newton, the printing effect of using high-tension screen cloth can be achieved, meanwhile, the printing quality can be maintained, the screen cloth is protected from being directly worn and consumed in the printing process, and the printing screen plate has high printing resistance and longer service life. In addition, the buffer structure can be well protected by the arrangement of the polymer film, and the selection of materials is not limited.

Drawings

Fig. 1 is a top view of a printing screen of an embodiment of the present disclosure.

Fig. 2 is a side cross-sectional view of a printing screen of an embodiment of the present disclosure.

Fig. 3 is a schematic view of a printing screen used in an embodiment of the present disclosure.

Fig. 4 is a side cross-sectional view of a printing screen of an embodiment of the present disclosure.

Fig. 5 is a side cross-sectional view of a printing screen of an embodiment of the present disclosure.

Fig. 6 is a side cross-sectional view of a printing screen of an embodiment of the present disclosure.

The reference numerals are as follows:

100: screen plate

110: screen frame

120: screen cloth

120U: scraper surface

120D: paste printing surface

122: warp yarn

124: weft yarn

130: masking layer

132: graphic opening

140: buffer structure

142: through opening

150: printed matter

160: scraper knife

170: printing material

180: polymer film

182: an opening part

A-A': section line

D: plate distance

H: thickness of (L)

W: width of (L)

Detailed Description

The following examples are given in conjunction with the accompanying drawings, but the specific embodiments described are merely illustrative of the present invention and are not intended to limit the order in which the operations of the structures may be performed, and any structures in which the elements may be rearranged to produce a device with equivalent efficacy is intended to be encompassed by the present disclosure. The directional terms, such as "upper", "lower", etc., are merely referring to the directions of the accompanying drawings. Accordingly, the directional terminology is used for purposes of illustration and understanding only and is not intended to be limiting of the invention. Furthermore, the drawings are only schematically illustrated and not drawn according to their true dimensions.

The term "about" as used throughout the specification and claims, unless otherwise indicated, shall generally have the ordinary meaning of each term used in this field, in the disclosure herein, and in the special context. Certain terms used to describe the disclosure are discussed below, or elsewhere in this specification, to provide additional guidance to those skilled in the art in describing the disclosure.

Referring to fig. 1, fig. 1 shows 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 not limited to. The printing screen 100 may be formed by attaching a mesh 120 to a frame 110. The mesh 120 is formed by interweaving a plurality of warp yarns 122 and a plurality of weft yarns 124. The designations of the warp yarn 122 and the weft yarn 124 are used to distinguish the two extending directions, and are not limited to a specific direction. In this example, warp yarns 122 and weft yarns 124 are staggered in a perpendicular fashion with respect to each other, which is for ease of illustration only. In practice, the warp yarns 122 and the weft yarns 124 may be staggered in a non-perpendicular manner, such as at a specific angle, or irregularly, without limitation. Furthermore, it should be understood that the number of warp yarns 122, the number of weft yarns 124, and the mesh number formed by the two of the scrim 120 are for illustration only and are not intended to be practical.

In one embodiment, the mesh 120 may be in the form of a composite mesh, for example, a metal mesh is used in the middle area of the mesh 120, and the periphery of the metal mesh is bonded to a Tetoron (also called Polyester), polyester, PET Polyester, etc. mesh by, for example, pressing, and then the mesh 120 is stretched to a desired tension by a mechanical or pneumatic stretching machine to be combined with the frame 110. It should be understood that the metal mesh may be any metal, and the mesh 120 is only one embodiment of the composite mesh, and in practical application, the material of the mesh 120 may be replaced according to the requirement. For example, in one embodiment, the mesh 120 may be formed by pressing a non-metal mesh with a Teflon mesh, or the mesh 120 may be integrally formed of a single material. The tension required is not particularly limited, and may be adjusted according to the requirements of the printed product.

In the embodiment of fig. 1, the mesh 120 is coated with a masking layer 130, and a pattern opening 132 is formed between the masking layers 130. Wherein the pattern openings 132 are configured to allow passage of the printing material through the web 120, and the surrounding non-open masking areas mask the printing material from passing through the web 120. Thus, a pattern having the same shape as the pattern opening 132 can be printed on the object to be printed (not shown). Further, the masking layer 130 is formed by coating emulsion or polymer material with a desired film thickness on the mesh 120, and exposing the pattern area to be printed by, for example, exposure development to form a pattern opening 132. Wherein the thickness of the masking layer 130 is related to the thickness of the screen cloth 120 and the thickness of the pattern to be printed. It should be understood that the disclosure is not limited by the material, the range, the shape of the shielding layer 130, the range, the shape, the number of the pattern openings 132, etc., and the design of the shielding layer 130 and the pattern openings 132 in fig. 1 is only for convenience of description. For example, the shielding layer 130 may also coat the entire web 120, and the pattern openings 132 may be provided in any shape or two or more depending on the product.

Referring next to fig. 2, fig. 2 illustrates a side cross-sectional view of a printing screen 100 according to an embodiment of the present disclosure, as viewed along section line A-A' of fig. 1. In fig. 2, the web 120 may be divided into an upper doctor blade 120U and a lower embossing 120D. The doctor blade face 120U is the face of the web 120 that contacts the doctor blade during printing. The stamping surface 120D is the surface of the mesh 120 contacting the printed matter during printing. The mesh 120 is provided with a plurality of protruding buffer structures 140 on the stamping surface 120D, and through holes 142 are formed between adjacent buffer structures 140. In one embodiment, the number of positions of the through openings 142 corresponds to the number of the pattern openings 132, and the size of the through openings 142 is greater than or equal to the number of the pattern openings 132. For example, when there are two pattern openings 132, two corresponding openings 142 may be provided, and each opening 142 is larger than the corresponding pattern opening 132, wherein the sizes of the openings 142 may be the same or different.

Referring to fig. 2 and 3 together, fig. 3 is a schematic diagram illustrating a usage of a printing screen 100 according to an embodiment of the disclosure. In fig. 3, a plate separation distance D exists between the stamping surface 120D of the printing screen 100 and the printing object 150. As doctor blade 160 presses screen 100 back and forth, printing screen 100 deforms downward with the position of doctor blade 160 to contact object 150. The printing material 170 may be pressed by the doctor blade 160 into the pattern opening 132 on the doctor blade surface 120U, and then enter the stamping surface 120D through the through-hole 142 between two adjacent buffer structures 140 to further adhere to the printed object 150.

In detail, the buffer structure 140 may be disposed on the printing surface 120D of the mesh 120, or the printing surface 120D of the mesh 120 is directly coated with emulsion, and the through hole 142 is exposed by exposure and development. The buffer structure 140 may be made of a material with good elasticity, such as a thermoplastic elastomer (Thermoplastic Elastomers, TPE), and may be in a shape of a long block or any shape, which is not limited herein. In addition, it should be understood that the material of each buffer structure 140 may be different, and the user may select multiple materials to match or mix according to the actual requirement.

As previously described, in conventional screen printing, the screen cloth often rubs against the printed material causing wear, and the raised cushioning structure 140 of the present disclosure helps prevent damage to the screen cloth 120 caused by excessive rubbing against the printed material during printing. However, it should be noted that, if the buffer structure with an excessively large area is adopted, the contact area between the printing surface and the printed object may be increased, so that the possibility of sticking is increased, and further the possibility of printing and expanding lines is generated. In addition, too high (thick) buffer structure may slow down the printing speed of the screen, and also may prevent the printing material passing through the pattern opening area (ink permeable area) of the printing screen from making good contact with the object to be printed, resulting in suspended printing and 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, so as to limit the thickness and/or width of the structure 140 from being too large, thereby preventing undesired effects.

In detail, in one embodiment, the buffer structure 140 has a thickness H in a first predetermined range between 3 μm and 15 μm and a width W in a second predetermined range between 30 μm and 200 μm. In a preferred embodiment, when the first predetermined 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 printed pattern will have the 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, so that the adsorption force between the printing screen 100 and the object to be printed can be controlled within a desired range, and the occurrence of sticking of the printing screen can be prevented. Since the thickness H of the buffer structure 140 is low, the distance between the printing screen 100 and the object to be printed (the plate-separating distance) is also low. This prevents the rebound time of the printing screen 100 from being excessively long, and ensures the printing speed. In addition, the printing screen 100 is deformed to a low degree when being pressed down by a doctor blade during printing. The number of print resistance of the printing screen 100 is significantly improved compared to printing screens provided with thicker (greater than 15 μm) buffer structures.

Referring to fig. 4, fig. 4 shows a side cross-sectional view of a printing screen 100 of an embodiment of the present disclosure. The embodiment of fig. 4 differs from the embodiment of fig. 2 in that the embodiment of fig. 4 has been de-screened at the pattern openings 132 of the printing screen 100. The de-screening process removes the warp or weft yarns of the web to form a knotless screen so that the printing screen 100 can be used to print finer line patterns, such as solar cells and the like. In this example, the warp yarns 122 of the web 120 are removed only at the pattern openings 132. As shown in fig. 4, there are only weft yarns 124 at the pattern openings 132, and no warp yarns 122. It should be appreciated that in another embodiment, weft yarns 124 at pattern openings 132 may also be removed, leaving only warp yarns 122. Alternatively, in yet another embodiment, warp yarns 122 or weft yarns 124 that are greater than the extent of patterned openings 132 may be removed.

However, the tension of the screen printing plate after the yarn removing treatment is reduced, which results in a reduction in rebound speed of the screen printing plate and increases the probability of sticking the screen printing plate. Therefore, in the embodiment of fig. 4, by the arrangement of the buffer structure 140, the contact area between the printing screen 100 and the printed matter is reduced, and a rapid release is achieved, so that the printing performance can be maintained as in the high tension even if the mesh 120 is under the lower tension due to the yarn removal.

Referring next to fig. 5, fig. 5 shows a side cross-sectional view of a printing screen 100 of an embodiment of the present disclosure. As mentioned above, the printing screen 100 is provided with the protruding buffer structure 140 on the printing surface 120D of the mesh 120, so as to protect the mesh 120, rapidly separate the mesh, and increase the rebound speed of the printing screen 100. Therefore, in the embodiment of fig. 5, a plurality of polymer films 180 are disposed on the stamping surface 120D to cover each buffer structure 140, so as to reduce the abrasion 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, and the opening 182 is larger than or equal to the size of the graphic opening 132, so that the printing material can pass through and be printed on the printed matter. The number of the openings 182 corresponds to the number of the through holes 142.

Specifically, the polymer film 180 is a polymer material such as polyimide, and has scratch and abrasion resistance properties, so as to protect the buffer structure 140. In one embodiment, the polymer film 180 may be attached to and cover each of the buffer structures 140 by thermal pressing or adhesive bonding. Alternatively, in another embodiment, the polymer film 180 may be an integral film layer, and the entire screen 120 is coated on the stamping surface 120D, and then the polymer film 180 is engraved by a laser to form the opening 182 corresponding to the through hole 142. Wherein, the thickness of the polymer film 180 is set to be related to the desired printed pattern. By the arrangement of the polymer film 180, the buffer structure 140 can be made of any material and/or any shape with better elasticity, and the resilience effect of the printing screen 100 is further improved without considering the friction generated by the selected material and shape.

It should be understood that the present disclosure is not intended to limit the manner in which the polymeric film 180 is bonded to the stamping surface 120D, and any method that can bond the two is applicable to the present disclosure. In addition, the present disclosure is not limited to only laser engraving the polymer film 180 to form the opening 182, and the opening 182 may be formed by any suitable engraving and cutting method. Furthermore, the polymer film 180 may be made of other suitable materials or a combination of materials.

In another embodiment, when the size and shape of the opening 182 of the polymer film 180 are equal to those of the pattern area to be printed, the opening 182 can be directly used as the pattern opening instead of the pattern opening 132. That is, in one embodiment, the printing screen 100 may not be coated with the masking layer 130. Referring to fig. 6, fig. 6 shows a side cross-sectional view of a printing screen 100 of an embodiment of the present disclosure. In this embodiment, the printing screen 100 is not coated with the shielding layer 130, so that 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. Wherein, 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 having the same shape and the same size as the opening 182 can be printed on the object to be printed. In this example, the masking layer 130 is not provided, so that 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 data from experiments conducted in accordance with 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 was 480.11 mesh, the thickness of the polymer film 180 was 6 μm, the width of the opening 182 was 13 μm, and a knotless screen was used. The control group 1 is a printing screen without the buffer structure 140.

From the above experimental data, the printed patterns of the experimental group a and the experimental group B can have better aspect ratio than the control group 1 by the arrangement of the buffer structure 140. Wherein, compared with the buffer structure 140 with the thickness of 3 μm (experimental group A), when the thickness of the buffer structure 140 is 8 μm (experimental group B), the printed pattern has better height-width ratio, which shows that the printing screen technology disclosed by the disclosure has excellent plate release speed and rebound speed, and can effectively prevent adhesion between the printing screen and a printed object.

Next, please refer to experimental test data regarding low tension webs according to embodiments of the present disclosure below. Wherein, control group 2 is a printing screen without buffer structure 140, and experimental group C is stretched with lower tension.

As can be seen from the above experimental data, the experimental group C can print a printed pattern having a more excellent aspect ratio even in the case of a lower tension of the web through the arrangement of the buffer structure 140. That is, with the printing screen of the present disclosure, even a low tension web that has been de-woven can maintain a printing effect as a high tension web.

Although the embodiments of the present disclosure have been disclosed above, it should be understood that the present disclosure is not limited thereto, and that modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the present disclosure, and the scope of the present disclosure is therefore intended to be limited only by the appended claims.

Claims (7)

1. A printing screen having a cushioning structure, comprising:

the mesh cloth is formed by interweaving a plurality of warp yarns and a plurality of weft yarns; and

the buffer structures are arranged and protrude out of a printing surface of the mesh cloth, a through hole is formed between two adjacent buffer structures for a printing material to pass through, and the thickness of each buffer structure is 3-15 mu m and the width of each buffer structure is 30-200 mu m.

2. The printing screen of claim 1, wherein the web is coated with a masking layer having a graphic opening corresponding to and connected to the opening for the printing material to pass through.

3. A printing screen having a buffer structure as claimed in claim 2, wherein the mesh has only one of a plurality of said warp yarns or a plurality of said weft yarns at the pattern openings.

4. The printing screen of claim 1, wherein the web is a composite web.

5. The printing screen of claim 1 having a buffer structure, wherein the mesh is a composite mesh of metal mesh and a terdolon mesh.

6. The printing screen having a buffer structure as recited in any one of claims 1 to 5, further comprising:

the plurality of polymer films are arranged on the stamping surface and correspondingly cover the plurality of buffer structures, and an opening part corresponding to and connected with the through hole is formed between any two adjacent polymer films.

7. The printing screen having a buffer structure as recited in any one of claims 1 to 5, further comprising:

the macromolecule film is arranged on the stamping surface and coats the buffer structures, and the macromolecule film is provided with an opening part which corresponds to and is connected with the through hole.