JP2021032916A - Photosensitive resin composition, photosensitive resin film, multilayer printed board and semiconductor package, as well as method for manufacturing multilayer printed board - Google Patents

Abstract

To provide a photosensitive resin composition having excellent dielectric properties and a method for producing the same, and provide a photosensitive resin film, a multilayer printed board and a method for producing the same, and a semiconductor package each of which uses the photosensitive resin composition.SOLUTION: The present invention relates to a photosensitive resin composition that contains (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, and (B) a maleimide compound having an N-substituted maleimide group, and a method for producing the same. The present invention also relates to a photosensitive resin film, a multilayer printed board and a method for producing the same, and a semiconductor package each of which uses the photosensitive resin composition.SELECTED DRAWING: None

Description

The present invention 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.

In recent years, the miniaturization and high performance of electronic devices have progressed, and the density of multilayer printed wiring boards has been increasing due to the increase in the number of circuit layers and the miniaturization of wiring. In particular, the 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 insulating film and interlayer connection are used. Further reduction in the diameter of vias (also called via holes) is required.

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 (for example, see Patent Document 1) in which an interlayer insulating layer and a conductor circuit layer are sequentially laminated. .. For multi-layer printed wiring boards, the semi-additive method, in which the circuit is formed by plating as the circuit becomes finer, has become the mainstream.
In the conventional semi-additive method, 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) After that, the substrate is subjected to electroless copper plating treatment, a pattern is formed using a resist, and then electrolytic copper plating is performed to form a copper circuit layer. (4) Next, a copper circuit has been formed by peeling off the resist and performing flash etching of the electroless layer.

As described above, laser processing has been the mainstream method for forming vias in the interlayer insulating layer formed by curing a thermosetting resin film, but the diameter of vias can be reduced by laser irradiation using a laser processing machine. Is reaching its limits. Furthermore, in the formation of vias by a laser processing machine, it is necessary to form each via hole one by one, and when it is necessary to provide a large number of vias due to high density, it takes a lot of time to form the vias and the manufacturing is performed. There is a problem of inefficiency.

Under such circumstances, as a method capable of forming a large number of vias at once, an acid-modified vinyl group-containing epoxy resin, a photopolymerizable compound, a photopolymerization initiator, an inorganic filler, and a silane compound are contained, and the inorganic filler is contained. A method of collectively forming a plurality of small-diameter vias by a photolithography method using a photosensitive resin composition having a content of 10 to 80% by mass has been proposed (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 7-304931 JP-A-2017-116652

Patent Document 2 has a problem of suppressing a decrease in adhesiveness with plated copper due to the use of a photosensitive resin composition instead of a conventional thermosetting resin composition as a material for an interlayer insulating layer or a surface protective layer. Furthermore, it is said that the resolution of the via and the adhesion to the substrate and the chip component of the silicon material are also issues, and these have been solved.

By the way, in recent years, substrate materials have been required to be applied to fifth-generation mobile communication system (5G) antennas in which radio waves in the frequency band exceeding 6 GHz are used and millimeter-wave radars in which radio waves in the frequency band of 30 to 300 GHz are used. Has been done. For that purpose, it is necessary to develop a resin composition having further improved dielectric properties in the 10 GHz band or higher. However, with the technique of Patent Document 2, it has been difficult to further improve the dielectric properties while maintaining good properties.

Therefore, the subject of the present invention is a photosensitive resin composition having excellent dielectric properties and a method for producing the same, 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. Is to provide.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the following invention, and have completed the present invention.
That is, the present invention relates to the following [1] to [18].
[1] (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, and (B) a maleimide compound having an N-substituted maleimide group.
A photosensitive resin composition containing.
[2] The above-mentioned [1], wherein the (A) photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent contains an alicyclic structure represented by the following general formula (A-1). Photosensitive resin composition.

(Wherein, R ^A1 represents an alkyl group having 1 to 12 carbon atoms, where optionally substituted on .m ¹ in said alicyclic structure is an integer of 0 to 6. * Are the other structures It is the binding site of.)
[3] The photosensitive resin composition according to the above [1] or [2], wherein the (A) photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent has an acid value of 20 to 200 mgKOH / g. Stuff.
[4] (B) The photosensitive compound according to any one of [1] to [3] above, wherein the maleimide compound having an N-substituted maleimide group is an aromatic maleimide compound having two or more N-substituted maleimide groups. Resin composition.
[5] Content ratio of the (A) photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent to the (B) maleimide compound having an N-substituted maleimide group [(A) / (B) ] Is 1 to 10 on a mass basis, according to any one of the above [1] to [4].
[6] The photosensitive resin composition according to any one of the above [1] to [5], which further contains (C) an epoxy resin.
[7] The photosensitive resin composition according to the above [6], which contains a bisphenol type epoxy resin and an aralkyl type epoxy resin as the (C) epoxy resin.
[8] Further, (D) the photosensitive property according to any one of [1] to [7] above, which contains a cross-linking agent having two or more ethylenically unsaturated groups and no acidic substituent. Resin composition.
[9] The photosensitive resin according to the above [8], which contains (D1) a cross-linking agent having two or more (meth) acryloyl groups and no acidic substituent as the (D) cross-linking agent. Composition.
[10] The photosensitive agent according to the above [8] or [9], wherein the (D) cross-linking agent contains (D2) a cross-linking agent having two or more allyl groups and no acidic substituent. Resin composition.
[11] The above-mentioned [1] to [10], further comprising (E) an elastomer and, as the (E) elastomer, an elastomer having an ethylenically unsaturated group and an acidic substituent. Photosensitive resin composition.
[12] The photosensitive resin composition according to any one of the above [1] to [11], which further contains (F) a photopolymerization initiator.
[13] The photosensitive resin according to any one of the above [1] to [12], which further contains (G) an inorganic filler in an amount of 10 to 70% by mass based on the total solid content of the photosensitive resin composition. Composition.
[14] The photosensitive resin composition according to any one of the above [1] to [13], which is used for forming one or more kinds selected from the group consisting of a photovia and an interlayer insulating layer.
[15] A photosensitive resin film comprising the photosensitive resin composition according to any one of the above [1] to [14].
[16] A multilayer composed of the photosensitive resin composition according to any one of the above [1] to [14] or an interlayer insulating layer formed by using the photosensitive resin film according to the above [15]. Printed wiring board.
[17] A semiconductor package in which a semiconductor element is mounted on the multilayer printed wiring board according to the above [16].
[18] A method for manufacturing a multilayer printed wiring board, which comprises the following steps (1) to (4).
Step (1): A step of laminating the photosensitive resin film according to the above [15] on one side or both sides of a circuit board.
Step (2): A step of forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in the step (1).
Step (3): A step of roughening the via and the interlayer insulating layer.
Step (4): A step of forming a circuit pattern on the interlayer insulating layer.

According to the present invention, a photosensitive resin composition having excellent dielectric properties and a method for producing the same, 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 are provided. can do.

It is a schematic diagram which shows one aspect of the manufacturing process of the multilayer printed wiring board which uses the cured product of the photosensitive resin composition of this embodiment as at least one of a surface protective film and an interlayer insulating film.

In the numerical range described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. Further, in the present specification, the content of each component in the photosensitive resin composition is present in the photosensitive resin composition when a plurality of substances corresponding to each component are present, unless otherwise specified. It means the total content of the plurality of substances.
The present invention also includes aspects in which the items described in the present specification are arbitrarily combined.

As used herein, the term "resin component" means the total amount of components that do not contain an inorganic filler and a diluent that may be contained as needed, which will be described later.
Further, in the present specification, the "solid content" is a non-volatile content excluding volatile substances such as water and a solvent contained in the photosensitive resin composition, and when the resin composition is dried, it is used. It shows components that remain without volatilization, and also includes liquid, starch syrup-like and wax-like substances at room temperature around 25 ° C.

In the present specification, "(meth) acrylate" means "acrylate or methacrylate", and other similar terms have the same meaning.

[Photosensitive resin composition]
The photosensitive resin composition according to one embodiment of the present invention (hereinafter, may be simply referred to as the present embodiment) is a photosensitive resin composition.
(A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, and (B) a maleimide compound having an N-substituted maleimide group.
It is a photosensitive resin composition containing.
In addition, in this specification, the said component may be abbreviated as a component (A), a component (B) and the like, respectively, and other components may be abbreviated in the same manner.

Since the photosensitive resin composition of the present embodiment has excellent dielectric properties and is suitable for via formation by photolithography (also referred to as photo via formation), one or more kinds selected from the group consisting of photo vias and interlayer insulating layers. It is suitable for the formation of. Therefore, the present invention also provides a photosensitive resin composition for forming a photovia composed of the photosensitive resin composition of the present embodiment and a photosensitive resin composition for an interlayer insulating layer composed of the photosensitive resin composition of the present embodiment. To do.
The photosensitive resin composition of the present embodiment is suitable for a negative photosensitive resin composition.
Hereinafter, each component that can be contained in the photosensitive resin composition will be described in detail.

<(A) Photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent>
The photosensitive resin composition of the present embodiment contains a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent as the component (A).
As the component (A), one type may be used alone, or two or more types may be used in combination.

The component (A) is a compound that exhibits photopolymerizability by having an ethylenically unsaturated group.
Examples of the ethylenically unsaturated group contained in the component (A) include photopolymerization of a vinyl group, an allyl group, a propargyl group, a butenyl group, an ethynyl group, a phenylethynyl group, a maleimide group, a nadiimide group, a (meth) acryloyl group and the like. Examples include functional groups exhibiting sex. Among these, the (meth) acryloyl group is preferable from the viewpoint of reactivity and via resolution.

The component (A) has an acidic substituent from the viewpoint of enabling alkaline development.
Examples of the acidic substituent contained in the component (A) include a carboxy group, a sulfonic acid group, and a phenolic hydroxyl group. Among these, a carboxy group is preferable from the viewpoint of via resolution.
The acid value of the component (A) is preferably 20 to 200 mgKOH / g, more preferably 40 to 180 mgKOH / g, still more preferably 70 to 150 mgKOH / g, and particularly preferably 90 to 120 mgKOH / g. When the acid value of the component (A) is at least the above lower limit value, the solubility of the photosensitive resin composition in a dilute alkaline solution tends to be excellent, and when it is at least the above upper limit value, the dielectric property of the cured product is excellent. There is a tendency. The acid value of the component (A) can be measured by the method described in Examples.
In addition, two or more kinds of (A) components having different acid values may be used in combination, and in that case, the acid value of the load average of the acid values of the two or more kinds of (A) components is within any of the above ranges. Is preferable.

The weight average molecular weight (Mw) of the component (A) is preferably 600 to 30,000, more preferably 800 to 25,000, and even more preferably 1,000 to 18,000. When the weight average molecular weight (Mw) of the component (A) is in the above range, the adhesiveness to the plated copper, the heat resistance, and the insulation reliability tend to be excellent. Here, in the present specification, the weight average molecular weight is a value measured according to the following method.
<Measurement method of weight average molecular weight>
The weight average molecular weight was measured with the following GPC measuring device and measurement conditions, and the value converted using the standard polystyrene calibration curve was taken as the weight average molecular weight. A calibration curve was prepared using a set of 5 samples (“PStQuick MP-H” and “PStQuick B”, manufactured by Tosoh Corporation) as standard polystyrene.
(GPC measuring device)
GPC device: High-speed GPC device "HCL-8320GPC", detector is differential refractometer or UV, manufactured by Tosoh Corporation Column: Column TSKgel SuperMultipore HZ-H (column length: 15 cm, column inner diameter: 4.6 mm), Tosoh Corporation Made by company (measurement conditions)
Solvent: tetrahydrofuran (THF)
Measurement temperature: 40 ° C
Flow rate: 0.35 ml / min Sample concentration: 10 mg / THF 5 ml
Injection volume: 20 μl

The component (A) preferably contains an alicyclic skeleton from the viewpoint of dielectric properties.
As the alicyclic skeleton contained in the component (A), an alicyclic skeleton having 5 to 20 ring-forming carbon atoms is preferable from the viewpoints of via resolution, adhesion strength with plated copper, and reliability of electrical insulation. An alicyclic skeleton having 5 to 18 carbon atoms is more preferable, an alicyclic skeleton having 6 to 18 ring-forming carbon atoms is further preferable, and an alicyclic skeleton having 8 to 14 ring-forming carbon atoms is particularly preferable. The alicyclic skeleton of numbers 8 to 12 is most preferable.
Further, the alicyclic skeleton preferably consists of two or more rings, more preferably 2 to 4 rings, from the viewpoints of via resolution, adhesive strength with plated copper, and reliability of electrical insulation. It is more preferably composed of three rings. Examples of the alicyclic skeleton having two or more rings include a norbornane skeleton, a decalin skeleton, a bicycloundecane skeleton, and a dicyclopentadiene skeleton. Among these, the dicyclopentadiene skeleton is preferable from the viewpoint of the resolution of vias, the adhesive strength with plated copper, and the reliability of electrical insulation.
From the same viewpoint, the component (A) preferably contains an alicyclic structure represented by the following general formula (A-1).

(Wherein, R ^A1 represents an alkyl group having 1 to 12 carbon atoms, where optionally substituted on .m ¹ in the alicyclic structure is an integer of 0 to 6. * Are the other structures It is the binding site of.)

In the general formula ^(A1), the alkyl group having 1 to 12 carbon atoms represented by ^{R A1,} for example, a methyl group, an ethyl group, n- propyl group, an isopropyl group, n- butyl group, isobutyl group, t -Butyl group, n-pentyl group and the like can be mentioned. As the alkyl group, an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group is further preferable.
m ¹ is an integer of 0 to 6, preferably an integer of 0 to 2, and more preferably 0.
If m ¹ is an integer from 2 to 6, to each of the plurality of R ^A1 may be the same or may be different. Further, the plurality of ^RA1s may be substituted on the same carbon atom to the extent possible, or may be substituted on different carbon atoms.
* Is a binding site to another structure and may be bonded by any carbon atom on the alicyclic skeleton, but the carbon atom represented by 1 or 2 in the following general formula (A-1'). And, preferably, they are bonded at the carbon atom represented by either 3 or 4.

^(Wherein, R A1, ^{m 1} and * are the same as those in the general formula (A1).)

The component (A) is a compound obtained by modifying (a1) an epoxy resin with (a2) an ethylenically unsaturated group-containing organic acid from the viewpoint of via resolution and adhesion to plated copper [hereinafter, (A'). Sometimes referred to as an ingredient. ], It is preferable that the epoxy resin contains an acid-modified vinyl group obtained by reacting (a3) a saturated group or an unsaturated group-containing polybasic acid anhydride. Here, the "acid modification" of the acid-modified vinyl group-containing epoxy resin means having an acidic substituent, the "vinyl group" means an ethylenically unsaturated group, and the "epoxy resin" is used as a raw material. This means that an epoxy resin is used, 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 the component (A) obtained from (a1) an epoxy resin, (a2) an ethylenically unsaturated group-containing organic acid, and (a3) a saturated group or an unsaturated group-containing polybasic acid anhydride will be described.

((A1) Epoxy resin)
(A1) The epoxy resin is preferably an epoxy resin having two or more epoxy groups.
(A1) As the epoxy resin, one type may be used alone, or two or more types may be used in combination.
(A1) The epoxy resin is classified into a glycidyl ether type epoxy resin, a glycidyl amine type epoxy resin, a glycidyl ester type epoxy resin, and the like. Among these, a glycidyl ether type epoxy resin is preferable.

(A1) Epoxy resins can be classified into various epoxy resins depending on the difference in the main skeleton. For example, epoxy resins having an alicyclic skeleton, novolac type epoxy resins, bisphenol type epoxy resins, aralkyl type epoxy resins, etc. It can be classified into other epoxy resins and the like. Among these, an epoxy resin having an alicyclic skeleton and a novolac type epoxy resin are preferable.

-Epoxy resin with an alicyclic skeleton-
The alicyclic skeleton of the epoxy resin having an alicyclic skeleton is described in the same manner as the alicyclic skeleton of the component (A) described above, and the preferred embodiment is also the same.
As the epoxy resin having an alicyclic skeleton, an epoxy resin represented by the following general formula (A-2) is preferable.

^{(Wherein, R A1} represents an alkyl group having 1 to 12 carbon atoms, .m ¹ may ^{.R A2} wherever substituted in the alicyclic skeleton is represents an alkyl group having 1 to 12 carbon atoms An integer of 0 to 6, m ² is an integer of 0 to 3, and n is a number of 0 to 50.)

In formula ^{(A-2), R A1} is the same as ^{R A1} in the general formula (A1), which is also the same preferred embodiment.
Examples of the alkyl group having 1 to 12 carbon atoms ^{which R A2} represents the In formula (A2), for example, a methyl group, an ethyl group, n- propyl group, an isopropyl group, n- butyl group, isobutyl group, t- Examples thereof include a butyl group and an n-pentyl group. As the alkyl group, an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group is further preferable.
Formula (A-2) ^{m 1} in the general formula (A-1) in the same as ^{m 1} of, and their preferred embodiments are also the same.
Formula ^{(A-2) m} 2 in is an integer of 0 to 3, preferably 0 or 1, more preferably 0.
N in the general formula (A-2) represents the number of repetitions of the structural unit in parentheses, and is a number from 0 to 50. Usually, the epoxy resin is a mixture of structural units having different numbers of repetitions in parentheses. In that case, n is represented by the average value of the mixture. As n, a number of 0 to 30 is preferable.

As the epoxy resin having an alicyclic skeleton, a commercially available product may be used, and examples of the commercially available product include XD-1000 (manufactured by Nippon Kayaku Co., Ltd., trade name) and EPICLON (registered trademark) HP-7200. (Manufactured by DIC Corporation, product name) and the like.

-Novolac type epoxy resin-
Examples of the novolak type epoxy resin include bisphenol novolak type epoxy resin, bisphenol F novolak type epoxy resin, bisphenol S novolak type epoxy resin and the like; phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl. Examples thereof include novolak type epoxy resin and naphthol novolak type epoxy resin.
As the novolak type epoxy resin, an epoxy resin having a structural unit represented by the following general formula (A-3) is preferable.

(Wherein, R ^A3 represents a hydrogen atom or a methyl group, Y ^A1 each .2 one R ^A3 represents a hydrogen atom or a glycidyl group may be the same independently of one .2 which may be different Y ^A1 At least one of them shows a glycidyl group.)

R ^A3, from the viewpoint of adhesion with the resolution and plating copper vias, is preferably both hydrogen atoms. From the same viewpoint as this, Y ^A1 is preferably either a glycidyl group.
The number of structural units of the structural unit in the epoxy resin (a1) having the structural unit represented by the general formula (A-3) is 1 or more, preferably 10 to 100, and more preferably 15 to 100. The number is 80, more preferably 15-70. When the number of structural units is within the above range, the adhesive strength, heat resistance and insulation reliability tend to be improved.
In formula ^(A3), both the ^{R A3} is a hydrogen ^atom, those of ^{Y A1} are all glycidyl groups, as EXA-7376 series (manufactured by DIC Corporation, trade name), ^{also, R A3} is both are a methyl group, those of Y ^A1 is both a glycidyl group, EPON SU8 series (Mitsubishi Chemical Co., Ltd., trade name) is commercially available as.

Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 3,3', 5,5'-tetramethyl-4,4'-diglycidyloxydiphenylmethane and the like. Can be mentioned.
Examples of the aralkyl type epoxy resin include phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol aralkyl type epoxy resin and the like.
Other epoxy resins include, for example, stillben type epoxy resin, naphthalene type epoxy resin, naphthylene ether type epoxy resin, biphenyl type epoxy resin, dihydroanthracene type epoxy resin, cyclohexanedimethanol type epoxy resin, trimethylol type epoxy resin, and the like. Examples thereof include an alicyclic epoxy resin, an aliphatic chain epoxy resin, a heterocyclic epoxy resin, a spiro ring-containing epoxy resin, and a rubber-modified epoxy resin.

((A2) Ethylene unsaturated group-containing organic acid)
(A2) As the ethylenically unsaturated group-containing organic acid, an ethylenically unsaturated group-containing monocarboxylic acid is preferable.
Examples of the ethylenically unsaturated group contained in the component (a2) include the same ethylenically unsaturated groups contained in the component (A).
Examples of the component (a2) include acrylic acid, a dimer of acrylic acid, and acrylic acids such as methacrylic acid, β-flufurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanoesteric acid. Derivative: Semi-ester compound which is a reaction product of hydroxyl group-containing acrylate and dibasic acid anhydride; Vinyl group-containing monoglycidyl ether or semi-ester which is a reaction product of vinyl group-containing monoglycidyl ester and dibasic acid anhydride. Examples include compounds.
As the component (a2), one type may be used alone, or two or more types may be used in combination.

The semiester compound is, for example, one or more ethylenically unsaturated group-containing compounds selected from the group consisting of a hydroxyl group-containing acrylate, a vinyl group-containing monoglycidyl ether, and a vinyl group-containing monoglycidyl ester, and a dibasic acid anhydride. And, it is obtained by reacting. The reaction is preferably carried out by reacting an ethylenically unsaturated group-containing compound with a dibasic acid anhydride in equimolar amounts.

Examples of the hydroxyl group-containing acrylate used for the synthesis of the semiester compound include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and trimethylolpropane di. Examples thereof include (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol penta (meth) acrylate.
Examples of the vinyl group-containing monoglycidyl ether include glycidyl (meth) acrylate and the like.

The dibasic acid anhydride used in the synthesis of the semiester compound may contain a saturated group or an unsaturated group. Examples of the dibasic acid anhydride include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. , Ethylhexahydrophthalic anhydride, phthalic anhydride and the like.

In the reaction between the component (a1) and the component (a2), the amount of the component (a2) used is preferably 0.6 to 1.05 equivalents, more preferably 1.05 equivalents, relative to 1 equivalent of the epoxy group of the component (a1). It is 0.7 to 1.02 equivalents, more preferably 0.8 to 1.0 equivalents. By reacting the component (a1) and the component (a2) at the above ratio, the photopolymerizability of the component (A) is improved, and the resolution of vias of the obtained photosensitive resin composition tends to be improved. ..

It is preferable that the component (a1) and the component (a2) are dissolved in an organic solvent and reacted.
Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether and dipropylene. Glycol ethers such as 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. ; Petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha can be mentioned. As the organic solvent, one type may be used alone, or two or more types may be used in combination.

For the reaction between the component (a1) and the component (a2), it is preferable to use a catalyst for accelerating the reaction. Examples of the catalyst include amine-based catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and benzyltrimethylammonium iodide; triphenylphosphine. And the like, phosphine-based catalysts and the like can be mentioned. Among these, a phosphine-based catalyst is preferable, and triphenylphosphine is more preferable. One type of catalyst may be used alone, or two or more types may be used in combination.
When a catalyst is used, the amount used is preferably 0.01 to 10 parts by mass, based on 100 parts by mass of the total of the components (a1) and (a2) from the viewpoint of obtaining an appropriate reaction rate. It is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 2 parts by mass.

In the reaction between the component (a1) and the component (a2), it is preferable to use a polymerization inhibitor for the purpose of preventing polymerization during the reaction. Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol and the like. As the polymerization inhibitor, one type may be used alone, or two or more types 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, based on 100 parts by mass of the total of the component (a1) and the component (a2). It is 8.8 parts by mass, more preferably 0.1 to 0.5 parts by mass.

The reaction temperature of the component (a1) and the component (a2) is preferably 60 to 150 ° C., more preferably 80 to 120 ° C., still more preferably, from the viewpoint of uniformly proceeding the reaction while obtaining sufficient reactivity. It is 90 to 110 ° C.

As described above, the component (A') obtained by reacting the component (a1) and the component (a2) is the component (a1) when an ethylenically unsaturated group-containing monocarboxylic acid is used as the component (a2). It has a hydroxyl group formed by a cycloaddition reaction between the epoxy group of (a2) and the carboxy group of the component (a2). Next, by further reacting the component (A') with the component (a3), the hydroxyl group of the component (A') (including the hydroxyl group originally present in the component (a1)) and the component (a3) An acid-modified vinyl group-containing epoxy resin in which the acid anhydride group is semi-esterified can be obtained.

((A3) Polybasic acid anhydride)
The component (a3) may contain a saturated group or an unsaturated group. Examples of the component (a3) include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Ethylhexahydrophthalic anhydride, itaconic anhydride and the like can be mentioned. Among these, tetrahydrophthalic anhydride is preferable from the viewpoint of via resolution. As the component (a3), one type may be used alone, or two or more types may be used in combination.

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

The reaction temperature of the component (A') and the component (a3) is preferably 50 to 150 ° C., more preferably 60 to 120 ° C., still more preferably, from the viewpoint of uniformly proceeding the reaction while obtaining sufficient reactivity. Is 70 to 100 ° C.

The content of the component (A) in the photosensitive resin composition of the present embodiment is not particularly limited, but from the viewpoint of heat resistance, dielectric properties and chemical resistance, the content of the component (A) is based on the total amount of the resin component of the photosensitive resin composition. It is preferably 10 to 80% by mass, more preferably 20 to 60% by mass, and even more preferably 30 to 50% by mass.

<(B) Maleimide compound having an N-substituted maleimide group>
The photosensitive resin composition of the present embodiment contains (B) a maleimide compound having an N-substituted maleimide group. By containing the component (B) in the photosensitive resin composition of the present embodiment, the priority tangent of the cured product can be lowered.
As the component (B), one type may be used alone, or two or more types may be used in combination.

As the component (B), a maleimide compound having two or more N-substituted maleimide groups is preferable.
Examples of the component (B) include bis (4-maleimidephenyl) methane, bis (4-maleimidephenyl) ether, bis (4-maleimidephenyl) sulfone, and 3,3'-dimethyl-5,5'-diethyl-. 2 in molecules such as 4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, 2,2-bis [4- (4-maleimidephenoxy) phenyl] propane, etc. Aromatic bismaleimide compound having one N-substituted maleimide group; Aromatic polymaleimide compound having three or more N-substituted maleimide groups in the molecule such as polyphenylmethane maleimide and biphenyl aralkyl type maleimide; 1,6-bis Examples thereof include aliphatic maleimide compounds such as maleimide- (2,2,4-trimethyl) hexane and pyrrolylonic acid binder type long-chain alkylbismaleimide.
Among these, an aromatic maleimide compound having two or more N-substituted maleimide groups is preferable, and an aromatic polymaleimide compound is more preferable, from the viewpoint of heat resistance and dielectric properties.

As the component (B), a maleimide compound represented by the following general formula (B-1) is preferable.

(In the formula, X ^B1 is a divalent organic group.)

As the ^{divalent organic group represented by X B1, the} group represented by the following general formulas (B-2), (B-3), (B-4), (B-5) or (B-6) is used. Can be mentioned.

^{(Wherein, R B1} is, .P1 an aliphatic hydrocarbon group, or a halogen atom having 1 to 5 carbon atoms is an integer of 0-4.)

Examples of the aliphatic hydrocarbon group of 1 to 5 carbon atoms which R ^B1 represents, for example, a methyl group, an ethyl group, n- propyl group, an isopropyl group, n- butyl group, an isobutyl group, t- butyl group, n- pentyl Group etc. can be mentioned. The aliphatic hydrocarbon group may be an aliphatic hydrocarbon group having 1 to 3 carbon atoms or a methyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
p1 is an integer of 0 to 4, and may be an integer of 0 to 2, 0 or 1, or 0 from the viewpoint of availability. When p1 is an integer of 2 or more, the plurality of ^RB1s may be the same or different.

(In the formula, R ^B2 and R ^B3 are independently aliphatic hydrocarbon groups or halogen atoms ^{having 1 to 5 carbon atoms. X B2} is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. Alkylidene group, ether group, sulfide group, sulfonyl group, carbonyloxy group, keto group, single bond, or divalent group represented by the following general formula (B-3-1). P2 and p3 are respectively. Independently, it is an integer from 0 to 4.)

Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms and the halogen atom represented by ^RB2 and ^RB3 are the same as those in the case of ^RB1. 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.
Examples of the alkylene group having 1 to 5 carbon atoms represented by X ^B2 include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, a 1,5-pentamethylene group and the like. Can be mentioned. The alkylene group may be an alkylene group having 1 to 3 carbon atoms from the viewpoint of compatibility with other resins, adhesiveness with a conductor, heat resistance, low thermal expansion and mechanical properties, and may be a methylene group. It may be.
Examples of the alkylidene group having 2 to 5 carbon atoms represented by X ^B2 include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group and an isopentylidene group. Among these, an isopropylidene group may be used from the viewpoints of compatibility with other resins, adhesiveness with conductors, heat resistance, low thermal expansion, and mechanical properties.
Among the above options, X ^B2 may be an alkylene group having 1 to 5 carbon atoms or an alkylidene group having 2 to 5 carbon atoms.
p2 and p3 are independently integers of 0 to 4, and from the viewpoint of availability, both may be integers of 0 to 2 and may be 0 or 2. If p2 or p3 is an integer of 2 or more, plural R ^B2 together or R ^B3 each other may each be the same or different.
The divalent group represented by the general formula (B-3-1) represented by ^{X B2 is as follows.}

(In the formula, R ^B4 and R ^B5 are independently aliphatic hydrocarbon groups or halogen atoms ^{having 1 to 5 carbon atoms. X B3} is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. It is an alkylidene group, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group or a single bond. P4 and p5 are independently integers of 0 to 4).

The aliphatic hydrocarbon group having 1 to 5 carbon atoms and the halogen atom represented by ^RB4 and ^RB5 will be described in the same manner as in the case of ^RB1.
Examples of the alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by X ^B3 include the same alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented ^{by X B2.} Be done.
As X ^B3 , an alkylidene group having 2 to 5 carbon atoms may be selected from the above options.
p4 and p5 are each independently an integer of 0 to 4, and from the viewpoint of availability, both may be an integer of 0 to 2, may be 0 or 1, and may be 0. You may. If p4 or p5 is an integer of 2 or more, among the plurality of R ^B4 each other or R ^B5 may each be the same or different.

(In the formula, p6 is an integer from 0 to 10.)

From the viewpoint of availability, p6 may be an integer of 0 to 5, or may be an integer of 0 to 3.

(In the formula, p7 has a number of 0 to 5.)

From the viewpoint of availability, p7 may be a number from 0 to 4, or may be a number from 0 to 3.

^{(Wherein, R B6} and ^{R B7} are each independently, .P8 an aliphatic hydrocarbon group having a hydrogen atom or a C1-5 is an integer of 1 to 8.)

The aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by ^RB6 and ^RB7 will be described in the same manner as in the case of ^RB1.
p8 is an integer of 1 to 8, and may be an integer of 1 to 3 or 1.
When p8 is an integer of 2 or more, the plurality of ^RB6s or ^RB7s may be the same or different from each other.

The content ratio [(A) / (B)] of the (A) photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent to the above (B) maleimide compound having an N-substituted maleimide group is particularly high. Although not limited, it is preferably 1 to 10, more preferably 2 to 7, and even more preferably 3 to 5 on a mass basis from the viewpoint of heat resistance and dielectric properties.

The content of the component (B) in the photosensitive resin composition of the present embodiment is not particularly limited, but from the viewpoint of heat resistance and dielectric properties, it is preferably 1 to 1 based on the total amount of the resin component of the photosensitive resin composition. It is 30% by mass, more preferably 4 to 20% by mass, and even more preferably 7 to 15% by mass.

<(C) Epoxy resin>
The photosensitive resin composition of the present embodiment preferably further contains an epoxy resin as the component (C).
Since the photosensitive resin composition of the present embodiment contains the epoxy resin (C), the heat resistance tends to be further improved in addition to the improvement of the adhesiveness to the plated copper and the insulation reliability.
As the epoxy resin (C), one type may be used alone, or two or more types may be used in combination.

The epoxy resin (C) is preferably an epoxy resin having two or more epoxy groups. Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins and the like. Among these, a glycidyl ether type epoxy resin is preferable.

(C) Epoxy resins can be classified into various epoxy resins depending on the difference in the main skeleton. For example, bisphenol type epoxy resin, novolac type epoxy resin, aralkyl type epoxy resin, epoxy resin having an alicyclic skeleton, etc. It can be classified into other epoxy resins and the like.
Examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 3,3', 5,5'-tetramethyl-4,4'-diglycidyloxydiphenylmethane and the like. Can be mentioned.
Examples of the novolak type epoxy resin include bisphenol novolak type epoxy resin, bisphenol F novolak type epoxy resin, bisphenol S novolak type epoxy resin and the like; phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl. Examples thereof include novolac type epoxy resin and naphthol novolac type epoxy resin.
Examples of the aralkyl type epoxy resin include phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol aralkyl type epoxy resin and the like.
Examples of the epoxy resin having an alicyclic skeleton include a dicyclopentadiene type epoxy resin and the like.
Other epoxy resins include, for example, stillben type epoxy resin, naphthalene type epoxy resin, naphthylene ether type epoxy resin, biphenyl type epoxy resin, dihydroanthracene type epoxy resin, cyclohexanedimethanol type epoxy resin, trimethylol type epoxy resin, and the like. Examples thereof include an alicyclic epoxy resin, an aliphatic chain epoxy resin, a heterocyclic epoxy resin, a spiro ring-containing epoxy resin, and a rubber-modified epoxy resin.

Among these, as the (C) epoxy resin, a bisphenol type epoxy resin, a novolac type epoxy resin, and an aralkyl type epoxy resin are preferable from the viewpoint of insulation reliability, dielectric properties, heat resistance, and adhesion to plated copper. , 3', 5,5'-tetramethyl-4,4'-diglycidyloxydiphenylmethane, naphthol novolac type epoxy resin, biphenyl aralkyl type epoxy resin are more preferable.
As the epoxy resin (C), it is preferable to use a bisphenol type epoxy resin and a novolac type epoxy resin or an aralkyl type epoxy resin in combination from the viewpoint of insulation reliability, dielectric properties, heat resistance and adhesion to plated copper. It is more preferable to contain a bisphenol type epoxy resin and an aralkyl type epoxy resin, and it is possible to contain 3,3', 5,5'-tetramethyl-4,4'-diglycidyloxydiphenylmethane and a biphenyl aralkyl type epoxy resin. More preferred.
(C) When the epoxy resin contains a bisphenol type epoxy resin and a novolac type epoxy resin or an aralkyl type epoxy resin, the content ratio of both [bisphenol type epoxy resin / novolac type epoxy resin or aralkyl type epoxy resin] is particularly limited. However, it is preferably 1.0 to 4.0, more preferably 1.5 to 3.0, and even more preferably 2.0 to 2.5.

The equivalent ratio [epoxy group / acidic substituent] of the acidic substituent of the component (A) to the epoxy group of the component (C) in the photosensitive resin composition of the present embodiment is not particularly limited, but the insulation reliability, From the viewpoint of dielectric properties, heat resistance and adhesion to plated copper, it is preferably 0.5 to 6.0, more preferably 0.7 to 4.0, still more preferably 0.8 to 2.0, and particularly preferably. Is 0.9 to 1.2.

When the photosensitive resin composition of the present embodiment contains (C) epoxy resin, the content of component (C) is not particularly limited, but insulation reliability, dielectric properties, heat resistance and adhesiveness to plated copper are not particularly limited. From the above viewpoint, it is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, and further preferably 10 to 20% by mass based on the total amount of the resin component of the photosensitive resin composition.

<(D) Cross-linking agent>
The photosensitive resin composition of the present embodiment further has a cross-linking agent having two or more ethylenically unsaturated groups as a component (D) and no acidic substituent [hereinafter, simply (D) cross-linking agent. May be called. ] Is preferably contained. The cross-linking agent (D) reacts with the ethylenically unsaturated group contained in the component (A), the N-substituted maleimide group contained in the component (B), and the like to increase the cross-linking density of the cured product. Therefore, the photosensitive resin composition of the present embodiment tends to have further improved heat resistance and dielectric properties by containing the (D) cross-linking agent.
(D) As the cross-linking agent, one type may be used alone, or two or more types may be used in combination.

As the (D) cross-linking agent, one or more selected from the group consisting of a bifunctional monomer having two ethylenically unsaturated groups and a polyfunctional monomer having three or more ethylenically unsaturated groups is preferable. A bifunctional monomer having an ethylenically unsaturated group is more preferable. Examples of the ethylenically unsaturated group contained in the (D) cross-linking agent include the same ethylenically unsaturated group contained in the component (A).
Among these, (meth) acryloyl group and allyl group are preferable. A cross-linking agent having a (meth) acryloyl group as an ethylenically unsaturated group mainly functions as a cross-linking agent for component (A), and a cross-linking agent having an allyl group as an ethylenically unsaturated group mainly functions as a cross-linking agent for component (B). Functions as a cross-linking agent for ethylene.
That is, the (D) cross-linking agent has (D1) two or more (meth) acryloyl groups, a cross-linking agent having no acidic substituent, and (D2) two or more allyl groups. It is preferable to contain at least one selected from the group consisting of a cross-linking agent having no acidic substituent.

((D1) Crosslinking agent having two or more (meth) acryloyl groups and no acidic substituents)
Examples of the component (D1) include a bifunctional (meth) acrylate monomer having two (meth) acryloyl groups, a polyfunctional (meth) acrylate monomer having three or more (meth) acryloyl groups, and the like.
Examples of the bifunctional (meth) acrylate monomer include aliphatic di (meth) acrylates such as trimethyl propandi (meth) acrylate, polypropylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate; tricyclodecandy. Di (meth) acrylate having an alicyclic skeleton such as methanol diacrylate; 2,2-bis (4- (meth) acryloxipolyethoxypolypropoxyphenyl) propane, bisphenol A diglycidyl ether di (meth) acrylate, etc. Aromatic di (meth) acrylate and the like can be mentioned.
Among these, di (meth) acrylate having an alicyclic skeleton is preferable, and tricyclodecanedimethanol diacrylate is more preferable, from the viewpoint of obtaining a lower dielectric loss tangent.

Examples of the polyfunctional (meth) acrylate monomer include a (meth) acrylate compound having a skeleton derived from trimethylolpropane such as trimethylolpropane tri (meth) acrylate; tetramethylolmethane tri (meth) acrylate, tetramethylolmethanetetra ( A (meth) acrylate compound having a tetramethylolmethane-derived skeleton such as meta) acrylate; a (meth) acrylate compound having a pentaerythritol-derived skeleton such as pentaerythritol trimethylolpropane (meth) acrylate and pentaerythritol tetra (meth) acrylate; Pentaerythritol Penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and other dipentaerythritol-derived (meth) acrylate compounds; ditrimethylolpropane tetra (meth) acrylate and other ditrimethylolpropane-derived skeleton (Meta) acrylate compound; (meth) acrylate compound having a skeleton derived from diglycerin and the like can be mentioned. Among these, from the viewpoint of improving chemical resistance after photocuring, a (meth) acrylate compound having a skeleton derived from dipentaerythritol is preferable, and dipentaerythritol penta (meth) acrylate is more preferable.
Here, the above-mentioned "(meth) acrylate compound having a skeleton derived from XXX" (wherein, XXX is a compound name) means an esterified product of XXX and (meth) acrylic acid, and the esterified product Also includes compounds modified with an alkyleneoxy group.

When the photosensitive resin composition of the present embodiment contains the component (D1), the content thereof is not particularly limited, but is preferable with respect to 100 parts by mass of the component (A) from the viewpoint of heat resistance and dielectric properties. Is 10 to 100 parts by mass, more preferably 30 to 80 parts by mass, still more preferably 50 to 70 parts by mass.

((D2) A cross-linking agent having two or more allyl groups and no acidic substituent)
As the component (D2), a nadiimide compound having two or more allyl groups is preferably mentioned. The nadiimide compound having two or more allyl groups is preferably a bisallyl nadiimide compound represented by the following general formula (D-1).

(In the formula, X ^D1 represents a divalent organic group having 1 to 20 carbon atoms.)

Examples of the divalent organic group having 1 to 20 carbon atoms represented by X ^D1 include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, or a divalent linking group in which these are combined.
Examples of the alkylene group include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, a 1,5-pentamethylene group and the like.
Examples of the alkenylene group include a vinylene group, a propenylene group, a butenylene group and the like.
Examples of the alkynylene group include an ethynylene group and a propynylene group.
Examples of the arylene group include a phenylene group and a naphthylene group.
Among these, as X ^D1 , an alkylene group or an arylene group is preferable.
The ^{number of carbon atoms of the divalent organic group having 1 to 20 carbon atoms represented by X D1} is preferably 2 to 18, more preferably 4 to 16, and even more preferably 6 to 14.

The X ^D1 is preferably a divalent organic group represented by the following general formula (D-2) and a divalent organic group represented by the following general formula (D-3), and is dielectric loss tangent. It is more preferable that it is a divalent organic group represented by the following general formula (D-3) from the viewpoint of lowering the value.

(X ^D2 , X ^D3 and X ^D4 are independently alkylene groups having 1 to 10 carbon atoms. * Indicates a binding site.)

Examples of the alkylene group having 1 to 10 carbon atoms represented by X ^D2 , X ^D3 and X ^D4 include the same as those exemplified in the description of ^{X D1.} Among these, a methylene group is preferable.
The ^{carbon number of the alkylene group having 1 to 10 carbon atoms represented by X D2} , X ^D3 and X ^D4 is preferably 1 to 5, more preferably 1 to 3, further preferably 1 or 2, and particularly preferably 1. is there.

When the photosensitive resin composition of the present embodiment contains the component (D2), the content thereof is not particularly limited, but is preferable with respect to 100 parts by mass of the component (B) from the viewpoint of heat resistance and dielectric properties. Is 10 to 200 parts by mass, more preferably 50 to 150 parts by mass, and even more preferably 80 to 120 parts by mass.

The molecular weight of the (D) cross-linking agent is preferably less than 1,000, more preferably 150 to 800, still more preferably 200 to 700, and particularly preferably 250 to 600.

When the photosensitive resin composition of the present embodiment contains (D) a cross-linking agent, the total content of the (D) cross-linking agent is not particularly limited, but from the viewpoint of heat resistance and dielectric properties, the photosensitive resin composition Based on the total amount of the resin component of the above, it is preferably 5 to 70 parts by mass, more preferably 10 to 60 parts by mass, and further preferably 20 to 40 parts by mass.

<(E) Elastomer>
The photosensitive resin composition of the present embodiment preferably further contains an elastomer as the component (E). Since the photosensitive resin composition of the present embodiment contains (E) elastomer, the adhesiveness to the plated copper tends to be further improved. Further, the (E) elastomer has the effect of suppressing a decrease in flexibility and adhesiveness with plated copper due to internal strain (internal stress) of the cured product due to curing shrinkage of the component (A). ..
(E) One type of elastomer may be used alone, or two or more types may be used in combination.

(E) The elastomer may have a reactive functional group at the end of the molecule or in the molecular chain.
Examples of the reactive functional group include an acid anhydride group, an epoxy group, a hydroxyl group, a carboxy group, an amino group, an amide group, an isocyanato group, an acrylic group, a methacryl group and a vinyl group. Among these, an acid anhydride group, an epoxy group, a hydroxyl group, a carboxy group, an amino group and an amide group are preferable, and an acid anhydride group and an epoxy group are more preferable from the viewpoint of via resolution and adhesion to plated copper. Preferably, an acid anhydride group is more preferred.
Examples of the acid anhydride group include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadicic anhydride, glutaric anhydride, and the like. It is preferably an acid anhydride group derived from dimethylglutaric anhydride, diethylglutaric anhydride, succinic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, etc., and an acid anhydride group derived from maleic anhydride. Is more preferable.
(E) When the elastoma has an acid anhydride group, the number of acid anhydride groups in one molecule is preferably 1 to 10, more preferably 1 to 6, from the viewpoint of the resolution and dielectric properties of vias. , More preferably 2-5.

The photosensitive resin composition of the present embodiment preferably contains an elastomer having an ethylenically unsaturated group and an acidic substituent as the (E) elastomer.
Examples of the acidic substituent and the ethylenically unsaturated group include the same as the acidic substituent and the ethylenically unsaturated group contained in the component (A). Among these, the elastoma (E) preferably has an acid anhydride group as an acidic substituent and a 1,2-vinyl group described later as an ethylenically unsaturated group.

Examples of the (E) elastomer include polybutadiene-based elastomers, polyester-based elastomers, styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyamide-based elastomers, acrylic-based elastomers, silicone-based elastomers, and derivatives of these elastomers. .. Among these, a polybutadiene-based elastomer is preferable from the viewpoint of improving the adhesiveness with the plated copper, and further improving the compatibility with the resin component and the solubility.

The polybutadiene-based elastomer preferably includes a structure consisting of a 1,4-trans form and a 1,4-cis form containing a 1,2-vinyl group.
As described above, the polybutadiene-based elastoma is preferably a polybutadiene-based elastoma having an acid anhydride group modified with an acid anhydride from the viewpoint of via resolution, and is an acid anhydride derived from maleic anhydride. More preferably, it is a polybutadiene-based elastoma having a physical group.
Polybutadiene-based elastomers are available as commercial products, and specific examples thereof include, for example, "POLYVEST (registered trademark) MA75", "POLYVEST (registered trademark) EP MA120" (all manufactured by Ebonic, trade name), and the like. Examples thereof include "Ricon (registered trademark) 130MA8", "Ricon (registered trademark) 131MA5", and "Ricon (registered trademark) 184MA6" (all manufactured by Clay Valley Co., Ltd., trade name).

The polybutadiene-based elastomer is a polybutadiene having an epoxy group [hereinafter, may be referred to as an epoxidized polybutadiene] from the viewpoint of adhesion to plated copper. ] May be.
The epoxidized polybutadiene is preferably an epoxidized polybutadiene represented by the following general formula (E-1) from the viewpoint of adhesiveness and flexibility with plated copper.

(In the formula, a, b and c represent the ratio of structural units in parentheses, respectively, where a is 0.05 to 0.40, b is 0.02 to 0.30, and c is 0.30. ~ 0.80, and further satisfies a + b + c = 1.00 and (a + c)> b. Y represents the number of structural units in square brackets and is an integer of 10 to 250.)

In the above general formula (E-1), the order of joining each structural unit in square brackets is random. That is, the structural unit shown on the left, the structural unit shown in the center, and the structural unit shown on the right may be interchanged, and they are referred to as (a), (b), and (c), respectively. When expressed by,-[(a)-(b)-(c)]-[(a)-(b)-(c)-]-,-[(a)-(c)-(b)]- [(A)-(c)-(b)-]-,-[(b)-(a)-(c)]-[(b)-(a)-(c)-]-,-[( a)-(b)-(c)]-[(c)-(b)-(a)-]-,-[(a)-(b)-(a)]-[(c)-(b) )-(C)-]-,-[(c)-(b)-(c)]-[(b)-(a)-(a)-]-, and so on.
From the viewpoint of adhesiveness and flexibility with plated copper, a is preferably 0.10 to 0.30, b is preferably 0.10 to 0.30, and c is preferably 0.40 to 0.80. .. Further, from the same viewpoint as this, y is preferably an integer of 30 to 180.
In the above general formula (E-1), as a commercially available product of epoxidized polybutadiene having integers of a = 0.20, b = 0.20, c = 0.60, and y = 10 to 250, "Epolide (Epolide (Epolide) Registered trademark) PB3600 ”(manufactured by Daicel Corporation) and the like.

Examples of the polyester-based elastomer include those obtained by polycondensing a dicarboxylic acid or a derivative thereof and a diol compound or a derivative thereof.
Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which the hydrogen atom of these aromatic nuclei is substituted with a methyl group, an ethyl group, a phenyl group, or the like; Examples thereof include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid and dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.
Examples of the diol compound include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and 1,10-decanediol; 1,4-cyclohexanediol and the like. Aliphatic diols; examples thereof include aromatic diols such as bisphenol A, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) propane, and resorcin.
Further, as the polyester-based elastomer, a multi-block copolymer having an aromatic polyester (for example, polybutylene terephthalate) portion as a hard segment component and an aliphatic polyester (for example, polytetramethylene glycol) portion as a soft segment component is preferable. Can be mentioned. There are various grades of multi-block copolymers depending on the types, ratios, and molecular weights of hard segments and soft segments. Specific examples include "Hitrel (registered trademark)" (DuPont Toray Industries, Inc.), "Perprene (registered trademark)" (Toyo Spinning Co., Ltd.), and "Esper (registered trademark)" (Hitachi Kasei Co., Ltd. ) Etc. can be mentioned.

When the photosensitive resin composition of the present embodiment contains (E) elastomer, the content of (E) elastomer is not particularly limited, but from the viewpoint of heat resistance and adhesion to plated copper, the photosensitive resin composition Based on the total amount of the resin component of the product, it is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, and further preferably 3 to 7% by mass.

<(F) Photopolymerization Initiator>
The photosensitive resin composition of the present embodiment preferably further contains a photopolymerization initiator as the component (F). The photosensitive resin composition of the present embodiment tends to further improve the resolution of vias by containing (F) a photopolymerization initiator.
(F) As the photopolymerization initiator, one type may be used alone, or two or more types may be used in combination.

The photopolymerization initiator (F) is not particularly limited as long as it can photopolymerize an ethylenically unsaturated group, and can be appropriately selected from commonly used photopolymerization initiators.
(F) Examples of the photopolymerization initiator include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and the like. 1,1-Dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] Acetphenones such as -2-morpholino-1-propanone, N, N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2- Anthracinones such as aminoanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone , Methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis (diethylamino) benzophenone, Michler's ketone, 4-benzoyl-4'-methyldiphenylsulfide and other benzophenones; 9-phenylaclydin, 1,7-bis Acridines such as (9,9'-acrydinyl) heptane; Acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 1,2-octanedione-1- [4- (phenylthio) phenyl]- 2- (O-benzoyloxime), 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] etanone 1- (O-acetyloxime), 1-phenyl-1,2 Examples thereof include oxime esters such as −propandione-2- [O- (ethoxycarbonyl) oxime].

Among these, acetophenones and thioxanthones are preferable, and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone and 2,4-diethylthioxanthone are more preferable. Acetophenones have the advantage that they are less likely to volatilize and are less likely to be generated as outgas, and thioxanthones have the advantage that they can be photocured in the visible light region. Further, it is more preferable to use acetophenone and thioxanthone in combination, and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone and 2,4-diethylthioxanthone are used in combination. Is particularly preferable.

When the photosensitive resin composition of the present embodiment contains (F) a photopolymerization initiator, the content of the (F) photopolymerization initiator is not particularly limited, but is based on the total amount of resin components of the photosensitive resin composition. It is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, still more preferably 0.2 to 5% by mass, and particularly preferably 0.3 to 2% by mass. (F) When the content of the photopolymerization initiator is at least the above lower limit value, it tends to be possible to reduce the elution of the exposed portion during development, and when it is at least the above upper limit value, the heat resistance is improved. There is a tendency.

<(G) Inorganic filler>
The photosensitive resin composition of the present embodiment preferably further contains an inorganic filler as the component (G). The photosensitive resin composition of the present embodiment tends to obtain lower dielectric loss tangent and excellent low thermal expansion property by containing (G) an inorganic filler.
As the (G) inorganic filler, one type may be used alone, or two or more types may be used in combination.

Examples of the (G) inorganic filler include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TIO ₂ ), titanium oxide (Ta ₂ O ₅ ), zirconia (ZrO ₂ ), and silicon nitride (Si). ₃ N ₄ ), barium titanate (BaO · TiO ₂ ), barium carbonate (BaCO ₃ ), magnesium carbonate (MgCO ₃ ), aluminum hydroxide (Al (OH) ₃ ), magnesium hydroxide (Mg (OH) ₂ ) , Lead titanate (PbO · TiO ₂ ), lead zirconate titanate (PZT), lead lanthanum nitrite (PLZT), gallium oxide (Ga ₂ O ₃ ), spinel (MgO · Al ₂ O ₃ ), mullite _{(3Al 2 O 3 · 2SiO 2} ), cordierite _{(2MgO · 2Al 2 O 3 /} 5SiO 2), talc _{(3MgO · 4SiO 2 · H 2} O), aluminum titanate _{(TiO 2 · Al 2 O 3} ), Zirconia containing _{itria (Y 2} O ₃ · ZrO ₂ ), barium silicate (BaO · 8SiO ₂ ), boron nitride (BN), calcium carbonate (CaCO ₃ ), barium sulfate (BaSO ₄ ), calcium sulfate (CaSO ₄ ), Examples thereof include zinc oxide (ZnO), magnesium titanate (MgO · TiO ₂ ), hydrotalcite, mica, calcined kaolin, carbon (C) and the like. Among these, silica is preferable from the viewpoint of heat resistance, low thermal expansion property and dielectric property.

The inorganic filler (G) may be surface-treated with a coupling agent such as a silane coupling agent from the viewpoint of improving the dispersibility in the photosensitive resin composition. Examples of the silane coupling agent include aminosilane-based coupling agents, epoxysilane-based coupling agents, phenylsilane-based coupling agents, alkylsilane-based coupling agents, alkenylsilane-based coupling agents, and alkynylsilane-based coupling agents. Haloalkylsilane-based coupling agent, siloxane-based coupling agent, hydrosilane-based coupling agent, silazane-based coupling agent, alkoxysilane-based coupling agent, chlorosilane-based coupling agent, (meth) acrylic silane-based coupling agent, isocyanurate Examples thereof include a silane-based coupling agent, a ureidosilane-based coupling agent, a mercaptosilane-based coupling agent, a sulfide silane-based coupling agent, and an isocyanate-silane-based coupling agent.

As the (G) inorganic filler, only the inorganic filler surface-treated with one kind of coupling agent may be used, or two or more kinds of inorganic fillers surface-treated with different coupling agents may be used in combination. ..
When a coupling agent is used, the addition method may be a so-called integral blend treatment method in which the (G) inorganic filler is added to the photosensitive resin composition and then the coupling agent is added. , The method may be a method in which the coupling agent is surface-treated in advance on the (G) inorganic filler before compounding by a dry method or a wet method.

The average particle size of the inorganic filler (G) is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, still more preferably 0.1 to 1 μm, and particularly preferably 0.1 to 1 μm, from the viewpoint of via resolution. It is 0.15 to 0.7 μm.
As the (G) inorganic filler, two or more kinds of inorganic fillers having different average particle sizes may be used in combination.
(G) The average particle size of the inorganic filler means the volume average particle size, and uses a submicron particle analyzer (manufactured by Beckman Coulter Co., Ltd., trade name: N5) in accordance with the international standard ISO13321. The particles dispersed in the solvent with a refractive index of 1.38 can be measured and determined as the particle size corresponding to the integrated value of 50% (volume basis) in the particle size distribution.

When the photosensitive resin composition of the present embodiment contains the (G) inorganic filler, the content thereof is not particularly limited, but is preferably 10 to 70% by mass based on the total solid content of the photosensitive resin composition. , More preferably 30 to 65% by mass, still more preferably 40 to 60% by mass, and particularly preferably 45 to 55% by mass. When the content of the (G) inorganic filler is at least the above lower limit value, a lower dielectric loss tangent and a coefficient of thermal expansion tend to be obtained, and when it is at least the above upper limit value, better adhesion to plated copper is obtained. And the resolution of vias tends to be obtained.

<(H) Epoxy resin curing agent>
When the photosensitive resin composition of the present embodiment contains (C) epoxy resin, it may further contain (H) epoxy resin curing agent. By containing the (H) epoxy resin curing agent, the photosensitive resin composition of the present embodiment tends to further improve the heat resistance, dielectric properties, etc. of the obtained cured product.
As the epoxy resin curing agent (H), one type may be used alone, or two or more types may be used in combination.

Examples of the epoxy resin curing agent include guanamines such as acetguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulphon, dicyandiamide, urea, urea derivative, melamine, and polybasic hydrazide. Phenols such as; these organolates and / or epoxy adducts; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xysilyl Triazine derivatives such as —S-triazine; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolak, and triazine ring-containing phenol novolac resin can be mentioned.
Among these, polyphenols are preferable.
When the photosensitive resin composition of the present embodiment contains the (H) epoxy resin curing agent, the content thereof is not particularly limited, but from the viewpoint of further improving heat resistance and dielectric properties, the photosensitive resin composition Based on the total amount of the resin component of the above, it is preferably 0.01 to 5% by mass, more preferably 0.05 to 1% by mass, and further preferably 0.1 to 0.5% by mass.

<(I) Additive>
The photosensitive resin composition of the present embodiment contains, if necessary, pigments such as phthalocyanine blue, phthalocyanine green, iodin green, diazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black; imidazole and derivatives thereof. Curing accelerators such as tertiary amines, organic phosphines, phosphonium salts, quaternary ammonium salts, polybasic acid anhydrides; adhesion aids such as melamine; sensitizers such as 4,4'-bisdiethylaminobenzophenone A foam stabilizer such as a silicone compound; various known and commonly used additives such as a polymerization inhibitor, a thickener, and a flame retardant may be contained.
The content of these (I) additives may be appropriately adjusted according to the respective purposes, but for each, it is preferably 0.01 to 5% by mass based on the total amount of the resin component of the photosensitive resin composition. It is more preferably 0.05 to 3% by mass, still more preferably 0.1 to 1% by mass.

<Diluent>
A diluent can be used in the photosensitive resin composition of the present embodiment, if necessary. As the diluent, for example, an organic solvent or the like can be used. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether and dipropylene. Glycol ethers such as glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, propylene glycol monoethyl ether acetate, butyl cellosolve acetate, carbitol acetate; octane, decane And other aliphatic hydrocarbons; petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha can be mentioned. As the diluent, one type may be used alone, or two or more types may be used in combination.

The content of the diluent is such that the concentration of the total solid content in the photosensitive resin composition is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, and further preferably 50 to 70% by mass. It may be selected as appropriate. By adjusting the amount of the diluent used within the above range, the coatability of the photosensitive resin composition is improved, and a higher-definition pattern can be formed.

The photosensitive resin composition of the present embodiment can be obtained by kneading and mixing each component with a roll mill, a bead mill or the like.
Here, the photosensitive resin composition of the present embodiment may be used as a liquid or as a film.
When used as a liquid, the method for applying the photosensitive resin composition of the present embodiment is not particularly limited, and examples thereof include a printing method, a spin coating method, a spray coating method, a jet dispensing method, an inkjet method, and a dip coating method. Various coating methods can be mentioned. Among these, the printing method and the spin coating method are preferable from the viewpoint of forming the photosensitive layer more easily.
When used as a film, for example, it can be used in the form of a photosensitive resin film described later. In this case, a photosensitive layer having a desired thickness is formed by laminating it on a carrier film using a laminator or the like. can do. It is preferable to use it in the form of a film because the manufacturing efficiency of the multilayer printed wiring board is high.

[Photosensitive resin film]
The photosensitive resin film of the present embodiment is made of the photosensitive resin composition of the present embodiment, and is suitable for use in forming a photosensitive layer to be an interlayer insulating layer later.
The photosensitive resin film of the present embodiment may be provided on a carrier film.
The thickness (thickness after drying) of the photosensitive resin film (photosensitive layer) is not particularly limited, but is preferably 1 to 100 μm, more preferably 3 to 50 μm, and further, from the viewpoint of reducing the thickness of the multilayer printed wiring board. It is preferably 5 to 40 μm.

The photosensitive resin film of the present embodiment is, for example, a known coating of the photosensitive resin composition of the present embodiment on a carrier film, such as a comma coater, a bar coater, a kiss coater, a roll coater, a gravure coater, and a die coater. It can be formed by coating and drying with an apparatus.
Examples of the carrier film 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.

Further, in the photosensitive resin film of the present embodiment, a protective film may be provided on the surface opposite to the surface in contact with the carrier film. As the protective film, for example, a polymer film such as polyethylene or polypropylene can be used. Further, a polymer film similar to the carrier film described above may be used, or a different polymer film may be used.

For drying the coating film formed by applying the photosensitive resin composition, a dryer using hot air drying, far infrared rays, or near infrared rays can be used. The drying temperature is preferably 60 to 150 ° C, more preferably 70 to 120 ° C, and even more preferably 80 to 100 ° 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 content of the residual diluent in the photosensitive resin film after drying is preferably 3% by mass or less, more preferably 2% by mass or less, from the viewpoint of avoiding diffusion of the diluent in the manufacturing process of the multilayer printed wiring board. , More preferably 1% by mass or less.

The photosensitive resin film of the present embodiment is excellent in resolution of vias, adhesiveness to plated copper, and insulation reliability, and is therefore suitable as an interlayer insulating layer of a multilayer printed wiring board. That is, the present invention also provides a photosensitive resin film for an interlayer insulating layer made of the photosensitive resin composition of the present embodiment.

[Multilayer printed wiring board and its manufacturing method]
The multilayer printed wiring board of the present embodiment contains an interlayer insulating layer formed by using the photosensitive resin composition of the present embodiment or the photosensitive resin film of the present embodiment. The method for producing the multilayer printed wiring board of the present embodiment is not particularly limited as long as it has a step of forming an interlayer insulating layer using the photosensitive resin composition of the present embodiment. It can be easily manufactured by the method for manufacturing a multilayer printed wiring board of the embodiment.

A method of manufacturing a multilayer printed wiring board using the photosensitive resin film of the present embodiment will be described with reference to FIG. 1 as appropriate.
The multilayer printed wiring board 100A can be manufactured, for example, by a manufacturing method including the following steps (1) to (4).
Step (1): A step of laminating the photosensitive resin film of the present embodiment on one side or both sides of a circuit board [hereinafter, referred to as a laminating step (1)].
Step (2): A step of forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in the step (1) [hereinafter, referred to as a photovia forming step (2)].
Step (3): A step of roughening the via and the interlayer insulating layer [hereinafter, referred to as a roughening treatment step (3)].
Step (4): A step of forming a circuit pattern on the interlayer insulating layer [hereinafter, referred to as a circuit pattern forming step (4)].

(Laminating process (1))
In the laminating step (1), the photosensitive resin film (photosensitive resin film for interlayer insulating layer) of the present embodiment is laminated on one side or both sides of a circuit board (board 101 having a circuit pattern 102) using a vacuum laminator. It is a process. Examples of the vacuum laminator include a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressurized laminator manufactured by Meiki Co., Ltd., a roll-type dry coater manufactured by Hitachi, Ltd., and a vacuum laminator manufactured by Hitachi Kasei Electronics Co., Ltd. And so on.

When a protective film is provided on the photosensitive resin film, after peeling or removing the protective film, the photosensitive resin film is pressed and laminated on the circuit board while being pressurized and heated so as to be in contact with the circuit board. can do.
In the laminate, for example, the photosensitive resin film and the circuit board are preheated as necessary, and then the crimping temperature is 70 to 130 ° C., the crimping pressure is 0.1 to 1.0 MPa, and the air pressure is 20 mmHg (26.7 hPa) or less. It can be carried out under reduced pressure, but is not particularly limited to this condition. Further, the laminating method may be a batch method or a continuous method using a roll.
Finally, the photosensitive resin film laminated on the circuit board is cooled to around room temperature to form the interlayer insulating layer 103. When the photosensitive resin film has a carrier film, the carrier film may be peeled off here, or may be peeled off after exposure as described later.

(Photovia forming step (2))
In the photovia forming step (2), at least a part of the photosensitive resin film laminated on the circuit board is exposed and then developed. By exposure, the portion irradiated with the active light is photocured to form a pattern. The exposure method is not particularly limited, and for example, a method of irradiating an active light image in an image shape through a negative or positive mask pattern called artwork (mask exposure method) may be adopted, or LDI (Laser Direct Imaging) may be adopted. A method of irradiating an active ray in an image shape by a direct drawing exposure method such as an exposure method or a DLP (Digital Light Processing) exposure method may be adopted.
As the light source of the active light, a known light source can be used. Specifically, as the light source, a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, a xenon lamp, a gas laser such as an argon laser; a solid laser such as a YAG laser; an ultraviolet ray or a visible light such as a semiconductor laser is effectively emitted. Things and so on. The exposure amount is appropriately selected depending on the light source used, the thickness of the photosensitive layer, and the like. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, when the thickness of the photosensitive layer is 1 to 100 μm, it is usually 10 to 1,000 mJ / cm. ^{About 2} is preferable, and 15 to 500 mJ / cm ² is more preferable.

In development, the uncured portion of the photosensitive layer is removed from the substrate, so that an interlayer insulating layer made of a photocured cured product is formed on the substrate.
If a carrier film is present on the photosensitive layer, the carrier film is removed, and then the unexposed portion is removed (developed). There are two types of development methods, wet development and dry development, and either of them may be adopted. However, wet development is widely used, and wet development can also be adopted in this embodiment.
In the case of wet development, development is performed by a known development method using a developer corresponding to the photosensitive resin composition. Examples of the developing method include methods using a dip method, a battle method, a spray method, brushing, slapping, scraping, rocking immersion, and the like. Among these, the spray method is preferable from the viewpoint of improving the resolution, and the high pressure spray method is more preferable among the spray methods. The development may be carried out by one kind of method, but may be carried out by combining two or more kinds of methods.
The composition of the developing solution is appropriately selected according to the composition of the photosensitive resin composition. For example, an alkaline aqueous solution, an aqueous developer, an organic solvent developer and the like can be mentioned, and among these, an alkaline aqueous solution is preferable.

In the photovia forming step (2), after exposure and development, post-UV cure with an exposure amount of ^{about 0.2 to 10 J / cm 2} (preferably 0.5 to 5 J / cm ^{2) and about 60 to 250 ° C.} The interlayer insulating layer may be further cured by performing post-thermal curing at a temperature of (preferably 120 to 200 ° C.) as necessary, and it is preferable to do so.
As described above, the interlayer insulating layer having the via 104 is formed. The shape of the via is not particularly limited, and the cross-sectional shape includes, for example, a quadrangle, an inverted trapezoid (the upper side is longer than the lower side), and the shape seen from the front (the direction in which the bottom of the via can be seen) is circular. , Squares and the like. In the formation of vias by the photolithography method in the present embodiment, vias having an inverted trapezoidal cross-sectional shape (the upper side is longer than the lower side) can be formed, and in this case, the plating copper has a high tendency to attach to the via wall surface. Is preferable.

The size (diameter) of the vias formed by this step can be less than 40 μm, further can be 35 μm or less or 30 μm or less, and the diameter is smaller than the size of the vias produced by laser processing. can do. The lower limit of the size (diameter) of the via formed by this step is not particularly limited, but may be 15 μm or more, or 20 μm or more.
However, the size (diameter) of the via formed by this step is not limited to less than 40 μm, and may be arbitrarily selected in the range of, for example, 15 to 300 μm.

(Roughening process (3))
In the roughening treatment step (3), the surfaces of the via and the interlayer insulating layer are roughened with a roughening liquid. If smear is generated in the photovia forming step (2), the smear may be removed by the roughening solution. The roughening treatment and the removal of smear can be performed at the same time.
Examples of the roughening solution include chromium / sulfuric acid roughening solution, alkaline permanganate roughening solution (for example, sodium permanganate roughening solution, etc.), sodium fluoride / chromium / sulfuric acid roughening solution, and the like. ..
By the roughening treatment, uneven anchors are formed on the surfaces of the via and the interlayer insulating layer.

(Circuit pattern forming step (4))
The circuit pattern forming step (4) is a step of forming a circuit pattern on the interlayer insulating layer after the roughening treatment step (3).
The formation of the circuit pattern is preferably carried out by a semi-additive process from the viewpoint of forming fine wiring. The semi-additive process forms the circuit pattern and conducts the vias.
In the semi-additive process, first, after the roughening treatment step (3), the via bottom, the via wall surface, and the entire surface of the interlayer insulating layer are subjected to electroless copper plating treatment after using a palladium catalyst or the like to perform the seed layer 105. To form. The seed layer is for forming a feeding layer for performing electrolytic copper plating, and is preferably formed with 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 be possible to suppress a decrease in connection reliability during electrolytic copper plating, and if it is 2.0 μm or less, the seed layer between wirings is flash-etched. It is not necessary to increase the amount of etching at the time of etching, and there is a tendency that damage to the wiring during etching can be suppressed.

The electroless copper plating treatment is carried out by depositing metallic copper on the surfaces of vias and the interlayer insulating layer by the reaction of copper ions and a reducing agent.
A known method may be applied to the electroless plating treatment method and the electrolytic plating treatment method, and the method is not particularly limited.
Commercially available products can be used as the electroless copper plating solution. Examples of commercially available products include "MSK-DK" manufactured by Atotech Japan Co., Ltd. and "Sulcup (registered trademark) PEA series" manufactured by C. Uyemura & Co., Ltd. And so on.

After performing the above electroless copper plating treatment, a dry film resist is thermocompression bonded onto the electroless copper plating with a roll laminator. The thickness of the dry film resist must be higher than the wiring height after electrolytic copper plating, and from this viewpoint, a dry film resist having a thickness of 5 to 30 μm is preferable. As the dry film resist, the "Fotech" series manufactured by Hitachi Kasei Co., Ltd. or the like is used.
After thermocompression bonding of the dry film resist, for example, the dry film resist is exposed through a mask on which a desired wiring pattern is drawn. The exposure can be carried out with the same apparatus and light source as those that can be used for forming vias on the photosensitive resin film. After the exposure, the dry film resist is developed using an alkaline aqueous solution to remove the unexposed portion to form the resist pattern 106. After that, if necessary, the work of removing the development residue of the dry film resist may be performed using plasma or the like.
After development, copper circuit layer 107 is formed and via-filled by electrolytic copper plating.

After electrolytic copper plating, the dry film resist is peeled off using an alkaline aqueous solution or an amine-based stripping agent. After peeling off the dry film resist, the seed layer between the wirings 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, if necessary, remove palladium or the like adhering to the portion between the wirings. The removal of palladium can preferably be carried out using an acidic solution such as nitric acid or hydrochloric acid.

After the dry film resist is peeled off or after the flash etching step, a post-baking treatment is preferably performed. The post-baking process sufficiently heat-cures the unreacted thermosetting components, thereby improving insulation reliability, curing properties and adhesion to plated copper. The thermosetting conditions vary depending on the type of resin composition and the like, but it is preferable that the curing temperature is 150 to 240 ° C. and the curing time is 15 to 100 minutes. The post-baking process completes the manufacturing process of the multilayer printed wiring board by a single photovia method, and this process is repeated to manufacture the substrate according to the number of interlayer insulating layers required. Then, a solder resist layer 108 is preferably formed on the outermost layer.

The method for manufacturing a multilayer printed wiring board for forming vias using the photosensitive resin composition of the present embodiment has been described above, but the photosensitive resin composition of the present embodiment is excellent in pattern resolution. Therefore, for example, it is also suitable for forming a cavity for incorporating a chip, a passive element, or the like. The cavity is preferably formed by, for example, in the above description of the multilayer printed wiring board, the drawing pattern when the photosensitive resin film is exposed to the pattern is formed so that a desired cavity can be formed. Can be done.

[Semiconductor package]
The present invention also provides a semiconductor package in which a semiconductor element is mounted on a multilayer printed wiring board of the present embodiment. The semiconductor package of the present embodiment can be manufactured by mounting a semiconductor element such as a semiconductor chip or a memory at a predetermined position on the multilayer printed wiring board of the present embodiment and sealing the semiconductor element with a sealing resin or the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The characteristics of the photosensitive resin compositions obtained in each example were evaluated by the methods shown below.

[Acid value measurement method]
The acid value was calculated from the amount of 0.1 mol / L potassium hydroxide aqueous solution required to neutralize the resin obtained in each synthetic example. At this time, the point at which the phenolphthalein added as an indicator changed from colorless to pink was defined as the neutralization point.

[1. Solubility (1% by mass sodium carbonate aqueous solution)]
The solubility was measured by immersing the photosensitive resin film obtained in each example in a 1% by mass sodium carbonate aqueous solution at 30 ± 2 ° C. and measuring the time required for the photosensitive resin film to completely dissolve as the dissolution time. , Evaluated based on the following criteria.
<Evaluation criteria>
A: Dissolution time is less than 20 seconds B: Dissolution time is 20 seconds or more and less than 40 seconds C: Dissolution time is 40 seconds or more

[2. Developer dissolution contrast]
Prepare a 1.0 mm thick copper-clad laminated substrate (manufactured by Hitachi Kasei Co., Ltd., trade name "MCL-E-67"), and prepare a protective film from the carrier film and photosensitive resin film with protective film manufactured in each example. The photosensitive resin film that has been peeled off and exposed is placed on the above copper-clad laminated substrate using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name "MVLP-500") under predetermined laminating conditions ( A laminate having a photosensitive layer was obtained by laminating at a crimping pressure: 0.4 MPa, a press hot plate temperature: 80 ° C., a vacuuming time: 25 seconds, a laminating press time: 25 seconds, and an air pressure: 4 kPa or less).
Next, a mask on which a via pattern having an opening diameter of a predetermined size is formed (opening mask diameter size: 5, 8, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, and 100 μmφ). Using an i-line exposure apparatus (manufactured by Ushio Co., Ltd., product number "UX-2240SM-XJ-01"), exposure was performed at an exposure amount such that the number of step tablet stages (ST) was 7.
Thereafter, 1 using mass% sodium carbonate aqueous solution, 30 ° C. time shortest developing time equivalent to four times the (unexposed area of the photosensitive layer is the shortest time to be removed) in, the 1.765 × 10 5 ^Pa The unexposed portion was melt-developed by spray-developing with pressure.
Next, using an ultraviolet exposure device, the ^{photosensitive resin is exposed at an exposure amount of 2,000 mJ / cm 2} and then heated at 160 ° C. for 1 hour to form a photosensitive resin having a via pattern of a predetermined size on a copper-clad laminated substrate. A test piece having a cured product of the composition was prepared.
The above test piece was observed using a metallurgical microscope, and among the via patterns whose openings were confirmed, the top and bottom of the smallest via pattern were measured, and the ratio of the lengths of the top and bottom (top / bottom) was determined. It was calculated and evaluated based on the following criteria.
<Evaluation criteria>
A: less than 2.0 B: more than 2.0, less than 2.5 C: more than 2.5

[3. Evaluation of dielectric loss tangent]
Two photosensitive resin films from which the protective film has been peeled off are pasted together, and while holding the carrier films on both sides, 400 mJ / cm ^{2 (365 nm) with a flat exposure machine and 2 J / cm 2} (365 nm) with a UV conveyor type exposure machine. Irradiated. This was heat-treated at 170 ° C. for 1 hour at 170 ° C. for 1 hour in a warm air circulation type dryer, and cut into a size of 7 cm × 10 cm to prepare an evaluation sample.
The obtained evaluation sample was dried at 105 ° C. for 10 minutes in a warm air circulation type dryer, and the dielectric loss tangent was measured by the split post dielectric resonator method (SPDR method).

Synthesis example 1
(Synthesis of Acid-Modified Vinyl Group-Containing Epoxy Resin A-1)
500 parts by mass of bisphenol F type epoxy resin (manufactured by DIC Co., Ltd., trade name "EXA-7376"), 72 parts by mass of acrylic acid, 0.5 parts by mass of hydroquinone, and 150 parts by mass of carbitol acetate were charged into a reaction vessel at 90 ° C. The mixture was dissolved by heating and stirring. Next, the obtained solution was cooled to 60 ° C., 2 parts by mass of benzyltrimethylammonium chloride was charged, and the mixture was heated to 100 ° C. and reacted until the acid value of the solution reached 1 mgKOH / g. 230 parts by mass of tetrahydrophthalic anhydride and 85 parts by mass of carbitol acetate were added to the solution after the reaction, and the mixture was heated to 80 ° C. and reacted for 6 hours. Then, the mixture was cooled to room temperature and diluted with carbitol acetate so that the solid content concentration became 60% by mass to obtain an acid-modified vinyl group-containing epoxy resin A-1.

Synthesis example 2
(Synthesis of Acid-Modified Vinyl Group-Containing Epoxy Resin A-2)
250 parts by mass of dicyclopentadiene type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name "XD-1000", epoxy resin having a structure represented by the above general formula (A-2)), 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone and 120 parts by mass of carbitol acetate were placed in a reaction vessel, and the mixture was dissolved by heating to 90 ° C. and stirring. Next, the obtained solution was cooled to 60 ° C., 2 parts by mass of triphenylphosphine was added, and the mixture was heated to 100 ° C. and reacted until the acid value of the solution reached 1 mgKOH / g. To the solution after the reaction, 98 parts by mass of tetrahydrophthalic anhydride and 850 parts by mass of carbitol acetate were added, and the mixture was heated to 80 ° C. and reacted for 6 hours. Then, the mixture was cooled to room temperature, and the solvent was distilled off so that the solid content concentration became 65% by mass to obtain an acid-modified vinyl group-containing epoxy resin A-2.

[Preparation of photosensitive resin composition]
Examples 1-3, Reference Example 1, Comparative Example 1
(1) Production of Photosensitive Resin Composition The composition is blended according to the compounding composition shown in Table 1 (the unit of the numerical value in the table is a mass part, and in the case of a solution, it is a solid content equivalent amount). Kneaded with a roll mill. Then, methyl ethyl ketone was added so that the solid content concentration became 65% by mass, and a photosensitive resin composition was obtained.
(2) Production of Photosensitive Resin Film A polyethylene terephthalate film with a thickness of 16 μm (manufactured by Teijin Co., Ltd., trade name “G2-16”) is used as a carrier film, and the photosensitive resin composition prepared in each example is placed on the carrier film. The material was applied so that the film thickness after drying was 25 μm, and dried at 75 ° C. for 30 minutes using a hot air convection dryer to form a photosensitive resin film (photosensitive layer). Subsequently, a polyethylene film (manufactured by Tamapoli Co., Ltd., trade name "NF-15") is attached as a protective film on the surface of the photosensitive resin film (photosensitive layer) opposite to the side in contact with the carrier film. Together, a photosensitive resin film was prepared by laminating a carrier film and a protective film.

Each evaluation was carried out according to the above method using the produced photosensitive resin film. The results are shown in Table 1.

The components used in Table 1 are as follows.
[(A) Photopolymerizable compound]
-Acid-modified vinyl group-containing epoxy resin A-1: Acid-modified vinyl group-containing epoxy resin A-1 prepared in Synthesis Example 1.
-Acid-modified vinyl group-containing epoxy resin A-2: Acid-modified vinyl group-containing epoxy resin A-2 prepared in Synthesis Example 2.

[(B) Maleimide compound]
-Biphenyl aralkyl type maleimide resin (manufactured by Nippon Kayaku Co., Ltd., trade name "MIR-3000-70MT", maleimide group equivalent 275 g / eq)

[(C) Epoxy resin]
-Bisphenol F type epoxy resin (bisphenol type epoxy resin, epoxy equivalent 184 g / eq)
-Naftor novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name "NC-7000-L", epoxy equivalent 234 g / eq)
-Biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name "NC-3000-L", epoxy equivalent 273 g / eq)

[(D) Crosslinking agent]
-Dipentaerythritol hexaacrylate-tricyclodecanedimethanol diacrylate-bisallyl nadiimide compound 1: Compound represented by the following general formula (D-4)

-Bisallyl nadiimide compound 2: A compound represented by the following general formula (D-5).

[(E) Elastomer]
-Polyester elastomer (manufactured by Hitachi Kasei Co., Ltd., product name "SP1108")
-Epoxy polybutadiene (manufactured by Daicel Chemical Co., Ltd., trade name "PB3600")
-Maleic anhydride-modified polybutadiene (manufactured by Clay Valley, trade name "Ricon (registered trademark) 130MA8", number of maleic anhydride-modified groups: 2, 1,4-trans form +1,4-cis form: 72%)

[(F) Photopolymerization Initiator]
-Photopolymerization initiator 1: 2-methyl- [4- (methylthio) phenyl] morpholino-1-propanone (acetophenones)
-Photopolymerization initiator 2: 2,4-diethylthioxanthone (thioxanthones)

[(G) Inorganic filler]
-Silica 1: Fused spherical silica with an average particle size of 0.5 μm (coupling agent treated product)
-Silica 2: Fused spherical silica with an average particle size of 0.18 μm (coupling agent treated product)

[(H) Epoxy resin curing agent]
-Triazine ring-containing phenol novolac resin (manufactured by DIC Corporation, trade name "LA7052")

[(I) Additive]
・ 4,4'-Bisdiethylaminobenzophenone ・ 1,3,5-triazine-2,4,6-triamine ・ Silicone-based defoaming agent ・ Pigment

From Table 1, the photosensitive resin compositions of Examples 1 to 3 of this embodiment have a significantly reduced dielectric loss tangent as compared with the photosensitive resin composition of Comparative Example 1 which does not contain the component (B). I understand. The photosensitive resin compositions of Examples 1 to 3 and Reference Example 1 of this embodiment both have a low dielectric loss tangent, and among these, the photosensitive resin compositions of Examples 1 to 3 containing the component (B). It can be seen that the photosensitive resin composition can achieve a significantly low dielectric loss tangent.

100A Multi-layer printed wiring board 101 Board 102 Circuit pattern 103 Interlayer insulation layer 104 Via (via hole)
105 Seed layer 106 Resist pattern 107 Copper circuit layer 108 Solder resist layer

Claims (18)

(A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, and (B) a maleimide compound having an N-substituted maleimide group.
A photosensitive resin composition containing. The photosensitive resin composition according to claim 1, wherein the (A) photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent contains an alicyclic structure represented by the following general formula (A-1). Stuff.

(Wherein, R ^A1 represents an alkyl group having 1 to 12 carbon atoms, where optionally substituted on .m ¹ in said alicyclic structure is an integer of 0 to 6. * Are the other structures It is the binding site of.) The photosensitive resin composition according to claim 1 or 2, wherein the photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent (A) has an acid value of 20 to 200 mgKOH / g. (B) The photosensitive resin composition according to any one of claims 1 to 3, wherein the maleimide compound having an N-substituted maleimide group is an aromatic maleimide compound having two or more N-substituted maleimide groups. The content ratio [(A) / (B)] of the (A) photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent to the (B) maleimide compound having an N-substituted maleimide group is The photosensitive resin composition according to any one of claims 1 to 4, which is 1 to 10 on a mass basis. The photosensitive resin composition according to any one of claims 1 to 5, further comprising (C) an epoxy resin. The photosensitive resin composition according to claim 6, which contains a bisphenol type epoxy resin and an aralkyl type epoxy resin as the (C) epoxy resin. The photosensitive resin composition according to any one of claims 1 to 7, further comprising (D) a cross-linking agent having two or more ethylenically unsaturated groups and no acidic substituent. The photosensitive resin composition according to claim 8, wherein the (D) cross-linking agent contains (D1) a cross-linking agent having two or more (meth) acryloyl groups and no acidic substituent. The photosensitive resin composition according to claim 8 or 9, wherein the (D) cross-linking agent contains (D2) a cross-linking agent having two or more allyl groups and no acidic substituent. The photosensitive resin composition according to any one of claims 1 to 10, further comprising (E) an elastomer and, as the (E) elastomer, an elastomer having an ethylenically unsaturated group and an acidic substituent. Stuff. The photosensitive resin composition according to any one of claims 1 to 11, further comprising (F) a photopolymerization initiator. The photosensitive resin composition according to any one of claims 1 to 12, further comprising (G) an inorganic filler in an amount of 10 to 70% by mass based on the total solid content of the photosensitive resin composition. The photosensitive resin composition according to any one of claims 1 to 13, which is used for forming one or more kinds selected from the group consisting of a photovia and an interlayer insulating layer. A photosensitive resin film comprising the photosensitive resin composition according to any one of claims 1 to 14. A multilayer printed wiring board comprising an interlayer insulating layer formed by using the photosensitive resin composition according to any one of claims 1 to 14 or the photosensitive resin film according to claim 15. A semiconductor package in which a semiconductor element is mounted on the multilayer printed wiring board according to claim 16. A method for manufacturing a multilayer printed wiring board, which comprises the following steps (1) to (4).
Step (1): A step of laminating the photosensitive resin film according to claim 15 on one side or both sides of a circuit board.
Step (2): A step of forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in the step (1).
Step (3): A step of roughening the via and the interlayer insulating layer.
Step (4): A step of forming a circuit pattern on the interlayer insulating layer.