A rapid chain annealing apparatus

Abstract

The application provides a rapid chain annealing device for annealing silicon wafers, which comprises a front transition zone, a temperature rising zone, a constant temperature zone, a temperature falling zone, a rear transition zone and a transmission shaft, the transmission shaft passes through the zones in sequence in the horizontal direction, and the silicon wafers pass through the zones in sequence on the transmission shaft to complete the annealing process. A second heating device is arranged at the bottom of the constant temperature zone, and a light source device is arranged at the top of the constant temperature zone, the second heating device heats the silicon wafers, the light source device provides light for the silicon wafers to further heat the silicon wafers, and a unidirectional light transmission and heat insulation material layer is arranged below the light source device to reduce the light reflection in the constant temperature zone and keep the temperature stable. After the above technical scheme is adopted, the heating device and the light source device can be combined to rapidly heat the silicon wafers, reduce the negative influence of high-temperature process time on the silicon wafers, and reduce the light reflection in the constant temperature zone to keep the temperature stable.

Description

Technical Field

[0001] This invention relates to the field of solar cells, and more particularly to a rapid chain annealing apparatus. Background Technology

[0002] With the rapid iteration of battery technology and the booming development of the photovoltaic industry, crystalline silicon solar cell technology is constantly being updated, and conversion efficiency is gradually breaking records. New battery structures and technologies, such as top-con, HJT, and perovskite, are also quickly becoming the focus of research and development. In existing top-con technology, the preparation of a polycrystalline silicon field passivation layer on silicon wafers requires high-temperature annealing. If the temperature rise rate of the silicon wafer is too slow and the annealing process takes too long, prolonged heating may cause film decomposition on the silicon wafer surface, affecting the preparation effect. Summary of the Invention

[0003] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide a rapid chain annealing device for heating silicon wafers and performing annealing treatment in a very short time.

[0004] This invention discloses a rapid chain annealing device, including a pre-transition zone, a heating zone, a constant temperature zone, a cooling zone, a post-transition zone, and a transmission shaft. The transmission shaft passes through each of the above zones in a horizontal direction. The silicon wafer is transported on the transmission shaft from the feed end to the discharge end of the transmission shaft, so that the silicon wafer passes through each of the above zones in sequence to complete the annealing process.

[0005] The front transition zone is a cavity used to isolate the feed end of the transmission shaft;

[0006] A first heating device is provided at the bottom of the heating zone for preheating the silicon wafer;

[0007] A second heating device is provided at the bottom of the constant temperature zone, and a light source device is provided at the top. The second heating device heats the silicon wafer at a higher temperature than the first heating device, so as to heat the silicon wafer. The light source device provides light to the silicon wafer to further heat it up. A one-way transparent heat-insulating material layer is also provided between the light source device and the transmission shaft to reduce light reflection in the constant temperature zone and maintain temperature stability.

[0008] A third heating device is provided at the bottom of the cooling zone. The heating temperature of the silicon wafer by the third heating device is lower than that of the silicon wafer by the second heating device, and it is used to cool the silicon wafer.

[0009] The post-transition zone is a cavity used to cool the silicon wafer.

[0010] Preferably, the material of the one-way light-transmitting heat-insulating material layer is quartz material with a silver film or aluminum film coated underneath.

[0011] Preferably, the second heating device includes a plurality of infrared lamps and a flow equalization plate disposed below the plurality of infrared lamps. The flow equalization plate has a plurality of air outlets located below the gaps between the plurality of infrared lamps.

[0012] When the multiple infrared lamps are heated, inert gas is uniformly introduced into the constant temperature zone through the multiple air outlets. The inert gas carries the heat generated by the multiple infrared lamps to the silicon wafer, so as to rapidly and uniformly heat the silicon wafer.

[0013] Preferably, a first air extraction device is provided at the top of the front transition zone, and the first air extraction device connects the front transition zone with the external environment;

[0014] A second air extraction device is provided at the top of the rear transition zone, and the second air extraction device connects the rear transition zone with the external environment.

[0015] The first extraction device extracts air from the front transition zone to the external environment, and the second extraction device extracts air from the rear transition zone to the external environment, so that the inert gas introduced into the constant temperature zone gradually flows to the top of the front and rear transition zones to maintain the stability of the temperature and pressure in the constant temperature zone.

[0016] Preferably, the third heating device includes a front section near the constant temperature zone and a rear section near the rear transition zone. The heating temperature of the silicon wafer by the front section is higher than that of the silicon wafer by the rear section, so as to gradually cool down the silicon wafer and avoid affecting the temperature stability within the constant temperature zone.

[0017] Preferably, an inert gas is introduced into the post-transition zone to purge the silicon wafer, thereby cooling the wafer and ensuring it is fully cooled when it reaches the discharge end.

[0018] Preferably, a ceramic fiber plate is placed on the transmission shaft to carry the silicon wafer, thereby preventing frictional damage to the silicon wafer on the transmission shaft.

[0019] Preferably, the heating temperature of the silicon wafer by the first heating device is 800°C.

[0020] Preferably, the second heating device heats the silicon wafer at a temperature of 1000°C.

[0021] Preferably, the heating temperature of the silicon wafer by the third heating device is 30℃~800℃.

[0022] Compared with existing technologies, the above technical solution has the following advantages:

[0023] 1. By combining heating devices and light source devices, the silicon wafers can be heated up quickly, reducing the negative impact of high-temperature processing time on the silicon wafers;

[0024] 2. A one-way light-transmitting heat-insulating material layer is used to reduce light reflection in the constant temperature zone and maintain a stable temperature within the zone;

[0025] 3. By setting up a flow equalization plate and a vacuum system, a heat flow is formed in the annealing equipment cavity, which can quickly and evenly heat the silicon wafer, maintain a stable temperature in the constant temperature zone, and isolate oxygen from entering the constant temperature zone, thus avoiding the negative impact of oxygen on the silicon wafer. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a rapid chain annealing device disclosed in this invention;

[0027] Figure 2 This is a schematic diagram of the constant temperature zone in a rapid chain annealing device disclosed in this invention;

[0028] Figure 3 This is a top view schematic diagram of the second heating device in a rapid chain annealing equipment disclosed in this invention;

[0029] Figure 4 This is a schematic diagram of the structure of a rapid chain annealing device disclosed in this invention. Detailed Implementation

[0030] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0031] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0032] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0033] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0034] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0035] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0036] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0037] See Figures 1-4 As shown, the present invention discloses a rapid chain annealing device, including a pre-transition zone, a heating zone, a constant temperature zone, a cooling zone, a post-transition zone, and a transmission shaft. The transmission shaft passes through the above zones sequentially in a horizontal direction. The silicon wafer is transported on the transmission shaft from the feed end of the transmission shaft to the discharge end of the transmission shaft, so that the silicon wafer passes through the above zones sequentially to complete the annealing process.

[0038] The front transition zone is a cavity used to isolate the feed end of the transmission shaft;

[0039] A first heating device is provided at the bottom of the heating zone for preheating the silicon wafer;

[0040] A second heating device is provided at the bottom of the constant temperature zone, and a light source device is provided at the top. The second heating device heats the silicon wafer at a higher temperature than the first heating device, so as to heat the silicon wafer. The light source device provides light to the silicon wafer to further heat it up. A one-way transparent heat-insulating material layer is also provided between the light source device and the transmission shaft to reduce light reflection in the constant temperature zone and maintain temperature stability.

[0041] A third heating device is provided at the bottom of the cooling zone. The heating temperature of the silicon wafer by the third heating device is lower than that of the silicon wafer by the second heating device, and it is used to cool the silicon wafer.

[0042] The post-transition zone is a cavity used to cool the silicon wafer.

[0043] Specifically, the pre-transition zone is a cavity used to transition the feed end of the transfer shaft, isolating the heating devices in subsequent zones from the silicon wafer located at the feed end to prevent mutual interference. The heating zone preheats the silicon wafer and maintains temperature stability within the constant-temperature zone. The constant-temperature zone is the main process area, heated by a second heating device, with a light source assisting in further heating of the silicon wafer, allowing it to reach the rated annealing temperature in a short time. Furthermore, a one-way transparent heat-insulating material layer is laid below the light source device, allowing light from the light source to pass through and illuminate the silicon wafer, while reducing light reflection from the constant-temperature zone to the outside, avoiding energy loss and maintaining temperature stability within the constant-temperature zone. The cooling zone cools the silicon wafer. The post-transition zone is also a cavity used to transition the discharge end of the transfer shaft, further cooling the silicon wafer before discharge.

[0044] Preferably, the material of the one-way light-transmitting heat-insulating material layer is quartz material with a silver film or aluminum film coated underneath.

[0045] Preferably, see Figures 2-3 As shown, the second heating device includes a plurality of infrared lamps and a flow equalization plate disposed below the plurality of infrared lamps. The flow equalization plate has a plurality of air outlets located below the gaps between the plurality of infrared lamps.

[0046] When the multiple infrared lamps are heated, inert gas is uniformly introduced into the constant temperature zone through the multiple air outlets. The inert gas carries the heat generated by the multiple infrared lamps to the silicon wafer, so as to rapidly and uniformly heat the silicon wafer.

[0047] Specifically, the flow equalizer provides uniform airflow between multiple infrared lamps, carrying heat from the vicinity of the lamps to the silicon wafer on the transmission shaft, forming a heat flow for rapid heating of the wafer. Furthermore, by introducing an inert gas, oxygen is prevented from entering the constant-temperature zone, avoiding its interference with the annealing process and thus preventing the formation of recombination centers on the wafer surface.

[0048] Preferably, see Figure 4 As shown, a first air extraction device is provided at the top of the front transition zone, and the first air extraction device connects the front transition zone with the external environment.

[0049] A second air extraction device is provided at the top of the rear transition zone, and the second air extraction device connects the rear transition zone with the external environment.

[0050] The first extraction device extracts air from the front transition zone to the external environment, and the second extraction device extracts air from the rear transition zone to the external environment, so that the inert gas introduced into the constant temperature zone gradually flows to the top of the front and rear transition zones to maintain the stability of the temperature and pressure in the constant temperature zone.

[0051] Preferably, the third heating device includes a front section near the constant temperature zone and a rear section near the rear transition zone. The heating temperature of the silicon wafer by the front section is higher than that of the silicon wafer by the rear section, so as to gradually cool down the silicon wafer and avoid affecting the temperature stability within the constant temperature zone.

[0052] Specifically, the third heating device can be configured into multiple parts along the horizontal direction, with the heating temperature gradually decreasing from the part near the constant temperature zone to the part near the rear transition zone, thereby achieving gradual cooling of the silicon wafer. Furthermore, the heating temperature of the part near the constant temperature zone in the rear transition zone is relatively high, with a small temperature difference from the constant temperature zone, thus avoiding temperature fluctuations in the constant temperature zone.

[0053] Preferably, an inert gas is introduced into the post-transition zone to purge the silicon wafer, thereby cooling the wafer and ensuring it is fully cooled when it reaches the discharge end.

[0054] Preferably, a ceramic fiber plate is placed on the transmission shaft to carry the silicon wafer, thereby preventing frictional damage to the silicon wafer on the transmission shaft.

[0055] Preferably, the heating temperature of the silicon wafer by the first heating device is 800°C.

[0056] Preferably, the second heating device heats the silicon wafer at a temperature of 1000°C.

[0057] Preferably, the heating temperature of the silicon wafer by the third heating device is 30℃~800℃.

[0058] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A rapid chain annealing apparatus for annealing silicon wafers, characterized in that, It includes a pre-transition zone, a heating zone, a constant temperature zone, a cooling zone, a post-transition zone, and a transmission shaft. The transmission shaft passes through each of the above zones in a horizontal direction. The silicon wafer is transported on the transmission shaft from the feed end to the discharge end of the transmission shaft, so that the silicon wafer passes through each of the above zones in sequence to complete the annealing process. The front transition zone is a cavity used to isolate the feed end of the transmission shaft; A first heating device is provided at the bottom of the heating zone for preheating the silicon wafer; A second heating device is provided at the bottom of the constant temperature zone, and a light source device is provided at the top. The second heating device heats the silicon wafer at a higher temperature than the first heating device, so as to heat the silicon wafer. The light source device provides light to the silicon wafer to further heat it up. A one-way transparent heat-insulating material layer is also provided between the light source device and the transmission shaft to reduce light reflection in the constant temperature zone and maintain temperature stability. A third heating device is provided at the bottom of the cooling zone. The heating temperature of the silicon wafer by the third heating device is lower than that of the silicon wafer by the second heating device, and it is used to cool the silicon wafer. The post-transition zone is a cavity used to cool the silicon wafer.

2. The rapid chain annealing equipment according to claim 1, characterized in that, The material of the one-way light-transmitting heat-insulating material layer is quartz material with a silver or aluminum film plated on the bottom surface facing the transmission axis.

3. The rapid chain annealing equipment according to claim 1, characterized in that, The second heating device includes a plurality of infrared lamps and a flow equalization plate disposed below the plurality of infrared lamps. The flow equalization plate has a plurality of air outlets located below the gaps between the plurality of infrared lamps. When the multiple infrared lamps are heated, inert gas is uniformly introduced into the constant temperature zone through the multiple air outlets. The inert gas carries the heat generated by the multiple infrared lamps to the silicon wafer, so as to rapidly and uniformly heat the silicon wafer.

4. The rapid chain annealing equipment according to claim 3, characterized in that, A first air extraction device is provided at the top of the front transition zone, and the first air extraction device connects the front transition zone with the external environment. A second air extraction device is provided at the top of the rear transition zone, and the second air extraction device connects the rear transition zone with the external environment. The first extraction device extracts air from the front transition zone to the external environment, and the second extraction device extracts air from the rear transition zone to the external environment, so that the inert gas introduced into the constant temperature zone gradually flows to the top of the front and rear transition zones to maintain the stability of the temperature and pressure in the constant temperature zone.

5. The rapid chain annealing equipment according to claim 1, characterized in that, The third heating device includes a front section near the constant temperature zone and a rear section near the rear transition zone. The heating temperature of the silicon wafer by the front section is higher than that of the silicon wafer by the rear section, so as to gradually cool down the silicon wafer and avoid affecting the temperature stability within the constant temperature zone.

6. The rapid chain annealing equipment according to claim 1, characterized in that, An inert gas is introduced into the post-transition zone to purge the silicon wafer, thereby cooling the wafer and ensuring it is fully cooled before reaching the discharge end.

7. The rapid chain annealing equipment according to claim 1, characterized in that, A ceramic fiber plate is placed on the transmission shaft to carry the silicon wafer, thus preventing frictional damage to the silicon wafer on the transmission shaft.

8. The rapid chain annealing equipment according to claim 1, characterized in that, The first heating device heats the silicon wafer at a temperature of 800°C.

9. The rapid chain annealing equipment according to claim 1, characterized in that, The second heating device heats the silicon wafer at a temperature of 1000°C.

10. The rapid chain annealing equipment according to claim 1, characterized in that, The third heating device heats the silicon wafer at a temperature of 30°C to 800°C.

Images