Photosensitive resin composition, photosensitive resin film, multilayer printed circuit board and semiconductor package, and method for manufacturing a multilayer printed circuit board.

Abstract

To provide a photosensitive resin composition that has excellent dielectric properties and expresses high adhesive strength to copper plating, a photosensitive resin film using the photosensitive resin composition, a multilayer printed wiring board and a method for producing the same, and a semiconductor package.SOLUTION: A photosensitive resin composition comprises (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, (B) thermosetting resin, and (C) a particle having acrylic resin thereon and having an elastomer therein.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a photosensitive resin composition, a photosensitive resin film, a multilayer printed wiring board and a semiconductor package, and a method for manufacturing a multilayer printed wiring board.

Background Art

[0002] In recent years, miniaturization and high performance of electronic devices have advanced, and multilayer printed wiring boards are progressing in increasing the number of circuit layers and in high density due to miniaturization of wiring. In particular, high density of semiconductor package substrates such as BGA (Ball Grid Array) and CSP (Chip Size Package) on which semiconductor chips are mounted is remarkable, and in addition to miniaturization of wiring, thinning of the insulating layer and further reduction in the diameter of vias (also referred to as via holes) for interlayer connection are required.

[0003] As a method for manufacturing a printed wiring board that has been conventionally adopted, there is a method for manufacturing a multilayer printed wiring board by a build-up method in which an interlayer insulating layer and a conductor circuit layer are sequentially laminated (see, for example, Patent Document 1). In multilayer printed wiring boards, with the miniaturization of circuits, a semi-additive process in which circuits are formed by plating has become mainstream. In the conventional semi-additive process, for example, (1) a thermosetting resin film is laminated on a conductor circuit, and the thermosetting resin film is cured by heating to form an "interlayer insulating layer". (2) Next, vias for interlayer connection are formed by laser processing, and desmear treatment and roughening treatment are performed by alkaline permanganate treatment or the like. (3) Thereafter, the substrate is subjected to electroless copper plating treatment, and after pattern formation using a resist, electroplating of copper is performed to form a copper circuit layer. (4) Next, the resist is peeled off, and flash etching of the electroless layer is performed, whereby a copper circuit has been formed.

[0004] As described above, laser processing is the mainstream method for forming vias in an interlayer insulating layer formed by curing a thermosetting resin film. However, the reduction of the via diameter by laser irradiation using a laser processing machine is approaching its limit. Furthermore, in the formation of vias by a laser processing machine, it is necessary to form each via hole one by one. When a large number of vias need to be provided due to high density, it takes a long time to form the vias, and there is a problem of poor manufacturing efficiency.

[0005] Under such circumstances, as a method capable of forming a large number of vias in a batch, a photosensitive resin composition containing an acid-modified vinyl group-containing epoxy resin, a photopolymerizable compound, a photoinitiator, an inorganic filler, and a silane compound, and having an inorganic filler content of 10 to 80% by mass has been proposed to form a plurality of small-diameter vias in a batch by a photolithography method (see, for example, Patent Document 2). In Patent Document 2, as one of the problems, suppression of the decrease in adhesion to copper plating due to using a photosensitive resin composition instead of a conventional thermosetting resin composition as a material for the interlayer insulating layer or the surface protection layer is regarded as one of the problems. Furthermore, the resolution of vias, the adhesion to a silicon substrate and chip components are also regarded as problems, and it is stated that these have been solved. By the way, in recent years, substrate materials are required to be applied to fifth-generation mobile communication systems (5G) antennas using radio waves in the high-frequency band and millimeter-wave radars using radio waves in the frequency band of 30 to 300 GHz. For this purpose, it is necessary to develop a resin composition with further improved dielectric tangent in the 10 GHz band or higher. However, in the technology of Patent Document 2, there is room for improvement in the dielectric tangent.

[0006] On the other hand, as a photosensitive resin composition excellent in dielectric tangent at high frequencies, Patent Document 3 proposes a photosensitive resin composition containing a carboxyl group-containing resin, an unsaturated compound having at least one ethylenically unsaturated bond in one molecule, a photoinitiator, an epoxy compound, an organic filler, silica, and a triazine resin, wherein the average primary particle diameter of the silica is 1 nm or more and 150 nm or less.

Prior Art Documents

[0007] [Patent Document 1] Japanese Patent Application Publication No. 7-304931 [Patent Document 2] Japanese Patent Publication No. 2017-116652 [Patent Document 3] International Publication No. 2019 / 230616 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Through diligent research conducted by the present inventors, it was found that when using the organic filler specifically described in Patent Document 3, compatibility with other components may be insufficient, leading to aggregation of the organic filler in the photosensitive resin composition. As a result, the effect of improving the dielectric constant may decrease, and furthermore, the adhesive strength with copper plating may also decrease.

[0009] Therefore, the object of this disclosure is to provide a photosensitive resin composition that has excellent dielectric properties and exhibits high adhesive strength with copper plating, a photosensitive resin film using the photosensitive resin composition, a multilayer printed circuit board and a method for manufacturing the same, and a semiconductor package. [Means for solving the problem]

[0010] As a result of diligent research, the present inventors have found that the above objective can be achieved by this disclosure. This disclosure includes the following embodiments [1] to

[17] . [1] (A) Photopolymerizable compounds having an ethylenically unsaturated group and an acidic substituent, (B) Thermosetting resins, and (C) Particles having an acrylic resin on the surface and an elastomer inside, A photosensitive resin composition containing [a specific substance]. [2] The photosensitive resin composition according to [1] above, wherein the acrylic resin is at least one selected from the group consisting of a homopolymer of acrylic acid esters, a copolymer of acrylic acid esters, a homopolymer of methacrylic acid esters, a copolymer of methacrylic acid esters, and a copolymer of acrylic acid esters and methacrylic acid esters. [3] The photosensitive resin composition according to [1] or [2], wherein the elastomer is at least one elastomer selected from the group consisting of a homopolymer of a compound having a conjugated double bond, a copolymer of compounds having conjugated double bonds, and a copolymer of a compound having a conjugated double bond and an aromatic hydrocarbon having an ethylenically unsaturated double bond. [4] The photosensitive resin composition according to any one of [1] to [3] above, wherein the volume average particle size of component (C) is 20 to 1,000 nm. [5] The photosensitive resin composition according to any one of [1] to [4] above, wherein the content of component (C) is 5 to 45% by volume on a basis of the total solid content of the photosensitive resin composition. [6] The photosensitive resin composition according to any one of [1] to [5] above, wherein the component (A) includes an alicyclic structure represented by the following general formula (A-1). [ka] (In the formula, R A1 m represents an alkyl group having 1 to 12 carbon atoms and may be substituted anywhere in the alicyclic structure. 1 (This is an integer between 0 and 6. * indicates a binding site to another structure.) [7] Furthermore, the photosensitive resin composition according to any one of [1] to [6] above, comprising (D) a crosslinking agent. [8] Furthermore, (E) a photosensitive resin composition according to any one of [1] to [7] above, comprising an inorganic filler. [9] Furthermore, a photosensitive resin composition according to any of [1] to [8] above, comprising (F) a curing agent.

[10] The photosensitive resin composition according to any one of [1] to [9] above, further comprising (G) a thermal polymerization initiator.

[11] A photosensitive resin composition according to any one of [1] to

[10] above, further comprising (H) a photopolymerization initiator.

[12] The photosensitive resin composition according to

[11] above, comprising two or more of the (H) photopolymerization initiators.

[13] A photosensitive resin composition according to any one of [1] to

[12] above, used for forming one or more selected from the group consisting of photovias and interlayer insulating layers.

[14] A photosensitive resin film comprising the photosensitive resin composition described in any of [1] to

[13] above.

[15] A multilayer printed circuit board comprising an interlayer insulating layer formed using a photosensitive resin composition according to any of [1] to

[13] above, or a photosensitive resin film according to

[14] above.

[16] A semiconductor package comprising the multilayer printed circuit board described in

[15] above and a semiconductor element.

[17] A method for manufacturing a multilayer printed circuit board, comprising the following (1) to (4). (1) Laminating the photosensitive resin film described in

[14] above onto one or both sides of the circuit board. (2) Forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in (1) above. (3) Roughen the vias and the interlayer insulating layer. (4) Forming a circuit pattern on the interlayer insulating layer. [Effects of the Invention]

[0011] This disclosure provides a photosensitive resin composition that has excellent dielectric properties and exhibits high adhesive strength to copper plating. It also provides a photosensitive resin film formed using the photosensitive resin composition. Furthermore, it provides a multilayer printed circuit board containing an interlayer insulating layer formed using the photosensitive resin composition or the photosensitive resin film, and also provides a method for manufacturing the multilayer printed circuit board. Moreover, it provides a semiconductor package including the multilayer printed circuit board and semiconductor elements. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram illustrating one aspect of the manufacturing process for a multilayer printed circuit board in which the photosensitive resin film of this embodiment is used as the material for at least one of the surface protective layer and the interlayer insulating layer. [Modes for carrying out the invention]

[0013] In the numerical ranges described herein, the upper or lower limits of those ranges may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower or upper limits of other numerical ranges. In the notation "AA~BB" for a numerical range, the numbers AA and BB at both ends are included in the range as the lower and upper limits, respectively. In this specification, for example, the phrase "10 or more" means 10 and numbers greater than 10, and the same applies to numbers that are different. Similarly, for example, the phrase "10 or less" means 10 and numbers less than 10, and the same applies to numbers that are different. In this specification, the content of each component in a photosensitive resin composition means the total content of multiple substances present in the photosensitive resin composition, unless otherwise specified, if there are multiple substances corresponding to each component. In this specification, "ring-forming carbon number" refers to the number of carbon atoms required to form a ring, and does not include the number of carbon atoms in substituents on the ring. For example, both the cyclohexane skeleton and the methylcyclohexane skeleton have a ring-forming carbon number of 6. The notation "(meth)acrylic XX" refers to either or both acrylic XX and its corresponding methacrylic XX. Similarly, "(meth)acryloyl group" refers to either or both an acryloyl group and a methacryloyl group. In this specification, dielectric properties refer to relative permittivity and dielectric loss tangent, and unless otherwise specified, relative permittivity and dielectric loss tangent refer to relative permittivity and dielectric loss tangent in the 10 GHz band. In other words, when we refer to dielectric properties, we mean dielectric properties in the 10 GHz band. Furthermore, embodiments that arbitrarily combine the matters described herein are also included in this embodiment.

[0014] [Photosensitive resin composition] A photosensitive resin composition according to one embodiment of this disclosure (hereinafter sometimes simply referred to as this embodiment) is (A) Photopolymerizable compounds having an ethylenically unsaturated group and an acidic substituent, (B) Thermosetting resins, and (C) Particles having an acrylic resin on the surface and an elastomer inside, This is a photosensitive resin composition containing [a specific substance]. In this specification, the above components may be abbreviated as component (A), component (B), component (C), etc., and other components may be abbreviated in the same manner. In this specification, "resin component" refers to component (A) and component (B), etc., and also includes other components that may be included as needed (e.g., (C), (D), (F), (G), (H), and (I), etc.), but does not include inorganic compounds such as (E) inorganic fillers and pigments. Furthermore, "solid content" refers to the non-volatile content of the photosensitive resin composition excluding volatile substances such as water and solvents, and indicates the components that remain without volatilization when the resin composition is dried, and also includes liquid, syrup-like, and wax-like substances at room temperature around 25°C.

[0015] The photosensitive resin composition of this embodiment has excellent dielectric properties and is suitable for via formation by photolithography (also referred to as photovia formation), and is therefore suitable for forming one or more types selected from the group consisting of photovias and interlayer insulating layers. For this reason, this disclosure also provides a photosensitive resin composition for photovia formation and a photosensitive resin composition for interlayer insulating layers made from the photosensitive resin composition of this embodiment. Herein, in this disclosure, when the term "layer" is used, for example, as in interlayer insulating layer, it includes not only solid layers but also layers that are not solid but have at least a portion in the form of islands, layers with holes, and layers where the interface with the adjacent layer is unclear. Furthermore, the photosensitive resin composition of this embodiment is suitable for negative-type photosensitive resin compositions. The following details each component that may be contained in the photosensitive resin composition.

[0016] <(A) Photopolymerizable compounds having ethylenically unsaturated groups and acidic substituents> The photosensitive resin composition of this embodiment contains a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent as component (A). (A) Component (A) may be used alone or in combination of two or more components.

[0017] Component (A) is a compound that exhibits photopolymerization, particularly radical polymerization, because it has an ethylenically unsaturated group. (A) Examples of ethylenically unsaturated groups in component (A) include photopolymerizable functional groups such as vinyl group, allyl group, propargyl group, butenyl group, ethynyl group, phenylethynyl group, maleimide group, nadiimide group, and (meth)acryloyl group. Among these, (meth)acryloyl group is preferred from the viewpoint of reactivity and via resolution.

[0018] Component (A) has an acidic substituent, from the viewpoint of enabling alkaline development. (A) Examples of acidic substituents on component (A) include carboxyl groups, sulfonic acid groups, and phenolic hydroxyl groups. Among these, carboxyl groups are preferred from the viewpoint of via resolution. The acid value of component (A) is preferably 20 to 200 mg KOH / g, more preferably 40 to 180 mg KOH / g, even more preferably 70 to 150 mg KOH / g, and particularly preferably 90 to 120 mg KOH / g. When the acid value of component (A) is above the lower limit, the solubility of the photosensitive resin film in dilute alkaline solutions tends to be excellent, and when it is below the upper limit, the dielectric properties of the cured product tend to be excellent. The acid value of component (A) can be calculated from the amount of potassium hydroxide aqueous solution required to neutralize component (A). Furthermore, 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 two or more components (A) be within any of the above ranges.

[0019] The weight-average molecular weight (Mw) of component (A) is preferably 600 to 30,000, more preferably 800 to 25,000, even more preferably 1,000 to 18,000, even more preferably 1,000 to 8,000, particularly preferably 1,200 to 5,000, and most preferably 1,200 to 3,500. When the weight-average molecular weight (Mw) of component (A) is within the above range, the adhesion strength to copper plating, heat resistance, and insulation reliability tend to be excellent. Hereinafter, the weight-average molecular weight is the value obtained on a standard polystyrene basis by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and more specifically, the value measured according to the method described in the examples.

[0020] Component (A) preferably contains an alicyclic skeleton from the viewpoint of dielectric properties. (A) As for the alicyclic skeleton of component (A), from the viewpoint of via resolution, adhesion strength with copper plating and electrical insulation reliability, an alicyclic skeleton with 5 to 20 ring-forming carbon atoms is preferred, an alicyclic skeleton with 5 to 18 ring-forming carbon atoms is more preferred, an alicyclic skeleton with 6 to 18 ring-forming carbon atoms is even more preferred, an alicyclic skeleton with 8 to 14 ring-forming carbon atoms is particularly preferred, and an alicyclic skeleton with 8 to 12 ring-forming carbon atoms is most preferred. Furthermore, the above-mentioned alicyclic skeleton is preferably composed of two or more rings, more preferably of two to four rings, and even more preferably of three rings, from the viewpoint of via resolution, adhesion strength with copper plating, and electrical insulation reliability. Examples of alicyclic skeletons with two or more rings include norbornane skeletons, decalin skeletons, bicycloundecane skeletons, and saturated dicyclopentadiene skeletons. Among these, the saturated dicyclopentadiene skeleton is preferred from the viewpoint of via resolution, adhesion strength with copper plating, and electrical insulation reliability. From a similar viewpoint, component (A) is preferably one that includes an alicyclic structure represented by the following general formula (A-1).

[0021] [ka] (In the formula, R A1 represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere in the above alicyclic structure. 1 (This is an integer between 0 and 6. * indicates a binding site to another structure.)

[0022] In the above general formula (A-1), R A1 Examples of C1-C12 alkyl groups represented by include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. C1-C6 alkyl groups are preferred, C1-C3 alkyl groups are more preferred, and methyl groups are even more preferred. m 1 is an integer between 0 and 6, preferably between 0 and 2, and more preferably 0. m 1 If is an integer between 2 and 6, multiple R A1They may be the same or different from each other. Further, the plurality of Rs A1 may be substituted on the same carbon atom within the possible range, or may be substituted on different carbon atoms. * is a bonding site to another structure and may be bonded to any carbon atom on the alicyclic skeleton, but is preferably bonded to the carbon atom represented by 1 or 2 and the carbon atom represented by either 3 or 4 in the following general formula (A-1’).

[0023] [Chemical formula] (In the formula, R A1 , m 1 and * are the same as those in the general formula (A-1).)

[0024] Component (A) is preferably an acid-modified vinyl group-containing epoxy resin obtained by reacting (a1) an epoxy resin modified with (a2) an ethylenically unsaturated group-containing organic acid [hereinafter sometimes referred to as component (A’)] with (a3) a saturated group or unsaturated group-containing polybasic acid anhydride, from the viewpoints of the resolution of vias and the adhesion strength to copper plating. Here, “acid modification” of the acid-modified vinyl group-containing epoxy resin means having an acidic substituent, “vinyl group” means an ethylenically unsaturated group, “epoxy resin” means using an epoxy resin as a raw material, and the acid-modified vinyl group-containing epoxy resin does not necessarily have to have an epoxy group and may not have an epoxy group. Hereinafter, preferred embodiments of component (A) obtained from (a1) an epoxy resin, (a2) an ethylenically unsaturated group-containing organic acid, and (a3) a saturated group or unsaturated group-containing polybasic acid anhydride will be described.

[0025] ((a1) Epoxy resin) As (a1) the epoxy resin, it is preferably an epoxy resin having two or more epoxy groups. (a1) The epoxy resin may be used alone or in combination of two or more. (a1) Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0026] (a1) Epoxy resins can be classified into various types based on differences in their main skeleton, including epoxy resins with an alicyclic skeleton, novolac-type epoxy resins, bisphenol-type epoxy resins, aralkyl-type epoxy resins, and other epoxy resins. Among these, epoxy resins with an alicyclic skeleton and novolac-type epoxy resins are preferred.

[0027] -Epoxy resin with an alicyclic skeleton- The alicyclic skeleton of the epoxy resin having an alicyclic skeleton will be described in the same way as the alicyclic skeleton of component (A) described above, and the preferred embodiments will also be the same. As an epoxy resin having an alicyclic skeleton, epoxy resin represented by the following general formula (A-2) is preferred.

[0028] [ka] (In the formula, R A1 R represents an alkyl group having 1 to 12 carbon atoms and may be substituted anywhere in the above alicyclic skeleton. A2 m represents an alkyl group with 1 to 12 carbon atoms. 1 is an integer from 0 to 6, m 2 n is an integer between 0 and 3. n is a number between 0 and 50.

[0029] In general formula (A-2), R A1 R in general formula (A-1) A1 It is the same as, and the preferred form is also the same. R in general formula (A-2) A2Examples of C1-C12 alkyl groups represented by include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. C1-C6 alkyl groups are preferred, C1-C3 alkyl groups are more preferred, and methyl groups are even more preferred. m in general formula (A-2) 1 m in general formula (A-1) 1 It is the same as, and the preferred form is also the same. m in general formula (A-2) 2 is an integer between 0 and 3, preferably 0 or 1, and more preferably 0. In general formula (A-2), n represents the number of repetitions of the structural unit in parentheses, and is a number between 0 and 50. Typically, epoxy resins are mixtures of structural units with different numbers of repetitions, so in that case, n is represented by the average value of the mixture. A number between 0 and 30 is preferred for n.

[0030] As the epoxy resin having an alicyclic skeleton, commercially available products may be used, such as XD-1000 (manufactured by Nippon Kayaku Co., Ltd., trade name) and EPICLON® HP-7200 (manufactured by DIC Corporation, trade name).

[0031] -Novolac-type epoxy resin- Examples of novolac-type epoxy resins include bisphenol novolac-type epoxy resins such as bisphenol A novolac-type epoxy resin, bisphenol F novolac-type epoxy resin, and bisphenol S novolac-type epoxy resin; phenol novolac-type epoxy resin, cresol novolac-type epoxy resin, biphenyl novolac-type epoxy resin, and naphthol novolac-type epoxy resin. As the novolac-type epoxy resin, epoxy resin having a structural unit represented by the following general formula (A-3) is preferred.

[0032] [ka] (In the formula, RA3 Y represents a hydrogen atom or a methyl group. A1 Each of these independently represents a hydrogen atom or a glycidyl group. The two R A3 These can be the same or different. A1 At least one of them represents a glycidyl group.

[0033] R A3 From the viewpoint of via resolution and adhesion strength with copper plating, it is preferable that both are hydrogen atoms. Also, from a similar viewpoint, Y A1 Preferably, all of these are glycidyl groups. The number of structural units in the epoxy resin (a1) having structural units represented by general formula (A-3) is 1 or more, preferably 10 to 100, more preferably 15 to 80, and even more preferably 15 to 70. When the number of structural units is within the above range, the adhesion strength to copper plating, heat resistance, and insulation reliability tend to improve. In general formula (A-3), R A3 Both are hydrogen atoms, Y A1 Those that all have a glycidyl group are sold as the EXA-7376 series (manufactured by DIC Corporation, product name), and also R A3 Both are methyl groups, Y A1 All of these, which have a glycidyl group, are commercially available as the EPON SU8 series (manufactured by Mitsubishi Chemical Corporation, product name).

[0034] Examples of bisphenol-type epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and 3,3',5,5'-tetramethyl-4,4'-diglycidyloxydiphenylmethane. Examples of aralkyl epoxy resins include phenol aralkyl epoxy resins, biphenyl aralkyl epoxy resins, and naphthol aralkyl epoxy resins. Other epoxy resins include stilbene-type epoxy resins, naphthalene-backed epoxy resins, biphenyl-type epoxy resins, dihydroanthracene-type epoxy resins, cyclohexanedimethanol-type epoxy resins, trimethylol-type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, heterocyclic epoxy resins, spiro-ring-containing epoxy resins, and rubber-modified epoxy resins.

[0035] ((a2) Ethylenically unsaturated group-containing organic acid) (a2) As for organic acids containing ethylenically unsaturated groups, monocarboxylic acids containing ethylenically unsaturated groups are preferred. The ethylenically unsaturated groups of component (a2) are the same as those listed as the ethylenically unsaturated groups of component (A). (a2) Examples of components include acrylic acid derivatives such as acrylic acid, acrylic acid dimers, methacrylic acid, β-furfuryl acrylic acid, β-styryl acrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid; semi-ester compounds which are reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides; and semi-ester compounds which are reaction products of vinyl group-containing monoglycidyl ethers or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides. (a2) The component may be used alone or in combination of two or more components.

[0036] The above-mentioned semi-ester compounds are obtained by reacting one or more ethylenically unsaturated group-containing compounds selected from the group consisting of hydroxyl group-containing acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters with a dibasic acid anhydride. In this reaction, it is preferable to react the ethylenically unsaturated group-containing compound and the dibasic acid anhydride in equimolar amounts.

[0037] Examples of hydroxyl group-containing acrylates used in the synthesis of the above-mentioned semi-ester compounds include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, trimethylolpropanedi(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Examples of vinyl group-containing monoglycidyl ethers include glycidyl (meth)acrylate.

[0038] The dibasic acid anhydride used in the synthesis of the above-mentioned semi-ester compound may contain saturated groups or unsaturated groups. 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.

[0039] In the reaction between component (a1) and component (a2), the amount of component (a2) used per equivalent of epoxy group of component (a1) is preferably 0.6 to 1.05 equivalents, more preferably 0.7 to 1.02 equivalents, and even more preferably 0.8 to 1.0 equivalents. By reacting component (a1) and component (a2) in the above ratio, the photopolymerizability of component (A) is improved, and the resolution of vias in the resulting photosensitive resin composition tends to improve.

[0040] It is preferable to dissolve components (a1) and (a2) in an organic solvent and react them. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ether compounds 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; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. Organic solvents may be used individually or in combination of two or more.

[0041] It is preferable to use a catalyst to accelerate the reaction between component (a1) and component (a2). Examples of such catalysts include amine catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and benzyltrimethylammonium iodide; and phosphine catalysts such as triphenylphosphine. Among these, phosphine catalysts are preferred, and triphenylphosphine is more preferred. The catalyst may be used alone or in combination of two or more. When a catalyst is used, the amount used is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass, per 100 parts by mass of the total of components (a1) and (a2), from the viewpoint of obtaining an appropriate reaction rate.

[0042] In the reaction between component (a1) and component (a2), it is preferable to use a polymerization inhibitor to prevent polymerization during the reaction. Examples of polymerization inhibitors include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol. A single polymerization inhibitor may be used, or two or more may be used in combination. When a polymerization inhibitor is used, the amount used is preferably 0.01 to 1 part by mass, more preferably 0.02 to 0.8 parts by mass, and even more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of the total of components (a1) and (a2).

[0043] The reaction temperature between component (a1) and component (a2) is preferably 60 to 150°C, more preferably 80 to 120°C, and even more preferably 90 to 110°C, from the viewpoint of obtaining sufficient reactivity while allowing the reaction to proceed homogeneously.

[0044] Thus, when an ethylenically unsaturated monocarboxylic acid is used as component (a2), component (A') obtained by reacting component (a1) and component (a2) will have a hydroxyl group formed by a ring-opening addition reaction between the epoxy group of component (a1) and the carboxyl group of component (a2). Next, by further reacting component (a3) ​​with component (A'), an acid-modified vinyl group-containing epoxy resin can be obtained in which the hydroxyl groups of component (A') (including the hydroxyl groups originally present in component (a1)) and the acid anhydride group of component (a3) ​​are semi-esterified.

[0045] ((a3) Polybasic anhydrides) (a3) Component may contain saturated groups or unsaturated groups. Examples of (a3) ​​component include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride. Among these, tetrahydrophthalic anhydride is preferred from the viewpoint of via resolution. Component (a3) ​​may be used alone or in combination of two or more.

[0046] In the reaction between component (A') and component (a3), for example, the acid value of the acid-modified vinyl group-containing epoxy resin can be adjusted by reacting 0.1 to 1.0 equivalents of component (a3) ​​with 1 equivalent of hydroxyl group in component (A').

[0047] The reaction temperature between component (A') and component (a3) ​​is preferably 50 to 150°C, more preferably 60 to 120°C, and even more preferably 70 to 100°C, from the viewpoint of obtaining sufficient reactivity while allowing the reaction to proceed homogeneously.

[0048] The content of component (A) in the photosensitive resin composition of this embodiment is not particularly limited, but from the viewpoint of heat resistance, dielectric properties and chemical resistance, it is preferably 10 to 80% by mass, more preferably 10 to 60% by mass, even more preferably 15 to 55% by mass, and particularly preferably 15 to 50% by mass, based on the total amount of resin components of the photosensitive resin composition, and may also be 20 to 45% by mass or 25 to 40% by mass.

[0049] <(B) Thermosetting resin> The photosensitive resin composition of this embodiment may further contain a thermosetting resin as component (B), and it is preferable that it does. Component (B) does not contain component (A). The photosensitive resin composition of this embodiment, by containing (B) a thermosetting resin, tends to improve heat resistance in addition to improving adhesion strength and insulation reliability with copper plating. Examples of thermosetting resins include epoxy resins, phenolic resins, unsaturated imide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins. Furthermore, the use of known thermosetting resins is not limited to these. Among these, unsaturated imide resins are preferred from the viewpoint of dielectric properties. (B) Component may be used alone or in combination of two or more components.

[0050] As the unsaturated imide resin, maleimide compounds are preferred from the viewpoint of dielectric properties and adhesion strength to copper plating. As the maleimide compound, maleimide compounds having two or more N-substituted maleimide groups are preferred. Maleimide compounds include aromatic bismaleimide compounds having two N-substituted maleimide groups in the molecule, such as bis(4-maleimidophenyl)methane, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, and 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane; aromatic polymaleimide compounds having three or more N-substituted maleimide groups in the molecule, such as polyphenylmethanemaleimide and biphenylaralkyl-type maleimide; and aliphatic maleimide compounds such as 1,6-bismaleimide-(2,2,4-trimethyl)hexane and pyrrolironate binder-type long-chain alkylbismaleimide. Among these, aromatic maleimide compounds having two or more N-substituted maleimide groups are preferred from the viewpoint of heat resistance and dielectric properties, aromatic polymaleimide compounds having three or more N-substituted maleimide groups in the molecule are more preferred, and biphenyl aralkyl type maleimides are even more preferred.

[0051] (B) A maleimide compound represented by the following general formula (B-1) is preferred as component (B).

[0052] [ka] (In the formula, X B1 (It is a divalent organic group.)

[0053] X B1 The divalent organic group represented by can be any group represented by the following general formulas (B-2), (B-3), (B-4), (B-5), or (B-6), and is not particularly limited, but is preferably the group represented by the following formula (B-5).

[0054] [ka] (In the formula, R B1is an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. p1 is an integer from 0 to 4. * indicates a bonding site to another structure.

[0055] R B1 Examples of aliphatic hydrocarbon groups having 1 to 5 carbon atoms that can be represented by include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. The aliphatic hydrocarbon group may also be an aliphatic hydrocarbon group having 1 to 3 carbon atoms, or it may be a methyl group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. p1 is an integer between 0 and 4, and for ease of availability, it may also be an integer between 0 and 2, or 0 or 1, or 0. If p1 is an integer greater than or equal to 2, multiple R B1 The individuals may be the same or different.

[0056] [ka] (In the formula, R B2 and R B3 Each of these is independently an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. B2 is an alkylene group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, a single bond, or a divalent group represented by the general formula (B-3-1) below. p2 and p3 are each independently integers from 0 to 4. * indicates a bonding site to another structure.

[0057] R B2 and R B3 The aliphatic hydrocarbon group with 1 to 5 carbon atoms represented by R is an aliphatic hydrocarbon group with 1 to 5 carbon atoms, and the halogen atom is R. B1 The same examples as in the previous case are given. The aliphatic hydrocarbon group may be an aliphatic hydrocarbon group having 1 to 3 carbon atoms, a methyl group, an ethyl group, or an ethyl group. X B2Examples of alkylene groups having 1 to 5 carbon atoms represented by include methylene groups, 1,2-dimethylene groups, 1,3-trimethylene groups, 1,4-tetramethylene groups, and 1,5-pentamethylene groups. From the viewpoint of compatibility with other resins, adhesive strength with conductors, heat resistance, low thermal expansion, and mechanical properties, the alkylene group may be an alkylene group having 1 to 3 carbon atoms, or it may be a methylene group. X B2 Examples of alkylidene groups with 2 to 5 carbon atoms represented by include ethylidene, propyridene, isopropylidene, butyridene, isobutylidene, pentyridene, and isopentylidene. Among these, isopropylidene may be preferred from the viewpoint of compatibility with other resins, adhesive strength with conductors, heat resistance, low thermal expansion, and mechanical properties. X B2 Among the above options, alkylene groups with 1 to 5 carbon atoms and alkylidene groups with 2 to 5 carbon atoms may also be used. p2 and p3 are each an integer between 0 and 4, and from the standpoint of availability, they may both be integers between 0 and 2, or 0 or 2. If p2 or p3 is an integer greater than or equal to 2, multiple R B2 Mutual or R B3 The individuals may be identical or different. Note X B2 The divalent group represented by the general formula (B-3-1) is as follows:

[0058] [ka] (In the formula, R B4 and R B5 Each of these is independently an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. B3 The group is an alkylene group with 1 to 5 carbon atoms, an alkylidene group with 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, or a single bond. p4 and p5 are each independently integers from 0 to 4. * indicates a bonding site to another structure.

[0059] RB4 and R B5 The aliphatic hydrocarbon group with 1 to 5 carbon atoms represented by R is an aliphatic hydrocarbon group with 1 to 5 carbon atoms, and the halogen atom is R. B1 It is explained in the same way as in the case of this example. X B3 The alkylene group with 1 to 5 carbon atoms and the alkylidene group with 2 to 5 carbon atoms represented by are: B2 Examples include alkylene groups with 1 to 5 carbon atoms and alkylidene groups with 2 to 5 carbon atoms, which are the same as those represented by [the symbol]. X B3 Alternatively, an alkylidene group with 2 to 5 carbon atoms may be selected from the above options. p4 and p5 are each an integer between 0 and 4, and from the standpoint of availability, they may both be integers between 0 and 2, 0 or 1, or 0. If p4 or p5 is an integer of 2 or greater, multiple R B4 Mutual or R B5 The individuals may be identical or different.

[0060] [ka] (In the formula, p6 is an integer between 0 and 10. * indicates a binding site to another structure.)

[0061] p6 may be an integer between 0 and 5, or an integer between 0 and 3, from the standpoint of availability. [ka] (In the formula, p7 can be a number from 0 to 5. * indicates a binding site to another structure.)

[0062] For ease of availability, p7 may be a number between 0 and 4, or a number between 0 and 3.

[0063] [ka] (In the formula, R B6 and R B7Each of these is independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. p8 is an integer from 1 to 8. * indicates a bonding site to another structure.

[0064] R B6 and R B7 As an example of an aliphatic hydrocarbon group with 1 to 5 carbon atoms represented by R, B1 It is explained in the same way as in the case of this example. p8 is an integer between 1 and 8, and may be an integer between 1 and 3, or it may be 1. If p8 is an integer greater than or equal to 2, then multiple R B6 Mutual or R B7 The individuals may be identical or different.

[0065] The content ratio [(A) / (B)] of (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent to (B) a thermosetting resin is not particularly limited, but from the viewpoint of heat resistance and dielectric properties, it is preferably 0.5 to 7, more preferably 1.0 to 5, and even more preferably 1.2 to 3 by mass.

[0066] The content of component (B) in the photosensitive resin composition of this embodiment is not particularly limited, but from the viewpoint of insulation reliability, dielectric properties, heat resistance and adhesion strength with copper plating, it is preferably 1 to 60% by mass, more preferably 5 to 40% by mass, and even more preferably 10 to 30% by mass, based on the total amount of resin components in the photosensitive resin composition.

[0067] <(C) Particles having an acrylic resin on the surface and an elastomer inside> The photosensitive resin composition of this embodiment contains, as component (C), particles having an acrylic resin on its surface and an elastomer inside. Component (C) can be any particle having an acrylic resin on its surface and an elastomer inside, and there are no particular restrictions on how the acrylic resin on the surface contacts the elastomer inside. In other words, the acrylic resin on the surface may simply be attached to or in contact with the elastomer inside, or it may be chemically bonded. Component (C) may be a so-called "core-shell type particle". Component (C) may be used alone or in combination of two or more types. The photosensitive resin composition of this embodiment contains component (C), which improves its dielectric properties and increases its adhesion strength to copper plating. The presence of an acrylic resin on the surface enhances compatibility with components (A) and (B), suppressing aggregation of component (C) within the composition. This, in turn, suppresses polarization at the interface with other components, leading to a reduction in the relative permittivity. Furthermore, the core elastomer effectively reduces the dielectric loss tangent. Regarding the adhesion strength to copper plating, it is presumed that when component (C) is sufficiently dispersed, its dissolution in the desmear solution during the desmear treatment creates concave depressions where component (C) was previously present. This increases the adhesion area to the copper plating and also creates an anchoring effect, resulting in improved adhesion strength to the copper plating.

[0068] The acrylic resin in component (C) is not particularly limited, but is preferably at least one selected from the group consisting of acrylic acid ester homopolymers, acrylic acid ester copolymers, methacrylic acid ester homopolymers, methacrylic acid ester copolymers, and copolymers of acrylic acid ester and methacrylic acid ester. Examples of ester moieties for acrylic acid esters and methacrylic acid esters include alkyl esters with 1 to 12 carbon atoms such as alkyl groups, cycloalkyl esters with 3 to 12 carbon atoms forming a ring such as cycloalkyl groups, aryl esters with 6 to 18 carbon atoms forming a ring such as phenyl groups, and aralkyl groups such as benzyl groups, as well as heterogroups in which some of these groups are substituted with heteroatoms. Examples of the aforementioned acrylic acid esters include methyl acrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-lauryl acrylate, 2-hydroxyethylhexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, tetrahydrofuryl acrylate, benzyl acrylate, and phenyl acrylate. Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, and isopropyl acrylate are preferred as acrylic acid esters, with methyl acrylate and ethyl acrylate being more preferred. Furthermore, examples of the methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, and allyl methacrylate. Among these, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and isopropyl methacrylate are preferred, and methyl methacrylate and ethyl methacrylate are more preferred.

[0069] The elastomer in component (C) is preferably soluble in the desmear treatment solution, and from that viewpoint, it is preferably at least one elastomer selected from the group consisting of a homopolymer of a compound having a conjugated double bond, a copolymer of compounds having conjugated double bonds, and a copolymer of a compound having a conjugated double bond and an aromatic hydrocarbon having an ethylenically unsaturated double bond. Examples of compounds having the aforementioned conjugated double bond include butadiene, isoprene, and chloroprene. Among these, from the viewpoint of dielectric properties, butadiene and isoprene are preferred as compounds having a conjugated double bond, with butadiene being more preferred. Examples of aromatic hydrocarbons having an ethylenically unsaturated double bond include styrene, α-methylstyrene, α-ethylstyrene, halogenated styrene, and p-methylstyrene. Among these, from the viewpoint of dielectric properties, styrene, α-methylstyrene, α-ethylstyrene, and p-methylstyrene are preferred as aromatic hydrocarbons having an ethylenically unsaturated double bond, with styrene being more preferred. (C) As the elastomer, from the viewpoint of dielectric loss tangent and adhesion strength with copper plating, a butadiene homopolymer or a copolymer of butadiene and styrene is preferred.

[0070] The volume-average particle diameter of component (C) is not particularly limited, but from the viewpoint that it is preferable for it to be fine particles, it is preferably 20 to 1,000 nm, more preferably 20 to 500 nm, even more preferably 20 to 100 nm, even more preferably 35 to 100 nm, particularly preferably 35 to 80 nm, and most preferably 40 to 65 nm. If the volume-average particle diameter of component (C) is 1,000 nm or less, deterioration of the via shape tends to be suppressed, and in particular, if the volume-average particle diameter of component (C) is 100 nm or less, the via shape tends to be maintained very well. Herein, in this specification, the volume-average particle diameter is the value obtained by measuring particles dispersed in a solvent with a refractive index of 1.38 using a submicron particle analyzer (Beckman Coulter, Inc., product name: N5) in accordance with the international standard ISO 13321, and is the particle diameter corresponding to 50% of the cumulative value (volume basis) in the particle size distribution.

[0071] The content of component (C) in the photosensitive resin composition of this embodiment is not particularly limited, but is preferably 5 to 45 volume%, more preferably 7 to 42 volume%, based on the total amount of resin components in the photosensitive resin composition, and may be 5 to 15 volume%, 20 to 45 volume%, or 35 to 45 volume%. If the content of component (C) is above the lower limit, the effect of improving dielectric properties tends to be sufficiently enhanced, and if it is below the upper limit, the decrease in strength of the photosensitive resin film can be effectively suppressed, so that the adhesive strength with copper plating tends to be sufficiently enhanced while maintaining the effect of improving dielectric properties.

[0072] <(D) Crosslinking agent> The photosensitive resin composition of this embodiment preferably further contains a crosslinking agent as component (D). The crosslinking agent is preferably one having two or more ethylenically unsaturated groups and no acidic substituents. The crosslinking agent reacts with the ethylenically unsaturated groups of component (A) to increase the crosslink density of the cured product. Therefore, the photosensitive resin composition of this embodiment tends to have improved heat resistance and dielectric properties by containing a crosslinking agent. (D) Component may be used alone or in combination of two or more components.

[0073] Examples of component (D) include difunctional monomers having two ethylenically unsaturated groups and polyfunctional monomers having three or more ethylenically unsaturated groups. Component (D) preferably contains the aforementioned polyfunctional monomers. The ethylenically unsaturated groups of component (D) are the same as those of component (A), and the preferred groups are also the same.

[0074] Examples of the aforementioned difunctional monomers include aliphatic di(meth)acrylates such as trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate; di(meth)acrylates having an alicyclic skeleton such as dicyclopentadiene di(meth)acrylate and tricyclodecanedimethanol di(meth)acrylate; and aromatic di(meth)acrylates such as 2,2-bis(4-(meth)acryloxypolyethoxypolypropoxyphenyl)propane and bisphenol A diglycidyl ether di(meth)acrylate. Among these, di(meth)acrylates having an alicyclic skeleton are preferred from the viewpoint of obtaining superior dielectric properties, and tricyclodecanedimethanol diacrylate is more preferred.

[0075] Examples of the polyfunctional monomers include (meth)acrylate compounds having a trimethylolpropane-derived skeleton such as trimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a tetramethylolmethane-derived skeleton such as tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate; (meth)acrylate compounds having a pentaerythritol-derived skeleton such as pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate; (meth)acrylate compounds having a dipentaerythritol-derived skeleton such as dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; (meth)acrylate compounds having a ditrimethylolpropane-derived skeleton such as ditrimethylolpropane tetra(meth)acrylate; and (meth)acrylate compounds having a diglycerin-derived skeleton. Among these, (meth)acrylate compounds having a trimethylolpropane-derived skeleton are preferred from the viewpoint of via resolution and adhesion strength to copper plating, and trimethylolpropanetri(meth)acrylate is more preferred. Here, the above-mentioned "(meth)acrylate compound having a skeleton derived from XXX" (where XXX is a compound name) refers to an esterified product of XXX and (meth)acrylic acid, and this esterified product also includes compounds modified with alkylene oxy groups.

[0076] If the photosensitive resin composition of this embodiment contains component (D), its content is not particularly limited, but from the viewpoint of heat resistance and dielectric properties, it is preferably 10 to 85 parts by mass, more preferably 25 to 80 parts by mass, even more preferably 40 to 75 parts by mass, and particularly preferably 50 to 70 parts by mass, per 100 parts by mass of component (A).

[0077] <(E) Inorganic filler> The photosensitive resin composition of this embodiment preferably further contains an inorganic filler as component (E). The photosensitive resin composition of this embodiment tends to obtain better dielectric properties and excellent low thermal expansion properties by containing an inorganic filler. (E) Component may be used alone or in combination of two or more types.

[0078] (E) Components include silica (SiO2), alumina (Al2O3), titania (TiO2), tantalum oxide (Ta2O5), zirconia (ZrO2), silicon nitride (Si3N4), barium titanate (BaO·TiO2), barium carbonate (BaCO3), magnesium carbonate (MgCO3), aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), lead titanate (PbO·TiO2), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga2O3), spinel (MgO·Al2O3), Examples include mullite (3Al2O3·2SiO2), cordierite (2MgO·2Al2O3 / 5SiO2), talc (3MgO·4SiO2·H2O), aluminum titanate (TiO2·Al2O3), yttria-containing zirconia (Y2O3·ZrO2), barium silicate (BaO·8SiO2), boron nitride (BN), calcium carbonate (CaCO3), barium sulfate (BaSO4), calcium sulfate (CaSO4), zinc oxide (ZnO), magnesium titanate (MgO·TiO2), hydrotalcite, mica, calcined kaolin, and carbon (C). Among these, silica is preferred from the viewpoint of heat resistance, low thermal expansion, and dielectric properties.

[0079] Component (E) may be surface-treated with a coupling agent such as a silane coupling agent to improve its dispersibility in the photosensitive resin composition. Examples of silane coupling agents include aminosilane coupling agents, epoxysilane coupling agents, phenylsilane coupling agents, alkylsilane coupling agents, alkenylsilane coupling agents, alkynylsilane coupling agents, haloalkylsilane coupling agents, siloxane coupling agents, hydrosilane coupling agents, silazane coupling agents, alkoxysilane coupling agents, chlorosilane coupling agents, (meth)acrylicsilane coupling agents, isocyanuratesilane coupling agents, ureidosilane coupling agents, mercaptosilane coupling agents, sulfidosilane coupling agents, isocyanatesilane coupling agents, and the like.

[0080] (E) Component may consist of only an inorganic filler surface-treated with one type of coupling agent, or it may consist of two or more inorganic fillers surface-treated with different coupling agents. When using a coupling agent, the method of addition may be a so-called integral blending method, in which the coupling agent is added after the inorganic filler has been blended into the photosensitive resin composition, or it may be a method in which the coupling agent is pre-treated on the inorganic filler by dry or wet surface treatment before blending.

[0081] The average particle size of component (E) is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, even more preferably 0.1 to 1 μm, and particularly preferably 0.15 to 0.7 μm, from the viewpoint of via resolution. Here, the average particle size of component (E) refers to the volume-average particle diameter, and the method for measuring the volume-average particle diameter is as described above.

[0082] If the photosensitive resin composition of this embodiment contains component (E), its content is not particularly limited, but is preferably 10 to 60% by mass, more preferably 20 to 60% by mass, even more preferably 30 to 55% by mass, and particularly preferably 35 to 50% by mass, based on the total solid content of the photosensitive resin composition. When the content of component (E) is above the lower limit, better dielectric properties and thermal expansion coefficient tend to be obtained, and when it is below the upper limit, better adhesion strength to copper plating and via resolution tend to be obtained.

[0083] <(F) Hardener> The photosensitive resin composition of this embodiment preferably further contains a curing agent as component (F). The photosensitive resin composition of this embodiment tends to have improved heat resistance, dielectric properties, etc. of the resulting cured product when it contains a curing agent. (F) Component may be used alone or in combination of two or more types.

[0084] Examples of component (F) include phenolic resin curing agents, acid anhydride curing agents, amine curing agents, hydrazide curing agents, and active ester curing agents. Among these, phenolic resin curing agents are preferred. Component (F) may be used alone or in combination of two or more. Examples of the phenolic resin curing agent include novolac-type phenolic resins such as phenol novolac resins and cresol novolac resins; and resol-type phenolic resins. Among these, novolac-type phenolic resins are preferred from the viewpoint of improving reliability. Commercially available novolac-type phenolic resins may be used. Examples of commercially available products include the phenol novolac resins "Phenolite® TD-2090" and "Phenolite® LA-7052", the triazine-containing phenol novolac resins "Phenolite® LA-1356" and "Phenolite® LA7050 series", and the triazine-containing cresol novolac resins "Phenolite® LA-3018" and "Phenolite® LA-3018-50P" (all manufactured by DIC Corporation). Examples of acid anhydride-based curing agents include phthalic anhydride, benzophenonetetracarboxylic dianhydride, and methylhymic anhydride. Examples of amine-based curing agents include dicyandiamide, diaminodiphenylmethane, and guanylurea. (F) Component is preferably a phenolic resin curing agent, more preferably a novolac-type phenolic resin, and even more preferably a novolac-type phenolic resin modified with melamine, benzoguanamine, etc. The hydroxyl group equivalent of the phenolic resin curing agent is not particularly limited, but is preferably 40 to 300 g / eq, may be 40 to 250 g / eq, may be 60 to 200 g / eq, may be 80 to 160 g / eq, or may be 100 to 140 g / eq. Here, the hydroxyl group equivalent (g / eq) can be determined by titration using the acetylation method with acetic anhydride.

[0085] When the photosensitive resin composition of this embodiment contains component (F), its content is not particularly limited, but from the viewpoint of further improving heat resistance and dielectric properties, it is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and even more preferably 0.10 to 1.2% by mass, based on the total amount of resin components of the photosensitive resin composition.

[0086] (G) Thermal polymerization initiator The photosensitive resin composition of this embodiment may contain a thermal polymerization initiator as component (G). While there are no particular restrictions on the thermal polymerization initiator, hydroperoxides such as diisopropylbenzene hydroperoxide "Permil P" (trade name, manufactured by NOF Corporation (hereinafter the same)), cumene hydroperoxide "Permil H", and t-butyl hydroperoxide "Perbutyl H" are also acceptable; α,α-bis(t-butylperoxy-m-isopropyl)benzene "Perbutyl P", dicumyl peroxide "Permil D", 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane "Perhexa 25B", t-butylcumyl peroxide "Perbutyl C", and di-t-butyl peroxide "Perbutyl D" are also acceptable. Examples include dialkyl peroxides such as 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyn-3 "Perhexyn 25B" and t-butylperoxy-2-ethylhexanoate "Perbutyl O"; ketone peroxides; peroxyketals such as n-butyl 4,4-di-(t-butylperoxy)valerate "Perhexa V"; diacyl peroxides; peroxydicarbonates; organic peroxides such as peroxyesters; and azo compounds such as 2,2'-azobisisobutylnitrile, 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). Among these, dialkyl peroxasides are preferred, and 2,5-dimethyl-2,5-bis(t-bitylperoxy)hexyn-3 is more preferred, from the viewpoint of not inhibiting photopolymerization and having a great effect in improving the physical properties and characteristics of the photosensitive resin composition. A single thermal polymerization initiator may be used alone, or two or more may be used in combination.

[0087] (Content of component (G)) If the photosensitive resin composition of this embodiment contains component (G), its content is not particularly limited, but is preferably 0.1 to 15% by mass, more preferably 1 to 10% by mass, and even more preferably 2 to 6% by mass, based on the total amount of resin components in the photosensitive resin composition. If the content of component (G) is above the lower limit, sufficient thermal curing tends to be possible, and if it is below the upper limit, good photosensitive properties and heat resistance tend to be obtained.

[0088] <(H) Photopolymerization initiator> The photosensitive resin composition of this embodiment preferably further contains a photopolymerization initiator as component (H). The photosensitive resin composition of this embodiment tends to have improved via resolution when it contains a photopolymerization initiator. Component (H) may be used alone or in combination of two or more types. From the viewpoint of developability, the photosensitive resin composition of this embodiment preferably contains two or more types of component (H), more preferably two to four types, and even more preferably two types.

[0089] The (H) component is not particularly limited as long as it can photopolymerize ethylenically unsaturated groups, and can be appropriately selected from commonly used photopolymerization initiators. (H) Components include benzoin compounds such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; 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)-1-butanone, 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane, and N,N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-A Examples include anthraquinone compounds such as minoanthraquinone; ketal compounds such as acetophenone dimethyl ketal and benzyl dimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; acylphosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine 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].

[0090] Among these, acylphosphine oxide compounds and oxime ester compounds are preferred, with bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyloxime) being more preferred. Acylphosphine oxide compounds have the advantage of reducing the absorption of active light such as ultraviolet rays, thereby allowing active light to reach the bottom of the photosensitive resin film more easily, and as a result, increasing the curability of the bottom of the exposed area and effectively suppressing undercuts. Oxime ester compounds have the advantage of high sensitivity and enabling high resolution. By using acylphosphine oxide compounds and oxime ester compounds in combination, the resolution of the vias is further improved.

[0091] If the photosensitive resin composition of this embodiment contains component (H), its content is not particularly limited, but is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, even more preferably 0.01 to 2% by mass, and particularly preferably 0.01 to 0.5% by mass, based on the total amount of resin components in the photosensitive resin composition. When the content of component (H) is above the lower limit, it tends to reduce the elution of the exposed area during development, and when it is below the upper limit, it tends to improve heat resistance.

[0092] <(I) Photosensitizer> The photosensitive resin composition of this embodiment may optionally contain a photosensitizer as component (I). Component (I) may be used alone or in combination of two or more types. (I) Examples of photosensitizers include thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; tertiary amines such as trialkylamines and triethanolamines; alkyl dialkylaminobenzoates such as ethyl N,N-dimethylaminobenzoate and amyl N,N-dimethylaminobenzoate; bis(dialkylamino)benzophenones such as 4,4'-bis(dimethylamino)benzophenone and 4,4'-bis(diethylamino)benzophenone; 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; and coumarin compounds. (I) As a photosensitizer, bis(dialkylamino)benzophenone is preferred, and 4,4'-bis(diethylamino)benzophenone is preferred, from the viewpoint of maintaining good via shape. Using bis(dialkylamino)benzophenone tends to reduce scattered light to unexposed areas, and as a result, good via shape can be maintained.

[0093] When the photosensitive resin composition of this embodiment contains component (I), its content is not particularly limited, but is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, even more preferably 0.1 to 2% by mass, and particularly preferably 0.3 to 1.5% by mass, based on the total amount of resin components in the photosensitive resin composition. When the content of component (I) is above the lower limit, the photocuring of the bottom of the exposed area is sufficient, and undercuts during via formation tend to be less likely to occur. When it is below the upper limit, it tends to suppress the via dimensions from becoming smaller than the target value.

[0094] <(J) Additives> The photosensitive resin composition of this embodiment may optionally contain various known and conventional additives such as pigments like phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, carbon black, and naphthalene black; adhesive aids like melamine; foam stabilizers like silicone compounds; polymerization inhibitors; thickeners; and flame retardants. The content of these (J) additives may be adjusted as appropriate according to their respective purposes, but each is preferably 0.01 to 5% by mass, but may also be 0.05 to 3% by mass, or 0.1 to 1% by mass, based on the total amount of resin components in the photosensitive resin composition.

[0095] <Diluent> The photosensitive resin composition of this embodiment may contain a diluent as needed. Examples of diluents include organic solvents. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ether compounds 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; esters such as ethyl acetate, butyl acetate, propylene glycol monoethyl ether acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One diluent may be used alone, or two or more may be used in combination.

[0096] If the photosensitive resin composition of this embodiment contains a diluent, its content may be appropriately selected to adjust the concentration of the total solid content in the photosensitive resin composition to a range of preferably 30 to 90% by mass, more preferably 40 to 80% by mass, and even more preferably 50 to 70% by mass. By adjusting the amount of diluent used to the above range, the coatability of the photosensitive resin composition is improved, and it becomes possible to form a higher-resolution pattern.

[0097] The photosensitive resin composition of this embodiment can be obtained by kneading and mixing each component in a roll mill, bead mill, or the like. Here, the photosensitive resin composition of this embodiment may be used in liquid form or in film form. When used in liquid form, there are no particular limitations on the application method of the photosensitive resin composition of this embodiment, but various application methods such as printing, spin coating, spray coating, jet dispensing, inkjet, and immersion coating are possible. Among these, printing and spin coating are preferred from the viewpoint of more easily forming the photosensitive layer. Furthermore, when used in film form, it can be used, for example, in the form of a photosensitive resin film as described later. In this case, a photosensitive layer of the desired thickness can be formed by laminating it onto a carrier film using a laminator or the like. It is preferable to use it in film form because it increases the manufacturing efficiency of multilayer printed circuit boards.

[0098] [Photosensitive resin film] The photosensitive resin film of this embodiment is formed using the photosensitive resin composition of this embodiment. This photosensitive resin film is useful as a photosensitive layer for forming an interlayer insulating layer. The photosensitive resin film of this embodiment may be provided on a carrier film.

[0099] The photosensitive resin film of this embodiment can be formed, for example, by applying and drying the photosensitive resin composition of this embodiment onto a carrier film using a known coating apparatus such as a comma coater, bar coater, kiss coater, roll coater, gravure coater, or die coater. Examples of carrier films include polyesters such as polyethylene terephthalate and polybutylene terephthalate; and polyolefins such as polypropylene and polyethylene. The thickness of the carrier film is preferably 5 to 100 μm, more preferably 10 to 60 μm, and even more preferably 15 to 45 μm.

[0100] Furthermore, the photosensitive resin film of this embodiment may also be provided with a protective film on the side opposite to the side in contact with the carrier film. As the protective film, polymer films such as polyethylene and polypropylene can be used. Alternatively, a polymer film similar to the carrier film described above may be used, or a different polymer film may be used.

[0101] The coating film formed by applying the photosensitive resin composition can be dried using a hot air dryer, a far-infrared dryer, or a near-infrared dryer. The drying temperature is preferably 60 to 150°C, more preferably 70 to 120°C, and even more preferably 80 to 110°C. The drying time is preferably 1 to 60 minutes, more preferably 2 to 30 minutes, and even more preferably 5 to 20 minutes. The residual diluent content in the photosensitive resin film after drying is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of avoiding the diffusion of the diluent during the manufacturing process of the multilayer printed circuit board.

[0102] The thickness (thickness after drying) of the photosensitive resin film (photosensitive layer) is not particularly limited, but from the viewpoint of thinning the multilayer printed circuit board, it is preferably 1 to 100 μm, more preferably 3 to 50 μm, and even more preferably 5 to 40 μm.

[0103] The photosensitive resin film of this embodiment is suitable as an interlayer insulating layer for multilayer printed circuit boards because it has excellent via resolution, adhesion strength to copper plating, and insulation reliability.

[0104] [Multilayer printed circuit board and method for manufacturing the same] The multilayer printed circuit board of this embodiment contains an interlayer insulating layer formed using the photosensitive resin composition or photosensitive resin film of this embodiment described above. Here, the expression "contains an interlayer insulating layer" includes cases where the interlayer insulating layer is contained as is, and cases where the interlayer insulating layer is contained after being subjected to various processes such as via formation, roughening, and wiring formation. The multilayer printed circuit board of this embodiment is not particularly limited in its manufacturing method, as long as it includes a step of forming an interlayer insulating layer using the photosensitive resin composition or photosensitive resin film of this embodiment. For example, it can be easily manufactured by the following method for manufacturing a multilayer printed circuit board of this embodiment.

[0105] A method for manufacturing a multilayer printed circuit board using the photosensitive resin film of this embodiment will be described with reference to Figure 1 as appropriate. The multilayer printed circuit board 100A can be manufactured, for example, by a manufacturing method including (1) to (4) below. (1): Laminating the photosensitive resin film of this embodiment to one or both sides of the circuit board (hereinafter referred to as "laminating step (1)"). (2): The photosensitive resin film laminated in step (1) is exposed to light and developed to form an interlayer insulating layer having vias (hereinafter referred to as "photovia formation step (2)"). (3) Roughening the vias and the interlayer insulating layer (hereinafter referred to as "roughening process (3)"). (4) Forming a circuit pattern on the interlayer insulating layer (hereinafter referred to as "circuit pattern formation step (4)"). In this specification, for convenience, a given operation may be referred to as "step XX," but step XX is not limited to the embodiments specifically described herein.

[0106] (Lamination process (1)) Lamination step (1) is a step of laminating the photosensitive resin film of this embodiment (photosensitive resin film for interlayer insulating layer) to one or both sides of a circuit board (substrate 101 having a circuit pattern 102) using a vacuum laminator. Examples of vacuum laminators include a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a roll-type dry coater manufactured by Hitachi, Ltd., and a vacuum laminator manufactured by Showa Denko Materials Electronics Co., Ltd.

[0107] If a protective film is provided on the photosensitive resin film, the protective film can be peeled off or removed, and then the photosensitive resin film can be laminated to the circuit board by applying pressure and heating while in contact with the circuit board. The lamination can be carried out, for example, by preheating the photosensitive resin film and circuit board as needed, at a pressure temperature of 70-130°C, a pressure of 0.1-1.0 MPa, and under reduced pressure of 20 mmHg (26.7 hPa) or less, but is not limited to these conditions. Furthermore, the lamination method may be batch-type or continuous-type using rolls. Finally, the photosensitive resin film laminated to the circuit board is cooled to near room temperature to form an interlayer insulating layer 103. If the photosensitive resin film has a carrier film, the carrier film may be peeled off at this stage, or it may be peeled off after exposure, as will be described later.

[0108] (Photovia formation process (2)) In the photovia formation step (2), at least a portion of the photosensitive resin film laminated to the circuit board is exposed to light, and then developed. The exposure causes the portion irradiated with active light to photocur, forming a pattern. There are no particular restrictions on the exposure method; for example, a method in which active light is irradiated in an image-like manner through a negative or positive mask pattern called artwork (mask exposure method) may be employed, or a method in which active light is irradiated in an image-like manner using direct drawing exposure methods such as LDI (Laser Direct Imaging) exposure method or DLP (Digital Light Processing) exposure method may be employed. Known light sources can be used as the light source for the active light. Specifically, examples of light sources include gas lasers such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers; solid-state lasers such as YAG lasers; and semiconductor lasers that effectively emit ultraviolet or visible light. The exposure dose is appropriately selected depending on the light source used and the thickness of the photosensitive layer, but for example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, for a photosensitive layer thickness of 1 to 100 μm, it is usually 10 to 1,000 mJ / cm². 2 A suitable level is 50-700 mJ / cm². 2 More preferably, 150-550 mJ / cm² 2 More preferably, 250-500 mJ / cm² 2 That is particularly preferable.

[0109] During development, the uncured portion of the photosensitive layer is removed from the substrate, and the photocured portion is formed on the substrate as an interlayer insulating layer. If a carrier film is present on the photosensitive layer, the carrier film is removed before removing the unexposed areas (development). There are two development methods: wet development and dry development. Either can be used, but wet development is widely used, and wet development can also be used in this embodiment. In the case of wet development, development is carried out using a developer solution corresponding to the photosensitive resin composition and a known development method. Development methods include the dip method, battle method, spray method, brushing, slapping, scraping, and agitation immersion. Among these, the spray method is preferred from the viewpoint of improving via resolution, and among spray methods, the high-pressure spray method is more preferred. Development may be carried out using one method, or it may be carried out in combination of two or more methods. The composition of the developer is appropriately selected according to the composition of the photosensitive resin composition. Examples include alkaline aqueous solutions, aqueous developers, and organic solvent-based developers, with alkaline aqueous solutions being preferred among these.

[0110] In the photovia formation process (2), after exposure and development, 0.2~10 J / cm 2 Degree (preferably 0.5~5J / cm) 2 The interlayer insulating layer may be further cured, and is preferable, by performing a post-UV cure with an exposure dose of (G) and a post-thermal cure at a temperature of approximately 60 to 250°C (preferably 120 to 200°C) as needed. If the photosensitive resin film contains (G) a thermal polymerization initiator, the post-thermal cure will cause component (G) to react sufficiently. As described above, an interlayer insulating layer having vias 104 is formed. There are no particular restrictions on the shape of the vias; in terms of cross-sectional shape, examples include squares and inverted trapezoids (where the top side is longer than the bottom side), and in terms of shape as viewed from the front (the direction in which the bottom of the via is visible), examples include circular and square shapes. In the photolithography method for forming vias in this embodiment, it is possible to form vias with an inverted trapezoidal cross-sectional shape (where the top side is longer than the bottom side), which is preferable because it improves the adhesion of the copper plating to the via wall surface.

[0111] The size (diameter) of the vias formed by this process can be less than 40 μm, and can even be 35 μm or less, or 30 μm or less, making them smaller in diameter than vias produced by laser processing. There is no particular lower limit to the size (diameter) of the vias formed by this process, but it may be 15 μm or more, or 20 μm or more. However, the size (diameter) of the vias formed by this process is not limited to less than 40 μm; for example, it may be arbitrarily selected within the range of 15 to 300 μm.

[0112] (Roughening process (3)) In the roughening process (3), the surfaces of the vias and interlayer insulating layers are roughened with a roughening solution. If smearing occurs in the photovia formation process (2), the smearing may be removed with the roughening solution. The roughening process and smear removal (desmearing) can be performed simultaneously. Examples of the above-mentioned roughening solutions include chromium / sulfuric acid roughening solution, alkaline permanganate roughening solution (for example, sodium permanganate roughening solution, etc.), and sodium fluoride / chromium / sulfuric acid roughening solution. The roughening treatment creates uneven anchors on the surfaces of the vias and interlayer insulating layers.

[0113] (Circuit pattern formation process (4)) The circuit pattern formation step (4) is a step in which a circuit pattern is formed on the interlayer insulating layer after the roughening treatment step (3). From the viewpoint of forming fine wiring, it is preferable to perform the formation of the circuit pattern by a semi-additive process. The semi-additive process forms the circuit pattern and simultaneously conducts the vias. In the semi-additive process, first, a seed layer 105 is formed by electroless copper plating using a palladium catalyst or the like on the entire surface of the via bottom, via wall, and interlayer insulating layer after the roughening process (3) described above. This seed layer is for forming a power supply layer for electroplating, and is preferably formed to a thickness of about 0.1 to 2.0 μm. If the thickness of the seed layer is 0.1 μm or more, it tends to suppress a decrease in connection reliability during electroplating, and if it is 2.0 μm or less, it tends to reduce the amount of etching required when flash etching the seed layer between wirings, thereby reducing damage to the wiring during etching.

[0114] The electroless copper plating process described above is carried out by depositing metallic copper on the surface of vias and interlayer insulating layers through a reaction between copper ions and a reducing agent. The electroless plating method and the electrolytic plating method described above can be any known method and are not particularly limited. Commercially available electroless copper plating solutions can be used, including "MSK-DK" from Attec Japan Co., Ltd. and "Surupap (registered trademark) PEA series" from Uemura Kogyo Co., Ltd.

[0115] After the electroless copper plating process described above, a dry film resist is heat-pressed onto the electroless copper plating using a roll laminator. The thickness of the dry film resist must be greater than the height of the wiring after electroplating, and from this viewpoint, a dry film resist with a thickness of 5 to 30 μm is preferred. As the dry film resist, the "FOTECH®" series manufactured by Showa Denko Materials Co., Ltd. is used. After the dry film resist is thermocompressed, for example, the dry film resist is exposed through a mask on which the desired wiring pattern is drawn. Exposure can be performed using the same apparatus and light source as those used when forming vias on the photosensitive resin film. After exposure, the dry film resist is developed using an alkaline aqueous solution to remove unexposed areas and form the resist pattern 106. After this, if necessary, the development residue of the dry film resist may be removed using plasma or the like. After development, electroplating is performed to form a copper circuit layer 107 and to perform via filling.

[0116] After electroplating copper, the dry film resist is removed using an alkaline aqueous solution or an amine-based stripping agent. After removing the dry film resist, the seed layer between the wiring is removed (flash etching). Flash etching is performed using an acidic solution such as sulfuric acid and hydrogen peroxide, and an oxidizing solution. After flash etching, palladium and other materials adhering to the areas between the wiring are removed as needed. Palladium removal can preferably be performed using an acidic solution such as nitric acid or hydrochloric acid.

[0117] After peeling off the dry film resist or after the flash etching process, a post-bake treatment is preferably performed. The post-bake treatment thoroughly heat-cures any unreacted thermosetting components, thereby improving insulation reliability, curing characteristics, and adhesion strength to the copper plating. Although the heat curing conditions vary depending on the type of resin composition, a curing temperature of 150 to 240°C and a curing time of 15 to 100 minutes are preferred. The post-bake treatment completes one step in the manufacturing process of a multilayer printed circuit board using the photovia method, and this process is repeated to manufacture substrates according to the required number of interlayer insulating layers. Then, a solder resist layer 108 is preferably formed on the outermost layer.

[0118] The above describes a method for manufacturing a multilayer printed circuit board using the photosensitive resin composition of this embodiment to form vias. However, since the photosensitive resin composition of this embodiment has excellent pattern resolution, it is also suitable for forming cavities for embedding chips or passive elements, for example. The cavities can be suitably formed, for example, in the description of the multilayer printed circuit board above, by making the drawing pattern when exposing the photosensitive resin film to form a pattern such that the desired cavity can be formed.

[0119] [Semiconductor Packages] This disclosure also provides a semiconductor package including the multilayer printed circuit board of this embodiment and semiconductor elements. The semiconductor package of this embodiment can be manufactured by mounting semiconductor elements such as semiconductor chips and memory at predetermined positions on the multilayer printed circuit board of this embodiment and sealing the semiconductor elements with a sealing resin or the like. [Examples]

[0120] The embodiment will be described in more detail below with reference to examples, but this disclosure is not limited to these examples. The weight-average molecular weight of component (A) was measured according to the method described below. Furthermore, the photosensitive resin compositions obtained in each example were evaluated for their properties by the method shown below.

[0121] <Method for measuring weight-average molecular weight> The weight-average molecular weight was measured using the GPC measuring device and measurement conditions described below, and the value converted using the calibration curve for standard polystyrene was defined as the weight-average molecular weight. The calibration curve was created using five sample sets of standard polystyrene ("PStQuick MP-H" and "PStQuick B," manufactured by Tosoh Corporation). (GPC measurement device) GPC system: High-speed GPC system "HCL-8320GPC", detector is differential refractometer or UV, manufactured by Tosoh Corporation. Column: TSKgel SuperMultipore HZ-H column (column length: 15cm, column inner diameter: 4.6mm), manufactured by Tosoh Corporation. (Measurement conditions) Solvent: Tetrahydrofuran (THF) Measurement temperature: 40℃ Flow rate: 0.35ml / min Sample concentration: 10 mg / THF 5 ml Injection volume: 20μl

[0122] [1. Evaluation of relative permittivity (Dk) and dielectric loss tangent (Df)] Two photosensitive resin films, with their protective films removed, are bonded together and exposed to light at 400 mJ / cm² using a flatbed exposure machine while retaining the carrier films on both sides. 2 (Wavelength 365nm), 2J / cm² using a UV conveyor type exposure machine. 2 The material was irradiated with light at a wavelength of 365 nm. This was then heat-treated in a hot air circulating dryer at 170°C for 1 hour, and cut into 7 cm x 10 cm pieces to be used as evaluation samples. The obtained evaluation samples were sealed with a desiccant and dried for more than 10 hours. The relative permittivity (Dk) and dielectric loss tangent (Df) were then measured in the 10 GHz band using the split-post dielectric resonator method (SPDR method).

[0123] [2. Evaluation of adhesion strength with copper plating] In each example and comparative example, the protective film was peeled off from the "photosensitive resin film formed by laminating a carrier film and a protective film," and the laminate was obtained by laminating it onto a 1.0 mm thick copper-clad laminated substrate using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") at a pressing pressure of 0.4 MPa, a press hot plate temperature of 75°C, a vacuum evacuation time of 25 seconds, a lamination press time of 25 seconds, and an atmospheric pressure of 4 kPa or less. The resulting laminate was subjected to 400 mJ / cm² exposure 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 was exposed at a wavelength of 365 nm. Next, an ultraviolet lithography system was used to expose it at 2 J / cm². 2 An evaluation laminate was obtained by exposing the copper-clad laminate to a wavelength of 365 nm and heating it at 170°C for 1 hour to form a cured material on the laminate.

[0124] Next, as a swelling solution, an aqueous solution of diethylene glycol monobutyl ether: 200 ml / L and sodium hydroxide: 5 g / L was prepared, and after heating to 70°C, the evaluation laminate was immersed for 10 minutes. Then, as a roughening solution, an aqueous solution of potassium permanganate: 60 g / L and sodium hydroxide: 40 g / L was prepared, and after heating to 70°C, the evaluation laminate was immersed for 15 minutes. Subsequently, an aqueous solution of neutralization solution (tin chloride (SnCl2): 30 g / L, hydrogen chloride: 300 ml / L) was prepared, and after heating to 40°C, the evaluation laminate was immersed for 5 minutes to reduce potassium permanganate. In this manner, the surface of the cured evaluation laminate was desmeared. Next, the surface of the desmeared evaluation laminate cured material was degreased and cleaned by treating it with the 60°C alkaline cleaner "Cleaner Securigant 902" (manufactured by Atotec Japan Co., Ltd., product name) for 5 minutes. After cleaning, the desmeared cured material was treated with the 23°C pre-dip solution "Pre-dip Neogant B" (manufactured by Atotec Japan Co., Ltd., product name) for 1 minute. Subsequently, the cured material was treated with the 35°C activator solution "Activator Neogant 834" (manufactured by Atotec Japan Co., Ltd., product name) for 5 minutes, and then treated with the 30°C reducing solution "Reducer Neogant WA" (manufactured by Atotec Japan Co., Ltd., product name) for 5 minutes. The resulting evaluation laminate was placed in a chemical copper solution ("Basic Print Gant MSK-DK", "Copper Print Gant MSK", "Stabilizer Print Gant MSK" (all manufactured by Atotec Japan Co., Ltd., product names)) and electroless plating was performed until the plating thickness reached approximately 0.5 μm. After the electroless plating, an annealing treatment was performed at 120°C for 30 minutes to remove any remaining hydrogen gas. Subsequently, copper sulfate electroplating was performed, followed by an annealing treatment at 180°C for 60 minutes to form a conductive layer with a thickness of 25 μm.

[0125] The evaluation laminate, in which the conductive layer was formed as described above, was measured for vertical peel strength at 23°C in accordance with JIS C6481 (1996), and evaluated according to the following evaluation criteria. A: The adhesive strength with copper plating was 0.40 kN / m or higher. B: The adhesive strength to the copper plating was between 0.30 kN / m and less than 0.40 kN / m. C: The adhesive strength with copper plating was less than 0.30 kN / m.

[0126] [3. Evaluation of via shape] In each example and comparative example, the protective film was peeled off from the "photosensitive resin film formed by laminating a carrier film and a protective film," and the laminate was obtained by laminating it onto a 1.0 mm thick copper-clad laminate substrate using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") at a pressing pressure of 0.4 MPa, a press hot plate temperature of 75°C, a vacuum evacuation time of 25 seconds, a lamination press time of 25 seconds, and an atmospheric pressure of 4 kPa or less. The resulting laminate was subjected to a step tablet and via evaluation mask using an i-line stepper (UX-7, manufactured by Ushio Inc.) on the carrier film, at a concentration of 400 mJ / cm². 2 The film was exposed to light at a wavelength of 365 nm. After peeling off the carrier film, it was developed using a spray developer at 30°C with a 1% by mass sodium carbonate aqueous solution for 40 seconds.

[0127] [Preparation of photosensitive resin composition] Examples 1-3, Comparative Examples 1-5 (1) Production of photosensitive resin composition The compositions were prepared according to the formulations shown in Table 1 (the units of the values ​​in the table are parts by mass, and in the case of solutions or dispersions, the amounts are on a solid content basis), 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. (2) Manufacturing of photosensitive resin film A 16 μm thick polyethylene terephthalate film (manufactured by Teijin Limited, product name "G2-16") was used as a carrier film. The photosensitive resin composition prepared in each example was applied to the carrier film so that the film thickness after drying was 25 μm. The film was then dried at 100°C for 10 minutes using a hot air convection dryer to form a photosensitive resin film (photosensitive layer). Subsequently, a polyethylene film (manufactured by Tamapoly Co., Ltd., product name "NF-15") was laminated as a protective film onto the surface of the photosensitive resin film (photosensitive layer) opposite to the side in contact with the carrier film, thereby producing a photosensitive resin film with the carrier film and protective film laminated together. The prepared photosensitive resin film was used to perform each evaluation according to the method described above. The results are shown in Table 1.

[0128] [Table 1]

[0129] The components used in Table 1 are as follows: [(A) Photopolymerizable compounds having ethylenically unsaturated groups and acidic substituents] • "ZXR-1807H" (manufactured by Nippon Kayaku Co., Ltd., weight-average molecular weight: 2,000)

[0130] [(B) Thermosetting resin] • "MIR-3000" (manufactured by Nippon Kayaku Co., Ltd., biphenylaralkyl maleimide)

[0131] [(C) Particles having an acrylic resin on the surface and an elastomer inside] • "KaneAce (registered trademark) MZ-120" (manufactured by Kaneka Corporation; core-shell particles with polybutadiene particles as the core and acrylic resin as the shell; volume-average particle diameter: 50 nm) • "KaneAce (registered trademark) MX-EXP" (manufactured by Kaneka Corporation; core-shell particles with a styrene-butadiene copolymer core and an acrylic resin shell; volume-average particle diameter: 50 nm)

[0132] [(C') component] <(C) Particles other than component> • "X52-7030" (manufactured by Shin-Etsu Chemical Co., Ltd., silicone particles, volume-average particle size: 50 nm) • "BC05R" (manufactured by Showa Denko Materials Co., Ltd., polystyrene particles, volume-average particle size: 50 nm) • "2527A" (manufactured by JSR Corporation, styrene-butadiene copolymer particles, volume-average particle size: 85 nm) <Elastomer (non-particle)> • "Ricon(registered trademark) 100" (manufactured by Clay Valley, a styrene-butadiene thermoplastic elastomer)

[0133] [(D) Crosslinking agent] • "TMPTA" (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate)

[0134] [(E) Inorganic filler] • E1: Molten spherical silica with an average particle size of 0.5 μm (coupling agent treated product)

[0135] [(F) Hardener] • "Phenolite (registered trademark) LA-7052" (manufactured by DIC Corporation, novolac-type phenolic resin modified with melamine, benzoguanamine, etc., hydroxyl group equivalent: 120g / eq)

[0136] [(G) Thermal polymerization initiator] G1: α,α-bis(t-butylperoxy-m-isopropyl)benzene

[0137] [(H) Photopolymerization initiator] ·H1;1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyloxime) (oxime ester compound) • H2; Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (acylphosphine compound)

[0138] [(I) Photosensitizer] • I1;4,4'-Bis(diethylamino)benzophenone (manufactured by Hodogaya Chemical Co., Ltd.)

[0139] [(J) Additives] 4-t-butylcatechol (polymerization inhibitor) • "SH-193" (manufactured by Dow Toray Industries, Inc., silicone-based foam stabilizer)

[0140] Table 1 shows that the photosensitive resin compositions of Examples 1 to 3 of this embodiment possessed excellent dielectric properties while also improving adhesion strength to copper plating. Furthermore, the photosensitive resin compositions of Examples 1 to 3 of this embodiment also exhibited good via shape. In the photosensitive resin film prepared in Example 1, the cured surface after desmear treatment, which was performed to evaluate the adhesion strength to copper plating, showed depressions in the areas where component (C) was present, suggesting that component (C) dissolved in the desmear treatment solution. This is thought to have contributed to the improvement in adhesion strength to copper plating. On the other hand, in Comparative Example 1, the photosensitive resin composition that did not contain component (C) had a high dielectric loss tangent and insufficient adhesion strength to the copper plating. In Comparative Example 2, which used silicone particles instead of component (C), the reduction in dielectric loss tangent was insufficient, and the adhesion strength to the copper plating was also insufficient. In Comparative Example 3, which used polystyrene particles instead of component (C), there was an effect in reducing the dielectric loss tangent, but the adhesion strength to the copper plating was insufficient. In addition, in the photosensitive resin films prepared in Comparative Examples 1 to 3, no depressions were observed on the surface of the cured product after desmear treatment, which was performed to evaluate the adhesion strength to the copper plating. Furthermore, in Comparative Example 4, which used styrene-butadiene copolymer particles, which are single elastomer particles, instead of component (C), the relative permittivity was high, the adhesion strength to the copper plating was insufficient, and the via shape deteriorated. This is presumed to be because the surface of the polybutadiene particles did not adhere well to components (A) and (B), etc. (i.e., the compatibility was not good), which led to an increase in the relative permittivity. Furthermore, it is presumed that the uneven distribution of polybutadiene particles within the photosensitive resin film prevented a sufficient anchoring effect, leading to a decrease in adhesive strength with the copper plating. The deterioration of the via shape is presumed to be due to the poor compatibility between the polybutadiene particles and other components, resulting in the generation of numerous large-sized aggregated particles within the photosensitive resin film. In Comparative Example 5, where a non-particulate polybutadiene-based thermoplastic elastomer was used instead of component (C), there was an effect in reducing the dielectric loss tangent, but the adhesive strength with the copper plating was insufficient, and the via shape deteriorated further. [Explanation of Symbols]

[0141] 100A Multilayer Printed Circuit Board 101 circuit board 102 Circuit Patterns 103 Interlayer insulating layer 104 Beer (Beer Hall) 105 Seed Layer 106 Resist Patterns 107 Copper circuit layer 108 Solder Resist Layers

Claims

1. (A) Photopolymerizable compounds having an ethylenically unsaturated group and an acidic substituent, (B) thermosetting resin, (C) Particles having an acrylic resin on the surface and an elastomer inside, and (H) Photopolymerization initiator, A photosensitive resin composition containing, The aforementioned component (A) is an acid-modified vinyl group-containing epoxy resin obtained by reacting (a1) an epoxy resin with (a2) an organic acid containing an ethylenically unsaturated group to (a3) ​​a polybasic acid anhydride containing a saturated or unsaturated group, and contains an alicyclic structure represented by the following general formula (A-1), and the content of component (A) is 25 to 80% by mass on a basis of the total amount of resin components in the photosensitive resin composition. A photosensitive resin composition wherein component (C) does not have curable reactive groups on its surface. 【Chemistry 1】 (In the formula, R Ａ１ m represents an alkyl group having 1 to 12 carbon atoms and may be substituted anywhere in the alicyclic structure. １ (This is an integer between 0 and 6. * indicates a connection site to another structure.)

2. The photosensitive resin composition according to claim 1, wherein the acrylic resin is at least one selected from the group consisting of an acrylic acid ester homopolymer, an acrylic acid ester copolymer, a methacrylic acid ester homopolymer, a methacrylic acid ester copolymer, and a copolymer of an acrylic acid ester and a methacrylic acid ester.

3. The photosensitive resin composition according to claim 1 or 2, wherein the elastomer is at least one elastomer selected from the group consisting of a homopolymer of a compound having a conjugated double bond, a copolymer of compounds having conjugated double bonds, and a copolymer of a compound having a conjugated double bond and an aromatic hydrocarbon having an ethylenically unsaturated double bond.

4. The photosensitive resin composition according to any one of claims 1 to 3, wherein the volume-average particle size of component (C) is 20 to 1,000 nm.

5. The photosensitive resin composition according to any one of claims 1 to 4, wherein the content of component (C) is 5 to 45% by volume based on the total solid content of the photosensitive resin composition.

6. The photosensitive resin composition according to any one of claims 1 to 5, wherein the (B) component comprises biphenylaralkyl type maleimide.

7. Furthermore, the photosensitive resin composition according to any one of claims 1 to 6, further comprising (D) a crosslinking agent.

8. Furthermore, the photosensitive resin composition according to any one of claims 1 to 7, further comprising (E) an inorganic filler.

9. Furthermore, the photosensitive resin composition according to any one of claims 1 to 8, further comprising (F) a curing agent.

10. Furthermore, the photosensitive resin composition according to any one of claims 1 to 9, further comprising (G) a thermal polymerization initiator.

11. The photosensitive resin composition according to any one of claims 1 to 10, comprising two or more of the (H) photopolymerization initiators.

12. A photosensitive resin composition according to any one of claims 1 to 11, used for forming one or more selected from the group consisting of photovias and interlayer insulating layers.

13. A photosensitive resin film comprising the photosensitive resin composition according to any one of claims 1 to 12.

14. A multilayer printed circuit board comprising an interlayer insulating layer formed using a photosensitive resin composition according to any one of claims 1 to 12, or a photosensitive resin film according to claim 13.

15. A semiconductor package comprising a multilayer printed circuit board according to claim 14 and a semiconductor element.

16. A method for manufacturing a multilayer printed circuit board, comprising the following (1) to (4). (1) Laminating the photosensitive resin film described in claim 13 to one or both sides of a circuit board. (2) Forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in (1) above. (3) Roughen the vias and the interlayer insulating layer. (4) Forming a circuit pattern on the interlayer insulating layer.

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