A photosensitive composition, a method for forming a mask pattern, and a battery cell

Abstract

This invention discloses a photosensitive composition, a method for forming a mask pattern, and a battery cell. The photosensitive composition comprises: 35-70 parts of photosensitive resin; 5-15 parts of photoinitiator; 5-20 parts of photopolymerizable monomer; 5-30 parts of solvent; 1-10 parts of predetermined solid particles; and 0.1-5 parts of additives. The photosensitive composition of this invention can form grid lines with a width gradient and has good wear resistance and electroplating resistance.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic materials, and in particular to a photosensitive composition, a mask pattern, and a method for forming it. Background Technology

[0002] Chinese patent document CN217361599U discloses a patent entitled "A Grid Line and a Photovoltaic Cell with the Grid Line". The patent points out that a grid line with a width gradient (narrower at the top and wider at the bottom) can be formed on the surface of the cell by copper electroplating, such as a grid line with a trapezoidal cross section. After the grid line with the width gradient is encapsulated in the photovoltaic module, it has the function of reflecting incident light at multiple angles. This reflection can be reflected back to the surface of the cell at the material interface inside the photovoltaic module, thereby increasing the power generation efficiency.

[0003] How to easily form the grid lines of the above structure is a problem to be solved. Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, the purpose of the present invention is to provide a photosensitive composition, a mask pattern forming method and a battery cell, which can form trapezoidal mask openings, form grid lines with a width gradient (narrower at the top and wider at the bottom), and have good wear resistance and electroplating resistance.

[0005] To address the above problems, a first aspect of the present invention provides a photosensitizing composition, the photosensitizing composition comprising:

[0006] 35–70 parts of photosensitive resin;

[0007] 5-15 parts of photoinitiator;

[0008] 5-20 parts of photopolymerizable monomer;

[0009] 5-30 parts solvent;

[0010] 1 to 10 parts of the pre-ordered solid granules;

[0011] 0.1 to 5 parts of adjuvant,

[0012] The predetermined solid particles include one or more of insoluble solid particles, slightly soluble solid particles, and sparingly soluble solid particles, and the particle size of the predetermined solid particles is between 100 nm and 2 μm. The additives are selected from one or more of defoamers, leveling agents, and tack removers.

[0013] Further, the photoinitiator is 10-15 parts, the photopolymerizable monomer is 10-20 parts, and the predetermined solid particles are 4-10 parts.

[0014] Furthermore, the insoluble solid particles are selected from one or more of silica particles, calcium carbonate particles, barium sulfate particles, pigment particles, and carbon black particles, and the slightly soluble solid particles and the sparingly soluble solid particles are selected from one or more of solid photosensitive resin particles, epoxy resin particles, calcium hydroxide particles, and iron hydroxide particles.

[0015] Furthermore, the insoluble solid particles are 6 to 10 parts in number and are composed of silicon dioxide and carbon black particles, and the ratio of silicon dioxide to carbon black particles is 2:3 to 3:2.

[0016] Furthermore, the solvent is 10 to 20 parts, and the particle size of the predetermined solid particles is 1 nm to 2 μm.

[0017] Furthermore, the solvent is 18 to 30 parts, and the particle size of the predetermined solid particles is 500 nm to 1 μm.

[0018] Furthermore, the photosensitive resin includes a carboxylated resin polymer and an epoxy acrylate resin.

[0019] Furthermore, the carboxylated resin polymer is selected from one or more of carboxylated polyurethane and carboxylated polyimide resins, and the epoxy acrylate resin is selected from one or more of carboxylic acid modified bisphenol A type epoxy resin, carboxylic acid modified bisphenol F type epoxy resin, carboxylic acid modified phenolic epoxy resin, and carboxylic acid modified o-cresol phenolic epoxy resin.

[0020] Further, the photoinitiator is selected from trichloroacetophenone, p-tert-butylacetophenone, benzophenone, 2-chlorobenzophenone, p,p'-bis(dimethylamino)benzophenone, benzoin, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-(o-fluorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, 2,4,5-triarylbiimidazole, 2-trichloromethyl-5-styryl-1,3-oxadiazole, 2-trichloromethyl-5-(p-cyano)- The photopolymerizable monomer is selected from one or more of the following: 1,3,4-oxadiazole (-1,3,4-(2 ...

[0021] Further, the solvent is selected from one or more of methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, acetone, methyl ethyl ketone, cyclohexanone, N-methyl-2-pyrrolidone, toluene, xylene, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, and benzoguanamine.

[0022] A second aspect of the present invention provides a method for forming a mask pattern for a battery cell, the method comprising:

[0023] Step S1: Deposit the photosensitive composition described in any one of the above-mentioned methods on the surface of the solar cell to form a mask;

[0024] Step S2: Place the mask plate above the mask and apply a light source to the mask plate to expose the mask;

[0025] Step S3: Develop the mask to form a mask opening on the mask.

[0026] A third aspect of the present invention provides a battery cell on the surface of which the photosensitive composition described in any one of the preceding claims is deposited.

[0027] Due to the above technical solution, the present invention has the following beneficial effects:

[0028] The photosensitive composition according to embodiments of the present invention has high photosensitivity and relatively low density. The predetermined solid particles can sink to form a light-blocking gradient (less light blocking at the top and more light blocking at the bottom), thereby forming a trapezoidal mask opening after exposure and development. Trapezoidal grid lines can then be formed in this mask opening. Moreover, the mask containing the predetermined solid particles can effectively prevent the penetration of electroplating solution during subsequent electroplating processes, avoiding the formation of a metal layer in non-grid lines. Furthermore, the mask containing the predetermined solid particles can improve the structural stability and wear resistance of the mask, effectively preventing the mask from being corroded and worn. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0030] Figure 1 This is a schematic diagram of mask exposure according to an embodiment of the present invention;

[0031] Figure 2This is a schematic diagram of a battery cell covered with a mask according to an embodiment of the present invention;

[0032] Figure 3 It is based on Figure 2 Microscopic images of the embodiments;

[0033] Figure 4 Is Figure 2 A structural diagram of the grid lines formed within the mask in the embodiment;

[0034] Figure 5 This is a schematic diagram of a masked battery cell after development, according to a comparative example of the present invention.

[0035] Figure 6 It is based on Figure 5 Comparative microscope images;

[0036] Figure 7 Is Figure 5 A structural diagram of the grid lines formed within a comparative mask.

[0037] 100, Mask plate; 200, Wet film; 310, First dry film; 320, Second dry film; 410, First mask opening; 420, Second mask opening; 510, First grid line; 520, Second grid line; 600, Light source; 700, Solar cell. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] To achieve a gate line with a width gradient (narrower at the top and wider at the bottom), the present invention forms a dry film (a mask in a cured state) with a trapezoidal mask opening, and then electroplats the gate line within the mask opening to form a gate line with a width gradient (narrower at the top and wider at the bottom).

[0040] To achieve a trapezoidal mask opening, a photosensitive composition is first coated on the surface of the solar cell to form a wet film (an uncured mask). A photosensitive gradient is formed on the wet film (the upper part cures quickly, while the lower part is difficult to cure and has a slow curing rate). During exposure through the mask, the upper part of the wet film in the light-transmitting area of ​​the mask cures rapidly under light, while the lower part is not fully cured. During development, the wet film in the upper light-transmitting area is transformed into a dry film due to curing, while the wet film in the lower light-transmitting area is not fully cured. Due to the impact of the developer and the adhesion of the wet film in the non-light-transmitting area, peeling occurs, thus forming a trapezoidal mask opening.

[0041] This invention utilizes the sinking and distribution of insoluble solid particles in other components with relatively low density, forming a distribution gradient with fewer particles at the top and more at the bottom. This distribution gradient corresponds to a light-shielding gradient. Alternatively, it utilizes the sinking and partial dissolution of microsoluble and / or sparingly soluble solid particles in other components with relatively low density, creating a concentration gradient. This concentration gradient corresponds to a light-shielding gradient, thereby forming a photosensitive gradient in the wet film (more light received at the top, easier to cure, less light received at the bottom, less easy to cure). This results in the formation of trapezoidal mask openings after exposure and development, allowing the formation of trapezoidal grid lines within these mask openings.

[0042] The photosensitizing composition of embodiments of the present invention will now be described.

[0043] In some embodiments of the present invention, the following components are included: 35-70 parts photosensitive resin; 5-15 parts photoinitiator; 5-20 parts photopolymerizable monomer; 5-30 parts solvent; 1-10 parts predetermined solid particles; and 0.1-5 parts additives. The predetermined solid particles include one or more of insoluble solid particles, slightly soluble solid particles, and sparingly soluble solid particles, and the particle size of the predetermined solid particles is between 100 nm and 2 μm. The additives are selected from one or more of defoamers, leveling agents, and tackifiers.

[0044] The aforementioned photosensitive resin can be in quantities of 35 parts, 36 parts, 38 parts, 47 parts, 53 parts, 65 parts, 68 parts, 70 parts, etc. The aforementioned photoinitiator can be in quantities of 5 parts, 7 parts, 9 parts, 13 parts, 15 parts, etc. The aforementioned photopolymerizable monomer can be in quantities of 5 parts, 7 parts, 9 parts, 12 parts, 15 parts, 18 parts, 20 parts, etc. The aforementioned solvent can be in quantities of 5 parts, 9 parts, 11 parts, 13 parts, 18 parts, 24 parts, 26 parts, 30 parts, etc. The aforementioned predetermined solid particles can be in quantities of 1 part, 5 parts, 8 parts, 10 parts, etc. The aforementioned additives can be in quantities of 0.1 parts, 0.6 parts, 0.9 parts, 1.5 parts, 2 parts, etc. Specifically, those skilled in the art can select the weight parts of each component within the range of each component according to the actual situation, which will not be elaborated here.

[0045] The present invention uses 5 to 15 parts of photoinitiator, which can improve the overall photosensitivity of the photosensitive composition. High photosensitivity means that the photosensitive composition cures faster, and a small amount of light can cure it quickly.

[0046] The present invention uses 5 to 30 parts of solvent, which can reduce the density of the photosensitive composition, making it easier for the predetermined solid particles to settle in a component of this density.

[0047] This invention uses 1 to 10 parts of predetermined solid particles, the particle size of which is 100 nm to 2 μm. Because these predetermined solid particles are insoluble, slightly soluble, or sparingly soluble in other components, their distribution in the other components is not uniform. The predetermined solid particles with a particle size of 100 nm to 2 μm can settle in the other components and have a predetermined settling velocity. This avoids excessively high settling velocities, which would cause all the predetermined solid particles to accumulate at the bottom of the wet film, and also avoids excessively low settling velocities, which would prevent the formation of a distribution gradient with fewer particles at the top and more at the bottom.

[0048] If relatively large-diameter insoluble solid particles are stacked, they have a high stacking height, which makes it easier to form a light-blocking gradient. Larger-diameter microsoluble solid particles and sparingly soluble solid particles dissolve continuously during settling, which facilitates the formation of a concentration gradient.

[0049] This invention uses 0.1 to 5 parts of an additive, selected from one or more of defoamers, leveling agents, and tackifiers. The defoamer eliminates air bubbles in the composition, preventing them from affecting the density of the photosensitive composition. The leveling agent improves the smoothness of the composition during deposition on the battery cell, reduces the tension of the photosensitive resin, and reduces the resistance to the settling of the predetermined solid particles, making the predetermined solid particles settle more easily. The tackifier reduces the viscosity of the photosensitive resin, reduces the resistance to the settling of the predetermined solid particles, and facilitates the settling of the predetermined solid particles.

[0050] The above-mentioned photosensitive composition has high photosensitivity and relatively low density. The predetermined solid particles can sink to form a light-blocking gradient (less light blocking at the top and more light blocking at the bottom), thereby forming a trapezoidal mask opening after exposure and development. Trapezoidal grid lines can then be formed in this mask opening. Moreover, the mask containing the predetermined solid particles can effectively prevent the penetration of electroplating solution during subsequent electroplating processes, avoiding the formation of a metal layer in non-grid lines. Furthermore, the mask containing the predetermined solid particles can improve the structural stability and wear resistance of the mask, effectively preventing the mask from being corroded and worn.

[0051] In some embodiments of the present invention, the photoinitiator is 10-15 parts, the photopolymerizable monomer is 10-20 parts, and the predetermined solid particles are 4-10 parts.

[0052] The combination of 10-15 parts of photoinitiator and 10-20 parts of photopolymerizable monomer can significantly increase photosensitivity, allowing the wet film to cure quickly. 4-10 parts of predetermined solid particles can form a larger shading gradient, thereby creating a larger photosensitivity gradient.

[0053] In some embodiments of the present invention, the insoluble solid particles are selected from one or more of silica particles, calcium carbonate particles, barium sulfate particles, pigment particles, and carbon black particles, and the slightly soluble solid particles and sparingly soluble solid particles are selected from one or more of solid photosensitive resin particles, epoxy resin particles, calcium hydroxide particles, and iron hydroxide particles.

[0054] The light transmittance of the above insoluble solid particles is as follows: silica particles > (calcium carbonate particles, barium sulfate particles, pigment particles) > carbon black particles. The choice can be made based on the required shading gradient. Carbon black particles are preferred if a large shading gradient is needed, while silica particles are preferred if a small shading gradient is required.

[0055] In some embodiments of the present invention, the insoluble solid particles are 6 to 10 parts, and are composed of silicon dioxide and carbon black particles, and the ratio of silicon dioxide to carbon black particles is 2:3 to 3:2.

[0056] Silica particles (transparent) have relatively high light transmittance, while carbon black particles (black) have relatively low light transmittance. During the settling process of silica and carbon black particles, they can stack together. The silica particles can block excessive carbon black particles from settling, thus preventing the bottom layer of the wet film from having too low light transmittance and causing the bottom layer of the wet film to fail to cure as a whole.

[0057] When the ratio of silica to carbon black particles is 2:3 to 3:2, a relatively stable shading gradient can be achieved with small fluctuations.

[0058] In some embodiments of the present invention, the solvent is 10 to 20 parts, and the particle size of the predetermined solid particles is 1 to 2 μm.

[0059] When the solvent content is 10 to 20 parts, the density is relatively high, making it more suitable for insoluble solid particles of 1 to 2 μm. The solid particles can sink at a predetermined speed in the wet film state, thereby forming a light-blocking gradient.

[0060] Optionally, the solvent is 18 to 30 parts, and the particle size of the insoluble solid particles is 500 nm to 1 μm.

[0061] When the solvent content is 18 to 30 parts, the density is relatively low, making it more suitable for predetermined solid particles of 500 to 1 μm. The predetermined solid particles can sink at a predetermined speed in the wet film state, thereby forming a light-blocking gradient.

[0062] In some embodiments of the present invention, the photosensitive resin includes a carboxylated resin polymer and an epoxy acrylate resin.

[0063] Optionally, the carboxylated resin polymer is selected from one or more of carboxylated polyurethane and carboxylated polyimide resins, and the epoxy acrylic resin is selected from one or more of carboxylic acid modified bisphenol A type epoxy resin, carboxylic acid modified bisphenol F type epoxy resin, carboxylic acid modified phenolic epoxy resin, and carboxylic acid modified o-cresol phenolic epoxy resin.

[0064] In some embodiments of the present invention, the photoinitiator is selected from trichloroacetophenone, p-tert-butylacetophenone, benzophenone, 2-chlorobenzophenone, p,p'-bis(dimethylamino)benzophenone, benzoin, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-(o-fluorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, 2,4,5-triarylbiimidazole, 2-trichloromethyl-5-styryl-1,3,-oxadiazole, 2-trichloromethyl-5-( One or more of (-cyanostylenyl)-1,3,4-oxadiazole; the photopolymerizable monomer is selected from one or more of neopentyl glycol di(meth)acrylate, dicyclopentyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, isocyanurate, di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, and propionic acid-modified pentaerythritol penta(meth)acrylate.

[0065] In some embodiments of the present invention, the solvent is selected from one or more of methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, acetone, methyl ethyl ketone, cyclohexanone, N-methyl-2-pyrrolidone, toluene, xylene, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, and benzoguanamine.

[0066] The beneficial effects of this application will be explained below with reference to specific embodiments and comparative examples.

[0067] Table 1 Test results of the photosensitive compositions in the examples

[0068]

[0069] Note 1: Photosensitive resins include: carboxylated resin polymers (polyimide resin, PI-380G, Jin Yi Chemical) and epoxy acrylate resins (ZFR-1491H, Nippon Kayaku).

[0070] Note 2: Photoinitiator, Irgacure 907, Ciba.

[0071] Note 3: Photopolymerizable monomer, EM265, Changxing Chemical

[0072] Note 4: Solvent, triethylene glycol monoethyl ether, Kaiyin Chemical Co., Ltd.

[0073] Note 5: Additives, leveling agents, AKN-1032, Qianyou Chemical.

[0074] Note 6: Insoluble solid particles, carbon black, particle size 1µm, from Youmeng Chemical.

[0075] Example 1

[0076] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 28 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0077] Next, add 5 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0078] Finally, add 1 part of insoluble solid particles (carbon black, 1 μm particle size, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0079] Example 2

[0080] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 24 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0081] Next, add 5 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0082] Finally, add 5 parts of insoluble solid particles (carbon black, 1µm particle size, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0083] Example 3

[0084] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 19 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0085] Next, add 5 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0086] Finally, add 10 parts of insoluble solid particles (carbon black, particle size 1µm, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0087] Example 4

[0088] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 23 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0089] Next, add 10 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0090] Finally, add 1 part of insoluble solid particles (carbon black, 1 μm particle size, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0091] Example 5

[0092] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 19 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0093] Next, add 10 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0094] Finally, add 5 parts of insoluble solid particles (carbon black, 1µm particle size, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0095] Example 6

[0096] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 14 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0097] Next, add 10 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0098] Finally, add 10 parts of insoluble solid particles (carbon black, particle size 1µm, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0099] Example 7

[0100] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 18 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0101] Next, add 15 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0102] Finally, add 1 part of insoluble solid particles (carbon black, 1 μm particle size, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0103] Example 8

[0104] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 14 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0105] Next, add 15 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0106] Finally, add 5 parts of insoluble solid particles (carbon black, 1µm particle size, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0107] Example 9

[0108] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 9 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0109] Next, add 15 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0110] Finally, add 10 parts of insoluble solid particles (carbon black, particle size 1µm, Yumeng Chemical) while stirring at 2000 rpm. After the addition is complete, continue stirring and dispersing for 30 minutes.

[0111] Comparative Example 1

[0112] First, 50 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 25 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 5 parts of photopolymerizable monomer (EM265, Changxing Chemical) and 15 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0113] Next, add 5 parts of photoinitiator (Irgacure 907, Ciba) and disperse using a disperser at 1300 rpm for 10 minutes.

[0114] Comparative Example 2

[0115] First, 35 parts of polyimide resin (polyimide resin, PI-380G, Jin Yi Chemical), 15 parts of epoxy acrylate resin (ZFR-1491H, Nippon Kayaku), 15 parts of photopolymerizable monomer (EM265, Changxing Chemical), 1 part of additive (leveling agent, AKN-1032, Qianyou Chemical) and 19 parts of solvent (triethylene glycol monoethyl ether, Kaiyin Chemical) were dispersed in a disperser at a speed of 1300 rpm for 20 minutes.

[0116] Next, add 15 parts of photoinitiator (Irgacure 907, Ciba) and disperse it using a disperser at 1300 rpm for 10 minutes.

[0117] like Figure 1 As shown, the photosensitive compositions of various embodiments and comparative examples are deposited on a solar cell to form a mask (wet film 200). A mask plate 100 is placed above the mask, and a light source is applied to the mask (wet film 200) to expose the mask. The mask is developed to form mask openings on the mask.

[0118] Example 5 Formation Figure 2 The first dry film 310 and the first mask opening 410 in Comparative Example 1 are formed Figure 6 The second dry film 320 and the second mask opening 420 are formed. Electroplating is performed at the first mask opening 410 to form... Figure 4 The first gate line in the middle is electroplated at the opening 420 of the second mask to form Figure 7 The second grid line in the middle.

[0119] After forming the mask opening, measure the bottom angle of the mask opening (the angle between the sidewall of the mask at the opening and the surface of the solar cell), such as... Figure 2 The bottom angle R and the embodiment shown Figure 5 The base angle T shown is comparable to that of the mask, and the mask is observed under a microscope. Figure 3 The mask structure of the embodiment shown is as follows: Figure 6 The comparative mask structure shown is formed by electroplating on the basis of the solar cell mask to form grid lines, such as... Figure 4 The gate lines of the illustrated embodiment, such as Figure 7 The grid lines shown are a comparative example.

[0120] After the mask opening is formed, the mask is rubbed with 500-grit sandpaper. The weight of the battery cell covering the mask before and after rubbing is measured, and the weight loss ratio is calculated.

[0121] Weight loss ratio = (weight of the cell before friction with the mask covering - weight of the cell before friction with the mask covering) ÷ weight of the cell before friction with the mask covering.

[0122] After the mask is cured and before the mask is opened, the battery cell covered with the mask is placed in the electroplating solution for 48 hours for electroplating. The battery cell covered with the mask is then removed, and the mask is removed by development. The area of ​​electroplating on the surface of the battery cell is observed and measured by two-dimensional measurement, and the penetration ratio is calculated.

[0123] Penetration ratio = (Area of ​​electroplating on the surface of the solar cell / Area of ​​the solar cell ÷ Area of ​​the solar cell)

[0124] Finally, the test results are shown in Table 2.

[0125] Table 2 shows the test results from the embodiments.

[0126]

[0127] From the above description, it can be seen that as the weight percentages of the predetermined solid particles, photoinitiator, and photopolymerizable monomers increase, the angle of the base corner becomes smaller and the electroplating resistance improves. The wear resistance is mainly affected by the weight percentage of the predetermined solid particles, with relatively weak correlation to other components.

[0128] The above embodiments of the present invention achieve the following technical effects:

[0129] The photosensitive composition of this invention can form trapezoidal mask openings, form grid lines with a width gradient (narrower at the top and wider at the bottom), and has good abrasion resistance and electroplating resistance.

[0130] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photosensitive composition, characterized by comprising: The photosensitive composition consists of the following ingredients in parts by weight: 35~70 parts of photosensitive resin; 5~15 parts of photoinitiator; 5~20 parts of photopolymerizable monomer; 5~30 parts of solvent; 1~10 parts of predetermined solid particles; 0.1~5 parts of auxiliary agent, The predetermined solid particles include one or more of insoluble solid particles, slightly soluble solid particles and hardly soluble solid particles, the particle size of the predetermined solid particles is between 100 nm and 2 um, and the auxiliary agent is selected from one or more of defoaming agent, leveling agent and adhesion remover; The predetermined solid particles form a distribution gradient and then form a light-shielding gradient by sinking.

2. The photosensitive composition according to claim 1, characterized by The photoinitiator is 10~15 parts, the photopolymerizable monomer is 10~20 parts, and the predetermined solid particles are 4~10 parts.

3. The photosensitive composition according to claim 1, characterized by The insoluble solid particles are selected from one or more of silica particles, calcium carbonate particles, barium sulfate particles, pigment particles and carbon black particles, and the slightly soluble solid particles and the hardly soluble solid particles are selected from one or more of solid photosensitive resin particles, epoxy resin particles, calcium hydroxide particles and iron hydroxide particles.

4. The photosensitive composition according to claim 3, wherein The insoluble solid particles are 6~10 parts and consist of silica and carbon black particles, and the ratio of the silica to the carbon black particles is 2:3~3:

2.

5. The photosensitive composition according to claim 1, characterized by The solvent is 10~20 parts, and the particle size of the predetermined solid particles is 1 nm~2 um.

6. The photosensitive composition according to claim 5, characterized by The solvent is 18~30 parts, and the particle size of the predetermined solid particles is 500 nm~1 um.

7. The photosensitive composition according to claim 1, wherein The photosensitive resin includes carboxylated resin polymer and epoxy acrylate resin.

8. The photosensitive composition according to claim 7, characterized by The carboxylated resin polymer is selected from one or more of carboxylated polyurethane and carboxylated polyimide resin, and the epoxy acrylate resin is selected from one or more of carboxylic acid modified bisphenol A type epoxy resin, carboxylic acid modified bisphenol F type epoxy resin, carboxylic acid modified phenolic epoxy resin and carboxylic acid modified o-cresylic epoxy resin.

9. The photosensitive composition according to claim 1, characterized by The photoinitiator is selected from one or more of trichloroacetophenone, p-t-butylacetophenone, benzophenone, 2-chlorobenzophenone, p,p'-bis(dimethylamino)benzophenone, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-(o-fluorophenyl)-4,5-diphenyl imidazole, 2-(o-methoxyphenyl)-4,5-diphenyl imidazole, 2,4,5-triaryl imidazole, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole and 2-trichloromethyl-5-(p-cyanostyryl)-1,3,4-oxadiazole; and the photopolymerizable monomer is selected from one or more of hydroxyneopentyl glycol di(meth)acrylate, dicyclopentyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, isocyanurate, di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate and propionic acid-modified dipentaerythritol penta(meth)acrylate.

10. The photosensitive composition according to claim 1, characterized by The solvent is selected from one or more of methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, acetone, methyl ethyl ketone, cyclohexanone, N-methyl-2-pyrrolidone, toluene, xylene, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, and benzoguanamine.

11. A method for forming a mask pattern for a battery cell, characterized in that, The method comprises: Step S1, depositing the photosensitive composition according to any one of claims 1-10 on the surface of a solar cell to form a mask; Step S2, placing a mask plate above the mask, applying a light source on the mask plate to expose the mask; Step S3, developing the mask to form a mask opening on the mask.

12. A battery sheet, characterized by The surface of the cell is deposited with the photosensitive composition according to any one of claims 1-10.

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