A gridless photovoltaic cell grid line printing device

Abstract

The utility model discloses a kind of main gridless photovoltaic cell grid line printing device, including screen frame, ink delivery device and printing device;Screen frame is fixedly provided with screen;Ink delivery device includes ink delivery plate located above screen;Printing device includes doctor blade, ink return knife;Doctor blade, ink return knife, ink delivery plate are sequentially spaced along first direction;Screen has the second direction perpendicular to first direction in parallel plane;Screen has screen pattern spaced along second direction;Ink delivery plate has ink delivery face opposite to screen, ink delivery face is provided with several ink outlet spaced along second direction.This utility model utilizes the screen pattern and ink outlet of interval distribution, realizes the simultaneous test of multiple slurry and simple operation;By enabling specified ink outlet, the printing effect of screen corresponding area can be tested, which is beneficial to save slurry and improve test efficiency.

Description

Technical Field

[0001] This utility model relates to the field of solar cells, specifically to a grid-line printing device for gridless photovoltaic cells. Background Technology

[0002] Traditional photovoltaic cells typically use a main grid (thick wire) and a sub-grid (thin wire) to collect current. Gridless cells completely eliminate the main grid, retaining only a denser sub-grid, thereby reducing resistance loss and shading area.

[0003] The grid lines of photovoltaic cells are formed by printing paste onto the surface of a silicon wafer using a screen printing machine and then sintering it. The basic principle of screen printing is that the paste passes through the perforated areas of the screen, while it does not pass through the non-perforated areas. With the continuous improvement of the manufacturing process of gridless cells, cell manufacturers have increasingly higher requirements for the equipment or devices used to test the printing quality. Chinese invention patent CN115036228A discloses a silver-silicon contact resistance testing screen for silicon-based photovoltaic paste and its testing method. This method improves the structure of the screen printing plate. Specifically, a crosshair is marked in the center of the front side of the silicon wafer to divide it into four printing areas of equal size. The silicon wafer is placed face up in the printing press to print silver electrodes. First, the first type of silver paste is applied, and two rows of vertical grid lines are printed diagonally in the first two printing areas of the silicon wafer. After drying, the silicon wafer is rotated 90°, and then the second type of silver paste is applied, and two rows of horizontal grid lines are printed diagonally in the second two printing areas of the silicon wafer. After drying, the silicon wafers are placed in a chain drying oven for sintering. After sintering, the silicon wafers are removed and a contact resistance test is performed. The contact resistance test is conducted by using two styluses on a DC bridge device to contact the two adjacent grid lines of each row of vertical or horizontal grid lines on the silicon wafer. The resistance test results are displayed on the display screen of the DC bridge device, indicating that the test is complete.

[0004] However, while the above method achieves the printing of two different silver electrodes on the same silicon wafer, effectively reducing the difference in bulk resistance between different silicon wafers and ensuring the accuracy of contact resistance test results, it is complex to operate and can only test two pastes at a time. Therefore, it is necessary to develop a gridless photovoltaic cell grid line printing device with more testing functions. Utility Model Content

[0005] The purpose of this invention is to provide a grid-free photovoltaic cell grid line printing device, which can simultaneously test multiple pastes and is easy to operate.

[0006] To achieve the above technical effects, the technical solution of this utility model is as follows: a grid-less photovoltaic cell grid line printing device, comprising: a screen frame, an ink supply device, and a printing device; the screen frame is fixedly provided with a screen; the ink supply device includes an ink supply plate located above the screen; the printing device includes a doctor blade and an ink return blade; the doctor blade, ink return blade, and ink supply plate are sequentially spaced along a first direction; the screen has a second direction perpendicular to the first direction in its parallel plane; the screen has screen patterns spaced along the second direction; the ink supply plate has an ink supply surface disposed opposite to the screen, and the ink supply surface has a plurality of ink outlets spaced along the second direction.

[0007] Preferably, the ink supply plate is provided with a plurality of ink supply through holes; one end of each ink supply through hole is the ink outlet, and the other end is connected to the ink supply tube.

[0008] Preferably, the printing apparatus also includes a frame, and further includes a lifting mechanism, a horizontal guide rail fixedly connected to the frame, and a traveling component slidably connected to the horizontal guide rail; the lifting mechanism is provided with a fixing part and a lifting part, the fixing part being fixedly connected to the traveling component; the lifting part includes a doctor blade lifting part fixedly connected to the doctor blade, an ink return blade lifting part fixedly connected to the ink return blade, and an ink supply plate lifting part fixedly connected to the ink supply plate.

[0009] Preferably, the ink supply device further includes an ink storage component and an ink pump communicating with the ink supply tube; the ink storage component is fixedly connected to the frame, and the ink storage component is provided with a viewing window.

[0010] Preferably, the ink storage component includes a stirrer, which is disposed within the ink storage chamber of the ink storage component.

[0011] Preferably, a heating element is provided around the ink storage cavity, and a temperature measuring element is provided inside the ink storage cavity.

[0012] Preferably, the ink storage component also has a microparticle inlet communicating with the ink storage cavity.

[0013] Preferably, it further includes a screen printing camera, a silicon wafer camera, and a downstream conveyor belt; the screen printing camera is fixedly connected to the traveling component, and the lens of the screen printing camera faces downward; the silicon wafer camera is located above the downstream conveyor belt, and the lens of the silicon wafer camera faces downward.

[0014] The advantages and beneficial effects of this utility model are as follows: This invention utilizes the spaced-out screen patterns on the screen and the spaced-out ink outlets on the ink feeding surface to achieve simultaneous testing of multiple pastes with simple operation. By reducing the amount of ink dispensed from the ink outlet at a single time, this device can measure as much printability data as possible after the ink has just been introduced onto the screen surface, while keeping the total ink consumption constant. By enabling a specified ink outlet, the printing effect of the corresponding area of ​​the screen can be tested, which helps to save ink and improve testing efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the grid line printing device for a gridless photovoltaic cell in Example 1; Figure 2 yes Figure 1 Enlarged view of part A; Figure 3 This is a cross-sectional schematic diagram of the ink supply plate; Figure 4 This is a cross-sectional schematic diagram of the ink storage component in Example 2; In the diagram: 1. Frame; 2. Screen frame; 3. Screen; 301. Screen pattern; 4. Doctor blade; 5. Ink return blade; 6. Ink supply plate; 601. Ink supply surface; 6011. Ink outlet; 602. Ink supply through hole; 7. Ink supply tube; 8. Horizontal guide rail; 9. Traveling component; 901. Loading platform; 10. Doctor blade lifting unit; 11. Ink return blade lifting unit; 12. Ink supply plate lifting unit; 13. Ink storage component; 1301. Viewing window; 14. Ink pump; 15. Screen camera; 1302. Stirrer; 1303. Ink storage chamber; 1304. Heating element; 1305. Temperature measuring element; 1306. Particle inlet. Detailed Implementation

[0016] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0017] Example 1

[0018] like Figure 1 , Figure 2 and Figure 3As shown, the grid-less photovoltaic cell grid line printing device of Embodiment 1 includes a frame 1, a screen frame 2 fixed on the frame 1, and a horizontal guide rail 8. A screen 3 is fixed on the screen frame 2, and screen patterns 301 are spaced apart on the screen 3 in directions parallel and perpendicular to the horizontal guide rail 8. A traveling member 9 is configured on the horizontal guide rail 8, and a load platform 901 is mounted on the traveling member 9. Three independent lifting mechanisms are mounted on the load platform 901. The parts of the three lifting mechanisms that move up and down during operation are the doctor blade lifting part 10, the ink return blade lifting part 11, and the ink supply plate lifting part 12. The doctor blade lifting part 10 is fixedly connected to the doctor blade 4, the ink return blade lifting part 11 is fixedly connected to the ink return blade 5, and the ink supply plate lifting part 12 is fixedly connected to the ink supply plate 6. The doctor blade 4, the ink return blade 5, and the ink supply plate 6 are all located above the screen 3. The doctor blade 4, the ink return blade 5, and the ink supply plate 6 are distributed sequentially at intervals in directions parallel to the horizontal guide rail 8.

[0019] The ink supply plate 6 has an ink supply surface 601 that is opposite to the screen 3. The ink supply surface 601 is rectangular (the short side of the rectangle is parallel to the horizontal guide rail 8). Several ink outlets 6011 are spaced apart along the length of the ink supply surface 601. An ink supply through hole 602 is provided inside the ink supply plate 6. One end (end a) of the through hole is the ink outlet 6011, and the other end (end b) is connected to the ink supply tube 7.

[0020] The gridless photovoltaic cell grid line printing apparatus of Embodiment 1 also includes an ink storage unit 13 and an ink pump 14. The ink pump 14 delivers the ink inside the ink storage unit 13 to end b of the ink supply through the ink supply tube 7.

[0021] The printing process of this gridless photovoltaic cell grid line printing device is a reciprocating motion. When printing on the silicon wafer surface, the squeegee 4 always moves from side B of the screen 3 to side A of the screen 3.

[0022] In the initial state of the device, the doctor blade 4, the ink return blade 5, and the ink supply plate 6 are all on side A of the screen 3, and the ink supply plate 6 is on side B of the ink return blade 5, with the silicon wafer located below the screen 3.

[0023] The workflow of the grid line printing apparatus for grid-less photovoltaic cells in Example 1: First, different inks are introduced into different ink storage components 13, and the ink pump 14 delivers the inks from the different ink storage components 13 to different ink delivery holes 602 on the ink delivery plate 6 through the ink delivery pipe 7. Next, start the lifting mechanism. The scraper 4 moves upward away from the screen 3, the ink return blade 5 contacts the screen 3, and the ink supply plate 6 approaches the screen 3. Then the ink pump 14 is started and extrudes different pastes onto the surface of the screen 3. These pastes have a spacing in the length direction of the ink supply surface 601, which is close to the spacing of the screen pattern 301 in the length direction of the ink supply surface 601. Then the ink pump 14 stops working, the lifting mechanism is started, and the ink plate 6 moves away from the screen 3; After the ink supply plate 6 moves away from the screen 3, the traveling component 9 is started. The traveling component 9 drives the ink return blade 5 to scrape the slurry on the surface of the screen 3. At this time, the scraper 4 moves from side A of the screen to side B of the screen 3. Finally, the lifting mechanism is activated, the ink return blade 5 moves away from the screen 3, and after the squeegee 4 contacts the screen 3, the traveling component 9 is activated. The traveling component 9 drives the squeegee 4 to transfer the paste on the surface of the screen 3 to the surface of the silicon wafer. At this time, the squeegee 4 moves from side B of the screen 3 to side A of the screen 3.

[0024] In the above workflow, in order to test the printability of the ink when it is first introduced onto the screen 3, the device can reduce the amount of ink dispensed from the ink outlet 6011 each time, so as to obtain more experimental data while keeping the total ink consumption constant (it can even be possible to only introduce the amount of ink that is sufficient for one printing on the screen 3 each time).

[0025] By enabling the designated ink outlet 6011, the printing effect of the corresponding area of ​​screen 3 can be tested, which helps to save ink and improve testing efficiency.

[0026] The screen pattern 301 spaced apart on the screen 3 can be configured to be several identical in the vertical and / or parallel directions, thereby testing the printing effect of the screen pattern 301 in different areas of the screen 3. For this purpose, the inking plate 6 is mounted on the load table 901. This device allows for testing the printing of the screen pattern 301 in a specified area of ​​the screen 3, making the testing more targeted.

[0027] Example 2

[0028] like Figure 4 As shown, the photovoltaic cell grid line printing apparatus of Embodiment 2 is based on Embodiment 1, except that the ink storage unit 13 is fixedly connected to the frame 1 and is provided with a viewing window 1301. Through the viewing window 1301, the operator can observe the ink paste inside the ink storage unit 13. The ink storage unit 13 is used to store ink in an ink storage chamber 1303, and a stirrer 1302 for stirring the ink paste is provided inside the ink storage chamber 1303. A heating element 1304 for heating the ink paste and a temperature measuring element 1305 for measuring the ink paste temperature are provided between the ink storage chamber 1303 and the outer shell of the ink storage unit 13. In order to facilitate the introduction of ink paste into the ink storage chamber 1303, the ink storage unit 13 is also provided with a microparticle injection port 1306 communicating with the ink storage chamber 1303. This microparticle injection port 1306 is also suitable for adding fine particles to simulate the effect of impurity particles mixed in the ink paste on printing.

[0029] Based on this, the photovoltaic cell grid line printing apparatus of Embodiment 2 further includes a screen printing camera 15, a silicon wafer camera, and a downstream conveyor belt. The screen printing camera 15 is fixedly mounted on the load table 901, with its lens facing downwards. The silicon wafer camera is located above the downstream conveyor belt, with its lens also facing downwards.

[0030] Specifically, the screen printing camera 15 can record the spacing of different screen printing patterns 301 on the screen printing plate 3 and the area of ​​the screen printing patterns 301 (the actual area is calculated by comparing the image of the screen printing pattern 301 with the length scale on the screen printing plate 3) when testing different screen printing plates 3. When the grid lines on the silicon wafer surface are printed and transported downstream by the downstream conveyor belt, the silicon wafer camera records the spacing of different screen printing patterns 301 on the screen printing plate 3 and the area of ​​the screen printing patterns 301. The data recorded by the screen printing camera 15 and the silicon wafer camera facilitates the evaluation and summary of the printing effect.

[0031] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A grid-less photovoltaic cell grid line printing device, characterized in that... ,include: A screen frame, in which the screen is fixedly mounted; Ink supply device, including an ink supply plate located above the screen; Printing apparatus, including doctor blade and ink return blade; The doctor blade, ink return blade, and ink supply plate are distributed at intervals along the first direction; The screen has a second direction perpendicular to the first direction within its parallel plane; The screen printing plate has screen printing patterns spaced apart along the second direction; The ink supply plate has an ink supply surface disposed opposite to the screen, and the ink supply surface has a plurality of ink outlets spaced apart along the second direction.

2. The grid-line printing apparatus for a gridless photovoltaic cell according to claim 1, characterized in that, The ink supply plate is provided with several ink supply through holes; One end of the ink supply through hole is the ink outlet, and the other end is connected to the ink supply tube.

3. The grid-line printing apparatus for a gridless photovoltaic cell according to claim 2, characterized in that, It also includes a frame, and the printing device further includes a lifting mechanism, a horizontal guide rail fixedly connected to the frame, and a traveling component slidably connected to the horizontal guide rail; The lifting mechanism is provided with a fixed part and a lifting part, and the fixed part is fixedly connected to the traveling component; The lifting unit includes a doctor blade lifting unit fixedly connected to the doctor blade, an ink return knife lifting unit fixedly connected to the ink return knife, and an ink supply plate lifting unit fixedly connected to the ink supply plate.

4. The grid-line printing apparatus for a gridless photovoltaic cell according to claim 3, characterized in that, The ink supply device also includes an ink storage component and an ink supply pump that are connected to the ink supply tube; The ink storage device is fixedly connected to the frame, and the ink storage device is provided with a viewing window.

5. The grid-line printing apparatus for a gridless photovoltaic cell according to claim 4, characterized in that, The ink storage component includes a stirrer, which is disposed inside the ink storage chamber of the ink storage component.

6. The grid line printing apparatus for a gridless photovoltaic cell according to claim 5, characterized in that, A heating element is provided around the ink storage cavity, and a temperature measuring element is provided inside the ink storage cavity.

7. The grid-line printing apparatus for a gridless photovoltaic cell according to claim 5, characterized in that, The ink storage device also has a microparticle inlet that communicates with the ink storage cavity.

8. The grid-line printing apparatus for a gridless photovoltaic cell according to claim 3, characterized in that, It also includes screen printing cameras, silicon wafer cameras, and downstream conveyor belts; The screen camera is fixedly connected to the walking component, and the lens of the screen camera faces downwards; The silicon wafer camera is located above the downstream conveyor belt, with its lens facing downwards.

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