JP2006284785A - Photosensitive resin composition for insulating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which exhibits physical properties with a small add amount of a photopolymerization initiator and low exposure light quantity and which is excellent in storage stability at normal temperature without decreasing resolution, reliability and nickel gold plating durability, and to provide a layered body using the composition. <P>SOLUTION: The photosensitive resin composition for an insulating film essentially comprises (A) a carboxyl group-containing copolymer obtained by the reaction of a diol compound and polyvalent carboxylic acids and having 2,000 to 40,000 weight average molecular weight and 50 to 200 mgKOH/g acid value, (B) an unsaturated compound having at least one photopolymerizable ethylenically unsaturated bond in one molecule, (C) an epoxy compound, and (D) a photopolymerization initiator; wherein the composition contains the component (C) and the component (D) by 10 to 40 parts by weight and 0.01 to 2.0 parts by weight, respectively, with respect to total 100 parts by weight of the component (A) and the component (B), and contains a compound expressed by general formula (I) used as the photopolymerization initiator of the component (D). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solder resist, a plating resist, an etching resist for forming a circuit board, an insulating film for multilayering a wiring board on which a semiconductor element is mounted, and an insulating resin composition suitable for a photosensitive adhesive. Moreover, it is related with the laminated body formed using the resin composition for insulation.

  With recent downsizing and higher performance of electronic devices, printed wiring boards used therein have also been increased in density. Therefore, fine processing is also required for the workability of the insulating material used for the printed wiring board. A method of patterning by exposure and development is known as an effective means for microfabrication of insulating materials, and photosensitive resin compositions have been used there for higher sensitivity, adhesion to substrates, and reliability. Many characteristics such as crack resistance and storage stability have been demanded.

  A large amount of photopolymerization initiator and sensitizer are added to the insulating material made of a conventional photosensitive resin composition so as to have a resolution capable of opening a small diameter hole of 50 μm or less with a film thickness of 10 to 50 μm. And this has been achieved by increasing sensitivity. Photocuring action by reaction of photoreactive resin and photopolymerization initiator is used for pattern formation, and i-line (365nm) which is one of the line spectrum of mercury lamp is mainly used as the exposure wavelength for curing. in use. The i-line is absorbed by the photosensitive resin composition itself or the colorant, and the photocuring degree is lowered. Moreover, the amount of absorption increases if the film is thick. Therefore, there is a difference in the crosslink density in the film thickness direction in the exposed part, and even if the film surface is sufficiently photocured, it is difficult to photocure on the resin bottom surface. Since it is extremely difficult to make a difference, pattern dimension stability, development margin, pattern adhesion, and pattern edge shape deteriorate, and it is difficult to obtain a photosensitive insulating material that can be developed with high resolution.

  Further, in recent years, in the field of manufacturing insulating materials, particularly solder resists, in order to reduce tact time and increase productivity efficiency, in the exposure process, a photosensitive resin composition that is short in exposure time, that is, photocured at a low exposure amount. Things are sought. In addition, the photopolymerization initiator remaining in the film is released as a decomposition gas by the heat curing of the insulating film layer and the heating process at the time of mounting, and contamination of the drying furnace and clean room and deterioration of mounting reliability in physical property tests, etc. There are also problems. Therefore, there is a demand for an initiator system that has little decomposition volatility and can exhibit an effect with a small amount.

JP 2003-280193 A JP 2002-323762 A JP 2005-77451 A

  Patent Document 1 discloses enhancement of sensitivity by an initiator having an oxime radical generating group and a thioxanthone skeleton. However, the amount of initiator actually used is still as large as 1.0% or more with respect to the resin, and the exposure amount requires 200 mJ. Patent Document 2 discloses an example of high sensitivity using an oxime ester-based photopolymerization initiator in a photosensitive resin composition as a high-sensitivity photopolymerization initiator. It has not reached a satisfactory level. Patent Document 3 uses the same initiator, but the field to which it is applied is a color resist, particularly black, and its blending amount is 2 to 30 parts by weight, and the blending amount with respect to the resin is large. When applied to the above, there are problems such as deterioration of electrical characteristics such as insulation resistance and withstand voltage and deterioration of moisture resistance reliability.

  An object of the present invention is to solve the above-mentioned problems, exhibit physical properties at a low addition amount and low exposure amount, do not impair resolution, reliability and nickel-gold plating resistance, and have excellent storage stability at room temperature. It is providing the composition and a laminated body using the same.

  As a result of intensive investigations to solve the above problems, the present inventors have found that by using an o-acyloxime photopolymerization initiator having a specific chemical structure as a photopolymerization initiator of the photosensitive resin composition, It has been found that physical properties are manifested at an added amount and a low exposure amount, the conventional resolution, reliability and nickel-gold plating resistance are not impaired, and the storage stability at room temperature is excellent, and the present invention has been completed. It was.

但し、一般式(I)において、Ｒ₁は、フェニル基（炭素数１〜６のアルキル基、フェニル基若しくはハロゲン原子で置換されていてもよい）、炭素数１〜２０のアルキル基（１個以上の水酸基で置換されていてもよく、アルキル鎖の中間に１個以上の酸素原子を有していてもよい）、炭素数５〜８のシクロアルキル基、炭素数２〜２０のアルカノイル基又はベンゾイル基（炭素数が１〜６のアルキル基若しくはフェニル基で置換されてもよい）を示し；
Ｒ₂は、炭素数２〜１２のアルカノイル基（１以上のハロゲン原子若しくはシアノ基で置換されていてもよい）、その二重結合がカルボニル基と共役していない炭素数４〜６のアルケノイル基、ベンゾイル基（炭素数１〜６のアルキル基、ハロゲン原子若しくはシアノ基で置換されていてもよい）、炭素数２〜６のアルコキシカルボニル基又はフェノキシカルボニル基（１以上の炭素数１〜６のアルキル基若しくはハロゲン原子で置換されていてもよい）を示し；
Ｒ₃、Ｒ₄、Ｒ₅、Ｒ₆、Ｒ₇、Ｒ₈、Ｒ₉及びＲ₁₀ は、相互に独立に、水素原子、ハロゲン原子、炭素数１〜１２のアルキル基、シクロペンチル基、シクロヘキシル基、フェニル基、ベンジル基、ベンゾイル基、炭素数２〜１２のアルカノイル基、炭素数２〜１２のアルコキシカルボニル基（アルコキシル基を構成するアルキル基の炭素数が２以上の場合、アルキル基は１個以上の水酸基で置換されていてもよく、アルキル鎖の中間に１個以上の酸素原子を有していてもよい）又はフェノキシカルボニル基を示す。 That is, the present invention provides (A) a carboxyl group-containing resin obtained by reacting a diol compound and a polyvalent carboxylic acid, having a weight average molecular weight of 2,000 to 40,000 and an acid value of 50 to 200 mgKOH / g, B) In a resin composition mainly comprising an unsaturated compound containing at least one photopolymerizable ethylenically unsaturated bond in one molecule, (C) an epoxy compound, and (D) a photopolymerization initiator, A total of 100 parts by weight of component (A) and component (B), 10 to 40 parts by weight of component (C), 0.01 to 2.0 parts by weight of component (D), and photopolymerization of component (D) A photosensitive resin composition for an insulating film comprising a compound represented by the following general formula (I) as an initiator.

However, in the general formula (I), R ₁ is a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), or an alkyl group having 1 to 20 carbon atoms (one And may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms, or A benzoyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group);
R ₂ is an alkanoyl group having 2 to 12 carbon atoms (which may be substituted with one or more halogen atoms or cyano groups), or an alkenoyl group having 4 to 6 carbon atoms whose double bond is not conjugated to a carbonyl group. A benzoyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a halogen atom or a cyano group), an alkoxycarbonyl group having 2 to 6 carbon atoms or a phenoxycarbonyl group (having one or more carbon atoms having 1 to 6 carbon atoms) An optionally substituted alkyl group or a halogen atom);
R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ Are independently of each other hydrogen atom, halogen atom, alkyl group having 1 to 12 carbon atoms, cyclopentyl group, cyclohexyl group, phenyl group, benzyl group, benzoyl group, alkanoyl group having 2 to 12 carbon atoms, and 2 to 2 carbon atoms. 12 alkoxycarbonyl groups (when the alkyl group constituting the alkoxyl group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, and one or more oxygen atoms are placed in the middle of the alkyl chain. Or a phenoxycarbonyl group.

Here, examples of the compound represented by the general formula (I) include compounds represented by the following general formula (II).

  The present invention also provides a laminate in which an insulating resin layer is provided on a peelable support substrate, wherein the insulating resin layer is composed of the above photosensitive resin composition for an insulating film. is there. Here, it is possible that the insulating resin layer can be developed with an alkaline aqueous solution, or that the thickness of the insulating resin layer is 10 to 100 μm, which gives a more desirable laminate.

The present invention will be further described below.
The photosensitive resin composition for an insulating film of the present invention is obtained by reacting a diol compound and a polyvalent carboxylic acid, and has a weight average molecular weight of 2,000 to 40,000, preferably 3,000 to 30,000, and an acid value of 50 to 200 mgKOH. / g carboxyl group-containing resin (hereinafter referred to as component (A)), unsaturated compound containing at least one photopolymerizable ethylenically unsaturated bond in one molecule (hereinafter referred to as component (B)), epoxy compound (Hereinafter referred to as component (C)) and a photopolymerization initiator (hereinafter referred to as component (D)).

  The component (A) is obtained by reacting a diol compound and a polyvalent carboxylic acid. As the diol compound, from the viewpoint of increasing the molecular weight during the polymerization reaction, the reactivity of the two hydroxyl groups in the molecule and the polyvalent carboxylic acids, preferably the two acid anhydride groups in the acid dianhydride becomes equal. Those having a symmetric molecular structure are preferred.

  Preferred specific examples of the diol compound include ethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, hydrogenated bisphenol A, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) sulfone, 2,2-bis (4 -Hydroxyphenyl) propane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) hexafluoropropane, 9,9-bis (4-hydroxyphenyl) fluorene, bis (4-hydroxyphenyl) dimethylsilane, 4 , 4'-biphenol and the like. Also, addition compounds of various diglycidyl ethers derived from these diol compounds and (meth) acrylic acid, addition products of alicyclic epoxy and (meth) acrylic acid, addition of the aforementioned bisphenols with ethylene oxide or propylene oxide A thing etc. are mentioned preferably. In particular, the (meth) acrylic acid adduct has a polymerizable unsaturated bond and an alkali-soluble carboxyl group in the same molecule after the reaction with the polyvalent carboxylic acid, and thus is preferable for improving the exposure sensitivity and increasing the resolution.

（但し、Ａｒは2価の芳香族基であり、RはH又はメチル基であり、互いに同じであっても異なっていてもよく、Ｏは芳香族環に直接結合しており、Ｚは１種又は2種以上の多価カルボン酸の残基を示し、ｍは0〜3であり、ｎは1〜20である。） Preferable component (A) includes a resin represented by the following general formula (III).

(However, Ar is a divalent aromatic group, R is H or a methyl group, which may be the same or different from each other, O is directly bonded to the aromatic ring, and Z is 1 A seed or a residue of two or more polyvalent carboxylic acids, m is 0-3, and n is 1-20.)

  Among the carboxyl group-containing resins, a resin having a fluorene skeleton in the unit structure (hereinafter referred to as a fluorene skeleton-containing resin) is preferable in order to develop excellent heat resistance, and is preferably 30% by weight or more in the carboxyl group-containing resin, preferably The use of 50% by weight or more is effective in expressing the heat resistance of the resin composition for insulating films.

（但し、Ｒ₁〜Ｒ₂は水素又はメチル基、Ｒ₃〜Ｒ₁₀は水素、炭素数1〜5のアルキル基又はハロゲンであり、互いに同じであっても異なっていてもよい。） Particularly preferred as the fluorene skeleton-containing resin is a resin having a fluorene skeleton obtained by reacting a fluorene epoxy (meth) acrylate represented by the following general formula (3) with a polyvalent carboxylic acid or an anhydride thereof. By reacting the bisphenol fluorene type epoxy (meth) acrylate with a polyvalent carboxylic acid or an acid anhydride thereof, an alkali-soluble fluorene skeleton-containing resin in which Ar is a fluorene skeleton in the general formula (III) can be obtained. it can. In addition, resin represented by these general formulas may contain a multimer, an unreacted substance, or an intermediate body.

(However, R < ₁ > -R < ₂ > is hydrogen or a methyl group, R < ₃ > -R < ₁₀ > is hydrogen, a C1-C5 alkyl group, or halogen, and may mutually be the same or different.)

  Examples of the polyvalent carboxylic acids to be reacted with the diol compound include polyvalent carboxylic acids, acid anhydrides, acid chlorides, and the like, but acid anhydrides are preferable. The polyvalent carboxylic acids include maleic acid, succinic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, chlorendic acid, methyltetrahydrophthalic acid, pyromellitic acid, benzophenone tetracarboxylic acid. An acid, biphenyl tetracarboxylic acid, biphenyl ether tetracarboxylic acid, etc. can be mentioned, but at least a part is preferably a tetracarboxylic acid or an acid dianhydride. These can be used alone or in combination of two or more.

  The reaction of a diol compound such as epoxy (meth) acrylate and a polyvalent carboxylic acid can be performed by a known method.

  The resin as component (A) is obtained as described above, but the acid value needs to be 50 to 200 mgKOH / g. To adjust the acid value, adjust the amount of polyvalent carboxylic acids to be used, leave some OH groups, or make some or all of the polyvalent carboxylic acids to be used dibasic or tetrabasic. There is a method of adjusting the amount of free carboxyl groups. If the acid value is not within the above range, there arises a problem that good alkali developability cannot be obtained.

Preferred examples of the unsaturated compound (B) include the following acrylates.
Examples of the acrylates include those having a hydroxyl group such as polyethylene glycol (meth) acrylate and butanediol mono (meth) acrylate, for example, allyl (meth) acrylate, butoxytriethylene glycol (meth) acrylate, and methacryloxypropyltrimethoxysilane. Aliphatic (meth) acrylates such as glycidyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, dibromopropyl (meth) acrylate, and alicyclic such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate Modified (meth) acrylates, other aromatic (meth) acrylates, phosphorus-containing (meth) acrylates and the like can be mentioned.

  In addition, bifunctional compounds such as diethylene glycol di (meth) acrylate, bisphenol A di (meth) acrylate, tetrabromobisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, Trifunctional or higher functional compounds such as pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, urethane tri (meth) acrylate Is mentioned.

  And about the said monofunctional compound which has an ethylenically unsaturated bond, a bifunctional compound, and the compound more than trifunctional, the caprolactone, a propylene oxide, an ethylene oxide modified substance, etc. can be used similarly. In addition, other polymerizable monomers, for example, monofunctional compounds such as vinyl compounds such as vinyl acetate, vinyl caprolactam, vinyl pyrrolidone, and styrene can be used as necessary. Of these monofunctional compounds, bifunctional compounds, trifunctional or higher functional compounds, and modified products thereof, not only one of them can be used alone, but also two or more of them can be used in combination.

  In particular, when the resin composition for insulation of the present invention requires excellent photocurability, that is, high sensitivity in addition to alkali solubility, two polymerizable double bonds per molecule (two (Functional) or more, more preferably, a resin or monomer having three (trifunctional) or more is blended. However, the component (B) does not include a resin corresponding to the component (A). And it is desirable that it does not contain a free carboxyl group or has an acid value of 5 mgKOH / g or less. The amount of the unsaturated compound (B) used is preferably in the range of 10 to 200 parts by weight per 100 parts by weight of the resin (A).

  As the epoxy compound (also referred to as epoxy resin) as the component (C), a known polyfunctional epoxy compound (also referred to as resin) can be used. Specifically, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, triglycidyl isocyanurate, diglycidyl isocyanurate, etc. The polyfunctional epoxy resin can be used.

  When the matrix resin is alkali-soluble, the amount of the epoxy compound used as the component (C) is preferably blended within a range in which this alkali-soluble property is maintained. ) It is preferable to blend in the range of 10 to 40 parts by weight with respect to 100 parts by weight of the total components.

  As the photopolymerization initiator of component (D), it contains the compound represented by the general formula (I) as an essential component, generates radical species by irradiation with ultraviolet light, etc., and adds it to the photopolymerizable compound. Radical polymerization is initiated to cure the composition. The compounds represented by the general formula (I) are known in Patent Documents 2 and 3. For the production of such a compound, reference is made to the production method described in Patent Document 2, etc., which teaches similar compounds.

  Among the photopolymerization initiators represented by the general formula (I), the compounds represented by the above formula (II) are preferable.

As the component (D), one or more other photopolymerization initiators and sensitizers can be used in combination with the photopolymerization initiator represented by the general formula (I). Examples of the other photopolymerization initiator and sensitizer include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone. Acetophenones such as benzophenone, benzophenones such as 2-chlorobenzophenone, benzoin ethers such as benzyl, benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2- (o-chlorophenyl) -4,5- Phenylbiimidazole, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) biimidazole, 2- (o-fluorophenyl) -4,5-diphenylbiimidazole, 2- (o-methoxyphenyl) ) -4,5-diphenylbiimidazole, 2,4,5-triarylbi Biimidazole compounds such as imidazole, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5- (p-cyanostyryl) -1,3,4-oxadi Azoles, halomethylthiazole compounds such as 2-trichloromethyl-5- (p-methoxystyryl) -1,3,4-oxadiazole, 2,4,6-tris (trichloromethyl) -1,3,5 -Triazine, 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2-phenyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2- ( 4-chlorophenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-Methoxynaphthyl) -4,6-bis (trichloroRmethyl) -1,3,5-triazine, 2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3 , 5-triazine, 2- (3,4,5-trime Halomethyl such as Toxistyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methylthiostyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine -S-triazine compounds, 1,2-octanedione, 1- [4- (phenylthio) phenyl]-, 2- (O-benzoyloxime), 1- (4-phenylsulfanylphenyl) butane-1,2 -Dione-2-oxime-O-benzoate, 1- (4-methylsulfanylphenyl) butane-1,2-dione-2-oxime-O-acetate, 1- (4-methylsulfanylphenyl) butane-1- O-acyloxime compounds, such as onoxime-O-acetate, which do not contain the above formula (I), benzyldimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2- Sulfur compounds such as methylthioxanthone and 2-isopropylthioxanthone; Anthraquinones such as tilanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, organic peroxides such as azobisisobutylnitrile, benzoyl peroxide, cumene peroxide, 2-mercaptobenzimidazole, Examples include thiol compounds such as 2-mercaptobenzoxazole and 2-mercaptobenzothiazole, but those containing amines that have an effect of accelerating the curing of epoxy resin in the structure of the initiator and sensitizer have storage stability. Should not be used together as it decreases.
These photopolymerization initiators and sensitizers can be used alone or in combination of two or more.

  (D) The usage-amount of the photoinitiator of a component is 0.01-2 weight part on the basis of a total of 100 weight part of each component of (A) and (B), Preferably it is 0.1-1. 0 parts by weight. When the blending ratio of the component (D) is less than 0.01 parts by weight, the rate of photopolymerization is reduced and the sensitivity is lowered. On the other hand, when it exceeds 2 parts by weight, the sensitivity is too strong, The pattern line width becomes thicker than that of the pattern mask, and the line width faithful to the mask cannot be reproduced, resulting in a decrease in resolution. Alternatively, there may be a problem that the pattern edge does not become jagged and sharp. The photopolymerization initiator of the component (D) contains the photopolymerization initiator represented by the general formula (I) as an essential component, but the amount of the photopolymerization initiator alone is not added to the other component (D). It should be more than the amount that effectively acts as a photopolymerization initiator, and the amount is 0.005 to 1.5 parts by weight based on the total of 100 parts by weight of the components (A) and (B). The amount is preferably 0.01 to 0.1 parts by weight.

  As other resin components, known rubber components can be added for improving impact resistance, adhesion to the plated metal during processing, and the like. Among the rubber components, a crosslinked elastic polymer having a carboxyl group is preferable. Specific examples include a crosslinked acrylic rubber having a carboxyl group, a crosslinked NBR having a carboxyl group, and a crosslinked MBS having a carboxyl group. When a rubber component is used, those having an average particle size of a primary particle size of 0.1 μm or less are preferably used in the range of 3 to 10 parts by weight with respect to 100 parts by weight of the resin component.

  In addition, the resin composition for an insulating film of the present invention has one kind of inorganic filler such as silica, alumina, titanium oxide, boron nitride, etc. for the purpose of reducing the thermal expansion of the cured product and improving the elastic modulus and hygroscopicity. Or you may mix | blend 2 or more types. Furthermore, other additives such as an epoxy resin curing accelerator, a polymerization inhibitor, a plasticizer, a leveling agent, and an antifoaming agent can be blended with the resin composition for an insulating film of the present invention as necessary. .

  The resin composition for an insulating film of the present invention can be adjusted in viscosity by blending a solvent as necessary. The solvent must be one that dissolves the resin component of the resin composition and does not react with the resin and additives, and is not particularly limited as long as these conditions are satisfied.

  The method of using the resin composition for an insulating film of the present invention includes 1) a method in which a solvent is added to prepare a varnish, and this is applied to a target object to form an insulating resin layer. Examples thereof include a method in which the resin composition for a film is previously applied on a support substrate to be peeled and removed later to form a laminate from which the solvent has been removed (dry film).

  When used as a varnish, for example, a resin composition prepared in the form of a varnish is applied onto a substrate by means of spin coating, curtain coating, etc., a pattern is formed by drying, exposure, and development, followed by thermosetting. Can be mentioned.

  When the laminate is used in advance, the insulating resin composition of the present invention is uniformly applied on a supporting substrate, the solvent is dried by hot air drying or the like, and then a protective film is provided if necessary. The method of winding over is illustrated. The drying temperature is preferably 80 to 120 ° C. in consideration of the thermal stability and productivity of the unsaturated compound. In addition, it is desirable to raise the temperature in multiple stages in order to prevent skinning and foaming of the coating film surface during drying. Although the organic solvent often remains in the resin layer after drying, the content is desirably 15% by weight or less, preferably 10% by weight or less. The content referred to here is a weight% that is reduced when the weight of the resin layer after drying is 100% by weight and the absolute dry weight is obtained after drying again at 200 ° C. for 30 minutes. If this exceeds 15% by weight, cold flow tends to occur.

  As a support base material (film) which apply | coats a resin composition, the transparent thing which permeate | transmits active light is desirable. Examples of the support layer that transmits active light include known polyethylene terephthalate films, polyacrylonitrile films, optical polypropylene films, and cellulose derivative films. The thinner these films are, the more advantageous in terms of image forming property and economy, but those having a thickness of 10 to 30 μm are generally used because of the need to maintain the strength. Moreover, in the laminated body of this invention, a protective film can be laminated | stacked as needed on the surface of the insulating resin layer which is not in contact with the support substrate. It is desirable that this protective film has a sufficiently smaller adhesion with the insulating resin layer than the support film and can be easily peeled off. An example of such a film is a polyethylene film.

  Regardless of the method of use, the thickness of the insulating resin layer after drying varies depending on the application, but is 5 to 100 μm, preferably 10 to 60 μm for circuit boards. If the thickness is 5 μm or less, the electric insulation is insufficient, which causes a decrease in withstand voltage value or a problem of migration in a bias test at the time of moisture resistance. A film thickness of 100 μm or more is not preferable because a pattern formed due to insufficient curing of the bottom portion becomes a reverse taper, which causes a problem of peeling due to infiltration of the plating solution into the pattern portion or insufficient adhesion. In the color filter application found in Patent Document 3, a thinner film thickness is employed because of the problem of color purity reproducibility and patterning shape. The thinner the resin layer is, the higher the resolution is, and it is possible to form vias and fine lines equal to or less than the thickness of the resin layer. For example, when the film thickness is 30 μm, a 30 μm via and a 20 μm line and space can be formed. In addition, an isolated line and isolated dot of 20 μm can be formed at 5 μm.

  The resin composition of the present invention can be used as a general insulating material, and is particularly used in an interlayer insulating resin for buildup substrates, an outermost insulating resin, a solder resist, and a plating resist.

Production of a circuit board using the laminate of the present invention and production of a multichip module are performed by a known technique. The process will be briefly described below by taking the production of a circuit board as an example.
When there is a protective film, the protective film is first peeled off, and then the insulating resin layer is heated and pressure-bonded to the substrate surface with a vacuum laminator or a hot roll laminator and laminated. The heating temperature at this time is 70-120 degreeC, Preferably it is 80-110 degreeC. When the temperature is lower than 70 ° C., the adhesion to the substrate is inferior, and when the temperature is higher than 120 ° C., the insulating resin layer protrudes from the side edge and the film thickness accuracy is impaired. Next, the image is exposed with active light through a mask. Subsequently, the support substrate is peeled off, and the unexposed portion of the insulating resin layer is developed and removed using an alkaline aqueous solution. As the alkaline aqueous solution, an aqueous solution of sodium carbonate, potassium carbonate, potassium hydroxide, diethylamine, tetramethylammonium hydroxide or the like can be used. These developers are selected according to the characteristics of the resin layer, but can be used in combination with a surfactant. Then, polymerization or curing (sometimes referred to as curing together) is completed by heat to obtain an insulating resin such as a permanent insulating film. The curing temperature at this time is preferably in the range of 160 to 200 ° C.

  Furthermore, when forming the insulating layer for buildup substrates, after patterning the insulating layer as described above, electroless copper plating is performed by a known means, and electrolytic copper plating is performed as necessary to form a conductor layer. In addition, it is preferable to anneal after electrolytic copper plating. If a circuit is formed by selectively etching away the conductor layer and then repeating the process of laminating the insulating layer again, a multilayer circuit board can be formed.

  The resin composition for insulation of the present invention exhibits a physical property at a low addition amount and a low exposure amount, does not impair resolution, reliability and nickel gold plating resistance, and has excellent storage stability at room temperature and The laminated body using this can be provided, and industrial utility value is very high.

Hereinafter, the present invention will be described in more detail with reference to synthesis examples, examples, and comparative examples.
In addition, evaluation of resin in the following synthesis examples is as follows unless otherwise noted.
[Solid Concentration] About 1 g of the resin solution was impregnated in a glass filter W ₀ (g), weighed W ₁ (g), and heated at 160 ° C. for 2 hours, followed by weight W ₂ (g). Obtained by the formula.
Solid content concentration (% by weight) = 100 × (W ₂ −W ₀ ) / (W ₁ −W ₀ )
[Acid Value] The resin solution was placed in a dioxane-ethanol equal volume mixed solution and titrated with a 1/10 N-KOH ethanol (50%) aqueous solution using phenolphthalein as an indicator.
[Molecular Weight] The molecular weight was determined by gel permeation chromatography (GPC) equipped with an RI (refractive index) detector using tetrahydrofuran as a developing solvent. The molecular weight shown is the weight average molecular weight (Mw) in terms of polystyrene of the carboxyl group-containing copolymer portion excluding unreacted raw materials.

The abbreviations used in the synthesis examples are as follows.
FHPA: Equivalent reaction product of fluorene type epoxy resin and acrylic acid (ASF-400 manufactured by Nippon Steel Chemical Co., Ltd .; in formula IV, R _{1 to} R ₁₀ are all hydrogen atoms, and have an acid value of 1.28. mgKOH / g, epoxy equivalent 21300)
BPDA: Biphenyltetracarboxylic dianhydride
THPA: Tetrahydrophthalic anhydride
SA: Succinic anhydride
PGMEA: Propylene glycol monomethyl ether acetate
TPP: Triphenylphosphine
BHT: 2,6-ditertiary butyl-P-cresol

Synthesis example 1
In a 500 ml four-necked flask equipped with a reflux condenser, bisphenolfluorene type epoxy resin 75.0 g (ESF-300 manufactured by Nippon Steel Chemical Co., Ltd., epoxy equivalent 257), triethylbenzylammonium chloride 130 mg, tetraethylbenzylumonium bromide 270 mg, 29 mg of 2,6-diisobutylphenol, 21.0 g of acrylic acid and 17.0 g of PGMEA were charged, and the reaction was carried out by stirring at 100 to 105 ° C. for 16 hours while blowing dry air at a rate of 20 ml / min. . The obtained resin was further diluted with 79 g of PGMEA, and a light yellow transparent dihydroxypropyl acrylate resin solution having a solid content concentration of 50% by weight (FHPA solution: acid value 1.28 mgKOH / g in terms of solid content, epoxy equivalent 21300) )

Synthesis example 2
Into a 300 ml four-necked flask with a reflux condenser, 96.0 g of the FHPA solution obtained in Synthesis Example 1, 14.4 g of BPDA, 2.5 g of PGMEA, 0.182 g of TPP, and 0.015 g of BHT are charged and heated to 120 to 125 ° C. The mixture was stirred for 2 hours, and further heated and stirred at 60 to 62 ° C. for 8 hours to synthesize carboxyl group-containing resin solution A-1. The obtained resin solution had a solid content of 56.5 wt%, an acid value (converted to a solid content) of 90.3 mg KOH / g, an area of the carboxyl group-containing resin by GPC analysis of 90%, and a weight average molecular weight (Mw) of 15000. .

Synthesis example 3
Into a 300 ml four-necked flask equipped with a reflux condenser, 96.0 g of the FHPA solution obtained in Synthesis Example 1, 10.8 g of BPDA, 5.6 g of THPA, 1.64 g of PGMEA, 0.182 g of TPP, and 0.015 g of BHT are charged. The mixture was stirred at 125 ° C. for 2 hours with heating, and further heated and stirred at 60 to 62 ° C. for 8 hours to synthesize a carboxyl group-containing resin solution A-2. The obtained resin solution had a solid content of 56.5 wt%, an acid value (converted to a solid content) of 88.1 mg KOH / g, an area of the carboxyl group-containing resin by GPC analysis of 96%, and Mw of 5400.

Synthesis example 4
In a 500 mL four-necked flask equipped with a reflux condenser, 238.0 g of the FHPA solution obtained in Synthesis Example 1 and 9.81 g of SA, 28.8 g of BPDA, 0.456 g of TPP, 0.0365 g of BHT and 10.36 g of PGMEA were charged. The mixture was heated and stirred in an oil bath at 120 to 125 ° C. for 1 hour, and then stirred in an oil bath at 75 to 80 ° C. for 6 hours. The obtained resin solution A-3 had a solid content of 55 wt%, an acid value (resin solid content conversion) of 112.2 mgKOH / g, a carboxyl group-containing resin area of 91%, and an Mw of 2800.

Synthesis example 5
In a 500 mL four-necked flask equipped with a reflux condenser, 238.0 g of the FHPA solution obtained in Synthesis Example 1, SA 14.9 g, 21.3 g of BPDA, 0.456 g of TPP, 0.0365 g of BHT, and 8.4 g of PGMEA were charged. Thus, a carboxyl group-containing resin solution A-4 was obtained. The obtained resin had a solid content of 55.4 wt%, an acid value (resin solid content conversion) of 120.0 mgKOH / g, a carboxyl group-containing resin area of 90%, and Mw of 2400.

  The carboxyl group-containing resin solutions A-1 and A-2 obtained in Synthesis Examples 2 and 3 were each 30 parts by weight (total 60 parts by weight) in terms of resin component, and trimethylolpropane triacrylate (Nippon Kayaku Co., Ltd.) as an unsaturated compound. TMPTA manufactured by TMPTA Co., Ltd. 12 parts by weight, cross-linked rubber as rubber component (15% solution of XER-91-MEK dispersion manufactured by JSR Co., Ltd.) 7 parts by weight in terms of solid content, represented by general formula (II) as a photopolymerization initiator 0.1 part by weight of compound, 26 parts by weight of epoxy resin (Epicoat 834 manufactured by Japan Epoxy Resin Co., Ltd.), 0.8 part by weight of colorant as other additives, 0.5 part by weight of silane coupling agent, surfactant 0.3 parts by weight and 100 parts by weight of ethyl acetate were mixed, and dissolved or dispersed for 1 hour using a stirring blade with a peripheral speed of 0.5 m / second at the blade tip to prepare a resin composition solution. Then, pressure filtration was performed using a filter having a hole diameter of 1 μm to prepare a resin composition solution.

  The resin composition solution prepared as described above was applied to a polyester film having a thickness of 19 μm and a width of 600 mm by a die coater, and dried in a continuous four-stage drying oven set at a temperature range of 80 to 120 ° C. An insulating resin layer was obtained. A protective film made of polypropylene having a thickness of 40 μm was laminated on the dried coating film to prepare a dry film laminate.

After blackening a conductor circuit pattern on a commercially available glass epoxy substrate having a thickness of 0.8 mm, the protective film is peeled off from the dry film laminate. Vacuum lamination was performed at 0.5 MPa and a pressurization time of 20 seconds, and a 30 μm thick insulating resin layer with a polyester film was formed on the conductor circuit pattern to obtain a photosensitive resin laminated substrate. Next, UV irradiation is performed through a negative mask provided with a via hole pattern on the insulating resin layer with an ultra-high pressure mercury lamp (Hitech, illuminance 11 mJ / cm ² , I-line standard) at 30 mJ / cm ^2. After the exposure by, the polyester film was peeled off, and a 1.2% tetramethylammonium hydride solution was used as a developer. After developing for 1 minute until the conductor circuit pattern was exposed while swinging at 28 ° C. Pure water rinsing was performed at a pressure of 3.0 kg / cm ² for 30 seconds to form a via hole having a diameter of 35 μm. Subsequently, a conductor circuit test piece (multilayer wiring printed board) in which the insulating film was cured by thermosetting at 180 ° C. for 90 minutes in an air atmosphere was obtained.

The following evaluation was performed under the development conditions described above.
(Sensitivity evaluation)
Using the photosensitive resin laminate substrate, a substrate exposed using a 21-step tablet made by Stouffer Graphic Arts as a negative mask was developed under the above development conditions, and the number of steps of the remaining coating film was visually determined.

(Resolution evaluation)
The substrate exposed with a negative mask provided with a 10-100 μm via hole pattern was developed under the above development conditions, and the minimum via diameter was measured. Moreover, after laminating the insulating resin layer on the conductor circuit pattern, it was stored at 25 ° C. for 7 days, and the resolution was evaluated under the same conditions. In Example 1 using the compound of formula (II) as the photopolymerization initiator, a 35 μm via could be formed. In addition, development was possible with the same resolution even after storage for 7 days.

(Heating weight reduction rate)
Using the photosensitive resin laminate substrate, the weight reduction rate was measured from the weight W ₁ (g) after exposure and the weight W ₂ (g) after thermosetting at 180 ° C. for 90 minutes by the following formula.
Heating weight reduction rate = 100 × (W ₁ −W ₂ ) / W ₁

(PCT resistance test)
Using a conductor circuit test piece, a moisture resistance reliability test was conducted for 192 hours under the conditions of 121 ° C., relative humidity 100%, and 2 atmospheres, and the state of the coating film was visually determined according to the following criteria.
A: No change is seen at all.
○: Almost no change is observed.
Δ: Slightly changed ×: Remarkable changes such as swelling and swelling fall off are observed in the coating film.

(Solder heat resistance test)
Using a conductor circuit test piece, in accordance with the test method of JIS C-6481, immersed in a solder bath at 260 ° C for 30 seconds, and peeling test with a cellophane tape as one cycle. These conditions were visually observed and evaluated according to the following criteria. The results are summarized in Table 1.
(Double-circle): Even if it repeats 3 cycles, there is no abnormality in a coating film.
A: After repeating 3 cycles, a slight change is observed in the coating film.
(Triangle | delta): After repeating 2 cycles, a change is recognized by the coating film.
X: After repeating 1 cycle, a change is recognized by the coating film.

(Electroless gold plating test)
After conducting electroless nickel-gold plating (Meltex Co., Ltd. gold plating solution) using a conductor circuit test piece, visually observe the state of the coating film after the peeling test with cellophane tape, and according to the following criteria evaluated. The results are summarized in Table 1.
A: No abnormality in the coating film.
○: A slight change is observed in the coating film.
Δ: Change is clearly observed in the coating film.
X: The coating film swells and changes such as swelling and desorption are observed.

  The test was conducted in the same manner as in Example 1 except that 0.01 parts by weight of the compound represented by the general formula (II) was used as a photopolymerization initiator.

  The test was conducted in the same manner as in Example 1 except that 1.0 part by weight of the compound represented by the general formula (II) was used as the photopolymerization initiator.

  Example 1 except that 6 parts by weight of dipentaerythritol hexaacrylate (KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.) and 6 parts by weight of DPCA-60 (KAYARAD DPCA-60 manufactured by Nippon Kayaku Co., Ltd.) were used as unsaturated compounds. A similar test was conducted.

The test was conducted in the same manner as in Example 1 except that 60 parts by weight of the carboxyl group-containing resin solution A-3 obtained in Synthesis Example 4 was used in terms of resin component, and a 1% Na ₂ CO ₃ aqueous solution was used as the developer. It was.

The test was conducted in the same manner as in Example 1 except that 60 parts by weight of the carboxyl group-containing resin solution A-4 obtained in Synthesis Example 5 was used in terms of resin component, and a 1% Na ₂ CO ₃ aqueous solution was used as the developer. It was.

Comparative Examples 1-2
The test was conducted in the same manner as in Example 1 except that 0.005 part by weight or 5.0 parts by weight of the compound represented by the general formula (II) was used as the photopolymerization initiator.

Comparative Example 3
Example 1 except that 2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine (indicated as STR-A in the table) was used as the photopolymerization initiator A similar test was conducted.

Comparative Example 4
After blending the resin in the same manner as in Comparative Example 3, the test was performed in the same manner as in Example 1 except that the exposure was performed at 300 mJ.

Comparative Example 5
Except for using 2 parts by weight of 2-methyl-1- [4- (methylthio) phenyl] -2-monoforinopropane-1 (Irgacure 907 manufactured by Ciba Specialty Chemicals Co. Ltd.) as a photopolymerization initiator The test was conducted in the same manner as in Example 1.

Comparative Example 6
As a photopolymerization initiator, 2-part weight of 2-methyl-1- [4- (methylthio) phenyl] -2-monoforinopropane-1 (Irgacure 907 manufactured by Ciba Specialty Chemicals Co. Ltd.), a sensitizer ( The test was performed in the same manner as in Example 1 except that 0.04 part by weight of EABF manufactured by Hodogaya Chemical Co., Ltd. was used.

Comparative Example 7
After blending the resin in the same manner as in Comparative Example 5, the test was performed in the same manner as in Example 1 except that the exposure was performed at 1000 mJ.

Comparative Example 8
After blending the resin in the same manner as in Comparative Example 6, the test was performed in the same manner as in Example 1 except that the exposure was performed at 500 mJ.

Comparative Example 9
As a photopolymerization initiator, 2-part weight of 2-methyl-1- [4- (methylthio) phenyl] -2-monoforinopropane-1 (Irgacure 907 manufactured by Ciba Specialty Chemicals Co. Ltd.), a sensitizer ( The test was conducted in the same manner as in Example 5 except that 0.04 part by weight of EABF manufactured by Hodogaya Chemical Co., Ltd. was used.

Comparative Example 10
As a photopolymerization initiator, 2-part weight of 2-methyl-1- [4- (methylthio) phenyl] -2-monoforinopropane-1 (Irgacure 907 manufactured by Ciba Specialty Chemicals Co. Ltd.), a sensitizer ( The test was performed in the same manner as in Example 6 except that 0.04 parts by weight of EABF manufactured by Hodogaya Chemical Co., Ltd. was used.

  The composition (parts by weight) and the measurement results are summarized in Table 1.

  Examples 1 to 6 showed good sensitivity, resolution, storage stability, and reliability, while Comparative Example 1 had a low sensitivity of 3 steps and a decrease in film thickness. In Comparative Example 2, the resolution was deteriorated, and only the via hole up to 50 μm could be resolved. Moreover, the fall of moisture resistance reliability was seen. In Comparative Example 3, no pattern remained. In Comparative Example 4, an exposure amount of 300 mJ was required to leave the same pattern as in Example 1, and there was a problem in nickel-gold plating resistance. In Comparative Examples 5 and 6, no pattern remained. In Comparative Example 7, an exposure amount of 1000 mJ was required to leave the same pattern as in Example 1, and in Comparative Example 8, an exposure amount of 500 mJ was required to leave the same pattern as in Example 1. In Comparative Example 8 using a sensitizer, the storage stability was deteriorated. In Comparative Examples 7 and 8, the rate of weight loss by heating increased, and it was confirmed that degassed components were generated. In Comparative Examples 9 and 10, no pattern remained.

Claims (5)

(A) a carboxyl group-containing resin obtained by reacting a diol compound and a polyvalent carboxylic acid, having a weight average molecular weight of 2,000 to 40,000 and an acid value of 50 to 200 mg KOH / g,
(B) an unsaturated compound containing at least one photopolymerizable ethylenically unsaturated bond in one molecule,
(C) an epoxy compound, and (D) a photopolymerization initiator,
In the resin composition containing as a main component, (C) component is contained in 10 to 40 parts by weight and (D) component is contained in 0.01 to 2.0 parts by weight with respect to a total of 100 parts by weight of component (A) and component (B). And a photosensitive resin composition for insulating films, comprising a compound represented by the following general formula (I) as a photopolymerization initiator of the component (D):

However, in the general formula (I), R ₁ is a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), or an alkyl group having 1 to 20 carbon atoms (one And may have one or more oxygen atoms in the middle of the alkyl chain), a cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms, or A benzoyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group);
R ₂ is an alkanoyl group having 2 to 12 carbon atoms (which may be substituted with one or more halogen atoms or cyano groups), or an alkenoyl group having 4 to 6 carbon atoms whose double bond is not conjugated to a carbonyl group. A benzoyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a halogen atom or a cyano group), an alkoxycarbonyl group having 2 to 6 carbon atoms or a phenoxycarbonyl group (having one or more carbon atoms having 1 to 6 carbon atoms) Which may be substituted with an alkyl group or a halogen atom);
R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ Are independently of each other hydrogen atom, halogen atom, alkyl group having 1 to 12 carbon atoms, cyclopentyl group, cyclohexyl group, phenyl group, benzyl group, benzoyl group, alkanoyl group having 2 to 12 carbon atoms, and 2 to 2 carbon atoms. 12 alkoxycarbonyl groups (when the alkyl group constituting the alkoxyl group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, and one or more oxygen atoms are placed in the middle of the alkyl chain. Or a phenoxycarbonyl group. 2. The photosensitive resin composition for an insulating film according to claim 1, wherein the compound represented by the general formula (I) is a compound represented by the following general formula (II).

  A laminate in which an insulating resin layer is provided on a peelable support substrate, wherein the insulating resin layer is composed of the photosensitive resin composition for an insulating film according to claim 1 or 2. .   The laminate according to claim 3, wherein the insulating resin layer can be developed with an alkaline aqueous solution.   The laminate according to claim 3 or 4, wherein the insulating resin layer has a thickness of 10 to 100 µm.