Photosensitive resin composition, photosensitive element, printed wiring board, and semiconductor package

Abstract

The invention provides a photosensitive resin composition, a photosensitive element, a printed circuit board and a semiconductor package, and particularly relates to the technical field of printed circuit boards. The photosensitive resin composition includes (A) an acid-modified unsaturated epoxy resin, (B) a thermosetting resin, (C) a photoinitiator, (D) a photopolymerizable compound, (E) an inorganic filler, and (G) an organic peroxide. The acid-soluble particles are introduced into the resin composition, so that the interface bonding characteristic and the surface flatness of the interlayer insulating layer are remarkably optimized. After exposure and development, surface acid soluble particles are selectively dissolved through step-by-step coarsening, so that on the basis of effectively reducing the surface roughness (Ra < = 0.15 [mu] m) of the insulating layer and reducing the transmission loss of high-frequency signals, the excellent bonding strength between the insulating layer and a subsequent copper plating layer is still kept, and the reliability problems such as layering or circuit stripping are avoided; the method is suitable for the manufacturing requirements of high-density interconnection (HDI) plates and semiconductor packaging substrates.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board technology, and in particular to a photosensitive resin composition, a photosensitive element, a printed circuit board, and a semiconductor package. Background Technology

[0002] As electronic devices evolve towards miniaturization and higher performance, printed circuit boards (PCBs), especially semiconductor packaging substrates (PKG substrates), are moving towards high-density wiring, miniaturization, and multilayering. Traditional build-up (BU) processes typically employ thermosetting interlayer insulating films (such as BUF) and form vias through laser-driven per-via processing. However, this method suffers from low efficiency and high cost when dealing with the demand for a large number of tiny vias, making it difficult to meet the mass production requirements of advanced packaging.

[0003] To improve the efficiency of via fabrication, photosensitive resin materials combined with photolithography have become a research hotspot. These materials can rapidly form high-density micropores through a single exposure and development process, significantly improving production efficiency. Existing technologies aim to improve resolution and metal adhesion. However, these materials still have shortcomings in achieving uniform curing and synergistic reactions among multiple resins. Especially when using various thermosetting resins such as epoxy, allyl, or bismaleimide, uneven curing can lead to uneven cross-linking networks, affecting reliability.

[0004] Furthermore, with the development of high-frequency applications, the requirements for low dielectric loss (low tanδ) of insulating materials are becoming increasingly stringent. Existing photosensitive systems often suffer from poor dielectric properties due to incomplete curing or poor component compatibility, or exhibit cracking and peeling during temperature cycling (TCT) and damp heat aging tests. Therefore, there is an urgent need for a photosensitive resin composition that can achieve photo-thermal synergistic curing while maintaining both low dielectric properties and high adhesion reliability to meet the demands of advanced encapsulation for high-performance interlayer insulating materials.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a photosensitive resin composition, a photosensitive element, a printed circuit board, and a semiconductor package, aiming to solve at least one of the above-mentioned technical problems in the prior art.

[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A first aspect of the present invention provides a photosensitive resin composition comprising: (A) an acid-modified unsaturated epoxy resin, (B) a thermosetting resin, (C) a photoinitiator, (D) a photopolymerizable compound, (E) an inorganic filler, and (G) an organic peroxide.

[0008] Furthermore, the (G) organic peroxide has a half-life temperature of 140~200°C within 1 minute.

[0009] Further, the photosensitive resin composition comprises, by weight, 100 parts (A) (based on resin solids), 40-60 parts (B), 0.2-2.0 parts (C), 30-50 parts (D), 100-400 parts (E), and 1-5 parts (G).

[0010] Further, the (A) acid-modified unsaturated epoxy resin includes at least one of acid-modified unsaturated epoxy resin having a bisphenol A backbone, acid-modified unsaturated epoxy resin having a bisphenol F backbone, and acid-modified unsaturated epoxy resin having an alicyclic backbone.

[0011] Preferably, the structural formula of the alicyclic skeleton is as follows: .

[0012] Among them, R A1 It is a C1~C12 alkyl group, R A1 Replace at any position in the alicyclic framework; m 1 Integers from 0 to 6; * indicates a connection point with other structures.

[0013] Further, the (B) thermosetting resin includes at least one of epoxy resin, allyl resin, and unsaturated imide resin.

[0014] Furthermore, the photoinitiator (C) includes acylphosphine oxide-based photoinitiators and / or oxime ester-based photoinitiators.

[0015] Preferably, the (D) photopolymerizable compound is a photopolymerizable compound that has two or more unsaturated groups and is liquid at 25°C or a photopolymerizable compound that is solid at 25°C.

[0016] Preferably, the (E) inorganic filler comprises spherical silica with an average particle size of 0.6 μm.

[0017] Preferably, the photosensitive resin composition further includes 0.1 to 1.5 parts of pigment.

[0018] A second aspect of the present invention provides a photosensitive element, including a support and a photosensitive resin layer disposed on the surface of the support; The photosensitive resin layer is formed from the photosensitive resin composition.

[0019] A third aspect of the present invention provides a printed circuit board, comprising an insulating layer formed by exposure, development and curing of the aforementioned photosensitive element.

[0020] A fourth aspect of the present invention provides a semiconductor package including a semiconductor element and the printed circuit board.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects: This invention introduces organic peroxides into the resin composition to initiate a free radical reaction, promoting the simultaneous and mutual cross-linking of resins (A) and (B) to form a uniform and dense three-dimensional network structure. This significantly improves the curing uniformity and bonding strength of the interlayer insulating layer. The resulting material not only possesses low dielectric tangent, excellent resistance to damp heat and temperature cycling reliability (TCT), but also effectively suppresses cracking and peeling, while maintaining good developability and high-resolution via forming capability. Ultimately, this enables the stable manufacturing of high-density, high-performance printed circuit boards and semiconductor packages. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of the invention, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0024] A first aspect of the present invention provides a photosensitive resin composition comprising: (A) an acid-modified unsaturated epoxy resin, (B) a thermosetting resin, (C) a photoinitiator, (D) a photopolymerizable compound, (E) an inorganic filler, and (G) an organic peroxide.

[0025] Furthermore, the (G) organic peroxide has a half-life temperature of 140~200℃ within 1 minute. Within this temperature range, the organic peroxide remains stable during room temperature storage and pre-drying of the resin composition, and is not prone to premature decomposition, thus ensuring the long-term usability and good developability of the resin composition. In the subsequent high-temperature curing stage (≥150℃), it can rapidly decompose to generate free radicals, effectively initiating a synergistic free radical crosslinking reaction between the acid-modified unsaturated epoxy resin, thermosetting resin, and photopolymerizable compound, forming a uniform and dense three-dimensional network structure. This not only improves the crosslinking density and bonding strength of the interlayer insulation layer but also significantly improves the material's heat resistance, dielectric properties (Df ≤ 0.002), damp heat reliability (B-HAST), and thermal shock resistance (TCT), achieving an excellent balance between processing stability and final high performance, making it particularly suitable for the manufacturing needs of high-density interconnect boards and semiconductor packaging substrates.

[0026] In some embodiments of the present invention, the photosensitive resin composition further includes (F) acid-soluble particles.

[0027] Furthermore, the acid-soluble particles dissolve in a 50 mL / L sulfuric acid aqueous solution at 70 °C for ≤20 min.

[0028] Preferably, (F) is hydrotalcite.

[0029] Preferably, the average particle size of the hydrotalcite is 30-90 nm, enabling uniform and precise microstructure control on the surface of the interlayer insulating layer. Acid-soluble particles within this particle size range exhibit good dispersibility in the resin composition, are less prone to sedimentation or agglomeration, and contribute to the stability of the coating process. During subsequent stepwise roughening, after selective dissolution with an acidic solution, uniformly sized and densely distributed micro-pits can be formed on the insulating layer surface, effectively reducing surface roughness (Ra can be as low as below 0.15 μm), reducing conductor loss in high-frequency signal transmission, and providing sufficient anchoring effect for subsequent copper plating. This maintains excellent adhesive strength (peel strength ≥ 4 N / cm) while avoiding the risk of interfacial delamination. Furthermore, the nanoscale particle size provides better compatibility with the resin matrix, helping to maintain the overall dielectric properties of the material (Df ≤ 0.002), making it particularly suitable for the stringent requirements of low loss and high reliability in high-density interconnect (HDI) boards and semiconductor packaging substrates.

[0030] Further, the photosensitive resin composition comprises, by weight, 100 parts (A) (based on resin solids), 40-60 parts (B), 0.2-2.0 parts (C), 30-50 parts (D), 100-400 parts (E), and 1-5 parts (G).

[0031] It should be noted that in the formulation of the photosensitive resin composition, the amount of component (A) acid-modified unsaturated epoxy resin is set at 100 parts based on its solvent-free solid portion, serving as a reference standard for the overall formulation ratio. This means that the addition amounts of other components (such as photoinitiators, thermosetting resins, inorganic fillers, etc.) are calculated and proportioned based on the effective solid content of the resin, rather than the total weight including solvents.

[0032] Typical, but not limiting, the photosensitive resin composition comprises, by weight, (A) 100 parts (based on resin solids); (B) for example, 40, 41, 42, 43, 44, 45, 50, or 60 parts, or any value within the range of 40 to 60 parts; (C) for example, 0.2, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, or 2.0 parts, or any value within the range of 0.2 to 2.0 parts; (D) for example, 30 parts, 3 (A) 5, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, or 50 portions, or any value within the range of 30 to 50 portions; (E) For example, 100, 150, 200, 220, 240, 260, 280, 300, 350, or 400 portions, or any value within the range of 100 to 400 portions; (G) For example, 0.1, 0.5, 1, 2, 3, 4, or 5 portions, or any value within the range of 0.1 to 5 portions.

[0033] Further, the (A) acid-modified unsaturated epoxy resin includes at least one of acid-modified unsaturated epoxy resin having a bisphenol A backbone, acid-modified unsaturated epoxy resin having a bisphenol F backbone, and acid-modified unsaturated epoxy resin having an alicyclic backbone.

[0034] Preferably, the structural formula of the alicyclic skeleton is as follows: .

[0035] Among them, R A1 It is a C1~C12 alkyl group, R A1 Replace at any position in the alicyclic framework; m 1 Integers from 0 to 6; * indicates a connection point with other structures.

[0036] R A1 It is a C1-C12 alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, etc. R A1 Alkyl groups with 1 to 6 carbon atoms are preferred, alkyl groups with 1 to 3 carbon atoms are more preferred, and methyl groups are even more preferred.

[0037] m 1 It is an integer from 0 to 6, preferably an integer from 0 to 2, and more preferably 0.

[0038] m 1 When the integer is between 2 and 6, multiple R A1 They can be the same or different. Furthermore, multiple Rs... A1 It can substitute on the same carbon atom or on different carbon atoms, within the possible range.

[0039] *This is a bonding site with other structures, which can be bonded by any carbon atom on the alicyclic framework.

[0040] The thermosetting resin (B) refers to a class of polymeric prepolymers that can undergo further curing reactions under heating conditions to form a highly cross-linked three-dimensional network structure. Its main function is to achieve deep thermal cross-linking through subsequent high-temperature curing treatment after the photosensitive resin composition has undergone exposure, development, and initial photocuring. This significantly improves the glass transition temperature (Tg), mechanical strength, heat resistance, dimensional stability, and chemical resistance of the interlayer insulating layer, meeting the reliability requirements of high-density interconnect (HDI) boards and semiconductor packaging substrates under harsh process environments such as multilayer stacking, electroplating, and reflow soldering.

[0041] Further, the (B) thermosetting resin includes at least one of epoxy resin, allyl resin, and unsaturated imide resin.

[0042] In this invention, the thermosetting resin includes at least one of epoxy resin, allyl resin, and unsaturated imide resin. During subsequent heating and curing, it participates in a crosslinking reaction to form a highly crosslinked three-dimensional network structure, thereby significantly improving the heat resistance, mechanical strength, dimensional stability, and chemical resistance of the interlayer insulation layer. Epoxy resin has abundant epoxy groups and can further react with acid-modified epoxy resin or other components containing active hydrogen at high temperatures, enhancing the overall crosslinking density and adhesion. Although allyl resin has relatively low reactivity, it exhibits excellent heat resistance and low dielectric properties after curing, which is beneficial for high-frequency signal transmission. Unsaturated imide resin combines high heat resistance (derived from the imide ring structure) and polymerizable double bonds, enabling it to participate in photo- or thermo-curing reactions under free radical initiation conditions, achieving synergistic crosslinking with other components, making it particularly suitable for semiconductor packaging substrates requiring high reliability. The three resins can be used individually or in combination according to performance requirements to balance the material's processability, dielectric properties, and final thermomechanical properties. Furthermore, the photoinitiator (C) includes acylphosphine oxide-based photoinitiators and / or oxime ester-based photoinitiators.

[0043] The combined use of acylphosphine oxide-based photoinitiators and oxime ester-based photoinitiators can broaden the photoinitiation response range, achieve uniform curing from the surface to the interior, effectively overcome the shadowing effect in thick film layers or the light attenuation problem caused by scattering of inorganic fillers, ensure that the photocrosslinking region fully carries out the crosslinking reaction, thereby improving the integrity and mechanical stability of the pattern after development, and meeting the requirements of high-density interconnect structures for fine circuit forming and high-reliability insulation layers.

[0044] Preferably, the (D) photopolymerizable compound is a photopolymerizable compound that has two or more unsaturated groups and is liquid at 25°C or a photopolymerizable compound that is solid at 25°C.

[0045] Component (D) consists of two types of multifunctional photopolymerizable monomers or oligomers: one type is a liquid at room temperature (25°C) containing two or more polymerizable unsaturated bonds (such as acryloyl or methacryloyl groups) per molecule, and the other type is a solid at 25°C but still contains two or more unsaturated bonds. This liquid-solid combination is designed to balance processability and final material properties.

[0046] By combining liquid and solid multifunctional monomers, the operational stability of the resin composition during storage and coating is ensured, and an interlayer insulating layer with high crosslinking density, low dielectric loss and excellent thermomechanical properties is constructed after exposure and curing, which meets the requirements of high-frequency and high-speed applications for comprehensive material performance.

[0047] Preferably, the (E) inorganic filler comprises spherical silica with an average particle size of 0.6 μm.

[0048] Preferably, the photosensitive resin composition further includes 0.1 to 1.5 parts of pigment.

[0049] In some embodiments of the present invention, the insulating layer may be incorporating pigments to improve appearance (e.g., to conceal conductor patterns). Typical but not limited pigments include phthalocyanine blue, phthalocyanine green, azo green, diazo yellow, ultramarine, titanium dioxide, carbon black, naphthalene black, and other pigments.

[0050] Typically, but not limitingly, the amount of pigment used can be, for example, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.7 parts, 0.9 parts, 1.1 parts, 1.3 parts, or 1.5 parts, or any value in the range of 0.1 to 1.5 parts.

[0051] A second aspect of the present invention provides a photosensitive element, including a support and a photosensitive resin layer disposed on the surface of the support; The photosensitive resin layer is formed from the photosensitive resin composition.

[0052] A third aspect of the present invention provides a printed circuit board, comprising an insulating layer formed by exposure, development and curing of the aforementioned photosensitive element.

[0053] A fourth aspect of the present invention provides a semiconductor package including a semiconductor element and the printed circuit board.

[0054] The present invention is further illustrated below with specific embodiments and comparative examples. However, it should be understood that these embodiments are merely for illustrative purposes and should not be construed as limiting the invention in any way. Unless otherwise specified, the raw materials used in the embodiments and comparative examples of the present invention were carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0055] Synthesis example 1 250 parts by weight of dicyclopentadiene (DCPD) type epoxy resin (manufactured by DIC Corporation, trade name "HP-7200"), 70 parts by weight of acrylic acid, 0.5 parts by weight of methyl hydroquinone, and 120 parts by weight of propylene glycol monomethyl ether acetate (PGMEA) were stirred and mixed at 90°C to obtain a resin solution. The resin solution was cooled to 60°C, and 2 parts by weight of triphenylphosphine (TPP) were added. The mixture was reacted at 100°C with stirring until the acid value of the resin solution dropped below 1 mgKOH / g. 98 parts by weight of tetrahydrophthalic anhydride (THPA) and 850 parts by weight of PGMEA were added to the reacted resin solution. The mixture was reacted at 80°C and then cooled to room temperature to obtain an acid-modified epoxy acrylate resin (A-1) solution (65% by weight solids).

[0056] Synthesis example 2 350 parts by weight of modified phenolic multifunctional epoxy resin (manufactured by DIC Corporation, triphenylmethane type epoxy resin, trade name "HP-7241"), 70 parts by weight of acrylic acid, 0.5 parts by weight of methylhydroquinone, and 120 parts by weight of PGMEA were stirred and mixed at 90°C to obtain a resin solution. The resin solution was cooled to 60°C, and 2 parts by weight of TPP were added. The mixture was reacted at 100°C with stirring until the acid value of the resin solution dropped below 1 mgKOH / g. 98 parts by weight of THPA and 850 parts by weight of PGMEA were added to the reacted resin solution, and the mixture was reacted at 80°C and then cooled to room temperature to obtain an acid-modified epoxy acrylate resin (A-2) solution (73% by weight solids). Non-volatile matter calculation: Weigh 0.75g ± 0.25g of the resin solution obtained from the synthesis example into a metal container using a precision balance. After drying in a hot air circulating box-type drying oven at 150℃ for 30 minutes, calculate the non-volatile matter (NV) according to the following formula: NV(wt%)=[(W3-W1) / W2]×100; W1: Mass of empty metal container (g), W2: Mass of resin solution before drying (g), W3: Total mass of metal container and resin after drying (g).

[0057] The following materials were used in components (B) to (H) and the coloring pigments in the examples and comparative examples: B-1: Biphenyl type epoxy resin (Nippon Kayaku Corporation, trade name "NC-3000H"); B-2: Biphenyl type epoxy resin (manufactured by Mitsubishi Chemical, trade name "YX-4000"); B-3: Bismaleimide resin (manufactured by Designer Molecules, trade name "BMI-3000"); B-4: Bismaleimide resin (manufactured by Jinan Shengquan Group, trade name "PFB401"); B-5: Triallyl isocyanurate (manufactured by Hefei Anbang Chemical Co., Ltd., trade name "TAIC"); B-6: Diallyl phthalate resin (manufactured by Osaka Soda, trade name "DAP K"); C-1: Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins BV, trade name "Omnirad 819"); C-2: 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]acetophenone-1-(O-acetyloxime) (manufactured by BASF, trade name "Irgacure OXE-02"); D-1: Dipentaerythritol polyacrylate (manufactured by Shin-Nakamura Chemical Industry, trade name "A-DPH"); D-2: Tris(2-Acryloyloxyethyl)isocyanurate (manufactured by Shin-Nakamura Chemical Industry, trade name "A-9300"); D-3: Trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Industry, trade name "A-TMPT"); E-1: Spherical silica (manufactured by Admatechs, trade name "SC2500-SMJ"); E-2: Silica sol (manufactured by Nissan Chemical, trade name "PMA-ST"); F-1: Nano-hydrotalcite (manufactured by Toda Industries, trade name "Small Particles", average particle size 60nm); G-1: 1,1-Di(tert-hexylperoxy)cyclohexane (1-minute half-life temperature: 149.2℃); G-2: Dicumyl peroxide (1-minute half-life temperature: 175.2℃); G-3: Bis(2-tert-butylperoxyisopropyl)benzene (1-minute half-life temperature: 175.4℃); G-4: Di-tert-butyl peroxide (1-minute half-life temperature: 185.9℃); G-5: 1,1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate (1-minute half-life temperature: 124.3℃). H-1: 4-Methyl-2-phenyl-1H-imidazole (manufactured by Evonik, trade name "Curezol 2P4MZ"); Coloring pigment: Phthalocyanine Blue 15:3 (manufactured by ZE YACHEM, trade name "Corimax Blue 7090P").

[0058] Example Table 1

[0059] Comparative Example Table 2

[0060] Preparation methods for the examples and comparative examples: Following the proportions shown in Table 1 or Table 2 (where values ​​are in parts by mass, and solution composition is converted to solid content), the components were mixed and then kneaded using a three-roll mill. Subsequently, to adjust the non-volatile component concentration to 65 wt%, an appropriate amount of methyl ethyl ketone was added for dilution, thus obtaining the photosensitive resin composition.

[0061] Test case Photosensitive resin films were prepared using the photosensitive resin compositions of the examples and comparative examples: a 38 μm thick polyethylene terephthalate film (manufactured by Yihua Toray Polyester Film Co., Ltd., trade name "38UY34") was used as the carrier base film. On this carrier base film, the coating thickness was controlled to achieve a film thickness of 60 μm after drying. The prepared photosensitive resin composition was then coated onto the surface of the base film and dried in a hot air circulating box drying oven at 90°C for 30 minutes to form a photosensitive resin film (photosensitive layer). Subsequently, a polyethylene film (manufactured by Oji F-Tex Co., Ltd., trade name "ALPHAN MA-411") was laminated onto the surface of the photosensitive resin film (photosensitive layer) opposite to the carrier base film as a protective film, thus obtaining a photosensitive resin film composite encapsulated by the carrier base film and the protective film.

[0062] The obtained photosensitive resin film was subjected to the following tests: 1. Thick film developability: After peeling off the protective film of a 60μm thick photosensitive resin film, a laminating vacuum laminator (manufactured by Chih Sheng Industrial Co., Ltd., trade name "VL-M24") is used to laminate it onto a 1.0mm thick copper-clad laminate under the following conditions: lamination pressure 0.4MPa, lamination hot plate temperature 60℃, vacuum time 30 seconds, lamination time 30 seconds, and air pressure below 4kPa, to obtain a laminate.

[0063] The resulting laminate was treated as follows: it was developed with a 1% Na2CO3 aqueous solution at 30°C under a jet pressure of 0.2MPa for 120 seconds, and then rinsed with pure water under a jet pressure of 0.2MPa for 90 seconds. The residue was then checked: no residue: no resin residue was visible on the surface of the copper foil; residue: resin residue was visible on the surface of the copper foil.

[0064] 2. Storage stability: After peeling off the protective film from the 60μm thick photosensitive resin film, it is laminated with a 1.0mm thick copper-clad laminate using a laminating vacuum laminator (manufactured by Chih Sheng Industrial Co., Ltd., model "VL-M24") under the following parameters: lamination pressure 0.4MPa, lamination hot plate temperature 60℃, vacuuming time 30 seconds, lamination time 30 seconds, ambient air pressure ≤4kPa, to obtain the laminate.

[0065] After storing the obtained laminate at 23°C under light-protected conditions for 36 hours, it was developed with a 1% Na2CO3 aqueous solution at 30°C at a spray pressure of 0.2MPa for 90 seconds, and then rinsed with pure water at a spray pressure of 0.2MPa for 90 seconds. Finally, the residue was checked: no residue: no resin residue was visible on the surface of the copper foil; residue present: resin residue was visible on the surface of the copper foil.

[0066] 3. Surface roughness: Samples were prepared according to the method for preparing the laminate for evaluation. After roughening treatment and subsequent acid treatment, the surface roughness (Ra) of the substrate was measured according to the following method: Measurement equipment: White light interference microscope (Bruker Contour X-200) Measurement conditions: VSI mode, 50x objective lens, measurement range 170×140μm, and the arithmetic mean of 5 measurement points was taken as the final result.

[0067] Judgment criteria: Good: Surface roughness (Ra) after roughening ≤ 0.1μm; Poor: Surface roughness (Ra) after roughening > 0.1μm.

[0068] 4. Peel strength: After peeling off the protective film from the photosensitive resin film with the carrier film and protective film, the film is laminated onto a 1.0 mm thick copper-clad laminate using a laminating vacuum laminator (manufactured by Chih Sheng Industrial Co., Ltd., model "VL-M24") under the conditions of 0.4 MPa lamination pressure, 60℃ lamination hot plate temperature, 30 seconds vacuum time, 30 seconds lamination time and ≤4 kPa air pressure to obtain the laminate.

[0069] The resulting laminate was first exposed to a polyethylene terephthalate (PET) film using a UV LED light source irradiation device (manufactured by Yuntong Technology Co., Ltd., model "UV LED Curing Box (365, 385, 395, 405 nm four-wave hybrid type)") at a dose of 500 mJ / cm². The PET carrier film was then peeled off, followed by development in a 1% Na₂CO₃ aqueous solution at 30°C (0.2 MPa jet pressure, 90 seconds) and washing with pure water (0.2 MPa jet pressure, 90 seconds). After removing the moisture, the laminate was heated at 180°C for 1 hour to form a cured film on the copper-clad laminate, thus obtaining the "evaluation laminate".

[0070] 5. Roughening treatment process: First, 2 L of Swelling Dip Securigant MV (manufactured by Atotech Japan Co., Ltd., sodium hydroxide concentration 3 g / L) containing sodium hydroxide is used to immerse the evaluation laminate at 70°C for 5 minutes, followed by immersion in water at 25°C for 1 minute and rinsing with running water for 3 minutes.

[0071] Next, using 2 L of Dosing Securigant PMV (manufactured by Atotech Japan Co., Ltd., sodium hydroxide concentration 40 g / L) containing sodium hydroxide, the evaluation laminate was immersed in the solution at 60°C for 5 minutes, followed by rinsing with pure water at 70°C for 1 minute.

[0072] Then, 2000 mL of Reduction Solution Securigant MV (manufactured by Atotech Japan Co., Ltd.) with added sulfuric acid to a concentration of 48 mL / L was heated to 50°C. The evaluation laminate was then immersed for 5 minutes, followed by 1 minute of immersion and 3 minutes of rinsing with running water at 25°C.

[0073] 6. Copper circuit layer formation process: Degrease and clean the copper circuit layer by treating it with 60°C alkaline cleaner Cleaner Securigant 902 (manufactured by Atotech Japan Co., Ltd.) for 5 minutes, then treat it with 23°C pre-dip solution Predip Neogant B (manufactured by Atotech Japan Co., Ltd.) for 1 minute, then treat it with 35°C activator Neogant 834 (manufactured by Atotech Japan Co., Ltd.) for 5 minutes, and finally treat it with 30°C reducer Neogant WA (manufactured by Atotech Japan Co., Ltd.) for 5 minutes.

[0074] The treated evaluation laminate was immersed in a chemical copper plating solution (containing Basic Printgant MV-TP1, Copper Printgant MV-TP1, Moderator Printgant MV-TP1, Stabilizer Printgant MV-TP1, Reducer Cu (all manufactured by Atotech Japan Co., Ltd.) and sodium hydroxide) to perform chemical copper plating to a thickness of approximately 0.5 μm. After chemical plating, it was annealed at 120°C for 30 minutes to remove residual hydrogen, followed by copper sulfate electroplating, and then annealed at 180°C for 60 minutes to form a 25 μm thick conductor layer.

[0075] After the final laminated board has been left to stand for 12 hours, peel off one end of the copper foil (10 mm wide). Fix the laminated board, clamp the peeled end with a jig, and peel the copper foil vertically at a rate of 50 mm / min. Repeat the peel strength measurement 8 times and take the average value. The peel strength evaluation is performed in accordance with Section 5.8 (Copper Foil Peel Strength) of GB / T 4722-2017 standard, and is judged according to the following standards: Good: peel strength ≥ 4 N / cm; Poor: peel strength < 4 N / cm.

[0076] 7. Prepare a comb-shaped electrode substrate with a linewidth / spacing of 30μm / 30μm on the copper surface of a printed circuit board (manufactured by Nan Ya New Materials Co., Ltd., trade name "NY8888") with a copper foil of 18μm thickness and a bismaleimide triazine substrate, by etching. After peeling off the protective film of the "photosensitive resin film with carrier film and protective film", use a lamination vacuum laminator (manufactured by Chih Sheng Industrial Co., Ltd., trade name "VL-M24") to laminate it onto the above substrate under the conditions of lamination pressure of 0.4 MPa, lamination hot plate temperature of 60℃, vacuum time of 30 seconds, lamination time of 30 seconds, and air pressure ≤4 kPa to obtain a laminate.

[0077] The resulting laminate was exposed to a UV LED light source (manufactured by Yuntong Technology Co., Ltd., trade name "UV LED Curing Box (365, 385, 395, 405 nm four-wave hybrid type)") at a dose of 500 mJ / cm² through a polyethylene terephthalate film. The substrate PET film was then peeled off, followed by development in a 1% Na₂CO₃ aqueous solution at 30°C (0.2 MPa jet pressure, 90 seconds) and washing with pure water (0.2 MPa jet pressure, 90 seconds). After removing the moisture, the substrate was heated at 180°C for 1 hour to form a photosensitive element cured film, thus obtaining the evaluation substrate.

[0078] The substrate was subjected to a DC 5V voltage for 200 hours at 135°C and 85% relative humidity. The resistance was then measured and evaluated according to the following criteria: Good: Resistance ≥ 1.0 × 10⁻⁶. 6 Ω; Faulty: Resistance value <1.0×10 6 Ω or a short circuit occurred 200 hours ago.

[0079] 8. Dielectric loss tangent measurement: After peeling off the protective film from the photosensitive resin film with carrier film and protective film prepared by the above method, a vacuum laminator (manufactured by Chih Sheng Industrial Co., Ltd., model VL-M24) is used to fully coat the Teflon (registered trademark) film surface under the conditions of 0.4MPa lamination pressure, 60℃ lamination hot plate temperature, 30 seconds vacuum time, 30 seconds lamination time and air pressure below 4 kPa, forming a 60μm thick dry film layer.

[0080] On this film, through the polyethylene terephthalate film, a UVLED light source (manufactured by Yuntong Technology Co., Ltd., model UVLED curing box (365 / 385 / 395 / 405 nm four-wave hybrid type)) is used with an ultraviolet light irradiation device at 500 mJ / cm². 2 The sample was exposed to a specific concentration, then the carrier PET film was peeled off. It was then developed in a 1% Na₂CO₃ aqueous solution at 30°C (0.2 MPa spray pressure, 90 seconds) and rinsed with pure water (0.2 MPa spray pressure, 90 seconds). After removing the moisture, it was heated at 180°C for 1 hour to form a cured photosensitive resin composition on the Teflon (registered trademark) film. This cured material was then peeled off from the Teflon film to obtain the test piece.

[0081] The following processes are then performed in sequence: First, the test piece was immersed in a swelling solution (2L of "Swelling Dip Securigant MV" [manufactured by Atotech Japan Co., Ltd.] containing sodium hydroxide, with a sodium hydroxide concentration of 3 g / L) at 70°C for 5 minutes, followed by immersion in water at 25°C for 1 minute and rinsing with running water for 3 minutes. Next, the sample was immersed in a roughening solution (2L of "Dosing Securigant PMV" [manufactured by Atotech Japan Co., Ltd.] containing sodium hydroxide, with a sodium hydroxide concentration of 40 g / L) at 60°C for 5 minutes, followed by rinsing with pure water at 70°C for 1 minute. Then, the test strip was immersed in the reducing solution ("Reduction Solution SecurigantMV" [manufactured by Atotech Japan Co., Ltd.] with sulfuric acid added to a concentration of 48 mL / L, total amount 2000 mL) for 50°C, followed by immersion in the reducing solution for 5 minutes, and then rinsed with running water for 1 minute at 25°C for 3 minutes.

[0082] For the test pieces of each embodiment and comparative example, a dielectric constant tester (Keysight E5080B) was used to measure the dielectric loss tangent of the test piece at a frequency of 10 GHz using the cavity resonance method according to the GB / T1409-2006 standard, and evaluated according to the following standards: Good: dielectric loss tangent ≤ 0.001 at 10 GHz; Poor: dielectric loss tangent > 0.001 at 10 GHz.

[0083] 9. TCT Resistance: After peeling off the protective film from the "photosensitive resin film with carrier film and protective film", a laminating vacuum laminator (manufactured by Chih Sheng Industrial Co., Ltd., model "VL-M24") is used to laminate it onto a 1.0 mm thick copper-clad laminate under the conditions of 0.4 MPa lamination pressure, 60℃ lamination hot plate temperature, 30 seconds vacuum time, 30 seconds lamination time and ≤4 kPa air pressure to obtain a laminated board.

[0084] The resulting laminate was exposed to a UV LED light source (manufactured by Yuntong Technology Co., Ltd., model "UVLED Curing Box (365, 385, 395, 405 nm four-wave hybrid type)") at a dose of 500 mJ / cm² through a polyethylene terephthalate film. The PET carrier film was then peeled off, followed by development with a 1% Na₂CO₃ aqueous solution at 30°C (0.2 MPa jet pressure, 90 seconds) and rinsing with pure water (0.2 MPa jet pressure, 90 seconds). After removing the moisture, the laminate was heated at 180°C for 1 hour to form a permanent mask solder resist layer with an open pattern on the copper-clad laminate, thus obtaining the test board.

[0085] The test plate was subjected to temperature cycling tests: one cycle consisted of -65℃ (30 minutes) and 150℃ (30 minutes). After 1000 cycles, the test plate was observed visually and under an optical microscope and evaluated according to the following criteria: Good: No cracks were found after 1000 cycles; Poor: Cracks were confirmed to have appeared after 1000 cycles.

[0086] The results are recorded in Table 3.

[0087] Table 3

[0088] As shown in Table 3, Examples 1-5 of this invention all employ organic peroxides (such as DCP, BIPB, DTBP, etc.) with specific half-life temperatures (140~200℃ for a 1-minute half-life) as thermal free radical initiators in the resin composition to promote the synergistic thermosetting reaction between acid-modified unsaturated epoxy resin (A), thermosetting resin (C, such as bismaleimide BMI), and other multifunctional monomers. This design ensures that the material remains stable during room temperature storage and the pre-drying stage of the coating (typically 70-120℃ / 4 minutes) and does not prematurely initiate crosslinking reactions.

[0089] In contrast, Comparative Example 1 used TMPO, an organic peroxide with a low decomposition temperature (1-minute half-life: 124.3°C), whose decomposition temperature is lower than the pre-drying process temperature. Therefore, during the pre-drying process after coating, TMPO partially decomposed to generate active free radicals, causing premature local cross-linking of the resin system. This not only consumed the effective active ingredients but also reduced the reactivity during subsequent photocuring and thermal curing, thus significantly affecting the usability and developability of the composition.

[0090] Comparative Example 2, despite using a different type of photopolymerizable resin but still employing TMPO as the initiator, still exhibited the same problem, further confirming that the insufficient thermal stability of the initiator was the root cause, rather than the resin type. This highlights the crucial role of selecting a peroxide with an appropriate half-life temperature for process compatibility.

[0091] Comparative Example 3 attempted to alleviate the premature reaction problem by reducing the amount of TMPO (from 3.0 parts to 0.5 parts), but failed to effectively improve performance. The reason is that even a small amount of low-temperature peroxide decomposes during the pre-drying stage, causing local network formation and disrupting uniformity; at the same time, the excessively low initiator dosage is insufficient to support adequate subsequent thermal curing, resulting in insufficient overall crosslinking density, and ultimately failing to meet reliability requirements.

[0092] Comparative Example 4 completely abandoned organic peroxides and instead used imidazole compounds (such as 2P4MZ) as thermosetting accelerators. However, imidazoles mainly catalyze epoxy-phenolic or epoxy-amine reactions, and have low initiation efficiency for resin systems such as allyl resins and bismaleimide (BMI) that rely on free radical curing mechanisms, resulting in incomplete thermosetting. The consequences are: although the surface smoothness may be better, the peel strength is unsatisfactory, and there is a risk of failure under humid heat bias conditions (B-HAST) and severe temperature cycling (TCT), resulting in overall unsatisfactory reliability.

[0093] In summary, this invention achieves an excellent balance between the stability of the resin system during processing and its final cured performance by selecting a highly thermally stable organic peroxide (1-minute half-life 140-200°C). Only under these conditions can good usability, developability, high bond strength, and excellent environmental durability (B-HAST, TCT) be achieved simultaneously, thus verifying that the technical solution regarding component (G) and its dosage range possesses outstanding substantive features and significant progress.

[0094] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection of the claims.

Claims

1. A photosensitive resin composition, characterized in that, include: (A) Acid-modified unsaturated epoxy resin, (B) Thermosetting resin, (C) Photoinitiator, (D) Photopolymerizable compound, (E) Inorganic filler, (G) Organic peroxide.

2. The photosensitive resin composition according to claim 1, characterized in that, The organic peroxide (G) has a half-life temperature of 140~200°C within 1 minute.

3. The photosensitive resin composition according to claim 1 or 2, characterized in that, Based on parts by weight, the following are included: (A) 100 parts (based on resin solids), (B) 40-60 parts, (C) 0.2-2.0 parts, (D) 30-50 parts, (E) 100-400 parts, and (G) 0.1-5 parts.

4. The photosensitive resin composition according to claim 1 or 2, characterized in that, The (A) acid-modified unsaturated epoxy resin includes at least one of an acid-modified unsaturated epoxy resin having a bisphenol A backbone, an acid-modified unsaturated epoxy resin having a bisphenol F backbone, and an acid-modified unsaturated epoxy resin having an alicyclic backbone. Preferably, the structural formula of the alicyclic skeleton is as follows: ; Among them, R A1 It is a C1~C12 alkyl group, R A1 Replace at any position in the alicyclic framework; m 1 Integers from 0 to 6; * indicates a connection point with other structures.

5. The photosensitive resin composition according to claim 1 or 2, characterized in that, The thermosetting resin (B) includes at least one of epoxy resin, allyl resin, and unsaturated imide resin; Preferably, the photoinitiator (C) comprises an acylphosphine oxide-based photoinitiator and / or an oxime ester-based photoinitiator; Preferably, the (D) photopolymerizable compound is a photopolymerizable compound that has two or more unsaturated groups and is liquid at 25°C or a photopolymerizable compound that is solid at 25°C.

6. The photosensitive resin composition according to claim 1 or 2, characterized in that, The inorganic filler (E) comprises spherical silica with an average particle size of 0.6 μm.

7. The photosensitive resin composition according to claim 1 or 2, characterized in that, The photosensitive resin composition also includes 0.1 to 1.5 parts of pigment.

8. A photosensitive element, characterized in that, It includes a support and a photosensitive resin layer disposed on the surface of the support; The photosensitive resin layer is formed from the photosensitive resin composition according to any one of claims 1 to 7.

9. A printed circuit board, characterized in that, It includes the insulating layer formed by exposure, development and curing of the photosensitive element as described in claim 8.

10. A semiconductor package, characterized in that, Includes semiconductor components and the printed circuit board as described in claim 9.

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