Battery piece CVD (chemical vapor deposition) carrier plate and CVD film thickness detection device

Abstract

The utility model provides a battery piece CVD (Chemical Vapor Deposition) carrier plate and a CVD film thickness detection device. The battery piece CVD carrier plate comprises a carrier plate main body and a plurality of bearing areas arranged on the carrier plate main body. And the plurality of bearing areas are arranged in a matrix. The bearing area comprises a plurality of battery piece bearing areas and at least one detection piece bearing area, and the detection piece bearing area is arranged in a downward concave mode relative to the battery piece bearing areas. According to the battery piece CVD carrier plate and the CVD film thickness detection device, the operation process can be simplified, and the detection efficiency can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and particularly to a CVD carrier for battery wafers and a CVD film thickness detection device. Background Art

[0002] The HJT silicon heterojunction battery, also known as the HIT (Heterojunction with intrinsic thin layer) battery, has characteristics such as high efficiency and high Voc. This battery generally uses an N-type silicon wafer as the substrate, and the general manufacturing process is: texturing, CVD, PVD, screen printing & testing.

[0003] The heterojunction CVD process, full name PECVD (Plasma Enhanced Chemical Vapor Deposition), is the core process of the heterojunction battery. The current general deposition process is to first deposit the I layer on the P side, then deposit the I layer on the N side and the N side doping layer, and finally deposit the P side doping layer, and generally 4 coating layers can be deposited. The thicknesses of these 4 coating layers vary according to different processes, however, the goal of keeping the thickness of each layer the same for each production is consistent.

[0004] The inconsistency of the film layer thickness often affects the various performances of the battery wafers, so it is necessary to measure and monitor the film layer thickness of CVD. The film layer thickness of the heterojunction (3 - 20 nm) is relatively thin, and the current general measurement methods for PERC cannot accurately measure it, that is, it cannot be directly measured using the production wafers with pyramids, and it is necessary to use polished wafers or glass deposited films for fitting measurement. Currently, ellipsometry is generally used to measure the film thickness. After using polished wafers, glass wafers, etc. to deposit the film layer, a xenon lamp is used as the light source on the ellipsometer to measure the change in the polarization state and fit and calculate the thickness of the film.

[0005] However, the current film thickness detection of heterojunction CVD requires stopping production, then putting the samples to be tested (polished wafers or glass wafers) into the carrier platform, allowing the samples to be coated normally, and finally taking them out of the CVD equipment to test the thickness of the samples. Since the whole process is complex in operation and affects the output, it is often detected once per shift or monitored when there is an abnormality, and the monitoring time interval is too long, so the purpose of timely detecting abnormalities cannot be achieved.

[0006] Therefore, it is necessary to provide an improved CVD carrier for battery wafers and a CVD film thickness detection device to solve the above problems. Utility Model Content

[0007] This application provides a CVD carrier for battery wafers and a CVD film thickness detection device that simplify the operation process and improve the detection efficiency.

[0008] The present application discloses a CVD carrier plate for solar cells, which includes a carrier plate main body and a plurality of bearing areas formed on the carrier plate main body. The plurality of bearing areas are arranged in a matrix. The bearing areas include a plurality of solar cell bearing areas and at least one test piece bearing area. The test piece bearing area is recessed downward compared with the solar cell bearing areas.

[0009] Further, the solar cell bearing area has a first bearing surface for placing the solar cell, and the test piece bearing area is recessed downward to form a second bearing surface for placing the test piece. A carrier plate upper surface is formed on the carrier plate main body. The distance from the first bearing surface to the carrier plate upper surface is less than the distance from the second bearing surface to the carrier plate upper surface.

[0010] Further, the solar cell bearing area is further provided with a first slot located below the first bearing surface, and the first slot has a first bottom surface parallel to the first bearing surface.

[0011] Further, it further includes a gasket. The gasket can be placed in the test piece bearing area and cooperate with the test piece bearing area to form the solar cell bearing area.

[0012] Further, the gasket has a third bearing surface for placing the solar cell. When the gasket is placed in the test piece bearing area, the height of the third bearing surface is the same as that of the first bearing surface.

[0013] Further, the gasket is provided with a second slot located below the third bearing surface, and the second slot has a second bottom surface parallel to the third bearing surface.

[0014] Further, the solar cell bearing area further has a first positioning surface vertically connecting the first bearing surface and the carrier plate upper surface; the test piece bearing area further has a third positioning surface vertically connecting the second bearing surface and the carrier plate upper surface.

[0015] Further, the test piece bearing area is arranged near the center of the carrier plate main body or near the edge of the carrier plate main body.

[0016] The present application also discloses a CVD film thickness detection device, which includes a test piece, an automatic loading device, an automatic unloading device, a control device, and the above-mentioned CVD carrier plate for solar cells; the control device is used to control the automatic loading device to place the test piece on the test piece bearing area before coating and control the automatic unloading device to remove the test piece from the test piece bearing area after coating.

[0017] Further, the test piece is a polished silicon wafer or a glass sheet; the thickness of the test piece is 0.2 mm - 0.5 mm.

[0018] The CVD carrier plate for solar cells and the CVD film thickness detection device of the present application simultaneously set a solar cell bearing area and a test piece bearing area on the carrier plate body, so that each carrier plate body can transport solar cells and test pieces at the same time, improving the detection frequency, facilitating the timely discovery of production abnormalities, and improving the yield rate of solar cells. At the same time, the test piece bearing area is set to be recessed downward compared with the solar cell bearing area, so that the upper surfaces of the test pieces placed in the bearing area are at the same height as those of the solar cells, enabling the test pieces to be coated simultaneously with the production process of the solar cells, simplifying the film thickness detection process, and improving the film thickness detection efficiency.

[0019] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this specification. Description of the Drawings

[0020] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments consistent with this specification, and are used together with the specification to explain the principles of this specification.

[0021] Figure 1 is a top view of the CVD carrier plate for solar cells of the present application.

[0022] Figure 2 is a cross-sectional view of the solar cell bearing area of the present application.

[0023] Figure 3 is Figure 2 a cross-sectional view of the test piece bearing area in when placing a solar cell.

[0024] Figure 4 is a cross-sectional view of the test piece bearing area of the present application.

[0025] Figure 5 is Figure 4 a cross-sectional view of the test piece bearing area in when placing a test piece.

[0026] Figure 6 is a top view of the gasket of the present application.

[0027] Figure 7 is Figure 6 a partial cross-sectional view of the gasket in .

[0028] Description of the attached reference numerals: 10, main body of the carrier plate; 11, upper surface of the carrier plate; 20, bearing area; 21, battery cell bearing area; 211, first bearing surface; 212, first positioning surface; 22, test piece bearing area; 221, second bearing surface; 222, third positioning surface; 23, first slot; 231, first bottom surface; 232, second positioning surface; 30, gasket; 301, third bearing surface; 31, second slot; 311, second bottom surface; 312, fourth positioning surface; 40, battery cell; 50, test piece. Detailed implementation manners

[0029] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this specification. Unless otherwise defined, the technical terms or scientific terms used in this specification should have the ordinary meanings understood by those with ordinary skills in the field to which this application belongs. The "first", "second" and similar terms used in this specification and the claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, the terms such as "a" or "one" do not indicate a quantity limitation, but indicate the existence of one. "Multiple" or "several" means two or more. Unless otherwise specified, the similar terms such as "front part", "rear part", "lower part" and / or "upper part" are only for convenience of description and are not limited to one position or a spatial orientation. The terms such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. The terms such as "connect" or "be connected" are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect.

[0030] This application provides an improved CVD carrier plate for battery cells and a CVD film thickness detection device. Next, the embodiments of this application will be described in detail.

[0031] As Figure 1 shown, this application provides a CVD carrier plate for battery cells, including a main body 10 of the carrier plate and a plurality of bearing areas 20 opened on the main body 10 of the carrier plate. The plurality of bearing areas 20 are arranged in a matrix. Specifically, in this embodiment, a total of 98 bearing areas 20 are provided on the main body 10 of the carrier plate, and the 98 bearing areas are divided into two groups and symmetrically arranged on the main body 10 of the carrier plate.

[0032] Please refer to Figure 2 and Figure 3, the carrier area 20 includes a plurality of cell carrier areas 21. A carrier plate main body 10 forms a carrier plate upper surface 11. The cell carrier area 21 has a first bearing surface 211 and a first positioning surface 212. The first bearing surface 211 is located below the carrier plate upper surface 11 and is arranged parallel to the carrier plate upper surface 11 for placing the cell 40. The first positioning surface 212 is vertically connected between the first bearing surface 211 and the carrier plate upper surface 11 for positioning the cell 40.

[0033] Furthermore, the cell carrier area 21 is further provided with a first slot 23 located below the first bearing surface 211. The first slot 23 has a first bottom surface 231 and a second positioning surface 232. The first bottom surface 231 is parallel to the first bearing surface 211, and the second positioning surface 232 is vertically connected between the first bottom surface 231 and the first bearing surface 211. The setting of the first slot 23 makes a stepped structure formed in the cell carrier area 21. When the cell 40 is placed in the cell carrier area 21, it does not contact the first bottom surface 231, but is supported by the first bearing surface 211 that contacts the two sides of its lower surface locally.

[0034] By setting the first slot 23, the heat conduction path between the cell 40 and the carrier plate main body 10 can be increased, so that the heat during the deposition process is more evenly transferred to the surface of the cell 40, thereby improving the uniformity of the temperature distribution and enhancing the uniformity of the deposited film layer on the lower surface of the cell 40. At the same time, during the high-temperature CVD process, the cell 40 and the carrier plate main body 10 may generate certain thermal stress and deformation due to the difference in the coefficient of thermal expansion. The setting of the first slot 23 can relieve this stress and reduce the deformation of the cell 40 during the deposition process. In addition, the setting of the first slot 23 is beneficial to reducing the relative friction between the lower surface of the cell 40 and the carrier plate main body 10 during the movement process, and is convenient for the cell 40 to be detached from the carrier plate main body 10 after the deposition is completed, effectively reducing the damage to the surface of the cell 40 and facilitating subsequent cleaning, detection and other processes.

[0035] Please also refer to Figure 4 and Figure 5 , the carrier area 20 further includes at least one test piece carrier area 22. The test piece carrier area 22 is set to be recessed downward compared with the cell carrier area 21. The test piece carrier area 22 is recessed downward to form a second bearing surface 221 and a third positioning surface 222. The second bearing surface 221 is located below the carrier plate upper surface 11 and is arranged parallel to the carrier plate upper surface 11 for placing the test piece 50. The third positioning surface 222 is vertically connected between the second bearing surface 221 and the carrier plate upper surface 11 for positioning the test piece 50.

[0036] The distance from the first bearing surface 211 to the upper surface 11 of the carrier plate is less than the distance from the second bearing surface 221 to the upper surface 11 of the carrier plate. The thickness of the detection piece 50 is greater than the thickness of the battery piece 40, and the height difference between the first bearing surface 211 and the second bearing surface 221 is equal to the thickness difference between the detection piece 50 and the battery piece 40. In this way, when the detection piece 50 is placed into the detection piece bearing area 22, the height of its upper surface is the same as the height of the upper surface of the battery piece 40 placed into the battery piece bearing area 21, so that the detection piece 50 can be coated simultaneously with the production process of the battery piece 40 without an additional separate coating process or coating equipment, simplifying the film thickness detection process and improving the efficiency of film thickness detection.

[0037] The detection piece bearing area 22 is arranged near the center of the carrier plate body 10 or near the edge of the carrier plate body 10. In this embodiment, the number of detection piece bearing areas 22 is 1, and it is arranged at the edge of the carrier plate body 10, which is convenient for the loading equipment and the unloading equipment to achieve accurate positioning and picking of the detection piece 50.

[0038] As Figure 6 and Figure 7 shown, the CVD carrier plate for battery pieces of the present application further includes a gasket 30. The gasket 30 can be placed in the detection piece bearing area 22 and cooperate with the detection piece bearing area 22 to form the battery piece bearing area 21. The gasket 30 has a third bearing surface 301 for placing the battery piece 40. When the gasket 30 is placed in the detection piece bearing area 22, the bottom of the gasket 30 fits with the second bearing surface 221, and the height of the third bearing surface 301 is the same as that of the first bearing surface 211, ensuring that the upper surfaces of the battery pieces 40 on the gasket 30 and the battery pieces 40 in the battery piece bearing area 21 are at the same height. In the present application, the third bearing surface 301 is the top surface of the gasket 30, and the thickness of the gasket 30 is equal to the thickness difference between the detection piece 50 and the battery piece 40.

[0039] Further, the gasket 30 is provided with a second slot 31 located below the third bearing surface 301. The second slot 31 has a second bottom surface 311 and a fourth positioning surface 312. The second bottom surface 311 is parallel to the third bearing surface 301, and the fourth positioning surface 312 is vertically connected between the second bottom surface 311 and the third bearing surface 301. The setting of the second slot 31 makes a stepped structure formed in the gasket 30. When the battery piece 40 is placed on the gasket 30, the battery piece 40 does not contact the second bottom surface 311, but is supported by the third bearing surface 301 that contacts the two sides of its lower surface locally.

[0040] By setting the spacer 30, the switching between carrying the test piece 50 and the battery cell 40 on the test piece carrying area 22 can be achieved. When the spacer 30 is automatically placed, the test piece carrying area 22 can produce conventional battery cells 40; when the spacer 30 is automatically removed, the test piece carrying area 22 can measure the film thickness by placing the test piece 50. When there are multiple test piece carrying areas 22 provided on the carrier plate main body 10, the placement selection of the spacer 30 in each test piece carrying area 22 can be independently controlled.

[0041] This application also provides a CVD film thickness detection device, including a test piece 50, an automatic loading device, an automatic unloading device, a control device, and the battery cell CVD carrier plate as described above. During loading, the control device controls the automatic loading device to place the test piece 50 on the test piece carrying area 22 before film coating, and the test piece 50 undergoes the film coating process with the battery cell CVD carrier plate. During unloading, the control device controls the automatic unloading device to remove the test piece 50 from the test piece carrying area 22 after film coating. Further, the control device can also control the automatic picking and placing of the spacer 30.

[0042] The placement time of the test piece 50 on the carrier plate main body 10 can be programmed and controlled by means of a PLC. The film thickness condition of single or multiple film coatings can be monitored by controlling the coating times, placement time, chamber entry frequency, etc. of the test piece 50, which is beneficial for those skilled in the art to better detect the film coating situation and analyze the process equipment.

[0043] The process of CVD film thickness detection is as follows: Clean the numbered test piece 50 and prepare it for CVD loading → The control device controls the automatic loading device to place the test piece 50 on the carrier plate main body 10 → The test piece 50 is transmitted with the carrier plate main body 10 into the chamber for deposition coating → After the coating is completed, it is taken out of the chamber → The control device controls the automatic unloading device to place the test piece 50 in the post-film area to be measured → Manually measure the corresponding film thickness on the SE equipment → Analyze and monitor the operation status of the equipment according to parameters such as the measured film thickness and refractive index → Accordingly, adjust the film thickness to maintain the stability of the production line.

[0044] In this application, at least one test piece 50 is placed before each battery cell CVD carrier plate enters the chamber, and the test piece 50 is taken out after the chamber. The actual film thickness test can be selectively performed according to the stability of the recent equipment. When the stability is relatively good, sampling tests are carried out every 2 - 4 hours for monitoring. When abnormalities occur, each battery cell CVD carrier plate is tested. By analyzing the data of the test, the fluctuations can be found, and then the cause of the equipment fluctuations can be searched, so that the time point of the abnormality occurrence can be accurately located, and the equipment can be maintained and adjusted in time to improve the product yield of the battery cell 40.

[0045] The detection chip 50 of the present application is a polished silicon wafer or a glass wafer. The thickness of the detection chip 50 is 0.2 mm - 0.5 mm. Specifically, in this embodiment, the thickness of the battery chip 40 is 0.13 mm, the thickness of the detection chip 50 is 0.5 mm, and the thickness of the carrier plate body 10 is 5.5 mm. In the battery chip bearing area 21, the distance from the first bearing surface 211 to the upper surface 11 of the carrier plate is 0.5 mm, and the distance from the first bottom surface 231 to the first bearing surface 211 is 0.5 mm. In the detection chip bearing area 22, the distance from the second bearing surface 221 to the upper surface 11 of the carrier plate is 0.87 mm. The thickness of the gasket 30 is 0.37 mm, and the distance from the second bottom surface 311 to the third bearing surface 301 is 0.17 mm.

[0046] Table 1 shows the production output and efficiency status of using the battery chip CVD carrier plate of the present application (experimental group) for one month and the production of the battery chip CVD carrier plate not using the present application (control group) for one month when using CVD at 8000 pcs / h.

[0047] Table 1

[0048] Output (10,000 pieces) Efficiency (%) Control group 469.8 24.50 Experimental group 501.12 24.52

[0049] The experimental group continued production basically except for normal process adjustment and chamber cleaning time. However, in the control group, due to the inability to monitor the film thickness condition in a timely manner and the inability to adjust the process parameters in a timely manner, the process troubleshooting time and the time for daily individual film thickness testing reached as much as 45 h. Finally, the production output of the experimental group increased by 6.67% compared with the control group. At present, when the cost of heterojunction is crucial, the higher the production output, the lower the cost.

[0050] The production efficiency of the experimental group increased by 0.02% compared with the control group. The main reason is still the use of the continuous film thickness monitoring technology, which can correct the deviation in a timely manner when abnormal film thickness is found. As the core PN junction of the heterojunction, CVD has an obvious impact on the efficiency. A more stable film thickness has a more obvious gain on the efficiency.

[0051] The battery chip CVD carrier plate and CVD film thickness detection device of the present application, by simultaneously setting the battery chip bearing area 21 and the detection chip bearing area 22 on the carrier plate body 10, enables each carrier plate body 10 to transport the battery chip 40 and the detection chip 50 simultaneously, improving the detection frequency, facilitating the timely discovery of production abnormalities, and improving the yield rate of the battery chip 40. At the same time, the detection chip bearing area 22 is set to be recessed downward compared with the battery chip bearing area 21, so that the upper surfaces of the detection chip 50 and the battery chip 40 placed in the bearing area 20 are at the same height, enabling the detection chip 50 to be coated simultaneously with the production process of the battery chip 40, simplifying the film thickness detection process, and improving the film thickness detection efficiency.

[0052] The above are only the preferred embodiments of the present application, and do not impose any formal restrictions on the present application. Although the present application has been disclosed above in the preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to equivalent embodiments of equivalent changes within the scope of the technical solution of the present application by using the above-disclosed technical content. However, as long as it does not depart from the technical content of the present application, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A battery cell CVD carrier, characterized in that: It includes a carrier body and a plurality of carrying areas opened on the carrier body, wherein the plurality of carrying areas are arranged in a matrix, and the carrying areas include a plurality of battery cell carrying areas and at least one detection sheet carrying area, wherein the detection sheet carrying area is recessed downwards compared to the battery cell carrying area.

2. The cell CVD carrier according to claim 1, characterized in that: The battery cell carrying area has a first carrying surface for placing the battery cell, the detection sheet carrying area is recessed downward to form a second carrying surface for placing the detection sheet, the upper surface of the carrier is formed on the carrier body, and the distance from the first carrying surface to the upper surface of the carrier is smaller than the distance from the second carrying surface to the upper surface of the carrier.

3. The cell CVD carrier according to claim 2, characterized in that: The battery cell carrying area is further provided with a first slot located below the first carrying surface, and the first slot has a first bottom surface parallel to the first carrying surface.

4. The cell CVD carrier according to claim 2, characterized in that: It also includes a gasket, which can be placed in the detection sheet carrying area and cooperate with the detection sheet carrying area to form the battery sheet carrying area.

5. The cell CVD carrier according to claim 4, characterized in that: The gasket has a third carrying surface for placing the battery sheet. When the gasket is placed in the detection sheet carrying area, the third carrying surface is at the same height as the first carrying surface.

6. The cell CVD carrier according to claim 5, characterized in that: The gasket is provided with a second slot located below the third bearing surface, and the second slot has a second bottom surface parallel to the third bearing surface.

7. The cell CVD carrier according to claim 2, characterized in that: The battery cell carrying area also has a first positioning surface vertically connected between the first carrying surface and the upper surface of the carrier; the detection piece carrying area also has a third positioning surface vertically connected between the second carrying surface and the upper surface of the carrier.

8. The cell CVD carrier according to claim 1, characterized in that: The detection sheet carrying area is arranged close to the center of the carrier body or close to the edge of the carrier body.

9. A CVD film thickness detection device, characterized in that: It includes a detection sheet, an automatic loading device, an automatic unloading device, a control device and a battery cell CVD carrier as described in any one of claims 1 to 8; the control device is used to control the automatic loading device to place the detection sheet on the detection sheet carrying area before coating and to control the automatic unloading device to remove the detection sheet from the detection sheet carrying area after coating.

10. The CVD film thickness detection device according to claim 9, characterized in that: The detection sheet is a polished silicon sheet or a glass sheet; the thickness of the detection sheet is 0.2mm-0.5mm.

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