Photosensitive resin composition, resist ink, resist laminate, and use thereof

Abstract

The application provides a photosensitive resin composition, a resist ink, a resist laminated body and application thereof. The photosensitive resin composition comprises, in parts by weight, 50-70 parts of an alkali-soluble resin, 30-50 parts of a photopolymerizable monomer and 0.1-4.0 parts of a photoinitiator; wherein the photopolymerizable monomer comprises an allyl compound and a mercapto compound, and the mass content of the mercapto compound in the photopolymerizable monomer is 7wt%-22wt%. The application introduces the allyl compound and the mercapto compound into the photosensitive resin composition, the alkyl group in the allyl compound can add polymerize with the mercapto group in the mercapto compound, which helps to make the prepared photosensitive resin have relatively uniform crosslinking after exposure, and obtain a photosensitive resin with low polymerization shrinkage stress, which shows good adhesion in the bonding process of a copper substrate.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board technology, and more specifically, to a photosensitive resin composition, a photoresist ink, a photoresist laminate, and their applications. Background Technology

[0002] Dry film resists are widely used as key materials for pattern transfer in products such as printed circuit boards, lead frames, solar cells, conductor packages, ball grid arrays (BGAs), and chip-scale packaging (CPS). For example, in printed circuit boards, a dry film resist laminate is bonded to a copper substrate, and the pattern is exposed using laser direct imaging (LDI). Then, development is performed to remove the unexposed areas, followed by etching or electroplating. Finally, the film is removed to remove the cured parts, thereby achieving pattern transfer.

[0003] For the production of high-density and highly integrated printed circuit board (PCB) products such as high-density interconnect (HDI) boards and packaging substrates, the required precision is generally around 15μm or even lower. This requires the dry film resist layer, which acts as a pattern transfer layer, to have higher resolution and excellent adhesion to the copper substrate. This ensures that the dry film remains intact and adheres to the copper-clad laminate substrate even after harsh processes such as development, electroplating, or etching, which involve high-pressure spraying and prolonged contact with corrosive chemical reagents.

[0004] Chinese patent CN102385253B discloses a photosensitive resin composition with excellent resolution and peel properties achieved by using an adhesive polymer with a specific structure, namely, a polymer containing benzyl methacrylate and styrene structures. Chinese patent application CN110531583A discloses that adding hydroxyethyl methacrylate to an alkali-soluble resin significantly enhances its resistance to acid etching and electroplating solutions and its peel performance. Chinese patent application CN117008417A discloses the synthesis of an alkali-soluble resin using alicyclic comonomers, exhibiting good flexibility and hydrophobicity. However, these patents disclose relatively long peeling times, and there is still room for improvement in peeling performance. Summary of the Invention

[0005] The main objective of this invention is to provide a photosensitive resin composition, a photoresist ink, a photoresist laminate, and their applications, in order to solve the problems of poor resolution, adhesion, stripping performance, electroplating resistance, and storage stability of photosensitive resins used in photoresist laminates in the prior art.

[0006] To achieve the above objectives, according to one aspect of the present invention, a photosensitive resin composition is provided, comprising, by weight, 50 to 70 parts of an alkali-soluble resin, 30 to 50 parts of a photopolymerizable monomer, and 0.1 to 4.0 parts of a photoinitiator; wherein the photopolymerizable monomer comprises an allyl compound and a thiol compound, and the thiol compound comprises, by weight, 7 wt% to 22 wt% of the photopolymerizable monomer.

[0007] Furthermore, the allyl compound accounts for 5 wt% to 14 wt% of the photopolymerizable monomer by mass; and / or, the mercapto compound accounts for 8 wt% to 22 wt% of the photopolymerizable monomer by mass; preferably, the mass ratio of the allyl compound to the mercapto compound is 0.625 to 1:1.

[0008] Further, the allyl compound is selected from any one or more of allyl (meth)acrylate, diallyl carbonate, allyl benzyl ether, 2,4,6-trienylpropoxy-1,3,5-triazine, tert-butoxy-N-carbamate, diethyl allyl malonate, eugenol and its derivatives, safrole and its derivatives, artemisinin and its derivatives; and / or, the thiol compound is selected from methanethiol, ethanethiol, 1-propanethiol, n-butanethiol, and dodecanethiol. Ethylene dithiol, 1,3-propanedithiol, 2,3-dimercaptopropanol, hexanedithiol, 1,4-dimethylbenzylthiophenol, tris(2-hydroxyethyl)isocyanurate tris(mercaptopropionate), diethanolamine tris(mercaptopropionate), bis(3-mercaptopropionic acid) ethylene glycol, hydroxymethylpropane tris(3-mercaptopropionate), pentaerythritol tetras(3-mercaptopropionate), benzylmercaptopropionate, cysteine, and bis(3-mercaptopropionic acid) ethylene glycol.

[0009] Further, the above-mentioned photopolymerizable monomer includes acrylate compounds; preferably, the mass percentage of acrylate compounds in the photopolymerizable monomer is 65wt% to 86wt%; and / or, the photopolymerizable monomer includes unsaturated fatty acids; preferably, the mass percentage of unsaturated fatty acids in the photopolymerizable monomer is 1wt% to 5wt%; more preferably, the photopolymerizable monomer includes acrylate compounds and unsaturated fatty acids, and the mass ratio of acrylate compounds to unsaturated fatty acids is 12.5 to 26:1.

[0010] Furthermore, the aforementioned acrylate compounds are selected from lauryl acrylate, octadecyl methacrylate, nonylphenol acrylate, ethoxylated (propoxylated) nonylphenol acrylate, tetrahydrofuran methyl acrylate, bisphenol A dimethacrylate, ethoxylated (propoxylated) bisphenol A dimethacrylate, polyethylene glycol (propylene glycol) dimethacrylate, ethoxylated (propoxylated) neopentyl glycol diacrylate, trimethylolpropane trimethacrylate, ethoxylated (propoxylated) trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol pentaacrylate. The acrylate compound is selected from any one or more of tetraol hexaacrylates; preferably, it is a combination of bisphenol A dimethacrylate and trimethylolpropane trimethacrylate, and the mass ratio of bisphenol A dimethacrylate to trimethylolpropane trimethacrylate is 12-20:5-16; and / or, the unsaturated fatty acid is selected from any one or more of 9-octadecenoic acid, 9,12-octadecadienoic acid, 9,12,15-octadectrienoic acid, 9,11,13-octadectrienoic acid, and 12-hydroxy-9-octadecenoic acid.

[0011] Further, the acid value of the above-mentioned alkali-soluble resin is 120–250 mg KOH / g; and / or, the weight-average molecular weight of the alkali-soluble resin is 20,000–120,000; and / or, the polydispersity index of the alkali-soluble resin is 1.3–2.5; and / or, the alkali-soluble resin is prepared from polymeric monomers selected from (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, isooctyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and glycidyl methacrylate. Allyl methacrylate, polyethylene (or propylene) glycol (meth)acrylate, styrene and its derivatives, benzyl methacrylate, p-oxyphenyl benzyl methacrylate, phenoxyethyl methacrylate, o-phenylphenoxyethyl methacrylate, adamantane methacrylate, cyclopentadienyl methacrylate, isobornyl methacrylate; preferably, the polymerizing monomer is selected from methacrylic acid, methyl methacrylate, butyl acrylate, styrene and butyl methacrylate.

[0012] Further, the photoinitiator is selected from any one or more of the following: azo compounds, peroxide compounds, α-hydroxy ketone compounds, α-amino ketone compounds, acylphosphine compounds, α-oxyacyloxime ester compounds, hexaaryl diimidazole derivatives, acridine derivatives, benzoyl ether, benzophenone and its derivatives, thioxanthone derivatives, anthraquinone and its derivatives, aromatic diazonium salts, iodonium salts, thiodonium salts, aromatic ferrocene salts, titanoceramsite photoinitiators, and nonionic acid-producing agents; preferably, the photoinitiator is selected from 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-di(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycerol. The photoinitiator is any one or more amino acids; more preferably, it is a combination of 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-di(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycine, wherein the mass ratio of 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-di(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycine is 1.5–1.8: 0.4–0.7: 0.05–0.1: 0.05: 0.1.

[0013] According to another aspect of the invention, a photoresist ink is provided, which contains the aforementioned photosensitive resin composition.

[0014] According to another aspect of the present invention, a photoresist laminate is provided, comprising a support layer, a photosensitive resin layer and a protective layer stacked sequentially, wherein the photosensitive resin layer is prepared from the aforementioned photosensitive resin composition or the aforementioned photoresist ink.

[0015] According to another aspect of the invention, the application of the aforementioned resist laminate on a circuit board is provided.

[0016] By applying the technical solution of this application, an allyl compound and a thiol compound are introduced into the photosensitive resin composition. The alkenyl group in the allyl compound can undergo an addition polymerization reaction with the thiol group in the thiol compound. Since the polymerization reaction of the thiol-alkene reaction system lasts longer than the free radical double bond copolymerization reaction of other photopolymerizable monomers, it helps to achieve more uniform crosslinking of the prepared photosensitive resin after exposure. The shrinkage stress during the polymerization process is alleviated, resulting in a photosensitive resin with low polymerization shrinkage stress. This photosensitive resin with low polymerization shrinkage stress exhibits better adhesion during the bonding process with copper substrates. The introduction of the thiol-alkene reaction system improves the bonding strength between the photosensitive resin and the copper substrate, thus reducing the risk of abnormalities such as plating overflow in the pattern electroplating process, thereby improving product yield. The photosensitive resin composition of this invention incorporates a photo- or thermally decomposable initiator, which can initiate a partial reaction of the thiol-alkene reaction system during the drying process. This helps to give the photosensitive resin a slightly crosslinked network support, thereby reducing the risk of resin overflow and thus improving the storage stability of the photosensitive resin. If the mass percentage of thiol compounds in the photopolymerizable monomers is too low, it will be detrimental to improving the peeling performance, electroplating resistance, and storage stability of the photosensitive resin. If the mass percentage of thiol compounds in the photopolymerizable monomers is too high, it will be detrimental to improving the resolution and adhesion performance of the photosensitive resin. It is preferable to control the mass percentage of thiol compounds in the photopolymerizable monomers within the above-mentioned range, which will help improve the overall performance of the photosensitive resin, including its resolution, adhesion, peeling performance, electroplating resistance, and storage stability. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0018] As analyzed in the background section of this application, the photosensitive resins used in resist laminates in the prior art have problems with poor resolution, adhesion, stripping performance, electroplating resistance, and storage stability. In order to solve this problem, this application provides a photosensitive resin composition, a resist ink, a resist laminate, and its applications.

[0019] In a typical embodiment of this application, a photosensitive resin composition is provided, comprising, by weight: 50-70 parts of an alkali-soluble resin; 30-50 parts of a photopolymerizable monomer; and 0.1-4.0 parts of a photoinitiator; wherein the photopolymerizable monomer comprises an allyl compound and a thiol compound, and the thiol compound has a mass content of 7 wt%-22 wt% in the photopolymerizable monomer.

[0020] This application introduces allyl and mercapto compounds into a photosensitive resin composition. The alkenyl group in the allyl compound can undergo an addition polymerization reaction with the mercapto group in the mercapto compound. Since the polymerization reaction of the mercapto-alkene reaction system lasts longer than the free radical double bond copolymerization reaction of other photopolymerizable monomers, it helps to achieve more uniform crosslinking of the prepared photosensitive resin after exposure. This alleviates the shrinkage stress during polymerization, resulting in a photosensitive resin with low polymerization shrinkage stress. The photosensitive resin with low polymerization shrinkage stress exhibits better adhesion during the bonding process with copper substrates. The introduction of the mercapto-alkene reaction system improves the bonding strength between the photosensitive resin and the copper substrate, thus reducing the risk of abnormalities such as plating overflow in the pattern electroplating process, thereby improving product yield. The photosensitive resin composition of this invention incorporates a photo- or thermally decomposable initiator, which can initiate a partial reaction of the mercapto-alkene reaction system during the drying process. This helps to provide a slightly crosslinked network support for the photosensitive resin, thereby reducing the risk of resin run-through and improving the storage stability of the photosensitive resin. If the mass percentage of thiol compounds in the photopolymerizable monomers is too low, it will be detrimental to improving the peeling performance, electroplating resistance, and storage stability of the photosensitive resin. If the mass percentage of thiol compounds in the photopolymerizable monomers is too high, it will be detrimental to improving the resolution and adhesion performance of the photosensitive resin. It is preferable to control the mass percentage of thiol compounds in the photopolymerizable monomers within the above-mentioned range, which will help improve the overall performance of the photosensitive resin, including its resolution, adhesion, peeling performance, electroplating resistance, and storage stability.

[0021] In one embodiment of this application, the allyl compound accounts for 5 wt% to 14 wt% of the photopolymerizable monomer; and / or, the mercapto compound accounts for 8 wt% to 22 wt% of the photopolymerizable monomer; preferably, the mass ratio of the allyl compound to the mercapto compound is 0.625 to 1:1.

[0022] Preferably controlling the mass percentages of allyl compounds and mercapto compounds in photopolymerizable monomers within the aforementioned ranges helps to fully leverage their synergistic effect, enabling the alkenyl groups in the allyl compounds to undergo addition polymerization with the mercapto groups in the mercapto compounds. This, in turn, helps to improve the overall performance of the photosensitive resin, including its resolution, adhesion, film removal, electroplating resistance, and storage stability.

[0023] In one embodiment of this application, the allyl compound is selected from any one or more of allyl (meth)acrylate, diallyl carbonate, allyl benzyl ether, 2,4,6-trienylpropoxy-1,3,5-triazine, tert-butoxy-N-carbamate, diethyl allyl malonate, eugenol and its derivatives, safrole and its derivatives, artemisinin and its derivatives; and / or, the thiol compound is selected from methanethiol, ethanethiol, 1-propanethiol, and n-butanethiol. The following are any one or more of the following: dodecyl mercaptan, ethylenedithiol, 1,3-propanedithiol, 2,3-dimercaptopropanol, hexanedithiol, 1,4-dimethylbenzylthiophenol, tris(2-hydroxyethyl)isocyanurate tris(mercaptopropionate), diethanolamine tris(mercaptopropionate), bis(3-mercaptopropionic acid) ethylene glycol, hydroxymethylpropane tris(3-mercaptopropionate), pentaerythritol tetras(3-mercaptopropionate), benzylmercaptopropionate, cysteine, and bis(3-mercaptopropionic acid) ethylene glycol.

[0024] Preferably controlling the types of allyl and mercapto compounds within the above-mentioned range helps to enrich the selectivity of allyl and mercapto compounds and further improve the compatibility between allyl and mercapto compounds, thereby helping to further improve the overall performance of photosensitive resins, such as resolution, adhesion, film removal, electroplating resistance, and storage stability.

[0025] In one embodiment of this application, the photopolymerizable monomer includes acrylate compounds; preferably, the mass percentage of acrylate compounds in the photopolymerizable monomer is 65wt% to 86wt%; and / or, the photopolymerizable monomer includes unsaturated fatty acids; preferably, the mass percentage of unsaturated fatty acids in the photopolymerizable monomer is 1wt% to 5wt%; more preferably, the photopolymerizable monomer includes acrylate compounds and unsaturated fatty acids, and the mass ratio of acrylate compounds to unsaturated fatty acids is 12.5 to 26:1.

[0026] Preferably controlling the mass ratio of acrylate compounds in the photopolymerizable monomers within the aforementioned range helps to further improve the resolution, adhesion, and release properties of the photosensitive resin. The addition of unsaturated fatty acids helps to imbue the crosslinked network of the photosensitive resin with carboxyl groups after exposure, thereby improving the release properties of the photosensitive resin. Simultaneously, unsaturated fatty acids are biorenewable resources, and the thiol-olefin reaction system can therefore incorporate more renewable monomers, offering greater environmental advantages. Preferably controlling the mass ratio of unsaturated fatty acids in the photopolymerizable monomers within the aforementioned range helps to further improve the release properties of the photosensitive resin.

[0027] To further improve the resolution, adhesion, and release properties of the photosensitive resin, in one embodiment of this application, the acrylate compound is preferably selected from lauryl methacrylate, octadecyl methacrylate, nonylphenol acrylate, ethoxylated (propionyl acrylate) nonylphenol acrylate, tetrahydrofuran methyl acrylate, bisphenol A dimethacrylate, ethoxylated (propionyl acrylate) bisphenol A dimethacrylate, polyethylene glycol (propylene glycol) dimethacrylate, ethoxylated (propionyl acrylate) neopentyl glycol diacrylate, trimethylolpropane trimethacrylate, ethoxylated (propionyl acrylate) trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetrapropylene The acrylate compound is selected from any one or more of acrylates, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate; preferably, the acrylate compound is a combination of bisphenol A dimethacrylate and bisphenol A trimethylolpropane trimethacrylate, and the mass ratio of bisphenol A dimethacrylate to bisphenol A trimethylolpropane trimethacrylate is 12-20:5-16; and / or, the unsaturated fatty acid is selected from any one or more of 9-octadecenoic acid, 9,12-octadecadienoic acid, 9,12,15-octadectrienoic acid, 9,11,13-octadectrienoic acid, and 12-hydroxy-9-octadecenoic acid.

[0028] It should be noted that in the above acrylate compounds, "(methyl)" refers to whether it is substituted with methyl or not; "(propionyl oxide)" refers to whether it is substituted with propionyl oxide group or not.

[0029] In one embodiment of this application, the acid value of the alkali-soluble resin is 120–250 mg KOH / g; and / or, the weight-average molecular weight of the alkali-soluble resin is 20,000–120,000; and / or, the polydispersity index of the alkali-soluble resin is 1.3–2.5; and / or, the alkali-soluble resin is prepared from polymeric monomers selected from (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, isooctyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and glycidyl methacrylate. Allyl methacrylate, polyethylene (or propylene) glycol (meth)acrylate, styrene and its derivatives, benzyl methacrylate, p-oxyphenyl benzyl methacrylate, phenoxyethyl methacrylate, o-phenylphenoxyethyl methacrylate, adamantane methacrylate, cyclopentadienyl methacrylate, isobornyl methacrylate; preferably, the polymerizing monomer is selected from methacrylic acid, methyl methacrylate, butyl acrylate, styrene and butyl methacrylate.

[0030] It should be noted that in the above polymer monomers, "(methyl)" refers to whether it is substituted with a methyl group or not.

[0031] The above-mentioned alkali-soluble resin was prepared by solution polymerization, with azobisisobutyronitrile as the initiator and acetone as the solvent, and was obtained by reacting in a closed reactor at 80°C for a period of time.

[0032] To control the polymerization rate of photopolymerizable monomers and thereby improve the overall performance of photosensitive resins, including resolution, adhesion, film removal, electroplating resistance, and storage stability, in one embodiment of this application, the photoinitiator is preferably selected from any one or more of the following: azo compounds, peroxide compounds, α-hydroxy ketones, α-amino ketones, acylphosphides, α-oxyacyloxime esters, hexaaryl diimidazole derivatives, acridine derivatives, benzoyl ether, benzophenone and its derivatives, thioxanthone derivatives, anthraquinones and their derivatives, aromatic diazonium salts, iodonium salts, thiodonium salts, aromatic ferrocene salts, titanocene photoinitiators, and nonionic acid-producing agents; preferably, the photoinitiator is selected from 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenyloxy Phosphorus, 4,4-bis(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycine are any one or more of these; further preferably, the photoinitiator is 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-bis(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycine. The combination of N-phenylglycine, wherein the mass ratio of 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-bis(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile and N-phenylglycine is 1.5–1.8:0.4–0.7:0.05–0.1:0.05:0.1.

[0033] To further improve the overall performance of the photosensitive resin, in one embodiment of this application, the photosensitive resin composition preferably further includes 0.05 to 4.0 parts of additives; preferably, the additives are selected from any one or more of photochromic agents, dyes, plasticizers, antioxidants, deodorizers, color heat stabilizers, adhesion promoters, leveling agents, defoamers, and polymerization inhibitors.

[0034] The types of photochromic agents, dyes, plasticizers, antioxidants, deodorizers, color heat stabilizers, adhesion promoters, leveling agents, defoamers, and polymerization inhibitors used in this application can be those commonly used in the art. For example, the photochromic agent is leuco crystal violet, the dye is malachite green, the plasticizer is p-toluenesulfonamide, the antioxidant is antioxidant 1010, the deodorizer is activated carbon, the color heat stabilizer is phenolphthalein, the adhesion promoter is formic acid, the leveling agent is polydimethylsiloxane, the defoamer is polymethylsiloxane, and the polymerization inhibitor is hydroquinone.

[0035] In another typical embodiment of this application, a photoresist ink is provided, which contains the aforementioned photosensitive resin composition.

[0036] In another typical embodiment of this application, a photoresist laminate is provided, comprising a support layer, a photosensitive resin layer and a protective layer stacked sequentially, wherein the photosensitive resin layer is prepared from the aforementioned photosensitive resin composition or the aforementioned photoresist ink.

[0037] Since the photosensitive resin layer in the above-mentioned resist laminate is prepared from the photosensitive resin composition of this application, the resist laminate has excellent comprehensive properties such as resolution, adhesion, stripping performance, electroplating resistance and storage stability.

[0038] Including but not limited to, the material of the support layer is polyethylene terephthalate and / or polypropylene; the material of the protective layer is polyethylene.

[0039] In another typical embodiment of this application, the application of the aforementioned resist laminate on a circuit board is provided.

[0040] The beneficial effects of this application will be further illustrated below with reference to the embodiments.

[0041] Example 1

[0042] Alkali-soluble resin A: prepared by solution polymerization, with azobisisobutyronitrile as the initiator and acetone as the solvent, and reacted in a closed reactor at 80°C for a period of time.

[0043] A1: The main components and mass ratio of the polymer monomers are methacrylic acid / methyl methacrylate / butyl acrylate / butyl methacrylate = 24 / 46 / 20 / 10, the weight average molecular weight of A1 is Mw = 55000, and the polydispersity index is 1.78.

[0044] A2: Prepared by solution polymerization, with azobisisobutyronitrile as the initiator and acetone as the solvent. It is prepared by reaction in a closed reactor at 80°C for a period of time. The main components and mass ratio of the monomers are methacrylic acid / methyl methacrylate / styrene / butyl methacrylate = 27 / 7 / 46 / 10. The weight average molecular weight of A2 is Mw = 55000 and the polydispersity index is 1.78.

[0045] Photopolymerizable monomer B:

[0046] B1: Allyl methacrylate;

[0047] B2: (10) Bisphenol A dimethacrylate ester, Shanxi Meiyuan Chemical Co., Ltd.;

[0048] B3: (6) Ethylene oxide trimethylolpropane triacrylate, Sartoma Chemical Co., Ltd.;

[0049] B4: Bis(3-mercaptopropionic acid)ethylene glycol, Shanghai Maclean Biochemical Technology Co., Ltd.;

[0050] B5: 2,4,6-Trienylpropoxy-1,3,5-triazine, Shanghai Maclean Biochemical Technology Co., Ltd.;

[0051] B6: 12-Hydroxy-9-octadecenoic acid, Hangzhou Jieheng Chemical Co., Ltd.

[0052] Photoinitiator C:

[0053] C1: 2,2',4-Tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, Changzhou Qiangli Electronic New Materials Co., Ltd.;

[0054] C2: 2,4,6-Trimethylbenzoyl-diphenylphosphine oxide, Shanghai Maclean Biochemical Technology Co., Ltd.;

[0055] C3: 4,4-Di(N,N'-Dimethylamino)benzophenone, Changzhou Qiangli Electronic New Materials Co., Ltd.;

[0056] C4: Azobisisobutyronitrile, Shanghai Maclean Biochemical Technology Co., Ltd.;

[0057] C5: N-Phenyloglycine, Shanghai Maclean Biochemical Technology Co., Ltd.;

[0058] Additive D:

[0059] D1: Malachite Green, Shanghai Maclean Biotechnology Co., Ltd.;

[0060] D2: Leuco Crystal Violet, Shanghai Maclean Biochemical Technology Co., Ltd.;

[0061] D3: p-Toluenesulfonamide, Shanghai Tixi Chemical Trading Co., Ltd.;

[0062] According to the weight proportions of each component of the dry film resist in Table 1, mix them in the specified ratio, add a certain amount of acetone, and then stir thoroughly until completely dissolved to prepare a resist solution with a solid content of 42%. Use a coating machine to evenly coat the solution onto the surface of a 15μm thick PET support film, and bake it in a 95℃ oven for 6 minutes to form a 25μm thick photosensitive resin layer, which appears blue-green under yellow light. Then, a 18μm thick polyethylene film protective layer is laminated onto its surface to obtain a three-layer dry film laminate.

[0063] Table 1

[0064]

[0065]

[0066] Example 8

[0067] The difference from Example 3 is that the weight of the alkali-soluble resin is 69.85 parts, the weight of the photopolymerizable monomer is 30 parts, the weight of the photoinitiator is 0.1 parts, and the weight of the additive is 0.05 parts, finally obtaining a dry film laminate.

[0068] Example 9

[0069] The difference from Example 3 is that the weight of the alkali-soluble resin is 42 parts, the weight of the photopolymerizable monomer is 50 parts, the weight of the photoinitiator is 4.0 parts, and the weight of the additive is 4.0 parts, finally obtaining a dry film laminate.

[0070] Example 10

[0071] The difference from Example 3 is that the weight percentage of 2,4,6-trienylpropoxy-1,3,5-triazine is 10.41 parts, the mass percentage of 2,4,6-trienylpropoxy-1,3,5-triazine in the photopolymerizable monomer is 28 wt%, the weight percentage of bis(3-mercaptopropionic acid)ethylene glycol is 2.59 parts, and the mass percentage of bis(3-mercaptopropionic acid)ethylene glycol in the photopolymerizable monomer is 7 wt%, finally yielding a dry film laminate.

[0072] Example 11

[0073] The difference from Example 3 is that (10) the weight of bisphenol A di(meth)acrylate oxyacetate is 21 parts and (6) the weight of trimethylolpropane tri(meth)acrylate oxyacetate is 3 parts, and finally a dry film laminate is obtained.

[0074] [Screen protector]

[0075] The copper-clad laminate is polished using a grinding machine, washed with water, and dried to obtain a bright and fresh copper surface. The laminating machine is set with a pressure roller temperature of 110℃, a conveying speed of 1.5m / min, and heat lamination under standard pressure.

[0076]

exposure

[0077] After coating, the samples were allowed to stand for at least 15 minutes, then exposed using an Orbold Nuvogo 80F laser direct imaging (LDI) exposure machine. Photosensitivity was tested using a Stouffer 41-step exposure scale, with the exposure grid number controlled between 14 and 20 divisions and the exposure energy between 10 and 40 mJ / cm². 2 .

[0078]

development

[0079] After exposure, the sample should be allowed to stand for at least 15 minutes. The development temperature is 30℃, and the pressure is 1.2 kg / cm². 2 The developer is a 1 wt% sodium carbonate aqueous solution, and the development time is 1.5 to 2.0 times the minimum development time. After development, the product is washed with water and dried.

[0080] [Removal of film]

[0081] The stripping solution was NaOH, concentration 3.0 wt%, temperature 50℃, and developing pressure 1.2 kg / cm². 2 The film removal time is 1.5 to 2.0 times the minimum film removal time. After film removal, wash with water and dry.

[0082] [Resolution Evaluation]

[0083] Exposure is performed using a mask with a wiring pattern having an exposed portion and an unexposed portion with a width of n:n (n is 10 to 100 μm). After development at 1.5 times the minimum development time, the minimum mask width at which the cured resist lines normally form is taken as the resolution value, and observation is performed using a two-dimensional imager or a scanning electron microscope (SEM).

[0084] [Evaluation of Adhesion]

[0085] Photosensitive dry film resist is laminated onto a copper plate by hot pressing. A mask with a wiring pattern having an exposed and unexposed portion and a width of n:400 (n is 10~100μm) is used for exposure. After development at 1.5 times the minimum development time, the minimum mask width at which the cured resist lines are formed is taken as the adhesion value, and the results are observed using a two-dimensional image analyzer or a scanning electron microscope (SEM).

[0086] Conduct observations.

[0087] [Electroplating Resistance Evaluation]

[0088] At 40℃, the developed substrate was immersed in a 10% acidic degreasing solution for 10 minutes, rinsed with water for 5 minutes, micro-etched with sodium persulfate, and then immersed in a 10% sulfuric acid aqueous solution at room temperature for 2 minutes. The substrate was then immersed in a pre-prepared copper plating solution at a current density of 2 ASD for 70 minutes; followed by immersion in a 10% sulfuric acid aqueous solution at room temperature for 2 minutes, and then immersed in a pre-prepared tin plating solution at a current density of 1 ASD for 10 minutes. After rinsing with water to remove the cured dry film, the appearance of the sample was observed using a 500x high-resolution scanning electron microscope to check for any plating defects.

[0089] [Evaluation of film removal speed]

[0090] Take one substrate after lamination, exposure, and development, cut it into a 4*5cm square, and place it in a beaker containing 100mL of stripping solution (3wt% concentration, 50℃). Stir magnetically for 1 minute, and record the time when the dry film completely peels off. The stripping speed is evaluated by testing the stripping time; the shorter the stripping time, the faster the stripping speed.

[0091] [Evaluation of the size of the film removal fragments]

[0092] Take one substrate after lamination, exposure, and development, cut it into a 4*5cm square, and place it in a beaker containing 100mL of stripping solution (3wt% concentration, 50℃). Stir magnetically for 1 minute, then observe the size of the stripped fragments. Good: fragment size 5-15mm; Average: fragment size 20-30mm; Poor: fragment size greater than 30mm or less than 5mm.

[0093] [Evaluation of storage stability]

[0094] The slit photosensitive dry film rolls were placed in a constant temperature and humidity chamber at 23℃ and 60% relative humidity for accelerated testing, and the amount of adhesive overflow on the sides of the dry film rolls was observed periodically. ◎: No adhesive overflow after 45 days, indicating excellent storage stability; ○: No adhesive overflow after 30 days, indicating good storage stability;

[0095] Δ: No resin flow after 21 days; slight resin flow occurs after 21 days, indicating average storage stability; ×: Resin flow occurs after 14 days, indicating insufficient storage stability.

[0096] The samples prepared by the above-mentioned methods (including film application, exposure, development, electroplating, and film removal) were evaluated. The evaluation results of Examples 1-11 and Comparative Examples 1 and 2 are shown in Table 2.

[0097] Table 2

[0098]

[0099] By comparing Examples 1-11 with Comparative Examples 1-2, it can be found that Examples 1-11 yield resist laminates with excellent resolution, adhesion, stripping speed, stripping fragment size, electroplating resistance, and storage stability. Comparative Example 1, while exhibiting good stripping performance, is lacking in resolution and adhesion, and its electroplating resistance is only average. Comparative Example 2, being a resist laminate without the introduction of a mercapto-olefin reaction system, shows poor electroplating resistance in addition to its average resolution, adhesion, and stripping performance.

[0100] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0101] This application introduces allyl and mercapto compounds into a photosensitive resin composition. The alkenyl group in the allyl compound can undergo an addition polymerization reaction with the mercapto group in the mercapto compound. Since the polymerization reaction of the mercapto-alkene reaction system lasts longer than the free radical double bond copolymerization reaction of other photopolymerizable monomers, it helps to achieve more uniform crosslinking of the prepared photosensitive resin after exposure. This alleviates the shrinkage stress during polymerization, resulting in a photosensitive resin with low polymerization shrinkage stress. The photosensitive resin with low polymerization shrinkage stress exhibits better adhesion during the bonding process with copper substrates. The introduction of the mercapto-alkene reaction system improves the bonding strength between the photosensitive resin and the copper substrate, thus reducing the risk of abnormalities such as plating overflow in the pattern electroplating process, thereby improving product yield. The photosensitive resin composition of this invention incorporates a photo- or thermally decomposable initiator, which can initiate a partial reaction of the mercapto-alkene reaction system during the drying process. This helps to provide a slightly crosslinked network support for the photosensitive resin, thereby reducing the risk of resin run-through and improving the storage stability of the photosensitive resin. If the mass percentage of thiol compounds in the photopolymerizable monomers is too low, it will be detrimental to improving the peeling performance, electroplating resistance, and storage stability of the photosensitive resin. If the mass percentage of thiol compounds in the photopolymerizable monomers is too high, it will be detrimental to improving the resolution and adhesion performance of the photosensitive resin. It is preferable to control the mass percentage of thiol compounds in the photopolymerizable monomers within the above-mentioned range, which will help improve the overall performance of the photosensitive resin, including its resolution, adhesion, peeling performance, electroplating resistance, and storage stability.

[0102] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A photosensitive resin composition, characterized in that, The photosensitive resin composition comprises, by weight parts: 50-70 parts of alkali-soluble resin; 30-50 parts of photopolymerizable monomer; and 0.1 to 4.0 parts of photoinitiator; wherein, The photopolymerizable monomer comprises an allyl compound, an unsaturated fatty acid, and a thiol compound, wherein the thiol compound comprises 7 wt% to 22 wt% of the photopolymerizable monomer. The unsaturated fatty acid is selected from any one or more of 9-octadecenoic acid, 9,12-octadecadienoic acid, 9,12,15-octadectrienoic acid, 9,11,13-octadectrienoic acid, and 12-hydroxy-9-octadecenoic acid.

2. The photosensitive resin composition according to claim 1, characterized in that, The allyl compound comprises 5 wt% to 14 wt% of the photopolymerizable monomer; and / or, the thiol compound comprises 8 wt% to 22 wt% of the photopolymerizable monomer.

3. The photosensitive resin composition according to claim 1, characterized in that, The mass ratio of the allyl compound to the mercapto compound is 0.625 to 1:

1.

4. The photosensitive resin composition according to claim 1, characterized in that, The allyl compound is selected from any one or more of allyl methacrylate, diallyl carbonate, allyl benzyl ether, 2,4,6-trienylpropoxy-1,3,5-triazine, tert-butoxy-N-carbamate, diethyl allyl malonate, eugenol and its derivatives, safrole and its derivatives, and artemisia argyi and its derivatives. And / or, the thiol compound is selected from any one or more of methanethiol, ethanethiol, 1-propanethiol, n-butanethiol, dodecanethiol, ethylenedithiol, 1,3-propanedithiol, 2,3-dimercaptopropanol, hexanedithiol, 1,4-dimethylbenzylthiophenol, tris(2-hydroxyethyl)isocyanurate tris(mercaptopropionate), diethanolamine tris(mercaptopropionate), bis(3-mercaptopropionic acid) ethylene glycol, hydroxymethylpropane tris(3-mercaptopropionate), pentaerythritol tetras(3-mercaptopropionate), benzylmercaptopropionate, cysteine, and bis(3-mercaptopropionic acid) ethylene glycol.

5. The photosensitive resin composition according to any one of claims 1 to 4, characterized in that, The photopolymerizable monomer includes acrylate compounds; and / or, the unsaturated fatty acid accounts for 1 wt% to 5 wt% of the mass of the photopolymerizable monomer.

6. The photosensitive resin composition according to claim 5, characterized in that, The acrylate compound accounts for 65 wt% to 86 wt% of the mass of the photopolymerizable monomer.

7. The photosensitive resin composition according to claim 5, characterized in that, The photopolymerizable monomer includes the acrylate compound and the unsaturated fatty acid, and the mass ratio of the acrylate compound to the unsaturated fatty acid is 12.5~26:

1.

8. The photosensitive resin composition according to claim 5, characterized in that, The acrylate compounds are selected from any one or more of the following: lauryl acrylate, octadecyl acrylate, nonylphenol acrylate, ethoxylated (propoxylated) nonylphenol acrylate, tetrahydrofuran methyl acrylate, bisphenol A dimethacrylate, ethoxylated (propoxylated) bisphenol A dimethacrylate, polyethylene glycol (propylene glycol) dimethacrylate, ethoxylated (propoxylated) neopentyl glycol diacrylate, trimethylolpropane trimethacrylate, ethoxylated (propoxylated) trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

9. The photosensitive resin composition according to claim 8, characterized in that, The acrylate compound is a combination of bisphenol A dimethacrylate and trimethylolpropane trimethacrylate, and the mass ratio of bisphenol A dimethacrylate to trimethylolpropane trimethacrylate is 12~20:5~16.

10. The photosensitive resin composition according to any one of claims 1 to 4, characterized in that, The acid value of the alkali-soluble resin is 120~250 mg KOH / g; and / or, the weight-average molecular weight of the alkali-soluble resin is 20,000~120,000; and / or, the polydispersity index of the alkali-soluble resin is 1.3~2.

5. And / or, the alkali-soluble resin is prepared from a polymeric monomer selected from any one or more of the following: (meth)acrylic acid, (meth)methyl acrylate, (meth)ethyl acrylate, (meth)propyl acrylate, (meth)butyl acrylate, (meth)cyclohexyl acrylate, (meth)isooctyl acrylate, (meth)hydroxyethyl acrylate, (meth)hydroxypropyl acrylate, glycidyl methacrylate, (meth)allyl acrylate, polyethylene (or propylene) glycol (meth)acrylate, styrene and its derivatives, (meth)benzyl acrylate, (meth)p-oxyphenyl benzyl acrylate, (meth)phenoxyethyl acrylate, (meth)o-phenylphenoxyethyl acrylate, (meth)adamantane acrylate, (meth)cyclopentadienyl acrylate, and (meth)isobornene acrylate.

11. The photosensitive resin composition according to claim 10, characterized in that, The polymer monomer is selected from any one or more of methacrylic acid, methyl methacrylate, butyl acrylate, styrene, and butyl methacrylate.

12. The photosensitive resin composition according to any one of claims 1 to 4, characterized in that, The photoinitiator is selected from any one or more of the following: azo compounds, peroxide compounds, α-hydroxy ketone compounds, α-amino ketone compounds, acylphosphine compounds, α-oxyacyloxime ester compounds, hexaaryl diimidazole derivatives, acridine derivatives, benzoyl ether, benzophenone and its derivatives, thioxanthone derivatives, anthraquinone and its derivatives, aromatic diazonium salts, iodonium salts, thiodonium salts, aromatic ferrocene salts, titanoceramsite photoinitiators, and nonionic acid-producing agents.

13. The photosensitive resin composition according to claim 12, characterized in that, The photoinitiator is selected from any one or more of 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-bis(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycine.

14. The photosensitive resin composition according to claim 13, characterized in that, The photoinitiator is a combination of 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-bis(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycine, wherein the mass ratio of 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 4,4-bis(N,N'-dimethylamino)benzophenone, azobisisobutyronitrile, and N-phenylglycine is 1.5~1.8:0.4~0.7:0.05~0.1:0.05:0.

1.

15. A resist ink, characterized in that, The resist ink contains the photosensitive resin composition according to any one of claims 1 to 14.

16. A photoresist laminate, comprising a support layer, a photosensitive resin layer, and a protective layer stacked sequentially, characterized in that, The photosensitive resin layer is prepared from the photosensitive resin composition of any one of claims 1 to 14 or the resist ink of claim 15.

17. The application of the resist laminate according to claim 16 on a circuit board.

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