Non-contact metallization system

Abstract

The application discloses a non-contact metallization system, which comprises a glass substrate, a paste filling mechanism, a moving mechanism and a light emitter. The glass substrate has a front surface and a back surface arranged oppositely. The front surface is provided with a groove, the width of the groove is not less than 3 um, and the depth of the groove is not less than 5 um. The paste filling mechanism is used for filling paste in the groove of the glass substrate. The moving mechanism is used for keeping the front surface of the glass substrate and a receiving substrate in a certain interval. The light emitter is used for emitting light to the back surface of the glass substrate, so that the paste in the groove is transferred to the receiving substrate. The non-contact metallization system has the advantages of high precision and low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic cell preparation, in particular to a non-contact metallization system. BACKGROUND

[0002] Global energy transformation is the trend of the times, and the photovoltaic market size will accelerate expansion, and the production capacity will further expand. Cell metallization is a necessary process step for photovoltaic crystalline silicon cells. The biggest technical change in the photovoltaic industry is the transition from P-type to N-type cells. N-type cells must consider ways to reduce the cost of metallization for large-scale industrialization. Silver paste accounts for the largest proportion of non-silicon costs, about 33%, and the cost of silver paste accounts for about 8% of the overall cost of the cell. Therefore, reducing silver paste consumption has become a problem that the industry needs to solve.

[0003] Metallization technology can be roughly divided into contact and non-contact. Among them, contact is mainly applied to screen printing technology. Non-contact is mainly applied to laser transfer technology. Due to the limitations of paste, screen and printing methods, traditional screen printing cannot meet the demand of reducing silver paste consumption in photovoltaics. In addition, traditional screen printing technology needs to contact the silicon wafer when printing, but with the development trend of thinning, this contact process is prone to cause problems such as broken pieces, scratches, contamination, and hidden cracks in the silicon wafer, affecting product yield.

[0004] Based on the defects of screen printing technology, laser transfer technology has become the main technical means to replace traditional screen printing due to its many advantages such as fine grid lines, high aspect ratio, low single consumption, and non-contact.

[0005] Current laser transfer technology fills the paste into the groove on the specific flexible film by setting the groove of the required paste shape, and scans the groove pattern from the opposite side of the groove with a laser beam to transfer the paste from the groove to the surface of the cell to form grid lines. By setting the groove pattern and shape on the flexible film, laser transfer technology can break through the line width limit of traditional screen printing and achieve a line width below 25um, thereby achieving a better aspect ratio, improving cell conversion efficiency, and reducing paste consumption. Laser transfer grid line consistency and uniformity are superior to traditional screen printing, and non-contact printing method is more suitable for thinning. Moreover, laser transfer technology has no restrictions on cell structure and has wide application prospects in PERC, Topcon, HJT, and IBC cells.

[0006] In the laser transfer printing technology, a flexible film is used as a carrier substrate of the paste, which can realize the transfer printing of the paste, but the flexible film has high material cost and high use cost (mainly manifested as the need to ensure the high consistency of the tension degree of the flexible film in the transfer printing process), and low repeated utilization rate, which leads to high application cost of the laser transfer printing scheme using the flexible film; at the same time, since the flexible film is a flexible substrate, it is difficult to ensure the high consistency of the grid line width in the transfer printing process. Moreover, the flexible film will be material fatigue after long-term use, which will reduce the process precision. SUMMARY

[0007] The main purpose of the present application is to provide a non-contact metallization system, which aims to solve the technical problems of high application cost of the laser transfer printing scheme using the flexible film and process precision reduction caused by long-term repeated use of the flexible film.

[0008] To achieve the above purpose, the non-contact metallization system provided by the present application comprises:

[0009] a glass substrate having a front surface and a back surface arranged oppositely, the front surface being provided with a groove, the width of the groove being not less than 3 um, and the depth of the groove being not less than 5 um;

[0010] a paste filling mechanism for filling paste in the groove of the glass substrate;

[0011] a moving mechanism for keeping the front surface of the glass substrate and the receiving substrate at a certain interval relative to each other; and

[0012] a light emitter for emitting light towards the back surface of the glass substrate to transfer the paste in the groove to the receiving substrate.

[0013] In an embodiment, the paste filling mechanism comprises a doctor blade, which is used to move along the front surface of the glass substrate at least once to fill the paste in the groove and scrape off the paste on the surface of the glass substrate.

[0014] In an embodiment, the moving direction of the doctor blade is substantially perpendicular or substantially parallel to the extension direction of the groove.

[0015] In an embodiment, the moving mechanism comprises a turnover mechanism and a conveying mechanism,

[0016] the turnover mechanism is used to turn over at least one of the glass substrate and the receiving substrate to make the front surface of the glass substrate face the direction where the receiving substrate is located;

[0017] The conveying mechanism is used to convey the flipped glass substrate and the receiving substrate to a designated transfer station, and to keep the glass substrate and the receiving substrate in relative position with a certain interval.

[0018] In an embodiment, the conveying mechanism corrects the position of the glass substrate and the receiving substrate when conveying the receiving substrate and the conveying substrate to the transfer station.

[0019] In an embodiment, the conveying mechanism comprises a CCD image capturing device and a conveying device, the CCD image capturing device is used to capture the photo of the glass substrate and the receiving substrate, and to calculate the displacement compensation of the glass substrate and the receiving substrate according to the photo, and the conveying device conveys the glass substrate and the receiving substrate to the transfer station based on the displacement compensation.

[0020] In an embodiment, the conveying device comprises a first conveying component, which stepwise or continuously circulates to convey the glass substrate between the slurry filling mechanism, the flipping mechanism, the CCD image capturing device and the transfer station.

[0021] In an embodiment, the conveying device comprises a second conveying component, which stepwise or continuously conveys the receiving substrate to the transfer station, and conveys the receiving substrate after transfer to the transfer station.

[0022] In an embodiment, the first conveying component comprises any one of a rotary conveying component and a linear conveying component; and / or

[0023] The second conveying component comprises any one of a rotary conveying component and a linear conveying component.

[0024] In an embodiment, the light emitter is any one of a laser emitter and a non-laser emitter.

[0025] Overall, the present application has the following advantages compared with the prior art:

[0026] (1) Non-contact: can be applied to non-contact photovoltaic cell preparation equipment and process, so that there is no need to contact the silicon wafer during the transfer process, thereby better protecting the product, reducing the probability of product breakage, scratches, pollution, hidden cracks, etc., thereby facilitating the development of silicon wafer thinning;

[0027] (2) Higher precision: not only can realize the minimum 3um line width, and because the glass substrate is a rigid material, it can ensure the flatness of the groove edge, so that the edge of the grid line obtained by transfer is neat, which is conducive to realizing a better aspect ratio, improving the battery conversion efficiency, and reducing the slurry consumption;

[0028] (3) Good stability: the glass carrier plate has high surface flatness, high light transmittance, strong durability and high reusability;

[0029] (4) Low cost: after using the glass substrate, there is no need to customize the steel mesh template, and the glass substrate is easy to clean and has high reusability, thereby reducing consumables and cost. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0031] Figure 1 Structure diagram of a glass substrate in an embodiment of the non-contact metallization system of the present application;

[0032] Figure 2 Structure diagram in an embodiment of the non-contact metallization system of the present application;

[0033] Figure 3 Structure diagram of a doctor blade moving in one direction in the non-contact metallization system of the present application;

[0034] Figure 4 Structure diagram of a doctor blade moving in another direction in the non-contact metallization system of the present application;

[0035] Figure 5 Structure diagram of another embodiment of the non-contact metallization system of the present application;

[0036] Figure 6 Structure diagram of another embodiment of the non-contact metallization system of the present application; Figure 5 Structure diagram of another embodiment of the non-contact metallization system of the present application;

[0037] Figure 7 Structure diagram of another embodiment of the non-contact metallization system of the present application;

[0038] Figure 8 Structure diagram of another embodiment of the non-contact metallization system of the present application; Figure 7 Structure diagram of another embodiment of the non-contact metallization system of the present application;

[0039] Figure 9 Structure diagram of another embodiment of the non-contact metallization system of the present application;

[0040] Figure 10 Structure diagram of another embodiment of the non-contact metallization system of the present application; Figure 9 Structure diagram of another embodiment of the non-contact metallization system of the present application;

[0041] Figure 11 Fig. 9 is a schematic view of another glass substrate structure in the non-contact metallization system of the present application.

[0042] BRIEF DESCRIPTION OF DRAWINGS

[0043] 10, glass substrate; 10a, front surface; 10b, back surface; 11, trench; 12, fine grid trench; 13, coarse grid trench; 20, receiving substrate; 30, light emitter; 40, paste filling mechanism; 41, doctor blade; 43, paste filling station; 50, turning mechanism; 51, turning station; 60, transfer station; 80, finished product; 90, conveying mechanism; 91, CCD imaging device; 911, imaging station; 92, conveying device; 921, first conveying component; 922, second conveying component; 921a, loading station; 921b, unloading station

[0044] The objectives, features and advantages of the present application will be further illustrated in conjunction with the embodiments, with reference to the accompanying drawings. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0046] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0047] In addition, if the embodiments of the present application involve descriptions of "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" appearing throughout the text means that the three parallel schemes are included, taking "A and / or B" as an example, including A scheme, or B scheme, or A and B schemes are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection claimed by the present application.

[0048] The present application provides a non-contact metallization system, which is applied to the preparation of photovoltaic cells, and in particular, is used to make grid lines on silicon wafers of photovoltaic cells. Alternatively, the laser transfer method for realizing metallization is a typical non-contact metallization system.

[0049] In some embodiments, as shown in Figures 1 to 5 The metallization system of the present application includes a glass substrate 10, a paste filling mechanism 40, a moving mechanism, and a light emitter 30.

[0050] Specifically, the glass substrate 10 has a front surface 10a and a back surface 10b arranged oppositely, and the front surface 10a is provided with a groove 11, the width of which is not less than 3um, and the depth of the groove 11 is not less than 5um.

[0051] Specifically, the glass substrate 10 is transparent to light, and light can propagate from the front surface 10a of the glass substrate 10 to the back surface 10b of the glass substrate 10, and vice versa. The transparent glass substrate 10 can transmit energy from the laser irradiated from the back surface 10b of the glass substrate 10 to the paste in the groove 11, so as to make the paste separate from the groove 11.

[0052] In some embodiments, the light transmittance of the glass substrate 10 is not less than 80%. In this way, not only is it beneficial to align the glass substrate 10 with the silicon wafer, but also it can reduce the energy loss of the laser, so as to reduce the power consumption requirement of the laser.

[0053] For example, the light transmittance of the glass substrate 10 can be set to 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, etc.

[0054] In actual application, according to the product demand / design requirement of actual solar cells (photovoltaic cells), the groove 11 conforming to the expectation is manufactured on the front surface 10a of the glass substrate 10 in a self-adaptive manner. The expectation of the groove 11 includes but is not limited to the specific size specification of the groove 11, the number of the groove 11, the shape of the groove 11, and the pattern formed by the groove 11. Among them, the pattern formed by the groove 11 is determined according to the pattern of the grid lines on the silicon wafer to be produced.

[0055] Due to the inevitable production errors in actual production, the width of the groove 11 on the glass substrate 10 is actually consistent with the expected width of the grid lines on the photovoltaic cell, and the depth of the groove 11 is actually consistent with the expected height of the grid lines on the photovoltaic cell.

[0056] For example, the width of the trench 11 can be set to 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um, 11um, 12um, 13mm, 14um, 15um, 16um, 17um, 18um, 19um, 20um, 21um, 22um, 23mm, 24um, 25um, 26um, 27um, 28um, 29um, 30um, 31um, 32um, 33mm, 34um, 35um, 36um, 37um, 38um, 39um, 40um, 41um, 42um, 43mm, 44um, 45um, 46um, 47um, 48um, 49um, 50um, 51um, 52um, 53mm, 54um, 55um, 56um, 57um, 58um, 59um, 60um, 61um, 62um, 63mm, 64um, 65um, 66um, 67um, 68um, 69um, 70um, 71um, 72um, 73mm, 74um, 75um, 76um, 77um, 78um, 79um, 80um, 81um, 82um, 83mm, 84um, 85um, 86um, 87um, 88um, 89um, 90um, 91um, 92um, 93mm, 94um, 95um, 96um, 97um, 98um, 99um, 100um, 110um, 120um, 130um, 140um, 150um, 160um, 170um, 180um, 190um, 200um, 210um, 220um, 230um, 240um, 250um, 260um, 270um, 280um, 290um, 300um, 310um, 320um, 330um, 340um, 350um, 360um, 370um, 380um, 390um, 400um, 410um, 420um, 430um, 440um, 450um, 460um, 470um, 480um, 490um, 500um, etc.

[0057] For example, the depth of the trench 11 can be set to 5um, 6um, 7um, 8um, 9um, 10um, 11um, 12um, 13mm, 14um, 15um, 16um, 17um, 18um, 19um, 20um, 21um, 22um, 23mm, 24um, 25um, 26um, 27um, 28um, 29um, 30um, 31um, 32um, 33mm, 34um, 35um, 36um, 37um, 38um, 39um, 40um, 41um, 42um, 43mm, 44um, 45um, 46um, 47um, 48um, 49um, 50um, 51um, 52um, 53mm, 54um, 55um, 56um, 57um, 58um, 59um, 60um, 61um, 62um, 63mm, 64um, 65um, 66um, 67um, 68um, 69um, 70um, 71um, 72um, 73mm, 74um, 75um, 76um, 77um, 78um, 79um, 80um, 81um, 82um, 83mm, 84um, 85um, 86um, 87um, 88um, 89um, 90um, 91um, 92um, 93mm, 94um, 95um, 96um, 97um, 98um, 99um, 100um, 110um, 120um, 130um, 140um, 150um, 160um, 170um, 180um, 190um, 200um, etc.

[0058] In some embodiments, the width-to-depth ratio of the trench 11 is between 1:1 and 20:1. For example, when the width of the trench 11 is between 5um and 100um, the depth of the trench 11 can be set to be between 5um and 100um. In this way, the cost of manufacturing the glass substrate 10 and the density of the trench 11 on the glass substrate 10 can be balanced, and thus a photovoltaic cell with better performance can be obtained at a lower cost.

[0059] In some embodiments, the opening can be made on the front surface 10a of the glass substrate 10 by laser to obtain the desired trench 11. Specifically, the laser beam can be controlled to move along the desired trench 11 on the front surface 10a of the glass substrate 10, and thus the desired trench 11 can be made on the front surface 10a of the glass substrate 10 by the energy of the laser.

[0060] In some embodiments, the desired trenches 11 can be etched on the front surface 10a of the glass substrate 10 by etching. Specifically, the trench 11 pattern can be pre-fabricated on the front surface 10a of the glass substrate 10 according to the product requirement of the photovoltaic cell, and then the front surface 10a of the glass substrate 10 can be etched by chemical etching or photo-etching to obtain the desired trenches 11.

[0061] It can be understood that due to the better rigidity of the glass substrate 10, compared with the flexible film, the accuracy of the trenches 11 can be better ensured, and the deformation can be avoided, and the manufacturing accuracy can be ensured in long-term use.

[0062] Further, the slurry filling mechanism is used to fill the slurry in the trenches of the glass substrate.

[0063] Alternatively, the slurry filling mechanism 40 comprises a scraper 41, which is moved at least once along the front surface 10a of the glass substrate 10 to fill the slurry in the trenches 11 and scrape the slurry on the surface of the glass substrate 10.

[0064] Specifically, when the slurry is filled in the trenches 11 of the glass substrate 10, the slurry can be added on the surface of the glass substrate 10 first, and then the scraper 41 is controlled to move along the front surface 10a of the glass substrate 10 to push the slurry into the trenches 11, and at the same time, the scraper 41 can also scrape the excess slurry on the surface of the glass substrate 10 when moving, so as to avoid the residual slurry in the non-trench 11. Further, based on the filling effect (how much the slurry is filled) of the slurry in the trenches 11 and the scraping effect of the slurry on the surface of the glass substrate 10, the number of times of moving the scraper 41 on the surface of the glass substrate 10 can be adjusted adaptively. For example, when the filling effect of the slurry in the trenches 11 is good and the scraping of the slurry on the surface of the glass substrate 11 is sufficient, the scraper 41 can be controlled to move on the surface of the glass substrate 10 once; when the filling effect of the slurry in the trenches 11 is poor and the scraping of the slurry on the surface of the glass substrate 11 is insufficient, the scraper 41 can be controlled to move on the surface of the glass substrate 10 twice or more. It should be understood that when the scraper 41 moves twice or more, the scraper 41 can be controlled to move at least twice in the same direction, or the scraper 41 can be controlled to move back and forth on the two sides of the glass substrate 10, or the scraper 41 can be controlled to move in different directions each time.

[0065] It is worth mentioning that during the process of the scraper 41, the slurry filling head and other mechanisms can be controlled to automatically supplement the slurry on the front surface 10a of the glass substrate 10, so as to ensure that enough slurry is filled into the trenches 11.

[0066] It is also worth mentioning that, when filling the slurry, the slurry can be filled in all the trenches 11 of the glass substrate 10 at one time, or only part of the trenches 11 can be filled with the slurry. According to the number and position of the filled trenches 11, the size, moving times and moving path of the scraper 41 are also adaptively adjusted.

[0067] In some embodiments, the trenches 11 are arranged along one edge of the glass substrate 10 on the front surface 10a of the glass substrate 10. Based on the above arrangement of the trenches 11, the scraper 41 can be controlled to move in a direction parallel to the trenches 11 when the slurry is scraped. Alternatively, the scraper 41 can be controlled to move in a direction perpendicular to the trenches 11. The above two moving ways of the scraper 41 can more easily cover the entire front surface 10a of the glass substrate 10, thereby more efficiently removing the excess slurry. It should be understood that when the scraper 41 needs to move along the surface of the glass substrate 10 at least twice, the scraper 41 can be controlled to move in a direction parallel to the trenches 11 when moving for the first time, and the scraper 41 can be controlled to move in a direction perpendicular to the trenches 11 when moving for the second time. Of course, the opposite is also possible.

[0068] It is also worth supplementing that the angle between the moving direction of the scraper 41 and the extension direction of the trenches 11 is 0°-10°, which can be considered as that the moving direction of the scraper 41 is parallel to the trenches 11. Correspondingly, the angle between the moving direction of the scraper 41 and the extension direction of the trenches 11 is 80°-90°, which can be considered as that the moving direction of the scraper 41 is perpendicular to the trenches 11.

[0069] Of course, the design of the present application is not limited to this, and in other embodiments, the scraper 41 can also be controlled to move in other directions.

[0070] It can be understood that, by using the trenches 11 to fill the slurry, not only the filling of the slurry is simple and convenient, but also the precision is higher, so as to obtain a higher precision grid line. In addition, when the slurry is filled in the trenches 11, it is easier to obtain a relatively smaller width, so as to obtain a higher performance photovoltaic cell.

[0071] In some embodiments, the slurry can be any conductive slurry material known in the prior art. For example, silver-based slurry, such as low-temperature silver paste, high-temperature silver paste, etc. Among them, the division of low-temperature silver paste and high-temperature silver paste is different according to the actual production specification, and the division standard is also different. For example, we can define the silver paste with a temperature lower than 200℃-350℃ as low-temperature silver paste, and the silver paste with a temperature higher than 200℃-350℃ as high-temperature silver paste. Generally, the slurry used for solar applications is a combination of four different materials: metal powder, glass powder and modifier, volatile solvent and non-volatile polymer or resin.

[0072] Further, the moving mechanism is used to keep the front surface 10a of the glass substrate 10 and the receiving substrate 20 in a certain interval.

[0073] Alternatively, the interval between the glass substrate 10 and the receiving substrate 20 is not less than 30 um and not more than 200 um. Specifically, keeping the interval between the glass substrate 10 and the silicon wafer not less than 200 um can keep the glass substrate 10 and the silicon wafer in a non-contact state, thereby avoiding the problems of hidden cracks, broken pieces, pollution, scratches and the like existing in the extrusion printing, so as to realize the thin design of the silicon wafer. And the interval between the glass substrate 10 and the silicon wafer is not more than 200 um, which can ensure the precision of laser transfer and realize the accurate transfer of the paste.

[0074] For example, the interval can be set to 30 um, 31 um, 32 um, 33 mm, 34 um, 35 um, 36 um, 37 um, 38 um, 39 um, 40 um, 41 um, 42 um, 43 mm, 44 um, 45 um, 46 um, 47 um, 48 um, 49 um, 50 um, 51 um, 52 um, 53 mm, 54 um, 55 um, 56 um, 57 um, 58 um, 59 um, 60 um, 61 um, 62 um, 63 mm, 64 um, 65 um, 66 um, 67 um, 68 um, 69 um, 70 um, 71 um, 72 um, 73 mm, 74 um, 75 um, 76 um, 77 um, 78 um, 79 um, 80 um, 81 um, 82 um, 83 mm, 84 um, 85 um, 86 um, 87 um, 88 um, 89 um, 90 um, 91 um, 92 um, 93 mm, 94 um, 95 um, 96 um, 97 um, 98 um, 99 um, 100 um, 110 um, 120 um, 130 um, 140 um, 150 um, 160 um, 170 um, 180 um, 190 um, 200 um.

[0075] In some embodiments, the moving mechanism includes a turnover mechanism 50 and a conveying mechanism 90, wherein the turnover mechanism 50 is used to turn over at least one of the glass substrate 10 and the receiving substrate 20, so that the front surface 10a of the glass substrate 10 faces the direction where the receiving substrate 30 is located.

[0076] Specifically, the flipping mechanism 50 comprises a driving member (not shown) and a flipping clamp (not shown), wherein the flipping clamp can fix the glass substrate 10 by magnetic attraction, clamping, adsorption or the like, and the driving member can drive the clamp to flip, so as to realize the flipping of the glass substrate 10. Optionally, the driving member can be a motor, a stepper motor, a DD motor or the like.

[0077] Specifically, after the paste filling is completed, the glass substrate 10 can be flipped so that the front surface 10a of the glass substrate 10 faces the direction where the receiving substrate 20 is located. For example, when the receiving substrate 20 is located below the glass substrate 10, and the front surface 10a of the glass substrate 10 faces upward during the paste filling, after the paste filling is completed, the glass substrate 10 can be flipped by 180° clockwise or counterclockwise, so that the front surface 10a of the glass substrate 10 faces downward (i.e., faces the side where the receiving substrate 20 is located). The advantage of this arrangement is that, on the one hand, the filling of the paste in the groove 11 is facilitated, and on the other hand, the paste in the groove 11 is facilitated to be transferred to the receiving substrate 20. Alternatively, the receiving substrate 20 can be arranged on the side or above the glass substrate 10, and according to the different positions of the receiving substrate 20 relative to the glass substrate 10, the flipping angle and direction of the glass substrate 10 are also adaptively adjusted.

[0078] Alternatively, after the paste filling is completed, the angle of the glass substrate 10 can be kept unchanged, and the receiving substrate 20 can be moved or flipped, so that the front surface 10a of the glass substrate 10 faces the receiving substrate 20. In this case, the structure of the receiving substrate 20 is similar to that of the glass substrate 10, and thus the flipping mechanism 50 of the glass substrate 10 can be used to drive the receiving substrate 20 to flip. Of course, the glass substrate 10 and the receiving substrate 20 can be flipped simultaneously, so that the glass substrate 10 and the receiving substrate 20 are opposite to each other.

[0079] Further, the conveying mechanism 90 is used to convey the flipped glass substrate 10 and the receiving substrate 20 to a designated transfer station 60, and to keep the glass substrate 10 and the receiving substrate 20 opposite to each other at a certain interval.

[0080] Specifically, the designated transfer station 60 is used to define the positions of the glass substrate 10 and the receiving substrate 20, so as to ensure that the transfer process is not disturbed. A position where the conveying lines of the glass substrate 10 and the receiving substrate 20 intersect can be designated as the designated transfer station 60.

[0081] In some embodiments, the conveying mechanism 90 corrects the positions of the glass substrate 10 and the receiving substrate 20 when conveying the receiving substrate 20 and the glass substrate 10 to the transfer station 60. In this way, the positions of the grooves 11 on the glass substrate 10 can be matched with the positions of the desired grid lines on the receiving substrate 20, so as to ensure the transfer precision.

[0082] In some embodiments, the conveying mechanism 90 includes a CCD camera 91 and a transport device 92, wherein the CCD camera 91 is configured to take photos of the glass substrate 10 and the receiving substrate 20, and calculate displacement compensation of the glass substrate 10 and the receiving substrate 20 based on the photos, and the transport device 92 is configured to transport the glass substrate 10 and the receiving substrate 20 to the transfer station 60 based on the displacement compensation. Specifically, the CCD camera 91 is capable of taking photos of the glass substrate 10 and the receiving substrate 20, and determining displacement compensation of the glass substrate 10 and the receiving substrate 20 compared to the expected positions based on the photos. The displacement compensation includes displacement compensation in X, Y and θ directions, wherein θ refers to rotation compensation around the z axis (i.e. rotation angle correction in the horizontal plane). The displacement compensation is not limited to positive compensation, but also includes negative compensation. Alternatively, the glass substrate 10 and the receiving substrate 20 can be imaged by two CCD cameras 91 respectively, or can be imaged by only one CCD camera 91. Generally, two independent CCD cameras 91 are used to image the glass substrate 10 and the receiving substrate 20 respectively.

[0083] Further, after obtaining the displacement compensation of the glass substrate 10 and the receiving substrate 20 respectively, the transport device 92 can transport the glass substrate 10 and the receiving substrate 20 according to the displacement compensation of the glass substrate 10 and the receiving substrate 20 respectively, so that the glass substrate 10 and the receiving substrate 20 are exactly in the expected positions when reaching the transfer station 60, thus ensuring the position and precision of the paste transfer.

[0084] Specifically, the transport device 92 can include a position correction mechanism (not shown in the figure), which is configured to adjust the positions of the glass substrate 10 and the receiving substrate 20 according to the corresponding displacement compensation after obtaining the displacement compensation of the glass substrate 10 and the receiving substrate 20. It is worth noting that the position correction can be performed before the glass substrate 10 and the receiving substrate 20 enter the transfer station 60, or can be performed after the glass substrate 10 and the receiving substrate 20 enter the transfer station 60.

[0085] It is worth noting that the design of the present application is not limited to this, and in other embodiments, when correcting the positions of the glass substrate 10 and the receiving substrate 20, the position of only one of the glass substrate 10 and the receiving substrate 20 can be corrected, so that one matches the position of the other.

[0086] It can be understood that, since the glass substrate 10 and the receiving substrate 20 will be flipped before entering the transfer station 60, in order to ensure the alignment accuracy of the glass substrate 10 and the receiving substrate 20, the imaging of the glass substrate 10 and the receiving substrate 20 is performed after the flipping of the glass substrate 10 and / or the receiving substrate 20 is completed. Alternatively, the imaging of the glass substrate 10 and / or the receiving substrate 20 can be performed before the flipping of the glass substrate 10 and / or the receiving substrate 20 is completed.

[0087] Further, the conveying device 92 comprises a first conveying assembly 921 and a second conveying assembly 922, wherein the first conveying assembly 921 stepwise or continuously conveys the glass substrate 10 between the slurry filling mechanism 40, the flipping mechanism 50, the CCD imaging device 91 and the transfer station 60, and the second conveying assembly 922 stepwise or continuously conveys the receiving substrate 20 to the transfer station 60 and conveys the receiving substrate 20 after the transfer is completed away from the transfer station 60.

[0088] Herein, the stepwise conveying means that the glass substrate 10 is conveyed by a fixed distance each time, and after each conveying is completed, the glass substrate 10 is ensured to stay at the current position for a fixed time length; and the continuous conveying means that the glass substrate 10 is continuously conveyed without interruption.

[0089] Alternatively, the first conveying assembly 921 and the second conveying assembly 922 can be provided as any one of a rotary conveying assembly and a linear conveying assembly.

[0090] Specifically, the rotary conveying assembly has a rotation center, and a plurality of stations are provided at intervals on the periphery of the rotation center, and the rotary conveying assembly can drive the glass substrate 10 or the receiving substrate 20 to move between different stations when the rotary conveying assembly rotates.

[0091] The linear conveying assembly continuously conveys the receiving substrate 20 or the glass substrate 10 in a specified conveying direction, and a plurality of stations are provided at intervals along the conveying direction of the linear conveying assembly, and the linear conveying assembly can drive the glass substrate 10 and the receiving substrate 20 to pass through the plurality of stations in sequence.

[0092] Specifically, as shown in FIG. 4, the first conveying assembly 921 and the second conveying assembly 922 are provided as a rotary conveying assembly. Figure 2As shown, in some embodiments, the first transport component 921 and the second transport component 922 both adopt linear transport components. At this time, in the conveying direction of the first transport component 921, a slurry filling station 43, a flipping station 51, a CCD imaging station 911 and a transfer station 60 are provided in sequence, and in the conveying direction of the second transport component 922, a loading station 921a, a CCD imaging station 911, a transfer station 60 (overlapping with the transfer station 60 of the first transport component 921) and an unloading station 921b are provided in sequence, wherein the first transport component 921 and the second transport component 922 share the same transfer station 60. Correspondingly, each station of the first transport assembly 921 is equipped with a slurry filling mechanism 40, a turning mechanism 50, a CCD imaging device 91, and a light emitter 30; each station of the second transport assembly 922 is equipped with a loading mechanism (not shown), a CCD imaging device 91, a light emitter 30 (sharing the same light emitter 30 as the first transport assembly 921), and an unloading mechanism (not shown). This cycle allows for uninterrupted and repeated transfer.

[0093] like Figure 5 and Figure 6 As shown, in some embodiments, the first transport assembly 921 is a planar turntable transport assembly (specifically, the turntable's rotating shaft substrate is perpendicular to the horizontal plane), and the second transport assembly 922 is a linear transport assembly. In this case, the slurry filling station 43, the flipping station 51, the CCD imaging station 911, and the transfer station 60 are sequentially arranged in the rotation direction of the turntable transport assembly. Correspondingly, the slurry filling mechanism 40, the flipping mechanism 50, the CCD imaging device 91, and the light emitter 30 are sequentially arranged at each station of the turntable transport assembly. Furthermore, the loading station 921a, the CCD imaging station 911, the transfer station 60, and the unloading station 921b are sequentially arranged in the conveying direction of the second transport assembly 922. Correspondingly, the loading mechanism (not shown), the CCD imaging device 91, the light emitter 30 (sharing the same light emitter 30 as the first transport assembly 921), and the unloading mechanism (not shown) are correspondingly arranged at each station of the second transport assembly 922. This cycle allows for uninterrupted and repeated transfer.

[0094] like Figure 7 and Figure 8As shown, in some embodiments, both the first transport assembly 921 and the second transport assembly 922 are flat turntable transport assemblies. In this case, the slurry filling station 43, the flipping station 51, the CCD imaging station 911, and the transfer station 60 are sequentially arranged in the rotation direction of the first transport assembly 921. Correspondingly, the slurry filling mechanism 40, the flipping mechanism 50, the CCD imaging device 91, and the light emitter 30 are sequentially arranged at each station of the first transport assembly 921. Furthermore, the loading station 921a, the CCD imaging station 911, the transfer station 60, and the unloading station 921b are sequentially arranged in the rotation direction of the second transport assembly 922. Correspondingly, the loading mechanism (not shown), the CCD imaging device 91, the light emitter 30 (sharing the same light emitter 30 as the first transport assembly 921), and the unloading mechanism (not shown) are correspondingly arranged at each station of the second transport assembly 922. This cycle can achieve uninterrupted and repeated transfer.

[0095] like Figure 9 and Figure 10 As shown, in some embodiments, the first transport member 921 adopts a three-dimensional turntable transport component (specifically, the rotation axis of the turntable is parallel to the horizontal plane). Figure 9 and Figure 10 In the illustrated embodiment, the slurry filling station 43 and the transfer station 60 are arranged vertically around the rotation axis of the turntable transport assembly. Specifically, the slurry filling station 43 and the transfer station 60 are located on opposite sides of the turntable transport assembly, with the slurry filling station 43 located above the transfer station 60. The light emitter 30 is located between the slurry filling station 43 and the transfer station 60, facing the transfer station. The glass substrate 10 is fixed to the turntable transport assembly. When the turntable transport assembly rotates, the glass substrate 10 moves from the slurry filling station 43 to the transfer station 60 and automatically flips so that the front surface 10a faces downward. Correspondingly, a receiving substrate 20 is positioned at the transfer station 60 to receive the slurry. At this time, the light emitter 30 emits a laser beam or a non-laser beam toward the glass substrate 60, completing the slurry transfer. When the turntable transport assembly rotates again, the glass substrate 10 after transfer can be moved to the upper slurry filling station 43, and the glass substrate 10 filled with slurry can be moved to the lower transfer station 60 for subsequent transfer work. Figures 5 to 8 ) or a linear transport assembly. This cycle allows for uninterrupted and repeated transfer. It is worth noting that in a three-dimensional turntable transport assembly, in addition to the surface of the turntable facing the slurry filling station 43 and the transfer station 60, other surfaces can also be provided with glass substrates 10 for redundancy.

[0096] Through the above arrangement, the continuous use of the glass substrate 10 can be realized to improve the reusability of the glass substrate 10, and uninterrupted transfer can also be realized to significantly improve the transfer efficiency.

[0097] Further, the light emitter 30 is used to emit light towards the back surface 10b of the glass substrate 10 to transfer the paste in the groove 11 to the receiving substrate 20.

[0098] Specifically, the light emitter 30 can be arranged on the back surface 10b of the glass substrate 10, and the light emitter 30 emits light towards the back surface 10b of the glass substrate 10. The light can transfer energy to the paste in the groove 11 to make the paste in the groove 11 separate from the groove 11 and transfer to the receiving substrate 20. After the transfer is completed, the required product 80 can be obtained. In order to facilitate the transfer of the paste, the receiving substrate 20 is usually arranged below the glass substrate 10, and the front surface 10a of the glass substrate 10 faces downward and towards the receiving substrate 20.

[0099] In some embodiments, the light emitter 30 can be a laser emitter 30, and the light emitter 30 emits a laser beam towards the back surface 10b of the glass substrate 10.

[0100] Alternatively, a high-repetition pulse laser can be used to emit a continuous laser beam towards the back surface 10b of the glass substrate 10, and the laser beam is controlled to scan the groove 11 on the glass substrate 10 row by row according to a set order to transfer the paste in the groove 11 to the receiving substrate 20. Alternatively, the laser beam can also randomly scan the groove 11 on the glass substrate 10 without following a specific scanning order.

[0101] In some embodiments, the wavelength of the laser beam can be set to 800 nm to 1080 nm. Alternatively, the wavelength of the laser beam can be set to 800 nm, 910 nm, 980 nm, 1030 nm to 1080 nm, etc. Among them, in the wavelength range of 1030 nm to 1080 nm, the wavelength of the laser can be set to 1030 nm, 1031 nm, 1032 nm, 1033 nm, 1034 nm, 1035 nm, 1036 nm, 1037 nm, 1038 nm, 1039 nm, 1040 nm, 1041 nm, 1042 nm, 1043 nm, 1044 nm, 1045 nm, 1046 nm, 1047 nm, 1048 nm, 1049 nm, 1050 nm, 1051 nm, 1052 nm, 1053 nm, 1054 nm, 1055 nm, 1056 nm, 1057 nm, 1058 nm, 1059 nm, 1060 nm, 1061 nm, 1062 nm, 1063 nm, 1064 nm, 1065 nm, 1066 nm, 1067 nm, 1068 nm, 1069 nm, 1070 nm, 1071 nm, 1072 nm, 1073 nm, 1074 nm, 1075 nm, 1076 nm, 1077 nm, 1078 nm, 1079 nm, 1080 nm, etc. Of course, the design of the present application is not limited to this, and the wavelength of the laser beam can also be set to other values not specifically exemplified in 800 nm to 1080 nm, such as 900 nm, 950 nm, 1000 nm, etc.

[0102] It is worth noting that in the same transfer process, one wavelength of laser beam can be used, or different wavelengths of laser beam can be used at different stages.

[0103] In some embodiments, the power of the laser beam is set to 10W to 2000 W. For example, the power of the laser beam can be set to 10W, 15W, 20W, 25W, 30W, 35W, 40W, 45W, 50W, 55W, 60W, 65W, 70W, 75W, 80W, 85W, 90W, 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W, 200W, 210W, 220W, 230W, 240W, 250W, 260W, 270W, 280W, 290W, 300W, 310W, 320W, 330W, 340W, 350W, 360W, 370W, 380W, 390W, 400W, 410W, 420W, 430W, 440W, 450W, 460W, 470W, 480W, 490W, 500W, 510W, 510W, 520W, 530W 00W, 210W, 220W, 230W, 240W, 250W, 260W, 270W, 280W, 290W, 300W, 310W, 320W, 330 W, 340W, 350W, 360W, 370W, 380W, 390W, 400W, 410W, 420W, 430W, 440W, 450W, 460W, 4 70W, 480W, 490W, 500W, 510W, 520W, 530W, 540W, 550W, 560W, 570W, 580W, 590W, 600 W, 610W, 620W, 630W, 640W, 650W, 660W, 670W, 680W, 690W, 700W, 710W, 720W, 730W, 7 40W, 750W, 760W, 770W, 780W, 790W, 800W, 810W, 820W, 830W, 840W, 850W, 860W, 870W, 880W, 890W, 900W, 910W, 990W, 930W, 940W, 950W, 960W, 970W, 980W, 990W, 1000W, etc.

[0104] It is worth noting that in the same transfer process, a laser beam of the same power can be used, or laser beams of different powers can be used in different stages.

[0105] In some embodiments, the light emitter 30 is a non-laser emitter 30. In this case, the light emitter 30 emits a non-laser light beam. Specifically, the non-laser light beam includes incoherent light. Alternatively, the light emitter 30, such as a broadband flash lamp or a light-emitting diode (LED), can emit incoherent light toward the back surface 10 b of the glass substrate 10 to transfer the slurry in the groove 11 onto the glass substrate 10.

[0106] like Figure 11 As shown, in some embodiments, when grooves 11 of different widths can be simultaneously provided on the same glass substrate 10, for example, a silicon wafer (i.e., receiving substrate 20) typically has both coarse gates (also known as main gates) and fine gates, where the coarse gates are wider than the fine gates. For slurry transfer of silicon wafers having both coarse and fine gates, the glass substrate 10 is provided with coarse gate grooves 13 and fine gate grooves 12 corresponding to the coarse and fine gates.

[0107] Further, since the cost of the fine grid silver paste is not the same as that of the coarse grid silver paste (usually the cost of the fine grid silver paste is higher than that of the coarse grid silver paste), based on the cost consideration, the transfer is divided into two times, that is, the fine grid is transferred first, and then the coarse grid is transferred (vice versa). Among them, when the coarse grid is transferred, the coarse grid silver paste can be filled in all the coarse grid grooves 13 on the glass substrate 10 at the same time to complete the transfer of the coarse grid silver paste at one time; or the coarse grid silver paste can be filled in part of the coarse grid grooves 13 each time, and the transfer of the coarse grid silver paste on the glass substrate 10 is realized through multiple operations. Similarly, when the fine grid is transferred, the fine grid silver paste can be filled in all the fine grid grooves 12 on the glass substrate 10 at the same time to complete the transfer of the fine grid silver paste at one time; or the fine grid silver paste can be filled in part of the fine grid grooves 12 each time, and the transfer of the fine grid silver paste on the glass substrate 10 is realized through multiple operations. Similarly, when the fine grid is transferred,

[0108] Of course, the design of the present application is not limited to this, in some embodiments, the transfer of the coarse grid silver paste and the fine grid silver paste can also be carried out in the same transfer process in one transfer operation, that is, the transfer of the coarse grid silver paste and the fine grid silver paste is carried out at the same time in one transfer process.

[0109] It can be understood that the non-contact metallization system of the technical scheme of the present application carries out the carrying and transfer of the paste in the metallization system by replacing the flexible film with the glass substrate 10. In this way, not only can a higher precision and thinner and thicker paste pattern (corresponding to preparing a higher precision and thinner and thicker grid line on the photovoltaic cell) be obtained to obtain a photovoltaic cell with higher performance, but also the rigidity of the glass substrate 10 can be utilized to save the cost required for tensioning the flexible film. At the same time, compared with the flexible film, the glass substrate 10 is less worn and easier to clean, so that the glass substrate 10 has a higher reusability, thereby greatly reducing the cost of laser transfer. Therefore, the glass substrate 10 of the technical scheme of the present application not only can improve the performance of the photovoltaic cell, but also can reduce the cost of laser transfer.

[0110] Overall, compared with the prior art, the present application has the following beneficial effects:

[0111] (1) Non-contact: can be applied to non-contact photovoltaic cell preparation equipment and system, so that the silicon wafer does not need to be contacted during the transfer process, thereby better protecting the product and reducing the probability of product breakage, scratching, contamination, and hidden cracks, thereby facilitating the development of thin silicon wafers;

[0112] (2) Higher precision: not only can a grid line with a minimum line width of 3um be realized, but also since the glass substrate 10 is a rigid material, the flatness of the groove 11 edge can be ensured, so that the edge of the grid line obtained by transfer is neat, which is conducive to realizing a better aspect ratio, improving the battery conversion efficiency, and reducing the paste consumption.

[0113] (3) Good stability: the glass carrier plate has high surface flatness, high light transmittance, strong durability, and high reusability;

[0114] (4) Low cost: after the glass substrate 10 is used, there is no need to customize a steel mesh template, and the glass substrate 10 is easy to clean and has high reusability, so that consumables can be reduced and cost can be reduced.

[0115] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made under the inventive concept of the present application, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A non-contact metallization system for use in the preparation of photovoltaic cells, characterized in that: The metallization system comprises: A glass substrate having a front surface and a back surface opposite to each other, wherein the front surface is provided with a groove, wherein the width of the groove is not less than 3 μm, and the depth of the groove is not less than 5 μm; a slurry filling mechanism, configured to fill the grooves of the glass substrate with slurry; a moving mechanism for keeping the front surface of the glass substrate and the receiving substrate facing each other at a certain distance; and A light emitter is used to emit light toward the back of the glass substrate so that the slurry in the groove is transferred to the receiving substrate; wherein, The moving mechanism includes a flipping mechanism and a conveying mechanism, wherein the flipping mechanism is used to flip at least one of the glass substrate and the receiving substrate so that the front surface of the glass substrate faces the direction where the receiving substrate is located; The conveying mechanism performs position correction on the glass substrate and the receiving substrate when conveying the receiving substrate and the glass substrate to a designated transfer station, wherein: The conveying mechanism includes a CCD imaging device and a transport device. The CCD imaging device is used to capture photos of the glass substrate and the receiving substrate, and calculate the displacement compensation of the glass substrate and the receiving substrate based on the photos. The transport device transports the glass substrate and the receiving substrate to the transfer station based on the displacement compensation, wherein the displacement compensation includes displacement compensation in three directions of X, Y, and θ, and θ refers to the rotation compensation around the z-axis.

2. The contactless metallization system according to claim 1, characterized in that: The slurry filling mechanism includes a scraper, which is used to move along the front surface of the glass substrate at least once to fill the groove with slurry and scrape off the slurry on the surface of the glass substrate.

3. The contactless metallization system according to claim 2, wherein: The moving direction of the scraper is substantially perpendicular or substantially parallel to the extending direction of the groove.

4. The contactless metallization system according to claim 1, wherein: The transport device includes a first transport component, which circulates and transports the glass substrate among the slurry filling mechanism, the turning mechanism, the CCD imaging device and the transfer station in a step-by-step or continuous manner.

5. The contactless metallization system according to claim 4, characterized in that: The transport device includes a second transport component, which transports the receiving substrate to the transfer station in a step-by-step or continuous manner, and transports the receiving substrate after transfer is completed away from the transfer station.

6. The contactless metallization system according to claim 5, characterized in that: The first transport component includes any one of a turntable transport component and a linear transport component; and / or The second transport component includes any one of a turntable transport component and a linear transport component.

7. The contactless metallization system according to claim 6, wherein: The first transport component is a three-dimensional turntable transport component, the rotation axis of the three-dimensional turntable transport component is parallel to the horizontal plane, and the flipping of the glass substrate is completed by rotating the three-dimensional turntable transport component, and the light emitter is arranged on the inner side of the turntable of the three-dimensional turntable transport component.

8. The contactless metallization system according to claim 1, wherein: The distance between the front surface of the glass substrate and the receiving substrate is not less than 30 μm and not more than 200 μm.

9. The contactless metallization system according to claim 1, wherein: The light emitter is any one of a laser emitter and a non-laser emitter.

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