Electroplating resist composition and dry film thereof

Abstract

Provided are a plating resist composition and a dry film thereof that exhibit excellent plating resistance even without an inorganic filler and can reduce exposure and development residues and cell surface scratches. The plating resist composition comprises (A) a multifunctional acrylic resin, (B) a multifunctional acrylic monomer, and (C) a polyamine, and does not contain an inorganic filler. The multifunctional acrylic monomer (B) accounts for 1 to 30% by mass relative to the total mass of the (A) multifunctional acrylic resin, (B) multifunctional acrylic monomer, and (C) polyamine.

Description

Technical Field

[0001] The present invention relates to an anti-electroplating composition, in particular to an anti-electroplating composition used in manufacturing electrodes of solar cells, and a dry film thereof, belonging to the field of anti-electroplating materials used in manufacturing solar cells. Background Art

[0002] Globally, energy and environmental issues are receiving increasing attention, and the use of new energy sources such as solar energy is being actively promoted. Solar cells are devices that directly convert light energy into electrical energy through the photoelectric or photochemical effects. Currently, crystalline silicon solar cells that operate using the photovoltaic effect are the mainstream and have been applied in many fields, including transportation, communications, meteorology, satellites, lighting, and power stations.

[0003] A wide range of research and development efforts have been actively conducted on solar cell electrodes, core components of solar cells, and their manufacturing methods. For example, Patent Document 1 discloses a method for printing photovoltaic electrodes of various shapes, comprising the following steps: Step 1: spin-coating a layer of photoresist on the surface of a cell; Step 2: placing the cell in a UV exposure machine equipped with a specific patterned photomask and irradiating it with UV light; Step 3: placing the cell in a developer for development to expose the cell substrate, thereby producing a patterned cell; Step 4: spin-coating a layer of solar slurry on the surface of the patterned cell; Step 5: soaking the cell in an organic solvent to remove the photoresist; and Step 6: sintering the cell to produce photovoltaic electrodes of various shapes.

[0004] To further reduce costs and increase efficiency of solar cells, the use of electroplating to produce metal electrodes for solar cells has also attracted much attention. This method primarily replaces expensive silver partially or completely with lower-cost metals such as copper and nickel. When using electroplating to produce electrodes, it is necessary to define the position and size of the metal electrodes on the surface of the solar cell using a patterned mask, and use photoresist to perform the mask opening process. For example, Patent Document 2 discloses a method for producing photovoltaic cell electrodes, comprising the following steps: depositing a liquid mask material containing a photosensitive component onto the surface of a photovoltaic device having a dielectric layer, a transparent conductive oxide, or a conductive seed layer; exposing a portion of the mask material to a laser; developing to remove the mask material from the surface of the photovoltaic device in the unexposed area, exposing the dielectric layer, the transparent conductive oxide, or the conductive seed layer, thereby forming a local opening in the mask material; etching the dielectric layer to expose the semiconductor layer at the opening, and then attaching a conductive material to the semiconductor surface at the opening by electrochemical deposition; or attaching a conductive material to the partially opened photovoltaic device surface by electrochemical deposition on the opened transparent conductive oxide or conductive seed layer; and removing the mask material from the surface.

[0005] The photoresist (also known as plating-resistant ink) used in this method typically contains a photosensitizer, a sensitizer, a solvent, and additives. For example, Patent Document 3 discloses a photovoltaic LDI photoresist containing a hyperbranched polymer with a specific structure, a reactive diluent, a photoinitiator, a functional additive, and a nanofiller in specific amounts. The nanofiller can be at least one of SiO2, TiO2, ZrO2, ZnO, MgO, CaO, Al2O3, K2CO3, BaSO4, CaCO3, talc, montmorillonite, zeolite, mica powder, graphene, fullerene, and carbon nanotubes.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: CN105762203A

[0009] Patent Document 2: CN112993087A

[0010] Patent Document 3: CN114835889A Summary of the Invention

[0011] Problems to be solved by the invention

[0012] However, the photoresist used in the past to manufacture solar cell electrodes has the following problems: it is easy to scratch the cell and leaves a lot of residue after exposure and development, which in turn reduces the photoelectric conversion efficiency of the cell.

[0013] The inventors of the present invention have discovered through research that the cause of the above-mentioned problem is that the previous photoresist contains inorganic fillers. When the photoresist is applied to the surface of the battery cell formed into a pyramid-shaped velvet surface, the inorganic fillers easily enter the depressions on the surface of the battery cell, and move during the subsequent curing, exposure, and development processes to scratch the surface of the battery cell. In addition, the inorganic fillers sometimes remain together with the resin component of the photoresist, which becomes one of the reasons for the increase in exposure and development residues.

[0014] On the other hand, the inventors of the present invention have also discovered that, when the inorganic filler is removed from the conventional photoresist in order to solve the above-mentioned problem, a problem of poor plating resistance occurs.

[0015] Therefore, there is an urgent need to develop a photoresist that has excellent developability (ie, little exposure and development residue) while meeting the requirements of anti-plating performance and does not scratch the surface of the battery cell.

[0016] In view of the above, an object of the present invention is to provide an anti-plating composition and a dry film thereof that have excellent anti-plating performance even without an inorganic filler and can reduce exposure and development residues and scratches on the cell surface.

[0017] Solutions for solving problems

[0018] The present inventors conducted intensive research and discovered that by simultaneously including a multifunctional acrylic monomer and a polyamine in a plating-resistant composition containing a multifunctional acrylic resin and no inorganic filler, and by controlling the content of the multifunctional acrylic monomer to be within a specific range, the plating-resistant composition can fully meet the requirements of plating resistance, developability, and surface scratch resistance, thereby completing the present invention.

[0019] That is, the present invention is as follows.

[0020] 1. A plating resist composition comprising (A) a multifunctional acrylic resin, (B) a multifunctional acrylic monomer, and (C) a polyamine, and containing no inorganic filler, wherein the amount of the (B) multifunctional acrylic monomer is 1 to 30% by mass relative to the total mass of the (A) multifunctional acrylic resin, (B) multifunctional acrylic monomer, and (C) polyamine.

[0021] 2. The plating resist composition according to item 1, wherein the polyfunctional acrylic resin (A) has a plurality of carboxyl groups in addition to a plurality of (meth)acryloyl groups.

[0022] 3. The plating resist composition according to claim 1 or 2, wherein the multifunctional acrylic resin (A) comprises an epoxy-modified acrylic resin.

[0023] The epoxy-modified acrylic resin is a resin obtained by reacting a multifunctional epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride to the hydroxyl groups present in the side chain; or a resin obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups to the resin.

[0024] 4. The plating-resistant composition according to claim 3, wherein the multifunctional epoxy resin is a resin obtained by reacting a phenol novolac-type epoxy resin or a cresol novolac-type epoxy resin with (meth)acrylic acid and adding tetrahydrophthalic anhydride to the hydroxyl groups present in the side chains; or a resin obtained by further adding glycidyl (meth)acrylate to the resin.

[0025] 5. The plating resist composition according to item 1 or 2, wherein the amount of the polyfunctional acrylic resin (A) is 28 to 98% by mass relative to the total mass of the polyfunctional acrylic resin, the polyfunctional acrylic monomer (B) and the polyamine (C).

[0026] 6. The plating resist composition according to 1 or 2, wherein the (B) multifunctional acrylic monomer comprises a tetrafunctional or higher-functional acrylic monomer.

[0027] 7. The plating resist composition according to 1 or 2, wherein the (C) polyamine contains a polyamine having a triazine structure in the molecule.

[0028] 8. The plating resist composition according to item 7, wherein the polyamine having a triazine structure in its molecule is melamine.

[0029] 9. The plating resist composition according to item 1 or 2, wherein the polyamine (C) accounts for 0.2 to 10% by mass relative to the total mass of the polyfunctional acrylic resin (A), the polyfunctional acrylic monomer (B) and the polyamine (C).

[0030] 10. Use of the plating resist composition according to any one of 1 to 9 above for producing an electrode for a solar cell.

[0031] 11. A dry film, characterized in that it is obtained by applying the plating resist composition according to any one of 1 to 9 above on a carrier film and drying the coating.

[0032] Effects of the Invention

[0033] According to the present invention, an anti-plating composition and a dry film thereof can be provided, which have excellent anti-plating performance even without an inorganic filler and can reduce exposure and development residues and scratches on the surface of a cell. DETAILED DESCRIPTION

[0034] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or preferred over other embodiments.

[0035] In addition, numerous specific details are provided in the following detailed description to better illustrate the present invention. Those skilled in the art will appreciate that the present invention can be practiced without certain specific details. In other instances, methods, means, equipment, and steps well known to those skilled in the art are not described in detail in order to highlight the main points of the present invention.

[0036] Unless otherwise stated, the units used in this specification are international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0037] In this specification, the use of "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0038] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "embodiments," etc., mean that the specific elements (e.g., features, structures, properties, and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0039] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0040] In this specification, (meth)acrylic acid is a term that collectively refers to acrylic acid, methacrylic acid, and a mixture thereof, and the same applies to other similar expressions.

[0041] The present invention provides a plating resist composition, characterized in that it comprises (A) a multifunctional acrylic resin, (B) a multifunctional acrylic monomer, and (C) a polyamine, and does not contain an inorganic filler, wherein the amount of the (B) multifunctional acrylic monomer is 1 to 30% by mass relative to the total mass of the (A) multifunctional acrylic resin, the (B) multifunctional acrylic monomer, and the (C) polyamine.

[0042] Hereinafter, each component of the plating resist composition of the present invention will be described in detail.

[0043] (A) Multifunctional acrylic resin

[0044] The (A) multifunctional acrylic resin contained in the plating resist composition of the present invention is a resin having a plurality of (meth)acryloyl groups in its molecule, and is a component that cures by polymerization and / or crosslinking via the ethylenically unsaturated double bonds of the (meth)acryloyl groups upon irradiation with light.

[0045] The polyfunctional acrylic resin (A) is not particularly limited, and examples thereof include resins having multiple (meth)acryloyl groups in the molecule obtained by acrylic acid-modifying epoxy resins, phenolic resins, polycarbonate resins, polyether resins, polyester resins, polyolefin resins, and polyurethane resins.

[0046] In addition, from the perspective of imparting alkali developability, it is preferred that the molecule contain multiple carboxyl groups in addition to multiple (meth)acryloyl groups. From the perspective of further improving plating resistance and reducing development residue, the double bond equivalent of the multifunctional acrylic resin (A) is preferably 220 to 410 g / eq, more preferably 250 to 390 g / eq, and even more preferably 270 to 320 g / eq. From the perspective of alkali developability and resolution, the acid value of the multifunctional acrylic resin (A) is preferably 5 to 100 mgKOH / g, more preferably 10 to 90 mgKOH / g, and even more preferably 20 to 80 mgKOH / g.

[0047] From the perspective of achieving the effects of the present invention, such as excellent plating resistance even without the presence of inorganic fillers, less exposure and development residue, and preventing scratches on the surface of the cell, epoxy-modified acrylic resins are preferred. Epoxy-modified acrylic resins typically include resins obtained by reacting a multifunctional epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride to the hydroxyl groups present in the side chain; and resins obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in the molecule to the resin. Examples of the compound having one epoxy group and one or more (meth)acryloyl groups include glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl methacrylate.

[0048] Examples of polyfunctional epoxy resins useful for synthesizing epoxy-modified acrylic resins include bisphenol A epoxy resins, bisphenol F epoxy resins, hydrogenated bisphenol A epoxy resins, brominated bisphenol A epoxy resins, bisphenol S epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol novolac epoxy resins, biphenyl epoxy resins, naphthol epoxy resins, naphthalene epoxy resins, dicyclopentadiene epoxy resins, dicyclopentadiene novolac epoxy resins, triphenylmethane epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, phosphorus-containing epoxy resins, anthracene epoxy resins, norbornene epoxy resins, adamantane epoxy resins, fluorene epoxy resins, aminophenol epoxy resins, aminocresol epoxy resins, and alkylphenol epoxy resins. These epoxy resins may be used alone or in combination of two or more. Among these polyfunctional epoxy resins, from the viewpoint of further exhibiting the effects of the present invention, phenol novolac-type epoxy resins and cresol novolac-type epoxy resins are preferred, and phenol novolac-type epoxy resins are more preferred.

[0049] Examples of dibasic acid anhydrides used to synthesize epoxy-modified acrylic resins include phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride. These epoxy resins can be used alone or in combination of two or more. From the perspective of further enhancing the effects of the present invention, tetrahydrophthalic anhydride is preferred.

[0050] Therefore, from the perspective of further exerting the effects of the present invention, epoxy-modified acrylic resins obtained by reacting a phenol novolac epoxy resin or a cresol novolac epoxy resin with (meth)acrylic acid and adding tetrahydrophthalic anhydride to the hydroxyl groups present in the side chains are more preferred. From the perspective of minimizing residue after exposure and development, epoxy-modified acrylic resins obtained by reacting a phenol novolac epoxy resin with acrylic acid and adding tetrahydrophthalic anhydride to the hydroxyl groups present in the side chains are particularly preferred. From the same perspective, epoxy-modified acrylic resins obtained by further adding glycidyl (meth)acrylate to these epoxy-modified acrylic resins are also preferred.

[0051] As the above-mentioned (A) multifunctional acrylic resin, a commercial product or a synthetic product can be used. Specific examples of the synthetic product include the following compounds:

[0052] (1) A carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the hydroxyl groups present in the side chains.

[0053] (2) A carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin obtained by epoxidizing the hydroxyl groups of a bifunctional epoxy resin with epichlorohydrin with (meth)acrylic acid and adding a dibasic acid anhydride to the generated hydroxyl groups.

[0054] (3) A carboxyl group-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide to obtain a reaction product, reacting the reaction product with an unsaturated group-containing monocarboxylic acid, and reacting the reaction product obtained with a polyacid anhydride.

[0055] (4) A carboxyl group-containing resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate to obtain a reaction product, reacting the reaction product with a monocarboxylic acid containing an unsaturated group, and reacting the reaction product obtained with a polyacid anhydride.

[0056] (5) A carboxyl group-containing resin obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in the molecule, such as glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, or 3,4-epoxycyclohexylmethyl methacrylate, to the carboxyl group-containing resin described in (1) to (4) above.

[0057] The weight average molecular weight of the polyfunctional acrylic resin (A) is generally preferably 2,000 to 150,000, more preferably 3,000 to 30,000, and even more preferably 4,000 to 15,000. A weight average molecular weight of 2,000 or greater provides good resolution. On the other hand, a weight average molecular weight of 150,000 or less provides good developability.

[0058] The amount of the polyfunctional acrylic resin (A) is preferably 28 to 98% by mass, more preferably 50 to 95% by mass, and even more preferably 80 to 90% by mass, relative to the total mass of the polyfunctional acrylic resin (A), the polyfunctional acrylic monomer (B), and the polyamine (C). It should be noted that when calculating the total mass of the polyfunctional acrylic resin (A), the polyfunctional acrylic monomer (B), and the polyamine (C), only the mass of these components themselves is calculated, and the mass of the solvent used to dissolve or disperse these components is not included. When the amount is 28 to 98% by mass, the plating resist composition has moderate viscosity, which can improve coating properties and other aspects, and provides good plating resistance.

[0059] (B) Multifunctional acrylic monomer

[0060] The polyfunctional acrylic monomer (B) contained in the plating resist composition of the present invention is a compound having multiple (meth)acryloyl groups in its molecule. The polyfunctional acrylic monomer (B) is photocured by irradiation with active energy rays, thereby rendering the plating resist composition of the present invention insoluble in an alkaline aqueous solution or contributing to rendering the resin composition of the present invention insoluble in an alkaline aqueous solution.

[0061] Examples of such (B) multifunctional acrylic monomers include diacrylates of diols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; polyacrylates of polyols such as hexylene glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, and trishydroxyethyl isocyanurate, or their ethylene oxide adducts or propylene oxide adducts; polyacrylates of phenoxyacrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols; polyacrylates of glycidyl ethers such as glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine acrylates, and / or methacrylates corresponding to the above-mentioned acrylates.

[0062] Furthermore, examples include: epoxy acrylate resins obtained by reacting a multifunctional epoxy resin such as a cresol novolac epoxy resin with acrylic acid (such epoxy acrylate resins do not include those belonging to the above-mentioned (A) multifunctional acrylic resin); epoxy urethane acrylate compounds obtained by further reacting the hydroxyl group of the epoxy acrylate resin with a half-urethane compound (obtained by reacting a hydroxy acrylate such as pentaerythritol triacrylate with a diisocyanate such as isophorone diisocyanate); and the like.

[0063] These (B) polyfunctional acrylic monomers can be used alone or in combination of two or more.

[0064] From the viewpoint of achieving the effects of the present invention, it is preferred to include a trifunctional or higher acrylic monomer. Furthermore, from the viewpoint of improving resolution and plating resistance, it is more preferred to include a tetrafunctional or higher acrylic monomer, and even more preferred to include a pentafunctional or higher acrylic monomer.

[0065] The amount of the (B) polyfunctional acrylic monomer is 1 to 30% by mass relative to the total mass of the (A) polyfunctional acrylic resin, the (B) polyfunctional acrylic monomer, and the (C) polyamine. By including the (B) polyfunctional acrylic monomer in this amount along with the (C) polyamine described below, the plating resist composition can have excellent plating resistance and developability, thereby suppressing development residue and cell surface scratches.

[0066] If the amount of the multifunctional acrylic monomer (B) exceeds 30% by mass, the content of the multifunctional acrylic resin (A) becomes relatively low, the photocurability and developability during exposure decrease, and the resolution becomes poor. Even if the polyamine (C) described below is included, it is difficult to obtain satisfactory plating resistance, and there is a tendency for increased exposure and development residue. If the amount is less than 1% by mass, it is difficult to improve the photocurability, making it difficult to form a pattern by alkaline development after irradiation with active energy rays, and the resolution is poor. From the perspective of further exerting the effects of the present invention, the amount is more preferably 2 to 25% by mass, and even more preferably 5 to 20% by mass.

[0067] The molecular weight of the polyfunctional acrylic monomer (B) is generally preferably 200 to 3000, more preferably 250 to 2000, and even more preferably 300 to 1000. A weight average molecular weight of 200 or greater provides good resolution. On the other hand, a weight average molecular weight of 3000 or less provides good developability.

[0068] (C) Polyamine

[0069] The polyamine (C) contained in the plating-resistant composition of the present invention refers to a compound having multiple amino groups in its molecule. The amino groups contained in the polyamine (C) can be any one or more of primary amino groups, secondary amino groups, tertiary amino groups, and quaternary ammonium groups. From the perspective of improving plating resistance, it is preferred to contain a primary amino group. By containing the polyamine (C), the curability of the plating-resistant composition is improved, thereby improving plating resistance.

[0070] Examples of the polyamine (C) include ethylenediamine, hexamethylenediamine, dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N-dimethylbenzylamine, 4-methyl-N,N-dimethylbenzylamine, guanamine, methylguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-s-triazine, 2-vinyl-2,4-diamino-s-triazine, 2-vinyl-4,6-diamino-s-triazine-isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-s-triazine-isocyanuric acid adduct, and hexamethylenetetramine. These polyamines (C) may be used alone or in mixtures of two or more.

[0071] Among these (C) polyamines, from the viewpoint of improving plating resistance, polyamines having a triazine structure in the molecule are more preferred, and melamine is particularly preferred.

[0072] The amount of the polyamine (C) to be added is not particularly limited, but may be 0.2 to 10% by mass relative to the total mass of the polyfunctional acrylic resin (A), the polyfunctional acrylic monomer (B), and the polyamine (C). From the viewpoint of preferably exhibiting the effects of the present invention, the amount is preferably 0.5 to 8% by mass, and more preferably 1 to 5% by mass.

[0073] No inorganic fillers

[0074] The present invention does not contain inorganic fillers, thereby suppressing scratches on the surface of the battery cell and having a tendency to reduce development residues.

[0075] Inorganic fillers are typically inorganic powders, such as titanium oxide, silicon dioxide, barium sulfate, barium titanate, Neuburg silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, etc. In particular, the present invention does not contain titanium oxide, silicon dioxide, barium sulfate, talc, etc., which are commonly contained in conventional photoresists.

[0076] Other ingredients

[0077] The plating resist composition of the present invention may contain (D) a photopolymerization initiator. The (D) photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator generally used in plating resist compositions.

[0078] (D) Photopolymerization initiator includes, for example, acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, hydroxyketone compounds such as 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl-phenyl ketone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-methylpropanone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropane-1-one, Benzophenone, N,N'-tetraalkyl-4,4'-diaminobenzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1 and other aromatic ketones, 4,4'-bis(dimethylamino)benzophenone (Michler's ketone), 4,4'-bis(diethylamino)benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2 -dimethylamino-1-morpholinobenzophenone)-butanone-1,2-ethylanthraquinone, phenanthrenequinone and other aromatic ketones, benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether and other benzoin ethers, methyl benzoin, ethyl benzoin and other benzoin, benzyl derivatives such as benzyl dimethyl ketal, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-bis(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenyl Imidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer, 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer and other 2,4,5-triarylimidazole dimers, acridine derivatives such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane, N-phenylglycine, N-phenylglycine derivatives, coumarin compounds, etc.

[0079] As a commercially available (D) photopolymerization initiator, Omnirad TPO, Omnirad 127, Omnirad 184, Omnirad 1173, Omnirad 2959, Omnirad MBF etc. manufactured by IGM RESINS BV are mentioned.

[0080] Such (D) photopolymerization initiators can be used alone or in combination of two or more.

[0081] The plating resist composition of the present invention may contain (E) a colorant, and a known and commonly used organic colorant may be used. It should be noted that the (E) colorant that the plating resist composition of the present invention may contain does not include inorganic fillers.

[0082] Examples of the colorant (E) include perylene-based, phthalocyanine-based, anthraquinone-based, monoazo-based, disazo-based, azo lake-based, benzimidazolone-based, perylene-based, diketopyrrolopyrrole-based, condensed azo-based, anthraquinone-based, quinacridone-based, isoindolinone-based, and anthraquinone-based colorants.

[0083] Such (E) coloring agents may be used alone or in combination of two or more.

[0084] Furthermore, the plating resist composition of the present invention may contain (F) an organic solvent, which is used for preparation of the composition and adjustment of viscosity.

[0085] Examples of the organic solvent (F) include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. More specifically, the organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, diethylene glycol ethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha, and solvent naphtha.

[0086] Such (F) organic solvents may be used alone or in combination of two or more.

[0087] In addition, the plating resist composition of the present invention may also be blended with known and commonly used additives such as silicone-based, fluorine-based, and polymer-based defoamers and / or leveling agents, imidazole-based, thiazole-based, and triazole-based silane coupling agents, antioxidants, thickeners, and sensitizers as needed.

[0088] The plating resist composition of the present invention may be in the form of a dry film including a carrier film (support) and a layer composed of the plating resist composition formed on the carrier film.

[0089] When forming a dry film, the plating resist composition of the present invention is diluted with the aforementioned organic solvent and adjusted to an appropriate viscosity. The composition is then applied to a carrier film in a uniform thickness using a notch wheel coater, a knife coater, a lip coater, a rod coater, an extrusion coater, a reverse coater, a transfer roll coater, a gravure coater, a spray coater, or the like. The composition is then dried, typically at a temperature of 50 to 130° C. for 1 to 30 minutes, to form a resin layer as a dried coating. The resin layer is not particularly limited and is generally selected within a range of 10 to 150 μm, preferably 20 to 60 μm, in terms of film thickness after drying.

[0090] As the carrier film, a plastic film is used, preferably a polyester film such as polyethylene terephthalate, a polyimide film, a polyamide-imide film, a polypropylene film, a polystyrene film, or the like. The thickness of the carrier film is not particularly limited, but is generally selected within the range of 10 to 150 μm.

[0091] In this case, after forming the resin layer on the carrier film, a removable cover film is preferably further laminated on the surface of the resin layer to prevent dust from adhering to the surface of the resin layer. Examples of the removable cover film include polyethylene film, polytetrafluoroethylene film, polypropylene film, and surface-treated paper. When the cover film is peeled off, the adhesion between the resin layer and the cover film should be smaller than the adhesion between the resin layer and the carrier film.

[0092] As a method for producing a solar cell electrode using the plating resist composition of the present invention or a dry film thereof, a known production method can be adopted.

[0093] For example, the anti-plating composition of the present invention can be adjusted to a viscosity suitable for the coating method as needed, and applied to the surface of a solar cell formed into a pyramid-shaped velvet by methods such as screen printing, curtain coating, spraying, and roller coating. The solvent contained in the composition is evaporated and dried at a temperature of, for example, 60 to 100° C. as needed to form a coating film. Alternatively, the dry film of the present invention is laminated to the surface of a solar cell formed into a pyramid-shaped velvet, and the carrier film is peeled off to form a layer formed by the anti-plating composition on the surface of the solar cell. Then, the photomask having a predetermined exposure pattern is selectively exposed by active energy ray irradiation, and the unexposed portion is developed at a temperature of, for example, about 30° C. with a developer such as 1 to 2% Na2CO3 or K2CO3 solution for, for example, 60 to 90 seconds to form an anti-plating mask having a predetermined exposure pattern. Electroplating is performed on the surface of the cell formed with the anti-plating mask, thereby forming a metal layer as an electrode on the surface of the cell at the pattern gap. Then, the anti-plating mask is stripped and removed by using NaOH or KOH solution at a temperature of 40 to 70° C., and then a solder layer is plated by PVD. After sintering, a solar cell module with electrodes is obtained.

[0094] Example

[0095] The embodiments of the present invention will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be obtained commercially.

[0096] In addition, unless otherwise specified, "parts" and "%" below are based on mass.

[0097] The plating resist compositions of Examples 1 to 3 and Comparative Examples 1 to 4 were obtained by mixing the components shown in Table 1 at the indicated blending ratios (based on mass).

[0098]

Table 1

[0099]

[0100] - Indicates that it does not contain

[0101] Remark:

[0102] A-1: Cresol novolac type epoxy-modified acrylic resin (solid content 64%) prepared in Synthesis Example 1

[0103] A-2: Epoxy-modified acrylic resin of the phenol novolac type prepared in Synthesis Example 2 (solid content 64%)

[0104] B-1MT3501A, manufactured by Zhangjiagang Dongya DIC Chemical Co., Ltd., a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (solids 100%)

[0105] B-2 Propane trimethylol triacrylate TMPTA (solid content 100%), manufactured by Nippon Kayaku Co., Ltd.

[0106] C melamine, made by Guangzhou Jiachun Electronics Co., Ltd.

[0107] 4-Nitroaniline N,N-dimethyl-4-nitroaniline manufactured by Quzhou Mingfeng Chemical Co., Ltd.

[0108] D-1EAB, manufactured by BASF, Germany

[0109] D-2#907, manufactured by BASF, Germany

[0110] E phthalocyanine blue, manufactured by Lianyungang DISON Color Co., Ltd.

[0111] Defoamer KSZ-66, manufactured by Zhejiang Shin-Etsu Fine Chemical Co., Ltd.

[0112] Sensitizer GR-ITX, manufactured by Hubei Gurun Technology Co., Ltd.

[0113] Talc HD25, manufactured by Fushi (Shanghai) Trading Co., Ltd.

[0114] Filler powder barium sulfate, BRILLANT-A1, manufactured by Guangzhou Jimei Bailang Chemical Co., Ltd. Synthesis Example 1

[0115] 1070 parts of an o-cresol novolac-type epoxy resin (EPICLONN-695, manufactured by DIC Corporation, softening point 95°C, epoxy equivalent 214) (glycidyl group number (total number of aromatic rings): 5.0 mol), 360 parts (5.0 mol) of acrylic acid, and 1.5 parts of hydroquinone were added to 650 parts of diethylene glycol monoethyl ether acetate, and the mixture was heated to 100°C and stirred to uniformly dissolve. Next, 4.3 parts of triphenylphosphine were added, and the mixture was heated to 110°C and allowed to react for 2 hours. An additional 1.6 parts of triphenylphosphine was then added, and the temperature was raised to 120°C, and the reaction was continued for a further 12 hours. To the resulting reaction solution, 525 parts of an aromatic hydrocarbon (SOLVESSO 150) and 608 parts (4.0 mol) of tetrahydrophthalic anhydride were added, and the mixture was allowed to react at 110°C for 4 hours. Furthermore, 142.0 parts (1.0 mol) of glycidyl methacrylate was added to the obtained reaction solution, and the mixture was reacted at 115° C. for 4 hours to obtain a cresol novolac-type epoxy-modified acrylic resin solution having a solid acid value of 83 mgKOH / g and a solid content of 64%.

[0116] Synthesis example 2

[0117] 950 parts of a phenol novolac-type epoxy resin (EPICLONN-770, manufactured by DIC Corporation, softening point 65-75°C, epoxy equivalent 190) (glycidyl group number (total number of aromatic rings): 5.0 mol), 360 parts of acrylic acid (5.0 mol), and 1.5 parts of hydroquinone were added to 650 parts of diethylene glycol monoethyl ether acetate, heated to 100°C, and stirred until uniformly dissolved. Next, 4.3 parts of triphenylphosphine were added, heated to 110°C, and reacted for 2 hours. An additional 1.6 parts of triphenylphosphine was then added, the temperature was raised to 120°C, and the reaction was continued for a further 12 hours. To the resulting reaction solution, 525 parts of an aromatic hydrocarbon (SOLVESSO 150) and 608 parts of tetrahydrophthalic anhydride (4.0 mol) were added, and the reaction was continued at 110°C for 4 hours. Furthermore, 770 parts (5.4 mol) of glycidyl methacrylate was added to the obtained reaction solution, and the mixture was reacted at 115° C. for 4 hours to obtain a phenol novolac-type epoxy-modified acrylic resin solution having a solid content acid value of 58 mgKOH / g and a solid content of 64%.

[0118] The plating resist compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were subjected to the following performance evaluation.

[0119] Evaluation methods and benchmarks

[0120] (1) Resolution evaluation

[0121] The anti-plating composition of the above-mentioned embodiment and comparative example was applied to the surface of the solar cell, dried at 80°C for 15 minutes, and cooled to room temperature to form a resin layer with a thickness of 10 μm. For the upper surface (exposed surface) of the dried composition, a DI exposure machine (Ledia6 manufactured by SCREEN Co., Ltd.) was used to expose the pattern design with line / space of 10 μm / 10 μm, 20 μm / 20 μm, 30 μm / 30 μm, 40 μm / 40 μm, 50 μm / 50 μm, 60 μm / 60 μm, 70 μm / 70 μm, 80 μm / 80 μm, 90 μm / 90 μm, 100 μm / 100 μm, and 200 μm / 200 μm, with a 405 nm light source output of 100% and a 400 mJ / cm 2 The film was exposed at an exposure dose of 1000 nm and developed using a 1 mass % sodium carbonate aqueous solution at 30° C. under a spray pressure of 2 kg for 60 seconds to obtain an evaluation substrate.

[0122] The minimum designed line width remaining on the substrate was visually confirmed and recorded in Table 1 as an evaluation of resolution.

[0123] (2) Evaluation of development residue

[0124] The resist plating composition of the above embodiment and comparative example was applied to the entire surface of the solar cell, dried at 80°C for 20 minutes, and cooled to room temperature to form a resin layer with a thickness of 10 μm. The upper surface (exposed surface) of the dried composition was exposed using a DI exposure machine (Ledia6 manufactured by SCREEN) with a 405 nm light source output of 100% and a 400 mJ / cm 2 The pattern was exposed with an exposure dose of 1000 nm, and developed using a 1 mass % sodium carbonate aqueous solution at 30° C. and a spray pressure of 2 kg for 60 seconds to obtain an evaluation substrate.

[0125] The carbon content of the developed window surface was measured using an energy dispersive X-ray spectrometer (Hitachi SU3500 EDS: Thermo UltraDry 5225 (sample Pt pretreatment)). The exposure and development residue of the composition was evaluated based on the carbon content. The evaluation criteria were as follows.

[0126] C% is 0% or more and less than 5% ○

[0127] C% is 5% or more and less than 10% △

[0128] C% is 10% or more ×

[0129] (3) Evaluation of copper plating resistance

[0130] The evaluation substrate obtained in the above (2) was subjected to a copper electroplating process to evaluate the copper electroplating resistance.

[0131] In the copper electroplating process, the plating solution used is: copper sulfate (CuSiO4·5H2O) 200g / L, sulfuric acid (H2SO4) 80g / L, chloride ion (Cl-) 70mg / L, inhibitor 13ml / L, brightener 30ml / L, leveler 20ml / L. The electroplating operating conditions are: temperature 20-25℃, current density 5A / dm 2 , the stirring intensity is strong, and the electroplated copper thickness is 10μm.

[0132] The evaluation items are: 1) whether there is any peeling of the plating resist composition on the surface of the cell after copper plating, and whether there is any cross-circuiting of the copper grid lines; 2) after the copper is plated, a 3M tape stress pull-off test is performed to see if the copper grid lines are peeling off.

[0133] The evaluation criteria are as follows:

[0134] After copper plating, there is no peeling of the resist composition on the surface of the cell, no cross-circuiting of the copper grid lines, and no peeling of the copper grid lines during the 3M tape stress pull-off test.

[0135] After copper plating, there is no peeling of the resist composition on the surface of the cell, and no copper grid cross-circuit. However, the copper grid is peeled off during the 3M tape stress pull-off test.

[0136] After copper plating, the surface of the cell is peeled off due to the resist composition, or there is a copper grid cross-circuit.

[0137] (4) Evaluation of fading

[0138] The evaluation substrate obtained in the above (2) was evaluated for washability under the following two conditions.

[0139] Sodium hydroxide 5 mass% solution is kept at 60℃ for 5 minutes

[0140] Sodium hydroxide 5 mass% solution is kept at 70℃ for 5 minutes

[0141] The evaluation criteria are as follows:

[0142] After soaking in the stripping solution, there is no residue on the surface of the substrate.

[0143] After soaking in the washing liquid, there is a slight residue, and no residue after washing.

[0144] After soaking in the degreasing solution, there is a residue, and after washing with water, there is still a residue ×

[0145] The results of the aforementioned evaluation tests are collectively shown in Table 1 above.

[0146] As can be clearly seen from Table 1, in Examples 1 to 3, which simultaneously contain 1 to 30% by mass of (B) multifunctional acrylic monomers and (C) polyamines and do not contain inorganic fillers, the evaluations of resolution, development residue, copper plating resistance, and wash-off performance are all excellent results. Among them, compared with Example 3 using propane trimethylol triacrylate as the (B) multifunctional acrylic monomer, the evaluations of resolution, development residue, and copper plating resistance in Example 1 using a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate are even more excellent results. Compared with Example 2 using both A-1 cresol novolac type epoxy-modified acrylic resin and A-2 phenol novolac type epoxy-modified acrylic resin as the (A) multifunctional acrylic resin, the evaluations of development residue and copper plating resistance in Example 1 using only A-2 phenol novolac type epoxy-modified acrylic resin are even more excellent results.

[0147] In contrast, for Comparative Examples 1 and 2, which contain talc and barium sulfate as inorganic fillers, significant scratches were observed on the solar cell surface after the washout evaluation, failing to meet the present invention's requirement for suppressing cell surface scratches, as in Examples 1-3. Furthermore, while the development residue evaluation results for Comparative Examples 1 and 2 were at a practical level, they were significantly inferior to those of Example 1. This is presumably due to the resin component remaining in surface scratches after development. Comparative Example 3, which contains p-nitroaniline but no polyamine, exhibited poor resistance to copper electroplating. (B) Comparative Example 4, which contains a polyfunctional acrylic monomer content exceeding 30%, exhibited poor resistance to copper electroplating.

[0148] These results indicate that the plating-resistant composition of the present invention comprises 1 to 30% by mass of both (B) a multifunctional acrylic monomer and (C) a polyamine and contains no inorganic filler, thereby exhibiting high resolution, low development residue, excellent copper plating resistance and wash-off performance, and is suitable for use as a photoresist in the manufacture of solar cell electrodes.

[0149] It should be noted that, although the technical solutions of the present invention are described with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto.

[0150] While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A plating resist composition, characterized in that: The invention comprises (A) a multifunctional acrylic resin, (B) a multifunctional acrylic monomer and (C) a polyamine, and does not contain an inorganic filler, wherein, relative to the total mass of the (A) multifunctional acrylic resin, the (B) multifunctional acrylic monomer and the (C) polyamine, the (B) multifunctional acrylic monomer is 5 to 20% by mass, the (C) polyamine is 1 to 5% by mass, The (A) multifunctional acrylic resin comprises an epoxy-modified acrylic resin, The epoxy-modified acrylic resin is a resin obtained by reacting a multifunctional epoxy resin with (meth)acrylic acid, adding a dibasic acid anhydride to the hydroxyl groups present in the side chain, and further adding a compound having one epoxy group and one or more (meth)acryloyl groups to the obtained resin. The multifunctional epoxy resin is a phenol novolac type epoxy resin, the dibasic acid anhydride is tetrahydrophthalic anhydride, and the compound having one epoxy group and one or more (meth)acryloyl groups is glycidyl (meth)acrylate. The (C) polyamine is melamine.

2. The plating resist composition according to claim 1, wherein The (A) multifunctional acrylic resin has a plurality of carboxyl groups in addition to a plurality of (meth)acryloyl groups in the molecule.

3. The plating resist composition according to claim 1 or 2, characterized in that: The (A) polyfunctional acrylic resin is present in an amount of 28 to 98% by mass relative to the total mass of the (A) polyfunctional acrylic resin, the (B) polyfunctional acrylic monomer, and the (C) polyamine.

4. The plating resist composition according to claim 1 or 2, characterized in that: The (B) multifunctional acrylic monomer includes a tetrafunctional or higher-functional acrylic monomer. 5 . Use of the plating resist composition according to claim 1 in producing an electrode for a solar cell.

6. A dry film, characterized in that The plating resist composition according to any one of claims 1 to 4 is applied on a carrier film and dried.

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