Photosensitive resin composition containing alkynyl anthracene photosensitizer and application thereof

Abstract

The invention provides a photosensitive resin composition containing an alkynyl anthracene photosensitizer and application of the photosensitive resin composition. A conjugated alkynyl functional group is introduced to the 9 and / or 10 position of a structural main body anthracene ring of the photosensitizer. Compared with the existing DBA photosensitizer, the introduction of alkynyl expands the size of a conjugated system, lengthens the maximum absorption wavelength of molecules, improves the initiation efficiency, is especially suitable for a photo-initiation system under the 405nm illumination condition, reduces the exposure energy, and also ensures good solubility and compatibility of a formula; besides, compared with an existing DBA photosensitizer, small molecule fragments cannot be generated and cannot be migrated to a polyethylene film, and when an electroplating procedure is carried out after exposure and development, the fragments cannot be separated out to pollute electroplating liquid, so that the undesirable phenomena of short circuit, open circuit and the like of an anti-corrosion pattern are avoided, and the yield of a product is remarkably improved; the method can be widely applied to the photo-curing fields of dry films, paints, coatings, printing ink, forming materials and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of photosensitive resins, and in particular, relates to a photosensitive resin composition comprising an alkynyl anthracene photosensitizer and an application thereof. Background Art

[0002] The photosensitive resin composition is usually coated on the surface of a polyester (PET) support film, and after drying, a polyethylene (PE) film protective layer is attached to the surface to form a photosensitive dry film (or dry film resist). This type of material has important application value as a core material for pattern transfer in etching or electroplating processes in the fields of printed circuit boards (PCBs), lead frames (LFs), semiconductor packages (ICs), and solar cells. Its typical process flow includes: attaching the dry film resist to the surface of a copper substrate, exposing the pattern through a mask; removing the unexposed area with a weak alkaline developer; forming the target pattern by etching or electroplating; and finally stripping the cured dry film with a film stripper to complete the pattern transfer. In this process, the performance of the photosensitive dry film directly determines the accuracy, resolution, and production efficiency of the pattern transfer, and the performance of the photoinitiator, as the core component of the photocuring reaction, has a decisive influence on the energy utilization efficiency of the photosensitive layer, the edge clarity of the pattern, and the production yield. Therefore, the design and synthesis of new photoinitiators and the research on the formulation of high-performance photosensitive resin compositions with this as the core have always been one of the hot topics in this field.

[0003] At present, small molecule anthracene derivatives represented by 9,10-dibutoxyl Anthracene (DBA) are widely used as photoinitiators. Usually, in order to obtain higher photosensitivity and resolution, DBA needs to be used in combination with 2,4,5-triaryl imidazole dimer (HABI) (such as patent CN101568883B); however, when DBA is used alone as a photoinitiator, its photoquantum yield still needs to be improved, and the utilization efficiency of exposure energy is limited, resulting in extended exposure time and reduced production efficiency. Although such problems can be solved by conventional means such as increasing the amount of addition, it will bring more problems:

[0004] 1) The initiation mechanism of short-chain alkoxyanthracene derivatives causes the fragments after initiation to migrate easily in the dry film and penetrate into the surface of the polyethylene (PE) protective film to form crystals, thereby causing defects such as short circuits and disconnections in the resist pattern, or the risk of decreased photosensitivity due to the penetration of photosensitizers from the photosensitive layer;

[0005] 2) During the development process, it is easy to gather in the developer to produce sediment garbage, which is easy to adhere to the surface of the copper plate, causing problems such as residual copper or short circuit, affecting the product yield.

[0006] Therefore, developing a new photoinitiator system with high photoquantum yield, low migration characteristics and excellent development compatibility, and constructing a high-performance photocurable resin composition based on it, has become a technical problem to be solved urgently in this field. Summary of the invention

[0007] Therefore, the purpose of the present invention is to develop a 9- and / or 10-alkynyl anthracene-based photoinitiator and a photosensitive resin composition, a dry film resist and a photosensitive dry film suitable therefor, so as to overcome the photosensitizer migration problem existing in existing dry film products, while reducing development waste, improving the photoquantum yield of the initiator and reducing exposure energy.

[0008] After extensive literature research and experimental studies, the present invention has found the following problems and proposed innovative improvement plans: Anthracene compounds or anthracene derivatives can undergo dimerization under light due to their unique structure, thereby being photobleached. This characteristic effectively avoids the problem of excessive energy absorption by the upper photosensitizer during exposure, and enables the bottom layer photosensitive resin composition to receive light more fully, so that the photosensitive resin composition can be uniformly cured during exposure and achieve better resolution. For example, patent CN101218538B discloses 9,10-dialkoxy anthracene photosensitizers, CN110446976B discloses alkoxy anthracene or phenyl anthracene photosensitizers, and CN116300313A discloses 9,10-diacyloxy anthracene or 9,10-diphenyloxy anthracene photosensitizers. The above anthracene photosensitizers all have good resolution and adhesion.

[0009] However, the present invention finds that: when exposed, the CO bond at the 9,10 position of the 9,10-dialkoxyanthracene photosensitizer will break, the anthracene ring will dimerize, and a small molecule alkoxy fragment will be released. This small molecule fragment will migrate from the cured photosensitive resin composition to the electroplating solution in the subsequent electroplating process, causing pollution, affecting the life of the plating solution and the electroplating effect; 9,10-diacyloxyanthracene photosensitizers increase the electron cloud density of the 9,10 anthracene ring due to the electron-pulling induction effect of the acyloxy group, so that the efficiency of this type of photosensitizer decreases when catalyzing the curing reaction, the verticality of the side wall of the cured photosensitive resin composition is not good, and the difference between the top and bottom line lengths is large, forming an "inverted trapezoid" problem, and the energy required for this type of photoinitiator during exposure increases, and the photobleaching efficiency decreases; 9,10-diaryl anthracene photosensitizers, due to their rigid molecular structure, have greatly reduced solubility, which has a great impact on the uniformity and consistency of the product.

[0010] Based on the above findings, the present invention proposes a photosensitizer based on 9 and / or 10-alkynyl anthracene, and a photosensitive resin composition adapted thereto, which can reduce the initiator migration problem existing in existing dry film products, thereby reducing development waste, improving the photoquantum yield of the initiator, and reducing exposure energy.

[0011] (I) Photosensitive resin composition

[0012] The first aspect of the present invention provides a photosensitive resin composition, which comprises the following components based on 100 parts by mass of the photosensitive resin composition: (A) 50-65 parts of an alkali-soluble resin; (B) 35-50 parts of a photopolymerizable monomer selected from ethylenically unsaturated carboxylic acids and / or ethylenically unsaturated carboxylic acid esters; (C) 2-5 parts of a photoinitiator selected from bisimidazole compounds; and (D) 0.1-1 parts of a photosensitizer, wherein the photosensitizer is an alkynyl anthracene compound having a structure represented by formula (I) or formula (II):

[0013]

[0014] (I) (II)

[0015] Wherein, R1 and R2 are each independently selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C12 aryl, C6-C12 aryl substituted by C1-C6 alkyl, C6-C12 aryl substituted by C1-C6 alkoxy; R3 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl and halogen; X is halogen, wherein the photosensitive resin composition is photocured by the following photoinduced free radical polymerization mechanism: the alkynyl anthracene compound is excited by visible light to generate anthracene radicals, which induce homolysis of the bisimidazole compound to generate imidazole radicals, and the imidazole radicals activate the ethylenically unsaturated carboxylic acid and / or ethylenically unsaturated carboxylic acid ester to cause cross-linking and curing.

[0016] Specifically, the photocuring process follows the mechanism of photoinduced free radical polymerization reaction: the first step is that the alkynyl anthracene compound as a photosensitizer is excited to produce anthracene free radicals after absorbing photons; the second step is that the anthracene free radicals cause the bisimidazole compound as a photoinitiator to split and produce imidazole free radicals; the third step is the curing stage: the imidazole free radicals react with the olefinically unsaturated carboxylic acid and / or olefinically unsaturated carboxylic acid ester to open the unsaturated bonds of the activated monomer, a cross-linking reaction occurs, and a 3D network structure is formed, so that the material can be rapidly cured and hardened.

[0017] In the present invention, the halogen is preferably chlorine or bromine.

[0018] (A) Alkali soluble resin

[0019] According to the photosensitive resin composition provided by the present invention, the alkali-soluble resin is an acrylate copolymer containing an aromatic group. From the perspective of improving the resolution and chemical resistance of the product, preferably, the copolymerization ratio of the copolymer having an aromatic group is 50-70% based on the total mass of the copolymerized monomers during the copolymerization process.

[0020] In some embodiments of the present invention, the alkali-soluble resin is obtained by copolymerization of one or more of (meth)acrylic acid, (meth)acrylic acid alkyl esters, (meth)acrylic acid benzyl ester, (meth)acrylic acid benzyl ester derivatives, (meth)acrylic acid phenyl ester, styrene, and styrene derivatives. In some embodiments of the present invention, the alkali-soluble resin is copolymerized with (meth)acrylic acid and copolymerization units, and the copolymerization units are selected from one or more of (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid benzyl ester, (meth)acrylic acid phenyl ester, (meth)acrylic acid hydroxyethyl ester, and styrene. In some specific embodiments of the present invention, the comonomers of the alkali-soluble resin include methacrylic acid, methyl methacrylate, hydroxyethyl methacrylate, benzyl methacrylate, and styrene.

[0021] Further, the weight average molecular weight of the alkali soluble resin is 20000-60000, the resin acid value is 160-220mg KOH / g, and the molecular weight distribution index is 1.0-3.0. In an embodiment of the present invention, the content of the alkali soluble resin is 50-65 parts by mass, preferably 55-60 parts by mass. If the content is less than 50 parts by mass, there is a tendency for the resist laminar flow glue, and if the content exceeds 65 parts by mass, there is a tendency for the resolution to decrease.

[0022] (B) Photopolymerizable monomers

[0023] According to the photosensitive resin composition provided by the present invention, the photopolymerizable monomer is a monomer having an ethylenically unsaturated double bond, preferably selected from (meth) acrylate monomers. In a preferred embodiment of the present invention, the photopolymerizable monomer is selected from methoxy polyethylene glycol monoacrylate, ethoxy (propoxy) nonylphenol acrylate, ethoxy (propoxy) bisphenol A di(meth) acrylate, ethoxy (propoxy) di(meth) acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, ethoxy (propoxy) trimethylolpropane tri(meth) acrylate, di(trimethylolpropane) tetraacrylate, ethoxy (propoxy) pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, or more thereof.

[0024] In the embodiment of the present invention, the content of the photopolymerizable monomer is 35-50 parts by mass, preferably 40-50 parts by mass, and more preferably 45-50 parts by mass. If the content is less than 35 parts by mass, there is a tendency for the sensitivity and chemical resistance of the resist to decrease, and if the content exceeds 50 parts by mass, there is a tendency for the photosensitive resin composition to be difficult to be filmed and the resist to have laminar flow glue.

[0025] (C) Photoinitiator

[0026] According to the photosensitive resin composition provided by the present invention, the photoinitiator is a biimidazole compound, for example, it can be a 2,4,5-triaryl imidazole dimer. Typical biimidazole compounds, such as hexaaryl biimidazole (HABI): as a representative of biimidazole photoinitiators, its maximum absorption peak is located at 255-275 nm, and it is insensitive to long-wave ultraviolet light (such as 365 nm) and visible light; for example, 2-(2-hydroxyphenyl) benzimidazole) absorbs at 320-380 nm and can match UV-A light sources (such as 365 nm LEDs), but is insensitive to the visible light region of 405 nm. The present invention successfully adjusts the working wavelength of the biimidazole photoinitiator to about 405 nm by using an alkynyl anthracene photosensitizer that can be excited under 405 nm illumination conditions.

[0027] In a preferred embodiment of the present invention, the photoinitiator is selected from one or more of 2-(2-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0028] In the embodiment of the present invention, the content of the photoinitiator is 2-5 parts by mass, preferably 2-4 parts by mass, and more preferably 2.5-3.5 parts by mass. If the content is less than 2 parts by mass, the sensitivity and resolution of the resist tend to decrease, and if the content exceeds 5 parts by mass, the amount of development waste tends to increase.

[0029] (D) Photosensitizer

[0030] According to the photosensitive resin composition provided by the present invention, in the alkynyl anthracene compound of the formula (I) structure as a photosensitizer, a conjugated alkynyl functional group is introduced at the 9 and / or 10 position. Compared with the existing DBA photoinitiator, the introduction of the alkynyl group expands the size of the conjugated system, lengthens the maximum absorption wavelength of the molecule, improves the initiation efficiency (especially suitable for the photoinitiator system under 405 nm illumination conditions), reduces the exposure energy, and also ensures good solubility and compatibility of the formulation (chain alkynyl group). In addition, compared with the existing DBA photoinitiator, it does not produce small molecule fragments and can be widely used in the field of photocuring such as dry film, paint, coating, ink and molding materials.

[0031] In a preferred embodiment of the present invention, the photosensitizer is selected from one or more of 9,10-bis(oxiran-2-ylmethoxy)anthracene, 9,10-bis(oxiran-2-ylmethoxy)-2-ethylanthracene, 9,10-bis(oxiran-2-ylmethoxy)-2-chloroanthracene, 9,10-bis(3-(oxiran-2-yl)propoxy)anthracene, 9,10-bis(4-(oxiran-2-yl)butoxy)anthracene, 9,10-bis(5-(oxiran-2-yl)pentyloxy)anthracene, and 9,10-bis(6-(oxiran-2-yl)hexyloxy)anthracene.

[0032] In some specific embodiments of the present invention, the photosensitizer may have one of the following structures:

[0033] .

[0034] In the embodiment of the present invention, the content of the photosensitizer is 0.1-1 parts by mass, preferably 0.1-0.8 parts by mass, and more preferably 0.2-0.5 parts by mass. If the content is less than 0.1 parts by mass, the sensitivity of the resist tends to decrease, and if the content exceeds 1 part by mass, the resist bottom layer tends to be incompletely cured, resulting in a "reverse trapezoidal" cross-sectional shape of the resist and poor resolution.

[0035] The alkynyl anthracene photosensitizer of the present invention can be prepared by conventional synthesis methods in the art. For example, the alkynyl anthracene compound can be prepared by a Sonogashira coupling reaction of 9,10-dibromoanthracene and a terminal alkyne compound under the conditions of Pd(II) and Cu(I) co-catalysis, and the general reaction formula is shown in the following reaction:

[0036]

[0037] Wherein: [Pd] is a common metal palladium catalyst, such as: Pd(OAc)2, Pd(PhCO2)2, Pd(CF3CO2)2, PdCl2, PdBr2, Pd(PPh3)2Cl2, Pd(PPh3)4, and other metal palladium complexes containing different ligands, such as di(acetic acid)(o-phenanthroline)palladium (cas: 35679-81-3, Shanghai Haohong Biotechnology Co., Ltd.), bis(acetonitrile)palladium(II) (cas: 114757-66-3, Shanghai Aladdin Biochemical Technology Co., Ltd.), allyl(cyclopentadiene)palladium(II) (cas: 1271-03-0, Beijing Bailingwei Technology Co., Ltd.), etc., preferably Pd(PPh3)2Cl2. Cu(I) is a cuprous salt, such as CuCl, CuBr, CuI, CuOAc, cuprous sulfate, cuprous diphenyl phosphate, cuprous trifluoromethanesulfonate, cuprous bromide dimethyl sulfide, cuprous tetrafluoroborate, etc., preferably CuI. Base is an alkaline compound, such as Na2CO3, NaHCO3, K2CO3, KHCO3, Cs2CO3, (NH4)2CO3, NaOH, KOH, CsOH, NaOCH3, KOCH3, t-BuONa, t-BuOK, triethylamine, triphenylamine, diisopropylamine, etc., preferably triethylamine. Sol. is an organic solvent, such as dichloromethane, chloroform, 1,2-dichloroethane, ethyl acetate, tetrahydrofuran, benzene, toluene, chlorobenzene, nitrobenzene, 1,4-dioxane, DMSO, DMF, etc., preferably toluene. T. is the reaction temperature, the temperature range is 45-150°C, preferably 75-90°C. t is the reaction time, which ranges from 2 to 48 h, preferably from 4 to 8 h.

[0038] The typical reaction operation is as follows: under nitrogen atmosphere, 9,10-dibromoanthracene (0.5 mmol) and alkynyl derivatives are added in a molar ratio of about 1:3 to a round-bottom flask equipped with a magnetic stirrer, followed by palladium catalyst (5 mol%) and cuprous catalyst (20 mol%), and base (2.0 equiva.), and finally dry solvent (3.5-5.0 ml) for reaction. After the reaction is monitored by thin layer chromatography (TLC), the reaction system is washed with saturated ammonium chloride and saturated brine in turn, the organic phase is collected, dried over anhydrous sodium sulfate, and purified by column chromatography, with a yield of 40%-99%.

[0039] (E) Other additives

[0040] In an embodiment of the present invention, the photosensitive resin composition may further include one or more additives selected from dyes, photodevelopers, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, and coating aids as needed. Preferably, the total amount of the additives is 0.5-5.0 parts by mass.

[0041] (ii) Photosensitive dry film

[0042] The second aspect of the present invention provides a photosensitive dry film, which includes from bottom to top: a supporting layer; a photosensitive resist layer attached to the surface of the supporting layer; and a protective layer attached to the surface of the photosensitive resist layer, wherein the photosensitive resist layer is formed using the photosensitive resin composition provided by the first aspect of the present invention.

[0043] In some preferred embodiments of the present invention, the photosensitive dry film comprises from bottom to top: a PET support layer, a photosensitive resist layer formed by coating and drying the photosensitive resin composition provided by the first aspect of the present invention on the surface of the PET support layer, and a PE protective layer.

[0044] (III) Application of photosensitive dry film

[0045] The third aspect of the present invention provides the use of the above-mentioned photosensitive dry film in printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, photocurable inks, etc.

[0046] The present invention has the following beneficial effects: the photosensitizer of the present invention can reduce exposure energy, improve photosensitivity, and utilize exposure light source energy more efficiently compared to the existing 9,10-dibutoxyanthracene (DBA), thereby shortening exposure time and improving production efficiency. At the same time, the present invention meets the needs of high-precision circuit manufacturing on the basis of maintaining or exceeding the high-resolution level of DBA, making the graphics clearer and sharper, and is suitable for miniaturized and high-density electronic device production. In addition, by optimizing the photosensitivity, the defects caused by insufficient or excessive exposure are effectively reduced, the scrap rate is reduced, and the production yield is significantly improved. In addition to the above-mentioned purposes, features and advantages, the present invention also has other potential technical advantages and provides a better solution for the development of related fields. In summary, the photosensitive dry film provided by the present invention has excellent resolution and adhesion, and has a higher sensitivity than the photosensitive resin composition to which the 9,10-dibutoxyanthracene photosensitizer is added, which is conducive to improving the production efficiency of the client and meeting the needs of high density and high precision of printed circuit boards. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0048] Figure 1 is the photosensitizer D1 prepared in Example 1 of the present invention 1 H NMR spectrum;

[0049] Figure 2 is the photosensitizer D1 prepared in Example 1 of the present invention 13 C NMR spectrum;

[0050] Figure 3 is the photosensitizer D2 prepared in Example 2 of the present invention 1 H NMR spectrum;

[0051] Figure 4 is the photosensitizer D2 prepared in Example 2 of the present invention 13 C NMR spectrum;

[0052] Figure 5 is the photosensitizer D3 prepared in Example 3 of the present invention 1 H NMR spectrum;

[0053] Figure 6 is the photosensitizer D3 prepared in Example 3 of the present invention 13 C NMR spectrum;

[0054] Figure 7 is the photosensitizer D4 prepared in Example 4 of the present invention 1 H NMR spectrum;

[0055] Figure 8 is the photosensitizer D4 prepared in Example 4 of the present invention 13 C NMR spectrum;

[0056] Fig. 9 It is the ultraviolet absorption spectra of the photosensitizers D1-D4 prepared in Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below in conjunction with specific embodiments. The given examples are only for illustrating the present invention, but not for limiting the scope of the present invention.

[0058] Example 1

[0059] Preparation of 9,10-dioctynthracene (photosensitizer D1)

[0060] Under nitrogen atmosphere, 9,10-dibromoanthracene (0.5 mmol) and octyne (1.5 mmol) were added in a molar ratio of 1:3 to a round-bottom flask equipped with a magnetic stirrer, followed by the addition of Pd(PPh3)2Cl2 (5 mol%) and CuI (20 mol%), as well as triethylamine (2.0 equivalents), and finally 4 ml of dry toluene, and the reaction was continued for a certain period of time. After the reaction was completed by monitoring by TLC, the reaction system was washed with saturated ammonium chloride and saturated brine in turn, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 85%). The structural formula of the product 9,10-dioctyneanthracene is as follows, where n C6H 13 To represent n-hexyl:

[0061]

[0062] 1 H NMR (400 MHz, CDCl3, 300 K): δ 8.60 (dd, J = 6.67, 3.31 Hz, 4H), 7.58 (dd, J = 6.70, 3.36 Hz, 4H), 2.77 (t, J = 7.07 Hz, 4H), 1.83 (p, J =7.21 Hz, 4H), 1.68 – 1.60 (m, 4H), 1.46 – 1.41 (m, 8H), 0.97 (t, J = 6.84 Hz,6H).

[0063] 13 C NMR (100 MHz, CDCl3, 300 K): δ 132.3, 127.4, 126.4, 118.7, 103.5,77.6, 31.6, 29.2, 29.0, 22.8, 20.4, 14.2.

[0064] Example 2

[0065] Preparation of 9,10-bis(phenylethynyl)anthracene (photosensitizer D2)

[0066] Under nitrogen atmosphere, 9,10-dibromoanthracene (0.5 mmol) and phenylacetylene were added in a molar ratio of 1:3 to a round-bottom flask equipped with a magnetic stirrer, followed by Pd(PPh3)2Cl2 (5 mol%) and CuI (20 mol%), as well as triethylamine (2.0 equivalents), and finally 4 ml of dry toluene, and the reaction was continued for a certain period of time. After the reaction was completed by TLC monitoring, the reaction system was washed with saturated ammonium chloride and saturated brine in turn, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 88%). The structural formula of the product 9,10-bis(phenylethynyl)anthracene (photosensitizer D2) is as follows:

[0067]

[0068] 1 H NMR (400 MHz, CDCl3, 300 K): δ 8.70 (d, J = 10.3 Hz, 4H), 7.79 (d, J= 7.12 Hz, 4H), 7.66 – 7.64 (m, 4H), 7.49 – 7.43 (m, 6H).

[0069] 13 C NMR (100 MHz, CDCl3, 300 K): δ 132.2, 131.8, 128.9, 128.7, 127.4,127.0, 123.5, 118.6, 102.5, 86.6.

[0070] Example 3

[0071] Preparation of 9-p-methoxyphenylethynyl-10-bromoanthracene (photosensitizer D3)

[0072] Under nitrogen atmosphere, 9,10-dibromoanthracene (0.5 mmol) and p-methoxyphenylacetylene were added to a round-bottom flask equipped with a magnetic stirrer at a molar ratio of 1:3, followed by Pd(PPh3)2Cl2 (5 mol%) and CuI (20 mol%), as well as triethylamine (2.0 equivalents) and finally 4 ml of dry toluene, and the reaction was continued for a certain period of time. After the reaction was completed by TLC monitoring, the reaction system was washed with saturated ammonium chloride and saturated brine in turn, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 75%). The structural formula of the product 9-p-methoxyphenylacetylene-10-bromoanthracene (photosensitizer D3) is as follows:

[0073]

[0074] 1H NMR (400 MHz, CDCl3, 300 K): δ8.67 (d, J = 9.94 Hz, 2H), 8.54 (d, J= 8.22 Hz, 2H), 7.70 (d, J = 7.31 Hz, 2H), 7.66 – 7.56 (m, 4H), 6.97 (d, J =7.56 Hz, 2H), 3.88 (s, 3H).

[0075] 13 C NMR (100 MHz, CDCl3, 300 K): δ 160.0, 133.2, 132.8, 130.3, 128.2,127.4, 127.3, 126.6, 123.6, 118.7, 115.5, 114.2, 102.0, 84.8, 55.4.

[0076] Example 4

[0077] Preparation of 9,10-di-p-methoxyphenylethynthracene (photosensitizer D4)

[0078] Under nitrogen atmosphere, 9-p-methoxyphenylethynyl-10-bromoanthracene (0.5 mmol) and p-methoxyphenylethynyl were added to a round-bottom flask equipped with a magnetic stirrer at a molar ratio of 1:2, followed by Pd(PPh3)2Cl2 (5 mol%) and CuI (20 mol%), as well as triethylamine (2.0 equivalents) and finally 4 ml of dry toluene. The reaction was allowed to proceed for a certain period of time. After the reaction was completed by monitoring by TLC, the reaction system was washed with saturated ammonium chloride and saturated brine in turn, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 90%). The structural formula of the product 9,10-di-p-methoxyphenylethynyl anthracene (photosensitizer D4) is as follows:

[0079]

[0080] 1 H NMR (400 MHz, CDCl3, 300 K): δ 8.69 (d, J = 7.19 Hz, 4H), 7.72 (d, J = 6.85 Hz, 4H), 7.63 (d, J = 7.18 Hz, 4H), 6.99 (d, J = 6.75 Hz, 4H), 3.89(s, 6H).

[0081] 13C NMR (100 MHz, CDCl3, 300 K): δ 160.1, 133.3, 132.1, 127.4, 126.8,118.6, 115.8, 114.4, 102.6, 85.5, 55.6.

[0082] Example 5

[0083] Preparation of photosensitive resin composition

[0084] Referring to the formula shown in Table 1, the components are mixed evenly to prepare a photosensitive resin composition. For the convenience of coating, solvent acetone can be added to adjust the viscosity to a proper level. Among them, blank means no addition.

[0085] Table 1

[0086] Note: The weights in Table 1 are calculated based on solid content and do not include solvent components.

[0087] The components of each component code in Table 1 are explained as follows:

[0088] Alkali soluble resin (A)

[0089] A1: Acrylate copolymer, solution polymerization, by mass ratio, methacrylic acid / butyl methacrylate / benzyl methacrylate = 25 / 10 / 65 polymerization; solvent is acetone, solid content 46%, weight average molecular weight 40000, dispersity 2.1, acid value 163mgKOH / g. (Hunan Chuyuan New Materials Co., Ltd.)

[0090] A2: Acrylate copolymer, solution polymerization, by mass ratio, methacrylic acid / ethyl methacrylate / styrene = 30 / 20 / 50 polymerization; solvent is acetone, solid content 47%, weight average molecular weight 55000, dispersity 2.3, acid value 195mgKOH / g. (Hunan Chuyuan New Materials Co., Ltd.)

[0091] A3: Acrylate copolymer, solution polymerization method, by mass ratio, methacrylic acid / ethyl methacrylate / benzyl methacrylate / styrene = 32 / 9 / 34 / 25 polymerization; solvent is acetone, solid content 47%, weight average molecular weight 25000, dispersity 1.9, acid value 208mgKOH / g. (Hunan Chuyuan New Materials Co., Ltd.)

[0092] Photopolymerizable monomer (B)

[0093] B1: Methoxypolyethylene glycol (350) monoacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0094] B2: 4 (ethoxy) nonylphenol acrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0095] B3: 10 (ethoxy) bisphenol A dimethacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0096] B4: 6 (propoxy) bisphenol A dimethacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0097] B5: Polyethylene glycol (400) diacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0098] B6: 3(ethoxy)trimethylolpropane triacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0099] B7: Di(trimethylolpropane) tetraacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0100] B8: 4 (ethoxy) pentaerythritol tetraacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0101] Photoinitiator (C)

[0102] C: 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-biimidazole (BCIM)

[0103] Photosensitizer (D)

[0104] D1: 9,10-Dioctynthracene

[0105] D2: 9,10-Bis(phenylethynyl)anthracene

[0106] D3: 9-p-methoxyphenylethynyl-10-bromoanthracene

[0107] D4: 9,10-dimethoxyphenylethynthracene

[0108] TM-1: 9,10-Dibutoxyanthracene

[0109] Additives (E)

[0110] E1: Leuco crystal violet (Annaiji Chemical)

[0111] E2: Malachite Green (Annaiji Chemical)

[0112] E3: p-Toluenesulfonamide (Annaiji Chemical)

[0113] E4: 2,6-di-tert-butyl-4-methylphenol (Annaiji Chemical)

[0114] Example 6

[0115] Preparation of photosensitive dry film

[0116] The photosensitive resin composition listed in Table 1 of Example 5 is used to prepare a photosensitive dry film, comprising the following steps: using an experimental device (model: AB4220, TQC of the Netherlands) to coat the photosensitive composition slurry prepared according to Table 1 on a 15 μm thick polyethylene terephthalate (PET) support film; baking at 80° C. for 10 minutes to remove the solvent, and after baking, the thickness of the photosensitive layer is controlled to be 30 μm, and then covered with a polyethylene film (PE) for protection to obtain a photosensitive dry film.

[0117] Example 7

[0118] Preparation of substrate with resist pattern

[0119] The photosensitive compositions of the present invention samples 1-7 and comparative samples 1-2 shown in Table 1 were used to prepare substrates with resist patterns, and the process was as follows:

[0120] (1) Photosensitive layer forming step: forming a photosensitive layer on a substrate using a photosensitive composition;

[0121] (2) an exposure step of irradiating a portion of the photosensitive layer with active light to photocuring the portion to form a cured product region;

[0122] (3) Development step: removing the portion of the photosensitive layer other than the cured product region from the substrate to form a resist pattern on the substrate.

[0123] The operating conditions of each process are described in detail below.

[0124] Photosensitive layer forming process: A copper-clad laminate laminated with a 35μm thick rolled 1.2mm thick copper foil is used. After surface adjustment and preheating to 80°C, the PE protective film of the photosensitive dry film obtained by each embodiment or comparative example is peeled off, and the above-mentioned photosensitive resin composition layer is laminated on the copper-clad laminate using a hot roller laminator (Zhisheng Technology Co., Ltd., CSL-M25E) at a roller temperature of 110°C, an air pressure of 0.35MPa, and a lamination speed of 1.5m / min to obtain a test substrate.

[0125] Exposure process: Use a direct drawing exposure machine (Core Micro, main wavelength 405nm) for exposure, use a Stouffer 41-level stage exposure ruler for sensitivity testing, and control the number of exposure grids at 14-18 grids.

[0126] Development process: After exposure, the PET support film is peeled off, and an alkali developer (manufactured by Guangzhou Julong Printed Board Equipment Co., Ltd., a developer for dry film) is used to spray a 1wt% Na2CO3 aqueous solution at 30°C for twice the minimum development time to dissolve and remove the unexposed part of the photosensitive resin layer. After development, it is washed with pure water for 1.5 times the development time, and after dehydration treatment with an air knife, it is dried with warm air to obtain a substrate with a cured film for evaluation. The shortest time required for the photosensitive resin layer in the unexposed part to be completely dissolved is the minimum development time.

[0127] Evaluation Project

[0128] 1. Photosensitivity evaluation

[0129] A Stouffer 41-level step exposure scale was placed on the above-mentioned film-attached test substrate for sensitivity testing. After the exposure process, the test substrate was left to stand for more than 20 minutes, and then the PET film layer was peeled off, and a 1.0wt% sodium carbonate aqueous solution was sprayed at 30°C to remove the unexposed resist layer. The development time was 2.0 times the minimum development time. After the above operation, a cured film obtained by curing the photosensitive resin composition was formed on the surface of the substrate. The exposure energy (mJ / cm 2 ), the sensitivity of the photosensitive resin composition was evaluated, and the smaller the value, the better the sensitivity.

[0130] 2. Adhesion evaluation

[0131] On the above-mentioned post-filming test substrate, a secondary lamination treatment (temperature: 120±5℃, pressure: 0.3±0.05 MPa, duration: 30±5 seconds) is first performed to enhance the bonding strength between the resist and the substrate to avoid distortion of the test results due to insufficient bonding strength. Using the photomask data with a wiring pattern with a line width / space width of n:400 (unit: μm), the energy is exposed to make the number of residual stages after the development of the Stouffer 41-level stage exposure ruler reach 16. After the development process, the resist pattern is observed using an optical microscope, and the adhesion is evaluated by taking the value of the minimum line width (unit: μm) that forms a complete cured resist line as the adhesion value. The smaller the value, the better the adhesion.

[0132] 3. Resolution evaluation

[0133] On the above-mentioned post-filming test substrate, a photomask data with a wiring pattern of line width / space width of n:n (unit: μm) was used to expose the energy so that the number of residual stages after development of the Stouffer 41-stage exposure ruler reached 16. After the development process, the resist pattern was observed using an optical microscope, and the adhesion (μm) was evaluated by taking the minimum line width of the complete cured resist line as the adhesion value. The smaller the value, the better the resolution.

[0134] 4. Resist shape evaluation

[0135] In the resist pattern used for the above-mentioned resolution evaluation, the portion with the best resolution was observed using a SU1000 scanning electron microscope (manufactured by Hitachi). Evaluation was performed according to the following evaluation criteria:

[0136] ■: The width difference between the top and bottom of the resist front cross section is less than or equal to 0.8 μm, and the inverted trapezoid is basically not observed;

[0137] ○: The width difference between the top and bottom of the resist front cross section is greater than 0.8 μm and less than 1.2 μm, and the cross section is slightly inverted trapezoidal;

[0138] ×: The difference in width between the top and bottom of the front cross section of the resist is greater than or equal to 1.2 μm, and the cross section is clearly inverted trapezoidal.

[0139] The test results of evaluation items 1-4 are summarized in Table 2 below.

[0140] Table 2

[0141]

[0142] The results in Table 2 show that the photosensitive resin compositions prepared using the photosensitizers D1-D4 of the present invention exhibit excellent performance in terms of sensitivity, adhesion, resolution, resist shape, and the like.

[0143] Samples 5-7 of the present invention in Table 1 can still obtain good performance by adjusting the types and proportions of the components, indicating that the photosensitizer of the present invention has wide applicability and can be used in combination with different raw materials.

[0144] In contrast, the 9,10-dibutoxyanthracene used in comparative sample 1 has poor photosensitivity. In order to achieve the same photosensitivity as in the example, at least 25% of photosensitizer needs to be added. In addition, the resist formed by curing tends to form an inverted trapezoid.

[0145] The above contents are only preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art may make various modifications and changes within the spirit and principles of the present invention, and any changes, equivalent substitutions or improvements within this scope shall be deemed to be covered by the protection scope of the present invention.

Claims

1. A photosensitive resin composition, based on 100 parts by mass of the photosensitive resin composition, comprising the following components: (A) 50-65 parts of an alkali-soluble resin; (B) 35-50 parts of a photopolymerizable monomer selected from ethylenically unsaturated carboxylic acids and / or ethylenically unsaturated carboxylic acid esters; (C) 2 to 5 parts of a photoinitiator selected from a bisimidazole compound; and (D) 0.1-1 parts of photosensitizer, in, The photosensitizer is an alkynyl anthracene compound having a structure represented by formula (I) or formula (II): (I) (II) wherein R1 and R2 are each independently selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C12 aryl, C6-C12 aryl substituted by C1-C6 alkyl, C6-C12 aryl substituted by C1-C6 alkoxy; R3 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl and halogen; X is halogen, The photosensitive resin composition is photocured by the following photoinduced free radical polymerization reaction mechanism: the alkynyl anthracene compound is excited by visible light to generate anthracene free radicals, which trigger the homolysis of the biimidazole compound to generate imidazole free radicals, and the imidazole free radicals activate the ethylenically unsaturated carboxylic acid and / or ethylenically unsaturated carboxylic acid ester to cause cross-linking and curing.

2. The photosensitive resin composition according to claim 1, wherein The photosensitizer has one of the following structures: The content of the photosensitizer is preferably 0.1-0.8 parts by mass, more preferably 0.2-0.5 parts by mass.

3. The photosensitive resin composition according to claim 1, wherein The alkali-soluble resin is an acrylate copolymer containing an aromatic group; Preferably, the copolymerization ratio of the comonomer having an aromatic group is 50-70% based on the total mass of the comonomers in the copolymerization process; Preferably, the alkali-soluble resin is copolymerized with (meth)acrylic acid and a copolymerization unit, and the copolymerization unit is selected from one or more of methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, hydroxyethyl (meth)acrylate, and styrene.

4. The photosensitive resin composition according to claim 1, wherein The alkali-soluble resin has a weight average molecular weight of 20,000-60,000, a resin acid value of 160-220 mg KOH / g, and a molecular weight distribution index of 1.0-3.

0.

5. The photosensitive resin composition according to claim 1, wherein The photopolymerizable monomer is a (meth)acrylate monomer; Preferably, the photopolymerizable monomer is selected from one or more of methoxy polyethylene glycol monoacrylate, ethoxy (propoxy) nonylphenol acrylate, ethoxy (propoxy) bisphenol A di(meth)acrylate, ethoxy (propoxy) di(meth)acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, ethoxy (propoxy) trimethylolpropane tri(meth)acrylate, di(trimethylolpropane) tetraacrylate, ethoxy (propoxy) pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate; Preferably, the content of the photopolymerizable monomer is 40-50 parts by mass, more preferably 45-50 parts by mass.

6. The photosensitive resin composition according to claim 1, wherein The photoinitiator is a 2,4,5-triaryl imidazole dimer; Preferably, the photoinitiator is selected from one or more of 2-(2-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole; Preferably, the content of the photoinitiator is 2-4 parts by mass, more preferably 2.5-3.5 parts by mass.

7. The photosensitive resin composition according to claim 1, wherein The photosensitive resin composition further comprises one or more additives selected from dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoaming agents, and coating aids; Preferably, the total amount of the additives is 0.5-5.0 parts by mass.

8. A photosensitive dry film, comprising from bottom to top: Support layer; a photosensitive resist layer attached to the surface of the support layer; and a protective layer attached to the surface of the photoresist layer, Wherein, the photosensitive resist layer is formed by using the photosensitive resin composition according to any one of claims 1 to 7. 9 . The photosensitive dry film according to claim 8 , wherein the support layer material is PET, and the protective layer material is PE.

10. Use of the photosensitive dry film according to claim 8 or 9 in printed circuit boards, lead frames, semiconductor packaging substrates, solar cells and photocurable inks.

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