A photosensitive resist ink and a method for manufacturing a metal gate line

Abstract

The application provides a photosensitive resist ink and a preparation method of metal grid lines in a photovoltaic cell. The raw material of the photosensitive resist ink comprises (A) an acrylic copolymer resin; (B) a photopolymerizable compound; and (C) a photoinitiator. The vinyl content of the photosensitive resist ink is 0.2-0.5 mol per 100 g of solid content. The molecular weight of the acrylic copolymer resin is 10-50 thousand. The photosensitive resist ink has good sensitivity, resolution and plating performance, so that a resist pattern with a smaller residual foot size can be formed, and the photosensitive resist ink has good comprehensive performance in the application of the photovoltaic cell and has an excellent application prospect.

Description

Technical Field

[0001] This application relates to the field of printed circuit board manufacturing technology, and in particular to a photosensitive resist ink and a method for preparing metal grid lines in photovoltaic cells. Background Technology

[0002] Photovoltaic cells typically conduct current by printing silver paste onto both sides of the cell and curing it at high temperatures to form grid electrodes. Screen printing conductive silver paste is currently the mainstream technology. However, the high consumption and cost of silver paste are among the pain points hindering the industrialization of N-type cells such as HJTs. The industry urgently needs innovative metallization processes to reduce costs and increase efficiency. One approach is to use copper instead of silver powder to reduce the amount of silver powder used, such as through copper electroplating technology.

[0003] The photovoltaic copper electroplating process mainly includes seed layer deposition, patterning, electroplating, and post-processing: First, a transparent conductive film (TCO) is deposited on the surface of the heterojunction cell. Then, a metal seed layer is deposited using PVD equipment. Next, a photosensitive resin layer is coated on the surface of the seed layer. After drying, selective light irradiation causes a chemical reaction in the photosensitive material in areas where copper plating is not desired, while the photosensitive material remains unchanged in areas where copper plating is desired. Then, the unmodified photosensitive material is removed by development to form a patterned mask. Next, electroplating is performed to deposit copper onto the exposed seed layer within the patterned area. Then, a protective layer is made on the copper surface, the mask is stripped off, and finally, the seed layer is removed by flash etching and surface treatment is performed to obtain the copper grid electrode.

[0004] When creating copper wire patterns, the ideal pattern for the exposed electroplated area cross-section is rectangular or trapezoidal, so that the width of the upper edge is less than or equal to the width of the lower edge of the grid line. If the resist cross-section is an inverted trapezoid, the copper deposited in the plating process will be an inverted trapezoidal shape that is wider at the top and narrower at the bottom, which will affect the photoelectric conversion efficiency of the solar cell.

[0005] Furthermore, during the development process, incomplete development can easily occur at the bottom of the sidewall near the exposure area, resulting in residual traces (or adhesive residue). This affects the adhesion between the plating layer and the seed layer, leading to poor conductivity of the electroplated grid lines. Therefore, it is necessary to develop a photosensitive resist composition capable of forming resist patterns with higher resolution and smaller residual trace sizes. Chinese application CN116449650A discloses a resist for photovoltaic cells, using photosensitive resin, photopolymerizable monomer, initiator, additives, and solid particles with a particle size of 0.1-2 micrometers to achieve a grid line with a trapezoidal cross-section for electroplated copper. However, this invention does not address sensitivity and resolution. Moreover, the use of 0.1-2 micrometer solid particles, which have a relatively large particle size, means that during development, these particles enter the developing solution. During the developing spray, these particles impact the surface of the cell, potentially causing scratches and damage, thus failing to meet application requirements. Summary of the Invention

[0006] The primary objective of this application is to provide a photosensitive resist ink capable of forming resist patterns with higher resolution and smaller residual size, thereby improving the application performance of existing photosensitive resist inks.

[0007] The photosensitive resist ink provided in this application comprises the following raw materials:

[0008] (A) Acrylic copolymer resin;

[0009] (B) Photopolymerizable compounds;

[0010] (C) Photoinitiator;

[0011] The photosensitive resist ink has a vinyl content of 0.2-0.5 mol per 100 grams of solids, preferably 0.2-0.44 mol; and / or the acrylic copolymer resin has a molecular weight of 10,000-50,000, preferably 10,000-40,000.

[0012] By adopting the above technical solution, considering the improvement of photoresist sensitivity and cross-sectional morphology, the vinyl content is 0.2 mol or more per 100 grams of the composition (i.e., photosensitive resist ink) after deducting solvent components. Considering the peelability of the cured product, the vinyl content is 0.5 mol per 100 grams of the composition after deducting solvent components, particularly less than 0.44 mol. This application's reasonable control of the vinyl content in the photosensitive resist ink can effectively improve the efficiency and pattern quality of the photolithography process, especially accuracy (such as resolution and imaging quality) and film-forming properties (film quality and physicochemical properties).

[0013] From the perspective of improving resolution and reducing residual ink residue, the weight-average molecular weight of acrylic copolymer resin should be 50,000 or less; from the perspective of avoiding the formation of a trapezoidal cross-sectional shape in the resist, the weight-average molecular weight of acrylic copolymer resin is preferably 10,000 or more; the weight-average molecular weight of alkali-soluble resin is more preferably 10,000 to 40,000. By selecting acrylic copolymer resins within a specific molecular weight range, this application can further optimize the photosensitivity, imaging resolution, stability, and adhesion to the substrate of the ink.

[0014] The photosensitive resist ink provided in this application preferably further includes (D) an ultraviolet absorber, which has the ability to absorb light with a wavelength of 300 to 450 nm.

[0015] As a (D) ultraviolet absorber, it can be any absorber that has a wavelength of 300-450nm. It can be an inorganic ultraviolet absorber or an organic ultraviolet absorber, or a combination of organic and inorganic absorbers.

[0016] As an inorganic ultraviolet absorber, it can be selected from one or more of carbon black (Tianjin Jindadi Chemical, SM100), nano cerium oxide (Zhitai Nano Micro, ZT-Ce01), nano zinc oxide (Beijing Deco Island Gold Technology, DK-ZnO-15), and nano titanium oxide (Beijing Deco Island Gold Technology, DK405), with carbon black and nano zinc oxide being particularly preferred.

[0017] As an organic ultraviolet absorber, it can be selected from one or more of benzophenone derivatives, benzoate derivatives, benzotriazole derivatives, triazine derivatives or benzoxazine compounds.

[0018] As benzophenone derivatives, options include 2,2'-hydroxy-4-methoxybenzophenone (Nanjing Milan Chemical, BP-8), 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (Nanjing Milan Chemical, BP-6), and 2,2',4,4'-tetrahydroxybenzophenone (Nanjing Milan Chemical, BP-2). As benzoic acid ester derivatives, options include diethylaminohydroxybenzoylhexylbenzoate (Nanjing Milan Chemical, UV-A PLUS) and 3,5-di-tert-butyl-4-hydroxybenzoate n-hexadecyl ester (Nanjing Milan Chemical, UV-2908). As benzotriazole derivatives, the following can be selected: 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (Nanjing Milan Chemical, UV-P), 2-(2'-hydroxy-3',5'-bis(a,a-dimethylbenzyl)phenyl)benzotriazole (Nanjing Milan Chemical, UV-234), 2-(-hydroxy-3-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole (Nanjing Milan Chemical, UV-326), 2-(2'-hydroxy-3',5'-ditert-butylphenyl)-5-chlorobenzotriazole (Nanjing Milan Chemical, UV-327), 2-(2'-hydroxy-3',5'-ditert-pentylphenyl)benzotriazole (Nanjing Milan Chemical, UV-328), 2,2'-methylenebis[6- (2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol] (Nanjing Milan Chemical, UV-360), etc. As triazine derivatives, they can be selected from 2-[4-[2-hydroxy-3-tetadecaoxypropyl]oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine and a mixture of 2-[4-[2-hydroxy-3-dodecyloxypropyl]oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (Nanjing Milan Chemical, UV-400), 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-[3-[(2-ethylhexyl)] [Oxy]-2-hydroxypropoxyphenol (Nanjing Milan Chemical, UV-405), etc. As a benzoxazine, 2,2'-(1,4-phenylene)bis-4H-3,1-benzoxazine-4-one (Nanjing Milan Chemical, UV-3638) can be selected.

[0019] Particularly preferred is an organic UV absorber, which may be selected from one or more of 2,2',4,4'-tetrahydroxybenzophenone (Nanjing Milan Chemical, BP-2), 2-(-hydroxy-3-tert-butyl-5"-methylphenyl)-5-chlorobenzotriazole (Nanjing Milan Chemical, UV-326) and diethylaminohydroxybenzoyl benzoate (Nanjing Milan Chemical, UV-A PLUS), preferably one or two.

[0020] (D) The ultraviolet absorber can be used alone or in combination of two or more. Relative to the total amount of 100 parts by weight of components (A), (B), and (C), the amount of ultraviolet absorber (D) is preferably 0.04 to 5.1 parts by weight; more preferably 1 to 3.9 parts by weight, such as 0.1 to 1.9 parts by weight (excluding the maximum value in this range, the same below), 1.9 to 2.5 parts by weight, 2.5 to 3.9 parts by weight, 3.9 to 5.1 parts by weight, etc. Specific ideal amounts include 0.1 parts by weight, 1.9 parts by weight, 2.5 parts by weight, 3.9 parts by weight, 5.1 parts by weight, etc.

[0021] From the perspective of deep curing properties being beneficial to the formation of an inverted trapezoidal cross-sectional morphology in cured products, it is preferable that the amount of (D) UV absorber is 0.04 parts by weight or more, while from the perspective of photosensitivity, the amount of (D) UV absorber is 5 parts by weight or less.

[0022] When a specific range of (D) UV absorbers is introduced into the resin system, the (D) UV absorbers absorb UV light within a specific wavelength range through exposure. Along the thickness direction of the resist layer, the closer to the bottom of the resist (the side of the seed layer of the battery cell), the more UV light is absorbed, thus forming a curing gradient. The bottom side of the resist layer is slightly less cured than the surface side. During development, the bottom side of the resist layer is more easily eroded by the developer, eventually forming a groove formed by the resist layer. The width of the upper side of the groove is smaller than the width of the lower side of the groove. During electroplating, a grid line with a trapezoidal cross-section is finally formed.

[0023] The photosensitive resist ink provided in this application has a refractive index higher than 1.48 at 20°C and a wavelength of 589.3 mm.

[0024] The mechanism of refraction angle is not yet fully understood, but based on experimental results, the following hypothesis is proposed: In photosensitive resist inks, the control of refractive index not only affects the precision and efficiency of the photolithography process but also influences the quality of the final pattern. Although the light source of the exposure equipment is parallel, the exposed light rays cannot be perfectly parallel and still have a certain degree of divergence. This means that during exposure, the incident light rays in the photosensitive resist composition are not completely perpendicular to the resist coating and still have a certain angle of incidence. When light propagates through a resist coating with a higher refractive index, it has a smaller angle of refraction. Therefore, the light rays propagate more perpendicular to the resist layer, resulting in better resolution.

[0025] The photosensitive resist ink provided in this application preferably contains at least one of the copolymer units with structural formulas as shown in formulas (I), (II), and (III) in component (A) of the acrylic copolymer resin.

[0026]

[0027] R1, R3, and R5 are each independently selected from any one of hydrogen atoms or methyl groups, and R2, R4, and R6 are each independently selected from any one of hydrogen atoms, alkyl groups, alkoxy groups, aryl groups or substituted aryl groups, hydroxyl groups, or halogen atoms.

[0028] Preferably, the amount of copolymer units represented by formulas (I), (II), and (III) is preferably 1 to 75% of the acrylic copolymer resin of (A), more preferably 5 to 70%.

[0029] As another technical solution of this application, (A) the acrylic copolymer resin contains the copolymer unit shown in structural formula (IV), which can be used alone or in combination with the copolymer units shown in formulas (I), (II), and (III).

[0030]

[0031] R7 is either a hydrogen atom or a methyl group;

[0032] Preferably, the amount of copolymer units of the (IV) structural general type accounts for 10-30% of the total weight of the (A) acrylic copolymer resin, more preferably 10-25%.

[0033] In addition to the comonomers mentioned above, (A) acrylic copolymer resin may further contain other comonomers, specifically selected from one or more of methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, hexyl methacrylate, decyl methacrylate, lauryl methacrylate, tetrahydrofuran methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0034] More specifically, component (A) acrylic copolymer resin is selected from one or more of the following: acrylate-phenoxyethyl acrylate-methyl methacrylate-ethyl acrylate, acrylate-styrene-benzyl methacrylate-methyl methacrylate, acrylate-benzyl methacrylate-methyl methacrylate-butyl acrylate, methacrylate-styrene-methyl methacrylate-ethyl acrylate, methacrylate-phenoxyethyl acrylate-styrene-methyl methacrylate-ethyl acrylate, methacrylate-methyl methacrylate-ethyl acrylate, and methacrylate-styrene-methyl methacrylate-ethyl acrylate.

[0035] The preparation method of the acrylic copolymer resin described in this application can be a known method, such as solution polymerization, bulk polymerization, suspension polymerization, etc., which is known to those skilled in the art, and this application does not make any special limitation on it.

[0036] From the perspective of improving resolution, reducing residual material, and improving cross-sectional morphology, the weight average molecular weight of (A) acrylic copolymer resin should be 50,000 or less. From the perspective of avoiding the formation of a trapezoidal cross-sectional shape for the resist, the weight average molecular weight of (A) acrylic copolymer resin is preferably 10,000 or more, and more preferably 10,000 to 40,000 for (A) alkali-soluble copolymer resin.

[0037] Preferably, relative to the total amount of components (A), (B), and (C) of 100 parts by weight, the weight proportion of acrylic copolymer resin (A) is preferably 49-69 parts by weight, more preferably 49-64 parts by weight, and even more preferably 50-68 parts by weight. Specific ideal proportions include 49.7 parts by weight, 51.1 parts by weight, 53.2 parts by weight, 56.2 parts by weight, 57.3 parts by weight, 58.2 parts by weight, and 63.1 parts by weight.

[0038] The photosensitive resist ink provided in this application preferably contains (B) a photopolymerizable compound comprising a (meth)acrylate compound having three or more vinyl groups in its molecular structure. Such compounds may be selected from glycerol tri(meth)acrylate, propoxylated glycerol tri(meth)acrylate, ethoxylated glycerol tri(meth)acrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate, and ethoxylated trimethylolpropane tri(meth)acrylate. Acrylates, propoxylated trimethylolpropane tri(meth)acrylate, ethoxypropoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, ethoxypropoxylated pentaerythritol tri(meth)acrylate Ethoxylated propoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, ethoxylated dipentaerythritol tri(meth)acrylate, propoxylated dipentaerythritol tri(meth)acrylate, ethoxylated propoxylated dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, ethoxylated dipentaerythritol tetra(meth)acrylate, propoxylated dipentaerythritol tetra(meth)acrylate, ethoxylated propoxylated dipentaerythritol tetra(meth)acrylate One or more of the following: methacrylate, pentaerythritol pentamethacrylate, ethoxylated pentaerythritol pentamethacrylate, propoxylated pentaerythritol pentamethacrylate, ethoxylated propoxylated pentaerythritol pentamethacrylate, pentaerythritol hexamethacrylate, ethoxylated pentaerythritol hexamethacrylate, propoxylated pentaerythritol hexamethacrylate, and ethoxylated propoxylated pentaerythritol hexamethacrylate.

[0039] In certain specific embodiments provided in this application, (B) the photopolymerizable compound may further contain other (meth)acrylate compounds having one or more vinyl groups in their molecular structures. Such compounds may be selected from one or more of the following: lauryl methacrylate, isooctyl methacrylate, decyl methacrylate, phenoxyethyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, ethoxylated propoxylated bisphenol A di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polyethylene glycol propylene glycol di(meth)acrylate, and tricyclodecanediethanol di(meth)acrylate.

[0040] More specifically, (B) the photopolymerizable compound is preferably selected from one or more of the following: tripropylene glycol diacrylate, 4-(ethoxy)bisphenol A dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate, particularly one, two, or three. Selecting the above-mentioned photopolymerizable compounds helps to ensure the photocuring speed of the ink (especially in terms of compatibility and compatibility with the photoinitiator described in this application), resolution (helps to reduce light scattering and improve imaging resolution), adhesion (mainly the bonding with the resin substrate), and durability, and more particularly enables the resist ink to obtain good sensitivity and cross-sectional morphology.

[0041] From the perspective of improving photosensitiveness and cross-sectional morphology, it is preferable that the vinyl content is 0.20 mol or more per 100 grams of solids in the total composition. From the perspective of peelability of the cured product, it is preferable that the vinyl content is 0.44 mol or less per 100 grams of the total composition after deducting the solvent component.

[0042] Preferably, relative to the total amount of 100 parts by weight of component (A), component (B), and component (C), the weight proportion of photopolymerizable compound (B) is 28 to 46 parts by weight, more preferably 30 to 45 parts by weight, and even more preferably 35 to 42 parts by weight. Specific ideal proportions include 34.9 parts by weight, 35.5 parts by weight, 36.8 parts by weight, 38.9 parts by weight, 40.3 parts by weight, 40.9 parts by weight, 41.6 parts by weight, and 44.7 parts by weight.

[0043] The photosensitive resist ink provided in this application uses (C) a photoinitiator that is a commonly used substance in the field of photocuring, such as one or more of benzoin ether, benzophenone and its derivatives, thioxanthone compounds, anthraquinone and its derivatives, acridine compounds, thioxanthone compounds, hexaaryl diimidazole compounds, pyrazoline compounds, and anthracene compounds (mixed in any proportion), preferably hexaaryl diimidazole compounds or acridine compounds.

[0044] More preferably, (C) the photoinitiator may be selected from: benzoin ether, benzophenone, thioxanthone, anthraquinone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1 4-Naphthoquinone, 9,10-Phenanthroquinone, 2,3-Dimethylanthraquinone, 9-Phenylacetidine, 1,7-(9,9'-Acridinyl)heptane, Benzoin methyl ether, Benzoin ethyl ether, Benzoin phenyl ether, Benzoin dimethyl ketal, Benzoin dimethyl ether, Benzoin ethyl ether, Benzoin propyl ether, Benzoin phenyl ether, Thioxanone, 2-Chlorothioxanone, 4-Chlorothioxanone, 2-Isopropylthioxanone, 4-Isopropylthioxanone, Benzophenone, 4,4'-Bis(dimethylamino)benzophenone (Mischel ketone), 4,4'-Bis(diethylamino)benzophenone, Isopropylthioxanthraquinone, 2-chlorothioxanthraquinone, 2,4-diethylthioxanthraquinone, 2-tert-butylanthraquinone, ethyl N,N-dimethylbenzoate, dimethylaminoethyl benzoate, N,N-dimethylethanolamine, 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazolium One or more of the following: azole dimer, 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, phenyl-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, and 9,10-di(4-methoxyphenyl)-2-chloroanthracene.

[0045] (C) The photoinitiator is particularly preferably one or more of 9-phenylacridine, 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, tetraethylmielone, dibutoxyanthracene and 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, preferably one, two or three. Using the above-mentioned photoinitiator (C) helps to improve the photocuring speed (mainly based on the photoinitiation activity level), imaging resolution, adhesion (mainly based on its interaction force with the resin substrate surface during photocuring) and process adaptability. Based on the selection of the photoinitiator, especially when the light source emission wavelength is 355nm or 405nm, the photosensitivity of the resist can be effectively improved.

[0046] Preferably, relative to the total amount of components (A), (B), and (C) of 100 parts by weight, the amount of photoinitiator (C) is 0.9 to 8.1 parts by weight, preferably 1.4 to 6.9 parts by weight, such as 1.4 to 1.6 parts by weight, 4.9 to 8.1 parts by weight, etc., and specific ideal amounts are such as 1.4 parts by weight, 1.6 parts by weight, 4.9 parts by weight, 5.2 parts by weight, 5.6 parts by weight, 5.9 parts by weight, 6.9 parts by weight, 8.1 parts by weight, etc.

[0047] In addition to the components mentioned above, the photosensitive resist ink provided in this application may also contain other additives (F).

[0048] Other additives (F) include heat-inhibiting agents, silane coupling agents, plasticizers, flame retardants, antistatic agents, anti-aging agents, antibacterial and antifungal agents, defoamers, leveling agents, fillers, thickeners, adhesion promoters, thixotropic promoters, colorants, photoinitiators, sensitizers, curing accelerators, anti-sticking agents, surface treatment agents, dispersants, surface modifiers, stabilizers, and phosphors. Commonly used additives include defoamers, leveling agents, colorants, dispersants, and curing accelerators. Specific selections are made by those skilled in the art based on actual needs, and this application does not impose any particular limitations on this. Preferably, other additives (F) used in this application include diamond green, 5-carboxybenzotriazole, defoamer Shin-Etsu KS-66 (Japan), and leveling agent DIGIC FLOW300.

[0049] Regarding the amount of other additives (F), generally relative to the total amount of components (A), (B), and (C) described in 100 parts by weight, the weight ratio of other additives (F) is preferably 0.3 to 1 part by weight, more preferably 0.5 to 0.9 parts by weight, and specific ideal ratios such as 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, etc.

[0050] The photosensitive resist ink provided in this application can be further diluted with a solvent, namely (G) solvent, to adjust the viscosity as needed. The (G) solvent is selected from one or more of alcohols, ketones, ethers, aromatic hydrocarbons, or esters. Specifically, it can be selected from: alcohols such as diethylene glycol, dipropylene glycol, butanol, and diacetone alcohol; ketones such as butanone, cyclohexanone, isophorone, diisobutyl ketone, and methyl butyl ketone; ethers such as ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, diethoxyethanol, dipropylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol methyl ether; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; and esters such as butyl acetate, butyl lactate, dipropylene glycol methyl ether acetate, and diethylene glycol ethyl ether acetate.

[0051] As particularly preferred, the solvent for (G) is diisobutyl ketone and / or dipropylene glycol methyl ether.

[0052] Further preferably, the amount of solvent (G) is 55 to 175 parts by weight, more preferably 58 to 166 parts by weight, relative to the total amount of 100 parts by weight of components (A), (B) and (C).

[0053] The photosensitive resist ink of this application also includes (E) fumed silica as a raw material. This (E) fumed silica can be selected from various known products commonly used in the art, with Degussa A200 being preferred. The main function of this component in this application is to achieve thixotropy. When not used, it has virtually no impact on the important properties of the resist layer, such as photosensitivity, resolution, cross-sectional morphology, residual material, and anti-plating properties. When added, it facilitates the application of the resist solution using screen printing and other sizing methods; there are no particular restrictions on the type used.

[0054] Preferably, relative to the total amount of components (A), (B), and (C) in 100 parts by weight, the weight proportion of fumed silica (E) is preferably 0-5.1 parts by weight; more preferably 1.5-4 parts by weight, such as 1.5-2.7 parts by weight, 2.7-5.1 parts by weight, etc., and specific ideal proportions such as 1.5 parts by weight, 1.6 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.7 parts by weight, 3.5 parts by weight, 3.8 parts by weight, 4.0 parts by weight, 5.1 parts by weight, etc.

[0055] In a preferred embodiment of this application, the photosensitive resist ink includes...

[0056] (A) 50-68 parts by weight of acrylic copolymer resin (preferably 50-60 parts by weight);

[0057] (B) 28-44 parts by weight of photopolymerizable compound (preferably 30-38 parts by weight);

[0058] (C) 2-6 parts by weight of photoinitiator (preferably 4-6 parts by weight);

[0059] (D) 0 to 5.1 parts by weight of ultraviolet absorber (preferably 0.05 to 2.2 parts by weight);

[0060] (E) Fumed silica 0-5.1 parts by weight (preferably 1.5-2 parts by weight);

[0061] (G) A suitable amount of solvent (preferably 55 to 175 parts by weight, more preferably 110 to 120 parts by weight).

[0062] Preferably, the resist ink has a vinyl content of 0.2 to 0.44 mol per 100 grams of solid composition, and the acrylic copolymer resin has a molecular weight of 10,000 to 50,000. More preferably, the ultraviolet absorber has the ability to absorb light with a wavelength of 300 nm to 450 nm.

[0063] The photosensitive resist ink provided in this application can be prepared using various known processes, preferably by the following method: fumed silica, solvent, etc. are added to a sealed container and dispersed using a sand mill disperser, then an initiator, ultraviolet absorber, other additives, and photopolymerizable compound are added and dispersed using a sand mill disperser, and finally an acrylic copolymer resin is added and dispersed evenly using a sand mill disperser.

[0064] The specific preparation conditions are known to those skilled in the art, and this application does not impose any particular limitations on them.

[0065] The second objective of this application is to provide a method for preparing metal grid lines in photovoltaic cells, wherein the aforementioned photosensitive resist ink is screen-printed onto the seed conductor layer of the photovoltaic cell and then dried to obtain a photosensitive resist layer.

[0066] An exposure process in which active light selectively passes through a photosensitive resist layer to form a photocurable portion; and a development process in which the photosensitive resist layer outside the photocurable portion is removed, to obtain a resist pattern on a photovoltaic cell.

[0067] A photovoltaic cell with a resist pattern is coated to form a metal grid pattern; the photovoltaic cell with the metal grid pattern is stripped to obtain the metal grid.

[0068] By adopting the above technical solution, the layer structure obtained by curing the aforementioned photosensitive resist ink, combined with the corresponding processing steps, can form metal grid lines with a cross-sectional pattern of "trapezoidal". The pattern has excellent performance and high resolution, thereby ensuring that the photovoltaic cell has excellent photoelectric conversion effect. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0070] The component information involved in the various embodiments and comparative examples provided in this application is as follows:

[0071] A-1: Acrylic acid - phenoxyethyl acrylate - methyl methacrylate - ethyl acrylate = 10-5-70-15, weight average molecular weight: 39,200

[0072] A-2: Acrylic acid-styrene-benzyl methacrylate-methyl methacrylate = 25-50-20-5, weight average molecular weight: 11,000

[0073] A-3: Acrylic acid-benzyl methacrylate-methyl methacrylate-butyl acrylate = 14-15-60-11, weight average molecular weight: 31,500

[0074] A-4: Methacrylate-styrene-methyl methacrylate-ethyl acrylate = 19-35-36-10, weight average molecular weight: 23,300

[0075] A-5: Methacrylate-Phenylacetoxyethyl acrylate-Styrene-Methyl methacrylate-Ethyl acrylate = 24-10-45-11-10, Weight-average molecular weight: 15,600

[0076] A-6: Methacrylate-methyl methacrylate-ethyl acrylate = 24-61-15, weight average molecular weight: 25,300

[0077] A-7: Methacrylate-styrene-methyl methacrylate-ethyl acrylate = 19-35-36-10, weight average molecular weight: 72,000

[0078] B-1: Tripropylene glycol diacrylate, Miramer M222

[0079] B-2:4 (ethoxy)bisphenol A dimethacrylate, Miramer M241

[0080] B-3: Trimethylolpropane trimethacrylate, Sartoma SR350

[0081] B-4: Pentaerythritol tetraacrylate, Sartoma SR295

[0082] B-5: Dipentaerythritol pentaacrylate, Sartoma SR399

[0083] B-6: Dipentaerythritol hexaacrylate, Miramer M600

[0084] C-1: 9-Phenylacetidine, Changzhou Qiangli New Materials TR-PAD-101

[0085] C-2: 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, Changzhou Qiangli New Materials TR-HABI-101

[0086] C-3: Tetraethylmirlidone, Changzhou Qiangli New Materials TR-EMK

[0087] C-4: Dibutoxyanthracene, Changzhou Qiangli New Materials TR-PSS-303

[0088] C-5: 1-Phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline

[0089] D-1: Nano zinc oxide, Beijing Deco Island Gold Technology, DK-ZnO-15

[0090] D-2: Carbon black, Tianjin Jindadi Chemical Co., Ltd., SM100

[0091] D-3: 2,2',4,4'-Tetrahydroxybenzophenone, Nanjing Milan Chemical Co., Ltd., BP-2

[0092] D-4: 2-(-hydroxy-3-tert-butyl-5"-methylphenyl)-5-chlorobenzotriazole, Nanjing Milan Chemical Co., Ltd., UV-326

[0093] D-5: Diethylaminohydroxybenzoyl benzoate, Nanjing Milan Chemical Co., Ltd., UV-A PLUS

[0094] F-1: Diamond Green

[0095] F-2: 5-Carboxybenzotriazole

[0096] F-3: Defoamer, Shin-Etsu KS-66 (Japan)

[0097] F-4: Leveling agent, DIGCO FLOW300

[0098] E-1: Fumed silica, Degussa A200

[0099] G-1: Diisobutyl ketone

[0100] G-2: Dipropylene glycol methyl ether

[0101] The process of using ink to create resist patterns for battery cells in this application:

[0102] The prepared photosensitive resist ink was screen printed on a battery cell with a seed layer deposited using a screen printing process with an appropriate mesh size. The ink was then baked in an oven at 95°C for 5-10 minutes to obtain a coating with a thickness of 13-15 micrometers, and its performance was then evaluated.

[0103] Developing conditions: The developer is a 1% sodium carbonate aqueous solution, the developing temperature is 30℃, and the spraying pressure is 1.5 kg / cm2;

[0104] Film stripping conditions: The stripping solution is a 3% sodium hydroxide aqueous solution, the stripping temperature is 50℃, and the spraying pressure is 1.5 kg / cm2;

[0105] Minimum development time determination: Under the above development conditions, dissolve and remove the unexposed resist layer, and the minimum time required for complete dissolution is taken as the minimum development time.

[0106] Exposure: Exposure was performed using an Adtec IP-6 (405nm) exposure machine, and exposure energy was measured using a Stouffer 41-division exposure scale;

[0107] [Sensitivity Evaluation]

[0108] A direct-image exposure machine (Adtec, Japan, trade name "IP-6") using a blue-violet laser diode with a wavelength of 405nm as the light source is used to expose the photosensitive resin composition layer with an energy of 20~70mJ / cm² through a 41-step exposure scale.

[0109] After exposure, development was performed using twice the minimum development time to remove unexposed areas. This resulted in a cured film formed from the cured photosensitive resin layer on the copper surface of the substrate. The energy required to achieve a residual exposure level of 16 (in mJ / cm²) was measured. 2 As a sensitivity evaluation method, the lower the energy required, the better the sensitivity.

[0110] [Resolution Evaluation]:

[0111] Using a wiring pattern with a width of 400:X (X=5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30) with exposed and unexposed portions, exposure was performed at the energy corresponding to the 16th order (41st order exposure scale). After development at twice the minimum development time, the image was observed with a microscope at 50x magnification. The width of the minimum mask gap (the groove formed by removing the unexposed resist) was taken as the resolution value. The lower this value, the better the resolution.

[0112] Evaluation of the remaining anti-corrosion layer

[0113] The resist pattern formed at the above resolution was observed in the portion with a 15 μm wide mask gap (groove) to evaluate the resist shape. Using a scanning electron microscope (SEM), the bottom of the resist groove was observed at 1000x magnification with a 55° tilt angle along the groove direction. The width of the residual foot was measured, and the resist residual foot was evaluated according to the following criteria: if the width of the residual foot is less than 1.0 μm, it is evaluated as "A"; if it is greater than or equal to 1.0 μm and less than 2 μm, it is evaluated as "B"; and if it is greater than or equal to 2 μm, it is evaluated as "C".

[0114] Evaluation of the cross-sectional morphology of the corrosion resist

[0115] The resist cross-sectional shape was evaluated by observing the portion of the resist pattern formed at the resolution described above, specifically the portion with a 15 μm wide mask gap (groove). A scanning electron microscope (SEM) was used to observe the resist shape at 1000x magnification and a 55° tilt angle, and the resist cross-sectional morphology was evaluated according to the following criteria: If the resist formed a groove shape that is narrower at the top and wider at the bottom (i.e., the width of the top edge is less than the width of the bottom edge), it was rated "A"; if the resist formed a groove that is rectangular or narrower at the bottom and wider at the top (i.e., the width of the top edge is greater than or equal to the width of the bottom edge, and the difference is greater than or equal to 0 μm and less than 3 μm), it was rated "B"; and if the resist formed a groove shape that is narrower at the bottom and wider at the top (i.e., the width of the top edge is greater than the width of the bottom edge, and the difference is greater than or equal to 3.0 μm), it was rated "C".

[0116] [Electroplating Resistance Evaluation]

[0117] Exposure and development were performed using a photomask with a line / space ratio of 400 / 15 μm. The solar cells were then immersed in a pre-prepared copper plating solution at a current density of 2 ASD for 15 minutes. After rinsing with water, the cured film was removed from the solar cells, and the appearance of the samples was observed using a 500x high-resolution scanning electron microscope to check for any plating defects.

[0118] Examples 1-17 and Comparative Examples 1-4

[0119] The specific selection, relative weight dosage, and performance evaluation results of each component in Examples 1-17 and Comparative Examples 1-4 are detailed in Table 1.

[0120] Table 1

[0121]

[0122] By comparing Examples 1-17 with Comparative Examples 1-4, it can be found that Examples 1-17 all yielded photosensitive resist inks with excellent comprehensive performance in key aspects such as refractive index, sensitivity, resolution, residual size, and electroplating performance. In Example 16, no ultraviolet absorber was added, and the results showed that the overall comprehensive performance of the corresponding resist was not significantly affected.

[0123] Comparative Examples 1 and 2 used different host resins (A6 and A7), with A7 being a high molecular weight acrylic copolymer resin. The results showed significant deviations in the evaluation of residual resist layers, and the cross-sectional morphology also exhibited varying degrees of deficiencies. Comparative Example 3 used a significantly lower vinyl content than this application, resulting in significantly poor sensitivity and resolution of the resulting resist ink, low evaluation of the resist cross-sectional morphology, and the appearance of plating defects. Although Comparative Example 4 increased the vinyl content, the problems of residual resist layers and cross-sectional morphology in the resulting resist ink were not significantly improved.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A photosensitive resist ink, characterized in that, Its raw materials include: (A) Acrylic copolymer resin; (B) Photopolymerizable compound; said (B) photopolymerizable compound comprises a (meth)acrylate compound having three or more vinyl groups in its molecular structure; (C) Photoinitiator; The photosensitive resist ink contains 0.303 mol to 0.44 mol of vinyl per 100 grams of solids; the acrylic copolymer resin has a molecular weight of 10,000 to 40,000. The (A) acrylic copolymer resin comprises at least one of the copolymer units with the structural formulas shown in (I), (II), and (III); ； ； ； R1, R3, and R5 are each independently selected from any one of hydrogen atoms or methyl groups, and R2, R4, and R6 are each independently selected from any one of hydrogen atoms, alkyl groups, alkoxy groups, aryl groups or substituted aryl groups, hydroxyl groups, or halogen atoms. The (A) acrylic copolymer resin further comprises copolymer units represented by formula (IV), ； R7 is either a hydrogen atom or a methyl group.

2. The photosensitive resist ink according to claim 1, characterized in that, It also includes (D) an ultraviolet absorber, which has the ability to absorb light with wavelengths of 300 to 450 nm.

3. The photosensitive resist ink according to claim 2, characterized in that, The (D) UV absorber is an inorganic UV absorber and / or an organic UV absorber; the inorganic UV absorber is selected from one or more of carbon black, nano-cerium oxide, nano-zinc oxide, and nano-titanium oxide; the organic UV absorber is selected from one or more of benzophenone derivatives, benzoic acid ester derivatives, benzotriazole derivatives, triazine derivatives, or benzoxazine compounds.

4. The photosensitive resist ink according to claim 3, characterized in that, The amount of ultraviolet absorber (D) is 0.04 to 5.1 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

5. The photosensitive resist ink according to claim 4, characterized in that, The amount of ultraviolet absorber (D) is 1 to 3.9 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

6. The photosensitive resist ink according to any one of claims 1-5, characterized in that, The photosensitive resist ink has a refractive index higher than 1.48 at 20°C and a wavelength of 589.3 nm.

7. The photosensitive resist ink according to any one of claims 1-5, characterized in that, The amount of copolymer units shown in formulas (I), (II), and (III) is 1 to 75% of the acrylic copolymer resin in (A).

8. The photosensitive resist ink according to claim 7, characterized in that, The amount of the copolymer unit shown in formula (IV) is 10 to 30% of the total weight of the acrylic copolymer resin in (A).

9. The photosensitive resist ink according to any one of claims 1-5, 8, characterized in that, The (A) acrylic copolymer resin further comprises one or more comonomers selected from methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, hexyl methacrylate, decyl methacrylate, lauryl methacrylate, tetrahydrofuran methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

10. The photosensitive resist ink according to claim 9, characterized in that, The (A) acrylic copolymer resin is selected from one or more of the following: acrylate-phenoxyethyl acrylate-methyl methacrylate-ethyl acrylate, acrylate-styrene-benzyl methacrylate-methyl methacrylate, acrylate-benzyl methacrylate-methyl methacrylate-butyl acrylate, methacrylate-styrene-methyl methacrylate-ethyl acrylate, methacrylate-phenoxyethyl acrylate-styrene-methyl methacrylate-ethyl acrylate, methacrylate-methyl methacrylate-ethyl acrylate, and methacrylate-styrene-methyl methacrylate-ethyl acrylate.

11. The photosensitive resist ink according to claim 9, characterized in that, The weight proportion of acrylic copolymer resin (A) is 49 to 69 parts by weight relative to the total amount of 100 parts by weight of components (A), (B), and (C).

12. The photosensitive resist ink according to claim 11, characterized in that, The weight proportion of acrylic copolymer resin (A) is 50 to 68 parts by weight relative to the total amount of 100 parts by weight of components (A), (B), and (C).

13. The photosensitive resist ink according to any one of claims 1-5, 8, and 10-12, characterized in that, The (meth)acrylate compounds having three or more vinyl groups in their molecular structure are selected from glycerol tri(meth)acrylate, propoxylated glycerol tri(meth)acrylate, ethoxylated glycerol tri(meth)acrylate, tri(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxypropoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tri(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol tri(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, ethoxypropoxylated pentaerythritol tri(meth)acrylate, ethoxypropoxylated pentaerythritol tetra ... Acrylates, dipentaerythritol tri(meth)acrylate, ethoxylated dipentaerythritol tri(meth)acrylate, propoxylated dipentaerythritol tri(meth)acrylate, ethoxylated propoxylated dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, ethoxylated dipentaerythritol tetra(meth)acrylate, propoxylated dipentaerythritol tetra(meth)acrylate, ethoxylated propoxylated dipentaerythritol tetra(meth)acrylate, di One or more of the following: pentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol penta(meth)acrylate, propoxylated dipentaerythritol penta(meth)acrylate, ethoxylated propoxylated dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, and ethoxylated propoxylated dipentaerythritol hexa(meth)acrylate.

14. The photosensitive resist ink according to claim 13, characterized in that, The weight proportion of photopolymerizable compound (B) is 28 to 46 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

15. The photosensitive resist ink according to claim 14, characterized in that, The weight proportion of photopolymerizable compound (B) is 30 to 45 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

16. The photosensitive resist ink according to any one of claims 1-5, 8, 10-12, and 14-15, characterized in that, The photoinitiator (C) is one or more of the following: benzoin ether, benzophenone and its derivatives, thioxanthone compounds, anthraquinone and its derivatives, acridine compounds, thioxanthone compounds, hexaaryl diimidazole compounds, pyrazoline compounds, and anthracene compounds.

17. The photosensitive resist ink according to claim 16, characterized in that, The photoinitiator (C) is a hexaaryl diimidazole compound or an acridine compound.

18. The photosensitive resist ink according to claim 16, characterized in that, The photoinitiator (C) is selected from benzoin ether, benzophenone, thioxanthone, anthraquinone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone, 2-ethylanthraquinone, phenanthraquinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1 4-Naphthoquinone, 9,10-Phenanthroquinone, 2,3-Dimethylanthraquinone, 9-Phenylacetidine, 1,7-(9,9'-Acridinyl)heptane, Benzoin methyl ether, Benzoin ethyl ether, Benzoin phenyl ether, Benzoin dimethyl ketal, Benzoin dimethyl ether, Benzoin ethyl ether, Benzoin propyl ether, Benzoin phenyl ether, Thioxanone, 2-Chlorothioxanone, 4-Chlorothioxanone, 2-Isopropylthioxanone, 4-Isopropylthioxanone, Benzophenone, 4,4'-Bis(dimethylamino)benzophenone (Mischel ketone), 4,4'-Bis(diethylamino)benzophenone, Isopropylthioxanthraquinone, 2-chlorothioxanthraquinone, 2,4-diethylthioxanthraquinone, 2-tert-butylanthraquinone, ethyl N,N-dimethylbenzoate, dimethylaminoethyl benzoate, N,N-dimethylethanolamine, 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazolium One or more of the following: azole dimer, 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline, phenyl-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, and 9,10-di(4-methoxyphenyl)-2-chloroanthracene.

19. The photosensitive resist ink according to claim 17 or 18, characterized in that, The amount of photoinitiator (C) is 0.9 to 8.1 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

20. The photosensitive resist ink according to claim 19, characterized in that, The amount of photoinitiator (C) is 1.4 to 6.9 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

21. The photosensitive resist ink according to any one of claims 1-5, 8, 10-12, 14-15, 17, 18, and 20, characterized in that, The raw materials also include a solvent (G), which is selected from one or more of alcohols, ketones, ethers, aromatic hydrocarbons or esters.

22. The photosensitive resist ink according to claim 21, characterized in that, The alcohols are selected from one or more of diethylene glycol, dipropylene glycol, butanol, or diacetone alcohol; the ketones are selected from one or more of butanone, cyclohexanone, isophorone, diisobutyl ketone, or methyl butyl ketone; the ethers are selected from one or more of ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, diethoxyethanol, dipropylene glycol methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, or tripropylene glycol methyl ether; the aromatic hydrocarbons are selected from one or more of toluene, xylene, or tetramethylbenzene; and the esters are selected from one or more of butyl acetate, butyl lactate, dipropylene glycol methyl ether acetate, or diethylene glycol ethyl ether acetate.

23. The photosensitive resist ink according to claim 22, characterized in that, The amount of solvent (G) is 55 to 175 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

24. The photosensitive resist ink according to claim 23, characterized in that, The amount of solvent (G) is 58 to 166 parts by weight relative to the total amount of 100 parts by weight of components (A), (B) and (C).

25. The photosensitive resist ink according to claim 21, characterized in that, The raw materials also include (E) fumed silica.

26. The photosensitive resist ink according to claim 25, characterized in that, The amount of fumed silica (E) is 0 to 5.1 parts by weight relative to the total amount of components (A), (B), and (C) of 100 parts by weight.

27. The photosensitive resist ink according to claim 26, characterized in that, The amount of fumed silica (E) is 1.5 to 4 parts by weight relative to the total amount of components (A), (B) and (C) of 100 parts by weight.

28. A method for fabricating metal grid lines in photovoltaic cells, characterized in that, include: The photosensitive resist ink according to any one of claims 1-27 is screen printed onto the seed conductor layer of a photovoltaic cell and then dried to obtain a photosensitive resist layer. An exposure process in which active light selectively passes through the photosensitive resist layer to form a photocurable portion; A developing process is performed to remove the photosensitive resist layer other than the photocurable portion, so as to obtain a resist pattern on the photovoltaic cell. The photovoltaic cell with the resist pattern is coated to form a metal grid pattern; the photovoltaic cell with the metal grid pattern is stripped to obtain the metal grid.

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