JPH11242330A - Photosensitive resin composition, multilayered printed circuit board using that, and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin compsn. which gives high adhesion strength when a conductive layer is formed by plating on a resin layer, to provide a photosensitive resin compsn. which can form an insulating layer having excellent heat resistance, moisture- resistant reliability and adhesion strength for a multilayered printed circuit board, especially a buildup multilayered printed circuit board, and to provide a multilayered printed circuit board having excellent adhesion strength and its producing method. SOLUTION: This photosensitive resin compsn. contains an org. filler and a photopolymn. initiator as essential components in an alkali-soluble resin matrix. At least a part of the alkali-soluble resin consists of an alkali-soluble resin having a fluorene structure, and the amt. of the org. filter is 10 to 100 pts.wt. to 100 pts.wt. of the alkali-soluble resin. The average particle size and coefft. of variation of the org. filler are 5 to 20 μm and <=50%, respectively. The multilayered printed circuit board has an insulating layer formed by hardening the photosensitive resin compsn. above described. When the multilayered printed circuit board is produced by a buildup method using the photosensitive resin compsn., annealing after plating is carried out under more severe conditions than the conditions of post-curing of the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photosensitive resin composition, a multilayer printed wiring board using the same, and a method for producing the same. The photosensitive resin composition of the present invention is particularly suitable for forming an insulating layer of a multilayer printed wiring board by a build-up method.

[0002]

2. Description of the Related Art As a method of forming a conductor layer on a resin layer, a method of forming a metal thin film on a resin surface by using a thin film forming technique such as vapor deposition and sputtering, and a method of depositing electroless plating on a resin surface. There is known a method of forming a metal layer on a resin surface by attaching a catalyst nucleus and immersing it in an electroless plating bath. The formation of the conductor layer by electroless plating is typically performed by plating on a through-hole portion of a resin-based printed circuit board. Only a necessary portion on the base material has a film thickness of 10 μm or more by electroless plating. An additive method for forming a circuit by forming a conductor layer is known. Also, a full additive method is known as another method.

[0003] In these methods, in order to improve the plating adhesion of the insulating layer, a resin composition in which an insulating resin for forming the insulating layer is mixed with a rubber and a filler is cured. The filler and rubber are removed with an acid mixture, etc., and these are removed to form irregularities. A conductor layer is formed on the roughened insulating layer by electroless copper plating or electroless copper plating and electrolytic copper plating. Is what you do. However, in this method, there is a problem that rubber remaining in the insulating resin layer deteriorates heat resistance and electric insulation. Further, the chromic acid mixed solution used for improving the adhesion strength has a problem in working environment and safety and health.

In recent years, with respect to multilayer printed wiring boards, the number of layers has been increased, and a higher value of the adhesion strength between the insulating layer and the conductor layer has been required.

[0005] In order to improve the adhesion between the insulating layer and the conductor layer, substances having different solubility in the roughening solution are dispersed, and components soluble in the roughening solution are desorbed. It is known to form indentations. For example, JP-A-60-167492 proposes a method of dispersing an inorganic insulator in an insulating resin.
No. 52 proposes a method using a combination of a phenolic resin, an inorganic carbonate and a synthetic rubber.
No. 35545 discloses a method of dispersing acid / alkali-soluble inorganic salt particles in a resin matrix which becomes hardly soluble after curing. However, all of these methods have problems in terms of humidity resistance and the like.

[0006] Japanese Patent Application Laid-Open No. 3-18096 discloses that
A method of dispersing a synthetic rubber in an epoxy resin to selectively remove only the rubber is disclosed. In the Journal of the Adhesion Society of Japan, Vol. 31, No. 1, page 12, ('95), phenol resin is dispersed in a nitrile rubber. Although a method of forming a convex surface by selectively removing a rubber layer has been proposed, the use of rubber has the above-described problem. Also, Japanese Patent Laid-Open No. 5-2
Japanese Patent No. 35546 discloses a method of dispersing acid / alkali-soluble organic particles in a resin matrix which becomes hardly soluble after curing, but requires particles having a special composition.
Further, Japanese Patent Application Laid-Open No. 8-14827 discloses a method of mixing a photo-modified resin powder or silica, which is disclosed in Japanese Patent Application Laid-Open No. 9-1625.
No. 49 discloses a method in which the resin applied to the substrate is incompletely cured without adding a filler, thereby facilitating the roughening of the resin surface and improving the adhesiveness. There is room for improvement, such as not being obtained.

There are several methods for manufacturing a multilayer printed wiring board by the build-up method. An example of a method of using a copper-clad laminate is shown below. First, an etching resist is applied on copper on a surface, and a circuit is exposed and developed.
Print. Unnecessary copper other than the circuit is removed by etching,
Forming a first conductor layer; A resin is applied on this, a resin layer is formed, and a via hole is exposed using a photomask,
After the development, the remaining resin is post-cured to completely cure the resin, and the surface is oxidized with a permanganic acid solution or the like to be roughened. Then, electroless plating and electrolytic plating are performed on the roughened surface to form a conductor layer, and then annealing is performed to remove distortion inside the conductor layer. Then, a second layer of insulating resin is applied thereto, and by repeating the above operation,
Increase the number of layers. In such a build-up method, not only the adhesion strength between the resin layer and the conductor layer becomes more important, but also high performance such as heat resistance and moisture resistance is required.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin composition which gives high adhesive strength when forming a conductor layer on a resin layer by plating.
Another object of the present invention is to provide a photosensitive resin composition capable of forming an insulating layer having excellent heat resistance, moisture resistance reliability, and adhesion strength in a multilayer printed wiring board, especially in a build-up multilayer printed wiring board. Another object of the present invention is to provide a multilayer printed wiring board having excellent adhesive strength and a method for manufacturing the same.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve such problems, and as a result, have found that a photosensitive resin for forming an insulating layer of a multilayer printed wiring board in which a specific resin and a specific organic filler are combined. The present inventors have found that the desired problem can be solved by improving the heat treatment conditions in the production of a resin composition and a printed wiring board using the photosensitive resin composition, and have reached the present invention.

That is, the present invention relates to a resin composition containing an organic filler and a photopolymerization initiator as essential components in an alkali-soluble resin matrix, wherein at least a part of the alkali-soluble resin has a fluorene skeleton. Resin, the content of the organic filler is 10 to 100 parts by weight based on 100 parts by weight of the alkali-soluble resin, the average particle size of the organic filler is 5 to 20 μm, and the coefficient of variation of the particle size is 50% or less. It is a photosensitive resin composition characterized by the following. Further, the present invention is a multilayer printed wiring board formed by forming an insulating layer with a cured product of the photosensitive resin composition, and the present invention further provides a multilayer printed wiring board using the photosensitive resin composition by a build-up method. In manufacturing the wiring board, annealing after plating,
A method for manufacturing a multilayer printed wiring board, which is performed under more severe conditions than post-cure of a resin.

The resin used as the matrix component of the photosensitive resin composition of the present invention is an alkali-soluble resin, at least a part of which is an alkali-soluble resin having a fluorene skeleton. The alkali-soluble resin having a fluorene skeleton is not limited as long as it is a resin having a fluorene skeleton in its main chain and being alkali-soluble, but preferably a bisphenol compound having a fluorene skeleton represented by the following general formula (1) Is further reacted with an epoxy (meth) acrylate having a fluorene skeleton obtained by reacting an epoxy compound obtained by epoxidation of the compound with epichlorohydrin or the like with (meth) acrylic acid, and a polycarboxylic acid or an anhydride thereof. This is an epoxy (meth) acrylate acid adduct having a fluorene skeleton obtained by the above method.

[0012]

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In the general formula (1), R ₁ and R ₂ are hydrogen, an alkyl group having 1 to 5 carbon atoms or halogen,
Preferably it is hydrogen or a methyl group. Also, R ₁ and R
The substitution position of ₂ is 3-position, 5-position or 3,5-position.

The epoxidation of the bisphenol compound can be carried out in the same manner as a usual epoxidation reaction. For example, after dissolving a bisphenol compound in excess epichlorohydrin, the mixture is reacted at 50 to 150 ° C, preferably 60 to 120 ° C for 1 to 10 hours in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. Method.

The reaction between the epoxy compound and (meth) acrylic acid is carried out in such a manner that (meth) acrylic acid is used in an amount of about 0.8 to 1.5 mol, preferably 0.9 to 1 mol, per mol of the epoxy group of the epoxy compound. .1 mole is preferred. As a diluent for the reaction, for example, methyl ethyl ketone, methyl cellosolve acetate and the like can be used. Further, in order to promote the reaction, a catalyst such as triethylamine, benzyldimethylamine, methyltriethylammonium chloride, triphenylphosphine and the like may be used. The amount of the catalyst used is usually 0.1 to 10% by weight, preferably 0.3 to 5% by weight based on the reaction raw material mixture.
And the reaction temperature is 60 to 150 ° C., preferably 80 to 150 ° C.
120 ° C., reaction time is 5 to 60 hours, preferably 10 to
50 hours.

Next, the epoxy (meth) acrylate having a fluorene skeleton obtained as described above is converted into an acid adduct thereof. As the polyvalent carboxylic acid or anhydride thereof to be reacted therewith, for example, maleic acid, Succinic acid,
Polycarboxylic acids such as itaconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, chlorendic acid, methyltetrahydrophthalic acid, trimellitic acid, pyromellitic acid, and benzophenonetetracarboxylic acid, and acid anhydrides thereof. No.

Epoxy (meth) having a fluorene skeleton
The reaction between the acrylate and the polyvalent carboxylic acid or its anhydride can be carried out by a known method, but those having a carboxyl group generated from a carboxylic acid or an acid anhydride of three or more basic acids are preferable in view of alkali solubility. Therefore, it is preferable to use an acid containing a carboxylic acid or an acid anhydride of three or more basic acids. Those having an acid value of 10 mgKOH / g or less do not show sufficient alkali solubility.

The alkali-soluble resin having a fluorene skeleton is not limited to the above, but may be any resin having a polymerizable unsaturated bond and having a functional group such as a carboxyl group which provides alkali solubility. Good. This is because resins having a fluorene skeleton generally have excellent solvent solubility due to their bulky structure, and are also excellent in heat resistance and moisture resistance.

The photosensitive resin composition of the present invention may contain, in addition to the alkali-soluble resin having a fluorene skeleton, another polymerizable resin or monomer as long as the alkali-soluble property is maintained.

Examples of such a resin or monomer include those obtained by simply changing the skeleton of an alkali-soluble resin having a fluorene skeleton, for example, those obtained by replacing the fluorene skeleton with a bisphenol A skeleton, and acrylates. As acrylates, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate,
Those having a hydroxyl group such as butanediol mono (meth) acrylate and chlorohydroxypropyl (meth) acrylate, and, for example, allyl (meth) acrylate, butoxyethyl (meth) acrylate, butoxytriethylene glycol (meth) acrylate, t-butylamino Ethyl (meth) acrylate, caprolactone (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyanoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylamino (meth) acrylate, ethoxyethyl (meth) acrylate , Ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) Acrylate, stearyl (meth) acrylate, succinic acid (meth) acrylate, methacryloxypropyltrimethoxysilane, methoxyethyl (meth) acrylate, cyclodecatriene (meth) acrylate, glycerol (meth) acrylate, glycidyl (meth) acrylate, isocyanate Aliphatic (meth) acrylates such as ethyl (meth) acrylate, heptadecafluoro (meth) acrylate, octafluoropentyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, trifluoroethyl (meth) acrylate, and dibromopropyl (meth) acrylate And cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isoborny Alicyclic modified (meth) acrylates such as (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and morpholine (meth) acrylate, and, for example, phenoxyethyl (meth) acrylate, phenoxyhydroxypropyl (meth) acrylate, nonylphenoxy Aromatic (meth) such as polypropylene glycol (meth) acrylate, phenyl (meth) acrylate, phthalic acid (meth) acrylate, and benzyl (meth) acrylate
Acrylates, for example, phenoxylated phosphoric acid (meth)
Phosphorus-containing (meth) acrylates such as acrylate, phosphoric acid (meth) acrylate, butoxylated phosphoric acid (meth) acrylate, octoxylated phosphoric acid (meth) acrylate, and water-soluble (e.g., sodium sulfonate (meth) acrylate) Meth) acrylates and, for example, vinyl acetate, vinylcaprolactam, vinylpyrrolidone,
Monofunctional compounds such as vinyl compounds such as styrene are exemplified.

Also, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, hexanediol (meth) acrylate, long-chain aliphatic di (meth) acrylate, neopentyl glycol di (meth) acrylate, neohydroxypivalate Pentyl glycol di (meth) acrylate, stearic acid-modified pentaerythritol di (meth) acrylate, propylene di (meth) acrylate, glycerol (meth) acrylate, triethylene glycol di (meth)
Acrylate, tetraethylene glycol di (meth) acrylate, triethylene glycol divinyl ether, tetramethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, polyethylene glycol di (meth) Acrylate, polypropylene di (meth) acrylate, triglycerol di (meth) acrylate, neopentyl glycol-modified trimethylolpropane di (meth) acrylate, allylated cyclohexyldi (meth) acrylate, methoxylated cyclohexyldi (meth) acrylate, acrylated Isocyanurate, bis (acryloxyneopentyl glycol) adipate, bisphenol A di (meth) acrylate,
Tetrabromobisphenol A di (meth) acrylate, bisphenol S di (meth) acrylate, butanediol di (meth) acrylate, phthalic di (meth) acrylate
Bifunctional compounds such as acrylate, di (meth) acrylate phosphate, zinc di (meth) acrylate, divinylbenzene, and divinyl ether are exemplified.

Further, trimethylolpropane tri (meth) acrylate, trimethylol ethane tri (meth)
Acrylate, glycerol tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, tri (meth) acrylate phosphate, tris (acryloxyethyl) Isocyanurate, tris (methacryloxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetraacrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol mono Hydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, alkyl-modified dipenta Risuri penta (meth) acrylate, urethane tri (meth) acrylate, ester tri (meth) acrylate, urethane hexa (meth)
Acrylate, ester hexa (meth) acrylate,
Examples include trifunctional or higher functional compounds such as trivinyl ether and hexadivinyl ether.

Further, caprolactone, propylene oxide, and ethylene oxide modified products of all the compounds having an ethylenically unsaturated group described above can also be used.

In particular, in order to increase the sensitivity, a resin or monomer having at least two (bifunctional), more preferably at least three (trifunctional) double bonds in one molecule is polymerizable. It is also preferred. These compounds may be used in combination of two or more of the above compounds.

The mixing ratio of the above resin and monomer is in the range of 10 to 300 parts by weight based on 100 parts by weight of the alkali-soluble resin having a fluorene skeleton, and is determined in consideration of alkali solubility, curability, solvent resistance and the like. Good. In general, if the amount of trifunctional or higher polyfunctional acrylate is small, curing does not proceed sufficiently and the exposed part is eluted. If too large, the unexposed part can be developed, and tack-free depending on the degree of polymerization and the structure of the acid anhydride. There is a risk of loss of sex.

In the photosensitive resin composition of the present invention, as a photopolymerization initiator to be blended as an essential component, for example, benzoin, benzyl, benzoin methyl ether, benzoin isopropyl ether, acetophenone, 2,2-dimethoxy-2-phenyl Acetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylton, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1- ON, N, N
-Dimethylaminoacetophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, acetophenone dimethyl ketal, benzophenone, methylbenzophenone, 2-trichloromethyl-5- (p-methoxystyryl) -1,3,4-oxadiazole, 4,4′-bisdiethylaminobenzophenone, 2-trichloromethyl-S-triazine, 2,4
Radical-generating compounds such as dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, triarylphosphon oxide (TPO) and Michler's ketone, and cations such as triarylsulfonium salts and diaryliodonium salts Generating types can be mentioned. These may be used alone or in combination of two or more.

As these photopolymerization initiators, known photosensitizers such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, triethanolamine and triethylamine can be used alone or in combination. You may use it in combination with 2 or more types.

The amount of the photopolymerization initiator to be used is 0.1% in the solid content (including the monomer and excluding the solvent) in the photosensitive resin composition.
It is 5 to 10% by weight, preferably 1 to 5% by weight. 10
When the content exceeds% by weight, the light absorption ratio increases, and light does not penetrate to the lower part.

An epoxy resin can be added to the photosensitive resin composition of the present invention for the purpose of further improving adhesion and alkali resistance. Examples of the compound having an epoxy group include phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, alicyclic epoxy resin, etc. And a compound having at least one epoxy group such as phenylglycidyl ether, p-butylphenol glycidyl ether, triglycidyl isocyanurate, diglycidyl isocyanurate, allyl glycidyl ether, and glycidyl methacrylate. This blending amount is also determined within a range that maintains alkali solubility.

Organic Filler Organic filler to be incorporated as an essential component in the photosensitive resin composition of the present invention includes not only a filler mainly composed of an organic polymer but also an organic-inorganic composite filler. As an organic-inorganic composite filler,
A mixed filler obtained by mixing an inorganic material with an organic polymer, a material obtained by coating the surface of an inorganic material core with an organic polymer, or a material obtained by coating the surface of an organic polymer core with an inorganic material, may be used. Also, those containing 50% by weight or more, preferably 70% by weight or more of an organic polymer are good. And, it is preferable that these organic fillers are not substantially attacked by a weak acid or a weak alkali.
Those having excellent alkali resistance are preferred.

The organic polymer constituting the organic filler may be either a thermoplastic resin or a thermosetting resin. When the organic polymer is a thermoplastic resin, it is preferable that the organic polymer is cross-linked and modified with a cross-linking agent such as divinylbenzene or divinyl biphenyl from the viewpoint of heat resistance.
g) is preferably 170 ° C. or higher. Examples of the thermoplastic resin include (meth) acrylic resin, polystyrene, polypropylene, polyester, polyacetal, and polycarbonate. Examples of the thermosetting resin include epoxy resin, melamine resin, phenol resin, and diallyl phthalate resin. Can be One of these organic polymers may be used alone, or two or more thereof may be used in combination. Examples of the inorganic substance used in the organic-inorganic composite filler include calcium carbonate, titanium oxide, and the like. These are also coated with the organic polymer and have the above-described acid resistance and alkali resistance on the surface. Good.

The organic filler is dispersed in the cured resin matrix even after the photosensitive resin composition has been cured. However, when the cured resin is treated with a roughening liquid, the organic filler does not change and the cured resin has priority. Swelling and oxidative consumption. Then, the organic filler taken in the cured product falls off, and a dent is generated there. These depressions exert an anchoring effect on the plating to enhance the adhesion. Although the principle by which good depressions are obtained in the present invention is not always clear, the present inventors use a resin having a fluorene skeleton as the alkali-soluble resin, so that the solvent swelling or oxidative depletion with respect to the roughening solution is reduced. It is considered that the organic filler is easy to come off because it is higher than the organic filler.

Observation of the surface of the organic filler after the roughening treatment revealed that the particle size, the particle size distribution, and the compounding amount of the organic filler had optimum ranges. Normal,
In the roughening process, the organic filler near the surface of the insulating layer falls off, and the plated copper enters the formed dents, thereby exhibiting the anchor effect. The particle diameter of the filler specified in the present invention is 5 to 20 μm, preferably 8 to 12 μm. Since there is a relationship between the particle diameter and the diameter of the depression, a particle diameter that gives the depression in a range that maximizes the anchor effect is selected.

The distribution of the particle size of the filler is also important. The particle size distribution defined in the present invention has a coefficient of variation of 5
0% or less, preferably 15% or less. Here, the coefficient of variation is represented by the formula of (standard deviation value / average particle diameter) × 100%. If the coefficient of variation exceeds 50%, the resulting cavities are likely to be formed by connecting several particles, and the adhesion strength is reduced. On the other hand, when a material having a low variation coefficient, that is, a material having a uniform particle diameter is used, a regular hemispherical dent is formed on the surface of the insulating layer. As long as the coefficient of variation is 50% or less, a commercially available product may be used as it is. However, by using a known means such as air classification, sedimentation separation, or sieving, a filler having a low coefficient of variation is used to obtain an anchor effect. Can be increased.

The amount of the filler is 10 to 50% by weight, preferably 20 to 50% by weight, based on the solid content of the photosensitive resin composition.
４０40% by weight. If the amount of the filler is less than 10% by weight, the number of anchor points is small, and the adhesion strength is not obtained. If it exceeds 50% by weight, the strength of the resin cured product that will become the insulating layer will decrease.

The photosensitive resin composition of the present invention may further contain, in addition to the organic filler, an inorganic filler, for example, silica, in order to improve the low thermal expansion, elastic modulus and low moisture absorption of the cured product.
One or more of alumina, titanium oxide, boron nitride and the like may be blended.

The photosensitive resin composition of the present invention may further contain, if necessary, additives such as an epoxy resin curing accelerator, a polymerization inhibitor, a plasticizer, a leveling agent and an antifoaming agent, together with the above essential components. Can be blended. Examples of the epoxy resin curing accelerator include amine compounds, imidazole compounds, carboxylic acids, phenols, quaternary ammonium salts, and methylol group-containing compounds.
Examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert
-Butylcatechol, phenothiazine and the like. Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, and tricresyl. Examples of the antifoaming agent and the leveling agent include, for example, silicon-based, fluorine-based, and acrylic-based compounds.

In addition, the photosensitive resin composition of the present invention includes:
If necessary, a solvent can be added to adjust the viscosity. The solvent is not particularly limited as long as it dissolves the resin component and does not react with the resin component and the additive.

As a developing solution suitable for subjecting the photosensitive resin composition of the present invention to curing a desired portion with light or radiation and then developing the uncured portion with alkali, for example, an aqueous solution of an alkali metal carbonate, An aqueous solution of a hydroxide of a metal or an alkaline earth metal may, for example, be mentioned. In particular, a fine image can be precisely developed by using a weakly alkaline aqueous solution of about 1 to 3% by weight of an alkali metal carbonate such as sodium carbonate, potassium carbonate, and lithium carbonate. This alkali development may be performed at 10 to 50 ° C., preferably 20 to 40 ° C., using a commercially available developing machine or ultrasonic cleaning machine.

Light sources suitable for photocuring the photosensitive resin composition of the present invention include, for example, lamps such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, and a metal halide lamp. Further, the photosensitive resin composition of the present invention may be cured not only by light but also by radiation. further,
Curing can be accelerated by heat.

An example of a method for producing a multilayer printed wiring board using the photosensitive resin composition of the present invention will be described. First, apply an etching resist on the copper of the surface copper clad laminate,
After exposing, developing and printing the circuit, unnecessary copper other than the circuit is removed to form a first conductor layer. A photosensitive resin composition is applied thereon to form a resin layer, and exposure and development are performed using a photomask so that a via hole penetrating the upper and lower layers is formed. Next, the remaining resin portion is post-cured, and the resin is completely cured to form an insulating layer. The entire surface of the insulating layer is treated with a roughening solution such as a desmear solution such as a permanganate solution to roughen the surface, and the roughened surface is subjected to electroless plating and electrolytic plating to form a conductor layer. This is annealed to remove distortion inside the conductor layer. Next, an etching resist is applied to the surface of the conductor layer, the circuit is exposed and developed, printed, and unnecessary copper other than the circuit is removed to form a second conductor layer. This operation is sequentially repeated to obtain a multilayer printed wiring board.

In order to plate the insulating layer formed of the cured resin, a surface roughening treatment is performed, which can be performed by a known method such as an acid or alkali treatment, an oxidizing agent treatment, and polishing. Examples of the roughening solution used for the purpose of the acid or alkali treatment include a mineral acid aqueous solution such as sulfuric acid, hydrochloric acid, and nitric acid, and an alkaline aqueous solution such as sodium hydroxide. The roughening solution used for the purpose of the oxidizing agent treatment includes, for example, an aqueous solution of permanganate. Particularly preferred roughening solution is an organic solvent known as an agent for desmearing printed wiring boards-an aqueous alkaline solution and a permanganate-
Commercially available chemicals composed of an aqueous alkaline solution and a manganese remover (neutralizing agent) can be used. By sequentially treating the insulating layer formed using the resin composition for a printed board of the present invention with one or more such roughening solutions, preferably two or more roughening solutions including an aqueous alkali solution and an aqueous acid solution, The organic filler exposed on the surface falls off, and the adhesion to the conductive layer formed in a later step is significantly increased. If the surface is polished with an abrasive or the like in advance to remove or peel off part of the resin in order to promote the effect of the roughening liquid, the penetration rate of the roughening liquid is improved.

For the formation of the conductor layer, conventionally known electroless plating is preferably performed, and furthermore, electrolytic plating is performed to obtain a desired thickness of the conductor layer. Copper is generally used as the metal for the conductor layer, but nickel, gold, and the like can also be used. Alternatively, only electroless plating may be used.

Annealing is preferably performed to reduce the strain in the conductor layer after plating. In this case, the annealing temperature is set to be equal to or higher than the post-cure temperature of the resin, and if the temperature is the same, the annealing is performed for a long time. Is good. Preferably, the annealing temperature is at least 10 ° C. higher than the post-curing temperature of the resin, and the processing time is equal to or more than that. By doing so, the adhesion strength between the conductor layer and the insulating layer is further improved.

[0045]

Embodiments of the present invention will be described below. In the examples, “parts” indicates “parts by weight”. Examples 1 to 4, Comparative Examples ₁ and ₂ 231 parts of an epoxy resin (epoxy equivalent 231 manufactured by Nippon Steel Chemical Co., Ltd.) obtained by epoxidizing bisphenolfluorene in which R ₁ and R ₂ are hydrogen in the general formula (1) 72 parts of acrylic acid was reacted until the acid value became 2.0 mg KOH / g to obtain 303 parts of an epoxy acrylate, which was reacted with 38 parts of tetrahydrophthalic anhydride and 73.5 parts of biphenyltetracarboxylic anhydride. Thus, an alkali-soluble resin having an inherent viscosity of 0.2 dl / g and having a fluorene skeleton (resin A) was obtained.

The photosensitive resin composition (solid content excluding organic filler: 50%, viscosity at 23 ° C .: 20
0 cp) was prepared. The average particle size and particle size distribution of the organic filler were measured using SALD-1100 manufactured by Shimadzu Corporation. The average diameter of the filler in Table 1 is shown in μm, and the coefficient of variation is shown in%. Resin A: 30 parts Tetramethylbiphenyl epoxy resin: 6 parts (Epicoat YX4000 manufactured by Yuka Shell) Polyfunctional acrylate: 13 parts (TMPTA manufactured by Nippon Kayaku) Organic filler: 20 parts (described in Table 1) Sensitizer: 0 .04 parts (Michler's ketone) Photopolymerization initiator: 1 part (Irgacure 651 manufactured by Ciba Geigy) Solvent *: 50 parts * Propylene glycol monomethyl ether acetate

On a commercially available 10 cm square single-sided copper-clad FR-4 glass fiber-epoxy resin-based substrate, the above-mentioned photosensitive resin composition was applied to a thickness of 40 μm by spin coating, dried, and then dried. Photocuring was performed by applying a photomask having a predetermined pattern, developed with an aqueous solution of sodium carbonate, and then cured by post-curing. After roughening the surface, the surface was immersed in a solution containing a plating catalyst, copper plating was performed on the entire surface by an electroless plating method and an electrolytic plating method, and finally, a sample was produced by annealing.
The conditions are as follows. Curing condition of the photosensitive resin composition: After drying at 100 ° C. for 10 minutes, exposure to 200 mJ / cm ² with a 500 W high-pressure mercury lamp Post cure condition: 170 ° C. for 60 minutes under a nitrogen atmosphere Electrobright standard condition of liquid (permanganate solution) Etching temperature 70 degrees, immersion time 10 minutes, polishing with abrasive powder Electroless copper plating condition: Okuno Pharmaceutical Co., Ltd. OPC process M standard condition Electrolytic copper plating condition: Uemura Kogyo Bright PY-61 standard conditions Copper plating film thickness 35 μm Annealing condition after plating: 180 ° C. for 60 minutes in a nitrogen atmosphere (160 ° C. for 60 minutes only in Example 4)

Table 1 shows the results of measuring the adhesion strength (peel strength) between the resin layer and the conductor layer based on JIS C-6481 for the samples manufactured in Examples 1 to 4 and Comparative Examples 1 and 2. The adhesion strength is shown in kg / cm.

[0049]

[Table 1]

* 1: Technopolymer MBX-12, manufactured by Sekisui Plastics Co., Ltd. * 2: Classified product of Technopolymer MBX-12, manufactured by Sekisui Plastics * 3: Technopolymer SBX-8, manufactured by Sekisui Plastics

Example 5 In the same experiment as in Examples 1 to 3, a sample was manufactured by changing the average diameter of the organic filler to about 10 μm, the variation coefficient and the mixing ratio, and the adhesion strength (peel strength) was measured. The result is shown in FIG.

[0052]

When the cured product obtained by using the photosensitive resin composition of the present invention is plated, the adhesion is improved. When an insulating layer is formed on a multilayer printed wiring board, particularly a build-up multilayer printed wiring board using this, heat resistance,
A multilayer printed wiring board having excellent moisture resistance reliability and excellent adhesion strength between the insulating layer and the conductor layer can be manufactured.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a variation coefficient of an organic filler and an adhesion strength.

Claims (6)

[Claims] 1. An alkali-soluble resin matrix comprising:
In a resin composition containing an organic filler and a photopolymerization initiator as essential components, at least a part of the alkali-soluble resin is an alkali-soluble resin having a fluorene skeleton, and the content of the organic filler is 100 parts by weight of the alkali-soluble resin. A photosensitive resin composition, characterized in that the organic filler has an average particle diameter of 5 to 20 μm and a coefficient of variation of the particle diameter of 50% or less. 2. The coefficient of variation of the particle size of the organic filler is 1
The photosensitive resin composition according to claim 1, which is at most 5%. 3. The photosensitive resin composition according to claim 1, wherein the organic filler is a substantially acid- or alkali-resistant particle made of a cross-linked modified resin of a thermoplastic resin or a thermosetting resin. 4. An epoxy resin obtained by epoxidizing a bisphenol compound represented by the following general formula (1) with an alkali-soluble resin having a fluorene skeleton and (meth)
4. An epoxy (meth) acrylate acid adduct having a fluorene skeleton obtained by reacting a polycarboxylic acid or an anhydride thereof with an epoxy (meth) acrylate obtained by reacting with acrylic acid. A photosensitive resin composition according to any one of the above. Embedded image (Wherein, R ₁ and R ₂ represent hydrogen, an alkyl group having 1 to 5 carbon atoms, or halogen) 5. A multilayer printed wiring board comprising an insulating layer formed from a cured product of the photosensitive resin composition according to claim 1. 6. A method for producing a multilayer printed wiring board using the photosensitive resin composition according to claim 1 by a build-up method involving post-curing annealing and resin post-plating. Wherein the annealing is performed under more severe conditions than post-cure of a resin.