Photosensitive Resin Composition Containing Alkynyl Anthracene Photosensitizer and Its Application

Abstract

The present invention provides a photosensitive resin composition containing an alkynyl anthracene photosensitizer and its applications. The conjugated alkynyl functional groups are introduced at the 9- and / or 10-positions of the anthracene ring, which is the structural main body of the photosensitizer. Compared with the existing DBA photosensitizers, the introduction of alkynyl groups expands the size of the conjugated system, elongates the maximum absorption wavelength of the molecule, improves the initiation efficiency, is particularly suitable for the photoinitiation system under 405 nm light illumination, reduces the exposure energy, and at the same time ensures good solubility and compatibility of the formulation; in addition, compared with the existing DBA photosensitizers, it does not produce small molecule fragments, does not migrate to the polyethylene film, and does not cause fragment precipitation to contaminate the electroplating solution during the electroplating process after exposure and development, thereby avoiding adverse phenomena such as short circuits and open circuits of the resist pattern and significantly improving the yield of the product; it can be widely applied to the photocuring fields 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 particularly, relates to a photosensitive resin composition containing an alkynyl 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 in the fields of printed circuit boards (PCBs), lead frames (LFs), semiconductor packages (ICs), solar cells, etc., as the core materials for pattern transfer in etching or electroplating processes. Its 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. As the core component of the photocuring reaction, the performance of the photoinitiator has a decisive impact on the energy utilization efficiency of the photosensitive layer, the clarity of the pattern edges, and the production yield. Therefore, the design and synthesis of novel photoinitiators and the research on high-performance photosensitive resin composition formulations centered around them have always been one of the research hotspots in this field.

[0003] Currently, small molecule anthracene derivatives represented by 9,10-dibutoxyl anthracene (9,10-DBA for short) are widely used as photoinitiators. Generally, 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 the exposure energy is limited, resulting in an extended exposure time and a decreased production efficiency. Although such problems can be solved by conventional means such as increasing the addition amount, more problems will arise:

[0004] 1) The initiation mechanism of short-chain alkoxy anthracene derivatives causes the fragments after initiation to easily migrate in the dry film and penetrate to the surface of the polyethylene (PE) protective film to form crystals, resulting in 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) It is easy to aggregate in the developer during the development process to generate precipitate waste, which is easy to adhere to the surface of the copper plate, causing problems such as residual copper or short circuits, affecting the product yield.

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

[0007] Therefore, the object of the present invention is to develop a photoinitiator based on 9 - and / or 10 - alkynylanthracene and a photosensitive resin composition, dry film resist, and photosensitive dry film suitable therefor, to overcome the problem of photosensitizer migration in existing dry film products, while reducing development waste, improving the photo - quantum yield of the initiator, and reducing 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: 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 - based photosensitizers, CN110446976B discloses alkoxyanthracene or phenylanthracene - based photosensitizers, and CN116300313A discloses 9,10 - diacyloxyanthracene or 9,10 - diphenoxyanthracene - based photosensitizers. The above - mentioned anthracene - based photosensitizers all have good resolution and adhesion.

[0009] However, the present invention has found that: when 9,10 - dialkoxyanthracene - based 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; due to the electron - withdrawing inductive effect of the acyloxy group in 9,10 - diacyloxyanthracene - based photosensitizers, the electron cloud density at the 9,10 positions of the anthracene ring increases, so the efficiency of such photosensitizers in catalyzing the curing reaction decreases, the side - wall perpendicularity of the cured photosensitive resin composition is poor, 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 - based 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.

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

[0011] (1) Photosensitive Resin Composition

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

[0013]

[0014] wherein R1 and R2 are 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; R3 is selected from hydrogen, C1 - C6 alkyl, C3 - C6 cycloalkyl, and halogen; X is halogen, and wherein the photosensitive resin composition is photocured through the following photoinduced free radical polymerization reaction mechanism: the alkynyl anthracene 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 the ethylenically unsaturated carboxylic acid ester to undergo crosslinking curing.

[0015] Specifically, the photocuring process follows the mechanism of photoinduced free radical polymerization: the first step is that the alkynyl anthracene compound as the photosensitizer is excited to generate anthracene radicals after absorbing photons; 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, i.e., the curing stage: the imidazole radicals act on the ethylenically unsaturated carboxylic acid and / or the ethylenically unsaturated carboxylic acid ester, open the unsaturated bonds of the activated monomers, and undergo a crosslinking reaction to form a 3D network structure, and the material is rapidly cured and hardened.

[0016] In the present invention, the halogen is preferably chlorine or bromine.

[0017] (A) Alkali-Soluble Resin

[0018] In 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 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%.

[0019] In some embodiments of the present invention, the alkali-soluble resin is obtained by copolymerizing one or more of (meth)acrylic acid, (meth)acrylic acid alkyl ester, (meth)acrylic acid benzyl ester, (meth)acrylic acid benzyl ester derivative, (meth)acrylic acid phenyl ester, styrene, and styrene derivative. In some embodiments of the present invention, the alkali-soluble resin is copolymerized from (meth)acrylic acid and copolymerization units 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.

[0020] 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.

[0021] (B)Photopolymerizable monomer

[0022] According to 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 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(trimetylolpropane) tetraacrylate, ethoxy(propoxy)pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

[0023] In the embodiments 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, and 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.

[0024] (C)Photoinitiator

[0025] According to 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 a 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 illumination conditions.

[0026] 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, 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0027] 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, and if the content exceeds 5 parts by mass, there is a tendency for an increase in developing waste.

[0028] (D)Photosensitizer

[0029] According to the photosensitive resin composition provided by the present invention, wherein in the alkynyl anthracene compound with the structure of formula (I) as the photosensitizer, a conjugated alkynyl functional group is introduced at the 9 and / or 10 positions. Compared with the existing DBA photoinitiator, the introduction of the alkynyl group expands the size of the conjugated system, elongates the maximum absorption wavelength of the molecule, improves the initiation efficiency (especially suitable for a photoinitiating system under 405 nm light illumination conditions), reduces the exposure energy, and at the same time ensures good solubility and compatibility of the formulation (chain-like alkynyl group). In addition, compared with the existing DBA photoinitiators, no small molecule fragments are generated, and it can be widely used in photocuring fields such as dry film, paint, coating, ink, and molding materials.

[0030] 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.

[0031] In some specific embodiments of the present invention, the photosensitizer may have one of the following structures:

[0032] 。

[0033] 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, the sensitivity of the resist tends 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.

[0034] The alkynylanthracene photosensitizer of the present invention can be prepared by a conventional synthesis method in the art. For example, the alkynylanthracene compound can be formed by the Sonogashira coupling reaction of 9,10-dibromoanthracene and a terminal alkyne compound under the co-catalysis of Pd(II) and Cu(I). The reaction general formula is shown as follows:

[0035]

[0036] 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.

[0037] 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%.

[0038] (E) Other additives

[0039] In an embodiment of the present invention, if necessary, the photosensitive resin composition may further contain one or more additives selected from dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, and coating aids. Preferably, the total amount of the additives is 0.5 - 5.0 parts by mass.

[0040] (II) Photosensitive dry film

[0041] The second aspect of the present invention provides a photosensitive dry film, which includes, from bottom to top: 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 using the photosensitive resin composition provided by the first aspect of the present invention.

[0042] In some preferred embodiments of the present invention, the photosensitive dry film includes, 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.

[0043] (III) Applications of the photosensitive dry film

[0044] The third aspect of the present invention provides the applications of the above photosensitive dry film in printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, and photocurable inks, etc.

[0045] The present invention has the following beneficial effects: Compared with the existing 9,10 - dibutoxyanthracene (DBA), the photosensitizer of the present invention can reduce the exposure energy, improve the photosensitivity efficiency, and utilize the energy of the exposure light source more efficiently, thereby shortening the exposure time and improving the production efficiency. At the same time, on the basis of maintaining or exceeding the high - resolution level of DBA, the present invention meets the requirements of high - precision circuit manufacturing, makes the pattern clearer and sharper, and is suitable for the production of miniaturized and high - density electronic devices. In addition, by optimizing the photosensitive performance, defects caused by insufficient exposure or over - exposure are effectively reduced, the scrap rate is decreased, 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, providing 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 photosensitivity than the photosensitive resin composition added with 9,10 - dibutoxyanthracene photosensitizer, 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

[0046] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings, where:

[0047] Figure 1 is the 1 1H NMR spectrum of the photosensitizer D1 prepared in Example 1 of the present invention;

[0048] Figure 2 is the 13 13C NMR spectrum of the photosensitizer D1 prepared in Example 1 of the present invention;

[0049] Figure 3 is the 1 1H NMR spectrum of the photosensitizer D2 prepared in Example 2 of the present invention;

[0050] Figure 4 is the 13 13C NMR spectrum of the photosensitizer D2 prepared in Example 2 of the present invention;

[0051] Figure 5 is the 1 1H NMR spectrum of the photosensitizer D3 prepared in Example 3 of the present invention;

[0052] Figure 6 is the 13 13C NMR spectrum of the photosensitizer D3 prepared in Example 3 of the present invention;

[0053] Figure 7 is the 1 1H NMR spectrum of the photosensitizer D4 prepared in Example 4 of the present invention;

[0054] Figure 8 is the 13 13C NMR spectrum of the photosensitizer D4 prepared in Example 4 of the present invention;

[0055] Figure 9 is the ultraviolet absorption spectrum of the photosensitizers D1 - D4 prepared in Examples 1 - 4 of the present invention. Detailed Embodiments

[0056] The present invention will be further described in detail below in conjunction with the detailed embodiments. The examples given are only for clarifying the present invention, rather than limiting the scope of the present invention.

[0057] Example 1

[0058] Preparation of 9,10 - dioctynylanthracene (photosensitizer D1)

[0059] Under a nitrogen atmosphere, in a round-bottom flask equipped with a magnetic stir bar, the materials 9,10-dibromoanthracene (0.5 mmol) and octyne (1.5 mmol) were added in a molar ratio of 1:3. Subsequently, Pd(PPh3)2Cl2 (5 mol%) and CuI (20 mol%) were added successively, along with triethylamine (2.0 equivalents). Finally, 4 ml of dry toluene was added, and the reaction was carried out for a certain time. After the reaction was monitored by TLC and completed, the reaction system was washed successively with saturated ammonium chloride and saturated brine. 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-dioctynylanthracene is as follows, where n C6H 13 represents n-hexyl:

[0060]

[0061] 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).

[0062] 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.

[0063] Example 2

[0064] Preparation of 9,10-bis(phenylethynyl)anthracene (photosensitizer D2)

[0065] Under a nitrogen atmosphere, into a round-bottom flask equipped with a magnetic stir bar, the materials 9,10-dibromoanthracene (0.5 mmol) and phenylacetylene were added in a molar ratio of 1:3. Subsequently, Pd(PPh3)2Cl2 (5 mol%) and CuI (20 mol%) were added successively, along with triethylamine (2.0 equivalents). Finally, 4 ml of dry toluene was added, and the reaction was carried out for a certain time. After monitoring the reaction completion by TLC, the reaction system was washed successively with saturated ammonium chloride and saturated brine. 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:

[0066]

[0067] 1 1H 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).

[0068] 13 13C 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.

[0069] Example 3

[0070] Preparation of 9-(4-methoxyphenylethynyl)-10-bromoanthracene (photosensitizer D3)

[0071] Under a nitrogen atmosphere, into a round-bottom flask equipped with a magnetic stir bar, the materials 9,10-dibromoanthracene (0.5 mmol) and 4-methoxyphenylethynyl were added in a molar ratio of 1:3. Subsequently, Pd(PPh3)2Cl2 (5 mol%) and CuI (20 mol%) were added successively, along with triethylamine (2.0 equivalents). Finally, 4 ml of dry toluene was added, and the reaction was carried out for a certain time. After monitoring the reaction completion by TLC, the reaction system was washed successively with saturated ammonium chloride and saturated brine. The organic phase was collected, dried over anhydrous sodium sulfate, and purified by column chromatography (yield 75%). The structural formula of the product 9-(4-methoxyphenylethynyl)-10-bromoanthracene (photosensitizer D3) is as follows:

[0072]

[0073] 11H NMR (400 MHz, CDCl3, 300 K): δ 8.67 (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).

[0074] 13 13C 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.

[0075] Example 4

[0076] Preparation of 9,10-Bis(4-methoxystyryl)anthracene (Photosensitizer D4)

[0077] Under a nitrogen atmosphere, 9-(4-methoxystyryl)-10-bromoanthracene (0.5 mmol) and 4-methoxystyrene were added to a round-bottom flask equipped with a magnetic stir bar in a molar ratio of 1:2. Subsequently, Pd(PPh3)2Cl2 (5 mol%), CuI (20 mol%), and triethylamine (2.0 equiv) were added in sequence, and finally 4 ml of dry toluene was added. The reaction was carried out for a certain time. After monitoring the reaction completion by TLC, the reaction system was washed successively with saturated ammonium chloride and saturated brine, 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-bis(4-methoxystyryl)anthracene (photosensitizer D4) is as follows:

[0078]

[0079] 1 1H 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).

[0080] 1313C 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.

[0081] Example 5

[0082] Preparation of Photosensitive Resin Composition

[0083] According to the formulation shown in Table 1, each component was mixed evenly to prepare a photosensitive resin composition. In order to facilitate film coating, the solvent acetone could be added to adjust to an appropriate viscosity. Here, blank indicates not added.

[0084] Table 1

[0085] Note: The weights in Table 1 are calculated based on the solid content and do not include the solvent component.

[0086] The component descriptions of each component code in Table 1 are as follows:

[0087] Alkali-soluble resin (A)

[0088] A1: 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 40000, the dispersity is 2.1, and the acid value is 163 mgKOH / g. (Hunan Chuyuan New Materials Co., Ltd.)

[0089] A2: Acrylate copolymer, solution polymerization method, polymerized according to the mass ratio of methacrylic acid / ethyl methacrylate / styrene = 30 / 20 / 50; the solvent is acetone, the solid content is 47%, the weight average molecular weight is 55000, the dispersity is 2.3, and the acid value is 195 mgKOH / g. (Hunan Chuyuan New Materials Co., Ltd.)

[0090] A3: Acrylate copolymer, solution polymerization method, polymerized according to the mass ratio of methacrylic acid / ethyl methacrylate / benzyl methacrylate / styrene = 32 / 9 / 34 / 25; the solvent is acetone, the solid content is 47%, the weight average molecular weight is 25000, the dispersity is 1.9, and the acid value is 208 mgKOH / g. (Hunan Chuyuan New Materials Co., Ltd.)

[0091] Photopolymerizable monomer (B)

[0092] B1: Methoxypolyethylene glycol (350) monoacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0093] B2: 4-(Ethoxy)nonylphenol acrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0094] B3: 10-(Ethoxy)bisphenol A dimethacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0095] B4: 6-(Propoxy)bisphenol A dimethacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0096] B5: Polyethylene glycol (400) diacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0097] B6: 3-(Ethoxy)trimethylolpropane triacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0098] B7: Di(trimethylolpropane) tetraacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0099] B8: 4-(Ethoxy)pentaerythritol tetraacrylate (Sartomer Guangzhou Chemical Co., Ltd.)

[0100] Photoinitiator (C)

[0101] C: 2,2'-Bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2-dimidazole (BCIM)

[0102] Photosensitizer (D)

[0103] D1: 9,10-Dioctynylanthracene

[0104] D2: 9,10-Bis(phenylethynyl)anthracene

[0105] D3: 9-(4-Methoxyphenylethynyl)-10-bromoanthracene

[0106] D4: 9,10-Bis(4-methoxyphenylethynyl)anthracene

[0107] TM-1: 9,10-Dibutoxyanthracene

[0108] Additive (E)

[0109] E1: Leuco crystal violet (Energy Chemical)

[0110] E2: Malachite green (Energy Chemical)

[0111] E3: p-Toluenesulfonamide (Energy Chemical)

[0112] E4: 2,6-Di-tert-butyl-4-methylphenol (Energy Chemical)

[0113] Example 6

[0114] Preparation of photosensitive dry film

[0115] The photosensitive resin composition listed in Table 1 of Example 5 was used to prepare a photosensitive dry film, including the following steps: The prepared photosensitive composition slurry was coated on a 15-μm-thick polyethylene terephthalate (PET) support film using an experimental device (model: AB4220, TQC, Netherlands); baked at 80 °C for 10 min to remove the solvent, and after baking, the thickness of the photosensitive layer was controlled to be 30 μm, and then a polyethylene film (PE) was covered for protection to obtain the photosensitive dry film.

[0116] Example 7

[0117] Preparation of a substrate with a resist pattern

[0118] Substrates with resist patterns were prepared using the photosensitive compositions of Samples 1-7 of the present invention and Comparative Samples 1-2 as shown in Table 1, and the procedures were as follows:

[0119] (1) Photosensitive layer formation step: A photosensitive layer was formed on the substrate using the photosensitive composition.

[0120] (2) Exposure step: A part of the above photosensitive layer was irradiated with actinic rays to photocure the above area to form a cured area.

[0121] (3) Development step: The part of the above photosensitive layer other than the cured area was removed from the substrate to form a resist pattern on the substrate.

[0122] Hereinafter, the operating conditions of each step will be specifically described.

[0123] Photosensitive layer formation step: A copper-clad laminate laminated with a 35-μm-thick rolled 1.2-mm-thick copper foil was surface-treated and preheated to 80 °C, and while peeling off the PE protective film of the photosensitive dry film obtained from each example or comparative example, the above photosensitive resin composition layer was laminated on the copper-clad laminate using a hot roll laminator (Zisheng 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.

[0124] Exposure step: Using a direct drawing exposure machine (Xinqi Micro, main wavelength 405 nm), exposure was performed, and a Stouffer 41-step exposure scale was used for sensitivity testing, and the exposure grid was controlled to be 14-18 grids.

[0125] Developing process: After exposure, the PET support film was peeled off, and a soda developer (manufactured by Guangzhou Julong Printed Circuit Board Equipment Co., Ltd., a developer for dry film) was used to spray a 1 wt% Na2CO3 aqueous solution at 30 °C for a time twice that of the minimum developing time to dissolve and remove the unexposed part of the photosensitive resin layer. After development, it was washed with pure water for 1.5 times the developing time, and after water removal treatment with an air knife, warm air drying was carried out to obtain a substrate with a cured film for evaluation. The shortest time required for the complete dissolution of the photosensitive resin layer in the unexposed part was defined as the minimum developing time.

[0126] Evaluation items

[0127] 1. Sensitivity evaluation

[0128] On the above-mentioned test substrate after laminating, a Stouffer 41-step exposure ruler was placed for sensitivity testing. After the exposure process, the test substrate was allowed to stand for more than 20 min, and then the PET film layer was peeled off. A 1.0 wt% sodium carbonate aqueous solution was sprayed at 30 °C to remove the unexposed resist layer, and the developing time was 2.0 times that of the minimum developing time. After the above operations, a cured film obtained by curing the photosensitive resin composition was formed on the substrate surface. The exposure energy (mJ / cm 2 ) when the remaining number of steps of the step exposure ruler obtained through the cured film was 16 was used to evaluate the sensitivity of the photosensitive resin composition. The smaller this value, the better the sensitivity.

[0129] 2. Adhesion evaluation

[0130] On the above-mentioned test substrate after laminating, a secondary lamination treatment was first carried out (temperature: 120 ± 5 °C, pressure: 0.3 ± 0.05 MPa, duration: 30 ± 5 s) to enhance the bonding force between the resist and the substrate and avoid distortion of the test results due to insufficient bonding force. Using the photomask data with a line width / space width of n:400 (unit: μm) wiring pattern, exposure was carried out with an energy that made the remaining number of steps of the Stouffer 41-step exposure ruler after development reach 16. After the development process, an optical microscope was used to observe the resist pattern, and the value of the minimum line width (unit: μm) of the complete cured resist line formed was used as the adhesion value to evaluate the adhesion. The smaller this value, the better the adhesion.

[0131] 3. Resolution evaluation

[0132] On the above-mentioned test substrate after film lamination, using photomask data with a wiring pattern having a line width / spacing width of n:n (unit: μm), exposure is performed at an energy level such that the remaining step level after developing the Stouffer 41-step exposure scale reaches 16. After the developing process, the resist pattern is observed using an optical microscope, and the value of the minimum line width at which a complete cured resist line is formed is used as the adhesion value to evaluate adhesion (μm). The smaller this value, the better the resolution.

[0133] 4. Resist Shape Evaluation

[0134] In the resist pattern used for the above-mentioned resolution evaluation, the part with the best resolution is observed using a SU1000 type scanning electron microscope (manufactured by Hitachi). Evaluation is carried out according to the following evaluation criteria:

[0135] ■: 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;

[0136] ○: 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;

[0137] ×: 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.

[0138] The test results of evaluation items 1 - 4 are summarized in Table 2 below.

[0139] Table 2

[0140]

[0141] 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 photosensitivity, adhesion, resolution, resist shape, etc.

[0142] Samples 5 - 7 of the present invention in Table 1 can still obtain good performance by adjusting the types and proportions of each component, indicating that the photosensitizer of the present invention has a wide range of applicability and can be used in combination with different raw materials.

[0143] In contrast, the 9,10-dibutoxyanthracene used in Comparative Sample 1 has poor photosensitive performance. To achieve the same photosensitivity as in the examples, at least 25% more photosensitizer needs to be added additionally. In addition, the resist formed by curing is prone to form an inverted trapezoid.

[0144] The above content is only a 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. Any modification, equivalent substitution or improvement 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 an alkynyl anthracene compound having a structure represented by formula (I) or formula (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 or 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: 。 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 3, wherein The content of the photosensitizer is 0.2-0.5 parts by weight.

5. 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.

6. The photosensitive resin composition according to claim 1, wherein The alkali-soluble resin is copolymerized with (meth)acrylic acid and a copolymerization unit, wherein 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.

7. 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.

8. The photosensitive resin composition according to claim 1, wherein The photopolymerizable monomer is a (meth)acrylate monomer.

9. 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.

10. The photosensitive resin composition according to claim 1, wherein The content of the photopolymerizable monomer is 40-50 parts by weight.

11. The photosensitive resin composition according to claim 10, wherein The content of the photopolymerizable monomer is 45-50 parts by weight.

12. The photosensitive resin composition according to claim 1, wherein The photoinitiator is a 2,4,5-triaryl imidazole dimer.

13. 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.

14. The photosensitive resin composition according to claim 1, wherein The content of the photoinitiator is 2-4 parts by mass.

15. The photosensitive resin composition according to claim 14, wherein The content of the photoinitiator is 2.5-3.5 parts by mass.

16. The photosensitive resin composition according to claim 1, wherein The photosensitive resin composition further comprises one or more additives selected from dyes, photo-developers, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, and coating aids.

17. The photosensitive resin composition according to claim 16, wherein The total amount of the additives is 0.5-5.0 parts by mass.

18. 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 17. 19 . The photosensitive dry film according to claim 18 , wherein the support layer material is polyester, and the protective layer material is polyethylene.

20. Use of the photosensitive dry film according to claim 18 or 19 in the preparation of printed circuit boards, lead frames, semiconductor packaging substrates, solar cells and photocurable inks.

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