An acetylthioproline anthracene methyl ester for a photosensitive resin composition and use thereof

Abstract

The application relates to an acetyl thio proline anthracene methyl ester for a photosensitive resin composition and application thereof, and relates to the field of photopolymerization. The acetyl thio proline anthracene methyl ester has photosensitivity, can be used as a photosensitizer in a photosensitive resin composition, has the effect of improving the adhesion of the photosensitive resin composition on various metal surfaces, has good compatibility with polymerized monomers and solvents, has a low migration characteristic, and can be widely applied to the fields of dry films, paints, coatings, inks and molding materials and the like.

Description

Technical Field

[0001] This invention relates to the field of photopolymerization, and more specifically to an acetylthioproline anthracene methyl ester for use in photosensitive resins and its applications. Background Technology

[0002] Pattern transfer technology is widely used in the manufacture of printed circuit boards (PCBs), lead frames (LFs), and semiconductor packaged (IC) substrates. The process typically involves: bonding a dry film resist onto a copper substrate; exposing the substrate through a mask with a specific pattern; subsequently developing to remove unexposed areas; followed by etching or electroplating to form the pattern; and finally removing the cured dry film using a stripping solution to complete the pattern transfer. The photosensitive resin composition, as the core material for pattern transfer, is a key component of the photosensitive dry film (i.e., dry film resist).

[0003] As electronic products evolve towards miniaturization and high density, higher precision, higher density, and more layers are required for PCBs. For example, in highly integrated PCB products such as high-density interconnect (HDI) boards and packaging substrates, a line accuracy of about 15μm or even smaller is typically required. This necessitates that the dry film resist layer used for pattern transfer has higher resolution and exhibits excellent adhesion on the copper substrate to ensure that it can still firmly adhere to the surface of the copper-clad laminate substrate after undergoing harsh processes such as development, electroplating, or etching, which involve high-pressure spraying and prolonged contact with corrosive chemical reagents.

[0004] In photosensitive resin compositions, a suitable photoinitiation system directly affects its photosensitivity, resolution, and production yield. Currently, the most common anthracene photosensitizers on the market mainly include three types: 9,10-dibutoxyanthracene (DBA), 9,10-diphenylanthracene (DPHA), and 9,10-diacetoxyanthracene (DAcOA). Numerous experiments and literature indicate that, in addition to generally weak adhesion, these photosensitizers also have the following limitations:

[0005] (1) Although 9,10-dibutoxyanthracene photosensitizers have good solubility, their 9,10 CO bond is easily broken during exposure, which can cause anthracene ring dimerization and release small molecule alkoxy fragments. These fragments may migrate from the cured resin to the plating solution during subsequent electroplating, causing pollution and affecting the service life of the plating solution and the quality of electroplating.

[0006] (2) Although DPHA has a high quantum yield, its solubility is poor due to the large size and high rigidity of its molecular conjugated system.

[0007] (3) Due to the electron-withdrawing induction effect of acyl groups, the electron cloud density at the 9 and 10 positions of the anthracene ring increases in DAcOA, thus reducing its efficiency in the catalytic curing reaction. This results in an unsatisfactory verticality of the sidewalls of the cured resin pattern, a significant difference in line width between the top and bottom, and the formation of an "inverted trapezoidal" structure, which is difficult to meet the requirements of high-precision circuit manufacturing. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide an acetylthioproline anthracene methyl ester with photosensitivity that can improve the adhesion of photosensitive resin compositions to metal foil surfaces and its applications.

[0009] The technical solution adopted by the present invention to solve its technical problem is as follows: an acetylthioproline anthracene methyl ester for use in photosensitive resin compositions, comprising:

[0010] , One or two of them.

[0011] Based on the same inventive concept, the present invention also provides a photosensitive resin composition, comprising, by weight, 50-65 parts of alkali-soluble resin, 35-50 parts of photopolymerizable monomer, 2-5 parts of photoinitiator, and 0.1-1 parts of photosensitizer; wherein the photosensitizer comprises the aforementioned acetylthioproline anthracene methyl ester.

[0012] More preferably, the photosensitizer further includes one or more of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

[0013] Preferably, the alkali-soluble resin is an acrylate copolymer containing aromatic groups.

[0014] Preferably, the photopolymerization monomer is an olefinic unsaturated carboxylic acid and / or an olefinic unsaturated carboxylic acid ester.

[0015] Preferably, the photoinitiator is a diimidazole compound.

[0016] Preferably, in the comonomers used to synthesize the alkali-soluble resin, the comonomers having aromatic groups account for 50-70% by mass.

[0017] Preferably, the weight-average molecular weight of the alkali-soluble resin is 20,000 to 60,000.

[0018] Preferably, the acid value of the alkali-soluble resin is 160-220 mg KOH / g.

[0019] Preferably, the molecular weight distribution of the alkali-soluble resin is 1.0 to 3.0.

[0020] Preferably, the photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer.

[0021] Preferably, the photoinitiator is a 2,4,5-triarylimidazolium dimer.

[0022] Preferably, the alkali-soluble resin is obtained by polymerizing one or more of the following: acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, benzyl acrylate derivatives, benzyl methacrylate derivatives, phenyl acrylate, phenyl methacrylate, styrene, and styrene derivatives.

[0023] Preferably, the photopolymerizable monomer is one or more of the following: 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.

[0024] Preferably, the photoinitiator is one or more of 2-(2-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazolium dimer, and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0025] Preferably, by weight, it comprises 55-60 parts of alkali-soluble resin, 40-49 parts of photopolymerizable monomer, 2.2-4 parts of photoinitiator, and 0.1-1 parts of photosensitizer.

[0026] Preferably, it further contains 0.5 to 5.0 parts by weight of additives; the additives are one or more of the following: dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, leveling agents, thickeners, dispersants, lubricants, waterproofing agents, and preservatives.

[0027] Based on the same inventive concept, the present invention also provides a photosensitive dry film, comprising a support layer, a photosensitive resist layer and a protective layer disposed sequentially; the photosensitive resist layer comprises at least one of the acetylthioproline anthracene methyl ester and the photosensitive resin composition.

[0028] Based on the same inventive concept, the present invention also provides the use of one or more of the acetylthioproline anthracene methyl ester, the photosensitive resin composition, and the photosensitive dry film in at least one of a substrate with a resist pattern, a printed circuit board, a lead frame, a semiconductor packaging substrate, a solar cell, and a photocurable ink.

[0029] The present invention has the following beneficial effects: the acetylthioproline anthracene methyl ester of the present invention has photosensitivity and can be used as a photosensitizer in photosensitive resin compositions. It also has the effect of improving the adhesion of photosensitive resin compositions to various metal surfaces, has good compatibility with polymer monomers and solvents, and has low migration characteristics. It can be widely used in the field of photocuring such as dry films, paints, coatings, inks and molding materials.

[0030] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0032] Figure 1 The TM1 manufactured in the embodiments of the present invention 1 H-NMR spectrum;

[0033] Figure 2 The TM1 manufactured in the embodiments of the present invention 13 C-NMR spectrum;

[0034] Figure 3 It is the TM2 manufactured in the embodiment of the present invention. 1 H-NMR spectrum;

[0035] Figure 4 It is the TM2 manufactured in the embodiment of the present invention. 13 C-NMR spectrum;

[0036] Figure 5 These are the ultraviolet-visible absorption spectra of TM1~TM2 prepared according to the embodiments of the present invention;

[0037] Figure 6 This is a photobleaching curve of TM1 prepared according to an embodiment of the present invention under 405nm illumination;

[0038] Figure 7 This is a photobleaching curve of TM2 produced in this embodiment of the invention under 405nm illumination. Detailed Implementation

[0039] To make the objectives, solutions, and beneficial technologies of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. It should be noted that the embodiments described in this specification are merely illustrative of the invention and are not intended to limit the invention.

[0040] For simplicity, this paper only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an undefined range; and any lower limit can be combined with other lower limits to form an undefined range, just as any upper limit can be combined with any other upper limit to form an undefined range. Furthermore, although not explicitly stated, every point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can serve as its own lower or upper limit and be combined with any other point or individual value, or with other lower or upper limits, to form an undefined range.

[0041] In this description, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, "multiple" in "one or more" means two or more, and "more than" in "one or more" means two or more.

[0042] Embodiments of the present invention provide an acetylthioproline anthracene methyl ester for use in photosensitive resin compositions, comprising:

[0043] (abbreviated as TM1) One or two of (abbreviated as TM2).

[0044] This invention discloses a photosensitive resin composition, comprising, by weight, 50-65 parts of alkali-soluble resin, 35-50 parts of photopolymerizable monomer, 2-5 parts of photoinitiator, and 0.1-1 parts of photosensitizer; the photosensitizer includes the aforementioned acetylthioproline anthracene methyl ester. The acetylthioproline anthracene methyl ester is photosensitizing and can be used as a photosensitizer. The "0.1-1 parts" of photosensitizer in the photosensitive resin composition refers to the total amount of acetylthioproline anthracene methyl ester and other photosensitizers.

[0045] When the content of alkali-soluble resin is too low, there is a tendency for the resist to flow into a laminar flow; when the content is too high, there is a tendency for the resolution to decrease.

[0046] When the content of photopolymer monomers is too low, there is a tendency for the sensitivity and chemical resistance of the photoresist to decrease. When the content is too high, the photosensitive resin composition is not easy to form a thin film, and the photoresist tends to flow into a laminar adhesive.

[0047] When the photoinitiator content is too low, there is a tendency for the sensitivity and resolution of the resist to decrease; when the content is too high, there is a tendency for more development debris to appear.

[0048] When the photosensitizer content is too low, the sensitivity of the resist tends to decrease. When the content is too high, the resist substrate tends to be incompletely cured, resulting in an "inverted trapezoidal" cross-sectional shape and poor resolution.

[0049] In some embodiments of the present invention, the photosensitizer further includes one or more of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

[0050] In an embodiment of the present invention, the alkali-soluble resin is an acrylate copolymer containing aromatic groups.

[0051] In embodiments of the present invention, the photopolymerization monomer is an olefinic unsaturated carboxylic acid and / or an olefinic unsaturated carboxylic acid ester.

[0052] In an embodiment of the present invention, the photoinitiator is a diimidazole compound.

[0053] In embodiments of the present invention, the comonomers used to synthesize the alkali-soluble resin contain 50-70% by mass of comonomers having aromatic groups.

[0054] In an embodiment of the present invention, the weight-average molecular weight of the alkali-soluble resin is 20,000 to 60,000.

[0055] In an embodiment of the present invention, the acid value of the alkali-soluble resin is 160-220 mg KOH / g.

[0056] In an embodiment of the present invention, the molecular weight distribution of the alkali-soluble resin is 1.0 to 3.0.

[0057] In embodiments of the present invention, the photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer.

[0058] In an embodiment of the present invention, the photoinitiator is a 2,4,5-triarylimidazolium dimer.

[0059] In embodiments of the present invention, the alkali-soluble resin is obtained by polymerization of one or more of acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, benzyl acrylate derivatives, benzyl methacrylate derivatives, phenyl acrylate, phenyl methacrylate, styrene, and styrene derivatives.

[0060] In embodiments of the present invention, the photopolymerizable monomer is one or more of the following: 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.

[0061] In embodiments of the present invention, the photoinitiator is one or more of 2-(2-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazolium dimer, and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0062] Typical diimidazole compounds, such as hexaaryldiimidazole (HABI), are representative of diimidazole photoinitiators. Their maximum absorption peak is located at 255-275 nm, and they are 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 be matched with UV-A light sources (such as 365 nm LEDs), but is insensitive in the visible light region at 405 nm. This invention uses a photosensitizer to adjust the operating wavelength of diimidazole photoinitiators to around 405 nm.

[0063] In embodiments of the present invention, the product comprises, by weight, 55-60 parts of alkali-soluble resin, 40-49 parts of photopolymerizable monomer, 2.2-4 parts of photoinitiator, and 0.1-1 parts of photosensitizer.

[0064] In some embodiments of the present invention, the photosensitive resin composition containing the acetylthioproline anthracene methyl ester comprises 45 to 48 parts by weight of a photopolymerizable monomer (corresponding to 55 to 60 parts by weight of an alkali-soluble resin).

[0065] In some embodiments of the present invention, the photosensitive resin composition containing the acetylthioproline anthracene methyl ester includes 2.5 to 3.5 parts by weight of a photoinitiator (corresponding to 55 to 60 parts by weight of an alkali-soluble resin).

[0066] In some embodiments of the present invention, the photosensitive resin composition containing the acetylthioproline anthracene methyl ester comprises 0.2 to 0.8 parts by weight of photosensitizer (corresponding to 55 to 60 parts by weight of alkali-soluble resin).

[0067] In embodiments of the present invention, it further contains 0.5 to 5.0 parts by weight of additives; the additives are one or more of the following: dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, leveling agents, thickeners, dispersants, lubricants, waterproofing agents, and preservatives (corresponding to 50 to 65 parts by weight of alkali-soluble resin).

[0068] An embodiment of the present invention provides a photosensitive dry film, comprising a support layer, a photosensitive resist layer, and a protective layer disposed sequentially; the photosensitive resist layer comprises at least one of the acetylthioproline anthracene methyl ester and the photosensitive resin composition.

[0069] The support layer material of the photosensitive dry film is PET.

[0070] The protective layer material of the photosensitive dry film is PE.

[0071] The present invention relates to the application of one or more of the following: acetylthioproline anthracene methyl ester, the photosensitive resin composition, and the photosensitive dry film, in at least one of substrates with resist patterns, printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, and photocurable inks.

[0072] This invention proposes an acetylthioproline anthracene methyl ester, which has the following technical advantages:

[0073] (1) Inhibit migration crystallization: The anthracene group is flexibly linked by methyl groups, avoiding p-π conjugation caused by direct bonding and avoiding the breaking of carbon heterobonds, thereby effectively inhibiting the generation of small molecule fragments and greatly reducing the risk of photosensitizer molecules migrating and diffusing into the PE film.

[0074] (2) Excellent adhesion: By introducing low-valence sulfur-nitrogen five-membered heterocyclic compounds, the adhesion of such photosensitizers to metal foil surfaces, especially copper foil surfaces, is greatly improved;

[0075] (3) Compared with conventional photosensitizers DBA, DPHA and DAcOA in the prior art, the photosensitizer of the present invention adopts a carboxylic acid ester bond between the photosensitive core structure and the adhesion structure, exhibiting superior solubility in various commonly used organic solvents and olefinic acrylate monomers, and exhibiting higher dispersibility in photosensitive resin compositions, providing a wider range of choices for the formulation of photosensitive resin compositions.

[0076] This invention achieves low migration, excellent adhesion, and better dispersion stability through molecular structure innovation, meeting the needs of high-precision, high-density, and multi-layered high-density circuit manufacturing.

[0077] Example

[0078] The following examples describe the disclosure of this invention in more detail. These examples are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight. Unless otherwise stated, all reagents used in the examples are available commercially or synthesized using conventional methods and are ready for use without further processing. Unless otherwise stated, all instruments used in the examples are available commercially.

[0079] (I) Preparation and detection of acetylthioproline anthracene methyl ester

[0080] (1) Preparation of TM1

[0081] The reaction formula for preparing TM1 can be written as:

[0082] .

[0083] The specific preparation method of TM1 is as follows:

[0084] Under a nitrogen atmosphere and with stirring, N-acetylthioproline (1.2 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC, 1 mmol), 4-dimethylaminopyridine (DMAP, 1 mmol), and triethylamine (1.5 mmol) were dissolved in dry dichloromethane (2 mL) in a 50 mL three-necked flask equipped with a magnetic stirrer. After stirring at 0 °C for 2 hours, 9-anthracene methanol (1 mmol) was added and the reaction was continued at this temperature until TLC showed that the 9-anthracene methanol was completely consumed, which took about 2 hours. The resulting reaction mixture was washed with water, extracted with dichloromethane, and washed with saturated brine. The combined organic phases were dried with anhydrous sodium sulfate to obtain the crude product. The crude product was purified by column chromatography to obtain a yellow solid (yield: 83%).

[0085] Figure 1 It's TM1. 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.44 (d, J = 8.4 Hz, 1H), 8.25 (d, J = 8.9 Hz, 2H), 7.97 (t,J = 7.2 Hz, 2H), 7.61 – 7.40 (m, 4H), 6.26 – 6.06 (m, 2H), 5.15 – 4.70 (m, 1H), 4.68 – 4.37 (m, 2H), 3.27 – 3.01(m, 2H), 2.12 – 1.36 (3H, CH3).

[0086] Figure 2 It's TM1. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 170.0, 169.8, 169.1,168.7, 131.3, 131.0, 130.9, 129.7, 129.3, 129.2, 129.1 126.9, 126.8 125.4,125.2 125.1, 125.0, 123.7, 123.4, 62.6, 61.2, 60.6, 60.1, 49.0, 48.5, 34.6,32.9, 22.9, 22.4.

[0087] (2) Preparation of TM2

[0088] The reaction formula for preparing TM2 can be written as:

[0089] .

[0090] The specific preparation method of TM2 is as follows:

[0091] Under nitrogen atmosphere and stirring, N-acetylthioproline (2.4 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC, 2 mmol), 4-dimethylaminopyridine (DMAP, 2 mmol), and triethylamine (3 mmol) were dissolved in dry dichloromethane (4 mL) in a 50 mL three-necked flask equipped with a magnetic stirrer. After stirring at 0 °C for 2 hours, 9,10-anthracene diethanol (1 mmol) was added and the reaction was continued at this temperature until TLC showed that 9,10-anthracene diethanol was completely consumed, which took about 2 hours. The resulting reaction mixture was washed with water, extracted with dichloromethane, and washed with saturated brine. The combined organic phases were dried with anhydrous sodium sulfate to obtain the crude product. The crude product was purified by column chromatography to obtain a yellow solid (yield: 80%).

[0092] Figure 3 It's TM2. 1 H-NMR spectrum; 1H NMR (400 MHz, CDCl3): δ 8.00 (dq, J = 7.0, 3.4Hz, 4H), 7.28 (dd, J = 6.9, 3.7 Hz, 4H), 6.02 – 5.73 (m, 4H), 4.78 (dd, J = 7.0,3.7 Hz, 2H), 4.37 – 4.09 (m, 4H), 2.96 – 2.72 (m, 4H), 1.70 (d, J = 62.4 Hz, 6H).

[0093] Figure 4 It's TM2. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 170.0, 169.9, 169.2,168.9, 130.74, 130.70, 128.6, 128.2, 127.7, 126.8, 126.6, 126.5, 126.1,125.0, 124.7, 124.6, 124.4, 124.2, 62.7, 61.3, 60.7, 60.2, 49.1, 48.6, 34.7,33.0, 23.0, 22.5.

[0094] (3) Ultraviolet-Visible Spectrum

[0095] The UV-Vis absorption spectra were measured using a Shimadzu UV-1900 UV-Vis spectrophotometer. TM1, TM2, and DBA were all measured using toluene as the solvent at a concentration of 4 × 10⁻⁶. -5 The UV absorption of the sample was measured at mol / L. The molar extinction coefficient ε = A was calculated using Beer-Lambert law. bn / c, where A bn ρ represents the absorbance of the UV-Vis absorption spectrum, and c represents the concentration (mol / L). The results are shown in Table 1. The UV-Vis spectra of the prepared TM1~TM2 are shown below. Figure 5 As shown.

[0096] Table 1. Molar extinction coefficients of TM1, TM2, and DBA

[0097]

[0098] As can be seen from the molar extinction coefficients in Table 1, the molar extinction coefficient of acetylthioproline anthracene methyl ester TM1 of the present invention is slightly lower than that of DBA, while that of TM2 is slightly higher than that of DBA; this proves that such photosensitizers have excellent photo-radical conversion capabilities and great photosensitivity potential, thereby initiating the curing of the photosensitive composition.

[0099] (4) Photobleaching experiment

[0100] Using toluene as a solvent (concentration 4×10) -5 The UV-Vis absorption spectrum of the sample solution was measured at fixed intervals using a Shimadzu UV-1900 UV-Vis spectrophotometer under 405nm light source illumination (mol / L). Figure 6 This is a photobleaching curve of TM1 under 405nm illumination conditions; Figure 7 This is a photobleaching curve of TM2 under 405nm illumination; the acetylthioproline anthracene methyl esters TM1~TM2 of this invention have very good photobleaching performance and can be photobleached within 30min or 60min.

[0101] (5) Solubility and compatibility test

[0102] Using TM1, TM2, DBA, DPHA, and DacOA as solutes, their solubility in various solvents and compatibility with monomers were tested. The solutes were added to the solvents at a ratio of 0.1 g solute / 1 g solvent (10% w / w), and the solubility was recorded according to the following classification criteria:

[0103] Advantages: Rapid dissolution; under room temperature and stirring conditions, a clear, transparent, and homogeneous solution can be formed within 1 minute.

[0104] Medium - dissolves slowly; under room temperature and stirring conditions, it can form a clear, transparent and uniform solution in more than 5 minutes; or it cannot completely dissolve at room temperature, but can form a clear, transparent and uniform solution when heated to 50~60℃, and there is no obvious turbidity after returning to room temperature.

[0105] Poor - Partially dissolves; cannot completely dissolve after 5 minutes or more under room temperature and stirring conditions; or can completely dissolve when heated to 50~60℃, but becomes noticeably cloudy after returning to room temperature.

[0106] Table 2. Solubility test results of TM1, TM2, DBA, DPHA and DacOA

[0107]

[0108] The test results are shown in Table 2. The solvents are represented by acetone, toluene, and methanol; the monomers are represented by a mixture consisting of 5g of methoxy polyethylene glycol (350) monoacrylate, 20g of 10(ethoxy)bisphenol A dimethacrylate, 5g of 6(propoxy)bisphenol A dimethacrylate, 10g of 3(ethoxy)trimethylolpropane triacrylate, and 4g of di(trimethylolpropane)tetraacrylate, which is denoted as "monomer" in Table 2.

[0109] As can be seen from the data in Table 2, compared with conventional photosensitizers DBA, DPHA and DAcOA in the prior art, the photosensitizers TM1~TM2 of the present invention exhibit superior solubility in various commonly used organic solvents and good compatibility with monomers.

[0110] (II) Preparation of photosensitive resin composition

[0111] Examples and comparative examples were set up. Examples 1-10 directly used TM1 and TM2 as photosensitizers, while the comparative examples used DBA, DPHA, and DAcOA as photosensitizers, respectively. For ease of comparison, Examples 9 and 10 used the same proportions as Comparative Examples 1-3. Referring to the formulations shown in Table 3, the components were mixed evenly to prepare a photosensitive resin composition. The data in Table 3 are in parts by mass, and "-" indicates that it was not added.

[0112] Table 3 Formulations of the photosensitive resin compositions of Examples 1-10 and Comparative Examples 1-3

[0113]

[0114] The components and specific information of each component code in Table 3 are as follows:

[0115] Alkali-soluble resin (A): Acrylic ester copolymer, solution polymerization, by mass ratio, methacrylic acid / butyl methacrylate / benzyl methacrylate = 25 / 10 / 65; solvent is acetone, solid content 46%, weight average molecular weight 40000, dispersity 2.1, acid value 163mgKOH / g (Hunan Chuyuan New Materials Co., Ltd.).

[0116] Photopolymerizable monomer (B) is composed of the following components (purchased from Sartoma Guangzhou Chemical Co., Ltd.): 5 parts of methoxy polyethylene glycol (350) monoacrylate, 20 parts of 10 (ethoxy) bisphenol A dimethacrylate, 5 parts of 6 (propoxy) bisphenol A dimethacrylate, 10 parts of 3 (ethoxy) trimethylolpropane triacrylate, and 4 parts of di (trimethylolpropane) tetraacrylate.

[0117] Photoinitiator (C): 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-diimidazole (BCIM), purchased from Jiuding Chemical;

[0118] Photosensitizer (D): DBA is 9,10-dibutoxyanthracene, DPHA is 9,10-diphenylanthracene, and DAcOA is 9,10-diacetoxyanthracene, all purchased from Leyan;

[0119] Additive (E) consists of the following ingredients (purchased from Anaiji Chemical): 0.5 parts of leuco crystal violet, 0.05 parts of malachite green, 0.8 parts of p-toluenesulfonamide, and 0.03 parts of 2,6-di-tert-butyl-4-methylphenol;

[0120] The solvent consists of the following components: 8 parts acetone, 10 parts toluene, and 5 parts methanol.

[0121] (III) Preparation of photosensitive dry film

[0122] Photosensitive dry films were prepared using the photosensitive resin compositions of Examples 1-10 and Comparative Examples 1-3 as raw materials, including the following steps:

[0123] Using experimental equipment (model: AB4220, TQC, Netherlands), the prepared photosensitive resin composition slurry was coated onto a 15μm thick polyethylene terephthalate (PET) support film; the solvent was removed by baking at 80℃ for 10min; after baking, the thickness of the photosensitive layer was controlled at 30μm, and then a polyethylene film (PE) was applied for protection to obtain a photosensitive dry film.

[0124] Before coating, acetone solvent can be added to the photosensitive resin composition to adjust it to a suitable viscosity for coating. The solvent will be removed after baking and will not affect the composition of the photosensitive dry film.

[0125] (iv) Preparation of substrates with resist patterns

[0126] Substrates with resist patterns were prepared using the photosensitive resin compositions of Examples 1-10 and Comparative Examples 1-3 as raw materials, and the procedures are as follows:

[0127] (1) Photosensitive layer formation process: A photosensitive layer is formed on a substrate using a photosensitive composition;

[0128] (2) Exposure process: At least a portion of the above photosensitive layer is irradiated with active light to photocur the above area to form a cured area;

[0129] (3) Development process: Remove at least a portion of the above photosensitive layer, excluding the cured area, from the substrate to form a resist pattern on the substrate.

[0130] The operating conditions for each process are explained in detail below.

[0131] Photosensitive layer formation process: Using a copper-clad laminate with a 35μm thick rolled 1.2mm thick copper foil, after surface adjustment and preheating to 80°C, while peeling off the PE protective film of the photosensitive dry film obtained from each embodiment or comparative example, the above-mentioned photosensitive resin composition is laminated onto the copper-clad laminate using a hot roller laminator (Zhisheng Technology Co., Ltd., CSL-M25E) at a roller temperature of 110°C, an air pressure of 0.35MPa, and a lamination speed of 1.5m / min to obtain a test substrate.

[0132] Exposure process: Exposure is performed using a direct drawing exposure machine (Xinge Microelectronics, main wavelength 405nm), and the sensitivity is tested using a Stouffer 41-level step exposure scale, with the number of exposure frames controlled between 14 and 18.

[0133] Development Process: After exposure, the PET support film is peeled off. Using an alkaline developer (manufactured by Guangzhou Julong Printed Circuit Board Equipment Co., Ltd., a dry film developer), a 1wt% Na₂CO₃ aqueous solution at 30°C is sprayed for twice the minimum development time to dissolve and remove the unexposed portions of the photosensitive resin layer. After development, the substrate is rinsed with pure water for 1.5 times the development time, dehydrated using an air knife, and then dried with warm air to obtain a substrate with a cured film for evaluation. The minimum development time is the shortest time required for complete dissolution of the unexposed photosensitive resin layer.

[0134] (v) Evaluation Items

[0135] (1) Evaluation of photosensitivity

[0136] Photosensitivity evaluation tests were conducted on Examples 1-10 and Comparative Examples 1-3. A Stouffer 41-level segmented exposure scale was placed on the test substrate after the film was applied for photosensitivity testing. After the exposure process, the test substrate was left to stand for at least 20 minutes, then the PET film layer was peeled off, and a 1.0 wt% sodium carbonate aqueous solution was sprayed at 30°C to remove the unexposed resist layer. The development time was 2.0 times the minimum development time. After the above operations, a cured film obtained by curing the photosensitive resin composition was formed on the substrate surface. The exposure energy (mJ / cm²) when the number of residual segments on the segmented exposure scale obtained through the cured film was 16 segments. 2 The photosensitivity of the photosensitive resin composition was evaluated, with a smaller value indicating better photosensitivity.

[0137] (2) Adhesion evaluation

[0138] Adhesion evaluation tests were conducted on Examples 1-10 and Comparative Examples 1-3. On the test substrates after film application, photomask data with a wiring pattern of linewidth / spacing width n:400 (unit: μm) was used to expose the substrates at an energy level that resulted in 16 residual stages after development using a Stouffer 41-stage exposure ruler. After the development process, the resist pattern was observed using an optical microscope. The minimum linewidth at which a complete cured resist line was formed was used as the adhesion value to evaluate adhesion (μm). The smaller this value, the better the adhesion.

[0139] (3) Evaluation of corrosion resist migration

[0140] The photoresist migration of Examples 1-10 and Comparative Examples 1-3 was evaluated. After the prepared three-layer photosensitive dry film was completed, the UV absorption spectrum of the dry film was detected using a UV spectrophotometer to obtain the absorbance A1 of the maximum absorption peak in the 350-450 nm range. The dry film was then placed at 30°C for 72 hours. After removing the PE film layer from the surface of the photosensitive dry film, the UV absorption spectra of the PET layer and the photoresist layer were detected using a UV spectrophotometer to obtain the absorbance A2 of the maximum absorption peak in the 350-450 nm range. If the sensitizer migrates to the surface of the PE layer, the absorbance of the maximum absorption peak in the 350-450 nm range of the PET layer and the photoresist layer will decrease, i.e., the absorbance of the sensitizer that migrated to the PE layer is (A1). - A2). Calculate the migration rate of the photosensitizer, i.e., migration rate A = (A1) / (A2). - The larger the value of A2 / A1, the greater the migration amount.

[0141] Basis for judgment:

[0142] ○: Mobility A < 0.01;

[0143] ×: Mobility A > 0.01.

[0144] (4) Evaluation of dispersion stability

[0145] The prepared photosensitive dry film was stored in the dark at 25°C for 2 weeks. The surface of the photosensitive layer was observed under a microscope and graded as follows:

[0146] ■ Indicates a uniform surface of the photosensitive layer;

[0147] × indicates undissolved material precipitated on the surface of the photosensitive layer.

[0148] Table 4. Test results of each evaluation item in Examples 1-10 and Comparative Examples 1-3

[0149]

[0150] Examples 1-10 used TM1-TM2 as photosensitizers and conducted experiments at different dosages. The results of each example in Table 4 show that TM1-TM2 not only greatly reduced the migration rate but also demonstrated excellent adhesion enhancement. The dispersion stability evaluation results of Examples 1-10 show that the obtained resin compositions have excellent stability.

[0151] Examples 9 and 10 used TM1-TM2 as photosensitizers, while Comparative Examples 1-3 used DBA, DPHA, and DAcOA as photosensitizers, respectively, and the amount of photosensitizer used in the above examples was the same. By comparing the results of Examples 9 and 10 with those of Comparative Examples 1-3 in Table 4, it can be seen that the photosensitive resin composition using acetylthioproline anthracene methyl ester as a photosensitizer of the present invention has an exposure energy that is close to that of DBA, higher than that of DPHA, and lower than that of DAcOA under the same mass concentration conditions, indicating that the photosensitivity is similar to that of DBA and superior to that of DAcOA. In addition, acetylthioproline anthracene methyl ester of the present invention shows advantages in terms of adhesion, migration, and dispersion stability.

[0152] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Those skilled in the art can make various modifications and alterations within the spirit and principles of the present invention, and any modifications, equivalent substitutions, or improvements within this scope should be considered as covered by the protection scope of the present invention.

Claims

1. An acetylthioproline anthracene methyl ester for use in photosensitive resin compositions, characterized in that, include: , One or two of them.

2. A photosensitive resin composition, characterized in that, The product comprises, by weight, 50-65 parts of alkali-soluble resin, 35-50 parts of photopolymerizable monomer, 2-5 parts of photoinitiator, and 0.1-1 parts of photosensitizer; wherein the photosensitizer comprises acetylthioproline anthracene methyl ester as described in claim 1.

3. The photosensitive resin composition according to claim 2, characterized in that, The photosensitizer also includes one or more of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

4. The photosensitive resin composition according to claim 2 or 3, characterized in that, The alkali-soluble resin is an acrylate copolymer containing aromatic groups; the photopolymerization monomer is an olefin unsaturated carboxylic acid and / or an olefin unsaturated carboxylic acid ester; and the photoinitiator is a diimidazole compound.

5. The photosensitive resin composition according to claim 2 or 3, characterized in that, In the comonomers used to synthesize the alkali-soluble resin, the comonomers having aromatic groups account for 50-70% by mass; the weight-average molecular weight of the alkali-soluble resin is 20,000-60,000; the acid value of the alkali-soluble resin is 160-220 mg KOH / g; and the molecular weight distribution of the alkali-soluble resin is 1.0-3.

0. The photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer; The photoinitiator is a 2,4,5-triarylimidazolium dimer.

6. The photosensitive resin composition according to claim 2 or 3, characterized in that, The alkali-soluble resin is obtained by polymerizing one or more of the following: acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, phenyl acrylate, phenyl methacrylate, and styrene. The photopolymerizable monomer is one or more of the following: methoxy polyethylene glycol monoacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, di(trimethylolpropane)tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. The photoinitiator is one or more of the following: 2-(2-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazolium 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 2 or 3, characterized in that, By weight, it includes 55-60 parts of alkali-soluble resin, 40-49 parts of photopolymerizable monomer, 2.2-4 parts of photoinitiator, and 0.1-1 parts of photosensitizer.

8. The photosensitive resin composition according to claim 2 or 3, characterized in that, It also contains 0.5 to 5.0 parts by weight of additives; the additives are one or more of the following: dyes, light color developers, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, leveling agents, thickeners, dispersants, lubricants, waterproofing agents, and preservatives.

9. A photosensitive dry film, characterized in that, It includes a support layer, a photoresist layer and a protective layer arranged sequentially; the photoresist layer comprises at least one of the following: acetylthioproline anthracene methyl ester as described in claim 1 or the photosensitive resin composition as described in any one of claims 2 to 8.

10. The use of one or more of the following: acetylthioproline anthracene methyl ester as claimed in claim 1, the photosensitive resin composition as claimed in any one of claims 2 to 8, or the photosensitive dry film as claimed in claim 9, in at least one of a substrate with a resist pattern, a printed circuit board, a lead frame, a semiconductor packaging substrate, a solar cell, and a photocurable ink.

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