Photosensitive resin composition, photosensitive film and application thereof

Abstract

The invention provides a photosensitive resin composition, a photosensitive film and application thereof. The photosensitive resin composition comprises the following components: a benzocyclobutene grafted butadiene polymer, a photoinitiator and an organic solvent, in the benzocyclobutene grafted butadiene polymer, the molar content of-CH = CH2 groups is greater than 50% when the total molar number of-CH = CH2 groups and benzocyclobutene groups is 100%. In the benzocyclobutene grafted butadiene polymer, the content of vinyl functional groups is higher than that of benzocyclobutene functional groups, and patterns with high resolution and good line quality can be prepared. Meanwhile, benzocyclobutene and vinyl which is not photocured can be crosslinked in the subsequent thermocuring step, and therefore it is guaranteed that the prepared photosensitive film has excellent heat resistance. In addition, the subsequent thermocuring conditions of the photosensitive resin composition provided by the invention are relatively simple.

Description

Technical Field

[0001] The present invention belongs to the technical field of photolithography patterning materials, and relates to a photosensitive resin composition, a photosensitive film and applications thereof, and in particular to a low dielectric loss photosensitive resin composition, a photosensitive film and applications thereof in photolithography patterning. Background Art

[0002] The integrated circuit material industry is the foundation for the development of the integrated circuit industry, and the quality of materials directly affects the performance of integrated circuit products. With the rapid development of the microelectronics industry, the corresponding electronic devices and integrated circuits are moving towards miniaturization, high speed, and high density, requiring dielectric materials with lower dielectric constants and loss factors to accommodate more metal wires at narrower intervals.

[0003] UV curing technology is low-cost and environmentally friendly, and can cure to form a three-dimensional network structure in a short time. The core of UV curing is photoresist. In the manufacturing process of integrated circuits, photochemical reactions occur in the exposed area of ​​the photoresist, resulting in solubility differences between the exposed area and the non-exposed area in the developer. The resulting photolithography pattern can be used as a dielectric insulating layer for integrated circuits. Organic polymer materials exhibit excellent performance due to their structural characteristics. Since the lateral diffusion of macromolecules is suppressed, the patterns of polymers usually have higher resolution.

[0004] Benzocyclobutene (BCB) groups can be cross-linked and cured by heating, without producing small molecules, and have little effect on the performance of the resin. Photosensitive resins prepared with benzocyclobutene as the substrate have the advantages of low dielectric constant, low dielectric loss, low moisture absorption rate, and high thermal stability, and have important application value in microelectronic packaging. On the other hand, low dielectric loss photosensitive resins have the advantages of low chemical polarity and low polarizability under external electric field conditions, which is conducive to reducing the dielectric constant.

[0005] Burgoon et al. obtained two all-hydrocarbon resins with vinyl double bonds in the side chains by co-olefin exchange reaction of 5-butenyl-2-norbornene itself or with 5-decyl-2-norbornene (ACS Applied Polymer Materials, 2020, 2 (5), 1819-1826). The photocrosslinker 2,6-bis-(4-azidobenzylidene)-4-ethylcyclohexanone and solvent were added to the two polymers to prepare a photosensitive solution, and then the photosensitive solution was spin-coated to form a photosensitive film. The film under the mask was irradiated with ultraviolet light, and a pattern with a minimum feature size of 5 microns was obtained after development. However, the thermal stability of the photosensitive resin is low, and it is difficult to meet the high heat resistance requirements in the process of electronic device manufacturing.

[0006] CYCLOTENE 4000 Series photosensitive resin developed by DOW Chemical Company has good comprehensive properties, but it contains Si-O bonds with high polarity, which results in high dielectric constant (Dk: 2.65) and dielectric loss (D f :0.005-0.008), which limits its application in high frequency fields.

[0007] CN115826359A discloses the preparation and application of a full carbon hydrogen low dielectric loss photosensitive resin for photolithography patterning, D f It can reach 0.001-0.002. However, the proportion of C=C double bonds that can undergo photocuring in the resin composition is relatively low, and the proportion of pure thermosetting benzocyclobutene is relatively high, resulting in a low degree of curing during the photocuring process, which leads to the need for more stringent conditions for the subsequent BCB during the thermal curing process.

[0008] Therefore, in the art, it is desired to develop a photosensitive resin composition, the thermal curing conditions of which are simple, and the photosensitive film prepared therefrom has excellent dielectric properties, mechanical properties and heat resistance. Summary of the invention

[0009] In view of the deficiencies in the prior art, the object of the present invention is to provide a photosensitive resin composition, a photosensitive film and applications thereof, and in particular to provide a low dielectric loss photosensitive resin composition, a photosensitive film and applications thereof in photolithography patterning.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a photosensitive resin composition, the photosensitive resin composition comprising the following components: a benzocyclobutene-grafted butadiene polymer, a photoinitiator and an organic solvent;

[0012] In the benzocyclobutene-grafted butadiene polymer, based on the total molar number of -CH=CH2 groups and benzocyclobutene groups as 100%, the molar content of -CH=CH2 groups is greater than 50%, for example, 51%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0013] It should be noted that the molar content of -CH=CH2 groups (or vinyl groups) mentioned below in the present invention is based on the total molar number of -CH=CH2 groups and benzocyclobutene groups, and will not be repeated one by one.

[0014] The benzocyclobutene-grafted butadiene polymer of the present invention has a fully hydrocarbon structure, and the organic dielectric material prepared by photo-curing + thermal curing has better dielectric properties.

[0015] In the benzocyclobutene-grafted butadiene polymer of the present invention, based on the total molar amount of -CH=CH2 groups and benzocyclobutene groups being 100%, the molar content of -CH=CH2 groups is greater than 50%, that is, the content of vinyl functional groups in the molecular structure of the benzocyclobutene-grafted butadiene polymer is higher than that of benzocyclobutene functional groups. In the developing step, it has a certain crosslinking density (the vinyl groups can be fully crosslinked or partially crosslinked), and at the same time, the undeveloped part is soluble in the developer, and a pattern with high resolution and good line quality can be prepared. At the same time, the benzocyclobutene in the structure and the possibly existing un-photo-cured vinyl groups can be crosslinked in the subsequent thermal curing step, thereby ensuring that the prepared photosensitive film has excellent heat resistance. Moreover, the conditions for subsequent thermal curing of the photosensitive resin composition provided by the present invention are relatively simple.

[0016] The photosensitive resin composition provided by the present invention has excellent dielectric properties, mechanical properties, heat resistance and chemical stability, and is expected to be applied in the microelectronics field.

[0017] Preferably, in the benzocyclobutene-grafted butadiene polymer, based on the total molar amount of -CH=CH2 groups and benzocyclobutene groups being 100%, the molar content of -CH=CH2 groups is 60-95%, and further preferably 70-90%.

[0018] Preferably, the benzocyclobutene-grafted butadiene polymer comprises at least one structural unit A and at least one structural unit B;

[0019] The structural unit A has the structure shown in Formula I:

[0020]

[0021] R1 is vinylene and / or ethylene;

[0022] The structural unit B has the structure shown in Formula II:

[0023]

[0024] R2 is vinyl, ethyl and / or phenyl, and at least one R2 on the structural unit B is vinyl.

[0025] In the benzocyclobutene-grafted butadiene polymer provided by the present invention, the side chain of the structural unit A contains a benzocyclobutyl structure, and the structural unit B is any one or a combination of at least two of polybutadiene, polyhydrogenated butadiene structure, and polystyrene structure; the benzocyclobutene-grafted butadiene polymer is a fully hydrocarbon structure, having a low dielectric constant Dk and a low dielectric loss tangent Df; at the same time, the molecular structure contains reactive vinyl groups, which can participate in both photocuring and thermal curing.

[0026] Preferably, the benzocyclobutene-grafted butadiene polymer contains a structural unit A1, which has the structure shown in formula IA, and the molecular structure contains reactive vinylidene groups, and has a high crosslinking efficiency in the thermal curing reaction:

[0027]

[0028] Preferably, the benzocyclobutene-grafted butadiene polymer contains a structural unit A2, which has the structure shown in formula IB:

[0029]

[0030] Optionally, the structural unit A2 can be obtained by hydrogenating the structural unit A1, and its molecular structure contains a saturated carbon chain with low dielectric loss.

[0031] Preferably, the benzocyclobutene-grafted butadiene polymer contains a structural unit B1, which has the structure shown in formula IIA:

[0032]

[0033] Preferably, the benzocyclobutene-grafted butadiene polymer contains a structural unit B2, which has the structure shown in formula IIB:

[0034]

[0035] Preferably, the benzocyclobutene-grafted butadiene polymer contains a structural unit B3, which has the structure shown in formula IIC, and its side chain contains a phenyl group, and has good compatibility with other resins:

[0036]

[0037] Optionally, the structural unit B2 can be obtained by hydrogenating the structural unit B1, and it contains a saturated alkyl structural unit with low dielectric loss.

[0038] Preferably, the benzocyclobutene-grafted butadiene polymer may solely contain structural unit B1, or may simultaneously contain structural units B1 and B2, or may simultaneously contain structural units B1 and B3, or may simultaneously contain structural units B1, B2 and B3.

[0039] Preferably, the benzocyclobutene-grafted butadiene polymer further contains structural unit C, and the structural unit C has the structures shown in formula IIIA and / or formula IIIB:

[0040]

[0041] It should be noted that the benzocyclobutene-grafted butadiene polymer in the present invention is a polymer chain segment structure, including at least one (preferably multiple) structural unit A, at least one (preferably multiple) structural unit B, and optionally structural unit C; the present invention does not limit the connection order of the above structural units, and any connection order / connection method feasible in chemistry is within the scope of the present invention.

[0042] Preferably, the molar percentage content of structural unit C in the benzocyclobutene-grafted butadiene polymer is ≤40%, for example, it can be 0, 1%, 3%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35% or 40%, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is ≤30%, more preferably ≤20%, and most preferably ≤10%; thereby, the curing degree of the benzocyclobutene-grafted butadiene polymer can be increased, and it has a higher glass transition temperature.

[0043] Exemplarily, the preparation method of the benzocyclobutene-grafted butadiene polymer includes: coupling reaction of polybutadiene with 4-halobenzocyclobutene to obtain the benzocyclobutene-grafted butadiene polymer; the polybutadiene contains 1,2-polymerized structural units Hal is a halogen, for example, it can be Cl, Br or I.

[0044] Preferably, the Hal is Br, that is, the raw material is 4-bromobenzocyclobutene

[0045] Preferably, the coupling reaction is carried out in the presence of a palladium catalyst system.

[0046] Preferably, the palladium catalyst system includes a palladium catalyst and an organic phosphine ligand.

[0047] Preferably, the palladium catalyst is palladium acetate, and the organic phosphine ligand is tris(ortho-methylphenyl)phosphine.

[0048] Preferably, the coupling reaction is carried out in the presence of an acid-binding agent.

[0049] Preferably, the acid-binding agent includes an organic base, more preferably triethylamine.

[0050] Preferably, the coupling reaction is carried out in an inert protective atmosphere, and the inert protective atmosphere includes any one of a nitrogen atmosphere, an argon atmosphere, and a helium atmosphere.

[0051] Preferably, the temperature of the coupling reaction is 60-100 °C. For example, it can be 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C or 95 °C, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0052] Preferably, the time of the coupling reaction is 5-36 h. For example, it can be 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 24 h, 28 h, 32 h or 34 h, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0053] Preferably, the photoinitiator includes any one or a combination of at least two of 1-hydroxy-cyclohexyl-phenyl ketone, 2,6-bis(4-azobenzylidene)cyclohexanone, 3,3'-carbonylbis(7-diethylaminocoumarin), benzophenone or diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide.

[0054] Preferably, based on 100 parts by mass of the organic components in the photosensitive resin composition, the amount of the photoinitiator used is 1-10 parts. For example, it can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0055] It should be noted that in the present invention, the organic components in the photosensitive resin composition refer to the benzocyclobutene-grafted butadiene polymer and other resins that may be included (such as the thermoplastic resin described later).

[0056] Preferably, the organic solvent includes any one or a combination of at least two of toluene, xylene, chloroform, dichloromethane, n-hexane, ethyl acetate, butyl acetate, petroleum ether, cyclohexanone or cyclohexane.

[0057] Preferably, the amount of the organic solvent is such that the solid content of the adhesive liquid in the photosensitive resin composition is 60-70%, for example, it can be 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68% or 69%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0058] Preferably, the photosensitive resin composition further comprises a thermoplastic resin.

[0059] Preferably, based on the total weight of the photosensitive resin composition being 100%, the mass percentage content of the thermoplastic resin ≤ 80%, for example, it can be 0, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70% or 75%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0060] Preferably, the thermoplastic resin comprises a hydrogenated styrene-butadiene block copolymer (SEBS) and / or a polyphenylene oxide (PPO).

[0061] Preferably, the hydrogenated styrene-butadiene block copolymer comprises unmodified SEBS and / or modified SEBS.

[0062] Preferably, the modified SEBS comprises any one or a combination of at least two of maleic anhydride-modified SEBS, epoxy-modified SEBS, amino-modified SEBS, and carboxyl-modified SEBS.

[0063] Preferably, the photosensitive resin composition further comprises a filler.

[0064] Preferably, based on the mass of the organic components in the photosensitive resin composition being 100 parts, the mass of the filler is 5-40 parts, for example, it can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts or 35 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range, preferably 10-30 parts, more preferably 10-25 parts.

[0065] Preferably, the filler is an inorganic filler and / or an organic filler, more preferably an inorganic filler.

[0066] Preferably, the inorganic filler comprises any one or a combination of at least two of silica, aluminum hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate, and mica.

[0067] Preferably, the organic filler includes any one or a combination of at least two of polyphenylene ether fillers (powder and / or microspheres), polytetrafluoroethylene fillers (powder), polyetheretherketone fillers, polyphenylene sulfide fillers, and polyethersulfone fillers (powder).

[0068] Preferably, the median particle size (D50) of the filler is 30 - 500 nm, for example, it can be 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, or 450 nm, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Preferably, it is 50 - 500 nm, and more preferably 50 - 300 nm.

[0069] Exemplarily, the particle size of the filler is measured by an MS3000 Malvern laser particle size analyzer.

[0070] Preferably, the filler includes a surface-treated filler.

[0071] Preferably, the surface treatment agent for the surface treatment includes any one or a combination of at least two of silane coupling agents, organosilicon oligomers, and titanate coupling agents.

[0072] Preferably, based on 100 parts by mass of the filler to be treated, the mass of the surface treatment agent is 0.1 - 5 parts, for example, 0.2 parts, 0.5 parts, 0.8 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, or 4.5 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. More preferably, it is 0.5 - 3 parts, and even more preferably 0.75 - 2 parts.

[0073] Preferably, the photosensitive resin composition further includes a flame retardant.

[0074] Preferably, based on 100 parts by mass of the resin in the photosensitive resin composition, the mass of the flame retardant is 1 - 50 parts, for example, it can be 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, or 45 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0075] Preferably, the flame retardant includes a halogen-containing flame retardant and a halogen-free flame retardant.

[0076] Preferably, the halogen-containing flame retardant includes any one or a combination of at least two of decabromodiphenylethane, brominated polystyrene, polybrominated polystyrene, brominated polyphenylene ether, and ethylene bis(tetrabromophthalimide).

[0077] Preferably, the halogen-free flame retardant includes any one or a combination of at least two of phosphazene flame retardants, DOPO flame retardants, phosphonate flame retardants, and organic hypophosphite flame retardants.

[0078] The photosensitive resin composition provided by the present invention is prepared by the following method, and the preparation method includes: mixing and dispersing each component in the photosensitive resin composition uniformly to obtain the photosensitive resin composition.

[0079] Preferably, the preparation process of the photosensitive resin composition is carried out in the dark.

[0080] In a second aspect, the present invention provides a photosensitive film, and the material of the photosensitive film includes the photosensitive resin composition as described in the first aspect.

[0081] Preferably, the photosensitive film is prepared by coating the photosensitive resin composition on a release material (such as a PET release film, a PI release film, a PFA release film) and drying.

[0082] Preferably, the thickness of the photosensitive film is 5 - 50 μm, such as 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 48 μm, and specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the range.

[0083] In a third aspect, the present invention provides a multilayer printed circuit board, and the multilayer printed circuit board contains an interlayer insulating layer, and the interlayer insulating layer is formed by using the photosensitive film as described in the second aspect.

[0084] In a fourth aspect, the present invention provides a method for preparing a multilayer printed circuit board, and the preparation method has the following processes (1) - (3):

[0085] Process (1): A process of laminating the photosensitive film as described in the second aspect on one side or both sides of a circuit board by a vacuum laminator;

[0086] Process (2): A process of exposing and developing the photosensitive film in the process (1) to form an interlayer insulating layer with through holes;

[0087] Process (3): A process of forming a circuit pattern on the interlayer insulating layer.

[0088] Preferably, between process (2) and process (3), there is also a process (2 - 1): a heat treatment process for the interlayer insulating layer;

[0089] Preferably, between process (2) and process (3), there is also included process (2-2): a process of roughening the through holes and the interlayer insulating layer.

[0090] Preferably, the exposure and development in process (2) are specifically carried out by using a UV-LED light source to expose the photosensitive thin film through a photomask. The exposed area crosslinks and cures and is insoluble in the developer, while the unexposed area is soluble in the developer. After development with the developer, a pattern consistent with the photomask is obtained. The developer for the development includes any one or a combination of at least two of toluene, xylene, chloroform, n-hexane, cyclohexane, butyl acetate, ethyl acetate, and petroleum ether, preferably toluene, xylene, and cyclohexane.

[0091] Preferably, the wavelength of the UV-LED light source is 300-400 nm. For example, it can be 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 365 nm, 370 nm, 380 nm, 390 nm, or 400 nm, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0092] Preferably, the temperature of the heat treatment in process (2-1) is 190-230 °C. For example, it can be 195 °C, 200 °C, 205 °C, 210 °C, 215 °C, 220 °C, or 225 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range. The time of the heat treatment is 30-300 min. For example, it can be 40 min, 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, 240 min, or 270 min, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0093] Compared with the prior art, the present invention has at least the following beneficial effects:

[0094] (1) The benzocyclobutene-grafted butadiene polymer of the present invention has an all-carbon-hydrogen structure, and the organic dielectric material prepared by photo-curing + heat-curing has better dielectric properties.

[0095] (2) In the benzocyclobutene-grafted butadiene polymer of the present invention, based on the total molar amount of -CH=CH2 groups and benzocyclobutene groups being 100%, the molar content of -CH=CH2 groups is greater than 50%, that is, the content of vinyl functional groups in the molecular structure of the benzocyclobutene-grafted butadiene polymer is higher than that of benzocyclobutene functional groups. During the development step, it has a certain crosslinking density (the vinyl groups can be completely crosslinked or partially crosslinked), and at the same time, the undeveloped part is soluble in the developer, so that a pattern with high resolution and good line quality can be prepared. At the same time, the benzocyclobutene in the structure and the possibly existing un-photocured vinyl groups can be crosslinked in the subsequent thermal curing step, thereby ensuring that the prepared photosensitive film has excellent heat resistance. Moreover, the conditions for the subsequent thermal curing of the photosensitive resin composition provided by the present invention are relatively simple. Detailed implementation manners

[0096] The technical solutions of the present invention will be further described below through specific implementation manners. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0097] In the following specific implementation manners of the present invention, the specific information of the resin used to prepare the benzocyclobutene-grafted butadiene polymer is as follows:

[0098] B1000: Polybutadiene, the molar percentage content of the structural unit formed by 1,2-polymerization of butadiene ( the same below) is 85%, and the molar percentage content of the structural unit formed by 1,4-polymerization ( the same below) is 15%, Nippon Soda Co., Ltd.;

[0099] B2000: Polybutadiene, the molar percentage content of the structural unit formed by 1,2-polymerization is 88%, and the molar percentage content of the structural unit formed by 1,4-polymerization is 12%, Nippon Soda Co., Ltd.;

[0100] B3000: Polybutadiene, the molar percentage content of the structural unit formed by 1,2-polymerization is 92%, and the molar percentage content of the structural unit formed by 1,4-polymerization is 8%, Nippon Soda Co., Ltd.;

[0101] Ricon 154: Polybutadiene, the molar percentage content of the structural unit formed by 1,2-polymerization is 90%, and the molar percentage content of the structural unit formed by 1,4-polymerization is 10%, Sartomer Company, USA.

[0102] Preparation Example 1

[0103] A benzocyclobutene-grafted butadiene polymer CH-BCB1, and its preparation method is as follows:

[0104] Add 200 g of 4-bromobenzocyclobutene, 100 g of polybutadiene B1000, 19.29 g of tris(o-tolyl)phosphine, 8.83 g of palladium acetate, 655 mL of triethylamine and 2000 mL of acetonitrile into a flask, and stir at 85 °C for 24 hours under an argon atmosphere. Cool down and rotary evaporate the solvent. Perform a quick column chromatography with neutral alumina, rotary evaporate the solvent to obtain a viscous liquid. After dissolving it in toluene, add methanol with a volume four times that of toluene, shake well and let it stand, then separate the toluene layer. Then rotary evaporate and concentrate, and dry under vacuum to obtain a colorless viscous liquid, namely benzocyclobutene-grafted butadiene polymer CH-BCB1, whose vinyl molar content is 59% and number-average molecular weight is 2120.

[0105] Preparation Example 2

[0106] A benzocyclobutene-grafted butadiene polymer CH-BCB2, and its preparation method is as follows:

[0107] Add 170 g of 4-bromobenzocyclobutene, 100 g of polybutadiene B2000, 16.35 g of tris(o-tolyl)phosphine, 7.48 g of palladium acetate, 500 mL of triethylamine and 1500 mL of acetonitrile into a flask, and stir at 85 °C for 24 hours under an argon atmosphere. Cool down and rotary evaporate the solvent. Perform a quick column chromatography with neutral alumina, rotary evaporate the solvent to obtain a viscous liquid. After dissolving it in toluene, add methanol with a volume four times that of toluene, shake well and let it stand, then separate the toluene layer. Then rotary evaporate and concentrate, and dry under vacuum to obtain a colorless viscous liquid, namely benzocyclobutene-grafted butadiene polymer CH-BCB2, whose vinyl molar content is 63.7% and number-average molecular weight is 3900.

[0108] Preparation Example 3

[0109] A benzocyclobutene-grafted butadiene polymer CH-BCB3, and its preparation method is as follows:

[0110] Add 300 g of 4-bromobenzocyclobutene, 100 g of polybutadiene B3000, 30 g of tris(o-tolyl)phosphine, 13.74 g of palladium acetate, 1000 mL of triethylamine and 3000 mL of acetonitrile into a flask, and stir at 85 °C for 24 hours under an argon atmosphere. Cool down and rotary evaporate the solvent. Perform a quick column chromatography with neutral alumina, rotary evaporate the solvent to obtain a viscous liquid. After dissolving it in toluene, add methanol with a volume four times that of toluene, shake well and let it stand, then separate the toluene layer. Then rotary evaporate and concentrate, and dry under vacuum to obtain a colorless viscous liquid, namely benzocyclobutene-grafted butadiene polymer CH-BCB3, whose vinyl molar content is 50.96% and number-average molecular weight is 8000.

[0111] Preparation Example 4

[0112] A benzocyclobutene-grafted butadiene polymer CH-BCB4, and its preparation method is as follows:

[0113] Add 16.9 g of 4-bromobenzocyclobutene, 100 g of polybutadiene Ricon 154, 1.63 g of tris(o-tolyl)phosphine, 0.75 g of palladium acetate, 60 mL of triethylamine and 185 mL of acetonitrile into a flask, and stir at 85 °C for 24 hours under an argon atmosphere. Cool down and rotary evaporate the solvent. Perform flash column chromatography with neutral alumina, rotary evaporate the solvent to obtain a viscous liquid. After dissolving it in toluene, add methanol in an amount 4 times that of toluene, shake well and let it stand, then separate the toluene layer. Then rotary evaporate and concentrate, and dry under vacuum to obtain a colorless viscous liquid, namely benzocyclobutene-grafted butadiene polymer CH-BCB4, with a vinyl molar content of 94.7% and a number-average molecular weight of 5700.

[0114] Preparation Example 5

[0115] A benzocyclobutene-grafted butadiene polymer CH-BCB5, and its preparation method is as follows:

[0116] Add 100 g of 4-bromobenzocyclobutene, 100 g of polybutadiene B3000, 9.65 g of tris(o-tolyl)phosphine, 4.42 g of palladium acetate, 300 mL of triethylamine and 1000 mL of acetonitrile into a flask, and stir at 85 °C for 24 hours under an argon atmosphere. Cool down and rotary evaporate the solvent. Perform flash column chromatography with neutral alumina, rotary evaporate the solvent to obtain a viscous liquid. After dissolving it in toluene, add methanol in an amount 4 times that of toluene, shake well and let it stand, then separate the toluene layer. Then rotary evaporate and concentrate, and dry under vacuum to obtain a colorless viscous liquid, namely benzocyclobutene-grafted butadiene polymer CH-BCB5, with a vinyl molar content of 75.7% and a number-average molecular weight of 4700.

[0117] Comparative Preparation Example 1

[0118] A benzocyclobutene-grafted butadiene polymer CH-BCB-D1, and its preparation method is as follows:

[0119] Add 400 g of 4-bromobenzocyclobutene, 100 g of polybutadiene B3000, 38.59 g of tris(o-tolyl)phosphine, 17.67 g of palladium acetate, 1300 mL of triethylamine and 3000 mL of acetonitrile into a flask, and stir at 85 °C for 24 hours under an argon atmosphere. Cool down and rotary evaporate the solvent. Perform flash column chromatography with neutral alumina, rotary evaporate the solvent to obtain a viscous liquid. After dissolving it in toluene, add methanol in an amount 4 times that of toluene, shake well and let it stand, then separate the toluene layer. Then rotary evaporate and concentrate, and dry under vacuum to obtain a colorless viscous liquid, namely benzocyclobutene-grafted butadiene polymer CH-BCB-D1, with a vinyl molar content of 43.8% and a number-average molecular weight of 9750.

[0120] Comparative Preparation Example 2

[0121] A benzocyclobutene-grafted butadiene polymer CH-BCB-D2, and its preparation method is as follows:

[0122] Add 115 g of 4-bromobenzocyclobutene, 100 g of polybutadiene B3000, 11.09 g of tris(o-methylphenyl)phosphine, 5.08 g of palladium acetate, 400 ml of triethylamine, and 1300 ml of acetonitrile into a flask, and stir at 85 °C for 24 hours under an argon atmosphere. Cool and rotary evaporate the solvent. Quickly pass through a column with neutral alumina, rotary evaporate the solvent to obtain a viscous liquid. After dissolving in toluene, add methanol with a volume 4 times that of toluene, shake well and let stand, and separate the toluene layer. Then rotary evaporate and concentrate, and dry under vacuum to obtain a colorless viscous liquid, which is the benzocyclobutene-grafted butadiene polymer CH-BCB-D2, with a vinyl molar content of 46.11% and a number-average molecular weight of 4941.

[0123] In the following specific embodiments of the present invention, the materials involved are as follows:

[0124] (1) Benzocyclobutene-grafted butadiene polymer

[0125] The benzocyclobutene-grafted butadiene polymers CH-BCB1 to CH-BCB5 provided in Preparation Examples 1-5, and CH-BCB-D1 to CH-BCB-D2 provided in Comparative Preparation Examples 1-2;

[0126] CH-BCB1: The vinyl molar content is 59%, and the number-average molecular weight is 2120;

[0127] CH-BCB2: The vinyl molar content is 63.7%, and the number-average molecular weight is 3900;

[0128] CH-BCB3: The vinyl molar content is 50.96%, and the number-average molecular weight is 8000;

[0129] CH-BCB4: The vinyl molar content is 94.7%, and the number-average molecular weight is 5700;

[0130] CH-BCB5: The vinyl molar content is 75.7%, and the number-average molecular weight is 4700;

[0131] CH-BCB-D1: The vinyl molar content is 43.8%, and the number-average molecular weight is 9750;

[0132] CH-BCB-D2: The vinyl molar content is 46.11%, and the number-average molecular weight is 4941.

[0133] (2) Thermoplastic resin:

[0134] SEBS-MA: KIC19-023: Maleic anhydride-grafted SEBS, Shanghai Kaiteng.

[0135] (3) Filler:

[0136] HM052BYJ: Spherical silica powder, Jiangsu Huimai.

[0137] (4) Photoinitiator

[0138] Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, Macklin reagent;

[0139] IRGACURE 184, BASF, Germany.

[0140] (5) Flame retardant:

[0141] JH-100, Guangzhou Juhang.

[0142] (6) Organic solvent: Toluene.

[0143] Example 1

[0144] A photosensitive resin composition, the specific components and dosages (parts by weight) of the photosensitive resin composition are shown in Table 1.

[0145] A photosensitive film comprising the photosensitive resin composition, the preparation method is as follows:

[0146] (1) Mix each component of the photosensitive resin composition with toluene according to the formula amount to make a photosensitive solution with a solid content of 65%.

[0147] (2) Coat the photosensitive solution on a PET release film to obtain a photosensitive film (thickness: 38 μm), size: 300 mm X 300 mm. Put it into an oven at 110 °C and bake for 3 minutes; after the organic solvent evaporates, use a 365 nm UV LED light source to expose the photosensitive film for 240 s. The resin containing double bonds is crosslinked and cured by exposure and is insoluble in the developer, while the unexposed resin is soluble in the developer; develop with a developer (cyclohexane) for 4 min to elute the uncured resin, and obtain a film surface with a certain roughness. Then chemically deposit copper on this surface, dry the solvent, and then electroplate. The thickness of the electroplated copper is 35 μm. Finally, perform programmed temperature thermal curing on the above copper-plated sample, the curing temperature is 230 °C, the curing time is 60 min, and then cool down to obtain a copper-plated foil film with a high crosslinking density. Make the film into a test PS spline to test the copper plating adhesion PS; etch off the copper plated on the remaining part to make samples for testing Dk / Df and Tg (DMA) to test the above properties.

[0148] (3) Use a 365 nm UV-LED point light source to expose the photosensitive thin film through a mask for 240 s. The exposed area crosslinks and cures and is insoluble in the developer, while the unexposed area is soluble in the developer. Place the exposed thin film in the developer (cyclohexane) for 4 min to develop and obtain a pattern consistent with the mask. Then, thermally cure the developed thin film at a temperature of 230 °C for 120 min, and then cool it down to obtain a lithographically patterned thin film.

[0149] Perform the following performance tests on the photosensitive thin films and lithographically patterned thin films provided in the foregoing examples and comparative examples:

[0150] (1) Resolution of the lithographic pattern: Observe the stereolithographic pattern after development with an optical microscope, and set the minimum size at which the edge of the pattern can be observed smoothly without scum as the pattern resolution L / S (μm);

[0151] (2) Glass transition temperature Tg: Test with a dynamic mechanical analyzer (DMA) Rheometric RSAIII;

[0152] (3) Dielectric constant Dk and dielectric loss tangent Df: Measure using the split post dielectric resonator (SPDR) method with a dielectric analyzer (Dielectric Analyzer) HP Agilent E4991A at a frequency of 10 GHz;

[0153] (4) PS: Test according to the IPC-TM-650 2.4.8C5 standard.

[0154] The test results are shown in Table 1.

[0155] Examples 2-8, Comparative Examples 1-2

[0156] A photosensitive resin composition, a photosensitive thin film, and a lithographically patterned thin film containing the same are different from those in Example 1 in that the formulation of the photosensitive resin composition is different, as specifically shown in Table 1 and Table 2; among them, the dosage unit of each component is "parts", and "--" represents that the component is not added; the preparation methods and performance test methods of the photosensitive thin film and the lithographically patterned thin film are the same as those in Example 1.

[0157] Table 1

[0158]

[0159]

[0160] Table 2

[0161]

[0162]

[0163] Combined with the foregoing performance test data, it can be seen that the photosensitive resin composition provided by the present invention is used for photosensitive films and for preparing copper clad laminates and lithographically patterned films, enabling the copper clad laminate to have a Dk of 2.38 - 2.6, a Df of 0.00055 - 0.001 at 10 GHz, a glass transition temperature Tg of 213 - 265 °C, a peel strength of 0.37 - 0.51 N / mm, and the resolution of the lithographically patterned film is 9 - 27 μm, and it has excellent dielectric properties, mechanical properties and heat resistance at the same time.

[0164] For the photosensitive resin composition provided in Comparative Example 1, the vinyl molar content in the benzocyclobutene-grafted butadiene polymer is lower than 50%, being 43.8%. Due to the low content of C=C double bonds, the degree of photocuring is low, and the developing effect of the developer cyclohexane is strong. During the developing process, a lot of the photocured part has been washed away, and the next operation cannot be carried out. For the photosensitive resin composition provided in Comparative Example 2, the content of C=C double bonds is 46.11%. The photocuring step is not sufficient to cure the adhesive film sufficiently, resulting in the elution of the cured part during the developing process, leading to a decrease in subsequent PS and a deterioration in resolution.

[0165] The applicant declares that the present invention uses the above embodiments to illustrate the photosensitive resin composition, photosensitive film and their applications of the present invention, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the products of the present invention, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A photosensitive resin composition, characterized in that, The photosensitive resin composition comprises the following components: benzocyclobutene grafted butadiene polymer, photoinitiator and organic solvent; In the benzocyclobutene grafted butadiene polymer, based on the total molar amount of -CH=CH2 groups and benzocyclobutene groups being 100%, the molar content of -CH=CH2 groups is greater than 50%.

2. The photosensitive resin composition according to claim 1, wherein In the benzocyclobutene grafted butadiene polymer, based on the total molar amount of -CH=CH2 groups and benzocyclobutene groups being 100%, the molar content of -CH=CH2 groups is 60 - 95%, more preferably 70 - 90%.

3. The photosensitive resin composition according to claim 1 or 2, wherein The benzocyclobutene grafted butadiene polymer comprises at least one structural unit A and at least one structural unit B; The structural unit A has the structure shown in Formula I: R1 is vinylene and / or ethylene; The structural unit B has the structure shown in Formula II: R2 is vinyl, ethyl and / or phenyl.

4. The photosensitive resin composition according to any one of claims 1-3, characterized in that The benzocyclobutene grafted butadiene polymer comprises structural unit A1, and the structural unit A1 has the structure shown in Formula IA: Preferably, the benzocyclobutene grafted butadiene polymer comprises structural unit B1, and the structural unit B1 has the structure shown in Formula IIA: Preferably, the benzocyclobutene grafted butadiene polymer further comprises structural unit C, and the structural unit C has the structure shown in Formula IIIA and / or Formula IIIB: Preferably, the molar percentage content of structural unit C in the benzocyclobutene grafted butadiene polymer is ≤40%, more preferably ≤30%, still more preferably ≤20%.

5. The photosensitive resin composition according to any one of claims 1-4, characterized in that, The photoinitiator includes any one or a combination of at least two of 1-hydroxy-cyclohexyl-phenyl ketone, 2,6-bis(4-azidobenzylidene)cyclohexanone, 3,3'-carbonylbis(7-diethylaminocoumarin), benzophenone or diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide; Preferably, based on the mass of the organic components in the photosensitive resin composition being 100 parts, the dosage of the photoinitiator is 1 - 10 parts; Preferably, the organic solvent includes any one or a combination of at least two of toluene, xylene, chloroform, dichloromethane, n-hexane, ethyl acetate, butyl acetate, petroleum ether, cyclohexanone or cyclohexane; Preferably, the dosage of the organic solvent is such that the solid content of the glue solution in the photosensitive resin composition is 60 - 70%.

6. The photosensitive resin composition according to any one of claims 1-5, characterized in that, The photosensitive resin composition further includes a thermoplastic resin; Preferably, based on the total weight of the photosensitive resin composition being 100%, the mass percentage content of the thermoplastic resin is ≤80%; Preferably, the thermoplastic resin includes a hydrogenated styrene-butadiene block copolymer and / or a thermoplastic polyphenylene ether.

7. The photosensitive resin composition according to any one of claims 1-6, characterized in that The photosensitive resin composition further includes a filler; Preferably, based on the mass of the organic components in the photosensitive resin composition being 100 parts, the mass of the filler is 5 - 40 parts; Preferably, the filler is an inorganic filler and / or an organic filler, more preferably an inorganic filler; Preferably, the inorganic filler includes any one or a combination of at least two of silica, aluminum hydroxide, alumina, talcum powder, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate, mica; Preferably, the organic filler includes any one or a combination of at least two of polyphenylene ether filler, polytetrafluoroethylene filler, polyetheretherketone filler, polyphenylene sulfide filler, polyethersulfone filler; Preferably, the median particle size of the filler is 30 - 500 nm; Preferably, the filler includes a surface-treated filler; Preferably, the surface treatment agent for the surface treatment includes any one or a combination of at least two of silane coupling agents, organosilicon oligomers, titanate coupling agents; Preferably, based on 100 parts by mass of the filler to be treated, the mass of the surface treatment agent is 0.1 - 5 parts; Preferably, the photosensitive resin composition further includes a flame retardant; Preferably, based on 100 parts by mass of the resin in the photosensitive resin composition, the mass of the flame retardant is 1 - 50 parts; Preferably, the flame retardant includes a halogen-containing flame retardant and a halogen-free flame retardant; Preferably, the halogen-containing flame retardant includes any one or a combination of at least two of decabromodiphenylethane, brominated polystyrene, polybrominated polystyrene, brominated polyphenylene ether, ethylene bis-tetrabromophthalimide; Preferably, the halogen-free flame retardant includes any one or a combination of at least two of phosphazene flame retardants, DOPO flame retardants, phosphonate flame retardants, organic hypophosphite flame retardants.

8. A photosensitive film, characterized in that, The material of the photosensitive film includes the photosensitive resin composition according to any one of claims 1 - 7; Preferably, the photosensitive film is prepared by coating the photosensitive resin composition on a release material and drying; Preferably, the thickness of the photosensitive film is 5 - 50 μm.

9. A multilayer printed circuit board, characterized in that, The multilayer printed circuit board contains an interlayer insulating layer, and the interlayer insulating layer is formed using the photosensitive film according to claim 8.

10. A method for preparing a multi-layer printed circuit board, characterized in that, The preparation method has the following steps (1) to (3): Step (1): The step of laminating the photosensitive film according to claim 8 on one side or both sides of a circuit board; Step (2): The step of exposing and developing the photosensitive film in step (1) to form an interlayer insulating layer having through holes; Step (3): The step of forming a circuit pattern on the interlayer insulating layer; Preferably, between step (2) and step (3), there is also step (2 - 1): The step of heat-treating the interlayer insulating layer; Preferably, between step (2) and step (3), there is also step (2 - 2): The step of roughening the through holes and the interlayer insulating layer.

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