Solar cell constant tension printing screen

Abstract

The utility model discloses a solar cell constant tension printing screen, which comprises a screen frame, a metal wire mesh and a printing plate wire slot, the metal wire mesh is tensioned on the screen frame through a tensioning wire mesh, the printing plate wire slot is arranged on the metal wire mesh, the tensioning wire mesh bypasses the arc-shaped edge of the screen frame and is bonded on the outer frame wall of the screen frame, and the printing plate wire slot is arranged on the metal wire mesh. A tension sensor is arranged between the arc-shaped edge of the screen frame and the tensioning wire screen; and a silk screen tension pressure stabilizing strip is also propped against the tensioning silk screen and is movably supported on the screen frame through a thrust spring. The silk screen tension pressure stabilizing strip abuts against the inner side face of the tension silk screen and can support the tension silk screen. The tension sensor is a thin film pressure sensor, and the installation angle alpha of the tension sensor is 45 degrees. The tension sensors are installed on the arc frame edge of the screen frame, and at least one tension sensor is installed on the arc frame edge of each side edge of the screen frame. The screen printing plate can automatically adjust the tension of the silk screen so as to ensure the stability of the tension of the silk screen.

Description

Technical Field

[0001] The utility model relates to a printing plate for solar photovoltaic cells, in particular to a screen plate for printing photovoltaic cell wafers that can automatically adjust and maintain the tension of the screen surface. Background Art

[0002] The printing screen plate for solar photovoltaic cells is composed of a screen frame and a silk screen printing plate that is stretched on the screen frame with a certain tension and fixedly adhered to the screen frame by gluing. During use, the scraping side above the silk screen printing plate is located inside the screen frame, and the squeegee scrapes and extrudes on the scraping side of the silk screen printing plate, so that the paste located on the scraping side passes through the printing pattern on the silk screen printing plate and is extruded onto the crystalline silicon cell substrate to form a solar cell electrode circuit.

[0003] The tension of the screen wire of the screen plate has a direct impact on the quality of the printed grid lines. If the tension is too large, the rebound speed of the printing screen plate is too fast, and virtual phenomena are likely to occur. Excessive tension will also cause deformation of the screen plate pattern, and even bursting of the metal wire mesh. If the tension is too small, the metal wire mesh during the printing process cannot accurately rebound and reset, and it is easy to have distortion of the printed grid line shape and fluctuations in the aspect ratio value of the grid line width, resulting in waste of the printed silver paste and reduction of the conductive performance of the grid line. At the same time, after hundreds of thousands of scrapings of the existing screen plate, the tension of the screen plate will also undergo irreversible plastic deformation, resulting in a decrease in the screen plate tension. The existing structural form of the screen printing screen plate determines that the screen plate tension cannot be automatically restored and adjusted. In the initial stage of use, its tension is often large, and after repeated scrapings, its tension will gradually decrease, resulting in fluctuations in the screen plate printing quality and even unqualified products. Summary of the Utility Model

[0004] Aiming at the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present utility model is to provide a constant-tension printing screen plate for solar cells that can automatically adjust the screen tension and ensure the stability of the tension.

[0005] To solve the above technical problems, the constant-tension printing screen plate for solar cells of the present utility model includes a screen frame, a metal wire mesh and a plate groove for the printing plate. The metal wire mesh is stretched on the screen frame through a wire mesh tensioner. The plate groove for the printing plate is arranged on the metal wire mesh. The wire mesh tensioner bypasses the arc edge of the screen frame and is adhered to the outer frame wall of the screen frame. A tension sensor is arranged between the arc edge of the screen frame and the wire mesh tensioner. A wire mesh tension stabilizing strip is also abutted on the wire mesh tensioner. The wire mesh tension stabilizing strip is movably supported on the screen frame through a thrust spring.

[0006] In the above structure, since the wire mesh tension stabilizing strip touches the top of the stretching wire mesh, and the wire mesh tension stabilizing strip is supported on the screen frame by a thrust spring; on the one hand, this structure can maintain the stability of the mesh surface tension, automatically adjust the size of the wire mesh tensile force by means of the elastic force of the thrust spring. Even if the mesh surface undergoes plastic deformation during long-term repeated use, the thrust spring can also compensate for the mesh surface relaxation caused by plastic deformation, having an excellent effect on stabilizing the mesh surface tension of the screen plate and achieving the technical effect of constant tension; on the other hand, while stabilizing the mesh surface tension, the thrust spring also increases the elasticity of the mesh surface, ensuring that the metal wire mesh rebounds and resets accurately, which is beneficial to improving the printing quality of the screen plate. Also, since a tension sensor is provided between the arc edge of the screen frame and the tension mesh, the mesh surface tension can be immediately feedback through the tension sensor, so as to immediately adjust and maintain the screen plate to ensure high-quality printing of solar photovoltaic cells.

[0007] In a preferred embodiment of the present invention, the wire mesh tension stabilizing strip touches the inner side of the stretching wire mesh, and the wire mesh tension stabilizing strip can push and move the stretching wire mesh. The wire mesh tension stabilizing strip is arranged in the corresponding installation groove of the screen frame, the thrust spring is supported on the wire mesh tension stabilizing strip through a spring guide column, and the thrust spring is a helical compression spring. The length of the strip-shaped wire mesh tension stabilizing strip is greater than or equal to the corresponding side length of the stretching wire mesh; at least two spring guide columns are installed on the wire mesh tension stabilizing strip, and a corresponding thrust spring is sleeved on each spring guide column. It can facilitate the automatic precision adjustment and compensation of the mesh surface tension of the screen plate.

[0008] In a preferred embodiment of the present invention, the tension sensor is a thin film pressure sensor, and the installation angle α of the tension sensor is 45°. The tension sensor is installed on the arc frame edge of the screen frame, and at least one tension sensor is installed on the arc frame edge of each side of the screen frame. This structure can accurately and timely monitor the mesh surface tension and ensure the stability of the screen plate tension.

[0009] In a preferred embodiment of the present invention, the scraping side of the metal wire mesh is coated with a scraping side film layer, and a plurality of scraping side wire grooves are arranged on the scraping side film layer. The printing side of the metal wire mesh is coated with a printing side film layer, and a plurality of printing side wire grooves are arranged on the printing side film layer. The groove width of the scraping side wire groove is greater than the groove width of the printing side wire groove. A material-containing structure with a stepped opening is formed, and the silver paste located in the stepped opening groove can be directly scraped out of the printing side film wire groove, thereby reducing the penetration resistance of the wire mesh to the printing paste. At the same time, the squeegee can generate a certain printing extrusion force on the paste in the stepped opening groove, promoting the transfer of the paste in the printing plate wire groove to the printing substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The following further details the constant tension printing screen plate for solar cells of the present invention in conjunction with the drawings and specific embodiments.

[0011] Figure 1 is a structural schematic diagram of a specific embodiment of the solar cell constant tension printing screen plate of the present utility model;

[0012] Figure 2 is Figure 1 the A-A sectional view structure diagram of;

[0013] Figure 3 is Figure 1 the enlarged B-B sectional view structure diagram of;

[0014] Figure 4 is Figure 3 the structure diagram of the assembly of the screen tension stabilizing strip and the spring guide post in;

[0015] Figure 5 is Figure 4 the C-C sectional view structure diagram of;

[0016] Figure 6 is Figure 5 the front view of the spring guide post in;

[0017] Figure 7 is Figure 6 the left view of;

[0018] Figure 8 is Figure 4 the front view of the screen tension stabilizing strip in;

[0019] Figure 9 is Figure 8 the top view of;

[0020] Figure 10 is Figure 1 the enlarged view of the metal wire mesh surface structure in.

[0021] In the figure, 1 - screen frame, 2 - tension wire mesh, 3 - metal wire mesh, 4 - adhesive layer, 5 - screen tension stabilizing strip, 6 - spring guide post, 7 - thrust spring, 8 - tension sensor, 9 - printing plate wire groove, 10 - guide post mounting hole, 11 - scraping side film layer, 12 - sticking side film layer, 13 - scraping side wire groove, 14 - sticking side wire groove. Specific embodiment

[0022] As Figure 1 、 Figure 2 and Figure 3The shown solar cell constant-tension printing screen plate includes a screen frame 1, which is a rectangular aluminum box member in a return shape. A metal wire mesh 3 made of stainless steel is tensioned at the center position of the screen frame 1. The four sides of the metal wire mesh 3 are bonded with wire tensioning meshes 2. The wire tensioning meshes 2 are polyester meshes. The outer extending bonding ends of the wire tensioning meshes 2 around the four sides respectively bypass the bottom arc edges of the corresponding side walls of the screen frame 1 and continue to wind up to the upper ends of the outer side walls of the screen frame 1. The wire tensioning meshes 2 are bonded to the outer side walls of the screen frame 1 through an adhesive layer 4. The adhesive layer 4 is formed by a commonly used adhesive for the printing screen plate. The printing plate wire grooves 9 are arranged on the metal wire mesh 3.

[0023] On the inner side of the section where the wire tensioning mesh 2 winds around and adheres to the outer side wall of the screen frame 1, there is a wire mesh tension stabilizing strip 5 in contact by abutment. A thrust spring 7 is supported on the wire mesh tension stabilizing strip 5. The wire mesh tension stabilizing strip 5 is supported in the corresponding groove of the screen frame 1 through the above-mentioned several thrust springs 7; each thrust spring 7 is supported on the wire mesh tension stabilizing strip 5 through a corresponding spring guiding column 6. The thrust spring 7 is a helical compression spring. The groove for accommodating the wire mesh tension stabilizing strip 5 is arranged around the outer wall of the screen frame 1.

[0024] A tension sensor 8 is arranged between the arc edge of the side wall bypassed by the wire tensioning mesh 2 and the wire tensioning mesh 2. The arc edge of the side wall is a quarter cylindrical surface, and the radius R of the cylinder where the cylindrical surface is located is one-third of the side wall thickness. The installation angle α of the tension sensor 8 = 45°. The installation angle α is the angle between the installation center line of the tension sensor 8 and the bottom surface (or top surface) of the screen frame 1. The tension sensor 8 is embedded in the screen frame 1. The tension sensor 8 is a thin film pressure sensor. The thin film pressure sensor has a simple structure, high measurement accuracy, and fast response speed, which is beneficial to the installation of the tension sensor 8 and the monitoring of the wire mesh tension.

[0025] As Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 And Figure 9 As shown, the wire mesh tension stabilizing strip 5 is a long strip-shaped aluminum plate strip. One plate surface of the aluminum plate strip is a top contact surface in contact with the wire tensioning mesh 2. A number of guide post installation holes 10 for fixedly installing the spring guiding columns 6 are arranged at equal distances on the other plate surface. The guide post installation holes 10 are cylindrical blind holes. A thrust spring 7 can be sleeved on each spring guiding column 6. The spring guiding column 6 is a stepped short cylinder or can also be a short cylinder. The length of the wire mesh tension stabilizing strip 5 is equal to the corresponding side length of the wire tensioning mesh 2 or can also be slightly longer than its corresponding side length.

[0026] As Figure 10As shown, a scraping-side film layer 11 is coated on the surface of the scraping side G of the wire mesh 3, and the scraping-side film layer 11 is formed by coating and photosensitizing photosensitive latex. The outer surface of the scraping-side film layer 11 is the scraping surface. During scraping, the squeegee directly contacts the scraping surface. A number of scraping-side wire grooves 13 are designed on the scraping-side film layer 11 according to the printing pattern, and the cross-section of the scraping-side wire groove 13 is a rectangular through groove. A printing-side film layer 12 is coated on the lower surface of the printing side T of the wire mesh 3, and the printing-side film layer 12 is pasted by polymer films such as PET, PE, PI, PU, PVC, and PS. A number of printing-side wire grooves 14 are also designed on the printing-side film layer 12 according to the printing pattern. The groove center lines of the corresponding scraping-side wire grooves 13 and printing-side wire grooves 14 are located on the same straight line, and the groove opening width of the scraping-side wire groove 13 is greater than the groove opening width of the printing-side wire groove 14, so as to form a printing plate wire groove 9 with a stepped cross-section, which is beneficial to improving the ink penetration performance of printing, improving the printing quality, and more beneficial to improving the aspect ratio of the printed electrode paste, which is beneficial to reducing the light-shielding area of the printed grid lines and can effectively reduce the consumption of the printed paste.

[0027] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

Claims

1. A solar cell constant tension printing screen, comprising a screen frame (1), a metal wire mesh (3) and a printing plate wire groove (9), wherein the metal wire mesh (3) is stretched on the screen frame (1) through a tensioning wire mesh (2), and the printing plate wire groove (9) is arranged on the metal wire mesh (3), characterized in that: The tensioned wire mesh (2) bypasses the arc-shaped edge of the mesh frame (1) and is bonded to the outer frame wall of the mesh frame (1); a tension sensor (8) is arranged between the arc-shaped edge of the mesh frame (1) and the tensioned wire mesh (2); a wire mesh tension stabilizing strip (5) is also pressed against the tensioned wire mesh (2); the wire mesh tension stabilizing strip (5) is movably supported on the mesh frame (1) via a thrust spring (7).

2. The solar cell constant tension printing screen according to claim 1, characterized in that: The wire mesh tension stabilizing strip (5) contacts the inner side surface of the tensioned wire mesh (2), and the wire mesh tension stabilizing strip (5) is capable of supporting the tensioned wire mesh (2).

3. The solar cell constant tension printing screen according to claim 1, characterized in that: The wire mesh tension stabilizing strip (5) is arranged in a corresponding mounting groove of the mesh frame (1), and the thrust spring (7) is supported on the wire mesh tension stabilizing strip (5) through a spring guide column (6), and the thrust spring (7) is a helical compression spring.

4. The solar cell constant tension printing screen according to claim 1, 2 or 3, characterized in that: The length of the wire mesh tension stabilizing strip (5) of the strip structure is greater than or equal to the corresponding side length of the tensioned wire mesh (2); at least two spring guide columns (6) are installed on the wire mesh tension stabilizing strip (5), and each spring guide column (6) is mounted with a corresponding thrust spring (7).

5. The solar cell constant tension printing screen according to claim 1, characterized in that: The tension sensor (8) is a thin film pressure sensor, and the installation angle of the tension sensor (8) is α=45°.

6. The solar cell constant tension printing screen according to claim 1 or 5, characterized in that: The tension sensor (8) is installed on the arc frame edge of the screen frame (1), and at least one tension sensor (8) is installed on the arc frame edge on each side of the screen frame (1).

7. The solar cell constant tension printing screen according to claim 1, characterized in that: The scraping side (G) of the metal wire mesh (3) is coated with a scraping side film layer (11), and a plurality of scraping side line grooves (13) are arranged on the scraping side film layer (11); the printing side (T) of the metal wire mesh (3) is coated with a printing side film layer (12), and a plurality of printing side line grooves (14) are arranged on the printing side film layer (12); the slot width of the scraping side line groove (13) is greater than the slot width of the printing side line groove (14).

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