CN106876003A - Match solar battery front side conductive silver paste and preparation method without net netting version - Google Patents

Abstract

The invention discloses a solar cell front conductive silver paste matching a net-knot screen plate and a preparation method, including silver powder, glass powder, an organic binder and an auxiliary agent; wherein the organic binder includes an organic resin and an organic solvent; Organic resins include the first type of resin and the second type of resin; the ratio of the first type of resin to the second type of resin is 1:9-9:1; the organic solvent includes the first type of organic solvent with a relatively low boiling point, and the second type of organic solvent with a relatively medium boiling point. Class II organic solvents and Class III organic solvents with relatively high boiling points. In the present invention, through the combination of silver powder, glass powder, two resins with glass transition temperature Tg, three organic solvents with different boiling points and additives, the conductive silver paste on the front of the solar cell has a good adaptability to low line width and non-network wire. Screen printing metallization process, compared with the traditional conductive silver paste on the front side of solar cells, has better printing performance, higher aspect ratio, and better flatness of fine grid lines through the non-network screen printing metallization process, which can improve 0.1‑0.3% photoelectric conversion efficiency.

Description

Solar cell positive conductive silver paste matching non-knot screen plate and preparation method thereof

technical field

The invention belongs to the technical field of solar conductive silver paste, and in particular relates to a solar cell positive conductive silver paste matching a net-knot screen plate and a preparation method thereof.

Background technique

With the continuous consumption of conventional energy and the increasingly serious environmental problems, people pay more and more attention to seeking clean, efficient and renewable energy. As one of the most recognized energy sources, solar energy has been widely valued.

A solar cell is a device that converts light energy into electrical energy through the photoelectric effect. The working principle of the solar cell is: when sunlight shines on the crystalline silicon semiconductor p-n junction, new hole-electron pairs are formed. Under the action of the electric field of the p-n junction, the holes flow from the n region to the p region, and the electrons flow from the p region to the In the n region, a current is formed after the circuit is turned on. To make a solar cell, electrodes must be introduced on the front and back of the solar panel. The front electrode is formed by screen-printing the front conductive silver paste into a specific pattern, and then sintering at high temperature. The screen printing sub-grid used in the traditional front electrode uses a specific pattern with a mesh. The existence of the mesh restricts the thinning of the sub-grid and limits the increase in the aspect ratio of the fine grid, while the use of no mesh The screen printing screen can reduce the width of the fine grid lines, increase the light-receiving area of the front, increase the short-circuit current of the cell, and thus improve the photoelectric conversion efficiency of the cell; in addition, the traditional front conductive silver paste is screen-printed on the crystalline silicon On the surface, it is easy to collapse after being dried in a tunnel sintering furnace and sintered, and the aspect ratio cannot be maintained, thus failing to achieve the purpose of improving the aspect ratio of the fine grid lines and improving the current derivation ability of the cell, and the silk screen without mesh The screen plate can increase the aspect ratio of the printed pattern of the thin grid lines, reduce the volume resistance of the thin grid lines, improve the current derivation capability of the cell, and thus increase the photoelectric conversion efficiency of the cell.

In view of this, the present invention aims to develop a conductive silver paste on the front side of solar cells, which can be applied to the screen printing process without network knots, so as to reduce the shading area on the front side of solar cells and increase the aspect ratio of fine grid lines.

Contents of the invention

The technical problem mainly solved by the present invention is to provide a kind of solar cell front conductive silver paste and preparation method matching the net-knot screen plate, through silver powder, glass powder, two kinds of resins with glass transition temperature Tg, three kinds of organic compounds with different boiling points The combination of solvents and additives makes the conductive silver paste on the front of the solar cell well adapted to the metallization process of low-line-width non-network screen printing. Compared with the traditional screen printing metallization process, it has better printing performance and higher Higher aspect ratio, better flatness of thin grid lines, can improve photoelectric conversion efficiency by 0.1-0.3%.

In order to solve the above-mentioned technical problems, a technical solution adopted by the present invention is to provide a kind of solar cell positive conductive silver paste matching the net-knot screen plate, which comprises 85-90% of silver powder, glass powder and 0.5-3%, organic binder 5-11% and additives 0.2-3.5%; among them,

The median diameter D50 of the silver powder is 0.5-3 μm, the specific surface area is 0.1-1.0 m ² /g, and the tap density is 4.0-6.5 g/cm ³ ;

The organic binder (based on the total weight percentage of the organic binder) includes 5-20% of organic resin and 80-95% of organic solvent;

The organic resin includes a first type of resin with a low glass transition temperature Tg and a second type of resin with a high glass transition temperature Tg; wherein, the glass transition temperature Tg of the first type of resin is below room temperature, and the second type of resin has a high glass transition temperature Tg. The glass transition temperature Tg of the second type resin is above 80°C; the ratio of the first type resin to the second type resin is 1:9-9:1;

Described organic solvent comprises the first kind of organic solvent of relatively low boiling point, the second kind of organic solvent of relatively middle boiling point and the third kind of organic solvent of relatively high boiling point; Wherein, the boiling point range of described first kind of organic solvent is 150- 220°C, the boiling point range of the second type of organic solvent is 220-270°C, and the boiling point range of the third type of organic solvent is above 270°C; based on the total weight percentage of the organic solvent, the organic The solvent includes 2-20% of the first type of organic solvent, 60-95% of the second type of organic solvent and 2-20% of the third type of organic solvent.

Further, the first type of resin includes at least one of silicone resin, EVA resin, PVB resin, EVB resin, PVA resin, PVP resin, TPU resin, TPV resin, TPE resin and TPO resin;

The second type of resin includes at least one of acrylic resin, ethyl cellulose, cellulose acetate, rosin resin, polyester resin, amino resin and phenolic resin.

Further, the first type of organic solvent includes γ-butyrolactone, γ-valerolactone, dimethyl glutarate, furfural, cyclohexanol, diethyl succinate, diethyl glutarate and at least one of tributyl phosphate;

The second type of organic solvent includes at least one of diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, alcohol ester dodeca and tributyl citrate;

The third type of organic solvent includes at least one of tetraethylene glycol monobutyl ether, tetraethylene glycol, PETA and triethylene glycol.

Further, the auxiliary agent includes a thixotropic agent, the thixotropic agent accounts for 0.1-5% based on the total weight percentage of the conductive silver paste on the front side of the solar cell, and the thixotropic agent includes polyamide wax , at least one of modified hydrogenated castor oil and polyethylene wax.

Further, the ratio of the first type of resin to the second type of resin is 1:9-5:1.

Further, the silver powder has a median diameter D50 of 0.1-1 μm and a specific surface area of 1-10 m ² /g.

Further, the silver powder includes nano-silver powder or silver compound, and the nano-silver powder accounts for 0-5% based on the total weight percentage of the conductive silver paste on the front side of the solar cell.

Further, the adjuvants also include other adjuvants, and the other adjuvants include at least one of wetting agents, dispersants, defoamers and leveling agents.

The preparation method of the solar cell positive conductive silver paste of described matching no net knot screen plate, comprises the following steps:

A. Preparation of organic solvents: Mix the first type organic solvent, the second type organic solvent and the third type organic solvent according to a certain ratio, and use the disperser, emulsifier and mixer to mix the mixture evenly to obtain the mixed organic solvent;

B. Preparation of organic binder: add 5-20% by weight organic resin to 80-95% of the mixed organic solvent obtained in step A, stir for 1-2h, and obtain a uniform and transparent organic bond after dissolving agent;

C. Silver powder, glass powder, additives and the organic binder prepared in step B are 85-90% silver powder, 0.5-3% glass powder, 5-11% organic binder and 0.2-3.5% additive The proportion of the slurry is added to a centrifuge or a mechanical mixer to make it evenly mixed, and then it is put into a three-roll machine and ground for 2-6 times until the slurry fineness is less than 10 μm, so as to obtain a solar positive conductive silver paste.

The beneficial effects of the present invention have at least the following points:

1. The front conductive silver paste of solar cells of the present invention is different from the traditional front conductive silver paste. It is suitable for non-network screens, printed on the front of crystalline silicon cells by screen, and dried in a tunnel sintering furnace and sintered. It can maintain the static viscosity, thereby maintaining the shape of the fine grid line during the drying and sintering process, and obtain a fine grid line pattern with a good aspect ratio and a low grid line width;

Specifically, on the one hand, the present invention uses two types of resins with low and high glass transition temperatures Tg for reasonable proportioning. During the sintering process, as the temperature rises, the resin in the slurry whose glass transition temperature Tg is below room temperature makes the static viscosity of the slurry change little with temperature below the Tg temperature, and the resin whose glass transition temperature Tg is above 80°C The resin can keep the static viscosity of the slurry from normal temperature to above the Tg temperature. Therefore, the slurry of the present invention uses two kinds of resins to match, which can maintain the shape of the fine grid line at a lower temperature, and at the same time maintain a static state at a higher temperature. Viscosity does not change much; on the other hand, the present invention uses three types of organic solvents with relatively low, medium, and high boiling points in a reasonable proportion, and when the prepared solar positive conductive silver paste is printed on solar cells by a netless screen, In the process of drying and high-temperature sintering, as the temperature rises, the first type of organic solvent evaporates rapidly during drying, increasing the static viscosity of the slurry, thereby maintaining the aspect ratio of the fine grid lines, and at the same time matching the second type Organic solvents and third-class organic solvents can ensure long-lasting printing performance;

2. The conductive silver paste on the front side of the solar cell of the present invention contains highly active nano-silver powder or silver compounds. The median diameter D50 of the silver powder is 0.1-1 μm, and the specific surface area is ^1-10m2 /g. High sintering activity can form better contact with the surface of crystalline silicon, and the silver powder body is sintered more densely, so that the solar cell has lower contact resistance and line resistance;

3. The auxiliary agent contained in the conductive silver paste on the front side of the solar cell of the present invention includes a thixotropic agent, which can effectively prevent the sedimentation phenomenon during the storage of the conductive paste and increase the storage time, thereby avoiding the use of the conductive paste before use. The treatment of mixing and stirring for a long time; the thixotropic agent is preferably polyamide wax, which has the effect of further slowing down the sedimentation phenomenon and improving the performance of the conductive paste;

Four, the conductive silver paste on the front side of the solar cell of the present invention can obtain thin grid lines with a line width of 35-42 μm and a height of 15-20 μm, improve the aspect ratio of the thin grid lines, increase the light-receiving area on the front side of the solar cell, and improve short-circuit current , reduce the volume resistance of the thin grid lines, and increase the photoelectric conversion efficiency of the cell by 0.1-0.3%;

5. The preparation method of the solar cell front conductive silver paste of the present invention is simple, the operation is controllable, and it is easy to realize industrialization.

detailed description

The preferred embodiments of the present invention are described in detail below, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, so as to define the protection scope of the present invention more clearly.

Embodiment: A kind of solar cell positive conductive silver paste matching the net-knot screen plate, according to the total weight percentage of raw materials, including 85-90% of silver powder, 0.5-3% of glass powder, and 5-11% of organic binder And additives 0.2-3.5%; Among them,

The median diameter D50 of the silver powder is 0.5-3 μm, the specific surface area is 0.1-1.0 m ² /g, and the tap density is 4.0-6.5 g/cm ³ ;

The organic binder (based on the total weight percentage of the organic binder) includes 5-20% of organic resin and 80-95% of organic solvent;

The organic resin includes a first type of resin with a low glass transition temperature Tg and a second type of resin with a high glass transition temperature Tg; wherein, the glass transition temperature Tg of the first type of resin is below room temperature, and the second type of resin has a high glass transition temperature Tg. The glass transition temperature Tg of the second type resin is above 80°C; the ratio of the first type resin to the second type resin is 1:9-9:1;

Described organic solvent comprises the first kind of organic solvent of relatively low boiling point, the second kind of organic solvent of relatively middle boiling point and the third kind of organic solvent of relatively high boiling point; Wherein, the boiling point range of described first kind of organic solvent is 150- 220°C, the boiling point range of the second type of organic solvent is 220-270°C, and the boiling point range of the third type of organic solvent is above 270°C; based on the total weight percentage of the organic solvent, the organic The solvent includes 2-20% of the first type of organic solvent, 60-95% of the second type of organic solvent and 2-20% of the third type of organic solvent.

The first type of resin includes silicone resin, EVA (ethylene-vinyl acetate copolymer) resin, PVB (polyvinyl butyral) resin, EVB (vinyl styrene) resin, PVA (polyvinyl alcohol) resin, At least one of PVP (polyvinylpyrrolidone) resin, TPU (thermoplastic polyurethane) resin, TPV (thermoplastic vulcanizate) resin, TPE (thermoplastic elastomer) resin and TPO (thermoplastic polyolefin elastomer) resin, the TPU resin is preferably is at least one of Lubrizol 5703, 5707, 5714 and 5715;

The second type of resin includes at least one of acrylic resin, ethyl cellulose, cellulose acetate, rosin resin, polyester resin, amino resin and phenolic resin, and the acrylic resin is preferably DSM B-890 , B-811, B838, at least one of Mitsubishi MB-2952 and BR85, the ethyl cellulose is preferably at least one of Dow STD-4, STD-7, STD-20 and STD-50, The cellulose acetate is preferably at least one of EASTMAN CAB-551-0.01, CAB-551-0.2, CAB-381-0.1, CAB-381-2, CAB-381-20 and CAP-481-0.5, The rosin resin is preferably at least one of EASTMAN Foral 90, Foral 105-E, Foral 110, Pinava Pentalyn G, Pentalyn A and Pentalyn H.

The first class of organic solvents includes γ-butyrolactone, γ-valerolactone, dimethyl glutarate, furfural, cyclohexanol, diethyl succinate, diethyl glutarate and tributyl phosphate at least one of esters;

The second type of organic solvent includes at least one of diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, alcohol ester dodeca and tributyl citrate;

The third type of organic solvent includes at least one of tetraethylene glycol monobutyl ether, tetraethylene glycol, PETA (pentaerythritol triacrylate) and triethylene glycol.

The auxiliary agent includes a thixotropic agent, based on the total weight percentage of the conductive silver paste on the front side of the solar cell, the thixotropic agent accounts for 0.1-5%, preferably accounts for 0.5-1.5%, and the thixotropic agent Including at least one of polyamide wax, modified hydrogenated castor oil and polyethylene wax, preferably at least one of polyamide wax, Hemings THIXATROL (modified hydrogenated castor oil) ST, THIXATROL MAX and THIXATROL PLUS .

The ratio of the first type of resin to the second type of resin is 1:9-5:1. The proportion of the first type of resin and the second type of resin can ensure the function of the first type of resin and the second type of resin, and then obtain a low line width, good aspect ratio, suitable for solar cell front conduction without network knots Silver paste.

The median diameter D50 of the silver powder is 0.1-1 μm, and the specific surface area is 1-10 m ² /g.

The silver powder includes nano-silver powder or silver compound, and based on the total weight percentage of the conductive silver paste on the front side of the solar cell, the nano-silver powder accounts for 0-5%, preferably 0.1-2%.

The adjuvants also include other adjuvants, and the other adjuvants include at least one of wetting agents, dispersants, defoamers and leveling agents.

The preparation method of the solar cell positive conductive silver paste of described matching no net knot screen plate, comprises the following steps:

A. Preparation of organic solvents: Mix the first type organic solvent, the second type organic solvent and the third type organic solvent according to a certain ratio, and use the disperser, emulsifier and mixer to mix the mixture evenly to obtain the mixed organic solvent;

B. Preparation of organic binder: add 5-20% by weight organic resin to 80-95% of the mixed organic solvent obtained in step A, stir for 1-2h, and obtain a uniform and transparent organic bond after dissolving agent;

C. Silver powder, glass powder, additives and the organic binder prepared in step B are 85-90% silver powder, 0.5-3% glass powder, 5-11% organic binder and 0.2-3.5% additive The proportion of the slurry is added to a centrifuge or a mechanical mixer to make it evenly mixed, and then it is put into a three-roll machine and ground for 2-6 times until the slurry fineness is less than 10 μm, so as to obtain a solar positive conductive silver paste.

Embodiments 1-9 respectively enumerate the composition and weight percentage of the conductive silver paste on the front side of the solar cell, as shown in Table 1 below:

Composition and weight percentage of organic binder in embodiment 1 (based on the total weight percentage of the conductive silver paste on the front side of the solar cell): Foral 105-E 0.75%, Lubrizol 5703 0.25%, Penta Dimethyl dioic acid 0.25%, Alcohol ester twelve 2.75%, Diethylene glycol monobutyl ether acetate 2.75% and Triethylene glycol 0.25%.

Composition and weight percentage of organic binder in embodiment 2 (based on the total weight percentage of the conductive silver paste on the front side of the solar cell): Foral 105-E 0.4%, Lubrizol 5703 0.4%, acrylic acid 0.2% resin, 0.5% dimethyl glutarate, 3% alcohol ester dodecane, 3% diethylene glycol monobutyl ether acetate and 0.5% triethylene glycol.

Composition and weight percentage of organic binder in embodiment 3 (based on the total weight percentage of the conductive silver paste on the front side of the solar cell): Foral 105-E 0.6%, B-890 0.1%, Lubo Run 5703 0.3%, dimethyl glutarate 1%, alcohol ester twelve 2.9%, diethylene glycol monobutyl ether acetate 2.9% and triethylene glycol 1%.

Composition and weight percent of organic binder in embodiment 4 (based on the total weight percent of the front conductive silver paste of the solar cell): EVA resin 0.7%, Foral 105-E 0.5%, B-890 0.5%, dimethyl glutarate 0.5%, diethylene glycol monobutyl ether acetate 6.6% and triethylene glycol 0.5%.

Composition and weight percentage of organic binder in embodiment 5 (based on the total weight percentage of the conductive silver paste on the front side of the solar cell): Foral 105-E 0.5%, B-890 0.5%, Lubo Run 5703 0.5%, dimethyl glutarate 0.5%, alcohol ester twelve 6.0% and triethylene glycol 0.8%.

Composition and weight percent of organic binder in embodiment 6 (based on the total weight percent of the positive conductive silver paste of the solar cell): TPV resin 0.125%, amino resin 0.725%, phenolic resin 0.4%, Cyclohexanol 1.625%, tributyl citrate 5.5% and tetraethylene glycol monobutyl ether 1.625%.

Composition and weight percent of organic binder in embodiment 7 (based on the total weight percent of the positive conductive silver paste of the solar cell): EVA resin 0.4%, PVA resin 0.4%, STD-7 0.3% , CAB-381-20 0.5%, Foral 110 0.4%, γ-butyrolactone 0.7%, phospholipid tributyl ester 1.1%, alcohol ester twelve 5.4% and triethylene glycol 1.8%.

Composition and weight percentage of organic binder in embodiment 8 (based on the total weight percentage of the conductive silver paste on the front side of the solar cell): TPU resin 0.4%, TPO resin 0.5%, polyester resin 0.1% , furfural 0.6%, tributyl citrate 2.7%, tetraethylene glycol monobutyl ether 0.5% and triethylene glycol 0.2%.

Composition and weight percentage of organic binder in embodiment 9 (based on the total weight percentage of the conductive silver paste on the front side of the solar cell): EVB resin 1.25%, Foral 110 0.15%, B-811 0.1% , cyclohexanol 0.5%, diethyl succinate 0.5%, diethylene glycol monobutyl ether 2.5%, tributyl citrate 2% and tetraethylene glycol monobutyl ether 1%.

The front conductive silver pastes of solar cells of Examples 1-9 are respectively numbered ENCFP-1, ENCFP-2, ENCFP-3, ENCFP-4, ENCFP-5, ENCFP-6, ENCFP-7, ENCFP-8 and ENCFP-9 .

Comparative example: It is the traditional conductive silver paste on the front side of solar cells, and the G10A produced by our company is numbered as Reference.

Embodiment 1-9 and comparative example are carried out relevant performance detection:

1. Print the conductive silver paste on the front side of the solar cell prepared in the above examples 1-9 and comparative examples onto the crystalline silicon solar cell through a meshless screen, and print the resulting cell through the same high-temperature sintering The shape test of the pattern, the specific method is to use the KEYENCE VK-X 3D microscope to observe whether the printed pattern on the front of the solar cell is printed with conductive silver paste and sintered. The results show that: through observation, the conductive silver paste on the front side of the solar cell prepared in Examples 1-9 and the comparative example is well printed, and there are no false prints, broken grids, and blurred printed patterns.

2. Perform open circuit voltage (Voc), photoelectric conversion efficiency (EFF), fill factor (FF), parallel resistance (Rsh), and series resistance of the solar cell positive conductive silver paste prepared by the above-mentioned embodiments 1-9 and comparative examples. (Rs), short-circuit current (Isc), reverse current (Irev2) and other index performance tests, the test results are shown in Table 2 below, and the test methods for each index are conventional methods in the field, and the specific test process and conditions are adopted. Unified test environment and test conditions. Test method description: Electrical properties (including open circuit voltage Voc, photoelectric conversion efficiency EFF, fill factor FF, series resistance Rs, parallel resistance Rsh and short-circuit current Isc) are measured by solar simulator or IV tester. The light intensity of the light source used in the solar simulator or IV tester needs to be calibrated through the sealed "standard sheet" (sealed battery sheet), and the light intensity during measurement needs to be adjusted to the light intensity of AM1.5G (ie 1000mW/ cm ² ). During the electrical performance test, the cells to be tested are placed on a vacuum chuck under a light source, and the temperature of the chuck is controlled at 24 (±1)°C by a cooling device. The IV tester draws IV curves under bright field and dark field conditions by scanning voltage (-0.2V-+1.2V) and test current. Conventional battery sheet electrical performance data such as: photoelectric conversion efficiency EFF, open circuit voltage Voc, series resistance Rs, parallel resistance Rsh, short circuit current Isc and reverse current Irev2 can be obtained by IV tester under the above conditions. The photoelectric conversion efficiency EFF (equivalent to the fill factor FF) of the cell is a key parameter to measure the electrical performance of the cell. The fill factor is the ratio of the product of current and voltage to the product of short-circuit current and open-circuit voltage when the battery has the maximum output power. The results related to the electrical properties in the embodiments of the present invention can be obtained by an IV tester or related measurement tools in the cell industry.

3. Conduct the thin grid line width test and the thin grid line height test on the solar cell front conductive silver paste prepared in the above-mentioned examples 1-9 and comparative examples. X 3D microscope for measurements. The test results are shown in Table 3, and the test methods of each index are conventional methods in this field.

Table 2

As can be seen from Table 2, the solar cell front conductive silver paste prepared in Examples 1-9 of the present invention is printed on the crystalline silicon solar cell by net-knot screen printing to its photoelectric conversion efficiency, fill factor, parallel resistance, and series resistance performance All are good, and the photoelectric conversion efficiency is 0.1-0.3% higher than that of traditional slurry;

table 3

As can be seen from the data in Table 3, the conductive silver paste on the front side of the solar cell prepared by the embodiments of the present invention 1-9 can be printed on the crystalline silicon solar cell through a netless screen, which can significantly reduce the thickness of the fine grid lines. Width, increase the height of the thin grid lines, thereby increasing the aspect ratio of the thin grid lines.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural transformations made by the content of the present invention description, or directly or indirectly used in other related technical fields, are all included in the same principle. Within the scope of patent protection of the present invention.

Claims (9)

1. A solar cell front conductive silver paste that matches the net-knot screen plate, is characterized in that: by raw material gross weight percentage, comprises silver powder 85-90%, glass powder 0.5-3%, organic binder 5 -11% and additives 0.2-3.5%; of which, The median diameter D50 of the silver powder is 0.5-3 μm, the specific surface area is 0.1-1.0 m ² /g, and the tap density is 4.0-6.5 g/cm ³ ; The organic binder (based on the total weight percentage of the organic binder) includes 5-20% of organic resin and 80-95% of organic solvent; The organic resin includes a first type of resin with a low glass transition temperature Tg and a second type of resin with a high glass transition temperature Tg; wherein, the glass transition temperature Tg of the first type of resin is below room temperature, and the second type of resin has a high glass transition temperature Tg. The glass transition temperature Tg of the second type resin is above 80°C; the ratio of the first type resin to the second type resin is 1:9-9:1; Described organic solvent comprises the first kind of organic solvent of relatively low boiling point, the second kind of organic solvent of relatively middle boiling point and the third kind of organic solvent of relatively high boiling point; Wherein, the boiling point range of described first kind of organic solvent is 150- 220°C, the boiling point range of the second type of organic solvent is 220-270°C, and the boiling point range of the third type of organic solvent is above 270°C; based on the total weight percentage of the organic solvent, the organic The solvent includes 2-20% of the first type of organic solvent, 60-95% of the second type of organic solvent and 2-20% of the third type of organic solvent. 2. The solar cell positive conductive silver paste matching no net knot screen plate according to claim 1, characterized in that: said first type of resin comprises organic silicon resin, EVA resin, PVB resin, EVB resin, PVA resin, At least one of PVP resin, TPU resin, TPV resin, TPE resin and TPO resin; The second type of resin includes at least one of acrylic resin, ethyl cellulose, cellulose acetate, rosin resin, polyester resin, amino resin and phenolic resin. 3. The solar cell positive conductive silver paste matching the knotless screen plate according to claim 1, characterized in that: the first type of organic solvent comprises gamma-butyrolactone, gamma-valerolactone, glutaric acid At least one of dimethyl ester, furfural, cyclohexanol, diethyl succinate, diethyl glutarate and tributyl phosphate; The second type of organic solvent includes at least one of diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, alcohol ester dodeca and tributyl citrate; The third type of organic solvent includes at least one of tetraethylene glycol monobutyl ether, tetraethylene glycol, PETA and triethylene glycol. 4. the solar cell front conductive silver paste of matching no net knot screen plate according to claim 1, is characterized in that: described auxiliary agent comprises thixotropic agent, with the total weight percentage of described solar cell front conductive silver paste In terms of content, the thixotropic agent accounts for 0.1-5%, and the thixotropic agent includes at least one of polyamide wax, modified hydrogenated castor oil and polyethylene wax. 5 . The solar cell front conductive silver paste matching the knotless screen plate according to claim 1 , wherein the ratio of the first type resin to the second type resin is 1:9-5:1. 6 . The solar cell positive conductive silver paste matching the knotless screen plate according to claim 1 , characterized in that: the median diameter D50 of the silver powder is 0.1-1 μm, and the specific surface area is 1-10 m ² /g. 7. the solar cell front conductive silver paste of matching no net knot screen plate according to claim 1, is characterized in that: described silver powder comprises the compound of nano-silver powder or silver, with the total weight of described solar cell front conductive silver paste In terms of percentage, the nanometer silver powder accounts for 0-5%. 8. the solar cell front conductive silver paste of matching no net knot screen plate according to claim 4, is characterized in that: described auxiliary agent also comprises other auxiliary agent, and described other auxiliary agent comprises wetting agent, dispersant, At least one of a defoamer and a leveling agent. 9. the preparation method of the solar cell front conductive silver paste of matching no net knot screen plate according to claim 1, is characterized in that: comprise the following steps: A. Preparation of organic solvents: Mix the first type organic solvent, the second type organic solvent and the third type organic solvent according to a certain ratio, and use the disperser, emulsifier and mixer to mix the mixture evenly to obtain the mixed organic solvent; B. Preparation of organic binder: add 5-20% by weight organic resin to 80-95% of the mixed organic solvent obtained in step A, stir for 1-2h, and obtain a uniform and transparent organic bond after dissolving agent; C. Silver powder, glass powder, additives and the organic binder prepared in step B are 85-90% silver powder, 0.5-3% glass powder, 5-11% organic binder and 0.2-3.5% additive The proportion of the slurry is added to a centrifuge or a mechanical mixer to make it evenly mixed, and then it is put into a three-roll machine and ground for 2-6 times until the slurry fineness is less than 10 μm, so as to obtain a solar positive conductive silver paste.