TWI875814B - Laminated structure - Google Patents

Abstract

The present invention provides a laminated structure having a support body and a curable resin layer. In the build-up process of the printed circuit board, since the cured curable resin layer has excellent adhesion to the support body without compromising the yield, a printed circuit board with excellent surface smoothness can be produced. After the curable resin layer is cured, a 90° peel test is performed. The peel strength between the support body and the curable resin layer ranges from 0.03 N/cm to 0.20 N/cm. In addition, when the curable resin layer is peeled from the support body after curing, the maximum valley depth (Sv) of the peeled surface of the curable resin layer is 500 nm or less, or the maximum peak height (Sp) of the peeled surface of the curable resin layer is 500 nm or less.

Description

Layered structure

The present invention relates to a laminate structure, and more specifically, to a laminate structure having a support and a peelable curable resin layer formed on the support.

As a method for manufacturing multi-layer printed circuit boards, a method for manufacturing printed circuit boards by a build-up process in which insulating layers and conductive layers are alternately stacked is widely used. In the manufacturing method by the build-up method, generally speaking, the insulating layer is formed by thermally curing a curable resin composition to form a curable resin layer. In recent years, in multi-layer printed circuit boards, multiple layers of stacking layers formed by the build-up process are provided to seek further miniaturization and high density of wiring. As an example of miniaturization, there is a step of laminating a curable resin layer with a support body on a substrate, thermally curing the curable resin layer, and then peeling off the support body. In this step, if a curable resin composition with a high amount of inorganic filler is used, there is a problem that the peel strength of the formed insulating layer and the conductive layer is reduced. Therefore, Patent Document 1 proposes the use of a support body that exhibits specific expansion characteristics when heated. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2015-162635

[The problem that the invention wants to solve]

However, it was found that when the support is cured with a support, the shrinkage behavior of the support is very different from that of the curable resin layer, and stress is generated between the support and the curable resin layer, which may cause the support to peel off during the process. In other words, if peeling occurs during the process, excess energy will be directly irradiated to the curable resin during the laser processing process, and the pattern formation will be significantly worse than that of the support, resulting in a lower yield. On the other hand, it was found that if the adhesion between the support and the curable resin layer is improved to solve this problem, a part of the curable resin layer will remain on the side of the support during peeling, and the peeling surface of the curable resin layer will lose its smoothness, which will also have an adverse effect on the smoothness of the copper wiring formed by the semi-additive process. Therefore, the purpose of the present invention is to provide a laminated structure, which can achieve a printed circuit board with excellent surface smoothness in the build-up process of a printed circuit board without affecting the yield due to the excellent adhesion between the cured curable resin layer and the support. [Means for solving the problem]

The inventors have found that the above-mentioned problems can be solved by using the following laminated structure, thereby completing the present invention: a laminated structure having a support and a curable resin layer, wherein after the curable resin layer is cured, the peel strength between the support and the curable resin layer is greater than 0.03 N/cm and less than 0.20 N/cm in a 90-degree peel test; when the support is peeled off, the average maximum valley depth Sv on the peeling surface of the curable resin layer is less than 500 nm or the maximum peak height Sp is less than 500 nm.

That is, the laminate structure of the first embodiment of the present invention has a support body and a curable resin layer, and its characteristics are that, after the curable resin layer is cured, the peeling strength between the support body and the curable resin layer is greater than 0.03N/cm and less than 0.20N/cm in a 90-degree peeling test, and when the curable resin layer is peeled off from the support body after being cured, the maximum valley depth Sv of the peeling surface of the curable resin layer is less than 500nm.

Furthermore, the second embodiment of the laminate structure of the present invention has a support body and a curable resin layer, and is characterized in that, after the curable resin layer is cured, the peel strength between the support body and the curable resin layer is greater than 0.03N/cm and less than 0.20N/cm in a 90-degree peeling test, and, when the curable resin layer is peeled off from the support body after being cured, the maximum peak height Sp of the peeling surface of the curable resin layer is less than 500nm.

In the first aspect of the present invention, when the curable resin layer is peeled off from the support after being cured, the maximum peak height Sp of the peeled surface of the curable resin layer is preferably less than 500 nm.

In the first and second aspects of the present invention, when the curable resin layer is peeled off the support body after curing, the maximum peak height Sp of the peeling surface of the support body is preferably less than 500nm. [Effect of the invention]

According to the present invention, a laminate structure can be provided, which can achieve a printed circuit board with excellent surface smoothness in the build-up process of a printed circuit board without sacrificing yield due to the excellent adhesion between the cured curable resin layer and the support body after curing.

The following is a detailed description of the embodiments of the present invention. In addition, unless otherwise specified, in this specification, a numerical range represented by the symbol "~" means a range including the numerical values of the upper and lower limits (that is, a range above the lower limit and below the upper limit).

[Laminated structure] The laminated structure of the present invention is a laminated structure having a support and a curable resin layer. After the curable resin layer is cured, the peel strength between the support and the curable resin layer is 0.03 N/cm to 0.20 N/cm in a 90-degree peel test. It was found that by making the peel strength within this range, it has peeling resistance in the step, and when the support is peeled off after the step is completed, it can be peeled off without excessively applying a load to the surface of the cured resin. The peel strength is 0.03N/cm to 0.20N/cm, preferably 0.04N/cm to 0.18N/cm, and more preferably 0.05N/cm to 0.15N/cm. As a method for adjusting the peel strength, for example, changing the type of release agent of the support or changing the film thickness of the release agent can be cited. In addition, in the present invention, the peel strength is the strength when a support with a width of 10mm is stretched at an angle of 90 degrees at a speed of 50mm/min.

In the present invention, whether the curable resin layer is cured is judged by placing a fabric containing isopropyl alcohol (IPA) on the surface of the curable resin layer in an environment of 25°C and 50% RH, and then placing a load of 500 g on it. After standing for 1 minute, the fabric is peeled off, and the state where the curable resin layer is not attached to all or part of the surface of the fabric in contact with the curable resin layer is judged to be a cured state.

In the laminated structure of the present invention, when the curable resin layer is peeled off from the support body after being cured, the maximum valley depth Sv of the peeled surface of the curable resin layer is less than 500nm. When the maximum valley depth Sv of the peeled surface of the curable resin layer is less than 500nm, a conductor layer can be formed on the curable resin layer with a high yield. The maximum valley depth Sv of the peeled surface of the curable resin layer is preferably less than 400nm, more preferably less than 350nm, and even more preferably less than 300nm. When the maximum valley depth Sv of the peeled surface of the curable resin layer exceeds 500nm, the surface of the conductor layer of the copper wiring, etc., becomes uneven and produces deep recessed parts. This part becomes difficult to peel off when using a stripping liquid to strip the photoresist coated on the conductor layer, resulting in a significant decrease in yield. In addition, in the present invention, the value of the maximum valley depth Sv is measured using a non-contact surface roughness meter, using the VSI contact mode and a 50x lens.

In the laminated structure of the present invention, when the curable resin layer is peeled off from the support after curing, the maximum peak height Sp of the peeled surface of the curable resin layer is less than 500nm. When the maximum peak height Sp of the peeled surface of the curable resin layer is less than 500nm, a conductive layer can be formed on the curable resin layer with a high yield. The maximum peak height Sp of the peeled surface of the curable resin layer is preferably less than 400nm, more preferably less than 350nm, and even more preferably less than 300nm. When the value of the above-mentioned maximum peak height Sp exceeds 500nm, the surface of the conductive layer of the copper wiring, etc., becomes uneven and produces deep recessed parts. This part has a reduced resolution in the subsequent photolithography step (photopatterning step) of the photoresist coating formed on the conductor layer, especially in fine patterns with line & spacing less than 5μm/5μm, resulting in a significant deterioration in yield. In addition, in the present invention, the value of the maximum peak height Sp is measured using a non-contact surface roughness meter, using the VSI contact mode and a 50x lens.

As a specific measurement method for the maximum valley depth Sv and the maximum peak height Sp in the present invention, the sample to be measured is placed on the X-Y stage, the software (Vision 64) is started, and the measurement mode VSI is selected. Then, in the live video mode, the focus and brightness are roughly adjusted with a 10x objective lens. Then, the intensity is adjusted. Then, the XY controller is used to move the measurement point to the bottom of the objective lens. Use the Z-axis controller to gradually approach the sample. Manipulate the Z-axis until the best focus is found, then replace it with a 50x objective lens, adjust the focus to the best position again, and adjust the Tip Tilt as needed to less than 15 fringes. Finally, click the Measurement or Single Acquisition button on the software to start the measurement. As the measurement conditions, the evaluation length is 0.3 mm and the evaluation point is 10 points at equal intervals from the center of the sample of the peeled support to the outside in the peel strength evaluation. The values of Sp and Sv are measured respectively, and the average is used as the maximum peak height Sp and maximum valley depth Sv of the peeled surface of the curable resin layer in the present invention. In addition, the maximum peak height Sp of the peeled surface of the support is also measured in the same way as the maximum peak height Sp of the peeled surface of the curable resin layer after the support is peeled. The measurement conditions are also for an evaluation length of 0.3 mm and the evaluation points are 10 equally spaced points from the center of the peeled support body used in the peeling strength evaluation toward the outside, and the values of Sp are measured separately, and the average thereof is taken as the maximum peak height Sp of the peeling surface of the support body in the present invention.

In the laminated structure of the present invention, when the curable resin layer is peeled off from the support body after being cured, it is particularly preferred that the maximum valley depth Sv and the maximum peak height Sp of the peeling surface of the curable resin layer both meet the above numerical ranges.

[Curing resin layer] Next, the components of the curable resin composition (hereinafter also referred to as the composition) forming the curable resin layer of the present invention are described. In addition, in this specification, (meth)acrylate is a term that collectively refers to acrylate, methacrylate and a mixture thereof, and other similar expressions are the same.

[Curing resin] The curing resin composition contains at least a curing resin. As the curing resin, either a thermosetting resin that cures by heating or a photocuring resin that cures by active light can be used.

[Thermosetting resin] Thermosetting resin is a resin that has a functional group that can be cured by heat. Thermosetting resin is preferred because it can be cured efficiently even when it contains a large amount of inorganic fillers that are difficult for active light to penetrate.

Thermosetting resins are not particularly limited, and epoxy compounds, oxycyclobutane compounds, compounds having two or more sulfide groups in the molecule, i.e., episulfide resins, melamine resins, benzoguanidine resins, melamine derivatives, amino resins of benzoguanidine derivatives, etc., blocked isocyanate compounds, cyclocarbonate compounds, dimaleimide, carbodiimide, etc. can be used. These compounds can also be used in combination.

The epoxide is a compound having an epoxide group, and any conventionally known epoxide may be used, including a bifunctional epoxide having two epoxide groups in the molecule, a polyfunctional epoxide having a plurality of epoxide groups in the molecule, etc. In addition, a hydrogenated bifunctional epoxide may also be used.

As the epoxy, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin can be used. Epoxy resins, dicyclopentadiene epoxy resins, triphenylmethane epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, phosphorus-containing epoxy resins, anthracene epoxy resins, norbornene epoxy resins, adamantanene epoxy resins, fluorene epoxy resins, aminophenol epoxy resins, aminocresol epoxy resins, alkylphenol epoxy resins, etc. These epoxy resins may be used alone or in combination of two or more.

The epoxy may be any of a solid epoxy resin, a semi-solid epoxy resin and a liquid epoxy resin. Here, in this specification, a solid epoxy resin refers to an epoxy resin that is solid at 40°C, a semi-solid epoxy resin refers to an epoxy resin that is solid at 20°C and liquid at 40°C, and a liquid epoxy resin refers to an epoxy resin that is liquid at 20°C.

Examples of solid epoxy resins include naphthalene-based epoxy resins such as HP-4700 (naphthalene-based epoxy resin) manufactured by DIC Corporation, EXA4700 (quadrifunctional naphthalene-based epoxy resin) manufactured by DIC Corporation, and NC-7000 (polyfunctional solid epoxy resin containing a naphthalene skeleton) manufactured by Nippon Kayaku Co., Ltd.; epoxides of condensates of phenols and aromatic aldehydes having a phenolic hydroxyl group such as EPPN-502H (triphenylphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd. (triphenylphenol-based epoxy resin); and Epiclon manufactured by DIC Corporation. HP-7200H (polyfunctional solid epoxy resin containing a dicyclopentadiene skeleton) and other dicyclopentadiene aralkyl type epoxy resins; NC-3000H (polyfunctional solid epoxy resin containing a biphenyl skeleton) and other biphenyl aralkyl type epoxy resins manufactured by Nippon Kayaku Co., Ltd.; NC-3000L and other biphenyl/phenol novolac type epoxy resins manufactured by Nippon Kayaku Co., Ltd.; Epiclon N660, Epiclon N690 manufactured by DIC Corporation, EOCN-104S manufactured by Nippon Kayaku Co., Ltd. and other novolac type epoxy resins; YX-4000 and other biphenyl type epoxy resins manufactured by Mitsubishi Chemical Co., Ltd.; NIPPON STEEL Chemical & Material Co., Ltd. Ltd.'s TX0712 and other phosphorus-containing epoxy resins; Nissan Chemical Co., Ltd.'s TEPIC and other 2,3-epoxypropyl isocyanate.

Examples of the semi-solid epoxy resin include bisphenol A type epoxy resins such as Epiclon 860, Epiclon 900-IM, Epiclon EXA-4816, and Epiclon EXA-4822 manufactured by DIC Corporation, EPOTOHTOYD-134 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., jER834 and jER872 manufactured by Mitsubishi Chemical Co., Ltd., and ELA-134 manufactured by Sumitomo Chemical Industries, Ltd.; naphthalene type epoxy resins such as Epiclon HP-4032 manufactured by DIC Corporation; and phenol novolac type epoxy resins such as Epiclon N-740 manufactured by DIC Corporation.

Examples of the liquid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolac type epoxy resin, tertiary butyl-catechol type epoxy resin, glycidylamine type epoxy resin, aminophenol type epoxy resin, and alicyclic epoxy resin.

Next, as the cyclooxanyl compound, there can be listed: bis[(3-methyl-3-cyclooxanylmethoxy)methyl]ether, bis[(3-ethyl-3-cyclooxanylmethoxy)methyl]ether, 1,4-bis[(3-methyl-3-cyclooxanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-cyclooxanylmethoxy)methyl]benzene, (3-methyl-3-cyclooxanyl)methyl acrylate, (3-ethyl-3-cyclooxanyl)methyl acrylate, methacrylic acid Examples of polyfunctional cyclohexanes include (3-methyl-3-cyclohexanyl)methyl ester, (3-ethyl-3-cyclohexanyl)methyl methacrylate, and oligomers or copolymers thereof. Examples of polyfunctional cyclohexanols include cyclohexanols and novolac resins, poly(p-hydroxystyrene), cardo-type bisphenols, calixarene, calixresorcinarene, or ethers of resins having hydroxyl groups such as silsesquioxane. Examples of polyfunctional cyclohexanols include copolymers of unsaturated monomers having cyclohexanol rings and (meth)acrylic acid alkyl esters.

Examples of the cyclosulfide resin include bisphenol A type cyclosulfide resins, etc. In addition, cyclosulfide resins obtained by replacing the oxygen atom of the epoxide group of an epoxy resin with a sulfur atom by the same synthesis method can also be used.

In the present invention, epoxide is preferably used as a thermosetting resin. Furthermore, from the viewpoint of obtaining a cured product having a high glass transition temperature (Tg) and excellent crack resistance, at least any one of a solid epoxy resin and a semi-solid epoxy resin is preferred. As an epoxide, from the viewpoint of better physical properties of the cured product, an aromatic epoxy resin is preferred, among which naphthalene-type epoxide and biphenyl-type epoxide are more preferred. In addition, in the present specification, an aromatic epoxy resin means an epoxy resin having an aromatic ring skeleton in its molecule.

Thermosetting resins may be used alone or in combination of two or more. When two or more thermosetting resins are used in combination, the total amount of the semi-solid epoxy and the solid epoxy, calculated as solid content, is preferably 10 to 55% by mass, more preferably 15 to 50% by mass, and even more preferably 20 to 45% by mass based on the total amount of the composition. In addition, the amount of the liquid epoxy resin blended is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, calculated as solid content, based on the total amount of the composition, from the viewpoint of not excessively lowering the glass transition temperature (Tg) of the cured product.

[Photocurable resin] As a photocurable resin, any resin that cures by irradiation with active light may be used, and preferably a compound having one or more ethylenically unsaturated bonds in the molecule is used. As a compound having ethylenically unsaturated bonds, photopolymerizable oligomers of conventionally used photosensitive monomers, photopolymerizable vinyl monomers, etc. can be used. In addition, as a photocurable resin, a polymer such as a carboxyl-containing resin having ethylenically unsaturated bonds can be used.

As the photosensitive monomer, a photosensitive (meth)acrylate compound having one or more (meth)acryloyl groups in the molecule and being liquid, solid or semi-solid at room temperature can be used. The photosensitive (meth)acrylate compound being liquid at room temperature not only serves the purpose of improving the photoreactivity of the composition, but also plays a role in adjusting the viscosity of the composition to be suitable for various coating methods or facilitating solubility in alkaline aqueous solutions.

Examples of the photosensitive (meth)acrylate compound include hydroxyl-containing acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, pentaerythritol triacrylate, and dipentaerythritol pentaacrylate; water-soluble acrylates such as polyethylene glycol diacrylate and polypropylene glycol diacrylate; acrylates of polyfunctional alcohols such as trihydroxymethylpropane triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate; polyfunctional alcohols such as trihydroxymethylpropane and hydrogenated bisphenol A; Or acrylates of ethylene oxide adducts and propylene oxide adducts of multifunctional phenols such as bisphenol A and biphenol; multifunctional or monofunctional polyurethane acrylates of isocyanate modified products of the above-mentioned hydroxyl-containing acrylates; epoxy acrylates of (meth) acrylic acid adducts of bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether or phenol novolac epoxy resin, and methacrylates corresponding to the above-mentioned acrylates, etc. These compounds can be used alone or in combination of two or more. Among these compounds, a multifunctional (meth) acrylate compound having two or more (meth) acryloyl groups in one molecule is preferred.

Specific examples of carboxyl group-containing resins include the following compounds (which may be either oligomers or polymers).

(1) Carboxyl-containing resins obtained by copolymerization of unsaturated carboxylic acids such as (meth)acrylic acid with unsaturated group-containing compounds such as styrene, α-methylstyrene, lower (meth)acrylic acid alkyl esters, isobutylene, etc.

(2) Carboxyl-containing urethane resins obtained by addition polymerization of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, and diol compounds containing carboxyl groups such as dihydroxymethylpropionic acid and dihydroxymethylbutyric acid, and diol compounds such as polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A-based epoxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

(3) A carboxyl-containing photosensitive urethane resin obtained by the addition polymerization reaction of a diisocyanate with a (meth)acrylate of a bifunctional epoxy resin such as bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bixylenol epoxy resin, diphenol epoxy resin or a partially anhydride-modified product thereof, a carboxyl-containing diol compound and a diol compound.

(4) A carboxyl-containing photosensitive urethane resin is prepared by adding a compound having one hydroxyl group and one or more (meth)acryl groups in the molecule, such as a hydroxyalkyl (meth)acrylate, to the synthesis of the resin of (2) or (3) to perform terminal (meth)acrylation.

(5) A carboxyl-containing photosensitive urethane resin is prepared by adding an equimolar reaction product of isophorone diisocyanate and pentaerythritol triacrylate or the like, wherein the compound has one isocyanate group and one or more (meth)acryl groups in the molecule, to the synthesis of the resin of (2) or (3), thereby subjecting the terminal of the compound to (meth)acrylation.

(6) A carboxyl-containing photosensitive resin is prepared by reacting (meth)acrylic acid with a difunctional or higher polyfunctional (solid) epoxy resin to add a diprotic anhydride to a hydroxyl group present in a side chain.

(7) A polyfunctional epoxy resin obtained by epoxidizing the hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin is reacted with (meth)acrylic acid to add a diprotic anhydride to the generated hydroxyl group to produce a carboxyl-containing photosensitive resin.

(8) A dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid is reacted with a bifunctional cyclohexane resin to add a diprotic anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the resulting primary hydroxyl group to produce a carboxyl-containing polyester resin.

(9) A carboxyl-containing photosensitive resin obtained by reacting an epoxide having a plurality of epoxide groups in one molecule with a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule such as p-hydroxyphenethyl alcohol and an unsaturated group-containing monocarboxylic acid such as (meth)acrylic acid, and reacting the alcoholic hydroxyl group of the obtained reaction product with a polyacid anhydride such as maleic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, adipic acid, etc.

(10) A carboxyl group-containing photosensitive resin obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide, reacting the reaction product with an unsaturated group-containing monocarboxylic acid, and reacting a polyacid anhydride with the reaction product.

(11) A carboxyl group-containing photosensitive resin obtained by reacting a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethyl carbonate or propylene carbonate, reacting the reaction product with a monocarboxylic acid containing an unsaturated group, and reacting a polyacid anhydride with the reaction product obtained.

(12) A carboxyl-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth)acryl groups in one molecule to the resins of (1) to (11).

[Curing agent] When a thermosetting resin is used as the curing resin, the curing resin composition may further contain a curing agent. Examples of the curing agent include phenolic resins, polycarboxylic acids and their anhydrides, cyanate resins, and active ester resins.

As the phenolic resin, phenol novolac resin, alkylphenol novolac resin, bisphenol A novolac resin, dicyclopentadiene type phenolic resin, Xylok type phenolic resin, terpene modified phenolic resin, cresol/naphthol resin, polyvinylphenol, phenol/naphthol resin, phenolic resin containing α-naphthol skeleton, cresol novolac resin containing triazine, etc., which are conventionally known, can be used alone or in combination of two or more.

The above-mentioned polycarboxylic acids and their anhydrides are compounds and their anhydrides having two or more carboxyl groups in one molecule, and examples thereof include copolymers of (meth)acrylic acid, copolymers of maleic anhydride, condensates of diprotic acids, etc. In addition, resins having carboxylic acid terminals such as carboxylic acid-terminated amide resins can also be cited.

The cyanate resin is a compound having two or more cyanate groups (-OCN) in one molecule. Any conventionally known cyanate resin may be used. Examples of the cyanate resin include phenol novolac type cyanate resin, alkylphenol novolac type cyanate resin, dicyclopentadiene type cyanate resin, bisphenol A type cyanate resin, bisphenol F type cyanate resin, and bisphenol S type cyanate resin. In addition, a prepolymer partially triazine-treated may be used.

The above-mentioned active ester resin is a resin having two or more active ester groups in one molecule. The active ester resin can generally be obtained by a condensation reaction of a carboxylic acid compound and a hydroxyl compound. Among them, the active ester compound obtained by using a phenol compound or a naphthol compound as the hydroxyl compound is preferred. Examples of the phenolic compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, gambogic acid, benzenetriol, dicyclopentadienyl diphenol, phenol novolac, and the like.

Furthermore, alicyclic olefin polymers can also be used as curing agents. Specific examples of the method for producing alicyclic olefin polymers include: (1) a method of polymerizing an alicyclic olefin having at least one of a carboxyl group and a carboxylic anhydride group (hereinafter referred to as "carboxyl group, etc.") with other monomers as required; (2) a method of hydrogenating the aromatic ring portion of a (co)polymer obtained by polymerizing an aromatic olefin having a carboxyl group, etc. with other monomers as required; (3) a method of copolymerizing an alicyclic olefin not having a carboxyl group, etc. with a monomer having a carboxyl group, etc.; (4) a method of hydrogenating the aromatic ring portion of a copolymer obtained by copolymerizing an aromatic olefin not having a carboxyl group, etc. with a monomer having a carboxyl group, etc.; (5) (6) a method of introducing a compound having a carboxyl group into an alicyclic olefin polymer having no carboxyl group by a modification reaction; or (7) a method of converting the carboxyl ester group of the alicyclic olefin polymer having a carboxyl ester group obtained by the methods of (1) to (5) into a carboxyl group by, for example, hydrolysis.

Among the curing agents, phenolic resins, active ester resins, and cyanate resins are preferred.

In the above curing agent, the functional group such as epoxy group of the thermosetting resin that can undergo a heat curing reaction and the functional group in the curing agent that reacts with the functional group are preferably mixed at a ratio of functional group of the curing agent/functional group that can undergo a heat curing reaction (equivalent ratio) = 0.2~2.0 in terms of solid content conversion. By making the functional group of the curing agent/functional group that can undergo a heat curing reaction (equivalent ratio) within the above range, the coarsening of the surface of the cured film in the desmearing step can be prevented. More preferably, the functional group of the curing agent/functional group that can undergo a heat curing reaction (equivalent ratio) = 0.3~1.0.

[Curing accelerator] When using a thermosetting resin as a curing resin, a curing accelerator may be mixed with the above-mentioned curing agent or alone. The curing accelerator is a component that accelerates the heat curing reaction and is used to further improve the properties such as adhesion, chemical resistance, and heat resistance. Specific examples of such curing accelerators include: imidazole and its derivatives; guanidine derivatives such as ethylguanidine and benzoguanidine; polyamines such as diaminodiphenylmethane, metaphenylenediamine, metaphenylenediamine, diaminodiphenylsulfone, cyanamide, urea, urea derivatives, melamine, polyhydrazides, etc.; at least one of the organic acid salts and epoxy adducts thereof; amine complexes of boron trifluoride; triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-styryl-S-triazine, etc.; trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine; Amines such as amine, pyridine, N-methyl thiophene, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine, and m-aminophenol; polyphenols such as polyvinylphenol, brominated polyvinylphenol, phenol novolac, and alkylphenol novolac; organic phosphines such as tributylphosphine, triphenylphosphine, and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosphonium chloride; benzyltrimethylol chloride Quaternary ammonium salts such as ammonium bis(2-hydroxyphenyl)amine, phenyltributylammonium chloride, etc.; polyacid anhydrides; photocatalytic polymerization catalysts such as diphenyliodonium tetrafluoroborate, triphenylprobium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate, etc.; styrene-maleic anhydride resin; equimolar reactants of phenyl isocyanate and dimethylamine, equimolar reactants of organic polyisocyanates such as methylphenyl diisocyanate and isophorone diisocyanate and dimethylamine, metal catalysts, etc., which are conventionally known curing accelerators. The curing accelerators may be used alone or in combination of two or more.

Although it is not essential to use a curing accelerator, particularly when accelerating curing, it is preferably used in an amount within a range of 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the thermosetting resin, calculated on a solid basis.

[Thermoplastic resin (polymer resin)] In order to improve the mechanical strength of the obtained cured film, a thermoplastic resin can be further mixed with the thermoplastic resin constituting the curable resin layer in the present invention. Examples of the thermoplastic resin include thermoplastic polyhydroxy polyether resins, polyvinyl acetal resins, phenoxy resins, polyamide resins, polyamide-imide resins, block copolymers, etc. Among the thermoplastic resins, thermoplastic polyhydroxy polyether resins, polyvinyl acetal resins, phenoxy resins, and block copolymers having a fluorene skeleton are preferred. The thermoplastic resin can be used alone or in combination of two or more.

Among the above, when the thermoplastic polyhydroxy polyether resin has a fluorene skeleton, it has a high glass transition temperature and excellent heat resistance, so it can maintain the low thermal expansion rate brought by the semi-solid or solid epoxy resin and maintain its glass transition temperature, and the resulting cured film has a good balance of low thermal expansion rate and high glass transition temperature. In addition, the thermoplastic polyhydroxy polyether resin has a hydroxyl group, so it has good adhesion to the substrate and the conductor, and the resulting cured film is not easily invaded by the roughening agent, but the roughening liquid in the form of an aqueous solution is easy to penetrate to the interface between the cured film and the inorganic filler, so it is easy to remove the inorganic filler on the surface of the cured film by roughening treatment, and it is easy to form a good roughened surface.

The polyvinyl acetal resin can be obtained, for example, by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde is not particularly limited, and examples thereof include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, heptaldehyde, 2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, benzaldehyde, 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde, m-hydroxybenzaldehyde, phenylacetaldehyde, β-phenylpropionaldehyde, etc., preferably butyraldehyde.

Examples of phenoxy resins include phenoxy resins of condensates of epichlorohydrin and various bifunctional phenol compounds, and phenoxy resins obtained by esterifying the hydroxyl groups in the hydroxyl ether portion of the skeleton with various acid anhydrides or acyl chlorides. Specific examples of phenoxy resins include FX280 and FX293 manufactured by NIPPON STEEL Chemical & Material Co., Ltd., and YX8100, YX6954, YL6954, and YL6974 manufactured by Mitsubishi Chemical Co., Ltd. Specific examples of polyvinyl acetal resins include S-LEC KS series manufactured by Sekisui Chemical Industries, Ltd., polyamide resins include KS5000 series manufactured by Hitachi Chemical Industries, Ltd. and BP series manufactured by Nippon Kayaku Co., Ltd., and polyamide-imide resins include KS9000 series manufactured by Hitachi Chemical Industries, Ltd., etc.

In addition, block copolymers can also be used as thermoplastic resins. Block copolymers are copolymers of a molecular structure in which two or more polymers of different properties are linked by covalent bonds to form a long chain.

The blending amount of the thermoplastic resin is preferably 1 to 50 parts by mass, more preferably 1 to 30 parts by mass, based on 100 parts by mass of the curable resin, in terms of solid content. When the blending amount of the thermoplastic resin is within the above range, a uniform roughened surface state can be easily obtained.

[Rubber-like particles] Furthermore, rubber-like particles can be blended into the curable resin composition as needed. By blending rubber-like particles, the softness of the resulting cured film can be improved, or the surface can be roughened using an oxidizing agent to improve the adhesion strength with copper foil, etc.

Examples of such rubber particles include polybutadiene rubber, polyisopropylene rubber, urethane-modified polybutadiene rubber, epoxy-modified polybutadiene rubber, acrylonitrile-modified polybutadiene rubber, carboxyl-modified polybutadiene rubber, acrylonitrile-butadiene rubber modified with carboxyl or hydroxyl groups, crosslinked rubber particles thereof, core-shell rubber particles, etc., and one type thereof may be used alone or two or more types may be used in combination. Examples of core-shell rubber particles include particles having a core-shell structure in which an inner core layer composed of a rubber polymer is covered with an outer shell layer composed of a glassy polymer; particles having an intermediate layer composed of a rubber polymer between the inner core layer composed of a glassy polymer and the outer shell layer; and the like.

The average particle size of the rubber-like particles is preferably in the range of 0.005 to 1 μm, and more preferably in the range of 0.2 to 1 μm. The average particle size of the rubber-like particles in the present invention can be measured using a dynamic light scattering method. For example, the rubber-like particles are uniformly dispersed in an appropriate organic solvent by ultrasound, and the particle size distribution of the rubber-like particles is prepared on a mass basis using FPRA-1000 (manufactured by Otsuka Electronics Co., Ltd.), and the median diameter is used as the average particle size for measurement.

The blending amount of the rubber particles is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the curable resin, calculated as solid content. By blending the rubber particles within the above range, the softness of the resulting cured film can be improved, or the surface can be roughened with an oxidizing agent to improve the adhesion strength with copper foil, etc.

[Inorganic filler] The curable resin composition may further contain an inorganic filler. Examples of the inorganic filler include barium sulfate, barium titanate, titanium oxide, amorphous silica, crystalline silica, fused silica, spherical silica, and the like, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, and the like. Among them, silica is preferred, and spherical silica is more preferred from the viewpoint of high filling.

The amount of the inorganic filler blended in the curable resin layer is preferably 40% by mass or more, more preferably 50% by mass or more and 90% by mass or less, and even more preferably 50% by mass or more and 85% by mass or less, based on the total amount of the composition calculated as solid content.

[Other components] Other conventional components may be further blended into the curable resin composition as required. As other components, colorants, cyanate compounds, elastomers, sulfonyl compounds, urethane catalysts, catalytic agents, adhesion promoters, block copolymers, chain transfer agents, polymerization inhibitors, copper inhibitors, antioxidants, rust inhibitors, thickeners such as asbestos, orben, Benton, and micro-powdered silica, at least one of polysilicone-based, fluorine-based, polymer-based defoaming agents and leveling agents, imidazole-based, thiazole-based, triazole-based silane coupling agents, phosphonates, phosphate derivatives, phosphorus compounds such as nitrogen-phosphorus compounds, and flame retardants may be blended.

Examples of the coloring agent include phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, carbon black, naphthalene black, and the like.

[Organic solvent] An organic solvent may be used in a curable resin composition to prepare a composition, adjust the viscosity for coating on a support, form a curable resin layer of a laminated structure, etc. The type of organic solvent is not particularly limited, and conventionally known organic solvents may be used. In addition, the amount of the organic solvent blended is not limited. The boiling point of the organic solvent is not limited, and those below 100°C or above 100°C may be used.

Examples of organic solvents having a boiling point less than 100°C include diethyl ether, carbon disulfide, acetone, chloroform, methanol, n-hexane, ethyl acetate, 1,1,1-trichloroethane, carbon tetrachloride, methyl ethyl ketone, isopropyl alcohol, trichloroethylene, isopropyl acetate, and the like.

Examples of the organic solvent having a boiling point of 100° C. or higher include alcohol solvents such as isobutanol, n-butanol, and 2-methoxypropanol; ether solvents such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, dipropylene glycol monomethyl ether (DPM), isoamyl alcohol, and ethylene glycol monoethyl ether; ester solvents such as butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; ketone solvents such as cyclohexanone and methyl isobutyl ketone (MIBK); tetrachloroethylene, N,N-dimethylformamide, and rosin oil.

Examples of organic solvents having a boiling point of 100° C. or higher include toluene, xylene, petroleum naphtha, Swasol 1000 (carbon number 8 to 10: high boiling point aromatic hydrocarbons), Swasol 1500 (high boiling point aromatic hydrocarbons) manufactured by Maruzen Petrochemical Co., Ltd., SOLVESSO 100 (carbon number 9 to 10: high boiling point aromatic hydrocarbons), SOLVESSO 150 (carbon number 10 to 11: high boiling point aromatic hydrocarbons) manufactured by Standard Sekiyu Osaka Hatsubaisyo CO., LTD., solvent #100, solvent #150 manufactured by Sankyo Chemical Co., Ltd., Shellsol A100, Shellsol A150 manufactured by Shell Chemicals Japan Ltd., Ipzole No. 100 (the main component is an aromatic hydrocarbon with a carbon number of 9), Ipzole Aromatic solvents such as No. 150 (aromatic hydrocarbons with 10 carbon atoms) are preferred. The high-boiling point aromatic hydrocarbons preferably contain 99% by volume or more of aromatic components. Among the high-boiling point aromatic hydrocarbons, the content of each of benzene, toluene and xylene is preferably less than 0.01% by volume.

[Laminated structure] The laminated structure of the present invention can be manufactured by coating a curable resin composition on a support body, drying the composition, and forming a curable resin layer as a dried coating. A protective film can be laminated on the curable resin layer as required.

As a support, there is no particular limitation as long as it can support the curable resin layer, and plastic films, resin coatings, metal foils, etc. can be used. As plastic films, for example, oriented polypropylene films, polyethylene terephthalate films, polyethylene naphthalate films, polycarbonate films, polyimide films, etc. can be cited. As resin coatings, for example, cured coatings or dried coatings formed by curing or drying a resin composition can be cited. The resin composition may contain a conventionally used resin or solvent. When the resin composition is cured, a thermosetting resin composition preferably contains a thermosetting component, and a photocuring resin composition preferably contains a photocuring component. For example, the above-mentioned thermosetting resin or photocurable resin may also be used. Also, as metal foil, for example: copper foil, aluminum foil, etc. may be cited. Among them, from the viewpoint of versatility, plastic film is preferred, and polyethylene terephthalate film (PET film) is more preferred. The support body and the following protective film may also be subjected to surface treatments such as matte treatment and corona treatment. Also, it is preferred to use a release agent to perform a release treatment, and as the release agent, there may be cited: silicone resin release agent, alkyd resin release agent, fluororesin release agent, etc. Also, the thickness of the support body is preferably 8~60μm.

The material of the protective film can be the same as that used for the support, preferably PET or polypropylene (PP). The thickness of the protective film is preferably 5 to 50 μm. In addition, in the present invention, a curable resin layer can be formed by applying a curable resin composition on the protective film and drying it, and a support can be laminated on its surface. That is, in the present invention, as a thin film on which a curable resin composition is applied when manufacturing a laminated structure, either a support or a protective film can be used.

Here, as a coating method of the curable resin composition for forming the curable resin layer, a dip coating method, a shower coating method, a roll coating method, a rod coating method, a screen printing method, a curtain coating method, etc. can be used. Also, as a volatile drying method, a hot air circulation drying furnace, an IR (infrared) furnace, a heating plate, a convection oven, etc. having a heat source of air heating by steam can be used.

The laminate structure of the present invention is formed by coating a curable resin composition on a support and drying the solvent.

When the laminate structure of the present invention has a protective film on the curable resin layer, after peeling off the protective film, the laminate structure can be heated and laminated in such a way that the curable resin layer side is connected to the substrate, and then the curable resin layer is cured directly in an oven or hot plate pressurized with a support, or by heating or light irradiation. When heating, a hot air circulation drying oven or the like can be used. As a curing condition, in the case of a thermosetting resin, it is preferably cured at 130°C to 250°C for 10 minutes to 60 minutes. In addition, multi-stage curing can be performed as required. When curing the photocurable resin, it is preferably cured using a metal halogen lamp or a high-pressure mercury lamp with an accumulated light intensity of 100 mJ/cm ² to 3,000 mJ/cm ² in the 365 nm wavelength range.

In the above steps, the method of lamination or hot plate pressing is preferred because the fine concavo-convex caused by the inner circuit is eliminated during heating and melting, and the inner circuit is directly solidified, so a multi-layer board with a flat surface state can be obtained in the end. In addition, when the substrate with the inner circuit is laminated or hot plate pressed, the substrate with copper foil or circuit can also be laminated at the same time to form a substrate.

Holes are drilled on the substrate obtained in this way using semiconductor lasers such as _CO2 lasers or UV-YAG lasers or drilling machines. The holes can be through holes (through holes) for connecting the front and back sides of the substrate, or partial holes (conformal through holes) for connecting the circuits of the inner layers with the circuits on the surface of the interlayer insulating layer. At this time, it is preferred to directly drill the holes with the laser in the state of the cured curable resin layer with the support body.

After the hole is opened, the smear existing on the inner wall or bottom of the hole is removed by a commercially available smear removal liquid (roughening agent) or a roughening liquid containing an oxidant such as permanganate, dichromate, ozone, hydrogen peroxide/sulfuric acid, nitric acid, etc. In addition, it is preferred to peel the support from the cured curable resin layer at any time before or after the treatment. The support is preferably peeled off physically by hand, especially when the support is formed by a cured coating or dried coating formed by curing or drying a resin composition, a stripping liquid or the like can also be used for chemical stripping.

Next, after forming holes where the slag has been removed by the slag removal liquid and a film surface with a finely roughened surface, a circuit is formed by a subtractive method or a semi-additive method. In either method, a heat treatment called annealing can be performed at about 80 to 180°C for about 10 to 60 minutes after electroless plating or electrolytic plating, or after both plating processes, in order to remove metal stress and increase strength.

As the metal plating used here, copper, tin, solder, nickel and other combinations can be used without any special restrictions. In addition, metal sputtering can also be used instead of the plating used here.

The laminated structure of the present invention is also suitable for manufacturing printed circuit boards, and is particularly suitable for forming an insulating layer of a printed circuit board such as an interlayer insulating layer or a solder resist. The laminated structure of the present invention can also be used to form a wiring board by bonding wiring. It is also suitable for use as a packaging resin for semiconductor chips. The laminated structure of the present invention is very useful, for example, for smart phones or personal computers.

Embodiment

The present invention is described in more detail below using examples, but the present invention is not limited to the following examples.

(Examples 1 to 4 and Comparative Examples 1 to 3)

The ingredients in the formula shown in Table 1 below are mixed and kneaded and dispersed to a viscosity of 0.5-20 dPa.s (rotational viscometer 5 rpm, 25°C), and the viscosity is adjusted using an appropriate amount of at least one of cyclohexanone and methyl ethyl ketone. Thereafter, a rod coating device is used to apply the curable resin layer to various supports shown in Table 2 (polyethylene terephthalate films with a thickness of 38 μm treated with various release agents as shown in Table 2) so that the film thickness after drying is 50 μm, and then the film is dried for the time and temperature shown in Table 2 below to obtain a laminated structure with a curable resin layer formed on the support. Under the conditions of 70°C and 0.5MPa, a protective film (oriented polypropylene) is laminated on the dry surface of the curable resin layer by roller pressing to obtain a laminated structure with a protective film.

*2: Naphthalene-based epoxy resin (manufactured by DIC Corporation, trade name: EPICLON HP-4032)

*3: Glycerylamine type epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name: 630LSD)

*4: A mixture of bisphenol A epoxy resin and bisphenol F epoxy resin (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name: ZX1059)

*5: Active ester compound (manufactured by DIC Corporation, trade name: HPC-8000BH40)

*6: Semi-solid aliphatic difunctional epoxy resin (manufactured by Mitsubishi Chemical Co., Ltd., trade name: YX7180BH40)

*7: Spherical silica (manufactured by Admatechs Company Limited, trade name: SO-C4)

*8: Thermosetting catalyst (manufactured by Shikoku Chemical Industries, Ltd., trade name: CUREZOL 1B2PZ)

The evaluation method shown below was used to evaluate the layered structures of Examples 1 to 4 and Comparative Examples 1 to 3. The evaluation results are shown in Table 2.

(Peeling strength)

The substrate (500 mm × 600 mm × 0.8 mm (thickness)) with the circuit formed thereon was chemically polished by CZ8101 manufactured by MEC Co., Ltd. Afterwards, the protective films of the laminated structures with protective films of Examples 1 to 4 and Comparative Examples 1 to 3 were peeled off and the laminated structures were subjected to chemical polishing by using a batch vacuum lamination apparatus MLVP-500 (manufactured by Meiki Co., Ltd.) at a pressure of 0.5 MPa. , temperature: 90°C, pressurization time: 1 minute, vacuum degree: 130Pa, laminate the surface of the curable resin layer of the laminated structure with the chemically polished surface of the above substrate. After lamination, heat at 100°C for 30 minutes, and then heat at 180°C for 30 minutes. After heating at 180°C for 30 minutes, cool to room temperature to obtain a laminated structure with a cured curable resin layer.

Afterwards, a 10mm wide and 60mm long cut was formed on the support body with the curable resin layer laminated thereon, and the peel strength (N/cm) between the support body and the curable resin layer was measured at an angle of 90 degrees and a speed of 50mm/min using a desktop tensile tester (EZ-SX manufactured by Shimadzu Corporation). The evaluation length of the peel test was 30mm, and the peel strength was plotted at every 0.5mm, and the average of the 60 measurement points was taken as the peel strength.

In addition, in an environment of 25°C and 50% RH, a fabric containing isopropyl alcohol (IPA) was placed on the surface of a curable resin layer that had been cooled to room temperature and the support body peeled off. Furthermore, a load of 500g was placed on it and left for 1 minute, and then the fabric was peeled off to confirm that the surface of the fabric in contact with the curable resin layer was not adhered to all or part of the curable resin layer.

(The maximum peak height and maximum valley depth of the curing resin layer surface (peeling surface) after the support body is peeled off, and the maximum peak height of the support body surface (peeling surface) after the support body is peeled off)

The maximum peak height Sp and maximum valley depth Sv of the curable resin layer on the test substrate after the support body is peeled off are measured using a 3D white light interference microscope (Contour GT) manufactured by Bruker, using the VSI contact mode and a 50x lens. As a specific measurement method, the sample to be measured is placed on the X-Y stage, the software (Vision 64) is started, and the measurement mode VSI is selected. Then, in the live video mode, the focus and brightness are roughly adjusted with a 10x objective lens. Then, the intensity is adjusted. Then, the XY controller is used to move the measurement point to the bottom of the objective lens. Use the Z-axis controller to gradually approach the sample. Manipulate the Z-axis until the best focus is found, then replace it with a 50x objective lens and adjust the focus to the best position again. Adjust the Tip Tilt as needed to less than 15 fringe. Finally, click the Measurement or Single Acquisition button on the software to start the measurement. As a measurement condition, for an evaluation length of 0.3mm and an evaluation point from the center of the sample of the peeling support to the outside in the peeling strength evaluation, measure the values of Sp and Sv respectively, and average them as the maximum peak height Sp and maximum valley depth Sv of the curing resin layer surface after the support is peeled off. In addition, the maximum peak height Sp of the peeled surface of the support body is measured in the same manner as the maximum peak height Sp of the peeled surface of the curable resin layer after the support body is peeled. The measurement conditions are also for the evaluation length of 0.3mm and the evaluation points are 10 points with equal intervals from the center of the peeled support body used in the peel strength evaluation to the outside, and the values of Sp are measured respectively, and the average is taken as the maximum peak height Sp of the peeled surface of the support body.

(Support body peeling resistance)

In order to evaluate the adhesion with the support body, perform the following steps (1) to (3) to confirm whether the support body is peeled off or falls off during the steps.

(1) Lamination and thermal curing process

The substrate (500 mm × 600 mm × 0.8 mm (thickness)) with the circuit formed thereon was chemically polished by CZ8101 manufactured by MEC Co., Ltd. Afterwards, the protective films of the laminated structures with protective films of Examples 1 to 4 and Comparative Examples 1 to 3 were peeled off and the laminated structures were respectively subjected to the chemical polishing by using a batch vacuum lamination apparatus MLVP-500 (manufactured by Meiki Co., Ltd.). Under the conditions of pressure: 0.5Mpa, temperature: 90℃, pressurization time: 1 minute, vacuum degree: 130Pa, the curable resin layer of the laminated structure is laminated with the chemically polished surface of the above substrate. After lamination, heat at 100℃ for 30 minutes, and then heat at 180℃ for 30 minutes. After heating at 180℃ for 30 minutes, cool to room temperature.

(2) _CO2 laser processing

The support side surface of the laminated structure substrate having a circuit formed thereon prepared in step (1) was processed using a _CO2 laser processing machine (manufactured by Via Mechanics, Ltd.) under the following conditions to form a through hole with a top diameter of 65 μm and a bottom diameter of 50 μm in the curable resin layer.

Aperture (mask diameter): 3.1mm/Pulse width: 20μsec/Output: 2W/Frequency: 5kHz/Number of shots: 3 consecutive shots

(3) Residue removal process

The substrate with a multilayer structure and circuit formed thereon processed in step (2) was desmutted with a commercially available wet permanganic acid desmutting solution (manufactured by ATOTECH) under the following conditions. Specifically, after being treated in Swelling Dip Securiganth P at 60°C for 5 minutes, it was immersed in concentrate compact CP at 80°C for 20 minutes, and then immersed in reduction securigant P500 at 40°C for 5 minutes.

The evaluation criteria are as follows.

○: Even after the slag removal process in step (3), there is no peeling or floating of the support body.

×: The support body peels off or floats off in any of the steps (1) to (3).

(Releasability of coated photoresist in semi-additive process)

In order to evaluate the smoothness, the releasability of the coated photoresist in the semi-additive process was evaluated. The substrate with the circuit formed (500mm×600mm×0.8mm (thickness)) was chemically polished using CZ8101 manufactured by MEC Co., Ltd. Afterwards, the protective films of the layered structures of Examples 1 to 4 and Comparative Examples 1 to 3 were peeled off, and the batch vacuum lamination equipment MLVP-500 (manufactured by Meiki Co., Ltd.) was used at a pressure of 0.5Mpa, a temperature of 90°C, and a heating of 100°C. Under the conditions of 1 minute of pressing time and 130 Pa of vacuum, the curable resin layer of the laminated structure was laminated to the chemically polished surface of the substrate. After lamination, it was heated at 100°C for 30 minutes and then at 180°C for 30 minutes to form a cured film. After heating at 180°C for 30 minutes, it was cooled to room temperature. Then, CO was used to heat the cured film formed on the substrate with the circuit formed on it. ₂ laser processing machines (manufactured by Via Mechanics, Ltd.) were used to process the surface to a top diameter of 65μm and a bottom diameter of 50μm. (Aperture (mask diameter): 3.1mm/pulse width: 20μsec/output: 2W/frequency: 5kHz/number of shots: 3 consecutive shots). Deslagging was then performed using a commercially available wet permanganic acid deslagging solution (manufactured by ATOTECH) under the following conditions. Specifically, after treating in Swelling Dip Securiganth P at 60°C for 5 minutes, the surface was immersed in concentrate compact CP at 80°C for 20 minutes, and then immersed in reduction securigant P500 at 40°C for 5 minutes. The support was then peeled off and the surface was removed using SHIBAURA ELETEC. A 50μm titanium layer was evaporated using a sputtering device CFS-12P-100 manufactured by MEC CORPORATION, and a 300nm copper seed layer was formed thereon. After that, annealing was performed for 1 hour in an inert gas oven filled with nitrogen at 180°. After annealing, a coating photoresist (AZ P4210 manufactured by MEC Co., Ltd.) was applied so that the film thickness after drying would be 5μm, and patterning was performed using an i-ray projection exposure machine manufactured by USHIO INC. Next, an _O2 plasma treatment was performed at an output of 200W for 10 minutes, and then a commercially available electrolytic plating (manufactured by Atotech Japan KK) was used to form a copper plating with a thickness of 4μm. Then, it was immersed in a photoresist stripping solution (10 mass% ENTHONE) heated to 60°C. After stripping the photoresist, observe the stripped surface with an optical microscope to check whether the stripping of the photoresist is defective and evaluate it according to the following criteria.

○: No residue from coating photoresist.

×: There are photoresist residues.

(Patternization)

In order to evaluate the smoothness, the patterning property was evaluated. After confirming the above-mentioned peeling property, the seed layers of copper and titanium were removed by etching, and the conduction of the pattern (pattern A) obtained using the glass mask of Figure 1 was confirmed. In addition, the insulation of the pattern (pattern B) obtained using the glass mask of Figure 2 was confirmed. In addition, in Figures 1 and 2, the black part is the non-exposed part, and the white part is the exposed part.

The evaluation results are based on the following criteria.

○: The resistance value of pattern A is less than 100Ω, and the resistance value of pattern B is more than 1MΩ.

×: The resistance value of pattern A is greater than 100Ω, and the resistance value of pattern B is less than 1MΩ.

It is clear from Table 2 above that the laminated structure of the present invention can achieve a printed circuit board with excellent surface smoothness in the build-up process of printed circuit boards due to the excellent adhesion between the cured curable resin layer and the support body without compromising the yield. In Comparative Example 1, since a mold release agent is not used, a portion of the surface of the curable resin layer is transferred to the side of the support body when the support body is peeled off. As a result, it is believed that the maximum peak height Sp and the maximum valley depth Sv of the peeled surface of the curable resin layer become larger values.

FIG1 is a diagram showing a glass mask used to obtain pattern A, which is used for pattern evaluation. FIG2 is a diagram showing a glass mask used to obtain pattern B, which is used for pattern evaluation.

Claims (3)

A laminate structure comprises a support body subjected to a demolding treatment with a demolding agent and a curable resin layer formed on the demolding treatment surface of the support body, wherein the curable resin layer is composed of a curable resin composition containing a thermosetting resin and an inorganic filler, the blending amount of the inorganic filler is 50 mass % or more and 90 mass % or less based on the total amount of the curable resin composition converted into solid content, and the curable resin After the layer is cured, the peeling strength between the support and the curable resin layer is 0.03N/cm to 0.20N/cm in a 90-degree peeling test. When the curable resin layer is peeled off from the support after being cured, the maximum valley depth Sv of the peeling surface of the curable resin layer is less than 500nm; and when the curable resin layer is peeled off from the support after being cured, the maximum peak height Sp of the peeling surface of the support is less than 500nm. A laminate structure comprises a support body subjected to a demolding treatment with a demolding agent and a curable resin layer formed on the demolding treatment surface of the support body, wherein the curable resin layer is composed of a curable resin composition containing a thermosetting resin and an inorganic filler, the blending amount of the inorganic filler is 50 mass % or more and 90 mass % or less based on the total amount of the curable resin composition converted into solid content, and the curable resin After the layer is cured, the peeling strength between the support and the curable resin layer is 0.03N/cm to 0.20N/cm in a 90-degree peeling test. When the curable resin layer is peeled off from the support after being cured, the maximum peak height Sp of the peeling surface of the curable resin layer is less than 500nm; and when the curable resin layer is peeled off from the support after being cured, the maximum peak height Sp of the peeling surface of the support is less than 500nm. The laminate structure as described in claim 1, wherein when the curable resin layer is peeled off from the support body after being cured, the maximum peak height Sp of the peeling surface of the curable resin layer is less than 500nm.