A heterojunction cell screen printing process gradient curing thermal cycle oven

Abstract

The utility model provides a kind of heterojunction cell screen printing process gradient solidification heat cycle oven, including two support frames, several array distribution transmission shafts are rotatably equipped between the support frames of two sides, the transmission shaft outer end surface is fixedly connected with sprocket, transmission chain belt is wound between the sprocket of each side, two bearing basket frames are installed in the top end of transmission chain belt, several battery pieces arrayed from top to bottom are inserted in the bearing basket frame. The scheme is through three-zone gradient temperature control (150℃→200℃→180℃), and combines temperature-time-resistivity multi-objective optimization algorithm, the low-temperature silver paste solidification time is shortened from traditional 45~60 minutes to 19 minutes, the unit energy consumption is significantly reduced while the production capacity is significantly improved.

Description

Technical Field

[0001] This utility model relates to the field of printing machine technology, specifically to a gradient curing thermal circulation furnace for the screen printing process of heterojunction batteries. Background Technology

[0002] The basic requirements for electrode fabrication are: the ability to form a reliable ohmic contact with silicon, good electrical conductivity, and high current collection efficiency.

[0003] Due to the inherent characteristics of heterojunction solar cells, low-temperature pastes are required. Compared with conventional silver pastes, low-temperature silver pastes have completely different compositions, rheological properties, and printability. This requires the low-temperature silver paste to have high conductivity, low contact resistance with the TCO film layer, and to ensure that the main grid welding pull force meets the requirements.

[0004] Since low-temperature silver paste is used as an electrode in heterojunction solar cell technology, the curing temperature of low-temperature silver paste is generally around 200°C or below, and the required time is about 45 to 60 minutes. Such processing conditions make traditional short-time high-temperature sintering furnaces unsuitable for heterojunction solar cell technology. It is necessary to find other suitable curing process conditions or equipment, which not only need to meet the requirements of long-term temperature stability, but also need to meet the high production capacity required for mass production of heterojunction solar cells. Summary of the Invention

[0005] Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a gradient curing thermal circulation furnace for the screen printing process of heterojunction batteries, which solves the problems mentioned in the background art.

[0007] Technical solution

[0008] To achieve the above objectives, this utility model is implemented through the following technical solution: a gradient curing thermal circulation furnace for screen printing of heterojunction batteries, comprising two horizontal support frames, with a plurality of arrayed transmission shafts rotatably arranged between the two support frames, sprockets fixedly connected to the outer end face of the transmission shafts, and a transmission chain belt wound between the sprockets on each side, with two detachable load-bearing basket frames installed at the top of the transmission chain belts, and a plurality of battery cells arranged in an array from top to bottom inserted into the load-bearing basket frames, and a duct design plate fixedly connected to the two support frames on opposite sides, with a plurality of arrayed air duct control valves arranged on opposite sides of the duct design plates.

[0009] Preferably, a top baffle for the flower basket is installed at the top of the flower basket support frame, and a bottom baffle for the flower basket is installed at the bottom of the flower basket support frame.

[0010] Preferably, two vertically positioned battery cell hub baffles are fixedly provided between the bottom baffle and the top baffle of the flower basket.

[0011] Preferably, the top end of the transmission chain is provided with a plurality of upward-facing chain fixing grooves, and the chain fixing grooves are distributed in an array.

[0012] Preferably, the bottom of the bottom baffle of the flower basket can be installed on the top of the chain fixing groove and play a role in fixing the installation.

[0013] Preferably, a data cable is connected to one side of the air duct design plate.

[0014] Preferably, one end of the data cable extends outward and is connected to a curing heat circulation oven control terminal. Beneficial effects

[0015] This invention provides a gradient curing thermal circulation oven for the screen printing process of heterojunction batteries. It has the following beneficial effects:

[0016] This solution uses a three-zone gradient temperature control (150℃→200℃→180℃) and combines a temperature-time-resistivity multi-objective optimization algorithm to shorten the curing time of low-temperature silver paste from the traditional 45-60 minutes to 19 minutes, significantly increasing production capacity while significantly reducing unit energy consumption.

[0017] This solution utilizes a three-dimensional air duct design (XYZ axial wind speed difference < 0.5m / s) to coordinate left and right direct airflow (X-axis) with front and rear circulating airflow (Y / Z-axis). This improves the furnace cavity temperature uniformity from the traditional 20-30℃ temperature difference to ±1.5℃, and the temperature difference between the cavity edge and center is < 1.8℃, completely eliminating local overheating and insufficient curing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the external structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the main structure of this utility model;

[0020] Figure 3 This is a top view of the structure of this utility model;

[0021] Figure 4 This utility model Figure 3 A cross-sectional view along the AA direction.

[0022] In the diagram: 101, support frame; 102, transmission chain; 103, air duct design plate; 104, top baffle of the flower basket; 105, battery cell; 106, central baffle of the battery cell; 107, air duct control valve; 108, data cable; 109, curing heat circulation oven control terminal; 110, bottom baffle of the flower basket; 111, chain fixing groove; 112, sprocket; 113, transmission shaft; 114, load-bearing flower basket frame. Detailed Implementation

[0023] This utility model embodiment provides a gradient curing thermal circulation oven for the screen printing process of heterojunction batteries, such as... Figure 1-4 As shown, the support frame includes two horizontal supports 101. Several arrayed transmission shafts 113 are rotatably arranged between the two support frames 101. Sprockets 112 are fixedly connected to the outer end face of the transmission shafts 113. A transmission chain belt 102 is wound between the sprockets 112 on each side. Two detachable load-bearing basket frames 114 are installed at the top of the transmission chain belt 102. Several battery cells 105 are inserted into the load-bearing basket frames 114 in an array from top to bottom. A duct design plate 103 is fixedly connected to the two support frames 101 on the side away from each other. Several arrayed air duct control valves 107 are arranged on the side of the air duct design plate 103 that is close to each other.

[0024] It should be further noted that the air duct control valve 107 is connected to the drying hot air outlet pipe inside the curing oven.

[0025] Furthermore, a flower basket top baffle 104 is installed at the top of the flower basket support frame 114, and a flower basket bottom baffle 110 is installed at the bottom of the flower basket support frame 114.

[0026] Furthermore, two vertically positioned battery cell hub baffles 106 are fixedly installed between the bottom baffle 110 and the top baffle 104 of the flower basket.

[0027] Furthermore, the top of the transmission chain 102 is provided with several upward-facing chain fixing grooves 111, and the chain fixing grooves 111 are distributed in an array.

[0028] Furthermore, the bottom of the flower basket bottom baffle 110 can be installed on the top of the chain fixing groove 111 and play a role in fixing the installation.

[0029] It should be further explained that the curing heat circulation furnace is equipped with a power motor, which is poweredly connected to the transmission shaft 113 on one side. When the power motor starts, it can drive the transmission shaft 113 on one side to rotate through the power connection, and drive the bottom baffle 110 of the flower basket installed with the chain fixing groove 111 to move and adjust its position through the transmission chain belt 102.

[0030] Furthermore, a data cable 108 is connected to one side of the air duct design board 103.

[0031] Furthermore, one end of the data cable 108 extends outward and is connected to the curing heat circulation oven control terminal 109.

[0032] It should be further explained that the curing heat circulation oven control terminal 109 controls the on / off state of the air duct control valve 107, and the data cable 108 is connected to the air duct control valve 107 on each side to transmit control signals.

[0033] It is worth further explaining that the curing heat circulation oven control terminal 109 controls the on / off of the air duct control valves 107 in different areas, and accelerates the process and temperature matching rate according to the temperature-time-resistivity multi-objective optimization algorithm. By realizing the three-dimensional air duct design, it forms mainly left and right direct air and front and rear circulating air, thereby realizing the three-zone gradient temperature control process module (150℃→200℃→180℃).

[0034] When using this solution, the screen-printed heterojunction solar cells 105 are inserted into the supporting flower basket frame 114, and their positions are fixed by the top baffle 104 and the bottom baffle 110 of the flower basket. The spacing between the solar cells is corrected by the solar cell central baffle 106 to ensure that each solar cell is parallel and does not contact each other. Then, the bottom of the loaded supporting flower basket frame 114 is embedded into the chain fixing groove 111 at the top of the drive chain belt 102, and a stable fixation is achieved by mechanical engagement.

[0035] Subsequently, the system was started through the curing heat cycle oven control terminal 109, and the three-zone gradient temperature control process parameters were set: Zone 1: 150℃ (preheating stage), Zone 2: 200℃ (main curing stage), Zone 3: 180℃ (slow cooling stage). The temperature-time-resistivity multi-objective optimization algorithm was activated simultaneously to dynamically match the temperature curve with the curing rate.

[0036] Subsequently, the power motor drives the transmission shaft 113 to rotate, which in turn drives the transmission chain belt 102 to move at a constant speed through the sprocket 112, so that the load-bearing basket frame 114 passes through the three temperature zones in sequence. At this time, the three-dimensional air duct control is activated, and the control terminal 109 adjusts the opening of the air duct control valve 107 through the data cable 108 to achieve coordinated air supply in the XYZ axes. The left and right direct airflow (X-axis) ensures the uniformity of the transverse temperature of the cavity, while the front and rear circulating airflow (Y / Z-axis) enhances the penetration of hot airflow and reduces the temperature difference between the edge and the center. The wind speed difference in each axis is controlled to be <0.5m / s to ensure that the surface of the battery cell is heated evenly.

[0037] After the process is completed, the curing time is about 19 minutes. The transmission chain 102 transports the flower basket frame to the exit end, removes the supporting flower basket frame 114, and checks the uniformity of the cell line resistance (3σ≤4.2%) and welding tensile strength. If it meets the process requirements, it will proceed to the next process.

[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heterojunction cell screen printing process gradient curing thermal cycle furnace, characterized by: It includes two support frames (101), and several arrayed transmission shafts (113) are rotatably arranged between the two support frames (101). A sprocket (112) is fixedly connected to the outer end face of the transmission shaft (113). A transmission chain belt (102) is wound between the sprockets (112) on each side. Two load-bearing basket frames (114) are installed at the top of the transmission chain belt (102). Several battery cells (105) are inserted into the load-bearing basket frames (114) arranged in an array from top to bottom. A duct design plate (103) is fixedly connected to the two support frames (101) on the side away from each other. Several arrayed air duct control valves (107) are arranged on the side of the air duct design plate (103) that is close to each other.

2. The gradient curing thermal circulation oven for the screen printing process of a heterojunction battery according to claim 1, characterized in that: The top of the flower basket support frame (114) is equipped with a flower basket top baffle (104), and the bottom of the flower basket support frame (114) is equipped with a flower basket bottom baffle (110).

3. The gradient curing thermal circulation oven for the screen printing process of a heterojunction battery according to claim 2, characterized in that: Two battery cell central baffles (106) are fixedly provided between the bottom baffle (110) and the top baffle (104) of the flower basket.

4. The gradient curing thermal circulation oven for the screen printing process of a heterojunction battery according to claim 3, characterized in that: The top of the transmission chain (102) is provided with a number of upward-opening chain fixing grooves (111), and the chain fixing grooves (111) are arranged in an array.

5. The gradient curing thermal circulation oven for the screen printing process of a heterojunction battery according to claim 4, characterized in that: The bottom of the flower basket bottom baffle (110) can be installed on the top of the chain fixing groove (111) and play a fixed installation role.

6. The gradient curing thermal circulation oven for the screen printing process of a heterojunction battery according to claim 1, characterized in that: A data cable (108) is connected to one side of the air duct design board (103).

7. The gradient curing thermal circulation oven for the screen printing process of a heterojunction battery according to claim 6, characterized in that: One end of the data cable (108) extends outward and is connected to the curing heat circulation oven control terminal (109).

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