Solar cell silicon wafer diffusion furnace

Abstract

The application discloses a solar cell silicon wafer diffusion furnace, and relates to the technical field of photovoltaic cells, which comprises a furnace body, a hearth arranged in the furnace body, and a phosphorus source supply pipe arranged at the tail end of the hearth; further comprising: an inner drive ring body; the inner drive ring body comprises an outer ring seat and an inner rotating ring; the outer ring seat is sleeved on the inner wall of the hearth and is clamped with the inner wall of the hearth; the inner rotating ring is coaxially arranged with the outer ring seat and is rotationally connected with the outer ring seat; the inner circle of the inner rotating ring is provided with a fan ring; a plurality of driving air holes corresponding to the fan ring are formed in the outer ring seat in the circumferential direction; the outer ring seat is provided with an air inlet; and the air inlet is in communication with the plurality of driving air holes. The rotating cooperation structure formed by the outer ring seat and the inner rotating ring can drive the fan ring to rotate when air is introduced into the driving air holes, and then drives the airflow to move; compared with the conventional flow guide structure, the application has a better airflow driving effect, can improve the diffusion uniformity and stability of the process gas in the hearth, and improves the diffusion effect of the photovoltaic silicon wafer.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic cell technology, and more specifically to a silicon wafer diffusion furnace for solar cells. Background Technology

[0002] In the production of solar cells, phosphorus and boron are typically diffused into silicon wafers to form the PN junction in the solar cell. A diffusion furnace is the equipment used in this production step. Its main principle is to place the silicon wafer into a furnace tube and introduce process gas from the end of the tube, causing a chemical reaction at high temperature that ultimately diffuses phosphorus and boron into the silicon wafer. However, existing diffusion furnace tubes consistently suffer from the following problems:

[0003] Since the process gas enters the furnace tube from the tail end and exits from the exhaust port at the mouth end, the process gas at the tail end of the furnace tube has a high content of gases that need to participate in the reaction. Therefore, the diffusion effect of phosphorus and boron elements in the silicon wafers at the tail end of the furnace tube is good. As the process gas moves and reacts in the furnace tube, the content of gases that need to participate in the reaction decreases towards the furnace tube mouth. Furthermore, during the diffusion reaction, it is necessary to ensure not only the diffusion uniformity of silicon wafers throughout the furnace tube, but also the element diffusion uniformity of individual silicon wafers.

[0004] To address this technical problem, existing patents include utility model patents such as application number 201720902507.5, entitled "A Uniform Diffusion Quartz Diffusion Furnace for Photovoltaic Silicon Wafers," and invention patent applications such as application number 202010031578.9, entitled "A Diffusion Furnace for Photovoltaic Cell Production." Both disclose achieving uniform diffusion of process gases through a guiding effect. However, to further improve the uniformity of diffusion while simultaneously balancing the simplicity and reliability of the installation structure, continuous structural improvements and upgrades are still needed to achieve better diffusion results.

[0005] Therefore, how to provide a diffusion furnace that is more conducive to improving the diffusion uniformity in photovoltaic production is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a solar cell silicon wafer diffusion furnace, which aims to solve the above-mentioned technical problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A solar cell silicon wafer diffusion furnace includes a furnace body and a furnace chamber disposed within the furnace body, wherein a phosphorus source supply pipe is installed at the tail end of the furnace chamber; and further includes an inner driving ring.

[0009] The inner drive ring body includes an outer ring seat and an inner rotating ring; the outer ring seat is sleeved on the inner wall of the furnace and is clamped to the inner wall of the furnace; the inner rotating ring is coaxially arranged with the outer ring seat and rotatably connected to the outer ring seat; the inner ring of the inner rotating ring has a fan blade ring; the outer ring seat has a plurality of drive air holes corresponding to the fan blade ring in the circumferential direction; the outer ring seat has an air inlet interface; the air inlet interface is connected to the plurality of drive air holes.

[0010] Through the above technical solution, the solar cell silicon wafer diffusion furnace provided by the present invention installs the inner driving ring inside the furnace chamber. Utilizing the rotational mating structure formed by the outer ring seat and the inner rotating ring, the fan blade ring can be driven to rotate when air enters through the driving vents, thereby driving the airflow. Compared with conventional flow guiding structures, the present invention has a better airflow driving effect, which can improve the diffusion uniformity and stability of process gas in the furnace chamber, improve the diffusion effect of photovoltaic silicon wafers, and has a simple structure, is easy to install, and is convenient for widespread use.

[0011] Preferably, in the above-mentioned solar cell silicon wafer diffusion furnace, multiple support plates are circumferentially engaged within the strip grooves of the furnace inner wall. Each support plate includes a plug inserted into the strip groove and an arc-shaped support plate. The outer wall of the outer ring seat is pressed against the inner side of the multiple arc-shaped support plates. This invention utilizes the existing structure within the furnace chamber, using support plates to stably mount the inner drive ring body onto the furnace inner wall, resulting in a simple, stable, and reliable structure.

[0012] Preferably, in the above-mentioned solar cell silicon wafer diffusion furnace, the outer ring seat includes a fixed ring and a movable ring; the outer side wall of the fixed ring is pressed against the inner side of the plurality of arc-shaped support plates, the movable ring is fixedly connected to the fixed ring and forms an annular gap, and the inner rotating ring is rotatably connected within the annular gap. The outer ring seat adopts a detachable split form, which allows the inner driving ring body to be easily and conveniently installed within the annular gap.

[0013] Preferably, in the above-described solar cell silicon wafer diffusion furnace, the fixed ring includes a support ring, which is pressed against the inner side of the plurality of arc-shaped support plates. One annular edge of the support ring has a first annular protrusion protruding radially inward. The movable ring includes a connecting ring coaxially sleeved inside the support ring. One annular edge of the connecting ring has a second annular protrusion protruding radially inward, the second annular protrusion corresponding to the first annular protrusion and spaced apart to form the annular gap. The support ring and the connecting ring enable a stable connection between the fixed ring and the movable ring.

[0014] Preferably, in the aforementioned solar cell silicon wafer diffusion furnace, multiple ball bearings are embedded on the opposing annular end faces of both the first and second annular protrusions. The ball bearings ensure more stable and smooth rotation of the inner rotating ring.

[0015] Preferably, in the above-mentioned solar cell silicon wafer diffusion furnace, the inner rotating ring includes a rotating base ring, which is sandwiched between the first annular protrusion and the second annular protrusion, and both end faces have arc-shaped recesses that cooperate with the ball bearings; a plurality of inclined fan blades are fixed along the inner edge of the rotating base ring, and an inner support ring is fixed to the inner side of the plurality of fan blades. The inner rotating ring has a simple structure and is easy to connect.

[0016] Preferably, in the above-mentioned solar cell silicon wafer diffusion furnace, the inclined arrangement of the fan blades ensures that air is drawn from the rear to the front of the furnace chamber. This airflow direction satisfies the diffusion requirements of the process gases.

[0017] Preferably, in the above-mentioned solar cell silicon wafer diffusion furnace, the connecting ring and the supporting ring are fastened together by a first bolt, and the supporting ring has a radially outwardly protruding limiting ring on its edge away from the first annular convex edge. The limiting ring and the arc-shaped support plate are fastened together by a second bolt. Using a bolted connection improves the stability of the connection, and the connection is simple and the structure reliable.

[0018] Preferably, in the aforementioned solar cell silicon wafer diffusion furnace, the driving air holes are formed on the inner ring of the first annular convex edge, and the plurality of driving air holes are interconnected. The air inlet is connected to the outer end face of the first annular convex edge and communicates with the plurality of driving air holes. The plurality of driving air holes can blow air under the unified control of the air inlet.

[0019] Preferably, in the above-mentioned solar cell silicon wafer diffusion furnace, the number of the inner driving rings is multiple. The number can be adaptively selected according to the usage requirements.

[0020] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a solar cell silicon wafer diffusion furnace, which has the following beneficial effects:

[0021] 1. The diffusion furnace provided by the present invention has an inner driving ring installed inside the furnace chamber. By utilizing the rotational mating structure formed by the outer ring seat and the inner rotating ring, the fan blade ring can be driven to rotate when the gas is introduced through the driving vent, thereby driving the airflow. Compared with conventional flow guiding structures, the present invention has a better airflow driving effect, which can improve the diffusion uniformity and stability of process gas in the furnace chamber and improve the diffusion effect of photovoltaic silicon wafers.

[0022] 2. The present invention adopts a split structure of support plate, fixed ring, movable ring and inner rotating ring, which is easy to disassemble and assemble, and the structure is simple and easy to promote and use. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 The attached figure is a schematic diagram of the furnace structure in the prior art;

[0025] Figure 2 The attached figure is a schematic diagram of the internal drive ring body provided by the present invention;

[0026] Figure 3 The attached figure is a schematic diagram of the structure of the support sheet provided by the present invention;

[0027] Figure 4 The attached figure is a schematic diagram of the structure of the fixing ring of the outer ring seat provided by the present invention;

[0028] Figure 5 The attached figure shows the invention provided with... Figure 4 A schematic diagram of the structure of the fixing ring of the outer ring seat facing opposite directions;

[0029] Figure 6 The attached figure is a schematic diagram of the structure of the movable ring of the outer ring seat provided by the present invention;

[0030] Figure 7 The attached figure shows the invention provided with... Figure 6 A schematic diagram of the structure of the movable ring of the outer ring seat in opposite directions;

[0031] Figure 8 The attached figure is a schematic diagram of the inner rotating ring provided by the present invention;

[0032] Figure 9 The attached figure is a cross-sectional view of the inner drive ring body provided by the present invention;

[0033] Figure 10 The attached figure is provided by the present invention. Figure 9 A magnified view of part A in the middle;

[0034] Figure 11 The attached figure is a schematic diagram of the structure of the inner drive ring body installed inside the furnace according to Embodiment 1 of the present invention;

[0035] Figure 12 The attached figure is a schematic diagram of the structure of the inner drive ring body installed inside the furnace according to Embodiment 2 of the present invention;

[0036] Figure 13 The attached figure is a schematic diagram of the internal drive ring body installed inside the furnace in Embodiment 3 of the present invention.

[0037] in:

[0038] 1-Furnace chamber;

[0039] 11-Strip groove;

[0040] 2-Phosphorus source supply pipe;

[0041] 3-Internal driving ring;

[0042] 31-Outer ring seat; 311-Fixing ring; 3111-Support ring; 3112-First annular convex edge; 3113-Limiting ring; 3114-Drive air hole; 3115-Air inlet; 312-Moving ring; 3121-Connecting ring; 3122-Second annular convex edge; 313-First bolt; 314-Second bolt; 315-Ball bearing; 32-Inner rotating ring; 321-Fan blade ring; 3211-Fan blade; 3212-Inner support ring; 322-Rotating base ring; 3221-Arc-shaped recess; 33-Support plate; 331-Plug; 332-Arc-shaped support plate. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] See appendix Figure 1 To be continued Figure 2 and attached Figure 9 To be continued Figure 11 The present invention discloses a solar cell silicon wafer diffusion furnace, including a furnace body and a furnace chamber 1 disposed in the furnace body, wherein a phosphorus source supply pipe 2 is installed at the tail end of the furnace chamber 1; and further includes: an inner driving ring body 3.

[0045] The inner drive ring 3 includes an outer ring seat 31 and an inner rotating ring 32; the outer ring seat 31 is fitted onto the inner wall of the furnace 1 and is clamped to the inner wall of the furnace 1; the inner rotating ring 32 is coaxially arranged with the outer ring seat 31 and is rotatably connected to the outer ring seat 31; the inner ring of the inner rotating ring 32 has a fan blade ring 321; the outer ring seat 31 has multiple drive air holes 3114 corresponding to the fan blade ring 321 in the circumferential direction; the outer ring seat 31 has an air inlet 3115; the air inlet 3115 is connected to the multiple drive air holes 3114.

[0046] See appendix Figure 3Multiple support plates 33 are circumferentially fitted into the strip groove 11 on the inner wall of the furnace 1. Each support plate 33 includes a plug 331 inserted into the strip groove 11 and an arc-shaped support plate 332. The outer wall of the outer ring seat 31 is pressed against the inner side of the multiple arc-shaped support plates 332.

[0047] See appendix Figure 4 To be continued Figure 7 The outer ring seat 31 includes a fixed ring 311 and a movable ring 312; the outer side wall of the fixed ring 311 is pressed against the inner side of multiple arc-shaped support plates 332, the movable ring 312 is fixedly connected to the fixed ring 311 and forms an annular gap, and the inner rotating ring 32 is rotatably connected within the annular gap.

[0048] To further optimize the above technical solution, the fixed ring 311 includes a support ring 3111, which is pressed against the inner side of multiple arc-shaped support plates 332. One annular edge of the support ring 3111 has a first annular protrusion 3112 that protrudes radially inward. The movable ring 312 includes a connecting ring 3121 coaxially sleeved inside the support ring 3111. One annular edge of the connecting ring 3121 has a second annular protrusion 3122 that protrudes radially inward. The second annular protrusion 3122 corresponds to the first annular protrusion 3112 and forms an annular gap between them.

[0049] To further optimize the above technical solution, multiple balls 315 are embedded on the opposite annular end faces of the first annular protrusion 3112 and the second annular protrusion 3122.

[0050] See appendix Figure 8 The inner rotating ring 32 includes a rotating base ring 322, which is sandwiched between a first annular protrusion 3112 and a second annular protrusion 3122, and both end faces are formed with arc-shaped recesses 3221 that cooperate with the ball 315; a plurality of inclined fan blades 3211 are fixed along the inner edge of the rotating base ring 322, and an inner support ring 3212 is fixed on the inner side of the plurality of fan blades 3211.

[0051] To further optimize the above technical solution, the inclined arrangement direction of the fan blades 3211 satisfies the requirement of drawing air from the tail to the head of the furnace 1.

[0052] See appendix Figure 9 and attached Figure 10 The connecting ring 3121 and the support ring 3111 are fastened together by the first bolt 313. The edge of the support ring 3111 away from the first annular protrusion 3112 has a radially outward protruding limiting ring 3113. The limiting ring 3113 and the arc-shaped support plate 332 are fastened together by the second bolt 314.

[0053] See appendix Figure 10The driving air hole 3114 is opened in the inner ring of the first annular protrusion 3112, and the multiple driving air holes 3114 are interconnected. The air inlet 3115 is connected to the outer end face of the first annular protrusion 3112 and is connected to the multiple driving air holes 3114.

[0054] The installation method of the inner drive ring 3 provided by the present invention is as follows:

[0055] First, multiple support plates 33 are evenly distributed around the perimeter and inserted into the strip groove 11 of the furnace body 1. The plug 331 is inserted into the strip groove 11, and the arc-shaped support plate 332 is exposed and fits against the inner wall of the furnace body 1. In this embodiment, the number of support plates 33 can be selected as four.

[0056] Then, the fixing ring 311 is assembled so that the support ring 3111 of the fixing ring 311 is pressed against the inner side of the multiple arc-shaped support plates 332. Then, the limiting ring 3113 is tightened and fixed to the arc-shaped support plate 332 by the second bolt 314.

[0057] Install the inner rotating ring 32 so that the arc-shaped recess 3221 on one side of the rotating base ring 322 engages with the ball 315 on the first annular protrusion 3112. Then install the movable ring 312 so that the ball 315 on the second annular protrusion 3122 of the movable ring 312 engages with the arc-shaped recess 3221 on the other side of the rotating base ring 322. Then tighten and fix the connecting ring 3121 and the support ring 3111 with the first bolt 313.

[0058] Connect the ventilation pipe to the air inlet 3115. When air enters through the ventilation pipe, it drives the air hole 3114 to release air, which blows towards the fan blade 3211, causing the rotating base ring 322 to rotate within the annular gap. This then drives the airflow. Since the inclined arrangement of the fan blade 3211 satisfies the requirement of drawing air from the tail to the head of the furnace 1, it can achieve uniform diffusion of the process gas.

[0059] The diffusion furnace provided by the present invention has an inner driving ring 3 installed inside the furnace chamber 1. Utilizing the rotational mating structure formed by the outer ring seat 31 and the inner rotating ring 32, the fan blade ring 321 can be driven to rotate when air is introduced through the driving air hole 3114, thereby driving the airflow. Compared with conventional flow guiding structures, the present invention has a better airflow driving effect, which can improve the diffusion uniformity and stability of process gas in the furnace chamber 1 and improve the diffusion effect of photovoltaic silicon wafers.

[0060] Example 1:

[0061] See appendix Figure 11 In this embodiment, there is one inner drive ring 3, which is installed in the middle of the furnace 1. The arrows in the figure indicate the direction of process gas inlet flow.

[0062] The installation method in this embodiment is the same as described above, and will not be repeated here.

[0063] Example 2:

[0064] See appendix Figure 12 In this embodiment, there are two internal drive rings 3, which are installed at both ends of the furnace 1. The arrows in the figure indicate the direction of process gas inlet flow.

[0065] The installation method in this embodiment is the same as described above, and will not be repeated here.

[0066] It should be noted that after the two inner drive rings 3 are installed, the air intake ports 3115 face outwards to facilitate the connection of the ventilation pipes.

[0067] Example 3:

[0068] See appendix Figure 13 In this embodiment, there are three internal drive rings 3, which are installed at both ends and the middle of the furnace 1. The arrows in the figure indicate the direction of process gas inlet flow.

[0069] The installation method in this embodiment is the same as described above, and will not be repeated here.

[0070] It should be noted that, among the three inner drive rings 3, the two inner drive rings 3 located at both ends have their air intake ports 3115 facing outwards after installation, which facilitates the connection of the ventilation pipes. The air intake port 3115 of the inner drive ring 3 located in the middle can be set in any direction.

[0071] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A solar cell silicon wafer diffusion furnace, comprising a furnace body and a furnace chamber (1) disposed within the furnace body, wherein a phosphorus source supply pipe (2) is installed at the tail end of the furnace chamber (1); characterized in that, Also includes: Internal drive annular body (3); The inner drive ring (3) includes an outer ring seat (31) and an inner rotating ring (32); the outer ring seat (31) is sleeved on the inner wall of the furnace (1) and is clamped to the inner wall of the furnace (1); the inner rotating ring (32) is coaxially arranged with the outer ring seat (31) and is rotatably connected to the outer ring seat (31); the inner ring of the inner rotating ring (32) has a fan blade ring (321); the outer ring seat (31) has a plurality of drive air holes (3114) corresponding to the fan blade ring (321) in the circumferential direction; the outer ring seat (31) has an air inlet (3115); the air inlet (3115) is connected to the plurality of drive air holes (3114); Multiple support plates (33) are circumferentially fitted in the strip groove (11) of the inner wall of the furnace (1). The support plate (33) includes a plug (331) inserted into the strip groove (11) and an arc-shaped support plate (332). The outer wall of the outer ring seat (31) is pressed against the inner side of the multiple arc-shaped support plates (332). The outer ring seat (31) includes a fixed ring (311) and a movable ring (312); the outer side wall of the fixed ring (311) is pressed against the inner side of the plurality of arc-shaped support plates (332); the movable ring (312) is fixedly connected to the fixed ring (311) and forms an annular gap; the inner rotating ring (32) is rotatably connected within the annular gap. The fixed ring (311) includes a support ring (3111), which is pressed against the inner side of the plurality of arc-shaped support plates (332). One annular edge of the support ring (3111) has a first annular protrusion (3112) that protrudes radially inward. The movable ring (312) includes a connecting ring (3121) that is coaxially sleeved inside the support ring (3111). One annular edge of the connecting ring (3121) has a second annular protrusion (3122) that protrudes radially inward. The second annular protrusion (3122) corresponds to the first annular protrusion (3112) and forms the annular gap between them. Multiple balls (315) are embedded on the opposite annular end faces of the first annular protrusion (3112) and the second annular protrusion (3122). The inner rotating ring (32) includes a rotating base ring (322), which is sandwiched between the first annular protrusion (3112) and the second annular protrusion (3122), and both end faces are formed with arc-shaped recesses (3221) that cooperate with the ball (315); a plurality of inclined fan blades (3211) are fixed on the inner edge of the rotating base ring (322), and an inner support ring (3212) is fixed on the inner side of the plurality of fan blades (3211).

2. The solar cell silicon wafer diffusion furnace according to claim 1, characterized in that, The inclined arrangement of the fan blades (3211) satisfies the requirement of drawing air from the tail to the head of the furnace (1).

3. The solar cell silicon wafer diffusion furnace according to claim 1, characterized in that, The connecting ring (3121) and the support ring (3111) are fastened together by a first bolt (313). The support ring (3111) has a radially outward protruding limiting ring (3113) on its edge away from the first annular protrusion (3112). The limiting ring (3113) and the arc-shaped support plate (332) are fastened together by a second bolt (314).

4. The solar cell silicon wafer diffusion furnace according to claim 1, characterized in that, The driving air hole (3114) is opened on the inner ring of the first annular convex edge (3112), and the multiple driving air holes (3114) are interconnected. The air inlet (3115) is connected to the outer end face of the first annular convex edge (3112) and is connected to the multiple driving air holes (3114).

5. A solar cell silicon wafer diffusion furnace according to any one of claims 1-4, characterized in that, The number of the internal driving rings (3) is multiple.

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