Ferrocene carboxylic acid anthracene methyl ester for use in photosensitive resins and resin compositions and applications

Abstract

The present application provides ferrocenyl carboxylic anthracene methyl ester for photosensitive resin, relates to the field of photopolymerization. The present application also includes photosensitive resin composition containing the ferrocenyl carboxylic anthracene methyl ester, photosensitive dry film containing the ferrocenyl carboxylic anthracene methyl ester, and application thereof. The ferrocenyl carboxylic anthracene methyl ester of the present application has photosensitivity, low migration characteristics, can improve the adhesion of photosensitive resin composition on various metal surfaces, and can be widely applied to the field of light curing such as dry film, paint, coating, ink and molding material.

Description

Technical Field

[0001] This invention relates to the field of photopolymerization, specifically to a ferrocene-based carboxylic acid anthracene methyl ester and a photosensitive resin composition and its application. Background Technology

[0002] Photosensitive resin compositions are widely used as key pattern transfer materials in the manufacture of printed circuit boards (PCBs), lead frames (LFs), and semiconductor packaging (IC) substrates. Typically, the photosensitive resin composition is coated onto the surface of a PET support film, and after drying, a protective layer, such as a polyethylene film (PE) protective layer, is tightly bonded to its surface to form a photosensitive dry film (or dry film resist).

[0003] In the pattern transfer process, a dry film resist is first bonded to a copper substrate, and a mask with a certain pattern is used to cover the dry film resist for pattern exposure. Then, a weakly alkaline aqueous solution is used as a developer to remove the unexposed areas, followed by etching or electroplating to form the pattern. Finally, a stripping solution is used to peel off the cured dry film, thereby achieving pattern transfer.

[0004] As electronic devices become thinner and smaller, higher demands are being placed on PCBs towards higher precision, higher density, and multilayering. For example, high-density interconnect (HDI) boards and packaging substrates, which are highly integrated and require high-density PCBs, generally require a precision of around 15μm or even lower. This necessitates that the dry film resist layer, which plays a crucial role in pattern transfer, possess higher resolution and excellent adhesion to the copper substrate. This ensures that the dry film remains intact on the copper-clad laminate substrate even after harsh processes such as development, electroplating, or etching, which involve high-pressure spraying and prolonged contact with corrosive chemicals. Therefore, effectively improving the resolution and adhesion of photosensitive resin compositions is of paramount importance.

[0005] Currently, small-molecule anthracene derivatives, such as 9,10-dibutoxyanthracene (DBA), 9,10-diacetoxyanthracene (DAcOA), and 9,10-diphenylanthracene (DPHA), are widely used as photosensitizers. Typically, to achieve higher photosensitivity and resolution, these photosensitizers need to be used in combination with 2,4,5-triarylimidazolium dimer (HABI) (e.g., patent CN101568883). However, anthracene photosensitizers such as DBA, DAcOA, and DPHA exhibit insufficient adhesion to copper-clad laminate surfaces, directly manifesting as blistering, which significantly impacts product yield. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a ferrocene-based carboxylic acid anthracene methyl ester for photosensitive resins, a resin composition and its application, which improve the adhesion of photosensitive resin compositions to metal foil surfaces.

[0007] The technical solution adopted by this invention to solve its technical problem is as follows: Ferrocene carboxylic acid anthracene methyl ester for photosensitive resin, comprising one or more of the following structures:

[0008] , , , .

[0009] 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 amount of ferrocene carboxylic acid anthracene methyl ester in the photosensitive resin composition is less than 1 part and the concentration is more than 1 ppm.

[0010] Preferably, the photosensitizer comprises the ferrocene carboxylic acid anthracene methyl ester.

[0011] More preferably, the photosensitizer further includes at least one of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

[0012] Preferably, the alkali-soluble resin is an acrylate copolymer containing aromatic groups.

[0013] Preferably, the photopolymerization monomer is an olefinic unsaturated carboxylic acid and / or an olefinic unsaturated carboxylic acid ester.

[0014] Preferably, the photoinitiator is a diimidazole compound.

[0015] Preferably, in the comonomers used to synthesize the alkali-soluble resin, the comonomers having aromatic groups account for 50-70% by mass.

[0016] Preferably, the weight-average molecular weight of the alkali-soluble resin is 20,000 to 60,000.

[0017] Preferably, the acid value of the alkali-soluble resin is 160-220 mg KOH / g.

[0018] Preferably, the molecular weight distribution of the alkali-soluble resin is 1.0 to 3.0.

[0019] Preferably, the photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer.

[0020] Preferably, the photoinitiator is a 2,4,5-triarylimidazolium dimer.

[0021] Preferably, the alkali-soluble resin is obtained by copolymerization of one or more of the following: acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, benzyl acrylate derivative, benzyl methacrylate derivative, phenyl acrylate, phenyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, styrene, and styrene derivatives.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] Preferably, it also contains 0.5 to 5.0 parts by weight of additives; the additives are one or more of dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, and coating aids.

[0026] 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 ferrocene carboxylic acid anthracene methyl ester and the photosensitive resin composition.

[0027] Based on the same inventive concept, the present invention also provides the application of one or more of the ferrocene-based carboxylic acid anthracene methyl ester, the photosensitive resin composition, and the photosensitive dry film in substrates with resist patterns, printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, and photocurable inks.

[0028] The present invention has the following beneficial effects: the ferrocene-based anthracene methyl ester of the present invention has low migration characteristics, which can improve the adhesion of photosensitive resin compositions to various metal surfaces and has photosensitivity; it can be widely used in the field of photocuring such as dry film, paint, coating, ink and molding materials.

[0029] 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

[0030] 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:

[0031] Figure 1 The TM1 manufactured in the embodiments of the present invention 1 H-NMR spectrum;

[0032] Figure 2 The TM1 manufactured in the embodiments of the present invention 13 C-NMR spectrum;

[0033] Figure 3 It is the TM2 manufactured in the embodiment of the present invention. 1 H-NMR spectrum;

[0034] Figure 4 It is the TM2 manufactured in the embodiment of the present invention. 13 C-NMR spectrum;

[0035] Figure 5 It is the TM3 manufactured in the embodiment of the present invention. 1 H-NMR spectrum;

[0036] Figure 6 It is the TM3 manufactured in the embodiment of the present invention. 13 C-NMR spectrum:

[0037] Figure 7 It is the TM4 manufactured in the embodiment of the present invention. 1 H-NMR spectrum;

[0038] Figure 8 It is the TM4 manufactured in the embodiment of the present invention. 13 C-NMR spectrum:

[0039] Figure 9 These are the ultraviolet-visible absorption spectra of TM1~TM4 and DBA prepared according to embodiments of the present invention. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Embodiments of the present invention provide ferrocene-based anthracene methyl ester for use in photosensitive resins, comprising one or more of the following structures:

[0044] (abbreviated as TM1) (abbreviated as TM2) (abbreviated as TM3) (abbreviated as TM4).

[0045] 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; wherein the amount of ferrocene-based anthracene methyl ester is less than 1 part, and the concentration is greater than 1 ppm. The ferrocene-based 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 ferrocene-based anthracene methyl ester and other photosensitizers.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] In embodiments of the present invention, the photosensitizer includes the ferrocene carboxylic acid anthracene methyl ester.

[0051] In some embodiments of the present invention, the photosensitizer further includes at least one of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

[0052] In an embodiment of the present invention, the alkali-soluble resin is an acrylate copolymer containing aromatic groups.

[0053] In embodiments of the present invention, the photopolymerization monomer is an olefinic unsaturated carboxylic acid and / or an olefinic unsaturated carboxylic acid ester.

[0054] In an embodiment of the present invention, the photoinitiator is a diimidazole compound.

[0055] 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.

[0056] In an embodiment of the present invention, the weight-average molecular weight of the alkali-soluble resin is 20,000 to 60,000.

[0057] In an embodiment of the present invention, the acid value of the alkali-soluble resin is 160-220 mg KOH / g.

[0058] In an embodiment of the present invention, the molecular weight distribution of the alkali-soluble resin is 1.0 to 3.0.

[0059] In embodiments of the present invention, the photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer.

[0060] In an embodiment of the present invention, the photoinitiator is a 2,4,5-triarylimidazolium dimer.

[0061] In embodiments of the present invention, the alkali-soluble resin is obtained by copolymerization of one or more of the following: acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, benzyl acrylate derivative, benzyl methacrylate derivative, phenyl acrylate, phenyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, styrene, and styrene derivatives.

[0062] 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.

[0063] 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.

[0064] 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 utilizes a photosensitizer to adjust the operating wavelength of diimidazole photoinitiators to approximately 405 nm.

[0065] 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.

[0066] In some embodiments of the present invention, the photosensitive resin composition containing the ferrocene carboxylic acid anthracene methyl ester comprises 45 to 48 parts by weight of photopolymerizable monomer (corresponding to 55 to 60 parts by weight of alkali-soluble resin).

[0067] In some embodiments of the present invention, the photosensitive resin composition containing the ferrocene carboxylic acid anthracene methyl ester includes 2.5 to 3.5 parts by weight of photoinitiator (corresponding to 55 to 60 parts by weight of alkali-soluble resin).

[0068] In some embodiments of the present invention, the photosensitive resin composition containing the ferrocene carboxylic acid 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).

[0069] In embodiments of the present invention, the additive is further contained in 0.5 to 5.0 parts by weight; the additive is one or more of dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, and coating aids.

[0070] 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 ferrocene carboxylic acid anthracene methyl ester and the photosensitive resin composition.

[0071] The support layer material of the photosensitive dry film is PET.

[0072] The protective layer material of the photosensitive dry film is PE.

[0073] The present invention relates to the application of one or more of the following: ferrocene-based anthracene methyl ester, the photosensitive resin composition, and the photosensitive dry film, in substrates with resist patterns, printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, and photocurable inks.

[0074] Existing anthracene photosensitizers suffer from defects such as migration, crystallization, and insufficient adhesion in photosensitive resin compositions. The inventors of this invention have discovered that 9,10-dialkoxyanthracene photosensitizers experience the breakage of the CO bond at positions 9 and 10 upon exposure, leading to anthracene ring dimerization and the release of small alkoxy fragments. These small fragments migrate from the cured photosensitive resin composition into the electroplating bath during subsequent electroplating processes, causing contamination and affecting the bath's lifespan and electroplating performance. This invention proposes a ferrocene-based anthracene methyl ester, which offers the following technical advantages:

[0075] (1) Inhibition of migration and crystallization: The anthracene group is flexibly linked by methyl groups, avoiding p-π conjugation caused by direct bonding, thus preventing the breaking of carbon heterobonds and inhibiting the migration of small molecule fragments. The ferrocene skeleton increases the molecular volume, hindering the migration and penetration of photosensitizer molecules and reducing the risk of diffusion into the PE film;

[0076] (2) Excellent adhesion: Ferrocene is a broad-spectrum multifunctional ligand that can form stable complexes with a variety of transition metals, such as Pd, Pt, Cu, etc. In addition, Cu and Fe also have very good affinity, and this affinity can greatly enhance the adhesion of such photosensitizers to the copper foil surface.

[0077] Meanwhile, existing anthracene photosensitizers also have certain shortcomings in terms of photosensitivity: short-chain alkoxyanthracene derivatives (similar to DBA) with good solubility are prone to migration in the dry film after initiation due to their initiation mechanism, penetrating to the surface of the polyethylene (PE) protective film and forming crystals, which can cause short circuits, open circuits, and other defects in the resist pattern, or lead to a decrease in photosensitivity due to the photosensitizer penetrating from the photosensitive layer; 9,10-diacetoxyanthracene photosensitizers (DAcOA) have an increased electron cloud density of the 9,10 electrons of the anthracene ring due to the electron-withdrawing inductive effect of the acyl group, thus reducing the efficiency of such photosensitizers in catalytic curing reactions and resulting in lower photosensitivity after curing. The resin composition suffers from poor sidewall verticality and a large difference in line length between the top and bottom, resulting in an "inverted trapezoidal" shape. While DPHA boasts high quantum yield, its large conjugated system and high molecular rigidity lead to poor solubility. The ferrocene-based anthracene methyl ester of this invention exhibits photosensitivity and can replace or partially replace existing anthracene photosensitizers in photosensitive resins, while simultaneously enhancing adhesion to metal foil surfaces. When used in very small amounts in photosensitive resins, it primarily enhances adhesion; when used at doses close to conventional photosensitizer levels, it demonstrates both outstanding photosensitizer effects and enhanced adhesion. This invention, through molecular structural innovation, simultaneously achieves low migration and excellent adhesion, meeting the demands of high-precision, high-density, and multilayered high-density circuit manufacturing.

[0078] Example

[0079] 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.

[0080] (I) Preparation and detection of ferrocene carboxylic acid anthracene methyl ester

[0081] (1) Preparation of TM1

[0082] The reaction formula for preparing TM1 can be written as:

[0083] .

[0084] The specific preparation method of TM1 is as follows:

[0085] 9-Bromomethylanthracene (1 mmol, 275 mg), ferrocene (3 mmol, 690 mg), sodium hydroxide (2 mmol, 80 mg), and tetrabutylammonium bromide (0.2 mmol, 644 mg) were added to a 10 mL single-necked flask equipped with a magnetic stirrer, and the mixture was purged with nitrogen three times. 5 mL of toluene was added, the mixture was stirred, and the temperature was raised to 60 °C for reaction monitoring. During the reaction, samples were taken for TLC monitoring. Once the reactants had largely reacted and the reaction solution had returned to room temperature, the reaction solution was transferred to a separatory funnel and extracted three times with DCM. The organic phase was dried over anhydrous Na₂SO₄, and the solvent was removed by vacuum distillation. The crude product was separated by column chromatography (petroleum ether / dichloromethane) to obtain an orange-yellow solid TM1 (350 mg product, 80% yield).

[0086] Figure 1 It's TM1. 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.54 (s, 1H), 8.51 (s, 2H), 7.64 (t, J = 7.50 Hz, 2H), 7.53 (t, J = 7.50 Hz, 2H), 6.30 (s, 2H), 4.75 (t, J = 1.99 Hz, 2H), 4.30 (t, J = 1.96 Hz, 2H), 3.83 (s, 5H).

[0087] Figure 2 It's TM1. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 171.9, 131.6, 131.1, 129.2, 129.1, 127.1, 126.6, 125.2, 124.4, 71.4, 71.0, 70.4, 69.7, 58.8.

[0088] (2) Preparation of TM2

[0089] The reaction formula for preparing TM2 can be written as:

[0090] .

[0091] The specific preparation method of TM2 is as follows:

[0092] 9-Bromomethylanthracene (1 mmol, 275 mg), 3-carboxypropionylferrocene (2 mmol, 572 mg), sodium hydroxide (2 mmol, 80 mg), and tetrabutylammonium bromide (0.2 mmol, 644 mg) were added to a 10 mL single-necked flask equipped with a magnetic stirrer, and the mixture was purged with nitrogen three times. 5 mL of toluene was added, the mixture was stirred, and the temperature was raised to 60 °C for reaction monitoring. Samples were taken during the reaction for TLC monitoring. After the reactants had reacted substantially completely, the reaction solution was allowed to return to room temperature. The reaction solution was transferred to a separatory funnel and extracted three times with DCM. The organic phase was dried over anhydrous Na₂SO₄, and the solvent was removed by vacuum distillation. The crude product was separated by column chromatography (petroleum ether / dichloromethane) to obtain an orange-yellow solid TM₂ (420 mg product, 85% yield).

[0093] Figure 3 It's TM2. 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.51 (s, 1H), 8.38 (d, J =8.87 Hz, 2H), 8.03 (d, J = 7.97 Hz, 2H), 7.57 (t, J = 8.16 Hz, 2H), 7.50 (t, J =8.08 Hz, 2H), 6.21 (s, 2H), 4.78 (t, J = 1.92 Hz, 2H), 4.48 (t, J = 1.93 Hz, 2H), 4.21 (s, 5H), 3.07 (t, J = 6.63 Hz, 2H), 2.72 (t, J = 6.63 Hz, 2H).

[0094] Figure 4 It's TM2. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 202.2, 173.5, 131.5,131.2, 129.2, 126.8, 126.6, 125.3, 124.2, 124.0, 72.3, 70.0(bs), 69.3, 59.3,57.6, 34.3, 28.1.

[0095] (3) Preparation of TM3

[0096] The reaction formula for preparing TM3 can be written as:

[0097] .

[0098] The specific preparation method of TM3 is as follows:

[0099] 9,10-Dibromomethylanthracene (1 mmol, 275 mg), ferrocene (2 mmol, 460 mg), sodium hydroxide (2 mmol, 80 mg), and tetrabutylammonium bromide (0.2 mmol, 644 mg) were added to a 10 mL single-necked flask equipped with a magnetic stirrer, and the mixture was purged with nitrogen three times. 5 mL of toluene was added, the mixture was stirred, and the temperature was raised to 60 °C for reaction monitoring. Samples were taken during the reaction for TLC monitoring. After the reactants had largely reacted and the reaction solution had returned to room temperature, the reaction solution was transferred to a separatory funnel and extracted three times with DCM. The organic phase was dried over anhydrous Na₂SO₄, and the solvent was removed by vacuum distillation. The crude product was separated by column chromatography (petroleum ether / dichloromethane) to obtain an orange-yellow solid TM₃ (620 mg product, 88% yield).

[0100] Figure 5 It's TM3. 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.58 (dd, J = 6.90, 3.29Hz, 4H), 7.68 (dd, J = 6.95, 3.23 Hz, 4H), 6.32 (s, 4H), 4.71 (t, J = 2.02 Hz, 4H), 4.30 (t, J = 2.00 Hz, 4H), 3.87 (s, 10H).

[0101] Figure 6 It's TM3. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 171.9, 131.0, 129.4, 126.4, 125.2, 71.5, 70.9, 70.4, 69.8, 58.9.

[0102] (4) Preparation of TM4

[0103] The reaction formula for preparing TM4 can be written as:

[0104] .

[0105] The specific preparation method of TM4 is as follows:

[0106] To a 10 mL single-necked flask equipped with a magnetic stirrer, add 9-bromomethylanthracene (1 mmol, 275 mg), 1,1'-ferrocene dicarboxylic acid (2 mmol, 548 mg), sodium hydroxide (2 mmol, 80 mg), and tetrabutylammonium bromide (0.2 mmol, 644 mg), and purge with nitrogen three times. Add 5 mL of toluene, start stirring, and heat to 60 °C for reaction, taking samples for TLC monitoring during the reaction. After the reactants have reacted substantially completely, allow the reaction solution to return to room temperature, transfer the reaction solution to a separatory funnel, and extract three times with DCM. Dry the organic phase with anhydrous Na₂SO₄ and remove the solvent by vacuum distillation. Separate the crude product by column chromatography (petroleum ether / dichloromethane) to obtain an orange-yellow solid TM4 (422 mg product, yield 84%).

[0107] Figure 7 It's TM4. 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.51 (s, 2H), 8.45 (d, J =8.87 Hz, 4H), 8.02 (d, J = 8.36 Hz, 4H), 7.52 (t, J = 7.22 Hz, 4H), 7.45 (t, J =7.98 Hz, 4H), 6.25 (s, 4H), 4.55 (t, J = 1.96 Hz, 4H), 3.82 (t, J = 1.99 Hz, 4H).

[0108] Figure 8 It's TM4. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 170.7, 131.6, 131.2, 129.2, 129.2, 126.8, 126.7, 125.3, 124.4, 73.2, 72.4, 71.6, 59.1.

[0109] (5) Ultraviolet-visible spectrum

[0110] The UV-Vis absorption spectra were measured on a Shimadzu UV-1900 UV-Vis spectrophotometer using toluene as the solvent (concentrations are shown in Table 1). The molar extinction coefficient ε = A was calculated according to Beer-Lambert's 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~TM4 and DBA are shown below. Figure 9 As shown.

[0111] Table 1. Molar extinction coefficients of TM1~TM4 and DBA

[0112]

[0113] As can be seen from the molar extinction coefficients in Table 1, the molar extinction coefficients of the ferrocene carboxylic acid anthracene methyl ester of the present invention are all similar to or higher than those of DBA, especially TM3, which is more than twice as high in the same wavelength band; indicating that this type of photosensitizer has a strong light absorption capacity.

[0114] (II) Preparation of photosensitive resin composition

[0115] Examples and comparative examples were set up. Examples 1-8 directly used TM1-TM4 as photosensitizers. Examples 9-20 added a small amount of TM1-TM4 to the resin composition containing existing photosensitizers. Referring to the formulations shown in Tables 2 and 3, the components were mixed evenly to prepare the photosensitive resin composition. The data in Table 2 are in parts by mass, and the amounts of TM1-TM4 in Table 3 are in ppm. The amounts of other items are in parts by mass. "-" indicates that it was not added.

[0116] The components and specific information of each component code in Tables 2 and 3 are as follows:

[0117] 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.).

[0118] 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.

[0119] Photoinitiator (C): 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-diimidazole (BCIM), purchased from Jiuding Chemical.

[0120] Photosensitizer (D): DBA is 9,10-dibutoxyanthracene, DPHA is 9,10-diphenylanthracene, and DAcOA is 9,10-diacetoxyanthracene, all purchased from Leyan.

[0121] Table 2 Formulations of the photosensitive resin compositions of Examples 1-8 and Comparative Examples 1-3

[0122]

[0123] Table 3 Formulations of the photosensitive resin compositions in Examples 9-20

[0124]

[0125] Additive (E) consists of the following ingredients (purchased from Anage 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.

[0126] The solvent consists of the following components: 8 parts acetone, 10 parts toluene, and 5 parts methanol.

[0127] (III) Preparation of photosensitive dry film

[0128] Photosensitive dry films were prepared using the photosensitive resin compositions of Examples 1-20 and Comparative Examples 1-3 as raw materials, including the following steps:

[0129] 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.

[0130] 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.

[0131] (iv) Preparation of substrates with resist patterns

[0132] Substrates with resist patterns were prepared using the photosensitive resin compositions of Examples 1-20 and Comparative Examples 1-3 as raw materials, and the procedures are as follows:

[0133] (1) Photosensitive layer formation process: A photosensitive layer is formed on a substrate using a photosensitive composition;

[0134] (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;

[0135] (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.

[0136] The operating conditions for each process are explained in detail below.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] (v) Evaluation Items

[0141] (1) Evaluation of photosensitivity

[0142] Photosensitivity evaluation tests were conducted using Examples 1-8 and Comparative Examples 1-3. A Stouffer 41-level segmented exposure scale was placed on the above-mentioned film-coated test substrate 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 was measured.2 The photosensitivity of the photosensitive resin composition was evaluated, with a smaller value indicating better photosensitivity.

[0143] (2) Adhesion evaluation

[0144] Adhesion evaluation tests were conducted using Examples 1-20 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.

[0145] (3) Evaluation of corrosion resist migration

[0146] Using the resist migration evaluation tests of Examples 1-8 and Comparative Examples 1-3, after preparing the above-mentioned three-layer photosensitive dry film, the ultraviolet absorption spectrum of the dry film was detected using an ultraviolet spectrophotometer to obtain the absorbance A1 of the maximum absorption peak in the 350-450 nm range. After placing the dry film at 30°C for 72 hours, the PE film layer on the surface of the photosensitive dry film was removed, and the ultraviolet absorption spectra of the PET layer and the photosensitive resist layer were detected using an ultraviolet 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 wavelength range of the PET layer and the photosensitive resist 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.

[0147] Basis for judgment:

[0148] ○: Mobility A < 0.01;

[0149] ×: Mobility A > 0.01.

[0150] The test results for each evaluation item are summarized in Tables 4 and 5 below.

[0151] Examples 1-8 used TM1-TM4 as photosensitizers, and Comparative Examples 1-3 used DBA, DPHA, and DAcOA as photosensitizers, respectively, with the same amount of photosensitizer used in all examples. The results in Table 4 show that the photosensitive resin composition using ferrocene-based anthracene methyl ester as a photosensitizer of the present invention has lower exposure energy under the same mass concentration conditions, indicating that its photosensitivity is superior to DBA and DAcOA. In addition, the ferrocene-based anthracene methyl ester of the present invention shows advantages in terms of adhesion and migration.

[0152] Examples 9-20 show that TM1-TM4 were added in small amounts to the photosensitizer DBA-containing photosensitive resin composition. The results in Table 5 show that even when a very small amount (as low as 1 ppm) of the ferrocene-based anthracene methyl ester of the present invention is used in the photosensitive resin composition, a significant adhesion-enhancing effect can still be exhibited. The above results indicate that the ferrocene-based anthracene methyl ester of the present invention has a wide range of applicability.

[0153] Table 4. Test results of each evaluation item in Examples 1-8 and Comparative Examples 1-3

[0154]

[0155] Table 5 Adhesion test results for Examples 9-20

[0156]

[0157] 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. A photosensitive resin composition, characterized by comprising: The photosensitive resin composition comprises 50-65 parts by mass of alkali-soluble resin, 35-50 parts by mass of photopolymerization monomer, 2-5 parts by mass of photoinitiator, and 0.1-1 parts by mass of photosensitizer; the photosensitizer comprises ferrocenyl carboxylic acid anthracene methyl ester; the amount of ferrocenyl carboxylic acid anthracene methyl ester in the photosensitive resin composition is less than or equal to 1 part, and the concentration of ferrocenyl carboxylic acid anthracene methyl ester is greater than or equal to 1 ppm; The ferrocenyl carboxylic acid anthracene methyl ester comprises one or more of the following structures: 、 、 、 。 2. The photosensitive resin composition according to claim 1, characterized by The photosensitizer further comprises at least one of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

3. The photosensitive resin composition according to claim 1 or 2, characterized by The alkali-soluble resin is an acrylate copolymer containing aromatic groups; the photopolymerization monomer is an olefinically unsaturated carboxylic acid and / or an olefinically unsaturated carboxylic acid ester; and the photoinitiator is a bis-imidazole compound.

4. The photosensitive resin composition according to claim 1 or 2, characterized by In the comonomer used for synthesizing the alkali-soluble resin, the comonomer having aromatic groups accounts 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-triaryl imidazole dimer.

5. The photosensitive resin composition according to claim 1 or 2, characterized by The alkali-soluble resin is obtained by copolymerization of two or more of acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, phenyl acrylate, phenyl methacrylate, and styrene. The photopolymerization monomer is 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. The photoinitiator is one or more of 2-(2-chlorophenyl)-4,5-diphenyl imidazole dimer, 2-(2-chlorophenyl)-4,5-di(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-tri(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-biimidazole.

6. The photosensitive resin composition according to claim 1 or 2, characterized by The photosensitive resin composition comprises 55-60 parts by mass of alkali-soluble resin, 40-49 parts by mass of photopolymerization monomer, 2.2-4 parts by mass of photoinitiator, and 0.1-1 parts by mass of photosensitizer.

7. The photosensitive resin composition according to claim 1 or 2, characterized by Further, 0.5 to 5.0 parts by mass of an additive is contained; the additive is one or two or more of a dye, a phototoner, a plasticizer, an adhesion promoter, a polymerization inhibitor, and an antifoaming agent.

8. A photosensitive dry film characterized by comprising: The photosensitive dry film includes, in this order, a support layer, a photosensitive resist layer, and a protective layer; the photosensitive resist layer includes the photosensitive resin composition according to any one of claims 1 to 7.

9. Use of one or two or more of the photosensitive resin composition according to any one of claims 1 to 7 or the photosensitive dry film according to claim 8 in a substrate with a resist pattern, a printed circuit board, a lead frame, a semiconductor package substrate, a solar cell, and a photocurable ink.

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