A kind of 0BB solar cell laser-induced sintering device

Abstract

The application provides a kind of 0BB solar cell laser-induced sintering device, including bearing platform, electric input module and laser module, battery piece is placed on bearing platform, electric input module includes power supply and first electrode and second electrode for being connected with power supply, first electrode and second electrode can be contacted with the upper surface, lower surface of battery piece respectively;First electrode includes multiple probe rows, multiple probes are arranged on each probe row along the length direction of probe row, when first electrode is contacted with the upper surface of battery piece, the probes on multiple probe rows are staggered on the upper surface of battery piece, all fine grid lines on the upper surface of battery piece are pressed, reverse bias is applied to battery piece by first electrode and second electrode, laser-induced sintering is carried out on battery piece under the irradiation of laser, and excellent metal-semiconductor contact structure is obtained.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, specifically relating to a laser-induced sintering apparatus for OBB solar cells. Background Technology

[0002] The contact resistance between the surface electrode and the back electrode of a crystalline silicon solar cell has a significant impact on the fill factor and conversion efficiency. Lower contact resistance results in higher fill factor and conversion efficiency, making the reduction of contact resistance a pressing need for major cell manufacturers. However, in pursuit of higher conversion efficiency, the sheet resistance of the emitter in the surface electrode of crystalline silicon solar cells is increasing, making it difficult to achieve lower contact resistance.

[0003] To reduce contact resistance, existing technologies employ laser-induced sintering, which uses a laser to excite charge carriers in the solar cell and directs their flow under the reverse bias of an external electric field to form a circuit. When the circuit current flows through the metal-semiconductor interface, a significant thermal effect is generated due to the relatively high contact resistance between the metal and the semiconductor, thereby further promoting the mutual diffusion between the metal and the semiconductor to obtain excellent contact characteristics after sintering.

[0004] In laser-induced sintering, a probe array consisting of multiple probes is typically pressed onto the main grid on the front side of the solar cell to apply a reverse bias voltage to the entire cell. However, for 0BB (no-grid) solar cells, the front side of the cell has only fine grid lines instead of main grid lines. A probe array is needed to press down all the fine grid lines on the front side of the cell to apply a reverse bias voltage. Existing probe arrays often struggle to press down all the fine grid lines on the front side of the cell, resulting in poor laser-induced sintering performance. Utility Model Content

[0005] In view of this, this application provides a laser-induced sintering device for OBB solar cells, which can perform laser-induced sintering when all the fine grid lines on the upper surface of the cell are pressed down, thereby obtaining excellent metal-semiconductor contact characteristics.

[0006] A laser-induced sintering device for OBB solar cells includes a support platform, an electrical input module, and a laser module;

[0007] The battery cell is placed on the support platform, and the front and back of the battery cell are provided with multiple parallel fine grid lines.

[0008] The electrical input module includes a power supply and a first electrode and a second electrode for connecting to the power supply. The first electrode can contact the upper surface of the battery cell, and the second electrode can contact the lower surface of the battery cell.

[0009] The first electrode includes multiple probe rows, and multiple probes are spaced apart along the length of each probe row. When the first electrode contacts the upper surface of the battery cell, the probes on the multiple probe rows are staggered on the upper surface of the battery cell, so that all the fine grid lines on the upper surface of the battery cell are pressed down by the probes.

[0010] When the first electrode and the second electrode are in contact with the upper and lower surfaces of the battery cell respectively to apply a reverse bias voltage to the battery cell, the laser module emits a laser beam to scan the battery cell.

[0011] Preferably, the probe array comprises a conductive material, and wires are provided at both ends of the probe array along its length, and the wires at both ends of the probe array are electrically connected to the same polarity of the power supply.

[0012] Preferably, there are two probe arrays along the extension direction of the fine grid lines, one probe array being located at one end of the battery cell and the other probe array being located at the other end of the battery cell.

[0013] Preferably, each of the probes can press against a fine grid line on the upper surface of the battery cell, and each fine grid line is pressed against by one of the probes.

[0014] Preferably, each probe has a contact portion that contacts the fine grid line, and the contact portion is circular or square.

[0015] Preferably, the wires at both ends of the plurality of probe arrays are electrically connected to the first polarity of the power supply, and the second electrode is electrically connected to the second polarity of the power supply.

[0016] Preferably, the second electrode includes a conductive portion disposed on the support platform and a conductive connector connected to the power source. The conductive connector can be electrically connected to the conductive portion, and the conductive portion is in contact with the lower surface of the battery cell.

[0017] Preferably, the conductive part is a conductive plate, the size of the conductive plate is larger than the size of the battery cell, and the conductive connector is in contact with the area of ​​the conductive plate other than the battery cell.

[0018] Preferably, the support platform has a hollowed-out portion, and the second electrode is disposed below the hollowed-out portion;

[0019] The electrical input module includes a driving mechanism that drives the second electrode through the hollow portion to directly contact the lower surface of the battery cell.

[0020] Preferably, the second electrode comprises at least one strip-shaped electrode, or at least one conductive post, or a conductive plate.

[0021] The beneficial effects of this application are:

[0022] 1. When the first electrode is pressed down to the upper surface of the cell, the probes on multiple probe rows are staggered, so that all the fine grid lines on the upper surface of the cell are pressed down by the probes. The reverse bias voltage is applied to the cell through the first electrode and the second electrode, and the cell is laser-induced sintered under laser irradiation to obtain an excellent metal-semiconductor contact structure.

[0023] 2. Along the extension direction of the fine grid lines, there is a probe array at each end of the solar cell, and each probe can press down on a fine grid line on the upper surface of the solar cell. Each fine grid line is pressed down by a probe, which can shorten the current transmission distance. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0026] Figure 1 This is a schematic diagram of the structure of a laser-induced sintering device for OBB solar cells provided in this application;

[0027] Figure 2 A perspective view of the probe array provided in this application;

[0028] Figure 3 for Figure 2 Top view of the probe array;

[0029] Figure 4 This is a schematic diagram of the first electrode pressed onto the battery cell.

[0030] In the diagram: 1-Bearing platform; 2-Electrical input module; 21-Power supply; 22-First electrode; 221-Probe array; 222-Probe; 223-Contact part; 23-Second electrode; 231-Conductive part; 232-Conductive connector; 3-Laser module; 4-Battery cell; 5-Wire. Detailed Implementation

[0031] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] During the laser-induced sintering process of OBB solar cells, since the upper surface of the cell only has fine grid lines and no main grid lines, it is difficult to press down all the fine grid lines on the upper surface of the cell when using existing probe arrays to contact the upper surface of the cell. This results in poor laser-induced sintering effect of gridless solar cells and limited improvement in the contact performance between metal and semiconductor.

[0034] Therefore, this application provides a laser-induced sintering apparatus for OBB solar cells, with reference to... Figure 1-4 It includes a support platform 1, an electrical input module 2, and a laser module 3;

[0035] The battery cell 4 is placed on the support platform 1. The front and back of the battery cell 4 are provided with multiple parallel fine grid lines 41.

[0036] The electrical input module 2 includes a power supply 21 and a first electrode 22 and a second electrode 23 for connecting to the power supply 21. The first electrode 22 can contact the upper surface of the battery cell 4, and the second electrode 23 can contact the lower surface of the battery cell 4.

[0037] The first electrode 22 includes a plurality of probe rows 221, each of the probe rows 221 having a length direction along the probe row 221. Figure 3 Multiple probes 222 are spaced apart in the x direction. When the first electrode 22 contacts the upper surface of the battery cell 4, the probes 222 on the multiple probe rows 221 are staggered on the upper surface of the battery cell 4, so that all the fine grid lines 41 on the upper surface of the battery cell 4 are pressed by the probes 222.

[0038] When the first electrode 22 and the second electrode 23 are in contact with the upper and lower surfaces of the battery cell 4 respectively to apply a reverse bias voltage to the battery cell 4, the laser module 3 emits a laser beam to scan the battery cell 4.

[0039] This application uses a first electrode 22 to contact the upper surface of the battery cell 4 and a second electrode 23 to contact the lower surface of the battery cell 4. Both the first electrode 22 and the second electrode 23 are connected to the power supply 21, thereby applying a reverse bias voltage to the battery cell 4. It can be understood that the first electrode 22 and the second electrode 23 are electrically connected to the power supply 21 with different polarities.

[0040] Specifically, this application involves setting up multiple probe rows 221, with multiple probes 222 spaced apart along the length of each probe row 221 (see reference). Figure 2-3 When the first electrode 22 contacts the upper surface of the battery cell 4, the probes 222 on the multiple probe arrays 221 are staggered on the battery cell 4, so that all the fine grid lines 41 on the upper surface of the battery cell 4 can be pressed by the probes 222, thereby applying a reverse bias voltage to the battery cell 4. The laser-induced sintering device of this application can obtain excellent metal-semiconductor contact performance, and the performance of the obtained battery cell 4 is significantly improved.

[0041] Preferred, Reference Figure 4 This application provides two probe arrays 221 along the extension direction of the fine grid line 41. One probe array 221 is located at one end of the battery cell 4, and the other probe array 221 is located at the other end of the battery cell 4. Each probe 222 can press a fine grid line 41 on the upper surface of the battery cell 4, and each fine grid line 41 is pressed by a probe 222, which can shorten the current transmission distance.

[0042] Specifically, multiple probes 222 on one probe row 221 press down all the odd-numbered fine grid lines 41 on the upper surface of the cell 4, while multiple probes 222 on the other probe row 221 press down all the even-numbered fine grid lines 41 on the upper surface of the cell 4.

[0043] The laser module 3 in this embodiment includes a laser and a laser scanning assembly (neither shown in the figure). The laser is used to emit a laser beam, and the laser scanning assembly is used to control the scanning direction of the laser beam. The laser scanning assembly may include a galvanometer and a field mirror, or other scanning methods, as long as they can control the scanning of the laser beam. During laser-induced sintering of the battery cell 4, the laser beam scans the battery cell 4 along the laser scanning area. When the probes 222 on the two probe rows 221 are both pressed against the fine grid lines 41 on the upper surface of the battery cell 4, the two probe rows 221 are located beside the laser scanning area of ​​the battery cell 4, so that the probe rows 221 do not block the laser scanning area.

[0044] It is understood that each probe 222 has a contact portion 223 that contacts the fine grid line 41. This application does not specifically limit the shape of the contact portion 223, as long as one contact portion 223 can press against one fine grid line 41. Preferably, the contact portion 223 is circular or square.

[0045] like Figure 1 and Figure 2 As shown, along the length of the probe array 221, both ends of the probe array 221 are provided with wires 5, and the wires 5 provided at both ends of the probe array 221 are electrically connected to the same polarity of the power supply 21.

[0046] Both ends of the probe array 221 are electrically connected to the power supply 21 of the same polarity via wires 5. This reduces resistance, resulting in better laser-induced sintering and a superior metal-semiconductor contact structure. Furthermore, the wires 5 on both probe arrays 221 are electrically connected to the power supply 21 of the same polarity.

[0047] It is understood that all probe arrays 221 and probes 222 contain conductive materials, so that probe arrays 221 connected to power supply 21 via wires 5 can simultaneously energize multiple probes 222 disposed on probe arrays 221.

[0048] Specifically, the wires 5 at both ends of the two probe arrays 221 are electrically connected to the first polarity of the power supply 21, and the second electrode 23 is electrically connected to the second polarity of the power supply 21, thereby forming a circuit.

[0049] Continue to refer to Figure 1 The second electrode 23 includes a conductive part 231 disposed on the support platform 1 and a conductive connector 232 connected to the power supply 21. The conductive connector 232 can be electrically connected to the conductive part 231, and the conductive part 231 is in contact with the lower surface of the battery cell 4.

[0050] Specifically, this embodiment also includes a driving mechanism (not shown in the figure). Under the action of the driving mechanism, the conductive connector 232 moves up and down. When it is necessary to apply a reverse bias voltage to the battery cell 4, the driving mechanism drives the conductive connector 232 to move downward until it contacts the conductive part 231. During this process, the first electrode 22 can be pressed down to the upper surface of the battery cell 4 under the action of the same driving mechanism. That is, under the action of the driving mechanism, the conductive connector 232 contacts the conductive part 231, and the contact part 223 of each probe 222 contacts the fine grid line 41 on the upper surface of the battery cell 4. The specific structure of the driving mechanism is existing technology. For example, it can be a Z-axis driving module or other driving mechanisms that can achieve the purpose of this embodiment. It will not be described in detail here. Of course, the first electrode 22 and the conductive connector 232 can also be driven independently by separate driving mechanisms. Alternatively, the conductive connector 232 can always be electrically connected to the conductive part 231. When it is necessary to apply a reverse bias voltage to the battery cell 4, the first electrode 22 is pressed down to the upper surface of the battery cell 4 under the action of the driving mechanism, so that the contact part 223 contacts the fine grid line 41 on the upper surface of the battery cell 4.

[0051] In this embodiment, the conductive part 231 can be disposed on the support platform 1 in various ways. For example, at least a portion of the surface of the support platform 1 can serve as the conductive part 231. Specifically, the entire support platform 1 can be made of conductive material, and the battery cell 4 can be placed directly on the conductive support platform 1. Alternatively, only the part of the surface of the support platform 1 that contacts the battery cell 4 can be made of conductive material. In this embodiment, it is preferable that the part of the surface of the support platform 1 that contacts the battery cell 4 is made of conductive material, so that the lower surface of the battery cell 4 contacts this part of the surface of the support platform 1.

[0052] It can also be like Figure 1 The conductive part 231 shown is a conductive plate. The conductive plate is placed on the support platform 1. The size of the conductive plate is larger than the size of the battery cell 4. The battery cell 4 is placed on the conductive plate so that the lower surface of the battery cell 4 contacts the conductive plate. The conductive connector 232 contacts the area on the conductive plate other than the battery cell 4.

[0053] The conductive connector 232 includes at least one conductive post; that is, to achieve electrical connection, the conductive connector 232 only needs to have at least one contact that connects to the conductive part 231. Preferably, there are four conductive posts, which are separately arranged on both sides of the battery cell 4.

[0054] Furthermore, the conductive part 231 is preferably made of copper, which has good conductivity and is relatively inexpensive.

[0055] In another embodiment of this application, the support platform 1 has a hollowed-out portion (not shown in the figure), and the second electrode 23 is disposed below the hollowed-out portion. Under the action of the driving mechanism, the second electrode 23 can pass through the hollowed-out portion and directly contact the lower surface of the battery cell 4. More specifically, the second electrode 23 can be an electrode including at least one strip, or an electrode including at least one conductive post, or a conductive plate, as long as it can make the lower surface of the battery cell 4 electrically connected to the power supply 21.

[0056] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical parts between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0057] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0058] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser-induced sintering apparatus for OBB solar cells, characterized in that, It includes a support platform (1), an electrical input module (2), and a laser module (3); The battery cell (4) is placed on the support platform (1), and the front and back of the battery cell (4) are provided with multiple parallel fine grid lines (41). The electrical input module (2) includes a power supply (21) and a first electrode (22) and a second electrode (23) for connecting to the power supply (21). The first electrode (22) can contact the upper surface of the battery cell (4), and the second electrode (23) can contact the lower surface of the battery cell (4). The first electrode (22) includes multiple probe rows (221), and multiple probes (222) are spaced apart along the length direction of each probe row (221). When the first electrode (22) contacts the upper surface of the battery cell (4), the probes (222) on the multiple probe rows (221) are staggered on the upper surface of the battery cell (4), so that all the fine grid lines (41) on the upper surface of the battery cell (4) are pressed by the probes (222). When the first electrode (22) and the second electrode (23) are in contact with the upper and lower surfaces of the battery cell (4) respectively to apply a reverse bias voltage to the battery cell (4), the laser module (3) emits a laser beam to scan the battery cell (4).

2. The OBB solar cell laser-induced sintering apparatus according to claim 1, characterized in that, The probe array (221) contains a conductive material. Along the length of the probe array (221), both ends of the probe array (221) are provided with wires (5), and the wires (5) provided at both ends of the probe array (221) are electrically connected to the same polarity of the power supply (21).

3. The OBB solar cell laser-induced sintering apparatus according to claim 1, characterized in that, Two probe arrays (221) are provided along the extension direction of the fine grid line (41), one of the probe arrays (221) is located at one end of the battery cell (4), and the other probe array (221) is located at the other end of the battery cell (4).

4. The OBB solar cell laser-induced sintering apparatus according to claim 3, characterized in that, Each of the probes (222) can press down on a fine grid line (41) on the upper surface of the battery cell (4), and each fine grid line (41) is pressed down by one of the probes (222).

5. The OBB solar cell laser-induced sintering apparatus according to claim 1, characterized in that, Each of the probes (222) has a contact portion (223) that contacts the fine grid line (41), and the contact portion (223) is circular or square.

6. The OBB solar cell laser-induced sintering apparatus according to claim 2, characterized in that, The wires (5) at both ends of the plurality of probe arrays (221) are electrically connected to the first polarity of the power supply (21), and the second electrode (23) is electrically connected to the second polarity of the power supply (21).

7. The OBB solar cell laser-induced sintering apparatus according to any one of claims 1-6, characterized in that, The second electrode (23) includes a conductive part (231) disposed on the support platform (1) and a conductive connector (232) connected to the power source (21). The conductive connector (232) can be electrically connected to the conductive part (231), and the conductive part (231) is in contact with the lower surface of the battery cell (4).

8. The OBB solar cell laser-induced sintering apparatus according to claim 7, characterized in that, The conductive part (231) is a conductive plate, the size of which is larger than the size of the battery cell (4), and the conductive connector (232) is in contact with the area of ​​the conductive plate other than the battery cell (4).

9. The OBB solar cell laser-induced sintering apparatus according to any one of claims 1-6, characterized in that, The support platform (1) has a hollowed-out portion, and the second electrode (23) is disposed below the hollowed-out portion; The electrical input module (2) includes a driving mechanism that drives the second electrode (23) through the hollow portion to directly contact the lower surface of the battery cell (4).

10. The OBB solar cell laser-induced sintering apparatus according to claim 9, characterized in that, The second electrode (23) includes at least one strip-shaped electrode, or at least one conductive post, or a conductive plate.

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