A heterojunction battery PECVD nozzle assembly, suction cup mechanism and nozzle print improvement method

Abstract

The present invention provides a heterojunction battery PECVD nozzle assembly, a suction cup mechanism and a nozzle mark improvement method, the nozzle assembly includes a nozzle and a nozzle rod; the nozzle rod includes a connecting part, a sliding part, a rotating part and a threaded part connected to each other, a spring is sleeved on the outside of the rotating part; a threaded sleeve is sleeved on the outside of the spring; an upper fixing nut and a lower fixing nut are arranged on the outside of the threaded sleeve; the suction cup mechanism includes a plurality of N / P plate feeding suction cup assemblies respectively arranged on the N / P plate feeding robot arm and a plurality of unloading suction cup assemblies arranged on the unloading robot arm; the improvement method includes: using a suction cup mechanism with an improved structure, the carrier plate is made of carbon fiber material; the steps of the automatic feeding pull tab and the flipping mechanism are coated with wear-resistant tape; the carrier plate, the silicon wafer transmission mechanism and the suction cup are guaranteed to be level; the feeding robot arm and the unloading robot arm are each supplied with air by one CDA. The present invention reduces the nozzle mark by optimizing the suction cup to improve the efficiency and appearance of the final battery cell.

Description

Technical Field

[0001] The invention relates to the field of solar cell manufacturing, and in particular to a heterojunction cell PECVD nozzle assembly, a suction cup mechanism and a nozzle print improvement method. Background Art

[0002] In the production process of heterojunction solar cells, PECVD is undoubtedly the most critical process. The PN junction produced in this process is the basis for the photovoltaic effect. Since PECVD is a deposition-type coating, any mechanism that comes into contact with the cell during this process may form marks on the surface of the cell. Such marks include but are not limited to scratches at different positions, suction cup marks or nozzle marks formed by suction cups or nozzles performing loading and unloading actions, etc. These are closely related to the carrier recombination efficiency on the PN junction surface and the final appearance of the cell.

[0003] Due to the good coating uniformity, the CVD equipment currently used in the production of heterojunction cells is mainly plate-type PECVD. There are two mainstream production processes: one is that the N-type single crystal silicon wafers that have been surface cleaned and textured are loaded from the basket to the N-type special carrier through an automated device and then fed into the CVD equipment, and the intrinsic amorphous silicon layer and the N-type doped layer are made in sequence, and then the wafers are returned to the automated device and turned over by the flip mechanism and then loaded onto the P-type special carrier and then fed into the CVD equipment, and the intrinsic amorphous silicon layer and the P-type doped layer are made in sequence, and finally the wafers are returned to the automated device and unloaded from the P-type special carrier to the basket to complete the process; the other is not through the flip mechanism, but two CVD devices are required to respectively make the intrinsic amorphous silicon layer plus the N-type doped layer and the intrinsic amorphous silicon layer plus the P-type doped layer; no matter which method is used, two sets of loading and unloading mechanisms are required to perform the loading and unloading actions on the N-type carrier and the loading and unloading actions on the P-type carrier. The loading and unloading mechanism generally uses a four-legged suction cup, which uses a vacuum generator to form negative pressure to absorb the silicon wafer onto the suction nozzles of the four legs of the suction cup to complete the movement of the silicon wafer. Since the suction nozzle is in direct contact with the silicon wafer, it is easy to leave a suction nozzle mark on the silicon wafer. The suction nozzle mark affects the subsequent PN junction surface carrier recombination efficiency and the final appearance of the battery cell.

[0004] Based on this, the existing technology really needs to be improved. Summary of the invention

[0005] The technical problem to be solved by the present invention is to reduce the nozzle mark produced by the loading and unloading mechanism of the plate-type PECVD device.

[0006] In order to solve the above problems, the present invention provides a heterojunction battery PECVD nozzle assembly, and the technical solution adopted is as follows:

[0007] A heterojunction battery PECVD nozzle assembly comprises a nozzle and a nozzle rod, wherein the nozzle comprises a nozzle head and a nozzle sleeve connecting the nozzle head to the nozzle rod; the nozzle rod comprises a connecting portion, a sliding portion, a rotating portion and a threaded portion which are connected to each other, the cross section of the sliding portion is hexagonal, a spring is sleeved on the outside of the middle and lower sections of the rotating portion, and the threaded portion is connected to a vacuum air pipe via a connecting nut; a threaded sleeve is sleeved on the outside of the spring; an upper fixing nut and a lower fixing nut are arranged on the outside of the threaded sleeve.

[0008] In the above technical solution, the connecting portion, the sliding portion, the rotating portion and the threaded portion are integrally formed.

[0009] In the above technical solution, the inner diameter of the threaded sleeve at one end close to the sliding part is smaller than the diameter of the circle where the cross section of the sliding part is located.

[0010] In the above technical solution, a groove for accommodating a spring is formed on the inner wall of one end of the threaded sleeve close to the sliding part, and a plurality of slide grooves are formed on one end of the threaded part close to the nozzle rod, and a plurality of balls are arranged in the slide grooves.

[0011] In the above technical solution, the bottom of the sliding groove on the inner wall of the threaded sleeve is arc-shaped.

[0012] In the above technical solution, the ball contacts the rotating part of the nozzle rod.

[0013] In the above technical solution, the connecting portion of the nozzle rod is connected to the nozzle sleeve, and after assembly, the upper fixing nut and the lower fixing nut are in contact with the top and bottom surfaces of the mounting plate respectively.

[0014] In the above technical solution, the nozzle head is made of double-layer nitrile rubber or silicone; the nozzle cover and the nozzle rod are made of copper-nickel-plated material.

[0015] The present invention provides a heterojunction battery PECVD suction cup mechanism, and the technical solution adopted is as follows:

[0016] A suction cup mechanism for a heterojunction battery PECVD comprises a plurality of N-sheet feeding suction cup assemblies arranged on an N-sheet feeding robot arm, a plurality of P-sheet feeding suction cup assemblies arranged on a P-sheet feeding robot arm and a plurality of unloading suction cup assemblies arranged on an unloading robot arm; the N-sheet feeding suction cup assembly, the P-sheet feeding suction cup assembly and the unloading suction cup assembly all comprise a mounting plate, a connecting rod arranged in the middle of the top of the mounting plate and a plurality of suction nozzle assemblies, the N-sheet feeding suction cup assembly and the P-sheet feeding suction cup assembly both have two suction nozzle assemblies arranged diagonally, and the suction nozzle assemblies on the N-sheet feeding suction cup assembly and the P-sheet feeding suction cup assembly are arranged alternately; four suction nozzle assemblies are arranged on the unloading suction cup assembly and are distributed at the four corners of the mounting plate.

[0017] The present invention provides a method for improving the PECVD nozzle mark of a heterojunction battery, and the technical solution adopted is as follows:

[0018] (i) using the above-mentioned suction cup mechanism;

[0019] (ii) The carrier plate is made of carbon fiber;

[0020] (iii) The steps of the automatic feeding pull tab and the turning mechanism are coated with wear-resistant tape;

[0021] (iv) The carrier, the wafer transfer mechanism and each suction nozzle (1) are kept level;

[0022] (v) The loading robot arm and the unloading robot arm are each supplied with air by one CDA.

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides a heterojunction battery PECVD nozzle assembly, a suction cup mechanism and a nozzle mark improvement method. Aiming at the hardware conditions and film suction method of the existing plate-type PECVD, the suction cup is optimized to reduce the nozzle mark, thereby improving the efficiency and appearance of the final battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the PECVD nozzle assembly of the heterojunction battery of the present invention;

[0026] Figure 2 It is a partial cross-sectional view of the PECVD nozzle assembly of the heterojunction battery of the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the N-plate material suction cup assembly in the heterojunction battery PECVD suction cup mechanism of the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of the P-plate material suction cup assembly in the PECVD suction cup mechanism of the heterojunction battery of the present invention;

[0029] Figure 5 A schematic structural diagram of the unloading suction cup assembly in the heterojunction battery PECVD suction cup mechanism of the present invention.

[0030] in:

[0031] 1 nozzle

[0032] 11 nozzle head 12 nozzle cover

[0033] 2 nozzle rod

[0034] 21 sliding part 22 connecting part

[0035] 23 threaded sleeve 24 spring

[0036] 25 connecting nut 26 ball

[0037] 3 Upper fixing nut

[0038] 4 Lower fixing nut

[0039] 01 Nozzle assembly

[0040] 02Mounting plate

[0041] 03Connecting rod. DETAILED DESCRIPTION

[0042] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0043] Example 1

[0044] like Figure 1 , 2 As shown, the present invention provides a heterojunction battery PECVD nozzle assembly, comprising a nozzle 1 and a nozzle rod 2, wherein the nozzle 1 comprises a nozzle head 11 and a nozzle sleeve 12 connecting the nozzle head 11 with the nozzle rod 2;

[0045] The suction nozzle rod 2 includes a connecting part, a sliding part 21, a rotating part 22 and a threaded part that are interconnected. The cross-section of the sliding part 21 is hexagonal. A spring 24 is sleeved on the outside of the middle and lower sections of the rotating part 22. The threaded part is connected to the vacuum air pipe through a connecting nut 25. A threaded sleeve 23 is sleeved on the outside of the spring 24. An upper fixing nut 3 and a lower fixing nut 4 are arranged on the outside of the threaded sleeve 23.

[0046] The connecting portion, the sliding portion 21 , the rotating portion 22 and the threaded portion are integrally formed.

[0047] The inner diameter of the threaded sleeve 23 at one end close to the sliding portion 21 is smaller than the diameter of the circle where the cross section of the sliding portion 21 is located.

[0048] The inner wall of the threaded sleeve 23 at one end close to the sliding portion 21 is formed with a groove for accommodating the spring 24 , and the end close to the threaded portion of the nozzle rod 2 is formed with a plurality of slide grooves, in which a plurality of balls 26 are arranged.

[0049] The bottom of the sliding groove on the inner wall of the threaded sleeve 23 is arc-shaped.

[0050] The ball 26 is in contact with the rotating portion 22 of the nozzle rod 2 .

[0051] The connection portion of the nozzle rod 2 is connected to the nozzle sleeve 12 . After assembly, the upper fixing nut 3 and the lower fixing nut 4 are in contact with the top and bottom surfaces of the mounting plate 02 , respectively.

[0052] The nozzle head 11 is made of double-layer nitrile rubber or silicone; the nozzle cover 12 and the nozzle rod 2 are made of copper-nickel-plated material.

[0053] In this embodiment, the cross section of the sliding portion 21 is hexagonal.

[0054] When the suction cup is close to the silicon wafer, due to the pulling force and deformation of the vacuum air pipe above the suction cup rod, the suction nozzle head 11 will cause slight rotation when contacting the silicon wafer. The suction nozzle head 11 is round, so as long as there is a small rotation, the circular suction nozzle mark will deepen. Therefore, in this embodiment, the cross-section of the sliding part 21 of the suction cup rod is set to a hexagon to prevent the suction cup rod from rotating when sucking the wafer, thereby reducing the possibility of suction nozzle marks.

[0055] In order to reduce the possibility of nozzle marks, a non-rotatable suction cup rod can be selected. However, after long-term operation of the equipment, the high temperature and dry environment inside the equipment, and the lateral pulling force of the vacuum air pipe above the suction cup rod, the sliding part of the suction cup rod will be partially worn at the top; this wear will cause a certain suction cup rod to get stuck when sucking the wafer, thereby causing leakage or hidden cracks of the silicon wafer; on the one hand, it causes the fragmentation rate to rise, and on the other hand, silicon wafer debris remains on the carrier plate or the loading pull tab step and the flip step. When normal silicon wafers pass through later, it will cause batch scratches, which is also a great loss to the yield. Therefore, it is still necessary to select a suction cup rod with a smooth sliding part. In this embodiment, by arranging a slide groove and a ball inside the threaded sleeve, the sliding friction between the sliding part of the suction cup rod and the inside of the threaded sleeve is changed from the original sliding friction to rolling friction, which greatly reduces the wear of the suction cup rod, increases the service life of the suction cup rod, and at the same time, improves the final yield.

[0056] Example 2

[0057] Based on Example 1, Figures 3 to 5 As shown, a suction cup mechanism for a heterojunction battery PECVD includes a plurality of N-sheet feeding suction cup assemblies arranged on an N-sheet feeding robot arm, a plurality of P-sheet feeding suction cup assemblies arranged on a P-sheet feeding robot arm, and a plurality of unloading suction cup assemblies arranged on an unloading robot arm; the N-sheet feeding suction cup assembly, the P-sheet feeding suction cup assembly, and the unloading suction cup assembly all include a mounting plate 02, a connecting rod 03 arranged in the middle of the top of the mounting plate 02, and a plurality of suction nozzle assemblies 01, characterized in that the N-sheet feeding suction cup assembly and the P-sheet feeding suction cup assembly both have two suction nozzle assemblies 01 arranged diagonally, and the suction nozzle assemblies 01 on the N-sheet feeding suction cup assembly and the P-sheet feeding suction cup assembly are staggered; four suction nozzle assemblies 01 are arranged on the unloading suction cup assembly, and are distributed at the four corners of the mounting plate 02.

[0058] The structure of the nozzle assembly 01 is as described in Example 1.

[0059] For the vacuum suction tubes where the suction nozzle assembly 01 is not provided, they should be bundled or removed to prevent silicon wafers from being sucked away due to vacuum leakage.

[0060] Since the unloading robot arm sucks silicon wafers from the carrier, and the temperature of the carrier is relatively high, the flat surface of the silicon wafer is attached to the bottom surface of the carrier groove, which is prone to hidden cracks and leakage caused by the shaking of the silicon wafer when it is lifted up. Therefore, the number of nozzle assemblies 01 of the unloading suction cup assembly arranged on the unloading robot arm is set to four; and the N-plate loading suction cup assembly and the P-plate loading suction cup assembly are both provided with two nozzle assemblies diagonally; the two diagonally arranged nozzle assemblies ensure the stability of the loading and sucking of the wafer, and ensure that the contact area between the nozzle and the silicon wafer is as small as possible, thereby reducing the nozzle mark.

[0061] Example 3

[0062] Based on Examples 1 and 2, a method for improving the PECVD nozzle print of a heterojunction battery comprises:

[0063] (i) using the suction cup mechanism described in Example 2;

[0064] (ii) The carrier plate is made of carbon fiber;

[0065] The carriers commonly used in production are graphite, carbon fiber or other conductive materials mixed with graphite. This improvement method uses a carbon fiber carrier, and the number of silicon wafers on the carrier is 10*8, which just matches the ten suction cups on a robotic arm.

[0066] (iii) The steps of the automatic feeding pull tab and the turning mechanism are coated with wear-resistant tape;

[0067] The steps of the automatic feeding pull tab and the flipping mechanism need to be replaced with new wear-resistant tape to prevent the warping of the tape from causing scratches and affecting the final efficiency test;

[0068] (iv) Ensure the level of the carrier, wafer transfer mechanism and each nozzle;

[0069] The weight of the nozzle mark is not only related to the nozzle, but also to the descent depth of the robot arm, the speed of ascent and descent, the horizontality of the carrier and silicon wafer transmission, and the horizontality of each nozzle on the suction cup. The improvement method of the present invention also includes ensuring that the carrier and silicon wafer transmission mechanism and each nozzle on each suction cup have sufficient horizontality.

[0070] The level of the carrier is adjusted by adjusting the height of the support blocks at each part below the carrier and the clamping degree of the carrier clamp.

[0071] The level of the suction nozzle can be adjusted through a horizontal reference object. Specifically, first slowly lower the robot arm to the surface of the horizontal reference object. When the suction nozzle and the reference surface are in a state of almost touching but not touching, stop descending. At this time, lower all the suction cup rods to the state where the suction nozzle is in contact with the reference surface, that is, the suction nozzle is level.

[0072] At the same time, appropriately raise the height of the two loading robotic arms (N plate and P plate) when placing the film on the carrier plate, which will reduce the downward pressure when placing the film and reduce the nozzle mark;

[0073] (v) The loading robot arm and the unloading robot arm are each supplied with air by one CDA.

[0074] Specifically: the N-plate loading and unloading robot arm and the P-plate loading and unloading robot arm are named Trf1, Trf2, Trf3, and Trf4 respectively, and the 10 suction cups on each robot arm (starting from the closest to the CVD equipment) are named Picker1 to Picker10 respectively. Each robot arm of Trf1, Trf2, Trf3, and Trf4 is vacuumed by two vacuum generators, and each vacuum generator controls the vacuum of five Pickers. Since the vacuum pressure used by the loading arm can be less than the vacuum pressure used by the unloading arm, the CDA of the original TrayAPicker and the CDA of the TrayC Picker are transformed into Trf1 and Trf3 supplied by one CDA, and Trf2 and Trf4 by another CDA. The two CDAs have two pressure regulating valves to realize pressure regulation. Finally, the vacuum pressure of Trf1 and Trf3 is -20, the vacuum pressure of Trf2 and Trf4 is -35, and the vacuum of the flip Flipeer is controlled by the third CDA, and the pressure is -20.

[0075] The principle of the nozzle mark improvement method of the present invention is:

[0076] In order to reduce the nozzle mark, the present invention reduces the contact area between the nozzle and the silicon wafer and reduces the relative movement between the nozzle and the silicon wafer under the premise of ensuring the horizontality of the carrier plate and the nozzle.

[0077] First, with regard to reducing the contact area between the suction nozzle and the silicon wafer: since the two sets of loading mechanisms only suck up the silicon wafers from the silicon wafer transmission mechanism, the silicon wafers can be sucked up with smaller suction force and fewer suction nozzles, so the number of suction nozzle assemblies of the N-plate loading suction cup assembly and the P-plate loading suction cup assembly is changed from four to two, reducing the contact area between the suction nozzle and the silicon wafer; and both sets of unloading mechanisms need to suck up the silicon wafers from the firmly bonded high-temperature carrier plate, so the unloading suction cup assembly needs to have a slight downward pressure and use a larger suction force to suck up the silicon wafers, so the unloading suction cup assembly uses four suction nozzle assemblies.

[0078] Secondly, with regard to reducing the relative movement between the suction nozzle and the silicon wafer: the vacuum suction cup rod adopts an anti-rotation suction cup rod with smooth up and down movement to reduce the rotational friction between the suction cup and the silicon wafer, especially the suction cup assembly of the unloading suction cup, to reduce the suction nozzle mark.

[0079] The effect of the nozzle mark improvement method of the present invention is further verified by experiments. After the silicon wafer body is cleaned and textured, the CVD stage is carried out according to normal mass production process conditions. After all processes are completed, PL detection is required to determine the number and obviousness of the nozzle marks, and the severity of the nozzle marks is determined in combination with the clarity of the nozzle marks in the EL test picture after the screen. The CVD coating process is a double-layer coating process, with I+N Layer on the front and I+P Layer on the back, because the PL test equipment requires double-sided coating to have a clear PL image. After the CVD coating of the silicon wafer, the normal PVD+screen process needs to be completed to obtain the final efficiency data and the final EL image:

[0080] First, as for the reduction of the number of nozzle marks, if all four robotic arms are equipped with four nozzle assemblies, and there is a slight deviation in the position of the nozzles on the suction cups of each robotic arm, each silicon wafer may have 16 nozzle marks. However, by adopting the method of the present invention, by reducing the nozzles, the maximum number of nozzle marks that may be generated is 12. In addition, with the support of the carrier board and the leveling of the suction cup, the frequency of nozzle marks can be greatly reduced. The nozzle marks that occur are also slightly visible in PL and invisible in EL, which improves the final efficiency and yield of the battery cell. The test results are shown in the following table;

[0081]

[0082] According to the experimental data, the Eta and Voc of the battery cell and the final stable production yield have been improved to varying degrees before and after the transformation. Before the transformation, the average Eta was 24.45, the average Voc was 0.7465, and the average yield was 93%; after the transformation, the average Eta was 24.50, the average Voc was 0.7470, and the average yield was 95%; by comparison, Eta has increased by 0.05, Voc has increased by 0.0005, and the yield has increased by 2%; therefore, by reducing the contact area between the nozzle and the silicon wafer, and reducing the rotational friction between the nozzle and the silicon wafer, the process data can be improved while improving the nozzle print, achieving the purpose of improvement.

[0083] The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The patent protection scope of the present invention should be defined by the claims.

Claims

1. A heterojunction battery PECVD nozzle assembly, comprising a nozzle (1) and a nozzle rod (2), characterized in that: The suction nozzle (1) comprises a suction nozzle head (11) and a suction nozzle sleeve (12) connecting the suction nozzle head (11) to the suction nozzle rod (2); The nozzle rod (2) comprises a connecting portion, a sliding portion (21), a rotating portion (22) and a threaded portion which are connected to each other; the sliding portion (21) has a hexagonal cross section; a spring (24) is sleeved on the outside of the middle and lower sections of the rotating portion (22); the threaded portion is connected to a vacuum air pipe via a connecting nut (25); a threaded sleeve (23) is sleeved on the outside of the spring (24); an upper fixing nut (3) and a lower fixing nut (4) are arranged on the outside of the threaded sleeve (23); The connecting portion, the sliding portion (21), the rotating portion (22) and the threaded portion are integrally formed; The inner diameter of the end of the threaded sleeve (23) close to the sliding portion (21) is smaller than the diameter of the circle where the cross section of the sliding portion (21) is located; The inner wall of the threaded sleeve (23) at one end close to the sliding portion (21) is formed with a groove for accommodating the spring (24), and the inner wall of the threaded sleeve (23) at one end close to the threaded portion of the nozzle rod (2) is formed with a plurality of slide grooves, in which a plurality of balls (26) are arranged.

2. The heterojunction battery PECVD nozzle assembly according to claim 1, characterized in that: The bottom of the sliding groove on the inner wall of the threaded sleeve (23) is arc-shaped.

3. The heterojunction battery PECVD nozzle assembly according to claim 1, characterized in that: The ball (26) contacts the rotating portion (22) of the nozzle rod (2).

4. The heterojunction battery PECVD nozzle assembly according to claim 1, characterized in that: The connection portion of the suction nozzle rod (2) is connected to the suction nozzle sleeve (12), and after assembly, the upper fixing nut (3) and the lower fixing nut (4) are in contact with the top and bottom surfaces of the mounting plate (02) respectively.

5. The heterojunction battery PECVD nozzle assembly according to claim 1, characterized in that: The nozzle head (11) is made of double-layer nitrile rubber or silicone; the nozzle cover (12) and the nozzle rod (2) are made of nickel-plated copper.

6. The suction cup mechanism of the heterojunction battery PECVD suction cup assembly according to claim 1 comprises a plurality of N-sheet feeding suction cup assemblies arranged on an N-sheet feeding robot arm, a plurality of P-sheet feeding suction cup assemblies arranged on a P-sheet feeding robot arm, and a plurality of unloading suction cup assemblies arranged on an unloading robot arm; the N-sheet feeding suction cup assembly, the P-sheet feeding suction cup assembly, and the unloading suction cup assembly all comprise a mounting plate (02), a connecting rod (03) arranged in the middle of the top of the mounting plate (02), and a plurality of suction cup assemblies (01), characterized in that: The N-plate material feeding suction cup assembly and the P-plate material feeding suction cup assembly are both provided with two suction nozzle assemblies (01) arranged diagonally, and the suction nozzle assemblies (01) on the N-plate material feeding suction cup assembly and the P-plate material feeding suction cup assembly are arranged alternately; four suction nozzle assemblies (01) are arranged on the unloading suction cup assembly and are distributed at the four corners of the mounting plate (02).

7. A method for improving the nozzle mark of the suction cup mechanism of the heterojunction battery PECVD nozzle assembly according to claim 6, characterized in that: include (i) using the suction cup mechanism as claimed in claim 6; (ii) The carrier plate is made of carbon fiber; (iii) The steps of the automatic feeding pull tab and the turning mechanism are coated with wear-resistant tape; (iv) The carrier, the wafer transfer mechanism and each suction nozzle (1) are kept level; (v) The loading robot arm and the unloading robot arm are each supplied with air by one CDA.

Images