Laser printing apparatus and laser printing method

Abstract

The invention relates to the technical field of laser printing, and discloses a laser printing device and a laser printing method. The laser printing method comprises the following steps that an electrode slurry layer is formed on the surface of a cleaned and activated carrier plate, a plurality of grid-line-shaped slurry is formed on the surface of the carrier plate through a scraper, the grid-line-shaped slurry is separated from the carrier plate and deposited on the surface of a silicon wafer through laser scanning, and a grid line electrode is formed. According to the technical scheme, a novel laser printing method is designed, the scraper is directly used for machining grid line type slurry on the surface of the carrier plate without grooves, the function of the groove structure is transferred to the scraper opening design by changing the slurry forming mode, technical obstacles caused by groove abrasion are fundamentally eliminated, and the production efficiency is improved. The replacement cost of consumables is greatly reduced; meanwhile, the electrode slurry is transferred to the surface of the silicon wafer by using lower laser power; in addition, the cleaning of the carrier plate is simpler and faster.

Description

Technical Field

[0001] The present invention relates to the technical field of laser printing, and in particular to a laser printing device and a laser printing method. Background Art

[0002] In the solar cell manufacturing process, traditional screen printing requires the design of screens with narrower openings and ultra-fine grid patterns. As grid line precision continues to improve, screen printing's grid line width and height precision are limited, making it difficult to produce micron-level fine grid lines. Laser printing involves irradiating a metal paste loaded on a transparent substrate with a laser, causing the metal paste to fall off the substrate's grooves and then transfer to the solar cell to form grid line electrodes.

[0003] The related technology requires pre-preparation of a transparent glass carrier or a transparent polymer film with grooves on the surface. However, due to the hard and brittle nature of glass, the edges of the grooves are easily worn by the coating scraper. When worn to a certain extent, the carrier will be scrapped and cannot be used anymore. The polymer film itself is not wear-resistant, so damage and scrapping will be more serious. Summary of the Invention

[0004] The main purpose of the present invention is to develop a new laser printing method, which does not require the preparation of a carrier plate with grooves, but can produce high-precision solar cell grid lines using a transparent carrier plate with a smooth surface.

[0005] To achieve the above object, the present invention proposes a laser printing method, which comprises the following steps:

[0006] S1. Providing a smooth transparent carrier plate, and sequentially cleaning and activating the surface of one side of the carrier plate;

[0007] S2, inverting the surface of the carrier plate after the activation treatment in step S1 and coating it with electrode slurry to form an electrode slurry layer;

[0008] S3. Providing a scraper with a plurality of openings on its blade side, inserting the blade side of the scraper into the electrode slurry layer and controlling the scraper to scrape along a first direction, so that a plurality of gate line-shaped slurries are formed on the surface of the carrier;

[0009] S4. Start the laser emitter above the carrier. As the laser scans the carrier, the gate line slurry separates from the carrier and deposits on the surface of the silicon wafer below the carrier to form a gate line electrode.

[0010] In one embodiment, in step S1, the surface of one side of the carrier is subjected to ultrasonic cleaning treatment at a frequency of 120 kHz to 200 kHz and a time of 2 minutes to 5 minutes.

[0011] In one embodiment, in step S1, the surface of one side of the carrier is subjected to plasma activation treatment, wherein the gas is oxygen, the flow rate is 5 sccm to 15 sccm, the power is 500 W to 800 W, the activation temperature is 80° C. to 150° C., and the activation time is 3 min to 8 min.

[0012] In one embodiment, in step S2, the viscosity of the electrode slurry is 50 Pa·s to 800 Pa·s.

[0013] In one embodiment, in step S2, the thickness of the electrode slurry layer is 6 μm to 35 μm.

[0014] In one embodiment, in step S2, the thickness uniformity of the electrode slurry layer is ≤4 μm.

[0015] In one embodiment, in step S3, when the scraper is scraping along the first direction, the blade side of the scraper is flush with the surface of the carrier plate, and the angle between the scraper plane and the first direction is 60° to 90°.

[0016] In one embodiment, in step S3, when the scraper scrapes along the first direction, the scraping speed is 10 cm / s to 20 cm / s.

[0017] In one embodiment, in step S3, when the scraper is scraping along the first direction, the pressure applied by the scraper to the surface of the carrier is 0.1 N / cm 2 ~0.5N / cm 2 .

[0018] In one embodiment, in step S3 , the width uniformity of the gate line slurry is ≤2 μm, and the height uniformity of the gate line slurry is ≤2 μm.

[0019] The present invention also proposes a laser printing device, which applies the laser printing method. The laser printing device includes: a carrier plate, which is a smooth and transparent carrier plate; and a scraper, wherein the blade side of the scraper is provided with a plurality of openings; and a laser emitter arranged above the carrier plate and a silicon wafer arranged below the carrier plate.

[0020] In one embodiment, the thickness of the blade side of the scraper is 0.05 mm to 2 mm.

[0021] In one embodiment, the scraper is made of a material selected from any one of alloy, rubber and plastic.

[0022] In one embodiment, the opening is a trapezoidal opening or a U-shaped opening.

[0023] In one embodiment, the width of the opening is 5 μm to 30 μm, and the width precision of the opening is ≤1 μm; the depth of the opening is 5 μm to 30 μm, and the depth precision of the opening is ≤1 μm.

[0024] In one embodiment, the carrier is a rigid carrier, and the material of the rigid carrier is selected from any one of glass, quartz, plastic, and diamond.

[0025] In one embodiment, the light transmittance of the carrier is greater than 85%.

[0026] In one embodiment, the distance between the carrier and the silicon wafer is 20 μm to 50 μm.

[0027] The technical solution of the present invention designs a new laser printing method, which directly uses a scraper to process the corresponding gate line slurry from the electrode slurry layer on the surface of an ultra-smooth carrier without grooves. The gate line slurry is then separated from the carrier by laser scanning and deposited on the surface of the silicon wafer to form the gate line electrode. By adopting this technical solution, there is no need to process the carrier and the scraper opening is not easily worn, which greatly reduces the replacement cost of consumables. Secondly, the electrode slurry directly adheres to the smooth carrier surface and is not affected by the friction of the groove sidewalls. The electrode slurry can be transferred to the silicon wafer surface using a lower laser power. In addition, compared with the technical solution of the prior art in which the carrier surface is provided with grooves, the cleaning of the carrier in the present invention is simpler and faster, and there is no need to worry about the problem of groove clogging caused by slurry, resulting in high cleaning costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0029] Figure 1 Schematic diagram of the structure of a scraper in one embodiment of the present invention;

[0030] Figure 2 Schematic diagram of scraping electrode slurry in one embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of laser printing in one embodiment of the present invention;

[0032] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. Description of the drawings:

[0034] 1. Scraper; 11. Opening; 2. Carrier; 3. Electrode slurry layer; 4. Gate line slurry; 5. Silicon wafer; 6. Gate line electrode; 7. Laser. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] In the production process of solar cells, forming electrode grid lines on the surface of silicon wafers is a key step. Existing technologies include screen printing and laser printing technologies. Due to the limited precision of grid line width and height, screen printing has difficulty in producing fine grid lines with a width of less than 20μm, resulting in a large resistance of the cell, which affects the photoelectric conversion efficiency. Laser printing technology, as a non-contact processing technology, can reduce the breakage rate of silicon wafers and is especially suitable for thin silicon wafers. In existing laser printing technology, it is necessary to pre-prepare a transparent glass carrier plate or polymer film with grooves on the surface. Due to the hard and brittle nature of glass, the edges of the grooves are easily worn by the coating scraper. Wear to a certain extent will cause the carrier plate to be scrapped; polymer films are not wear-resistant in nature, so the wear will be more serious.

[0039] In order to solve the above technical problems, a new laser printing method has been developed. It does not require pre-grooves on the surface of the carrier, and high-precision solar cell grid lines can be produced using a transparent carrier with a smooth surface.

[0040] The present invention provides a laser printing method, which includes the following steps:

[0041] S1. Providing a smooth transparent carrier plate, and sequentially cleaning and activating the surface of one side of the carrier plate;

[0042] S2, inverting the surface of the carrier plate after the activation treatment in step S1 and coating it with electrode slurry to form an electrode slurry layer;

[0043] S3. Providing a scraper with a plurality of openings on its blade side, inserting the blade side of the scraper into the electrode slurry layer and controlling the scraper to scrape along a first direction, so that a plurality of gate line-shaped slurries are formed on the surface of the carrier;

[0044] S4. Start the laser emitter above the carrier. As the laser scans the carrier, the gate line slurry separates from the carrier and deposits on the surface of the silicon wafer below the carrier to form a gate line electrode.

[0045] It should be noted that the laser printing method of the present invention uses a scraper with a specific structure to directly form a uniform slurry pattern on a smooth carrier, while retaining the advantages of laser printing technology. This idea fundamentally eliminates the technical obstacles caused by groove wear by changing the slurry forming method and transferring the function of the groove structure to the scraper opening design. The smooth carrier surface is ultrasonically cleaned and plasma treated to form a highly active surface, which enhances the wettability of the electrode slurry. During the inverted coating process, the slurry forms a uniform covering layer under the action of surface tension, eliminating the sagging phenomenon that is prone to occur in traditional upright coating. After the scraper with an opening is vertically inserted into the slurry layer and translated in the set direction, the slurry retained in the opening forms a regularly arranged strip structure under the action of shear force, thereby obtaining a grid-shaped slurry. When the laser beam scans along a preset path, light energy of a specific wavelength is absorbed by the slurry through the transparent carrier, generating a local thermal effect that reduces the adhesion between the slurry and the carrier, completing the patterned transfer. The entire process does not require relying on the physical limiting structure on the surface of the carrier.

[0046] In one embodiment, in step S1, the surface of one side of the carrier is subjected to ultrasonic cleaning treatment at a frequency of 120 kHz to 200 kHz and a time of 2 minutes to 5 minutes.

[0047] In one embodiment, in step S1, the surface of one side of the carrier is subjected to plasma activation treatment, wherein the gas is oxygen, the flow rate is 5 sccm to 15 sccm, the power is 500 W to 800 W, the activation temperature is 80° C. to 150° C., and the activation time is 3 min to 8 min.

[0048] It should be noted that during the ultrasonic cleaning process, the ultrasonic cavitation effect is used to remove pollutants such as oil or particulate residues on the surface of the carrier. Ultrasonic waves of 120kHz to 200kHz can effectively disperse pollutants and avoid microcracks in the carrier caused by high frequencies. Plasma activation generates polar groups such as hydroxyl or carboxyl groups on the surface of the carrier, thereby improving the wettability of the slurry. Among them, the oxygen flow rate is controlled at 5sccm to 15sccm to maintain stable discharge while avoiding airflow disturbances that affect processing uniformity. The power is set to 500W to 800W to ensure sufficient ion energy to activate the surface but avoid ablation of the carrier. The temperature range is 80℃ to 150℃ to promote the chemical reaction rate without causing deformation of the carrier.

[0049] In one embodiment, in step S2, the viscosity of the electrode slurry is 50 Pa·s to 800 Pa·s.

[0050] In one embodiment, in step S2, the thickness of the electrode slurry layer is 6 μm to 35 μm.

[0051] In one embodiment, in step S2, the thickness uniformity of the electrode slurry layer is ≤4 μm.

[0052] It should be noted that the components of the motor slurry include silver powder, glass powder, and organic resin. Controlling the viscosity of the electrode slurry to 50Pa·s to 800Pa·s can not only prevent the slurry from falling off the surface of the carrier after coating due to low viscosity, but also prevent excessive viscosity from hindering the uniform shaping of the slurry by the scraper. The thickness of the slurry layer matches the size of the scraper opening to ensure that the grid line slurry formed after scraping has a predetermined cross-sectional morphology. Thickness uniformity requires further constraints on the fluctuation range of the coating process to avoid grid line breakage or accumulation due to local thinness or excessive thickness of the slurry layer.

[0053] In one embodiment, in step S3, when the scraper is scraping along the first direction, the blade side of the scraper is flush with the surface of the carrier plate, and the angle between the scraper plane and the first direction is 60° to 90°.

[0054] In one embodiment, in step S3, when the scraper scrapes along the first direction, the scraping speed is 10 cm / s to 20 cm / s.

[0055] In one embodiment, in step S3, when the scraper is scraping along the first direction, the pressure applied by the scraper to the surface of the carrier is 0.1 N / cm 2 ~0.5N / cm 2 .

[0056] It should be noted that the flushing of the blade side with the carrier surface means that the lower edge of the scraper and the contact surface of the carrier are at the same horizontal plane. This can be achieved by using a laser rangefinder to monitor the blade position in real time to ensure that the electrode slurry layer is evenly and completely peeled off. The scraping speed is achieved by a servo motor driving the scraper moving mechanism. For example, a closed-loop control system is used to stabilize the moving speed within the range of 10-20 cm per second. This speed range takes into account both the slurry filling efficiency and the molding accuracy. The contact pressure is controlled by a pressure sensor and a pneumatic actuator. For example, a piezoelectric sensor is set on the back of the scraper to provide real-time feedback on the pressure value. This pressure range can maintain the adhesion strength of the slurry and avoid mechanical damage to the surface of the hard carrier. Through the above technical solution, the present application realizes the uniformity control of the width and height of the grid-shaped slurry, avoiding slurry residue or accumulation defects caused by improper angles during the scraping process. The coordinated control of contact pressure and scraping speed enables the slurry transfer process to improve processing efficiency while ensuring molding accuracy. The precise regulation of contact pressure effectively extends the service life of the hard carrier. The optimized setting of the scraper angle reduces the stress concentration at the scraper edge and reduces the generation of micro cracks on the carrier surface.

[0057] In one embodiment, in step S3 , the width uniformity of the gate line slurry is ≤2 μm, and the height uniformity of the gate line slurry is ≤2 μm.

[0058] It should be noted that width uniformity refers to the consistency of the lateral dimension distribution of the slurry layer, which can be achieved by adjusting the squeegee opening size accuracy and the uniformity of the squeegee pressure. Height uniformity refers to the consistency of the longitudinal thickness distribution of the slurry layer, which can be achieved by controlling the carrier surface flatness and the stability of the slurry viscosity. For example, the carrier surface roughness can be controlled to the nanometer level, while the slurry viscosity fluctuation range can be limited to within ±5%.

[0059] The present invention also proposes a laser printing device, which applies the laser printing method. The laser printing device includes: a carrier plate, which is a smooth and transparent carrier plate; and a scraper, wherein the blade side of the scraper is provided with a plurality of openings; and a laser emitter arranged above the carrier plate and a silicon wafer arranged below the carrier plate.

[0060] In one embodiment, the thickness of the blade side of the scraper is 0.05 mm to 2 mm.

[0061] It should be noted that the blade side thickness refers to the lateral dimension of the contact point between the blade body and the carrier plate. When the blade side thickness is between 0.05 mm and 2 mm, it can not only ensure that the scraper has sufficient rigidity to accurately control the forming of the slurry layer, but also avoid excessive pressure generated by an overly thick blade when contacting the carrier plate.

[0062] In one embodiment, the scraper is made of any one of alloy, rubber and plastic.

[0063] In a preferred embodiment, the scraper is made of stainless steel, which is harder and less prone to deformation.

[0064] It should be noted that alloy material refers to a hard material with metal elements as the main body, which can be specifically realized by stainless steel or titanium alloy. Its characteristics are high wear resistance and shape stability. Rubber material refers to a flexible material with polymer elastomer as the main body, which can be specifically realized by polyurethane or silicone rubber. Its characteristic is that it buffers contact stress through elastic deformation. Plastic material refers to an engineering material with polymer as the main body, which can be specifically realized by polyimide or polyetheretherketone. Its characteristics are that it has both wear resistance and moderate elasticity.

[0065] In one embodiment, the opening is a trapezoidal opening or a U-shaped opening.

[0066] It should be noted that the trapezoidal opening refers to a quadrilateral structure with two symmetrically distributed oblique sides in the cross section, which can be realized by CNC milling or laser cutting technology, and the oblique side angle is controlled within the range of 60° to 80°; the U-shaped opening refers to a symmetrical structure with a cross section that is a combination of a semicircle and a straight line segment, which can be realized by electrochemical etching or micro-stamping technology, and the arc radius is controlled within the range of 5μm to 15μm; the above-mentioned opening method can avoid the problem of local stress concentration caused by right-angled edges, and can also ensure that the slurry maintains a continuous form during the transfer process. Traditional rectangular openings are prone to stress concentration during the scraping process due to the right-angled edges, which leads to microcracks on the surface of the carrier and accelerated wear; although the V-shaped opening has a bevel structure, its sharp bottom is prone to residue when the slurry is filled, affecting the integrity of the grid line morphology. The trapezoidal and U-shaped openings of this application reduce mechanical damage and improve the fluidity of the slurry by optimizing geometric features.

[0067] In one embodiment, the width of the opening is 5 μm to 30 μm, and the width precision of the opening is ≤1 μm; the depth of the opening is 5 μm to 30 μm, and the depth precision of the opening is ≤1 μm.

[0068] It should be noted that the width accuracy of the opening refers to the fluctuation range of the distance between the two edges of the widest part of the opening after processing and forming; the depth accuracy of the opening refers to the fluctuation range of the distance between the bottom of the opening and the reference plane of the blade body after processing and forming; the dual control of width accuracy and depth accuracy ensures the geometric consistency of each opening, so that the slurry layer formed by scraping forms a highly uniform grid line structure after laser transfer.

[0069] In one embodiment, the carrier is a rigid carrier, and the material of the rigid carrier is selected from any one of glass, quartz, plastic, and diamond.

[0070] In one embodiment, the light transmittance of the carrier board is greater than 85%.

[0071] It should be noted that the present invention is beneficial to improving the utilization rate of laser energy by limiting the light transmittance of the carrier plate to a relatively high level.

[0072] In one embodiment, the distance between the carrier and the silicon wafer is 20 μm to 50 μm.

[0073] It should be noted that through the above-mentioned technical solution, the present application can ensure the deposition position accuracy of the gate electrode on the silicon wafer surface, reduce slurry residue or offset defects caused by insufficient laser energy, and avoid surface damage caused by contact between the carrier and the silicon wafer, thereby improving process stability and production yield.

[0074] The present invention is further described below by means of specific examples:

[0075] The raw materials used in the embodiments of the present invention are all commercially available, and the present invention does not impose any restrictions on the sources of the raw materials.

[0076] Example 1

[0077] The carrier plate in Example 1 is a transparent glass carrier plate with a light transmittance of about 90%; its surface finish meets the international standard ISO-10110-Class 2 and above.

[0078] The scraper in Example 1 is made of stainless steel, the thickness of the blade side of the scraper ranges from 0.05mm to 1mm, the opening is a trapezoidal opening, the width of the narrowest part of the opening is 20μm, the width of the widest part of the opening is 25μm, and the width accuracy of the opening is ≤1μm; the depth of the opening is 20μm, and the depth accuracy of the opening is ≤1μm.

[0079] The electrode slurry in Example 1 includes the following components by mass percentage:

[0080] Spherical nano silver powder (particle size 50nm-100nm): 75%; glass powder (B2O3): 10%; bisphenol A type epoxy resin: 10%; terpineol: 5%.

[0081] The viscosity of the electrode slurry in Example 1 is about 420 Pa·s.

[0082] The scraper in Example 1 is referenced Figure 1 , the blade side of the scraper 1 is provided with a plurality of trapezoidal openings 11 ( Figure 1 It appears as a rectangle, but is actually a trapezoidal opening).

[0083] Reference Figure 1 、 Figure 2 and Figure 3 The laser printing device in embodiment 1 includes: a carrier plate 2, and

[0084] A scraper 1 is provided with a plurality of openings 11 on the blade side of the scraper; a laser emitter is provided above a carrier plate 2 and a silicon wafer 5 is provided below the carrier plate 2.

[0085] The distance between the carrier 2 and the silicon wafer 5 is about 25 μm.

[0086] The laser printing method in Example 1 is as follows Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of using a scraper to scrape the electrode slurry layer to obtain a gate line slurry. Figure 3 This is a schematic diagram of laser printing a gate line slurry to form electrode gate lines on a silicon wafer.

[0087] The laser printing method in Example 1 comprises the following steps:

[0088] S1. The surface of one side of the carrier plate 2 is sequentially subjected to ultrasonic cleaning and plasma activation treatment; wherein, the ultrasonic cleaning frequency is 120 kHz and the time is 2 min; oxygen is used for plasma activation treatment with a flow rate of 15 sccm, a power of 800 W, an activation temperature of 80°C, and an activation time of 3 min.

[0089] S2, inverting the surface of the carrier plate 2 after the activation treatment in step S1 and coating it with electrode slurry to form an electrode slurry layer 3 with a thickness of about μm;

[0090] S3, provide a scraper 1 with a plurality of openings 11 on the blade side, insert the blade side of the scraper 1 into the electrode slurry layer 3 and control the scraper 1 to scrape along the first direction, and form a plurality of grid line slurries 4 (such as Figure 2 shown);

[0091] S4, start the laser emitter above the carrier 2, and as the laser 7 scans the carrier 2, the gate line slurry 4 separates from the carrier 2 and deposits on the surface of the silicon wafer 5 below the carrier 2, forming a gate line electrode 6 (such as Figure 3 shown).

[0092] The gate line electrode prepared in Example 1 has a width of about 25 μm and a height of about 18 μm.

[0093] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by utilizing the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A laser printing method, characterized in that: The laser printing method comprises the following steps: S1. Providing a smooth transparent carrier plate, and sequentially cleaning and activating the surface of one side of the carrier plate; S2, inverting the surface of the carrier plate after the activation treatment in step S1 and coating it with electrode slurry to form an electrode slurry layer; S3. Providing a scraper with a plurality of openings on its blade side, inserting the blade side of the scraper into the electrode slurry layer and controlling the scraper to scrape along a first direction, so that a plurality of gate line-shaped slurries are formed on the surface of the carrier; S4. Start the laser emitter above the carrier. As the laser scans the carrier, the gate line slurry separates from the carrier and deposits on the surface of the silicon wafer below the carrier to form a gate line electrode.

2. The laser printing method according to claim 1, wherein: In the step S1, the surface of one side of the carrier is subjected to ultrasonic cleaning treatment at a frequency of 120kHz to 200kHz for a time of 2min to 5min; And / or, in step S1, the surface of one side of the carrier is subjected to plasma activation treatment, wherein the gas is oxygen, the flow rate is 5sccm~15sccm, the power is 500W~800W, the activation temperature is 80℃~150℃, and the activation time is 3min~8min.

3. The laser printing method according to claim 1, wherein: In step S2, the viscosity of the electrode slurry is 50 Pa·s to 800 Pa·s; And / or, in step S2, the thickness of the electrode slurry layer is 6 μm to 35 μm; And / or, in step S2, the thickness uniformity of the electrode slurry layer is ≤4 μm.

4. The laser printing method according to claim 1, wherein: In step S3, when the scraper is scraping along the first direction, the blade side of the scraper is flush with the surface of the carrier plate, and the angle between the scraper plane and the first direction is 60° to 90°; And / or, in step S3, when the scraper scrapes along the first direction, the scraping speed is 10 cm / s to 20 cm / s; And / or, in step S3, when the scraper is scraping along the first direction, the pressure applied by the scraper to the surface of the carrier is 0.1 N / cm 2 ~0.5N / cm 2 .

5. The laser printing method according to claim 1, wherein: In the step S3 , the width uniformity of the gate line slurry is ≤2 μm, and the height uniformity of the gate line slurry is ≤2 μm.

6. A laser printing device, characterized in that: The laser printing device applies the laser printing method according to any one of claims 1 to 5, and the laser printing device comprises: A carrier board, wherein the carrier board is a smooth and transparent carrier board; and a scraper having a plurality of openings on its blade side; and A laser emitter is arranged above the carrier plate and a silicon chip is arranged below the carrier plate.

7. The laser printing device according to claim 6, wherein: The thickness of the blade side of the scraper is 0.05mm to 2mm; And / or, the scraper is made of any one of alloy, rubber and plastic.

8. The laser printing device according to claim 6, wherein: The opening is a trapezoidal opening or a U-shaped opening; And / or, the width of the opening is 5 μm to 30 μm, and the width accuracy of the opening is ≤ 1 μm; The depth of the opening is 5 μm to 30 μm, and the depth accuracy of the opening is ≤1 μm.

9. The laser printing device according to claim 6, wherein: The carrier plate is a rigid carrier plate, and the material of the rigid carrier plate is selected from any one of glass, quartz, plastic, and diamond; And / or, the light transmittance of the carrier board is greater than 85%.

10. The laser printing device according to claim 6, wherein: The distance between the carrier plate and the silicon wafer is 20 μm to 50 μm.

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