Sample loading system for synchronous thermal analysis of photovoltaic cell silver paste

Abstract

The utility model relates to the field of material thermal analysis, in particular to a sample loading system for synchronous thermal analysis of photovoltaic cell silver paste, which comprises a partition module and a blowing module, the partition module is of a cylindrical structure with openings in the two ends, the partition module is arranged in the crucible, and photovoltaic cell silver paste to be analyzed enters the crucible through the openings in the two ends of the partition module; and the blowing module is used for flattening the photovoltaic cell silver paste to be analyzed in the crucible in a blowing manner. According to the utility model, the blocking module is used for preventing the side wall of the crucible from being accidentally stained when STA analysis sample loading is carried out on the photovoltaic cell silver paste. And the blowing module sprays gas with proper force, so that the silver paste is uniformly distributed in the accommodating body and flatly laid at the bottom of the crucible. Further, the temperature difference of different parts of the sample in test analysis is reduced, more accurate thermal reaction temperature is obtained, the consistency of thermal analysis curve shapes is improved, and the research of photovoltaic cell silver paste sintering and photovoltaic cell preparation processes is effectively supported.

Description

Technical Field

[0001] The utility model relates to the field of material thermal analysis, and particularly relates to a sample loading system for synchronous thermal analysis of photovoltaic cell silver paste. Background Technique

[0002] Photovoltaic solar cells utilize the photovoltaic effect of semiconductor PN junctions to generate photoelectric conversion, and the formed charges are collected by the grid lines on the cell surface and then transmitted. Photovoltaic cell silver paste is the material for preparing the cell grid lines, and its quality directly affects the performance and lifespan of photovoltaic modules. The grid line preparation process is to coat photovoltaic cell silver paste on the cell by screen printing and then sinter it. Therefore, the research on the thermal behavior of the photovoltaic cell silver paste sintering process has become the focus of the research on the photovoltaic cell preparation process. The technical means for researching the thermal behavior of photovoltaic cell silver paste sintering mainly include TG, DSC, or synchronous thermal analysis technology (STA) based on the combination of TG and DSC. Before these thermal analyses are carried out, the photovoltaic cell silver paste needs to be loaded into a crucible that is配套 with the instrument equipment. The crucible is generally made of materials such as aluminum and alumina, and is in the shape of a cylinder or a frustum of a cone, with an inner diameter usually around 5 mm. According to the different depths of the crucible, it can be divided into shallow dish crucibles and cylindrical crucibles. During the test, the sample temperature is obtained through the comprehensive processing of the furnace body temperature and the thermal sensor in contact with the crucible. Therefore, there are differences in the reaction degrees of the samples at different positions in the crucible. The thickness and heat capacity of the sample will affect the temperature gradient between the crucible wall and the sample.

[0003] Therefore, in order to obtain more reliable thermal analysis results, the silver paste sample after being placed in the crucible should be laid flat on the bottom of the crucible as much as possible. However, due to the high viscosity of the photovoltaic cell silver paste, after using conventional tools such as sample spoons and tweezers to pick up an appropriate amount of silver paste and put it into the crucible, the morphology of the silver paste is usually extremely irregular and cannot be laid flat on the bottom of the crucible. At the same time, due to operational errors, the silver paste may accidentally stick to the side wall of the crucible, and even some silver paste may stick outside the crucible. When taking out the sample loading tool, the sample may have a spiky morphology due to the silver paste sticking to the sample loading tool. This will have a significant impact on the accuracy and repeatability of the test analysis. Therefore, how to lay the silver paste sample flat on the bottom of the crucible while avoiding the silver paste accidentally sticking to the side wall of the crucible is a current research direction. Content of the Utility Model

[0004] (I) Purpose of the Utility Model

[0005] The purpose of the utility model is to provide a sample loading system for synchronous thermal analysis of photovoltaic cell silver paste that can solve the problems that the silver paste cannot be laid flat on the bottom of the crucible and has a spiky morphology when performing STA thermal analysis on the photovoltaic cell silver paste.

[0006] (II) Technical Solution

[0007] To address the aforementioned issues, this invention provides a sample loading system for simultaneous thermal analysis of silver paste in photovoltaic cells, comprising: a baffle module and a leveling module;

[0008] The separator module is configured as a cylindrical structure with openings at both ends. The separator module is placed inside the crucible, and the photovoltaic cell silver paste to be analyzed enters the crucible through the openings at both ends of the separator module.

[0009] The leveling module includes a gas container unit, a gas flow regulation unit, a connection unit, and a jetting unit;

[0010] The gas container unit is connected to the gas flow regulating unit;

[0011] The gas flow regulating unit is connected to the jet unit via the connecting unit;

[0012] The gas container unit is used to hold the gas to be injected.

[0013] The gas flow regulating unit is used to regulate the pressure of the injected gas;

[0014] The jetting unit sprays gas to smooth the silver paste from the photovoltaic cells to be analyzed inside the crucible.

[0015] In another aspect of this utility model, preferably,

[0016] The partition module is made of aluminum foil.

[0017] The outer diameter of the partition module is smaller than the inner diameter of the crucible.

[0018] In another aspect of this utility model, preferably,

[0019] The depth of the partition module is greater than the depth of the crucible.

[0020] In another aspect of this utility model, preferably,

[0021] The gas container unit includes a body and a gas inlet;

[0022] The main body is used to hold the gas to be injected;

[0023] The air inlet is connected to the main body and is used for the entry and exit of gas;

[0024] The air inlet is connected to the gas flow regulating unit.

[0025] In another aspect of this utility model, preferably,

[0026] The gas flow regulating unit is a pressure reducing valve;

[0027] One end of the pressure reducing valve is connected to the air port, and the other end of the pressure reducing valve is connected to the connecting unit.

[0028] In another aspect of this utility model, preferably,

[0029] The pressure regulating range of the pressure reducing valve is 0.1MPa to 0.5MPa.

[0030] In another aspect of this utility model, preferably, the connecting unit is a flexible hose;

[0031] One end of the hose is connected to the pressure reducing valve, and the other end of the hose is connected to the jet unit.

[0032] In another aspect of this utility model, preferably,

[0033] The jet unit includes a connecting end and a nozzle end;

[0034] The connecting end is connected to the hose, and the nozzle end sprays gas to smooth the photovoltaic cell silver paste to be analyzed in the crucible.

[0035] In another aspect of this invention, preferably, the cross-sectional shape of the nozzle end is circular, and the inner diameter of the nozzle end cross-section is less than or equal to 1 mm.

[0036] In another aspect of this utility model, preferably,

[0037] The connecting end is detachably connected to the hose.

[0038] (III) Beneficial Effects

[0039] The above-mentioned technical solution of this utility model has the following beneficial technical effects:

[0040] This invention utilizes a partition module to prevent accidental contamination of the crucible sidewalls during STA (Synthetic Analysis) sample loading of photovoltaic (PV) silver paste, ensuring accurate entry of the paste into the crucible bottom. The gas container unit, gas flow regulation unit, connection unit, and jetting unit within the leveling module work in concert. The gas flow regulation unit controls the pressure of the injected gas, allowing the jetting unit to inject gas with precise force based on the actual state of the silver paste and the crucible's dimensions. This ensures the silver paste is evenly distributed and evenly spread on the bottom of the crucible. This reduces temperature differences between different parts of the sample during testing and analysis, resulting in more accurate thermal reaction temperatures, improved consistency of the thermal analysis curve shape, and effective support for research on PV silver paste sintering and PV cell fabrication processes. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the overall structure of one embodiment of the present utility model;

[0042] Figure 2 This is an initial morphology diagram of a sample of silver paste placed in a crucible according to an embodiment of this utility model;

[0043] Figure 3 This is a morphological image of the sample placed in the crucible after being swept by a leveling device in a specific embodiment of this application;

[0044] Figure label:

[0045] 1: Divider module

[0046] 2: Leveling module; 210: Gas container unit; 211: Body; 212: Air port; 220: Gas flow regulation unit; 230: Connection unit; 240: Jet unit; 241: Connection end; 242: Nozzle end. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0048] The accompanying drawings show structural schematic diagrams according to embodiments of the present invention. These drawings are not drawn to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0049] Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0050] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0051] The present invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the parts in the drawings are not drawn to scale.

[0052] Example 1

[0053] A sample loading system for simultaneous thermal analysis of silver paste in photovoltaic cells. Figure 1 A schematic diagram of the overall structure of one embodiment of the present invention is shown, as follows: Figure 1 As shown, it includes: a partition module 1 and a leveling module 2;

[0054] The separator module 1 is configured as a cylindrical structure with openings at both ends. The separator module 1 is placed inside the crucible, and the photovoltaic cell silver paste to be analyzed enters the crucible through the openings at both ends of the separator module 1. In this embodiment, the separator module 1 is made of aluminum foil. The outer diameter of the separator module 1 is smaller than the inner diameter of the crucible to ensure that the separator module 1 can be placed inside the crucible. The depth of the separator module 1 is 1-3 mm greater than the depth of the crucible, which is beneficial for using tweezers to pick out the separator module 1, while avoiding the separator module 1 being too high and causing difficulties in sample loading. Before placing the photovoltaic cell silver paste into the crucible using conventional sample loading tools, the partition module 1 is placed inside the crucible, and then the silver paste is adhered to the bottom of the crucible using conventional sample loading tools. At this time, the silver paste has a very irregular morphology, a large thickness, and a spike-like morphology. During the transfer of the silver paste, the partition module 1 plays an effective limiting role, preventing unnecessary splashing and contamination of the crucible sidewalls when the silver paste enters the crucible, and ensuring that the silver paste can be accurately placed at the predetermined position at the bottom of the crucible, providing a reliable sample basis for subsequent thermal analysis experiments.

[0055] The leveling module 2 uses air blowing to level the photovoltaic cell silver paste to be analyzed in the crucible. The leveling module 2 includes a gas container unit 210, a gas flow regulation unit 220, a connection unit 230, and an air jet unit 240. The gas container unit 210 is connected to the gas flow regulation unit 220. The gas flow regulation unit 220 is connected to the air jet unit 240 through the connection unit 230. The gas container unit 210 is used to hold the gas to be sprayed. The gas flow regulation unit 220 is used to regulate the pressure of the sprayed gas. The air jet unit 240 sprays gas to level the photovoltaic cell silver paste to be analyzed in the crucible.

[0056] Gas container unit 210, serving as the gas supply station for the entire leveling operation, has sufficient capacity to hold the gas to be injected. The selected gas is typically an inert gas that has no adverse effects on the silver paste and the experimental environment, such as high-purity nitrogen or argon. This ensures that no additional impurities or chemical reactions are introduced during the leveling process, guaranteeing the purity and accuracy of the thermal analysis experiment. Gas flow regulation unit 220 can adjust the gas pressure output from gas container unit 210. By adjusting the pressure parameters, the gas flow rate and impact force ejected from jet unit 240 can be precisely controlled, effectively propelling the silver paste within the crucible without causing splashing or scattering due to excessive gas force, thus achieving a smooth spread of the silver paste at the bottom of the crucible. Connection unit 230, serving as the gas transmission channel, is made of materials with good airtightness and flexibility, such as high-temperature resistant silicone tubing or high-quality plastic hoses, ensuring that no gas leakage occurs during the transmission from gas flow regulation unit 220 to jet unit 240, guaranteeing the stability and continuity of the leveling operation. The jet unit 240 has a suitable nozzle diameter and shape, such as a circular or flat nozzle, to generate uniform pressure on the surface of the silver paste, thereby spreading the silver paste evenly and forming a sample layer with uniform thickness and a smooth surface within the crucible. The leveling module 2, after setting a reasonable gas pressure, blows the silver paste, enabling it to spread along the bottom of the crucible, reducing sample thickness and eliminating sharp spikes. Even if some silver paste accidentally adheres to the partition module 1 after blowing, removing the partition module 1 with tweezers prevents the silver paste from directly adhering to the crucible sidewall.

[0057] Furthermore, in this embodiment, the gas container unit 210 includes a body 211 and a gas inlet 212; the body 211 is used to hold the gas to be injected; the gas to be injected is an inert gas, which can prevent the gas from directly reacting chemically or physically with the silver paste. The body 211 is a gas cylinder, which is inexpensive and has a low cost. The gas inlet 212 is connected to the body 211; the gas inlet 212 is used for gas to enter and exit; the gas inlet 212 is connected to the gas flow regulating unit 220.

[0058] The gas flow regulating unit 220 is a pressure reducing valve; one end of the pressure reducing valve is connected to the gas port 212, and the other end is connected to the connecting unit 230. The pressure regulating range of the pressure reducing valve is 0.1MPa to 0.5MPa. The pressure reducing valve controls the pressure of the ejected gas. If the gas pressure is too high, the silver paste will easily be blown out of the crucible; if the gas pressure is too low, it will be difficult to agitate the silver paste to adjust its morphology within the crucible. The pressure within the regulating range in this embodiment can make the morphology of the silver paste within the crucible smooth.

[0059] The connecting unit 230 is a flexible hose; one end of the plastic hose is connected to the pressure reducing valve, and the other end of the hose is connected to the jet unit. The hose is made of plastic, which is resistant to corrosion and prevents corrosive substances from contaminating the silver paste with the gas.

[0060] The jetting unit 240 includes a connecting end 241 and a nozzle end 242. The connecting end 241 is connected to the plastic hose, and the nozzle end 242 jets gas to smooth the photovoltaic cell silver paste to be analyzed in the crucible. The nozzle end 242 has a circular cross-sectional shape, and its inner diameter is less than or equal to 1 mm. The connecting end 241 and the plastic hose are detachably connected. An excessively large inner diameter of the nozzle end 242 reduces the effect of the purging gas on adjusting the local shape of the silver paste; an inner diameter of less than or equal to 1 mm allows for adjustment of the detailed morphology of the silver paste, achieving uniform spreading of the silver paste along the bottom of the crucible.

[0061] Furthermore, in this embodiment, the sample crucible is an alumina crucible compatible with the German Netzsch 449-F3 synchronous thermal analyzer. The partition module 1 is made of aluminum foil and can be placed inside the alumina crucible, fitting snugly against its inner wall. The leveling module 2 consists of a nitrogen cylinder (gas container unit 210), a nitrogen pressure reducing valve (gas flow regulating unit 220), a 2m long plastic tubing (connecting unit 230), and an air jet unit 240. The air jet unit 240 comprises a medical syringe barrel and a needle. The syringe barrel has an inner diameter of approximately 12mm and an internal volume of approximately 10mL; the needle has an inner diameter of approximately 0.5mm, and the gas outlet face of the needle is a flat, circular end face, obtained by cutting off the sharp part of the needle along its cross-section. The connection between the air jet unit 240 and the plastic tubing is as follows: a sealing tape is wrapped around the plastic tubing, the sealed plastic tubing is then inserted into the syringe, and the syringe barrel and tubing are then wrapped around from the outside to achieve a reinforced connection.

[0062] The sample loading steps include:

[0063] S1. Use tweezers to place the partition module 1 into the alumina crucible.

[0064] S2. Use tweezers to pick up an appropriate amount of silver paste, then use the tip of a soft plastic needle to pick up an appropriate amount of silver paste from the tweezers, carefully put it into the crucible and let the silver paste stick to the bottom of the crucible. Figure 2 This diagram shows the initial morphology of a sample of silver paste placed in a crucible according to an embodiment of the present invention; as shown. Figure 2 The image shows the morphology of the silver paste sample in the crucible at this time.

[0065] S3. Open the nitrogen cylinder valve and adjust the pressure reducing valve to approximately 0.15 MPa. Blow the silver paste through the 240mm nozzle of the jet unit until the silver paste sample is evenly distributed across the bottom of the crucible and of uniform thickness. During the blowing process, try to prevent the silver paste from sticking to the separator module.

[0066] S4. Use tweezers to hold the partition module and remove it. Figure 3 This invention illustrates the morphology of a sample placed in a crucible after being swept by a leveling device according to a specific embodiment of this application; as shown. Figure 3 The image shows the morphology of the silver paste sample in the crucible at this time.

[0067] contrast Figure 2 and Figure 3 As can be seen, using the sample loading system of this embodiment, the photovoltaic cell silver paste sample placed in the crucible can be fully spread on the bottom of the crucible, eliminating obvious spike morphology, and the thickness uniformity is significantly improved.

[0068] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

[0069] The above description does not provide detailed explanations of the technical aspects of each layer's patterning and etching. However, those skilled in the art should understand that various methods existing in the prior art can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above.

[0070] The present invention has been described above with reference to embodiments thereof. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the present invention, and all such substitutions and modifications should fall within the scope of the present invention.

[0071] Although the embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and modifications can be made to the embodiments of the present invention without departing from the spirit and scope of the present invention.

[0072] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A sample loading system for simultaneous thermal analysis of silver paste in photovoltaic cells, characterized in that, include: The partition module (1) and the leveling module (2); The partition module (1) is a cylindrical structure with openings at both ends. The partition module (1) is placed inside the crucible. The photovoltaic cell silver paste to be analyzed enters the crucible through the openings at both ends of the partition module (1). The leveling module (2) includes a gas container unit (210), a gas flow regulation unit (220), a connection unit (230), and a jet unit (240); The gas container unit (210) is connected to the gas flow regulating unit (220); the gas flow regulating unit (220) is connected to the jet unit (240) through the connecting unit (230); The gas container unit (210) is used to hold the gas to be injected; The gas flow regulating unit (220) is used to regulate the pressure of the injected gas; The jetting unit (240) injects gas to smooth the photovoltaic cell silver paste to be analyzed in the crucible.

2. The sample loading system according to claim 1, characterized in that, The partition module (1) is made of aluminum foil; The outer diameter of the partition module (1) is smaller than the inner diameter of the crucible.

3. The sample loading system according to claim 2, characterized in that, The depth of the partition module (1) is greater than the depth of the crucible.

4. The sample loading system according to claim 1, characterized in that, The gas container unit (210) includes a body (211) and a gas inlet (212); The body (211) is used to hold the gas to be injected; The air inlet (212) is connected to the main body (211) and is used for the intake and exhaust of gas; The air inlet (212) is connected to the gas flow regulating unit (220).

5. The sample loading system according to claim 4, characterized in that, The gas flow regulating unit (220) is a pressure reducing valve; One end of the pressure reducing valve is connected to the air port (212), and the other end of the pressure reducing valve is connected to the connecting unit (230).

6. The sample loading system according to claim 5, characterized in that, The pressure regulating range of the pressure reducing valve is 0.1MPa to 0.5MPa.

7. The sample loading system according to claim 5, characterized in that, The connecting unit (230) is a flexible hose; One end of the hose is connected to the pressure reducing valve, and the other end of the hose is connected to the jet unit.

8. The sample loading system according to claim 7, characterized in that, The jet unit (240) includes a connecting end (241) and a nozzle end (242); The connecting end (241) is connected to the hose, and the nozzle end (242) sprays gas to smooth the photovoltaic cell silver paste to be analyzed in the crucible.

9. The sample loading system according to claim 8, characterized in that, The nozzle end (242) has a circular cross-sectional shape, and the inner diameter of the nozzle end (242) is less than or equal to 1 mm.

10. The sample loading system according to claim 8, characterized in that, The connecting end (241) is detachably connected to the hose.

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