Photosensitive resin composition, photosensitive element, printed wiring board, and production method for printed wiring board

Abstract

A photosensitive resin composition for a permanent resist according to the present disclosure contains (A) an acid-modified vinyl group-containing resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silicone compound, wherein (E) the silicone compound has at least one first group selected from the group consisting of ethylenically unsaturated groups, alkyl groups, and aryl groups, and at least one second group selected from the group consisting of alkoxy groups and silanol groups.

Description

Photosensitive resin composition, photosensitive element, printed circuit board, and method for manufacturing a printed circuit board.

[0001] This disclosure relates to a photosensitive resin composition for permanent resists, a photosensitive element, a printed circuit board, and a method for manufacturing a printed circuit board.

[0002] In the field of printed circuit boards (PCBs), permanent resist is formed on the PCBs. Permanent resist plays a role in preventing corrosion of the conductor layer and maintaining electrical insulation between conductor layers during the use of the PCB. In recent years, permanent resist has also taken on the role of a solder resist film in processes such as flip-chip mounting and wire bonding mounting of semiconductor elements onto PCBs via solder, preventing solder from adhering to unwanted areas of the conductor layer on the PCB.

[0003] Permanent resists are manufactured, for example, by screen printing using a thermosetting resin composition, or by a photographic method using a photosensitive resin composition. In semiconductor package substrates such as BGAs (ball grid arrays) and CSPs (chip-size packages) mounted on electronic components, it is necessary to remove the permanent resist from the bonding area in order to (1) flip-chip mount semiconductor elements on the semiconductor package substrate via solder, (2) wire-bond semiconductor elements to the semiconductor package substrate, and (3) solder bond the semiconductor package substrate to the motherboard substrate. For image formation of the permanent resist, a photographic method is used in which a photosensitive resin composition is applied, dried, and then selectively irradiated with active light such as ultraviolet light to cure it, and only the unirradiated areas are removed by development to form the image. Because the photographic method is suitable for mass production due to its ease of work, it is widely used in the electronic materials industry for image formation of photosensitive materials (see, for example, Patent Document 1).

[0004] Japanese Patent Publication No. 2013-156642

[0005] In response to the increasing density of printed circuit boards, permanent resists also require even higher performance. In particular, the demands for crack resistance and the formation of fine patterns are increasing year by year, making it crucial to achieve a high level of compatibility between these characteristics.

[0006] Therefore, the object of this disclosure is to provide a photosensitive resin composition capable of forming a permanent resist with excellent crack resistance and resolution, a photosensitive element using the photosensitive resin composition, a printed circuit board, and a method for manufacturing a printed circuit board.

[0007] One aspect of the present disclosure relates to the following photosensitive resin composition, photosensitive element, printed circuit board, and method for manufacturing a printed circuit board: [1] A photosensitive resin composition for permanent resist, comprising (A) an acid-modified vinyl group-containing resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silicone compound, wherein the (E) silicone compound is a compound having at least one first group selected from the group consisting of ethylenically unsaturated groups, alkyl groups, and aryl groups, and at least one second group selected from the group consisting of alkoxy groups and silanol groups. [2] The photosensitive resin composition according to [1], wherein the content of the (E) silicone compound is 0.1 to 15% by mass based on the total solid content of the photosensitive resin composition. [3] The photosensitive resin composition according to [1] or [2], wherein the (D) inorganic filler comprises an inorganic filler having a refractive index of 1.520 to 1.680. [4] The photosensitive resin composition according to any one of [1] to [3] above, wherein the (D) inorganic filler comprises composite particles of silica and a metal oxide other than silica. [5] The photosensitive resin composition according to [4] above, wherein the composite particles comprises silica-titania composite particles. [6] The photosensitive resin composition according to any one of [1] to [5] above, wherein the content of the (D) inorganic filler is 40 to 85% by mass based on the total amount of solids in the photosensitive resin composition. [7] The photosensitive resin composition according to any one of [1] to [6] above, further comprising (F) a thermosetting resin. [8] A photosensitive element comprising a support film and a photosensitive layer formed on the support film, wherein the photosensitive layer comprises the photosensitive resin composition according to any one of [1] to [7] above. [9] A printed circuit board comprising a permanent resist containing a cured product of the photosensitive resin composition according to any one of [1] to [7] above.

[10] A method for manufacturing a printed circuit board, comprising the steps of: forming a photosensitive layer on a substrate using a photosensitive resin composition according to any one of [1] to [7] above; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist.

[11] A method for manufacturing a printed circuit board, comprising the steps of: forming a photosensitive layer on a substrate using the photosensitive element described in [8] above; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist.

[0008] According to this disclosure, a photosensitive resin composition capable of forming a permanent resist with excellent crack resistance and resolution, a photosensitive element using the photosensitive resin composition, a printed circuit board, and a method for manufacturing a printed circuit board can be provided.

[0009] Figure 1 is a schematic cross-sectional view showing a photosensitive element according to this embodiment.

[0010] The following describes one embodiment of this disclosure in detail, but this disclosure is not limited thereto. In the following embodiment, the components (including elemental steps, etc.) are not essential unless they are clearly essential in principle, as specifically indicated. The same applies to numerical values ​​and their ranges, and this does not unduly limit this disclosure.

[0011] In this disclosure, the term "layer" includes not only structures that are formed across the entire surface when observed in a plan view, but also structures that are formed in only a portion of the surface. In this disclosure, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, as long as the intended purpose of that process is achieved.

[0012] In this disclosure, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit of one stage of the numerical range may be replaced with the upper or lower limit of another stage of the numerical range. Also, in numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. In this disclosure, "A or B" means that either A or B is included, or both are included. Unless otherwise specified, the materials exemplified below may be used individually or in combination of two or more. In this disclosure, the content of each component in a composition means the total amount of multiple substances present in the composition if there are multiple substances corresponding to each component in the composition, unless otherwise specified.

[0013] In this disclosure, "solids" refers to the non-volatile components of a photosensitive resin composition, excluding volatile substances such as water and diluents. It includes components that remain without evaporating or volatilizing when the resin composition is dried, and also includes components that are liquid, syrup-like, or waxy at room temperature (25°C, the same applies hereinafter).

[0014] [Photosensitive Resin Composition] The photosensitive resin composition according to this embodiment contains (A) an acid-modified vinyl group-containing resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silicone compound. In the photosensitive resin composition according to this embodiment, the (E) silicone compound includes a compound having at least one first group selected from the group consisting of ethylenically unsaturated groups, alkyl groups, and aryl groups, and at least one second group selected from the group consisting of alkoxy groups and silanol groups.

[0015] The photosensitive resin composition according to this embodiment contains each of the above components and also contains a specific silicone compound having the first and second groups, thereby forming a permanent resist with excellent crack resistance (crack resistance during thermal shock testing) and resolution. The inventors speculate that the reason for this effect is as follows: In thermal shock testing, particularly strong stress tends to occur in the permanent resist in the low-temperature range, making it prone to cracking. In contrast, by adding the specific silicone compound, the glass transition temperature (Tg) of the permanent resist can be shifted to the lower temperature side, thereby providing cold resistance, and the stress generated in the permanent resist in the low-temperature range is mitigated. Furthermore, good resolution can be obtained when using the specific silicone compound.

[0016] The photosensitive resin composition according to this embodiment is a negative-type photosensitive resin composition. The components included in the photosensitive resin composition according to this embodiment will be described in detail below.

[0017] <Component (A): Acid-modified vinyl group-containing resin> The photosensitive resin composition according to this embodiment contains an acid-modified vinyl group-containing resin as component (A). The acid-modified vinyl group-containing resin is not particularly limited as long as it has a vinyl group which is a photopolymerizable ethylenically unsaturated bond and an alkali-soluble acidic group.

[0018] Examples of groups having an ethylenically unsaturated bond in component (A) include vinyl groups, allyl groups, propargyl groups, butenyl groups, ethynyl groups, phenylethynyl groups, maleimide groups, nadiimide groups, and (meth)acryloyl groups. Among these, from the viewpoint of reactivity and resolution, the group having an ethylenically unsaturated bond may be a (meth)acryloyl group. Examples of acidic groups having component (A) include carboxyl groups, sulfol groups, and phenolic hydroxyl groups. Among these, from the viewpoint of resolution, the acidic group may be a carboxyl group.

[0019] The component (A) may be an acid-modified vinyl group-containing epoxy derivative obtained by reacting (a) an epoxy resin (hereinafter also referred to as “component (a)”) with (b) an ethylenically unsaturated group-containing organic acid (hereinafter also referred to as “component (b)”) to form a resin (A') (hereinafter also referred to as “component (A')”), and then reacting the resin (A') with (c) a saturated group- or unsaturated group-containing polybasic acid anhydride (hereinafter also referred to as “component (c)”).

[0020] Examples of the acid-modified vinyl group-containing epoxy derivative include acid-modified epoxy (meth)acrylate. Acid-modified epoxy (meth)acrylate is a resin obtained by acid-modifying epoxy (meth)acrylate, which is a reaction product of component (a) and component (b), with component (c). As the acid-modified epoxy (meth)acrylate, for example, an addition reaction product obtained by adding a saturated or unsaturated polybasic acid anhydride to an esterified product obtained by reacting an epoxy resin with a vinyl group-containing monocarboxylic acid can be used.

[0021] (Epoxy resin (a)) Examples of component (a) include epoxy resins having an alicyclic skeleton, novolak-type epoxy resins, and bisphenol-type epoxy resins. Examples of novolak-type epoxy resins include bisphenol novolak-type epoxy resins such as bisphenol A novolak-type epoxy resin, bisphenol F novolak-type epoxy resin, and bisphenol S novolak-type epoxy resin; phenol novolak-type epoxy resin, cresol novolak-type epoxy resin, biphenyl novolak-type epoxy resin, naphthol novolak-type epoxy resin, and the like. Examples of bisphenol-type epoxy resins include bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and bisphenol S-type epoxy resin.

[0022] From the viewpoints of crack resistance and resolution, the component (a) may use an aromatic epoxy resin. The aromatic epoxy resin is an epoxy resin having an aromatic ring in the molecule. From the viewpoints of crack resistance and resolution, the aromatic epoxy resin preferably uses at least one selected from the group consisting of bisphenol F novolak type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, and biphenyl type epoxy resin. More preferably, at least one selected from the group consisting of phenol novolak type epoxy resin, cresol novolak type epoxy resin, and biphenyl type epoxy resin is used. Even more preferably, at least one selected from the group consisting of cresol novolak type epoxy resin and biphenyl type epoxy resin is used.

[0023] (Ethylenically unsaturated group-containing organic acid (b)) As the component (b), for example, acrylic acid; acrylic acid derivatives such as dimers of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, α-cyanocinnamic acid; half ester compounds which are reaction products of hydroxyl group-containing (meth)acrylate and dibasic acid anhydride; and half ester compounds which are reaction products of vinyl group-containing monoglycidyl ether or vinyl group-containing monoglycidyl ester and dibasic acid anhydride can be mentioned. The component (b) can be used alone or in combination of two or more.

[0024] The half ester compound can be obtained, for example, by reacting a hydroxyl group-containing (meth)acrylate, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester with a dibasic acid anhydride.

[0025] Examples of hydroxyl group-containing (meth)acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, trimethylolpropanedi(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and glycidyl (meth)acrylate.

[0026] Examples of dibasic acid anhydrides include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride.

[0027] Component (A'), obtained by reacting component (a) and component (b), has a hydroxyl group formed by a ring-opening addition reaction between the epoxy group of component (a) and the carboxyl group of component (b). By further reacting component (A') with component (c), an acid-modified vinyl group-containing epoxy resin is obtained in which the hydroxyl groups of component (A') (including the hydroxyl groups originally present in component (a)) and the acid anhydride group of component (c) are semi-esterified.

[0028] (Polybasic acid anhydride (c)) Examples of component (c) include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride. Among these, from the viewpoint of resolution, component (c) may be tetrahydrophthalic anhydride. Component (c) may be used alone or in combination of two or more.

[0029] If necessary, as component (a), for example, a hydrogenated bisphenol A epoxy resin may be used in combination, or a styrene-maleic acid-based resin such as a hydroxyethyl (meth)acrylate modified product of a styrene-maleic anhydride copolymer may be used in combination.

[0030] (A) Component can be synthesized by known methods, but commercially available products may also be used. Specific examples of commercially available products include, for example, acid-modified cresol novolac type epoxy acrylates such as CCR-1291H, CCR-1235, CCR-1373H, and CCR-1374H (all manufactured by Nippon Kayaku Co., Ltd., trade names); acid-modified biphenyl type epoxy acrylates such as ZCR-1569H, ZCR-1601H, ZCR-1797H, and ZCR-1798H (all manufactured by Nippon Kayaku Co., Ltd., trade names); acid-modified bisphenol F type epoxy acrylates such as ZFR-1401H, ZFR-1491H, and ZFR-1533H (all manufactured by Nippon Kayaku Co., Ltd., trade names); and acid-modified bisphenol A type epoxy acrylates such as ZAR-1035 and ZAR-2000 (both manufactured by Nippon Kayaku Co., Ltd., trade names). These can be used individually or in combination of two or more types.

[0031] The acid value of component (A) may be 20 mg KOH / g or more, 30 mg KOH / g or more, 40 mg KOH / g or more, or 50 mg KOH / g or more, and may be 200 mg KOH / g or less, 180 mg KOH / g or less, 150 mg KOH / g or less, 100 mg KOH / g or less, 80 mg KOH / g or less, or 70 mg KOH / g or less. When the acid value of component (A) is 20 mg KOH / g or more, the photosensitive resin composition tends to have excellent solubility in dilute alkaline solutions. When the acid value of component (A) is 200 mg KOH / g or less, the electrical properties of the permanent resist tend to be improved. Two or more components (A) with different acid values ​​may be used in combination, in which case it is preferable that the weighted average acid value of the acid values ​​of the two or more components (A) be within any of the above ranges.

[0032] The acid value can be measured using the following procedure. First, 1 g of component (A), which is the substance to be measured for acid value, is accurately weighed, and then 30 g of acetone is added to component (A) to uniformly dissolve it and obtain a solution. Next, an appropriate amount of phenolphthalein, which is an indicator, is added to the solution, and then titration is performed using a 0.1 N KOH (potassium hydroxide) aqueous solution. The acid value is determined by calculating the mass (in mg) of KOH required to neutralize the acetone solution of component (A).

[0033] (A) The weight-average molecular weight (Mw) of component is not particularly limited, but may be 600 or more, 800 or more, 1000 or more, 3000 or more, 4000 or more, or 5000 or more, from the viewpoint of resolution, adhesion, heat resistance, and insulation reliability, and may be 30000 or less, 25000 or less, 18000 or less, 15000 or less, or 10000 or less.

[0034] Mw can be measured by gel permeation chromatography (GPC). For example, Mw can be measured under the GPC conditions described below, and the value converted using a calibration curve for standard polystyrene can be used as the Mw value. A set of five samples ("PStQuick MP-H" and "PStQuick B," manufactured by Tosoh Corporation) can be used as the standard polystyrene to create the calibration curve. GPC instrument: High-speed GPC instrument "HCL-8320GPC" (manufactured by Tosoh Corporation) Detector: Differential refractometer or UV detector (manufactured by Tosoh Corporation) Column: TSKgel SuperMultipore HZ-H column (column length: 15 cm, column inner diameter: 4.6 mm) (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran (THF) Measurement temperature: 40°C Flow rate: 0.35 mL / min Sample concentration: 10 mg / THF 5 mL Injection volume: 20 μL

[0035] (A) The content of component (A) may be 5% by mass or more, 10% by mass or more, or 15% by mass or more, based on the total solid content of the photosensitive resin composition, from the viewpoint of the heat resistance, electrical properties and chemical resistance of the permanent resist, and may also be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 25% by mass or less.

[0036] <Component (B): Photopolymerizable compound> The photosensitive resin composition according to this embodiment contains a photopolymerizable compound (excluding component (A) described above) as component (B). Component (B) is not particularly limited as long as it is a compound having a functional group that exhibits photopolymerizability. Examples of functional groups that exhibit photopolymerizability include groups having an ethylenically unsaturated bond, such as vinyl group, allyl group, propargyl group, butenyl group, ethynyl group, phenylethynyl group, maleimide group, nadiimide group, and (meth)acryloyl group.

[0037] (B) Component examples include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; mono- or di(meth)acrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, and polyethylene glycol; (meth)acrylamide compounds such as N,N-dimethyl(meth)acrylamide and N-methylol(meth)acrylamide; aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate; hexanediol, trimethylolpropane, pentaerythritol, and ditrimethylolpropane. Examples include polyhydric alcohols such as dipentaerythritol and tris-hydroxyethyl isocyanurate, or polyhydric (meth)acrylates of ethylene oxide or propylene oxide adducts thereof; (meth)acrylate compounds of ethylene oxide or propylene oxide adducts of phenolic compounds such as phenoxyethyl (meth)acrylate and polyethoxydi(meth)acrylate of bisphenol A; (meth)acrylates of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine (meth)acrylate. Component (B) can be used individually or in combination of two or more.

[0038] From the viewpoint of insulation reliability, component (B) may include a (meth)acrylic compound having (meth)acryloyl groups. The (meth)acrylic compound may be a monofunctional (meth)acrylic compound or a polyfunctional (meth)acrylic compound. A "monofunctional (meth)acrylic compound" means a compound in which the total number of acryloyl groups and methacryloyl groups in one molecule is 1, and a "polyfunctional (meth)acrylic compound" means a compound in which the total number of acryloyl groups and methacryloyl groups in one molecule is 2 or more. From the viewpoint of superior insulation reliability, the (meth)acrylic compound may include a (meth)acrylic compound with four or more functions. Examples of (meth)acrylic compounds with four or more functions include pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, ethoxylated propoxylated pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, and propoxylated dipentaerythritol hexa(meth)acrylate. These can be used individually or in combination of two or more.

[0039] The content of component (B) may be 1.0% by mass or more, 2.0% by mass or more, 3.0% by mass or more, or 3.5% by mass or more, based on the total amount of solids in the photosensitive resin composition, and may also be 7.0% by mass or less, 6.0% by mass or less, 5.0% by mass or less, or 4.5% by mass or less.

[0040] <Component (C): Photopolymerization Initiator> The photosensitive resin composition according to this embodiment contains a photopolymerization initiator as component (C). Component (C) is not particularly limited as long as it can polymerize components (A) and (B). Component (C) may be used alone or in combination of two or more types.

[0041] (C) Component includes, for example, acetophenone compounds such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-methyl-4'-(methylthio)-2-morpholinopropiophenone, N,N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-amylanthraquinone, 2-amylanthraquinone Examples include anthraquinone compounds such as noanthraquinone; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and oxime ester compounds such as 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone-1-(O-acetyl oxime), and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl) oxime].

[0042] The content of component (C) is not particularly limited, but may be 0.20 to 10% by mass, 0.25 to 5% by mass, or 0.30 to 3% by mass, based on the total solid content of the photosensitive resin composition.

[0043] <Component (D): Inorganic Filler> The photosensitive resin composition according to this embodiment further contains an inorganic filler as component (D) from the viewpoint of low thermal expansion coefficient, heat resistance and flame retardancy. Component (D) may be an untreated filler or a surface-treated filler. A surface-treated filler can be obtained by treating the surface of the inorganic filler with a surface treatment agent. Component (D) may be used alone or in combination of two or more types.

[0044] (D) Component is not particularly limited, but for example, silica (SiO ２ ), alumina (Al ２O ３ ), titania (TiO ２ ), tantalum oxide (Ta ２ O ５ ), zirconia (ZrO ２ ), silicon nitride (Si ３ N ４ ), barium titanate (BaO・TiO ２ ), barium carbonate (BaCO ３ ), magnesium carbonate (MgCO ３ ), aluminum hydroxide (Al(OH) ３ ), magnesium hydroxide (Mg(OH) ２ ), lead titanate (PbO・TiO ２ ), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga ２ O ３ ), spinel (MgO・Al ２ O ３ ), mullite (3Al ２ O ３ ・2SiO ２ ), cordierite (2MgO・2Al ２ O ３ / 5SiO ２ ), talc (3MgO・4SiO ２ ・H ２ O), aluminum titanate (TiO ２ ・Al ２ O ３ ), yttria-containing zirconia (Y ２ O ３ ・ZrO ２ ), barium silicate (BaO・8SiO ２ ), boron nitride (BN), calcium carbonate (CaCO ３ ), barium sulfate (BaSO ４ ), calcium sulfate (CaSO ４ ), zinc oxide (ZnO), magnesium titanate (MgO・TiO ２ ), hydrotalcite, mica, calcined kaolin, and carbon (C) are included.

[0045] From the viewpoint of achieving superior resolution, composite particles of two or more metal oxides may be used as component (D). Examples of such composite particles include composite particles of silica and a metal oxide other than silica (hereinafter also referred to as "component (D1)").

[0046] Examples of metal oxides other than silica that constitute component (D1) include titania, zirconia, alumina, boron oxide, calcium oxide, yttria, nickel oxide, hafnium oxide, niobium oxide, tantalum oxide, and zinc oxide. Among these, from the viewpoint of superior resolution, the metal oxide other than silica may be titania. In other words, component (D1) may be silica-titania composite particles.

[0047] The volume-average particle size of component (D) is not particularly limited, but may be 0.01 to 20 μm, 0.1 to 10 μm, 0.2 to 1 μm, or 0.25 to 0.7 μm. The volume-average particle size of component (D) is the average particle size when dispersed in the photosensitive resin composition, and is a value obtained by measuring it using the following procedure.

[0048] After diluting the photosensitive resin composition 1000 times with a solvent (methyl ethyl ketone), the particle size distribution of the particles dispersed in the solvent is measured using a submicron particle analyzer (Beckman Coulter, Inc., product name: N5) in accordance with the international standard ISO 13321, with a refractive index of 1.38. The particle diameter at 50% of the cumulative value (by volume) in the particle size distribution is defined as the volume-average particle diameter. Component (D) contained in the photosensitive layer formed using the photosensitive resin composition can also be measured using the same procedure.

[0049] The refractive index of component (D) is not particularly limited, but may be 1.520 to 1.680, 1.530 to 1.640, or 1.535 to 1.600. The refractive index can be measured, for example, by the immersion method using the following procedure. First, solvents with different refractive indices (1-bromonaphthalene, liquid paraffin) are mixed in any proportion to prepare several mixed solvents with different refractive indices. Next, an inorganic filler is added to each mixed solvent to prepare a dispersion. The transparency of the dispersions is visually compared, and the refractive index of the mixed solvent used for the dispersion with the highest transparency is taken as the refractive index of the inorganic filler. If the refractive index of component (D) is within the above range, the refractive index difference between the resin and component (D) can be reduced, and light scattering at the interface between the resin and component (D) can be suppressed. As a result, resolution can be improved.

[0050] (D) The shape of component can be spherical, crushed, or the like. Among these, a spherical shape is preferred from the viewpoint of suppressing the diffusion of energy rays incident on the photosensitive layer containing the photosensitive resin composition during exposure and improving resolution. Here, "spherical" means that the circularity calculated by the following formula using the area and perimeter measured from the photograph of the target particle is 90 or more. Circularity = {4π × (area) ÷ (perimeter)} ２} × 100

[0051] Particles can be observed, for example, using a scanning electron microscope (SEM) at 5000x magnification, and the average area and average perimeter of any 10 particles can be used as the area and perimeter values ​​in the above formula, respectively.

[0052] The content of component (D) may be 40% by mass or more, 50% by mass or more, or 60% by mass or more, based on the total solid content of the photosensitive resin composition, and may also be 85% by mass or less, 80% by mass or less, or 70% by mass or less.

[0053] <Component (E): Silicone Compound> The photosensitive resin composition according to this embodiment contains a silicone compound as component (E). The silicone compound that is component (E) is a compound having a siloxane bond. Component (E) has at least one first group selected from the group consisting of ethylenically unsaturated groups, alkyl groups, and aryl groups, and at least one second group selected from the group consisting of alkoxy groups and silanol groups. Component (E) may be used alone or in combination of two or more. By containing component (E) in the photosensitive resin composition, a permanent resist with excellent crack resistance and resolution can be formed.

[0054] The first group may be a side-chain functional group, a terminal functional group, or both. From the viewpoint of further improving crack resistance, it is preferable that component (E) has at least the first group as a side-chain functional group.

[0055] In the first group, examples of ethylenically unsaturated groups include (meth)acryloyl groups and vinyl groups. Among these, vinyl groups are preferred as the ethylenically unsaturated group from the viewpoint of further improving crack resistance.

[0056] In the first group, the alkyl group is not particularly limited, but from the viewpoint of further improving crack resistance, it is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 1 to 2 carbon atoms. In this embodiment, the alkyl group that is the first group is an alkyl group that does not constitute the alkoxy group that is the second group. That is, the alkoxy group is classified only as the second group, and the alkyl group in the alkoxy group is not classified as the first group.

[0057] In the first group, examples of aryl groups include phenyl groups, naphthyl groups, and biphenyl groups. Among these, the aryl group is preferably a phenyl group from the viewpoint of further improving crack resistance.

[0058] The first group may include at least one selected from the group consisting of ethylenically unsaturated groups and aryl groups, may include at least an aryl group, or may include both an ethylenically unsaturated group and an aryl group, from the viewpoint of further improving crack resistance.

[0059] The second group may be a side-chain functional group, a terminal functional group, or both. From the viewpoint of further improving crack resistance, component (E) preferably has the second group as at least a side-chain functional group, and more preferably has the second group as both a side-chain functional group and a terminal functional group.

[0060] In the second group, the alkoxy group is not particularly limited, but from the viewpoint of further improving crack resistance, it is preferably an alkoxy group having 1 to 4 carbon atoms, and more preferably an alkoxy group having 1 to 2 carbon atoms.

[0061] The second group may contain at least an alkoxy group, or both an alkoxy group and a silanol group, from the viewpoint of further improving crack resistance. Furthermore, at least one of the terminal functional groups of component (E) may be an alkoxy group, from the viewpoint of further improving crack resistance.

[0062] The content of the second group in component (E) may be 5 to 50% by mass or 10 to 30% by mass based on the total amount of component (E), from the viewpoint of further improving crack resistance.

[0063] Component (E) may be a silicone resin, a silicone oligomer, a silicone oil, etc. Among these, component (E) is preferably a silicone resin or a silicone oligomer from the viewpoint of further improving crack resistance.

[0064] The weight-average molecular weight (Mw) of component (E) is not particularly limited, but from the viewpoint of further improving crack resistance, it may be 3000 or less, 2000 or less, or 1000 or less, or 100 or more, or 200 or more. Mw can be measured in the same way as the Mw of component (A).

[0065] The Tg of component (E) is not particularly limited, but from the viewpoint of further improving crack resistance, it may be -10°C or below, -20°C or below, or -30°C or below.

[0066] (E) Component includes silicone oligomers such as KR-511, KC-89S, X-40-9227, X-40-9296, KR-513, KR-516, KR-515, KR-500, X-40-9225, X-40-9246, X-40-9250, KR-401N, KR-510, KR-213 (all manufactured by Shin-Etsu Chemical Co., Ltd., product names), KR-112, KR-21 1. Silicone resins such as KR-212, KR-271, KR-220L, KR-220LP, KR-242A, KR251, X-40-2406M, KR-255, KR-282, KR-300, KR-311, X-48-1030, X-40-2667A, X-40-2756, and KR-480 (all manufactured by Shin-Etsu Chemical Co., Ltd., product names) are commercially available.

[0067] The content of component (E) may be 1% by mass or more, 3% by mass or more, 5% by mass or more, or 8% by mass or more, based on the total content of components (A) and (B), from the viewpoint of further improving crack resistance, and may be 20% by mass or less, 15% by mass or less, 13% by mass or less, or 10% by mass or less, from the viewpoint of further improving resolution. The content of component (E) may be 1% by mass or more and 20% by mass or less, 3% by mass or more and 15% by mass or less, 5% by mass or more and 13% by mass or less, or 8% by mass or more and 10% by mass or less, based on the total content of components (A) and (B), from the viewpoint of achieving a higher level of both crack resistance and resolution.

[0068] The photosensitive resin composition according to this embodiment may or may not contain other silicone compounds that do not correspond to component (E) (hereinafter also referred to as "component (E')"), as long as they do not impair the effects of component (E). The content of component (E') may be 0.1% by mass or less, 0.05% by mass or less, 0.01% by mass or less, or 0% by mass, based on the total solid content of the photosensitive resin composition.

[0069] <Component (F): Thermosetting resin> The photosensitive resin composition according to this embodiment may further contain a thermosetting resin as component (F) from the viewpoint of heat resistance, adhesion, and insulation reliability of the formed cured film (permanent resist). Component (F) may be used alone or in combination of two or more types.

[0070] Examples of component (F) include epoxy resin, phenolic resin, unsaturated imide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, triazine resin, and melamine resin. Among these, epoxy resin may be used as component (F) from the viewpoint of superior heat resistance, adhesion, and insulation reliability.

[0071] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, novolac type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, hydantoin type epoxy resin, triglycidyl isocyanurate, and bixylenol type epoxy resin.

[0072] Component (F) may include, from the viewpoint of developability and insulation reliability, a first polyfunctional epoxy resin (F1) with a molecular weight of less than 380 (hereinafter also referred to as "component (F1)") and a second polyfunctional epoxy resin (F2) with a molecular weight of 380 or more (hereinafter also referred to as "component (F2)"). Component (F1) may be used alone or in combination of two or more types. Component (F2) may be used alone or in combination of two or more types.

[0073] The molecular weight of component (F1) may be 100 or more and less than 380, or 200 or more and less than 380, and the molecular weight of component (F2) may be 380 to 1200, or 380 to 500.

[0074] The content of components (F1) and (F2) in component (F) is not particularly limited, but from the viewpoint of developability, the mass ratio of the content of component (F1) to the content of component (F2) (content of component (F1) / content of component (F2)) may be 1.0 to 5.0, 2.0 to 4.5, 3.0 to 4.0, or 3.5 to 4.0.

[0075] The content of component (F) may be 2 to 30% by mass, 5 to 25% by mass, or 8 to 20% by mass, based on the total solid content of the photosensitive resin composition. When the content of component (F) is within the above range, the heat resistance of the formed cured film can be further improved while maintaining good developability.

[0076] <Component (G): Photosensitizer> The photosensitive resin composition of this embodiment may further contain a photosensitizer as component (G). By containing component (G) in the photosensitive resin composition, the absorption wavelength of the active light used for exposure can be effectively utilized.

[0077] (G) Examples of components include benzophenone compounds such as 4,4'-bis(diethylamino)benzophenone; thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; phosphine compounds such as triphenylphosphine; toluidine compounds such as N,N-dimethyltoluidine; anthracene compounds such as 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, and 2-ethyl-9,10-diethoxyanthracene; perylene compounds; coumarin compounds; pyrarisone compounds; oxazole compounds; thiazole compounds, benzoxazole compounds; thiazole compounds; triazole compounds; stilbene compounds; triazine compounds; thiophene compounds; naphthalimide compounds; and triarylamine compounds.

[0078] From the viewpoint of maintaining a good via shape, component (G) may be at least one selected from 2,4-dimethylthioxanthone and 2,4-diethylthioxanthone.

[0079] The content of component (G) may be 0.01 to 5.0% by mass, 0.02 to 3.0% by mass, 0.03 to 1.0% by mass, 0.04 to 0.5% by mass, or 0.05 to 0.35% by mass, based on the total solid content of the photosensitive resin composition.

[0080] <Component (H): Polymerization Inhibitor> The photosensitive resin composition may further contain a polymerization inhibitor as component (H) from the viewpoint of suppressing polymerization in unexposed areas during resist pattern formation and further improving resolution. Examples of component (H) include catechol compounds (e.g., tert-butylcatechol such as 4-tert-butylcatechol) and hindered amines (e.g., 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl). Component (H) may be used alone or in combination of two or more.

[0081] The content of component (H) may be 0.01% by mass or more, 0.03% by mass or more, or 0.05% by mass or more, based on the total amount of components (A) and (B), and may also be 5.0% by mass or less, 3.0% by mass or less, 1.0% by mass or less, 0.50% by mass or less, or 0.10% by mass or less.

[0082] <Component (I): Coupling agent> The photosensitive resin composition according to this embodiment may further contain a coupling agent as component (I). Component (I) may be used alone or in combination of two or more types.

[0083] (I) The component is not particularly limited, but a silane coupling agent may be used. Examples of silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatetopropyltriethoxysilane.

[0084] The content of component (I) may be 0.01 to 5.0% by mass, 0.03 to 3.0% by mass, or 0.05 to 2.0% by mass, based on the total amount of solids in the photosensitive resin composition.

[0085] <Component (J): Pigment> The photosensitive resin composition according to this embodiment may further contain a pigment as component (J) from the viewpoint of improving the identifiability or appearance of the manufacturing apparatus. As component (J), a coloring agent that produces a desired color when concealing wiring (conductor patterns) can be used. Component (J) may be used alone or in combination of two or more types.

[0086] (J) Examples of components include phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, carbon black, and naphthalene black.

[0087] (J) The content of component (J) may be 0.01 to 5.0% by mass, 0.03 to 3.0% by mass, or 0.05 to 2.0% by mass, based on the total amount of solids in the photosensitive resin composition, from the viewpoint of making the manufacturing equipment easier to identify and better concealing the wiring.

[0088] <Other Components> The photosensitive resin composition according to this embodiment may be further mixed with various additives as needed. Examples of additives include curing accelerators such as melamine; thickeners such as bentonite and montmorillonite; defoaming agents such as silicone-based, fluorine-based, and vinyl resin-based agents; and flame retardants such as phosphorus-based phosphate compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters. These may be used individually or in combination of two or more.

[0089] The photosensitive resin composition according to this embodiment may be mixed with a diluent such as an organic solvent to adjust its viscosity. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; and esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate.

[0090] When a diluent is used, the content of the diluent in the photosensitive resin composition may be 10 to 50% by mass, 20 to 40% by mass, or 25 to 35% by mass. By setting the content of the diluent within the above ranges, the coatability of the photosensitive resin composition can be improved.

[0091] The photosensitive resin composition according to this embodiment can be prepared by uniformly mixing the above-mentioned components using a roll mill, bead mill, or the like.

[0092] [Photosensitive Element] The photosensitive element according to this embodiment comprises a support film and a photosensitive layer containing the above-described photosensitive resin composition. Figure 1 is a schematic cross-sectional view showing the photosensitive element according to this embodiment. As shown in Figure 1, the photosensitive element 1 comprises a support film 10 and a photosensitive layer 20 formed on the support film 10. The solid content of each component other than volatile substances in the photosensitive layer 20 may be within the numerical range of the solid content of each component in the above-described photosensitive resin composition.

[0093] The photosensitive element 1 can be manufactured, for example, by applying the photosensitive resin composition according to this embodiment onto the support film 10 using a known method such as reverse roll coating, gravure roll coating, comma coating, or curtain coating, and then drying the coating to form a photosensitive layer 20.

[0094] Examples of support films include polyester films such as polyethylene terephthalate and polybutylene terephthalate, and polyolefin films such as polypropylene and polyethylene. The thickness of the support film may be, for example, 5 to 100 μm. The thickness of the photosensitive layer may be, for example, 10 to 50 μm, 15 to 40 μm, or 20 to 30 μm.

[0095] The coating film can be dried using hot air drying, far-infrared radiation, or near-infrared radiation. The drying temperature may be 60-120°C, 70-110°C, or 80-100°C. The drying time may be 1-60 minutes, 2-30 minutes, or 3-20 minutes.

[0096] A protective film 30 covering the photosensitive layer 20 may be further provided on the photosensitive layer 20. The protective film 30 of the photosensitive element 1 can also be laminated on the side of the photosensitive layer 20 opposite to the side in contact with the support film 10. As the protective film 30, for example, a polymer film such as polyethylene or polypropylene may be used. The protective film may be the same film as the support film, or it may be a different film.

[0097] The refractive index of the cured product of the photosensitive resin composition and the cured product of the photosensitive layer according to this embodiment may be 1.550 or higher. A refractive index of 1.550 or higher in the cured product results in excellent resolution of the photosensitive resin composition and photosensitive layer according to this embodiment. While the reason for this is not entirely clear, it is presumed that when the refractive index of the cured product is 1.550 or higher, the diffusion of energy rays incident on the photosensitive layer during exposure is suppressed, thereby suppressing the hardening of the light-shielding portion. From a similar viewpoint, the refractive index of the cured product of the photosensitive resin composition and the cured product of the photosensitive layer according to this embodiment is preferably 1.550 to 1.680, more preferably 1.550 to 1.640, and even more preferably 1.550 to 1.600.

[0098] The refractive index of the cured product of the photosensitive resin composition and the cured product of the photosensitive layer can be measured, for example, by the following method. First, a photosensitive layer is formed on a silicon wafer using the photosensitive resin composition or a photosensitive element. Next, the photosensitive layer is exposed to 200 mJ / cm using a parallel light exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name "EXM-1201") with an ultra-high pressure mercury lamp as the light source. ２ The entire surface is exposed. When a photosensitive layer is formed on a silicon wafer using a photosensitive element, exposure may be performed from above the support film. In this case, the support film is peeled off and removed after exposure. Next, a matching solution is applied to the surface of the cured photosensitive layer, and the refractive index of the cured photosensitive layer on the silicon wafer is measured under the following conditions while in close contact with a prism. • Measurement device: Model 2010 / M PRISM COUPLER, manufactured by Metricon Corporation • Wavelength: 632.8 nm • Measurement temperature: 25°C • Measurement atmosphere: Air • Matching solution: IMMERSION LIQUID (nD=1.640), manufactured by Cargile Laboratories Inc.

[0099] [Printed Wiring Board] The printed wiring board according to this embodiment comprises a permanent resist containing a cured product of the photosensitive resin composition according to this embodiment.

[0100] The method for manufacturing a printed circuit board according to this embodiment comprises the steps of: forming a photosensitive layer on a substrate using the above-mentioned photosensitive resin composition or photosensitive element; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist. An example of each step will be described below.

[0101] First, a metal-clad laminate, such as a copper-clad laminate, is prepared as the substrate, and a photosensitive layer is formed on the substrate. When using a photosensitive resin composition, the photosensitive resin composition may be applied to the substrate by methods such as screen printing, spraying, roll coating, curtain coating, or electrostatic coating, and the formed coating film may be dried at 60 to 110°C to form the photosensitive layer. The thickness of the coating film may be 10 to 200 μm, 15 to 150 μm, 20 to 100 μm, or 23 to 50 μm. When using a photosensitive element, the photosensitive layer may be formed by thermal laminating the photosensitive layer of the photosensitive element onto the substrate using a laminator.

[0102] Next, by irradiating at least a portion of the photosensitive layer with active light, the irradiated portion becomes photocured, and a latent image is formed. In this case, if a support is present on the photosensitive layer, if the support is transparent to the active light, the active light can be irradiated through the support. However, if the support is light-blocking, the support is removed before irradiating the photosensitive layer with active light.

[0103] Exposure methods include, for example, direct imaging exposure methods such as LDI (Laser Direct Imaging) exposure and DLP (Digital Light Processing) exposure, which involve irradiating an active ray in an image-like manner; methods of irradiating an active ray in an image-like manner via a negative mask pattern (mask exposure method); and methods of irradiating an active ray in an image-like manner via projection exposure. Examples of active rays include electron beams, ultraviolet rays, and X-rays. Examples of light sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and halogen lamps. The exposure dose is 10 to 2000 mJ / cm². ２ Or 100-1500 mJ / cm ２ That's fine.

[0104] After exposure, the unexposed areas are dissolved and removed with a developer to form a resist pattern. Development methods include, for example, dipping and spraying. Suitable developers include alkaline aqueous solutions such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, and tetramethylammonium hydroxide.

[0105] Next, the formed resist pattern can be sufficiently cured by at least one of post-exposure and post-heating to form a permanent resist. The exposure dose for post-exposure is 100 to 5000 mJ / cm². ２ , 500-2000mJ / cm ２ , or 700-1500 mJ / cm ２ The heating temperature for post-heating may be 100-200°C, 120-180°C, or 135-165°C. The heating time for post-heating may be 5 minutes to 6 hours, 10 minutes to 3 hours, or 30 minutes to 2 hours. The thickness of the permanent resist may be 10-50 μm, 15-40 μm, or 20-30 μm.

[0106] The permanent resist according to this embodiment can be used as an interlayer insulating layer or surface protective layer of a semiconductor element. A semiconductor element having an interlayer insulating layer or surface protective layer formed from the cured film of the above-described photosensitive resin composition, and an electronic device including the semiconductor element, can be manufactured. The semiconductor element may be, for example, a memory, package, etc., having a multilayer wiring structure, a rewiring structure, etc. Examples of electronic devices include mobile phones, smartphones, tablet terminals, personal computers, and hard disk suspensions.

[0107] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0108] <Examples 1-9 and Comparative Examples 1-2> [Photosensitive Resin Compositions] Each component was blended in the amounts (parts by mass, equivalent to solid content) shown in Table 2 below and kneaded in a three-roll mill. Then, methyl ethyl ketone was added to obtain a photosensitive resin composition so that the solid content concentration was 65% by mass. Details of each component shown in Table 2 are as follows. Also, the first group, second group and terminal group of each (E) silicone compound are shown in Table 1.

[0109] ((A) Acid-modified vinyl group-containing resin) A-1: ​​Acid-modified cresol novolac type epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd., trade name "CCR-1374H", acid value: 60 mg KOH / g, Mw: 6000-7000) ((B) Photopolymerizable compound) B-1: KAYARAD DPHA (mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate, manufactured by Nippon Kayaku Co., Ltd., trade name) ((C) Photopolymerization initiator) C-1: 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (manufactured by IGM Resins B.V., trade name "Omnirad 907") ((D) Inorganic filler) D-1: Silica-titania composite particles (volume average particle diameter: 300 nm, refractive index: 1.542, shape: spherical) ((E) Silicone compounds) E-1: Silicone oligomer (vinyl / phenyl oligomer, manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-511) E-2: Silicone oligomer (methyl oligomer, manufactured by Shin-Etsu Chemical Co., Ltd., product name: KC-89S) E-3: Silicone oligomer (methyl / phenyl oligomer, manufactured by Shin-Etsu Chemical Co., Ltd., product name: X-40-9227) E-4: Silicone resin (methyl / phenyl resin, manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-112) E-5: Silicone resin (methyl / phenyl resin, manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-211) E-6: Silicone resin (methyl / phenyl resin, manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-212) E-7: Silicone resin (methyl / phenyl resin, manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-271) E-8: Silicone oil (double-ended type / epoxy modified, manufactured by Shin-Etsu Chemical Co., Ltd., product name: X-22-163) ((F) Thermosetting resin) F-1: Bisphenol F type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., product name: YSLV-80XY, first polyfunctional epoxy resin, molecular weight 300 or more and less than 380) F-2: Phenol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name: RE-306, second polyfunctional epoxy resin, molecular weight 380 to 1200) ((G) Photosensitizer) G-1: 4,4'-bis(diethylamino)benzophenone G-2: 2,4-Diethylthioxanthone ((H) Polymerization inhibitor) H-1: 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl ((I) Coupling agent) I-1: 3-Methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-503) ((J) Pigment) J-1: Mixture of blue pigment and yellow pigment,

[0110] The refractive index of the inorganic filler was measured by immersion using the following procedure. First, solvents with different refractive indices (1-bromonaphthalene and liquid paraffin) were mixed in arbitrary proportions to prepare multiple mixed solvents with different refractive indices. Next, the inorganic filler was added to each mixed solvent to prepare a dispersion. The transparency of the dispersions was visually compared, and the refractive index of the mixed solvent used for the most transparent dispersion was taken as the refractive index of the inorganic filler.

[0111]

[0112] [Photosensitive Element] A polyethylene terephthalate film with a thickness of 25 μm (manufactured by Toyobo Co., Ltd., product name: HPES0) was prepared as a support film. The photosensitive resin composition was applied to the support film so that its thickness after drying was 18 μm, and dried at 100°C for 10 minutes using a hot air convection dryer to form a photosensitive layer. Next, a polyethylene film (manufactured by Tamapoly Co., Ltd., product name: NF-13) was laminated as a protective film onto the surface opposite to the side of the photosensitive layer that is in contact with the support film to obtain a photosensitive element.

[0113] [Evaluation] (Refractive index of cured product) While peeling off the protective film from the photosensitive elements obtained in the examples and comparative examples, the exposed photosensitive layer was laminated onto a silicon wafer using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") at a press hot plate temperature of 80°C, a vacuum evacuation time of 25 seconds, a lamination press time of 25 seconds, an atmospheric pressure of 4 kPa or less, and a pressing pressure of 0.4 MPa. Next, from the support film side of the photosensitive layer, a parallel light exposure machine (manufactured by Oak Seisakusho Co., Ltd., product name "EXM-1201") using an ultra-high pressure mercury lamp as the light source was used to expose it at 200 mJ / cm². ２The entire surface was exposed, and the support film was peeled off after exposure. A matching solution was applied to the surface of the cured photosensitive layer on the silicon wafer, and the refractive index of the cured photosensitive layer on the silicon wafer was measured under the following conditions while in close contact with a prism. The results are shown in Table 2. • Measurement device: Model 2010 / M PRISM COUPLER, manufactured by Metricon Corporation • Wavelength: 632.8 nm • Measurement temperature: 25°C • Measurement atmosphere: Air • Matching solution: IMMERSION LIQUID (nD=1.640), manufactured by Cargile Laboratories Inc.

[0114] (Crack Resistance) A roughened printed circuit board substrate (manufactured by Resonaq Corporation, product name "MCL-E-679"), in which 12 μm thick copper foil was laminated on a glass epoxy substrate, was treated with a roughening solution (manufactured by MEC Corporation, product name "CZ-8100") on the copper foil surface, washed with water, and then dried to obtain a roughened printed circuit board substrate. Next, the protective film was peeled off from the photosensitive elements obtained in each example and comparative example, and the exposed photosensitive layer was placed in contact with the copper foil of the roughened printed circuit board substrate. Then, lamination was performed using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500"). The lamination conditions were: press hot plate temperature 70°C, vacuum evacuation time 20 seconds, lamination press time 30 seconds, atmospheric pressure 4 kPa or less, and compression pressure 0.4 MPa. After lamination, the laminate A was obtained by leaving it at room temperature for more than one hour, in which a photosensitive layer and a support film were laminated in that order on the copper foil surface of the printed circuit board substrate.

[0115] A 41-step tablet was placed on the support film of laminate A, and exposure was performed using an i-line exposure apparatus (Ushio Inc., product name "UX-2240SM"). After exposure, the laminate was left at room temperature for 30 minutes, then the support film was peeled off, and the photosensitive layer was spray-developed for 40 seconds using a 1% by mass sodium carbonate aqueous solution at 30°C to remove unexposed areas. After development, the exposure energy required to obtain a glossy step count of 10.0 for the 41-step tablet was determined.

[0116] The laminate A was exposed using an i-line exposure system (manufactured by Ushio Inc., product name "UX-2240SM") on the support film. The exposure pattern was set using a negative mask with a predetermined size square via pattern (aperture size: 40-200 μm per side), and the exposure energy was set to the amount that resulted in 10.0 remaining glossy step steps for the 41-step step tablet determined above. After exposure, the material was left at room temperature for 30 minutes, then the support film was peeled off, and the photosensitive layer was spray-developed for 40 seconds using a 1% by mass sodium carbonate aqueous solution at 30°C to remove unexposed areas. After development, a total of 2000 mJ / cm² was applied using an ultraviolet exposure system. ２ Post-exposure was performed. After post-exposure, the material was heat-cured by heating at 170°C for 1 hour in an explosion-proof oven, and then further heated at 175°C for 5 hours. As a result, an evaluation laminate was obtained in which a cured film (permanent resist) with square via openings was formed on the copper foil surface of a printed circuit board substrate.

[0117] The obtained evaluation laminate was exposed to air at -65°C for 5 minutes, then heated to 150°C, and subsequently exposed to air at 150°C for 5 minutes, followed by a cooling cycle of -65°C. This thermal cycle was repeated 1000 times. After this thermal cycle test (thermal shock test), the permanent resist of the evaluation laminate was observed at 400 via openings with an aperture size of 60 μm using a 500x magnification digital microscope (Keyence, product name "VHX-6000"). The presence or absence of cracks was observed at the 400 observed locations, and the number of locations where cracks occurred was determined. Based on this number of crack locations, crack resistance was evaluated according to the following criteria. If the evaluation result was A or B, it was judged to have excellent crack resistance. The results are shown in Table 2. A: Number of crack locations is less than 4. B: Number of crack locations is 4 or more and 10 or less. C: Number of crack locations is greater than 10.

[0118] (Resolution) The laminate A was exposed using an i-line exposure apparatus (manufactured by Ushio Inc., product name "UX-2240SM") on the support film. The exposure pattern used a negative mask with an aperture pattern of a predetermined size (aperture diameter size in 1 μm increments from 5 to 40 μm, and in 10 μm increments from 40 to 60 μm). The exposure was performed with an exposure energy amount that resulted in a glossy remaining step count of 10.0 for the 41-step step tablet determined in the crack resistance evaluation above. After exposure, the material was left at room temperature for 30 minutes, then the support film was peeled off and the photosensitive layer was spray-developed for 40 seconds using a 1% by mass sodium carbonate aqueous solution at 30°C to remove unexposed areas. After development, a total of 2000 mJ / cm² was applied using an ultraviolet exposure apparatus. ２ Post-exposure was performed. The via pattern of the obtained cured film (permanent resist) was observed using an optical microscope, and the resolution was evaluated based on the minimum diameter of the mask through which the vias opened. Here, the state in which the vias are "open" refers to the state in which the copper foil of the printed circuit board substrate can be seen when the via opening is observed from directly above using an optical microscope. The smaller this value, the better the resolution. Based on the obtained values, the resolution was evaluated according to the following criteria. If the evaluation result is A or B, it is judged to be excellent resolution. The results are shown in Table 2. A: Minimum diameter of the mask through which the vias open is less than 18 μm. B: Minimum diameter of the mask through which the vias open is 18 μm or more and less than 25 μm. C: Minimum diameter of the mask through which the vias open is 25 μm or more.

[0119]

[0120] 1...Photosensitive element, 10...Support film, 20...Photosensitive layer, 30...Protective film.

Claims

1. A photosensitive resin composition for permanent resists, comprising (A) an acid-modified vinyl group-containing resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silicone compound, wherein the (E) silicone compound is a compound having at least one first group selected from the group consisting of ethylenically unsaturated groups, alkyl groups, and aryl groups, and at least one second group selected from the group consisting of alkoxy groups and silanol groups.

2. The photosensitive resin composition according to claim 1, wherein the content of the (E) silicone compound is 0.1 to 15% by mass based on the total amount of solids in the photosensitive resin composition.

3. The photosensitive resin composition according to claim 1, wherein the (D) inorganic filler comprises an inorganic filler having a refractive index of 1.520 to 1.

680.

4. The photosensitive resin composition according to claim 1, wherein the (D) inorganic filler comprises composite particles of silica and a metal oxide other than silica.

5. The photosensitive resin composition according to claim 4, wherein the composite particles include silica-titania composite particles.

6. The photosensitive resin composition according to claim 1, wherein the content of the inorganic filler (D) is 40 to 85% by mass based on the total amount of solids in the photosensitive resin composition.

7. (F) The photosensitive resin composition according to claim 1, further comprising a thermosetting resin.

8. A photosensitive element comprising a support film and a photosensitive layer formed on the support film, wherein the photosensitive layer contains the photosensitive resin composition described in any one of claims 1 to 7.

9. A printed circuit board comprising a permanent resist containing a cured product of the photosensitive resin composition according to any one of claims 1 to 7.

10. A method for manufacturing a printed circuit board, comprising the steps of: forming a photosensitive layer on a substrate using a photosensitive resin composition according to any one of claims 1 to 7; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist.

11. A method for manufacturing a printed circuit board, comprising the steps of: forming a photosensitive layer on a substrate using the photosensitive element described in claim 8; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist.

Images