Photosensitive resin composition, photosensitive resin film, multilayer printed wiring board and semiconductor package, and method for manufacturing multilayer printed wiring board

Abstract

The present application provides a photosensitive resin composition, which is a photosensitive resin composition containing (A) a photopolymerizable compound having an ethylenically unsaturated group, (X) an organic particle, and (B) a photopolymerization initiator, the (A) photopolymerizable compound having an ethylenically unsaturated group containing (A1) a photopolymerizable compound having an ethylenically unsaturated group, an acidic substituent, and an alicyclic skeleton. In addition, a photosensitive resin film and an interlayer insulating layer photosensitive resin film containing the photosensitive resin composition are provided. Furthermore, a multilayer printed wiring board and a semiconductor package are provided. Further, a method for manufacturing the multilayer printed wiring board is provided.

Description

Technical Field

[0001] This disclosure relates to a photosensitive resin composition, a photosensitive resin film, a multilayer printed circuit board and a semiconductor package, and a method for manufacturing a multilayer printed circuit board. Background Technology

[0002] In recent years, the miniaturization and high performance of electronic devices have driven the increase in the density of multilayer printed circuit boards (PCBs) through increased circuit layers and finer wiring. In particular, the density of semiconductor packaging substrates such as BGAs (Ball Grid Arrays) and CSPs (Chip Scale Packages) for mounting semiconductor chips has increased significantly. Besides the finer wiring, this requires thinner insulating films and further miniaturization of vias (also known as "conductive vias") for interlayer connections. Furthermore, the thinning of insulating films in PCBs also necessitates excellent interlayer electrical insulation reliability, especially after moisture absorption [HAST (High Accelerated Stress Test) resistance].

[0003] As a method for manufacturing printed circuit boards, one example is a multilayer printed circuit board manufacturing method that utilizes a build-up method (for example, see Patent Document 1) to form a multilayer printed circuit board by sequentially stacking interlayer insulating layers and conductor circuit layers. In multilayer printed circuit boards, with the miniaturization of circuits, the semi-additive method of forming circuits by plating has become mainstream.

[0004] In conventional semi-additive methods, for example, (1) a thermosetting resin film is laminated onto the conductor circuit, and the thermosetting resin film is cured by heating to form an "interlayer insulating layer". (2) Next, through-holes for interlayer connection are formed by laser processing, and desmearing and roughening treatment is performed by alkaline permanganate treatment, etc. (3) Then, electroless copper plating is performed on the substrate, and after patterning with a resist, copper is electroplated to form a copper circuit layer. (4) Next, resist is stripped and electroless flash etching is performed to form a copper circuit.

[0005] As mentioned above, laser processing has become the mainstream method for forming through-holes in the interlayer insulation layer formed by curing thermosetting resin films. However, the miniaturization of through-holes using laser irradiation with a laser processing machine has reached its limit. Furthermore, in the formation of through-holes using a laser processing machine, each through-hole needs to be formed individually. When multiple through-holes are required due to high density, the formation of through-holes takes a long time, resulting in poor manufacturing efficiency.

[0006] In this situation, as a method to form multiple through holes at the same time, a method is proposed to form multiple small-diameter through holes at the same time using a photosensitive resin composition and photolithography. The photosensitive resin composition contains (A) an acid-modified vinyl-containing epoxy resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) an inorganic filler material, and (E) a silane compound, wherein the content of the inorganic filler material (D) is 10 to 80% by mass (for example, see Patent Document 2).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 7-304931

[0010] Patent Document 2: Japanese Patent Application Publication No. 2017-116652 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] Patent Document 2 addresses the issue of reducing the adhesion strength to copper plating caused by using a photosensitive resin composition instead of a conventional thermosetting resin composition as the interlayer insulating layer or surface protective layer. Furthermore, it addresses via resolution and the adhesion to the silicon substrate and chip components, and resolves these issues. However, in addition to further miniaturization of the wiring, the insulating film has been thinned and the vias for interlayer connections have been reduced in diameter. Therefore, the requirements for improving the adhesion strength to copper plating and the reliability of electrical insulation are greater. In these aspects, the photosensitive resin composition in Patent Document 2 has room for further improvement.

[0013] Furthermore, conventional photosensitive resin compositions cannot be said to possess sufficient crack resistance to withstand reflow soldering.

[0014] Therefore, the present disclosure aims to provide a photosensitive resin composition with excellent via resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance; a photosensitive resin composition for via formation; and a photosensitive resin composition for interlayer insulating layers. Furthermore, it aims to provide a photosensitive resin film comprising the above-mentioned photosensitive resin compositions, a photosensitive resin film for interlayer insulating layers, a multilayer printed circuit board, and a semiconductor package, as well as a method for manufacturing the above-mentioned multilayer printed circuit board.

[0015] Methods for solving problems

[0016] The inventors have conducted repeated and active research and found that the above-mentioned objectives can be achieved through this disclosure. This disclosure includes the following [1] to

[19] .

[0017] [1] A photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylene unsaturated group, (X) organic particles and (B) a photopolymerization initiator,

[0018] The photopolymerizable compound (A) having an ethylene unsaturated group includes (A1) a photopolymerizable compound having an ethylene unsaturated group, an acidic substituent, and an alicyclic skeleton.

[0019] [2] The photosensitive resin composition as described in [1] above, wherein the component (organic compound) constituting the (X) organic particle contains at least one selected from the group consisting of polyethylene, polybutadiene, polystyrene, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene copolymer, styrene-divinylbenzene copolymer, (meth)acrylate copolymer, silicone rubber, polyvinyl alcohol, epoxy resin, polyester, polyamide, polyimide, polyamide-imide, polyurethane, polyphenylene ether and melamine resin.

[0020] [3] The photosensitive resin composition as described in [1] or [2] above, wherein the organic particles (X) contain core-shell particles.

[0021] [4] As described in [3] above, the combination (core / shell) of the components constituting the core and the components constituting the shell of the core-shell particles is styrene-butadiene copolymer / (meth)acrylate copolymer, (meth)acrylate copolymer / epoxy resin, epoxy resin / silicone rubber, acrylonitrile-butadiene copolymer / (meth)acrylate copolymer, polyethylene / (meth)acrylate copolymer, polybutadiene / (meth)acrylate copolymer, polyester / (meth)acrylate copolymer.

[0022] [5] The photosensitive resin composition as described in any one of [1] to [4] above, wherein the photopolymerizable compound having an ethylene unsaturated group (A) further comprises at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylene unsaturated group, (Aii) a difunctional vinyl monomer having two polymerizable ethylene unsaturated groups and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylene unsaturated groups.

[0023] [6] In any of the above-mentioned photosensitive resin compositions [1] to [5], in the above-mentioned (A1) photopolymerizable compound having an ethylene unsaturated group, an acidic substituent and an alicyclic skeleton, the alicyclic skeleton is an alicyclic skeleton with 5 to 20 cyclic carbon atoms.

[0024] [7] In any of the above-mentioned photosensitive resin compositions [1] to [6], in the above-mentioned (A1) photopolymerizable compound having an ethylene unsaturated group, an acidic substituent and an alicyclic skeleton, the alicyclic skeleton comprises two or more rings.

[0025] [8] The photosensitive resin composition as described in any one of [1] to [7] above further contains (C) a thermosetting resin.

[0026] [9] The photosensitive resin composition as described in any one of [1] to [8] above further contains (D) an elastomer.

[0027]

[10] The photosensitive resin composition as described in [9] above, wherein the elastomer (D) comprises at least one selected from the group consisting of styrene elastomers, olefin elastomers, polyester elastomers, urethane elastomers, polyamide elastomers, acrylic elastomers and silicone elastomers.

[0028]

[11] The photosensitive resin composition as described in any one of [1] to

[10] above further contains (F) an inorganic filler.

[0029]

[12] A photosensitive resin composition for forming a light-permeable hole, comprising any one of the photosensitive resin compositions described in [1] to

[11] above.

[0030]

[13] A photosensitive resin composition for an interlayer insulating layer, comprising any one of the photosensitive resin compositions described in [1] to

[11] above.

[0031]

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

[11] above.

[0032]

[15] A photosensitive resin film for interlayer insulation, comprising the photosensitive resin composition described in any one of [1] to

[11] above.

[0033]

[16] A multilayer printed wiring board comprising an interlayer insulating layer, wherein the interlayer insulating layer is formed using any one of the photosensitive resin compositions described in [1] to

[11] .

[0034]

[17] A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin film described above

[14] .

[0035]

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

[16] or

[17] above, and semiconductor elements.

[0036]

[19] A method for manufacturing a multilayer printed circuit board includes the following (1) to (4).

[0037] (1): The photosensitive resin film described above

[14] is laminated onto one or both sides of the circuit board.

[0038] (2): Expose and develop the photosensitive resin film laminated in (1) above to form an interlayer insulating layer with through holes.

[0039] (3): Roughen the above-mentioned through holes and the above-mentioned interlayer insulation layer.

[0040] (4): A circuit pattern is formed on the above-mentioned interlayer insulating layer.

[0041] Invention Effects

[0042] According to this disclosure, a photosensitive resin composition, a photosensitive resin composition for forming through-holes, and a photosensitive resin composition for interlayer insulating layers can be provided, exhibiting excellent through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance. Furthermore, a photosensitive resin film comprising the above-mentioned photosensitive resin composition and a photosensitive resin film for interlayer insulating layers can be provided, as well as a multilayer printed circuit board and a semiconductor package containing an interlayer insulating layer formed using the above-mentioned photosensitive resin composition or the above-mentioned photosensitive resin film.

[0043] Furthermore, a method for efficiently manufacturing a multilayer printed circuit board (PCB) with high-resolution through-holes, strong adhesion between the interlayer insulation layer and the copper plating, and excellent electrical insulation reliability is provided. The PCB obtained by the manufacturing method of this disclosure has through-holes with a diameter smaller than those formed by laser processing. Attached Figure Description

[0044] [ Figure 1 [Illustration 1] is a schematic diagram illustrating one method of manufacturing the multilayer printed circuit board according to this embodiment. Detailed Implementation

[0045] Within the numerical ranges described in this specification, the upper or lower limit of the numerical range can be replaced with the values ​​shown in the embodiments. Furthermore, the lower and upper limits of the numerical ranges can be arbitrarily combined with the lower or upper limits of other numerical ranges.

[0046] Furthermore, in this specification, when there are multiple substances equivalent to each component in the photosensitive resin composition, the content of each component refers to the total content of the multiple substances present in the photosensitive resin composition unless otherwise specified.

[0047] In this specification, "number of carbon atoms for ring formation" refers to the number of carbon atoms required to form a ring, excluding the number of carbon atoms from substituents present in the ring. For example, the number of carbon atoms for ring formation in both the cyclohexane skeleton and the methylcyclohexane skeleton is 6.

[0048] The expression "(meth)acrylic acid XX" refers to one or both of acrylic acid XX and its corresponding methacrylic acid XX. Additionally, "(meth)acryloyl" refers to one or both of acryloyl and methacryloyl groups.

[0049] In this specification, for example, the description "greater than or equal to 10" refers to a value of 10 and above, and the same applies to cases where the value is different. Similarly, the description "less than or equal to 10" refers to a value of 10 and below, and the same applies to cases where the value is different.

[0050] In this specification, "interlayer insulating layer" refers to a layer located between two conductive layers and used to insulate the conductive layers. Examples of "interlayer insulating layers" in this specification include cured photosensitive resin films. It should be noted that in this specification, "layer" also includes layers with missing portions, layers with through-holes, or patterns.

[0051] Furthermore, any combination of the items described in this specification is also included in this disclosure.

[0052] [Photosensitive resin composition, photosensitive resin composition for forming light-permeable holes, and photosensitive resin composition for interlayer insulating layers]

[0053] One embodiment of this disclosure (hereinafter, sometimes simply referred to as this embodiment) relates to a photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylene unsaturated group, (X) organic particles, and (B) a photopolymerization initiator, wherein the aforementioned (A) photopolymerizable compound having an ethylene unsaturated group comprises (A1) a photopolymerizable compound simultaneously having an ethylene unsaturated group, an acidic substituent, and an alicyclic skeleton.

[0054] It should be noted that in this specification, the above-mentioned components are sometimes referred to as component (A), component (X), component (B), component (A1), etc., and other components are sometimes abbreviated in the same way. In this specification, "resin component" refers to the above-mentioned components (A), (X), and (B), etc., and also includes other components that may be included as needed (e.g., components (C), (D), (E), and (H), etc.), but does not include inorganic compounds such as (F) inorganic fillers and (G) pigments, which may be included as needed as described later. In addition, "solid component" refers to non-volatile components other than volatile substances such as water and solvents contained in the photosensitive resin composition, and indicates components that do not volatilize and remain when the resin composition is dried. It also includes components that are liquid, syrupy, or waxy at room temperature around 25°C.

[0055] The photosensitive resin composition of this embodiment is suitable for via formation (also known as photolithography) using photolithography, therefore, this disclosure also provides a photosensitive resin composition for photolithography. Furthermore, the photosensitive resin composition of this embodiment exhibits excellent via resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance, and is useful as an interlayer insulating layer in multilayer printed circuit boards; therefore, this disclosure also provides a photosensitive resin composition for interlayer insulating layers. In this specification, the term "photosensitive resin composition" includes both a photosensitive resin composition for photolithography and a photosensitive resin composition for interlayer insulating layers.

[0056] It should be noted that the photosensitive resin composition of this embodiment is useful as a negative photosensitive resin composition.

[0057] The following details the components that may be contained in a photosensitive resin composition.

[0058] <(A) Photopolymerizable compounds with vinyl unsaturated groups>

[0059] From the viewpoint of adhesion strength to copper plating, the photosensitive resin composition of this embodiment includes a photopolymerizable compound having an vinyl unsaturated group as component (A). Examples of vinyl unsaturated groups in component (A) include vinyl, allyl, propargyl, butenyl, ethynyl, phenylethynyl, maleimide, nadicimide, and (meth)acryloyl. (Methacryl)acryloyl is preferred as the vinyl unsaturated group.

[0060] In this embodiment, component (A) comprises "(A1) a photopolymerizable compound having an ethylene unsaturated group, an acidic substituent, and an alicyclic skeleton," as described later. By including component (A1) in component (A), a photosensitive resin composition with excellent through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance is achieved.

[0061] The following is a detailed description of component (A1).

[0062] ((A1) Photopolymerizable compounds that simultaneously possess ethylene unsaturated groups, acidic substituents, and alicyclic skeletons)

[0063] As an ethylene unsaturated group in component (A1), groups identical to those described above can be listed. Preferably, this ethylene unsaturated group is selected from at least one group chosen from the group consisting of vinyl, allyl, propargyl, butenyl, ethynyl, phenylethynyl, maleimide, nadicimide, and (meth)acryloyl, more preferably vinyl, allyl, or (meth)acryloyl, and even more preferably (meth)acryloyl.

[0064] The acidic substituents present in component (A1) are preferably selected from at least one of the group consisting of carboxyl, sulfonic acid, phenolic hydroxyl, etc., and more preferably carboxyl.

[0065] From the viewpoints of through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance, the alicyclic skeleton of component (A1) is preferably an alicyclic skeleton with 5 to 20 carbon atoms, more preferably an alicyclic skeleton with 5 to 18 carbon atoms, even more preferably an alicyclic skeleton with 6 to 18 carbon atoms, particularly preferably an alicyclic skeleton with 8 to 14 carbon atoms, and most preferably an alicyclic skeleton with 8 to 12 carbon atoms.

[0066] Furthermore, from the viewpoints of through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance, the aforementioned alicyclic skeleton preferably contains two or more rings, more preferably two to four rings, and even more preferably three rings. Examples of alicyclic skeletons with one ring include cyclohexane and cyclohexene skeletons. Examples of alicyclic skeletons with two or more rings include norbornene, decahydronaphthalene, bicycloundecane, and saturated dicyclopentadiene skeletons.

[0067] From the viewpoints of through-hole resolution, adhesion strength to copper plating, electrical insulation reliability and crack resistance, the saturated dicyclopentadiene skeleton is preferred as the above-mentioned alicyclic skeleton, and the alicyclic skeleton (saturated dicyclopentadiene skeleton) represented by the following general formula (a) is more preferred.

[0068] [Chemistry 1]

[0069]

[0070] (In general formula (a), R) A1 Alkyl groups representing 1 to 12 carbon atoms can be substituted at any position in the above-described alicyclic skeleton. 1Integers from 0 to 6. * indicates the junction with other structures.

[0071] In general formula (a), R is used as A1 Examples of alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferably, the alkyl group has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably methyl.

[0072] m 1 It is an integer from 0 to 6, preferably an integer from 0 to 2, and more preferably 0.

[0073] In m 1 When R is an integer from 2 to 6, multiple R A1 They can be the same or different. Furthermore, multiple R... A1 Substitution can be performed on the same carbon atom or on different carbon atoms, within the possible range.

[0074] *For bonding sites with other structures, any carbon atom on the alicyclic framework can be used for bonding, preferably the carbon atom represented by 1 or 2 in the following general formula (a') and any one of the carbon atoms represented by 3 to 5.

[0075] [Chemistry 2]

[0076]

[0077] (In the general formula (a'), R) A1 m 1 The asterisks and * are the same as in general formula (a).

[0078] Examples of components (A1) include "(A1-1) acid-modified epoxy derivatives containing vinyl unsaturated groups and alicyclic skeletons" and "(A1-2) acid-modified phenolic varnish or cresol varnish resins containing vinyl unsaturated groups and alicyclic skeletons".

[0079] The aforementioned "(A1-1) acid-modified epoxy derivatives containing ethylene unsaturated groups and alicyclic skeletons" is obtained by reacting a compound [hereinafter sometimes referred to as component (A')] obtained by modifying an epoxy resin containing an alicyclic skeleton with an organic acid containing ethylene unsaturated groups (a2) with a polybasic acid anhydride containing saturated or unsaturated groups;

[0080] The above-mentioned "(A1-2) acid-modified phenolic varnish or cresol varnish resin containing vinyl unsaturated groups and alicyclic skeleton" is prepared by reacting modified phenolic varnish type epoxy resin with (a2) an organic acid containing vinyl unsaturated groups and (a4) a polybasic acid anhydride containing an alicyclic skeleton and containing saturated or unsaturated groups. The above-mentioned modified phenolic varnish type epoxy resin is prepared by addition polymerization of phenolic varnish resin or cresol varnish resin with at least one selected from the group consisting of ethylene oxide and propylene oxide.

[0081] As for the (A1) component, from the viewpoints of being able to undergo alkaline development and having excellent through-hole resolution, adhesion strength to copper plating, electrical insulation reliability and crack resistance, the above-mentioned "(A1-1) acid-modified epoxy derivative containing ethylene unsaturated groups and alicyclic skeleton" is preferred.

[0082] First, the raw materials that can be used in the manufacture of “(A1-1) acid-modified epoxy derivatives containing ethylene unsaturated groups and alicyclic skeletons” are described in detail.

[0083] -(a1) Epoxy resins containing alicyclic skeletons-

[0084] As the epoxy resin with an alicyclic skeleton mentioned above (a1), an epoxy resin having two or more epoxy groups is preferred. Epoxy resins can be classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0085] In this embodiment, an epoxy resin having at least an alicyclic backbone is used as the epoxy resin. The alicyclic backbone can be described in the same manner as the alicyclic backbone of component (A1) described above, and the preferred manner is also the same.

[0086] As the epoxy resin containing an alicyclic skeleton (a1), the epoxy resin represented by the following general formula (a1-1) is preferred. In addition, epoxy resins having structural units represented by the following general formula (a1-2) are also preferred.

[0087] [Chemistry 3]

[0088]

[0089] (In general formula (a1-1), R) A1 Alkyl groups representing 1 to 12 carbon atoms can be substituted at any position in the above-described alicyclic skeleton. R A2 Indicates alkyl groups with 1 to 12 carbon atoms. m 1 m is an integer from 0 to 6. 2 (Integers from 0 to 3. n is from 0 to 10.)

[0090] [Chemistry 4]

[0091]

[0092] (In general formula (a1-2), R) A1 Alkyl groups representing 1 to 12 carbon atoms can be substituted at any position in the above-described alicyclic skeleton. 1 (Integers from 0 to 6.)

[0093] In general formulas (a1-1) and (a1-2), R A1 R in general formula (a) A1 The same applies to both, and the preferred selection method is also the same.

[0094] R in the general formula (a1-1) A2 Examples of alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferably, the alkyl group has 1 to 6 carbon atoms; more preferably, it has 1 to 3 carbon atoms; and methyl is even more preferred.

[0095] m in general formulas (a1-1) and (a1-2) 1 With m in general formula (a) 1 The same applies to both, and the preferred selection method is also the same.

[0096] m in general formula (a1-1) 2 It is an integer from 0 to 3, preferably 0 or 1, and more preferably 0.

[0097] In general formula (a1-1), n ​​represents the number of repetitions of the structural unit within the parentheses, which is 0 to 10. Typically, the epoxy resin is a mixture of substances with different numbers of repetitions of the structural units within the parentheses; therefore, in this case, n is represented by the average value of the mixture. Preferably, n is 2 to 10.

[0098] As for (a1) epoxy resins containing an alicyclic skeleton, commercially available products can be used. Examples of commercially available products include: XD-1000 (manufactured by Nippon Kayaku Co., Ltd., trade name), EPICLON HP-7200L, EPICLON HP-7200, EPICLON HP-7200HH, EPICLON HP-7200HHH (manufactured by DIC Co., Ltd., trade name, "EPICLON" is a registered trademark), etc.

[0099] As (a1) epoxy resin, epoxy resins other than those with an alicyclic skeleton (hereinafter, sometimes referred to as other epoxy resins) may also be used. Other epoxy resins include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and other bisphenol-based epoxy resins; bisphenol A phenolic varnish type epoxy resin, bisphenol F phenolic varnish type epoxy resin, and other bisphenol-based phenolic varnish type epoxy resins; phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, biphenyl phenolic varnish type epoxy resin, and other phenolic varnish type epoxy resins other than the above-mentioned bisphenol-based phenolic varnish type epoxy resins; phenol aralkyl type epoxy resin; biphenyl aralkyl type epoxy resin; stilbene type epoxy resin; naphthalene type epoxy resin, naphthol phenolic varnish type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, naphthylene ether type epoxy resin, and other naphthalene-containing skeleton type epoxy resins; biphenyl type epoxy resin; xylene-type epoxy resin; dihydroanthracene type epoxy resin; aliphatic chain epoxy resin; rubber modified epoxy resin, etc.

[0100] -(a2) Organic acids containing ethylene unsaturated groups-

[0101] There are no particular limitations on the organic acid containing an ethylene unsaturated group in (a2) above, but monocarboxylic acids containing an ethylene unsaturated group are preferred. The ethylene unsaturated group is as described in the explanation of the ethylene unsaturated group in component (A1) above.

[0102] Examples of monocarboxylic acids containing an ethylene unsaturated group include: acrylic acid; acrylic acid dimers, methacrylic acid, β-furfurylic acid, β-styrylic acid, cinnamic acid, crotonic acid, α-cyanocinonic acid, and other acrylic acid derivatives; half-ester compounds that are the reaction products of hydroxyl-containing acrylates and diacid anhydrides; and half-ester compounds that are the reaction products of monoglycidyl ethers or monoglycidyl esters containing ethylene unsaturated groups and diacid anhydrides. Among these, acrylic acid is preferred.

[0103] (a2) Components may be used alone or in combination with two or more.

[0104] The aforementioned half-ester compounds can be obtained, for example, by reacting a hydroxyl-containing acrylate, a monoglycidyl ether containing an vinyl unsaturated group, or a monoglycidyl ether containing an vinyl unsaturated group with a dicarboxylic anhydride in an equimolar ratio.

[0105] Examples of hydroxyl-containing acrylates, vinyl unsaturated monoglycidyl ethers, and vinyl unsaturated monoglycidyl esters used in the synthesis of the above-mentioned half-ester compound, which is an example of component (a2), include: hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, glycidyl acrylate, glycidyl methacrylate, etc.

[0106] The diacid anhydrides used in the synthesis of the aforementioned half-ester compounds may contain either saturated or unsaturated groups. Examples of diacid anhydrides include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride.

[0107] While there are no particular limitations, in the reaction between component (a1) and component (a2) described above, it is preferable that component (a2) reacts at a ratio of 0.6 to 1.05 equivalents relative to the epoxy group of component (a1), or alternatively at a ratio of 0.8 to 1.0 equivalents. By reacting at such a ratio, there is a tendency for improved photopolymerization, i.e., increased photosensitivity, and improved aperture resolution.

[0108] The above-mentioned component (a1) and component (a2) can react in a state where they are dissolved in an organic solvent.

[0109] Examples of organic solvents include: ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

[0110] Furthermore, in order to promote the reaction between the above-mentioned component (a1) and component (a2), a catalyst is preferably used. Examples of such catalysts include: amine catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and benzyltrimethylammonium iodide; and phosphine catalysts such as triphenylphosphine. Among these, phosphine catalysts are preferred, and triphenylphosphine is more preferred.

[0111] The amount of catalyst used is preferably 0.01 to 10 parts by mass relative to the total of 100 parts by mass of component (a1) and component (a2), more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass. If the above amounts are used, there is a tendency to promote the reaction between component (a1) and component (a2).

[0112] Furthermore, to prevent polymerization during the reaction, polymerization inhibitors are preferred. Examples of polymerization inhibitors include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol.

[0113] When using a polymerization inhibitor, from the viewpoint of improving the storage stability of the composition, the amount of polymerization inhibitor used is preferably 0.01 to 1 part by mass relative to the total 100 parts by mass of the above-mentioned components (a1) and (a2), more preferably 0.02 to 0.8 parts by mass, and even more preferably 0.05 to 0.5 parts by mass.

[0114] From a productivity point of view, the reaction temperature of the above-mentioned component (a1) and component (a2) is preferably 60 to 150°C, more preferably 70 to 120°C, and even more preferably 80 to 110°C.

[0115] Thus, it is speculated that component (A'), formed by reacting component (a1) with component (a2), has a hydroxyl group formed by the ring-opening addition reaction of the epoxy group of component (a1) with the carboxyl group of component (a2).

[0116] -(a3) Polyacid Anhydrides-

[0117] As for component (a3) ​​above, it may contain either saturated or unsaturated groups. Examples of components (a3) ​​include: succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride, etc. Among these, tetrahydrophthalic anhydride is preferred from the viewpoint of pore resolution.

[0118] Hypothesis: By further reacting the (A') component obtained above with the (a3) ​​component containing saturated or unsaturated groups, a half-esterification of the hydroxyl groups of the (A') component (including the hydroxyl groups originally present in the (a1) component) and the anhydride groups of the (a3) ​​component is formed, resulting in an epoxy derivative modified with (A1-1) acid containing ethylene unsaturated groups and an alicyclic skeleton.

[0119] In the reaction of component (A') and component (a3), for example, by reacting component (a3) ​​by 0.1 to 1.0 equivalents relative to 1 equivalent of hydroxyl group in component (A'), the acid value of the epoxy derivative containing ethylene unsaturated group and alicyclic skeleton modified by (A1-1) acid can be adjusted.

[0120] (A1-1) The acid value of the acid-modified epoxy derivative containing vinyl unsaturated groups and an alicyclic skeleton is preferably 20–150 mg KOH / g, more preferably 30–120 mg KOH / g, and even more preferably 40–100 mg KOH / g. If the acid value is greater than or equal to 20 mg KOH / g, the photosensitive resin composition tends to have excellent solubility in dilute alkaline solutions; if it is less than or equal to 150 mg KOH / g, the electrical properties of the cured film tend to be improved.

[0121] From a productivity point of view, the reaction temperature of component (A') and component (a3) ​​is preferably 50 to 150°C, more preferably 60 to 120°C, and even more preferably 70 to 100°C.

[0122] Therefore, there are no particular limitations on the photopolymerizable compounds (A1) that simultaneously possess ethylene unsaturated groups, acidic substituents, and alicyclic skeletons, but they are preferably represented by the following general formula (A-1).

[0123] [Chemistry 5]

[0124]

[0125] (In general formula (A-1), R) A1 Alkyl groups representing 1 to 12 carbon atoms can be substituted at any position in the above-described alicyclic skeleton. R A2 R represents an alkyl group having 1 to 12 carbon atoms. A3 It is an organogroup having an ethylene unsaturated group, an organogroup having an ethylene unsaturated group and an acidic substituent, or a glycidyl group, with at least one R A3 It is an organic group with an ethylene unsaturated group and an acidic substituent. 1 m is an integer from 0 to 6. 2 (Integers from 0 to 3. n is from 0 to 10.)

[0126] In the above general formula (A-1), R A1 R A2 m 1 m 2 The values ​​of n are the same as those in the above general formula (a1-1), and the preferred values ​​are also the same.

[0127] R A3As defined above, it is defined as: a site formed by the reaction of the glycidyl group in the above general formula (a1-1) with components (a2) and (a3) ​​above, while also considering the case where a portion of the glycidyl group does not react. That is, as R A3 The option "organic group having an ethylene unsaturated group" refers to a group derived from component (a2) above, and "organic group having an ethylene unsaturated group and an acidic substituent" refers to a group derived from components (a2) and (a3) ​​above. If components (a2) and (a3) ​​above react with all glycidyl groups in the above general formula (a1-1), then R A3 It becomes "an organic group having an ethylene unsaturated group and an acidic substituent", but only the part that reacts with component (a2) above becomes "an organic group having an ethylene unsaturated group", and the part that does not react with either component (a2) or component (a3) ​​above becomes "glycidyl group".

[0128] Next, the raw materials that can be used in the manufacture of the above-mentioned "(A1-2) acid-modified phenolic varnish or cresol varnish resin containing ethylene unsaturated groups and alicyclic skeleton" will be briefly described.

[0129] One of the raw materials is a modified phenolic varnish-type epoxy resin obtained by addition polymerization of phenolic varnish resin or cresol varnish resin with at least one selected from the group consisting of ethylene oxide and propylene oxide. Preferably, a catalyst is used in this addition polymerization. Examples of catalysts include metallic sodium, sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium phenolate, and various Lewis acids.

[0130] There are no particular limitations on the weight-average molecular weight of phenolic varnish resin and cresol varnish resin, but they are preferably 500 to 30,000, more preferably 1,000 to 10,000. It should be noted that, in this specification, the weight-average molecular weight (and number-average molecular weight) are values ​​obtained by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent and converted to standard polystyrene; more specifically, they are values ​​determined according to the methods described below.

[0131] There are no particular restrictions on the reaction temperature; it can be carried out in the range of 60–230°C.

[0132] Regarding the above-mentioned additive polymerization, any well-known methods can be used or applied, and there are no restrictions on the methods described above.

[0133] Modified phenolic varnish-type epoxy resin can be obtained through the above addition polymerization.

[0134] As for "(a2) organic acid containing ethylene unsaturated groups" which reacts with the modified phenolic varnish-type epoxy resin obtained above, it can be described in the same way as the description of "(a2) organic acid containing ethylene unsaturated groups" above.

[0135] Furthermore, the alicyclic skeleton contained in "(a4) a polycyclic anhydride containing an alicyclic skeleton and saturated or unsaturated groups" that reacts with the modified phenolic varnish-type epoxy resin obtained above is preferably an alicyclic skeleton with 5 to 20 ring-forming carbon atoms, more preferably an alicyclic skeleton with 5 to 15 ring-forming carbon atoms, even more preferably an alicyclic skeleton with 5 to 10 ring-forming carbon atoms, and particularly preferably an alicyclic skeleton with 5 to 8 ring-forming carbon atoms. This alicyclic skeleton can be a single ring or contain two or more rings, but is preferably a single ring. As this alicyclic skeleton, a cyclohexane skeleton, a cyclohexene skeleton, etc., is preferred, and a cyclohexene skeleton is more preferably a cyclohexene skeleton.

[0136] Examples of "(a4) polybasic acid anhydrides containing an alicyclic skeleton and saturated or unsaturated groups" include tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and ethylhexahydrophthalic anhydride. Among these, tetrahydrophthalic anhydride and phthalic anhydride are preferred, and tetrahydrophthalic anhydride is more preferred.

[0137] There are no particular restrictions on the conditions for reacting the modified phenolic varnish-type epoxy resin with (a2) an organic acid containing an ethylene unsaturated group and (a4) a polycyclic anhydride containing an alicyclic skeleton and a saturated or unsaturated group. For example, methods such as reacting with component (a2) at 20–100°C in the presence of a catalyst, and then reacting with component (a4) at 20–100°C, can be listed.

[0138] ((A1) Molecular weight of photopolymerizable compounds that simultaneously possess ethylene unsaturated groups, acidic substituents, and alicyclic skeletons)

[0139] The weight-average molecular weight (Mw) of component (A1) is preferably 1,000 to 30,000, more preferably 2,000 to 25,000, and even more preferably 3,000 to 18,000. Within this range, the adhesion strength to copper plating, heat resistance, and electrical insulation reliability are improved. Particularly preferred is the weight-average molecular weight (Mw) of the acid-modified epoxy derivative containing ethylene unsaturated groups and an alicyclic skeleton described above (A1-1). Here, the weight-average molecular weight (and number-average molecular weight) are values ​​determined by gel permeation chromatography (GPC) (manufactured by Tosoh Corporation) using a standard curve of standard polystyrene, and more specifically, values ​​determined according to the methods described below.

[0140] <Methods for determining weight-average molecular weight and number-average molecular weight>

[0141] Weight-average molecular weight and number-average molecular weight were determined using the GPC measuring apparatus and conditions described below. The values ​​converted from the standard curve of standard polystyrene were used as weight-average molecular weight or number-average molecular weight. In addition, in the preparation of the standard curve, five sample groups ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation) were used as standard polystyrene.

[0142] (GPC measuring device)

[0143] GPC Unit: High-speed GPC unit "HCL-8320GPC", detector is differential refractive index detector or UV detector, manufactured by Tosoh Corporation.

[0144] Column: Column TSKgel SuperMultipore HZ-H (column length: 15cm, column inner diameter: 4.6mm), manufactured by Tosoh Corporation

[0145] (Measurement conditions)

[0146] Solvent: Tetrahydrofuran (THF)

[0147] Measurement temperature: 40℃

[0148] Flow rate: 0.35 mL / min

[0149] Sample concentration: 10 mg / THF 5 mL

[0150] Injection volume: 20μL

[0151] ((A2-1) Acid-modified epoxy derivatives containing vinyl unsaturated groups without alicyclic skeleton)

[0152] As a photopolymerizable compound having an ethylene unsaturated group (A), it can also be further comprising "(A2-1) an acid-modified epoxy derivative containing an ethylene unsaturated group without an alicyclic skeleton." The aforementioned "(A2-1) an acid-modified epoxy derivative containing an ethylene unsaturated group without an alicyclic skeleton" is obtained by reacting a compound obtained by modifying an epoxy resin (a21) (which does not contain an alicyclic skeleton) with an organic acid containing an ethylene unsaturated group (a22) with a polybasic acid anhydride containing a saturated or unsaturated group (a23).

[0153] As for the epoxy resin mentioned above (a21), there are no particular limitations as long as it does not contain an alicyclic skeleton. Examples include glycidyl ether type epoxy resin, glycidyl amine type epoxy resin, and glycidyl ester type epoxy resin. Among these, glycidyl ether type epoxy resin is preferred.

[0154] In addition, the epoxy resins mentioned above (a21) can also be classified into various epoxy resins according to the different main skeletons. Among the various types of epoxy resins mentioned above, they can be further classified as follows. Specifically, epoxy resins can be classified as follows: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and other bisphenol-based epoxy resins; bisphenol A phenolic varnish type epoxy resin, bisphenol F phenolic varnish type epoxy resin, and other bisphenol-based phenolic varnish type epoxy resins; phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, biphenyl phenolic varnish type epoxy resin, and other phenolic varnish type epoxy resins other than the aforementioned bisphenol-based phenolic varnish type epoxy resins; phenol aralkyl type epoxy resin; stilbene type epoxy resin; naphthalene type epoxy resin, naphthol phenolic varnish type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, naphthylene ether type epoxy resin, and other naphthalene-containing skeleton type epoxy resins; biphenyl type epoxy resin; biphenyl aralkyl type epoxy resin; xylene type epoxy resin; dihydroanthracene type epoxy resin; aliphatic chain epoxy resin; rubber modified epoxy resin, etc. Among these, bisphenol-based phenolic varnish epoxy resin is preferred, and bisphenol F phenolic varnish epoxy resin is even more preferred.

[0155] As for the organic acid containing an ethylene unsaturated group (a22) and the polybasic acid anhydride containing a saturated or unsaturated group (a23) mentioned above, they can be described in the same manner as the descriptions of the organic acid containing an ethylene unsaturated group (a2) and the polybasic acid anhydride containing a saturated or unsaturated group (a3) ​​mentioned above, and the preferred methods are also the same.

[0156] In addition, as a method for reacting the compound obtained by modifying the above-mentioned component (a21) with the above-mentioned component (a22) with the above-mentioned component (a23), the method of reacting the compound obtained by modifying the above-mentioned component (a1) with the above-mentioned component (a2) with the above-mentioned component (a3) ​​can be referred to.

[0157] As an acid-modified epoxy derivative containing an ethylene unsaturated group without an alicyclic skeleton (A2-1), commercially available products can also be used. Examples of commercially available products include: CCR-1218H, CCR-1159H, CCR-1222H, PCR-1050, TCR-1335H, ZAR-1035, ZAR-2001H, UXE-3024, ZFR-1185, ZCR-1569H, ZXR-1807, ZCR-6000, ZCR-8000 (all manufactured by Nippon Kayaku Co., Ltd., trade names), UE-9000, UE-EXP-2810PM, UE-EXP-3045 (all manufactured by DIC Co., Ltd., trade names), etc.

[0158] When component (A) contains both component (A1) (or component (A1-1)) and component (A2-1), from the viewpoint of balancing characteristics such as through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance, the content ratio of component (A1) (or component (A1-1)) to component (A2-1) [(A1) or (A1-1) / (A2-1)] by mass is preferably 20 / 80 to 99 / 1, more preferably 50 / 50 to 99 / 1, further preferably 60 / 40 to 99 / 1, particularly preferably 60 / 40 to 85 / 15, and most preferably 65 / 35 to 80 / 20.

[0159] ((A2-2)Styrene-maleic acid resin)

[0160] As a photopolymerizable compound having an ethylene unsaturated group (A), it can also be used in combination with styrene-maleic anhydride copolymers modified with hydroxyethyl methacrylate, etc., as "(A2-2) styrene-maleic acid resin". This (A2-2) component does not contain an alicyclic skeleton. The (A2-2) component can be used alone or in combination with two or more.

[0161] ((A2-3) Epoxy polyurethane resin)

[0162] Furthermore, as a photopolymerizable compound having an ethylene unsaturated group (A), "(A2-3) epoxy polyurethane resin" can also be used. The aforementioned "(A2-3) epoxy polyurethane resin" is obtained by reacting a compound modified with an organic acid containing an ethylene unsaturated group (a22) with an isocyanate compound. Examples of compounds obtained by modifying the aforementioned epoxy resin (a21) with an organic acid containing an ethylene unsaturated group (a22) include components such as those in component (A') of a compound obtained by modifying an epoxy resin containing an alicyclic skeleton (a1) with an organic acid containing an ethylene unsaturated group (a2).

[0163] This (A2-3) component does not contain an alicyclic skeleton. Component (A2-3) can be used alone or in combination with two or more.

[0164] (Ingredients other than (A) mentioned above)

[0165] As for the photopolymerizable compound (A) having an vinyl unsaturated group, from the viewpoint of improving chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas, it is preferable that the photopolymerizable compound (A) further comprises at least one selected from the group consisting of a monofunctional vinyl monomer having one polymerizable vinyl unsaturated group (Ai), a difunctional vinyl monomer having two polymerizable vinyl unsaturated groups (Aii), and a polyfunctional vinyl monomer having at least three polymerizable vinyl unsaturated groups (Aiii), and more preferably, the compound comprising the aforementioned component (Aiii). As for components (Ai) to (Aiii), components with a molecular weight less than or equal to 1,000 are preferred. In this embodiment, components (Ai) to (Aiii) do not include component (A1).

[0166] ((Ai) monofunctional vinyl monomer)

[0167] Examples of monofunctional vinyl monomers having a polymerizable vinyl unsaturated group include (meth)acrylic acid and alkyl (meth)acrylates. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and hydroxyethyl (meth)acrylate. The (Ai) component may be used alone or in combination with two or more components.

[0168] ((Aii) difunctional vinyl monomer)

[0169] Examples of difunctional vinyl monomers having two polymerizable vinyl unsaturated groups include polyethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloyloxypolyethoxypolypropoxyphenyl)propane, and bisphenol A diglycidyl ether di(meth)acrylate. The (Aii) component can be used alone or in combination with two or more components.

[0170] ((Aiii) Multifunctional vinyl monomers)

[0171] Examples of polyfunctional vinyl monomers having at least three polymerizable vinyl unsaturated groups include: trimethylolpropane tri(meth)acrylate and other (meth)acrylate compounds having a backbone derived from trimethylolpropane; tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate and other (meth)acrylate compounds having a backbone derived from tetramethylolmethane; pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate and other (meth)acrylate compounds having a backbone derived from pentaerythritol; dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other (meth)acrylate compounds having a backbone derived from dipentaerythritol; di(trimethylolpropane) tetra(meth)acrylate and other (meth)acrylate compounds having a backbone derived from di(trimethylolpropane); and (meth)acrylate compounds having a backbone derived from diglycerol. Among these, from the viewpoint of improving chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas, (meth)acrylate compounds having a backbone derived from dipentaerythritol are preferred, and dipentaerythritol penta(meth)acrylate is more preferred. Component (Aiii) may be used alone or in combination with two or more.

[0172] Here, the aforementioned "(meth)acrylate compounds having a skeleton derived from XXX" (where XXX is the name of the compound) refers to the esterification of XXX with (meth)acrylic acid, which also includes compounds modified with alkylene oxides.

[0173] (A) Content of component

[0174] (A) The content of the component is not particularly limited. From the viewpoint of heat resistance, electrical properties and chemical resistance, based on the total amount of solid components in the photosensitive resin composition, it is preferably less than or equal to 60% by mass, more preferably 0.1 to 55% by mass, further preferably 1 to 50% by mass, particularly preferably 2 to 40% by mass, most preferably 3 to 37% by mass, and may be 5 to 37% by mass, 15 to 37% by mass, or 20 to 37% by mass.

[0175] As for component (A), there are no particular limitations, but from the viewpoint of photosensitivity, it is preferable to use the above-described component (A1) and component (Aiii) together. In this case, the content ratio of the above-described component (A1) to the above-described component (Aiii) [(A1) / (Aiii)] (mass ratio) is preferably 2 to 20, more preferably 2 to 15, even more preferably 2.5 to 10, and particularly preferably 3 to 6.

[0176] Furthermore, from the viewpoints of through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance, the content ratio of component (A1) relative to the total amount of component (A) is preferably 20 to 95% by mass, more preferably 40 to 95% by mass, even more preferably 65 to 95% by mass, and particularly preferably 80 to 95% by mass.

[0177] <(X) Organic Particles>

[0178] The photosensitive resin composition of this embodiment, by containing (X) organic particles, can maintain a high through-hole resolution while improving adhesion to copper plating, electrical insulation reliability, and crack resistance. In particular, the electrical insulation reliability after moisture absorption (HAST resistance) is improved.

[0179] (X) The organic particles are present in particulate form in the photosensitive resin composition. The ratio (r2 / r1) of the major diameter r2 of the organic particles to the minor diameter r1 is preferably less than or equal to 1.4, more preferably less than or equal to 1.2, and even more preferably less than or equal to 1.1. This ratio (r2 / r1) is the average value of any 10 particles.

[0180] It should be noted that the minor axis r1 and major axis r2 of the organic particles (X) are values ​​measured by a laser diffraction scattering particle size distribution measuring device (e.g., Beckman Coulter LS13320). Alternatively, the minor axis r1 and major axis r2 of the organic particles can be determined by observation using a SEM (scanning electron microscope).

[0181] As for (X) organic particles, there are no particular restrictions as long as they are particles whose main component is organic matter. Here, "main component of organic matter" means that the proportion of organic matter in the total mass of the particles is greater than or equal to 50% by mass. The proportion of organic matter in the total mass of the particles is preferably greater than or equal to 80% by mass, more preferably greater than or equal to 90% by mass, and even more preferably substantially 100% by mass.

[0182] The components (organic compounds) constituting the (X) organic particles preferably contain at least one selected from the group consisting of polyethylene, polybutadiene, polystyrene, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene copolymer, styrene-divinylbenzene copolymer, (meth)acrylate copolymer, silicone rubber, polyvinyl alcohol, epoxy resin, polyester, polyamide, polyimide, polyamide-imide, polyurethane, polyphenylene ether, and melamine resin.

[0183] (X) Organic particles may or may not have cross-linked structures.

[0184] The (X) organic particles used in this embodiment are preferably organic particles that are easy to thresh or easy to dissolve during degumming treatment. From this viewpoint, the (X) organic particles preferably contain core-shell particles. Here, core-shell particles are polymer particles whose core and shell have different properties. In this embodiment, it is preferable that the core and shell of the particles contain different components. When the (X) organic particles contain core-shell particles, their content is not particularly limited. From the viewpoint of ease of threshing or ease of dissolution during degumming treatment, it is preferably greater than or equal to 5% by mass in the (X) organic particles, more preferably greater than or equal to 20% by mass, further preferably greater than or equal to 50% by mass, particularly preferably greater than or equal to 80% by mass, most preferably greater than or equal to 95% by mass, and practically can be 100% by mass.

[0185] While there are no particular restrictions, the core-shell particles are preferably formed from the components constituting the (X) organic particles described above. More preferably, the components constituting the core and shell are resins with low resistance to adhesive residue, excellent flexibility, and excellent compatibility and dispersibility. Examples of such resins include epoxy resins, butadiene rubber, styrene-butadiene copolymers, polyamide resins, and (meth)acrylate copolymers. Among these, epoxy resins, styrene-butadiene copolymers, and (meth)acrylate copolymers are preferred. It should be noted that when the core component is a styrene-butadiene copolymer, the adhesion strength to copper plating is further improved, and therefore it is preferred.

[0186] Examples of combinations of core- and shell-forming components (core / shell) include: styrene-butadiene copolymer / (meth)acrylate copolymer, (meth)acrylate copolymer / epoxy resin, epoxy resin / silicone rubber, acrylonitrile-butadiene copolymer / (meth)acrylate copolymer, polyethylene / (meth)acrylate copolymer, polybutadiene / (meth)acrylate copolymer, polyester / (meth)acrylate copolymer, etc. Among these, styrene-butadiene copolymer / (meth)acrylate copolymer and (meth)acrylate copolymer / epoxy resin are preferred.

[0187] Among the components constituting the organic particle (X), the core, or the shell, examples of (meth)acrylate copolymers include acrylate-methacrylate copolymers, methacrylate-styrene copolymers, and acrylate copolymers. Examples of ester sites in (meth)acrylates include alkyl esters with 1 to 12 carbon atoms (such as alkyl groups), cycloalkyl esters with 3 to 12 cyclic carbon atoms (such as cycloalkyl groups), aryl esters with 6 to 18 cyclic carbon atoms (such as phenyl groups), and aralkyl groups such as benzyl groups, as well as heterogroups in which a portion of these groups is substituted with heteroatoms.

[0188] Examples of the aforementioned acrylates include: methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-lauryl acrylate, 2-hydroxyethylhexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, tetrahydrofuran acrylate, benzyl acrylate, and phenyl acrylate. Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, and isopropyl acrylate are preferred, and methyl acrylate and ethyl acrylate are more preferred.

[0189] Examples of the aforementioned methacrylates include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, allyl methacrylate, etc. Among these, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and isopropyl methacrylate are preferred, and methyl methacrylate and ethyl methacrylate are more preferred.

[0190] Similarly, among the components constituting the organic particles (X), the core components, or the shell components, the epoxy resin is preferably a glycidyl ether type or a glycidyl amine type, and any one of them can be used, but a glycidyl ether type epoxy resin is more preferred.

[0191] Preferably, the following bisphenol-based epoxy resins can be included: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, etc.; bisphenol A phenolic varnish type epoxy resin, bisphenol F phenolic varnish type epoxy resin, etc.; phenolic varnish type epoxy resins other than the above-mentioned bisphenol-based phenolic varnish type epoxy resins, such as phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, biphenyl phenolic varnish type epoxy resin; phenolic aralkyl type epoxy resin; stilbene type epoxy resin; naphthalene type epoxy resin; Naphthalene-containing skeletal epoxy resins include: naphthol phenolic varnish epoxy resins, naphthol-type epoxy resins, naphthol aralkyl-type epoxy resins, naphthylene ether-type epoxy resins, etc.; biphenyl-type epoxy resins; biphenyl aralkyl-type epoxy resins; xylene-type epoxy resins; dihydroanthracene-type epoxy resins; dicyclopentadiene-type epoxy resins, etc.; heterocyclic epoxy resins; spirocyclic epoxy resins; cyclohexanediol-type epoxy resins; trimethylol-type epoxy resins; aliphatic chain epoxy resins; rubber-modified epoxy resins, etc. Among these, preferred are bisphenol-based phenolic varnish-type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A phenolic varnish-type epoxy resin, and bisphenol F phenolic varnish-type epoxy resin; and phenolic varnish-type epoxy resins other than the aforementioned bisphenol-based phenolic varnish-type epoxy resins such as phenol phenolic varnish-type epoxy resin and cresol phenolic varnish-type epoxy resin.

[0192] Core-shell particles can be prepared using conventional methods, such as emulsion polymerization, seed polymerization, micro-suspension polymerization, or suspension polymerization, or commercially available products can be used.

[0193] Commercially available products containing core-shell particles include: EXL2620, EXL2650, EXL2655, TMS-2670, BTA-717, and BTA-731 (all manufactured by Toray Industries, Inc.) as part of the Paraaloid (registered trademark) series; and MX-153, MX-128, MX-139, MX-257, MX-136, and MX-217 (all manufactured by Kaneka Corporation) as part of the KaneAce (registered trademark) MX series.

[0194] From the viewpoint of pore resolution and surface shape after degumming treatment, the average primary particle size (volume average particle size) of the organic particles (X) is preferably less than or equal to 0.5 μm, more preferably 0.01 to 0.5 μm, even more preferably 0.01 to 0.2 μm, and can be 0.01 to 0.15 μm or 0.01 to 0.10 μm. The same applies to the average particle size of the core-shell particles. It should be noted that in this specification, the average primary particle size (volume average particle size) is defined as the particle size at 50% (volume basis) of the cumulative value of the particle size distribution obtained by measuring particles dispersed in a solvent using a Zeta potential-particle size distribution measuring device (Beckman-Coultre), according to international standard ISO 13321, with a refractive index of 1.38.

[0195] (Content of component (X))

[0196] (X) The content of organic particles is not particularly limited, but from the viewpoints of through-hole resolution, adhesion strength to copper plating, electrical insulation reliability and crack resistance, it is preferably 1 to 60% by mass, more preferably 3 to 50% by mass, based on the total solid content of the photosensitive resin composition. Further, from the viewpoint of making the crack resistance more sufficient, it is more preferably 5 to 40% by mass, particularly preferably 7 to 35% by mass, and most preferably 8 to 20% by mass, from the viewpoint of making the through-hole resolution more sufficient.

[0197] <(B) Photopolymerization initiators>

[0198] As for component (B) used in this embodiment, there are no particular limitations as long as it can polymerize the above-mentioned component (A), and it can be appropriately selected from commonly used photopolymerization initiators.

[0199] As component (B), examples include: benzoin compounds such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone compounds such as 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-1-propanone, and N,N-dimethylaminoacetophenone; anthraquinone compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-pentylanthraquinone, and 2-aminoanthraquinone; and thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone. Ketal compounds such as acetophenone dimethyl ketal and benzoyl dimethyl ketal; benzophenone compounds such as methyl benzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Mischel ketone, and 4-benzoyl-4'-methyl diphenyl sulfide; acridine compounds such as 9-phenyl acridine and 1,7-bis(9,9'-acridyl)heptane; 2,4,6-trimethylamine... Acylphosphine oxide compounds such as methylbenzoyl diphenylphosphine oxide; oxime ester compounds such as 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl] ethyl ketone-1-(O-acetyl oxime), and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl) oxime]. Among these, acetophenone compounds and thioxanthone compounds are preferred, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone are more preferred. Acetophenone compounds have the advantages of being non-volatile and not easily generated as escape gases, while thioxanthone compounds have the advantage of being photocurable in the visible light region.

[0200] (B) Components may be used alone or in combination with two or more. When two or more are used together, it is preferable to use acetophenone compound and thioxanthone compound together, and more preferably to use 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone together.

[0201] ((B) Content of component)

[0202] The content of component (B) is not particularly limited, but based on the total solid content of the photosensitive resin composition, it is preferably 0.1 to 15% by mass, more preferably 0.15 to 5% by mass, even more preferably 0.15 to 1.5% by mass, and particularly preferably 0.20 to 0.8% by mass. If the content of component (B) is greater than or equal to 0.1% by mass, there is a tendency to reduce the possibility of the exposed area dissolving during development in the interlayer insulating layer formed by using the photosensitive resin composition; if it is less than or equal to 15% by mass, there is a tendency to improve heat resistance.

[0203] <(B') Photopolymerization initiator>

[0204] The photosensitive resin composition of this embodiment may also contain both component (B) and photopolymerization initiator (B'). Examples of photopolymerization initiators (B') include ethyl N,N-dimethylaminobenzoate, isoamyl N,N-dimethylaminobenzoate, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine, and other tertiary amine compounds. Component (B') may be used alone or in combination with two or more components.

[0205] When the photosensitive resin composition of this embodiment contains component (B'), the content of component (B') is preferably 0.01 to 20% by mass, more preferably 0.2 to 5% by mass, and even more preferably 0.3 to 2% by mass, based on the total amount of resin components in the photosensitive resin composition. It should be noted that the photosensitive resin composition of this embodiment may also be free of component (B').

[0206] <(C) Thermosetting Resins>

[0207] The photosensitive resin composition of this embodiment may further contain a thermosetting resin as component (C), which is preferred. Component (C) does not contain any substance equivalent to component (A) above, and from this point of view, it can be said that component (C) does not have vinyl unsaturated groups. In addition, based on satisfying the condition of not having vinyl unsaturated groups, a substance having epoxy groups (such as epoxy-modified polybutadiene) is included in component (C). Furthermore, component (C) is not in particle shape, and therefore does not contain the organic particles described above (X).

[0208] The photosensitive resin composition of this embodiment contains (C) thermosetting resin, which tends to improve not only the adhesion strength and insulation reliability with copper plating, but also the heat resistance.

[0209] Examples of thermosetting resins include epoxy resins, phenolic resins, unsaturated imide resins, cyanate ester resins, isocyanate ester resins, and benzo[a]benzene resins. Azide resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, melamine resins, etc. Furthermore, not particularly limited to these, known thermosetting resins can be used. Among these, epoxy resins are preferred.

[0210] (C) Components may be used alone or in combination with two or more.

[0211] As an epoxy resin, an epoxy resin having two or more epoxy groups is preferred. Epoxy resins can be classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0212] In addition, epoxy resins can also be classified into various types based on their main skeleton. Among the above-mentioned types of epoxy resins, they can be further classified as follows: Specifically, they can be classified as: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and other bisphenol-based epoxy resins; bisphenol A phenolic varnish type epoxy resin, bisphenol F phenolic varnish type epoxy resin, and other bisphenol-based phenolic varnish type epoxy resins; phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, biphenyl phenolic varnish type epoxy resin, and other phenolic varnish type epoxy resins other than the above-mentioned bisphenol-based phenolic varnish type epoxy resins; phenol aryl alkyl type epoxy resin; stilbene type epoxy resin; naphthalene type epoxy resin; and cyclohexane type epoxy resin. Epoxy resins containing naphthalene skeletons, including naphthalene-based epoxy resins, naphthol phenolic varnish-type epoxy resins, naphthol-type epoxy resins, naphthol aralkyl-type epoxy resins, and naphthylene ether-type epoxy resins; biphenyl-type epoxy resins; biphenyl aralkyl-type epoxy resins; xylene-type epoxy resins; dihydroanthracene-type epoxy resins; dicyclopentadiene-type epoxy resins; heterocyclic epoxy resins; spirocyclic epoxy resins; cyclohexanediol-type epoxy resins; trimethylol-type epoxy resins; aliphatic chain epoxy resins; and rubber-modified epoxy resins.

[0213] (C) Components may be used alone or in combination with two or more.

[0214] Among these, especially from the viewpoints of heat resistance, electrical insulation reliability, and adhesion strength to copper plating, bisphenol-based epoxy resins, naphthol-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, and cresol phenolic varnish-type epoxy resins are preferred; bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and biphenyl-type epoxy resins are more preferred; bisphenol F-type epoxy resins and biphenyl-type epoxy resins are even more preferred; and biphenyl-type epoxy resins are particularly preferred.

[0215] These can also be commercially available products, such as: bisphenol A type epoxy resin ("jER828EL", "YL980" manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resin ("jER806H", "YL983U" manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resin ("HP4032D", "HP4710" manufactured by DIC Corporation), naphthalene-containing skeleton type multifunctional epoxy resin ("NC7000" manufactured by Nippon Kayaku Co., Ltd.), and naphthol type epoxy resin ("ESN-475V" manufactured by Nippon Steel Chemical & Materials Co., Ltd.). Epoxy resins with biphenyl structures (NC3000H and NC3500 manufactured by Nippon Kayaku Co., Ltd.), YX4000HK and YL6121 manufactured by Mitsubishi Chemical Co., Ltd., anthracene-type epoxy resins (YX8800 manufactured by Mitsubishi Chemical Co., Ltd.), glycerol-type epoxy resins (ZX1542 manufactured by Nippon Steel Chemical & Materials Co., Ltd.), naphthyl ether-type epoxy resins (EXA7311-G4 manufactured by DIC Corporation), and cresol phenolic varnish-type epoxy resins (EPICLON N-680 manufactured by DIC Corporation), etc.

[0216] In addition to the examples described above, epoxy-modified polybutadiene can also be used as the epoxy resin for component (C). Particularly, from the viewpoint of processability during the manufacture of printed circuit boards, it is preferable to use both an aromatic epoxy resin that is solid at room temperature and an epoxy resin that is liquid at room temperature as component (C). From this viewpoint, it is preferable to use the epoxy resin (aromatic epoxy resin that is solid at room temperature) and epoxy-modified polybutadiene (epoxy resin that is liquid at room temperature) as exemplified as preferred substances. In this case, the content ratio of the two used (aromatic epoxy resin that is solid at room temperature / epoxy resin that is liquid at room temperature) is preferably 95 / 5 to 60 / 40 by mass, more preferably 95 / 5 to 70 / 30, and even more preferably 95 / 5 to 80 / 20.

[0217] The epoxy-modified polybutadiene described above preferably has hydroxyl groups at the ends of the molecules, more preferably has hydroxyl groups at both ends of the molecules, even more preferably has hydroxyl groups only at the ends of the molecules, and particularly preferably has hydroxyl groups only at both ends of the molecules. Furthermore, there is no particular limitation as long as the epoxy-modified polybutadiene has one or more hydroxyl groups; preferably 1 to 5, more preferably 1 or 2, and even more preferably 2.

[0218] From the viewpoints of adhesion strength to copper plating, heat resistance, coefficient of thermal expansion and flexibility, the epoxy-modified polybutadiene described above is preferably the epoxy-modified polybutadiene represented by the following general formula (C-1).

[0219] [Chemistry 6]

[0220]

[0221] (In the above formula (C-1), a, b, and c represent the ratios of the structural units within the brackets, where a is 0.05–0.40, b is 0.02–0.30, and c is 0.30–0.80. Furthermore, a+b+c = 1.00 and (a+c) > b. y represents the number of structural units within the square brackets, which is an integer from 10 to 250.)

[0222] In the above general formula (C-1), the order in which the structural units within the square brackets are combined is different. That is, the structural units shown on the left, the structural units shown in the center, and the structural units shown on the right can be interleaved. When represented by (a), (b), and (c) respectively, there can be various combination sequences such as -[(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)-]-.

[0223] From the viewpoints of adhesion strength, heat resistance, coefficient of thermal expansion, and flexibility with copper plating, 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. Furthermore, from the same viewpoint, y is preferably an integer from 30 to 180.

[0224] In the above general formula (C-1), commercially available epoxidized polybutadiene products with integers a=0.20, b=0.20, c=0.60, and y=10~250 can be listed as "Epolead (registered trademark) PB3600" (Dairu Corporation).

[0225] (C) Content of component

[0226] When the photosensitive resin composition of this embodiment contains component (C), its content is not particularly limited. Based on the total solid content of the photosensitive resin composition, it is preferably 5 to 70% by mass, more preferably 5 to 40% by mass, even more preferably 7 to 30% by mass, and particularly preferably 10 to 20% by mass. If the content of component (C) is greater than or equal to 5% by mass, there is a tendency to obtain sufficient cross-linking of the photosensitive resin composition, and improved adhesion strength and electrical insulation reliability to copper plating. On the other hand, if it is less than or equal to 70% by mass, there is a tendency to achieve good through-hole resolution.

[0227] <(D) Elastomers>

[0228] The photosensitive resin composition of this embodiment may contain an elastomer as component (D), which is preferred. By containing component (D), it tends to become a photosensitive resin composition with excellent through-hole resolution, adhesion strength to copper plating, and electrical insulation reliability. In addition, component (D) also has the effect of suppressing the reduction in flexibility and adhesion strength to copper plating caused by the internal strain (internal stress) of the cured product due to the curing shrinkage of component (A) mentioned above.

[0229] As component (D), the elastomer is preferably liquid at 25°C.

[0230] (D) Components may be used alone or in combination with two or more.

[0231] Examples of elastomers include styrene-based elastomers, olefin-based elastomers, polyester-based elastomers, urethane-based elastomers, polyamide-based elastomers, acrylic elastomers, and silicone-based elastomers. Preferably, at least one selected from these elastomers is used. These elastomers contain hard segment components and soft segment components; the former tends to contribute to heat resistance and strength, while the latter tends to contribute to flexibility and toughness.

[0232] As component (D), in the above examples, from the viewpoint of compatibility, solubility, and adhesion strength to copper plating, it is preferable to include at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, and more preferably, a polyester-based elastomer. Furthermore, component (D) is further preferably at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, and particularly preferably, a polyester-based elastomer.

[0233] (Styrene-based elastomers)

[0234] Examples of styrene-based elastomers include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-butene-styrene block copolymers, and styrene-ethylene-propylene-styrene block copolymers. A single styrene-based elastomer may be used, or two or more may be used in combination.

[0235] As components constituting styrene-based elastomers, examples include: styrene; styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene.

[0236] As a styrene-based elastomer, the preferred number average molecular weight is 1,000 to 50,000, and more preferably 3,000 to 20,000.

[0237] In this specification, the number-average molecular weight is a value obtained by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent and converted using standard polystyrene.

[0238] Styrene-based elastomers can also be commercially available.

[0239] (Olefin-based elastomers)

[0240] The aforementioned olefin-based elastomers are polymers or copolymers of α-olefins with 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, and 4-methylpentene. It should be noted that the olefin-based elastomers may have hydroxyl groups at the molecular ends, preferably. One olefin-based elastomer may be used alone, or two or more may be used in combination.

[0241] Examples of preferred olefin-based elastomers include polyethylene, polybutadiene, hydroxyl-containing polybutadiene, hydroxyl-containing polyisopropylene, ethylene-propylene copolymer (EPR), and ethylene-propylene-diene copolymer (EPDM). Additionally, copolymers of the aforementioned α-olefins with 2 to 20 carbon atoms with non-conjugated dienes with 2 to 20 carbon atoms, such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, butadiene, and isoprene, are also possible. Furthermore, carboxyl-modified NBRs formed by copolymerizing butadiene-acrylonitrile copolymers with methacrylic acid are also possible.

[0242] As an olefin-based elastomer, the number average molecular weight is preferably 1,000 to 8,000, more preferably 1,500 to 6,500.

[0243] Olefin-based elastomers can also be commercially available.

[0244] (Polyester-based elastomers)

[0245] Examples of polyester elastomers include substances obtained by polycondensation of dicarboxylic acids or their derivatives and diol compounds or their derivatives. A single polyester elastomer may be used, or two or more may be used in combination.

[0246] Examples of the aforementioned dicarboxylic acids include: aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; aromatic dicarboxylic acids obtained by substituting the hydrogen atoms of the aromatic rings of the aforementioned aromatic dicarboxylic acids with methyl, ethyl, or phenyl groups; aliphatic dicarboxylic acids with 2 to 20 carbon atoms such as adipic acid, sebacic acid, and dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. From the viewpoint of adhesion to the substrate, dimer acids derived from natural sources are preferred as dicarboxylic acids. A single dicarboxylic acid may be used, or two or more may be used in combination.

[0247] As derivatives of the aforementioned dicarboxylic acids, anhydrides of the aforementioned dicarboxylic acids can be listed.

[0248] Examples of the aforementioned diol compounds include: aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; alicyclic diols such as 1,4-cyclohexanediol; and aromatic diols represented by the following general formula (D-1). A single diol compound may be used alone, or two or more may be used in combination.

[0249] [Chemistry 7]

[0250]

[0251] (In general formula (D-1), X) D1 Represents alkylene groups with 1 to 10 carbon atoms, alkylene groups with 2 to 10 carbon atoms, cycloalkylene groups with 4 to 8 carbon atoms, -O-, -S-, and -SO2-. R D1 and R D2 Each denotes a halogen atom or an alkyl group having 1 to 12 carbon atoms, respectively. p and q are independent integers from 0 to 4, and r is 0 or 1.

[0252] In general formula (D-1), X is... D1 Examples of alkylene groups having 1 to 10 carbon atoms include methylene, 1,2-dimethylene, 1,3-trimethylene, 1,4-tetramethylene, and 1,5-pentamethylene. From the viewpoints of pore resolution, adhesion strength to copper plating, and electrical insulation reliability, alkylene groups having 1 to 3 carbon atoms are preferred, and methylene is more preferred.

[0253] As X D1 Examples of alkylidene groups with 2 to 10 carbon atoms include ethoxyl, propionyl, isopropionyl, butyryl, isobutyryl, pentyl, and isopentyl. From the viewpoints of through-hole resolution, adhesion strength to copper plating, and electrical insulation reliability, isopropionyl is preferred as the alkylidene group.

[0254] As X D1 Examples of cycloalkyl groups with 4 to 8 carbon atoms include cyclopentylene, cyclohexylene, and cyclooctylene.

[0255] As X D1 Of the above, alkylene groups with 1 to 10 carbon atoms and alkylidene groups with 2 to 10 carbon atoms are preferred, and methylene and isopropylidene groups are more preferred.

[0256] In general formula (D-1), R is... D1 and R D2 The halogen atoms represented can include fluorine, chlorine, bromine, iodine, etc.

[0257] As R D1 and R D2Examples of alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferably, the alkyl group has 1 to 6 carbon atoms; more preferably, it has 1 to 3 carbon atoms; and methyl is even more preferred.

[0258] p and q are independent integers from 0 to 4, preferably 0 or 1 respectively.

[0259] r can be 0 or 1, either of which is acceptable. When r is 0, it becomes the structure represented by the following general formula (D-1').

[0260] [Chemistry 8]

[0261]

[0262] (In the general formula (D-1'), X D1 R D1 Both p and p are the same as in general formula (D-1), and the preferred method is also the same.

[0263] Examples of aromatic diols represented by the above general formula (D-1) include bisphenol A, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)propane, and resorcinol.

[0264] Furthermore, as a polyester-based elastomer, a multi-block copolymer can also be used, in which an aromatic polyester (e.g., polybutylene terephthalate) portion is used as the hard segment component and an aliphatic polyester (e.g., polytetramethylene glycol) portion is used as the soft segment component, and this multi-block copolymer is preferred. Various grades of commercially available products are available as such multi-block copolymers, depending on the type, ratio, and molecular weight of the hard and soft segments. Specifically, examples include: "Hytrel (registered trademark)" (manufactured by Toray DuPont, Ltd.), "Pelprene (registered trademark)" (manufactured by Toyobo, Ltd.), "Espel (registered trademark)" and "Teslac (registered trademark)" (manufactured by Showa Denko Materials Co., Ltd.), etc.

[0265] As a polyester elastomer, the number average molecular weight is preferably 900 to 30,000, more preferably 1,000 to 25,000, and even more preferably 5,000 to 20,000.

[0266] (Carbamate-based elastomers)

[0267] As the aforementioned urethane-based elastomers, preferably examples include substances containing hard segments comprising short-chain diols and diisocyanates, and soft segments comprising high-molecular-weight (long-chain) diols and diisocyanates. A single urethane-based elastomer may be used, or two or more may be used in combination.

[0268] Examples of high molecular weight (long-chain) diols include polypropylene glycol, polytetraformaldehyde, poly(1,4-butene adipate), poly(ethylene-1,4-butene adipate), polycaprolactone, poly(1,6-hexene carbonate), and poly(1,6-hexene neopentene adipate). The number average molecular weight of these high molecular weight (long-chain) diols is preferably between 500 and 10,000.

[0269] Examples of short-chain diols include ethylene glycol, propylene glycol, 1,4-butanediol, and bisphenol A. The preferred number-average molecular weight of short-chain diols is 48–500.

[0270] As a urethane-based elastomer, the preferred number average molecular weight is 1,000 to 25,000, more preferably 1,500 to 20,000, and even more preferably 2,000 to 15,000.

[0271] Carbamate-based elastomers are also available in commercially available products.

[0272] (Polyamide elastomers)

[0273] Polyamide elastomers can be broadly classified into two types: polyether block amides, which use polyamide in the hard segments and polyether in the soft segments; and polyether ester block amides, which use polyamide in the hard segments and polyester in the soft segments.

[0274] Specific examples of the aforementioned polyamide-based elastomers include block copolymers with polyamide as the hard segment component and polybutadiene, butadiene-acrylonitrile copolymer, styrene-butadiene copolymer, polyisoprene, ethylene-propylene copolymer, polyether, polyester, polybutadiene, polycarbonate, polyacrylate, polymethacrylate, polyurethane, and silicone rubber as the soft segment component. Polyamide-based elastomers can be used alone or in combination with two or more types.

[0275] As a polyamide-based elastomer, the number average molecular weight is preferably 1,000 to 50,000, and more preferably 2,000 to 30,000.

[0276] Commercially available polyamide elastomers are also available.

[0277] (Acrylic elastomer)

[0278] Examples of acrylic elastomers include polymers of monomers primarily composed of acrylates. Preferred acrylates include ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and ethoxyethyl acrylate. Furthermore, crosslinking monomers can be copolymers of acrylates with glycidyl methacrylate, allyl glycidyl ether, etc., or copolymers of acrylonitrile, ethylene, etc., with acrylates or with acrylates and crosslinking monomers. Specifically, examples include acrylonitrile-butyl acrylate copolymers, acrylonitrile-butyl acrylate-ethyl acrylate copolymers, and acrylonitrile-butyl acrylate-glycidyl methacrylate copolymers. Acrylic elastomers can be used alone or in combination of two or more.

[0279] As an acrylic elastomer, the number average molecular weight is preferably 1,000 to 50,000, and more preferably 2,000 to 30,000.

[0280] Commercially available acrylic elastomers are also acceptable.

[0281] (Organosilicon-based elastomers)

[0282] The aforementioned organosilicon elastomers are elastomers with organopolysiloxanes as the main component, and can be classified as, for example, polydimethylsiloxane elastomers, polymethylphenylsiloxane elastomers, polydiphenylsiloxane elastomers, etc. Organosilicon elastomers can be used alone or in combination with two or more types.

[0283] As an organosilicon-based elastomer, the number average molecular weight is preferably 1,000 to 50,000, and more preferably 2,000 to 30,000.

[0284] Silicone-based elastomers can also be commercially available.

[0285] (Other elastomers)

[0286] Additionally, component (D) may also be a composition comprising at least one selected from the group consisting of polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamide-imide resin, polyimide resin, xylene resin, polyphenylene sulfide resin, polyetherimide resin, polyether ether ketone resin, tetrafluoroethylene resin, polyacrylonitrile resin, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxyl-modified polyacrylonitrile.

[0287] (Content of component (D))

[0288] When the photosensitive resin composition of this embodiment contains component (D), the content of component (D) is preferably 0.5 to 20% by mass, more preferably 0.5 to 15% by mass, further preferably 0.5 to 10% by mass, particularly preferably 1.0 to 6% by mass, and most preferably 1.0 to 4.0% by mass, based on the total amount of solid components in the photosensitive resin composition. If the content of component (D) is greater than or equal to 0.5% by mass, there is a tendency for the improvement effect on the adhesion strength with copper plating to become sufficient and the electrical insulation reliability to be further improved. If the content of component (D) is less than or equal to 20% by mass, there is a tendency for the through-hole resolution, adhesion strength with copper plating, and electrical insulation reliability to all become sufficient.

[0289] <(E) Thermal polymerization initiator>

[0290] The photosensitive resin composition of this embodiment may also contain a thermal polymerization initiator as component (E).

[0291] As thermal polymerization initiators, there are no particular limitations, but examples include: dicumyl peroxide "Percumyl P", isocumyl peroxide "Percumyl H", tert-butyl peroxide "Perbutyl H" (all manufactured by Nippon Oil Co., Ltd.); α,α-bis(tert-butylperoxide-m-isopropyl)benzene "Perbutyl P", dicumyl peroxide "Percumyl D", 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane "Perhexa 25B", tert-butylcumyl peroxide "Perbutyl C", di-tert-butyl peroxide "Perbutyl D", 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexyne-3 "Perhexyne 25B", tert-butylperoxide-2-ethylhexanoate "Perbutyl Dialkyl peroxide compounds such as "O" (manufactured by Nippon Oil Co., Ltd.); ketone peroxide compounds; peroxide ketal compounds such as n-butyl 4,4-bis(tert-butylperoxy)valerate "Perhexa V" (manufactured by Nippon Oil Co., Ltd.); diacyl peroxide compounds; peroxide dicarbonate compounds; peroxide ester compounds and other organic peroxides; azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). Among these, dialkyl peroxide compounds are preferred from the viewpoint of maximizing the effect of not hindering photopolymerization and improving the physical properties and characteristics of the photosensitive resin composition, and more preferably 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3.

[0292] Thermal polymerization initiators can be used alone or in combination with two or more.

[0293] (Content of component (E))

[0294] When the photosensitive resin composition of this embodiment contains component (E), its content is not particularly limited. Based on the total amount of resin components in the photosensitive resin composition, it is preferably 0.01 to 5% by mass, more preferably 0.02 to 3% by mass, and even more preferably 0.03 to 2% by mass. If it is greater than or equal to 0.01% by mass, there is a tendency for it to be sufficiently thermosetting, and if it is less than or equal to 5% by mass, there is a tendency for the photosensitive properties and heat resistance to become good.

[0295] <(F) Inorganic filler materials>

[0296] The photosensitive resin composition of this embodiment may contain an inorganic filler as component (F), preferably an inorganic filler. By containing an inorganic filler, low thermal expansion can be achieved, reducing the likelihood of warping. In conventional thermosetting resin compositions used as interlayer insulating layers in multilayer printed circuit boards, low thermal expansion is achieved by containing an inorganic filler. However, when a photosensitive resin composition contains an inorganic filler, the inorganic filler becomes a cause of light scattering and an obstacle to development, making it difficult to achieve low thermal expansion by including it in large quantities. Thus, a new problem unique to photosensitive resin compositions exists when inorganic fillers are included. However, the photosensitive resin composition of this embodiment tends to maintain a high via resolution even when containing an inorganic filler. Therefore, with the photosensitive resin composition of this embodiment, both low thermal expansion and high via resolution can be achieved.

[0297] As components of (F), the following can be listed: silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), silicon nitride (Si3N4), barium titanate (BaO·TiO2), barium carbonate (BaCO3), magnesium carbonate (MgCO3), aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), lead titanate (PbO·TiO2), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga2O3), spinel (MgO·Al2O3). The following components are listed: l2O3, mullite (3Al2O3·2SiO2), cordierite (2MgO·2Al2O3 / 5SiO2), talc (3MgO·4SiO2·H2O), aluminum titanate (TiO2·Al2O3), yttrium-containing zirconium oxide (Y2O3·ZrO2), barium silicate (BaO·8SiO2), boron nitride (BN), calcium carbonate (CaCO3), barium sulfate (BaSO4), calcium sulfate (CaSO4), zinc oxide (ZnO), magnesium titanate (MgO·TiO2), hydrotalcite, mica, calcined kaolin, carbon, etc. (F) Components may be used alone or in combination with two or more.

[0298] As component (F), from the viewpoint of heat resistance and low thermal expansion, it is preferable to include silica, more preferably silica. In addition, from the viewpoint of improving the dispersibility of inorganic filler materials in the photosensitive resin composition by utilizing the anti-agglomeration effect, component (F) may also be a substance that has been surface-treated with alumina or an organosilane compound.

[0299] From the viewpoint of pore resolution, the average particle size of component (F) is preferably 0.01 to 5 μm, more preferably 0.1 to 3 μm, even more preferably 0.1 to 2 μm, and particularly preferably 0.1 to 1 μm. Here, the average particle size of component (F) is the volume average particle size of the inorganic filler material dispersed in the photosensitive resin composition, and is set as a value obtained by the following determination: First, the photosensitive resin composition is diluted (or dissolved) to 1,000 times using methyl ethyl ketone, and then the particles dispersed in the solvent are measured using a submicron particle analyzer (Beckman-Coultre Corporation, trade name: N5) according to international standard ISO 13321, with a refractive index of 1.38. The particle size at 50% (volume basis) of the cumulative value in the particle size distribution is taken as the average particle size (volume average particle size). In addition, the (F) component contained in the photosensitive resin film and the interlayer insulating layer disposed on the carrier film can also be diluted (or dissolved) to 1,000 times (volume ratio) using a solvent as described above, and then measured using the submicron particle analyzer described above.

[0300] (Content of component (F))

[0301] When the photosensitive resin composition of this embodiment contains component (F), its content is not particularly limited. Based on the total amount of solid components in the photosensitive resin composition, it is preferably 5 to 80% by mass, more preferably 15 to 60% by mass, even more preferably 15 to 50% by mass, particularly preferably 20 to 35% by mass, and most preferably 23 to 27.5% by mass. If the content of component (F) is within the above range, mechanical strength, heat resistance, and pore resolution can be improved.

[0302] <(G) Pigment>

[0303] To adjust photosensitivity, the photosensitive resin composition of this embodiment may contain a pigment as component (G) depending on the desired color. As component (G), any colorant that presents the desired color can be appropriately selected and used; preferably, known colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, carbon black, and naphthalene black are examples.

[0304] (Content of component (G))

[0305] When the photosensitive resin composition of this embodiment contains component (G), from the viewpoint of adjusting photosensitivity, the content of component (G) is preferably 0.01 to 5% by mass, more preferably 0.03 to 3% by mass, and even more preferably 0.05 to 2% by mass, based on the total amount of solid components in the photosensitive resin composition.

[0306] <(H) Curing agent or curing accelerator>

[0307] From the viewpoint of further improving properties such as heat resistance, adhesion strength to copper plating, and chemical resistance, the photosensitive resin composition of this embodiment may also contain a curing agent or a curing accelerator. In particular, when the aforementioned thermosetting resin (C) contains epoxy resin, an epoxy resin curing agent is preferred as the curing agent.

[0308] As component (H), examples include: active ester-based curing agents; imidazole derivatives such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; guanidine compounds such as acetylguanidine and benzoguanidine; polyamine compounds such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenyl sulfone, dicyandiamide, urea, urea derivatives, melamine, and polyhydrazides; organic acid salts or epoxy adducts of the above imidazole derivatives, guanidine compounds, and polyamine compounds; and organic acid salts and epoxy adducts of the above imidazole derivatives, guanidine compounds, and polyamine compounds. Amine complexes of boron trifluoride; triazine derivatives such as ethyldiaminotriazine, 2,4-diaminotriazine, and 2,4-diamino-6-dimethyltriazine; tertiary amine compounds such as trimethylamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine, and m-aminophenol; polyphenol compounds such as polyvinylphenol, polyvinylphenol bromide, phenolic varnish, and alkylphenolic varnish; organophosphorus compounds such as tributylphosphine, triphenylphosphine, and tri-2-cyanoethylphosphine; tri-n-butyl(2,5-dihydroxyphenyl)bromide Hexadecyltributyl chloride wait Salts; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the above-mentioned polybasic acid anhydrides; diphenyliodine Tetrafluoroborate, triphenyl sulfide Hexafluoroantimonate, 2,4,6-triphenylthiopyran Hexafluorophosphate, etc.

[0309] Among these, from the viewpoint of further improving properties such as heat resistance, adhesion strength to copper plating, and chemical resistance, polyamine compounds are preferred, and melamine is more preferred.

[0310] When the photosensitive resin composition of this embodiment contains component (H), the content of component (H) is preferably 0.01 to 20% by mass, more preferably 0.02 to 10% by mass, and even more preferably 0.03 to 3% by mass, based on the total amount of resin components in the photosensitive resin composition.

[0311] <Diluent>

[0312] In the photosensitive resin composition of this embodiment, a diluent may be used as needed. Examples of diluents include organic solvents. Examples of organic solvents include: ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, propylene glycol monoethyl ether acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One diluent may be used alone, or two or more may be used in combination. Ketones and esters are preferred as diluents, and esters are more preferred.

[0313] (Diluent content)

[0314] The amount of diluent can be adjusted to achieve a concentration of 40-90% by mass, more preferably 50-80% by mass, and even more preferably 55-70% by mass of the total solid components in the photosensitive resin composition. By adjusting the amount of diluent used in this way, the coatability of the photosensitive resin composition is improved, and more intricate patterns can be formed.

[0315] <Other Additives>

[0316] The photosensitive resin composition of this embodiment may contain, as needed, polymerization inhibitors such as hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; tackifiers such as bentonite and montmorillonite; defoamers such as silicone-based defoamers, fluorinated defoamers, and vinyl resin-based defoamers; and various commonly used additives such as silane coupling agents. Furthermore, it may also contain flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, and phosphorus-based phosphate compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters; and thermoplastic resins such as polyester polyurethane resins.

[0317] The photosensitive resin composition of this embodiment can be obtained by mixing and blending the various components using a roller mill, bead mill, or the like.

[0318] Here, the photosensitive resin composition of this embodiment can be a liquid or a film.

[0319] When using a liquid photosensitive resin composition, the coating method of the photosensitive resin composition in this embodiment is not particularly limited, and various coating methods such as printing, spin coating, spraying, jet dispensing, inkjet, and dip coating can be listed. From the viewpoint of making it easier to form a photosensitive layer, any suitable method such as printing or spin coating can be selected.

[0320] Furthermore, when using a film-like photosensitive resin composition, for example, it can be used in the form of a photosensitive resin film as described later. In this case, a photosensitive layer of the desired thickness can be formed by laminating it onto a carrier film using a laminator or the like. It should be noted that when using a film-like photosensitive resin composition, the manufacturing efficiency of multilayer printed circuit boards is increased, and therefore it is preferred.

[0321] [Photosensitive resin film, photosensitive resin film for interlayer insulating layer]

[0322] The photosensitive resin film of this embodiment is a photosensitive layer that subsequently becomes an interlayer insulating layer, and includes the photosensitive resin composition of this embodiment. The photosensitive resin film of this embodiment may also be provided on a carrier film.

[0323] There is no particular limitation on the thickness (thickness after drying) of the photosensitive resin film (photosensitive layer), but from the viewpoint of thinning multilayer printed circuit boards, it is preferably 1 to 100 μm, more preferably 1 to 50 μm, and even more preferably 5 to 40 μm.

[0324] The photosensitive resin film of this embodiment can be obtained, for example, by coating the photosensitive resin composition of this embodiment onto a carrier film using a known coating apparatus such as a corner-cutting wheel coater, a rod coater, a coincidence coater, a roller coater, a gravure coater, or a die coater, and then drying it to form a photosensitive layer that later becomes an interlayer insulating layer.

[0325] Examples of suitable carrier films include polyester films such as polyethylene terephthalate (PET) films and polybutylene terephthalate (PET) films; and polyolefin films such as polypropylene (PP) films and polyethylene (PE) films. The thickness of the carrier film can be appropriately selected within the range of 5–100 μm, preferably 5–60 μm, and more preferably 15–45 μm.

[0326] Alternatively, a protective film can be provided on the surface of the photosensitive resin film of this embodiment, opposite to the surface in contact with the carrier film. As the protective film, polymer films such as polyethylene and polypropylene can be used. Alternatively, the same polymer film as the carrier film described above can be used, or a different polymer film can be used.

[0327] In the drying of the coating film formed by applying the photosensitive resin composition, a hot air dryer, a far-infrared dryer, or a near-infrared dryer can be used. The drying temperature is preferably 60–150°C, more preferably 70–120°C, and even more preferably 80–100°C. The drying time is preferably 1–60 minutes, more preferably 2–30 minutes, and even more preferably 5–20 minutes. From the viewpoint of preventing the diffusion of diluent during the manufacturing process of the multilayer printed circuit board, the residual diluent content in the dried photosensitive resin film is preferably less than or equal to 3% by mass, more preferably less than or equal to 2% by mass, and even more preferably less than or equal to 1% by mass.

[0328] The photosensitive resin film of this embodiment is suitable for use as an interlayer insulating layer in multilayer printed circuit boards due to its excellent through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance. That is, this disclosure also provides a photosensitive resin film for interlayer insulating layers. It should be noted that the photosensitive resin film for interlayer insulating layers can also be called an interlayer insulating photosensitive film.

[0329] Multilayer printed circuit boards and their manufacturing methods

[0330] This disclosure also provides a multilayer printed circuit board comprising an interlayer insulating layer formed using the photosensitive resin composition or photosensitive resin film of this embodiment. Regarding the multilayer printed circuit board of this embodiment, as long as it includes an interlayer insulating layer formed using the photosensitive resin composition of this embodiment, its manufacturing method is not particularly limited; for example, it can be easily manufactured using the manufacturing method of the multilayer printed circuit board of this embodiment described below.

[0331] The following are examples of preferred methods for manufacturing multilayer printed circuit boards, which may be referred to as appropriate. Figure 1 A method for manufacturing a multilayer printed circuit board using the photosensitive resin film (photosensitive resin film for interlayer insulation layer) of this embodiment will be described.

[0332] The multilayer printed circuit board 100A can be manufactured, for example, by a manufacturing method including the following (1) to (4).

[0333] (1): The photosensitive resin film of this embodiment is laminated onto one or both sides of the circuit board (hereinafter referred to as "lamination process (1)").

[0334] (2): Expose and develop the photosensitive resin film laminated in (1) above to form an interlayer insulating layer with through holes (hereinafter referred to as "through hole formation process (2)").

[0335] (3): The above-mentioned through holes and the above-mentioned interlayer insulation layer are roughened (hereinafter referred to as "roughening process (3)").

[0336] (4): A circuit pattern is formed on the above-mentioned interlayer insulating layer (hereinafter referred to as "circuit pattern forming process (4)").

[0337] (Lamination process (1))

[0338] In the lamination process (1), a vacuum laminator is used to laminate the photosensitive resin film (photosensitive resin film for interlayer insulation layer) of this embodiment onto one or both sides of the circuit board (substrate 101 having circuit pattern 102). Examples of vacuum laminators include vacuum applicators manufactured by Nichigo-Morton Co., Ltd., vacuum pressure laminators manufactured by Meiki Manufacturing Co., Ltd., roller dry coating machines manufactured by Hitachi, Ltd., and vacuum laminators manufactured by Showa Denko Materials & Electronics Co., Ltd.

[0339] When a protective film is provided on the photosensitive resin film, lamination can be performed by pressing and heating the photosensitive resin film onto the circuit board while the protective film is peeled off or removed, with the photosensitive resin film in contact with the circuit board.

[0340] The lamination process can be performed, for example, by preheating the photosensitive resin film and the circuit board as needed, and then under reduced pressure at a lamination temperature of 70–130°C, a lamination pressure of 0.1–1.0 MPa, and an air pressure less than or equal to 20 mmHg (26.7 hPa), but is not particularly limited to these conditions. Furthermore, the lamination method can be intermittent or continuous using rollers.

[0341] Finally, the photosensitive resin film (hereinafter sometimes referred to as the photosensitive layer) laminated onto the circuit board is cooled to near room temperature to form an interlayer insulating layer 103. The carrier film can be peeled off here, or it can be peeled off after exposure as described later.

[0342] (Through-hole formation process (2))

[0343] In the via formation process (2), at least a portion of the photosensitive resin film laminated on the circuit board is exposed, followed by development. Through exposure, the portion irradiated by active light is photocured, thereby forming a pattern. There are no particular limitations on the exposure method. For example, a method can be used where a negative or positive mask pattern, called an artwork, is placed between the exposure device and the photosensitive resin film, and active light is irradiated onto the photosensitive resin film in an image-like manner (mask exposure method). Alternatively, a direct drawing exposure method, such as LDI (Laser Direct Imaging) exposure method or DLP (Digital Light Processing) exposure method, can be used to irradiate the photosensitive resin film with active light in an image-like manner.

[0344] As the light source for the active light, known light sources can be used. Specifically, examples of light sources include: gas lasers such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers; solid-state lasers such as YAG lasers; and lasers that effectively emit ultraviolet or visible light, such as semiconductor lasers. The exposure amount can be appropriately selected based on the light source used and the thickness of the photosensitive layer. For example, when irradiating with ultraviolet light from a high-pressure mercury lamp, a preferred exposure amount is typically 10–1,000 mJ / cm² when the thickness of the photosensitive layer is 1–100 μm. 2 The preferred level is 15–500 mJ / cm². 2 .

[0345] During development, the uncured portion of the photosensitive layer is removed from the substrate, thereby forming an interlayer insulating layer containing the photocured material on the substrate.

[0346] If a carrier film is present on the photosensitive layer, the carrier film is removed, and then the unexposed areas are removed (developed). There are wet development and dry development methods, either of which can be used, but wet development is widely used. In this embodiment, wet development can also be used.

[0347] In the case of wet development, a developer solution corresponding to the photosensitive resin composition is used, and development is performed using a known development method. Examples of development methods include immersion, spin-dip, spraying, and methods such as brushing, tapping, scraping, and shaking immersion. Of these, spraying is preferred from the viewpoint of improving aperture resolution, and high-pressure spraying is more preferred among spraying methods. Development can be performed using only one method, or two or more methods can be combined.

[0348] The composition of the developer can be appropriately selected based on the composition of the photosensitive resin composition. Examples of developers include alkaline aqueous solutions, aqueous developers, and organic solvent-based developers. Among these, alkaline aqueous solutions are preferred as developers.

[0349] In the aperture formation process (2), after exposure and development, an injection of 0.2–10 J / cm can be performed as needed. 2 Degree (preferably 0.5-5 J / cm) 2 The interlayer insulation layer is further cured by post-UV curing with an exposure amount of UV and post-thermal curing at a temperature of 60 to 250°C (preferably 120 to 200°C). This process is preferred.

[0350] Using the above method, an interlayer insulating layer with through-hole 104 can be formed. The shape of the through-hole is not particularly limited; examples of cross-sectional shapes include quadrilaterals and inverted trapezoids (the top side is longer than the bottom side), while examples of shapes viewed from the front (the direction from which the bottom of the through-hole is visible) include circles and quadrilaterals. In the through-hole formation using photolithography in this embodiment, through-holes with an inverted trapezoidal cross-sectional shape (the top side is longer than the bottom side) can be formed. In this case, the uniformity of copper plating on the through-hole wall surface is higher, which is therefore preferable.

[0351] The diameter of the through-hole formed by this process can be set to less than or equal to 60 μm, and further, it can be set to less than 40 μm or less than or equal to 30 μm, which can achieve a smaller diameter compared with the through-hole formed by laser processing. There is no particular limitation on the lower limit of the diameter of the through-hole formed by this process, which can be greater than or equal to 15 μm or greater than or equal to 20 μm.

[0352] The size (diameter) of the through hole formed by this process is not necessarily limited to less than or equal to 60 μm. For example, it can be less than or equal to 200 μm, or it can be arbitrarily selected in the range of 15 to 300 μm.

[0353] (roughening process (3))

[0354] In the roughening process (3), a roughening liquid is used to roughen the surfaces of the vias and the interlayer insulation layer. It should be noted that if adhesive residue is generated in the above-mentioned via formation process (2), the above-mentioned roughening liquid can also be used to remove the adhesive residue. The roughening process can be carried out together with the removal of adhesive residue.

[0355] Examples of roughening solutions include chromium / sulfuric acid roughening solution, alkaline permanganate roughening solution (e.g., sodium permanganate roughening solution), and sodium fluoride / chromium / sulfuric acid roughening solution.

[0356] Anchors with irregularities are formed on the surfaces of through-holes and interlayer insulation layers through a roughening process.

[0357] (Circuit pattern formation process (4))

[0358] The circuit pattern forming process (4) is a process of forming a circuit pattern on the interlayer insulating layer after the roughening process (3).

[0359] From the perspective of forming fine wiring, the circuit pattern is preferably formed through a semi-additive process. This semi-additive process simultaneously forms the circuit pattern and creates vias.

[0360] In the semi-additive process, firstly, an electroless copper plating process is performed on the bottom of the via, the wall of the via, and the entire surface of the interlayer insulating layer after the roughening process (3) described above, using a palladium catalyst, thereby forming a seed layer 105. This seed layer is used to form a power supply layer for copper electroplating, and is preferably formed with a thickness of 0.1 to 2.0 μm. If the thickness of the seed layer is greater than or equal to 0.1 μm, there is a tendency to suppress the decrease in connection reliability during copper electroplating; if it is less than or equal to 2.0 μm, there is no need to increase the etching amount when flash etching the seed layer between the wirings, and there is a tendency to suppress the damage to the wirings caused by etching.

[0361] The above-mentioned electroless copper plating process is carried out by using the reaction of copper ions with a reducing agent to deposit metallic copper on the surface of the through-holes and interlayer insulating layers.

[0362] The electroless plating method and the electroplating method described above are both known methods and are not particularly limited. The catalyst in the electroless plating process is preferably a palladium-tin mixed catalyst, and the primary particle size of this catalyst is preferably less than or equal to 10 nm. Furthermore, the plating composition in the electroless plating process preferably contains hypophosphite. This hypophosphite acts as a reducing agent.

[0363] As an electroless copper plating solution, commercially available products can be used. Examples of commercially available products include "MSK-DK" manufactured by Atotech Japan Co., Ltd., and the "Thru-cup (registered trademark) PEA ver.4" series manufactured by Uemura Kogyo Co., Ltd.

[0364] After performing the above-described electroless copper plating process, a dry film resist is hot-pressed onto the electroless copper plating using a roller laminator. The thickness of the dry film resist must be greater than the wiring height after copper plating; from this perspective, a dry film resist with a thickness of 5–30 μm is preferred. As the dry film resist, the "Photec" series manufactured by Showa Denko Materials Co., Ltd., etc., can be used.

[0365] After hot lamination of the dry film resist, the dry film resist is exposed, for example, via a mask with a desired wiring pattern. Exposure can be performed using the same apparatus and light source used when forming through-holes in the aforementioned photosensitive resin film. After exposure, the carrier film on the dry film resist is peeled off, and development is performed using an alkaline aqueous solution to remove unexposed areas, forming the resist pattern 106. Then, if necessary, a process such as using plasma can be performed to remove developing residues from the dry film resist.

[0366] After development, copper is electroplated, thereby forming the copper circuit layer 107 and filling the vias.

[0367] After copper electroplating, the dry film resist is stripped using an alkaline aqueous solution or an amine-based stripping agent. Following the stripping of the dry film resist, the seed layer between the wirings is removed (flash etching). Flash etching is performed using acidic solutions such as sulfuric acid or hydrogen peroxide, and oxidizing solutions. Specifically, examples include "SAC" manufactured by JCU Corporation and "CPE-800" manufactured by Mitsubishi Gas Chemical Corporation. After flash etching, palladium and other substances adhering to the wirings are removed as needed. Palladium removal is preferably performed using acidic solutions such as nitric acid or hydrochloric acid.

[0368] After the dry film resist is peeled off or after flash etching, a post-baking process is preferably performed. During the post-baking process, unreacted thermosetting components are fully thermoset, thereby improving electrical insulation reliability, curing characteristics, and adhesion strength to copper plating. The thermosetting conditions vary depending on the type of resin composition, but a curing temperature of 150–240°C and a curing time of 15–100 minutes are preferred. The post-baking process completes the manufacturing process of a printed circuit board using the through-hole method in one step, but this process is repeated to manufacture the substrate depending on the required number of interlayer insulation layers. Then, a solder resist layer 108 is preferably formed on the outermost layer.

[0369] The manufacturing method of forming through-holes in a multilayer printed circuit board using the photosensitive resin composition of this embodiment has been described above. However, since the photosensitive resin composition of this embodiment has excellent pattern resolution, it is also suitable for forming cavities for housing, such as chips or passive components. The cavity can be suitably formed, for example, by setting the pattern drawn during pattern formation by exposing the photosensitive resin film in the above description of the multilayer printed circuit board to a pattern that can form the desired cavity.

[0370] Furthermore, the photosensitive resin composition of this embodiment is also useful as a surface protective film such as a solder resist.

[0371] [Semiconductor Packaging]

[0372] This disclosure also provides a semiconductor package containing the multilayer printed circuit board and semiconductor elements of this embodiment. The semiconductor package of this embodiment can be manufactured by mounting semiconductor chips, memory devices, and other semiconductor elements at predetermined locations on the multilayer printed circuit board of this embodiment, and by sealing the semiconductor elements using a sealing resin or the like.

[0373] Example

[0374] The following examples will further illustrate this embodiment in detail, but this embodiment is not limited to these examples.

[0375] It should be noted that the properties of the photosensitive resin compositions obtained in each example were evaluated using the methods shown below.

[0376] [1. Evaluation of via resolution]

[0377] (1-1) Evaluation of the fabrication of laminated bodies

[0378] The surface of the copper foil of a printed wiring board substrate (manufactured by Showa Denko Materials Co., Ltd., trade name "MCL-E-679"), which is made by laminating 12μm thick copper foil onto a glass epoxy material, is treated with a roughening treatment solution (manufactured by MEC Co., Ltd., trade name "CZ-8100"), followed by washing and drying, to obtain a roughened printed wiring board substrate.

[0379] Next, the protective film was peeled off from the "photosensitive resin film with a carrier film and a protective film bonded together" manufactured in each embodiment and comparative example. The exposed photosensitive resin film was placed in contact with the copper foil of the printed circuit board substrate that had been roughened as described above, and then lamination was performed using a pressure-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name "MVLP-500"). It should be noted that the lamination conditions were set as follows: hot plate temperature 70°C, vacuum time 20 seconds, lamination pressing time 30 seconds, air pressure less than or equal to 4 kPa, and pressing pressure 0.4 MPa. After lamination, the substrate was left at room temperature for more than or equal to 1 hour to obtain an evaluation laminate in which a photosensitive resin film and a carrier film were sequentially laminated on the copper foil surface of the printed circuit board substrate.

[0380] (1-2) Sensitivity determination of photosensitive resin films

[0381] After peeling off and removing the carrier film of the evaluation laminate obtained in (1-1) above, a 41-stage exposure meter was configured, and exposure was performed using a direct imaging exposure device "DXP-3512" (manufactured by ORC Corporation) with an ultra-high pressure mercury lamp as the light source. The exposure pattern used a grid pattern of squares (the length of one side: the distance between the centers of the squares = 1:2).

[0382] After exposure, the mixture was left at room temperature for 30 minutes, and then the unexposed areas of the photosensitive resin composition were spray-developed with a 1% sodium carbonate aqueous solution at 30°C for 60 seconds. After development, the exposure energy with a gloss retention stage number of 8.0 on a 41-stage exposure meter was used as the sensitivity of the photosensitive resin film (unit: mJ / cm). 2 Using the pattern exposed at this sensitivity, the aperture resolution set on the photosensitive resin film is evaluated according to the following evaluation criteria.

[0383] (1-3) Evaluation of via resolution

[0384] In the evaluation of via resolution, after exposure at an exposure energy of 8.0 (the sensitivity of the photosensitive resin film measured in (1-2) above), spray development was performed, and the via pattern was observed using an optical microscope. The evaluation was then conducted according to the following criteria. The term "opening" refers to the condition where the copper foil of the printed circuit board substrate can be confirmed when observing the via portion of the dot pattern using an optical microscope. A rating of "A" indicates good performance.

[0385] A: The φ60μm through-hole in the dot pattern is now open.

[0386] B: The φ60μm through-hole portion of the dot pattern is not open.

[0387] C: Not photocured.

[0388] [2. Evaluation of the adhesion strength (peel strength) to copper plating]

[0389] The protective film was peeled off from the "photosensitive resin film with a carrier film and a protective film bonded together" manufactured in the various embodiments and comparative examples, and the laminate was obtained by using a pressure vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name "MVLP-500") on a copper-clad laminate substrate with a thickness of 1.0 mm under the conditions of a pressing pressure of 0.4 MPa, a pressing hot plate temperature of 80°C, a vacuum time of 25 seconds, a lamination pressing time of 25 seconds, and an air pressure of less than or equal to 4 kPa.

[0390] The obtained laminate was subjected to a parallel light exposure machine (manufactured by ORC Corporation, trade name "EXM-1201") with an ultra-high pressure mercury lamp as the light source at 500 mJ / cm². 2 Perform full-area exposure. Then, use a UV exposure device at 2000 mJ / cm². 2 Expose the material to the specified exposure level and heat it at 170°C for 1 hour to obtain an evaluation laminate with a cured material (cured film) formed on a copper-clad laminate substrate.

[0391] Next, an aqueous solution containing 200 ml / L diethylene glycol monobutyl ether and 5 g / L sodium hydroxide was prepared as a swelling solution, and the evaluation laminate was immersed in this swelling solution heated to 70°C for 10 minutes. Next, an aqueous solution containing 60 g / L potassium permanganate and 40 g / L sodium hydroxide was prepared as a roughening solution, and the evaluation laminate was immersed in this roughening solution heated to 70°C for 15 minutes. Next, a neutralizing solution (an aqueous solution of 30 g / L tin chloride (SnCl2) and 300 ml / L hydrogen chloride) was prepared, and the evaluation laminate was immersed in this neutralizing solution heated to 40°C for 5 minutes to reduce the potassium permanganate. The surface of the cured evaluation laminate was then treated to remove adhesive residue as described above.

[0392] Next, the surface of the cured evaluation laminate after degumming treatment was cleaned with a 60°C alkaline cleaning agent, "Cleaner Securiganth 902" (manufactured by Atotech Japan Co., Ltd., trade name), for 5 minutes to degrease. After cleaning, the cured laminate was treated with a 23°C pre-dip solution, "pre-dip Neoganth B" (manufactured by Atotech Japan Co., Ltd., trade name), for 1 minute. Then, the cured laminate was treated with a 35°C activator solution, "Activator Neoganth 834" (manufactured by Atotech Japan Co., Ltd., trade name), for 5 minutes, followed by a 30°C reducing solution, "Reducer Neoganth WA" (manufactured by Atotech Japan Co., Ltd., trade name), for 5 minutes.

[0393] The evaluation laminate obtained through the above method was placed in a chemical copper bath ("Basic Printganth MSK-DK", "Copper Printganth MSK", "Stabilizer Printganth MSK" (all manufactured by Atotech Japan Co., Ltd., trade names)) and electroless plating was performed until the plating thickness reached approximately 0.5 μm. After this electroless plating, an annealing treatment was performed at 120°C for 30 minutes to remove residual hydrogen. Then, copper sulfate electroplating was performed, followed by an annealing treatment at 180°C for 60 minutes to form a conductor layer with a thickness of 25 μm.

[0394] For the evaluation laminate in which the conductor layer is formed by the above method, the vertical peel strength is measured at 23°C according to JIS C6481 (1996), and then evaluated according to the following evaluation criteria.

[0395] A: The bonding strength with copper plating is greater than or equal to 0.40 kN / m.

[0396] B: The bonding strength with copper plating is greater than or equal to 0.30 kN / m and less than 0.40 kN / m.

[0397] C: The adhesion strength to copper plating is less than 0.30 kN / m.

[0398] [3. Determination of surface roughness (arithmetic mean roughness: Ra)]

[0399] The substrate is prepared using the same method as the substrate for peel strength measurement in [2. Evaluation of adhesion strength (peel strength) to copper plating], and the same method is used until the adhesive residue is removed, thereby preparing an evaluation substrate for surface roughness measurement.

[0400] The surface roughness (arithmetic mean roughness: Ra) of the insulation layer was measured using a non-contact surface roughness meter, "Contour GT-K" (manufactured by Bruker), with an external lens magnification of 50x and an internal lens magnification of 1x. The average value of 5 points was taken as Ra, and then evaluated according to the following evaluation criteria.

[0401] A: Ra is less than 150nm.

[0402] B: Ra is greater than or equal to 150nm and less than 300nm.

[0403] C: Ra is greater than or equal to 300 nm.

[0404] [4. Evaluation of HAST resistance (electrical insulation reliability after moisture absorption)]

[0405] In the above [2. Evaluation of adhesion strength (peel strength) to copper plating], a conductor layer with a thickness of 35 μm was formed instead of a conductor layer with a thickness of 25 μm. Otherwise, the same operation was performed to obtain a laminate with a conductor layer formed.

[0406] The formed conductor layer was etched to form a circular electrode with a diameter (φ) of 6 mm. Next, a photosensitive solder resist film “FZ-2700GA” (manufactured by Showa Denko Materials Co., Ltd., trade name) was laminated onto the electrode and the cured film using a vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name “MVLP-500”) under the following conditions: lamination pressure 0.4 MPa, hot plate temperature 80°C, vacuum time 25 seconds, lamination time 40 seconds, and pressure less than or equal to 4 kPa. This yielded an evaluation laminate. The thickness of the photosensitive solder resist film layer in the evaluation laminate was 25 μm.

[0407] For the evaluation laminate obtained by the above method, a parallel light exposure machine (manufactured by ORC Corporation, trade name "EXM-1201") with an ultra-high pressure mercury lamp as the light source was used at 500 mJ / cm². 2 Perform full-area exposure. Then, use a UV exposure device at 2000 mJ / cm². 2 Expose the film to the specified exposure level, then heat it at 160°C for 1 hour to obtain a cured film.

[0408] Next, wiring was performed with the circular electrode as the positive electrode and the copper foil on the side of the copper-clad laminate with the circular electrode as the negative electrode. The substrate was then exposed to a pressure cooker (model name "Unsaturated Type Ultra-Accelerated Life Test Apparatus PC-422RP", manufactured by Hirayama Corporation) at 135°C, 85% ppm, and 5.5V for 200 hours. The resistance between the electrodes was measured, and then an evaluation was performed according to the following evaluation criteria.

[0409] A: The resistance value after 200 hours is greater than or equal to 10 × 10⁻⁶. 7 Ω.

[0410] B: The resistance value after 200 hours is greater than or equal to 10 × 10 6 Ω and less than 10 × 10 7 Ω.

[0411] C: The resistance value after 200 hours is less than 10 × 10 6 Ω.

[0412] [5. Evaluation of crack resistance]

[0413] (5-1) Evaluation of the fabrication of laminated bodies

[0414] The surface of the copper foil on a printed circuit board substrate (manufactured by Showa Denko Materials Co., Ltd., trade name "MCL-E-679"), which is made by laminating 12μm thick copper foil onto a glass epoxy material, was ground with an abrasive brush, washed with water, and dried to obtain a roughened printed circuit board substrate. Next, the protective film was peeled off from the "photosensitive resin film with a carrier film and a protective film bonded" manufactured in the various embodiments and comparative examples. The exposed photosensitive resin film was placed in contact with the copper foil of the roughened printed circuit board substrate, and then lamination was performed using a pressure-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name "MVLP-500"). It should be noted that the lamination conditions were set as follows: hot plate temperature 70°C, vacuum time 20 seconds, lamination pressing time 30 seconds, air pressure less than or equal to 4 kPa, and pressing pressure 0.4 MPa. After lamination, the substrate is left at room temperature for 1 hour or more to obtain an evaluation laminate in which a photosensitive resin film and a carrier film are sequentially laminated on the copper foil surface of a printed wiring board substrate.

[0415] (5-2) Sensitivity determination of photosensitive resin films

[0416] The test piece obtained by using the carrier membrane of the evaluation laminate obtained above and performing the same treatment as described in (1-2) above was exposed to the atmosphere at -65°C for 15 minutes, then heated at a heating rate of 180°C / min, then exposed to the atmosphere at 150°C for 15 minutes, and then cooled at a cooling rate of 180°C / min. This thermal cycle was repeated 1,000 times.

[0417] Then, for the evaluation laminate, 10 random locations of the opening of a 2mm square through-hole were observed using a metal microscope with a magnification of 100x, and the degree of cracking and peeling was evaluated according to the following evaluation criteria.

[0418] A: No cracks or spalling were observed.

[0419] B: Cracks and spalling were observed in 1 or 2 out of 10 locations.

[0420] C: Cracks and spalling were observed in 3 out of 10 locations.

[0421] D: Cracks and spalling were observed at 4 or more out of 10 locations.

[0422] <Synthetic Example 1> Synthesis of acid-modified epoxy derivative 1 [(A1) component] containing vinyl unsaturated groups and an alicyclic skeleton

[0423] Dicyclopentadiene-type epoxy resin ("XD-1000" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 252 g / eq, softening point 74.2℃, belonging to component (a1), represented by the above general formula (a1-1). Alicyclic skeleton with 10 carbon atoms in the ring-forming carbon group) 350 parts by mass, acrylic acid (belonging to component (a2)) 70 parts by mass, methyl hydroquinone 0.5 parts by mass, carbitol acetate 120 parts by mass, heated to 90℃ and stirred to carry out the reaction and dissolve the mixture.

[0424] Next, the obtained solution was cooled to 60°C, 2 parts by mass of triphenylphosphine were added, and the mixture was heated to 100°C to carry out the reaction until the acid value of the solution became 1 mg KOH / g. 98 parts by mass of tetrahydrophthalic anhydride (belonging to component (a3)) and 85 parts by mass of carbitol acetate were added to the reacted solution, and the mixture was heated to 80°C and then reacted for 6 hours.

[0425] Then, cooling to room temperature yields an acid-modified dicyclopentadiene-type epoxy acrylate with a solid content concentration of 73% by mass (belonging to components (A1) and (A1-1). Hereinafter referred to as "acid-modified epoxy derivative 1 containing vinyl unsaturated groups and an alicyclic skeleton").

[0426] <Examples 1-5, Comparative Example 1>

[0427] (Preparation of photosensitive resin composition)

[0428] The compositions were formulated according to the formulation and proportions shown in Table 1, and then kneaded using a three-roll mill to prepare the photosensitive resin compositions. In each example, carbitol acetate was appropriately added to adjust the concentration, thereby obtaining a photosensitive resin composition with a solid content of 60% by mass.

[0429] (Preparation of photosensitive resin film)

[0430] A 25 μm thick polyethylene terephthalate film (G2-25, manufactured by Teijin Corporation, trade name) was used as a carrier film. The photosensitive resin composition prepared in each example was coated onto this carrier film, and then dried at 100°C for 10 minutes using a hot air convection dryer to form a 25 μm thick photosensitive resin film (photosensitive layer). Next, a biaxially oriented polypropylene film (MA-411, manufactured by Oji F-Tex Corporation, trade name) was laminated as a protective film onto the surface of the photosensitive resin film (photosensitive layer) opposite to the side in contact with the carrier film, thereby producing a photosensitive resin film with both a carrier film and a protective film laminated.

[0431] The prepared photosensitive resin film was used for various evaluations according to the methods described above. The results are shown in Table 1.

[0432] [Table 1]

[0433]

[0434] • The unit for the proportions of the above components is parts by mass. It should be noted that, in the case of a solution, these are conversions of solid components.

[0435] The ingredients used in each example are described below.

[0436] (A)Ingredients:

[0437] • Acid-modified epoxy derivative 1 containing ethylene unsaturated groups and an alicyclic skeleton [(A1) component]: The substance obtained in Synthesis Example 1 was used.

[0438] • Dipentaerythritol pentaacrylate [(Aiii) component]

[0439] (X) component:

[0440] • Core-shell particle 1: (Core: styrene-butadiene copolymer, shell: acrylate copolymer) (Average primary particle size: 0.1 μm)

[0441] • Core-shell particles 2: (Core: acrylate copolymer, Shell: epoxy resin) (Average primary particle size: 0.1 μm)

[0442] Here, the average (volume average) of the primary particle size of core-shell particles 1 and 2 is set as the particle size at 50% (volume basis) of the cumulative value of the particle size distribution obtained by measuring particles dispersed in a solvent using a Zeta potential-particle size distribution measuring device (Beckman-Coultre), according to international standard specification ISO 13321 and with a refractive index of 1.38.

[0443] (B) Ingredients:

[0444] Photopolymerization initiator 1: 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, acetophenone compound

[0445] Photopolymerization initiator 2: 2,4-Diethylthioxanthone, thioxanthone compound

[0446] (C) Ingredients:

[0447] • Biphenyl-type epoxy resin: "YX-4000" (manufactured by Mitsubishi Chemical Corporation, trade name)

[0448] • Epoxy-modified polybutadiene: "Epolead (registered trademark) PB3600" (manufactured by Daicel Co., Ltd., trade name)

[0449] (D) Ingredients:

[0450] • Polyester-based elastomer: "Espel (registered trademark) 1108" (manufactured by Showa Denko Materials Co., Ltd., trade name)

[0451] (E) Components:

[0452] • Silica: “SFP-20M” (manufactured by Denka Co., Ltd., average particle size 0.3μm, trade name)

[0453] According to Table 1, in Examples 1-5, the through-hole resolution, adhesion strength to copper plating, electrical insulation reliability, and crack resistance are excellent, and the surface roughness Ra is reduced. It should be noted that because the interlayer insulating layer containing the photosensitive resin composition has a low surface roughness Ra, fine surface shapes can be formed on the surface of this interlayer insulating layer, making it easier to form fine wiring. Furthermore, it is noteworthy that despite the low surface roughness Ra, the adhesion strength to copper plating is high.

[0454] On the other hand, in Comparative Example 1, which does not contain (X) component, the result is that although the through-hole resolution is good, the adhesion strength to copper plating, electrical insulation reliability and crack resistance are insufficient, and the surface roughness Ra increases.

[0455] Symbol Explanation

[0456] 100A: Multilayer printed wiring board, 102: Circuit pattern, 103: Interlayer insulation layer, 104: Through hole (conductive via), 105: Seed layer, 106: Resist pattern, 107: Copper circuit layer, 108: Solder resist layer.

Claims

1. A photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylene unsaturated group, (X) organic particles, (B) a photopolymerization initiator, and (C) a thermosetting resin. The photopolymerizable compound (A) having an vinyl unsaturated group includes (A1) photopolymerizable compounds having an vinyl unsaturated group, an acidic substituent, and an alicyclic skeleton. The organic particle (X) contains a core-shell particle. The combination of the components constituting the core and the components constituting the shell of the core-shell particles (core / shell) is a styrene-butadiene copolymer / (meth)acrylate copolymer. The thermosetting resin (C) comprises an epoxy resin, wherein the epoxy resin comprises a biphenyl-type epoxy resin.

2. The photosensitive resin composition according to claim 1, wherein the (A) photopolymerizable compound having an vinyl unsaturated group further comprises at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable vinyl unsaturated group, (Aii) a difunctional vinyl monomer having two polymerizable vinyl unsaturated groups, and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable vinyl unsaturated groups.

3. The photosensitive resin composition according to claim 1, wherein in the photopolymerizable compound having an ethylene unsaturated group, an acidic substituent, and an alicyclic skeleton in (A1), the alicyclic skeleton is an alicyclic skeleton with 5 to 20 cyclic carbon atoms.

4. The photosensitive resin composition according to claim 1, wherein in the photopolymerizable compound having simultaneously an ethylene unsaturated group, an acidic substituent, and an alicyclic skeleton in (A1), the alicyclic skeleton comprises two or more rings.

5. The photosensitive resin composition according to claim 1, further comprising (D) an elastomer.

6. The photosensitive resin composition according to claim 5, wherein the (D) elastomer comprises at least one selected from the group consisting of styrene-based elastomers, olefin-based elastomers, polyester-based elastomers, urethane-based elastomers, polyamide-based elastomers, acrylic elastomers, and silicone-based elastomers.

7. The photosensitive resin composition according to claim 1, further comprising (F) an inorganic filler.

8. A photosensitive resin composition for forming light-permeable holes, comprising the photosensitive resin composition according to any one of claims 1 to 7.

9. A photosensitive resin composition for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 7.

10. A photosensitive resin film comprising the photosensitive resin composition according to any one of claims 1 to 7.

11. A photosensitive resin film for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 7.

12. A multilayer printed wiring board comprising an interlayer insulating layer, said interlayer insulating layer being formed using the photosensitive resin composition according to any one of claims 1 to 7.

13. A multilayer printed wiring board comprising an interlayer insulating layer, said interlayer insulating layer being formed using the photosensitive resin film of claim 10.

14. A semiconductor package comprising: the multilayer printed circuit board of claim 12, and a semiconductor element.

15. A method for manufacturing a multilayer printed circuit board, comprising the following (1) to (4), (1): The photosensitive resin film of claim 10 is laminated onto one or both sides of the circuit substrate; (2): Expose and develop the laminated photosensitive resin film in (1) to form an interlayer insulating layer with through holes; (3): Roughen the through hole and the interlayer insulating layer; (4): A circuit pattern is formed on the interlayer insulating layer.

Images