Photosensitive Resin Composition Containing Photo-Bleachable Dienyl Anthracene Photosensitizer and Its Application

Abstract

The present invention provides a photosensitive resin composition containing a photo - bleachable diene - based anthracene photosensitizer and its application. The anthracene ring, which is the main structure of the photosensitizer, is introduced with a conjugated alkenyl functional group at the 9,10 positions. Compared with the DBA photosensitizer, the introduction of the conjugated alkenyl group expands the size of the conjugated system, elongates the maximum absorption wavelength of the molecule, improves the initiation efficiency, is particularly suitable for the photo - initiation system under 405 nm light illumination, and reduces the exposure energy. Compared with the DPHA photosensitizer, it ensures good solubility and compatibility of the formulation. In addition, the diene - based anthracene photosensitizer does not produce small - molecule fragments and can be widely applied in the fields of photocuring such as dry films, paints, coatings, inks, and molding materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of photosensitive resins, and more specifically, relates to a photosensitive resin composition containing a photo-bleachable divinyl anthracene photosensitizer and its applications. Background Art

[0002] Photosensitive resin compositions are usually coated on the surface of a polyester (PET) support film, and after drying, a polyethylene (PE) film protective layer is laminated on its surface to form a photosensitive dry film (or dry film resist). Such materials have important application values as the core materials for pattern transfer in the processes of printed circuit boards (PCBs), lead frames (LFs), semiconductor packages (ICs), solar cells, etc. Their typical process flow includes: laminating the dry film resist on the surface of a copper substrate, performing patterned exposure through a mask; using a weakly alkaline developer to remove the unexposed areas; forming the target pattern through etching or electroplating; and finally stripping the cured dry film with a stripping solution to complete the pattern transfer. During this process, the performance of the photosensitive dry film directly determines the accuracy, resolution, and production efficiency of pattern transfer, and the photoinitiator, as the core component of the photocuring reaction, has a decisive influence on the energy utilization efficiency, pattern edge clarity, and production yield of the photosensitive layer. Therefore, the design and synthesis of novel photoinitiators and the research on high-performance photosensitive resin composition formulations with these as the core have always been one of the research hotspots in this field.

[0003] Currently, small molecule anthracene derivatives represented by 9,10-dibutoxyanthracene (DBA) and 9,10-diphenylanthracene (DPHA) are widely used as photosensitizers. Generally, to obtain higher photosensitive performance and resolution, DBA and DPHA need to be used in combination with 2,4,5-triaryl imidazole dimer (HABI) (such as in patent CN101568883B); however, such a photosensitizer / photoinitiator combination system usually faces the following problems:

[0004] 1) Short-chain alkoxy anthracene derivatives with solubility advantages (similar to DBA), due to their initiation mechanism, the fragments after initiation are prone to migrate in the dry film and penetrate to the surface of the polyethylene (PE) protective film to form crystals, thus causing defects such as short circuits and open circuits in the resist pattern, or the risk of decreased photosensitivity due to the penetration of the photosensitizer from the photosensitive layer;

[0005] 2) Although DPHA has the advantage of a high photoquantum yield, due to its overly large conjugated system and high molecular rigidity, its solubility is poor, and it is prone to aggregate in the developer during the development process to generate precipitate garbage, which is easily adhered to the surface of the copper plate, causing problems such as residual copper or short circuits, affecting the product yield;

[0006] Therefore, it has become a technical problem to be urgently solved in this field to develop a new photoinitiator system with good solubility, high photo - quantum yield, low migration characteristics and excellent development compatibility, and to construct a high - performance photocurable resin composition based on this. Summary of the Invention

[0007] Therefore, the object of the present invention is to develop a photosensitizer based on 9,10 - dienyland anthracene and a photosensitive resin composition, dry film resist and photosensitive dry film suitable for it, to overcome the problem of photosensitizer migration in existing dry film products, reduce development waste, improve the photo - quantum yield of the initiator, and reduce the exposure energy.

[0008] Through a large number of literature research and experimental studies, the present invention has found the following problems and proposed innovative improvement solutions:

[0009] Anthracene compounds or anthracene derivatives, due to their unique structures, can undergo dimerization reactions under light irradiation and thus be photo - bleached. This property effectively avoids the problem of excessive energy absorption by the upper - layer photosensitizer during the exposure process, enabling the underlying photosensitive resin composition to receive light more fully, so that the photosensitive resin composition can achieve uniform curing during the exposure process and reach a better resolution. For example, Patent CN101218538B discloses 9,10 - dialkoxyanthracene - type photosensitizers, CN110446976B discloses alkoxyanthracene or phenylanthracene - type photosensitizers, and CN116300313A discloses 9,10 - diacyloxyanthracene or 9,10 - diphenoxyanthracene - type photosensitizers. The above - mentioned anthracene - type photosensitizers all have good resolution and adhesion.

[0010] However, the present invention has found that: when 9,10 - dialkoxyanthracene - type photosensitizers are exposed, the C - O bonds at the 9,10 positions will break, the anthracene ring will dimerize, and at the same time, small - molecule alkoxy fragments will be released. These small - molecule fragments will migrate from the cured photosensitive resin composition to the electroplating solution during the subsequent electroplating process, causing pollution and affecting the life of the plating solution and the electroplating effect; for 9,10 - diacyloxyanthracene - type photosensitizers (DAcOA), due to the electron - withdrawing inductive effect of the acyloxy group, the electron cloud density at the 9,10 positions of the anthracene ring increases. Therefore, the efficiency of such photosensitizers in catalyzing the curing reaction decreases, the side - wall perpendicularity of the cured photosensitive resin composition is not good, and there is a large difference in the line lengths between the top and the bottom, forming a "reverse trapezoid" problem. Moreover, the energy required for such photoinitiators during exposure increases, and the photo - bleaching efficiency decreases; for 9,10 - diarylanthracene - type photosensitizers, due to their rigid molecular structures, their solubility is greatly reduced, which has a great impact on the uniformity and consistency of the product.

[0011] Based on the above findings, the present invention provides a photosensitizer based on 9,10-dienylanthracene, as well as a compatible initiation system and a photosensitive resin composition, which can reduce the problem of photosensitizer migration existing in existing dry film products, thereby reducing development waste, improving the photosensitization quantum yield of the initiator, and reducing the exposure energy.

[0012] (I) Photosensitive Resin Composition

[0013] In a first aspect of the present invention, a photosensitive resin composition is provided. Based on 100 parts by mass of the photosensitive resin composition, it comprises 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 - 5 parts of a photoinitiator selected from bisimidazole compounds; and (D) 0.1 - 1 part of a photosensitizer, wherein the photosensitizer is a 9,10-dienylanthracene compound having the structure shown in formula (I):

[0014] (I)

[0015] Wherein, R 1 and R 2 each independently selected from hydrogen, C1 - C6 alkyl, C3 - C6 cycloalkyl, C6 - C12 aryl, C6 - C12 aryl substituted with C1 - C6 alkyl, C6 - C12 aryl substituted with C1 - C6 alkoxy; R 3 is selected from hydrogen, C1 - C6 alkyl, C3 - C6 cycloalkyl and halogen. Wherein, the photosensitive resin composition is photocured through the following photoinduced free radical polymerization reaction mechanism: the dienylanthracene compound is excited by visible light to generate anthracene radicals, which initiate the 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 undergo crosslinking curing.

[0016] Specifically, the photocuring process follows the mechanism of photoinduced free radical polymerization: the first step is that the dienylanthracene compound as the photosensitizer absorbs photons and is excited to generate anthracene radicals; the second step is that the anthracene radicals cause the homolysis of the bisimidazole compound as the photoinitiator to generate imidazole radicals; the third step, namely the curing stage: the imidazole radicals act on the ethylenically unsaturated carboxylic acid and / or ethylenically unsaturated carboxylic acid ester, open the unsaturated bonds of the activated monomers, and undergo crosslinking reactions to form a 3D network structure, and the material is rapidly cured and hardened.

[0017] The compound structures involved in the present invention follow the general representation rules in the field of organic chemistry. When a bond appears in a curved form, it represents that the compound is a mixture of E / Z isomers, and the subsequent text does not distinguish or label the E / Z configuration. For example, in the structures of compound (I), compound TM2-TM7, and TM9, there are such bonds represented by curves.

[0018] (A)Alkali-soluble resin

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

[0020] In some embodiments of the present invention, the alkali-soluble resin is copolymerized from one or more of (meth)acrylic acid, (meth)acrylic acid alkyl ester, benzyl (meth)acrylate, benzyl (meth)acrylate derivative, phenyl (meth)acrylate, styrene, and styrene derivative. In some embodiments of the present invention, the alkali-soluble resin is copolymerized from (meth)acrylic acid and a copolymerization unit selected from one or more of methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and styrene. In some specific embodiments of the present invention, the comonomers of the alkali-soluble resin include methacrylic acid, methyl methacrylate, 2-hydroxyethyl methacrylate, benzyl methacrylate, and styrene.

[0021] Furthermore, the weight-average molecular weight of the alkali-soluble resin is 20,000-60,000, the resin acid value is 160-220 mg KOH / g, and the molecular weight distribution index is 1.0-3.0. In the embodiments 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 layer to flow, and if the content exceeds 65 parts by mass, there is a tendency for the resolution to decrease.

[0022] (B)Photopolymerizable monomer

[0023] The photosensitive resin composition provided by the present invention, wherein 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 one or more of methoxypolyethylene glycol monacrylate, 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, bis(trimethylolpropane) tetraacrylate, ethoxy(propoxy)pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

[0024] In an embodiment of the present invention, the content of the photopolymerizable monomer is 35-50 parts by mass, preferably 40-50 parts by mass, 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. If the content exceeds 50 parts by mass, there is a tendency for the photosensitive resin composition to be difficult to form a thin film and for the resist layer to flow.

[0025] (C)Photoinitiator

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

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

[0028] In an 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, there is a tendency for the sensitivity and resolution of the resist to decrease. If the content exceeds 5 parts by mass, there is a tendency for an increase in developing waste.

[0029] (D)Photosensitizer

[0030] In the photosensitive resin composition provided by the present invention, among the 9,10-dienylanthracene compounds of formula (I) as the photosensitizer, conjugated unsaturated double bond functional groups are introduced at the 9th and 10th positions. Compared with the existing DBA photoinitiator, the introduction of two alkenyl groups expands the size of the conjugated system, elongates the maximum absorption wavelength of the molecule, improves the initiation efficiency (especially suitable for the photoinitiation system under 405 nm light illumination conditions), reduces the exposure energy, and at the same time ensures good solubility and formulation compatibility. In addition, compared with the existing DBA photosensitizers, the 9,10-dienylanthracene photosensitizers of the present invention do not generate small molecule fragments and can be widely used in the fields of photocuring such as dry films, paints, coatings, inks, and molding materials.

[0031] In a preferred embodiment of the present invention, the photosensitizer is selected from one or more of the following compounds TM1-TM9:

[0032]

[0033]

[0034] Among them, n-Pentyl represents n-pentyl, and n-Hendecyl represents n-undecyl.

[0035] In an embodiment of the present invention, the content of the photosensitizer is 0.1-1 part by mass, preferably 0.1-0.8 part by mass, and more preferably 0.2-0.5 part by mass. If the content is less than 0.1 part by mass, there is a tendency for the sensitivity of the resist to decrease. If the content exceeds 1 part by mass, there is a tendency for incomplete curing of the bottom layer of the resist, resulting in a "trapezoidal inverted" cross-sectional shape of the resist and poor resolution.

[0036] The 9,10-dienylanthracene photosensitizers of the present invention can be prepared by the Wittig coupling reaction commonly used in the art to construct double bonds: alkyl quaternary phosphonium salts form phosphonium ylides under strong alkaline conditions and then couple with 9,10-diformylanthracene to generate the corresponding 9,10-dienylanthracene.

[0037] Among them: 9,10-diformylanthracene (cas: 7044-91-9, available from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.). The strong basic compounds used are such as: n-butyllithium (n-BuLi), lithium diisopropylamide (LDA), lithium hexamethyldisilazide (LiHMDS), sodium hexamethyldisilazide (NaHMDS), potassium hexamethyldisilazide (KHMDS), sodium tert-butoxide (t-BuONa), etc., and preferably n-BuLi. The organic solvents used in the reaction process can be petroleum ether, tetrahydrofuran, benzene, toluene, 1,4-dioxane, etc., and preferably tetrahydrofuran. The reaction temperature can be 45-150 °C, preferably 75-90 °C. The reaction time is 2-48 h, preferably 4-8 h.

[0038] A typical reaction operation is as follows:

[0039] Under -78 °C and an inert gas protection atmosphere, in a round-bottom flask equipped with a magnetic stirrer, dissolve the phosphonium salt derivative (3 mmol) in dry tetrahydrofuran (3 mL); then, slowly add dropwise n-butyllithium (3 mmol, 2.5 M in THF). After the mixture is stirred at low temperature for 30 min, slowly add dropwise a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran). After the addition is completed, keep it at -78 °C for 1-2 hours and then slowly warm it up to room temperature, and continue the reaction until the reaction is monitored to be completed by thin-layer chromatography (TLC); wash the reaction system with saturated brine, collect the organic phase, and dry it over anhydrous sodium sulfate and then purify it by column chromatography (yield 80%-99%).

[0040] (E) Other additives

[0041] In various embodiments of the present invention, as needed, the photosensitive resin composition may further contain one or more additives selected from dyes, photo-developing agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, coating aids. Preferably, the total amount of the additives is 0.5-5.0 parts by mass.

[0042] (II) Photosensitive dry film

[0043] The second aspect of the present invention provides a photosensitive dry film, which from bottom to top includes: a support layer; a photosensitive resist layer attached to the surface of the support layer; and a protective layer attached to the surface of the photosensitive resist layer, wherein the photosensitive resist layer is formed by using the photosensitive resin composition provided in the first aspect of the present invention.

[0044] 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.

[0045] (III) Application of the photosensitive dry film

[0046] The third aspect of the present invention provides the application of the above photosensitive dry film in printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, and photocurable inks, etc.

[0047] The present invention has the following beneficial effects: The photosensitizer of the present invention has a higher photosensitivity efficiency compared with the existing 9,10-dibutoxyanthracene (DBA), can effectively reduce the energy of the exposure light source, shorten the exposure time, and improve the production efficiency; it will not produce small molecule fragments and will not produce the phenomenon of "wetting" the coated film after exposure; it has better solubility compared with the existing 9,10-diphenylanthracene (DPHA) and also shows more excellent compatibility in the formulation; it effectively reduces the defects caused by insufficient exposure or overexposure, reduces the rejection rate, and significantly improves the production yield. At the same time, on the basis of maintaining or exceeding the high resolution level of the commercially available anthracene photosensitizers, the present invention can fully meet the requirements of high-precision circuit manufacturing, make the pattern clearer and sharper, and is suitable for the production of miniaturized and high-density electronic devices. In addition to the above purposes, features and advantages, the present invention also has other potential technical advantages, providing a better solution for the development of related fields.

[0048] In summary, the photosensitive dry film provided by the present invention has excellent exposure performance and formulation compatibility, and has a higher photosensitivity than the photosensitive resin composition added with 9,10-dibutoxyanthracene and 9,10-diphenylanthracene photosensitizers, which is beneficial to improving the production efficiency of the client and meeting the requirements of high density and high precision of printed circuit boards. Description of the drawings

[0049] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings, wherein:

[0050] Figure 1 and Figure 2 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM1 prepared in Example 1 of the present invention;

[0051] Figure 3 and Figure 4 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM2 prepared in Example 2 of the present invention;

[0052] Figure 5 and Figure 6 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM3 prepared in Example 3 of the present invention;

[0053] Figure 7 and Figure 8 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM4 prepared in Example 4 of the present invention;

[0054] Figure 9 and Figure 10 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM5 prepared in Example 5 of the present invention;

[0055] Figure 11 and Figure 12 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM6 prepared in Example 6 of the present invention;

[0056] Figure 13 and Figure 14 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM7 prepared in Example 7 of the present invention;

[0057] Figure 15 and Figure 16 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM8 prepared in Example 8 of the present invention;

[0058] Figure 17 and Figure 18 are respectively the 1 1H NMR spectrum and 13 13C NMR spectrum of the photosensitizer TM9 prepared in Example 9 of the present invention;

[0059] Figure 19 are the UV-Vis absorption spectra of TM1-TM5;

[0060] Figure 20 are the UV-Vis absorption spectra of TM6-TM9;

[0061] Figure 21 is the photobleaching performance graph of TM5 under a 405 nm light source. Detailed implementation manners

[0062] The present invention will be further described in detail below in conjunction with specific embodiments. The embodiments given are only for clarifying the present invention, rather than limiting the scope of the present invention.

[0063] Example 1: Preparation of Photosensitizer TM1

[0064]

[0065] Under the atmosphere of -78 °C and inert gas protection, triphenylmethylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran in a round-bottom flask equipped with a magnetic stir bar; then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was completed, the mixture was kept at -78 °C for 1 - 2 hours and then slowly warmed to room temperature and continued to react until the reaction was monitored to be complete by thin-layer chromatography (TLC); the reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 88%).

[0066] 1 1H NMR (400 MHz, CDCl3): δ 8.39 (d, J = 10.1 Hz, 4H), 7.56 – 7.46 (m, 6H), 6.06 (dd, J = 11.5, 2.1 Hz, 2H), 5.65 (dd, J = 17.8, 2.1 Hz, 2H).

[0067] 13 13C NMR (100 MHz, CDCl3): δ 133.9, 133.5, 128.9, 126.4, 125.1, 123.1.

[0068] Example 2: Preparation of Photosensitizer TM2

[0069]

[0070] Under -78 °C and in an inert gas protection atmosphere, in a round-bottom flask equipped with a magnetic stir bar, triphenylpropylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran; then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was complete, it was kept at -78 °C for 1 - 2 hours and then slowly warmed to room temperature. The reaction was continued until the reaction was monitored to be complete by thin-layer chromatography (TLC); the reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 82%).

[0071] 1 H NMR (400 MHz, CDCl3, 300 K): δ 8.4 (d, J = 10.2 Hz, 4H), 7.5 (d, J = 10.4 Hz, 4H), 7.1 (d, J = 16.1 Hz, 2H), 6.3–5.9 (m, 2H), 2.6–2.5 (m, 4H), 1.3 (t, J = 7.4 Hz, 6H).

[0072] 13 C NMR (100 MHz, CDCl3, 300 K): δ 141.0, 133.0, 129.5, 126.6, 124.9, 124.8, 26.9, 14.0.

[0073] Example 3: Preparation of Photosensitizer TM3

[0074]

[0075] Under -78 °C and in an inert gas protection atmosphere, in a round-bottom flask equipped with a magnetic stir bar, triphenylisobutylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran; then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was complete, it was kept at -78 °C for 1 - 2 hours and then slowly warmed to room temperature. The reaction was continued until the reaction was monitored to be complete by thin-layer chromatography (TLC); the reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 90%, Z:E = 1:2).

[0076] 11H NMR (400 MHz, CDCl3): δ 8.42 – 8.35 (m, 8H), 8.32 – 8.27 (m, 4H), 7.53 – 7.48 (m, 12H), 7.11 (dd, J = 16.2, 8.5 Hz, 4H), 6.86 (d, J = 11.1 Hz, 2H), 6.14 – 5.99 (m, 6H), 2.89 – 2.76 (m, 4H), 2.12 – 2.04 (m, 2H), 1.35 (d, J = 6.8 Hz, 24H), 0.91 (d, J = 6.6 Hz, 12H). (Z / E: 1:2)

[0077] 13 13C NMR (100 MHz, CDCl3): δ 146.4, 146.3, 143.5, 133, 133, 132.1, 129.4, 129.3, 129.3, 126.8, 126.5, 126.5, 124.9, 124.8, 124.8, 123.3, 122.8, 122.7, 32.4, 32.3, 28.3, 22.7, 22.7, 22.5.

[0078] Example 4: Preparation of Photosensitizer TM4

[0079]

[0080] Under an inert gas atmosphere at -78 °C, triphenylhexylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran in a round-bottom flask equipped with a magnetic stir bar. Subsequently, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was complete, the mixture was maintained at -78 °C for 1 - 2 h and then slowly warmed to room temperature. The reaction was continued until it was monitored by thin-layer chromatography (TLC) to be completed. The reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 82%).

[0081] 11H NMR (400 MHz, CDCl3): δ 8.4 (d, J = 9.8 Hz, 4H), 7.5 (d, J = 9.9Hz, 4H), 7.1 (d, J = 16.1 Hz, 2H), 6.0 (dt, J = 16.1, 6.8 Hz, 2H), 2.5 (q, J= 7.2 Hz, 4H), 1.7 – 1.6 (m, 4H), 1.5 – 1.4 (m, 8H), 1.0 (t, J = 6.9 Hz, 6H).

[0082] 13 13C NMR (100 MHz, CDCl3): δ 139.7, 133.1, 129.5, 126.7, 125.8, 124.8,33.8, 31.8, 29.3, 22.7, 14.3.

[0083] Example 5: Preparation of Photosensitizer TM5

[0084]

[0085] Under an inert gas atmosphere at -78 °C, triphenyldodecylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran in a round-bottom flask equipped with a magnetic stir bar. Then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was complete, the reaction was maintained at -78 °C for 1 - 2 hours and then slowly warmed to room temperature. The reaction was continued until the reaction was monitored to be complete by thin-layer chromatography (TLC). The reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 88%, Z / E = 1:1.17).

[0086] 11H NMR (400 MHz, CDCl3): δ 8.37 (d, J = 16.24 Hz, 3.42H), 8.23 (d, J = 15.12 Hz, 4.00H), 7.47 (d, J = 7.80 Hz, 7.42H), 7.12 (dd, J = 16.08, 8.72 Hz, 1.71H), 7.00 (t, J = 10.26 Hz, 2.00H), 6.33 – 6.21 (m, 2.00H), 6.08 – 5.96 (m, 1.70H), 2.58 – 2.47 (m, 3.44H), 1.86 – 1.72 (m, 4.00H), 1.75 – 1.62 (m, 3.42H), 1.58 – 1.47 (m, 4.00H), 1.38–1.08 (m, 59.43H), 0.90 (t, J = 7.06 Hz, 11.13H). (Z / E: 1:1.17)

[0087] 13 13C NMR (100 MHz, CDCl3): δ 139.7, 139.7, 136.8, 133.3, 133.1, 132.1, 131.9, 129.5, 129.4, 129.3, 129.2, 126.9, 126.9, 126.7, 126.7, 125.8, 125.8, 125.7, 125.7, 124.9, 124.9, 33.9, 33.9, 32.1, 32.1, 29.9, 29.9, 29.7, 29.7, 29.7, 29.5, 29.3, 22.9, 22.9, 14.3.

[0088] Example 6: Preparation of Photosensitizer TM6

[0089]

[0090] Under the atmosphere of -78 °C and inert gas protection, (cyclopropylmethyl)triphenylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran in a round-bottom flask equipped with a magnetic stir bar. Then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was complete, the reaction was continued at -78 °C for 1 - 2 hours and then slowly warmed to room temperature. The reaction was continued until the reaction was monitored by thin-layer chromatography (TLC) to be completed. The reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and then purified by column chromatography (yield 92%, Z / E = 1:2).

[0091] 1 H NMR (400 MHz, CDCl3): δ 8.46 – 8.33 (m, 12H), 7.55 – 7.43 (m, 12H),7.27 – 7.17 (m, 4H), 6.96 (t, J = 10.6 Hz, 2H), 5.67 – 5.47 (m, 6H), 1.98 –1.83 (m, 4H), 1.11 – 1.02 (m, 2H), 0.96 (d, J = 7.9 Hz, 8H), 0.70 – 0.57 (m,12H), 0.53 – 0.48 (m, 4H).(Z / E: 1:2)

[0092] 13 C NMR (100 MHz, CDCl3): δ 143.0, 142.9, 140.2, 132.9, 132.6, 131.7,129.5, 129.4, 129.4, 129.3, 127.1, 127.1, 126.6, 126.5, 124.9, 124.8, 124.8,123.27, 123.1, 15.0, 12.0, 7.1, 7.0.

[0093] Example 7: Preparation of Photosensitizer TM7

[0094]

[0095] Under an atmosphere of -78 °C and inert gas protection, (cyclopropylmethyl)triphenylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran in a round-bottom flask equipped with a magnetic stir bar. Then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was complete, the reaction was maintained at -78 °C for 1 - 2 hours and then slowly warmed to room temperature. The reaction was continued until monitored by thin-layer chromatography (TLC) to be complete. The reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 92%, Z / E = 1:2).

[0096] 1 1H NMR (400 MHz, CDCl3, 300 K): δ 8.1 (d, J = 10.1 Hz, 4H), 7.5 – 7.2(m, 14H), 7.1 (d, J = 16.0 Hz, 2H), 6.0 (dt, J = 16.1, 6.8 Hz, 2H), 3.0 (t, J= 7.2 Hz, 2H), 2.9 (q, J = 7.1 Hz, 2H).

[0097] 13 13C NMR (100 MHz, CDCl3, 300 K): δ 141.8, 138.2, 132.8, 129.4, 128.9,128.6, 126.9, 126.6, 126.1, 124.8, 35.8, 35.4.

[0098] Example 8: Preparation of Photosensitizer TM8

[0099]

[0100] Under -78 °C and in an inert gas protection atmosphere, 4-ethoxybenzyltriphenylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran in a round-bottom flask equipped with a magnetic stir bar; then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was complete, it was kept at -78 °C for 1 - 2 hours and then slowly warmed to room temperature, and the reaction was continued until the reaction was monitored by thin-layer chromatography (TLC) to be completed; the reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and then purified by column chromatography (yield 93%).

[0101] 1 1H NMR (400 MHz, CDCl3, 300 K): δ 8.41 (d, J = 10.1 Hz, 4H), 7.79 (d, J = 16.4 Hz, 2H), 7.62 (d, J = 8.7 Hz, 4H), 7.46 (d, J = 10.1 Hz, 4H), 6.99 (d, J = 8.7 Hz, 4H), 6.87 (d, J = 16.5 Hz, 2H), 4.12 (q, J = 7.0 Hz, 4H), 1.47 (t, J = 7.0 Hz, 6H).

[0102] 13 13C NMR (100 MHz, CDCl3, 300 K): δ 159.0, 136.9, 132.8, 130.1, 129.7, 127.8, 126.6, 125.1, 122.8, 114.8, 63.6, 14.9.

[0103] Example 9: Preparation of Photosensitizer TM9

[0104]

[0105] Under the protection of inert gas atmosphere at -78 °C, [3-(benzyloxy)propyl]triphenylphosphonium bromide (3 mmol) was dissolved in 3 mL of dry tetrahydrofuran in a round-bottom flask equipped with a magnetic stir bar; then, n-butyllithium (3 mmol, 2.5 M in THF) was slowly added dropwise. After the mixture was stirred at low temperature for 30 min, a tetrahydrofuran solution of 9,10-diformylanthracene (1 mmol dissolved in 5 mL of dry tetrahydrofuran) was slowly added dropwise. After the addition was completed, the mixture was kept at -78 °C for 1 - 2 h and then slowly warmed to room temperature, and the reaction was continued until the reaction was monitored by thin-layer chromatography (TLC) to be completed; the reaction system was washed with saturated brine, the organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 89%, Z / E = 1:6).

[0106] 1 H NMR (400 MHz, CDCl3, 300 K): δ 8.32 (d, J = 10.1 Hz, 4H), 7.44 – 7.28 (m, 14H), 7.17 (d, J = 16.2 Hz, 2H), 6.05 – 5.96 (m, 2H), 4.62 (s, 4H), 3.77 (t, J = 6.5 Hz, 4H), 2.84 – 2.78 (m, 4H).

[0107] 13 C NMR (100 MHz, CDCl3, 300 K): δ 138.6, 135.7, 132.8, 129.4, 128.5, 127.9, 127.7, 127.6, 126.6, 124.9, 73.2, 70.0, 34.2.

[0108] Example 10: Maximum Absorption Wavelength, Photo-Bleaching Property and Solubility

[0109] I. Ultraviolet-visible spectroscopy determination:

[0110] Equipment: Agilent, UV-1900i, configured with a toluene solution of the sample (4×10 -5 mol / L). Determine the maximum absorption wavelength in the scanning mode, read the absorbance (A), and take the average value after repeating 3 times; observe the absorption spectrum diagram to determine the position of the characteristic absorption peak (λ max ); draw the ultraviolet-visible absorption spectrum diagram, and calculate the molar extinction coefficient ε according to the Lambert-Beer law.

[0111] Table 1

[0112]

[0113] II. Photobleaching Experiment:

[0114] The remaining part of the solution prepared according to the UV-Vis spectrum of TM5 was exposed under a handheld 405 nm light source, and the UV-Vis absorption spectrum was measured at fixed intervals (marked in the figure). The degree of decrease in absorbance A at the maximum absorption wavelength was observed. The results are as Figure 21 shown.

[0115] As Figure 21 can be seen, such compounds have very good photobleaching properties and can be completely photobleached within 90 minutes.

[0116] III. Solubility Test

[0117] Taking acetone and toluene as solvent representatives, the solubility of photosensitizers TM1-TM4, DBA, and DPHA in Examples 1-4 in the solvents was tested. The solute was added to the solvent at a ratio of 0.1 g solute / 1 g solvent (10% w / w), and the dissolution situation was recorded according to the following classification criteria:

[0118] A (rapid dissolution): A clear, transparent, and homogeneous solution can be formed within 1 minute at room temperature under stirring conditions;

[0119] B (slow dissolution): A clear, transparent, and homogeneous solution can be formed after more than 5 minutes at room temperature under stirring conditions; or it cannot be completely dissolved at room temperature, but a clear, transparent, and homogeneous solution can be formed when heated to 50-60 °C, and there is no obvious turbidity after returning to room temperature;

[0120] C (partial dissolution): It cannot be completely dissolved after more than 5 minutes at room temperature under stirring conditions; or it can be completely dissolved when heated to 50-60 °C, but it becomes significantly turbid after returning to room temperature.

[0121] The test results are shown in Table 2.

[0122] Table 2

[0123]

[0124] Example 11: Preparation of Photosensitive Resin Composition

[0125] According to the formula shown in Table 3, each component was mixed evenly to prepare a photosensitive resin composition.

[0126] Table 3

[0127]

[0128] Note: The weights in Table 3 are calculated based on the solid content and do not include the solvent components.

[0129] The component descriptions of each component code in Table 3 are as follows:

[0130] Alkali-soluble resin (A): Acrylate copolymer, solution polymerization method, polymerized according to the mass ratio of methacrylic acid / butyl methacrylate / benzyl methacrylate = 25 / 10 / 65; the solvent is acetone, the solid content is 46%, the weight-average molecular weight is 40,000, the dispersity is 2.1, and the acid value is 163 mgKOH / g. (Hunan Chuyuan New Materials Co., Ltd.)

[0131] The photo-polymerizable monomer (B) consists of the following components (purchased from Sartomer Guangzhou Chemical Co., Ltd.): 5 g of methoxypolyethylene glycol (350) monomethacrylate, 20 g of 10-(ethoxy)bisphenol A dimethacrylate, 5 g of 6-(propoxy)bisphenol A dimethacrylate, 10 g of 3-(ethoxy)trimethylolpropane triacrylate, 4 g of bis(trimethylolpropane) tetraacrylate

[0132] Photoinitiator (C): 2,2′-bis(o-chlorophenyl)-4,4′,5,5′-tetraphenyl-imidazole (BCIM)

[0133] The additive (E) consists of the following components (purchased from Energy Chemical): 0.5 g of leuco crystal violet, 0.05 g of malachite green, 0.8 g of p-toluenesulfonamide, 0.03 g of 2,6-di-tert-butyl-4-methylphenol

[0134] The solvent consists of the following components: 8% acetone, 10% toluene, 5% methanol

[0135] Example 12: Preparation of Photosensitive Dry Film

[0136] Prepare a photosensitive dry film from the photosensitive resin composition listed in Table 3 of Example 11, including the following steps:

[0137] Use experimental equipment (model: AB4220, TQC, Netherlands) to coat the photosensitive composition slurry prepared according to Table 3 on a 15-μm-thick polyethylene terephthalate (PET) support film; bake at 80 °C for 10 min to remove the solvent, and control the thickness of the photosensitive layer to 30 μm after baking. Then cover it with a polyethylene film (PE) for protection to obtain a photosensitive dry film.

[0138] Example 13: Preparation of Substrate with Resist Pattern

[0139] Use the photosensitive compositions of Samples 1-4 of the examples and Comparative Samples 1-3 of the present invention shown in Table 3 to prepare substrates with resist patterns. The procedures are as follows:

[0140] (1) Photosensitive layer formation process: Form a photosensitive layer on the substrate using the photosensitive composition;

[0141] (2) Exposure process: irradiate a part of the above photosensitive layer with actinic light to photocure the above area to form a cured area;

[0142] (3) Development process: remove the part of the above photosensitive layer other than the cured area from the substrate to form a resist pattern on the substrate.

[0143] Hereinafter, the operating conditions of each process will be specifically described.

[0144] Photosensitive layer formation process: Use a copper-clad laminate laminated with a 35-μm-thick rolled 1.2-mm-thick copper foil. After surface conditioning and preheating to 80 °C, while peeling off the PE protective film of the photosensitive dry film obtained from each example or comparative example, laminate the above photosensitive resin composition layer on the copper-clad laminate using a hot roll laminator (Zhisheng Technology Co., Ltd., CSL-M25E) under the conditions of a roll temperature of 110 °C, an air pressure of 0.35 MPa, and a lamination speed of 1.5 m / min to obtain a test substrate.

[0145] Exposure process: Use a direct drawing exposure machine (Xinqi Micro, main wavelength 405 nm) for exposure. Use a Stouffer 41-step exposure scale for sensitivity testing, and control the exposure grid number within 14 - 18 grids.

[0146] Development process: After exposure, peel off the PET support film. Use an alkali developer (manufactured by Guangzhou Julong Printed Circuit Board Equipment Co., Ltd., a developer for dry film), spray a 1 wt% 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, wash with pure water for 1.5 times the development time, perform water removal treatment using an air knife, and then perform warm air drying to obtain a substrate with a cured film for evaluation. The shortest time required for the complete dissolution of the unexposed part of the photosensitive resin layer is defined as the minimum development time.

[0147] Evaluation Items

[0148] 1. Sensitivity evaluation

[0149] On the test substrate after the above laminating, place a Stouffer 41-step exposure scale for sensitivity testing. After the exposure process, let the test substrate stand for 20 min or more, then peel off the PET film layer, spray a 1.0 wt% sodium carbonate aqueous solution at 30 °C to remove the unexposed resist layer, and the development time is 2.0 times the minimum development time. After the above operations, a cured film obtained by curing the photosensitive resin composition is formed on the substrate surface. The exposure energy (mJ / cm when the remaining number of segments of the step exposure scale obtained through the cured film is 16 segments 2), the sensitivity of the photosensitive resin composition was evaluated. The smaller this value is, the better the sensitivity.

[0150] 2. Adhesion evaluation

[0151] On the above-mentioned test substrate after laminating, using photomask data with a line width / space width of n:400 (unit: μm) wiring pattern, exposure was performed with an energy that makes the remaining step number after developing the Stouffer 41-step step wedge reach 16. After the developing process, the resist pattern was observed using an optical microscope, and the value of the minimum line width where a complete cured resist line was formed was used as the adhesion value to evaluate the adhesion (μm). The smaller this value is, the better the adhesion. In addition, to solve the problem of poor adhesion in some cases, the industry often uses the process of secondary lamination, and this was also tested in this example. In the adhesion column, the data in parentheses are the adhesion data after secondary lamination.

[0152] 3. Resolution evaluation

[0153] On the above-mentioned test substrate after laminating, using photomask data with a line width / space width of n:n (unit: μm) wiring pattern, exposure was performed with an energy that makes the remaining step number after developing the Stouffer 41-step step wedge reach 16. After the developing process, the resist pattern was observed using an optical microscope, and the value of the minimum line width where a complete cured resist line was formed was used as the adhesion value to evaluate the adhesion (μm). The smaller this value is, the better the resolution.

[0154] 4. Resist shape evaluation

[0155] In the resist pattern used for the above resolution evaluation, the best resolution part was observed with a SU1000 type scanning electron microscope (manufactured by Hitachi). Evaluation was carried out according to the following evaluation criteria:

[0156] ■: The difference between the top and bottom widths at the front end cross-section of the resist is less than or equal to 0.8 μm, and basically no inverted trapezoid can be observed;

[0157] ○: The difference between the top and bottom widths at the front end cross-section of the resist is greater than 0.8 μm and less than 1.2 μm, and the cross-section is slightly trapezoidal;

[0158] ×: The difference between the top and bottom widths at the front end cross-section of the resist is greater than or equal to 1.2 μm, and the cross-section is significantly trapezoidal.

[0159] The test results of evaluation items 1 - 4 are summarized in Table 4 below.

[0160] Table 4

[0161]

[0162] The results in Table 4 show that the samples of the present invention exhibit obvious advantages in terms of exposure energy; although the adhesion performance is not good, it can be improved by the secondary lamination process; however, in terms of resolution and resist shape, it has obvious advantages, solving the problem that the resist formed by the curing of DBA and DPHA photosensitizers is prone to form an inverted trapezoid; indicating that the photosensitizer of the present invention has wide applicability.

[0163] The above content is only the preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can make various modifications and changes within the spirit and principle of the present invention, and any changes, equivalent substitutions or improvements within this scope shall be regarded as 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 a diene anthracene compound having a structure shown in formula (I): （I） Among them, R 1 and R 2 Each is 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; R 3 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl and halogen, The photosensitive resin composition is photocured by the following photoinduced free radical polymerization reaction mechanism: the dienyl anthracene compound is excited by visible light to generate anthracene free radicals, which trigger the homolysis of the bisimidazole 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 is selected from one or more of the following compounds TM1-TM9: Among them, n-Pentyl represents n-pentyl, and n-Hendecyl represents n-undecyl.

3. The photosensitive resin composition according to claim 1, wherein The content of the photosensitizer is 0.1-0.8 parts by weight.

4. The photosensitive resin composition according to claim 1, wherein The alkali-soluble resin is an acrylate copolymer containing an aromatic group, wherein the copolymerization ratio of the copolymer having the aromatic group is 50-70% based on the total mass of the copolymerized monomers during the copolymerization process.

5. The photosensitive resin composition according to claim 1, wherein 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.

6. The photosensitive resin composition according to claim 1, wherein 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.

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; Wherein, the total amount of the additive is 0.5-5.0 parts by weight.

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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