Photosensitive resin composition, dry film resist, photosensitive dry film, and use thereof

Abstract

The present application provides a photosensitive resin composition, dry film resist, photosensitive dry film and application thereof. The photosensitive resin composition comprises 45-60 parts of alkali-soluble resin, 35-50 parts of photopolymerization monomer, 2.5-5 parts of photoinitiator and 0.1-0.8 parts of sensitizer; the sensitizer is a compound shown in the general formula, R1 represents methylene or carbonyl, n represents 0 or 1; R2 represents phenyl, and any hydrogen atom on R2 is optionally substituted by methoxy, C1-C 10 alkyl, phenyl, benzyl or phenoxy. The sensitizer of the present application can make the product have better photosensitivity and resolution. Moreover, based on the above specific weight parts of alkali-soluble resin, photopolymerization monomer, photoinitiator and sensitizer, the comprehensive performance of the product of the present application is better.

Description

Technical Field

[0001] This invention relates to the field of photosensitive resin technology, and more specifically, to a photosensitive resin composition, a dry film resist, a photosensitive dry film, and their applications. Background Technology

[0002] Photosensitive resin compositions are widely used as resist materials for etching or electroplating in the manufacturing process of printed circuit boards (PCBs), lead frames (LFs), and semiconductor packaged (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 adhered to its surface; this is also known as a photosensitive dry film or dry film resist.

[0003] With the continuous trend towards lighter and thinner electronic devices, the market is demanding increasingly refined and high-density PCB circuitry. As a manufacturing method for forming fine wiring, the semi-additive process (SAP) directly forms resist patterns on thin copper, followed by pattern electroplating to increase the conductor copper thickness, then removing the resist pattern, and finally rapid etching to remove the exposed base copper to form the circuitry. This method can effectively produce fine circuitry with linewidths and spacings below 25μm. Laser direct imaging (LDI) offers excellent alignment accuracy and can efficiently form fine resist patterns, making it widely used in the fabrication of high-density packaging substrates. Traditional photomask exposure methods consume a large amount of film, resulting in high production costs, and the precision of the exposed circuitry is limited. Compared to the one-time exposure of the entire board using photomask exposure, laser direct imaging systems use point or matrix light sources to gradually scan and create the resist pattern, resulting in superior exposure accuracy and the ability to form high-density photosensitive resist patterns that were previously difficult to achieve. The development of printed circuit board technology and semiconductor packaging technology is driving the trend towards higher density and finer details in electronic circuitry. Laser direct imaging (LDI) technology has been increasingly widely used due to its advantages such as high alignment accuracy and fast production efficiency.

[0004] To improve resolution, a suitable sensitizer needs to be added to the photosensitive resin composition. For the photosensitive resin composition, a suitable photoinitiation system directly affects photosensitivity, resolution, and production yield. Anthracene compounds or anthracene derivatives are widely used in high-resolution LDI photosensitive resists due to their good photosensitivity and resolution. For example, alkoxy or aryl-substituted anthracene compounds are often added as sensitizers in dry film resists used for encapsulating substrates. For instance, patent CN101568883B discloses a photosensitive resin composition containing a benzene-containing alkali-soluble resin combined with a 9,10-dibutoxyanthracene sensitizer, achieving high photosensitivity and resolution. Another example is patent CN110446976A, which discloses a photosensitive resin composition containing alkoxyanthracene or phenylanthracene sensitizers, exhibiting good resolution and adhesion.

[0005] However, based on the results of the aforementioned patent embodiments, the resolution remains relatively low. Furthermore, those skilled in the art have discovered that: Firstly, when the photosensitive resin composition contains alkoxy-substituted anthracene compounds such as 9,10-diethoxyanthracene and / or 9,10-dibutoxyanthracene, these compounds tend to permeate into the polyethylene film (PE) surface and crystallize, potentially causing short circuits or open circuits in the resist pattern, leading to a decrease in product yield. Simultaneously, the easy permeation of these compounds from the PE film also poses a risk of decreased photosensitivity due to the sensitizer penetrating from the photosensitive layer. Secondly, when the photosensitive resin composition contains anthracene derivatives such as 9,10-diphenylanthracene, it suffers from a slow dissolution rate during resin formulation, which can lead to insufficient production efficiency. Moreover, a slow dissolution rate can also cause problems such as filter clogging due to incomplete dissolution, negatively impacting production and processing.

[0006] Therefore, it is necessary to provide a photosensitive resin composition with a fast dissolution rate and low migration and precipitation, so that it can simultaneously possess excellent photosensitivity, resolution, yield and adhesion, in order to improve the above-mentioned problems. Summary of the Invention

[0007] The main objective of this invention is to provide a photosensitive resin composition, a dry film resist, a photosensitive dry film, and their applications, in order to solve the problems existing in the prior art of photosensitive resin compositions, such as poor photosensitivity, low yield, poor resolution, or poor adhesion.

[0008] To achieve the above objectives, according to one aspect of the present invention, a photosensitive resin composition is provided, comprising, by weight, 45-60 parts of an alkali-soluble resin, 35-50 parts of a photopolymerizable monomer, 2.5-5 parts of a photoinitiator, and 0.1-0.8 parts of a sensitizer; the sensitizer is a compound represented by the following general formula I:

[0009]

[0010] In general formula I, R1 represents methylene or carbonyl, and n represents 0 or 1; R2 represents phenyl, and any hydrogen atom on R2 may optionally be replaced by a methoxy group, C1-C64 group, or C1-C64 group. 10 It is substituted by straight-chain or branched alkyl, phenyl, benzyl, or phenoxy compounds.

[0011] Furthermore, any hydrogen atom on R2 can optionally be replaced by a methoxy group, C1-C... 10 It is replaced by straight-chain or branched alkyl groups.

[0012] Further, the sensitizer is selected from 9,10-diphenoxyanthracene, 9,10-di(2-methylphenoxy)anthracene, 9,10-di(2-methoxyphenoxy)anthracene, 9,10-di(3-methylphenoxy)anthracene, 9,10-di(4-ethylphenoxy)anthracene, 9,10-di(4-propylphenoxy)anthracene, 9,10-di(4-butylphenoxy)anthracene, 9,10-di(4-tert-butylphenoxy)anthracene, 9,10-di(4-pentylphenoxy)anthracene, 9,10-di(4-hexylphenoxy)anthracene, 9,10-di(4-nonylphenoxy)anthracene, 9,10-di(benzylmethoxy)anthracene, 9,10-di(2-methylbenzylmethoxy)anthracene, 9,10-di(3-methylbenzylmethoxy)anthracene, and 9,10-di(2,3-dimethylbenzylmethoxy)anthracene. The sensitizer is selected from one or more of 9,10-bis(2,4-dimethylbenzoxy)anthracene, 9,10-bis(2,3,4,5,6-pentamethylbenzoxy)anthracene, 9,10-bis(benzoyloxy)anthracene, 9,10-bis(2-methylbenzoyloxy)anthracene, 9,10-bis(3-methylbenzoyloxy)anthracene, 9,10-bis(4-methylbenzoyloxy)anthracene, 9,10-bis(3,5-dimethylbenzoyloxy)anthracene, 9,10-bis(4-butylbenzoyloxy)anthracene, or 9,10-bis(4-hexylbenzoyloxy)anthracene; more preferably, the sensitizer is selected from one or more of 9,10-bis(4-hexylphenoxy)anthracene, 9,10-bis(2,4-dimethylbenzoxy)anthracene, or 9,10-bis(2-methylbenzoyloxy)anthracene.

[0013] Further, the alkali-soluble resin is obtained by copolymerization of (meth)acrylate monomers, optionally alkyl (meth)acrylate monomers, and comonomers having aromatic groups; preferably, the copolymerization ratio of comonomers having aromatic groups is 50-70% based on the total weight of comonomers during the copolymerization process; preferably, the comonomers having aromatic groups are selected from one or more of phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, styrene, or o-phenylphenoxyethyl acrylate; more preferably, the comonomers having aromatic groups are selected from one or more of benzyl (meth)acrylate, styrene, and o-phenylphenoxyethyl acrylate. Preferably, the alkyl (meth)acrylate monomers are selected from butyl methacrylate and / or methyl methacrylate.

[0014] Furthermore, the weight-average molecular weight of the alkali-soluble resin is between 20,000 and 60,000, the resin acid value is between 150 and 220 mg KOH / g, and the molecular weight distribution is between 1.0 and 3.0.

[0015] Further, the photopolymerization monomer is an olefinically unsaturated double bond monomer; preferably, the photopolymerization monomer is selected from one or more of ethoxylated nonylphenol acrylate, propionylphenol acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated diacrylate, ethoxylated dimethacrylate, propionyl diacrylate, ethoxylated trimethylolpropane tri(meth)acrylate, or ethoxylated pentaerythritol tetraacrylate; more preferably, the photopolymerization monomer is selected from ethoxylated dimethacrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated nonylphenol acrylate, and ethoxylated trimethylolpropane trimethacrylate.

[0016] Further, the photoinitiator is a triarylimidazolium dimer derivative; preferably, the photoinitiator is selected from one or more of 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazolium dimer, or 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0017] Furthermore, the photosensitive resin composition further includes 0.5 to 5.0 parts by weight of additives; preferably, the additives are selected from one or more of dyes, colorants, antioxidants, plasticizers, defoamers, leveling agents or polymerization inhibitors.

[0018] To achieve the above objectives, according to one aspect of the present invention, a photosensitive dry film is provided, comprising a PE film layer, a photosensitive resist layer, and a PET film layer disposed sequentially from top to bottom; wherein the material of the photosensitive resist layer is the aforementioned photosensitive resin composition.

[0019] According to another aspect of the present invention, an application of the aforementioned photosensitive dry film in the manufacturing process of printed circuit boards, lead frames, or semiconductor packaging substrates is provided.

[0020] First, the sensitizer of this invention enables the product to have superior photosensitivity and resolution. In particular, this sensitizer does not migrate from the polyethylene film (PE) during subsequent applications, thus avoiding the tendency to permeate to the PE surface and form crystals. This prevents short circuits, open circuits, and other defects in the resist pattern, resulting in a higher product yield. Simultaneously, this type of sensitizer is also less prone to permeation from the PE film, eliminating the risk of decreased photosensitivity due to sensitizer penetration from the photosensitive layer. Furthermore, this sensitizer has a superior dissolution rate, thereby improving production efficiency and avoiding problems such as filter clogging caused by insufficient dissolution, resulting in better processing performance. Second, the synergistic effect of the specific weight proportions of the alkali-soluble resin, photopolymerizable monomer, photoinitiator, and sensitizer is even better. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0022] As described in the background section of this invention, existing photosensitive resin compositions suffer from problems such as poor photosensitivity, low yield, poor resolution, or poor adhesion. To address this issue, this invention provides a photosensitive resin composition comprising, by weight, 45-60 parts of an alkali-soluble resin, 35-50 parts of a photopolymerizable monomer, 2.5-5 parts of a photoinitiator, and 0.1-0.8 parts of a sensitizer; the sensitizer is a compound represented by the following general formula I, where R1 represents methylene or carbonyl, n represents 0 or 1, R2 represents phenyl, and any hydrogen atom on R2 is optionally replaced by a methoxy group, C1-C64 ... 10 It is substituted with straight-chain or branched alkyl, phenyl, benzyl or phenoxy compounds.

[0023]

[0024] Firstly, based on the specific synergistic effect of R1 and R2 mentioned above, firstly, such a sensitizer can give the product superior photosensitivity and resolution. Secondly, such a sensitizer will not migrate from the polyethylene film (PE) during subsequent applications, thus avoiding the tendency to permeate to the PE film surface and precipitate to form crystals, thereby preventing adverse phenomena such as short circuits and open circuits in the resist pattern, resulting in a higher product yield. Simultaneously, this type of sensitizer is also less prone to permeation from the PE film, thus eliminating the risk of decreased photosensitivity due to sensitizer permeation from the photosensitive layer. Thirdly, in such a sensitizer, the 9,10 substituents of anthracene have -O-, -OCH2- and other groups can improve the dissolution rate, thereby improving product production efficiency and avoiding problems such as filter clogging caused by insufficient dissolution, resulting in better production and processing performance.

[0025] Secondly, based on the specific weight parts of the alkali-soluble resin, photopolymerizable monomer, photoinitiator, and sensitizer mentioned above, the synergistic effect is even better. When the weight part of the alkali-soluble resin is less than 45 parts, the photosensitive resin composition is prone to overflow and is not easy to store; while when the weight part of the alkali-soluble resin is more than 60 parts, there is a risk of deterioration in product resolution. When the weight part of the photopolymerizable monomer is less than 35 parts, the photosensitive resin composition is prone to resolution reduction; while when the weight part of the photopolymerizable monomer is more than 50 parts, the photosensitive layer is prone to overflow. When the weight part of the sensitizer is less than 0.1 parts, the photosensitivity of the subsequently obtained dry film resist is insufficient; while when the weight part of the sensitizer is more than 0.8 parts, there is a risk that the dry film resist layer will cure too quickly on the surface and not enough on the bottom, resulting in a trapezoidal shape and deterioration in resolution of the resisted lines.

[0026] To further improve the dissolution rate of the photosensitive resin composition, preferably any hydrogen atom on R2 is optionally replaced by a methoxy group, C1-C2, or C2-C2. 10 The sensitizer is substituted with straight-chain or branched alkyl groups. More preferably, the sensitizer is selected from 9,10-diphenoxyanthracene, 9,10-di(2-methylphenoxy)anthracene, 9,10-di(2-methoxyphenoxy)anthracene, 9,10-di(3-methylphenoxy)anthracene, 9,10-di(4-ethylphenoxy)anthracene, 9,10-di(4-propylphenoxy)anthracene, 9,10-di(4-butylphenoxy)anthracene, 9,10-di(4-tert-butylphenoxy)anthracene, 9,10-di(4-pentylphenoxy)anthracene, 9,10-di(4-hexylphenoxy)anthracene, 9,10-di(4-nonylphenoxy)anthracene, 9,10-di(benzylmethoxy)anthracene, 9,10-di(2-methylbenzylmethoxy)anthracene, One or more of the following: 9,10-bis(3-methylbenzoxy)anthracene, 9,10-bis(2,3-dimethylbenzoxy)anthracene, 9,10-bis(2,4-dimethylbenzoxy)anthracene, 9,10-bis(2,3,4,5,6-pentamethylbenzoxy)anthracene, 9,10-bis(benzoyloxy)anthracene, 9,10-bis(2-methylbenzoyloxy)anthracene, 9,10-bis(3-methylbenzoyloxy)anthracene, 9,10-bis(4-methylbenzoyloxy)anthracene, 9,10-bis(3,5-dimethylbenzoyloxy)anthracene, 9,10-bis(4-butylbenzoyloxy)anthracene, or 9,10-bis(4-hexylbenzoyloxy)anthracene. More preferably, the sensitizer is selected from one or more of 9,10-bis(4-hexylphenoxy)anthracene, 9,10-bis(2,4-dimethylbenzoxy)anthracene or 9,10-bis(2-methylbenzoyloxy)anthracene.

[0027] To further improve product resolution, in a preferred embodiment, the alkali-soluble resin is obtained by copolymerizing (meth)acrylic acid, optionally alkyl (meth)acrylate monomers, and comonomers having aromatic groups. Preferably, the comonomers having aromatic groups are selected from one or more of phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, styrene, or o-phenylphenoxyethyl acrylate. More preferably, the comonomers having aromatic groups are selected from one or more of benzyl (meth)acrylate, styrene, and o-phenylphenoxyethyl acrylate. Preferably, the alkyl (meth)acrylate monomers are selected from butyl methacrylate and / or methyl methacrylate.

[0028] To improve product resolution and adhesion, the copolymerization ratio of comonomers with aromatic groups is preferably 50% or higher. However, to improve the release effect, the copolymerization ratio of comonomers with aromatic groups is preferably 70% or lower. To further balance the resolution, adhesion, and release effect of the resist layer, preferably, the copolymerization ratio of comonomers with aromatic groups is 50% to 70% based on the total weight of (meth)acrylic acid and comonomers with aromatic groups during the copolymerization process.

[0029] In a preferred embodiment, the alkali-soluble resin has a weight-average molecular weight of 20,000–60,000, an acid value of 150–220 mg KOH / g, and a molecular weight distribution of 1.0–3.0. When the resin's weight-average molecular weight is less than 20,000, there is a tendency for decreased resistance to developer and easy overflow of the resist layer; when it exceeds 60,000, there is a tendency for decreased resolution. When the resin's molecular weight distribution exceeds 3.0, there is a risk of decreased resolution and elongated residual lines at the bottom of the resisted circuit.

[0030] In a preferred embodiment, the photopolymerization monomer is an olefinically unsaturated double-bonded monomer. For example, the photopolymerization monomer may be selected from one or more of the following: ethoxylated nonylphenol acrylate, propionylphenol acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated diacrylate, ethoxylated dimethacrylate, propionyl diacrylate, ethoxylated trimethylolpropane tri(meth)acrylate, or ethoxylated pentaerythritol tetraacrylate.

[0031] To improve the adhesion and resolution of dry film resist, the photopolymerizable monomer preferably contains bisphenol A di(meth)acrylate, such as 4-bisphenol A di(meth)acrylate or 10-bisphenol A di(meth)acrylate. To suppress the residual size of resist lines, the photopolymerizable monomer preferably contains trimethylolpropane tri(meth)acrylate, such as 3-trimethylolpropane triacrylate, 6-trimethylolpropane triacrylate, or 15-trimethylolpropane trimethacrylate. To improve stripping performance and developer dispersibility, the photopolymerizable monomer preferably contains nonylphenol acrylate, such as 4-nonylphenol acrylate or 8-nonylphenol acrylate. To improve product flexibility, the photopolymerizable monomer preferably contains dimethacrylate, such as 9-dimethacrylate. More preferably, the photopolymerizable monomer is selected from ethoxydimethacrylate, ethoxybisphenol A di(meth)acrylate, ethoxynonylphenol acrylate, and ethoxytrimethylolpropane trimethacrylate.

[0032] To further improve the resolution and photosensitivity of the product, a triarylimidazolium dimer derivative is preferred as the photoinitiator. Preferably, the photoinitiator is selected from one or more of 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazolium dimer, or 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole. 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer is further preferred.

[0033] In a preferred embodiment, the photosensitive resin composition further comprises 0.5 to 5.0 parts by weight of additives. The additives are selected from one or more of dyes, color-developing agents, antioxidants, plasticizers, defoamers, leveling agents, or polymerization inhibitors. For example, the dye is selected from one or more of malachite blue, diamond green, crystal violet, Victoria blue, basic blue 7, or basic blue 20; the color-developing agent is selected from one or more of tribromomethylphenyl sulfone, tris(2,3-dibromopropyl) phosphate, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and leuco crystal violet; the antioxidant is selected from tris(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) phosphite, bis(1,2,2,6,6-pentamethyl-4-hydroxypiperidine) sebacate, 2,2,6,6-tetramethylpiperidine-1-oxy radical, 4-oxo-2,2,6,6-tetramethyl-4-piperidine, and 2,2,6,6-tetramethyl methacrylate. One or more of -4-piperidinyl esters; plasticizers selected from one or more of o-toluenesulfonamide, p-toluenesulfonamide, tributyl citrate, and triethyl citrate; defoamers selected from one or more of polypropylene glycol, polypropylene glycol alkyl ethers, octamethylcyclotetrasiloxane, or tributyl phosphate; leveling agents selected from one or more of BYK-L9565, BYK-333, BYK-348, and BYK-306; polymerization inhibitors selected from one or more of p-tert-butylphenol, p-tert-butylcatechol, 2,6-di-tert-butyl-p-methylphenol, 2,6-di-tert-butyl-p-ethylphenol, 2,4,6-tri-tert-butylphenol, and 2-(2H-benzotriazol-2-yl)-cresol.

[0034] The present invention also provides a photosensitive dry film, comprising, from top to bottom, a PE film layer, a photoresist layer, and a PET film layer; wherein the photoresist layer is made of the aforementioned photosensitive resin composition. For the reasons stated above, the photosensitive dry film of the present invention exhibits excellent photosensitivity, resolution, and adhesion.

[0035] This invention also provides an application of the aforementioned photosensitive dry film in the manufacturing process of printed circuit boards, lead frames, or semiconductor packaging substrates. For the reasons stated above, the photosensitive dry film of this invention possesses excellent photosensitivity, resolution, and adhesion, and can therefore be widely used in the manufacturing processes of printed circuit boards (PCBs), lead frames (LFs), and semiconductor packaging (IC) substrates, improving production efficiency and yield.

[0036] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0037] (1) Synthesis of anthracene sensitizer compound 9,10-bis(4-hexylphenoxy)anthracene (D-1)

[0038] The raw materials 9,10-dibromoanthracene (Maclean), 4-hexylphenol (Maclean), and sodium methoxide were all purchased from the market.

[0039] Add 17.8 g (0.1 mol) of 4-hexylphenol and 150 mL of N,N-dimethylformamide to a 500 mL three-necked flask equipped with a stirrer, reflux condenser, and nitrogen protection. After dissolving, add 5.4 g (0.1 mol) of sodium methoxide. Stir at room temperature for 30 min, then add 13.4 g (0.04 mol) of 9,10-dibromoanthracene. After the addition is complete, place under nitrogen protection and heat to 100 °C for 4 h. TLC analysis of the sample showed that the reaction of the raw material 9,10-dibromoanthracene was basically complete. The reaction solution was cooled to room temperature and then slowly poured into 300 mL of room temperature water under stirring. Solids precipitated out. After sedimentation and filtration, the crude product was obtained. The crude product was dispersed in dichloromethane (20 mL). The resulting suspension was stirred at room temperature for 20 minutes, filtered, and the solids were collected. The solids were then dried under vacuum at 60 °C for 10 h to obtain product D-1 (17 g, purity 96%).

[0040] (2) Synthesis of anthracene sensitizer compound 9,10-bis(2,4-dimethylbenzoxy)anthracene (D-2)

[0041] The raw materials 9,10-anthraquinone (Maclean), 2,4-dimethylbenzyl bromide (Wuhan Debai Technology), sodium dithionate, and tetrabutylammonium bromide were all purchased from the market.

[0042] 9,10-anthraquinone (20.8 g, 0.1 mol), 2,4-dimethylbenzyl bromide (59.7 g, 0.3 mol), 50% (w / w) potassium hydroxide aqueous solution (67 g, 0.6 mol), sodium dithionate (35 g, 0.3 mol), toluene (150 g), and tetrabutylammonium bromide (0.3 g) were added to a 500 mL three-necked flask equipped with a stirrer, reflux cooling system, and nitrogen protection. After the addition was completed, the reaction solution was reacted at 90 °C for 3 h under nitrogen protection. TLC analysis of the sample showed that the reaction of the raw material 9,10-anthraquinone was basically complete. The reaction solution was cooled to room temperature, and water (300 mL) and toluene (300 mL) were added for extraction. The aqueous phase was extracted again with toluene (300 mL). The combined organic phases were washed with saturated brine and concentrated under reduced pressure to obtain the crude product. The crude product was dispersed in toluene (30 mL), and the resulting suspension was stirred at room temperature for 20 minutes. The suspension was filtered, the solid was collected, and the solid was dried under vacuum at 60 °C for 10 h to obtain product D-2 (22 g, purity 94%).

[0043] (3) Synthesis of anthracene sensitizer compound 9,10-bis(2-methylbenzoyloxy)anthracene (D-3)

[0044] The raw materials, anthracene-9,10-diol (Shanghai Jizhi Biochemical Technology) and o-methylbenzoic acid (Shanghai Titan), were both purchased from the market.

[0045] Add anthracene-9,10-diol (21.0 g, 0.1 mol), dichloromethane (150 mL), and N,N-diisopropylethylamine (25.2 g, 0.25 mol) to a 500 mL three-necked flask equipped with a stirrer, reflux cooling system, and nitrogen protection. After complete dissolution, cool the flask to 0-5 °C with ice water. Add o-methylbenzoyl chloride (33.8 g, 0.22 mol) dropwise over 1 hour. After the addition is complete, remove the ice bath and allow the mixture to react at room temperature for 6 hours. TLC analysis of the sample showed that the anthracene-9,10-diol reacted almost completely. Water (300 mL) and dichloromethane (300 mL) were added for extraction. The aqueous phase was extracted again with dichloromethane (300 mL). The combined organic phases were washed with saturated brine and concentrated under reduced pressure to obtain a crude product. The crude product was dispersed in dichloromethane (50 mL). The resulting suspension was stirred at room temperature for 20 minutes, filtered, and the solid was collected. The solid was dried under vacuum at 60 °C for 10 h to obtain product D-3 (37 g, purity 94%).

[0046] According to the formulations in Table 1 (Examples and Comparative Examples) below, the components were mixed in proportion, 60 parts by weight of acetone were added, and then the mixture was stirred thoroughly until completely dissolved to prepare a resin composition solution with a solid content of 40%. This solution was then uniformly coated onto the surface of a 15 μm thick PET support film using a coating machine and baked in a 95°C oven for 6 minutes to form a 25 μm thick photoresist layer, which appeared blue-green under yellow light. Then, a 20 μm thick polyethylene film (PE) protective layer was laminated onto the surface of the photoresist layer to obtain a three-layer photosensitive dry film.

[0047] The alkali-soluble resins in Table 1 are prepared using solution polymerization:

[0048] A-1: The main components are methacrylic acid / butyl methacrylate / o-phenylphenoxyethyl acrylate / styrene = 31 / 7 / 12 / 50 (weight average molecular weight 27,000, acid value 202.2 mgKOH / g, molecular weight distribution 1.9);

[0049] A-2: The main components are methacrylic acid / methyl methacrylate / benzyl methacrylate / styrene = 25 / 20 / 10 / 45 (weight average molecular weight 54,000, acid value 163.1 mgKOH / g, molecular weight distribution 2.2);

[0050] A-3: The main components are methacrylic acid / methyl methacrylate / benzyl methacrylate / styrene = 25 / 35 / 12 / 28 (weight average molecular weight 42,000, acid value 163.1 mgKOH / g, molecular weight distribution 2.1);

[0051] A-4: The main components are methacrylic acid / benzyl methacrylate / styrene = 26 / 24 / 50 (weight average molecular weight 38,000, acid value 169.6 mgKOH / g, molecular weight distribution 2.3).

[0052] Photopolymerizable monomers:

[0053] B-1: 4-Ethylene oxide bisphenol A di(meth)acrylate, molecular weight 540 (Meiyuan Chemical)

[0054] B-2: 10-Ethylene oxide bisphenol A di(meth)acrylate, molecular weight 804 (Meiyuan Chemical)

[0055] B-3: 9-Ethoxydimethacrylate, molecular weight 598 (Sartoma)

[0056] B-4: 8-Ethoxynonylphenol acrylate, molecular weight 450 (Meiyuan Chemical)

[0057] B-5: 15-Ethylenetrimethylolpropanetrimethacrylate, molecular weight 998 (Sartoma)

[0058] Photoinitiator:

[0059] C-1: 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer (Changzhou Qiangli Electronic Materials)

[0060] Sensitizer:

[0061] D-1: 9,10-Di(4-hexylphenoxy)anthracene

[0062] D-2: 9,10-bis(2,4-dimethylbenzoxy)anthracene

[0063] D-3: 9,10-Di(2-methylbenzoyloxy)anthracene

[0064] D-4: 9,10-Diphenylanthracene (Shanghai Diweigao)

[0065] D-5: 9,10-Dibutoxyanthracene (Shanghai Diweigao)

[0066] additive:

[0067] E-1 (Dye): Malachite Green (Shanghai Bailingwei Chemical Technology Co., Ltd.)

[0068] E-2 (Color developer): Leuco crystal violet (Shanghai Bailingwei Chemical Technology Co., Ltd.)

[0069] E-3 (Antioxidant): 2,2,6,6-Tetramethyl-4-piperidinyl methacrylate (Shanghai Yuanye Biotechnology Co., Ltd.) E-4 (Plasticizer): p-Toluenesulfonamide (Shanghai Tixi'ai Chemical)

[0070] Table 1

[0071]

[0072]

[0073] The following describes the sample preparation methods (including film application, exposure, development, and film removal) of the embodiments and comparative examples, the sample evaluation methods, and the evaluation results.

[0074] [Screen protector]

[0075] The copper-clad laminate is polished using a grinding machine, washed with water, and dried to obtain a bright and fresh copper surface. The laminating machine is set with a pressure roller temperature of 110℃, a conveying speed of 1.5m / min, and heat lamination under standard pressure.

[0076]

exposure

[0077] After applying the film, let the sample stand for more than 15 minutes, then expose it using an Adtec IP-6 exposure machine with 13-17 exposure frames.

[0078]

development

[0079] After exposure, the sample should be allowed to stand for at least 15 minutes. The development temperature is 30℃, and the pressure is 1.2 kg / cm². 2 The developer is a 1% wt sodium carbonate aqueous solution, and the development time is 1.5-2.0 times the minimum development time. After development, the sample is washed with water and dried. The minimum development time is defined as the time required for the unexposed resist layer to just completely dissolve in the developing tank.

[0080] Evaluation of photosensitivity

[0081] After the film was applied, the sample was allowed to stand for at least 15 minutes, then exposed using an Adtec IP-6 exposure machine. Sensitivity was measured using a Stovffer 41-step exposure scale. After exposure, the sample was allowed to stand for at least 15 minutes, then sprayed with a 1 wt% sodium carbonate aqueous solution at 30°C. The development time was 2.0 times the minimum development time, thus removing unexposed areas. Following this process, a cured film of the photosensitive resin composition was formed on the copper surface of the substrate. The exposure amount (mJ / cm²) was measured when the number of remaining segments on the staged exposure scale obtained as the cured film reached 15. 2The photosensitivity of the photosensitive resin composition was evaluated. The smaller the value, the better the photosensitivity.

[0082] Judgment criteria: ○: 20-40mJ / cm 2

[0083] △: 40-55mJ / cm 2

[0084] ×:>55mJ / cm 2

[0085] [Resolution Evaluation]

[0086] Exposure is performed using a mask with a wiring pattern having an exposed portion and an unexposed portion with a width of n:n (n being 5–25 μm). After development at 2.0 times the minimum development time, the minimum mask width at which the cured resist lines normally form is taken as the resolution value, and observed using a magnifying glass. The smaller the number read, the better the resolution.

[0087] [Evaluation of Adhesion]

[0088] Photosensitive dry film resist is laminated onto a copper plate using a hot-pressing method. A mask with a wiring pattern having an exposed and unexposed portion and a width of n:400 (n being 5–25 μm) is used for exposure. After development at 2.0 times the minimum development time, the minimum mask width at which the cured resist lines normally form is taken as the adhesion value, and observed using a magnifying glass. The smaller the number read, the better the adhesion.

[0089] [Evaluation of film removal speed]

[0090] Take a substrate that has been laminated, exposed, and developed, cut it into a 4×5cm square, and place it in a beaker containing 100mL of stripping solution (methylethanolamine concentration 3wt%, temperature 50℃). Stir magnetically and record the time it takes for the dry film to completely peel off. The stripping speed is evaluated by testing the stripping time; the shorter the stripping time, the faster the stripping speed.

[0091] [Evaluation of Sensitizer Migration]

[0092] After placing the prepared three-layer photosensitive dry film at 30°C for 48 hours, the UV absorption spectrum of the dry film was detected using a UV spectrophotometer, obtaining the absorbance A1 of the maximum absorption peak in the 350-450 nm range. The PE film layer on the surface of the photosensitive dry film was removed, and the UV absorption spectra of the PET layer and the photoresist layer were detected using a UV spectrophotometer, obtaining the absorbance A2 of the maximum absorption peak in the 350-450 nm range. If the sensitizer migrates to the PE layer surface, the absorbance of the maximum absorption peak in the 350-450 nm range of the PET layer and the photoresist layer will decrease; that is, the absorbance of the sensitizer that migrated to the PE layer is (A1-A2). The degree of sensitizer migration is calculated, i.e., the migration rate A = (A1-A2) / A1; a larger value indicates a greater migration amount.

[0093] Basis for judgment:

[0094] ○: Mobility A < 0.01; ×: Mobility A > 0.01.

[0095] [Evaluation of Sensitizer Dissolution Rate]

[0096] Weigh 0.5 g of anthracene sensitizer solid compound into a transparent glass bottle, add 10 g of acetone, and place the bottle in a 30°C water bath. Observe and record the time required for the solid to completely dissolve from the time it is placed in the water bath. The shorter the time, the faster the dissolution rate.

[0097] Basis for judgment:

[0098] ○: Dissolves completely within 2 hours;

[0099] △: Dissolves completely within 2-3 hours;

[0100] ×: Completely dissolved in more than 3 hours.

[0101] Table 2

[0102]

[0103] A comparison of Examples 1-6 with Comparative Examples 1-4 reveals that Examples 1-6 yielded photosensitive resin compositions exhibiting excellent performance in terms of photosensitivity, resolution, adhesion, and the migration and dissolution rates of the sensitizer. The 9,10-diphenylanthracene used in Comparative Example 1 had an insufficient dissolution rate, easily leading to prolonged production time or filter clogging due to incomplete sensitizer dissolution, resulting in decreased photosensitivity. Comparative Example 2 added 9,10-dibutoxyanthracene, anthracene sensitizers that easily migrate and precipitate from the polyethylene film (PE), causing a decrease in photosensitivity and yield. Comparative Example 3 added an excessive amount of anthracene sensitizer, resulting in excellent photosensitivity but decreased adhesion and resolution. Comparative Example 4 did not add any anthracene sensitizer, resulting in insufficient photosensitivity and resolution.

[0104] Furthermore, in Example 7, the copolymerization ratio of aromatic copolymer units in the alkali-soluble resin is less than 50% of the total mass of all monomers, resulting in insufficient adhesion and resolution. In Example 8, the copolymerization ratio of aromatic copolymer units in the alkali-soluble resin is greater than 70% of the total mass of all monomers, resulting in excellent adhesion and resolution. However, the film removal time is relatively long, which can easily cause problems such as film removal residue, affecting the yield.

[0105] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A photosensitive resin composition, characterized in that, The photosensitive resin composition comprises, by weight, 45-60 parts of an alkali-soluble resin, 35-50 parts of a photopolymerizable monomer, 2.5-5 parts of a photoinitiator, and 0.1-0.8 parts of a sensitizer; the sensitizer is a compound represented by the following general formula I: General Formula I In the general formula I, R1 represents methylene or carbonyl, n represents 0 or 1; R2 represents phenyl, and any hydrogen atom on R2 may optionally be replaced by a methoxy group, C1-C12, or C1-C12. 10 Substituted with straight-chain or branched alkyl groups; The alkali-soluble resin is obtained by copolymerization of (meth)acrylic acid monomer and comonomer having aromatic groups; or the alkali-soluble resin is obtained by copolymerization of (meth)acrylic acid monomer, (meth)acrylic acid alkyl ester monomer and comonomer having aromatic groups. Based on the total weight of the comonomers during the copolymerization process, the copolymerization ratio of the comonomers having aromatic groups is between 50% and 70%.

2. The photosensitive resin composition according to claim 1, characterized in that, The sensitizer is selected from 9,10-diphenoxyanthracene, 9,10-di(2-methylphenoxy)anthracene, 9,10-di(2-methoxyphenoxy)anthracene, 9,10-di(3-methylphenoxy)anthracene, 9,10-di(4-ethylphenoxy)anthracene, 9,10-di(4-propylphenoxy)anthracene, 9,10-di(4-butylphenoxy)anthracene, 9,10-di(4-tert-butylphenoxy)anthracene, 9,10-di(4-pentylphenoxy)anthracene, 9,10-di(4-hexylphenoxy)anthracene, 9,10-di(4-nonylphenoxy)anthracene, 9,10-di(benzylmethoxy)anthracene, 9,10-di(2-methylbenzylmethoxy)anthracene. One or more of the following: 9,10-bis(3-methylbenzoxy)anthracene, 9,10-bis(2,3-dimethylbenzoxy)anthracene, 9,10-bis(2,4-dimethylbenzoxy)anthracene, 9,10-bis(2,3,4,5,6-pentamethylbenzoxy)anthracene, 9,10-bis(benzoyloxy)anthracene, 9,10-bis(2-methylbenzoyloxy)anthracene, 9,10-bis(3-methylbenzoyloxy)anthracene, 9,10-bis(4-methylbenzoyloxy)anthracene, 9,10-bis(3,5-dimethylbenzoyloxy)anthracene, 9,10-bis(4-butylbenzoyloxy)anthracene, or 9,10-bis(4-hexylbenzoyloxy)anthracene.

3. The photosensitive resin composition according to claim 2, characterized in that, The sensitizer is selected from one or more of 9,10-bis(4-hexylphenoxy)anthracene, 9,10-bis(2,4-dimethylbenzoxy)anthracene or 9,10-bis(2-methylbenzoyloxy)anthracene.

4. The photosensitive resin composition according to claim 1, characterized in that, The comonomer having an aromatic group is selected from one or more of phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, styrene, or o-phenylphenoxyethyl acrylate; And / or, the alkyl methacrylate monomers are selected from butyl methacrylate and / or methyl methacrylate.

5. The photosensitive resin composition according to claim 4, characterized in that, The comonomer having an aromatic group is selected from one or more of benzyl methacrylate, styrene, and o-phenylphenoxyethyl acrylate.

6. The photosensitive resin composition according to claim 1, characterized in that, The alkali-soluble resin has a weight-average molecular weight of 20,000 to 60,000, an acid value of 150 to 220 mg KOH / g, and a molecular weight distribution of 1.0 to 3.

0.

7. The photosensitive resin composition according to any one of claims 1 to 6, characterized in that, The photopolymerizable monomer is an olefinic unsaturated double bond monomer.

8. The photosensitive resin composition according to claim 7, characterized in that, The photopolymerizable monomer is selected from one or more of the following: ethoxylated nonylphenol acrylate, propionylphenol acrylate, ethoxylated bisphenol A di(meth)acrylate, ethoxylated diacrylate, ethoxylated dimethacrylate, propionyl diacrylate, ethoxylated trimethylolpropane tri(meth)acrylate, or ethoxylated pentaerythritol tetraacrylate.

9. The photosensitive resin composition according to claim 8, characterized in that, The photopolymerizable monomers are selected from ethoxydimethyl acrylate, ethoxybisphenol A di(meth) acrylate, ethoxynonylphenol acrylate, and ethoxytrimethylolpropane trimethyl acrylate.

10. The photosensitive resin composition according to any one of claims 1 to 6, characterized in that, The photoinitiator is a triarylimidazolium dimer derivative.

11. The photosensitive resin composition according to claim 10, characterized in that, The photoinitiator is selected from one or more of 2-(o-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazolium dimer, or 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

12. The photosensitive resin composition according to any one of claims 1 to 6, characterized in that, The photosensitive resin composition further includes 0.5 to 5.0 parts by weight of additives.

13. The photosensitive resin composition according to claim 12, characterized in that, The additive is selected from one or more of dyes, colorants, antioxidants, plasticizers, defoamers, leveling agents, or polymerization inhibitors.

14. A photosensitive dry film, characterized in that, The photosensitive dry film comprises a PE film layer, a photosensitive resist layer, and a PET film layer arranged sequentially from top to bottom; wherein the material of the photosensitive resist layer is the photosensitive resin composition according to any one of claims 1 to 13.

15. The use of the photosensitive dry film of claim 14 in the manufacturing process of printed circuit boards, lead frames, or semiconductor packaging substrates.

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