Slow lifting device and alkali polishing equipment of solar cell

Abstract

The invention discloses a slow lifting device and alkali polishing equipment of a solar cell, and relates to the field of photovoltaic equipment. A slow lifting device comprises a lifting groove, a lifting frame, a flower basket, a driving mechanism and an air knife mechanism. The flower basket is arranged on the lifting frame and is used for bearing a silicon wafer; the lifting frame is arranged in the lifting groove, and the driving mechanism is connected with the lifting frame and used for driving the lifting frame to ascend and descend in the lifting groove; an air outlet of the air knife mechanism is formed in an area close to a groove opening of the lifting groove and is used for blowing gas to the flower basket lifted out of the lifting groove so as to blow off liquid drops attached to the flower basket. According to the invention, the problem of poor watermark of the Topcon battery on the EL / PL caused by the residual liquid drop of the flower basket can be solved.

Description

Technical Field

[0001] The present application belongs to the technical field of photovoltaic equipment, and specifically relates to a slow pulling device and an alkali polishing device for solar cells. Background Art

[0002] At present, in the process preparation of Topcon alkaline polishing, the BSG on the P+ surface needs to be retained as the P+ surface bypass plating problem caused by the deposition of the tunneling oxide layer and poly on the N+ surface. Therefore, the acid tank concentration of the alkaline polishing is relatively low, which leads to the P+ surface always showing hydrophilicity due to the retention of BSG during the slow pulling and dehydration of the alkaline polishing. When the silicon wafer and the flower basket are lifted upward in the slow pulling tank, there will be residual droplets between the flower basket teeth. During the drying process in the drying tank, they gradually slide down to form a natural oxide layer of a certain thickness. In the LPCVD process, due to the formation of the tunneling oxide layer, the natural oxide layer formed by the droplet sliding is superimposed on the oxide layer formed during the process. The local oxide layer is thicker than the area without droplet sliding. After the finished battery is printed, an obvious watermark problem will be shown on the EL / PL. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a slow pulling device and an alkaline polishing device for solar cells, which can solve the problem of poor watermarks on the EL / PL of Topcon cells caused by residual droplets in the flower basket.

[0004] In order to solve the above technical problems, this application is implemented as follows: The embodiment of the present application provides a slow pulling device, including: a pulling trough, a pulling frame, a flower basket, a driving mechanism and an air knife mechanism; The flower basket is arranged on the lifting frame and is used to carry silicon wafers; The lifting frame is arranged on the lifting groove, and the driving mechanism is connected to the lifting frame and is used to drive the lifting frame to move up and down in the lifting groove; The air outlet of the wind knife mechanism is arranged in a region close to the notch of the pulling groove, and is used to blow gas toward the flower basket pulled out of the pulling groove to blow off the droplets attached to the flower basket.

[0005] An embodiment of the present application also provides an alkali polishing device for solar cells, comprising the above-mentioned slow pulling device.

[0006] The slow pulling device in the embodiment of the present application can, by adding a wind knife mechanism, blow gas toward the flower basket carried by the lifting frame when the driving mechanism lifts the lifting frame and the flower basket it carries from the pulling groove, so that droplets attached to the flower basket can be blown off by the gas, effectively alleviating the problem of obvious watermarks on the EL / PL of the battery caused by residual droplets on the flower basket. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a schematic diagram of the slow pulling device disclosed in the embodiment of the present application.

[0008] Description of reference numerals: 10-lifting groove; 11-notch; 20-lifting rack; 30-flower basket; 40-driving mechanism; 41-base frame; 42-lifting claw; 50-air knife mechanism; 51-purge pipeline; 511-air outlet; 52-gas pipeline; 53-control valve; 54-fixed frame; 60-Gas source. DETAILED DESCRIPTION

[0009] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0010] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0011] The embodiments of the present application are described in detail below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0012] In the related technology, under the three tunneling / poly preparation process paths of LPCVD / PECVD / POAPID, it is necessary to retain the BSG as the N+ side for tunneling deposition and the P+ side mask for poly, so the silicon wafer cannot be completely dehydrated in the slow pull tank of alkaline polishing.

[0013] Some methods of increasing dehydration in related technologies include: a. Using dehydration additives to assist dehydration. Its advantage is that it can effectively improve the EL / PL watermark problem, but its disadvantage is also obvious. Due to the introduction of additives, a liquid replenishing device needs to be added. At the same time, because the additives are added during slow pulling and there is no water tank later, the overall EL dirt / EL black spot ratio will be slightly higher by 0.5%~1%; b. Increasing the pure water temperature of the slow pulling tank to 45℃~65℃. Its advantage is that it is simple and convenient to operate, and you only need to change the parameters. Its disadvantage is that it cannot completely solve the watermark problem. At the same time, due to the increase in water temperature, the risk of EL dirt will increase under the mirror effect, and due to the increase in hot water usage, the energy consumption is relatively high.

[0014] Taking into account the above advantages and disadvantages, the slow pulling device in the embodiment of the present application can add a set of wind knife mechanisms 50 on both sides of the notch 11 of the pulling groove to achieve blowing during the lifting process of the flower basket 30 and the silicon wafer, thereby removing the water droplets between the basket teeth of the flower basket 30 and solving the problem of poor watermark.

[0015] refer to Figure 1 The embodiment of the present application discloses a slow pulling device for pulling a silicon wafer so that the silicon wafer can be immersed in a process liquid or pulled out from the process liquid, wherein the process liquid can be an alkali liquid, an acid liquid or the like. In the embodiment of the present application, the slow pulling device can be applied to an alkali polishing process. The disclosed slow pulling device includes a pulling tank 10, a pulling frame 20, a flower basket 30, a driving mechanism 40 and an air knife mechanism 50.

[0016] The flower basket 30 is a bearing member that can be used to bear silicon wafers. Optionally, the flower basket 30 can be provided with a plurality of slots and other structures to facilitate the clamping and fixing of the silicon wafers, ensure the stability of the silicon wafers during the process or lifting process, and prevent the silicon wafers from moving at will.

[0017] The lifting rack 20 is used to carry the flower basket 30, wherein the flower basket 30 can be arranged on the lifting rack 20. Optionally, one or more flower baskets 30 can be arranged on each lifting rack 20, and the lifting rack 20 can carry and fix the flower basket 30 to ensure the stability of the flower basket 30 during the lifting process.

[0018] The pulling tank 10 is used to contain process liquid so that the silicon wafers carried by the flower basket 30 can be processed in the pulling tank 10, such as alkali polishing. Among them, the pulling rack 20 is arranged in the pulling tank 10, so that the flower basket 30 carried by the pulling rack 20 and the silicon wafers carried by the flower basket 30 can be immersed in the process liquid in the pulling tank 10. Of course, after the process is completed, the pulling rack 20 can also be pulled out of the pulling tank 10, so that the silicon wafers carried by the flower basket 30 can be transported to the subsequent station for process treatment.

[0019] In order to achieve lifting, the driving mechanism 40 is connected to the lifting frame 20, which is used to drive the lifting frame 20 to lift and lower in the lifting tank 10, thereby driving the flower basket 30 and the silicon wafers it carries to lift and lower in the lifting tank 10, so that the silicon wafers can be immersed in the process liquid for process treatment, and the silicon wafers can also be separated from the process liquid after the process treatment.

[0020] Considering that when the lifting frame 20 and the flower basket 30 rise in the lifting trough 10, droplets will remain on the flower basket 30, and in the subsequent drying process, the droplets gradually slide down to form an oxide layer of a certain thickness, which is thicker than the area where no droplets slide down. In this way, after the finished battery is printed, an obvious watermark will be displayed on the EL / PL.

[0021] Based on the above situation, the slow pulling device in the embodiment of the present application may further include an air knife mechanism 50, the air outlet of which is arranged in a region close to the notch 11 of the pulling tank 10, for blowing gas to the flower basket 30 pulled out of the pulling tank 10 to blow off droplets attached to the flower basket 30. Optionally, the blowing gas may be nitrogen, and of course, may also be other gases, which are not specifically limited here.

[0022] Therefore, the slow pulling device in the embodiment of the present application can, by adding a wind knife mechanism 50, blow off the droplets attached to the flower basket 30 when the driving mechanism 40 lifts the pulling frame 20 and the flower basket 30 it carries from the pulling groove 10. Without using additives, it effectively alleviates the problem of the battery showing obvious watermarks on the EL / PL due to the residual droplets on the flower basket 30.

[0023] In some embodiments, the air knife mechanism 50 may include a purge pipeline 51, which is disposed above the slot 11, and in the first direction, the purge pipeline 51 is located on at least one side of the slot 11, and the purge pipeline 51 extends along the second direction, wherein the first direction, the second direction, and the lifting mode of the lifting rack 20 are perpendicular to each other. Exemplarily, the first direction may be the left-right direction, the second direction may be the front-back direction, and the lifting direction of the lifting rack 20 may be the up-down direction.

[0024] Furthermore, the purge pipeline 51 may be provided with a plurality of air outlets 511 , and the plurality of air outlets 511 are arranged along the second direction.

[0025] Based on the above arrangement, the embodiment of the present application can purge gas toward the direction of the slot 11 through the multiple air outlets 511 provided in the purge pipeline 51, so that an air curtain can be formed above the slot 11. When the lifting rack 20 pulls the flower basket 30 and the silicon wafers carried thereon out of the liquid surface, the flower basket 30 and the silicon wafers carried thereon will gradually enter the air curtain. Under the action of the air curtain, the liquid droplets adsorbed on the flower basket 30 and the silicon wafers will be blown away, thereby effectively preventing the occurrence of liquid droplets remaining on the surface of the flower basket 30.

[0026] In some embodiments, the purge line 51 can be arranged on one side of the slot 11 and located above the slot 11. In this case, the gas can be purged from one side of the slot 11 to the slot 11 through the purge line 51 on one side, so as to purge the droplets on the one side of the flower basket 30 and the silicon wafer. Of course, the purge line 51 can also be arranged on the opposite sides of the slot 11 and both are located above the slot 11. In this case, the gas can be purged from the two sides of the slot 11 to the slot 11 through the purge lines 51 on both sides, so as to purge the droplets on the two sides of the flower basket 30 and the silicon wafer. Of course, other arrangements are also possible, which are not specifically limited here.

[0027] Optionally, the purge pipe 51 can be a round tube, a square tube, etc. Of course, it can also be other shapes, which are not specifically limited here. In addition, the multiple air outlets 511 can be evenly arranged or unevenly arranged, which is specifically set according to actual working conditions.

[0028] In some embodiments, each air outlet 511 can be arranged to be inclined downward toward the center of the slot 11. In this way, the purge gas in the purge pipeline 51 can be blown toward the center of the slot 11 and inclined downward through multiple air outlets 511, so that the flower basket 30 and the wafers carried by it that are pulled out of the process liquid in the pulling tank 10 can be purged to blow off the attached droplets and prevent droplets from remaining.

[0029] Optionally, the angle between the extension direction of the center line of each air outlet 511 and the lifting direction can range from 30° to 60°, including, for example, 30°, 40°, 45°, 50°, 60°, etc. Of course, it can also be other degrees, which is not specifically limited here.

[0030] In some more specific embodiments, the angle may be set to be 45° tilted downward to facilitate blowing away the residual droplets on the flower basket 30 and the silicon wafer.

[0031] In some embodiments, the air knife mechanism 50 may include two purge pipes 51, which are arranged at intervals on both sides above the slot 11 along the first direction, and the air outlets 511 of the two purge pipes 51 are arranged toward the slot 11. Based on this arrangement, the two purge pipes 51 can be used to purge gas to both sides of the flower basket 30 and the silicon wafer, respectively, so as to improve the cleanliness and efficiency of the purge of the droplets; in addition, the purge gases on both sides can also check and balance each other to prevent the purge gas on one side from blowing the droplets away and escaping from the slot 11.

[0032] In some more specific embodiments, the air outlets 511 of the two purge pipelines 51 are arranged in one-to-one correspondence, which can improve the balance of air pressure to a certain extent.

[0033] In some embodiments, the air knife mechanism 50 may further include an air supply pipeline 52, which is respectively connected to the two purge pipelines 51 to supply purge gas to the two purge pipelines 51. Of course, when the air knife mechanism 50 includes one purge pipeline 51, the air supply pipeline 52 may also be connected to the purge pipeline 51 to supply purge gas to the purge pipeline 51.

[0034] In addition, one end of the gas delivery pipeline 52 away from the purge pipeline 51 can be connected to the gas source 60 to realize gas supply through the gas source 60. Optionally, the gas source 60 can be an air pump, a gas tank, etc. Of course, it can also be other forms, which are not specifically limited here.

[0035] Optionally, the gas delivery pipeline 52 may include a main pipeline and at least one branch pipeline, the main pipeline is connected to the at least one branch pipeline, and each branch pipeline is connected to the purge pipeline 51 respectively.

[0036] In order to realize the control of the gas pipeline 52, the air knife mechanism 50 may further include a control valve 53, which is arranged on the gas pipeline 52 and is used to control the on-off of the gas pipeline 52. Based on this configuration, the on-off control of the gas pipeline 52 can be realized by switching the control valve 53. Of course, the control valve 53 can also regulate the flow rate of the gas in the gas pipeline 52 to meet the purge requirements. Optionally, the control valve 53 may be a solenoid valve, etc., and of course, it may also be other forms, which are not specifically limited here.

[0037] When the air knife mechanism 50 includes a plurality of purge pipelines 51 , a plurality of branch pipelines respectively connected to the plurality of purge pipelines 51 are respectively provided with control valves 53 to control the on / off state or gas flow of each branch pipeline through the control valves 53 .

[0038] In some embodiments, the air knife mechanism 50 may further include a fixing frame 54, which is connected to the notch 11 of the lifting tank 10, and the purge pipeline 51 may be connected to the fixing frame 54. Based on this configuration, the fixing frame 54 may be used to support and fix the purge pipeline 51, which may ensure the stability of the purge pipeline 51 on the one hand, and may also enable the purge pipeline 51 to be located above the notch 11 on the other hand, so as to facilitate the purge of the flower basket 30 and the silicon wafer pulled to the notch 11.

[0039] Optionally, the fixing frame 54 may include a plurality of longitudinal beams, and each purge pipeline 51 may be connected to the notch 11 of the pulling tank 10 via at least one longitudinal beam.

[0040] In some embodiments, the driving mechanism 40 may include a base frame 41, a lifting drive member (not shown in the figure) and a lifting claw 42. The lifting drive member is disposed on the base frame 41, the lifting claw 42 is connected to the lifting frame 20, and the lifting drive member is connected to the lifting claw 42. Based on this configuration, under the driving action of the lifting drive member, the lifting claw 42 can move along the lifting direction, and the lifting claw 42 can drive the lifting frame 20 to move synchronously along the lifting direction, so as to realize the lifting and lowering of the flower basket 30 and the silicon wafer in the lifting tank 10.

[0041] Optionally, the base frame 41 can be an inverted L-shaped beam; the lifting drive component can be a winch or other components; the lifting claw 42 can include multiple hooks, which can be respectively hung in the hanging holes or hanging grooves provided on the lifting frame 20 through the multiple hooks, so as to make the connection or separation between the lifting claw 42 and the lifting frame 20 more convenient.

[0042] Based on the above-mentioned slow pulling device, an embodiment of the present application further discloses an alkali polishing device for solar cells. The disclosed alkali polishing device for solar cells includes the above-mentioned slow pulling device.

[0043] The embodiment of the present application can also provide a method for improving the watermark of Topcon batteries. By modifying the alkaline polishing equipment, air knife mechanisms 50 are added to both sides of the pulling trough 10, which can effectively remove the droplets remaining in the flower basket 30 caused by the hydrophilicity of BSG, thereby causing the Topcon battery to present droplet problems in EL / FL.

[0044] In addition, in the Topcon alkaline polishing process, the BSG on the P+ surface needs to be retained as a P+ surface bypass plating problem caused by the deposition of tunnel oxide layer and poly on the N+ surface. Therefore, the acid tank temperature of the alkaline polishing is relatively low. This results in the P+ surface always showing hydrophilicity due to the retention of BSG during alkaline polishing and dehydration.

[0045] When the flower basket 30 and the silicon wafers carried thereon are lifted upward in the pulling tank 10 , the flower basket 30 (eg, the teeth of the flower basket 30 ) gradually slides down during the drying process, resulting in a natural oxide layer of a certain thickness.

[0046] In the LPCVD process, due to the formation of a tunneling oxide layer, the natural oxide layer formed by the sliding of droplets is superimposed on the oxide layer formed during the process. The local oxide layer is thicker than the area where the dirty droplets slide. After the finished battery is printed, an obvious watermark problem will be shown on the EL / PL, which has become a common problem in the alkaline polishing process of Topcon batteries.

[0047] By adding a wind knife mechanism 50, the embodiment of the present application can use the purge gas to blow the residual droplets on the flower basket 30 and the wafer, thereby preventing obvious watermarks from being displayed on the EL / PL, and can also effectively alleviate the situation of using auxiliary products such as adding auxiliary agents to improve the situation, which is beneficial to improving environmental advantages.

[0048] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A slow pulling device, characterized in that: include: A lifting trough (10), a lifting frame (20), a flower basket (30), a driving mechanism (40) and an air knife mechanism (50); The flower basket (30) is arranged on the lifting frame (20) and is used to carry silicon wafers; The lifting frame (20) is arranged in the lifting groove (10), and the driving mechanism (40) is connected to the lifting frame (20) and is used to drive the lifting frame (20) to rise and fall in the lifting groove (10); The air outlet (511) of the air knife mechanism (50) is arranged in an area close to the notch (11) of the pulling groove (10), and is used to blow gas toward the flower basket (30) pulled out of the pulling groove (10) to blow off droplets attached to the flower basket (30).

2. The slow pulling device according to claim 1, characterized in that: The air knife mechanism (50) comprises a purge pipeline (51), the purge pipeline (51) being arranged above the slot (11), and in a first direction, the purge pipeline (51) is located on at least one side of the slot (11), and the purge pipeline (51) extends along a second direction, wherein the first direction, the second direction and the lifting direction of the lifting frame (20) are perpendicular to each other; The purge pipeline (51) is provided with a plurality of air outlets (511), and the plurality of air outlets (511) are arranged along the second direction.

3. The slow pulling device according to claim 2, characterized in that: Each of the air outlets (511) is arranged obliquely downward toward the center of the slot (11).

4. The slow pulling device according to claim 3, characterized in that: The angle between the extension direction of the center line of each air outlet (511) and the lifting direction is in the range of 30° to 60°.

5. The slow pulling device according to any one of claims 2 to 4, characterized in that: The air knife mechanism (50) comprises two purge pipelines (51), and the two purge pipelines (51) are arranged at intervals on both sides above the notch (11) along the first direction; The air outlets (511) of the two purge pipelines (51) are respectively arranged towards the direction of the slot (11).

6. The slow pulling device according to claim 5, characterized in that: The air knife mechanism (50) further comprises an air supply pipeline (52), wherein the air supply pipeline (52) is respectively connected to the two purge pipelines (51) and is used to supply purge gas to the two purge pipelines (51).

7. The slow pulling device according to claim 6, characterized in that: The air knife mechanism (50) further comprises a control valve (53), wherein the control valve (53) is arranged on the air supply pipeline (52) and is used to control the on-off of the air supply pipeline (52).

8. The slow pulling device according to claim 5, characterized in that: The wind knife mechanism (50) further comprises a fixing frame (54), wherein the fixing frame (54) is connected to the notch (11) of the lifting groove (10); The purge pipeline (51) is connected to the fixing frame (54).

9. The slow pulling device according to claim 1, characterized in that: The driving mechanism (40) comprises a base frame (41), a lifting driving member and a lifting claw (42); The lifting drive member is arranged on the base frame (41), the lifting claw (42) is connected to the lifting frame (20), and the lifting drive member is connected to the lifting claw (42).

10. An alkali polishing device for solar cells, characterized in that: A slow pulling device comprising any one of claims 1 to 9.

Images