Gas supply system and solar cell diffusion junction making system

Abstract

The utility model relates to a gas supply system and a solar cell diffusion junction making system. The system comprises: a source bottle placed in a thermostatic bath; the standby source bottle is placed in the standby thermostatic bath; the source bottle and the standby source bottle are both filled with active liquid; the gas supply device is used for introducing gas into the source liquid in the source bottle or the source liquid in the standby source bottle; the liquid level detection device is used for detecting the liquid level of source liquid in the source bottle to obtain liquid level information; the liquid level detection device is arranged in the thermostatic bath; the control device is used for controlling the gas supply device to introduce gas into the source bottle under the condition that the liquid level information does not meet the liquid shortage condition; the control device further controls the gas supply device to introduce gas into the standby source bottle under the condition that the liquid level information meets the liquid shortage condition. By adopting the system, the stability of diffusion junction preparation can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cell manufacturing, and particularly to a gas supply system and a diffusion junction formation system for solar cells. Background Art

[0002] With the development of solar cell manufacturing technology, a diffusion junction formation technology has emerged. An N-type silicon wafer is placed in a furnace tube, and a gas containing P-type impurity atoms is introduced into the furnace tube to form a PN junction, so that a diffusion layer is formed on the surface of the solar cell, improving the performance of the solar cell.

[0003] In traditional diffusion junction formation technology, phosphorus oxychloride is generally used as the source liquid for the introduced gas. After the source liquid is reduced to a certain amount during use, the source liquid needs to be taken out and replaced with a new source liquid to ensure the normal progress of the diffusion junction formation process. However, during the process of replacing the new source liquid, since the temperature of the new source liquid is inconsistent with that of the source liquid, the stability of the diffusion junction formation process will be reduced, and the diffusion junction formation process may fail. Summary of the Utility Model

[0004] Based on this, it is necessary to provide a gas supply system and a diffusion junction formation system for solar cells that can improve the stability of the diffusion junction formation process in view of the above technical problems.

[0005] In a first aspect, the present application provides a gas supply system, including:

[0006] A source bottle placed in a constant temperature bath;

[0007] A spare source bottle placed in a spare constant temperature bath; both the source bottle and the spare source bottle are filled with source liquid;

[0008] A gas supply device for introducing gas into the source liquid in the source bottle or the source liquid in the spare source bottle;

[0009] A liquid level detection device for detecting the liquid level of the source liquid in the source bottle to obtain liquid level information; the liquid level detection device is arranged in the constant temperature bath;

[0010] A control device for controlling the gas supply device to introduce gas into the source bottle when the liquid level information does not meet the liquid shortage condition; the control device also controls the gas supply device to introduce gas into the spare source bottle when the liquid level information meets the liquid shortage condition.

[0011] In one embodiment, the constant temperature bath includes a temperature detection device and a heating device; the temperature detection device and the heating device are connected to the control device.

[0012] In one embodiment, the source bottle is provided with a detection hole, and at least a part of the hole wall of the detection hole is in contact with the source liquid; the temperature detection device includes a temperature sensing unit; the temperature sensing unit is disposed in the detection hole.

[0013] In one embodiment, the liquid level detection device includes at least two liquid level detection units; each of the liquid level detection units is respectively connected to the control device.

[0014] In one embodiment, each of the liquid level detection units is arranged along the height direction.

[0015] In one embodiment, the gas supply system further includes a gas supply device;

[0016] The gas supply device is connected to the source bottle and the spare source bottle to form a bubbling device.

[0017] In one embodiment, the gas supply system further includes a first gas pipeline and a second gas pipeline; the source bottle is connected to the inlet of the furnace tube through the first gas pipeline; the spare source bottle is connected to the inlet of the furnace tube through the second gas pipeline.

[0018] In one embodiment, the gas supply system further includes a first valve and a second valve; the first valve is disposed in the first gas pipeline; the second valve is disposed in the second gas pipeline.

[0019] In one embodiment, the gas supply system further includes a check valve; the check valve is disposed in the first gas pipeline.

[0020] In one embodiment, the gas supply system includes at least one source bottle group; the source bottle group includes one spare source bottle and at least two source bottles;

[0021] When any source bottle in the source bottle group meets the liquid shortage condition, the control device controls the source bottles in the source bottle group to stop working and controls the spare source bottle in the source bottle group to enter the working state.

[0022] In a second aspect, the present application provides a diffusion junction formation system for solar cell wafers, characterized by including the gas supply system in any of the above embodiments.

[0023] The above gas supply system and the diffusion junction formation system for solar cells are configured with a source bottle placed in a constant temperature bath; a spare source bottle placed in a spare constant temperature bath; wherein, both the source bottle and the spare source bottle are filled with a source liquid; a gas supply device is configured to introduce gas into the source liquid in the source bottle or the source liquid in the spare source bottle; a liquid level detection device is configured to detect the liquid level of the source liquid in the source bottle to determine liquid level information; wherein, the liquid level detection device is arranged in the constant temperature bath; a control device is configured to control the gas supply device to introduce gas into the source bottle when the liquid level information does not meet the liquid shortage condition, and control the gas supply device to introduce gas into the spare source bottle when the liquid level information meets the liquid shortage condition. Using the above system for gas supply, when the source bottle is short of liquid, the spare source bottle with a set temperature can be used for gas supply, which can ensure the stability of the diffusion junction formation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for the description of the embodiments of the present application or related technologies. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a structural block diagram of a gas supply system in one embodiment;

[0026] Figure 2 It is a structural block diagram of a gas supply system in another embodiment;

[0027] Figure 3 It is a structural block diagram of a gas supply system in yet another embodiment;

[0028] Figure 4 It is a structural block diagram of a single gas supply system in one embodiment;

[0029] Figure 5 It is a structural block diagram of a source bottle group in a gas supply system in one embodiment;

[0030] Figure 6 It is a structural block diagram of multiple constant temperature baths in a gas supply system in one embodiment;

[0031] Figure 7 It is a structural block diagram of multiple furnace tubes in a gas supply system in one embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant accompanying drawings. Embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. can be used herein to describe the relationship of one element or feature shown in the drawings with other elements or features. It should be understood that, in addition to the orientation shown in the drawings, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the drawing is flipped, the element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" the other elements or features. Therefore, the exemplary terms "under" and "below" can include both the upper and lower orientations. In addition, the device may also include additional orientations (such as rotating 90 degrees or other orientations), and the spatial descriptors used herein are accordingly interpreted.

[0035] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In addition, in the following embodiments, "connection", if there is a transfer of electrical signals or data between the connected objects, should be understood as "electrical connection", "communication connection", etc.

[0036] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" or "having" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0037] As described in the background art, diffusion junction formation is an important step in the manufacturing process of solar cell wafers. Generally, in diffusion junction formation, a P-type silicon wafer is placed into a furnace tube, and a gas containing N-type impurity atoms (such as phosphorus atoms) is introduced into the furnace tube. The N-type impurity atoms penetrate and diffuse into the interior of the silicon wafer through the gaps between silicon atoms to form a PN junction; alternatively, P-type impurity atoms (such as boron atoms) are diffused on an N-type silicon wafer to form a PN junction. A protective gas (such as pure nitrogen) is bubbled in a source bottle by a gas supply device (the source bottle contains a source liquid and is placed in a constant temperature bath), and the source liquid vapor is carried into the furnace tube. Phosphorus pentoxide (P2O5) generated by the decomposition of phosphorus oxychloride (POCl3) through high-temperature heating is deposited on the surface of the silicon wafer. Phosphorus pentoxide (P2O5) reacts with silicon to generate silicon dioxide (SiO2) and phosphorus atoms, and diffuses and dopes into the silicon wafer to form a PN junction. Currently, the commonly used source liquid is phosphorus oxychloride, which is respectively used for the diffusion of phosphorus atoms and boron atoms.

[0038] The furnace tube is a device for performing the diffusion process in the manufacturing process of solar cell wafers. For the furnace tube, the interior of the furnace tube is in a low-pressure environment. Source liquids such as phosphorus oxychloride are important doping sources for diffusion. What participates in the reaction in the high-temperature furnace tube is in a gaseous state. Through the method of carrying the source by nitrogen bubbling, it enters the furnace tube and participates in the core reaction as an important raw material. The amount of phosphorus oxychloride needs to be precisely controlled. Currently, the nitrogen flow rate is controlled by a flow meter, and the source bottle temperature is controlled by a constant temperature bath to keep the saturated vapor concentration in the bottle uniform for source amount control. Under different conditions, the source bottle temperature is affected by the reduction of the source amount, or the inaccurate temperature control of the constant temperature bath, resulting in a change in the saturated vapor pressure in the source bottle, thereby affecting the product manufacturing success rate, abnormal isolation rate, and cost per watt.

[0039] After the phosphorus source is used up to a certain amount, the phosphorus source needs to be replaced. During the source replacement period, it will cause the furnace tube to stop, or the constant temperature waiting of the source bottle temperature will cause equipment shutdown and production capacity waste. To solve the above problems and improve the utilization rate of the furnace tube, a gas supply system is provided to solve the problem of furnace tube stoppage caused by the replacement of raw materials due to insufficient phosphorus source materials and improve the utilization rate of the furnace tube.

[0040] For the above reasons, the present application provides a gas supply system. By configuring a source bottle placed in a constant temperature bath and a spare source bottle placed in a spare constant temperature bath, and a liquid level detection device for detecting the liquid level of the source liquid in the source bottle and sending the liquid level information to a control device, wherein the liquid level detection device is arranged in the constant temperature bath, and a control device is further configured to control the source bottle to stop working and control the spare source bottle to enter the working state when the liquid level information meets the liquid shortage condition. It can realize the replacement of the source bottle without stopping the tube during the diffusion junction formation process, improve the utilization rate of the furnace tube, and improve the manufacturing efficiency of solar cell wafers.

[0041] In one embodiment, as Figure 1As shown in the figure, a gas supply system is provided, including: a source bottle 2 placed in a constant temperature bath 1; a spare source bottle 4 placed in a spare constant temperature bath 3; both the source bottle 2 and the spare source bottle 4 are filled with source liquid; a gas supply device 7 for introducing gas into the source liquid in the source bottle 2 or the spare source bottle 4; a liquid level detection device 6 for detecting the liquid level of the source liquid in the source bottle and obtaining liquid level information; the liquid level detection device 6 is arranged in the constant temperature bath 1; a control device 5 for controlling the gas supply device 7 to introduce gas into the source bottle when the liquid level information does not meet the liquid shortage condition; the control device 5 also controls the gas supply device 7 to introduce gas into the spare source bottle 4 when the liquid level information meets the liquid shortage condition.

[0042] Among them, the constant temperature bath 1 is a tank that can provide a constant temperature, and generally maintains a constant temperature by means of resistance wire heating and compressor refrigeration. The source bottle 2 is used for the packaging of solid, liquid and gaseous ultra-pure materials. In this embodiment, the source bottle 2 is used to place the source liquid. The spare constant temperature bath 3 refers to a constant temperature bath prepared for ready use at any time. The spare source bottle 4 is a source bottle prepared for ready use at any time. The control device 5 can be a hardware module including various processing chips and their peripheral circuits and having a logical operation function. The processing chip can be a single-chip microcomputer, a DSP (Digital Signal Process) chip or an FPGA (Field Programmable Gate Array) chip.

[0043] The liquid level detection device 6 refers to a device that can be used to detect the liquid position, such as a liquid level gauge, etc. The gas supply device 7 is a device for supplying gas into the source bottle 2 or the spare source bottle 4. The gas supplied by the gas supply device 7 is generally a protective gas. The gas supply device 7 can include a gas storage unit, a pressure supply unit and a gas transmission unit. The gas transmission unit communicates with the gas storage unit, the source bottle 2 or the spare source bottle 4. The pressure supply unit is arranged on the gas storage unit to provide a constant pressure to the gas storage unit and enable the gas storage unit to provide a constant protective gas to the source bottle 2 or the spare source bottle 4 through the gas transmission unit.

[0044] The liquid level refers to the height position of the liquid. The liquid level information refers to the liquid level information of the liquid level detected by the liquid level detection device 6, which can be used to characterize the remaining capacity of the liquid. The liquid shortage condition refers to the pre-set liquid shortage liquid level information. When the liquid level information meets the liquid shortage condition, it means that the remaining capacity of the source liquid in the source bottle can no longer meet the usage requirements.

[0045] Specifically, in order to maintain the continuous operation of the furnace tube while ensuring gas supply, a source bottle 2 placed in the constant temperature bath 1, a spare source bottle 4 placed in the spare constant temperature bath 3, and a gas supply device 7 for introducing gas into the source liquid in the source bottle 2 or the source liquid in the spare source bottle 4 can be provided. After the gas supply device 7 supplies gas to the source bottle 2 or the spare source bottle 4, bubbling occurs in the source bottle 2 or the spare source bottle 4, and then source liquid vapor is generated. The source liquid vapor can be used for diffusion doping. When the source liquid in the source bottle 2 is sufficient, the source bottle 2 enters the working state; when the source liquid in the source bottle 2 is insufficient, the spare source bottle 4 enters the working state. In this way, the continuity of the gas supply system can be ensured. That is to say, a source bottle 2 placed in the constant temperature bath 1 and a spare source bottle 4 placed in the spare constant temperature bath 3 can be configured. A liquid level detection device 6 is configured to detect the liquid level of the source liquid in the source bottle 2 and send the liquid level information to the control device 5. Among them, the liquid level detection device 6 is arranged in the constant temperature bath 1. When the liquid level information meets the liquid shortage condition, the control device 5 is configured to control the source bottle 2 to stop working and control the spare source bottle 4 to enter the working state.

[0046] In an exemplary embodiment, as Figure 1 shown, the gas supply system further includes a gas supply device 7; the gas supply device is connected to the source bottle 2 and the spare source bottle 4 to form a bubbling device 8. Among them, the bubbling device 8 includes a gas supply device, a source bottle 2 and a spare source bottle 4, and is used for bubbling to generate source liquid vapor.

[0047] The above gas supply system is configured with a spare source bottle placed in the spare constant temperature bath; among them, both the source bottle and the spare source bottle are filled with source liquid; a gas supply device is configured to introduce gas into the source liquid in the source bottle or the source liquid in the spare source bottle; a liquid level detection device is configured to detect the liquid level of the source liquid in the source bottle to determine the liquid level information; among them, the liquid level detection device is arranged in the constant temperature bath; a control device is configured to control the gas supply device to introduce gas into the source bottle when the liquid level information does not meet the liquid shortage condition, and control the gas supply device to introduce gas into the spare source bottle when the liquid level information meets the liquid shortage condition. Using the above system for gas supply, the spare source bottle with a preset temperature can be used for gas supply when the source bottle is short of liquid, which can ensure the stability of the diffusion doping process.

[0048] In an exemplary embodiment, as Figure 2 shown, the constant temperature bath 1 includes a temperature detection device 11 and a heating device 12; the temperature detection device 11 and the heating device 12 are connected to the control device 5.

[0049] Among them, the temperature detection device 11 refers to a device that can detect the temperature of the source liquid in the source bottle 2, such as a temperature sensor, etc. The heating device refers to a device that can heat the source liquid in the source bottle 2, such as an electric heater, etc.

[0050] Specifically, the function of the constant temperature bath 1 is to keep the temperature of the source liquid in the source bottle 2 constant. Therefore, a temperature detection device 11 and a heating device 12 can be set in the constant temperature bath 1. The temperature of the source liquid is detected by the temperature detection device 11. Once the temperature of the source liquid is lower than the temperature threshold, a low-temperature signal can be sent to the control device 5, and the control device 5 controls the heating device 12 to heat the source liquid. When the heating reaches the constant temperature, the heating device 12 can be controlled to stop heating. It can be understood that a temperature detection device and a heating device are also set in the standby constant temperature bath 3.

[0051] In this embodiment, by setting the temperature detection device 11 and the heating device 12 in the constant temperature bath 1, the temperature of the source liquid in the source bottle 2 can be kept constant, thereby ensuring the normal operation of the gas supply system.

[0052] In an exemplary embodiment, as Figure 3 shown, the source bottle 2 is provided with a detection hole 21, and at least a part of the hole wall of the detection hole 21 is in contact with the source liquid; the temperature detection device 11 includes a temperature sensing unit 111; the temperature sensing unit 111 is arranged in the detection hole 21.

[0053] Among them, the detection hole 21 is a hole for detecting temperature, and its form can be a detection groove or an open-shaped hole. The temperature sensing unit 111 can sense the temperature of the source liquid and convert it into an available output signal, such as a thermometer, etc.

[0054] Specifically, in order to detect the temperature of the source liquid, a detection hole 21 can be set in the source bottle 2, and the temperature sensing unit 111 is placed in the detection hole 21. When the detection hole 21 is a detection groove, the temperature sensing unit 111 can be prevented from directly contacting the source liquid, thereby avoiding contaminating the source liquid. Among them, at least a part of the hole wall of the detection hole 21 is in contact with the source liquid, which can ensure that the temperature sensing unit 111 can detect the source liquid.

[0055] In this embodiment, by setting the detection hole 21 in the source bottle 2 and placing the temperature sensing unit 111 in the detection hole 21, the contamination caused by the temperature sensing unit 111 directly contacting the source liquid can be avoided.

[0056] In an exemplary embodiment, as Figure 3 shown, the liquid level detection device 6 includes at least two liquid level detection units 61.

[0057] Among them, the liquid level detection unit 61 is used to detect the liquid position of the source liquid. The liquid level detection unit 61 can be a continuous float level transmitter, which uses a float that moves with the liquid level to provide continuous liquid level measurement; it can also be a differential pressure transmitter, which measures the pressure difference between two points in the fluid and correlates it with the liquid level; it can also be a load cell, which uses force measurement to infer the liquid level; or a radar level gauge, which uses radio wave technology to determine the distance between the fluid and the sensor, thereby determining the liquid level; or a radio frequency capacitance level gauge, which measures using the capacitance change caused by the liquid level change; or an ultrasonic level gauge, which sends ultrasonic pulses to the fluid surface and calculates the liquid level based on the time required for the pulses to return.

[0058] Specifically, in order to measure the source liquid level more accurately, at least two liquid level detection units 61 can be set up in the constant temperature bath 1 along the height direction of the source liquid. In the case where one liquid level detection unit 61 is damaged, the liquid level can be detected by the remaining liquid level detection units 61 to ensure the normal progress of the liquid level detection work. Further, the position of the liquid level detection unit 61 is located between the outer wall of the constant temperature bath and the source bottle, and is arranged along the height direction on the outer wall of the source bottle.

[0059] In this embodiment, by setting at least two liquid level detection units 61, the source liquid level can be measured more accurately.

[0060] In an exemplary embodiment, as Figure 3 shown, each liquid level detection unit 61 is arranged along the height direction.

[0061] Specifically, two liquid level detection units 61 can be set up in the constant temperature bath 1 along the height direction of the source liquid. Setting up the liquid level detection units 61 at different heights can facilitate the detection of different liquid level positions.

[0062] In a specific embodiment, one of the liquid level detection units 61 is located at the lowermost end of the outer side wall of the source bottle 2, and the other liquid level detection unit 61 is located on the outer side wall of the source bottle 2, and its position can be determined by the liquid level information corresponding to the liquid shortage condition.

[0063] In an exemplary embodiment, as Figure 4 shown, the gas supply system further includes a first gas pipeline 10 and a second gas pipeline 11; the source bottle 2 is connected to the gas inlet 91 of the furnace tube 9 through the first gas pipeline 10; the spare source bottle 4 is connected to the gas inlet 91 of the furnace tube 9 through the second gas pipeline 11.

[0064] Among them, the first gas pipeline 10 is used to transport the source liquid vapor generated in the source bottle 2. The second gas pipeline 11 is used to transport the source liquid vapor generated in the spare source bottle 4. The furnace tube 9 is a device for performing the diffusion process, and the process of manufacturing the PN junction in the diffusion and junction formation process is carried out in the furnace tube 9. The gas inlet 91 of the furnace tube 9 is used to receive the source liquid vapor.

[0065] Specifically, after the source liquid vapor is generated in the source bottle 2, the source liquid vapor can be transported into the air inlet 91 of the furnace tube 9 through the first gas pipeline 10; after the source liquid vapor is generated in the standby source bottle 4, the source liquid vapor can be transported into the air inlet 91 of the furnace tube 9 through the second gas pipeline 11. After the furnace tube 9 receives sufficient source liquid vapor, the PN junction can be fabricated.

[0066] In this embodiment, by connecting the source bottle 2 and the standby source bottle 4 through two gas pipelines respectively, the path of the source liquid vapor transportation can be effectively controlled according to the actual situation, improving the efficiency of gas supply.

[0067] In an exemplary embodiment, as Figure 4 shown, the gas supply system further includes a first valve 12 and a second valve 13; the first valve 12 is arranged on the first gas pipeline 10; the second valve 13 is arranged on the second gas pipeline 11.

[0068] Among them, the first valve 12 is used to control the gas flow in the first gas pipeline 10, and the second valve 13 is used to control the gas flow in the second gas pipeline 11. In this embodiment, both the first valve 12 and the second valve 13 are pneumatic valves. Among them, a pneumatic valve is a valve that uses compressed air to push multiple sets of combined pneumatic pistons inside the actuator to move.

[0069] Specifically, in order to avoid the interference of gas flow between the source bottle 2 and the standby source bottle 4, a first valve 12 can be arranged for the first gas pipeline 10, and a second valve 13 can be arranged for the second gas pipeline 11. When the source bottle 2 is working, the first valve 12 is opened and the second valve 13 is closed. When the standby source bottle 4 is working, the first valve 12 is closed and the second valve 13 is opened.

[0070] In this embodiment, by arranging a first valve 12 for the first gas pipeline 10 and a second valve 13 for the second gas pipeline 11, the interference of gas flow between the source bottle 2 and the standby source bottle 4 can be avoided, reducing the influence on the working state of the gas supply system.

[0071] In an exemplary embodiment, as Figure 4 shown, the gas supply system further includes a check valve 14; the check valve 14 is arranged on the first gas pipeline 10.

[0072] Among them, the check valve 14 is a valve used to prevent the backflow of gas or liquid.

[0073] Specifically, in order to prevent the backflow of the source liquid vapor or the source liquid, a check valve 14 can be arranged on the first gas pipeline. It can be understood that the same check valve can also be arranged on the second gas pipeline.

[0074] In an exemplary embodiment, as Figure 5As shown in the figure, the gas supply system includes at least one source bottle group 15; the source bottle group 15 includes a spare source bottle 4 and at least two source bottles; when any source bottle in the source bottle group 15 meets the liquid shortage condition, the control device 5 controls the source bottles in the source bottle group 15 to stop working and controls the spare source bottle 4 in the source bottle group 15 to enter the working state.

[0075] Among them, the source bottle group 15 refers to a source bottle combination including multiple source bottles and a spare source bottle 4.

[0076] Specifically, the gas supply system may include multiple source bottle groups 15. For each source bottle group 15, when the source liquid in any source bottle 2 in the group is in a liquid shortage state, it is necessary to control the source bottle to stop working and control the spare source bottle 4 to enter the working state. Adopting this one-to-many combination mode can reduce costs.

[0077] In a specific embodiment, Figure 5 As shown in the figure, there is a source bottle group, which includes a spare source bottle 4, source bottles 211, 212, 213, 214, and 215.

[0078] In an exemplary embodiment, a solar cell diffusion junction formation system is provided, which is characterized by including the gas supply system in any of the above embodiments.

[0079] Among them, the solar cell diffusion junction formation system is for performing diffusion junction formation during the production process of solar cells.

[0080] Specifically, since a solar cell requires a relatively large PN junction to convert solar energy into electrical energy, the above gas supply system can be set up in the solar cell diffusion junction formation system, and source liquid vapor supply and PN junction formation are carried out through the above gas supply system, so as to realize solar cell diffusion junction formation.

[0081] In an exemplary embodiment, a solar cell diffusion junction formation system is further provided, which can solve the problems of phosphorus source replacement and abnormal temperature control of the constant temperature bath resulting in tube stoppage, ensure that the manufacturing of solar cells meets the production capacity requirements, and reduce the manufacturing cost of solar cells and control the operation risk. Among them, the phosphorus source is contained in the source liquid.

[0082] This embodiment provides a gas supply system for solving the problem of phosphorus source supply in the furnace tube, including a constant temperature bath, and the constant temperature bath has the functions of detecting the phosphorus source liquid level and temperature; as Figure 6 shown in the figure, the constant temperature bath may include: constant temperature baths 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, all of which are connected to the control device 5;

[0083] Valve, used to control the gas in the phosphorus source pipeline to select the furnace tube;

[0084] Standby constant temperature bath, used for phosphorus source switching;

[0085] Furnace tube 9, used to provide a reaction chamber, including 5 furnace tubes or not limited to 5 furnace tubes, respectively defining furnace tube 911, furnace tube 912, furnace tube 913, furnace tube 914, furnace tube 915, etc. The layout structure schematic diagram is as Figure 7 shown; among them, as Figure 5 shown, furnace tube 911 corresponds to the air inlet 9111, furnace tube 912 corresponds to the air inlet 9112, furnace tube 913 corresponds to the air inlet 9113, furnace tube 914 corresponds to the air inlet 9114, and furnace tube 915 corresponds to the air inlet 9115.

[0086] Source bottle, used to hold the source liquid. 5 furnace tubes correspond to 5 source bottles, plus one standby source bottle;

[0087] Among them, as Figure 5 shown, the valve is used to control the opening and closing of the gas path; including the first valve 121, the first valve 122, the first valve 123, the first valve 124, the first valve 125, the second valve 131, the second valve 132, the second valve 1233, the second valve 134, the second valve 135. Each pipe gas path is equipped with a one-way valve, including the one-way valve 141, the one-way valve 142, the one-way valve 143, the one-way valve 144, the one-way valve 145, which is a device to prevent the backflow of gas or liquid. The overall connection method of each pipe is carried out according to Figure 5 the method, and the single-pipe gas path connection method is carried out according to Figure 4 for pipeline and valve body connection.

[0088] Common pipelines and several connecting pipelines.

[0089] The implementation principle of this embodiment is: the control device collects the liquid level information of each constant temperature bath, identifies the liquid level of the source liquid in the constant temperature bath. The liquid level is collected by 2 liquid level detection units. When the phosphorus source quantity meets the process requirements, the gas paths of each pipe corresponding to the constant temperature bath corresponding to each pipe are controlled respectively. When the phosphorus source in one pipe is insufficient, during the source replacement or waiting for source replacement, the control device switches the pipeline valve of the current source path to shield the current pipeline, switches to the standby pipeline, and uses the standby source bottle for the process. The process of the current furnace tube operates normally without abnormal shutdown, which can effectively improve the utilization rate of the furnace tube, reduce the waste of furnace tube shutdown, thereby improving the production capacity output and effectively improving the utilization rate of the machine.

[0090] The specific method is as follows: Generally, for the furnace tube 911, under normal circumstances, the first valve 121 is normally opened or closed, the second valve 131 remains normally closed, and the gas path normally inputs from the source bottle 211 into the furnace tube 911 to participate in the process. When the source bottle 211 is abnormal, the first valve 121 and the second valve 131 are closed to allow the gas to enter the furnace tube 911 to participate in the reaction. Other furnace tubes are controlled in the same principle.

[0091] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0092] The above-described embodiments merely represent several implementation manners of this application, and the description is relatively specific and detailed. However, it should not be construed as a limitation to the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several deformations and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. A gas supply system, characterized in that, Comprising: A source bottle placed in a constant temperature bath; A spare source bottle placed in a spare constant temperature bath; both the source bottle and the spare source bottle are filled with source liquid; A gas supply device for introducing gas into the source liquid in the source bottle or the source liquid in the spare source bottle; A liquid level detection device for detecting the liquid level of the source liquid in the source bottle to obtain liquid level information; the liquid level detection device is arranged in the constant temperature bath; A control device for controlling the gas supply device to introduce gas into the source bottle when the liquid level information does not meet the liquid shortage condition; the control device also controls the gas supply device to introduce gas into the spare source bottle when the liquid level information meets the liquid shortage condition.

2. The gas supply system according to claim 1, characterized in that, The constant temperature bath includes a temperature detection device and a heating device; the temperature detection device and the heating device are connected to the control device.

3. The gas supply system according to claim 2, characterized in that, The source bottle is provided with a detection hole, and at least a part of the hole wall of the detection hole is in contact with the source liquid; the temperature detection device includes a temperature sensing unit; the temperature sensing unit is arranged in the detection hole.

4. The gas supply system according to claim 1, characterized in that, The liquid level detection device includes at least two liquid level detection units; each of the liquid level detection units is respectively connected to the control device.

5. The gas supply system according to claim 4, characterized in that, Each of the liquid level detection units is arranged along the height direction.

6. The gas supply system according to claim 5, wherein The gas supply system further includes a first gas pipeline and a second gas pipeline; The source bottle is connected to the inlet of the furnace tube through the first gas pipeline; the spare source bottle is connected to the inlet of the furnace tube through the second gas pipeline.

7. The gas supply system according to claim 6, wherein, The gas supply system further includes a first valve and a second valve; the first valve is arranged in the first gas pipeline; the second valve is arranged in the second gas pipeline.

8. The gas supply system according to claim 6, characterized in that, The gas supply system further includes a check valve; the check valve is arranged in the first gas pipeline.

9. The gas supply system according to any one of claims 1 to 8, characterized in that, The gas supply system includes at least one source bottle group; the source bottle group includes one spare source bottle and at least two source bottles; The control device controls the source bottles in the source bottle group to stop working and controls the spare source bottle in the source bottle group to enter the working state when any source bottle in the source bottle group meets the liquid shortage condition.

10. A diffusion junction formation system for solar cell wafers, characterized in that, Comprising the gas supply system according to any one of claims 1 to 9.

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