Photosensitive dry film, photosensitive resin composition, cured film and printed circuit board

Abstract

The invention discloses a photosensitive dry film, a photosensitive resin composition, a cured film and a printed circuit board, and belongs to the technical field of materials. The ratio of the thickness of the photosensitive dry film to the median particle size D50 of the inorganic filler is (4-8): 1, and the ratio of the thickness of the photosensitive dry film to the maximum particle size D100 of the inorganic filler is larger than 2.8. Through the design, the barrier is arranged in the permeation and diffusion path of the small molecules and / or the permeation and diffusion path is prolonged, so that the time for the small molecules to reach a dry film and a copper interface is prolonged, the influence of small molecule substances on interface copper oxide is reduced or inhibited, and the interlayer adhesive force, chemical resistance and reliability are improved.

Description

Technical Field

[0001] The present application relates to the field of material technology, and in particular to a photosensitive dry film, a photosensitive resin composition, a cured film and a printed circuit board. Background Art

[0002] With the thinning and modularization of PCB (printed circuit board), the corresponding circuit design spacing is getting smaller and smaller, and the pattern is getting more and more refined. The performance requirements of solder mask materials are getting higher and higher. It is required that the insulation protection function of solder mask materials should not be reduced while thinning. Thin solder mask materials are difficult to resist the penetration of small molecules from the outside. Small molecules such as water vapor, acid and alkali can easily diffuse in the solder mask body and reach the interface between the solder mask and copper in a short time, which aggravates the erosion and damage of the interface, thereby weakening the insulation protection function of the solder mask on copper. It is very easy to have problems such as reduced insulation and short circuit, which affects the normal use and service life of the final device. At this stage, the hard indicators proposed by high-end boards for solder mask materials are low film thickness, good acid resistance, resistance to various surface treatments (including nickel-gold, nickel-palladium-gold, etc.), and high reliability (including PCT, HAST aging, ion migration, etc.).

[0003] Therefore, there is an urgent need to study a solder resist material with good chemical resistance that can solve the above problems. Summary of the invention

[0004] The main purpose of the present application is to provide a photosensitive dry film, a photosensitive resin composition, a cured film and a printed circuit board to solve the problem in the prior art that the chemical resistance of the PCB solder mask layer is poor and cannot provide good insulation protection for the copper base layer.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a photosensitive dry film is provided, which includes a base film and an inorganic filler distributed in the base film; wherein the ratio of the thickness of the photosensitive dry film to the median particle size D50 of the inorganic filler is (4 to 8): 1, and the ratio of the thickness of the photosensitive dry film to the maximum particle size D100 of the inorganic filler is greater than 2.8.

[0006] Furthermore, the ratio of the thickness of the photosensitive dry film to the median particle size D50 of the inorganic filler is (5-8):1.

[0007] Furthermore, the ratio of the thickness of the photosensitive dry film to the maximum particle size D100 of the inorganic filler is greater than or equal to 4, and further is 4-7.

[0008] Furthermore, the thickness of the photosensitive dry film is less than or equal to 100 μm; further, 10 to 50 μm; further, 15 to 40 μm; and further, 20 to 40 μm.

[0009] Further, the median particle size D50 of the inorganic filler is 2.5 to 8.0 μm, and the maximum particle size D100 is less than or equal to 10 μm.

[0010] Further, the inorganic filler includes inorganic filler I; wherein, inorganic filler I is selected from at least one of titanium dioxide, barium sulfate, silicon dioxide, and aluminum hydroxide.

[0011] Further, the median particle size D50 of inorganic filler I is 2.5 to 8.0 μm, and the maximum particle size D100 is less than or equal to 10 μm.

[0012] Further, the inorganic filler further includes inorganic filler II; wherein, inorganic filler II is flaky mica powder and / or flaky talc powder.

[0013] Further, the median particle size D50 of inorganic filler II is 1 to 10 μm, and the maximum particle size D100 is less than or equal to 15 μm.

[0014] Further, the median particle size D50 of inorganic filler II is 3 to 7 μm; and the maximum particle size D100 is less than or equal to 10 μm.

[0015] Further, the median particle size D50 of inorganic filler II is 3 to 7 μm, and the maximum particle size D100 is 5 to 10 μm.

[0016] Further, the thickness of inorganic filler II is less than or equal to 1.5 μm.

[0017] Further, the thickness of inorganic filler II is 0.5 to 1.0 μm.

[0018] Further, inorganic filler II is distributed in the base film substantially parallel to the surface of the base film.

[0019] Further, the raw material of the base film includes an alkali-soluble vinyl resin.

[0020] Further, the alkali-soluble vinyl resin is selected from at least one of carboxylic acid-modified bisphenol A type epoxy vinyl resin, carboxylic acid-modified bisphenol F type epoxy vinyl resin, carboxylic acid-modified bisphenol S type epoxy vinyl resin, and carboxylic acid-modified phenolic epoxy vinyl resin.

[0021] According to the second aspect of the present application, there is provided a resin composition for preparing the above-mentioned photosensitive dry film, and the raw materials thereof include the following components in parts by weight: 100 parts of alkali-soluble vinyl resin, 10 to 30 parts of active diluent, 20 to 40 parts of thermal curing agent, 0.1 to 5 parts of photoinitiator, 15 to 45 parts of inorganic filler, and 0.1 to 3 parts of antioxidant.

[0022] Furthermore, the inorganic filler includes inorganic filler I; wherein, inorganic filler I is selected from at least one of titanium dioxide, barium sulfate, silicon dioxide, and aluminum hydroxide.

[0023] Furthermore, the morphology of inorganic filler I includes at least one of amorphous, angular, and spherical.

[0024] Furthermore, inorganic filler I is a solid filler and / or a hollow filler; more preferably, it is a solid filler.

[0025] Furthermore, the median particle size D50 of inorganic filler I is 2.5 - 8.0 μm, and the maximum particle size D100 is less than or equal to 10 μm.

[0026] Furthermore, the inorganic filler also includes inorganic filler II; wherein, inorganic filler II is flaky mica powder and / or flaky talc powder.

[0027] Furthermore, the median particle size D50 of inorganic filler II is 1 - 10 μm, and the maximum particle size D100 is less than or equal to 15 μm.

[0028] Furthermore, the median particle size D50 of inorganic filler II is 3 - 7 μm, and the maximum particle size D100 is less than or equal to 10 μm.

[0029] Furthermore, the thickness of inorganic filler II is less than or equal to 1.5 μm.

[0030] Furthermore, the thickness of inorganic filler II is 0.5 - 1.0 μm.

[0031] Furthermore, the weight ratio of inorganic filler I to inorganic filler II is (11 - 17):(3 - 9).

[0032] Furthermore, inorganic filler I and / or inorganic filler II is surface - modified with a modifying compound; wherein, the modifying compound is an epoxy compound or an acrylic acid - type compound.

[0033] Furthermore, the alkali - soluble vinyl resin is selected from at least one of carboxylic acid - modified bisphenol A - type epoxy vinyl resin, carboxylic acid - modified bisphenol F - type epoxy vinyl resin, carboxylic acid - modified bisphenol S - type epoxy vinyl resin, and carboxylic acid - modified phenolic epoxy vinyl resin.

[0034] Furthermore, the acid value of the alkali - soluble vinyl resin is 50 - 100 mg KOH / g, more preferably 80 - 100 mgKOH / g.

[0035] Furthermore, the reactive diluent is selected from at least one of monofunctional reactive diluents, bifunctional reactive diluents, trifunctional reactive diluents, and high - functional reactive diluents.

[0036] Furthermore, the monofunctional reactive diluent is selected from at least one of aromatic (meth)acrylate, alkoxydodecyl (meth)acrylate, alicyclic (meth)acrylate resin, 2-(2-ethoxyethoxy)ethyl acrylate, octadecyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dodecyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, alicyclic (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, caprolactone (meth)acrylate, (4-)ethoxylated nonylphenol (meth)acrylate, isobornyl (meth)acrylate, trimethylolpropane formal (meth)acrylate, methoxypolyethylene glycol mono(meth)acrylate, methoxypolyethylene glycol (500) mono(meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, alkoxylated nonylphenol (meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 4-hydroxybutyl vinyl ether, glycerol carbonate allyl ether, and dodecyl vinyl ether.

[0037] Furthermore, the difunctional reactive diluent is selected from at least one of cyclohexanedimethanol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, alkoxylated neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol (200) di(meth)acrylate, triethylene glycol di(meth) vinyl ether, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, 1,4-cyclohexanedimethanol di(meth) vinyl ether, ethylene glycol phthalate di(meth)acrylate, pentanediol dimethacrylate, polyethylene glycol (400) di(meth)acrylate, polyethylene glycol (600) di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, dipropylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, and propoxylated neopentyl glycol di(meth)acrylate.

[0038] Furthermore, the trifunctional active diluent is selected from at least one of tris(2-hydroxyethyl)isocyanuric acid tris(meth)acrylate, pentaerythritol tris(meth)acrylate, ethoxylated trimethylolpropane tris(meth)acrylate, propoxylated trimethylolpropane tris(meth)acrylate, ethoxylated trimethylolpropane tris(meth)acrylate, and propoxylated trimethylolpropane tris(meth)acrylate, etc.

[0039] Furthermore, the high-functional active diluent is selected from at least one of di-trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0040] Furthermore, the thermosetting agent includes at least one of blocked isocyanate compounds, amino resins, benzoxazine resins, carbodiimide resins, maleimide compounds, cyclic carbonate compounds, epoxy compounds, polyfunctional oxetane compounds, and cyclic sulfur resins.

[0041] Furthermore, the epoxy compound is selected from at least one of bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, hydrogenated bisphenol A type epoxy resins, glycidylamine type epoxy resins, hydantoin type epoxy resins, alicyclic epoxy resins, brominated epoxy resins, hydroquinone type epoxy resins, biphenyl type crystalline epoxy resins, naphthalene type epoxy resins, thioether type epoxy resins, o-cresol novolac type epoxy resins, biphenol novolac type epoxy resins, triphenylolmethane type epoxy resins, biphenol type epoxy resins, bisphenol A novolac type epoxy resins, tetramethylol ethane type epoxy resins, heterocyclic epoxy resins, diglycidyl phthalate resins, tetraglycidyl xylene benzoyl ethane resins, dicyclopentadiene skeleton glycidyl methacrylate copolymer epoxy resins, cyclohexyl maleimide and glycidyl methacrylate copolymer epoxy resins, epoxy modified polybutadiene rubber derivatives, and CTBN-modified epoxy resins.

[0042] Furthermore, the epoxy equivalent of the epoxy compound is 100 - 400 g / eq.

[0043] Further, the polyfunctional oxetane compound is selected from at least one of bis[(3-methyl-3-oxetanylmethoxy)methyl] ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl] ether, 1,4-bis[(3-methyl-3-oxetanylmethoxy)methyl] benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, and their oligomers or copolymers, oxetanol, novolac resin, poly(p-hydroxystyrene), Cardo bisphenol, calixarene, and calixphthalene.

[0044] Further, the amino resin is selected from at least one of hydroxymethyl melamine compounds, hydroxymethyl benzoguanamine compounds, hydroxymethyl glycoluril compounds, and hydroxymethyl urea compounds.

[0045] Further, the photoinitiator includes a cleavage-type free radical polymerization photoinitiator, a hydrogen abstraction-type free radical polymerization photoinitiator, and a cationic polymerization photoinitiator.

[0046] Further, the cleavage-type free radical polymerization photoinitiator is selected from at least one of α-hydroxy ketone derivatives, α-amino ketone derivatives, acylphosphine oxides, and oxime esters.

[0047] Further, the α-hydroxy ketone derivatives are selected from at least one of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 1-[4-(2-hydroxy)phenyl]-3-hydroxy-2-methyl-1-propanone-1-one.

[0048] Further, the α-amino ketone derivatives are selected from at least one of 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, and 2-p-methylbenzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone.

[0049] Further, the acylphosphine oxides are selected from at least one of 2,4,6-trimethylbenzoyl ethoxyphenyl phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide.

[0050] Further, the oxime esters are 1,8-bis[9-ethyl-6-nitro-9H-carbazol-3-yl]-, 1,8-bis(O-acetyl oxime) and / or 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime).

[0051] Furthermore, the hydrogen abstraction type free radical initiator is selected from at least one of benzophenone and its derivatives, thioxanthone and its derivatives, anthraquinone and its derivatives, or titanocene.

[0052] Furthermore, the thioxanthone is selected from at least one of 2,4 - diethylthioxanthone, isopropylthioxanthone, and 1 - chloro - 4 - propoxythioxanthone.

[0053] Furthermore, the titanocene is selected from at least one of bis(cyclopentadienyl)-diphenyltitanium, bis(cyclopentadienyl)-dichlorotitanium, bis(cyclopentadienyl)-bis(2,3,4,5,6 - pentafluorophenyl)titanium, and bis(cyclopentadienyl)-bis(2,6 - difluoro - 3-(pyrrol - 1 - yl)phenyl)titanium.

[0054] Furthermore, the cationic polymerization photoinitiator is selected from at least one of aryl diazonium salts, diaryliodonium salts, triarylsulfonium salts, areneiron salts, and cumene iron hexafluorophosphate.

[0055] Furthermore, the cationic polymerization photoinitiator is selected from at least one of dodecylbenzenesulfonium iodide, long - chain alkoxydiphenyliodonium salts, phenylthiophenyldiphenylsulfonium salts, diphenylsulfonium hexafluoroantimonate, UV16976, UV16992, and UV261.

[0056] Furthermore, the antioxidant includes Antioxidant I; wherein, Antioxidant I includes aromatic amine compounds and / or hindered phenol compounds.

[0057] Furthermore, Antioxidant I is selected from at least one of 2 - tert - butylhydroquinone, hydroquinone monomethyl ether, pentaerythritol tetra(3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)acrylate), 2,6 - di - tert - butyl - p - cresol, 1,3,5 - trimethyl - 2,4,6 - tris(3,5 - di - tert - butyl - 4 - hydroxybenzyl)benzene, p - methoxyphenol, and phenothiazine.

[0058] Furthermore, the antioxidant further includes Antioxidant II; wherein, Antioxidant II is a phosphorus - containing organic compound and / or a sulfur - containing organic compound.

[0059] Furthermore, Antioxidant II is selected from at least one of triphenyl phosphite, pentaerythritol tetra(lauryl thioacrylate), and dilauryl thiodipropionate.

[0060] According to the third aspect, a cured film is provided. The cured film is obtained by subjecting a photosensitive dry film to photo - curing and then thermal - curing in sequence; wherein, the photosensitive dry film is the above - mentioned photosensitive dry film or the photosensitive dry film formed after drying the above - mentioned resin composition.

[0061] According to a fourth aspect, a printed circuit board is provided, which includes a copper plate and a cured film attached to the surface of the copper plate; wherein, the cured film is the above-mentioned cured film.

[0062] Applying the technical solution of the present application, a photosensitive dry film and its resin composition are provided; considering from the perspective of the thickness of the photosensitive dry film and the particle size of the filler particles, the ratio of the thickness of the dry film to the median particle size D50 of the inorganic filler is defined as (4-8):1, and the ratio of the dry film thickness to D100 is above 2.8; thereby setting obstacles and / or extending the penetration and diffusion path in the small molecule penetration and diffusion path, and then extending the time for small molecules to reach the interface between the dry film and copper, so as to reduce or inhibit the influence of small molecule substances on the interfacial copper oxide, and further improve the interlayer adhesion. Detailed implementation manners

[0063] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the embodiments.

[0064] When studying the solder mask layer material of the PCB in the present application, it is found that the acidic solution or the electroless nickel immersion gold or nickel palladium immersion gold solution is an aqueous solution system composed of small molecule substances. Small molecule substances such as sulfuric acid, hydrochloric acid, and phosphoric acid will slowly penetrate through the surface of the dry film into the body and then reach the interface between the dry film and the bare copper. The acidic small molecules that penetrate and diffuse in will etch away the copper oxide at the interface between the dry film and the copper, resulting in a reduction in the contact points between the two, and the intuitive manifestation is a decrease in adhesion; to solve this problem, the present application finds that if obstacles are set and / or the penetration and diffusion path is extended in the penetration and diffusion path of acidic small molecule substances, the time for acidic small molecule substances to reach the interface between the dry film and the copper will be extended. Within the same time, the etching amount of acidic small molecules on copper oxide is relatively low or almost no etching, so that the chemical resistance of the dry film can be improved; the above-mentioned chemical resistance specifically refers to acid resistance, electroless nickel electroless palladium immersion gold (ENEPIG), and electroless nickel immersion gold (ENIG).

[0065] Therefore, the present application provides a photosensitive dry film, which includes a base film and inorganic fillers distributed in the base film; wherein, the ratio of the thickness of the photosensitive dry film to the median particle size D50 of the inorganic filler is (4-8):1, and the ratio of the thickness of the photosensitive dry film to the maximum particle size D100 of the inorganic filler is greater than 2.8.

[0066] The above photosensitive dry film of the present application has the property of curing into a film under conditions such as light irradiation or heating. This photosensitive dry film refers to a dry film that has not undergone photo-curing and thermal curing. Among them, the numerical ratio of the thickness of the dry film to the particle size of the inorganic filler is any value among 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 or the range value between any two of them. The numerical ratio of the dry film thickness of the present application to the maximum particle size D100 of the inorganic filler is greater than 2.8, and the ratio of the dry film thickness to D100 is less than the ratio of the dry film thickness to D50.

[0067] By controlling the optimal proportional relationships between the dry film thickness and the inorganic fillers D50 and D100 respectively, the present application realizes reasonably setting obstacles and / or extending the penetration and diffusion path in the small molecule penetration and diffusion path, significantly prolongs the time for small molecules to reach the paint film and copper interface, thereby reducing or inhibiting the etching effect of acidic small molecule substances on the interfacial copper oxide, and significantly improving the chemical resistance of the dry film, such as acid resistance, electroless nickel immersion palladium immersion gold (ENEPIG), electroless nickel immersion gold (ENIG); and further improving the interlayer adhesion.

[0068] In some embodiments, the ratio of the thickness of the photosensitive dry film to the median particle size D50 of the inorganic filler is (5 - 8):1. By further optimizing the proportional relationship between the dry film thickness and D50, that is, adjusting the more suitable median particle size D50 of the inorganic filler, obstacles are set more reasonably and / or the penetration and diffusion path is extended in the acidic small molecule penetration and diffusion path, further prolonging the time for small molecules to reach the dry film and copper interface, and thus improving the chemical resistance and interlayer adhesion of the dry film.

[0069] In some embodiments, the ratio of the thickness of the photosensitive dry film to the maximum particle size D100 of the inorganic filler is greater than or equal to 4; for example, any value among 4, 5, 6, 7, 8, 9, 10 or the range value between any two of them; for another example, 4 - 7. By controlling the ratio of the dry film to D100 within the above preferred range, that is, appropriately controlling the maximum particle size D100, the inorganic filler particles are basically uniform, improving the dispersibility of the filler in the base film, which is beneficial to improving the chemical resistance and interlayer adhesion of the dry film.

[0070] In some embodiments, the thickness of the photosensitive dry film is less than or equal to 100 μm; further preferably 10 - 50 μm; more preferably 15 - 40 μm; still more preferably 20 - 40 μm; for example, any value among 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 μm or a range value between any two of them; the median particle size D50 of the inorganic filler is 2.5 - 8.0 μm, and the maximum particle size D100 is less than or equal to 10 μm. For example, D50 is any value among 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 or a range value between any two of them; for another example, D100 is any value among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 μm or a range value between any two of them; while further thinning the dry film thickness to meet the usage requirements in this application, by controlling the particle sizes of the inorganic filler D50 and D100, a suitable barrier and molecular penetration path are formed in the dry film, which can extend the time for small molecules to reach the interface between the dry film and copper, thereby improving the chemical resistance and interlayer adhesion of the dry film.

[0071] In some embodiments, the inorganic filler includes inorganic filler I; wherein, inorganic filler I is selected from at least one of titanium dioxide, barium sulfate, silicon dioxide, and aluminum hydroxide; the median particle size D50 of inorganic filler I is 2.5 - 8.0 μm, and the maximum particle size D100 is less than or equal to 10 μm; inorganic filler I is uniformly distributed in the base film. By selecting the above inorganic filler I, adjusting more suitable D50, D100, and the uniform distribution form, the distribution uniformity of the filler in the dry film can be improved, and a better path that can hinder the penetration of acidic small molecules to the copper interface can be further designed, thereby improving the chemical resistance and adhesion of the dry film.

[0072] In some embodiments, the dry film thickness is 20 μm, the median particle size D50 of the inorganic filler is 2.5 - 4.0 μm, and the maximum particle size D100 is less than or equal to 5 μm; or, the dry film thickness is 40 μm, the median particle size D50 of the inorganic filler is 5 - 8 μm, and the maximum particle size D100 is less than or equal to 10 μm.

[0073] In some embodiments, in addition to the necessary addition of inorganic filler I, the inorganic filler of this application can also add inorganic filler II; wherein, inorganic filler II is flaky mica powder and / or flaky talc powder. In addition to adding particulate inorganic filler I in the base film, in order to further improve the effect of hindering the penetration of substances such as acidic small molecules to the copper interface, thin flaky inorganic filler II can also be added to the base film, such as two-dimensional flaky fillers, which can be flaky mica powder or flaky talc powder; among them, mica powder is a layered silicate, and its structure is composed of a double silicon-oxygen layer with two layers of silicon-oxygen tetrahedrons sandwiching a layer of aluminum-oxygen octahedron, which dissociates completely and can be split into extremely thin flakes, with the flake thickness reaching less than 1.5 μm, and it has a large aspect ratio. Generally, the chemical composition is SiO2 : 43.13 - 49.04%, Al 2 O 3 : 27.93 - 37.44%, K 2 O + NaO: 9 - 11%, H 2 O: 4.13 - 6.12%. It is a flaky fine powder product with a silver - white to gray appearance. This flaky filler II can form a substantially parallel orientation arrangement in the solder mask layer. Such layer - by - layer arrangement has its orientation exactly perpendicular to the direction in which corrosive substances penetrate the paint film, which can give full play to the barrier effect of its flaky material, strongly block the penetration of water and other corrosive substances in the dry film. When using high - quality mica powder, the time for water and other corrosive substances to penetrate the dry film can generally be extended by 3 times. It has good chemical stability and can improve the heat resistance, weather resistance, anti - powdering property and durability of the solder mask layer.

[0074] The median particle size D50 of the mica powder is 1 - 10 μm, further 3 - 7 μm, such as any value among 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or the range value between any two of them. The maximum particle size D100 is 15 μm or less, further 10 μm or less, and still further 5 - 10 μm, such as any value among 2, 3, 4, 5, 6, 7, 8, 9, 10 μm or the range value between any two of them. The flake thickness is less than or equal to 1.5 μm, further less than or equal to 1.0 μm, and still further 0.5 - 1.0 μm; such as any value among 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5 μm or the range value between any two of them. For another example, filler II can select the material with the model BT - 30 from Chuzhou Anhui Silk New Materials Co., Ltd. If the D50 and D100 of the above - mentioned flaky filler are too large, it will mainly affect the PCT. It is not easy to disperse when it is too large, which will instead affect the packing tightness of various fillers, the PCT will decrease, and the nickel - gold plating resistance will become worse; if it is too small, the barrier effect of the flakes is not significant and the PCT is a bit worse; if the thickness is too large, the dispersion effect is not good, which is also reflected in the nickel - gold plating resistance and PCT. In this application, by adding the above - mentioned inorganic filler I and inorganic filler II in specific proportions to the base film, the granular inorganic filler I forms a path with a blocking effect for water or acidic small molecules to penetrate from the outside to the copper interface. On this basis, the flaky inorganic filler II plays a very direct blocking role. The two forms of fillers can cooperate in the base film to fully block the penetration of corrosive substances to the copper interface.

[0075] In some embodiments, the raw materials of the base film include an alkali-soluble vinyl resin; the mass content of the inorganic filler in the resin is 15% to 45%; the specific type of the alkali-soluble vinyl resin is not limited, and common alkali-soluble vinyl resins in the art can be used; for example, at least one of a carboxylic acid-modified bisphenol A type epoxy vinyl resin, a carboxylic acid-modified bisphenol F type epoxy vinyl resin, a carboxylic acid-modified bisphenol S type epoxy vinyl resin, and a carboxylic acid-modified phenolic epoxy vinyl resin. A certain number of double bonds are carried in the selected alkali-soluble vinyl resin, which can undergo a photocuring reaction during the exposure process and be used as a macromolecular photopolymerization monomer; the above-mentioned alkali-soluble vinyl resin is selected as the main material of the base film, and this type of resin has good corrosion resistance and good adhesion to metallic copper; further improving the chemical resistance of the dry film as a whole, such as acid resistance, electroless nickel immersion gold (ENEPIG), and electroless nickel immersion gold (ENIG).

[0076] In some embodiments, the acid value of the alkali-soluble vinyl resin is 50 to 100 mg KOH / g, further 80 to 100 mg KOH / g. By limiting the alkali-soluble vinyl resin to have the above acid value, the development effect can be significantly improved, problems such as poor development and residual glue in the development can be avoided, and problems such as overdevelopment and deviation of line width and line pitch from the standard value can also be avoided, making the dry film have more excellent chemical resistance and reliability.

[0077] According to the second aspect of the present application, a resin composition for preparing the above-mentioned photosensitive dry film is provided, and its raw materials include the following components in parts by weight: 100 parts of an alkali-soluble vinyl resin, 10 to 30 parts of an active diluent, 20 to 40 parts of a thermal curing agent, 0.1 to 5 parts of a photoinitiator, 15 to 45 parts of an inorganic filler, and 0.1 to 3 parts of an antioxidant.

[0078] After the above resin composition of the present application is dried, the above photosensitive dry film can be formed; wherein, the main resin material in the composition is an alkali-soluble vinyl resin, which can be used as a polymerization monomer during later photocuring due to its chemical structure characteristics. This material has good corrosion resistance, strong adhesion to copper, and chemical stability; in addition, the added reactive diluent not only has the function of reducing the viscosity of the resin composition, but also can be used as another polymerization monomer due to its specific chemical structure, which can further increase the later photocuring reaction rate; the added filler is to set up a complex path in the base film that can block the penetration of small molecule corrosives to the copper interface, which can significantly improve the chemical resistance and interlayer adhesion of the film layer; the added antioxidant is to avoid or eliminate the problem of increased small molecule penetration caused by defect points caused by the aging of the resin composition. When only a small amount of antioxidant exists in the polymer system, it can delay or inhibit the progress of the polymer oxidation process, thereby preventing the aging of the polymer and extending its service life. It can eliminate the generated free radicals or promote the decomposition of hydroperoxides to prevent the progress of the chain reaction; the added thermal curing agent is to improve the curing efficiency of the dry film into a solder mask layer during later use; the added photoinitiator is to achieve the effect that the photosensitive dry film can undergo a polymerization reaction after UV irradiation of the resin material to form a cured film; there are no restrictions on the types of the above raw materials in the present application. By adjusting the ratios of each component, a solder mask layer with better chemical resistance, interlayer adhesion, and insulation can be obtained during the later curing process; in particular, by setting the content of the inorganic filler in the alkali-soluble vinyl resin, the chemical resistance of the whole dry film can be further improved; for example, based on 100 parts of the alkali-soluble vinyl resin as the ratio reference, the weight parts of the above reactive diluent can be selected from any value among 10, 15, 20, 25, 30 parts or the range value between any two of them; the weight parts of the above thermal curing agent can be selected from any value among 20, 25, 30, 35, 40 parts or the range value between any two of them; the weight parts of the above photoinitiator can be selected from any value among 0.1, 0.5, 1, 2, 3, 4, 5 parts or the range value between any two of them; the weight parts of the above filler can be selected from any value among 15, 20, 25, 30, 25, 40, 45 parts or the range value between any two of them; the above antioxidant can be selected from any value among 0.1, 0.5, 1, 1.5, 2, 2.5, 3 parts or the range value between any two of them.

[0079] In some embodiments, the inorganic filler includes inorganic filler I; wherein, inorganic filler I is selected from at least one of titanium dioxide, barium sulfate, silicon dioxide, and aluminum hydroxide; further, the morphology of inorganic filler I includes at least one of amorphous, angular, and spherical; furthermore, inorganic filler I is a solid filler and / or a hollow filler; still further, it is a solid filler; furthermore, the median particle size D50 of inorganic filler I is 2.5 to 8.0 μm, and the maximum particle size D100 is less than or equal to 10 μm. By selecting inorganic filler I with the above morphology and type, adjusting more suitable D50, D100, and uniform distribution form, the distribution uniformity of the filler in the dry film can be improved, and further a better path that can hinder the penetration of acidic small molecules to the copper interface can be designed, thereby improving the chemical resistance and adhesion of the dry film.

[0080] In some embodiments, the inorganic filler further includes inorganic filler II; wherein, inorganic filler II is flaky mica powder and / or flaky talc powder, mainly mica powder; further, the median particle size D50 of mica powder is 1 to 10 μm, still further 3 to 7 μm, the thickness is less than or equal to 1.5 μm, and the aspect ratio is large. By adding inorganic filler I and inorganic filler II to the base film, the granular inorganic filler I forms a path with a hindering effect for water or acidic small molecules to penetrate from the outside to the copper interface. On this basis, the flaky inorganic filler II plays another blocking role. The two forms of fillers can fully block the penetration of corrosive substances to the copper interface after synergizing in the base film; by adding flaky inorganic filler II, the chemical resistance time of the dry film can be increased. For example, the PCT tolerance time of the dry film can be increased from 48 h to 96 h. However, if too much flaky filler is added, it may hinder the formation of the penetration path of granular filler I, and thus lead to a decrease in the chemical resistance of the dry film; therefore, the weight ratio of inorganic filler I to inorganic filler II is (11 to 17):(3 to 9); for example, any value among 1, 1.2, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5, 5.5, 6, 6.5 or the range value between any two of them; at this ratio, the two different morphologies of fillers can better achieve the hindering path through synergistic action to improve the chemical resistance of the dry film.

[0081] In some embodiments, inorganic filler I and / or inorganic filler II are surface modified with a modifying compound; wherein, the modifying compound is an epoxy compound or an acrylic compound. By performing the above modification on the inorganic filler, the epoxy group and acrylic acid type have high compatibility with the film system, which can better improve the dispersibility of the filler in the resin, and thus improve the chemical resistance of the dry film.

[0082] In some embodiments, the alkali-soluble vinyl resin is selected from at least one of carboxylic acid-modified bisphenol A epoxy vinyl resin, carboxylic acid-modified bisphenol F epoxy vinyl resin, carboxylic acid-modified bisphenol S epoxy vinyl resin, and carboxylic acid-modified phenolic epoxy vinyl resin. Selecting a certain number of double bonds carried in the above alkali-soluble vinyl resin can cause a photocuring reaction during the exposure process and be used as a macromolecular photopolymerization monomer; selecting the above alkali-soluble vinyl resin as the main material of the base film, this type of resin has good corrosion resistance and good adhesion to metallic copper; further improving the chemical resistance of the whole dry film, such as acid resistance, electroless nickel immersion gold (ENEPIG), and electroless nickel immersion gold (ENIG).

[0083] In some embodiments, in order to further improve the acid and alkali resistance of the dry film, the acid value of the above alkali-soluble vinyl resin is 45 to 120 mg KOH / g, and further 80 to 100 mg KOH / g. For example, the acid value is any value among 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120 mg KOH / g or a range value between any two of them. By limiting the alkali-soluble vinyl resin to have the above acid value, the development effect can be significantly improved, problems such as poor development and residual glue in incomplete development can be avoided, and problems such as overdevelopment and deviation of line width and line pitch from the standard values can also be avoided, making the dry film have more excellent chemical resistance and reliability.

[0084] In some embodiments, the reactive diluent is a reactive diluent with a vinyl functional group, and can be one or two or more of a monofunctional reactive diluent, a bifunctional reactive diluent, a trifunctional reactive diluent, and a high-functional reactive diluent. Selecting the acrylate reactive diluent with the above characteristics can better reduce the viscosity of the resin composition, and has certain polymerizability and can be used as a photopolymerization monomer, which can further improve the later photocuring rate. Further, the above reactive diluent does not contain ethoxy or does not contain propoxy; furthermore, the glass transition temperature of the reactive diluent is -10°C to 80°C.

[0085] For example, the above-mentioned monofunctional reactive diluent can be selected from at least one of aromatic (meth)acrylate, alkoxydodecyl (meth)acrylate, alicyclic (meth)acrylate resin, 2-(2-ethoxyethoxy)ethyl acrylate, octadecyl (meth)acrylate, tetrahydrofuran (meth)acrylate, dodecyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, alicyclic (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, (meth)acrylic acid caprolactone, (4)ethoxylated nonylphenol (meth)acrylate, isobornyl (meth)acrylate, trimethylolpropane formal (meth)acrylate, methoxypolyethylene glycol mono(meth)acrylate, methoxypolyethylene glycol (500) mono(meth)acrylate, alkoxylated tetrahydrofuran (meth)acrylate, alkoxylated nonylphenol (meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 4-hydroxybutyl vinyl ether, glycerol carbonate allyl ether, and dodecyl vinyl ether, etc.

[0086] For example, the above-mentioned bifunctional reactive diluent can be selected from at least one of cyclohexanedimethanol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, alkoxylated neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol (200) di(meth)acrylate, triethylene glycol di(meth) vinyl ether, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, 1,4-cyclohexanedimethanol di(meth) enyl ether, ethylene glycol phthalate di(meth)acrylate, pentanediol di(meth)acrylate methyl ester, polyethylene glycol (400) di(meth)acrylate, polyethylene glycol (600) di(meth)acrylate, (3)ethoxylated bisphenol A di(meth)acrylate, ethoxylated (30) bisphenol A di(meth)acrylate, dipropylene glycol di(meth)acrylate, (4)ethoxylated bisphenol A di(meth)acrylate, (10)ethoxylated bisphenol A di(meth)acrylate, ethoxylated (20) bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, (2)propoxylated neopentyl glycol di(meth)acrylate, etc.

[0087] The trifunctional active diluent can be at least one of tris(2-hydroxyethyl)isocyanurate tris(meth)acrylate, pentaerythritol tris(meth)acrylate, (3)ethoxylated trimethylolpropane tris(meth)acrylate, (3)propoxylated trimethylolpropane tris(meth)acrylate, (6)ethoxylated trimethylolpropane tris(meth)acrylate, (6)propoxylated trimethylolpropane tris(meth)acrylate, etc.

[0088] The high-functional active diluent can be at least one of di-trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.

[0089] In addition, it should be noted that in the above active diluents, “(meth)acrylate” refers to both “acrylate” and “methacrylate”, “(meth)acrylic acid” refers to both “acrylic acid” and “methacrylic acid”, “(meth)acryloyloxy” refers to both “acryloyloxy” and “methacryloyloxy”, and other components involving “(meth)” are similar. The number in “(3)” in the Chinese names of the above bifunctional and trifunctional active diluents represents the number of ethoxy groups. For example, (3)ethoxylated bisphenol A di(meth)acrylate represents bisphenol A di(meth)acrylate modified with 3 ethoxy groups. Another example is that (200) in “polyethylene glycol(200)” refers to the average molecular weight of polyethylene glycol, and the same applies to polyethylene glycol(400) and polyethylene glycol(600).

[0090] In some embodiments, the thermal curing agent includes at least one of blocked isocyanate compounds, amino resins, benzoxazine resins, carbodiimide resins, maleimide compounds, cyclic carbonate compounds, epoxy compounds, polyfunctional oxetane compounds, or cyclic sulfur resins. The thermal curing agent can achieve or promote the thermal cross-linking reaction of other components in the photosensitive resin composition, improving the heat resistance of the cured product and the bonding ability and sealing property with the substrate.

[0091] Among them, the above-mentioned epoxy compound can be selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, glycidylamine epoxy resin, hydantoin epoxy resin, alicyclic epoxy resin, brominated epoxy resin, hydroquinone epoxy resin, biphenyl type crystalline epoxy resin, naphthalene type epoxy resin, thioether type epoxy resin, o-cresol novolak type epoxy resin, biphenol novolak type epoxy resin, trihydroxyphenylmethane type epoxy resin, biphenol type epoxy resin, bisphenol A novolak type epoxy resin, tetramethylol ethane type epoxy resin, heterocyclic epoxy resin, diglycidyl phthalate resin, tetraglycidyl xylene benzoyl ethane resin, dicyclopentadiene skeleton glycidyl methacrylate copolymer epoxy resin, cyclohexyl maleimide and glycidyl methacrylate copolymer epoxy resin, epoxy modified polybutadiene rubber derivative or CTBN-modified epoxy resin, etc. The epoxy equivalent of the thermal curing agent is 100-400 g / eq; for example, any value among 100, 150, 200, 250, 300, 350, 400 or the range value between any two of them; the above-mentioned thermal curing agent selected can realize or promote the thermal cross-linking reaction of other components in the photosensitive resin composition, and improve the heat resistance of the cured product, the bonding ability with the substrate and the sealing property.

[0092] The above-mentioned polyfunctional oxetane compound can be selected from at least one of bis[(3-methyl-3-oxetanylmethoxy)methyl] ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl] ether, 1,4-bis[(3-methyl-3-oxetanyl methoxy)methyl] benzene, 1,4-bis[(3-ethyl-3-oxetanyl methoxy)methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and its oligomers or copolymers, oxetanol, novolak resin, poly(p-hydroxystyrene), Cardo type bisphenol, calixarene and calix[4]resorcinarene, etc.

[0093] The above-mentioned amino resin is the general term for resins obtained by polycondensation of amino-containing compounds such as urea, melamine or benzoguanamine with formaldehyde or alcohols; the amino resin can be selected from at least one of hydroxymethyl melamine compounds, hydroxymethyl benzoguanamine compounds, hydroxymethyl glycoluril compounds and hydroxymethyl urea compounds, etc. Further, the above-mentioned thermal curing agent includes at least one of an epoxy compound, a polyfunctional oxetane compound or an amino resin.

[0094] Further, the present application may select a nitrogen-containing six-membered heterocyclic compound (CN117706870A) as an active diluent and / or as a thermal curing agent. This nitrogen-containing six-membered heterocyclic compound can improve the heat resistance and adhesion of the photosensitive dry film, reduce undercutting, lower side etching, and has excellent electroless nickel immersion gold properties.

[0095] In some embodiments, the photoinitiator includes a free radical polymerization photoinitiator (cleavage type or hydrogen abstraction type) and / or a cationic polymerization photoinitiator; among them, the cleavage type free radical polymerization photoinitiator includes α-hydroxy ketone derivatives, α-amino ketone derivatives, acylphosphine oxides, oxime esters, etc.; the hydrogen abstraction type free radical initiator includes benzophenone and its derivatives, thioxanthone and its derivatives, anthraquinone and its derivatives, and can also be titanocene compounds.

[0096] For example, the α-hydroxy ketone derivatives can be 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxy)phenyl]-3-hydroxy-2-methyl-1-propanone-1-one; commercial products such as Omnirad 184, Omnirad 1173 manufactured by IGM Resins.

[0097] The α-amino ketone derivatives can be 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone, 2-p-methylbenzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, etc.; commercial products such as Omnirad 907, Omnirad 369, Omnirad 379 manufactured by IGM Resins.

[0098] The acylphosphine oxides can be 2,4,6-trimethylbenzoyl ethoxyphenyl phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide, etc., and commercial products such as Omnirad TPO, Omnirad 819, Omnirad TPO-L, etc.

[0099] The oxime ester photoinitiators can be 1,8-bis[9-ethyl-6-nitro-9H-carbazol-3-yl]-, 1,8-bis(O-acetyl oxime), 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), etc., and commercial products such as OXE-01 manufactured by BASF, OXE-02, NCI-831 manufactured by ADEKA CORPORATION, N-1919, etc.

[0100] The thioxanthone-based photoinitiators can be 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone, etc., and commercially available products such as ITX, DETX, etc.

[0101] As the metallocene-based photopolymerization initiator, bis(cyclopentadienyl)-diphenyltitanium, bis(cyclopentadienyl)-titanium dichloride, bis(cyclopentadienyl)-bis(2,3,4,5,6-pentafluorophenyl)titanium, bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl)titanium, etc. can be selected; commercially available products such as Omnirad 784 manufactured by IGM Resins B.V.

[0102] The cationic polymerization photoinitiators include, but are not limited to, any one or a mixture of two or more of aryl diazonium salts, diaryliodonium salts, triarylsulfonium salts, arene iron salts, cumene ferrocene hexafluorophosphate, etc., and commercially available products such as didodecylbenzenesulfonium iodide, long-chain alkoxydiphenyliodonium salts, phenylthiophenyldiphenylsulfonium salts, diphenylsulfonium hexafluoroantimonate, UV16976, UV16992, UV261, etc.

[0103] During the reliability test of this application, in order to avoid or eliminate the problem of aggravated small molecule penetration caused by defect points caused by the aging of the resin composition, an antioxidant is also added. When only a small amount of antioxidant exists in the polymer system, it can delay or inhibit the progress of the polymer oxidation process, thereby preventing the aging of the polymer and prolonging its service life. The role of the antioxidant is to eliminate the newly generated free radicals or promote the decomposition of hydroperoxides and prevent the progress of the chain reaction.

[0104] In some embodiments, the antioxidant includes antioxidant I; wherein, antioxidant I includes aromatic amine compounds and / or hindered phenol compounds, such as aromatic amines, hindered phenols and other compounds and their derivatives. The above antioxidant I, as a primary antioxidant, can capture and eliminate free radicals to prevent oxidation deterioration of resins, etc.; further, antioxidant I is selected from at least one of 2-tert-butylhydroquinone, hydroquinone monomethyl ether, pentaerythritol tetra(3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylate), 2,6-di-tert-butyl-p-cresol, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, p-methoxyphenol and phenothiazine; as commercially available products such as Irganox1010, Irganox1076, Irganox1135, Tinuvin 292, Tinuvin 152, Tinuvin 5100, etc. The antioxidant may further include antioxidant II as a secondary antioxidant, which can decompose hydroperoxides, mainly phosphorus-containing organic compounds and / or sulfur-containing organic compounds; for example: at least one of triphenyl phosphite, pentaerythritol tetra(lauryl thioacrylate) and dilauryl thiodipropionate; as commercially available products such as Mark Ao-412S, AdekastabTPP, etc.

[0105] In the case of containing inorganic filler I and inorganic filler II, an increase in the addition amount of excessive inorganic filler II may cause a decrease in chemical resistance. By adding a suitable antioxidant, the high-temperature and high-humidity aging performance of the dry film can be further improved without changing the addition amount of the flaky filler. The PCT tolerance time can be further increased from 96 h to 120 h, significantly extending the time for the dry film to resist high temperature and boiling water. The spherical inorganic filler I, the flaky inorganic filler II and the antioxidant are used in combination in this application. After the three act synergistically, the chemical resistance and reliability of the photosensitive dry film can be improved simultaneously.

[0106] The above-mentioned reliability test PCT refers to the autoclave steaming test, with a temperature of 121 °C, a humidity of 100%, a pressure of 0.2 MPa, and a time of 96 h; in the PCT test, the solder mask layer will inevitably cause aging degradation of some or all of the polymer chains when exposed to high-temperature water vapor for a long time. Small molecules such as water vapor and acid will strengthen the attack on the solder mask layer from the weak links where aging degradation occurs, which is visually manifested as bubbling or cracking of the solder mask layer. In the destructive tensile test, the solder mask layer will peel off and the adhesion will decrease.

[0107] According to the third aspect of the present application, a method for preparing the above dry film is provided: first, prepare raw materials according to the respective component ratios; then mix an alkali-soluble vinyl resin, an active diluent, a thermal curing agent, a photoinitiator, a filler, and an antioxidant to form a slurry, and then coat the slurry on a substrate and dry it into a film.

[0108] For the convenience of dry film transportation and storage, the above-mentioned substrate is used to support the above-mentioned dry film, and then a protective film is covered on the surface of the dry film; the materials of the above-mentioned substrate and / or the above-mentioned protective film can be selected from PET / PBT / PEN / PP / PE / release paper, etc.

[0109] In the above method, since the dispersion uniformity of the filler has a great influence on the coating appearance and performance of the paint film, when the filler agglomerates, the surface of the paint film will be uneven, orange peel or gloss will be reduced. The agglomeration of the filler will also increase the microscopic porosity of the paint film, weaken the barrier effect on water and other corrosive substances, and cause the reduction of chemical resistance. Therefore, this application designs a two-step method for dispersing the filler, including a pulping process and a coating process; the steps of the pulping process:

[0110] Step S1: Add the filler to the solvent under ultrasonic conditions, and obtain a filler pre-dispersion liquid after ultrasonic dispersion;

[0111] Step S2: Add the filler pre-dispersion liquid to the alkali-soluble vinyl resin under stirring conditions, and obtain a slurry after stirring.

[0112] Specifically, mix the solvent and the dispersant, and place them in a high-power ultrasonic device. Slowly add the required filler (such as filler I and filler II) under ultrasonic conditions. After all are added, continue ultrasonic treatment for 2 h. More specifically, first add the resin to a mechanical high-speed dispersion device and stir for 2 h, control the temperature of the device to be constant at 40 °C. The viscosity of the resin at this temperature is relatively low. Then, slowly add the filler pre-dispersion liquid obtained by ultrasonic dispersion in the first step under medium-speed stirring, and continue medium-speed stirring for 2 h and then high-speed sanding and stirring to finally obtain a delicate slurry.

[0113] Specifically, in step S1, the ultrasonic dispersion time is 1.5 - 2.5 h; in step S2, control the alkali-soluble vinyl resin at a constant temperature of 35 - 45 °C, then add the filler pre-dispersant, and continue medium-speed stirring for 1.5 - 2.5 h (2 h) to obtain the above-mentioned slurry.

[0114] According to the fourth aspect, a cured film is provided. The cured film is obtained by sequentially performing photocuring and thermal curing on a photosensitive dry film; wherein, the photosensitive dry film is the above-mentioned photosensitive dry film or the photosensitive dry film formed after drying the above-mentioned resin composition.

[0115] Specifically, the above-mentioned photocuring requires the Stouffer exposure scale to reach 9 - 11 / 21 steps; the above-mentioned thermal curing conditions include: temperature 150 - 180 °C, time 60 - 90 min.

[0116] According to the fifth aspect, a printed circuit board is provided. The printed circuit board includes a copper plate and a cured film attached to the surface of the copper plate; wherein, the cured film is the above-mentioned cured film.

[0117] The present application will be further described in detail below in conjunction with specific embodiments, which should not be construed as limiting the scope claimed by the present application.

[0118] The raw materials used in the embodiments and comparative examples of the present application are those of the prior art and are all commercially available.

[0119] Example 1

[0120] This Example 1 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 20 μm; filler I is spherical silica with a median particle size D50 of 2.5 μm and a maximum particle size D100 of 4.8 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm.

[0121] The resin composition of the above photosensitive dry film includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, Nippon Kayaku), 10.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 20.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 0.1 g of diphenyl-(2,4,6-trimethylbenzoyl) phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 10.5 g of silica (D50 2.5 μm, D100 4.8 μm, solid, commercially available), 4.5 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), and 0.1 g of antioxidant 1010 (BASF).

[0122] Example 2

[0123] This Example 2 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 20 μm, filler I is spherical silica with a median particle size D50 of 2.5 μm and a maximum particle size D100 of 4.8 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm.

[0124] The resin composition of the photosensitive dry film described above includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, Nippon Kayaku), 30.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 40.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 5.0 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 24.75.0 g of silica (D50 2.5 μm, D100 4.8 μm, solid, commercially available), 20.25 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 3.0 g of antioxidant 1010 (BASF).

[0125] Example 3

[0126] Example 3 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 20 μm, filler I is spherical silica with a median particle size D50 of 4.0 μm and a maximum particle size D100 of 5.0 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm;

[0127] The resin composition of the photosensitive dry film described above includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, Nippon Kayaku), 20.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 20.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 25.5 g of silica (D50 4.0 μm, D100 5.0 μm, solid, commercially available), 4.5 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 1.5 g of antioxidant 1010 (BASF).

[0128] Example 4

[0129] Example 4 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 20 μm, filler I is spherical silica with a median particle size D50 of 4.0 μm and a maximum particle size D100 of 5.0 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm;

[0130] The resin composition of the photosensitive dry film described above comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 20.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 40.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Forever New Materials Co., Ltd.), 16.5 g of silica (D50 4.0 μm, D100 5.0 μm, solid, commercially available), 13.5 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 1.5 g of antioxidant 1010 (BASF).

[0131] Example 5

[0132] Example 5 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 40 μm, filler I is spherical silica with a median particle size D50 of 5.0 μm and a maximum particle size D100 of 7.5 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm;

[0133] The resin composition of the photosensitive dry film described above comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 5.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 5.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 20.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Forever New Materials Co., Ltd.), 8.25 g of silica (D50 5.0 μm, D100 7.5 μm, solid, commercially available), 6.75 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 1.5 g of antioxidant 1010 (BASF).

[0134] Example 6

[0135] Example 6 provides a photosensitive dry film with excellent chemical resistance, the dry film thickness is 40 μm, filler I is spherical silica with a median particle size D50 of 8.0 μm and a maximum particle size D100 of 9.8 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm;

[0136] The resin composition of the photosensitive dry film described above includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 10.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 10.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 10.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 31.5 g of silica (D50 8.0 μm, D100 9.8 μm, solid, commercially available), 13.5 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 0.15 g of antioxidant 1010 (BASF).

[0137] Example 7

[0138] Example 7 provides a photosensitive dry film with excellent chemical resistance. The dry film has a thickness of 40 μm. For filler I, spherical silica with a median particle size D50 of 8.0 μm and a maximum particle size D100 of 9.8 μm is selected; for filler II, flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm is selected.

[0139] The resin composition of the photosensitive dry film described above includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 15.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 21.0 g of silica (D50 8.0 μm, D100 9.8 μm, solid, commercially available), 9.0 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 3.0 g of antioxidant 1010 (BASF).

[0140] Example 8

[0141] The difference between Example 8 and Example 1 is that the thickness of the photosensitive dry film is 10 μm, and for filler I, spherical silica with a median particle size D50 of 2.5 μm and a maximum particle size D100 of 3.5 μm is selected.

[0142] Example 9

[0143] The difference between this Example 9 and Example 8 is that filler I is spherical barium sulfate with a median particle size D50 of 1.5 μm and a maximum particle size D100 of 2 μm.

[0144] Example 10

[0145] The difference between this Example 10 and Example 9 is that filler I is amorphous barium sulfate with a median particle size D50 of 1.5 μm and a maximum particle size D100 of 2 μm.

[0146] Example 11

[0147] The difference between this Example 11 and Example 9 is that filler I is angular barium sulfate with a median particle size D50 of 1.5 μm and a maximum particle size D100 of 2 μm.

[0148] Example 12

[0149] The difference between this Example 12 and Example 7 is that the film thickness is 50 μm.

[0150] Example 13

[0151] The difference between this Example 13 and Example 7 is that the film thickness is 100 μm, and filler I is spherical silica with a median particle size D50 of 12.5 μm and a maximum particle size D100 of 14.5 μm.

[0152] Example 14

[0153] The difference between this Example 14 and Example 1 is that filler I is hollow silica.

[0154] Example 15

[0155] The difference between this Example 15 and Example 1 is that filler I is spherical titanium dioxide.

[0156] Example 16

[0157] The difference between this Example 16 and Example 1 is that filler I is spherical aluminum oxide.

[0158] Example 17

[0159] This Example 17 provides a photosensitive dry film with excellent chemical resistance; the film thickness of the paint film is 20 μm, and filler I is spherical silica with a median particle size D50 of 2.5 μm and a maximum particle size D100 of 4.8 μm.

[0160] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanurate triacrylate (THEICTA, Sartomer), 15.0 g of a biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 30.0 g of silica (D50 2.5 μm, D100 4.8 μm, solid, commercially available), and 1.5 g of antioxidant 1010 (BASF).

[0161] Example 18

[0162] The difference between Example 18 and Example 1 is that filler II is selected as flaky mica powder with a median particle size D50 of 7 μm, a maximum particle size D100 of 10 μm, and a thickness of 0.5 μm.

[0163] Example 19

[0164] The difference between Example 19 and Example 1 is that filler II is selected as flaky mica powder with a median particle size D50 of 1 μm, a maximum particle size D100 of 5 μm, and a thickness of 0.5 μm.

[0165] Example 20

[0166] The difference between Example 20 and Example 1 is that filler II is selected as flaky mica powder with a median particle size D50 of 10 μm, a maximum particle size D100 of 15 μm, and a thickness of 0.5 μm.

[0167] Example 21

[0168] The difference between Example 21 and Example 1 is that filler II is selected as flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 1 μm.

[0169] Example 22

[0170] The difference between Example 22 and Example 1 is that filler II is selected as flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 1.5 μm.

[0171] Example 23

[0172] The difference between Example 23 and Example 1 is that the filler II is flaky talc powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm.

[0173] Example 24

[0174] Example 24 provides a photosensitive dry film with excellent chemical resistance; the film thickness is 20 μm, and the filler I is spherical silica with a median particle size D50 of 2.5 μm and a maximum particle size D100 of 4.8 μm.

[0175] The resin composition includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 15.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation of Japan), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), and 30.0 g of silica (D50 2.5 μm, D100 4.8 μm, solid, commercially available).

[0176] Example 25

[0177] Example 25 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 20 μm, the filler I is spherical silica with a median particle size D50 of 2.5 μm and a maximum particle size D100 of 4.8 μm; the filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm;

[0178] The resin composition includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 15.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation of Japan), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 21.0 g of silica (D50 2.5 μm, D100 4.8 μm, solid, commercially available), and 9.0 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.).

[0179] Example 26

[0180] Example 26 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 40 μm, filler I is spherical silica with a median particle size D50 of 5.0 μm and a maximum particle size D100 of 7.5 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm.

[0181] The resin composition includes: 100.0 g of alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 15.0 g of biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 6.0 g of silica (D50 5.0 μm, D100 7.5 μm, solid, commercially available), 6.0 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 1.5 g of antioxidant 1010 (BASF).

[0182] Example 27

[0183] Example 27 provides a photosensitive dry film with excellent chemical resistance; the dry film thickness is 40 μm, filler I is spherical silica with a median particle size D50 of 5.0 μm and a maximum particle size D100 of 7.5 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm.

[0184] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 15.0 g of a biphenyl crystalline epoxy resin (YX-4000, manufactured by Mitsubishi Chemical Corporation, Japan), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 43.0 g of silica (D50 5.0 μm, D100 7.5 μm, solid, commercially available), 5.0 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), 1.5 g of antioxidant 1010 (BASF).

[0185] Comparative Example 1

[0186] This Comparative Example 1 provides a photosensitive dry film; the dry film has a thickness of 20 μm, and filler I is spherical silica with a median particle size D50 of 5.0 μm and a maximum particle size D100 of 7.5 μm.

[0187] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, Sartomer), 15.0 g of a biphenyl crystalline epoxy resin (YX-4000, manufactured by Mitsubishi Chemical Corporation, Japan), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 30.0 g of silica (D50 5.0 μm, D100 7.5 μm, solid, commercially available).

[0188] Comparative Example 2

[0189] This Comparative Example 2 provides a photosensitive dry film; the dry film has a thickness of 20 μm.

[0190] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, manufactured by Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, manufactured by Sartomer), 15.0 g of a biphenyl crystalline epoxy resin (YX-4000, manufactured by Mitsubishi Chemical Corporation, Japan), 15.0 g of triglycidyl isocyanurate (TGIC, manufactured by Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, manufactured by Tianjin Jiuri New Materials Co., Ltd.), and 13.5 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, manufactured by Chuzhou Anhui Silk New Materials Co., Ltd.).

[0191] Comparative Example 3

[0192] This Comparative Example 3 provides a photosensitive dry film; the dry film thickness is 20 μm.

[0193] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mgKOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, manufactured by Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanuric acid triacrylate (THEICTA, manufactured by Sartomer), 15.0 g of a biphenyl crystalline epoxy resin (YX-4000, manufactured by Mitsubishi Chemical Corporation, Japan), 15.0 g of triglycidyl isocyanurate (TGIC, manufactured by Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, manufactured by Tianjin Jiuri New Materials Co., Ltd.), and 1.5 g of antioxidant 1010 (manufactured by BASF).

[0194] Comparative Example 4

[0195] This Comparative Example 4 provides a photosensitive dry film; the dry film thickness is 20 μm.

[0196] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 12.0 g of tris(2-hydroxyethyl)isocyanurate triacrylate (THEICTA, Sartomer), 15.0 g of a biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 15.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 13.5 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), and 1.5 g of antioxidant 1010 (BASF).

[0197] Comparative Example 5

[0198] This Comparative Example 5 provides a photosensitive dry film; the dry film has a thickness of 20 μm, filler I is spherical silica with a median particle size D50 of 3.6 μm and a maximum particle size D100 of 9.8 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm;

[0199] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 20.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 20.0 g of a biphenyl crystalline epoxy resin (YX-4000, Mitsubishi Chemical Corporation, Japan), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 21.0 g of silica (D50 3.6 μm, D100 9.8 μm, Lianrui New Materials), 9.0 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), and 1.5 g of antioxidant 1010 (BASF).

[0200] Comparative Example 6

[0201] This Comparative Example 6 provides a photosensitive dry film; the dry film has a thickness of 40 μm, filler I is spherical silica with a median particle size D50 of 2.5 μm and a maximum particle size D100 of 4.8 μm; filler II is flaky mica powder with a median particle size D50 of 3.3 μm, a maximum particle size D100 of 8.0 μm, and a thickness of 0.5 μm;

[0202] The resin composition comprises: 100.0 g of an alkali-soluble vinyl resin CCR-4959 (acid value: 75.7 mg KOH / g, solid content 65.3%, manufactured by Nippon Kayaku Co., Ltd.), 20.0 g of dipentaerythritol hexaacrylate (DPHA, Sartomer), 20.0 g of triglycidyl isocyanurate (TGIC, Nissan Chemical Industries, Ltd.), 2.5 g of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Tianjin Jiuri New Materials Co., Ltd.), 21.0 g of silica (D50 2.5 μm, D100 4.8 μm, solid, commercially available), 9.0 g of mica powder (BT-30, D50 3.3 μm, D100 8.0 μm, thickness 0.5 μm, Chuzhou Anhui Silk New Materials Co., Ltd.), and 1.5 g of antioxidant 1010 (BASF).

[0203] The formulations of the resin compositions of Examples 1 to 27 and Comparative Examples 1 to 6 are shown in Table 1; slurries are prepared according to the following preparation method:

[0204] Step S1: Mix the solvent and the dispersant, and place them in a high-power ultrasonic device. Slowly add the required filler 1 and filler 2 under ultrasonic conditions. After all are added, continue ultrasonic treatment for 2 h.

[0205] Step S2: First, add the resin to a mechanical high-speed dispersion device and stir for 2 h, controlling the temperature of the device to be constant at 40 °C. The viscosity of the resin at this temperature is relatively low. Then, slowly add the filler pre-dispersion liquid obtained by ultrasonic dispersion in the first step under medium-speed stirring, and continue medium-speed stirring for 2 h and then high-speed sand grinding and stirring to finally obtain a delicate slurry.

[0206] Coat the slurry on a copper plate, and perform photocuring and thermal curing in sequence to obtain a solder resist insulating cured film; among them, the Stouffer exposure scale reaches 9 to 11 / 21 steps, the thermal curing temperature is 150 to 180 °C, and the time is 60 to 90 min.

[0207] The chemical resistance of the photosensitive dry films or cured films prepared in Examples 1 to 27 and Comparative Examples 1 to 6 is tested by the following methods. Among them, methods (1), (2), (3), and (5) test the properties of the cured films, and method (4) tests the properties of the uncured photosensitive dry films. The test results are shown in Table 2.

[0208] (1) Acid resistance: First, immerse the cured film in a 25 °C 10 wt% H2SO4 or 25 °C 10 vol% HCl aqueous solution for 30 min. After the immersion, wipe the water stains on the surface of the dry film with a lint-free cloth, scratch the film surface with a cross cutter, and then pull it up vertically at 90° with a 3M 600 tape to see if there is peeling. The adhesion shall not be lower than 5B.

[0209] (2) Immersion Gold and Nickel Property: Subject the cured film to immersion gold and nickel surface treatment [degreasing → water washing → micro-etching → water washing → pickling → pre-dipping → nickel activation → water washing → post-dipping → water washing → nickel immersion → water washing → gold immersion → drying]. Then, use a cross cutter to score the surface of the dry film after the immersion gold and nickel surface treatment, and then vertically lift it at 90° with 3M 600 tape to check for peeling. The adhesion shall not be lower than 5B.

[0210] (3) Nickel Palladium Gold Property: Subject the cured film to immersion gold and nickel surface treatment [degreasing → water washing → micro-etching → water washing → pickling → pre-dipping → nickel activation → water washing → post-dipping → water washing → nickel immersion → water washing → palladium immersion → water washing → gold immersion → water washing → drying].

[0211] (4) Side Etching: Use a film with line width / line pitch L / d: 50μm / 50μm respectively to make a circuit pattern on the photosensitive dry film; section the circuit pattern and observe the cross-section with a metallurgical microscope to obtain the side etching size and record the data.

[0212] (5) PCT: Pressure cooker cooking, temperature 121°C, humidity 100%, pressure 0.2MPa, cooking times are 48h, 96h, and 120h respectively. After the test, observe and record the appearance, such as whether there are problems of cracking and blistering. If there are no above problems, conduct a cross-cut adhesion test. The evaluation criteria for passing the PCT test are: there are no problems such as cracking and blistering on the appearance of the solder mask layer and the adhesion is not lower than 5B under the corresponding test time.

[0213] ◎: No cracking or blistering on the appearance; ○: Blistering but no cracking on the appearance; ×: Cracking on the appearance or both cracking and blistering on the appearance.

[0214] Table 1 Formulations of Photosensitive Dry Films and Photosensitive Resin Compositions for Examples 1 - 27 and Comparative Examples 1 - 6

[0215]

[0216]

[0217] Table 2 Chemical Resistance Test Results of Examples 1 - 27 and Comparative Examples 1 - 6

[0218]

[0219]

[0220] As can be seen from the test results in Table 1, the acid resistance adhesion, immersion gold and nickel adhesion, and nickel palladium gold adhesion of the photosensitive dry films in Examples 1 - 27 of this application can mostly reach the 4B - 5B level, and the reliability PCT reaches up to 120h at the longest; the chemical resistance of the photosensitive dry films in Comparative Examples 1 - 6 is 1 - 3B, and most of the PCT is 48h and below; obviously, the comprehensive chemical resistance of the photosensitive dry films in Examples 1 - 27 is better than that of the photosensitive dry films in Comparative Examples 1 - 6.

[0221] By comparing the acid resistance adhesion, nickel immersion gold resistance adhesion, nickel palladium gold adhesion and side etching performance of the photosensitive dry films of Examples 1 to 27 and Comparative Examples 1 to 6, it can be seen that the ratio of the dry film thickness of 20μm / 40μm to the median particle size D50 of the filler in Examples 1 to 27 is within the range of (4 to 8):1, and the ratio of the dry film thickness of 20μm / 40μm to the maximum particle size D100 of the inorganic filler is above 2.8, which can significantly improve the chemical resistance of the solder mask photosensitive dry film.

[0222] In the present application, obstacles are provided in the penetration and diffusion path of acidic small molecules and / or the penetration and diffusion path is extended, so as to extend the time for acidic small molecule substances to reach the interface between the dry film and copper. In the same time, it is shown that the etching amount of the copper oxide at the interface between the acidic small molecules and the dry film is low or almost no etching, thereby improving the chemical resistance of the dry film. At the same time, by adding more antioxidants to the dry film resin composition, the chemical resistance of the dry film can be improved. After further adding Filler II, the combined action of Filler I, Filler II and the antioxidant significantly improves the comprehensive chemical resistance and reliability of the photosensitive dry film.

[0223] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A photosensitive dry film, characterized in that: The photosensitive dry film includes a base film and an inorganic filler distributed in the base film; wherein the ratio of the thickness of the photosensitive dry film to the median particle size D50 of the inorganic filler is (4-8):1, and the ratio of the thickness of the photosensitive dry film to the maximum particle size D100 of the inorganic filler is greater than 2.

8.

2. The photosensitive dry film according to claim 1, characterized in that: The ratio of the thickness of the photosensitive dry film to the median particle size D50 of the inorganic filler is (5-8):1; And / or, the ratio of the thickness of the photosensitive dry film to the maximum particle size D100 of the inorganic filler is greater than or equal to 4; preferably 4-7.

3. The photosensitive dry film according to claim 1 or 2, characterized in that: The thickness of the photosensitive dry film is less than or equal to 100 μm; preferably 10 to 50 μm; more preferably 15 to 40 μm; and even more preferably 20 to 40 μm; And / or, the inorganic filler has a median particle size D50 of 2.5 to 8.0 μm, and a maximum particle size D100 of less than or equal to 10 μm.

4. The photosensitive dry film according to any one of claims 1 to 3, characterized in that: The inorganic filler comprises inorganic filler I; Wherein, the inorganic filler I is selected from at least one of titanium dioxide, barium sulfate, silicon dioxide and aluminum hydroxide; Preferably, the inorganic filler I has a median particle size D50 of 2.5 to 8.0 μm, and a maximum particle size D100 of less than or equal to 10 μm; Preferably, the inorganic filler further comprises an inorganic filler II; wherein the inorganic filler II is flaky mica powder and / or flaky talc powder; Preferably, the inorganic filler II has a median particle size D50 of 1 to 10 μm, and a maximum particle size D100 of less than or equal to 15 μm; Preferably, the inorganic filler II has a median particle size D50 of 3 to 7 μm, and a maximum particle size D100 of less than or equal to 10 μm; Preferably, the inorganic filler II has a median particle size D50 of 3 to 7 μm and a maximum particle size D100 of 5 to 10 μm; Preferably, the thickness of the inorganic filler II is less than or equal to 1.5 μm; preferably 0.5 to 1.0 μm; Preferably, the inorganic filler II is distributed in the base film substantially parallel to the surface of the base film; and / or the raw material of the base film includes an alkali-soluble vinyl resin; Preferably, the alkali-soluble vinyl resin is selected from at least one of carboxylic acid-modified bisphenol A epoxy vinyl resin, carboxylic acid-modified bisphenol F epoxy vinyl resin, carboxylic acid-modified bisphenol S epoxy vinyl resin and carboxylic acid-modified phenolic epoxy vinyl resin.

5. A resin composition for preparing the photosensitive dry film according to any one of claims 1 to 4, characterized in that: The raw materials of the resin composition include the following components in parts by weight: 100 parts of alkali-soluble vinyl resin, 10-30 parts of active diluent, 20-40 parts of thermal curing agent, 0.1-5 parts of photoinitiator, 15-45 parts of inorganic filler, and 0.1-3 parts of antioxidant.

6. The resin composition according to claim 5, characterized in that The inorganic filler includes an inorganic filler I; wherein the inorganic filler I is selected from at least one of titanium dioxide, barium sulfate, silicon dioxide and aluminum hydroxide; Preferably, the morphology of the inorganic filler I includes at least one of amorphous, angular and spherical; Preferably, the inorganic filler I is a solid filler and / or a hollow filler; more preferably, it is a solid filler; Preferably, the inorganic filler I has a median particle size D50 of 2.5 to 8.0 μm, and a maximum particle size D100 of less than or equal to 10 μm; Preferably, the inorganic filler further comprises an inorganic filler II; wherein the inorganic filler II is flaky mica powder and / or flaky talc powder; Preferably, the inorganic filler II has a median particle size D50 of 1 to 10 μm, and a maximum particle size D100 of less than or equal to 15 μm; Preferably, the median particle size D50 of the inorganic filler II is 3 to 7 μm; and the maximum particle size D100 is less than or equal to 10 μm; Preferably, the inorganic filler II has a median particle size D50 of 3 to 7 μm and a maximum particle size D100 of 5 to 10 μm; Preferably, the thickness of the inorganic filler II is less than or equal to 1.5 μm; preferably 0.5 to 1.0 μm; Preferably, the weight ratio of the inorganic filler I to the inorganic filler II is (11-17):(3-9); Preferably, the inorganic filler I and / or the inorganic filler II is surface-modified by a modifying compound; wherein the modifying compound is an epoxy compound or an acrylic compound.

7. The resin composition according to claim 5 or 6, characterized in that The alkali-soluble vinyl resin is selected from at least one of carboxylic acid-modified bisphenol A epoxy vinyl resin, carboxylic acid-modified bisphenol F epoxy vinyl resin, carboxylic acid-modified bisphenol S epoxy vinyl resin and carboxylic acid-modified phenolic epoxy vinyl resin; Preferably, the acid value of the alkali-soluble vinyl resin is 45 to 120 mg KOH / g, more preferably 80 to 100 mg KOH / g; And / or, the active diluent is selected from at least one of a monofunctional active diluent, a bifunctional active diluent, a trifunctional active diluent, and a high-functional active diluent; Preferably, the monofunctional reactive diluent is selected from aromatic (meth)acrylates, alkoxy dodecyl (meth)acrylates, alicyclic (meth)acrylates, 2(2-ethoxyethoxy)ethyl acrylate, octadecyl (meth)acrylate, tetrahydrofuran (meth)acrylate, dodecyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, alicyclic (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, caprolactone (meth)acrylate, (4)ethoxylated nonylphenol (meth)acrylate, ) acrylate, isobornyl (meth) acrylate, trimethylolpropane formal (meth) acrylate, methoxy polyethylene glycol mono(meth) acrylate, methoxy polyethylene glycol (500) mono(meth) acrylate, alkoxylated tetrahydrofuran (meth) acrylate, alkoxylated nonylphenol (meth) acrylate, dimethylaminoethyl (meth) acrylate, glycidol (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 4-hydroxybutyl vinyl ether, glycerol carbonate propenyl ether and dodecyl vinyl ether; Preferably, the bifunctional active diluent is selected from cyclohexanedimethanol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, alkoxylated neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol (200) di(meth)acrylate, triethylene glycol di(meth)vinyl ether, tetraethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,4-cyclohexyl dimethacrylate At least one of alcohol di(meth)alkenyl ether, ethylene glycol di(meth)acrylate, pentylene glycol methyl di(meth)acrylate, polyethylene glycol (400) di(meth)acrylate, polyethylene glycol (600) di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, dipropylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate and propoxylated neopentyl glycol di(meth)acrylate; Preferably, the trifunctional reactive diluent is selected from at least one of tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, and the like; Preferably, the high-functionality active diluent is selected from at least one of di-trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; and / or, the thermal curing agent comprises at least one of a blocked isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a maleimide compound, a cyclic carbonate compound, an epoxy compound, a multifunctional oxetane compound and an episulfide resin; Preferably, the epoxy compound is selected from bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, glycidylamine epoxy resin, hydantoin epoxy resin, alicyclic epoxy resin, brominated epoxy resin, hydroquinone epoxy resin, biphenyl crystalline epoxy resin, naphthalene epoxy resin, thioether epoxy resin, o-cresol novolac epoxy resin, biphenol novolac epoxy resin, trishydroxyphenylmethane epoxy resin. At least one of epoxy resin, biphenol type epoxy resin, bisphenol A novolac type epoxy resin, tetramethylolethane type epoxy resin, heterocyclic epoxy resin, diglycidyl phthalate resin, tetraglycidyl ditoluoyl ethane resin, dicyclopentadiene skeleton glycidyl methacrylate copolymer epoxy resin, cyclohexyl maleimide and glycidyl methacrylate copolymer epoxy resin, epoxy-modified polybutadiene rubber derivative and CTBN-modified epoxy resin; Preferably, the epoxy equivalent of the epoxy compound is 100 to 400 g / eq; Preferably, the multifunctional oxetane compound is selected from at least one of bis[(3-methyl-3-oxetanylmethoxy)methyl]ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl]ether, 1,4-bis[(3-methyl-3-oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, (3-methyl-3-oxetanyl)methyl acrylate, (3-ethyl-3-oxetanyl)methacrylate, (3-methyl-3-oxetanyl)methyl methacrylate, (3-ethyl-3-oxetanyl)methyl methacrylate and oligomers or copolymers thereof, oxetane alcohol, novolac resin, poly(p-hydroxystyrene), Cardo-type bisphenol, calixarene and calixisophthalene; Preferably, the amino resin is selected from at least one of methylol melamine compounds, methylol benzoguanamine compounds, methylol glycoluril compounds and methylol urea compounds.

8. The resin composition according to any one of claims 5 to 7, characterized in that The photoinitiator includes a cleavage-type free radical polymerization photoinitiator, a hydrogen abstraction-type free radical polymerization photoinitiator and a cationic polymerization photoinitiator; Preferably, the cleavage-type free radical polymerization photoinitiator is selected from at least one of α-hydroxyketone derivatives, α-aminoketone derivatives, acylphosphorus oxides and oxime esters; Preferably, the α-hydroxyketone derivatives are selected from at least one of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1-[4-(2-hydroxy)-phenyl]-3-hydroxy-2-methyl-1-propanone-1-one; Preferably, the α-amino ketone derivative is selected from at least one of 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 2-phenylbenzyl-2-dimethylamino-1-(4-morpholinylbenzylphenyl)butanone and 2-p-methylbenzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone; Preferably, the acylphosphine oxide is selected from at least one of 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; Preferably, the oxime ester is 1,8-bis[9-ethyl-6-nitro-9H-carbazole-3-yl]-, 1,8-bis(O-acetyl oxime) and / or 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime); Preferably, the hydrogen abstraction free radical initiator is selected from at least one of benzophenone and its derivatives, thioxanthone and its derivatives, anthraquinone and its derivatives, and titanocene; Preferably, the thioxanthone is selected from at least one of 2,4-diethylthioxanthone, isopropylthioxanthone and 1-chloro-4-propoxythioxanthone; Preferably, the titanocene is selected from at least one of bis(cyclopentadienyl)-diphenyl titanium, bis(cyclopentadienyl)-titanium dichloride, bis(cyclopentadienyl)-bis(2,3,4,5,6-pentafluorophenyl) titanium and bis(cyclopentadienyl)-bis(2,6,-difluoro-3-(pyrrol-1-yl)phenyl) titanium; Preferably, the cationic polymerization photoinitiator is selected from at least one of aryl diazonium salts, diaryl iodonium salts, triaryl sulfonium salts, aryl ferrocenium salts and cumene ferrocenium hexafluorophosphate; Preferably, the cationic polymerization photoinitiator is at least one selected from dodecylbenzene iodonium salt, long-chain alkoxy diphenyl iodonium salt, phenylthiophenyl diphenyl sulfonium salt, diphenyl sulfonium hexafluoroantimonate, UV16976, UV16992 and UV261; And / or, the antioxidant includes antioxidant I; wherein the antioxidant I includes aromatic amine compounds and / or hindered phenol compounds; Preferably, the antioxidant I is selected from at least one of 2-tert-butylhydroquinone, hydroquinone monomethyl ether, pentaerythritol tetra(3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylate, 2,6-di-tert-butyl-p-cresol, 1,3,5-trimethyl-2,4,6-tri(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, p-methoxyphenol and phenothiazine; Preferably, the antioxidant further comprises an antioxidant II; wherein the antioxidant II is a phosphorus-containing organic compound and / or a sulfur-containing organic compound; Preferably, the antioxidant II is selected from at least one of triphenyl phosphite, pentaerythritol tetra(lauryl thioacrylate) and dilauryl thiodipropionate.

9. A cured film, characterized in that: The cured film is obtained by sequentially subjecting a photosensitive dry film to light curing and heat curing; wherein the photosensitive dry film is the photosensitive dry film according to any one of claims 1 to 4 or the photosensitive dry film formed by drying the resin composition according to any one of claims 5 to 8.

10. A printed circuit board, characterized in that: The printed circuit board comprises a copper plate and a cured film attached to a surface of the copper plate; wherein the cured film is the cured film according to claim 9.

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