CN114334219B - Low-temperature curing silver paste for heterojunction solar cell and preparation method and application thereof - Google Patents
Low-temperature curing silver paste for heterojunction solar cell and preparation method and application thereof Download PDFInfo
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- 229910052709 silver Inorganic materials 0.000 title claims abstract description 87
- 239000004332 silver Substances 0.000 title claims abstract description 87
- 238000013035 low temperature curing Methods 0.000 title claims abstract description 34
- 238000002360 preparation method Methods 0.000 title abstract description 10
- 238000001723 curing Methods 0.000 claims abstract description 55
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 45
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- 238000005245 sintering Methods 0.000 claims abstract description 15
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- 238000006116 polymerization reaction Methods 0.000 claims description 51
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- 239000004841 bisphenol A epoxy resin Substances 0.000 claims description 15
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- 238000002156 mixing Methods 0.000 claims description 13
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- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 8
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
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- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical class C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 claims description 6
- PXKLMJQFEQBVLD-UHFFFAOYSA-N bisphenol F Chemical class C1=CC(O)=CC=C1CC1=CC=C(O)C=C1 PXKLMJQFEQBVLD-UHFFFAOYSA-N 0.000 claims description 6
- -1 dodecyl ester Chemical class 0.000 claims description 6
- HJOVHMDZYOCNQW-UHFFFAOYSA-N isophorone Chemical compound CC1=CC(=O)CC(C)(C)C1 HJOVHMDZYOCNQW-UHFFFAOYSA-N 0.000 claims description 6
- 239000003921 oil Substances 0.000 claims description 6
- 239000004593 Epoxy Substances 0.000 claims description 5
- 125000002091 cationic group Chemical group 0.000 claims description 5
- 239000000178 monomer Substances 0.000 claims description 5
- 239000004814 polyurethane Substances 0.000 claims description 5
- 229920002635 polyurethane Polymers 0.000 claims description 5
- PAAZPARNPHGIKF-UHFFFAOYSA-N 1,2-dibromoethane Chemical compound BrCCBr PAAZPARNPHGIKF-UHFFFAOYSA-N 0.000 claims description 4
- OAYXUHPQHDHDDZ-UHFFFAOYSA-N 2-(2-butoxyethoxy)ethanol Chemical compound CCCCOCCOCCO OAYXUHPQHDHDDZ-UHFFFAOYSA-N 0.000 claims description 4
- WUOACPNHFRMFPN-UHFFFAOYSA-N alpha-terpineol Chemical compound CC1=CCC(C(C)(C)O)CC1 WUOACPNHFRMFPN-UHFFFAOYSA-N 0.000 claims description 4
- 150000008064 anhydrides Chemical class 0.000 claims description 4
- SQIFACVGCPWBQZ-UHFFFAOYSA-N delta-terpineol Natural products CC(C)(O)C1CCC(=C)CC1 SQIFACVGCPWBQZ-UHFFFAOYSA-N 0.000 claims description 4
- 239000005543 nano-size silicon particle Substances 0.000 claims description 4
- 235000012239 silicon dioxide Nutrition 0.000 claims description 4
- 229940116411 terpineol Drugs 0.000 claims description 4
- IBLKWZIFZMJLFL-UHFFFAOYSA-N 1-phenoxypropan-2-ol Chemical compound CC(O)COC1=CC=CC=C1 IBLKWZIFZMJLFL-UHFFFAOYSA-N 0.000 claims description 3
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- AHDSRXYHVZECER-UHFFFAOYSA-N 2,4,6-tris[(dimethylamino)methyl]phenol Chemical compound CN(C)CC1=CC(CN(C)C)=C(O)C(CN(C)C)=C1 AHDSRXYHVZECER-UHFFFAOYSA-N 0.000 claims description 3
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 claims description 3
- 239000004348 Glyceryl diacetate Substances 0.000 claims description 3
- 239000006087 Silane Coupling Agent Substances 0.000 claims description 3
- XXBDWLFCJWSEKW-UHFFFAOYSA-N dimethylbenzylamine Chemical compound CN(C)CC1=CC=CC=C1 XXBDWLFCJWSEKW-UHFFFAOYSA-N 0.000 claims description 3
- JDVIRCVIXCMTPU-UHFFFAOYSA-N ethanamine;trifluoroborane Chemical compound CCN.FB(F)F JDVIRCVIXCMTPU-UHFFFAOYSA-N 0.000 claims description 3
- 235000019443 glyceryl diacetate Nutrition 0.000 claims description 3
- 150000002460 imidazoles Chemical class 0.000 claims description 3
- LLHKCFNBLRBOGN-UHFFFAOYSA-N propylene glycol methyl ether acetate Chemical compound COCC(C)OC(C)=O LLHKCFNBLRBOGN-UHFFFAOYSA-N 0.000 claims description 3
- 229960001124 trientine Drugs 0.000 claims description 3
- SNRUBQQJIBEYMU-UHFFFAOYSA-N Dodecane Natural products CCCCCCCCCCCC SNRUBQQJIBEYMU-UHFFFAOYSA-N 0.000 claims description 2
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- UXDDRFCJKNROTO-UHFFFAOYSA-N Glycerol 1,2-diacetate Chemical compound CC(=O)OCC(CO)OC(C)=O UXDDRFCJKNROTO-UHFFFAOYSA-N 0.000 description 1
- 238000005411 Van der Waals force Methods 0.000 description 1
- HVVWZTWDBSEWIH-UHFFFAOYSA-N [2-(hydroxymethyl)-3-prop-2-enoyloxy-2-(prop-2-enoyloxymethyl)propyl] prop-2-enoate Chemical compound C=CC(=O)OCC(CO)(COC(=O)C=C)COC(=O)C=C HVVWZTWDBSEWIH-UHFFFAOYSA-N 0.000 description 1
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- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
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- LQZZUXJYWNFBMV-UHFFFAOYSA-N ethyl butylhexanol Natural products CCCCCCCCCCCCO LQZZUXJYWNFBMV-UHFFFAOYSA-N 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
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- Conductive Materials (AREA)
- Photovoltaic Devices (AREA)
Abstract
The invention discloses low-temperature curing silver paste for a heterojunction solar cell, a preparation method and application thereof, wherein the low-temperature curing silver paste for the heterojunction solar cell comprises the following components: 89-93 parts of conductive silver powder, 2-7 parts of organic resin, 2-5 parts of solvent, 0.1-1 part of curing agent and 2.5-9 parts of auxiliary agent, wherein the conductive silver powder comprises main silver powder and sintered silver powder; the grain diameter of the main silver powder is 0.1-4 mu m, and the tap density of the main silver powder is 3.0-5.0 g/cm 3 The specific surface is 0.2-2.0 m 2 /g; the particle diameter of the sintering silver powder is 20-200 nm, and the specific surface area of the sintering silver powder is more than or equal to 3.0m 2 And/g. The low-temperature curing silver paste for the heterojunction solar cell is matched with the main silver powder and the sintering silver powder, so that the viscosity and rheological property of the low-temperature curing silver paste for the heterojunction solar cell are reduced, the grid line molding capacity is improved, and the aspect ratio is optimized, so that the low-temperature curing silver paste is suitable for fine line screen printing; in addition, the reduction of viscosity improves the printing speed and increases the production efficiency of the heterojunction solar cell.
Description
Technical Field
The invention relates to the field of solar cell silver paste, in particular to low-temperature curing silver paste for a heterojunction solar cell, and a preparation method and application thereof.
Background
The heterojunction solar cell is a high-efficiency crystalline silicon solar cell, is the solar cell with highest relative efficiency in the industrialized cells so far, has the efficiency as high as 27 percent and is the solar cell with the most development potential. The heterojunction solar cell adopts low-temperature curing silver paste, and the silver paste is generally mainly epoxy resin, polyester resin and acrylic resin at present. With the development of technology, in order to improve conversion efficiency and reduce surface recombination, each battery manufacturer has adopted fine-grid dense-grid technology (fine-line screen printing) of battery pieces. The fine grid dense grid means that the solar cell reduces the width of a grid line through a fine grid dense grid technology, and the aspect ratio is maximized, so that the shading area of the cell is reduced to the greatest extent, and the overall efficiency of the cell is improved.
However, the existing silver paste has higher content of micron-sized silver powder, so that the viscosity of the silver paste is higher, ideal balance among leveling, sagging, grid line width and grid line height of the paste is difficult to achieve, printing performance is poor, the silver paste cannot adapt to fine line screen printing, and the problems of grid line breakage, over-wide grid line width, over-low grid line height and the like of a battery are easy to occur.
Disclosure of Invention
The invention aims to provide low-temperature curing silver paste for a heterojunction solar cell, and a preparation method and application thereof, so as to solve the problem that the traditional silver paste is poor in printability and cannot be suitable for printing of a fine line screen.
To achieve the purpose, the invention adopts the following technical scheme:
the invention provides low-temperature curing silver paste for a heterojunction solar cell, which comprises the following raw materials in parts by weight:
wherein the conductive silver powder comprises a main silver powder and a sintered silver powder; the grain diameter of the main silver powder is 0.1-4 mu m, and the tap density of the main silver powder is 3.0-5.0 g/cm 3 The specific surface is 0.2-2.0 m 2 /g; the particle diameter of the sintering silver powder is 20-200 nm, and the specific surface area of the sintering silver powder is more than or equal to 3.0m 2 /g。
In the low-temperature curing silver paste for the heterojunction solar cell, the main silver powder comprises flaky silver powder and micron-sized spherical silver powder;
the particle size of the flake silver powder is 0.1-4 mu m, and the tap density of the flake silver powder is 3.0-5.0 g/cm 3 ;
The grain diameter of the micron-sized spherical silver powder is 0.4-2 mu m, and the tap density of the micron-sized spherical silver powder is 3.5-5.0 g/cm 3 The specific surface area of the micron-sized spherical silver powder is 0.2-2.0 m 2 /g。
In the low-temperature curing silver paste for the heterojunction solar cell, the weight ratio of the main silver powder to the sintered silver powder is 45:1 to 9:1.
in the low-temperature curing silver paste for the heterojunction solar cell, the organic resin comprises epoxy resin and auxiliary resin; the epoxy resin comprises low-polymerization epoxy resin and high-polymerization epoxy resin; the auxiliary resin is any one of acrylic resin or polyurethane resin;
the polymerization degree of the low-polymerization epoxy resin is 0.5-1.0, and the polymerization degree of the high-polymerization epoxy resin is 2.0-19.0;
the weight ratio of the low-polymerization epoxy resin to the high-polymerization epoxy resin to the auxiliary resin is (1-3): (1-3): (1-3).
In the low-temperature curing silver paste for the heterojunction solar cell, the low-polymerization epoxy resin comprises any one or a combination of a plurality of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin and bisphenol A diglycidyl ether;
the high-polymerization epoxy resin comprises any one or a combination of a plurality of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin and bisphenol A diglycidyl ether;
the acrylic resin comprises any one or a combination of a plurality of polyacrylic resin, acrylic monomer resin and epoxy modified acrylic resin;
the polyurethane resin includes any one of polyurethane resin and polyurethane modified resin.
In the low-temperature curing silver paste for the heterojunction solar cell, the solvent comprises any one or more of butyl carbitol, butyl carbitol acetate, DBE, dodecyl alcohol ester, terpineol, isophorone, propylene glycol methyl ether acetate, diethylene glycol butyl ether acetate, 1-phenoxy-2-propanol and diacetin.
In the low-temperature curing silver paste for the heterojunction solar cell, the curing agent comprises a main curing agent and a curing accelerator;
the main body curing agent comprises any one or a combination of more of an amine curing agent, a latent curing agent, an anhydride curing agent, an amine curing agent, a cationic curing agent and a modified imidazole curing agent;
the curing accelerator comprises any one or a combination of more of boron trifluoride monoethylamine, DMP-30, benzyl dimethylamine, imidazole and derivatives thereof, triethylene tetramine and diethylenetriamine.
In the low-temperature curing silver paste for the heterojunction solar cell, the auxiliary agent comprises a silane coupling agent and modified nano silicon dioxide.
The invention provides a preparation method of low-temperature curing silver paste for a heterojunction solar cell, which is used for preparing the low-temperature curing silver paste for the heterojunction solar cell and comprises the following steps of:
preparing an organic carrier: mixing and stirring organic resin and solvent according to a proportion to prepare an organic carrier;
mixing: mixing and stirring an organic carrier, conductive silver powder, an auxiliary agent and a curing agent according to the proportion under the oil bath condition of 75-85 ℃ for 7.5-8.5 hours to obtain semi-finished silver paste;
rolling: rolling the semi-finished silver paste to obtain the low-temperature solidified silver paste for the heterojunction solar cell.
The invention provides an application of low-temperature cured silver paste for heterojunction solar cells in fine line screen printing.
One technical scheme of the invention has the following beneficial effects:
the low-temperature curing silver paste for the heterojunction solar cell is matched with the main silver powder and the sintering silver powder, so that the viscosity and rheological property of the low-temperature curing silver paste for the heterojunction solar cell are reduced, the gate line molding capacity is improved, and the aspect ratio is optimized, so that the low-temperature curing silver paste is suitable for fine line screen printing; in addition, due to the reduction of the viscosity, the printing speed can be improved, and the production efficiency of the heterojunction solar cell can be improved.
Detailed Description
The technical scheme of the invention is further described by the following specific embodiments. The present invention is described more fully below in order to facilitate an understanding of the present invention. This invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
The examples are not to be construed as limiting the specific techniques or conditions described in the literature in this field or as per the specifications of the product. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
The invention provides low-temperature curing silver paste for a heterojunction solar cell, which comprises the following raw materials in parts by weight:
wherein the conductive silver powder comprises a main silver powder and a sintered silver powder; the main silverThe grain diameter of the powder is 0.1-4 mu m, and the tap density of the main silver powder is 3.0-5.0 g/cm 3 The specific surface area is 0.2-2.0 m 2 /g; the particle diameter of the sintering silver powder is 20-200 nm, and the specific surface area of the sintering silver powder is more than or equal to 3.0m 2 /g。
The low-temperature curing silver paste for the heterojunction solar cell is matched with the main silver powder and the sintering silver powder, so that the viscosity and rheological property of the low-temperature curing silver paste for the heterojunction solar cell are reduced, the gate line molding capacity is improved, and the aspect ratio is optimized, so that the low-temperature curing silver paste is suitable for fine line screen printing; in addition, due to the reduction of the viscosity, the printing speed can be improved, and the production efficiency of the heterojunction solar cell can be improved.
The main silver powder plays a role in conducting electricity, and compared with the main silver powder, the main silver powder has smaller particle size, so that the volume resistance of the main silver powder is lower than that of the sintered silver powder, the main silver powder has a better conducting effect, and the conversion efficiency of the battery is improved. In addition, because the main silver powder has the characteristic of high tap density, less resin and solvent are needed for wetting the surface of the main silver powder, a larger space is created for wetting the sintered silver powder, and the viscosity of the silver paste is reduced.
The particle size of the sintering silver powder is larger, the specific surface area is larger, and in the sintering curing process, more tight connection can be formed between the conductive silver powder and the sintering silver powder, so that the conductivity of the paste is ensured, more conductive channels are built in the silver paste, the conductivity, the contact resistance and the cohesiveness of the low-temperature curing silver paste for the heterojunction solar cell are improved.
Specifically, the main body silver powder includes plate-like silver powder and micron-sized spherical silver powder;
the particle size of the flake silver powder is 0.1-4 mu m, and the tap density of the flake silver powder is 3.0-5.0 g/cm 3 ;
The grain diameter of the micron-sized spherical silver powder is 0.4-2 mu m, and the tap density of the micron-sized spherical silver powder is 3.5-5.0 g/cm 3 The specific surface area of the micron-sized spherical silver powder is 0.2-2.0 m 2 /g。
The flake silver powder belongs to irregular type, the granularity is measured by a laser granularity meter, and the granularity (particle size) of the flake silver powder is 0.1-4 mu m.
The shape and the particle size of the flake silver powder and the micron-sized spherical silver powder are different, and after mixing, the silver powder has better compactness than the flake silver powder or the micron-sized spherical silver powder which is singly used, and the densification between the main silver powder and the sintered silver powder is promoted to form a good conductive layer, so that the silver powder has better conductivity.
Preferably, the weight ratio of the main silver powder to the sintered silver powder is 45:1 to 9:1.
as the proportion of the main silver powder is gradually increased, the viscosity of the silver paste gradually decreases, but when the viscosity of the silver paste is too low, the printability thereof is easily deteriorated, and the main manifestation is gate linewidth after printing and collapse. When the proportion of the main silver powder is too low, the tap density of the sintered silver powder is low, the specific surface is large, the viscosity of the prepared silver paste is large and is difficult to print, and in addition, the reduction of the main silver powder can improve the bulk resistance of the silver paste and reduce the conductivity of the silver paste. In a preferred embodiment of the present invention, the weight ratio of the main body silver powder to the sintered silver powder is 90:2, the silver paste has better conductivity and the viscosity meets the printing requirement of the fine line screen printing.
Specifically, the organic resin includes an epoxy resin and an auxiliary resin; the epoxy resin comprises low-polymerization epoxy resin and high-polymerization epoxy resin; the auxiliary resin is any one of acrylic resin or polyurethane resin;
the polymerization degree of the low-polymerization epoxy resin is 0.5-1.0, and the polymerization degree of the high-polymerization epoxy resin is 2.0-19.0;
the weight ratio of the low-polymerization epoxy resin to the high-polymerization epoxy resin to the auxiliary resin is (1-3): (1-3): (1-3).
In particular embodiments of the present invention, the low-polymeric epoxy resin and the high-polymeric epoxy resin are the same type of epoxy resin, except for the degree of polymerization, which results in different molecular weights of the two. The low-polymerization epoxy resin is in a liquid state or a semi-solid state, and the high-polymerization epoxy resin is in a semi-solid state or a solid state. The combination of epoxy resins with different degrees of polymerization can adjust the viscosity and rheological property of the low-temperature curing silver paste for the heterojunction solar cell.
The epoxy resin with low polymerization degree has low viscosity, poor solvent locking capability and small cohesive force; the epoxy resin with high polymerization degree has stronger solvent locking capability than that of the epoxy resin with low polymerization degree, and has stronger acting force with silver powder, but has larger viscosity, so that the epoxy resin is unfavorable for printing. The viscosity and rheological property of the low-temperature curing silver paste for the heterojunction solar cell are improved through the mixed use of the low-polymerization epoxy resin and the high-polymerization epoxy resin, and the high-viscosity characteristic of the high-polymerization epoxy resin can be made up, so that the problems of overlarge viscosity, poor printability and even difficulty in printing of the silver paste caused by overlarge content of the high-polymerization epoxy resin are avoided.
The auxiliary resin can improve the cohesion of silver paste, improve thixotropic property, has positive significance on the plasticity of the grid line, and has lower self resistance than epoxy resin. In a preferred embodiment of the present invention, the weight ratio of the low polymeric epoxy resin, the high polymeric epoxy resin and the auxiliary resin is 1:2:2.
further, the oligomeric epoxy resin comprises any one or more of bisphenol a epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol a epoxy resin, hydrogenated bisphenol F epoxy resin, and bisphenol a diglycidyl ether;
the high-polymerization epoxy resin comprises any one or a combination of a plurality of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin and bisphenol A diglycidyl ether;
the acrylic resin comprises any one or a combination of a plurality of polyacrylic resin, acrylic monomer resin and epoxy modified acrylic resin;
the polyurethane resin includes any one of polyurethane resin and polyurethane modified resin.
In a preferred embodiment of the present invention, the epoxy resin is bisphenol a epoxy resin, the polymerization degrees of the low-polymerization epoxy resin and the high-polymerization epoxy resin are respectively 0.8 and 5, the auxiliary resin is polyacrylic resin with a molecular weight of 5000, and the weight ratio of the low-polymerization epoxy resin to the high-polymerization epoxy resin to the auxiliary resin is 1:2:2, the viscosity (10/s) of the silver paste is 80 Pa.s, the thixotropic index is 5.0, and the printability is good.
Acrylic ester monomer resin and epoxy modified acrylic resin belong to pentaerythritol triacrylate, have polyfunctional monomer, through the oxygen-containing functional group on the acrylic resin molecular chain and epoxy resin, conductive silver powder, etc. form interaction forces such as hydrogen bond, van der Waals force, etc., crosslink into the network structure, improve thixotropic agent and printability of silver paste.
Still further, the solvent comprises any one or more of butyl carbitol, butyl carbitol acetate, DBE, dodecyl ester, terpineol, isophorone, propylene glycol methyl ether acetate, diethylene glycol butyl ether acetate, 1-phenoxy-2-propanol, and glyceryl diacetate.
The material is used as a solvent, so that the effects of dissolving resin, reducing slurry viscosity, improving printability and improving the aspect ratio of the grid line are achieved, the dispersibility of the conductive silver powder in silver paste is improved, and the conductive silver powder can be better dispersed in a carrier. In some preferred embodiments of the present invention, one or more of DBE, butyl carbitol acetate, and terpineol are selected as solvents.
Specifically, the curing agent comprises a main curing agent and a curing accelerator;
the main body curing agent comprises any one or a combination of more of an amine curing agent, a latent curing agent, an anhydride curing agent, an amine curing agent, a cationic curing agent and a modified imidazole curing agent;
the curing accelerator comprises any one or a combination of more of boron trifluoride monoethylamine, DMP-30, benzyl dimethylamine, imidazole and derivatives thereof, triethylene tetramine and diethylenetriamine.
The main body curing agent plays a role in improving the curing rate of the low-temperature curing silver paste for the heterojunction solar cell. The material is used as a curing agent, and has the characteristics of high curing speed, high yield strength, wear resistance, high hardness, high reliability and high compatibility with solvents. The curing accelerator is capable of accelerating the crosslinking speed between the curing agent and the epoxy resin. In some preferred embodiments of the present invention, isocyanate curing agents, cationic curing agents and amine curing agents are selected as curing agents.
Specifically, the auxiliary agent comprises a silane coupling agent and modified nano silicon dioxide. The auxiliary agent plays a role in reducing the viscosity of the main epoxy resin, and improves the compatibility between the conductive silver powder and the organic epoxy resin, thereby improving the dispersity of the conductive silver powder. And the adhesive force and the weldability of the welding strip can be improved, and the leveling property and the wettability of the low-temperature curing silver paste for the heterojunction solar cell can be improved. In some preferred embodiments of the present invention, modified nanosilica is selected as the adjunct.
The invention also provides a preparation method of the low-temperature cured silver paste for the heterojunction solar cell, which is used for preparing the low-temperature cured silver paste for the heterojunction solar cell and comprises the following steps of:
preparing an organic carrier: mixing and stirring organic resin and solvent according to a proportion to prepare an organic carrier;
mixing: mixing and stirring an organic carrier, conductive silver powder, an auxiliary agent and a curing agent according to the proportion under the oil bath condition of 75-85 ℃ for 7.5-8.5 hours to obtain semi-finished silver paste;
rolling: rolling the semi-finished silver paste to obtain the low-temperature solidified silver paste for the heterojunction solar cell.
In a specific embodiment of the invention, the semi-finished silver paste is rolled on a three-roller mill, so that all components of the low-temperature solidified silver paste for the heterojunction solar cell are uniformly dispersed. In the specific embodiment of the invention, the organic resin and the solvent are stirred under the oil bath condition of 80 ℃, and the organic resin can be melted by adopting an oil bath mode, so that the organic resin is fully dissolved; after 8 hours of stirring, the organic resin and the solvent are uniformly dispersed.
The invention also provides an application of the low-temperature cured silver paste for the heterojunction solar cell in fine line screen printing, and the low-temperature cured silver paste for the heterojunction solar cell is used.
Example group A
The preparation method of the low-temperature curing silver paste for the heterojunction solar cell comprises the following steps of:
preparing an organic carrier: mixing and stirring organic resin and solvent for 8 hours under the oil bath condition of 80 ℃ according to the table 1 to prepare an organic carrier;
mixing: mixing the organic carrier, the conductive silver powder, the auxiliary agent and the curing agent according to the proportion to obtain semi-finished silver paste;
rolling: rolling the semi-finished silver paste to obtain the low-temperature solidified silver paste for the heterojunction solar cell.
TABLE 1 raw material components of Low temperature cured silver paste for heterojunction solar cells in example group A
Wherein the particle size of the sintered silver powder is 40nm, and the specific surface area of the sintered silver powder is 2.5m 2 Per gram, the particle size of the flake silver powder is 0.1 μm, and the tap density of the flake silver powder is 3.5g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The grain diameter of the micron-sized spherical silver powder is 0.4 mu m, and the tap density of the micron-sized spherical silver powder is 3.5g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the Tap density of the main silver powder is 3.5g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The epoxy resin is bisphenol A epoxy resin, the auxiliary resin is polyurethane acrylic ester with the molecular weight of 5000, the curing agent is cationic curing agent, the solvent is butyl carbitol acetate, and the auxiliary agent is modified nano silicon dioxide.
Example group B
The preparation method of the example group B is the same as that of the example group A, and the raw material components of the example group B are shown in Table 2.
TABLE 2 raw material components of Low temperature cured silver paste for heterojunction solar cells in example group B
Wherein the particle size of the sintered silver powder is 190nm, and the specific surface area of the sintered silver powder is 2.0m 2 Per gram, the particle size of the flake silver powder is 3.5 μm, and the tap density of the flake silver powder is 4.5g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The grain diameter of the micron-sized spherical silver powder is 1.8 mu m, and the micron-sized spherical silver powderTap density of silver powder is 4.5g/cm 3 Tap density of the main silver powder is 4.5g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the The epoxy resin is bisphenol F epoxy resin, the auxiliary resin is epoxy modified acrylic resin, the curing agent is anhydride curing agent, the solvent is butyl carbitol, and the auxiliary agent is azo coupling agent.
Example group C
The preparation method of example group C, the conductive silver powder, the solvent, the curing agent and the auxiliary agent in the raw material components are the same as those of example group 1, and the proportion of the organic resin is shown in Table 3
TABLE 3 proportion of organic resins in example group C
Wherein the epoxy resin is bisphenol A epoxy resin, and the auxiliary resin is polyurethane acrylic ester with molecular weight of 5000.
The viscosities of the low-temperature cured silver pastes for heterojunction solar cells prepared in the above example group a, example group B and example group C were measured by a Brookfield viscometer, the volume resistivity was measured by a multimeter, printing was performed using the silver pastes, the aspect ratio was measured by a 3D microscope, and the printability was observed, and the test results were prepared in table 4.
Table 4-test results:
as can be seen from example group a, as the amount of the main silver powder gradually increases, the viscosity of the silver paste gradually decreases, but when the viscosity of the silver paste is too low, the printability thereof is deteriorated, which is mainly represented by the linewidth of the gate after printing, collapse, and when the ratio of the main silver powder to the sintered silver powder is 90:2, printability and conductivity are good.
According to the embodiment group B, when the ratio of the epoxy resin with low polymerization degree, the epoxy resin with high polymerization degree and the auxiliary resin is 1:2:2, effectively balancing the characteristics of the epoxy resin with low polymerization degree and the epoxy resin with high polymerization degree, improving the printability and meeting the printing requirements of a fine line screen.
As is clear from example group C, the polymerization degrees of the low-polymerization epoxy resin and the high-polymerization epoxy resin were 0.8 and 5, respectively, and the printability and the conductivity were good.
The technical principle of the present invention is described above in connection with the specific embodiments. The description is made for the purpose of illustrating the general principles of the invention and should not be taken in any way as limiting the scope of the invention. Other embodiments of the invention will occur to those skilled in the art from consideration of this specification without the exercise of inventive faculty, and such equivalent modifications and alternatives are intended to be included within the scope of the invention as defined in the claims.
Claims (8)
1. The low-temperature curing silver paste for the heterojunction solar cell is characterized by comprising the following raw materials in parts by weight:
89-93 parts of conductive silver powder
2-7 parts of organic resin
2-5 parts of solvent
0.1 to 1 part of curing agent
2.5 to 9 portions of auxiliary agent
Wherein the conductive silver powder comprises a main silver powder and a sintered silver powder; the weight ratio of the main silver powder to the sintering silver powder is 45:1 to 9:1, a step of; the particle diameter of the sintering silver powder is 20-200 nm, and the specific surface area of the sintering silver powder is more than or equal to 3.0m 2 /g;
The main silver powder comprises flake silver powder and micron-sized spherical silver powder;
the granularity of the flake silver powder is 0.1-4 mu m, and the tap density of the flake silver powder is 3.0-5.0 g/cm 3 ;
The grain diameter of the micron-sized spherical silver powder is 0.4-2 mu m, and the tap density of the micron-sized spherical silver powder is 3.5-5.0 g/cm 3 The specific surface area of the micron-sized spherical silver powder is 0.2-2.0 m 2 /g。
2. The low temperature cured silver paste for heterojunction solar cells as claimed in claim 1, wherein: the organic resin comprises epoxy resin and auxiliary resin; the epoxy resin comprises low-polymerization epoxy resin and high-polymerization epoxy resin; the auxiliary resin is any one of acrylic resin or polyurethane resin;
the polymerization degree of the low-polymerization epoxy resin is 0.5-1.0, and the polymerization degree of the high-polymerization epoxy resin is 2.0-19.0;
the weight ratio of the low-polymerization epoxy resin to the high-polymerization epoxy resin to the auxiliary resin is (1-3): (1-3): (1-3).
3. The low temperature cured silver paste for heterojunction solar cells as claimed in claim 2, wherein: the oligomeric epoxy resin comprises any one or a combination of a plurality of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin and bisphenol A diglycidyl ether;
the high-polymerization epoxy resin comprises any one or a combination of a plurality of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin and bisphenol A diglycidyl ether;
the acrylic resin comprises any one or a combination of a plurality of polyacrylic resin, acrylic monomer resin and epoxy modified acrylic resin;
the polyurethane resin includes any one of polyurethane resin and polyurethane modified resin.
4. The low temperature cured silver paste for heterojunction solar cells as claimed in claim 2, wherein: the solvent comprises any one or more of butyl carbitol, butyl carbitol acetate, DBE, dodecyl ester, terpineol, isophorone, propylene glycol methyl ether acetate, diethylene glycol butyl ether acetate, 1-phenoxy-2-propanol and diacetin.
5. The low temperature cured silver paste for heterojunction solar cells as claimed in claim 1, wherein: the curing agent comprises a main curing agent and a curing accelerator;
the main body curing agent comprises any one or a combination of more of an amine curing agent, a latent curing agent, an anhydride curing agent, an amine curing agent, a cationic curing agent and a modified imidazole curing agent;
the curing accelerator comprises any one or a combination of more of boron trifluoride monoethylamine, DMP-30, benzyl dimethylamine, imidazole and derivatives thereof, triethylene tetramine and diethylenetriamine.
6. The low temperature cured silver paste for heterojunction solar cells as claimed in claim 1, wherein: the auxiliary agent comprises a silane coupling agent and modified nano silicon dioxide.
7. A method for preparing a low-temperature cured silver paste for a heterojunction solar cell, which is characterized by comprising the following steps of:
preparing an organic carrier: mixing and stirring organic resin and solvent according to a proportion to prepare an organic carrier;
mixing: mixing and stirring the organic carrier, the conductive silver powder, the auxiliary agent and the curing agent according to the proportion under the oil bath condition of 75-85 ℃ for 7.5-8.5 h to obtain semi-finished silver paste;
rolling: rolling the semi-finished silver paste to obtain the low-temperature solidified silver paste for the heterojunction solar cell.
8. The application of the low-temperature cured silver paste for the heterojunction solar cell in fine line screen printing is characterized in that: a low-temperature cured silver paste for heterojunction solar cells according to any one of claims 1 to 6.
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CN114550976B (en) * | 2022-04-22 | 2022-08-16 | 西安宏星电子浆料科技股份有限公司 | Conductive silver paste for HIT solar cell |
CN114773794B (en) * | 2022-05-18 | 2023-04-25 | 无锡帝科电子材料股份有限公司 | Preparation method of conductive silver paste two-stage coactivated organic carrier |
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