Photosensitive resin composition, photosensitive dry film and application thereof

Abstract

The invention provides a photosensitive resin composition, a photosensitive dry film and application thereof. The photosensitive resin composition comprises alkali-soluble resin, a photopolymerization monomer, a photoinitiator and a modified anthracene sensitizer. By introducing the modified anthracene sensitizer into a resin system, on one hand, the photosensitivity of the obtained photosensitive resin composition can be greatly improved; on the other hand, compared with the related technology, the obtained photosensitive resin composition has the advantages that the performance in the aspects of resolution, adhesive force performance, flexibility grade, initiator migration, development precipitation and the like is improved, so that the photosensitive resin composition is suitable for manufacturing high-order PCBs (Printed Circuit Boards) such as support plates and similar support plates, and can meet the performance requirements of special use scenes such as long copper columns and mSAP thick copper plating; the production yield can be remarkably improved, the production efficiency of manufacturing parts such as ITO in the fields of PCB manufacturing, lead frame manufacturing, semiconductor packaging and flat panel displays is remarkably improved, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of printed circuit boards, and in particular to a photosensitive resin composition, a photosensitive dry film and applications thereof. Background Art

[0002] Photosensitive resin compositions are widely used as etching or electroplating resist materials in the manufacturing process of printed circuit boards (PCBs), lead frames (LFs) and semiconductor packaging (IC) substrates. The photosensitive resin composition is usually coated on the surface of a PET support film, and after drying, a protective layer such as a polyethylene film (PE) protective layer is closely attached to the surface, which is also called a photosensitive dry film, dry film resist, etc.

[0003] In the production process of circuit boards, when the developer is used to dissolve or disperse the unexposed part of the photosensitive resin layer after exposure, the dry film resist components are usually not completely dissolved in the developer. When the development process is repeated, the insoluble components with poor dispersibility in the developer will increase, resulting in the appearance of agglutinates (scum). When the agglutinate reattaches to the substrate and electroplating and etching operations are performed, it may cause adverse reactions such as short circuits. The agglutinate has a particularly significant impact on the production yield of circuit boards with fine wiring patterns, and is extremely detrimental to client stability.

[0004] The main reason for the above-mentioned agglomerates is the photopolymerization initiator powder system. The known mSAP substrate dry film resist uses a system of hexaarylbiimidazole compounds (photopolymerization initiators) and 9,10-dibutoxyanthracene (DBA) (photosensitizer). However, 9,10-dibutoxyanthracene has poor solubility in aqueous solution and has a general photosensitivity effect. In order to improve the photosensitivity effect, the amount of photopolymerization initiator and photosensitizer added is usually increased. However, excessive addition will lead to poor water solubility, which is very likely to cause the undesirable phenomenon of agglomerates in the developer.

[0005] Chinese application CN117693714A discloses a photosensitive composition, which also discloses that when a hexaarylbisimidazole compound and 9,10-dibutoxyanthracene are used simultaneously in a photosensitive resist, 9,10-dibutoxyanthracene will migrate into the protective film, and when forming a resist pattern, the desired pattern shape may not be formed, and this is particularly evident when the protective film is a polyethylene film. In addition, studies have shown that the photosensitivity effect of the hexaarylbisimidazole compound combined with 9,10-dibutoxyanthracene needs to be further improved. Summary of the invention

[0006] The first purpose of the present application is to provide a photosensitive resin composition to obtain higher photosensitivity, so as to better meet practical application requirements.

[0007] The photosensitive resin composition provided in the present application comprises an alkali-soluble resin, a photopolymerizable monomer, a photoinitiator and a sensitizer; The sensitizer is selected from one or more of the compounds represented by the structural formulas AN-1 to AN-7:

[0008] Wherein, Z is selected from any one of a nitrogen atom, an oxygen atom or a sulfur atom; when Z is selected from a nitrogen atom, the nitrogen atom carries a hydrogen atom or a methyl group; X represents any one of a hydrogen atom, a halogen, a nitro group, an alkyl group with a carbon chain length of C1 to C8, an alkoxy group with a carbon chain length of C1 to C4, a phenyl group, an alkanoyl group with a carbon chain length of C1 to C4, or an ester group with a carbon chain length of C1 to C4 on the anthracene ring; Y represents any one of a hydrogen atom, a halogen, an alkanoyl group with a carbon chain length of C1 to C4, an ester group with a carbon chain length of C1 to C4, a nitro group, an alkyl group with a carbon chain length of C1 to C8, an alkoxy group with a carbon chain length of C1 to C4, a phenyl group, an amide group, a trifluoromethyl group or a cyano group on the benzene ring; the benzene ring to which Y is connected can be selected from other aromatic rings; Ra and R' each independently represent an alkyl group with a carbon chain length of C1 to C4; Rx is selected from any one of a hydrogen atom or a methyl group; “C n H 2n O" and "C m H 2m O" represents a structural unit of a diol or a polyether diol, wherein m and n each independently represent an integer of 1 to 6, and a1 and a2 each independently represent an integer of 0 to 20.

[0009] The "other aromatic rings" mentioned in the present invention may refer to other aromatic rings except the benzene ring, especially condensed aromatic rings, such as naphthalene ring, anthracene ring, etc., the same below.

[0010] In the sensitizer provided by the present invention, in the compounds represented by structural formulas AN-1 to AN-7, the number of substitution sites of the X group is usually 0 to 4, the number of substitution sites of the Y group is usually 0 to 5, and when X or Y has multiple substitution sites, X or Y at different substitution sites may be the same or different.

[0011] Preferably, X represents any one of hydrogen atom, halogen, alkyl group with carbon chain length of C1-C4, alkoxy group with carbon chain length of C1-C4 (especially hydrogen atom) on the anthracene ring, which can be independently selected from; Y represents any one of hydrogen atom, halogen, and alkyl group with carbon chain length of C1 to C4 (especially hydrogen atom) on the benzene ring, which can be independently selected; Ra and R' independently represent an alkyl group with a carbon chain length of C1 to C4 (especially a methyl group or an ethyl group); Rx represents hydrogen or methyl, "C n H 2n O" and "C m H 2m O" represents a diol or polyether diol structural unit, wherein m and n each independently represent any integer of 1 to 4 (especially 1 to 2), and a1 and a2 each independently represent any integer of 0 to 4 (especially 0 to 2).

[0012] More preferably, the sensitizer is selected from one or more of the compounds represented by structural formulae D-1 to D-19:

[0013] Among them, R1~R 18 Each is independently selected from any one of a hydrogen atom or a methyl group; X1~X 18 Each independently represents any one of a hydrogen atom, a halogen, a nitro group, an alkyl group with a carbon chain length of C1 to C8, an alkoxy group with a carbon chain length of C1 to C4, a phenyl group, an alkanoyl group with a carbon chain length of C1 to C4, or an ester group with a carbon chain length of C1 to C4 on the anthracene ring; Y1-Y7 each independently represents a benzene ring selected from any one of a hydrogen atom, a halogen, an alkanoyl group with a carbon chain length of C1 to C4, an ester group with a carbon chain length of C1 to C4, a nitro group, an alkyl group with a carbon chain length of C1 to C8, an alkoxy group with a carbon chain length of C1 to C4, a phenyl group, an amide group, a trifluoromethyl group or a cyano group; the benzene ring to which Y1-Y3 is connected may be other aromatic rings; R, Ra, Ra1, Ra2, R', R'1, and R'2 each independently represent an alkyl group with a carbon chain length of C1 to C4.

[0014] “C n H 2n O" and "C m H 2m O" represents a structural unit of a diol or a polyether diol, wherein m and n each independently represent an integer of 1 to 6, and a1 and a2 each independently represent an integer of 0 to 20.

[0015] Preferably, X1~X 18Each independently represents any one of a hydrogen atom and an alkyl group with a carbon chain length of C1 to C4 (especially a hydrogen atom) on the anthracene ring; Y1~Y7 represent any one of hydrogen atom, halogen, and alkyl group with carbon chain length of C1~C4 (especially hydrogen atom) on the benzene ring, which can be independently selected; R, Ra, Ra1, Ra2, R', R'1, R'2 each independently represent an alkyl group with a carbon chain length of C1 to C4 (especially methyl or ethyl); “C n H 2n O" and "C m H 2m O" represents a diol or polyether diol structural unit, wherein m and n each independently represent any integer of 1 to 4 (especially 1 to 2), and a1 and a2 each independently represent any integer of 0 to 4 (especially 0 to 2).

[0016] The photosensitive resin composition provided in this application introduces D1-D 19 The anthracene sensitizers with their own hydrogen donors are shown, on the one hand, D1-D 19 The heteroatoms nitrogen, oxygen or sulfur in the structure all have active hydrogen atoms at the α position, and the heteroatoms nitrogen, oxygen or sulfur contained therein will form p-π conjugation with the benzene ring or anthracene ring, so that the ultraviolet absorption will be red-shifted, increasing the photosensitivity of the photosensitive resin composition to the i-ray (355nm) or h-ray (405nm) exposure light source; on the other hand, the α-carbon of the heteroatom is connected to the benzene ring, carbonyl, allyl and other groups with electron-withdrawing π bonds, so that the hydrogen on the α-carbon of the heteroatom is strongly acidic, resulting in the high activity of the hydrogen on the α-carbon, which is easy to leave as a proton; therefore, The initiator free radical (LŸ) can more easily capture the H proton from the more active α-position carbon to generate an amine alkyl free radical or an oxyalkyl or sulfanyl free radical with higher reaction activity, thereby initiating the polymerization reaction of the photopolymerizable monomer, thereby greatly improving the light absorption range and the final light curing speed of the photosensitive resist resin composition. It can also extremely effectively improve the solubility of anthracene sensitizers in the resist glue system and the developer aqueous solution system, increase the uniformity of the glue, improve the developer precipitation problem, and improve the production yield and production efficiency of resist manufacturers and downstream manufacturers.

[0017] In addition, this type of modified sensitizer (photosensitizer) retains the anthracene structure in the molecule, which gives it excellent deep curing ability. The anti-etching pattern after exposure can achieve a very high aspect ratio, thereby achieving high resolution. It can be used in the production of high-end PCBs such as high-precision IC substrates, and can also take into account high-resolution and high-thickness dry film resists.

[0018] A more ideal sensitizer is selected from one or more of the compounds shown in the following structural formula:

[0019] From the viewpoint of improving the sensitivity, resolution and adhesion in a more balanced manner, the mass percentage of the sensitizer in the photosensitive resin composition (which may be referred to as "dry film resist", the same below) is 0.05% to 1.5%. When the amount is less than 0.05%, the photosensitivity of the obtained dry film resist is poor. When the amount is higher than 1.5%, the surface layer of the dry film resist cures too quickly, affecting the curing depth, and there is a risk of reducing the adhesion of the dry film resist on the copper surface.

[0020] Preferably, the mass percentage of the sensitizer in the photosensitive resin composition is 0.1% to 0.5%, and particularly suitable amounts are 0.15%, 0.2%, 0.3%, etc.

[0021] The photosensitive resin composition described in the present application is to improve the photosensitivity, resolution, and adhesion of the dry film resist resin composition and reduce adverse phenomena such as initiators. The initiator system is mainly a hexaarylbisimidazole derivative in combination with a sensitizer. Preferably, the hexaarylbisimidazole derivative has a structural formula as shown in formula (I): (I)

[0022] In formula (I), the substituents A on the benzene rings are each independently selected from a hydrogen atom, a methoxy group, and a halogen atom, and the number and type of the substituents on each benzene ring may be the same or different.

[0023] Preferably, the photoinitiator is selected from one or more of 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0024] More preferably, in addition to the above photoinitiators, a small amount of other types of photoinitiators can also be used in combination, and the other types of photoinitiators can also be selected from one or more of pyrazoline compounds, acridine compounds, quinone compounds, aromatic ketone compounds, benzoin ether compounds, oxime ester compounds, coumarin compounds, and triarylamine compounds; As the pyrazoline compound, one or more of 1-(4-(benzoxazol-2-yl)phenyl)-3-(4-tert-butylphenylphenyl)-5-(4-tert-butylphenyl)pyrazoline, 1-phenyl-3-(4-tert-butylphenylphenylphenyl)-5-(4-tert-butylphenyl)pyrazoline, 1-phenyl-3-(4-biphenylyl)-5-(4-tert-octylphenyl)pyrazoline, and 1-phenyl-3-(4-biphenylyl)-5-(4-tert-butylphenyl)pyrazoline can be selected; As the acridine compound, for example, 9-phenylacridine, 9-chloroethylacridine, 9-ethylacridine, 9-methoxyacridine, 9-(4-methylphenyl)acridine, 9-(4-methoxyphenyl)acridine, 9-(4-hydroxyphenyl)acridine, 9-ethoxyacridine, 9-(4-methylphenyl)acridine, 9-(4-ethylphenyl)acridine, 9-(4-n-propylphenyl)acridine, 9-(4-n-butylphenyl)acridine, 9-(4-tert-butylphenyl)acridine, 9 -(4-ethoxyphenyl)acridine, 9-(4-acetylphenyl)acridine, 9-(4-dimethylaminophenyl)acridine, 9-(4-chlorophenyl)acridine, 9-(4-bromophenyl)acridine, 9-(3-methylphenyl)acridine, 9-(3-tert-butylphenyl)acridine, 9-(3-acetylphenyl)acridine, 9-(3-dimethylaminophenyl)acridine, 9-(3-diethylaminophenyl)acridine, and one or more of 9-(3-chlorophenyl)acridine; As the quinone compound, one or more of 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone and 3-chloro-2-methylanthraquinone can be selected; As aromatic ketone compounds, for example, benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], and 4,4'-bis(diethylamino)benzophenone can be selected. As benzoin ethers, for example, one or more of benzoin, benzoin ethyl ether, benzoin phenyl ether, methylbenzoin, and ethylbenzoin can be cited; As the oxime ester compound, one or more of 1-phenyl-1,2-propanedione-2-O-benzoin oxime and 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime may be selected.

[0025] The photoinitiation mechanism of the photosensitive resist containing the hexaarylbisimidazole derivative / anthracene sensitizer / hydrogen donor initiator system is as follows: the anthracene sensitizer produces an excited state from the ground state under light irradiation and transfers energy to the hexaarylbisimidazole (BCIM) to form an excited state complex, and then the molecule undergoes homolysis to produce stable and inactive free radicals (LŸ) that can hardly initiate photopolymerization. The free radicals (LŸ) capture the hydrogen donor to produce primary free radicals and effectively initiate photopolymerization.

[0026] In addition, based on the optimization of the system formula, the present invention can significantly solve the migration problem of the sensitizer to the non-polar PE protective film and bring about significant improvements in solubility and developability.

[0027] The photosensitive resin composition provided in the present application, wherein the alkali-soluble resin is prepared by copolymerization of (meth) acrylic acid and one or more (meth) acrylic acid ester free radicals, and preferably has a structure as shown in the general formula (A1): (A1)

[0028] Wherein, Ra1, Ra2, Ra3, and Ra4 are each independently represented by a hydrogen atom or a methyl group; Rb1 and Rb2 each independently represent a hydrogen atom, an alkyl group with a carbon chain length of C1 to C5, an alkoxy group with a carbon chain length of C1 to C5, a hydroxyl group or a halogen atom, and x and y each independently represent any integer from 0 to 5; Rc is selected from C5~C 14 Substituted or unsubstituted monocyclic carbocyclic alkyl, C5~C 14 Substituted or unsubstituted bicyclic carbocyclic alkyl, C5~C 14 Substituted or unsubstituted polycyclic carbocyclic alkyl, C5~C 14 Substituted or unsubstituted monocyclic heterocycloalkyl, C5~C 14 Substituted or unsubstituted bicyclic heterocycloalkyl, C5~C 14 Any one of substituted or unsubstituted polycyclic heterocycloalkyl, wherein the bicyclic carbocycloalkyl and the polycyclic carbocycloalkyl have a cyclic structure or a bridged ring structure; a, b, c, and d represent the weight of each copolymer component in the alkali-soluble resin, respectively, wherein a is 20 to 35 wt %, b is 0 to 60 wt %, c is 0 to 60 wt %, and d is 0 to 40 wt %.

[0029] Preferably, in the above structural formula A1: Ra1, Ra2, Ra3, and Ra4 are independently represented by a hydrogen atom or a methyl group; Rb1 and Rb2 both represent hydrogen atoms; Rc is selected from C5~C14 Substituted or unsubstituted adamantane, cyclohexane, cyclopentane, trimethylcyclohexyl, 4-tert-butylcyclohexyl, tetrahydrofurfuryl, tricyclodecane, norbornyl, isobornyl, dicyclopentyl, 2-tetrahydrofuranyl, etc.; a, b, c, and d represent the proportion of each copolymer component in the alkali-soluble resin, wherein a is 23-30 wt%, b is 15-60 wt%, c is 0-40 wt%, and d is 10-30 wt%.

[0030] Furthermore, the alkali-soluble copolymer resin of the present invention may optionally contain alicyclic alkane (meth) acrylate structural units, and the alicyclic alkane (meth) acrylate structural units may be selected from: 1-adamantane (methyl) methacrylate, 2-adamantane (methyl) methacrylate, (meth) acrylic acid tricyclo [5.2.1.02,6] dec-8-yl ester, 2-methyl-2-adamantane alcohol acrylate, 2-ethyl-2-adamantane alcohol acrylate, 2-carboxy-4-norbornyl lactone-5-methacrylate, 2-isopropyl-2-adamantane alcohol (meth) acrylate, isobornyl acrylate, acryloyl morpholine, 1-adamantyl methacrylate, 3-hydroxy-1-adamantane (methyl) propionate, cyclohexane dicarboxylic acid imide acrylate, 2-cyclohexyl methacrylate, 5-oxotetrahydrofuran-3-yl methacrylate, 5-carboxy-2-tetrahydrofuranmethanol-methacrylate, 1-ethylcyclopentyl methacrylate, 1-isopropyl-1-cyclohexanol methacrylate, 2-cyclohexyl-2-propanol methacrylate, 2-carbonyl-tetrahydrofuran-3-hydroxy-methacrylate, methylcyclopentyl acrylate, 1-ethylcyclopentyl acrylate, 2-oxotetrahydrofuran-3-yl acrylate, cyclohexyl (meth) acrylate, 1-methyl-1-cyclohexyl methacrylate, 1-methylcyclopentyl methacrylate, 1-ethylcyclohexyl methacrylate, 1-methyl-1-ethyl-1-adamantane methacrylate, 2-tetrahydrofuranyl methacrylate, 2-methacrylate-4-hydropyran, dicyclopentyl methacrylate, and the like.

[0031] The alkali-soluble copolymer resin of the present invention may optionally contain benzyl or phenoxyethyl (meth)acrylate structural units, and the alicyclic (meth)acrylate structural units may be selected from: benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, o-phenylphenoxyethyl acrylate, and the like.

[0032] Furthermore, the acid value of the alkali-soluble resin is 130-275 mg KOH / g, the weight average molecular weight is 25,000-60,000, and the molecular weight distribution is 1.3-2.5; preferably, the polymerization conversion rate is ≥97%.

[0033] The alkali-soluble copolymer resin has an acid value of less than 130 mg KOH / g, which tends to deteriorate the alkali solubility and prolong the development and stripping time. When it exceeds 275 mg KOH / g, the resolution tends to deteriorate. The narrow molecular weight distribution is conducive to improving the resolution of the photosensitive resist. When the molecular weight distribution is greater than 2.5, the resolution will deteriorate.

[0034] Furthermore, the alkali-soluble copolymer resin described above may be a copolymer resin as shown in the general structural formula (A1), and the copolymer resin as shown in the general structural formula (A1) does not contain a styrene structure; or a small amount of an alkali-soluble copolymer resin containing a styrene structure may be compounded on the basis of the copolymer resin as shown in the general structural formula (A1). In order to ensure that the dry film resist has excellent flexibility, the styrene content in the alkali-soluble copolymer resin of the resist is preferably in the range of 0 to 25wt%, preferably 0 to 20%, more preferably 10% to 20%, for example 10%, 15%, 20%, etc.

[0035] Preferably, the mass percentage of the alkali-soluble copolymer resin in the photosensitive resin composition is 45% to 65%, preferably 50% to 60%, and particularly suitable amounts include 53%, 54%, 55%, 56%, etc.

[0036] The alkali-soluble copolymer resin shown in the general formula (A1) provided by the present invention has excellent flexibility and mechanical properties in structure. The photosensitive resist with this type of alkali-soluble copolymer resin as the main material can simultaneously have excellent adhesion performance and good flexibility. When used by the client, undesirable phenomena such as broken wires, gaps, plating penetration, and short circuits will be significantly reduced, and the yield will be significantly improved.

[0037] The photosensitive resin composition provided by the present application, wherein the photopolymerizable monomer contains at least one EO or PO modified (meth)acrylate represented by the following general formula (B1), (B2), (B3), (B4).

[0038] (B1)

[0039] In the formula, R1 is selected from any one of a hydrogen atom and a methyl group, m1 and m2 each independently represent any integer from 1 to 20, n1 and n2 each independently represent any integer from 0 to 20, m1+m2 is any integer from 2 to 20, n1+n2 is any integer from 0 to 20, and the arrangement of EO and PO repeating units can be random or block.

[0040] Preferably, R1 represents hydrogen or methyl, m1 and m2 each independently represent an integer of 1 to 4, n1 and n2 each independently represent an integer of 0 to 4, m1+m2 is an integer of 2 to 8, and n1+n2 is an integer of 0 to 4.

[0041] (B2)

[0042] In the formula, R1 is selected from any one of a hydrogen atom and a methyl group, and a1, b1, and c1 each independently represent any integer of 3 to 10.

[0043] Preferably, R1 represents hydrogen or methyl, and a1, b1, c1 are integers of 3-8.

[0044] (B3)

[0045] In the formula, R1 is selected from any one of a hydrogen atom and a methyl group, a2 is any integer from 3 to 20, b2 is any integer from 0 to 20, c2 is any integer from 3 to 20, and the arrangement of EO and PO repeating units can be random or block.

[0046] Preferably, R1 represents hydrogen or methyl, a2 is an integer of 3 to 8, b2 is an integer of 0 to 8, and c2 is an integer of 3 to 8.

[0047] (B4)

[0048] In the formula, R1 is selected from any one of a hydrogen atom and a methyl group, a3 is any integer from 4 to 10, and L is any integer from 5 to 15.

[0049] Preferably, R1 represents hydrogen or methyl, and a3 is an integer of 4 to 8.

[0050] Preferably, in addition to the above-mentioned photopolymerizable monomers, the photopolymerizable monomers further include some other commonly used monofunctional, difunctional or polyfunctional (meth)acrylate-based ethylenically unsaturated double-bond monomers.

[0051] Further preferably, the photopolymerizable monomer comprises one or more of lauryl (meth)acrylate, octadecyl (meth)acrylate, nonylphenol acrylate, isobornyl ester, tetrahydrofuran methyl acrylate, bisphenol A di(meth)acrylate, polyethylene glycol (propylene glycol) di(meth)acrylate, ethoxylated (propoxylated) neopentyl glycol diacrylate, trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) pentaerythritol triacrylate, ethoxylated (propoxylated) pentaerythritol tetraacrylate, ethoxylated (propoxylated) dipentaerythritol pentaacrylate, and ethoxylated (propoxylated) dipentaerythritol hexaacrylate.

[0052] In some preferred embodiments provided by the present invention, the photopolymerizable monomer is selected from one or more of (4) ethoxylated bisphenol A diacrylate, (10) ethoxylated (4) propoxylated bisphenol A diacrylate, (15) ethoxylated trimethylolpropane trimethacrylate, (6) ethoxylated polypropylene glycol (700) dimethacrylate or (8) ethoxylated nonylphenol methacrylate.

[0053] The photosensitive resin composition provided in the present application, the total weight of the photopolymerizable monomer is preferably 33 to 50 parts by weight (accounting for about 30% to 50% of the total amount of the photosensitive resin composition). If the weight is less than 33 parts, the photosensitive resin composition is prone to low sensitivity and low resolution problems; if the weight is more than 50 parts, the photosensitive layer is prone to glue overflow.

[0054] Preferably, the mass percentage of the photopolymerizable monomer in the photosensitive resin composition is 33% to 50%, preferably 35 to 46%, and particularly suitable amounts include 40%, 42%, 43%, 44%, etc.

[0055] Preferably, in order to facilitate production and improve the comprehensive performance of the resin product, the present application should also include corresponding additive (E) components, including free radical inhibitors, colorants, plasticizers, light and heat stabilizers, adhesion promoters, leveling agents, defoaming agents, and one or more thereof in any proportion.

[0056] Preferably, from the viewpoint of inhibiting polymerization in the unexposed portion during formation of the resist pattern, improving resolution, adhesion, and enhancing the shape of the dry film resist pattern, the free radical inhibitor in the additive component of the photosensitive resin composition can be p-methoxyphenol, 4-ethyl-6-tert-butylphenol, tert-butylcatechol, 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl, nitrosophenylhydroxylamine aluminum salt, 2-methylcatechol, 3-methylcatechol, 4-methylcatechol, catechol, 2-ethylcatechol, 3-ethylcatechol, 4-ethylcatechol, 2-propylcatechol, 3-propylcatechol, 4-propylcatechol, 2-n-butylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 2-tert-butyl tert-butylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, 3,5-di-tert-butylcatechol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 2-ethylresorcinol, 4-ethylresorcinol, 2-propylresorcinol, 4-propylresorcinol, 2-n-butylresorcinol, 4-n-butylresorcinol, 2-tert-butyl One or more of resorcinol, 4-tert-butylresorcinol, 1,4-hydroquinone, methylhydroquinone, ethylhydroquinone, propylhydroquinone, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-4-methylphenol, pyrogallol, 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl, 2,2-methylenebis(4-methyl-6-tert-butylphenol), etc.

[0057] From the perspective of balancing key properties such as sensitivity, resolution, adhesion, and resist shape, the amount of the above-mentioned free radical inhibitor added is 0.001 to 0.05% by mass of the photosensitive resin composition (or dry film resist). When the amount added is less than 0.001%, the resolution of the resulting resist is insufficient. When the amount added is more than 0.05%, the photosensitivity of the resulting dry film resist is poor.

[0058] The photosensitive resin composition provided in the present application has low migration, high photosensitivity, and high resolution, and does not require the use of a hydrogen donor. It is suitable for the production of high-end PCBs such as high-precision IC substrates and thick copper, and can also be used as a high-thickness dry film resist for special scenarios.

[0059] As a preferred embodiment of the present application, the photosensitive resin composition comprises, by weight: (A) 45-65 parts of alkali-soluble resin

[0060] (B) 33-50 parts of photopolymerizable monomer

[0061] (C) Photoinitiator 1.5-4.0 parts

[0062] (D) 0.05 to 1.5 parts of sensitizer

[0063] (E) Additives 0.5 to 5 parts.

[0064] Preferably, the photosensitive resin composition comprises, by weight: (A) 50-60 parts of alkali-soluble resin

[0065] (B) 35-46 parts of photopolymerizable monomer

[0066] (C) Photoinitiator 2.5-4.0 parts

[0067] (D) 0.1-0.5 parts of sensitizer

[0068] (E) Additives 0.5 to 3.5 parts.

[0069] More preferably, in the above formulation, the total weight of the components (A) alkali-soluble resin, (B) photopolymerizable monomer, (C) photoinitiator, (D) sensitizer and (E) additive is 100 parts.

[0070] Among them, for (B) photopolymerizable monomer, if its weight is less than 33 parts, the photosensitive resin composition is prone to low sensitivity and low resolution problems; if its weight is more than 50 parts, the photosensitive layer obtained by curing is prone to overflow problems.

[0071] The present application also provides a photosensitive dry film, which includes a support layer and a photosensitive resist layer, and the photosensitive resist layer is prepared from the above-mentioned photosensitive resin composition.

[0072] The present application also provides the use of the above-mentioned photosensitive resin composition or the above-mentioned photosensitive dry film in the manufacturing process of a printed circuit board (PCB), a lead frame (LF) or a flexible circuit board (FPC).

[0073] The present application optimizes the formula and combines a modified anthracene sensitizer with a hexaarylbisimidazole photoinitiator, thereby significantly improving the photosensitivity of the photosensitive resin composition, while solving the problem of the migration of the sensitizer to the polymer film layer in the related art; in the photosensitive resin composition system disclosed in the present application, the resolution, adhesion performance, flexibility level, initiator migration, development precipitation, etc. are all improved; further, the photosensitive resin composition is more suitable for the production of high-end PCBs such as carrier boards and carrier-like boards, and can take into account the performance requirements of special usage scenarios such as long copper pillars and mSAP thick copper plating, which can significantly improve the production yield, significantly improve the production efficiency of PCB manufacturing, lead frame manufacturing, semiconductor packaging, ITO and other components in the field of flat panel displays, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0075] Figure 1 This is a side view of a dry film with a line width of 25 um taken with a scanning electron microscope (SEM) at a magnification of 1000 times. DETAILED DESCRIPTION

[0076] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0077] Combine the following Figure 1 , the preferred embodiments and comparative examples of the present application are described. However, the following embodiments are only preferred implementation examples of the present application and are not intended to limit the present application.

[0078]

Synthetic anthracene sensitizer

[0079] (1) Synthesis of sensitizer D'-1

[0080] In a 250 mL three-necked flask, add 9,10-anthracene diamine (10.4 g, 0.05 mol), benzaldehyde (12.7 g, 0.12 mol), methanol (150 mL), stir at room temperature for 15 min, add 3 drops of glacial acetic acid, stir at room temperature for 4 h, slowly add sodium cyanoborohydride (6.2 g, 0.1 mol) under ice-water bath cooling, react in ice-water bath for 30 min after addition, and stir at room temperature for 2 h. TLC spot plate monitoring raw material 9,10-anthracene diamine is completely consumed. After the reaction is completed, the reaction mixture is poured into water (200 g), and the obtained mixture is extracted with ethyl acetate, 200 mL each time, extracted twice, the obtained organic phase is combined, extracted twice with saturated brine (100 mL*2), dried over anhydrous sodium sulfate, filtered, and the filtrate is distilled under reduced pressure on a rotary evaporator to obtain a crude product. The obtained solid crude product was dispersed in a mixed solution of petroleum ether: ethyl acetate = 5:1 (100 mL), stirred at room temperature for 30 min, filtered, collected the solid, and dried using a rotary evaporator. After removing a small amount of solvent contained in the solid, sensitizer D'-1 (13.75 g, purity 98%, yield 87%) was obtained.

[0081] (2) Synthesis of sensitizer D'-2

[0082] In a 500 mL three-necked flask, add 9,10-anthracene diamine (31.2 g, 0.15 mol), paraformaldehyde (10.8 g, 0.36 mol), methanol (250 mL), stir at room temperature for 15 min, add 5 drops of glacial acetic acid, stir at room temperature for 4 h, slowly add sodium cyanoborohydride (18.6 g, 0.3 mol) under ice-water bath cooling, after addition, react in ice-water bath for 30 min, and stir at room temperature for 2 h. TLC spot plate monitoring raw material 9,10-anthracene diamine is completely consumed. After the reaction is completed, the reaction mixture is poured into water (500 g), and the obtained mixture is extracted with ethyl acetate, 500 mL each time, extracted twice, the obtained organic phase is combined, extracted twice with saturated brine (200 mL*2), dried over anhydrous sodium sulfate, filtered, and the filtrate is distilled under reduced pressure on a rotary evaporator to obtain a crude product. The crude product was purified by column chromatography to obtain the intermediate compound D'-2-1 (28.2 g, purity 95%).

[0083] In a 250 mL three-necked flask, add the intermediate compound D'-2-1 (4.7 g, 0.021 mol), 4-acetylformaldehyde (7.4 g, 0.05 mol), methanol (100 mL), stir at room temperature for 15 min, add 3 drops of glacial acetic acid, stir at room temperature for 4 h, slowly add sodium cyanoborohydride (2.6 g, 0.05 mol) under ice-water cooling, react in an ice-water bath for 30 min after addition, and stir at room temperature for 2 h. TLC spot plate monitoring raw material D'-2-1 is completely consumed. After the reaction is completed, pour the reaction mixture into water (200 g), extract the aqueous solution with ethyl acetate, 200 mL each time, extract twice, combine the organic phases, extract twice with saturated brine (100 mL*2), dry over anhydrous sodium sulfate, filter, and use a rotary evaporator to distill the filtrate under reduced pressure to obtain a crude product. The obtained crude solid product was dispersed in a mixed solution of petroleum ether: ethyl acetate = 5:1 (100 mL), stirred at room temperature for 30 min, filtered, collected the solid, and dried using a rotary evaporator. After removing a small amount of solvent contained in the solid, sensitizer D'-2 (6.1 g, purity 97%) was obtained.

[0084] (3) Synthesis of sensitizer D'-3

[0085] Sensitizer D'-3 was synthesized by the same method as compound D'-2, except that 4-acetylbenzaldehyde was replaced by 4-propionylbenzaldehyde.

[0086] (4) Synthesis of sensitizer D'-4

[0087] Sensitizer D'-4 was synthesized by the same method as compound D'-1, except that benzaldehyde was replaced by methyl p-formylbenzoate.

[0088] (5) Synthesis of sensitizer D'-5

[0089] In a 250 mL three-necked flask, add 9,10-anthracene diamine (12.5 g, 0.06 mol), tetrahydrofuran (160 mL), potassium carbonate (33.2 g, 0.24 mol), stir at room temperature for 15 min, cool in an ice-water bath, slowly add 2-bromoacetophenone (28.6 g, 0.14 mol) under nitrogen protection, after addition, react in an ice-water bath for 30 min, and reflux for 8 h. TLC spot plate monitoring of the complete consumption of the raw material 9,10-anthracene diamine. After the reaction is completed, pour the reaction mixture into water (200 g), extract the aqueous solution with ethyl acetate, 200 mL each time, extract twice, combine the organic phases, extract twice with saturated brine (100 mL*2), dry over anhydrous sodium sulfate, filter, and use a rotary evaporator to distill the filtrate under reduced pressure to obtain a crude product. The obtained solid crude product was dispersed in a mixed solution of petroleum ether: ethyl acetate = 5:1 (100 mL), stirred at room temperature for 30 min, filtered, collected the solid, and dried using a rotary evaporator. After removing a small amount of solvent contained in the solid, sensitizer D'-5 (14.9 g, purity 96%, yield 76%) was obtained.

[0090] (6) Synthesis of sensitizer D'-6

[0091] Sensitizer D'-6 was synthesized by the same method as compound D'-1, except that benzaldehyde was replaced by anthracene-9,10-dicarbaldehyde, and 9,10-anthracenediamine was replaced by N-methylaniline.

[0092] (7) Synthesis of sensitizer D'-7

[0093] In a 250 mL three-necked flask, add the intermediate compound D'-2-1 (13.4 g, 0.06 mol), tetrahydrofuran (160 mL), potassium carbonate (33.2 g, 0.24 mol), stir at room temperature for 15 min, cool in an ice-water bath, slowly add 2-bromoacetophenone (28.6 g, 0.14 mol) under nitrogen protection, after addition, react in an ice-water bath for 30 min, and reflux for 8 h. TLC spot plate monitoring raw material compound D'-2-1 is completely consumed. After the reaction is completed, the reaction mixture is poured into water (200 g), and the obtained mixture is extracted with ethyl acetate, 200 mL each time, extracted twice, the obtained organic phases are combined, extracted twice with saturated brine (100 mL*2), dried over anhydrous sodium sulfate, filtered, and the filtrate is distilled under reduced pressure on a rotary evaporator to obtain a crude product. The obtained solid crude product was dispersed in a mixed solution of petroleum ether: ethyl acetate = 5:1 (100 mL), stirred at room temperature for 30 min, filtered, collected the solid, and dried using a rotary evaporator. After removing a small amount of solvent contained in the solid, sensitizer D'-7 (5.7 g, purity 96%) was obtained.

[0094] (8) Synthesis of sensitizer D'-8

[0095] Sensitizer D'-8 was synthesized by the same method as compound D'-7, except that 2-bromoacetophenone was replaced by bromobutyl ketone.

[0096] (9) Synthesis of sensitizer D'-9

[0097] Sensitizer D'-9 was synthesized by the same method as compound D'-7, except that 2-bromoacetophenone was replaced by allyl bromide.

[0098] (10) Synthesis of sensitizer D'-10

[0099] In a 250 mL three-necked flask, add 9,10-anthraquinone (4.2 g, 0.02 mol), N,N-dimethylformamide (50 mL), cesium carbonate (16.3 g, 0.05 mol), stir at room temperature for 15 min, cool in an ice-water bath, slowly add benzyl bromide (7.2 g, 0.042 mol) under nitrogen protection, react at room temperature for 30 min after addition, and reflux for 8 h. TLC spot plate monitoring raw material compound 9,10-anthraquinone is completely consumed. After the reaction is completed, the reaction solution is cooled to room temperature, the reaction mixture is poured into water (200 g), and the obtained mixture is extracted with ethyl acetate, 200 mL each time, extracted twice, the obtained organic phase is combined, extracted twice with saturated brine (100 mL*3), dried over anhydrous sodium sulfate, filtered, and the filtrate is distilled under reduced pressure on a rotary evaporator to obtain a crude product. The obtained solid crude product was purified by column chromatography to obtain sensitizer D'-10 (3.4 g, purity 96%).

[0100] (11) Synthesis of sensitizer D'-11

[0101] Sensitizer D'-11 was synthesized by the same method as compound D'-10, except that benzyl bromide was replaced by 2-bromoacetophenone.

[0102] (12) Synthesis of sensitizer D'-15

[0103] In a 250 mL three-necked flask, add 9,10-dibromoanthracene (10.1 g, 0.03 mol), N,N-dimethylformamide (80 mL), benzyl mercaptan (9.3 g, 0.075 mol), sodium methoxide (4.1 g, 0.075 mol), and stir at 100 °C for 4 h under nitrogen protection. TLC spot plate monitoring shows that the raw material compound 9,10-dibromoanthracene is completely consumed. After the reaction is completed, the reaction solution is cooled to room temperature, the reaction mixture is poured into water (200 g), the reaction mixture is precipitated in water three times, and filtered to obtain a crude product. The obtained crude product is dispersed in a mixed solution of petroleum ether: ethyl acetate = 5:1 (100 mL), stirred at room temperature for 30 min, filtered, the solid is collected, and dried using a rotary evaporator. After removing a small amount of solvent wrapped in the solid, the sensitizer D'-15 (8.9 g, purity 97%) is obtained.

[0104] The synthesis methods of other anthracene sensitizers (photosensitizers) with self-contained hydrogen donors as described above or with similar structures can refer to the synthesis methods of D'1-D'11 and D'15, and the specific operation steps will not be described in detail.

[0105] (13) Synthesis of sensitizer D'-19

[0106] 1) In a 500 mL three-necked flask, add 9,10-anthracene diamine (20.8 g, 0.1 mol), p-hydroxybenzaldehyde (29.3 g, 0.24 mol), methanol (200 mL), stir at room temperature for 15 min, add 5 drops of glacial acetic acid, stir at room temperature for 4 h, slowly add sodium cyanoborohydride (12.4 g, 0.2 mol) under ice-water cooling, react in ice-water bath for 30 min after addition, and stir at room temperature for 2 h. TLC spot plate monitoring raw material 9,10-anthracene diamine is completely consumed. After the reaction is completed, pour the reaction mixture into water (300 g), extract the aqueous solution with ethyl acetate, 300 mL each time, extract twice, combine the organic phases, extract twice with saturated brine (150 mL*2), dry over anhydrous sodium sulfate, filter, and use a rotary evaporator to distill the filtrate under reduced pressure to obtain a crude product. The obtained solid crude product was dispersed in a mixed solution of petroleum ether: ethyl acetate = 5:1 (200 mL), stirred at room temperature for 30 min, filtered, collected the solid, and dried on a rotary evaporator. After removing a small amount of solvent contained in the solid, the intermediate compound 1 (34.2 g, purity 95%) was obtained.

[0107] 2) In a 500 mL three-necked flask, add intermediate compound 1 (22.6 g, 0.05 mol), paraformaldehyde (3.6 g, 0.12 mol), methanol (250 mL), stir at room temperature for 15 min, add 5 drops of glacial acetic acid, stir at room temperature for 4 h, slowly add sodium cyanoborohydride (18.6 g, 0.3 mol) under ice-water bath cooling, react in ice-water bath for 30 min after addition, and stir at room temperature for 2 h. TLC spot plate monitoring of raw material intermediate compound 1 is completely consumed. After the reaction is completed, the reaction mixture is poured into water (300 g), and the obtained mixture is extracted with ethyl acetate, 500 mL each time, extracted twice, the obtained organic phases are combined, extracted twice with saturated brine (200 mL*2), dried over anhydrous sodium sulfate, filtered, and the filtrate is distilled under reduced pressure on a rotary evaporator to obtain a crude product. The crude product is purified by column chromatography to obtain intermediate compound 2 (18.6 g, purity 94%).

[0108] 3) In a 500 mL three-necked flask, add intermediate compound 2 (22.6 g, 0.05 mol), triethylamine (11.1 g, 0.11 mol), and dichloromethane (200 mL). Under nitrogen protection, stir in an ice-water bath for 15 min, then slowly drop methylsulfonyl chloride (12.5 g, 0.11 mol). After the addition is complete, react in an ice-water bath for 30 min, and then react at room temperature for 2 h. TLC spot plate monitoring shows that the raw material compound 2 is completely consumed. After the reaction is completed, pour the reaction mixture into water (300 g), extract the aqueous solution with dichloromethane, 250 mL each time, extract twice, combine the organic phases, extract twice with saturated brine (200 mL*2), dry over anhydrous sodium sulfate, filter, and use a rotary evaporator to distill the filtrate under reduced pressure to obtain a crude product. The obtained crude solid product was dispersed in a mixed solution of petroleum ether: ethyl acetate = 1:1 (200 mL), stirred at room temperature for 30 min, filtered, collected the solid, and dried on a rotary evaporator to obtain intermediate compound 3 (20.3 g, purity 95%).

[0109] 4) In a 500 mL three-necked flask, add intermediate compound 3 (19.1 g, 0.03 mol), ethylene glycol (6.2 g, 0.1 mol), tetrahydrofuran (200 mL), stir at room temperature to dissolve, add potassium carbonate (9.7 g, 0.07 mol), and reflux for 16 h under nitrogen protection. TLC spot plate monitoring shows that the raw material compound 3 is completely consumed. After the reaction is completed, cool to room temperature, pour the reaction mixture into water (200 g), extract the aqueous solution with ethyl acetate, 250 mL each time, extract twice, combine the obtained organic phases, extract twice with saturated brine (200 mL*2), dry with anhydrous sodium sulfate, filter, and distill the filtrate under reduced pressure on a rotary evaporator to obtain a crude product. The crude product was purified by column chromatography to obtain intermediate compound 4 (16.6 g, purity 93%).

[0110] 5) In a 250 mL three-necked flask, add intermediate compound 4 (8.5 g, 0.015 mol), dichloromethane (200 mL), and triethylamine (3.33 g, 0.033 mol). Under nitrogen protection, stir in an ice-water bath for 15 min, then slowly drop acryloyl chloride (2.7 g, 0.03 mol). After the addition is complete, react in an ice-water bath for 2 h, and then react at room temperature for 2 h. TLC spot plate monitoring shows that the raw material compound 4 is completely consumed. After the reaction is completed, pour the reaction mixture into water (100 g), extract the aqueous solution with dichloromethane, 250 mL each time, extract twice, combine the organic phases, extract twice with saturated brine (200 mL*2), dry over anhydrous sodium sulfate, filter, and use a rotary evaporator to distill the filtrate under reduced pressure to obtain a crude product. The obtained solid crude product was dispersed in a mixed solution of petroleum ether: ethyl acetate = 3:1 (100 mL), stirred at room temperature for 30 min, filtered and collected the solid, and the collected solid was redispersed in a mixed solution of petroleum ether: ethyl acetate = 3:1 (100 mL), stirred at room temperature for 30 min, filtered and dried using a rotary evaporator to obtain sensitizer D'-19 (7.7 g, purity 96%).

[0111]

[0112] The synthesis methods of other anthracene sensitizers (photosensitizers) as shown in D'-19 or with similar structures are basically the same. According to actual conditions, the polyformaldehyde in step 2) can be replaced by acetaldehyde; the ethylene glycol in step 4) can be replaced by other diols or other polyether diols; the acryloyl chloride in step 5) can be replaced by methacryloyl chloride. The specific operation steps will not be repeated in detail.

[0113]

Synthetic alkali-soluble copolymer resin

[0114] The method is prepared by free radical solution polymerization, comprising the following steps: The monomers corresponding to the corresponding segments in the compound structure shown in the general formula (A1) are directly purchased. The monomers corresponding to the corresponding segments a, b, c, and d in the compound structure shown in the general formula (A1) are mixed evenly according to the weight ratio (a total of 100 g) for use, mixed with 1.0 g AIBN photoinitiator, 90 g butanone, and 15 g ethanol, stirred and dissolved, and a mixed solution of about 35% by mass is added to a three-necked flask with nitrogen protection and a condensation reflux device through a peristaltic pump, and the oil bath is heated to 80°C, and the remaining mixed solution is added dropwise after stirring for 1 hour, and the addition is completed within 3 hours; after continuing to keep the temperature for 4 hours, the temperature is raised to 90°C, and 5 g butanone solution containing 0.2 g initiator is added twice, with an interval of 1 hour between the two times. After the addition is completed, the temperature is kept and stirred for 2 hours, and the reaction is terminated to obtain an alkali-soluble resin. The weight average molecular weight, molecular weight distribution and solid content of the obtained alkali-soluble copolymer resin are measured by GPC.

[0115] A series of alkali-soluble resins A-1 to A-9 were synthesized according to the formulations in Table 1 below.

[0116] Table 1

[0117]

Preparation of photosensitive resin composition

[0118] In addition to the above-mentioned alkali-soluble resin, photopolymerizable monomer, photoinitiator and sensitizer, the photosensitive resin composition of the present application may further include additives, which are composed of one or more of free radical inhibitors, dyes, photocolorizers, photothermal stabilizers, plasticizers, antioxidants, deodorants, adhesion promoters, leveling agents, and defoaming agents mixed in any proportion.

[0119] The preferred embodiments and comparative examples of the present invention are described below. However, the following embodiments are only preferred embodiments of the present invention, and the present invention is not limited to the following embodiments.

[0120] [Example 1-35, Comparative Example 1-7]

[0121] According to the formula of Table 2, Table 3 and Table 4 below, the components are mixed in proportion, and 50 parts by weight of solvent are added. Among them, the solvent suitable for preparing the coating glue solution can be acetone, butanone, methanol, ethanol, isopropanol, toluene, etc., which can be adjusted according to the actual system requirements. Acetone, butanone and ethanol are preferably used as solvents, and then fully stirred until completely dissolved to form a resin composition solution with a solid content of 40%. Let it stand for 30 minutes, fully degas, and use a coating machine to evenly coat it on the surface of a PET support film with a thickness of 16um, and bake it in a 90℃ oven for 10 minutes to form a dry film resist layer with a thickness of 25um, which is used for the photosensitive resin composition system made of IC carrier board, or to form a dry film resist layer with a thickness of 90-120um, which is a high-resolution, high-thickness dry film resist used in special scenes, and it appears blue-green under a yellow light. Subsequently, a polyethylene film protective layer with a thickness of 20um is attached to its surface to obtain a photosensitive dry film with a 3-layer structure.

[0122] Among them, the specific selection and source of each component are as follows: Alkali-soluble resin A: The chemical structure composition is shown in Table 1 A1-A9, and the conversion rate is all >97%.

[0123] Photopolymerizable monomer B: B-1: (4) Ethoxylated bisphenol A diacrylate (Meiyuan Special Chemicals)

[0124] B-2: (10) Ethoxy (4) Propoxy Bisphenol A Diacrylate (Meiyuan Specialty Chemicals)

[0125] B-3: (15) Ethoxylated trimethylolpropane trimethacrylate (Meiyuan Special Chemicals)

[0126] B-4: (6) Ethoxylated polypropylene glycol (700) dimethacrylate (Meiyuan Special Chemicals)

[0127] B-5: (8) Ethoxylated nonylphenol methacrylate (Meiyuan Special Chemicals)

[0128] Photoinitiator C: C-1: 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole BCIM (Changzhou Qiangli Electronic Materials)

[0129] Sensitizer D: The chemical structural formulas of D'-1 to D'-11, D'-15 and D'-19 are shown in the examples of sensitizer synthesis; DBA: 9,10-dibutoxyanthracene; Additive E: E-1: 4-tert-butylcatechol

[0130] E-2: Brilliant green pigment (Shanghai Bailingwei Chemical Technology Co., Ltd.)

[0131] E-3: Leuco crystal violet (Shanghai Bailingwei Chemical Technology Co., Ltd.)

[0132] E-4: p-Toluenesulfonamide (Shanghai TCI Chemical)

[0133] Table 2

[0134] Table 3

[0135] Table 4

[0136] The following describes the sample preparation method (including film lamination, exposure, development, and copper electroplating), the sample evaluation method, and the evaluation results of the examples and comparative examples.

[0137] (1) Sample preparation method

[0138]

Film

[0139] The copper clad laminate was polished by a grinder, washed with water, and dried to obtain a bright and fresh copper surface. The laminating machine roller temperature was set to 110°C, the conveying speed was 1.0 m / min, and the heat lamination was performed under standard pressure.

[0140]

exposure

[0141] After film pasting, the sample was left to stand for more than 15 minutes. The resolution and adhesion performance were exposed using a Japanese Adtec exposure machine, model: IP-6, a laser direct imaging (LDI) exposure machine with a wavelength of 405nm. A stouffer 41-step exposure ruler was used for photosensitivity testing, and the number of exposure grids was controlled at 13 to 17 grids.

[0142]

development

[0143] After exposure, the sample was left to stand for more than 15 minutes, the developing temperature was 30°C, the pressure was 1.2 Kg / cm2, the developer was a 1%wt sodium carbonate aqueous solution, the developing time was 1.5 to 2.0 times the minimum developing time, and the sample was washed and dried after development. The minimum developing time was the minimum time required for the unexposed part of the resist layer to be completely dissolved.

[0144]

Etching

[0145] The developed copper plate was subjected to an etching process, the etching solution was cupric chloride, the etching speed was 1.0 m / min, the etching temperature was 48°C, the spray pressure was 1.5 bar, the specific gravity was 1.3 g / mL, the acidity was 2 mol / L, the copper ion was 140 g / L, and the etching machine model was Dongguan Universe GL181946.

[0146]

Removal of film

[0147] The stripping solution is NaOH, with a concentration of 3.0wt%, a temperature of 50°C, and a pressure of 1.2Kg / cm 2 The film stripping time is 1.5 to 2.0 times of the minimum film stripping time. After film stripping, wash and dry.

[0148] (2) Evaluation method

[0149]

Evaluation of photosensitivity

[0150] After lamination, the sample was left to stand for more than 15 minutes, and then exposed using an Adtec IP-6 405 nm LDI exposure machine. The sensitivity was tested using a stouffer 41-step exposure ruler. After exposure, it was sprayed with a 1% wt sodium carbonate aqueous solution at 30°C, and the development time was 2.0 times the minimum development time to remove the unexposed part. After this operation, a cured film formed by the cured product of the photosensitive resin composition was formed on the copper surface of the substrate. The exposure amount (mJ / cm2) when the number of remaining segments of the step exposure table obtained as a cured film of a dry film resist with a film thickness of 25 um becomes 15 2 ), the sensitivity of the photosensitive resin composition was evaluated. The smaller the value, the better the sensitivity.

[0151] Judgment basis: ○:25~35 mJ / cm 2

[0152] △: 40~55 mJ / cm 2

[0153] ×:>55 mJ / cm 2 .

[0154] [Evaluation of resolution]

[0155] Exposure is performed using a mask having a wiring pattern with a width of 1:1 between the exposed part and the unexposed part. After development for twice the minimum development time, the minimum mask width at which a cured resist line is normally formed is taken as the resolution value. Observation is performed using a metallographic microscope or a scanning electron microscope (SEM). The smaller the number read, the better the resolution.

[0156]

Evaluation of adhesion

[0157] The photosensitive dry film resist is laminated on the copper plate by hot pressing, and exposed using a mask with a wiring pattern of exposed and unexposed parts with a width of n:400. The corresponding sensitivity is 15 grids. After developing with twice the minimum development time, it is observed with a magnifying glass and the minimum mask width that forms a complete cured resist line is used as the adhesion value. The smaller the number read, the better the adhesion.

[0158]

Evaluation of flexibility

[0159] The dry film resist was laminated and attached to the FPC substrate as a test piece for evaluating the bendability. After lamination, the sample was left to stand for more than 15 minutes, and was exposed using an Adtec IP-6 405 nm LDI exposure machine. The sensitivity test was performed using a stouffer 41-step exposure ruler. The dry film resist with a film thickness of 25um was exposed using an energy level of 15, and the dry film resist with a film thickness of 90um was exposed using an energy level of 20. After developing for a development time twice the minimum development time, a substrate for evaluating the bendability of the dry film resist laminated on the FPC substrate was obtained. The flexibility was evaluated using a mandrel tester. The substrate for evaluating the flexibility was cut into strips with a width of 2 cm and a length of 10 cm. After rubbing it against a cylindrical rod at 180° for 10 back and forth, the condition of the dry film resist on the substrate was confirmed, and the diameter of the corresponding round rod where the dry film was not peeled off or cracked was recorded.

[0160] For dry film resist with a film thickness of 25um, the judgment criteria are: ○: 3 mm without cracks △: 4 mm without cracks ×: 5 mm and above without cracks.

[0161] For dry film resist with a film thickness of 90um, the judgment basis is: ○: 10 mm without cracking △: 14 mm without cracking ×: 18 mm and above without cracking.

[0162]

Evaluation of sensitizer mobility

[0163] After the prepared three-layer photosensitive dry film is placed at 30°C for 48 hours, the ultraviolet absorption spectrum of the dry film is detected by an ultraviolet spectrophotometer to obtain the absorbance A1 of the maximum absorption peak in 350-450nm; the PE film layer on the surface of the photosensitive dry film is removed, and the ultraviolet absorption spectrum of the PET layer and the photosensitive resist layer is detected by an ultraviolet spectrophotometer to obtain the absorbance A2 of the maximum absorption peak in 350-450nm. If the sensitizer migrates to the surface of the PE layer, the absorbance of the maximum absorption peak of the PET layer and the photosensitive resist layer within the wavelength of 350-450nm will decrease, that is, the absorbance of the sensitizer that migrates to the PE layer is (A1-A2). Calculate the migration degree of the sensitizer, that is, the mobility A=(A1-A2) / A1, and the larger the value, the greater the migration amount.

[0164] Judgment basis: ○: mobility A<0.01; ×: Mobility A>0.01.

[0165]

Evaluation of sensitizer dissolution rate

[0166] Weigh 0.5g of anthracene sensitizer solid compound into a transparent glass bottle, add 10g of acetone, and place it in a 30℃ water bath. Observe and record the time it takes for the solid material to completely dissolve from the time it is placed in the water bath. The shorter the time, the faster the dissolution rate.

[0167] Judgment basis: ○: completely dissolved within 1 hour; △: Completely dissolved within 2 to 3 hours; ×: Completely dissolved or still not completely dissolved after more than 5 hours.

[0168] [Evaluation of the amount of developer sediment]

[0169] Peel off the dried photosensitive resin layer, and weigh 18g of photosensitive layer resist and dissolve it in 1L of 1% Na2CO3 developer. After the photosensitive layer is completely dissolved, pour the solution into a micro developer, spray and circulate at 30℃ / 0.12MPa pressure for 90 minutes, then stop the circulation. Take out the circulating developer and let it stand for 7 days, then filter out the precipitate with filter paper, dry and weigh it, and examine the weight of the precipitate on the filter paper and the percentage value of the initial 18g photosensitive layer.

[0170] Judgment basis

[0171] ○:0-0.4%

[0172] △: 0.4%-0.8%

[0173] ×:>0.8%

[0174]

Evaluation of side morphology

[0175] For high-thickness resist, the resist thickness is 90um. After removing the PE film of the manufactured photosensitive dry film resist, the dry film is laminated on the copper plate using a heated pressure roller. After 15 minutes of exposure, it is exposed using a mask with a wiring pattern with a width of n:400 between the exposed and unexposed parts. The exposure energy is 20 grids corresponding to the sensitivity. After developing with 2.0 times the minimum development time, the obtained dry film image is magnified 1000 times using a scanning electron microscope (SEM) to take a side view of the dry film with a line width of 25 um. The results are shown in Figure 1 .

[0176] Judgment basis: ○: The cross section of the dry film head is rectangular; △: The cross section of the dry film head is somewhat inverted trapezoidal; ×: The cross-section of the dry film head is severely trapezoidal or the bottom is hollowed out, or there are obvious cracks on the side wall.

[0177] (3) The results of performance evaluation such as sensitivity, resolution, adhesion, side morphology, and initiator migration are shown in Tables 5 to 7.

[0178] Table 5

[0179] Table 6

[0180] Table 7

[0181] By comparing Examples 1-20 with Comparative Examples 1-3, it can be found that Examples 1-20 all obtained dry film resists suitable for making high-end PCBs such as carriers and carrier-like boards with excellent key comprehensive performances such as sensitivity, resolution, adhesion performance, flexibility level, no initiator migration, and development precipitation. Moreover, Examples 14-16 did not add the hydrogen donor-leuco crystal violet commonly used in the carrier resist formula, and the implementation results showed that the sensitivity of the corresponding resist was basically unaffected.

[0182] Comparative Examples 1 to 3 have relatively obvious deficiencies in the undesirable phenomenon of DBA migration to the polyethylene protective film, the flexibility, resolution, and adhesion of the dry film resist.

[0183] As for the performance of high-thickness resists, by comparing Examples 21-35 with Comparative Examples 4-7, it can be found that Examples 21-35 all achieved key comprehensive performance such as sensitivity, flexibility level, no initiator migration, and development precipitation. Even if the film thickness reaches 90um, the resolution and adhesion performance are excellent, and an extremely high aspect ratio is achieved. The side morphology is steep and there is no inverted trapezoidal phenomenon, which fully meets the performance requirements of dry film resists for special usage scenarios such as long copper pillars and mSAP thick copper plating.

[0184] However, Comparative Examples 4-7 have obvious relative deficiencies to varying degrees in terms of the undesirable phenomenon of DBA migration to the polyethylene protective film, the flexibility, resolution, and adhesion of the dry film resist, etc.

[0185] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A photosensitive resin composition, characterized in that: Including alkali soluble resin, photopolymerization monomer, photoinitiator and sensitizer; The sensitizer is selected from one or more compounds represented by structural formulas AN-1 to AN-7: Wherein, Z is selected from any one of a nitrogen atom, an oxygen atom or a sulfur atom; when Z is selected from a nitrogen atom, the nitrogen atom carries a hydrogen atom or a methyl group; X represents any one of a hydrogen atom, a halogen, a nitro group, an alkyl group with a carbon chain length of C1 to C8, an alkoxy group with a carbon chain length of C1 to C4, a phenyl group, an alkanoyl group with a carbon chain length of C1 to C4, or an ester group with a carbon chain length of C1 to C4 on the anthracene ring; Y represents that the benzene ring can be independently selected from any one of hydrogen atom, halogen, alkanoyl with a carbon chain length of C1 to C4, ester group with a carbon chain length of C1 to C4, nitro group, alkyl group with a carbon chain length of C1 to C8, alkoxy group with a carbon chain length of C1 to C4, phenyl, amide group, trifluoromethyl group or cyano group; the benzene ring connected to Y can be selected from other aromatic rings; Ra and R' each independently represent an alkyl group with a carbon chain length of C1 to C4; Rx is selected from any one of a hydrogen atom or a methyl group; "C n H 2n O" and "C m H 2m O" represents a structural unit of a diol or a polyether diol, wherein m and n each independently represent an integer of 1 to 6, and a1 and a2 each independently represent an integer of 0 to 20.

2. The photosensitive resin composition according to claim 1, characterized in that: The sensitizer is further selected from one or more compounds represented by structural formulas D-1 to D-19: Among them, R1~R 18 Each is independently selected from any one of a hydrogen atom or a methyl group; X1~X 18 Each independently represents any one of a hydrogen atom, a halogen, a nitro group, an alkyl group with a carbon chain length of C1 to C8, an alkoxy group with a carbon chain length of C1 to C4, a phenyl group, an alkanoyl group with a carbon chain length of C1 to C4, or an ester group with a carbon chain length of C1 to C4 on the anthracene ring; Y1~Y7 each independently represents a benzene ring selected from any one of a hydrogen atom, a halogen, an alkanoyl group with a carbon chain length of C1-C4, an ester group with a carbon chain length of C1-C4, a nitro group, an alkyl group with a carbon chain length of C1-C8, an alkoxy group with a carbon chain length of C1-C4, a phenyl group, an amide group, a trifluoromethyl group or a cyano group; the benzene ring to which Y1~Y3 is connected may be other aromatic rings; R, Ra, Ra1, Ra2, R', R'1, R'2 each independently represent an alkyl group with a carbon chain length of C1 to C4; "C n H 2n O" and "C m H 2m O" represents a structural unit of a diol or a polyether diol, wherein m and n each independently represent an integer of 1 to 6, and a1 and a2 each independently represent an integer of 0 to 20. More preferably, the mass percentage of the sensitizer in the photosensitive resin composition is 0.05% to 1.5%.

3. The photosensitive resin composition according to claim 1, characterized in that: The photoinitiator includes a hexaarylbisimidazole derivative; Preferably, the hexaarylbiimidazole derivative has a structural formula as shown in formula (I): （I） In formula (I), the substituents A on the benzene rings are each independently selected from a hydrogen atom, a methoxy group, and a halogen atom, and the number and type of the substituents on each benzene ring may be the same or different; More preferably, the photoinitiator is selected from one or more of 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole; More preferably, the photoinitiator further includes one or more of pyrazoline compounds, acridine compounds, quinone compounds, aromatic ketone compounds, benzoin ether compounds, oxime ester compounds, coumarin compounds, and triarylamine compounds.

4. The photosensitive resin composition according to claim 1, characterized in that: The alkali-soluble resin has a structure as shown in the general formula (A1): （A1） Wherein, Ra1, Ra2, Ra3, and Ra4 are each independently represented by a hydrogen atom or a methyl group; Rb1 and Rb2 each independently represent a hydrogen atom, an alkyl group with a carbon chain length of C1 to C5, an alkoxy group with a carbon chain length of C1 to C5, a hydroxyl group or a halogen atom, and x and y each independently represent any integer from 0 to 5; Rc is selected from C5~C 14 Substituted or unsubstituted monocyclic carbocyclic alkyl, C5~C 14 Substituted or unsubstituted bicyclic carbocyclic alkyl, C5~C 14 Substituted or unsubstituted polycyclic carbocyclic alkyl, C5~C 14 Substituted or unsubstituted monocyclic heterocycloalkyl, C5~C 14 Substituted or unsubstituted bicyclic heterocycloalkyl, C5~C 14 Any one of substituted or unsubstituted polycyclic heterocycloalkyl, wherein the bicyclic carbocycloalkyl and the polycyclic carbocycloalkyl have a cyclic structure or a bridged ring structure; a, b, c, d represent the weight of each copolymer component in the alkali-soluble resin, wherein a is 20-35wt%, b is 0-60wt%, c is 0-60wt%, d is 0-40wt%; More preferably, the alkali-soluble resin contains alicyclic alkane (meth)acrylate structural units and / or contains benzyl ester or phenoxyethyl (meth)acrylate structural units; The alicyclic alkane (meth) acrylate structural unit includes: 1-adamantane (meth) methacrylate, 2-adamantane (meth) methacrylate, (meth) acrylic acid tricyclo [5.2.1.02,6] decane-8-yl ester, 2-methyl-2-adamantane alcohol acrylate, 2-ethyl-2-adamantane alcohol acrylate, 2-carboxy-4-norbornyl lactone-5-methacrylate, 2-isopropyl-2-adamantane alcohol (meth) acrylate, isobornyl acrylate, acryloyl morpholine, 1-adamantyl methacrylate, 3-hydroxy-1-adamantane (meth) propionate, cyclohexane dicarboxylic acid imide acrylate, 2-cyclohexyl methacrylate, methacrylate-5-oxotetrahydrofuran-3-yl ester, 5-carboxy One or more of 2-tetrahydrofuranmethanol-methacrylate, 1-ethylcyclopentyl methacrylate, 1-isopropyl-1-cyclohexanol methacrylate, 2-cyclohexyl-2-propanol methacrylate, 2-carbonyl-tetrahydrofuran-3-hydroxy-methacrylate, methylcyclopentyl acrylate, 1-ethylcyclopentyl acrylate, 2-oxotetrahydrofuran-3-yl acrylate, cyclohexyl (meth) acrylate, 1-methyl-1-cyclohexyl methacrylate, 1-methylcyclopentyl methacrylate, 1-ethylcyclohexyl methacrylate, 1-methyl-1-ethyl-1-adamantane methacrylate, 2-tetrahydrofuranyl methacrylate, 2-methacrylate-4-hydropyran, and dicyclopentyl methacrylate; The (meth)acrylate structural unit containing benzyl ester or phenoxyethyl ester includes one or more of benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, and o-phenylphenoxyethyl acrylate. Preferably, the alkali-soluble resin has an acid value of 130 to 275 mg KOH / g, a weight average molecular weight of 25,000 to 60,000, and a molecular weight distribution of 1.3 to 2.

5.

5. The photosensitive resin composition according to claim 1, characterized in that: The photopolymerizable monomer contains at least one EO or PO modified (meth)acrylate as shown in the general formula (B1), (B2), (B3), (B4); （B1） In the formula, R1 is selected from any one of a hydrogen atom and a methyl group, m1 and m2 each independently represent any integer from 1 to 20, n1 and n2 each independently represent any integer from 0 to 20, m1+m2 is any integer from 2 to 20, n1+n2 is any integer from 0 to 20, and the arrangement of EO and PO repeating units can be random or block; （B2） In the formula, R1 is selected from any one of a hydrogen atom or a methyl group, and a1, b1, and c1 each independently represent any integer of 3 to 10; (B3) In the formula, R1 is selected from any one of a hydrogen atom or a methyl group, a2 is any integer from 3 to 20, b2 is any integer from 0 to 20, c2 is any integer from 3 to 20, and the arrangement of EO and PO repeating units can be random or block; (B4) In the formula, R1 is selected from any one of a hydrogen atom or a methyl group, a3 is any integer from 4 to 10, and L is any integer from 5 to 15; Preferably, the photopolymerizable monomer further comprises a monofunctional, difunctional or polyfunctional (meth)acrylate ethylenically unsaturated double bond monomer; More preferably, the photopolymerizable monomer includes one or more of lauryl (meth)acrylate, octadecyl (meth)acrylate, nonylphenol acrylate, isobornyl, tetrahydrofuran methyl acrylate, bisphenol A di(meth)acrylate, polyethylene glycol (propylene glycol) di(meth)acrylate, ethoxylated (propoxylated) neopentyl glycol diacrylate, trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) trimethylolpropane tri(meth)acrylate, ethoxylated (propoxylated) pentaerythritol triacrylate, ethoxylated (propoxylated) pentaerythritol tetraacrylate, ethoxylated (propoxylated) dipentaerythritol pentaacrylate, and ethoxylated (propoxylated) dipentaerythritol hexaacrylate.

6. The photosensitive resin composition according to claim 1, characterized in that: It also includes additives, which are selected from one or more of free radical inhibitors, dyes, plasticizers, light and heat stabilizers, adhesion promoters, leveling agents, and defoamers; Preferably, the mass percentage of the additive in the photosensitive resin composition is 0.5% to 5.0%.

7. The photosensitive resin composition according to claim 6, characterized in that: The free radical inhibitor is selected from p-methoxyphenol, 4-ethyl-6-tert-butylphenol, tert-butylcatechol, 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl, nitrosophenylhydroxylamine aluminum salt, 2-methylcatechol, 3-methylcatechol, 4-methylcatechol, catechol, 2-ethylcatechol, 3-ethylcatechol, 4-ethylcatechol, 2-propylcatechol, 3-propylcatechol, 4-propylcatechol, 2-n-butylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 2-tert-butylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, 3,5-di-tert-butyl One or more of catechol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 2-ethylresorcinol, 4-ethylresorcinol, 2-propylresorcinol, 4-propylresorcinol, 2-n-butylresorcinol, 4-n-butylresorcinol, 2-tert-butylresorcinol, 4-tert-butylresorcinol, 1,4-hydroquinone, methylhydroquinone, ethylhydroquinone, propylhydroquinone, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-4-methylphenol, pyrogallol, 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl, 2,2-methylenebis(4-methyl-6-tert-butylphenol); Preferably, the mass percentage of the free radical inhibitor in the photosensitive resin composition is 0.001% to 0.05%.

8. The photosensitive resin composition according to any one of claims 1 to 7, characterized in that: In parts by weight, it comprises: (A) 45 to 65 parts of alkali-soluble resin, (B) 33 to 50 parts of photopolymerizable monomer, (C) 1.5 to 4.0 parts of photoinitiator, (D) 0.05 to 1.5 parts of sensitizer, and (E) 0.5 to 5 parts of additives; It is preferred that the total weight of (A) the alkali-soluble resin, (B) the photopolymerizable monomer, (C) the photoinitiator, (D) the sensitizer and (E) the additive is 100 parts.

9. A photosensitive dry film, characterized in that: The photosensitive dry film comprises a support layer and a photosensitive resist layer, and the photosensitive resist layer is prepared from the photosensitive resin composition according to any one of claims 1 to 8.

10. Use of the photosensitive resin composition according to any one of claims 1 to 8 or the photosensitive dry film according to claim 9 in the manufacturing process of a printed circuit board, a lead frame or a flexible circuit board.

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