A TBC battery preparation method and silicon wafer laser grooving device

Abstract

The invention discloses a TBC battery preparation method and a silicon wafer laser grooving device, which relates to the field of photovoltaic technology and aims to solve the technical problems of low yield and high cost of TBC battery production, including selecting an N-type single crystal silicon substrate, double-sided polishing, grooving, using ink to cover the boron doped area of ​​the silicon wafer after S04 treatment, and performing SiO2 treatment on the back of the silicon wafer after S05 treatment. 2 Deposition of tunneling layer and phosphorus-doped amorphous silicon layer, removal of SiO generated on the front and edge 2 , phosphorus diffusion treatment, removal of SiO on the edge and back 2 Protective layer, double-sided Al deposition 2 O 3 The present invention postpones the front texturing process backward, reduces the probability of front contamination, improves the yield, reduces the cost, and uses the PSG layer generated when the back side is doped with phosphorus as a barrier layer for front texturing. At the same time, by using an ink mask for shielding, the coating and stripping processes of the silicon nitride protective layer are reduced, the production cost is reduced, and the use of HF acid is reduced, thereby improving safety.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and more specifically to a TBC battery preparation method and a silicon wafer laser grooving device thereof. Background Art

[0002] The metal on the front of the TOPCon cell is in direct contact with the diffusion layer, which will produce a high carrier recombination; at the same time, the metal grid lines on the front will block the absorption and utilization of sunlight on the front of the cell. TBC (Tunneling oxide passivated Back Contact) cells transfer all the grid lines to the back of the cell to reduce the sun blocking on the front; at the same time, since there are no metal grid lines on the front, that is, no metal grid lines on the front are in contact with the substrate, the metal-semiconductor ohmic contact recombination loss on the front is reduced. At the same time, all metal grid lines are not in direct contact with the substrate, but in contact with the doping layer on the back surface of the substrate, reducing the metal-semiconductor contact recombination on the front and improving efficiency.

[0003] The existing TBC battery has a silicon nitride protective layer coating and stripping process during the production process, and HF acid is used more frequently. In addition, the probability of the front of the TBC battery being contaminated during the production process is high, the TBC battery yield is low, and the production cost is high. In view of this, we propose a TBC battery preparation method and a silicon wafer laser grooving device. Summary of the invention

[0004] The object of the present invention is to provide a TBC battery preparation method and a silicon wafer laser grooving device thereof, so as to solve the technical problems of low yield and high cost in TBC battery production.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for preparing a TBC battery, comprising the following steps:

[0006] S01: Select an N-type single crystal silicon substrate;

[0007] The N-type single crystal silicon substrate has a resistivity of 1 to 20 Ω·cm and a thickness of 50 to 300 um;

[0008] S02: Double-sided polishing;

[0009] Using a trough-type device, the selected N-type single crystal silicon substrate is subjected to double-sided polishing;

[0010] S03: preparing a SiO2 tunneling layer and a boron-doped polysilicon layer (Poly-Si(p+));

[0011] Using PECVD equipment, N2O is selected as the raw material gas for preparing SiO2, CH4 / H2 / BH3 is selected as the raw material gas for boron doping, and the square resistance after doping is 100-200Ω. The silicon wafer after boron doping is annealed to crystallize the deposited boron doped amorphous silicon layer;

[0012] S04: slotting;

[0013] The silicon wafer after S03 is laser grooved, and the BSG layer and the wrapping of the non-boron doped surface are removed. The laser wavelength range is 100-1200nm. When removing the wrapping of the non-boron doped surface, a tank cleaning device is used to etch with alkaline solution, and the damaged layer at the laser groove is removed at the same time to reduce the defect recombination center at the groove.

[0014] S05: For the silicon wafer treated in S04, the boron doped area is covered with ink and dried to prevent contamination of the boron diffusion area during subsequent phosphorus diffusion;

[0015] The ink is deposited by spraying or coating. The ink width needs to be precisely controlled. It should completely cover the boron diffusion area, but not be too wide. Too wide will easily lead to a large gap in the PN junction area, affecting the passivation effect and overall efficiency of the silicon wafer. The difference between the ink width and the width of the boron doping area is 0-1mm (the ink overflow width on the left and right sides of the boron doping area should be consistent);

[0016] S06: depositing a back SiO2 tunneling layer and a phosphorus-doped amorphous silicon layer on the silicon wafer after S05;

[0017] Using PECVD equipment, N2O is selected as the raw material gas for preparing SiO2, and CH4 / H2 / PH3 is selected as the raw material gas for phosphorus doping. The square resistance after doping is 20-200Ω. The phosphorus-doped silicon wafer is annealed to crystallize the deposited phosphorus-doped amorphous silicon layer, and oxygen is introduced to form a PSG layer on the back of the silicon wafer;

[0018] S07: Remove SiO2 generated on the front and edge;

[0019] Use chain equipment to remove SiO2 generated on the front and edge of the silicon wafer in step S06, and use trough equipment to remove the wrapping. At the same time, use trough texturing equipment to texturing the silicon wafer after S05, so that a textured anti-reflection velvet surface is formed on the front of the silicon wafer. The back is protected by the PSG layer and will not be corroded by the alkali solution in the texturing tank. After texturing, the silicon wafer is cleaned with HF acid to remove the PSG layer on the back and then dried.

[0020] S08: Phosphorus diffusion treatment;

[0021] The front side of the silicon wafer treated with S07 is subjected to phosphorus diffusion treatment, and the diffusion square resistance is controlled at 100-200Ω; oxygen is introduced to form a SiO2 protective layer on the front side of the silicon wafer;

[0022] S09: Remove the SiO2 protective layer on the edge and back;

[0023] Use chain equipment to remove the SiO2 protective layer on the edge and back of the silicon wafer after S08, and continue to use trough equipment to etch and remove the expansion in step S08. At the same time, use the solubility of alkali liquid to remove the ink printed in step S05, isolate the phosphorus and boron doped area on the back, and then use HF acid to clean the SiO2 protective layer on the front of the silicon wafer;

[0024] S10: double-sided deposition of Al2O3;

[0025] ALD was used to deposit Al2O3 on both sides with a thickness of 2-10nm, and TMA and H2O were selected as the reaction gases for AlOx deposition;

[0026] S11: double-sided SiNx deposition;

[0027] Use PECVD equipment to deposit SiNx on both sides of silicon wafers with a thickness of 20-150nm; use SiH4 and NH3 as the reaction gases for SiNx deposition;

[0028] S12: Printing, sintering and testing;

[0029] The silicon wafer after S11 is printed and sintered to form a conductive grid line, and a grading test is performed to obtain a TBC battery. The present invention postpones the front texturing process backward, reduces the probability of front contamination, improves the yield, and reduces the cost. The PSG layer generated when the back side is phosphorus doped is used as a barrier layer for front texturing. At the same time, the coating and stripping processes of the silicon nitride protective layer are reduced by using an ink mask for shielding, thereby reducing the production cost, reducing the use of HF acid, and improving safety.

[0030] Preferably, in step S01, the resistivity of the N-type silicon wafer is in the range of 0.7-2.1Ω·cm, and the thickness is 130um;

[0031] In step S02, the laser wavelength range is 500-600nm,

[0032] In step S03, the square resistance is controlled to be 120-150Ω after boron doping;

[0033] In step S05, the ink width is greater than the boron doping region width by 0.5 mm;

[0034] In step S06, the square resistance after phosphorus doping is 40-60Ω;

[0035] In step S08, the diffusion square resistance is controlled at 150-180Ω;

[0036] In step S010, the AlOx deposition thickness is 5 nm;

[0037] In step S011, the SiNx deposition thickness is 60-80 nm.

[0038] Preferably, in step S04, the silicon wafer laser slotting device comprises a base, a Y-axis moving mechanism is arranged in the gap of the base, a placement mechanism with a positioning function is fixedly arranged at the movable end of the Y-axis moving mechanism, a U-shaped support seat is fixedly arranged on one side of the top end of the base, an X-axis moving mechanism is fixedly arranged on the U-shaped support seat, a Z-axis moving mechanism is fixedly arranged at the movable end of the X-axis moving mechanism, a mounting plate is fixedly arranged at the movable end of the Z-axis moving mechanism, a laser slotting mechanism is fixedly arranged in the middle of the mounting plate, and a reflecting mechanism is arranged at the bottom end of the laser slotting mechanism;

[0039] The reflection mechanism includes a reciprocating rotating mechanism, an intermittent rotating mechanism is arranged on the reciprocating rotating mechanism, the input end of the reciprocating rotating mechanism is connected to the output end of the intermittent rotating mechanism, and a refraction mechanism is also arranged on the reciprocating rotating mechanism. The present invention performs laser grooving on the silicon wafer after S03 through the structural design of the silicon wafer laser grooving device, and uses a reflection mechanism to reflect the laser emitted by the laser grooving mechanism, and grooves the side of the groove so that the side of the groove forms a concave surface. When the boron-doped area of ​​the silicon wafer after S04 is shielded with ink, the ink is reduced from falling along the vertical groove edge, thereby facilitating the spraying or coating of the ink evenly.

[0040] Preferably, the Y-axis moving mechanism, the X-axis moving mechanism and the Z-axis moving mechanism are all screw moving structures, and a rotating cavity is opened at the bottom of the mounting plate.

[0041] Preferably, the placement mechanism includes a placement seat and a motor A. The placement seat is fixedly arranged at the movable end of the Y-axis moving mechanism. A slide groove A is opened in the middle part of the placement seat along the X-axis. Two sliders A are slidably connected on the slide groove A in a symmetrical structure. A positioning bar is fixedly arranged on the top of the slider A. An opposing screw rod is rotatably connected in the slide groove A. The slider A is threadedly connected to the opposing screw rod. The motor A is fixedly arranged on one side of the placement seat relative to the opposing screw rod. The opposing screw rod passes through the placement seat at one end close to the motor A and is fixedly connected to the output shaft of the motor A.

[0042] Preferably, the reciprocating rotating mechanism includes a mounting seat and a rotating shaft A, the mounting seat is fixedly arranged at one end of the mounting plate away from the laser slotting mechanism, a U-shaped seat is fixedly arranged on the mounting seat, a connecting shaft is rotatably connected to the transverse arm of the U-shaped seat, a turntable A is rotatably connected to the bottom end of the connecting shaft, a translation unit is arranged on the turntable A, the rotating shaft A is rotatably arranged on the mounting seat relative to the position of the laser slotting mechanism, a sliding through groove is arranged on the rotating shaft A, a round rod is arranged above the rotating shaft A, connecting seats are fixedly arranged at both ends of the round rod, the connecting seat is fixedly connected to the rotating shaft A, a movable block is sleeved on the round rod, a movable rod is rotatably connected to the top of the movable block, and the movable rod is movably connected to the movable end of the translation unit.

[0043] Preferably, a slide groove B is provided on the turntable A, a round groove is provided on the outer edge surface of the turntable A at a position opposite to the slide groove B, the round groove is connected with the slide groove B, and a mounting cavity is provided in the middle of the round groove.

[0044] Preferably, the translation unit includes a slider B, a screw, a worm wheel and a worm, the slider B is slidably arranged on the slide groove B, the slider B is provided with a movable circular groove, the movable rod is movably connected to the movable circular groove, the screw is arranged in the circular through groove, the end of the screw close to the slider B penetrates into the slide groove B and is fixedly connected to the slider B, the worm wheel is rotatably arranged on the installation cavity, the worm wheel is provided with a threaded groove, the threaded groove is threadedly connected to the screw, the worm is rotatably arranged on the installation cavity relative to the worm wheel position, the top end of the worm passes through the turntable A and is fixedly provided with an adjustment block.

[0045] Preferably, the intermittent rotation mechanism includes a turntable B, a rotating shaft B and a motor B. The turntable B is fixedly arranged at the top of the connecting shaft. The turntable B is provided with a plurality of movable grooves in a circular equidistant mechanism. A limiting arc groove is provided at any two adjacent movable groove gap positions. The rotating shaft B is rotatably arranged at the top of the U-shaped seat relative to the position of the turntable B. A circular block is fixedly arranged at the top of the rotating shaft B, and the circular block is movably matched with the limiting arc groove. A turntable C is fixedly arranged at the top of the circular block. A movable column is fixedly arranged at the bottom of the turntable C relative to the position of the movable groove, and the movable column is movably matched with the movable groove. The motor B is fixedly arranged on the mounting seat relative to the position of the turntable C, and the output shaft of the motor B is fixedly connected to the top of the turntable C.

[0046] Preferably, the refraction mechanism includes a slide bar, a rotating seat and a motor C, the slide bar is slidably arranged on the sliding through groove, the slide bar passes through the rotating cavity at one end close to the laser slotting mechanism and is fixedly provided with a reflection block, a tooth groove is provided at the top end of the slide bar away from the laser slotting mechanism, the rotating seat is fixedly provided on the mounting seat relative to the tooth groove, a rotating shaft C is rotatably connected to the rotating seat, a ball gear is fixedly provided on the rotating shaft C, the tooth groove is adapted to the ball gear, and the tooth groove is movably connected to the ball gear, the motor C is fixedly provided on the mounting seat relative to the rotating shaft C, and the rotating shaft C passes through the rotating seat and the mounting seat at one end away from the ball gear in sequence and is fixedly connected to the output shaft of the motor C.

[0047] Preferably, the reflective block is in an isosceles triangle structure.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. The present invention postpones the front texturing process backward, reduces the probability of the front side being contaminated, improves the yield, reduces the cost, and uses the PSG layer generated during the back side phosphorus doping as a barrier layer for front texturing. At the same time, by using an ink mask for shielding, the coating and stripping processes of the silicon nitride protective layer are reduced, the production cost is reduced, and the use of HF acid is reduced, thereby improving safety.

[0050] 2. The present invention performs laser grooving on silicon wafers after S03 through the structural design of a silicon wafer laser grooving device, and utilizes a reflection mechanism to reflect the laser emitted by the laser grooving mechanism to groove the sides of the grooves, so that the sides of the grooves form concave surfaces. When ink is used to shield the boron-doped areas of the silicon wafers after S04 treatment, the ink is reduced from falling along the vertical groove edges, thereby facilitating uniform spraying or coating of the ink.

[0051] 3. The invention adopts the design of the placement mechanism, so that the rotation of the output shaft of the motor A can be controlled by an external control mechanism to drive the opposite screws to rotate, so that the two sliders A move in opposite directions along the slide groove A, thereby positioning the silicon wafer on the placement seat to the middle of the placement seat, which is convenient for the laser slotting mechanism to slot and ensure the accuracy of the slotting position.

[0052] 4. The present invention designs a reflection mechanism so that the slider can make intermittent reciprocating rotational motion along with the rotating shaft A, and the tooth groove intermittently reciprocates along the ball gear, so that the reflection block also makes intermittent reciprocating rotational motion. When the reflection block rotates, the reflected laser angle is intermittently offset, so that the laser angle can open uniform concave and convex grooves on the side of the groove, which is convenient for spraying or coating the ink evenly and not easy to fall off. The output shaft of the motor C is controlled to rotate by an external control mechanism, and the rotating shaft C drives the ball gear to rotate, so that the slider can slide along the sliding groove. When the silicon wafer after S03 is laser grooved, the reflection block can be driven to move by the slider to avoid the reflection block blocking the laser emitted by the laser groove mechanism. When the side of the groove needs to be further processed, the reflection block is driven to move to the bottom of the output end of the laser groove mechanism by the slider.

[0053] 5. The present invention further designs the translation unit so that when the translation unit rotates, the movable rod moves in the movable circular groove, the movable block reciprocates along the circular rod, and causes the circular rod to drive the rotating shaft A to make reciprocating rotation motion, and the worm can be driven to rotate by rotating the worm, so that the screw drives the slider B to slide along the slide groove B, causing the eccentric position of the slider B to change, thereby changing the reciprocating rotation angle of the rotating shaft A, so as to adapt to the groove side processing of different groove depths, thereby improving functionality, and through the structural design of the worm gear, the eccentric position of the slider B can be adjusted more accurately.

[0054] 6. The present invention arranges the reflective block in an isosceles triangle structure so that when uniform concave-convex grooves are processed on the two sides of the middle groove, the two sides of the reflective block can reflect two lasers and process the two sides of the middle groove at the same time, thereby improving the production efficiency of the TBC battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of the preparation process of the preparation method of the present invention;

[0056] Figure 2 It is a schematic diagram of the preparation process of the preparation method of the present invention;

[0057] Figure 3 A schematic diagram of a use state of the laser slotting device of the present invention;

[0058] Figure 4 It is a schematic diagram of the exploded structure of the placement mechanism of the present invention;

[0059] Figure 5 It is a schematic diagram of the structure of the mounting plate, the laser slotting mechanism and the reflection mechanism of the present invention;

[0060] Figure 6 for Figure 4 Schematic diagram of the laser path structure in the reflection state;

[0061] Figure 7 It is a schematic diagram of the structure of the reflection mechanism of the present invention;

[0062] Figure 8 for Figure 6 Explosion diagram of some structures;

[0063] Fig. 9 It is a schematic diagram of the ball gear structure of the present invention;

[0064] Fig.10 for Figure 7 Schematic diagram of some structures;

[0065] Fig.11 for Fig. 9 A magnified schematic diagram of the local structure;

[0066] Fig.12 It is a structural schematic diagram of the refraction mechanism of the present invention.

[0067] Description of the numbers in the figure:

[0068] 1. Base; 2. Y-axis moving mechanism; 3. Placement mechanism; 4. U-shaped support seat; 5. X-axis moving mechanism; 6. Z-axis moving mechanism; 7. Mounting plate; 8. Laser slotting mechanism; 9. Reflection mechanism;

[0069] 31. Placement seat; 32. Slide groove A; 33. Slider A; 34. Positioning bar; 35. Opposite screw rod; 36. Motor A;

[0070] 71. Rotating cavity;

[0071] 91. Reciprocating rotating mechanism; 92. Intermittent rotating mechanism; 93. Refraction mechanism;

[0072] 911, mounting seat; 912, U-shaped seat; 913, connecting shaft; 914, turntable A; 915, translation unit; 916, rotating shaft A; 917, sliding groove; 918, round rod; 919, connecting seat; 910, movable block; 9101, movable rod;

[0073] 921, turntable B; 922, movable slot; 923, limit arc slot; 924, rotating shaft B; 925, circular block; 926, turntable C; 927, movable column; 928, motor B;

[0074] 931, slide bar; 932, reflection block; 933, tooth groove; 934, rotating seat; 935, rotating shaft C; 936, ball gear; 937, motor C;

[0075] 9141, slide groove B; 9142, round groove; 9143, installation cavity;

[0076] 9151. Slider B; 9152. Movable circular groove; 9153. Screw; 9154. Worm wheel; 9155. Threaded groove; 9156. Worm; 9157. Adjustment block. DETAILED DESCRIPTION

[0077] like Figures 1 to 12 As shown, the present invention relates to a TBC battery preparation method, comprising the following steps:

[0078] S01: Select an N-type single crystal silicon substrate;

[0079] The N-type single crystal silicon substrate has a resistivity of 1 to 20 Ω·cm and a thickness of 50 to 300 um;

[0080] S02: Double-sided polishing;

[0081] Using a trough-type device, the selected N-type single crystal silicon substrate is subjected to double-sided polishing;

[0082] S03: preparing a SiO2 tunneling layer and a boron-doped polysilicon layer (Poly-Si(p+));

[0083] Using PECVD equipment, N2O is selected as the raw material gas for preparing SiO2, CH4 / H2 / BH3 is selected as the raw material gas for boron doping, and the square resistance after doping is 100-200Ω, wherein the boron doping square resistance is optimally controlled at 120-150Ω, and the silicon wafer after boron doping is annealed to crystallize the deposited boron doped amorphous silicon layer;

[0084] S04: slotting;

[0085] The silicon wafer after S03 is subjected to laser grooving treatment, and the BSG layer and the wrapping of the non-boron doped surface are removed, wherein the laser wavelength range is 100-1200nm, and the optimal range is 500-600nm. When removing the wrapping of the non-boron doped surface, a tank cleaning device is used, and alkaline solution is used for corrosion, and at the same time, the damaged layer at the laser grooving is removed to reduce the defect recombination center at the grooving. The thickness of the tunneling layer is 1.4nm, and the thickness of the doped amorphous silicon layer is 110nm;

[0086] S05: For the silicon wafer treated in S04, the boron doped area is covered with ink and dried to prevent contamination of the boron diffusion area during subsequent phosphorus diffusion;

[0087] The ink is deposited by spraying or coating. The ink width needs to be precisely controlled. It should completely cover the boron diffusion area, but not too wide. Too wide will easily lead to a large gap in the PN junction area, affecting the passivation effect and overall efficiency of the silicon wafer. The difference between the ink width and the width of the boron doping area is 0-1mm (the ink overflow width on the left and right sides of the boron doping area should be consistent). The best ink width is 0.5mm larger than the width of the boron doping area.

[0088] S06: depositing a back SiO2 tunneling layer and a phosphorus-doped amorphous silicon layer on the silicon wafer after S05;

[0089] Using PECVD equipment, N2O is selected as the raw material gas for preparing SiO2, CH4 / H2 / PH3 is selected as the raw material gas for phosphorus doping, and the square resistance after doping is 20-200Ω, among which the best square resistance of phosphorus doping is 40-60Ω. The silicon wafer after phosphorus doping is annealed to crystallize the deposited phosphorus doped amorphous silicon layer, and oxygen is introduced to form a PSG layer on the back of the silicon wafer;

[0090] S07: Remove SiO2 generated on the front and edge;

[0091] Use chain equipment to remove SiO2 generated on the front and edge of the silicon wafer in step S06, and use trough equipment to remove the wrapping. At the same time, use trough texturing equipment to texturing the silicon wafer after S05, so that a textured anti-reflection velvet surface is formed on the front of the silicon wafer. The back is protected by the PSG layer and will not be corroded by the alkali solution in the texturing tank. After texturing, the silicon wafer is cleaned with HF acid to remove the PSG layer on the back and then dried.

[0092] S08: Phosphorus diffusion treatment;

[0093] The front side of the silicon wafer treated with S07 is subjected to phosphorus diffusion treatment, and the diffusion square resistance is controlled at 100-200Ω; among which, the best square resistance is 150-180Ω, and oxygen is introduced to form a SiO2 protective layer on the front side of the silicon wafer;

[0094] S09: Remove the SiO2 protective layer on the edge and back;

[0095] Use chain equipment to remove the SiO2 protective layer on the edge and back of the silicon wafer after S08, and continue to use trough equipment to etch and remove the expansion in step S08. At the same time, use the solubility of alkali liquid to remove the ink printed in step S05, isolate the phosphorus and boron doped area on the back, and then use HF acid to clean the SiO2 protective layer on the front of the silicon wafer;

[0096] S10: double-sided deposition of Al2O3;

[0097] ALD was used to deposit Al2O3 on both sides with a thickness of 2-10nm. TMA and H2O were selected as the reaction gases for AlOx deposition, wherein the optimal AlOx deposition thickness was 5nm.

[0098] S11: double-sided SiNx deposition;

[0099] Use PECVD equipment to deposit SiNx on both sides of the silicon wafer with a thickness of 20-150nm; select SiH4 and NH3 as the reaction gas for SiNx deposition, where the optimal SiNx deposition thickness is 60-80nm;

[0100] S12: Printing, sintering and testing;

[0101] The silicon wafer after S11 is printed and sintered to form conductive grid lines, and then subjected to grading tests to produce TBC batteries.

[0102] In step S04, the silicon wafer laser slotting device includes a base 1, a Y-axis moving mechanism 2 is arranged in the gap of the base 1, a placement mechanism 3 with a positioning function is fixedly arranged at the movable end of the Y-axis moving mechanism 2, a U-shaped support seat 4 is fixedly arranged on one side of the top of the base 1, an X-axis moving mechanism 5 is fixedly arranged on the U-shaped support seat 4, a Z-axis moving mechanism 6 is fixedly arranged at the movable end of the X-axis moving mechanism 5, a mounting plate 7 is fixedly arranged at the movable end of the Z-axis moving mechanism 6, a laser slotting mechanism 8 is fixedly arranged in the middle of the mounting plate 7, and a reflection mechanism 9 is arranged at the bottom end of the laser slotting mechanism 8;

[0103] The reflection mechanism 9 includes a reciprocating rotating mechanism 91, an intermittent rotating mechanism 92 is arranged on the reciprocating rotating mechanism 91, the input end of the reciprocating rotating mechanism 91 is connected to the output end of the intermittent rotating mechanism 92, and a refraction mechanism 93 is also arranged on the reciprocating rotating mechanism 91. Among them, the laser slotting mechanism 8 is a prior art and will not be described in detail here. Through the above arrangement, the present invention enables the laser slotting mechanism 8 to perform laser slotting processing on the silicon wafer after S03.

[0104] In the embodiment of the present invention, the Y-axis moving mechanism 2, the X-axis moving mechanism 5 and the Z-axis moving mechanism 6 are all screw moving structures, and a rotating cavity 71 is provided at the bottom of the mounting plate 7. The screw moving structure is a prior art and will not be described in detail.

[0105] In an embodiment of the present invention, the placement mechanism 3 includes a placement seat 31 and a motor A36. The placement seat 31 is fixedly arranged at the movable end of the Y-axis moving mechanism 2. A slide groove A32 is provided in the middle of the placement seat 31 along the X-axis. Two sliders A33 are slidably connected on the slide groove A32 in a symmetrical structure. A positioning bar 34 is fixedly arranged at the top of the slider A33. An opposing screw rod 35 is rotatably connected in the slide groove A32. The slider A33 is threadedly connected to the opposing screw rod 35. The motor A36 is fixedly arranged on one side of the placement seat 31 relative to the opposing screw rod 35. The opposing screw rod 35 passes through the placement seat 31 near one end of the motor A36 and is fixedly connected to the output shaft of the motor A36. The present invention is designed to control the rotation of the output shaft of the motor A36 through an external control mechanism to drive the opposing screw rod 35 to rotate, so that the two sliders A33 move in opposite directions along the slide groove A32, thereby positioning the silicon wafer on the placement seat 31 to the middle of the placement seat 31, which is convenient for the laser slotting mechanism 8 to slot and ensure the accuracy of the slotting position.

[0106] In an embodiment of the present invention, the reciprocating rotating mechanism 91 includes a mounting seat 911 and a rotating shaft A916. The mounting seat 911 is fixedly arranged at one end of the mounting plate 7 away from the laser slotting mechanism 8. A U-shaped seat 912 is fixedly arranged on the mounting seat 911. A connecting shaft 913 is rotatably connected to the transverse arm of the U-shaped seat 912. A turntable A914 is rotatably connected to the bottom end of the connecting shaft 913. A translation unit 915 is arranged on the turntable A914. The rotating shaft A916 is rotatably arranged on the mounting seat 911 relative to the laser slotting mechanism 8. A sliding through groove 917 is provided on the rotating shaft A916. A round rod 918 is provided above the rotating shaft A916. Connecting seats 919 are fixedly arranged at both ends of the round rod 918. The connecting seat 919 is fixedly connected to the rotating shaft A916. A movable block 910 is sleeved on the round rod 918. A movable rod 9101 is rotatably connected to the top of the movable block 910. The movable rod 9101 is movably connected to the movable end of the translation unit 915. The present invention adopts the design of the reciprocating rotating mechanism 91 so that the rotation of the connecting shaft 913 can drive the rotating disk A914 to rotate, thereby causing the translation unit 915 to rotate.

[0107] In an embodiment of the present invention, a slide groove B9141 is provided on the turntable A914, and a circular groove 9142 is provided on the outer edge surface of the turntable A914 relative to the slide groove B9141. The circular groove 9142 is connected to the slide groove B9141, and an installation cavity 9143 is provided in the middle of the circular groove 9142.

[0108] In an embodiment of the present invention, the translation unit 915 includes a slider B9151, a screw 9153, a worm wheel 9154 and a worm 9156. The slider B9151 is slidably arranged on the slide groove B9141. The slider B9151 is provided with a movable circular groove 9152. The movable rod 9101 is movably connected to the movable circular groove 9152. The screw 9153 is arranged in the circular through groove 9142. The end of the screw 9153 close to the slider B9151 penetrates into the slide groove B9141 and is fixedly connected to the slider B9151. The worm wheel 9154 is rotatably arranged on the installation cavity 9143. The worm wheel 9154 is provided with a threaded groove 9155. The threaded groove 9155 is threadedly connected to the screw 9153. The worm 9156 is rotatably arranged on the installation cavity 9143 relative to the position of the worm wheel 9154. The top end of the worm 9156 passes through the turntable A914 and is fixedly provided with an adjustment block 9157. The present invention further designs the translation unit 915 so that when the translation unit 915 rotates, the movable rod 9101 moves in the movable circular groove 9152, and the movable block 910 rotates back and forth along the circular rod 918, causing the circular rod 918 to drive the rotating shaft A916 to perform reciprocating rotation motion, and the worm wheel 9154 can be driven to rotate by rotating the worm 9156, so that the screw rod 9153 drives the slider B9151 to slide along the slide groove B9141, causing the eccentric position of the slider B9151 to change, thereby changing the reciprocating rotation angle of the rotating shaft A916, and through the structural design of the worm gear, the eccentric position of the slider B9151 can be adjusted more accurately.

[0109] In an embodiment of the present invention, the intermittent rotating mechanism 92 includes a turntable B921, a rotating shaft B924 and a motor B928. The turntable B921 is fixedly mounted on the top of the connecting shaft 913. A plurality of movable grooves 922 are provided in a circular equidistant mechanism on the turntable B921. A limiting arc groove 923 is provided at the gap position between any two adjacent movable grooves 922. The rotating shaft B924 is rotatably mounted on the top of the U-shaped seat 912 relative to the position of the turntable B921. A circular block 925 is fixedly mounted on the top of the rotating shaft B924. The circular block 925 is movably matched with the limiting arc groove 923. A turntable C926 is fixedly mounted on the top of the circular block 925. A movable column 927 is fixedly mounted on the bottom of the turntable C926 relative to the position of the movable groove 922. The movable column 927 is movably matched with the movable groove 922. The motor B928 is fixedly mounted on the mounting seat 911 relative to the position of the turntable C926. The output shaft of the motor B928 is fixedly connected to the top of the turntable C926. The present invention, through the structural design of the intermittent rotating mechanism 92, drives the output shaft of the motor B928 to rotate through an external control mechanism, which can drive the turntable C926 to rotate, thereby rotating the movable column 927 and the circular segment block 925. The movable column 927 rotates to move in the movable groove 922, driving the turntable B921 to rotate. When the movable column 927 is disengaged from the movable groove 922, the circular segment block 925 moves into one of the limiting arc grooves 923 to limit the limiting arc groove 923, preventing the turntable B921 from self-rotating under the action of inertia, thereby ensuring the stability of the linkage, until the movable column 927 rotates into the next movable groove 922, and so on and so forth, causing the turntable B921 to rotate and perform intermittent rotational motion.

[0110] In an embodiment of the present invention, the refraction mechanism 93 includes a slide bar 931, a rotating seat 934 and a motor C937. The slide bar 931 is slidably arranged on the sliding groove 917. The end of the slide bar 931 close to the laser slotting mechanism 8 passes through the rotating cavity 71 and is fixedly provided with a reflection block 932. A tooth groove 933 is provided at the top of the slide bar 931 away from the laser slotting mechanism 8. The rotating seat 934 is fixedly provided on the mounting seat 911 relative to the tooth groove 933. A rotating shaft C935 is rotatably connected to the rotating seat 934. A ball gear 936 is fixedly provided on the rotating shaft C935. The tooth groove 933 is adapted to the ball gear 936, and the tooth groove 933 is movably connected to the ball gear 936. The motor C937 is fixedly provided on the mounting seat 911 relative to the rotating shaft C935. The end of the rotating shaft C935 away from the ball gear 936 passes through the rotating seat 934 and the mounting seat 911 in sequence and is fixedly connected to the output shaft of the motor C937. The present invention sets a refraction mechanism 93 so that the slide bar 931 can make intermittent reciprocating rotational motion along with the rotating shaft A916, and the tooth groove 933 intermittently reciprocates along the ball gear 936, so that the reflection block 932 also makes intermittent reciprocating rotational motion. When the reflection block 932 rotates, the reflected laser angle is intermittently offset, so that the laser angle can open uniform concave and convex grooves on the side of the groove, which is convenient for spraying or coating the ink evenly and not easy to fall off. The output shaft of the motor C937 is controlled to rotate by an external control mechanism, and the rotating shaft C935 drives the ball gear 936 to rotate, so that the slide bar 931 can slide along the sliding groove 917. When the silicon wafer after S03 is laser grooved, the slide bar 931 can drive the reflection block 932 to move to avoid the reflection block 932 blocking the laser emitted by the laser groove mechanism 8. When the side of the groove needs to be further processed, the slide bar 931 drives the reflection block 932 to move to the bottom of the output end of the laser groove mechanism 8.

[0111] In the embodiment of the present invention, the reflective block 932 is an isosceles triangle structure.

[0112] The present invention arranges the reflective block 932 to be an isosceles triangle structure, so that when uniform concave-convex grooves are processed on the two sides of the middle groove, the two sides of the reflective block 932 can reflect two lasers and process the two sides of the middle groove at the same time, thereby improving the production efficiency of the TBC battery.

[0113] Working principle: This embodiment provides a TBC battery preparation method and a silicon wafer laser grooving device, which postpones the front texturing process backward, reduces the probability of front contamination, improves the yield, and reduces the cost. The PSG layer generated during back phosphorus doping is used as a barrier layer for front texturing. At the same time, by using an ink mask for shielding, the coating and stripping processes of the silicon nitride protective layer are reduced, the production cost is reduced, and the use of HF acid is reduced, thereby improving safety.

[0114] When the silicon wafer after S03 is laser grooved and the side of the groove is grooved, first, the reciprocating rotation angle of the reflective block 932 is adjusted according to the groove depth, and the rotating worm 9156 is driven to rotate by the rotating adjustment block 9157, so that the worm wheel 9154 rotates, so that the screw 9153 drives the slider B9151 to slide along the slide groove B9141, causing the eccentric position of the slider B9151 to change, thereby changing the reciprocating rotation angle of the rotating shaft A916, and then changing the reciprocating rotation angle of the reflective block 932;

[0115] The output shaft of the motor C937 is controlled to rotate by an external control mechanism, and the rotating shaft C935 drives the ball gear 936 to rotate, so that the slide bar 931 slides along the sliding groove 917. When the silicon wafer after S03 is laser grooved, the reflective block 932 can be driven by the slide bar 931 to move to the position directly below the output end of the laser groove mechanism 8;

[0116] By driving the output shaft of the motor B928 to rotate through an external control mechanism, the turntable C926 can be driven to rotate, thereby rotating the movable column 927 and the circular segment block 925. The rotation of the movable column 927 allows it to move in the movable groove 922, driving the turntable B921 to rotate. When the movable column 927 is disengaged from the movable groove 922, the circular segment block 925 moves into one of the limiting arc grooves 923 to limit the limiting arc groove 923, preventing the turntable B921 from self-rotating under the action of inertia, thereby ensuring the stability of the linkage, until the movable column 927 rotates into the next movable groove 922, and so on and so forth, causing the turntable B921 to rotate and perform intermittent rotational motion, and the movable rod 9101 moves in the movable circular groove 9152. The block 910 intermittently reciprocates along the round rod 918, and causes the round rod 918 to drive the rotating shaft A916 to do intermittent reciprocating rotational motion, so that the slide bar 931 can intermittently reciprocate along with the rotating shaft A916, and the tooth groove 933 intermittently reciprocates along the ball gear 936, so that the reflective block 932 also intermittently reciprocates. When the reflective block 932 rotates, the reflected laser angle is intermittently offset, so that the laser angle can open a uniform concave-convex groove on the side of the groove, which is convenient for the ink to be sprayed or coated evenly and not easy to fall off; wherein, when the uniform concave-convex grooves are processed on the two sides of the middle groove, the two sides of the reflective block 932 can reflect two lasers, and the two sides of the middle groove are processed at the same time;

[0117] When the groove sides are processed, the output shaft of the motor C937 is controlled to rotate by an external control mechanism, and the shaft C935 drives the ball gear 936 to rotate, so that the slide bar 931 slides along the sliding groove 917. When the silicon wafer after S03 is laser grooved, the slide bar 931 can drive the reflection block 932 to move to avoid the reflection block 932 blocking the laser emitted by the laser groove mechanism 8.

[0118] The embodiments of the present invention disclose preferred embodiments, but are not limited thereto. A person skilled in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a TBC battery, wherein the TBC battery comprises, from the front surface to the back surface of the battery, an anti-reflection layer, an AlO x layer, phosphorus diffusion layer, C-Si(n) substrate, SiO2 tunneling layer, phosphorus-doped polysilicon layer (Poly-Si(n + ))& Boron-doped polysilicon layer (Poly-Si(p + ))、AlO x layer, an anti-reflection layer and a metal electrode, characterized in that The steps include: S01, selecting an N-type single crystal silicon substrate; The N-type single crystal silicon substrate has a resistivity of 1-20Ω·cm and a thickness of 50-300um; S02, using a trough device, performing double-sided polishing on the selected N-type single crystal silicon substrate; S03, preparation of SiO2 tunneling layer and boron-doped polysilicon layer (Poly-Si(p+)): using PECVD equipment, selecting N2O as the raw material gas for preparing SiO2, selecting CH4 / H2 / BH3 as the raw material gas for boron doping, annealing the boron-doped silicon wafer to crystallize the deposited boron-doped amorphous silicon layer, and the square resistance after doping is 100-200Ω; S04, slotting: using a silicon wafer laser slotting device to perform laser slotting on the silicon wafer obtained in step S03, and removing the BSG layer and the wrapping of the non-boron doped surface. When removing the wrapping of the non-boron doped surface, a tank cleaning device is used to perform etching using alkaline solution, and at the same time, the damaged layer at the laser slot is removed to reduce the defect recombination center at the slot, wherein the laser wavelength range is 100-1200nm, the tunneling layer thickness is 1.4nm, and the doped amorphous silicon layer thickness is 110nm; S05. For the silicon wafer processed in step S04, the boron-doped area is covered with ink, and then dried, and the ink is deposited by spraying or coating; wherein the difference between the ink width and the boron-doped area width is 0-1 mm, and the ink overflow width on the left and right sides of the boron-doped area should be consistent; S06, depositing a SiO2 tunneling layer and a phosphorus-doped amorphous silicon layer on the back of the silicon wafer after the processing in step S05: using PECVD equipment, selecting N2O as the raw material gas for preparing SiO2, selecting CH4 / H2 / PH3 as the raw material gas for phosphorus doping, annealing the phosphorus-doped silicon wafer to crystallize the deposited phosphorus-doped amorphous silicon layer, and introducing oxygen to form a PSG layer on the back of the silicon wafer; wherein the square resistance after doping is 20-200Ω; S07, removing SiO2 generated on the front and edge: using chain equipment to remove SiO2 generated on the front and edge of the silicon wafer after step S06, and using slot equipment to remove the wrapping and expansion, at the same time, using slot texturing equipment to texturing the silicon wafer after S05, so that a textured anti-reflection velvet surface is formed on the front of the silicon wafer, and the silicon wafer after texturing is cleaned with HF acid to remove the PSG layer on the back, and then dried; S08, phosphorus diffusion treatment: the front side of the silicon wafer treated in step S07 is subjected to phosphorus diffusion treatment, and oxygen is introduced to form a SiO2 protective layer on the front side of the silicon wafer; wherein the diffusion square resistance is controlled to be 100-200Ω; S09: Remove the SiO2 protective layer on the edge and back; Use chain equipment to remove the SiO2 protective layer on the edge and back of the silicon wafer after S08, and continue to use trough equipment to etch and remove the expansion in step S08. At the same time, use the solubility of alkali liquid to remove the ink printed in step S05, isolate the phosphorus and boron doped area on the back, and then use HF acid to clean the SiO2 protective layer on the front of the silicon wafer. S10: double-sided deposition of Al2O3; ALD was used to deposit Al2O3 on both sides with a thickness of 2-10nm, and TMA and H2O were selected as the reaction gases for AlOx deposition; S11: double-sided SiNx deposition; Use PECVD equipment to deposit SiNx on both sides of silicon wafers with a thickness of 20-150nm; use SiH4 and NH3 as the reaction gases for SiNx deposition; S12: Printing, sintering and testing; The silicon wafer after S11 is printed and sintered to form conductive grid lines, and then subjected to grading tests to produce TBC batteries.

2. The method for preparing a TBC battery according to claim 1, characterized in that: In step S01, the resistivity range of the N-type silicon wafer is 0.7-2.1Ω·cm, and the thickness is 130um; In step S02, the laser wavelength range is 500-600nm, In step S03, the square resistance is controlled to be 120-150Ω after boron doping; In step S05, the ink width is greater than the boron doping region width by 0.5 mm; In step S06, the square resistance after phosphorus doping is 40-60Ω; In step S08, the diffusion square resistance is controlled at 150-180Ω; In step S010, the AlOx deposition thickness is 5 nm; In step S011, the SiNx deposition thickness is 60-80 nm.

3. The method for preparing a TBC battery according to claim 1 or 2, characterized in that: In step S04, the silicon wafer laser slotting device comprises a base (1), a Y-axis moving mechanism (2) is arranged in the gap of the base (1), a placement mechanism (3) with a positioning function is fixedly arranged at the movable end of the Y-axis moving mechanism (2), a U-shaped support seat (4) is fixedly arranged on one side of the top end of the base (1), an X-axis moving mechanism (5) is fixedly arranged on the U-shaped support seat (4), a Z-axis moving mechanism (6) is fixedly arranged at the movable end of the X-axis moving mechanism (5), a mounting plate (7) is fixedly arranged at the movable end of the Z-axis moving mechanism (6), a laser slotting mechanism (8) is fixedly arranged in the middle of the mounting plate (7), and a reflection mechanism (9) is arranged at the bottom end of the laser slotting mechanism (8); The reflection mechanism (9) comprises a reciprocating rotation mechanism (91), an intermittent rotation mechanism (92) is arranged on the reciprocating rotation mechanism (91), an input end of the reciprocating rotation mechanism (91) is connected to an output end of the intermittent rotation mechanism (92), and a refraction mechanism (93) is also arranged on the reciprocating rotation mechanism (91).

4. A silicon wafer laser grooving device, which can complete the TBC battery preparation method as claimed in claim 3, characterized in that: The Y-axis moving mechanism (2), the X-axis moving mechanism (5) and the Z-axis moving mechanism (6) are all screw rod moving structures, and a rotating cavity (71) is provided at the bottom of the mounting plate (7).

5. The silicon wafer laser grooving device according to claim 4, characterized in that: The placement mechanism (3) comprises a placement seat (31) and a motor A (36). The placement seat (31) is fixedly arranged at the movable end of the Y-axis moving mechanism (2). A slide groove A (32) is opened in the middle of the placement seat (31) along the X-axis. Two sliders A (33) are slidably connected on the slide groove A (32) in a symmetrical structure. A positioning bar (34) is fixedly arranged at the top of the slider A (33). An opposing screw rod (35) is rotatably connected in the slide groove A (32). The slider A (33) is threadedly connected to the opposing screw rod (35). The motor A (36) is fixedly arranged on one side of the placement seat (31) relative to the opposing screw rod (35). The opposing screw rod (35) passes through the placement seat (31) at one end close to the motor A (36) and is fixedly connected to the output shaft of the motor A (36).

6. The silicon wafer laser grooving device according to claim 5, characterized in that: The reciprocating rotating mechanism (91) comprises a mounting seat (911) and a rotating shaft A (916); the mounting seat (911) is fixedly arranged at one end of the mounting plate (7) away from the laser slotting mechanism (8); a U-shaped seat (912) is fixedly arranged on the mounting seat (911); a connecting shaft (913) is rotatably connected to the horizontal arm of the U-shaped seat (912); a rotating disk A (914) is rotatably connected to the bottom end of the connecting shaft (913); a translation unit (915) is arranged on the rotating disk A (914); and the rotating shaft A (916) is positioned relative to the laser slotting mechanism (8). The rotating shaft A (916) is rotatably mounted on the mounting seat (911), a sliding through groove (917) is provided on the rotating shaft A (916), a round rod (918) is provided above the rotating shaft A (916), connecting seats (919) are fixedly provided at both ends of the round rod (918), the connecting seats (919) are fixedly connected to the rotating shaft A (916), a movable block (910) is sleeved on the round rod (918), a movable rod (9101) is rotatably connected to the top end of the movable block (910), and the movable rod (9101) is movably connected to the movable end of the translation unit (915).

7. The silicon wafer laser grooving device according to claim 6, characterized in that: The turntable A (914) is provided with a slide groove B (9141), and a round groove (9142) is provided on the outer edge surface of the turntable A (914) at a position relative to the slide groove B (9141). The round groove (9142) is connected to the slide groove B (9141), and a mounting cavity (9143) is provided in the middle of the round groove (9142).

8. The silicon wafer laser grooving device according to claim 7, characterized in that: The translation unit (915) comprises a slider B (9151), a screw (9153), a worm wheel (9154) and a worm (9156); the slider B (9151) is slidably arranged on the slide groove B (9141); a movable circular groove (9152) is provided on the slider B (9151); the movable rod (9101) is movably connected to the movable circular groove (9152); the screw (9153) is arranged in the circular through groove (9142); one end of the screw (9153) close to the slider B (9151) penetrates into the slider B (9151); The slide groove B (9141) is fixedly connected to the slider B (9151), the worm wheel (9154) is rotatably arranged on the installation cavity (9143), a thread groove (9155) is opened on the worm wheel (9154), the thread groove (9155) is threadedly connected to the screw rod (9153), the worm rod (9156) is rotatably arranged on the installation cavity (9143) relative to the position of the worm wheel (9154), and the top end of the worm rod (9156) passes through the turntable A (914) and is fixedly provided with an adjustment block (9157).

9. The silicon wafer laser grooving device according to claim 8, characterized in that: The intermittent rotating mechanism (92) comprises a rotating disk B (921), a rotating shaft B (924) and a motor B (928); the rotating disk B (921) is fixedly mounted on the top of the connecting shaft (913); a plurality of movable grooves (922) are provided in an annular and evenly spaced manner on the rotating disk B (921); a limiting arc groove (923) is provided at the gap position between any two adjacent movable grooves (922); the rotating shaft B (924) is rotatably mounted on the top of the U-shaped seat (912) relative to the position of the rotating disk B (921); a circular notch is fixedly mounted on the top of the rotating shaft B (924); The circular block (925) is movably matched with the limiting arc groove (923); a rotating disk C (926) is fixedly provided at the top of the circular block (925); a movable column (927) is fixedly provided at the bottom of the rotating disk C (926) at a position relative to the movable groove (922); the movable column (927) is movably matched with the movable groove (922); the motor B (928) is fixedly provided on the mounting seat (911) at a position relative to the rotating disk C (926); and the output shaft of the motor B (928) is fixedly connected to the top of the rotating disk C (926).

10. The silicon wafer laser grooving device according to claim 9, characterized in that: The refraction mechanism (93) comprises a slide bar (931), a rotating seat (934) and a motor C (937); the slide bar (931) is slidably arranged on the sliding through groove (917); the end of the slide bar (931) close to the laser slotting mechanism (8) passes through the rotating cavity (71) and is fixedly provided with a reflection block (932); the reflection block (932) is in an isosceles triangle structure; the top end of the slide bar (931) away from the laser slotting mechanism (8) is provided with a tooth groove (933); the rotating seat (934) is fixedly provided on the mounting seat (911) at a position relative to the tooth groove (933). The rotating seat (934) is rotatably connected with a rotating shaft C (935), a ball gear (936) is fixedly provided on the rotating shaft C (935), the tooth groove (933) is adapted to the ball gear (936), and the tooth groove (933) is movably connected to the ball gear (936), the motor C (937) is fixedly arranged on the mounting seat (911) relative to the rotating shaft C (935), and the end of the rotating shaft C (935) away from the ball gear (936) passes through the rotating seat (934) and the mounting seat (911) in sequence and is fixedly connected to the output shaft of the motor C (937).

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