JP5454009B2 - Curable resin composition, cured product thereof, and printed wiring board - Google Patents

Description

  The present invention is a curable resin composition excellent in heat resistance and low thermal expansion of the resulting cured product, and can be suitably used for printed wiring boards, semiconductor encapsulants, paints, casting applications, etc. The present invention relates to a wiring board.

  Phenolic resins are used in adhesives, molding materials, paints, photoresist materials, color developing materials, epoxy resin raw materials, epoxy resin curing agents, etc., as well as excellent heat resistance and moisture resistance in the resulting cured products. As a curable resin composition mainly composed of phenol resin itself, or as a curable resin composition using epoxidized resin or epoxy resin as a curing agent, semiconductor encapsulant and printed wiring Widely used in electrical and electronic fields such as insulating materials for plates.

  Among these various applications, in the field of printed wiring boards, along with the trend toward miniaturization and higher performance of electronic equipment, there is a significant trend toward higher density due to narrower wiring pitches in semiconductor devices. As a mounting method, a flip chip connection method in which a semiconductor device and a substrate are joined by solder balls is widely used. In this flip-chip connection method, a solder ball is placed between a wiring board and a semiconductor, and the whole is heated and melt bonded to form a so-called reflow semiconductor mounting method. Therefore, the wiring plate itself is exposed to a high heat environment during solder reflow. However, due to the thermal contraction of the wiring board, a large stress is generated in the solder balls connecting the wiring board and the semiconductor, resulting in a problem that the wiring connection is poor. Therefore, an insulating material used for a printed wiring board is required to have a low thermal expansion coefficient.

In addition, in recent years, high melting point solder that does not use lead has become mainstream due to laws and regulations for environmental problems, etc., and this lead-free solder has a use temperature that is about 20-40 ° C. higher than conventional eutectic solder. Therefore, the curable resin composition is required to have higher heat resistance than ever before.
Thus, the curable resin composition used for the insulating material of the printed wiring board is required to have high heat resistance and low thermal expansibility, and a phenol resin material that can meet such a demand is desired.

  In order to meet such a demand, for example, a naphthol resin obtained by reacting naphthol and formaldehyde, and a phenol resin partially using phenol in combination with the naphthol is known (Patent Document 1 below). reference). However, since such a phenolic resin has a large amount of formaldehyde used at the time of synthesis, the resulting phenolic resin has a high viscosity and fluidity is lowered. Therefore, when this is used as a curing agent for epoxy resins, the crosslinking density cannot be increased during curing, and sufficient low thermal expansion cannot be obtained. Also known are phenol resins using naphthol, phenol and formaldehyde in an excess of naphthol relative to phenol, or naphthol novolak resins not using phenol (see Patent Document 2 below). However, what is specifically disclosed as the former phenol resin is only one having a molar ratio of naphthol to phenol (N / P) of 10 or less, the amount of phenol is relatively large, and a decrease in heat resistance is avoided. I can't. On the other hand, the latter naphthol novolak resin not using phenol was not satisfactory in terms of low thermal expansion, although an effect of improving the heat resistance of the resulting cured product was recognized due to the rigidity of the skeleton.

Japanese Examined Patent Publication No. 62-20206 Japanese Patent No. 3198530

  Therefore, the problem to be solved by the present invention is to provide a curable resin composition that exhibits excellent heat resistance and low thermal expansion, a cured product thereof, and a printed wiring board that is excellent in heat resistance and low thermal expansion. .

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained phenolic resins obtained by reacting naphthol, phenols and formaldehyde under specific conditions, and have excellent heat resistance and low thermal expansion. As a result, the present invention was completed.

That is, the present invention is a curable resin composition comprising an epoxy resin (A) and a phenol resin (B) as essential components, wherein the phenol resin (B)
Naphthol (N), phenols (P) and formaldehyde (F)
The molar ratio [naphthol (N) / phenols (P)] is a ratio of 11/1 to 100/1, and the molar ratio [formaldehyde (F) / (naphthol (N) + phenols (P)]. ) Is obtained by polycondensation reaction at a ratio of 0.6 to 0.8.

  The present invention further relates to a cured product obtained by curing reaction of the curable resin composition.

  The present invention can be obtained by further impregnating a reinforced resin composition with an organic solvent (C) and varnishing the resin composition, impregnating the reinforcing base material, and stacking the copper foil thereon. The present invention relates to a printed wiring board.

  According to the present invention, it is possible to provide a curable resin composition that exhibits excellent heat resistance and low thermal expansion, a cured product thereof, and a printed wiring board that is excellent in heat resistance and low thermal expansion.

Hereinafter, the present invention will be described in detail.
Various epoxy resins can be used as the epoxy resin (A) used in the present invention. For example, bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; biphenyl type epoxy resin, tetramethylbiphenyl Type epoxy resins, biphenyl type epoxy resins; phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, epoxidized products of condensates of phenols and aromatic aldehydes having phenolic hydroxyl groups, biphenyl novolacs Type novolak type epoxy resin; triphenylmethane type epoxy resin; tetraphenylethane type epoxy resin; dicyclopentadiene-phenol addition reaction type epoxy resin; Ruaralkyl type epoxy resin; naphthol novolak type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol co-condensed novolac type epoxy resin, naphthol-cresol co-condensed novolac type epoxy resin, diglycidyloxynaphthalene, 1,1-bis (2, 7-diglycidyloxy-1-naphthyl) epoxy resins having a naphthalene skeleton in the molecular structure such as alkanes; phosphorus atom-containing epoxy resins. Moreover, these epoxy resins may be used independently and may mix 2 or more types.

Here, as the phosphorus atom-containing epoxy resin, epoxidized product of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (hereinafter abbreviated as “HCA”), HCA and quinones Epoxy product of phenol resin obtained by reacting phenolic resin, epoxy resin obtained by modifying phenol novolac type epoxy resin with HCA, epoxy resin obtained by modifying cresol novolac type epoxy resin with HCA, and bisphenol A type epoxy resin using HCA and quinone Resin obtained by modification with a phenol resin obtained by reacting with a phenol, an epoxy resin obtained by modifying a bisphenyl A type epoxy resin with a phenol resin obtained by reacting an HCA with a quinone, etc. Is mentioned.
Among the above-described epoxy resins (A), an epoxy resin having a naphthalene skeleton in the molecular structure and an epoxy resin having a phosphorus atom in the molecular structure are particularly preferable from the viewpoint of heat resistance, and from the viewpoint of solvent solubility. Bisphenol type epoxy resins and novolac type epoxy resins are preferred.

  Next, the phenol resin (B) used in the present invention is used as a curing agent for the epoxy resin (A), and naphthol (N), phenols (P) and formaldehyde (F) are mixed in a molar ratio [ Naphthol (N) / phenols (P)] is a ratio of 11/1 to 100/1, and the molar ratio [formaldehyde (F) / (naphthol (N) + phenols (P)) is 0. It is obtained by a polycondensation reaction at a ratio of 6 to 0.8. Here, when the molar ratio [naphthol (N) / phenols (P)] is less than 11, the amount of phenols (P) increases, resulting in a decrease in heat resistance. On the other hand, if it exceeds 100, the heat resistance is good, but the viscosity is remarkably increased, so that sufficient curability cannot be obtained, resulting in a low linear expansion coefficient. In view of these performance balances, the molar ratio is particularly preferably in the range of 11/1 to 30/1. When the phenol component amount is increased with respect to the naphthol component amount, the heat resistance is usually lowered, but in the present invention, when the reaction is carried out with the phenol amount within the above range, the heat resistance is not lowered and the low line is not caused. An expansion coefficient can be realized.

  Further, when the molar ratio [formaldehyde (F) / (naphthol (N) + phenols (P)) is less than 0.6, excellent heat resistance cannot be expressed, and 0.8 When exceeding, the fluidity | liquidity fall of the obtained phenol resin itself will be caused, the reactivity will fall, the bridge | crosslinking in hardened | cured material will become insufficient, and sufficient low linear expansion coefficient will not be obtained.

  The phenol resin (B) can be obtained by charging naphthol (N), phenols (P), and formaldehyde (F) into the reaction vessel at the predetermined ratio described above and reacting them together under an acid catalyst. .

  Examples of naphthol (N) used here include α-naphthol, β-naphthol, and compounds in which a methyl group, an ethyl group, a methoxy group, or the like is substituted with a nucleus. Of these, α-naphthol is particularly preferred from the viewpoint of excellent reactivity.

  Phenols (P) that can be used here include phenol, cresol, pt-butylphenol, and the like. Among these, phenol or cresol is preferable from the viewpoint of excellent heat resistance of the cured product obtained.

  Examples of the formaldehyde source of formaldehyde (F) include formalin, paraformaldehyde, trioxane and the like. Here, it is preferable that formalin is 30-60 mass% formalin from the point of water dilutability and workability | operativity at the time of manufacture.

  Acid catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, organic acids such as methanesulfonic acid, p-toluenesulfonic acid and oxalic acid, Lewis acids such as boron trifluoride, anhydrous aluminum chloride and zinc chloride. Is mentioned. The amount used is preferably in the range of 0.1 to 5% by weight with respect to the total weight of the charged raw materials.

  Moreover, it is preferable from the point which is excellent in the reaction temperature that the reaction temperature is the range of 80-150 degreeC.

  The phenol resin (B) thus obtained is usually excellent in fluidity, and usually has a melt viscosity at 180 ° C. in the range of 500 to 5000 mPa · s. Further, the softening point is preferably in the range of 110 to 150 from the viewpoint that the linear expansion coefficient in the cured product becomes lower. Furthermore, the product of the phenol resin (B) is usually a random polymer.

  The blending ratio of the epoxy resin (A) and the phenol resin (B) detailed above is equivalent ratio of epoxy group in the epoxy resin (A) and phenolic hydroxyl group in the phenol resin (B) (epoxy group / hydroxyl group). Is preferably a ratio of 1 / 0.7 to 1 / 1.5 from the viewpoint that the linear expansion coefficient in the cured product becomes lower.

The curable resin composition of the present invention uses the above-described phenol resin (B) as a curing agent for epoxy resin, and optionally uses another curing agent for epoxy resin (B ′) as necessary. May be. Examples of other curing agents for epoxy resin (B ′) that can be used here include various known curing agents such as amine compounds, amide compounds, acid anhydride compounds, phenol compounds, and the like. Specifically, examples of the amine compound include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, and guanidine derivative. Examples of the amide compound include dicyandiamide. And polyamide resins synthesized from dimer of linolenic acid and ethylenediamine. Examples of acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, and tetrahydrophthalic anhydride. Acid, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc., and phenolic compounds include phenol novolac resin, cresol novolac resin Aromatic hydrocarbon formaldehyde resin modified phenolic resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin (Zyloc resin), naphthol aralkyl resin, trimethylol methane resin, tetraphenylol ethane resin, naphthol novolak resin, naphthol-phenol co-condensation Novolac resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin (polyhydric phenol compound with phenol nucleus linked by bismethylene group), biphenyl-modified naphthol resin (polyvalent naphthol compound with phenol nucleus linked by bismethylene group) , Aminotriazine-modified phenolic resin (polyhydric phenol compound in which phenol nucleus is linked with melamine, benzoguanamine, etc.) and alkoxy group-containing aromatic ring-modified novo Examples thereof include polyhydric phenol compounds such as rack resin (polyhydric phenol compound in which a phenol nucleus and an alkoxy group-containing aromatic ring are linked with formaldehyde).

  When using the other curing agent for epoxy resin (B ′) described above, the amount used is equivalent ratio of active hydrogen in the curing agent for epoxy resin (B ′) and phenolic hydroxyl group in the phenol resin (B). It is preferable that (active hydrogen / hydroxyl group) is in a range of 1/10 to 5/1.

  Moreover, a hardening accelerator can also be suitably used together with the curable resin composition of this invention as needed. Various curing accelerators can be used, and examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, and amine complex salts. In particular, when used as a semiconductor sealing material, it is excellent in curability, heat resistance, electrical characteristics, moisture resistance reliability, etc., so that 2-ethyl-4-methylimidazole is used for imidazole compounds, and triphenylphosphine is used for phosphorus compounds. For fins and tertiary amines, 1,8-diazabicyclo- [5.4.0] -undecene (DBU) is preferred.

  When adjusting the curable resin composition of this invention explained in full detail above to the varnish for printed wiring boards, it is preferable to mix | blend an organic solvent other than said each component. Examples of the organic solvent that can be used here include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, etc. The amount used can be appropriately selected depending on the application. For example, in printed wiring board applications, it is preferable to use a polar solvent having a boiling point of 160 ° C. or lower, such as methyl ethyl ketone, acetone, dimethylformamide, and the non-volatile content of 40 to 80% by mass. It is preferable to use in the ratio which becomes. On the other hand, in build-up adhesive film applications, as organic solvents, for example, ketones such as acetone, methyl ethyl ketone, cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, It is preferable to use carbitols such as cellosolve and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like, and the nonvolatile content is 30 to 60% by mass. It is preferable to use in proportions.

  Moreover, in order to exhibit the flame retardancy, the thermosetting resin composition may contain a non-halogen flame retardant that substantially does not contain a halogen atom, for example, in the field of printed wiring boards.

  Examples of the non-halogen flame retardants include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organic metal salt flame retardants. The flame retardants may be used alone or in combination, and a plurality of flame retardants of the same system may be used, or different types of flame retardants may be used in combination.

  As the phosphorus flame retardant, either inorganic or organic can be used. Examples of the inorganic compounds include red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, ammonium phosphates such as ammonium polyphosphate, and inorganic nitrogen-containing phosphorus compounds such as phosphate amide. .

  The red phosphorus is preferably subjected to a surface treatment for the purpose of preventing hydrolysis and the like. Examples of the surface treatment method include (i) magnesium hydroxide, aluminum hydroxide, zinc hydroxide, water A method of coating with an inorganic compound such as titanium oxide, bismuth oxide, bismuth hydroxide, bismuth nitrate or a mixture thereof; (ii) an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide, titanium hydroxide; and A method of coating with a mixture of thermosetting resins such as phenolic resin, and (iii) thermosetting of phenolic resin on a coating of an inorganic compound such as magnesium hydroxide, aluminum hydroxide, zinc hydroxide or titanium hydroxide. For example, a method of double coating with a resin may be used.

  Examples of the organic phosphorus compound include, for example, general-purpose organic phosphorus compounds such as phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphorane compounds, organic nitrogen-containing phosphorus compounds, and 9,10- Dihydro-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,5-dihydrooxyphenyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide, 10- (2,7- Examples thereof include cyclic organophosphorus compounds such as dihydrooxynaphthyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide, and derivatives obtained by reacting them with compounds such as epoxy resins and phenol resins.

  The blending amount thereof is appropriately selected depending on the type of the phosphorus-based flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. In 100 parts by mass of curable resin composition containing all of halogen-based flame retardant and other fillers and additives, 0.1 to 2.0 parts by mass of red phosphorus is used as a non-halogen flame retardant. It is preferable to mix in the range, and when using an organophosphorus compound, it is preferably mixed in the range of 0.1 to 10.0 parts by mass, particularly in the range of 0.5 to 6.0 parts by mass. It is preferable to do.

  In addition, when using the phosphorous flame retardant, the phosphorous flame retardant may be used in combination with hydrotalcite, magnesium hydroxide, boric compound, zirconium oxide, black dye, calcium carbonate, zeolite, zinc molybdate, activated carbon, etc. Good.

  Examples of the nitrogen-based flame retardant include triazine compounds, cyanuric acid compounds, isocyanuric acid compounds, phenothiazines, and the like, and triazine compounds, cyanuric acid compounds, and isocyanuric acid compounds are preferable.

  Examples of the triazine compound include melamine, acetoguanamine, benzoguanamine, melon, melam, succinoguanamine, ethylene dimelamine, melamine polyphosphate, triguanamine, and the like, for example, (i) guanylmelamine sulfate, melem sulfate, sulfate Aminotriazine sulfate compounds such as melam, (ii) co-condensates of phenols such as phenol, cresol, xylenol, butylphenol and nonylphenol with melamines such as melamine, benzoguanamine, acetoguanamine and formguanamine and formaldehyde, (iii) (Ii) a mixture of a co-condensate of (ii) and a phenol resin such as a phenol formaldehyde condensate, (iv) a mixture of (ii) and (iii) further modified with paulownia oil, isomerized linseed oil, etc. .

  Specific examples of the cyanuric acid compound include cyanuric acid and cyanuric acid melamine.

  The compounding amount of the nitrogen-based flame retardant is appropriately selected according to the type of the nitrogen-based flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. For example, an epoxy resin, It is preferable to mix in the range of 0.05 to 10 parts by mass in 100 parts by mass of the curable resin composition containing all of the curing agent, non-halogen flame retardant and other fillers and additives. It is preferable to mix | blend in the range of 1-5 mass parts.

  Moreover, when using the said nitrogen-type flame retardant, you may use together a metal hydroxide, a molybdenum compound, etc.

  The silicone flame retardant is not particularly limited as long as it is an organic compound containing a silicon atom, and examples thereof include silicone oil, silicone rubber, and silicone resin.

  The amount of the silicone-based flame retardant is appropriately selected depending on the type of the silicone-based flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. For example, an epoxy resin, It is preferable to mix in the range of 0.05 to 20 parts by mass in 100 parts by mass of the curable resin composition containing all of the curing agent, non-halogen flame retardant and other fillers and additives. Moreover, when using the said silicone type flame retardant, you may use a molybdenum compound, an alumina, etc. together.

  Examples of the inorganic flame retardant include metal hydroxide, metal oxide, metal carbonate compound, metal powder, boron compound, and low melting point glass.

  Specific examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, zirconium hydroxide and the like.

  Specific examples of the metal oxide include, for example, zinc molybdate, molybdenum trioxide, zinc stannate, tin oxide, aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, and cobalt oxide. Bismuth oxide, chromium oxide, nickel oxide, copper oxide, tungsten oxide and the like.

  Specific examples of the metal carbonate compound include zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate, aluminum carbonate, iron carbonate, cobalt carbonate, and titanium carbonate.

  Specific examples of the metal powder include aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, nickel, copper, tungsten, and tin.

  Specific examples of the boron compound include zinc borate, zinc metaborate, barium metaborate, boric acid, and borax.

Specific examples of the low-melting-point glass include, for example, Ceeley (Bokusui Brown), hydrated glass SiO ₂ —MgO—H ₂ O, PbO—B ₂ O ₃ system, ZnO—P ₂ O ₅ —MgO system, P ₂ O ₅ —B ₂ O ₃ —PbO—MgO, P—Sn—O—F, PbO—V ₂ O ₅ —TeO ₂ , Al ₂ O ₃ —H ₂ O, lead borosilicate, etc. The glassy compound can be mentioned.

  The amount of the inorganic flame retardant is appropriately selected depending on the type of the inorganic flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. For example, an epoxy resin, It is preferable to mix in the range of 0.5 to 50 parts by mass in 100 parts by mass of the curable resin composition in which all of the curing agent, non-halogen flame retardant and other fillers and additives are mixed. It is preferable to mix in the range of 30 parts by mass.

  Examples of the organic metal salt flame retardant include ferrocene, acetylacetonate metal complex, organic metal carbonyl compound, organic cobalt salt compound, organic sulfonic acid metal salt, metal atom and aromatic compound or heterocyclic compound or an ionic bond or Examples thereof include a coordinated compound.

  The amount of the organic metal salt flame retardant is appropriately selected depending on the type of the organic metal salt flame retardant, the other components of the curable resin composition, and the desired degree of flame retardancy. In 100 parts by mass of the curable resin composition in which all of epoxy resin, curing agent, non-halogen flame retardant and other fillers and additives are blended, it is preferably blended in the range of 0.005 to 10 parts by mass. .

  An inorganic filler can be mix | blended with the curable resin composition of this invention as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. When particularly increasing the blending amount of the inorganic filler, it is preferable to use fused silica. The fused silica can be used in either a crushed shape or a spherical shape. However, in order to increase the blending amount of the fused silica and suppress an increase in the melt viscosity of the molding material, it is preferable to mainly use a spherical shape. In order to further increase the blending amount of the spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. The filling ratio is preferably in the range of 0.5 to 50 parts by mass in 100 parts by mass of the curable resin composition. Moreover, when using for uses, such as an electrically conductive paste, electroconductive fillers, such as silver powder and copper powder, can be used.

  Various compounding agents, such as a silane coupling agent, a mold release agent, a pigment, an emulsifier, can be added to the curable resin composition of this invention as needed.

  The curable resin composition of the present invention can be obtained by uniformly mixing the above-described components. The curable resin composition of the present invention in which the epoxy resin of the present invention, a curing agent, and further, if necessary, a curing accelerator are blended can be easily made into a cured product by a method similar to a conventionally known method. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

  Applications for which the curable resin composition of the present invention is used include printed wiring board materials, resin casting materials, adhesives, interlayer insulation materials for build-up substrates, and adhesive films for build-ups. Among these various applications, in printed circuit boards, insulating materials for electronic circuit boards, and adhesive films for build-up, passive parts such as capacitors and active parts such as IC chips are embedded in so-called electronic parts. It can be used as an insulating material for a substrate. Among these, it is preferable to use for the printed wiring board material and the adhesive film for buildup from the characteristics, such as high heat resistance and low thermal expansibility.

  Here, in order to produce a printed circuit board from the curable resin composition of the present invention, the varnish-like curable resin composition containing the organic solvent (C) is further blended with the organic solvent (C) to obtain a varnish. A method of impregnating a reinforced resin composition into a reinforcing base material and stacking a copper foil to heat-press is mentioned. Examples of the reinforcing substrate that can be used here include paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, and glass roving cloth. If this method is described in further detail, first, the varnish-like curable resin composition is heated at a heating temperature corresponding to the solvent type used, preferably 50 to 170 ° C., thereby being a prepreg which is a cured product. Get. The mass ratio of the resin composition and the reinforcing substrate used at this time is not particularly limited, but it is usually preferable that the resin content in the prepreg is 20 to 60% by mass. Next, the prepreg obtained as described above is laminated by a conventional method, and a copper foil is appropriately stacked, and then subjected to thermocompression bonding at a pressure of 1 to 10 MPa at 170 to 250 ° C. for 10 minutes to 3 hours, A desired printed circuit board can be obtained.

  When the curable resin composition of the present invention is used as a resist ink, for example, a cationic polymerization catalyst is used as the curing agent (B) of the curable resin composition, and a pigment, talc, and filler are further added to the resist ink. A method for forming a resist ink cured product after coating on a printed circuit board by a screen printing method after an ink composition is used.

  When the curable resin composition of the present invention is used as a conductive paste, for example, a method of dispersing fine conductive particles in the curable resin composition to obtain a composition for anisotropic conductive film, liquid at room temperature And a paste resin composition for circuit connection and an anisotropic conductive adhesive.

  As a method for obtaining an interlayer insulating material for a build-up substrate from the curable resin composition of the present invention, for example, the curable resin composition appropriately blended with rubber, filler, etc., spray coating method on a wiring board on which a circuit is formed, After applying using a curtain coating method or the like, it is cured. Then, after drilling a predetermined through-hole part etc. as needed, it treats with a roughening agent, forms the unevenness | corrugation by washing the surface with hot water, and metal-treats, such as copper. As the plating method, electroless plating or electrolytic plating treatment is preferable, and examples of the roughening agent include an oxidizing agent, an alkali, and an organic solvent. Such operations are sequentially repeated as desired, and a build-up base can be obtained by alternately building up and forming the resin insulating layer and the conductor layer having a predetermined circuit pattern. However, the through-hole portion is formed after the outermost resin insulating layer is formed. In addition, a resin-coated copper foil obtained by semi-curing the resin composition on the copper foil is thermocompression-bonded at 170 to 250 ° C. on a circuit board on which a circuit is formed, thereby forming a roughened surface and plating treatment. It is also possible to produce a build-up substrate by omitting the process.

  The method for producing an adhesive film for buildup from the curable resin composition of the present invention is, for example, a multilayer printed wiring board in which the curable resin composition of the present invention is applied on a support film to form a resin composition layer. And an adhesive film for use.

  When the curable resin composition of the present invention is used for a build-up adhesive film, the adhesive film is softened under the temperature condition of the laminate in the vacuum laminating method (usually 70 ° C. to 140 ° C.), and simultaneously with the lamination of the circuit board, It is important to show fluidity (resin flow) that allows resin filling in via holes or through holes present in a circuit board, and it is preferable to blend the above-described components so as to exhibit such characteristics.

  Here, the diameter of the through hole of the multilayer printed wiring board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm. It is usually preferable to allow resin filling in this range. When laminating both surfaces of the circuit board, it is desirable to fill about 1/2 of the through hole.

  Specifically, the method for producing the adhesive film described above is, after preparing the varnish-like curable resin composition of the present invention, coating the varnish-like composition on the surface of the support film (Y), Further, it can be produced by drying the organic solvent by heating or blowing hot air to form the layer (X) of the curable resin composition.

  The thickness of the formed layer (X) is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

  In addition, the layer (X) in this invention may be protected with the protective film mentioned later. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches.

  The above-mentioned support film and protective film are made of polyolefin such as polyethylene, polypropylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyester such as polyethylene naphthalate, polycarbonate, polyimide, and further. Examples thereof include metal foil such as pattern paper, copper foil, and aluminum foil. In addition, the support film and the protective film may be subjected to a release treatment in addition to the mud treatment and the corona treatment.

  Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers. Moreover, it is preferable that the thickness of a protective film shall be 1-40 micrometers.

  The support film (Y) described above is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled after the adhesive film is heat-cured, adhesion of dust and the like in the curing process can be prevented. In the case of peeling after curing, the support film is usually subjected to a release treatment in advance.

  Next, the method for producing a multilayer printed wiring board using the adhesive film obtained as described above is, for example, when the layer (X) is protected by a protective film, after peeling these layers ( X) is laminated on one side or both sides of the circuit board so as to be in direct contact with the circuit board, for example, by a vacuum laminating method. The laminating method may be a batch method or a continuous method using a roll. Further, the adhesive film and the circuit board may be heated (preheated) as necessary before lamination.

The laminating conditions are preferably a pressure bonding temperature (laminating temperature) of 70 to 140 ° C. and a pressure bonding pressure of preferably 1 to 11 kgf / cm ² (9.8 × 10 ^{4 to} 107.9 × 10 ⁴ N / m ² ). Lamination is preferably performed under a reduced pressure of 20 mmHg (26.7 hPa) or less.

  The method for obtaining the cured product of the present invention may be based on a general curing method for a curable resin composition, but for example, the heating temperature condition may be appropriately selected depending on the kind of curing agent to be combined and the use. However, what is necessary is just to heat the composition obtained by the said method in the temperature range of about room temperature-250 degreeC.

  Therefore, by using the epoxy resin, the solvent solubility of the epoxy resin is dramatically improved, and when it is made into a cured product, heat resistance and a low coefficient of thermal expansion can be expressed, and it can be applied to the latest printed wiring board materials. . In addition, the epoxy resin can be easily and efficiently manufactured by the manufacturing method of the present invention, and a molecular design corresponding to the target level of performance described above becomes possible.

  Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” are based on mass unless otherwise specified. The melt viscosity and softening point at 180 ° C. were measured under the following conditions.

1) Melt viscosity at 180 ° C .: according to ASTM D4287 2) Softening point measurement method: according to JIS K7234

Synthesis example 1
A flask equipped with a thermometer, a dropping funnel, a condenser tube, a fractionating tube, and a stirrer was charged with α-naphthol 500 g (3.47 mol), orthocresol 30 g (0.28 mol), water 163 g, and oxalic acid 6 g. The mixture was stirred while raising the temperature from room temperature to 100 ° C. in 45 minutes. Subsequently, 199 parts (2.75 mol) of a 42% formalin aqueous solution was added dropwise over 1 hour. After completion of dropping, the mixture was further stirred at 100 ° C. for 1 hour, and then heated to 180 ° C. in 3 hours. After completion of the reaction, water remaining in the reaction system was removed under reduced pressure by heating to obtain 536 parts of compound (A-1). The obtained compound (A-1) had a softening point of 135 ° C. (B & R method), a melt viscosity of 3000 mPa · s, and a hydroxyl group equivalent of 151 g / equivalent. From the charging ratio, N / P = 12.5 and F / (N + P) = 0.73.

Synthesis example 2
To a flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer was added α-naphthol 500 g (3.47 mol), orthocresol 18.8 g (0.17 mol), water 163 g, and oxalic acid 6 g. The mixture was stirred and heated from room temperature to 100 ° C. in 45 minutes. Subsequently, 192 g (2.65 mol) of 42% formalin aqueous solution was added dropwise over 1 hour. After completion of dropping, the mixture was further stirred at 100 ° C. for 1 hour, and then heated to 180 ° C. in 3 hours. After completion of the reaction, water remaining in the reaction system was removed under reduced pressure by heating to obtain 518 g of compound (A-2). The obtained compound (A-2) had a softening point of 137 ° C. (B & R method), a melt viscosity of 3200 mPa · s, and a hydroxyl group equivalent of 153 g / equivalent. From the charging ratio, N / P = 20.0 and F / (N + P) = 0.73.

Comparative Synthesis Example 1
In a flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer, 137 parts (0.95 mole) α-naphthol, 5 parts (0.05 mole) paracresol, 20 parts water, 2 oxalic acids The mixture was stirred and heated from room temperature to 110 ° C. over 45 minutes. Subsequently, 73 parts (0.90 mol) of 37% formalin aqueous solution was added dropwise over 30 minutes. After completion of dropping, the mixture was further stirred at 110 ° C. for 90 minutes, and then heated to 200 ° C. in 3 hours. After completion of the reaction, water remaining in the reaction system was removed under reduced pressure by heating to obtain 148 parts of compound (A-3). The softening point of the obtained compound (A-3) was 165 ° C. (B & R method), and the hydroxyl group equivalent was 154 g / equivalent. The melt viscosity could not be measured at 180 ° C. From the charging ratio, N / P = 20.6 and F / (N + P) = 0.90.

Comparative Synthesis Example 2
A flask equipped with a thermometer, dropping funnel, condenser, fractionator, and stirrer was charged with 144 parts (1.00 mol) of α-naphthol, 20 g of water, and 2 g of oxalic acid, and the temperature was raised from room temperature to 110 ° C. in 45 minutes. Stir while warm. Subsequently, 73 g (0.90 mol) of 37% formalin aqueous solution was added dropwise over 30 minutes. After completion of dropping, the mixture was further stirred at 110 ° C. for 90 minutes, and then heated to 200 ° C. in 3 hours. After completion of the reaction, water remaining in the reaction system was removed under reduced pressure by heating to obtain 140 g of Compound (A-4). The softening point of the obtained compound (A-4) was 168 ° C. (B & R method), and the hydroxyl group equivalent was 155 g / equivalent. From the charging ratio, N / P = ∞ and F / (N + P) = 0.90.

Examples 1 and 2 and Comparative Examples 1 and 2
In accordance with the composition shown in Table 1 below, N-770 (phenol novolac type epoxy resin, epoxy equivalent: 183 g / eq) manufactured by DIC Corporation as an epoxy resin, (A-1), (A-2), (A-3), (A-4), 2-ethyl-4-methylimidazole (2E4MZ) was blended as a curing accelerator, and finally the nonvolatile content (N.V.) of each composition was 58% by mass. It adjusted by mix | blending methyl ethyl ketone so that it might become.
Subsequently, it was hardened on the following conditions, the laminated board was made as an experiment, and the heat resistance and the flame retardance were evaluated by the following method. The results are shown in Table 1.

<Laminate production conditions>
Base material: Glass cloth “# 2116” (210 × 280 mm) manufactured by Nitto Boseki Co., Ltd.
Number of plies: 6 Condition of prepreg: 160 ° C
Curing conditions: 200 ° C., 40 kg / cm ² for 1.5 hours, post-molding plate thickness: 0.8 mm

<Heat resistance (glass transition temperature)>
Using a viscoelasticity measuring device (DMA: solid viscoelasticity measuring device RSAII manufactured by Rheometric, rectangular tension method; frequency 1 Hz, heating rate 3 ° C./min), the elastic modulus change is maximized (tan δ change rate is the highest). The (large) temperature was evaluated as the glass transition temperature.

<Linear expansion coefficient>
The laminate was cut into a size of 5 mm × 5 mm × 0.8 mm, and a thermomechanical analysis was performed in a compression mode using a thermomechanical analyzer (TMA: SS-6100 manufactured by Seiko Instruments Inc.) as a test piece. .
Measurement conditions Measurement weight: 88.8mN
Temperature increase rate: 2 times at 3 ° C / minute Measurement temperature range: -50 ° C to 300 ° C
The measurement under the above conditions was performed twice for the same sample, and the average expansion coefficient in the temperature range from 240 ° C. to 280 ° C. in the second measurement was evaluated as the linear expansion coefficient.

表１中の略号は以下の通りである。
Ａ−１：前記フェノール樹脂Ａ−１
Ａ−２：前記フェノール樹脂Ａ−２
Ａ−３：前記フェノール樹脂Ａ−３
Ａ−４：前記フェノール樹脂Ａ−４
Ｎ−７７０：フェノールノボラック型エポキシ樹脂（エポキシ当量：１８３ｇ／ｅｑ．）
２Ｅ４ＭＺ：２−エチル−４−メチルイミダゾール

Abbreviations in Table 1 are as follows.
A-1: The phenol resin A-1
A-2: The phenol resin A-2
A-3: The phenol resin A-3
A-4: The phenol resin A-4
N-770: phenol novolac type epoxy resin (epoxy equivalent: 183 g / eq.)
2E4MZ: 2-ethyl-4-methylimidazole

Claims (6)

A curable resin composition comprising an epoxy resin (A) and a phenol resin (B) as essential components, wherein the phenol resin (B) comprises naphthol (N), phenols (P), and formaldehyde (F). The molar ratio [naphthol (N) / phenols (P)] is a ratio of 11/1 to 100/1, and the molar ratio [formaldehyde (F) / (naphthol (N) + phenols (P )] Is obtained by polycondensation reaction at a ratio of 0.6 to 0.8. The curable resin composition according to claim 1, wherein the phenol resin (B) has a softening point in the range of 110 to 150 ° C. The curable resin composition according to claim 1, wherein the phenol resin (B) is obtained by reacting naphthol (N), phenols (P) and formaldehyde (F) under an acid catalyst. The curable resin composition according to claim 1, wherein the epoxy resin (A) is a novolac type epoxy resin. Hardened | cured material formed by carrying out hardening reaction of the curable resin composition as described in any one of Claims 1-4. A resin composition obtained by further blending the curable resin composition according to any one of claims 1 to 4 with an organic solvent (C) to form a varnish, impregnating the reinforcing base material, and heating the copper foil. Printed wiring board obtained by crimping.